Evidence for association of a common variant of the endothelial nitric oxide synthase gene (Glu298-->Asp polymorphism) to the presence, extent, and severity of coronary artery disease

Genetic, lifestyle and metabolic factors contributing to cardiovascular disease in the Italian population: a literature review

Cardiovascular diseases (CVD) represent a major health problem worldwide. In Italy, despite the decline in CVD mortality and disability-adjusted life years recently observed, CVD remains the leading cause of death. The development of CVD has a complex and multifactorial etiology that involves environmental, lifestyle/behavioral (e.g., unhealthy diet, physical inactivity, smoking, and alcohol abuse), metabolic, and genetic factors. Although a large number of CVD susceptibility genetic variants have been identified, some seem to confer risk according to the genetic background or ethnicity of the population. Some CVD-associated polymorphisms with appreciable frequency in the Italian population may be important contributors to the development and progression of the most prevalent CVD in the population. This literature review aims to provide an overview of the epidemiology of CVD in Italy, as well as to highlight the main genetic, lifestyle/behavioral, and metabolic factors contributing to CVD risk in this population.

Role of the SARS-CoV-2 Virus in Brain Cells

COVID-19, caused by the SARS-CoV-2 virus, can have neurological effects, including cognitive symptoms like brain fog and memory problems. Research on the neurological effects of COVID-19 is ongoing, and factors such as inflammation, disrupted blood flow, and damage to blood vessels may contribute to cognitive symptoms. Notably, some authors and existing evidence suggest that the SARS-CoV-2 virus can enter the central nervous system through different routes, including the olfactory nerve and the bloodstream. COVID-19 infection has been associated with neurological symptoms such as altered consciousness, headaches, dizziness, and mental disorders. The exact mechanisms and impact on memory formation and brain shrinkage are still being studied. This review will focus on pathways such as the olfactory nerve and blood-brain barrier disruption, and it will then highlight the interactions of the virus with different cell types in the brain, namely neurons, astrocytes, oligodendrocytes, and microglia.

Endothelial nitric oxide synthase (eNOS) gene polymorphism (Glu298asp) and nitric oxide (NO) levels in patients with ST-segment elevation myocardial infarction (STEMI)

BACKGROUND

Genetic polymorphism in endothelial Nitric Oxide Synthase (eNOS) are associated with occurrence of multiple cardiovascular diseases (CVDs).

METHODS

This study included 300 young ST-segment elevation myocardial infarction (STEMI) patients and 300 healthy controls. STEMI patients were divided into two groups: premature coronary artery disease [CAD] (STEMI<40 years of age) and older STEMI (>40 years of age). Genetic polymorphisms in the eNOS gene (894G/T) was evaluated in both subjects and controls. Plasma levels of nitric oxide (NO) were estimated for both patients as well as controls.

RESULTS

Mean age of the study population was 49.7 ± 9.2 years with premature CAD being present in 58 (19.3 %) patients. No significant difference at genotypic (P = 0.589, odds ratio (OR) = 0.9, 95 % CI = 0.6-1.6) and allelic level (P = 0.173, OR = 1.2, 95 % CI = 0.9-1.4) was observed between STEMI patients and healthy controls. Genotype 894 TT had significantly higher frequency in STEMI patients >40 years (P = 0.047, OR: 2.5; 95 % CI = 1.0-6.0). No significant difference at genotypic (P = 0.279) and allelic level (P = 0.493) was observed between premature CAD (STEMI age <40 years) and healthy controls. NO levels (131 ± 59.6 μM vs 118.11 ± 49.96 μM; P = 0.001) was significantly higher in healthy controls as compared to STEMI patients >40 years of age (P= 0.001).

CONCLUSION

There was significant association of eNOS gene polymorphism Glu298Asp with STEMI patients > 40 years. However, this association was not observed in premature CAD patients. Lower levels of NO in STEMI patients >40 years suggests its potential role as a marker of CVD.

Association of Endothelial Nitric Oxide Synthase Gene Polymorphisms with Coronary Artery Disease in North Indian Punjabi Population

Nitric oxide (NO) a potent vasodilator synthesized by endothelial cells has anti-atherosclerotic properties and maintains vascular tone. It has been documented that its reduced bioavailability in vascular endothelium plays an important role in the development and progression of coronary artery disease (CAD). Therefore, we aimed to investigate the association of - 786 T > C and 894 G > T polymorphisms of eNOS with CAD. This study included 211 CAD patients and 260 controls of North Indian Punjabi population. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Logistic regression analysis revealed that the TC and CC genotypes of - 786 T > C were significantly associated with the higher risk of CAD (OR: 2.00, p = 0.001: OR: 4.63, p = 0.001, respectively). Similarly, the GT and TT genotypes of 894 G > T were found to be significantly associated with the higher risk of CAD (OR: 1.96, p = 0.001; OR: 4.54, p = 0.005, respectively). Moreover, the recessive model in  - 786 T > C (OR: 3.58, p = 0.002) and 894 G > T (OR: 3.62, p = 0.009) polymorphisms provided 3.6-fold increased risk for CAD. Furthermore, the CG, TT, and CT haplotypes were also associated with the increased risk of CAD (OR: 2.1, p = 0.001; OR: 2, p = 0.002; OR: 3.1, p = 0.001, respectively). In addition, the CC genotype of - 786 T > C and GT genotype of 894 G > T were significantly associated with higher levels of triglycerides (TG) and very low-density lipoproteins cholesterol (VLDL-C). The present study reported the association of - 786 T > C and 894 G > T polymorphisms of eNOS with CAD and abnormal lipid levels in North Indian Punjabi population.

Participation of nitrogen oxide and its metabolites in the genesis of hyperimmune inflammation in COVID-19

Despite the success in the tactics of treating COVID-19, there are many unexplored issues related to the development and progression of the process in the lungs, brain, and other organs, as well as the role of individual elements, in particular, nitric oxide (NO), and in the pathogenesis of organ damage. Based on the analyzed literature data, we considered a possible pathophysiological mechanism of action of NO and its derivatives in COVID-19. It can be noted that hyperimmune systemic inflammation and "cytokine storm" are enhanced by the production of NO, products of its oxidation ("nitrosative stress"). It is noted in the work that as a result of the oxidation of NO, a large amount of the toxic compound peroxynitrite is formed, which is a powerful proinflammatory agent. Its presence significantly damages the endothelium of the vascular walls and also oxidizes lipids, hemoglobin, myoglobin, and cytochrome, binds SH-groups of proteins, and damages DNA in the target cells. This is confirmed by the picture of the vessels of the lungs on computed tomography and the data of biochemical studies. In case of peroxynitrite overproduction, inhibition of the synthesis of NO and its metabolic products seems to be justified. Another aspect considered in this work is the mechanism of damage by the virus to the central and peripheral nervous system, which remains poorly understood but may be important in understanding the consequences, as well as predicting brain functions in persons who have undergone COVID-19. According to the analyzed literature, it can be concluded that brain damage is possible due to the direct effect of the virus on the peripheral nerves and central structures, and indirectly through the effect on the endothelium of cerebral vessels. Disturbances in the central nervous regulation of immune responses may be associated with the insufficient function of the acetylcholine anti-inflammatory system. It is proposed to further study several approaches to influence various links of NO exchange, which are of interest for theoretical and practical medicine.

Association of eNOS (G894T, rs1799983) and KCNJ11 (E23K, rs5219) gene polymorphism with coronary artery disease in North Indian population

Background

Endothelial nitric oxide synthase (eNOS) and potassium voltage-gated channel subfamily J member 11 (KCNJ11) could be the candidate genes for coronary artery disease (CAD). This study investigated the relationship of the eNOS (rs1799983) and KCNJ11 (rs5219) polymorphisms with the presence and severity of CAD in the North Indian population.

