Also flagged:mitochondriaAPOEbrain injurymitochondrialresponse to globalrespiratory chain
Journal Article2011-08-31✓ 2 SnippetsJames R, Searcy JL, Le Bihan T, Martin SF, Gliddon CM, Povey J, Deighton RF, Kerr LE, McCulloch J, Horsburgh K.
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Results)
…The APOE genotype network (IPA score=23), generated from 14 proteins, was attributed the functions of ‘cellular compromise, genetic disorder, and neurologic disease.' The APOE genotype network included ETFA as a major hub protein as well as inner membrane components of complex 1 (NDUFB5 and NDUFB10), but required the insertion of multiple MT-ND family members as well as the hub proteins SNCA and HTT to allow for cohesion.…
Results)
…proteins SNCA andHTTto allow for…
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Apolipoprotein E (APOE)-ɛ4 is associated with a deleterious outcome after ischemic brain injury, which may involve abnormal regulation of mitochondrial function. We have assessed the mitochondrial proteomic response of APOE-ɛ3 and APOE-ɛ4 transgenic mice to transient global ischemic injury in the hippocampus. A genotype-dependent increase in ApoE levels in mitochondria was observed after ischemia, with APOE-ɛ4 mice showing significantly greater increases than APOE-ɛ3 mice. Quantitative analysis of the mitochondria-enriched fractions was performed using liquid-chromatography mass spectrometry coupled to label-free analysis. Of the 1,067 identified proteins, 274 were mitochondria associated. Mitochondrial protein expression was significantly different between genotypes under basal conditions as well as in response to global ischemia. A total of 12 mitochondrial proteins (including respiratory chain proteins NDUFA11, NDUFS3, NDUF5B, ATP5J, as well as ETFA, CYB5B, ATP6V1A, HSPA1B, OXR1, GLUL, IARS2, and PHYHIPL) were significantly altered with respect to genotype, global ischemia, or their interaction (P<0.01). A compelling interactome, created using proteins found to be significantly modulated by global ischemia (P<0.05), involved proteins that regulate energy production and oxidative stress. Thus, APOE genotype has a differential effect on the mitochondrial protein expression in the absence and presence of an injury, which may underlie the differing genotype susceptibility.
Also flagged:localizationsynapsesribonucleoproteinnucleussynapsememories
Journal Article2011-08-31No SnippetsDoyle M, Kiebler MA.
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The localization of RNAs critically contributes to many important cellular processes in an organism, such as the establishment of polarity, asymmetric division and migration during development. Moreover, in the central nervous system, the local translation of mRNAs is thought to induce plastic changes that occur at synapses triggered by learning and memory. Here, we will critically review the physiological functions of well-established dendritically localized mRNAs and their associated factors, which together form ribonucleoprotein particles (RNPs). Second, we will discuss the life of a localized transcript from transcription in the nucleus to translation at the synapse and introduce the concept of the 'RNA signature' that is characteristic for each transcript. Finally, we present the 'sushi belt model' of how localized RNAs within neuronal RNPs may dynamically patrol multiple synapses rather than being anchored at a single synapse. This new model integrates our current understanding of synaptic function ranging from synaptic tagging and capture to functional and structural reorganization of the synapse upon learning and memory.
Journal Article2011-08-31✓ 5 SnippetsWang X, Ono Y, Tan SC, Chai RJ, Parkin C, Ingham PW.
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Abstract)
…Here we identify sox6 cis-regulatory sequences that drive fast-twitch-specific expression in a Prdm1a-dependent manner.…
Abstract)
…We find that translational repression of sox6 is mediated by miR-499, the slow-twitch-specific expression of which is in turn controlled by Prdm1a, forming a regulatory loop that initiates and maintains the slow-twitch muscle lineage.…
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…sequentially to restrictSox6activity to the…
Abstract)
…Sox6has been proposed…
Abstract)
…In zebrafish,sox6transcription is repressed…
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Sox6 has been proposed to play a conserved role in vertebrate skeletal muscle fibre type specification. In zebrafish, sox6 transcription is repressed in slow-twitch progenitors by the Prdm1a transcription factor. Here we identify sox6 cis-regulatory sequences that drive fast-twitch-specific expression in a Prdm1a-dependent manner. We show that sox6 transcription subsequently becomes derepressed in slow-twitch fibres, whereas Sox6 protein remains restricted to fast-twitch fibres. We find that translational repression of sox6 is mediated by miR-499, the slow-twitch-specific expression of which is in turn controlled by Prdm1a, forming a regulatory loop that initiates and maintains the slow-twitch muscle lineage.
…Loss-of-function unc-5 mutants displayed increased protrusion in repelled growth cones, whereas loss-of-function unc-6 or unc-40 mutants caused decreased protrusion.…
Title)
…receptors UNC-5 and UNC-40/DCCmodulate growth cone…
Abstract)
…diating attraction via UNC-40/DCCfamily receptors and…
Abstract)
…NC-6/netrin, UNC-5 and UNC-40/DCCmodulated the extent…
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…DCC…
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The UNC-6/netrin guidance cue functions in axon guidance in vertebrates and invertebrates, mediating attraction via UNC-40/DCC family receptors and repulsion via by UNC-5 family receptors. The growth cone reads guidance cues and extends lamellipodia and filopodia, actin-based structures that sense the extracellular environment and power the forward motion of the growth cone. We show that UNC-6/netrin, UNC-5 and UNC-40/DCC modulated the extent of growth cone protrusion that correlated with attraction versus repulsion. Loss-of-function unc-5 mutants displayed increased protrusion in repelled growth cones, whereas loss-of-function unc-6 or unc-40 mutants caused decreased protrusion. In contrast to previous studies, our work suggests that the severe guidance defects in unc-5 mutants may be due to latent UNC-40 attractive signaling that steers the growth cone back towards the ventral source of UNC-6. UNC-6/Netrin signaling also controlled polarity of growth cone protrusion and F-actin accumulation that correlated with attraction versus repulsion. However, filopodial dynamics were affected independently of polarity of protrusion, indicating that the extent versus polarity of protrusion are at least in part separate mechanisms. In summary, we show here that growth cone guidance in response to UNC-6/netrin involves a combination of polarized growth cone protrusion as well as a balance between stimulation and inhibition of growth cone (e.g. filopodial) protrusion.
Also flagged:IronFGF23ADHRfibroblast growth factor 23hypophosphatemiaD
Journal Article2011-08-31✓ 1 SnippetImel EA, Peacock M, Gray AK, Padgett LR, Hui SL, Econs MJ.
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…hemochromatosis…
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<h4>Context</h4>In autosomal dominant hypophosphatemic rickets (ADHR), fibroblast growth factor 23 (FGF23) resists cleavage, causing increased plasma FGF23 levels. The clinical phenotype includes variable onset during childhood or adulthood and waxing/waning of hypophosphatemia. Delayed onset after puberty in females suggests iron status may be important.<h4>Objective</h4>Studies were performed to test the hypothesis that plasma C-terminal and intact FGF23 concentrations are related to serum iron concentrations in ADHR.<h4>Design and setting</h4>Cross-sectional and longitudinal studies of ADHR and a cross-sectional study in healthy subjects were conducted at an academic medical center.<h4>Participants</h4>Participants included 37 subjects with ADHR mutations from four kindreds and 158 healthy adult controls.<h4>Main outcome measure</h4>The relationships of serum iron concentrations with plasma C-terminal and intact FGF23 concentrations were evaluated.<h4>Results</h4>Serum phosphate and 1,25-dihydroxyvitamin D correlated negatively with C-terminal FGF23 and intact FGF23 in ADHR but not in controls. Serum iron was negatively correlated to both C-terminal FGF23 (r = -0.386; P < 0.05) and intact FGF23 (r = -0.602; P < 0.0001) in ADHR. However, control subjects also demonstrated a negative relationship of serum iron with C-terminal FGF23 (r = -0.276; P < 0.001) but no relationship with intact FGF23. Longitudinally in ADHR subjects, C-terminal FGF23 and intact FGF23 concentrations changed negatively with iron concentrations (P < 0.001 and P = 0.055, respectively), serum phosphate changed negatively with C-terminal FGF23 and intact FGF23 (P < 0.001), and there was a positive relationship between serum iron and phosphate (P < 0.001).<h4>Conclusions</h4>Low serum iron is associated with elevated FGF23 in ADHR. However, in controls, low serum iron was also associated with elevated C-terminal FGF23, but not intact FGF23, suggesting cleavage maintains homeostasis despite increased FGF23 expression.
Discovering chemosensitivity pathways or nodes is an attractive strategy for formulating new drug combinations for cancer. Microtubules are among the most successful anticancer drug targets. Therefore, we implemented a small interfering RNA (siRNA) synthetic lethal screen targeting 5520 unique druggable genes to identify novel chemosensitivity nodes for vinblastine, a microtubule-destabilizing agent used clinically. We transiently transfected human glioblastoma cells with siRNAs for 48 h and then treated cells with a sublethal concentration of vinblastine. Forty-eight hours later, we analyzed cell viability and, using a series of statistical methods, identified 65 gene products that, when suppressed, sensitized glioblastoma cells to vinblastine. After completion of the secondary assays, we focused on one siRNA, B-cell lymphoma extra large (BCL-xL), because of its role in the intrinsic apoptosis signaling pathway as well as the availability of pharmacological inhibitors. We found that nontoxic concentrations of 4-[4-[[2-(4-chlorophenyl)-5,5-dimethylcyclohexen-1-yl]methyl]piperazin-1-yl]-N-[4-[[(2R)-4-morpholin-4-yl-1-phenylsulfanylbutan-2-yl]amino]-3-(trifluoromethylsulfonyl)phenyl]sulfonylbenzamide (ABT-263), an inhibitor of the BCL-2 family members (BCL-2, BCL-xL, and BCL-w), sensitized glioblastoma and non-small-cell lung cancer cells to vinblastine and induced apoptosis through the intrinsic cell death pathway. These results illustrate the usefulness of unbiased siRNA screens as a method for identifying potential novel anticancer therapeutic combinations.
Also flagged:breast tumorstriple negative breast cancertumorcell proliferationdeathCaspase 3
Journal Article2011-08-31No SnippetsAdams LS, Kanaya N, Phung S, Liu Z, Chen S.
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Previous studies in our laboratory demonstrated that blueberry (BB) extract exhibited antitumor activity against MDA-MB-231 triple negative breast cancer (TNBC) cells and decreased metastatic potential in vitro. The current study tested 2 doses of whole BB powder, 5 and 10% (wt:wt) in the diet, against MDA-MB-231 tumor growth in female nude mice. In this study, tumor volume was 75% lower in mice fed the 5% BB diet and 60% lower in mice fed the 10% BB diet than in control mice (P ≤ 0.05). Tumor cell proliferation (Ki-67) was lower in the 5 and 10% BB-fed mice and cell death (Caspase 3) was greater in the 10% BB-fed mice compared to control mice (P ≤ 0.05). Gene analysis of tumor tissues from the 5% BB-fed mice revealed significantly altered expression of genes important to inflammation, cancer, and metastasis, specifically, Wnt signaling, thrombospondin-2, IL-13, and IFNγ. To confirm effects on Wnt signaling, analysis of tumor tissues from 5% BB-fed mice revealed lower β-catenin expression and glycogen synthase kinase-3β phosphorylation with greater expression of the β-catenin inhibitory protein adenomatous polyposis coli compared to controls. A second study tested the ability of the 5% BB diet to inhibit MDA-MB-231-luc-D3H2LN metastasis in vivo. In this study, 5% BB-fed mice developed 70% fewer liver metastases (P = 0.04) and 25% fewer lymph node metastases (P = 0.09) compared to control mice. This study demonstrates the oral antitumor and metastasis activity of whole BB powder against TNBC in mice.
Also flagged:FKBP51FKBP52FK1prolinecancersprotein aggregation disorders
Journal Article2011-08-31No SnippetsStorer CL, Dickey CA, Galigniana MD, Rein T, Cox MB.
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FKBP51 and FKBP52 are diverse regulators of steroid hormone receptor signaling, including receptor maturation, hormone binding and nuclear translocation. Although structurally similar, they are functionally divergent, which is largely attributed to differences in the FK1 domain and the proline-rich loop. FKBP51 and FKBP52 have emerged as likely contributors to a variety of hormone-dependent diseases, including stress-related diseases, immune function, reproductive functions and a variety of cancers. In addition, recent studies have implicated FKBP51 and FKBP52 in Alzheimer's disease and other protein aggregation disorders. This review summarizes our current understanding of FKBP51 and FKBP52 interactions within the receptor-chaperone complex, their contributions to health and disease, and their potential as therapeutic targets for the treatment of these diseases.
Fluorescent proteins and dyes are essential tools for the study of protein trafficking, localization and function in cells. While fluorescent proteins such as green fluorescence protein (GFP) have been extensively used as fusion partners to proteins to track the properties of a protein of interest, recent developments with smaller tags enable new functionalities of proteins to be examined in cells such as conformational change and protein-association. One small tag system involves a tetracysteine motif (CCXXCC) genetically inserted into a target protein, which binds to biarsenical dyes, ReAsH (red fluorescent) and FlAsH (green fluorescent), with high specificity even in live cells. The TC/biarsenical dye system offers far less steric constraints to the host protein than fluorescent proteins which has enabled several new approaches to measure conformational change and protein-protein interactions. We recently developed a novel application of TC tags as sensors of oligomerization in cells expressing mutant huntingtin, which when mutated aggregates in neurons in Huntington disease. Huntingtin was tagged with two fluorescent dyes, one a fluorescent protein to track protein location, and the second a TC tag which only binds biarsenical dyes in monomers. Hence, changes in colocalization between protein and biarsenical dye reactivity enabled submicroscopic oligomer content to be spatially mapped within cells. Here, we describe how to label TC-tagged proteins fused to a fluorescent protein (Cherry, GFP or CFP) with FlAsH or ReAsH in live mammalian cells and how to quantify the two color fluorescence (Cherry/FlAsH, CFP/FlAsH or GFP/ReAsH combinations).
Also flagged:Huntington's DiseaseHuntingtinneurodegenerative diseasetranslationalmTORInsulin
Journal Article2011-08-31✓ 5 SnippetsSchulte J, Sepp KJ, Wu C, Hong P, Littleton JT.
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Abstract)
…Huntingtin neurotoxicity suppressors identified through our screen also restored viability in an in vivo Drosophila Huntington's Disease model, making them attractive candidates for further therapeutic evaluation.…
Abstract)
…Drosophila primary neurons offer a sensitive readout for neurotoxicty, as their neurites develop dysmorphic features in the presence of mutant polyglutamine-expanded Huntingtin compared to nonpathogenic Huntingtin.…
Results)
…To screen for suppressors of HD toxicity we therefore monitored the presence of Htt aggregates, as well as morphology, to evaluate overall neuron health.…
Discussion)
…Cultures expressing a 588 amino acid fragment of human Htt containing an expanded polyQ domain (138Q) display robust cytoplasmic Htt aggregates, and have dystrophic neurites compared to Htt15Q control cultures.…
Results)
…From the visual-based screens, three novel suppressors of Htt polyQ toxicity were identified: 1 RNAi hit (lkb1), and 2 compounds (Camptothecin and 10-Hydroxycamptothecin).…
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To identify Huntington's Disease therapeutics, we conducted high-content small molecule and RNAi suppressor screens using a Drosophila primary neural culture Huntingtin model. Drosophila primary neurons offer a sensitive readout for neurotoxicty, as their neurites develop dysmorphic features in the presence of mutant polyglutamine-expanded Huntingtin compared to nonpathogenic Huntingtin. By tracking the subcellular distribution of mRFP-tagged pathogenic Huntingtin and assaying neurite branch morphology via live-imaging, we identified suppressors that could reduce Huntingtin aggregation and/or prevent the formation of dystrophic neurites. The custom algorithms we used to quantify neurite morphologies in complex cultures provide a useful tool for future high-content screening approaches focused on neurodegenerative disease models. Compounds previously found to be effective aggregation inhibitors in mammalian systems were also effective in Drosophila primary cultures, suggesting translational capacity between these models. However, we did not observe a direct correlation between the ability of a compound or gene knockdown to suppress aggregate formation and its ability to rescue dysmorphic neurites. Only a subset of aggregation inhibitors could revert dysmorphic cellular profiles. We identified lkb1, an upstream kinase in the mTOR/Insulin pathway, and four novel drugs, Camptothecin, OH-Camptothecin, 18β-Glycyrrhetinic acid, and Carbenoxolone, that were strong suppressors of mutant Huntingtin-induced neurotoxicity. Huntingtin neurotoxicity suppressors identified through our screen also restored viability in an in vivo Drosophila Huntington's Disease model, making them attractive candidates for further therapeutic evaluation.
Also flagged:gene expressioncaffeineCYP1A1CYP1A2polycyclic aromatic hydrocarbonsmetabolism
Journal Article2011-08-30✓ 2 SnippetsAmin N, Byrne E, Johnson J, Chenevix-Trench G, Walter S, Nolte IM, kConFab Investigators, Vink JM, Rawal R, Mangino M, Teumer A, Keers JC, Verwoert G, Baumeister S, Biffar R, Petersmann A, Dahmen N, Doering A, Isaacs A, Broer L, Wray NR, Montgomery GW, Levy D, Psaty BM, Gudnason V, Chakravarti A, Sulem P, Gudbjartsson DF, Kiemeney LA, Thorsteinsdottir U, Stefansson K, van Rooij FJ, Aulchenko YS, Hottenga JJ, Rivadeneira FR, Hofman A, Uitterlinden AG, Hammond CJ, Shin SY, Ikram A, Witteman JC, Janssens AC, Snieder H, Tiemeier H, Wolfenbuttel BH, Oostra BA, Heath AC, Wichmann E, Spector TD, Grabe HJ, Boomsma DI, Martin NG, van Duijn CM.
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Results)
…, NRG2 andHFE.…
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…Of these genes,HFEis most well…
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Coffee consumption is a model for addictive behavior. We performed a meta-analysis of genome-wide association studies (GWASs) on coffee intake from 8 Caucasian cohorts (N=18 176) and sought replication of our top findings in a further 7929 individuals. We also performed a gene expression analysis treating different cell lines with caffeine. Genome-wide significant association was observed for two single-nucleotide polymorphisms (SNPs) in the 15q24 region. The two SNPs rs2470893 and rs2472297 (P-values=1.6 × 10(-11) and 2.7 × 10(-11)), which were also in strong linkage disequilibrium (r(2)=0.7) with each other, lie in the 23-kb long commonly shared 5' flanking region between CYP1A1 and CYP1A2 genes. CYP1A1 was found to be downregulated in lymphoblastoid cell lines treated with caffeine. CYP1A1 is known to metabolize polycyclic aromatic hydrocarbons, which are important constituents of coffee, whereas CYP1A2 is involved in the primary metabolism of caffeine. Significant evidence of association was also detected at rs382140 (P-value=3.9 × 10(-09)) near NRCAM-a gene implicated in vulnerability to addiction, and at another independent hit rs6495122 (P-value=7.1 × 10(-09))-an SNP associated with blood pressure-in the 15q24 region near the gene ULK3, in the meta-analysis of discovery and replication cohorts. Our results from GWASs and expression analysis also strongly implicate CAB39L in coffee drinking. Pathway analysis of differentially expressed genes revealed significantly enriched ubiquitin proteasome (P-value=2.2 × 10(-05)) and Parkinson's disease pathways (P-value=3.6 × 10(-05)).
Also flagged:Cytochrome P4501A2Cyp1a2uroporphyriaporphyria cutanea tardaporphyriairon
Journal Article2011-08-30✓ 5 SnippetsPhillips JD, Kushner JP, Bergonia HA, Franklin MR.
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Abstract)
…Here we report uroporphyria development in Cyp1a2-/- mice additionally null for both alleles of the hemochromatosis (Hfe) gene and heterozygous for deletion of the uroporphyrinogen decarboxylase (Urod) gene (genotype: Cyp1a2-/-;Hfe-/-;Urod+/-), demonstrating that upon adding porphyria-predisposing genetic manipulations, Cyp1a2 is not essential.…
Abstract)
…alleles of thehemochromatosis( Hfe )…
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…the hemochromatosis (Hfe) gene and…
Abstract)
…Cyp1a2 −/− ;Hfe−/− ;Urod +/−),…
Abstract)
…Cyp1a2 −/− ;Hfe−/− ;Urod +/−…
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Cytochrome P4501A2 (Cyp1a2) is important in the development of uroporphyria in mice, a model of porphyria cutanea tarda in humans. Heretofore, mice homozygous for the Cyp1a2-/- mutation do not develop uroporphyria with treatment regimens that result in uroporphyria in wild-type mice. Here we report uroporphyria development in Cyp1a2-/- mice additionally null for both alleles of the hemochromatosis (Hfe) gene and heterozygous for deletion of the uroporphyrinogen decarboxylase (Urod) gene (genotype: Cyp1a2-/-;Hfe-/-;Urod+/-), demonstrating that upon adding porphyria-predisposing genetic manipulations, Cyp1a2 is not essential. Cyp1a2-/-;Hfe-/-;Urod+/- mice were treated with various combinations of an iron-enriched diet, parenteral iron-dextran, drinking water containing δ-aminolevulinic acid and intraperitoneal Aroclor 1254 (a polychlorinated biphenyl mixture) and analyzed for uroporphyrin accumulation. Animals fed an iron-enriched diet alone did not develop uroporphyria but uroporphyria developed with all treatments that included iron supplementation and δ-aminolevulinic acid, even with a regimen without Aroclor 1254. Hepatic porphyrin levels correlated with low UROD activity and high levels of an inhibitor of UROD but marked variability in the magnitude of the porphyric response was present in all treatment groups. Gene expression profiling revealed no major differences between genetically identical triple cross mice exhibiting high and low magnitude porphyric responses from iron-enriched diet and iron-dextran supplementation, and δ-aminolevulinic acid. Even though the variation in porphyric response did not parallel the hepatic iron concentration, the results are compatible with the presence of a Cyp1a2-independent, iron-dependent pathway for the generation of uroporphomethene, the UROD inhibitor required for the expression of uroporphyria in mice and PCT in humans.
Also flagged:systemic lupus erythematosusautoimmune diseasesautoimmune disordersgene-expressionmethylationhistone
Journal Article2011-08-30✓ 1 SnippetHedrich CM, Tsokos GC.
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…TNFSF4…
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The pathogenic origin of autoimmune diseases can be traced to both genetic susceptibility and epigenetic modifications arising from exposure to the environment. Epigenetic modifications influence gene expression and alter cellular functions without modifying the genomic sequence. CpG-DNA methylation, histone tail modifications and microRNAs (miRNAs) are the main epigenetic mechanisms of gene regulation. Understanding the molecular mechanisms that are involved in the pathophysiology of autoimmune diseases is essential for the introduction of effective, target-directed and tolerated therapies. In this review, we summarize recent findings that signify the importance of epigenetic modifications in autoimmune disorders while focusing on systemic lupus erythematosus. We also discuss future directions in basic research, autoimmune diagnostics and applied therapy.
Journal Article2011-08-30No SnippetsRossetti G, Cossio P, Laio A, Carloni P.
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The first 17 amino acids of Huntingtin protein (N17) play a crucial role in the protein's aggregation. Here we predict its free energy landscape in aqueous solution by using bias exchange metadynamics. All our findings are consistent with experimental data. N17 populates four main kinetic basins, which interconvert on the microsecond time-scale. The most populated basin (about 75%) is a random coil, with an extended flat exposed hydrophobic surface. This might create a hydrophobic seed promoting Huntingtin aggregation. The other main populated basins contain helical conformations, which could facilitate N17 binding on its cellular targets.
Also flagged:resveratrolagingmetabolic disorderscancerAMPKSIRT1
Journal Article2011-08-30✓ 1 SnippetPasinetti GM, Wang J, Marambaud P, Ferruzzi M, Gregor P, Knable LA, Ho L.
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Resveratrol is a naturally occurring polyphenolic compound associated with beneficial effects on aging, metabolic disorders, inflammation and cancer in animal models and resveratrol is currently being tested in numerous clinical trials. Resveratrol may exert these effects by targeting several key metabolic sensor/effector proteins, such as AMPK, SIRT1, and PGC-1α. Resveratrol has also received considerable attention recently for its potential neuroprotective effects in neurodegenerative disorders where AMPK, SIRT1 or PGC-1α may represent promising therapeutic targets. A recent study published in Experimental Neurology (Ho et al., 2010) examined the therapeutic potential of a micronised proprietary resveratrol formulation, SRT501 in the N171-82Q transgenic mouse model of Huntington's disease (HD). HD is a progressive and devastating genetic neurodegenerative disorder that is associated with downregulation of PGC-1α activity. The Ho et al. study found that SRT501 treatment did not lead to significant improvement in weight loss, motor performance, survival and striatal atrophy. However, other studies have reported neuroprotective effects of resveratrol and a distantly related polyphenol, fisetin, in HD models. HD has been associated with diabetes mellitus. Interestingly, evidence from the Ho et al. study suggests a resveratrol formulation induced beneficial anti-diabetic effect in N171-82Q mice. This commentary summarizes the pertinent outcomes from the Ho et al. study and discusses the further prospects of resveratrol and other polyphenols, including novel grape-derived polyphenols, in the treatment of HD and other neurodegenerative disorders.
Also flagged:IronapotransferrinascorbateTroloxtransferrin receptor-1death
Journal Article2011-08-30✓ 1 SnippetChen-Roetling J, Liu W, Regan RF.
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…hemochromatosis…
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Nonheme iron accumulates in CNS tissue after ischemic and hemorrhagic insults and may contribute to cell loss. The source of this iron has not been precisely defined. After blood-brain barrier disruption, CNS cells may be exposed to plasma concentrations of transferrin-bound iron (TBI), which exceed that in the CSF by over 50-fold. In this study, the hypothesis that these concentrations of TBI produce cell iron accumulation and neurotoxicity was tested in primary cortical cultures. Treatment with 0.5-3mg/ml holotransferrin for 24h resulted in the loss of 20-40% of neurons, associated with increases in malondialdehyde, ferritin, heme oxygenase-1, and iron; transferrin receptor-1 expression was reduced by about 50%. Deferoxamine, 2,2'-bipyridyl, Trolox, and ascorbate prevented all injury, but apotransferrin was ineffective. Cell TBI accumulation was significantly reduced by deferoxamine, 2,2'-bipyridyl, and apotransferrin, but not by ascorbate or Trolox. After treatment with (55)Fe-transferrin, approximately 40% of cell iron was exported within 16h. Net export was increased by deferoxamine and 2,2'-bipyridyl, but not by apotransferrin. These results suggest that downregulation of transferrin receptor-1 expression is insufficient to prevent iron-mediated death when neurons are exposed to plasma concentrations of TBI. Chelator therapy may be beneficial for acute CNS injuries associated with loss of blood-brain barrier integrity.
Also flagged:serotonin transporterpositron5SerotoninSLC6A4anxiety
Journal Article2011-08-30✓ 5 SnippetsKobiella A, Reimold M, Ulshöfer DE, Ikonomidou VN, Vollmert C, Vollstädt-Klein S, Rietschel M, Reischl G, Heinz A, Smolka MN.
In-Text Gene Mentions
Introduction)
…Serotonin (5-HT) neurotransmission has a key role in stress sensitivity and in vulnerability to negative affect.1, 2 The serotonin transporter gene (SLC6A4) encodes the serotonin transporter protein (5-HTT), which acts as a key regulator by removing serotonin from the synaptic cleft.…
Discussion)
…This neurodevelopmental view is supported by studies with 5-HTT knockout mice and rats and with mice and rats prenatally exposed to selective serotonin reuptake inhibitors (SSRI), who both exhibit increased extracellular serotonin levels.51 Those studies show that 5-HTT blockade during early development caused alterations in the morphology of pyramidal neurons in the amygdala32 and increased anxiety and depression which persisted into adulthood (opposing the effects induced by adult SSRI intake).52, 53 It is argued that those behavioral and morphological effects are similar to the effects of the S-allele of the 5-HTTLPR polymorphism.…
Abstract)
…urrent serotonin transporter (5-HTT) levels or rather…
Introduction)
…erotonin transporter protein (5-HTT), which acts as…
Introduction)
…activity and regulates5-HTTexpression and density…
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The serotonin transporter-linked promoter region (5-HTTLPR) polymorphism of the serotonin transporter gene is associated with amygdala response during negative emotion. The aim of this study was to investigate whether this genotype effect on amygdala function is mediated by current serotonin transporter (5-HTT) levels or rather by genetically induced influences during neurodevelopment, shaping brain structure. A total of 54 healthy subjects underwent functional and structural magnetic resonance imaging, [(11)C]DASB positron emission tomography and 5-HTTLPR genotyping to analyze the interrelationships between amygdala activation during processing of unpleasant stimuli, 5-HTTLPR genotype, amygdala volumes and 5-HTT levels in the midbrain and in other brain regions. In line with previous research, carriers of the short allele (S) showed increased amygdala activation. Path analysis demonstrated that this genotype effect was not procured by current 5-HTT availability but by amygdala structure, with smaller amygdala volumes in the S than in the LL genotype, as well as smaller volumes being associated with increased amygdala activation. Our findings stress the role of genetic effects during neurodevelopment.
Also flagged:obesitycardiovascular diseasesclusterincomplement C3complement C3bpigment epithelium-derived factor
Journal Article2011-08-29✓ 2 SnippetsOberbach A, Blüher M, Wirth H, Till H, Kovacs P, Kullnick Y, Schlichting N, Tomm JM, Rolle-Kampczyk U, Murugaiyan J, Binder H, Dietrich A, von Bergen M.
Obesity is associated with multiple adverse health effects and a high risk of developing metabolic and cardiovascular diseases. Therefore, there is a great need to identify circulating parameters that link changes in body fat mass with obesity. This study combines proteomic and metabolomic approaches to identify circulating molecules that discriminate healthy lean from healthy obese individuals in an exploratory study design. To correct for variations in physical activity, study participants performed a one hour exercise bout to exhaustion. Subsequently, circulating factors differing between lean and obese individuals, independent of physical activity, were identified. The DIGE approach yielded 126 differentially abundant spots representing 39 unique proteins. Differential abundance of proteins was confirmed by ELISA for antithrombin-III, clusterin, complement C3 and complement C3b, pigment epithelium-derived factor (PEDF), retinol binding protein 4 (RBP4), serum amyloid P (SAP), and vitamin-D binding protein (VDBP). Targeted serum metabolomics of 163 metabolites identified 12 metabolites significantly related to obesity. Among those, glycine (GLY), glutamine (GLN), and glycero-phosphatidylcholine 42:0 (PCaa 42:0) serum concentrations were higher, whereas PCaa 32:0, PCaa 32:1, and PCaa 40:5 were decreased in obese compared to lean individuals. The integrated bioinformatic evaluation of proteome and metabolome data yielded an improved group separation score of 2.65 in contrast to 2.02 and 2.16 for the single-type use of proteomic or metabolomics data, respectively. The identified circulating parameters were further investigated in an extended set of 30 volunteers and in the context of two intervention studies. Those included 14 obese patients who had undergone sleeve gastrectomy and 12 patients on a hypocaloric diet. For determining the long-term adaptation process the samples were taken six months after the treatment. In multivariate regression analyses, SAP, CLU, RBP4, PEDF, GLN, and C18:2 showed the strongest correlation to changes in body fat mass. The combined serum proteomic and metabolomic profiling reveals a link between the complement system and obesity and identifies both novel (C3b, CLU, VDBP, and all metabolites) and confirms previously discovered markers (PEDF, RBP4, C3, ATIII, and SAP) of body fat mass changes.
Also flagged:synthesistriptycenecarboxylateBMM) hydroxylaseirontriflate
Journal Article2011-08-29No SnippetsLi Y, Cao R, Lippard SJ.
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A novel triptycene-based ligand with a preorganized framework was designed to model carboxylate-bridged diiron active sites in bacterial multicomponent monooxygenase (BMM) hydroxylase enzymes. The synthesis of the bis(benzoxazole)-appended ligand L1 depicted was accomplished in 11 steps. Reaction of L1 with iron(II) triflate and a carboxylate source afforded the desired diiron(II) complex [Fe(2)L1(μ-OH)(μ-O(2)CAr(Tol))(OTf)(2)].
Changes in iron regulation characterize the malignant state. However, the pathways that effect these changes and their specific impact on prognosis remain poorly understood. We capitalized on publicly available microarray datasets comprising 674 breast cancer cases to systematically investigate how expression of genes related to iron metabolism is linked to breast cancer prognosis. Of 61 genes involved in iron regulation, 49% were statistically significantly associated with distant metastasis-free survival. Cases were divided into test and training cohorts, and the supervised principal component method was used to stratify cases into risk groups. Optimal risk stratification was achieved with a model comprising 16 genes, which we term the iron regulatory gene signature (IRGS). Multivariable analysis revealed that the IRGS contributes information not captured by conventional prognostic indicators (HR = 1.61; 95% confidence interval: 1.16-2.24; P = 0.004). The IRGS successfully stratified homogeneously treated patients, including ER+ patients treated with tamoxifen monotherapy, both with (P = 0.006) and without (P = 0.03) lymph node metastases. To test whether multiple pathways were embedded within the IRGS, we evaluated the performance of two gene dyads with known roles in iron biology in ER+ patients treated with tamoxifen monotherapy (n = 371). For both dyads, gene combinations that minimized intracellular iron content [anti-import: TFRC(Low)/HFE(High); or pro-export: SLC40A1 (ferroportin)(High)/HAMP(Low)] were associated with favorable prognosis (P < 0.005). Although the clinical utility of the IRGS will require further evaluation, its ability to both identify high-risk patients within traditionally low-risk groups and low-risk patients within high-risk groups has the potential to affect therapeutic decision making.
Also flagged:Netrin-1laminin-related proteinacute kidney injurycisplatinfatty acid binding proteincytokine
Journal Article2011-08-29✓ 1 SnippetRajasundari A, Pays L, Mehlen P, Ramesh G.
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Netrin-1, a multifunctional laminin-related protein is widely expressed in various tissues, including kidney. The pathophysiological roles of netrin-1 in toxic acute kidney injury are unknown. To determine the role of netrin-1 in cisplatin-induced nephrotoxicity, we used netrin-1 transgenic mice that overexpress netrin-1 in the proximal tubular epithelium using the fatty acid binding protein promoter. Administration of cisplatin caused severe renal injury in WT mice but not in netrin-1 transgenic mice. Functional improvement was associated with better preservation of morphology, reduced cytokine expression and oxidative stress in the kidney, and reduced serum and urine cytokine and chemokine levels of transgenic mice as compared with WT mice. Cisplatin induced an increase in neutrophil infiltration into the kidney of WT mice, which was not significantly reduced in netrin-1 transgenic mice. Interestingly, ischemia reperfusion induced a large increase in apoptosis in WT mice but not in netrin-1 transgenic mice (215 ± 40 vs 94 ± 20 cells/5 HPF ( × 400), P < 0.0001), which was associated with reduced caspase-3 and p53 activation in the transgenic kidney. These results suggest that netrin-1 protects renal tubular epithelial cells against cisplatin-induced kidney injury by suppressing apoptosis and inflammation.
…To understand how the HTT CAG repeat length changes over time, we quantified somatic instability of the CAG repeat in Huntington's disease CAG knock-in mice from 2-16 months of age in liver, striatum, spleen and tail.…
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<h4>Background</h4>Age at onset of Huntington's disease (HD) is largely determined by the CAG trinucleotide repeat length in the HTT gene. Importantly, the CAG repeat undergoes tissue-specific somatic instability, prevalent in brain regions that are disease targets, suggesting a potential role for somatic CAG repeat instability in modifying HD pathogenesis. Thus, understanding underlying mechanisms of somatic CAG repeat instability may lead to discoveries of novel therapeutics for HD. Investigation of the dynamics of the CAG repeat size changes over time may provide insights into the mechanisms underlying CAG repeat instability.<h4>Methodology/principal findings</h4>To understand how the HTT CAG repeat length changes over time, we quantified somatic instability of the CAG repeat in Huntington's disease CAG knock-in mice from 2-16 months of age in liver, striatum, spleen and tail. The HTT CAG repeat in spleen and tail was very stable, but that in liver and striatum expanded over time at an average rate of one CAG per month. Interestingly, the patterns of repeat instability were different between liver and striatum. Unstable CAG repeats in liver repeatedly gained similar sizes of additional CAG repeats (approximately two CAGs per month), maintaining a distinct population of unstable repeats. In contrast, unstable CAG repeats in striatum gained additional repeats with different sizes resulting in broadly distributed unstable CAG repeats. Expanded CAG repeats in the liver were highly enriched in polyploid hepatocytes, suggesting that the pattern of liver instability may reflect the restriction of the unstable repeats to a unique cell type.<h4>Conclusions/significance</h4>Our results are consistent with repeat expansion occurring as a consequence of recurrent small repeat insertions that differ in different tissues. Investigation of the specific mechanisms that underlie liver and striatal instability will contribute to our understanding of the relationship between instability and disease and the means to intervene in this process.
Also flagged:calciumsarcoplasmic reticulumextracellularryanodine receptorafterdepolarizationsRyR2
Journal Article2011-08-29No SnippetsLlach A, Molina CE, Alvarez-Lacalle E, Tort L, Benítez R, Hove-Madsen L.
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Calcium release from the sarcoplasmic reticulum (SR) plays a central role in the regulation of cardiac contraction and rhythm in mammals and humans but its role is controversial in teleosts. Since the zebrafish is an emerging model for studies of cardiovascular function and regeneration we here sought to determine if basic features of SR calcium release are phylogenetically conserved. Confocal calcium imaging was used to detect spontaneous calcium release (calcium sparks and waves) from the SR. Calcium sparks were detected in 16 of 38 trout atrial myocytes and 6 of 15 ventricular cells. The spark amplitude was 1.45±0.03 times the baseline fluorescence and the time to half maximal decay of sparks was 27±3 ms. Spark frequency was 0.88 sparks µm(-1) min(-1) while calcium waves were 8.5 times less frequent. Inhibition of SR calcium uptake reduced the calcium transient (F/F(0)) from 1.77±0.17 to 1.12±0.18 (p = 0.002) and abolished calcium sparks and waves. Moreover, elevation of extracellular calcium from 2 to 10 mM promoted early and delayed afterdepolarizations (from 0.6±0.3 min(-1) to 8.1±2.0 min(-1), p = 0.001), demonstrating the ability of SR calcium release to induce afterdepolarizations in the trout heart. Calcium sparks of similar width and duration were also observed in zebrafish ventricular myocytes. In conclusion, this is the first study to consistently report calcium sparks in teleosts and demonstrate that the basic features of calcium release through the ryanodine receptor are conserved, suggesting that teleost cardiac myocytes is a relevant model to study the functional impact of abnormal SR function.
Also flagged:ironantibodiestransferrin receptor 1TfR1Tfbinding
Journal Article2011-08-28✓ 1 SnippetRodríguez JA, Luria-Pérez R, López-Valdés HE, Casero D, Daniels TR, Patel S, Avila D, Leuchter R, So S, Ortiz-Sánchez E, Bonavida B, Martínez-Maza O, Charles AC, Pellegrini M, Helguera G, Penichet ML.
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A number of antibodies have been developed that induce lethal iron deprivation (LID) by targeting the transferrin receptor 1 (TfR1/CD71) and either neutralizing transferrin (Tf) binding, blocking internalization of the receptor and/or inducing its degradation. We have developed recombinant antibodies targeting human TfR1 (ch128.1 and ch128.1Av), which induce receptor degradation and are cytotoxic to certain malignant B-cells. We now show that internalization of TfR1 bound to these antibodies can lead to its sequestration and degradation, as well as reduced Tf uptake, and the induction of a transcriptional response consistent with iron deprivation, which is mediated in part by downstream targets of p53. Cells resistant to these antibodies do not sequester and degrade TfR1 after internalization of the antibody/receptor complex, and accordingly maintain their ability to internalize Tf. These findings are expected to facilitate the rational design and clinical use of therapeutic agents targeting iron import via TfR1 in hematopoietic malignancies.
…CCG polymorphisms in the huntingtin gene have no effect on the pathogenesis of patients with Huntington's disease in mainland Chinese families.…
Abstract)
…Huntington's disease (HD) is caused by the abnormal expansion of CAG repeats in the huntingtin gene (HTT).…
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…the huntingtin gene (HTT).…
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Huntington's disease (HD) is caused by the abnormal expansion of CAG repeats in the huntingtin gene (HTT). The adjacent proline-rich region, which also has a CCG polymorphism among people of different races, may also affect the pathogenesis of HD. To study the effect of this polymorphism on patients with HD in mainland China, 53 HD mutant alleles were examined. The results showed that 54.72% of the HD mutant alleles had 10-repeat alleles, and the remaining 45.28% had 7-repeat alleles. Moreover, comparison of the clinical features between the two groups revealed no significant difference. We also investigated its effect on the aggregates in vitro. No significant difference was detected when the morphology and size of the aggregates with the two polymorphisms was compared in cells. Given these findings, it was quite reasonable to suppose that the CCG polymorphism may not influence the pathogenesis of patients with HD in mainland China.
Also flagged:ubiquitin binding proteinTollipHuntington diseaseHDpolyglutamineamino
Journal Article2011-08-27✓ 5 SnippetsOguro A, Kubota H, Shimizu M, Ishiura S, Atomi Y.
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Abstract)
…Here, utilizing a HD cellular model, we report that Tollip, an ubiquitin binding protein that participates in intracellular transport via endosomes, co-localizes with and stimulates aggregation of polyQ-expanded amino-terminal htt.…
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…amino-terminal of hungtintin (htt).…
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…PolyQ-expandedhttforms intracellular ubiquitina…
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… polyQ-expanded amino-terminalhtt.…
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…toxicity of polyQ-expandedhtt.…
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Huntington disease (HD) is caused by the expansion of polyglutamine (polyQ) repeats in the amino-terminal of hungtintin (htt). PolyQ-expanded htt forms intracellular ubiquitinated aggregates in neurons and causes neuronal cell death. Here, utilizing a HD cellular model, we report that Tollip, an ubiquitin binding protein that participates in intracellular transport via endosomes, co-localizes with and stimulates aggregation of polyQ-expanded amino-terminal htt. Furthermore, we demonstrate that Tollip protects cells against the toxicity of polyQ-expanded htt. We propose that association of Tollip with polyubiquitin accelerates aggregation of toxic htt species into inclusions and thus provides a cell protective role by sequestration.
Also flagged:glutamineHDbehavioralglutamateN-methyl-D-aspartate receptorNMDAR
Journal Article2011-08-27✓ 2 SnippetsRaymond LA, André VM, Cepeda C, Gladding CM, Milnerwood AJ, Levine MS.
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Huntington's disease (HD) is a progressive, fatal neurological condition caused by an expansion of CAG (glutamine) repeats in the coding region of the Huntington gene. To date, there is no cure but great strides have been made to understand pathophysiological mechanisms. In particular, genetic animal models of HD have been instrumental in elucidating the progression of behavioral and physiological alterations, which had not been possible using classic neurotoxin models. Our groups have pioneered the use of transgenic HD mice to examine the excitotoxicity hypothesis of striatal neuronal dysfunction and degeneration, as well as alterations in excitation and inhibition in striatum and cerebral cortex. In this review, we focus on synaptic and receptor alterations of striatal medium-sized spiny (MSNs) and cortical pyramidal neurons in genetic HD mouse models. We demonstrate a complex series of alterations that are region-specific and time-dependent. In particular, many changes are bidirectional depending on the degree of disease progression, that is, early vs. late, and also on the region examined. Early synaptic dysfunction is manifested by dysregulated glutamate release in striatum followed by progressive disconnection between cortex and striatum. The differential effects of altered glutamate release on MSNs originating the direct and indirect pathways is also elucidated, with the unexpected finding that cells of the direct striatal pathway are involved early in the course of the disease. In addition, we review evidence for early N-methyl-D-aspartate receptor (NMDAR) dysfunction leading to enhanced sensitivity of extrasynaptic receptors and a critical role of GluN2B subunits. Some of the alterations in late HD could be compensatory mechanisms designed to cope with early synaptic and receptor dysfunctions. The main findings indicate that HD treatments need to be designed according to the stage of disease progression and should consider regional differences.
Although imatinib is firmly established as an effective therapy for newly diagnosed patients with chronic myeloid leukemia (CML), the field continues to advance on several fronts. In this minireview we cover recent results of second generation tyrosine kinase inhibitors in newly diagnosed patients, investigate the state of strategies to discontinue therapy and report on new small molecule inhibitors to tackle resistant disease, focusing on agents that target the T315I mutant of BCR-ABL. As a result of these advances, standard of care in frontline therapy has started to gravitate toward dasatinib and nilotinib, although more observation is needed to fully support this. Stopping therapy altogether remains a matter of clinical trials, and more must be learned about the mechanisms underlying the persistence of leukemic cells with treatment. However, there is good news for patients with the T315I mutation, as effective drugs such as ponatinib are on their way to regulatory approval. Despite these promising data, accelerated or blastic phase disease remains a challenge, possibly due to BCR-ABL-independent resistance.
Also flagged:cancerColon cancergene expressionprimarytumorprimary tumors
Journal Article2011-08-26No SnippetsVidal-Vanaclocha F.
