Dataset Information

Diverse epigenetic strategies interact to control epidermal differentiation [ChIP-Seq]

ABSTRACT: It is becoming clear that interconnected functional gene networks, rather than single genes in isolation, govern stem cell self-renewal and differentiation. To identify potential epigenetic networks that impact on human epidermal stem cells we performed siRNA based genetic screens for 332 chromatin modifiers. We developed a Bayesian mixture model to predict putative functional interactions between those epigenetic modifiers that regulated differentiation. This allowed us to discover a network of genetic interactions involving EZH2, UHRF1 (both known to regulate epidermal self-renewal), ING5 (a MORF complex component), BPTF and SMARCA5 (NURF complex components). Genome-wide localisation and global mRNA expression analysis revealed that these factors impact two distinct but functionally related gene sets, including integrin extracellular matrix receptors that mediate anchorage of epidermal stem cells to their niche. Using a competitive epidermal reconstitution assay we confirmed that ING5, BPTF, SMARCA5, EZH2 and UHRF1 control differentiation under physiological conditions. Thus, regulation of distinct gene expression programs through the interplay between diverse epigenetic strategies protects epidermal stem cells from differentiation.

ORGANISM(S): Homo sapiens

PROVIDER: GSE34556 | GEO | 2012/06/24

SECONDARY ACCESSION(S): PRJNA156425

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:BACKGROUND: The polycomb group protein Ezh2 is an epigenetic repressor of transcription originally found to prevent untimely differentiation of pluripotent embryonic stem cells. We previously demonstrated that Ezh2 is also expressed in multipotent neural stem cells (NSCs). We showed that Ezh2 expression is downregulated during NSC differentiation into astrocytes or neurons. However, high levels of Ezh2 remained present in differentiating oligodendrocytes until myelinating. This study aimed to elucidate the target genes of Ezh2 in NSCs and in premyelinating oligodendrocytes (pOLs). METHODOLOGY/PRINCIPAL FINDINGS: We performed chromatin immunoprecipitation followed by high-throughput sequencing to detect the target genes of Ezh2 in NSCs and pOLs. We found 1532 target genes of Ezh2 in NSCs. During NSC differentiation, the occupancy of these genes by Ezh2 was alleviated. However, when the NSCs differentiated into oligodendrocytes, 393 of these genes remained targets of Ezh2. Analysis of the target genes indicated that the repressive activity of Ezh2 in NSCs concerns genes involved in stem cell maintenance, in cell cycle control and in preventing neural differentiation. Among the genes in pOLs that were still repressed by Ezh2 were most prominently those associated with neuronal and astrocytic committed cell lineages. Suppression of Ezh2 activity in NSCs caused loss of stem cell characteristics, blocked their proliferation and ultimately induced apoptosis. Suppression of Ezh2 activity in pOLs resulted in derangement of the oligodendrocytic phenotype, due to re-expression of neuronal and astrocytic genes, and ultimately in apoptosis. CONCLUSIONS/SIGNIFICANCE: Our data indicate that the epigenetic repressor Ezh2 in NSCs is crucial for proliferative activity and maintenance of neural stemness. During differentiation towards oligodendrocytes, Ezh2 repression continues particularly to suppress other neural fate choices. Ezh2 is completely downregulated during differentiation towards neurons and astrocytes allowing transcription of these differentiation programs. The specific fate choice towards astrocytes or neurons is apparently controlled by epigenetic regulators other than Ezh2. Examination of Ezh2 target sites in 2 different primary cells types

Dataset Information

Diverse epigenetic strategies interact to control epidermal differentiation [ChIP-Seq]

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure