Fig. 5. Rescue of PMA-mediated disintegration of surface endothelial cells co-cultured with smooth-muscle cells in three-dimensional spheroids. Co-culture spheroids of HUVECs and HUASMCs were incubated in spinner culture with the indicated combinations of reagents for 4 hours and endothelial-cell detachment was quantified by automated image analysis of CD31 whole-mount-stained spheroids. PMA treatment leads to massive denudation of the surface endothelial-cell monolayer within 4 hours (A,C). Both Ang-1 (A,E) and VEGF (A,F) inhibit the PMA-mediated destabilization of the endothelial-cell monolayer. In turn, sTie-2 cannot block PMA-mediated perturbation of endothelial-cell-monolayer integrity (A,D). ^**, P<0.001 compared with control; #, P<0.001 compared with PMA treatment.