Boxb mediate BALB/c mice corneal inflammation through a TLR4/MyD88-dependent signaling pathway in Aspergillus fumigatus keratitis.

Abstract

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. 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-1β (IL-1β), tumor necrosis factor-α (TNF-α) were detected by Western blot and PCR. In BALB/c mice corneas, the expressions of TLR4, HMGB1, IL-1β, TNF-α were increased after A. fumigatus infection. While pretreatment with Boxb significantly increased the expressions of TLR4, HMGB1, MyD88, IL-1β, TNF-α 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-1β, TNF-α, while pretreatment with CLI-095 and Boxb significantly decreased the expressions of TLR4, HMGB1, MyD88, IL-1β, TNF-α. In A. fumigatus keratitis, Boxb play a pro-inflammatory role in corneal anti-fungi immune response through the HMGB1-TLR4-MyD88 signal pathway.