7500a789-7f10-448f-bd79-03a9d21635a2
title
C242T CYBA  polymorphism of the  NADPH oxidase  is associated with reduced respiratory burst in human neutrophils.
74a645a7-e0c4-474a-bc75-db8f7521c116
abstract
Oxidative stress contributes to the pathogenesis of atherosclerosis.  p22phox-based NAD(P)H oxidases  exist in the vessel wall, acting as important superoxide-generating systems in the vasculature. Some studies have identified reduced atherosclerosis in the presence of the  C242T   CYBA  polymorphism, whereas others have not. Because vascular  p22phox  is identical to neutrophil  p22phox , we studied the association between the  C242T ,  A640G , and  -930A/G   CYBA  polymorphisms and the quantity of superoxide produced from neutrophils isolated from healthy adults to determine if these polymorphisms had any functional impact on  NADPH oxidase  function. Neutrophils were isolated from 90 subjects by Percoll density gradient centrifugation. Genotypes were determined by polymerase chain reaction (PCR) and restriction mapping, as well as real-time PCR. The oxidative burst was stimulated with phorbol 12-myristate 13-acetate. Superoxide was quantified using the  superoxide dismutase  inhibitable oxidation of the spin probe hydroxylamine 1-hydroxy-3-carboxy-pyrrolidine, detected by electron paramagnetic resonance. Superoxide production was significantly affected by the  C242T  polymorphism, being 8.7+/-0.7, 7.9+/-0.6, and 5.9+/-1.2 micromol/L per minute per 10(6) neutrophils for the  C242T  CC, CT, and TT genotypes, respectively (P<0.05). In contrast, the  A640G  and the  -930A/G  polymorphisms did not alter the neutrophil respiratory burst. Phagocytic respiratory burst activity in homozygous individuals with the T allele of the  C242T   CYBA  polymorphism is significantly lower than of wild-type carriers and heterozygous individuals. Because  p22phox  exists in both the neutrophil and vessel wall, vascular oxidative stress is likely diminished in individuals with this polymorphism.