Trenerry Marissa K, Carey Kate A, Ward Alister C, Cameron-Smith David
School of Exercise and Nutrition Science, Deakin University, Burwood, Victoria, Australia.
J Appl Physiol (1985). 2007 Apr;102(4):1483-9. doi: 10.1152/japplphysiol.01147.2006. Epub 2007 Jan 4.
The transcription factor signal transducer and activator of transcription 3 (STAT3) has been identified as a mediator of cytokine signaling and implicated in hypertrophy; however, the importance of this pathway following resistance exercise in human skeletal muscle has not been investigated. In the present study, the phosphorylation and nuclear localization of STAT3, together with STAT3-regulated genes, were measured in the early recovery period following intense resistance exercise. Muscle biopsy samples from healthy subjects (7 males, 23.0 + 0.9 yr) were harvested before and again at 2, 4, and 24 h into recovery following a single bout of maximal leg extension exercise (3 sets, 12 repetitions). Rapid and transient activation of phosphorylated (tyrosine 705) STAT3 was observed at 2 h postexercise. STAT3 phosphorylation paralleled the transient localization of STAT3 to the nucleus, which also peaked at 2 h postexercise. Downstream transcriptional events regulated by STAT3 activation peaked at 2 h postexercise, including early responsive genes c-FOS (800-fold), JUNB (38-fold), and c-MYC (140-fold) at 2 h postexercise. A delayed peak in VEGF (4-fold) was measured 4 h postexercise. Finally, genes associated with modulating STAT3 signaling were also increased following exercise, including the negative regulator SOCS3 (60-fold). Thus, following a single bout of intense resistance exercise, a rapid phosphorylation and nuclear translocation of STAT3 are evident in human skeletal muscle. These data suggest that STAT3 signaling is an important common element and may contribute to the remodeling and adaptation of skeletal muscle following resistance exercise.
转录因子信号转导与转录激活因子3（STAT3）已被确定为细胞因子信号传导的介质，并与肥大有关；然而，该通路在人体骨骼肌抗阻运动后的重要性尚未得到研究。在本研究中，在高强度抗阻运动后的早期恢复阶段，对STAT3的磷酸化和核定位以及受STAT3调控的基因进行了测量。在一次最大腿部伸展运动（3组，每组12次重复）之前以及恢复后的2、4和24小时，采集了健康受试者（7名男性，23.0±0.9岁）的肌肉活检样本。运动后2小时观察到磷酸化（酪氨酸705）STAT3的快速和短暂激活。STAT3磷酸化与STAT3向细胞核的短暂定位平行，后者在运动后2小时也达到峰值。由STAT3激活调节的下游转录事件在运动后2小时达到峰值，包括早期反应基因c-FOS（800倍）、JUNB（38倍）和c-MYC（140倍）在运动后2小时。运动后4小时测量到VEGF（4倍）出现延迟峰值。最后，与调节STAT3信号相关的基因在运动后也增加了，包括负调节因子SOCS3（60倍）。因此，在单次高强度抗阻运动后，STAT3在人体骨骼肌中出现快速磷酸化和核转位。这些数据表明，STAT3信号是一个重要的共同因素，可能有助于抗阻运动后骨骼肌的重塑和适应。
