CHD7 is Suppressed in the Perinecrotic/Ischemic Microenvironment and is a Novel Regulator of Angiogenesis
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE119688 | GEO | 2018/10/31
REPOSITORIES: GEO
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Project description:CHD7 is Suppressed in the Perinecrotic/Ischemic Microenvironment and is a Novel Regulator of Angiogenesis
| PRJNA489973 | ENA
Project description:Tumorigenic and non-neoplastic tissue injury occurs via the ischemic microenvironment defined by low oxygen, pH, and nutrients due to blood supply malfunction. Ischemic conditions exist within regions of pseudopalisading necrosis, a pathological hallmark of glioblastoma (GBM), the most common primary malignant brain tumor in adults. To recapitulate the physiologic microenvironment found in GBM tumors and tissue injury, we developed an in vitro ischemic model and identified chromodomain helicase DNA-binding protein 7 (CHD7) as a novel ischemia-regulated gene. Point mutations in the CHD7 gene are causal in CHARGE syndrome (a developmental disorder causing coloboma, heart defects, atresia choanae, retardation of growth, and genital and ear anomalies) and interrupt the epigenetic functions of CHD7 in regulating neural stem cell maintenance and development. Using our ischemic system, we observed microenvironment-mediated decreases in CHD7 expression in brain tumor-initiating cells and neural stem cells. Validating our approach, CHD7 was suppressed in the perinecrotic niche of GBM patient and xenograft sections, and an interrogation of patient gene expression datasets determined correlations of low CHD7 with increasing glioma grade and worse patient outcomes. Segregation of GBM by molecular subtype revealed a novel observation that CHD7 expression is elevated in proneural versus mesenchymal GBM. Genetic targeting of CHD7 and subsequent gene ontology analysis of RNA sequencing data indicated angiogenesis as a primary biological function affected by CHD7 expression changes. We validated this finding in tube-formation assays and vessel formation in orthotopic GBM models. Together, our data provide further understanding of molecular responses to ischemia and a novel function of CHD7 in regulating angiogenesis in both neoplastic and non-neoplastic systems. Stem Cells 2019;37:453-462.
| S-EPMC6596424 | biostudies-literature
Project description:CHD7 is a member of the chromodomain helicase DNA binding domain family of ATP-dependent chromatin remodeling enzymes. De novo mutation of the CHD7 gene is a major cause of CHARGE syndrome, a genetic disease characterized by a complex constellation of birth defects. To gain insight to the function of CHD7, we mapped the distribution of the CHD7 protein on chromatin using the approach of chromatin immunoprecipitation on tiled microarrays (ChIP-chip). These studies were performed in human colorectal carcinoma cells, human neuroblastoma cells, and mouse embryonic stem (ES) cells before and after differentiation into neural precursor cells. The results indicate that CHD7 localizes to discrete locations along chromatin that are specific to each cell type, and that the cell-specific binding of CHD7 correlates with a subset of histone H3 methylated at lysine 4 (H3K4me). The CHD7 sites change concomitantly with H3K4me patterns during ES cell differentiation, suggesting that H3K4me is part of the epigenetic signature that defines lineage-specific association of CHD7 with specific sites on chromatin. Furthermore, the CHD7 sites are predominantly located distal to transcription start sites, most often contained within DNase hypersensitive sites, frequently conserved, and near genes expressed at relatively high levels. These features are similar to those of gene enhancer elements, raising the possibility that CHD7 functions in enhancer mediated transcription, and that the congenital anomalies in CHARGE syndrome are due to alterations in transcription of tissue-specific genes normally regulated by CHD7 during development. ChIP-chip experiments were performed for CHD7 and H3K4 mono-,di-, and trimethylation modifications in 4 cells types: human DLD1 and SH-SY5Y; mouse ES and differentiated neural precursor cells derived from mouse ES cells. Microarrays used in these experiments tiled all or subset of ENCODE regions (in mouse, analogous ENCODE regions were assayed). At least two biological replicates were performed for each CHD7 ChIP experiment; H3K4 ChIP's were performed once in each cell type.
