Influence of endothelial nitric oxide synthase gene polymorphisms (−786T>C, 4a4b, 894G>T) in Korean patients with coronary artery disease

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.

Recent Updates and Advances in Winiwarter-Buerger Disease (Thromboangiitis Obliterans): Biomolecular Mechanisms, Diagnostics and Clinical Consequences

Thromboangiitis obliterans (TAO) or Buerger’s disease is a segmental inflammatory, thrombotic occlusive peripheral vascular disease with unknown aetiology that usually involves the medium and small-sized vessels of young male smokers. Due to its unknown aetiology and similarities with atherosclerosis and vasculitis, TAO diagnosis is still challenging. We aimed to review the status of biomolecular and laboratory para-clinical markers in TAO compared to atherosclerosis and vasculitis. We reported that, although some biomarkers might be common in TAO, atherosclerosis, and vasculitis, each disease occurs through a different pathway and, to our knowledge, there is no specific and definitive marker for differentiating TAO from atherosclerosis or vasculitis. Our review highlighted that pro-inflammatory and cell-mediated immunity cytokines, IL-33, HMGB1, neopterin, MMPs, ICAM1, complement components, fibrinogen, oxidative stress, NO levels, eNOS polymorphism, adrenalin and noradrenalin, lead, cadmium, and homocysteine are common markers. Nitric oxide, MPV, TLRs, MDA, ox-LDL, sST2, antioxidant system, autoantibodies, and type of infection are differential markers, whereas platelet and leukocyte count, haemoglobin, lipid profile, CRP, ESR, FBS, creatinine, d-dimer, hypercoagulation activity, as well as protein C and S are controversial markers. Finally, our study proposed diagnostic panels for laboratory differential diagnosis to be considered at first and in more advanced stages.

Gene polymorphisms in calcium-calmodulin pathway: Focus on cardiovascular disease

Cardiovascular disease is the leading cause of death in industrialized countries and affects an increasing number of people. Several risk factors play an important role in the etiology of this disease, such as an unhealthy lifestyle. It is increasingly clear that genetic factors influencing the molecular basis of excitation-contraction mechanisms in the heart could contribute to modify the individual's risk. Thanks to the progress that has been made in understanding calcium signaling in the heart, it is assumed that calmodulin can play a crucial role in the excitation-contraction coupling. In fact, calmodulin (CaM) binds calcium and consequently regulates calcium channels. Several works show how some polymorphic variants can be considered predisposing factors to complex pathologies. Therefore, we hypothesize that the identification of polymorphic variants of proteins involved in the CaM pathway could be important for understanding how genetic traits can influence predisposition to myocardial infarction. This review considers each pathway of the three different isoforms of calmodulin (CaM1; CaM2; CaM3) and focuses on some common proteins involved in the three pathways, with the aim of analyzing the polymorphisms studied in the literature and understanding if they are associated with cardiovascular disease.

Genetic association study between T-786C NOS3 polymorphism and essential hypertension in an Algerian population of the Oran city

BACKGROUND

Essential hypertension is an important risk factor for the development of cardiovascular disease. Important candidate genes such as NOS3 gene have been widely studied and reported to be associated with essential hypertension (HTN) in human populations.

AIM

We aim in this study to analyze the relationship between NOS3 -786T/C, a common genetic variant and HTN in a sample of the Algerian population of the Oran city.

METHODS

A case-control study has been performed in 154 subjects including 77 hypertensives and 77 normotensives. The recruitment of these subjects was done in local Health Centers of the city of Oran, West Algeria. HTN was defined as elevated systolic blood pressure SBD≥140  mmHg and or sustained diastolic blood pressure DBP≥90  mmHg, measured using an Omron^® Automatic BP Monitor - M-3W machine. Consents were obtained from all participants. Polymerase chain reaction (PCR) combined with restrictive fragment length polymorphism (RFLP) was used to genotype the NOS -786T/C variant.

RESULTS

The distribution of the allelic frequencies did not differ between cases and controls (OR = 1.48; 95%CI [0.94-2.32], P = 0.09). However, after adjustment with the age, sex, and body mass index, we observed significant association between NOS -786C allele and HTN status (OR = 2.08; 95%CI [1.18-3.66], P = 0.01).

CONCLUSION

Our results indicate that the C allele of the NOS3 gene is associated with increased risk of essential hypertension in this sample of the Algerian population of the Oran city. Further validation in larger samples is needed to confirm this finding.

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.

Association between eNOS Gene Polymorphism (T786C and VNTR) and Sickle Cell Disease Patients in Ghana

Endothelial nitric oxide synthase (eNOS) variants have been found to be associated with several vascular disorders as well as the pathogenesis of sickle cell disease (SCD) complications such as vaso-occlusive crises (VOC). Studies on eNOS gene variants among SCD patients are rare in Ghana and several other African countries. The current study aimed to determine a possible association between variants of the eNOS gene (variable number of tandem repeats in intron 4 and T786C) in SCD complications among Ghanaian patients. This was a cross-sectional study involving 89 HbSS patients with complications and 46 HbSS patients without complications. Genomic DNA was extracted from leukocytes in the buffy coat and separated from collected whole blood samples of the study participants. PCR amplification, followed by restriction fragment length polymorphism (RFLP) was used to genotype T786C (rs2070744) variants. Variable number of tandem repeats (VNTR) in intron 4 was genotyped by PCR and direct electrophoresis. There was a significant difference in the genotype frequency of the T786C variant between HbSS patients with complications and those without complications (p = 0.0165). However, there was no significant difference in the VNTR intron 4 variant of the eNOS gene between patients with complications and those without complications (p > 0.05). The study shows an association between the eNOS gene variant (T786C) and complications in SCD.

