Mus musculus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA308546 | ENA |
REPOSITORIES: ENA
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Project description:Histone acetylation and the acetyl-lysine reader Brd4 have recently been implicated in embryonic stem cell (ESC) proliferation and self-renewal. We found that na•ve pluripotent ESCs exhibit increased incorporation of glucose-derived carbons onto acetylated histones and elevations in H3K9ac and Brd4 recruitment at pluripotency gene promoters. Surprisingly, both H3K9 acetyltransferases, GCN5 and PCAF, and Brd4 recruitment were dispensable for proliferation, self-renewal and pluripotency of na•ve ESCs. Na•ve ESCs maintain gene expression by stabilizing Mediator at core pluripotency genes in a Brd4-independent manner. Brd4-independent proliferation could also be achieved in metastable ESCs by overexpression of pluripotency transcription factors. Under all conditions, self-renewal required the DNA methylcytosine oxidases Tet1 and Tet2. These data reveal that there is minimal dependence on Brd4 for self-renewal of na•ve ESCs. Instead, the relative levels of DNA methylation and transcription factor abundance determine the requirement for bromodomain recognition of histone acetylation to the maintenance of stem cell identity.
2018-04-09 | GSE88769 | GEO
Project description:Histone acetylation and the acetyl-lysine reader Brd4 have recently been implicated in embryonic stem cell (ESC) proliferation and self-renewal. We found that naïve pluripotent ESCs exhibit increased incorporation of glucose-derived carbons onto acetylated histones and elevations in H3K9ac and Brd4 recruitment at pluripotency gene promoters. Surprisingly, both H3K9 acetyltransferases, GCN5 and PCAF, and Brd4 recruitment were dispensable for proliferation, self-renewal and pluripotency of naïve ESCs. Naïve ESCs maintain gene expression by stabilizing Mediator at core pluripotency genes in a Brd4-independent manner. Brd4-independent proliferation could also be achieved in metastable ESCs by overexpression of pluripotency transcription factors. Under all conditions, self-renewal required the DNA methylcytosine oxidases Tet1 and Tet2. These data reveal that there is minimal dependence on Brd4 for self-renewal of naïve ESCs. Instead, the relative levels of DNA methylation and transcription factor abundance determine the requirement for bromodomain recognition of histone acetylation to the maintenance of stem cell identity.
2018-04-10 | GSE88760 | GEO
Project description:Schizophrenia (SZ) is a psychiatric disorder with complex genetic risk dictated by interactions between hundreds of risk variants. Epigenetic factors, such as histone posttranslational modifications (PTMs), have been shown to play critical roles in many neurodevelopmental processes, and when perturbed may also contribute to the precipitation of disease. Here, we apply an unbiased proteomics approach to evaluate combinatorial histone PTMs in human induced pluripotent stem cell (hiPSC)-derived forebrain neurons from individuals with SZ. We observe hyper-acetylation of H2A.Z and H4 in neurons derived from SZ cases, results that were confirmed in postmortem human brain. We demonstrate that the bromodomain and extraterminal (BET) protein, BRD4, is a bona fide ‘reader’ of H2A.Z acetylation, and further provide evidence that BET family protein inhibition ameliorates transcriptional abnormalities in patient-derived neurons. Thus, treatments aimed at alleviating BET protein interactions with hyperacetylated histones may aid in the prevention or treatment of SZ.
2022-05-06 | PXD031767 | Pride
Project description:The relative contributions of sequence-specific transcription factors and DNA/histone modifications to stem cell maintenance remains controversial. For example, the acetyllysine reader Brd4 has been implicated in stem cell maintenance, but how absolute the role of Brd4 is in maintaining pluripotency remains unclear. Here we show that Brd4 is dispensable for the proliferation, self-renewal and pluripotency of embryonic stem cells. In naive, ground state pluripotent stem cells, Mediator recruitment and transcription factor binding to stem cell-specific genes are maintained in the absence of Brd4 function or expression. Even in metastable embryonic stem cells poised for differentiation, Brd4 independence can be maintained by overexpression of pluripotency transcription factors so long as the DNA methylcytosine oxidases, Tet1 and Tet2, are present to facilitate chromatin accessibility. These data reveal that Brd4 is not essential for self-renewal of embryonic stem cells. Rather, Brd4 contributes to stem cell maintenance only under conditions where the expression of pluripotency transcription factors and/or DNA demethylation machinery is compromised.
