Figure 6. Time courses for collagen IV proteolysis and colocalization of collagen IV degradation products with cav-1 during HUVEC tube formation.
HUVEC were grown on glass coverslips coated with rBM containing 25 μg/ml DQ-collagen IV. (A) Confocal images were taken of live cells between 2 and 16 h. DQ-collagen IV degradation products (green) are seen surrounding tubular structures and at the rear of a migrating endothelial cell (arrow). Cell sprouting is observed at 2h (arrowheads). Bar, 100 μm. (B) Confocal images were taken between 1 and 4 h of live HUVEC transfected with cav-1-mRFP. DQ-collagen IV degradation products (green) and cav-1 (red) are seen colocalized (yellow) intracellularly (arrowheads) and pericellular degradation of DQ-collagen IV is observed at the rear of a migrating endothelial cell (arrows). Black arrows represent the original location of a migrating HUVEC cell (in box) at 1h. Bar, 20 μm.