Cardiovascular Effects and Benefits of Exercise

It is widely accepted that regular physical activity is beneficial for cardiovascular health. Frequent exercise is robustly associated with a decrease in cardiovascular mortality as well as the risk of developing cardiovascular disease. Physically active individuals have lower blood pressure, higher insulin sensitivity, and a more favorable plasma lipoprotein profile. Animal models of exercise show that repeated physical activity suppresses atherogenesis and increases the availability of vasodilatory mediators such as nitric oxide. Exercise has also been found to have beneficial effects on the heart. Acutely, exercise increases cardiac output and blood pressure, but individuals adapted to exercise show lower resting heart rate and cardiac hypertrophy. Both cardiac and vascular changes have been linked to a variety of changes in tissue metabolism and signaling, although our understanding of the contribution of the underlying mechanisms remains incomplete. Even though moderate levels of exercise have been found to be consistently associated with a reduction in cardiovascular disease risk, there is evidence to suggest that continuously high levels of exercise (e.g., marathon running) could have detrimental effects on cardiovascular health. Nevertheless, a specific dose response relationship between the extent and duration of exercise and the reduction in cardiovascular disease risk and mortality remains unclear. Further studies are needed to identify the mechanisms that impart cardiovascular benefits of exercise in order to develop more effective exercise regimens, test the interaction of exercise with diet, and develop pharmacological interventions for those unwilling or unable to exercise.

Assessment of the role of plasma nitric oxide levels, T-786C genetic polymorphism, and gene expression levels of endothelial nitric oxide synthase in the development of coronary artery disease

Background:

Reduced bioavailability of nitric oxide (NO) and the T-786C polymorphism of endothelial nitric oxide synthase (eNOS) gene have been reported as risk factors for the development of coronary artery disease (CAD) with conflicting results. We investigated the association of plasma NO levels, T-786C genetic polymorphism, and gene expression levels of eNOS with CAD risk in an Iranian subpopulation.

Materials and Methods:

Studied population included 100 patients with angiographically verified CAD and 100 ethnically matched controls. Analysis of T-786C genetic polymorphism and gene expression levels of eNOS was conducted by polymerase chain reaction (PCR) restriction fragment length polymorphism and real-time reverse transcription-PCR methods, respectively. Plasma levels of NO were measured using Griess method.

Results:

The CC genotype distribution (15% vs. 6%, P = 0.011) and minor C allele frequency (36.5% vs. 21.5%, P = 0.001) of eNOS T-786C polymorphism differed significantly between CAD patients and control. Furthermore, eNOS T-786C polymorphism was more common among smoker than nonsmoker CAD patients (27.7% vs. 7.8%, P = 0.044). The association of the eNOS T-786C polymorphism with the severity of CAD (number of diseased vessel) was significant (P < 0.05). The gene expression levels of eNOS were significantly lower in the heterozygote (0.49 ± 0.1, P = 0.023) and mutant homozygote (0.36 ± 0.09, P = 0.011) genotypes than that of wild-type genotype (P < 0.05). In addition, NO levels were significantly lower in CAD patients compared with control subjects (42.62 ± 12.26 vs. 55.48 ± 16.57, P = 0.002) and showed intergenotypic variation in the CAD patients.

Conclusion:

Our study indicated that reduced NO levels and eNOS T-786C genetic polymorphism are significant risk factors for the development and severity of CAD in the Iranian population.

Association of the Endothelial Nitric Oxide Synthase Gene T786C Polymorphism with In-Stent Restenosis in Chinese Han Patients with Coronary Artery Disease Treated with Drug-Eluting Stent

Background and aim

Many studies have reported that genetic variants correlate with higher risk for coronary artery disease (CAD) or in-stent restenosis (ISR) after bare metal stent (BMS) implantation. However, there is limited data assessing the impact of these variants on ISR in patients treated with drug-eluting stent (DES). The purpose of this study was to investigate the effects of genetic risk factors on ISR in Chinese Han patients treated with DES.

Methods

A total of 425 patients with a diagnosis of CAD who underwent successful revascularization in native coronary arteries with DES were included in this retrospective study. Genotyping was performed on six single nucleotide polymorphisms (SNPs) in the endothelial nitric oxide synthase gene (eNOS), the angiotensin converting enzyme gene (ACE), the angiotensin II type 1 receptor gene (AT1R), the transforming growth factor beta gene (TGF-β), and the vascular endothelial growth factor gene (VEGF). Quantitative coronary angiography (QCA) was performed during the follow-up period to detect ISR. Logistic regression models were used to test for association.

Results

Fifty-four patients (12.7%) developed ISR during the follow-up period. Of the six analyzed SNPs, the frequency of the C allele of T786C polymorphism in eNOS was significantly higher in the ISR group (22.2%) compared to the non-ISR group (12.7%) (p<0.01). In the ISR group, the frequency of the TT, TC, and CC genotypes was 61.1%, 33.3%, and 5.6%, respectively, and in the non-ISR group, the frequencies were 76.8%, 21.0%, and 2.2%, respectively. The multivariable analysis adjusted for potential confounders and revealed that the T786C polymorphism increased the risk of ISR in both additive and dominant models with odds ratios of 1.870 (95% confidence interval [CI]: 1.079–3.240, p = 0.03) and 2.045 (95% CI: 1.056–3.958, p = 0.03), respectively.

