美国伊利诺斯大学芝加哥分校Bradley J. Merrill小组取得一项新突破。他们提出了细胞内Ca²⁺稳态和核出口介导了细胞从幼稚多能状态中退出。 2019年8月出版的《细胞—干细胞》发表了这项成果。

研究团队使用CRISPR诱变技术进行小鼠胚胎干细胞(ESCs)的筛选，以确定核出口和细胞内Ca²⁺稳态在脱离多能性的原始状态时的影响。 由Atp2b1编码的质膜Ca²⁺泵的突变增加了细胞内Ca²⁺浓度，从而克服了细胞内Ca²⁺减少的影响，这是退出幼稚状态所必需的。实验结果表明，限定培养基中传代的Atp2b1- /- Tcf7l1 -/ -双敲除ESC（无LIF或抑制剂），以及在仅含有降钙素和GSK3抑制剂的培养基中传代的野生型细胞中，均支持ESC的持续自我更新。这些新发现均提示细胞内Ca²⁺在保护幼稚多能方面发挥着重要作用。

研究人员表示，哺乳动物早期胚胎细胞需要发展多能性，以便从高度的自我更新向谱系规范的能力过渡。

附：英文原文

Title: Intracellular Ca2+ Homeostasis and Nuclear Export Mediate Exit from Naive Pluripotency

Author: Matthew S. MacDougall, Ryan Clarke, Bradley J. Merrill

Issue&Volume: Volume 25 Issue 2

Abstract: Progression through states of pluripotency is required for cells in early mammalian embryos to transition away from heightened self-renewal and toward competency for lineage specification. Here, we use a CRISPR mutagenesis screen in mouse embryonic stem cells (ESCs) to identify unexpected roles for nuclear export and intracellular Ca 2+ homeostasis during the exit out of the naive state of pluripotency. Mutation of a plasma membrane Ca 2+ pump encoded by Atp2b1 increased intracellular Ca 2+ such that it overcame effects of intracellular Ca 2+ reduction, which is required for naive exit. Persistent self-renewal of ESCs was supported both in Atp2b1 / Tcf7l1 / double-knockout ESCs passaged in defined media alone (no LIF or inhibitors) and in wild-type cells passaged in media containing only calcitonin and a GSK3 inhibitor. These new findings suggest a central role for intracellular Ca 2+ in safeguarding naive pluripotency.

DOI: https://doi.org/10.1016/j.stem.2019.04.015

Source: https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(19)30164-X