Fig. 7.

Forskolin stimulation of sACI/II increases cytosolic cAMP and induces endothelial gap formation without reorganizing cortical actin cytoskeletal networks into stress fibers. PMVECs were treated with forskolin (10 μmol/l) or thrombin (10 U/ml) for 30 min. Similarly, PMVECs expressing sACI/II were treated with or without forskolin (10 μmol/l) for 30 min. Cells were subjected to phalloidin staining to assess actin stress fibers, as well as to Western blot analysis to evaluate MLC₂₀ phosphorylation. A: forskolin stimulation of sACI/II induces endothelial gap formation without disrupting cortical actin cytoskeletal networks and reorganizing them into stress fibers. Thrombin induces endothelial gap formation by disrupting cortical actin cytoskeletal networks and reorganizing them into stress fibers (positive control). Forskolin-treated PMVECs and control PMVECs expressing sACI/II neither form endothelial gaps nor reorganize cortical actin into stress fibers (negative controls, n = 3). The scale bars are equal to 25 μm. B: forskolin decreased MLC₂₀ phosphorylation in PMVECs expressing sACI/II (n = 3). Summary data are shown in C. *P < 0.05.