Glu298Asp polymorphism of the endothelial nitric oxide synthase gene in Turkish patients with ischemic stroke

Association of BglII Polymorphism in ITGA2 and (894G/T and -786T/C) Polymorphisms in eNOS Gene With Stroke Susceptibility in Tunisian Patients α2 Gene Polymorphism in α2β1 Integrin and eNOS Gene Variants and Stroke

BACKGROUND

This study investigated the association of BglII polymorphism in α2β1 integrin gene (ITGA2) and eNOS (894G/T and -786T/C) polymorphisms with ischemic stroke (IS) in Tunisian patients.

METHODS

The study comprised 210 patients with IS and 208 controls. The genotypes of the BglII polymorphism in ITGA2 and eNOS (894G/T and -786T/C) polymorphisms were determined using the PCR-RFLP. The χ² test was used and the genotype data comparison included heterozygous groups. Haplotype estimation and multiple logistic regression analysis were performed to analyze the significance of polymorphisms.

RESULTS

The genotype distribution of the BglII polymorphism was significantly different between cases and controls (p < 0.004). This polymorphism was associated with the risk of IS (OR = 3.38, p < 0.001) for the BglII(+/+) genotype. Likewise, the genotype distributions of eNOS (894G/T and -786T/C) polymorphisms were significantly different between the two groups (p < 0.005 and p < 0.01, respectively). The 894G/T polymorphism increased the risk of IS for the TT genotype (OR = 2.23, p < 0.008) and the GT genotype (OR = 1.74, p < 0.009). In addition, the -786T/C variant in the eNOS gene was a risk factor for IS for CC homozygous (OR = 2.52, p < 0.005). T-C Haplotype (OR = 3.06) from combination of the eNOS (894G/T and -786T/C) and T-C-BglII(+) haplotype (OR = 2.76) from combination of eNOS and ITGA2 polymorphisms represented high risks for IS.

CONCLUSIONS

This study suggests that the BglII variant in ITGA2 is associated with IS susceptibility. Furthermore, the 894G/T and -786T/C polymorphisms in the eNOS gene may be considered as genetic risk factors for IS in the Tunisian population.

Lipoprotein(a) Gene Polymorphism Increases a Risk Factor for Aortic Valve Calcification

Calcific aortic valve disease (CAVD) is a multifactorial condition. Both environmental and genetic factors play an important role in its etiology. CAVD exhibits a broad spectrum, varying from mild valve thickening to severe valve calcification and stenosis. Progression of the disease consists of chronic inflammation, lipoprotein deposition, and active leaflet calcification. It is a process similar to coronary artery disease. In this study, we investigated Lp(a) levels and gene polymorphisms associated with calcific aortic stenosis from blood samples after echocardiography in the evaluation of 75 patients diagnosed with CAVD and 77 controls. Blood tests were run in our laboratory to rule out certain risk factors before echocardiography examination. A significant association among smoking, elevated LDL level and creatinine, low albumin levels, Lp(a) level, rs10455872, and rs3798220 polymorphisms may be considered genetic risk factors for the development of calcific aortic stenosis.

Investigation of the relationship between ischemic stroke and endothelial nitric oxide synthase gene polymorphisms [G894T, intron 4 VNTR and T786C]

Background/aim

We aimed to investigate the associations between endothelial nitric oxide synthase (eNOS) gene polymorphisms [G894T (rs1799983)], intron 4 (27-bpTR) variable number tandem repeat (VNTR) and T786C (rs2070744), and ischemic stroke in the Anatolian population.

Materials and methods

This case-control study included 112 patients with “stroke of undetermined etiology” and 160 controls. Real-time polymerase chain reaction (RT-PCR) analysis was used to analyze these polymorphisms. Between-group frequencies of alleles and genotypes were compared using binary logistic regression analysis.

Results

No significant difference was observed between the two groups in terms of the genotype and allele distributions of the eNOS G894T (rs1799983) polymorphism (P > 0.05). The a alleles and the 4b/a and 4a/a genotypes of the intron 4 (27-bpTR) VNTR polymorphism had significantly higher frequencies in the patient group than in the control group (OR: 2.715, P < 0.001; OR: 3.396, P < 0.001; OR: 10.631, P = 0.016, respectively). On the contrary, the TC genotype and C alleles of the T786C (rs2070744) polymorphism had a significantly lower frequency in the patient group than in the control group (OR: 0.244, P < 0.001, OR: 0.605, P = 0.006, respectively).

