title: Endothelial NADPH oxidase-2 promotes interstitial cardiac fibrosis and diastolic dysfunction through proinflammatory effects and endothelial-mesenchymal transition.
abstract: OBJECTIVE
  This study sought to investigate the effect of endothelial dysfunction on the development of cardiac hypertrophy and fibrosis.
  
  
  BACKGROUND
  Endothelial dysfunction accompanies cardiac hypertrophy and fibrosis, but its contribution to these conditions is unclear. Increased nicotinamide adenine dinucleotide phosphate oxidase-2 (NOX2) activation causes endothelial dysfunction.
  
  
  METHODS
  Transgenic mice with endothelial-specific NOX2 overexpression (TG mice) and wild-type littermates received long-term angiotensin II (AngII) infusion (1.1 mg/kg/day, 2 weeks) to induce hypertrophy and fibrosis.
  
  
  RESULTS
  TG mice had systolic hypertension and hypertrophy similar to those seen in wild-type mice but developed greater cardiac fibrosis and evidence of isolated left ventricular diastolic dysfunction (p < 0.05). TG myocardium had more inflammatory cells and VCAM-1-positive vessels than did wild-type myocardium after AngII treatment (both p < 0.05). TG microvascular endothelial cells (ECs) treated with AngII recruited 2-fold more leukocytes than did wild-type ECs in an in vitro adhesion assay (p < 0.05). However, inflammatory cell NOX2 per se was not essential for the profibrotic effects of AngII. TG showed a higher level of endothelial-mesenchymal transition (EMT) than did wild-type mice after AngII infusion. In cultured ECs treated with AngII, NOX2 enhanced EMT as assessed by the relative expression of fibroblast versus endothelial-specific markers.
  
  
  CONCLUSIONS
  AngII-induced endothelial NOX2 activation has profound profibrotic effects in the heart in vivo that lead to a diastolic dysfunction phenotype. Endothelial NOX2 enhances EMT and has proinflammatory effects. This may be an important mechanism underlying cardiac fibrosis and diastolic dysfunction during increased renin-angiotensin activation.
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom.
authors.forename: Colin E
authors.initials: CE
authors.lastname: Murdoch
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Chaubey
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom.
authors.forename: Lingfang
authors.initials: L
authors.lastname: Zeng
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom.
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom.
authors.forename: Aleksander
authors.initials: A
authors.lastname: Ivetic
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Walker
authors.affiliation: Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands.
authors.forename: Davy
authors.initials: D
authors.lastname: Vanhoutte
authors.affiliation: Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands.
authors.forename: Stephane
authors.initials: S
authors.lastname: Heymans
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom.
authors.forename: David J
authors.initials: DJ
authors.lastname: Grieve
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom.
authors.forename: Alison C
authors.initials: AC
authors.lastname: Cave
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom.
authors.forename: Alison C
authors.initials: AC
authors.lastname: Brewer
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: King's College London British Heart Foundation Centre of Excellence, Cardiovascular Division, London, United Kingdom. Electronic address: ajay.shah@kcl.ac.uk.
authors.forename: Ajay M
authors.initials: AM
authors.lastname: Shah
mesh_terms: D000818:Animals; D006332:Cardiomegaly / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000201:enzymology* / Q000473:pathology; D005355:Fibrosis / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D054144:Heart Failure, Diastolic / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D006801:Humans; D018836:Inflammation Mediators / Q000502:physiology*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000502:physiology*; D059630:Mesenchymal Stem Cells / Q000201:enzymology* / Q000473:pathology; D051379:Mice; D008822:Mice, Transgenic; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000235:genetics / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000201:enzymology* / Q000235:genetics / Q000473:pathology
chemical_list: D018836:Inflammation Mediators; D008562:Membrane Glycoproteins; C488842:Cybb protein, mouse; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases
keywords: NADPH (nicotinamide adenine dinucleotide phosphate) oxidase; angiotensin II; diastolic dysfunction; endothelial-mesenchymal transition; endothelium