Also flagged:serotonin transporteranxietydepressive disordersAdolescent AnxietyMajor Depressive Disorderanxiety disorder
Journal Article2008-10-31✓ 4 SnippetsLau JY, Goldman D, Buzas B, Fromm SJ, Guyer AE, Hodgkinson C, Monk CS, Nelson EE, Shen PH, Pine DS, Ernst M.
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…Contrary findings of increased activation in patients with L(A)L(A) relative to the S or L(G) alleles require further exploration.…
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…Amygdala function and 5-HTT gene variants in adolescent anxiety and major depressive disorder.…
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…Amygdala function and5-HTTgene variants in…
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<h4>Background</h4>Associations between a functional polymorphism in the serotonin transporter gene and amygdala activation have been found in healthy, depressed, and anxious adults. This study explored these gene-brain associations in adolescents by examining predictive effects of serotonin transporter gene variants (S and L(G) allele carriers vs. L(A) allele homozygotes) and their interaction with diagnosis (healthy vs. patients) on amygdala responses to emotional faces.<h4>Methods</h4>Functional magnetic resonance data were collected from 33 healthy adolescents (mean age: 13.71, 55% female) and 31 medication-free adolescents with current anxiety or depressive disorders (or both; mean age: 13.58, 56% female) while viewing fearful, angry, happy, and neutral facial expressions under varying attention states.<h4>Results</h4>A significant three-way genotype-by-diagnosis-by-face-emotion interaction characterized right amygdala activity while subjects monitored internal fear levels. This interaction was decomposed to map differential gene-brain associations in healthy and affected adolescents. First, consistent with healthy adult data, healthy adolescents with at least one copy of the S or L(G) allele showed stronger amygdala responses to fearful faces than healthy adolescents without these alleles. Second, patients with two copies of the L(A) allele exhibited greater amygdala responses to fearful faces relative to patients with S or L(G) alleles. Third, although weaker, genotype differences on amygdala responses in patients extended to happy faces. All effects were restricted to the fear-monitoring attention state.<h4>Conclusions</h4>S/L(G) alleles in healthy adolescents, as in healthy adults, predict enhanced amygdala activation to fearful faces. Contrary findings of increased activation in patients with L(A)L(A) relative to the S or L(G) alleles require further exploration.
The Giardia lamblia cyst wall is required for survival outside the host and infection. Three cyst wall protein (cwp) genes identified to date are highly up-regulated during encystation. However, little is known of the molecular mechanisms governing their gene regulation. Messenger RNAs containing premature stop codons are rapidly degraded by a nonsense-mediated mRNA decay (NMD) system to avoid production of non-functional proteins. In addition to RNA surveillance, NMD also regulates thousands of naturally occurring transcripts through a variety of mechanisms. It is interesting to know the NMD pathway in the primitive eukaryotes. Previously, we have found that the giardial homologue of a conserved NMD factor, UPF1, may be functionally conserved and involved in NMD and in preventing nonsense suppression. In this study, we tested the hypothesis that NMD factors can regulate some naturally occurring transcripts in G. lamblia. We found that overexpression of UPF1 resulted in a significant decrease of the levels of CWP1 and cyst formation and of the endogenous cwp1-3, and myb2 mRNA levels and stability. This indicates that NMD could contribute to the regulation of the cwp1-3 and myb2 transcripts, which are key to G. lamblia differentiation into cyst. Interestingly, we also found that UPF1 may be involved in regulation of eight other endogenous genes, including up-regulation of the translation elongation factor gene, whose product increases translation which is required for NMD. Our results indicate that NMD factor could contribute to the regulation of not only nonsense containing mRNAs, but also mRNAs of the key encystation-induced genes and other endogenous genes in the early-diverging eukaryote, G. lamblia.
Condensin is a 5 subunit complex that plays an important role in the structure of chromosomes during mitosis. It is known that phosphorylation of condensin subunits by cdc2/cyclin B at the beginning of mitosis is important for condensin activity, but the sites of these phosphorylation events have not been identified nor has their role in regulating condensin function. Here we identify two threonine residues in the CAP-G subunit of condensin, threonines 308 and 332, that are targets of cdc2/cyclin B phosphorylation. Mutation of these threonines to alanines results in defects in CAP-G localization with chromosomes during mitosis. These results are the first to identify phosphorylation sites within the condensin complex that regulate condensin localization with chromosomal DNA.
Also flagged:XIAPc-myccDNAgene expressionribosomeprotein synthesis
Journal Article2008-10-31✓ 5 SnippetsKazadi K, Loeuillet C, Deutsch S, Ciuffi A, Muñoz M, Beckmann JS, Moradpour D, Antonarakis SE, Telenti A.
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…intron 1 ofDCC(deleted in colorectal…
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…1 of theDCCgene on chromosome…
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…intron 1 ofDCC.…
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…size of theDCCgene, these results…
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…DCC, a human receptor…
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Variation in cellular gene expression levels has been shown to be inherited. Expression is controlled at transcriptional and post-transcriptional levels. Internal ribosome entry sites (IRES) are used by viruses to bypass inhibition of cap-dependent translation, and by eukaryotic cells to control translation under conditions when protein synthesis is inhibited. We aimed at identifying genomic determinants of variability in IRES-mediated translation of viral [Encephalomyocarditis virus (EMCV)] and cellular IRES [X-linked inhibitor-of-apoptosis (XIAP) and c-myc]. Bicistronic lentiviral constructs expressing two fluorescent reporters were used to transduce laboratory and B lymphoblastoid cell lines [15 CEPH pedigrees (n = 205) and 50 unrelated individuals]. IRES efficiency varied according to cell type and among individuals. Control of IRES activity has a significant genetic component (h(2) of 0.47 and 0.36 for EMCV and XIAP, respectively). Quantitative linkage analysis identified a suggestive locus (LOD 2.35) on chromosome 18q21.2, and genome-wide association analysis revealed of a cluster of SNPs on chromosome 3, intronic to the FHIT gene, marginally associated (P = 5.9E-7) with XIAP IRES function. This study illustrates the in vitro generation of intermediate phenotypes by using cell lines for the evaluation of genetic determinants of control of elements such as IRES.
Also flagged:retinal dystrophiesgene expressionoxygenreverse transcriptiondeathphotoreceptor dystrophies
Journal Article2008-10-31✓ 1 SnippetNatoli R, Provis J, Valter K, Stone J.
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…(10.42), C4 (5.41),Serpinc1(21.65), and Serping1…
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<h4>Purpose</h4>Hyperoxia is specifically toxic to photoreceptors, and this toxicity may be important in the progress of retinal dystrophies. This study examines gene expression induced in the C57BL/6J mouse retina by hyperoxia over the 14-day period during which photoreceptors first resist, then succumb to, hyperoxia.<h4>Methods</h4>Young adult C57BL/6J mice were exposed to hyperoxia (75% oxygen) for up to 14 days. On day 0 (control), day 3, day 7, and day 14, retinal RNA was extracted and processed on Affymetrix GeneChip Mouse Genome 430 2.0 arrays. Microarray data were analyzed using GCOS Version 1.4 and GeneSpring Version 7.3.1. For 15 genes, microarray data were confirmed using relative quantitative real-time reverse transcription polymerase chain reaction techniques.<h4>Results</h4>The overall numbers of hyperoxia-regulated genes increased monotonically with exposure. Within that increase, however, a distinctive temporal pattern was apparent. At 3 days exposure, there was prominent upregulation of genes associated with neuroprotection. By day 14, these early-responsive genes were downregulated, and genes related to cell death were strongly expressed. At day 7, the regulation of these genes was mixed, indicating a possible "transition period" from stability at day 3 to degeneration at day 14. When functional groupings of genes were analyzed separately, there was significant regulation in genes responsive to stress, genes known to cause human photoreceptor dystrophies and genes associated with apoptosis.<h4>Conclusions</h4>Microarray analysis of the response of the retina to prolonged hyperoxia demonstrated a temporal pattern involving early neuroprotection and later cell death, and provided insight into the mechanisms involved in the two phases of response. As hyperoxia is a consistent feature of the late stages of photoreceptor degenerations, understanding the mechanisms of oxygen toxicity may be important therapeutically.
The Rho family of small GTPases has been implicated in many neurological disorders including mental retardation, but whether they are involved in primary microcephaly (microcephalia vera) is unknown. Here, we examine the role of Rac1 in mammalian neural progenitors and forebrain development by a conditional gene-targeting strategy using the Foxg1-Cre line to delete floxed-Rac1 alleles in the telencephalic ventricular zone (VZ) of mouse embryos. We found that Rac1 deletion in the telencephalic VZ progenitors resulted in reduced sizes of both the striatum and cerebral cortex. Analyses further indicated that this abnormality was caused by accelerated cell-cycle exit and increased apoptosis during early corticogenesis (approximately E14.5), leading to a decrease of the neural progenitor pool in mid-to-late telencephalic development (E16.5 to E18.5). Moreover, the formation of patch-matrix compartments in the striatum was impaired by Rac1-deficiency. Together, these results suggest that Rac1 regulates self-renewal, survival, and differentiation of telencephalic neural progenitors, and that dysfunctions of Rac1 may lead to primary microcephaly.
This tutorial review is aimed at chemical scientists interested in understanding and exploiting the remarkable catalytic behavior of the hydrogenases. The key structural features are analyzed for the active sites of the two most important hydrogenases. Reactivity is emphasized, focusing on mechanism and catalysis. Through this analysis, gaps are identified in the synthesis of functional replicas of these fascinating and potentially useful enzymes.
Also flagged:Netrin-1fibronectinaxoncell migrationtumorangiogenesis
Journal Article2008-10-31✓ 4 SnippetsLee HK, Seo IA, Shin YK, Lee SH, Seo SY, Suh DJ, Park HT.
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…Recent studies revealed that netrins perform novel functions in such processes as epithelial development and angiogenesis without operating through the classical netrin receptors, DCC (Deleted in Colorectal Cancer) and Unc5h.…
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…classical netrin receptors,DCC(Deleted in Colorectal…
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…not by an anti-DCCor anti-Unc5h antibody.…
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Netrins are secreted molecules and involved in axon guidance, cell migration and tumor development. Recent studies revealed that netrins perform novel functions in such processes as epithelial development and angiogenesis without operating through the classical netrin receptors, DCC (Deleted in Colorectal Cancer) and Unc5h. In the present study, we investigated the roles of netrin-1 and its receptors in cell spreading of human glioblastoma cells, and found that netrin-1 haptotactically enhanced fibronectin-induced cell spreading and focal adhesion formation in U373 glioblastoma cells. Netrin-1 binding to the U373 cell membrane was blocked by an antibody against alphav integrin subunit, but not by an anti-DCC or anti-Unc5h antibody. In addition, enhancement of the fibronectin response by netrin-1 was abrogated by a function blocking antibody against integrin alphavbeta3. Since the alphav subunit of the integrin family plays an important role in the pathophysiological aspects of cell migration, including tumor angiogenesis and metastasis, our data provide important insight into the molecular mechanism of netrin function.
Also flagged:ribosomecell adhesionTCP-1chaperoninlymphomaresponse to
Journal Article2008-10-30✓ 1 SnippetRogers S, Girolami M, Kolch W, Waters KM, Liu T, Thrall B, Wiley HS.
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<h4>Motivation</h4>Modern transcriptomics and proteomics enable us to survey the expression of RNAs and proteins at large scales. While these data are usually generated and analyzed separately, there is an increasing interest in comparing and co-analyzing transcriptome and proteome expression data. A major open question is whether transcriptome and proteome expression is linked and how it is coordinated.<h4>Results</h4>Here we have developed a probabilistic clustering model that permits analysis of the links between transcriptomic and proteomic profiles in a sensible and flexible manner. Our coupled mixture model defines a prior probability distribution over the component to which a protein profile should be assigned conditioned on which component the associated mRNA profile belongs to. We apply this approach to a large dataset of quantitative transcriptomic and proteomic expression data obtained from a human breast epithelial cell line (HMEC). The results reveal a complex relationship between transcriptome and proteome with most mRNA clusters linked to at least two protein clusters, and vice versa. A more detailed analysis incorporating information on gene function from the Gene Ontology database shows that a high correlation of mRNA and protein expression is limited to the components of some molecular machines, such as the ribosome, cell adhesion complexes and the TCP-1 chaperonin involved in protein folding.<h4>Availability</h4>Matlab code is available from the authors on request.
Also flagged:TMPRSS6irontransmembraneserine proteasematriptase-2anemia
Journal Article2008-10-30✓ 2 SnippetsSilvestri L, Pagani A, Nai A, De Domenico I, Kaplan J, Camaschella C.
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The liver peptide hepcidin regulates body iron, is upregulated in iron overload and inflammation, and is downregulated in iron deficiency/hypoxia. The transmembrane serine protease matriptase-2 (TMPRSS6) inhibits the hepcidin response and its mutational inactivation causes iron-deficient anemia in mice and humans. Here we confirm the inhibitory effect of matriptase-2 on hepcidin promoter; we show that matriptase-2 lacking the serine protease domain, identified in the anemic Mask mouse (matriptase-2(MASK)), is fully inactive and that mutant R774C found in patients with genetic iron deficiency has decreased inhibitory activity. Matriptase-2 cleaves hemojuvelin (HJV), a regulator of hepcidin, on plasma membrane; matriptase-2(MASK) shows no cleavage activity and the human mutant only partial cleavage capacity. Matriptase-2 interacts with HJV through the ectodomain since the interaction is conserved in matriptase-2(MASK). The expression of matriptase-2 mutants in zebrafish results in anemia, confirming the matriptase-2 role in iron metabolism and its interaction with HJV.
Ovarian hormones influence memory formation by eliciting changes in neural activity. The effects of various concentrations of progesterone (P4) on synaptic transmission and plasticity associated with long-term potentiation (LTP) and long-term depression (LTD) were studied using in vitro hippocampal slices. Extracellular studies show that the highest concentration of P4 tested (10(-6) M) decreased the baseline synaptic transmission and magnitude of LTP, but did not affect LTD. Intracellular studies suggest the P4 effect to be mediated, at least in part, by GABA(A) activity. These results establish a general effect of P4 on synaptic transmission, multiple forms of synaptic plasticity, and a possible mechanism of P4 action in hippocampus.
Also flagged:transferrin receptorcentral obesityhereditary hemochromatosishyperferritinemiasTfRiron
Journal Article2008-10-30✓ 4 SnippetsFreixenet N, Remacha A, Berlanga E, Caixàs A, Giménez-Palop O, Blanco-Vaca F, Bach V, Baiget M, Sánchez Y, Félez J, González-Clemente JM.
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Abstract)
…75 men (age: 55.4+/-12.4 years) with hyperferritinemia (serum ferritin--SF > 200 microg/L) and no known conditions of iron overload were evaluated for body mass index (BMI), waist circumference (WC), blood pressure, traditional indices of iron status, sTfR, fasting plasma glucose, lipid profile, insulin resistance (HOMA-IR), highly-sensitive C-reactive protein, hepatic enzymes and HFE gene mutations of HH.…
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…75 men (age: 5…
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…insulin resistance (HOMA-IR), highly-sensitive C-reactive protein, hepatic enzymes and HFE…
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…hepatic enzymes andHFEgene mutations of…
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<h4>Background</h4>A decrease in the serum concentrations of the soluble transferrin receptor (sTfR) is considered a good index of tissue iron. Because obesity is associated with hyperferritinemia and this is considered a sign of iron overload, a decrease in sTfR would be expected for the obese. We evaluated whether obese men with hyperferritinemia, detected in a genetic screening programme for hereditary hemochromatosis (HH), have lower serum concentrations of sTfR than their non-obese counterparts.<h4>Methods</h4>75 men (age: 55.4+/-12.4 years) with hyperferritinemia (serum ferritin--SF > 200 microg/L) and no known conditions of iron overload were evaluated for body mass index (BMI), waist circumference (WC), blood pressure, traditional indices of iron status, sTfR, fasting plasma glucose, lipid profile, insulin resistance (HOMA-IR), highly-sensitive C-reactive protein, hepatic enzymes and HFE gene mutations of HH.<h4>Results</h4>sTfR correlated with BMI (r=0.289; p=0.014) and with WC (r=0.420; p<0.001). Thirty-two subjects were obese (BM > or = 30 kg/m(2)) and had a significantly higher sTfR (2.95 (2.22-3.28) vs 2.28 (1.88-2.91) mg/L; p=0.013), hemoglobin (157+/-12 vs 152+/-11 gr/L; p=0.049) and HOMA-IR (1.38 (1.04-2.69) vs 1.02 (0.60-1.55) mg/L; p=0.009) than the non-obese. WC explained separately more variability of the sTfR than BMI (r(2)=0.177; p=0.002 and r=0.077; p=0.042, respectively), after adjusting for potential confounders.<h4>Conclusion</h4>An increase in serum concentrations of sTfR is associated with central obesity in men with hyperferritinemia.
Melanotan II is a synthetic cyclic heptapeptide used to prevent a sunlight-induced skin cancer by stimulating the skin tanning process. In this paper we report the first solution phase synthesis of the title compound. The hexapeptide sequence has been assembled by [(2+2)+1+1] scheme. After removing the orthogonal protection, a carbodiimide mediated lactamization, involving the epsilon-amino group of lysine and gamma-carboxy group of aspartic acid, led to a cyclic intermediate. Appending N-acetylnorleucine concluded the assembly of melanotan II molecule. Protection of the lateral groups in arginine and tryptophan was omitted for atom and step economy reasons. The total synthesis of melanotan II was accomplished in 12 steps with 2.6% overall yield, affording >90% pure peptide without using preparative chromatography.
Also flagged:fluoxetinedehydroepiandrosteronecell proliferationbrain-derived neurotrophic factorBDNFgene expression
Journal Article2008-10-30No SnippetsPinnock SB, Lazic SE, Wong HT, Wong IH, Herbert J.
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The 5-HT re-uptake inhibitor (SSRI) fluoxetine and the adrenal hormone dehydroepiandrosterone (DHEA) both increase the proliferation of progenitor cells in the adult hippocampus and also have antidepressant activity. This paper explores the combined ability of fluoxetine and DHEA to affect this process in the dentate gyrus of adult rats. We show that DHEA can render an otherwise ineffective dose of fluoxetine (2.5 mg/kg) able to increase progenitor cell proliferation to the same extent as doses four times higher (10 mg/kg). This synergistic action does not appear to be mediated by alterations in brain-derived neurotrophic factor (BDNF) gene expression; or by TrkB, mineralocorticoid, glucocorticoid, or 5-HT (5HT1A) receptor expression in the dentate gyrus; or by altered levels of plasma corticosterone. In a second experiment, the synergism between DHEA and fluoxetine was replicated. Furthermore, flattening the diurnal rhythm of plasma corticosterone by implanting additional corticosterone pellets s.c. prevented the effect of fluoxetine on progenitor cell division. This was not overcome by simultaneous treatment with DHEA, despite the latter's reported anti-glucocorticoid actions. The cellular mechanism for the potentiating action of DHEA on the pro- proliferative effects of fluoxetine in the adult hippocampus remains to be revealed. Since altered neurogenesis has been linked to the onset or recovery from depression, one consequence of these results is to suggest DHEA as a useful adjunct therapy for depression.
Also flagged:macrocyclessynthesismacrocyclebindingRNA polymerases 1ribosome
Journal Article2008-10-29No SnippetsTse BN, Snyder TM, Shen Y, Liu DR.
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DNA-templated organic synthesis enables the translation, selection, and amplification of DNA sequences encoding synthetic small-molecule libraries. Previously we described the DNA-templated multistep synthesis and model in vitro selection of a pilot library of 65 macrocycles. In this work, we report several key developments that enable the DNA-templated synthesis of much larger (>10,000-membered) small-molecule libraries. We developed and validated a capping-based approach to DNA-templated library synthesis that increases final product yields, simplifies the structure and preparation of reagents, and reduces the number of required manipulations. To expand the size and structural diversity of the macrocycle library, we augmented the number of building blocks in each DNA-templated step from 4 to 12, selected 8 different starting scaffolds which result in 4 macrocycle ring sizes and 2 building-block orientations, and confirmed the ability of the 36 building blocks and 8 scaffolds to generate DNA-templated macrocycle products. We computationally generated and experimentally validated an expanded set of codons sufficient to support 1728 combinations of step 1, step 2, and step 3 building blocks. Finally, we developed new high-resolution LC/MS analysis methods to assess the quality of large DNA-templated small-molecule libraries. Integrating these four developments, we executed the translation of 13,824 DNA templates into their corresponding small-molecule macrocycles. Analysis of the resulting libraries is consistent with excellent (>90%) representation of desired macrocycle products and a stringent test of sequence specificity suggests a high degree of sequence fidelity during translation. The quality and structural diversity of this expanded DNA-templated library provides a rich starting point for the discovery of functional synthetic small-molecule macrocycles.
Also flagged:hepatocellular-carcinomainfectionProtein phosphatase 3PPP3R1fibroblast growth factor receptor 1FGFR1
Journal Article2008-10-29No SnippetsZekri AR, Hafez MM, Bahnassy AA, Hassan ZK, Mansour T, Kamal MM, Khaled HM.
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<h4>Background</h4>Hepatocellular carcinoma (HCC) is a preventable disease rather than a curable one, since there is no well-documented effective treatment modality until now, making the molecular study of this disease mandatory.<h4>Findings</h4>We studied gene expression profile of 17 Egyptian HCC patients associated with HCV genotype-4 infection by c-DNA microarray. Out of the 15,660 studied genes, 446 were differentially expressed; 180 of them were up regulated and 134 were down regulated. Seventeen genes out of the 180 up-regulated genes are involved in 28 different pathways. Protein phosphatase 3 (PPP3R1) is involved in 10 different pathways followed by fibroblast growth factor receptor 1 (FGFR1), Cas-Br-M ecotropic retroviral transforming sequence b (CBLB), spleen tyrosine kinase (SYK) involved in three pathways; bone morphogenetic protein 8a (BMP8A), laminin alpha 3 (LAMA3), cell division cycle 23 (CDC23) involved in 2 pathways and NOTCH4 which regulate Notch signaling pathway. On the other hand, 25 out of the 134 down-regulated genes are involved in 20 different pathways. Integrin alpha V alpha polypeptide antigen CD51 (ITGVA) is involved in 4 pathways followed by lymphotoxin alpha (TNF superfamily, member 1) (LTA) involved in 3 pathways and alpha-2-macroglobulin (A2M), phosphorylase kinase alpha 2-liver (PHKA2) and MAGI1 membrane associated guanylate kinase 1 (MAGI1) involved in 2 pathways. In addition, 22 genes showed significantly differential expression between HCC cases with cirrhosis and without cirrhosis. Confirmation analysis was performed on subsets of these genes by RT-PCR, including some up-regulated genes such as CDK4, Bax, NOTCH4 and some down-regulated genes such as ISGF3G, TNF, and VISA.<h4>Conclusion</h4>This is the first preliminary study on gene expression profile in Egyptian HCC patients associated with HCV-Genotype-4 using the cDNA microarray. The identified genes could provide a new gate for prognostic and diagnostic markers for HCC associated with HCV. They could also be used to identify candidate genes for molecular target therapy.
Also flagged:gene expressionadenomacarcinomatumorrectal tumorschromosomes
Journal Article2008-10-29✓ 2 SnippetsLips EH, van Eijk R, de Graaf EJ, Oosting J, de Miranda NF, Karsten T, van de Velde CJ, Eilers PH, Tollenaar RA, van Wezel T, Morreau H.
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…SMAD2, SMAD4 and DCC are indicated as the prominent tumor suppressor genes on 18q [30,37].…
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…SMAD2, SMAD4 andDCCare indicated as…
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<h4>Background</h4>Accurate staging of rectal tumors is essential for making the correct treatment choice. In a previous study, we found that loss of 17p, 18q and gain of 8q, 13q and 20q could distinguish adenoma from carcinoma tissue and that gain of 1q was related to lymph node metastasis. In order to find markers for tumor staging, we searched for candidate genes on these specific chromosomes.<h4>Methods</h4>We performed gene expression microarray analysis on 79 rectal tumors and integrated these data with genomic data from the same sample series. We performed supervised analysis to find candidate genes on affected chromosomes and validated the results with qRT-PCR and immunohistochemistry.<h4>Results</h4>Integration of gene expression and chromosomal instability data revealed similarity between these two data types. Supervised analysis identified up-regulation of EFNA1 in cases with 1q gain, and EFNA1 expression was correlated with the expression of a target gene (VEGF). The BOP1 gene, involved in ribosome biogenesis and related to chromosomal instability, was over-expressed in cases with 8q gain. SMAD2 was the most down-regulated gene on 18q, and on 20q, STMN3 and TGIF2 were highly up-regulated. Immunohistochemistry for SMAD4 correlated with SMAD2 gene expression and 18q loss.<h4>Conclusion</h4>On basis of integrative analysis this study identified one well known CRC gene (SMAD2) and several other genes (EFNA1, BOP1, TGIF2 and STMN3) that possibly could be used for rectal cancer characterization.
Also flagged:neurotransmitter transportersserotoninamine transportersnorepinephrinedopamineSERT
Journal Article2008-10-29✓ 1 SnippetDaws LC.
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Biogenic amine transporters for serotonin, norepinephrine and dopamine (SERT, NET and DAT respectively), are the key players terminating transmission of these amines in the central nervous system by their high-affinity uptake. They are also major targets for many antidepressant drugs. Interestingly however, drugs targeted to a specific transporter do not appear to be as clinically efficacious as those that block two or all three of these transporters. A growing body of literature, reviewed here, supports the idea that promiscuity among these transporters (the uptake of multiple amines in addition to their "native" transmitter) may account for improved therapeutic effects of dual and triple uptake blockers. However, even these drugs do not provide effective treatment outcomes for all individuals. An emerging literature suggests that "non-traditional" transporters such as organic cation transporters (OCT) and the plasma membrane monoamine transporter (PMAT) may contribute to the less than hoped for efficacy of currently prescribed uptake inhibitors. OCT and PMAT are capable of clearing biogenic amines from extracellular fluid and may serve to buffer the effects of frontline antidepressants, such as selective serotonin reuptake inhibitors. In addition, polymorphisms that occur in the genes encoding the transporters can lead to variation in transporter expression and function (e.g. the serotonin transporter linked polymorphic region; 5-HTTLPR) and can have profound effects on treatment outcome. This may be accounted for, in part, by compensatory adaptations in other transporters. This review synthesizes the existing literature, focusing on serotonin to illustrate and revive a model for the rationale design of improved antidepressants.
The dominant gain-of-function polyglutamine repeat diseases, in which the initiating mutation is known, allow development of models that recapitulate many aspects of human disease. To the extent that pathology is a consequence of disrupted fundamental cellular activities, one can effectively study strategies to ameliorate or protect against these cellular insults. Model organisms allow one to identify pathways that affect disease onset and progression, to test and screen for pharmacological agents that affect pathogenic processes, and to validate potential targets genetically as well as pharmacologically. Here, we describe polyglutamine repeat diseases that have been modeled in a variety of organisms, including worms, flies, mice, and non-human primates, and discuss examples of how they have broadened the therapeutic landscape.
Also flagged:calcium phosphatebiomineralizationpeptidedentin matrix protein 1DMP1hydroxylapatite
Journal Article2008-10-28No SnippetsTsuji T, Onuma K, Yamamoto A, Iijima M, Shiba K.
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An animal's hard tissue is mainly composed of crystalline calcium phosphate. In vitro, small changes in the reaction conditions affect the species of calcium phosphate formed, whereas, in vivo, distinct types of crystalline calcium phosphate are formed in a well-controlled spatiotemporal-dependent manner. A variety of proteins are involved in hard-tissue formation; however, the mechanisms by which they regulate crystal growth are not yet fully understood. Clarification of these mechanisms will not only lead to the development of new therapeutic regimens but will also provide guidance for the application of biomineralization in bionanotechnology. Here, we focused on the peptide motifs present in dentin matrix protein 1 (DMP1), which was previously shown to enhance hydroxylapatite (HAP) formation when immobilized on a glass substrate. We synthesized a set of artificial proteins composed of combinatorial arrangements of these motifs and successfully obtained clones that accelerated formation of HAP without immobilization. Time-resolved static light-scattering analyses revealed that, in the presence of the protein, amorphous calcium phosphate (ACP) particles increased their fractal dimension and molecular mass without increasing their gyration radii during a short period before precipitation. The protein thus facilitated reorganization of the internal structure of amorphous particles into ordered crystalline states, i.e., the direct transformation of ACP to HAP, thereby acting as a nucleus for precipitation of crystalline calcium phosphate. Without the protein, the fractal dimension, molecular mass, and gyration radii of ACP particles increased concurrently, indicating heterogeneous growth transformation.
Also flagged:Hyperferritinemiainsulin resistancefattyhereditary hemochromatosismetabolic syndromeiron
Journal Article2008-10-28✓ 5 SnippetsBrudevold R, Hole T, Hammerstrøm J.
