Open AccessAcute treadmill exercise discriminately improves the skeletal muscle insulin‐stimulated growth signaling responses in mice lacking REDD1
Author(s) -
Dungan Cory M.,
Gordon Bradley S.,
Williamson David L.
Publication year - 2019
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.14011
Subject(s) - mtorc1 , endocrinology , medicine , protein kinase b , p70 s6 kinase 1 , insulin , foxo1 , insulin resistance , insulin receptor , ampk , phosphorylation , skeletal muscle , biology , protein kinase a , microbiology and biotechnology
A loss of the re gulated in d evelopment and D NA damage 1 ( REDD 1) hyperactivates mechanistic Target of Rapamycin Complex 1 ( mTORC 1) reducing insulin‐stimulated insulin signaling, which could provide insight into mechanisms of insulin resistance. Although aerobic exercise acutely inhibits mTORC 1 signaling, improvements in insulin‐stimulated signaling are exhibited. The goal of this study was to determine if a single bout of treadmill exercise was sufficient to improve insulin signaling in mice lacking REDD 1. REDD 1 wildtype ( WT ) and REDD 1 knockout ( KO ) mice were acutely exercised on a treadmill (30 min, 20 m/min, 5% grade). A within animal noninsulin‐to‐insulin‐stimulated percent change in skeletal muscle insulin‐stimulated kinases ( IRS ‐1, ERK 1/2, Akt), growth signaling activation (4E‐ BP 1, S6K1), and markers of growth repression ( REDD 1, AMPK , FOXO 1/3A) was examined, following no exercise control or an acute bout of exercise. Unlike REDD 1 KO mice, REDD 1 WT mice exhibited an increase ( P < 0.05) in REDD 1 following treadmill exercise. However, both REDD 1 WT and KO mice exhibited an increase ( P < 0.05) A MPK phosphorylation, and a subsequent reduction ( P < 0.05) in mTORC 1 signaling after the exercise bout versus nonexercising WT or KO mice. Exercise increased ( P < 0.05) the noninsulin‐to‐insulin‐stimulated percent change phosphorylation of mTORC 1, ERK 1/2, IRS ‐1, and Akt on S473 in REDD 1 KO mice when compared to nonexercised KO mice. However, there was no change in the noninsulin‐to‐insulin‐stimulated percent change activation of Akt on T308 and FOXO 1/3A in the KO when compared to WT or KO mouse muscle after exercise. Our data show that a bout of treadmill exercise discriminately improves insulin‐stimulated signaling in the absence of REDD1.