Vascular endothelial growth factor (VEGF) binds both VEGF receptor-1 (VEGFR-1) and VEGF receptor-2 (VEGFR-2). Activation of VEGFR-2 is thought to play a major role in the regulation of endothelial function by VEGF. Recently, specific ligands for VEGFR-1 have been reported to have beneficial effects when used to treat ischemic diseases. However, the role of VEGFR-1 in angiogenesis is not fully understood. In this study, we showed that VEGFR-1 performs "fine tuning" of VEGF signaling to induce neovascularization. We examined the effects of retroviral vectors expressing a small interference RNA that targeted either the VEGFR-1 gene or the VEGFR-2 gene. Deletion of either VEGFR-1 or VEGFR-2 reduced the ability of endothelial cells to form capillaries. Deletion of VEGFR-1 markedly reduced endothelial cell proliferation and induced premature senescence of endothelial cells. In contrast, deletion of VEGFR-2 significantly impaired endothelial cell survival. When VEGFR-1 expression was blocked, VEGF constitutively activated Akt signals and thus induced endothelial cell senescence via a p53-dependent pathway. VEGFR-1 mice exhibited an increase of endothelial Akt activity and showed an impaired neovascularization in response to ischemia, and this impairment was ameliorated in VEGFR-1 Akt1 mice. These results suggest that VEGFR-1 plays a critical role in the maintenance of endothelial integrity by modulating the VEGF/Akt signaling pathway. © 2008 American Heart Association, Inc.
CITATION STYLE
Nishi, J. I., Minamino, T., Miyauchi, H., Nojima, A., Tateno, K., Okada, S., … Komuro, I. (2008). Vascular endothelial growth factor receptor-1 regulates postnatal angiogenesis through inhibition of the excessive activation of akt. Circulation Research, 103(3), 261–268. https://doi.org/10.1161/CIRCRESAHA.108.174128
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