老年大鼠心肌线粒体的比较蛋白质组学研究

Comparative proteomics of myocardial mitochondrial proteins in aging rats

目的:筛查心肌线粒体中与衰老相关的蛋白质。方法:分离成年组(10周)和老年组(12月)雄性SD大鼠心肌线粒体,抽提心肌线粒体蛋白质行双向凝胶电泳,应用MALD I-TOF-MS和数据库搜索鉴定图像分析出的差异蛋白点,同时进行了心肌组织ATP含量的检测。结果:图像分析示84个心肌线粒体蛋白表达发生改变,质谱鉴定了15个差异点。老年组肌酸激酶、硫氧还原蛋白过氧化物酶2、Tu翻译延长因子、异柠檬酸脱氢酶4个蛋白表达上调,琥珀酸脱氢酶、苹果酸脱氢酶、乌头酸水合酶、NADH脱氢酶、ATP合酶H+转运装置、ATP合酶β链、热休克蛋白60、葡萄糖调节蛋白78、proh ib itin、乙醛脱氢酶2、电压依赖型阴离子通道11个蛋白表达下调。老年组心肌组织ATP含量下降(P<0.01)。结论:通过具有高度分辨率和高度重复性的双向凝胶电泳图谱鉴定了SD大鼠心肌线粒体中在老年组差异表达的蛋白质,这些差异蛋白为深入理解衰老的分子机制提供了有益的线索,差异蛋白的功能留待以后进一步研究。

AIM： To identify the proteins related to aging in the mitochondria of the heart. METHODS： Mitochondria were isolated from the hearts of adult （ 10 - week） and old （ 12 - month） rats （ n = 3）. Total proteins extracted from the mitochondria were applied to the two - dimensional gel electrophoresis. The differentially expressed protein spots evaluated by a software were subjected to in - gel digestion, and analyzed by the matrix - assisted laser desorption ionization time - of- flight mass spectrometry （ MALDI - TOF - MS）. ATP content in the heart was also measured. RESULTS ： Eighty - four differentially expressed protein spots were observed, and fifteen of them were analyzed by MALDI - TOF - MS. Four proteins including creatine kinase, peroxiredoxin 2, Tu translation elongation factor and isocitrate dehydrogenase were up - regulated and 11 proteins including succinate dehydrogenase, malate dehydrogenase, aconitate hydratase, NADH dehydrogenase, ATP synthase H^＋ transporting, ATP synthase beta chain, heat shock protein 60, glucose - regulated protein 78, prohibitin, Aldehyde dehydrogenase 2 and voltage - dependent anion channel exhibited down - regulation in the aging group compared to the adult one. ATP content in the heart of old rats was significantly reduced as compared to that in adult rats （n = 5, P 〈 0. 01 ）. CONCLUSION： Significant changes in the mitochondrial protein expression in the aging heart were identified by the 2 - DE electrophoretogram with high resolution and reproducibility. The functions of these identiffed proteins need to be further investigated.