Genome-wide Definition of Promoter and Enhancer Usage During Neural Induction of Human Embryonic Stem Cells [gene expression profile]
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ABSTRACT: Genome-wide mapping of transcriptional regulatory elements are essential tools for the understanding of the molecular events orchestrating self-renewal, commitment and differentiation of stem cells. We combined high-throughput identification of nascent, Pol-II-transcribed RNAs by Cap Analysis of Gene Expression (CAGE-Seq) with genome-wide profiling of histones modifications by chromatin immunoprecipitation (ChIP-seq) to map active promoters and enhancers in a model of human neural commitment, represented by embryonic stem cells (ESCs) induced to differentiate into self-renewing neuroepithelial-like stem cells (NESC). We integrated CAGE-seq, ChIP-seq and gene expression profiles to discover shared or cell-specific regulatory elements, transcription start sites and transcripts associated to the transition from pluripotent to neural-restricted stem cell. Our analysis showed that >90% of the promoters are in common between the two cell types, while approximately half of the enhancers are cell-specific and account for most of the epigenetic changes occurring during neural induction, and most likely for the modulation of the promoters to generate cell-specific gene expression programs. Interestingly, the majority of the promoters activated or up-regulated during neural induction have a “bivalent” histone modification signature in ESCs, suggesting that developmentally-regulated promoters are already poised for transcription in ESCs, which are apparently pre-committed to neuroectodermal differentiation. Overall, our study provide a collection of differentially used enhancers, promoters, transcription starts sites, protein-coding and non-coding RNAs in human ESCs and ESC-derived NESCs, and a broad, genome-wide description of promoter and enhancer usage and gene expression programs occurring in the transition from a pluripotent to a neural-restricted cell fate. ESCs (H9 NIH code WA09, ISL1 Ds-Red) were kindly provided by the group of K.R. Chien. Neural differentiation was induced by the method of embryoid bodies following a published protocol [1]. Briefly, 4-days embryoid bodies were transferred to polyornithine-coated dishes and propagated in N2-supplemented DMEM/F12 (Invitrogen). Total RNA was extracted from 1-2x10^6 cells from three different cultures of ESCs and NESCs, transcribed into biotinylatedcRNA and hybridized onto GeneChip® HG-U133 Plus 2.0 Arrays (Affymetrix) according to the protocol supplied by the manufacturer (Affymetrix, Santa Clara, CA).
ORGANISM(S): Homo sapiens
SUBMITTER: Silvio Bicciato
PROVIDER: E-GEOD-61266 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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