Also flagged:Polyunsaturated fatty acidsneurodegenerative diseasesdendritessodium dodecyl sulfatecytoplasmα-Synuclein
Journal Article2007-11-30✓ 1 SnippetAssayag K, Yakunin E, Loeb V, Selkoe DJ, Sharon R.
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The misfolding and aggregation of normally soluble proteins has emerged as a key feature of several neurodegenerative diseases. In Parkinson's disease, progressive loss of dopaminergic neurons is accompanied by polymerization of the cytoplasmic protein alpha-synuclein (alphaS) into filamentous inclusions found in neuronal somata (Lewy bodies) and dendrites (Lewy neurites). Similar alphaS aggregates occur in cortical neurons in dementia with Lewy bodies. Numerous reports now indicate that alphaS can interact with lipids. We previously found that treating dopaminergic cells expressing alphaS with polyunsaturated fatty acids (PUFAs) induced the formation of soluble, sodium dodecyl sulfate-stable oligomers whereas treatment with saturated fatty acids did not. Here, we examine the relevance of alphaS-PUFA interactions to the development of Parkinson's disease-like cytopathology. Exposure of alphaS-overexpressing dopaminergic or neuronal cell lines to physiological levels of a PUFA induced the formation of proteinaceous inclusions in the cytoplasm. Kinetic experiments indicated that PUFA-induced soluble oligomers of alphaS precede these Lewy-like inclusions. Importantly, we found that alphaS oligomers were associated with cyto-toxicity, whereas the development of Lewy-like inclusions appeared to be protective. We conclude that alterations in PUFA levels can lead to aggregation of alphaS and subsequent deposition into potentially cyto-toxic oligomers that precede inclusions in dopaminergic cells.
Also flagged:transcription factorcell cyclecell differentiationtumorTFbinding
Journal Article2007-11-29No SnippetsLee AP, Yang Y, Brenner S, Venkatesh B.
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<h4>Background</h4>Transcription factors (TFs) regulate gene transcription and play pivotal roles in various biological processes such as development, cell cycle progression, cell differentiation and tumor suppression. Identifying cis-regulatory elements associated with TF-encoding genes is a crucial step in understanding gene regulatory networks. To this end, we have used a comparative genomics approach to identify putative cis-regulatory elements associated with TF-encoding genes in vertebrates.<h4>Description</h4>We have created a database named TFCONES (Transcription Factor Genes & Associated COnserved Noncoding ElementS) (http://tfcones.fugu-sg.org) which contains all human, mouse and fugu TF-encoding genes and conserved noncoding elements (CNEs) associated with them. The CNEs were identified by gene-by-gene alignments of orthologous TF-encoding gene loci using MLAGAN. We also predicted putative transcription factor binding sites within the CNEs. A significant proportion of human-fugu CNEs contain experimentally defined binding sites for transcriptional activators and repressors, indicating that a majority of the CNEs may function as transcriptional regulatory elements. The TF-encoding genes that are involved in nervous system development are generally enriched for human-fugu CNEs. Users can retrieve TF-encoding genes and their associated CNEs by conducting a keyword search or by selecting a family of DNA-binding proteins.<h4>Conclusion</h4>The conserved noncoding elements identified in TFCONES represent a catalog of highly prioritized putative cis-regulatory elements of TF-encoding genes and are candidates for functional assay.
Also flagged:EstradiolEstrogenmitochondrialNRF-1transcription factorlung adenocarcinoma
Journal Article2007-11-29No SnippetsMattingly KA, Ivanova MM, Riggs KA, Wickramasinghe NS, Barch MJ, Klinge CM.
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Estrogen has direct and indirect effects on mitochondrial activity, but the mechanisms mediating these effects remain unclear. Others reported that long-term estradiol (E(2)) treatment increased nuclear respiratory factor-1 (NRF-1) protein in cerebral blood vessels of ovariectomized rats. NRF-1 is a transcription factor that regulates the expression of nuclear-encoded mitochondrial genes, e.g. mitochondrial transcription factor A (TFAM), that control transcription of the mitochondrial genome. Here we tested the hypothesis that E(2) increases NRF-1 transcription resulting in a coordinate increase in the expression of nuclear- and mitochondrial- encoded genes and mitochondrial respiratory activity. We show that E(2) increased NRF-1 mRNA and protein in MCF-7 breast and H1793 lung adenocarcinoma cells in a time-dependent manner. E(2)-induced NRF-1 expression was inhibited by the estrogen receptor (ER) antagonist ICI 182,780 and actinomycin D but not by phosphoinositide-3 kinase and MAPK inhibitors, indicating a genomic mechanism of E(2) regulation of NRF-1 transcription. An estrogen response element (ERE) in the NRF-1 promoter bound ER alpha and ER beta in vitro, and E(2) induced ER alpha and ER beta recruitment to this ERE in chromatin immunoprecipitation assays in MCF-7 cells. The NRF-1 ERE activated reporter gene expression in transfected cells. Small interfering RNA to ER alpha and ER beta revealed that ER alpha mediates E(2)-induced NRF-1 transcription. The E(2)-induced increase in NRF-1 was followed by increased TFAM and the transcription of Tfam-regulated mitochondrial DNA-encoded COI and NDI genes and increased mitochondrial biogenesis. Knockdown of NRF-1 blocked E(2) stimulation of mitochondrial biogenesis and activity, indicating a mechanism by which estrogens regulate mitochondrial function by increasing NRF-1 expression.
Also flagged:Anorexia nervosaANbulimia nervosaBNpathogenesissteroids
Journal Article2007-11-29✓ 1 SnippetKaye W.
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Anorexia nervosa (AN) and bulimia nervosa (BN) are related disorders of unknown etiology that most commonly begin during adolescence in women. AN and BN have unique and puzzling symptoms, such as restricted eating or binge-purge behaviors, body image distortions, denial of emaciation, and resistance to treatment. These are often chronic and relapsing disorders, and AN has the highest death rate of any psychiatric disorder. The lack of understanding of the pathogenesis of this illness has hindered the development of effective interventions, particularly for AN. Individuals with AN and BN are consistently characterized by perfectionism, obsessive-compulsiveness, and dysphoric mood. Individuals with AN tend to have high constraint, constriction of affect and emotional expressiveness, ahendonia and asceticism, whereas individuals with BN tend to be more impulsive and sensation seeking. Such symptoms often begin in childhood, before the onset of an eating disorder, and persist after recovery, suggesting they are traits that create a vulnerability for developing an ED. There is growing acknowledgement that neurobiological vulnerabilities make a substantial contribution to the pathogenesis of AN and BN. Considerable evidence suggests that altered brain serotonin (5-HT) function contributes to dysregulation of appetite, mood, and impulse control in AN and BN. Brain imaging studies, using 5-HT specific ligands, show that disturbances of 5-HT function occur when people are ill, and persist after recovery from AN and BN. It is possible that a trait-related disturbance of 5-HT neuronal modulation predates the onset of AN and contributes to premorbid symptoms of anxiety, obsessionality, and inhibition. This dysphoric temperament may involve an inherent dysregulation of emotional and reward pathways which also mediate the hedonic aspects of feeding, thus making these individuals vulnerable to disturbed appetitive behaviors. Restricting food intake may become powerfully reinforcing because it provides a temporary respite from dysphoric mood. Several factors may act on these vulnerabilities to cause AN to start in adolescence. First, puberty-related female gonadal steroids or age-related changes may exacerbate 5-HT dysregulation. Second, stress and/or cultural and societal pressures may contribute by increasing anxious and obsessional temperament. Individuals with AN may discover that reduced dietary intake, by reducing plasma tryptophan availability, is a means by which they can modulate brain 5-HT functional activity and anxious mood. People with AN enter a vicious cycle which accounts for the chronicity of this disorder because caloric restriction results in a brief respite from dysphoric mood. However, malnutrition and weight loss, in turn, produce alterations in many neuropeptides and monoamine function, perhaps in the service of conserving energy, but which also exaggerates dysphoric mood. In summary, this article reviews findings in brain chemistry and neuroimaging that shed new light on understanding the psychopathology of these difficult and frustrating disorders.
Also flagged:Amphetaminesmethamphetamineamphetaminebehavioraltranslationalglutamate
Journal Article2007-11-29✓ 1 SnippetPhillips TJ, Kamens HM, Wheeler JM.
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Amphetamines, including methamphetamine, pose a significant cost to society due to significant numbers of amphetamine-abusing individuals who suffer major health-related consequences. In addition, methamphetamine use is associated with heightened rates of violent and property-related crimes. The current paper reviews the existing literature addressing genetic differences in mice that impact behavioral responses thought to be relevant to the abuse of amphetamine and amphetamine-like drugs. Summarized are studies that used inbred strains, selected lines, single-gene knockouts and transgenics, and quantitative trait locus (QTL) mapping populations. Acute sensitivity, neuroadaptive responses, rewarding and conditioned effects are among those reviewed. Some gene mapping work has been accomplished, and although no amphetamine-related complex trait genes have been definitively identified, translational work leading from results in the mouse to studies performed in humans is beginning to emerge. The majority of genetic investigations have utilized single-gene knockout mice and have concentrated on dopamine- and glutamate-related genes. Genes that code for cell support and signaling molecules are also well-represented. There is a large behavioral genetic literature on responsiveness to amphetamines, but a considerably smaller literature focused on genes that influence the development and acceleration of amphetamine use, withdrawal, relapse, and behavioral toxicity. Also missing are genetic investigations into the effects of amphetamines on social behaviors. This information might help to identify at-risk individuals and in the future to develop treatments that take advantage of individualized genetic information.
Also flagged:neurodegenerative diseasespathogenesisParkinson's diseaseparkinHuntington's diseaseAlzheimer's disease
Journal Article2007-11-28No SnippetsMao L, Zabel C, Herrmann M, Nolden T, Mertes F, Magnol L, Chabert C, Hartl D, Herault Y, Delabar JM, Manke T, Himmelbauer H, Klose J.
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Large numbers of protein expression changes are usually observed in mouse models for neurodegenerative diseases, even when only a single gene was mutated in each case. To study the effect of gene dose alterations on the cellular proteome, we carried out a proteomic investigation on murine embryonic stem cells that either overexpressed individual genes or displayed aneuploidy over a genomic region encompassing 14 genes. The number of variant proteins detected per cell line ranged between 70 and 110, and did not correlate with the number of modified genes. In cell lines with single gene mutations, up and down-regulated proteins were always in balance in comparison to parental cell lines regarding number as well as concentration of differentially expressed proteins. In contrast, dose alteration of 14 genes resulted in an unequal number of up and down-regulated proteins, though the balance was kept at the level of protein concentration. We propose that the observed protein changes might partially be explained by a proteomic network response. Hence, we hypothesize the existence of a class of "balancer" proteins within the proteomic network, defined as proteins that buffer or cushion a system, and thus oppose multiple system disturbances. Through database queries and resilience analysis of the protein interaction network, we found that potential balancer proteins are of high cellular abundance, possess a low number of direct interaction partners, and show great allelic variation. Moreover, balancer proteins contribute more heavily to the network entropy, and thus are of high importance in terms of system resilience. We propose that the "elasticity" of the proteomic regulatory network mediated by balancer proteins may compensate for changes that occur under diseased conditions.
Also flagged:Huntingtinamino acidaminopolyglutamineHuntington's diseaseHD
Journal Article2007-11-28✓ 5 SnippetsTartari M, Gissi C, Lo Sardo V, Zuccato C, Picardi E, Pesole G, Cattaneo E.
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…Biological evidence indicates that huntingtin (htt) is beneficial to cells (particularly to brain neurons) and that loss of its neuronal function may contribute to HD.…
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…indicates that huntingtin (htt) is beneficial to…
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…Evolutionary analyses ofhttprimary aa have…
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…of the availablehttprotein homologues from…
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…corresponding to humanhttaa 1-386 (htt1),…
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Huntingtin is a completely soluble 3,144 amino acid (aa) protein characterized by the presence of an amino-terminal polymorphic polyglutamine (polyQ) tract, whose aberrant expansion causes the progressively neurodegenerative Huntington's disease (HD). Biological evidence indicates that huntingtin (htt) is beneficial to cells (particularly to brain neurons) and that loss of its neuronal function may contribute to HD. The exact protein domains involved in its neuroprotective function are unknown. Evolutionary analyses of htt primary aa have so far been limited to a few species, but its thorough assessment may help to clarify the functions emerging during evolution. We made an extensive comparative analysis of the available htt protein homologues from different organisms along the metazoan phylogenetic tree and defined the presence of 3 different conservative blocks corresponding to human htt aa 1-386 (htt1), 683-1,586 (htt2), and 2,437-3,078 (htt3), in which HEAT (Huntingtin, Elongator factor3, the regulatory A subunit of protein phosphatase 2A, and TOR1) repeats are well conserved. We also describe the cloning and sequencing of sea urchin htt mRNA, the oldest deuterostome homologue so far available. Multiple alignment shows the first appearance of a primitive polyQ in sea urchin, which predates an ancestral polyQ sequence in a nonchordate environment and defines the polyQ characteristic as being typical of the deuterostome branch. The fact that glutamines have conserved positions in deuterostomes and the polyQ size increases during evolution suggests that the protein has a possibly Q-dependent role. Finally, we report an evident relaxing constraint of the N-terminal block in Ciona and drosophilids that correlates with the absence of polyQ and which may indicate that the N-terminal portion of htt has evolved different functions in Ciona and protostomes.
Also flagged:addictionpsychostimulant dependencepsycho-stimulant dependenceStressFrontal-Limbic Dysfunctionsubstance misuse
Journal Article2007-11-28No SnippetsLi CS, Sinha R.
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This review focuses on neuroimaging studies that examined stress processing and regulation and cognitive inhibitory control in patients with psycho-stimulant addiction. We provide an overview of these studies, summarizing converging evidence and discrepancies as they occur in the literature. We also adopt an analytic perspective and dissect these psychological processes into their sub-components, to identify the neural pathways specific to each component process and those that are more specifically involved in psycho-stimulant addiction. To this aim we refer frequently to studies conducted in healthy individuals. Despite the separate treatment of stress/affect regulation, stress-related craving or compulsive drug seeking, and inhibitory control, neural underpinnings of these processes overlap significantly. In particular, the ventromedial prefrontal regions including the anterior cingulate cortex, amygdala and the striatum are implicated in psychostimulant dependence. Our overarching thesis is that prefrontal activity ensures intact emotional stress regulation and inhibitory control. Altered prefrontal activity along with heightened striatal responses to addicted drug and drug-related salient stimuli perpetuates habitual drug seeking. Further studies that examine the functional relationships of these neural systems will likely provide the key to understanding the mechanisms underlying compulsive drug use behaviors in psycho-stimulant dependence.
Also flagged:Alpha-synucleingene expressionPDneurological disorderα-synucleinα-syn
Journal Article2007-11-28No SnippetsYacoubian TA, Cantuti-Castelvetri I, Bouzou B, Asteris G, McLean PJ, Hyman BT, Standaert DG.
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Alpha-synuclein has been implicated in Parkinson disease, yet the mechanism by which alpha-synuclein causes cell injury is not understood. Using a transgenic mouse model, we evaluated the effect of alpha-synuclein overexpression on gene expression in the substantia nigra. Nigral mRNA from wild type and alpha-synuclein transgenic mice was analyzed using Affymetrix gene arrays. At 3 months, before pathological changes are apparent, we observed modest alterations in gene expression. However, nearly 200 genes were altered in expression at 9 months, when degenerative changes are more apparent. Functional genomic analysis revealed that the genes altered at 9 months were predominantly involved in gene transcription. As in human Parkinson disease, gene expression changes in the transgenic model were also modulated by gender. These data demonstrate that alterations of gene expression are widespread in this animal model, and suggest that transcriptional dysregulation may be a disease mechanism that can be targeted therapeutically.
Also flagged:Desferrioxaminebindingpeptidelysinephenylalaninedicarboxylic acid
Journal Article2007-11-27✓ 1 SnippetYe Y, Bloch S, Xu B, Achilefu S.
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Desferrioxamine (DFO), a siderophore initially isolated from Streptomyces pilosus, possesses extraordinary metal binding properties with wide biomedical applications that include chelation therapy, nuclear imaging, and antiproliferation. In this work, we prepared a novel multifunctional agent consisting of (i) a near-infrared (NIR) fluorescent probe-cypate; (ii) an integrin alpha vbeta3 receptor (ABIR)-avid cyclic RGD peptide, and (iii) a DFO moiety, DFO-cypate-cyclo[RGDfK(approximately)] (1, with approximately representing the cypate conjugation site at the side chain of lysine; f is d-phenylalanine). Compound 1 and two control compounds, cypate-cyclo[RGDfK(approximately)] ( 2) and cypate-DFO ( 3), were synthesized by modular assembly of the corresponding protected RGD peptide cyclo[R(Pbf)GD(OBut)fK] and DFO on the dicarboxylic acid-containing cypate scaffold in solution. The three compounds exhibited similar UV-vis and emission spectral properties. Metal binding analysis shows that DFO as well as 1 and 3 exhibited relatively high binding affinity with Fe(III), Al(III), and Ga(III). In contrast to Ga(III), the binding of Fe to 1 and 3 quenched the fluorescence emission of cypate significantly, suggesting an efficient metal-mediated approach to perturb the spectral properties of NIR fluorescent carbocyanine probes. In vitro, 1 showed a high ABIR binding affinity (10 (-7) M) comparable to that of 2 and the reference peptide cyclo(RGDfV), indicating that both DFO and cypate motifs did not interfere significantly with the molecular recognition of the cyclic RGD motif with ABIR. Fluorescence microscopy showed that internalization of 1 and 2 in ABIR-positive A549 cells at 1 h postincubation was higher than 3 and cypate alone, demonstrating that incorporating ABIR-targeting RGD motif could improve cellular internalization of DFO analogues. The ensemble of these findings demonstrate the use of multifunctional NIR fluorescent ABIR-targeting DFO analogues to modulate the spectral properties of the NIR fluorescent probe by the chelating properties of DFO and visualize intracellular delivery of DFO by receptor-specific peptides. These features provide a strategy to explore the potential of 1 in tumor imaging and treatment as well as some molecular recognition processes mediated by metal ions.
<h4>Background</h4>The molecular events underlying mammary development during pregnancy, lactation, and involution are incompletely understood.<h4>Results</h4>Mammary gland microarray data, cellular localization data, protein-protein interactions, and literature-mined genes were integrated and analyzed using statistics, principal component analysis, gene ontology analysis, pathway analysis, and network analysis to identify global biological principles that govern molecular events during pregnancy, lactation, and involution.<h4>Conclusion</h4>Several key principles were derived: (1) nearly a third of the transcriptome fluctuates to build, run, and disassemble the lactation apparatus; (2) genes encoding the secretory machinery are transcribed prior to lactation; (3) the diversity of the endogenous portion of the milk proteome is derived from fewer than 100 transcripts; (4) while some genes are differentially transcribed near the onset of lactation, the lactation switch is primarily post-transcriptionally mediated; (5) the secretion of materials during lactation occurs not by up-regulation of novel genomic functions, but by widespread transcriptional suppression of functions such as protein degradation and cell-environment communication; (6) the involution switch is primarily transcriptionally mediated; and (7) during early involution, the transcriptional state is partially reverted to the pre-lactation state. A new hypothesis for secretory diminution is suggested - milk production gradually declines because the secretory machinery is not transcriptionally replenished. A comprehensive network of protein interactions during lactation is assembled and new regulatory gene targets are identified. Less than one fifth of the transcriptionally regulated nodes in this lactation network have been previously explored in the context of lactation. Implications for future research in mammary and cancer biology are discussed.
Also flagged:hepatocellular carcinomahepatitis C virus infectionCancerdeathaflatoxinalcohol
Journal Article2007-11-27✓ 1 SnippetLehman EM, Soliman AS, Ismail K, Hablas A, Seifeldin IA, Ramadan M, El-Hamzawy H, Shoushtari CS, Wilson ML.
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<h4>Aim</h4>Hepatocellular carcinoma (HCC) is increasing worldwide, and is frequently attributed to rising rates of hepatitis C virus infection and interactions between viral and environmental risk factors. Because of Egypt's unique risk factor profile, we analyzed data from the Gharbiah Population-Based Cancer Registry for the period 1999-2003 to characterize demographic and geographic patterns of cases in this province.<h4>Methods</h4>We calculated age- and sex-specific and age- and sex-standardized HCC incidence rates for the eight districts in Gharbiah. We also compared rates from Gharbiah with the USA (US Surveillance Epidemiology and End RESULTS [SEER] database).<h4>Results</h4>The analysis revealed a higher incidence in males than in females, significant geographic variations among districts, and a higher incidence in Gharbiah than that reported by SEER.<h4>Conclusion</h4>The findings of this study document the heterogeneous distribution of HCC at regional and international levels. This population-based registry offers the opportunity for careful representative studies of various etiologies, particularly infectious and/or environmental factors that may contribute to risk.
Also flagged:mineralagingosteoporosisbone formationbone remodelingphosphorus
Journal Article2007-11-26No SnippetsKim KS, Kim GS, Hwang JY, Lee HJ, Park MH, Kim KJ, Jung J, Cha HS, Shin HD, Kang JH, Park EK, Kim TH, Hong JM, Koh JM, Oh B, Kimm K, Kim SY, Lee JY.
