Decreased Expression of Cytosolic Phospholipase A2 in Normal Conjunctiva May be Contributing to the Formation of Pterygium

Abstract

Aim: Although there has been ongoing evidence about the role of inflammation in the pathophysiology of pterygium, exact inflammatory pathogenesis is not known. Cytosolic phospholipase A2 (cPLA2) is an inflammatory enzyme taking a role in various physiological and pathological responses. The present study aimed to investigate the expression of cPLA2 in human pterygium tissues. Materials and Methods: Expressions of cPLA2 were analyzed by immunohistochemistry in biopsy specimens of 20 pterygium and 10 normal conjunctival tissues. Expression patterns and staining intensities were compared between pterygium and normal tissues. Results: Intense expression of cPLA2 was present in all normal conjunctival tissues (100%) whereas no expression was detected in 5 pterygium cases (25%), and in the remaining pterygium tissues (75%) mild/ moderate expression of cPLA2 was shown. Furthermore, expression was shown throughout the epithelium being more intense in the superficial layers in normal conjunctivas, whereas it was mainly located in basal layers in pterygium tissues. Conclusion: Downregulated expression of cPLA2 in pterygium tissues compared to normal conjunctiva shown in the present study supports the role of inflammatory enzymes in the formation of pterygium. cPLA2 enzyme seems to have a protective role against pterygium formation.