Abstract
Purpose: :
Pterygium is an ocular surface disease of unknown etiology characterized by growth of fibrovascular tissue from conjunctiva onto the cornea. The phospholipase(PL)-D is a class of enzymes involved in inflammation and differentiation. In cultured corneal epithelial cells, PLD plays a role in wound healing, and in other contexts they suppress apoptosis and increases cell motility. We aimed to investigate the presence of PLD subtypes in native ocular surface tissue and pterygium.
Methods: :
This study involved paired control or un-involved conjunctival and pterygium tissues. Reverse transcription semi-quantitative and quantitative PCR were performed to assess transcript levels for PLD1-5 in normal conjunctiva and pterygium tissue. Immunofluorescent staining using antibodies against PLD1/2 was used to investigate expression and tissue distribution. Western blots were performed for protein detection and to confirm the specificity of the antibodies used.
Results: :
Phospholipases-D1,2,3 and 4 transcripts were detected in normal conjunctiva tissue, and types 2,3 and 4 were up-regulated in pterygium. Immunofluorescent staining showed the presence of phospholipase-D1/2 in normal cornea, conjunctival and pterygial epithelia. In normal cornea and conjunctival epithelia, the expression was mainly localized to the nuclei of the basal and suprabasal epithelial cells, whereas in pterygium, this expression was limited to the cytoplasm and peri-plasma membrane regions. Western blot confirmed the presence of PLD1/2 in proteins extracted from pterygium and conjunctiva tissue.
Conclusions: :
Phospholipase-D subtypes are present in human ocular surface epithelium. We hypothesize that phospholipase-D may be involved in pterygium pathogenesis.
Keywords: pterygium • microscopy: light/fluorescence/immunohistochemistry • conjunctiva