Transcriptional control, but not subcellular location, of PGC-1α is altered following exercise in a hot environment

J Appl Physiol (1985). 2016 Sep 1;121(3):741-9. doi: 10.1152/japplphysiol.01065.2015. Epub 2016 Jul 21.


The purpose of this study was to determine mitochondrial biogenesis-related mRNA expression, binding of transcription factors to the peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC-1α) promoter, and subcellular location of PGC-1α protein in human skeletal muscle following exercise in a hot environment compared with a room temperature environment. Recreationally trained males (n = 11) completed two trials in a temperature- and humidity-controlled environmental chamber. Each trial consisted of cycling in either a hot (H) or room temperature (C) environment (33 and 20°C, respectively) for 1 h at 60% of maximum wattage (Wmax) followed by 3 h of supine recovery at room temperature. Muscle biopsies were taken from the vastus lateralis pre-, post-, and 3 h postexercise. PGC-1α mRNA increased post (P = 0.039)- and 3 h postexercise in C (P = 0.002). PGC-1α, estrogen-related receptor-α (ERRα), and nuclear respiratory factor 1 (NRF-1) mRNA was all lower in H than C post (P = 0.038, P < 0.001, and P = 0.030, respectively)- and 3 h postexercise (P = 0.035, P = 0.007, and P < 0.001, respectively). Binding of cAMP response element-binding protein (CREB) (P = 0.005), myocyte enhancer factor 2 (MEF2) (P = 0.047), and FoxO forkhead box class-O1 (FoxO1) (P = 0.010) to the promoter region of the PGC-1α gene was lower in H than C. Nuclear PGC-1α protein increased postexercise in both H and C (P = 0.029) but was not different between trials (P = 0.602). These data indicate that acute exercise in a hot environment blunts expression of mitochondrial biogenesis-related mRNA, due to decreased binding of CREB, MEF2, and FoxO1 to the PGC-1α promoter.

Keywords: heat stress; mitochondrial biogenesis; skeletal muscle.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Active Transport, Cell Nucleus / physiology
  • Adult
  • Ecosystem
  • Exercise / physiology*
  • Heat-Shock Response / physiology*
  • Hot Temperature
  • Humans
  • Male
  • Middle Aged
  • Mitochondria, Muscle / physiology*
  • Subcellular Fractions / metabolism*
  • Thermotolerance / physiology*
  • Transcriptional Activation / physiology*
  • Young Adult