Interplay between muscle stem cells and immune cells in skeletal muscle hypertrophy

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K19723
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 59:Sports sciences, physical education, health sciences, and related fields
• Research Institution: Sapporo Medical University
• Principal Investigator: Yamada Takashi 札幌医科大学, 保健医療学部, 准教授 (50583176)
• Co-Investigator(Kenkyū-buntansha): 小笠原 理紀 国立研究開発法人産業技術総合研究所, 生命工学領域, 主任研究員 (10634602)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 伸張性収縮 / 筋損傷 / 筋肥大 / 修復 / 筋サテライト細胞 / 免疫細胞

Outline of Final Research Achievements

It has been believed that eccentric contractions effectively induce skeletal muscle hypertrophy by causing micro-damage to the skeletal muscles. The theoretical background for this involves the activation of muscle satellite cells, possibly by infiltrating macrophages. On the other hand, the results of this study showed that the recovery process of muscle strength and histological characteristics after eccentric contractions showed no differences between satellite cell-depleted mice and normal mice, although the absence of macrophages led to a decrease in muscle strength in normal mice. Therefore, these data suggest that muscle satellite cells are not essential for the repair and hypertrophic adaptation of skeletal muscles in response to eccentric contractions.

Free Research Field

筋機能制御学

Academic Significance and Societal Importance of the Research Achievements

本研究の結果，伸張性収縮後の回復過程には筋サテライト細胞が必須ではないことが示されたことから，筋核ドメイン説を基盤に従来説明されてきた筋肥大や筋萎縮，筋損傷およびその回復に関して，筋サテライト細胞と筋核の両者を指標とした理論体系の再考による筋生理学・病理学分野の学術的発展が期待される．また，その波及効果として，サルコペニア，筋ジストロフィー症，スポーツ傷害等の予防・治療およびスポーツパフォーマンスの向上などに向けたトレーニングの分子機構の理解が進展し，骨格筋の機能，量の向上を効果的に引き起こす画期的な方法論の開発へとつながる可能性がある．