A1-2 expression analysis of GR activation
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE30592 | GEO | 2012/02/28
SECONDARY ACCESSION(S): PRJNA144559
REPOSITORIES: GEO
Similar Datasets
Project description:A1-2 cells treated with 100 nM Dexamethasone or ethanol vehicle for 8h. The ability of steroid hormone receptors to initiate a genetic program is tightly regulated by the chromatin environment of the responsive regions. Using the glucocorticoid receptor (GR) as a model factor for transcriptional initiation, we classified chromatin structure through Formaldehyde Assisted Isolation of Regulatory Elements (FAIRE), a technique designed to identify regulatory regions and open chromatin within the genome. We looked at dynamic changes in FAIRE signals prior to and following activation of GR with its ligand, dexamethesone, specifically at regions of receptor interaction. We have found a distribution of GR responsive regions that respond to activation by varying degrees of chromatin modulation. The majority of regions that demonstrate GR interaction also demonstrate increases in FAIRE signal in response to ligand. Most of these GR responsive regions fell within a narrow window of FAIRE signal in the basal chromatin state, suggesting a preferred chromatin structure for GR recruitment. Supporting this notion, global FAIRE-seq data indicated an enrichment of signal surrounding the GR binding site prior to activation. FAIRE signal induction correlated to an increase in nuclease sensitivity and overall FAIRE signal also represented a general accessibility of the chromatin. Further investigation into the requirement of ATPase-dependent chromatin remodeling showed response element specific effects of Brg-1 knockdown. FAIRE induction was universally decreased by Brg-1 depletion, but to varying degrees in a target specific manner. Taken together, these data suggest classes of nuclear receptor response regions that react to activation through different chromatin regulatory events and identify a novel identifier of chromatin structure that classifies the majority of response elements tested. Experiment performed in triplicate. 3 biological replicates of A1-2 cells treated with dexamethasone and 3 biological replicates of A1-2 cells treated with ethanol
2012-02-28 | E-GEOD-30592 | biostudies-arrayexpress
Project description:The compaction degree of chromatin is intimately related to its functionality and active cis-regulatory elements typically exist within open chromatin regions depleted in nucleosomes (Heintzman et al. 2007; Boyle et al. 2008). These domains can be identified using Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) that allows for enrichment of nucleosome-depleted genomic regions when cross-linked chromatin is subjected to phenol-chloroform extraction (Nagy et al. 2003; Hogan et al. 2006) Here, chromatin structure was analyzed in MCF7 and LNCaP cells using Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) (Nagy et al. 2003; Hogan et al. 2006) Keywords: FAIRE-chip
2009-01-07 | GSE11579 | GEO
Project description:The compaction degree of chromatin is intimately related to its functionality and active cis-regulatory elements typically exist within open chromatin regions depleted in nucleosomes (Heintzman et al. 2007; Boyle et al. 2008). These domains can be identified using Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) that allows for enrichment of nucleosome-depleted genomic regions when cross-linked chromatin is subjected to phenol-chloroform extraction (Nagy et al. 2003; Hogan et al. 2006) Here, chromatin structure was analyzed in MCF7 and LNCaP cells using Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) (Nagy et al. 2003; Hogan et al. 2006) Keywords: FAIRE-chip MCF7 and LNCaP cells were grown in full media, cross-linked and processed as in (Nagy et al. 2003; Hogan et al. 2006). DNA obtained by FAIRE was hybridized to Human Affymetrix tiled array F. Triplicates of FAIRE and input DNA are provided (4 inputs for MCF7 cells).
2010-05-14 | E-GEOD-11579 | biostudies-arrayexpress
Project description:To quantify functional enhancers, we performed STARR-seq (Self-Transcribing Active Regulatory Region sequencing) in the U2OS-GR and the U2OS-AR cell lines (derived from U2OS ATTC:HTB-96, stably transfected with an expression construct for rat GR or human AR, respectively). U2OS-GR cells were treated with dexamethasone (1 µM) or vehicle (ethanol) for 14 hours. U2OS-AR cells were treated with R1881 (5 nM) or vehicle (DMSO) for 14 hours. To limit the number of putative enhancers, the STARR library contained genomic regions isolated by FAIRE (Formaldehyde Assisted Isolation of Regulatory Elements) from dexamethasone-treated U2OS-GR cells to include regions that gain accessibility upon GR activation. We added unique molecular identifiers (UMIs) during the reverse transcription stage to facilitate quantitative measurements of enhancer activity for each fragment. The UMI for each read is present within the sequence identifier line (directly following the y coordinate and separated by a ':') of the fastq files.