2009-01-22 | E-GEOD-14460 | biostudies-arrayexpress
Project description:Gene expression changes were measured between mouse ES cells of three genotypes: WT Chd7, Heterzygous Chd7 Null, Homozygous Chd7 Null. The hypothesis being tested was that CHD7, a chromatin remodeling protein, functions as a transcriptional regulator. This experiment was performed to detect gene targets of CHD7-mediated regulation. We report the genome-wide binding profile of CHD7, the protein implicated in CHARGE syndrome, in mouse ES cells using ChIP-Seq technology. Combining these data with other genomic datasets, we discover CHD7 to colocalize with other transcription factors including Oct4, Nanog, Sox2, and p300 at gene enhancer elements to regulate ES cell specific gene expression. Chd7 wildtype, heterozygous, and homozygous ES cells derived from preimplantation embryos were grown on feeder cells and total RNA was isolated using Trizol. The ratio of ES to feeder cells was estimated at 5:1. ChIP sequencing of CHD7 and p300 in mouse ES cells
2010-06-15 | E-GEOD-22341 | biostudies-arrayexpress
Project description:Mutations in the chromatin remodeller CHD7 cause CHARGE syndrome (CS). Importantly, children with CS exhibit moderate to severe neurological and behaviour symptoms including autism. However, the neural substrates underlying these symptoms remain largely unknown. Here we show that zebrafish chd7 mutant display a nighttime hyperactivity behavioural phenotype and exhibit altered number and positioning of GABAergic neurons in brain regions. Using a transcriptomic approach, we identified many genes involved in cell adhesion, migration and receptor signalling that are dysregulated in the chd7 brain. We also show an abnomal hyperactivation of ERK signalling contributing to the GABAergic defects. A phenotype-based screen of 3850 compounds identifies a lead compound, ephedrine that ameliorates GABAergic and behavioural anomalies in chd7 animals. Our study identifies CHD7 as critical regulator of GABAergic network development. Importantly, we provide novel insight into the mechanisms underlying the neurological deficits in CS and identify a new therapeutic for CS-associated neurobehavioural symptoms.
2019-10-31 | GSE139623 | GEO
Project description:Heterozygous loss-of function mutations in CHD7 (chromodomain helicase DNA-binding protein 7) lead to CHARGE syndrome, a complex developmental disorder affecting craniofacial structures, peripheral nerves and several organ systems like eyes, ears, nose and heart. Recently, it was demonstrated that CHD7 is essential for the formation of multipotent migratory neural crest cells, which migrate from the neural tube to many regions of the embryo, where they differentiate into various tissues including craniofacial and heart structures. So far only few CHD7 target genes involved in neural crest cell development have been identified and the role of CHD7 in neural crest cell guidance and the regulation of mesenchymal-epithelial transition is unknown. Therefore, we undertook a genome-wide microarray expression analysis on wild-type and CHD7 deficient (Chd7Whi/+ and Chd7Whi/Whi) mouse embryos at day 9.5, the time point of neural crest cell migration. We identified 98 genes showing greater than two fold differences in expression (log2 fold-change) and a P-value to false discovery rate (FDR) < 0.05 between wild-type and Chd7Whi/Whi embryos. Interestingly, many misregulated genes are involved in neural crest cell and axon guidance like semaphorins and ephrin receptors. By performing knockdown experiments for Chd7 and one of its target genes, namely semaphorin3a in Xenopus laevis embryos, we could show abnormalities in the migration of neural crest cells in vivo. Additionally, we detected non-synonymous SEMA3A variations in 3 out of 45 CHD7 negative CHARGE patients suggesting a role for SEMA3A in the pathogenesis of CHARGE syndrome. To identify genes that are affected by the absence of functional Chd7 at the time point of neural crest cell migration, the expression profiles of E9.5 wild-type, Chd7Whi/+ and Chd7Whi/Whi female mouse embryos were compared by whole-genome microarray analysis. Mouse embryos of the same sex were used to avoid sex-dependent gene expression effects. We performed microarray analysis by using the Agilent-026655 Whole Mouse Genome Microarray 4x44K v2 (Agilent) on four biological replicates from each group.
