目的 评估丹参素对心肌缺血/再灌注（MI/R）损伤的保护作用及其可能机制。方法 32只大鼠随机分为假手术组、模型组组、丹参素30 mg/kg组和丹参素60 mg/kg组，丹参素组在再灌注开始后5 min内iv相应剂量丹参素，假手术组和模型组注射等量生理盐水；再灌注3 h后，向冠状动脉中注入2 mL的3%伊文思蓝染料；取大鼠动脉血和心脏，通过组织化学测定心肌梗死面积大小，通过ELISA测定血清中的肌酸激酶-同工酶（CK-MB）和心肌肌钙蛋白（cTnI）水平。通过氧糖剥夺/恢复（OGD/R）H9c2心肌细胞模型评估丹参素预处理对细胞的直接作用，使用MTT、ELISA和流式细胞术分别测定丹参素对细胞活力、乳酸脱氢酶（LDH）释放和细胞凋亡的影响，使用RT-PCR和Western blotting免疫印迹测定miR-199a-5p及其下游蛋白Akt和ERK1/2的表达。结果 丹参素治疗可显著降低心肌梗死面积以及血清中CK-MB和cTnI的水平（P<0.05）；丹参素预处理显著改善OGD/R心肌细胞活力恢复能力，减少细胞凋亡水平，显著提高Akt和ERK1/2的mRNA和蛋白表达水平，降低miR-199a-5p的mRNA表达水平（P<0.05）；上调miR-199a-5p显著降低Akt和ERK1/2的mRNA和蛋白表达水平（P<0.05），而下调miR-199a-5p可显著提高Akt和ERK1/2的mRNA和蛋白表达水平（P<0.05）。结论 丹参素可以通过抑制miR-199a-5p增加Akt和ERK1/2表达来发挥心脏保护作用。

Objective To evaluate the protective effects of Danshensu, the effective component of Salvia miltiorrhiza (Danshen), against myocardial ischemia/reperfusion (MI/R) injury in cardiomyocytes and its possible underlying mechanism. Methods 32 rats were randomly divided into four groups: sham operation group, model group, Danshensu 30 mg/kg group and Danshensu 60 mg/kg group. Danshensu 30 mg/kg group and Danshensu 60 mg/kg group were given all drugs intravenously within 5 min after reperfusion, sham operation group and model group were injected with the same amount of physiological saline. Three hours after reperfusion, 2 mL of 3% Evans was injected into the coronary artery. The size of myocardial infarction was determined by histochemistry. The levels of creatine kinase MB (CK-MB) and cardiac troponin (cTnI) in serum were measured by ELISA. In addition, the direct toxicity of Danshensu on cardiomyocytes was evaluated by oxygen glucose deprivation/recovery (OGD/R) model. MTT, ELISA and flow cytometry were used to determine the effects of Danshensu on cell viability, lactate dehydrogenase (LDH) release and apoptosis. RT-PCR and Western blotting were used to detect the effects of Danshensu on cell viability, LDH release and apoptosis. The expression of miR-199a-5p and its downstream proteins Akt and ERK1/2 were detected by Western blotting. Results Danshensu treatment significantly reduced myocardial infarction area and serum CK-MB and cTnI levels (P<0.05); Danshensu pretreatment significantly improved the viability of OGD/R myocardial cells, reduced the level of apoptosis, significantly increased the mRNA and protein expression levels of Akt and ERK1/2, and decreased the mRNA expression level of miR-199a-5p(P<0.05). Up regulation of miR-199a-5p significantly decreased the mRNA and protein expression levels of Akt and ERK1/2 (P<0.05), and down-regulation of miR-199a-5p significantly increased the mRNA and protein expression levels of Akt and ERK1/2 (P<0.05).Conclusion Danshensu provides the cardioprotective effects against MI/R injury via increasing Akt and ERK1/2 through inhibition of miR-199a-5p.

R285.5

国家重点研发项目（2017YFC1307602）；天津市科技计划项目（15ZXLCSY00040）