Chromatin-based functional genomic analyses and genomewide association studies (GWASs) together implicate enhancers as critical elements influencing gene expression and risk for common diseases. Here, we performed systematic chromatin and transcriptome profiling in human pancreatic islets. Integrated analysis of islet data with those generated by the ENCODE project in nine cell types identified specific and significant enrichment of type 2 diabetes and related quantitative trait GWAS variants in islet enhancers. Our integrated chromatin maps reveal that most enhancers are short (median = 0.8 kb). Each cell type also contains a substantial number of more extended (=3 kb) enhancers. Interestingly, these stretch enhancers are often tissue-specific and overlap locus control regions, suggesting that they are important chromatin regulatory beacons. Indeed, we show that (i) tissue specificity of enhancers and nearby gene expression increase with enhancer length; (ii) neighborhoods containing stretch enhancers are enriched for important cell type-specific genes; and (iii) GWAS variants associated with traits relevant to a particular cell type are more enriched in stretch enhancers compared with short enhancers. Reporter constructs containing stretch enhancer sequences exhibited tissue-specific activity in cell culture experiments and in transgenic mice. These results suggest that stretch enhancers are critical chromatin elements for coordinating cell type-specific regulatory programs and that sequence variation in stretch enhancers affects risk of major common human diseases. Overall design: Integrated analysis of islet chromatin modification and transcriptome data with those generated by the ENCODE project. NISC Comparative Sequencing Program
Chromatin stretch enhancer states drive cell-specific gene regulation and harbor human disease risk variants.
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View SamplesOne of our new major finding among the genes that contributes to MS susceptibility is ICSBP1. The so called disease modifying therapies like interferon-beta (IFN-), possibly acting on the peripheral T-cells, reduce the disease activity and the clinical progression, with a MRI-detectable effect in preventing lesion burden and cerebral atrophy development in RR-MS. It suggests a critical role of peripheral blood mononuclear cells (PBMCs) immune response and modulation in developing inflammation in the brain. We tested the hypothesis that the genetic effect of the susceptible allele ICSBP1 can impact the gene expression profile of molecules belonging to the interferon pathway. We therefore interrogated the PBMC for changes in gene expression profile. We correlate those changes with the minor allele frequency for ICSBP1, performing independent quantitative trait analysis for each treatment category. Expression Quantitative Trait Loci Association with a p value < 0.05 have been used in follow up analysis. The regression coefficient of the Quantitative trait association represents the degree of correlation between the gene expression for each interrogated target gene and the minor allele frequency of the SNP for our gene of interest. This coefficient has been used as input in the subsequent Gene Set Enrichment Analysis performed in a pre-ranked approach. The resulting GSEA-SNP method rests on the assumption that SNPs underlying a disease phenotype might affect genes constituting a signaling pathway or genes with a common regulation. Therefore, GSEA-SNP can facilitate the identification of pathways or of underlying biological mechanisms.
Meta-analysis of genome scans and replication identify CD6, IRF8 and TNFRSF1A as new multiple sclerosis susceptibility loci.
Specimen part
View SamplesGene expression profiling of three PEL cell lines compare to three Burkitt's lymphoma lines to figure out the changed genes under KSHV latent infection.
The latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus modulates cellular gene expression and protects lymphoid cells from p16 INK4A-induced cell cycle arrest.
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View SamplesIdentification of TLR4 as one of the most abundant RNA species in pericytes with respect to MSC, and corroboration of TLR4 expression on the cell surface, led us to obtain a comprehensive overview of the expression program of lipopolysaccharide (LPS) stimulated pericytes. Microarray analyisis demonstrated the significant upregulation of 76 annotated genes including transcripts for adhesion molecules, inflammation mediators, pro-angiogenic factors, transcription factors and anti-apoptotic proteins.
Lipopolysaccharide activates Toll-like receptor 4 (TLR4)-mediated NF-κB signaling pathway and proinflammatory response in human pericytes.
Specimen part, Treatment
View SamplesPericytes and mesenchymal stem cells (MSC) are ontogenically related, and in fact no phenotypic differences were observed by flow cytometry using a panel of surface antigen markers. Global gene expression profiles of human pericytes and MSC revealed that 43 genes were expressed more than 10 fold in pericytes as compared to MSC.
Lipopolysaccharide activates Toll-like receptor 4 (TLR4)-mediated NF-κB signaling pathway and proinflammatory response in human pericytes.
Specimen part
View SamplesAnalysis of rice leaves (V2 stage) in response to a short treatment with very high CO2 concentration in the dark, using standard atmosphere as control.
