Monoclonal antibodies directed to VE-cadherin prevent the protective effect of VEGF on endothelial cell apoptosis.

Endothelial cells were maintained without serum in the absence or presence of mAbs for 48 hours; 63% ± 7% control cells underwent apoptosis, and this percentage was not significantly modified by addition of the mAbs (not shown). When VEGF (30 ng/mL) was included in the absence of mAbs, apoptotic endothelial cells decreased to 31% ± 2%. Addition of the mAbs together with VEGF increased the apoptotic index. The values in the figure are expressed as percentage increase in apoptosis in comparison to cells cultured in absence of the mAbs and in the presence of VEGF. Data are means ± SEM of 4 replicates from a typical experiment out of 4 performed.