Overexpression of delta-like 4 induces arterialization and attenuates vessel formation in developing mouse embryos.
The importance of Notch signaling pathway in the regulation of vascular development and angiogenesis is suggested by the expression of Notch receptors and ligands in vascular endothelial cells (ECs) and the observed vascular phenotypes in mutants of Notch receptors or ligands, especially Dll4. DLL4 is specifically expressed in arterial ECs during development, and haplo-insufficiency is embryonically lethal in mice. To address the role of Dll4 in vascular development, we produced mDll4 conditionally overexpressed transgenic mice that were crossed with constitutive recombinase cre lines. Double transgenic embryos displayed grossly enlarged dorsal aortae (DA) and died before embryonic day 10.5 (E10.5), showing a variable degree of premature arteriovenous fusion. Veins displayed ectopic expression of arterial markers. Other defects included reduced vascular sprouting, EC proliferation, and migration. mDll4 overexpression also inhibited VEGF signaling and increased fibronectin accumulation around the vessels. In vitro and in vivo studies of DLL4-FL (Dll4-full-length) in ECs recapitulate many of the mDll4 transgenics findings, including decreased tube formation, reduced vascular branching, fewer vessels, increased pericyte recruitment, and increased fibronectin expression. These results establish the role of Dll4 in arterial identity determination, and regulation of angiogenesis subject to dose and location.
Centro de Informatica do Instituto Superior de Agronomia (CIISA), Lisbon Technical University, Lisbon, Portugal.
Alexandre
A
Trindade
S Ram
SR
Kumar
Jeffrey S
JS
Scehnet
Luis
L
Lopes-da-Costa
Jorg
J
Becker
Weidong
W
Jiang
Ren
R
Liu
Parkash S
PS
Gill
Antonio
A
Duarte
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001158:Arteries / Q000002:abnormalities / Q000196:embryology; D002135:Calcium-Binding Proteins; D002465:Cell Movement; D002478:Cells, Cultured; D020964:Embryo Loss / Q000235:genetics; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology; D005260:Female; D005318:Fetal Heart / Q000002:abnormalities / Q000196:embryology; D018628:Gene Dosage; D018507:Gene Expression Regulation, Developmental; D005865:Gestational Age; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000502:physiology*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D018919:Neovascularization, Physiologic / Q000235:genetics* / Q000502:physiology*; D010641:Phenotype; D011247:Pregnancy; D051880:Receptors, Notch / Q000502:physiology; D014162:Transfection; D014680:Veins / Q000002:abnormalities / Q000196:embryology
D048868:Adaptor Proteins, Signal Transducing; D002135:Calcium-Binding Proteins; C424126:DLL4 protein, human; C519665:DLL4 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D051880:Receptors, Notch