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Colon cancer frequently metastasizes to the liver but the genetic and phenotypic properties of specific cancer cells able to implant and grow in this organ have not yet been established. The contribution of the patient's genetic, physiologic and pathologic backgrounds to the incidence and development of hepatic colon cancer metastases is also presently misunderstood. At a transcriptional level, hepatic metastasis development is in part associated with marked changes in gene expression of colon cancer cells that may originate in the primary tumor. Other changes occur in the liver and are regulated by hepatic cells, which represent the new microenvironment for metastatic colon cancer cells. However, hepatic parenchymal and non-parenchymal cell functions are also affected by both tumor-derived factors and systemic host factors, which suggests that the hepatic metastasis microenvironment is a functional linkage between the hepatic pathophysiology of the colon cancer patient and the biology of its cancer cells. Therefore, together with metastasis-related gene profiles suggesting the existence of liver metastasis potential in primary tumors, new biomarkers of the prometastatic microenvironment supported by the liver reaction to colon cancer factors may be helpful for the individual assessment of hepatic metastasis risk in colon cancer patients. In addition, knowledge on hepatic metastasis gene regulation by the hepatic microenvironment may open multiple opportunities for therapeutic intervention during colon cancer metastasis at both subclinical and advanced stages.
Also flagged:Cullin-RING ubiquitin ligasesdegradationcancerNedd8-activating enzymeconjugationcullin proteins
Journal Article2011-08-26No SnippetsLiao H, Liu XJ, Blank JL, Bouck DC, Bernard H, Garcia K, Lightcap ES.
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Cullin-RING ubiquitin ligases (CRLs) are responsible for the ubiquitination of many cellular proteins, thereby targeting them for proteasomal degradation. In most cases the substrates of the CRLs have not been identified, although many of those that are known have cancer relevance. MLN4924, an investigational small molecule that is a potent and selective inhibitor of the Nedd8-activating enzyme (NAE), is currently being explored in Phase I clinical trials. Inhibition of Nedd8-activating enzyme by MLN4924 prevents the conjugation of cullin proteins with NEDD8, resulting in inactivation of the entire family of CRLs. We have performed stable isotope labeling with amino acids in cell culture analysis of A375 melanoma cells treated with MLN4924 to identify new CRL substrates, confidently identifying and quantitating 5122-6012 proteins per time point. Proteins such as MLX, EID1, KLF5, ORC6L, MAGEA6, MORF4L2, MRFAP1, MORF4L1, and TAX1BP1 are rapidly stabilized by MLN4924, suggesting that they are novel CRL substrates. Proteins up-regulated at later times were also identified and siRNA against their corresponding genes were used to evaluate their influence on MLN4924-induced cell death. Thirty-eight proteins were identified as being particularly important for the cytotoxicity of MLN4924. Strikingly, these proteins had roles in cell cycle, DNA damage repair, and ubiquitin transfer. Therefore, the combination of RNAi with stable isotope labeling with amino acids in cell culture provides a paradigm for understanding the mechanism of action of novel agents affecting the ubiquitin proteasome system and a path to identifying mechanistic biomarkers.
Also flagged:RKIPTumourRaf kinase inhibitory proteinbreast tumourgene expressionHMGA2
Journal Article2011-08-26✓ 4 SnippetsYun J, Frankenberger CA, Kuo WL, Boelens MC, Eves EM, Cheng N, Liang H, Li WH, Li WH, Ishwaran H, Minn AJ, Rosner MR.
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Abstract)
…An RKIP pathway metastasis signature (designated RPMS) derived from the complete signalling cascade predicts high metastatic risk better than the individual genes.…
Title)
…Signalling pathway for RKIP and Let-7 regulates and predicts metastatic breast cancer.…
Abstract)
…Here, we demonstrate an integrated approach combining statistical analysis of breast tumour gene expression data and experimental validation to extend the signalling pathway for RKIP.…
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Tumour metastasis suppressors are inhibitors of metastasis but their mechanisms of action are generally not understood. We previously showed that the suppressor Raf kinase inhibitory protein (RKIP) inhibits breast tumour metastasis in part via let-7. Here, we demonstrate an integrated approach combining statistical analysis of breast tumour gene expression data and experimental validation to extend the signalling pathway for RKIP. We show that RKIP inhibits let-7 targets (HMGA2, BACH1) that in turn upregulate bone metastasis genes (MMP1, OPN, CXCR4). Our results reveal BACH1 as a novel let-7-regulated transcription factor that induces matrix metalloproteinase1 (MMP1) expression and promotes metastasis. An RKIP pathway metastasis signature (designated RPMS) derived from the complete signalling cascade predicts high metastatic risk better than the individual genes. These results highlight a powerful approach for identifying signalling pathways downstream of a key metastasis suppressor and indicate that analysis of genes in the context of their signalling environment is critical for understanding their predictive and therapeutic potential.
<h4>Aims</h4>Erythropoietin stimulating agents (ESAs) is an active area of clinical investigation in heart failure (HF) but can cause hypertension and higher hemoglobin concentrations (Hb) that have been associated with adverse outcomes. We evaluated a dosing algorithm and potential confounders' effect on Hb and blood pressure (BP) in a clinical trial.<h4>Methods</h4>In an ongoing randomized, placebo controlled, single blind clinical trial of ESA (epoetin alfa) in anemic patients with HF and a preserved ejection fraction (HFPEF), Hb was measured weekly as was BP, weight and concomitant medical therapy. A repeated measure mixed model evaluated determinants of weekly changes in Hb and BP.<h4>Results</h4>Among 45 subjects (78 ± 11 years, 67% women, EF = 57 ± 9%) with a total of 780 repeated weekly Hb measures, Hb significantly increased over time in those assigned to ESA (β = 0.933, P < 0.0001), compared to placebo. Dose (β = -0.108, P < 0.0001), patient weight (β = -0.016, P = 0.0037), diuretic use (β = -0.124, P = 0.0389), and time (β = 0.003, P = 0.0331), were all significantly associated with Hb change. Increased diuretic dose and weight change were significantly inversely associated with changes in Hb. ESA administration and dose were not significant determinants of absolute BP or changes in BP from baseline.<h4>Discussion</h4>In addition to ESA dose and duration of therapy, factors indicative of volume status including weight and diuretic use are determinants of hemoglobin levels in HF subjects.<h4>Conclusion</h4>The currently employed dosing algorithm, which adjusts the administration of ESA based on the absolute hemoglobin and weekly change in hemoglobin increases Hb with relatively a low weekly dose of ESA without significant effects on BP.
Also flagged:Huntington's diseaseHDtranscription factorsluciferasep65p53
Journal Article2011-08-26✓ 5 SnippetsGhose J, Sinha M, Das E, Jana NR, Bhattacharyya NP.
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Abstract)
…We conclude that (i) miR-125b and miR-150 target p53, which in turn regulates RelA/NFkB and miR-146a expressions; (ii) reduced miR-125b and miR-150 expressions, increased p53 level and decreased RelA/NFkB and miR-146a expressions originate from mutant HTT (iii) p53 directly or indirectly regulates the expression of miR-146a.…
Abstract)
…Deregulated microRNAs and loss of function of transcription factors recruited to mutant HTT aggregates could cause characteristic transcriptional deregulation associated with HD.…
Results)
…To address the specificity of such alteration of miR-146a, miR-125b and miR-150 in the presence of poly Q aggregates, mutated exon1 of HTT gene that translated to N-terminal HTT with 83 Q was exogenously expressed in four different cell lines viz., Neuro2A (mouse neuroblastoma cell line), STHdhQ7/HdhQ7 (mouse sriatal cells having two copies of full length HTT with 7Q), SH-SY5Y (human neuroblastoma cell line) and HeLa cells (human cells derived from cervical tumours) and the expression of twenty two miRNAs were studied in these cell models (Table S1).…
Introduction)
…Transcription factors (TFs) like TBP, CBP, p53, Sp1, NFkB and others are recruited to aggregates formed by mutant HTT, the hallmark of HD [4]–[9].…
Methods)
…STHdhQ111/HdhQ111 cells exhibit dominant HD phenotypes and indicate a disruption of striatal cell homeostasis by the mutant HTT protein, via a mechanism that is different from its normal activity (STHdhQ7/HdhQ7 cells).…
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Huntington's disease (HD) is caused by the expansion of N-terminal polymorphic poly Q stretch of the protein huntingtin (HTT). Deregulated microRNAs and loss of function of transcription factors recruited to mutant HTT aggregates could cause characteristic transcriptional deregulation associated with HD. We observed earlier that expressions of miR-125b, miR-146a and miR-150 are decreased in STHdh(Q111)/Hdh(Q111) cells, a model for HD in comparison to those of wild type STHdh(Q7)/Hdh(Q7) cells. In the present manuscript, we show by luciferase reporter assays and real time PCR that decreased miR-146a expression in STHdh(Q111)/Hdh(Q111) cells is due to decreased expression and activity of p65 subunit of NFkB (RelA/NFkB). By reporter luciferase assay, RT-PCR and western blot analysis, we also show that both miR-150 and miR-125b target p53. This partially explains the up regulation of p53 observed in HD. Elevated p53 interacts with RelA/NFkB, reduces its expression and activity and decreases the expression of miR-146a, while knocking down p53 increases RelA/NFkB and miR-146a expressions. We also demonstrate that expression of p53 is increased and levels of RelA/NFkB, miR-146a, miR-150 and miR-125b are decreased in striatum of R6/2 mice, a mouse model of HD and in cell models of HD. In a cell model, this effect could be reversed by exogenous expression of chaperone like proteins HYPK and Hsp70. We conclude that (i) miR-125b and miR-150 target p53, which in turn regulates RelA/NFkB and miR-146a expressions; (ii) reduced miR-125b and miR-150 expressions, increased p53 level and decreased RelA/NFkB and miR-146a expressions originate from mutant HTT (iii) p53 directly or indirectly regulates the expression of miR-146a. Our observation of interplay between transcription factors and miRNAs using HD cell model provides an important platform upon which further work is to be done to establish if such regulation plays any role in HD pathogenesis.
Also flagged:Gene expressiontyrosine kinaseBcr-Abl kinasechronic myelogenous leukemianilotinibimatinib
Journal Article2011-08-26No SnippetsKim TM, Ha SA, Kim HK, Yoo J, Kim S, Yim SH, Jung SH, Kim DW, Chung YJ, Kim JW.
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The use of selective inhibitors targeting Bcr-Abl kinase is now established as a standard protocol in the treatment of chronic myelogenous leukemia; however, the acquisition of drug resistance is a major obstacle limiting the treatment efficacy. To elucidate the molecular mechanism of drug resistance, we established K562 cell line models resistant to nilotinib and imatinib. Microarray-based transcriptome profiling of resistant cells revealed that nilotinib- and imatinib-resistant cells showed the upregulation of kinase-encoding genes (AURKC, FYN, SYK, BTK and YES1). Among them, the upregulation of AURKC and FYN was observed both in nilotinib- and imatinib-resistant cells irrespective of exposure doses, while SYK, BTK and YES1 showed dose-dependent upregulation of expression. Upregulation of EGF and JAG1 oncogenes as well as genes encoding ATP-dependent drug efflux pump proteins such as ABCB1 was also observed in the resistant cells, which may confer alternative survival benefits. Functional gene set analysis revealed that molecular categories of 'ATPase activity', 'cell adhesion' or 'tyrosine kinase activity' were commonly activated in the resistant clones. Taken together, the transcriptome analysis of tyrosine kinase inhibitors (TKI)-resistant clones provides the insights into the mechanism of drug resistance, which can facilitate the development of an effective screening method as well as therapeutic intervention to deal with TKI resistance.
Also flagged:celiac diseaseHEFSH2B3HLAiron deficiency anemiaautoimmune disease
Journal Article2011-08-25✓ 1 SnippetAaron L.
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Abstract)
…C282Y mutation ofhemochromatosis, SH2B3 loci and…
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Many human genes have adapted to the constant threat of exposure to changing environmental conditions. Balancing selection is the result of an initial stage of positive selection that favors the spread in a population of a new allele until selection opposes its fixation and balanced situation is established. It is suggested that the disadvantageous celiac patients survived the last two millennias echo-catastrophes by adapting to the extreme temperature changes and their consequences in Europe. Genetic selective diversity induced by changing environment, enabled the celiac population to survive. Such a genetic positive selection is represented by the HEF C282Y mutation of hemochromatosis, SH2B3 loci and the HLA celiac disease-associated repertoire, enabling the celiac to overcome iron deficiency anemia and micro pathogen richness, respectively. The increased incidence of those evolutionary events in the celiac patients is a recent phenomenon that occurred in the latest era of the modern human history. The present hypothesis can shed light on additional selective genetic adaptations, echo catastrophe-driven that are at the basis of autoimmune disease-affected population survival and current expansion.
Also flagged:Down syndromechromosomedevelopmental cognitive disabilitiesdevelopmental cognitive disabilityCognitive deficitslong-term memory
Journal Article2011-08-25No SnippetsLiu C, Belichenko PV, Zhang L, Fu D, Kleschevnikov AM, Baldini A, Antonarakis SE, Mobley WC, Yu YE.
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Down syndrome (DS) is mainly caused by the presence of an extra copy of human chromosome 21 (Hsa21) and is a leading genetic cause for developmental cognitive disabilities in humans. The mouse is a premier model organism for DS because the regions on Hsa21 are syntenically conserved with three regions in the mouse genome, which are located on mouse chromosome 10 (Mmu10), Mmu16 and Mmu17. With the advance of chromosomal manipulation technologies, new mouse mutants have been generated to mimic DS at both the genotypic and phenotypic levels. Further mouse-based molecular genetic studies in the future may lead to the unraveling of the mechanisms underlying DS-associated developmental cognitive disabilities, which would lay the groundwork for developing effective treatments for this phenotypic manifestation. In this review, we will discuss recent progress and future challenges in modeling DS-associated developmental cognitive disability in mice with an emphasis on hippocampus-related phenotypes.
Also flagged:acetylcholinegrowth coneaxonsynthesissecretionAVM
Journal Article2011-08-25No SnippetsXu Y, Ren XC, Quinn CC, Wadsworth WG.
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Gradients of acetylcholine can stimulate growth cone turning when applied to neurons grown in culture, and it has been suggested that acetylcholine could act as a guidance cue. However, the role acetylcholine plays in directing axon migrations in vivo is not clear. Here, we show that acetylcholine positively regulates signaling pathways that mediate axon responses to guidance cues in Caenorhabditis elegans. Mutations that disrupt acetylcholine synthesis, transportation, and secretion affect circumferential axon guidance of the AVM neuron and in these mutants exogenously supplied acetylcholine improves AVM circumferential axon guidance. These effects are not observed for the circumferential guidance of the DD and VD motor neuron axons, which are neighbors of the AVM axon. Circumferential guidance is directed by the UNC-6 (netrin) and SLT-1 (slit) extracellular cues, and exogenously supplied acetylcholine can improve AVM axon guidance in mutants when either UNC-6- or SLT-1-induced signaling is disrupted, but not when both signaling pathways are perturbed. Not in any of the mutants does exogenously supplied acetylcholine improve DD and VD axon guidance. The ability of acetylcholine to enhance AVM axon guidance only in the presence of either UNC-6 or SLT-1 indicates that acetylcholine potentiates UNC-6 and SLT-1 guidance activity, rather than acting itself as a guidance cue. Together, our results show that for specific neurons acetylcholine plays an important role in vivo as a modulator of axon responses to guidance cues.
Dendrites and axons show precise targeting and spacing patterns for proper reception and transmission of information in the nervous system. Self-avoidance promotes complete territory coverage and nonoverlapping spacing between processes from the same cell [1, 2]. Neurons that lack Drosophila Down syndrome cell adhesion molecule 1 (Dscam1) show aberrant overlap, fasciculation, and accumulation of dendrites and axons, demonstrating a role in self-recognition and repulsion leading to self-avoidance [3-11]. Fasciculation and accumulation of processes suggested that Dscam1 might promote process spacing by counterbalancing developmental signals that otherwise promote self-association [9, 12]. Here we show that Dscam1 functions to counter Drosophila sensory neuron dendritic targeting signals provided by secreted Netrin-B and Frazzled, a netrin receptor. Loss of Dscam1 function resulted in aberrant dendrite accumulation at a Netrin-B-expressing target, whereas concomitant loss of Frazzled prevented accumulation and caused severe deficits in dendritic territory coverage. Netrin misexpression was sufficient to induce ectopic dendritic targeting in a Frazzled-dependent manner, whereas Dscam1 was required to prevent ectopic accumulation, consistent with separable roles for these receptors. Our results suggest that Dscam1-mediated self-avoidance counters extrinsic signals that are required for normal dendritic patterning, but whose action would otherwise favor neurite accumulation. Counterbalancing roles for Dscam1 may be deployed in diverse contexts during neural circuit formation.
Also flagged:HDHuntington's diseaseautosomal dominant neurodegenerative disorderpathogenesis
Journal Article2011-08-25✓ 5 SnippetsRuiz M, Déglon N.
In-Text Gene Mentions
Abstract)
…The ability to deliver mutant Htt to specific tissues has opened pathological processes to experimental analysis and allowed targeted therapeutic development in rodent and primate pre-clinical models.…
Abstract)
…Rodent studies have shown that overexpression of mutant human Htt in the striatum using adeno-associated virus or lentivirus vectors induces progressive neurodegeneration, which resembles that seen in HD.…
Abstract)
…Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by an expansion of CAG repeats in the huntingtin (Htt) gene.…
Abstract)
…in the huntingtin (Htt) gene.…
Abstract)
…of mutant humanHttin the striatum…
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Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by an expansion of CAG repeats in the huntingtin (Htt) gene. Despite intensive efforts devoted to investigating the mechanisms of its pathogenesis, effective treatments for this devastating disease remain unavailable. The lack of suitable models recapitulating the entire spectrum of the degenerative process has severely hindered the identification and validation of therapeutic strategies. The discovery that the degeneration in HD is caused by a mutation in a single gene has offered new opportunities to develop experimental models of HD, ranging from in vitro models to transgenic primates. However, recent advances in viral-vector technology provide promising alternatives based on the direct transfer of genes to selected sub-regions of the brain. Rodent studies have shown that overexpression of mutant human Htt in the striatum using adeno-associated virus or lentivirus vectors induces progressive neurodegeneration, which resembles that seen in HD. This article highlights progress made in modeling HD using viral vector gene transfer. We describe data obtained with of this highly flexible approach for the targeted overexpression of a disease-causing gene. The ability to deliver mutant Htt to specific tissues has opened pathological processes to experimental analysis and allowed targeted therapeutic development in rodent and primate pre-clinical models.
Deleterious mutations present a significant obstacle to adaptive evolution. Deleterious mutations can inhibit the spread of linked adaptive mutations through a population; conversely, adaptive substitutions can increase the frequency of linked deleterious mutations and even result in their fixation. To assess the impact of adaptive mutations on linked deleterious mutations, we examined the distribution of deleterious and neutral amino acid polymorphism in the human genome. Within genomic regions that show evidence of recent hitchhiking, we find fewer neutral but a similar number of deleterious SNPs compared to other genomic regions. The higher ratio of deleterious to neutral SNPs is consistent with simulated hitchhiking events and implies that positive selection eliminates some deleterious alleles and increases the frequency of others. The distribution of disease-associated alleles is also altered in hitchhiking regions. Disease alleles within hitchhiking regions have been associated with auto-immune disorders, metabolic diseases, cancers, and mental disorders. Our results suggest that positive selection has had a significant impact on deleterious polymorphism and may be partly responsible for the high frequency of certain human disease alleles.
Also flagged:insulin resistancediabetesinsulinIRhypertensionATP10A
Journal Article2011-08-25No SnippetsIrvin MR, Wineinger NE, Rice TK, Pajewski NM, Kabagambe EK, Gu CC, Pankow J, North KE, Wilk JB, Freedman BI, Franceschini N, Broeckel U, Tiwari HK, Arnett DK.
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African Americans have been understudied in genome wide association studies of diabetes and related traits. In the current study, we examined the joint association of single nucleotide polymorphisms (SNPs) and copy number variants (CNVs) with fasting insulin and an index of insulin resistance (HOMA-IR) in the HyperGEN study, a family based study with proband ascertainment for hypertension. This analysis is restricted to 1,040 African Americans without diabetes. We generated allele specific CNV genotypes at 872,243 autosomal loci using Birdsuite, a freely available multi-stage program. Joint tests of association for SNPs and CNVs were performed using linear mixed models adjusting for covariates and familial relationships. Our results highlight SNPs associated with fasting insulin and HOMA-IR (rs6576507 and rs8026527, 3.7*10(-7)≤P≤1.1*10(-5)) near ATPase, class V, type 10A (ATP10A), and the L Type voltage dependent calcium channel (CACNA1D, rs1401492, P≤5.2*10(-6)). ATP10A belongs to a family of aminophospholipid-transporting ATPases and has been associated with type 2 diabetes in mice. CACNA1D has been linked to pancreatic beta cell generation in mice. The two most significant copy variable markers (rs10277702 and rs361367; P<2.0*10(-4)) were in the beta variable region of the T-cell receptor gene (TCRVB). Human and mouse TCR has been shown to mimic insulin and its receptor and could contribute to insulin resistance. Our findings differ from genome wide association studies of fasting insulin and other diabetes related traits in European populations, highlighting the continued need to investigate unique genetic influences for understudied populations such as African Americans.
Also flagged:CrebbphematopoiesisItga4Msi2Tcf4Ep300
Journal Article2011-08-25✓ 1 SnippetLemieux ME, Cheng Z, Zhou Q, White R, Cornell J, Kung AL, Rebel VI.
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…(e.g. Dhcr7 ,Mllt10where the slope…
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Global expression analysis of fetal liver hematopoietic stem cells (FL HSCs) revealed the presence of unspliced pre-mRNA for a number of genes in normal FL HSCs. In a subset of these genes, Crebbp+/- FL HSCs had less unprocessed pre-mRNA without a corresponding reduction in total mRNA levels. Among the genes thus identified were the key regulators of HSC function Itga4, Msi2 and Tcf4. A similar but much weaker effect was apparent in Ep300+/- FL HSCs, indicating that, in this context as in others, the two paralogs are not interchangeable. As a group, the down-regulated intronic probe sets could discriminate adult HSCs from more mature cell types, suggesting that the underlying mechanism is regulated with differentiation stage and is active in both fetal and adult hematopoiesis. Consistent with increased myelopoiesis in Crebbp hemizygous mice, targeted reduction of CREBBP abundance by shRNA in the multipotent EML cell line triggered spontaneous myeloid differentiation in the absence of the normally required inductive signals. In addition, differences in protein levels between phenotypically distinct EML subpopulations were better predicted by taking into account not only the total mRNA signal but also the amount of unspliced message present. CREBBP thus appears to selectively influence the timing and degree of pre-mRNA processing of genes essential for HSC regulation and thereby has the potential to alter subsequent cell fate decisions in HSCs.
Also flagged:mitochondrialHuntington's diseaseHDautosomal dominant neurodegenerative diseaseHuntingtintranscription factor
Journal Article2011-08-25✓ 5 SnippetsChiang MC, Chern Y, Huang RN.
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Abstract)
…Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by a CAG trinucleotide expansion in the Huntingtin (Htt) gene.…
Abstract)
…in the Huntingtin (Htt) gene.…
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…The resultant mutantHttprotein (mHtt) forms…
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…By reducingHttaggregates and thereby…
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…of PPARγ intoHttaggregates, TZD treatment…
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Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by a CAG trinucleotide expansion in the Huntingtin (Htt) gene. The resultant mutant Htt protein (mHtt) forms aggregates in the brain (e.g., cortex and striatum), and causes devastating neuronal degeneration. Transcriptional dysfunction caused by mHtt is critical for HD. We recently demonstrated that a crucial transcription factor peroxisome proliferator-activated receptor-γ (PPARγ) played a major function in the energy homeostasis observed in HD and that PPARγ is a potentially neuroprotective target for this disease. We report here that the transcript level of PPARγ was markedly downregulated in the cortex of a transgenic mouse model of HD (R6/2). Treatment of R6/2 mice with an agonist of PPARγ (thiazolidinedione, TZD) resulted in a beneficial effect on PPARγ. By reducing Htt aggregates and thereby ameliorating the recruitment of PPARγ into Htt aggregates, TZD treatment also elevated the availability of PPARγ level and subsequently normalized the expression of downstream genes (including PGC-1α and several mitochondrial genes) in the cortex. The above protective effects appeared to be exerted by a direct activation of the PPARγ agonist (rosiglitazone) because rosiglitazone protected a neuroblastoma cell line (N2A) from mHtt-evoked mitochondrial deficiency. Our results reveal that TZD and rosiglitazone may play a protective role in HD, and support the view that PPARγ is a potential therapeutic target in HD.
Also flagged:lung cancerACVR1Bhay feverNR4A1asthmachromosome
Journal Article2011-08-25No SnippetsSpitz MR, Gorlov IP, Amos CI, Dong Q, Chen W, Etzel CJ, Gorlova OY, Chang DW, Pu X, Zhang D, Wang L, Cunningham JM, Yang P, Wu X.
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Lung cancer in lifetime never smokers is distinct from that in smokers, but the role of separate or overlapping carcinogenic pathways has not been explored. We therefore evaluated a comprehensive panel of 11,737 single-nucleotide polymorphisms (SNP) in inflammatory-pathway genes in a discovery phase (451 lung cancer cases, 508 controls from Texas). SNPs that were significant were evaluated in a second external population (303 cases, 311 controls from the Mayo Clinic). An intronic SNP in the ACVR1B gene, rs12809597, was replicated with significance and restricted to those reporting adult exposure to environmental tobacco smoke. Another promising candidate was an SNP in NR4A1, although the replication OR did not achieve statistical significance. ACVR1B belongs to the TGFR-β superfamily, contributing to resolution of inflammation and initiation of airway remodeling. An inflammatory microenvironment (second-hand smoking, asthma, or hay fever) is necessary for risk from these gene variants to be expressed. These findings require further replication, followed by targeted resequencing, and functional validation.
Also flagged:Huntington's diseaseHDautosomal dominant inherited neurodegenerative disorderchromosomecognitivebehavioral
Journal Article2011-08-25✓ 1 SnippetWolf RC, Grön G, Sambataro F, Vasic N, Wolf ND, Thomann PA, Saft C, Landwehrmeyer GB, Orth M.
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Previous functional neuroimaging studies have shown brain activation abnormalities in clinically presymptomatic carriers of the Huntington's disease (preHD) gene mutation when performing complex cognitive tasks. However, little is known about the neural correlates of attentional processes in preHD. In this study, we used functional magnetic resonance imaging to investigate basic aspects of attentional processing in preHD individuals (n = 18) compared to healthy participants (n = 18) during an alertness task. Uni- and multivariate statistical techniques were used to assess task-related regional brain activation and functional network connectivity. Compared to healthy controls, preHD individuals near to the estimated onset of clinical signs showed lower activation of right frontostriatal regions during phasic alertness (P < 0.001, uncorrected). Decreased striatal activation in this preHD subgroup was also evident when compared with those preHD individuals far from the estimated onset of HD signs. Lower putaminal activity was associated with longer reaction times and with proximity to onset. In addition, preHD participants near to onset had lower functional connectivity of motor regions when compared with controls and preHD individuals far from onset. Our data suggest that while alertness-related performance remains normal, the underlying frontostriatal activity and motor cortex connectivity decline only when approaching the onset of unequivocal signs of HD. However, these attentional network changes might not be the sole explanation for the differences in cognitive task performance previously observed in preHD.
Also flagged:glaucomaGpnmbpathogenesisGene Expressionneurodegenerative diseaseneurodegenerative disorder
Journal Article2011-08-24No SnippetsHowell GR, Walton DO, King BL, Libby RT, John SW.
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<h4>Background</h4>We introduce Glaucoma Discovery Platform (GDP), an online environment for facile visualization and interrogation of complex transcription profiling datasets for glaucoma. We also report the availability of Datgan, the suite of scripts that was developed to construct GDP. This reusable software system complements existing repositories such as NCBI GEO or EBI ArrayExpress as it allows the construction of searchable databases to maximize understanding of user-selected transcription profiling datasets.<h4>Description</h4>Datgan scripts were used to construct both the underlying data tables and the web interface that form GDP. GDP is populated using data from a mouse model of glaucoma. The data was generated using the DBA/2J strain, a widely used mouse model of glaucoma. The DBA/2J-Gpnmb+ strain provided a genetically matched control strain that does not develop glaucoma. We separately assessed both the retina and the optic nerve head, important tissues in glaucoma. We used hierarchical clustering to identify early molecular stages of glaucoma that could not be identified using morphological assessment of disease. GDP has two components. First, an interactive search and retrieve component provides the ability to assess gene(s) of interest in all identified stages of disease in both the retina and optic nerve head. The output is returned in graphical and tabular format with statistically significant differences highlighted for easy visual analysis. Second, a bulk download component allows lists of differentially expressed genes to be retrieved as a series of files compatible with Excel. To facilitate access to additional information available for genes of interest, GDP is linked to selected external resources including Mouse Genome Informatics and Online Medelian Inheritance in Man (OMIM).<h4>Conclusion</h4>Datgan-constructed databases allow user-friendly access to datasets that involve temporally ordered stages of disease or developmental stages. Datgan and GDP are available from http://glaucomadb.jax.org/glaucoma.
<h4>Background</h4>Making a definitive preoperative diagnosis of solitary pulmonary nodules (SPNs) found by CT has been a clinical challenge. We previously demonstrated that microRNAs (miRNAs) could be used as biomarkers for lung cancer diagnosis. Here we investigate whether plasma microRNAs are useful in identifying lung cancer among individuals with CT-detected SPNs.<h4>Methods</h4>By using quantitative reverse transcriptase PCR analysis, we first determine plasma expressions of five miRNAs in a training set of 32 patients with malignant SPNs, 33 subjects with benign SPNs, and 29 healthy smokers to define a panel of miRNAs that has high diagnostic efficiency for lung cancer. We then validate the miRNA panel in a testing set of 76 patients with malignant SPNs and 80 patients with benign SPNs.<h4>Results</h4>In the training set, miR-21 and miR-210 display higher plasma expression levels, whereas miR-486-5p has lower expression level in patients with malignant SPNs, as compared to subjects with benign SPNs and healthy controls (all P ≤ 0.001). A logistic regression model with the best prediction was built on the basis of miR-21, miR-210, and miR-486-5p. The three miRNAs used in combination produced the area under receiver operating characteristic curve at 0.86 in distinguishing lung tumors from benign SPNs with 75.00% sensitivity and 84.95% specificity. Validation of the miRNA panel in the testing set confirms their diagnostic value that yields significant improvement over any single one.<h4>Conclusions</h4>The plasma miRNAs provide potential circulating biomarkers for noninvasively diagnosing lung cancer among individuals with SPNs, and could be further evaluated in clinical trials.
Also flagged:APE1CysTween-20KCNU1OligonucleotideSPG3A
Journal Article2011-08-24✓ 4 SnippetsVascotto C, Bisetto E, Li M, Zeef LA, D'Ambrosio C, Domenis R, Comelli M, Delneri D, Scaloni A, Altieri F, Mavelli I, Quadrifoglio F, Kelley MR, Kelley MR, Tell G.
…dentified as peroxiredoxin-6 (PRDX6) and protein disulfide-isomer…
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…and interaction withPRDX6and PDIA3 may…
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Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1) protects cells from oxidative stress via the base excision repair pathway and as a redox transcriptional coactivator. It is required for tumor progression/metastasis, and its up-regulation is associated with cancer resistance. Loss of APE1 expression causes cell growth arrest, mitochondrial impairment, apoptosis, and alterations of the intracellular redox state and cytoskeletal structure. A detailed knowledge of the molecular mechanisms regulating its different activities is required to understand the APE1 function associated with cancer development and for targeting this protein in cancer therapy. To dissect these activities, we performed reconstitution experiments by using wild-type and various APE1 mutants. Our results suggest that the redox function is responsible for cell proliferation through the involvement of Cys-65 in mediating APE1 localization within mitochondria. C65S behaves as a loss-of-function mutation by affecting the in vivo folding of the protein and by causing a reduced accumulation in the intermembrane space of mitochondria, where the import protein Mia40 specifically interacts with APE1. Treatment of cells with (E)-3-(2-[5,6-dimethoxy-3-methyl-1,4-benzoquinonyl])-2-nonyl propenoic acid, a specific inhibitor of APE1 redox function through increased Cys-65 oxidation, confirm that Cys-65 controls APE1 subcellular trafficking and provides the basis for a new role for this residue.
Also flagged:tumorangiogenesissolid tumorshematologic malignanciesvascular endothelial growth factorthalidomide
Journal Article2011-08-24✓ 1 SnippetFan F, Schimming A, Jaeger D, Podar K.
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…In the late 1980s, Dr. Vogelstein postulated a paradigm of multistep carcinogenesis in CRC involving a progressive series of specific and well-defined genetic alterations in tumor suppressor genes (APC, p53, or DCC) and in oncogenes (K-Ras), which render normal mucosa to carcinoma [53, 54].…
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Tumorigenesis is a complex multistep process involving not only genetic and epigenetic changes in the tumor cell but also selective supportive conditions of the deregulated tumor microenvironment. One key compartment of the microenvironment is the vascular niche. The role of angiogenesis in solid tumors but also in hematologic malignancies is now well established. Research on angiogenesis in general, and vascular endothelial growth factor in particular, is a major focus in biomedicine and has led to the clinical approval of several antiangiogenic agents including thalidomide, bevacizumab, sorafenib, sunitinib, pazopanib, temesirolimus, and everolimus. Indeed, antiangiogenic agents have significantly changed treatment strategies in solid tumors (colorectal cancer, renal cell carcinoma, and breast cancer) and multiple myeloma. Here we illustrate important aspects in the interrelationship between tumor cells and the microenvironment leading to tumor progression, with focus on angiogenesis, and summarize derived targeted therapies.
Also flagged:Huntington's DiseaseHDneurodegenerative disorderneurodegenerative diseasesimmune responsecognition
Journal Article2011-08-24✓ 5 SnippetsNayak A, Ansar R, Verma SK, Bonifati DM, Kishore U.
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Discussion)
…In vitro, Htt-containing cytoplasmic vacuoles contain the lysosomal enzyme cathepsin D, thus suggesting the role of autophagy in HD [43].…
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…Mouse models of HD (R6/2 transgenic mice) that exhibit a HD phenotype have shown expression of mutant Htt within glial cells, especially in astrocytes.…
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…However in HD, the precise mechanism by which the mutant Htt could lead to region-specific neuronal death is still unclear.…
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…Mutant Htt is known to be a key factor in promoting inflammation in HD, either directly or indirectly.…
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…This intranuclear expression of mutant Htt has been suggested to lead to degeneration of the medium sized spiny neurons in the striatum of the HD brain [39] and also exacerbate the neurological symptoms [40].…
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Huntington's disease (HD) is a progressive neurodegenerative disorder that is caused by abnormal expansion of CAG trinucleotide repeats. Neuroinflammation is a typical feature of most neurodegenerative diseases that leads to an array of pathological changes within the affected areas in the brain. The neurodegeneration in HD is also caused by aberrant immune response in the presence of aggregated mutant huntingtin protein. The effects of immune activation in HD nervous system are a relatively unexplored area of research. This paper summarises immunological features associated with development and progression of HD.
Also flagged:cytosoldegradationproteasomebiotin-ligasebiotintrans-membrane protein
Journal Article2011-08-24No SnippetsPetris G, Vecchi L, Bestagno M, Burrone OR.
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Retro-translocation from the ER to the cytosol of proteins within the secretory pathway takes place on misfolded molecules that are targeted for degradation by the cytosolically located 26S proteasome complex. Retro-translocation occurs also for other proteins (such as calreticulin) that, despite being synthesized and transported to the ER, are in part dislocated to the cytosol. We have taken advantage of the E. coli derived biotin-ligase (BirA) expressed in the cytosol of mammalian cells to specifically biotin-label in vivo proteins within the secretory pathway that undergo retro-translocation. We validated the method using four different proteins that are known to undergo retro-translocation upon different conditions: the human trans-membrane protein MHC class-I α chain (MHC-Iα), the Null Hong Kong mutant of the secretory α1 anti-trypsin (NHK-α1AT), the immunoglobulin heavy chain (HC) and the ER chaperone calreticulin (Crt). We observed specific mono-biotinylation of cytosolically dislocated molecules, resulting in a novel, reliable way of determining the extent of retro-translocation.
Also flagged:schistosomiasisinfectionbindingpeptidesmetabolismpathogenesis
Journal Article2011-08-24✓ 1 SnippetLiao Q, Yuan X, Xiao H, Liu C, Lv Z, Zhao Y, Wu Z.
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…peroxiredoxin 6 (PRDX6), which is…
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Schistosoma japonicum is a major infectious agent of schistosomiasis. It has been reported that large number of proteins excreted and secreted by S. japonicum during its life cycle are important for its infection and survival in definitive hosts. These proteins can be used as ideal candidates for vaccines or drug targets. In this work, we analyzed the protein sequences of S. japonicum and found that compared with other proteins in S. japonicum, excretory/secretory (ES) proteins are generally longer, more likely to be stable and enzyme, more likely to contain immune-related binding peptides and more likely to be involved in regulation and metabolism processes. Based on the sequence difference between ES and non-ES proteins, we trained a support vector machine (SVM) with much higher accuracy than existing approaches. Using this SVM, we identified 191 new ES proteins in S. japonicum, and further predicted 7 potential interactions between these ES proteins and human immune proteins. Our results are useful to understand the pathogenesis of schistosomiasis and can serve as a new resource for vaccine or drug targets discovery for anti-schistosome.
Also flagged:Kelch-like 20hypoxia-inducible factor-2αvon Hippel-Lindau tumor suppressor proteinhypoxia-inducible factor(HIF)-1αHIF-2α
Journal Article2011-08-24✓ 5 SnippetsHigashimura Y, Terai T, Yamaji R, Mitani T, Ogawa M, Harada N, Inui H, Nakano Y.
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Abstract)
…These results indicate that KLHL20 is a novel player that regulates HIF-2α protein expression through mechanisms independent of hypoxia and pVHL.…
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…KLHL20 decreased hypoxia…
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…KLHL20 is a novel player that regulates HIF-2α protein expression through mechanisms independent of hypoxia…
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…identified kelch-like 20 (KLHL20).…
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…HIF-1α, interacted withKLHL20.…
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Despite their structural similarity, hypoxia-inducible factor (HIF)-1α and HIF-2α have distinct functional properties and exhibit distinct spatiotemporal expression patterns, suggesting that the expressions of the two proteins are regulated by different mechanisms. To clarify the HIF-2α-specific regulatory mechanism, we screened HIF-2α-associated proteins in a yeast two-hybrid system and identified kelch-like 20 (KLHL20). HIF-2α, but not HIF-1α, interacted with KLHL20. siRNA-mediated knockdown of KLHL20 decreased HIF-2α protein, but not HIF-2α mRNA or HIF-1α protein. Depletion of KLHL20 decreased hypoxia-induced HIF activity, and consequently resulted in decreased expression levels of HIF-2α-responsive genes such as VEGF and CITED2. In contrast, overexpression of KLHL20 increased the expression levels and transcriptional activities of the O(2)-sensitive wild-type and O(2)-insensitive mutant forms of HIF-2α. KLHL20 siRNA also inhibited HIF-2 activity in von Hippel-Lindau tumor suppressor protein (pVHL)-deficient 786-O cells. These results indicate that KLHL20 is a novel player that regulates HIF-2α protein expression through mechanisms independent of hypoxia and pVHL.
The vertebrate vasculature forms an extensive branched network of blood vessels that supplies tissues with nutrients and oxygen. During vascular development, coordinated control of endothelial cell behaviour at the levels of cell migration, proliferation, polarity, differentiation and cell-cell communication is critical for functional blood vessel morphogenesis. Recent data uncover elaborate transcriptional, post-transcriptional and post-translational mechanisms that fine-tune key signalling pathways (such as the vascular endothelial growth factor and Notch pathways) to control endothelial cell behaviour during blood vessel sprouting (angiogenesis). These emerging frameworks controlling angiogenesis provide unique insights into fundamental biological processes common to other systems, such as tissue branching morphogenesis, mechanotransduction and tubulogenesis.
The design, synthesis, and biological evaluation of conformationally constrained coumermycin A1 analogues are reported. Compounds were evaluated against both breast cancer (SKBr3 and MCF7) and prostate cancer (PC3 mm2, A549, and HT29) cell lines. Non-noviosylated coumermycin A1 analogues that manifest potent antiproliferative activity resulting from Hsp90 inhibition are provided, wherein replacement of the stereochemically complex noviose sugar with readily available piperidine rings resulted in ∼100 fold increase in antiproliferative activities as compared to coumermycin A1, producing small molecule Hsp90 inhibitors that exhibit nanomolar activities.
Also flagged:MUC1estrogen receptorMucin 1lung adenocarcinomabreast cancerER
Journal Article2011-08-23No SnippetsKlinge CM, Radde BN, Imbert-Fernandez Y, Teng Y, Ivanova MM, Abner SM, Martin AL.
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Mucin 1 (MUC1) is a diagnostic factor and therapy target in lung adenocarcinoma. MUC1 C-terminal intracellular domain (CD) interacts with estrogen receptor (ER) α and increases gene transcription in breast cancer cells. Because lung adenocarcinoma cells express functional ERα and ERβ, we examined MUC1 expression and MUC1-ER interaction. Because blocking MUC1 CD with an inhibitory peptide (PMIP) inhibited breast tumor growth, we tested whether PMIP would inhibit lung adenocarcinoma cell proliferation. We report that MUC1 interacts with ERα and ERβ within the nucleus of H1793 lung adenocarcinoma cells in accordance with MUC1 expression. PMIP was taken up by H23 and H1793 cells and inhibited the proliferation of H1793, but not H23 cells, concordant with higher MUC1 protein expression in H1793 cells. Lower MUC1 protein expression in H23 does not correspond to microRNAs miR-125b and miR-145 that have been reported to reduce MUC1 expression. PMIP had no effect on the viability of normal human bronchial epithelial cells, which lack MUC1 expression. PMIP inhibited estradiol-activated reporter gene transcription and endogenous cyclin D1 and nuclear respiratory factor-1 gene transcription in H1793 cells. These results indicate MUC1-ER functional interaction in lung adenocarcinoma cells and that inhibiting MUC1 inhibits lung adenocarcinoma cell viability.
Also flagged:sterollipoproteincoronary heart diseaseexcretionIDOLLDL dyslipidemias
Journal Article2011-08-23No SnippetsCalandra S, Tarugi P, Speedy HE, Dean AF, Bertolini S, Shoulders CC.
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This review integrates historical biochemical and modern genetic findings that underpin our understanding of the low-density lipoprotein (LDL) dyslipidemias that bear on human disease. These range from life-threatening conditions of infancy through severe coronary heart disease of young adulthood, to indolent disorders of middle- and old-age. We particularly focus on the biological aspects of those gene mutations and variants that impact on sterol absorption and hepatobiliary excretion via specific membrane transporter systems (NPC1L1, ABCG5/8); the incorporation of dietary sterols (MTP) and of de novo synthesized lipids (HMGCR, TRIB1) into apoB-containing lipoproteins (APOB) and their release into the circulation (ANGPTL3, SARA2, SORT1); and receptor-mediated uptake of LDL and of intestinal and hepatic-derived lipoprotein remnants (LDLR, APOB, APOE, LDLRAP1, PCSK9, IDOL). The insights gained from integrating the wealth of genetic data with biological processes have important implications for the classification of clinical and presymptomatic diagnoses of traditional LDL dyslipidemias, sitosterolemia, and newly emerging phenotypes, as well as their management through both nutritional and pharmaceutical means.
Also flagged:SERPING1hereditary angioedemaC1Inh) deficiencyHAE types Iangioedema
Journal Article2011-08-23✓ 1 SnippetLópez-Lera A, Garrido S, Roche O, López-Trascasa M.
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Abstract)
…angioedema due toC1 InhibitorInhibitor (C1Inh) deficiency…
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Hereditary angioedema due to C1 Inhibitor (C1Inh) deficiency (HAE types I and II) is a rare, life-threatening disease causing spontaneous edema of the submucosal layers. A cohort of 127 individuals with symptoms of recurrent familial angioedema from 59 non-related families was studied. All the patients included fulfilled the diagnostic and biochemical criteria of HAE, including low C1Inh function and/or concentration. Genetic studies were carried out by PCR and sequencing of the C1NH locus followed, in the negative cases, by MLPA, long-range PCR and restriction enzyme analysis of genomic DNA to detect potential large rearrangements. Mutations located in consensus splicing sequences or nearby positions were studied by RT-PCR. The study identified 52 different mutations (25 missense, 15 frameshift, 7 splicing defects and 5 large deletions) responsible for the disease in 56 HAE families. In the remaining three families no molecular alteration could be detected. Twenty-seven of the mutations in this cohort are novel and 10 are confirmed de novo cases. The pathologic effect of the 5 splicing defects first reported here was assessed at the RNA and protein levels. Large deletions affecting exons 4 and 7, ranging from approximately 1500 to 2500 bp, were partially characterized by their altered restriction patterns upon long-range amplification. These results highlight the heterogeneity of mutations in the C1NH gene causing C1Inh deficiency and HAE. An approach to the molecular effects associated to each of the mutations reported here was made when possible based on the available data of pathological variants of serpins.
