01473nas a2200133   4500008004100000022001400041245011000055210006900165260000900234300000900243490000600252520103100258856005001289       2013                        eng d  a1937-914500aThe basis for the distinct biological activities of vascular endothelial growth factor receptor-1 ligands0 abasis for the distinct biological activities of vascular endothe  c2013  ara520 v63 a<p>Vascular endothelial growth factors (VEGFs) regulate blood and lymphatic vessel development through VEGF receptors (VEGFRs). The VEGFR immunoglobulin homology domain 2 (D2) is critical for ligand binding, and D3 provides additional interaction sites. VEGF-B and placenta growth factor (PlGF) bind to VEGFR-1 with high affinity, but only PlGF is angiogenic in most tissues. We show that VEGF-B, unlike other VEGFs, did not require D3 interactions for high-affinity binding. VEGF-B with a PlGF-derived L1 loop (B-L1(P)) stimulated VEGFR-1 activity, whereas PlGF with a VEGF-B-derived L1 loop (P-L1(B)) did not. Unlike P-L1(B) and VEGF-B, B-L1(P) and PlGF were also angiogenic in mouse skeletal muscle. Furthermore, B-L1(P) also bound to VEGFR-2 and activated downstream signaling. These results establish a role for L1-mediated D3 interactions in VEGFR activation in endothelial cells and indicate that VEGF-B is a high-affinity VEGFR-1 ligand that, unlike PlGF, cannot efficiently induce signaling downstream of VEGFR-1.</p>  uhttps://jeltsch.org/Anisimov2013b?language=fi01762nas a2200133   4500008004100000022001400041245014300055210006900198260001300267300001300280490000800293520127600301856005101577       2013                        eng d  a1477-912900aA truncation allele in vascular endothelial growth factor c reveals distinct modes of signaling during lymphatic and vascular development.0 atruncation allele in vascular endothelial growth factor c reveal  c2013 Apr  a1497-5060 v1403 a<p>Vascular endothelial growth factor C (Vegfc) is a secreted protein that guides lymphatic development in vertebrate embryos. However, its role during developmental angiogenesis is not well characterized. Here, we identify a mutation in zebrafish vegfc that severely affects lymphatic development and leads to angiogenesis defects on sensitized genetic backgrounds. The um18 mutation prematurely truncated Vegfc, blocking its secretion and paracrine activity but not its ability to activate its receptor Flt4. When expressed in endothelial cells, vegfc(um18) could not rescue lymphatic defects in mutant embryos, but induced ectopic blood vessel branching. Furthermore, vegfc-deficient endothelial cells did not efficiently contribute to tip cell positions in developing sprouts. Computational modeling together with assessment of endothelial cell dynamics by time-lapse analysis suggested that an autocrine Vegfc/Flt4 loop plays an important role in migratory persistence and filopodia stability during sprouting. Our results suggest that Vegfc acts in two distinct modes during development: as a paracrine factor secreted from arteries to guide closely associated lymphatic vasculature and as an autocrine factor to drive migratory persistence during angiogenesis.</p>  uhttps://jeltsch.org/Villefranc2013?language=fi