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

Apolipoprotein E E3/E4 genotype is associated with an increased risk of premature coronary artery disease

OBJECTIVE

Dyslipidemia is one of the causes of coronary heart disease (CAD), and apolipoprotein E (APOE) gene polymorphism affects lipid levels. However, the relationship between APOE gene polymorphisms and premature CAD (PCAD, male CAD patients with ≤ 55 years old and female with ≤ 65 years old) risk had different results in different studies. The aim of this study was to assess this relationship and to further evaluate the relationship between APOE gene polymorphisms and PCAD risk in the Hakka population.

METHODS

This study retrospectively analyzed 301 PCAD patients and 402 age matched controls without CAD. The APOE rs429358 and rs7412 polymorphisms were genotyped by polymerase chain reaction (PCR) -chip technique. The distribution of APOE genotypes and alleles between the case group and the control group was compared. The relationship between APOE genotypes and PCAD risk was obtained by logistic regression analysis.

RESULTS

The frequency of the APOE ɛ3/ɛ4 genotype (18.9% vs. 10.2%, p = 0.001) and ε4 allele (11.1% vs. 7.0%, p = 0.007) was higher in the PCAD patients than that in controls, respectively. PCAD patients with ɛ2 allele had higher TG level than those with ɛ3 allele, and controls carried ɛ2 allele had higher HDL-C level and lower LDL-C level than those carried ɛ3 allele. Regression logistic analysis showed that BMI ≥ 24.0 kg/m2 (BMI ≥ 24.0 kg/m2 vs. BMI 18.5-23.9 kg/m2, OR: 1.763, 95% CI: 1.235-2.516, p = 0.002), history of smoking (Yes vs. No, OR: 5.098, 95% CI: 2.910-8.930, p < 0.001), ɛ3/ɛ4 genotype (ɛ3/ɛ4 vs. ɛ3/ɛ3, OR: 2.203, 95% CI: 1.363-3.559, p = 0.001), ε4 allele (ε4 vs. ε3, OR: 2.125, 95% CI: 1.333-3.389, p = 0.002), and TC level (OR: 1.397, 95% CI: 1.023-1.910, p = 0.036) were associated with PCAD.

CONCLUSIONS

In summary, BMI ≥ 24.0 kg/m2, history of smoking, APOE ɛ3/ɛ4 genotype, and TC level were independent risk factors for PCAD. It means that young individuals who are overweight, have a history of smoking, and carried APOE ɛ3/ɛ4 genotype had increased risk of PCAD.

Association of Endothelial Nitric Oxide Synthase and Angiotensin-Converting Enzyme Genes Polymorphism With In-Sent Restenosis of Bare Metal Stents vs Drug-Eluting Stents in Egyptians

Despite its unequivocal superiority compared with balloon angioplasty, coronary stenting did not abolish restenosis. We aimed to evaluate the associations between a common single nucleotide polymorphism occurring in endothelial nitric oxide synthase (eNOS) and angiotensin-converting enzyme (ACE) genes and the risk of in-stent restenosis (ISR) of bare metal stents vs drug-eluting stents (BMS vs DES) implanted in Egyptian patients. Two hundred patients who had coronary stenting were divided into group I (n = 98) who received a BMS and group II (n = 102) who received a DES. eNOS and ACE genes polymorphism were analyzed by polymerase chain reaction (PCR). We found that the GA and AA genotypes of the eNOS gene were associated with the ISR with both BMS and DES. However, the ACE gene was not associated with ISR. We concluded that eNOS gene polymorphism is associated with ISR. Hypertension, stent length, and AA genotype of the eNOS gene were found to be independent predictors of the occurrence of ISR after both BMS and DES use.

Glu298Asp variant of the endothelial nitric oxide synthase gene and acute coronary syndrome or premature coronary artery disease: A systematic review and meta-analysis

INTRODUCTION

Several published studies have reported an association between the Glu298Asp polymorphism (rs1799983), residing in the endothelial nitric oxide synthase (NOS3) gene, and lower levels of circulating nitric oxide, as well as an increased risk of coronary artery disease (CAD). However, association status of this genetic variant with acute coronary syndrome (ACS) or premature CAD (PCAD) is still unclear. Against this background, we conducted a systematic review and study level meta-analysis to assess the association of the NOS3 Glu298Asp polymorphism with ACS or PCAD.

