Department of Cardiology, Taizhou First People's Hospital, Taizhou 318020, PR China.
Department of Cardiology, Taizhou First People's Hospital, Taizhou 318020, PR China.
Life Sci. 2021 May 1;272:119228. doi: 10.1016/j.lfs.2021.119228. Epub 2021 Feb 16.
The purpose of this study was to reveal the therapeutic efficacy and underlying mechanism of cannabinoid type 2 receptor agonist (AM1241) on myocardial ischemia-reperfusion injury (MIRI) in rats.
We established a rat myocardial ischemia/reperfusion (I/R) model and H9c2 hypoxia/reoxygenation (H/R) model. ELISA was used to determine the concentrations of cardiac troponin I (cTnI), creatine kinase-MB (CK-MB), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in plasma. EB/TTC staining was performed to observe the myocardial infarct size. Besides, the pathological changes of myocardial tissue were identified via H&E staining and Masson's trichrome staining. TUNEL assay was performed to examine myocardial apoptosis. Then, the protein expression of Pink1, Parkin and autophagy-related markers (Beclin-1, P62 and LC3) were detected by Western blot, and autophagy was evaluated by Mitotracker staining.
The results of EB/TTC staining, H&E staining, Masson's trichrome staining and cardiac enzymes measuring showed that AM1241 treatment significantly diminished infarct size, the structural abnormalities and the activities of cardiac enzymes (cTnI, CK-MB, AST and LDH). AM1241 also significantly reduced the number of TUNEL-positive cells induced by I/R in a dose-dependent manner. Furthermore, AM1241 activated Pink1/Parkin signaling pathway and upregulated autophagy level.
AM1241 exerts a protective effect against MIRI in rats by inducing autophagy through the activation of Pink1/Parkin pathway.
本研究旨在揭示大麻素 2 型受体激动剂（AM1241）对大鼠心肌缺血再灌注损伤（MIRI）的治疗效果及作用机制。
我们建立了大鼠心肌缺血/再灌注（I/R）模型和 H9c2 细胞缺氧/复氧（H/R）模型。采用 ELISA 法测定血浆中心肌肌钙蛋白 I（cTnI）、肌酸激酶同工酶-MB（CK-MB）、天门冬氨酸氨基转移酶（AST）和乳酸脱氢酶（LDH）的浓度。通过 EB/TTC 染色观察心肌梗死面积。此外，通过 H&E 染色和 Masson 三色染色鉴定心肌组织的病理变化。采用 TUNEL 检测法检测心肌细胞凋亡。然后，通过 Western blot 检测 Pink1、Parkin 和自噬相关标志物（Beclin-1、P62 和 LC3）的蛋白表达，并通过 Mitotracker 染色评估自噬。
EB/TTC 染色、H&E 染色、Masson 三色染色和心肌酶测定结果表明，AM1241 治疗可显著减少梗死面积、结构异常和心肌酶（cTnI、CK-MB、AST 和 LDH）活性。AM1241 还可显著减少 I/R 诱导的 TUNEL 阳性细胞数量，呈剂量依赖性。此外，AM1241 激活了 Pink1/Parkin 信号通路并上调了自噬水平。
AM1241 通过激活 Pink1/Parkin 通路诱导自噬，对大鼠 MIRI 发挥保护作用。