2014-07-01 | E-GEOD-46591 | biostudies-arrayexpress
Project description:Mutation of the gene encoding the ATP-dependent chromatin remodeler CHD7 causes CHARGE syndrome. The mechanisms underlying the neurodevelopmental deficits associated with the syndrome, which include cerebellar hypoplasia, developmental delay, coordination problems and autistic features, are not known. CHD7 is expressed in neural stem and progenitor cells, but its role in neurogenesis during brain development remains unknown. Here we show that deletion of Chd7 from cerebellar granule cell precursors (GCps) in the mouse results in reduced GCp proliferation, cerebellar hypoplasia, developmental delay and motor deficits. Genome-wide expression profiling revealed downregulated Reln gene expression in Chd7-deficient GCps. Recessive RELN mutations is associated with severe cerebellar hypoplasia in humans. We provide molecular and genetic evidence that reduced Reln expression contributes substantially to the GCp proliferative defect and cerebellar hypoplasia in GCp-specific Chd7 mouse mutants. Finally, we show that CHD7 is necessary for the maintenance of an open, accessible chromatin state at the Reln locus. Taken together, this study shows that Reln gene expression is regulated by chromatin remodeling, identifies CHD7 as a previously unrecognized upstream regulator of Reln and provides the first evidence that a mammalian CHD protein controls brain development by modulating chromatin accessibility in neuronal progenitors in vivo.
2017-01-01 | GSE90466 | GEO
Project description:Oligodendrocytes are generated from oligodendrocyte precursor cells (OPCs). Chd7 is ATP-dependent chromatin-remodeling enzyme. We performed microarray analysis to examine changes in gene expression between control and Chd7 knockdown OPCs. Results provide insight into the function of Chd7 in oligodendrocyte development.
2018-03-01 | GSE95347 | GEO
Project description:Mutations in CHD7, encoding ATP-dependent chromodomain-helicase-DNA-binding protein 7, in CHARGE syndrome leads to multiple congenital anomalies including growth retardation, craniofacial malformations and neurological dysfunction. Currently, mechanisms underlying the CNS phenotypes remain poorly understood. Here, we show that Chd7 is a direct transcriptional target of oligodendrogenesis-promoting factors Olig2 and Brg1 and required for proper timing of CNS myelination and remyelination. Genome-occupancy analyses coupled with transcriptome profiling reveal that Chd7 cooperates with Sox10 to target the enhancers of key myelinogenic genes, and identify novel Chd7 target. Examination of Chd7 and Sox10 genomewide occupancy in differentiating oligodendrocytes
2016-02-29 | E-GEOD-72725 | biostudies-arrayexpress
Project description:Mutations in CHD7, encoding ATP-dependent chromodomain-helicase-DNA-binding protein 7, in CHARGE syndrome leads to multiple congenital anomalies including growth retardation, craniofacial malformations and neurological dysfunction. Currently, mechanisms underlying the CNS phenotypes remain poorly understood. Here, we show that Chd7 is a direct transcriptional target of oligodendrogenesis-promoting factors Olig2 and Brg1 and required for proper timing of CNS myelination and remyelination. Genome-occupancy analyses coupled with transcriptome profiling reveal that Chd7 cooperates with Sox10 to target the enhancers of key myelinogenic genes, and identify novel Chd7 target. 4 RNA-Seq samples from P8 spinal cords of Ctrl and Chd7 cKO mice (duplicatess, Ctrl and cKO)
2016-02-29 | E-GEOD-72726 | biostudies-arrayexpress