Age-related differences in signal transduction during recovery in atrophied plantaris muscle induced by immobilization

固定引起的萎缩跖肌恢复过程中信号转导的年龄相关差异

基本信息

批准号：
17500428
负责人：
SUGIURA Takao
金额：
$ 2.52万
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：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17500428/
关键词：
muscle atrophy restoration signal ransduction aging

项目摘要

It has been recently reported that Akt/mTOR/p70^<S6K>/S6 and calcineurin (CaN) are both postulated to play important roles in integrating intracellular signaling in skeletal muscle in response to both disuse and increased muscle loading. These experiments investigated the age-related differences in signal transduction of the downstream pathways of both Akt/mTOR/p70^<S6K>/S6 and CaN during a period of recovery following immobilization-induced muscle atrophy. The hindlimb muscles of one leg in young (10 weeks), adult (1 year) and old (2 years) were immobilized in plantar flexion position using a plaster cast for 10 days. At 0,7 and-15 days after the removal of plaster cast, both the atrophic and the contralateral plantaris muscles were removed.Immobilization resulted in significant muscle atrophy in all experimntal animals. Muscle mass in young animal recovered up to -90% following 10-days of recovery period, but not in adult and old animals. The expressions of phospho-Akt, phospho-mTOR and phospho- p70^<S6K> in atrophied muscles from young rats were significantly higher in all of recovery period compared with control muscles, with the greatest changes seen in recovery day 15, but not in adult and old animals. Muscle levels of phosphorylated 56 in young rats were higher following 7-and 15 days of recovery. A similar tendency was observed in adult rats, but not in old rats. The expressions of phospho-eIF4E and calcineurin in atrophied muscles were unchanged in all of recovery period and experimental groups. Muscle levels of phosphorylated eIF4G in young rats were higher following 7-and 15 days of recovery, but not in adult and old rats. These results show that the activation of Akt/mTOR signaling pathways involved in the protein synthesis during recovery in atrophied plantaris muscle differ with age.

最近有报道称，AKT/MTOR/P70^<S6K>/S6和钙调蛋白（CAN）都假定在响应骨骼肌肉中对骨骼肌肉中的细胞内信号传导起着重要作用，以响应骨骼肌肉，以响应肌肉负荷和增加的肌肉负荷。这些实验研究了AKT/MTOR/MTOR/P70^<S6K>/S6的下游途径信号转导的年龄相关差异，并且在固定诱导的肌肉萎缩后的恢复期间可以进行。年轻（10周），成人（1年）和旧（2岁）的一条腿的后肢肌肉使用石膏铸造10天，将其固定在足底屈曲位置。在去除石膏铸件后的0,7和15天后，去除萎缩和对侧足肌肌肉。对所有实验动物的iMmbibilization均导致明显的肌肉萎缩。在恢复期10天之后，年轻动物的肌肉质量恢复了高达-90％，但在成年动物和老动物中没有恢复。与对照肌肉相比，在整个恢复期间，磷酸化，磷酸-MTOR和磷酸p70^<s6k>的表达明显更高，在第15天恢复，但在成年动物和老动物中却没有发生巨大变化。恢复7天和15天后，年轻大鼠的磷酸化56个磷酸化的56个较高。在成年大鼠中观察到类似的趋势，但在老鼠中却没有观察到类似的趋势。在整个恢复期和实验组中，萎缩肌肉中磷酸-EIF4E和钙调蛋白的表达不变。恢复7天和15天后，年轻大鼠的磷酸化EIF4G的肌肉水平较高，但在成年大鼠中却没有。这些结果表明，在萎缩的plant骨肌肉恢复过程中，蛋白质合成涉及的Akt/MTOR信号通路的激活随着年龄的增长而异。