Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia.
Pflugers Arch. 2013 Sep;465(9):1317-25. doi: 10.1007/s00424-013-1265-5. Epub 2013 Mar 23.
The striated muscle activator of Rho signaling (STARS) protein and members of its downstream signaling pathway, including myocardin-related transcription factor-A (MRTF-A) and SRF, are increased in response to prolonged resistance exercise training but also following a single bout of endurance cycling. The aim of the present study was to measure and compare the regulation of STARS, MRTF-A and SRF mRNA and protein following 10 weeks of endurance training (ET) versus resistance training (RT), as well as before and following a single bout of endurance (EE) versus resistance exercise (RE). Following prolonged training, STARS, MRTF-A and SRF mRNA levels were all increased by similar magnitude, irrespective of training type. In the training-habituated state, STARS mRNA increased following a single-bout RE when measured 2.5 and 5 h post-exercise and had returned to resting level by 22 h following exercise. MRTF-A and SRF mRNA levels were decreased by 2.5, 5, and 22 h following a single bout of RE and EE exercise when compared to their respective basal levels, with no significant difference seen between the groups at any of the time points. No changes in protein levels were observed following the two modes of exercise training or a single bout of exercise. This study demonstrates that the stress signals elicited by ET and RT result in a comparable regulation of members of the STARS pathway. In contrast, a single bout of EE and RE, performed in the trained state, elicit different responses. These observations suggest that in the trained state, the acute regulation of the STARS pathway following EE or RE may be responsible for exercise-specific muscle adaptations.
横纹肌 Rho 信号激活蛋白（STARS）及其下游信号通路成员，包括肌细胞增强因子 2A（MRTF-A）和血清反应因子（SRF），会因长时间的抗阻运动训练而增加，也会因单次耐力运动而增加。本研究旨在测量和比较 10 周耐力训练（ET）与抗阻训练（RT）后，以及单次耐力（EE）与抗阻运动（RE）前后 STARS、MRTF-A 和 SRF mRNA 和蛋白的调节情况。经过长时间的训练，STARS、MRTF-A 和 SRF 的 mRNA 水平都增加了相似的幅度，与训练类型无关。在训练适应状态下，RE 运动后 2.5 和 5 小时测量时 STARS mRNA 增加，运动后 22 小时恢复到静息水平。RE 和 EE 运动后 2.5、5 和 22 小时，MRTF-A 和 SRF mRNA 水平均低于各自的基础水平，两组在任何时间点均无显著差异。两种运动训练或单次运动后，蛋白水平均无变化。本研究表明，ET 和 RT 引起的应激信号导致 STARS 通路成员的调节具有可比性。相比之下，在训练状态下进行单次 EE 和 RE 运动，会引起不同的反应。这些观察结果表明，在训练状态下，EE 或 RE 后 STARS 通路的急性调节可能是运动特异性肌肉适应的原因。
