PPARγ: the dominant regulator among PPARs in dry eye lacrimal gland and diabetic lacrimal gland

AIM: To determine whether lectin-like ox-LDL receptor (LOX-1) regulates adhesion molecules expression and neutrophil infiltration in A. fumigatus keratitis of C57BL/6 mice.METHODS: C57BL/6 mice were pretreated with a neutralizing antibody to LOX-1 (5 μg/5 μL) or control nonspecific IgG (5 μg/5 μL), LOX-1 inhibitor Poly-I (2 μg/5 μL) or PBS by subconjunctival injection. Fungal keratitis mouse models of C57BL/6 mice were established by scraping corneal central epithelium, smearing A. fumigatus on the corneal surface and covering the eye with contact lenses. The corneal response to infection was assessed via clinical score. The mRNA levels of the adhesion molecules ICAM-1, VCAM-1, P-selectin and E-selectin were tested in control and infected corneas by RT-PCR. The protein levels of ICAM-1 were evaluated by immunofluorescence (IF) and Western blot. Neutrophils were extracted from the abdominal cavity of C57BL/6 mice followed by pretreatment using antibody to LOX-1 (10 μg/mL) or control nonspecific IgG (10 μg/mL), the Poly-I (4 μg/mL) or PBS. The cells were then stimulated with A. fumigatus and tested mRNA and protein levels of LFA-1 using RT-PCR and Western blot. IF and myeloperoxidase (MPO) assays were used to assess neutrophil infiltration in mice corneas.RESULTS: Pretreatment of LOX-1 antibody or the Poly-I reduced the degree of inflammation of cornea and decreased the clinical fungal keratitis score compared with pretreatment of IgG or PBS. And these pretreatment also displayed an obvious decline in the mRNA levels of ICAM-1, VCAM-1, P-selectin, E-selectin and LFA-1 expression compared with control groups . Furthermore, pretreated with LOX-1 antibody or Poly-I, the protein levels of ICAM-1 and LFA-1 also decreased compared with control groups. Neutrophil infiltration in the cornea was significantly reduced after pretreatment of LOX-1 antibody or Poly-I compared with control groups by IF and MPO assays. CONCLUSION: These data provide evidence that inhibition of LOX-1 can decrease the expression of adhesion molecules and thus reduce neutrophil infiltration in A. fumigatus infected corneas of C57BL/6 mice.

[Online First]Regulation of LOX-1 on adhesion molecules and neutrophil infiltration in mouse Aspergillus fumigatus keratitis