epiglucan and Corneal-Ulcer

To investigate the expression and function of the mannose receptor (MR) and to explore its interaction with dectin-1 in human corneal epithelial cells (HCECs) exposed to Aspergillus fumigatus.. HCECs were stimulated with A. fumigatus for 0, 4, 8, 12, 16, and 24 hours. MR expression was tested by the polymerase chain reaction, Western blot, and immunohistochemistry. HCECs were pretreated with 2 μg/mL MR-blocking antibody. The expressions of p38, phosphorylated p38 (p-p38), and the downstream cytokines (TNF-α and IL-1β) and dectin-1 were tested by the polymerase chain reaction, Western blot, and enzyme-linked immunosorbent assay. HCECs were pretreated with dectin-1 agonists (curdlan, 100 μg/mL) and inhibitors (laminarin, 10 μg/mL), and the expression of the MR was tested.. MR expression was upregulated after stimulation with A. fumigatus. MR mRNA and protein levels began to rise at 8 and 16 hours, respectively. Stronger immunostaining of the MR was observed in fungal-infected corneal epithelium than in normal corneal epithelium. Aspergillus fumigatus increased the production of TNF-α (11-fold, 4-fold of the control), IL-1β (4.7-fold, 3-fold of the control), p-p38 (2.1-fold of the control), and dectin-1 (2.3-fold, 2-fold of the control) in mRNA and protein levels. The MR antibody significantly suppressed the expression of TNF-α (28%, 50% reduction), IL-1β (38%, 42% reduction), p-p38 (38% reduction), and dectin-1 (48%, 47% reduction). Curdlan increased the production of the MR (1.5-fold, 1.9-fold of the control), whereas laminarin decreased the expression of the MR (50%, 60% reduction) induced by A. fumigatus.. HCECs express the MR, and A. fumigatus infection can increase MR expression. A. fumigatus induces the expression of inflammatory cytokines through the MR and p38 MAPK pathway. The expression of dectin-1 and the MR had mutual influence.

Topics: Aspergillosis; Aspergillus fumigatus; beta-Glucans; Blotting, Western; Corneal Ulcer; Cytokines; Drug Interactions; Enzyme-Linked Immunosorbent Assay; Epithelium, Corneal; Eye Infections, Fungal; Humans; Lectins, C-Type; Mannose Receptor; Mannose-Binding Lectins; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Polysaccharides; Real-Time Polymerase Chain Reaction; Receptors, Cell Surface; Tissue Donors; Up-Regulation

Increased concentration of (1,3)-beta-D-glucan, one of the major components of fungal cell walls, is detected in the serum of systemic fungal infection. In our study, the concentration of (1,3)-beta-D-glucan was measured in the tear fluid of patients with mycotic keratitis.. Tear fluid was collected from patients with fungal keratitis (n = 4) and bacterial corneal ulcers (n = 4) with or without corneal scraping. In addition, tear fluid was collected from patients without corneal diseases.. The concentration of (1,3)-beta-D-glucan in tear fluid collected without corneal scraping was 4.0 +/- 3.5, 5.8 +/- 2.6, 184 +/- 128 pg/ml in the control, bacterial corneal ulcer, and mycotic keratitis samples respectively. The concentration of (1,3)-beta-D-glucan in tear fluid collected after scraping the corneal lesions with a tip of glass capillary was 4.4 +/- 1.3, 8.2 +/- 5.2 and >1,000 pg/ml in the control, bacterial ulcer, and mycotic keratitis samples respectively.. A significant increase in (1,3)-beta-D-glucan was detected in tear samples from patients with mycotic keratitis. Measuring the concentration of (1,3)-beta-D-glucan in tear fluid might be helpful in the diagnosis of mycotic keratitis.

Topics: beta-Glucans; Corneal Ulcer; Eye Infections, Bacterial; Eye Infections, Fungal; Humans; Keratitis; Osmolar Concentration; Proteoglycans; Tears