大鼠股直肌去负荷萎缩及再负荷恢复过程中的蛋白表达差异

Differential Proteomic Analysis of Rat Rectus Femoris Undergoing Hindlimb Suspension

目的:研究骨骼肌蛋白质在去负荷萎缩及再负荷恢复过程中的变化。方法:24只SD大鼠随机等分为对照组、去负荷2周组和去负荷2周后自然恢复2周组。去负荷方式为尾部悬吊。采用2D电泳分析各组大鼠股直肌蛋白表达差异。结果:与对照组相比,去负荷2周组有21个蛋白发生显著变化。收缩蛋白如肌球蛋白轻链1、肌球蛋白调节轻链2、原肌球蛋白、原肌球蛋白表达下调,而肌球蛋白轻链3型及肌动蛋白表达上调;与糖酵解相关的蛋白(烯醇酶、甘油醛3-磷酸脱氢酶)及肌酸激酶M链表达上调;应激蛋白中有4种热休克蛋白(p20,Hsp27,Hsp 6,B-晶体蛋白)表达上调。恢复2周组有原肌球蛋白链、肌球蛋白轻链3型、肌球蛋白调节轻链2型、肌动蛋白、磷酸丙糖异构酶、-烯醇酶、肌酸激酶、B-晶体蛋白等恢复到对照组水平。结论:肌原纤维中降解酶、代谢调节酶的变化可能导致骨骼肌去负荷萎缩。

Objective The aim of the work was to identify the changes in skeletal muscle in the process of unloading and reloading.Methods Twenty four rats were divided into three groups：control group（C）,2-week unload group（UN） and 2-week reload group（RL）.Hindlimb suspension in group UN was performed for 2 weeks,and then release the suspension for another 2 weeks（group RL）.The changes in protein expression of rectus femoris were analyzed by 2D electrophoresis.Results As compared with the group C,we found 21 different expressions of proteins in group UL,among which contractile protein levels of myosin light chain 1（MLC1）,myosin regulatory light chain 2,tropomyosin α,b-chain,a-actin and MLC3 increased.Creatine kinase,and αB-crystallin returned to the control levels in group RL.Conclusion Muscle atrophy in group UL probably was caused by the changes in catabolic enzymes of myofibrilla and in enzymes of metabolic regulation.