Similar Datasets
Project description:The Glucocorticoid Receptor (GR) potently represses macrophage-elicited inflammation, however, the underlying mechanisms remain obscure. Our genome-wide analysis reveals that pro-inflammatory paused genes, activated via global negative elongation factor (NELF) dissociation and RNA Polymerase (Pol)2 release from early elongation arrest, and non-paused genes, induced by de novo Pol2 recruitment, are equally susceptible to acute glucocorticoid repression. Moreover, in both cases the dominant mechanism involves rapid GR tethering to p65 at NF-kB binding sites. Yet, specifically at paused genes, GR activation triggers widespread promoter accumulation of NELF, with myeloid cell-specific NELF deletion conferring glucocorticoid resistance. Conversely, at non-paused genes, GR attenuates the recruitment of p300 and histone acetylation, leading to a failure to assemble BRD4 and Mediator at promoters and enhancers, ultimately blocking Pol2 initiation. Thus, GR displays no preference for a specific pro-inflammatory gene class, however, it effects repression by targeting distinct temporal events and components of transcriptional machinery
2018-02-28 | GSE109131 | GEO
Project description:The Glucocorticoid Receptor (GR) potently represses macrophage-elicited inflammation, however, the underlying mechanisms remain obscure. Our genome-wide analysis reveals that pro-inflammatory paused genes, activated via global negative elongation factor (NELF) dissociation and RNA Polymerase (Pol)2 release from early elongation arrest, and non-paused genes, induced by de novo Pol2 recruitment, are equally susceptible to acute glucocorticoid repression. Moreover, in both cases the dominant mechanism involves rapid GR tethering to p65 at NF-kB binding sites. Yet, specifically at paused genes, GR activation triggers widespread promoter accumulation of NELF, with myeloid cell-specific NELF deletion conferring glucocorticoid resistance. Conversely, at non-paused genes, GR attenuates the recruitment of p300 and histone acetylation, leading to a failure to assemble BRD4 and Mediator at promoters and enhancers, ultimately blocking Pol2 initiation. Thus, GR displays no preference for a specific pro-inflammatory gene class, however, it effects repression by targeting distinct temporal events and components of transcriptional machinery
2018-02-28 | GSE110243 | GEO
Project description:The glucocorticoid receptor (GR) potently represses macrophage-elicited inflammation, however, the underlying mechanisms remain obscure. Our genome-wide analysis in mouse macrophages reveals that pro-inflammatory paused genes, activated via global negative elongation factor (NELF) dissociation and RNA Polymerase (Pol)2 release from early elongation arrest, and non-paused genes, induced by de novo Pol2 recruitment, are equally susceptible to acute glucocorticoid repression. Moreover, in both cases the dominant mechanism involves rapid GR tethering to p65 at NF-kB-binding sites. Yet, specifically at paused genes, GR activation triggers widespread promoter accumulation of NELF, with myeloid cell-specific NELF deletion conferring glucocorticoid resistance. Conversely, at non-paused genes, GR attenuates the recruitment of p300 and histone acetylation, leading to a failure to assemble BRD4 and Mediator at promoters and enhancers, ultimately blocking Pol2 initiation. Thus, GR displays no preference for a specific pro-inflammatory gene class; however, it effects repression by targeting distinct temporal events and components of transcriptional machinery.
| S-EPMC5821458 | biostudies-literature
Project description:Gene-specific mechanisms dictate glucocorticoid receptor-mediated repression of inflammatory response genes in macrophages
| PRJNA433364 | ENA
Project description:Gene-specific mechanisms dictate glucocorticoid receptor-mediated repression of inflammatory response genes in macrophages [ChIP-seq]
| PRJNA429743 | ENA
Project description:Gene-specific mechanisms dictate glucocorticoid receptor-mediated repression of inflammatory response genes in macrophages [RNA-seq]
| PRJNA433244 | ENA
Project description:Nuclear receptors such as the glucocorticoid receptor (GR) are ligand-dependent transcription factors that mediate transcription of target genes by recruiting factors that modulate chromatin structure. In this study, curcumin, a compound known to inhibit GR-mediated transcription, was used to examine the different mechanisms by which GR regulates transcription. The mechanisms of transcription regulation of metallothioneine-2A (MT2A) and solute carrier family 19 member 2 (SLC19A2), two GR target genes where the hormone-dependent gene activation is inhibited or unaffected by curcumin treatment, respectively, were analyzed by chromatin immunoprecipitation and RT-PCR experiments. The data suggest that the loss of hormone-dependent MT2A gene expression is due to the inhibition of continued transcription activity after initial assembly of the transcription machinery. In contrast, the hormone-dependent SLC19A2 gene expression is maintained because the continued transcription output after assembly of transcription machinery is unaffected by curcumin. These results suggest that the two GR target genes use alternate mechanisms to regulate expression levels at the level of continued transcription output after transcription machinery assembly.
