Exendin-4对Ⅰ型糖尿病小鼠内皮祖细胞功能及AKT/eNOS信号通路的影响

目的探讨Exendin-4对Ⅰ型糖尿病小鼠内皮祖细胞(endothelial progenitor cells,EPCs)增殖、迁移、黏附、衰老的影响及对AKT/eNOS信号通路的影响。方法采用密度梯度离心法分离并培养6月龄Ⅰ型糖尿病小鼠EPCs,并用不同浓度的Exendin-4(1、5、10、25μmol·L^-1)处理EPCs,观察EPCs体外克隆形成及增殖能力。同时观察其对糖尿病小鼠EPCs迁移、黏附及衰老的影响。Western blot检测Exendin-4处理对EPCs蛋白激酶B/内皮型一氧化氮合酶(AKT/eNOS)信号通路的影响。结果Exendin-4处理可增加Ⅰ型糖尿病小鼠EPCs克隆形成及增殖能力,尤以10μmol·L^-1时作用效果最佳。Exendin-4处理可增加Ⅰ型糖尿病小鼠EPCs的体外迁移、黏附功能,并抑制细胞衰老。Western blot结果显示,Exendin-4可增强AKT及eNOS磷酸化水平,而GLP-1R抑制剂Exendin-9-39和AKT抑制剂MK-2206则可以阻断这种效应。结论Exendin-4可改善Ⅰ型糖尿病小鼠EPCs增殖、迁移、黏附能力并抑制细胞衰老,其机制可能与调控AKT/eNOS信号通路有关。

Effect of Exendin-4 on endothelial progenitor cell function and AKT/eNOS signaling pathway in a mouse model of type 1 diabetes

Aim To investigate the effect of Exendin-4 on proliferation,migration,adhesion and senescence of endothelial progenitor cells(EPCs)in typeⅠdiabetic mice and its possible mechanism.Methods EPCs from 6-month diabetic mice were isolated and cultured by density gradient centrifugation.Cells were treated with different concentrations of Exendin-4(1,5,10,25μmol·L^-1)for seven days to observe the colony-formation and proliferation capacity in vitro.The effects of Exendin-4 on the migration,adhesion and senescence of EPCs were also observed.The effect of Exendin-4 on the signaling pathway of protein kinase B/endothelial nitric oxide synthetase(AKT/eNOS)was detected by Western blot.Results Exendin-4 could increase the colony-formation and proliferation ability of EPCs in type I diabetic mice in a dose-dependent manner,especially for 10μmol·L^-1.Compared with control group,the treatment of 10μmol·L^-1 Exendin-4 could increase the migration and adhesion function of EPCs in vitro and inhibit cell senescence.The results of Western blot showed that the phosphorylation of AKT and eNOS was significantly enhanced by 10μmol·L^-1 Exendin-4 treatment,which was blocked by the GLP-1R inhibitor Exendin-9-39 and the AKT inhibitor MK-2206.Conclusions Exendin-4 can improve the proliferation,migration,adhesion capacities and inhibit senescence of EPCs in type Ⅰ diabetic mice,which may be related to the regulation of AKT/eNOS signaling pathway.