Changes in ubiquitin proteasome pathway gene expression in skeletal muscle with exercise and statins.

OBJECTIVE: Statins are safe medications but have side effects including myalgia and rhabdomyolysis. How statins provoke muscle damage is not known, but this effect is exacerbated by exercise.

METHODS AND RESULTS: Healthy subjects took Atorvastatin (80 mg/daily) or placebo for 4 weeks. Biopsies of both vastus lateralis muscles were performed 8 hours after eccentric exercise (known to result in muscle soreness and damage) of the left leg at baseline and the right leg after statin/placebo treatment. Gene expression was determined using Affymetrix GeneChips, and selected genes confirmed by polymerase chain reaction (qRT-PCR). Atorvastatin had little effect on gene expression at rest. When combined with exercise, 56 genes were differentially expressed with 18% involved in the ubiquitin proteasome pathway (UPP) and 20% involved in protein folding and catabolism, and apoptosis.

CONCLUSIONS: This is the first investigation to our knowledge to implicate involvement of the UPP in skeletal muscle in response to combined exercise and statin treatment, possibly explaining the onset of myalgia with exertion. Statins may alter the response of muscle to exercise stress by altering the action of the UPP, protein folding, and catabolism, disrupting the balance between protein degradation and repair.