Neuroendocrine (NE) cells use large dense core vesicles (LDCVs) to traffic, process, store and secrete neuropeptide hormones through the regulated secretory pathway. The DIMM basic helix-loop-helix transcription factor of Drosophila controls the level of regulated secretory activity in NE cells. To pursue its mechanisms, we have performed two independent genome-wide analyses of DIMM's activities: (i) in vivo chromatin immunoprecipitation (ChIP) to define genomic sites of DIMM occupancy and (ii) deep sequencing of purified DIMM neurons to characterize their transcriptional profile. By this combined approach, we showed that DIMM binds to conserved E-boxes in enhancers of 212 genes whose expression is enriched in DIMM-expressing NE cells. DIMM binds preferentially to certain E-boxes within first introns of specific gene isoforms. Statistical machine learning revealed that flanking regions of putative DIMM binding sites contribute to its DNA binding specificity. DIMM's transcriptional repertoire features at least 20 LDCV constituents. In addition, DIMM notably targets the pro-secretory transcription factor, CREB-A, but significantly, DIMM does not target any neuropeptide genes. DIMM therefore prescribes the scale of secretory activity in NE neurons, by a systematic control of the regulated secretory pathway at steps that are both proximal and distal.
Genome-wide features of neuroendocrine regulation in Drosophila by the basic helix-loop-helix transcription factor DIMMED.
Sex, Specimen part
View SamplesEmploying microarray assays, a total of 267 genes were identified that were significantly up- or downregulated in PBMCs of WT-NOD2 patients, compared to healthy donors after challenge with vitamin D (+/-D) and/or a combination (+/-LP) of LPS (lipopolysaccharide) and PGN (peptidoglycan) (p < 0.05; threshold: 2-fold change). For further analysis by real-time PCR, 12 genes with known impact on inflammation and immunity were selected that fulfilled predefined expression criteria. In a larger cohort of patients and controls, a disease-associated expression pattern, with higher transcript levels in vitamin D-treated PBMCs from 5 patients, was observed for three of these genes, CLEC5A (p < 0.030), lysozyme (LYZ; p < 0.047) and TREM1 (p < 0.023). Six genes were found to be expressed in a NOD2- dependent manner (CD101, p < 0.002; CLEC5A, p < 0.020; CXCL5, p < 0.009; IL-24, p < 0.044; ITGB2, p < 0.041; LYZ, p < 0.042). Interestingly, the highest transcript levels were observed in patients with heterozygous NOD2 mutations.
<i>NOD2</i>- and disease-specific gene expression profiles of peripheral blood mononuclear cells from Crohn's disease patients.
Specimen part, Disease, Disease stage, Treatment
View SamplesLipid mobilization (lipolysis) in white adipose tissue (WAT) critically controls lipid turnover and adiposity in humans. While the acute regulation of lipolysis has been studied in detail, the transcriptional determinants of WAT lipolytic activity remain still largely unexplored. Here we show that the genetic inactivation of transcriptional co-factor transducin beta-like-related (TBLR) 1 blunts the lipolytic response of white adipocytes through the impairment of cAMP-dependent signal transduction. Indeed, mice lacking TBLR1 in adipocytes are defective in fasting-induced lipid mobilization and when placed on a high fat diet show aggravated adiposity, glucose intolerance and insulin resistance. TBLR1 levels are found to increase under lipolytic conditions in WAT of both human patients and mice, correlating with serum free fatty acids (FFA). As a critical regulator of WAT cAMP signaling and lipid mobilization, proper activity of TBLR1 in adipocytes may thus represent a critical molecular checkpoint for the prevention of metabolic dysfunction in subjects with obesity-related disorders.
Transcriptional cofactor TBLR1 controls lipid mobilization in white adipose tissue.
Specimen part, Treatment
View SamplesTo explore the molecular basis for TSC22D4 function in hepatic lipid homeostasis in vivo TSC22D4 was knocked down in the mouse liver using adenovirus and performed genome wide expression analysis.
TSC22D4 is a molecular output of hepatic wasting metabolism.
Specimen part
View SamplesLung cancer is a leading cause of deaths in the world. There is a need to improve an understanding of mechanisms of malignant transformation and to develop genetic markers of disease for better and targeted therapies.
Cancer genomics identifies regulatory gene networks associated with the transition from dysplasia to advanced lung adenocarcinomas induced by c-Raf-1.