Also flagged:neurotransmittervoltage-gated Ca 2+ channelsR-type voltage-gated Ca 2+ channelsCa 2+ channelsNi 2-
Journal Article2011-08-23No SnippetsAlnawaiseh M, Albanna W, Chen CC, Campbell KP, Hescheler J, Lüke M, Schneider T.
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<h4>Purpose</h4>Light-evoked responses from vertebrate retinas were recorded as an electroretinogram (ERG). The b-wave is the most prominent component of the ERG, and in the bovine retina its NiCl(2) -sensitive component was attributed to reciprocal signalling by pharmacoresistant R-type voltage-gated Ca(2+) channels, which similar to other voltage-dependent Ca(2+) channels trigger and control neurotransmitter release. The murine retina has the great advantage that the effect of gene inactivation for Ni(2+) -sensitive Ca(2+) channels can be analysed to prove or disprove that any of these Ca(2+) channels is involved in retinal signalling.<h4>Methods</h4>Superfused retinas from different murine genotypes lacking either one or both highly Ni(2+) -sensitive voltage-gated Ca(2+) channels were used to record their ex vivo ERGs.<h4>Results</h4>The isolated retinas from mice lacking Ca(v)2.3 R-type or Ca(v)3.2 T-type or both voltage-gated Ca(2+) channels were superfused with a NiCl(2) (15 μm) containing nutrient solution. The change in the b-wave amplitude and implicit time, caused by NiCl(2), was calculated as a difference spectrum and compared to data from control animals. From the results, it can be deduced that Ca(v)2.3 contributes rather to a later component in the b-wave response, while in the absence of Ca(v)3.2 the gain of Ni(2+) -mediated increase in the b-wave amplitude is significantly increased, probably due to a loss of reciprocal inhibition to photoreceptors. Thus, each of the Ni(2+)-sensitive Ca(2+) channels contributes to specific features of the b-wave response.<h4>Conclusion</h4>Both high-affinity Ni(2+)-sensitive Ca(2+) channels contribute to transretinal signalling. Based on the results from the double knockout mice, additional targets for NiCl(2) must contribute to transretinal signalling, which will be most important for the structurally similar physiologically more important heavy metal cation Zn(2+).
Also flagged:Hepatitis C virus infectioninterferonHCV infectionIFN-αIFNliver fibrosis
Journal Article2011-08-23No SnippetsTsuge M, Fujimoto Y, Hiraga N, Zhang Y, Ohnishi M, Kohno T, Abe H, Miki D, Imamura M, Takahashi S, Ochi H, Hayes CN, Miya F, Tsunoda T, Chayama K.
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<h4>Background and aims</h4>Recent studies indicate that hepatitis C virus (HCV) can modulate the expression of various genes including those involved in interferon signaling, and up-regulation of interferon-stimulated genes by HCV was reported to be strongly associated with treatment outcome. To expand our understanding of the molecular mechanism underlying treatment resistance, we analyzed the direct effects of interferon and/or HCV infection under immunodeficient conditions using cDNA microarray analysis of human hepatocyte chimeric mice.<h4>Methods</h4>Human serum containing HCV genotype 1b was injected into human hepatocyte chimeric mice. IFN-α was administered 8 weeks after inoculation, and 6 hours later human hepatocytes in the mouse livers were collected for microarray analysis.<h4>Results</h4>HCV infection induced a more than 3-fold change in the expression of 181 genes, especially genes related to Organismal Injury and Abnormalities, such as fibrosis or injury of the liver (P = 5.90E-16∼3.66E-03). IFN administration induced more than 3-fold up-regulation in the expression of 152 genes. Marked induction was observed in the anti-fibrotic chemokines such as CXCL9, suggesting that IFN treatment might lead not only to HCV eradication but also prevention and repair of liver fibrosis. HCV infection appeared to suppress interferon signaling via significant reduction in interferon-induced gene expression in several genes of the IFN signaling pathway, including Mx1, STAT1, and several members of the CXCL and IFI families (P = 6.0E-12). Genes associated with Antimicrobial Response and Inflammatory Response were also significantly repressed (P = 5.22×10(-10)∼1.95×10(-2)).<h4>Conclusions</h4>These results provide molecular insights into possible mechanisms used by HCV to evade innate immune responses, as well as novel therapeutic targets and a potential new indication for interferon therapy.
Also flagged:serotonin transporterAnxietybehavioralIodoantipyrinetransporterserotonin
Journal Article2011-08-23✓ 5 SnippetsPang RD, Wang Z, Klosinski LP, Guo Y, Herman DH, Celikel T, Dong HW, Holschneider DP.
In-Text Gene Mentions
Introduction)
…Individuals carrying the low expressing form of the 5-HTTLPR polymorphism (the ‘s’ or ‘LG’ allele), which is associated with reduced transcription of 5-HTT and reduced serotonin (5-HT) uptake [1], [2], appear to have increased susceptibility to anxiety [1], [3] and mood symptoms in the face of environmental adversity [4] for review see [5], but not all studies find an effect [6], [7].…
Introduction)
…the serotonin transporter (5-HTT) promoter region (5-HTTLPR)…
<h4>Background</h4>Serotonin transporter knockout mice have been a powerful tool in understanding the role played by the serotonin transporter in modulating physiological function and behavior. However, little work has examined brain function in this mouse model. We tested the hypothesis that male knockout mice show exaggerated limbic activation during exposure to an emotional stressor, similar to human subjects with genetically reduced transcription of the serotonin transporter.<h4>Methodology/principal findings</h4>Functional brain mapping using [(14)C]-iodoantipyrine was performed during recall of a fear conditioned tone. Regional cerebral blood flow was analyzed by statistical parametric mapping from autoradiographs of the three-dimensionally reconstructed brains. During recall, knockout mice compared to wild-type mice showed increased freezing, increased regional cerebral blood flow of the amygdala, insula, and barrel field somatosensory cortex, decreased regional cerebral blood flow of the ventral hippocampus, and conditioning-dependent alterations in regional cerebral blood flow in the medial prefrontal cortex (prelimbic, infralimbic, and cingulate). Anxiety tests relying on sensorimotor exploration showed a small (open field) or paradoxical effect (marble burying) of loss of the serotonin transporter on anxiety behavior, which may reflect known abnormalities in the knockout animal's sensory system. Experiments evaluating whisker function showed that knockout mice displayed impaired whisker sensation in the spontaneous gap crossing task and appetitive gap cross training.<h4>Conclusions</h4>This study is the first to demonstrate altered functional activation in the serotonin transporter knockout mice of critical nodes of the fear conditioning circuit. Alterations in whisker sensation and functional activation of barrel field somatosensory cortex extend earlier reports of barrel field abnormalities, which may confound behavioral measures relying on sensorimotor exploration.
Also flagged:Dextrandengue infectionsrenal disordersdengueproteoglycansglycosaminoglycans
Journal Article2011-08-23No SnippetsNguyen-Pouplin J, Pouplin T, Van TP, The TD, Thi DN, Farrar J, Tinh HT, Wills B.
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<h4>Background</h4>Although increased capillary permeability is the major clinical feature associated with severe dengue infections the mechanisms underlying this phenomenon remain unclear. Dextran clearance methodology has been used to investigate the molecular sieving properties of the microvasculature in clinical situations associated with altered permeability, including during pregnancy and in various renal disorders. In order to better understand the characteristics of the vascular leak associated with dengue we undertook formal dextran clearance studies in Vietnamese dengue patients and healthy volunteers.<h4>Methodology/principal findings</h4>We carried out serial clearance studies in 15 young adult males with acute dengue and evidence of vascular leakage a) during the phase of maximal leakage and b) one and three months later, as well as in 16 healthy control subjects. Interestingly we found no difference in the clearance profiles of neutral dextran solutions among the dengue patients at any time-point or in comparison to the healthy volunteers.<h4>Conclusions/significance</h4>The surface glycocalyx layer, a fibre-matrix of proteoglycans, glycosaminoglycans, and plasma proteins, forms a complex with the underlying endothelial cells to regulate plasma volume within circumscribed limits. It is likely that during dengue infections loss of plasma proteins from this layer alters the permeability characteristics of the complex; physical and/or electrostatic interactions between the dextran molecules and the glycocalyx structure may temporarily restore normal function, rendering the technique unsuitable for assessing permeability in these patients. The implications for resuscitation of patients with dengue shock syndrome (DSS) are potentially important. It is possible that continuous low-dose infusions of dextran may help to stabilize the permeability barrier in patients with profound or refractory shock, reducing the need for repeated boluses, limiting the total colloid volume required. Formal clinical studies should help to assess this strategy as an alternative to conventional fluid resuscitation for severe DSS.
Also flagged:methylacidbindingbenzaldehydebenzoic acidlysine
Journal Article2011-08-23No SnippetsMcBride WJ, D'Souza CA, Sharkey RM, Goldenberg DM.
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A new ([(18)F]AlF)(2+)-binding ligand that contains 1,4,7-triazacyclononane-1,4-diacetate (NODA) attached to a methyl phenylacetic acid group (MPA) was conjugated to N-(2-aminoethyl)maleimide (EM) to form NODA-MPAEM. The NODA-MPAEM was labeled with ([(18)F]AlF)(2+) at 105°C in 49-82% yield and conjugated at room temperature to an antibody Fab' fragment in 69-80% yield (total time ∼50min) and with retention of immunoreactivity. These data indicate that the rapid and simple [(18)F]AlF-labeling method can be easily adapted for preparing heat-sensitive compounds with (18)F quickly and in high yields.
Olfactory sensory neurons (OSNs) are thought to use activity-dependent and independent mechanisms to regulate the expression of axon guidance genes. However, defining the molecular mechanisms that underlie activity-dependent OSN guidance has remained elusive. Only a handful of genes have been identified whose expression is regulated by activity. Interestingly, all of these genes have been shown to play a role in OSN axon guidance, underscoring the importance of identifying other genes regulated by activity. Furthermore, studies suggest that more than one downstream mechanism regulates target gene expression. Thus, both the number of genes regulated by activity and how many total mechanisms control this expression are not well understood. Here we identify delta protocadherin 10 (pcdh10) as a gene regulated by activity. Delta protocadherins are members of the cadherin superfamily, and pcdh10 is known to be important for axon guidance during development. We show pcdh10 is expressed in the nasal epithelium and olfactory bulb in patterns consistent with providing guidance information to OSNs. We use naris occlusion, genetic manipulations, and pharmacological assays to show pcdh10 can be regulated by activity, consistent with activation via the cyclic nucleotide-gated channel. Transgenic analysis confirms a potential role for pcdh10 in OSN axon guidance.
Also flagged:gene expressionnitric oxideresponse to hydrostatic pressureoxygencytokinenuclear factor‐kappa B
Journal Article2011-08-23No SnippetsPeng HH, Kao CC, Chang SD, Chao AS, Chang YL, Wang CN, Cheng PJ, Lee YS, Wang TH, Wang HS.
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Labor and its associated pain are thought to have unique impacts on parturient women. The goal of this study was to investigate the effects of labor and associated pain on differential gene expression profiles in the maternal, fetal, and placental compartments. We used microarrays to analyze maternal blood (MB), fetal cord blood (CB), and placental tissue samples in pregnant women after term vaginal deliveries (laboring group) and in term pregnant women after scheduled Ceasarean sections (nonlaboring group). The upregulated genes in the MB of the laboring group are involved in cytokine and nuclear factor-kappa B signaling pathways, regulation of the networks of toll-like receptor 4, and suppressor of cytokine signaling 3. Upregulated genes in the CB of the laboring group are involved in responding to stress and stimuli by regulating the network genes of the T-cell receptor beta locus and the FK506 binding protein 8. Differentially expressed genes in the placenta of the laboring group are involved in nitric oxide transport, gas transport, response to hydrostatic pressure, oxygen transport, acute phase responses, and the tumor necrosis factor-mediated signaling pathway, which are important during the transient hypoxemia and hypoperfusion that occur in the placenta during uterine contractions. Interestingly, few of the genes exhibited simultaneous changes in all three compartments, indicating that different pathways and complex interactions may be involved in human labor. In conclusion, human labor and its associated pain elicit unique gene regulatory changes in MB, placenta, and CB.
Also flagged:neurodegenerative diseaseHDchoreacognitive impairmentpsychiatric disordersStriatal atrophy
Journal Article2011-08-23✓ 5 SnippetsRoze E, Cahill E, Martin E, Bonnet C, Vanhoutte P, Betuing S, Caboche J.
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S I O 001029)
…In vivo, in a rat model of HD based on lentiviral-mediated expression of Exp-HTT exon 1 in the striatum (De Almeida et al., 2002), an early and chronic treatment with the D2 antagonist, haloperidol decanoate, protects striatal neurons from Exp-HTT-induced dysfunction, and aggregates formation (Charvin et al., 2008).…
S I O 001029)
…Restoring MSK-1 expression and subsequent striatal H3 phosphorylation in an in vitro model system of HD protects against neuronal alteration induced by the Exp-HTT including neuritic retraction, aggregate formation, and neuronal death (Roze et al., 2008).…
S I O 001029)
…In addition, Dopamine potentiates Exp-HTT-mediated striatal neurons death through activation of the Rho/ROCK signaling pathway downstream D2R.…
S I O 001029)
…This interaction is altered in HD, due to Exp-HTT expression, which decreases axonal transport and the release of BDNF from cortical neurons to their terminals within the striatum (Figure 1).…
S I O 001029)
…Dopamine release from nigro-striatal inputs promotes oxidative stress via the production of reactive oxygen species (ROS), which potentiates activation of the pro-apoptotic JNK pathway induced by Exp-HTT.…
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Huntington's Disease (HD) is the most frequent neurodegenerative disease caused by an expansion of polyglutamines (CAG). The main clinical manifestations of HD are chorea, cognitive impairment, and psychiatric disorders. The transmission of HD is autosomal dominant with a complete penetrance. HD has a single genetic cause, a well-defined neuropathology, and informative pre-manifest genetic testing of the disease is available. Striatal atrophy begins as early as 15 years before disease onset and continues throughout the period of manifest illness. Therefore, patients could theoretically benefit from therapy at early stages of the disease. One important characteristic of HD is the striatal vulnerability to neurodegeneration, despite similar expression of the protein in other brain areas. Aggregation of the mutated Huntingtin (HTT), impaired axonal transport, excitotoxicity, transcriptional dysregulation as well as mitochondrial dysfunction, and energy deficits, are all part of the cellular events that underlie neuronal dysfunction and striatal death. Among these non-exclusive mechanisms, an alteration of striatal signaling is thought to orchestrate the downstream events involved in the cascade of striatal dysfunction.
Also flagged:retinal degenerationenhanced green fluorescent proteinGFPcone dystrophychromosomechorioretinal atrophy
Journal Article2011-08-22No SnippetsLipinski DM, Yusuf M, Barnard AR, Damant C, Charbel Issa P, Singh MS, Lee E, Davies WL, Volpi EV, MacLaren RE.
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PURPOSE. To characterize anatomically and functionally the retinal degeneration observed in a transgenic mouse line (OPN1LW-EGFP) expressing enhanced green fluorescent protein (EGFP) in a subpopulation of cone photoreceptors, and to map the location of the transgenic insertion. METHODS. An anatomic comparison of cone survival was carried out between wild type (WT) and transgenic mice at three postnatal time points (P80, P140, and P245). Retinal function was assessed at P245 by ERG and included an ultraviolet flicker stimulus to isolate S-cone function. Chromosomal mapping by FISH and high-resolution mapping on DNA fibers (Fiber-FISH) were performed to identify the location of the transgenic insertion. RESULTS. GFP expression was largely absent in S-cones. Cone numbers were significantly reduced in OPN1LW-EGFP mice at all time points compared to WT, with cone loss independent of GFP expression. Anatomic loss correlated with a functional deficit in dark- and light-adapted ERG responses, including a reduction in UV-flicker response, confirming the degeneration of S-cones. The phenotype of heterozygote mice was slightly less severe than in homozygotes, consistent with a dominantly inherited cone dystrophy. The transgenic insertion mapped to a specific region on chromosome 10 orthologous with loci for progressive bifocal chorioretinal atrophy and North Carolina macular dystrophy on human chromosome 6. CONCLUSIONS. Cone loss is global in OPN1LW-EGFP mice and is independent of GFP expression. The mechanism underlying the degeneration remains elusive; however, disruption of loci associated with dominantly inherited retinal degenerations in humans makes this mouse of great interest.
Also flagged:Heparan sulfateaxon guidanceExt1axonsbindingaxon
Journal Article2011-08-22✓ 1 SnippetOgata-Iwao M, Inatani M, Iwao K, Takihara Y, Nakaishi-Fukuchi Y, Irie F, Sato S, Furukawa T, Yamaguchi Y, Tanihara H.
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…DCC…
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PURPOSE. Heparan sulfate (HS) is abundantly expressed in the developing neural retina; however, its role in the intraretinal axon guidance of retinal ganglion cells (RGCs) remains unclear. In this study, the authors examined whether HS was essential for the axon guidance of RGCs toward the optic nerve head. METHODS. The authors conditionally ablated the gene encoding the exostosin-1 (Ext1) enzyme, using the dickkopf homolog 3 (Dkk3)-Cre transgene, which disrupted HS expression in the mouse retina during directed pathfinding by RGC axons toward the optic nerve head. In situ hybridization, immunohistochemistry, DiI tracing, binding assay, and retinal explant assays were performed to evaluate the phenotypes of the mutants and the roles of HS in intraretinal axon guidance. RESULTS. Despite no gross abnormality in RGC distribution, the mutant RGC axons exhibited severe intraretinal guidance errors, including optic nerve hypoplasia, ectopic axon penetration through the full thickness of the neural retina and into the subretinal space, and disturbance of the centrifugal projection of RGC axons toward the optic nerve head. These abnormal phenotypes shared similarities with the RGC axon misguidance caused by mutations of genes encoding Netrin-1 and Slit-1/2. Explant assays revealed that the mutant RGCs exhibited disturbed Netrin-1-dependent axon outgrowth and Slit-2-dependent repulsion. CONCLUSIONS. The present study demonstrated that RGC axon projection toward the optic nerve head requires the expression of HS in the neural retina, suggesting that HS in the retina functions as an essential modulator of Netrin-1 and Slit-mediated intraretinal RGC axon guidance.
Also flagged:chronic thromboembolic pulmonary hypertensionCTEPHendothelial-mesenchymal transitionautophagymitochondrial reticulumlocalization
Journal Article2011-08-22✓ 1 SnippetSakao S, Hao H, Tanabe N, Kasahara Y, Kurosu K, Tatsumi K.
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Results)
…CDKN2A, CTSB, HSP90AA1,HTT, IFNG, IGF1, INS,…
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<h4>Background</h4>Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by intravascular thrombus formation in the pulmonary arteries.Recently, it has been shown that a myofibroblast cell phenotype was predominant within endarterectomized tissues from CTEPH patients. Indeed, our recent study demonstrated the existence of not only myofibroblast-like cells (MFLCs), but also endothelial-like cells (ELCs). Under in vitro conditions, a few transitional cells (co-expressing both endothelial- and SM-cell markers) were observed in the ELC population. We hypothesized that MFLCs in the microenvironment created by the unresolved clot may promote the endothelial-mesenchymal transition and/or induce endothelial cell (EC) dysfunction.<h4>Methods</h4>We isolated cells from these tissues and identified them as MFLCs and ELCs. In order to test whether the MFLCs provide the microenvironment which causes EC alterations, ECs were incubated in serum-free medium conditioned by MFLCs, or were grown in co-culture with the MFLCs.<h4>Results</h4>Our experiments demonstrated that MFLCs promoted the commercially available ECs to transit to other mesenchymal phenotypes and/or induced EC dysfunction through inactivation of autophagy, disruption of the mitochondrial reticulum, alteration of the SOD-2 localization, and decreased ROS production. Indeed, ELCs included a few transitional cells, lost the ability to form autophagosomes, and had defective mitochondrial structure/function. Moreover, rapamycin reversed the phenotypic alterations and the gene expression changes in ECs co-cultured with MFLCs, thus suggesting that this agent had beneficial therapeutic effects on ECs in CTEPH tissues.<h4>Conclusions</h4>It is possible that the microenvironment created by the stabilized clot stimulates MFLCs to induce EC alterations.
Also flagged:host cellbinding120-kDa tandem repeat proteinantibodychromatinoligonucleotides
Journal Article2011-08-22No SnippetsZhu B, Kuriakose JA, Luo T, Ballesteros E, Gupta S, Fofanov Y, McBride JW.
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Ehrlichia chaffeensis is an obligately intracellular bacterium that modulates host cell gene transcription in the mononuclear phagocyte, but the host gene targets and mechanisms involved in transcriptional modulation are not well-defined. In this study, we identified a novel tandem repeat DNA-binding domain in the E. chaffeensis 120-kDa tandem repeat protein (TRP120) that directly binds host cell DNA. TRP120 was observed by immunofluorescent microscopy in the nucleus of E. chaffeensis-infected host cells and was detected in nuclear extracts by Western immunoblotting with TRP120-specific antibody. The TRP120 binding sites and associated host cell target genes were identified using high-throughput deep sequencing (Illumina) of immunoprecipitated DNA (chromatin immunoprecipitation and high-throughput DNA sequencing). Multiple em motif elicitation (MEME) analysis of the most highly enriched TRP120-bound sequences revealed a G+C-rich DNA motif, and recombinant TRP120 specifically bound synthetic oligonucleotides containing the motif. TRP120 target gene binding sites were mapped most frequently to intersecting regions (intron/exon; 49%) but were also identified in upstream regulatory regions (25%) and downstream locations (26%). Genes targeted by TRP120 were most frequently associated with transcriptional regulation, signal transduction, and apoptosis. TRP120 targeted inflammatory chemokine genes, CCL2, CCL20, and CXCL11, which were strongly upregulated during E. chaffeensis infection and were also upregulated by direct transfection with recombinant TRP120. This study reveals that TRP120 is a novel DNA-binding protein that is involved in a host gene transcriptional regulation strategy.
Also flagged:nucleusto lightdigestionalbuminlight-inducible proteinsvasopressin
Journal Article2011-08-22✓ 1 SnippetTian R, Alvarez-Saavedra M, Cheng HY, Figeys D.
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…HTT…
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In mammals, the suprachiasmatic nucleus (SCN) is the central circadian pacemaker that governs rhythmic fluctuations in behavior and physiology in a 24-hr cycle and synchronizes them to the external environment by daily resetting in response to light. The bilateral SCN is comprised of a mere ~20,000 neurons serving as cellular oscillators, a fact that has, until now, hindered the systematic study of the SCN on a global proteome level. Here we developed a fully automated and integrated proteomics platform, termed AutoProteome system, for an in-depth analysis of the light-responsive proteome of the murine SCN. All requisite steps for a large-scale proteomic study, including preconcentration, buffer exchanging, reduction, alkylation, digestion and online two-dimensional liquid chromatography-tandem MS analysis, are performed automatically on a standard liquid chromatography-MS system. As low as 2 ng of model protein bovine serum albumin and up to 20 μg and 200 μg of SCN proteins can be readily processed and analyzed by this system. From the SCN tissue of a single mouse, we were able to confidently identify 2131 proteins, of which 387 were light-regulated based on a spectral counts quantification approach. Bioinformatics analysis of the light-inducible proteins reveals their diverse distribution in different canonical pathways and their heavy connection in 19 protein interaction networks. The AutoProteome system identified vasopressin-neurophysin 2-copeptin and casein kinase 1 delta, both of which had been previously implicated in clock timing processes, as light-inducible proteins in the SCN. Ras-specific guanine nucleotide-releasing factor 1, ubiquitin protein ligase E3A, and X-linked ubiquitin specific protease 9, none of which had previously been implicated in SCN clock timing processes, were also identified in this study as light-inducible proteins. The AutoProteome system opens a new avenue to systematically explore the proteome-wide events that occur in the SCN, either in response to light or other stimuli, or as a consequence of its intrinsic pacemaker capacity.
Also flagged:thalidomideCRBNmyelomalenalidomidepomalidomidebortezomib
Journal Article2011-08-22No SnippetsZhu YX, Braggio E, Shi CX, Bruins LA, Schmidt JE, Van Wier S, Chang XB, Bjorklund CC, Fonseca R, Bergsagel PL, Orlowski RZ, Stewart AK.
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The precise molecular mechanism of action and targets through which thalidomide and related immunomodulatory drugs (IMiDs) exert their antitumor effects remains unclear. We investigated the role of cereblon (CRBN), a primary teratogenic target of thalidomide, in the antimyeloma activity of IMiDs. CRBN depletion is initially cytotoxic to human myeloma cells, but surviving cells with stable CRBN depletion become highly resistant to both lenalidomide and pomalidomide, but not to the unrelated drugs bortezomib, dexamethasone, and melphalan. Acquired deletion of CRBN was found to be the primary genetic event differentiating isogenic MM1.S cell lines cultured to be sensitive or resistant to lenalidomide and pomalidomide. Gene expression changes induced by lenalidomide were dramatically suppressed in the presence of CRBN depletion, further demonstrating that CRBN is required for lenalidomide activity. Downstream targets of CRBN include interferon regulatory factor 4 (IRF4) previously reported to also be a target of lenalidomide. Patients exposed to, and putatively resistant to, lenalidomide had lower CRBN levels in paired samples before and after therapy. In summary, CRBN is an essential requirement for IMiD activity and a possible biomarker for the clinical assessment of antimyeloma efficacy.
Also flagged:FOXORUNX1gene expressionForkhead box Otranscription factorstranscription factor
Journal Article2011-08-22✓ 1 SnippetWang L, Brugge JS, Janes KA.
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…PRDX6…
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Gene expression networks are complicated by the assortment of regulatory factors that bind DNA and modulate transcription combinatorially. Single-cell measurements can reveal biological mechanisms hidden by population averages, but their value has not been fully explored in the context of mRNA regulation. Here, we adapted a single-cell expression profiling technique to examine the gene expression program downstream of Forkhead box O (FOXO) transcription factors during 3D breast epithelial acinar morphogenesis. By analyzing patterns of mRNA fluctuations among individual matrix-attached epithelial cells, we found that a subset of FOXO target genes was jointly regulated by the transcription factor Runt-related transcription factor 1 (RUNX1). Knockdown of RUNX1 causes hyperproliferation and abnormal morphogenesis, both of which require normal FOXO function. Down-regulating RUNX1 and FOXOs simultaneously causes widespread oxidative stress, which arrests proliferation and restores normal acinar morphology. In hormone-negative breast cancers lacking human epidermal growth factor receptor 2 (HER2) amplification, we find that RUNX1 down-regulation is strongly associated with up-regulation of FOXO1, which may be required to support growth of RUNX1-negative tumors. The coordinate function of these two tumor suppressors may provide a failsafe mechanism that inhibits cancer progression.
Also flagged:embryogenesisSix1Six4gene expressionhomeoproteinsorganization
Journal Article2011-08-22✓ 1 SnippetRichard AF, Demignon J, Sakakibara I, Pujol J, Favier M, Strochlic L, Le Grand F, Sgarioto N, Guernec A, Schmitt A, Cagnard N, Huang R, Legay C, Guillet-Deniau I, Maire P.
In-Text Gene Mentions
Abstract)
…the transcription repressorSox6.…
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Adult skeletal muscles in vertebrates are composed of different types of myofibers endowed with distinct metabolic and contraction speed properties. Genesis of this fiber-type heterogeneity during development remains poorly known, at least in mammals. Six1 and Six4 homeoproteins of the Six/sine oculis family are expressed throughout muscle development in mice, and Six1 protein is enriched in the nuclei of adult fast-twitch myofibers. Furthermore, Six1/Six4 proteins are known to control the early activation of fast-type muscle genes in myocytes present in the mouse somitic myotome. Using double Six1:Six4 mutants (SixdKO) to dissect in vivo the genesis of muscle fiber-type heterogeneity, we analyzed here the phenotype of the dorsal/epaxial muscles remaining in SixdKO. We show by electron microscopy analysis that the absence of these homeoproteins precludes normal sarcomeric organization of the myofiber leading to a dystrophic aspect, and by immunohistochemistry experiments a deficiency in synaptogenesis. Affymetrix transcriptome analysis of the muscles remaining in E18.5 SixdKO identifies a major role for these homeoproteins in the control of genes that are specifically activated in the adult fast/glycolytic myofibers, particularly those controlling Ca(2+) homeostasis. Absence of Six1 and Six4 leads to the development of dorsal myofibers lacking expression of fast-type muscle genes, and mainly expressing a slow-type muscle program. The absence of restriction of the slow-type program during the fetal period in SixdKO back muscles is associated with a decreased HDAC4 protein level, and subcellular relocalization of the transcription repressor Sox6. Six genes thus behave as essential global regulators of muscle gene expression, as well as a central switch to drive the skeletal muscle fast phenotype during fetal development.
Also flagged:tyrosinepeptidesantibodiesbromineconjugationamines
Journal Article2011-08-22No SnippetsLang L, Li W, Jia HM, Fang DC, Zhang S, Sun X, Zhu L, Ma Y, Shen B, Kiesewetter DO, Niu G, Chen X.
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Direct bromination of the tyrosine residues of peptides and antibodies with bromine-76, to create probes for PET imaging, has been reported. For peptides that do not contain tyrosine residues, however, a prosthetic group is required to achieve labeling via conjugation to other functional groups such as terminal α-amines or lysine ε-amines. The goal of this study was to develop new strategies for labeling small peptides with Br-76 using either a direct labeling method or a prosthetic group, depending on the available functional group on the peptides. A new labeling agent, N-succinimidyl-3-[(76)Br]bromo-2,6-dimethoxybenzoate ([(76)Br]SBDMB) was prepared for cyclic RGD peptide labeling. N-succinimidyl-2, 6-dimethoxybenzoate was also used to pre-attach a 2, 6-dimethoxybenzoyl (DMB) moiety to the peptide, which could then be labeled with Br-76. A competitive cell binding assay was performed to determine the binding affinity of the brominated peptides. PET imaging of U87MG human glioblastoma xenografted mice was performed using [(76)Br]-BrE[c(RGDyK)](2) and [(76)Br]-BrDMB-E[c(RGDyK)](2). An ex vivo biodistribution assay was performed to confirm PET quantification. The mechanisms of bromination reaction between DMB-c(RGDyK) and the brominating agent CH(3)COOBr were investigated with the SCRF-B3LYP/6-31G* method with the Gaussian 09 program package. The yield for direct labeling of c(RGDyK) and E[c(RGDyK)](2) using chloramine-T and peracetic acid at ambient temperature was greater than 50%. The yield for [(76)Br]SBDMB was over 60% using peracetic acid. The conjugation yields for labeling c(RGDfK) and c(RGDyK) were over 70% using the prosthetic group at room temperature. Labeling yield for pre-conjugated peptides was over 60%. SDMB conjugation and bromination did not affect the binding affinity of the peptides with integrin receptors. Both [(76)Br]Br-E[c(RGDyK)](2) and [(76)Br]BrDMB-E[c(RGDyK)](2) showed high tumor uptake in U87MG tumor bearing mice. The specificity of the imaging tracers was confirmed by decreased tumor uptake after co-administration of unlabeled dimeric RGD peptides. The energy barrier of the transition state of bromination for the dimethoxybenzoyl group was about 9 kcal/mol lower than that for the tyrosine residue. In conclusion, the newly developed N-succinimidyl-2, 6-dimethoxybenzoate molecule can be used either for one step labeling through pre-conjugation or as the precursor for a Br-76 labeled prosthetic group for indirect labeling. Radiobromination on a dimethoxybenzoyl group has selectivity over radiobromination on tyrosine. The energy barrier difference of the transition states of bromination between the dimethoxybenzoyl group and the tyrosine residue may account for the reaction selectivity when both groups are present in the same molecule.
Also flagged:Iron disordersiron overload diseasesHepcidinironexcess disorderstransferrin receptor 2
Journal Article2011-08-20✓ 5 SnippetsBrissot P, Bardou-Jacquet E, Jouanolle AM, Loréal O.
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Abstract)
…Hepcidin deficiency underlies iron overload in HFE-hemochromatosis as well as in several other genetic iron excess disorders, such as hemojuvelin or hepcidin-related hemochromatosis and transferrin receptor 2-related hemochromatosis.…
Abstract)
…Hepcidin deficiency underlies iron overload in HFE-hemochromatosis as well a…
Abstract)
…most frequent beingHFE-related hemochromatosis.…
Abstract)
…frequent being HFE-relatedhemochromatosis.…
Abstract)
…iron overload inHFE-hemochromatosis as well as…
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Iron disorders of genetic origin are mainly composed of iron overload diseases, the most frequent being HFE-related hemochromatosis. Hepcidin deficiency underlies iron overload in HFE-hemochromatosis as well as in several other genetic iron excess disorders, such as hemojuvelin or hepcidin-related hemochromatosis and transferrin receptor 2-related hemochromatosis. Deficiency of ferroportin, the only known cellular protein iron exporter, produces iron overload in the typical form of ferroportin disease. By contrast, genetically enhanced hepcidin production, as observed in matriptase-2 deficiency, generates iron-refractory iron deficiency anemia. Diagnosis of these iron storage disorders is usually established noninvasively through combined biochemical, imaging and genetic approaches. Moreover, improved knowledge of the molecular mechanisms accounting for the variations of iron stores opens the way of novel therapeutic approaches aiming to restore normal iron homeostasis. In this review, we will summarize recent findings about these various genetic entities that have been identified owing to an exemplary interplay between clinicians and basic scientists.
The inner ear arises from multipotent placodal precursors that are gradually committed to the otic fate and further differentiate into all inner ear cell types, with the exception of a few immigrating neural crest-derived cells. The otocyst plays a pivotal role during inner ear development: otic progenitor cells sub-compartmentalize into non-sensory and prosensory domains, giving rise to individual vestibular and auditory organs and their associated ganglia. The genes and pathways underlying this progressive subdivision and differentiation process are not entirely known. The goal of this study was to identify a comprehensive set of genes expressed in the chicken otocyst using the serial analysis of gene expression (SAGE) method. Our analysis revealed several hundred transcriptional regulators, potential signaling proteins, and receptors. We identified a substantial collection of genes that were previously known in the context of inner ear development, but we also found many new candidate genes, such as SOX4, SOX5, SOX7, SOX8, SOX11, and SOX18, which previously were not known to be expressed in the developing inner ear. Despite its limitation of not being all-inclusive, the generated otocyst SAGE library is a practical bioinformatics tool to study otocyst gene expression and to identify candidate genes for developmental studies.
Copy number variants (CNVs) play an important role in human disease and population diversity. Advancements in technology have allowed for the analysis of CNVs in thousands of individuals with disease in addition to thousands of controls. These studies have identified rare CNVs associated with neuropsychiatric diseases such as autism, schizophrenia, and intellectual disability. In addition, copy number polymorphisms (CNPs) are present at higher frequencies in the population, show high diversity in copy number, sequence, and structure, and have been associated with multiple phenotypes, primarily related to immune or environmental response. However, the landscape of copy number variation still remains largely unexplored, especially for smaller CNVs and those embedded within complex regions of the human genome. An integrated approach including characterization of single nucleotide variants and CNVs in a large number of individuals with disease and normal genomes holds the promise of thoroughly elucidating the genetic basis of human disease and diversity.
Also flagged:caspase-2behavioralneurodegenerative disordercaspasepathogenesisHD
Journal Article2011-08-19✓ 5 SnippetsCarroll JB, Southwell AL, Graham RK, Lerch JP, Ehrnhoefer DE, Cao LP, Zhang WN, Deng Y, Bissada N, Henkelman RM, Hayden MR.
…Huntington disease (HD) is a neurodegenerative disorder characterized by progressive motor, cognitive and psychiatric deficits [1] caused by an expanded poly-glutamine tract in the huntingtin (HTT) protein [2].…
Introduction)
…While casp2 cleavage of HTT is thus unlikely to cause pathology in HD, other activities of casp2 may contribute to signs and symptoms of HD.…
Introduction)
…Supporting the latter hypothesis, mutation of obligate aspartate residues in the caspase recognition regions of HTT has established that cleavage at amino acid 586, a caspase-6 site in vitro, is crucial for the development of HD symptoms in a mouse model [18-20].…
Results)
…We have previously demonstrated that the aa586 caspase-6 fragment of HTT is uniquely linked to toxicity in the YAC128 model of HD [18-20].…
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<h4>Background</h4>Huntington Disease (HD) is a neurodegenerative disorder in which caspase activation and cleavage of substrates, including the huntingtin protein, has been invoked as a pathological mechanism. Specific changes in caspase-2 (casp2) activity have been suggested to contribute to the pathogenesis of HD, however unique casp2 cleavage substrates have remained elusive. We thus utilized mice completely lacking casp2 (casp2-/-) to examine the role played by casp2 in the progression of HD. This 'substrate agnostic' approach allows us to query the effect of casp2 on HD progression without pre-defining proteolytic substrates of interest.<h4>Results</h4>YAC128 HD model mice lacking casp2 show protection from well-validated motor and cognitive features of HD, including performance on rotarod, swimming T-maze, pre-pulse inhibition, spontaneous alternation and locomotor tasks. However, the specific pathological features of the YAC128 mice including striatal volume loss and testicular degeneration are unaltered in mice lacking casp2. The application of high-resolution magnetic resonance imaging (MRI) techniques validates specific neuropathology in the YAC128 mice that is not altered by ablation of casp2.<h4>Conclusions</h4>The rescue of behavioral phenotypes in the absence of pathological improvement suggests that different pathways may be operative in the dysfunction of neural circuitry in HD leading to behavioral changes compared to the processes leading to cell death and volume loss. Inhibition of caspase-2 activity may be associated with symptomatic improvement in HD.
<h4>Background/aim</h4>Hyperhomocysteinemia due to Methylenetetrahydrofolate Reductase (MTHFR) gene, in particular the C677T (Ala222Val) polymorphism were recently associated to steatosis and fibrosis. We analyzed the frequency of MTHFR gene in a cross-sectional study of patients affected by Chronic Hepatitis C (CHC) from Northeast of Brazil.<h4>Method</h4>One hundred seven-four untreated patients with CHC were genotyped for the C677T MTHFR. Genomic DNA was extracted from peripheral blood cells and the C677T MTHFR polymorphism was identified by PCR-RFLP. The homocysteine (Hcy) levels were determined by chemiluminescence method. All patients were negative for markers of Wilson's disease, hemochromatosis and autoimmune diseases and have current and past daily alcohol intake less than 100 g/week.<h4>Results</h4>Among subjects infected with CHC genotype non-1 the frequency of MTHFR genotypes TT was 9.8% versus 4.4% genotype 1 (p = 0.01). Nevertheless, association was found between the MTHFR genotype TT × CT/CC polymorphism and the degree of steatosis and fibrosis in both hepatitis C genotype (p < 0.05). A significant difference was found on plasma Hcy levels in patients with steatosis regardless of HCV genotype (p = 0.03).<h4>Conclusion</h4>Our results indicate that plasma Hcy levels is highly prevalent in subjects with chronic hepatits C with steatosis regardless of HCV genotype and vitamin deficiency. The presence of genotype TT of MTHFR C677T polymorphism was more common in CHC genotype non-1 infected patient regardless of histopathological classification and genotype TT+CT frequencies were significant in the presence of fibrosis grade 1+2 and of steatosis in CHC infected patients from the northeast of Brazil regardless of HCV genotype. The genetic susceptibility of MTHFR C677T polymorphism should be confirmed in a large population.
Potent glucocorticoids (GC) administered early in life have improved premature infant survival dramatically. However, these agents may increase the risk for physical, neurological and behavior alterations. Anxiety, depression and attention difficulties are commonly described in adolescent and young adult survivors of prematurity. In the present study we administered vehicle, dexamethasone, or hydrocortisone to Sprague-Dawley rat pups on postnatal days 5 and 6, mimicking a short term clinical protocol commonly used in human infants. Two systems that are implicated in the regulation of stress and behavior were assessed: the limbic-hypothalamic-pituitary-adrenal axis [LHPA; glucocorticoid and mineralocorticoid receptors within] and the Serotonin (5-HT) system. We found that as adults, male Sprague-Dawley pups treated with GC showed agent specific altered growth, anxiety-related behavior, changes in corticoid response to novelty and gene expression changes within LHPA and 5-HT-related circuitry. The data suggest that prolonged GC-receptor stimulation during the early neonatal period can contribute to the development of individual differences in stress response and anxiety-related behavior later in life.
Also flagged:Cancertranscription factorTFbindingchromatinenvelope
Journal Article2011-08-19✓ 2 SnippetsWashington NL, Stinson EO, Perry MD, Ruzanov P, Contrino S, Smith R, Zha Z, Lyne R, Carr A, Lloyd P, Kephart E, McKay SJ, Micklem G, Stein LD, Lewis SE.
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Discussion)
…specifically query theDCCfor all ChIP-seq…
Discussion)
…role of aDCC…
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The model organism Encyclopedia of DNA Elements (modENCODE) project is a National Human Genome Research Institute (NHGRI) initiative designed to characterize the genomes of Drosophila melanogaster and Caenorhabditis elegans. A Data Coordination Center (DCC) was created to collect, store and catalog modENCODE data. An effective DCC must gather, organize and provide all primary, interpreted and analyzed data, and ensure the community is supplied with the knowledge of the experimental conditions, protocols and verification checks used to generate each primary data set. We present here the design principles of the modENCODE DCC, and describe the ramifications of collecting thorough and deep metadata for describing experiments, including the use of a wiki for capturing protocol and reagent information, and the BIR-TAB specification for linking biological samples to experimental results. modENCODE data can be found at http://www.modencode.org.
Also flagged:Nucleotide oligomerization domain-containing proteinsNod1Nod2pattern-recognition receptorsimmune responsesIgG1
Journal Article2011-08-19No SnippetsMagalhaes JG, Rubino SJ, Travassos LH, Le Bourhis L, Duan W, Sellge G, Geddes K, Reardon C, Lechmann M, Carneiro LA, Selvanantham T, Fritz JH, Taylor BC, Artis D, Mak TW, Comeau MR, Croft M, Girardin SE, Philpott DJ.
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Although a number of studies have examined the development of T-helper cell type 2 (Th2) immunity in different settings, the mechanisms underlying the initiation of this arm of adaptive immunity are not well understood. We exploited the fact that immunization with antigen plus either nucleotide-binding oligomerization domain-containing proteins 1 (Nod1) or 2 (Nod2) agonists drives Th2 induction to understand how these pattern-recognition receptors mediate the development of systemic Th2 immune responses. Here, we show in bone-marrow chimeric mice that Nod1 and Nod2 expression within the stromal compartment is necessary for priming of effector CD4(+) Th2 responses and specific IgG1 antibodies. In contrast, sensing of these ligands by dendritic cells was not sufficient to induce Th2 immunity, although these cells contribute to the response. Moreover, we determined that CD11c(+) cells were the critical antigen-presenting cells, whereas basophils and B cells did not affect the capacity of Nod ligands to induce CD4(+) Th2 effector function. Finally, we found that full Th2 induction upon Nod1 and Nod2 activation was dependent on both thymic stromal lymphopoietin production by the stromal cells and the up-regulation of the costimulatory molecule, OX40 ligand, on dendritic cells. This study provides in vivo evidence of how systemic Th2 immunity is induced in the context of Nod stimulation. Such understanding will influence the rational design of therapeutics that could reprogram the immune system during an active Th1-mediated disease, such as Crohn's disease.
Also flagged:degenerative diseaseBeta-CalciumPyrophosphate-calcium pyrophosphate
Journal Article2011-08-19No SnippetsLee JH, Chang BS, Jeung UO, Park KW, Kim MS, Lee CK.
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<h4>Background</h4>Porous β-calcium pyrophosphate (β-CPP) was developed to improve the fusion success of posterolateral lumbar fusion (PLF). The possibility of accomplishing PLF using a mixture of porous β-CPP and iliac bone was studied. This paper reports the radiologic results of PLF using the β-CPP plus autograft for lumbar degenerative disease as a bone graft extender.<h4>Methods</h4>A prospective, case-matched, radiographic study evaluating the results of short segment lumbar fusion using a β-CPP plus autograft was performed to compare the efficacy of β-CPP plus autograft with that of an autograft alone for short segment lumbar fusion. Thirty one consecutive patients (46 levels) underwent posterolateral fusion with pedicle screw fixation and additional posterior lumbar interbody fusion. In all patients, 3 mL of β-CPP plus 3 mL of autogenous bone graft was placed randomly in one side of a posterolateral gutter, and 6 mL of autogenous iliac bone graft was placed on the other. The fusion rates, volumes of fusion masses, and bone absorption percentage were evaluated postoperatively using simple radiographs and 3 dimensional computed tomography (3D-CT) scans.<h4>Results</h4>The control sides treated with an autograft showed significantly better Lenke scores than the study sides treated with β-CPP at 3 and 6 months postoperatively, but there was no difference between the two sides at 12 months. The fusion rates (confirmed by 3D-CT) were 87.0% in the β-CPP group and 89.1% in the autograft group, which were not significantly different. The fusion mass volumes and bone absorption percentage at 12 months postoperatively were 2.49 mL (58.4%) and 1.89 mL (69.5%) for the β-CPP and autograft groups, respectively, and mean fusion mass volume was significantly higher in the β-CPP group.<h4>Conclusions</h4>β-CPP combined with an autograft is as effective as autologous bone for grafting during instrumented posterolateral spinal fusion. These findings suggest that β-CPP bone chips can be used as a novel bone graft extender for short-segment posterolateral spinal fusion.