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Methods)
…Hence 34 patients (33males, 1 female) had no hfe-mutation known to predispose for hemochromatosis (neither homozygous for C282Y nor compound heterozygous, i.e. heterozygous for both C282Y and H63D) and was further examined to reveal other causes for hyperferritinemia.…
Introduction)
…The hemochromatosis-associated genotype (homozygous C282Y mutation of the hfe- gene) is found in about 85% of patients with hereditary hemochromatosis [3].…
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…but without thehemochromatosis-predisposing gene mutations.…
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…referred for suspectedhemochromatosison the basis…
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…Hemochromatosisis a disease…
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<h4>Objective</h4>During the last 10 years we have experienced an increasing number of referrals due to hyperferritinemia. This is probably due to increased awareness of hereditary hemochromatosis, and the availability of a genetic test for this condition. Most of these referred patients were over-weight middle-aged men with elevated ferritin levels, but without the hemochromatosis-predisposing gene mutations. We evaluated the relationship between hyperferritinemia and the metabolic syndrome in 40 patients.<h4>Methods</h4>Forty consecutive patients referred for hyperferritinemia were investigated. The examination programme included medical history, clinical investigation and venous blood samples drawn after an overnight fast. This resulted in 34 patients with unexplained hyperferritinemia, which were further examined. Liver biopsy was successfully performed in 29 subjects. Liver iron stores were assessed morphologically, and by quantitative phlebotomy in 16 patients.<h4>Results</h4>The majority of the patients had markers of the metabolic syndrome, and 18 patients (52%) fulfilled the IDF-criteria for the metabolic syndrome. Mean body mass index was elevated (28.8+/-4.2), mean diastolic blood pressure was 88.5+/-10.5 mmHg, and mean fasting insulin C-peptide 1498+/-539 pmol/l. Liver histology showed steatosis and nuclear glycogen inclusions in most patients (19 out of 29). Only four patients had increased iron stores by histology, of which two could be explained by alcohol consumption. Fourteen of 16 patients normalized ferritin levels after phlebotomy of a cumulative blood amount corresponding to normal iron stores. Ferritin levels were significantly related to insulin C-peptide level (p<0.002) and age (p<0.002).<h4>Conclusion</h4>The present results suggest that liver steatosis and insulin resistance but not increased iron load is frequently seen in patients referred for suspected hemochromatosis on the basis of hyperferritinemia. The ferritin level seems to be positively associated to insulin resistance.
Also flagged:JNKHuntington's diseaseHDneurodegenerative disorderglutaminec-Jun N-terminal kinase
Journal Article2008-10-28✓ 4 SnippetsPerrin V, Dufour N, Raoul C, Hassig R, Brouillet E, Aebischer P, Luthi-Carter R, Déglon N.
In-Text Gene Mentions
Abstract)
…Huntington's disease (HD) is a neurodegenerative disorder resulting from the expansion of a glutamine repeat (polyQ) in the N-terminus of the huntingtin (htt) protein.…
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…resulting from the expansion of a glutamine repeat ( polyQ ) in the N-terminus of the huntingtin ( htt ) protein. Expression of polyQ-containing proteins has been previously…
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…of the huntingtin (htt) protein.…
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…formation of EM48-positivehttinclusions and P-c-Jun…
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Huntington's disease (HD) is a neurodegenerative disorder resulting from the expansion of a glutamine repeat (polyQ) in the N-terminus of the huntingtin (htt) protein. Expression of polyQ-containing proteins has been previously shown to induce various cellular stress responses. Among these, activation of the c-Jun N-terminal kinase (JNK) cascade has been observed in cellular models of HD. However, the implication of the JNK pathway has not previously been evaluated in the striatum of HD animal models. Here we report that the JNK pathway participates in HD pathology in a rat model of the disease. Increased phosphorylation of the JNK target c-Jun was observed as early as 4 weeks and persisted for 13 weeks after lentiviral-mediated expression of htt171-82Q. In order to assess the importance of this pathway in HD pathology, JNK inhibitors including dominant-negative mutants of upstream kinases (ASK1(K709R), MEKK1(D1369A)), a c-Jun mutant (Delta169c-Jun) and the active domain of the scaffold protein JIP-1/IBI (IBI-JBD) were tested for their ability to mitigate the effect of htt171-82Q. The overexpression of MEKK1(D1369A) and JIP-1/IBI reduced the polyQ-related loss of DARPP-32 expression, while the other inhibitors had no effect. In all cases, the formation of EM48-positive htt inclusions and P-c-Jun immunoreactivity were unaltered. These results suggest that JNK activation is involved in HD and that blockade of this pathway may be of benefit in counteracting HD-related neurotoxicity.
Also flagged:adaptor proteinsorganellesaxonal-bassoon Transportmitochondriaaxons
Journal Article2008-10-27No SnippetsGoldstein AY, Wang X, Schwarz TL.
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The mechanisms for delivering components to nerve terminals are diverse and highly regulated. The diversity of kinesin motors alone is insufficient to account for the specificity of delivery. Additional specificity and control are contributed by adaptor proteins and associated regulatory molecules. The interaction of cargos with these complexes can confer distinct behaviors on the transport of synaptic organelles. The rich regulatory mechanisms of transport that are only now emerging as the cargo-motor complexes are defined and subsequent local events that regulate their dynamic relationship are examined. Here we review recent studies of kinesin-related axonal transport of three crucial synaptic components, Piccolo-bassoon Transport Vesicles (PTVs), Synaptic Vesicle Precursors (SVPs), and mitochondria, and the mechanisms that modulate their transport.
Also flagged:gene expressionHuntington's diseaseHD-onset neurodegenerative disorderneurodegenerative disordersspinal and bulbar muscular atrophy
Journal Article2008-10-27✓ 4 SnippetsBenn CL, Fox H, Bates GP.
In-Text Gene Mentions
Introduction)
…Huntington's disease (HD) is an autosomal dominant, late-onset neurodegenerative disorder caused by a CAG repeat expansion in exon 1 of the HD gene which translates into a polyglutamine (polyQ) tract in the huntingtin (Htt) protein [1].…
Introduction)
…in the huntingtin (Htt) protein [ 1…
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…but not mutantHttthrough interactions with…
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…function of mutantHttprotein, although the…
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<h4>Background</h4>Transcriptional dysregulation is an early, key pathogenic mechanism in Huntington's disease (HD). Therefore, gene expression analyses have biomarker potential for measuring therapeutic efficacy in pre-clinical trials, particularly those aimed at correcting gene expression abnormalities. Housekeeping genes are commonly used as endogenous references in gene expression studies. However, a systematic study comparing the suitability of candidate reference genes for use in HD mouse models has not been performed. To remedy this situation, 12 housekeeping genes were examined to identify suitable reference genes for use in expression assays.<h4>Results</h4>We found that commonly used reference genes are dysregulated at later time points in the R6/2 mouse model of HD. Therefore, in order to reliably measure gene expression changes for use as pre-clinical trial biomarkers, we set out to identify suitable reference genes for use in R6/2 mice. The expression of potential reference genes was examined in striatum, cortex and cerebellum from 15 week old R6/2 and matched wild-type littermates. Expression levels of candidate reference genes varied according to genotype and brain region. GeNorm software was used to identify the three most stably expressed genes for each brain region. Relative quantification methods using the geometric mean of three reference genes for normalisation enables accurate determination of gene expression levels in wild-type and R6/2 mouse brain regions.<h4>Conclusion</h4>Our study has identified a reproducible, reliable method by which we able to accurately determine the relative expression level of target genes in specific brain regions, thus increasing the potential of gene expression analysis as a biomarker in HD pre-clinical trials.
Also flagged:protein Sprotein Cdeep vein thrombosisPROS1PROCDVT
Journal Article2008-10-26✓ 5 SnippetsMiyata T, Sato Y, Ishikawa J, Okada H, Takeshita S, Sakata T, Kokame K, Kimura R, Honda S, Kawasaki T, Suehisa E, Tsuji H, Madoiwa S, Sakata Y, Kojima T, Murata M, Ikeda Y.
In-Text Gene Mentions
Abstract)
…Genetic deficiencies of PROS1, PROC, and SERPINC1 (antithrombin) are risk factors for deep vein thrombosis (DVT).…
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…<h4>Introduction</h4>Genetic deficiencies of PROS1, PROC, and SERPINC1 (antithrombin) are risk factors for deep vein thrombosis (DVT).…
Abstract)
…We sequenced the entire coding regions of the three genes in all DNA samples and identified the nonsynonymous mutations.<h4>Results and conclusions</h4>For PROS1 we identified 15 nonsynonymous mutations in 28 DVT patients; for PROC, 10 nonsynonymous mutations in 17 patients; and for SERPINC1, 13 nonsynonymous mutations in 14 patients.…
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…PROS1, PROC, andSERPINC1(antithrombin) are risk…
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…patients; and forSERPINC1, 13 nonsynonymous mutations…
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<h4>Introduction</h4>Genetic deficiencies of PROS1, PROC, and SERPINC1 (antithrombin) are risk factors for deep vein thrombosis (DVT). Diagnosis of the inherited deficiencies of these three genes is sometimes difficult because of the phenotypic variability. This study was undertaken to reveal the frequency of nonsynonymous mutations of these three genes in Japanese DVT patients.<h4>Patients/methods</h4>One hundred seventy-three DVT patients were registered by the Sub-group of Blood Coagulation Abnormality, from the Study Group of Research on Measures for Intractable Diseases. We sequenced the entire coding regions of the three genes in all DNA samples and identified the nonsynonymous mutations.<h4>Results and conclusions</h4>For PROS1 we identified 15 nonsynonymous mutations in 28 DVT patients; for PROC, 10 nonsynonymous mutations in 17 patients; and for SERPINC1, 13 nonsynonymous mutations in 14 patients. Five patients had two mutations in PROS1 and PROC, and all of them had PROS1 K196E mutation. We previously identified one patient with a large PROS1 gene deletion. Thus, 55 out of 173 patients (32%) carried at least one genetic defect in the three genes. The PROS1 K196E mutation found in 15 Japanese DVT patients was the most prevalent. Mutations of PROC K193del and V339M were the second, each found in four patients. Our data suggested that the PROC K193del mutation caused the loss of the anticoagulant activity but not the amidolytic activity. Our effort is the first DNA resequencing study to identify the genetic variations in DVT patients without any consideration of their plasma activities and antigens. To minimize selection bias in a future evaluation of the contribution of genetic deficiency to DVT, we must recruit patients consecutively.
Mitochondrial complex I inhibition has been implicated in the degeneration of midbrain dopaminergic (DA) neurons in Parkinson's disease. However, the mechanisms and pathways that determine the cellular fate of DA neurons downstream of the mitochondrial dysfunction have not been fully identified. We conducted cell-type specific gene array experiments with nigral DA neurons from rats treated with the complex I inhibitor, rotenone, at a dose that does not induce cell death. The genome wide screen identified transcriptional changes in multiple cell death related pathways that are indicative of a simultaneous activation of both degenerative and protective mechanisms. Quantitative PCR analyses of a subset of these genes in different neuronal populations of the basal ganglia revealed that some of the changes are specific for DA neurons, suggesting that these neurons are highly sensitive to rotenone. Our data provide insight into potentially defensive strategies of DA neurons against disease relevant insults.
Also flagged:Sterolphospholipidscholesterolphospholipidglycerophospholipidsmembrane
Journal Article2008-10-25No SnippetsHuang Z, Szoka FC.
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We synthesized a family of sterol-modified glycerophospholipids (SML) in which the sn-1 or sn-2 position is covalently attached to cholesterol and the alternative position contains an aliphatic chain. The SML were used to explore how anchoring cholesterol to a phospholipid affects cholesterol behavior in a bilayer. Notably, cholesterol in the SML retains the membrane condensing properties of free cholesterol regardless of the chemistry or position of its attachment to the glycerol moiety of the phospholipid. SMLs by themselves formed liposomes upon hydration and in mixtures between an SML and diacylglycerophospholipids (C14 to C18 chain length) the thermotropic phase transition is eliminated at the SML equivalent of about 30 mol % free cholesterol. Osmotic-induced contents leakage from SML (C14-C18) liposomes depends upon the linkage and position of cholesterol but in general is similar to that observed in 3/2 diacylphosphatidylcholine/cholesterol (mole ratio) liposomes. SML liposomes are exceptionally resistant to contents release in the presence of serum at 37 degrees C. This is probably due to the fact that SML exchange between bilayers is more than 100 fold less than the exchange rate of free cholesterol in the same conditions. Importantly, SML liposomes containing doxorubicin are as effective in treating the murine C26 colon carcinoma as Doxil, a commercial liposome doxorubicin formulation. SMLs stabilize bilayers but do not exchange and hence provide a new tool for biophysical studies on membranes. They may improve liposomal drug delivery in organs predisposed to the extraction of free cholesterol from bilayers, such as the skin, lung, or blood.
Also flagged:cancersodium butyrateHDCcolorectal canceradenomap53
Journal Article2008-10-24✓ 1 SnippetAleksic T, Feller SM.
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Discussion)
…], E-Cadherin andDCC[ 47 ].…
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<h4>Background</h4>Notch signalling is essential for the development and maintenance of the colonic epithelium. Its inhibition induces a differentiation phenotype in vivo and reduces adenomas in APCmin mice. Whether Notch signals are also required in colorectal cancer (CRC) has remained elusive. Therefore, 64 CRC cell lines were analysed for the occurrence of proteolytically processed, active Notch.<h4>Results</h4>63 CRC lines contained a fragment with approximately the size of the Notch1 intracellular domain (NICD), which is required for signalling. Subsequent analyses with an antibody that specifically recognises the free Val1744 residue generated by gamma-secretase-mediated cleavage of Notch1 showed that a subset of CRC cells lacks this specific Val1744-NICD. Surprisingly, inhibition of Val1744-NICD signalling with different gamma-secretase inhibitors (GSI) did not lead to substantial effects on CRC cell line growth or survival. However, transient activation of Erk upon GSI treatment was detected. Since cisplatin relies on Erk activation for bioactivity in some cells, platinum compounds were tested together with GSI and enhanced cell killing in a subset of Val1744-NICD-positive CRC cell lines was detected. Erk inhibition ablated this combination effect.<h4>Conclusion</h4>We conclude that gamma-secretase inhibition results in activation of the MAP kinases Erk1/2 and, when used in conjunction, enhances cell death induced by platinum compounds in a large subset of colorectal cancer cell lines.Furthermore the activation of Erk appears to be of particular importance in mediating the enhanced effect seen, as its inhibition abrogates the observed phenomenon. These findings do not only highlight the importance of signalling pathway crosstalk but they may also suggest a new avenue of combination therapy for some colorectal cancers.
Also flagged:Huntington's diseasemitochondrialorganelleHDdeathneurodegenerative disorder
Journal Article2008-10-24✓ 1 SnippetBossy-Wetzel E, Petrilli A, Knott AB.
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…Htt…
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Huntington's disease (HD) is a fatal, inherited neurodegenerative disorder that gradually robs affected individuals of memory, cognitive skills and normal movements. Although research has identified a single faulty gene, the huntingtin gene, as the cause of the disease, a cure remains elusive. Strong evidence indicates that mitochondrial impairment plays a key part in HD pathogenesis. Here, we highlight how mutant huntingtin (mtHtt) might cause mitochondrial dysfunction by either perturbing transcription of nuclear-encoded mitochondrial proteins or by direct interaction with the organelle and modulation of respiration, mitochondrial membrane potential and Ca(2+) buffering. In addition, we propose that mtHtt might convey its neurotoxicity by evoking defects in mitochondrial dynamics, organelle trafficking and fission and fusion, which, in turn, might result in bioenergetic failure and HD-linked neuronal dysfunction and cell death. Finally, we speculate how mitochondria might dictate selective vulnerability of long projection neurons, such as medium spiny neurons, which are particularly affected in HD.
A network of connections is established as neural circuits form between neurons. To make these connections, neurons initiate asymmetric axon outgrowth in response to extracellular guidance cues. Within the specialized growth cones of migrating axons, F-actin and microtubules asymmetrically accumulate where an axon projects forward. Although many guidance cues, receptors and intracellular signaling components that are required for axon guidance have been identified, the means by which the asymmetry is established and maintained is unclear. Here, we discuss recent studies in invertebrate and vertebrate organisms that define a signaling module comprising UNC-6 (the Caenorhabditis elegans ortholog of netrin), UNC-40 (the C. elegans ortholog of DCC), PI3K, Rac and MIG-10 (the C. elegans ortholog of lamellipodin) and we consider how this module could establish polarized outgrowth in response to guidance cues.
Also flagged:dibenzofurancarbondegradationdioxinsamino acidbinding
Journal Article2008-10-24No SnippetsIida T, Waki T, Nakamura K, Mukouzaka Y, Kudo T.
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Dibenzofuran (DF) is one of the dioxin carbon skeletal compounds used as a model to study the microbial degradation of dioxins. This study analyzed the transcriptional regulation of the DF dioxygenase genes dfdA1 to dfdA4 in the DF-utilizing actinomycetes Rhodococcus sp. strain YK2 and Terrabacter sp. strain YK3. An open reading frame designated dfdR was detected downstream of the dfdC genes. The C-terminal part of the DfdR amino acid sequence has high levels of similarity to several LuxR-type DNA binding helix-turn-helix domains, and a GAF domain sequence in the central part was detected by a domain search analysis. A derivative of YK2 with dfdR disrupted was not able to utilize DF and did not exhibit DF-dependent dfdA1 transcriptional induction ability, and these dysfunctions were compensated for by introduction of dfdR. Promoter analysis of dfdA1 in Rhodococcus strains indicated that activation of the dfdA1 promoter (P(dfdA1)) was dependent on dfdR and DF and not on a metabolite of the DF pathway. The cell extract of a Rhodococcus strain that heterologously expressed DfdR showed electrophoretic mobility shift (EMS) activity for the P(dfdA1) DNA fragment in a DF-dependent manner. In addition, P(dfdA1) activation and EMS activity were observed with hydrophobic aromatic compounds comprising two or more aromatic rings, suggesting that DfdR has broad effector molecule specificity for several hydrophobic aromatic compounds.
…oasaminoglycans modulating theATIIIactivity in vivo…
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On March 19, 2008 a Symposium on Pathophysiology of Ageing and Age-Related Diseases was held in Palermo, Italy. The lecture of D. Mari on Hemostasis and ageing is summarized herein. Physiological ageing is associated with increased plasma levels of many proteins of blood coagulation together with fibrinolysis impairment. This may be of great concern in view of the known association between vascular and thromboembolic diseases and ageing. On the other hand, centenarians are characterized by a state of hypercoagulability and possession of several high-risk alleles and well-known atherothrombotic risk markers but this appears to be compatible with longevity and/or health. Parameters considered risk factors for atherosclerotic vascular diseases in young people may lose their biological significance in advanced age and assume a different role.
Also flagged:cell surfacegene expressiontranscription factorssignal transductionfibroblast growth factorsFGFs
Journal Article2008-10-23No SnippetsCampanelli JT, Sandrock RW, Wheatley W, Xue H, Zheng J, Liang F, Chesnut JD, Zhan M, Rao MS, Liu Y.
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<h4>Background</h4>We have generated gene expression databases for human glial precursors, neuronal precursors, astrocyte precursors and neural stem cells and focused on comparing the profile of glial precursors with that of other populations.<h4>Results</h4>A total of 14 samples were analyzed. Each population, previously distinguished from each other by immunocytochemical analysis of cell surface markers, expressed genes related to their key differentiation pathways. For the glial precursor cell population, we identified 458 genes that were uniquely expressed. Expression of a subset of these individual genes was validated by RT-PCR. We also report genes encoding cell surface markers that may be useful for identification and purification of human glial precursor populations.<h4>Conclusion</h4>We provide gene expression profile for human glial precursors. Our data suggest several signaling pathways that are important for proliferation and differentiation of human glial precursors. Such information may be utilized to further purify glial precursor populations, optimize media formulation, or study the effects of glial differentiation.
…Our results support the model that Dscam proteins function as attractive receptors for Netrin and also act in parallel to Frazzled/DCC.…
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…Fra)/DCC…
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…part by Frazzled (Fra)/DCC receptorsreceptors.…
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…same affinity asDCC.…
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…in parallel to Frazzled/DCC.…
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Developing axons are attracted to the CNS midline by Netrin proteins and other as yet unidentified signals. Netrin signals are transduced in part by Frazzled (Fra)/DCC receptors. Genetic analysis in Drosophila indicates that additional unidentified receptors are needed to mediate the attractive response to Netrin. Analysis of Bolwig's nerve reveals that Netrin mutants have a similar phenotype to Down Syndrome Cell Adhesion Molecule (Dscam) mutants. Netrin and Dscam mutants display dose sensitive interactions, suggesting that Dscam could act as a Netrin receptor. We show using cell overlay assays that Netrin binds to fly and vertebrate Dscam, and that Dscam binds Netrin with the same affinity as DCC. At the CNS midline, we find that Dscam and its paralog Dscam3 act redundantly to promote midline crossing. Simultaneous genetic knockout of the two Dscam genes and the Netrin receptor fra produces a midline crossing defect that is stronger than the removal of Netrin proteins, suggesting that Dscam proteins also function in a pathway parallel to Netrins. Additionally, overexpression of Dscam in axons that do not normally cross the midline is able to induce ectopic midline crossing, consistent with an attractive receptor function. Our results support the model that Dscam proteins function as attractive receptors for Netrin and also act in parallel to Frazzled/DCC. Furthermore, the results suggest that Dscam proteins have the ability to respond to multiple ligands and act as receptors for an unidentified midline attractive cue. These functions in axon guidance have implications for the pathogenesis of Down Syndrome.
Also flagged:ironcanceroxygenendometriosisiron transporterspeptide hormone
Journal Article2008-10-23✓ 2 SnippetsToyokuni S.
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Abstract)
…conditions such ashemochromatosis, chronic viral hepatitis…
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…hemochromatosis…
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Iron is abundant universally. During the evolutionary processes, humans have selected iron as a carrier of oxygen inside the body. However, iron works as a double-edged sword, and its excess is a risk for cancer, presumably via generation of reactive oxygen species. Thus far, pathological conditions such as hemochromatosis, chronic viral hepatitis B and C, exposure to asbestos fibers, as well as endometriosis have been recognized as iron overload-associated risks for human cancer. Indeed, iron is carcinogenic in animal experiments. These reports unexpectedly revealed that there are target genes in iron-induced carcinogenesis and that iron-catalyzed oxidative DNA damage is not random in vivo. Several iron transporters and hepcidin, a peptide hormone regulating iron metabolism, were discovered in the past decade. Furthermore, a recent epidemiological study reported that iron reduction by phlebotomy decreased cancer risk in the apparently normal population. These results warrant reconsideration of the role of iron in carcinogenesis and suggest that fine control of body iron stores would be a wise strategy for cancer prevention.
CPT-11 is a clinically used cancer drug, and it is a prodrug of the potent topoisomerase I inhibitor, SN-38 (7-ethyl-10-hydroxycamptothecin). To bypass the need for the in vivo conversion of CPT-11 and increase the therapeutic index, bifunctional derivatives of SN-38 were prepared for use in antibody-based targeted therapy of cancer. The general synthetic scheme incorporated an acetylene-azide click cycloaddition step in the design, a short polyethylene glycol spacer for aqueous solubility, and a maleimide group for conjugation. Conjugates of a humanized anti-CEACAM5 monoclonal antibody, hMN-14, prepared using these SN-38 derivatives were evaluated in vitro for stability in buffer and human serum and for antigen-binding and cytotoxicity in a human colon adenocarcinoma cell line. Conjugates of hMN-14 and SN-38 derivatives 16 and 17 were found promising for further development.
Also flagged:adult-onset autosomal dominant leukodystrophyADLDAutosomal Dominant Leukodystrophymicturitionpostural hypotensionataxia
Journal Article2008-10-22✓ 1 SnippetSundblom J, Melberg A, Kalimo H, Smits A, Raininko R.
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…DARS2…
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<h4>Background and purpose</h4>MR imaging findings in adult-onset autosomal dominant leukodystrophy (ADLD) with autonomic symptoms have been described in the brain, but no descriptions of MR imaging findings in the spinal cord have been published. Here, we describe MR imaging findings in the spinal cord in adult-onset ADLD with autonomic symptoms and histopathologic investigations of the spinal cord.<h4>Materials and methods</h4>Twelve subjects from 2 families with adult-onset ADLD with autonomic symptoms identified by clinical investigation underwent MR imaging examination of the spinal cord. Sagittal and transverse sections were obtained. MR imaging examination of the brain was performed in 11 patients. One of the patients underwent postmortem examination, and the spinal cord was subjected to histopathologic analysis.<h4>Results</h4>In all family members with adult-onset ADLD with autonomic symptoms, even in the asymptomatic person, the spinal cord was thin. All examined family members also had a slight general white matter signal intensity (SI) increase in the whole spinal cord, mainly visible in T2-weighted transverse images. The pathologic examination revealed a discrete demyelination in the spinal cord. Brain MR imaging also showed increased T2 SI in the white matter.<h4>Conclusions</h4>The spinal cord is affected in adult-onset ADLD with autonomic symptoms. Findings consist of atrophy and a diffuse T2 SI increase in the white matter. Transverse images are needed to assess these findings. The typical SI changes of the spinal cord are also present in subjects without clinical symptoms of the disease and with very limited changes in the brain.
…Here, we focus on the role of the BRN2 (POU3F2/N-Oct-3) transcription factor in the melanocytic lineage where it may co-ordinate normal developmental cues that can be re-activated in melanoma.…
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…of the BRN2 (POU3F2/N-Oct-3) transcription factor…
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Several parallels between stem cell biology and tumour behaviour have been discovered in recent times. Such commonality is apparent in the unlimited capacity for cell division together with the lack of a differentiated phenotype in embryonic and adult stem cells, traits shared with tumour cells. Differentiation is a tightly regulated process that is mediated by the actions of multiple transcription factor families. The POU domain-containing family of transcription factors contains multiple mammalian members divided into six classes, which can be expressed broadly or in a cell-specific manner, and which are regulators of cell fate decisions of many different lineages. Target gene regulation can occur via a POU factor acting alone, or in combination with other POU proteins, ubiquitous co-activators or co-repressors, or other lineage restricted transcription factors. Aberrant levels of POU proteins have been found in several malignancies, including melanoma, connecting the otherwise developmentally restricted gene regulatory functions of POU transcription factors to the critical determinants of malignant transformation. Here, we focus on the role of the BRN2 (POU3F2/N-Oct-3) transcription factor in the melanocytic lineage where it may co-ordinate normal developmental cues that can be re-activated in melanoma. Recent studies have shown BRN2 to be responsive to MAPK pathway activation and to modulate the levels of MITF so as to suppress the differentiated melanocytic phenotype and to enhance tumour metastasis.
Also flagged:neurodegenerative disordersAlzheimer's diseaseADHuntington's diseaseHDNMDA receptors
Journal Article2008-10-21✓ 1 SnippetWu J, Li Q, Bezprozvanny I.
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Introduction)
…The mutant huntingtin (Htt) with expanded polyglutamine…
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<h4>Background</h4>Dimebon is an antihistamine compound with a long history of clinical use in Russia. Recently, Dimebon has been proposed to be useful for treating neurodegenerative disorders. It has demonstrated efficacy in phase II Alzheimer's disease (AD) and Huntington's disease (HD) clinical trials. The mechanisms responsible for the beneficial actions of Dimebon in AD and HD remain unclear. It has been suggested that Dimebon may act by blocking NMDA receptors or voltage-gated Ca2+ channels and by preventing mitochondrial permeability pore transition.<h4>Results</h4>We evaluated the effects of Dimebon in experiments with primary striatal neuronal cultures (MSN) from wild type (WT) mice and YAC128 HD transgenic mice. We found that Dimebon acts as an inhibitor of NMDA receptors (IC50 = 10 muM) and voltage-gated calcium channels (IC50 = 50 muM) in WT and YAC128 MSN. We further found that application of 50 muM Dimebon stabilized glutamate-induced Ca2+ signals in YAC128 MSN and protected cultured YAC128 MSN from glutamate-induced apoptosis. Lower concentrations of Dimebon (5 muM and 10 muM) did not stabilize glutamate-induced Ca2+ signals and did not exert neuroprotective effects in experiments with YAC128 MSN. Evaluation of Dimebon against a set of biochemical targets indicated that Dimebon inhibits alpha-Adrenergic receptors (alpha1A, alpha1B, alpha1D, and alpha2A), Histamine H1 and H2 receptors and Serotonin 5-HT2c, 5-HT5A, 5-HT6 receptors with high affinity. Dimebon also had significant effect on a number of additional receptors.<h4>Conclusion</h4>Our results suggest that Ca2+ and mitochondria stabilizing effects may, in part, be responsible for beneficial clinical effects of Dimebon. However, the high concentrations of Dimebon required to achieve Ca2+ stabilizing and neuroprotective effects in our in vitro studies (50 muM) indicate that properties of Dimebon as cognitive enhancer are most likely due to potent inhibition of H1 histamine receptors. It is also possible that Dimebon acts on novel high affinity targets not present in cultured MSN preparation. Unbiased evaluation of Dimebon against a set of biochemical targets indicated that Dimebon efficiently inhibited a number of additional receptors. Potential interactions with these receptors need to be considered in interpretation of results obtained with Dimebon in clinical trials.
