Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA.
Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA; Paul G. Allen School of Computer Science & Engineering, University of Washington, Seattle, WA 98195, USA.
Dev Cell. 2020 Jan 27;52(2):236-250.e7. doi: 10.1016/j.devcel.2019.12.018.
Regulation of embryonic diapause, dormancy that interrupts the tight connection between developmental stage and time, is still poorly understood. Here, we characterize the transcriptional and metabolite profiles of mouse diapause embryos and identify unique gene expression and metabolic signatures with activated lipolysis, glycolysis, and metabolic pathways regulated by AMPK. Lipolysis is increased due to mTORC2 repression, increasing fatty acids to support cell survival. We further show that starvation in pre-implantation ICM-derived mouse ESCs induces a reversible dormant state, transcriptionally mimicking the in vivo diapause stage. During starvation, Lkb1, an upstream kinase of AMPK, represses mTOR, which induces a reversible glycolytic and epigenetically H4K16Ac-negative, diapause-like state. Diapause furthermore activates expression of glutamine transporters SLC38A1/2. We show by genetic and small molecule inhibitors that glutamine transporters are essential for the H4K16Ac-negative, diapause state. These data suggest that mTORC1/2 inhibition, regulated by amino acid levels, is causal for diapause metabolism and epigenetic state.
胚胎休眠的调控,即打断发育阶段与时间之间紧密联系的休眠,目前仍知之甚少。在这里,我们描述了小鼠休眠胚胎的转录组和代谢组特征,并确定了独特的基因表达和代谢特征,这些特征与激活的脂肪分解、糖酵解以及由 AMPK 调节的代谢途径有关。脂肪分解因 mTORC2 抑制而增加,增加脂肪酸以支持细胞存活。我们进一步表明,在着床前 ICM 来源的小鼠 ESCs 中饥饿诱导可逆休眠状态,在转录上模拟体内休眠阶段。在饥饿期间,AMPK 的上游激酶 Lkb1 抑制 mTOR,诱导可逆的糖酵解和表观遗传 H4K16Ac 阴性、休眠样状态。休眠进一步激活谷氨酰胺转运体 SLC38A1/2 的表达。我们通过遗传和小分子抑制剂表明,谷氨酰胺转运体对于 H4K16Ac 阴性休眠状态是必需的。这些数据表明,mTORC1/2 的抑制,受氨基酸水平的调节,是休眠代谢和表观遗传状态的原因。