Project description:CHD8, encoding Chromodomain helicase DNA binding protein 8, is a top autism spectrum disorders (ASDs) risk gene. To better understanding the molecular links between CHD8 functions and ASD, we have applied the CRISPR/Cas9 technology to knockout one copy of CHD8 in induced pluripotent stem cells (iPSCs) to mimic the loss of function status that would exist in the developing human embryo prior to neuronal differentiation. Transcriptome profiling (RNA-seq) in neural progenitors and early differentiating neurons revealed that CHD8 hemizygosity (CHD8+/-) affected the expression of several thousands of genes, enriched for functions of neural development, β-catenin/Wnt signaling, extracellular matrix, and skeletal system development. Moreover, CHD8 regulates multiple genes implicated in ASD, schizophrenia and genes associated with brain volume. iPSCs derived from a healthy subject were transduced with CRISPR/Cas9 vectors with single guide RNA sequences to target the N-terminal of CHD8 protein to generate truncated mutation seach of the two target sequences. Two clones, one with a 2-bp (KO1) and the other with a 10-bp (KO2) heterozygous deletion were found.The CHD8+/- iPSC lines were used to generate NPCs and early differentiating neurons for RNA-seq analysis, together with samples prepared from the parental clones, for a total of 8 samples (two biological replicates of wild-type (WT) and CHD8+/- at two neurodevelopmental stages).
Project description:Truncating mutations of CHD8, encoding a chromodomain helicase, and of many other genes with diverse functions, are strong-effect risk factors for autism spectrum disorder (ASD), suggesting multiple mechanisms of pathogenesis. We explored the transcriptional networks that CHD8 regulates in neural progenitor cells (NPCs) by reducing its expression and then integrating transcriptome sequencing (RNA-seq) with genome-wide CHD8 binding (ChIP-seq). Suppressing CHD8 to levels comparable with loss of a single allele caused altered expression of 1,756 genes, 64.9% of which were up-regulated. CHD8 showed widespread binding to chromatin, with 7,324 replicated sites that marked 5,658 genes. Integration of these data suggests that a limited array of direct regulatory effects of CHD8 produced a much larger network of secondary expression changes. Genes indirectly down-regulated (i.e., without CHD8 binding sites) reflect pathways involved in brain development, including synapse formation, neuron differentiation, cell adhesion, and axon guidance, whereas CHD8-bound genes are strongly associated with chromatin modification and transcriptional regulation. Genes associated with ASD were strongly enriched among indirectly down-regulated loci (pM-BM- =M-BM- 1.01x10-9) and CHD8-bound genes (p = 4.34x10-3), which align with previously identified co-expression modules during fetal development. We also find an intriguing enrichment of cancer related gene-sets among CHD8-bound genes (p < 1.9x10-11). In vivo suppression of chd8 in zebrafish produced macrocephaly comparable to that of humans with inactivating mutations. These data indicate that heterozygous disruption of CHD8 precipitates a network of gene expression changes involved in neurodevelopmental pathways in which many ASD-associated genes may converge on shared mechanisms of pathogenesis. ChIP-seq for CHD8 using three different antibodies, and the related protein CHD7, in human iPSC-derived NPCs treated with shRNA targeting GFP (which were used as control cells for an shRNA knockdown RNA-seq experiment that was part of the overall study)
Project description:ATAC-seq samples from 2 species and 2 cell types were generated to study cis-regulatory element evolution. Briefly, previously generated urinary stem cell derived iPS-cells (Homo sapiens) of 2 human individuals and fibroblast derived cynomolgus macaque iPSCs (Macaca fascicularis) of 2 individuals (Geuder et al. 2021) were differentiated to neural progenitor cells via dual-SMAD inhibition as three-dimensional aggregation culture (Chambers et al. 2009; Ohnuki et al. 2014). The NPC lines were cultured in NPC proliferation medium and passaged 2 - 4 times until they were dissociated and subjected to ATAC-seq together with the respective iPSC clones. ATAC-seq libraries were generated using the Omni-ATAC protocol (Corces et al. 2017) with minor modifications.
Project description:To understand the function of CHD8 in human ESC and neural differentiation, we generated the CHD8 knockout human ESCs and characterize the effect of loss-of-function of CHD8 on pluripotency maintenance and neuroectoderm determination by utilizing an efficient neuroectoderm differentiation protocol. Samples from hESC, CHD8KO_hESC and their derived-neural progenitor cells (hNPC) were collected for high-throughput sequencing with at least two replicates for each sample. Differentially expressed genes analysis showed loss of CHD8 affect the genes in ESC and NPC.
Project description:The chromatin remodeler CHD8 is among the most frequently mutated genes in autism spectrum disorder (ASD). CHD8 has a dosage-sensitive role in ASD but when and how it becomes critical to human social function is unclear. Here, we conducted genomic analyses of heterozygous and homozygous Chd8 mouse embryonic stem cells and differentiated neural progenitors. We identify dosage-sensitive CHD8 transcriptional targets, sites of regulated accessibility, and an unexpected cooperation with SOX transcription factors. Collectively, our findings reveal that CHD8 negatively regulates expression of neuronal genes to maintain pluripotency and also during differentiation. Thus, CHD8 is essential for both the maintenance of pluripotency and neural differentiation, providing mechanistic insight into its function with potential implications for ASD.
Project description:The chromatin remodeler CHD8 is among the most frequently mutated genes in autism spectrum disorder (ASD). CHD8 has a dosage-sensitive role in ASD but when and how it becomes critical to human social function is unclear. Here, we conducted genomic analyses of heterozygous and homozygous Chd8 mouse embryonic stem cells and differentiated neural progenitors. We identify dosage-sensitive CHD8 transcriptional targets, sites of regulated accessibility, and an unexpected cooperation with SOX transcription factors. Collectively, our findings reveal that CHD8 negatively regulates expression of neuronal genes to maintain pluripotency and also during differentiation. Thus, CHD8 is essential for both the maintenance of pluripotency and neural differentiation, providing mechanistic insight into its function with potential implications for ASD.
Project description:The chromatin remodeler CHD8 is among the most frequently mutated genes in autism spectrum disorder (ASD). CHD8 has a dosage-sensitive role in ASD but when and how it becomes critical to human social function is unclear. Here, we conducted genomic analyses of heterozygous and homozygous Chd8 mouse embryonic stem cells and differentiated neural progenitors. We identify dosage-sensitive CHD8 transcriptional targets, sites of regulated accessibility, and an unexpected cooperation with SOX transcription factors. Collectively, our findings reveal that CHD8 negatively regulates expression of neuronal genes to maintain pluripotency and also during differentiation. Thus, CHD8 is essential for both the maintenance of pluripotency and neural differentiation, providing mechanistic insight into its function with potential implications for ASD.