Vascular Endothelial Growth Factor-Stimulated Actin Reorganization and Migration of Endothelial Cells Is Regulated via the Serine/Threonine Kinase Akt

• Published in: Circulation research Vol. 86; no. 8; pp. 892 - 896
• Main Authors: Morales-Ruiz, Manuel, Fulton, David, Sowa, Grzegorz, Languino, Lucia R, Fujio, Yasushi, Walsh, Kenneth, Sessa, William C
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD American Heart Association, Inc 28-04-2000; Lippincott
• Subjects: Actins - physiology; Actins - ultrastructure; Animals; Biological and medical sciences; Blood vessels and receptors; Cattle; Cell Movement - drug effects; Cell Movement - physiology; Cells, Cultured; Cytoskeleton - physiology; Cytoskeleton - ultrastructure; Endothelium, Vascular - cytology; Endothelium, Vascular - physiology; Fundamental and applied biological sciences. Psychology; Protein-Serine-Threonine Kinases - physiology; Signal Transduction - drug effects; Vertebrates: cardiovascular system; Molecular arrangement; Endothelial cell; Bovine; Enzyme; Transferases; Migration; Respiratory system; Angiogenesis; Vertebrata; Mammalia; Vascular endothelium growth factor; Pulmonary vessel; Actin; Protein kinase; Blood vessel; Animal; Nitric oxide; Aorta; Circulatory system; Artiodactyla; Ungulata
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/01.res.86.8.892

Vascular endothelial growth factor (VEGF) induces endothelial cell proliferation, migration, and actin reorganization, all necessary components of an angiogenic response. However, the distinct signal transduction mechanisms leading to each angiogenic phenotype are not known. In this study, we examined the ability of VEGF to stimulate cell migration and actin rearrangement in microvascular endothelial cells infected with adenoviruses encoding β-galactosidase (β-gal), activation-deficient Akt (AA-Akt), or constitutively active Akt (myr-Akt). VEGF increased cell migration in cells transduced with β-gal, whereas AA-Akt blocked VEGF-induced cell locomotion. Interestingly, myr-Akt transduction of bovine lung microvascular endothelial cells stimulated cytokinesis in the absence of VEGF, suggesting that constitutively active Akt, per se, can initiate the process of cell migration. Treatment of β-gal–infected endothelial cells with an inhibitor of NO synthesis blocked VEGF-induced migration but did not influence migration initiated by myr-Akt. In addition, VEGF stimulated remodeling of the actin cytoskeleton into stress fibers, a response abrogated by infection with dominant-negative Akt, whereas transduction with myr-Akt alone caused profound reorganization of F-actin. Collectively, these data demonstrate that Akt is critically involved in endothelial cell signal transduction mechanisms leading to migration and that the Akt/endothelial NO synthase pathway is necessary for VEGF-stimulated cell migration.