2018-04-09 | GSE95641 | GEO
Project description:Schizophrenia (SZ) is a psychiatric disorder with complex genetic risk dictated by interactions between hundreds of risk variants. Epigenetic factors, such as histone posttranslational modifications (PTMs), have been shown to play critical roles in many neurodevelopmental processes, and when perturbed may also contribute to the precipitation of disease. Here, we applied an unbiased proteomics approach to evaluate combinatorial histone PTMs in human induced pluripotent stem cell (hiPSC)-derived forebrain neurons from individuals with SZ. We observed hyper-acetylation of H2A.Z and H4 in neurons derived from SZ cases, results that were confirmed in postmortem human brain. We demonstrated that the bromodomain containing protein, BRD4, is a bona fide ‘reader’ of H2A.Z acetylation, and further provide evidence that BRD4 inhibition ameliorates transcriptional abnormalities in patient-derived neurons and improves sensorimotor gating behavior in mice. Thus, treatments aimed at alleviating BRD4 interactions with hyperacetylated histones may aid in the prevention or treatment of SZ.
2022-01-12 | GSE144639 | GEO
Project description:Histone acetylation is associated with active transcription and serves as a binding site for reader proteins that function in transcriptional initiation and elongation. Histone acetylation levels are regulated through the actions of histone acetyltransferases (HATs) and histone deacetylases (HDACs) that antagonistically control the overall balance of this posttranslational modification. HDAC inhibitors (HDACi) are potent agents that disrupt this balance and are used clinically to treat a range of human diseases including cancer. Despite their clinical applications, little is known about their chromatin effects. By applying quantitative genomic and proteomic approaches, we demonstrate that HDACi robustly increase a low abundance histone acetylation state (H4 K5ac/K8ac/12ac/K16ac), which serves as a preferred binding substrate for a variety of human bromodomain-containing proteins, including BRD4. This H4 polyacetylation signature observed after HDACi treatment accumulates in the transcribed regions of genes and correlates with the targeting of BRD4 to genes with increased gene expression. Collectively, these results suggest that HDAC inhibition functions, at least in part, through expansion of a rare chromatin acetylation state, which then retargets lysine-acetyl reader proteins associated with changes in gene expression.
2020-10-20 | GSE159620 | GEO
Project description:Mouse embryonic stem cells (ESCs) cultured with inhibitors of MEK and GSK3 (2iL) more closely resemble the pre-implantation embryo inner cell mass than cultures in serum/LIF (SL). Unveiling the differences between both systems is important for understanding development and could also assist in isolating an ESC equivalent for other mammalian species. In SL, pluripotency and cell cycle gene transcription is a multistep process requiring release of promoter-proximal paused RNA polymerase II (Pol2) by the histone acetylation reader BRD4 and the Pol2 kinase CDK9. Here, we show that recruitment of co-regulators including Mediator and Cohesin by β-catenin changes the mode of transcriptional regulation at BRD4/CDK9-bound loci in 2iL. This switch renders pluripotency genes more reliant on transcriptional initiation and less on Pol2 pause release for effective gene body elongation. Conversely, cell cycle genes are not bound by β-catenin and are still dependent on Pol2 pause release. Thus, pluripotency is more resistant to BRD4/CDK9 suppression in 2iL while self-renewal remains highly sensitive. Our findings help to explain how pluripotency is shielded in the ground state and provide insight into transcriptional adaptation upon network perturbation in other contexts.
