Combinatorial targeting of a novel MET/EMT network components by macroH2A variants safeguards cell identity.
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ABSTRACT:
PROVIDER: PRJNA891225 | ENA |
REPOSITORIES: ENA
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Project description:The establishment and maintenance of cellular identity rely upon the precise coordination of regulatory pathways culminating to the proper execution of cell type-specific gene expression programs. Generation of induced pluripotent stem cells (iPSCs) from highly specialized cell types provides an excellent model system to study how cells maintain their stability through the functional interplay of transcription factors and chromatin structure, and how they can change identity, especially in the context of disease. Previous studies have shown that chromatin structure safeguards cell identity by acting as a barrier to reprogramming. Here, we investigated the mechanisms of how the histone variant macroH2A inhibits reprogramming by interfering with the mesenchyme to epithelial transition, a step that is a prerequisite for reprogramming of mouse embryonic fibroblasts. We found that each of the macroH2A isoforms regulates the expression of defined sets of genes, whose overall function is to stabilize the mesenchyme phenotype, thus resisting reprogramming. We identified a novel gene network (MSCN, mesenchyme network) composed of 63 macroH2A-regulated genes encoding proteins of the extracellular matrix, cell membrane, cytoplasmic signal integrators and the transcriptional regulators Id2 and Snai2, all of which can function as key controllers of the mesenchyme phenotype. Functional studies including ChIP-seq and KD experiments using any one of the individual macroH2A isoforms revealed an isoform-specific combinatorial targeting of the genes that reconstruct the MSCN. Our findings established that the combinatorial macroH2A targeting of the MSCN components safeguards cell identity and demonstrated its pivotal role in maintaining the differentiated cell phenotype by generating robustness in gene expression programs to resist cellular reprogramming.
2023-06-21 | GSE215883 | GEO
Project description:The establishment and maintenance of cellular identity rely upon the precise coordination of regulatory pathways culminating to the proper execution of cell type-specific gene expression programs. Generation of induced pluripotent stem cells (iPSCs) from highly specialized cell types provides an excellent model system to study how cells maintain their stability through the functional interplay of transcription factors and chromatin structure, and how they can change identity, especially in the context of disease. Previous studies have shown that chromatin structure safeguards cell identity by acting as a barrier to reprogramming. Here, we investigated the mechanisms of how the histone variant macroH2A inhibits reprogramming by interfering with the mesenchyme to epithelial transition, a step that is a prerequisite for reprogramming of mouse embryonic fibroblasts. We found that each of the macroH2A isoforms regulates the expression of defined sets of genes, whose overall function is to stabilize the mesenchyme phenotype, thus resisting reprogramming. We identified a novel gene network (MSCN, mesenchyme network) composed of 63 macroH2A-regulated genes encoding proteins of the extracellular matrix, cell membrane, cytoplasmic signal integrators and the transcriptional regulators Id2 and Snai2, all of which can function as key controllers of the mesenchyme phenotype. Functional studies including ChIP-seq and KD experiments using any one of the individual macroH2A isoforms revealed an isoform-specific combinatorial targeting of the genes that reconstruct the MSCN. Our findings established that the combinatorial macroH2A targeting of the MSCN components safeguards cell identity and demonstrated its pivotal role in maintaining the differentiated cell phenotype by generating robustness in gene expression programs to resist cellular reprogramming.
2023-06-21 | GSE215884 | GEO
Project description:Combinatorial targeting of a novel MET/EMT network components by macroH2A variants safeguards cell identity [RNA-seq]
| PRJNA891229 | ENA
Project description:Combinatorial targeting of a novel MET/EMT network components by macroH2A variants safeguards cell identity [ChIP-seq]
| PRJNA891232 | ENA
Project description:Generation of induced pluripotent stem cells from specialized cell types provides an excellent model to study how cells maintain their stability, and how they can change identity, especially in the context of disease. Previous studies have shown that chromatin safeguards cell identity by acting as a barrier to reprogramming. We investigated mechanisms by which the histone macroH2A variants inhibit reprogramming and discovered that they work as gate keepers of the mesenchymal cell state by blocking epithelial transition, a step required for reprogramming of mouse fibroblasts. More specifically, we found that individual macroH2A variants regulate the expression of defined sets of genes, whose overall function is to stabilize the mesenchymal gene expression program, thus resisting reprogramming. We identified a novel gene network (MSCN, mesenchymal network) composed of 63 macroH2A-regulated genes related to extracellular matrix, cell membrane, signaling and the transcriptional regulators Id2 and Snai2, all of which function as guardians of the mesenchymal phenotype. ChIP-seq and KD experiments revealed a macroH2A variant-specific combinatorial targeting of the genes reconstructing the MSCN, thus generating robustness in gene expression programs to resist cellular reprogramming.
