Mechanisms of fibrosis progression induced by icing treatment after skeletal muscle injury

Research Project

Project/Area Number	17K13186
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Sports science
Research Institution	Kanazawa University
Principal Investigator	Shibaguchi Tsubasa 金沢大学, GS教育系, 助教 (40785953)
Project Period (FY)	2017-04-01 – 2020-03-31
Project Status	Completed (Fiscal Year 2019)
Budget Amount *help	¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000) Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000) Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000) Fiscal Year 2017: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Keywords	筋再生 / アイシング / 線維化 / 温熱刺激 / 筋損傷
Outline of Final Research Achievements	The purpose of this study was to investigate possible mechanisms of fibrosis progression induced by icing (ICE) treatment after skeletal muscle injury and possible countermeasure against its negative phenomenon. ICE treatment after the injury induced different responses in gene expression between soleus and plantaris muscles. ICE with intermittent heat stress (HOT) starting from both 1-day and 2-day after the injury attenuated the ICE-related promotion of fibrosis in soleus muscle, and its inhibitory effect was stronger in the 1-day than in the 2-day conditions. However, the degree of fibrosis in the 1-day condition was similar to the non-treated injured muscle. These findings indicated that physiological action of ICE to injured skeletal muscle might be different between slow and fast muscles. Our data also suggested that ICE with intermittent HOT after skeletal muscle injury could attenuate the ICE-related acceleration of fibrosis at the same level as a non-therapeutic condition.
Academic Significance and Societal Importance of the Research Achievements	「アイシング処置が損傷した骨格筋の再生を妨げる」という発見は、従来のスポーツ医学の常識を覆すものであるが、そのメカニズムについては未だ明らかでない。本研究では、筋損傷に対するアイシング処置がその後の回復過程において遅筋と速筋の場合で異なる遺伝子発現応答を引き起こす可能性があること、ならびに筋損傷後のアイシング処置と温熱刺激の併用が温熱刺激の開始時期を早めることでアイシングによって促進する線維化を無処置の場合と同レベルまでは減弱できることが示唆された。これらの成果は、今後のアイシング処置の在り方の再考や、治癒期間の短縮や完治を目指した新たな方策を見出すための基礎資料になると考えられる。