金丝桃苷对主动脉弓缩窄所致的小鼠心肌肥厚的保护作用

The Protective Effects of Hyperoside on Cardiac Hypertrophy Induced by Transverse Aortic Constriction

目的:研究金丝桃苷(hyperoside, HYP)对主动脉弓缩窄所致小鼠病理性心肌肥厚的保护作用及其机制。方法:将32只C57BL/6J小鼠随机分为4组:假手术(Sham)组、单纯给药(HYP)组、主动脉弓缩窄(TAC)组及主动脉弓缩窄给药(TAC+HYP)组,每组8只。采用经典的主动脉弓缩窄术建立小鼠压力负荷型心肌肥厚模型。TAC术后4周,超声心动图仪检测心脏功能;左心室导管监测血流动力学指标;分离心脏、肺脏和胫骨计算心/体比、肺/体比和心/胫比,HE染色计算心肌细胞平均横截面积,Masson染色观察心肌纤维化程度,试剂盒检测心肌组织中SOD的活性和MDA的含量;DHE荧光探针检测心肌组织ROS生成量;Western blotting检测SIRT3、NOX 4、Collagen-1和Collagen-3蛋白表达,实时定量PCR检测SIRT3、ANP、α-MHC、β-MHC的m RNA表达情况。结果:与Sham组相比,TAC组小鼠的LVPWD值增加,LVSP和LVEDP值上升,LVEF、LVFS、E/A和±dp/dtmax值均降低;HM/BW、LW/BW和HW/TL值升高,心肌细胞横截面积增加;心肌组织胶原沉积加重;肥厚基因ANP的m RNA表达水平显著上升,α-MHC/β-MHC的比例倒置;心肌组织SOD活性降低,MDA和ROS生成量增加;SIRT3信号表达明显降低(均P<0.05)。给予HYP药物处理后,TAC+HYP组小鼠的心脏功能、血流动力学改变、心肌细胞肥厚程度、心肌组织纤维化和氧化应激水平均明显改善,并且心肌细胞SIRT3信号表达也显著增强(均P<0.05)。结论:HYP能够通过减轻心肌组织氧化应激损伤,抑制心肌纤维化进展,改善压力负荷引起的病理性心肌肥厚,且其作用机制可能与激活SIRT3信号有关。

Objective: To investigate whether hyperoside(HYP) treatment could ameliorate cardiac hypertrophy induced by transverse aortic constriction(TAC) and explore its protective mechanisms. Methods: Thirty-two C57 BL/6 mice were randomly divided into four groups(n=8 in each group): Sham, HYP group, TAC group, and TAC+ HYP group. TAC surgery was adopted to establish the pressure overload-induced cardiac hypertrophy model. Four weeks after TAC surgery, the cardiac function was detected by ultrasonic cardiograph. The hemodynamics indexes were monitored by left ventricular catheter. The ratios of heart weight/body weight(HW/BW),lung weight/body weight(LW/BW) and heart weight/tibia length(HW/TL) were calculated. The mean cross-sectional area of cardiomyocytes was calculated by HE staining. The degree of myocardial fibrosis was observed by Masson staining. The contents of superoxide dismutase(SOD) and malondialdehyde(MDA) in myocardium were estimated by special kits. The production of reactive oxygen species(ROS) was detected by DHE fluorescence probe. The protein expressions of SIRT3, NOX 4, Collagen-1 and Collagen-3 were detected by western blotting. The expressions of SIRT3, ANP, α-MHC and β-MHC m RNA was detected by real-time PCR(RT-PCR). Results: Compared with the Sham group, the TAC group had increased LVPWD, LVSP and LVEDP, decreased LVEF、LVFS, E/A and ± dp/dtmax. The ratio of HM/BW, LW/BW and HW/TL were also raised, accompanied by an increased cardiomyocyte cross-sectional area. Besides, collagen deposition was exacerbated, hypertrophy-related gene expression was increased and the ratio ofα-MHC/β-MHC was inverted in the TAC group. In addition, the TAC group had reduced SOD activity and promoted MDA and ROS production, along with an decreased the expression of SIRT3 signaling(P<0.05). After HYP treatment, the cardiac function,hemodynamic changes, cardiomyocyte hypertrophy, myocardial fibrosis and oxidative stress levels in TAC+HYP group were all significantly improved, and the expression of SIRT3 signaling was also markedly enhanced(P<0.05). Conclusion: THC treatment could effectively attenuate pressure overload-induced pathological cardiac hypertrophy through alleviating oxidative stress in myocardium and inhibiting the progression of myocardial fibrosis, which may be associated with the activation of SIRT3 signaling.