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<h4>Background</h4>Osteoporosis is defined as the loss of bone mineral density that leads to bone fragility with aging. Population-based case-control studies have identified polymorphisms in many candidate genes that have been associated with bone mass maintenance or osteoporotic fracture. To investigate single nucleotide polymorphisms (SNPs) that are associated with osteoporosis, we examined the genetic variation among Koreans by analyzing 81 genes according to their function in bone formation and resorption during bone remodeling.<h4>Methods</h4>We resequenced all the exons, splice junctions and promoter regions of candidate osteoporosis genes using 24 unrelated Korean individuals. Using the common SNPs from our study and the HapMap database, a statistical analysis of deviation in heterozygosity depicted.<h4>Results</h4>We identified 942 variants, including 888 SNPs, 43 insertion/deletion polymorphisms, and 11 microsatellite markers. Of the SNPs, 557 (63%) had been previously identified and 331 (37%) were newly discovered in the Korean population. When compared SNPs in the Korean population with those in HapMap database, 1% (or less) of SNPs in the Japanese and Chinese subpopulations and 20% of those in Caucasian and African subpopulations were significantly differentiated from the Hardy-Weinberg expectations. In addition, an analysis of the genetic diversity showed that there were no significant differences among Korean, Han Chinese and Japanese populations, but African and Caucasian populations were significantly differentiated in selected genes. Nevertheless, in the detailed analysis of genetic properties, the LD and Haplotype block patterns among the five sub-populations were substantially different from one another.<h4>Conclusion</h4>Through the resequencing of 81 osteoporosis candidate genes, 118 unknown SNPs with a minor allele frequency (MAF) > 0.05 were discovered in the Korean population. In addition, using the common SNPs between our study and HapMap, an analysis of genetic diversity and deviation in heterozygosity was performed and the polymorphisms of the above genes among the five populations were substantially differentiated from one another. Further studies of osteoporosis could utilize the polymorphisms identified in our data since they may have important implications for the selection of highly informative SNPs for future association studies.
Also flagged:Histidinenickelcalcium channelCa2+channel
Journal Article2007-11-26No SnippetsKang HW, Moon HJ, Joo SH, Lee JH.
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We recently reported that a histidine (H191) in the S3-S4 loop of domain I is critical for nickel inhibition of the Cav3.2 T-type Ca2+ channel. As in Cav3.2, two histidine residues are commonly found in the IS3-IS4 loops of mammalian Cav2.3 Ca2+ channels, which are also blocked by low micromolar concentrations of nickel. We show here by site-directed mutagenesis and electrophysiology that both residues contribute to the nickel sensitivity of Cav2.3, with H183 being more critical than H179. These findings strongly suggest that both H179 and H183 in the IS3-IS4 loop are essential structural determinants required for nickel sensitive inhibition of the Cav2.3.
Also flagged:CALMAF10localizationIkarosacute lymphoblastic leukemiaacute myeloid leukemia
Journal Article2007-11-26✓ 1 SnippetGreif PA, Tizazu B, Krause A, Kremmer E, Bohlander SK.
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…These results suggest that CALM/AF10 might interfere with normal Ikaros function, and thereby block lymphoid differentiation in CALM/AF10 positive leukemias.…
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The t(10;11)(p13;q14) translocation leads to the fusion of the CALM and AF10 genes. This translocation can be found as the sole cytogenetic abnormality in acute lymphoblastic leukemia, acute myeloid leukemia and in malignant lymphomas. The expression of CALM/AF10 in primary murine bone marrow cells results in the development of an aggressive leukemia in a murine bone marrow transplantation model. Using a yeast two-hybrid screen, we identified the lymphoid regulator Ikaros as an AF10 interacting protein. Interestingly, Ikaros is required for normal development of lymphocytes, and aberrant expression of Ikaros has been found in leukemia. In a murine model, the expression of a dominant negative isoform of Ikaros causes leukemias and lymphomas. The Ikaros interaction domain of AF10 was mapped to the leucine zipper domain of AF10, which is required for malignant transformation both by the CALM/AF10 and the MLL/AF10 fusion proteins. The interaction between AF10 and Ikaros was confirmed by GST pull down and co-immunoprecipitation. Coexpression of CALM/AF10 but not of AF10 alters the subcellular localization of Ikaros in murine fibroblasts. The transcriptional repressor activity of Ikaros is reduced by AF10. These results suggest that CALM/AF10 might interfere with normal Ikaros function, and thereby block lymphoid differentiation in CALM/AF10 positive leukemias.
Also flagged:mitochondrialoriginsdeoxyribonucleoside monophosphateAfrican sleeping sicknessChagas diseaseleishmaniasis
Journal Article2007-11-26No SnippetsHines JC, Ray DS.
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Kinetoplast DNA (kDNA) is a novel form of mitochondrial DNA consisting of thousands of interlocked minicircles and 20-30 maxicircles. The minicircles replicate free of the kDNA network but nicks and gaps in the newly synthesized strands remain at the time of reattachment to the kDNA network. We show here that the steady-state population of replicated, network-associated minicircles only becomes repaired to the point of having nicks with a 3'OH and 5'deoxyribonucleoside monophosphate during S phase. These nicks represent the origin/terminus of the strand and occur within the replication origins (oriA and oriB) located 180 degrees apart on the minicircle. Minicircles containing a new L strand have a single nick within either oriA or oriB but not in both origins in the same molecule. The discontinuously synthesized H strand contains single nicks within both oriA and oriB in the same molecule implying that discontinuities between the H-strand Okazaki fragments become repaired except for the fragments initiated within the two origins. Nicks in L and H strands at the origins persist throughout S phase and only become ligated as a prelude to network division. The failure to ligate these nicks until just prior to network division is not due to inappropriate termini for ligation.
Also flagged:surface layer protein A-AP-BRestriction EndonucleaseAslpA
Journal Article2007-11-26No SnippetsKillgore G, Thompson A, Johnson S, Brazier J, Kuijper E, Pepin J, Frost EH, Savelkoul P, Nicholson B, van den Berg RJ, Kato H, Sambol SP, Zukowski W, Woods C, Limbago B, Gerding DN, McDonald LC.
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Using 42 isolates contributed by laboratories in Canada, The Netherlands, the United Kingdom, and the United States, we compared the results of analyses done with seven Clostridium difficile typing techniques: multilocus variable-number tandem-repeat analysis (MLVA), amplified fragment length polymorphism (AFLP), surface layer protein A gene sequence typing (slpAST), PCR-ribotyping, restriction endonuclease analysis (REA), multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). We assessed the discriminating ability and typeability of each technique as well as the agreement among techniques in grouping isolates by allele profile A (AP-A) through AP-F, which are defined by toxinotype, the presence of the binary toxin gene, and deletion in the tcdC gene. We found that all isolates were typeable by all techniques and that discrimination index scores for the techniques tested ranged from 0.964 to 0.631 in the following order: MLVA, REA, PFGE, slpAST, PCR-ribotyping, MLST, and AFLP. All the techniques were able to distinguish the current epidemic strain of C. difficile (BI/027/NAP1) from other strains. All of the techniques showed multiple types for AP-A (toxinotype 0, binary toxin negative, and no tcdC gene deletion). REA, slpAST, MLST, and PCR-ribotyping all included AP-B (toxinotype III, binary toxin positive, and an 18-bp deletion in tcdC) in a single group that excluded other APs. PFGE, AFLP, and MLVA grouped two, one, and two different non-AP-B isolates, respectively, with their AP-B isolates. All techniques appear to be capable of detecting outbreak strains, but only REA and MLVA showed sufficient discrimination to distinguish strains from different outbreaks.
Also flagged:histonehistone chaperoneANP32Bchromatinhistone-modifyingnucleosome
Journal Article2007-11-26✓ 1 SnippetMunemasa Y, Suzuki T, Aizawa K, Miyamoto S, Imai Y, Matsumura T, Horikoshi M, Nagai R.
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Regulation of chromatin in eukaryotic transcription requires histone-modifying enzymes, nucleosome remodeling complexes, and histone chaperones. Specific regulation of histone incorporation/eviction by histone chaperones on the promoter (e.g., region specific) is still poorly understood. In the present study, we show that direct and functional interaction of histone chaperone and DNA-binding transcription factor leads to promoter region-specific histone incorporation and inhibition of histone acetylation. We report here that the DNA-binding transcription factor Krüppel-like factor 5 (KLF5) interacts with the novel histone chaperone acidic nuclear phosphoprotein 32B (ANP32B), leading to transcriptional repression of a KLF5-downstream gene. We further show that recruitment of ANP32B onto the promoter region requires KLF5 and results in promoter region-specific histone incorporation and inhibition of histone acetylation by ANP32B. Extracellular stimulus (e.g., phorbol ester) regulates this mechanism in the cell. Collectively, we have identified a novel histone chaperone, ANP32B, and through analysis of the actions of this factor show a new mechanism of promoter region-specific transcriptional regulation at the chromatin level as mediated by the functional interaction between histone chaperone and DNA-binding transcription factor.
Also flagged:hereditary hemochromatosisleucineprolineTfR1iron
Journal Article2007-11-26✓ 5 SnippetsSwinkels DW, Venselaar H, Wiegerinck ET, Bakker E, Joosten I, Jaspers CA, Vasmel WL, Breuning MH.
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…We describe a novel heterozygous mutation in exon 3 of the HFE-gene that was co-inherited with Cys282Tyr in two unrelated Dutch men both presenting a classical form of hereditary hemochromatosis.…
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…This c.548T>C mutation converts a leucine to a proline residue at position 183 in the alpha2-helix of the HFE-protein (Leu183Pro).…
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…(Leu183Pro-)mutation in theHFE-gene co-inherited with the…
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…two unrelated Dutchhemochromatosispatients.…
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…3 of theHFE-gene that was co-inherited…
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We describe a novel heterozygous mutation in exon 3 of the HFE-gene that was co-inherited with Cys282Tyr in two unrelated Dutch men both presenting a classical form of hereditary hemochromatosis. Heterozygosity for this mutation was also found in one out of 100 healthy controls of Dutch descent. This c.548T>C mutation converts a leucine to a proline residue at position 183 in the alpha2-helix of the HFE-protein (Leu183Pro). Standard bioinformatics analysis shows that the mutation is likely to disturb the HFE interaction with TfR1. This disrupting role of the mutation in the iron regulatory pathway is further corroborated by the familial co-occurrence of the observed compound heterozygosity with increased serum iron parameters. Haplotype analysis strongly suggests that this novel mutation arose from a common ancestor in the distant past. These findings may have implications for HFE-testing of iron overloaded heterozygous Cys282Tyr-patients of Northern European origin and their relatives.
Also flagged:lithiumlithium saltsbipolar disorderspersonality disordersbipolar type I disordersrapid
Journal Article2007-11-26✓ 2 SnippetsRohayem J, Baylé JF, Richa S.
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…Genetic predictors of negative prophylactic lithium response include the homozygotic forms of the short allele of the serotonin transporter gene (5-HTT), the presence of the A/A subtype of tryptophan hydroxylase (TPH) gene and a high frequency of human leukocyte antigens type A3 (HLA-A3), this genotype being associated with cellular membrane anomalies implicated in alteration of lithium intracellular transport.<h4>Discussion</h4>The search for new predictors of lithium prophylactic response is currently facing several methodological problems: lack of representativity of the samples of bipolar patients enrolled in research studies, poor reliability of retrospective reconstructions of the course of the bipolar disorder before initiation of lithium treatment, absence of consensus on tools used to assess response to lithium prophylaxis in study designs, difficult access and high costs of most of the laboratory and neuroimaging techniques used in recent studies such as magnetic resonance spectroscopy and LDAEP measures, and problematic evaluation of the impact of treatment on a disorder whose natural intrinsic course is often irregular.…
Abstract)
…serotonin transporter gene (5-HTT), the presence of…
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<h4>Introduction</h4>Since their first utilization in psychiatry as mood stabilizers in the 1940s, lithium salts have been widely studied in the medical literature. The considerable amount of data available to date, supports the use of lithium salts as first-line mood stabilizing agents, with acute antimanic and antidepressant properties and proven efficacy in the long term prevention of manic and depressive relapses.<h4>Literature findings</h4>Several predictors were reported by different authors in early articles and were confirmed later on by the medical literature. All the psychopathological, environmental, biological, neurophysiologic and genetic predictors known to date are reviewed here. PSYCHOLOGICAL PREDICTORS: Psychopathological predictors of a good response to lithium prophylaxis include: the initial good response to lithium during the first 6-12 months of treatment, considered to date to be the most reliable predictor of a favourable response to lithium; the classical pattern of elated manic episodes; a positive familial history of bipolar disorders, especially those known to be responsive to lithium; the absence of comorbid personality disorders; bipolar type I disorders; melancholic features during depressive episodes; MDI pattern in the illness course and early onset of lithium treatment. In contrast, the following have been confirmed as psychopathological predictors of poor prophylactic lithium response: mixed episodes, considered to be one of the most reliable predictors of poor response to lithium since Kraeplin's description; rapid cycling bipolar disorders; comorbid alcohol and/or drug abuse; mood disorders with incongruent psychotic features; early onset bipolar disorder before the age of 18; discontinuation of lithium treatment; high number of previous affective episodes in the illness course before lithium initiation and DMI pattern. ENVIRONMENTAL PREDICTORS: Among environmental factors, being single was found to be the only predictor of a poor response to lithium treatment in prophylaxis. BIOLOGICAL PREDICTORS: Biological predictors of a good prophylactic response to lithium include a high RBC/plasma-lithium ratio, one of the most controversial predictors of a favourable response to lithium in the literature, a higher platelet serotonin-induced calcium mobilization, and a high rate of red blood cell membrane phospholipids, especially of phosphatidylcholine, and a phospholipid implicated in lithium intracellular transport. Among neurophysiologic predictors of a favourable response to lithium, the following have been reported: brain lithium concentrations above 0.2 mEq/L when measured by 7Li-MRS; decreased cerebral intracellular pH and white matter hyper intensity at (31)P-MRS and a high intensity of loudness dependence auditory-evoked potentials (LDAEP), the latter being one of the best indicators of human cerebral serotoninergic functioning. In contrast, the following have been reported as neurophysiological predictors of a poor lithium response in prophylaxis: epileptiform anomalies with diffuse theta waves on electroencephalography, a predictor of poor response to lithium known since the descriptions of Dalen in 1965 and decreased cerebral phosphocreatine levels at (31)P-MRS, the latter being an indicator of cerebral mitochondrial dysfunction. GENETIC PREDICTORS: Genetic predictors of good response to lithium in prophylaxis include a lower-inositol-monophosphatase (IMPase-2) mRNA expression, IMPase-2 being a key enzyme of the calcium-intracellular-signalling pathway and IMPase-2 gene being studied recently as a candidate gene in bipolar disorder. A higher frequency of phospholipase C isoenzyme gamma1 (PLCG1)-5 repeat allele genes has also been associated with a good response to lithium, PLCG1 being a major enzyme of the phosphatidylinositol second messenger system. Genetic predictors of negative prophylactic lithium response include the homozygotic forms of the short allele of the serotonin transporter gene (5-HTT), the presence of the A/A subtype of tryptophan hydroxylase (TPH) gene and a high frequency of human leukocyte antigens type A3 (HLA-A3), this genotype being associated with cellular membrane anomalies implicated in alteration of lithium intracellular transport.<h4>Discussion</h4>The search for new predictors of lithium prophylactic response is currently facing several methodological problems: lack of representativity of the samples of bipolar patients enrolled in research studies, poor reliability of retrospective reconstructions of the course of the bipolar disorder before initiation of lithium treatment, absence of consensus on tools used to assess response to lithium prophylaxis in study designs, difficult access and high costs of most of the laboratory and neuroimaging techniques used in recent studies such as magnetic resonance spectroscopy and LDAEP measures, and problematic evaluation of the impact of treatment on a disorder whose natural intrinsic course is often irregular.
Also flagged:Dexamethasoneleptinserotonin5-hydroxytryptaminehydroxyindole-acetic acid
Journal Article2007-11-24✓ 4 SnippetsJahng JW, Kim NY, Ryu V, Yoo SB, Kim BT, Kang DW, Lee JH.
In-Text Gene Mentions
Abstract)
…Food intake and weight gain were recorded, and plasma leptin, brain contents of serotonin (5-hydroxytryptamine; 5-HT), 5-hydroxy-indole-acetic acid (5-HIAA) and the raphe expression of tryptophan hydroxylase (TPH), monoamine oxidase A (MAO-A) and 5-HT reuptake transporter (5-HTT) genes were examined.…
Abstract)
…5-HT reuptake transporter (5-HTT) genes were examined.…
Abstract)
…TPH, MAO-A and5-HTTgenes, but repeated…
Abstract)
…of MAO-A and5-HTTgenes by repeated…
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This study was conducted to define the regulatory mechanisms underlying stress-induced decreases in food intake and weight gain. Rats received a single or 4 daily injections of dexamethasone (0.1 or 1 mg/kg). Food intake and weight gain were recorded, and plasma leptin, brain contents of serotonin (5-hydroxytryptamine; 5-HT), 5-hydroxy-indole-acetic acid (5-HIAA) and the raphe expression of tryptophan hydroxylase (TPH), monoamine oxidase A (MAO-A) and 5-HT reuptake transporter (5-HTT) genes were examined. A single injection of dexamethasone did not acutely affect food intake, but cumulative food intake and weight gain were suppressed dose-dependently by daily injections of dexamethasone. Both a single and repeated injections of dexamethasone elevated plasma leptin in a dose dependent manner. 5-HT contents in the hypothalamus was decreased, but 5-HIAA increased, both by a single and repeated dexamethasone. A single injection of dexamethasone did not affect mRNA expressions of TPH, MAO-A and 5-HTT genes, but repeated dexamethasone increased them in the dorsal raphe nucleus. These results suggest that plasma leptin may play a role in dexamethasone-induced anorexia. Additionally, increased expression of MAO-A and 5-HTT genes by repeated dexamethasone appears to be implicated in decreases of the brain 5-HT contents.
Also flagged:hereditary hemochromatosisgenetic diseaseironHHiron overload diseasemetabolism
Journal Article2007-11-23✓ 5 SnippetsCukjati M, Vaupotic T, Rupreht R, Curin-Serbec V.
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Abstract)
…Although the most prevalent genotype in HH is homozygosity for C282Y mutation of the HFE gene, two additional mutations, H63D and S65C, appear to be associated with a milder form of HH.…
Introduction)
…The majority of HH cases (52–96%) in European regions are associated with a homozygous 845G→A mutation within exon 4 of the HFE gene, which results in amino acid change at position 282 from cysteine to tyrosine (C282Y) [1,2].…
<h4>Background</h4>Hereditary hemochromatosis (HH) is a common genetic disease characterized by excessive iron overload that leads to multi-organ failure. Although the most prevalent genotype in HH is homozygosity for C282Y mutation of the HFE gene, two additional mutations, H63D and S65C, appear to be associated with a milder form of HH. The aim of this study was to develop a high-throughput assay for HFE mutations screening based on TaqMan technology and to determine the frequencies of HFE mutations in the Slovenian population.<h4>Methods</h4>Altogether, 1282 randomly selected blood donors from different Slovenian regions and 21 HH patients were analyzed for the presence of HFE mutations by an in-house developed real-time PCR assay based on TaqMan technology using shorter non-interfering fluorescent single nucleotide polymorphism (SNP)-specific MGB probes. The assay was validated by RFLP analysis and DNA sequencing.<h4>Results</h4>The genotyping assay of the H63D, S65C and C282Y mutations in the HFE gene, based on TaqMan technology proved to be fast, reliable, with a high-throughput capability and 100% concordant with genotypes obtained by RFLP and DNA sequencing. The observed frequency of C282Y homozygotes in the group of HH patients was only 48%, others were of the heterogeneous HFE genotype. Among 1282 blood donors tested, the observed H63D, S65C and C282Y allele frequency were 12.8% (95% confidence interval (CI) 11.5-14.2%), 1.8% (95% CI 1.4-2.5%) and 3.6% (95% CI 3.0-4.5%), respectively. Approximately 33% of the tested subjects had at least one of the three HH mutations, and 1% of them were C282Y homozygotes or compound heterozygotes C282Y/H63D or C282Y/S65C, presenting an increased risk for iron overload disease. A significant variation in H63D allele frequency was observed for one of the Slovenian regions.<h4>Conclusion</h4>The improved real-time PCR assay for H63D, S65C and C282Y mutations detection is accurate, fast, cost-efficient and ready for routine screening and diagnostic procedures. The genotype frequencies in the Slovenian population agree with those reported for the Central European populations although some deviations where observed in comparison with other populations of Slavic origin. Regional distribution of the mutations should be considered when planning population screening.
RNA chaperone proteins are essential partners of RNA in living organisms and viruses. They are thought to assist in the correct folding and structural rearrangements of RNA molecules by resolving misfolded RNA species in an ATP-independent manner. RNA chaperoning is probably an entropy-driven process, mediated by the coupled binding and folding of intrinsically disordered protein regions and the kinetically trapped RNA. Previously, we have shown that the core protein of hepatitis C virus (HCV) is a potent RNA chaperone that can drive profound structural modifications of HCV RNA in vitro. We now examined the RNA chaperone activity and the disordered nature of core proteins from different Flaviviridae genera, namely that of HCV, GBV-B (GB virus B), WNV (West Nile virus) and BVDV (bovine viral diarrhoea virus). Despite low-sequence similarities, all four proteins demonstrated general nucleic acid annealing and RNA chaperone activities. Furthermore, heat resistance of core proteins, as well as far-UV circular dichroism spectroscopy suggested that a well-defined 3D protein structure is not necessary for core-induced RNA structural rearrangements. These data provide evidence that RNA chaperoning-possibly mediated by intrinsically disordered protein segments-is conserved in Flaviviridae core proteins. Thus, besides nucleocapsid formation, core proteins may function in RNA structural rearrangements taking place during virus replication.
Also flagged:glucoseHuntington's diseaseHDdiabetes mellitusdiabetesimpaired
Journal Article2007-11-22✓ 1 SnippetJosefsen K, Nielsen MD, Jørgensen KH, Bock T, Nørremølle A, Sørensen SA, Naver B, Hasholt L.
