Chd2 knockout effect on chromatin remodelling and the expression of developmental genes in mouse embryonic stem cells (ChIP-Seq)
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ABSTRACT: We demonstrate that chromodomain helicase DNA-binding domain 2 (Chd2) is required to maintain the differentiation potential of mouse ESCs. Chd2-depleted ESCs showed suppressed expression of developmentally regulated genes upon differentiation and subsequent differentiation defects without affecting gene expression in the undifferentiated state. Furthermore, chromatin immunoprecipitation followed by sequencing revealed alterations in a proportion of nucleosomes of developmentally regulated genes in Chd2-depleted ESCs to enhance histone variant H3.3 enrichment, leading to elevated trimethylation of histone H3 lysine 27.Chd2 is essential to prevent suppressive chromatin formation in developmentally regulated genes and determines subsequent effects on developmental processes in the undifferentiated state.
Project description:We demonstrate that chromodomain helicase DNA-binding domain 2 (Chd2) is required to maintain the differentiation potential of mouse ESCs. Chd2-depleted ESCs showed suppressed expression of developmentally regulated genes upon differentiation and subsequent differentiation defects without affecting gene expression in the undifferentiated state. Furthermore, chromatin immunoprecipitation followed by sequencing revealed alterations in a proportion of nucleosomes of developmentally regulated genes in Chd2-depleted ESCs to enhance histone variant H3.3 enrichment, leading to elevated trimethylation of histone H3 lysine 27.Chd2 is essential to prevent suppressive chromatin formation in developmentally regulated genes and determines subsequent effects on developmental processes in the undifferentiated state.
Project description:Long noncoding RNAs (lncRNAs) are enriched in regions flanking transcription- and chromatin-associated genes, but the functional importance of such co-location events is largely unclear. Chromodomain helicase DNA binding protein 2 (Chd2) is chromatin remodeller with various reported functions in cell differentiation and DNA damage response. Heterozygous mutations in human CHD2 have been implicated in epilepsy, neurodevelopmental delay, and intellectual disability. Here we show that Chaser, a highly conserved long noncoding RNA transcribed from a region in close proximity to the transcription start site of Chd2 and on the same strand, acts in concert with the CHD2 protein to maintain proper Chd2 expression levels. Loss of Chaser in mice leads to substantially increased levels of Chd2 mRNA and protein in the embryo and in adult tissues, early postnatal lethality in homozygous animals, and severe growth retardation in heterozygotes. Mechanistically, over-production of Chd2 induced by loss of Chaser leads to increased transcriptional interference by inhibiting promoters found downstream of highly expressed genes. We further show that Chaser production represses Chd2 expression solely in cis, and the phenotypic consequences of Chaser loss are rescued when Chd2 is perturbed as well. Targeting Chaser is thus a potentially viable strategy for increasing CHD2 levels in haploinsufficient individuals.
Project description:Chromodomain Helicase DNA-binding Domain 2 (CHD2), as a chromatin remodeling factor, was shown to be involved in the regulation of gene expression in embryonic development, neurodevelopment and myelopoiesis. However, its role in male germ cell development has not been elucidated. Here, we confirmed that CHD2 is abundantly expressed throughout the male germ cells with the highest expression in the spermatocytes of meiosis I. By constructing a heterozygous gene knockout mouse model of Chd2 (Chd2+/-), we demonstrated that CHD2 haploinsufficiency resulted in testicular developmental delay and increased rate of abnormal sperm in mice. DNA damage repair, synapsis and cell proliferation during spermatogenesis are impaired in Chd2+/- mice. In vitro experiments in C18-4 and GC-1 spg cells showed that CHD2 knockdown inhibits spermatogonial self-renewal. Mechanically, CHD2 maintained the enrichment of H3K4me3 in Ccnb1 and Ccnd2 promoter consequently promoting the transcription of Ccnb1 and Ccnd2. In addition, by interacting with cleavage stimulation factor CSTF3, CHD2 binds Oct4, Plzf mRNA and upregulates the expression of OCT4 and PLZF by improving mRNA stability. This is the first time to reveal the role and mechanism of CHD2 in maintaining spermatogonial self-renewal by promoting chromatin activity and mRNA stability in spermatogenesis.
