Project description:Inhibitors of MEK1/2 and Gsk3b, known as '2i' culture conditions, enhance the derivation of embryonic stem cells (ESCs) and promote ground-state pluripotency in rodents 1,2. Here we show that the derivation of female mouse ESCs in the presence of 2i (2i-ESCs) results in a widespread loss of DNA methylation including a massive erasure of genomic imprints. Despite this global loss of DNA methylation, the early-passage 2i-ESCs efficiently differentiate into somatic cells and this process requires genome-wide de novo DNA methylation. However, the majority of imprinting control regions (ICRs) remain unmethylated in the 2i-ESC-derived differentiated cells. Consistently, 2i-ESCs exhibit impairment of autonomous embryonic and placental development by tetraploid embryo complementation and nuclear transplantation. We identified the derivation conditions of female ESCs that display 2i-ESC-like transcriptional signatures while preserving gamete-derived DNA methylation and autonomous developmental potential. Upon prolonged culture, however, female ESCs exhibit ICR demethylation, regardless of culture conditions. Our results provide insights into derivation of female ESCs reminiscent of ICM of preimplantation embryos. S-ESCs are ESCs established under serum-containing medium. 2i_S_ESCs are ESCs established in 2i-containing medium, followed by maintenance in serum-containing medium.
Project description:Preimplantation embryos undergo a transient wave of genome-wide demethylation with the exception of imprinted genes that are critical for fetal development. Here we show that the derivation of female mouse embryonic stem cells (ESCs) in the presence of inhibitors of MEK1/2 and Gsk3 (2i-ESCs), known as ‘2i’ or “ground-state” culture conditions, results in a widespread loss of DNA methylation including a massive erasure of genomic imprints. In this study, we analyzed global gene expression profile and global DNA methylation status in 2i-ESCs and 2i-ESCs derived differentiated cells. S-ESCs are ESCs established under serum-containing medium. 2i_S_ESCs are ESCs established in 2i-containing medium, followed by maintenance in serum-containing medium.
Project description:Derivation of naive state of mouse embryonic stem cells (mESCs) in LIF+serum (LS) culture condition is strain dependent, whereas derivation of ground state mESCs is readily possible from all strains tested so far in “2i” culture condition. ESCs can be derived from the post-implantation stage mouse embryos (EpiSCs), showing primed characteristics. In the present study, we characterized and compared the transcriptional profile of naïve, primed and ground state mESCs. Considering the importance of genetic background of mouse model for ESCs derivation in conventional culture conditions, all ESCs lines used in the study were derived from the same strain of mice. We found distinct transcriptional profiles between naive, primed and ground state mESCs. Primed state mESCs exhibit lower expression of pluripotency markers along with higher expression of lineage specific markers compared to naive and ground state mESCs. We also demonstrate that the differentiation propensity of ESCs to specific germ layer varies depending on the pluripotency state of ESCs.
Project description:Understanding mechanisms of epigenetic regulation in embryonic stem cells (ESCs) is of fundamental importance for stem cell and developmental biology. Here we identify Spic, a member of the ETS family of transcription factors, as a specific marker of ground state pluripotency. We show that Spic is rapidly induced in ESCs cultured with GSK3-, MEK-inhibitors and LIF (2iL), and in response to MEK/ERK inhibition. ChIP-seq analysis demonstrated that Spic binds to enhancer elements that are associated with pluripotency genes. Interaction proteomics and genomic profiling confirmed that SPIC interacts with NANOG and stabilizes its binding to chromatin in 2iL-ESCs. Additional gain of function and loss of function experiments revealed that Spic controls genes involved in one carbon (1C) metabolism, Bhmt, Bhmt2, and Dmgdh, and the flux of SAM-to-SAH in 2iL-ESCs. By maintaining low levels of SAM, Spic controls the level of H3K4me3 and H3R17me2 histone methylation in ground state ESCs. Our data highlight the role of uncharacterized axillary transcription factors that link cellular metabolism to epigenetic regulation in ground state pluripotency.
Project description:Understanding mechanisms of epigenetic regulation in embryonic stem cells (ESCs) is of fundamental importance for stem cell and developmental biology. Here we identify Spic, a member of the ETS family of transcription factors, as a specific marker of ground state pluripotency. We show that Spic is rapidly induced in ESCs cultured with GSK3-, MEK-inhibitors and LIF (2iL), and in response to MEK/ERK inhibition. ChIP-seq analysis demonstrated that Spic binds to enhancer elements that are associated with pluripotency genes. Interaction proteomics and genomic profiling confirmed that SPIC interacts with NANOG and stabilizes its binding to chromatin in 2iL-ESCs. Additional gain of function and loss of function experiments revealed that Spic controls genes involved in one carbon (1C) metabolism, Bhmt, Bhmt2, and Dmgdh, and the flux of SAM-to-SAH in 2iL-ESCs. By maintaining low levels of SAM, Spic controls the level of H3K4me3 and H3R17me2 histone methylation in ground state ESCs. Our data highlight the role of uncharacterized axillary transcription factors that link cellular metabolism to epigenetic regulation in ground state pluripotency.
Project description:We apply deep small-RNA sequencing technology for high-throughput profiling of microRNAs in ground state embryonic stem cells (ESCs). We provide global expression signatures of microRNAs in ESCs cultured under serum, 2i, and R2i conditions. We report that microRNAs are significantly differentially expressed when ESCs are cultured under different conditions, and that ground state pluripotency features a uniqure microRNA signature which is mainly encoded by microRNA-coding sequences within the developmentally important DLK1-Dio3 locus. Finally, we indicate that microRNA upregulated in ground state pluripotent cells (i.e. 2i/R2i) contribute to the maintenace of ground state pluripotency through stimulating self-renewal and inhibiting multi-lineague differentiation.
Project description:Here we report the derivation of human haploid ESCs from parthenogenetic haploid embryos. We used RNA-seq to compare the gene expression levels among human parthenogenetic haploid ESCs (hPGES), normal human ESCs (H9) and human forskin fibroblasts and identified that these cells express conventional ESCs pluripotent markers and most maternally imprinted genes were down-regulated.