Department of Internal Medicine II, Shandong Police Officer General Hospital, Jinan City, China.
Department of Emergency, Zhangqiu District People's Hospital, Jinan City, China.
Cell Biochem Funct. 2021 Mar;39(2):287-295. doi: 10.1002/cbf.3578. Epub 2020 Aug 7.
Ischaemia/reperfusion (I/R) injury can lead to severe arrhythmia and aggravate myocardial damage. Exosomes are small-membrane vesicles that play a protective role in myocardial I/R injury. This study aimed to explore the protective effects of ischaemic preconditioning (IPC)-induced serum exosomes (IPC-Exo) on myocardial I/R injury in rats and its underlying mechanism. Serum exosomes were extracted from IPC rats and quantified using a bicinchoninic acid assay kit. IPC-Exo (50 μg) was injected into the infarcted myocardium immediately after ligation. Rats were randomly divided into Sham, I/R, IPC-Exo + I/R, I/R + LY294002, and I/R + IPC-Exo + LY294002 groups. Haemodynamic parameters were measured by physiological recording. Transthoracic echocardiography was used to detect cardiac function. The serum levels of creatine kinase isomer-MB, lactate dehydrogenase, aspartate transaminase, tumour necrosis factor-alpha, interleukin (IL)-1β, and IL-10 were detected by enzyme-linked immunosorbent assay. Triphenyl tetrazolium chloride staining was used to measure the myocardial infarct size. Apoptosis in myocardial tissues was detected by TUNEL staining. Western blotting was used to detect the levels of PI3K/AKT and apoptosis-related proteins. Our results showed that treatment with IPC-Exo ameliorated cardiac function and reduced inflammatory factor production, cardiomyocyte apoptosis, and myocardial infarct size. Moreover, IPC-Exo treatment promoted the protein expression of Bcl-2, p-PI3K, and p-AKT but inhibited that of caspase-3 and Bax. However, treatment with LY294002 significantly reversed that IPC-Exo-induced increase in p-PI3K and p-AKT levels, improvement of haemodynamics, and decrease of inflammatory factor production and apoptosis in the I/R + IPC-Exo group. Taken together, our results suggest that IPC-Exo may alleviate I/R injury via activating the PI3K/AKT signalling pathway.
缺血/再灌注（I/R）损伤可导致严重心律失常并加重心肌损伤。外泌体是一种小膜囊泡，在心肌 I/R 损伤中发挥保护作用。本研究旨在探讨缺血预处理（IPC）诱导的血清外泌体（IPC-Exo）对大鼠心肌 I/R 损伤的保护作用及其机制。使用二辛可宁酸试剂盒测定从 IPC 大鼠中提取的血清外泌体并进行定量。结扎后立即将 IPC-Exo（50μg）注入梗死心肌。大鼠随机分为假手术组、I/R 组、IPC-Exo+I/R 组、I/R+LY294002 组和 I/R+IPC-Exo+LY294002 组。通过生理记录仪测量血流动力学参数。经胸超声心动图检测心功能。酶联免疫吸附试验检测肌酸激酶同工酶-MB、乳酸脱氢酶、天冬氨酸转氨酶、肿瘤坏死因子-α、白细胞介素（IL）-1β和 IL-10 的血清水平。三苯基四氮唑氯化物染色法测量心肌梗死面积。TUNEL 染色检测心肌组织细胞凋亡。Western blot 检测 PI3K/AKT 及凋亡相关蛋白水平。结果表明，IPC-Exo 治疗可改善心功能，减少炎症因子产生、心肌细胞凋亡和心肌梗死面积。此外，IPC-Exo 治疗可促进 Bcl-2、p-PI3K 和 p-AKT 蛋白表达，抑制 caspase-3 和 Bax 蛋白表达。然而，LY294002 治疗可显著逆转 IPC-Exo 诱导的 p-PI3K 和 p-AKT 水平升高、改善血流动力学以及减少 I/R+IPC-Exo 组炎症因子产生和凋亡。综上所述，本研究结果表明，IPC-Exo 可能通过激活 PI3K/AKT 信号通路缓解 I/R 损伤。
