【摘要】 目的：探讨Ⅲ型纤连蛋白域蛋白5(FNDC5)过表达对老年慢性心力衰竭（CHF）大鼠氧化应激、细胞凋亡及腺苷酸活化蛋白激酶（AMPK）/沉默信息调控因子1(SIRT1)信号通路的影响。方法：以腹腔注射阿霉素建立老年CHF大鼠模型，将造模成功的老年CHF大鼠随机分为模型组（CHF组）、空载体慢病毒组（Lv-NC组）、FNDC5过表达慢病毒组（Lv-FNDC5组）、FNDC5过表达慢病毒+AMPK抑制剂Compound C组（Lv-FNDC5+Compound C组），每组10只。以正常饲养的10只老年大鼠作为空白对照组（Control组）。采用超声心动图检测心功能指标[左室射血分数（LVEF）、左室短轴缩短率（LVFS）、左室收缩末期内径（LVESD）、左室舒张末期内径（LVEDD）]；苏木精-伊红（HE）染色观察心肌组织病理形态；试剂盒法检测心肌组织氧化应激指标[超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）、丙二醛（MDA）]水平；脱氧核糖核苷酸末端转移酶介导的缺口末端标记法（TUNEL）染色法检测细胞凋亡；实时荧光定量聚合酶链式反应（q RT-PCR）检测FNDC5基因表达；蛋白免疫印迹（Western Blot）法检测FNDC5蛋白、AMPK/SIRT1信号通路蛋白表达。结果：与Control组比较，CHF组大鼠心肌组织可见明显的间质水肿和局灶性细胞质空泡，存在大量炎性细胞浸润；与CHF组比较，Lv-FNDC5组大鼠心肌组织病理学损伤明显减轻；与Lv-FNDC5组比较，Lv-FNDC5+Compound C组大鼠心肌组织病理学损伤较明显加重。与Control组比较，CHF组大鼠LVEF、LVFS水平降低（P<0.05）,LVESD、LVEDD水平升高（P<0.05）；心肌组织中SOD和GSH-Px活性降低（P<0.05）,MDA含量、细胞凋亡率升高（P<0.05）；心肌组织中FNDC5 mRNA和蛋白相对表达量、p-AMPK/AMPK比值、SIRT1蛋白相对表达量降低（P<0.05）。与CHF组比较，Lv-FNDC5组大鼠LVEF、LVFS水平升高（P<0.05）,LVESD、LVEDD水平降低（P<0.05）；心肌组织中SOD和GSH-Px活性升高（P<0.05）,MDA含量、细胞凋亡率降低（P<0.05）；心肌组织中FNDC5 mRNA和蛋白相对表达量、p-AMPK/AMPK比值、SIRT1蛋白相对表达量升高（P<0.05）。与Lv-FNDC5组比较，Lv-FNDC5+Compound C组大鼠LVEF、LVFS水平降低（P<0.05）,LVESD、LVEDD水平升高（P<0.05）；心肌组织中SOD和GSH-Px活性降低（P<0.05）,MDA含量、细胞凋亡率升高（P<0.05）；心肌组织中p-AMPK/AMPK比值、SIRT1蛋白相对表达量降低（P<0.05）。结论：FNDC5过表达通过减轻氧化应激和细胞凋亡改善老年CHF大鼠心功能，其作用机制可能与激活AMPK/SIRT1信号通路有关。更多还原

【Abstract】 Objective:To investigate the effects of type Ⅲ fibronectin domain protein 5(FNDC5) overexpression on oxidative stress,apoptosis,and adenylate-activated protein kinase(AMPK)/silencing information regulatory factor 1(SIRT1) signaling pathway in aged rats with chronic heart failure(CHF).Methods:The elderly CHF rat model was established by intra peritoneal injection of Adriamycin,the successful constructed elderly CHF rats were randomly divided into model group(CHF group),empty lentivirus group(Lv-NC group),FNDC5 overexpression lentivirus group(Lv-FNDC5 group),FNDC5 overexpression lentivirus+AMPK inhibitor Compound C group(Lv-FNDC5+Compound C group),with 10 rats in each group.Ten normal aged rats were used as blank control group(Control group).Cardiac function para meters [left ventricular ejection fraction(LVEF),left ventricular fraction shortening(LVFS),left ventricular end-systolic diameter(LVESD),left ventricular end-diastolic diameter(LVEDD)] were detected by echocardiography.The pathological morphology of myocardium was observed by hematoxylin-eosin(HE) staining.The levels of oxidative stress indexes[superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),malondialdehyde(MDA)] in myocardial tissue were detected by kit method.The apoptosis was detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling(TUNEL) staining.The expression of FNDC5 gene was detected by qRT-PCR;The expression of FNDC5 protein and AMPK/SIRT1 signaling pathway protein were detected by Western Blot.Results:Compared with the Control group,the myocardial tissue of CHF group showed obvious interstitial edema and focal cytoplasmic vacuoles,with a large number of inflammatory cell infiltration.Compared with the CHF group,the pathological damage of myocardium in the Lv-FNDC5group was significantly alleviated.Compared with the Lv-FNDC5 group,the pathological damage of myocardium in the Lv-FNDC5+Compound C group was significantly aggravated.Compared with the Control group,the levels of LVEF and LVFS in CHF group were decreased,while the levels of LVESD and LVEDD were increased(P<0.05);The activity of SOD and GSH-Px in myocardial tissue were decreased,while the content of MDA and apoptosis rate were increased(P<0.05);The relative expression of FNDC5 mRNA and protein,p-AMPK/AMPK ratio,and the relative expression of SIRT1 protein in myocardial tissue were decreased(P<0.05).Compared with the CHF group,the levels of LVEF and LVFS in Lv-FNDC5 group were increased,while the levels of LVESD and LVEDD were decreased(P<0.05);The activity of SOD and GSH-Px in myocardial tissue were increased,while the content of MDA and apoptosis rate were decreased(P<0.05);The relative expression of FNDC5 mRNA and protein,p-AMPK/AMPK ratio,and the relative expression of SIRT1 protein in myocardial tissue were increased(P<0.05).Compared with the Lv-FNDC5 group,the levels of LVEF and LVFS in Lv-FNDC5+Compound C group were decreased,while the levels of LVESD and LVEDD were increased(P<0.05);The activity of SOD and GSH-Px in myocardial tissue were decreased,while the content of MDA and apoptosis rate were increased(P<0.05);The ratio of p-AMPK/AMPK and the relative expression of SIRT1 protein in myocardial tissue were decreased(P<0.05).Conclusion:FNDC5 overexpression improves cardiac function in elderly CHF rats by reducing oxidative stress and apoptosis,and its mechanism may be related to the activation of AMPK/SIRT1 signaling pathway.更多还原