We have recently shown that heat stress induces mitochondrial adaptations in skeletal muscles. However, its underlying mechanisms have been still unclear. We herein examined whether PGC-1α, a master regulator of mitochondrial biogenesis, mediates heat stress-induced mitochondrial adaptations. Heat stress (exposing mice into a hot environment, 40ºC, 30 min/day, 7 days) up-regulated mitochondrial content (increase in CS activity and OXPHOS subunit proteins), and respiratory function (an increase in oxygen consumption rate and a decrease in H2O2 emission during state 3 respiration) in gastrocnemius muscle. However, PGC-1α knockdown (forced expression of shRNA against PGC-1α) attenuated these mitochondrial adaptations with heat stress. Our several sets of the experiment indicate that heat stress-induced mitochondrial adaptations were, at least in part, mediated by PGC-1α.
