title: Muscle specific microRNAs are regulated by endurance exercise in human skeletal muscle.
abstract: Muscle specific miRNAs, myomiRs, have been shown to control muscle development in vitro and are differentially expressed at rest in diabetic skeletal muscle. Therefore, we investigated the expression of these myomiRs, including miR-1, miR-133a, miR-133b and miR-206 in muscle biopsies from vastus lateralis of healthy young males (n = 10) in relation to a hyperinsulinaemic–euglycaemic clamp as well as acute endurance exercise before and after 12 weeks of endurance training. The subjects increased their endurance capacity, VO2max (l min−1) by 17.4% (P < 0.001), and improved insulin sensitivity by 19% (P < 0.01). While myomiR expression remained stable during a hyperinsulinaemic–euglycaemic clamp, an acute bout of exercise increased mir-1 (P < 0.05) and mir-133a (P < 0.05) expression before, but not after, training. In resting biopsies, endurance training for 12 weeks decreased basal expression of all four myomiRs (P < 0.05). Interestingly, all myomiRs reverted to their pre-training expression levels 14 days after ceasing the training programme. Components of major pathways involved in endurance adaptation such as MAPK and TGF-β were predicted to be targeted by the myomiRs examined. Tested predicted target proteins included Cdc42 and ERK 1/2. Although these proteins were downregulated between post-training period and 2 weeks of cessation, an inverse correlation between myomiR and target proteins was not found. In conclusion, our data suggest myomiRs respond to physiological stimuli, but their role in regulating human skeletal muscle adaptation remains unknown.
authors: The Centre of Inflammation and Metabolism, Department of Infectious Diseases and CMRC, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Denmark. soren_nielsen@inflammation-metabolism.dk
authors: Søren
authors: S
authors: Nielsen
authors: Camilla
authors: C
authors: Scheele
authors: Christina
authors: C
authors: Yfanti
authors: Thorbjörn
authors: T
authors: Akerström
authors: Anders R
authors: AR
authors: Nielsen
authors: Bente K
authors: BK
authors: Pedersen
authors: Matthew J
authors: MJ
authors: Laye
authors: Matthew
authors: M
authors: Laye
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015153:Blotting, Western; D001823:Body Composition / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D015309:Glucose Clamp Technique; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D035683:MicroRNAs