title: The C242T CYBA polymorphism of NADPH oxidase is associated with essential hypertension.
abstract: OBJECTIVE
  Oxidative stress is implicated in hypertension. The reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases are the main source of superoxide in phagocytic and vascular cells. The C242T polymorphism of CYBA, the human gene that encodes p22phox, has been found to be functionally associated with vascular NADPH oxidase activity in atherosclerotic patients. We investigated the association of the C242T polymorphism with hypertension and its potential impact on NADPH oxidase activity. We also analysed the interaction of C242T polymorphism with the -930A/G CYBA variant.
  
  
  METHODS
  Case-control study in a random sample of 623 subjects (326 hypertensive patients and 297 normotensive controls) from the general population.
  
  
  METHODS
  CYBA polymorphisms were determined by restriction fragment length polymorphism (RFLP) or allelic discrimination. NADPH oxidase activity and p22phox expression were quantified in phagocytic cells by chemiluminescence and by northern and western blots, respectively.
  
  
  RESULTS
  The prevalence of the CC genotype and the C allele frequency were significantly higher (P < 0.05) in hypertensives than in normotensives. CC genotype remained associated with hypertension after adjusting for potential confounders in a logistic regression analysis. Increased phagocytic NADPH oxidase activity was observed in CC hypertensives compared with CT and TT hypertensives (P < 0.05). Enhanced plasma levels of von Willebrand factor were found in CC hypertensives compared with TT hypertensives (P < 0.05). The C242T polymorphism was not in linkage disequilibrium with the -930A/G CYBA promoter variation, which also associates with hypertension.
  
  
  CONCLUSIONS
  The C242T CYBA polymorphism is associated with essential hypertension. Furthermore, hypertensives carrying the CC genotype of this polymorphism exhibit features of NADPH oxidase-mediated oxidative stress and endothelial damage.
authors.affiliation: Division of Cardiovascular Sciences, Centre for Applied Medical Research, Spain.
authors.forename: María U
authors.initials: MU
authors.lastname: Moreno
authors.forename: Gorka
authors.initials: G
authors.lastname: San José
authors.forename: Ana
authors.initials: A
authors.lastname: Fortuño
authors.forename: Oscar
authors.initials: O
authors.lastname: Beloqui
authors.forename: Javier
authors.initials: J
authors.lastname: Díez
authors.forename: Guillermo
authors.initials: G
authors.lastname: Zalba
mesh_terms: D005260:Female; D005838:Genotype; D006801:Humans; D006973:Hypertension / Q000201:enzymology* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D019255:NADPH Oxidases / Q000235:genetics* / Q000378:metabolism; D010586:Phagocytes / Q000201:enzymology; D011110:Polymorphism, Genetic / Q000235:genetics*; D013223:Statistics as Topic; D013481:Superoxides / Q000097:blood
chemical_list: D013481:Superoxides; D019255:NADPH Oxidases; C086986:CYBA protein, human