Conclusion

The eNOS T786C polymorphism was associated with ISR in Chinese Han patients treated with DES. Genotyping may be helpful to identify patients with higher risks of ISR after DES implantation.

Endothelial nitric oxide gene polymorphisms and their association with coronary artery disease in Tunisian population

OBJECTIVE

By releasing mediators, like nitric oxide (NO), vascular endothelium is considered so significant in the process of atherosclerotic . In fact, the major functions of NO consist in inhibiting the activation of platelet, relaxing the muscles (vascular and smooth ones), and modulating the growth and the migration of cells (vascular and smooth ones). Therefore, this process makes the endothelial nitric oxide synthase (NOS3) considerably important because it possesses atheroprotective activity. Polymophisms, rs1808593 (10G/T) as well as rs891512 (G24943A) within NOS3 gene, play major role in the coronary artery disease (CAD) development. The aim of the study is to evaluate the relationship between the 10G/T and G24943A polymorphisms and the CAD among Tunisian individuals.

METHODS

We included, in this survey, a set of 274 patients suffering from CAD together with 162 normotensive subjects. The PCR-RFLP was applied to analyze the polymorphism of intron 23 (10G/T) gene, while the ASA-PCR was used to analyze the intronic G24943A gene polymorphism. Overall and subgroup analyses were performed. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association between NOS3 10G/T and G24943A polymorphisms as well as CAD risk. Statistical analysis was performed with SPSS V.10.

RESULTS

The genotype frequencies for G24943A polymorphism differed significantly between the CAD patients and the controls. The former had a frequency of 11.4% for the AA genotype, 34.7% for the GA genotype and 53.9% for the GG genotype. The latter had a frequency of only 2.5% for the AA genotype, 29.7% for the GA genotype and 67.7% for the GG genotype (χ2=7.62; OR=1.79; p=0.006). The CAD patient group showed a significantly-higher frequency of the A allele compared to the controls (0.28 vs. 0.16; χ2=15.20; p<0.001). The odds ratio of CAD for A vs. G allele frequency was statistically significant 1.99 (1.4-2.82) at 95% CI. The genotype distribution for the 3 investigated variants of 10G/T were not significantly different between CAD and control subjects (χ2=1.46; OR=1.72; p=0.22). Whereas, 10G/T has revealed barely allelic (χ2=4.45; OR=2.3; p=0.034) correlation with coronary artery disease Conclusion: The present study was designed so that there would be an association between the CAD and NOS3 polymorphism (G24943A). However, these results have proven that the polymorphism of 10G/T is not associated with CAD in the Tunisian population.

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.

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).

Endothelial nitric oxide synthase (eNOS) 4b/a gene polymorphisms and coronary artery disease: evidence from a meta-analysis

A variety of studies have suggested that the 4b/a polymorphism in the endothelial nitric oxide synthase (eNOS) was associated with coronary artery disease (CAD) risk. However, the data remain conflicting. The aim of the present meta-analysis was to estimate the overall association between risk of CAD and eNOS 4b/a polymorphism. Case-control, cohort or cross-sectional studies evaluating the association between eNOS 4b/a polymorphism and CAD susceptibility were systematically identified in PubMed up to 31 October 2013. Pooled odds ratios (OR) and corresponding 95% confidence intervals (CIs) were calculated to assess the association in overall and subgroup analyses. A total of 10,617 cases and 8302 controls from 37 studies were included in the study. The results of overall analysis revealed significant positive associations between CAD risk and eNOS 4b/a polymorphism in homozygote comparisons (OR = 1.47, 95% CI = 1.16–1.87), heterozygote comparisons (OR = 1.14, 95% CI = 1.02–1.27) and dominant models (OR = 1.18, 95% CI = 1.06–1.33). In subgroup analyses, similar associations were identified in African individuals, as determined using population-based source subgroups and noted in small-and-moderate sample size subgroups (case sample size or control sample size <500). The current meta-analysis revealed that eNOS 4b/a polymorphisms could be a risk factor for developing CAD, particularly in African populations and population-based subgroups.

The presence of the NOS3 gene polymorphism for intron 4 mitigates the beneficial effects of exercise training on ambulatory blood pressure monitoring in adults

The number of studies that have evaluated exercise training (ET) and nitric oxide synthase (NOS)3 gene polymorphisms is scarce. The present study was designed to evaluate the relationship between exercise training and NOS3 polymorphisms at -786T>C, 894G>T, and intron 4b/a on blood pressure (BP) using 24-h ambulatory BP monitoring (ABPM), nitrate/nitrite levels (NOx), and redox state. Eighty-six volunteers (51 ± 0.6 yr old) were genotyped into nonpolymorphic and polymorphic groups for each of the three positions of NOS3 polymorphisms. Auscultatory BP, ABPM, SOD activity, catalase activity, NOx levels, and malondialdehyde levels were measured. DNA was extracted from leukocytes, and PCR followed by sequencing was applied for genotype analysis. Aerobic ET consisted of 24 sessions for 3 days/wk for 40 min at moderate intensity. This study was performed in a double-blind and crossover format. ET was effective in lowering office BP (systolic BP: 3.2% and diastolic BP: 3%) as well as ABPM (systolic BP: 2% and diastolic BP: 1.3%). Increased SOD and catalase activity (42.6% and 15.1%, respectively) were also observed. The NOS3 polymorphism for intron 4 mitigated the beneficial effect of ET for systolic BP (nonpolymorphic group: -3.0% and polymorphic group: -0.6%) and diastolic BP (nonpolymorphic group: -3.2% and polymorphic group: -0.5%), but it was not associated with NOx level and redox state. Paradoxical responses were found for positions T786-C and G894T for the NOS3 gene. Consistently, the presence of the polymorphism for intron 4 blunted the beneficial effects of ET in middle-aged adults. Possibly, this effect might be as consequence of intron 4 acting as a short intronic repeat RNA controlling endothelial NOS activity epigenetically.

