exendin-4对高糖条件下人系膜细胞细胞外基质代谢的影响

Effects of exendin-4 on extracellular matrix metabolism in human mesangial cells cultured in high glucose

目的探讨exendin-4对高糖条件下人系膜细胞(HMC)细胞外基质(ECM)代谢的影响及其可能的机制。方法取对数生长期的HMC分为正常对照(NG)组、渗透压对照(Man)组、高糖(HG)组和高糖联合不同浓度exendin-4(1、10、100 nmol/L)组。体外培养HMC,采用cck8法测24 h HMC增殖情况;Western Blotting检测细胞培养15 min后细胞外调节激酶(ERK)/p-ERK蛋白表达情况,24 h后Ⅰ型胶原、纤维连接蛋白(FN)、转化生长因子β1(TGF-β1)蛋白表达情况。结果 CCK-8结果显示高糖诱导HMC 24 h后可见细胞增殖明显增强(1±0.06 vs 1.20±0.07,P<0.001),加入exendin-4后可抑制细胞增殖(1.12±0.02 vs 1.20±0.07,P<0.05,1.05±0.08 vs 1.20±0.07,P<0.001)。细胞培养24 h后,与NG组相比,HG组细胞Ⅰ型胶原、FN、TGF-β1蛋白表达量均显著增加(P<0.001);与HG组相比,高糖联合exendin-4组Ⅰ型胶原、FN、TGF-β1蛋白表达量均显著降低(P<0.01)。细胞培养15 min后,与NG组相比,HG组细胞ERK磷酸化蛋白表达量较NG组显著增加(P<0.001);与HG组相比,高糖联合exendin-4组ERK磷酸化蛋白表达量显著下降(P<0.001)。渗透压对照组与正常对照组各指标间差异均无统计学意义。结论 Exendin-4可能通过抑制TGF-β1/ERK通路活性对高糖条件下HMC ECM代谢起到了保护性的调节作用。

Objective To explore effects of exendin-4 on the metabolism of extracellular matrix（ECM） in human mesangial cells（HMC） cultured in the presence of high glucose and explore the possible mechanism. Methods Human mesangial cells（HMC）were treated with exendin- 4 under high glucose conditions. The cell proliferation was observed using CCK8 assay, and the expressions of collagen type I, fibronectin, transforming growth factor- β1（TGFβ1） expression and extracellular signalregulated kinase（ERK） signaling pathway activity were assessed using Western blotting. Results Exendin- 4 inhibited cell proliferation and the expressions of collagen type I, fibronectin and TGFβ1 and reversed ERK phosphorylation in high glucoseinduced HMC. Conclusion Exendin- 4 can regulate ECM metabolism in HMC cultured in high glucose by inhibiting TGFβ1/ERK pathway, suggesting the beneficial effects of exendin-4 in preventing and treating diabetic nephropathy.