Also flagged:Haemochromatosisend-stage renal diseasehereditary haemochromatosisanaemiaironrenal anaemia
Journal Article2008-10-21✓ 2 SnippetsOettl T, Dickenmann M.
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Discussion)
…type of HH (non-HFE haemochromatosishaemochromatosis), which affec…
I A O 0000613)
…the most commonHFEmutations (C282Y, H63D,…
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For patients with end-stage renal disease and hereditary haemochromatosis, prevention and treatment of anaemia differ from usual nephrologic guidelines. Monitoring of individual disease progression and ferritin levels is crucial. We describe a case of a young haemodialysis patient with early-stage organ dysfunction caused by hereditary haemochromatosis, in whom iron stores have successfully been depleted with phlebotomy and supplemental erythropoietin over 22 months. Target ferritin levels could finally be reached without severe, persisting or symptomatic anaemia.
Also flagged:Sam68Src-associated in mitosis, 68 kDaKH domain RNA binding proteinbindingSgceneurogenesis
Journal Article2008-10-20✓ 1 SnippetChawla G, Lin CH, Han A, Shiue L, Ares M, Black DL.
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…Sox6…
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Sam68 (Src-associated in mitosis, 68 kDa) is a KH domain RNA binding protein implicated in a variety of cellular processes, including alternative pre-mRNA splicing, but its functions are not well understood. Using RNA interference knockdown of Sam68 expression and splicing-sensitive microarrays, we identified a set of alternative exons whose splicing depends on Sam68. Detailed analysis of one newly identified target exon in epsilon sarcoglycan (Sgce) showed that both RNA elements distributed across the adjacent introns and the RNA binding activity of Sam68 are necessary to repress the Sgce exon. Sam68 protein is upregulated upon neuronal differentiation of P19 cells, and many Sam68 RNA targets change in expression and splicing during this process. When Sam68 is knocked down by short hairpin RNAs, many Sam68-dependent splicing changes do not occur and P19 cells fail to differentiate. We also found that the differentiation of primary neuronal progenitor cells from embryonic mouse neocortex is suppressed by Sam68 depletion and promoted by Sam68 overexpression. Thus, Sam68 controls neurogenesis through its effects on a specific set of RNA targets.
<h4>Background</h4>Vocal learning is a rare and complex behavioral trait that serves as a basis for the acquisition of human spoken language. In songbirds, vocal learning and production depend on a set of specialized brain nuclei known as the song system.<h4>Methodology/principal findings</h4>Using high-throughput functional genomics we have identified approximately 200 novel molecular markers of adult zebra finch HVC, a key node of the song system. These markers clearly differentiate HVC from the general pallial region to which HVC belongs, and thus represent molecular specializations of this song nucleus. Bioinformatics analysis reveals that several major neuronal cell functions and specific biochemical pathways are the targets of transcriptional regulation in HVC, including: 1) cell-cell and cell-substrate interactions (e.g., cadherin/catenin-mediated adherens junctions, collagen-mediated focal adhesions, and semaphorin-neuropilin/plexin axon guidance pathways); 2) cell excitability (e.g., potassium channel subfamilies, cholinergic and serotonergic receptors, neuropeptides and neuropeptide receptors); 3) signal transduction (e.g., calcium regulatory proteins, regulators of G-protein-related signaling); 4) cell proliferation/death, migration and differentiation (e.g., TGF-beta/BMP and p53 pathways); and 5) regulation of gene expression (candidate retinoid and steroid targets, modulators of chromatin/nucleolar organization). The overall direction of regulation suggest that processes related to cell stability are enhanced, whereas proliferation, growth and plasticity are largely suppressed in adult HVC, consistent with the observation that song in this songbird species is mostly stable in adulthood.<h4>Conclusions/significance</h4>Our study represents one of the most comprehensive molecular genetic characterizations of a brain nucleus involved in a complex learned behavior in a vertebrate. The data indicate numerous targets for pharmacological and genetic manipulations of the song system, and provide novel insights into mechanisms that might play a role in the regulation of song behavior and/or vocal learning.
Also flagged:iodideetherCalixareneethyl acetateS21calix[4]arenes
Journal Article2008-10-20No SnippetsOsipov M, Chu Q, Geib SJ, Curran DP, Weber SG.
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Several lower-rim perfluoroalkylated (fluorous) calix[4]arenes have been synthesized by O-alkylation of the parent calix[4]arene. The compounds are formed in the cone conformation. They are soluble in several fluorous solvents and show promise for use in sensing, selective extractions and other applications.
Journal Article2008-10-19✓ 2 SnippetsLiu W, Kennington LA, Rosas HD, Hersch S, Cha JH, Zamore PD, Aronin N.
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Abstract)
…two huntingtin (HTT) alleles—normal and…
I A O 0000326)
…HTT…
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Allele-specific silencing using small interfering RNAs targeting heterozygous single-nucleotide polymorphisms (SNPs) is a promising therapy for human trinucleotide repeat diseases such as Huntington's disease. Linking SNP identities to the two HTT alleles, normal and disease-causing, is a prerequisite for allele-specific RNA interference. Here we describe a method, SNP linkage by circularization (SLiC), to identify linkage between CAG repeat length and nucleotide identity of heterozygous SNPs using Huntington's disease patient peripheral blood samples.
Also flagged:DeferasiroxciprofloxacinVibrio vulnificus sepsispolymeraseVibrio vulnificussepsis
Journal Article2008-10-18✓ 1 SnippetKim DM, Cho HS, Kang JI, Kim HS, Park CY.
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…due to secondaryhemochromatosisof myelodysplastic syndrome.…
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We report a case of Vibrio vulnificus sepsis developed during deferoxamine therapy for transfusional iron overload due to secondary hemochromatosis of myelodysplastic syndrome. The patient was treated with adjuvant deferasirox in combination with ciprofloxacin, after rapid diagnosis of V. vulnificus sepsis using real-time polymerase chain reaction (PCR). This case suggests that since V. vulnificus DNA can be detected by real-time PCR for several days even after patients receive antibiotics, real-time PCR for V. vulnificus is a very useful test for establishing an early diagnosis, even if a patient has been treated with antibiotics prior to admission.
Also flagged:PhosphorylationHuntingtinserineprotein kinasesAktSGK
Journal Article2008-10-18✓ 1 SnippetWarby SC, Doty CN, Graham RK, Shively J, Singaraja RR, Hayden MR.
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Abstract)
…Nuclear localization of huntingtin is also an important marker of HD and preventing or delaying its nuclear accumulation is protective in disease models.…
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Huntingtin is phosphorylated on serine-421 (S421) by the pro-survival signaling protein kinases Akt and SGK. Phosphorylation of huntingtin at S421 is variable in different regions of the brain with the lowest levels observed in the striatum, which is further reduced by the mutation for Huntington disease (HD). Cleavage of huntingtin by caspase-6 at amino acid 586 is a crucial event in the pathogenesis of HD. Nuclear localization of huntingtin is also an important marker of HD and preventing or delaying its nuclear accumulation is protective in disease models. Phosphorylation influences proteolysis and clearance of many protein substrates. We therefore sought to investigate the influence of huntingtin phosphorylation at S421 on the accumulation of huntingtin-caspase-6 fragments because these fragments are generated in the nucleus and are crucial for the disease phenotype. Using phospho-huntingtin mutants and a cleavage site-specific neo-epitope huntingtin antibody, we demonstrate that phosphorylation at S421 reduces the nuclear accumulation of huntingtin-caspase-6 fragments by reducing huntingtin cleavage by caspase-6, the levels of full-length huntingtin, and its nuclear localization.
Also flagged:Serotonin transporteranxietystartle reflex5
Journal Article2008-10-17✓ 3 SnippetsArmbruster D, Moser DA, Strobel A, Hensch T, Kirschbaum C, Lesch KP, Brocke B.
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Abstract)
…Genetic variation of the serotonin transporter (5-HTT) has been associated with fear- and anxiety-related behaviours.…
Abstract)
…the serotonin transporter (5-HTT) has been associated…
Abstract)
…allele of the5-HTTgene in imaging…
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Genetic variation of the serotonin transporter (5-HTT) has been associated with fear- and anxiety-related behaviours. The amygdala is considered crucial in emotional modulation and stronger amygdala reactivity in response to fearful stimuli has been found in carriers of the short (S) allele of the 5-HTT gene in imaging studies. Additionally, reactivity of amygdala-innervated effectory systems is also of particular interest. We recently reported the impact of a functional polymorphism in the transcriptional control region of the serotonin transporter gene (5-HTTLPR) on the acoustic startle reflex. Here, we attempted to replicate and extend these findings. Startle magnitudes to intense noise bursts as measured with the eyeblink response were recorded in 106 healthy volunteers during baseline without additional stimulation and while they viewed pictures of three valence conditions: unpleasant, pleasant and neutral. Subjects were genotyped for the tri-allelic functional polymorphism 5-HTTLPR. In replication of our previous findings we found that carriers of the low-expressing S or LG alleles exhibited stronger overall startle responses across conditions than LA/LA homozygotes, while there were no differences in emotional startle modulation between the two genetic groups. In addition, we found that the recent experience of stressful life events resulted in overall higher startle responses and less startle habituation across blocks. The results replicate and emphasize the role of 5-HTTLPR and stress on the overall startle response as a possible genetically driven endophenotype for anxiety-related behaviour.
Also flagged:Condensin IIanaphase IchromosomeprophasemaleCap-H2
Journal Article2008-10-17✓ 2 SnippetsHartl TA, Sweeney SJ, Knepler PJ, Bosco G.
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Introduction)
…Condensincomplexes may also…
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…Condensinhas been shown…
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Several meiotic processes ensure faithful chromosome segregation to create haploid gametes. Errors to any one of these processes can lead to zygotic aneuploidy with the potential for developmental abnormalities. During prophase I of Drosophila male meiosis, each bivalent condenses and becomes sequestered into discrete chromosome territories. Here, we demonstrate that two predicted condensin II subunits, Cap-H2 and Cap-D3, are required to promote territory formation. In mutants of either subunit, territory formation fails and chromatin is dispersed throughout the nucleus. Anaphase I is also abnormal in Cap-H2 mutants as chromatin bridges are found between segregating heterologous and homologous chromosomes. Aneuploid sperm may be generated from these defects as they occur at an elevated frequency and are genotypically consistent with anaphase I segregation defects. We propose that condensin II-mediated prophase I territory formation prevents and/or resolves heterologous chromosomal associations to alleviate their potential interference in anaphase I segregation. Furthermore, condensin II-catalyzed prophase I chromosome condensation may be necessary to resolve associations between paired homologous chromosomes of each bivalent. These persistent chromosome associations likely consist of DNA entanglements, but may be more specific as anaphase I bridging was rescued by mutations in the homolog conjunction factor teflon. We propose that the consequence of condensin II mutations is a failure to resolve heterologous and homologous associations mediated by entangled DNA and/or homolog conjunction factors. Furthermore, persistence of homologous and heterologous interchromosomal associations lead to anaphase I chromatin bridging and the generation of aneuploid gametes.
Also flagged:DCISpreinvasive tumorsinvasivegene expressioninvasive ductal carcinomaDNase
Journal Article2008-10-17No SnippetsCastro NP, Osório CA, Torres C, Bastos EP, Mourão-Neto M, Soares FA, Soares FA, Brentani HP, Carraro DM.
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<h4>Introduction</h4>Ductal carcinoma in situ (DCIS) of the breast includes a heterogeneous group of preinvasive tumors with uncertain evolution. Definition of the molecular factors necessary for progression to invasive disease is crucial to determining which lesions are likely to become invasive. To obtain insight into the molecular basis of DCIS, we compared the gene expression pattern of cells from the following samples: non-neoplastic, pure DCIS, in situ component of lesions with co-existing invasive ductal carcinoma, and invasive ductal carcinoma.<h4>Methods</h4>Forty-one samples were evaluated: four non-neoplastic, five pure DCIS, 22 in situ component of lesions with co-existing invasive ductal carcinoma, and 10 invasive ductal carcinoma. Pure cell populations were isolated using laser microdissection. Total RNA was purified, DNase treated, and amplified using the T7-based method. Microarray analysis was conducted using a customized cDNA platform. The concept of molecular divergence was applied to classify the sample groups using analysis of variance followed by Tukey's test.<h4>Results</h4>Among the tumor sample groups, cells from pure DCIS exhibited the most divergent molecular profile, consequently identifying cells from in situ component of lesions with co-existing invasive ductal carcinoma as very similar to cells from invasive lesions. Additionally, we identified 147 genes that were differentially expressed between pure DCIS and in situ component of lesions with co-existing invasive ductal carcinoma, which can discriminate samples representative of in situ component of lesions with co-existing invasive ductal carcinoma from 60% of pure DCIS samples. A gene subset was evaluated using quantitative RT-PCR, which confirmed differential expression for 62.5% and 60.0% of them using initial and partial independent sample groups, respectively. Among these genes, LOX and SULF-1 exhibited features that identify them as potential participants in the malignant process of DCIS.<h4>Conclusions</h4>We identified new genes that are potentially involved in the malignant transformation of DCIS, and our findings strongly suggest that cells from the in situ component of lesions with co-existing invasive ductal carcinoma exhibit molecular alterations that enable them to invade the surrounding tissue before morphological changes in the lesion become apparent.
…the patient's underlyinghemochromatosismay have contributed…
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Hepatocellular carcinoma is rare, but increasing in prevalence in the United States. Recent studies have shown that sorafenib, a multikinase inhibitor, can reduce tumor progression in patients with this cancer. However, complete remission has not been observed. We report a case of a 78-year old patient with unresectable metastatic hepatocellular carcinoma who had a rapid and complete clinical response following therapy with sorafenib for six months. No evidence of disease recurrence has been noted for 6 months after discontinuation of therapy.
Also flagged:infectionsbiofilm infectionsdesferrioxaminegalliumironmetabolism
Journal Article2008-10-17✓ 1 SnippetBanin E, Lozinski A, Brady KM, Berenshtein E, Butterfield PW, Moshe M, Chevion M, Greenberg EP, Banin E.
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…hemochromatosis…
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The opportunistic pathogen Pseudomonas aeruginosa causes infections that are difficult to treat by antibiotic therapy. This bacterium can cause biofilm infections where it shows tolerance to antibiotics. Here we report the novel use of a metallo-complex, desferrioxamine-gallium (DFO-Ga) that targets P. aeruginosa iron metabolism. This complex kills free-living bacteria and blocks biofilm formation. A combination of DFO-Ga and the anti-Pseudomonas antibiotic gentamicin caused massive killing of P. aeruginosa cells in mature biofilms. In a P. aeruginosa rabbit corneal infection, topical administration of DFO-Ga together with gentamicin decreased both infiltrate and final scar size by about 50% compared to topical application of gentamicin alone. The use of DFO-Ga as a Trojan horse delivery system that interferes with iron metabolism shows promise as a treatment for P. aeruginosa infections.
Also flagged:Srcquercetintyrosine kinasehydrogenSrc tyrosine kinaseamino acid
Journal Article2008-10-17✓ 2 SnippetsHuang H, Jia Q, Ma J, Qin G, Chen Y, Xi Y, Lin L, Zhu W, Ding J, Jiang H, Liu H.
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Methods)
…of DCC (N,N-dicyclohexylcarbodiimide) as condensing agent and a little DMAP (4-dimethylaminopyridine) as catalyst.…
Methods)
…A mixture of compound 1 (100 mg, 0.175 mmol), DCC (43.2 mg, 0.209 mmol), DMAP (3 mg, 0.025 mmol) and Boc–Leu–OH·H2O (52.4 mg, 0.210 mmol) in THF (15 mL) was stirred at ambient temperature for 10 h. HRMS (ESI): Calcd.…
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Quercetin-3-O-amino acid-esters, a new type of quercetin derivatives, were successfully prepared for the first time. Different from quercetin, the novel compounds show higher selectivity as inhibitors against Src tyrosine kinase (IC(50) values ranging from 3.2 microM to 9.9 microM) than against EGFR tyrosine kinase. Molecular docking reveals that both hydrophobic and hydrogen bonding interactions are important to the selectivity. Therefore, this study provides a new promising scaffold for further development of new anticancer drugs targeting Src tyrosine kinase.
Also flagged:gene expressionPurkinje cell degenerationataxiadeathBadCDK5
Journal Article2008-10-16No SnippetsFord GD, Ford BD, Steele EC, Gates A, Hood D, Matthews MAB, Mirza S, MacLeish PR.
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The Purkinje cell degeneration (PCD) mutant mouse is characterized by a degeneration of cerebellar Purkinje cells and progressive ataxia. To identify the molecular mechanisms that lead to the death of Purkinje neurons in PCD mice, we used Affymetrix microarray technology to compare cerebellar gene expression profiles in pcd3J mutant mice 14 days of age (prior to Purkinje cell loss) to unaffected littermates. Microarray analysis, Ingenuity Pathway Analysis (IPA) and expression analysis systematic explorer (EASE) software were used to identify biological and molecular pathways implicated in the progression of Purkinje cell degeneration. IPA analysis indicated that mutant pcd3J mice showed dysregulation of specific processes that may lead to Purkinje cell death, including several molecules known to control neuronal apoptosis such as Bad, CDK5 and PTEN. These findings demonstrate the usefulness of these powerful microarray analysis tools and have important implications for understanding the mechanisms of selective neuronal death and for developing therapeutic strategies to treat neurodegenerative disorders.
Also flagged:liver cancerhepatocellular carcinomacancerinfectionHCV infectionChronic infection
Journal Article2008-10-16✓ 1 SnippetHassan MM, Spitz MR, Thomas MB, Curley SA, Patt YZ, Vauthey JN, Glover KY, Kaseb A, Lozano RD, El-Deeb AS, Nguyen NT, Wei SH, Chan W, Abbruzzese JL, Li D.
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…hemochromatosis…
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<h4>Background/aims</h4>The study aimed at addressing the connection between positive family history of liver cancer and hepatocellular carcinoma (HCC) development in the USA.<h4>Methods</h4>At The University of Texas M.D. Anderson Cancer Center, 347 patients with pathologically confirmed HCC and 1075 healthy controls were studied. All subjects were interviewed for their family history of cancer, including the number of relatives with cancer, the type of cancer, the individual's relationship with the relative, and the age at which the relative was diagnosed.<h4>Results</h4>Independently of hepatitis B virus (HBV) and hepatitis C virus (HCV), a history of liver cancer in first degree relatives was significantly associated with HCC development (AOR=4.1 [95% CI, 1.3-12.9]). Multiple relatives with liver cancer were only observed among HCC patients with chronic HBV/HCV infection. Affected siblings with liver cancer is significantly associated with HCC development with and without HBV/HCV infection; (AOR=5.7 [95% CI, 1.2-27.3]) and (AOR=4.3 [95% CI, 1.01-20.9]), respectively. Individuals with HBV/HCV and a family history of liver cancer were at higher risk for HCC (AOR=61.9 [95% CI, 6.6-579.7]).<h4>Conclusions</h4>First degree family history of liver cancer is associated with HCC development in the USA. Further research exploring the genetic-environment interactions associated with risk of HCC is warranted.
Also flagged:PtenTrp53prostate carcinomaTP53prostate cancertumor
Journal Article2008-10-16✓ 1 SnippetCouto SS, Cao M, Duarte PC, Banach-Petrosky W, Wang S, Romanienko P, Wu H, Cardiff RD, Abate-Shen C, Cunha GR.
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Abstract)
…Tumor suppressor gene PTENsuppressor gene PTEN…
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Tumor suppressor gene PTEN is important in the initiation and progression of human prostate carcinoma, whereas the role of TP53 remains controversial. Since Pten/Trp53 double conditional knockout mice show earlier onset and fast progression of prostate cancer when compared to Pten knockout mice, we asked whether heterozygosity of these two tumor suppressor genes was sufficient to accelerate prostatic tumorigenesis. To answer this question we examined prostatic lesion progression of Pten/Trp53 double heterozygous mice and a series of controls such as Pten heterozygous, Pten conditional knockout, Trp53 heterozygous and Trp53 knockout mice. Tissue recombination of adult prostatic epithelium coupled with embryonic rat seminal vesicle mesenchyme was used as a tool to stimulate prostatic epithelial proliferation. In our study, high-grade prostatic intraepithelial neoplasia (PIN) was found with high frequency at 8 weeks post-tissue recombination transplantation. PIN lesions in Pten/Trp53 double heterozygous mice were more severe than those seen in Pten heterozygous alone. Furthermore, morphologic features attributable to Pten or Trp53 loss appeared to be enhanced in double heterozygous tissues. LOH analysis of Pten and Trp53 in genomic DNA collected from high-grade PIN lesions in Pten heterozygous and Pten/Trp53 double heterozygous mice showed an intact wild-type allele for both genes in all samples examined. In conclusion, simultaneous heterozygosity of Pten and Trp53 accelerates prostatic tumorigenesis in this mouse model of prostate cancer independently of loss of heterozygosity of either gene.
…PAIRBP1/CGI-55, neogenin andDCC(deleted in colon…
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<h4>Introduction</h4>Breast tumors lacking the estrogen receptor-alpha (ER-alpha) have increased incidence of resistance to therapy and poorer clinical prognosis.<h4>Methods</h4>Whole tissue sections from 16 cryopreserved breast cancer tumors that were either positive or negative for the ER (eight ER positive and eight ER negative) were differentially analyzed by multiplex imaging of two-dimensional PAGE gels using 54 cm isoelectric focusing. Differentially detected spots of Progesterone Receptor Membrane Component 1 (PGRMC1) were shown to differ in phosphorylation status by differential two dimensional polyacrylamide gel electrophoresis of phosphatase-treated tumor proteins. Site directed mutagenesis was used to create putative phosphorylation site point mutants in PGRMC1. Stable transfectants of these mutants in MCF7 cells were assayed for their survival after oxidative stress, and for AKT kinase phosphorylation. Immune fluorescence using anti-PGRMC1 monoclonal antibody 5G7 was performed on breast cancer tissue microarrays.<h4>Results</h4>Proteins significantly differentially abundant between estrogen receptor negative and estrogen receptor positive tumors at the 0.1% level were consistent with published profiles, suggesting an altered keratin pool, and increased inflammation and wound responses in estrogen receptor negative tumors. Two of three spots of PGRMC1 were more abundant in estrogen receptor negative tumors. Phosphatase treatment of breast tumor proteins indicated that the PGRMC1 isoforms differed in their phosphorylation status. Simultaneous mutation of PGRMC1 serine-56 and serine-180 [corrected] fully abrogated the sensitivity of stably transfected MCF7 breast cancer cells to peroxide-induced cell death. Immune fluorescence revealed that PGRMC1 was primarily expressed in ER-negative basal epithelial cells of mammary ductules. Even in advanced tumors, high levels of ER or PGRMC1 were almost mutually exclusive in individual cells. In five out of five examined ductal in situ breast cancers of comedo type, PGRMC1 was expressed in glucose transporter 1 negative or positive poorly oxygenated cells surrounding the necrotic core, surrounded by a more distal halo of ER-positive cells.<h4>Conclusions</h4>PGRMC1 phosphorylation may be involved in the clinical differences that underpin breast tumors of differing ER status.
…mammalian homolog, Staufen1 (Stau1), has been implicated…
Abstract)
…functions, the murineStau1gene was disrupted…
Abstract)
…express a truncatedStau1protein lacking the…
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The dsRNA-binding protein Staufen was the first RNA-binding protein proven to play a role in RNA localization in Drosophila. A mammalian homolog, Staufen1 (Stau1), has been implicated in dendritic RNA localization in neurons, translational control, and mRNA decay. However, the precise mechanisms by which it fulfills these specific roles are only partially understood. To determine its physiological functions, the murine Stau1 gene was disrupted by homologous recombination. Homozygous stau1(tm1Apa) mutant mice express a truncated Stau1 protein lacking the functional RNA-binding domain 3. The level of the truncated protein is significantly reduced. Cultured hippocampal neurons derived from stau1(tm1Apa) homozygous mice display deficits in dendritic delivery of Stau1-EYFP and beta-actin mRNA-containing ribonucleoprotein particles (RNPs). Furthermore, these neurons have a significantly reduced dendritic tree and develop fewer synapses. Homozygous stau1(tm1Apa) mutant mice are viable and show no obvious deficits in development, fertility, health, overall brain morphology, and a variety of behavioral assays, e.g., hippocampus-dependent learning. However, we did detect deficits in locomotor activity. Our data suggest that Stau1 is crucial for synapse development in vitro but not critical for normal behavioral function.
Also flagged:dopaminepathogenesisParkinson diseasepolyunsaturated fatty acidsfatty acidhydroperoxides
Journal Article2008-10-15✓ 1 SnippetLiu X, Yamada N, Maruyama W, Osawa T.
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…5-HTT…
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Oxidative stress appears to be directly involved in the pathogenesis of the neurodegeneration of dopaminergic systems in Parkinson disease. In this study, we formed four dopamine modification adducts derived from docosahexaenoic acid (C22:6/omega-3) and arachidonic acid (C18:4/omega-6), which are known as the major polyunsaturated fatty acids in the brain. Upon incubation of dopamine with fatty acid hydroperoxides and an in vivo experiment using rat brain tissue, all four dopamine adducts were detected. Furthermore, hexanoyl dopamine (HED), an arachidonic acid-derived adduct, caused severe cytotoxicity in human dopaminergic neuroblastoma SH-SY5Y cells, whereas the other adducts were only slightly affected. The HED-induced cell death was found to include apoptosis, which also seems to be mediated by reactive oxygen species generation and mitochondrial abnormality. Additionally, the experiments using monoamine transporter inhibitor and mouse embryonic fibroblast NIH-3T3 cells that lack the monoamine transporter indicate that the HED-induced cytotoxicity might specially occur in the neuronal cells. These data suggest that the formation of the docosahexaenoic acid- and arachidonic acid-derived dopamine adducts in vitro and in vivo, and HED, the arachidonic acid-derived dopamine modification adduct, which caused selective cytotoxicity of neuronal cells, may indicate a novel mechanism responsible for the pathogenesis in Parkinson disease.
Also flagged:HuntingtinRESTNRSFRILPtranscriptional repressorREST/NRSF-interacting LIM domain protein
Journal Article2008-10-15No SnippetsShimojo M.
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Huntingtin has been reported to regulate the nuclear translocation of the transcriptional repressor RE1-silencing transcription factor/neuron-restrictive silencer factor (REST/NRSF). The REST/NRSF-interacting LIM domain protein (RILP) has also been shown to regulate REST/NRSF nuclear translocation. Therefore, we were prompted to address the question of how two distinct proteins could have the same function. We initially used a yeast two-hybrid screen to look for an interaction between huntingtin and RILP. This screen identified dynactin p150(Glued) as an interacting protein. Coimmunoprecipitation of proteins in vitro expressed in a reticulocyte lysate system showed an interaction between REST/NRSF and RILP as well as between RILP and dynactin p150(Glued). Coimmunoprecipitation analysis further showed a complex containing RILP, dynactin p150(Glued), and huntingtin. Huntingtin did not interact directly with either REST/NRSF or RILP, but did interact with dynactin p150(Glued). The N-terminal fragment of wild-type huntingtin did not affect the interaction between dynactin p150(Glued) and RILP; however, mutant huntingtin weakened this interaction. We further show that HAP1 (huntingtin-associated protein-1) prevents this complex from translocating REST/NRSF to the nucleus. Thus, this study suggests that REST/NRSF, dynactin p150(Glued), huntingtin, HAP1, and RILP form a complex involved in the translocation of REST/NRSF into the nucleus and that HAP1 controls REST/NRSF cellular localization in neurons.
The completion of chromosome segregation during anaphase requires the hypercondensation of the approximately 1-Mb rDNA array, a reaction dependent on condensin and Cdc14 phosphatase. Using systematic genetic screens, we identified 29 novel genetic interactions with budding yeast condensin. Of these, FOB1, CSM1, LRS4, and TOF2 were required for the mitotic condensation of the tandem rDNA array localized on chromosome XII. Interestingly, whereas Fob1 and the monopolin subunits Csm1 and Lrs4 function in rDNA condensation throughout M phase, Tof2 was only required during anaphase. We show that Tof2, which shares homology with the Cdc14 inhibitor Net1/Cfi1, interacts with Cdc14 phosphatase and its deletion suppresses defects in mitotic exit network (MEN) components. Consistent with these genetic data, the onset of Cdc14 release from the nucleolus was similar in TOF2 and tof2Delta cells; however, the magnitude of the release was dramatically increased in the absence of Tof2, even when the MEN pathway was compromised. These data support a model whereby Tof2 coordinates the biphasic release of Cdc14 during anaphase by restraining a population of Cdc14 in the nucleolus after activation of the Cdc14 early anaphase release (FEAR) network, for subsequent release by the MEN.
Also flagged:NODALATKPTENBMPtranscription factorsFOX
Journal Article2008-10-15No SnippetsSun Y, Li H, Liu Y, Mattson MP, Rao MS, Zhan M.
