Local guidance of emerging vessel sprouts requires soluble Flt-1.
Blood vessel networks form via sprouting of endothelial cells from parent vessels. Extrinsic cues guide sprouts after they leave the initiation site, but these cues are likely insufficient to regulate initial outward movement, and many embryonic vessel networks form in the absence of a strong extrinsic gradient. We hypothesized that nascent sprouts are guided by spatial cues produced along their own vessels, and that soluble Flt-1 (sFlt-1) participates in this guidance. Analysis of developing vessels with perturbed flt-1 function revealed misguided emerging sprouts, and transgenic sFlt-1 rescued sprout guidance parameters. sflt-1 activity in endothelial cells immediately adjacent to the emerging sprout significantly improved local sprout guidance. Thus, we propose that a vessel-intrinsic system initially guides emerging sprouts away from the parent vessel, utilizing spatially regulated expression of sFlt-1 in conjunction with exogenous VEGF-A. Local sprout guidance defects are predicted to contribute to vessel dysmorphogenesis during perturbed development and disease.
Chappell
John C
JC
Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Taylor
Sarah M
SM
Ferrara
Napoleone
N
Bautch
Victoria L
VL
D000818:Animals; D001808:Blood Vessels / Q000196:embryology*; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000166:cytology*; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D018919:Neovascularization, Physiologic; D010641:Phenotype; D012160:Retina / Q000196:embryology; D012171:Retinal Vessels / Q000196:embryology; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000235:genetics* / Q000502:physiology*
D042461:Vascular Endothelial Growth Factor A; C501163:Flt1 protein, mouse; D040281:Vascular Endothelial Growth Factor Receptor-1