Methods

This study included 300 subjects, 150 CAD cases and 150 healthy controls. Single nucleotide polymorphism was evaluated by Polymerase chain reaction and Restriction fragment length polymorphism (PCR-RFLP). Analysis was performed by SPSS (version 21.0).

Results

We observed that KK genotype of KCNJ11E23K (rs5219) polymorphism (P=0.0001) genotypes and K allele (P=0.0001) was found to be a positive risk factor and strongly associated with CAD. In the case of eNOSG894T (rs1799983) there was no association found with CAD.

Conclusion

These results illustrate the probability of associations between SNPs and CAD although specific genetic polymorphisms affecting ion channel function and expression have still to be clarified by further investigations involving larger cohorts.

Interaction between eNOS gene polymorphism and current smoking on susceptibility to coronary heart disease in Chinese people

OBJECTIVE

This study aims to explore the relation between endothelial nitric oxide synthase (eNOS) single-nucleotide polymorphisms (SNPs) and the risk of coronary heart disease (CHD).

METHODS

SNPstats (online software: http://bioinfo.iconcologia.net/SNPstats) was performed to test Hardy-Weinberg equilibrium in controls. Generalized multifactor dimensionality reduction (GMDR) was adopted to screen the preferable interaction between eNOS SNPs and smoking.

RESULTS

The frequency for the rs1799983-T allele was 31.1% in CHD patients, which was significantly higher than that of 19.8% in controls (P < 0.05). The frequency for the rs891512-A allele was 28.8% in cases, which was also significantly higher than that of 20.1% in controls (P < 0.05). Logistic regression analysis showed that both rs1799983-T and rs891512-A alleles were related with increased risk of CHD, and the odds ratios (ORs) [95% confidence interval (CI)] were 1.71 (1.31-2.15) and 1.57 (1.14-2.07), respectively. High-order interactions were investigated among SNPs and environmental factors using the GMDR method. The data showed that a two-locus model (rs1799983 × smoking) had a testing accuracy of 0.60 (P = 0.001). We found that current smokers with rs1799983-GT or TT within eNOS gene have the highest CHD risk, compared to never smokers with rs1799983-GG genotype, OR (95% CI) = 2.74 (1.78-3.85), after covariates adjustment for age, gender, BMI, and alcohol drinking.

CONCLUSION

The rs1799983-T and rs891512-A alleles and interaction between rs1799983 and smoking were all risk factors of CHD.

NOS3 Gene rs1799983 and rs2070744 Polymorphisms in Patients with Unstable Angina

Acute coronary syndrome occurs when the heart muscle does not receive adequate oxygen and nutrients in a timely manner. Acute coronary syndromes are primarily due to atherosclerosis of the coronary arteries, i.e., coronary heart disease. Nitric oxide (NO) is synthesised from L-arginine in endothelial cells by the constitutive calcium-calmodulin-dependent enzyme, nitric oxide synthase (NOS), which mediates endothelium-dependent vasodilatation. Endothelial nitric oxide synthase (eNOS) is predominantly expressed in endothelial cells. Three NOS isoforms have been detected in different tissue: (1) neuronal NOS (nNOS) (NOS1), (2) eNOS (NOS2), and (3) inducible NOS (iNOS) (NOS3). These isoforms are encoded by three different genes. NOS3 is located on chromosome 7q35-36 and contains 26 exons. Previous studies have suggested that NOS3 polymorphisms may be associated with acute coronary syndromes. Therefore, the aim of the study was to examine the associations between NOS3 rs1799983 (894G/T)andrs2070744 (-786T/C) polymorphisms and unstable angina. This study included 246 patients with unstable angina, as confirmed by coronary angiography. We also included 189 healthy controls who were also assessed by this technique. There were no significant differences in genotype distributions of NOS3 rs1799983and rs2070744 polymorphisms in patients with unstable angina and healthy controls in both univariate and multivariate analyses. In patients with the NOS3 rs1799983 TT genotype, we observed a higher BMI (TT vs. GT + GG, p = 0.068), and in patients with the NOS3 rs2070744 TT genotype, we observed a higher waist circumference (TT vs. TC + CC, p = 0.023; TT vs. CC, p = 0.0053). These data suggest a lack of association between the NOS3 rs1799983andrs2070744 polymorphisms and unstable angina in our patient population. However, these polymorphisms may be associated with some obesity parameters, rs1799983 in females and rs2070744 in males.

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.

Association of endothelial nitric oxide synthase (eNOS) and norepinephrine transporter (NET) genes polymorphism with type 2 diabetes mellitus

Genetic factors in combination with environmental factors play a critical role in the development type 2 diabetes mellitus (T2DM) which is growing as an epidemic globally. In present study we aim to assess the association of eNOS (G894T, rs1799983) and NET (G1287A, rs5569) genes polymorphism with T2DM. A case-control study including a total of 400 North Indian subjects (200 T2DM cases and 200 controls) was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach to analyze genetic polymorphism. Alleles/genotype frequencies between cases and controls were compared using χ² and Student's t-tests. Odds ratios and 95% confidence intervals were calculated by logistic regression to assess the relative association between disease and genotypes. In case of NET gene, GG (P = 0.002 in T2DM males, 0.053 in overall T2DM cases) genotype and G allele (P = 0.003 in T2DM males, 0.027 in overall T2DM cases) were found to be a positive risk factors and AG genotype (P = 0.012 in T2DM males) and A allele (P = 0.003 in T2DM males, P = 0.027 in overall T2DM cases) as negative risk factor for T2DM. No association of eNOS gene polymorphism was found with T2DM (P values of all genotypes and alleles were greater than 0.05). NET gene polymorphism might be associated with the risk of T2DM whereas; eNOS gene polymorphism do not confer any risk of T2DM in North Indian Ethnic group. It is hoped that understanding genetic causes of T2DM will lead to earlier diagnosis, preventive measures and more effective and specific treatment.

The contribution of NOS3 variants to coronary artery disease: A combined genetic epidemiology and computational biochemistry perspective

Cardiovascular diseases, particularly coronary artery disease (CAD) and myocardial infarction, are the leading cause of death among people worldwide. CAD is exceedingly complex in its interplay of environment and genetics, with numerous genetic loci contributing to its heritability. Here, we aim at looking into the effects of the NOS3 c.894G>T and 27-bp VNTR polymorphisms on susceptibility to CAD in a population of Turkish Cypriots, at seeing whether these effects correlate with plasma lipid levels and at predicting the functional consequences of each polymorphism tested. A total of 50 subjects with CAD and 100 otherwise healthy subjects were included in the present case-control study. Genomic DNA was extracted from peripheral blood samples, and the two NOS3 polymorphisms were determined by restriction endonuclease analysis of PCR amplicons. Complementary methods of statistical analysis and computational modeling were employed accordingly to achieve the aims above. Our findings show that the 27-bp VNTR polymorphic locus, but not the c.894G>T polymorphic locus, is associated with CAD and that it may regulate NOS3 pre-mRNA splicing in a length-dependent manner. Overall, along with additional, yet-to-be ascertained susceptibility markers the 27-bp VNTR 4a/4b marker may be employed in risk stratification in community-level screening for CAD among Turkish Cypriots.

Endothelial nitric oxide synthase Glu 298 Asp (G894T) and Apolipoprotein E gene polymorphism as possible risk factors for coronary heart disease among Egyptians

In Egypt, The prevalence of chronic heart disease (CHD) is 8.3%. It is the principal cause of death and is responsible for 22% of total mortality. The age-adjusted mortality rate is 174 per 100,000 of population. There are many studies on traditional risk factors and CHD in Egypt but the study of novel risk factors is deficient.

Objectives

The aim of the present case control study was to investigate the relation between CHD susceptibility and Endothelial Nitric Oxide Synthase (eNOS) Glu 298 Asp (G894T) and Apolipoprotein E (ApoE) gene polymorphism in a cohort of Egyptian individuals.

