Li Yanyan, Xiang Yin, Zhang Song, Wang Yan, Yang Jie, Liu Wei, Xue Fengtai
Department of Cardiovascular Diseases, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University1665 Kongjiang Road, Shanghai 200092, China.
Am J Transl Res. 2017 Oct 15;9(10):4428-4439. eCollection 2017.
The aim of this study is to explore the role of thioredoxin-2 (Trx2) in autophagy and apoptosis during myocardial ischemia-reperfusion (I/R) injury in vivo. In the study, adult male Sprague-Dawley rats were assigned to four groups at random and pretreated with normal saline (sham operation and I/R groups) and either a control lentivirus (Lv-GFP-N) or one expressing Trx2 (Lv-GFP-Trx2). Sevendays after pretreatment, rat MIRI models were produced via occlusion of the left anterior descending coronary artery for 30 min followed by reperfusion for 6 h. Hearts and blood were harvested to assess efficiency of lentivirus transfection via immunofluorescence staining, quantitative RT-PCR and western blotting, oxidative stress via the malondialdehyde level and superoxide dismutase activity, myocardial damage via myocardial enzymelevels and histopathological staining, myocardial apoptosis via TUNEL assays and western blotting, and myocardial autophagy viawestern blotting. Our results showed thatthe delivery of Lv-GFP-Trx2 into the myocardium remarkably increased Trx2 expression. The upregulation of Trx2 contributed to alleviation of oxidative stress, attenuation of myocardial histological damage, reduced leakage of myocardial enzyme and decrease in infarct size. Moreover, the overexpression of Trx2 was significantly associated with thedecreased incidence of apoptosis via ASK1-dependent intrinsic mitochondrial apoptotic pathwayand autophagy via the mammalian target of rapamycin (mTOR) pathway. The study indicates that upregulation of Trx2 protectsthe myocardium from MIRI and isinvolved inthe inhibition of apoptosis and autophagy. Therefore, Trx2 isa promising therapeutic strategy for attenuating MIRI.
本研究旨在探讨硫氧还蛋白-2（Trx2）在体内心肌缺血再灌注（I/R）损伤过程中自噬和凋亡中的作用。在该研究中，成年雄性Sprague-Dawley大鼠被随机分为四组，分别用生理盐水预处理（假手术组和I/R组），以及用对照慢病毒（Lv-GFP-N）或表达Trx2的慢病毒（Lv-GFP-Trx2）预处理。预处理7天后，通过结扎左冠状动脉前降支30分钟，随后再灌注6小时，制备大鼠心肌缺血再灌注损伤（MIRI）模型。采集心脏和血液，通过免疫荧光染色、定量逆转录聚合酶链反应（RT-PCR）和蛋白质免疫印迹法评估慢病毒转染效率，通过丙二醛水平和超氧化物歧化酶活性评估氧化应激，通过心肌酶水平和组织病理学染色评估心肌损伤，通过TUNEL检测和蛋白质免疫印迹法评估心肌细胞凋亡，通过蛋白质免疫印迹法评估心肌自噬。我们的结果表明，将Lv-GFP-Trx2导入心肌可显著增加Trx2表达。Trx2的上调有助于减轻氧化应激、减轻心肌组织学损伤、减少心肌酶泄漏并减小梗死面积。此外，Trx2的过表达与通过ASK1依赖的内源性线粒体凋亡途径导致的凋亡发生率降低以及通过雷帕霉素靶蛋白（mTOR）途径导致的自噬显著相关。该研究表明，Trx2的上调可保护心肌免受MIRI损伤，并参与抑制凋亡和自噬。因此，Trx2是减轻MIRI的一种有前景的治疗策略。
