Ursolic acid stimulates mTORC1 signaling after resistance exercise in rat skeletal muscle
Ursolic acid stimulates mTORC1 signaling after resistance exercise in rat skeletal muscle
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DOI：
10.1152/ajpendo.00302.2013
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发表时间：
2013-09-01
影响因子：
5.1
通讯作者：
Fujita, Satoshi
中科院分区：
文献类型：
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作者：
Ogasawara, Riki;Sato, Koji;Fujita, Satoshi
最近的一项研究发现，熊果酸（UA）是一种通过PI 3 K/Akt信号传导的肌肉蛋白抑制剂，从而表明UA可以通过Akt信号传导增加抗阻运动诱导的Akt非依赖性mTOR复合物1（mTORC 1）激活。本研究的目的是探讨UA对抗阻运动诱导的mTORC 1激活的影响。通过经皮电刺激对11周龄雄性Sprague-Dawley大鼠的右腓肠肌进行等距运动（每组刺激10次，共5组），而左腓肠肌作为对照。运动后立即腹腔注射UA或安慰剂（PLA;仅玉米油）。运动结束后1或6 h处死大鼠，立即切除靶组织。注射安慰剂后，抗阻运动后1h，P70（S6 K）Thr（389）磷酸化水平升高，但运动后6 h减弱至对照组水平。另一方面，增强磷酸化的p70（S6 K），即使在运动后6小时，当UA运动后立即注射。在PRAS 40 Thr（246）中观察到了类似的磷酸化延长趋势，而单独使用UA或单独使用抗阻运动在干预后6 h并未改变其磷酸化水平。这些结果表明，UA能够维持阻力运动诱导的mTORC 1活性。
A recent study identified ursolic acid (UA) as a potent stimulator of muscle protein anabolism via PI3K/Akt signaling, thereby suggesting that UA can increase Akt-independent mTOR complex 1 (mTORC1) activation induced by resistance exercise via Akt signaling. The purpose of the present study was to investigate the effect of UA on resistance exercise-induced mTORC1 activation. The right gastrocnemius muscle of male Sprague-Dawley rats aged 11 wk was isometrically exercised via percutaneous electrical stimulation (stimulating ten 3-s contractions per set for 5 sets), while the left gastrocnemius muscle served as the control. UA or placebo (PLA; corn oil only) was injected intraperitoneally immediately after exercise. The rats were killed 1 or 6 h after the completion of exercise and the target tissues removed immediately. With placebo injection, the phosphorylation of p70(S6K) at Thr(389) increased 1 h after resistance exercise but attenuated to the control levels 6 h after the exercise. On the other hand, the augmented phosphorylation of p70(S6K) was maintained even 6 h after exercise when UA was injected immediately after exercise. A similar trend of prolonged phosphorylation was observed in PRAS40 Thr(246), whereas UA alone or resistance exercise alone did not alter its phosphorylation level at 6 h after intervention. These results indicate that UA is able to sustain resistance exercise-induced mTORC1 activity.