p53 Regulation of Mitochondrial Biogenesis in Skeletal Muscle

Mitochondria are dynamic organelles that produce energy for the cell. In skeletal muscle, mitochondria adapt as a result of regular exercise by increasing their content and improving their function, resulting in better muscle energy production. p53 is a protein that maintains basal mitochondria function in muscle. However, it is unknown whether it is required for skeletal muscle adaptations with exercise. We thus subjected normal, wild-type mice, as well as those with a specific p53 deletion within muscle, to a 6-week endurance training program. Our results confirm that p53 is required for mitochondrial maintenance in muscle under basal conditions, but that it is not required for the adaptive responses in mitochondrial content and function observed with training. This suggests that exercise can activate viable alternative compensatory pathways to maintain muscle health in the absence of p53.