2021-03-09 | E-MTAB-9614 | biostudies-arrayexpress
Project description:These tracks display a synthesis of evidence from different assays as part of the four Open Chromatin track sets. This track displays open chromatin regions and/or transcription factor binding sites identified in multiple cell types by one or more complementary methodologies, DNaseI hypersensitivity (HS) (Duke DNaseI HS), Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) (UNC FAIRE), and chromatin immunoprecipitation (ChIP) for select regulatory factors (UTA TFBS). Each methodology was performed on the same cell type using identical growth conditions. (Note: Data for some or all ChIP experiments may not be available for all cell types). Regions that overlap between methodologies identify regulatory elements that are cross-validated indicating high confidence regions. In addition, multiple lines of evidence suggest that regions detected by a single assay (e.g., DNase-only or FAIRE-only) are also biologically relevant (Song et al., submitted). DNaseI HS data: DNaseI is an enzyme that has long been used to map general chromatin accessibility, and DNaseI "hypersensitivity" is a feature of active cis-regulatory sequences.The use of this method has led to the discovery of functional regulatory elements that include promoters, enhancers, silencers, insulators, locus control regions, and novel elements. DNaseI hypersensitivity signifies chromatin accessibility following binding of trans-acting factors in place of a canonical nucleosome. FAIRE data: FAIRE (Formaldehyde Assisted Isolation of Regulatory Elements) is a method to isolate and identify nucleosome-depleted regions of the genome. FAIRE was initially discovered in yeast and subsequently shown to identify active regulatory elements in human cells (Giresi et al., 2007). Similar to DNaseI HS, FAIRE appears to identify functional regulatory elements that include promoters, enhancers, silencers, insulators, locus control regions and novel elements. ChIP data: ChIP (Chromatin Immunoprecipitation) is a method to identify the specific location of proteins that are directly or indirectly bound to genomic DNA. By identifying the binding location of sequence-specific transcription factors, general transcription machinery components, and chromatin factors, ChIP can help in the functional annotation of the open chromatin regions identified by DNaseI HS mapping and FAIRE. Input data: As a background control experiment, we sequenced the input genomic DNA sample that was used for ChIP. Crosslinked chromatin is sheared and the crosslinks are reversed without carrying out the immunoprecipitation step. This sample is otherwise processed in a manner identical to the ChIP sample as described below. The input track is useful in revealing potential artifacts arising from the sequence alignment process such as copy number differences between the reference genome and the sequenced samples, as well as regions of poor sequence alignability. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf For each site, the maximum F-Seq Density Signal value has been calculated for each assay that was performed in that cell type. F-Seq employs Parzen kernel density estimation to create base pair scores (Boyle et al., 2008b). Significant regions, or peaks, were determined by fitting the data to a gamma distribution to calculate p-values. Contiguous regions where p-values were below a 0.05 (DNaseI HS, ChIP) or 0.1 (FAIRE) threshold were considered significant. See assay specific description pages ( Duke DNaseI HS, UNC FAIRE and UTA TFBS) for more details. A Fisher's Combined P-value for DNaseI HS and FAIRE was calculated using Fisher's combined probability test. First, a test statistic is calculated using the formula x^2 = -2*sum(ln(pi)) where pi are the p-values calculated for DNaseI HS and FAIRE. X2 follows a chi-squared distribution, thus a combined p-value can be assigned to this test statistic.
2012-09-12 | E-GEOD-40833 | biostudies-arrayexpress
Project description:Glucocorticoid hormone plays a major role in metabolism and many related diseases. The hormone-bound glucocorticoid receptor (GR) binds to a specific set of enhancers in different cell types, resulting in unique patterns of gene expression. GR-responsive enhancers have an accessible chromatin structure prior to hormone treatment (“pre-programmed”), whereas unresponsive enhancers specific to other cell types are inaccessible and inactive. Here we have addressed the role of chromatin structure in cell-specific GR-enhancer programming by precise mapping of nucleosome positions in mouse adenocarcinoma cells. We show that, before hormone treatment, some pre-programmed GR-enhancers are nucleosome-depleted, associated with the Brg1 chromatin remodeler and flanked by nucleosomes exchanging histones H2A.Z and H2A. However, most pre-programmed GR-enhancers are assembled into a nucleosome that exchanges H2A.Z and H2A, with little or no Brg1. After hormone treatment, nucleosomes at both types of pre-programmed GR-enhancer shift apart, coinciding with increased levels of Brg1, and continue to exchange H2A.Z and H2A. Hormone removal rapidly reverses these nucleosome shifts. In contrast, inactive GR-enhancers are nucleosomal, lack Brg1, do not exchange H2A.Z or H2A and do not respond to hormone. Thus, pre-programmed GR-enhancers are marked by a dynamic, mutable chromatin structure characterized by high levels of H2A.Z exchange. We propose that nucleosome-depleted GR-enhancers result from the binding of other transcription factors together with Brg1 to assist loading of GR after hormone treatment. At nucleosomal enhancers, GR binding may be directly facilitated by increased transient exposure of enhancer DNA associated with H2A.Z exchange.
