Reitzner Stefan M, Norrbom Jessica, Sundberg Carl Johan, Gidlund Eva-Karin
Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Department of Learning, Informatics, Management and Ethics, Karolinska Institutet, Stockholm, Sweden.
Physiol Rep. 2018 Mar;6(5). doi: 10.14814/phy2.13624.
The striated activator of rho-signaling (STARS) protein acts as a link between external stimuli and exercise adaptation such as muscle hypertrophy. However, the acute and long-term adaptational response of STARS is still unclear. This study aimed at investigating the acute and long-term endurance training response on the mRNA and protein expression of STARS and its related upstream and downstream factors in human skeletal muscle. mRNA and protein levels of STARS and related factors were assessed in skeletal muscle of healthy young men and women following an acute bout of endurance exercise (n = 15) or 12 weeks of one-legged training (n = 23). Muscle biopsies were obtained before (acute and long-term), at 30 min, 2, and 6 h following acute exercise, and at 24 h following both acute exercise and long-term training. Following acute exercise, STARS mRNA was significantly elevated 3.9-fold at 30 min returning back to baseline 24 h after exercise. STARS protein levels were numerically but nonsignificantly increased 7.2-fold at 24 h. No changes in STARS or ERRα mRNA or STARS protein expression were seen following long-term training. PGC-1α mRNA increased 1.7-fold following long-term training. MRTF-A mRNA was increased both following acute exercise and long-term training, in contrast to SRF mRNA and protein which did not change. STARS mRNA is acutely upregulated with exercise, but there is no cumulative effect to long-term training as seen in PGC-1α mRNA expression. Exercise intensity might play a role in manifestation of protein expression, suggesting a more complex regulation of STARS.
Rho信号通路的横纹肌激活蛋白（STARS）作为外部刺激与运动适应性（如肌肉肥大）之间的联系。然而，STARS的急性和长期适应性反应仍不清楚。本研究旨在调查人类骨骼肌中STARS及其相关上下游因子的mRNA和蛋白表达对急性和长期耐力训练的反应。在健康年轻男性和女性进行一次急性耐力运动（n = 15）或12周单腿训练（n = 23）后，评估骨骼肌中STARS及相关因子的mRNA和蛋白水平。在急性运动前（急性和长期）、急性运动后30分钟、2小时和6小时以及急性运动和长期训练后24小时获取肌肉活检样本。急性运动后，STARS mRNA在30分钟时显著升高3.9倍，运动后24小时恢复至基线水平。STARS蛋白水平在24小时时在数值上增加了7.2倍，但无统计学意义。长期训练后，STARS或ERRα mRNA以及STARS蛋白表达未见变化。长期训练后，PGC-1α mRNA增加了1.7倍。与未变化的SRF mRNA和蛋白相反，急性运动和长期训练后MRTF-A mRNA均增加。STARS mRNA在运动时急性上调，但与PGC-1α mRNA表达不同，对长期训练没有累积效应。运动强度可能在蛋白表达的表现中起作用，提示对STARS存在更复杂的调控。
