title: Endothelial Jagged1 antagonizes Dll4 regulation of endothelial branching and promotes vascular maturation downstream of Dll4/Notch1.
abstract: OBJECTIVE
  Notch signaling controls cardiovascular development and has been associated with several pathological conditions. Among its ligands, Jagged1 and Dll4 were shown to have opposing effects in developmental angiogenesis, but the underlying mechanism and the role of Jagged1/Notch signaling in adult angiogenesis remain incompletely understood. The current study addresses the importance of endothelial Jagged1-mediated Notch signaling in the context of adult physiological angiogenesis and the interactions of Jagged1 and Dll4 on angiogenic response and vascular maturation processes.
  
  
  RESULTS
  The role of endothelial Jagged1 in wound healing kinetics and angiogenesis was investigated with endothelial-specific Jag1 gain-of-function and loss-of-function mouse mutants (eJag1OE and eJag1cKO). To study the interactions between the 2 Notch ligands, genetic mouse models were combined with pharmacological inhibition of Dll4 or Jagged1, respectively. Jagged1 overexpression in endothelial cells increased vessel density, maturation, and perfusion, thus accelerating wound healing. The opposite effect was seen in eJag1cKO animals. Interestingly, Dll4 blockade in these animals led to an increase in vascular density but induced a greater decrease in perivascular cell coverage. However, Jagged1 inhibition in Dll4 gain-of-function (eDll4OE) mutants, with reduced angiogenesis, further diminished angiogenic growth and hampered perivascular cell coverage. Our findings suggest that as Dll4 blocks endothelial activation through Notch1 signaling, it also induces Jagged1 expression. Jagged1 then blocks Dll4 signaling through Notch1, allowing endothelial activation by vascular endothelial growth factor and endothelial layer growth. Jagged1 also initiates maturation of the newly formed vessels, possibly by binding and activating endothelial Notch4. Importantly, mice administered with a Notch4 agonistic antibody mimicked the mural cell phenotype of eJag1OE mutants without affecting angiogenic growth, which is thought to be Notch1 dependent.
  
  
  CONCLUSIONS
  Endothelial Jagged1 is likely to operate downstream of Dll4/Notch1 signaling to activate Notch4 and regulate vascular maturation. Thus, Jagged1 not only counteracts Dll4/Notch in the endothelium but also generates a balance between angiogenic growth and maturation processes in vivo.
authors.affiliation: From the Centro Interdisciplinar de Investigação em Sanidade Animal (CIISA), University of Lisbon, Lisbon, Portugal (A.-R.P., A.T., A.-C.F., C.C., J.G., A.T.T., A.D.); Instituto Gulbenkian de Ciência, Oeiras, Portugal (A.T., A.T.T., A.D.); Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Muenster, Faculty of Medicine, Muenster, Germany (R.D.-H., R.H.A.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y.).
authors.forename: Ana-Rita
authors.initials: AR
authors.lastname: Pedrosa
authors.affiliation: From the Centro Interdisciplinar de Investigação em Sanidade Animal (CIISA), University of Lisbon, Lisbon, Portugal (A.-R.P., A.T., A.-C.F., C.C., J.G., A.T.T., A.D.); Instituto Gulbenkian de Ciência, Oeiras, Portugal (A.T., A.T.T., A.D.); Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Muenster, Faculty of Medicine, Muenster, Germany (R.D.-H., R.H.A.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y.). aduarte@fmv.ulisboa.pt adtrindade@fmv.ulisboa.pt.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Trindade
authors.affiliation: From the Centro Interdisciplinar de Investigação em Sanidade Animal (CIISA), University of Lisbon, Lisbon, Portugal (A.-R.P., A.T., A.-C.F., C.C., J.G., A.T.T., A.D.); Instituto Gulbenkian de Ciência, Oeiras, Portugal (A.T., A.T.T., A.D.); Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Muenster, Faculty of Medicine, Muenster, Germany (R.D.-H., R.H.A.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y.).
authors.forename: Ana-Carina
authors.initials: AC
authors.lastname: Fernandes
authors.affiliation: From the Centro Interdisciplinar de Investigação em Sanidade Animal (CIISA), University of Lisbon, Lisbon, Portugal (A.-R.P., A.T., A.-C.F., C.C., J.G., A.T.T., A.D.); Instituto Gulbenkian de Ciência, Oeiras, Portugal (A.T., A.T.T., A.D.); Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Muenster, Faculty of Medicine, Muenster, Germany (R.D.-H., R.H.A.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y.).
