title: Notch ligand Delta-like 1 is essential for postnatal arteriogenesis.
abstract: Growth of functional arteries is essential for the restoration of blood flow to ischemic organs. Notch signaling regulates arterial differentiation upstream of ephrin-B2 during embryonic development, but its role during postnatal arteriogenesis is unknown. Here, we identify the Notch ligand Delta-like 1 (Dll1) as an essential regulator of postnatal arteriogenesis. Dll1 expression was specifically detected in arterial endothelial cells, but not in venous endothelial cells or capillaries. During ischemia-induced arteriogenesis endothelial Dll1 expression was strongly induced, Notch signaling activated and ephrin-B2 upregulated, whereas perivascular cells expressed proangiogenic vascular endothelial growth factor, and the ephrin-B2 activator EphB4. In heterozygous Dll1 mutant mice endothelial Notch activation and ephrin-B2 induction after hindlimb ischemia were absent, arterial collateral growth was abrogated and recovery of blood flow was severely impaired, but perivascular vascular endothelial growth factor and EphB4 expression was unaltered. In vitro, angiogenic growth factors synergistically activated Notch signaling by induction of Dll1, which was necessary and sufficient to regulate ephrin-B2 expression and to induce ephrin-B2 and EphB4-dependent branching morphogenesis in human arterial EC. Thus, Dll1-mediated Notch activation regulates ephrin-B2 expression and postnatal arteriogenesis.
authors.affiliation: Department of Cardiology, Medizinische Hochschule Hannover, Hannover, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Limbourg
authors.forename: Merlin
authors.initials: M
authors.lastname: Ploom
authors.forename: Diana
authors.initials: D
authors.lastname: Elligsen
authors.forename: Inga
authors.initials: I
authors.lastname: Sörensen
authors.forename: Tibor
authors.initials: T
authors.lastname: Ziegelhoeffer
authors.forename: Achim
authors.initials: A
authors.lastname: Gossler
authors.forename: Helmut
authors.initials: H
authors.lastname: Drexler
authors.forename: Florian P
authors.initials: FP
authors.lastname: Limbourg
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D001158:Arteries / Q000737:chemistry / Q000166:cytology* / Q000254:growth & development; D002135:Calcium-Binding Proteins; D002196:Capillaries / Q000737:chemistry; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D003097:Collateral Circulation / Q000502:physiology; D003250:Constriction; D016895:Culture Media, Serum-Free; D042783:Endothelial Cells / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology*; D005786:Gene Expression Regulation / Q000502:physiology*; D020868:Gene Silencing; D006614:Hindlimb / Q000098:blood supply; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D007511:Ischemia / Q000209:etiology / Q000235:genetics / Q000503:physiopathology*; D008565:Membrane Proteins / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D009024:Morphogenesis / Q000235:genetics / Q000502:physiology; D018919:Neovascularization, Physiologic / Q000235:genetics / Q000502:physiology*; D009928:Organ Specificity; D034741:RNA, Small Interfering / Q000494:pharmacology; D036183:Receptor, EphB2 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D036224:Receptor, EphB4 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D051880:Receptors, Notch / Q000502:physiology*; D014680:Veins / Q000737:chemistry
chemical_list: D002135:Calcium-Binding Proteins; D016895:Culture Media, Serum-Free; C512941:DLK1 protein, human; C512925:Dlk1 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D034741:RNA, Small Interfering; D051880:Receptors, Notch; C086681:Ephb4 protein, mouse; D036183:Receptor, EphB2; D036224:Receptor, EphB4