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

Endothelial Nitric Oxide Synthase (Glu298Asp) Polymorphism is Associated Significantly with Ischemic Stroke Presenting with Seizures and Altered Sensorium

Background

Endothelial nitric oxide synthase (eNOS) is an enzymatic marker whose genetic polymorphism might predispose to acute ischemic stroke (AIS) via vascular endothelial dysfunction. It has a potential role in atherosclerosis, making it a plausible risk factor for stroke. Prior studies have failed to prove a conclusive relationship between eNOS polymorphism and AIS.

Objective

The aim of this study is to find an association between the presence of eNOS polymorphism (Glu298Asp) and the risk of developing AIS.

Materials and Methods

We recruited 307 subjects including 153 AIS cases and 154 healthy controls. The eNOS (Glu298Asp) polymorphism was identified in EDTA blood by PCR amplification of the target region followed by restriction enzyme digestion, and genotyping on Agarose gel. GG, GT and TT genotypes were obtained. Statistical analysis was done using SPSS software version 20.

Results

A significant association was found between the presence of TT genotype and the risk of AIS (Odd's ratio (OR): 2.43, P-value = 0.038). There was no significant association between the TT genotype and the traditional stroke risk factors. However, the TT genotype was significantly associated with the presence of altered consciousness (OR: 5.27, 95% CI: 1.59-17.04, P-value = 0.003) and with the occurrence of seizures at presentation (OR: 7.98, 95% CI: 1.99-32.09, P-value = 0.007).

Conclusions

There is a significant association between the presence of eNOSpolymorphism (Glu298Asp) and the risk of AIS, and the TT genotype may predispose to a more severe initial presentation of ischemic stroke.

NF-κB Inhibitors Attenuate MCAO Induced Neurodegeneration and Oxidative Stress-A Reprofiling Approach

Stroke is the leading cause of morbidity and mortality worldwide. About 87% of stroke cases are ischemic, which disrupt the physiological activity of the brain, thus leading to a series of complex pathophysiological events. Despite decades of research on neuroprotectants to probe for suitable therapies against ischemic stroke, no successful results have been obtained, and new alternative approaches are urgently required in order to combat this pathological torment. To address these problems, drug repositioning/reprofiling is explored extensively. Drug repurposing aims to identify new uses for already established drugs, and this makes it an attractive commercial strategy. Nuclear factor-kappa beta (NF-κB) is reported to be involved in many physiological and pathological conditions, such as neurodegeneration, neuroinflammation, and ischemia/reperfusion (I/R) injury. In this study, we examined the neuroprotective effects of atorvastatin, cephalexin, and mycophenolate against the NF-κB in ischemic stroke, as compared to the standard NF-κB inhibitor caeffic acid phenethyl ester (CAPE). An in-silico docking analysis was performed and their potential neuroprotective activities in the in vivo transient middle cerebral artery occlusion (t-MCAO) rat model was examined. The percent (%) infarct area and 28-point composite neuro score were examined, and an immunohistochemical analysis (IHC) and enzyme-linked immunosorbent assay (ELISA) were further performed to validate the neuroprotective role of these compounds in stroke as well as their potential as antioxidants. Our results demonstrated that these novels NF-κB inhibitors could attenuate ischemic stroke-induced neuronal toxicity by targeting NF-κB, a potential therapeutic approach in ischemic stroke.

A Review of Exercise as Medicine in Cardiovascular Disease: Pathology and Mechanism

Background

Physical inactivity and resultant lower energy expenditure contribute unequivocally to cardiovascular diseases, such as coronary artery disease and stroke, which are considered major causes of disability and mortality worldwide.

Aim

The aim of the study was to investigate the influence of physical activity (PA) and exercise on different aspects of health - genetics, endothelium function, blood pressure, lipid concentrations, glucose intolerance, thrombosis, and self - satisfaction. Materials and.

Methods

In this article, we conducted a narrative review of the influence PA and exercise have on the cardiovascular system, risk factors of cardiovascular diseases, searching the online databases; Web of Science, PubMed and Google Scholar, and, subsequently, discuss possible mechanisms of this action.

Results and Discussion

Based on our narrative review of literature, discussed the effects of PA on telomere length, nitric oxide synthesis, thrombosis risk, blood pressure, serum glucose, cholesterol and triglycerides levels, and indicated possible mechanisms by which physical training may lead to improvement in chronic cardiovascular diseases.

Conclusion

PA is effective for the improvement of exercise tolerance, lipid concentrations, blood pressure, it may also reduce the serum glucose level and risk of thrombosis, thus should be advocated concomitant to, or in some cases instead of, traditional drug-therapy.