MATERIALS AND METHODS

A comprehensive online search to identify relevant studies was performed on several databases including PubMed, EMBASE, MEDLINE, Scopus, Cochrane library and Web of Science. The identified studies were stratified into two ancestral subgroups: 'European ancestry' and 'All other ancestries combined'. Study level odds ratios (ORs) and their 95% confidence intervals (CI) were pooled using random/fixed effects employing a Z test.

RESULTS

Out of a total of 195 distinct records identified through online search, 37 articles with 39 different studies, with a total sample size of 27,441 (11,516 cases/15,925 controls) were included for quantitative synthesis. Pooled results suggested significant associations of the NOS3 Glu298Asp polymorphism with ACS or PCAD through dominant as well as allelic genetic models (p ≤ 0.002), primarily driven by the 'All other ancestries combined' subgroup. The 'All other ancestries combined' subgroup demonstrated an additional risk of 36% for ACS or PCAD, through both dominant and allelic genetic models (OR = 1.36, 95%CI = 1.13, 1.63, p = 0.001 and OR = 1.36, 95%CI = 1.14, 1.61, p = 0.0005 respectively). On the other hand, the 'European ancestry' subgroup did not show any significant associations. Sensitivity analysis and a sub-analysis for the myocardial infarction endpoint further supported these observed associations.

CONCLUSIONS

This meta-analysis indicates towards an association between the NOS3 Glu298Asp polymorphism and ACS or PCAD, predominantly driven by 'All other ancestries combined' subgroup. In contrast, the 'European ancestry' subgroup did not demonstrate any significant association. Further large-scale investigations are required to confirm our derived results.

Association of endothelial nitric oxide synthase (Glu298Asp) gene polymorphism with radial artery spasm during cardiac catheterization in Egyptians

BACKGROUND

Nitric oxide (NO) exerts diverse effects on the cardiovascular system. Impairment of NO production plays a key role in cerebral and coronary artery spasm. We aimed to explore the predicting factors of radial artery spasm (RAS) and the association of eNOS gene polymorphism (Glu298Asp) with RAS during cardiac catheterization.

METHODS AND RESULTS

200 patients underwent elective coronary angiography through a trans-radial approach. The subjects were genotyped to the Glu298Asp polymorphism (rs1799983) on the eNOS gene by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Our results showed that the subjects with the TT genotype and T allele were significantly more likely to develop radial artery spasms (OR = 12.5, 4.6, P < 0.001 respectively). TT genotype of eNOS Glu298Asp polymorphism, number of punctures, size of the radial sheath, radial tortuosity, and right radial access are independent predictors of radial spasm.

CONCLUSION

The eNOS (Glu298Asp) gene polymorphism is associated with RAS during cardiac catheterization in Egyptians. TT genotype of eNOS Glu298Asp polymorphism, number of punctures, size of the radial sheath, right radial access, and tortuosity are independent predictors of RAS during cardiac catheterization.

Association of polymorphisms of renin angiotensin system and endothelial nitric oxide synthase genes with premature cardiovascular disease in an Iranian population

INTRODUCTION

The study of polymorphisms and their relationship with diseases is very important for risk assessment. The aim of this study was to determine the relationship between early risk of coronary artery disease(CAD) with renin-angiotensin(RAS) genes and endothelial nitric oxide synthase(eNOS) in a sample of the Iranian population.

METHODS & MATERIALS

In this cross-sectional study, 63 patients with premature CAD and 72 healthy samples were enrolled. Polymorphism of the promotor region of eNOS- and ACE-I/D (Angiotensin Converting Enzyme-I/D) polymorphism was evaluated. Polymerase chain reaction (PCR) test and PCR-RFLP (Restriction Fragment Length Polymorphism) was performed for ACE and eNOS-786 gene, respectively.

RESULTS

The frequency of deletion(D) for the ACE gene was significantly higher in patients(96% versus 61%; P < 0.001). Conversely, the number of defective C alleles for the eNOS gene was similar in both groups (p > 0.9).

CONCLUSION

ACE polymorphism seems to be an independent risk factor for premature CAD.

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.