Also flagged:cDNAT7methcathinoneephedroneextrapyramidal syndromemanganese
Journal Article2011-08-19No SnippetsSikk K, Kõks S, Soomets U, Schalkwyk LC, Fernandes C, Haldre S, Aquilonius SM, Taba P.
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Methcathinone (ephedrone) is relatively easily accessible for abuse. Its users develop an extrapyramidal syndrome and it is not known if this is caused by methcathinone itself, by side-ingredients (manganese), or both. In the present study we aimed to clarify molecular mechanisms underlying this condition. We used microarrays to analyze whole-genome gene expression patterns of peripheral blood from 20 methcathinone users and 20 matched controls. Gene expression profile data were analyzed by Bayesian modeling and functional annotation. Of 28,869 genes on the microarrays, 326 showed statistically significant differential expression with FDR adjusted p-values below 0.05. Quantitative real-time PCR confirmed differential expression for the most of the genes selected for validation. Functional annotation and network analysis indicated activation of a gene network that included immunological disease, cellular movement, and cardiovascular disease functions (enrichment score 42). As HIV and HCV infections were confounding factors, we performed additional stratification of subjects. A similar functional activation of the "immunological disease" category was evident when we compared subjects according to injection status (past versus current users, balanced for HIV and HCV infection). However, this difference was not large therefore the major effect was related to the HIV status of the subjects. Mn-methcathinone abusers have blood RNA expression patterns that mostly reflect their HIV and HCV infections.
…Complement-dependent cytotoxicity (CDC) and Complement Receptor 3 (CR3; CD11b/CD18)-dependent cellular cytotoxicity (CR3-DCC) are important mechanisms through which tumor cells can be eliminated.…
Title)
…nt cellular cytotoxicity (CR3-DCC) are important mechanisms…
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The relative success of monoclonal antibodies in cancer immunotherapy and the vast manipulation potential of recombinant antibody technology have encouraged the development of novel antibody-based antitumor proteins. Many insightful reagents have been produced, mainly guided by studies on the mechanisms of action associated with complete and durable remissions, results from experimental animal models, and our current knowledge of the human immune system. Strikingly, only a small percent of these new reagents has demonstrated clinical value. Tumor burden, immune evasion, physiological resemblance, and cell plasticity are among the challenges that cancer therapy faces, and a number of antibody-based proteins are already available to deal with many of them. Some of these novel reagents have been shown to specifically increase apoptosis/cell death of tumor cells, recruit and activate immune effectors, and reveal synergistic effects not previously envisioned. In this review, we look into different approaches that have been followed during the past few years to produce these biologics and analyze their relative success, mainly in terms of their clinical performance. The use of antibody-based antitumor proteins, in combination with standard or novel therapies, is showing significant improvements in objective responses, suggesting that these reagents will become important components of the antineoplastic protocols of the future.
The novel reactivity of O-silylthionoesters with amine nucleophiles to generate oxoamides (rather than thioamides) is described. A straightforward first-generation trimethylsilylation protocol using bistrimethylsilylacetamide (BSA) combined with the unique reactivity of the O-silylthionoesters toward 1° and 2° amines to generate oxoamides provides the simplest means of activating a thiol acid for peptide bond formation at neutral pH. Excellent stereoretention is observed.
Also flagged:enhanced green fluorescent proteinphosphatase and tensin homologBRN2PLP1FABP7melanoma
Journal Article2011-08-18No SnippetsColombo S, Champeval D, Rambow F, Larue L.
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Studying the development of melanoblasts, precursors of melanocytes, is challenging owing to their scarcity and dispersion in the skin embryo. However, this is an important subject because diverse diseases are associated with defective melanoblast development. Consequently, characterizing patterns of expression in melanoblasts during normal development is an important issue. This requires isolating enough melanoblasts during embryonic development to obtain sufficient RNA to study their transcriptome. ZEG reporter mouse line crossed with Tyr::Cre mouse line was used to label melanoblasts by enhanced green fluorescent protein (EGFP) autofluorescence. We isolated melanoblasts by FACS from the skin of E14.5-E16.5 embryos, and obtained sufficient cells for large-scale transcriptomic analysis after RNA isolation and amplification. We confirmed our array-based data for various genes of interest by standard quantitative real-time RT-PCR. We demonstrated that phosphatase and tensin homolog was expressed in melanoblasts but BRN2 was not, although both are involved in melanomagenesis. We also revealed the potential contribution of genes not previously implicated in any function in melanocytes or even in neural crest derivatives. Finally, the Schwann cell markers, PLP1 and FABP7, were significantly expressed in melanoblasts, melanocytes, and melanoma. This study demonstrates the feasibility of the transcriptomic analysis of purified melanoblasts at different embryonic stages and reveals the involvement of previously unreported genes in melanoblast development.
Also flagged:axonscell bodiesnucleusinnervationsinnervationnetrin-1
Journal Article2011-08-18✓ 1 SnippetRatcliffe EM, Farrar NR, Fox EA.
In-Text Gene Mentions
Abstract)
…in colorectal cancer (DCC), extracellular matrix molecu…
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<h4>Background</h4>The vagus nerve is the major neural connection between the gastrointestinal tract and the central nervous system. During fetal development, axons from the cell bodies of the nodose ganglia and the dorsal motor nucleus grow into the gut to find their enteric targets, providing the vagal sensory and motor innervations respectively. Vagal sensory and motor axons innervate selective targets, suggesting a role for guidance cues in the establishment of the normal pattern of enteric vagal innervation.<h4>Purpose</h4>This review explores known molecular mechanisms that guide vagal innervation in the gastrointestinal tract. Guidance and growth factors, such as netrin-1 and its receptor, deleted in colorectal cancer, extracellular matrix molecules, such as laminin-111, and members of the neurotrophin family of molecules, such as brain-derived neurotrophic factor have been identified as mediating the guidance of vagal axons to the fetal mouse gut. In addition to increasing our understanding of the development of enteric innervation, studies of vagal development may also reveal clinically relevant insights into the underlying mechanisms of vago-vagal communication with the gastrointestinal tract.
Also flagged:KAP1Class I MAGE proteinsMAGE IcancerstumorKRAB domain zinc finger transcription factors
Journal Article2011-08-18✓ 1 SnippetXiao TZ, Bhatia N, Urrutia R, Lomberk GA, Simpson A, Longley BJ.
In-Text Gene Mentions
Title)
…MAGE I transcription factorsI transcription factors…
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Class I MAGE proteins (MAGE I) are normally expressed only in developing germ cells but are aberrantly expressed in many cancers. They have been shown to promote tumor survival, aggressive growth, and chemoresistance but the underlying mechanisms and MAGE I functions have not been fully elucidated. KRAB domain zinc finger transcription factors (KZNFs) are the largest group of vertebrate transcription factors and regulate neoplastic transformation, tumor suppression, cellular proliferation, and apoptosis. KZNFs bind the KAP1 protein and direct KAP1 to specific DNA sequences where it suppresses gene expression by inducing localized heterochromatin characterized by histone 3 lysine 9 trimethylation (H3me3K9). Discovery that MAGE I proteins also bind to KAP1 prompted us to investigate whether MAGE I can affect KZNF and KAP1 mediated gene regulation. We found that expression of MAGE I proteins, MAGE-A3 or MAGE-C2, relieved repression of a reporter gene by ZNF382, a KZNF with tumor suppressor activity. ChIP of MAGE I (-) HEK293T cells showed KAP1 and H3me3K9 are normally bound to the ID1 gene, a target of ZNF382, but that binding is greatly reduced in the presence of MAGE I proteins. MAGE I expression relieved KAP1 mediated ID1 repression, causing increased expression of ID1 mRNA and ID1 chromatin relaxation characterized by loss of H3me3K9. MAGE I binding to KAP1 also induced ZNF382 poly-ubiquitination and degradation, consistent with loss of ZNF382 leading to decreased KAP1 binding to ID1. In contrast, MAGE I expression caused increased KAP1 binding to Ki67, another KAP1 target gene, with increased H3me3K9 and decreased Ki67 mRNA expression. Since KZNFs are required to direct KAP1 to specific genes, these results show that MAGE I proteins can differentially regulate members of the KZNF family and KAP1 mediated gene repression.
Also flagged:neurodevelopmental disordersschizophreniaautismepilepsyINion channels
Journal Article2011-08-18✓ 5 SnippetsRossignol E.
In-Text Gene Mentions
S I O 001029)
…Sox6 is known to be important for proper cartilage formation [348–350], and one child with craniosynostosis (premature fusion of the cranial sutures) and facial dysmorphisms has been shown to carry a heterozygous mutation in SOX6 [198].…
Introduction)
…SRY-box 6 (Sox6), another transcription…
Introduction)
…Sox6is required for…
Introduction)
…Nkx2-1 −/− andSox6−/− null mutants…
Introduction)
…either Nkx2-1 orSox6in an MGE-specific…
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A dysfunction of cortical and limbic GABAergic circuits has been postulated to contribute to multiple neurodevelopmental disorders in humans, including schizophrenia, autism, and epilepsy. In the current paper, I summarize the characteristics that underlie the great diversity of cortical GABAergic interneurons and explore how the multiple roles of these cells in developing and mature circuits might contribute to the aforementioned disorders. Furthermore, I review the tightly controlled genetic cascades that determine the fate of cortical interneurons and summarize how the dysfunction of genes important for the generation, specification, maturation, and function of cortical interneurons might contribute to these disorders.
Also flagged:chromosomal regionsgene expressiontranscription factorschromosomeautosomesDNAJA2
Journal Article2011-08-17No SnippetsBecker J, Wendland JR, Haenisch B, Nöthen MM, Schumacher J.
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We aimed at identifying transcripts whose expression is regulated by a SNP-SNP interaction. Out of 47,294 expression phenotypes we used 3107 transcripts that survived an extensive quality control and 86,613 linkage disequilibrium-pruned SNP markers that have been genotyped in 210 individuals. For each transcript we defined cis-SNPs, tested them for epistasis with all trans-SNPs, and corrected all observed cis-trans-regulated expression effects for multiple testing. We determined that the expression of about 15% of all included transcripts is regulated by a significant two-locus interaction, which is more than expected (P = 2.86 × 10(-144)). Our findings suggest further that cis-markers with so called 'marginal effects' are more likely to be involved in two-locus gene regulation than expected (P = 8.27 × 10(-05)), although the majority of interacting cis-markers showed no one-locus regulation. Furthermore, we found evidence that gene-mediated trans-effects are not a major source of epistasis, as no enrichment of genes has been found in close vicinity of trans-SNPs. In addition, our data support the notion that neither chromosomal regions nor cellular processes are enriched in epistatic interactions. Finally, some of the cis-trans regulated genes have been found in genome-wide association studies, which might be interesting for follow-up studies of the corresponding disorders. In summary, our results provide novel insights into the complex genome-transcriptome regulation.
Also flagged:influenzabacterial infectionsimmune responsespathogenesisinfluenza infectionsinflammatory responses
Journal Article2011-08-17No SnippetsHoward WA, Peiris M, Hayden FG.
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The clinical course of influenza and the extent of lung injury are determined by both viral and host factors, as well as sometimes secondary bacterial infections and exacerbations of underlying conditions. The balance between viral replication and the host immune responses is central to disease pathogenesis, and the extent of lung injury in severe influenza infections may be due in part to overly exuberant or dysregulated innate inflammatory responses or sometimes deficient responses. Acute respiratory distress syndrome (ARDS) is the principal cause of respiratory failure associated with severe influenza. ARDS can be triggered by both direct lung insults (e.g. respiratory pathogens) and systemic insults (e.g. sepsis), and the lung damage is exacerbated by the inflammatory response associated with either infectious or non-infectious insults. This workshop aimed to review the current understanding of lung injury in acute influenza and describe cellular and molecular mechanisms of lung injury that are common to influenza and infections by other respiratory pathogens. In addition, therapeutic agents that target host response proteins and pathways were identified and investigational agents in development reviewed. A logical strategy would be to combine antiviral treatment with drugs that modify excessive host responses or supplement deficient ones. However, a better understanding of common cell signalling pathways associated with acute lung injury caused by influenza and other pathogens is necessary to understand immunopathologic causes of lung injury. This will help determine which immunomodulatory interventions might be useful, and to predict the appropriate timing and consequences of their use.
Also flagged:toxin Aglucosylationthreoninecytoskeletondeathglucosyltransferase
Journal Article2011-08-17No SnippetsJochim N, Gerhard R, Just I, Pich A.
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<h4>Background</h4>The anaerobe Clostridium difficile produces two major virulence factors toxin A and B that inactivate Rho proteins by glucosylation of a pivotal threonine residue. Purified toxins induce reorganization of the cytoskeleton and cell death in colonic cells. Whether all toxin effects on target cells depend on catalytic glucosyltransferase activity is unclear at present. Thus, we conducted a proteome approach to compare the protein profile of target cells treated either with wild type toxin A (rTcdA wt) or with a catalytically inactive mutant toxin A (mutant rTcdA). Relative protein quantification was feasible using isotope-coded protein labeling techniques (ICPL) and mass spectrometry (LC-MALDI).<h4>Results</h4>Altogether we found a significant differential expression of thirty proteins after treatment with rTcdA wt or mutant rTcdA. Mutant rTcdA caused up-regulation of seven proteins and sixteen proteins were responsive to rTcdA wt after 5 h. Long-term effect of rTcdA wt on protein expression was the down-regulation of eleven proteins. Up- or down-regulation of several proteins was verified by western blot analysis confirming the MS results.<h4>Conclusion</h4>Our results indicate incubation time-dependent effects of the clostridial glucosylating toxin A on colonic cells. The rTcdA wt impact more cellular functions than actin cytoskeleton reorganization and apoptosis. Furthermore, these data give insight into glucosyltransferase independent effects of clostridial glucosylating toxins on target cells after short incubation time. Additionally, our data reveal pro-inflammatory and proliferative effects of mutant rTcdA after short-term incubation.
Also flagged:netrin-1Src kinaseRhoARho kinaseDeleted in Colorectal Canceraxons
Journal Article2011-08-17✓ 5 SnippetsAntoine-Bertrand J, Ghogha A, Luangrath V, Bedford FK, Lamarche-Vane N.
In-Text Gene Mentions
Results)
…The impact of ERM activity in DCC-mediated neurite outgrowth was then assessed by coexpressing DCC and ezrin protein mutants in neuroblastoma cells.…
Introduction)
…Src kinase activity and netrin-1–dependent phosphorylation of the C-terminal tyrosine residue 1418 (Y1418) of DCC are essential to netrin-1–mediated axon outgrowth and attraction (Li et al., 2004;Meriane et al., 2004;Ren et al., 2008).…
Introduction)
…Netrin-1 induces the phosphorylation of DCC on tyrosine, serine, and threonine residues (Meriane et al., 2004).…
Introduction)
…Finally, impairing ERM activity inhibits DCC-mediated neurite outgrowth in mouse N1E-115 neuroblastoma cells, and loss of ezrin expression blocks netrin-1–induced axon outgrowth in primary cortical neurons.…
Methods)
…Neurons were treated for the indicated times with the following reagents: purified myc-netrin-1 (500 ng/ml), glutamate (50 μM), generously provided by D. Bowie (McGill University, Montreal, Canada), function-blocking anti-DCC (AF5) antibody (5 μg/ml for 24 h; Calbiochem, La Jolla, CA), ImmunoPure mouse IgG (5 μg/ml for 24 h; Pierce, Thermo Fisher Scientific, Rockford, IL), PP2 (10 μM overnight; Calbiochem), toxin B (1 ng/ml for 24 h) previously described (Li et al., 2002), C3 transferase (1 μg/ml for 6 h; Cytoskeleton, Denver, CO), NSC23766 (100 μM for 2 h; Calbiochem), Y27632 (20 μM for 6 h; Calbiochem), DMSO (Thermo Fisher Scientific), and glycerol (Thermo Fisher Scientific).…
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The receptor Deleted in Colorectal Cancer (DCC) mediates the attractive response of axons to the guidance cue netrin-1 during development. On netrin-1 stimulation, DCC is phosphorylated and induces the assembly of signaling complexes within the growth cone, leading to activation of cytoskeleton regulators, namely the GTPases Rac1 and Cdc42. The molecular mechanisms that link netrin-1/DCC to the actin machinery remain unclear. In this study we seek to demonstrate that the actin-binding proteins ezrin-radixin-moesin (ERM) are effectors of netrin-1/DCC signaling in embryonic cortical neurons. We show that ezrin associates with DCC in a netrin-1-dependent manner. We demonstrate that netrin-1/DCC induces ERM phosphorylation and activation and that the phosphorylation of DCC is required in that context. Moreover, Src kinases and RhoA/Rho kinase activities mediate netrin-1-induced ERM phosphorylation in neurons. We also observed that phosphorylated ERM proteins accumulate in growth cone filopodia, where they colocalize with DCC upon netrin-1 stimulation. Finally, we show that loss of ezrin expression in cortical neurons significantly decreases axon outgrowth induced by netrin-1. Together, our findings demonstrate that netrin-1 induces the formation of an activated ERM/DCC complex in growth cone filopodia, which is required for netrin-1-dependent cortical axon outgrowth.
Endoplasmic reticulum (ER) stress triggers a homeostatic cellular response in mammalian cells to ensure efficient folding, sorting, and processing of client proteins. In lytic-permissive lymphoblastoid cell lines (LCLs), pulse exposure to the chemical ER-stress inducer thapsigargin (TG) followed by recovery resulted in the activation of the EBV immediate-early (BRLF1, BZLF1), early (BMRF1), and late (gp350) genes, gp350 surface expression, and virus release. The protein phosphatase 1 a (PP1a)-specific phosphatase inhibitor Salubrinal (SAL) synergized with TG to induce EBV lytic genes; however, TG treatment alone was sufficient to activate EBV lytic replication. SAL showed ER-stress-dependent and -independent antiviral effects, preventing virus release in human LCLs and abrogating gp350 expression in 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated B95-8 cells. TG resulted in sustained BCL6 but not BLIMP1 or CD138 expression, which is consistent with maintenance of a germinal center B-cell, rather than plasma-cell, phenotype. Microarray analysis identified candidate genes governing lytic replication in LCLs undergoing ER stress.
Also flagged:chrysoidineantibodieshaptenstetramethylbenzidinealbumin
Journal Article2011-08-17No SnippetsLei H, Liu J, Song L, Shen Y, Haughey SA, Guo H, Yang J, Xu Z, Jiang Y, Sun Y.
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A highly specific and sensitive indirect competitive enzyme-linked immunosorbent assay (icELISA)was developed for the first time for the detection of chrysoidine, a dye banned in soybean milk film. Two haptens with different spacer arms were synthesized to produce antibodies. Both homologous and heterologous immunoassay formats were compared to enhance the icELISA sensitivity. The heterologous icELISA exhibited better performance, with an IC(50) (50% inhibitory concentration) of 0.33 ng/mL, a limit of detection (LOD, 10% inhibitory concentration) of 0.04 ng/mL, and a limit of quantitation (LOQ, 20%-80% inhibitory concentration) from 0.09 to 4.9 ng/mL. The developed icELISA was high sensitive and specific, and was applied to determine chrysoidine in fortified soybean milk film samples. The results were in good agreement with that obtained by high-performance liquid chromatography (HPLC) analyses.
Also flagged:Calciumcolorectal cancertumorpolymerasegene expressionWnt
Journal Article2011-08-17✓ 5 SnippetsWang JL, Lin YW, Chen HM, Kong X, Xiong H, Shen N, Hong J, Fang JY.
In-Text Gene Mentions
Abstract)
…Microarray gene expression analysis showed that S100a9, Defa20, Mmp10, Mmp7, Ptgs2, and Ang2 were among the most downregulated genes, whereas Per3, Tef, Rnf152, and Prdx6 were significantly upregulated in the DMH + Calcium group compared with the DMH group.…
Abstract)
…Rnf152 , andPrdx6were significantly upregulated…
Methods)
…Rnf152 , andPrdx6.…
Results)
…Rnf152 , andPrdx6, the results…
Discussion)
…e.g., Rnf152 andPrdx6.…
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<h4>Background and aim</h4>Calcium has been proposed as a mediator of the chemoprevention of colorectal cancer (CRC), but the comprehensive mechanism underlying this preventive effect is not yet clear. Hence, we conducted this study to evaluate the possible roles and mechanisms of calcium-mediated prevention of CRC induced by 1,2-dimethylhydrazine (DMH) in mice.<h4>Methods</h4>For gene expression analysis, 6 non-tumor colorectal tissues of mice from the DMH + Calcium group and 3 samples each from the DMH and control groups were hybridized on a 4×44 K Agilent whole genome oligo microarray, and selected genes were validated by real-time polymerase chain reaction (PCR). Functional analysis of the microarray data was performed using KEGG and Gene Ontology (GO) analyses. Hub genes were identified using Pathway Studio software.<h4>Results</h4>The tumor incidence rates in the DMH and DMH + Calcium groups were 90% and 40%, respectively. Microarray gene expression analysis showed that S100a9, Defa20, Mmp10, Mmp7, Ptgs2, and Ang2 were among the most downregulated genes, whereas Per3, Tef, Rnf152, and Prdx6 were significantly upregulated in the DMH + Calcium group compared with the DMH group. Functional analysis showed that the Wnt, cell cycle, and arachidonic acid pathways were significantly downregulated in the DMH + Calcium group, and that the GO terms related to cell differentiation, cell cycle, proliferation, cell death, adhesion, and cell migration were significantly affected. Forkhead box M1 (FoxM1) and nuclear factor kappa-B (NF-κB) were considered as potent hub genes.<h4>Conclusion</h4>In the DMH-induced CRC mouse model, comprehensive mechanisms were involved with complex gene expression alterations encompassing many altered pathways and GO terms. However, how calcium regulates these events remains to be studied.
Also flagged:type 2 diabetesprostate cancercholesterolmultiple sclerosisdiabeteshypertension
Journal Article2011-08-17No SnippetsTung JY, Do CB, Hinds DA, Kiefer AK, Macpherson JM, Chowdry AB, Francke U, Naughton BT, Mountain JL, Wojcicki A, Eriksson N.
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While the cost and speed of generating genomic data have come down dramatically in recent years, the slow pace of collecting medical data for large cohorts continues to hamper genetic research. Here we evaluate a novel online framework for obtaining large amounts of medical information from a recontactable cohort by assessing our ability to replicate genetic associations using these data. Using web-based questionnaires, we gathered self-reported data on 50 medical phenotypes from a generally unselected cohort of over 20,000 genotyped individuals. Of a list of genetic associations curated by NHGRI, we successfully replicated about 75% of the associations that we expected to (based on the number of cases in our cohort and reported odds ratios, and excluding a set of associations with contradictory published evidence). Altogether we replicated over 180 previously reported associations, including many for type 2 diabetes, prostate cancer, cholesterol levels, and multiple sclerosis. We found significant variation across categories of conditions in the percentage of expected associations that we were able to replicate, which may reflect systematic inflation of the effects in some initial reports, or differences across diseases in the likelihood of misdiagnosis or misreport. We also demonstrated that we could improve replication success by taking advantage of our recontactable cohort, offering more in-depth questions to refine self-reported diagnoses. Our data suggest that online collection of self-reported data from a recontactable cohort may be a viable method for both broad and deep phenotyping in large populations.
TREK1 is a widely expressed background potassium channel. Similar to mice treated with selective serotonin reuptake inhibitors (SSRIs), TREK1 knockout mice are resistant to depression-like behavior and have elevated serotonin levels leading to speculation that TREK1 inhibition may contribute to the therapeutic effects of SSRIs. This study examined how chronic fluoxetine administration and a common functional polymorphism in the serotonin-transporter-linked promoter region (5-HTTLPR) influence cortical TREK1 expression in 24 rhesus monkeys. The short rh5-HTTLPR allele as well as female gender were associated with reduced cortical TREK1 protein expression but chronic SSRI administration had no effect. These results suggest that serotonin may influence TREK1, but that chronic SSRI treatment does not result in long lasting changes in cortical TREK1 protein expression. TREK1 gender differences may be related to gender differences in serotonin and require further research.
Also flagged:hereditary haemochromatosisHHironhyperferritinemianucleotidetyrosine
Journal Article2011-08-17✓ 5 SnippetsTakano A, Niimi H, Atarashi Y, Sawasaki T, Terasaki T, Nakabayashi T, Kitajima I, Tobe K, Takahara T.
In-Text Gene Mentions
Abstract)
…This homozygous Y231del mutation was recently found in the Huh-7 hepatoma cell line and was shown to prevent the translocation of HFE to the cell surface.…
Title)
…A novel Y231del mutation of HFE in hereditary haemochromatosis provides in vivo evidence that the Huh-7 is a human haemochromatotic cell line.…
Abstract)
…691_693del) responsible for the loss of a tyrosine at position 231 (p. Y231del) of the HFE protein.…
Hereditary haemochromatosis (HH), which is mainly associated with a C282Y polymorphism in HFE, is common among Caucasians of north European descent, but is very rare among Asians. Herein, we report a 43-year-old Japanese man who was diagnosed as having HH. A laboratory examination revealed an elevated serum iron level (280 μg/dl), hyperferritinemia (1698 ng/ml) and a low serum level of hepcidin-25 (4.0 ng/ml). Abdominal magnetic resonance imaging revealed findings suggestive of iron accumulation in the liver and pancreas. HFE gene sequencing in the patient revealed a novel homozygous TAC nucleotide deletion (c. 691_693del) responsible for the loss of a tyrosine at position 231 (p. Y231del) of the HFE protein. This homozygous Y231del mutation was recently found in the Huh-7 hepatoma cell line and was shown to prevent the translocation of HFE to the cell surface. This clinical case provides in vivo evidence suggesting that Huh-7 is undoubtedly a human haemochromatotic cell line and, as such, is a valuable tool for investigating the pathogenesis of HFE-related HH in humans.
Also flagged:CUG-BPCUG-BP, Elav-likenucleuscytoplasmpathogenesisElav
Journal Article2011-08-17No SnippetsDasgupta T, Ladd AN.
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RNA processing is important for generating protein diversity and modulating levels of protein expression. The CUG-BP, Elav-like family (CELF) of RNA-binding proteins regulate several steps of RNA processing in the nucleus and cytoplasm, including pre-mRNA alternative splicing, C to U RNA editing, deadenylation, mRNA decay, and translation. In vivo, CELF proteins have been shown to play roles in gametogenesis and early embryonic development, heart and skeletal muscle function, and neurosynaptic transmission. Dysregulation of CELF-mediated programs has been implicated in the pathogenesis of human diseases affecting the heart, skeletal muscles, and nervous system.
Also flagged:serotonin transporteranxiety disorders55-HTTLPRvisionproteinase K
Journal Article2011-08-16No SnippetsFox E, Zougkou K, Ridgewell A, Garner K.
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<h4>Background</h4>Attention bias modification (ABM) procedures have been shown to modify biased attention with important implications for emotional vulnerability and resilience. The use of ABM to reduce potentially toxic biases, for instance, is a newly emerging therapy for anxiety disorders. A separate line of gene-by-environment interaction research proposes that many so-called vulnerability genes or risk alleles are better seen as plasticity genes, as they seem to make individuals more susceptible to environmental influences for better and for worse.<h4>Methods</h4>A standard ABM procedure was used with a sample of 116 healthy adults. Participants were randomly assigned to one of two training groups. One received an ABM procedure designed to induce a bias in attention toward negative material, while the other was trained toward positive pictures. Individuals with low- and high-expressing forms of the serotonin transporter gene (5-HTTLPR) were compared.<h4>Results</h4>Those with a low-expression form (S/S, S/Lg, or Lg/Lg) of the 5-HTTLPR gene developed stronger biases for both negative and positive affective pictures relative to those with the high-expression (La/La) form of the gene.<h4>Conclusions</h4>Here, we report the first evidence that allelic variation in the promotor region of the 5-HTTLPR gene predicts different degrees of sensitivity to ABM. These results suggest a potential cognitive mechanism for the gene-by-environment interactions that have been found in relation to the serotonin transporter gene. Variation on this genotype may therefore determine who will benefit most (and least) from therapeutic interventions, adversity, and supportive environments.
Journal Article2011-08-16✓ 2 SnippetsSchwarz D, Diesterbeck US, König S, Brügemann K, Schlez K, Zschöck M, Wolter W, Czerny CP.
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Abstract)
…value 47%), whereasDCCpatterns of milk…
Abstract)
…processes based onDCC.…
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Somatic cell count (SCC) is generally regarded as an indicator of udder health. A cut-off value of 100×10(3) cells/ml is currently used in Germany to differentiate between normal and abnormal secretion of quarters. In addition to SCC, differential cell counts (DCC) can be applied for a more detailed analysis of the udder health status. The aim of this study was to differentiate somatic cells in foremilk samples of udder quarters classified as normal secreting by SCC <100×10(3) cells/ml. Twenty cows were selected and 72 normal secreting udder quarters were compared with a control group of six diseased quarters (SCC >100×10(3) cells/ml). In two severely diseased quarters of the control group (SCC of 967×10(3) cells/ml and 1824×10(3) cells/ml) Escherichia coli and Staphylococcus aureus were detected. DCC patterns of milk samples (n = 25) with very low SCC values of ≤6·25×10(3)cells/ml revealed high lymphocyte proportions of up to 92%. Milk cell populations in samples (n = 41) with SCC values of (>6·25 to ≤25)×10(3) cells/ml were also dominated by lymphocytes (mean value 47%), whereas DCC patterns of milk from udder quarters (n = 6) with SCC values (>25 to ≤100)×10(3)cells/ml changed. While in samples (n = 3) with SCC values of (27-33)×10(3) cells/ml macrophages were predominant (35-40%), three milk samples with (43-45)×10(3) cells/ml indicated already inflammatory reactions based on the predominance of polymorphonuclear leucocytes (PMN) (54-63%). In milk samples of diseased quarters PMN were categorically found as dominant cell population with proportions of ≥65%. Macrophages were the second predominant cell population in almost all samples tested in relationship to lymphocytes and PMN. To our knowledge, this is the first study evaluating cell populations in low SCC milk in detail. Udder quarters classified as normal secreting by SCC <100×10(3) cells/ml revealed already inflammatory processes based on DCC.
Also flagged:5-hydroxytryptamine transporter5-HT₄ receptor5-HT transporterpsychiatric disorder5-HT receptorbinding
Journal Article2011-08-16✓ 5 SnippetsJennings KA, Licht CL, Bruce A, Lesch KP, Knudsen GM, Sharp T.
In-Text Gene Mentions
Abstract)
…Together, these findings suggest that variation in 5-HTT expression causes adaptive changes in 5-HT₄ receptor levels which are directly linked to alterations in 5-HT availability.…
Genetic variation in 5-HT transporter (5-HTT) expression is a key risk factor for psychiatric disorder and has been linked to changes in the expression of certain 5-HT receptor subtypes. This study investigated the effect of variation in 5-HTT expression on 5-HT₄ receptor levels in both 5-HTT knockout (KO) and overexpressing (OE) mice using autoradiography with the selective 5-HT₄ receptor radioligand, [³H]SB207145. Compared to wild-type (5-HTT⁺/⁺) controls, homozygous 5-HTT KO mice (5-HTT⁻/⁻) had reduced 5-HT₄ receptor binding site density in all brain regions examined (35-65% of 5-HTT⁺/⁺). In contrast, the density of 5-HT₄ receptor binding sites was not significantly different between heterozygous 5-HTT KO mice (5-HTT⁻/⁺) and 5-HTT⁺/⁺ mice. The 5-HT synthesis inhibitor p-chlorophenylalanine (250 mg/kg twice daily for 3 d) abolished the difference in 5-HT₄ binding between 5-HTT⁻/⁻ and 5-HTT⁺/⁺ mice in all brain regions. Compared to wild-type (WT) littermate controls, 5-HTT OE mice had increased 5-HT₄ binding density across all brain regions, except amygdala (118-164% of WT) and this difference between genotypes was reduced by the 5-HTT inhibitor, fluoxetine (20 mg/kg twice daily, 3 d). Together, these findings suggest that variation in 5-HTT expression causes adaptive changes in 5-HT₄ receptor levels which are directly linked to alterations in 5-HT availability.
Also flagged:MAPKRNA-binding proteinRNA-binding proteinsRBPoxygenELAVL1
Journal Article2011-08-16✓ 1 SnippetCalder MD, Watson PH, Watson AJ.
In-Text Gene Mentions
Abstract)
…STAU1, ELAVL1, KHSRP and…
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During oogenesis, mammalian oocytes accumulate maternal mRNAs that support the embryo until embryonic genome activation. RNA-binding proteins (RBP) may regulate the stability and turnover of maternal and embryonic mRNAs. We hypothesised that varying embryo culture conditions, such as culture medium, oxygen tension and MAPK inhibition, affects regulation of RBPs and their targets during preimplantation development. STAU1, ELAVL1, KHSRP and ZFP36 proteins and mRNAs were detected throughout mouse preimplantation development, whereas Elavl2 mRNA decreased after the two-cell stage. Potential target mRNAs of RBP regulation, Gclc, Slc2a1 and Slc7a1 were detected during mouse preimplantation development. Gclc mRNA was significantly elevated in embryos cultured in Whitten's medium compared with embryos cultured in KSOMaa, and Gclc mRNA was elevated under high-oxygen conditions. Inhibition of the p38 MAPK pathway reduced Slc7a1 mRNA expression while inhibition of ERK increased Slc2a1 mRNA expression. The half-lives of the potential RBP mRNA targets are not regulated in parallel; Slc2a1 mRNA displayed the longest half-life. Our results indicate that mRNAs and proteins encoding five RBPs are present during preimplantation development and more importantly, demonstrate that expression of RBP target mRNAs are regulated by culture medium, gas atmosphere and MAPK pathways.
…In male somatic tissues, the canonical dosage compensation complex (DCC), which comprises at least five proteins (MSL1, MSL2, MSL3, MLE, and MOF) and two RNAs (roX1 and roX2), is targeted to degenerate high-affinity binding sequences enriched on the X chromosome and spreads to transcriptionally active genes where it facilitates hyper-transcription by directing acetylation of histone H4 on lysine 16 (H4Ac16) and enhancing the elongation of RNA polymerase II [10],[16],[17].…
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…Impairment of theDCCin these experiments…
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…Loss ofDCC-dependent dosage compensation…
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…the somatic andDCC-expressing [18] cells of…
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…somatic, express theDCC[18] , and…
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The evolution of heteromorphic sex chromosomes (e.g., XY in males or ZW in females) has repeatedly elicited the evolution of two kinds of chromosome-specific regulation: dosage compensation--the equalization of X chromosome gene expression in males and females--and meiotic sex chromosome inactivation (MSCI)--the transcriptional silencing and heterochromatinization of the X during meiosis in the male (or Z in the female) germline. How the X chromosome is regulated in the Drosophila melanogaster male germline is unclear. Here we report three new findings concerning gene expression from the X in Drosophila testes. First, X chromosome-wide dosage compensation appears to be absent from most of the Drosophila male germline. Second, microarray analysis provides no evidence for X chromosome-specific inactivation during meiosis. Third, we confirm the previous discovery that the expression of transgene reporters driven by autosomal spermatogenesis-specific promoters is strongly reduced when inserted on the X chromosome versus the autosomes; but we show that this chromosomal difference in expression is established in premeiotic cells and persists in meiotic cells. The magnitude of the X-autosome difference in transgene expression cannot be explained by the absence of dosage compensation, suggesting that a previously unrecognized mechanism limits expression from the X during spermatogenesis in Drosophila. These findings help to resolve several previously conflicting reports and have implications for patterns of genome evolution and speciation in Drosophila.
Also flagged:chromosomegene expressiongenetic diseaseschromosomesgelatinCollagenase
Journal Article2011-08-16No SnippetsPeterson SE, Westra JW, Rehen SK, Young H, Bushman DM, Paczkowski CM, Yung YC, Lynch CL, Tran HT, Nickey KS, Wang YC, Laurent LC, Loring JF, Carpenter MK, Chun J.
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Human pluripotent stem cell (hPSC) lines have been considered to be homogeneously euploid. Here we report that normal hPSC--including induced pluripotent--lines are karyotypic mosaics of euploid cells intermixed with many cells showing non-clonal aneuploidies as identified by chromosome counting, spectral karyotyping (SKY) and fluorescent in situ hybridization (FISH) of interphase/non-mitotic cells. This mosaic aneuploidy resembles that observed in progenitor cells of the developing brain and preimplantation embryos, suggesting that it is a normal, rather than pathological, feature of stem cell lines. The karyotypic heterogeneity generated by mosaic aneuploidy may contribute to the reported functional and phenotypic heterogeneity of hPSCs lines, as well as their therapeutic efficacy and safety following transplantation.
Huntington's disease (HD) is a genetic neurodegenerative disorder that is characterized by the progressive onset of cognitive, psychiatric, and motor symptoms. In parallel, the neuropathology of HD is characterized by progressive loss of projection neurons in cortex and striatum; striatal cholinergic interneurons are relatively spared. Nonetheless, there is evidence that striatal acetylcholine (ACh) function is altered in HD. The present study is the first to examine striatal ACh function in awake, behaving animals, using the R6/2 mouse model of HD, which is transgenic for exon 1 of the mutant huntingtin gene. Physiological levels of extracellular striatal ACh were monitored in R6/2 mice and wild type controls using in vivo microdialysis. Results indicate that spontaneous ACh release is reduced in R6/2 mice relative to controls. Intrastriatal application of the GABA(A) antagonist bicuculline methiodide (10.0 μM) significantly elevated ACh levels in both R6/2 mice and wild type controls, while overall ACh levels were reduced in the R6/2 mice compared to the wild type group. In contrast, systemic administration of the D(1) dopamine receptor partial agonist, SKF-38393 (10.0mg/kg, IP), elevated ACh levels in control animals, but not R6/2 mice. Taken together, the present results suggest that GABA-mediated inhibition of striatal ACh release is intact in R6/2 mice, further demonstrating that cholinergic interneurons are capable of increased ACh release, whereas D(1) receptor-dependent activation of excitatory inputs to striatal cholinergic interneurons is dysfunctional in R6/2 mice. Reduced levels of extracellular striatal ACh in HD may reflect abnormalities in the excitatory innervation of cholinergic interneurons, which may have implications ACh-dependent processes that are altered in HD, including corticostriatal plasticity.
Uncontrollability of major life events has been proposed to be central to depression onset and maintenance. The learned helplessness (LH) effect describes a deficit in terminating controllable aversive stimuli in individuals that experienced aversive stimuli as uncontrollable relative to individuals that experienced the same stimuli as controllable. The LH effect translates across species and therefore can provide an objective-valid readout in animal models of depression. Paradigms for a robust LH effect are established and currently applied in rat but there are few reports of prior and current study of the LH effect in mouse. This includes the C57BL/6 mouse, typically the strain of choice for application of molecular-genetic tools in pre-clinical depression research. The aims of this study were to develop a robust paradigm for the LH effect in BL/6 mice, provide evidence for underlying psychological processes, and study the effect of a depression-relevant genotype on the LH effect. The apparatus used for in/escapable electro-shock exposure and escape test was a two-way shuttle arena with continuous automated measurement of locomotion, compartment transfers, e-shock escapes, vertical activity and freezing. Brother-pairs of BL/6 mice were allocated to either escapable e-shocks (ES) or inescapable e-shocks (IS), with escape latencies of the ES brother used as e-shock durations for the IS brother. The standard two-way shuttle paradigm was modified: the central gate was replaced by a raised divider and e-shock escape required transfer to the distal part of the safe compartment. These refinements yielded reduced superstitious, pre-adaptive e-shock transfers in IS mice and thereby increased the LH effect. To obtain a robust LH effect in all brother pairs, pre-screening for minor between-brother ES differences was necessary and did not confound the LH effect. IS mice developed reduced motor responses to e-shock, consistent with a motivational deficit, and absence of a learning curve for escapes at escape test, consistent with a cognitive deficit. When a tone CS was used to predict e-shock, IS mice exhibited increased reactivity to the CS, consistent with hyper-emotionality. There was no ES-IS difference in pain sensitivity. Mice heterozygous knockout for the 5-HTT gene exhibited an increased LH effect relative to wildtype mice. This mouse model will allow for the detailed molecular study of the aetiology, psychology, neurobiology and neuropharmacology of uncontrollability of aversive stimuli, a potential major aetiological factor and state marker in depression. This article is part of a Special Issue entitled 'Anxiety and Depression'.
Also flagged:Hereditary hemochromatosisironhematopoiesispeptide hormoneHepcidiniron transport protein
Journal Article2011-08-16✓ 3 SnippetsChen J, Enns CA.
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…HFE…
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…hemochromatosis…
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…HFE-deficiency…
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<h4>Background</h4>Multicellular organisms regulate the uptake of calories, trace elements, and other nutrients by complex feedback mechanisms. In the case of iron, the body senses internal iron stores, iron requirements for hematopoiesis, and inflammatory status, and regulates iron uptake by modulating the uptake of dietary iron from the intestine. Both the liver and the intestine participate in the coordination of iron uptake and distribution in the body. The liver senses inflammatory signals and iron status of the organism and secretes a peptide hormone, hepcidin. Under high iron or inflammatory conditions hepcidin levels increase. Hepcidin binds to the iron transport protein, ferroportin (FPN), promoting FPN internalization and degradation. Decreased FPN levels reduce iron efflux out of intestinal epithelial cells and macrophages into the circulation. Derangements in iron metabolism result in either the abnormal accumulation of iron in the body, or in anemias. The identification of the mutations that cause the iron overload disease, hereditary hemochromatosis (HH), or iron-refractory iron-deficiency anemia has revealed many of the proteins used to regulate iron uptake.<h4>Scope of the review</h4>In this review we discuss recent data concerning the regulation of iron homeostasis in the body by the liver and how transferrin receptor 2 (TfR2) affects this process.<h4>Major conclusions</h4>TfR2 plays a key role in regulating iron homeostasis in the body.<h4>General significance</h4>The regulation of iron homeostasis is important. One third of the people in the world are anemic. HH is the most common inherited disease in people of Northern European origin and can lead to severe health complications if left untreated. This article is part of a Special Issue entitled Transferrins: Molecular mechanisms of iron transport and disorders.
Also flagged:ironpeptide hormonemetabolismantibodiessulfateHepcidin
Journal Article2011-08-16✓ 2 SnippetsHwang SI, Lee YY, Park JO, Norton HJ, Clemens E, Schrum LW, Bonkovsky HL.
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…HFE…
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…hemochromatosis…
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<h4>Background</h4>The measurement of serum hepcidin, a peptide hormone that regulates iron metabolism, is clinically important to the understanding of iron homeostasis in health and disease. To date, the quantification of serum hepcidin levels by conventional immunological detection methods has proven problematic due to challenges in obtaining high quality antibodies which demonstrate good reproducibility. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) has been employed recently for more sensitive quantification of hepcidin; however, this method has high background levels and therefore less than optimal specificity.<h4>Methods</h4>In order to increase the specificity of the mass spectrometry based assay, we developed a robust, ultra-performance liquid-chromatography-tandem mass spectrometry (UPLC-MS/MS) protocol using multiple selected reaction monitoring (mSRM) for quantification of hepcidin levels in urine and serum of human subjects. With this assay, we assessed levels of hepcidin before and for up to 8 h after oral ingestion of ferrous sulfate in ten adult human subjects without known disease.<h4>Results</h4>The linear response of hepcidin quantitation on each instrument was measured, and the correlation coefficients of these calibrations were r(2)=0.9512±0.0202 (n=5) for urine and r(2)=0.9709±0.0291 (n=5) for serum [r(2)=mean±SD]. Compared to baseline, the levels of urinary hepcidin between 2-4 h and 4-8 h of both women and men showed significant increases with p<0.05 and p<0.001, respectively. The levels of serum hepcidin between 4 h and 8 h in both women and men showed significant increases, compared with baseline values, with both p<0.01. Interestingly, we also observed some degree of oscillation of levels, occurring at later time points.<h4>Conclusions</h4>We have developed and validated a new method for measuring hepcidin concentrations in human serum and urine and used it to demonstrate early increases with iron supplement in both urinary and serum levels of hepcidin, which return to baseline levels, except in urine samples from men.
Tissue inhibitor of metalloproteinases-2 (TIMP-2) inhibits angiogenesis by several mechanisms involving either MMP inhibition or direct endothelial cell binding. The primary aim of this study was to identify the TIMP-2 region involved in binding to the previously identified receptor integrin α3β1, and to determine whether synthetic peptides derived from this region retained angio-inhibitory and tumor suppressor activity. We demonstrated that the N-terminal domain of TIMP-2 (N-TIMP-2) binds to α3β1 and inhibits vascular endothelial growth factor-stimulated endothelial cell growth in vitro, suggesting that both the α3β1-binding domain and the growth suppressor activity of TIMP-2 localize to the N-terminal domain. Using a peptide array approach we identify a 24 amino acid region of TIMP-2 primary sequence, consisting of residues Ile43-Ala66, which shows α3β1-binding activity. Subsequently we demonstrate that synthetic peptides from this region compete for TIMP-2 binding to α3β1 and suppress endothelial growth in vitro. We define a minimal peptide sequence (peptide 8-9) that possesses both angio-inhibitory and, using a murine xenograft model of Kaposi's sarcoma, anti-tumorigenic activity in vivo. Thus, both the α3β1-binding and the angio-inhibitory activities co-localize to a solvent exposed, flexible region in the TIMP-2 primary sequence that is unique in amino acid sequence compared with other members of the TIMP family. Furthermore, comparison of the TIMP-2 and TIMP-1 protein 3-D structures in this region also identified unique structural differences. Our findings demonstrate that the integrin binding, tumor growth suppressor and in vivo angio-inhibitory activities of TIMP-2 are intimately associated within a unique sequence/structural loop (B-C loop).
