title: VEGF and VEGFR-2 (KDR) internalization is required for endothelial recovery during wound healing.
abstract: Vascular endothelial growth factor (VEGF) receptor activation regulates endothelial cell (EC) survival, migration and proliferation. Recently, it was suggested the cross-talk between the VEGF receptors-1 (FLT-1) and -2 (KDR) modulated several of these functions, but the detailed molecular basis for such interactions remained unexplained. Here we demonstrate for the first time that VEGF stimulation of EC monolayers induced a rapid FLT-1-mediated internalization of KDR to the nucleus, via microtubules and the endocytic pathway, internalization which required the activation of PI 3-kinase/AKT. KDR deletion mutants were generated in several tyrosine residues; in these, VEGF-induced KDR internalization was impaired, demonstrating this process required activation (phosphorylation) of the receptor. Furthermore, we demonstrate that in vitro wounding of EC monolayers leads to a rapid and transient internalization of VEGF+KDR to the nucleus, which is essential for monolayer recovery. Notably, FLT-1 blockade impedes VEGF and KDR activation and internalization, blocking endothelial monolayer recovery. Our data reveal a previously unrecognized mechanism induced by VEGF on EC, which regulates EC recovery following wounding, and as such indicate novel targets for therapeutic intervention.
authors: Angiogenesis Laboratory, Centro de Investigação em Patobiologia Molecular, Instituto Português de Oncologia Francisco Gentil-CROL, SA, Lisboa, Portugal.
authors: Susana Constantino Rosa
authors: SC
authors: Santos
authors: Cláudia
authors: C
authors: Miguel
authors: Ines
authors: I
authors: Domingues
authors: Angelo
authors: A
authors: Calado
authors: Zhenping
authors: Z
authors: Zhu
authors: Yan
authors: Y
authors: Wu
authors: Sérgio
authors: S
authors: Dias
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004705:Endocytosis; D042783:Endothelial Cells / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D006801:Humans; D051379:Mice; D008870:Microtubules / Q000502:physiology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D021381:Protein Transport; D020239:Receptor Cross-Talk; D015398:Signal Transduction; D014471:Umbilical Veins / Q000166:cytology; D042461:Vascular Endothelial Growth Factor A / Q000502:physiology*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*; D014945:Wound Healing / Q000502:physiology*
chemical_list: D042461:Vascular Endothelial Growth Factor A; D019869:Phosphatidylinositol 3-Kinases; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2