Extensive changes in DNA methylation are associated with expression of mutant huntingtin
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Christopher Ng
PROVIDER: E-GEOD-43433 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:The earliest stages of HuntingtonM-bM-^@M-^Ys disease are marked by changes in gene expression that are caused in an indirect and poorly understood manner by polyglutamine expansions in the huntingtin protein (HTT). To explore the hypothesis DNA methylation may be altered in cells expressing mutated HTT, we use reduced-representation bisulfite sequencing (RRBS) to map sites of DNA methylation in cells carrying either wild-type or mutant HTT. We find that a large fraction of the genes that change in expression in the presence of mutant huntingtin demonstrate significant changes in DNA methylation. Regions with low CpG content, which have previously been shown to undergo methylation changes in response to neuronal activity, are disproportionately affected. Based on the sequence of regions that change in methylation, we identify AP-1 and SOX2 as transcriptional regulators associated with DNA methylation changes, and we confirm these hypotheses using genome-wide chromatin immunoprecipitation (ChIP-Seq). Our findings suggest new mechanisms for the effects of polyglutamine-expanded HTT. These results also raise important questions about the potential effects of changes in DNA methylation on neurogenesis and at later stages, cognitive decline in HuntingtonM-bM-^@M-^Ys patients. ChIP-seq for FRA-2, JUND, and SOX2 in STHdhQ7/Q7 and STHdhQ111/Q111 cells
2013-01-24 | E-GEOD-43429 | biostudies-arrayexpress
Project description:The earliest stages of Huntington’s disease are marked by changes in gene expression that are caused in an indirect and poorly understood manner by polyglutamine expansions in the huntingtin protein (HTT). To explore the hypothesis DNA methylation may be altered in cells expressing mutated HTT, we use reduced-representation bisulfite sequencing (RRBS) to map sites of DNA methylation in cells carrying either wild-type or mutant HTT. We find that a large fraction of the genes that change in expression in the presence of mutant huntingtin demonstrate significant changes in DNA methylation. Regions with low CpG content, which have previously been shown to undergo methylation changes in response to neuronal activity, are disproportionately affected. Based on the sequence of regions that change in methylation, we identify AP-1 and SOX2 as transcriptional regulators associated with DNA methylation changes, and we confirm these hypotheses using genome-wide chromatin immunoprecipitation (ChIP-Seq). Our findings suggest new mechanisms for the effects of polyglutamine-expanded HTT. These results also raise important questions about the potential effects of changes in DNA methylation on neurogenesis and at later stages, cognitive decline in Huntington’s patients. mRNA-seq in STHdhQ7/Q7 and STHdhQ111/Q111 cells
2013-01-24 | E-GEOD-43431 | biostudies-arrayexpress
Project description:The earliest stages of Huntington’s disease are marked by changes in gene expression that are caused in an indirect and poorly understood manner by polyglutamine expansions in the huntingtin protein (HTT). To explore the hypothesis DNA methylation may be altered in cells expressing mutated HTT, we use reduced-representation bisulfite sequencing (RRBS) to map sites of DNA methylation in cells carrying either wild-type or mutant HTT. We find that a large fraction of the genes that change in expression in the presence of mutant huntingtin demonstrate significant changes in DNA methylation. Regions with low CpG content, which have previously been shown to undergo methylation changes in response to neuronal activity, are disproportionately affected. Based on the sequence of regions that change in methylation, we identify AP-1 and SOX2 as transcriptional regulators associated with DNA methylation changes, and we confirm these hypotheses using genome-wide chromatin immunoprecipitation (ChIP-Seq). Our findings suggest new mechanisms for the effects of polyglutamine-expanded HTT. These results also raise important questions about the potential effects of changes in DNA methylation on neurogenesis and at later stages, cognitive decline in Huntington’s patients. MeDIP-seq in STHdhQ7/Q7 and STHdhQ111/Q111 cells