Conclusion

Our findings indicate that the eNOS G894T and T786C [rs2070744] polymorphisms are not associated with the risk of ischemic stroke, whereas the intron 4 [27-bpTR] VNTR may be a risk factor in the Anatolian population.

The β-fibrinogen gene 455G/A polymorphism associated with cardioembolic stroke in atrial fibrillation with low CHA2DS2-VaSc score

Previous work has suggested that ischemic stroke (IS) may be more likely to occur in individuals with a genetic predisposition. In this study, we investigated the potential association of IS-relevant genetic risk factors with cardioembolic stroke (CES) in atrial fibrillation (AF) patients with low CHA2DS2-VaSc score. Genotyping was performed using the GenomeLab SNPstream genotyping platform for five IS-relevant SNPs (MMP-9 C1562T, ALOX5AP SG13S114A/T, MTHFR 677 C/T, FGB 455 G/A, and eNOS G298A) in 479 AF patients with CES and 580 age and sex-matched AF patients without CES. The multivariate analysis adjusted for potential confounders and demonstrated that FGB 455 G/A was independently associated with increased risk of CES in AF patients and the significance remained after Bonferroni correction in the additive, dominant, and recessive models with ORs of 1.548 (95% CI: 1.251–1.915, P = 0.001), 1.588 (95% CI: (1.226–2.057, P = 0.003), and 2.394 (95% CI: 1.357–4.223, P = 0.015), respectively. Plasma fibrinogen levels were significantly higher in patients with the A allele compared with patients with genotype of GG (3.29 ± 0.38 mg/dl vs. 2.87 ± 0.18 mg/dl, P < 0.001). We found for the first time that the A allele of FGB 455 G/A was a risk factor for CES in AF patients, probably by elevating the level of plasma fibrinogen.

GLU298ASP and 4G/5G Polymorphisms and the Risk of Ischemic Stroke in Young Individuals

BACKGROUND

Polymorphisms in the endothelial nitric oxide synthase (eNOS) and in the plasminogen activator inhibitor -1 (PAI-1) genes have been implicated in stroke pathogenesis but results are still controversial. The aim of this study was to examine the possible contribution of Glu298Asp in the eNOS and 4G/5G in the PAI-1polymorphisms with ischemic stroke in a young Mexican population.

MATERIALS AND METHODS

In a case-control study, conducted between January 2006 and June 2010, 204 patients ≤45 years of age with ischemic stroke and 204 controls matched by age and gender, were recruited. The Glu298Asp and 4G/5G polymorphisms were determined in all participants by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

There was a significant difference in the Glu298Asp genotype distribution (P=0.001) and allele frequency between the two groups (P=0.001). The 4G/5G genotype distribution (P=0.40) and the allele frequency was similar between groups; (P=0.13). There were independent factors for ischemic stroke: Asp carriage (GluAsp+AspAsp) (P=0.02); smoking (P=0.01); hypertension (P=0.03), and familial history of atherothrombotic disease (P=0.04).

CONCLUSIONS

The Asp allele from the Gu298Asp gene represents an independent risk factor for ischemic stroke in a young Mexican population. In contrast, the 4G/5G was not associated with an increased risk for this disease in the same group of patients, as previously has been demonstrated in other populations.

An Investigation of the Relationship between the eNOS Gene Polymorphism and Diagnosed Migraine

We investigated the phenotype-genotype association of the following endothelial nitric oxide synthase (eNOS) gene polymorphisms, rs743506, rs2070744, rs1799983, rs180079, rs3918226, rs207468799 and rs148554851, in patients suffering from migraine living in Edirne, Turkey. A total of 175 individuals, who had been diagnosed with migraine between April 2013 and December 2013, at the Neurology Department, Trakya University Medical Faculty, Edirne, Turkey, and 125 healthy controls were recruited. The above gene polymorphisms were analyzed from genomic DNA in both patient and control groups, using the pyro-sequencing method. The eNOS rs1799983 TT genotype frequency in migraine patients who had a headache duration of longer than 24 hours was statistically significantly higher than in patients who had migraine attacks that lasted under 24 hours (p = 0.047). In terms of the AGGTGGA haplotype, the severity of headache was statistically significant, and was found to be severe in 61.0% (p = 0.0001). Also in terms of the AGGTGGA haplotype, the duration of headache was statistically significant, and was >24 hours in 56.0% of patients (p = 0.008). In our study, there was no significant genotypephenotype relationship between eNOS rs743506, rs2070744, rs1799983, rs180079, rs3918226, rs207468799 and rs148554851 gene polymorphisms and migraine patients with and without aura living in Edirne, Turkey. The AGGTGGA haplotype constitutes a risk in terms of the severity and the duration of headaches in patients with migraine. This risk is significantly higher in patients with migraine with aura than patients with migraine without aura.

