NOX2 and NOX4 mediate proliferative response in endothelial cells.
Increased levels of reactive oxygen species (ROS) contribute to many cardiovascular diseases. In neutrophils, ROS are generated by a NADPH oxidase containing p22phox and NOX2. NADPH oxidases are also major sources of vascular ROS. Whereas an active NOX2-containing enzyme has been described in endothelial cells, the contribution of recently identified NOX homologues to endothelial ROS production and proliferation has been controversial. The authors, therefore, compared the role of NOX2 with NOX4 and NOX1 in endothelial EaHy926 and human microvascular endothelial cells. NOX2 and NOX4 were abundantly expressed, whereas NOX1 expression was less prominent. NOX2, NOX4, and NOX1 were simultaneously present in a single cell in a perinuclear compartment. NOX2 and NOX4 co-localized with the endoplasmic reticulum (ER) marker calreticulin. Additionally, NOX2 co-localized with F-actin at the plasma membrane. NOX2 and NOX4, which interacted with p22phox, as was shown by bimolecular fluorescent complementation, contributed equally to endothelial ROS production and proliferation, whereas NOX1 depletion did not alter ROS levels under basal conditions. These data show that endothelial cells simultaneously express NOX2, NOX4, and NOX1. NOX2 and NOX4, but not NOX1, equally contributed to ROS generation and proliferation under basal conditions, indicating that a complex relation between NOX homologues controls endothelial function.
Petry
Andreas
A
Experimental Pediatric Cardiology, Department of Pediatric Cardiology and Congenital Heart Diseases, German Heart Center Munich at the Technical University Munich, Munich, Germany.
Djordjevic
Talija
T
Weitnauer
Michael
M
Kietzmann
Thomas
T
Hess
John
J
Görlach
Agnes
A
D000199:Actins / Q000378:metabolism; D037282:Calreticulin / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation; D004721:Endoplasmic Reticulum / Q000201:enzymology / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015870:Gene Expression / Q000235:genetics; D006801:Humans; D047468:Immunoprecipitation; D008562:Membrane Glycoproteins / Q000378:metabolism* / Q000502:physiology; D008861:Microsomes / Q000378:metabolism; D000074624:NADPH Oxidase 1; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D010766:Phosphorylation / Q000187:drug effects; D025941:Protein Interaction Mapping; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D014162:Transfection; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
D000199:Actins; D037282:Calreticulin; D008562:Membrane Glycoproteins; D047428:Protein Kinase Inhibitors; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; C056558:CYBB protein, human; D000074624:NADPH Oxidase 1; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C402799:NOX1 protein, human; C498910:NOX4 protein, human; C086986:CYBA protein, human; D048051:p38 Mitogen-Activated Protein Kinases