Association between endothelial nitric oxide synthase and the renin-angiotensin-aldosterone system polymorphisms, blood pressure and training status in normotensive/pre-hypertension and hypertensive older adults: a pilot study

Introduction:Variations in blood pressure (BP) are, in part, genetically determined and some polymorphisms of renin-angiotensin- aldosterone system (RAAS) and synthase of endothelial nitric oxide (eNOS) have been related to hypertension (HT). Conversely, physical exercise is considered a non-pharmacological tool for HT control, treatment, and prevention.Objective: The purpose of this study is to investigate the relationship between eNOS and RAAS polymorphisms, their epistatic interaction, and the respective humoral factors in the BP control in normotensive/pre-hypertension and hypertensive older adults and how this relationship can be modulated by training status (TS) level.Methods:A total of 155 older adults (66.94 ± 6.83 years old) performed the following evaluations: AAHPERD battery test to determine the general functional fitness index (GFFI), systolic and diastolic blood pressure (SBP and DBP), blood collection for DNA extraction, analysis of eNOS gene polymorphisms rs2070744; rs61722009 and rs1799983 and RAAS polymorphisms rs699; rs1799752 and rs5186, and quantification of ACE activity (Fluorimetric Assay) and nitrite concentration (Chemiluminescence Method).Results and Conclusion:Good TS level appears to exert greater influence on SBP for G2 and G3 (G1: 125.79 ± 14.03/ G2: 119.91 ± 11.72^/G3: 119.71 ± 10.85) and on NO₂ for G3 (G1: 0.42 ± 0.25/ G2: 0.54 ± 0.45/ G3: 0.71 ± 0.52). No associations were observed between eNOS and RAAS polymorphisms, but the epistasis was identified between eNOS polymorphism, rs2070744, and RAAS polymorphism, rs699, revealing a statistically significant interaction (p = .0235) with training score of 0.63, a training test accuracy of 0.61 and a cross-validation consistency of 10/10. This result suggests an increased risk of hypertension.

The incidence of NOS3 gene polymorphisms on newborns with large and small birth weight

The NOS3 gene polymorphisms T-786C, G894T and VNTR 4b/a are associated with a predisposition to the development of Metabolic Syndrome (MetS). The NOS3 gene contributes to a normal pregnancy and fetal development. According to their birthweight, newborns can be classified as: small (SGA), adequate (AGA) or large (LGA) for gestational age. The SGA and LGA present a higher risk of developing disorders related to MetS, both during childhood and adulthood. Therefore, the aim of this work is to relate the incidence of G894T, T-786C and VNTR 4b/a on SGA and LGA newborns and their mothers. 204 blood samples were collected from mothers (102) and the umbilical cords of 102 newborns (SGA = 12; AGA = 47; LGA = 43). The genotyping was performed through PCR-RFLP to evaluate presence of the G894T, T-786C and VNTR 4b/a polymorphisms. A significant difference was found between the groups of newborns in the genotypic frequency of T-786C, but without Hardy-Weinberg equilibrium. The VNTR 4b/a and the G894T polymorphisms showed no significance between the groups. The haplotype analysis showed that the SGA newborns presented the higher frequency of 4aGT (9.8%) and of the 4aTT combination (25.4%), while LGA newborns presented the higher frequency of the 4bTT haplotype (23%). Only the SGA newborns and their mothers presented the 4aTC haplotype. In conclusion, the NOS3 polymorphisms do not appear to be a factor to inadequate birth weight. However, the G894T and VNTR 4b/a polymorphisms, and the haplotype 4aTC, seem to influence the occurrence of SGA.

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.

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.

Associations of the NOS3 rs1799983 polymorphism with circulating nitric oxide and lipid levels: a systematic review and meta-analysis

BACKGROUND

Circulating nitric oxide (NO) and lipid levels are closely associated with coronary artery disease (CAD). It is unclear whether the rs1799983 polymorphism in endothelial nitric oxide synthase (NOS3) gene is associated with plasma levels of NO and lipids. This systematic review and meta-analysis (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) aimed to clarify the relationships between the rs1799983 polymorphism and plasma levels of NO and lipids.

METHODS

Sixteen studies (2702 subjects) and 59 studies (14 148 subjects) were identified for the association analyses for NO and lipids, respectively. Mean difference (MD) and 95% CI were used to estimate the effects of the rs1799983 polymorphism on plasma NO and lipid levels. The primary outcome variable was NO, and the secondary outcomes included triglycerides, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C).