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Abstract)
…gene product, huntingtin (htt), in both alpha-…
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Previous reports have highlighted a possible link between Huntington's disease (HD) and diabetes mellitus (DM), but the association has not been characterised in detail. A transgenic mouse model for HD, the R6/2 mouse, also develops diabetes. In the present study, we examined the R6/1 mouse, which carries a shorter CAG repeat than the R6/2 mouse, and found that, although not diabetic, the mice showed several signs of impaired glucose tolerance. First, following i.p. glucose injection, the blood glucose concentration was approximately 30% higher in young R6/1 mice (10 weeks) compared to wild-type mice (P = 0.004). In older mice (38 weeks), glucose tolerance was further impaired in both R6/1 and wild-type animals. Second, during glucose challenge, the R6/1 mice reached higher plasma insulin levels than wild-type mice, but the peripheral insulin sensitivity was normal as measured by injection of human or mouse insulin or when evaluated by the quantitative insulin sensitivity check index (QUICKI). Third, the beta cell volume was 17% and 39% smaller at 10 and 38 weeks of age, respectively, compared to age-matched wild-type littermates and the reduction was not caused by apoptosis at either age. Finally, we demonstrated the presence of the HD gene product, huntingtin (htt), in both alpha- and beta-cells in R6/1 islets of Langerhans. Since pancreatic beta cells and neurons share several common traits, clarification of the mechanism associating neurodegenerative diseases with diabetes might improve our understanding of the pathogenic events leading to both groups of diseases.
Also flagged:HIP1genetic neurological disorderHuntingtin-interacting protein 1HIPPIHIPprotein
Journal Article2007-11-22✓ 4 SnippetsNiu Q, Ybe JA.
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Abstract)
…Huntington's disease is a genetic neurological disorder that is triggered by the dissociation of the huntingtin protein (htt) from its obligate interaction partner Huntingtin-interacting protein 1 (HIP1).…
Abstract)
…the huntingtin protein (htt) from its obligate…
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…The release ofhttpermits HIP-protein interactor…
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…htt…
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Huntington's disease is a genetic neurological disorder that is triggered by the dissociation of the huntingtin protein (htt) from its obligate interaction partner Huntingtin-interacting protein 1 (HIP1). The release of the huntingtin protein permits HIP1 protein interactor (HIPPI) to bind to its recognition site on HIP1 to form a HIPPI/HIP1 complex that recruits procaspase-8 to begin the process of apoptosis. The interaction module between HIPPI and HIP1 was predicted to resemble a death-effector domain. Our 2.8-A crystal structure of the HIP1 371-481 subfragment that includes F432 and K474, which is important for HIPPI binding, is not a death-effector domain but is a partially opened coiled coil. The HIP1 371-481 model reveals a basic surface that we hypothesize to be suitable for binding HIPPI. There is an opened region next to the putative HIPPI site that is highly negatively charged. The acidic residues in this region are highly conserved in HIP1 and a related protein, HIP1R, from different organisms but are not conserved in the yeast homologue of HIP1, sla2p. We have modeled approximately 85% of the coiled-coil domain by joining our new HIP1 371-481 structure to the HIP1 482-586 model (Protein Data Bank code: 2NO2). Finally, the middle of this coiled-coil domain may be intrinsically flexible and suggests a new interaction model where HIPPI binds to a U-shaped HIP1 molecule.
Also flagged:non-small cell lung cancerepidermal growth factor receptorNSCLCEGFRtyrosine kinasegene expression
Journal Article2007-11-21✓ 1 SnippetChoi K, Creighton CJ, Stivers D, Fujimoto N, Kurie JM.
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…MYLK, STK39, ACVR1,TAOK3, and IFIH1 ),…
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<h4>Background</h4>Activating somatic mutations in epidermal growth factor receptor (EGFR) confer unique biologic features to non-small cell lung cancer (NSCLC) cells, but the transcriptional mediators of EGFR in this subgroup of NSCLC have not been fully elucidated.<h4>Methodology/principal findings</h4>Here we used genetic and pharmacologic approaches to elucidate the transcriptomes of NSCLC cell lines. We transcriptionally profiled a panel of EGFR-mutant and -wild-type NSCLC cell lines cultured in the presence or absence of an EGFR tyrosine kinase inhibitor. Hierarchical analysis revealed that the cell lines segregated on the basis of EGFR mutational status (mutant versus wild-type), and expression signatures were identified by supervised analysis that distinguished the cell lines based on mutational status (wild-type versus mutant) and type of mutation (L858R versus Delta746-750). Using an EGFR mutation-specific expression signature as a probe, we mined the gene expression profiles of two independent cohorts of NSCLC patients and found the signature in a subset. EGFR tyrosine kinase inhibitor treatment regulated the expression of multiple genes, and pharmacologic inhibition of the protein products of two of them (PTGS2 and EphA2) inhibited anchorage-independent growth in EGFR-mutant NSCLC cells.<h4>Conclusions/significance</h4>We have elucidated genes not previously associated with EGFR-mutant NSCLC, two of which enhanced the clonogenicity of these cells, distinguishing these mediators from others previously shown to maintain cell survival. These findings have potential clinical relevance given the availability of pharmacologic tools to inhibit the protein products of these genes.
Also flagged:Cysteine sulfenic acidcysteinehydrogenthiol1,3-cyclohexadionealcohol
Journal Article2007-11-21No SnippetsPoole LB, Klomsiri C, Knaggs SA, Furdui CM, Nelson KJ, Thomas MJ, Fetrow JS, Daniel LW, King SB.
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Cysteine sulfenic acid formation in proteins results from the oxidative modification of susceptible cysteine residues by hydrogen peroxide, alkyl hydroperoxides, and peroxynitrite. This species represents a biologically significant modification occurring during oxidant signaling or oxidative stress, and it can modulate protein function. Most methods to identify such oxidatively modified proteins rely on monitoring the loss of one or more thiol group(s) or on selective labeling of nascent thiol groups following reduction of oxidized proteins. Our previous work reported the direct labeling of these chemically distinct modifications with a dimedone analogue, 1,3-cyclohexadione, to which a linker and functional group (an alcohol) had been added; further addition of a fluorescent isatoic acid or methoxycoumarin reporter allowed detection of the incorporated tag by fluorescence techniques ( Poole, L. B., Zeng, B. B., Knaggs, S. A., Yakubu, M., and King, S. B. ( 2005) Synthesis of chemical probes to map sulfenic acid modifications on proteins. Bioconjugate Chem . 16, 1624-1628 ). We have now expanded our arsenal of tagging reagents to include two fluorescein-, two rhodamine-, and three biotin-conjugated probes based on the original approach. The new tools provide readily detectable fluorescent and affinity probes to identify sulfenic acid modifications in proteins and have been used in subsequent mass spectrometric analyses to confirm covalent attachment of the conjugates and directly determine the site of modification.
Also flagged:phthalocyanineoligonucleotideWatermetallopthalocyanineconjugation
Journal Article2007-11-21No SnippetsNesterova IV, Verdree VT, Pakhomov S, Strickler KL, Allen MW, Hammer RP, Soper SA.
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Water soluble, metallo-pthalocyanine (MPc) near-IR fluorophores were designed, synthesized, and evaluated as highly stable and sensitive reporters for fluorescence assays. Their conjugation to oligonucleotides was achieved via succinimidyl ester-amino coupling chemistry with the conditions for conjugation extensively examined and optimized. In addition, various conjugate purification and isolation techniques were evaluated as well. Results showed that under proper conditions and following purification using reverse-phase ion-pair chromatography, labeling efficiencies near 80% could be achieved using ZnPc (Zn phthalocyanine) as the labeling fluorophore. Absorption and fluorescence spectra accumulated for the conjugates indicated that the intrinsic fluorescence properties of the MPc's were not significantly altered by covalent attachment to oligonucleotides. As an example of the utility of MPc reporters, we used the MPc-oligonucleotide conjugates as primers for PCR (polymerase chain reaction) amplifications with the products sorted via electrophoresis and detected using near-IR fluorescence (lambda ex = 680 nm). The MPc dyes were found to be more chemically stable under typical thermal cycling conditions used for PCR compared to the carbocyanine-based near-IR reporter systems typically used and produced single and narrow bands in the electrophoretic traces, indicative of producing a single PCR product during amplification.
Also flagged:progesterone receptorDickkopftissue remodelingMenstruationprogesteronePR
Journal Article2007-11-21No SnippetsKane N, Jones M, Brosens JJ, Saunders PT, Kelly RW, Critchley HO.
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TGFbeta1 is thought to be intimately involved in cyclic tissue remodeling and inflammatory events associated with menstruation. Menstruation is initiated by progesterone withdrawal; however, the underlying mechanisms are not well understood. In the present study, we have tested the hypothesis that locally produced TGFbeta1 may influence expression of progesterone receptor (PR) or the Wnt antagonist Dickkopf-1 (DKK) with consequential impact on regulation of menstruation. Endometrial stromal cells (ESC) were isolated from endometrial biopsy samples collected from patients undergoing gynecological procedures for benign indications. Treatment of differentiated ESC with TGFbeta1 (10 ng/ml) significantly inhibited the expression of mRNAs encoding PR and DKK. TGFbeta1 also attenuated the protein expression of PR and secretion of DKK proteins in culture supernatants. Neutralization of endogenous TGFbeta1 signaling abolished the TGFbeta1-induced effects, significantly increased expression of PR, and increased DKK protein release levels to that of differentiated ESCs, confirming the specificity of the TGFbeta1 effect. Additionally, in vitro decidualization of ESCs significantly augmented DKK protein release. Moreover, although TGFbeta1 was capable of signaling via the Sma- and mothers against decapentaplegic (MAD)-related protein (SMAD) pathway, the inhibitory effect on DKK was SMAD independent. Conversely, the inhibitory effect of TGFbeta1 on PR was dependent on SMAD signal transduction. In conclusion, these results suggest that local TGFbeta1 signaling can potentiate progesterone withdrawal by suppressing expression of PR and may coordinate tissue remodeling associated with menstruation by inducing Wnt-signaling via inhibition of DKK, which we found to be up-regulated as a consequence of decidualization of ESCs.
Also flagged:Mitogen- and stress-activated protein kinase-1deathHuntington's diseaseHDneurodegenerative disorderExp
Journal Article2007-11-20✓ 5 SnippetsRoze E, Betuing S, Deyts C, Marcon E, Brami-Cherrier K, Pagès C, Humbert S, Mérienne K, Caboche J.
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Abstract)
…Huntington's disease (HD) is a neurodegenerative disorder due to an abnormal polyglutamine expansion in the N-terminal region of huntingtin protein (Exp-Htt).…
Abstract)
…We extended this observation to Exp-Htt-expressing striatal neurons and postmortem brains of HD patients.…
Abstract)
…of huntingtin protein (Exp-Htt).…
Abstract)
…dysregulation due to Exp-Httparticipates in neuronal…
Abstract)
…this observation to Exp-Htt-expressing striatal neurons a…
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Huntington's disease (HD) is a neurodegenerative disorder due to an abnormal polyglutamine expansion in the N-terminal region of huntingtin protein (Exp-Htt). This expansion causes protein aggregation and neuronal dysfunction and death. Transcriptional dysregulation due to Exp-Htt participates in neuronal death in HD. Here, using the R6/2 transgenic mouse model of HD, we identified a new molecular alteration that could account for gene dysregulation in these mice. Despite a nuclear activation of the mitogen-activated protein kinase/extracellular regulated kinase (ERK) along with Elk-1 and cAMP responsive element binding, two transcription factors involved in c-Fos transcription, we failed to detect any histone H3 phosphorylation, which is expected after nuclear ERK activation. Accordingly, we found in the striatum of these mice a deficiency of mitogen- and stress-activated kinase-1 (MSK-1), a kinase downstream ERK, critically involved in H3 phosphorylation and c-Fos induction. We extended this observation to Exp-Htt-expressing striatal neurons and postmortem brains of HD patients. In vitro, knocking out MSK-1 expression potentiated Exp-Htt-induced striatal death. Its overexpression induced H3 phosphorylation and c-Fos expression and totally protected against striatal neurodegeneration induced by Exp-Htt. We propose that MSK-1 deficiency is involved in transcriptional dysregulation and striatal degeneration. Restoration of its expression and activity may be a new therapeutic target in HD.
Also flagged:serotonin transporterdepressionpsychiatric disordersCortisol5Axis I disorder
Journal Article2007-11-19No SnippetsGotlib IH, Joormann J, Minor KL, Hallmayer J.
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<h4>Background</h4>Recent evidence indicates that individuals who are homozygous for the short (s) allele in the promoter region of the serotonin transporter gene have higher rates of depression and other psychiatric disorders as a function of exposure to increasing levels of stressful life events than do individuals who have one or two copies of the long (l) allele. Despite the reliability of this association, the mechanism by which this polymorphism confers risk for psychopathology in the presence of stress is not understood. This study was designed to examine the formulation that individuals who are homozygous for the s allele are characterized by a greater biological reactivity to stress than are their counterparts who have one or two copies of the l allele.<h4>Methods</h4>Girls at high (n = 25) and low (n = 42) risk for depression by virtue of the presence or absence of a family history of this disorder were genotyped and exposed to a standardized laboratory stress task. Cortisol levels were assessed before the stressor, after the stressor, and during an extended recovery period.<h4>Results</h4>Girls who were homozygous for the s allele produced higher and more prolonged levels of cortisol in response to the stressor than did girls with an l allele.<h4>Conclusions</h4>These findings indicate that the 5-HTTLPR polymorphism is associated with biological stress reactivity, which may increase susceptibility to depression in the face of stressful life events.
Also flagged:nucleoluschromosomeorganizationbindingcell divisionpolypeptides
Journal Article2007-11-19✓ 1 SnippetWang BD, Strunnikov A.
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Abstract)
…Condensinactivity establishes and…
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Condensin activity establishes and maintains mitotic chromosome condensation, however the mechanisms of condensin recognition of specific chromosomal sites remain unknown. rDNA is the chief condensin binding locus in Saccharomyces cerevisiae, and the level of nucleolar transcription is one of the key factors determining condensin loading to the nucleolar organizer. A new aspect of this transcriptional control is demonstrated in cells with a diffuse (episomal) nucleolar organizer, where active transcription excludes condensin from the transcribed regions of rDNA. Genome-wide ChIP-chip analysis showed that these cells acquire an altered and a more robust pattern of chromosomal condensin distribution, with increased enrichment of wild-type hotspots and with emergence of new sites, most notably in the subtelomeric regions. This genome-wide condensin relocalization induced by the increase in rDNA transcription and, possibly, nucleolar architecture uncovers a novel potential role of the nucleolus in the general chromosome organization.
…Because the penetrance of HFE hemochromatosis is low, traditional population screening measuring the transferrin saturation is unlikely to be cost-effective because the majority of subjects detected neither have clinical disease nor are likely to develop it.…
Abstract)
…HFE hemochromatosis…
Abstract)
…hemochromatosis study, only 59 had serum ferritin levels more than 1000 microg/L; 24 had homozygous mutant or compound heterozygous mutant HFE…
…the penetrance ofHFE hemochromatosishemochromatosis is low,…
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Because the penetrance of HFE hemochromatosis is low, traditional population screening measuring the transferrin saturation is unlikely to be cost-effective because the majority of subjects detected neither have clinical disease nor are likely to develop it. Three independent studies show that only patients with serum ferritin concentrations more than 1000 microg/L are at risk for cirrhosis, one of the main morbidities of hemochromatosis. Among 29,699 white subjects participating in the Scripps/Kaiser hemochromatosis study, only 59 had serum ferritin levels more than 1000 microg/L; 24 had homozygous mutant or compound heterozygous mutant HFE genotypes. In all but 5 of the other subjects, the causes of elevated ferritin were excessive alcohol intake, cancer, or liver disease. Screening for hemochromatosis with serum ferritin levels will detect the majority of patients who will be clinically affected and may detect other clinically significant disease in patients who do not have hemochromatosis genotypes. Because the ferritin level of the majority of adult homozygotes for HFE mutations does not rise over long periods of time, excluding subjects with serum ferritin levels less than or equal to 1000 microg/L should not result in missed opportunities for early treatment of patients who could benefit.
Also flagged:thalassemia intermediabeta-thalassemiaironbeta-thalassemia intermediathalassemiahemopoiesis
Journal Article2007-11-19✓ 1 SnippetAessopos A, Tsironi M, Polonifi K, Baltopoulos P, Vaiopoulos G.
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Abstract)
…is described inhemochromatosis.…
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<h4>Objectives</h4>Intervertebral disc calcification, an age-related phenomenon of variable clinical significance is described in hemochromatosis. As beta-thalassemia is characterized by excessive tissue iron deposition and secondary hemosiderosis, and skeletal abnormalities are often observed in these patients, this study is conducted to identify the prevalence of Intervertebral Disc Calcification (IDC) in thalassemia intermedia population.<h4>Methods</h4>We investigated all the elder than 30 years beta-thalassemia intermedia patients of our Department thalassemia unit. Patients underwent thoracic and lumbar spinal X-rays for IDC presence. Patients presenting IDC were compared to those not presenting, regarding back pain anamnesis, presence of back pain, extramedullary hemopoiesis, sex, age, Hb levels, ferritin levels, reticulocytes, bilirubin values, thyroid-parathyroid abnormalities. Student's t-test was used to compare variables between patients with and without IDC. A P-value under 0.05 was considered statistically significant.<h4>Results</h4>We investigated 30 beta-thalassemia intermedia patients (19 women) with an age range 38-61 yr (42.5 +/- 11.46 yr). Intervertebral disc calcifications were observed in seven patients (23.33%). No sex and laboratory parameters statistically significant differences were observed differences for IDC prevalence, while mean age and back pain history was statistically significantly different between the two groups.<h4>Conclusions</h4>In thalassemia patients, the big variety of spinal deformities may hide the presence of IDC and thus, this entity may be overlooked or underestimated. The clinical significance of IDC development as well as the possible prevention by early transfusion chelation therapy should be further investigated.
Also flagged:Huntington's diseaseHDautosomal dominant progressive neurodegenerative disordernucleuscytoplasm14-3-3zeta
Journal Article2007-11-17✓ 5 SnippetsOmi K, Hachiya NS, Tanaka M, Tokunaga K, Kaneko K.
In-Text Gene Mentions
Abstract)
…In this study, analysis of the aggregation-prone protein Htt encoded by HD gene exon 1 containing polyglutamine expansions (Htt86Q) revealed that 17 residues in the NH(2)-terminal of this protein are indispensable for its aggregate formation.…
Abstract)
…A hallmark of HD is the presence of aggregates-predominantly composed of NH(2)-terminal fragments of polyQ-expanded Htt-in the nucleus and cytoplasm of affected neurons.…
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…in the huntingtin (Htt) protein.…
Abstract)
…fragments of polyQ-expandedHtt-in the nucleus and…
Abstract)
…the aggregation-prone proteinHttencoded by HD…
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Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disorder caused by polyglutamine (polyQ) expansions in the huntingtin (Htt) protein. A hallmark of HD is the presence of aggregates-predominantly composed of NH(2)-terminal fragments of polyQ-expanded Htt-in the nucleus and cytoplasm of affected neurons. We previously proposed that 14-3-3zeta might act as a sweeper of misfolded proteins by facilitating the formation of aggregates possibly for neuroprotection; these aggregates are referred to as inclusion bodies. However, evidence available in this regard is indirect and circumstantial. In this study, analysis of the aggregation-prone protein Htt encoded by HD gene exon 1 containing polyglutamine expansions (Htt86Q) revealed that 17 residues in the NH(2)-terminal of this protein are indispensable for its aggregate formation. Immunoprecipitation assays revealed that 14-3-3beta, gamma, eta, and zeta interact with Htt86Q transfected in N2a cells. Interestingly, the small interfering ribonucleic acid (siRNA) suppression of 14-3-3zeta exclusively abolished Htt86Q aggregate formation, whereas 14-3-3beta or eta siRNA suppression did not. This indicates that 14-3-3zeta participates in aggregate formation under nonnative conditions. Our data support a novel role for 14-3-3zeta in the aggregate formation of nonnative, aggregation-prone proteins.
Also flagged:NFATnuclear factor of activated T-cellstranscription factorsbindingchromatincoactivators
Journal Article2007-11-17No SnippetsNguyen T, Di Giovanni S.
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The NFAT (nuclear factor of activated T-cells) family of transcription factors functions as integrators of multiple signaling pathways by binding to chromatin in combination with other transcription factors and coactivators to regulate genes central for many developmental systems. Recent experimental evidence has shown that the calcineurin/NFAT signaling pathway is important in axonal growth and guidance during vertebrate development. In fact, studies with triple NFATc2/c3/c4 mutant mice demonstrate that the extension and organization of sensory axon projection and commissural axon growth are both dependent upon NFAT activity. Neurotrophin and L-type calcium channel signaling modulate intracellular calcium levels to regulate the nuclear import and transcriptional activity of NFAT by activating the phosphatase calcineurin. The rephosphorylation and subsequent export of NFAT from the nucleus is mediated by several kinases, including GSK-3beta, which contribute to the fine tuning of NFAT transcriptional activity in neurons. However, currently, no direct transcriptional targets for NFAT have been identified in a chromatin environment in the nervous system. Undiscovered are also the binding partners of NFAT that might combinatorially regulate specific genes important for neuronal development. This review will discuss the current knowledge related to NFAT signaling in the nervous system development and the potential for future research directions.
<h4>Background/aims</h4>HFE protein controls iron absorption and cycling, and HFE mutations influence iron status. The aim was to evaluate the effect of the HFE genotype on the need for iron and erythropoietin in Italian hemodialysis patients.<h4>Methods</h4>Ninety-six prevalent patients were evaluated at the time of enrolment and prospectively followed for 3 years. Patients were given r-HuEPO and Fe3+-gluconate according to guidelines. The HFE genotype was determined by restriction analysis.<h4>Results</h4>Three patients (3%) carried the C282Y mutation, 4 (4%) were homozygous and 18 (19%) heterozygous for the H63D mutation, and 71 (74%) were negative for both. At enrolment, subjects positive for HFE mutations had higher iron stores (ferritin 617 +/- 663 vs. 423 +/- 386 ng/ml, p = 0.05), were receiving less iron (82.5 +/- 66 vs. 110 +/- 154 mg/month, p = 0.05) and a lower r-HuEPO dosage (98 +/- 83 vs. 142 +/- 138 U/kg/week, p = 0.03). Consistently during the study period, patients positive for HFE mutations received a lower amount of r-HuEPO (94.5 +/- 63 vs. 186 +/- 344 U/kg/week, p = 0.01) and iron (97 +/- 63 vs. 121 +/- 68 mg/month, p = 0.07). Upon Cox regression analysis, after adjustment for confounding variables, the presence of HFE mutations was associated with a reduced risk of death (HR 0.6, 95% CI 0.34-1.03, p = 0.06).<h4>Conclusion</h4>HFE mutations reduce the amount of r-HuEPO and iron necessary to support erythropoiesis in hemodialysis.
