Wnt-Nanog互反馈调控环路的机制及其在表皮干细胞自我更新-分化的功能转换平衡中的作用

项目名称： Wnt-Nanog互反馈调控环路的机制及其在表皮干细胞自我更新-分化的功能转换平衡中的作用

项目编号： No.30872691

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 黄晖

作者单位： 华中科技大学

项目金额： 30万元

中文摘要： 由于表皮干细胞（ESC）增殖-分化转换意义重大，但调节机制不清。而Nanog是干细胞促增殖、抑分化关键因子，功能由其N/C末端同源结构域控制；Wnt控制ESC分化，βat是其关键点，功能受βat磷酸化状态控制，βat与Nanog间可能存在表达调控作用。 因此推测：Wnt-Nanog间存在互反馈调控环路，其机制通过调控βat磷酸化及Nanog的N/C末端功能实现；该环路动态控制ESC自我更新-分化功能的平衡转换。 为验证假设，通过观察βat与Nanog在ESC不同功能状态的表达及关联，并重点观察Nanog调控βat磷酸化以及后者对前者N/C末端功能的影响，最后探讨了它们对ESC增殖、分化间平衡的动态调控作用，从而验证Wnt-Nanog互反馈调控环路的存在的可能性及其分子机制和对ESC自我更新-分化功能转换的动态调节作用，为更精细控制ESC分化，促进创伤愈合提供理论依据。

中文关键词： βatenin；Nanog；磷酸化；调控；

英文摘要： Previous researches have verificated that βatenin expressed in ESCs is a key protein to switch on differentiation of ESCs and determine direction of ESCs differentiation. As an important glucoprotein of Wnt-signaling pathway，even low level of βatenin is necessary for ESCs to maintain stem cell state. Once its expression is up-regulated，ESCs will enter differentiation procedure. ESCs will develope toward hair follicle followed high expression ofβatenin，but will developed toward epidermis cells with removing βatenin. Hence it is very important to illuminate regulation mechanism of βatenin expression with an aim of controlling direction of ESCs differentiation，promoting follicle repair or reconstruction of follicle. Effect of SOX9S409A and SOX9S409E on the level of SOX9 phosphorylation at Ser404：A)Overexpression vector，wide type SOX9 and SOX9 mutations，SOX9 phosphorylation at Ser404 was detected by western blotting with pS404 and total SOX9 was detected with R134d. DM1A were used to load controls and marker forcytoplasmic fractions. B)Quantitative analysis of A.*，P<0.05(mean±SD，n=3)，compared with SOX9WT treated with DMSO group. CONCLUSIONS 1) SP is an important cytokine of up-regulating expression of βatenin in ESCs. 2) The regulation of βatenin by SP is realized through NK1-R and NK-2, but the latter is more important. 3) Exogenous SP can induce SP up-regulated. 4) SP from autocrine of ESCs plays an important role in regulating expression of βatenin, which is realized by up-regulation CK1ε 5) SP controls the expression of βatenin through mechanisms mentioned above and by which differentiation of ESCs is controlled. 6) Above results indicated that SP can be used to up-regulate expression of gene and protein of SP, then it acted as a signed of autocrine to up-regulate the expression of CK1εnd to enhance expression of βatenin gene and protein, ultimately to control differentiation of ESCs. This study produces an experimental basis for promoting wound-healing and improving healing quality by regulating differentiation of ESCs.

英文关键词： βatenin;Nanog;Differentiation;ESC