Pontin functions as an essential coactivator for Oct4 target genes and lincRNAs in embryonic stem cells.
ABSTRACT: The actions of transcription factors, chromatin modifiers, and noncoding RNAs are crucial for the programming of cellular states. Although chromatin remodeling factors regulate the functional status of cells including pluripotency and differentiation, how they cross-talk with embryonic stem (ES) cell-specific transcription factors and noncoding RNAs to coordinate networks controlling of ES cell identity remain unknown. Here, we find that Pontin chromatin remodeling factor plays an essential role as a coactivator for Oct4 target genes and large intergenic noncoding RNAs (lincRNAs) in ES cells. mRNA- and ChIP-sequencing analyses reveal that Pontin and Oct4 share a substantial set of target genes involved in maintenance of ES cells. Intriguingly, Oct4-dependent coactivator function of Pontin extends to transcription of lincRNAs that are mainly involved in repression of differentiation in ES cells. Together, our findings demonstrate newly identified Oct4-Pontin-lincRNA module plays critical roles in the ES cell circuitry to orchestrate cell fate determination program. For mRNA-sequencing, we obtained mRNAs from 1) Pontinf/f; CreER ES cells at 0, 3, or 4 days post-treatment with 4-hydroxy tamoxifen (OHT) for Pontin-depleted ES cells without biological replicates (n=1), 2) ZHBTc4 ES cells at 2 days post-treatment with tetracycline (Tc) for Oct4-depleted ES cells (n=1), and 3) ZHBTc4 ES cells infected by pLKO control or pLKO-shlinc1253 lentivirus at 4 days post infection for knockdown of linc1253 (n=2). For ChIP-sequencing, chromatin extracts containing DNA fragments with an average size of 400bp were immmunoprecipitated by using antibodies against GFP (control) or Pontin. Eluted ChIP DNA (n=1).
Project description:Gene expression profiles of ZHBTc4 ES cells expressing EGFP, Oct4-EGFP, Nr5a2-EGFP under CAG promoter. Monoclonal cell lines selected by Puromycin were used for analysis. Each of the cell lines was cultured in doxycycline containing media for endogenous Oct4 knock-down. Pupose of this experiment is to investigate the possibility that forced expression of Nr5a2 can replace Oct4 function in the self-renewal of ES cells. Monoclonal ZHBTc4 ES cells expressing EGFP vs Nr5a2-EGFP, Oct4-EGFP vs Nr5a2-EGFP, no replication
Project description:In order to investigate the cooperative roles of Pontin and Oct4 for self-renewal and pluripotency in mouse ES cells, we performed mRNA-sequencing analysis from mRNAs isolated from Pontin- and Oct4-depleted ES cells. This analysis provides insight into molecular mechanisms for maintaining ES cell identity. mRNA expression profiles of Pontinf/f; CreER ES cells at 0, 3, or 4 days post-treatment with OHT (wild type and Pontin-depleted ES cells) and ZHBTc4 ES cells at 2 days post-treatment with tetracycline (Oct4-depleted ESE cells) were examined by Illumina Hiseq2000.
Project description:The master transcription factors Oct4, Sox2 and Nanog bind enhancer elements and recruit the Mediator co-activator to activate much of the gene expression program of embryonic stem cells (ESCs). We report here that these ESC master transcription factors and Mediator form “super-enhancers” at most genes that are known to control the pluripotent state, including those encoding the master transcription factors themselves. These super-enhancers consist of extraordinarily large genomic domains occupied by exceptional amounts of Oct4 and Mediator. Super-enhancers stimulate considerably higher transcription than typical enhancers in reporter vectors. ESC differentiation causes preferential loss of expression of super-enhancer -associated genes. Super-enhancers are also found at key cell identity genes in differentiated cells. These results implicate super-enhancers in the control of mammalian cell identity and differentiation and suggest that these elements might generally be used to identify genes that control cell-type specific gene expression programs in many mammalian cells. ChIP-Seq and RNA-seq of Med1 in ZHBTc4 ES during treatment with doxycycline. ChIP-Seq data of Med1 in 38B9 pro-B cells.
Project description:To understand the mechanism underlying the versatility in transcriptional regulation by Sox2, we compared genome-wide binding sites of Sox2 in embryonic stem (ES) cells and trophoblast stem (TS) cells by chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq). A tetracycline-inducible Oct3/4 knockout ES cell line ZHBTc4 was treated with Tet for 4 days in the presence of FGF4 and mouse embryonic fibroblasts (MEFs).