eNOSI4 and EPHX1 polymorphisms affect maternal susceptibility to preeclampsia: analysis of five polymorphisms predisposing to cardiovascular disease in 279 Caucasian and 241 African women

PURPOSE

The aim of this study was to evaluate possible associations of genetic polymorphisms predisposing to cardiovascular disease with the development and/or the severity of preeclampsia.

METHODS

A two hospital-based prospective case-control study was performed in Germany and Ghana. 470 blood samples of 250 Caucasian and 220 black African have been genotyped by pyrosequencing and fragment length analysis. We evaluated the distribution of the epoxide hydrolase 1 (EPHX1) polymorphism on exon 3, the endothelial nitric oxide synthase (eNOS) polymorphisms on exon 7 and on intron 4, the angiotensinogen polymorphism on exon 2 and the estrogen receptor 1 polymorphism in intron 1.

RESULTS

74 Caucasian and 84 African were classified as preeclampsia with 27 Caucasian developing a hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome and 17 African women experiencing eclampsia. Multivariate logistic regression analysis adjusting for ethnicity, age and parity revealed for carriers of eNOSI4 VNTR4a a 1.7-fold increased (95% CI 1.10-2.711, p = 0.016) risk to develop preeclampsia and a 3.6-fold increase for carriers of the EPHX1 113Tyr (95% CI 1.366-8.750, p = 0.009) to develop severest preeclampsia.

CONCLUSION

Our finding of eNOSI4 polymorphism predisposing to preeclampsia independently of ethnicity, age and parity supports the concept of NO being involved in the endothelial disorder preeclampsia. Since EPHX1 is highly expressed in the liver, can interact with various signaling pathways and is involved in central nervous system disorders, the association of EPHX1 polymorphism with the HELLP syndrome and eclampsia may hint to EPHX being a further key player in the pathogenesis of preeclampsia.

An intronic miRNA regulates expression of the human endothelial nitric oxide synthase gene and proliferation of endothelial cells by a mechanism related to the transcription factor SP-1

OBJECTIVE

This study was to investigate the molecular mechanisms underlying the 27nt-miRNA-mediated regulation of expression of the endothelial nitric oxide synthase (eNOS) gene.

METHODS

Cell lines overexpressing 27nt-miRNA or its mutant were established by transfecting the miRNA expression vector into the endothelial cells. eNOS mRNA and protein expression were examined by RT-PCR and Western Blotting, respectively. Luciferase activity reporter system was used to study the target of 27nt-miRNA.

RESULTS

The results showed that overexpression of 27nt-miRNA significantly inhibited eNOS mRNA level and protein expression, and reduced the eNOS transcriptional efficiency. Such inhibitory effects of 27nt-miRNA were attenuated by the sequence mutations in 27nt-miRNA. Interestingly, the transcription factor SP-1 expression was reduced by 27nt-miRNA. Meanwhile, overxpression of SP-1 protein partially restored eNOS expression, and rescued the 27nt-miRNA-mediated reduction of endothelial cell proliferation. Moreover, certain sites in the SP-1 mRNA were found to be the direct target of 27nt-miRNA by a luciferase reporter system.

CONCLUSIONS

These results demonstrate that the 27nt-miRNA suppresses eNOS gene expression and SP-1 expression in vascular endothelial cells. The 27nt-miRNA directly target to SP-1 mRNA, thereby contributing to proliferation of endothelial cells.

Association between endothelial nitric oxide synthase gene polymorphism (-786T>C) and interleukin-6 in acute coronary syndrome

Atherosclerosis is morphologically an inflammatory disease, where endothelial dysfunction plays a key role in all the stages. The nitric oxide (NO) synthase 3 (NOS3) gene is responsible for the synthesis of endothelial NO synthase (eNOS) in humans and some genetic polymorphisms are considered "polymorphisms associated with risk" for the development of coronary artery diseases, such as acute coronary syndrome. Thus, the present study aimed to evaluate the influence of the -786T>C polymorphism of the eNOS gene on inflammatory and oxidative process. A prospective cohort study of 125 consecutive patients with clinical diagnosis of non-ST-elevation acute coronary syndromes was conducted. Patients were assessed using a standardized questionnaire. Blood samples were drawn to measure serum levels of high-sensitivity C-reactive protein, soluble CD40 ligand, interleukin-6 (IL-6), N-terminal prohormone of brain natriuretic peptide, immunoglobulin G antibodies against oxidized low-density lipoprotein. The genotypes for the -786T>C polymorphism in the 5'-flanking region of eNOS gene were determined. The -786C allele was found in 92 of 250 alleles (38.8%). No statistical association was observed between demographic and clinical characteristics and distribution of eNOS-786T>C polymorphism. We found that -786CC was associated with lower levels of IL-6. No significant differences were observed between the distribution of -786T>C polymorphism and other investigated markers.

