褪黑素通过Akt/mTOR信号通路对自噬和H9C2心肌细胞缺血再灌注损伤的影响

Effects of Melatonin on Autophagy and Ischemia-reperfusion Injury of H9C2 Myocardial Cells through Akt/mTOR Signaling Pathway

目的探讨褪黑素(Mel)通过Akt/mTOR信号通路对自噬和H9C2心肌细胞缺血再灌注损伤的作用及机制。方法选取H9C2心肌细胞,建立模拟缺血再灌注(SIR)模型,应用Mel、西罗莫司(SRL)和Akt抑制剂(Akti)处理分组。检测各组细胞形态变化、凋亡情况以及自噬和凋亡相关蛋白的表达。结果与正常H9C2心肌细胞比较,SIR模型出现了显著的细胞凋亡,且凋亡和自噬相关蛋白表达增加(P<0.01);经Mel处理后,SIR模型的凋亡和自噬蛋白表达降低,Akt和mTOR磷酸化水平升高(P<0.01)。另外,经Mel和Akti共同处理以及经Mel和SRL共同处理后,SIR模型的Akt和mTOR磷酸化水平降低,自噬和凋亡相关蛋白表达升高(P<0.01)。结论 Mel可通过上调Akt/mTOR信号通路抑制自噬,减轻H9C2心肌细胞的缺血再灌注损伤。

Objective To investigate effect and mechanism of melatonin (Mel) on autophagy and ischemia-reperfusion injury of H9C2 myocardial cells through Akt/mTOR signaling pathway. Methods H9C2 myocardial cells were selected to establish simulated ischemia reperfusion (SIR) models. Mel, Sirolimus (SRL) and Akti inhibitor were used to treat the groups. Morphological changes, apoptosis conditions and expressions of autophagy and apoptosis-related proteins were detected in all groups. Results Compared with those in normal H9C2 myocardial cells, apoptosis rate and expressions of autophagy-related proteins were significantly increased in SIR models ( P <0.01). After treatment by Mel, apoptosis rate and expression of autophagy protein were significantly decreased, while phosphorylation levels of Akt and mTOR were significantly increased in SIR models ( P <0.01). After treatments by Mel combined with Akti and Mel combined with SRL, in SIR models, phosphorylation levels of Akt and mTOR were significantly decreased, while expressions of autophagy and apoptosis-related proteins were significantly increased ( P <0.01). Conclusion Mel may inhibit autophagy by up-regulating Akt/mTOR signaling pathway and alleviate ischemia-reperfusion injury of H9C2 myocardial cells.