The interaction of neurons with their non-neuronal milieu plays a crucial role in the formation of neural networks, and wide variety of cell-contact-dependent signals that promote neurite elongation have been identified. In this study, we found that vascular endothelial cells promote neurite elongation in an integrin beta 3-dependent manner. Vascular endothelial cells from the cerebral cortex promoted neurite elongation of cortical neurons in a cell contact-dependent manner. This effect was mediated by arginine-glycine-aspartic acid (RGD), a major recognition sequence for integrins. Pharmacological blockade of integrin beta 3 abolished the neurite elongation effect induced by the endothelial cells. Immunocytochemical analysis revealed that integrin beta 3 was expressed on cultured cortical neurons. These results demonstrate that the neurite elongation promoted by vascular endothelial cells requires integrin beta 3. Vascular endothelial cells may therefore play a role in the development and repair of neural networks in the central nervous system. (C) 2014 Elsevier Inc. All rights reserved.