自噬在缺血预适应减少急性心肌缺血-再灌注损伤中的作用  

The Role of Autophagy in IPC-mediated Cardioprotection

作　　者：刘艺[1] 徐卫娟[2] 柯丽[2] 李云桥[2] 彭雯[2] 

机构地区：[1]武汉亚洲心脏病医院心外科,武汉430022 [2]华中科技大学同济医学院附属协和医院老年医学科,武汉430022

出　　处：《微循环学杂志》2013年第3期16-18,22,F0002,I0001,共6页Chinese Journal of Microcirculation

基　　金：湖北省自然科学基金计划项目(No:2011CDB382)

摘　　要：目的:探讨缺血预适应(IPC)减少大鼠急性心肌缺血再灌注(I/R)损伤与自噬的关系。方法:雄性SD大鼠32只,随机均分为四组:假手术组(Sham组)、缺血/再灌注组(I/R组)、缺血预适应组(IPC组)和自噬抑制剂渥曼青霉素组(Wort组)。通过冠脉结扎术建立大鼠心肌I/R模型。Sham组只穿线,不结扎,I/R组,结扎30min,再灌120min;IPC组于I/R前结扎5min、再灌注5min,重复3次后再结扎30min,再灌注120min;Wort组在进行IPC前15min给予Wort15μg/Kg腹腔注射。应用TUNEL法检测各组细胞凋亡指数(AI);电镜观察各组心肌细胞自噬和线粒体形态学改变;Western Blotting测定各组心肌微管相关蛋白1轻链3-II(LC3-II)蛋白表达。结果:I/R组凋亡较多,AI较Sham组明显增加(P<0.01),线粒体超微结构损伤加重,自噬体数量较多,LC3-II表达增加(P<0.05);与I/R组相比,IPC组凋亡减少,AI较I/R组明显下降(P<0.01),线粒体超微结构损伤减轻,自噬体数量增多,LC3-II表达增强(P<0.05);Wort组较其它三组心肌AI明显增加(P<0.01),线粒体超微结构损伤加重,未见自噬体。结论:IPC可能通过自噬途径减轻I/R所致心肌损伤。Objective: To investigate whether the protection of ischemic preconditioning (IPC) against myocardial ischemia/reperfusion (I/R) injury is mediated by autophagy pathway. Method: 32 healthy male SD rats were randomly divided into Sham group,I/R group,IPC group and Wort group. We established an acute myocardial ischemia-reperfusion model where the left anterior descending coronary artery (LAD) was ligated for 30 min and reperfused for 120 min in vivo. IPC group was achieved by three cycles of pre-ischemic for 5 min followed by a persistent reperfusion for 5 min. Wort group used 15μg/Kg wortmannin which was a specific inhibitor of autophagy 15 min before the IPC. TUNEL method was used to detect apoptosis of cardiomyocytes. The formation of autophagosomes was observed by transmission electron microscopy. Expression of microtubule-associated protein 1 light chain 3II(LC3-II)was measured by the Western blotting. Results: Comparing with Sham group, I/R group increased apoptosis of cardiomyocytes (P<0.01); Comparing with I/R group, IPC reduced apoptosis of cardiomyocytes (P<0.01); whereas wortmannin dramatically enhanced cardiomyocytes apoptosis (P<0.01). A number of autophagic vacuoles (AVs) were observed in the cardiac myocytes of IPC group comparing to I/R group. Comparing with I/R group, less AVs were observed and serious damage of mitochondria in wort group; LC3-II formation, an autophagy marker, was up-regulated in the IPC group, which more increased than I/Rinjured rats (P<0.05). Conclusion: These results suggest that IPC may protect against myocardial I/R injury by promotion of autophagy pathway.

关 键 词：自噬 缺血再灌注损伤 缺血预适应 细胞凋亡 

分 类 号：R541[医药卫生—心血管疾病]