Project description:Considerable evidence suggests loss of function mutations in the chromatin remodeler, CHD2, contribute to a broad spectrum of human neurodevelopmental disorders. However, it is unknown how CHD2 mutations lead to impaired brain function. Here we report mice with heterozygous mutations in Chd2 exhibit deficits in neuron proliferation and a shift in neuronal excitability that included divergent changes in excitatory and inhibitory synaptic function. Further in vivo experiments show Chd2+/- mice displayed aberrant cortical rhythmogenesis and severe deficits in long-term memory, consistent with phenotypes observed in humans. We identified broad, age-dependent transcriptional changes in Chd2+/- mice, including alterations in neurogenesis, synaptic transmission and disease-related genes. Deficits in interneuron density and memory caused by Chd2+/- were reproduced by Chd2 mutation restricted to a subset of inhibitory neurons and corrected by interneuron transplantation. Our results provide initial insight into how Chd2 haploinsufficiency leads to aberrant cortical network function and impaired memory.
Project description:Polycomb repressive complex 2 (PRC2) regulates gene expression during lineage specification through trimethylation of lysine 27 on histone H3 (H3K27me3). In Drosophila, polycomb binding sites are dynamic chromatin regions coupled to incorporation of the histone variant H3.3. Here we show in mouse embryonic stem cells (ESCs) that H3.3 is required for proper establishment of H3K27me3 at the promoters of developmentally regulated genes. These promoters show reduced dynamics as determined by deposition of de novo synthesized histones, associated with reduced PRC2 occupancy. H3.3-depleted ESCs show upregulation of extraembryonic trophectoderm, as well as misregulation of other developmental genes upon differentiation. Our data demonstrate the importance of H3.3 incorporation in ESCs and suggest that changes in chromatin dynamics in its absence lead to misregulation of gene expression during differentiation. Moreover, our findings lend support to the emerging notion that H3.3 has multiple functions in distinct genomic locations that are not always correlated with an “active” chromatin state. Native ChIP analysis of three histone post-translational modifications (H3K4me3, H3K27me3, H3K27ac) in two mouse embryonic stem cell (ESC) lines (control and H3.3-depleted). Inputs sequenced as control. Native ChIP analysis of H3.3B-HA in control and Suz12-/- ESCs. Crosslinking ChIP analysis of histone H3 using a general H3 antibody in two ESC lines (control and H3.3-depleted). Crosslinking ChIP analysis Hira, UTX, and Jmjd3 in wild type and H3.3 KO ESCs.
Project description:Chromodomain Helicase DNA-binding Domain 2 (CHD2), as a chromatin remodeling factor, was shown to be involved in the regulation of gene expression in embryonic development, neurodevelopment and myelopoiesis. However, its role in male germ cell development has not been elucidated. Here, we confirmed that CHD2 is abundantly expressed throughout the male germ cells with the highest expression in the spermatocytes of meiosis I. By constructing a heterozygous gene knockout mouse model of Chd2 (Chd2+/-), we demonstrated that CHD2 haploinsufficiency resulted in testicular developmental delay and increased rate of abnormal sperm in mice. DNA damage repair, synapsis and cell proliferation during spermatogenesis are impaired in Chd2+/- mice. In vitro experiments in C18-4 and GC-1 spg cells showed that CHD2 knockdown inhibits spermatogonial self-renewal. Mechanically, CHD2 maintained the enrichment of H3K4me3 in Ccnb1 and Ccnd2 promoter consequently promoting the transcription of Ccnb1 and Ccnd2. In addition, by interacting with cleavage stimulation factor CSTF3, CHD2 binds Oct4, Plzf mRNA and upregulates the expression of OCT4 and PLZF by improving mRNA stability. This is the first time to reveal the role and mechanism of CHD2 in maintaining spermatogonial self-renewal by promoting chromatin activity and mRNA stability in spermatogenesis.
