【摘要】 目的探讨哈巴俄苷对急性心肌梗死(AMI)模型小鼠心肌结构及kelch样ECH关联蛋白1(Keap1)/核因子E2相关因子2(Nrf2)通路的影响。方法取C57BL/6 J小鼠12只作为空白组(A组);另取48只小鼠结扎左冠状动脉,建立AMI模型,将建模成功的40只小鼠随机分为模型组(B组),阳性对照组(C组,氯吡格雷30 mg/kg),哈巴俄苷低剂量组(D1组,20 mg/kg)和高剂量组(D2组,40 mg/kg),各10只。C组、D1组、D2组小鼠灌胃相应药物,A组、B组小鼠灌胃等量生理盐水,均连续给药4周。试验结束后,检测小鼠超声心动指标[左心室舒张末期内径(LVEDd)、左心室收缩末期内径(LVEDs)、短轴缩短分数(FS)、射血分数(EF)],采用2,3,5-三苯基四氯化四氮唑(TTC)染色法检测心肌梗死面积,采用反转录-聚合酶链式(RT-PCR)法及蛋白质免疫印迹(Western blot)法测定心肌Keap1和Nrf2基因及蛋白表达的水平。结果与A组比较,B组小鼠的FS、EF及心肌Keap1、Nrf2 mRNA和蛋白表达水平均显著降低,LVEDd、LVEDs、心肌梗死面积百分比及心/体比水平均显著升高(P <0.05);与B组比较,C组、D1组、D2组小鼠的FS、EF及心肌Keap1、Nrf2mRNA和蛋白表达水平均显著升高,LVEDd、LVEDs、心肌梗死面积百分比及心/体比水平均显著降低(P <0.05);与C组比较,D1组小鼠的FS、EF及心肌Keap1、Nrf2 mRNA和蛋白表达水平均显著降低,LVEDd、LVEDs、心肌梗死面积百分比及心/体比水平均显著升高(P <0.05),D2组上述指标的差异均无统计学意义(P>0.05);与D1组比较,D2组小鼠的FS、EF及心肌Keap1、Nrf2 mRNA和蛋白表达水平均显著升高,LVEDd、LVEDs、心肌梗死面积百分比及心/体比水平均显著降低(P <0.05)。结果哈巴俄苷能改善AMI模型小鼠的心功能,减少心肌梗死面积,其作用机制可能与哈巴俄苷能促进小鼠心肌梗死区域Keap1和Nrf2 mRNA及蛋白表达,进而激活Keap1/Nrf2通路有关。更多还原

【Abstract】 Objective To investigate the effect of harpagoside on myocardial structure and kelch-like ECH-associated protein 1( Keap1)/nuclear factor E2-related factor 2( Nrf2) pathway in model mice with acute myocardial infarction( AMI). Methods A total of12 C57 BL/6 J mice were selected as the blank group( group A),another 48 mice were ligated left coronary artery to establish AMI model. A total of 40 model mice were successfully established and randomly divided into the model group( group B),positive control group( group C,30 mg/kg of clopidogrel),harpagoside low-dose group( group D1,20 mg/kg),harpagoside high-dose group( group D2,40 mg/kg),10 mice in each group. The mice in groups C,D1 and D2 were given the corresponding drugs by intragastric administration,while the mice in groups A and B were given the same volume of normal saline by intragastric administration. All the mice were continuously given drugs for four weeks. At the end of the experiment,the echocardiographic indexes [ left ventricular end-diastolic diameter( LVEDd),left ventricular end-systolic diameter( LVEDs),short-axis fractional shortening( FS),ejection fraction( EF) ] were detected,the infarct size was detected by 2,3,5-triphenyltetrazolium chloride( TTC) staining,and the Keap1 and Nrf2 gene and protein expression levels were measured by the reverse transcription-polymerase chain reaction( RT-PCR) and Western blot. Results Compared with those in group A,the FS and EF levels,myocardial Keap1 and Nrf2 mRNA and protein expression levels in group B were significantly decreased,while the LVEDd,LVEDs,percentage of infarct size and heart/body ratio in group B were significantly increased( P < 0. 05).Compared with those in group B,the FS and EF levels,myocardial Keap1 and Nrf2 mRNA and protein expression levels in groups C,D1 and D2 were significantly increased,while the LVEDd,LVEDs,percentage of infarct size and heart/body ratio in groups C,D1 and D2 were significantly decreased( P < 0. 05). Compared with those in group C,the FS and EF levels,myocardial Keap1 and Nrf2 mRNA and protein expression levels in group D1 were significantly decreased,while the LVEDd,LVEDs,percentage of infarct size and heart/body ratio in group D1 were significantly increased( P < 0. 05). Compared with those in group C,there was no significant difference in the above indexes in group D2( P > 0. 05). Compared with those in group D1,the of FS and EF levels,myocardial Keap1 and Nrf2 mRNA and protein expression levels in group D2 were significantly increased,while the LVEDd,LVEDs,percentage of infarct size and heart/body ratio in group D2 were significantly decreased( P < 0. 05). Conclusion Harpagoside can improve cardiac function and reduce the infarct size of AMI mice,and its mechanism may be related to harpagoside promoting the Keap1 and Nrf2 mRNA and protein expression levels in the infarct area of AMI mice,thereby activating the Keap1/Nrf2 pathway.更多还原