Also flagged:Cell surfaceviral oncoproteinTaxcostimulatory receptorstumor necrosis factorcytokine receptors
Journal Article2011-08-16No SnippetsKress AK, Grassmann R, Fleckenstein B.
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The phenotype of HTLV-1-transformed CD4(+) T lymphocytes largely depends on defined viral effector molecules such as the viral oncoprotein Tax. In this review, we exemplify the expression pattern of characteristic lineage markers, costimulatory receptors and ligands of the tumor necrosis factor superfamily, cytokine receptors, and adhesion molecules on HTLV-1-transformed cells. These molecules may provide survival signals for the transformed cells. Expression of characteristic surface markers might therefore contribute to persistence of HTLV-1-transformed lymphocytes and to the development of HTLV-1-associated disease.
Also flagged:serotonin transporterSLC6A4SERTserotoninsynapsereuptake
Journal Article2011-08-16✓ 5 SnippetsAvula R, Rand A, Black JL, O'Kane DJ.
In-Text Gene Mentions
Discussion)
…Serotonin uptake is genetically controlled, and dysregulation of 5-HTT function has been reported in various complex behavioral traits and disorders such as depression, bipolar disorder, anxiety, obsessive-compulsive disorder, schizophrenic and neurodegenerative disorders, substance abuse and eating disorders.26, 27, 28, 29, 30, 31 5-HTT is the main target for widely used antidepressants, so it will be beneficial in the future to study the significance of these XL and other rare variants in correlation with selective serotonin reuptake inhibitor therapeutics.…
Abstract)
…The serotonin transporter, called SLC6A4, SERT or 5-HTT, modulates neurotransmission by removal of serotonin from the synapse of serotonergic neurons, facilitating serotonin reuptake into the presynaptic terminus.…
Discussion)
…The 5-HTTLPR region is highly polymorphic, and repeats up to 24 units do exist in humans and are found to be a common occurrence in non-human primates.18 Presence of 5-HTTLPR in humans and simians but not in other mammals like mice may be related to anxiety-related personality traits so common in humans.18 The allelic distribution of the 5-HTT gene has remarkable ethnic variation, and the XL alleles seem to be largely present in the African or African-American population.…
Introduction)
…Variations in the promoter region of 5-HTT have been reported to be associated with differential remission rates following selective serotonin reuptake inhibitor medication treatment.1, 2 The long form of the ins/del promoter variant has 43 or 44 more nucleotides than the short form and has been shown to drive transcription levels to more than twice the level of the S allele.3 In some previous studies, European subjects homozygous for the L allele of the ins/del promoter variant have been reported to benefit more from treatment with medications that block serotonin reuptake than subjects without the L allele.1, 4 Nakamura et al.,5 after isolating and sequencing all the repeat units in the promoter, categorized four kinds of S allelic variants and six different L allelic variants, based upon the sequence of the different repeats.…
Abstract)
…SLC6A4, SERT or5-HTT, modulates neurotransmission …
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The serotonin transporter, called SLC6A4, SERT or 5-HTT, modulates neurotransmission by removal of serotonin from the synapse of serotonergic neurons, facilitating serotonin reuptake into the presynaptic terminus. Selective serotonin reuptake inhibitors block the action of the serotonin transporter and are used to treat depression and other neuropsychiatric disorders. Three polymorphisms in the 5-HTT gene have been implicated in treatment response and neuropsychiatric disorders. A 44-bp promoter ins/del polymorphism (5-HTTLPR) produces primarily long and/or short alleles due to either 14 (short) or 16 (long) repeats of variably conserved 20-23 bp units. Also implicated, a 17-18 bp variable number tandem repeat found in intron2 (StIn2) is expressed as triallelic content with 9, 10, or 12 repeats (StIn2.9, StIn2.10 or StIn2.12). Finally, a single nucleotide polymorphism rs25531 located within the promoter polymorphic-linked region alters the function of the long promoter allele. We developed a PCR-based fragment analysis assay, which is analyzed on an ABI sequencer, whereby we are able to detect all three genotypes simultaneously. Using this technique, we identified novel sequences, which demonstrate promoter repeat regions containing (1) a 17 repeat with rs25531 A/G polymorphism, (2) two with 18-repeat units, (3) one with 20-repeat units and (4) a 24-repeat sequence. The novel repeats were confirmed by direct sequencing of gel-purified amplicons.
Also flagged:type 2 diabetesinsulinCdkal1methylthiotransferasesecretionglucose
Journal Article2011-08-15✓ 1 SnippetWei FY, Suzuki T, Watanabe S, Kimura S, Kaitsuka T, Fujimura A, Matsui H, Atta M, Michiue H, Fontecave M, Yamagata K, Suzuki T, Tomizawa K.
In-Text Gene Mentions
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The worldwide prevalence of type 2 diabetes (T2D), which is caused by a combination of environmental and genetic factors, is increasing. With regard to genetic factors, variations in the gene encoding Cdk5 regulatory associated protein 1-like 1 (Cdkal1) have been associated with an impaired insulin response and increased risk of T2D across different ethnic populations, but the molecular function of this protein has not been characterized. Here, we show that Cdkal1 is a mammalian methylthiotransferase that biosynthesizes 2-methylthio-N6-threonylcarbamoyladenosine (ms2t6A) in tRNA(Lys)(UUU) and that it is required for the accurate translation of AAA and AAG codons. Mice with pancreatic β cell-specific KO of Cdkal1 (referred to herein as β cell KO mice) showed pancreatic islet hypertrophy, a decrease in insulin secretion, and impaired blood glucose control. In Cdkal1-deficient β cells, misreading of Lys codon in proinsulin occurred, resulting in a reduction of glucose-stimulated proinsulin synthesis. Moreover, expression of ER stress-related genes was upregulated in these cells, and abnormally structured ER was observed. Further, the β cell KO mice were hypersensitive to high fat diet-induced ER stress. These findings suggest that glucose-stimulated translation of proinsulin may require fully modified tRNA(Lys)(UUU), which could potentially explain the molecular pathogenesis of T2D in patients carrying cdkal1 risk alleles.
Also flagged:polyacrylamideHeart diseasedeathamino acidcardiovascular diseasessodium dodecyl sulfate
Journal Article2011-08-15No SnippetsLi ZJ, Liu N, Han QD, Zhang YY.
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<h4>Aim</h4>To study and establish a proteome reference map and regulation network of neonatal rat cardiomyocyte.<h4>Methods</h4>Cultured cardiomyocytes of neonatal rats were used. All proteins expressed in the cardiomyocytes were separated and identified by two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Biological networks and pathways of the neonatal rat cardiomyocytes were analyzed using the Ingenuity Pathway Analysis (IPA) program (www.ingenuity.com). A 2-DE database was made accessible on-line by Make2ddb package on a web server.<h4>Results</h4>More than 1000 proteins were separated on 2D gels, and 148 proteins were identified. The identified proteins were used for the construction of an extensible markup language-based database. Biological networks and pathways were constructed to analyze the functions associate with cardiomyocyte proteins in the database. The 2-DE database of rat cardiomyocyte proteins can be accessed at http://2d.bjmu.edu.cn.<h4>Conclusion</h4>A proteome reference map and regulation network of the neonatal rat cardiomyocytes have been established, which may serve as an international platform for storage, analysis and visualization of cardiomyocyte proteomic data.
Journal Article2011-08-15No SnippetsRacine J, Gerber V, Feutz MM, Riley CP, Adamec J, Swinburne JE, Couetil LL.
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<h4>Background</h4>Recurrent airway obstruction (RAO) is a severe chronic respiratory disease affecting horses worldwide, though mostly in the Northern hemisphere. Environmental as well as genetic factors strongly influence the course and prognosis of the disease. Research has been focused on characterization of immunologic factors contributing to inflammatory responses, on genetic linkage analysis, and, more recently, on proteomic analysis of airway secretions from affected horses. The goal of this study was to investigate the interactions between eight candidate genes previously identified in a genetic linkage study and proteins expressed in bronchoalveolar lavage fluid (BALF) collected from healthy and RAO-affected horses. The analysis was carried out with Ingenuity Pathway Analysis® bioinformatics software.<h4>Results</h4>The gene with the greatest number of indirect interactions with the set of proteins identified is Interleukin 4 Receptor (IL-4R), whose protein has also been detected in BALF. Interleukin 21 receptor and chemokine (C-C motif) ligand 24 also showed a large number of interactions with the group of detected proteins. Protein products of other genes like that of SOCS5, revealed direct interactions with the IL-4R protein. The interacting proteins NOD2, RPS6KA5 and FOXP3 found in several pathways are reported regulators of the NFκB pathway.<h4>Conclusions</h4>The pathways generated with IL-4R highlight possible important intracellular signaling cascades implicating, for instance, NFκB. Furthermore, the proposed interaction between SOCS5 and IL-4R could explain how different genes can lead to identical clinical RAO phenotypes, as observed in two Swiss Warmblood half sibling families because these proteins interact upstream of an important cascade where they may act as a functional unit.
Also flagged:Roquindeathamino acidautoimmune syndromeinducible T cell co-stimulatorICOS
Journal Article2011-08-15✓ 5 SnippetsBertossi A, Aichinger M, Sansonetti P, Lech M, Neff F, Pal M, Wunderlich FT, Anders HJ, Klein L, Schmidt-Supprian M.
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…Vinuesa et al. (2005) identified the M199R amino acid substitution in the putative E3 ubiquitin ligase Roquin/Rc3h1 as the cause of the spontaneous lupus-like autoimmune disease characterizing the sanroque mouse strain. san/san mice display splenomegaly, lymphadenopathy, plasmacytosis, spontaneous germinal center formation, and glomerulonephritis with immune complex deposition. High affinity anti-DNA autoantibodies can be detected as early as 6 wk after birth (Vinuesa et al., 2005). The dominant disease-preventing mechanism of Roquin is thought to be the inhibition of inappropriate inducible T cell co-stimulator (ICOS) expression on T cells (Linterman et al., 2009a; Yu and Vinuesa, 2010) through direct ICOS messenger RNA (mRNA) binding and targeting to P-bodies and components of the decapping machinery (Athanasopoulos et al., 2010; Glasmacher et al., 2010). The M199R sanroque mutation is located in a novel protein domain termed ROQ, which so far has been identified only in Roquin and its paralogue Mnab. The ROQ domain is critical for ICOS mRNA binding and repression. Because the M199R mutation does not affect binding to ICOS mRNA, it has been postulated that it interferes with Roquin’s ability to interact with as yet unknown critical effector proteins (Athanasopoulos et al., 2010).…
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…generate a conditionalrc3h1allele, we cloned…
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…intron of theRc3h1gene.…
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…Rc3h1F , Nestin-cre…
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…he following antibodies: anti-Rc3h1(Bethyl Laboratories, Inc.),…
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The substitution of one amino acid in the Roquin protein by the sanroque mutation induces a dramatic autoimmune syndrome in mice. This is believed to occur through ectopic expression of inducible T cell co-stimulator (ICOS) and unrestrained differentiation of follicular T helper cells, which induce spontaneous germinal center reactions to self-antigens. In this study, we demonstrate that tissue-specific ablation of Roquin in T or B cells, in the entire hematopoietic system, or in epithelial cells of transplanted thymi did not cause autoimmunity. Loss of Roquin induced elevated expression of ICOS through T cell-intrinsic and -extrinsic mechanisms, which itself was not sufficient to break self-tolerance. Instead, ablation of Roquin in the hematopoietic system caused defined changes in immune homeostasis, including the expansion of macrophages, eosinophils, and T cell subsets, most dramatically CD8 effector-like T cells, through cell-autonomous and nonautonomous mechanisms. Germline Roquin deficiency led to perinatal lethality, which was partially rescued on the genetic background of an outbred strain. However, not even complete absence of Roquin resulted in overt self-reactivity, suggesting that the sanroque mutation induces autoimmunity through an as yet unknown mechanism.
Molecular knockdown of disease proteins and restoration of wild-type activity represent a promising but challenging strategy for the treatment of diseases that result from the accumulation of misfolded proteins (i.e., Huntington disease, amyotrophic lateral sclerosis, and α-1 antitrypsin deficiency). In this study we used alpha-1 antitrypsin (AAT) deficiency with the piZZ mutant phenotype as a model system to evaluate the efficiency of gene-delivery approaches that both silence the piZZ transcript (e.g., shRNA) and restore circulating wild-type AAT expression from resistant codon-optimized AAT (AAT-opt) transgene cassette using adeno-associated virus (AAV) vector delivery. After systemic injection of a self-complimentary AAV serotype 8 (scAAV8) vector encoding shRNA in piZZ transgenic mice, both mutant AAT mRNA in the liver and defected serum protein level were inhibited by 95%, whereas liver pathology, as monitored by dPAS and fibrosis staining, reversed. To restore blood AAT levels in AAV8/shRNA-treated mice, several strategies to restore functional AAT levels were tested, including using AAV AAT-opt transgene cassettes targeted to muscle and liver, or combination vectors carrying piZZ shRNA and AAT-opt transgenes separately, or a single bicistronic AAV vector. With these molecular approaches, we observed over 90% knockdown of mutant AAT with a 13- to 30-fold increase of circulating wild-type AAT protein from the shRNA-resistant AAT-opt cassette. The molecular approaches applied in this study can simultaneously prevent liver pathology and restore blood AAT concentration in AAT deficiencies. Based on these observations, similar gene-therapy strategies could be considered for any diseases caused by accumulation of misfolded proteins.
Host genetic factors that modify risk of pneumococcal disease may help target future public health interventions to individuals at highest risk of disease. We linked data from population-based surveillance for invasive pneumococcal disease (IPD) with state-based newborn dried bloodspot repositories to identify biological samples from individuals who developed invasive pneumococcal disease. Genomic DNA was extracted from 366 case and 732 anonymous control samples. TagSNPs were selected in 34 candidate genes thought to be associated with host response to invasive pneumococcal disease, and a total of 326 variants were successfully genotyped. Among 543 European Americans (EA) (182 cases and 361 controls), and 166 African Americans (AA) (53 cases and 113 controls), common variants in surfactant protein D (SFTPD) are consistently underrepresented in IPD. SFTPD variants with the strongest association for IPD are intronic rs17886286 (allelic OR 0.45, 95% confidence interval (CI) [0.25, 0.82], with p = 0.007) in EA and 5' flanking rs12219080 (allelic OR 0.32, 95%CI [0.13, 0.78], with p = 0.009) in AA. Variants in CD46 and IL1R1 are also associated with IPD in both EA and AA, but with effects in different directions; FAS, IL1B, IL4, IL10, IL12B, SFTPA1, SFTPB, and PTAFR variants are associated (p≤0.05) with IPD in EA or AA. We conclude that variants in SFTPD may protect against IPD in EA and AA and genetic variation in other host response pathways may also contribute to risk of IPD. While our associations are not corrected for multiple comparisons and therefore must be replicated in additional cohorts, this pilot study underscores the feasibility of integrating public health surveillance with existing, prospectively collected, newborn dried blood spot repositories to identify host genetic factors associated with infectious diseases.
Also flagged:intellectual disabilitydevelopmental delayepilepsyautismautism spectrum disorderscongenital birth defects
Journal Article2011-08-14No SnippetsCooper GM, Coe BP, Girirajan S, Rosenfeld JA, Vu TH, Baker C, Williams C, Stalker H, Hamid R, Hannig V, Abdel-Hamid H, Bader P, McCracken E, Niyazov D, Leppig K, Thiese H, Hummel M, Alexander N, Gorski J, Kussmann J, Shashi V, Johnson K, Rehder C, Ballif BC, Shaffer LG, Eichler EE.
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To understand the genetic heterogeneity underlying developmental delay, we compared copy number variants (CNVs) in 15,767 children with intellectual disability and various congenital defects (cases) to CNVs in 8,329 unaffected adult controls. We estimate that ∼14.2% of disease in these children is caused by CNVs >400 kb. We observed a greater enrichment of CNVs in individuals with craniofacial anomalies and cardiovascular defects compared to those with epilepsy or autism. We identified 59 pathogenic CNVs, including 14 new or previously weakly supported candidates, refined the critical interval for several genomic disorders, such as the 17q21.31 microdeletion syndrome, and identified 940 candidate dosage-sensitive genes. We also developed methods to opportunistically discover small, disruptive CNVs within the large and growing diagnostic array datasets. This evolving CNV morbidity map, combined with exome and genome sequencing, will be critical for deciphering the genetic basis of developmental delay, intellectual disability and autism spectrum disorders.
Also flagged:Fragile X Syndromeintellectual disabilityIDautismFragile X Mental Retardation ProteinFMRP
Journal Article2011-08-13No SnippetsDe Rubeis S, Bagni C.
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The Fragile X syndrome (FXS) is a leading cause of intellectual disability (ID) and autism. The disease is caused by mutations or loss of the Fragile X Mental Retardation Protein (FMRP), an RNA-binding protein playing multiple functions in RNA metabolism. The expression of a large set of neuronal mRNAs is altered when FMRP is lost, thus causing defects in neuronal morphology and physiology. FMRP regulates mRNA stability, dendritic targeting, and protein synthesis. At synapses, FMRP represses protein synthesis by forming a complex with the Cytoplasmic FMRP Interacting Protein 1 (CYFIP1) and the cap-binding protein eIF4E. Here, we review the clinical, genetic, and molecular aspects of FXS with a special focus on the receptor signaling that regulates FMRP-dependent protein synthesis. We further discuss the FMRP-CYFIP1 complex and its potential relevance for ID and autism.
Also flagged:Huntington's diseaseHDgene expressionHdhpathogenesisneurodegenerative disorders
Journal Article2011-08-12✓ 1 SnippetFossale E, Seong IS, Coser KR, Shioda T, Kohane IS, Wheeler VC, Gusella JF, MacDonald ME, Lee JM.
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Huntington's disease (HD) involves marked early neurodegeneration in the striatum, whereas the cerebellum is relatively spared despite the ubiquitous expression of full-length mutant huntingtin, implying that inherent tissue-specific differences determine susceptibility to the HD CAG mutation. To understand this tissue specificity, we compared early mutant huntingtin-induced gene expression changes in striatum to those in cerebellum in young Hdh CAG knock-in mice, prior to onset of evident pathological alterations. Endogenous levels of full-length mutant huntingtin caused qualitatively similar, but quantitatively different gene expression changes in the two brain regions. Importantly, the quantitatively different responses in the striatum and cerebellum in mutant mice were well accounted for by the intrinsic molecular differences in gene expression between the striatum and cerebellum in wild-type animals. Tissue-specific gene expression changes in response to the HD mutation, therefore, appear to reflect the different inherent capacities of these tissues to buffer qualitatively similar effects of mutant huntingtin. These findings highlight a role for intrinsic quantitative tissue differences in contributing to HD pathogenesis, and likely to other neurodegenerative disorders exhibiting tissue-specificity, thereby guiding the search for effective therapeutic interventions.
Bone morphogenetic protein (BMP) signaling induces hepatic expression of the peptide hormone hepcidin. Hepcidin reduces serum iron levels by promoting degradation of the iron exporter ferroportin. A relative deficiency of hepcidin underlies the pathophysiology of many of the genetically distinct iron overload disorders, collectively termed hereditary hemochromatosis. Conversely, chronic inflammatory conditions and neoplastic diseases can induce high hepcidin levels, leading to impaired mobilization of iron stores and the anemia of chronic disease. Two BMP type I receptors, Alk2 (Acvr1) and Alk3 (Bmpr1a), are expressed in murine hepatocytes. We report that liver-specific deletion of either Alk2 or Alk3 causes iron overload in mice. The iron overload phenotype was more marked in Alk3- than in Alk2-deficient mice, and Alk3 deficiency was associated with a nearly complete ablation of basal BMP signaling and hepcidin expression. Both Alk2 and Alk3 were required for induction of hepcidin gene expression by BMP2 in cultured hepatocytes or by iron challenge in vivo. These observations demonstrate that one type I BMP receptor, Alk3, is critically responsible for basal hepcidin expression, whereas 2 type I BMP receptors, Alk2 and Alk3, are required for regulation of hepcidin gene expression in response to iron and BMP signaling.
…Moreover, hippocampal gene expression profiles suggest that distinct molecular mechanisms mediate the behavioral effects of the 5-Htt genotype, PS exposure, and their interaction.…
Discussion)
…Conversely, adult 5-Htt +/− mice showed enhanced memory performance as well as signs of reduced anxiety as compared to WT offspring.…
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…Another recent investigation by Jones and coworkers [42] showed that offspring of both 5-Htt +/− and WT dams stressed during pregnancy showed signs of decreased anxiety in the elevated plus maze (increased time spent in the open arms; as compared to control offspring), whereas, at the same time, maternal stress exposure increased anxiety-like behavior in the open field test (reduced time spent in the centre) in offspring from WT mothers only.…
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…For this purpose, the effects of PS on cognition, anxiety- and depression-related behavior were examined using a maternal restraint stress paradigm of PS in C57BL6 wild-type (WT) and heterozygous 5-Htt deficient (5-Htt +/−) mice.…
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…prenatal stress in 5-Httdeficient mice: towards…
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Prenatal stress (PS) has been shown to influence the development of the fetal brain and to increase the risk for the development of psychiatric disorders in later life. Furthermore, the variation of human serotonin transporter (5-HTT, SLC6A4) gene was suggested to exert a modulating effect on the association between early life stress and the risk for depression. In the present study, we used a 5-Htt×PS paradigm to investigate whether the effects of PS are dependent on the 5-Htt genotype. For this purpose, the effects of PS on cognition, anxiety- and depression-related behavior were examined using a maternal restraint stress paradigm of PS in C57BL6 wild-type (WT) and heterozygous 5-Htt deficient (5-Htt +/-) mice. Additionally, in female offspring, a genome-wide hippocampal gene expression profiling was performed using the Affymetrix GeneChip® Mouse Genome 430 2.0 Array. 5-Htt +/- offspring showed enhanced memory performance and signs of reduced anxiety as compared to WT offspring. In contrast, exposure of 5-Htt +/- mice to PS was associated with increased depressive-like behavior, an effect that tended to be more pronounced in female offspring. Further, 5-Htt genotype, PS and their interaction differentially affected the expression of numerous genes and related pathways within the female hippocampus. Specifically, MAPK and neurotrophin signaling were regulated by both the 5-Htt +/- genotype and PS exposure, whereas cytokine and Wnt signaling were affected in a 5-Htt genotype×PS manner, indicating a gene×environment interaction at the molecular level. In conclusion, our data suggest that although the 5-Htt +/- genotype shows clear adaptive capacity, 5-Htt +/- mice--particularly females--at the same time appear to be more vulnerable to developmental stress exposure when compared to WT offspring. Moreover, hippocampal gene expression profiles suggest that distinct molecular mechanisms mediate the behavioral effects of the 5-Htt genotype, PS exposure, and their interaction.
Also flagged:hCAP-D2hCAP-EnucleushCAP-HhCAP-GhCAP-C
Journal Article2011-08-12✓ 1 SnippetKong X, Stephens J, Ball AR, Heale JT, Newkirk DA, Berns MW, Yokomori K.
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…Condensinsare essential for…
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Condensin I is important for chromosome organization and segregation in mitosis. We previously showed that condensin I also interacts with PARP1 in response to DNA damage and plays a role in single-strand break repair. However, whether condensin I physically associates with DNA damage sites and how PARP1 may contribute to this process were unclear. We found that condensin I is preferentially recruited to DNA damage sites enriched for base damage. This process is dictated by PARP1 through its interaction with the chromosome-targeting domain of the hCAP-D2 subunit of condensin I.
Also flagged:polyglutaminetranslation initiationtranslation factorsneurodegenerative diseasesATP-ase family gene 3-like 2AFG3L2
Journal Article2011-08-12✓ 5 SnippetsTeuling E, Bourgonje A, Veenje S, Thijssen K, de Boer J, van der Velde J, Swertz M, Nollen E.
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…To establish the role of these genes in the aggregation of mutant huntingtin (Htt) in human cultured cells, we generated three shRNA-constructs per gene and transfected these in combination with a huntingtin-exon1 construct with 74 glutamines, fused to GFP (Htt-Q74-GFP) to HEK293-cells.…
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…study, we expressedHtt-Q74-GFP and specifically knoc…
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…cultured cells expressingHtt-Q74-GFP led to an…
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…of mutant huntingtin (Htt) in human cultured…
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…fused to GFP (Htt-Q74-GFP) to HEK293-cells.…
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Protein aggregation is a common hallmark of a number of age-related neurodegenerative diseases, including Alzheimer's, Parkinson's, and polyglutamine-expansion disorders such as Huntington's disease, but how aggregation-prone proteins lead to pathology is not known. Using a genome-wide RNAi screen in a C. elegans-model for polyglutamine aggregation, we previously identified 186 genes that suppress aggregation. Using an RNAi screen for human orthologs of these genes, we here present 26 human genes that suppress aggregation of mutant huntingtin in a human cell line. Among these are genes that have not been previously linked to mutant huntingtin aggregation. They include those encoding eukaryotic translation initiation, elongation and translation factors, and genes that have been previously associated with other neurodegenerative diseases, like the ATP-ase family gene 3-like 2 (AFG3L2) and ubiquitin-like modifier activating enzyme 1 (UBA1). Unravelling the role of these genes will broaden our understanding of the pathogenesis of Huntington's disease.
…(with or withouthemochromatosisgene mutations) and…
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Non-alcoholic fatty liver disease (NAFLD) is a common and ubiquitous disorder (Bedogni et al. in Hepatology 42:44-52, 2005; Bellentani et al. in Ann Intern Med 132:112-117, 2000) which in a proportion of subjects leads to non-alcoholic steatohepatitis (NASH), advanced liver disease and hepatocellular carcinoma. Although the factors responsible for progression of disease are still uncertain, there is evidence that insulin resistance (IR) is a key operative mechanism (Angulo et al. in Hepatology 30:1356-1362, 1999) and that two stages are involved. The first is the accumulation of triglycerides in hepatocytes followed by a "second hit" which promotes cellular oxidative stress. Several factors may be responsible for the induction of oxidative stress but hepatic iron has been implicated in various studies. The topic is controversial, however, with early studies showing an association between hepatic iron (with or without hemochromatosis gene mutations) and the progression to hepatic fibrosis. Subsequent studies, however, could not confirm an association between the presence of hepatic iron and any of the histological determinants of NAFLD or NASH. Recent studies have reactivated interest in this subject firstly, with the demonstration that hepatic iron loading increases liver cholesterol synthesis with increased lipid deposition in the liver increasing the cellular lipid burden and secondly, a large clinical study has concluded that hepatocellular iron deposition is associated with an increased risk of hepatic fibrosis, thus, strongly supporting the original observation made over a decade ago. An improvement in insulin sensitivity has been demonstrated following phlebotomy therapy but a suitably powered controlled clinical trial is required before this treatment can be implemented.
Menin, a ubiquitously expressed protein, is the product of the multiple endocrine neoplasia type I (Men1) gene, mutations of which cause tumors primarily of the parathyroid, endocrine pancreas, and anterior pituitary. Menin-null mice display early embryonic lethality, and thus imply a critical role for menin in early development. In this study, using the P19 embryonic carcinoma stem cells, we studied menin's role in cell differentiation. Menin expression is induced in P19 cell aggregates by retinoic acid (RA). Menin over-expressing stable clones proliferated in a significantly reduced rate compared to the empty vector harboring cells. RA induced cell death in aggregated menin over-expressing cells. However, in the absence of RA, specific populations of the aggregated menin over-expressing cells displayed the characteristic of an endodermal phenotype by the acquisition of cytokeratin Endo A expression (TROMA-1), a marker for the primitive endoderm, with a concomitant loss of the stem cell marker SSEA-1. Menin's ability to induce endodermal differentiation in specific populations of the aggregated cells in the absence of RA implied that menin could substitute RA by inducing a set of target genes that are RA responsive. Menin over-expressing cells upon aggregation showed a robust expression of RA receptors (RAR), RARα, β, and γ relative to the empty vector-harboring cells. Moreover, endodermal differentiation was inhibited by the pan-RAR antagonist Ro41-5253, suggesting that menin could induce endodermal differentiation of uncommitted cells by functionally modulating the RARs.
Also flagged:embryogenesisgestationmammary tumoursgene expressioncancersbreast cancer
Journal Article2011-08-11✓ 2 SnippetsWansbury O, Mackay A, Kogata N, Mitsopoulos C, Kendrick H, Davidson K, Ruhrberg C, Reis-Filho JS, Smalley MJ, Zvelebil M, Howard BA.
In-Text Gene Mentions
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…Igf1, Kera, On,Ptgis, Thbs2, Timp3, Tmeff2…
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…include Elf5 andSox6[ 5 ,…
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<h4>Introduction</h4>The mammary primordium forms during embryogenesis as a result of inductive interactions between its constitutive tissues, the mesenchyme and epithelium, and represents the earliest evidence of commitment to the mammary lineage. Previous studies of embryonic mouse mammary epithelium indicated that, by mid-gestation, these cells are determined to a mammary cell fate and that a stem cell population has been delimited. Mammary mesenchyme can induce mammary development from simple epithelium even across species and classes, and can partially restore features of differentiated tissue to mouse mammary tumours in co-culture experiments. Despite these exciting properties, the molecular identity of embryonic mammary cells remains to be fully characterised.<h4>Methods</h4>Here, we define the transcriptome of the mammary primordium and the two distinct cellular compartments that comprise it, the mammary primordial bud epithelium and mammary mesenchyme. Pathway and network analysis was performed and comparisons of embryonic mammary gene expression profiles to those of both postnatal mouse and human mammary epithelial cell sub-populations and stroma were made.<h4>Results</h4>Several of the genes we have detected in our embryonic mammary cell signatures were previously shown to regulate mammary cell fate and development, but we also identified a large number of novel candidates. Additionally, we determined genes that were expressed by both embryonic and postnatal mammary cells, which represent candidate regulators of mammary cell fate, differentiation and progenitor cell function that could signal from mammary lineage inception during embryogenesis through postnatal development. Comparison of embryonic mammary cell signatures with those of human breast cells identified potential regulators of mammary progenitor cell functions conserved across species.<h4>Conclusions</h4>These results provide new insights into genetic regulatory mechanisms of mammary development, particularly identification of novel potential regulators of mammary fate and mesenchymal-epithelial cross-talk. Since cancers may represent diseases of mesenchymal-epithelial communications, we anticipate these results will provide foundations for further studies into the fundamental links between developmental, stem cell and breast cancer biology.
<h4>Background</h4>Cell migration is essential during development and in human disease progression including cancer. Most cell migration studies concentrate on known or predicted components of migration pathways.<h4>Results</h4>Here we use data from a genome-wide RNAi morphology screen in Drosophila melanogaster cells together with bioinformatics to identify 26 new regulators of morphology and cytoskeletal organization in human cells. These include genes previously implicated in a wide range of functions, from mental retardation, Down syndrome and Huntington's disease to RNA and DNA-binding genes. We classify these genes into seven groups according to phenotype and identify those that affect cell migration. We further characterize a subset of seven genes, FAM40A, FAM40B, ARC, FMNL3, FNBP3/FBP11, LIMD1 and ZRANB1, each of which has a different effect on cell shape, actin filament distribution and cell migration. Interestingly, in several instances closely related isoforms with a single Drosophila homologue have distinct phenotypes. For example, FAM40B depletion induces cell elongation and tail retraction defects, whereas FAM40A depletion reduces cell spreading.<h4>Conclusions</h4>Our results identify multiple regulators of cell migration and cytoskeletal signalling that are highly conserved between Drosophila and humans, and show that closely related paralogues can have very different functions in these processes.
Also flagged:chromosomeschromosomeprostate cancercancerBCRABL1
Journal Article2011-08-11✓ 4 SnippetsKim D, Salzberg SL.
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…- ABL1 ,ARFGEF2- SULF2 ,…
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…- BCAS3 ,ARFGEF2- SULF2 ,…
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…of fusion candidates:ARFGEF2- SULF2 (SPER,…
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…DASPER values fromARFGEF2- SULF2 and…
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TopHat-Fusion is an algorithm designed to discover transcripts representing fusion gene products, which result from the breakage and re-joining of two different chromosomes, or from rearrangements within a chromosome. TopHat-Fusion is an enhanced version of TopHat, an efficient program that aligns RNA-seq reads without relying on existing annotation. Because it is independent of gene annotation, TopHat-Fusion can discover fusion products deriving from known genes, unknown genes and unannotated splice variants of known genes. Using RNA-seq data from breast and prostate cancer cell lines, we detected both previously reported and novel fusions with solid supporting evidence. TopHat-Fusion is available at http://tophat-fusion.sourceforge.net/.
Also flagged:Peroxiredoxin 2thiol-specific peroxidaseatherosclerosisp65c-JunPrdx2
Journal Article2011-08-11✓ 1 SnippetPark JG, Yoo JY, Jeong SJ, Choi JH, Lee MR, Lee MN, Hwa Lee J, Kim HC, Jo H, Yu DY, Kang SW, Rhee SG, Lee MH, Oh GT.
In-Text Gene Mentions
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<h4>Rationale</h4>Peroxiredoxin 2 (Prdx2), a thiol-specific peroxidase, has been reported to regulate proinflammatory responses, vascular remodeling, and global oxidative stress.<h4>Objective</h4>Although Prdx2 has been proposed to retard atherosclerosis development, no direct evidence and mechanisms have been reported.<h4>Methods and results</h4>We show that Prdx2 is highly expressed in endothelial and immune cells in atherosclerotic lesions and blocked the increase of endogenous H(2)O(2) by atherogenic stimulation. Deficiency of Prdx2 in apolipoprotein E-deficient (ApoE(-/-)) mice accelerated plaque formation with enhanced activation of p65, c-Jun, JNKs, and p38 mitogen-activated protein kinase; and these proatherogenic effects of Prdx2 deficiency were rescued by administration of the antioxidant ebselen. In bone marrow transplantation experiments, we found that Prdx2 has a major role in inhibiting atherogenic responses in both vascular and immune cells. Prdx2 deficiency resulted in increased expression of vascular adhesion molecule-1, intercellular adhesion molecule-1, and monocyte chemotactic protein-1, which led to increased immune cell adhesion and infiltration into the aortic intima. Compared with deficiency of glutathione peroxidase 1 or catalase, Prdx2 deficiency showed a severe predisposition to develop atherosclerosis.<h4>Conclusions</h4>Prdx2 is a specific peroxidase that inhibits atherogenic responses in vascular and inflammatory cells, and specific activation of Prdx2 may be an effective means of antiatherogenic therapy.
Also flagged:bladder neoplasmsclottingprothrombinantithrombin IIIprotein Cprotein S
Journal Article2011-08-11✓ 1 SnippetDi Loria A, Piantedosi D, Cortese L, Roperto S, Urraro C, Paciello O, Guccione J, Britti D, Ciaramella P.
In-Text Gene Mentions
Abstract)
…(PT), antithrombin III (ATIII), protein C, protein…
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Primary haemostasis (bleeding and blood clotting time), activated partial thromboplastin time (APTT), prothrombin time (PT), antithrombin III (ATIII), protein C, protein S, fibrinogen and D-dimer were determined in 13 cattle affected by chronic enzootic haematuria (CEH) and bladder neoplasms and 10 healthy cattle (control group). Increases in antithrombin III and protein S activities (P<0.01) and protein C and fibrinogen plasma levels (P<0.05) were observed in sick animals, while activated partial thromboplastin time, prothrombin time, and D-dimer did not show significant differences when compared to healthy animals. The clotting profile observed does not seem responsible for the chronic bleeding typical of CEH. The observed modification of some coagulation markers may derive from multiple interactions among cancer, inflammation and viral infection status typical of this syndrome.
Fatty acid amide hydrolase (FAAH) is an integral membrane enzyme that degrades the endocannabinoid anandamide (AEA) and several other bioactive lipid amides. The catalytic mechanism of FAAH has been largely elucidated, and structural models of the enzyme suggest that it may recruit its hydrophobic substrates directly from the lipid bilayer of the cell. Testing this hypothesis, however, requires new tools to explore FAAH-substrate interactions in native cell membranes. Here, we have addressed this problem by creating clickable, photoreactive inhibitors that probe the microenvironment surrounding the FAAH active site. We show that these probes can be used directly in cell membranes, where distinct crosslinked adducts are observed for inhibitors that are buried within versus exposed to the external environment of the FAAH active site.
<h4>Background</h4>Acyl-acyl carrier protein thioesterases (acyl-ACP TEs) catalyze the hydrolysis of the thioester bond that links the acyl chain to the sulfhydryl group of the phosphopantetheine prosthetic group of ACP. This reaction terminates acyl chain elongation of fatty acid biosynthesis, and in plant seeds it is the biochemical determinant of the fatty acid compositions of storage lipids.<h4>Results</h4>To explore acyl-ACP TE diversity and to identify novel acyl ACP-TEs, 31 acyl-ACP TEs from wide-ranging phylogenetic sources were characterized to ascertain their in vivo activities and substrate specificities. These acyl-ACP TEs were chosen by two different approaches: 1) 24 TEs were selected from public databases on the basis of phylogenetic analysis and fatty acid profile knowledge of their source organisms; and 2) seven TEs were molecularly cloned from oil palm (Elaeis guineensis), coconut (Cocos nucifera) and Cuphea viscosissima, organisms that produce medium-chain and short-chain fatty acids in their seeds. The in vivo substrate specificities of the acyl-ACP TEs were determined in E. coli. Based on their specificities, these enzymes were clustered into three classes: 1) Class I acyl-ACP TEs act primarily on 14- and 16-carbon acyl-ACP substrates; 2) Class II acyl-ACP TEs have broad substrate specificities, with major activities toward 8- and 14-carbon acyl-ACP substrates; and 3) Class III acyl-ACP TEs act predominantly on 8-carbon acyl-ACPs. Several novel acyl-ACP TEs act on short-chain and unsaturated acyl-ACP or 3-ketoacyl-ACP substrates, indicating the diversity of enzymatic specificity in this enzyme family.<h4>Conclusion</h4>These acyl-ACP TEs can potentially be used to diversify the fatty acid biosynthesis pathway to produce novel fatty acids.
Also flagged:Estrogen receptor-βbiosynthesisEstrogen receptorsESR2PTGS2cyclooxygenase-1
Journal Article2011-08-10✓ 4 SnippetsSu EJ, Ernst L, Abdallah N, Chatterton R, Xin H, Monsivais D, Coon J, Bulun SE.
In-Text Gene Mentions
Abstract)
…ESR2 mediates prostaglandin H2 substrate availability and, in the setting of differential regulation of AKR1C3 and PTGIS, altered the balance between vasodilatory and vasoconstricting prostanoid production.<h4>Conclusions</h4>Higher ESR2 expression in the placental vasculature of FGR subjects with abnormal blood flow is associated with an endothelial cell phenotype that preferentially produces vasoconstrictive prostanoids.…
Abstract)
…reased prostacyclin synthase (PTGIS), with opposing results…
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…of AKR1C3 andPTGIS, altered the balance…
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…PTGIS…
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<h4>Context</h4>Fetal growth restriction (FGR) due to placental dysfunction impacts short- and long-term neonatal outcomes. Abnormal umbilical artery Doppler velocimetry indicating elevated fetoplacental vascular resistance has been associated with fetal morbidity and mortality. Estrogen receptors are regulators of vasomotor tone, and fetoplacental endothelium expresses estrogen receptor-β (ESR2) as its sole estrogen receptor.<h4>Objective</h4>Our objective was to elucidate the mechanism whereby ESR2 regulates placental villous endothelial cell prostanoid biosynthesis.<h4>Design and participants</h4>We conducted immunohistochemical analysis of human placental specimens and studies of primary fetoplacental endothelial cells isolated from subjects with uncomplicated pregnancies.<h4>Main outcome measures</h4>We evaluated in vivo levels of ESR2 and cyclooxygenase-2 (PTGS2) in villous endothelial cells from fetuses with or without FGR and/or abnormal umbilical artery Doppler indices and in vitro effects of ESR2 on prostanoid biosynthetic gene expression.<h4>Results</h4>ESR2 and PTGS2 expression were significantly higher within subjects with FGR with abnormal umbilical artery Doppler indices in comparison with controls (P < 0.01). ESR2 knockdown led to decreased cyclooxygenase-1 (PTGS1), PTGS2, prostaglandin F synthase (AKR1C3), and increased prostacyclin synthase (PTGIS), with opposing results found after ESR2 overexpression (P < 0.05). ESR2 mediates prostaglandin H2 substrate availability and, in the setting of differential regulation of AKR1C3 and PTGIS, altered the balance between vasodilatory and vasoconstricting prostanoid production.<h4>Conclusions</h4>Higher ESR2 expression in the placental vasculature of FGR subjects with abnormal blood flow is associated with an endothelial cell phenotype that preferentially produces vasoconstrictive prostanoids. Endothelial ESR2 appears to be a master regulator of prostanoid biosynthesis and contributes to high-resistance fetoplacental blood flow, thereby increasing morbidity and mortality associated with FGR.
Also flagged:neuropsychiatric disorderscatechol-O-methyl transferaseCOMTserotonin transporterSLC6A4neuropeptide Y
Journal Article2011-08-10No SnippetsBevilacqua L, Goldman D.
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Emotion is critical to most aspects of human behavior, and individual differences in systems recruited to process emotional stimuli, expressed as variation in emotionality, are characteristic of several neuropsychiatric disorders. We examine the genetic origins of individual differences in emotion processing by focusing on functional variants at five genes: catechol-O-methyltransferase (COMT), serotonin transporter (SLC6A4), neuropeptide Y (NPY), a glucocorticoid receptor-regulating co-chaperone of stress proteins (FKBP5) and pituitary adenylate cyclase-activating polypeptide receptor (ADCYAP1R1). These represent a range of effects of genes on emotion as well as the variety of mechanisms and factors, such as stress, that modify these effects. The new genomic era of genome-wide association studies (GWAS) and deep sequencing may yield a wealth of new loci modulating emotion. The effects of these genes can be validated by neuroimaging, neuroendocrine and other studies accessing intermediate phenotypes, deepening our understanding of mechanisms of emotion and variation in emotionality.
Examining the interplay of genes, experience and the brain is crucial to understanding psychopathology. We review the recent gene-environment interaction (G×E) and imaging genetics literature with the goal of developing models to bridge these approaches within single imaging gene-environment interaction (IG×E) studies. We explore challenges inherent in both G×E and imaging genetics and highlight studies that address these limitations. In specifying IG×E models, we examine statistical methods for combining these approaches, and explore plausible biological mechanisms (e.g. epigenetics) through which these conditional mechanisms can be understood. Finally, we discuss the potential contribution that IG×E studies can make to understanding psychopathology and developing more personalized and effective prevention and treatment.
Also flagged:Gene expressionHDHuntington's diseaseautosomalneurodegenerative disease
Journal Article2011-08-10✓ 2 SnippetsBowles KR, Brooks SP, Dunnett SB, Jones L.
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Abstract)
…Huntington's disease (HD) is an autosomal dominant neurodegenerative disease, resulting in expansion of the CAG repeat in exon 1 of the HTT gene.…
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…1 of theHTTgene.…
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Huntington's disease (HD) is an autosomal dominant neurodegenerative disease, resulting in expansion of the CAG repeat in exon 1 of the HTT gene. The resulting mutant huntingtin protein has been implicated in the disruption of a variety of cellular functions, including transcription. Mouse models of HD have been central to the development of our understanding of gene expression changes in this disease, and are now beginning to elucidate the relationship between gene expression and behaviour. Here, we review current mouse models of HD and their characterisation in terms of gene expression. In addition, we look at how this can inform behaviours observed in mouse models of disease. The relationship between gene expression and behaviour in mouse models of HD is important, as this will further our knowledge of disease progression and its underlying molecular events, highlight new treatment targets, and potentially provide new biomarkers for therapeutic trials.
Also flagged:cysteinepeptidesamino acidaspartic acidalanineoxygen
Journal Article2011-08-10✓ 1 SnippetBasile F, Zhang S, Kandar SK, Lu L.
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We report on the characterization by mass spectrometry (MS) of a rapid, reagentless and site-specific cleavage at the N-terminus of the amino acid cysteine (C) in peptides and proteins induced by the thermal decomposition at 220-250 °C for 10 s in solid samples. This thermally induced cleavage at C occurs under the same conditions and simultaneously to our previously reported thermally induced site-specific cleavage at the C-terminus of aspartic acid (D) (Zhang, S.; Basile, F. J. Proteome Res. 2007, 6, (5), 1700-1704). The C cleavage proceeds through cleavage of the nitrogen and α-carbon bond (N-terminus) of cysteine and produces modifications at the cleavage site with an amidation (-1 Da) of the N-terminal thermal decomposition product and a -32 Da mass change of the C-terminal thermal decomposition product, the latter yielding either an alanine or β-alanine residue at the N-terminus site. These modifications were confirmed by off-line thermal decomposition electrospray ionization (ESI)-MS, tandem MS (MS/MS) analyses and accurate mass measurements of standard peptides. Molecular oxygen was found to be required for the thermal decomposition and cleavage at C as it induced an initial cysteine thiol side chain oxidation to sulfinic acid. Similar to the thermally induced D cleavage, missed cleavages at C were also observed. The combined thermally induced digestion process at D and C, termed thermal decomposition/digestion (TDD), was observed on several model proteins tested under ambient conditions and the site-specificity of the method confirmed by MS/MS.
