Roles played by ribosome biogenesis in exercise-induced muscle hypertrophy

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03078
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Sports science
• Research Institution: The University of Tokyo
• Principal Investigator: Ishii Naokata 東京大学, 大学院総合文化研究科, 教授 (20151326)
• Co-Investigator(Kenkyū-buntansha): 中里 浩一 日本体育大学, 保健医療学部, 教授 (00307993) ; 小笠原 理紀 名古屋工業大学, 工学(系)研究科(研究院), 准教授 (10634602)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: トレーニング / 筋肥大 / リボソーム量 / タンパク質合成 / 翻訳容量 / 翻訳効率 / mTORシグナル伝達系

Outline of Final Research Achievements

This study aimed to investigate the role played by ribosome biogenesis in exercise-induced muscle hypertrophy using the rat skeletal muscles. A compensatory hypertrophy model, with which the degree of hypertrophy could be controlled, showed that both the ribosomal content and the expression of UBF (upstream binding factor), a transcription factor for rRNA, are strongly correlated with the degree of hypertrophy. In a resistance-training model, the muscle hypertrophy after the exercise period for 6 weeks showed a close association with the increase in ribosomal content. The ribosomal content increased at an early stage of training period (within 1 wk. after the initiation of training), and changed following a different time course from those of mTOR signal transduction activity and protein synthesis. These results suggest that the ribosomal content changes dynamically with the training stimulus, and the ribosomal biogenesis plays an important part in exercise-induced muscle hypertrophy.

Free Research Field

筋生理学