Abstract
Purpose: :
Pterygium is one of the most frequent pathology in ophthalmology, and is a bening, fibrovascular lesion, originated from the bulbar conjunctiva. It is composed of epithelium and highly vascular, subepithelial, loose connective tissue. The ethiology of pterygium is not clearly understood; the most widely recognized origin factor is ultraviolet radiation. It has been proposed that pterygium and neoplasia have common features raising the possibility that pterygium is a neoplastic-like growth disorder. The aim of this study was to investigate the differences in protein expression between pterygium and healthy conjunctiva.
Methods: :
Four pterygium specimens were obtained together with healthy conjunctival tissue from the same eyes. Total proteins of pterygium and conjunctiva were analyzed in SDS-PAGE. This analysis showed protein bands expressed exclusively in pterygium samples at the range of 20-25 kDa. After that, two-dimensional electrophoresis was performed for the separation of total proteins; differential spots expressed in pterygium were identified and selected, to be analyzed by electrospray and mass spectrometry in tandem (ES-MS/MS).
Results: :
These proteins were identified as peroxiredoxin 2, apolipoprotein AI and proapolipoprotein. RT-PCR showed that peroxiredoxin 2 and apolipoprotein AI were increased in pterygium compared to conjunctiva.
Conclusions: :
Peroxiredoxin-2 protects the cell against oxidative stress-induced apoptosis, and apolipoprotein AI has antiapoptotic effects and is related with carcinogenesis and progression. These results support that pterygium is a neoplastic-like growth disorder.
Keywords: pterygium • proteomics • apoptosis/cell death