Also flagged:pattern-recognition receptorsmembraneToll-like receptorsreceptorsRIG-I-like receptorsdeoxyribonucleic acid
Journal Article2011-08-09No SnippetsKawai T, Akira S.
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The innate immune system recognizes microbial components through pattern-recognition receptors (PRRs), including membrane-bound Toll-like receptors and cytosolic receptors such as RIG-I-like receptors and deoxyribonucleic acid (DNA) sensors. These PRRs trigger distinct signal transduction pathways that culminate in induction of an array of cytokines and other mediators required for host defense. The tripartite motif (TRIM) family is a diverse family of RING finger domain-containing proteins, which are involved in a variety of cellular functions. Importantly, recent studies have shown that they are also involved in the regulation of innate immune responses through the modulation of PRR signalling pathways.
Cancer treatments can be detrimental to fertility; recent literature has focused on the efforts of fertility preservation for this patient population. It should be recognized, however, that several nonmalignant medical conditions and therapeutic interventions could be similarly hazardous to fertility. Some of these nonmalignant diseases and their treatments that can adversely impact the reproductive axis are gastrointestinal diseases, rheumatologic disorders, nonmalignant hematologic conditions, neurologic disorders, renal disorders, gynecologic conditions, and metabolic diseases. Their negative effects on reproductive function are only now being appreciated and include impaired ovarian function, endocrine function, or sexual function and inability to carry a pregnancy to term. Complications and comorbidities associated with certain diseases may limit the success of established fertility preservation options. Recent advances in fertility preservation techniques may provide these patients with new options for childbearing. Here, we review several fertility-threatening conditions and treatments, describe current established and experimental fertility preservation options, and present three initiatives that may help minimize the adverse reproductive effects of these medical conditions and treatments by raising awareness of the issues and options: (1) increase awareness among practitioners about the reproductive consequences of specific diseases and treatments, (2) facilitate referral of patients to fertility-sparing or restorative programs, and (3) provide patient education about the risk of infertility at the time of diagnosis before initiation of treatment.
<h4>Background</h4>Anemia is a common clinical finding in HIV-infected patients and iron deficiency or redistribution may contribute to the development of low hemoglobin levels. Iron overload is associated with a poor prognosis in HIV and Hepatitis C virus infections. Iron redistribution may be caused by inflammation but possibly also by hepatitis C co-infection. We examined the prevalence of anemia and its relation to mortality in a cohort of HIV patients in a setting where injecting drug use (IDU) is a main mode of HIV transmission, and measured serum ferritin and sTfR, in relation to anemia, inflammation, stage of HIV disease, ART and HCV infection.<h4>Methods</h4>Patient characteristics, ART history and iron parameters were recorded from adult HIV patients presenting between September 2007 and August 2009 in the referral hospital for West Java, Indonesia. Kaplan-Meier estimates and Cox's regression were used to assess factors affecting survival. Logistic regression was used to identity parameters associated with high ferritin concentrations.<h4>Results</h4>Anemia was found in 49.6% of 611 ART-naïve patients, with mild (Hb 10.5 -12.99 g/dL for men; and 10.5-11.99 g/dL for women) anemia in 62.0%, and moderate to severe anemia (Hb < 10.5 g/dL) in 38.0%. Anemia remained an independent factor associated with death, also after adjustment for CD4 count and ART (p = 0.008). Seroprevalence of HCV did not differ in patients with (56.9%) or without anemia (59.6%). Serum ferritin concentrations were elevated, especially in patients with anemia (p = 0.07) and/or low CD4 counts (p < 0.001), and were not related to hsCRP or HCV infection. Soluble TfR concentrations were low and not related to Hb, CD4, hsCRP or ART.<h4>Conclusion</h4>HIV-associated anemia is common among HIV-infected patients in Indonesia and strongly related to mortality. High ferritin with low sTfR levels suggest that iron redistribution and low erythropoietic activity, rather than iron deficiency, contribute to anemia. Serum ferritin and sTfR should be used cautiously to assess iron status in patients with advanced HIV infection.
Also flagged:GliomachromosomesGBMcancerGlioblastoma multiformetumors
Journal Article2011-08-09✓ 5 SnippetsYang TH, Kon M, Hung JH, Delisi C.
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Discussion)
…More specifically, each has either been previously associated with cancer (DCC in the Online Mendelian Inheritance in Man (OMIM) [22]; FHIT and DCC in the Genome Association Database (GAD) [23]), or belongs to a gene family that has been previously associated with some form of cancer (the Kinase gene PRKG1, and the GABA receptor subunit gene GABRG3).…
Discussion)
…(c) DCC, the deleted colorectal carcinoma gene, has (as its name implies) been well studied and has been implicated in a number of cancers in addition to colorectal cancer [26].…
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…FHIT, GABRG3, PRKG1,DCC, and ITGB8…
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…with cancer (DCCin the Online…
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…]; FHIT andDCCin the Genome…
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<h4>Background</h4>Glioblastoma multiforme (GBM) tends to occur between the ages of 45 and 70. This relatively early onset and its poor prognosis make the impact of GBM on public health far greater than would be suggested by its relatively low frequency. Tissue and blood samples have now been collected for a number of populations, and predisposing alleles have been sought by several different genome-wide association (GWA) studies. The Cancer Genome Atlas (TCGA) at NIH has also collected a considerable amount of data. Because of the low concordance between the results obtained using different populations, only 14 predisposing single nucleotide polymorphism (SNP) candidates in five genomic regions have been replicated in two or more studies. The purpose of this paper is to present an improved approach to biomarker identification.<h4>Methods</h4>Association analysis was performed with control of population stratifications using the EIGENSTRAT package, under the null hypothesis of "no association between GBM and control SNP genotypes," based on an additive inheritance model. Genes that are strongly correlated with identified SNPs were determined by linkage disequilibrium (LD) or expression quantitative trait locus (eQTL) analysis. A new approach that combines meta-analysis and pathway enrichment analysis identified additional genes.<h4>Results</h4>(i) A meta-analysis of SNP data from TCGA and the Adult Glioma Study identifies 12 predisposing SNP candidates, seven of which are reported for the first time. These SNPs fall in five genomic regions (5p15.33, 9p21.3, 1p21.2, 3q26.2 and 7p15.3), three of which have not been previously reported. (ii) 25 genes are strongly correlated with these 12 SNPs, eight of which are known to be cancer-associated. (iii) The relative risk for GBM is highest for risk allele combinations on chromosomes 1 and 9. (iv) A combined meta-analysis/pathway analysis identified an additional four genes. All of these have been identified as cancer-related, but have not been previously associated with glioma. (v) Some SNPs that do not occur reproducibly across populations are in reproducible (invariant) pathways, suggesting that they affect the same biological process, and that population discordance can be partially resolved by evaluating processes rather than genes.<h4>Conclusion</h4>We have uncovered 29 glioma-associated gene candidates; 12 of them known to be cancer related (p = 1. 4 × 10-6), providing additional statistical support for the relevance of the new candidates. This additional information on risk loci is potentially important for identifying Caucasian individuals at risk for glioma, and for assessing relative risk.
Also flagged:transcription factorsbindingcell surface receptorshematological diseasesleukemiasmyelodysplastic syndromes
Journal Article2011-08-09✓ 1 SnippetLiu P, Barb J, Woodhouse K, Taylor JG, Munson PJ, Raghavachari N.
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Hematopoietic differentiation is strictly regulated by complex network of transcription factors that are controlled by ligands binding to cell surface receptors. Disruptions of the intricate sequences of transcriptional activation and suppression of multiple genes cause hematological diseases, such as leukemias, myelodysplastic syndromes, or myeloproliferative syndromes. From a clinical standpoint, deciphering the pattern of gene expression during hematopoiesis may help unravel disease-specific mechanisms in hematopoietic malignancies. Herein, we describe a human in vitro hematopoietic model system where lineage-specific differentiation of CD34(+) cells was accomplished using specific cytokines. Microarray and RNAseq-based whole transcriptome and exome analysis was performed on the differentiated erythropoietic, granulopoietic, and megakaryopoietic cells to delineate changes in expression of whole transcripts and exons. Analysis on the Human 1.0 ST exon arrays indicated differential expression of 172 genes (P < 0.0000001) and significant alternate splicing of 86 genes during differentiation. Pathway analysis identified these genes to be involved in Rac/RhoA signaling, Wnt/B-catenin signaling and alanine/aspartate metabolism. Comparison of the microarray data to next generation RNAseq analysis during erythroid differentiation demonstrated a high degree of correlation in gene (R = 0.72) and exon (R = 0.62) expression. Our data provide a molecular portrait of events that regulate differentiation of hematopoietic cells. Knowledge of molecular processes by which the cells acquire their cell-specific fate would be beneficial in developing cell-based therapies for human diseases.
Also flagged:15-Lipoxygenase 1phosphatidylethanolamine-binding proteinMAPKEpithelial 15-lipoxygenase 1ERKasthma
Journal Article2011-08-09✓ 5 SnippetsZhao J, O'Donnell VB, Balzar S, St Croix CM, Trudeau JB, Wenzel SE.
In-Text Gene Mentions
Abstract)
…Colocalization of Raf-1 to PEBP1 is low in asthmatic tissue and cells compared with normals, whereas there is striking colocalization of 15LO1 with PEBP1 in asthma.…
Abstract)
…PEBP1 is low in asthmatic tissue and cells compared with normals, whereas there is striking colocalization of 15LO1 with PEBP1 in asthma…
Abstract)
…Raf-1 to PEBP1 is low in asthmatic tissue and cells compared with normals, whereas there is striking colocalization of 15LO1 with PEBP1 in asthma…
Epithelial 15-lipoxygenase 1 (15LO1) and activated ERK are increased in asthma despite modest elevations in IL-13. MAPK kinase (MEK)/ERK activation is regulated by interactions of Raf-1 with phosphatidylethanolamine-binding protein 1 (PEBP1). Epithelial 15LO1 generates intracellular 15-hydroxyeicosatetraenoic acid (15HETE) conjugated to phosphatidylethanolamine (PE) (15HETE-PE). We hypothesized that (i) 15LO1 and its product 15HETE-PE serve as signaling molecules interacting with PEBP1 to activate Raf-1/MEK/ERK and that (ii) this 15LO1-15HETE-PE-regulated ERK activation amplifies IL-4Rα downstream pathways. Our results demonstrate that high epithelial 15LO1 levels correlate with ERK phosphorylation ex vivo. In vitro, IL-13 induces 15LO1, which preferentially binds to PEBP1, causing PEBP1 to dissociate from Raf-1 and activate ERK. Exogenous 15HETE-PE similarly induces dissociation of PEBP1 from Raf-1 independently of IL-13/15LO1. siRNA knockdown of 15LO1 decreases the dissociation of Raf-1 from PEBP1, and the resulting lower ERK activation leads to lower downstream IL-4Rα-related gene expression. Identical protein-protein interactions are observed in endobronchial biopsies and fresh epithelial cells from asthmatics ex vivo. Colocalization of Raf-1 to PEBP1 is low in asthmatic tissue and cells compared with normals, whereas there is striking colocalization of 15LO1 with PEBP1 in asthma. Low 15LO1 levels in normals limit its colocalization with PEBP1. The results confirm a previously unknown signaling role for 15LO1 and its PE-conjugated eicosanoid product in human airway epithelial cells. This pathway enhances critical inflammatory pathways integral to asthma pathogenesis.
Also flagged:ELL2histone H3immunoglobulin heavy chainrich leukemia genetranscription elongation factorsecretion-specific
Journal Article2011-08-09✓ 1 SnippetMilcarek C, Albring M, Langer C, Park KS.
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In plasma cells, immunoglobulin heavy chain (IgH) secretory-specific mRNA is made in high abundance as a result of both increased promoter proximal poly(A) site choice and weak splice-site skipping. Ell2, the eleven-nineteen lysine rich leukemia gene, is a transcription elongation factor that is induced ∼6-fold in plasma cells and has been shown to drive secretory-specific mRNA production. Reducing ELL2 by siRNA, which reduced processing to the secretion-specific poly(A) site, also influenced the methylations of histone H3K4 and H3K79 on the IgH gene and impacted positive transcription factor b (pTEFb), Ser-2 carboxyl-terminal phosphorylation, and polyadenylation factor additions to RNA polymerase II. The multiple lineage leukemia gene (MLL) and Dot1L associations with the IgH gene were also impaired in the absence of ELL2. To investigate the link between histone modifications, transcription elongation, and alternative RNA processing in IgH mRNA production, we performed chromatin immunoprecipitation on cultured mouse B and plasma cells bearing the identical IgH γ2a gene. In the plasma cells, as compared with the B cells, the H3K4 and H3K79 methylations extended farther downstream, past the IgH enhancer to the end of the transcribed region. Thus the downstream H3K4 and H3K79 methylation of the IgH associated chromatin in plasma cells is associated with increased polyadenylation and exon skipping, resulting from the actions of ELL2 transcription elongation factor.
Also flagged:MethionineperoxiredoxinantibodyMSRAtsa1tsa2
Journal Article2011-08-09✓ 4 SnippetsSideri TC, Koloteva-Levine N, Tuite MF, Grant CM.
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…were used forHtt(pYES2-Htt25Q-GFP, pYES2-Htt10…
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…region of theHttgene beyond the…
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…glutamines causes theHttprotein to become…
Discussion)
…Swi1, Cyc8, Ure2,Htt, and α-synuclein in…
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The frequency with which the yeast [PSI(+)] prion form of Sup35 arises de novo is controlled by a number of genetic and environmental factors. We have previously shown that in cells lacking the antioxidant peroxiredoxin proteins Tsa1 and Tsa2, the frequency of de novo formation of [PSI(+)] is greatly elevated. We show here that Tsa1/Tsa2 also function to suppress the formation of the [PIN(+)] prion form of Rnq1. However, although oxidative stress increases the de novo formation of both [PIN(+)] and [PSI(+)], it does not overcome the requirement of cells being [PIN(+)] to form the [PSI(+)] prion. We use an anti-methionine sulfoxide antibody to show that methionine oxidation is elevated in Sup35 during oxidative stress conditions. Abrogating Sup35 methionine oxidation by overexpressing methionine sulfoxide reductase (MSRA) prevents [PSI(+)] formation, indicating that Sup35 oxidation may underlie the switch from a soluble to an aggregated form of Sup35. In contrast, we were unable to detect methionine oxidation of Rnq1, and MSRA overexpression did not affect [PIN(+)] formation in a tsa1 tsa2 mutant. The molecular basis of how yeast and mammalian prions form infectious amyloid-like structures de novo is poorly understood. Our data suggest a causal link between Sup35 protein oxidation and de novo [PSI(+)] prion formation.
Also flagged:protein tyrosine phosphatase-, transmembrane proteinprotein phosphataseExtracellularbinding
Journal Article2011-08-09✓ 1 SnippetChesini IM, Debyser G, Croes H, Ten Dam GB, Devreese B, Stoker AW, Hendriks WJ.
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…contains members likeNeuronal growth regulator 1growth regulator 1,…
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Mouse protein tyrosine phosphatase PTPBR7 is a receptor-like, transmembrane protein that is localized on the surface of neuronal cells. Its protein phosphatase activity is reduced upon multimerization, and PTPBR7-deficient mice display motor coordination defects. Extracellular molecules that may influence PTPBR7 activity, however, remain to be determined. We here show that the PTPBR7 extracellular domain binds to highly myelinated regions in mouse brain, in particular the white matter tracks in cerebellum. PTPBR7 deficiency does not alter this binding pattern, as witnessed by RAP in situ staining of Ptprr⁻/⁻ mouse brain sections. Additional in situ and in vitro experiments also suggest that sugar moieties of heparan sulphate and chondroitin sulphate glycosaminoglycans are not critical for PTPBR7 binding. Candidate binding proteins were affinity-purified exploiting the PTPBR7 extracellular domain and identified by mass spectrometric means. Results support the suggested link between PTPRR isoforms and cerebellar calcium ion homeostasis, and suggest an additional role in the process of cell-cell adhesion.
Also flagged:ironiron overload disordersiron overloadmiscellaneousoxygenmembrane
Journal Article2011-08-09✓ 1 SnippetBrissot P, Ropert M, Le Lan C, Loréal O.
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Abstract)
…iron overload disorders (hemochromatosis, transfusional iron overload)…
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<h4>Background</h4>Besides transferrin iron, which represents the normal form of circulating iron, non-transferrin bound iron (NTBI) has been identified in the plasma of patients with various pathological conditions in which transferrin saturation is significantly elevated.<h4>Scope of the review</h4>To show that: i) NTBI is present not only during chronic iron overload disorders (hemochromatosis, transfusional iron overload) but also in miscellaneous diseases which are not primarily iron overloaded conditions; ii) this iron species represents a potentially toxic iron form due to its high propensity to induce reactive oxygen species and is responsible for cellular damage not only at the plasma membrane level but also towards different intracellular organelles; iii) the NTBI concept may be expanded to include intracytosolic iron forms which are not linked to ferritin, the major storage protein which exerts, at the cellular level, the same type of protective effect towards the intracellular environment as transferrin in the plasma.<h4>Major conclusions</h4>Plasma NTBI and especially labile plasma iron determinations represent a new important biological tool since elimination of this toxic iron species is a major therapeutic goal.<h4>General significance</h4>The NTBI approach represents an important mechanistic concept for explaining cellular iron excess and toxicity and provides new important biochemical diagnostic tools. This article is part of a Special Issue entitled Transferrins: Molecular mechanisms of iron transport and disorders.
Also flagged:ironoxygentransition metalmetabolismHemoglobinprotoporphyrin IX
Journal Article2011-08-09No SnippetsSheftel AD, Mason AB, Ponka P.
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<h4>Background</h4>Not long after the Big Bang, iron began to play a central role in the Universe and soon became mired in the tangle of biochemistry that is the prima essentia of life. Since life's addiction to iron transcends the oxygenation of the Earth's atmosphere, living things must be protected from the potentially dangerous mix of iron and oxygen. The human being possesses grams of this potentially toxic transition metal, which is shuttling through his oxygen-rich humor. Since long before the birth of modern medicine, the blood-vibrant red from a massive abundance of hemoglobin iron-has been a focus for health experts.<h4>Scope of review</h4>We describe the current understanding of iron metabolism, highlight the many important discoveries that accreted this knowledge, and describe the perils of dysfunctional iron handling.<h4>General significance</h4>Isaac Newton famously penned, "If I have seen further than others, it is by standing upon the shoulders of giants". We hope that this review will inspire future scientists to develop intellectual pursuits by understanding the research and ideas from many remarkable thinkers of the past.<h4>Major conclusions</h4>The history of iron research is a long, rich story with early beginnings, and is far from being finished. This article is part of a Special Issue entitled Transferrins: Molecular mechanisms of iron transport and disorders.
Also flagged:depressionphotontechnetiumhexamethylpropyleneaminepsychiatric disorder
Journal Article2011-08-09✓ 2 SnippetsWilleumier K, Taylor DV, Amen DG.
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Discussion)
…Post-mortem studies of suicide patients found decreased 5-hydroxytryptamine (5-HT1A)/5-HT2A receptor binding in the ventrolateral prefrontal cortex, spurring in vivo imaging work in this area.16 SPECT imaging studies have confirmed reduced binding of 5-HT2Aa receptors in the frontal lobes of suicide attempters17, 18 and decreased serotonin transporter availability in suicide attempters with 5-HTT polymorphisms19 indicative of serotonin abnormalities playing a role in suicide risk.…
Suicide has a high comorbidity with impulsivity and depression, and finding imaging biomarkers indicative of patients at high risk for suicidal behavior is invaluable to the clinician. Using single-photon emission computed tomography (SPECT) imaging, we have previously reported regional cerebral blood flow (rCBF) decreases in the medial prefrontal cortex, ventral tegmental area and subgenual cingulate cortex (Brodmann area 25 (BA 25)), a region found to be hypoperfused with treatment-resistant depression. From 2007 to 2010, we have extended our analysis to include nine additional completed suicides. In all, 27 healthy, age- and gender-matched subjects from a previously acquired healthy brain study served as controls to our 21 completed suicides. All 21 suicides had been previously diagnosed with depression according to Diagnostic and Statistical Manual of Mental Disorder-IV criterion. Voxel-by-voxel analyses were performed using statistical parametric mapping to compare the differences in technetium-99m hexamethylpropylene amine oxime brain uptake between the groups. Factor analysis of the data identified the top 10 regions of hypoperfusion in the suicidal group, including the bilateral superior frontal lobes, the right precuneus, the rolandic operculum, postcentral gyrus, left caudate and insular cortex. We also demonstrate more focal decreases in rCBF in the subgenual cingulate cortex (BA 25) in 18 subjects, supporting our previous hypothesis that hypoperfusion of BA 25 may be a risk factor for suicide in depressed patients. This work suggests that SPECT might be useful in predicting risk for suicide completion in subjects with depression or treatment-resistant depression. Further investigation of this work is necessary to better understand the predictive value of this finding.
Also flagged:gene expressionSjögren's syndromeautoimmune diseasemetabolismneurogenesischronic autoimmune disease
Journal Article2011-08-08No SnippetsMichael D, Soi S, Cabera-Perez J, Weller M, Alexander S, Alevizos I, Illei G, Chiorini J.
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<h4>Objective</h4>We hypothesized that differential mRNA transcription between the sexes may be linked to the 9:1 female-to-male gender-related relative risk for the development of Sjögren's syndrome (SS), an autoimmune disease that leads to inflammation and dysfunction in the lachrymal and salivary glands.<h4>Subjects and methods</h4>RNA from minor salivary glands was collected from nine healthy volunteers (four men and five women) and analyzed using the Agilent 4 × 44K human microarray platform. Differential expression was confirmed by qRT-PCR.<h4>Results</h4>Comparison of the transcriptome of minor salivary glands from normal male and female volunteers with that of salivary glands and secretory epithelia identified a number of gender, species, and tissue-specific gene expression patterns. These differences include, but are not limited to, a diverse set of genes involved in immune modulation, chemotactic control, inhibition of complement, metabolism, and neurogenesis.<h4>Conclusion</h4>Analysis of these changes provides insight into the protective and predisposing molecular factors that may be involved in the development of Sjögren's syndrome. Some of the gene changes observed in this study correlate with previously observed sexual dimorphisms in salivary gland function and also illustrate several new targets for further investigation.
Also flagged:cocainemorphinephencyclidineschizophreniadegenerative CNS diseasebehavioral
Journal Article2011-08-08✓ 1 SnippetCahill H, Rattner A, Nathans J.
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The drug development process for CNS indications is hampered by a paucity of preclinical tests that accurately predict drug efficacy in humans. Here, we show that a wide variety of CNS-active drugs induce characteristic alterations in visual stimulus-induced and/or spontaneous eye movements in mice. Active compounds included sedatives and antipsychotic, antidepressant, and antiseizure drugs as well as drugs of abuse, such as cocaine, morphine, and phencyclidine. The use of quantitative eye-movement analysis was demonstrated by comparing it with the commonly used rotarod test of motor coordination and by using eye movements to monitor pharmacokinetics, blood-brain barrier penetration, drug-receptor interactions, heavy metal toxicity, pharmacologic treatment in a model of schizophrenia, and degenerative CNS disease. We conclude that eye-movement analysis could complement existing animal tests to improve preclinical drug development.
Also flagged:intellectual disabilityIDgene expressionCHD1LALC1chromatin
Journal Article2011-08-08✓ 5 SnippetsHarvard C, Strong E, Mercier E, Colnaghi R, Alcantara D, Chow E, Martell S, Tyson C, Hrynchak M, McGillivray B, Hamilton S, Marles S, Mhanni A, Dawson AJ, Pavlidis P, Qiao Y, Holden JJ, Lewis SM, O'Driscoll M, Rajcan-Separovic E.
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…It is possible that in cell lines with 1q21.1 Del and Dup the DCC defect is not accompanied with other deleterious events and thus the threshold for significant spontaneous genomic instability leading to premature cell senescence/cancer predisposition is not met.…
Results)
…Interestingly, we found that LBCs carrying a Del or Dup of 1q21.1 failed to arrest in G2 following Topo II inhibition, and instead, exhibited elevated pseudomitosis similar to WRN-defective cells from a patient with Werner syndrome (OMIM #277700, Figure 3D), which are known to exhibit defective DCC activation [29].…
Discussion)
…Previous DCC studies of Werner syndrome and control cells suggested that DCC defect per se is not sufficient to cause significant genomic instability, but requires absence or dysfunction of "caretaker" genes such as ATR, BRCA1 or WRN [29].…
Discussion)
…It is of interest that the DCC defect detected in the 1q21.1 Del and Dup containing cell lines is comparable to that seen in cells from Werner syndrome (OMIM 277700), an autosomal recessive disorder, associated with predisposition to cancer and premature aging, neither of which were noted in our patients.…
Abstract)
…of CHD1L/ALC1 inDCC.…
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<h4>Background</h4>1q21.1 Copy Number Variant (CNV) is associated with a highly variable phenotype ranging from congenital anomalies, learning deficits/intellectual disability (ID), to a normal phenotype. Hence, the clinical significance of this CNV can be difficult to evaluate. Here we described the consequences of the 1q21.1 CNV on genome-wide gene expression and function of selected candidate genes within 1q21.1 using cell lines from clinically well described subjects.<h4>Methods and results</h4>Eight subjects from 3 families were included in the study: six with a 1q21.1 deletion and two with a 1q21.1 duplication. High resolution Affymetrix 2.7M array was used to refine the 1q21.1 CNV breakpoints and exclude the presence of secondary CNVs of pathogenic relevance. Whole genome expression profiling, studied in lymphoblast cell lines (LBCs) from 5 subjects, showed enrichment of genes from 1q21.1 in the top 100 genes ranked based on correlation of expression with 1q21.1 copy number. The function of two top genes from 1q21.1, CHD1L/ALC1 and PRKAB2, was studied in detail in LBCs from a deletion and a duplication carrier. CHD1L/ALC1 is an enzyme with a role in chromatin modification and DNA damage response while PRKAB2 is a member of the AMP kinase complex, which senses and maintains systemic and cellular energy balance. The protein levels for CHD1L/ALC1 and PRKAB2 were changed in concordance with their copy number in both LBCs. A defect in chromatin remodeling was documented based on impaired decatenation (chromatid untangling) checkpoint (DCC) in both LBCs. This defect, reproduced by CHD1L/ALC1 siRNA, identifies a new role of CHD1L/ALC1 in DCC. Both LBCs also showed elevated levels of micronuclei following treatment with a Topoisomerase II inhibitor suggesting increased DNA breaks. AMP kinase function, specifically in the deletion containing LBCs, was attenuated.<h4>Conclusion</h4>Our studies are unique as they show for the first time that the 1q21.1 CNV not only causes changes in the expression of its key integral genes, associated with changes at the protein level, but also results in changes in their known function, in the case of AMPK, and newly identified function such as DCC activation in the case of CHD1L/ALC1. Our results support the use of patient lymphoblasts for dissecting the functional sequelae of genes integral to CNVs in carrier cell lines, ultimately enhancing understanding of biological processes which may contribute to the clinical phenotype.
<h4>Background</h4>There are large differences between the sexes at the genetic level; these differences include heterogametic sex chromosomes and/or differences in expression of genes between the sexes. In rainbow trout (Oncorhynchus mykiss) qRT-PCR studies have found significant differences in expression of several candidate sex determining genes. However, these genes represent a very small fraction of the genome and research in other species suggests there are large portions of the transcriptome that are differentially expressed between the sexes. These differences are especially noticeable once gonad differentiation and maturation has occurred, but less is known at earlier stages of development. Here we use data from a microarray and qRT-PCR to identify genes differentially expressed between the sexes at three time points in pre-hatch embryos, prior to the known timing of sexual differentiation in this species.<h4>Results</h4>The microarray study revealed 883 differentially expressed features between the sexes with roughly equal numbers of male and female upregulated features across time points. Most of the differentially expressed genes on the microarray were not related to sex function, suggesting large scale differences in gene expression between the sexes are present early in development. Candidate gene analysis revealed sox9, DMRT1, Nr5a1 and wt1 were upregulated in males at some time points and foxl2, ovol1, fst and cyp19a1a were upregulated in females at some time points.<h4>Conclusion</h4>This is the first study to identify sexual dimorphism in expression of the genome during embryogenesis in any fish and demonstrates that transcriptional differences are present before the completion of gonadogenesis.
To better understand the biology of hormone receptor-positive and-negative breast cancer and to identify methylated gene markers of disease progression, we carried out a genome-wide methylation array analysis on 103 primary invasive breast cancers and 21 normal breast samples, using the Illumina Infinium HumanMethylation27 array that queried 27,578 CpG loci. Estrogen and/or progesterone receptor-positive tumors displayed more hypermethylated loci than estrogen receptor (ER)-negative tumors. However, the hypermethylated loci in ER-negative tumors were clustered closer to the transcriptional start site compared with ER-positive tumors. An ER-classifier set of CpG loci was identified, which independently partitioned primary tumors into ER subtypes. A total of 40 (32 novel and 8 previously known) CpG loci showed differential methylation specific to either ER-positive or ER-negative tumors. Each of the 40 ER subtype-specific loci was validated in silico, using an independent, publicly available methylome dataset from the Cancer Genome Atlas. In addition, we identified 100 methylated CpG loci that were significantly associated with disease progression; the majority of these loci were informative particularly in ER-negative breast cancer. Overall, the set was highly enriched in homeobox containing genes. This pilot study shows the robustness of the breast cancer methylome and illustrates its potential to stratify and reveal biological differences between ER subtypes of breast cancer. Furthermore, it defines candidate ER-specific markers and identifies potential markers predictive of outcome within ER subgroups.
The synovial joint contains synovial fluid (SF) within a cavity bounded by articular cartilage and synovium. SF is a viscous fluid that has lubrication, metabolic, and regulatory functions within synovial joints. SF contains lubricant molecules, including proteoglycan-4 and hyaluronan. SF is an ultrafiltrate of plasma with secreted contributions from cell populations lining and within the synovial joint space, including chondrocytes and synoviocytes. Maintenance of normal SF lubricant composition and function are important for joint homeostasis. In osteoarthritis, rheumatoid arthritis, and joint injury, changes in lubricant composition and function accompany alterations in the cytokine and growth factor environment and increased fluid and molecular transport through joint tissues. Thus, understanding the synovial joint lubrication system requires a multifaceted study of the various parts of the synovial joint and their interactions. Systems biology approaches at multiple scales are being used to describe the molecular, cellular, and tissue components and their interactions that comprise the functioning synovial joint. Analyses of the transcriptome and proteome of SF, cartilage, and synovium suggest that particular molecules and pathways play important roles in joint homeostasis and disease. Such information may be integrated with physicochemical tissue descriptions to construct integrative models of the synovial joint that ultimately may explain maintenance of health, recovery from injury, or development and progression of arthritis.
Also flagged:Ten-modzaxongrowth conesFilaminactin binding protein
Journal Article2011-08-08✓ 1 SnippetZheng L, Michelson Y, Freger V, Avraham Z, Venken KJ, Bellen HJ, Justice MJ, Wides R.
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…DCC/frazzled (deleted in colorect…
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The Drosophila Ten-m (also called Tenascin-major, or odd Oz (odz)) gene has been associated with a pair-rule phenotype. We identified and characterized new alleles of Drosophila Ten-m to establish that this gene is not responsible for segmentation defects but rather causes defects in motor neuron axon routing. In Ten-m mutants the inter-segmental nerve (ISN) often crosses segment boundaries and fasciculates with the ISN in the adjacent segment. Ten-m is expressed in the central nervous system and epidermal stripes during the stages when the growth cones of the neurons that form the ISN navigate to their targets. Over-expression of Ten-m in epidermal cells also leads to ISN misrouting. We also found that Filamin, an actin binding protein, physically interacts with the Ten-m protein. Mutations in cheerio, which encodes Filamin, cause defects in motor neuron axon routing like those of Ten-m. During embryonic development, the expression of Filamin and Ten-m partially overlap in ectodermal cells. These results suggest that Ten-m and Filamin in epidermal cells might together influence growth cone progression.
Also flagged:immune responsescell growthcell cycledeathinflammatory responsecytokine
Journal Article2011-08-07No SnippetsMirza N, Pollock K, Hoelzinger DB, Dominguez AL, Lustgarten J.
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It is well established that immune responses are diminished in the old. However, we still do not have a clear understanding of what dictates the dysfunction of old T cells at the molecular level. Although microarray analysis has been used to compare young and old T cells, identifying hundreds of genes that are differentially expressed among these populations, it has been difficult to utilize this information to pinpoint which biological pathways truly affect the function of aged T cells. To better define differences between young and old naïve CD4+ and CD8+ T cells, microarray analysis was performed pre- and post-TCR stimulation for 4, 12, 24 and 72 h. Our data indicate that many genes are differentially expressed in the old compared to the young at all five time points. These genes encode proteins involved in multiple cellular functions such as cell growth, cell cycle, cell death, inflammatory response, cell trafficking, etc. Additionally, the information from this microarray analysis allowed us to underline both intrinsic deficiencies and defects in signaling only seen after activation, such as pathways involving T-cell signaling, cytokine production, and Th2 differentiation in old T cells. With the knowledge gained, we can proceed to design strategies to restore the function of old T cells. Therefore, this microarray analysis approach is a powerful and sensitive tool that reveals the extensive changes seen between young and old CD4+ and CD8+ naïve T cells. Evaluation of these differences provides in-depth insight into potential functional and phenotypical differences among these populations.
Also flagged:RESTHIPPIhuntingtin interacting protein 1HIP1caspase-1RE1-silencing transcription factor/
Journal Article2011-08-06✓ 1 SnippetDatta M, Bhattacharyya NP.
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Earlier we have shown that the proapoptotic protein HIPPI (huntingtin interacting protein 1 (HIP1) protein interactor) along with its molecular partner HIP1 could regulate transcription of the caspase-1 gene. Here we report that RE1-silencing transcription factor/neuron-restrictive silencer factor (REST/NRSF) is a new transcriptional target of HIPPI. HIPPI could bind to the promoter of REST and increased its expression in neuronal as well as non-neuronal cells. Such activation of REST down-regulated expression of REST target genes, such as brain-derived neurotrophic factor (BDNF) or proenkephalin (PENK). The ability of HIPPI to activate REST gene transcription was dependent on HIP1, the nuclear transporter of HIPPI. Using a Huntington disease cell model, we have demonstrated that feeble interaction of HIP1 with mutant huntingtin protein resulted in increased nuclear accumulation of HIPPI and HIP1, leading to higher occupancy of HIPPI at the REST promoter, triggering its transcriptional activation and consequent repression of REST target genes. This novel transcription regulatory mechanism of REST by HIPPI may contribute to the deregulation of transcription observed in the cell model of Huntington disease.
Also flagged:mental illnesslipidlipoproteincholesteroltriglyceridesobesity
Journal Article2011-08-06No SnippetsWindemuth A, de Leon J, Goethe JW, Schwartz HI, Woolley S, Susce M, Kocherla M, Bogaard K, Holford TR, Seip RL, Ruaño G.
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The purpose of this study was to identify genetic variants predictive of cardiovascular risk factors in a psychiatric population treated with second generation antipsychotics (SGA). 924 patients undergoing treatment for severe mental illness at four US hospitals were genotyped at 1.2 million single nucleotide polymorphisms. Patients were assessed for fasting serum lipid (low density lipoprotein cholesterol [LDLc], high density lipoprotein cholesterol [HDLc], and triglycerides) and obesity phenotypes (body mass index, BMI). Thirteen candidate genes from previous studies of the same phenotypes in non-psychiatric populations were tested for association. We confirmed 8 of the 13 candidate genes at the 95% confidence level. An increased genetic effect size was observed for triglycerides in the psychiatric population compared to that in the cardiovascular population.
Also flagged:breast canceraxon guidance moleculescell proliferationtumoroncogenesNetrin
Journal Article2011-08-05✓ 1 SnippetHarburg GC, Hinck L.
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Slit, Netrin, Ephrin, and Semaphorin's roles in development have expanded greatly in the past decade from their original characterization as axon guidance molecules (AGMs) to include roles as regulators of tissue morphogenesis and development in diverse organs. In the mammary gland, AGMs are important for maintaining normal cell proliferation and adhesion during development. The frequent dysregulation of AGM expression during tumorigenesis and tumor progression suggests that AGMs also play a crucial role as tumor suppressors and oncogenes in breast cancer. Moreover, these findings suggest that AGMs may be excellent targets for new breast cancer prognostic tests and more effective therapeutic strategies.
Also flagged:primary cardiomyopathiesrestrictive cardiomyopathysarcomeredilated cardiomyopathiescardiomyopathiesof the
Journal Article2011-08-05✓ 1 SnippetCaleshu C, Sakhuja R, Nussbaum RL, Schiller NB, Ursell PC, Eng C, De Marco T, McGlothlin D, Burchard EG, Rame JE.
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Mutations in genes that encode components of the sarcomere are well established as the cause of hypertrophic and dilated cardiomyopathies. Sarcomere genes, however, are increasingly being associated with other cardiomyopathies. One phenotype more recently recognized as a disease of the sarcomere is restrictive cardiomyopathy (RCM). We report on two patients with RCM associated with multiple mutations in sarcomere genes not previously associated with RCM. Patient 1 presented with NYHA Class III/IV heart failure at 22 years of age. She was diagnosed with RCM and advanced heart failure requiring heart transplantation. Sequencing of sarcomere genes revealed previously reported homozygous p.Glu143Lys mutations in MYL3, and a novel heterozygous p.Gly57Glu mutation in MYL2. The patient's mother is a double heterozygote for these mutations, with no evidence of cardiomyopathy. Patient 2 presented at 35 years of age with volume overload while hospitalized for oophorectomy. She was diagnosed with RCM and is being evaluated for heart transplantation. Sarcomere gene sequencing identified homozygous p.Asn279His mutations in TPM1. The patient's parents are consanguineous and confirmed heterozygotes. Her father was diagnosed with HCM at 42 years of age. This is the first report of mutations in TPM1, MYL3, and MYL2 associated with primary, non-hypertrophied RCM. The association of more sarcomere genes with RCM provides further evidence that mutations in the various sarcomere genes can cause different cardiomyopathy phenotypes. These cases also contribute to the growing body of evidence that multiple mutations have an additive effect on the severity of cardiomyopathies.
Also flagged:BRMS1chromatinSIN3HDACgene expressionNFκB
Journal Article2011-08-05✓ 1 SnippetHurst DR, Welch DR.
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Expression of BRMS1 causes dramatic suppression of metastasis in multiple in vivo model systems. As we gain further insight into the biochemical mechanisms of BRMS1, we appreciate the importance of both molecular and cellular context for functional metastasis suppression. BRMS1 associates with large chromatin remodeling complexes including SIN3:HDAC which are powerful epigenetic regulators of gene expression. Additionally, BRMS1 inhibits the activity of NFκB, a well-known transcription factor that plays significant roles in tumor progression. Moreover, BRMS1 coordinately regulates the expression of metastasis-associated microRNA known as metastamir. How these biochemical mechanisms and biological pathways are linked, either directly or indirectly, and the influence of molecular and cellular context, are critical considerations for the discovery of novel therapeutic targets for the most deadly aspect of tumor progression-metastasis.
Also flagged:receptorHuntington diseaseHDHAP1AMPA receptorAMPAR
Journal Article2011-08-05✓ 5 SnippetsMandal M, Wei J, Zhong P, Cheng J, Duffney LJ, Liu W, Yuen EY, Twelvetrees AE, Li S, Li XJ, Kittler JT, Yan Z.
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Abstract)
…Emerging evidence from studies of Huntington disease (HD) pathophysiology suggests that huntingtin (htt) and its associated protein HAP1 participate in intracellular trafficking and synaptic function.…
Abstract)
…suggests that huntingtin (htt) and its associated…
Abstract)
…olyglutamine expansion (polyQ-htt).…
Abstract)
…found that expressing polyQ-httin neuronal cultures…
Emerging evidence from studies of Huntington disease (HD) pathophysiology suggests that huntingtin (htt) and its associated protein HAP1 participate in intracellular trafficking and synaptic function. However, it is largely unknown whether AMPA receptor trafficking, which is crucial for controlling the efficacy of synaptic excitation, is affected by the mutant huntingtin with polyglutamine expansion (polyQ-htt). In this study, we found that expressing polyQ-htt in neuronal cultures significantly decreased the amplitude and frequency of AMPAR-mediated miniature excitatory postsynaptic current (mEPSC), while expressing wild-type huntingtin (WT-htt) increased mEPSC. AMPAR-mediated synaptic transmission was also impaired in a transgenic mouse model of HD expressing polyQ-htt. The effect of polyQ-htt on mEPSC was mimicked by knockdown of HAP1 and occluded by the dominant negative HAP1. Moreover, we found that huntingtin affected mESPC via a mechanism depending on the kinesin motor protein, KIF5, which controls the transport of GluR2-containing AMPARs along microtubules in dendrites. The GluR2/KIF5/HAP1 complex was disrupted and dissociated from microtubules in the HD mouse model. Together, these data suggest that AMPAR trafficking and function is impaired by mutant huntingtin, presumably due to the interference of KIF5-mediated microtubule-based transport of AMPA receptors. The diminished strength of glutamatergic transmission could contribute to the deficits in movement control and cognitive processes in HD conditions.
Also flagged:metalloreductaseironmetalloreductasesMRferrireductasesmetabolism
Journal Article2011-08-05No SnippetsBlatzer M, Binder U, Haas H.
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Aspergillus fumigatus employs two high affinity iron uptake mechanisms, siderophore mediated iron uptake and reductive iron assimilation (RIA). The A. fumigatus genome encodes 15 putative metalloreductases (MR) but the ferrireductases involved in RIA remained elusive so far. Expression of the MR FreB was found to be transcriptionally repressed by iron via SreA, a repressor of iron acquisition during iron sufficiency, indicating a role in iron metabolism. FreB-inactivation by gene deletion was phenotypically largely inconspicuous unless combined with inactivation of the siderophore system, which then decreased growth rate, surface ferrireductase activity and oxidative stress resistance during iron starvation. This study also revealed that loss of copper-independent siderophore-mediated iron uptake increases sensitivity of A. fumigatus to copper starvation due to copper-dependence of RIA.
Also flagged:amino acidamino acidsprotein synthesisazidealkynealkene
Journal Article2011-08-04No SnippetsNgo JT, Tirrell DA.
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Proteins in living cells can be made receptive to bioorthogonal chemistries through metabolic labeling with appropriately designed noncanonical amino acids (ncAAs). In the simplest approach to metabolic labeling, an amino acid analog replaces one of the natural amino acids specified by the protein's gene (or genes) of interest. Through manipulation of experimental conditions, the extent of the replacement can be adjusted. This approach, often termed residue-specific incorporation, allows the ncAA to be incorporated in controlled proportions into positions normally occupied by the natural amino acid residue. For a protein to be labeled in this way with an ncAA, it must fulfill just two requirements: (i) the corresponding natural amino acid must be encoded within the sequence of the protein at the genetic level, and (ii) the protein must be expressed while the ncAA is in the cell. Because this approach permits labeling of proteins throughout the cell, it has enabled us to develop strategies to track cellular protein synthesis by tagging proteins with reactive ncAAs. In procedures similar to isotopic labeling, translationally active ncAAs are incorporated into proteins during a "pulse" in which newly synthesized proteins are tagged. The set of tagged proteins can be distinguished from those made before the pulse by bioorthogonally ligating the ncAA side chain to probes that permit detection, isolation, and visualization of the labeled proteins. Noncanonical amino acids with side chains containing azide, alkyne, or alkene groups have been especially useful in experiments of this kind. They have been incorporated into proteins in the form of methionine analogs that are substrates for the natural translational machinery. The selectivity of the method can be enhanced through the use of mutant aminoacyl tRNA synthetases (aaRSs) that permit incorporation of ncAAs not used by the endogenous biomachinery. Through expression of mutant aaRSs, proteins can be tagged with other useful ncAAs, including analogs that contain ketones or aryl halides. High-throughput screening strategies can identify aaRS variants that activate a wide range of ncAAs. Controlled expression of mutant synthetases has been combined with ncAA tagging to permit cell-selective metabolic labeling of proteins. Expression of a mutant synthetase in a portion of cells within a complex cellular mixture restricts labeling to that subset of cells. Proteins synthesized in cells not expressing the synthetase are neither labeled nor detected. In multicellular environments, this approach permits the identification of the cellular origins of labeled proteins. In this Account, we summarize the tools and strategies that have been developed for interrogating cellular protein synthesis through residue-specific tagging with ncAAs. We describe the chemical and genetic components of ncAA-tagging strategies and discuss how these methods are being used in chemical biology.
