RRC ID 31997
Author Zheng DM, Bian Z, Furuya N, Oliva Trejo JA, Takeda-Ezaki M, Takahashi K, Hiraoka Y, Mineki R, Taka H, Ikeda S, Komatsu M, Fujimura T, Ueno T, Ezaki J.
Title A treadmill exercise reactivates the signaling of the mammalian target of rapamycin (mTor) in the skeletal muscles of starved mice.
Journal Biochem. Biophys. Res. Commun.
Abstract It has been well established that a starvation-induced decrease in insulin/IGF-I and serum amino acids effectively suppresses the mammalian target of rapamycin (mTor) signaling to induce autophagy, which is a major degradative cellular pathway in skeletal muscles. In this study, we investigated the systematic effects of exercise on the mTor signaling of skeletal muscles. Wild type C57BL/6J mice were starved for 24h under synchronous autophagy induction conditions. Under these conditions, endogenous LC3-II increased, while both S6-kinse and S6 ribosomal protein were dephosphorylated in the skeletal muscles, which indicated mTor inactivation. Using GFP-LC3 transgenic mice, it was also confirmed that fluorescent GFP-LC3 dots in the skeletal muscles increased, including soleus, plantaris, and gastrocnemius, which clearly showed autophagosomal induction. These starved mice were then subjected to a single bout of running on a treadmill (12m/min, 2h, with a lean of 10 degrees). Surprisingly, biochemical analyses revealed that the exercise elicited a decrease in the LC3-II/LC3-I ratio as well as an inversion from the dephosphorylated state to the rephosphorylated state of S6-kinase and ribosomal S6 in these skeletal muscles. Consistently, the GFP-LC3 dots of the skeletal muscles were diminished immediately after the exercise. These results indicated that exercise suppressed starvation-induced autophagy through a reactivation of mTor signaling in the skeletal muscles of these starved mice.
Volume 456(1)
Pages 519-26
Published 2015-1-2
DOI 10.1016/j.bbrc.2014.11.118
PII S0006-291X(14)02160-3
PMID 25485704
MeSH Animals Autophagy Mice Mice, Inbred C57BL Mice, Transgenic Microtubule-Associated Proteins / metabolism Muscle, Skeletal / metabolism Phosphorylation Physical Conditioning, Animal* Ribosomal Protein S6 Kinases / metabolism Running Signal Transduction Starvation TOR Serine-Threonine Kinases / metabolism*
IF 2.559
Times Cited 4
Mice GFP-LC3#53(RBRC00806)