心功能衰竭大鼠模型心肌线粒体蛋白的差异表达分析

利用差异蛋白质组的方法识别心功能衰竭大鼠心肌代谢的异常 ,以期发现新的治疗靶点。对大鼠行冠状动脉左前降支结扎 ,术后 4周 ,左心室射血分数达 4 6 .4 %± 10 .9% ,成功建立心功能衰竭大鼠模型。实验动物分心功能衰竭组 (n =8)和对照组 (n =8) ,分别取左心室进行线粒体抽提。利用双向凝胶电泳技术显示差异蛋白的表达谱。再经胶内酶解 ,行质谱鉴定和蛋白数据库分析。结果发现 ,双向电泳显示 3个蛋白位点表达有显著差异 ,其中一条蛋白被证实为乙醛脱氢酶 2 ,它在心功能衰竭心肌中的表达显著下降。在心肌梗死后 3、7、14及 2 8天心肌乙醛脱氢酶 2mRNA的表达呈逐渐下降趋势。结果提示 ,在心功能衰竭大鼠的心肌线粒体中乙醛脱氢酶 2表达显著下调 ,而乙醛脱氢酶与硝酸甘油的转化有关。这为临床心功能衰竭患者使用硝酸甘油提供了很有价值的依据。

Proteomic Analysis of Myocardial Mitochondrial Protein Expression in Rats with Heart Failure

Aim To determine the metabolic changes in rats with heart failure by the application of proteomics, in order to discover possible new therapeutic targets. Methods Myocardial infarction model was established by left anterior descending coronary artery ligation. 4 weeks after operation, left ventricular ejection fraction was about 46.4%±10.9%. Then it was used as heart failure model. The rats were killed, left ventricular was cut off and the mitochondrial protein was extracted. Weight-age matched rats acted as control. The mitochondrial protein expression in the two groups was analyzed by two-dimensional gel electrophoresis. Results 3 protein spots altered significantly and they were exercised, washed and analyzed by using liquid chromatography-mass spectrometry. Aldehyde dehydrogenase-2 (ALDH-2) was identified using database comparision. Expression of ALDH-2 decreased remarkably in heart failure group compared with control. Furthermore, ALDH-2 mRNA expression of rats was detected at 3, 7, 14 and 28 d after lactate dehydrogenase ligation, which decreased gradually after operation as a result. Conclusions Mitochondrial ALDH has recently been identified as the enzyme that convert nitroglycerin into nitrate. The decreased expression of ALDH-2 in rats with heart failure may provide a clue for nitroglycerin tolerance in patients with heart failure.