Heesch Matthew W, Shute Robert J, Kreiling Jodi L, Slivka Dustin R
Department of Kinesiology, Washburn University, Topeka, Kansas;
School of Health, Physical Education, and Recreation, University of Nebraska at Omaha, Omaha, Nebraska; and.
J Appl Physiol (1985). 2016 Sep 1;121(3):741-9. doi: 10.1152/japplphysiol.01065.2015. Epub 2016 Jul 21.
The purpose of this study was to determine mitochondrial biogenesis-related mRNA expression, binding of transcription factors to the peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC-1α) promoter, and subcellular location of PGC-1α protein in human skeletal muscle following exercise in a hot environment compared with a room temperature environment. Recreationally trained males (n = 11) completed two trials in a temperature- and humidity-controlled environmental chamber. Each trial consisted of cycling in either a hot (H) or room temperature (C) environment (33 and 20°C, respectively) for 1 h at 60% of maximum wattage (Wmax) followed by 3 h of supine recovery at room temperature. Muscle biopsies were taken from the vastus lateralis pre-, post-, and 3 h postexercise. PGC-1α mRNA increased post (P = 0.039)- and 3 h postexercise in C (P = 0.002). PGC-1α, estrogen-related receptor-α (ERRα), and nuclear respiratory factor 1 (NRF-1) mRNA was all lower in H than C post (P = 0.038, P < 0.001, and P = 0.030, respectively)- and 3 h postexercise (P = 0.035, P = 0.007, and P < 0.001, respectively). Binding of cAMP response element-binding protein (CREB) (P = 0.005), myocyte enhancer factor 2 (MEF2) (P = 0.047), and FoxO forkhead box class-O1 (FoxO1) (P = 0.010) to the promoter region of the PGC-1α gene was lower in H than C. Nuclear PGC-1α protein increased postexercise in both H and C (P = 0.029) but was not different between trials (P = 0.602). These data indicate that acute exercise in a hot environment blunts expression of mitochondrial biogenesis-related mRNA, due to decreased binding of CREB, MEF2, and FoxO1 to the PGC-1α promoter.
本研究的目的是确定在热环境中运动后，与线粒体生物合成相关的mRNA表达、转录因子与过氧化物酶体增殖物激活受体γ共激活因子1α（PGC-1α）启动子的结合，以及PGC-1α蛋白在人骨骼肌中的亚细胞定位，并与室温环境进行比较。接受过休闲训练的男性（n = 11）在温度和湿度可控的环境舱中完成了两项试验。每项试验包括在热（H）或室温（C）环境（分别为33和20°C）中以最大瓦数（Wmax）的60%进行1小时的骑行，随后在室温下仰卧恢复3小时。在运动前、运动后和运动后3小时从股外侧肌采集肌肉活检样本。PGC-1α mRNA在C组运动后（P = 0.039）和运动后3小时（P = 0.002）增加。在运动后（分别为P = 0.038、P < 0.001和P = 0.030）和运动后3小时（分别为P = 0.035、P = 0.007和P < 0.001），H组中PGC-1α、雌激素相关受体α（ERRα）和核呼吸因子1（NRF-1）的mRNA均低于C组。在H组中，环磷酸腺苷反应元件结合蛋白（CREB）（P = 0.005）、肌细胞增强因子2（MEF2）（P = 0.047）和FoxO叉头框O1类（FoxO1）（P = 0.010）与PGC-1α基因启动子区域的结合低于C组。核PGC-1α蛋白在H组和C组运动后均增加（P = 0.029），但试验之间无差异（P = 0.602）。这些数据表明，在热环境中进行急性运动可减弱线粒体生物合成相关mRNA的表达，这是由于CREB、MEF2和FoxO1与PGC-1α启动子的结合减少所致。
