Prevalence of catalase (-21 A/T) gene variant in south Indian (Tamil) population

Antioxidant enzymes and association of CAT SNP-21 A/T (rs7943316) with male infertility

Infertility is a multifactorial and polygenic disease. A vast majority of infertility is still unexplained despite modern diagnostic techniques. Oxidative stress is considered a factor for male infertility but etiology in terms of functional gene polymorphism and experimental studies on human subjects is scarcely reported. The aim of the study was to investigate the status of three antioxidant enzymes; catalase, superoxide dismutase (SOD), and glutathione reduced (GSH) in clinically diagnosed infertile males and find the potential association of CAT gene variant in the promoter region -21 A/T (rs7943316). The study consisted of 55 clinically diagnosed infertile males and 50 non-infertile volunteers. The activity of antioxidant enzymes was measured through a spectrophotometer. Polymerase chain reaction-restriction fragment length polymorphism was performed for genotyping of single-nucleotide polymorphism. Catalase enzyme activity was significantly decreased while SOD and GSH were substantially increased (p ≤ 0.01) in infertile men in comparison to non-infertile. CAT gene variant rs7943316 had shown significant association in dominant, recessive model and allelic frequencies. The study concludes that rs7943316 has a substantial role in male infertility. The outcome of the study may help in resolving idiopathic infertility cases and may help in evolving novel diagnostic and therapeutic approaches. Other variants of CAT and antioxidant genes are suggested to ascertain further insight.

Status of Catalase, Glutathione Peroxidase, Glutathione S-Transferase, and Myeloperoxidase Gene Polymorphisms in Beta-Thalassemia Major Patients to Assess Oxidative Injury and Its Association with Enzyme Activities

Beta-thalassemic patients require regular blood transfusion to sustain their life which leads to iron overload and causes oxidative stress. The aim of this study was to investigate the status of variants in genes including GSTM1, GSTT1 (null/present), CT-262 (C > T) and CT-89 (A > T), glutathione peroxidase (GPx), and myeloperoxidase (MPO). The genotype studies were conducted with 200 thalassemia major (TM) patients and 200 healthy controls. Genotyping of GST gene was performed by multiplex polymerase chain reaction (PCR), whereas for CT, GPx and MPO genesvariants PCR- restriction fragment length polymorphism technique used. However, the enzyme activities were measured only in the patients group to assess the association with the genotypes. All enzyme estimations were performed by ELISA. We observed higher frequency of GSTT1 null, CT-89 (A > T), GPx1 198 (C > T) and MPO-463 (G > A) polymorphisms in TM patient than healthy controls. However, CT-262 (C > T) polymorphism was not found to be statistically significantly different between patients and controls. Our results suggest that frequency of null allele of glutathione-S-transferase is significantly high among TM patients. The other alleles CT-89 (A > T), GPx1 198 (C > T), and MPO-463 (G > A) are linked to decreased CT, GPX, and MPO enzyme activities.

Genetic polymorphisms of antioxidant enzymes CAT and SOD affect the outcome of clinical, biochemical, and anthropometric variables in people with obesity under a dietary intervention

BACKGROUND

Genetic polymorphisms of antioxidant enzymes CAT, GPX, and SOD are involved in the etiology of obesity and its principal comorbidities. The aim of the present study was to analyze the effect of aforementioned SNPs over the output of several variables in people with obesity after a nutritional intervention. The study included 92 Mexican women, which received a dietary intervention by 3 months. Participants were genotyped and stratified into two groups: (1) carriers; mutated homozygous plus heterozygous (CR) and (2) homozygous wild type (WT). A comparison between CR and WT was done in clinical (CV), biochemical (BV), and anthropometric variables (AV), at the beginning and at the end of the intervention.

