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Muscle follistatin gene delivery increases muscle protein synthesis independent of periodical physical inactivity and fasting
Author(s) -
Nissinen Tuuli A.,
Hentilä Jaakko,
Fachada Vasco,
Lautaoja Juulia H.,
Pasternack Arja,
Ritvos Olli,
Kivelä Riikka,
Hulmi Juha J.
Publication year - 2021
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.202002008r
Subject(s) - myostatin , medicine , endocrinology , follistatin , sarcolemma , muscle atrophy , biology , skeletal muscle , mtorc1 , rheb , pi3k/akt/mtor pathway , signal transduction , microbiology and biotechnology
Blocking of myostatin and activins effectively counteracts muscle atrophy. However, the potential interaction with physical inactivity and fasting in the regulation of muscle protein synthesis is poorly understood. We used blockade of myostatin and activins by recombinant adeno‐associated virus (rAAV)‐mediated follistatin (FS288) overexpression in mouse tibialis anterior muscle. To investigate the effects on muscle protein synthesis, muscles were collected 7 days after rAAV‐injection in the nighttime or in the daytime representing high and low levels of activity and feeding, respectively, or after overnight fasting, refeeding, or ad libitum feeding. Muscle protein synthesis was increased by FS288 independent of the time of the day or the feeding status. However, the activation of mTORC1 signaling by FS288 was attenuated in the daytime and by overnight fasting. FS288 also increased the amount of mTOR colocalized with lysosomes, but did not alter their localization toward the sarcolemma. This study shows that FS288 gene delivery increases muscle protein synthesis largely independent of diurnal fluctuations in physical activity and food intake or feeding status, overriding the physiological signals. This is important for eg cachectic and sarcopenic patients with reduced physical activity and appetite. The FS288‐induced increase in mTORC1 signaling and protein synthesis may be in part driven by increased amount of mTOR colocalized with lysosomes, but not by their localization toward sarcolemma.