Effects Of A Low-Intensity Resistance Exercise Program On Serum Mir-630, Mir-5703, And Fractalkine/Cx3cl1 Expressions In Subjects With No Exercise Habits: A Preliminary Study

Aims: Exercise is effective for the prevention of liver cancer. Exercise exerts biological effects through the regulation of microRNAs (miRNAs) and cytokines/myokines. We aimed to investigate the effects of low-intensity resistance exercise on serum miRNA and cytokine/myokine expressions in subjects with no exercise habits.Methods: We enrolled seven male subjects with no exercise habits in this prospective before-after study. All subjects performed a low-intensity resistance exercise program (three metabolic equivalents, approximately 20 min/session). Serum miRNA expressions were evaluated using microarrays. We performed Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of differentially expressed miRNAs before and after exercise. Serum cytokine/myokine expressions were evaluated using a multiplex panel.Results: All subjects completed the exercise program with no adverse events. In the microarray analysis, seven miRNAs showed a significant change between before and after exercise. Of these, microRNA (miR)-630 and miR-5703 showed a >1.5-fold increase (miR-630: 40.7 vs. 69.3 signal intensity, p = 0.0133; miR-5703: 30.7 vs. 55.9 signal intensity, p = 0.0051). KEGG pathway enrichment analysis showed that miR-630- and miR-5703-related genes were enriched in 37 and 5 pathways, including transforming growth factor-beta and Wnt signaling pathways, respectively. In the multiplex analysis, 12 cytokines/myokines showed significant alteration after exercise compared to before exercise. Of these, fractalkine/CX3CL1 showed the most significant up-regulation by exercise (94.5 vs. 109.1 pg/ml, p = 0.0017).Conclusions: A low-intensity resistance exercise program was associated with upregulation of serum miR-630, miR-5703, and fractalkine/CX3CL1 expressions in subjects with no exercise habits. Thus, even low-intensity exercise may alter miRNA and cytokine/myokine expressions in humans.