| S-EPMC3039389 | biostudies-literature
Project description:BACKGROUND: BRCA mutations are the main known hereditary factor for ovarian cancer. Notably, emerging evidence indicates that the glucocorticoid receptor (GR) has drawn considerable interest in ovarian cancer development. However, dynamic cross-talk between BRCA1 and GR signaling pathways are poorly understood. METHODS: The regulatory effects of BRCA on GR were assessed in 146 serous ovarian cancer patients (28 pairs of BRCA1-mutated or not, 23 pairs of BRCA2-mutated or not, and 22 pairs with hypermethylated BRCA1 promoter or not). BRCA1 promoter methylation was analyzed by bisulfite sequencing using primers flanking the core promoter region. Expression levels of BRCA1 and GR were assessed by immunohistochemistry and real-time PCR. Regression analysis was used to examine the possible relationship between BRCA1 and GR expression levels. The knockdown and overexpression of BRCA1 were achieved using a lentiviral vector in 293 T cells, SKOV3 ovarian cancer cells, and primary non-mutated and BRCA1-mutated ovarian cancer cells. RESULTS: GR expression levels were unchanged in non-BRCA1-mutated, non-BRCA2-mutated and BRCA2-mutated ovarian cancer compared to their normal tissues; BRCA1 repression (BRCA1 mutation or BRCA1 promoter hypermethylation) ovarian cancer showed decreased GR levels compared to normal tissue; there was a positive correlation between BRCA1 and GR expression in human ovarian cancer specimens; BRCA1 knockdown was effective at inhibiting GR expression, and overexpression of BRCA1 induces an increase in GR levels in ovarian cancer cells. CONCLUSIONS: These results suggest that GR may be a potential target for BRCA1 in ovarian cancer progression.
| S-EPMC4004164 | biostudies-literature
Project description:The glucocorticoid receptor (GR) affects the transcription of genes involved in diverse processes, including energy metabolism and the immune response, through DNA-binding dependent and independent mechanisms. The DNA-binding dependent mechanism occurs by direct binding of GR to glucocorticoid response elements (GREs) at regulatory regions of target genes. The DNA-binding independent mechanism involves binding of GR to transcription factors and coactivators that, in turn, contact DNA. A small molecule that competes with GR for binding to GREs could be expected to affect the DNA-dependent pathway selectively by interfering with the protein-DNA interface. We show that a DNA-binding polyamide that targets the consensus GRE sequence binds the glucocorticoid-induced zipper (GILZ) GRE, inhibits expression of GILZ and several other known GR target genes, and reduces GR occupancy at the GILZ promoter. Genome-wide expression analysis of the effects of this polyamide on a set of glucocorticoid-induced and -repressed genes could help to elucidate the mechanism of GR regulation for these genes.
| S-EPMC2744631 | biostudies-literature
Project description:Despite the widespread use of glucocorticoids (GCs), their anti-inflammatory effects are not understood mechanistically. Numerous investigations have examined the effects of glucocorticoid receptor (GR) activation prior to inflammatory challenges. However, clinical situations are emulated by a GC intervention initiated in the midst of rampant inflammatory responses. To characterize the effects of a late GC treatment, we profiled macrophage transcriptional and chromatinscapes with Dexamethasone (Dex) treatment before or after stimulation by lipopolysaccharide (LPS). The late activation of GR had a similar gene-expression profile as from GR pre-activation, while ameliorating the disruption of metabolic genes. Chromatin occupancy of GR was not predictive of Dex-regulated gene expression, contradicting the "trans-repression by tethering" model. Rather, GR activation resulted in genome-wide blockade of NF-κB interaction with chromatin and directly induced inhibitors of NF-κB and AP-1. Our investigation using GC treatments with clinically relevant timing highlights mechanisms underlying GR actions for modulating the "inflamed epigenome."
| S-EPMC5572836 | biostudies-literature