ABSTRACT: RNA-seq analysis of ES cell populations with different functional potentials in serum/LIF and 2i/LIF, as well as analysis of the transcriptional effect of LIF in ground state (2i) culture conditions.
Project description:We report that ES cells cultured in ground state (2i and 2i/LIF) culture conditions are heterogeneous and show heterogeneus expression of extraembryonic markers. Using a highly sensitive reporter for the endoderm marker Hex we can sort Hex high and low populations from either serum/LIF or 2i/LIF and demonstrate that they have different functional properties. Here we explored the transcriptional basis of these functional differences and noted that Hex low (HV-) and Hex high (HV+) populations showed more distinct expression profiles in 2i/LIF than in serum/LIF. Additionally in 2i/LIF the HV+ population showed an upregulation of extraembryonic markers (such as trophoblast stem cell specific genes) and also imprinted genes compared to the HV- population, which is not observed when these populations are sorted from serum/LIF. We also analysed the transcriptional effect of LIF in 2i by analysing unsorted ES cells cultured in either 2i alone or 2i with LIF. We observed that the addition of LIF led to an upregulation of extraembryonic markers but did not effect the expression of pluripotency genes, other than Klf4. Additionally, the most significantly upregulated genes from 2i/LIF cultured ES cells compared to 2i cultured ES cells showed the greatest correlation to placental tissue when compared to the GNF tissue specific expression database. This analysis, alongside functional experiments, suggested that HV+ ES cells in 2i/LIF corresponded to an extraembryonically primed population of cells and that the addition of LIF supported this population. RNA-seq of sorted Hex low and high expressing ES cell populations cultured in serum/LIF or 2i/LIF as well as unsorted ES cells from 2i or 2i/LIF.
Project description:We report that ES cells cultured in ground state (2i and 2i/LIF) culture conditions are heterogeneous and show heterogeneus expression of extraembryonic markers. Using a highly sensitive reporter for the endoderm marker Hex we can sort Hex high and low populations from either serum/LIF or 2i/LIF and demonstrate that they have different functional properties. Here we explored the transcriptional basis of these functional differences and noted that Hex low (HV-) and Hex high (HV+) populations showed more distinct expression profiles in 2i/LIF than in serum/LIF. Additionally in 2i/LIF the HV+ population showed an upregulation of extraembryonic markers (such as trophoblast stem cell specific genes) and also imprinted genes compared to the HV- population, which is not observed when these populations are sorted from serum/LIF. We also analysed the transcriptional effect of LIF in 2i by analysing unsorted ES cells cultured in either 2i alone or 2i with LIF. We observed that the addition of LIF led to an upregulation of extraembryonic markers but did not effect the expression of pluripotency genes, other than Klf4. Additionally, the most significantly upregulated genes from 2i/LIF cultured ES cells compared to 2i cultured ES cells showed the greatest correlation to placental tissue when compared to the GNF tissue specific expression database. This analysis, alongside functional experiments, suggested that HV+ ES cells in 2i/LIF corresponded to an extraembryonically primed population of cells and that the addition of LIF supported this population.
Project description:We compare gene expression changes in mESCs culture in serum/LIF or 2i/LIF which favour the ground state pluripotency. Published RNASeq data where compared with newly generated data set in order to indentify transciptional signatures associated with pluripotency of mouse ES cells
Project description:The pluripotent ground state is defined as a basal state free of epigenetic restrictions, which influence lineage specification. While naive embryonic stem cells (ESCs) can be maintained in a hypomethylated state with open chromatin when grown using two small-molecule inhibitors (2i)/leukemia inhibitory factor (LIF), in contrast to serum/LIF-grown ESCs that resemble early post-implantation embryos, broader features of the ground-state pluripotent epigenome are not well understood. We identified epigenetic features of mouse ESCs cultured using 2i/LIF or serum/LIF by proteomic profiling of chromatin-associated complexes and histone modifications. Polycomb-repressive complex 2 (PRC2) and its product H3K27me3 are highly abundant in 2i/LIF ESCs, and H3K27me3 is distributed genome-wide in a CpG-dependent fashion. Consistently, PRC2-deficient ESCs showed increased DNA methylation at sites normally occupied by H3K27me3 and increased H4 acetylation. Inhibiting DNA methylation in PRC2-deficient ESCs did not affect their viability or transcriptome. Our findings suggest a unique H3K27me3 configuration protects naive ESCs from lineage priming, and they reveal widespread epigenetic crosstalk in ground-state pluripotency.
Project description:Mouse embryonic stem cells (mESCs) cultured in 2i (MEK and GSK3 kinase inhibitor)/LIF and serum/LIF that we called 2i-ESCs and serum-ESCs represent ground and confused pluripotent states, respectively. However, the transcription factors that regulate ground pluripotency through chromatin-associated characteristics are not yet fully understood. By mapping chromatin accessibility and transcription factor regulatory networks during the interconversion of 2i-ESCs and serum-ESCs, we have identified TEAD2 as highly enriched in 2i-specific peaks. While Tead2 knockout did not affect the pluripotency or differentiation ability of either 2i-ESCs or serum-ESCs, it did prevent the establishment of the 2i-specific state and the exit from the serum-specific state. TEAD2 binds to active regions in 2i-specific genes and activates their expression by regulating enhancer-promoter (EP) interactions during serum-to-2i transition. Remarkably, TEAD2-mediated EP interactions were independent of chromatin architecture proteins YY1 and CTCF, but instead appear to be facilitated by TEAD2 homodimer formation.
Project description:TKO mouse embryonic stem cells were cultured in serum/LIF and 2i/LIF in order to investigate the role of methylation in the transcriptional regulation of ground state cells (Clone: TKO 121, Tsumura et.al. 2006).
Project description:Hesx1+/+ and Hesx1-/- ES cells were cultured in 2i/LIF conditions for 5 passages, to induce a ground pluripotency state. Subsequently, inhibitors were removed to stimulate exit from ground pluripotency, and whole transcriptomics analysis was performed 24 hours after removal.
Project description:Mouse embryonic stem (ES) cells are locked into self-renewal by shielding from inductive cues. Release from this ground state in minimal conditions offers a system for delineating developmental progression from naive pluripotency. Here we examined the initial transition process. The ES cell population behaves asynchronously. We therefore exploited a short-half-life Rex1::GFP reporter to isolate cells either side of exit from naive status. Differentiation of Rex1-GFPd2 ES cells was initiated by withdrawing 2i (Kalkan et al., 2016). Undifferentiated 2i-cells and post-2i withdrawal differentiating populations (16h, 25h-Rex1-High, 25h-Rex1-Low) were subjected to proteomic analysis by Mass Spectrometry.
Project description:This study describes the DNA methylation profiling using whole-genome bisulfite sequencing of mouse ES cells, either derived and maintained in 2i serum-free NDiff medium, or in the presence of serum and LIF, or maintained and derived in the presence of serum and LIF and subsequently adapted to 2i serum-free NDiff medium, or maintained and derived in the presence of 2i and LIF and subsequently adapted to 2i serum. DNA methylation profiling using whole-genome bisulfite sequencing of 14 samples, 3 different lines (E14, XT67E1, Rex/GFP-2i) of pluripotent mouse ES cells as well during conversion from 2i to serum and vice versa.
Project description:This study describes the DNA methylation profiling using whole-genome bisulfite sequencing of mouse ES cells, either derived and maintained in 2i serum-free NDiff medium, or in the presence of serum and LIF, or maintained and derived in the presence of serum and LIF and subsequently adapted to 2i serum-free NDiff medium, or maintained and derived in the presence of 2i and LIF and subsequently adapted to 2i serum.
