Making Mice Mighty: recent advances in translational models of load-induced muscle hypertrophy

Murach KA, McCarthy JJ, Peterson CA, Dungan CM. Making Mice Mighty: recent advances in translational models of load-induced muscle hypertrophy. J Appl Physiol 129: 516 –521, 2020. First published July 16, 2020; doi:10.1152/japplphysiol.00319.2020.—The ability to genetically manipulate mice allows for gain- and loss-of-function in vivo, making them an ideal model for elucidating mechanisms of skeletal muscle mass regulation. Combining genetic models with mechanical muscle loading enables identification of specific factors involved in the hypertrophic response as well as the ability to test the requirement of those factors for adaptation, thereby informing performance and therapeutic interventions. Until recently, approaches for inducing mechanically mediated muscle hypertrophy (i.e., resistance-training analogs) have been limited and considered “nontranslatable” to humans. This mini-review outlines recent translational advances in loading-mediated strategies for inducing muscle hypertrophy in mice, and highlights the advantages and disadvantages of each method. The skeletal muscle field is poised for new breakthroughs in understanding mechanisms regulating load-induced muscle growth given the numerous murine tools that have very recently been described.