Figure 8

Tubulogenesis is impaired in uPAR^-/- ECs: Bead-based fibrin gel angiogenesis was observed at 96 hr and the cells were stained for actin using phalloidin-TRITC (red) and DNA (blue) and imaged using a 20× objective. Formation of capillary-like structures at 96 hr in WT cells in control (A) assay and in the presence of 10 ng/ml VEGF was observed (C). In beads plated with uPAR^-/- ECs, highly branched sprouts were observed but were not organized to form capillary-like structures in the absence or presence of VEGF (B, D).