ABSTRACT

　Skeletal muscle tissue is known to play an important role in not only motor function but also metabolic function in the body. It is considered that the metabolic rate in the female body is estimated about 70% of male, due to skeletal muscle mass difference. However, the mechanism, which causes skeletal muscle mass difference by gender, have not been completely clarified yet. In this study, we hypothesized that such difference in muscle mass by gender is caused by the difference in differentiation ability of muscle cell lineage. Therefore, we differentiated both female and male derived-iPSCs into skeletal muscle cells using a forced expression of h MyoD1. Both female and male iPSCs expressed Skeletal Muscle Actin by 9 days after h MyoD1overexpression. To evaluate muscle cell differentiation in both iPSCs, we continuously quantified the expression of myosin heavy chain (MHC), a marker of skeletal muscle cells, by western blotting. During the differentiation from iPSCs into muscle cells, male derived-cells began to express MHC earlier and expressed increased amount of MHC at 9 days after h MyoD1 overexpression compared to female derived-cells. These data may suggest that the differentiation potential into skeletal muscle might be accelerated in male-derived cells compared to female-derived cells and such characteristics might result in skeletal muscle mass difference by gender.

DESCENTE SPORTS SCIENCE Vol.39/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE