慢性间歇性低氧对大鼠胰岛β细胞功能的影响及利拉鲁肽对胰岛β细胞的保护作用

Effects of chronic intermittent hypoxia on pancreatic β-cell function in rats and protective effect of liraglutide on the pancreatic β cells

目的观察慢性间歇性低氧对大鼠胰岛β细胞功能的影响,探讨胰高糖素样肽-1(GLP-1)类似物利拉鲁肽对胰岛β细胞的保护作用。方法 36只SD雄性大鼠随机分为常氧对照组12只,间歇性低氧组24只。造模第8周结束后,两组大鼠均进行胰岛β细胞原代提取,常氧对照组随机分为常氧组和高糖刺激组;间歇性低氧组随机分为模型组、利拉鲁肽(10、50、100 nmol/L)干预组。ELISA法检测各组大鼠胰岛β细胞上清中8-异前列腺素(8-ISO)及谷胱甘肽过氧化物酶(GSH-Px)表达水平;流式细胞仪检测各组胰岛β细胞凋亡率; Western-blot法检测胰岛β细胞凋亡相关蛋白Caspase-3表达。结果与正常对照组比较,模型组和高糖刺激组大鼠胰岛β细胞上清液中8-ISO水平升高,而GSH-Px在模型组及高糖刺激组低于正常对照组,差异有统计学意义(P <0. 05);同时,模型组及高糖刺激组胰岛β细胞凋亡率升高,Caspase-3在胰岛β细胞表达上调,差异有统计学意义(P <0. 05),但高糖刺激组较模型组差异更明显。与模型组比较,利拉鲁肽干预后胰岛β细胞上清液中8-ISO水平降低,而GSH-Px升高,差异有统计学意义(P <0. 05);药物干预后Caspase-3蛋白表达低于模型组,且高浓度组较中低浓度组变化更明显。结论间歇性低氧导致的氧化应激可能是睡眠呼吸暂停综合征胰岛功能损伤的重要机制,GLP-1类似物利拉鲁肽通过对氧化物质的调节,从而减轻胰岛β细胞凋亡,保护胰岛β细胞。

Objective To observe the effects of chronic intermittent hypoxia on pancreatic β-cell function in rats and to investigate the protective effect of glucagon like peptide-1（GLP-1） analogues liraglutide on the pancreatic β cells. Methods 36 male SD rats were randomly divided into normal control group（ n =12） and intermittent hypoxia group（ n =24）. After 8 weeks′ intermittent hypoxia, the primary islet β cells were extracted from all the subjects in both groups. The primary β cells of the normal control group were divided into normal control subgroup and high glucose（30 mmol/L） stimulation subgroup while the intermittent hypoxia group were divided into model subgroup and liraglutide（10, 50, 100 nmol/L） treatment subgroups. The levels of 8-iso-prostaglandin（8-ISO） and glutathione peroxidase（GSH-Px） in the cell culture supernatants were detected by enzyme linked immunosorbent assay（ELISA）. The apoptosis rate of islet β cells in each group was detected by Flow Cytometry and the expression of caspase-3（an apoptosis-related protein） was detected by Western blot. Results The levels of 8-ISO were significantly higher while the levels of GSH-Px lower in the model group and the high glucose stimulation group than those in the normal control group（ P〈0.05）. Meanwhile, the apoptosis rates and the expressions of caspase-3 protein of the islet β cells in the model group and the high glucose stimulation group were significantly higher than those in the normal control group（ P〈0.05）, but those were higher in the high glucose stimulation group than in the model group. Compared with that in the model group, the 8-ISO level was significantly lower while GSH-Px level was significantly higher in the liraglutide treatment groups（ P〈0.05）. The expressions of Caspase-3 protein were significantly lower in the liraglutide treatment groups than those in the model group, and those in the high concentration group were more significant than those in the middle concentration group or the low concentration group. Conclusion Oxidative stress caused by intermittent hypoxia may be an important mechanism of the islet function damage in obstructive sleep apnea syndrome（OSAS）. Regulation of oxidation production by GLP-1 analogues liraglutide may reduce the apoptosis of islet β cells and protect the pancreatic β-cell function.