title: Brain-derived neurotrophic factor promotes angiogenic tube formation through generation of oxidative stress in human vascular endothelial cells.
abstract: OBJECTIVE
  Brain-derived neurotrophic factor (BDNF), a major type of neurotrophins, plays a role in the regulation of synaptic function. Recent studies suggest that BDNF promotes angiogenesis through its specific receptor, tropomyosin-related kinase B (TrkB). However, the detailed mechanisms for this still remain to be determined. Reactive oxygen species (ROS) generation contributes to the regulation of angiogenesis. Thus, we investigated the mechanisms by which BDNF regulates angiogenesis with focusing on ROS in cultured human vascular endothelial cells (ECs).
  
  
  RESULTS
  In human umbilical vein ECs, BDNF increased ROS generation as measured fluorometrically using 2' 7'-dichlorofluorescein diacetate as well as NADPH oxidase (NOX) activity as measured by lucigenin assay. BDNF-induced ROS generation and NOX activity were inhibited by K252a, a TrkB receptor inhibitor. BDNF induced phosphorylation of p47 phox, a regulatory component of NOX, which was inhibited by K252a as measured by Western blotting. BDNF increased angiogenic tube formation in ECs, which was completely inhibited by K252a or gp91ds-tat, a NOX inhibitor. BDNF caused Akt phosphorylation in ECs, which was inhibited by K252a or gp91ds-tat.
  
  
  CONCLUSIONS
  The present results for the first time demonstrate that BDNF induces NOX-derived ROS generation through activation of p47 phox in a TrkB receptor-dependent manner, which leads to the promotion of angiogenic tube formation possibly via Akt activation.
authors.affiliation: Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Towada, Aomori, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Usui
authors.forename: A
authors.initials: A
authors.lastname: Naruo
authors.forename: M
authors.initials: M
authors.lastname: Okada
authors.forename: Y
authors.initials: Y
authors.lastname: Hayabe
authors.forename: H
authors.initials: H
authors.lastname: Yamawaki
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D015153:Blotting, Western; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism*; D006801:Humans; D019255:NADPH Oxidases / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000502:physiology*; D018384:Oxidative Stress / Q000502:physiology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D034741:RNA, Small Interfering; D020813:Receptor, trkB / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D019208:Brain-Derived Neurotrophic Factor; D034741:RNA, Small Interfering; C553975:p37 protein, human; C579455:BDNF protein, human; D019255:NADPH Oxidases; D020813:Receptor, trkB; D051057:Proto-Oncogene Proteins c-akt
keywords: NADPH oxidase; angiogenesis; reactive oxygen species; vascular endothelial cell