High CO2 concentration as an inductor agent to drive production of recombinant phytotoxic antimicrobial peptides in plant biofactories.
Specimen part, Treatment
View SamplesPineal function follows a 24-hour schedule, dedicated to the conversion of night and day into a hormonal signal, melatonin. In mammals, 24-hour changes in pineal activity are controlled by a neural pathway that includes the central circadian oscillator in the suprachiasmatic nucleus and the superior cervical ganglia (SCG), which innervate the pineal gland. In this study, we have generated the first next-generation RNA sequencing evidence of neural control of the daily changes in the pineal transcriptome. We found over 3000 pineal transcripts that are differentially expressed (p <0.001) on a night/day basis (70% of these genes increase at night, 376 with fold change >4 or <1/4), the majority of which had not been previously identified as such. Nearly all night/day differences were eliminated by neonatal removal or decentralization of the SCG, confirming the importance of neural input for differential night/day changes in transcript abundance. In contrast, very few non-rhythmic genes showed evidence of changes in expression due to the surgical procedure itself, which is consistent with the hypothesis that post neonatal neural stimulation is not required for cell fate determination and maintenance of phenotype. Many of the transcripts that exhibit marked differential night/day expression exhibited similar changes in response to in vitro treatment with norepinephrine, the SCG neurotransmitter which mediates pineal regulation. Similar changes were also seen following treatment with an analog of the norepinephrine second messenger, cyclic AMP. Overall design: For the in vivo data, there were 8 biological conditions: day and night time points for each of four surgical groups: Control (Ctrl) Sham-surgery (Sham), Decentralized (DCN), and Ganglionectomized (SCGX). Samples were pooled into three biological replicates for each biological condition. For the in vitro data there were 3 biological conditions: Untreated control (CN), DBcAMP-treated (DB), and Norepinephrine-treated (NE). For the pineal enrichment comparison, three samples (i.e. no biological replicates) were used: pineal-day, pineal-night and mixed-tissue. For the mixed tissues sample, the following tissues from three rats sacrificed at ZT7 were used: cortex, cerebellum, midbrain, hypothalamus, hindbrain, spinal cord, retina, pituitary, heart, liver, lung, kidney, skeletal muscle, small intestine, adrenal gland. Total RNA was extracted from each tissue, and then equal amounts of each of the 15 tissues were combined for the final pooled sample.
Neurotranscriptomics: The Effects of Neonatal Stimulus Deprivation on the Rat Pineal Transcriptome.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Hypoxia-induced HIF1α targets in melanocytes reveal a molecular profile associated with poor melanoma prognosis.
Specimen part, Cell line
View SamplesThese datasets describe a melanocyte specific, HIF1A-Dependent / Hypoxia-Responsive gene expression signature defined by the regulation of genes critical to metabolism, chromatin and transcriptional regulation, vascularization and cellular invasivness. These genes provide lineage specific targets for refinement of diagnostic markers associated with primary melanoma tumor metastatic potential, and also provides novel molecular targets for therapeutic strategies targeting metastatic disease progression.
Hypoxia-induced HIF1α targets in melanocytes reveal a molecular profile associated with poor melanoma prognosis.
Specimen part, Cell line
View SamplesUnderstanding the molecular underpinnings of cancer is of critical importance to developing targeted intervention strategies. Identification of such targets, however, is notoriously difficult and unpredictable. Malignant cell transformation requires the cooperation of a few oncogenic mutations that cause substantial reorganization of many cell features and induce complex changes in gene expression patterns. Genes critical to this multi-faceted cellular phenotype thus only have been identified following signaling pathway analysis or on an ad hoc basis. Our observations that cell transformation by cooperating oncogenic lesions depends on synergistic modulation of downstream signaling circuitry suggest that malignant transformation is a highly cooperative process, involving synergy at multiple levels of regulation, including gene expression. Here we show that a large proportion of genes controlled synergistically by loss-of-function p53 and Ras activation are critical to the malignant state. Remarkably, 14 among 24 such 'cooperation response genes' (CRGs) were found to contribute to tumor formation in gene perturbation experiments. In contrast, only one in 14 perturbations of genes responding in a non-synergistic manner had a similar effect. Synergistic control of gene expression by oncogenic mutations thus emerges as an underlying key to malignancy and provides an attractive rationale for identifying intervention targets in gene networks downstream of oncogenic gain and loss-of-function mutations.
Synergistic response to oncogenic mutations defines gene class critical to cancer phenotype.
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