title: Improved knee extensor strength with resistance training associates with muscle specific miRNAs in older adults.
abstract: Regular exercise, particularly resistance training (RT), is the only therapy known to consistently improve muscle strength and quality (force per unit of mass) in older persons, but there is considerable variability in responsiveness to training. Identifying sensitive diagnostic biomarkers of responsiveness to RT may inform the design of a more efficient exercise regimen to improve muscle strength in older adults. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. We quantified six muscle specific miRNAs (miR-1, -133a, -133b, -206, -208b and -499) in both muscle tissue and blood plasma, and their relationship with knee extensor strength in seven older (age=70.5 ± 2.5 years) adults before and after 5 months of RT. MiRNAs differentially responded to RT; muscle miR-133b decreased, while all plasma miRNAs tended to increase. Percent changes in knee extensor strength with RT showed strong positive correlations with percent changes in muscle miR-133a, -133b, and -206 and with percent changes in plasma and plasma/muscle miR-499 ratio. Baseline level of plasma or plasma/muscle miR-499 ratio further predicts muscle response to RT, while changes in muscle miR-133a, -133b, and -206 may correlate with muscle TNNT1 gene alternative splicing in response to RT. Our results indicate that RT alters muscle specific miRNAs in muscle and plasma, and that these changes account for some of the variation in strength responses to RT in older adults.
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States; J Paul Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States.
authors.forename: Tan
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States.
authors.forename: Alexander
authors.initials: A
authors.lastname: Birbrair
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States.
authors.forename: Zhong-Min
authors.initials: ZM
authors.lastname: Wang
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States.
authors.forename: María L
authors.initials: ML
authors.lastname: Messi
authors.affiliation: Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC 27109, United States.
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Marsh
authors.affiliation: Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States.
authors.forename: Iris
authors.initials: I
authors.lastname: Leng
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States; J Paul Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States.
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Nicklas
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States; J Paul Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, NC 27157, United States. Electronic address: odelbono@wakehealth.edu.
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Delbono
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017398:Alternative Splicing; D001823:Body Composition / Q000502:physiology; D015444:Exercise / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D035683:MicroRNAs / Q000096:biosynthesis* / Q000097:blood; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D055070:Resistance Training / Q000379:methods*; D020107:Troponin T / Q000235:genetics
chemical_list: D035683:MicroRNAs; D020107:Troponin T
keywords: Aging; MicroRNA; Resistance training; Skeletal muscle