Authors: Takuto Hayashi, Takashi Kudo, Ryo Fujita, Shin-ichiro Fujita, Hirona Tsubouchi, Sayaka Fuseya, Riku Suzuki, Michito Hamada, Risa Okada, Masafumi Muratani, Dai Shiba, Takafumi Suzuki, Eiji Warabi, Masayuki Yamamoto, Satoru Takahashi
Summary: Microgravity induces skeletal muscle atrophy, particularly in the soleus muscle, which is predominantly composed of slow-twitch myofibre (type I) and is sensitive to disuse. Muscle atrophy is commonly known to be associated with increased production of reactive oxygen species. However, the role of NRF2, a master regulator of antioxidative response, in skeletal muscle plasticity during microgravity-induced atrophy, is not known. To investigate the role of NRF2 in skeletal muscle within a microgravity environment, wild-type and Nrf2-knockout (KO) mice were housed in the International Space Station for 31 days. Gene expression and histological analyses demonstrated that, under microgravity conditions, the transition of type I (oxidative) muscle fibres to type IIa (glycolytic) was accelerated in Nrf2-KO mice without affecting skeletal muscle mass. Therefore, our results suggest that NRF2 affects myofibre type transition during space flight.
Source: Communications Biology, 2021; 4 (1)