Also flagged:p68p72RNA helicasescancertumourDEAD-box proteins
Journal Article2007-11-15No SnippetsWilson BJ, Giguère V.
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<h4>Background</h4>The Oncominedatabase is an online collection of microarrays from various sources, usually cancer-related, and contains many "multi-arrays" (collections of analyzed microarrays, in a single study). As there are often many hundreds of tumour samples/microarrays within a single multi-array results from coexpressed genes can be analyzed, and are fully searchable. This gives a potentially significant list of coexpressed genes, which is important to define pathways in which the gene of interest is involved. However, to increase the likelihood of revealing truly significant coexpressed genes we have analyzed their frequency of occurrence over multiple studies (meta-analysis), greatly increasing the significance of results compared to those of a single study.<h4>Results</h4>We have used the DEAD-box proteins p68(Ddx5) and p72(Ddx17) as models for this coexpression frequency analysis as there are defined functions for these proteins in splicing and transcription (known functions which we could use as a basis for quality control). Furthermore, as these proteins are highly similar, interact together, and may be to some degree functionally redundant, we then analyzed the overlap between coexpressed genes of p68 and p72. This final analysis gave us a highly significant list of coexpressed genes, clustering mainly in splicing and transcription (recapitulating their published roles), but also revealing new pathways such as cytoskeleton remodelling and protein folding. We have further tested a predicted pathway partner, RNA helicase A(Dhx9) in a reciprocal meta-analysis that identified p68 and p72 as being coexpressed, and further show a direct interaction of Dhx9 with p68 and p72, attesting to the predictive nature of this technique.<h4>Conclusion</h4>In summary we have extended the capabilities of Oncomineby analyzing the frequency of coexpressed genes over multiple studies, and furthermore assessing the overlap with a known pathway partner (in this case p68 with p72). We have shown our predictions corroborate previously published studies on p68 and p72, and that novel predictions can be easily tested. These techniques are widely applicable and should increase the quality of data from future meta-analysis studies.
<h4>Background</h4>Cis-acting transcriptional regulatory elements in mammalian genomes typically contain specific combinations of binding sites for various transcription factors. Although some cis-regulatory elements have been well studied, the combinations of transcription factors that regulate normal expression levels for the vast majority of the 20,000 genes in the human genome are unknown. We hypothesized that it should be possible to discover transcription factor combinations that regulate gene expression in concert by identifying over-represented combinations of sequence motifs that occur together in the genome. In order to detect combinations of transcription factor binding motifs, we developed a data mining approach based on the use of association rules, which are typically used in market basket analysis. We scored each segment of the genome for the presence or absence of each of 83 transcription factor binding motifs, then used association rule mining algorithms to mine this dataset, thus identifying frequently occurring pairs of distinct motifs within a segment.<h4>Results</h4>Support for most pairs of transcription factor binding motifs was highly correlated across different chromosomes although pair significance varied. Known true positive motif pairs showed higher association rule support, confidence, and significance than background. Our subsets of high-confidence, high-significance mined pairs of transcription factors showed enrichment for co-citation in PubMed abstracts relative to all pairs, and the predicted associations were often readily verifiable in the literature.<h4>Conclusion</h4>Functional elements in the genome where transcription factors bind to regulate expression in a combinatorial manner are more likely to be predicted by identifying statistically and biologically significant combinations of transcription factor binding motifs than by simply scanning the genome for the occurrence of binding sites for a single transcription factor.
Also flagged:neurodegenerative disorderorganizationglutamineHuntington's diseaseHuntingtinHD
Journal Article2007-11-15No SnippetsCandiani S, Pestarino M, Cattaneo E, Tartari M.
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<h4>Background</h4>Huntington's disease is an inherited neurodegenerative disorder that is caused by the expansion of an N-terminal polyQ stretch in the huntingtin protein. In order to investigate the hypothesis that huntingtin was already involved in development of the nervous system in the last common ancestor of chordates, we isolated and characterised the huntingtin homologue from the amphioxus Branchiostoma floridae. In the present paper the amphioxus general term must be referred to Branchiostoma floridae.<h4>Results</h4>In this report, we show that the exon-intron organization of the amphioxus huntingtin gene is highly conserved with that of other vertebrates species. The AmphiHtt protein has two glutamine residues in the position of the typical vertebrate polyQ tract. Sequence conservation is greater along the entire length of the protein than in a previously identified Ciona huntingtin. The first three N-terminal HEAT repeats are highly conserved in vertebrates and amphioxus, although exon rearrangement has occurred in this region. AmphiHtt expression is detectable by in situ hybridization starting from the early neurula stage, where it is found in cells of the neural plate. At later stages, it is retained in the neural compartment but also it appears in limited and well-defined groups of non-neural cells. At subsequent larval stages, AmphiHtt expression is detected in the neural tube, with the strongest signal being present in the most anterior part.<h4>Conclusion</h4>The cloning of amphioxus huntingtin allows to infer that the polyQ in huntingtin was already present 540 million years ago and provides a further element for the study of huntingtin function and its evolution along the deuterostome branch.
Also flagged:HspB8Bag3macroautophagyheat shock proteinsHspneuromuscular disorders
Journal Article2007-11-15No SnippetsCarra S, Seguin SJ, Lambert H, Landry J.
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Mutations in HspB8, a member of the B group of heat shock proteins (Hsp), have been associated with human neuromuscular disorders. However, the exact function of HspB8 is not yet clear. We previously demonstrated that overexpression of HspB8 in cultured cells prevents the accumulation of aggregation-prone proteins such as the polyglutamine protein Htt43Q. Here we report that HspB8 forms a stable complex with Bag3 in cells and that the formation of this complex is essential for the activity of HspB8. Bag3 overexpression resulted in the accelerated degradation of Htt43Q, whereas Bag3 knockdown prevented HspB8-induced Htt43Q degradation. Additionally, depleting Bag3 caused a reduction in the endogenous levels of LC3-II, a key molecule involved in macroautophagy, whereas overexpressing Bag3 or HspB8 stimulated the formation LC3-II. These results suggested that the HspB8-Bag3 complex might stimulate the degradation of Htt43Q by macroautophagy. This was confirmed by the observation that treatments with macroautophagy inhibitors significantly decreased HspB8- and Bag3-induced degradation of Htt43Q. We conclude that the HspB8 activity is intrinsically dependent on Bag3, a protein that may facilitate the disposal of doomed proteins by stimulating macroautophagy.
Proneural basic helix-loop-helix proteins are key regulators of neurogenesis but their 'proneural' function is not well understood, partly because primary targets have not been systematically defined. Here, we identified direct transcriptional targets of the bHLH proteins Neurogenin and NeuroD and found that primary roles of these transcription factors are to induce regulators of transcription, signal transduction, and cytoskeletal rearrangement for neuronal differentiation and migration. We determined targets induced in both Xenopus and mouse, which represent evolutionarily conserved core mediators of Neurogenin and NeuroD activities. We defined consensus sequences for Neurogenin and NeuroD binding and identified responsive enhancers in seven shared target genes. These enhancers commonly contained clustered, conserved consensus-binding sites and drove neural-restricted transgene expression in Xenopus embryos. We then used this enhancer signature in a genome-wide computational approach to predict additional Neurogenin/NeuroD target genes involved in neurogenesis. Taken together, these data demonstrate that Neurogenin and NeuroD preferentially recognize neurogenesis-related targets through an enhancer signature of clustered consensus-binding sites and regulate neurogenesis by activating a core set of transcription factors, which build a robust network controlling neurogenesis.
Also flagged:voltage-dependent anion channel Vdac1trinucleotideneurodegenerative disorderspolyglutamineTBPvoltage dependent anion channel
Journal Article2007-11-14✓ 1 SnippetGhosh T, Pandey N, Maitra A, Brahmachari SK, Pillai B.
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…region of theHttprotein has been…
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Expansion of trinucleotide repeats in coding and non-coding regions of genes is associated with sixteen neurodegenerative disorders. However, the molecular effects that lead to neurodegeneration have remained elusive. We have explored the role of transcriptional dysregulation by TATA-box binding protein (TBP) containing an expanded polyglutamine stretch in a mouse neuronal cell culture based model. We find that mouse neuronal cells expressing a variant of human TBP harboring an abnormally expanded polyQ tract not only form intranuclear aggregates, but also show transcription dysregulation of the voltage dependent anion channel, Vdac1, increased cytochrome c release from the mitochondria and upregulation of genes involved in localized neuronal translation. On the other hand, unfolded protein response seemed to be unaffected. Consistent with an increased transcriptional effect, we observe an elevated promoter occupancy by TBP in vivo in TATA containing and TATA-less promoters of differentially expressed genes. Our study suggests a link between transcriptional dysfunction and cell death in trinucleotide repeat mediated neuronal dysfunction through voltage dependent anion channel, Vdac1, which has been recently recognized as a critical determinant of cell death.
Also flagged:transferrin receptor 1TfR1glycoproteinshemorrhagic feversWorld hemorrhagic feversα-dystroglycan
Journal Article2007-11-14✓ 1 SnippetFlanagan ML, Oldenburg J, Reignier T, Holt N, Hamilton GA, Martin VK, Cannon PM.
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…HFE…
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Arenaviruses are rodent-borne viruses, with five members of the family capable of causing severe hemorrhagic fevers if transmitted to humans. To date, two distinct cellular receptors have been identified that are used by different pathogenic viruses, alpha-dystroglycan by Lassa fever virus and transferrin receptor 1 (TfR1) by certain New World clade B viruses. Our previous studies have suggested that other, as-yet-unknown receptors are involved in arenavirus entry. In the present study, we examined the use of TfR1 by the glycoproteins (GPs) from a panel of New World clade B arenaviruses comprising three pathogenic and two nonpathogenic strains. Interestingly, we found that TfR1 was only used by the GPs from the pathogenic viruses, with entry of the nonpathogenic strains being TfR1 independent. The pathogenic GPs could also direct entry into cells by TfR1-independent pathways, albeit less efficiently. A comparison of the abilities of TfR1 orthologs from different species to support arenavirus entry found that the human and feline receptors were able to enhance entry of the pathogenic strains, but that neither the murine or canine forms were functional. Since the ability to use TfR1 is a characteristic feature of the human pathogens, this interaction may represent an important target in the treatment of New World hemorrhagic fevers. In addition, the ability to use TfR1 may be a useful tool to predict the likelihood that any existing or newly discovered viruses in this family could infect humans.
Also flagged:axonNetrinFraaxonsgrowth conecytoplasmic
Journal Article2007-11-14✓ 4 SnippetsGarbe DS, O'Donnell M, Bashaw GJ.
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Abstract)
…DCC ligand-receptor pair Netrin and Frazzled (Fra…
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…DCC, P3 does not mediate receptor self-association, and self-association is not sufficient to promote Fra…
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…The conservedDCCligand-receptor pair Netrin…
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…contrast to vertebrateDCC, P3 does not…
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The conserved DCC ligand-receptor pair Netrin and Frazzled (Fra) has a well-established role in axon guidance. However, the specific sequence motifs required for orchestrating downstream signaling events are not well understood. Evidence from vertebrates suggests that P3 is important for transducing Netrin-mediated turning and outgrowth, whereas in C. elegans it was shown that the P1 and P2 conserved sequence motifs are required for a gain-of-function outgrowth response. Here, we demonstrate that Drosophila fra mutant embryos exhibit guidance defects in a specific subset of commissural axons and these defects can be rescued cell-autonomously by expressing wild-type Fra exclusively in these neurons. Furthermore, structure-function studies indicate that the conserved P3 motif (but not P1 or P2) is required for growth cone attraction at the Drosophila midline. Surprisingly, in contrast to vertebrate DCC, P3 does not mediate receptor self-association, and self-association is not sufficient to promote Fra-dependent attraction. We also show that in contrast to previous findings, the cytoplasmic domain of Fra is not required for axonal localization and that neuronal expression of a truncated Fra receptor lacking the entire cytoplasmic domain (Fra delta C) results in dose-dependent defects in commissural axon guidance. These findings represent the first systematic dissection of the cytoplasmic domains required for Fra-mediated axon attraction in the context of full-length receptors in an intact organism and provide important insights into attractive axon guidance at the midline.
Also flagged:lipiddiabetesglucoseantibodieschemokinesCOX-2
Journal Article2007-11-14No SnippetsShanmugam N, Figarola JL, Li Y, Swiderski PM, Rahbar S, Natarajan R.
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<h4>Objective</h4>The reactions of carbohydrate- or lipid-derived intermediates with proteins lead to the formation of Maillard reaction products, which subsequently leads to the formation of advanced glycation/lipoxidation end products (AGE/ALEs). Levels of AGE/ALEs are increased in diseases like diabetes. Unlike AGEs, very little is known about ALE effects in vitro. We hypothesized that ALEs can have proinflammatory effects in monocytes.<h4>Research design and methods</h4>In a profiling approach, conditioned media from THP-1 cells either cultured in normal glucose (5.5 mmol/l) or treated with MDA-Lys or MDA alone were hybridized to arrays containing antibodies to 120 known human cytokines/chemokines. Pathway analyses with bioinformatics software were used to identify signalling networks.<h4>Results</h4>Synthetic ALE (malondialdehyde-lysine [MDA-Lys]) (50 micromol/l) could induce oxidant stress and also activate the transcriptional factor nuclear factor-kappaB (NF-kappaB) in THP-1 monocytes. MDA-Lys also significantly increased the expression of key candidate proinflammatory genes, interferon-gamma-inducible protein-10, beta1- and beta2-integrins, cyclooxygenase-2 (COX-2), monocyte chemoattractant protein-1 (MCP-1), interleukin-6 and -8, and inducible nitric-oxide synthase, which are also associated with monocyte dysfunction. Several key target proinflammatory proteins were significantly induced by MDA-Lys relative to normal glucose or MDA alone, including MCP-1; tumor necrosis factor ligand superfamily member-14; chemokine CC motif ligand-11 (CCL11); growth-related oncogene-alpha, -beta, and -gamma; and chemokine CXC motif ligand-13. Bioinformatics analyses identified a network of chemokine signaling among MDA-Lys-regulated genes. MDA-Lys also increased monocyte binding to vascular smooth muscle and endothelial cells. Furthermore, plasma from diabetic rats showed significantly higher levels of MDA-Lys and CCL11.<h4>Conclusions</h4>These new results suggest that ALEs can promote monocyte activation and vascular complications via induction of inflammatory pathways and networks.
Also flagged:calciumalginategentamicinbacitracinoptochinerythromycin
Journal Article2007-11-14No SnippetsSá-Leão R, Nunes S, Brito-Avô A, Alves CR, Carriço JA, Saldanha J, Almeida JS, Santos-Sanches I, de Lencastre H.
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Day care centers (DCCs) are unique settings where young children are at increased risk for colonization by pneumococci and Haemophilus influenzae. Although point prevalence studies in DCCs are frequent, only a few longitudinal studies on the dynamics of colonization have been published. We conducted a 1-year longitudinal study with 11 sampling periods on nasopharyngeal carriage of pneumococci and H. influenzae among 47 children who attended a single DCC. All isolates were antibiotyped and genotyped by pulsed-field gel electrophoresis. Pneumococci were also serotyped. Of the 414 samples obtained, 61.4% contained pneumococci, and 87% contained H. influenzae. Only 8.3% of the samples were negative for both species. Twenty-one pneumococcal clones and 47 H. influenzae clones were identified. Introduction of clones occurred during all year. Ninety-eight percent and 96% of all pneumococcal and H. influenzae isolates, respectively, belonged to clones shared by more than one child. Children were sequentially colonized with up to six pneumococcal clones (mean, 3.6) and five serotypes and nine H. influenzae clones (mean, 7.1). Clones with increased capacity for transmission and/or prolonged colonization were identified in both species. These two fitness properties appeared to be independent. In conclusion, among DCC attendees, a high rate of acquisition and turnover of strains was observed, and all children were overwhelmingly colonized by clones shared with others. DCCs are units where permanent introduction of new clones occurs, and attendees, as a whole, provide a pool of hosts where the fittest clones find privileged opportunities to persist and expand.
Also flagged:GBF1guanine nucleotide exchange factorsADP-ribosylation factorscoat proteinsGolgiadaptor proteins
Journal Article2007-11-14No SnippetsManolea F, Claude A, Chun J, Rosas J, Melançon P.
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We examined the relative function of the two classes of guanine nucleotide exchange factors (GEFs) for ADP-ribosylation factors that regulate recruitment of coat proteins on the Golgi complex. Complementary overexpression and RNA-based knockdown approaches established that GBF1 regulates COPI recruitment on cis-Golgi compartments, whereas BIGs appear specialized for adaptor proteins on the trans-Golgi. Knockdown of GBF1 and/or COPI did not prevent export of VSVGtsO45 from the endoplasmic reticulum (ER), but caused its accumulation into peripheral vesiculotubular clusters. In contrast, knockdown of BIG1 and BIG2 caused loss of clathrin adaptor proteins and redistribution of several TGN markers, but had no impact on COPI and several Golgi markers. Surprisingly, brefeldin A-inhibited guanine nucleotide exchange factors (BIGs) knockdown prevented neither traffic of VSVGtsO45 to the plasma membrane nor assembly of a polarized Golgi stack. Our observations indicate that COPII is the only coat required for sorting and export from the ER exit sites, whereas GBF1 but not BIGs, is required for COPI recruitment, Golgi subcompartmentalization, and cargo progression to the cell surface.
Also flagged:Netrin-1 receptordopaminebehaviouralamphetaminepsychiatric disordersschizophrenia
Journal Article2007-11-14✓ 5 SnippetsGrant A, Hoops D, Labelle-Dumais C, Prévost M, Rajabi H, Kolb B, Stewart J, Arvanitogiannis A, Flores C.
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Abstract)
…Concomitantly, using conditioned place preference, locomotor activity and prepulse inhibition paradigms, we found that reduced DCC diminishes the rewarding and behavioural-activating effects of amphetamine and protects against amphetamine-induced deficits in sensorimotor gating.…
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…These findings demonstrate that reduced DCC during development results in a behavioural phenotype opposite to that observed in developmental models of schizophrenia and identify DCC as a critical factor in the development of DA function.…
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…the function ofDCC(deleted in colorectal…
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…effects of reducedDCCon several indicators…
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…develop with reducedDCCdisplay increased basal…
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The mesocorticolimbic dopamine (DA) system is implicated in neurodevelopmental psychiatric disorders including schizophrenia but it is unknown how disruptions in brain development modify this system and increase predisposition to cognitive and behavioural abnormalities in adulthood. Netrins are guidance cues involved in the proper organization of neuronal connectivity during development. We have hypothesized that variations in the function of DCC (deleted in colorectal cancer), a netrin-1 receptor highly expressed by DA neurones, may result in altered development and organization of mesocorticolimbic DA circuitry, and influence DA function in the adult. To test this hypothesis, we assessed the effects of reduced DCC on several indicators of DA function. Using in-vivo microdialysis, we showed that adult mice that develop with reduced DCC display increased basal DA levels in the medial prefrontal cortex and exaggerated DA release in response to the indirect DA agonist amphetamine. In contrast, these mice exhibit normal levels of DA in the nucleus accumbens but significantly blunted amphetamine-induced DA release. Concomitantly, using conditioned place preference, locomotor activity and prepulse inhibition paradigms, we found that reduced DCC diminishes the rewarding and behavioural-activating effects of amphetamine and protects against amphetamine-induced deficits in sensorimotor gating. Furthermore, we found that adult DCC-deficient mice exhibit altered dendritic spine density in layer V medial prefrontal cortex pyramidal neurones but not in nucleus accumbens medium spiny neurones. These findings demonstrate that reduced DCC during development results in a behavioural phenotype opposite to that observed in developmental models of schizophrenia and identify DCC as a critical factor in the development of DA function.
Also flagged:Protein phosphatase 1Hcolon adenocarcinomasignal transductiongene expressionPPM1Hprotein phosphatase 2C
Journal Article2007-11-14✓ 5 SnippetsSugiura T, Noguchi Y, Sakurai K, Hattori C.
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Abstract)
…Native, but not inactive, PPM1H expressed in HeLa cells increased the mobility of CSE1L on SDS gels and a similar mobility shift was observed for purified CSE1L after treatment with PPM1H in vitro, supporting the notion that CSE1L is a substrate of PPM1H.…
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…Protein phosphatase 1H, overexpressed in colon adenocarcinoma, is associated with CSE1L.…
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…PPM1H controls cell cycle and proliferation of cancer cells potentially through dephosphorylation of CSE1L and might be a new target of anticancer drugs.…
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…is associated withCSE1L.…
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…ectrometry analysis identifiedCSE1L, a proliferation and…
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In search for a new anticancer drug target, we explored genes involved in colon adenocarcinoma development through dysregulation of a signal transduction pathway. By using the gene expression profile database, we found protein phosphatase 1H (PPM1H), belonging to the protein phosphatase 2C (PP2C) family, upregulated in colon adenocarcinomas compared with normal colon tissues. RT-PCR analysis verified the elevated level of PPM1H expression in colon cancer cell lines relative to a normal colon cell line. PPM1H encodes a protein with a molecular mass of approximately 50 kDa that resides in the cytoplasm. PPM1H fused with maltose-binding protein expressed in E. coli exhibited phosphatase activity characteristic of the PP2C family. Co-immunoprecipitation coupled with mass spectrometry analysis identified CSE1L, a proliferation and apoptosis-related protein, as a PPM1H-interacting protein. Native, but not inactive, PPM1H expressed in HeLa cells increased the mobility of CSE1L on SDS gels and a similar mobility shift was observed for purified CSE1L after treatment with PPM1H in vitro, supporting the notion that CSE1L is a substrate of PPM1H. Dominant negative PPM1H protected HeLa cells from cell death triggered by staurosporine or taxol. Additionally, knockdown of PPM1H expression with small interfering RNAs suppressed the growth of MCF-7 cells weakly but consistently. PPM1H controls cell cycle and proliferation of cancer cells potentially through dephosphorylation of CSE1L and might be a new target of anticancer drugs.
Gene transfer strategies to reduce levels of mutant huntingtin (mHtt) mRNA and protein by targeting human Htt have shown therapeutic promise in vivo. Previously, we have reported that a specific, adeno-associated viral vector (rAAV)-delivered short-hairpin RNA (siHUNT-2) targeting human Htt mRNA unexpectedly decreased levels of striatal-specific transcripts in both wild-type and R6/1 transgenic HD mice. The goal of this study was to determine whether the siHUNT-2-mediated effect was due to adverse effects of RNA interference (RNAi) expression in the brain. To this end, we designed two catalytically active hammerhead ribozymes directed against the same region of human Htt mRNA targeted by siHUNT-2 and delivered them to wild-type and R6/1 transgenic HD mice. After 10 weeks of continuous expression, these ribozymes, like siHUNT-2, negatively impacted the expression of a subset of genes in the striatum. This effect was independent of rAAV transduction and specific to the targeting of a unique sequence in human Htt mRNA. After consideration of the known potential RNAi-specific toxic mechanisms, only cleavage of an unintended RNA target can account for the data reported herein. Thus, long-term rAAV-mediated RNAi in the brain does not, in and of itself, negatively affect striatal gene expression. These findings have important implications in the development of therapeutic RNAi for the treatment of neurological disease.
Also flagged:Bromocriptinehyperglycemiaprolactinsecretionglucosetype 1 diabetes
Journal Article2007-11-10✓ 1 SnippetDurant S, Coulaud J, Homo-Delarche F.
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…type 1 ½ diabetes…
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The effects of bromocriptine (10 mg/kg), known to inhibit prolactin secretion and lower autoimmune processes, were studied on glucose homeostasis in non-fasted non-obese diabetic mice, a spontaneous model of type 1 diabetes. Hyperglycemia was observed 120 and 240 min after i.p. but not s.c. injection. Bromocriptine administration i.p. led to rapid and marked hyperglycemia characterized by sexual dimorphism with males having higher glycemia than females. Bromocriptine induced a rapid but transient decrease in insulinemia in males only and biphasic increases in glucagon levels and a sustained stimulatory effect on circulating corticosterone in both sexes. Bromocriptine-induced hyperglycemia involved D2-dopaminergic receptors, as demonstrated by the inhibitory effect of the D2-dopamine antagonist, metoclopramide (10 mg/kg). Simultaneous injection of bromocriptine and metoclopramide also blocked the rise in blood corticosterone. In conclusion, by inducing hyperglycemia, i.p. bromocriptine administration to prediabetic autoimmune mice may counteract its beneficial anti-immunostimulatory effects.
Also flagged:endothelin-1vascular endothelial growth factorheart failurepulmonaryvasoconstrictionpulmonary hypertension
Journal Article2007-11-09✓ 1 SnippetRay L, Mathieu M, Jespers P, Hadad I, Mahmoudabady M, Pensis A, Motte S, Peters IR, Naeije R, McEntee K.
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Abstract)
…MPR2), serotonin transporter (5-HTT) and the 5-HT(2B)…
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Heart failure is a cause of pulmonary vasoconstriction and remodelling, leading to pulmonary hypertension (PH) and decreased survival. The pathobiology of PH in heart failure remains incompletely understood. We investigated pulmonary vascular function and signalling molecules in early stage PH secondary to experimental heart failure. Eight beagle dogs with overpacing-induced heart failure underwent haemodynamic assessment and postmortem pulmonary arterial reactivity, morphometry and quantification of genes encoding for factors involved in vascular reactivity and remodelling: endothelin-1 (ET-1), ETA and ETB receptors, vascular endothelial growth factor (VEGF), VEGF receptors 1 and 2 (VEGFR1 and VEGFR2), endothelial nitric oxide synthase, angiopoietin-1, bone morphogenetic protein receptors (BMPR1A and BMPR2), serotonin transporter (5-HTT) and the 5-HT(2B) receptor. Overpacing was associated with a decrease in cardiac output and an increase in pulmonary vascular pressures. However, there were no changes in pulmonary vascular resistance or in arteriolar medial thickness. There were increased expressions of genes encoding for ET-1, ETB, VEGF and VEGFR2, while expression of the other genes analysed remained unchanged. In vitro, pulmonary arteries showed decreased relaxation and increased reactivity, while systemic mammary arteries were unaffected. Early PH in heart failure is characterized by altered vasoreactivity and increased ET-1/ETB and VEGF/VEGFR2 signalling.
Also flagged:gene expressiontranscription factorsTFbindingDNase IRET
Journal Article2007-11-09✓ 1 SnippetYu X, Lin J, Zack DJ, Qian J.
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Results)
…include FOXJ2, CHX10,POU3F2and CRX.…
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<h4>Background</h4>Evolutionary conservation has been used successfully to help identify cis-acting DNA regions that are important in regulating tissue-specific gene expression. Motivated by increasing evidence that some DNA regulatory regions are not evolutionary conserved, we have developed an approach for cis-regulatory region identification that does not rely upon evolutionary sequence conservation.<h4>Results</h4>The conservation-independent approach is based on an empirical potential energy between interacting transcription factors (TFs). In this analysis, the potential energy is defined as a function of the number of TF interactions in a genomic region and the strength of the interactions. By identifying sets of interacting TFs, the analysis locates regions enriched with the binding sites of these interacting TFs. We applied this approach to 30 human tissues and identified 6232 putative cis-regulatory modules (CRMs) regulating 2130 tissue-specific genes. Interestingly, some genes appear to be regulated by different CRMs in different tissues. Known regulatory regions are highly enriched in our predicted CRMs. In addition, DNase I hypersensitive sites, which tend to be associated with active regulatory regions, significantly overlap with the predicted CRMs, but not with more conserved regions. We also find that conserved and non-conserved CRMs regulate distinct gene groups. Conserved CRMs control more essential genes and genes involved in fundamental cellular activities such as transcription. In contrast, non-conserved CRMs, in general, regulate more non-essential genes, such as genes related to neural activity.<h4>Conclusion</h4>These results demonstrate that identifying relevant sets of binding motifs can help in the mapping of DNA regulatory regions, and suggest that non-conserved CRMs play an important role in gene regulation.
Mutations in the SLC40A1 gene result in a dominant genetic disorder [ferroportin disease; hereditary hemochromatosis type (HH) IV], characterized by iron overload with two different clinical manifestations, normal transferrin saturation with macrophage iron accumulation (the most prevalent type) or high transferrin saturation with hepatocyte iron accumulation (classical hemochromatosis phenotype). In previous studies, the mutational analysis of SLC40A1 gene has been performed at the genomic DNA level by PCR amplification and direct sequencing of all coding regions and flanking intron-exon boundaries (usually in 9 PCR reactions). In this study, we analyzed the SLC40A1 gene at the mRNA level, in two RT-PCR reactions, followed by direct sequencing and/or NIRCA (non-isotopic RNase cleavage assay). This protocol turned out to be rapid, sensitive and reliable, facilitating the detection of the SLC40A1 gene mutations in two patients with hyperferritinemia, normal transferrin saturation and iron accumulation predominantly in macrophages and Kupffer cells. The first one displayed the well-described alteration V162 Delta and the second a novel mutation (R178G) that was further detected in two relatives in a pedigree analysis. The proposed procedure would facilitate the wide-range molecular analysis of the SLC40A1 gene, contributing to better understanding the pathogenesis of the ferroportin disease.
Also flagged:amino-acidamino acidcupredoxinsamino acidsamino-acids
Journal Article2007-11-09No SnippetsBernardes JS, Dávila AM, Costa VS, Zaverucha G.
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<h4>Background</h4>Remote homology detection is a challenging problem in Bioinformatics. Arguably, profile Hidden Markov Models (pHMMs) are one of the most successful approaches in addressing this important problem. pHMM packages present a relatively small computational cost, and perform particularly well at recognizing remote homologies. This raises the question of whether structural alignments could impact the performance of pHMMs trained from proteins in the Twilight Zone, as structural alignments are often more accurate than sequence alignments at identifying motifs and functional residues. Next, we assess the impact of using structural alignments in pHMM performance.<h4>Results</h4>We used the SCOP database to perform our experiments. Structural alignments were obtained using the 3DCOFFEE and MAMMOTH-mult tools; sequence alignments were obtained using CLUSTALW, TCOFFEE, MAFFT and PROBCONS. We performed leave-one-family-out cross-validation over super-families. Performance was evaluated through ROC curves and paired two tailed t-test.<h4>Conclusion</h4>We observed that pHMMs derived from structural alignments performed significantly better than pHMMs derived from sequence alignment in low-identity regions, mainly below 20%. We believe this is because structural alignment tools are better at focusing on the important patterns that are more often conserved through evolution, resulting in higher quality pHMMs. On the other hand, sensitivity of these tools is still quite low for these low-identity regions. Our results suggest a number of possible directions for improvements in this area.
Also flagged:sertralineneurogenesisBDNFneurodegenerative disorderHDpathogenesis
Journal Article2007-11-09✓ 1 SnippetPeng Q, Masuda N, Jiang M, Li Q, Zhao M, Ross CA, Duan W.
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Huntington's disease (HD) is an inherited progressive neurodegenerative disorder characterized by progressive movement, psychiatric and cognitive disturbances. Previous studies have indicated that HD pathogenesis may be mediated in part by loss of brain derived neurotrophic factor (BDNF). Antidepressants selectively blocking serotonin reuptake can increase BDNF levels, and also may increase neurogenesis. Here we report that an SSRI antidepressant, sertraline, prolongs survival, improves motor performance, and ameliorates brain atrophy in the R6/2 HD mouse model. Six-week-old R6/2 mice and nontransgenic control mice were administered either sertraline or vehicle daily. Motor function was assessed in an accelerating rotarod test and evaluated at 10 weeks. R6/2 mice exhibited reduced time on the rod. Sertraline treatment improved the motor performance in R6/2 mice, but did not affect nontransgenic mice. R6/2 mice showed significant striatal atrophy which was reduced by sertraline treatment. These beneficial effects of sertraline are associated with enhanced neurogenesis and increased BDNF levels in brain treated with sertraline. The effective serum and brain levels of sertraline are comparable to the levels achieved in human antidepressant treatment. Our findings provide evidence that sertraline is neuroprotective in this HD model. Successful treatment with sertraline in depressed HD patients has been reported; moreover, sertraline is safe and well-tolerated for long-term administration, including in HD patients. Our findings suggest that a clinical trial of SSRI treatment in order to retard disease progression in human HD may be warranted.
Also flagged:Ironiron deficiencyliver diseasemetabolismbindingpolymerase
Journal Article2007-11-09✓ 5 SnippetsMcLaren CE, Gordeuk VR, Chen WP, Barton JC, Acton RT, Speechley M, Castro O, Adams PC, Snively BM, Harris EL, Reboussin DM, McLachlan GJ, Bean R, Hemochromatosis and Iron Overload Screening Study Research Investigators.
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Abstract)
…Compared with C2, adjusted odds of iron deficiency were significantly greater in C1 (14.9-47.5 for women, 60.6-3530 for men), adjusted odds of liver disease were significantly greater in C3 and C4 for African-American women and all men, and adjusted odds of any HFE mutation were increased in C3 (1.4-1.8 for women, 1.2-1.9 for men) and in C4 for Hispanic and white women (1.5 and 5.2, respectively) and men (2.8 and 4.7, respectively).…
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…Joint mixture modeling identifies a component with lesser SF and TS at risk for iron deficiency and 2 components with greater SF and TS at risk for liver disease or HFE mutations.…
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…whites in theHemochromatosisand Iron Overload…
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…measured in theHemochromatosisand Iron Overload…
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…odds of anyHFEmutation were increased…
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Bivariate mixture modeling was used to analyze joint population distributions of transferrin saturation (TS) and serum ferritin concentration (SF) measured in the Hemochromatosis and Iron Overload Screening (HEIRS) Study. Four components (C1, C2, C3, and C4) with successively age-adjusted increasing means for TS and SF were identified in data from 26,832 African Americans, 12,620 Asians, 12,264 Hispanics, and 43,254 whites. The largest component, C2, had normal mean TS (21% to 26% for women, 29% to 30% for men) and SF (43-82 microg/L for women, 165-242 microg/L for men), which consisted of component proportions greater than 0.59 for women and greater than 0.68 for men. C3 and C4 had progressively greater mean values for TS and SF with progressively lesser component proportions. C1 had mean TS values less than 16% for women (<20% for men) and SF values less than 28 microg/L for women (<47 microg/L for men). Compared with C2, adjusted odds of iron deficiency were significantly greater in C1 (14.9-47.5 for women, 60.6-3530 for men), adjusted odds of liver disease were significantly greater in C3 and C4 for African-American women and all men, and adjusted odds of any HFE mutation were increased in C3 (1.4-1.8 for women, 1.2-1.9 for men) and in C4 for Hispanic and white women (1.5 and 5.2, respectively) and men (2.8 and 4.7, respectively). Joint mixture modeling identifies a component with lesser SF and TS at risk for iron deficiency and 2 components with greater SF and TS at risk for liver disease or HFE mutations. This approach can identify populations in which hereditary or acquired factors influence metabolism measurement.
Also flagged:chronic hepatitiscirrhosishepatocellular carcinomahost cellsecdysone receptorecdysone
Journal Article2007-11-08✓ 1 SnippetTang W, Lázaro CA, Campbell JS, Parks WT, Katze MG, Fausto N.
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Hepatitis C virus (HCV) is a major cause of chronic hepatitis that can lead to cirrhosis and hepatocellular carcinoma. To study the effects of HCV protein expression on host cells, we established conditional expression of the full-length open reading frame (ORF) of an infectious cDNA clone of HCV (genotype 1a, H77 strain) in the nontransformed human hepatocyte line cell HH4 using the ecdysone receptor regulatory system. Treatment with the ecdysone analog ponasterone-A induced tightly regulated and dose-dependent full-length HCV ORF expression and properly processed HCV proteins. HCV Core, NS3, and NS5A colocalized in perinuclear regions and associated with the early endosomal protein EEA1. HCV ORF expression caused marked growth inhibition, increased intracellular reactive oxygen species, up-regulation of glutamate-l-cysteine ligase activity, increased glutathione level, and activation of nuclear factor kappaB. Although it was not directly cytotoxic, HCV ORF expression sensitized HH4 cells to Fas at certain concentrations but not to tumor necrosis factor-related apoptosis-inducing ligand. HCV ORF expression in HH4 cells up-regulated genes involved in innate immune response/inflammation and oxidative stress responses and down-regulated cell growth-related genes. Expression of HCV ORF in host cells may contribute to HCV pathogenesis by producing oxidative stress and increasing the expression of genes related to the innate immune response and inflammation.
Journal Article2007-11-08No SnippetsRüegg J, Swedenborg E, Wahlström D, Escande A, Balaguer P, Pettersson K, Pongratz I.
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The biological effects of dioxins are mediated by the aryl hydrocarbon receptor (AhR) and its dimerization partner, the AhR nuclear translocator (ARNT), and include interference with hormonal signaling pathways like the response to estrogens. The effects of estrogens are mediated by two estrogen receptor (ER) isoforms, ERalpha and ERbeta, which belong to the family of nuclear receptors. We have previously shown that ARNT can act as coactivator of the ERs. In this study, we show that recruitment of ARNT to AhR or hypoxia-inducible factor-1alpha signaling pathways as well as small interfering RNA-mediated down-regulation of ARNT levels lead to a reduction in ER transcriptional activity. Using chromatin immunoprecipitation assays, we demonstrate that this decrease coincides with reduced recruitment of ARNT to estradiol-regulated promoters. We show further that coactivation by ARNT as well as inhibition by dioxin acts stronger on ERbeta than on ERalpha activity. Additionally, we demonstrate that the effects of ARNT are dependent on the A/B domain of the ERs with the A/B domain of ERbeta being considerably stronger in mediating the coactivating effects of ARNT. Taken together, our studies show that recruitment of ARNT to the AhR after dioxin treatment can account for the antiestrogenic effect of dioxins. Moreover, we show for the first time that the inhibitory effects of dioxin are more pronounced on ERbeta than on ERalpha.
<h4>Background</h4>Boar taint is a major obstacle when using uncastrated male pigs for swine production. One of the main compounds causing this taint is androstenone, a pheromone produced in porcine testis. Here we use microarrays to study the expression of thousands of genes simultaneously in testis of high and low androstenone boars. The study allows identification of genes and pathways associated with elevated androstenone levels, which is essential for recognising potential molecular markers for breeding purposes.<h4>Results</h4>Testicular tissue was collected from 60 boars, 30 with extreme high and 30 with extreme low levels of androstenone, from each of the two breeds Duroc and Norwegian Landrace. The samples were hybridised to porcine arrays containing 26,877 cDNA clones, detecting 563 and 160 genes that were differentially expressed (p < 0.01) in Duroc and Norwegian Landrace, respectively. Of these significantly up- and down-regulated clones, 72 were found to be common for the two breeds, suggesting the possibility of both general and breed specific mechanisms in regulation of, or response to androstenone levels in boars. Ten genes were chosen for verification of expression patterns by quantitative real competitive PCR and real-time PCR. As expected, our results point towards steroid hormone metabolism and biosynthesis as important biological processes for the androstenone levels, but other potential pathways were identified as well. Among these were oxidoreductase activity, ferric iron binding, iron ion binding and electron transport activities. Genes belonging to the cytochrome P450 and hydroxysteroid dehydrogenase families were highly up-regulated, in addition to several genes encoding different families of conjugation enzymes. Furthermore, a number of genes encoding transcription factors were found both up- and down-regulated. The high number of clones belonging to ferric iron and iron ion binding suggests an importance of these genes, and the association between these pathways and androstenone levels is not previously described.<h4>Conclusion</h4>This study contributes to the understanding of the complex genetic system controlling and responding to androstenone levels in pig testis. The identification of new pathways and genes involved in the biosynthesis and metabolism of androstenone is an important first step towards finding molecular markers to reduce boar taint.
Also flagged:LOX-1bindingargininealanineC-type lectinlipoprotein
Journal Article2007-11-07No SnippetsFalconi M, Biocca S, Novelli G, Desideri A.
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<h4>Background</h4>Dimeric lectin-like oxidized low-density lipoprotein receptor-1 LOX-1 is the target receptor for oxidized low density lipoprotein in endothelial cells. In vivo assays revealed that in LOX-1 the basic spine arginine residues are important for binding, which is lost upon mutation of Trp150 with alanine. Molecular dynamics simulations of the wild-type LOX-1 and of the Trp150Ala mutant C-type lectin-like domains, have been carried out to gain insight into the severe inactivating effect.<h4>Results</h4>The mutation does not alter the dimer stability, but a different dynamical behaviour differentiates the two proteins. As described by the residues fluctuation, the dynamic cross correlation map and the principal component analysis in the wild-type the two monomers display a symmetrical motion that is not observed in the mutant.<h4>Conclusion</h4>The symmetrical motion of monomers is completely damped by the structural rearrangement caused by the Trp150Ala mutation. An improper dynamical coupling of the monomers and different fluctuations of the basic spine residues are observed, with a consequent altered binding affinity.
Mutations in the genes encoding presenilins (PS1 and PS2) account for the majority of cases of early-onset Alzheimer's disease. PS1 and PS2 form the catalytic center of gamma-secretase, an enzyme responsible for intramembraneous proteolysis of several type I transmembrane proteins. Many gamma-secretase substrates are coupled to intracellular signaling events such as cAMP-response element binding protein and Rac1/p21-activated kinase pathways, which are associated with synaptic function. Here, we have examined the activation of these pathways in neurons lacking PS1 expression or gamma-secretase activity. We found evidence for heightened steady-state activation of cAMP-response element binding protein, Rac1, and p21-activated kinase signaling in PS-deficient neurons. Our study highlights the importance of PS-dependent proteolytic cleavage of gamma-secretase substrates in regulating neuronal signal transduction.
Also flagged:Huntington's diseasepolyglutamineproteolysisHuntingtinagarosecytoplasmic
Journal Article2007-11-06No SnippetsWeiss A, Klein C, Woodman B, Sathasivam K, Bibel M, Régulier E, Bates GP, Paganetti P.
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A CAG-repeat gene expansion translated into a pathogenic polyglutamine stretch at the N-terminus of huntingtin triggers Huntington's Disease. Mutated huntingtin is predicted to adopt toxic properties mainly if aggregation-prone N-terminal fragments are released by proteolysis. Huntingtin-aggregates are indeed a major hallmark of this disorder and could represent useful markers of disease-onset or progression. We designed a simple method for qualitative and quantitative characterization of aggregates. For this, we analyzed samples from in vitro and in vivo Huntington's Disease models by agarose gel electrophoresis and showed that in the brain of transgenic mice huntingtin-aggregates became larger as a function of disease progression. This appears to be a property of cytoplasmic but not nuclear aggregates. In cell cultures, treatment with Congo Red inhibited aggregate growth but not total load. Finally, we showed that in primary striatal neurons and in brains of R6/2 and HdhQ150 mice, the presence of aggregates preceded initiation of any other functional deficits. This observation argues for a pathogenic role of huntingtin-aggregation in Huntington's Disease. Our results emphasize that thorough analysis of huntingtin metabolism and aggregation is now feasible, thus significantly improving the power of studies assessing therapies designed to lower huntingtin levels or to interfere with its aggregation.
