PGC-1beta is downregulated by training in human skeletal muscle: no effect of training twice every second day vs. once daily on expression of the PGC-1 family.
We hypothesized that the peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) family of transcriptional coactivators (PGC-1alpha, PGC-1beta, and PRC) is differentially regulated by training once daily vs. training twice daily every second day and that this difference might be observed in the acute response to endurance exercise. Furthermore, we hypothesized that expression levels of the PGC-1 family differ with muscular fiber-type composition. Thus, before and after 10 wk of knee extensor endurance training, training one leg once daily and the other leg twice daily every second day, keeping the total amount of training for the legs equal, skeletal muscle mRNA expression levels of PGC-1alpha, PGC-1beta, and PRC were determined in young healthy men (n = 7) in response to 3 h of acute exercise. No significant difference was found between the two legs, suggesting that regulation of the PGC-1 family is independent of training protocol. Training decreased PGC-1beta in both legs, whereas PGC-1alpha was increased, but not significantly, in the leg training once daily. PRC did not change with training. Both PGC-1alpha and PRC were increased by acute exercise both before and after endurance training, whereas PGC-1beta did not change. The mRNA levels of the PGC-1 family were examined in different types of human skeletal muscle (triceps, soleus, and vastus lateralis; n = 7). Only the expression level of PGC-1beta differed and correlated inversely with percentage of type I fibers. In conclusion, there was no difference between training protocols on the acute exercise and training response of the PGC-1 family. However, training caused a decrease in PGC-1beta mRNA levels.
Mortensen
Ole Hartvig
OH
Centre of Inflammation and Metabolism, Department of Infectious Diseases, Rigshospitalet 7641, Blegdamsvej 9, DK-2100 Copenhagen, Denmark. ole@hartvig.org
Plomgaard
Peter
P
Fischer
Christian P
CP
Hansen
Anne K
AK
Pilegaard
Henriette
H
Pedersen
Bente Klarlund
BK
D000222:Adaptation, Physiological / Q000235:genetics; D000328:Adult; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D015444:Exercise / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010807:Physical Endurance / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism
D002352:Carrier Proteins; D006360:Heat-Shock Proteins; C486497:PPARGC1A protein, human; C455622:PPARGC1B protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D014157:Transcription Factors; C111264:peroxisome-proliferator-activated receptor-gamma coactivator-1