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<h4>Background</h4>Understanding the molecular mechanisms controlling pluripotency in embryonic stem cells (ESCs) is of central importance towards realizing their potentials in medicine and science. Cross-species examination of transcriptional co-expression allows elucidation of fundamental and species-specific mechanisms regulating ESC self-renewal or differentiation.<h4>Methodology/principal findings</h4>We examined transcriptional co-expression of ESCs from pathways to global networks under the framework of human-mouse comparisons. Using generalized singular value decomposition and comparative partition around medoids algorithms, evolutionarily conserved and divergent transcriptional co-expression regulating pluripotency were identified from ESC-critical pathways including ACTIVIN/NODAL, ATK/PTEN, BMP, CELL CYCLE, JAK/STAT, PI3K, TGFbeta and WNT. A set of transcription factors, including FOX, GATA, MYB, NANOG, OCT, PAX, SOX and STAT, and the FGF response element were identified that represent key regulators underlying the transcriptional co-expression. By transcriptional intervention conducted in silico, dynamic behavior of pathways was examined, which demonstrate how much and in which specific ways each gene or gene combination effects the behavior transition of a pathway in response to ESC differentiation or pluripotency induction. The global co-expression networks of ESCs were dominated by highly connected hub genes such as IGF2, JARID2, LCK, MYCN, NASP, OCT4, ORC1L, PHC1 and RUVBL1, which are possibly critical in determining the fate of ESCs.<h4>Conclusions/significance</h4>Through these studies, evolutionary conservation at genomic, transcriptomic, and network levels is shown to be an effective predictor of molecular factors and mechanisms controlling ESC development. Various hypotheses regarding mechanisms controlling ESC development were generated, which could be further validated by in vitro experiments. Our findings shed light on the systems-level understanding of how ESC differentiation or pluripotency arises from the connectivity or networks of genes, and provide a "road-map" for further experimental investigation.
Also flagged:Neuropeptidesmonoaminedepressionbrain-derived neurotrophic factorBDNFcAMP response element binding protein
Journal Article2008-10-15No SnippetsThakker-Varia S, Alder J.
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The monoamine hypothesis of depression is increasingly called into question by newer theories that revolve around changes in neuronal plasticity, primarily in the hippocampus, at both the structural and the functional levels. Chronic stress negatively regulates hippocampal function while antidepressants ameliorate the effects of stress on neuronal morphology and activity. Both stress and antidepressants have been shown to affect levels of brain-derived neurotrophic factor (BDNF) whose transcription is dependent on cAMP response element binding protein (CREB). BDNF itself has antidepressant-like actions and can induce transcription of a number of molecules. One class of genes regulated by both BDNF and serotonin (5-HT) are neuropeptides including VGF (non-acryonimic) which has a novel role in depression. Neuropeptides are important modulators of neuronal function but their role in affective disorders is just emerging. Recent studies demonstrate that VGF, which is also a CREB-dependent gene, is upregulated by antidepressant drugs and voluntary exercise and is reduced in animal models of depression. VGF enhances hippocampal synaptic plasticity as well as neurogenesis in the dentate gyrus but the mechanisms of antidepressant-like actions of VGF in behavioral paradigms are not known. We summarize experimental data describing the roles of BDNF, VGF and other neuropeptides in depression and how they may be acting through the generation of new neurons and altered synaptic activity. Understanding the molecular and cellular changes that underlie the actions of neuropeptides and how these adaptations result in antidepressant-like effects will aid in developing drugs that target novel pathways for major depressive disorders.
Also flagged:amideanthracenepiperidinepiperidinmethanoneacetyl-coenzyme A carboxylases
Journal Article2008-10-15No SnippetsHu HY, Huang YC, Yu HT, Zhang Y.
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The title compound, C(20)H(19)NO, is a substructure of CP-640186, a potent inhibitor of mammalian acetyl-coenzyme A carboxyl-ases. In the crystal structure, the amide group forms a dihedral angle of 87.0 (1)° with the plane of the anthracene unit and the piperidine ring adopts a chair conformation. Mol-ecules are arranged into layers parallel to (100) and adjacent anthracene units within layers form dihedral angles of 13.2 (1)°. C-H⋯O inter-actions from the piperidine rings to the C=O group of the amide are observed between layers.
Adiponectin, an adipokine secreted by the white adipose tissue, plays an important role in regulating glucose and lipid metabolism and controlling energy homeostasis in insulin-sensitive tissues. A decrease in the circulating level of adiponectin has been linked to insulin resistance, type 2 diabetes, atherosclerosis, and metabolic syndrome. Adiponectin exerts its effects through two membrane receptors, AdipoR1 and AdipoR2. APPL1 is the first identified protein that interacts directly with adiponectin receptors. APPL1 is an adaptor protein with multiple functional domains, the Bin1/amphiphysin/rvs167, pleckstrin homology, and phosphotyrosine binding domains. The PTB domain of APPL1 interacts directly with the intracellular region of adiponectin receptors. Through this interaction, APPL1 mediates adiponectin signaling and its effects on metabolism. APPL1 also functions in insulin-signaling pathway and is an important mediator of adiponectin-dependent insulin sensitization in skeletal muscle. Adiponectin signaling through APPL1 is necessary to exert its anti-inflammatory and cytoprotective effects on endothelial cells. APPL1 also acts as a mediator of other signaling pathways by interacting directly with membrane receptors or signaling proteins, thereby playing critical roles in cell proliferation, apoptosis, cell survival, endosomal trafficking, and chromatin remodeling. This review focuses mainly on our current understanding of adiponectin signaling in various tissues, the role of APPL1 in mediating adiponectin signaling, and also its role in the cross-talk between adiponectin/insulin-signaling pathways.
Also flagged:KLK6KLK10tumourcancerpancreatic ductal adenocarcinomaPDAC
Journal Article2008-10-14No SnippetsRückert F, Hennig M, Petraki CD, Wehrum D, Distler M, Denz A, Schröder M, Dawelbait G, Kalthoff H, Saeger HD, Diamandis EP, Pilarsky C, Grützmann R.
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Kallikreins play an important role in tumour microenvironment and as cancer biomarkers in different cancer entities. Previous studies suggested an upregulation of KLK10 and KLK6 in pancreatic ductal adenocarcinoma (PDAC). Therefore, we evaluated the clinicopathological role of these kallikreins and their value as biomarkers in PDAC.Differential expression was validated by DNA-microarrays and immunohistochemistry in normal and malignant pancreatic tissues. Sera concentrations of both kallikreins were evaluated using ELISA. In silico analysis of possible protein interactions and gene silencing of KLK10 in vitro using siRNAs gave further insights in the pathomechanisms.Gene expression analysis and immunohistochemistry demonstrated a strong expression for KLK10 and KLK6 in PDAC. Statistical analysis showed that co-expression of these kallikreins correlated with an R1-resection status (P=0.017) and worse outcome for overall survival (P=0.031). Multivariate analysis proofed that co-expression is an independent prognostic factor for survival (P=0.043). Importantly, KLK10 knockdown in AsPC-1 cells significantly reduced cell migration, whereas computational analysis suggested interaction of KLK6 with angiogenetic factors as an important mechanism.Co-expression of KLK10 and KLK6 plays an unfavourable role in PDAC. Our results suggest that this effect is likely mediated by an interaction with the factors of the extracellular matrix and enhancement of cancer cell motility.
Also flagged:oxygensignal transductiongene expressionredoxpathogenesiswound healing
Journal Article2008-10-13✓ 1 SnippetNovo E, Parola M.
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S I O 001029)
…However, with regard to patients with chronic HCV infection, it has been proposed that mutations in the hereditary hemochromatosis HFE gene may be responsible not only for derangement of iron homeostasis and HH, but may also worsen or accelerate the course of CLD by eliciting a turn-over of redox active iron in both the liver and plasma; in other words, the hypothesis is that HFE mutations may additionally result in increased intracellular production of ROS and free radicals taking place in hepatocytes or, also on the basis of recent knowledge on the role of hepcidin (see the section 'ROS-dependent sustained activation of JNK: a common step in oxidative stress-dependent cell death') and the iron transporter ferroportin, may affect the ability of Kupffer cells to handle and retain iron [112,114,115].…
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Reactive oxygen species (ROS) generated within cells or, more generally, in a tissue environment, may easily turn into a source of cell and tissue injury. Aerobic organisms have developed evolutionarily conserved mechanisms and strategies to carefully control the generation of ROS and other oxidative stress-related radical or non-radical reactive intermediates (that is, to maintain redox homeostasis), as well as to 'make use' of these molecules under physiological conditions as tools to modulate signal transduction, gene expression and cellular functional responses (that is, redox signalling). However, a derangement in redox homeostasis, resulting in sustained levels of oxidative stress and related mediators, can play a significant role in the pathogenesis of major human diseases characterized by chronic inflammation, chronic activation of wound healing and tissue fibrogenesis. This review has been designed to first offer a critical introduction to current knowledge in the field of redox research in order to introduce readers to the complexity of redox signalling and redox homeostasis. This will include ready-to-use key information and concepts on ROS, free radicals and oxidative stress-related reactive intermediates and reactions, sources of ROS in mammalian cells and tissues, antioxidant defences, redox sensors and, more generally, the major principles of redox signalling and redox-dependent transcriptional regulation of mammalian cells. This information will serve as a basis of knowledge to introduce the role of ROS and other oxidative stress-related intermediates in contributing to essential events, such as the induction of cell death, the perpetuation of chronic inflammatory responses, fibrogenesis and much more, with a major focus on hepatic chronic wound healing and liver fibrogenesis.
H1 and HMGB1 bind to linker DNA in chromatin, in the vicinity of the nucleosome dyad. They appear to have opposing effects on the nucleosome, H1 stabilising it by "sealing" two turns of DNA around the octamer, and HMGB1 destabilising it, probably by bending the adjacent DNA. Their presence in chromatin might be mutually exclusive. Displacement/replacement of one by the other as a result of their highly dynamic binding in vivo might, in principle, involve interactions between them. Chemical cross-linking and gel-filtration show that a 1:1 linker histone/HMGB1 complex is formed, which persists at physiological ionic strength, and that complex formation requires the acidic tail of HMGB1. NMR spectroscopy shows that the linker histone binds, predominantly through its basic C-terminal domain, to the acidic tail of HMGB1, thereby disrupting the interaction of the tail with the DNA-binding faces of the HMG boxes. A potential consequence of this interaction is enhanced DNA binding by HMGB1, and concomitantly lowered affinity of H1 for DNA. In a chromatin context, this might facilitate displacement of H1 by HMGB1.
It has been known for at least 20 years that growth factors induce the internalization of cognate receptor tyrosine kinases (RTKs). The internalized receptors are then sorted to lysosomes or recycled to the cell surface. More recently, data have been published to indicate other intracellular destinations for the internalized RTKs. These include the nucleus, mitochondria, and cytoplasm. Also, it is recognized that trafficking to these novel destinations involves new biochemical mechanisms, such as proteolytic processing or interaction with translocons, and that these trafficking events have a function in signal transduction, implicating the receptor itself as a signaling element between the cell surface and the nucleus.
Also flagged:Aspmetal-bindingMetaphasealas2Cancerbright
Journal Article2008-10-10✓ 1 SnippetImamura S, Uchiyama J, Koshimizu E, Hanai J, Raftopoulou C, Murphey RD, Bayliss PE, Imai Y, Burns CE, Masutomi K, Gagos S, Zon LI, Roberts TM, Kishi S.
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Introduction)
…epatoerythropoietic porphyria,hemochromatosis, and myelodysplastic syndrome…
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Although it is clear that telomerase expression is crucial for the maintenance of telomere homeostasis, there is increasing evidence that the TERT protein can have physiological roles that are independent of this central function. To further examine the role of telomerase during vertebrate development, the zebrafish telomerase reverse transcriptase (zTERT) was functionally characterized. Upon zTERT knockdown, zebrafish embryos show reduced telomerase activity and are viable, but develop pancytopenia resulting from aberrant hematopoiesis. The blood cell counts in TERT-depleted zebrafish embryos are markedly decreased and hematopoietic cell differentiation is impaired, whereas other somatic lineages remain morphologically unaffected. Although both primitive and definitive hematopoiesis is disrupted by zTERT knockdown, the telomere lengths are not significantly altered throughout early development. Induced p53 deficiency, as well as overexpression of the anti-apoptotic proteins Bcl-2 and E1B-19K, significantly relieves the decreased blood cells numbers caused by zTERT knockdown, but not the impaired blood cell differentiation. Surprisingly, only the reverse transcriptase motifs of zTERT are crucial, but the telomerase RNA-binding domain of zTERT is not required, for rescuing complete hematopoiesis. This is therefore the first demonstration of a non-canonical catalytic activity of TERT, which is different from "authentic" telomerase activity, is required for during vertebrate hematopoiesis. On the other hand, zTERT deficiency induced a defect in hematopoiesis through a potent and specific effect on the gene expression of key regulators in the absence of telomere dysfunction. These results suggest that TERT non-canonically functions in hematopoietic cell differentiation and survival in vertebrates, independently of its role in telomere homeostasis. The data also provide insights into a non-canonical pathway by which TERT functions to modulate specification of hematopoietic stem/progenitor cells during vertebrate development. (276 words).
Also flagged:localizationsGFPlocalizationSUMOE3sumoylation
Journal Article2008-10-10✓ 2 SnippetsTakahashi Y, Dulev S, Liu X, Hiller NJ, Zhao X, Strunnikov A.
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…Condensinand Cohesin Are…
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…CondensinSumoylation Is Essential…
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SUMO is a posttranslational modifier that can modulate protein activities, interactions, and localizations. As the GFP-Smt3p fusion protein has a preference for subnucleolar localization, especially when deconjugation is impaired, the nucleolar role of SUMO can be the key to its biological functions. Using conditional triple SUMO E3 mutants, we show that defects in sumoylation impair rDNA maintenance, i.e., the rDNA segregation is defective and the rDNA copy number decreases in these mutants. Upon characterization of sumoylated proteins involved in rDNA maintenance, we established that Top1p and Top2p, which are sumoylated by Siz1p/Siz2p, most likely collaborate with substrates of Mms21p to maintain rDNA integrity. Cohesin and condensin subunits, which both play important roles in rDNA stability and structures, are potential substrates of Mms21, as their sumoylation depends on Mms21p, but not Siz1p and Siz2p. In addition, binding of cohesin and condensin to rDNA is altered in the mms21-CH E3-deficient mutant.
Also flagged:Hereditary haemochromatosisinfertileFollicle Stimulating HormoneLuteinizing HormoneLHTestosterone
Journal Article2008-10-10✓ 5 SnippetsGunel-Ozcan A, Basar MM, Kisa U, Ankarali HC.
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Abstract)
…Thus, the HFE H63D mutation seems to be an important risk factor for impaired sperm motility and is clinically associated with male infertility.…
Abstract)
…The aim of this study was to screen infertile men for HFE H63D mutation in correlation with clinical characteristics of infertile men (sperm concentration, sperm motility, morphology, testicular volume, Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH) and total Testosterone levels) and find out if the HFE H63D mutation has an effect on male infertility.…
Abstract)
…Our analysis indicates that the mean FSH levels are significantly higher (6.3 +/- 4.6 mIU/ml, P = 0.03), whereas sperm motility is significantly lower (36.6 +/- 28.1%, P = 0.01) in the infertile men with the HFE H63D mutation compared with subjects lacking this mutation.…
The aim of this study was to screen infertile men for HFE H63D mutation in correlation with clinical characteristics of infertile men (sperm concentration, sperm motility, morphology, testicular volume, Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH) and total Testosterone levels) and find out if the HFE H63D mutation has an effect on male infertility. After excluding hormonal treatment, any scrotal pathology, having any systemic diseases such as diabetes mellitus, sickle cell anemia and microdeletions of the Y chromosome, a total of 148 infertile men with age range between 17 and 52-years-old (average age 29.6 +/- 7.2) were enrolled into the study. Our analysis indicates that the mean FSH levels are significantly higher (6.3 +/- 4.6 mIU/ml, P = 0.03), whereas sperm motility is significantly lower (36.6 +/- 28.1%, P = 0.01) in the infertile men with the HFE H63D mutation compared with subjects lacking this mutation. Comparison of allele frequencies of the infertile men with Ts < 50% versus the infertile men with Ts > 50% revealed a significant difference as expected (P = 0.001, OR = 0.14, %95 CI = 0.04-0.44). Comparison of allele frequencies of infertile men with abnormal sperm motility versus infertile men with normal sperm motility revealed a highly significant difference (P = 0.005, OR = 3.11, %95 CI = 1.41-6.86). Thus, the HFE H63D mutation seems to be an important risk factor for impaired sperm motility and is clinically associated with male infertility.
Polyglutamine (polyQ) expansion leads to protein aggregation and neurodegeneration in Huntington's disease and eight other inherited neurological conditions. Expansion of the polyQ tract beyond a threshold of 37 glutamines leads to the formation of toxic nuclear aggregates. This suggests that polyQ expansion causes a conformational change within the protein, the nature of which is unclear. There is a trend in the disease proteins that the polyQ tract is located external to but not within a structured domain. We have created a model polyQ protein in which the repeat location mimics the flexible environment of the polyQ tract in the disease proteins. Our model protein recapitulates the aggregation features observed with the clinical proteins and allows structural characterization. With the use of NMR spectroscopy and a range of biophysical techniques, we demonstrate that polyQ expansion into the pathological range has no effect on the structure, dynamics, and stability of a domain adjacent to the polyQ tract. To explore the clinical significance of repeat location, we engineered a variant of the model protein with a polyQ tract within the domain, a location that does not mimic physiological context, demonstrating significant destabilization and structural perturbation. These different effects highlight the importance of repeat location. We conclude that protein misfolding within the polyQ tract itself is the driving force behind the key characteristics of polyQ disease, and that structural perturbation of flanking domains is not required.
Mesenchymal stem cells (MSCs), the nonhematopoietic progenitor cells found in various adult tissues, are characterized by their ease of isolation and their rapid growth in vitro while maintaining their differentiation potential, allowing for extensive culture expansion to obtain large quantities suitable for therapeutic use. These properties make MSCs an ideal candidate cell type as building blocks for tissue engineering efforts to regenerate replacement tissues and repair damaged structures as encountered in various arthritic conditions. Osteoarthritis (OA) is the most common arthritic condition and, like rheumatoid arthritis (RA), presents an inflammatory environment with immunological involvement and this has been an enduring obstacle that can potentially limit the use of cartilage tissue engineering. Recent advances in our understanding of the functions of MSCs have shown that MSCs also possess potent immunosuppression and anti-inflammation effects. In addition, through secretion of various soluble factors, MSCs can influence the local tissue environment and exert protective effects with an end result of effectively stimulating regeneration in situ. This function of MSCs can be exploited for their therapeutic application in degenerative joint diseases such as RA and OA. This review surveys the advances made in the past decade which have led to our current understanding of stem cell biology as relevant to diseases of the joint. The potential involvement of MSCs in the pathophysiology of degenerative joint diseases will also be discussed. Specifically, we will explore the potential of MSC-based cell therapy of OA and RA by means of functional replacement of damaged cartilage via tissue engineering as well as their anti-inflammatory and immunosuppressive activities.
Also flagged:Vitamin CC-reactive proteinCRPcardiovascular diseasevitamin Estatins
Journal Article2008-10-10✓ 1 SnippetBlock G, Jensen CD, Dalvi TB, Norkus EP, Hudes M, Crawford PB, Holland N, Fung EB, Schumacher L, Harmatz P.
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…hemochromatosis…
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Plasma C-reactive protein (CRP) is an inflammatory biomarker that predicts cardiovascular disease. Lowering elevated CRP with statins has reduced the incidence of cardiovascular disease. We investigated whether vitamin C or E could reduce CRP. Healthy nonsmokers (N=396) were randomized to three groups, 1000 mg/day vitamin C, 800 IU/day vitamin E, or placebo, for 2 months. Median baseline CRP was low, 0.85 mg/L. No treatment effect was seen when all participants were included. However, a significant interaction was found, indicating that treatment effect depends on baseline CRP concentration. Among participants with CRP indicative of elevated cardiovascular risk (> or =1.0 mg/L), vitamin C reduced the median CRP by 25.3% vs placebo (p=0.02) (median reduction in the vitamin C group, 0.25 mg/L, 16.7%). These effects are similar to those of statins. The vitamin E effect was not significant. In summary, treatment with vitamin C but not vitamin E significantly reduced CRP among individuals with CRP > or =1.0 mg/L. Among the obese, 75% had CRP > or =1.0 mg/L. Research is needed to determine whether reducing this inflammatory biomarker with vitamin C could reduce diseases associated with obesity. But research on clinical benefits of antioxidants should limit participants to persons with elevations in the target biomarkers.
Also flagged:Nrf2dopaminesynthesisautosomal dominant neurodegenerative disorderHDHuntington's disease
Journal Article2008-10-09✓ 1 Snippetvan Roon-Mom WM, Pepers BA, 't Hoen PA, Verwijmeren CA, den Dunnen JT, Dorsman JC, van Ommen GB.
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…Hmox1, Taldo1 andPrdx6were down-regulated.…
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<h4>Background</h4>Huntington's disease is a progressive autosomal dominant neurodegenerative disorder that is caused by a CAG repeat expansion in the HD or Huntington's disease gene. Although micro array studies on patient and animal tissue provide valuable information, the primary effect of mutant huntingtin will inevitably be masked by secondary processes in advanced stages of the disease. Thus, cell models are instrumental to study early, direct effects of mutant huntingtin. mRNA changes were studied in an inducible PC12 model of Huntington's disease, before and after aggregates became visible, to identify groups of genes that could play a role in the early pathology of Huntington's disease.<h4>Results</h4>Before aggregation, up-regulation of gene expression predominated, while after aggregates became visible, down-regulation and up-regulation occurred to the same extent. After aggregates became visible there was a down-regulation of dopamine biosynthesis genes accompanied by down-regulation of dopamine levels in culture, indicating the utility of this model to identify functionally relevant pathways. Furthermore, genes of the anti-oxidant Nrf2-ARE pathway were up-regulated, possibly as a protective mechanism. In parallel, we discovered alterations in genes which may result in increased oxidative stress and damage.<h4>Conclusion</h4>Up-regulation of gene expression may be more important in HD pathology than previously appreciated. In addition, given the pathogenic impact of oxidative stress and neuroinflammation, the Nrf2-ARE signaling pathway constitutes a new attractive therapeutic target for HD.
<h4>Background</h4>Geobacter species are delta-Proteobacteria and are often the predominant species in a variety of sedimentary environments where Fe(III) reduction is important. Their ability to remediate contaminated environments and produce electricity makes them attractive for further study. Cell motility, biofilm formation, and type IV pili all appear important for the growth of Geobacter in changing environments and for electricity production. Recent studies in other bacteria have demonstrated that signaling pathways homologous to the paradigm established for Escherichia coli chemotaxis can regulate type IV pili-dependent motility, the synthesis of flagella and type IV pili, the production of extracellular matrix material, and biofilm formation. The classification of these pathways by comparative genomics improves the ability to understand how Geobacter thrives in natural environments and better their use in microbial fuel cells.<h4>Results</h4>The genomes of G. sulfurreducens, G. metallireducens, and G. uraniireducens contain multiple (approximately 70) homologs of chemotaxis genes arranged in several major clusters (six, seven, and seven, respectively). Unlike the single gene cluster of E. coli, the Geobacter clusters are not all located near the flagellar genes. The probable functions of some Geobacter clusters are assignable by homology to known pathways; others appear to be unique to the Geobacter sp. and contain genes of unknown function. We identified large numbers of methyl-accepting chemotaxis protein (MCP) homologs that have diverse sensing domain architectures and generate a potential for sensing a great variety of environmental signals. We discuss mechanisms for class-specific segregation of the MCPs in the cell membrane, which serve to maintain pathway specificity and diminish crosstalk. Finally, the regulation of gene expression in Geobacter differs from E. coli. The sequences of predicted promoter elements suggest that the alternative sigma factors sigma28 and sigma54 play a role in regulating the Geobacter chemotaxis gene expression.<h4>Conclusion</h4>The numerous chemoreceptors and chemotaxis-like gene clusters of Geobacter appear to be responsible for a diverse set of signaling functions in addition to chemotaxis, including gene regulation and biofilm formation, through functionally and spatially distinct signaling pathways.
Also flagged:major depressive disorderSerotonin transporter5-HT receptor5-HTR-major depression disorder
Journal Article2008-10-09✓ 3 SnippetsZhang K, Xu Q, Xu Y, Yang H, Luo J, Sun Y, Sun N, Wang S, Shen Y.
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Abstract)
…<h4>Background</h4>Serotonin transporter (5-HTT) and 5-HT receptor (5-HTR) involved in the neurotransmission of 5-HT may play an important role in the development of major depression disorder (MDD).…
Abstract)
…nd</h4>Serotonin transporter (5-HTT) and 5-HT receptor…
<h4>Background</h4>Serotonin transporter (5-HTT) and 5-HT receptor (5-HTR) involved in the neurotransmission of 5-HT may play an important role in the development of major depression disorder (MDD). Several lines of evidence suggested that the gene-environment interaction may confer susceptibility to depression. The aim of this study is to analyze the combined effect of four serotonin-related genes and two environmental factors on MDD in a Chinese population.<h4>Methods</h4>This study recruited a total of 401 patients with MDD and 391 age- and gender-matched control subjects. They were all Chinese Han origin. Negative life events and objective social supports were assessed using standard rating scales. Six polymorphisms in the four serotonin-related genes (5-HTT, 5-HTR1A, 5-HTR1B and 5-HTR2A) were selected to detect. The analyses of the gene-environment interactions were performed by the Multifactor Dimensionality Reduction (MDR).<h4>Results</h4>Allelic associations between patients with MDD and controls were observed for the polymorphism of 5-HTTLPR and for rs6295 at the 5-HTR1A locus. The 5-HTTLPR polymorphism was associated with negative life events on MDD. A three-way interaction between the 5-HTTLPR polymorphism, rs6295 and negative life events on MDD was found in the individuals aged from 20 years to 29 years. In addition, the individuals carrying the L/L genotype of 5-HTTLPR could be susceptible to MDD when exposed to negative life events.<h4>Conclusions</h4>The 5-HTTLPR polymorphism may modify the interaction between negative life events and MDD in the Chinese population. To our knowledge, this is the first report on the combined effect for the 5-HTTLPR polymorphism and 5-HTR1A genes on modifying the response to negative life events conferring susceptibility to MDD in the 20-29 year group.
Also flagged:Peroxiredoxin 6phospholipidhydroperoxidesNrf2transcription factornucleotides
Journal Article2008-10-09✓ 5 SnippetsChowdhury I, Mo Y, Gao L, Kazi A, Fisher AB, Feinstein SI.
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Abstract)
…These data demonstrate that the ARE within the Prdx6 promoter is a key regulator of basal transcription of the Prdx6 gene and of its inducibility under conditions of oxidative stress.…
Abstract)
…Cotransfection with Nrf2 stimulated the Prdx6 promoter in an ARE-dependent manner, whereas it was negatively regulated by Nrf3.…
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…Peroxiredoxin 6 (Prdx6) is a unique…
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…line, express bothPrdx6and Nrf2, a…
Abstract)
…of the humanPrdx6promoter region.…
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Peroxiredoxin 6 (Prdx6) is a unique antioxidant enzyme that can reduce phospholipid and other hydroperoxides. A549 cells, a human lung-derived cell line, express both Prdx6 and Nrf2, a transcription factor that binds to antioxidant-response elements (AREs) and promotes expression of antioxidant genes. Treatment of A549 cells with 500 microM H(2)O(2) increased Prdx6 mRNA levels 2.5-fold, whereas treatment with 400 microM H(2)O(2) or 200 microM tert-butylhydroquinone (t-BHQ) triggered a corresponding 2.5-fold increase in reporter gene activity in A549 cells transfected with the pSEAP2:Basic vector (BD Bioscience), containing 1524 nucleotides of the human Prdx6 promoter region. Deletion of a consensus ARE sequence present between positions 357 and 349 before the start of transcription led to a striking decrease in both basal and H(2)O(2)- or t-BHQ-induced activation in A549 cells and H(2)O(2)-induced activation in primary rat alveolar type II cells. Cotransfection with Nrf2 stimulated the Prdx6 promoter in an ARE-dependent manner, whereas it was negatively regulated by Nrf3. siRNA targeting Nrf2 down-regulated reporter gene expression, whereas siRNA targeting the Nrf2 repressor, Keap1, up-regulated it. Binding of Nrf2 to the ARE sequence in chromatin was confirmed by PCR after chromatin immunoprecipitation. These data demonstrate that the ARE within the Prdx6 promoter is a key regulator of basal transcription of the Prdx6 gene and of its inducibility under conditions of oxidative stress.
Also flagged:homovanillic acidprolactinHuntington's diseaseHDdementiadepression
Journal Article2008-10-08No SnippetsMarkianos M, Panas M, Kalfakis N, Vassilopoulos D.