Methods

Genotyping of eNOS (Glu298Asp) and Apo E genes polymorphisms were done using polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) method for 100 CHD cases and 100 age and sex matched healthy controls.

Results

A statistically significant association was observed between GT and TT genotypes of endothelial nitric oxide synthase gene with CHD with OR = 2.03 and 3.5; respectively. Also, carriers of E4 allele and especially E3/E4 genotype were at higher risk of CHD with OR = 3.3 for both. Significant association was also observed between the presence of combined GTE3E4 genotype and CHD with OR = 6.6.

Conclusion

GT and TT genotypes of endothelial nitric oxide synthase gene, E3/E4 genotype of Apo E gene polymorphism and combined GTE3E4 genotype can be considered risk factors for the development of CHD among Egyptians.

Meta-Analysis of NOS3 G894T Polymorphisms with Air Pollution on the Risk of Ischemic Heart Disease Worldwide

The purpose of this updated meta-analysis was to investigate the effect of nitric oxide synthase-3 (NOS3) G894T polymorphisms, air pollution and their interaction on ischemic heart disease (IHD) risk across populations worldwide. Recursive partition trees, nonlinear association curve fit and geographic information system maps were incorporated to verify results of conventional pooled analyses for sources of heterogeneity. Results from 61 studies (16,219 cases, 12,222 controls) revealed a significant increased relative risk (RR) of IHD associated with NOS3 894 polymorphisms TT (RR = 1.44) and GT (RR = 1.37). Subgroup analysis revealed that the TT polymorphism genotype had significantly increased risk of IHD in Caucasian, East Asian, South Asian, and Middle Eastern populations (all p < 0.05). It is important to point out that many countries demonstrated an average risk of greater than two, which identifies the NOS3 894 TT polymorphism as a potential causal factor and biological marker of IHD, based on criteria for strong evidence used in international consensus panels. These 10 countries include Ukraine, the United Kingdom, Brazil, Chile, Japan, South Korea, India, Iran, Egypt and Morocco. For these countries with elevated risk (RR > 2) from the NOS3 894 TT polymorphism, meta-predictive analysis demonstrated an increasing trend in air pollution association with increased NOS3 894 polymorphisms. Further studies are needed to explore the complexity of the associations among NOS3 gene polymorphisms per population stratifications within countries, detailed air pollution data for added specificity for geographic location across time, and disease risk.

The polymorphism G894 T of endothelial nitric oxide synthase (eNOS) gene is associated with susceptibility to essential hypertension (EH) in Morocco

BACKGROUND

Hypertension is a multifactorial disease involving both environmental and genetic Factros. G894 T eNOS polymorphism has been suggested to be responsible for reduced NO synthesis, and EH development. The objective of our case-control study is to evaluate the potential association of G894 T eNOS polymorphism with Essential Hypertension (EH) susceptibility, among a sample of Moroccan patients.

METHODS

One hundred forty five hypertensive patients were recruited from the department of Cardiology, University Hospital Center Ibn Rochd, Casablanca, Morocco, and compared to 184 apparently healthy subjects. DNA samples were genotype by PCR-RFLP method using MboI restriction enzyme.

RESULTS

Our results showed a positive correlation between G894 T eNOS distribution and Alcohol and Obesity rik factors (P = 0.009 and 0.02 respectively). Patients with elevated Cardio Vascular Risk (CVR) carried out the higher frequency of homozygous mutant genotype TT (62.2%) and T mutant allele (77.8%), compared to median and low CVR groups. G894 T eNOS distribution was significantly associated to a high risk of EH occurrence under the GT and TT genotypes (OR [95% CI] = 20.2 [7.7-52.4], P <  0.0001; OR [95% CI] = 332.5 [98.2-1125.4], P <  0.0001 respectively), and the 3 genotypic transmission models (Dominant: OR [95% CI] = 43.2 [17.9-104.09], P <  0.0001; Recessive: OR [95% CI] = 47.7 [18.6-122.3]; P <  0.0001; Additive: OR [95% CI] = 14.02 [9.6-20.45], P <  0.0001).

CONCLUSION

Our study suggests a strong association of G894 T eNOS polymorphism with susceptibility to EH in Morocco. Studies trying to identify contributing genes may be very useful and allow recognizing the vulnerable individuals and classifying patients in subgroups with definite genetic and pathogenic mechanisms to achieve better prevention and therapeutics.

Nitric oxide signalling in cardiovascular health and disease

Nitric oxide (NO) signalling has pleiotropic roles in biology and a crucial function in cardiovascular homeostasis. Tremendous knowledge has been accumulated on the mechanisms of the nitric oxide synthase (NOS)-NO pathway, but how this highly reactive, free radical gas signals to specific targets for precise regulation of cardiovascular function remains the focus of much intense research. In this Review, we summarize the updated paradigms on NOS regulation, NO interaction with reactive oxidant species in specific subcellular compartments, and downstream effects of NO in target cardiovascular tissues, while emphasizing the latest developments of molecular tools and biomarkers to modulate and monitor NO production and bioavailability.

The association between an endothelial nitric oxide synthase gene polymorphism and coronary heart disease in young people and the underlying mechanism

With the development of molecular biological technology, the association between genes and diseases has drawn increasing attention of researchers; the endothelial nitric oxide synthase (eNOS) gene has been reported to be a candidate gene for cardiovascular disease (CHD). The present study aimed to investigate the association between a polymorphism of eNOS and the risk of CHD in young people (≤40 years old), in addition to the underlying mechanism. A total of 234 cases of CHD in young individuals were collected as the CHD group and 228 cases of healthy individuals as the control group. Peripheral blood was collected and the genotype of the eNOS G894T polymorphism was identified by polymerase chain reaction-restriction fragment length polymorphism, the gene frequency was calculated and the distributions of genotype and allele frequency between the two groups were compared. Bioinformatics tools were employed to analyze the differences in the local protein structures of the eNOS G894T polymorphism and the biological mechanism was preliminary discussed. The results demonstrated that there were significant differences in the distribution of genotype frequency and allele frequency of the eNOS G894T gene polymorphism between the CHD group and control group (P<0.05). The risk of CHD in GT and TT genotypes were higher compared with the GG genotype (P<0.05). The G894T polymorphism led to Glu298Asp mutation of encoded protein, which is within the active site of eNOS, and partial structures of the protein were converted from random coil to α‑helix. In conclusion, the eNOS G894T gene polymorphism was associated with the occurrence and development of CHD in young people. The potential mechanism is that the G894T polymorphism leads to altered protein structure, which affects the function of eNOS in generating nitric oxide and cardiovascular diastole. The results of the present study suggested a potential target gene for the prevention and treatment of CHD in young people (≤40 years old).

NOS3 gene variants and male infertility: Association of 4a/4b with oligoasthenozoospermia

Results of recent studies confirmed that oxidative stress negatively affects sperm motility and causes sperm DNA damage. Produced by nitric oxide synthase 3 (NOS3), nitric oxide is considered to be one of the important mediators of oxidative stress in testis tissue. The aim of this study was to assess the possible association of three genetic variants (rs2070744, rs1799983 and intron variant 4a/4b) in NOS3 gene and infertility occurrence in two groups of infertile men (idiopathic azoospermia and oligoasthenozoospermia) and fertile controls. Genotypes for the single-nucleotide genetic variants rs1799983 and rs2070744 were determined by PCR-RFLP, while genotyping of intron 4 variant 4a/4b was performed by gel electrophoresis of PCR products. Statistical analysis was performed by SNPStats software. No significant association between the three genetic variants of the NOS3 gene and infertility risk was determined comparing allele and genotype frequencies among group of patients diagnosed with azoospermia and the control group. Nevertheless, there was a significant positive association between 4a/4b and infertility in the group of males diagnosed with oligoasthenozoospermia, under overdominant genetic model. Our findings suggest that tandem repeat variant within intron 4 of the NOS3 gene is associated with an increased risk of infertility in men diagnosed with idiopathic oligoasthenozoospermia.

