ABSTRACT: Neuronal brain region-specific DNA methylation and chromatin accessibility are associated with neuropsychiatric trait heritability [ATAC-Seq]
Project description:Neuronal brain region-specific DNA methylation and chromatin accessibility are associated with neuropsychiatric trait heritability [RNA-Seq]
Project description:Neuronal brain region-specific DNA methylation and chromatin accessibility are associated with neuropsychiatric trait heritability [Bisulfite-Seq]
Project description:Brain region- and cell-specific transcriptome and epigenome molecular features are associated with heritability for neuropsychiatric traits. Here, we provide an atlas of chromatin accessibility and gene expression in neuronal and non-neuronal cells across 25 distinct regions across cortical and subcortical areas of the human brain from 6 neurotypical controls. We identified extensive gene expression and chromatin accessibility differences across brain regions. We further identified variation in alternative promoter-isoform usage and enhancer-promoter interactions across brain regions and found genes with distinct promoter-isoform usage are strongly enriched for neuropsychiatric risk variants. We identified brain region-specific chromatin co-accessibility and gene-coexpression modules that are robustly associated with genetic risk variants for neuropsychiatric disorders. Using an integrative approach, we identify a novel set of genes that is enriched for neuropsychiatric disorders risk variants but is independent of cell-type specific gene expression and annotated pathways. Our results provide a valuable multi-brain region molecular regulation resource and suggest a unique contribution of epigenetic modifications from the subcortical areas to neuropsychiatric disorders.
Project description:Brain region- and cell-specific transcriptome and epigenome molecular features are associated with heritability for neuropsychiatric traits. Here, we provide an atlas of chromatin accessibility and gene expression in neuronal and non-neuronal cells across 25 distinct regions across cortical and subcortical areas of the human brain from 6 neurotypical controls. We identified extensive gene expression and chromatin accessibility differences across brain regions. We further identified variation in alternative promoter-isoform usage and enhancer-promoter interactions across brain regions and found genes with distinct promoter-isoform usage are strongly enriched for neuropsychiatric risk variants. We identified brain region-specific chromatin co-accessibility and gene-coexpression modules that are robustly associated with genetic risk variants for neuropsychiatric disorders. Using an integrative approach, we identify a novel set of genes that is enriched for neuropsychiatric disorders risk variants but is independent of cell-type specific gene expression and annotated pathways. Our results provide a valuable multi-brain region molecular regulation resource and suggest a unique contribution of epigenetic modifications from the subcortical areas to neuropsychiatric disorders.
Project description:The majority of common genetic risk variants associated with neuropsychiatric disease are non-coding and are thought to exert their effects by disrupting the function of cis regulatory elements (CREs), including promoters and enhancers. Within each cell, chromatin is arranged in specific patterns to expose the repertoire of CREs required for optimal spatiotemporal regulation of gene expression. To further our understanding of the complex mechanisms that modulate transcription in the brain, we utilized frozen postmortem samples to generate the largest human brain and cell type-specific open chromatin dataset to date. Using the Assay for Transposase Accessible Chromatin followed by sequencing (ATAC-seq), we created maps of chromatin accessibility in 2 cell types (neurons and non-neurons) across 14 distinct brain regions of 5 individuals. Chromatin structure varies markedly by cell type, with neuronal chromatin displaying higher regional variability than that of non-neurons. Among our findings is an open chromatin region (OCR) specific to neurons of the striatum. When placed in the mouse, a human sequence derived from this OCR recapitulates the cell-type and regional expression pattern predicted by our ATAC-seq experiments. Furthermore, differentially accessible chromatin overlaps with the genetic architecture of neuropsychiatric traits and identifies differences in molecular pathways and biological functions. By leveraging transcription factor binding analysis, we identify protein coding and long noncoding RNAs (lncRNAs) with cell-type and brain region specificity. Our data provides a valuable resource to the research community and we provide this human brain chromatin accessibility atlas as an online database “Brain Open Chromatin Atlas (BOCA)” to facilitate interpretation.
Project description:The epigenome of human brain cells encompasses key information in understanding brain function in both healthy and diseased states. To further explore this, we used ATAC-seq to profile chromatin structure in four distinct populations of cells (glutamatergic neurons, GABAergic neurons, oligodendrocytes, and microglia/astrocytes), from three different regions of the brain. Chromatin accessibility was found to vary vastly by cell type and, more moderately, by brain region, with glutamatergic neurons showing the greatest regional variability. Transcription factor footprinting pointed to cell-specific transcriptional regulators and inferred cell-specific regulation of protein coding genes, long intergenic noncoding RNAs, and microRNAs. In vivo transgenic mouse experiments validated the cell type specificity of a number of human-derived regulatory sequences. Open chromatin regions in glutamatergic neurons were enriched for neuropsychiatric risk variants, particularly those associated with schizophrenia. Combining differential chromatin accessibility analysis using ATAC-seq data from bulk tissue increased our statistical power to confirm glutamatergic neurons as the cell type most affected in schizophrenia. Jointly, these findings illustrate the utility of studying the cell type specific epigenome in complex tissues such as the human brain and implicate an association among chromatin accessibility in glutamatergic neurons and genetic risk for schizophrenia.
