The effect of heat stress on signal transduction during the recovery from skeletal muscle atrophy induced by hindlimb-unweighted

后肢失重引起的骨骼肌萎缩恢复过程中热应激对信号转导的影响

• 批准号: 15500446
• 负责人: SUGIURA Takao
• 金额: $ 2.43万
• 依托单位: Yamaguchi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15500446/
• 关键词: muscle atrophy; restoration; heat stress; signal transduction; 熱ショックタンパク質; カルシニューリン

It has been recently reported that Akt/mTOR/p70^<S6K>/S6 and calcineurin signaling pathways are a crucial regulator of skeletal muscle hypertrophy. We have showed that the heat stress accelerates the recovery from skeletal muscle atrophy induced by hindlimb unweighting. However, the mechanism responsible for the promoting effects of heat stress on atrophied muscles remains unclear. In this study, we investigated the role of the Akt and calcineurin signaling pathway in the recovery of the atrophied skeletal muscle with heat and its optimum exposure time. Wistar strain male rats (8-week-old) were divided into four groups : control (Con), hindlimb unweighting (HLU), heat stress for 15 (Heat 15) and 30 (Heat 30) min after hindlimb unweighting. HLU, Heat 15 and Heat 30 groups were subjected to hindlimb unweighting for 10 days. Immediately after release from unweighting, heat groups were immersed into hot water (42℃) under anesthesia. After 0, 3 and 10 days, soleus muscles were dissected. Muscle weight-to-body weight ratios of HLU and Heat 15 were significantly higher than 0 day in each group. The myofibrillar content of Heat 30 was significantly lower than Con at 10 day recovery period. The expression of phospho-mTOR in Heat 15 was significantly higher than the other groups after 0 days of muscle reloding. Phospho-S6 ribosomal levels after 3 day recovery period were significantly greater in the order : Heat 15, HLU, Heat 30 and Con. These results suggest that the heat stress promotes the recovery of atrophied skeletal muscle in part via Akt/mTOR/p70^<S6K>/S6 signaling pathway and the optimum exposure time for its promotion exist.

最近有报道称Akt/mTor/p70；S6K/S6和钙调神经磷酸酶信号通路是骨骼肌肥大的重要调节因子。我们已经证明，热应激加速了后肢减重所致的骨骼肌萎缩的恢复。然而，热应激对萎缩肌肉的促进作用机制尚不清楚。在本研究中，我们研究了Akt和钙调神经磷酸酶信号通路在高温下骨骼肌萎缩恢复中的作用及其最佳暴露时间。将8周龄雄性Wistar大鼠分为对照组(CON)、后肢去重组(HLU)、后肢去重后热应激15分钟(热15)和热应激30分钟(热30)组。HLU组、热15组和热30组进行后肢去重10天。失重后即刻，热组在麻醉下浸泡在热水(42℃)中。术后0、3、10d解剖比目鱼肌。HLU组和HEAT 15组的肌体比均显著高于0日龄。在恢复期第10天，热30的肌原纤维含量显著低于对照。肌肉恢复0天后，热15组磷酸化mTOR表达显著高于其他组。3天恢复期后磷酸化S6核糖体水平显著升高，其大小顺序为：HLU>HEAT 15>HLU>HEAT 30>Con.提示热应激部分通过Akt/mTOR/p70^&lt；S6K&gt；/S6信号通路促进萎缩骨骼肌的恢复，且存在促进其恢复的最佳暴露时间.

项目成果

Changes in protein kinase B (PKB/Akt) and calcineurin signaling during recovery in atrophied soleus muscle_induced by unloading.

卸载引起的萎缩比目鱼肌恢复过程中蛋白激酶 B (PKB/Akt) 和钙调磷酸酶信号的变化。

• 发表时间: 2005
• 期刊: Am J Physiol Regul Integr Comp Physiol. 288
• 作者: Sugiura T.;Abe N.;Nagano M.;et al.
• 通讯作者: et al.

Changes in protein kinase B(PKB/Akt) and calcineurin signaling during recovery in atrophied soleus muscle induced by unloading

卸载引起的萎缩比目鱼肌恢复过程中蛋白激酶 B (PKB/Akt) 和钙调神经磷酸酶信号的变化

• 发表时间: 2005
• 期刊: Am J Physiol Regul Integr Comp Physiol. 288
• 作者: Sugiura T.;Abe N.;Nagano M.;Goto K.;Sakuma K.;Naito H.;Yoshioka T.;Power S.K.
• 通讯作者: Power S.K.

Changes in protein kinase B (PKB/Akt) and calcineurin signaling during recovery in atrophied soleus muscle induced by unloading.

卸载引起的萎缩比目鱼肌恢复过程中蛋白激酶 B (PKB/Akt) 和钙调磷酸酶信号的变化。

• 发表时间: 2005
• 期刊: Am J Physiol Regul Integr Comp Physiol. 288
• 作者: Sugiura T.;Abe N.;Nagano M.;Goto K.;Sakuma K.;Naito H.;Yoshioka T.;Powers S.K.
• 通讯作者: Powers S.K.