Endothelial nitric oxide synthase gene polymorphisms and the risk of osteonecrosis of the femoral head in systemic lupus erythematosus

PURPOSE

Nitric oxide (NO), a short-lived gaseous free radical, is a potent mediator of biological responses involved in the pathogenesis of autoimmune rheumatic diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Nitric oxide also serves as an important signal in physiological processes, including angiogenesis, thrombosis, and bone turnover, which are known to be related to the pathogenesis of osteonecrosis. We investigated whether NOS3 gene polymorphisms are associated with risk of osteonecrosis of the femoral head (ONFH).

METHODS

Five polymorphisms in the NOS3 gene were genotyped using TaqMan assays in 306 controls, 150 SLE patients, and 50 SLE patients with ONFH (SLE_ONFH).

RESULTS

We found that Asp258Asp and Glu298Asp (G894T) polymorphisms in the NOS3 gene were significantly associated with risk of ONFH. Additionally, we calculated haplotype frequencies of a linkage disequilibrium (LD) block in NOS3 (rs1799983 - rs1800780) and tested for haplotype associations. The haplotypes G-A and T-A showed significant protective (P = 1.6 × 10(-3); OR 0.39, 95 % confidence intervals (CI) 0.22-0.7) and increased risk (P = 2.0 x 10(-5)-6.0 x 10(-4); OR 3.17-3.73) effects for ONFH, respectively.

CONCLUSIONS

These results suggest that exonic NOS3 polymorphisms may increase the risk of ONFH in Korean SLE 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.

A tailed primers protocol to identify the association of eNOS gene variable number of tandem repeats polymorphism with ischemic stroke in Chinese Han population by capillary electrophoresis

Endothelial nitric oxide synthase (eNOS) plays an important role in mediating endothelium-dependent vasodilatation and antithrombotic action and is thus involved in the development of ischemic stroke (IS). Controversial results regarding the association of eNOS gene variable number of tandem repeats (VNTR) polymorphism with IS have been reported by conventional PCR-polyacrylamide gel electrophoresis methods. We aimed to identify any common association of eNOS gene VNTR polymorphism with IS in Chinese Han population by capillary electrophoresis (CE). The VNTR polymorphism of 27 bp within the eNOS intron-4 was determined by CE with specially designed tailed primers in Chinese Han patients with IS (n=457) and matched elderly controls without IS (n=457). Significant differences in BMI, WHR, hypertension, diabetes, smoking, TG, HDL, LDL, LDL, and FBG were observed between cases and controls. The distributions of eNOS VNTR polymorphism were not significantly associated with IS after adjustment for cardiovascular risk factors (OR=1.18, 95% CI: 0.82-1.69). This finding was consistent with the further meta-analysis in Asians. The meta-analysis in Americans demonstrated that 4a/4b+4a/4a genotype was significantly associated with IS risk with an OR of 1.54 (95% CI, 1.09-2.17) compared with the 4b/4b genotype. Our data suggests that BMI, WHR, hypertension, diabetes, smoking, TG, LDL, and FBG may increase the risk of IS. However, eNOS VNTR polymorphism may be not an independent major contributor for IS in Chinese Han population. The VNTR polymorphism might be associated with IS in Americans based on meta-analysis.

The Glu298Asp single nucleotide polymorphism in the endothelial nitric oxide synthase gene differentially affects the vascular response to acute consumption of fruit and vegetable puree based drinks

SCOPE

Diets low in fruits and vegetables (FV) are responsible for 2.7 million deaths from cardiovascular diseases (CVD) and certain cancers annually. Many FV and their juices contain flavonoids, some of which increase endothelial nitric oxide synthase (eNOS) activity. A single nucleotide polymorphism in the eNOS gene, where thymine (T) replaces guanine (G) at position 894 predicting substitution of glutamate for aspartate at codon 298 (Glu298Asp), has been associated with increased CVD risk due to effects on nitric oxide synthesis and subsequently vascular reactivity. Individuals can be homozygous for guanine (GG), thymine (TT) or heterozygous (GT).

METHODS AND RESULTS

We investigated the effects of acute ingestion of a FV-puree-based-drink (FVPD) on vasodilation and antioxidant status in subjects retrospectively genotyped for this polymorphism. Healthy volunteers (n = 24; 11 GG, 11 GT, 2 TT) aged 30-70 were recruited to a randomized, controlled, crossover, acute study. We showed that acute consumption of 400 mL FVPD differentially affected individuals depending on their genotype. There was a significant genotype interaction for endothelium-dependent vasodilation measured by laser Doppler imaging with iontophoresis (P < 0.05) and ex vivo low-density lipoproteins (LDL) oxidation (P = 0.002). GG subjects had increased endothelium-dependent vasodilation 180 min (P = 0.028) and reduced ex vivo LDL oxidation (P = 0.013) after 60 min after FVPD compared with control, no differences were observed in GT subjects.

CONCLUSION

eNOS Glu298Asp genotype differentially affects vasodilation and ex vivo LDL oxidation after consumption of FV in the form of a puree-based drink.