2017-11-06 | GSE92505 | GEO
Project description:This data was generated by ENCODE. If you have questions about the data, contact the submitting laboratory directly (Terry Furey mailto:tsfurey@duke.edu). If you have questions about the Genome Browser track associated with this data, contact ENCODE (mailto:genome@soe.ucsc.edu). These tracks display a synthesis of evidence from different assays as part of the four Open Chromatin track sets. This track displays open chromatin regions and/or transcription factor binding sites identified in multiple cell types by one or more complementary methodologies, DNaseI hypersensitivity (HS) (Duke DNaseI HS), Formaldehyde-Assisted Isolation of Regulatory Elements (FAIRE) (UNC FAIRE), and chromatin immunoprecipitation (ChIP) for select regulatory factors (UTA TFBS). Each methodology was performed on the same cell type using identical growth conditions. (Note: Data for some or all ChIP experiments may not be available for all cell types). Regions that overlap between methodologies identify regulatory elements that are cross-validated indicating high confidence regions. In addition, multiple lines of evidence suggest that regions detected by a single assay (e.g., DNase-only or FAIRE-only) are also biologically relevant (Song et al., submitted). DNaseI HS data: DNaseI is an enzyme that has long been used to map general chromatin accessibility, and DNaseI "hypersensitivity" is a feature of active cis-regulatory sequences.The use of this method has led to the discovery of functional regulatory elements that include promoters, enhancers, silencers, insulators, locus control regions, and novel elements. DNaseI hypersensitivity signifies chromatin accessibility following binding of trans-acting factors in place of a canonical nucleosome. FAIRE data: FAIRE (Formaldehyde Assisted Isolation of Regulatory Elements) is a method to isolate and identify nucleosome-depleted regions of the genome. FAIRE was initially discovered in yeast and subsequently shown to identify active regulatory elements in human cells (Giresi et al., 2007). Similar to DNaseI HS, FAIRE appears to identify functional regulatory elements that include promoters, enhancers, silencers, insulators, locus control regions and novel elements. ChIP data: ChIP (Chromatin Immunoprecipitation) is a method to identify the specific location of proteins that are directly or indirectly bound to genomic DNA. By identifying the binding location of sequence-specific transcription factors, general transcription machinery components, and chromatin factors, ChIP can help in the functional annotation of the open chromatin regions identified by DNaseI HS mapping and FAIRE. Input data: As a background control experiment, we sequenced the input genomic DNA sample that was used for ChIP. Crosslinked chromatin is sheared and the crosslinks are reversed without carrying out the immunoprecipitation step. This sample is otherwise processed in a manner identical to the ChIP sample as described below. The input track is useful in revealing potential artifacts arising from the sequence alignment process such as copy number differences between the reference genome and the sequenced samples, as well as regions of poor sequence alignability. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf For each site, the maximum F-Seq Density Signal value has been calculated for each assay that was performed in that cell type. F-Seq employs Parzen kernel density estimation to create base pair scores (Boyle et al., 2008b). Significant regions, or peaks, were determined by fitting the data to a gamma distribution to calculate p-values. Contiguous regions where p-values were below a 0.05 (DNaseI HS, ChIP) or 0.1 (FAIRE) threshold were considered significant. See assay specific description pages ( Duke DNaseI HS, UNC FAIRE and UTA TFBS) for more details. A Fisher's Combined P-value for DNaseI HS and FAIRE was calculated using Fisher's combined probability test. First, a test statistic is calculated using the formula x^2 = -2*sum(ln(pi)) where pi are the p-values calculated for DNaseI HS and FAIRE. X2 follows a chi-squared distribution, thus a combined p-value can be assigned to this test statistic.