Project description:A comparative atlas of single-cell chromatin accessibility in the human brainRecent advances in single-cell transcriptomics have illuminated the diverse neuronal and glial cell types within the human brain. However, the regulatory programs governing cell identity and function remain unclear. Using a single-nucleus assay for transposase-accessible chromatin using sequencing (ATAC-seq), we explored open chromatin landscapes across 1.1 million cells in 42 brain regions from three adults. Integrating this data unveiled 107 distinct cell types and their specific utilization of 544,735 candidate cis-regulatory DNA elements (cCREs) in the human genome. Nearly a third of the cCREs demonstrated conservation and chromatin accessibility in the mouse brain cells. We reveal strong links between specific brain cell types and neuropsychiatric disorders including schizophrenia, bipolar disorder, Alzheimer’s disease (AD), and major depression, and have developed deep learning models to predict the regulatory roles of noncoding risk variants in these disorders.
Project description:The Assay for Transposase Accessible Chromatin by sequencing (ATAC-seq) is becoming increasing popular in the neuroscience field where chromatin regulation is thought to be involved in neurodevelopment, activity-dependent gene regulation, hormonal and environmental responses, and pathophysiology of neuropsychiatric disorders. The advantages of using this assay include a small amount of material needed, relatively simple and fast protocol, and the ability to capture a range of gene regulatory elements with a single assay. However, with increasing interest in chromatin research, it is an imperative to have feasible, reliable assays that are compatible with a range of neuroscience study designs in both animals and humans. Here we tested three different protocols for neuronal chromatin accessibility analysis, including a varying brain tissue freezing method followed by fluorescent-activated nuclei sorting (FANS) and the ATAC-seq analysis. Our study shows that the cryopreservation method impacts the number of open chromatin regions that can be identified from frozen brain tissue using the cell-type specific ATAC-seq assay. However, we show that all three protocols generate consistent and robust data and enable the identification of functional regulatory elements, promoters and enhancers, in neuronal cells. Our study also implies that the broad biological interpretation of chromatin accessibility data is not significantly affected by the freezing condition. In comparison to the mouse brain analysis, we reveal the additional challenges of doing chromatin analysis on postmortem human brain tissue. However, we also show that these studies are revealing important cell type-specific information about gene regulation in the human brain. Overall, the ATAC-seq coupled with FANS is a powerful method to capture cell-type specific chromatin accessibility information in the mouse and human brain. Our study provides alternative brain preservation methods that generate high quality ATAC-seq data while fitting in different study designs, and further encourages the use of this method to uncover the role of epigenetic (dys)regulation in healthy and malfunctioning brain.
Project description:The Assay for Transposase Accessible Chromatin by sequencing (ATAC-seq) is becoming increasing popular in the neuroscience field where chromatin regulation is thought to be involved in neurodevelopment, activity-dependent gene regulation, hormonal and environmental responses, and pathophysiology of neuropsychiatric disorders. The advantages of using this assay include a small amount of material needed, relatively simple and fast protocol, and the ability to capture a range of gene regulatory elements with a single assay. However, with increasing interest in chromatin research, it is an imperative to have feasible, reliable assays that are compatible with a range of neuroscience study designs in both animals and humans. Here we tested three different protocols for neuronal chromatin accessibility analysis, including a varying brain tissue freezing method followed by fluorescent-activated nuclei sorting (FANS) and the ATAC-seq analysis. Our study shows that the cryopreservation method impacts the number of open chromatin regions that can be identified from frozen brain tissue using the cell-type specific ATAC-seq assay. However, we show that all three protocols generate consistent and robust data and enable the identification of functional regulatory elements, promoters and enhancers, in neuronal cells. Our study also implies that the broad biological interpretation of chromatin accessibility data is not significantly affected by the freezing condition. In comparison to the mouse brain analysis, we reveal the additional challenges of doing chromatin analysis on postmortem human brain tissue. However, we also show that these studies are revealing important cell type-specific information about gene regulation in the human brain. Overall, the ATAC-seq coupled with FANS is a powerful method to capture cell-type specific chromatin accessibility information in the mouse and human brain. Our study provides alternative brain preservation methods that generate high quality ATAC-seq data while fitting in different study designs, and further encourages the use of this method to uncover the role of epigenetic (dys)regulation in healthy and malfunctioning brain.