Abstract
Purpose: :
Pterygium is an ocular surface disease of unknown etiology. The aim of this study is to investigate the effect of UV irradiation, wounding or inflammation on the expression of pterygium-associated genes in normal conjunctival fibroblasts from five pterygium patients.
Methods: :
Un-involved conjunctival tissues from five patients who underwent pterygium excision were examined. UV irradiation was performed at 20mJ/cm2. Multiple scrape wounds of monolayer cultures were performed in a cross-hatched pattern with multiple strokes of a multi-channel pipette fitted with five pipette tips. TNF-α was added to the cells at 20ng/ml. Cells were analysed 24 h after treatment. Real-time quantitative PCR (qPCR) was used to examine the expression of collagen I, fibronectin, α-SMA, MMPs, IL-8 and MCP-1. Scratch wound assay in the presence of mitomycin-C was used to determine the migration rate while the xCelligence system was used to study cell growth rate.
Results: :
qPCR showed that none of the treatments caused changes in ECM or α-SMA mRNA expressions. UV irradiation alone had no effects on the mRNA expression of any of the genes examined. Wounding induced MMP-1 and -3 mRNA expressions of three patients. TNF-α treatment induced greater MMP-1, -2, -3, -14 and MCP-1 mRNA expressions in the other two patients. These latter two patients also have conjunctival cells that migrated and proliferated at a faster rate than the former group of three patients.
Conclusions: :
Our data suggests that there are potentially two groups of patients with unique conjunctival fibroblast properties that increase their risks of developing pterygium. One group is more susceptible to wounding whilst a second group is more vulnerable to inflammation with fibroblasts displaying faster migration and proliferation rates.
Keywords: pterygium • inflammation • gene/expression