Abstract: OBJECTIVE To investigate the effect of Toll-like receptors (TLRs) signaling pathway on PM2.5-induced inflammation in mice aorta and the intervention of ferulic acid.METHODS Mice were treated with 10, 20 mg·kg^-1 PM2.5 respectively by onsurgical intratracheal instillation. Additionally, mice were concurrently treated with 40, 80 mg·kg^-1 ferulic acid at the high dose group (20 mg·kg^-1 PM2.5) for 2 weeks. The categories of inflammatory cells and inflammatory factors in serum were detected by hemathology analyzer. Isolated aortic tissue was isolated and the mRNA expression of IL-1β and IL-6 were determined by RT-PCR. The protein level of TLR2, TLR4, MyD88 and NF-κB p65 were detected by Western blot. The expression of TLR2 and TLR4 in mice aorta was also evaluated by immunohistochemistry.RESULTS The content and the ratio of NEUT and EOS were increased by PM2.5. The mRNA levels of IL-1β and IL-6 were overexpressed in both blood and aortic tissue. Meanwhile, TLRs signaling pathway-related protein such as TLR2, TLR4, MyD88, and NF-κB p65 were also increased in aortic tissue. After the intervention of ferulic acid, the numbers of NEUT, EOS, and the ratio of NEUT and EOS, as well as the level of inflammation factors including IL-6 and IL-1β were reduced. Moreover, the inhibition TLRs pathway in aortic tissue were also significantly reduced.CONCLUSION PM2.5 can induce the production of aortic inflammation in mice through TLRs signaling pathway. Moreover, ferulic acid can protect mice from PM2.5-induced aortic inflammation by inhibition TLRs pathway.