8细胞胚胎紧密化中多个信号通路对Ezrin磷酸化的调控

Blastomeres in late mouse eight-cell embryos compact and become polarized, initiating the differentiation of the inner cell mass and the trophectoderm. Ezrin and its phosphorylation at threonine 567 play important role in embryo compaction. However, the regulatory mechanism of Ezrin phosphorylation remains unknown. We previously found that Mek/Erk, PKC and Rho GTPases regulate Ezrin phosphorylation during 8-cell embryo compaction. Thus, we proposed to study how Mek/Erk, PKC and Rho GTPases regulate the expression and distribution of Ezrin and phosphorylated Ezrin, as well as the interaction and relationship between these signaling molecules and polarizing molecules in eight-cell embryos. We will also take advantage of in vitro culture of trophectodermal stem cells to identify the kinase responsible for the phosphorylation of Ezrin. Our proposed studies will shed lights on the molecular mechanisms of 8-cell embryo compaction and polarization, advance our understanding of pre-implantation embryogenesis, and contribute to preventing the failure of pre-implantation development and enhancing the success rate of reproduction.

小鼠胚胎在8细胞晚期发生卵裂球的紧密化和极化,从而为后来内细胞团和滋养层细胞的分化打下基础。Ezrin以及Ezrin苏氨酸567的磷酸化在胚胎紧密化中起着重要作用。但是，胚胎紧密化中Ezrin磷酸化的调控机制尚未被阐明。我们前期数据表明Mek/Erk、PKC和Rho激酶信号通路在8细胞胚胎紧密化中对Ezrin磷酸化都有影响，但调控机制不同。本项目中，我们将研究Mek/Erk、PKC和Rho GTPases如何影响Ezrin和p-Ezrin在8细胞胚胎中的表达和分布,结合在滋养层干细胞中的研究找出催化Ezrin T567磷酸化的蛋白激酶,并阐明这几个信号通路和极性分子之间的相互作用,从而加深我们对8细胞胚胎极化和紧密化的分子机理的理解.该研究有助于理解胚胎着床前发育的分子机理，对防止自然堕胎和提高生殖的成功率也有巨大的现实意义。

小鼠胚胎在8细胞晚期发生卵裂球的紧密化和极化,从而为后来内细胞团和滋养层细胞的分化打下基础。Ezrin以及Ezrin苏氨酸567的磷酸化在胚胎紧密化中起着重要作用。但是，胚胎紧密化中Ezrin磷酸化的调控机制尚未被阐明。本项目中，我们研究了在8细胞胚胎中，Mek/Erk、PKC和Rho GTPases调控Ezrin磷酸化的机制，发现Rho GTPases促进aPKC和Ezrin在顶膜区的极性分布，而Mek/Erk和aPKC都参与调控顶膜区Ezrin的磷酸化，其中aPKC是直接磷酸化Ezrin的激酶。这些结果加深我们对8细胞胚胎极化和紧密化的分子机理的理解，对防止自然堕胎和提高生殖的成功率有巨大的现实意义。此外，我们还研究了Erk信号、Klf5乙酰化、天然反义RNA和Cops2在小鼠胚胎干细胞的多能性维持中功能和作用机制。