An association between polymorphism of the NADH/NADPH oxidase p22phox (phagocyte oxidase) subunit and aging in Turkish population

Abstract

Aging is a complex and multifactorial process that is stimulated by a number of factors including genes and life-style. It is thought that the production of reactive oxygen species (ROS) in the face of antioxidant enzymes and molecules is related to aging and age-related diseases. NAD(P)H oxidase system is the predominant cellular source of ROS, and p22phox, the major component of that system, is essential for the activation of NAD(P)H oxidase. The aim of this study was to investigate the association between p22phox C242T single nucleotide polymorphism and aging in Turkish population. Blood samples were collected from 332 volunteers between 18 and 95 years of age and were classified into three groups according to their ages as <65, 65-84 and ≥ 85. p22phox C242T polymorphism was genotyped by PCR-RFLP method. CC genotype frequency in the C242T polymorphism is higher in older group (≥ 85) than younger groups (<65 and 65-85), whereas CT + TT genotype frequency is lower in older group. When the p22phox C242T polymorphism was compared with the mean ages and age groups, statistically significant associations were found. We showed for the first time that human aging is significantly associated with p22phox C242T genotypes in Turkish population, being highest in CC, intermediate in CT, and lowest in TT homozygote. It is plausible to suggest that CC genotype might protect people from chronic inflammation, diseases as well as from oxidative stress and, thus, individuals with CC genotype might be more advantageous for aging as compared to those with CT + TT genotypes.