金丝桃苷对慢性心力衰竭大鼠心脏功能及自噬相关蛋白表达的影响

Effects of hyperoside on cardiac function and expressions of autophagy-related proteins in rats with chronic heart failure

目的 探讨金丝桃苷对心力衰竭大鼠心脏功能的影响及其可能的作用机制。方法 SD大鼠随机分为假手术组[6只,氯化钠溶液2 mL/(kg·次)]、模型组[6只,氯化钠溶液2 mL/(kg·次)]、治疗组[6只,金丝桃苷30 mg/(kg·次)],每日腹腔注射给药1次,连续给药4周。采用彩色超声心动图检查记录大鼠心动图指标;采用醋酸铀-硝酸铅双重染色观察心肌组织形态学改变;Western blot检测自噬相关蛋白的表达。采用新生大鼠心肌细胞体外建立心肌细胞损伤模型,分为对照组、异丙肾上腺素(isoproterenol,ISO)模型组、金丝桃苷组及自噬抑制组,免疫荧光染色检测心肌细胞自噬情况。结果 与模型组比较,治疗组大鼠超声心动图指标左心室射血分数(LVEF)、左心室缩短率(LVFS)明显升高(P<0.05),左心室舒张末期室间隔厚度(IVSd)、收缩末期左心室后壁厚度(LVPWs)、收缩期室间隔厚度(IVSs)和舒张期左心室后壁厚度(LVPWd)明显降低(P<0.05);大鼠心肌病理学改变有明显改善。Westernblot结果显示,治疗组大鼠心肌组织中微管相关蛋白轻链3(microtubuleassociated protein 1 light chain 3,LC3)II/LC3I比例、Beclin-1蛋白表达水平下降(P<0.05),p62蛋白表达水平增加(P<0.05)。免疫荧光染色显示,对照组、ISO模型组、金丝桃苷组及自噬抑制组细胞中自噬体数分别为(4.3±2.02)个、(39.8±6.03)个、(15.3±6.83)个及(4.79±2.41)个;与ISO模型组比较,金丝桃苷组及自噬抑制组自噬体数显著下降(P<0.05)。结论 金丝桃苷能改善心力衰竭大鼠的心脏功能,其作用机制可能是通过抑制慢性心力衰竭大鼠心肌细胞自噬来实现。

Objectives To investigate the effect and mechanism of hyperoside on cardiac function in rats with heart failure. Methods SD rats were randomly divided into sham operation group(6 rats,normal saline 2 mL/kg each time),model group(6 rats,normal saline 2 m L/kg each time),treatment group(6 rats,hyperoside 30 mg/kg each time),administered by intraperitoneal injection once a day for 4 consecutive weeks. Rat cardiogram indicators were recorded by the cardiac color Doppler ultrasound. The pathological changes of myocardial tissue were observed by uranyl acetatelead nitrate double staining. The expressions of autophagy-related proteins were detected by Western blot. Newborn rat cardiomyocytes were used to establish cardiomyocyte injury models in vitro,which were divided into control group,isoproterenol(ISO)model group,hyperoside group and autophagy inhibition group. Autophagy of cardiomyocytes was detected by immunofluorescence staining. Results Compared with model group,the left ventricular ejection farction(LVEF)and left ventricular fractional shortening(LVFS)of the rats in treatment group significantly increased(P<0.05),and the interventricular septal diastole(IVSd),left ventricular posterior wall systole(LVPWs),interventricular septal systole(IVSs)and left ventricular posterior wall diastole(LVPWd)significantly decreased(P<0.05);the pathological changes of rat myocardium were significantly improved. Western blot results showed that the ratio of microtubule-associated protein 1 light chain 3(LC3)II/LC3I and the expression level of Beclin-1 protein in the myocardial tissue of rats in treatment group decreased(P<0.05),and the expression level of p62 protein increased(P<0.05). Immunofluorescence staining showed that the number of autophagosomes in the cells of control group,ISO model group,hyperoside group and autophagy inhibition group were 4.3±2.02,39.8±6.03,15.3±6.83,and 4.79±2.41 respectively. Compared with ISO model group,the number of autophagosomes in hyperoside group and autophagy inhibition group significantly decreased(P<0.05). Conclusions Hyperoside can improve cardiac function in rats with heart failure,and its mechanism may be achieved by inhibiting autophagy of cardiomyocytes in rats with chronic heart failure.