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 Methylenetetrahydrofolate Reductase C677T (rs1801133) and Apolipoprotein A5-1131T>C (rs662799) Polymorphisms, and Anemia Are Independent Risk Factors for Ischemic Stroke

BACKGROUND

Although there is adequate knowledge as to the role of traditional cardiovascular risk factors on stroke incidence, knowledge of other risk factors, particularly genetic ones, is still incomplete.

METHODS

To assess the participation of some polymorphisms, along with other modifiable risk factors, a case-control study was conducted. A total of 253 cases were identified in the emergency room of a general regional hospital, with a clinical trait of stroke confirmed by a skull computerized axial tomography scan. In the surgery ward, 253 controls were identified, gender and age (±5 years) matched. Biochemical parameters were measured, and 4 polymorphisms were genotyped by polymerase chain reaction, rs1801133 (methylenetetrahydrofolate reductase [MTHFR]), rs1498373 (dimethylarginine dimethylaminohydrolase type 1 [DDAH1]), rs662799 (apolipoprotein A5 [APOA5]), and rs1799983 (endothelial nitric oxide). Odds ratios were estimated to assess the strength of association, with 95% confidence intervals, both in a matched case-control analysis and in a conditional regression analysis.

RESULTS

Cases had higher mean blood pressure and triglycerides and lower hemoglobin levels. Heterozygous and homozygous subjects to the rs1801133 variant of the MTHFR gene had a 3-fold higher risk of stroke. In the dominant model, those with the polymorphism rs662799 of the promoter region for APOA5 had twice the risk of stroke. Anemia increased the risk of stroke 4-fold.

CONCLUSIONS

Polymorphisms of the genes MTHFR (rs1801133) and APOA5 (rs662799), as well as anemia, are independent risk factors for stroke in Mexicans, together with traditional cardiovascular risk factors such as high triglycerides and high blood pressure.

Polymorphisms of MTHFR, eNOS, ACE, AGT, ApoE, PON1, PDE4D, and Ischemic Stroke: Meta-Analysis

INTRODUCTION

The association between ischemic stroke and genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR; 677C>T and 1298A>C), endothelial nitric oxide synthase (eNOS; -786T>C, +894G>T, and variable number tandem repeat [VNTR]), phosphodiesterase 4D (PDE4D; SNPs 83 and 87), angiotensin-converting enzyme (ACE) I/D, angiotensinogen (AGT) 235M>T, paraoxonase 1 (PON1) 192Q>R, and apolipoprotein E (ApoE) ε2ε3ε4 remains inconclusive. Therefore, this updated meta-analysis aimed to clarify the presumed influence of genetic polymorphisms on ischemic stroke by meta-analyzing the comprehensive coverage of all individual association studies.

METHODS

All case-control studies published in different languages such as English, Japanese, Korean, Spanish, Chinese, Hungarian, Ukrainian, or Russian were identified from databases. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated via fixed- and random-effect models. Sensitivity analysis, heterogeneity test, Hardy Weinberg Equilibrium, and Egger's regression analyses were performed in this study.

RESULTS

A total of 490 case-control studies with 138,592 cases and 159,314 controls were included in this meta-analysis. Pooled ORs from all the genetic models indicated that MTHFR 677TT and 1298CC, eNOS +894TT and VNTR, PDE4D SNP 83, ACE DD, AGT 235TT, PON1 192RR, and ApoE ε4 polymorphisms were increasing the risks of ischemic stroke. Nevertheless, PDE4D SNP 87 and eNOS -786T>C polymorphisms are not associated with ischemic stroke risks.

CONCLUSIONS

Hence, the evidence from this meta-analysis concluded that MTHFR (677C>T and 1298A>C), eNOS (+894G>T and VNTR), PDE4D SNP 83, ACE I/D, AGT 235M>T, PON1 192Q>R, and ApoE ε2ε3ε4 polymorphisms predispose individuals to ischemic stroke.

