title: PGC-1α transcriptional response and mitochondrial adaptation to acute exercise is maintained in skeletal muscle of sedentary elderly males.
abstract: The aim of the present study was to examine the effects of ageing and training status on (1) markers of skeletal muscle mitochondrial content and (2) the ability to activate the acute signalling pathways associated with regulating exercise-induced mitochondrial biogenesis. Muscle biopsies were obtained from the vastus lateralis muscle of young untrained (24 ± 4 years, n = 6; YU), young trained (22 ± 3 years, n = 6; YT), old untrained (65 ± 6 years, n = 6; OU) and old trained (64 ± 3 years, n = 6; OT) healthy males before and after (3 h and 3 days post-exercise) completion of high-intensity interval cycling exercise. In resting muscle, lifelong training preserved mtDNA, PGC-1α and COXIV protein content such that muscles from OT individuals were comparable to muscles from both YU and YT individuals, whereas lifelong sedentary behaviour reduced such markers of mitochondrial content. Regardless of age or training status, acute exercise induced comparable increases in p38MAPK phosphorylation immediately post-exercise, PGC-1α and COXIV mRNA expression at 3 h post-exercise and COXIV protein at 3 days post-exercise. Data demonstrate that lifelong endurance training preserves skeletal muscle PGC-1α content and that despite the mitochondrial dysfunction typically observed with sedentary ageing, muscles from sedentary elderly individuals retain the capacity to activate the acute signalling pathways associated with regulating the early processes of mitochondrial biogenesis. We consider our data to have immediate translational potential as they highlight the potential therapeutic effects of exercise to induce skeletal muscle mitochondrial biogenesis persist late in adulthood, even after a lifetime of physical inactivity.
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool L3 3AF, UK.
authors.forename: J N
authors.initials: JN
authors.lastname: Cobley
authors.forename: J D
authors.initials: JD
authors.lastname: Bartlett
authors.forename: A
authors.initials: A
authors.lastname: Kayani
authors.forename: S W
authors.initials: SW
authors.lastname: Murray
authors.forename: J
authors.initials: J
authors.lastname: Louhelainen
authors.forename: T
authors.initials: T
authors.lastname: Donovan
authors.forename: S
authors.initials: S
authors.lastname: Waldron
authors.forename: W
authors.initials: W
authors.lastname: Gregson
authors.forename: J G
authors.initials: JG
authors.lastname: Burniston
authors.forename: J P
authors.initials: JP
authors.lastname: Morton
authors.forename: G L
authors.initials: GL
authors.lastname: Close
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001706:Biopsy; D004272:DNA, Mitochondrial / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D005080:Exercise Test / Q000379:methods*; D006360:Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000502:physiology*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010766:Phosphorylation; D005082:Physical Exertion / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D052097:Quadriceps Muscle / Q000378:metabolism / Q000473:pathology; D057185:Sedentary Behavior; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D004272:DNA, Mitochondrial; D006360:Heat-Shock Proteins; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D014157:Transcription Factors; D003576:Electron Transport Complex IV; D048051:p38 Mitogen-Activated Protein Kinases