Prevention of muscle atrophy by local bioactive androgen through mechanical stretch

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H02161
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Sports science
• Research Institution: Senshu University
• Principal Investigator: Aizawa Katsuji 専修大学, 経営学部, 教授 (80375477)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 身体運動 / 骨格筋 / アンドロゲン / サルコペニア

Outline of Final Research Achievements

Skeletal muscle is constantly exposed to physical force including exercise or mechanical stretch. Testosterone is converted into its bioactive metabolite dihydrotestosterone (DHT) by 5α-reductase (srd5a1). DHT is also involved in exercise-induced skeletal muscular metabolism. However, it remains to be elucidated whether muscular DHT production through srd5a1 is locally involved in skeletal muscular plasticity. Here we found that local DHT production in skeletal muscle inhibited muscular atrophy through the suppression of atrophy-related gene expression. We show that mechanical stretch transactivates an androgenic enzyme, srd5a1 through the binding of early growth response 2 (Egr2) in skeletal muscle. These results suggest that bioactive androgen metabolism through the Egr2-srd5a1 axis could play important roles in maintaining muscle mass in mechanical stretch.

Free Research Field

スポーツ科学

Academic Significance and Societal Importance of the Research Achievements

本研究成果は、とくに中高齢期におけるサルコペニアの予防や改善メカニズムの基礎的知見として意義があると考えられる。加齢や不活動による骨格筋萎縮の予防において、身体運動による骨格筋機能の維持・改善に骨格筋局所のアンドロゲン産生が関与している可能性が考えられる。