The Endothelial Nitric Oxide Synthase Gene T-786C Polymorphism Increases Myocardial Infarction Risk: A Meta-Analysis

Background

Polymorphisms of the endothelial nitric oxide synthase (eNOS) gene are reportedly associated with myocardial infarction (MI) risk. However, definitive evidence of this association is lacking. In this study, we investigated the potential association of eNOS gene polymorphisms with MI risk by conducting a meta-analysis of studies evaluating this association.

Material/Methods

PubMed, Web of Knowledge, ScienceDirect, China National Knowledge Infrastructure (CNKI), WanFang, and Database of Chinese Scientific and Technical Periodicals (VIP) were searched for relevant studies. Pooled odds ratios (OR) with 95% confidence interval (CI) were calculated to evaluate the association of eNOS gene T-786C and 4b4a polymorphisms with MI risk.

Results

Fifteen studies with 8,067 controls and 4,923 MI cases were included in the final meta-analysis. In the overall analysis, T-786C (rs2070744) polymorphism was associated with MI risk (p<0.05, OR=1.69, 95% CI: 1.53–1.86 for T vs. C; p<0.05, OR=2.76, 95% CI: 2.03–3.75 for TT vs. CC; p<0.05, OR=1.74, 95% CI 1.56–1.95 for TT vs. (CT + CC); p<0.05, OR=2.43, 95% CI: 1.79–3.30 for (CT + TT) vs. CC). In addition, a significant association between 4b4a VNTR polymorphism and MI risk was observed. On sub-group analyses by ethnicity, a significant increase in MI risk was observed separately for Asian and Caucasian populations for T-786C polymorphism, but not for the 4b4a polymorphism.

Conclusions

In this meta-analysis, T-786C polymorphism of the eNOS gene was associated with the risk of MI, especially in the Asian populations.

Both T-786C and G894T polymorphism of endothelial nitric oxide synthase affect in-vitro endothelium-dependent relaxation of internal mammary artery rings from patients with coronary artery disease

OBJECTIVES

Polymorphisms of endothelial nitric oxide synthase (eNOS) gene in the promoter (T-786C) and exon 7 (G894T) have been suggested to attenuate endothelial function. As it is unknown whether these polymorphisms, on top of classical risk factors, further deteriorate endothelium-dependent vasomotion, we aimed to elucidate the impact of both polymorphisms on the ex-vivo vasomotor function of left internal mammary artery rings from patients with coronary artery disease (CAD) undergoing coronary bypass surgery (CABG).

METHODS

Mammary artery rings from 51 consecutive patients with CAD were obtained during elective CABG. Endothelium-dependent ring relaxation was measured in vitro in an organ chamber using acetylcholine (10 to 3 x 10 mol/l). Polymorphisms were determined by polymerase chain reaction restriction length polymorphism.

RESULTS

Thirty-three per cent of patients were positive for the T-786C polymorphism, 25% for the G894T polymorphism, and 18% carried mutated alleles in both loci. Maximal acetylcholine-induced ring relaxation was 46.7+/-3.2% in T-786C, 59.6+/-4.2% in G894T, and 66.7+/-7.4% in T-786C/G894T compared with 94.9+/-2.0% in wild-type subjects (P<0.05 versus T-786C, G894T, T-786C/G894T). Patients positive for an eNOS polymorphism with more than three cardiovascular risk factors displayed a further attenuation of acetylcholine-mediated relaxation (45+/-6 %) compared with having up to three risk factors (59+/-3%, P<0.05).

CONCLUSION

In patients with CAD, in-vitro assessed endothelium-dependent relaxation of mammary arteries was significantly impaired in those positive for the T-786C or the G894T eNOS polymorphism. These results suggest that the presence of either one of the eNOS polymorphisms deteriorated endothelium-dependent vasodilatory capacity of large conduit vessels on top of classical risk factors in patients with CAD.

Polymorphisms in NOS3, MTHFR, APOB and TNF-α Genes and Risk of Coronary Atherosclerotic Lesions in Iranian Patients

Background:

Atherosclerosis is a complex multifocal arterial disease involving interactions between multiple genetic and environmental factors.

Objectives:

In the present study, we investigated the possible association between NOS3 (rs1799983), MTHFR (rs1801133), APOB (rs5742904) and TNF-α (rs361525) polymorphisms and the risk of coronary atherosclerotic lesions in Iranian patients.

Patients and Methods:

In the case-control study, 108 patients with coronary atherosclerosis disease and 95 control subjects with no family history of cardiovascular disease were enrolled. Genotypes for NOS3, MTHFR, APOB and TNF-α polymorphisms were identified using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP).

Results:

We specifically detected the NOS3 TT genotype in 12 patients (11.11%) and did not find the same genotype in any of the controls. The frequencies of T allele in patients and the controls were 24% and 17.8%, respectively. The prevalence of the MTHFR TT genotype was 16.7% in patients and 2.2% in control groups. The prevalence of the APOB-100 (R3500Q) mutation in this patient population was 0%. The frequency of the A allele in the TNF-α gene was 11.1% and 11% in patients and controls, respectively, and the AA genotype was undetected.

Conclusions:

Our results show a significant association of NOS3 and MTHFR gene polymorphisms with coronary atherosclerotic lesions. Therefore, these variants might influence the risk of coronary artery disease, specifically in the Iranian population.

Relation between Endothelial Nitric Oxide Synthase Genotypes and Oxidative Stress Markers in Larynx Cancer

Nitric oxide synthase (eNOS/NOS3) is responsible for the endothelial synthesis of nitric oxide (NO(•)). G894T polymorphism leads to the amino acid substitution from Glu298Asp that causes lower NOS3 activity and basal NO(•) production in NOS3 894T (298Asp) allele carriers compared with the GG homozygotes. NO(•) acts as an antioxidant protecting against Fenton's reaction which generates highly reactive hydroxyl radicals. Allelic variation of NOS3 may influence an individual's risk of laryngeal cancer (LC). In the current study we have examined the possible relationship between NOS3 G894T genotypes and various systemic oxidative damage markers such as protein carbonyl, advanced oxidation protein products, Cu, Zn-superoxide dismutase, thiol group fractions, and lipid hydroperoxides in LC patients. Genotyping was carried out by PCR-RFLP. In LC patients with TT genotype, Cu, Zn-superoxide dismutase activities and nonprotein thiol levels were significantly higher than the controls. In patients with GT and GG genotype, high levels of lipid hydroperoxides showed statistical significance when compared to controls. Our results indicate a potential relationship among G894T polymorphism of NOS3, and impaired redox homeostasis. Further studies are required to determine the role of NOS3 gene polymorphism and impaired plasma redox homeostasis.

Angiogenesis related genes NOS3, CD14, MMP3 and IL4R are associated to VEGF gene expression and circulating levels in healthy adults

BACKGROUND

Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis. The aim was to assess the genetic connections between the angiogenesis-related NOS3, CD14, MMP3, IL4R, IL4 genes and VEGF expression and plasma levels.

METHODS

The associations between VEGF plasma levels with the polymorphisms of NOS3, CD14, MMP3, IL4R, and IL4 were assessed in 403 healthy unrelated adults. The epistatic and environmental interactions were explored, including four VEGF-related polymorphisms previously identified. The VEGF expression in peripheral blood mononuclear cells was quantified (n = 65) for the VEGF121, VEGF145, VEGF165, and VEGF189 isoforms.

