Modification of Gene Expression and Protein Profiles by Exhaustive Exercise in Pathogen- stimulated and Un-stimulated Peripheral Blood Cells

Abstract

It is well know that in contrast to moderate physical activity, an acute bout of prolonged, exhaustive exercise such as marathon or half-marathon running can cause adverse effects on immunity as reflected by transient immunosuppression following the event. We used microarray technology as well as other approaches to study the response of selected and non-selected immune-related genes and proteins following an exercise program. The capacity of whole blood cultures to produce cytokines in response to endotoxin (LPS) was studied (Paper I). Further, the early steps of the immune reaction to pathogen contact were evaluated in details using whole blood culture and gene expression profiling approach in athletes before, 30 min after, 3 h after and 24 h after a half-marathon run (Paper II). Gender and menstrual phase dependent differences in cytokine and gene expression profiles of 12 male subjects (M) and 9 women with regular menstrual cycles was also studied in response to an aerobic exercise at 93% of the individual anaerobic threshold (Paper VI), and the effect of exercise on the miRNA response of eight highly trained athletes before and after moderate exercise was investigated using microarray technology (papers IV). A strong and significant reduction in LPS-dependent release (LDR) of TNF-α and slight reduction in LDR of IL-6 was observed in both male and female athletes following exhaustive exercise. There was a significant enhancement in the concentration and gene expression of IL-10 at 30min post exercise in both sexes. IL-10 was higher in men than in women and not influenced by LPS (Paper I). The results of the microarray study showed that expression of several genes with prominent anti-inflammatory function was strongly up-regulated by exhaustive exercise in both stimulated and un-stimulated cultures, but some genes such as TNIP3 (a prominent inhibitor of the LPS/TLR signaling cascade ) were strongly up-regulated in LPS-stimulated cultures only (Paper II). The study of the miRNA response revealed four dynamically regulated miRNA- RNA networks following exercise. miRNAs- 24-2-5p, 27a-5p, and 181a-5p were up-regulated immediately after exercise, but tended to down-regulate at recovery. miRNA-21-5p demonstrated different expression profiles over time (Paper IV). Results of gender studies showed that women in luteal phase exhibit different responses of gene regulation as compared to women in follicular phase and men. Several pro-inflammatory genes including PTGDR, IL-18RAP and IL-12B1 were significantly up-regulated in women in luteal phase of their menstruation, while these genes were down-regulated in the follicular phase of the same women and in men. Conversely, women in luteal phase showed a strong trend towards down-regulation of anti-inflammatory genes (e.g. IL-6, IL-1ra). For conclusion, the results of our studies demonstrate that exercise has a distinct impact on the early cytokine response to pathogen and this response has a dramatic anti-inflammatory bias. In addition, Microarray analysis could reveal a set of exercise reactive genes which can only be detected in presence of pathogen stimulation (e.g. TNIP3 and IFNβ1). Moreover, it is clear, from these results, that women in luteal phase of their menstrual cycle show significantly less anti-inflammatory regulation than women in follicular phase or men. And finally, microRNAs are involved in exercise induced gene expression changes and dynamically regulated miRNA/mRNA networks could be demonstrated.