Also flagged:E-cadherinestrogen receptor alphaER alphacancers-cell
Journal Article2007-11-06No SnippetsHuet G, Mérot Y, Le Dily F, Kern L, Ferrière F, Saligaut C, Boujrad N, Pakdel F, Métivier R, Flouriot G.
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The estrogen receptor alpha (ER alpha) is key in regulating normal breast development and function and is closely involved in the onset and progress of cancers. ER alpha transcriptional activity is mediated through two activation functions, AF1 and AF2, whose activity is tightly regulated in a cell-specific manner through yet unknown processes. Here, we demonstrate that cell-cell junctions generate cell permissiveness to AF1 through an up-regulation of the activity of an AF1 sub-region termed box 1. Moreover, the loss of E-cadherin expression is shown to silence the AF1 activity of ER alpha, allowing the receptor to mainly act through its AF2. This switch from an AF1 to an AF2 cell permissiveness also consequently results in the attenuation of ER alpha activity. Therefore, a loss of cell-cell junctions, a key process that occurs during the epithelial-mesenchymal transition, should have a broad impact on ER alpha transcriptional functions.
Also flagged:octanesbinding3-Aryltropanescocaine abuse8-azatropanesnitrogen
Journal Article2007-11-06No SnippetsMeltzer PC, Kryatova O, Pham-Huu DP, Donovan P, Janowsky A.
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3-Aryltropanes have been widely explored for potential medications for remediation of cocaine abuse. Research has focused predominantly on 8-azatropanes and it is now well recognized that these compounds can be designed to manifest varied selectivity and potency for inhibition of the dopamine, serotonin, and norepinephrine uptake systems. We had reported that the 8-nitrogen atom present in the 3-aryltropanes is not essential for tropanes to bind to monoamine uptake systems. We demonstrated that compounds in which the amine had been exchanged for an ether or a thioether retained binding potency and selectivity. We have now designed bivalent compounds in which two tropane moieties are linked by an intervening chain. These 8-homo- and 8-heterotropane bivalent compounds allowed a search for adjacent tropane binding sites on the DAT as well as a further exploration of whether the binding sites for 8-azatropanes are the same as those for other 8-heterotropanes. A comparison of these compounds with their progenitor tropanes cast into doubt the existence of proximal binding sites on the DAT, and offered support for the existence of different binding sites for the 8-azatropanes compared with 8-oxa- and 8-thiatropanes. Indeed, 8-aza bivalent tropanes inhibited DAT with potency about 10-fold lower (DAT: IC50 = 31 nM) than their monovalent counterparts. Furthermore, bivalent ligands in which one or both of the tropanes was devoid of an amine suffered a further loss of inhibitory potency. We conclude that it is unlikely that there exist two tropane binding sites in close proximity to one another on either the DAT or SERT.
Also flagged:fatty acidsfatty acidmetabolismFADS2breastfeedingFADS1
Journal Article2007-11-05No SnippetsCaspi A, Williams B, Kim-Cohen J, Craig IW, Milne BJ, Poulton R, Schalkwyk LC, Taylor A, Werts H, Moffitt TE.
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Children's intellectual development is influenced by both genetic inheritance and environmental experiences. Breastfeeding is one of the earliest such postnatal experiences. Breastfed children attain higher IQ scores than children not fed breast milk, presumably because of the fatty acids uniquely available in breast milk. Here we show that the association between breastfeeding and IQ is moderated by a genetic variant in FADS2, a gene involved in the genetic control of fatty acid pathways. We confirmed this gene-environment interaction in two birth cohorts, and we ruled out alternative explanations of the finding involving gene-exposure correlation, intrauterine growth, social class, and maternal cognitive ability, as well as maternal genotype effects on breastfeeding and breast milk. The finding shows that environmental exposures can be used to uncover novel candidate genes in complex phenotypes. It also shows that genes may work via the environment to shape the IQ, helping to close the nature versus nurture debate.
Also flagged:pathogenesispolyglutamine diseasesSpinocerebellar Ataxia type 1SCA1Huntington's diseaseHD
Journal Article2007-11-05✓ 1 SnippetBranco J, Al-Ramahi I, Ukani L, Pérez AM, Fernandez-Funez P, Rincón-Limas D, Botas J.
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Abstract)
…Spinocerebellar Ataxia type 1 (SCA1) and Huntington's disease (HD) are two polyglutamine disorders caused by expansion of a CAG repeat within the coding regions of the Ataxin-1 and Huntingtin proteins, respectively.…
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Spinocerebellar Ataxia type 1 (SCA1) and Huntington's disease (HD) are two polyglutamine disorders caused by expansion of a CAG repeat within the coding regions of the Ataxin-1 and Huntingtin proteins, respectively. While protein folding and turnover have been implicated in polyglutamine disorders in general, many clinical and pathological differences suggest that there are also disease-specific mechanisms. Taking advantage of a collection of genetic modifiers of expanded Ataxin-1-induced neurotoxicity, we performed a comparative analysis in Drosophila models of the two diseases. We show that while some modifier genes function similarly in SCA1 and HD Drosophila models, others have model-specific effects. Surprisingly, certain modifier genes modify SCA1 and HD models in opposite directions, i.e. they behave as suppressors in one case and enhancers in the other. Furthermore, we find that modulation of toxicity does not correlate with alterations in the formation of neuronal intranuclear inclusions. Our results point to potential common therapeutic targets in novel pathways, and to genes and pathways responsible for differences between Ataxin-1 and Huntingtin-induced neurodegeneration.
Also flagged:Prolinetranslation initiation factorsribosomal subunitcytoplasmicstress granuleseIF3
Journal Article2007-11-05No SnippetsKim JE, Ryu I, Kim WJ, Song OK, Ryu J, Kwon MY, Kim JH, Jang SK.
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The repression of translation in environmentally stressed eukaryotic cells causes the sequestration of translation initiation factors and the 40S ribosomal subunit into discrete cytoplasmic foci called stress granules (SGs). Most components of the preinitiation complex, such as eIF3, eIF4A, eIF4E, eIF4G, and poly(A)-binding protein, congregate into SGs under stress conditions. However, the molecular basis of translation factor sequestration into SGs has not been clearly elucidated. Here, we report that proline-rich transcript in brain (PRTB) protein interacts with eIF4G and participates in SG formation. PRTB was recruited to SG under sodium arsenite and heat stress conditions. When overexpressed, PRTB inhibited global translation and formed SGs containing TIA-1, eIF4G, and eIF3. Knockdown of PRTB reduced the SG formation induced by sodium arsenite. These results suggest that PRTB not only is a component of SG formed by cellular stresses but also plays an important role in SG formation via an interaction with the scaffold protein eIF4G, which is associated with many translation factors and mRNAs.
Also flagged:RNA-binding proteinslocalizationmetabolismregulatory RNA-binding proteinstranslationalbinding
Journal Article2007-11-05No SnippetsMangone M, Macmenamin P, Zegar C, Piano F, Gunsalus KC.
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Three-prime untranslated regions (3'UTRs) are widely recognized as important post-transcriptional regulatory regions of mRNAs. RNA-binding proteins and small non-coding RNAs such as microRNAs (miRNAs) bind to functional elements within 3'UTRs to influence mRNA stability, translation and localization. These interactions play many important roles in development, metabolism and disease. However, even in the most well-annotated metazoan genomes, 3'UTRs and their functional elements are not well defined. Comprehensive and accurate genome-wide annotation of 3'UTRs and their functional elements is thus critical. We have developed an open-access database, available at http://www.UTRome.org, to provide a rich and comprehensive resource for 3'UTR biology in the well-characterized, experimentally tractable model system Caenorhabditis elegans. UTRome.org combines data from public repositories and a large-scale effort we are undertaking to characterize 3'UTRs and their functional elements in C. elegans, including 3'UTR sequences, graphical displays, predicted and validated functional elements, secondary structure predictions and detailed data from our cloning pipeline. UTRome.org will grow substantially over time to encompass individual 3'UTR isoforms for the majority of genes, new and revised functional elements, and in vivo data on 3'UTR function as they become available. The UTRome database thus represents a powerful tool to better understand the biology of 3'UTRs.
Also flagged:chromosomechromosomestransposonstranscription factorGRAS transcription factorAt1g14920
Journal Article2007-11-05No SnippetsConte MG, Gaillard S, Lanau N, Rouard M, Périn C.
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GreenPhylDB (http://greenphyl.cirad.fr) is a comprehensive platform designed to facilitate comparative functional genomics in Oryza sativa and Arabidopsis thaliana genomes. The main functions of GreenPhylDB are to assign O. sativa and A. thaliana sequences to gene families using a semi-automatic clustering procedure and to create 'orthologous' groups using a phylogenomic approach. To date, GreenPhylDB comprises the most complete list of plant gene families, which have been manually curated (6421 families). GreenPhylDB also contains all of the phylogenomic relationships computed for 4375 families. A total of 492 TAIR, 1903 InterPro and 981 KEGG families and subfamilies were manually curated using the clusters created with the TribeMCL software. GreenPhylDB integrates information from several other databases including UniProt, KEGG, InterPro, TAIR and TIGR. Several entry points can be used to display phylogenomic relationships for A. thaliana or O. sativa sequences, using TAIR, TIGR gene ID, family name, InterPro, gene alias, UniProt or protein/nucleic sequence. Finally, a powerful phylogenomics tool, GreenPhyl Ortholog Search Tool (GOST), was incorporated into GreenPhylDB to predict orthologous relationships between O. sativa/A. thaliana protein(s) and sequences from other plant species.
Also flagged:Huntington diseaseHDpathogenesisneurodegenerative diseasesautosomal dominant illnessDeath
Journal Article2007-11-03✓ 1 SnippetVonsattel JP.
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Huntington disease (HD) occurs only in humans. Thus, its natural pathogenesis takes place exclusively within the human brains expressing the causative, mutated protein huntingtin (mhtt). The techniques applicable to postmortem human HD brains are inadequate for investigating the cellular pathogenesis. The creation of genetically engineered animals represents a critical moment in neuroscience. Monitoring the actions of either normal, or abnormal proteins at subcellular levels, and at different time points is now possible thanks to these models. They are the necessary substitutes to investigate the wild type (whtt), or mhtt. The postmortem neuropathologic phenotype of the human HD is well documented. Its pattern and spectrum are highly predictable. From this point of view, the existent models do not exhibit the phenotypic constellation of changes seen in the human HD brains. On one hand, this deficit reflects the limitations of the methods of evaluation used in a clinical setting. On the other hand, it highlights the limitations of the animals. The validity of the models probably should be measured by their capacity of reproducing the cellular dysfunctions of HD rather than the phenotype of the postmortem human brains. Although not perfect, these models are essential for modeling the human disease in cells, which is not feasible with postmortem human HD brains. Nonetheless, their relevance to the patient population remains to be determined. Ultimately needed are means preventing the disease to occur, the discovery of which probably depends on these models.
Also flagged:deathHuntington's diseaseHDneurodegenerative disorderHuntingtinproline
Journal Article2007-11-02✓ 1 SnippetZuchner T, Brundin P.
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Abstract)
…Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a mutation in the gene huntingtin and characterized by motor, cognitive and psychiatric symptoms.…
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Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a mutation in the gene huntingtin and characterized by motor, cognitive and psychiatric symptoms. Huntingtin contains a CAG repeat in exon 1. An expansion of this CAG repeat above 35 results in misfolding of Huntingtin, giving rise to protein aggregates and neuronal cell death. There are several transgenic HD mouse models that reproduce most of the features of the human disorder, for example protein inclusions, some neurodegeneration as well as motor and cognitive symptoms. At the same time, a subgroup of the HD transgenic mouse models exhibit dramatically reduced susceptibility to excitotoxicity. The mechanism behind this is unknown. Here, we review the literature regarding this phenomenon, attempt to explain what protein domains are crucial for this phenomenon and point toward a putative mechanism. We suggest, that the C-terminal domain of exon 1 Huntingtin, namely the proline rich domain, is responsible for mediating a neuroprotective effect against excitotoxicity. Furthermore, we point out the possible importance of this mechanism for future therapies in neurological disorders that have been suggested to be associated with excitotoxicity, for example Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis.
Journal Article2007-11-02✓ 1 SnippetGaunt TR, Rodríguez S, Day IN.
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…inflammatory bowel disease,hemochromatosis).…
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<h4>Background</h4>The frequency of a haplotype comprising one allele at each of two loci can be expressed as a cubic equation (the 'Hill equation'), the solution of which gives that frequency. Most haplotype and linkage disequilibrium analysis programs use iteration-based algorithms which substitute an estimate of haplotype frequency into the equation, producing a new estimate which is repeatedly fed back into the equation until the values converge to a maximum likelihood estimate (expectation-maximisation).<h4>Results</h4>We present a program, "CubeX", which calculates the biologically possible exact solution(s) and provides estimated haplotype frequencies, D', r2 and chi2 values for each. CubeX provides a "complete" analysis of haplotype frequencies and linkage disequilibrium for a pair of biallelic markers under situations where sampling variation and genotyping errors distort sample Hardy-Weinberg equilibrium, potentially causing more than one biologically possible solution. We also present an analysis of simulations and real data using the algebraically exact solution, which indicates that under perfect sample Hardy-Weinberg equilibrium there is only one biologically possible solution, but that under other conditions there may be more.<h4>Conclusion</h4>Our analyses demonstrate that lower allele frequencies, lower sample numbers, population stratification and a possible |D'| value of 1 are particularly susceptible to distortion of sample Hardy-Weinberg equilibrium, which has significant implications for calculation of linkage disequilibrium in small sample sizes (eg HapMap) and rarer alleles (eg paucimorphisms, q < 0.05) that may have particular disease relevance and require improved approaches for meaningful evaluation.
…proteins such aslinker histoneshistones H1/H5, PHD…
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<h4>Background</h4>Various histone acetylases (HATs) play a critical role in the regulation of gene expression, but the precise functions of many of those HATs are still unknown. Here we provide evidence that MYST4, a known HAT, may be involved in early mammalian gametogenesis.<h4>Results</h4>Although MYST4 mRNA transcripts are ubiquitous, protein expression was restricted to select extracts (including ovary and testis). Immunohistochemistry experiments performed on ovary sections revealed that the MYST4 protein is confined to oocytes, granulosa and theca cells, as well as to cells composing the blood vessels. The transcripts for MYST4 and all-MYST4-isoforms were present in oocytes and in in vitro produced embryos. In oocytes and embryos the MYST4 protein was localized in both the cytoplasm and nucleus. Within testis sections, the MYST4 protein was specific to only one cell type, the elongating spermatids, where it was exclusively nuclear.<h4>Conclusion</h4>We established that MYST4 is localized into specialized cells of the ovary and testis. Because the majority of these cells are involved in male and female gametogenesis, MYST4 may contribute to important and specific acetylation events occurring during gametes and embryo development.
Also flagged:tubulin18S rDNASleeping sicknessChagas diseaseleishmaniasismalaria
Journal Article2007-11-02No SnippetsDávila AM, Mendes PN, Wagner G, Tschoeke DA, Cuadrat RR, Liberman F, Matos L, Satake T, Ocaña KA, Triana O, Cruz SM, Jucá HC, Cury JC, Silva FN, Geronimo GA, Ruiz M, Ruback E, Silva FP, Probst CM, Grisard EC, Krieger MA, Goldenberg S, Cavalcanti MC, Moraes MO, Campos ML, Mattoso M.
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ProtozoaDB (http://www.biowebdb.org/protozoadb) is being developed to initially host both genomics and post-genomics data from Plasmodium falciparum, Entamoeba histolytica, Trypanosoma brucei, T. cruzi and Leishmania major, but will hopefully host other protozoan species as more genomes are sequenced. It is based on the Genomics Unified Schema and offers a modern Web-based interface for user-friendly data visualization and exploration. This database is not intended to duplicate other similar efforts such as GeneDB, PlasmoDB, TcruziDB or even TDRtargets, but to be complementary by providing further analyses with emphasis on distant similarities (HMM-based) and phylogeny-based annotations including orthology analysis. ProtozoaDB will be progressively linked to the above-mentioned databases, focusing in performing a multi-source dynamic combination of information through advanced interoperable Web tools such as Web services. Also, to provide Web services will allow third-party software to retrieve and use data from ProtozoaDB in automated pipelines (workflows) or other interoperable Web technologies, promoting better information reuse and integration. We also expect ProtozoaDB to catalyze the development of local and regional bioinformatics capabilities (research and training), and therefore promote/enhance scientific advancement in developing countries.
Also flagged:HAP1Huntington's diseaseHDpathogenesishuntingtin-associated protein 1microtubule-dependent transporters
Journal Article2007-11-01✓ 5 SnippetsRong J, Li SH, Li XJ.
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Abstract)
…A number of proteins are known to interact with huntingtin (htt), the Huntington's disease (HD) protein.…
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…Understanding the function of these htt-associated proteins could help elucidate the pathogenesis of HD and the role that htt plays in the disease process.…
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…interact with huntingtin (htt), the Huntington's disease…
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…function of thesehtt-associated proteins could hel…
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…the role thathttplays in the…
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A number of proteins are known to interact with huntingtin (htt), the Huntington's disease (HD) protein. Understanding the function of these htt-associated proteins could help elucidate the pathogenesis of HD and the role that htt plays in the disease process. The present review focuses on one such protein, huntingtin-associated protein 1 (HAP1), which has proved to be involved in intracellular trafficking. Unlike huntingtin, which is expressed ubiquitously throughout the brain and body, HAP1 is enriched in neurons, suggesting that its dysfunction could contribute to the selective neuropathology in HD. HAP1 binds microtubule-dependent transporters that engage anterograde or retrograde transport and also associates with a variety of organelles and membrane receptors. This raises the interesting issue of how the HAP1 trafficking function is regulated. We discuss recent evidence for the involvement of HAP1 in intracellular trafficking as well as potential mechanisms that may regulate its trafficking.
Also flagged:Neural cell adhesion molecule-180colorectal carcinomaneural cell adhesion moleculeNCAMtumorcolorectal cancer
Journal Article2007-11-01✓ 1 SnippetTascilar O, Cakmak GK, Tekin IO, Emre AU, Ucan BH, Irkorucu O, Karakaya K, Gül M, Engin HB, Comert M.
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<h4>Aim</h4>To evaluate the frequency of neural cell adhesion molecule (NCAM)-180 expression in fresh tumor tissue samples and to discuss the prognostic value of NCAM-180 in routine clinical practice.<h4>Methods</h4>Twenty-six patients (16 men, 10 women) with colorectal cancer were included in the study. Fresh tumor tissue samples and macroscopically healthy proximal margins of each specimen were subjected to flow-cytometric analysis for NCAM-180 expression.<h4>Results</h4>Flow-cytometric analysis determined NCAM-180 expression in whole tissue samples of macroscopically healthy colorectal tissues. However, NCAM-180 expression was positive in only one case (3.84%) with well-differentiated Stage II disease who experienced no active disease at 30 mon follow-up.<h4>Conclusion</h4>As a consequence of the limited number of cases in our series, it might not be possible to make a generalisation, nevertheless the routine use of NCAM-180 expression as a prognostic marker for colorectal carcinoma seems to be unfeasible and not cost-effective in clinical practice due to its very low incidence.
Also flagged:ALTalanine aminotransferasesteatosishepatitisliver diseasesHCV infection
Journal Article2007-11-01✓ 1 SnippetAkkaya O, Kiyici M, Yilmaz Y, Ulukaya E, Yerci O.
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<h4>Aim</h4>To investigate serum alanine aminotransferase (ALT) levels in relation to the clinical, biochemical, ultrasonographic and histological characteristics of patients with hepatitis C virus.<h4>Methods</h4>Duration of disease, HCV-RNA, liver steatosis, and the hepatitis activity index (HAI) were correlated with serum ALT in 36 patients with HCV. ALT values were also investigated in 16 control subjects without any liver diseases.<h4>Results</h4>In bivariate analyses, ALT levels correlated with duration of HCV infection (P < 0.01), HCV-RNA (P < 0.05), and the HAI (P < 0.01). Among the components of the HAI, ALT concentrations were significantly associated with periportal bridging/necrosis (P < 0.01) and fibrosis (P < 0.05). In multivariate analysis, periportal bridging/necrosis (beta = 0.508; P < 0.01), duration of HCV infection (beta = 0.413; P < 0.01), and HCV-RNA (beta = 0.253; P < 0.05) were independently associated with ALT activity. The normal ALT activity for men and women was < 23 IU/L and < 22 IU/L, respectively.<h4>Conclusion</h4>In patients with HCV, alterations in the liver tissue as reflected by ALT elevation are mainly associated with periportal bridging/necrosis, viral load and duration of disease. A cut-off value < 23 IU/L distinguished with high diagnostic accuracy healthy controls from patients with HCV.
Also flagged:HUPO BPPneurologic diseasesdigestionalpha-enolaseC14orf166heat- and acid-stable phosphoprotein
Journal Article2007-11-01No SnippetsWang J, Gu Y, Wang L, Hang X, Gao Y, Wang H, Zhang C.
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This study is a part of the HUPO Brain Proteome Project (BPP) pilot study, which aims at obtaining a reliable database of mouse brain proteome, at the comparison of techniques, laboratories, and approaches as well as at preparing subsequent proteome studies of neurologic diseases. The C57/Bl6 mouse brains of three developmental stages at embryonic day 16 (E16), postnatal day 7 (P7), and 8 wk (P56) (n = 5 in each group) were provided by the HUPO BPP executive committee. The whole brain proteins of each animal were individually prepared using 2-DE coupled with PDQuest software analysis. The protein spots representing developmentally related or stably expressed proteins were then prepared with in-gel digestion followed with MALDI-TOF/TOF MS/MS and analyzed using the MASCOT search engines to search the Swiss-Prot or NCBInr database. The 2-DE gel maps of the mouse brains of all of the developmental stages were obtained and submitted to the Data Collection Centre (DCC). The proteins alpha-enolase, stathmin, actin, C14orf166 homolog, 28,000 kDa heat- and acid-stable phosphoprotein, 3-mercaptopyruvate sulfurtransferase and 40 S ribosomal protein S3a were successfully identified. A further Western blotting analysis demonstrated that enolase is a protein up-regulated in the mouse brain from embryonic stage to adult stage. These data are helpful for understanding the proteome changes in the development of the mouse brain.
