Corneal expression pattern of Semaphorin 3F

Abstract

Purpose : Semaphorins are known modulators of angiogenesis. In the retina, semaphorin 3F (Sema3F) is selectively expressed in the outer nuclear layer and retinal pigment epithelium. Retinal Sema3F expression thus co-localizes with the physiologically avascular zone in the outer retina. Previous work from our group and others have demonstrated an anti-angiogenic effect of Sema3F. We have thus investigated whether Sema3F expression might co-localize with other physiologically avascular ocular tissues such as the cornea.

Methods : Sema3F expression in murine and human corneas was analyzed using qPCR and immunohistochemistry. In addition, Sema3F expression was quantified in primary human corneal epithelial cells in vitro using qPCR and Western Blot.

Results : Quantitative PCR revealed Sema3F expression in both murine and human corneas. Corneal Sema3F expression was significantly higher compared to expression in the adjacent conjunctiva. Within the cornea, there was no difference in Sema3F expression between central and peripheral regions. Immunohistochemistry localized Sema3F protein in the cornea mainly to the epithelium. In concordance, isolated primary human corneal epithelial cells expressed Sema3F both on mRNA as well as protein levels.

Conclusions : Similar to the physiologically avascular outer retinal layers, Sema3F is strongly expressed in corneal epithelium. Importantly, Sema3F expression is high in the cornea and almost undetectable in adjacent conjunctiva, indicating a selective expression in physiologically avascular tissues. This was confirmed both on mRNA as well as protein levels. These data suggest a potential role for Sema3F in maintaining corneal tissue avascularity.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.