C242T CYBA Polymorphism of the NADPH Oxidase Is Associated With Reduced Respiratory Burst in Human Neutrophils

Abstract

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 p22 phox is identical to neutrophil p22 phox , we studied the association between the C242T, A640G, and Ϫ930 A/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 8.7Ϯ0.7, 7.9Ϯ0.6, and 5.9Ϯ1.2 mol/L per minute per 10 6 neutrophils for the C242T CC, CT, and TT genotypes, respectively (PϽ0.05). In contrast, the A640G and the Ϫ930

Genetic polymorphisms of NAD(P)H oxidase: variation in subunit expression and enzyme activity

“…We could not demonstrate a consistent impact of this variant on enzyme activity. Only when restricting analysis to repeated measurements at two different study days (a subgroup of n ¼ 54 from the first study), we detected a similar effect as Wyche et al, 20 who reported about 30% less activity for the TT-allele status. In contrast, another group has reported an increased superoxide formation for the 242T allele.…”

“…19 This finding was confirmed in neutrophilic granulocytes albeit only under stimulated conditions. 20 In marked contrast, another group observed significantly higher superoxide production in carriers of the 242T allele. 21 Gardemann et al 22 delineated an association of the 640A4G polymorphism in the 3 0 UTR of CYBA with cardiovascular arterial disease, in particular in hypertensives.…”

“…However, a functional impact of this SNP on NAD(P)H oxidase activity could not be proven. 20 In summary, polymorphisms in NAD(P)H oxidase may be highly relevant for various diseases but the present functional and clinical-epidemiological data are inconclusive.…”

Physical activity modifies the association between CYBA gene polymorphisms and small artery elasticity in a Chinese population

“…Accordingly, we found similar results for the C2 response across the genotypes, with a significant difference observed between AA and GG/AG carriers. But MaciasReyes et al 10 found opposite results, whereas Wyche et al 12 failed to find any relationship. Accordingly, associations between the rs1049255 polymorphism and vascular complications have been contradictory.…”

“…Among these, rs1049255 (A640G) has been widely discussed in the context of cardiovascular diseases; however, the results have been conflicting. [9][10][11][12] For rs7195830, there have been few studies related to cardiovascular diseases. Rather, rs7195830 has been mentioned in studies on non-Hodgkin lymphoma and cervical cancer as an oxidative stress-related locus.…”