RESULTS

The polymorphism rs1799983 of NOS3 was associated with the sum of all VEGF isoforms mRNA levels (P = 0.032) and VEGF145 (P = 0.033). Rs1800779 of NOS3 interacted with rs3918226 of the same gene and with the rs2569190 of CD14 (P = 0.022, P = 0.042, respectively) for VEGF plasma levels. Other epistatic interactions included the rs1801275 of IL4R with the rs6921438 (VEGF-related variant) and rs3025058 of MMP3 (P = 0.042, P = 0.010 respectively) and the rs2569190 of CD14 with the rs3025058 of MMP3 (P = 0.0119). We also identified an interaction of rs1800779 with obesity, high-density lipoprotein cholesterol and triglycerides (P = 0.018, P = 0.005, P = 0.043, respectively) as well as the interaction of rs6921438 with hypertension (P = 0.028).

CONCLUSIONS

Our findings indicated that genetic variants of NOS3, CD14, MMP3 and IL4R are implicated in the determination of VEGF expression and plasma levels. Thus, they support the hypothesis that in physiological conditions there are complex biological relationships between pathways (such as angiogenesis and inflammation), which are involved in the development of chronic diseases.

[Intracranial aneurysms and their clinical and genetic behaviour]

BACKGROUND

Intracranial aneurysms are abnormal dilations of the cerebral arteries of unknown origin. However, some genes have been linked to their formation, as in the case of NOS3 gene which encodes the endothelial nitric oxide synthase responsible for producing nitric oxide. Several polymorphisms in this gene, in association with a variable number tandem repeat located in intron 4 from eNOS4 gene, can influence the formation of aneurysms. Therefore, the purpose of this study is to determine the genotype frequencies of eNOS3 and eNOS4 genes, and their relationship with intracranial aneurysms.

MATERIAL AND METHODS

A prospective case-control study was performed on 79 cases with ruptured intracranial aneurysm and 93 healthy controls. DNA was obtained from all subjects for the study of the eNOS3 and eNOS4 genes by molecular techniques.

RESULTS

The GG genotype of eNOS3 gene showed the largest number of patients (n=29) with a large aneurysm. While the intracranial aneurysms of medium size were found in a higher percentage (50%) in patients with genotype GT. In terms of patient outcomes, it was observed that those with genotype GG had the highest percentage (43.13%) recovery, compared to genotype GT (27.27%).

CONCLUSIONS

The present study shows that there is a tendency of an association between genotypes of eNOS3 gene with the mean size of the aneurysm, as well as clinical sequelae of the disease in patients with intracranial aneurysms.

Endothelial nitric oxide synthase polymorphism and prognosis in systolic heart failure patients

BACKGROUND

The endothelial nitric oxide synthase (eNOS) gene single nucleotide polymorphism G894T is associated with thrombotic vascular diseases. However, its functional significance is controversial and data are scarce concerning its influence in heart failure (HF).

METHODS

We studied 215 patients with chronic systolic HF. DNA was analyzed for eNOS gene G894T polymorphism using PCR and DNA sequencing. Evaluation of clinical characteristics and analysis of factors associated with 2-year mortality were performed for the homozygous G-allele G894T variant (GG), relative to the TT and GT variants.

RESULTS

The genotype distributions of eNOS G894T alleles were: GG 135 patients (63%) and TT/GT 80 (37%). Two-year mortality was significantly higher in the GG variant (48%) than the combined TT/GT group (32%). The usage of nitrates was associated with increased 2-year mortality (HR 2.0, 95% CI 1.28-3.17; p = 0.003), which was most significant in the GG group treated with nitrates (73.5%) in comparison to the TT/GT group not treated with nitrates (34%); HR 2.75, 95% CI 1.57-4.79, P < 0.001.

CONCLUSIONS

Homozygosity for the G allele of the eNOS G894T polymorphism was associated with worse survival in systolic HF patients, especially in those treated with nitrates. ENOS polymorphism may result in different mechanistic interactions in HF than in thrombotic vascular diseases, suggesting that overexpression of NO may be associated with deleterious effects in systolic HF.

Contribution of eNOS variants to the genetic susceptibility of coronary artery disease in a Tunisian population

Nitric oxide (NO), produced by the enzyme endothelial nitric oxide synthase (eNOS), has critical roles in the regulation of vascular homeostasis and prevention of atherogenesis by inhibiting leukocytes, platelet activation, and smooth muscle cell proliferation. There is strong experimental and clinical evidence that abnormalities in eNOS availability play an important role in the pathophysiology of coronary artery disease (CAD). Controversial results regarding the association of eNOS gene polymorphisms with CAD have been reported. The aim of this study is to investigate the relationship of the 894G>T (rs1799983) and 4a/4b (rs61722009) polymorphisms of the eNOS gene with the presence of CAD in the Tunisian population. A total of 332 patients with CAD and 368 controls were included in this study. The 894G>T (rs1799983) single-nucleotide polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism, and 4a/4b (rs61722009) polymorphism just by polymerase chain reaction (PCR). eNOS rs1799983 was significantly associated with CAD under the additive, dominant, but not recessive, models (additive model OR: 2.81; 95% CI [2.05-3.85]; p<0.001, dominant model OR: 2.84; 95% CI [2.09-3.86]; p<0.001, and recessive models p=0.09). This remained significant after adjustment for age, gender, diabetes, smoking, and hypertension. In contrast to eNOS rs1799983, eNOS rs61722009 was not associated with CAD under any of the genetic models tested. These findings suggest that the G894T (rs1799983) polymorphism of the eNOS gene was associated with CAD in Tunisian patients.

Associations of the eNOS G894T gene polymorphism with target organ damage in children with newly diagnosed primary hypertension

BACKGROUND

The endothelial nitric oxide synthase (eNOS) G894T gene polymorphism is associated with the risk of primary hypertension (PH) and vascular complications in adults with PH.

METHODS

We explored the associations of the G894T polymorphism with 24-h ambulatory blood pressure, left ventricular mass (LVM), carotid intima media thickness (cIMT), urinary albumin excretion, oxidative stress and inflammatory parameters in 126 children with newly diagnosed PH and in 83 healthy children.

RESULTS

Among the 126 children with PH 92 (73%) had ambulatory hypertension and 34 (27%) had severe ambulatory hypertension. Left ventricular hypertrophy (LVH) was detected in 39 (31%) patients, cIMT of >2 standard deviation scores in 21 (16.6%) patients, albuminuria of >30 mg/24 h in 18 (14.3%) patients and metabolic syndrome (MS) in 22 (17.5%) patients. The frequency of the T allele was 52.4% in the PH group and 54.2% in the control group (not significant), and in both groups the frequency of the T allele was consistent with the Hardy-Weinberg equilibrium. Compared with G allele carriers, hypertensive T allele carriers had increased cIMT (p < 0.05) and more severe albuminuria (not significant, p = 0.1); there was no difference between the groups in hypertension severity and LVM. T and G allele distribution did not differ between patients with and without metabolic syndrome. No significant correlations between the assessed parameters and the eNOS G894T gene polymorphism were found in the controls, although T allele carriers tended to have an increased cIMT (p = 0.09).

CONCLUSION

The eNOS T allele is not more prevalent among hypertensive children than among healthy ones, but it is associated with early vascular damage in children with PH, independent of metabolic abnormalities. No associations between the eNOS G894T polymorphism and metabolic abnormalities were found.

