Resistance Exercise Produces A Metabolic Gene Expression Signature Similar To Endurance Exercise

Abstract

Resistance training (RT) has been proposed as a beneficial intervention modality for patients with metabolic syndrome and type II diabetes because of increasing evidence that similar metabolic benefits may be achieved with RT as with endurance training. Much of the improvements resulted from exercise training are associated with transient modifications in skeletal muscle induced by an acute bout of exercise. PURPOSE: to examine the transcriptional regulation of metabolic genes in skeletal muscle induced by an acute bout of resistance exercise (RE). METHODS: Subjects (11 female and 12 male, 18 to 40 y) trained the non-dominant elbow flexors for 12 weeks resulting in a 14.2 +/- 6.2 % increase in muscle volume and a 59.7 +/- 20.4% increase in 1RM strength. Six days after the last exercise session, an acute bout of RE was performed and bilateral biopsies were taken 4 hr post-exercise from both the trained and the untrained arms. RNA was extracted and prepared for expression profiling using the Affymetrix Human Genome U133 Plus 2 chips. Absolute expression values were calculated using MAS.5 and dChip and analysis was carried out using Gene Spring. RESULTS: RE induced augmented mRNA levels of regulators implicated in 1) mitochondrial biogenesis including PGC1-a (↑2.88, p=0.0015), SIRT1(↑1.25, p=0.0152) and PRKAG2 (↑4.80, p=0.0009); 2) insulin signaling including IRS2 (↑3.42, p=0.0010), RRAD (↑5.01, p=0.0007) and NR4A1 (↑4.48, p=0.0020); and 3) capillary biogenesis including VEGF (↑1.85, p=0.0027), HIF1A (↑1.67, p=0.0004) and CYR61 (↑3.02, p=0.0045). Transcriptional modification of key lipid metabolism genes favored fatty acid repartitioning towards esterification with mRNA levels for LPL and CPT1B being decreased (LPL, ↓1.71 fold, p=0.0001; CPT1B, ↓1.42 fold, p=0.0246), and for FABPs being increased (FABP4, ↑1.56 fold, p=0.0003; FABP5, ↑1.50, p=0.0065). CONCLUSION: Similar to endurance exercise, acute RE exhibits favorable regulation of metabolic gene transcription in skeletal muscle, implying, in part, an explanation for the beneficial role of resistance training in treating metabolic disturbances.