It is postulated that testosterone-induced skeletal muscle hypertrophy is driven by myonuclear accretion as the result of satellite cell fusion. To directly test this hypothesis, we utilized the Pax7-DTA mouse model to deplete satellite cells in skeletal muscle followed by testosterone administration. Pax7-DTA mice (6 mo of age) were treated for 5 days with either vehicle [satellite cell replete (SC+)] or tamoxifen [satellite cell depleted (SC-)]. Following a washout period, a testosterone propionate or sham pellet was implanted for 21 days. Testosterone administration caused a significant increase in muscle fiber cross-sectional area in SC+ and SC- mice in both oxidative (soleus) and glycolytic (plantaris and extensor digitorum longus) muscles. In SC+ mice treated with testosterone, there was a significant increase in both satellite cell abundance and myonuclei that was completely absent in testosterone-treated SC- mice. These findings provide direct evidence that testosterone-induced muscle fiber hypertrophy does not require an increase in satellite cell abundance or myonuclear accretion. Listen to a podcast about this Rapid Report with senior author E. E. Dupont-Versteegden (https://ajpcell.podbean.com/e/podcast-on-paper-that-shows-testosterone-induced-skeletal-muscle-hypertrophy-does-not-need-muscle-stem-cells/).
|American Journal of Physiology - Cell Physiology
|Published - 2019
Bibliographical noteFunding Information:
This work was supported by funds from the Endowed University Professorship in Health Sciences, University of Kentucky, and NIH National Institute of Arthritis and Musculoskeletal and Skin Diseases Grant AR060701 to C. A. Peterson and J. J. McCarthy and Grant AR071753 to K. A. Murach. The project described was also supported by NIH National Center for Advancing Translational Sciences through Grant TL1 TR001997 (to D. A. Englund).
Copyright © 2019 the American Physiological Society
- Satellite cell
- Skeletal muscle
- Stem cell
ASJC Scopus subject areas
- Cell Biology