骨骼肌小热休克蛋白在离心运动后的表达

背景:研究证明离心方式的训练可使骨骼肌产生保护作用,避免离心运动引起的损伤,但是机械负荷引起的小热休克蛋白的保护作用至今却少有报道。目的:观察骨骼肌小热休克蛋白家族中αB-晶体蛋白在离心运动后的表达,以此探讨机械负荷诱导的小热休克蛋白对骨骼肌细胞的保护作用机制。方法:将Wistar大鼠随机分为安静对照组和运动训练组。运动训练组使用动物跑台进行6周间歇性离心运动训练,每周训练5d,安静对照组正常喂养。训练6周休息48h后,安静对照组与运动训练组随机选出6只大鼠做1次性大负荷离心运动。观察两组血清肌酸激酶变化;蛋白免疫印迹法检测两组腓肠肌αB-晶体蛋白含量变化,用免疫荧光组织化学法分析两组腓肠肌αB-晶体蛋白亚细胞表达特征。结果与结论:大负荷离心运动后,安静对照组血清肌酸激酶与运动前相比显著增高(P<0.05),说明骨骼肌细胞出现严重的损伤,而运动训练组这种损伤不明显。蛋白免疫印迹结果表明,运动训练组做一次性大负荷离心运动后αB-晶体蛋白表达水平比安静对照组增加(P<0.05)。从免疫荧光组化切片可见,αB-晶体蛋白在细胞内发生了移位变化,从胞浆移位于Z盘和细胞膜。提示αB-晶体蛋白在离心运动训练后表达增多,并通过移位于肌细胞Z-盘和细胞膜发挥对骨骼肌细胞的保护作用。

Expression of small heat shock protein in skeletal muscle following eccentric training

BACKGROUND:Studies have proved that eccentric way of training can make the skeletal muscles generate protective effect and avoid damages caused by eccentric exercise.Up to now,there is little report about protective effect on small heat shock protein caused by mechanical load.OBJECTIVE:To clarify the protection mechanism on skeletal muscle cells caused by the small heat shock protein induced by the mechanical loading.METHODS:Wistar rats were randomly assigned into a sedentary control group,and an exercise training group.In the exercise training group,we use treadmill to train rats by intermittent eccentric exercise,5 days every week.While for those in the sedentary control group,we feed them normally.Forty-eight hours after the end of the 6 weeks training period,6 rats from each group were also submitted to one-time big load eccentric exercise.Then we analyzed the levels of serum creatine kinase.Western bloting was used to analyze the expression of αB-crystallin.Immunofluorence was used to examine αB-crystallin expression characteristics in muscle cells.RESULTS AND CONCLUSION:After one-time eccentric exercise,rats’ serum creatine kinase in the sedentary control group was significantly higher than before exercise(P < 0.05),while serum creatine kinase was not significantly changed in the sedentary control group.Western-blotting results showed that,compared with the sedentary control group,there was an obvious increase of αB-crystallin protein levels in the exercise training group after one-time big load(P < 0.05).From immunofluorescence slice,αB-crystallin had translocated to sites at the Z-disk and cell membrane.Result suggests that the protein content of αB-crystallin is increased after eccentric exercise training and the increased αB-crystallin play protection effects through translocated to Z-dise and cell membrane.