Heterochromatin spreading in cancer cells through HDAC7 mediated histone H3.3 landscape reprogramming [RNA-seq]
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE286177 | GEO | 2026/01/07
REPOSITORIES: GEO
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Project description:Specific inhibition of HDAC7 expression with subtype specific siRNAs results in inhibition of the interaction of H3.3 with HIRA, while the association of H3.3 with DAXX and H3K9me3 is significantly increased, resulting in H3.3 being deposited on H3K9me3+/DAPI+ heterochromatin nuclear foci with observed changes in RNA expression. Inhibition of HDAC7 triggers a significant increase of heterochromatin marks H3K9me3 and H3K27me3, global heterochromatin spreading in cancer cells, and reprogramming of the H3.3 chromatin landscape. We performed H3K9me3 chip-seq in glioma stem cells following HDAC7 knockdown in order to identify specific sites of heterochromatin spreading and/or increased occupancy.
2026-01-07 | GSE286176 | GEO
Project description:Title of Publication: Histone Deacetylase 7 Regulates Cell Survival and TCR Signaling in CD4/CD8 Double-Positive Thymocytes Abstract of publicaton: CD4/CD8 double-positive (DP) thymocytes express the transcriptional repressor Histone Deacetylase 7 (HDAC7), a class IIa HDAC that is exported from the cell nucleus after T cell receptor (TCR) engagement. Through signal-dependent nuclear export, class IIa HDACs such as HDAC7 mediate signal-dependent changes in gene expression that are important to developmental fate decisions in multiple tissues. We report that HDAC7 is exported from the cell nucleus during positive selection in thymocytes, and regulates genes mediating the coupling between TCR engagement and downstream events that determine cell survival. Thymocytes lacking HDAC7 are inefficiently positively selected due to a severely shortened lifespan and exhibit a truncated repertoire of TCR J segments. The expression of multiple important mediators and modulators of the response to TCR engagement is altered in HDAC7-deficient thymocytes, resulting in increased tonic MAP kinase activity that contributes to the observed loss of viability. Remarkably, the activity of Protein Kinase D, the kinase that mediates nuclear export of HDAC7 in response to TCR signaling, is also increased in HDAC7-deficient thymocytes, suggesting that HDAC7 nuclear export governs a self-sustaining auto-excitatory loop. These experiments add to the understanding of the life/death decision in thymic T cell development, define a novel function for class IIa HDACs, and point to a novel feed-forward mechanism whereby these molecules regulate their own state and mediate stable developmental transitions. Goal of Microarray experiment: We did these experiments to determine how alteration of the function of HDAC7, a site-specific and signal-dependent repressor of transcription, changes gene expression in CD4/CD8 DP thymocytes. Three biological replicate samples were prepared for each non-wild type mouse strain (Samples 7-18). Six biological replicates were prepared for the wild type strain (Samples 1-6). Total RNA was prepared from isolated CD4/CD8 Double-positive thymocytes and labeled with the Affymetrix Whole-Transcript labeling protocol. Labeled probes were hybridized to one Affymetrix Mouse Gene 1.0ST array each. Data from .cel files were normalized using RMA, in normalization groups representing each of the binary comparisons made. These binary comparisons between sample groups represent gene expression changes due to loss of HDAC7 (samples 1-3 vs. 7-9), transgenic expression of an HDAC7-VP16 fusion protein (samples 4-6 vs. 10-12), positive thymic selection (samples 1-6 vs. samples 11-15), and negative thymic selection (Samples 11-15 vs. samples 16-18).
2011-04-06 | E-GEOD-26488 | biostudies-arrayexpress
Project description:Histone deacetylases (HDACs) are long recognized for important functions in regulating gene transcription in biology and diseases. However, unlike for ubiquitously expressed class I HDACs, we have little mechanistic understanding of class II HDACs that have postulated tissue specific functions. Here we report that class IIa Hdac4 and Hdac7 are up-regulated in transcription through IL-6-Stat3 signaling selectively in mouse T-helper 17 (Th17) cells during lineage-specific differentiation, but not in Th1, Th2, and Treg subtypes. Genetic knockout of Hdac4 or Hdac7 established their importance for Th17 differentiation with different functional mechanisms. Hdac4 works with Th17 transcription factors JunB-Irf4-Batf for transcriptional activation of Th17 signature genes Il17a/f, whereas Hdac7 acts distinctively in concert with Aiolos/Ncor1/Hdac3 co-repressor complex for transcriptional repression of Th17 negative regulators including Il2. Pharmacological inhibition or gene knockout of Hdac4 and Hdac7 ameliorates development of T-cell transfer induced colitis and experimental autoimmune encephalomyelitis (EAE) in mice through blockage of Th17 cell development in colon and central nervous system that recapitulate inflammatory bowel diseases and multiple sclerosis in humans, respectively. Our study highlights a previously unknown distinct mechanisms of Hdac4 and Hdac7 in transcriptional control of Th17 cell development, and rationalizes a new therapeutic strategy of targeting class IIa HDAC4/7 for the treatment of Th17-related inflammatory and autoimmune diseases.
