“解偶联蛋白库”参与急性运动中骨骼肌线粒体解偶联蛋白3的迅速表达  

UCPs Pool Is Involved in the Rapidly Up-regulated UCP3 Expression in Muscular Mitochondria during Acute Exercise

作　　者：屈金亭[1] 薄海[1] 姜宁[1] 马国栋[1] 曹东宁[1] 文立[1] 刘树森[2] 张勇[1] 

机构地区：[1]天津体育学院运动医学研究所运动人体科学系 [2]中国科学院动物研究所生物膜与膜生物工程国家重点实验室,北京100101

出　　处：《中国运动医学杂志》2007年第6期657-662,共6页Chinese Journal of Sports Medicine

基　　金：国家自然科学基金(No.30270638和30470837)共同资助

摘　　要：目的:研究急性运动中和运动后,骨骼肌线粒体活性氧(ROS)生成与解偶联蛋白3(UCP3)表达的相互关系,探讨骨骼肌胞浆中解偶联蛋白库的作用。方法:采用修正的SD大鼠三级递增负荷跑台运动模型,分别选取安静态、运动45、90、120、150min和运动后3、6、12、24h为实验观察点(time course),荧光法测定骨骼肌线粒体ROS生成;荧光定量PCR测定UCP3 mRNA;蛋白印迹法测定骨骼肌和线粒体UCP3蛋白表达;免疫荧光分析检测骨骼肌线粒体外是否存在UCP3蛋白。结果:(1)急性运动中及运动后UCP3 mRNA含量和线粒体UCP3蛋白水平均呈先上升后下降的变化趋势:UCP3 mRNA含量在运动45min时显著高于安静态(P<0.01),并持续增高到150min时。虽然在运动后明显下降,但仍显著高于安静态(P<0.05);线粒体UCP3蛋白含量在运动120min和150min时显著高于安静态(P<0.001),而骨骼肌UCP3蛋白含量各时间点均未见显著性差异(P>0.05);(2)免疫荧光分析显示,安静态胞浆内存在大量UCP3蛋白,运动120分钟时明显减少;(3)急性运动中及运动后骨骼肌线粒体ROS生成呈先上升后下降的变化趋势:运动45min开始显著升高(P<0.05),并持续升高至运动120min(P<0.001),150min时有所下降,但仍显著高于安静态(P<0.01);运动后3、6、12、24hROS生成均高于安静态,12、24h显著高于安静态(P<0.05)。结论:骨骼肌细胞胞浆内存在"UCP3蛋白库",可在运动应激条件下快速动员装载入线粒体,发挥运动抗氧化的快速应答效应。Aims The present study is to explore the implications of the skeletal muscles mitochondrial ROS generation and UCP3 expression during and after acute exercise. Methods According to the Bedford＇s protocol, SD rats were forced to run on the treadmill and were sacrificed at rest, and 45min, 90min, 120min and 150min during exercise, and 3h, 6h, 12h and 24h after exercise. ROS generation was measured by DCFH-DA. Expression of UCP3 mRNA in muscle homogenate was measured by RT--PCR, and its protein in mitochondria and muscle was measured by Western blotting. Immunofluorescence was used to measure UCP3 protein in the skeletal muscle cellular cytoplasm （outside the mitochondria）. Results （1） As compared with before exercise, there were remarkably higher levels of UCP3 mRNA at the point of 45min, 90min, 120min and 150min during exercise and 3, 6, 12, 24 hour after exercise （P〈0.05）; and also remarkably higher levels of the mitochondrial UCP3 protein content at the point of 120min and 150min during exercise （P〈0. 001）. There was no difference in UCP3 protein of skeletal muscle tissue at all time points. （2） There existed an UCP3 pool in skeletal muscle cellular cytoplasm （outside the mitochondria） before exercise and an acute bout of exercise for 120min decreased UCP3 content in this pool significantly. （3） ROS generation in mitochondria of skeletal muscle at 45min during exercise increased significantly （P〈0.05） ; and reached to the peak at 120min during exercise （P〈0. 001）, thereafter began to decline, but still remained at higher level at 150min during exercise as compared with that at rest （P〈0.01）. ROS level 12h and 24h after exercise was still significantly higher than that at rest （P〈0.05）. Conclusions Our findings suggested that there is a UCP3 pool in skeletal muscle cellular cytoplasm. UCP3 in this pool can be activated rapidly by acute exercise and participate in ＂early response＂ of mitochondrial antioxidant defense.

关 键 词：急性运动 骨骼肌线粒体 ROS UCP3蛋白库 

分 类 号：R87[医药卫生—运动医学]