No sample metadata fields
View SamplesBackground and Aims: Analysis of aging-induced impairments in satellite cells (SCs) – the stem cells of skeletal muscle that are required for its regeneration. Hox genes are known to control stem cell function and development of various tissues. Overall design: Hindlimb muscles from young adult (3-4 months) and old (22-28 months) C57BL/6J mice were injured by BaCl2 injection in order to induce satellite cell activation. Satellite cells were isolated 3 days after injury and gene expression was analyzed.
Epigenetic stress responses induce muscle stem-cell ageing by Hoxa9 developmental signals.
Specimen part, Cell line, Subject
View SamplesAdaptation of C. elegans to hypertonic environments involves the accumulation of the organic osmolyte glycerol via transcriptional upregulation of the glycerol biosynthestic enzyme gpdh-1. A number of mutants, termed osmotic stress resistant (osr) mutants, have been identified. osr mutants cause constitutive upregulation of gpdh-1 and confer extreme resistance to hypertonicity. We tested the hypothesis that osr mutants broadly activate a gene expression program normally activated by osmotic stress in wild type animals using Affymterix microarray analysis of the hypertonic stress response in wild type animals and of constituitive gene expression changes in five osr mutants.
Genetic and physiological activation of osmosensitive gene expression mimics transcriptional signatures of pathogen infection in C. elegans.
Specimen part
View SamplesInsulators are DNA elements, which prevent inappropriate interactions between the neighboring regions of the genome. They can be functionally classified as either enhancer blockers or domain barriers. CTCF (CCCTC binding factor) is the only known major insulator binding protein in the vertebrates and has been shown to bind many enhancer-blocking elements. However, it is not clear whether it plays a role in chromatin domain barriers between active and repressive domains. Here, we used ChIP-Seq to map the genome-wide binding sites of CTCF in three cell types and identified significant binding of CTCF to the boundaries of repressive chromatin domains marked by H3K27me3. Although we find an extensive overlapping of CTCF binding sites across the three cell types, its association with the domain boundaries is cell type-specific. We further show that the nucleosomes flanking CTCF binding sites are well positioned and associated with histone H2AK5 acetylation (H2AK5ac). Interestingly, we found a complementary pattern between the repressive H3K27me3 and the active H2AK5ac regions, which are separated by CTCF. Our findings indicate that CTCF may play important roles in the barrier activity of insulators and provide a resource for further investigation of the CTCF function in organizing chromatin in the human genome.
Global analysis of the insulator binding protein CTCF in chromatin barrier regions reveals demarcation of active and repressive domains.
No sample metadata fields
View SamplesBackground: Information on the carcinogenic potential of chemicals is only availably for High Production Volume products. There is however, a pressing need for alternative methods allowing for the chronic toxicity of substances, including carcinogenicity, to be detected earlier and more reliably. Here we applied advanced genomics to a cellular transformation assay to identify gene signatures useful for the prediction of risk for carcinogenicity. Methods: Genome wide gene expression analysis and qRT-PCR were applied to untransformed and transformed Balb/c 3T3 cells that exposed to 2, 4-diaminotoluene (DAT), benzo(a)pyrene (BaP), 2-Acetylaminoflourene (AAF) and 3-methycholanthrene (MCA) for 24h and 120h, at different concentrations, respectively. Furthermore, various bioinformatics tools were used to identify gene signatures predicting for the carcinogenic risk. Results: Bioinformatics analysis revealed distinct datasets for the individual chemicals tested while the number of significantly regulated genes increased with ascending treatment concentration of the cell cultures. Filtering of the data revealed a common gene signature that comprised of 13 genes whose regulation in cancer tissue has already been established. Strikingly, this gene signature was already identified prior to cell transformation therefore confirming the predictive power of this gene signature in identifying carcinogenic risks of chemicals. Comparison of fold changes determined by microarray analysis and qRT-PCR were in good agreement. Conclusion: Our data describes selective and commonly regulated carcinogenic pathways observed in an easy to use in vitro carcinogenicity assay. Here we defined a set of genes which can serve as a simply assay to predict the risk for carcinogenicity by use of an alternative in vitro testing strategy.
Toxicogenomics applied to in vitro carcinogenicity testing with Balb/c 3T3 cells revealed a gene signature predictive of chemical carcinogens.
Cell line, Treatment, Time
View SamplesAlthough mast cells elicit proinflammatory and type I IFN responses upon VSV infection, in response to L.monocytogenes (L.m) or S. Typhimurium (S.t), such cells elicit a transcriptional program devoid of type I IFN response.
Mast cells elicit proinflammatory but not type I interferon responses upon activation of TLRs by bacteria.
Specimen part
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