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Dopaminergic activity is expected to be altered in patients with Huntington's disease (HD) and be related to factors like duration and severity of illness or patients' specific symptomatology like dementia, depression, or psychotic features. We assessed plasma homovanillic acid (pHVA) and plasma prolactin (pPRL), two correlates of dopaminergic activity, in 116 subjects with CAG repeats expansion in the HD gene, 26 presymptomatic (18 females) and 90 with overt symptomatology (43 females). Patients were evaluated using the Unified HD Rating Scale and the Total Functional Capacity Scale. Presence of dementia, depression, and psychotic features were also assessed. The age range of the patients was 22-83 years, duration of illness from 0.5 to 27 years, and CAG repeat number from 34 to 66. A group of 60 age and sex matched healthy subjects served as control group. Plasma PRL in subjects at risk and in neuroleptic-free patients, evaluated separately for males and females, did not differ from controls. Plasma HVA levels did not differ from controls in the group of presymptomatic subjects, but were significantly higher in the patients group. This increase was positively associated mainly with severity of illness and functional capacity of the patients, and not with presence of depression or dementia. Plasma HVA levels may be proven to be a peripheral index of disease progression. Reducing dopaminergic activity may have not only symptomatic, but also neuroprotective effects in HD.
Also flagged:Alzheimer's diseasegene expressionbindingtranscription factorscardiovascular diseasecardiovascular diseases
Journal Article2008-10-08✓ 2 SnippetsRay M, Ruan J, Zhang W.
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…peroxiredoxin 6 (PRDX6) - have…
Results)
…, NFKBIA ,PRDX6, TSC22D4 and…
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<h4>Background</h4>Because of its polygenic nature, Alzheimer's disease is believed to be caused not by defects in single genes, but rather by variations in a large number of genes and their complex interactions. A systems biology approach, such as the generation of a network of co-expressed genes and the identification of functional modules and cis-regulatory elements, to extract insights and knowledge from microarray data will lead to a better understanding of complex diseases such as Alzheimer's disease. In this study, we perform a series of analyses using co-expression networks, cis-regulatory elements, and functions of co-expressed gene modules to analyze single-cell gene expression data from normal and Alzheimer's disease-affected subjects.<h4>Results</h4>We identified six co-expressed gene modules, each of which represented a biological process perturbed in Alzheimer's disease. Alzheimer's disease-related genes, such as APOE, A2M, PON2 and MAP4, and cardiovascular disease-associated genes, including COMT, CBS and WNK1, all congregated in a single module. Some of the disease-related genes were hub genes while many of them were directly connected to one or more hub genes. Further investigation of this disease-associated module revealed cis-regulatory elements that match to the binding sites of transcription factors involved in Alzheimer's disease and cardiovascular disease.<h4>Conclusion</h4>Our results show the extensive links between Alzheimer's disease and cardiovascular disease at the co-expression and co-regulation levels, providing further evidence for the hypothesis that cardiovascular disease and Alzheimer's disease are linked. Our results support the notion that diseases in which the same set of biochemical pathways are affected may tend to co-occur with each other.
<h4>Background and purpose</h4>Malformations of the brain stem are uncommon. We present MR imaging and diffusion tensor imaging (DTI) features of 6 patients with pontine tegmental cap dysplasia, characterized by ventral pontine hypoplasia and a dorsal "bump," and speculate on potential mechanisms by which it forms.<h4>Materials and methods</h4>Birth and developmental records of 6 patients were reviewed. We reviewed MR imaging studies of all patients and DTIs of patient 3. Potential developmental causes were evaluated.<h4>Results</h4>All patients were born uneventfully after normal pregnancies except patient 6 (in utero growth retardation). They presented with multiple cranial neuropathies and evidence of cerebellar dysfunction. Variable hypotonia and motor dysfunction were present. Imaging revealed ventral pontine hypoplasia and mild cerebellar vermian hypoplasia, in addition to an unusual rounded to beaklike "bump" on the dorsal surface of the pons, extending into the fourth ventricle. Color fractional anisotropy maps showed the bump to consist of a bundle of axons directed horizontally (left-right). The bump appeared, on morphologic images, to be continuous with the middle cerebellar peduncles (MCPs), which were slightly diminished in size compared with those in healthy infants. Analysis of the DTI was, however, inconclusive regarding the connections of these axons. The decussation of the MCPs, transverse pontine fibers, and longitudinal brain stem axonal pathways was also abnormal.<h4>Conclusions</h4>Our data suggest that the dorsal transverse axonal band in these disorders results from abnormal axonal pathfinding, abnormal neuronal migration, or a combination of the 2 processes.
Journal Article2008-10-08No SnippetsRawal RK, Katti SB, Kaushik-Basu N, Arora P, Pan Z.
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Hepatitis C virus (HCV) NS5B RNA polymerase is crucial for replicating the HCV RNA genome and is an attractive target for developing anti-HCV drugs. A novel series of 2,3-diaryl-1,3-thiazolidin-4-one derivatives were evaluated for their ability to inhibit HCV NS5B. Of this series, compounds 4c, 5b, 5c and 6 emerged as more potent, displaying over 95% inhibition of NS5B RNA polymerase activity in vitro. The two most active compounds 4c and 5c exhibited an IC(50) of 31.9 microM and 32.2 microM, respectively, against HCV NS5B.
<h4>Purpose</h4>The aim of this study was to evaluate the contribution of amino acid transporters in the transcorneal permeation of the aspartate (Asp) ester acyclovir (ACV) prodrug.<h4>Methods</h4>Physicochemical characterization, solubility and stability of acyclovir L-aspartate (L-Asp-ACV) and acyclovir D-aspartate (D-Asp-ACV) were studied. Transcorneal permeability was evaluated across excised rabbit cornea.<h4>Results</h4>Solubility of L-Asp-ACV and D-Asp-ACV were about twofold higher than that of ACV. The prodrugs demonstrated greater stability under acidic conditions. Calculated pK(a) and logP values for both prodrugs were identical. Transcorneal permeability of L-Asp-ACV (12.1 +/- 1.48 x 10(-6) cm/s) was fourfold higher than D-Asp-ACV (3.12 +/- 0.36 x 10(-6) cm/s) and ACV (3.25 +/- 0.56 x 10(-6) cm/s). ACV generation during the transport process was minimal. L-Asp-ACV transport was sodium and energy dependent but was not inhibited by glutamic acid. Addition of BCH, a specific B(0,+) and L amino acid transporter inhibitor, decreased transcorneal L-Asp-ACV permeability to 2.66 +/- 0.21 x 10(-6) cm/s. L-Asp-ACV and D-Asp-ACV did not demonstrate significant difference in stability in ocular tissue homogenates.<h4>Conclusion</h4>The results demonstrate that enhanced transport of L-Asp-ACV is as a result of corneal transporter involvement (probably amino acid transporter B(0,+)) and not as a result of changes in physicochemical properties due to prodrug derivatization (permeability of D-Asp-ACV and ACV were not significantly different).
O-GlcNAc-transferase (OGT) substrate specificity is regulated by transiently interacting proteins. To further examine the regulation of OGT, we have identified 27 putative OGT-interacting proteins through a yeast two-hybrid screen. Two of these proteins, Trak1 (OIP106) and O-GlcNAcase, have been shown previously to interact with and regulate OGT. We demonstrate here that MYPT1 and CARM1 also interact with and target OGT. MYPT1 and CARM1 are substrates of OGT in vitro and in vivo. MYPT1 and CARM1 also function to alter OGT substrate specificity in vitro. Furthermore depletion of MYPT1 in Neuro-2a neuroblastoma cells alters GlcNAcylation of several proteins under basal conditions, suggesting that MYPT1 regulates OGT substrate specificity in vivo.
Eph receptors have been implicated in regulating a diverse array of cellular functions in the developing nervous system. Recently, Eph receptors have been shown to promote cell death in adult germinal zones; however, their mechanisms of action remain ill-defined. In this study, we demonstrate that EphA4 is a new member of the dependence receptors family, which can initiate cell death in the absence of its ligand ephrinB3. Upon removal of its ligand, EphA4 triggers cell death that is dependent on caspase activation as caspase inhibitors prevent cell death. EphA4 itself is cleaved by caspase-3-like caspase in the intracellular domain at position D773/774, which is necessary for cell death initiation as mutation of the cleavage site abolishes apoptosis. In the adult subventricular zone, abolishing ephrinB3 results in increased cell death, while the absence of EphA4 results in excessive numbers of neuroblasts. Furthermore, infusion of soluble ephrinB3 into the lateral ventricle reduced cell death, and together these results support a dependence role for EphA4 in adult neurogenesis.
Also flagged:Oct-4gene expressiontranscription factorStellaphosphorylationmitochondrial
Journal Article2008-10-06✓ 1 SnippetZuccotti M, Merico V, Sacchi L, Bellone M, Brink TC, Bellazzi R, Stefanelli M, Redi CA, Garagna S, Adjaye J.
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…encoded by thePrdx6gene is a…
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<h4>Background</h4>The maternal contribution of transcripts and proteins supplied to the zygote is crucial for the progression from a gametic to an embryonic control of preimplantation development. Here we compared the transcriptional profiles of two types of mouse MII oocytes, one which is developmentally competent (MIISN oocyte), the other that ceases development at the 2-cell stage (MIINSN oocyte), with the aim of identifying genes and gene expression networks whose misregulated expression would contribute to a reduced developmental competence.<h4>Results</h4>We report that: 1) the transcription factor Oct-4 is absent in MIINSN oocytes, accounting for 2) the down-regulation of Stella, a maternal-effect factor required for the oocyte-to-embryo transition and of which Oct-4 is a positive regulator; 3) eighteen Oct-4-regulated genes are up-regulated in MIINSN oocytes and are part of gene expression networks implicated in the activation of adverse biochemical pathways such as oxidative phosphorylation, mitochondrial dysfunction and apoptosis.<h4>Conclusion</h4>The down-regulation of Oct-4 plays a crucial function in a sequence of molecular processes that leads to the developmental arrest of MIINSN oocytes. The use of a model study in which the MII oocyte ceases development consistently at the 2-cell stage has allowed to attribute a role to the maternal Oct-4 that has never been described before. Oct-4 emerges as a key regulator of the molecular events that govern the establishment of the developmental competence of mouse oocytes.
Also flagged:hydrocephalusHuntingtinpolyglutamineHuntington's diseaseHDneurodegenerative disorder
Journal Article2008-10-06✓ 5 SnippetsDietrich P, Shanmugasundaram R, Shuyu E, Dragatsis I.
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Abstract)
…Huntingtin is an essential protein in the mouse since inactivation of the mouse HD homolog (Hdh) gene results in early embryonic lethality.…
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…Congenital hydrocephalus associated with abnormal subcommissural organ in mice lacking huntingtin in Wnt1 cell lineages.…
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…Expansion of a polyglutamine stretch at the N-terminus of htt causes Huntington's disease (HD), a dominant neurodegenerative disorder.…
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…Our results show that hydrocephalus in mice lacking htt in Wnt1 cell lineages is associated with increase in CSF production by the choroid plexus, and abnormal subcommissural organ.…
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…Huntingtin (htt) is a 350…
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Huntingtin (htt) is a 350 kDa protein of unknown function, with no homologies with other known proteins. Expansion of a polyglutamine stretch at the N-terminus of htt causes Huntington's disease (HD), a dominant neurodegenerative disorder. Although it is generally accepted that HD is caused primarily by a gain-of-function mechanism, recent studies suggest that loss-of-function may also be part of HD pathogenesis. Huntingtin is an essential protein in the mouse since inactivation of the mouse HD homolog (Hdh) gene results in early embryonic lethality. Huntingtin is widely expressed in embryogenesis, and associated with a number of interacting proteins suggesting that htt may be involved in several processes including morphogenesis, neurogenesis and neuronal survival. To further investigate the role of htt in these processes, we have inactivated the Hdh gene in Wnt1 cell lineages using the Cre-loxP system of recombination. Here we show that conditional inactivation of the Hdh gene in Wnt1 cell lineages results in congenital hydrocephalus, implicating huntingtin for the first time in the regulation of cerebral spinal fluid (CSF) homeostasis. Our results show that hydrocephalus in mice lacking htt in Wnt1 cell lineages is associated with increase in CSF production by the choroid plexus, and abnormal subcommissural organ.
The histone H3 demethylase Ndy1/KDM2B protects cells from replicative senescence. Changes in the metabolism of reactive oxygen species (ROS) are important for establishing senescence, suggesting that Ndy1 may play a role in redox regulation. Here we show that Ndy1 protects from H(2)O(2)-induced apoptosis and G(2)/M arrest and inhibits ROS-mediated signaling and DNA damage, while knockdown of Ndy1 has the opposite effects. Consistent with these observations, whereas Ndy1 overexpression promotes H(2)O(2) detoxification, Ndy1 knockdown inhibits it. Ndy1 promotes the expression of genes encoding the antioxidant enzymes aminoadipic semialdehyde synthase (Aass), NAD(P)H quinone oxidoreductase-1 (Nqo1), peroxiredoxin-4 (Prdx4), and serine peptidase inhibitor b1b (Serpinb1b) and represses the expression of interleukin-19. At least two of these genes (Nqo1 and Prdx4) are regulated directly by Ndy1, which binds to specific sites within their promoters and demethylates promoter-associated histone H3 dimethylated at K36 and histone H3 trimethylated at K4. Simultaneous knockdown of Aass, Nqo1, Prdx4, and Serpinb1b in Ndy1-expressing cells to levels equivalent to those detected in control cells was sufficient to suppress the Ndy1 redox phenotype.
Also flagged:cohesinchromosomesRNA polymerase IIIbinding
Journal Article2008-10-06✓ 1 SnippetGartenberg MR, Merkenschlager M.
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Abstract)
…Condensinand cohesin are…
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Condensin and cohesin are loaded onto yeast chromosomes by a common mechanism at RNA polymerase III transcribed genes. Whereas cohesin translocates from these loading sites to mediate cohesion at secondary locations, condensin remains, bringing distant sites together into clusters.
Also flagged:cysteine proteasesthiophenolcysteine proteaseoxygenthiolcathepsin B
Journal Article2008-10-05No SnippetsTakeuchi Y, Fujiwara T, Shimone Y, Miyataka H, Satoh T, Kirk KL, Hori H.
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In order to investigate crystallographically the mechanism of inhibition of cysteine protease by alpha-methyl-gamma,gamma-diphenylallenecarboxylic acid ethyl ester 3, a cysteine protease inhibitor having in vivo stability, we synthesized N-(alpha-methyl-gamma,gamma-diphenylallenecarbonyl)-L-phenylalanine ethyl ester 4. Reaction of 4 with thiophenol, the SH group of which has similar pK(a) value to that of cysteine protease, produced oxygen-mediated radical adducts 6 and 7 in ambient air but did not proceed under oxygen-free conditions. Catalytic activities of two thiol enzymes including cathepsin B were also lowered in the absence of oxygen. These results suggest that cysteine protease can act through an oxygen-dependent radical mechanism.
Also flagged:Hepcidinpeptidehormoneironmetabolismcation
Journal Article2008-10-05✓ 2 SnippetsBansal SS, Halket JM, Bomford A, Simpson RJ, Simpson RJ, Vasavda N, Thein SL, Hider RC.
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Abstract)
…and suppressed inhemochromatosis, and they may…
Abstract)
…reduced levels inhemochromatosis(P<0.00006) and elevated…
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Hepcidin is a peptide hormone that functions as a key regulator of mammalian iron metabolism. Serum and urine levels are increased in inflammation and suppressed in hemochromatosis, and they may have diagnostic importance. This study describes the development and validation of an analytical method for the quantitative determination of the concentration of hepcidin in clinical samples. A stable, isotopically labeled internal standard, [15N,13C2]Gly12,20-hepcidin, was synthesized and a standard quantity was added to urine samples. Extraction was performed using weak cation exchange magnetic nanoparticles. An ion trap mass spectrometer was used to quantify hepcidin in the samples. The hepcidin assay was validated, and good recovery of hepcidin was obtained. The assay is accurate and precise. Urinary hepcidin levels of 3 to 9 nmol/mmol creatinine(-1) were found in healthy controls, with reduced levels in hemochromatosis (P<0.00006) and elevated levels in inflammation (P<0.00035). In sickle cell disease, a wide range was found, with the mean value not differing significantly from controls (P<0.26). In summary, a validated method has been developed for the quantitation of hepcidin using a stable, isotopically labeled internal standard and applied to determine the concentrations of hepcidin in the low nanomolar range in urine samples from patients and controls.
Also flagged:NPRClymphomasfollicular lymphomaschronic lymphocytic leukemiasresponse to environmentalgene expression
Journal Article2008-10-03✓ 4 SnippetsParodi S, Pistoia V, Muselli M.
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S I O 000080)
…VRK2 kinase). Comparison between class A (14 samples of NBC) and class B (20 heterogeneous lymphomas…
S I O 000080)
…VRK2 kinase). Comparison between class A (14 samples of NBC) and class B (20 heterogeneous lymphomas, including 9 FL and 11 CLL…
Results)
…n. 6 (VRK2 kinasekinase ) was…
Results)
…to clones ofVRK2 kinasekinase , genes…
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<h4>Unlabelled</h4>Most microarray experiments are carried out with the purpose of identifying genes whose expression varies in relation with specific conditions or in response to environmental stimuli. In such studies, genes showing similar mean expression values between two or more groups are considered as not differentially expressed, even if hidden subclasses with different expression values may exist. In this paper we propose a new method for identifying differentially expressed genes, based on the area between the ROC curve and the rising diagonal (ABCR). ABCR represents a more general approach than the standard area under the ROC curve (AUC), because it can identify both proper (i.e., concave) and not proper ROC curves (NPRC). In particular, NPRC may correspond to those genes that tend to escape standard selection methods.<h4>Results</h4>We assessed the performance of our method using data from a publicly available database of 4026 genes, including 14 normal B cell samples (NBC) and 20 heterogeneous lymphomas (namely: 9 follicular lymphomas and 11 chronic lymphocytic leukemias). Moreover, NBC also included two sub-classes, i.e., 6 heavily stimulated and 8 slightly or not stimulated samples. We identified 1607 differentially expressed genes with an estimated False Discovery Rate of 15%. Among them, 16 corresponded to NPRC and all escaped standard selection procedures based on AUC and t statistics. Moreover, a simple inspection to the shape of such plots allowed to identify the two subclasses in either one class in 13 cases (81%).<h4>Conclusion</h4>NPRC represent a new useful tool for the analysis of microarray data.
Also flagged:cancergene expressionBreast Cancerbreast cancersBRCA1BRCA2
Journal Article2008-10-03✓ 1 SnippetLiu Z, Gartenhaus RB, Tan M, Jiang F, Jiao X.
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…The over-expressedDCCgene in patients…
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<h4>Background</h4>Identifying genes and pathways associated with diseases such as cancer has been a subject of considerable research in recent years in the area of bioinformatics and computational biology. It has been demonstrated that the magnitude of differential expression does not necessarily indicate biological significance. Even a very small change in the expression of particular gene may have dramatic physiological consequences if the protein encoded by this gene plays a catalytic role in a specific cell function. Moreover, highly correlated genes may function together on the same pathway biologically. Finally, in sparse logistic regression with Lp (p < 1) penalty, the degree of the sparsity obtained is determined by the value of the regularization parameter. Usually this parameter must be carefully tuned through cross-validation, which is time consuming.<h4>Results</h4>In this paper, we proposed a simple Bayesian approach to integrate the regularization parameter out analytically using a new prior. Therefore, there is no longer a need for parameter selection, as it is eliminated entirely from the model. The proposed algorithm (BLpLog) is typically two or three orders of magnitude faster than the original algorithm and free from bias in performance estimation. We also define a novel similarity measure and develop an integrated algorithm to hunt the regulatory genes with low expression changes but having high correlation with the selected genes. Pathways of those correlated genes were identified with DAVID http://david.abcc.ncifcrf.gov/.<h4>Conclusion</h4>Experimental results with gene expression data demonstrate that the proposed methods can be utilized to identify important genes and pathways that are related to cancer and build a parsimonious model for future patient predictions.
…nodal metastases (vs. 48.0% DCC); and 47% had high-grade tumors…
Abstract)
…ductal cell adenocarcinoma (DCC) in order to…
Abstract)
…between ACC andDCCand to identify…
Abstract)
…(vs. 4.6 cmDCC); 32.1% had nodal…
Abstract)
…metastases (vs. 48.0%DCC); and 47% had…
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<h4>Introduction</h4>Pancreatic acinar cell carcinoma (ACC) is a rare tumor with poorly defined prognosis.<h4>Objective</h4>Our objective was to compare a large population of patients with ACC to pancreatic ductal cell adenocarcinoma (DCC) in order to determine distinguishing characteristics and to assess survival.<h4>Methods</h4>Patients were identified from the National Cancer Database. Regression methods were used to identify differences between ACC and DCC and to identify predictors of survival for resected ACC. Eight hundred sixty-five patients with ACC were identified.<h4>Results</h4>Median tumor size was 6.9 cm (vs. 4.6 cm DCC); 32.1% had nodal metastases (vs. 48.0% DCC); and 47% had high-grade tumors (vs. 37.3% DCC). Resection margins were R0 77.3%, R1 13.7%, and R2 9.0%. Patients with ACC were more likely to be male, white, and have larger tumor size, no nodal involvement, or pancreatic tail tumors. Stage-specific 5-year survival was significantly better for resected ACC vs. DCC Stage I: 52.4% vs. 28.4%, II: 40.2% vs. 9.8%, III: 22.8% vs. 6.8%, and IV: 17.2% vs. 2.8%. On multivariable analysis, age < 65, well-differentiated tumors, and negative resection margins were independent prognostic factors for ACC.<h4>Discussion</h4>ACC carries a better prognosis than DCC. Aggressive surgical resection with negative margins is associated with long-term survival in these more favorable pancreatic cancers.
Also flagged:ankle arthritisosteoarthritisOAsecondary arthritisprimary OAAnkle Osteoarthritis
Journal Article2008-10-02✓ 1 SnippetValderrabano V, Horisberger M, Russell I, Dougall H, Hintermann B.
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…hemochromatosis…
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<h4>Unlabelled</h4>The purpose of this study was to evaluate the distribution rate of etiologies leading to ankle arthritis and to quantify and compare the important clinical and radiologic variables among these etiologic groups. We evaluated data from 390 patients (406 ankles) who consulted our center because of painful end-stage ankle osteoarthritis (OA) by using medical history, physical examination, and radiography. Posttraumatic ankle OA was seen in 78% of the cases (n = 318), secondary arthritis in 13% (n = 52), and primary OA in 9% (n = 36). The average American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was 38 points (range, 0-74 points), range of motion was 22 degrees (range, 0 degrees-65 degrees), and visual analog scale for pain was 6.8 (range, 2-10). Patients with posttraumatic end-stage ankle OA were younger than patients with primary OA. The average tibiotalar alignment was 88 degrees (range, 51 degrees-116 degrees) and did not differ between the etiologic groups. Our study showed trauma is the main cause of ankle OA and primary OA is rare. In the majority of patients with ankle OA the average tibiotalar alignment is varus regardless of the underlying etiology.<h4>Level of evidence</h4>Level IV, prognostic study.
Also flagged:methylationBarrett's esophagusesophageal adenocarcinomaBEAPCCDKN2A
Journal Article2008-10-02✓ 1 SnippetSmith E, De Young NJ, Pavey SJ, Hayward NK, Nancarrow DJ, Whiteman DC, Smithers BM, Ruszkiewicz AR, Clouston AD, Gotley DC, Devitt PG, Jamieson GG, Drew PA.
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Discussion)
…(TP53), and 18q (DCC) are commonly lost,…
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<h4>Background</h4>Barrett's esophagus (BE) is the metaplastic replacement of squamous with columnar epithelium in the esophagus, as a result of reflux. It is the major risk factor for the development of esophageal adenocarcinoma (EAC). Methylation of CpG dinucleotides of normally unmethylated genes is associated with silencing of their expression, and is common in EAC. This study was designed to determine at what stage, in the progression from BE to EAC, methylation of key genes occurs.<h4>Results</h4>We examined nine genes (APC, CDKN2A, ID4, MGMT, RBP1, RUNX3, SFRP1, TIMP3, and TMEFF2), frequently methylated in multiple cancer types, in a panel of squamous (19 biopsies from patients without BE or EAC, 16 from patients with BE, 21 from patients with EAC), BE (40 metaplastic, seven high grade dysplastic) and 37 EAC tissues. The methylation frequency, the percentage of samples that had any extent of methylation, for each of the nine genes in the EAC (95%, 59%, 76%, 57%, 70%, 73%, 95%, 74% and 83% respectively) was significantly higher than in any of the squamous groups. The methylation frequency for each of the nine genes in the metaplastic BE (95%, 28%, 78%, 48%, 58%, 48%, 93%, 88% and 75% respectively) was significantly higher than in the squamous samples except for CDKN2A and RBP1. The methylation frequency did not differ between BE and EAC samples, except for CDKN2A and RUNX3 which were significantly higher in EAC. The methylation extent was an estimate of both the number of methylated alleles and the density of methylation on these alleles. This was significantly greater in EAC than in metaplastic BE for all genes except APC, MGMT and TIMP3. There was no significant difference in methylation extent for any gene between high grade dysplastic BE and EAC.<h4>Conclusion</h4>We found significant methylation in metaplastic BE, which for seven of the nine genes studied did not differ in frequency from that found in EAC. This is also the first report of gene silencing by methylation of ID4 in BE or EAC. This study suggests that metaplastic BE is a highly abnormal tissue, more similar to cancer tissue than to normal epithelium.
Also flagged:methylationMyelodysplastic syndromeshematologic disordersacute myeloid leukemiaAMLtumor-suppressor
Journal Article2008-10-02✓ 1 SnippetJiang Y, Dunbar A, Gondek LP, Mohan S, Rataul M, O'Keefe C, Sekeres M, Saunthararajah Y, Maciejewski JP.
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…DCC…
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Myelodysplastic syndromes (MDSs) are clonal hematologic disorders that frequently represent an intermediate disease stage before progression to acute myeloid leukemia (AML). As such, study of MDS/AML can provide insight into the mechanisms of neoplastic evolution. In 184 patients with MDS and AML, DNA methylation microarray and high-density single nucleotide polymorphism array (SNP-A) karyotyping were used to assess the relative contributions of aberrant DNA methylation and chromosomal deletions to tumor-suppressor gene (TSG) silencing during disease progression. Aberrant methylation was seen in every sample, on average affecting 91 of 1505 CpG loci in early MDS and 179 of 1505 loci after blast transformation (refractory anemia with excess blasts [RAEB]/AML). In contrast, chromosome aberrations were seen in 79% of early MDS samples and 90% of RAEB/AML samples, and were not as widely distributed over the genome. Analysis of the most frequently aberrantly methylated genes identified FZD9 as a candidate TSG on chromosome 7. In patients with chromosome deletion at the FZD9 locus, aberrant methylation of the remaining allele was associated with the poorest clinical outcome. These results indicate that aberrant methylation can cooperate with chromosome deletions to silence TSG. However, the ubiquity, extent, and correlation with disease progression suggest that aberrant DNA methylation is the dominant mechanism for TSG silencing and clonal variation in MDS evolution to AML.
Ferritin, a major iron storage protein, is essential to iron homeostasis and is involved in a wide range of physiologic and pathologic processes. In clinical medicine, ferritin is predominantly utilized as a serum marker of total body iron stores. In cases of iron deficiency and overload, serum ferritin serves a critical role in both diagnosis and management. Elevated serum and tissue ferritin are linked to coronary artery disease, malignancy, and poor outcomes following stem cell transplantation. Ferritin is directly implicated in less common but potentially devastating human diseases including sideroblastic anemias, neurodegenerative disorders, and hemophagocytic syndrome. Additionally, recent research describes novel functions of ferritin independent of iron storage.
…Substantial evidence supports a role for dysfunction of the serotonin transporter (5-HTT) in the pathogenesis of major depression.…
Abstract)
…the serotonin transporter (5-HTT) in the pathogenesis…
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Substantial evidence supports a role for dysfunction of the serotonin transporter (5-HTT) in the pathogenesis of major depression. The polymorphism of the serotonin transporter gene (5-HTTLPR) was found to be associated with reduced hippocampal volume in major depression. However, the original diallelic polymorphism was criticized, because the L-allele can be subtyped into La and Lg alleles, the latter of which is thought to be similar to the S-allele. Therefore, the study aim was to examine the influences of the triallelic (La-Lg-S system) and diallelic 5-HTTLPR on hippocampal volumes in patients with major depression and healthy controls. Using high-resolution MRI hippocampal volumes and polymorphisms (5-HTTLPR) were measured in 60 in-patients with major depression and 60 healthy controls. Patients with the La/La genotype had significantly smaller hippocampal gray and white matter than La/La controls. No significant differences were found between patients and controls with La/(Lg + S) or (Lg + S)/(Lg + S) genotype. Moreover, within the patient group the La/La homozygous genotype had significantly smaller hippocampal white matter volumes than the La/(Lg + S) or (Lg + S)/(Lg + S) genotype. In conclusion, with the diallelic as well as the triallelic system the homozygosity for the long-allele is associated with decreased hippocampal volumes in patients with major depression, but not in healthy controls, suggesting that disease or stress specific processes linked to the serotonergic system may enhance the vulnerability to morphological alterations.
