Abstract
Purpose: :
Fibulin-3 (EFEMP1) is an extracellular glycoprotein contributing to the infrastructure of basement membranes throughout the body. While the role of fibulin-3 is not clearly understood, it is hypothesized to regulate cell growth and to inhibit angiogenesis. Fibulin-3 missense mutations cause Familial Dominant Drusen, a macular degenerative disease with a presentation similar to that of age-related macular degeneration. Fibulin-3 expression has been shown in retinal pigment epithelium (RPE) and Bruch’s membrane, but other ocular sites of fibulin-3 expression in healthy eyes are poorly understood. We wanted to evaluate fibulin-3 expression, using a newly generated antibody to the human protein.
Methods: :
A polyclonal rabbit antibody was generated from a peptide unique to human fibulin-3. Human autopsy eyes without preexisting eye disease were used. We performed fluorescent immunohistochemical analysis via confocal microscopy. Additional controls included rhesus monkey retinae and optic nerve sections, as well as antibody + free peptide. All tissues were obtained under appropriate previously approved IACUC and IRB protocols.
Results: :
Variable fibulin-3 immunoreactivity occurred in the corneal epithelium and Descemet's membrane. There was also apparent expression in ciliary body. Minimal fibulin-3 expression was apparent in normal human optic nerves.
Conclusions: :
In addition to posterior pole structures, fibulin-3 expression may occur in a variety of normal human ocular tissues. The current antibody to fibulin-3 may prove useful in evaluation both of posterior eye pathology, as well as examining disease- or age-related changes in the anterior segment.
Keywords: Bruch's membrane • choroid • cornea: basic science