A haplotype of the catalase gene confers an increased risk of essential hypertension in Chinese Han
ABSTRACT Our previous study in an isolated population showed an association between a genetic variant in the catalase gene (CAT) and essential hypertension (EH). This study indicates that three variants in the promoter and 5'-UTR region of CAT are predominant in Chinese Han, and they form two major haplotypes. A case-control study showed that the CATH2 haplotype confers susceptibility to EH (Pgenotype=0.0017, and Pallilc=0.00078). Subjects bearing CATH1/CATH2 and CATH2/CATH2 genotypes demonstrated a higher susceptibility to EH than CATH1/CATH1 homozygotes, with odds ratios of 1.474 and 1.625, respectively. Also, CATH1/CATH1 individuals had a later-onset age (P=0.015). Expression analysis using luciferase reporter vectors indicated that the CATH1 haplotype showed a lower transcriptional activity than the haplotype CATH2 (P<0.05 in all four cell lines), and we observed similar results in the endogenous allelic expression ratios of CATH1/CATH2 in cell lines. In contrast, most CATH1 haplotypes showed a higher transcription level than CATH2 haplotypes (10 out of 11 or 90.9%) in blood from normal individuals (P<0.01). We therefore hypothesize that CATH1 and CATH2 may play alternating roles at different level of oxidative stress.
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ABSTRACT: BACKGROUND: Although many conventional factors have been associated with the development of arterial aging, cardiovascular diseases remain the first cause of death in old age. Therefore, identification of new risk factors may prove promising for monitoring this serious health problem. Oxidative stress and particularly catalase (CAT), an antioxidant enzyme, play an important role in endothelial cell pathophysiology, in shear stress response and ultimately in arterial aging. OBJECTIVE: Examine the relationships between CAT haplotypes and phenotypes of arterial aging (mean internal diameter, mean intima-media thickness of the common carotid arteries (CCA), presence of atheromatous plaques) in two French cohorts. METHODS AND RESULTS: 564 middle-aged French individuals (mean age 53 ± 12 years) from two cohorts (ERA and STANISLAS cohorts) were included in the study. Blood pressure, CCA intima-media thickness, CCA internal diameter and number of atheromatous plaques were measured. Catalase rs769214 SNP genotyping was performed. We identified a CAT haplotype that influences arterial aging. Individuals carrying the CAT2 haplotype had a higher mean internal diameter of CCA with aging and/or with an SBP ≥140 mmHg and were associated with a greater number of atheromatous plaques than CAT1 haplotypes carriers. This CAT2 haplotype appeared as an independent risk factor of arterial aging, similarly to previously identified factors such as age, systolic blood pressure, male, sex, tobacco use, hs-CRP, BMI and diabetes. CONCLUSION: The present study highlights the roles of CAT haplotypes in arterial aging and underlines the beneficial impact of the CAT1 haplotype on mean internal diameter of the CCA and atheromatous plaque number as well as on potential associated diseases.Atherosclerosis 01/2013; 227(1). DOI:10.1016/j.atherosclerosis.2012.12.015 · 3.97 Impact Factor
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ABSTRACT: Obesity is a multifactorial disease characterized by the excessive accumulation of fat in adipose tissue and peripheral organs. Its derived metabolic complications are mediated by the associated oxidative stress, inflammation and hypoxia. Oxidative stress is due to the excessive production of reactive oxygen species or diminished antioxidant defenses. Genetic variants, such as single nucleotide polymorphisms in antioxidant defense system genes, could alter the efficacy of these enzymes and, ultimately, the risk of obesity; thus, studies investigating the role of genetic variations in genes related to oxidative stress could be useful for better understanding the etiology of obesity and its metabolic complications. The lack of existing literature reviews in this field encouraged us to gather the findings from studies focusing on the impact of single nucleotide polymorphisms in antioxidant enzymes, oxidative stress-producing systems and transcription factor genes concerning their association with obesity risk and its phenotypes. In the future, the characterization of these single nucleotide polymorphisms (SNPs) in obese patients could contribute to the development of controlled antioxidant therapies potentially beneficial for the treatment of obesity-derived metabolic complications.International Journal of Molecular Sciences 02/2014; 15(2):3118-44. DOI:10.3390/ijms15023118 · 2.34 Impact Factor
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ABSTRACT: Catalase (CAT) is a peroxisomal antioxidant enzyme upregulated upon oxidative stress. Previous studies have found associations between some single nucleotide polymorphisms (SNPs) located in the CAT promoter region in a variety of metabolic diseases. This is the first study to analyze the association of erythrocyte CAT activity and candidate CAT SNPs with childhood obesity. The association study showed a significant positive association of the promoter variant -844A/G with childhood obesity and biomarkers of obesity such as weight, body mass index (BMI), BMI Z-Score and adipocyte fatty acid binding protein, along with a tendency towards significance with insulin resistance biomarkers. In addition CAT erythrocyte activity was found to be significantly lower in obese children and it was significantly correlated with obesity and insulin resistance biomarkers. No association was found between erythrocyte CAT activity and the SNP -844A/G. However, further in vitro and in vivo studies are needed to fully understand the role of CAT activity and SNPs in the development of insulin resistance in the setting of obesity. We hypothesize that CAT plays a role in early metabolic complications of obesity.Antioxidants & Redox Signaling 05/2013; DOI:10.1089/ars.2013.5386 · 7.67 Impact Factor