Project description:Pluripotency can be maintained in the naïve state through manipulation of ERK and WNT signalling (2i), shielding embryonic stem cells (ESCs) from inductive cues. Alternatively, inhibiting CDK8/19 (CDK8/19i), a repressor of the Mediator co-activator complex, directly stimulates super-enhancer activity, and was recently shown to stabilize cells in a functional state that resembles naïve pluripotency. Naïve ESCs exhibit important epigenetic, transcriptional and metabolic features. However, our understanding on how these regulatory layers are inter-connected to promote the naive state is in progress. To fill this gap, here we used mass spectrometry to describe the dynamic molecular events (i.e. phosphoproteome, proteome and metabolome) executed by 2i and CDK8/19i, as they transition cell identity into naïve pluripotency. We observed rapid proteomic reprogramming, revealing widespread commonalities, and some important differences, between these two approaches, suggesting a largely over-lapping mechanism. CDK8/19i acts directly on the control of the transcriptional machinery, which elicits a rapid and direct activation of key identity genes including those that maintain the naïve program. Additional molecular changes in 2i are achieved by phosphorylation of critical downstream effectors that reinforce the naïve transcriptional circuitry while repressing factors from the more-differentiated formative and primed states. Comparing transcriptomic and proteomic changes, we found that post-transcriptional de-repression is a major feature of naïve pluripotency conferred by both 2i and CDK8/19i, and this may support the enhanced mitochondrial capacity of naive cells. Furthermore, at the level of metabolome, while 2i- and CDK8/19i-treated cells share similar aspects in one-carbon metabolism and beta-oxidation, in other regards they are divergent, a feature which may explain their differences in DNA methylation. These datasets provide a valuable resource for exploring the molecular mechanisms underlying pluripotency and cell identity transitions.
Project description:ChIP-seq to map the binding sites for CTCF and cohesin subunit Rad21 in the naive mES cells (46C cell line grown in the 2i/LIF condition) and in the neural stem cells (derived from the 46C ES cells using the mono-layer differentiation protocol, grown in the N2B27 medium these cells are Nestin+). The naive mES cells were grown in two different media (fetal bovine serum, FBS and 2i/LIF culture - naive pluripotency conditions) as detailed in the growth protocols.
Project description:<p>Naïve human embryonic stem cells (hESCs) that resemble the pre-implantation epiblasts are fueled by a combination of aerobic glycolysis and oxidative phosphorylation, but their mitochondrial regulators are poorly understood. Here we report that, proline dehydrogenase (PRODH), a mitochondria-localized proline metabolism enzyme, is dramatically upregulated in naïve hESCs compared to their primed counterparts. The upregulation of PRODH is induced by a reduction in c-Myc expression that is dependent on PD0325901, a MEK inhibitor routinely present in naive hESC culture media. PRODH knockdown in naive hESCs significantly promoted mitochondrial oxidative phosphorylation (mtOXPHOS) and reactive oxygen species (ROS) production that triggered autophagy, DNA damage, and apoptosis. Remarkably, MitoQ, a mitochondria-targeted antioxidant, effectively restored the pluripotency and proliferation of PRODH-knockdown naïve hESCs, indicating that PRODH maintains naïve pluripotency by preventing excessive ROS production. Concomitantly, PRODH knockdown significantly slowed down the proteolytic degradation of multiple key mitochondrial electron transport chain complex proteins. Thus, we revealed a crucial role of PRODH in limiting mtOXPHOS and ROS production, and thereby safeguarding naïve pluripotency of hESCs.</p><p><br></p><p><strong>Untargeted metabolomics</strong> - H9N PLKO.1 vs H9P PLKO.1 / H9P shPRODH vs H9P PLKO.1 / H9N shPRODH vs H9N PLKO.1 - is reported in the current study <a href='https://www.ebi.ac.uk/metabolights/MTBLS7840' rel='noopener noreferrer' target='_blank'><strong>MTBLS7840</strong></a>.</p><p><strong>Targeted metabolomics</strong> (amino acids and derivatives) - H9P (Primed) VS H9N (Naïve) - is reported in <a href='https://www.ebi.ac.uk/metabolights/MTBLS7832' rel='noopener noreferrer' target='_blank'><strong>MTBLS7832</strong></a>.</p>
Project description:<p>Naïve human embryonic stem cells (hESCs) that resemble the pre-implantation epiblasts are fueled by a combination of aerobic glycolysis and oxidative phosphorylation, but their mitochondrial regulators are poorly understood. Here we report that, proline dehydrogenase (PRODH), a mitochondria-localized proline metabolism enzyme, is dramatically upregulated in naïve hESCs compared to their primed counterparts. The upregulation of PRODH is induced by a reduction in c-Myc expression that is dependent on PD0325901, a MEK inhibitor routinely present in naive hESC culture media. PRODH knockdown in naive hESCs significantly promoted mitochondrial oxidative phosphorylation (mtOXPHOS) and reactive oxygen species (ROS) production that triggered autophagy, DNA damage, and apoptosis. Remarkably, MitoQ, a mitochondria-targeted antioxidant, effectively restored the pluripotency and proliferation of PRODH-knockdown naïve hESCs, indicating that PRODH maintains naïve pluripotency by preventing excessive ROS production. Concomitantly, PRODH knockdown significantly slowed down the proteolytic degradation of multiple key mitochondrial electron transport chain complex proteins. Thus, we revealed a crucial role of PRODH in limiting mtOXPHOS and ROS production, and thereby safeguarding naïve pluripotency of hESCs.</p><p><br></p><p><strong>Targeted metabolomics</strong> (amino acids and derivatives) - H9P (Primed) VS H9N (Naïve) - is reported in the current study <a href='https://www.ebi.ac.uk/metabolights/MTBLS7832' rel='noopener noreferrer' target='_blank'><strong>MTBLS7832</strong></a>.</p><p><strong>Untargeted metabolomics</strong> - H9N PLKO.1 vs H9P PLKO.1 / H9P shPRODH vs H9P PLKO.1 / H9N shPRODH vs H9N PLKO.1 - is reported in <a href='https://www.ebi.ac.uk/metabolights/MTBLS7840' rel='noopener noreferrer' target='_blank'><strong>MTBLS7840</strong></a>.</p>
Project description:Mouse embryonic stem cells (mESCs) are in naive pluripotency that represents the ground state of development, from which all cells in the mouse embryo are derived. In contrast, human embryonic stem cells (hESCs) are in a primed state of pluripotency with many different properties. Despite intense efforts to generate naive human pluripotent stem cells (hPSCs), it has not been possible to derive naive hPSCs without relying on transgene overexpression or chemicals. Here, we show that a transient treatment with Torin1, a selective inhibitor of mTOR, converted hPSCs from primed to naive pluripotency. The naive hPSCs were maintained in the same condition as mESCs in defined media with 2iLI (MEK inhibitor, GSK3b inhibitor, LIF and Insulin). Like mESCs, they exhibited high clonal efficiency, rapid cell proliferation, active mitochondrial respiration, X chromosome activation, DNA hypomethylation, and transcriptomes similar to those of human blastocysts than primed hESCs. Most importantly, the naive hPSCs significantly contributed to mouse embryos when transferred to mouse blastocysts. mTor inhibition induced nuclear translocation of TFE3, a critical transcription factor at the interplay of autophagy and pluripotency. TFE3 with mutated nuclear localization signal blocked the conversion from primed to naive pluripotency. It appears that by mimicking diapause at the cellular level, naive pluripotency in human can be readily attained from primed hPSCs, thus establishing the unified ground state of pluripotency in mammals.