Genetic etiology of coronary artery disease considering NOS 3 gene variant rs1799983

Reduced production of nitric oxide due to rs1799983 single nucleotide polymorphism in nitric oxide synthase 3 gene (NOS3) may enhance the risk of coronary artery disease. The association of rs1799983 polymorphism with coronary artery disease was investigated in the local population of Pakistan. Study consisted of 376 individuals, out of which 198 were coronary artery disease patients and 178 were normal healthy individuals. Allele-specific polymerase chain reaction (PCR) based strategy was used for the detection of different genotypes of rs1799983 polymorphism. PCR amplification results were obtained for 354 samples. Frequency of T allele was higher as compared to G allele in our population. Strong association between rs1799983 and coronary artery disease was observed (p < 0.01). TT genotype was found to enhance 5.717 times the risk of coronary artery disease (odds ratio (OR): 5.717; 95% confidence interval (95% CI) 3.586-9.115). On the basis of present results, it can be concluded that rs1799983 is strongly associated with coronary artery disease in our population and TT genotype of this polymorphism enhanced the risk of coronary artery disease in Pakistani population.

Relationship between endothelial nitric oxide synthase gene polymorphisms and ischemic stroke: a meta-analysis

OBJECTIVES

Previous studies examining whether polymorphisms (G894T, 4b/a, and T786C) in the endothelial nitric oxide synthase (eNOS) gene are associated with ischemic stroke have yielded conflicting results. We performed a meta-analysis to investigate the potential association between these three eNOS gene polymorphisms and ischemic stroke risk.

MATERIALS AND METHODS

We searched databases until April 30, 2012 and used fixed or random effects models to estimate the pooled odds ratios (ORs).

RESULTS

We analyzed 34 case-control data sets from 33 publications involving 5261/5823 cases/controls for G894T, 4295/4682 for 4b/a, and 2698/3254 for T786C polymorphisms. For Asian populations, all models showed significantly increased risk of ischemic stroke for the G894T (dominant model: OR = 1.58; 95% CI, 1.30-1.91; P = 0.000) and 4b/a polymorphisms (dominant model: OR = 1.46; 95% CI, 1.25-1.71; P = 0.000), even after Bonferroni correction (because 0.000 < 0.017). In white populations, the aa genotype seemed to be protective for ischemic stroke, as indicated by the recessive model (OR = 0.44; 95% CI, 0.22-0.87; P = 0.019). In Asian populations, the T786C polymorphism was significantly associated with ischemic stroke, as found using the dominant (OR = 1.17; 95% CI, 1.02-1.34; P = 0.025) and additive models (OR = 1.18; 95% CI, 1.05-1.33; P = 0.006).

CONCLUSIONS

Our comprehensive meta-analysis ascertains that the G894T, 4b/a, and T786C polymorphisms are associated with ischemic stroke risk in Asians. A possible contrasting role of the 4b/a polymorphism in ischemic stroke was indicated in white populations.

An updated meta-analysis of endothelial nitric oxide synthase gene: three well-characterized polymorphisms with ischemic stroke

Polymorphisms in the endothelial nitric oxide synthase (eNOS) gene may influence the risk of ischemic stroke (IS), but the results are still debatable. A meta-analysis was performed to investigate the association between the eNOS gene polymorphisms in IS risk. Case-control studies on the association between the G894T, T-786C, and 4b/a polymorphisms and IS were searched up to July 2012, and the genotype frequencies in the control group were found to be consistent with the Hardy-Weinberg equilibrium (HWE). The effect summary odds ratio (OR) and 95% confidence intervals (CIs) were obtained. Meta-regression was used to explore the potential sources of heterogeneity. Funnel plots and Egger's test was used to estimate small study biases, and heterogeneity was assessed by chi-square-based Q-test and I(2) test. There were total 6537/6475 cases/controls for G894T, 3459/3951 cases/controls for 4b/a, and 2125/2673 cases/controls for T-786C polymorphism. For G894T and 4b/a, a significant association of 894T allele and 4a allele with increased risk of IS was found in Asians (TT+GT vs. GG: p<0.00001, OR=1.60, 95% CI=1.38-1.79, Pheterogeneity=0.11; aa+ba vs. bb: P<0.00001, OR=1.60, 95% CI=1.30-1.97, Pheterogeneity=0.02), but not in Caucasians (TT+GT vs. GG: P=0.60, OR=0.94, 95% CI=0.75-1.19, Pheterogeneity=0.002; aa+ba vs. bb: P=0.13, OR=0.81, 95% CI=0.62-1.06, Pheterogeneity=0.63). For T-786C polymorphism, there were no significant differences in genotype distribution between IS and control in Asians (CC+TC vs. TT: P=0.15, OR=1.14, 95% CI=0.95-1.37, Pheterogeneity=0.94) and in Caucasians (CC+TC vs. TT: P=0.72, OR=0.96, 95% CI=0.75-1.22, Pheterogeneity=0.53). This analysis provides strong evidence that the eNOS T-786C gene polymorphism is not associated with IS, the G894T and 4b/a polymorphisms might be associated with IS, at least in Asians.

