Understanding how bear serum slows down biological clock and metabolism for energy saving in skeletal muscle

2022 Fiscal Year Final Research Report

• Project/Area Number: 20KK0355
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (A))
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59040:Nutrition science and health science-related
• Research Institution: The University of Tokushima
• Principal Investigator: NAKAO Reiko 徳島大学, 大学院医歯薬学研究部(医学域), 講師 (20582696)
• Project Period (FY): 2021 – 2022
• Keywords: 体内時計 / 骨格筋

Outline of Final Research Achievements

Hibernating brown bears do not develop muscle atrophy or debilitation although they stay torpid for 5-7 months without eating. The host lab in France has already shown that serum from hibernating brown bear could ameliorate protein degradation in human cultured myotubes. On the other hand, disruption of circadian rhythm in activity and clock gene expression is suggested to relate to the onset of excess muscle catabolism. However, potential effect of bear serum on circadian aspects have not been explored yet. In this study, I found that cells cultured with winter bear serum showed lower oxygen consumption induced by carbohydrate substrates compared with that in cells cultured with summer bear serum. The winter serum also had the effect on modulating circadian rhythm in mouse skeletal muscle, but not in master circadian clock, SCN. There results imply the potential of bear serum to improve metabolic efficiency via driving circadian rhythm in skeletal muscle.

Free Research Field

栄養学

Academic Significance and Societal Importance of the Research Achievements

本研究は、冬眠中のクマの血清に、骨格筋を始めとした末梢組織における体内時計の機能を改善し、無駄なエネルギー消費を抑制する成分が含まれる可能性があることを示すものである。近年、運動不足やバランスの悪い食事だけでなく、夜型生活や睡眠障害といった生体リズムの乱れが筋萎縮や代謝異常のリスク要因であると考えられるようになってきている。本研究の成果はこれらの疾患の予防・改善法開発のための新規ターゲット分子探索のみならず、臓器移植や救急搬送、長期宇宙フライトなどにおける人工的な低代謝の誘導法を開発するための糸口となり得る。