Abstract
Purpose :
Little is known about Fibulin-3 (FBLN-3) expression in the human retina. A point mutation in the EFEMP1 gene (encoding FBLN-3) is known to be associated with Doyne honeycomb retinal dystrophy, an inherited macular degeneration associated with drusen formation at a young age. However, the role of FBLN-3 in drusen formation and disease pathogenesis remains unclear. The purpose of this study was to determine the expression pattern of FBLN-3 in sections of healthy and diseased human retina.
Methods :
Fresh frozen and paraffin-embedded sections of human eyes were procured from NDRI. Donors had either no history of eye disease or were known to have age-related macular dystrophy. Sections were probed with primary antibody to FBLN-3, and labelled for confocal microscopy imaging (Leica SP8). Sections were also labelled for the drusen marker, ApoE.
Results :
Confocal microscopy revealed dense FBLN-3 immunoreactivity in the retinal pigment epithelial cells (RPE) in both healthy and diseased retinas. Immunoreactivity for ApoE identified numerous drusen beneath the RPE cells. Punctate FBLN-3 immunoreactivity was located within drusen in some places but generally did not colocalize with ApoE.
Conclusions :
FBLN-3 is expressed abundantly within the human RPE and does not appear to be expressed in other parts of the eye. ApoE was a good marker for drusen in this study and FBLN-3 appeared within small vesicle-like structures within the drusen. The abundance of FBLN-3 within RPE suggests that it has an important function there and may accumulate to some degree in drusen.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.