RESULTS

Carriers of the T allele had lower levels of NO (MD -0.27 μmol/L, 95% CI -0.42 to -0.12 μmol/L, p<0.001) and HDL-C (MD -0.07 mmol/L, 95% CI -0.14 to -0.00 mmol/L, p=0.04), and higher levels of TC (MD 0.13 mmol/L, 95% CI 0.06 to 0.20 mmol/L, p<0.001) and LDL-C (MD 0.14 mmol/L, 95% CI 0.05 to 0.22 mmol/L, p=0.002) than the non-carriers. Triglyceride levels were comparable between the genotypes.

CONCLUSION

The association between the NOS3 rs1799983 polymorphism and CAD may be partly mediated by abnormal NO and lipid levels caused by the T allele.

Prevalence of endothelial nitric oxide synthase (ENOS) gene G894T polymorphism and its association with hypertension: a population-based study with Brazilian women

Introduction

Hypertension is one of the most prevalent diseases in the world, accounting for millions of deaths each year. The reduction in the concentration of nitric oxide (NO) produced by the catalysis of endothelial nitric oxide synthase (eNOS) is associated with higher blood pressure (BP) levels. This reduction might be because of genetic polymorphisms. This study investigated the prevalence of the eNOS gene G894T polymorphism in women from northeast Brazil and its association with hypertension.

Material and methods

This cross-sectional study included 810 women (aged 19–49 years). Sociodemographic, health, anthropometric, and BP data were collected. Hypertension was defined according to the following criteria: systolic BP ≥ 140 mm Hg, diastolic BP ≥ 90 mm Hg, the regular use of antihypertensive medication, or some combination thereof. Epithelial cells from the cheek mucosa were obtained for DNA extraction. Genotyping was performed via real-time PCR. The measure of association was the prevalence ratio (PR) and its 95% CI as calculated via Poisson regression.

Results

The frequencies of the GG, GT, and TT genotypes were 57.1%, 35.7%, and 7.2%, respectively. For each of these genotypes, the prevalence of hypertension in women was 17.9%, 23.6%, and 34.4%, respectively. Relative to the GG genotype, the PRs after adjusting for cofounding factors were 1.24 (95% CI: 0.95–1.61, p = 0.11) for GT and 1.76 (95% CI: 1.16–2.67, p < 0.01) for TT.

Conclusions

The T allele of the G894T polymorphisms is associated with hypertension in women. This may have implications for prevention and treatment.

Association of endothelial nitric oxide synthase (eNOS) gene polymorphisms and physical fitness levels with plasma nitrite concentrations and arterial blood pressure values in older adults

Endothelial nitric oxide synthase (eNOS) gene polymorphisms are associated with reduced eNOS activity and nitric oxide (NO) production leading to an increase in blood pressure (BP). Regular exercise is the main strategy to minimize the deleterious effects of polymorphisms. However, due to the differences that physical exercise can be performed, some controversial results are found. Therefore it seems reasonable to evaluate the training status (TS). Thus, this study aimed to investigate the association of eNOS gene haplotypes and different levels of TS on nitrite concentrations (NO2-) and BP values in older adult. 424 elderly performed the following assessments: General Functional Fitness Index (GFFI) to estimate TS, systolic and diastolic blood pressure (SBP and DBP), blood collection for analysis of NO2- and g.-786T>C, intron 4b/a (VNTR) and 894G>T polymorphisms. Multivariate logistic regression showed that NO2- was influenced by GFFI and 4b/4a Intron 4. Regarding BP, GFFI influenced SBP and DBP, and just intron 4 was associated with variations in DBP. It can be observed that GFFI affected the NO2-, SBP and DBP independently of haplotypes. Therefore, maintenance of good level of TS can overcome the negative influence of genetics factors (intron 4) by increasing NO2- concentration and decreasing BP values.

An association between the endothelial nitric oxide synthase gene G894T polymorphism and premature coronary artery disease: a meta-analysis

Previous epidemiological studies have suggested that genetic factors are more likely to influence the development of premature coronary artery disease (CAD) than disease in older patients. Several studies have evaluated the association between the G894T polymorphism located in an exon of endothelial nitric oxide synthase (eNOS) and the risk of premature CAD. However, the findings were inconsistent. Thus, we performed a meta-analysis to clarify the association; we conducted both overall and subgroup analyses. Odds ratios and 95% confidence interval were calculated to evaluate the association between the G894T polymorphism and the risk of premature CAD. Overall analysis revealed a significant association. Subgroup analysis in terms of ethnicity revealed a significant association, in all models evaluated, between the G894T polymorphism and susceptibility to premature CAD in mixed population. In contrast, no such association was evident in Caucasians and Asians. On further subgroup analysis based on the premature CAD subtypes, we found that the G894T polymorphism was correlated with premature myocardial infarction (MI) but not with premature CAD without MI. In conclusion, we confirmed that the eNOS G894T polymorphism is a risk factor for premature CAD, particularly in those suffering premature MI.

