VEGF and VEGFR-2 (KDR) internalization is required for endothelial recovery during wound healing.
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.
Santos
Susana Constantino Rosa
SC
Angiogenesis Laboratory, Centro de Investigação em Patobiologia Molecular, Instituto Português de Oncologia Francisco Gentil-CROL, SA, Lisboa, Portugal.
Miguel
Cláudia
C
Domingues
Ines
I
Calado
Angelo
A
Zhu
Zhenping
Z
Wu
Yan
Y
Dias
Sérgio
S
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*
D042461:Vascular Endothelial Growth Factor A; D019869:Phosphatidylinositol 3-Kinases; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2