Browsing by Author "Lamb, Donald A"

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    Acute and chronic effects of resistance training on skeletal muscle markers of mitochondrial remodeling in older adults
    (Physiological Reports, 2020-08) Mesquita, Paulo HC; Lamb, Donald A; Parry, Hailey A; Moore, Johnathon H; Smith, Morgan A; Vann, Christopher G; Osburn, Shelby C; Fox, Carlton D; Ruple, Bradley A; Huggins, Kevin W; Fruge, Andrew D; Young, Kaelin C; Kavazis, Andreas N; Roberts, Michael D
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    Effects of Resistance Training on the Redox Status of Skeletal Muscle in Older Adults
    (Antioxidants) Mesquita, Paulo HC; Lamb, Donald A; Godwin, Joshua S; Osburn, Shelby C; Ruple, Bradley A; Moore, Johnathon H; Vann, Christopher G; Huggins, Kevin W; Fruge, Andrew D; Young, Kaelin C; Kavazis, Andreas N; Roberts, Michael D
    The aim of this study was to investigate the effects of resistance training (RT) on the redox status of skeletal muscle in older adults. Thirteen males aged 64 ± 9 years performed full-body RT 2x/week for 6 weeks. Muscle biopsies were obtained from the vastus lateralis prior to and following RT. The mRNA, protein, and enzymatic activity levels of various endogenous antioxidants were determined. In addition, skeletal muscle 4-hydroxynonenal and protein carbonyls were determined as markers of oxidative damage. Protein levels of heat shock proteins (HSPs) were also quantified. RT increased mRNA levels of all assayed antioxidant genes, albeit protein levels either did not change or decreased. RT increased total antioxidant capacity, catalase, and glutathione reductase activities, and decreased glutathione peroxidase activity. Lipid peroxidation also decreased and HSP60 protein increased following RT. In summary, 6 weeks of RT decreased oxidative damage and increased antioxidant enzyme activities. Our results suggest the older adult responses to RT involve multi-level (transcriptional, post-transcriptional, and post-translational) control of the redox status of skeletal muscle.
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    Resistance training increases muscle NAD+ and NADH concentrations as well as NAMPT protein levels and global sirtuin activity in middle-aged, overweight, untrained individuals
    (Aging, 2020-05-05) Lamb, Donald A; Moore, Johnathon H; Mesquita, Paulo Henrique Caldeira; Smith, Morgan A; Vann, Christopher G; Osburn, Shelby C; Fox, Carlton D; Lopez, Hector L; Ziegenfuss, Tim N; Huggins, Kevin W; Goodlett, Michael D; Fruge, Andrew D; Kavazis, Andreas N; Young, Kaelin C; Roberts, Michael D
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    Resistance training rejuvenates the mitochondrial methylome in aged human skeletal muscle
    (The FASEB Journal, 2021-09) Ruple, Bradley A; Godwin, Joshua S; Mesquita, Paulo HC; Osburn, Shelby C; Vann, Christopher G; Lamb, Donald A; Sexton, Casey L; Candow, Darren G; Forbes, Scott C; Frugé, Andrew D; Kavazis, Andreas N; Young, Kaelin C; Seaborne, Robert A; Sharples, Adam P; Roberts, Michael D
    AbstractResistance training (RT) dynamically alters the skeletal muscle nuclear DNA methylome. However, no study has examined if RT affects the mitochondrial DNA (mtDNA) methylome. Herein, ten older, Caucasian untrained males (65 ± 7 y.o.) performed six weeks of full‐body RT (twice weekly). Body composition and knee extensor torque were assessed prior to and 72 h following the last RT session. Vastus lateralis (VL) biopsies were also obtained. VL DNA was subjected to reduced representation bisulfite sequencing providing excellent coverage across the ~16‐kilobase mtDNA methylome (254 CpG sites). Biochemical assays were also performed, and older male data were compared to younger trained males (22 ± 2 y.o., n = 7, n = 6 Caucasian & n = 1 African American). RT increased whole‐body lean tissue mass (p = .017), VL thickness (p = .012), and knee extensor torque (p = .029) in older males. RT also affected the mtDNA methylome, as 63% (159/254) of the CpG sites demonstrated reduced methylation (p < .05). Several mtDNA sites presented a more “youthful” signature in older males after RT in comparison to younger males. The 1.12 kilobase mtDNA D‐loop/control region, which regulates replication and transcription, possessed enriched hypomethylation in older males following RT. Enhanced expression of mitochondrial H‐ and L‐strand genes and complex III/IV protein levels were also observed (p < .05). While limited to a shorter‐term intervention, this is the first evidence showing that RT alters the mtDNA methylome in skeletal muscle. Observed methylome alterations may enhance mitochondrial transcription, and RT evokes mitochondrial methylome profiles to mimic younger men. The significance of these findings relative to broader RT‐induced epigenetic changes needs to be elucidated.
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    The effects of resistance training with or without peanut protein supplementation on skeletal muscle and strength adaptations in older individuals
    (Journal of the International Society of Sports Nutrition, 2020-01-03) Lamb, Donald A; Moore, Johnathon H; Smith, Morgan A; Vann, Christopher G; Osburn, Shelby C; Ruple, Bradley A; Fox, Carlton D; Smith, Kristen S; Altonji, Olivia M; Power, Zade M; Cerovsky, Annsley E; Ross, C Owen; Cao, Andy T; Goodlett, Michael D; Huggins, Kevin W; Fruge, Andrew D; Young, Kaelin C; Roberts, Michael D