Project description:Thymic central tolerance is essential to preventing autoimmunity. In medullary thymic epithelial cells (mTECs), the Autoimmune regulator (Aire) gene plays an essential role in this process by driving the expression of a diverse set of tissue-specific antigens (TSAs), which are presented and help tolerize self-reactive thymocytes. Interestingly, Aire has a highly tissue-restricted pattern of expression, with only mTECs and peripheral extrathymic Aire-expressing cells (eTACs) known to express detectable levels in adults. Despite this high level of tissue specificity, the cis-regulatory elements that control Aire expression have remained obscure. We used sequence conservation analysis and ChIP-seq against the enhancer-associated histone mark H3K27ac to identify a candidate Aire cis-regulatory element. There is enrichment of H3K27ac near this element, ACNS1, in mTECs and the element also has characteristics of being NF-κB-responsive. Finally, we find that this element is essential for Aire expression in vivo and necessary to prevent spontaneous autoimmunity, reflecting the importance of this regulatory DNA element in promoting immune tolerance. Two experimental groups (GFP neg mTECs and GFP pos mTECs), each with three samples, and one control sample (D10 Th2 cells).
Project description:Thymic central tolerance is essential to preventing autoimmunity. In medullary thymic epithelial cells (mTECs), the Autoimmune regulator (Aire) gene plays an essential role in this process by driving the expression of a diverse set of tissue-specific antigens (TSAs), which are presented and help tolerize self-reactive thymocytes. Interestingly, Aire has a highly tissue-restricted pattern of expression, with only mTECs and peripheral extrathymic Aire-expressing cells (eTACs) known to express detectable levels in adults. Despite this high level of tissue specificity, the cis-regulatory elements that control Aire expression have remained obscure. We used sequence conservation analysis and ChIP-seq against the enhancer-associated histone mark H3K27ac to identify a candidate Aire cis-regulatory element. There is enrichment of H3K27ac near this element, ACNS1, in mTECs and the element also has characteristics of being NF-κB-responsive. Finally, we find that this element is essential for Aire expression in vivo and necessary to prevent spontaneous autoimmunity, reflecting the importance of this regulatory DNA element in promoting immune tolerance.
Project description:We describe, MARGE, Model-based Analysis of the Regulation of Gene Expression, a robust methodology that leverages a large library of genome-wide H3K27ac ChIP-seq profiles to predict key regulated genes and cis-regulatory regions in human or mouse. MARGE adopts a gene centric approach to define a regulatory potential that summarizes the aggregate activity of multiple cis-regulatory elements on each gene. This model is effective in describing cis-regulatory activity and, unlike the super-enhancer based approach, is highly predictive of gene expression changes in response to BET-bromodomain inhibitors. We show that linear combinations of H3K27ac defined regulatory potentials, selected from an extensive database of published H3K27ac profiles, can accurately model diverse gene sets derived from differential gene expression experiments. In addition, we demonstrate a novel semi-supervised learning approach for identifying transcription factor binding sites associated with the set of transcription factors that regulate the gene set. MARGE leverages published H3K27ac ChIP-seq data to enhance the interpretation of newly generated H3K27ac ChIP-seq profiles. MARGE can also be used to analyze gene expression studies, without the production of matched H3K27ac ChIP-seq data. Identifying genomic profiles of histone modification H3K27ac in LNCaP-abl cell line after siRNA knock down of a series of gene factors.
Project description:We describe, MARGE, Model-based Analysis of the Regulation of Gene Expression, a robust methodology that leverages a large library of genome-wide H3K27ac ChIP-seq profiles to predict key regulated genes and cis-regulatory regions in human or mouse. MARGE adopts a gene centric approach to define a regulatory potential that summarizes the aggregate activity of multiple cis-regulatory elements on each gene. This model is effective in describing cis-regulatory activity and, unlike the super-enhancer based approach, is highly predictive of gene expression changes in response to BET-bromodomain inhibitors. We show that linear combinations of H3K27ac defined regulatory potentials, selected from an extensive database of published H3K27ac profiles, can accurately model diverse gene sets derived from differential gene expression experiments. In addition, we demonstrate a novel semi-supervised learning approach for identifying transcription factor binding sites associated with the set of transcription factors that regulate the gene set. MARGE leverages published H3K27ac ChIP-seq data to enhance the interpretation of newly generated H3K27ac ChIP-seq profiles. MARGE can also be used to analyze gene expression studies, without the production of matched H3K27ac ChIP-seq data. Transcriptome profiling in LNCaP-abl cell line after siRNA knock down of a series of gene factors.
