title: Hu antigen R is required for NOX-1 but not NOX-4 regulation by inflammatory stimuli in vascular smooth muscle cells.
abstract: OBJECTIVE
  NOX-1 and NOX-4 are key enzymes responsible for reactive oxygen species (ROS) generation in vascular smooth muscle cells (VSMC). The RNA-binding protein Hu antigen R (HuR) is implicated in posttranscriptional regulation of gene expression; however, its role regulating NOX is unknown. We investigated transcriptional and posttranscriptional mechanisms underlying angiotensin II (AngII) and IL-1β regulation of NOX-1 and NOX-4 in VSMC and their implications in cell migration.
  
  
  METHODS
  Rat and human VSMC were stimulated with AngII (0.1 μmol/l) and/or IL-1β (10 ng/ml). NOX-1 and NOX-4 mRNA and protein levels, NOX-1 and NOX-4 promoter and 3'UTR activities, NADPH oxidase activity, ROS production, and cell migration were studied.
  
  
  RESULTS
  IL-1β increased NOX-1 expression, NADPH oxidase activity and ROS production, and decreased NOX-4 expression and H2O2 production in VSMC. AngII potentiated the IL-1β-mediated induction of NOX-1 expression, NADPH oxidase activity, ROS production, and cell migration. However, AngII did not influence IL-1β-induced NOX-4 downregulation. AngII + IL-1β interfered with the decay of NOX-1 mRNA and promoted HuR binding to NOX-1 mRNA. Moreover, HuR blockade reduced NOX-1 mRNA stability and AngII + IL-1β-induced NOX-1 mRNA levels. IL-1β decreased NOX-4 expression through a transcriptional mechanism that involved response elements situated in the proximal promoter. AngII and/or IL-1β-induced cell migration were prevented by NOX-1 and HuR blockade and were augmented by NOX-4 overexpression.
  
  
  CONCLUSIONS
  In VSMC HuR-mediated mRNA stabilization is partially responsible for AngII + IL-1β-dependent NOX-1 expression, whereas transcriptional mechanisms are involved in decreased NOX-4 expression induced by IL-1β. NOX4 and HuR regulation of NOX-1 contributes to VSMC migration, important in vascular inflammation and remodeling.
authors.affiliation: aDepartment Farmacología, Universidad Autónoma de Madrid, Instituto de Investigación Hospital La Paz (IdiPAZ)bDepartment Immunology and Oncology, Centro Nacional de Biotecnología (CNB/CSIC), MadridcCentro de Investigación Cardiovascular (CSIC-ICCC), IIB-Sant Pau, Barcelona, SpaindDepartment Genomics, Transcriptomics and Molecular Therapies, Institute of Cellular Biology and Pathology 'Nicolae Simionescu', Bucharest, RomaniaeInstitute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UKfDepartment Ciencias Básicas de la Salud, Universidad Rey Juan Carlos, Alcorcón, SpaingDepartment Cancer Biology, University of Kansas Medical Center, Kansas City, USA*Ana M. Briones and Mercedes Salaices contributed equally to this article.
authors.forename: Andrea
authors.initials: A
authors.lastname: Aguado
authors.forename: Thierry
authors.initials: T
authors.lastname: Fischer
authors.forename: Cristina
authors.initials: C
authors.lastname: Rodríguez
authors.forename: Adrian
authors.initials: A
authors.lastname: Manea
authors.forename: José
authors.initials: J
authors.lastname: Martínez-González
authors.forename: Rhian M
authors.initials: RM
authors.lastname: Touyz
authors.forename: Raquel
authors.initials: R
authors.lastname: Hernanz
authors.forename: M Jesús
authors.initials: MJ
authors.lastname: Alonso
authors.forename: Dan A
authors.initials: DA
authors.lastname: Dixon
authors.forename: Ana M
authors.initials: AM
authors.lastname: Briones
authors.forename: Mercedes
authors.initials: M
authors.lastname: Salaices
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D000067780:ELAV-Like Protein 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D053583:Interleukin-1beta / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000201:enzymology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000201:enzymology; D009247:NADH, NADPH Oxidoreductases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D000074624:NADPH Oxidase 1; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020871:RNA Stability / Q000187:drug effects; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000067780:ELAV-Like Protein 1; D053583:Interleukin-1beta; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D000804:Angiotensin II; D006861:Hydrogen Peroxide; D009247:NADH, NADPH Oxidoreductases; D000074624:NADPH Oxidase 1; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C402799:NOX1 protein, human; C498910:NOX4 protein, human; C498911:Nox4 protein, rat