Association of plasma nitric oxide concentration and endothelial nitric oxide synthase T-786C gene polymorphism in coronary artery disease

Nitric oxide (NO) is synthesized from l-arginine by endothelium nitric oxide synthase (NOS3) and plays important roles in many physiologic and pathologic processes. NO involved in the pathogenesis of coronary atherosclerosis. In the present study we hypothesized that polymorphisms of NOS gene might be associated with increased risk of coronary artery disease (CAD) and plasma NO concentrations. The eNOS gene polymorphism was investigated in 241 unrelated CAD patients with positive coronary angiograms and 261 ages matched control subjects without a history of symptomatic CAD. The NOS3 gene polymorphisms were analyzed by RFLP. Plasma NO, lipid profile and other risk factors were also assessed. The genotype frequencies for T-786C polymorphism differed significantly between CAD patients and controls (p=0.041). The mean plasma NO(x) concentrations showed significant differences according to genotypes of T-786C polymorphism in total population only. The mean plasma NO(x) increased in those individuals that are homozygote for C allele in promoter compared with those individuals are heterozygote for this allele and homozygote for T allele in total population and Controls, but no in CAD patients. The present study provides evidences that T-786C polymorphism of the NOS3 gene is associated with CAD. T-786C polymorphism was not associated with increased plasma NO in CAD patients.

The relationships between endothelial nitric oxide synthase polymorphisms and the formation of intracranial aneurysms in the Korean population

OBJECT

Some genetic factors are known to be associated with the formation of cerebral aneurysms in the Caucasian population. One of these factors is endothelial nitric oxide synthase (eNOS) gene polymorphisms. Endothelial nitric oxide synthase genes encode eNOS, which synthesizes NO from l-arginine. There continues to be controversy about the relationships between eNOS gene polymorphisms and the formation of intracranial aneurysms. In this study, the authors evaluated these relationships in the Korean population.

METHODS

Three eNOS polymorphisms (eNOS 27VNTR, T786C, and G894T) were genotyped in 96 patients with ruptured aneurysms, 53 patients with unruptured aneurysms, and in 121 volunteers via polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

The mean ages of the patients and healthy volunteers were 52.9 ± 12.3 years and 55.2 ± 9.1 years, respectively. The patient group was composed of 56 men and 93 women, and the healthy volunteer group was composed of 46 men and 75 women. Only the incidence of smoking history was significantly higher in the patient group than in the control group (p = 0.001). The genotypic frequencies for the 3 eNOS gene polymorphisms were in agreement with those predicted by Hardy-Weinberg equilibrium. There were no significant associations between the eNOS recessive models and the formation of an aneurysm. The authors found no genotypic differences between similar races among patients with aneurysms.

CONCLUSIONS

The present study shows that eNOS 27VNTR, T786C, and G894T polymorphisms cannot be used as indicators of the formation of intracranial aneurysms in Korean patients. To confirm these findings an additional analyses might need to be performed using a larger sample size. There were no differences in the genotypic distributions and allelic frequencies between similar races among patients with aneurysms, which were the same in previously reported normal populations.

Interaction between endothelial nitric oxide synthase gene polymorphisms (-786T>C, 894G>T and intron 4 a/b) and cardiovascular risk factors in acute coronary syndromes

BACKGROUND AND AIMS

Endothelial rupture of coronary plaque can represent the pathomorphological substratum of acute coronary syndrome (ACS). Polymorphisms in the NOS3 gene (eNOS) -786T>C, 894G>T and intron 4 a/b VNTR can be associated with a higher susceptibility for ACS. The present study is focused on the investigation of the interaction of these polymorphisms and cardiovascular risk factors in 135 patients with ACS and 115 control subjects.

METHODS

Case-control study where the allele and genotype frequencies of the polymorphisms -786T> C, 894G> T and intron 4 VNTR of the gene encoding eNOS were determined by PCR-RFLP associated with cardiovascular risk factors.

RESULTS

An association of the 894TT genotype and 894GT+GG (OR 1.4; 95% CI 1.0-1.8) in ACS has been observed. Subjects without dyslipidemia and intron 4 a/b genotype present a lower chance for ACS development, whereas subjects without diabetes and 894TT genotype show a higher risk for ACS (OR 1.7; 95% CI 1.2-2.3). In patients without dyslipidemia, the 894GG genotype presented a tendency to behave as a protector factor against ACS. Also, the 894GG genotype has been a protective factor for ACS in females (OR 0.5; CI 95% 0.2-0.9).

CONCLUSIONS

Our results suggest that eNOS polymorphisms may be an additional risk factor in development of ACS.

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.

Endothelial nitric oxide synthase 894G→T but not -786T→C gene polymorphism is associated with organ dysfunction and increased mortality in patients with severe sepsis

BACKGROUND

Endothelial nitric oxide synthase (eNOS) -786T→C and 894G→T polymorphisms have been associated with eNOS dysfunction, which might further compromise microcirculatory blood flow during sepsis and increase the risk of organ injury. The purpose of this study is to investigate the association of those two eNOS gene polymorphisms with the severity of organ dysfunction and outcome in patients with severe sepsis.

METHODS

A cohort of patients with severe sepsis was studied and genotyped for eNOS -786T→C and 894G→T polymorphisms. Acute Physical and Chronic Health Evaluation score, the Sequential Organ Failure Assessment score, with or without shock, and the outcomes were compared in patients with different genotypes.

RESULTS

One hundred seventeen patients fulfilled with inclusion criteria were enrolled from nine intensive care units of academic hospital in Beijing. In comparison with the GG genotype, patients with the GT genotype (894G→T) had a trend toward an increase in the frequency of shock (87% vs. 68.1%, p=0.071) and significantly fewer days to shock onset (p<0.05). Those patients also had significantly higher Acute Physical and Chronic Health Evaluation II scores (p<0.05), Sequential Organ Failure Assessment scores (p<0.001), and mortality at both 7 days and 28 days (p<0.001). Multivariate analyses identified the GT genotype (894G→T) as an independent risk factor for outcome in patients with severe sepsis. However, we found that the eNOS -786T→C polymorphism was not associated with severity of disease or mortality of patients with sepsis.