Endothelial NO synthase gene polymorphisms and risk of ischemic stroke in Asian population: a meta-analysis

Background

The association between polymorphism 4b/a, T-786C and G894T in endothelial NO synthase gene (eNOS) and ischemic stroke (IS) remains controversial in Asian. A meta-analysis was performed to better clarify the association between eNOS gene and IS risk.

Methods

Based on the search of PubMed, Web of Science (ISI), CNKI (National Knowledge Infrastructure), Wan Fang Med Online and CBM (Chinese Biology Medical Literature Database) databases, all eligible case-control or cohort studies were identified. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) from fixed and random effect models were calculated. Heterogeneity among studies was evaluated using the I². Meta-regression was used to explore the potential sources of between-study heterogeneity. Begg's test was used to estimate publication bias.

Results

Our study included 27 articles, contained 28 independent case–control studies, involved a total of 3,742 cases and 3,691 controls about 4b/a, 1,800 cases and 1,751 controls about T-786C and 2,747 cases and 2,872 controls about G894T. A significant association of 4a allele with increased risk of IS was found in dominant (FEM: OR = 1.498, 95% CI = 1.329–1.689), recessive (FEM: OR = 2.132, 95% CI = 1.383–3.286) and codominant (REM: OR = 1.456, 95% CI = 1.235–1.716) models. For T-786C and G894T, there were significant associations with dominant and codominant genetic models, but not with recessive genetic model.

Conclusions

The meta-analysis indicated that eNOS gene 4b/a, T-786C, G894T polymorphism might be associated with IS.

Association of G894T polymorphism in endothelial nitric oxide synthase gene with the risk of ischemic stroke: A meta-analysis

Findings of a previous meta-analysis demonstrated no association between G894T polymorphism in endothelial nitric oxide synthase (eNOS) gene and ischemic stroke. Results of other studies have also been inconsistent. Updated meta-analysis was performed to assess the association between the eNOS gene G894T (rs1799983) polymorphism and the risk of ischemic stroke. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) from fixed and random effects models were calculated. Heterogeneity in the studies was evaluated using the I². Meta-regression and the 'leave-one-out' sensitive analysis were used to examine the potential sources of between-study heterogeneity. Publication bias was estimated using the Egger's test. Data were available for 6,607 cases and 6,947 controls from 22 studies. Studies deviating from the Hardy-Weinberg equilibrium (HWE) in the controls and the key contributors to between-study heterogeneity were excluded. Significant associations between eNOS gene G894T polymorphism and the risk of ischemic stroke were observed in the dominant (OR 1.249; 95% CI, 1.145-1.361), the recessive (OR 1.255; 95% CI, 1.082-1.456) and the codominant models (OR 1.195; 95% CI, 1.115-1.281). Moreover, in the subgroup analysis based on the region (Asia and Europe), significant associations were observed between the dominant and codominant genetic models but not in the recessive model. The results of our meta-analysis suggested that eNOS gene G894T polymorphism was associated with the increased risk of ischemic stroke, and that the T allele may be an important risk factor for ischemic stroke. However, further studies are required to confirm this result.

Association of the 894G>T polymorphism in the endothelial nitric oxide synthase gene with risk of venous thromboembolism in Chinese population

INTRODUCTION

Endothelium derived nitric oxide (NO) is a key mediator of vascular homeostasis. Endothelial nitric oxide synthase (eNOS) gene, by affecting the expression and functional activity of the eNOS enzyme, thereby reducing NO availability, may be implicated in venous thromboembolism (VTE). We investigated the eNOS G894T polymorphism in VTE patients in the Chinese population.