The estrogen sulfotransferase (EST) is a phase II drug-metabolizing enzyme known to catalyze the sulfoconjugation of estrogens. EST is highly expressed in the white adipose tissue of male mice, but the role of EST in the development and function of adipocytes remains largely unknown. In this report, we showed that EST played an important role in adipocyte differentiation. EST was highly expressed in 3T3-L1 preadipocytes and primary mouse preadipocytes. The expression of EST was dramatically reduced in differentiated 3T3-L1 cells and mature primary adipocytes. Overexpression of EST in 3T3-L1 cells prevented adipocyte differentiation. In contrast, preadipocytes isolated from EST knockout (EST-/-) mice exhibited enhanced differentiation. The inhibitory effect of EST on adipogenesis likely resulted from the sustained activation of ERK1/2 MAPK and inhibition of insulin signaling, leading to a failure of switch from clonal expansion to differentiation. The enzymatic activity of EST was required for the inhibitory effect of EST on adipogenesis, because an enzyme-dead EST mutant failed to inhibit adipocyte differentiation. In vivo, overexpression of EST in the adipose tissue of female transgenic mice resulted in smaller adipocyte size. Taken together, our results suggest that EST functions as a negative regulator of adipogenesis.
Current advances in our understanding of stem and precursor cell biology and in the protocols of stem cell isolation and transplantation have opened up the possibility of transplanting neural stem cells for the treatment of gastrointestinal motility disorders. This review summarises the current status of research in this field, identifies the major gaps in our knowledge and discusses the potential opportunities and hurdles for clinical application.
…In conclusion, our results demonstrate that Hfe(-/-) mice show defective hepatic-intestinal iron and lipid signaling, which predispose them toward diet-induced hepatic lipotoxicity, accompanied by an accelerated progression of injury to fibrosis.…
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…Altered lipid metabolism in Hfe-knockout mice promotes severe NAFLD and early fibrosis.…
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…Here, we investigated the potential contribution of HFE mutations to hepatic lipid metabolism and its role in the pathogenesis of nonalcoholic fatty liver disease.…
The HFE protein plays a crucial role in the control of cellular iron homeostasis. Steatosis is commonly observed in HFE-related iron-overload disorders, and current evidence suggests a causal link between iron and steatosis. Here, we investigated the potential contribution of HFE mutations to hepatic lipid metabolism and its role in the pathogenesis of nonalcoholic fatty liver disease. Wild-type (WT) and Hfe knockout mice (Hfe(-/-)) were fed either standard chow, a monounsaturated low fat, or a high-fat, high-carbohydrate diet (HFD) and assessed for liver injury, body iron status, and markers of lipid metabolism. Despite hepatic iron concentrations and body weights similar to WT controls, Hfe(-/-) mice fed the HFD developed severe hypoxia-related steatohepatitis, Tnf-α activation, and mitochondrial respiratory complex and antioxidant dysfunction with early fibrogenesis. These features were associated with an upregulation in the expression of genes involved in intracellular lipid synthesis and trafficking, while transcripts for mitochondrial fatty acid β-oxidation and adiponectin signaling-related genes were significantly attenuated. In contrast, HFD-fed WT mice developed bland steatosis only, with no inflammation or fibrosis and no upregulation of lipogenesis-related genes. A HFD led to reduced hepatic iron in Hfe(-/-) mice compared with chow-fed mice, despite higher serum iron, decreased hepcidin expression, and increased duodenal ferroportin mRNA. In conclusion, our results demonstrate that Hfe(-/-) mice show defective hepatic-intestinal iron and lipid signaling, which predispose them toward diet-induced hepatic lipotoxicity, accompanied by an accelerated progression of injury to fibrosis.
Also flagged:cancerdeathtumorbreast cancergene expressionsgene expression
Journal Article2011-08-04No SnippetsLin X, Cai T, Wu MC, Zhou Q, Liu G, Christiani DC, Lin X.
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In this article, we develop a powerful test for identifying single nucleotide polymorphism (SNP)-sets that are predictive of survival with data from genome-wide association studies. We first group typed SNPs into SNP-sets based on genomic features and then apply a score test to assess the overall effect of each SNP-set on the survival outcome through a kernel machine Cox regression framework. This approach uses genetic information from all SNPs in the SNP-set simultaneously and accounts for linkage disequilibrium (LD), leading to a powerful test with reduced degrees of freedom when the typed SNPs are in LD with each other. This type of test also has the advantage of capturing the potentially nonlinear effects of the SNPs, SNP-SNP interactions (epistasis), and the joint effects of multiple causal variants. By simulating SNP data based on the LD structure of real genes from the HapMap project, we demonstrate that our proposed test is more powerful than the standard single SNP minimum P-value-based test for association studies with censored survival outcomes. We illustrate the proposed test with a real data application.
Also flagged:posttraumatic stress disorderPTSDserotonin transporterSLC6A4serotonininsomnia
Journal Article2011-08-04✓ 5 SnippetsWang Z, Baker DG, Harrer J, Hamner M, Price M, Amstadter A.
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Abstract)
…The serotonin transporter (5-HTT) gene (SLC6A4) has been identified as a prime candidate for the development of the disorder, as 5-HTT is a working target for selective serotonin reuptake inhibitors (SSRIs), first line treatment agents for PTSD.…
…reported associations between5-HTT-linked promoter region (5-HTT…
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<h4>Background</h4>Empirical evidence suggests that there is a significant genetic influence in the development of posttraumatic stress disorder (PTSD). The serotonin transporter (5-HTT) gene (SLC6A4) has been identified as a prime candidate for the development of the disorder, as 5-HTT is a working target for selective serotonin reuptake inhibitors (SSRIs), first line treatment agents for PTSD. Several studies have reported associations between 5-HTT-linked promoter region (5-HTTLPR) polymorphism variants and increased rates of PTSD in civilian samples. This study investigated the role of the 5-HTTLPR polymorphism, triallelically classified, in a sample of combat veterans with and without PTSD.<h4>Methods</h4>Rates of PTSD were examined across three genotypes in a sample of 388 combat veterans. The short/long polymorphism of 5-HTTLPR and the A-G polymorphism within the 5-HTTLPR (rs25531) were genotyped, and statistical analyses were conducted.<h4>Results</h4>There were significant intergroup (PTSD versus non-PTSD) differences in the genotype frequencies of 5-HTTLPR/rs25531 (χ(2) [1, n = 388] = 16.23, P = 5.62 × 10(-5) ). The 5-HTTLPR S'/S' (low transcriptionally efficient) genotype was also associated with the PTSD severity score in the 228 participants who had combat severity data (r = .15, P = 0.03).<h4>Conclusions</h4>The findings are consistent with previous research among civilian populations that have indicated that the low transcriptionally efficient S'/S' genotype of 5-HTTLPR is a risk factor for the development of PTSD after trauma exposure. Our findings are the first to examine this polymorphism and PTSD in a military sample. Additional large-scale investigations are needed to replicate these findings.
Also flagged:immunoglobulinA deficiencyprimary immunodeficiencyautoimmune diseasesGraves diseasesystemic lupus erythematosus
Journal Article2011-08-04✓ 1 SnippetWang N, Shen N, Vyse TJ, Anand V, Gunnarson I, Sturfelt G, Rantapää-Dahlqvist S, Elvin K, Truedsson L, Andersson BA, Dahle C, Ortqvist E, Gregersen PK, Behrens TW, Hammarström L.
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Selective immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. It has previously been suggested to be associated with a variety of concomitant autoimmune diseases. In this review, we present data on the prevalence of IgAD in patients with Graves disease (GD), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), celiac disease (CD), myasthenia gravis (MG) and rheumatoid arthritis (RA) on the basis of both our own recent large-scale screening results and literature data. Genetic factors are important for the development of both IgAD and various autoimmune disorders, including GD, SLE, T1D, CD, MG and RA, and a strong association with the major histocompatibility complex (MHC) region has been reported. In addition, non-MHC genes, such as interferon-induced helicase 1 (IFIH1) and c-type lectin domain family 16, member A (CLEC16A), are also associated with the development of IgAD and some of the above diseases. This indicates a possible common genetic background. In this review, we present suggestive evidence for a shared genetic predisposition between these disorders.
Also flagged:androgen receptorandrogensprostate cancerPCatumormetastatic disease
Journal Article2011-08-04No SnippetsMarques RB, Dits NF, Erkens-Schulze S, van Ijcken WF, van Weerden WM, Jenster G.
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<h4>Background</h4>Prostate epithelial cells depend on androgens for survival and function. In (early) prostate cancer (PCa) androgens also regulate tumor growth, which is exploited by hormonal therapies in metastatic disease. The aim of the present study was to characterize the androgen receptor (AR) response in hormonal therapy-resistant PC346 cells and identify potential disease markers.<h4>Methodology/principal findings</h4>Human 19K oligoarrays were used to establish the androgen-regulated expression profile of androgen-responsive PC346C cells and its derivative therapy-resistant sublines: PC346DCC (vestigial AR levels), PC346Flu1 (AR overexpression) and PC346Flu2 (T877A AR mutation). In total, 107 transcripts were differentially-expressed in PC346C and derivatives after R1881 or hydroxyflutamide stimulations. The AR-regulated expression profiles reflected the AR modifications of respective therapy-resistant sublines: AR overexpression resulted in stronger and broader transcriptional response to R1881 stimulation, AR down-regulation correlated with deficient response of AR-target genes and the T877A mutation resulted in transcriptional response to both R1881 and hydroxyflutamide. This AR-target signature was linked to multiple publicly available cell line and tumor derived PCa databases, revealing that distinct functional clusters were differentially modulated during PCa progression. Differentiation and secretory functions were up-regulated in primary PCa but repressed in metastasis, whereas proliferation, cytoskeletal remodeling and adhesion were overexpressed in metastasis. Finally, the androgen-regulated genes ENDOD1, MCCC2 and ACSL3 were selected as potential disease markers for RT-PCR quantification in a distinct set of human prostate specimens. ENDOD1 and ACSL3 showed down-regulation in high-grade and metastatic PCa, while MCCC2 was overexpressed in low-grade PCa.<h4>Conclusions/significance</h4>AR modifications altered the transcriptional response to (anti)androgens in therapy-resistant cells. Furthermore, selective down-regulation of genes involved in differentiation and up-regulation of genes promoting proliferation and invasion suggest a disturbed balance between the growth and differentiation functions of the AR pathway during PCa progression. These findings may have implications in the current treatment and development of novel therapeutical approaches for metastatic PCa.
Also flagged:vaccinia-related kinasesVRK1Ser-Thr kinasescell cycleautophagymitogen activated protein kinases
Journal Article2011-08-04✓ 5 SnippetsVázquez-Cedeira M, Barcia-Sanjurjo I, Sanz-García M, Barcia R, Lazo PA.
In-Text Gene Mentions
Introduction)
…VRK1 is a nuclear kinase [13], [19], while VRK2 has two isoforms, a full-length protein of 508 aminoacids (known as VRK2 and VRK2A) [13], which is anchored to cytosolic organelle membranes, such as endoplasmic reticulum and mitochondria by its C-terminal hydrophobic anchoring region [22]; and VRK2B, with 397 aminoacids lacking the C-terminal region and detected both in cytosol and nucleus, perhaps functionally replacing in some aspects VRK1 and detected only in some cellular types, like adenocarcinomas [22].…
Results)
…VRK1 was more sensitive to TDZD-8 (Fig. 1A) and VRK2 was more sensitive to roscovitine and Cdk1 inhibitor (Fig. 1B).…
Abstract)
…VRK2 is more sensitive to roscovitine, RO 31–8220, Cdk1 inhibitor, AZD7762, and IC261.…
Discussion)
…VRK1 is more sensitive to staurosporine and RO 31–8220, two inhibitors of PKC; while VRK2 is more sensitive to Cdk1 inhibitor and roscovitine, two Cdk1 (cdc2) inhibitors.…
S I O 001029)
…Differential effect of CDK inhibitors on VRK1 and VRK2 and discrimination between VRK1 and VRK2 by staurosporine.…
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Human vaccinia-related kinases (VRK1 and VRK2) are atypical active Ser-Thr kinases implicated in control of cell cycle entry, apoptosis and autophagy, and affect signalling by mitogen activated protein kinases (MAPK). The specific structural differences in VRK catalytic sites make them suitable candidates for development of specific inhibitors. In this work we have determined the sensitivity of VRK1 and VRK2 to kinase inhibitors, currently used in biological assays or in preclinical studies, in order to discriminate between the two proteins as well as with respect to the vaccinia virus B1R kinase. Both VRK proteins and vaccinia B1R are poorly inhibited by inhibitors of different types targeting Src, MEK1, B-Raf, JNK, p38, CK1, ATM, CHK1/2 and DNA-PK, and most of them have no effect even at 100 µM. Despite their low sensitivity, some of these inhibitors in the low micromolar range are able to discriminate between VRK1, VRK2 and B1R. VRK1 is more sensitive to staurosporine, RO-31-8220 and TDZD8. VRK2 is more sensitive to roscovitine, RO 31-8220, Cdk1 inhibitor, AZD7762, and IC261. Vaccinia virus B1R is more sensitive to staurosporine, KU55933, and RO 31-8220, but not to IC261. Thus, the three kinases present a different pattern of sensitivity to kinase inhibitors. This differential response to known inhibitors can provide a structural framework for VRK1 or VRK2 specific inhibitors with low or no cross-inhibition. The development of highly specific VRK1 inhibitors might be of potential clinical use in those cancers where these kinases identify a clinical subtype with a poorer prognosis, as is the case of VRK1 in breast cancer.
<h4>Purpose</h4>To determine whether a Protected Graft Copolymer (PGC) containing fatty acid can be used as a stabilizing excipient for GLP-1 and whether PGC/GLP-1 given once a week can be an effective treatment for diabetes.<h4>Methods</h4>To create a PGC excipient, polylysine was grafted with methoxypolyethyleneglycol and fatty acid at the epsilon amino groups. We performed evaluation of the binding of excipient to GLP-1, the DPP IV sensitivity of GLP-1 formulated with PGC as the excipient, the in vitro bio-activity of excipient-formulated GLP-1, the in vivo pharmacokinetics of excipient-formulated GLP-1, and the efficacy of the excipient-formulated GLP-1 in diabetic rats.<h4>Results</h4>We showed reproducible synthesis of PGC excipient, high affinity binding of PGC to GLP-1, slowed protease degradation of excipient-formulated GLP-1, and that excipient-formulated GLP-1 induced calcium influx in INS cells. Excipient-formulated GLP-1 stays in the blood for at least 4 days. When excipient-formulated GLP-1 was given subcutaneously once a week to diabetic ZDF rats, a significant reduction of HbA1c compared to control was observed. The reduction is similar to diabetic ZDF rats given exendin twice a day.<h4>Conclusions</h4>PGC can be an ideal in vivo stabilizing excipient for biologically labile peptides.
Also flagged:cytarabinehomoharringtonineG-CSFacute myeloid leukemialactate dehydrogenaseLDH
Journal Article2011-08-04No SnippetsWu L, Li X, Su J, He Q, Zhang X, Chang C, Pu Q.
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<h4>Background</h4>To evaluate the efficacy and toxicity of CHG regimen (low-dose cytarabine, homoharringtonine with G-CSF priming) as an induction chemotherapy for elderly patients with high-risk MDS or acute myeloid leukemia transformed from MDS (MDS-AML).<h4>Methods</h4>Thirty-three untreated patients (21 high-risk MDS and 12 MDS-AML) were enrolled in this study. Each patient was administered with the CHG regimen comprised of low-dose cytarabine (25 mg/day, days 1-14) and homoharringtonine (1 mg/day, days 1-14) by intravenous continuous infusion in combination with G-CSF (300 μg/day) by subcutaneous injection from day 0 until neutrophil count recovery to 2.0 × 10(9)/L.<h4>Results</h4>The overall response rate (OR) was 66.7% after one course of the CHG regimen with 19 patients reaching CR (57.6%) and 3 patients reaching partial remission (PR) (9.1%). The median overall survival (OS) was 15.0 months. Patients with normal serum lactate dehydrogenase (LDH) appeared longer median OS when compared to patients with high LDH level (18 months vs. 5 months, P = 0.011). Grade 3/4 thrombocytopenia occurred in 28% of patients, neutropenia in 34%. No treatment-related deaths occurred during the induction therapy.<h4>Conclusions</h4>These data suggest that the CHG priming regimen is effective and safe as a novel induction therapy for elderly patients with high-risk MDS and MDS-AML. The results need to be conformed in further study involving a larger cohort of patients.
Also flagged:Synthesisnon-small cell lung cancerNSCLCcarcinomaspeptidebinding
Journal Article2011-08-04No SnippetsLi S, Gray BP, McGuire MJ, Brown KC.
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The integrin α(v)β(6) is an emergent biomarker for non-small cell lung cancer (NSCLC) as well as other carcinomas. We previously developed a tetrameric peptide, referred to as H2009.1, which binds α(v)β(6) and displays minimal affinity for other RGD-binding integrins. Here we report the use of this peptide to actively deliver paclitaxel to α(v)β(6)-positive cells. We synthesized a water soluble paclitaxel-H2009.1 peptide conjugate in which the 2'-position of paclitaxel is attached to the tetrameric peptide via an ester linkage. The conjugate maintains its specificity for α(v)β(6)-expressing NSCLC cells, resulting in selective cytotoxicity. Treatment of α(v)β(6)-positive cells with the conjugate results in cell cycle arrest followed by induction of apoptosis in the same manner as free paclitaxel. However, initiation of apoptosis and the resultant cell death is delayed compared to free drug. The conjugate demonstrates anti-tumor activity in a H2009 xenograft model of NSCLC with efficacy comparable to treatment with free paclitaxel.
Also flagged:Bioconcentrationmetabolismexcretiontriclocarbanepoxide hydrolasewater
Journal Article2011-08-04No SnippetsSchebb NH, Flores I, Kurobe T, Franze B, Ranganathan A, Hammock BD, Teh SJ.
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The antimicrobial triclocarban (TCC) is frequently found in personal care products and commonly observed in surface waters and sediments. Due to its long environmental persistence TCC accumulates in sewage sludge. It also shows a high unintended biological activity as a potent inhibitor of the soluble epoxide hydrolase (sEH) and may be an endocrine disruptor. In this study, we investigated bioconcentration, metabolism and elimination of TCC in fish using medaka (Oryzias latipes) as a model. Medaka larvae (7 ± 1 days post hatching) were exposed to 63 nM (20 μg/L) TCC water for 24h. The LC-MS/MS analysis of water and tissues provided bioconcentration of TCC and its metabolites in fish body and rapid excretion into culture water. Results from tissue samples showed a tissue concentration of 34 μmol/kg and a log bioconcentration factor (BCF) of 2.86. These results are slightly lower than previous findings in snails and algae. A significant portion of the absorbed TCC was oxidatively metabolized by the fish to hydroxylated products. These metabolites underwent extensive phase II metabolism to yield sulfate and glucuronic acid conjugates. The most abundant metabolite in fish tissue was the glucuronide of 2'-OH-TCC. Elimination of TCC after transferring the fish to fresh water was rapid, with a half-life of 1h. This study shows that larval medaka metabolize TCC similarly to mammals. The rapid rate of metabolism results in a lower bioconcentration than calculated from the octanol-water coefficient of TCC.
This paper aims to build novel methodology for the use of a reference region with specific binding for the quantification of brain studies with radioligands and positron emission tomography (PET). In particular: (1) we introduce a definition of binding potential BP(D)=DVR-1 where DVR is the volume of distribution relative to a reference tissue that contains ligand in specifically bound form, (2) we validate a numerical methodology, rank-shaping regularization of exponential spectral analysis (RS-ESA), for the calculation of BP(D) that can cope with a reference region with specific bound ligand, (3) we demonstrate the use of RS-ESA for the accurate estimation of drug occupancies with the use of correction factors to account for the specific binding in the reference. [(11)C]-DASB with cerebellum as a reference was chosen as an example to validate the methodology. Two data sets were used; four normal subjects scanned after infusion of citalopram or placebo and further six test-retest data sets. In the drug occupancy study, the use of RS-ESA with cerebellar input plus corrections produced estimates of occupancy very close the ones obtained with plasma input. Test-retest results demonstrated a tight linear relationship between BP(D) calculated either with plasma or with a reference input and high reproducibility.
Also flagged:Huntington's diseaseHuntingtinHDautosomalneurodegenerative disordercitrate
Journal Article2011-08-03✓ 1 SnippetQuarrell OW, Handley O, O'Donovan K, Dumoulin C, Ramos-Arroyo M, Biunno I, Bauer P, Kline M, Landwehrmeyer GB, European Huntington’s Disease Network.
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Text
…HTT…
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Huntington's disease results from a CAG repeat expansion within the Huntingtin gene; this is measured routinely in diagnostic laboratories. The European Huntington's Disease Network REGISTRY project centrally measures CAG repeat lengths on fresh samples; these were compared with the original results from 121 laboratories across 15 countries. We report on 1326 duplicate results; a discrepancy in reporting the upper allele occurred in 51% of cases, this reduced to 13.3% and 9.7% when we applied acceptable measurement errors proposed by the American College of Medical Genetics and the Draft European Best Practice Guidelines, respectively. Duplicate results were available for 1250 lower alleles; discrepancies occurred in 40% of cases. Clinically significant discrepancies occurred in 4.0% of cases with a potential unexplained misdiagnosis rate of 0.3%. There was considerable variation in the discrepancy rate among 10 of the countries participating in this study. Out of 1326 samples, 348 were re-analysed by an accredited diagnostic laboratory, based in Germany, with concordance rates of 93% and 94% for the upper and lower alleles, respectively. This became 100% if the acceptable measurement errors were applied. The central laboratory correctly reported allele sizes for six standard reference samples, blind to the known result. Our study differs from external quality assessment (EQA) schemes in that these are duplicate results obtained from a large sample of patients across the whole diagnostic range. We strongly recommend that laboratories state an error rate for their measurement on the report, participate in EQA schemes and use reference materials regularly to adjust their own internal standards.
Also flagged:Heat shock factor 2proteostasisHeat shock responseheat shock proteinsHSPsHSP proteins
Journal Article2011-08-03✓ 3 SnippetsShinkawa T, Tan K, Fujimoto M, Hayashida N, Yamamoto K, Takaki E, Takii R, Prakasam R, Inouye S, Mezger V, Nakai A.
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Methods)
…x genotypes, including HSF2wt/Htt, HSF2-hetero/Htt, and HSF2-ko…
Methods)
…uding HSF2wt/Htt, HSF2-hetero/Htt, and HSF2-ko/Htt, had…
Methods)
… HSF2-hetero/Htt, and HSF2-ko/Htt, had a mixed…
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Heat shock response is characterized by the induction of heat shock proteins (HSPs), which facilitate protein folding, and non-HSP proteins with diverse functions, including protein degradation, and is regulated by heat shock factors (HSFs). HSF1 is a master regulator of HSP expression during heat shock in mammals, as is HSF3 in avians. HSF2 plays roles in development of the brain and reproductive organs. However, the fundamental roles of HSF2 in vertebrate cells have not been identified. Here we find that vertebrate HSF2 is activated during heat shock in the physiological range. HSF2 deficiency reduces threshold for chicken HSF3 or mouse HSF1 activation, resulting in increased HSP expression during mild heat shock. HSF2-null cells are more sensitive to sustained mild heat shock than wild-type cells, associated with the accumulation of ubiquitylated misfolded proteins. Furthermore, loss of HSF2 function increases the accumulation of aggregated polyglutamine protein and shortens the lifespan of R6/2 Huntington's disease mice, partly through αB-crystallin expression. These results identify HSF2 as a major regulator of proteostasis capacity against febrile-range thermal stress and suggest that HSF2 could be a promising therapeutic target for protein-misfolding diseases.
Also flagged:pyruvate kinasedeficiencychronic illnesshemolytic crisishyperbilirubinemiainfections
Journal Article2011-08-03✓ 2 SnippetsRider NL, Strauss KA, Brown K, Finkenstedt A, Puffenberger EG, Hendrickson CL, Robinson DL, Muenke N, Tselepis C, Saunders L, Zoller H, Morton DH.
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Abstract)
…Hemochromatosisaffected 29% (n…
Abstract)
…high prevalence ofHFEgene mutations exists…
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Pyruvate kinase deficiency is a chronic illness with age specific consequences. Newborns suffer life-threatening hemolytic crisis and hyperbilirubinemia. Adults are at risk for infections because of asplenia, pregnancy-related morbidity, and may suffer organ damage because of systemic iron overload. We describe 27 Old Order Amish patients (ages 8 months-52 years) homozygous for c.1436G>A mutations in PKLR. Each subject had a predictable neonatal course requiring packed red blood cell transfusions (30 ± 5 mL/kg) to control hemolytic disease and intensive phototherapy to prevent kernicterus. Hemochromatosis affected 29% (n = 4) of adult patients, who had inappropriately normal serum hepcidin (34.5 ± 12.7 ng/mL) and GDF-15 (595 ± 335pg/mL) relative to hyperferritinemia (769 ± 595 mg/dL). A high prevalence of HFE gene mutations exists in this population and may contribute to iron-related morbidity. Based on our observations, we present a strategy for long-term management of pyruvate kinase deficiency.
Also flagged:ALOX5APintracerebral hemorrhageeicosanoidbiosynthesisischemic strokeIS
Journal Article2011-08-03✓ 2 SnippetsKim DH, Ahn WY, Kim DK, Choe BK, Kim SK, Jo DJ, Kim JY, Chung JH, Jeong YS, Yun DH, Yoo SD, Kim HS, Baik HH.
In-Text Gene Mentions
Abstract)
…To investigate whether single nucleotide polymorphisms (SNPs) of eicosanoid biosynthesis genes are associated with intracerebral hemorrhage (ICH) and ischemic stroke (IS), seven SNPs in the coding or promoter regions were selected: ALOX12 (rs434473, Asn322Ser), ALOX5 (rs2228064, Thr90Thr), ALOX5AP (rs17222919, -1316T/G), PTGES (rs7872802, -404A/G), PTGIS (rs5628, Leu256Leu), PTGS1 (rs3842788, Gln41Gln) and PTGS2 (rs5275, 3'UTR).…
To investigate whether single nucleotide polymorphisms (SNPs) of eicosanoid biosynthesis genes are associated with intracerebral hemorrhage (ICH) and ischemic stroke (IS), seven SNPs in the coding or promoter regions were selected: ALOX12 (rs434473, Asn322Ser), ALOX5 (rs2228064, Thr90Thr), ALOX5AP (rs17222919, -1316T/G), PTGES (rs7872802, -404A/G), PTGIS (rs5628, Leu256Leu), PTGS1 (rs3842788, Gln41Gln) and PTGS2 (rs5275, 3'UTR). A total of 398 control subjects and 196 stroke patients (79 ICH and 117 IS) were genotyped by direct sequencing. The rs17222919 SNP was associated with ICH in codominant 1 (P=0.008), dominant (P=0.003) and log-additive (P=0.004) models. Allele frequencies of rs17222919 were different between ICH and controls (P=0.007). However, the seven tested SNPs were not associated with clinical phenotypes (NIHSS, MBI and CRPS) in ICH and IS. These results suggest that the promoter SNP rs17222919 of ALOX5AP may be associated with the development of ICH in Korean population.
Also flagged:metabolismprotein synthesisserine proteasesmetalloproteinasesproteasevasodilation
Journal Article2011-08-03No SnippetsWong ES, Papenfuss AT, Whittington CM, Warren WC, Belov K.
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Gene duplication followed by adaptive selection is believed to be the primary driver of venom evolution. However, to date, no studies have evaluated the importance of gene duplications for venom evolution using a genomic approach. The availability of a sequenced genome and a venom gland transcriptome for the enigmatic platypus provides a unique opportunity to explore the role that gene duplication plays in venom evolution. Here, we identify gene duplication events and correlate them with expressed transcripts in an in-season venom gland. Gene duplicates (1,508) were identified. These duplicated pairs (421), including genes that have undergone multiple rounds of gene duplications, were expressed in the venom gland. The majority of these genes are involved in metabolism and protein synthesis not toxin functions. Twelve secretory genes including serine proteases, metalloproteinases, and protease inhibitors likely to produce symptoms of envenomation such as vasodilation and pain were detected. Only 16 of 107 platypus genes with high similarity to known toxins evolved through gene duplication. Platypus venom C-type natriuretic peptides and nerve growth factor do not possess lineage-specific gene duplicates. Extensive duplications, believed to increase the potency of toxic content and promote toxin diversification, were not found. This is the first study to take a genome-wide approach in order to examine the impact of gene duplication on venom evolution. Our findings support the idea that adaptive selection acts on gene duplicates to drive the independent evolution and functional diversification of similar venom genes in venomous species. However, gene duplications alone do not explain the "venome" of the platypus. Other mechanisms, such as alternative splicing and mutation, may be important in venom innovation.
Also flagged:AUF1HuRmetabolismlocalizationadenylatebinding
Journal Article2011-08-03No SnippetsTrojanowicz B, Dralle H, Hoang-Vu C.
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RNA-binding proteins may regulate every aspect of RNA metabolism, including pre-mRNA splicing, mRNA trafficking, stability and translation of many genes. The dynamic association of these proteins with RNA defines the lifetime, cellular localization, processing and the rate at which a specific mRNA is translated. One of the pathways involved in regulating of mRNA stability is mediated by adenylate uridylate-rich element (ARE) binding proteins. These proteins are involved in processes of apoptosis, tumorigenesis and development. Out of many ARE-binding proteins, two of them AUF1 and HuR were studied most extensively and reported to regulate the mRNA stability in vivo. Our previously published data demonstrate that both proteins are involved in thyroid carcinogenesis. Several other reports postulate that mRNA binding proteins may participate in thyroid hormone actions. However, until now, exacts mechanisms and the possible role of post-transcriptional regulation and especially the role of AUF1 and HuR in those processes remain not fully understood. In this study we shortly review the possible function of both proteins in relation to development and various physiological and pathophysiological processes, including thyroid function and disorders.
Also flagged:aminecell adhesioncytokineethylenediamine2-aminoethyl methacrylate hydrochloridepolyethersulphone
Journal Article2011-08-03No SnippetsJiang X, Christopherson GT, Mao HQ.
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Previous studies have shown that substrate surface chemistry and topography exhibit significant impact on haematopoietic progenitor cell adhesion, proliferation and differentiation. In the present study, the effect of surface amine density and structure of grafted polymer chains on the adhesion and expansion of haematopoietic progenitor cells was investigated. Cryopreserved human umbilical cord blood CD133(+) cells were expanded in cytokine-supplemented medium on ethylenediamine (EDA)- or 2-aminoethyl methacrylate hydrochloride (AEMA)-grafted polyethersulphone (PES) nanofibre scaffolds for 10 days. Although the percentage of CD34(+) cells among the expanded cells increased with the surface amine density, the maximum fold expansion of CD34(+) cells was obtained at a moderate amine density of 20-80 nmol cm(-2). When comparing nanofibre matrices with similar amine densities, but prepared with two different methods, cells cultured on the AEMA-grafted PES nanofibre matrix showed lower fold expansion in terms of total cell number (300 ± 84 fold) and CD34(+) cell number (68 ± 19-fold) in comparison with those cultured on EDA-grafted nanofibres (787 ± 84-fold and 185 ± 84-fold, respectively). These results indicate that the surface amine density and the conjugate structure are important determinants for the preservation of CD34 surface marker and expansion efficiency of CD34(+) cells.
Journal Article2011-08-02✓ 1 SnippetYu H, Liu BH, Ye ZQ, Li C, Li YX, Li YY.
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Results)
…genes: Tcf4 andDcc[ 32 ];…
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<h4>Background</h4>Differential coexpression analysis (DCEA) is increasingly used for investigating the global transcriptional mechanisms underlying phenotypic changes. Current DCEA methods mostly adopt a gene connectivity-based strategy to estimate differential coexpression, which is characterized by comparing the numbers of gene neighbors in different coexpression networks. Although it simplifies the calculation, this strategy mixes up the identities of different coexpression neighbors of a gene, and fails to differentiate significant differential coexpression changes from those trivial ones. Especially, the correlation-reversal is easily missed although it probably indicates remarkable biological significance.<h4>Results</h4>We developed two link-based quantitative methods, DCp and DCe, to identify differentially coexpressed genes and gene pairs (links). Bearing the uniqueness of exploiting the quantitative coexpression change of each gene pair in the coexpression networks, both methods proved to be superior to currently popular methods in simulation studies. Re-mining of a publicly available type 2 diabetes (T2D) expression dataset from the perspective of differential coexpression analysis led to additional discoveries than those from differential expression analysis.<h4>Conclusions</h4>This work pointed out the critical weakness of current popular DCEA methods, and proposed two link-based DCEA algorithms that will make contribution to the development of DCEA and help extend it to a broader spectrum.
The fetal genome regulates maternal physiology and behavior via its placenta, which produces hormones that act on the maternal hypothalamus. At the same time, the fetus itself develops a hypothalamus. In this study we show that many of the genes that regulate placental development also regulate the developing hypothalamus, and in mouse the coexpression of these genes is particularly high on embryonic days 12 and 13 (days E12-13). Such synchronized expression is regulated, in part, by the maternally imprinted gene, paternally expressed gene 3 (Peg3), which also is developmentally coexpressed in the hypothalamus and placenta at days E12-13. We further show that challenging this genomic linkage of hypothalamus and placenta with 24-h food deprivation results in disruption to coexpressed genes, primarily by affecting placental gene expression. Food deprivation also produces a significant decrease in Peg3 gene expression in the placenta, with consequences similar to many of the placental gene changes induced by Peg3 mutation. Such genomic dysregulation does not occur in the hypothalamus, where Peg3 expression increases with food deprivation. Thus, changes in gene expression brought about by food deprivation are consistent with the fetal genome's maintaining hypothalamic development at a cost to its placenta. This biased change to gene dysregulation in the placenta is linked to autophagy and ribosomal turnover, which sustain, in the short term, nutrient supply for the developing hypothalamus. Thus, the fetus controls its own destiny in times of acute starvation by short-term sacrifice of the placenta to preserve brain development.
Also flagged:ADP-ribosylation factorADP-ribosylation factorsguanine nucleotide exchange factorsmembraneARF GEFsARF
Journal Article2011-08-02No SnippetsLowery J, Szul T, Seetharaman J, Jian X, Su M, Forouhar F, Xiao R, Acton TB, Montelione GT, Lin H, Wright JW, Lee E, Holloway ZG, Randazzo PA, Tong L, Sztul E.
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ADP-ribosylation factors (ARFs) and their activating guanine nucleotide exchange factors (GEFs) play key roles in membrane traffic and signaling. All ARF GEFs share a ∼200-residue Sec7 domain (Sec7d) that alone catalyzes the GDP to GTP exchange that activates ARF. We determined the crystal structure of human BIG2 Sec7d. A C-terminal loop immediately following helix J (loop>J) was predicted to form contacts with helix H and the switch I region of the cognate ARF, suggesting that loop>J may participate in the catalytic reaction. Indeed, we identified multiple alanine substitutions within loop>J of the full length and/or Sec7d of two large brefeldin A-sensitive GEFs (GBF1 and BIG2) and one small brefeldin A-resistant GEF (ARNO) that abrogated binding of ARF and a single alanine substitution that allowed ARF binding but inhibited GDP to GTP exchange. Loop>J sequences are highly conserved, suggesting that loop>J plays a crucial role in the catalytic activity of all ARF GEFs. Using GEF mutants unable to bind ARF, we showed that GEFs associate with membranes independently of ARF and catalyze ARF activation in vivo only when membrane-associated. Our structural, cell biological, and biochemical findings identify loop>J as a key regulatory motif essential for ARF binding and GDP to GTP exchange by GEFs and provide evidence for the requirement of membrane association during GEF activity.
Journal Article2011-08-02No SnippetsNelson BR, Ueki Y, Reardon S, Karl MO, Georgi S, Hartman BH, Lamba DA, Reh TA.
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Previous studies have shown that Müller glia are closely related to retinal progenitors; these two cell types express many of the same genes and after damage to the retina, Müller glia can serve as a source for new neurons, particularly in non-mammalian vertebrates. We investigated the period of postnatal retinal development when progenitors are differentiating into Müller glia to better understand this transition. FACS purified retinal progenitors and Müller glia from various ages of Hes5-GFP mice were analyzed by Affymetrix cDNA microarrays. We found that genes known to be enriched/expressed by Müller glia steadily increase over the first three postnatal weeks, while genes associated with the mitotic cell cycle are rapidly downregulated from P0 to P7. Interestingly, progenitor genes not directly associated with the mitotic cell cycle, like the proneural genes Ascl1 and Neurog2, decline more slowly over the first 10-14 days of postnatal development, and there is a peak in Notch signaling several days after the presumptive Müller glia have been generated. To confirm that Notch signaling continues in the postmitotic Müller glia, we performed in situ hybridization, immunolocalization for the active form of Notch, and immunofluorescence for BrdU. Using genetic and pharmacological approaches, we found that sustained Notch signaling in the postmitotic Müller glia is necessary for their maturation and the stabilization of the glial identity for almost a week after the cells have exited the mitotic cell cycle.
Also flagged:Lung cancercancerdeathnon-small cell lung tumorstumorstumor
Journal Article2011-08-02No SnippetsHuang YT, Lin X, Chirieac LR, McGovern R, Wain JC, Heist RS, Skaug V, Zienolddiny S, Haugen A, Su L, Christiani DC.
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Lung cancer, of which more than 80% is non-small cell, is the leading cause of cancer-related death in the United States. Copy number alterations (CNAs) in lung cancer have been shown to be positionally clustered in certain genomic regions. However, it remains unclear whether genes with copy number changes are functionally clustered. Using a dense single nucleotide polymorphism array, we performed genome-wide copy number analyses of a large collection of non-small cell lung tumors (n = 301). We proposed a formal statistical test for CNAs between different groups (e.g., non-involved lung vs. tumors, early vs. late stage tumors). We also customized the gene set enrichment analysis (GSEA) algorithm to investigate the overrepresentation of genes with CNAs in predefined biological pathways and gene sets (i.e., functional clustering). We found that CNAs events increase substantially from germline, early stage to late stage tumor. In addition to genomic position, CNAs tend to occur away from the gene locations, especially in germline, non-involved tissue and early stage tumors. Such tendency decreases from germline to early stage and then to late stage tumors, suggesting a relaxation of selection during tumor progression. Furthermore, genes with CNAs in non-small cell lung tumors were enriched in certain gene sets and biological pathways that play crucial roles in oncogenesis and cancer progression, demonstrating the functional aspect of CNAs in the context of biological pathways that were overlooked previously. We conclude that CNAs increase with disease progression and CNAs are both positionally and functionally clustered. The potential functional capabilities acquired via CNAs may be sufficient for normal cells to transform into malignant cells.
Also flagged:head and neck squamous cell carcinomaHead and neck squamous cell cancercancerprimary tumorsHNSCCtumors
Journal Article2011-08-01No SnippetsSahu N, Grandis JR.
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Head and neck squamous cell cancer is the sixth most common cancer in the world. Despite advances in combined modality therapy, poor outcomes continue to be observed in the form of locoregional recurrence, metastasis, and development of second primary tumors. As tumors vary in their molecular and genetic etiology and because often there is already deregulation at the molecular level in otherwise histopathologically normal tissue, risk stratification using clinical and pathologic criteria alone has proved to be inadequate. In this article, the reader will gain an appreciation for the current advances in biomarker discovery using advanced technology and data interpretation in microarray analysis and proteomics. In addition, other molecular targets, aside from epidermal growth factor receptor, are discussed in the context of their promising role in predicting recurrence, response to therapy, survival, and overall prognosis.
Also flagged:Nfat1osteoarthritisOAChromatinhistonelysine-specific demethylase-1
Journal Article2011-08-01✓ 1 SnippetRodova M, Lu Q, Li Y, Woodbury BG, Crist JD, Gardner BM, Yost JG, Zhong XB, Anderson HC, Wang J.
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…Sox6…
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The development of disease-modifying pharmacologic therapy for osteoarthritis (OA) currently faces major obstacles largely because the regulatory mechanisms for the function of adult articular chondrocytes remain unclear. We previously demonstrated that lack of Nfat1, one of the nuclear factor of activated T cells (NFAT) transcription factors, causes OA-like changes in adult mice. This study aimed to identify whether Nfat1 specifically regulates adult articular chondrocyte function and its age-dependent regulatory mechanism using both Nfat1-deficient and wild-type mice. Deletion of Nfat1 did not induce OA-like articular chondrocyte dysfunction (e.g., overexpression of proinflammatory cytokines and matrix-degrading proteinases) until the adult stage. RNAi-mediated Nfat1 knockdown caused dysfunction of wild-type adult articular chondrocytes. Nfat1 expression in wild-type articular chondrocytes was low in the embryonic but high in the adult stage. Chromatin immunoprecipitation assays demonstrated that an increase in Nfat1 expression in articular chondrocytes was associated with increased H3K4me2 (a histone modification linked to transcriptional activation), whereas a decrease in Nfat1 expression in articular chondrocytes was correlated with increased H3K9me2 (a histone modification linked to transcriptional repression). Knockdown of lysine-specific demethylase-1 (Lsd1) in embryonic articular chondrocytes upregulated Nfat1 expression concomitant with increased H3K4me2 at the Nfat1 promoter. Knockdown of Jmjc-containing histone demethylase-2a (Jhdm2a) in 6-month articular chondrocytes downregulated Nfat1 expression concomitant with increased H3K9me2 at the Nfat1 promoter. These results suggest that Nfat1 is an essential transcriptional regulator of chondrocyte homeostasis in adult articular cartilage. Age-dependent Nfat1 expression in articular chondrocytes is regulated by dynamic histone methylation, one of the epigenetic mechanisms that regulate gene transcription.
Also flagged:polyunsaturated fatty acidneurogenesisanxietyserotonin transporterbehavioralphospholipids
Journal Article2011-08-01✓ 2 SnippetsSchipper P, Kiliaan AJ, Homberg JR.
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…modeling the human5-HTTlength polymorphic region…
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…treat anxiety in5-HTTlength polymorphic region…
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The aim of this study was to investigate the effects of a mixed dietary intervention on behavioral symptoms in serotonin transporter knockout (5-HTT⁻/⁻) rats modeling the human 5-HTT length polymorphic region short-allele. Twenty female 5-HTT⁻/⁻ and 19 wild-type (5-HTT⁺/⁺) rats were fed for 3 months on a mixed polyunsaturated fatty acid (PUFA) diet comprising n-3 PUFAs, B vitamins and phospholipids, or an isocaloric control diet, and a subgroup was subsequently tested in an array of anxiety-related behavioral tests. All brains were harvested and immunostained for doublecortin, a neurogenesis marker. In addition, hippocampal volume was measured. 5-HTT⁻/⁻ rats on the control diet displayed increased anxiety-related behavioral responses, and impaired fear extinction. These effects were completely offset by the mixed PUFA diet, whereas this diet had no behavioral effect in 5-HTT⁺/⁺ rats. In parallel, dentate gyrus doublecortin immunoreactivity was increased in 5-HTT⁻/⁻ rats fed on the control diet, which was reversed by the mixed PUFA diet. Hippocampal volume was unaffected by the mixed PUFA diet in 5-HTT⁻/⁻ subjects, whereas it increased in 5-HTT⁺/⁺ rats. We conclude that a mixed n-3 PUFA diet ameliorates anxiety-related symptoms in a genotype-dependent manner, potentially by normalizing neurogenesis. We suggest that such a mixed diet may serve as an attractive adjuvant to treat anxiety in 5-HTT length polymorphic region short-allele carriers.
<h4>Background</h4>HFE hemochromatosis (HFE-H) is the most common and well-defined inherited cause for iron-related morbidity and mortality. Majority of patients with HFE-H are homozygote for C282Y mutation. Recent studies suggest that iron accumulation in most types of hemochromatosis is due to deficiency of hepcidin, a central iron regulator. However, the precise link between hepcidin levels and iron absorption in HFE-H patients has been poorly understood.<h4>Aim</h4>To measure hepcidin response to oral iron challenge (200 mg ferrous sulphate), in HFE-H (C282Y/C282Y) patients and compare with healthy controls (HCs).<h4>Methods</h4>Nine patients with C282Y/C282Y HFE-H along with 15 HC were recruited for the study. All HFE-H were iron depleted and studied at a time distant to phlebotomy. Hepcidin was measured using a published immunoassay method after ingestion of 65 mg oral iron challenge. Serum iron, ferritin and transferrin saturation were measured using standard methods. The area under the curve was calculated and compared between the two groups.<h4>Results</h4>The basal serum hepcidin levels in patients with HFE-H were significantly low as compared with HC (P=0.0002). Incremental serum hepcidin response seen in HC reached significance at 4 h post iron challenge (P=0.0085) returning to baseline only at 24 h. There was no significant hepcidin response in HFE-H at 4 h (P=0.294). The overall hepcidin response was significantly lower in HFE-H compared with HC (area under the curve: P=0.0127).<h4>Conclusion</h4>Failure to mount a rapid hepcidin response to an oral iron challenge is the key mechanisms of iron accumulation despite prevailing excess body iron in patients with HFE-H with C282Y/C282Y mutation.
Also flagged:gene expressionmelanomaPigment epithelium-derived factorPEDFangiogenesistumor
Journal Article2011-08-01No SnippetsOrgaz JL, Benguria A, Sanchez-Martinez C, Ladhani O, Volpert OV, Jimenez B.