Association of eNOS and Cav-1 gene polymorphisms with susceptibility risk of large artery atherosclerotic stroke

Endothelial nitric oxide synthase (eNOS) is localized in caveole and has important effects on caveolar coordination through its interaction with caveolin-1 (Cav-1), which supports normal functioning of vascular endothelial cells. However, the relationship between genotypic polymorphisms of e-NOS and Cav-1 genes and ischemic stroke (IS) remains lesser reported. This hospital-based case-control study aimed to determine the genetic polymorphisms of the eNOS (Glu298Asp) and Cav-1 (G14713A and T29107A) genes in association with susceptibility risk in patients who had suffered from a large artery atherosclerotic (LAA) stroke. Genotyping determination for these variant alleles was performed using the TaqMan assay. The distributions of observed allelic and genotypic frequencies for the polymorphisms were in Hardy-Weinberg equilibrium in healthy controls. The risk for an LAA stroke in the Asp298 variant was 1.72 (95% CI = 1.09–2.75) versus Glu298 of the eNOS. In the GA/AA (rs3807987) variant, it was 1.79 (95% CI = 1.16–2.74) versus GG and in TA/AA (rs7804372) was 1.61 (95% CI = 1.06–2.43) versus TT of the Cav-1, respectively. A tendency toward an increased LAA stroke risk was significant in carriers with the eNOS Glu298Asp variant in conjunction with the G14713 A and T29107A polymorphisms of the Cav-1 (aOR = 2.03, P-_trend = 0.002). A synergistic effect between eNOS and Cav-1 polymorphisms on IS risk elevation was significantly influenced by alcohol drinking, heavy cigarette smoking (P-_trend<0.01), and hypercholesterolemia (P-_trend < 0.001). In conclusion, genotypic polymorphisms of the eNOS Glu298Asp and Cav-1 14713A/29107A polymorphisms are associated with the elevated risk of LAA stroke among Han Chinese in Taiwan.

Vascular Genetic Variants and Ischemic Stroke Susceptibility in Albanians from the Republic of Macedonia

BACKGROUND

Acute first-ever ischemic stroke (FIS) is a heterogeneous, polygenic disorder. The contribution of vascular genetic variants as inherited causes of ischemic stroke has remained controversial.

AIM

To examine the association of genetic variants in vascular factors with the occurrence of FIS.

MATERIAL AND METHODS

The current research was performed in a group of 39 patients with FIS (study group) and 102 healthy volunteers (control group). We analyzed the prevalence of vascular genetic variants in following genes: factor V, prothrombin, methylenetetrahydrofolate reductase (MTHFR), factor XIII, plasminogen activator 1, endothelial protein C receptor (EPCR), apolipoprotein B, apolipoprotein E, β-fibrinogen, human platelet antigen 1, angiotensin-converting enzyme (ACE), endothelial nitric oxide synthase (eNOS) and lymphotoxin alpha.

RESULTS

It was found that heterozygous LTA 804C>A and FXIII V34L Leu/Leu were significantly more frequent in patients with FIS than in control group (p = 0.036 and p = 0.017, respectively). The frequency of FXIII V34L Val/Val was significantly lower in patients with FIS than in control group (p = 0.020). Other frequencies of vascular gene variants in patients with FIS and in control group were not significantly different.

CONCLUSIONS

This is the first comprehensive study to present data indicating that polymorphism of vascular genes in the prevalence of acute FIS exists in the Albanian population from the Republic of Macedonia. Variations in these genes have been detected in patients with acute FIS, suggesting that their combination might act in a susceptible or protective manner in this Albanian population.

Risk Factors for Normal and High-Tension Glaucoma in Poland in Connection with Polymorphisms of the Endothelial Nitric Oxide Synthase Gene

Aim

The purpose of this study was to evaluate the influence of polymorphisms of the eNOS gene on the clinical status of patients with normal and high tension glaucoma.

Methods

266 Polish Caucasian patients with primary open angle glaucoma were studied. Of the 266, 156 had normal tension glaucoma (NTG) and 110 high tension glaucoma (HTG). DNA material was isolated from peripheral venous blood using commercial kits. Real-time PCR reaction was used to amplify the promoter site of the endothelial nitric oxide synthase (eNOS) gene, including the single nucleotide polymorphism (SNP) site T-786C and part of the 7^th exon of eNOS, including G894T SNP. Genotypes were determined with TaqMan SNP Genotyping Assays.

Results

There were no significant differences in frequencies of the allelic variants of both polymorphisms. In G894T SNP, however, the wild GG form was more common in the HTG group. The SNP of the eNOS gene did not significantly influence the progression rate in either of the groups studied. There were no differences in variants of the eNOS gene regarding the necessity for and success of surgery and the progression of the disease. In the NTG group, no statistical correlation was observed between G894T, T786C polymorphism variants, and risk factors such as optic disc haemorrhages, optic disc notches, and peripapillary atrophy. Mean diastolic and systolic pressure during the day and night were lowest in NTG patients with the CC variant of the T786C polymorphism. No statistical correlation was observed between the G894T and T786C polymorphisms and capillaroscopic examination results.

