Department of Cardiology, Heart Center, Zhujiang Hospital of Southern Medical University, NO. 253, Gongye Avenue, 510282, Guangzhou, China.
Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, 450052, Zhengzhou, China.
Biochem Biophys Res Commun. 2018 Sep 18;503(4):2421-2428. doi: 10.1016/j.bbrc.2018.06.171. Epub 2018 Jul 3.
Gastrodin (GAS), a monomeric component exacted from the herb Gastrodia elata Bl, may have cardioprotective effects during injury caused by myocardial ischemia/reperfusion (I/R). For the significant role of autophagy in I/R process, we targeted to explore whether autophagy was contributing to the GAS-induced protective effects during I/R procedure. Male C57BL/6 mice were subjected to reversible left coronary artery ligation and cultured neonatal rat cardiomyocytes (NRCs) exposed to hypoxia were preconditioned with GAS prior to ischemia or hypoxia, following reperfusion for 2 h or re-oxygennation for 3 h respectively. Our results demonstrated that GAS pretreatment increased autophagy and reduced apoptosis during I/R, this effect was weakened by co-treatment with the autophagic flux inhibitor chloroquine (Cq). Compared to mice subjected solely to I/R, GAS-pretreated mice had a notably smaller heart infarct size and an elevation in cardiac function. In GAS-pretreated NRCs, WB data showed that autophagy was promoted (expression of p62 was inhibited and LC3II was increased). In addition, tandem fluorescent mRFP-GFP-LC3 assays illustrated that autophagosomes were degraded duo to an increase in autophagic flux. Co-administration of Cq blocked the autophagic flux. Furthermore, GAS pretreatment increased the mitochondrial membrane potential of NRCs with subjected to H/R and increased the cardiomyocyte survival rate. These protective effects were reversed with Cq. Besides, GAS-induced the enhaucement of autophagy may correlated with activating AMP-activated protein kinase (AMPK) phosphorylation and reduced Mammalian target of rapamycin (mTOR) phosphorylation, which was abrogated by Compound C (Com C, AMPK-specific inhibitor). Our results establish that GAS pretreatment attenuates myocardial I/R injury by increasing autophagic flux aimed at eliminating dysfunctional mitochondria, therefore protecting neighbouring mitochondria and cardiomyocytes.
天麻（GAS）是从天麻草药中提取的单体成分，可能对心肌缺血/再灌注（I / R）损伤具有心脏保护作用。由于自噬在 I / R 过程中的重要作用，我们旨在探索自噬是否有助于 GAS 在 I / R 过程中诱导的保护作用。雄性 C57BL / 6 小鼠接受可逆性左冠状动脉结扎，培养的新生大鼠心肌细胞（NRCs）在缺血或缺氧前用 GAS 预处理，然后分别进行再灌注 2 h 或再氧合 3 h。结果表明，GAS 预处理可增加 I / R 过程中的自噬并减少细胞凋亡，该作用可被自噬流抑制剂氯喹（Cq）减弱。与仅接受 I / R 的小鼠相比，GAS 预处理的小鼠心脏梗塞面积明显减小，心功能明显提高。在 GAS 预处理的 NRCs 中，WB 数据显示自噬被促进（p62 的表达被抑制，LC3II 增加）。此外，串联荧光 mRFP-GFP-LC3 测定表明自噬体被降解，因为自噬流增加。Cq 的共给药阻断了自噬流。此外，GAS 预处理可增加经历 H / R 的 NRCs 的线粒体膜电位并增加心肌细胞存活率。用 Cq 逆转这些保护作用。此外，GAS 诱导的自噬增强可能与激活 AMP 激活的蛋白激酶（AMPK）磷酸化和减少雷帕霉素靶蛋白（mTOR）磷酸化有关，而 Cq（AMPK 特异性抑制剂）则阻断了这一作用。我们的研究结果表明，GAS 预处理通过增加旨在消除功能失调线粒体的自噬流来减轻心肌 I / R 损伤，从而保护相邻的线粒体和心肌细胞。
