VEGF analogs induce P-selectin cell surface expression in HUVECs. P-selectin translocation was quantified by cell surface ELISA. DPBS was used as negative control and the basal levels of cell surface P-selectin were normalized to 1. The translocation of P-selectin induced by VEGF-A165 (10–9 M) was determined as a function of the time (0-15 minutes; A) and at various concentrations (10–12-10–8 M) in cells treated for 7.5 minutes (B). Translocation of P-selectin induced by VEGF analogs was assessed at various concentrations (10–12-10–8 M) in cells treated for 7.5 minutes (C-G). The combination of VEGFR-1 and VEGFR-2 agonists (10–9 M; 7.5 minutes) on P-selectin translocation was assessed (H). In each experiment, a group of cells was treated with normal rabbit IgG to evaluate the nonspecific binding, which was subtracted from the values obtained on stimulation with agonists. Data are means ± SEM of at least 12 experiments; ***P ≤ .001 as compared to DPBS.