2023-02-03 | GSE144830 | GEO
Project description:Abstract of publicaton: CD4/CD8 double-positive (DP) thymocytes express the transcriptional repressor Histone Deacetylase 7 (HDAC7), a class IIa HDAC that is exported from the cell nucleus after T cell receptor (TCR) engagement. Through signal-dependent nuclear export, class IIa HDACs such as HDAC7 mediate signal-dependent changes in gene expression that are important to developmental fate decisions in multiple tissues. We report that HDAC7 is exported from the cell nucleus during positive selection in thymocytes, and regulates genes mediating the coupling between TCR engagement and downstream events that determine cell survival. Thymocytes lacking HDAC7 are inefficiently positively selected due to a severely shortened lifespan and exhibit a truncated repertoire of TCR Jalpha segments. The expression of multiple important mediators and modulators of the response to TCR engagement is altered in HDAC7-deficient thymocytes, resulting in increased tonic MAP kinase activity that contributes to the observed loss of viability. Remarkably, the activity of Protein Kinase D, the kinase that mediates nuclear export of HDAC7 in response to TCR signaling, is also increased in HDAC7-deficient thymocytes, suggesting that HDAC7 nuclear export governs a self-sustaining auto-excitatory loop. These experiments add to the understanding of the life/death decision in thymic T cell development, define a novel function for class IIa HDACs, and point to a novel feed-forward mechanism whereby these molecules regulate their own state and mediate stable developmental transitions. Title of manuscript: Nuclear Export of Histone Deacetylase 7 During Thymic Selection Mediates Immune Self-tolerance. abstract of manuscript: Histone Deacetylase 7 (HDAC7) is a TCR signal-dependent regulator of differentiation that is highly expressed in CD4/CD8 double-positive (DP) thymocytes. Here we examine the effect of blocking TCR-dependent nuclear export of HDAC7 during thymic selection, through expression of a signal-resistant mutant of HDAC7 (HDAC7-?P) in thymocytes. We find that HDAC7-?P Transgenic thymocytes exhibit a profound block in negative thymic selection, but can still undergo positive selection, resulting in the escape of autoreactive T cells into the periphery. Gene expression profiling reveals a comprehensive suppression of the negative selection-associated gene expression program in DP thymocytes, associated with a defect in the activation of MAP kinase pathways by TCR signals. The consequence of this block in vivo is a lethal autoimmune syndrome involving the exocrine pancreas and other abdominal organs. These experiments establish a novel molecular model of autoimmunity and cast new light on the relationship between thymic selection and immune self-tolerance. Goal of Microarray experiment: We did these experiments to determine how alteration of the function of HDAC7, a site-specific and signal-dependent repressor of transcription, changes gene expression in CD4/CD8 DP thymocytes.
2011-04-06 | GSE26488 | GEO
Project description:Histone chaperones are responsible for the deposition and removal of histones in chromatin and critical to prevent the abnormal activation of retrotransposable elements, which can be harmful to genome stability. One of the important histone chaperones is HIRA complex, which consists of Hira, Ubn1/Ubn2, and Cabin1 and mediates the installment of H3.3-H4 to nucleosome. We studied the function of members of HIRA complex in suppressing ERVs and found that histone H3.3 are enriched on all three classes of ERVs. Different HIRA members act distinctly in silencing ERVs. Ubn2 represses Class III ERVs including MERVL and Hira mainly silences Class I and Class II ERVs. Hira is enriched on Class I and II ERVs whereas its depletion affects the recruitment of H3.3. In contrast, Ubn2 is enriched on Class III ERVs, while its depletion influences H3.3 deposition and H3K9 methylation. This study extends our understandings of the mechanism by novel factors regulates ERVs.