Also flagged:bipolar disorderalcoholismpsychosissubstance abuseneurotransmissionGRIA1
Journal Article2008-10-01✓ 1 SnippetShi J, Badner JA, Hattori E, Potash JB, Willour VL, McMahon FJ, Gershon ES, Liu C.
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…5-HTT…
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Neurotransmission pathways/systems have been proposed to be involved in the pathophysiology and treatment of bipolar disorder for over 40 years. In order to test the hypothesis that common variants of genes in one or more of five neurotransmission systems confer risk for bipolar disorder, we analyzed 1,005 tag single nucleotide polymorphisms in 90 genes from dopaminergic, serotonergic, noradrenergic, GABAergic, and glutamatergic neurotransmitter systems in 101 trios and 203 quads from Caucasian bipolar families. Our sample has 80% power to detect ORs >or= 1.82 and >or=1.57 for minor allele frequencies of 0.1 and 0.5, respectively. Nominally significant allelic and haplotypic associations were found for genes from each neurotransmission system, with several reaching gene-wide significance (allelic: GRIA1, GRIN2D, and QDPR; haplotypic: GRIN2C, QDPR, and SLC6A3). However, none of these associations survived correction for multiple testing in an individual system, or in all systems considered together. Significant single nucleotide polymorphism associations were not found with sub-phenotypes (alcoholism, psychosis, substance abuse, and suicide attempts) or significant gene-gene interactions. These results suggest that, within the detectable odds ratios of this study, common variants of the selected genes in the five neurotransmission systems do not play major roles in influencing the risk for bipolar disorder or comorbid sub-phenotypes.
Also flagged:SoxTranscription factorsextracellularcell adhesion
Journal Article2008-10-01No SnippetsGuth SI, Wegner M.
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Transcription factors of the Sox family arose around the advent of multicellularity in animals, arguing that their ability to regulate the expression of extracellular matrix, cell adhesion and signaling molecules may have been instrumental in the generation of metazoans. In particular, during vertebrate evolution, the Sox family experienced a phase of expansion that led to the appearance of groups of highly homologous Sox proteins and the division of existing Sox protein functions among group members. It furthermore allowed Sox transcription factors to acquire numerous novel functions. These past events of subfunctionalization and neofunctionalization can still be recognized today in all groups of the Sox family. They have led to partial functional redundancies, but also to interesting species-specific variations in the developmental roles of Sox proteins as shown here for the SoxB and the SoxE groups.
Also flagged:Synthesis2-oxoamidessulfonamidecarboxylγ-amino acidsphospholipase A 2
Journal Article2008-10-01No SnippetsAntonopoulou G, Magrioti V, Stephens D, Constantinou-Kokotou V, Dennis EA, Kokotos G.
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A variety of lipophilic 2-oxoamides containing sulfonamide analogs of gamma-amino acids as well as acyl sulfonamides of gamma-aminobutyric acid were synthesized. Their ability to inhibit intracellular GIVA cPLA2 and GVIA iPLA2 as well as secreted GV sPLA2 was evaluated. The sulfonamide group seems a bioisosteric group suitable to replace the carboxyl group in 2-oxoamide inhibitors of GVIA cPLA2.
Also flagged:gene expressionRetembryogenesisneurointestinal diseasebone morphogenetic proteinmembrane
Journal Article2008-10-01No SnippetsGoldstein AM, Nagy N.
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The avian embryo has been an important model system for studying enteric nervous system (ENS) development for over 50 y. Since the initial demonstration in chick embryos that the ENS is derived from the neural crest, investigators have used the avian model to reveal the cellular origins and migratory pathways of enteric neural crest-derived cells, with more recent work focusing on the molecular mechanisms regulating ENS development. Seminal contributions have been made in this field by researchers who have taken advantage of the strengths of the avian model system. These strengths include in vivo accessibility throughout development, ability to generate quail-chick chimeras, and the capacity to modulate gene expression in vivo in a spatially and temporally targeted manner. The recent availability of the chicken genome further enhances this model system, allowing investigators to combine classic embryologic methods with current genetic techniques. The strengths and versatility of the avian embryo continue to make it a valuable experimental system for studying the development of the ENS.
Also flagged:head and neck squamous cell carcinomaHNSCCtumorhead and neck cancerscancerdeath
Journal Article2008-10-01No SnippetsChen Y, Chen C.
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Genetic aberrations, such as DNA copy number variation (CNV) and loss of heterozygosity (LOH), have been implicated in head and neck squamous cell carcinoma (HNSCC) initiation and progression. This review examines CNV and LOH as predictors of HNSCC recurrence and mortality. We searched PubMed for relevant publications and compared and discussed results from the articles. Certain CNV and LOH events have consistently been associated with HNSCC recurrence and survival. The recent high-resolution single nucleotide polymorphism (SNP) arrays have the potential to identify many more genetic changes and concurrent genome-wide CNV, copy-neutral and/or allelic imbalance LOH in HNSCC that may bear on prognosis. Our review confirms that outcome in HNSCC can be predicted to a considerable extent by the presence of tumor cell genetic aberrations. It points out the limitations of some methodologies that were used in the past and discusses the advantages and challenges of using genome-wide SNP arrays.
Also flagged:ERMgrowth conegrowth coneskinaseF-actinmembrane
Journal Article2008-10-01✓ 1 SnippetMintz CD, Carcea I, McNickle DG, Dickson TC, Ge Y, Salton SR, Benson DL.
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…DCC…
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Axonal growth cones initiate and sustain directed growth in response to cues in their environment. A variety of events such as receptor internalization, kinase activation, and actin rearrangement can be stimulated by guidance cues and are essential for mediating targeted growth cone behavior. Surprisingly little is known about how such disparate actions are coordinated. Our data suggest that ezrin, radixin, and moesin (ERMs), a family of highly homologous, multifunctional proteins may be able to coordinate growth cone responses to the guidance cue Semaphorin 3A (Sema3A). We show that active ERMs concentrate asymmetrically in neocortical growth cones, are rapidly and transiently inactivated by Sema3A, and are required for Sema3A-mediated growth cone collapse and guidance. The FERM domain of active ERMs regulates internalization of the Sema3A receptor, Npn1, and its coreceptor, L1CAM, while the ERM C-terminal domain binds and caps F-actin. Our data support a model in which ERMs can coordinate membrane and actin dynamics in response to Sema3A.
Also flagged:androgen receptorleutinizing hormone releasing hormoneLHRHprostate cancerARcancer
Journal Article2008-10-01No SnippetsSingh P, Hallur G, Anchoori RK, Bakare O, Kageyama Y, Khan SR, Isaacs JT.
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<h4>Background</h4>The standard hormonal therapy with currently available antiandrogens and the leutinizing hormone releasing hormone (LHRH) analogs is not effective in the hormone-refractory stage of prostate cancer due to changes in androgen receptor (AR) signaling axis. In this refractory stage, AR continues to play a significant role in the growth of cancer cells even though the cancer cells are no longer dependent on the level of circulating androgens.<h4>Methods</h4>A series of 11beta-Delta(9)-19 nortestosterone compounds were designed through structure-based rationale and tested for their binding affinity against AR and glucocorticoid receptor (GR) using fluorescence polarization assays, their agonistic ability to induce AR dependent transcription using PSA-driven report gene assays, and their growth inhibitory affects against a series of AR positive (LAPC4, LNCap, and CWR22R) and negative human prostate cancer cell lines (PC3) using MTT cell proliferation assays.<h4>Results</h4>This study proposes the design of novel bifunctional antiandrogens based on the conjugation of 11beta and/or 7alpha-Delta(9)-19 nortestosterone class of steroidal compounds to the synthetic ligand for FK506-binding proteins. As a critical step towards the development of bifunctional antiandrogens, highly potent and AR-specific lead compounds were identified using in vitro data. The lead compounds identified in this study possessed low binding affinity for GR, indicating the absence of undesirable antiglucocorticoid activity.<h4>Conclusions</h4>The results of this study validate our drug discovery rationale based on the structural biology of AR and pave the pay for future development of bifunctional compounds in order to block AR function in hormone refractory stage of prostate cancer.
Also flagged:multiple sclerosisMSinflammatory disease of theironmetabolismpathogenesis
Journal Article2008-10-01✓ 5 SnippetsRamagopalan SV, Cukjati M, Cernilec M, DeLuca GC, Dyment DA, Degenhardt A, Sadovnick AD, Serbec VC, Ebers GC, Duquette P.
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Abstract)
…The frequency of HFE mutations was not different in MS compared to the general population.…
Title)
…Mutations in the hemochromatosis gene and the clinical outcome of multiple sclerosis.…
Abstract)
…Given a possible role for dysregulation of iron metabolism in MS disease pathogenesis, we investigated whether or not mutations in the HFE gene influence the prognosis of the disease.…
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…Mutations in thehemochromatosisgene and the…
Abstract)
…mutations in theHFEgene influence the…
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Multiple sclerosis (MS) is a common inflammatory disease of the central nervous system unsurpassed for its variability in disease outcome. Given a possible role for dysregulation of iron metabolism in MS disease pathogenesis, we investigated whether or not mutations in the HFE gene influence the prognosis of the disease. A cohort of sporadic MS cases, taken from opposite extremes of the putative distribution of long-term outcome using the most stringent clinical criteria to date, was used to determine the role of HFE on MS disease severity. This approach increases the effective sample size by some 40-fold. Genotyping the two sets of MS patients (112 benign and 51 malignant) provided no evidence to suggest that mutations in HFE have any outcome modifying activity, although small effects cannot be ruled out. The frequency of HFE mutations was not different in MS compared to the general population.
Also flagged:synthesistetrahydropyranlasonolide Aalkoxyacetimideacetimideisoxazoline
Journal Article2008-10-01No SnippetsGhosh AK, Gong G.
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A detailed account of the enantioselective total synthesis of (-)-lasonolide A is described. Our initial synthetic route to the top tetrahydropyran ring involved Evans asymmetric alkylation as the key step. Initially, we relied on the diastereoselective alkylation of an alpha-alkoxyacetimide derivative containing an alpha' stereogenic center and investigated such an asymmetric alkylation reaction. Although alkylation proceeded in good yield, the lack of diastereoselectivity prompted us to explore alternative routes. Our subsequent successful synthetic strategies involved highly diastereoselective cycloaddition routes to both tetrahydropyran rings of lasonolide A. The top tetrahydropyran ring was constructed stereoselectively by an intramolecular 1,3-dipolar cycloaddition reaction. The overall process constructed a bicyclic isoxazoline, which was later unravelled to a functionalized tetrahydropyran ring as well as a quaternary stereocenter present in the molecule. The lower tetrahydropyran ring was assembled by a Jacobsen catalytic asymmetric hetero-Diels-Alder reaction as the key step. The synthesis also features a Lewis acid catalyzed epoxide opening to form a substituted ether stereoselectively.
Also flagged:NPcell differentiationß-cateninneurogenesisRAcell surface receptors
Journal Article2008-10-01No SnippetsDhara SK, Stice SL.
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Availability of human embryonic stem cells (hESC) has enhanced human neural differentiation research. The derivation of neural progenitor (NP) cells from hESC facilitates the interrogation of human embryonic development through the generation of neuronal subtypes and supporting glial cells. These cells will likely lead to novel drug screening and cell therapy uses. This review will discuss the current status of derivation, maintenance and further differentiation of NP cells with special emphasis on the cellular signaling involved in these processes. The derivation process affects the yield and homogeneity of the NP cells. Then when exposed to the correct environmental signaling cues, NP cells can follow a unique and robust temporal cell differentiation process forming numerous phenotypes.
Also flagged:UNC-5dendritesaxonaxonslocalizationsynaptic vesicle
Journal Article2008-10-01No SnippetsPoon VY, Klassen MP, Shen K.
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Polarity is an essential feature of many cell types, including neurons that receive information from local inputs within their dendrites and propagate nerve impulses to distant targets through a single axon. It is generally believed that intrinsic structural differences between axons and dendrites dictate the polarized localization of axonal and dendritic proteins. However, whether extracellular cues also instruct this process in vivo has not been explored. Here we show that the axon guidance cue UNC-6/netrin and its receptor UNC-5 act throughout development to exclude synaptic vesicle and active zone proteins from the dendrite of the Caenorhabditis elegans motor neuron DA9, which is proximal to a source of UNC-6/netrin. In unc-6/netrin and unc-5 loss-of-function mutants, presynaptic components mislocalize to the DA9 dendrite. In addition, ectopically expressed UNC-6/netrin, acting through UNC-5, is sufficient to exclude endogenous synapses from adjacent subcellular domains within the DA9 axon. Furthermore, this anti-synaptogenic activity is interchangeable with that of LIN-44/Wnt despite being transduced through different receptors, suggesting that extracellular cues such as netrin and Wnts not only guide axon navigation but also regulate the polarized accumulation of presynaptic components through local exclusion.
Also flagged:angiogeninRNaseamyotropic lateral sclerosisALSpathogenesisANG
Journal Article2008-10-01No SnippetsKishikawa H, Wu D, Hu GF.
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<h4>Background</h4>Missense heterozygous mutations in the coding region of angiogenin (ANG) gene, encoding a 14 kDa angiogenic RNase, were recently found in patients of amyotropic lateral sclerosis (ALS). Functional analyses have shown that these are loss-of-function mutations, implying that angiogenin deficiency is associated with ALS pathogenesis and that increasing ANG expression or angiogenin activity could be a novel approach for ALS therapy.<h4>Objective</h4>Review the evidence showing the involvement of angiogenin in motor neuron physiology and function, and provide a rationale for targeting angiogenin in ALS therapy.<h4>Methods</h4>Review the current understanding of the mechanism of angiogenin action in connection with ALS genetics, pathogenesis and therapy.<h4>Conclusion</h4>ANG is the first gene whose loss-of-function mutations are associated with ALS pathogenesis. Therapeutic modulation of angiogenin level and activity in the spinal cord, either by systemic delivery of angiogenin protein or through retrograde transport of ANG-encoding viral particles, may be beneficial for ALS patients.
Also flagged:Raf kinase inhibitory proteinRKIPphosphatidylethanolamine binding proteinPEBPsignal transductionMAPK
Journal Article2008-10-01No SnippetsZeng L, Imamoto A, Rosner MR.
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<h4>Background</h4>Raf kinase inhibitory protein (RKIP) belongs to the phosphatidylethanolamine binding protein (PEBP) family that is expressed in both prokaryotic and euakaryotic organisms.<h4>Objective</h4>In this review, we discuss the role of RKIP as a modulator of signal transduction, the relationship of RKIP to other members of the PEBP family, and the role of RKIP in human health and disease.<h4>Results/conclusion</h4>In mammals, RKIP regulates activation of MAPK, NF-kappaB and G protein coupled receptors (GPCRs). As a modulator of key signaling pathways, RKIP affects various cellular processes including cell differentiation, the cell cycle, apoptosis and cell migration. Emerging evidence suggests that RKIP is implicated in several human diseases or disorders, among them metastatic tumorigenesis and Alzheimer's disease.
Also flagged:brain malformationsACCchromosomedisorders of the corpus callosumoro-facial-digital syndrome type 1FOXG1B
Journal Article2008-10-01✓ 3 SnippetsSchell-Apacik CC, Wagner K, Bihler M, Ertl-Wagner B, Heinrich U, Klopocki E, Kalscheuer VM, Muenke M, von Voss H.
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Abstract)
…or partial absence ( dysgenesis of the corpus callosum-DCC ) were identified.…
Abstract)
…of the corpus callosum—DCC) were identified.…
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…DCC…
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Agenesis of the corpus callosum (ACC) is among the most frequent human brain malformations with an incidence of 0.5-70 in 10,000. It is a heterogeneous condition, for which several different genetic causes are known, for example, ACC as part of monogenic syndromes or complex chromosomal rearrangements. We systematically evaluated the data of 172 patients with documented corpus callosum abnormalities in the records, and 23 patients with chromosomal rearrangements known to be associated with corpus callosum changes. All available neuroimaging data, including CT and MRI, were re-evaluated following a standardized protocol. Whenever feasible chromosome and subtelomere analyses as well as molecular genetic testing were performed in patients with disorders of the corpus callosum in order to identify a genetic diagnosis. Our results showed that 41 patients with complete absence (agenesis of the corpus callosum-ACC) or partial absence (dysgenesis of the corpus callosum-DCC) were identified. Out of these 28 had ACC, 13 had DCC. In 11 of the 28 patients with ACC, the following diagnoses could be established: Mowat-Wilson syndrome (n = 2), Walker-Warburg syndrome (n = 1), oro-facial-digital syndrome type 1 (n = 1), and chromosomal rearrangements (n = 7), including a patient with an apparently balanced reciprocal translocation, which led to the disruption and a predicted loss of function in the FOXG1B gene. The cause of the ACC in 17 patients remained unclear. In 2 of the 13 patients with DCC, unbalanced chromosomal rearrangements could be detected (n = 2), while the cause of DCC in 11 patients remained unclear. In our series of cases a variety of genetic causes of disorders of the corpus callosum were identified with cytogenetic anomalies representing the most common underlying etiology.
Also flagged:Liver steatosisnonalcoholic fatty liver diseaseNAFLDwatersteatosisliver disease
Journal Article2008-10-01✓ 1 SnippetBahl M, Qayyum A, Westphalen AC, Noworolski SM, Chu PW, Ferrell L, Tien PC, Bass NM, Merriman RB.
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…hemochromatosis…
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<h4>Purpose</h4>To investigate if opposed-phase T1-weighted and fat-suppressed T2-weighted liver signal intensity (SI) loss and visceral fat measurement at magnetic resonance (MR) imaging and body mass index (BMI) are correlated with grade of liver steatosis in patients with nonalcoholic fatty liver disease (NAFLD) or hepatitis C virus (HCV) and human immunodeficiency virus (HIV)-related liver disease.<h4>Materials and methods</h4>Committee on Human Research approval and patient consent were obtained for this HIPAA-compliant study. Fifty-two patients (15 men, 37 women) with NAFLD (n = 29) or HCV and HIV-related liver disease (n = 23) underwent prospective contemporaneous MR imaging and liver biopsy. Liver SI loss was measured on opposed-phase T1-weighted and fat-suppressed T2-weighted MR images. Visceral fat area was measured at three levels on water-suppressed T1-weighted MR images (n = 44). Spearman rank correlation coefficients and recursive partitioning were used to examine correlations.<h4>Results</h4>Histopathologic liver steatosis correlated well with liver SI loss on opposed-phase T1-weighted MR images (rho = 0.78), fat-suppressed T2-weighted MR images (rho = 0.75), and average visceral fat area (rho = 0.77) (all P < .01) but poorly with BMI (rho = 0.53, P < .01). Liver SI losses on opposed-phase T1-weighted MR imaging of less than 3%, at least 3% but less than 35%, at least 35% but less than 49%, and at least 49% corresponded to histopathologic steatosis grades of 0 (n = 16 of 17), 1 (n = 11 of 16), 2 (n = 7 of 13), and 3 (n = 5 of 6), respectively. A visceral fat area of greater than or equal to 73.8 cm(2) was associated with the presence of histopathologic steatosis in 41 of 44 patients.<h4>Conclusion</h4>Liver SI loss on opposed-phase T1-weighted MR images and visceral fat area may be used as biomarkers for the presence of liver steatosis and appear to be superior to BMI.
<h4>Unlabelled</h4>The Roussel Uclaf Causality Assessment Method (RUCAM) was developed to quantify the strength of association between a liver injury and the medication implicated as causing the injury. However, its reliability in a research setting has never been fully explored. The aim of this study was to determine test-retest and interrater reliabilities of RUCAM in retrospectively-identified cases of drug induced liver injury. The Drug-Induced Liver Injury Network is enrolling well-defined cases of hepatotoxicity caused by isoniazid, phenytoin, clavulanate/amoxicillin, or valproate occurring since 1994. Each case was adjudicated by three reviewers working independently; after an interval of at least 5 months, cases were readjudicated by the same reviewers. A total of 40 drug-induced liver injury cases were enrolled including individuals treated with isoniazid (nine), phenytoin (five), clavulanate/amoxicillin (15), and valproate (11). Mean +/- standard deviation age at protocol-defined onset was 44.8 +/- 19.5 years; patients were 68% female and 78% Caucasian. Cases were classified as hepatocellular (44%), mixed (28%), or cholestatic (28%). Test-retest differences ranged from -7 to +8 with complete agreement in only 26% of cases. On average, the maximum absolute difference among the three reviewers was 3.1 on the first adjudication and 2.7 on the second, although much of this variability could be attributed to differences between the enrolling investigator and the external reviewers. The test-retest reliability by the same assessors was 0.54 (upper 95% confidence limit = 0.77); the interrater reliability was 0.45 (upper 95% confidence limit = 0.58). Categorizing the RUCAM to a five-category scale improved these reliabilities but only marginally.<h4>Conclusion</h4>The mediocre reliability of the RUCAM is problematic for future studies of drug-induced liver injury. Alternative methods, including modifying the RUCAM, developing drug-specific instruments, or causality assessment based on expert opinion, may be more appropriate.
Also flagged:metabolismporphyrinsrespiratory chainextracellularsuperoxidelocalization
Journal Article2008-10-01✓ 1 SnippetAllen TD, Moore DR, Wang X, Casu V, May R, Lerner MR, Houchen C, Brackett DJ, Huycke MM.
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…DCC…
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Enterococcus faecalis is an intestinal commensal that cannot synthesize porphyrins and only expresses a functional respiratory chain when provided with exogenous haematin. In the absence of haematin, E. faecalis reverts to fermentative metabolism and produces extracellular superoxide that can damage epithelial-cell DNA. The acute response of the colonic mucosa to haematin-starved E. faecalis was identified by gene array. E. faecalis was inoculated into murine colons using a surgical ligation model that preserved tissue architecture and homeostasis. The mucosa was exposed to haematin-starved E. faecalis and compared with a control consisting of the same strain grown with haematin. At 1 h post-inoculation, 6 mucosal genes were differentially regulated and this increased to 42 genes at 6 h. At 6 h, a highly significant biological interaction network was identified with functions that included nuclear factor-kappaB (NF-kappaB) signalling, apoptosis and cell-cycle regulation. Colon biopsies showed no histological abnormalities by haematoxylin and eosin staining. Immunohistochemical staining, however, detected NF-kappaB activation in tissue macrophages using antibodies to the nuclear localization sequence for p65 and the F4/80 marker for murine macrophages. Similarly, haematin-starved E. faecalis strongly activated NF-kappaB in murine macrophages in vitro. Furthermore, primary and transformed colonic epithelial cells activated the G2/M checkpoint in vitro following exposure to haematin-starved E. faecalis. Modulation of this cell-cycle checkpoint was due to extracellular superoxide produced as a result of the respiratory block in haematin-starved E. faecalis. These results demonstrate that the uniquely dichotomous metabolism of E. faecalis can significantly modulate gene expression in the colonic mucosa for pathways associated with inflammation, apoptosis and cell-cycle regulation.
Also flagged:oxygencarbohydratecatabolismOCT4SOX2NANOG
Journal Article2008-10-01No SnippetsWestfall SD, Sachdev S, Das P, Hearne LB, Hannink M, Roberts RM, Ezashi T.
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To realize the full potential of human embryonic stem cells (hESCs), it is important to develop culture conditions that maintain hESCs in a pluripotent, undifferentiated state. A low O(2) atmosphere (approximately 4% O(2)), for example, prevents spontaneous differentiation and supports self-renewal of hESCs. To identify genes whose expression is sensitive to O(2) conditions, microarray analysis was performed on RNA from hESCs that had been maintained under either 4% or 20% O(2). Of 149 genes differentially expressed, 42 were up-regulated and 107 down-regulated under 20% O(2). Several of the down-regulated genes are most likely under the control of hypoxia-inducing factors and include genes encoding enzymes involved in carbohydrate catabolism and cellular redox state. Although genes associated with pluripotency, including OCT4, SOX2, and NANOG were generally unaffected, some genes controlled by these transcription factors, including LEFTY2, showed lowered expression under 20% O(2), while a few genes implicated in lineage specification were up-regulated. Although the differences between O(2) conditions were generally subtle, they were observed in two different hESC lines and at different passage numbers. The data are consistent with the hypothesis that 4% O(2) favors the molecular mechanisms required for the maintenance of pluripotency.
Activating signals generated by members of the tumour necrosis factor receptor superfamily upon interaction with their cognate ligands play important roles in T-cell responses. Members of the tumour necrosis factor family namely 4-1BBL, OX40L, CD70, GITRL, LIGHT and CD30L have been described to function as costimulatory molecules by binding such receptors on T cells. Using our recently described system of T-cell stimulator cells we have performed the first study where all these molecules have been assessed and compared regarding their capacity to costimulate proliferation and cytokine production of human T cells. 4-1BBL, which we found to be the most potent molecule in this group, was able to mediate sustained activation and proliferation of human T cells. OX40L and CD70 were also strong inducers of T-cell proliferation, whereas the costimulatory capacity of human GITRL was significantly lower. Importantly CD30L and LIGHT consistently failed to act costimulatory on human T cells, and we therefore suggest that these molecules might be functionally distinct from the costimulatory members of this family.
Also flagged:Serotonin transportermonoamine oxidaseMAOAalcoholismserotoninpsychic illness
Journal Article2008-10-01✓ 5 SnippetsGokturk C, Schultze S, Nilsson KW, von Knorring L, Oreland L, Hallman J.
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Abstract)
…A significantly higher frequency of the LL 5-HTT genotype (high activity) was found in female addicts without a known co-morbid psychiatric disorder than in the controls.…
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…Genotyping of two functional polymorphisms in the promoter region of the serotonin transporter and monoamine oxidase-A, respectively, (5-HTT-LPR and MAOA-VNTR), was performed in a group of women with severe alcohol addiction.…
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…The pattern of associations between genotypes of 5-HTT-LPR and MAOA-VNTR in women with severe alcoholism differs from most corresponding studies on males.…
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…ine oxidase-A, respectively, (5-HTT-LPR and MAOA-VNTR), was…
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…of the LL5-HTTgenotype (high activity)…
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The serotonin system is known to play a pivotal role for mood, behaviour and psychic illness as e.g. alcoholism. Alcoholism in both males and females has been associated with polymorphisms in genes encoding for proteins of importance for central serotonergic function. Genotyping of two functional polymorphisms in the promoter region of the serotonin transporter and monoamine oxidase-A, respectively, (5-HTT-LPR and MAOA-VNTR), was performed in a group of women with severe alcohol addiction. A large sample of adolescent females from a normal population was used as controls. A significantly higher frequency of the LL 5-HTT genotype (high activity) was found in female addicts without a known co-morbid psychiatric disorder than in the controls. Genotype of the MAOA-VNTR polymorphism did not differ significantly between addicts and controls. However, within the group of alcoholics, when the patients with known co-morbid psychiatric disorders were excluded, aggressive anti-social behaviour was significantly linked to the presence of the high activity MAOA allele. The pattern of associations between genotypes of 5-HTT-LPR and MAOA-VNTR in women with severe alcoholism differs from most corresponding studies on males.
Also flagged:PAX2transcription factorssec31otic vesiclebrain 2POU domain , class 3 , transcription factor 2
Journal Article2008-10-01✓ 2 SnippetsRamialison M, Bajoghli B, Bajoghli B, Aghaallaei N, Ettwiller L, Gaudan S, Wittbrodt B, Czerny T, Wittbrodt J.
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Introduction)
…( brn2 (pou3f2), claudin-7 ,…
Results)
…( brn2 /pou3f2) (Figure 3b…
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<h4>Background</h4>The pax2/5/8 genes belonging to the PAX family of transcription factors are key developmental regulators that are involved in the patterning of various embryonic tissues. More particularly, their function in inner ear specification has been widely described. However, little is known about the direct downstream targets and, so far, no global approaches have been performed to identify these target genes in this particular tissue.<h4>Results</h4>Here we present an original bioinformatics pipeline composed of comparative genomics, database querying and text mining tools, which is designed to rapidly and specifically discover PAX2/5/8 direct downstream targets involved in inner ear development. We provide evidence supported by experimental validation in medaka fish that brain 2 (POU domain, class 3, transcription factor 2), claudin-7, secretory pathway component sec31-like and meteorin-like precursor are novel direct downstream targets of PAX2/5/8.<h4>Conclusions</h4>This study illustrates the power of extensive mining of public data repositories using bioinformatics methods to provide answers for a specific biological question. It furthermore demonstrates how the usage of such a combinatorial approach is advantageous for the biologist in terms of experimentation time and costs.
…Brn-2 represses microphthalmia-associated transcription factor expression and marks a distinct subpopulation of microphthalmia-associated transcription factor-negative melanoma cells.…
Abstract)
…The Brn-2 (N-Oct-3, POU3F2) transcription factor also regulates melanoma proliferation and is up-regulated by BRAF and beta-catenin, two key melanoma-associated signaling molecules.…
The origin of tumor heterogeneity is poorly understood, yet it represents a major barrier to effective therapy. In melanoma and in melanocyte development, the microphthalmia-associated transcription factor (Mitf) controls survival, differentiation, proliferation, and migration/metastasis. The Brn-2 (N-Oct-3, POU3F2) transcription factor also regulates melanoma proliferation and is up-regulated by BRAF and beta-catenin, two key melanoma-associated signaling molecules. Here, we show that Brn-2 also regulates invasiveness and directly represses Mitf expression. Remarkably, in melanoma biopsies, Mitf and Brn-2 each mark a distinct subpopulation of melanoma cells, providing a striking illustration of melanoma tumor heterogeneity with implications for melanoma therapy.
