尿石素A改善高糖致血管内皮损伤的作用与机制

目的探讨尿石素A(urolithin A,UA)对高糖所致的内皮细胞损伤的保护作用及可能机制。方法将人脐静脉内皮细胞分为正常组(5.5 mmol葡萄糖)、高糖组(33.3 mmol葡萄糖)、高糖+UA处理组、高糖+UA+Compound C处理组。分别检测了细胞存活及细胞的一氧化氮(nitric oxide,NO)和内皮素(endothelin-1,ET-1)浓度。通过二氢乙锭荧光探针染色和超氧化物歧化酶(superoxide dismutase,SOD)活性分析细胞氧化应激水平。采用Western blot进一步分析了细胞内皮型一氧化氮合酶(endothelial nitric oxide synthase,e NOS)和腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)的磷酸化水平。结果与高糖对照组相比,UA干预使内皮细胞的存活升高(P<0.05);SOD活性升高(P<0.05),活性氧簇(reactive oxygen species,ROS)水平降低(P<0.05);NO分泌增高及ET-1浓度降低(P<0.05);明显上调AMPK和eNOS磷酸化水平(P<0.05),差异有统计学意义。而在AMPK抑制剂Compound C处理后UA对内皮细胞的上述作用被逆转。结论 UA通过激活AMPK/eNOS通路,抑制高糖介导的血管内皮氧化应激,改善内皮功能障碍。

Effect and mechanism of urolithin A on high glucose-induced endothelial injury

Objectives To explore the protective effect and mechanism of urolithin A(UA)on endothelial cells induced by high glucose.Methods There were four endothelial cell groups in this study:normal glucose group(NG group,5.5 mmol glucose),high glucose group(HG group,33.3 mmol glucose),high glucose+UA treatment group(HG+UA group)and high glucose+UA+Compound C(Com C)treatment group(HG+UA+Com C group).Cell viability,nitric oxide(NO)and endothelin-1(ET-1)concentrations were detected.The level of oxidative stress was evaluated by Dihydroethidium fluorescent probe and superoxide dismutase(SOD).The phosphorylation levels of endothelial nitric oxide synthase(e NOS)and AMP-activated protein kinase(AMPK)were detected by Western blot.Results Compared with HG group,the cell viability and concentrations of NO and ET-1 in UA treatment group increased(P<0.05);SOD activity increased and the levels of reactive oxygen species(ROS)reduced(P<0.05)in UA treatment group;phosphorylation levels of AMPK and eNOS increased(P<0.05)in UA treatment group;phosphorylation levels of AMPK and e NOS increased(P<0.05)in UA treatment group.While these effects of UA on endothelial cells was reversed after incubating with Compound C.Conclusions UA can ameliorate high glucose-induced oxidative stress injury and improve endothelium dysfunction by activating the AMPK/eNOS pathway.