Project description:Background: Mutations in the chromatin remodelling protein CHD2 have been strongly associated with multiple neurodevelopmental disorders. However the precise function of CHD2 through neuronal development remains largely uncharacterized. Methods: We have used our protocol for generating cortical interneurons from human embryonic stem cells to study the role of CHD2 in brain development Results: This work found that CHD2 binding is largely associated with open and active chromatin Conclusions: As CHD2 plays distinct roles in several aspects of interneuron development, pathogenic CHD2 mutations have high potential to disrupt one or more of these events, contributing to NDDs.
Project description:Human embryonic stem cells (hESCs) were specified as ventral telencephalic neuroectoderm (day 4) and then into medial ganglionic emininence (MGE)-like progenitors (day 15) and were subsequently differentiated into cortical interneuron (cIN)-like cells (day 25-35), by modification of previously published protocols. RNA-seq analysis at days 0, 4, 15, 25, and 35 defined transcriptome signatures for MGE and cIN cell identity. Further integration of these gene expression signatures with ChIP-seq for the NKX2-1 transcription factor in MGE-like progenitors defined NKX2-1 putative direct targets, including genes involved in both MGE specification and in several aspects of later cIN differentiation (migration, synaptic function). Among the NKX2-1 direct targets with MGE and cIN enriched expression was CHD2, a chromatin remodeling protein. Since CHD2 haploinsufficiency can cause epilepsy and/or autism, which can involve altered cIN development or function, we evaluated CHD2 requirements in these processes. Transcriptome changes were evaluated in CHD2 knockdown MGE-like progenitors at day 15, revealing diminished expression of genes involved in MGE specification and cIN differentiation including channel and synaptic genes implicated in epilepsy, while later cIN electrophysiological properties were also altered. We defined some shared cis-regulatory elements bound by both NKX2-1 and CHD2 and characterized their ability to cooperatively regulate cIN gene transcription through these elements. We used these data to construct regulatory networks underlying MGE specification and cIN differentiation and to define requirements for CHD2 and its ability to cofunction with NKX2-1 in this process.
Project description:High-grade gliomas (HGG) are deadly diseases for both adult and pediatric patients. Recently, it has been shown that neuronal activity promotes the progression of multiple subgroups of HGG. However, epigenetic mechanisms that govern this process remain elusive. Here we report that the chromatin remodeler CHD2 regulates neuron-glioma interactions in diffuse midline glioma (DMG) characterized by onco-histone H3.1K27M. Depletion of CHD2 in H3.1K27M DMG cells compromises cell viability and neuron-to-glioma synaptic connections in vitro, neuron-induced proliferation of H3.1K27M HGG DMG cells in vitro and in vivo, activity-dependent calcium transients in vivo, and extends the survival of H3.1K27M DMG-bearing mice. Mechanistically, CHD2 coordinates with the transcription factor FOSL1 to control the expression of axon-guidance and synaptic genes in H3.1K27M DMG cells. Together, our study reveals a mechanism whereby CHD2 controls the intrinsic gene program of the H3.1K27M DMG subtype, which in turn regulates the tumor growth-promoting interactions of glioma cells with neurons.
Project description:Polycomb repressive complex 2 (PRC2) regulates gene expression during lineage specification through trimethylation of lysine 27 on histone H3 (H3K27me3). In Drosophila, polycomb binding sites are dynamic chromatin regions coupled to incorporation of the histone variant H3.3. Here we show in mouse embryonic stem cells (ESCs) that H3.3 is required for proper establishment of H3K27me3 at the promoters of developmentally regulated genes. These promoters show reduced dynamics as determined by deposition of de novo synthesized histones, associated with reduced PRC2 occupancy. H3.3-depleted ESCs show upregulation of extraembryonic trophectoderm, as well as misregulation of other developmental genes upon differentiation. Our data demonstrate the importance of H3.3 incorporation in ESCs and suggest that changes in chromatin dynamics in its absence lead to misregulation of gene expression during differentiation. Moreover, our findings lend support to the emerging notion that H3.3 has multiple functions in distinct genomic locations that are not always correlated with an “active” chromatin state. RNA-seq analysis of three embryonic stem cell lines (control, H3.3 KD1, and H3.3 KD2)