Project description:The HASTER promoter region is a cis-regulatory element that stabilizes the transcription of HNF1A, preventing silencing or overexpression. We have generated a mouse model where the promoter of Haster has been specifically deleted in liver (Haster loxP/loxP; AlbCre). In liver the prevailing consequence is upregulation of HNF1A. We performed HNF1A, H3K4me3 and H3K27ac ChIP-seq to assess the impact of HNF1A upregulation on the chromatin landscape of Haster KO liver.
Project description:We describe, MARGE, Model-based Analysis of the Regulation of Gene Expression, a robust methodology that leverages a large library of genome-wide H3K27ac ChIP-seq profiles to predict key regulated genes and cis-regulatory regions in human or mouse. MARGE adopts a gene centric approach to define a regulatory potential that summarizes the aggregate activity of multiple cis-regulatory elements on each gene. This model is effective in describing cis-regulatory activity and, unlike the super-enhancer based approach, is highly predictive of gene expression changes in response to BET-bromodomain inhibitors. We show that linear combinations of H3K27ac defined regulatory potentials, selected from an extensive database of published H3K27ac profiles, can accurately model diverse gene sets derived from differential gene expression experiments. In addition, we demonstrate a novel semi-supervised learning approach for identifying transcription factor binding sites associated with the set of transcription factors that regulate the gene set. MARGE leverages published H3K27ac ChIP-seq data to enhance the interpretation of newly generated H3K27ac ChIP-seq profiles. MARGE can also be used to analyze gene expression studies, without the production of matched H3K27ac ChIP-seq data.
Project description:We describe, MARGE, Model-based Analysis of the Regulation of Gene Expression, a robust methodology that leverages a large library of genome-wide H3K27ac ChIP-seq profiles to predict key regulated genes and cis-regulatory regions in human or mouse. MARGE adopts a gene centric approach to define a regulatory potential that summarizes the aggregate activity of multiple cis-regulatory elements on each gene. This model is effective in describing cis-regulatory activity and, unlike the super-enhancer based approach, is highly predictive of gene expression changes in response to BET-bromodomain inhibitors. We show that linear combinations of H3K27ac defined regulatory potentials, selected from an extensive database of published H3K27ac profiles, can accurately model diverse gene sets derived from differential gene expression experiments. In addition, we demonstrate a novel semi-supervised learning approach for identifying transcription factor binding sites associated with the set of transcription factors that regulate the gene set. MARGE leverages published H3K27ac ChIP-seq data to enhance the interpretation of newly generated H3K27ac ChIP-seq profiles. MARGE can also be used to analyze gene expression studies, without the production of matched H3K27ac ChIP-seq data.
Project description:We performed ChIP-Seq analysis of SOX10, histone H3 lysine 27 acetylation (H3K27ac) and H3K27 trimethylation (H3K27me3) in melanocytes to profile the genomic binding sites of SOX10 and the chromatin landscape. In parallel, we generated Sox10 haploinsufficient cell lines using gene knockout approaches and conducted microarray gene expression analysis to identify functional gene targets of SOX10 transcriptional regulation in melanocytes. We demonstrate that SOX10 predominantly engages “open” chromatin, binds to melanocyte enhancer elements and plays a central role in transcriptional activation and repression of functionally distinct classes of genes. Furthermore, we identified cis-regulatory sequence motifs of putative co-regulatory transcription factors that define SOX10-activated and SOX10-repressed target genes. Our results uncover novel mechanisms and roles of SOX10 in global transcriptional regulation of diverse regulatory pathways in the melanocyte lineage. ChIP-seq profiling of SOX10, H3K27ac, and H3K27me3 in the mouse melanocyte cell line melan-Ink4a-Arf-1 (melan-a).
Project description:We identified p63 target genes and binding sites responsible for ectodermal defects by genome-wide profiling of p63 binding using ChIP-seq and expression analysis in human primary keratinocytes from patients with p63 mutations. As proof of principle, we identified a novel de novo microdeletion causing limb defects (SHFM1) that includes a p63 binding site functioning as a cis-regulatory element to control expression of the distally located DLX5/DLX6 genes essential for limb development. Our data demonstrate that target genes and regulatory elements detected in this study can serve as powerful tools to identify causative mutations of unresolved ectodermal disorders. ChIP-seq profiles of p63 in primary human keratinocytes established from two different normal individuals.