Also flagged:HLA-A1chromosomehuman leukocyte antigenHLAironalanine aminotransferase
Journal Article2007-11-01✓ 4 SnippetsOlsson KS, Ritter B, Hansson N.
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…<h4>Background</h4>Hemochromatosis is a recessively inherited disorder caused by a point mutation, C282Y of the HFE gene on chromosome 6p21.3 near the human leukocyte antigen (HLA) locus.…
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…hitchhiking with thehemochromatosismutation: does it…
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…<h4>Background</h4>Hemochromatosisis a recessively…
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…C282Y of theHFEgene on chromosome…
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<h4>Background</h4>Hemochromatosis is a recessively inherited disorder caused by a point mutation, C282Y of the HFE gene on chromosome 6p21.3 near the human leukocyte antigen (HLA) locus. It is unknown why some homozygotes develop a severe iron loading, while others do not. A recent study suggested that the A1-B8 haplotype may be associated with higher iron storage.<h4>Methods</h4>We studied HLA haplotypes of 85 probands, 31 females and 54 males, and their family members from a rural population where A1-B8 was common. We tested the hypothesis of a modifying effect of the A1-B8 haplotype.<h4>Results</h4>Most homozygotes had a mild phenotypic expression, and were often detected accidentally because of a laboratory routine including transferrin saturation. A disease-related morbidity [serum alanine aminotransferase (S-ALT) > 43 U] was present in 40%. Three had porphyria cutanea tarda. Two brothers with A1-B8 died of bronze diabetes, probably caused by co-inheritance of congenital spherocytosis. In females there were no significant differences in phenotypic expression between groups with regard to the presence or absence of A1-B8. Two females, <50 yr of age, with this haplotype had iron deficiency. Males with two copies of A1-B8 had significantly lower serum ferritin (P = 0.02) values than those without. Those with one A1-B8 haplotype were not different from those without. In men without A1-B8, those carrying HLA-A3 were not phenotypically different from those without this ancestral haplotype.<h4>Conclusion</h4>The A1-B8 haplotype hitchhiking with the C282Y mutation was not associated with a more efficient iron absorption. On the contrary, males with double copies of this haplotype expressed a milder phenotype, possibly an effect of local (environmental and/or genetic) factors.
Also flagged:HBeAgchronic hepatitis Bhepatitis B e antigenlamivudineadefovirinterferon
Journal Article2007-11-01✓ 1 SnippetLacey LF, Gane E.
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…in patients withDCC[ 23 ].…
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The purpose of this study was the economic evaluation of short-duration treatments of chronic hepatitis B (CHB) and longer duration antiviral treatment for up to 5 years. Two 10-health state Markov models were developed for hepatitis B e antigen (HBeAg)-positive and HBeAg-negative CHB patients respectively. The perspective of this economic evaluation was the Singapore healthcare system and CHB patient. The models followed cohorts of HBeAg-positive and HBeAg-negative CHB patients, respectively, over a period of 40 years, by which time the majority of the cohorts would have died if left untreated. Costs and benefits were discounted at 5% per annum. Annual rates of disease progression and the magnitude of treatment effects were obtained from the literature, with a focus on data obtained in Asian patients and meeting the criteria for therapy as described in internationally recognized management guidelines. Short-course therapy with alpha-interferon, or 1-year treatment with pegylated interferon alpha-2a, lamivudine or adefovir had limited impact on disease progression. In contrast, treatment of CHB with antiviral therapy for 5 years substantially decreased the rate of disease progression. Treatment with lamivudine for 1-year is highly cost-effective compared with no treatment of CHB but has limited effect on reducing the rate of disease progression. Compared with 1-year treatment with lamivudine, sequential antiviral therapies for up to 5 years (i.e. lamivudine plus adefovir on emergence of lamivudine resistance or adefovir plus lamivudine on emergence of adefovir resistance) are highly cost-effective by international standards. These conclusions are robust to uncertainties in model inputs and are consistent with the findings of other recently published studies.
Ultrashort echo time (UTE) imaging is a technique that can visualize tissues with sub-millisecond T(2) values that have little or no signal in conventional MRI techniques. The short-T(2) tissues, which include tendons, menisci, calcifications, and cortical bone, are often obscured by long-T(2) tissues. This paper introduces a new method of long-T(2) component suppression based on adiabatic inversion pulses that significantly improves the contrast of short-T(2) tissues. Narrow bandwidth inversion pulses are used to selectively invert only long-T(2) components. These components are then suppressed by combining images prepared with and without inversion pulses. Fat suppression can be incorporated by combining images with the pulses applied on the fat and water resonances. Scaling factors must be used in the combination to compensate for relaxation during the preparation pulses. The suppression is insensitive to RF inhomogeneities because it uses adiabatic inversion pulses. Simulations and phantom experiments demonstrate the adiabatic pulse contrast and how the scaling factors are chosen. In vivo 2D UTE images in the ankle and lower leg show excellent, robust long-T(2) suppression for visualization of cortical bone and tendons.
Also flagged:-classical major histocompatibility complex proteinsTumourstumourcancerimmune responsesimmune response
Journal Article2007-11-01✓ 1 SnippetGomes AQ, Correia DV, Silva-Santos B.
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Tumours develop in vertebrate organisms endowed with immune systems that are potentially able to eradicate them. Nevertheless, our ever-increasing understanding of the complex interactions between lymphocytes and tumour cells fuels the long-standing hope of developing efficient immunotherapies against cancer. This review focuses on a versatile family of proteins, the major histocompatibility complex class Ib, which has been recently implicated in both the establishment of anti-tumour immune responses and in tumour immune response evasion. We focus on a subset of class Ib proteins, human leukocyte antigen (HLA)-G, Qa-2, CD1d and NKG2D ligands, which bind to either stimulatory or inhibitory receptors expressed on T, natural killer (NK) and NKT lymphocytes, and thereby modulate their anti-tumour activity.
Also flagged:interferonporphyria cutanea tardapancreas tumorhepatic tumorshepatitis C virus infectionalcohol
Journal Article2007-11-01✓ 2 SnippetsMosterd K, Henquet C, Frank J.
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…Further, PCT can also be exacerbated by hepatitis C virus infection, alcohol, estrogens, HFE gene mutations predisposing for hereditary hemochromatosis, hexachlorobenzene, and 2,3,7,8-tetrachlorodibenzo-p-dioxin.…
A 53-year-old woman with blistering on the hands was diagnosed with porphyria cutanea tarda (PCT). At that time, she was treated with interferon for liver metastasis of a pancreas tumor since 7 years. Although apparently rare, PCT has been described as possible cutaneous manifestation both of hepatic tumors and interferon treatment. Further, PCT can also be exacerbated by hepatitis C virus infection, alcohol, estrogens, HFE gene mutations predisposing for hereditary hemochromatosis, hexachlorobenzene, and 2,3,7,8-tetrachlorodibenzo-p-dioxin. Therefore, it is important to keep in mind that the manifestation of PCT may be associated with distinct precipitating factors, which are briefly discussed here.
Also flagged:cardiovascular diseasemyocardial infarctionMIKIF6Incident Myocardial InfarctionVAMP8
Journal Article2007-11-01✓ 1 SnippetShiffman D, O'Meara ES, Bare LA, Rowland CM, Louie JZ, Arellano AR, Lumley T, Rice K, Iakoubova O, Luke MM, Young BA, Malloy MJ, Kane JP, Ellis SG, Tracy RP, Devlin JJ, Psaty BM.
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<h4>Objective</h4>We asked whether single nucleotide polymorphisms (SNPs) that had been nominally associated with cardiovascular disease in antecedent studies were also associated with cardiovascular disease in a population-based prospective study of 4522 individuals aged 65 or older.<h4>Methods and results</h4>Based on antecedent studies, we prespecified a risk allele and an inheritance model for each of 74 SNPs. We then tested the association of these SNPs with myocardial infarction (MI) in the Cardiovascular Health Study (CHS). The prespecified risk alleles of 8 SNPs were nominally associated (1-sided P<0.05) with increased risk of MI in White CHS participants. The false discovery rate for these 8 was 0.43, suggesting that about 4 of these 8 are likely to be true positives. The 4 of these 8 SNPs that had the strongest evidence for association with cardiovascular disease before testing in CHS (association in 3 antecedent studies) were in KIF6 (CHS HR=1.29; 90%CI 1.1 to 1.52), VAMP8 (HR=1.2; 90%CI 1.02 to 1.41), TAS2R50 (HR=1.13; 90%CI 1 to 1.27), and LPA (HR=1.62; 90%CI 1.09 to 2.42).<h4>Conclusions</h4>Although most of the SNPs investigated were not associated with MI in CHS, evidence from this investigation combined with previous studies suggests that 4 of these SNPs are likely associated with MI.
Also flagged:OX40 ligandcancerOX40LtumortumorsCD1d
Journal Article2007-11-01No SnippetsZaini J, Andarini S, Andarini S, Tahara M, Saijo Y, Ishii N, Kawakami K, Taniguchi M, Sugamura K, Nukiwa T, Kikuchi T.
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The exceptional immunostimulatory capacity of DCs makes them potential targets for investigation of cancer immunotherapeutics. We show here in mice that TNF-alpha-stimulated DC maturation was accompanied by increased expression of OX40 ligand (OX40L), the lack of which resulted in an inability of mature DCs to generate cellular antitumor immunity. Furthermore, intratumoral administration of DCs modified to express OX40L suppressed tumor growth through the generation of tumor-specific cytolytic T cell responses, which were mediated by CD4+ T cells and NKT cells. In the tumors treated with OX40L-expressing DCs, the NKT cell population significantly increased and exhibited a substantial level of IFN-gamma production essential for antitumor immunity. Additional studies evaluating NKT cell activation status, in terms of IFN-gamma production and CD69 expression, indicated that NKT cell activation by DCs presenting alpha-galactosylceramide in the context of CD1d was potentiated by OX40 expression on NKT cells. These results show a critical role for OX40L on DCs, via binding to OX40 on NKT cells and CD4+ T cells, in the induction of antitumor immunity in tumor-bearing mice.
…The Hemochromatosis and Iron Overload Screening Study screened 101,168 primary care participants for iron overload using transferrin saturation, unsaturated iron-binding capacity, ferritin, and HFE C282Y and H63D genotyping.…
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…screening test forhemochromatosis.…
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…points to detectHFEC282Y homozygous patients.…
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…Methods TheHemochromatosisand Iron Overload…
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<h4>Background</h4>Transferrin saturation is widely considered the preferred screening test for hemochromatosis. Unsaturated iron-binding capacity has similar performance at lower cost. However, the within-person biological variability of both these tests may limit their ability at commonly used cut points to detect HFE C282Y homozygous patients.<h4>Methods</h4>The Hemochromatosis and Iron Overload Screening Study screened 101,168 primary care participants for iron overload using transferrin saturation, unsaturated iron-binding capacity, ferritin, and HFE C282Y and H63D genotyping. Transferrin saturation and unsaturated iron-binding capacity were performed at initial screening and again when selected participants and controls returned for a clinical examination several months later. A missed case was defined as a C282Y homozygote who had transferrin saturation below the cut point (45% for women, 50% for men) or unsaturated iron-binding capacity above the cut point (150 micromol/L for women, 125 micromol/L for men) at the initial screening or the clinical examination, or both, regardless of serum ferritin.<h4>Results</h4>There were 209 C282Y previously undiagnosed homozygotes with transferrin saturation and unsaturated iron-binding capacity testing performed at the initial screening and clinical examination. Sixty-eight C282Y homozygotes (33%) would have been missed at these transferrin saturation cut points (19 men, 49 women; median serum ferritin level of 170 microg/L; first and third quartiles, 50 and 474 microg/L), and 58 homozygotes (28%) would have been missed at the unsaturated iron-binding capacity cut points (20 men, 38 women; median serum ferritin level of 168 microg/L; first and third quartiles, 38 and 454 microg/L). There was no advantage to using fasting samples.<h4>Conclusions</h4>The within-person biological variability of transferrin saturation and unsaturated iron-binding capacity limits their usefulness as an initial screening test for expressing C282Y homozygotes.
Cables is a cyclin-dependent kinase-binding nuclear protein that maps to chromosome 18q11-12. Here, we assessed Cables expression in 160 colorectal cancers (CRCs), its role in colon cancer cell growth, and the potential mechanisms of Cables inactivation. Expression levels, promoter methylation, and mutational status of Cables were investigated in colon cancer cell lines and primary colon tumors. Chromosome 18q loss of heterozygosity (LOH) was evaluated with multiple polymorphic markers. Cables inhibited cellular proliferation and colony formation in colon cancer cell lines. Cables expression was reduced in 65% of primary CRCs. No mutations were detected in 10 exons of Cables in 20 primary colon tumors. Cables promoter was methylated in cell lines with decreased Cables expression and vice versa. 5-Aza-2'-deoxycytidine resulted in increased Cables expression in methylated cell lines. There was a significant correlation between promoter methylation and Cables gene expression in primary colon tumors. Sixty-five percent of primary colon tumors demonstrated chromosome 18q LOH. LOH involving the Cables region was observed in 35% of cases, including those in which more distal portions of chromosome 18q were retained, and Cables expression was decreased in all such cases. Loss of Cables expression in 65% of CRCs suggests that it is a common event in colonic carcinogenesis, with promoter methylation and LOH appearing to be important mechanisms of Cables gene inactivation.
Also flagged:gelsolinTP53Bladder cancerbindingoligonucleotidebladder tumors
Journal Article2007-11-01No SnippetsSanchez-Carbayo M, Socci ND, Richstone L, Corton M, Behrendt N, Wulkfuhle J, Bochner B, Petricoin E, Cordon-Cardo C.
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Bladder cancer transformation and immortalization require the inactivation of key regulatory genes, including TP53. Genotyping of a large cohort of bladder cancer patients (n = 256) using the TP53 GeneChip showed mutations in 103 cases (40.2%), the majority of them mapping to the DNA-binding core domain. TP53 mutation status was significantly associated with tumor stage (P = 0.0001) and overall survival for patients with advanced disease (P = 0.01). Transcript profiling using oligonucleotide arrays was performed on a subset of these cases (n = 46). Supervised analyses identified genes differentially expressed between invasive bladder tumors with wild-type (n = 24) and mutated TP53 (n = 22). Pathway analyses of top-ranked genes supported the central role of TP53 in the functional network of such gene patterns. A proteomic strategy using reverse phase arrays with protein extracts of bladder cancer cell lines validated the association of identified differentially expressed genes, such as gelsolin, to TP53 status. Immunohistochemistry on tissue microarrays (n = 294) revealed that gelsolin was associated with tumor stage and overall survival, correlating positively with TP53 status in a subset of these patients. This study further reveals that TP53 mutations are frequent events in bladder cancer progression and identified gelsolin related to TP53 status, tumor staging, and clinical outcome by independent high-throughput strategies.
Neuroimaging technologies provide a powerful approach to exploring the genetic basis of individual differences in complex behaviors and vulnerability to neuropsychiatric illness. Functional MRI studies have established important physiologic links between genetic polymorphisms and robust differences in information processing within distinct brain regions and circuits that have been linked to the manifestation of various disease. Neuroimaging technologies represent a critical tool in efforts to understand the neurobiology of normal and pathologic behavioral states. Research capitalizing on neuroimagingbased integration will contribute to the identification of predictive markers and biologic pathways for neuropsychiatric disease vulnerability and the generation of novel targets for therapeutic intervention.
Also flagged:neurodegenerative diseaseendosomal sorting complexes required for transportintegral membrane proteinsvesiclesbodyESCRT-III
Journal Article2007-11-01✓ 5 SnippetsFilimonenko M, Stuffers S, Raiborg C, Yamamoto A, Malerød L, Fisher EM, Isaacs A, Brech A, Stenmark H, Simonsen A.
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…HeLa and N2a cells stably expressing a Tet-off inducible exon1 of Htt carrying a polyQ expansion of 65 or 103 residues, fused to monomeric enhanced CFP at the C termini (Htt 65Q- or 103Q-mCFP), were cultured as described (Yamamoto et al., 2006) and 100 ng/ml doxycycline (dox) was used to shut off production of new protein.…
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…Vps24 is required for efficient clearance of Htt inclusions. HeLa cells expressing HttQ65-mCFP (A) or HttQ103-mCFP (B) and N2a cells expressing HttQ103-mCFP (C) were transfected with control or Vps24 siRNA for 2 d and then incubated in the absence or presence of doxycycline for 3 d to turn off expression of HttQ65/Q103-mCFP.…
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…inducible exon1 ofHttcarrying a polyQ…
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…the C termini (Htt65Q- or 103Q-mCFP),…
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…to monomeric CFP (Htt65Q- or 103Q-mCFP)…
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The endosomal sorting complexes required for transport (ESCRTs) are required to sort integral membrane proteins into intralumenal vesicles of the multivesicular body (MVB). Mutations in the ESCRT-III subunit CHMP2B were recently associated with frontotemporal dementia and amyotrophic lateral sclerosis (ALS), neurodegenerative diseases characterized by abnormal ubiquitin-positive protein deposits in affected neurons. We show here that autophagic degradation is inhibited in cells depleted of ESCRT subunits and in cells expressing CHMP2B mutants, leading to accumulation of protein aggregates containing ubiquitinated proteins, p62 and Alfy. Moreover, we find that functional MVBs are required for clearance of TDP-43 (identified as the major ubiquitinated protein in ALS and frontotemporal lobar degeneration with ubiquitin deposits), and of expanded polyglutamine aggregates associated with Huntington's disease. Together, our data indicate that efficient autophagic degradation requires functional MVBs and provide a possible explanation to the observed neurodegenerative phenotype seen in patients with CHMP2B mutations.
Also flagged:glyceraldehyde-3-phosphate dehydrogenaseGAPDHpolyglutaminepolyprolinelocalizationamino acids
Journal Article2007-11-01✓ 5 SnippetsWu J, Lin F, Qin Z.
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Abstract)
…These results suggest that the polyQ domain, but not the polyP domain, plays a role in the sequestration of GAPDH to aggregates by mutant htt.…
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…htt in Huntington's disease…
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…htt (1-969 amino acids) with 100Q and 46Q (htt1-969-100Q and httl-969-46Q, mutant htt) in human mammary gland carcinoma…
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…of mutant huntingtin (htt) and GAPDH.…
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…Overexpression of N-terminalhtt(1-969 amino acids)…
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Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been reported to interact with proteins containing the polyglutamine (polyQ) domain. The present study was undertaken to evaluate the potential contributions of the polyQ and polyproline (polyP) domains to the co-localization of mutant huntingtin (htt) and GAPDH. Overexpression of N-terminal htt (1-969 amino acids) with 100Q and 46Q (htt1-969-100Q and httl-969-46Q, mutant htt) in human mammary gland carcinoma MCF-7 cells formed more htt aggregates than that of htt1-969-18Q (wild-type htt). The co-localization of GAPDH with htt aggregates was found in the cells expressing mutant but not wild-type htt. Deletion of the polyP region in the N-terminal htt had no effect on the co-localization of GAPDH and mutant htt aggregates. These results suggest that the polyQ domain, but not the polyP domain, plays a role in the sequestration of GAPDH to aggregates by mutant htt. This effect might contribute to the dysfunction of neurons caused by mutant htt in Huntington's disease.
Also flagged:colorectal cancercancergene expressionangiogenesiscell growthliver metastases
Journal Article2007-11-01✓ 1 SnippetNadal C, Maurel J, Gascon P.
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Even though liver metastasis accounts for the vast majority of cancer deaths in patients with colorectal cancer (CRC), fundamental questions about the molecular and cellular mechanisms of liver metastasis still remain unanswered. Determination of gene expression profiles by microarray technology has improved our knowledge of CRC molecular pathways. However, defined gene signatures are highly variable among studies. Expression profiles and molecular markers have been specifically linked to liver metastases mechanistic paths in CRC. However, to date, none of the identified signatures or molecular markers has been successfully validated as a diagnostic or prognostic tool applicable to routine clinical practice. To obtain a genetic signature for liver metastasis in CRC, measures to improve reproducibility, to increase consistency, and to validate results need to be implemented. Alternatives to expression profiling with microarray technology are continuing to be used. In the recent past, many genes codifying for proteins that are directly or indirectly involved in adhesion, invasion, angiogenesis, survival and cell growth have been linked to mechanisms of liver metastases in CRC.
Also flagged:heme oxygenase-1irontype 2 diabetes mellitustype 2 diabetesHeme oxygenase(HO) 1
Journal Article2007-11-01✓ 1 SnippetArredondo M, Jorquera D, Carrasco E, Albala C, Hertrampf E.
