Catalase C-262T Gene Variant in Patients with Bronchial Asthma

Abstract

SU M M A RYBronchial asthma (BA) is a chronic inflammatory disease of the airways in the pathogenesis of which oxidative stress has a very important role. Single nucleotide polymorphisms (SNPs) in catalase gene may result in decreased antioxidative defense capacity, and thus a higher risk for BA development. Since oxidative stress has an important role in the pathogenesis of BA and catalase has a key role in antioxidant defense, the aim of this study was to examine the association of CAT C-262T polymorphism with BA in Serbian patients with BA.A total of 170 subjects (79 patients with BA and 91 controls) were screened for CAT C-262T SNP using PCR-RFLP method.The analysis of genotype distribution did not show statistically significant differences between BA patients and controls (p > 0.05). Moreover, no differences were detected when comparison was performed based on dominant or recessive model. The distribution of CAT-262C and CAT-262T alleles did not show differences between patients and healthy controls (p = 0.715; OR = 1.091; 95% CI = 0.684-1.741). Further analysis of genotype and allele distributions, based on stratification by sex, did not show significant differences between BA patients and controls (p > 0.05). This is the first study that examined CAT C-262T (rs1001179) SNP in Serbian patients with BA. The results obtained in this study showed that biallelic SNP at the position -262 in the catalase gene is not associated with BA in the Serbian population. O r i g i n a l a r t i c l e I NT ROD U CT I ONBronchial asthma (BA) is a complex chronic inflammatory disease of the airways, the pathophysiology of which is not completely understood. It is considered that BA is a result of complex interaction between different genetic and environmental factors. Lungs are prone to damage caused by reactive oxygen species (ROS) due to the large surface that is directly exposed to high oxygen pressure and different irritants. Moreover, the lungs are exposed to microbes and the process of their elimination in order to keep airways sterile results in higher ROS production (1). High ROS levels, caused by increased ROS production or/and decreased antioxidant cellular capacity, results in oxidative stress which subsequently induces direct or indirect ROS-mediated damage of lipids, proteins and nucleic acids (2). Oxidative stress increases inflammation and bronchial hyperreactivity, stimulates bronchospasm and increases mucussecretion in BA (3).An adequate induction of antioxidant mechanisms is of great importance for the homeostasis of cellular functions. Under the physiological conditions, different enzymatic (catalase, superoxide-dismutase, glutathione peroxidase) and non-enzymatic (vitamins C and E, glutathione, bilirubin, coenzyme Q) antioxidant systems keep reducing the redox state. Catalase (E.C.1.11.1.6) is an antioxidant enzyme that decomposes hydrogen peroxide (H2O2) to molecular oxygen and water. It is present in almost all mammalian cells, mainly in peroxisomes and mitochondria with an exception of erythrocytes wh...