Elucidation of the mechanism of accelerated progression of muscle atrophy in obese mice

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K17934
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59040:Nutrition science and health science-related
• Research Institution: Chubu University
• Principal Investigator: Goto Ayumi 中部大学, 生命健康科学部, 助手 (20780969)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 骨格筋 / 肥満 / 筋萎縮 / 炎症性サイトカイン / IL-6

Outline of Final Research Achievements

Recently, it has been reported that obesity may contribute to the loss of skeletal muscles. However, the obesity-related cellular mechanisms during inactivity still need to be elucidated. The purpose of this study was to determine the effects of obesity on degradation-related signaling pathways and inflammatory mediators in muscles during inactivity. Mice were fed either a normal diet (ND) or a high fat diet (HFD). Then, the hind limbs of all mice were unilaterally immobilized for 6 h (initial phase) or 1, 3 and 7 days (long-term inactivity). In the 7 days, the HFD significantly augmented loss of mass rate as compared with ND. Due to long-term inactivity, the expression level of MuRF1 mRNA 3days in soleus and plantaris muscles was significantly higher in the HFD compared with the ND. Moreover, IL-6 mRNA expression was significantly increased by immobilization in the HFD during the initial phase of inactivity. We showed that HFD affects inflammatory mediators during muscle inactivity.

Free Research Field

骨格筋

Academic Significance and Societal Importance of the Research Achievements

肥満が筋萎縮の進行を促進させる可能性が示唆されている社会的背景として、加齢に伴う筋量減少（サルコペニア）と肥満が組み合わさった病態である「サルコペニア肥満」が歩行障害のリスクを増加させ、寝たきり高齢者を増加させることが問題となっている。本研究の成果は、サルコペニア肥満など肥満と筋萎縮に関連した疾患の治療・予防法の開発への足掛かりになり、寝たきり高齢者の予防・対策に繋がる可能性があると考えている。