Immunolocalization of transcription factor AP1 in human ocular surface epithelia

Purpose. The present study examined whether normal human ocular surface epi thelia express AP1 components. Changes in expression patterns of these comp onents in a case of ocular surface epithelial dysplasia was also evaluated before and after topical mitomycin C treatment. Methods. Specimens of normal corneas (n = 2) and conjunctiva (n = 4) were o btained from 4 patients during cataract surgery or post mortem, while speci mens of dysplastic epithelial tissue from the limbus were obtained from one patient. Specimens were immunohistochemically studied using antibodies aga inst components of AP1. Results. The normal corneal epithelium showed no staining with antibodies a gainst c-Fos, Fra-2, FosB, c-Jun or JunB, whereas the limbal and bulbar con junctival epithelia were positive for c-Fos, Fra-2, and c-Jun. Anti-FosB an d -JunB antibodies reacted weakly with the conjunctival epithelium. JunD wa s absent in normal corneal and conjunctival epithelia. The dsyplastic epith elium showed positive labelling for c-Fos, Fra-2, c-Jun, and JunD throughou t its thickness. Fra-1 was present in all specimens of epithelia examined. The dysplastic epithelium treated with mitomycin C was not labeled by anti- c-Fos or -Fra-2 antibody. Conclusion. Individual AP1 components show specific expression patterns in normal ocular surface epithelia and a case of dysplastic epithelium before and after topical MMC treatment, implying that these factors may play impor tant roles in modulating epithelial cell function, e.g., proliferation and differentiation.