Boxb Mediate Balb/C Mice Corneal Inflammation Through A Tlr4/Myd88-Dependent Signaling Pathway In Aspergillus Fumigatus Keratitis

AIM: To investigate whether high-mobility group box 1 (HMGB1) Boxb exacerbates BALB/c mice corneal immune responses and inflammatory through the Toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88)-dependent signaling pathway in Aspergillus fumigatus (A. fumigatus) keratitis.METHODS: The mice corneas were pretreated with phosphate buffer saline (PBS), Boxb before A. fumigatus infection. The abdominal cavity extracted macrophages were pretreated with PBS, Boxb, TLR4 inhibitor (CLI-095), Dimethyl sulfoxide (DMSO) separately before A. fumigatus hyphae stimulation. HMGB1 was detected in normal and infected mice corneas and macrophages by real-time reverse transcriptase polymerase chain reaction (RT-PCR), the TLR4, MyD88, interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha) were detected by Western blot and PCR..RESULTS: In BALB/c mice corneas, the expressions of TLR4, HMGB1, IL-1 beta, TNF-alpha were increased after A. fumigatus infection. While pretreatment with Boxb significantly increased the expressions of TLR4, HMGB1, MyD88, IL-1 beta, TNF-alpha compared with PBS control after infection. In BALB/c mice abdominal cavity extracted macrophages, pretreatment with Boxb increased the expressions of TLR4, HMGB1, MyD88, IL-1 beta, TNF-alpha, while pretreatment with CLI-095 and Boxb significantly decreased the expressions of TLR4, HMGB1, MyD88, IL-1 beta, TNF-alpha.CONCLUSION: In A. fumigatus keratitis, Boxb play a pro-inflammatory role in corneal anti-fungi immune response through the HMGB1-TLR4-MyD88 signal pathway.