Zhao Wei, Zhao Jia, Zhang Xiuying, Fan Ni, Rong Jianhui
School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, SAR China.
Zhujiang Hospital, Southern Medical University, Guangzhou, China.
Front Pharmacol. 2021 Sep 13;12:731980. doi: 10.3389/fphar.2021.731980. eCollection 2021.
Small ubiquitin-like modifier (SUMO) proteins modify proteins through SUMOylation as an essential protein post-translational modification (PTM) for regulating redox status, inflammation, and cardiac fibrosis in myocardial infarction. This study aimed to investigate whether natural product puerarin could alleviate myocardial ischemia/reperfusion injury (MI-RI) by targeting protein SUMOylation. Mouse MI-RI model was induced by ligating the left anterior descending (LAD) coronary artery and subsequently treated with puerarin at the dose of 100 mg/kg. Rat cardiomyocyte H9c2 cells were challenged by hypoxia/reoxygenation and treated with puerarin at concentrations of 10, 20, and 40 μM. The infarction area of mouse hearts was assessed by 2% TTC staining. Cell damage was analyzed for the release of lactate dehydrogenase (LDH) in serum and cell culture medium. Western blot technique was employed to detect the expression of SUMO2, phospho-ERK, pro-inflammatory biomarker COX2, fibrosis index galectin-3, apoptosis-related protein cleaved PARP-1. The activation of the estrogen receptor (ER) pathway was assayed by the dual-luciferase reporter system. The present study validated that puerarin effectively reduced myocardial infarct size and LDH release in the mouse MI-RI model. In the cell culture system, puerarin effectively decreased the release of LDH and the protein level of COX2, galectin-3, and cleaved PARP-1. Mechanistic studies revealed that puerarin increased the expression of SUMO2, SUMOylation of proteins and the activation of ER/ERK pathway in cardiomyocytes. ER, ERK and SUMO2 inhibitors attenuated the cardioprotective effects of puerarin. Puerarin may alleviate myocardial injury by promoting protein SUMOylation through ER/ERK/SUMO2-dependent mechanism.
小泛素样修饰物（SUMO）蛋白通过SUMO化修饰蛋白质，这是一种重要的蛋白质翻译后修饰（PTM），用于调节心肌梗死中的氧化还原状态、炎症和心脏纤维化。本研究旨在探讨天然产物葛根素是否可通过靶向蛋白质SUMO化来减轻心肌缺血/再灌注损伤（MI-RI）。通过结扎左冠状动脉前降支（LAD）诱导小鼠MI-RI模型，随后用100 mg/kg剂量的葛根素进行治疗。用缺氧/复氧处理大鼠心肌细胞H9c2，并分别用10、20和40 μM浓度的葛根素进行处理。通过2% TTC染色评估小鼠心脏的梗死面积。通过分析血清和细胞培养基中乳酸脱氢酶（LDH）的释放来检测细胞损伤。采用蛋白质印迹技术检测SUMO2、磷酸化ERK、促炎生物标志物COX2、纤维化指标半乳糖凝集素-3、凋亡相关蛋白裂解PARP-1的表达。通过双荧光素酶报告系统检测雌激素受体（ER）途径的激活情况。本研究证实，在小鼠MI-RI模型中，葛根素可有效减小心肌梗死面积并降低LDH释放。在细胞培养系统中，葛根素可有效降低LDH的释放以及COX2、半乳糖凝集素-3和裂解PARP-1的蛋白水平。机制研究表明，葛根素可增加心肌细胞中SUMO2的表达、蛋白质的SUMO化以及ER/ERK途径的激活。ER、ERK和SUMO2抑制剂可减弱葛根素的心脏保护作用。葛根素可能通过ER/ERK/SUMO2依赖性机制促进蛋白质SUMO化来减轻心肌损伤。
