Pluripotent stem cells (PSCs) transition between cell states in vitro, reflecting developmental changes in the early embryo. PSCs can be stabilized in the naive state by blocking extracellular differentiation stimuli, particularly FGF–MEK signalling. Here, we report that multiple features of the naive state in human and mouse PSCs can be recapitulated without affecting FGF–MEK signalling or global DNA methylation. Mechanistically, chemical inhibition of CDK8 and CDK19 (hereafter CDK8/19) kinases removes their ability to repress the Mediator complex at enhancers. CDK8/19 inhibition therefore increases Mediator-driven recruitment of RNA polymerase II (RNA Pol II) to promoters and enhancers. This efficiently stabilizes the naive transcriptional program and confers resistance to enhancer perturbation by BRD4 inhibition. Moreover, naive pluripotency during embryonic development coincides with a reduction in CDK8/19. We conclude that global hyperactivation of enhancers drives naive pluripotency, and this can be achieved in vitro by inhibiting CDK8/19 kinase activity. These principles may apply to other contexts of cellular plasticity.

多能干细胞 (PSC) 在体外细胞状态之间的转变，反映了早期胚胎的发育变化。通过阻断细胞外分化刺激，特别是 FGF-MEK 信号传导，PSCs 可以稳定在幼稚状态。在这里，我们报告了人类和小鼠 PSC 中幼稚状态的多个特征可以在不影响 FGF-MEK 信号传导或全局 DNA 甲基化的情况下被概括。从机制上讲，CDK8 和 CDK19（以下称为 CDK8/19）激酶的化学​​抑制消除了它们在增强子处抑制介体复合物的能力。因此，CDK8/19 抑制增加了介体驱动的 RNA 聚合酶 II (RNA Pol II) 向启动子和增强子的募集。这有效地稳定了幼稚的转录程序，并赋予了对 BRD4 抑制增强子扰动的抵抗力。而且，胚胎发育过程中的幼稚多能性与 CDK8/19 的减少相吻合。我们得出结论，增强剂的全局过度激活驱动幼稚多能性，这可以通过抑制 CDK8/19 激酶活性在体外实现。这些原则可能适用于细胞可塑性的其他环境。