Project description:Differences in DNA methylation between human neuronal and glial cells are concentrated in enhancers and non-CpG sites [methylation array]
Project description:Differences in DNA Methylation between Human Neuronal and Glial Cells are Concentrated in Enhancers and non-CpG Sites [Enhanced Reduced Representation Bisulfite Sequencing data]
Project description:We applied Illumina Human Methylation450K array to perform a genomic-scale single-site resolution DNA methylation analysis in neuronal and nonneuronal (primarily glial) nuclei separated from the orbitofrontal cortex of postmortem human brain. The findings were validated using enhanced reduced representation bisulfite sequencing. We identified thousands of sites differentially methylated (DM) between neuronal and nonneuronal cells. The DM sites were depleted within CpG island–containing promoters but enriched in predicted enhancers. Classification of the DM sites into those undermethylated in neurons (neuronal type) and those undermethylated in nonneuronal cells (glial type), combined with findings of others that methylation within control elements typically negatively correlates with gene expression, yielded large sets of predicted neuron-specific and non– neuron-specific genes. These sets of predicted genes were in excellent agreement with the available direct measurements of gene expression in human and mouse. We also found a distinct set of DNA methylation patterns that were unique for neuronal cells. In particular, neuronal-type differential methylation was overrepresented in CpG island shores, enriched within gene bodies but not in intergenic regions, and preferentially harbored binding motifs for a distinct set of transcription factors, including neuron-specific activity-dependent factors. Finally, non-CpG methylation was substantially more prevalent in neurons than in nonneuronal cells. Genomic DNA was isolated from FACS-sorted human brain neuronal and nonneuronal nuclei. DNA was bisulfite converted and hybridised to the Illumina Infinium 450K Human Methylation Beadchip array. Six subjects in two technical replicate expriments were analyzed.
Project description:We applied Illumina Human Methylation450K array to perform a genomic-scale single-site resolution DNA methylation analysis in neuronal and nonneuronal (primarily glial) nuclei separated from the orbitofrontal cortex of postmortem human brain. The findings were validated using enhanced reduced representation bisulfite sequencing. We identified thousands of sites differentially methylated (DM) between neuronal and nonneuronal cells. The DM sites were depleted within CpG islandM-bM-^@M-^Scontaining promoters but enriched in predicted enhancers. Classification of the DM sites into those undermethylated in neurons (neuronal type) and those undermethylated in nonneuronal cells (glial type), combined with findings of others that methylation within control elements typically negatively correlates with gene expression, yielded large sets of predicted neuron-specific and nonneuron-specific genes. These sets of predicted genes were in excellent agreement with the available direct measurements of gene expression in human and mouse. We also found a distinct set of DNA methylation patterns that were unique for neuronal cells. In particular, neuronal-type differential methylation was overrepresented in CpG island shores, enriched within gene bodies but not in intergenic regions, and preferentially harbored binding motifs for a distinct set of transcription factors, including neuron-specific activity-dependent factors. Finally, non-CpG methylation was substantially more prevalent in neurons than in nonneuronal cells. Extended Reduced Representation Bisulfite Sequencing (ERRBS) was performed on genomic DNA to validate the Infinium HM450K DNA methylation data (Kozlenkov et. al., 2013, Nucleic Acids Research, accepted for publication).
Project description:We applied Illumina Human Methylation450K array to perform a genomic-scale single-site resolution DNA methylation analysis in neuronal and nonneuronal (primarily glial) nuclei separated from the orbitofrontal cortex of postmortem human brain. The findings were validated using enhanced reduced representation bisulfite sequencing. We identified thousands of sites differentially methylated (DM) between neuronal and nonneuronal cells. The DM sites were depleted within CpG island–containing promoters but enriched in predicted enhancers. Classification of the DM sites into those undermethylated in neurons (neuronal type) and those undermethylated in nonneuronal cells (glial type), combined with findings of others that methylation within control elements typically negatively correlates with gene expression, yielded large sets of predicted neuron-specific and non– neuron-specific genes. These sets of predicted genes were in excellent agreement with the available direct measurements of gene expression in human and mouse. We also found a distinct set of DNA methylation patterns that were unique for neuronal cells. In particular, neuronal-type differential methylation was overrepresented in CpG island shores, enriched within gene bodies but not in intergenic regions, and preferentially harbored binding motifs for a distinct set of transcription factors, including neuron-specific activity-dependent factors. Finally, non-CpG methylation was substantially more prevalent in neurons than in nonneuronal cells.
