Project description:Reversion from primed to naïve pluripotent status has been achieved by various signaling manipulation, but it is still unclear what signaling is the actual driving force to get over the hurdle from primed to naïve pluripotency. We previously reported that activation of AMP kinase (AMPK) contributed to maintenance of naïve pluripotency. Here, we further show that AMPK activators, AICAR, A769662 or metformin, can induce the reversion of primed mouse epiblast stem cells (mEpiSCs) to naïve pluripotent state. Primed mEpiSCs in our naïve cell culture condition with leukemia inhibitory factor (LIF) and 2 kinase inhibitors (2i) (2iL) never gave rise to naïve state cells. Addition of AICAR alone even in the absence of 2iL or either of AMPK inhibitors with LIF induced appearance of naïve-like cells from primed mEpiSCs. Through maintenance and passages of these cells in 2iL condition, clear naïve-like morphology colonies were purely obtained. They showed core naïve protein expression, and global naïve gene expression profiles. These cells contributed to chimeric mice including germline transmission. Inhibition of p38 signaling abolished the AMPK-elicited reversion and forced activation of p38 in primed mEpiSCs partially reproduced the naïve cell induction, suggesting that p38 is one of the critical downstream in AMPK activation. AMPK pathway should be a novel critical driving force in reversion of primed to naïve pluripotency.
Project description:Reversion from primed to naïve pluripotent status has been achieved by various signaling manipulation, but it is still unclear what signaling is the actual driving force to get over the hurdle from primed to naïve pluripotency. We previously reported that activation of AMP kinase (AMPK) contributed to maintenance of naïve pluripotency. Here, we further show that AMPK activators, AICAR, A769662 or metformin, can induce the reversion of primed mouse epiblast stem cells (mEpiSCs) to naïve pluripotent state. Primed mEpiSCs in our naïve cell culture condition with leukemia inhibitory factor (LIF) and 2 kinase inhibitors (2i) (2iL) never gave rise to naïve state cells. Addition of AICAR alone even in the absence of 2iL or either of AMPK inhibitors with LIF induced appearance of naïve-like cells from primed mEpiSCs. Through maintenance and passages of these cells in 2iL condition, clear naïve-like morphology colonies were purely obtained. They showed core naïve protein expression, and global naïve gene expression profiles. These cells contributed to chimeric mice including germline transmission. Inhibition of p38 signaling abolished the AMPK-elicited reversion and forced activation of p38 in primed mEpiSCs partially reproduced the naïve cell induction, suggesting that p38 is one of the critical downstream in AMPK activation. Single cell RNA-seq analysis under AICAR stimulation successfully demonstrated the reversion process with appearance of intermediate naïve-like population. AMPK pathway should be a novel critical driving force in reversion of primed to naïve pluripotency.
Project description:We show activation of AMP kinase (AMPK) with single chemical compounds can endow naïve pluripotency. AMPK activators reverted early-stage differentiating cells or epi-stem cells to naïve state. Moreover, AMPK activators reverted human ESCs to naïve state with pluripotent gene expression profiles and X-chromosome reactivation.
Project description:We show activation of AMP kinase (AMPK) with single chemical compounds can endow naïve pluripotency. AMPK activators reverted early-stage differentiating cells or epi-stem cells to naïve state. Moreover, AMPK activators reverted human ESCs to naïve state with pluripotent gene expression profiles and X-chromosome reactivation.
Project description:scRNA-seq of mouse embryonic stem cells (mESC) derived from four different genetic backgrounds grown in ground state conditions and differentiated towards an epiblast stem cell like (EpiSCL) population.
Project description:Embryonic stem cell (ESC) cultures display a heterogeneous gene expression profile, ranging from a pristine naïve pluripotent state to a primed epiblast state. While it is known that the addition of inhibitors of GSK3β and MEK (so-called 2i conditions) push ESC cultures towards a more homogeneous naïve pluripotent state, the molecular underpinnings of this naïve transition are not completely understood. Here we demonstrate that Dazl, a RNA-binding protein previously thought to be expressed specifically in developing primordial germ cells (PGCs), marks a subpopulation of ESCs in vitro that is actively transitioning toward naïve pluripotency. In the absence of Dazl expression, ESCs fail to induce proper expression of Tet enzymes required for 5-hydroxymethylation in 2i-culture conditions. As a result, 5-hydroxymethylation of methylated cystosine residues is impaired. Indeed, we demonstrate that Tet1 and Tet2 are mRNA targets of Dazl, indicating that Dazl might play a role in protection or stabilizing these mRNA molecules. Our results provide insight in the regulation of the acquisition of naïve pluripotency and demonstrate that Dazl is required for TET-mediated cytosine hydroxymethylation in cells that are actively reprogramming to a pluripotent ground state. RNA-IP experiments were used to identify the RNA species bound to DAZL.