title: The neuronal transcription factor NPAS4 is a strong inducer of sprouting angiogenesis and tip cell formation.
abstract: Regarding branching morphogenesis, neurogenesis and angiogenesis share common principle mechanisms and make use of the same molecules. Therefore, the investigation of neuronal molecules involved in vascular morphogenesis provides new possibilities for pro-angiogenic approaches in cardiovascular diseases.
  
  
  
  In this study, we investigated the role of the neuronal transcription factor NPAS4 in angiogenesis.
  
  
  
  Here, we demonstrate that the neuronal transcription factor NPAS4 is expressed in endothelial cells of different origin using reverse transcription PCR and western blot analysis. To investigate how NPAS4 affects endothelial cell function, NPAS4 was overexpressed by plasmid transfection or depleted from human umbilical vein endothelial cells (HUVECs) by specific siRNAs. In vitro HUVEC sprouting assays showed that sprouting and branching of endothelial cells was enhanced by NPAS4 overexpression. Consistently, silencing of NPAS4 resulted in reduced HUVEC sprouting and branching. Mechanistically, we identified as target gene vascular endothelial adhesion molecule VE-cadherin to be involved in the pro-angiogenic function of NPAS4. In endothelial cell mosaic spheroid sprouting assays, NPAS4 was involved in tip cell formation. In vivo experiments in mouse and zebrafish confirmed our in vitro findings. NPAS4-deficient mice displayed reduced ingrowth of endothelial cells in the Matrigel plug assay. Consistent with a regulatory role of NPAS4 in endothelial cell function silencing of NPAS4 in zebrafish by specific morpholinos resulted in perturbed intersegmental vessels growth.
  
  
  
  NPAS4 is expressed in endothelial cells, regulates VE-cadherin expression and regulates sprouting angiogenesis.
authors.affiliation: Cardiovascular Biology Group, Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Breisacher Str.33, 79106 Freiburg, Germany.
authors.forename: Jennifer Susanne
authors.initials: JS
authors.lastname: Esser
authors.affiliation: Cardiovascular Biology Group, Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Breisacher Str.33, 79106 Freiburg, Germany.|Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Charlet
authors.affiliation: Cardiovascular Biology Group, Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Breisacher Str.33, 79106 Freiburg, Germany.
authors.forename: Mei
authors.initials: M
authors.lastname: Schmidt
authors.affiliation: Cardiovascular Biology Group, Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Breisacher Str.33, 79106 Freiburg, Germany.
authors.forename: Sophia
authors.initials: S
authors.lastname: Heck
authors.affiliation: Cardiovascular Biology Group, Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Breisacher Str.33, 79106 Freiburg, Germany.|Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany.
authors.forename: Anita
authors.initials: A
authors.lastname: Allen
authors.affiliation: Cardiovascular Biology Group, Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Breisacher Str.33, 79106 Freiburg, Germany.|Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
authors.forename: Achim
authors.initials: A
authors.lastname: Lother
authors.affiliation: Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Epting
authors.affiliation: New York Presbyterian Hospital, Weill Cornell Medical Center, 525 East 68th Street, Payson 118, New York, NY, USA.
authors.forename: Cam
authors.initials: C
authors.lastname: Patterson
authors.affiliation: Cardiovascular Biology Group, Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Breisacher Str.33, 79106 Freiburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Bode
authors.affiliation: Cardiovascular Biology Group, Department of Cardiology and Angiology I, Heart Center, Faculty of Medicine, University of Freiburg, Breisacher Str.33, 79106 Freiburg, Germany; martin.moser@universitaets-herzzentrum.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Moser
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D005260:Female; D005838:Genotype; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism*; D006801:Humans; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009024:Morphogenesis; D018919:Neovascularization, Physiologic; D010641:Phenotype; D011554:Pseudopodia / Q000378:metabolism; D034622:RNA Interference; D015398:Signal Transduction; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D051792:Basic Helix-Loop-Helix Proteins; D015820:Cadherins; D014157:Transcription Factors; D029961:Zebrafish Proteins; D000099152:Cadherin 5; C481603:NPAS4 protein, human; C533005:Npas4 protein, mouse; C000623209:npas4a protein, zebrafish
keywords: Angiogenesis; Branching morphogenesis; Transcription factor