C-MAF Expression in Adult Human Ocular Surface and its Implication in Pterygium Pathogenesis

c-MAF, a transcription factor that belongs to the b-Zip Maf transcription factor family, was found to be critical for lens development in vertebrates. It is a well-known fact that the adult human ocular surface expresses c-MAF, however, its role in the limbus, cornea and conjunctiva remains unknown. Thus, the present study aimed to investigate c-MAF expression within the human ocular surface, and its potential role in pterygium pathogenesis. Methods: We performed immunohistochemical staining to detect c-MAF expression in frozen adult human tissue sections, including the limbus, cornea and conjunctiva, and cultured cells from eye cadavers. We then compared c-MAF expression to the expression of a known protein, P63. Lastly, we performed RT-PCR, and immunohistochemistry for c-MAF expression in healthy adult human conjunctiva and pterygium. Results: We found differential c-MAF expression between adult human limbus, cornea and conjunctiva tissues. Further, we observed that c-MAF is downregulated in the pterygium compared to healthy conjunctiva. Conclusions: Overall, our results suggest that c-MAF may play a context-specific role in maintaining limbal, corneal and conjunctival homeostasis, and may be critical for preventing pterygium development in humans.