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Abstract)
…in persons withhemochromatosis.…
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<h4>Background</h4>High iron stores are known to cause type 2 diabetes mellitus in persons with hemochromatosis. However, it is not clear whether moderately elevated iron stores predict the risk of type 2 diabetes in healthy persons. Heme oxygenase (HO) 1 expression is increased when intracellular iron increases. Furthermore, HO shows a microsatellite polymorphism in its gene promoter that could be related to its expression and activity.<h4>Objectives</h4>We aimed to determine the length of (GT)(n) repeats in the HO1 gene promoter by using capillary electrophoresis and HO enzymatic activity in mononuclear cells (MNCs) from adult diabetes patients. We also aimed to assess the relation between these results and iron stores.<h4>Design</h4>We studied 99 patients with type 2 diabetes mellitus and 90 nondiabetic (control) subjects. We determined iron status (serum iron, ferritin, and transferrin receptor), HO activity, and micropolymorphism.<h4>Results</h4>One diabetes patient and 5 control subjects had iron deficiency anemia. No iron overload was detected in either group. Diabetes patients had significantly greater iron stores (P < 0.0001), total body iron (P < 0.001), and HO activity (P < 0.001) than did control subjects. A positive association between serum iron and HO activity was seen in the diabetes patients (P < 0.0001). Allelic frequency did not differ significantly between diabetes patients and control subjects; however, the frequency of the SM genotype was significantly higher and that of the SS and MM genotypes was significantly lower in the diabetes patients than in control subjects (P < 0.001 for all).<h4>Conclusions</h4>Type 2 diabetes patients carrying short (GT)(n) repeats may have higher ferritin values and greater HO enzymatic activity and may have greater susceptibility to diabetes than may those with long (GT)(n) repeats.
Olfactory ensheathing cells (OECs) and Schwann cells (SCs) obtained from adult transgenic rats expressing alkaline phosphatase (AP) were studied following implantation into intact spinal cord and after dorsal column crush (DCC) injury, either within the lesion or near the lesion borders. We observed no evidence of migration of AP OECs or AP SCs after lesion site injections, with most cells remaining in or nearby the injection/lesion site. Acute injection of either cell type outside of the lesion site resulted in the presence of cells in the lesion even two hours after injection. However, after a 2-week delay between DCC injury and cell injection, only OECs injected 2.5-mm outside of a DCC lesion entered the lesion, while SCs did not pass a region of increased astroglial immunoreactivity. GFAP-immunoreactivity also revealed differences in the astroglial scar at the lesion border with openings apparent in this region only in the OEC group. SCs induced greater ingrowth of CGRP-positive axons within the lesion, two weeks post-injury. Equivalent numbers of GAP-43-positive axons grew within the lesion after SC or OEC implantation. These findings show that, although there is no active migration for either cell type, both OECs and SCs are able to support axonal regrowth and/or sprouting into the lesion. The openings in the astroglial boundary at the lesion site may give OECs a potential advantage over SCs in promoting axonal growth through the astroglial scar.
Also flagged:serotonin transporterborderline personality disorderaffective instabilityanxietyneuroticism5
Journal Article2007-11-01✓ 2 SnippetsPascual JC, Soler J, Baiget M, Cortés A, Menoyo A, Barrachina J, Ropero M, Gomà M, Alvarez E, Perez V.
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Abstract)
…serotonin transporter gene (5-HTT) polymorphisms and some…
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…association between the5-HTTgene and some…
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<h4>Introduction</h4>The serotoninergic system seems to be implicated in characteristic symptoms of borderline personality disorder (BPD) such as affective instability, impulsivity or suicide. Some studies suggest an association between serotonin transporter gene (5-HTT) polymorphisms and some BPD symptoms. Short allele (S) of the 5-HTTLPR polymorphism in the promoter region has been shown to be associated with impulsivity, aggressive behavior, anxiety and neuroticism. Of the variable number of tandem repeat (VNTR) polymorphism in intron 2, BPD patients showed higher frequencies of the allele with the 10 repeats. The aim of this study was to determine the association between 5- HTTLPR and VNTR polymorphism of 5-HTT and personality traits in borderline personality disorder.<h4>Method</h4>A total of 65 BPD patients diagnosed by means of semi-structured interviews SCID-II and DIB-R were included. Two common polymorphisms of 5-HTT were genotyped: the 5-HTTLPR in the promoter region and VNTR in intron 2. Personality traits were assessed by the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ).<h4>Results</h4>Patients with L allele (L/S or L/L) in the 5-HTTLPR polymorphism showed lower scores on the subscale of liking parties and friends. Patients with the allele with 10 repeat of the VNTR polymorphism, showed lower scores in impulsivity, sensation seeking and in the subscale liking of parties and friends.<h4>Conclusions</h4>The results suggest a significant association between the 5-HTT gene and some personality traits in BPD. This gene may play a role in the etiology of borderline personality disorder.
Also flagged:ironhereditary hemochromatosisHHoverload
Journal Article2007-11-01✓ 4 SnippetsWalker AP, Tucker DC, Hall MA, Lohman K, Harrison H, Harrison BW, Reiss J, Acton RT, Adams PC, Diaz S, Holup J, Thomson E, Ellis SD, McLaren CE, Hemochromatosis and Iron Overload Study Research Investigators.
In-Text Gene Mentions
Abstract)
…We assessed the effectiveness of educational interventions for conveying clinical findings and information about hereditary hemochromatosis (HH) and iron overload (IO) to individuals evaluated clinically after initial screening for HH/IO with serum ferritin (SF) concentration, transferrin saturation (TS), and HFE genotyping.…
Abstract)
…hereditary hemochromatosis (HH) and iron overload (IO) to individuals evaluated clinically after initial screening for HH/IO with serum ferritin (SF) concentration, transferrin saturation (TS), and HFE…
Title)
…screening for possiblehemochromatosisand iron overload:…
<h4>Purpose</h4>We assessed the effectiveness of educational interventions for conveying clinical findings and information about hereditary hemochromatosis (HH) and iron overload (IO) to individuals evaluated clinically after initial screening for HH/IO with serum ferritin (SF) concentration, transferrin saturation (TS), and HFE genotyping.<h4>Methods</h4>A questionnaire mailed to 2300 cases and controls 1 month after a letter summarizing clinical findings measured understanding of results and recommendations, knowledge of HH/IO, and satisfaction with information received.<h4>Results</h4>Of 1622 (70.5%) participants completing relevant items, 83.6% were satisfied with receiving initial screening results by mail, 93.4% found information clear and easy to understand, 89.2% generally felt they got enough information, but 47.5% still had questions. C282Y/C282Y homozygosity with normal TS/SF predicted the best understanding of genetic results. Many with no mutations thought relatives were at risk. Iron levels created most confusion, and a third incorrectly recalled treatment recommendations. Having any abnormal result, lower education, older age, and being non-white, and/or non-English speaking predicted lower understanding.<h4>Conclusions</h4>Combining genotypic and phenotypic screening for HH/IO creates additional difficulties in communicating results-particularly to those with low health literacy. Explaining aberrant iron TS and SF levels and low-risk genotypes, follow-up recommendations, and risk to relatives will need creative, culturally appropriate strategies.
Site-1 protease (S1P) has an essential function in the conversion of latent, membrane-bound transcription factors to their free, active form. In mammals, abundant expression of S1P in chondrocytes suggests an involvement in chondrocyte function. To determine the requirement of S1P in cartilage and bone development, we have created cartilage-specific S1P knockout mice (S1P(cko)). S1P(cko) mice exhibit chondrodysplasia and a complete lack of endochondral ossification even though Runx2 expression, Indian hedgehog signaling, and osteoblastogenesis is intact. However, there is a substantial increase in chondrocyte apoptosis in the cartilage of S1P(cko) mice. Extraction of type II collagen is substantially lower from S1P(cko) cartilage. In S1P(cko) mice, the collagen network is disorganized and collagen becomes entrapped in chondrocytes. Ultrastructural analysis reveals that the endoplasmic reticulum (ER) in S1P(cko) chondrocytes is engorged and fragmented in a manner characteristic of severe ER stress. These data suggest that S1P activity is necessary for a specialized ER stress response required by chondrocytes for the genesis of normal cartilage and thus endochondral ossification.
Also flagged:Peroxiredoxin 6wound healingoxygendiabetescancersteroids
Journal Article2007-11-01✓ 5 SnippetsKümin A, Schäfer M, Epp N, Bugnon P, Born-Berclaz C, Oxenius A, Klippel A, Bloch W, Werner S.
In-Text Gene Mentions
S I O 001029)
…Collectively, this in vivo experiment revealed that the presence of Prdx6 is required in inflammatory cells as well as in resident cells for blood vessel integrity in wounded skin (shown schematically in Fig.…
S I O 001029)
…Endothelial cell damage in 5-d wounds of Prdx6 knockout mice. Methylene-blue stained, semi-thin sections (A and B) and electron micrographs of newly formed blood vessels (C–F) from 5-d wounds of control (A and C) and Prdx6 knockout mice (B, D, E, and F) are shown.…
Introduction)
…By contrast, Prdx6—also designated 1-Cys-peroxiredoxin—has only a single redox-active cysteine (Manevich and Fisher, 2005).…
Discussion)
…This suggests that Prdx6 may also be required for blood vessel integrity in other situations of inflammation-associated angiogenesis, in particular in cancer.…
Abstract)
…Peroxiredoxin 6 (Prdx6) is a cytoprotective…
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Peroxiredoxin 6 (Prdx6) is a cytoprotective enzyme with largely unknown in vivo functions. Here, we use Prdx6 knockout mice to determine its role in UV protection and wound healing. UV-mediated keratinocyte apoptosis is enhanced in Prdx6-deficient mice. Upon skin injury, we observe a severe hemorrhage in the granulation tissue of knockout animals, which correlates with the extent of oxidative stress. At the ultrastructural level endothelial cells appear highly damaged, and their rate of apoptosis is enhanced. Knock-down of Prdx6 in cultured endothelial cells also increases their susceptibility to oxidative stress, thus confirming the sensitivity of this cell type to loss of Prdx6. Wound healing studies in bone marrow chimeric mice demonstrate that Prdx6-deficient inflammatory and endothelial cells contribute to the hemorrhage phenotype. These results provide insight into the cross-talk between hematopoietic and resident cells at the wound site and the role of reactive oxygen species in this interplay.
…dosage compensation complex (DCC) mediates the twofold…
Abstract)
…mutations at anyDCCprotein-coding gene are…
Abstract)
…the five coreDCCproteins—MSL1, MSL2, MSL3,…
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Dosage compensation refers to the equalization of X-linked gene transcription among heterogametic and homogametic sexes. In Drosophila, the dosage compensation complex (DCC) mediates the twofold hypertranscription of the single male X chromosome. Loss-of-function mutations at any DCC protein-coding gene are male lethal. Here we report a population genetic analysis suggesting that four of the five core DCC proteins--MSL1, MSL2, MSL3, and MOF--are evolving under positive selection in D. melanogaster. Within these four proteins, several domains that range in function from X chromosome localization to protein-protein interactions have elevated, D. melanogaster-specific, amino acid divergence.
…Down-regulatedSERPINC1and SERPINE1 were parts of interleukin signaling, the former regulated IL6 and the latter regulated by IL1B .…
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<h4>Background</h4>To better understand the response of urinary epithelial (urothelial) cells to Enterococcus faecalis, a uropathogen that exhibits resistance to multiple antibiotics, a genome-wide scan of gene expression was obtained as a time series from urothelial cells growing as a layered 3-dimensional culture similar to normal urothelium. We herein describe a novel means of analysis that is based on deconvolution of gene variability into technical and biological components.<h4>Results</h4>Analysis of the expression of 21,521 genes from 30 minutes to 10 hours post infection, showed 9553 genes were expressed 3 standard deviations (SD) above the system zero-point noise in at least 1 time point. The asymmetric distribution of relative variances of the expressed genes was deconvoluted into technical variation (with a 6.5% relative SD) and biological variation components (>3 SD above the mode technical variability). These 1409 hypervariable (HV) genes encapsulated the effect of infection on gene expression. Pathway analysis of the HV genes revealed an orchestrated response to infection in which early events included initiation of immune response, cytoskeletal rearrangement and cell signaling followed at the end by apoptosis and shutting down cell metabolism. The number of poorly annotated genes in the earliest time points suggests heretofore unknown processes likely also are involved.<h4>Conclusion</h4>Enterococcus infection produced an orchestrated response by the host cells involving several pathways and transcription factors that potentially drive these pathways. The early time points potentially identify novel targets for enhancing the host response. These approaches combine rigorous statistical principles with a biological context and are readily applied by biologists.
Also flagged:Serotonin transporterAlzheimer's diseaseADdementiaApolipoprotein EBPSD
Journal Article2007-11-01✓ 4 SnippetsUeki A, Ueno H, Sato N, Shinjo H, Morita Y.
In-Text Gene Mentions
Abstract)
…Apolipoprotein E (ApoE) gene polymorphism and 2 types of functional polymorphism in the 5-HTT gene, 5-HTT-linked polymorphic region (5-HTTLPR) and a 5-HTT variable number of tandem repeats sequence (5-HTTVNTR) were analyzed longitudinally in outpatients with mild AD to find out whether there was a relation between any such polymorphisms and the occurrence of BPSD.…
Abstract)
…Conversely, 5-HTTVNTR influences the risk of developing BPSD or aggressiveness and genetic variations in the 5-HTT gene may be involved in the development of symptomatology for mild AD.…
Abstract)
…the serotonin transporter (5-HTT) gene with Alzheimer's…
Abstract)
…variations in the5-HTTgene may be…
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The purpose of the present study was to confirm an association of functional polymorphism within the serotonin transporter (5-HTT) gene with Alzheimer's disease (AD) and behavioral and psychological symptoms of dementia (BPSD) in mild AD. Apolipoprotein E (ApoE) gene polymorphism and 2 types of functional polymorphism in the 5-HTT gene, 5-HTT-linked polymorphic region (5-HTTLPR) and a 5-HTT variable number of tandem repeats sequence (5-HTTVNTR) were analyzed longitudinally in outpatients with mild AD to find out whether there was a relation between any such polymorphisms and the occurrence of BPSD. No significant differences in genotype distribution or allele frequencies were identified for 5-HTTLPR or 5-HTTVNTR between AD patients and age- and sex-matched non-demented controls regardless of ApoE epsilon4 allele. No significant differences were noted in 5-HTTLPR genotype or allele distributions between AD patients with or without BPSD. However, significant associations were observed between presence of 5-HTTVNTR allele 10 and BPSD or aggressiveness. This difference was independent of the presence of the ApoE epsilon4 allele. As a result, 5-HTT polymorphisms are unlikely to play any substantial role in susceptibility to AD. Conversely, 5-HTTVNTR influences the risk of developing BPSD or aggressiveness and genetic variations in the 5-HTT gene may be involved in the development of symptomatology for mild AD.
Also flagged:RoquinImmune responsesaco-stimulatory receptorinducible T-cell co-stimulatorICOSlupus
Journal Article2007-11-01✓ 5 SnippetsYu D, Tan AH, Hu X, Athanasopoulos V, Simpson N, Silva DG, Hutloff A, Giles KM, Leedman PJ, Lam KP, Goodnow CC, Vinuesa CG.
In-Text Gene Mentions
Abstract)
…In sanroque mice homozygous for an M199R mutation in the ROQ domain of Roquin (also known as Rc3h1), increased Icos expression on T cells causes the accumulation of lymphocytes that is associated with a lupus-like autoimmune syndrome.…
Abstract)
…Roquin (also known as Rc3h1), increased Icos expression on T cells causes the accumulation of lymphocytes that is associated with a lupus…
Abstract)
…Rc3h1), increased Icos expression on T cells causes the accumulation of lymphocytes that is associated with a lupus…
Abstract)
…Rc3h1), increased Icos expression on T cells causes the accumulation of lymphocytes that is associated with a lupus-like autoimmune syndrome…
Abstract)
…Roquin (also known as Rc3h1), increased Icos expression on T cells causes the accumulation of lymphocytes that is associated with a lupus-like autoimmune syndrome…
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Immune responses are normally targeted against microbial pathogens and not self-antigens by mechanisms that are only partly understood. Here we define a newly discovered pathway that prevents autoimmunity by limiting the levels on T lymphocytes of aco-stimulatory receptor, the inducible T-cell co-stimulator(ICOS). In sanroque mice homozygous for an M199R mutation in the ROQ domain of Roquin (also known as Rc3h1), increased Icos expression on T cells causes the accumulation of lymphocytes that is associated with a lupus-like autoimmune syndrome. Roquin normally limits Icos expression by promoting the degradation of Icos messenger RNA.A conserved segment in the unusually long ICOS 3' untranslated mRNA is essential for regulation by Roquin. This segment comprises a 47-base-pair minimal region complementary to T-cell-expressed microRNAs including miR-101, the repressive activity of which is disrupted by base-pair inversions predicted to abrogate miR-101 binding. These findings illuminate a critical post-transcriptional pathway within T cells that regulates lymphocyte accumulation and autoimmunity, and highlights the therapeutic potential of partially antagonising the ICOS pathway.
<h4>Objective</h4>To study the changes of blood coagulative and fibrinolytic system and the function of pulmonary vascular endothelium in the course of acute pulmonary thromboembolism (PTE) and after anticoagulant or thrombolytic treatment.<h4>Methods</h4>Twenty patients with acute non-massive PTE, 10 males and 10 females, aged (57 +/- 11) underwent anticoagulant treatment and 17 sex-, and age-matched acute massive PTE patients underwent thrombolytic treatment. The plasma level of D-dimer (D-D), thrombomodulin (TM), protein C (PC), protein S (PS), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), and antithrombin-III (AT-III) activity were measured by ELISA before and after normal subjects severed as control group were included in the study. The plasma level of D-D, PS, PC, TM, t-PA and PAI-1 were measured by a method of ELISA before the treatment and six days after the anticoagulant treatment or 24 hours after the thrombolytic treatment. AT-III activity was measured by chromo-substrate method at the same time points. Forty sex- and age-matched healthy persons were used as controls.<h4>Results</h4>The plasma levels of D-D, t-PA, PS, and TM level of the anticoagulant group were all significantly higher and the AT-III activity of the 2 treatment groups was significantly lower than those of the controls before treatment (all P < 0.05); the plasma levels of D-D, t-PA, PAI-1, PS, and TM of the thrombolytic group were ala significantly higher and the AT-III activity was significantly lower than those of the control group before the treatment (all P < 0.05). After anticoagulant therapy, the plasma levels of D-D, t-PA, PS, and PC were significantly lower than those before treatment (all P < 0.05), however, the plasma levels of PAI-1, TM, and AT-III activity after treatment did not differ significantly from those before treatment. The plasma levels of D-D, t-PA, PS, PC, and TM after treatment of the thrombolytic group were all significantly lower than those before treatment (all P < 0.05), however, the plasma levels of PAI-1, TM, and AT-III activity after treatment did not differ significantly from those before treatment.<h4>Conclusion</h4>Apparent imbalance in the blood coagulative and fibrinolytic system and pulmonary vascular endothelium damage occur in the patients with acute PTE. Combination tests of plasma D-D, AT-III, PS, PC, TM, t-PA and PAI-1 can give a more comprehensive explanation of the imbalance in the blood coagulative and fibrolytic system. Anticoagulant treatment and thrombolytic treatment play important roles in the regulation of the imbalance of coagulative and fibrinolytic system and protection of the function of pulmonary vascular endothelium of PTE patients.
Also flagged:NAFLDsteatohepatitiscirrhosisalcoholliver diseasehepatocellular carcinoma
Journal Article2007-11-01✓ 1 SnippetKarnikowski M, Córdova C, Oliveira RJ, Karnikowski MG, Nóbrega Ode T.
In-Text Gene Mentions
Methods)
…diagnoses of cirrhosis,hemochromatosisor any congenital…
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<h4>Context and objectives</h4>Non-alcoholic fatty liver disease (NAFLD) is a complex clinicopathological entity characterized by diffuse or focal fat accumulation in the hepatic parenchyma of patients who deny abusive alcohol consumption. This study aimed to assess idiopathic NAFLD in community-dwelling, middle-aged and older adults living in the Brazilian Federal District. Associations between NAFLD and components of metabolic syndrome and the whole syndrome were investigated.<h4>Design and settings</h4>This was a cross-sectional study on 139 subjects aged 55 years or older.<h4>Methods</h4>NAFLD was diagnosed by means of clinical procedures, to exclude subjects with signs of liver disorders, abusive alcohol consumption and influence from hepatotoxic drugs. Phenotypes were graded based on ultrasound examination. Metabolic syndrome was defined using the NCEP ATP III criteria. Laboratory tests were performed to assist clinical examinations and define the syndrome. RESULTS NAFLD was present in 35.2% of the subjects. Taken together, the two most intense phenotypes correlated with increased serum fasting glucose, triglyceride and VLDL cholesterol levels. Metabolic syndrome was diagnosed in 25.9% of the sample. In addition to associating NAFLD with specific traits of metabolic syndrome, non-parametric analysis confirmed the existence of a relationship (p < 0.05) between the steatotic manifestation and the syndromic condition.<h4>Conclusion</h4>Compared with the literature, this study reveals greater frequency of idiopathic NAFLD among Brazilian middle-aged and older adults than is described elsewhere. The findings also suggest that impaired glycemic metabolism coupled with increased fat delivery and/or sustained endogenous biosynthesis is the most likely physiopathogenic mechanisms underlying the onset of NAFLD in this population.
Colorectal cancer (CRC) is the third most commonly diagnosed cancer in both men and women in the United States, with an estimated 153,760 new cases predicted for 2007. Since the 1960s, 5-fluorouracil (5-FU) has remained the mainstay of therapeutic options in the treatment of advanced CRC, with response rates of 20% to 25%. The introduction of newer agents such as oxaliplatin and irinotecan in combination with 5-FU has increased response rates to 40% to 50% in advanced disease and improved overall survival. The development of monoclonal antibodies targeting the epidermal growth factor receptor or vascular endothelial growth factor has demonstrated additional clinical benefit for patients with metastatic disease. However, many patients succumb to their disease, and a significant proportion will experience severe chemotherapy-associated toxicities while deriving little or no benefit. To improve the treatment of CRC, efforts must be directed toward the identification of patients who are likely to respond to a specific therapy, those who will experience severe toxicities, and those who will benefit from chemotherapy in the adjuvant setting. However, the utility of individual markers of response, toxicity, and disease recurrence remains in question. Efforts are now under way to develop multimarker profiles that can more accurately predict disease response. In this review, we discuss both predictive and prognostic markers identified in the treatment of CRC in terms of their robustness and their ability to assist the clinician in developing the most efficacious and least toxic therapeutic strategy for each patient.