0 10 20 30 40 50 0 50 100 150 Treatments Time (hrs) % Resistance Normal / Untreated VEGF IL-6/R VEGF + IL-6/R ↑ Treatment IL-6 and VEGF each disrupt the blood-retinal barrier independently. When combined, they cause an even greater loss of barrier integrity • Ocular inflammation damages tight junctions between endothelial cells, compromising the integrity of the blood retina barrier. This increases vascular permeability • The integrity of the blood-retinal barrier can be measured by barrier resistance • Exposure to both IL-6/R and VEGF additively induces greater loss in barrier function , as measured by decreased barrier resistance, than either IL-6 of VEGF alone, in human umbilical vein endothelial cells (HUVEC) Combination of IL-6/R + VEGF induces greater loss of barrier resistance and function than either VEGF or IL-6 alone Exposure start No exposure HUVEC cells were treated as indicated after growth to establish barrier High barrier resistance from intact tight junctions Assessing vascular endothelial barrier integrity using electrical resistance measurements 49