Project description:We applied Illumina Human Methylation450K array to perform a genomic-scale single-site resolution DNA methylation analysis in neuronal and nonneuronal (primarily glial) nuclei separated from the orbitofrontal cortex of postmortem human brain. The findings were validated using enhanced reduced representation bisulfite sequencing. We identified thousands of sites differentially methylated (DM) between neuronal and nonneuronal cells. The DM sites were depleted within CpG island–containing promoters but enriched in predicted enhancers. Classification of the DM sites into those undermethylated in neurons (neuronal type) and those undermethylated in nonneuronal cells (glial type), combined with findings of others that methylation within control elements typically negatively correlates with gene expression, yielded large sets of predicted neuron-specific and nonneuron-specific genes. These sets of predicted genes were in excellent agreement with the available direct measurements of gene expression in human and mouse. We also found a distinct set of DNA methylation patterns that were unique for neuronal cells. In particular, neuronal-type differential methylation was overrepresented in CpG island shores, enriched within gene bodies but not in intergenic regions, and preferentially harbored binding motifs for a distinct set of transcription factors, including neuron-specific activity-dependent factors. Finally, non-CpG methylation was substantially more prevalent in neurons than in nonneuronal cells.
Project description:Direct neuronal reprogramming is a promising approach to regenerate neurons from local glial cells. However, mechanisms of epigenome remodeling and co-factors facilitating this process are unclear. Here, we combine single-cell multiomics with genome-wide profiling of 3D nuclear architecture and DNA methylation in mouse astrocyte-to-neuron reprogramming mediated by Neurogenin2 (Ngn2) and its phosphorylation-resistant form (PmutNgn2), respectively. We show that Ngn2 drives multilayered chromatin remodelling at dynamic enhancer-gene interaction sites. PmutNgn2 leads to higher reprogramming efficiency and enhances epigenetic remodeling associated with neuronal maturation. However, the differences in binding sites or downstream gene activation cannot fully explain this effect. Instead, we identify Yy1, a transcriptional co-factor, recruited by direct interaction with Ngn2 to its target sites. Upon deletion of Yy1, activation of neuronal enhancers, genes, and ultimately reprogramming are impaired without affecting Ngn2 binding. Thus, our work highlights the key role of interactors of proneural factors in direct neuronal reprogramming.
Project description:DNA methylation changes in neuroblastoma, a clinically-heterogeneous pediatric tumor, have been described essentially in promoter regions. We analyzed the DNA methylome of neuroblastoma using high-density microarrays and observed differential methylation not only in promoters but also in intragenic and intergenic regions at both CpG and non-CpG sites. These epigenetic changes showed a non-random distribution relative functional chromatin domains, and targeted development and cancer-related genes, relevant for neuroblastoma pathogenesis. CCND1, a gene overexpressed in neuroblastoma, showed hypomethylation of gene-body and upstream regulatory regions. Furthermore, tumors with diverse clinical-risk showed clear differences affecting CpG and, remarkably, non-CpG sites. Non-CpG methylation was present in clinically-favorable tumors and affected genes such as ALK, where non-CpG methylation correlated with low gene expression. Finally, we identified CpG and non-CpG methylation signatures which correlated with patient’s age at time-points relevant for neuroblastoma clinical behavior, and targeted genes related to neural development and neural crest regulatory network We report on the first DNA methylomes of neuroblastoma tumors using high-density microarrays. DNA methylation changes in this pediatric tumor affected both CpG and non-CpG sites associated with developmental and cancer-related genes such as CCND1 and ALK. Our study also provides new insights into the molecular basis of the heterogeneous clinical behavior of neuroblastoma.
Project description:DNA methylation changes in neuroblastoma, a clinically-heterogeneous pediatric tumor, have been described essentially in promoter regions. We analyzed the DNA methylome of neuroblastoma using high-density microarrays and observed differential methylation not only in promoters but also in intragenic and intergenic regions at both CpG and non-CpG sites. These epigenetic changes showed a non-random distribution relative functional chromatin domains, and targeted development and cancer-related genes, relevant for neuroblastoma pathogenesis. CCND1, a gene overexpressed in neuroblastoma, showed hypomethylation of gene-body and upstream regulatory regions. Furthermore, tumors with diverse clinical-risk showed clear differences affecting CpG and, remarkably, non-CpG sites. Non-CpG methylation was present in clinically-favorable tumors and affected genes such as ALK, where non-CpG methylation correlated with low gene expression. Finally, we identified CpG and non-CpG methylation signatures which correlated with patient’s age at time-points relevant for neuroblastoma clinical behavior, and targeted genes related to neural development and neural crest regulatory network We report on the first DNA methylomes of neuroblastoma tumors using high-density microarrays. DNA methylation changes in this pediatric tumor affected both CpG and non-CpG sites associated with developmental and cancer-related genes such as CCND1 and ALK. Our study also provides new insights into the molecular basis of the heterogeneous clinical behavior of neuroblastoma.
Project description:Analysis of genomic methylation differences between day workers and shift workers. We hypothesized that there would be differences in methylation patterns between day workers and shift workers, and that some of these differences may explain the association between long-term shift work and breast cancer. The array provides methylation data on more than 27,000 CpG sites spread across the genome.