title: Resistance Training Enhances Skeletal Muscle Innervation Without Modifying the Number of Satellite Cells or their Myofiber Association in Obese Older Adults.
abstract: Studies in humans and animal models provide compelling evidence for age-related skeletal muscle denervation, which may contribute to muscle fiber atrophy and loss. Skeletal muscle denervation seems relentless; however, long-term, high-intensity physical activity appears to promote muscle reinnervation. Whether 5-month resistance training (RT) enhances skeletal muscle innervation in obese older adults is unknown. This study found that neural cell-adhesion molecule, NCAM+ muscle area decreased with RT and was inversely correlated with muscle strength. NCAM1 and RUNX1 gene transcripts significantly decreased with the intervention. Type I and type II fiber grouping in the vastus lateralis did not change significantly but increases in leg press and knee extensor strength inversely correlated with type I, but not with type II, fiber grouping. RT did not modify the total number of satellite cells, their number per area, or the number associated with specific fiber subtypes or innervated/denervated fibers. Our results suggest that RT has a beneficial impact on skeletal innervation, even when started late in life by sedentary obese older adults.
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine and J Paul Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: María Laura
authors.initials: ML
authors.lastname: Messi
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine and J Paul Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine and J Paul Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Zhong-Min
authors.initials: ZM
authors.lastname: Wang
authors.affiliation: Department of Health and Exercise Science, Wake Forest University, Winston-Salem, North Carolina.
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Marsh
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine and J Paul Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Barbara
authors.initials: B
authors.lastname: Nicklas
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine and J Paul Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, North Carolina. odelbono@wakehealth.edu.
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Delbono
mesh_terms: D000368:Aged; D019002:CD56 Antigen / Q000378:metabolism; D050676:Core Binding Factor Alpha 2 Subunit / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D018656:Muscle Fibers, Fast-Twitch; D018657:Muscle Fibers, Slow-Twitch; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000294:innervation*; D009657:North Carolina; D009765:Obesity / Q000503:physiopathology*; D055070:Resistance Training / Q000379:methods*; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology*
chemical_list: D019002:CD56 Antigen; D050676:Core Binding Factor Alpha 2 Subunit; C522918:NCAM1 protein, human; C493728:RUNX1 protein, human
keywords: Aging; Denervation; Exercise; Satellite Cells; Skeletal Muscle