心肌肌浆网Ca^2＋-ATP酶过表达对慢性缺血性心力衰竭小型猪心功能的改善作用  

Cardiac function improved by sarcoplasmic reticulum Ca^(2+)-ATPase overexpression in a heart failure model induced by chronic myocardial ischemia

作　　者：辛伟[1] 李小鹰[1] 鲁晓春[1] 牛堃[1] 蔡吉梅[1] 

机构地区：[1]解放军总医院老年心血管一科,北京100853

出　　处：《解放军医学杂志》2011年第4期347-351,共5页Medical Journal of Chinese People's Liberation Army

基　　金：国家重点基础研究发展计划(973计划)资助项目(2006CB503806,2007CB512004);国家自然科学基金资助项目(30600236,30770900)

摘　　要：目的研究心肌肌浆网Ca2+-ATP酶(SERCA2a)基因过表达对慢性缺血性心力衰竭(HF)小型猪心功能的改善作用。方法使用Ameroid缩窄环束扎小型猪前降支起始段,4周后行超声心动和血流动力学检查确认心功能下降,放免法测定血清炎性因子(TNF-α、IL-6)和神经体液因子(BNP、AngII、ET-1)的变化。将动物模型随机分为HF组、HF+EGFP组、HF+SERCA2a组,并设假手术组作为对照,每组各4只。HF+EGFP组和HF+SERCA2a组再次开胸,心肌组织内注射包含报告基因的rAAV1-EGFP和包含靶基因的rAAV1-SERCA2a各1ml(1×1012v.g/ml)。基因转导60d后,处死各组动物,行免疫组化和Western blotting检测SERCA2a在心肌中的表达情况;超声心动和血流动力学检测转导SERCA2a对心功能的影响,并用放免法检测上述炎性因子和神经体液因子的变化。结果成功建立小型猪慢性心肌缺血HF模型12只,Ameroid环植入4周后,超声心动和血流动力学数据提示模型组心脏舒缩功能显著下降(P<0.05),并伴有外周血上述炎性因子和神经体液因子的激活。基因转导后60d,SERCA2a蛋白在HF+SERCA2a组的表达量显著高于HF及HF+EGFP组(P<0.05),但与对照组比较无显著差异;其心功能参数LVEF、Ev/Av、±dp/dtmax较HF及HF+EGFP组显著增高(P<0.05),并伴随血清炎性因子和神经体液因子浓度的明显下降(P<0.05),提示心功能好转,心衰严重程度下降。结论过表达SERCA2a可改善慢性缺血性心力衰竭的心脏功能,可能成为慢性心肌缺血、心力衰竭治疗的潜在手段。Objective Chronic myocardial ischemia（CMI） has become an important cause of heart failure（HF）.The aim of present study was to examine the effects of Sarco-endoplasmic reticulum calcium ATPase（SERCA2a） gene transfer in HF model in large animal induced by CMI.Methods HF was reproduced in minipigs by ligating the initial segment of proximal left anterior descending（LAD） coronary artery with an ameroid constrictor to produce progressive vessel occlusion and ischemia.After confirmation of myocardial perfusion defect and cardiac function impairment by SPECT and echocardiography in the model,animals were divided into 4 groups： HF group;HF＋enhanced green fluorescent protein（EGFP） group;HF＋SERCA2a group;and sham operation group as control.rAAV1-EGFP and rAAV1-SERCA2a（1×1012 vg for each animal） were directly and intramyocardially injected to the animals of HF＋EGFP and HF＋SERCA2a groups.Sixty days after the gene transfer,the expression of SERCA2a at the protein level was examined by Western blotting and immunohistochemistry,the changes in cardiac function were determined by echocardiographic and hemodynamic analysis,and the changes in serum inflammatory and neuro-hormonal factors（including BNP,TNF-a,IL-6,ET-1 and Ang II） were determined by radioimmunoassay.Results Sixty days after gene transfer,LVEF,Ev/Av and ±dp/dtmax increased significantly（P〈0.05）,along with an increase of SERCA2a protein expression in the ischemic myocardium（P〈0.05）,accompanied by a significant decrease of inflammatory and neural-hormonal factors（P〈0.05） in HF＋SERCA2a group as compared with HF/HF＋EGFP group.Conclusions Overexpression of SERCA2a may significantly improve the cardiac function of the ischemic myocardium of HF model induced by CMI and reverse the activation of neural-hormonal factors,implying that it has a potential therapeutic significance in CMI related heart failure.

关 键 词：心力衰竭 基因疗法 钙转运ATP酶类 心肌缺血 

分 类 号：R541.62[医药卫生—心血管疾病]