The Role of LOX-1 in Innate Immunity to Aspergillus fumigatus in Corneal Epithelial Cells.

Abstract

To determine the role of lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) in corneal epithelial cells exposed to fungus. Thirteen corneas with fungal keratitis composed the experimental group. Ten healthy donor corneas were the control group. Corneal epithelium was scraped and LOX-1 mRNA tested. Immunostaining was used to detect LOX-1 protein. Human corneal epithelial cells (HCECs) were treated with 75% ethanol-killed Aspergillus fumigatus. LOX-1 was detected, and CXCL1, TNF-α, IL-6, and dectin-1 levels were detected with or without neutralization of LOX-1. Rat fungal keratitis was established and LOX-1 was detected by PCR, immunostaining, and Western blot. Phosphorylated-p38MAPK (p-p38MAPK) protein; CXCL1, TNF-α, and IL-6 mRNA levels; and myeloperoxidase (MPO) were tested before and after LOX-1 neutralization. LOX-1 was expressed in corneal epithelium. In vitro cellular experiment showed that LOX-1 was detected in normal HCECs, and LOX-1 mRNA increased after stimulation of A. fumigatus and peaked at 8 hours; LOX-1 protein expression increased after stimulation at 24 and 48 hours. Neutralization of LOX-1 decreased expression of CXCL1, TNF-α, but did not change IL-6 or dectin-1 expression. Aspergillus fumigatus keratitis developed in rats activated p38MAPK and elevated the expression of CXCL1, TNF-α, and IL-6 through LOX-1. LOX-1 neutralization reduced MPO levels. LOX-1 expressed in normal corneal epithelium and HCECs and A. fumigatus elevated the expression of CXCL1 and TNF-α through LOX-1. Rat A. fumigatus keratitis activated p38MAPK and elevated the expression of CXCL1, TNF-α, and IL-6 through LOX-1.