Circulating microRNAs in Response to Exercise Training in Healthy Adults

Abstract

Circulating microRNAs (miRNAs, miRs) have great potential as cardiac biomarkers and they are also being explored for their roles in intercellular communication and gene expression regulation. The analysis of circulating miRNAs in response to exercise would provide a deeper understanding of the molecular response to physical activity and valuable information for clinical practice. Here, eight male college students were recruited to participate in cardiopulmonary exercise testing (CPET) and 1 h acute exercise training (AET). Blood samples were collected and serum miRNAs involved in angiogenesis, inflammation and enriched in muscle and/or cardiac tissues were analyzed before and after cardiopulmonary exercise and acute exercise. The miRNAs we detected were miR-1, miR-20a, miR-21, miR-126, miR-133a, miR-133b, miR-146, miR155, miR-208a, miR-208b, miR-210, miR-221, miR-222, miR-328, miR-378, miR-499, and miR-940. We found that serum miR-20a was decreased significantly after CPET and serum miR-21 was increased after AET. In addition, no robust correlation was identified between the changes of these miRNAs and makers of cardiac function and exercise capacity, which indicates a distinct adaptation of these miRNAs to exercise. Future studies are highly needed to define the potential use of these circulating miRNAs as useful biomarkers of exercise training, and disclose the biological function of circulating miRNAs as physiological mediators of exercise-induced cardiovascular adaptation.

Keywords: acute exercise; cardiopulmonary exercise testing; cardiovascular adaptation; circulating miRNAs; healthy adults.

FIGURE 1

Distinct regulatory profiles of selected circulating miRNAs before and after CPET. (A) Serum levels of cardiac or muscle-specific/enriched miRNAs before and after CPET. (B) Serum levels of angiogenesis-related miRNAs before and after CPET. (C) Serum levels of inflammation-related miRNAs before and after CPET. **P < 0.01; n = 8.

FIGURE 2

Distinct regulatory profiles of selected circulating miRNAs before and after AET. (A) Serum levels of cardiac or muscle-specific/enriched miRNAs before and after AET. (B) Serum levels of angiogenesis-related miRNAs before and after AET. (C) Serum levels of inflammation-related miRNAs before and after AET. *P < 0.05; n = 8.

FIGURE 3

Correlation analysis between the changes of miR-20a following CPET and cardiac function(EF%), exercise capacity (AT VO₂, peak VO₂, peak work load, METs) at baseline.

FIGURE 4

Correlation analysis between the changes of miR-21 following AET and cardiac function (EF%), exercise capacity (AT VO₂, peak VO₂, peak work load, METs) at baseline.