Soluble Robo4 receptor inhibits in vivo angiogenesis and endothelial cell migration.
Roundabout receptors are molecular guidance molecules that function by interaction with Slit proteins to regulate axon guidance, neuronal migration, and leukocyte chemotaxis. We recently isolated a novel roundabout gene, called Robo4, which is restricted in expression to the endothelium, notably in areas of angiogenesis. The aim of this study was to use the soluble extracellular domain of Robo4 as a probe of function in angiogenesis and endothelial biology. Thus, the soluble extracellular domain of the receptor (Robo4Fc) showed diverse in vivo and in vitro activities including 1) inhibition of angiogenesis in vivo in the rodent subcutaneous sponge model, 2) inhibition of tube formation in the rat aortic ring assay, 3) inhibition of VEGF- and bFGF-stimulated endothelial cell migration, and 4) inhibition of endothelial proliferation. To assess whether Robo4Fc was inhibiting Slit-mediated effects, we determined whether Robo4 and Slit interact. Recombinant Slits-1, -2, and -3 were shown by immunoprecipitation and BiaCore analysis to bind to Robo1 but not Robo4. Further study of the role of Robo4 in angiogenesis appears justified.
Molecular Angiogenesis Laboratory, Cancer Research UK, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK.
Steven
S
Suchting
Paul
P
Heal
Kiki
K
Tahtis
Lorna M
LM
Stewart
Roy
R
Bicknell
D000818:Animals; D002465:Cell Movement / Q000502:physiology; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D006801:Humans; D007128:Immunoglobulin Fragments / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D009369:Neoplasms / Q000098:blood supply / Q000378:metabolism; D009389:Neovascularization, Pathologic / Q000378:metabolism* / Q000517:prevention & control; D018919:Neovascularization, Physiologic / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012995:Solubility; D014471:Umbilical Veins / Q000166:cytology; D000097905:Roundabout Proteins; D000098552:Slit Homolog 2 Protein
D007128:Immunoglobulin Fragments; D036341:Intercellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D010455:Peptides; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D011993:Recombinant Fusion Proteins; D000097905:Roundabout Proteins; D000098552:Slit Homolog 2 Protein; C462951:ROBO4 protein, human