Widegren U, Jiang X J, Krook A, Chibalin A V, Björnholm M, Tally M, Roth R A, Henriksson J, Wallberg-henriksson H, Zierath J R
Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, SE-114 86,
FASEB J. 1998 Oct;12(13):1379-89. doi: 10.1096/fasebj.12.13.1379.
The molecular signaling mechanisms by which muscle contractions lead to changes in glucose metabolism and gene expression remain largely undefined. We assessed whether exercise activates MAP kinase proteins (ERK1/2, SEK1, and p38 MAP kinase) as well as Akt and PYK2 in skeletal muscle from healthy volunteers obtained during and after one-leg cycle ergometry at approximately 70% VO2max. Exercise led to a marked increase in ERK1/2 phosphorylation, which rapidly decreased to resting levels upon recovery. Exercise increased phosphorylation of SEK1 and p38 MAP kinase to a lesser extent than ERK1/2. In contrast to ERK1/2, p38 MAP kinase phosphorylation was increased in nonexercised muscle upon cessation of exercise. Phosphorylation of the transcription factor CREB was increased in nonexercised muscle upon cessation of exercise. Exercise did not activate Akt or increase tyrosine phosphorylation of PYK2. Thus, exercise has divergent effects on parallel MAP kinase pathways, of which only p38 demonstrated a systemic response. However, our data do not support a role of Akt or PYK2 in exercise/contraction-induced signaling in human skeletal. Activation of the different MAP kinase pathways by physical exercise appears to be important in the regulation of transcriptional events in skeletal muscle.
肌肉收缩导致葡萄糖代谢和基因表达变化的分子信号传导机制在很大程度上仍不明确。我们评估了在单腿周期测力计上以约70%最大摄氧量进行运动期间及运动后，从健康志愿者获取的骨骼肌中，运动是否会激活丝裂原活化蛋白激酶（MAPK）蛋白（细胞外信号调节激酶1/2 、 SEK1和p38 MAPK）以及Akt和PYK2 。运动导致ERK1/2磷酸化显著增加，恢复后迅速降至静息水平。运动对SEK1和p38 MAPK磷酸化的增加程度小于ERK1/2 。与ERK1/2不同，运动停止后，未运动肌肉中的p38 MAPK磷酸化增加。运动停止后，未运动肌肉中转录因子CREB的磷酸化增加。运动未激活Akt或增加PYK2的酪氨酸磷酸化。因此，运动对平行的MAPK途径有不同影响，其中只有p38表现出全身反应。然而，我们的数据不支持Akt或PYK2在人体骨骼肌运动/收缩诱导信号传导中的作用。体育锻炼对不同MAPK途径的激活在骨骼肌转录事件的调节中似乎很重要。
