慢性心力衰竭合并骨骼肌萎缩大鼠模型的建立与评价

Establishment and Evaluation of Rat Model of Chronic Heart Failure Combined with Skeletal Muscle Atrophy ZHANG Meisha,SU Weijie,WANG Yong,LA Xiaojin,CHENG Shunsheng,LI Xiaolong,CHANG Hong

目的:探讨慢性心力衰竭合并骨骼肌萎缩模型建立方法,通过观察骨骼肌组织形态学和涉及萎缩相关的指标,探讨慢性心力衰竭合并骨骼肌萎缩涉及的分子靶点。方法:通过结扎大鼠左侧冠状动脉前降支的方法来建立大鼠慢性心力衰竭模型。术后3 d进行心电图检测。术后饲养12周,检测大鼠心脏射血分数(EF)和血清N末端脑钠肽前体(NT-proBNP)浓度,观察心脏大体结构和苏木精-伊红(HE)染色后组织形态,确定心力衰竭模型是否复制成功。同时测量大鼠抓力、腓肠肌重量,观察腓肠肌的大体结构和HE染色后组织形态,确定大鼠慢性心力衰竭合并骨骼肌萎缩模型成功建立。应用蛋白免疫印迹法(Western Blot)检测腓肠肌组织中肌球蛋白重链(MyHC)、肌萎缩Fbox-1蛋白(Atrogin-1)、肌肉环指蛋白-1(MuRF-1)、叉头转录因子1(FOXO1)蛋白表达。结果:与假手术组相比,模型组心电图出现病理性Q波,心脏EF明显下降(P<0.01),血清NT-proBNP浓度明显升高(P<0.01),心脏体积变大而且水肿,左心室前壁明显凹陷,HE染色观察到心肌组织的排列很不规则;大鼠腓肠肌组织疏松,颜色偏暗淡,抓力和腓肠肌重量下降(P<0.01),肌纤维横截面积明显缩小(P<0.01)。Western Blot检测显示,与假手术组比较,模型组大鼠萎缩相关蛋白Atrogin-1、MuRF-1和FOXO1表达明显升高(P<0.05),而MyHC蛋白表达下降(P<0.05)。结论:FOXO1-Atrogin-1/MuRF-1通路在慢性心力衰竭合并骨骼肌萎缩中发挥重要作用,该模型的建立为临床防治此类疾病提供了实验基础。

Objective:To explore the establishment method of rat model of chronic heart failure combined with skeletal muscle atrophy,and to investigate the molecular targets by observing the histomorphology of skeletal muscle and indicators related to skeletal muscle atrophy.Methods:The anterior descending of left coronary artery was ligated to establish the rat model of chronic heart failure.Electrocardiogram was performed 3 days after surgery.After 12 weeks of feeding,in order to determine whether the heart failure model of rat was successfully replicated,the cardiac ejection fraction(EF)and serum NT-proBNP concentration were detected,and the structure and histological morphology of heart were observed after hematoxylin-eosin(HE)staining.Meanwhile,the grip strength and gastrocnemius muscle weight were measured,gastrocnemius muscle structure and histological morphology after HE staining were observed to determine whether the model of chronic heart failure combined with skeletal muscle atrophy in rat was successful establishment.Western Blot was used to detect the protein expressions of myosin heavy chain(MyHC),Atrogin-1,muscle ring finger protein-1(MuRF1),and forkhead transcription factors of O class1(FOXO1).Results:Compared with sham operation group,data in model group showed as follows.Pathological Q waves were observed in electrocardiogram,cardiac ejection fraction was significantly decreased(P<0.01),NT-proBNP concentration was increased(P<0.01).The rat heart was enlarged,accompanied with edema,and the anterior wall of the left ventricle was significantly sunken.HE staining data showed that myocardial tissues were irregular arrangement.Gastrocnemius tissue looked dull and felt loose.The grip strength,the weight of gastrocnemius,and the cross-sectional area of muscle fiber were significantly decreased(P<0.01).Western Blot indicated that atrophy related protein expressions of Atrogin-1,MurF-1,and FOXO1 were significantly elevated,while MyHC expression was decreased(P<0.05).Conclusions:FOXO1-Atrogin-1/MuRF-1 pathway plays an important role in chronic heart failure combined with skeletal muscle atrophy.The establishment of this model provides an experimental basis for clinical prevention and treatment of chronic heart failure combined with skeletal muscle atrophy.