Alloush Jenna, Roof Steve R, Beck Eric X, Ziolo Mark T, Weisleder Noah
Indian J Biochem Biophys. 2013 Oct;50(5):428-35.
Membrane repair is a conserved cellular process, where intracellular vesicles translocate to sites of plasma membrane injury to actively reseal membrane disruptions. Such membrane disruptions commonly occur in the course of normal physiology, particularly in skeletal muscles due to repeated contraction producing small tears in the sarcolemmal membrane. Here, we investigated whether prolonged exercise could produce adaptive changes in expression levels of proteins associated with the membrane repair process, including mitsugumin 53/tripartite motif-containing protein 72 (MG53/TRIM72), dysferlin and caveolin-3 (cav3). Mice were exercised using a treadmill running protocol and protein levels were measured by immunoblotting. The specificity of the antibodies used was established by immunoblot testing of various tissue lysates from both mice and rats. We found that MG53/TRIM72 immunostaining on isolated mouse skeletal muscle fibers showed protein localization at sites of membrane disruption created by the isolation of these muscle fibers. However, no significant changes in the expression levels of the tested membrane repair proteins were observed following prolonged treadmill running for eight weeks (30 to 80 min/day). These findings suggest that any compensation occurring in the membrane repair process in skeletal muscle following prolonged exercise does not affect the expression levels of these three key membrane repair proteins.
膜修复是一个保守的细胞过程，在该过程中，细胞内囊泡转移至质膜损伤部位，以主动修复膜破裂。这种膜破裂在正常生理过程中普遍发生，尤其是在骨骼肌中，由于反复收缩会导致肌膜产生小裂口。在此，我们研究了长时间运动是否会使与膜修复过程相关的蛋白质表达水平产生适应性变化，这些蛋白质包括三宅蛋白53/含三联基序蛋白72（MG53/TRIM72）、dysferlin和小窝蛋白-3（cav3）。使用跑步机跑步方案对小鼠进行运动，并通过免疫印迹法测量蛋白质水平。通过对来自小鼠和大鼠的各种组织裂解物进行免疫印迹测试，确定了所用抗体的特异性。我们发现，对分离出的小鼠骨骼肌纤维进行MG53/TRIM72免疫染色时，蛋白质定位于因分离这些肌纤维而产生的膜破裂部位。然而，在进行为期八周（每天30至80分钟）的长时间跑步机跑步后，未观察到所测试的膜修复蛋白表达水平有显著变化。这些发现表明，长时间运动后骨骼肌膜修复过程中发生的任何代偿作用都不会影响这三种关键膜修复蛋白的表达水平。
