Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, RTP, North Carolina, USA.
Stem Cells. 2012 May;30(5):910-22. doi: 10.1002/stem.1070.
Embryonic stem cell (ESC) identity and self-renewal is maintained by extrinsic signaling pathways and intrinsic gene regulatory networks. Here, we show that three members of the Ccr4-Not complex, Cnot1, Cnot2, and Cnot3, play critical roles in maintaining mouse and human ESC identity as a protein complex and inhibit differentiation into the extraembryonic lineages. Enriched in the inner cell mass of blastocysts, these Cnot genes are highly expressed in ESC and downregulated during differentiation. In mouse ESCs, Cnot1, Cnot2, and Cnot3 are important for maintenance in both normal conditions and the 2i/LIF medium that supports the ground state pluripotency. Genetic analysis indicated that they do not act through known self-renewal pathways or core transcription factors. Instead, they repress the expression of early trophectoderm (TE) transcription factors such as Cdx2. Importantly, these Cnot genes are also necessary for the maintenance of human ESCs, and silencing them mainly lead to TE and primitive endoderm differentiation. Together, our results indicate that Cnot1, Cnot2, and Cnot3 represent a novel component of the core self-renewal and pluripotency circuitry conserved in mouse and human ESCs.
胚胎干细胞 (ESC) 的特性和自我更新由外在信号通路和内在基因调控网络维持。在这里，我们表明 Ccr4-Not 复合物的三个成员，Cnot1、Cnot2 和 Cnot3，作为一个蛋白质复合物在维持小鼠和人类 ESC 特性方面发挥着关键作用，并抑制向胚胎外谱系分化。这些 Cnot 基因在囊胚的内细胞团中富集，在 ESC 中高表达，并在分化过程中下调。在小鼠 ESCs 中，Cnot1、Cnot2 和 Cnot3 对于在正常条件下和支持原始多能性的 2i/LIF 培养基中的维持都是重要的。遗传分析表明，它们不通过已知的自我更新途径或核心转录因子发挥作用。相反，它们抑制早期滋养外胚层 (TE) 转录因子的表达，如 Cdx2。重要的是，这些 Cnot 基因对于人类 ESCs 的维持也是必需的，沉默它们主要导致 TE 和原始内胚层分化。总之，我们的结果表明 Cnot1、Cnot2 和 Cnot3 代表了在小鼠和人类 ESCs 中保守的核心自我更新和多能性回路的一个新组成部分。
