Epithelial Membrane Protein 2 Expression in Human Proliferative Vitreoretinopathy Membranes

Abstract

Purpose: : Epithelial Membrane Protein 2 (EMP2) is found in a number of different cell types controlling cell surface expression and function of specific integrin isoforms. In retinal pigmented epithelium, expressions of some of these integrins have been found to be involved with retinal disease. Previous research in vitro has found EMP2 expression can regulate RPE migration. In animal models of proliferative vitreoretinopathy (PVR), blocking EMP2 expression leads a reduction of PVR pre-retinal membranes. We wanted to examine the expression of EMP2 in human proliferative vitreoretinopathy resulting from retinal detachment and in membranes found in other retinal conditions (e.g. proliferative diabetic retinopathy).

Methods: : Proliferative vitreoretinopathy (PVR) membranes were collected from patients with consent. The PVR membranes were fixed and processed for paraffin embedding. The protein expression of EMP2 was then evaluated in the tissue sections by immunohistochemical analysis.

Results: : Expression of EMP2 is present in human PVR membranes from various causes. Qualitative analysis shows varied expression amongst tissue samples, and EMP2 expression appears to correlate with PVR activity.

Conclusions: : EMP2 is expressed in the pre-retinal membranes found in human PVR. This further supports its potential role in the development of human PVR, and may prove to be a therapeutic target. Discovering how the expression varies in different types of retinal disease will help us to further delineate its role. Quantitative analysis is also currently underway for EMP2 expression.

Keywords: proliferative vitreoretinopathy • immunohistochemistry • retinal pigment epithelium