Li Ruixuan, Wu Yuyan, Zhao Xiexiong, Chen Ye, Jiang Weihong, Li Xiaogang
Department of Cardiology, The Third Xiangya Hospital of Central South University.
Department of Cardiology, Hunan Provincial People's Hospital.
Int Heart J. 2025;66(4):628-638. doi: 10.1536/ihj.24-745.
Evidence suggests that autophagy plays a crucial role in myocardial ischemia/reperfusion (I/R) injury. Renalase (RNLS) plays a protective role in cardiovascular diseases, including myocardial ischemia/reperfusion injury (MI/RI). Therefore, we used both in vivo and in vitro I/R models to monitor autophagy in the cardiomyocytes by exposing H9c2 cells to oxygen and glucose deprivation/reoxygenation (OGD/R) and subjecting rats to I/R, respectively. Wistar rats (male, 8 weeks, n = 27) were randomly divided into a Sham group, I/R + Vehicle group, and I/R + recombinant renalase protein (Re-RNLS) group. An MI/RI model was induced by left anterior descending artery ligation/release, TTC-Evans blue double staining was utilized to evaluate the area of myocardial infarction and ischemic area 24 hours after the operation, and plasma lactate dehydrogenase (LDH) and creatine kinase (CK) activities, plasma RNLS, epinephrine, and dopamine concentrations were detected by ELISA. H9c2 cells were treated with OGD/R serum and pretreated with Re-RNLS, chloroquine (CQ), and MK2206. Western blotting detected protein expression changes in LC3 autophagosomes were monitored by immunofluorescence, and cell death was determined by flow cytometry. The level of RNLS in serum was significantly increased during MI/RI in rats, and Re-RNLS significantly reduced myocardial infarct size after I/R surgery (24.6 ± 4.1% versus 11.2 ± 1.2%). RNLS deficiency aggravated the OGD/R injury in H9c2 cells, and Re-RNLS inhibited the expression of LC3 and Beclin-1 in H9c2 cells subjected to OGD/R, thereby reducing autophagosome formation. Re-RNLS activated the Akt/mTOR pathway of H9c2 cells to play a cytoprotective role. RNLS protects against MI/RI injury by inhibiting autophagy through activating the Akt/mTOR pathway.
有证据表明自噬在心肌缺血/再灌注（I/R）损伤中起关键作用。肾酶（RNLS）在包括心肌缺血/再灌注损伤（MI/RI）在内的心血管疾病中发挥保护作用。因此，我们分别使用体内和体外I/R模型，通过将H9c2细胞暴露于氧和葡萄糖剥夺/复氧（OGD/R）以及对大鼠进行I/R来监测心肌细胞中的自噬。将Wistar大鼠（雄性，8周龄，n = 27）随机分为假手术组、I/R + 溶媒组和I/R + 重组肾酶蛋白（Re-RNLS）组。通过左冠状动脉前降支结扎/松开诱导MI/RI模型，术后24小时利用TTC-伊文思蓝双重染色评估心肌梗死面积和缺血面积，并通过ELISA检测血浆乳酸脱氢酶（LDH）和肌酸激酶（CK）活性、血浆RNLS、肾上腺素和多巴胺浓度。用OGD/R血清处理H9c2细胞，并用Re-RNLS、氯喹（CQ）和MK2206进行预处理。通过蛋白质印迹法检测蛋白质表达变化，通过免疫荧光监测LC3自噬体，通过流式细胞术测定细胞死亡情况。大鼠MI/RI期间血清中RNLS水平显著升高，Re-RNLS显著减小I/R手术后的心肌梗死面积（24.6 ± 4.1%对11.2 ± 1.2%）。RNLS缺乏加重了H9c2细胞的OGD/R损伤，Re-RNLS抑制了OGD/R处理的H9c2细胞中LC3和Beclin-1的表达，从而减少自噬体形成。Re-RNLS激活H9c2细胞的Akt/mTOR途径发挥细胞保护作用。RNLS通过激活Akt/mTOR途径抑制自噬来保护心肌免受MI/RI损伤。