2021-12-12 | GSE177026 | GEO
Project description:B lymphopoiesis is the result of several cell lineage choices and differentiation steps whose perturbation leads to B cell malignancies. Cellular transitions for B cell generation have been associated with gene activation and silencing by networks of B cell specific transcription factors (TFs) and dynamic changes in DNA methylation. How gene repression is established and which lineage-specific transcriptional repressors are involved during B cell lymphopoiesis are still not totally understood. Here, by using our in vivo experimental approach, we have found that HDAC7 represses Tet2 enzyme in pro-B cells. In fact, HDAC7 deficient pro-B cells show a significant increase in the percentage of global 5-hydroxymethylation. To prove the role of HDAC7 in 5-hydroxymethylation, we have performed a genome-wide experimental approach. hMeDIP-sequencing experiments reveal an increase in the enrichment of this epigenetic modification at many loci related to lineage inappropriate genes. Our results corroborate that HDAC7 is an essential transcriptional regulator during early B cell development that silences lineage or functionally inappropriate genes and unveil an unexpected role of a class IIa HDAC in controlling DNA methylation
2022-06-28 | GSE135263 | GEO
Project description:The HIRA chaperone complex, comprised of HIRA, UBN1 and CABIN1, collaborates with histone-binding protein ASF1a to incorporate histone variant H3.3 into chromatin in a DNA replication-independent manner. To better understand its function and mechanism, we integrated HIRA, UBN1, ASF1a and histone H3.3 ChIP-seq and gene expression analyses. Most HIRA-binding sites co-localize with UBN1, ASF1a and H3.3 at active promoters and active and weak/poised enhancers. At promoters, binding of HIRA/UBN1/ASF1a correlates with the level of gene expression. HIRA is required for deposition of histone H3.3 at its binding sites. There are marked differences in nucleosome and co-regulator composition at different classes of HIRA-bound regulatory site. Underscoring this, we report novel physical interactions between the HIRA complex and transcription factors, a chromatin insulator and an ATP-dependent chromatin-remodelling complex. Our results map the distribution of the HIRA chaperone across the chromatin landscape and point to different interacting partners at functionally distinct regulatory sites. Examination of H3.3 histone modification in HeLA cells with accompanying FAIRE data
2013-04-18 | E-GEOD-45023 | biostudies-arrayexpress
Project description:The HIRA chaperone complex, comprised of HIRA, UBN1 and CABIN1, collaborates with histone-binding protein ASF1a to incorporate histone variant H3.3 into chromatin in a DNA replication-independent manner. To better understand its function and mechanism, we integrated HIRA, UBN1, ASF1a and histone H3.3 ChIP-seq and gene expression analyses. Most HIRA-binding sites co-localize with UBN1, ASF1a and H3.3 at active promoters and active and weak/poised enhancers. At promoters, binding of HIRA/UBN1/ASF1a correlates with the level of gene expression. HIRA is required for deposition of histone H3.3 at its binding sites. There are marked differences in nucleosome and co-regulator composition at different classes of HIRA-bound regulatory site. Underscoring this, we report novel physical interactions between the HIRA complex and transcription factors, a chromatin insulator and an ATP-dependent chromatin-remodelling complex. Our results map the distribution of the HIRA chaperone across the chromatin landscape and point to different interacting partners at functionally distinct regulatory sites. Examination of 3 histone chaperone proteins in HeLa cells
2013-04-18 | E-GEOD-45024 | biostudies-arrayexpress
Project description:Histone chaperones and chromatin remodelers control nucleosome dynamics, essential for transcription, replication, and DNA repair. The histone chaperone Anti-Silencing Factor 1 (ASF1) plays a central role in facilitating CAF-1-mediated replication-dependent H3.1 deposition and HIRA-mediated replication-independent H3.3 deposition in yeast and metazoans. Whether ASF1 function is evolutionarily conserved in plants is unknown. Here, we show that Arabidopsis ASF1 proteins display an exclusive preference for the H3.3-depositing HIRA complex. Simultaneous mutation of both Arabidopsis ASF1 genes caused a decrease in chromatin density and ectopic H3.1 occupancy at loci typically enriched with H3.3. Genetic, transcriptomic, and proteomic data indicate that ASF1 proteins strongly prefer the HIRA complex over CAF-1. asf1 mutants also displayed an increase in spurious Pol II transcriptional initiation, and showed defects in the maintenance of gene body CG DNA methylation and in the distribution of histone modifications. Furthermore, ectopic targeting of ASF1 caused excessive histone deposition, less accessible chromatin, and gene silencing. These findings reveal the importance of ASF1-mediated H3.3-H4 deposition via the HIRA pathway for proper epigenetic regulation of the genome.
2022-10-31 | PXD035578 | Pride
Project description:Establishment of a proper chromatin landscape is central to genome function. Here, we explain H3 variant distribution by specific targeting and dynamics of deposition involving the CAF-1 and HIRA histone chaperones. Impairing replicative H3.1 incorporation via CAF-1 enables an alternative H3.3 deposition at replication sites via HIRA. Conversely, the H3.3 incorporation throughout the cell cycle via HIRA cannot be replaced by H3.1. ChIP-seq analyses reveal correlation between HIRA-dependent H3.3 accumulation and RNA pol II at transcription sites and specific regulatory elements, further supported by their biochemical association. Remarkably, the HIRA complex shows unique DNA binding properties and depleting HIRA increases DNA sensitivity to nucleases. We propose that protective gap-filling of naked DNA by HIRA leads to a broad distribution of H3.3, and HIRA association with Pol II ensures local H3.3 enrichment at specific sites. Examination of genome-wide localization of two histone H3 variants.
2011-12-16 | E-GEOD-31794 | biostudies-arrayexpress