CONCLUSIONS

Carriage of the GT genotype at 894 of eNOS gene was associated with the occurrence of shock and impaired organ function.

Age-specific eNOS polymorphisms in moyamoya disease

OBJECTIVE

We conducted a case-control study to investigate whether polymorphisms in eNOS are related to the age-specific onset of moyamoya disease.

MATERIALS AND METHODS

Ninety-three Korean patients [mean age, 23.0 ± 16.1 years; 59 female (63.4%) and 34 male (36.6%)] with moyamoya disease were consecutively recruited for this study. Three hundred twenty-eight healthy subjects [mean age, 27.7 ± 16.2 years; 217 female (66.2%), 111 male (33.8%)] were consecutively included in the control group. The subjects were divided into pediatric (< 20 years) and adult (≥ 20 years) groups. We further divided the moyamoya group into ischemic and hemorrhagic groups based on clinical and MRI findings. The frequencies and distributions of four eNOS polymorphisms (eNOS -922A>G, -786T>C, 4a4b, and 894G>T) were assessed in pediatric and adult patients with moyamoya disease and compared to the frequencies and distribution in the control group.

RESULTS

No differences in eNOS polymorphisms were observed between control and moyamoya disease group. However, we found that the 4a4b sequences was less frequent in the adult group (p = 0.029). Compared to the control group, there were differences in the haplotype distribution of the study group, specifically the A-4b-G haplotype, which was seen more frequently in the adult patient group.

CONCLUSION

Our results suggest that pediatric and adult-onset moyamoya disease have different genetic backgrounds. These genetic differences can affect age-specific clinical characteristics, such as cerebral ischemia and hemorrhage.

The 27-bp VNTR polymorphism in intron 4 of the human eNOS gene in healthy Singaporean Chinese, Indians, and Malays

Human endothelial nitric oxide synthase (eNOS) is one isoform of the nitric oxide synthases that are responsible for nitric oxide synthesis from L-arginine. The gene encoding eNOS contains a 27-bp VNTR polymorphism in intron 4. We report here for the first time the presence of a novel allele 3, which was absent in all other populations studied to date, in 1.7% each of Singaporean Indians and Malays. We also detected the presence of a novel genotype 3/5 in 3.4% each of Singaporean Indians and Malays. Allele 6, which was absent in Han Chinese from northern China and Taiwan and was also absent in Indians from the Indian subcontinent, was found in 2.1% of Singaporean Chinese and in 0.3% of Singaporean Indians.

Intronic microRNA suppresses endothelial nitric oxide synthase expression and endothelial cell proliferation via inhibition of STAT3 signaling

Intronic microRNA (miRNAs) suppressed the expression of endothelial nitric oxide synthase (eNOS) gene in endothelial cells (ECs). This study was to investigate the role of signal transducer and activator of transcription 3 (STAT3) in the regulation of eNOS expression and vascular EC proliferation by the intronic 27-nucleotide (nt) miRNA derived from the 27-base pair repeats in intron 4 of eNOS gene. A detectable level of the 27-nt miRNA was present in the control ECs. Overexpression of the 27-nt miRNA dramatically suppressed the expression of eNOS and STAT3 at both transcription and translation levels in ECs in association with significant inhibition of EC proliferation. Mutation of the 27-nt miRNA at the 3'-terminal region resulted in substantial reduction of the inhibitory effect of miRNA on eNOS and STAT3 expression, and EC proliferation. Overexpression of active STAT3 significantly reversed the inhibitory effect of the 27-nt miRNA on eNOS expression and EC proliferation. In summary, we demonstrated that the 27-nt intronic miRNA functioned as a negative regulator for the expression of its host gene eNOS and cell proliferation in ECs. The sequence in 3'-terminal region played a key role in the function of the 27-nt miRNA. The regulatory effect of the intronic miRNA on eNOS gene expression was associated with miRNA polymorphisms, and mediated through inhibition of STAT3 signaling in ECs.

Endothelial nitric oxide synthase gene polymorphisms -786T > C and 894G > T in coronary artery bypass graft surgery patients

Polymorphisms in the endothelial nitric oxide synthase (eNOS) gene (-786T >C and 894G >T) enhance endo-thelial dysfunction and have been studied in relation to coronary artery disease (CAD). In the present study, we examined the association of the above polymorphisms with CAD, as well as with myocardial infarction (MI), hypertension, diabetes and smoking in CAD patients. Study subjects consisted of 154 consecutive coronary artery bypass graft (CABG) patients and 155 non-CAD controls. eNOS -786T >C and 894G >T polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism. The estimated frequencies of the -786C and 894T alleles did not differ between the two groups (p = 0.46 and p = 0.84, respectively). The prevalence of eNOS polymorphisms was not associated with MI, hypertension or diabetes in CABG patients; however, we found that the 894TT genotype and 894T allele were significantly more frequent in current/past smoker CABG patients (16.7 per cent and 39.6 per cent, respectively) compared with never smoker CABG patients (6.1 per cent and 24.4 per cent, respectively) (p = 0.01 and p < 0.01, respectively). We found no association of eNOS -786C and 894T variant alleles with CAD; however, within CABG patients, a gene-environment interaction was found between the eNOS 894T allele and smoking.