Project description:Mouse embryonic stem (ES) cells are isolated from the inner cell mass of blastocysts, and can be preserved in vitro in a naive inner-cell-mass-like configuration by providing exogenous stimulation with leukaemia inhibitory factor (LIF) and small molecule inhibition of ERK1/ERK2 and GSK3b signalling (termed 2i/LIF conditions). Hallmarks of naive pluripotency include driving Oct4 (also known as Pou5f1) transcription by its distal enhancer, retaining a pre-inactivation X chromosome state, global reduction in DNA methylation and in H3K27me3 repressive chromatin mark deposition on developmental regulatory gene promoters.Upon withdrawal of 2i/LIF, naïve mouse ES cells can drift towards a primed pluripotent state resembling that of the post-implantation epiblast. Although human ES cells share several molecular features with naive mouse ES cells, they also share a variety of epigenetic properties with primed murine epiblast stem cells (EpiSCs). These include use of the proximal enhancer element to maintain OCT4 expression, pronounced tendency for X chromosome inactivation in most female human ES cells, increase in DNA methylation and prominent deposition of H3K27me3 and bivalency acquisition on lineage regulatory genes. The feasibility for establishing human ground state naive pluripotency in vitro with equivalent molecular and functional features to those characterized in rodent ES cells remains to be defined. Here we establish defined conditions that facilitate the derivation of genetically unmodified human naive pluripotent stem cells from already established primed human ES cells, from somatic cells through induced pluripotent stem (iPS) cell reprogramming or directly from blastocysts. The novel naive pluripotent cells validated herein retain molecular characteristics and functional properties that are highly similar to mouse naive ES cells, and distinct from conventional primed human pluripotent cells. This includes competence in the generation of cross-species chimaeric embryos that underwent organogenesis following microinjection of human naive iPS cells into mouse morulas. Collectively, our findings establish new avenues for regenerative medicine, patient-specific iPS cell disease modelling and the study of early human development in vitro and in vivo. Four chromatin marks H3K4me1, H3K4me3, H3K27ac and H3K27me3 were measured from 3 cell lines: C1 and WIBR3 (naïve and conventional/primed stem cells), and BGO1 (only naïve stem cells).
Project description:To understand the mechanism underlying the transcriptional regulation by Sox2, we analyzed genome-wide binding sites of Sox2, Tfap2c, and Cdx2 in trophoblast stem (TS) cells by chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq). ZHBTc4- and embryo-derived TS cell lines were maintained in the presence of FGF4 and mouse embryonic fibroblasts (MEFs).
Project description:Analysis of wild type, PKm1 KI, 2TS22c and, ZHBTc4 ES cell lines and Embryoid Body from wild type ES cells. Overall design: Each ES cells were cultured the medium containing LIF and EB were differentiated into three germ layer using embryoid body formation culture.
Project description:Pluripotency of embryonic stem (ES) cells is controlled in part by chromatin-modifying factors that regulate histone H3 lysine 4 (H3K4) methylation. However, it remains unclear how H3K4 demethylation contributes to ES cell function. Here, we show that KDM5B, which demethylates lysine 4 of histone H3, co-localizes with H3K4me3 near promoters and enhancers of active genes in ES cells; its depletion leads to spreading of H3K4 methylation into gene bodies and enhancer shores, indicating that KDM5B functions to focus H3K4 methylation at promoters and enhancers. Spreading of H3K4 methylation to gene bodies and enhancer shores is linked to defects in gene expression programs and enhancer activity, respectively, during self-renewal and differentiation of KDM5B-depleted ES cells. KDM5B critically regulates H3K4 methylation at bivalent genes during differentiation in the absence of LIF or Oct4. We also show that KDM5B and LSD1, another H3K4 demethylase, co-regulate H3K4 methylation at active promoters but they retain distinct roles in demethylating gene body regions and bivalent genes. Our results provide global and functional insight into the role of KDM5B in regulating H3K4 methylation marks near promoters, gene bodies, and enhancers in ES cells and during differentiation. RNA-Seq of murine shLuc and shKdm5b ES cells differentiated for 72h in the absence of LIF.
Project description:MicroRNAs (miRNAs) are crucial for normal embryonic stem (ES) cell self-renewal and cellular differentiation, but how miRNA gene expression is controlled by the key transcriptional regulators of ES cells has not been established. We describe here a new map of the transcriptional regulatory circuitry of ES cells that incorporates both protein-coding and miRNA genes, and which is based on high-resolution ChIP-seq data, systematic identification of miRNA promoters, and quantitative sequencing of short transcripts in multiple cell types. We find that the key ES cell transcription factors are associated with promoters for most miRNAs that are preferentially expressed in ES cells and with promoters for a set of silent miRNA genes. This silent set of miRNA genes is co-occupied by Polycomb Group proteins in ES cells and expressed in a tissue-specific fashion in differentiated cells. These data reveal how key ES cell transcription factors promote the miRNA expression program that contributes to self-renewal and cellular differentiation, and integrate miRNAs and their targets into an expanded model of the regulatory circuitry controlling ES cell identity. Keywords: ChIP-seq analysis of ES cell transcriptional regulators and chromatin modifications. Cell-type comparison of short RNA transcritome. Analysis of changes in short RNA transcritome upon Oct4 ablation. ChIP-seq in murine embryonic stem cells for Oct4, Sox2 (2 runs), Nanog (2 runs), Tcf3 (2 runs), Suz12 (2 runs), H3K4me3 (4 runs), H3k79me2 (2 runs), H3k36me3 (2 runs) and whole cell extract input DNA (WCE, 2 runs). Short transcript sequencing from murine embryonic stem cells (mES, v6.5), mouse embryonic fibroblasts (MEF), murine neural precursor cells (NPC), and ZHBT-c4 cells (from Austin Smith) untreated (0h), with 12 hours of doxycyclin treatment (12h), and with 24 hours of doxycyclin treatment (24h).