title: Transcriptome and translational signaling following endurance exercise in trained skeletal muscle: impact of dietary protein.
abstract: Postexercise protein feeding regulates the skeletal muscle adaptive response to endurance exercise, but the transcriptome guiding these adaptations in well-trained human skeletal muscle is uncharacterized. In a crossover design, eight cyclists ingested beverages containing protein, carbohydrate and fat (PTN: 0.4, 1.2, 0.2 g/kg, respectively) or isocaloric carbohydrate and fat (CON: 1.6, 0.2 g/kg) at 0 and 1 h following 100 min of cycling. Biopsies of the vastus lateralis were collected at 3 and 48 h following to determine the early and late transcriptome and regulatory signaling responses via microarray and immunoblot. The top gene ontology enriched by PTN were: muscle contraction, extracellular matrix--signaling and structure, and nucleoside, nucleotide, and nucleic acid metabolism (3 and 48 h); developmental processes, immunity, and defense (3 h); glycolysis, lipid and fatty acid metabolism (48 h). The transcriptome was also enriched within axonal guidance, actin cytoskeletal, Ca2+, cAMP, MAPK, and PPAR canonical pathways linking protein nutrition to exercise-stimulated signaling regulating extracellular matrix, slow-myofibril, and metabolic gene expression. At 3 h, PTN attenuated AMPKα1Thr172 phosphorylation but increased mTORC1Ser2448, rps6Ser240/244, and 4E-BP1-γ phosphorylation, suggesting increased translation initiation, while at 48 h AMPKα1Thr172 phosphorylation and PPARG and PPARGC1A expression increased, supporting the late metabolic transcriptome, relative to CON. To conclude, protein feeding following endurance exercise affects signaling associated with cell energy status and translation initiation and the transcriptome involved in skeletal muscle development, slow-myofibril remodeling, immunity and defense, and energy metabolism. Further research should determine the time course and posttranscriptional regulation of this transcriptome and the phenotype responding to chronic postexercise protein feeding.
authors: School of Sport and Exercise and Institute of Food Nutrition and Human Health, Massey University, Wellington, New Zealand. d.s.rowlands@massey.ac.nz
authors: David S
authors: DS
authors: Rowlands
authors: Jasmine S
authors: JS
authors: Thomson
authors: Brian W
authors: BW
authors: Timmons
authors: Frédéric
authors: F
authors: Raymond
authors: Andreas
authors: A
authors: Fuerholz
authors: Robert
authors: R
authors: Mansourian
authors: Marie-Camille
authors: MC
authors: Zwahlen
authors: Sylviane
authors: S
authors: Métairon
authors: Elisa
authors: E
authors: Glover
authors: Trent
authors: T
authors: Stellingwerff
authors: Martin
authors: M
authors: Kussmann
authors: Mark A
authors: MA
authors: Tarnopolsky
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D004044:Dietary Proteins / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D015444:Exercise / Q000502:physiology*; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007328:Insulin / Q000097:blood; D008297:Male; D000076222:Mechanistic Target of Rapamycin Complex 1; D008954:Models, Biological; D046912:Multiprotein Complexes; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D010766:Phosphorylation / Q000187:drug effects; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D058570:TOR Serine-Threonine Kinases; D059467:Transcriptome / Q000187:drug effects / Q000235:genetics
chemical_list: D001786:Blood Glucose; D004044:Dietary Proteins; D007328:Insulin; D046912:Multiprotein Complexes; D011506:Proteins; D006003:Glycogen; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; C526180:PRKAA1 protein, human