Change in gene expression of toll-like receptor pathways in response to preseason conditioning in elite NCAA Division 1 wrestlers

Abstract

This study examined the effects of both a single bout of intense exercise and 1 month of intense preseason conditioning on the expression of Toll-like receptor (TLR) proteins and signaling pathways. Eight elite Division I wrestlers were followed through the preseason training period. Blood samples were collected before preseason training started (at rest), after two weeks of training (within 30-60 minutes after completing a ~1.5 hour exhaustive exercise session) and following the pre-season training period (at rest). After the collection of blood samples from the athletes, peripheral blood mono-nuclear cells (PBMC) were separated from the whole blood samples. Messenger RNA was isolated from the PBMC’s and TLR focused gene expression was measured using DNA microarray. Illness records were collected over the wresting season. The microarray results demonstrated a significant change (p<.05) in gene expression for seven genes following the single bout of intense exercise (decrease in IFNγ, IRF-1, IL-6 and an increase in PGLYRP2, LY86, TIRAP, TLR5), and a decrease in seven genes following the one month training period (PRKRA, SARM1, IFNα, TLR3, PTGS2, TNFSRF1, REL). The decrease in IFNγ in response to one bout of exhaustive exercise was significantly correlated with the number of events with cold symptoms lasting longer than 1 week (p=0.02). Similarly, the decrease in REL and PTGS2 expression after preseason training were correlated with increased in the total number of days with illness symptoms. The findings from this study have demonstrated that changes in TLR gene expression do occur in response to intense exercise training, and that these changes may be correlated with subsequent infection.