Figure 6. Effect of senescence on antigen expression and migration of late outgrowth endothelial cells (OECs) and Human Umbilical Vein Endothelial Cells (HUVEC). A: Expression of different antigens by control nonsenescent OECs, OECs treated with SU5416 (6 μM) for 7 days and late-passage naturally senescent OECs was detected by flow cytometry. The graphs represent the mean±Standard error of the mean (SEM) percentage of positive cells for OECs derived from three different patients. * indicates a statistically significant difference (p<0.05) as compared to control OECs. B: Migration of control OECs, OECs treated with SU5416 (6 μM) for 7 days and late-passage naturally senescent OECs to Vascular Endothelial Growth Factor (VEGF), Stromal Cell derived Factor-1 (SDF-1) and complete angiogenic medium (EGM-2MV) is shown. The graphs represent the mean±SEM percentage of migrated cells (as compared to cells migrated to EBM-2 basal medium without the addition of serum or growth factors) for OECs derived from three different patients. * indicates a statistically significant difference (p<0.05) as compared to control OECs.