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Association of the G894T polymorphism of the endothelial nitric oxide synthase gene with diabetic foot syndrome foot ulcer, diabetic complications, and comorbid vascular diseases: a Turkish case-control study

CONTEXT

There are controversial results and insufficient knowledge in the literature about the genetics of diabetes mellitus complications in the Turkish population and endothelial nitric oxide synthase (eNOS) gene polymorphisms may act as a potential modifier of diabetic vascular complications.

OBJECTIVE

The objective of this study was to determine the association between eNOS G894T polymorphisms and diabetes-related diseases.

DESIGN

A Turkish case-control study was designed.

SETTING

The study was carried out in the Ankara University Hospital.

PATIENTS OR OTHER PARTICIPANTS

Totally, 97 Turkish patients with diabetic foot ulcers and 102 controls were enrolled. Patients who had not received antimicrobial treatment in the preceding 6 months were included. Diabetic patients with hand and/or foot ulcers resulting from major trauma, such as road traffic accidents, were excluded.

MAIN OUTCOME MEASURE

The effect of eNOS gene polymorphisms on diabetic complications and comorbid diseases was measured.

RESULTS

Regarding eNOS G894T gene polymorphisms, 47.4% of the patients had GG (n = 46), 47.4% (n = 46) had GT, and 5.2% (n = 5) had TT alleles in the diabetes mellitus group, and 47.0% (n = 48), 41.2% (n = 42), and 11.8% (n = 12) had GG, GT, and TT alleles in the control group, respectively. There was no significant difference between the groups regarding the eNOS G894T gene allele ratios. Between groups with and without diabetic complications, a significant difference has only been found in the distribution of alleles in patients with comorbid atherosclerotic heart disease, whose GT-TT alleles were significantly higher than the GG alleles (p = 0.004).

CONCLUSION

G894T polymorphism of eNOS gene was not associated with foot ulcer and diabetic complications, except in the presence of atherosclerotic heart disease.

Effects of aerobic exercise on the blood pressure, oxidative stress and eNOS gene polymorphism in pre-hypertensive older people

The polymorphisms of endothelial nitric oxide synthase (eNOS) are associated with reduced eNOS activity. Aerobic exercise training (AEX) may influence resting nitric oxide (NO) production, oxidative stress and blood pressure. The purpose of this study was to investigate the effect of AEX on the relationship among blood pressure, eNOS gene polymorphism and oxidative stress in pre-hypertensive older people. 118 pre-hypertensive subjects (59 ± 6 years) had blood samples collected after a 12 h overnight fast for assessing plasma NO metabolites (NOx) assays, thiobarbituric acid reactive substances (T-BARS) and superoxide dismutase activity (ecSOD). eNOS polymorphism (T-786C and G-894T) was done by standard PCR methods. All people were divided according to the genotype results (G1: TT/GG, G2: TT/GT + TT, G3: TC + CC/GG, G4: TC + CC/GT + TT). All parameters were measured before and after 6 months of AEX (70% of VO(2 max)). At baseline, no difference was found in systolic and diastolic blood pressure, ecSOD and T-BARS activity. Plasma NOx levels were significantly different between G1 (19 ± 1 μM) and G4 (14.2 ± 0.6 μM) and between G2 (20.1 ± 1.7 μM) and G4 (14.2 ± 0.6 μM). Therefore, reduced NOx concentration in G4 group occurred only when the polymorphisms were associated, suggesting that these results are more related to genetic factors than NO-scavenging effect. After AEX, the G4 increased NOx values (17.2 ± 1.2 μM) and decreased blood pressure. G1, G3 and G4 decreased T-BARS levels. These results suggest the AEX can modulate the NOx concentration, eNOS activity and the relationship among eNOS gene polymorphism, oxidative stress and blood pressure especially in C (T-786C) and T (G-894T) allele carriers.

Association of endothelial nitric oxide synthase polymorphisms with coronary artery disease in Korean individuals with or without diabetes mellitus

Polymorphisms of the endothelial nitric oxide synthase (eNOS) gene have been implicated in various diseases, but their roles as risk factors in type 2 diabetes mellitus (T2DM) with regard to coronary artery disease (CAD) are largely unknown. Therefore, we investigated the association of the genotypes and haplotypes of eNOS polymorphisms in CAD with T2DM. A case-control study was performed to evaluate the genotypes and haplotypes of the eNOS polymorphisms (-786T>C, 4a4b and 894G>T) in 192 CAD patients and 196 controls. The same population was also re-organized upon the status of T2DM. The genotypes of eNOS -786T>C, 4a4b and 894G>T polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism. We found that eNOS -786TC+CC and 4a4b+4a4a genotypes were significantly prevalent in the diabetic controls and the diabetic CAD patients compared to the non-diabetic controls or non-diabetic CAD patients, respectively. The frequency of the -786C-4a-894G haplotype was significantly greater in the diabetic CAD patients (p=0.001) and diabetic controls (p=0.023) compared to the non-diabetic controls, whereas the haplotype of -786T-4b-894G was less prevalent in the diabetic CAD patients compared to the non-diabetic controls (p=0.018). Significant associations of the genotypes and the haplotypes were consistently observed in the T2DM group compared to non-DM group, regardless of CAD status. Our finding suggests that the eNOS -786T>C and 4a4b polymorphisms and the -786C-4a-894G haplotype are risk factors for T2DM, whereas the haplotype of -786T-4b-894G has a protective effect against the development of T2DM.