The Effect of Aerobic Exercise after Carbon Black Exposure on TLR4 and TLR2 Gene Expression in Hippocampus Tissue of Wistar Rats

Exposure to air pollution affects central nervous system and leads to neuroinflammation and neurodegeneration. The aim of this study was to evaluate the effect of aerobic exercise and carbon black exposure on TLR4 and TLR2 mRNA gene expression in the hippocampus of rats. 24 male Wistar rats were randomly assigned to 4 groups: A: control, B: exposure to pollution, C: exercise, D: exercise-pollution. B and D groups were exposed to PM10 carbon black for 4 weeks. The D and C groups carried out aerobic exercise program with 50% of their own maximal speed (60 minutes per session) after each session of pollution. The mRNA gene expression of TLR4 and TLR2 were analyzed in hippocampus tissue of rats by Real time – PCR. In order to determine the significance of the effect of exercise and pollution, two-way ANOVA test was used. Carbon black air pollution significantly increased TLR4 (P=0.005) and TLR2 (P=0.033) mRNA gene expression. The exercise had no significant effect on the mRNA gene expression of TLR4 (P=0.137) and TLR2 (P=0.113). The exercise following an exposure to polluted air had no significant effect on mRNA gene expression of TLR4 (P=0.063) and TLR2 (P=0.867) in hippocampus tissue of male rats. Also, the exercise was associated with a significant decrease in body mass in carbon black exposed groups. It seems that aerobic exercise reduces TLR4 and TLR2 in hippocampus tissue of rats after an exposure to polluted air and may be able to moderate the neuroinflammatory effects resulted from pollution.