艾塞那肽通过SDF-1/CXCR-4/Rho GTPase通路增强脂肪来源间充质干细胞的趋化性迁移

摘要

Objective To investigate the effect of exenatide on chemotactic migration of adipose-derived stem cells (ADSCs) and confirm that Rho GTPase is the downstream effector protein of SDF-1/CXCR-4 migration pathway. Methods ADSCs were isolated, cultured, identified by flow cytometry, and induced to differentiate in vitro. RTCA xCELLigence system was used to analyze the effect of exenatide on ADSC proliferation. The effects of exenatide at different concentrations, AMD3100 (CXCR-4 antagonist), and CCG-1423 (Rho GTPase antagonist) on chemotactic migration of ADSCs were tested using Transwell assay. The expression of CXCR-4 in exenatide-treated ADSCs was measured by flow cytometry and Western blotting. Active Rho pull-down detection kit was used to detect the expression of Rho GTPase. Laser confocal microscopy was used to observe the formation of stress fibers in ADSCs with different treatments. Result Exenatide treatment for 24 h had no significant effect on ADSC proliferation. Exenatide obviously promoted chemotactic migration of ADSCs in a concentration-dependent manner, and this effect was blocked by either AMD3100 or CCG-1423. Both flow cytometry and Western blotting showed that exenatide dose-dependently up-regulated CXCR-4 expression in ADSCs. Western blotting showed that the expression of Rho GTPase was related to SDF-1/CXCR-4 pathway, and laser confocal microscopy revealed that the formation of stress fibers in ADSCs was related to SDF-1/CXCR-4/ Rho GTPase pathway. Conclusion Exenatide promotes chemotactic migration of ADSCs, and Rho GTPase is the downstream effector protein of SDF-1/CXCR-4 pathway.%目的：探究艾塞那肽对脂肪来源间充质干细胞（ADSCs）迁移的影响，并证实Rho GTPase为SDF-1/CXCR-4迁移通路的下游效应蛋白。方法分离并培养大鼠来源ADSCs并通过流式细胞术及体外诱导分化鉴定。应用RTCA xCELLigence系统检测艾塞那肽对ADSCs增殖能力的影响。Transwell观察不同浓度艾塞那肽，AMD3100（CXCR-4阻断剂），CCG-1423（Rho GTPase阻断剂）处理对ADSCs趋化性迁移能力的影响。流式细胞术及Western blot技术分别检测不同艾塞那肽浓度处理组细胞CXCR-4蛋白表达水平。活化的Rho蛋白pull-down检测试剂盒检测艾塞那肽处理组和AMD3100阻断组Rho GTPase表达情况。激光共聚焦显微镜观察不同处理组细胞应力纤维形成情况。结果 RTCA xCELLigence系统提示艾塞那肽处理24h内对ADSCs的增殖能力无明显影响。艾塞那肽呈浓度依赖性的增加ADSCs的趋化性迁移能力，AMD3100及CCG-1423可阻断这种效应（P<0.05）。流式细胞术及Western blotting结果都表明CXCR-4蛋白随艾塞那肽处理浓度升高而表达上调。此外， Western blot实验证实Rho GTPase的表达受SDF-1/CXCR-4通路影响。共聚焦显微镜观察到应力纤维的形成与SDF-1/CXCR-4/Rho GTPase通路相关。结论艾塞那肽能增强ADSCs的趋化性迁移能力，Rho GTPase为SDF-1/CXCR-4经典归巢通路的下游效应蛋白。