国际麻醉学与复苏杂志   2018, Issue (5): 1-1
    
自噬和PI3K-Akt-mTOR信号转导通路在缺氧预处理对高糖心肌细胞缺氧/复氧损伤保护中的作用
孙超, 杨桂珍, 薛富善, 李慧娴, 刘亚洋, 廖旭1()
1.中国医学科学院整形外科医院
The roles of autophagy and PI3K-Akt-mTOR signaling transduction pathway in protection of high-glucose cultured cardiomyocytes against hypoxia/reoxygenation injury by hypoxia preconditioning
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摘要：

目的　探讨自噬和磷脂酰肌醇3激酶（phosphatidylinositol 3 hydroxy kinase， PI3K）-蛋白激酶B（protein kinase B， Akt)-雷帕霉素靶蛋白（mammalian target of rapamycin， mTOR）信号转导通路在缺氧预处理（hypoxia preconditioning， HPC）对高糖心肌细胞缺氧/复氧（anoxia/reoxygenation， AR）损伤中的作用及机制。　方法　将采用高糖培养基培养72 h的心肌细胞用随机数字表法分为5组：空白对照组（S组）、AR损伤对照组（AR组）、HPC组、渥曼青霉素+HPC组（Wo+HPC组）、雷帕霉素+HPC组（Ra+HPC组）。采用乳酸脱氢酶（lactate dehydrogenase， LDH）检测试剂盒检测心肌细胞LDH漏出率，Annexin V/PI双染流式细胞术检测心肌细胞凋亡情况，蛋白印迹法检测心肌细胞微管相关蛋白1轻链3（microtubulesas sociated protein light， LC3）-Ⅱ、Beclin-1、mTOR、PI3K表达和磷酸化（phospho， p）蛋白激酶B/蛋白激酶B（p-Akt/Akt）比值。　结果　与AR组比较，Wo+HPC组LDH漏出率、早期和晚期凋亡率降低（P<0.05），LC3-Ⅱ和Beclin-1表达降低（P<0.05），mTOR、PI3K表达和p-Akt/Akt比值升高（P<0.05）。HPC组各指标与AR组比较，差异均无统计学意义（P>0.05）。与HPC组比较，Wo+HPC组LDH漏出率、早期和晚期凋亡率降低（P<0.05），Beclin-1表达降低（P<0.05），mTOR、PI3K表达和p-Akt/Akt比值升高（P<0.05）。　结论　激活PI3K-Akt-mTOR信号转导通路抑制自噬可明显改善HPC对高糖心肌细胞AR损伤的保护作用。
关键词： 心肌细胞；　高糖；　缺氧/复氧损伤；　缺氧预处理；　自噬；　磷脂酰肌醇3激酶
Abstract:

Ｏｂｊｅｃｔｉｖｅ　To assess the roles of autophagy and phosphatidylinositol 3 hydroxy kinase(PI3K)-protein kinase B(Akt)-mammalian target of rapamycin(mTOR) signaling transduction pathway in protection of high-glucose cultured cardiomyocyte against anoxia/reoxygenation (AR) injury by hypoxia preconditioning (HPC).　Methods　Ccardiomyocytes cultured in high-glucose medium for 72 h were randomly divided into 5 groups: high glucose control group (S group), AR injury control group (AR group), HPC group, wortmannin+HPC group (Wo+HPC group), rapamycin+HPC group. Lactate dehydrogenase (LDH) leakage and cardiomyocyte apoptosis were analyzed. Microtubulesas sociated protein light(LC3)-Ⅱ, Beclin-1, PI3K, mTOR and phospho(p)-Akt/Akt ratio in cardiomyocytes were assessed by Western-blot assay.　Results　Compared with AR group, Wo+HPC group showed decrease in the leakage rate of LDH, the percentages of early and late apoptosis, and the levels of LC3-Ⅱ and Beclin-1 (P<0.05), but increases in levels of mTOR and PI3K, and p-Akt/Akt ratio in cardiomyocytes (P<0.05), however, HPC group exhibited no significant difference in these parameters(P>0.05). Compared with the HPC group, Wo+HPC group displayed significant decreases in the leakage rate of LDH, the percentages of early and late apoptosis, and the levels of Beclin-1(P<0.05), but elevation of mTOR and PI3K, and p-Akt/Akt ratio(P<0.05).　Conclusions　Activation of PI3K-Akt-mTOR signaling transduction pathway and inhibition of autophagy can significantly improve the protection of high-glucose cultured cardiomyocytes against AR injury by HPC.
Key words: Cardiomyocytes;　High?蛳glucose culture;　Anoxia/reoxygenation injury;　Hypoxia preconditioning;　Autophagy;　Phosphatidylinositol 3 hydroxy kinase-protein kinase B-mammalian target of rapamycin signaling transduction pathway