A comprehensive contribution of genes for aryl hydrocarbon receptor signaling pathway to hypertension susceptibility.

OBJECTIVE: The present study was designed to investigate whether genetic polymorphisms of the aryl hydrocarbon receptor (AHR) signaling pathway are involved in the molecular basis of essential hypertension (EH). METHODS: A total of 2160 unrelated Russian individuals comprising 1341 EH patients and 819 healthy controls were recruited into the study. Seven common AHR pathway single-nucleotide polymorphisms (SNPs) such as rs2066853, rs2292596, rs2228099, rs1048943, rs762551, rs1056836, and rs1800566 were genotyped by TaqMan-based allele discrimination assays. RESULTS: We found that SNP rs2228099 of ARNT is associated with an increased risk of EH (odds ratio=1.20 95% confidence interval: 1.01-1.44, P=0.043) in a dominant genetic model, whereas polymorphism rs762551 of CYP1A2 showed an association with a decreased risk of disease in a recessive genetic model (odds ratio=0.68, 95% confidence interval: 0.52-0.89, P=0.006). A log-likelihood ratio test enabled identification of epistatic interaction effects on EH susceptibility for all SNPs. MB-MDR analysis showed that cigarette smoking, rs1048943, rs762551, rs1056836, and rs2228099 were significant contributing factors in 19, 18, 13, 13, and 11 interaction models, respectively. The best MDR model associated with EH risk included rs1048943, rs762551, rs1056836, and cigarette smoking (cross-validation consistency 100%, prediction error 45.7%, Ppermutation<0.0001). The mRNA expression and in-silico function prediction analyses have confirmed a regulatory potential for a majority of SNPs associated with EH susceptibility. CONCLUSION: Our pilot study was the first to show that gene-gene and gene-environment interactions in the AHR signaling pathway represent important determinants for the development of EH, and the pathway may become an attractive target for a pharmacological intervention in hypertensive patients in the future.

Genetic variation of genes for xenobiotic-metabolizing enzymes and risk of bronchial asthma: the importance of gene-gene and gene-environment interactions for disease susceptibility.

The aim of our pilot study was to evaluate the contribution of genes for xenobiotic-metabolizing enzymes (XMEs) for the development of bronchial asthma. We have genotyped 25 polymorphic variants of 18 key XME genes in 429 Russians, including 215 asthmatics and 214 healthy controls by a polymerase chain reaction, followed by restriction fragment length polymorphism analyses. We found for the first time significant associations of CYP1B1 V432L (P=0.045), PON1 Q192R (P=0.039) and UGT1A6 T181A (P=0.025) gene polymorphisms with asthma susceptibility. Significant P-values were evaluated through Monte-Carlo simulations. The multifactor-dimensionality reduction method has obtained the best three-locus model for gene-gene interactions between three loci, EPHX1 Y113H, CYP1B1 V432L and CYP2D6 G1934A, in asthma at a maximum cross-validation consistency of 100% (P=0.05) and a minimum prediction error of 37.8%. We revealed statistically significant gene-environment interactions (XME genotypes-smoking interactions) responsible for asthma susceptibility for seven XME genes. A specific pattern of gametic correlations between alleles of XME genes was found in asthmatics in comparison with healthy individuals. The study results point to the potential relevance of toxicogenomic mechanisms of bronchial asthma in the modern world, and may thereby provide a novel direction in the genetic research of the respiratory disease in the future.

A common polymorphism G-50T in cytochrome P450 2J2 gene is associated with increased risk of essential hypertension in a Russian population.

The present study was designed to test whether common polymorphism G-50T within the promoter of human CYP2J2 gene is associated with increased risk of essential hypertension in a Russian population. We studied 576 unrelated subjects, including 295 patients with hypertension and 281 healthy subjects. Genotyping for polymorphism G-50T of the CYP2J2 gene was performed by polymerase chain reaction and restriction fragment length polymorphism techniques. The frequency of a -50T variant allele of CYP2J2 gene was significantly higher in patients with hypertension versus healthy controls (OR 4.03 95%CI 1.80-9.04 p=0.0004). The association of a -50GT genotype with hypertension remained significant after adjustment for age, gender and family history of hypertension by multivariate logistic regression (OR 4.78 95%CI 1.87-12.27 p=0.001). It has been found that OR for -50GT genotype x gender interaction (OR 4.48 95%CI 1.93-10.39 p=0.00048) was slightly higher than OR for -50GT genotype (OR 4.43 95%CI 1.91-10.29 p=0.00052), suggesting a weak effect of gender on the risk of hypertension in the heterozygous carriers of -50GT genotype. A family history of hypertension has no effect on the association between a -50GT genotype and hypertension. In present study we demonstrate for the first time that a CYP2J2*7 allele of the CYP2J2 gene is clearly associated with an increased risk of essential hypertension. Furthermore, this study highlights the importance of P-450 epoxygenase pathway of arachidonic acid metabolism in the pathogenesis of hypertensive disease.

