Neuropilin-1 is required for vascular development and is a mediator of VEGF-dependent angiogenesis in zebrafish

Abstract

Neuropilin-1 (NRP1) is a cell-surface receptor for both vascular endothelial growth factor 165 (VEGF165) and class 3 semaphorins that is expressed by neurons and endothelial cells. NRP1 is required for normal developmental angiogenesis in mice. The zebrafish is an excellent system for analyzing vascular development. Zebrafish intersegmental vessels correspond to mammalian capillary sprouts, whereas the axial vessels correspond to larger blood vessels, such as arteries. The zebrafish NRP1 gene (znrp1) was isolated and when overexpressed in cells, zNRP1 protein was a functional receptor for human VEGF 165. Whole-mount in situ hybridization showed that transcripts for znrp1 during embryonic and early larval development were detected mainly in neuronal and vascular tissues. Morpholino-mediated knockdown of zNRP1 in embryos resulted in vascular defects, most notably impaired circulation in the intersegmental vessels. Circulation via trunk axial vessels was not affected. Embryos treated with VEGF receptor-2 kinase inhibitor had a similar intersegmental vessel defect suggesting that knockdown of zNRP1 reduces VEGF activity. To determine whether NRP1 and VEGF activities were interdependent in vivo, zNRP1 and VEGF morpholinos were coinjected into embryos at concentrations that individually did not significantly inhibit blood vessel development. The result was a potent inhibition of blood cell circulation via both intersegmental and axial vessels demonstrating that VEGF and NRP1 act synergistically to promote a functional circulatory system. These results provide the first physiological demonstration that NRP1 regulates angiogenesis through a VEGF-dependent pathway.receptor kinase inhibitor ͉ vasculogenesis ͉ semaphorins ͉ antisense morpholino

Autocrine semaphorin 3A signaling promotes glioblastoma dispersal

“…In addition to its role as a Sema3A receptor, neuropilin-1 is a co-receptor for a specific isoform of VEGF165 and guides endothelial cell migration during vascular morphogenesis (Soker et al, 1998;Lee et al, 2002). The role of neuropilin-1 in tumors has been mostly studied in the context of its interaction with VEGF165 and related to tumor angiogenesis and tumor cell survival (Miao et al, 2000;Bachelder et al, 2001).…”

Neuropilin-1 and neuropilin-2 are differentially expressed in human proteinuric nephropathies and cytokine-stimulated proximal tubular cells

“…deficient mouse and zebrafish models established an essential role of NRP1 in the development of the embryonic nervous and cardiovascular systems. [20][21][22][23] NRPs are also highly expressed in diverse tumor cell lines and human neoplasms and have been implicated in tumor growth and vascularization. [2][3][4]24,25 More recently, it has been reported that NRP1 might have a role as a novel mediator of the primary immune response, as well as in tissue regeneration and repair.…”

“…[8][9][10] The cells (passages [20][21][22][23][24][25][26][27][28][29][30] were grown at 371C in a humidified 5% CO 2 atmosphere, and split at a 1:10 ratio, once a week. After growth to a subconfluent state, cells were washed once, made quiescent by incubation in serum-and supplementfree medium for 48 h, and then used for experiments.…”

Vascular endothelial growth factor receptor signaling is required for cardiac valve formation in zebrafish

“…The tyrosine kinase domain between human and zebrafish VEGF-R2/KDR is highly conserved (Habeck et al, 2002). In addition, PTK 787 has been shown to block vascular development in zebrafish embryos (Chan et al, 2002;Lee et al, 2002) and VEGF-induced autophoshorylation of zebrafish VEGF-R2/flk-1 (Chan et al, 2002). Hence, we used PTK 787, and additionally AAC 789, to test our hypothesis that signaling through VEGF-Rs is required for valve development.…”

“…Circulation through the heart was visualized by injecting FITC-dextran (Sigma) into the sinus venosa as described (Lee et al, 2002). Untreated and AAC 789-treated embryos were injected approximately 50 -56 hpf and visualized by fluorescence microscopy within 30 min of the injection.…”