| S-EPMC10335705 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2023-06-21 | GSE215885 | GEO
Project description:MacroH2As core histone variants have a unique structure that includes C-terminal nonhistone domain. MacroH2As are highly conserved in vertebrates, and are thought to regulate gene expression. However the nature of genes regulated by macroH2As and the biological significance of macroH2As for the organism remain unclear. Our gene expression studies indicate that macroH2A.1 and macroH2A.2 work together to regulate specific genes. In these studies we examine the distributions of macroH2A.1 and macroH2A.2 nucleosomes to determine if they are localized to the genes that show altered expression in macroH2A knockout mouse liver. MacroH2A.1 and macroH2A.2 nucleosomes prepared from ~ 50 fetal mouse livers were purified by thio-affinity chromatography. Five samples were sequenced: Thiopropyl Sepharose, Normal Liver - contains mononucleosomal DNA from macroH2A.1-containing nucleosomes; Activate Thiol Sepharose, Normal Liver - contains mononucleosomal DNA primarily from macroH2A.2-containing nucleosomes. Starting Material, Normal Liver - this is a reference samplefor the first two samples. It contains mononucleosomal DNA from bulk fetal liver chromatin. Activated Thiol Sepharose, Knockout Livers - this is a control sample that contains mononucleosomal DNA from non-macroH2A nucleosomes that contaminate the macroH2A.2 nucleosomes. This fraction was prepared from macroH2A1/2 double knockout fetal livers; Starting Material, Knockout Liver - this is a reference sample for the fourth sample. It contains mononucleosomal DNA from bulk chromatin prepared from macroH2A1/2 double knockout fetal livers.
2014-10-15 | E-GEOD-57796 | biostudies-arrayexpress
Project description:MacroH2As core histone variants have a unique structure that includes C-terminal nonhistone domain. MacroH2As are highly conserved in vertebrates, and are thought to regulate gene expression. However the nature of genes regulated by macroH2As and the biological significance of macroH2As for the organism remain unclear. Our gene expression studies indicate that macroH2A.1 and macroH2A.2 work together to regulate specific genes. In these studies we examine the distributions of macroH2A.1 and macroH2A.2 nucleosomes to determine if they are localized to the genes that show altered expression in macroH2A knockout mouse liver.
2014-10-15 | GSE57796 | GEO
Project description:Interaction proteomics in cell extracts on tagged macroH2A, either expressed in cells or using recombinant dimers with H2B.
2023-10-24 | PXD045696 | Pride
Project description:Genetic loss-of-function studies in development, cancer and somatic cell reprogramming have suggested that the group of macroH2A histone variants might function through stabilizing the differentiated state by a yet unknown mechanism. Here, we present results demonstrating that macroH2A variants have a major function in maintaining nuclear organization and heterochromatin architecture. Specifically, we find that a substantial amount of macroH2A is associated with heterochromatic repeat sequences. We further identify macroH2A on sites of interstitial heterochromatin decorated by H3K9me3. Loss of macroH2A leads to major defects in nuclear organization including reduced nuclear circularity, disruption of nucleoli and a global loss of dense heterochromatin. Domains formed by repeat sequences when depleted of macroH2A are disorganized, expanded and fragmented and mildly re-expressed. On the molecular level we find that macroH2A is required for the interaction of repeat sequences with the nucleostructural protein Lamin B1. Taken together our results argue that a major function of macroH2A histone variants is to link nucleosome composition to higher order chromatin architecture.
2017-03-21 | GSE58175 | GEO