The activity of enhancers and promoters fine-tunes the transcriptional program of mammalian cells through the recruitment and interplay between cell type-specific and ubiquitous transcription factors. Despite their key role in modulating transcription, the identification of enhancers is challenged by their limited sequence conservation and highly variable distance from target genes. Although enhancers are characterised by the strong enrichment of mono-methylation at lysine 4 of histone H3, mirrored by low tri-methylation at the same residue, a comprehensive list of enhancers-associated histone post-translational modifications (PTMs) is still lacking. We undertook a proteomics investigation, based on chromatin immunoprecipitation combined with mass spectrometry (MS), to identify histone marks specifically associated to cis-regulatory elements in macrophages, focusing on enhancers. We also profiled their plasticity during the transcriptional activation induced by an inflammatory stimulus. The proteomic analysis suggested novel PTM associations, which were validated by analysis of ChIP- and RNA-seq data, whose intersection revealed the existence of novel sub-populations of enhancers marked by specific signatures: the dual mark H3K4me1/K36me2 labels transcription at enhancers, whereas H3K4me1/K36me3 and H3K4me1/K79me2 tag distinct intronic enhancers. While demonstrating that analyzing restricted genomic regions can disclose the combinatorial language of histone modifications, this study highlights the potential of MS-based proteomics in addressing fundamental questions in epigenetics. Overall design: Total RNA was extracted from 5x10^6 untreated RAW 264.7 cells using RNAeasy kit (Qiagen). Libraries were then prepared using TruSeq RNA sample preparation Kit (Illumina) after depleting ribosomal RNA
Chromatin proteomics reveals novel combinatorial histone modification signatures that mark distinct subpopulations of macrophage enhancers.
Specimen part, Cell line, Treatment, Subject
View SamplesThe transcription factor STAT3 is constitutively activated in tumors of different origin but the molecular bases for STAT3 addiction of tumor cells have not yet been clearly identified. We generated knock/in mice carrying the constitutively active Stat3 allele, Stat3C, and showed that Stat3C could enhance Neu oncogenic power, triggering the production of earlier onset, more invasive mammary tumors. Tumor-derived cell lines displayed higher migration and invasion and disrupted distribution of cell-cell junction markers. The tensin family member Cten (C-Terminal Tensin-like), known to mediate EGF-induced migration and highly expressed in inflammatory breast cancer, was up-regulated in both Neu;Stat3C cells and tumors. Both Cten expression and enhanced migration were strictly dependent on Stat3, and Cten silencing normalized cell migration and rescued cell-cell contact defects. Importantly, the pro-inflammatory cytokine IL-6 could mediate Cten induction in MCF10 cells, in an exquisitely Stat3-dependent way. This model allowed us to shed some light on the oncogenic role of Stat3 in the breast, suggesting moreover a mechanism through which inflammatory signals can cooperate with EGF receptors in inflammatory breast cancer.
Constitutively active Stat3 enhances neu-mediated migration and metastasis in mammary tumors via upregulation of Cten.
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View SamplesG protein alpha q and 11 are mutated in 80% of uveal melanoma. We observed that treatment with the BRD4 inhibitor JQ1 resulted in different phenotypic responses in G-protein mutant uveal melanoma cell lines and wild type uveal melanoma cell lines.
BRD4-targeted therapy induces Myc-independent cytotoxicity in Gnaq/11-mutatant uveal melanoma cells.
Cell line, Treatment
View SamplesThe endogenous peptide Apelin is crucial for maintaining heart function in pressure overload and aging
Impaired heart contractility in Apelin gene-deficient mice associated with aging and pressure overload.
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View SamplesFour male SHR/Ola, BN and SHR-18 rats were fed a normal diet and sacrificed at 9 weeks of age. Four male SHR/Ola and SHR-18 rats at 8 weeks of age were fed 1% NaCl for one week and then sacrificed. Kidneys were removed and frozen in liquid nitrogen for all 20 animals. Total RNA was isolated, labelled cRNA was generated and hybridised to Affymetrix Rat RG-U34ABC arrays.
Dissection of chromosome 18 blood pressure and salt-sensitivity quantitative trait loci in the spontaneously hypertensive rat.
Sex, Age, Specimen part
View SamplesAnalysis of gene expression profile in peritoneal macrophage extracted from LPS or PBS challenged DUSP3-/- and WT mice. DUSP3 deletion protects mice from sepsis and endotoxemia. We performed a microarray analysis to get insights into the differentially regulated pathways between WT and KO under inflammatory conditions.