Conclusions

Genotype frequencies are similar for both the eNOS G894T and T-786C polymorphisms in NTG and HTG patients. These polymorphisms do not correlate with risk factors and do not influence the state of the capillary system in NTG patients. Systolic blood pressure is lower in NTG patients with mutated alleles of both polymorphisms.

Interplay between polymorphisms in the endothelial nitric oxide synthase (eNOS) gene and metabolic syndrome in determining the risk of ischemic stroke in Koreans

BACKGROUND

Endothelial nitric oxide synthase (eNOS) gene variants are known to play a role in atherosclerotic development. However, whether interplay between eNOS polymorphisms and metabolic syndrome (MetS) affects ischemic stroke (IS) risk has yet to be discovered. We investigated whether the combined effects of eNOS polymorphisms and MetS influence ischemic stroke risk in Koreans.

METHODS

We genotyped the eNOS -922A>G, -786T>C, 4a4b, and 894G>T polymorphisms in 531 IS cases and 502 controls using polymerase chain reaction-amplified DNA. We then investigated whether the presence of MetS and the number of MetS risk factors worked with eNOS polymorphisms to influence IS risk.

RESULTS

IS patients had a significantly higher prevalence of MetS than controls [adjusted odds ratio (AOR)=2.943, 95% confidence interval (CI), 2.256-3.840, P<0.0001], and MetS prevalence did not differ between stroke subtypes. The 894GT+TT genotypes were positively associated with IS (AOR=1.670, 95% CI, 1.208-2.308, P=0.002), and the -786TC+CC genotypes showed co-morbidity with MetS (AOR=1.448, 95% CI, 1.401-2.015, P=0.028). Among subjects with three or more MetS risk factors, the highest AOR value (28.490, 95% CI, 3.162-256.688) was observed for the eNOS -786TC+CC genotypes.

CONCLUSIONS

The eNOS 894T allele and interplay between the eNOS -786C allele and MetS may predispose Koreans to IS.

NOS3 894G>T polymorphism is associated with progression of kidney disease and cardiovascular morbidity in type 2 diabetic patients: NOS3 as a modifier gene for diabetic nephropathy?

BACKGROUND/AIMS

We have previously associated SNP 894G>T in the NOS3 gene with diabetic nephropathy (DN) using multi-locus analysis. Variant 894G>T has been widely studied as a DN susceptibility factor with contradictory results. In the present study we genotyped 894G>T in the cohort of prospectively followed type 2 diabetics with the aim to investigate its possible role in the progression of DN and development of morbidity and mortality associated with diabetes.

METHODS

311 subjects with defined stage of DN were enrolled in the study and followed up for a median of 38 months. We considered three end-points: progression of DN, major cardiovascular event and all-cause mortality.

RESULTS

Considering baseline GFR, age at enrolment and diabetes duration as confounders, Cox regression analysis identified 894GT genotype as a risk factor for DN progression (HR = 1.843 [95% CI 1.088 - 3.119], P = 0.023) and 894TT genotype as a risk factor for major cardiovascular event (HR = 2.515 [95% CI 1.060 - 5.965], P = 0.036).

CONCLUSION

We ascertained the significant effect of the NOS3 894G>T variant on DN progression and occurrence of major cardiovascular event in T2DM subjects. Based on these results NOS3 can be considered a modifier gene for DN.

Associations of genetic polymorphisms of SAA1 with cerebral infarction

Background

Serum amyloid A protein (SAA) is both an inflammatory factor and an apolipoprotein. However, the relation between genetic polymorphisms of SAA and cerebral infarction (CI) remains unclear.

Methods and results

The previously reported 4 Single Nucleotide Polymorphisms (rs12218, rs4638289, rs7131332, and rs11603089) of SAA1 gene were genotyped by TaqMan method in a case–control study including 287 cerebral infarction patients and 376 control subjects. We found rs12218 CC genotype and rs7131332 AA genotype were more frequent among CI patients than among controls (9.76% versus 3.19%, P = 0.001; 32.75% versus 24.20%; p = 0.017; respectively). After adjustment of confounding factors such as sex, age, smoking, drinking, hypertension, diabetes, and lipids profile, the difference remained significant in rs12218 (P < 0.01, OR = 2.106, 95% CI: 1.811–7.121).

Conclusion

Genetic polymorphism of SAA1 may be a genetic maker of cerebral infarction in Chinese.