Promoter polymorphism G-50T of a human CYP2J2 epoxygenase gene is associated with common susceptibility to asthma.

BACKGROUND: Cytochrome P-450 2J2 (CYP2J2) has recently been shown to be an important enzyme in the metabolism of epoxygenase-derived eicosanoids that play important functional roles in pulmonary physiology and may contribute to the pathogenesis of asthma. STUDY OBJECTIVE: The focus of our pilot study was to evaluate whether common polymorphism G-50T within the proximal promoter of human CYP2J2 gene is associated with the susceptibility to bronchial asthma. DESIGN AND PARTICIPANTS: A total of 429 unrelated Russian subjects were recruited in this case-control study, including 215 sex-matched and age-matched patients with asthma and 214 healthy control subjects. The blood samples were analyzed for genetic polymorphism G-50T in the CYP2J2 gene by polymerase chain reaction followed by restriction fragment length polymorphism analysis. RESULTS: The frequency of variant allele -50T of the CYP2J2 gene was significantly higher in asthmatic patients than in healthy subjects (odds ratio [OR], 5.04; 95% confidence interval [CI], 1.99 to 12.77; p = 0.0003). In addition, the heterozygous genotype -50GT of the CYP2J2 gene was found to be significantly associated with susceptibility to allergic asthma (OR, 5.40; 95% CI, 2.05 to 14.26; p = 0.0003) as well as nonallergic asthma (OR, 5.77; 95% CI, 1.84 to 18.10; p = 0.004). The associations of the CYP2J2 gene G-50T polymorphism with asthma remained significant after adjustment for age and gender using multiple logistic regression analysis. CONCLUSIONS: Our data demonstrate for the first time that the CYP2J2 gene might be considered as a novel candidate gene for common susceptibility to asthma and highlight the importance of the P-450 epoxygenase pathway of metabolism of arachidonic acid in the pathogenesis of the disease.

Alcohol Consumption and Cigarette Smoking are Important Modifiers of the Association Between Acute Pancreatitis and the PRSS1-PRSS2 Locus in Men.

OBJECTIVES: The present study was designed to investigate whether the susceptibility to acute pancreatitis (AP) attributable to polymorphism rs10273639 at the PRSS1-PRSS2 locus is dependent on alcohol consumption and cigarette smoking. METHODS: A total of 603 unrelated Russian individuals including 304 patients with physician-diagnosed AP and 299 sex- and age-matched healthy controls have been recruited for the study. A polymorphism rs10273639 (-408C>T) of PRSS1-PRSS2 was genotyped by TaqMan-based assay. RESULTS: A variant allele -408T (P = 0.003) and genotypes -408CT plus TT (P = 0.002) were associated with decreased AP risk only in men. The odds ratios for AP in the CC homozygotes versus the variant genotypes were 1.95 [95% confidence interval (CI), 0.65-5.85; P = 0.23], 1.72 (95% CI, 0.93-3.20; P = 0.08), and 2.37 (95% CI, 1.09-5.13; P = 0.03) for men who consumed up to 28, 29 to 59, and more than 60 alcohol drinks a week, respectively. Cigarette smokers with the -408CC genotype had an increased risk of AP (odds ratio, 2.07; 95% CI, 1.25-3.42; P = 0.004), whereas nonsmoker carriers did not have a disease risk (odds ratio, 1.48; 95% CI, 0.58-3.82; P = 0.42). CONCLUSIONS: We confirmed a robust association of polymorphism rs10273639 at PRSS1-PRSS2 with AP in the Russian population. The present study is the first to show that relationship between the locus and disease is significantly modified by alcohol consumption and cigarette smoking.

Altered erythrocyte membrane protein composition mirrors pleiotropic effects of hypertension susceptibility genes and disease pathogenesis.

