Purchase this article with an account.
JI Patel, DJ Wateridge, ZJ Gregor, PG Hykin, P Adamson, J Greenwood; Caveolae and Intercellular Junctions of Retinal Endothelial Cells are Modulated by Clinically Relevant Concentrations of VEGF . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1315.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose:We have previously shown at ARVO (2001) that 2 groups of patients with persistent clinically significant diabetic macular edema (CSME) with moderate NPDR may exist based on differential OCT macular profiles and vitreal VEGF levels: Group 1(dome shaped profile; mean VEGF 0.7ng/ml) and Group 2 (diffuse-low elevation profile; mean VEGF 1.7ng/ml). The purpose of the present study was to characterize the effect of these levels of VEGF in comparison to previously used concentrations of VEGF (100 ng/ml) on the permeability pathways in cultured retinal endothelial cells. Methods:Confluent rat retinal endothelial cell monolayers were treated with VEGF (ng/ml) at 100, 1.7, and 0.7 for 30 minutes and 24 hours in complete medium or subsequent to serum starvation for 2 days. The distribution of junctional proteins zonula occludens 1 (ZO-1) and beta-catenin as well as caveolin-1 were assessed by immunocytochemistry. Trans-endothelial electrical resistance (TER) measurements and immunoblotting were also performed. Results:100ng/ml VEGF induced disorganized staining of ZO-1 whilst the lower concentrations of VEGF caused no change in ZO-1 junctional distribution. There were no changes in beta-catenin distribution under any of the conditions. At 100ng/ml VEGF, there was marked redistribution of caveolin-1 away form the cell border to a perinuclear distribution. At the lower concentrations of VEGF both cell border and perinuclear caveolin-1 were observed. All VEGF treatments showed a 50% decrease in TER. Antiphosphotyrosine blotting showed concentration dependent differences between VEGF treatments. Conclusion:At concentrations of VEGF recorded in the vitreous of patients with diabetic CSME, junctional component distribution appears unaffected although functional integrity of the barrier is reduced as shown by a decrease in the TER. This data suggests VEGF can modulate paracellular permeability and transcellular pathways (as represented by caveolin-1 as a marker for caveolae) at concentrations found in patients with macular edema.
This PDF is available to Subscribers Only