Exendin-4通过JNK和ERK信号通路增强大鼠脂肪来源干细胞的增殖

Exendin-4 Promotes Proliferation of Adipose-derived Stem Cells Via JNK and ERK Signaling Pathway

目的:探讨Exendin-4对大鼠脂肪来源干细胞的(Adipose-derived stem cells,ADSCs)增殖作用及其机制。方法:体外分离培养SD大鼠腹股沟处脂肪组织,流式细胞学方法鉴定分离的ADSCs,使用Exendin-4(Ex-4,0-50 nm/L)对P4代(第四代)ADSCs进行干预,采用MTT检测ADSCs的增殖情况,Western blot检测MAPK通路中JNK和ERK的磷酸化水平,使用相应的阻断剂来观测JNK和ERK通路对ADSCs增殖作用的影响。结果:分离培养的ADSCs高表达CD29、CD90和CD105,低表达CD31、CD34和CD45,符合间充质干细胞的表型。Ex-4以浓度依赖方式促进ADSCs体外增殖,10 nm/L为最适促增殖处理浓度。同时,Ex-4可以提高细胞中c-Jun和ERK的磷酸化水平,而给予相应阻断剂后,磷酸化蛋白表达减弱,细胞增殖能力也明显减弱。结论:Ex-4可以通过JNK和ERK通路增强大鼠脂肪来源干细胞的增殖。

Objective： To explore the effects and mechanism of Exendin-4（Ex-4）on the proliferation of adipose-derived stem cells （ADSCs）. Methods： ADSCs used in this study were obtained from inguinal region in Sprague-Dawley rats and flow cytometry analysis was conducted to detect surface antigens of ADSCs. After cells were treated with Ex-4 with different concentrations （0-50 nm/L）, the proliferation was measured with MTT test and the level of phospho-JNK and phospho-ERK were evaluated by Western blot. Next, inhibitor of JNK and ERK signaling pathways was applied to further establish the role of JNK and ERK in Ex-4-mediated cells proliferation. Results： ADSCs were positive for CD29, CD90 and CD105, but negative for CD31, CD34, and CD45, which was in line with the characteristics ofmescenchymal stem cells. Ex-4 could increase the proliferation of ADSCs in vitro in a concentration dependent manner and 10 nm/L was the optimum concentration （P〈0.05）. Meanwhile, Ex-4 elevated the phosphorylation level of JNK and ERK. However, application of inhibitors of JNK and ERK signaling pathway not only reversed such effects of Ex-4 on JNK and ERK, but diminished the Ex-4-involved up-regulation of proliferation in ADSCs. Conclusions： Ex-4 increased proliferative capacity of ADSCs via JNK and ERK signaling pathway.