DUSP3 Genetic Deletion Confers M2-like Macrophage-Dependent Tolerance to Septic Shock.
Sex, Age, Specimen part
View SamplesWe characterized monosaccharide-dependent gene expression in the Drosophila fat body using fructose and glucose. Control and high-sugar diets were compared and RNA-seq was used to identify potential target genes. Overall design: Drosophila were reared on control (0.3 M fructose or glucose) or high sugar (1.7 M fructose or glucose) diets until the wandering third instar stage. Fat bodies were isolated and RNA was extracted to determine the effects of each sugar at different concentrations on gene expression using Illumina RNA-seq.
Similar effects of high-fructose and high-glucose feeding in a Drosophila model of obesity and diabetes.
Sex, Specimen part, Cell line, Subject
View SamplesWe compared gene expression in the Drosophila fat body on control and high-sugar diets in order to gain insight into the role of this organ during caloric overload. Differential expression analysis revealed changes in gene expression suggestive of a role for CoA metabolism in the ability to tolerate high-sugar feeding. This led us to perform biochemical and mutant studies supporting a model where CoA is limiting in the face of caloric overload. Overall design: Wild-type Drosophila were reared on control (0.15M sucrose) and high-sugar (0.7M sucrose) diets until the wandering stage. Fat bodies were isolated and RNA extracted to determine the effects of diet on gene expression using Illumina RNA-seq.
CoA protects against the deleterious effects of caloric overload in Drosophila.
Sex, Specimen part, Subject
View SamplesSystemic administration of -adrenoceptor (-AR) agonists has been found to induce skeletal muscle hypertrophy and significant metabolic changes. In the context of energy homeostasis, the importance of -AR signaling has been highlighted by the inability of 13-AR-deficient mice to regulate energy expenditure and susceptibility to diet induced obesity. However, the molecular pathways and gene expression changes that initiate and maintain these phenotypic modulations are poorly understood. Therefore, the aim of this study was to identify differential changes in gene expression in murine skeletal muscle associated with systemic acute administration of the 2-AR agonist formoterol. Skeletal muscle gene expression (from murine tibialis anterior) was profiled at both 1 and 4 hours following systemic administration of the 2-AR agonist formoterol, using 46K Illumina(R) Sentrix BeadArrays. Illumina expression profiling revealed significant expression changes in genes associated with skeletal muscle hypertrophy, myoblast differentiation, metabolism, circadian rhythm, transcription, histones, and oxidative stress.
Expression profiling of skeletal muscle following acute and chronic beta2-adrenergic stimulation: implications for hypertrophy, metabolism and circadian rhythm.
Treatment
View SamplesThe bovine chromaffin cell (BCC) is a unique modela highly homogeneous and accessible neuroendocrine cellin which to study gene regulation through first messenger-initiated signaling pathways that are specific to post-mitotic cells. BCCs were treated with tumor necrosis factor (TNF) or pituitary adenylate cyclase activating polypeptide (PACAP), two critical regulators of neural cell transcriptional programming during inflammation that act on TNFR2 and PAC1 receptors, respectively, in post-mitotic neuroendocrine cells. Transcripts which were significantly up regulated by either or both first messenger were identified from microarray analysis using two bovine oligonucleotide arrays (Affymetrix and Agilent) followed by statistical analysis with Partek Genomic suite. Microarray data were combined from the two arrays using qRT-PCR sampling validation, and the first-messenger transcriptome derived from TNF and PACAP signaling were compared. More than 90 percent of the genes up regulated either by TNF or PACAP were specific to a single first messenger. BioBase suite, DIRE and Opossum were used to identify common promoter/enhancer response elements that control the expression of TNF- or PACAP-stimulated genes. Bioinformatic analysis revealed that distinct groups of transcription factors control the expression of genes up regulated by either TNF or PACAP . Most of the genes up regulated by TNF contained response elements for members of the Rel transcription factor family, suggesting TNF-TNFR2 signaling mainly through the NF-kB signaling pathway. On the other hand, the PACAP regulated genes showed no enrichment for any single response element, containing instead response elements for combinations of transcription factors allowing activation through multiple signaling pathways, including cAMP, calcium and ERK, in neuroendocrine cells. Pharmacological strategies for mimicking neuroprotection by either PACAP or TNF in the context of CNS injury or degeneration in disease might focus on individual downstream gene activation pathways to achieve greater specificity in vivo.
Neuropeptides, growth factors, and cytokines: a cohort of informational molecules whose expression is up-regulated by the stress-associated slow transmitter PACAP in chromaffin cells.
Specimen part
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