糖尿病基础研究

　　【摘要】 目的 探讨利拉鲁肽对波动性高糖诱导的内皮细胞氧化损伤的影响及潜在机制。 方法 分离培养人脐静脉内皮细胞，分为正常葡萄糖对照(NC)组、持续性高糖(HG)组、波动性高糖(FG)组、高渗对照(HC)组、FG+利拉鲁肽 (Lira)组和FG+Lira+Exendin(9-39)组，各组均干预4 d。采用流式细胞仪检测细胞内活性氧簇 (ROS) 水平和细胞凋亡比率，采用Western blot检测活化Caspase-3蛋白水平。 结果 与NC组相比，HG和FG组ROS水平升高 [(129.4±4.1)% vs 100%;(130.5±1.2)% vs 100%，P<0.05]，细胞凋亡比率增加 [(21.6±1.7)% vs (14.8±3.9)% ;(25.1±5.8)% vs (14.8±3.9)%，P<0.05]，FG组活化Caspase-3蛋白水平升高 [(223.6±2.4)% vs 100%，P<0.05]。与FG组相比，FG+Lira 组ROS水平降低 [(109.8±4.3)% vs (133.2±1.9)%，P<0.05]，细胞凋亡比率降低 [(17.3±3.9)% vs (26.5±4.2)%，P<0.05]，活化Caspase-3蛋白水平降低 [(110.3±6.4)% vs (223.6±2.4)%，P<0.05]。添加Exendin(9-39) 可部分消除FG+Lira 组的上述效应。 结论 利拉鲁肽抑制波动性高糖诱导的内皮细胞氧化损伤，其作用至少部分是呈GLP-1受体依赖性的。

　　【关键词】 利拉鲁肽;波动性高糖;内皮;氧化应激;凋亡

　　【Abstract】Objectives To investigate the effect of liraglutide on endothelial cell oxidative damage induced by fluctuating glucose and the potential mechanism involved. Methods Cultured human umbilical vein endothelial cells were randomized into several groups including normal glucose control (NC), constant high glucose (HG), fluctuating high glucose (FG), hyperosmotic control (HC), FG+liraglutide (Lira) and FG+Lira+exendin Exendin(9-39), a GLP-1 receptor antagonist. After incubation for four days, the level of intracellular reactive oxidative species (ROS) and the ratio of apoptotic cells were measured by flow cytometry, and the level of activated caspase-3 protein was determined by western blot. Results The levels of intracellular ROS [(129.4±4.1)% vs 100%;(130.5±1.2)% vs 100%, P<0.05], and the percentages of apoptotic cells [(21.6±1.7)% vs (14.8±3.9)%;(25.1±5.8)% vs (14.8±3.9)%, P<0.05) were significantly increased in the HG and FG groups compared with those in the NC group. The level of activated caspase-3 protein was remarkably increased in the FG group when compared with the NC group [(223.6±2.4)% vs 100%, P<0.05]. Importantly, the level of intracellular ROS [(109.8±4.3)% vs (133.2±1.9)%, P<0.05], the percentages of apoptotic cells [(17.3±3.9)% vs (26.5±4.2)%, P<0.05] and the level of activated caspase-3 protein [(110.3±6.4)% vs (223.6±2.4)%, P<0.05] in the FG+Lira group were significantly lower than those in the FG group. Moreover, the above effects of FG+Lira group were partly abolished by adding exendin(9-39). Conclusion Liraglutide protects endothelial cells against oxidative damage induced by fluctuating high glucose, which is at least partly dependent on GLP-1 receptor.

　　【Key words】 Liraglutide;Glycemic fluctuation;Endothelium;Oxidative stress;Apoptosis