Mesenchymal Stem Cells with eNOS Over-Expression Enhance Cardiac Repair in Rats with Myocardial Infarction

PURPOSE

Transplantation of mesenchymal stem cells (MSCs) is a promising therapeutic option for patients with acute myocardial infarction.

METHODS

We show here that the ectopic overexpression of endothelial nitric oxide synthases (eNOS), an endothelial form of NOS, could enhance the ability of MSCs in treating ischemic heart damage after the occlusion of the coronary artery.

RESULTS

Adenoviral delivery of human eNOS gene into mouse bone marrow-derived MSCs (BM-MSCs) conferred resistance to oxygen glucose deprivation (OGD)-induced cell death in vitro, and elevated the bioavailability of nitric oxide when injected into the myocardium in vivo. In a rat model of acute myocardial infarction, the transplantation of eNOS-overexpressing BM-MSCs significantly reduced myocardial infarct size, corrected hemodynamic parameters and increased capillary density. We also found that the synergistic effects were consistently better than either treatment alone.

CONCLUSIONS

These findings reveal a positive role of elevated eNOS expression in cardiac repair, and suggest the combination of eNOS and MSC transplant therapy as a potential approach for treating myocardial infarction.

Association of endothelial nitric oxide synthase (eNOS) gene G894T polymorphism with hypertension risk and complications

This study evaluated the association of NOS3 polymorphisms with hypertension risk and complications. eNOS (G894T) SNP was performed by RT-PCR on 70 hypertensive patients (25 were hypertensive, 25 were hypertensive with CAD, and 20 were diabetic with hypertension) and 30 age- and gender-matched individuals. Lipid and glucose profile were assessed by standard colorimetric assay. Our results revealed that combination of (GT + TT) genotype and T allele significantly increases the risk of hypertension (OR = 3.86 and 4.33), respectively. Subgroup analysis showed significant association between CAD with eNOS (G894T) mutant genotype (P = 0.002) and allele frequency (P < 0.001). Moreover, the mutant homozygous and heterozygous eNOS genotype together were significantly associated with higher TC, LDLc, (P < 0.001), and TG (P = 0.001). Thus, hypercholesterolemia (P < 0.001 and OR = 12.48) increases the risk of hypertension among T carrier. These results indicated that the T carriers significantly increase hypertension risk and complication (CAD), mainly with hypercholesterolemia and in elderly.

Endothelial nitric oxide synthase gene polymorphism is associated with Legg-Calvé-Perthes disease

The aim of this study was to assess the association of 27-bp variable number tandem repeat (VNTR) polymorphism in intron 4 and G894T polymorphism in exon 7 of the endothelial nitric oxide synthase (eNOS) gene with Legg-Calvé-Perthes disease (LCPD), and to provide a scientific basis for further research into the pathogenic mechanism. A total of 80 patients with LCPD and 100 healthy subjects were recruited in this case-control study. The 27-bp VNTR and G894T polymorphisms of the eNOS gene were genotyped using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism, respectively, followed by agarose gel electrophoresis and DNA sequencing. Allelic and genotypic frequencies were computed in the two groups and subjected to statistical analysis. For the 27-bp VNTR polymorphism, individuals with LCPD showed a higher frequency of the ab genotype [27.5 vs. 14%; odds ratio (OR), 2.33; 95% confidence interval (CI), 1.10-4.92; P=0.024]. For the G894T polymorphism, the LCPD case group showed a higher frequency of the heterozygous genotype GT than the healthy control group (35 vs. 17%; OR, 2.67; 95% CI, 1.33-5.36; P=0.005). The results indicate that these eNOS gene polymorphisms may be a risk factor for LCPD. The 27-bp VNTR polymorphism in intron 4 and G894T polymorphism in exon 7 may be involved in the etiology of LCPD.