Also flagged:Imidazoquinolinethymic stromal lymphopoietinAtopic dermatitisallergic diseasesteroidsTSLP
Journal Article2008-10-01No SnippetsTorii Y, Ito T, Amakawa R, Sugimoto H, Amuro H, Tanijiri T, Katashiba Y, Ogata M, Yokoi T, Fukuhara S.
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Atopic dermatitis is a major allergic disease that develops through dysregulation of Th2-mediated inflammation. Although dendritic cells (DCs) have been thought to play a critical role in the upstream phase of the allergic cascade, conventional drugs such as steroids and chemical mediator antagonists target the effector cells or factors in allergic inflammation. Recently, it has been demonstrated that interaction between thymic stromal lymphopoietin (TSLP) and human DCs plays an essential role in evoking inflammatory Th2 responses in allergy through OX40 ligand expression on DCs. In this study, we provide evidence that R848, an imidazoquinoline compound, which is a TLR ligand and a strong Th1 response-inducing reagent, is a potent adjuvant for the alteration of the Th2-inducing potency of human DCs activated by TSLP (TSLP-DCs). R848 inhibited the inflammatory Th2-inducing capacity of TSLP-DCs and redirected them to possessing an IL-10 and IFN-gamma-producing regulatory Th1-inducing capacity. This functional alteration depended on both repression of OX40 ligand expression and induction of IL-12 production from DCs by the addition of R848. Additionally, R848 had the ability to inhibit the TSLP-mediated expansion and maintenance of the Th2 memory response. These findings suggest that imidazoquinoline may be a useful in the treatment of allergic diseases that are triggered by TSLP.
The effects of atrial polypeptide and neurohormone C upon the interaction of human factor Xa (FXa) and human antithrombin III (ATIII) were followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. A pattern of bands consisting of a 1 degree duplex complex (FXaalpha-ATIII band of 109 kDa, FXabeta-ATIII band of 104 kDa), a 2 degree duplex complex (alpha band of 99 kDa, beta band of 95 kDa), a 3 degree duplex complex (alpha band of 66 kDa, beta band of 62 kDa), modified ATIII (ATIIIM, 58 kDa), native ATIII (55 kDa), FXaalpha (52 kDa), FXabeta (47 kDa), and a FXa degradation product (FXagamma, 35 kDa) was detected and quantitated. Preincubation of FXa, ATIII, or mixtures thereof with atrial polypeptide produced a shift from FXaalpha-ATIII to FXabeta-ATIII complexes and increases in both ATIIIM and FXagamma, reflecting degradation of the 1 degree and 2 degree complex to form the 3 degree complex. Atrial polypeptide appeared to promote FXa-ATIII complex formation when preincubated with ATIII, or when added within 1 min to FXa/ATIII mixtures. However, when atrial polypeptide was preincubated with FXa, inhibition of the 1 degree complex formation was suggested. Upon incubation of FXa, ATIII, or mixtures thereof with neurohormone C, there was an increase in total complex formation, a decrease in ATIIIM, a decrease in FXagamma, and little change in the ratio of free FXaalpha to FXabeta, or the ratio of FXaalpha-ATIII to FXabeta-ATIII complexes. Therefore, neurohormone C may act to suppress hydrolysis or proteolytic actions of excess FXa on FXa-ATIII complexes, or autolytic activity of FXa, to the level of FXagamma via an, as yet, unknown mechanism. Additionally, neurohormone C retards the hydrolysis of the FXa-ATIII complexes which form free FXa and ATIIIM. Hence, the role of atrial polypeptide in mixtures with ATIII and in mixtures with FXa is quite contrasting, and may reflect mechanistic effects of the atrial polypeptide molecule, as well as tissue-specific reactions.
Also flagged:nuclear envelopeautosomal dominant neurodegenerative disorderPolyglutamineinclusion bodiesenvelopelamin B1
Journal Article2008-10-01No SnippetsChapple JP, Bros-Facer V, Butler R, Gallo JM.
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Huntington's disease is an autosomal dominant neurodegenerative disorder caused by the expansion of a polyglutamine repeat tract in the huntingtin protein. Polyglutamine-expanded huntingtin forms intranuclear as well as perinuclear inclusion bodies. Perinuclear aggregates formed by polyglutamine-expanded proteins are associated with a characteristic indentation of the nuclear envelope. We examined the nuclear envelope in cells containing huntingtin aggregates using immunostaining for lamin B1, a major component of the nuclear lamina. Laser confocal microscopy analysis revealed that huntingtin aggregates in a juxtanuclear position were associated with a clear focal distortion in the nuclear envelope in cells transfected with polyglutamine-expanded huntingtin. Lamin B1 distribution was not altered by aggregates of polyglutamine-expanded ataxin-1, that are exclusively intranuclear. Thus lamin immunocytochemistry demonstrates clearly the depression of the nuclear envelope resulting from the formation of perinuclear aggregates by polyglutamine-expanded huntingtin. Lamin immunocytochemistry would be of value to monitor the state of the nuclear envelope in experimental paradigms aimed at establishing the significance of perinuclear aggregates of pathogenic proteins.
Also flagged:Netrin-1axonsnetrin receptorUnc5caxonal growthsemaphorin 3A
Journal Article2008-10-01✓ 1 SnippetMasuda T, Watanabe K, Sakuma C, Ikenaka K, Ono K, Yaginuma H.
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During early development, the ventral spinal cord expresses chemorepulsive signals that act on dorsal root ganglion (DRG) axons to help orient them toward the dorsolateral part of the spinal cord. However, the molecular nature of this chemorepulsion is mostly unknown. We report here that netrin-1 acts as an early ventral spinal cord-derived chemorepellent for DRG axons. In the developing mouse spinal cord, netrin-1 is expressed in the floor plate of the spinal cord, and the netrin receptor Unc5c is expressed in DRG neurons. We show that human embryonic kidney cell aggregates secreting netrin-1 repel DRG axons and that netrin-1-deficient ventral spinal cord explants lose their repulsive influence on DRG axons. In embryonic day 10 netrin-1 mutant mice, we find that DRG axons exhibit transient misorientation. Furthermore, by means of gain-of-function analyses, we show that ectopic netrin-1 in the dorsal and intermediate spinal cord prevents DRG axons from being directed toward the dorsal spinal cord. Together, these findings suggest that netrin-1 contributes to the formation of the initial trajectories of developing DRG axons as a repulsive guidance cue.
<h4>Purpose</h4>The aims of our study were to elucidate the role of methylation of a large panel of genes during multistage pathogenesis of bladder cancer and to correlate our findings with patient age and other clinicopathologic features.<h4>Experimental design</h4>We studied the methylation status of 21 genes by quantitative methylation-specific PCR in an evaluation set of 25 tumor and 5 normal samples. Based on methylation frequency in tumors and normals in gene evaluation set, we selected 7 candidate genes and tested an independent set of 93 tumors and 26 normals. The presence or absence of methylation was evaluated for an association with cancer using cross-tabulations and chi(2) or Fisher's exact tests as appropriate. All statistical tests were two-sided.<h4>Results</h4>Most primary tumors (89 of 93, 96%) had methylation of one or more genes of independent set; 53 (57%) CCNA1, 29 (31%) MINT1, 36 (39%) CRBP, 53 (57%) CCND2, 66 (71%) PGP9.5, 60 (65%) CALCA, and 78 (84%) AIM1. Normal uroepithelium samples from 26 controls revealed no methylation of the CCNA1 and MINT1 genes, whereas methylation of CRBP, CCND2, PGP9.5, and CALCA was detected at low levels. All the 7 genes in independent set were tightly correlated with each other and 3 of these genes showed increased methylation frequencies in bladder cancer with increasing age. PGP9.5 and AIM1 methylation correlated with primary tumor invasion.<h4>Conclusion</h4>Our results indicate that the methylation profile of novel genes in bladder cancers correlates with clinicopathologic features of poor prognosis and is an age-related phenomenon.
Also flagged:OX40systemic sclerosisCD134tumor necrosis factor receptorsystemic lupus erythematosusSLE
Journal Article2008-10-01No SnippetsKomura K, Yoshizaki A, Kodera M, Iwata Y, Ogawa F, Shimizu K, Wayaku T, Yukami T, Murata M, Hasegawa M, Fujimoto M, Takehara K, Sato S.
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<h4>Objective</h4>To determine levels of serum soluble OX40 (also termed CD134, a member of the tumor necrosis factor receptor superfamily) and their clinical associations in patients with systemic sclerosis (SSc).<h4>Methods</h4>Serum soluble OX40 levels were examined by ELISA in 53 patients with SSc, 15 patients with systemic lupus erythematosus (SLE), and 32 healthy individuals.<h4>Results</h4>OX40 levels were significantly elevated in SSc patients (125.7 +/- 5.7 pg/ml) compared to patients with SLE (80.7 +/- 1.7 pg/ml; p < 0.005) and controls (88.2 +/- 3.0 pg/ml; p < 0.0001). Elevated OX40 levels were found to be associated with disease duration of less than 2 years (p < 0.05).<h4>Conclusion</h4>Our results suggest that serum soluble OX40 levels correlate with the early-onset of SSc disease.
Management of acute and chronic pain has always been a key area of clinical research. Enkephalinase inhibitors (EIs) seem to be promising as therapeutic agents having antinociceptive action. They additionally possess anticraving, antidiarrhoeal and antidepressant actions. The antinociceptive action of EIs has been reported for over a decade however, their therapeutic potential is yet to be effectively explored. EIs may be broadly classified as endogenous and those that are obtained synthetically. Endogenous EIs include peptides like spinorphin and opiorphin. And compounds like RB 101, RB 120, RB 3007 constitute the synthetically obtained EIs. Endogenous and synthetic inhibitors enkephalin degrading enzymes have been studied in vivo using standard animal models. The potential EI targets appear to be APN (Aminopeptidase N), NEP (Neutral endopeptidase), DPP-III (Dipeptidyl peptidase). EIs possess the advantage that they lack the opioid side effects. This article reviews the mechanisms by which EIs act and elucidates the pathways involved.
There is a strong association between porphyria cutanea tarda (PCT) and chronic viral hepatitis C. Therapy for chronic viral hepatitis C may improve PCT. However, there are only a few reports of the de novo development of PCT during therapy for chronic viral hepatitis C. We describe the development of PCT in a 56-year-old patient with chronic viral hepatitis C after 12 wk of peginterferon/ribavirin therapy. In addition, the patient was homozygous for the H63D hereditary hemochromatosis gene (HFE) mutation. The association of PCT with chronic viral hepatitis C and the possible role of hepatic iron overload and ribavirin-induced hemolytic anemia in the development of PCT during therapy for chronic viral hepatitis C are discussed.
Also flagged:Netrin-1cervical tumortumorsuppressorin colon canceraxon
Journal Article2008-10-01✓ 5 SnippetsRoperch JP, El Ouadrani K, Hendrix A, Emami S, De Wever O, Melino G, Gespach C.
In-Text Gene Mentions
Abstract)
…Collectively, our data reveal that the transcriptionally active TAp73alpha tumor suppressor is implicated in the apoptosis induced by netrin-1 in a p53-independent and DCC/ubiquitin-proteasome dependent manner.…
Abstract)
…Netrins and their receptors deleted in colon cancer (DCC), neogenin, UNC5, and integrins are involved in axon guidance, epithelial morphogenesis, vascular pattering, cancer cell survival, invasion, tumor angiogenesis, and metastasis.…
Netrins and their receptors deleted in colon cancer (DCC), neogenin, UNC5, and integrins are involved in axon guidance, epithelial morphogenesis, vascular pattering, cancer cell survival, invasion, tumor angiogenesis, and metastasis. Here, we considered the possible contribution of the p53-related apoptosis mediators p63 and p73 in the mechanisms underlying the antagonism between netrin-1 and DCC at the cell death control. We have showed that ectopic expression and external addition of netrin-1 in HeLa and HEK-293 cells with inactive p53 lead to impaired cell viability and induction of apoptosis. These responses were associated with up-regulation of the proapoptotic protein TAp73alpha, decreased Bcl-2/Bax ratio, and caspase-3 cleavage, with no change in protein levels of the antiapoptotic NH(2)-terminal-truncated DeltaNp73alpha isoform, p73 adapter Yap-1 and p73 E3 ubiquitin ligase Itch, and p63, as well as the transcripts encoding p63, TAp73alpha, and DeltaNp73alpha. However, the proteasome inhibitor MG132 potentiated, while DCC counteracted, netrin-1-induced TAp73alpha. Consistently, netrin-1 expression correlated with stabilization of the TAp73alpha protein and lower levels of TAp73alpha ubiquitination that was conversely enhanced by DCC, in a netrin-dependent manner. Our data indicate that netrin-1 selectively up-regulates TAp73alpha by preventing its ubiquitination and degradation. Targeted repression of p73alpha by shRNA reversed TAp73alpha and the apoptosis induced by netrin-1, and exacerbated the growth of HeLa tumor xenografts. Apoptosis induced by cisplatin was markedly enhanced in netrin-1 or DCC-expressing cells. Collectively, our data reveal that the transcriptionally active TAp73alpha tumor suppressor is implicated in the apoptosis induced by netrin-1 in a p53-independent and DCC/ubiquitin-proteasome dependent manner.
Also flagged:HuntingtinpolyglutamineHuntington's diseaseneurodegenerative disorderbindingtranscription factors
Journal Article2008-10-01✓ 5 SnippetsBenn CL, Sun T, Sadri-Vakili G, McFarland KN, DiRocco DP, Yohrling GJ, Clark TW, Bouzou B, Cha JH.
In-Text Gene Mentions
Abstract)
…Transcriptional dysregulation is a central pathogenic mechanism in Huntington's disease, a fatal neurodegenerative disorder associated with polyglutamine (polyQ) expansion in the huntingtin (Htt) protein.…
Abstract)
…in the huntingtin (Htt) protein.…
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…show that mutantHttalters the normal…
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…cipitation (ChIP) demonstratesHttoccupation of gene…
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…wild-type and mutantHttexhibit differential genomic…
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Transcriptional dysregulation is a central pathogenic mechanism in Huntington's disease, a fatal neurodegenerative disorder associated with polyglutamine (polyQ) expansion in the huntingtin (Htt) protein. In this study, we show that mutant Htt alters the normal expression of specific mRNA species at least partly by disrupting the binding activities of many transcription factors which govern the expression of the dysregulated mRNA species. Chromatin immunoprecipitation (ChIP) demonstrates Htt occupation of gene promoters in vivo in a polyQ-dependent manner, and furthermore, ChIP-on-chip and ChIP subcloning reveal that wild-type and mutant Htt exhibit differential genomic distributions. Exon 1 Htt binds DNA directly in the absence of other proteins and alters DNA conformation. PolyQ expansion increases Htt-DNA interactions, with binding to recognition elements of transcription factors whose function is altered in HD. Together, these findings suggest mutant Htt modulates gene expression through abnormal interactions with genomic DNA, altering DNA conformation and transcription factor binding.
The intrinsic electrical properties and the synaptic input-output relationships of neurons are governed by the action of voltage-dependent ion channels. The localization of specific populations of ion channels with distinct functional properties at discrete sites in neurons dramatically impacts excitability and synaptic transmission. Molecular cloning studies have revealed a large family of genes encoding voltage-dependent ion channel principal and auxiliary subunits, most of which are expressed in mammalian central neurons. Much recent effort has focused on determining which of these subunits coassemble into native neuronal channel complexes, and the cellular and subcellular distributions of these complexes, as a crucial step in understanding the contribution of these channels to specific aspects of neuronal function. Here we review progress made on recent studies aimed to determine the cellular and subcellular distribution of specific ion channel subunits in mammalian brain neurons using in situ hybridization and immunohistochemistry. We also discuss the repertoire of ion channel subunits in specific neuronal compartments and implications for neuronal physiology. Finally, we discuss the emerging mechanisms for determining the discrete subcellular distributions observed for many neuronal ion channels.
<h4>Background</h4>Hepcidin is a circulating hepatic hormone that regulates iron balance. It has been speculated that hepcidin insufficiency or dysregulation may be the primary defect in genetic hemochromatosis.<h4>Methods</h4>A 62-year-old woman underwent elective liver transplantation for chronic hepatitis C cirrhosis. Genetic testing for hemochromatosis was subsequently performed on the donor and recipient. Liver iron concentration was measured in the donated liver at the time of transplantation, and at day 2 and day 652 post-transplant. Serum hepcidin was measured at day 935 in the recipient and in three other liver transplant recipients.<h4>Results</h4>The donor was discovered to have significant iron overload without fibrosis, with a liver iron concentration of 326 micromol/g (normal is 0 micromol/g to 35 micromol/g). Genetic testing confirmed that the 89-year-old female donor was a typical C282Y homozygote for hemochromatosis. The recipient did not carry either the C282Y or the H63D mutation of the HFE gene for hemochromatosis. Liver biopsy was performed on the recipient on day 2 and day 652 post-transplant; the liver iron concentrations were 333 micromol/g and 253 micromol/g, respectively. Serum hepcidin in the recipient was elevated at 111 ng/mL compared with that of the three other ambulatory liver transplant recipients (66 ng/mL, 76 ng/mL and 81 ng/mL).<h4>Conclusion</h4>The liver transplant recipient described in the present report demonstrated a slight decrease in liver iron concentration over a 1.8-year follow-up period without specific therapy. Hepcidin insufficiency as a primary cause of genetic hemochromatosis seems unlikely based on the clinical profile of the present patient and the hepcidin measurements.
Also flagged:membranespremature rupture of the membraneschronic hypertensionpreeclampsiavitamin CPPROM
Journal Article2008-10-01No SnippetsSpinnato JA, Freire S, Pinto e Silva JL, Rudge MV, Martins-Costa S, Koch MA, Goco N, Santos Cde B, Cecatti JG, Costa R, Ramos JG, Moss N, Sibai BM.
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<h4>Objective</h4>The purpose of this study was to determine if antioxidant supplementation during pregnancy reduces the incidence of premature rupture of the membranes (PROM).<h4>Study design</h4>A placebo-controlled, double-blind trial was conducted. PROM and preterm PROM (PPROM) were planned secondary outcomes of the trial. Women between 12(0/7) and 19(6/7) weeks of gestation and diagnosed to have chronic hypertension or a prior history of preeclampsia were randomized to daily treatment with both vitamin C (1000 mg) and E (400 IU) or placebo.<h4>Results</h4>Outcome data for PROM were available for 697 of 739 patients. The rates of PROM (37/349 [10.6%] vs 19/348 [5.5%]; adjusted risk ratio [RR] 1.89 [95.42% CI, 1.11-3.23]; P = .015), and PPROM (16/349 [4.6%] vs 6/348 [1.7%]; RR 2.68 [1.07-6.71]; P = .025) were increased in the antioxidant group.<h4>Conclusion</h4>Contrary to expectations, vitamins C and E supplementation in this dose combination may be associated with an increased risk of PROM and PPROM.
Also flagged:liver diseasesCPN1SAMM50chromosomegamma-glutamyl transferasealkaline phosphatase
Journal Article2008-10-01No SnippetsYuan X, Waterworth D, Perry JR, Lim N, Song K, Chambers JC, Zhang W, Vollenweider P, Stirnadel H, Johnson T, Bergmann S, Beckmann ND, Li Y, Ferrucci L, Melzer D, Hernandez D, Singleton A, Scott J, Elliott P, Waeber G, Cardon L, Frayling TM, Kooner JS, Mooser V.
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Plasma liver-enzyme tests are widely used in the clinic for the diagnosis of liver diseases and for monitoring the response to drug treatment. There is considerable evidence that human genetic variation influences plasma levels of liver enzymes. However, such genetic variation has not been systematically assessed. In the present study, we performed a genome-wide association study of plasma liver-enzyme levels in three populations (total n = 7715) with replication in three additional cohorts (total n = 4704). We identified two loci influencing plasma levels of alanine-aminotransferase (ALT) (CPN1-ERLIN1-CHUK on chromosome 10 and PNPLA3-SAMM50 on chromosome 22), one locus influencing gamma-glutamyl transferase (GGT) levels (HNF1A on chromosome 12), and three loci for alkaline phosphatase (ALP) levels (ALPL on chromosome 1, GPLD1 on chromosome 6, and JMJD1C-REEP3 on chromosome 10). In addition, we confirmed the associations between the GGT1 locus and GGT levels and between the ABO locus and ALP levels. None of the ALP-associated SNPs were associated with other liver tests, suggesting intestine and/or bone specificity. The mechanisms underlying the associations may involve cis- or trans-transcriptional effects (some of the identified variants were associated with mRNA transcription in human liver or lymphoblastoid cells), dysfunction of the encoded proteins (caused by missense variations at the functional domains), or other unknown pathways. These findings may help in the interpretation of liver-enzyme tests and provide candidate genes for liver diseases of viral, metabolic, autoimmune, or toxic origin. The specific associations with ALP levels may point to genes for bone or intestinal diseases.
Also flagged:axonsaction potentialsnetrin-1in colorectal cancermyelinparanodes
Journal Article2008-10-01✓ 5 SnippetsJarjour AA, Bull SJ, Almasieh M, Rajasekharan S, Baker KA, Mui J, Antel JP, Di Polo A, Kennedy TE.
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…colorectal cancer (DCC…
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…in colorectal cancer (DCC) are enriched at…
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…of netrin-1 orDCCfunction, oligodendroglial par…
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…Lack ofDCCor netrin-1 resulted…
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…for netrin-1 andDCCregulating the maintenance…
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Paranodal axoglial junctions are essential for the segregation of myelinated axons into distinct domains and efficient conduction of action potentials. Here, we show that netrin-1 and deleted in colorectal cancer (DCC) are enriched at the paranode in CNS myelin. We then address whether netrin-1 signaling influences paranodal adhesion between oligodendrocytes and axons. In the absence of netrin-1 or DCC function, oligodendroglial paranodes initially develop and mature normally but later become disorganized. Lack of DCC or netrin-1 resulted in detachment of paranodal loops from the axonal surface and the disappearance of transverse bands. Furthermore, the domain organization of myelin is compromised in the absence of netrin-1 signaling: K+ channels inappropriately invade the paranodal region, and the normally restricted paranodal distribution of Caspr expands longitudinally along the axon. Our findings identify an essential role for netrin-1 and DCC regulating the maintenance of axoglial junctions.
Also flagged:venous diseaseChronic venous diseaseCVDironmetalloproteinasesMMPs
Journal Article2008-10-01✓ 1 SnippetZamboni P, Lanzara S, Mascoli F, Caggiati A, Liboni A.
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…of the commonHFEgene's mutations C282Y…
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Chronic venous disease (CVD), mainly due to venous reflux or, sometimes, to venous outflow obstruction, produces a microcirculatory overload leading to the impairment of venous drainage. Venous drainage depends primarily on a major hemodynamic parameter called trans-mural pressure (TMP). TMP is increased in patients affected by CVD, leading to impaired tissue drainage, and, consequently, facilitating the beginning of the inflammatory cascade. Increased TMP determines red blood cell extravasation and either dermal hemosiderin deposits or iron laden-phagocytes. Iron deposits are readily visible in the legs of all patients affected by severe CVD. Local iron overload could generate free radicals or activate a proteolytic hyperactivity of metalloproteinases (MMPs) and/or downregulate tissue inhibitors of MMPs. These negative effects are particularly evident in carriers of the common HFE gene's mutations C282Y and H63D, because intracellular iron deposits of mutated macrophages have less stability than those of the wild type, inducing a significant oxidative stress. It has been demonstrated that such genetic variants increase the risk of ulcers and advance the age of ulcer onset, respectively. The iron-dependent vision of inflammation in CVD paves the way to new therapeutic strategies including the deliberate induction of iron deficiency as a treatment modality for non-healing and/or recurrent venous leg ulcers. The inflammatory cascade in CVD shares several aspects with that activated in the course of multiple sclerosis, an inflammatory and neurodegenerative disease of unknown origin in which the impairment of cerebral venous outflow mechanisms has been recently demonstrated.
Mucormycosis (zygomycosis) is an acute and often fatal opportunistic fungal infection. Predisposing factors in the development of mucormycosis are nonspecific and include hyperglycemia, hematologic malignancies, neutropenia, pharmacologic immunosuppression, solid organ or bone marrow/stem cell transplantation, burns, trauma, malnutrition, and intravenous drug use. Mucormycosis has also been described in patients with iron and aluminum overload, patients on dialysis, and patients receiving iron chelating therapy. We describe a 75-year-old man with myelodysplastic syndrome and iron overload secondary to multiple red blood cell transfusions who had been treated with deferoxamine chelation therapy. He was admitted to the hospital for atrial fibrillation, developed multiple organ failure, and died. Pulmonary invasive mucormycosis was demonstrated at autopsy. This case further documents an association between invasive mucormycosis, iron overload, and deferoxamine therapy.
<h4>Aim</h4>To study the possible association between chronic pancreatitis (CP) and liver cirrhosis (LC) of alcoholic etiology, after excluding any other causes.<h4>Methods</h4>One hundred and forty consecutive alcoholic patients were subdivided into three groups: CP (n = 53), LC (n = 57), and asymptomatic alcoholic (n = 30). Clinical, biochemical and morphological characteristics, Child-Pugh index, indocyanine green test, and fecal pancreatic elastase-1 test were assessed.<h4>Results</h4>In patients with cirrhosis, major clinical manifestations of CP such as pancreatic pain and steatorrhea, as well as imaging alterations of CP such as calcifications, duct dilation and pseudocysts were absent; insulin-dependent diabetes was present in 5.3% of cases, and elastase-1 test was altered in only 7%, and severely altered in none. In patients with CP, clinical characteristics of cirrhosis such as ascites, encephalopathy and gastrointestinal hemorrhage were present in one case, Child-Pugh grade > A in 5.7%, and altered indocyanine green test in 1.9% cases. In asymptomatic alcoholism, there was only a non-coincident alteration of elastase-1 test and indocyanine test in 14.8% and 10%, respectively, but other characteristics of cirrhosis or CP were absent. An inverse correlation (r = -0.746) between elastase-1 test and indocyanine test was found in alcoholic patients.<h4>Conclusion</h4>There is a scarce coincidence in clinical and morphological alterations among patients with CP or LC of alcoholic etiology, but an inverse correlation between pancreatic and liver function tests. These findings support that these alcoholic diseases evolve in a different manner and have different etiopathogenesis.
Also flagged:pancreatic carcinomacell growthDPC4pancreatic adenocarcinomavascular endothelial growth factorVEGF
Journal Article2008-10-01✓ 1 SnippetShen W, Tao GQ, Li DC, Zhu XG, Bai X, Cai B.
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…DCC…
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<h4>Aim</h4>To detect the expression of DPC4 in malignant and non-malignant specimens of human pancreas, and observe the inhibition of retroviral pLXSN containing DPC4 on pancreatic carcinoma cells in vitro.<h4>Methods</h4>The expression of DPC4 was determined in 40 pancreatic adenocarcinoma and 36 non-malignant pancreatic specimens by reverse-transcriptase polymerase chain reaction (RT-PCR) and immunohisto-chemistry. Furthermore, we constructed retroviral vectors containing DPC4, which then infected the pancreatic carcinoma cell line BxPC-3. Cell growth in vitro after being infected was observed, and the vascular endothelial growth factor (VEGF) mRNA level in the daughter cells was determined by semi-quantitative PCR assay.<h4>Results</h4>The RT-PCR assay showed a positive rate of DPC4 mRNA in 100% (36/36) of normal specimens, compared to 40% (16/40) in adenocarcinoma specimens. The regional and intense positive cases of DPC4 expression in adenocarcinoma detected by immunohistochemistry were 10 and four, whereas it was all positive expression in normal tissues. There was a significant difference of DPC4 expression between them. The stable expression of DPC4 in the pancreatic carcinoma cells BxPC-3 could be resumed by retroviral vector pLXSN transfection, and could inhibit cell growth in vitro. Rather, DPC4 could decrease VEGF mRNA transcription levels.<h4>Conclusion</h4>The deletion of DPC4 expression in pancreatic carcinoma suggests that loss of DPC4 may be involved in the development of pancreatic carcinoma. The retroviral vector pLXSN containing DPC4 can inhibit the proliferation of pancreatic carcinoma cells, and down-regulate the level of VEGF.
Also flagged:serotonin transporterlichen simplex chronicusserotonin5-hydroxytryptamine-pathogenesis
Journal Article2008-10-01✓ 4 SnippetsKirtak N, Inaloz HS, Akçali C, Erdal E, Herken H, Yildirim M, Erguven HG.
