Plasma MicroRNA Levels Differ between Endurance and Strength Athletes

Abstract

AimMicroRNAs (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.MethodsWe 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.ResultsmiR-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.ConclusionCertain 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.

Biology of Stress and Physical Performance

“…It has been proven that the presence of the D allele increases the ejection fraction and the pulmonary systolic blood pressure [47], in addition to increasing the CRF and ACTH levels of the HPA axis [45]. Recent evidence shows that triathletes who competed in the ironman of South Africa who had higher levels of plasma ECA had a lower performance on the cycling and jogging tests [49].…”

“…They play an important role in postranscriptional regulation through direct binding with messenger RNAs (mRNA). Currently, several reports relate the regulation exerted by miRNAs on the phenotypic characteristics of skeletal muscle and their participation in the conditioning factors of athletic performance in athletes who practice long-distance sports [49].…”

The Role of MicroRNAs in the Cardiac Response to Exercise

“…Sawada et al (2013) reported that miR-149 Ã increased, whereas miR146a and -221 decreased in human serum 3 days after acute resistance exercise. Changes in circulating miRNAs levels appear to depend on the type of exercise, as Wardle et al (2015) found that elite endurance athletes had higher plasma miR-222 levels than sedentary controls while elite strength athletes had lower levels, and Uhlemann et al (2014) found that circulating miR-126 increased in response to endurance but not resistance training. Studies of alterations in plasma or serum miRNA in response to exercise have thus far been confined in humans.…”

Regulation of Gene Expression by Exercise-Related Micrornas

“…Physical exercise induced-MiRs, muscle hypertrophy, and endurance adaptation Aerobic physical exercise increases circulating (plasma or serum) levels of mir-1, mir20a, mir-21, mir-133a, mir-146a, mir-150, mir-206, mir-221, and mir-222, and decreases mir-486 in humans [94][95][96][97][98]. However, studies concerning direct effects of specific plasma or serum miRs on exercise performance and physiological responses are scarce and very limited.…”