Research Paper Volume 10, Issue 6 pp 1356—1365
Aged cells in human skeletal muscle after resistance exercise
- 1 Laboratory of Exercise Biochemistry, University of Taipei, Taipei, Taiwan
- 2 Competitor Institute of Sports Nutrition, Beijing, China
- 3 Norwegian School of Sport Science, Oslo, Norway
- 4 Department of Anesthesiology, Far East Memorial Hospital, New Taipei, Taiwan
- 5 Graduate Institute of Basic Medicine, China Medical University, Taichung, Taiwan
- 6 Department of Biological Science and Technology, Asia University, Taichung, Taiwan
Received: April 11, 2018 Accepted: June 7, 2018 Published: June 27, 2018
https://doi.org/10.18632/aging.101472How to Cite
Copyright: Yang et al. This is an open‐access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
It remains unclear how exercise, as an entropic event, brings benefit against human aging. Here we examined longitudinal changes of p16Ink4a+ senescent cells in skeletal muscle of young men (aged 22.5±1.7 y) before and after resistance exercise (0 h and 48 h) with multiple biopsies at two different protein availabilities: low protein (14%) and isocaloric high protein (44%) supplemented conditions. Immunohistochemistry analysis of muscle cross-sections using p16Ink4a and CD34 antibodies confirmed that the detected senescent cells were endothelial progenitor cells. Leukocyte infiltration into skeletal muscle increased during resistance exercise. The senescent cells in muscle decreased (-48%, P < 0.01) after exercise for 48 h. Low protein supplementation resulted in greater infiltrations of both CD68+ phagocytic macrophage and leukocyte, further decreased p16Ink4a+ senescent cells (-73%, P < 0.001), and delayed increases in regenerative CD163+ macrophage in skeletal muscle, compared with high protein supplemented condition. Significant gain in muscle mass after 12 weeks of training occurred only under high protein supplemented condition. Conclusion: Rapid senescent cell clearance of human skeletal muscle during resistance exercise seems to associate with enhanced in situ phagocytosis. High protein availability accelerates resolution of muscle inflammation and promotes muscle increment after training.