Background: PERM1 has been identified as a key regulator of muscle energy metabolism, contractile function, and mitochondrial biogenesis. Objectives: To investigate the impact fasting and acute and chronic high-intensity exercise on p38MAPK, pCaMKII, PGC-1α, ERRα, and PERM1 and on PERM1 target genes (CKMT2, GLUT4, and SIRT3) in human skeletal muscle. Methods: We performed secondary analyses of muscle biopsy samples from two previously published studies, and from one unpublished study. Muscle biopsies were analyzed from the following protocols: 1) nine men pre-, during, and post- an 8 hour fast with or without two hours of arm ergometer exercise; 2) nine men and eight women pre- and 3 hours post- acute high-intensity interval cycling exercise (HIIE); and 3) eleven men and eight women pre- and post- a 6-week period of high-intensity interval training (HIIT) or non-exercise control. We used RT-PCR and western blotting to determine the mRNA and protein levels, respectively. Immunolabelling, microscopy, and subcellular fractionation were also performed to assess PERM1 cellular localization. Results: Fasting did not induce detectable changes in the PERM1-related pathways. HIIE significantly increased p-p38MAPK (p<0.05, d=1.27) protein, and PERM1 (p<0.05, d=0.781) and PGC-1α (p<0.05, d=1.51) mRNA. Six weeks of HIIT increased the protein levels of PERM1 isoform 2 (p<0.05, ƞ2=0.168) and CKMT2 (p<0.05, ƞ2=0.226). PERM1 was localized in the perinuclear region and enriched in the mitochondria. Conclusions: Our results suggest that only some components of PERM1-related pathways are preserved in human skeletal muscle, highlighting the importance of future studies examining PERM1 function in humans.
Menezes et al. (Fri,) studied this question.