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Pigment epithelium-derived factor (PEDF) is a broad-spectrum angiogenesis inhibitor that displays potent antimetastatic activity in multiple tumor types. We have previously shown that PEDF prevents primary tumor growth and metastatic spread of human melanoma in mouse experimental models. Consistent with these observations, PEDF expression is lost at the late stages of melanoma progression, allowing melanoma cells to become angiogenic, migratory, and invasive. PEDF's ability to modify the interplay between the host and tumor tissues strongly supports its use as a therapeutic agent for the treatment of metastatic melanoma. However, transition to the clinic requires a more detailed knowledge of the molecular mechanisms underpinning PEDF's activity. In this study, we describe changes in the gene expression profile of A375 human melanoma cells induced by PEDF overexpression. PEDF modulated diverse categories of genes known to be involved in angiogenesis and migration. It downregulated cytokines such as interleukin-8 and extracellular matrix proteins such as collagen IV, while it upregulated fibronectin. Multiple transcripts previously described as contributing to the acquisition of malignant phenotype by melanoma were also diminished by PEDF overexpression, among which we validated galectin 3 and jagged 1. In addition, PEDF downregulated S100β and melanoma inhibitory activity, which are widely used in the pathological diagnosis of melanoma. Interestingly, PEDF increased the expression of melanophilin and decreased rab27A, which are relevant targets for melanosome transport; suggesting that PEDF could directly impinge on melanocytic lineage-specific processes. Our study identifies new molecular targets and signaling pathways that may potentially contribute to determine PEDF's ability to restrict the aggressiveness of A375 human melanoma cells.
Also flagged:maniabipolar disorderattention-deficit hyperactivity disorderADHDdepressionanxiety
Journal Article2011-08-01✓ 1 SnippetGoldsmith M, Singh M, Chang K.
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This article reviews the literature that examines whether exposure to psychostimulants or antidepressants precipitates or exacerbates manic symptoms, or decreases the age at onset of mania in pediatric populations. A PubMed search using relevant key words identified studies targeting five distinct clinical groups: (i) youth without a diagnosis of bipolar disorder (BD) at the time of exposure to psychostimulants; (ii) youth with a diagnosis of BD at the time of exposure to psychostimulants; (iii) youth without a diagnosis of BD at the time of exposure to antidepressants; (iv) youth with a diagnosis of BD at the time of exposure to antidepressants; and (v) youth who develop BD after exposure to these medications. In patients with attention-deficit hyperactivity disorder (ADHD), the risk for mania was found to be relatively low with the use of psychostimulants. For patients with BD and ADHD, effective mood stabilization is important prior to adding a stimulant. For children with depression and/or anxiety, the risk of antidepressant-induced mania (AIM) was generally low (<2%), but the risk of general 'activation' secondary to a selective serotonin reuptake inhibitor (SSRI) may be greater (2-10%). However, rates of AIM in specialty clinics appear to be much higher. SSRIs may be particularly problematic in specific populations, such as those with some symptoms of mania or a family history of BD, but the precise risk is unknown. There is no clear evidence that stimulants or SSRIs accelerate the natural course of BD development in overall samples, but in individual cases prescribers should proceed cautiously when using these agents in youth already at risk for developing BD, such as those with ADHD and mood dysregulation, a history of prior AIM, a history of psychosis, or a family history of BD.
This study examined whether polymorphisms in the serotonin transporter (SLC6A4, 5-HTTLPR) and brain-derived neurotropic factor (BDNF Val66Met, rs6265) genes moderate the relationship between life stress and rumination. Participants were a large homogenous group of healthy, unmedicated, never depressed individuals with few current symptoms of depression (N = 273). Results indicate that individuals with two short (S) alleles of the 5-HTTLPR polymorphism or two Met alleles of the BDNF Val66Met polymorphism ruminate more under conditions of life stress, compared to the other genotypes. Moreover, the accumulation of risk alleles (i.e. S and Met alleles) across genes is associated with significantly greater rumination in the context of life stress. These results suggest that both 5-HTTLPR and BDNF Val66Met moderate the relationship between life stress and rumination. These findings support the notion that variation in these genes is associated with biological sensitivity to the negative effects of stress.
Also flagged:chaperonesprotein degradationMolecular chaperonesorganizationdegradationprotein homeostasis
Journal Article2011-08-01✓ 1 SnippetChen B, Retzlaff M, Roos T, Frydman J.
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Eukaryotic cells must contend with a continuous stream of misfolded proteins that compromise the cellular protein homeostasis balance and jeopardize cell viability. An elaborate network of molecular chaperones and protein degradation factors continually monitor and maintain the integrity of the proteome. Cellular protein quality control relies on three distinct yet interconnected strategies whereby misfolded proteins can either be refolded, degraded, or delivered to distinct quality control compartments that sequester potentially harmful misfolded species. Molecular chaperones play a critical role in determining the fate of misfolded proteins in the cell. Here, we discuss the spatial and temporal organization of cellular quality control strategies and their implications for human diseases linked to protein misfolding and aggregation.
Also flagged:WWP2ubiquitin ligasescell cyclechondrogenesistranscription factorstumour
Journal Article2011-08-01No SnippetsChantry A.
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A number of recent papers on the WWP2 E3 ubiquitin ligase and two novel WWP2 isoforms have revealed important biological insight and disease-specific functions, and also impacted on our understanding of ubiquitin ligases in cell cycle regulation, apoptosis and differentiation. Gene knockout studies suggest a developmental role for WWP2 in chondrogenesis via mechanisms involving cartilage-specific transcription factors. Furthermore, WWP2 isoforms have been shown to selectively target oncogenic signaling pathways linked to both the pTEN tumour suppressor and the TGFβ/Smad signaling pathway. Here, it is suggested that WWP2 isoforms have now emerged as central physiological regulators as well as promising new disease targets, and that the challenge ahead is to now develop highly selective WWP2 inhibitors with utility in cartilage disease such as osteoarthritis and as new anticancer strategies.
Also flagged:autoimmune diabetesCD4lysozymeHELinsulinautoantibodies
Journal Article2011-08-01✓ 1 SnippetSilva DG, Daley SR, Hogan J, Lee SK, Teh CE, Hu DY, Lam KP, Goodnow CC, Vinuesa CG.
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Results)
…Roquin gene (Rc3h1, Roquin san )…
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<h4>Objective</h4>To define cellular mechanisms by which B cells promote type 1 diabetes.<h4>Research design and methods</h4>The study measured islet-specific CD4 T cell regulation in T-cell receptor transgenic mice with elevated frequencies of CD4 T cells recognizing hen egg lysozyme (HEL) autoantigen expressed in islet β-cells and thymic epithelium under control of the insulin-gene promoter. The effects of a mutation in Roquin that dysregulates T follicular helper (Tfh) cells to promote B-cell activation and anti-islet autoantibodies were studied, as were the effects of HEL antigen-presenting B cells and passively transferred or maternally transmitted anti-islet HEL antibodies.<h4>Results</h4>Mouse anti-islet IgG antibodies-either formed as a consequence of excessive Tfh activity, maternally transmitted, or passively transferred-caused a breakdown of tolerance in islet-reactive CD4(+) cells and fast progression to diabetes. Progression to diabetes was ameliorated in the absence of B cells or when the B cells could not secrete islet-specific IgG. Anti-islet antibodies increased the survival of proliferating islet-reactive CD4(+) T cells. FcγR blockade delayed and reduced the incidence of autoimmune diabetes.<h4>Conclusions</h4>B cells can promote type 1 diabetes by secreting anti-islet autoantibodies that act in an FcγR-mediated manner to enhance the expansion of islet-reactive CD4 T cells and cooperate with inherited defects in thymic and peripheral CD4 T-cell tolerance. Cooperation between inherited variants affecting CD4 T-cell tolerance and anti-islet autoantibodies should be examined in epidemiological studies and in studies examining the efficacy of B-cell depletion.
Studies on the mechanisms of decidualization and endometriosis are often hampered by lack of primary endometrial cells. To facilitate in vitro studies, we established a human endometrial stromal cell line, KC02-44D, immortalized with human telomerase reverse transcriptase. Upon exposure to ovarian stimuli, KC02-44D cells showed similar cytoskeletal marker or gene expression and biochemical phenotype to primary endometrial stromal cells. KC02-44D would be useful for studies of human endometrial function and its associated pathologies.
Also flagged:breast cancercancertumorgene expressiononcogenesTumors
Journal Article2011-08-01No SnippetsTran LM, Zhang B, Zhang Z, Zhang C, Xie T, Lamb JR, Dai H, Schadt EE, Zhu J.
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<h4>Background</h4>One of the primary objectives in cancer research is to identify causal genomic alterations, such as somatic copy number variation (CNV) and somatic mutations, during tumor development. Many valuable studies lack genomic data to detect CNV; therefore, methods that are able to infer CNVs from gene expression data would help maximize the value of these studies.<h4>Results</h4>We developed a framework for identifying recurrent regions of CNV and distinguishing the cancer driver genes from the passenger genes in the regions. By inferring CNV regions across many datasets we were able to identify 109 recurrent amplified/deleted CNV regions. Many of these regions are enriched for genes involved in many important processes associated with tumorigenesis and cancer progression. Genes in these recurrent CNV regions were then examined in the context of gene regulatory networks to prioritize putative cancer driver genes. The cancer driver genes uncovered by the framework include not only well-known oncogenes but also a number of novel cancer susceptibility genes validated via siRNA experiments.<h4>Conclusions</h4>To our knowledge, this is the first effort to systematically identify and validate drivers for expression based CNV regions in breast cancer. The framework where the wavelet analysis of copy number alteration based on expression coupled with the gene regulatory network analysis, provides a blueprint for leveraging genomic data to identify key regulatory components and gene targets. This integrative approach can be applied to many other large-scale gene expression studies and other novel types of cancer data such as next-generation sequencing based expression (RNA-Seq) as well as CNV data.
Also flagged:carbohydrateheparan sulfatemethylglycosidesmethylglycosidewaterhydroxymethyl
Journal Article2011-08-01✓ 2 SnippetsSattelle BM, Almond A.
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…the protein antithrombin (ATIII) binds the 2…
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…For example,ATIIIprefers the 2…
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Understanding microsecond-timescale dynamics is crucial to establish three-dimensional (3D) structure-activity relationships in sugars but has been intractable to experiments and simulations. As a consequence, whether arguably the most important chemical scaffold in glycobiology, N-acetyl-d-glucosamine (GlcNAc), deviates from a rigid (4)C(1) chair is unknown. Here, conformer populations and exchange kinetics were quantified from the longest aqueous carbohydrate simulations to date (0.2 ms total) of GlcNAc, four derivatives from heparan sulfate and their methylglycosides. Unmodified GlcNAc took 3-5 μs to reach a conformational equilibrium, which comprised a metastable (4)C(1) chair that underwent (4)C(1) ↔ (1)C(4) transitions at a predicted forward rate of 0.8 μs(-1) with an average (1)C(4)-chair lifetime of 3 ns. These predictions agree with high-resolution crystallography and nuclear magnetic resonance but not with the hypothesis that GlcNAc is a rigid (4)C(1) chair, concluded from previous experimental analyses and non-aqueous modeling. The methylglycoside was calculated to have a slower forward rate (0.3 μs(-1)) and a more stable (4)C(1) conformer (0.2 kcal mol(-1)), suggesting that pivotal 3D intermediates (particularly (2)S(O), (1)S(5) and B(2,5)) increased in energy, and water was implicated as a major cause. Sulfonation (N-, 3-O and 6-O) significantly augmented this effect by blocking pseudorotation, but did not alter the rotational preferences of hydroyxl or hydroxymethyl groups. We therefore propose that GlcNAc undergoes puckering exchange that is dependent on polymerization and sulfo substituents. Our analyses, and 3D model of the equilibrium GlcNAc conformer in water, can be used as dictionary data and present new opportunities to rationally modify puckering and carbohydrate bioactivity, with diverse applications from improving crop yields to disease amelioration.
The polycomb group (PcG) genes encode a family of proteins that methylate and ubiquitinate histones to close chromatin and suppress gene expression. PcG proteins are present at elevated levels in cancer cells, and this is associated with reduced tumor suppressor protein level and enhanced cell survival. Agents that reduce PcG protein level are regarded as potentially cancer-preventative agents. Sulforaphane (SFN) is a biologically important isothiocyanate found in cruciferous vegetables that is an important candidate chemopreventive agent. However, the impact of SFN on the level and function of PcG proteins in skin cancer cells has not been assessed. We show that SFN treatment causes a concentration-dependent reduction in PcG protein (Bmi-1, Ezh2) expression in SCC-13 skin cancer cells and also reduces trimethylation of lysine 27 of histone H3. This is associated with accumulation of cells in G(2)/M phase; reduced levels of cyclin B1, cyclin A, cyclin dependent kinases 1 and 2; and increased p21(Cip1) expression. Sulforaphane treatment also increases cleavage of procaspase 3, 8, and 9 and enhances PARP cleavage and apoptosis. Similar results are observed in other skin-derived cell immortalized and transformed cell lines. Forced expression of the Bmi-1 polycomb protein in SCC-13 cells reverses these effects. The SFN-dependent loss of Bmi-1 and Ezh2 is due to proteasome-associated degradation. These results suggest that dietary isothiocyanates may suppress cancer progression by reducing PcG protein level via a proteasome-dependent mechanism, thereby inhibiting PcG-dependent pro-survival epigenetic events.
Also flagged:cell cyclecyclin-cdkscdkWee1cyclin Amitosis
Journal Article2011-08-01✓ 1 SnippetPagliuca FW, Collins MO, Lichawska A, Zegerman P, Choudhary JS, Pines J.
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Cyclin-dependent kinases comprise the conserved machinery that drives progress through the cell cycle, but how they do this in mammalian cells is still unclear. To identify the mechanisms by which cyclin-cdks control the cell cycle, we performed a time-resolved analysis of the in vivo interactors of cyclins E1, A2, and B1 by quantitative mass spectrometry. This global analysis of context-dependent protein interactions reveals the temporal dynamics of cyclin function in which networks of cyclin-cdk interactions vary according to the type of cyclin and cell-cycle stage. Our results explain the temporal specificity of the cell-cycle machinery, thereby providing a biochemical mechanism for the genetic requirement for multiple cyclins in vivo and reveal how the actions of specific cyclins are coordinated to control the cell cycle. Furthermore, we identify key substrates (Wee1 and c15orf42/Sld3) that reveal how cyclin A is able to promote both DNA replication and mitosis.
Also flagged:peroxiredoxinshydroperoxidedetoxificationperoxidehemecysteine-dependent peroxidases
Journal Article2011-08-01No SnippetsPoole LB, Hall A, Nelson KJ.
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Peroxiredoxins are important hydroperoxide detoxification enzymes, yet have only come to the fore in recent years relative to the other major players in peroxide detoxification, heme-containing catalases and peroxidases and glutathione peroxidases. These cysteine-dependent peroxidases exhibit high reactivity with hydrogen peroxide, organic hydroperoxides, and peroxynitrite and play major roles not only in peroxide defense, but also in regulating peroxide-mediated cell signaling. This overview focuses on important peroxiredoxin features that have emerged over the past several decades with an emphasis on catalytic mechanism, regulation, and biological function.
Also flagged:diabetes mellitusdiabetic neuropathydiabetesPancreatic exocrine insufficiencytype 2 diabetes mellitusinsulin
Journal Article2011-08-01✓ 1 SnippetHardt PD, Ewald N.
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…cystic fibrosis, andhemochromatosis.…
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Pancreatic exocrine insufficiency is a frequently observed phenomenon in type 1 and type 2 diabetes mellitus. Alterations of exocrine pancreatic morphology can also be found frequently in diabetic patients. Several hypotheses try to explain these findings, including lack of insulin as a trophic factor for exocrine tissue, changes in secretion and/or action of other islet hormones, and autoimmunity against common endocrine and exocrine antigens. Another explanation might be that diabetes mellitus could also be a consequence of underlying pancreatic diseases (e.g., chronic pancreatitis). Another pathophysiological concept proposes the functional and morphological alterations as a consequence of diabetic neuropathy. This paper discusses the currently available studies on this subject and tries to provide an overview of the current concepts of exocrine pancreatic insufficiency in diabetes mellitus.
Also flagged:gene expressioncardiac hypertrophyC5a receptorC5aRC5C5a
Journal Article2011-08-01✓ 2 SnippetsMullick A, Tremblay J, Leon Z, Gros P.
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Discussion)
…Therefore it is likely that the low Rgs2 (Fig. 1C) levels and the relatively severe reaction of BALB/c mice to isoproterenol administration (1 out of 8 mice did not survive) are a consequence of the DCC phenotype.…
Discussion)
…consequence of theDCCphenotype.…
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We have previously demonstrated that C5-deficient A/J and recombinant congenic BcA17 mice suffer from cardiac dysfunction when infected with C. albicans blastospores intravenously. During these studies we had observed that, even in the control un-infected state, BcA17 hearts displayed alterations in gene expression that have been associated with pathological cardiac hypertrophy in comparison to parental C5-sufficient C57Bl/6J (B6) mice. Of note was an increase in the expression of Nppb, a member of the fetal gene program and a decrease in the expression of Rgs2, an inhibitor of the hypertrophic response. We now report that C5-deletion has also affected the expression of other elements of the fetal gene program. Moreover deleting the C5a receptor, C5aR, has essentially the same effect as deleting C5, indicating a key role for C5a-C5aR signaling in the phenotype. Having noted a pathological phenotype in the un-infected state, we investigated the role of C5 in the response to cardiac stress. In previous studies, comparison of the expression profiles of C. albicans-infected BcA17 and similarly infected B6 hearts had revealed a paucity of cardioprotective genes in the C5-deficient heart. To determine whether this was also directly linked to C5-deficiency, we tested the expression of 5 such genes in the C. albicans-infected C5aR(-/-) mice. We found again that deletion of C5aR recapitulated the alterations in stress response of BcA17. To determine whether our observations were relevant to other forms of cardiac injury, we tested the effect of C5-deficiency on the response to isoproterenol-induced hypertrophic stimulation. Consistent with our hypothesis, A/J, BcA17 and C5aR(-/-) mice responded with higher levels of Nppa expression than B6 and BALB/c mice. In conclusion, our results suggest that an absence of functional C5a renders the heart in a state of distress, conferring a predisposition to cardiac dysfunction in the face of additional injury.
Highly active anti-retroviral therapy (HAART) restores CD4(+) T-cell numbers in the periphery; however, its efficacy in restoring functional immunity is not fully elucidated. Here we evaluated longitudinal changes in the expression of several key markers of T-cell activation, namely CD40 ligand (CD154), OX40 (CD134), or CD69, after anti-CD3/CD28 activation, as well as levels of IL-12 production after Staphylococcus aureus Cowan stimulation in 28 HIV-infected adult patients. Patients were followed up to 12 mo post-HAART initiation. Viral burdens and CD4 cell counts were measured at the same time points. A control group of 15 HIV-uninfected adult subjects was included for comparison. Significant increases in CD40L and OX40 expression, but not of CD69 expression, were observed over time in the overall patient population, and more particularly in patients with baseline CD4 counts lower than or equal to 200 cells/μL, or those with baseline viral loads lower than or equal to 10(5) RNA copies/mL. Similar increases were seen for IL-12 production. Viral loads were inversely associated with CD40L expression or IL-12 production in a mixed linear model analysis, while CD4 counts were directly associated. CD40L expression and IL-12 production were significantly correlated. In conclusion, HAART-mediated control of viral replication led to partial restoration of CD40L upregulation/expression, and to increased IL-12 production, but the magnitude of the response depended on the baseline characteristics of the treated patients.
Also flagged:PHLPP1tumorAKTcancersphosphataseprostate tumor
Journal Article2011-08-01✓ 1 SnippetChen M, Pratt CP, Zeeman ME, Schultz N, Taylor BS, O'Neill A, Castillo-Martin M, Nowak DG, Naguib A, Grace DM, Murn J, Navin N, Atwal GS, Sander C, Gerald WL, Cordon-Cardo C, Newton AC, Carver BS, Trotman LC.
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…DCC…
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Hyperactivation of the PI 3-kinase/AKT pathway is a driving force of many cancers. Here we identify the AKT-inactivating phosphatase PHLPP1 as a prostate tumor suppressor. We show that Phlpp1-loss causes neoplasia and, on partial Pten-loss, carcinoma in mouse prostate. This genetic setting initially triggers a growth suppressive response via p53 and the Phlpp2 ortholog, and reveals spontaneous Trp53 inactivation as a condition for full-blown disease. Surprisingly, the codeletion of PTEN and PHLPP1 in patient samples is highly restricted to metastatic disease and tightly correlated to deletion of TP53 and PHLPP2. These data establish a conceptual framework for progression of PTEN mutant prostate cancer to life-threatening disease.
Also flagged:Ubiquitin ligasePMLHIF-1prostate cancerTumorCul3
Journal Article2011-08-01✓ 5 SnippetsYuan WC, Lee YR, Huang SF, Lin YM, Chen TY, Chung HC, Tsai CH, Chen HY, Chiang CT, Lai CK, Lu LT, Chen CH, Gu DL, Pu YS, Jou YS, Lu KP, Hsiao PW, Shih HM, Chen RH.
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Abstract)
…Our study indicates that the KLHL20-mediated PML degradation and HIF-1α autoregulation play key roles in tumor progression.…
Title)
…A Cullin3-KLHL20Ubiquitin ligase-dependent pat…
Abstract)
…we show thatKLHL20, a Cullin3 (Cul3)…
Abstract)
…overexpression of HIF-1α,KLHL20, and Pin1 correlates…
Abstract)
…indicates that theKLHL20-mediated PML degradation and…
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Tumor hypoxia is associated with disease progression and treatment failure, but the hypoxia signaling mechanism is not fully understood. Here, we show that KLHL20, a Cullin3 (Cul3) substrate adaptor induced by HIF-1, coordinates with the actions of CDK1/2 and Pin1 to mediate hypoxia-induced PML proteasomal degradation. Furthermore, this PML destruction pathway participates in a feedback mechanism to maximize HIF-1α induction, thereby potentiating multiple tumor hypoxia responses, including metabolic reprogramming, epithelial-mesenchymal transition, migration, tumor growth, angiogenesis, and chemoresistance. In human prostate cancer, overexpression of HIF-1α, KLHL20, and Pin1 correlates with PML down-regulation, and hyperactivation of the PML destruction pathway is associated with disease progression. Our study indicates that the KLHL20-mediated PML degradation and HIF-1α autoregulation play key roles in tumor progression.
Also flagged:methylubiquitinbiomacromoleculesamino acidsamino acidamino
Journal Article2011-08-01No SnippetsLong D, Li DW, Walter KF, Griesinger C, Brüschweiler R.
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The development of the most recent generation of molecular mechanics force fields promises an increasingly predictive understanding of the protein dynamics-function relationship. Based on extensive validation against various types of experimental data, the AMBER force field ff99SB was benchmarked in recent years as a favorable force field for protein simulations. Recent improvements of the side chain and backbone potentials, made by different groups, led to the ff99SB-ILDN and ff99SBnmr1 force fields, respectively. The combination of these potentials into a unified force field, termed ff99SBnmr1-ILDN, was used in this study to perform a microsecond time scale molecular dynamics simulation of free ubiquitin in explicit solvent for validation against an extensive set of experimental NMR methyl group residual dipolar couplings. Our results show a high level of consistency between the experimental data and the values predicted from the molecular dynamics trajectory reflecting a systematically improved performance of ff99SBnmr1-ILDN over the original ff99SB force field. Moreover, the unconstrained ff99SBnmr1-ILDN MD ensemble achieves a similar level of agreement as the recently introduced EROS ensemble, which was constructed based on a large body of NMR data as constraints, including the methyl residual dipolar couplings. This suggests that ff99SBnmr1-ILDN provides a high-quality representation of the motions of methyl-bearing protein side chains, which are sensitive probes of protein-protein and protein-ligand interactions.
Also flagged:ejaculation5-HT transporterpolymerase5-HTTLPR
Journal Article2011-08-01✓ 1 SnippetLuo SW, Wang F, Xie ZY, Huang XK, Lu YP.
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Abstract)
…polymorphism of the5-HTTwas detected by…
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<h4>Objective</h4>To investigate the relationship between 5-HT transporter gene-linked polymorphism (5-HTTPLR) and the clinical characters of premature ejaculation in Han Chinese population.<h4>Methods</h4>By case-control study approach, we set primary premature ejaculation (PPE) group (119 cases), secondary premature ejaculation (SPE) group (60 cases) with IELT < 1 min in more than 90% coitus and normal control group (90 cases) with IELT ≥ 3 min. The gene polymorphism of the 5-HTT was detected by polymerase chain reaction analysis in all the cases, and the gene frequency differences among the three groups were evaluated.<h4>Results</h4>The frequency of the genotype S/S was higher in PPE group than in normal control group(51.3% vs. 37.8%,P<0.01), and the frequency of genetype L/S was lower in PPE group than in normal vontrol group(28.6% vs. 34.4%,P<0.05).The S allele was higher in PPE group than in control group (P<0.05), but there was no difference between the SPE group and the normal control group.<h4>Conclusion</h4>The 5-HTTLPR polymorphism is associated with PPE, which shows that genetics may play an important role in the occurrence of PPE but not of SPE. The etiology of PPE and SPE is different.
Although the palmitoyl acyltransferase (PAT) zinc-finger DHHC containing 17 (zD17) has been implicated in genetic neurological disorders by regulating protein palmitoylation, the role of zD17 in acute brain injury remains unknown. Here, we report that zD17 contributes to acute ischemic brain injury via a mechanism independent of its PAT activity. We have found that zD17 directly interacts with c-Jun N terminus kinase (JNK) to form a signaling module for JNK activation. Pathological stressors induce the zD17-JNK interaction, which promotes downstream neuronal cell death signals. We have developed novel peptides targeting the JNK-interacting motif on zD17 to selectively block the enhancement of the zD17-JNK interaction and the activation of JNK isoforms 2 and 3. Application of these peptides successfully blocks JNK activation and neuronal cell death pathways, protects cultured neurons from excitotoxicity, and dramatically reduces brain damage and behavioral deficits in a rat model of focal ischemic stroke. Our findings indicate zD17 as a key player in ischemic stroke and suggest the potential therapeutic value of targeting the zD17-JNK interaction for acute brain injury.
Also flagged:atherosclerosisagingdiabetes mellituschronic kidney diseaseENPP1CD73
Journal Article2011-08-01✓ 1 SnippetRutsch F, Nitschke Y, Terkeltaub R.
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…DCC…
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Artery calcification reflects an admixture of factors such as ectopic osteochondral differentiation with primary host pathological conditions. We review how genetic factors, as identified by human genome-wide association studies, and incomplete correlations with various mouse studies, including knockout and strain analyses, fit into "pieces of the puzzle" in intimal calcification in human atherosclerosis, and artery tunica media calcification in aging, diabetes mellitus, and chronic kidney disease. We also describe in sharp contrast how ENPP1, CD73, and ABCC6 serve as "cogs in a wheel" of arterial calcification. Specifically, each is a minor component in the function of a much larger network of factors that exert balanced effects to promote and suppress arterial calcification. For the network to normally suppress spontaneous arterial calcification, the "cogs" ENPP1, CD73, and ABCC6 must be present and in working order. Monogenic ENPP1, CD73, and ABCC6 deficiencies each drive a molecular pathophysiology of closely related but phenotypically different diseases (generalized arterial calcification of infancy (GACI), pseudoxanthoma elasticum (PXE) and arterial calcification caused by CD73 deficiency (ACDC)), in which premature onset arterial calcification is a prominent but not the sole feature.
Also flagged:bone formationHydroxyaptitemetabolismmineralscalciumnitrate
Journal Article2011-08-01No SnippetsZhu W, Wang D, Zhang X, Lu W, Liu J, Peng L, Li H, Han Y, Zeng Y.
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The aim of our study was to validate the effect of radionuclide imaging in early monitoring of the bone's reconstruction, the animal model of bone defect was made on the rabbits repaired with HA artificial bone. The ability of bone defect repair was evaluated by using radionuclide bone imaging at 2, 4, 8 and 12 weeks postoperatively. The results indicate that the experimental group stimulated more bone formation than that of the control group. The differences of the bone reconstruction ability were statistically significant (p<0.05). The nano-HA artificial has good bone conduction, and it can be used for the treatment of bone defects. Radionuclide imaging may be an effective and first choice method for the early monitoring of the bone's reconstruction.
Also flagged:Hepcidinironpeptide hormoneiron-overload diseasemembranedegradation
Journal Article2011-08-01No SnippetsDe Domenico I, Ward DM, Kaplan J.
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Systemic iron homeostasis is regulated by the interaction of the peptide hormone, hepcidin and the iron exporter, ferroportin. Mutations in FPN1, the gene that encodes ferroportin, result in iron-overload disease that shows dominant inheritance and variation in phenotype. The inheritance of ferroportin-linked disorders can be explained by the finding that ferroportin is a multimer and the product of the mutant allele participates in multimer formation. The nature of the ferroportin mutant can explain the variation in phenotype, which is due to either decreased iron export activity or decreased ability to be downregulated by hepcidin. Iron export through ferroportin is determined by the concentration of ferroportin in plasma membrane, which is the result of both synthetic and degradation events. Ferroportin degradation can occur by hepcidin-dependent and hepcidin-independent internalization. Ferroportin expression is regulated transcriptionally and posttranslationally.
Hereditary hemochromatosis is a genetic disorder of iron overload. Over the past 15 years, significant advances have been made in understanding the molecular pathogenesis of this disorder. First, genetic studies linked this disorder to mutations in several genes, including HFE, transferrin receptor 2 ( TFR2), hepcidin ( HAMP), ferroportin ( SLC40A1), and hemojuvelin ( HFE2). Recent progress has generated significant insight into the function of these molecules in systemic iron homeostasis, and has revealed that despite the genetic and phenotypic diversity of hereditary hemochromatosis, there are common pathogenic mechanisms underlying this disease. The common downstream mechanism of iron overload in hereditary hemochromatosis is abnormal regulation of the hepcidin-ferroportin axis, leading to a failure to prevent excess iron from entering the circulation. Recent data are starting to unravel the molecular mechanisms by which iron regulates hepcidin production, and has demonstrated a key role for the bone morphogenetic protein-hemojuvelin-SMAD signaling pathway in this process. Future studies will be needed to more fully understand the molecular mechanisms of iron sensing and the roles of HFE and TFR2 in this process. Here, the authors review the current state of knowledge on the molecular pathogenesis of hereditary hemochromatosis.
…Natural history and management of HFE-hemochromatosis.…
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…Meticulous family and HLA association studies followed ultimately by cloning of the HFE gene have dramatically changed our understanding of the natural history and manifestations of HH.…
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…HFE-hemochromatosis…
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…and management ofHFE-hemochromatosis.…
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…and management of HFE-hemochromatosis.…
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Advances in our knowledge of hereditary hemochromatosis (HH) over the past 150 years have revealed new insights into this common genetic disorder. Meticulous family and HLA association studies followed ultimately by cloning of the HFE gene have dramatically changed our understanding of the natural history and manifestations of HH. Cross-sectional studies demonstrated that HH had a highly variable clinical and biochemical penetrance in susceptible individuals of northern European descent. "State-of-the-art" large longitudinal population studies have accurately defined the natural history. We now recognize that HH is not as discreet an entity as previously thought because genetic and environmental modifiers of disease penetrance are increasingly identified as influencing the clinical course of HH. While phlebotomy remains the cornerstone of therapy, our diagnostic approach has been refined to incorporate new biochemical, genetic, and noninvasive methods that complement more traditional approaches. This review aims to encapsulate this new knowledge in a framework that addresses commonly raised issues relating to the current natural history, diagnosis, and management of HH patients.
Also flagged:ironhemochromatosis syndromeshereditaryiron loading disorderssynthesistransferrin receptor 2
Journal Article2011-08-01✓ 5 SnippetsPietrangelo A, Caleffi A, Corradini E.
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…Yet, they are caused by pathogenic mutations in other genes, such as transferrin receptor 2 ( TFR2), hepcidin ( HAMP), hemojuvelin ( HJV) , and ferroportin ( FPN), and, unlike HFE-hemochromatosis, are not restricted to Caucasians.…
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…Non-HFE hepatic iron overload.…
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…Ferroportin disease, the most common non- HFE hereditary iron-loading disorder, is caused by a loss of iron export function of FPN resulting in early and preferential iron accumulation in Kupffer cells and macrophages with high ferritin levels and low-to-normal transferrin saturation.…
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…Non-HFEhepatic iron overload.…
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…The non-HFEhemochromatosis syndromes iden…
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Numerous clinical entities have now been identified to cause pathologic iron accumulation in the liver. Some are well described and have a verified hereditary basis; in others the genetic basis is still speculative, while in several cases nongenetic iron-loading factors are apparent. The non- HFE hemochromatosis syndromes identifies a subgroup of hereditary iron loading disorders that share with classic HFE-hemochromatosis, the autosomal recessive trait, the pathogenic basis (i.e., lack of hepcidin synthesis or activity), and key clinical features. Yet, they are caused by pathogenic mutations in other genes, such as transferrin receptor 2 ( TFR2), hepcidin ( HAMP), hemojuvelin ( HJV) , and ferroportin ( FPN), and, unlike HFE-hemochromatosis, are not restricted to Caucasians. Ferroportin disease, the most common non- HFE hereditary iron-loading disorder, is caused by a loss of iron export function of FPN resulting in early and preferential iron accumulation in Kupffer cells and macrophages with high ferritin levels and low-to-normal transferrin saturation. This autosomal dominant disorder has milder expressivity than hemochromatosis. Other much rarer genetic disorders are associated with hepatic iron load, but the clinical picture is usually dominated by symptoms and signs due to failure of other organs (e.g., anemia in atransferrinemia or neurologic defects in aceruloplasminemia). Finally, in the context of various necro-inflammatory or disease processes (i.e., chronic viral or metabolic liver diseases), regional or local iron accumulation may occur that aggravates the clinical course of the underlying disease or limits efficacy of therapy.
Also flagged:ubiquitin-related modifierUrm1lysineMOCS3E1-like proteinUba4
Journal Article2011-08-01No SnippetsWang F, Liu M, Qiu R, Ji C.
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The ubiquitin-related modifier Urm1 can be covalently conjugated to lysine residues of other proteins, such as yeast Ahp1 and human MOCS3, through a mechanism involving the E1-like protein Uba4 (MOCS3 in humans). Similar to ubiquitination, urmylation requires a thioester intermediate and forms isopeptide bonds between Urm1 and its substrates. In addition, the urmylation process can be significantly enhanced by oxidative stress. Recent findings have demonstrated that Urm1 also acts as a sulfur carrier in the thiolation of eukaryotic tRNA via a mechanism that requires the formation of a thiocarboxylated Urm1. This role is very similar to that of prokaryotic sulfur carriers such as MoaD and ThiS. Evidence strongly supports the hypothesis that Urm1 is the molecular fossil in the evolutionary link between prokaryotic sulfur carriers and eukaryotic ubiquitin-like proteins. In the present review, we discuss the dual role of Urm1 in protein and tRNA modification.
Also flagged:metabotropic glutamate receptor subtype 5fragile X syndromemGlu 5systemanxietygastresophageal reflux disease
Journal Article2011-08-01No SnippetsEmmitte KA.
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Negative allosteric modulators (NAMs) of metabotropic glutamate receptor subtype 5 (mGlu(5)) have remained attractive to researchers as potential therapies for a number of central nervous system related diseases, including anxiety, pain, gastroesophageal reflux disease (GERD), addiction, Parkinson's disease (PD), and fragile X syndrome (FXS). In addition to the many publications with supportive preclinical data with key tool molecules, recent positive reports from the clinic have bolstered the confidence in this approach. During the two year time span from 2009 through 2010, a number of new mGlu(5) NAM chemotypes have been disclosed and discussed in the primary and patent literature. A summary of several efforts representing many diverse chemotypes are presented here, along with a discussion of representative structure activity relationships (SAR) and synthetic approaches to the templates where possible.
Also flagged:liver fibrosisnonalcoholic steatohepatitisfattySteatosiscentral obesityaspartate aminotransferase
Journal Article2011-08-01✓ 1 SnippetUslusoy HS, Nak SG, Gülten M.
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…hemochromatosis…
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<h4>Aim</h4>To evaluate certain anthropometric, clinical and laboratory features indicating liver fibrosis in nonalcoholic steatohepatitis and to establish the noninvasive markers for liver fibrosis.<h4>Methods</h4>Eighty-one patients (40 male, 41 female) who were diagnosed with fatty liver by ultrasonographic examination and fulfilled the inclusion criteria participated in the study. Anamnesis, anthropometric, clinical and laboratory features of all cases were recorded and then liver biopsy was performed after obtaining patient consent. Steatosis, necroinflammation and liver fibrosis were examined according to age ≥ 45, gender, body mass index, central obesity, aspartate aminotransferase (AST)/alanine aminotransferase (ALT) > 1, γ-glutamyltransferase (GGT)/ALT > 1, platelet count, insulin, c-peptide levels and the presence of hypertension, diabetes, hypertriglyceridemia and insulin resistance.<h4>Results</h4>Eighty-one patients with non-alcoholic steatohepatitis (NASH) enrolled in the study. 69 of 81 patients were diagnosed with NASH, 11 were diagnosed with simple fatty liver and 1 was diagnosed with cirrhosis. AST/ALT > 1, GGT/ALT > 11, high serum ferritin and fasting insulin levels, the presence of diabetes, hypertension, hypertriglyceridemia and insulin resistance seemed to enhance the severity of steatosis, necroinflammation and fibrosis but these results were not statistically significant.<h4>Conclusion</h4>Liver steatosis and fibrosis can occur in individuals with normal weight. There was no significant concordance between severity of liver histology and the presence of predictors for liver fibrosis including metabolic risk factors.
Also flagged:Cancerbreast cancerrestriction enzymenucleotidepolymerasechromosomal segments
Journal Article2011-08-01No SnippetsHampton OA, Koriabine M, Miller CA, Coarfa C, Li J, Den Hollander P, Schoenherr C, Carbone L, Nefedov M, Ten Hallers BF, Lee AV, De Jong PJ, Milosavljevic A.
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Cancer genomes frequently undergo genomic instability resulting in accumulation of chromosomal rearrangement. To date, one of the main challenges has been to confidently and accurately identify these rearrangements by using short-read massively parallel sequencing. We were able to improve cancer rearrangement detection by combining two distinct massively parallel sequencing strategies: fosmid-sized (36 kb on average) and standard 5 kb mate pair libraries. We applied this combined strategy to map rearrangements in two breast cancer cell lines, MCF7 and HCC1954. We detected and validated a total of 91 somatic rearrangements in MCF7 and 25 in HCC1954, including genomic alterations corresponding to previously reported transcript aberrations in these two cell lines. Each of the genomes contains two types of breakpoints: clustered and dispersed. In both cell lines, the dispersed breakpoints show enrichment for low copy repeats, while the clustered breakpoints associate with high copy number amplifications. Comparing the two genomes, we observed highly similar structural mutational spectra affecting different sets of genes, pointing to similar histories of genomic instability against the background of very different gene network perturbations.
<h4>Aim</h4>To investigate genetics of two cases of colorectal tumor local recurrence and throw some light on the etiopathogenesis of anastomotic recurrence.<h4>Methods</h4>Two cases are presented: a 65-year-old female receiving two colonic resections for primary anastomotic recurrences within 21 mo, and a 57-year-old female undergoing two local excisions of recurrent anastomotic adenomas within 26 mo. A loss of heterozygosity (LOH) study of 25 microsatellite markers and a mutational analysis of genes BRAF, K-RAS and APC were performed in samples of neoplastic and normal colonic mucosa collected over the years.<h4>Results</h4>A diffuse genetic instability was present in all samples, including neoplastic and normal colonic mucosa. Two different patterns of genetic alterations (LOH at 5q21 and 18p11.23 in the first case, and LOH at 1p34 and 3p14 in the second) were found to be associated with carcinogenesis over the years. A role for the genes MYC-L (mapping at 1p34) and FIHT (mapping at 3p14.2) is suggested, whereas a role for APC (mapping at 5q21) is not shown.<h4>Conclusion</h4>The study challenges the most credited intraluminal implantation and metachronous carcinogenesis theories, and suggests a persistent, patient-specific alteration as the trigger of colorectal cancer anastomotic recurrence.
Also flagged:obesityFTOMC4RTMEM18GNPDA2pediatric obesity
Journal Article2011-08-01No SnippetsKlimentidis YC, Chen GB, López-Alarcón M, Harris JJ, Duarte CW, Fernández JR.
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<h4>Background and aims</h4>Genome-wide association studies (GWAS) have identified several loci that are associated with body mass index (BMI = kg/m(2)). However, little is known regarding whether the genetic basis of BMI differs among children of diverse racial/ethnic backgrounds, how the cumulative effect of these genes influences weight, or the contribution of these variants to body composition. This study examined the association between 17 GWAS-identified loci located in 16 genes and body-composition phenotypes in a multiethnic pediatric sample and evaluated the association of a composite genetic risk score with these phenotypes.<h4>Methods</h4>Anthropometric measures of BMI, waist circumference and waist-to-hip ratio were obtained in a sample of 298 children. Lean and fat mass were obtained from dual-energy X-ray absorptiometry (DXA). Genotypes of 17 single nucleotide polymorphisms (SNPs) were tested for association with the phenotypic measures, adjusted by standard covariates and estimates of genetic admixture.<h4>Results</h4>Both SNPs rs8050136 and rs9939609 in FTO were associated with BMI and waist circumference in a direction opposite to that observed among adults, and an inverse association was detected between the risk variant in MC4R and total lean body mass. Lean body mass mediated the association between TMEM18 and BMI. The association between the genetic risk score and body composition differed according to ethnic/racial classification.<h4>Conclusions</h4>Our findings suggest that genetic associations with BMI among children are different from those in adults, that some loci may operate through lean body mass, and that genetic risk scores will not have universal applicability across ethnic/racial groups.
…protists, less complexRNase IIIa-IIIbIIIa-IIIb- containing proteins…
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Epigenetics include DNA methylation, the modification of histone tails that affect chromatin states, and small RNAs that are involved in the setting and maintenance of chromatin modifications. Marine stramenopiles (MAS), which are a diverse assemblage of algae that acquired photosynthesis from secondary endosymbiosis, include single-celled organisms such as diatoms as well as multicellular forms such as brown algae. The recent publication of two diatom genomes that diverged ~90 million years ago (mya), as well as the one of a brown algae that diverged from diatoms ~250 Mya, provide a great system of related, yet diverged set of organisms to compare epigenetic marks and their relationships. For example, putative DNA methyltransferase homologues were found in diatoms while none could be identified in the brown algal genome. On the other hand, no canonical DICER-like protein was found in diatoms in contrast to what is observed in brown algae. A key interest relies in understanding the adaptive nature of epigenetics and its inheritability. In contrast to yeast that lack DNA methylation, homogeneous cultures of diatoms constitute an attractive system to study epigenetic changes in response to environmental conditions such as nutrient-rich to nutrient-poor transitions which is especially relevant because of their ecological importance. P. tricornutum is also of outstanding interest because it is observed as three different morphotypes and thus constitutes a simple and promising model for the study of the epigenetic phenomena that accompany cellular differentiation. In this review we focus on the insights obtained from MAS comparative genomics and epigenomic analyses.
Also flagged:gadoliniumwaterbrain tumorselectronscarbonatehydroxide
Journal Article2011-08-01No SnippetsFrullano L, Caravan P.
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The development of gadolinium chelators that can be easily and readily linked to various substrates is of primary importance for the development high relaxation efficiency and/or targeted magnetic resonance imaging (MRI) contrast agents. Over the last 25 years a large number of bifunctional chelators have been prepared. For the most part, these compounds are based on ligands that are already used in clinically approved contrast agents. More recently, new bifunctional chelators have been reported based on complexes that show a more potent relaxation effect, faster complexation kinetics and in some cases simpler synthetic procedures. This review provides an overview of the synthetic strategies used for the preparation of bifunctional chelators for MRI applications.
We report a case of CPPD crowned dens syndrome in an 87 year white old male with a known history of pseudogout, with clinical and radiological features characteristic of this syndrome. Interestingly, there was significant mass effect on the clivus, with clivus erosion and destruction, a finding that has not previously been described with this syndrome. The clinical and radiological characteristics of Crowned Dens syndrome, as well as CPPD are reviewed. We suggest that CPPD crowned dens syndrome may be included in the differential diagnosis when clivus destruction or erosion, in association with a soft tissue mass with calcification, is seen.
Also flagged:CysteineSynthesisbiosynthesiscysteine-dependent enzymeReductasesphosphine
Journal Article2011-08-01No SnippetsDermenci A, Selig PS, Domaoal RA, Spasov KA, Anderson KS, Miller SJ.
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Cysteine plays a number of important functional and structural roles in Nature, often in the realm of catalysis. Herein, we present an example of a cysteine-catalyzed Rauhut-Currier reaction for a potentially biomimetic synthesis of Sch-642305 and related analogs. In this key step of the synthesis we discuss interesting new discoveries and the importance of substrate-catalyst recognition, as well as cysteine's structural features. Also, we investigate the activity of Sch-642305 and four analogs in HIV-infected T-cells.