Role of muscle-specific insulin in prevention and formation of sarcopenia

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K19752
• 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: Tokyo Metropolitan University
• Principal Investigator: Fujii Nobuharu 首都大学東京, 人間健康科学研究科, 教授 (40509296)
• Project Period (FY): 2018-06-29 – 2020-03-31
• Keywords: 骨格筋 / サルコペニア / インスリン / C2C12細胞

Outline of Final Research Achievements

Insulin is highly and specifically expressed in the beta-cells of pancreas. However, we have found that insulin is also significantly expressed in the muscle cells although the expression level is lower than that in the beta-cells. I order to clarify the role of muscle-specif insulin in skeletal muscle tissue, we established C2C12 cell lines which has no expression of insulin due to point mutation of insulin 1 and insulin 2 genes in the genome that made with CRISPER-Cas9 method. Insulin depleted C2C12 cell lines had impaired proliferation and differentiation, suggested that muscle-specific insulin may contribute to maintain muscle mass. However, since variability of the results among the cell lines was relatively huge, more intensive investigation is nessesary.

Free Research Field

骨格筋生物学、分子生物学

Academic Significance and Societal Importance of the Research Achievements

加齢にともなう筋委縮の進行現象であるサルコペニアは、高齢者の生活の質を著しく低下させるため、その生成機序を明らかにすることと、その予防策を講じることは、超高齢者社会を迎えた日本では必須とされている。インスリンが骨格筋に発現していることは、申請者も含めて、多くの研究者が気づかなかったことである。しかし、一般的なインスリンの性質から、筋の同化作用に貢献している可能性が考えられる。本研究ではその一部が確かめられ、新たなサルコペニアの生成機序の一端を明らかにすることができた。