2011-10-25 | E-GEOD-33213 | biostudies-arrayexpress
Project description:This study introduces the identification of genome-wide cancer-specific chromatin signatures from archival tissues using nanodroplet-assisted FAIRE-seq. Our enhanced cavitation method, a nanodroplet reagent consisting of a lipid shell with a liquid perfluorocarbon core, facilitated the extraction of intact chromatin from FFPE xenograft tissues across 3 cancer types, encompassing 10 cell lines. Chromatin states that influence gene expression and other nuclear processes can be altered in disease. Studying these patterns in tissues has been limited since existing chromatin accessibility assays are ineffective for archival formalin-fixed, paraffin embedded (FFPE) tissues. Inclusion of nanodroplets during the extraction of chromatin from FFPE tissues enhances the recovery of intact accessible and nucleosome-bound chromatin. We demonstrate that the addition of nanodroplets to the chromatin accessibility assay FAIRE (formaldehyde-assisted isolation of regulatory elements), does not affect the accessible chromatin signal. Applying the technique to FFPE human tumor xenografts, we identified tumor-relevant regions of accessible chromatin shared with those identified in primary tumors. Further, we deconvoluted non-tumor signal to identify cellular components of the tumor microenvironment. Incorporation of this method of enhanced cavitation into FAIRE offers the potential for extending chromatin accessibility to clinical diagnosis and personalized medicine, while also enabling the exploration of gene regulatory mechanisms is archival samples.
2021-10-26 | GSE162443 | GEO
Project description:Purpose: To identify nucleosome-depleted regions in response to drought in the kidney bean, a genome-wide chromatin profiling strategy was implemented. A better understanding of these OCRs (Open chromatin regions) will be useful in exploring potential genomic regions for crop improvement. Results: Using a comprehensive FAIRE-Seq approach, nucleosome-free chromatin regions were explored in kidney bean (Phaseolus vulgaris. L) in response to both drought and rewatering stress. In all samples, FAIRE peaks (>50%) were enriched in the promoter regions. The drought samples showed peaks very distinct from control and rewatered samples, which showed peaks predominantly at the transcription start site (TSS). Drought and heat-responsive genes and transcription factors were identified within the flanking region of differential peaks. When drought was compared to control, it showed upregulated differential peaks primarily in the promoter and distal intergenic regions. Conclusion: By analyzing FAIRE we are able to identify distinct genomic regions corresponding to droughts and controls. Upstream regions of genes play a significant role in drought stress response. Our data suggest that promoter regions of >2 kb, downstream regions of <= 300, and distant regulatory regions are predominant during the upregulation of drought stress. It would also be helpful to note that genomic regions vary in response to drought, and distal intergenic regions may also be involved in drought responses. Understanding plant genomes and epigenomics could help us develop varieties that can withstand extreme weather conditions.
2023-11-08 | GSE187025 | GEO
Project description:Genomic enhancers regulate spatio-temporal gene expression by recruiting specific combinations of transcription factors (TFs). When TFs are bound to active regulatory regions, they displace canonical nucleosomes, making these regions biochemically detectable as nucleosome-depleted regions or accessible/open chromatin. Here we ask whether open chromatin profiling can be used to identify the entire repertoire of active promoters and enhancers underlying tissue-specific gene expression during normal development and oncogenesis in vivo. To this end, we first compare two different approaches to detect open chromatin in vivo using the Drosophila eye primordium as a model system: FAIRE-seq, based on physical separation of open versus closed chromatin; and ATAC-seq, based on preferential integration of a transposon into open chromatin. We find that both methods reproducibly capture the tissue-specific chromatin activity of regulatory regions, including promoters, enhancers, and insulators. Using both techniques, we screened for regulatory regions that become ectopically active during Ras-dependent oncogenesis, and identified 3778 regions that become (over-)activated during tumor development. Next, we applied motif discovery to search for candidate transcription factors that could bind these regions and identified AP-1 and Stat92E as key regulators. We validated the importance of Stat92E in the development of the tumors by introducing a loss of function Stat92E mutant, which was sufficient to rescue the tumor phenotype. Additionally we tested if the predicted Stat92E responsive regulatory regions are genuine, using ectopic induction of JAK/STAT signaling in developing eye discs, and observed that similar chromatin changes indeed occurred. Finally, we determine that these are functionally significant regulatory changes, as nearby target genes are up- or down-regulated. In conclusion, we show that FAIRE-seq and ATAC-seq based open chromatin profiling, combined with motif discovery, is a straightforward approach to identify functional genomic regulatory regions, master regulators, and gene regulatory networks controlling complex in vivo processes. FAIRE-Seq in Drosophila wild type eye-antennal imaginal discs (2 wt strains); ATAC-Seq in Drosophila wild type eye-antennal imaginal discs (3 wt strains) ; FAIRE-Seq in Drosophila Ras/Scrib induced eye disc tumors (1 early and 1 late); ATAC-Seq in Drosophila Ras/Scrib induced eye disc tumors (1 early and 1 late); ATAC-Seq in Drosophila eye discs with Unpaired over-expression (2 biological replicates); CTCF ChIP-seq in Drosophila eye discs; ChIP-seq input in Drosophila eye discs
2015-02-13 | E-GEOD-59078 | biostudies-arrayexpress