RESULTS

Participants (n = 92) showed statistically significant differences (p < 0.05) at the end of the nutritional intervention in several CV, BV, and AV. However, two kinds of responses were observed after genotyping participants: (A) CR and WT showed statistically significant differences (p < 0.05) in several CV, BV, and AV for the SNPs 599C>T GPX1 (rs1050450), - 251A>G SOD1 (rs2070424), and - 262C>T CAT (rs1001179). (B) Only CR showed statistically changes (p < 0.05) in several CV, BV, and AV for the SNPs - 21A>T CAT (rs7943316) and 47C>T SOD2 (rs4880). The dietary intervention effect was statistically significantly between the polymorphisms of 47C>T SOD2 and BMI, SBP, TBARS, total cholesterol, and C-LCL (p < 0.05) and between the polymorphisms of - 21A>T CAT (rs7943316) and SBP, DBP, total cholesterol, and atherogenic index (p < 0.05).

CONCLUSION

People with obesity display different response in several CV, BV, and AV after a nutritional intervention, depending on the antioxidant genetic background of SOD and CAT enzymes.

A Study on Catalase Gene Promoter Polymorphism -21 A/T (rs7943316) in Healthy Pakistani population

Background & Objective

Catalase (CAT) is an important endogenous antioxidant enzyme that detoxifies H₂O₂ into water and oxygen, consequently limiting the deleterious effects of reactive oxygen species. It has suggested that CAT-21A/T (rs7943316) OMIM: 115500 gene promoter polymorphism is predominantly associated with different human disorders such as hypertension, cancers, diabetes, nephropathy, and other diseases accompanied by oxidative stress. This study was designed to investigate the prevalence of mutant T allele frequency in healthy individuals.

Methods

The study group consisted of 110 healthy individuals were enrolled from Baqai Institute of Diabetology and Endocrinology (BIDE), Karachi, Pakistan, during the period of April 2010 to May 2013. DNA was isolated from leukocytes. Genotyping of CAT-21A/T (rs7943316) gene promoter polymorphism was carried out using thermal cycler followed by RFLP. Blast N analysis was performed for the confirmation of gene sequences.

Results

In CAT-21A/T (rs7943316) gene promoter polymorphism, wild type genotype (AA) was observed in 18.26% and alterered genotype (AT/TT) found in 81.74% cases.

Conclusions

Data demonstrates that frequency and distribution of mutant T allele was more prevalent as compared to wild type A allele in the study group.

Influence of A-21T and C-262T genetic polymorphisms at the promoter region of the catalase (CAT) on gene expression

OBJECTIVE

Catalase (CAT, OMIM: 115500) is one of the major antioxidant enzymes, which plays an important role in the clearance of reactive oxygen species. Three genetic polymorphisms of A-21T (rs7943316), C-262T (rs1001179), and C-844T (rs769214) in the promoter region of the CAT have been reported. It has been suggested that these polymorphisms may alter the recognition sites of transcriptional factors, therefore it might be concluded that these polymorphisms may alter the expression levels of the gene. The aim of the present study is to evaluate the associations between these genetic variations and the CAT mRNA levels in human peripheral blood cells.

METHODS

The present study consisted of 47 healthy students of Shiraz University (south-west Iran). Genotypes of the CAT polymorphisms were determined by PCR based method. The quantitative CAT mRNA expression levels were investigated using quantitative real-time PCR.

RESULTS

Analysis of variance revealed significant differences between the study genotypes (For A-21T polymorphism: F = 7.45; df = 2, 44; P = 0.002; For C-262T polymorphism: F = 15.17; df = 2, 44; P < 0.001). The studied polymorphisms showed linkage disequilibrium (D' = 1.0, r 2 = 0.1813, χ 2 = 17.03, P < 0.0001). The mRNA levels of CAT in the AC/TT, TC/TC, TC/TT, and TC/TC diplotypes significantly were higher than the mRNA levels in AC/AC diplotype. There was a significant difference between the study genotypes (F = 9.24; df = 5, 41; P < 0.001). The TC/TC and TT/TT diplotypes showed about 2 and 4 folds CAT mRNA levels compared with the AC/AC diplotype.

CONCLUSIONS

The present findings indicated that these polymorphisms were significantly associated with the gene expression.