OBJECTIVE: The study was designed to assess the effects of polymorphisms in genes associated with essential hypertension on the variation of erythrocyte membrane proteins (EMPs) in hypertensive patients. METHODS: Major EMPs content was analyzed in blood from 1162 unrelated Russians (235 hypertensive patients, 176 healthy controls, and 751 random individuals from the Central Russia population). Essential hypertension patients were genotyped for 11 polymorphisms of essential hypertension susceptibility genes including ADD1 (rs4961), GNB3 (rs5443, rs16932941), NOS3 (rs1799983, rs2070744), ACE (rs5186), AGTR1 (rs5186), AGT (rs699, rs4762), MR (rs5534), and TGFB1 (rs1800471). EMP contents and their relationship with the genetic loci were analyzed using various statistical tests. RESULTS: Sex-specific differences in EMP contents between the cases and controls were observed. Regardless of sex, hypertensives exhibited mainly decreased levels of alpha (SPTA1) and beta-spectrin (SPTB) and increased levels of glucose transporter (GLUT1) as compared with healthy subjects (P ≤ 0.001). EMP correlated differently in essential hypertension patients and controls. Almost 70% of the joint variation in the EMP levels is explained by five gender-specific principal components. The essential hypertension susceptibility genes showed considerable effects on the levels of spectrins and glucose transporter. A joint variation of the genes explained about half the total polygenic variance in the GLUT1, SPTA1, and SPTB levels in hypertensives. CONCLUSIONS: The study showed that essential hypertension susceptibility genes are the important factors of the inherited EMP variation, and their pleitropic effects may be mirrored in the altered expression of genes encoding cytoskeletal proteins and those related to intracellular glucose metabolism.

Antioxidant defense enzyme genes and asthma susceptibility: gender-specific effects and heterogeneity in gene-gene interactions between pathogenetic variants of the disease.

Oxidative stress resulting from an increased amount of reactive oxygen species and an imbalance between oxidants and antioxidants plays an important role in the pathogenesis of asthma. The present study tested the hypothesis that genetic susceptibility to allergic and nonallergic variants of asthma is determined by complex interactions between genes encoding antioxidant defense enzymes (ADE). We carried out a comprehensive analysis of the associations between adult asthma and 46 single nucleotide polymorphisms of 34 ADE genes and 12 other candidate genes of asthma in Russian population using set association analysis and multifactor dimensionality reduction approaches. We found for the first time epistatic interactions between ADE genes underlying asthma susceptibility and the genetic heterogeneity between allergic and nonallergic variants of the disease. We identified GSR (glutathione reductase) and PON2 (paraoxonase 2) as novel candidate genes for asthma susceptibility. We observed gender-specific effects of ADE genes on the risk of asthma. The results of the study demonstrate complexity and diversity of interactions between genes involved in oxidative stress underlying susceptibility to allergic and nonallergic asthma.

Analysis of common transforming growth factor beta-1 gene polymorphisms in gastric and duodenal ulcer disease: pilot study.

BACKGROUND AND AIM: Transforming growth factor-beta1 (TGF-beta1) has been shown to be an important cytokine that plays a role in cell proliferation, differentiation, tissue injury repair and ulcer healing. The purpose of this pilot study was to investigate if common polymorphisms Leu10Pro, Arg25Pro and C-509T within the TGF-beta1 gene are associated with susceptibility to gastric and duodenal ulcer disease in Russians. METHOD: Blood samples from 377 unrelated patients with gastric and duodenal ulcer disease and 226 sex- and age-matched healthy controls were used to determine TGF-beta1 gene polymorphisms by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Leu10Pro substitution in the signal peptide of TGF-beta1 has been found to be associated with susceptibility to gastric ulcer (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.12-2.77). A genotype combination of 10Leu/Leu x 25Arg/Arg x -509C/C was also associated with susceptibility to gastric ulcer disease (OR 1.81, P = 0.01). In addition, the frequency of a combination of genotypes 10Pro/Pro x 25Arg/Pro x -509C/T was statistically lower in patients with duodenal ulcer than in controls (OR 0.42, P = 0.05). A significant difference (P = 0.04) in the distribution of rare haplotypes of the TGF-beta1 gene between patients with duodenal ulcer and healthy controls has been found. Polymorphism Leu10Pro was in positive linkage disequilibrium with C-509T polymorphism (coefficient D = 0.191; P < 0.0001). CONCLUSIONS: These findings indicate that the Leu10Pro and C-509T polymorphisms may be involved in the modulation of expression of the TGF-beta1 gene, and therefore a predisposition to peptic ulcer disease could be linked to particular alleles of this gene. In particular, a possible role of TGF-beta1 in the pathogenesis of gastric ulcer disease is discussed.