Association of endothelial nitric oxide synthase gene polymorphisms with coronary artery disease: an updated meta-analysis and systematic review

Several association studies of endothelial nitric oxide synthase (NOS3) gene polymorphisms with respect to coronary artery disease (CAD) have been published in the past two decades. However, their association with the disease, especially among different ethnic subgroups, still remains controversial. This prompted us to conduct a systematic review and an updated structured meta-analysis, which is the largest so far (89 articles, 132 separate studies, and a sample size of 69,235), examining association of three polymorphic forms of the NOS3 gene (i.e. Glu298Asp, T786-C and 27bp VNTR b/a) with CAD. In a subgroup analysis, we tested their association separately among published studies originating predominantly from European, Middle Eastern, Asian, Asian-Indian and African ancestries. The pooled analysis confirmed the association of all the three selected SNP with CAD in three different genetic models transcending all ancestries worldwide. The Glu298Asp polymorphism showed strongest association (OR range = 1.28–1.52, and P<0.00001 for all comparisons), followed by T786-C (OR range = 1.34–1.42, and P<0.00001 for all comparisons) and 4b/a, (OR range = 1.19–1.41, and P≤0.002 for all comparisons) in our pooled analysis. Subgroup analysis revealed that Glu298Asp (OR range = 1.54–1.87, and P<0.004 for all comparisons) and 4b/a (OR range = 1.71–3.02, and P<0.00001 for all comparisons) have highest degree of association amongst the Middle Easterners. On the other hand, T786-C and its minor allele seem to carry a highest risk for CAD among subjects of Asian ancestry (OR range = 1.61–1.90, and P≤0.01 for all comparisons).

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.

Possible relation between the NOS3 gene GLU298ASP polymorphism and bladder cancer in Turkey

Endothelial nitric oxide synthase (eNOS), encoded by the NOS3 gene, has been suggested to play an important role in uncontrolled cell growth in several cancer types. The objective of this study was to evaluate the role of the NOS3 Glu298Asp polymorphism in bladder cancer susceptibility in a Turkish population. We determined the genotypes of 66 bladder cancer cases and 88 healthy controls. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. A significant association for NOS3 Glu298Asp heterozygotes genotypes and T allely were found between healthy controls and bladder cancer, respectively (p<0.001: p=0.002). There were no significant associations between any genotypes and the stage, grade, and histological type of bladder cancer. Our study suggested an increased risk role of NOS3 GT genotype in bladder cancer susceptibility in our Turkish population.

Polymorphisms of the NOS3 gene and risk of myocardial infarction in the Tunisian population

Controversial results regarding the association of eNOS gene (NOS3) polymorphisms with myocardial infarction (MI) have been reported. This study investigated the relationship of the -786T>C (rs2070744), 894G>T (rs1799983) and 4a4b polymorphisms of the NOS3 gene with the presence of MI in the Tunisian population. In addition, we also examined the association of NOS3 gene haplotypes with MI in Tunisian subjects. A total of 303 patients with MI and 225 controls were included in the study. The 894G>T and -786T>C single nucleotide polymorphisms were analyzed by PCR-RFLP, and 4a4b polymorphism just for PCR. There was significant linkage disequilibrium between the three NOS3 polymorphisms (p<0.0001). The genotype distribution and allele frequency of NOS3 4a4b, but not -786T>C and 894G>T, polymorphism was significantly different between MI patients and controls. The univariate logistic regression analysis showed a significant association of the 4a4b polymorphism and MI according to co-dominant, dominant and recessive models (co-dominant model OR: 4.38, 95%CI: 1.24-15.41; p=0.021, dominant model OR: 1.66, 95%CI: 1.14-2.42); p=0.007, and recessive model OR: 3.85, 95%CI: 1.10-13.47; p=0.035). The multivariate analysis, adjusted for traditional cardiovascular risk factors, revealed that the NOS3 4a4a genotype was an independent predisposing factor to MI, according to the models considered. In addition, a haplotype 7 (C-T-4a), (OR=12.05, p=0.010) was a risk factor of MI after controlling for classical risk factors. These finding suggest that the 4a4b polymorphism of the NOS3 gene was associated with MI in Tunisian patients.

Influence of endothelial nitric oxide synthase gene polymorphisms (-786T/C, 4a4b, 894G/T) on Iranian kidney transplant recipients

OBJECTIVES

Nitric oxide is a major mediator in vascular biology and regulator of regional blood flow. Its production is catalyzed by the enzyme endothelial nitric oxide synthase. Protective actions of nitric oxide in ischemia and reperfusion are due to its potential as an antioxidant and anti-inflammatory agent, along with its inhibitory effects on cell signaling pathways of nuclear proteins, such as NF-kB. The endothelial nitric oxide synthase gene polymorphisms affect endothelial nitric oxide synthase activity and are associated with endothelial dysfunction. This study sought to examine the association between single nucleotide polymorphisms in endothelial nitric oxide synthase gene (rs 2070744, 27VNTR, and rs1799983) and the development of acute rejection in renal transplant patients.

MATERIALS AND METHODS

Sixty-six renal transplant recipients (33 patients with an episode of acute rejection and 33 recipients an episode of acute rejection), between June 2010 and March 2011, were included. The polymorphism was determined by simple polymerase chain reaction and polymerase chain reaction-restriction fragment-length polymorphism analysis.

RESULTS

There was only a significant association of endothelial nitric oxide synthase -786T allele and acute rejection (P = .03). Recessive model of T-786C alleles (TT vs TC+CC) and acute rejection confirmed a significant association (odds ratio: 3.12; 95% CI: 0.01-9.83; P = .025). Haplotype CbG was higher in recipients without rejection as compared to rejection group (OR: 0.42, 95% CI: 0.16-1.13; P < .05). Respecting the endothelial nitric oxide synthase gene 894G/T single nucleotide polymorphisms and 27VNTR, no significant association between the allele/genotype and acute rejection was seen.

CONCLUSION

Recipient endothelial nitric oxide synthase gene polymorphisms do not alter the risk of acute rejection after a renal transplant. Rejection is a complex immunologic event. Therefore, finding associated genetic variants demands a multicentric larger sample size.

Association between the endothelial nitric oxide synthase gene Glu298Asp polymorphism and coronary heart disease: a meta‑analysis of 39 case‑control studies

Numerous studies have indicated that the human endothelial nitric oxide synthase (eNOS) gene Glu298Asp polymorphism is associated with coronary heart disease (CHD) susceptibility, however, their conclusions are inconsistent. The present meta‑analysis aimed to evaluate the precise result by searching the PubMed database and using 39 case‑control studies comprising 7489 cases and 7051 controls.Each study tested the association between the eNOS Glu298Asp polymorphism and CHD. A meta‑analysis was then conducted using the Comprehensive Meta Analysis 2.2 software to calculate the pooled odds ratios (ORs) of five genetic models with 95% confidence intervals (CIs). Publication bias was also explored. The meta‑analysis showed a significant association between the eNOS Glu298Asp polymorphism and CHD susceptibility for all the genetic models [Asp vs. Glu, OR 1.26, 95% CI 1.14‑1.40, P<0.001; Asp/Asp vs. Glu/Glu, OR 1.58, 95% CI 1.23‑2.02, P<0.001; Glu/Asp vs. Glu/Glu, OR 1.12, 95% CI 1.03‑1.22, P=0.001; (Glu/Asp+Asp/Asp) vs. Glu/Glu, OR 1.17, 95% CI 1.07‑1.27, P<0.001; Asp/Asp vs. (Glu/Glu+Glu/Asp), OR 1.59, 95% CI 1.25‑2.03, P<0.001]. Subgroup and sensitivity analyses indicated that the result was robust. A weak publication bias was detected. The results indicated that the eNOS Glu298Asp polymorphism is a risk factor for developing CHD, particularly in the Asian population.

Association of endothelial nitric oxide synthase gene polymorphisms with classical risk factors in development of premature coronary artery disease

Genetic polymorphism of the endothelial nitric oxide synthase (eNOS) affects the pathogenesis of atherosclerosis and associated with premature coronary artery disease (PCAD). We aimed to explore the association between Glu298Asp polymorphism of the eNOS gene and premature CAD in Egyptians, and the possible interaction between this polymorphism and other risk factors. The study population consisted of 116 patients with PCAD, and 119 controls. Glu298Asp polymorphism (rs1799983) of the eNOS gene was analyzed by polymerase chain reaction (PCR). We found that the TT genotype of the eNOS gene increased the risk of PCAD by 2.6. Hypertension, diabetes, smoking, total cholesterol, triglycerides, LDLc, HDLc and TT genotype of the eNOS gene were independent risk factors for the development of PCAD. We conclude that, the TT genotype of Glu298Asp polymorphism of eNOS gene is an independent risk factor of PCAD in Egyptians. The association of smoking, obesity, dyslipidemia and/or metabolic syndrome with the TT genotype increased the risk of the development of PCAD.

eNOS [Glu298Asp] polymorphism, erectile function and ocular pressure in type 2 diabetes

BACKGROUND

  Imbalance in nitric oxide (NO), an atheroprotective vasodilator, is associated with endothelial dysfunction, cardiovascular diseases (CVD) and diabetic complications. Various endothelial NO synthase (eNOS) polymorphisms may affect NO bioavailability, thereby promoting adverse cardiovascular milieu.

