Global gene expression in skeletal muscle from well-trained strength and endurance athletes.
OBJECTIVE
We used gene microarray analysis to compare the global expression profile of genes involved in adaptation to training in skeletal muscle from chronically strength-trained (ST), endurance-trained (ET), and untrained control subjects (Con).


METHODS
Resting skeletal muscle samples were obtained from the vastus lateralis of 20 subjects (Con n = 7, ET n = 7, ST n = 6; trained [TR] groups >8 yr specific training). Total RNA was extracted from tissue for two color microarray analysis and quantative (Q)-PCR. Trained subjects were characterized by performance measures of peak oxygen uptake (V x O 2peak) on a cycle ergometer and maximal concentric and eccentric leg strength on an isokinetic dynamometer.


RESULTS
Two hundred and sixty-three genes were differentially expressed in trained subjects (ET + ST) compared with Con (P < 0.05), whereas 21 genes were different between ST and ET (P < 0.05). These results were validated by reverse transcriptase polymerase chain reaction for six differentially regulated genes (EIFSJ, LDHB, LMO4, MDH1, SLC16A7, and UTRN. Manual cluster analyses revealed significant regulation of genes involved in muscle structure and development in TR subjects compared with Con (P <or= 0.05) and expression correlated with measures of performance (P < 0.05). ET had increased whereas ST had decreased expression of gene clusters related to mitochondrial/oxidative capacity (P <or= 0.05). These mitochondrial gene clusters correlated with V x O 2peak (P < 0.05). V x O 2peak also correlated with expression of gene clusters that regulate fat and carbohydrate oxidation (P < 0.05).


CONCLUSIONS
We demonstrate that chronic training subtly coregulates numerous genes from important functional groups that may be part of the long-term adaptive process to adapt to repeated training stimuli.
Stepto
Nigel K
NK
Department of Physiology, Monash University, Clayton, Victoria, Australia. nigel.stepto@vu.edu.au
Coffey
Vernon G
VG
Carey
Andrew L
AL
Ponnampalam
Anna P
AP
Canny
Benedict J
BJ
Powell
David
D
Hawley
John A
JA
D000222:Adaptation, Physiological; D000328:Adult; D001706:Biopsy; D016022:Case-Control Studies; D005080:Exercise Test; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D024101:Mitochondrial Proteins / Q000378:metabolism; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D010101:Oxygen Consumption; D010807:Physical Endurance; D010809:Physical Fitness; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D055070:Resistance Training; D013177:Sports; D015854:Up-Regulation
D024101:Mitochondrial Proteins; D012333:RNA, Messenger