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
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
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.
更多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-Ⅱand 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/Aktratio (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.
More- 浏览:237
- 被引:7
- 下载:172
相似文献
- 中文期刊
- 外文期刊
- 学位论文
- 会议论文