干细胞中两个关键细胞因子Oct4和Sox2

Two Key Cell Factors of Stem Cells Oct4 and Sox2

胚胎干细胞(ESC)在谱系特异性标志被激活前,Oct4和Sox2蛋白水平是细胞向谱系选择发展过程中的连续临时性标志。Oct4和Sox2转录因子在启动细胞重编程、维持ESC多能性和决定其是否走向分化方面具有关键作用。它通过与靶基因调控区结合,选择性地抑制分化基因或者激活多能性基因的表达而达到调控目的。干细胞共激活复合物(SCC)是Oct4和Sox2在Nanog基因协同激活时所需要的,它直接与Oct4和Sox2相互作用并集中在Nanog和Oct4启动子部位以及大部分被Oct4和Sox2占据的基因组区域,在维持ES细胞多能性和保持基因组完整性方面发挥着重要功能。因此,对Oct4、Sox2这两个关键性细胞因子作用机制深入了解,有助于细胞重编程分子机制的进一步阐明,为干细胞的相关研究奠定基础。

Before the activation of cell lineage specific marker,the protein expression levels of Oct4 and Sox2 in embryonic stem cell are continuously temporary marker for cell lineage selection.Oct4 and Sox2 transcription factors play an essential role in initiating cell reprogramming,maintaining stemness of pluripotent stem cell and deciding whether or not to differentiate.This selectively inhibits the expression of differentiation gene or activate the expression of pluripotency genes via a combination with target gene regulatory region to attain their regulatory purpose.A stem cell coactivator complex（SCC） is selectively required for the synergistic activation of the Nanog gene by Oct4 and Sox2.It interacts directly with Oct4 and Sox2 and is recruited to the Nanog and Oct4 promoters as well as a majority of genomic regions that are occupied by Oct4 and Sox2.This identifies it has dual function in maintaining ES cell pluripotency and safeguarding genome integrity.Understanding the mechanism of the two key factors of Oct4 and Sox2 deeply is helpful for elucidating the molecular mechanism of cell reprogramming and laying the foundation in stem cell-related studies.