Association of Polymorphisms in Endothelial Nitric Oxide Synthesis and Renin-Angiotensin-Aldosterone System with Developing of Coronary Artery Disease in Bulgarian Patients

AIM

The purpose of this study was to evaluate the association of common polymorphisms in endothelial nitric oxide synthesis (eNOS; G894T) and renin-angiotensin-aldosterone system (angiotensin converting enzyme [ACE]-I/D, angiotensinogen-T704C, and angiotensin II receptor type 1-A1166C) as risk factors in the pathogenesis of coronary artery disease (CAD) in Bulgarian patients.

METHODS

This study included 171 patients with CAD and 123 control subjects. Polymerase chain reaction-restriction fragment length polymorphism was used for studying the single-nucleotide polymorphisms. Statistical analysis was performed using statistical software PASW for Windows.

RESULTS

A significantly higher percentage of the eNOS T894 allele was found in patients with acute coronary syndrome (ACS), compared to controls (p = 0.006) and patients with stable angina pectoris (SAP, p = 0.005). Results from a binary regression analysis suggested that eNOS T allele and ACE D allele carriers were more likely to develop ACS than controls (T allele odds ratio [OR] 2.585, p = 0.024; D allele OR 3.585, p = 0.046) and patients with SAP (T allele OR 2.955, p = 0.009; D allele OR 2.703, p = 0.05). Exploratory evaluation of gene-gene combinations showed a significant association between eNOS-G894T/ACE-I/D and ACS compared to controls (p = 0.022) and patients with SAP (p = 0.017).

CONCLUSIONS

The eNOS G894T and ACE I/D polymorphisms are associated with an increased risk of developing ACS after adjusting for classical risk factors for atherosclerosis in the Bulgarian cohort.

Genetic Contributions to the Development of Complications in Preterm Newborns

Aim

We aimed to identify specific polymorphisms of genes encoding for vascular endothelial growth factor A (VEGFA), endothelial nitric oxide synthase (eNOS), renin-angiotensin system (angiotensinogen gene [AGT], angiotensinogen type 1 receptor [AGTR1], angiotensin-converting enzyme [ACE]), and heme oxygenase-1 (HMOX-1) in a cohort of preterm infants and correlate their presence with the development of respiratory distress syndrome (RDS) requiring mechanical ventilation (MV), bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH) and retinopathy of prematurity (ROP).

Study Design

We carried out a retrospective study to evaluate the allele frequency and genotype distribution of polymorphisms of VEGFA, eNOS, AGT, AGTR1, ACE, and HMOX-1 in a population of preterm neonates (n=342) with a gestational age ≤28 weeks according to the presence or absence of RDS requiring MV, BPD, IVH, or ROP. Moreover, we evaluated through the haplotype reconstruction analysis whether combinations of the selected polymorphisms are related to the occurrence of RDS, BPD, IVH and ROP.

Results

In our population 157 infants developed RDS requiring MV, 71 BPD, 70 IVH, and 43 ROP. We found that TC+CC rs2070744 eNOS (41.7 vs. 25.4%, p=0.01) and GT+TT rs1799983 eNOS (51.8 vs. 35.2%, p=0.01) polymorphisms are independent risk factors for BPD. Haplotype reconstruction showed that haplotypes in VEGF and eNOS are significantly associated with different effects on RDS, BPD, IVH, and ROP in our population.

Conclusions

We found that TC+CC rs2070744 eNOS and GT+TT rs1799983 eNOS polymorphisms are independent predictors of an increased risk of developing BPD. Haplotypes of VEGFA and eNOS may be independent protective or risk markers for prematurity complications.

Genetic association study of coronary collateral circulation in patients with coronary artery disease using 22 single nucleotide polymorphisms corresponding to 10 genes involved in postischemic neovascularization

BACKGROUND

Collateral growth in patients with coronary artery disease (CAD) is highly heterogeneous. Although multiple factors are thought to play a role in collateral development, the contribution of genetic factors to coronary collateral circulation (CCC) is largely unknown. The goal of this study was to assess whether functional single nucleotide polymorphisms (SNPs) in genes involved in vascular growth are associated with CCC.

METHODS

677 consecutive CAD patients were enrolled in the study and their CCC was assessed by the Rentrop method. 22 SNPs corresponding to 10 genes involved in postischemic neovascularization were genotyped and multivariate logistic regression models were adjusted using clinically relevant variables to estimate odds ratios and used to examine associations of allelic variants, genotypes and haplotypes with CCC.

