Restoring Pharmacologic Preconditioning in the Aging Heart: Role of Mitophagy/Autophagy
Restoring Pharmacologic Preconditioning in the Aging Heart: Role of Mitophagy/Autophagy
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DOI：
10.1093/gerona/glw168
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发表时间：
2017-04-01
影响因子：
5.1
通讯作者：
Liu, Lixin
中科院分区：
文献类型：
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作者：
Ma, Li;Zhu, Jiang;Liu, Lixin
我们以前报道过，预处理与有效的抗氧化剂TEMPOL改善线粒体功能和恢复预处理老化的心脏。由于线粒体自噬与心脏预处理有关，并随年龄增长而下降，本研究旨在研究年龄如何影响线粒体自噬对预处理的反应，以及TEMPO预处理是否改善了线粒体自噬。老年大鼠（22-24个月）用或不用4周TEMPO进行预处理，并与年轻大鼠（4-6个月）进行比较。分别在缺血/再灌注和模拟缺氧/复氧条件下，观察异氟醚（ISO）在体内和体外诱导的心肌保护作用。通过使用蛋白质印迹和免疫荧光技术比较关键线粒体吞噬标志物的水平/亚细胞位置来确定线粒体吞噬。ISO在体内和体外预处理年轻而非年老的心脏。衰老损害了ISO诱导的PINK 1和Parkin的线粒体积累，以及线粒体泛素化，以及通过LC 3斑点、膜相关LC 3-II和p62评估的基线和ISO诱导的自噬通量。TEMPOL预处理改善了这些过程，恢复了ISO预处理。抑制自噬废除ISO诱导的保护心肌细胞从年轻和TEMPOL预处理老年大鼠。因此，抗氧化剂预处理显着改善老年心肌对ISO的线粒体吞噬反应，这可能有助于恢复衰老动物的心脏保护作用。
We previously reported that pretreatment with the potent antioxidant TEMPOL improves mitochondrial function and restores preconditioning in the aging heart. Because mitophagy is implicated in cardiac preconditioning and declines with age, this study was designed to investigate how age influences mitophagy in response to preconditioning and whether TEMPOL pretreatment improves it. Old (22-24 months) rats were pretreated with or without 4-week TEMPOL and compared with young (4-6 months) untreated rats. Cardioprotection induced by isoflurane (ISO) in vivo and in isolated cardiomyocytes in vitro was assessed following ischemia/reperfusion and simulated hypoxia/reoxygenation, respectively. Mitophagy was determined by comparing the levels/subcellular locations of key mitophagic markers using Western blotting and immunofluorescence techniques. ISO preconditioned the young but not old heart in vivo and in vitro. Aging impaired ISO-induced mitochondrial accumulation of PINK1 and Parkin, as well as mitochondrial ubiquitination, and baseline and ISO-induced autophagic flux assessed by LC3 puncta, membrane associated LC3-II and p62. Pretreatment with TEMPOL improved these processes and restored ISO preconditioning. Inhibition of autophagy abolished ISO-induced protection in cardiomyocytes from young and TEMPOL pretreated old rats. Thus, antioxidant pretreatment significantly improves mitophagic response to ISO in old myocardium, which may contribute to restoration of cardioprotection in senescent animals.