线粒体移动相关基因miro1在急性运动中的表达特征

Expression of Mitochondrial Motility-related Gene miro1 during an Acute Bout of Prolonged Exercise

目的:探讨在急性运动中骨骼肌线粒体能量代谢与线粒体移动相关基因miro1的表达变化特征。方法:以C57 BL/6小鼠一次中等强度负荷跑台运动(0°,13m/min)为实验模型,将小鼠随机分为5组:安静对照组、运动30min、60min、90min、120min组,分别测定骨骼肌线粒体呼吸控制比(RCR),ATP合成酶活性、骨骼肌H2O2生成量,并观察运动中骨骼肌miro1 mRNA表达变化。结果:(1)120分钟急性运动过程中miro1mRNA表达均较安静组显著升高,其中E30、E60、E90、E120组分别较安静组增高32.8%、107.6%、63.8%及44.8%;(2)运动中各时间点骨骼肌H2O2均较安静组显著升高,E30～E120组分别较安静组升高22.1%、26.7%、37.6%、33.7%;(3)E30组ATP合成酶活性与安静组比较明显增加,其余各组无明显变化;整个运动过程中线粒体呼吸控制比无显著变化。结论:急性运动中骨骼肌miro1 mRNA表达较安静时显著增加,可能利于促进线粒体呼吸和ATP合成,以应对细胞能量需求。

Objective The purpose of this study was to investigate the expression of mitochondrial motility-related gene miro1 and mitochondrial energy metabolism during an acute bout of prolonged exercise.Methods C57 BL/6 mice underwent a moderate intensity treadmill running with the slope of 0° and at the speed of 13m/min,and they were randomly divided into 5 groupsr：esting group（R）,exercise groups running for 30min（E30）,60min（E60）,90min（E90）and 120min（E120）r,espectively.Respiratory control index and ATP synthesis activity in isolated mitochondria were detected.Skeletal muscle H2O2 concentration,mirol mRNA expressions were also measured.Results（1）miro1 mRNA contents were significantly increased in groups E30 to E120,as compared with the group R;and mirol mRNA expression increased 32.8%,107.6%,63.8% and 44.8% respectively in groups E30 to E120.（2）H2O2 contents of skeletal muscle were clearly increased in group s E30 to E120.（3）ATP synthesis activity elevated at 30 min of exercise and returned to the baseline thereafter,whereas respiratory control index without remarkable change in groups E30 to E120.Conclusion Muscular miro1 mRNA expression significantly increased during 120min of exercise as compared with the resting status and thus facilitated the mitochondrial respiratory and ATP synthesis for matching the energy demand during exercise.