authors.forename: Catarina
authors.initials: C
authors.lastname: Carvalho
authors.affiliation: From the Centro Interdisciplinar de Investigação em Sanidade Animal (CIISA), University of Lisbon, Lisbon, Portugal (A.-R.P., A.T., A.-C.F., C.C., J.G., A.T.T., A.D.); Instituto Gulbenkian de Ciência, Oeiras, Portugal (A.T., A.T.T., A.D.); Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Muenster, Faculty of Medicine, Muenster, Germany (R.D.-H., R.H.A.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y.).
authors.forename: Joana
authors.initials: J
authors.lastname: Gigante
authors.affiliation: From the Centro Interdisciplinar de Investigação em Sanidade Animal (CIISA), University of Lisbon, Lisbon, Portugal (A.-R.P., A.T., A.-C.F., C.C., J.G., A.T.T., A.D.); Instituto Gulbenkian de Ciência, Oeiras, Portugal (A.T., A.T.T., A.D.); Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Muenster, Faculty of Medicine, Muenster, Germany (R.D.-H., R.H.A.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y.).
authors.forename: Ana Teresa
authors.initials: AT
authors.lastname: Tavares
authors.affiliation: From the Centro Interdisciplinar de Investigação em Sanidade Animal (CIISA), University of Lisbon, Lisbon, Portugal (A.-R.P., A.T., A.-C.F., C.C., J.G., A.T.T., A.D.); Instituto Gulbenkian de Ciência, Oeiras, Portugal (A.T., A.T.T., A.D.); Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Muenster, Faculty of Medicine, Muenster, Germany (R.D.-H., R.H.A.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y.).
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Diéguez-Hurtado
authors.affiliation: From the Centro Interdisciplinar de Investigação em Sanidade Animal (CIISA), University of Lisbon, Lisbon, Portugal (A.-R.P., A.T., A.-C.F., C.C., J.G., A.T.T., A.D.); Instituto Gulbenkian de Ciência, Oeiras, Portugal (A.T., A.T.T., A.D.); Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Muenster, Faculty of Medicine, Muenster, Germany (R.D.-H., R.H.A.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y.).
authors.forename: Hideo
authors.initials: H
authors.lastname: Yagita
authors.affiliation: From the Centro Interdisciplinar de Investigação em Sanidade Animal (CIISA), University of Lisbon, Lisbon, Portugal (A.-R.P., A.T., A.-C.F., C.C., J.G., A.T.T., A.D.); Instituto Gulbenkian de Ciência, Oeiras, Portugal (A.T., A.T.T., A.D.); Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Muenster, Faculty of Medicine, Muenster, Germany (R.D.-H., R.H.A.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y.).
authors.forename: Ralf H
authors.initials: RH
authors.lastname: Adams
authors.affiliation: From the Centro Interdisciplinar de Investigação em Sanidade Animal (CIISA), University of Lisbon, Lisbon, Portugal (A.-R.P., A.T., A.-C.F., C.C., J.G., A.T.T., A.D.); Instituto Gulbenkian de Ciência, Oeiras, Portugal (A.T., A.T.T., A.D.); Department of Tissue Morphogenesis, Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Muenster, Faculty of Medicine, Muenster, Germany (R.D.-H., R.H.A.); and Department of Immunology, Juntendo University School of Medicine, Tokyo, Japan (H.Y.). aduarte@fmv.ulisboa.pt adtrindade@fmv.ulisboa.pt.
authors.forename: António
authors.initials: A
authors.lastname: Duarte
mesh_terms: D043924:Angiogenesis Modulating Agents / Q000494:pharmacology*; D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D000072100:Jagged-1 Protein; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D018919:Neovascularization, Physiologic / Q000187:drug effects* / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011897:Random Allocation; D051881:Receptor, Notch1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000074562:Receptor, Notch4; D051880:Receptors, Notch / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D043924:Angiogenesis Modulating Agents; D002135:Calcium-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; C000606274:Jag1 protein, mouse; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D051881:Receptor, Notch1; D000074562:Receptor, Notch4; D051880:Receptors, Notch; D000072099:Serrate-Jagged Proteins; D042461:Vascular Endothelial Growth Factor A; C073572:Notch4 protein, mouse
keywords: Jagged1 protein; Notch proteins; angiogenesis modulators; wound healing