缺氧微环境下微管相关蛋白4在人表皮细胞中的表达变化及对细胞迁移能力的影响

Expression of MAP4 in epidermal cells and its effect on cell migration under hypoxic microenvironment

目的在缺氧微环境下观察微管相关蛋白4(microtubule-associated protein 4,MAP4)在人永生化角质形成细胞株(HaCaT细胞株)中的表达变化及对细胞迁移能力的影响。方法利用Western blot检测早期缺氧后(1%O2,缺氧时间分别为0.5、1、3 h)MAP4在HaCaT细胞中的表达变化;设立正常细胞组、干扰MAP4组及阴性对照组(空病毒转染),采用免疫荧光、体外细胞划痕实验观察各组细胞缺氧后(1%O2)其细胞骨架的主要成分α-微管蛋白(α-tubulin)的变化情况以及细胞迁移能力的变化。结果①缺氧0.5 h,细胞中MAP4的表达会升高,随着缺氧时间延长(缺氧1、3 h),表达又迅速降低;②早期缺氧后各组细胞的微管动力学均发生变化,细胞骨架趋于松散解聚以利于迁移;③缺氧24 h后正常细胞组和阴性对照组的迁移能力较常氧24 h明显增强(P<0.05);常氧状态下,干扰MAP4组细胞的迁移能力比正常细胞组和阴性对照组细胞明显减弱(P<0.01),缺氧后细胞迁移能力未见明显增强。结论缺氧微环境调控了HaCaT细胞MAP4的表达,进而影响了细胞微管动力学的变化,增强了细胞的迁移能力。

Objective To observe the expression of microtubule-associated protein 4 （MAP4） in epidermal cell line （HaCaT cells）, and the effect of MAP4 on cell migration under hypoxic microenvironment. Methods All experiment samples were divided into 3 groups： HaCaT cell group, RNAi-MAP4 cell group and con-RNAi-HaCaT cell group. We detected the expression of MAP4 in HaCaT Cells under different hypoxic microenvironment （1% O2 for 0.5, 1 and 3 h, respectively） by Western blotting. Besides, we observed the expression of α-tubulin, an important component of cytoskeleton by fluorescence immunoassay. In addition, the migration of HaCaT cells was observed by in vitro cell scratch experiment. Results （1） The expression of MAP4 in HaCaT cells was increased after hypoxia （0.5 h） and decreased rapidly with the duration of hypoxia （1 h and 3 h ）. （2） In the early period of hypoxia, microtubule dynamics of different cells in each group was changed. The cytoskeleton became depolymerized, showing a tendency to migrate. （3） The migration ability of normal HaCaT cells and con-RNAi-HaCaT cells significantly increased after 24 h under hypoxic microenvironment （P〈0.05）. Under normoxia, the migration of RNAi-HaCaT cell was poorer than that of HaCaT cells and con-RNAi-HaCaT cells （P〈0.01）, and not increased after hypoxia. Conclusion The hypoxic microenvironment can enhance the migration ability of HaCaT cells by regulating MAP4 expression.