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…Dysregulation of serotonergic pathways has been implicated in the pathogenesis of many complex neuropsychiatric diseases.<h4>Objectives</h4>The purpose of this study was to evaluate the relationship between lichen simplex chronicus and dysfunction and serotonin transporter (5-HTT) gene polymorphism.<h4>Methods</h4>Thirty-nine patients with lichen simplex chronicus and 61 healthy control subjects were examined.<h4>Results</h4>The results for the patients and control subjects were not significantly different (P > 0.05) in long/long (L/L) and long/short (L/S) genotypes of 5-HTT gene-linked polymorphic region (HTTLPR) polymorphism, but short/short S/S genotype was lower in lichen simplex chronicus patients (17.9%) than in controls (42.6%).…
<h4>Background</h4>The serotonin (5-hydroxytryptamine; 5-HT) is a key neurotransmitter in the central nervous system and a responsible mediator for the itch. Dysregulation of serotonergic pathways has been implicated in the pathogenesis of many complex neuropsychiatric diseases.<h4>Objectives</h4>The purpose of this study was to evaluate the relationship between lichen simplex chronicus and dysfunction and serotonin transporter (5-HTT) gene polymorphism.<h4>Methods</h4>Thirty-nine patients with lichen simplex chronicus and 61 healthy control subjects were examined.<h4>Results</h4>The results for the patients and control subjects were not significantly different (P > 0.05) in long/long (L/L) and long/short (L/S) genotypes of 5-HTT gene-linked polymorphic region (HTTLPR) polymorphism, but short/short S/S genotype was lower in lichen simplex chronicus patients (17.9%) than in controls (42.6%). This difference was statistically significant (P = 0.028). The results for the patients and control subjects were not significantly different in 12/12, 10/12 and 10/10 genotypes of variable number of tandem repeat (VNTR) polymorphism (P > 0.05). Beck depression inventory (BDI) scores and symptom checklist-90-revised (SCL-90) psychotic subscale were overrepresented significantly in the 12/12 genotypes than 10/12 genotypes. State and Trait Anxiety Inventory tests (STAI-I and -II) point averages were not statistically significant (P > 0.05)<h4>Conclusion</h4>S/S genotypes of HTTLPR polymorphism in the 5-HTT gene may be related to lichen simplex chronicus and that patients who have 12/12 genotypes of VNTR polymorphism may be affected psychiatrically.
Also flagged:EthanolGAPDHNR1NR2ANR2Bcirrhosis of the liver
Journal Article2008-10-01✓ 1 SnippetRidge JP, Ho AM, Innes DJ, Dodd PR.
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…5-HTT…
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Ethanol is a modulator at the N-methyl-d-aspartate class of glutamate receptors in the brain. In animal studies the receptor adapts to sustained ethanol exposure through altered expression of the subunits that make up the receptor complex. We used real-time RT-PCR normalized to GAPDH to assay NR1, NR2A, and NR2B subunit mRNA in superior frontal and primary motor cortex tissue obtained at autopsy from chronic alcoholics with and without co-morbid cirrhosis of the liver, and from matched controls. The expression of all three subunits was significantly lower in both areas of cirrhotic alcoholics than in the corresponding areas in both controls and alcoholics without co-morbid disease, who did not differ significantly from each other. The decrease was area-dependent when cases were partitioned by the 5-HTTLPR allele. Thus, polymorphisms in one gene can have a significant effect on the expression of a second, unrelated, gene. The expression of the N-methyl-d-aspartate glutamate receptor complex is under multifactorial control.
Also flagged:psychosismethamphetamineMAPMAP psychosisserotonin transporter5-HTTLPR
Journal Article2008-10-01✓ 5 SnippetsEzaki N, Nakamura K, Sekine Y, Thanseem I, Anitha A, Iwata Y, Kawai M, Takebayashi K, Suzuki K, Takei N, Iyo M, Inada T, Iwata N, Harano M, Komiyama T, Yamada M, Sora I, Ujike H, Mori N.
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…Prolonged MAP use, combined with the high frequency of 5-HTTLPR S-alleles, may lead to reduced 5-HTT levels and 5-HT(1A) receptor-binding potential in the brain, resulting in the dysfunction of the serotonergic system.…
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…may lead to reduced 5-HTT levels and 5-HT ( 1A ) receptor-binding potential in the brain…
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…the serotonin transporter (5-HTT) density in global…
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…transcriptional activity of5-HTT, with S alleles…
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…lead to reduced5-HTTlevels and 5-HT(1A)…
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Accumulating evidence suggests that genetic factors contribute to the vulnerability to methamphetamine (MAP) abuse and associated psychiatric symptoms. Chronic MAP abuse leads to psychosis, which may be of a transient or a prolonged type. Serotonergic dysfunction has been proposed as one of the contributory factors in the development of MAP psychosis. Our PET studies revealed that the serotonin transporter (5-HTT) density in global brain regions is significantly lower in MAP abusers. In this study, we examined the role of a functional polymorphism in the 5' flanking region of the 5-HTT gene (5-HTTLPR) in the development of MAP psychosis in a Japanese population. We analyzed DNA samples from 166 MAP patients (95 with transient and 71 with prolonged psychosis) and 197 age-, sex-, and geographic-origin-matched healthy controls. Patients were also subdivided according to the presence (n= 119) or absence (n= 148) of spontaneous relapse. We observed significant genotypic association of the 5-HTTLPR polymorphism with MAP psychosis (P= 0.022), particularly in patients who show prolonged psychosis. The frequency of the S allele in patients with prolonged psychosis was significantly higher than that of the controls (P= 0.045); it was further higher in patients with prolonged psychosis with spontaneous relapse (P= 0.004). 5-HTTLPR has been suggested to regulate the transcriptional activity of 5-HTT, with S alleles showing lesser transcriptional efficiency and also lower 5-HT(1A) receptor-binding potential. Prolonged MAP use, combined with the high frequency of 5-HTTLPR S-alleles, may lead to reduced 5-HTT levels and 5-HT(1A) receptor-binding potential in the brain, resulting in the dysfunction of the serotonergic system. Thus, we suggest a possible role for the 5-HTTLPR polymorphism in MAP psychosis.
Also flagged:dependence syndromeserotonin-axon5axons
Journal Article2008-10-01No SnippetsCowan RL, Roberts DM, Joers JM.
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MDMA (3,4 methylenedioxymethamphetamine) has been used by millions of people worldwide as a recreational drug. The terms "MDMA" and "Ecstasy" are often used synonymously, but it is important to note that the purity of Ecstasy sold as MDMA is not certain. MDMA use is of public health concern, not so much because MDMA produces a common or severe dependence syndrome, but rather because rodent and nonhuman primate studies have indicated that MDMA (when administered at certain dosages and intervals) can cause long-lasting reductions in markers of brain serotonin (5-HT) that appear specific to fine-diameter axons arising largely from the dorsal raphe nucleus (DR). Given the popularity of MDMA, the potential for the drug to produce long-lasting or permanent 5-HT axon damage or loss, and the widespread role of 5-HT function in the brain, there is a great need for a better understanding of brain function in human users of this drug. To this end, neuropsychological, neuroendocrine, and neuroimaging studies have all suggested that human MDMA users may have long-lasting changes in brain function consistent with 5-HT toxicity. Data from animal models leads to testable hypotheses regarding MDMA's effects on the human brain. Because neuropsychological and neuroimaging findings have focused on the neocortex, a cortical model is developed to provide a context for designing and interpreting neuroimaging studies in MDMA users. Aspects of the model are supported by the available neuroimaging data, but there are controversial findings in some areas and most findings have not been replicated across different laboratories and using different modalities. This paper reviews existing findings in the context of a cortical model and suggests directions for future research.
Attention-deficit/hyperactivity disorder (ADHD) and tobacco smoking are among the most common and costly psychiatric and behavioral problems. The rates of co-occurrence of these two common problems are larger than expected by chance. Despite progress in identifying the neural and genetic substrates of each, the mechanisms underlying the high rates of comorbidity between ADHD and smoking remain largely unknown. We propose that ADHD and smoking involve dysregulation of dopaminergic and nicotinic-acetylcholinergic circuits and that these aberrations are likely to arise, at least in part, from genetic variations. This review describes an integrative model of the ADHD-smoking comorbidity, with an emphasis on shared neuropharmacological mechanisms. We first describe the prevalence of smoking among ADHD patients. We then describe how ADHD influences stages of smoking behavior (e.g., initiation, maintenance, and relapse). We review common potential genetic substrates of ADHD and smoking, focusing on genes that regulate monoaminergic neurotransmission. We review the behavioral and neuropharmacological bases of smoking and ADHD, focusing on the modulatory roles of nicotine on attention and behavioral control. Finally, we discuss the implications of this model for prevention and clinical outcomes.
Also flagged:mTORbreast cancerAktmammalian target of rapamycinCell proliferationrapamycin
Journal Article2008-10-01No SnippetsGhayad SE, Bieche I, Vendrell JA, Keime C, Lidereau R, Dumontet C, Cohen PA.
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Activation of the Akt/mammalian target of rapamycin (mTOR) pathway has been shown to be associated with resistance to endocrine therapy in estrogen receptor alpha (ERalpha)-positive breast cancer patients. Utmost importance is attached to strategies aimed at overcoming treatment resistance. In this context, this work aimed to investigate whether, in breast cancer cells, the use of an mTOR inhibitor would be sufficient to reverse the resistance acquired after exposure to endocrine therapy. The ERalpha-positive human breast adenocarcinoma derived-MCF-7 cells used in this study have acquired both cross-resistance to hydroxy-tamoxifen (OH-Tam) and to fulvestrant and strong activation of the Akt/mTOR pathway. Cell proliferation tests in control cells demonstrated that the mTOR inhibitor rapamycin enhanced cell sensitivity to endocrine therapy when combined to OH-Tam or to fulvestrant. In resistant cells, rapamycin used alone greatly inhibited cell proliferation and reversed resistance to endocrine therapy by blocking the agonist-like activity of OH-Tam on cell proliferation and bypassing fulvestrant resistance. Reversion of resistance by rapamycin was associated with increased ERalpha protein expression levels and modification of the balance of phospho-ser167 ERalpha/total ERalpha ratio. Pangenomic DNA array experiments demonstrated that the cotreatment of resistant cells with fulvestrant and rapamycin allowed the restoration of 40% of the fulvestrant gene-expression signature. Taken together, data presented herein strongly support the idea that mTOR inhibitor might be one of the promising therapeutic approaches for patients with ERalpha-positive endocrine therapy-resistant breast cancers.
…Our findings demonstrate the usefulness of real-time PCR for the simultaneous detection of mutations in the HFE gene, which allows a reduction of a significant amount of time in sample processing compared to the PCR-RFLP method, eliminates the use of toxic reagents, reduces the risk of contamination in the laboratory, and enables full process automation.…
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…hemochromatosis gene (HFE…
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…mutations in thehemochromatosisgene using quenched-FRET…
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…detected in thehemochromatosisgene (HFE): C282Y,…
Hereditary hemochromatosis (HH) is a common autosomal disorder of iron metabolism mainly affecting Caucasian populations. Three recurrent disease-associated mutations have been detected in the hemochromatosis gene (HFE): C282Y, H63D, and S65C. Although HH phenotype has been associated with all three mutations, C282Y is considered the most relevant mutation responsible for hemochromatosis. Clinical complications of HH include cirrhosis of the liver, congestive cardiac failure and cardiac arrhythmias, endocrine pancreatic disease, which can be prevented by early diagnosis and treatment. Therefore, a reliable genotyping method is required for presymptomatic diagnosis. We describe the simultaneous detection of the C282Y, H63D and S65C mutations in the hemochromatosis gene by real-time PCR followed by melting curve analysis using fluorescence resonance energy transfer (FRET) probes. The acceptor fluorophore may be replaced by a quencher, increasing multiplex possibilities. Real-time PCR results were compared to the results of sequencing and conventional PCR followed by restriction digestion and detection by agarose gel electrophoresis (PCR-RFLP). Genotypes from 80 individuals obtained both by the conventional PCR-RFLP method and quenched-FRET real-time PCR were in full agreement. Sequencing also confirmed the results obtained by the new method, which proved to be an accurate, rapid and cost-effective diagnostic assay. Our findings demonstrate the usefulness of real-time PCR for the simultaneous detection of mutations in the HFE gene, which allows a reduction of a significant amount of time in sample processing compared to the PCR-RFLP method, eliminates the use of toxic reagents, reduces the risk of contamination in the laboratory, and enables full process automation.
…Several genes related to cell cycle regulation, such as CDK5RAP1, RBBP8, and SERTAD1, were up-regulated in these tumors.…
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…regulation, such asCDK5RAP1, RBBP8, and SERTAD1,…
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The antitumor properties of the Merlot grape (and Merlot wine) polyphenols were evaluated in relation to their ability to modulate gene expression in developing tumors using an athymic nude mouse model transplanted with the estrogen receptor-negative MDA-MB231 cells. Groups of mice were fed a modified AIN 93G diet (Research Diets Inc, New Brunswick, NJ) with the experimental groups receiving 100 mg/kg body weight equivalent of polyphenols by gavage 3 times per week. After 1 week of acclimation and another week of polyphenol supplementation, MDA-MB231 cells were transplanted and the growth patterns of the tumors monitored. After 33 days of tumor growth, the animals were euthanized, the tumors isolated, and gene expression profiles analyzed using signal transduction and cell cycle arrays. The development of tumors was almost totally arrested in grape polyphenol-treated mice. Total polyphenols isolated from the wine were more effective in reducing tumor growth as compared with a hydrophobic polyphenol fraction isolated from the wine, showing a 50% and 60% reduction in tumor growth on day 33, respectively. Analysis of gene expression showed that genes such as CDK2, FAS, LEF1, PRKCE, and PTGS2, belonging to the NFkappaB, phospholipase C, and calcium signaling pathways, were down-regulated in tumors that developed in grape polyphenol-treated mice. Several genes related to cell cycle regulation, such as CDK5RAP1, RBBP8, and SERTAD1, were up-regulated in these tumors. Changes in the expression of these genes were less pronounced in tumors of wine polyphenol-treated mice. The study highlights the potential influences of dietary polyphenolic components on gene expression in estrogen receptor-negative tumors and its relation to inhibition of tumor growth.
Also flagged:peroxiredoxin 6Gpx1Annexin Vthiobarbituric aciddiphenyl-pyrenyl phospholine
Journal Article2008-10-01✓ 5 SnippetsWang Y, Lu Q, Sheldon FS, Ho YS, Phelan SA, Beers MF, Fisher AB.
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…Prdx6 plays a critical role in defending acute oxidative lung injury and its function of defending cell apoptosis and cell membrane lipid peroxidation suggests its unique cell-based protective effect.…
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…peroxiredoxin 6 (Prdx6) in acute lung injury…
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…of peroxiredoxin 6 (Prdx6) in acute lung…
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…used to determinePrdx6or Gpx1 protein…
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…100% O2 exposure,Prdx6-/- mice presented 24…
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<h4>Objective</h4>To confirm the antioxidant protective effect of peroxiredoxin 6 (Prdx6) in acute lung injury in mice.<h4>Methods</h4>Lung injury or lung alveolar type II epithelial cell (AEC II) injury models were induced in mice by 100% O2 exposure or H2O2 treatments. Mice and AEC II cell survival rate or BALF analysis were applied for evaluating the degree of acute lung injury. Western Blot assay was used to determine Prdx6 or Gpx1 protein expression in lung. Annexin V staining method was applied to detect cell apoptosis on cultured AEC II cell, and thiobarbituric acid reactive substance (TBARS) measurement and diphenyl-1-pyrenyl phospholine (DPPP) assays were separately used to measure the level of lipid peroxidation in mice lung and AEC II cell membrane.<h4>Results</h4>Under 100% O2 exposure, Prdx6-/- mice presented 24 h shorter survival time compared to wild type (WT) mice, on the contrary, Prdx6 gene over-expressed (Tg Prdx6) mice showed enhanced mice survival; meanwhile, the degree of AEC II cell injury had H2O2-dose dependent pattern with interactive relationship of Prdx6 protection. Under 100% O2 exposure for 72 h, it caused 7-fold decreased Gpx1 expression in Prdx6-/- mouse lung with no remarkable decrease of Prdx6 expression in Gpx1-/- mice. The percentage of apoptotic cells was significantly increased in AEC II cells from Prdx6-/- mice, and the percentage of AEC II apoptotic cells from Tg Prdx6 kept consistently around 10% under H2O treatments; also, the lipid peroxidation level of AEC II cell membrane was the highest in the group of Prdx6-/- mice, which was about 2 or 4-fold increased compared to the groups of WT or Tg Prdx6, separately; meanwhile, the lipid peroxidation level in Prdx6-/- mice, was also the highest compared to the other groups.<h4>Conclusions</h4>Prdx6 plays a critical role in defending acute oxidative lung injury and its function of defending cell apoptosis and cell membrane lipid peroxidation suggests its unique cell-based protective effect.
Also flagged:irontransaminaseshereditary hemochromatosisHHAspartate transaminaseAST
Journal Article2008-10-01✓ 1 SnippetCastiella A, Zapata E, Otazua P, Fernández J, Alustiza JM, Ugarte M, Legasa L, Galardi A, Ugalde A, Barredo I, Arriola JA.
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…patients with phenotypichemochromatosis].…
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<h4>Objective</h4>To determine whether the product of multiplying age by liver iron concentration (LIC) (fibrosis index; cut-off, 480,000), platelets, transaminases, and ferritin values are related to the risk of high grade fibrosis.<h4>Methods</h4>A retrospective study of 32 patients with hereditary hemochromatosis (HH) with phenotypic expression. All patients had a liver biopsy with LIC.<h4>Results</h4>In 7 patients a magnetic resonance imaging (MRI) scan (1.5 T) was obtained with LIC following Alustiza's protocol. Liver biopsy: fibrosis grade (F) 0-2 in 23 patients; F 3-4 in 9. Fibrosis index (FI) showed a specificity of 68%, sensitivity of 85.7%, positive predictive value (PPV) of 42.8%, and negative predictive value (NPV) of 94.4% for high-grade fibrosis. Platelet count ( < 200,000) revealed a NPV of 94.7% for F3-4. Aspartate transaminase (AST) levels above the upper limit of normal showed a NPV of 94.4%; ferritin levels (> 1,000) a NPV of 75%, and MRI-derived LIC x age (> 480,000) a NPV of 80%. The combination of FI (either by biopsy or MRI) with transaminases, and of platelets with transaminases revealed a NPV of 100%.<h4>Conclusions</h4>FI > 480,000 and platelets < 200,000 have the highest sensitivity for high-degree fibrosis prediction. A negative result allows to discard significant fibrosis in 94% of cases. MRI allows a good fibrosis prediction.
Journal Article2008-10-01✓ 1 SnippetPoynard T, Morra R, Ingiliz P, Imbert-Bismut F, Thabut D, Messous D, Munteanu M, Massard J, Benhamou Y, Ratziu V.
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Discussion)
…Inhemochromatosis, several algorithms using…
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Liver biopsy, owing to its limitations and risks, is an imperfect gold standard for assessing the severity of the most frequent chronic liver diseases chronic hepatitis C (HCV), B (HBV) non alcoholic (NAFLD) and alcoholic (ALD) fatty liver diseases. This review summarizes the advantages and the limits of the available biomarkers of liver fibrosis. Among a total of 2,237 references, a total of 14 validated serum biomarkers have been identified between 1991 and 2008. Nine were not patented and five were patented. Two alternatives to liver biopsy were the most evaluated FibroTest and Fibroscan. For FibroTest, there was a total of 38 different populations including 7,985 subjects with both FibroTest and biopsy (4,600 HCV, 1,580 HBV, 267 NAFLD, 524 ALD, and 1014 mixed). For Fibroscan, there was a total of 11 published studies including 2,260 subjects (1,466 HCV, 95 cholestatic liver disease, and 699 mixed). For FibroTest, the mean diagnostic value for the diagnosis of advanced fibrosis assessed using standardized area under the ROC curves was 0.84 (95% confidence interval 0.83-0.86), without a significant difference between the causes of liver disease, hepatitis C, hepatitis B, and alcoholic or non alcoholic fatty liver disease. High-risk profiles of false negative/false positive of FibroTest, mainly Gilbert syndrome, hemolysis and acute inflammation, are present in 3% of the populations. In case of discordance between biopsy and FibroTest, half of the failures can be due to biopsy; the prognostic value of FibroTest is at least similar to that of biopsy in HCV, HBV and ALD. In conclusion this overview of evidence-based data suggests that biomarkers could be used as an alternative to liver biopsy for the first line assessment of fibrosis stage in the four most common chronic liver diseases, namely HCV, HBV, NAFLD and ALD. Neither biomarkers nor biopsy alone is sufficient for taking a definite decision in a given patient; all the clinical and biological data must be taken into account. There is no evidence based data justifying biopsy as a first line estimate of liver fibrosis. Health authorities in some countries have already approved validated biomarkers as the first line procedure for the staging of liver fibrosis.
Also flagged:inflammatory bowel diseasethrombophiliainflammatory responseactiveC-reactive proteinanticardiolipin antibodies
Journal Article2008-10-01✓ 2 SnippetsMaher MM, Soloma SH.
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…C and S,antithrombin-III(AT-III), and factor…
Abstract)
…However,antithrombin-IIIlevels were significantly…
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<h4>Background/aims</h4>Thromboembolic disease has been recognized as a complication of inflammatory bowel disease (IBD). The relative contributions of inherited or acquired thrombophilia and the inflammatory response to the mechanism of this tendency are unclear. Thrombotic events are more common in active disease although significant numbers also occur spontaneously. The aim of this study was to investigate common thrombophilic markers in patients with active IBD.<h4>Methods</h4>Twenty-six patients with IBD who had active disease, and 40 sex- and age-matched non-IBD patients were recruited into the study. For all the subjects, complete blood counts, C-reactive protein levels, erythrocyte sedimentation rate, International normalized ratio, activated partial thromboplastin time, and levels of lupus anticoagulant, anticardiolipin antibodies (ACA IgG), proteins C and S, antithrombin-III (AT-III), and factor V were measured.<h4>Results</h4>The International normalized ratio, activated partial thromboplastin time, and levels of proteins C and S were comparable between the two groups. However, antithrombin-III levels were significantly lower in the IBD group as compared with that in the healthy control group (P < 0.001). ACA IgG was detected in one patient in the IBD group. Factor V Leiden mutation was present in 3.8% of the patients in the IBD group, whereas the prevalence was 2.5% in the control group. Significantly elevated platelet counts were observed in patients with active Crohn's disease compared with that in the control group (P < 0.001), but they were not significantly increased in active ulcerative colitis (P = 0.231).<h4>Conclusions</h4>The present study failed to establish a strong association between the common thrombophilic markers and the active clinical course of IBD, with the exception of high platelet counts and lower levels of AT-III in the IBD group as compared with those in the control group. All other parameters of thrombophilia were comparable between the two groups.
Also flagged:SerotoninDopamineaggressionmental disordersdepressionsubstance abuse
Journal Article2008-10-01No SnippetsSeo D, Patrick CJ, Kennealy PJ.
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Impulsive aggression is characterized by an inability to regulate affect as well as aggressive impulses, and is highly comorbid with other mental disorders including depression, suicidal behavior, and substance abuse. In an effort to elucidate the neurobiological underpinnings of impulsive aggression and to help account for its connections with these other disorders, this paper reviews relevant biochemical, brain imaging, and genetic studies. The review suggests that dysfunctional interactions between serotonin and dopamine systems in the prefrontal cortex may be an important mechanism underlying the link between impulsive aggression and its comorbid disorders. Specifically, serotonin hypofunction may represent a biochemical trait that predisposes individuals to impulsive aggression, with dopamine hyperfunction contributing in an additive fashion to the serotonergic deficit. The current paper proposes a modified diathesis-stress model of impulsive aggression in which the underlying biological diathesis may be deficient serotonergic function in the ventral prefrontal cortex. This underlying disposition can be manifested behaviorally as impulsive aggression towards oneself and others, and as depression under precipitating life stressors. Substance abuse associated with impulsive aggression is understood in the context of dopamine dysregulation resulting from serotonergic deficiency. Also discussed are future research directions in the neurobiology of impulsive aggression and its comorbid disorders.
Also flagged:viral capsidsribosomesnucleosomesmembraneproteasomepolypeptide
Journal Article2008-10-01No SnippetsGaczynska M, Osmulski PA.
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The term "biological complexes" broadly encompasses particles as diverse as multisubunit enzymes, viral capsids, transport cages, molecular nets, ribosomes, nucleosomes, biological membrane components and amyloids. The complexes represent a broad range of stability and composition. Atomic force microscopy offers a wealth of structural and functional data about such assemblies. For this review, we choose to comment on the significance of AFM to study various aspects of biology of selected nonmembrane protein assemblies. Such particles are large enough to reveal many structural details under the AFM probe. Importantly, the specific advantages of the method allow for gathering dynamic information about their formation, stability or allosteric structural changes critical for their function. Some of them have already found their way to nanomedical or nanotechnological applications. Here we present examples of studies where the AFM provided pioneering information about the biology of complexes, and examples of studies where the simplicity of the method is used toward the development of potential diagnostic applications.
Also flagged:cardiovascular diseasecoronary heart diseaseacute myocardial infarction
Journal Article2008-10-01✓ 5 Snippetsvan der A DL, Rovers MM, Grobbee DE, Marx JJ, Waalen J, Ellervik C, Nordestgaard BG, Olynyk JK, Mills PR, Shepherd J, Grandchamp B, Boer JM, Caruso C, Arca M, Meyer BJ, van der Schouw YT.
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…The results of this large individual patient data meta-analysis do not support the view that HFE gene mutations are associated with an increased risk of coronary heart disease or acute myocardial infarction.…
Title)
…Mutations in the HFE gene and cardiovascular disease risk: an individual patient data meta-analysis of 53 880 subjects.…
Abstract)
…HFE gene mutations are associated with an increased risk of coronary heart disease…
Title)
…HFE gene and cardiovascular disease…
Abstract)
…HFE) gene increase cardiovascular disease…
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<h4>Background</h4>Whether mutations in the hemochromatosis (HFE) gene increase cardiovascular disease risk is still undetermined. The main reason is the low frequency of the mutations, in particular of the compound C282Y/H63D genotype. We combined the data of 11 observational studies for an individual patient data meta-analysis.<h4>Methods and results</h4>Individual patient data were obtained from published as well as unpublished studies that had information available on the C282Y mutation as well as the H63D mutation in relation to coronary heart disease risk. Individual records were provided on each of the 53 880 participants in 11 studies. In total, 10 541 patients with coronary events were documented, of whom 5724 had an acute myocardial infarction. The crude and adjusted association between HFE genotypes and coronary events was examined by logistic regression analysis. We explored potential effect modification of the association between traditional cardiovascular risk factors and coronary events by HFE genotypes. After full adjustment, the odds ratio for coronary heart disease was 1.12 (95% CI, 0.92 to 1.37) for subjects with the compound heterozygous (C282Y/H63D) genotype relative to those with the wild-type/wild-type genotype. The odds ratios for C282Y/C282Y, C282Y/wild-type, H63D/H63D, and H63D/wild-type were 0.78 (95% CI, 0.49 to 1.26), 0.98 (95% CI, 0.90 to 1.07), 1.16 (95% CI, 0.97 to 1.38), and 1.07 (95% CI, 1.00 to 1.14), respectively. There was no evidence for effect modification.<h4>Conclusions</h4>The results of this large individual patient data meta-analysis do not support the view that HFE gene mutations are associated with an increased risk of coronary heart disease or acute myocardial infarction.
Also flagged:hepatic tumourshepatic insufficiencytumourstumourcirrhosisUracil
Journal Article2008-10-01✓ 1 SnippetPopa B, Popiel M, Gulie L, Turculeţ C, Beuran M.
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…Aspergillus flavus ),hemochromatosis, Wilson disease or…
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First transcatheter embolization of hepatic artery has been materializing in 1974, in France, for unresectable hepatic tumours. Then, this treatment has become use enough in many countries, especially in Japan, where primary hepatic tumours are very frequent. In this article, we present procedures of interventional endovascular treatment for primary hepatic tumours: chemoembolization, intra-arterial chemotherapy. The study comprises patients with primary hepatic tumours investigated by hepatic-ultrasound and contrast-enhanced CT or MRI. DSA-hepatic angiography is very important to verify the accessory hepatic supply. It has been performed selective catheterization of right/left hepatic branches followed by cytostatics injection. Most of the patients have benefit by hepatic chemoembolization (cytostatics, Lipiodol and embolic materials). The selective intra-arterial chemotherapy (cytostatics without Lipiodol) was performing in cases with contraindications for Lipiodol or embolic materials injection (cirrhosis-Child C, thrombosis of portal vein, hepatic insufficiency). For treatment of primary hepatic tumours we use 5-F-Uracil, Farmarubicin and Mytomicin C. Less numbers of the reservoirs were placed because financial causes. Chemoembolization was better than procedures without Lipiodol or embolic materials. Lipiodol reached in tumoural tissue and the distribution of Lipiodol harmonises with degree of vascularisation. After the chemoembolization procedure, the diameter of tumours decreased gradually depending on the size of tumour. Effective alternative for unresectable primary hepatic tumours (big size, hepatic dysfunction, and other surgical risk factors) is endovascular interventional treatment.