RESULTS

Statistical analysis showed that the HIF1A rs11549465 and rs2057482; VEGFA rs2010963, rs1570360, rs699947, rs3025039 and rs833061; KDR rs1870377, rs2305948 and rs2071559; CCL2 rs1024611, rs1024610, rs2857657 and rs2857654; NOS3 rs1799983; ICAM1 rs5498 and rs3093030; TGFB1 rs1800469; CD53 rs6679497; POSTN rs3829365 and rs1028728; and LGALS2 rs7291467 polymorphisms, as well as their haplotype combinations, were not associated with CCC (p < 0.05).

CONCLUSIONS

We could not validate in our cohort the association of the NOS3 rs1799983, HIF1A rs11549465, VEGFA rs2010963 and rs699947, and LGALS2 rs7291467 variants with CCC reported by other authors. A validated SNP-based genome-wide association study is required to identify polymorphisms influencing CCC.

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.

Role of sGC-dependent NO signalling and myocardial infarction risk

The NO/cGMP pathway plays an important role in many physiological functions and pathophysiological conditions. In the last few years, several genetic and functional studies pointed to an underestimated role of this pathway in the development of atherosclerosis. Indeed, several genetic variants of key enzymes modulating the generation of NO and cGMP have been strongly associated with coronary artery disease and myocardial infarction risk. In this review, we aim to place the genomic findings on components of the NO/cGMP pathway, namely endothelial nitric oxide synthase, soluble guanylyl cyclase and phosphodiesterase 5A, in context of preventive and therapeutic strategies for treating atherosclerosis and its sequelae.

Influence of training status and eNOS haplotypes on plasma nitrite concentrations in normotensive older adults: a hypothesis-generating study

The purpose of this study was to evaluate the relationship between 3 eNOS gene polymorphisms and training status (TS) in affecting plasma nitrite concentration (NO2) in normotensive adults over 50 years old. Resting blood pressure (BP) was measured in all participants (n = 101). Plasma was taken to analyze: lipid profile, nitrite concentration (NO2) and lipid peroxide levels (T-BARS). Also, genomic DNA was extracted from plasma for genotyping NOS3 polymorphisms (-786T>C; 894G>T; and VNTR in intron 4). TS was determined by one-mile walk test and Functional Fitness Test Battery from AAHPERD (TS1-regular TS; TS2-good TS; and TS3-very good TS). BP was not influenced by TS, but NO2 was 15% higher in TS3 (123 ± 27 nM) compared to TS-2 (106 ± 22 nM). No differences were found in plasma NO2 in the haplotype analyses. However, the presence of the C allele (T-786C) and ASP allele (Glu298Asp) was found to enhance the correlation between TS and NO2 levels (r = 0.492 in C/4b/ASP haplotype and r = 0.855 in C/4a/ASP haplotype). This study thus identifies NOS3 polymorphism-dependent sensitivity to the effects of physical training on plasma NO2. Maintenance of good levels of training status, in carriers of C allele for T-786C polymorphism, combined with ASP allele for Glu298Asp polymorphism, may result in an increase in the NO2 plasma concentrations, which may reflect improved NO bioavailability in older adult normotensive individuals.

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.

Human C-reactive protein gene polymorphism and metabolic syndrome are associated with premature coronary artery disease

The aim of this study was to investigate the association between C-reactive protein (CRP) gene polymorphism and metabolic syndrome (MetS) with premature coronary artery disease (PCAD). 116 patients with PCAD (58 with MetS and 58 without MetS) and 119 controls were included in the study. CRP gene +1059 G>C polymorphism was analyzed by polymerase chain reaction. Serum hs-CRP was measured using high-sensitivity enzyme-linked immunosorbent assay. Carriers of C allele of the CRP +1059 G>C polymorphism had 3.37 fold increased risk to develop MetS in patients with PCAD. In addition CRP gene and hs-CRP levels were independent risk factors for PCAD and MetS. The present study provides new evidence that the presence of CRP +1059 G>C polymorphism and hs-CRP levels are independent determinants of PCAD and MetS in Egyptians. The results of our study suggest a synergistic effect of CRP C allele with classical risk factors such as hypertension, obesity, dyslipidemia and MetS.