MATERIALS AND METHODS

A case-control study was conducted in a general hospital. Blood samples, collected from 462 consecutive patients with VTE and 462 healthy controls, were used for DNA extraction. Single nucleotide polymorphisms (SNP) of eNOS (894G/T) were determined by allele specific-polymerase chain reaction (ARMS-PCR) analysis.

RESULTS

The eNOS 894G/T polymorphism alleles distribution was in agreement with the principle of Hardy-Weinberg equilibrium. The prevalence of homozygote, heterozygote and pathological homozygote for the eNOS G894T polymorphism in VTE patients was 79.7%, 18.1% and 2.2%, respectively (controls: 86.6%，12.3% and 1.1%). T allele distribution in the VTE (11.3%) and especially the male VTE patients (12.5%) was more common than in healthy controls (7.3%). The frequency of GT+TT genotype was significantly higher among the age≤55years patients in VTE group than in controls (20.1% vs. 12.2%, P=0.033).

CONCLUSION

Our result demonstrates that the 894G/T polymorphism variant of eNOS is a risk factor for VTE in Chinese population.

Determination of the effects of eNOS gene polymorphisms (T-786C and Glu298Asp) on nitric oxide levels in a methylmercury-exposed population

Nitric oxide (NO) is a potent vasodilator with multiple protective effects involved in the regulation of cardiovascular functions. Endothelial NO synthase (eNOS) gene polymorphisms and environmental factors, such as mercury (Hg) exposure, may influence NO levels and increase the risk of cardiovascular damage. The aim of this study was to determine the role of the T-786C and Glu298Asp polymorphisms of the eNOS gene on nitrite concentrations following Hg exposure in humans. It was postulated that Hg exposure might decrease circulating nitrite concentrations and that variants in the eNOS gene might enhance the adverse effects of Hg resulting in increased risk of cardiovascular disease. Blood samples were collected from 202 volunteers exposed to methylmercury (MeHg) following fish consumption. Blood Hg concentrations (BHg) were determined by inductively coupled plasma-mass spectrometry and nitrite plasma concentration by a chemiluminescent method. The mean Hg concentration was 50.5 ± 35.4 μg/L and mean nitrite concentration was 251.4 ± 106.3 nM. There were no significant differences in age, arterial blood pressure, body mass index, heart rate, and concentrations of Hg and nitrite concentrations between the genotype groups . When data were grouped together (TC + CC and TT group), there were still no marked differences. A multiple regression model indicated that decreased NO production was predominantly due to Hg, age, and gender. Polymorphisms did not seem to influence this effect. Our findings suggest that eNOS gene polymorphisms (T-786C and Glu298Asp) are not associated with an increased risk for cardiovascular diseases in MeHg-exposed subjects.

Endothelial nitric oxide synthase Glu298Asp, 4b/a, and -786T>C gene polymorphisms and the risk of ischemic stroke

BACKGROUND AND PURPOSE

Endothelial nitric oxide synthase (eNOS) gene polymorphisms were associated with reduced NO production, and were evaluated as risk factors for ischemic stroke (IS). We investigated the association between eNOS gene -786T>C (promoter), 27-bp repeat 4b/4a (intron 4), and Glu298Asp (exon 7) polymorphisms with IS in 329 IS patients and 444 controls.

MATERIALS AND METHODS

Glu298Asp and -786T>C genotyping was done by PCR-RFLP, 4b/4a was assessed by PCR-ASA. The contribution of eNOS polymorphisms to IS was analyzed by haplotype and multivariate regression analysis.

RESULTS

Higher frequency of 298Asp allele was seen in IS patients (P = 1.2 x 10(-10)), which remained independently associated with IS on multivariate analysis after controlling for traditional cerebrovascular risk factors. Allele and genotype distribution of 4b/4a and -786T>C polymorphisms were comparable between patient and controls. Significantly higher prevalence of 298Asp/4b/-786T and 298Asp/4b/-786C haplotypes were seen in IS cases, thus conferring a disease susceptibility nature to these haplotypes. Multivariate regression analysis confirmed the association of 298Asp/4b/-786T and 298Asp/4b/-786C haplotypes, and in addition identified 298Asp/4a/-786T haplotype to be independently associated with IS, after controlling for traditional cerebrovascular risk factors.

CONCLUSIONS

Genetic variation at the eNOS locus represent genetic risk factor for increased susceptibility to IS.