MATERIALS AND METHODS

  To analyze glucose homeostasis, cardiometabolic phenotype, and micro- and macroangiopathies associated with eNOS G894T gene polymorphism in type 2 diabetes (T2DM). 210 T2DM outpatients (mean age (1SD) 70 (12); diabetes duration 19 (9) years; males:females 64:36%; metabolic syndrome 87%) had insulin sensitivity and b-cell function modelled with HOMA, alongside routine laboratory and endothelin measurements.

RESULTS

  GG, GT and TT genotypes represented 48% (n = 100), 39% (n = 83) and 13% (n = 27). Overall microangiopathy (retinopathy, neuropathy and/or nephropathy) was present in 74%, and overall macroangiopathy (CAD, PAD and/or TIA/stroke) in 45%. The TT genotype did not translate into a more severe vascular phenotype, as TT patients carrying the proposed risk genotype did not suffer a higher rate of micro- and macrovascular complications. On the other hand, erectile dysfunction, present in 60% of males (n = 135), was much more prevalent in TT males: 57% [GG & GT] vs. 93% in TT (p 0.0088). Ocular hypertension/glaucoma frequency (18% of the whole group) was also markedly different, albeit in opposing directions, between eNOS G894T gene polymorphism subgroups: 21% [GG & GT] vs. 0% prevalence (TT; p 0.0057).

CONCLUSIONS

  eNOS G894T gene polymorphism in homozygous TT carriers translates into opposing effects on erectile function (detrimental) and ocular hypertension/glaucoma (protective) in T2DM, without affecting glucose homeostasis determinants or the presence of micro- and macrovascular complications.

Endothelial nitric oxide synthase Glu298Asp (G894T) gene polymorphism in coronary artery disease patients with type 2 diabetes mellitus

AIMS

Endothelial dysfunction is thought to be a significant risk factor for cardiovascular disease. This study determined the role of endothelial nitric oxide synthase (eNOS) Glu298Asp polymorphism and intergenotypic variation of plasma nitric oxide (NO) levels in coronary artery disease (CAD) patients with type 2 diabetes mellitus (DM).

METHODS

This case-control study included 28 documented CAD patients with type 2 DM and 32 non-diabetic patients with CAD. Fifty healthy volunteers without any major cardiovascular risk factors served as controls. NO was estimated by modified Griess method. The eNOS gene polymorphism was studied by amplifying DNA by PCR and digesting with BanII restriction enzyme. Restriction fragment length polymorphism was studied by using a gel documentation system.

RESULTS

The genotype frequencies for Glu298Asp (GT) genotype were 10.71% in diabetic CAD patients, 28.1% in non-diabetic CAD patients and 12% in controls. The T allele frequency was higher in the non-diabetic CAD group (14%) as compared with the diabetic CAD (5.4%) and control group (6%). NO level was significantly lower in non-diabetic CAD patients (10.25 mmol/L) but not in diabetic CAD patients (13.89 mmol/L) as compared to controls (16.78 mmol/L).

CONCLUSION

Glu298Asp polymorphism is not the mediator of increased incidence of CAD in diabetic patients.

Pharmacogenetic association of NOS3 variants with cardiovascular disease in patients with hypertension: the GenHAT study

Nitric oxide synthase 3 (NOS3) catalyzes production of NO in the endothelium and may play a role in cardiovascular disease (CVD). We assessed the pharmacogenetic associations of three NOS3 polymorphisms and three antihypertensive drugs with CVD outcomes. Hypertensive subjects (n = 30,280) from a multi-center, double-blind clinical trial were randomized to chlorthalidone, amlodipine, or lisinopril treatment (mean follow up, 4.9 years). Outcomes included coronary heart disease (CHD: fatal CHD and nonfatal myocardial infarction); stroke; heart failure (fatal, requiring hospitalization, or outpatient treatment); all-cause mortality; and end-stage renal disease (ESRD). Main effects of NOS3 variants on outcome and genotype-treatment interactions were tested. For NOS3 −690 C>T (rs3918226), a higher hazard ratio (HR) was found in minor allele carriers for CHD (CC = 1.00, CT+TT = 1.12 (95% confidence interval (CI) = 1.00–1.26), P = 0.048). For NOS3 −922 A>G (rs1800779), a higher HR was found in minor allele carriers for heart failure (AA = 1.00, AG+GG = 1.10 (CI = 1.00–1.21), P = 0.046). Significant pharmacogenetic findings were observed for stroke and all-cause mortality. For −690 C>T, a lower HR was observed for stroke in minor allele carriers when treated with amlodipine versus lisinopril (CC = 0.85 (CI = 0.73–0.99), CT+TT = 0.49 (CI = 0.31–0.80), P = 0.04). For glu298asp G>T (rs1799983), a lower HR was observed for all-cause mortality in minor allele carriers when treated with amlodipine versus lisinopril (GG = 1.01 (CI = 0.91–1.13), GT+TT = 0.85 (CI = 0.75–0.97), P = 0.04). We observed significant associations with NOS3 variants and CHD and heart failure and significant pharmacogenetic effects for stroke and all cause mortality. This suggests that NOS3 variants may potentially provide useful clinical information with respect to treatment decisions in the future.

The G894T polymorphism on endothelial nitric oxide synthase gene is associated with increased coronary heart disease among Asia population: evidence from a Meta analysis

INTRODUCTION

Growing studies have revealed the underlying association between eNOS 894G/T (rs1799983) polymorphism and coronary heart disease (CHD) among Asia population. Results from these studies remained conflicting. We conducted this meta-analysis to estimate the overall CHD risk of eNOS 894G/T polymorphism regarding Asia population.

MATERIALS AND METHODS

Up to October 2011, databases including PubMed, Embase and CNKI (China National Knowledge Infrastructure) were searched to access the relevant genetic association studies. Summary odds ratios and corresponding 95% confidence intervals (CIs) for eNOS 894G/T polymorphism and CHD risk were estimated using fixed or random-effects models when appropriate.

RESULTS

18 case-control studies with 2,994 cases and 3,130 controls were available for this study, including 13 studies of East-Asia descendents, 5 studies of Non East-Asian descendents. The mean T allele frequency was 0.111 in the East-Asia population and 0.147 in the Non East-Asia population, respectively. The summary OR for CHD associated with the T allele was 1.52 (95% confidence intervals (95%CI), 1.37-1.69) by random effects model. Similarly, significantly increased risks were observed in the East-Asia population (OR=1.54; 95%CI=1.35-1.76) and in the Non East-Asia population (OR=1.48; 95%CI=1.24-1.77), respectively.

CONCLUSIONS

This meta-analysis indicated that eNOS 894G/T polymorphism may play an important role in CHD development among Asia population.

