Human Skeletal Muscle Mitochondrial Related Gene Expression After Exposure to Different Environmental Temperatures.

Abstract

Recent research has reported an effect of environmental temperature on the exercise stimulated response of several genes related to skeletal muscle mitochondrial biogenesis in humans. However, the previous research has not addressed the impact of environmental temperature, independent of exercise. PURPOSE: To determine the effects of acute hot and cold exposure on skeletal muscle gene expression related to mitochondrial biogenesis in humans. METHODS: Recreationally trained male subjects (n =11, age 27 ± 5, height 183 ± 5 cm, weight 84.1 ± 13.0 kg) had skeletal muscle biopsies taken from the vastus lateralis after 3 hours of sitting in an environmentally controlled chamber in either cold (C), room temperature (RT), or hot (H) conditions (7°C, 20°C, 33°C, respectively). RESULTS: Core temperature was significantly higher in H and C compared to RT (37.2 ± 0.1°C, p = 0.001; 37.1 ± 0.1°C, p = 0.013; 36.9 ± 0.1°C, respectively). Whole body oxygen consumption was significantly higher in H and C compared to RT (0.38 ± 0.01 L·min-1, p < 0.001; 0.52 ± 0.03 L·min-1, p = 0.001; 0.35 ± 0.01 L·min-1, respectively). There was no difference in the gene expression of ERRα (p = 0.665), GABPA (p = 0.080), MEF2A (p = 0.630), NRF1 (p = 0.651), PGC1α (p = 0.612), SIRT1 (p = 0.080), TFAM (p = 0.890), or VEGF (p = 0.080) between H, C, and RT. CONCLUSIONS: Temperature exposure alone does not elicit significant changes in gene expression related to mitochondrial biogenesis. When considered in conjunction with previous research, exercise appears to be a necessary component to observe gene expression alterations between different environmental temperatures in humans. Funded by National Institute of General Medical Sciences of the National Institutes of Health, Centers of Biomedical Research Excellence (P20GM109090).