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Project description:Full pluripotency of induced pluripotent stem (iPS) cells has been determined as viable all-iPS mice can be generated through tetraploid complementation. Subsequently, activation of imprinted Dlk-Dio3 gene cluster has been suggested to correlate with the pluripotency of iPS cells1. However, evidence from recent studies has demonstrated that loss of imprinting at the Dlk-Dio3 locus did not correlate strictly with the reduced pluripotency of iPS cells. Therefore, it becomes indispensable to exploit other reliable molecular markers for evaluating the quality of iPS cells accurately. In the present study, we successfully utilize the sequential reprogramming approach and produce all-iPS mice to six generations using iPS cell lines derived from different cell lineages which contain the same proviral integration in the genome. By comparing the global gene expression and epigenetic modifications of both “tetra-on” and corresponding “tetra-off” iPS cell lines established from either mesenchymal or hematopoietic lineages through deep sequencing analysis of mRNA expression, small RNA profiling, histone modifications (H3K4m2, H3K4me3 and H3K27me3) and DNA methylation, very few differences are detected among all the iPS cell lines investigated. However, we find that two imprinted genes, disruption of which correlate with the reduced pluripotency of iPS cells. Therefore, our data not only provide the first demonstration that producing of all-iPS mice to six generations is feasible, but reveal that two imprinted regions can be served as pluripotency markers of iPS cells Examination of DNA methylation in 13 cell types
2013-12-06 | E-GEOD-36293 | biostudies-arrayexpress
Project description:Transcriptional dysregulation is an early feature of Huntington's disease (HD). We observed gene-specific changes in H3K4me3 at transcriptionally repressed promoters in R6/2 mouse and human HD brain. Genome-wide analysis showed a novel chromatin signature for this mark. Reducing the levels of the H3K4 demethylase SMCX/Jarid1c in primary neurons reversed down-regulation of key neuronal genes caused by mutant Huntingtin (Htt) expression. Finally, reduction of SMCX/Jarid1c in primary neurons from BACHD mice or the single Jarid1 in a Drosophila HD model was protective. Therefore, targeting this epigenetic signature may be an effective strategy to ameliorate the consequences of HD. ChIP-seq for H3K4me3 in wild type and R6/2 cortex and striatum at 8 and 12 weeks.
2013-07-18 | E-GEOD-48960 | biostudies-arrayexpress
Project description:Chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) is the method of choice to study function of transcription factors in cell fate determination. This technique faces two major obstacles when applied to developmental studies: the availability of ChIP grade antibodies and access to sufficient quantities of the cells of interest. We present a robust method for the genome-wide analysis of transcription factor binding during development in highly homogenous cells in defined developmental states. It combines efficient embryonic stem cell (ESC) differentiation protocols with an inducible system of tagged transcription factors to enable affinity based assays such as ChIP-seq during lineage specific development. To validate the system, we compared the activity and genomic binding of native and V5-tagged Olig2 in motor neuron progenitors and Flag-tagged and V5-tagged Hoxc9 in motor neurons. We find that tagging transcription factors and expressing them alongside their endogenous counterparts does not alter their function or genomic association. The technology presented here can be applied to known as well as novel DNA-binding proteins. In combination with a suitable ESC differentiation paradigm it can be applied to determine how lineage-specific transcriptional networks are established and regulated. The aim of this study is to validate a platform for analysis of transcription factor binding that combines directed differentiation of ES cells with an inducible system of tagged transcription factors. Here, we perform ChIP-seq analysis to compare binding profiles of Olig2 as found using a native antibody and anti-V5 against the epitope tag. We also compare the ChIP-seq profiles of Hoxc9 as found using two independent epitope tags (V5 and FLAG). In all, there are 6 Illumina sequence datasets in this submission, including one replicate for each of native Olig2, iOlig2-V5 and FLAG-iHoxc9, two replicates of iHoxc9-V5, and a pseudo-ChIP control using anti-V5 in a non-induced iOlig2 cell-line. The differentiation of ventral motor neurons is induced by treating embryonic stem cell cultures with retinoic acid and hedgehog.
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