The expanding role of neuropilin: regulation of transforming growth factor-ß and platelet-derived growth factor signaling in the vasculature.

ABSTRACT

PURPOSE OF REVIEW Long recognized for its role in regulation of vascular endothelial growth factor signaling, neuropilin (Nrp)1 has emerged as a modulator of additional signaling pathways critical for vascular development and function. Here we review two novel functions of Nrp1 in blood vessels regulation of transforming growth factor-ß (TGFß) signaling in endothelial cells and regulation of platelet-derived growth factor (PDGF) signaling in vascular smooth muscle cells. RECENT FINDINGS: Novel mouse models demonstrate that Nrp1 fulfills vascular functions independent of vascular endothelial growth factor signaling. These include modulation of TGFß-dependent inhibition of endothelial sprouting during developmental angiogenesis and PDGF signaling in vascular smooth muscle cells during development and disease. SUMMARY: Broadening our understanding of how and where Nrp1 functions in the vasculature is critical for the development of targeted therapeutics for cancer and vascular diseases such as atherosclerosis and retinopathies.