Cory M Dungan1, Zhuyun Li1, David C Wright2, David L Williamson1. 1. Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York, USA. 2. Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada.
Abstract
INTRODUCTION: Appropriate activation of growth signaling pathways, specifically mammalian target of rapamycin complex 1 (mTORC1), is central to muscle mass and metabolism. The goal of these studies was to examine the effects of metformin on mTORC1 signaling in aged skeletal muscle in an attempt to normalize growth signaling. METHODS: Aged (23m) and young (3m) male mice were fed a low fat diet without or with 0.5% metformin for up to 8 weeks, then mTORC1-related signaling was examined in the plantar flexor complex. RESULTS: Metformin had no significant effect on lowering body weight or muscle mass in aged animals, nor altered p70 S6 Kinase 1 (S6K1) and 4E-binding protein 1 (4E-BP1) phosphorylation. However, it significantly (P < 0.05) reduced body weight and lowered S6K1 and rpS6 phosphorylation in the young. CONCLUSIONS: Collectively, these data suggest metformin is ineffective at normalizing growth signaling in aged skeletal muscle.
INTRODUCTION: Appropriate activation of growth signaling pathways, specifically mammalian target of rapamycin complex 1 (mTORC1), is central to muscle mass and metabolism. The goal of these studies was to examine the effects of metformin on mTORC1 signaling in aged skeletal muscle in an attempt to normalize growth signaling. METHODS: Aged (23m) and young (3m) male mice were fed a low fat diet without or with 0.5% metformin for up to 8 weeks, then mTORC1-related signaling was examined in the plantar flexor complex. RESULTS:Metformin had no significant effect on lowering body weight or muscle mass in aged animals, nor altered p70 S6 Kinase 1 (S6K1) and 4E-binding protein 1 (4E-BP1) phosphorylation. However, it significantly (P < 0.05) reduced body weight and lowered S6K1 and rpS6 phosphorylation in the young. CONCLUSIONS: Collectively, these data suggest metformin is ineffective at normalizing growth signaling in aged skeletal muscle.
Authors: N Zeng; U Prodhan; R F D'Souza; F Ramzan; S M Mitchell; P Sharma; S O Knowles; N C Roy; A Sjödin; K-H Wagner; A M Milan; D Cameron-Smith; C J Mitchell Journal: J Nutr Health Aging Date: 2019 Impact factor: 4.075
Authors: Andrew D Ray; Kirkwood E Personius; David L Williamson; Cory M Dungan; Samjot S Dhillon; Pamela A Hershberger Journal: J Appl Physiol (1985) Date: 2016-03-10
Authors: Cory M Dungan; Kevin A Murach; Christopher J Zdunek; Zuo Jian Tang; Georgia L VonLehmden; Camille R Brightwell; Zachary Hettinger; Davis A Englund; Zheng Liu; Christopher S Fry; Antonio Filareto; Michael Franti; Charlotte A Peterson Journal: Aging Cell Date: 2021-12-13 Impact factor: 9.304