Plasma MicroRNA Levels Differ between Endurance and Strength Athletes

• Published in: PloS one Vol. 10; no. 4; p. e0122107
• Main Authors: Wardle, Sophie L., Bailey, Mark E. S., Kilikevicius, Audrius, Malkova, Dalia, Wilson, Richard H., Venckunas, Tomas, Moran, Colin N.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 16.04.2015; Public Library of Science (PLoS)
• Subjects: Adaptation; Adult; Analysis; Athletes; Binding sites; Biomarkers; Body fat; Endurance; Exercise; Fitness training programs; Gene expression; Humans; Kinases; Life sciences; Metabolic response; MicroRNA; MicroRNAs; MicroRNAs - blood; miRNA; Muscles; Musculoskeletal system; Phenotypes; Physical fitness; Physical training; Physiology; Plasma; Regression analysis; Ribonucleic acid; RNA; Sports; Training; Young Adult; Glasgow Scotland; Scotland; United Kingdom > UK; Lithuania
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0122107

MicroRNAs (miRNAs) are stable in the circulation and are likely to function in inter-organ communication during a variety of metabolic responses that involve changes in gene expression, including exercise training. However, it is unknown whether differences in circulating-miRNA (c-miRNA) levels are characteristic of training modality. We investigated whether levels of candidate c-miRNAs differ between elite male athletes of two different training modalities (n = 10 per group)--endurance (END) and strength (STR)--and between these groups and untrained controls (CON; n = 10). Fasted, non-exercised, morning plasma samples were analysed for 14 c-miRNAs (miR-1, miR-16-2, miR-20a-1, miR-21, miR-93, miR-103a, miR-133a, miR-146a, miR-192, miR-206, miR-221, miR-222, miR-451, miR-499). Moreover, we investigated whether c-miRNA levels were associated with quantitative performance-related phenotypes within and between groups. miR-222 was present at different levels in the three participant groups (p = 0.028) with the highest levels being observed in END and the lowest in STR. A number of other c-miRNAs were present at higher levels in END than in STR (relative to STR, ± 1 SEM; miR-222: 1.94 fold (1.73-2.18), p = 0.011; miR-21: 1.56 fold (1.39-1.74), p = 0.013; miR-146a: 1.50 fold (1.38-1.64), p = 0.019; miR-221: 1.51 fold (1.34-1.70), p = 0.026). Regression analyses revealed several associations between candidate c-miRNA levels and strength-related performance measures before and after adjustment for muscle or fat mass, but not following adjustment for group. Certain c-miRNAs (miR-222, miR-21, miR-146a and miR-221) differ between endurance- and resistance-trained athletes and thus have potential as useful biomarkers of exercise training and / or play a role in exercise mode-specific training adaptations. However, levels of these c-miRNAs are probably unrelated to muscle bulk or fat reserves.