Association of Endothelial Nitric Oxide Synthase Gene Variant (G894T) With Coronary Artery Disease in Western Iran

There are conflicting reports about the association of endothelial nitric oxide synthase (eNOS) gene polymorphism and the risk of coronary artery disease (CAD). To determine the frequency of eNOS G894T variant and to find the possible association between this polymorphism with CAD we studied 207 unrelated patients with total CAD (with and without diabetes) and 92 controls. The eNOS variants were detected by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP). The presence of GT + TT genotype was associated with 2.1-fold ( P = .006), 2.29-fold ( P = .006), and 1.93-fold ( P = .032) increased risk of CAD in total CAD, CAD with diabetes, and in CAD without diabetes patients, respectively. The presence of T allele of eNOS increased the risk of CAD 2.15-fold ( P = .001). The levels of low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) tended to be higher in patients carrier for T allele compared to those with G allele. The results of present study revealed that eNOS G894T polymorphism is associated with increased risk of CAD in our population.

Lack of association between Glu298Asp polymorphism and coronary artery disease in North Indians

Nitric Oxide (NO) is an important molecule carrying number of different functions in humans. Published studies suggest that it may inhibit several key steps involved in the pathogenesis of atherosclerosis. Inhibition or reduction of NO due to Glu298Asp polymorphism may accelerate atherosclerosis. The aim of this study was to determine whether Glu298Asp polymorphism is implicated in the pathogenesis of coronary artery disease (CAD) among North Indian population from the state of Uttar Pradesh, India. We selected 253 CAD patients and 174 healthy, normotensive, non-diabetic controls, which were matched for gender and ethnicity. The Glu298Asp (rs1799983) variant was detected by genotyping subjects, using a polymerase chain reaction followed by restriction fragment length polymorphism. There was no significant difference found in the genotypic and allelic frequencies between patients and controls. Our study indicated that Glu298Asp polymorphism does not play any critical role in the pathogenesis of CAD, at least in North Indian population.

The 894G > T (Glu298Asp) variant in the endothelial NOS gene and MTHFR polymorphisms influence homocysteine levels in patients with cognitive decline

The presence and severity of cerebrovascular pathological findings have been shown to increase the risk and stage of cognitive decline observed in Alzheimer's disease and vascular dementia. Thus, the modification of vascular risk factors seems useful to reduce the risk of dementia regardless of type. Hyperhomocysteinemia has long been known as a major independent risk factor for vascular dysfunction. In this study, we evaluated the relationships between plasma homocysteine levels and genetic risk factors for hyperhomocysteinemia, i.e., the presence of gene variants for methylenetetrahydrofolate reductase (MTHFR) and endothelial nitric oxide synthase (eNOS) in patients with cognitive impairment. Genotyping for MTHFR C677T and eNOS 894G > T polymorphisms was carried out in 69 patients with probable diagnosis of AD and anamnestic mild cognitive impairment, matched for age and gender with 69 healthy volunteers. Patients with MTHFR TT677 genotype showed higher plasma Hcy levels than controls, even after adjustment for folate levels (P < 0.05). Moreover, Hcy plasma levels were higher in cases than controls for any given eNOS genotype. In particular, the presence of eNOS TT894 genotype in patients with cognitive decline resulted significantly associated with increased plasma Hcy levels when compared with controls having the same genotype or patients having other eNOS genotypes (P = 0.02). These data suggest that both MTHFR C677T and eNOS G894T variants should be regarded as genetic risk factors for hyperhomocysteinemia in patients with cognitive decline.

Prevalence of endothelial nitric oxide synthase (eNOS) gene exon 7 Glu298Asp variant in North Eastern India

BACKGROUND & OBJECTIVES

Endothelial nitric oxide is a potent vasodilator and impairment of its generation brought about by gene polymorphism is considered a major predictor for several diseases. A single nucleotide polymorphism G894T within exon 7 of endothelial nitric oxide synthase (eNOS-7) gene, resulting in a replacement of glutamic acid by aspartic acid, has been studied as a putative candidate gene for cardiovascular diseases. The pattern of eNOS-7 Glu298Asp variant in the Indian population is poorly known. The present study was planned to determine the prevalence of the variant of this gene among tea garden community in Assam, North-East India with high prevalence of hypertension.

METHODS

Study participants of both sex aged ≥18 yr were recruited randomly from temporary field clinics established in tea gardens of Dibrugarh, Assam. Genomic DNA was extracted from 409 subjects by the conventional phenol-chloroform method. The prevalence of the eNOS exon 7 Glu298Asp variant was determined by polymerase chain reaction and restriction fragment length polymorphism analysis.

RESULTS

The study population was in Hardy-Weinberg Equilibrium. The frequency of the eNOS GG, GT and TT genotypes was found to be 75, 22 and 3 per cent respectively and did not show any significant difference in gender wise analysis.

INTERPRETATION & CONCLUSIONS

Our results showed that the prevalence of the homozygous GG genotype was high (75%) and the rare mutant genotype (homozygous, TT) was 3 per cent in a population at risk with cardiovascular disease. Such population-based data on various polymorphisms can ultimately be exploited in pharmacogenomics.

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.

Role of Genetic Polymorphism of Angiotensin-Converting Enzyme, Plasminogen Activator Inhibitor-1 and Endothelial Nitric Oxide Synthase in the Prognosis of Coronary Artery Disease

Background

This study was to investigate the effects of multiple genetic polymorphisms and conventional risk factors in the prognosis of coronary artery disease (CAD).

Methods

One hundred and fifty five patients with CAD were prospectively recruited, they were subgrouped as single vessel disease (SVD) and multiple vessel disease (MVD). All patients were detected I/D polymorphism of angiotensin-converting enzyme (ACE) gene, 4G/5G polymorphism of plasminogen activator inhibitor-1 (PAI-1) gene, and G894→T mutation of endothelial nitric oxide synthase (eNOS) gene. The patients were followed up for 10-65 months, mean 35 months. End points were major adverse cardiovascular events (MACE), including angina, myocardial infarction, and cardiac sudden death.

Results

During the follow-up period, MACE developed in 81 patients, 73 patients with angina, seven with myocardial infarction, and one with cardiac sudden death. CAD patients with MVD were more probable of developing MACE during follow-up. Distribution of PAI-1 gene polymorphism was significantly different between SVD and MVD patients, p < 0.001. The frequency of DD genotype of ACE and 4G/4G genotype of PAI-1 in patients with MACE were significantly higher than those in patients without MACE, p < 0.001 and p = 0.002, respectively. Incidence of diabetes mellitus was significantly higher in patients with MACE than in patients without MACE, P = 0.03. Cox regression analysis showed that diabetes mellitus (HR 2.36, 95% CI 1.33-4.46, p = 0.003), 4G/4G polymorphism of PAI-1 gene (HR 3.45, 95% CI 1.71-6.56, p = 0.009), and D/D polymorphism of ACE gene (HR 2.99, 95% CI 1.84-5.76, p = 0.005), were independent predictors of the MACE.

Conclusions

Our results showed that the conventional risk factors and genetic polymorphisms have significant influence on prognosis of CAD patients. CAD patients with diabetes mellitus, DD genotype of ACE, and 4G/4G genotype of PAI-1 suggested poor prognosis.

Endothelial nitric oxide synthase and angiotensinogen gene polymorphism in coronary artery diseases in Egypt

Genetic factors contribute to the pathogenesis of coronary artery disease (CAD). We studied 100 patients with CAD and 50 healthy individuals to assess the association of endothelial nitric oxide (eNOS) polymorphism (Glu298Asp) and angiotensinogen polymorphisms (M235T) and CAD in an Egyptian population. Serum nitric oxide (NO) and angiotensin I levels were also measured. The frequency of Glu298Asp and M235T polymorphisms were higher in the CAD group compared with controls. The mean level of NO was significantly lower (P < .05) while angiotensin I was significantly higher (P < .05) in patients CAD than in controls. The frequency of eNOS TT allele of M235T variant was significantly higher in patients with CAD (20% vs 6%). The frequency of angiotensinogen (AGT) TT and T allele in patients with CAD was significantly higher (P < .05) than in controls (22% vs 6%and 47% vs23%, respectively). Homozygosity for Glu298Asp and M235T polymorphisms may predispose to CAD.