目的 探讨芍药内酯苷改善缺氧/复氧（hypoxia/reoxygenation，H/R）诱导的心肌细胞损伤的作用机制。方法 H/R诱导大鼠H9c2心肌细胞建立心肌缺血再灌注损伤模型，给予芍药内酯苷干预，检测丙二醛（malondialdehyde，MDA）水平及超氧化物歧化酶（superoxide dismutase，SOD）、谷胱甘肽过氧化物酶（glutathione peroxidase，GSH-Px）活性；流式细胞术测定细胞凋亡率；Western blotting检测凋亡相关蛋白表达；qRT-PCR检测miR-219a-5p表达。转染miR-219a-5p mimics或anti-miR-219a-5p，考察下调miR-219a-5p对芍药内酯苷改善H/R诱导的心肌细胞损伤作用的影响。体内建立缺血再灌注（ischemia/ reperfusion，I/R）小鼠模型，给予芍药内酯苷干预，检测血清中肌酸激酶同工酶（creatine kinase isoenzyme，CK-MB）活性和心肌肌钙蛋白T（cardiac troponin T，cTnT）水平；检测心肌组织MDA水平及SOD、GSH-Px活性；采用苏木素-伊红（HE）染色考察心肌组织病理变化；采用TTC染色检测心肌组织梗死情况。结果 与对照组比较，模型组H9c2细胞MDA水平、细胞凋亡率及剪切型半胱氨酸天冬氨酸蛋白酶-3（cleaved cystein-asparate protease-3，cleaved Caspase-3）、cleaved Caspase-9蛋白表达水平显著上升（P＜0.05），而miR-219a-5p表达、SOD、GSH-Px活性显著下降（P＜0.05）；给予芍药内酯苷干预后，MDA水平、细胞凋亡率及凋亡相关蛋白表达显著降低（P＜0.05），miR-219a-5p表达、SOD、GSH-Px活性显著升高（P＜0.05），且呈剂量相关性；下调miR-219a-5p表达后，显著逆转了芍药内酯苷对H/R诱导的心肌细胞损伤的抑制作用（P＜0.05）。体内结果与体外结果一致，芍药内酯苷显著缓解了I/R引发的小鼠心肌组织损伤和凋亡。结论 芍药内酯苷通过调控miR-219a-5p表达而抑制心肌细胞氧化应激及凋亡，从而减轻H/R诱导的心肌细胞损伤。

Objective To explore the mechanism of albiflorin on improving hypoxia/reoxygenation (H/R)-induced myocardial cell injury. Methods H/R was used to induce H9c2 cardiomyocytes to establish a myocardial ischemia-reperfusion injury model. Albiflorin was used to intervene, the level of malondialdehyde (MDA) and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were detected; Flow cytometry was used to measure the apoptosis rate of cells; Western blotting was used to detect the expressions of apoptosis-related proteins; qRT-PCR was used to detect the expression of miR-219a-5p. miR-219A-5p mimetics or anti-miR-219a-5p was transfected to investigate the effect of down-regulating of miR-219a-5p on improvement of H/R-induced myocardial cell injury by albiflorin. An ischemia-reperfusion (I/R) mouse model in vivo was established, albiflorin was used to intervene, creatine kinase isoenzyme (CK-MB) activity and cardiac troponin T (cTnT) level in serum were detected; Levels of MDA and activities of SOD and GSH-Px in myocardial tissue were detected; Hematoxylin eosin (HE) staining was used to investigate pathological changes in myocardial tissue; TTC staining was used to detect myocardial tissue infarction. Results Compared with control group, MDA level, apoptosis rate, and expression levels of cleaved cysteine aspartate protease-3 (cleaved Caspase-3) and cleaved Caspase-9 proteins in H9c2 cells of model group were significantly increased (P < 0.05), while the expression of miR-219a-5p, SOD and GSH Px activities were significantly decreased (P < 0.05); After intervention with albiflorin, MDA level, apoptosis rate, and expressions of apoptosis related proteins were significantly reduced (P < 0.05), while miR-219a-5p expression, SOD and GSH Px activity were significantly increased (P < 0.05), and showed a dose-dependent relationship; After down-regulating the expression of miR-219a-5p, the inhibitory effect of albiflorin on H/R-induced myocardial cell injury was significantly reversed (P < 0.05). The in vivo and in vitro results were consistent, albiflorin significantly alleviated myocardial tissue damage and apoptosis induced by I/R. Conclusion Albiflorin inhibits oxidative stress and apoptosis of myocardial cells by regulating the expression of miR-219a-5p, thereby alleviating H/R-induced myocardial cell damage.

R285.5

河南省医学科技攻关计划项目（LHGJ20230886）