Effect Of Exercise On Gene Expression In Peripheral Blood Mononuclear Cells (PBMCs) In Girls

Abstract

Brief exercise results in substantial changes in gene expression of circulating PBMCs. Moreover, many key gene pathways influenced by exercise are related to inflammation. We hypothesized that microRNAs (small 21–23 nucleotide non‐coding RNAs) would also be changed by exercise and act to prevent a predominantly pro‐inflammatory PBMC response that could be dangerous. 12 healthy men (19–30 y.o.) performed 20 min of cycle ergometry (~75% peak VO2). PBMCs were isolated before and after the exercise. Using the Agilent Human miRNA Microarray (V2), we found that exercise altered 94 miRNAs (FDR=0.2; 61 downregulated). Many of the miRNAs altered by exercise are known to play mechanistic roles in other inflammatory processes [e.g., miR‐125b(↓) and miR‐146a(↓) which are downregulated by proinflammatory factors LPS and TNF‐α, respectively). We also found exercise effects on miRNAs associated with B‐cell development, e.g., miR‐181a(↑), ‐150(↓), and ‐17(↓). Further, we compared the miRNA changes in PBMCs with the 38 miRNAs in neutrophils that we previously found to have been altered by exercise. 18 miRNAs were affected in both PBMCs and neutrophils, but only 12 changed in the same direction. In conclusion, brief heavy exercise changes miRNA profiles in PBMCs many of which are related to inflammatory processes. The pattern of change suggests that exercise differentially influences miRNAs in leukocyte subtypes. Grants: Supported by NIH grants P01‐HD048721 and RO1‐HL080947