2020-07-01 | GSE123691 | GEO
Project description:Mouse embryonic stem cells (ESCs) cultured with inhibitors of MEK and GSK3 (2iL) more closely resemble the pre-implantation embryo inner cell mass than cultures in serum/LIF (SL). Unveiling the differences between both systems is important for understanding development and could also assist in isolating an ESC equivalent for other mammalian species. In SL, pluripotency and cell cycle gene transcription is a multistep process requiring release of promoter-proximal paused RNA polymerase II (Pol2) by the histone acetylation reader BRD4 and the Pol2 kinase CDK9. Here, we show that recruitment of co-regulators including Mediator and Cohesin by β-catenin changes the mode of transcriptional regulation at BRD4/CDK9-bound loci in 2iL. This switch renders pluripotency genes more reliant on transcriptional initiation and less on Pol2 pause release for effective gene body elongation. Conversely, cell cycle genes are not bound by β-catenin and are still dependent on Pol2 pause release. Thus, pluripotency is more resistant to BRD4/CDK9 suppression in 2iL while self-renewal remains highly sensitive. Our findings help to explain how pluripotency is shielded in the ground state and provide insight into transcriptional adaptation upon network perturbation in other contexts.
2020-07-01 | GSE123690 | GEO
Project description:The ground state of pluripotency is defined as a basal proliferative state free of epigenetic restriction, represented by mouse embryonic stem cells (ESCs) cultured with two kinase inhibitors (so-called “2i”). Through comparison with serum-grown ESCs, we identify epigenetic features characterizing 2i ESCs by proteome profiling of chromatin including post-translational histone modifications. The most prominent difference is H3K27me3 and its enzymatic writer complex PRC2 that are highly abundant on eu- and heterochromatin in 2i ESCs, with H3K27me3 redistributing outside canonical PRC2 targets in a CpG-dependent fashion. Using PRC2-deficient 2i ESCs, we identify epigenetic crosstalk with H3K27me3, including significant increases in H4 acetylation and DNA methylation. This suggests that the unique H3K27me3 configuration protects 2i ESCs from preparation to lineage priming. Interestingly, removal of DNA methylation in PRC2-deficient 2i ESCs lacking H3K27me3 using 5-azacytidine hardly affected ESC viability and transcriptome, showing that ESCs are independent of both major repressive epigenetic marks.
2018-11-21 | PXD007154 | Pride
Project description:Transcriptional elongation by RNA polymerase II (Pol II) is regulated by positive transcription elongation factor b (P-TEFb) in association with Bromodomain-containing protein 4 (BRD4). We used genome-wide chromatin immunoprecipitation sequencing in primary human CD4+ T cells to reveal that BRD4 co-localizes with Ser2-phosphorylated Pol II (Pol II Ser2) at both enhancers and promoters of active genes. Disruption of bromodomain:histone acetylation interactions by JQ1, a small-molecule bromodomain inhibitor, resulted in decreased BRD4 binding, reduced Pol II Ser2, and reduced expression of lineage-specific genes in primary human CD4+ T cells. A large number of JQ1-disrupted BRD4 binding regions exhibited di-acetylated H4 (lysine-5 and -8) and H3K27 acetylation (H3K27ac), which correlated with the presence of histone acetyltransferases and deacetylases. Genes associated with BRD4/H3K27ac co-occupancy exhibited significantly higher activity than those associated with H3K27ac or BRD4 binding alone. Comparison of BRD4 binding in T cells and in human embryonic stem cells revealed that enhancer BRD4 binding sites were predominantly lineage-specific. Our findings suggest that BRD4-driven Pol II phosphorylation at serine 2 plays an important role in regulating lineage-specific gene transcription in human CD4+ T cells. Examination of BRD4, total Pol II, serine 2 phosphorylated Pol II and serine 5 phosphorylated Pol II binding in CD4+ T cells (with and without JQ1 treatment) and BRD4 binding in human embryonic stems cell; PolyA RNA expression in CD4+ T cells( with and without JQ1 treatment) using RNA-seq
2012-11-14 | E-GEOD-33281 | biostudies-arrayexpress