Abstract
Purpose: :
Chronic exposure to ultraviolet (UV) light is a widely accepted aetiological factor in the development of pterygium. UV radiation may induce production of reactive oxygen species via photosensitized oxidation, thus causing oxidative damage.
Methods: :
A PCR array was used to detect possible changes in oxidative stress related genes in pterygium. The research reported was conducted in compliance with "Declaration of Helsinki". The mRNA levels for 84 genes were analysed in pterygium and normal conjunctiva. Total RNA was isolated from pterygium and conjunctiva and the quantity and quality of the RNA extracts were determined by measuring the absorbance at 260 nm and 280 nm. Each RNA sample (0.5 µg) was prepared according to the manufacturer’s instructions and Real-time PCR was performed. Gene expression was compared according to the CT value. The normalizer used for each cDNA sample was the average of five housekeeping genes.
Results: :
Analysis of 84 oxidative stress related genes showed that five genes of them significantly and differentially regulated, namely, Epoxide hydrolase 2 (EPHX2), Aldehyde oxidase 1(AOX1), Dual specificity protein phosphatase 1 (DUSP1), Neutrophil cytosolic factor 2 (NCF2), and Selenoprotein S (SELS S). The genes that were significantly different (P < 0.05) between pterygium and normal conjunctiva varied by >4-fold. Of the 84 evaluated genes, one was upregulated (EPHX2) and four were downregulated. The greatest induction occurred in EPHX2 (almost 700-fold), whereas the greatest suppression was noted in DUSP1 (–11-fold).
Conclusions: :
The oxidative gene expression in the pterygium tissues indicate that oxidative stress could play a role in the development of pterygium. These findings provide new information to better understand the pathogenesis of pterygium and may be useful for further research in the prevention and treatment of this disease.
Keywords: pterygium • oxidation/oxidative or free radical damage • gene/expression