1. Myonuclear accretion is a determinant of exercise-induced remodeling in skeletal muscle
- Author
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Chengyi Sun, Se-Jin Lee, Qingnian Goh, Alyssa A. W. Cramer, Taejeong Song, Sakthivel Sadayappan, Michael J. Petrany, and Douglas P. Millay
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Satellite Cells, Skeletal Muscle ,Mouse ,QH301-705.5 ,Science ,Exercise intolerance ,General Biochemistry, Genetics and Molecular Biology ,Interval training ,Muscle hypertrophy ,myomaker ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Fibrosis ,Physical Conditioning, Animal ,Internal medicine ,medicine ,Animals ,muscle hypertrophy ,Progenitor cell ,Biology (General) ,Muscle, Skeletal ,Cell fusion ,cell fusion ,General Immunology and Microbiology ,exercise ,Muscle adaptation ,business.industry ,General Neuroscience ,Skeletal muscle ,Hypertrophy ,General Medicine ,medicine.disease ,Adaptation, Physiological ,Stem Cells and Regenerative Medicine ,030104 developmental biology ,Endocrinology ,medicine.anatomical_structure ,myonuclear accretion ,Medicine ,medicine.symptom ,Research Advance ,business ,030217 neurology & neurosurgery ,Developmental Biology - Abstract
Skeletal muscle adapts to external stimuli such as increased work. Muscle progenitors (MPs) control muscle repair due to severe damage, but the role of MP fusion and associated myonuclear accretion during exercise are unclear. While we previously demonstrated that MP fusion is required for growth using a supra-physiological model (Goh and Millay, 2017), questions remained about the need for myonuclear accrual during muscle adaptation in a physiological setting. Here, we developed an 8 week high-intensity interval training (HIIT) protocol and assessed the importance of MP fusion. In 8 month-old mice, HIIT led to progressive myonuclear accretion throughout the protocol, and functional muscle hypertrophy. Abrogation of MP fusion at the onset of HIIT resulted in exercise intolerance and fibrosis. In contrast, ablation of MP fusion 4 weeks into HIIT, preserved exercise tolerance but attenuated hypertrophy. We conclude that myonuclear accretion is required for different facets of exercise-induced adaptive responses, impacting both muscle repair and hypertrophic growth.
- Published
- 2019