NOS3 Genotypes Research Articles

Cardiohemodynamic responses and heart rate variability following an active orthostatic test among male residents of the North with different NOS3 (rs2070744) genotypes

AIM: This study explored associations between the -786TC (rs2070744) genetic polymorphism of the NOS3 gene and the main indices of systemic hemodynamics and heart rate variability following an active orthostatic test in men living in the North. MATERIAL AND METHODS: Eighty-three healthy men aged 33.5±1.5 yеаrs on average, who were permanent residents of the Magadan Region, comprised the sample. The participants underwent both resting and active orthostatic testing modes. Cardiovascular system variables were recorded using an automatic tonometer. Hemodynamic indices were then calculated. Short-term heart rate variability in frequency and spectral areas was simultaneously measured using the Varikard hardsoft complex unit. Genotyping was conducted using polymerase chain reaction. The sample was then divided into two groups: Group 1 consisted of homozygotes with the TT genotype (n=34), while Group 2 comprised carriers of the NOS3*C allele variant (genotypes TC+CC) associated with reduced nitric oxide production (n=49). RESULTS: By examining the complex vasomotor, chrono- and inotropic reactions of hemodynamic and heart rate variables during the active orthostatic test, we were able to discern unique patterns in the response of the two groups under study. Men in Group 1 demonstrated an elevated cardiac output response during orthostatic changes, while maintaining consistent vascular resistance values. This was accompanied by a shift towards sympathetic autonomic activity and an increase in the very low-frequency component of heart rate variability. In Group 2, individuals with sympathetic insufficiency and increased vascular resistance during the orthostatic test showed a 35% increase in the low-frequency component of the cardiac rhythm reflecting the importance of this indicator as a stimulator of blood pressure rhythm fluctuations mediated by baroreflex mechanisms. CONCLUSION: Our findings suggest that men lacking the NOS3*С allele variant in their genotype demonstrate more favorable responses to the active orthostatic test. This may reflect higher level of cardiovascular functional reserves. The 786TC (rs2070744) polymorphism of the NOS3 gene can be considered as a marker of cardiohemodynamic status and autonomic regulations during functional exercise, such as an active orthostatic test.

Gene Polymorphism and Total Genetic Score in Martial Arts Athletes with Different Athletic Qualifications.

The personalized approach in sports genetics implies considering the allelic variants of genes in polymorphic loci when adjusting the training process of athletes. The personalized approach is used both in sports genetics and in medicine to identify the influence of genotype on the manifestations of human physical qualities that allow to achieve high sports results or to assess the impact of genotype on the development and course of diseases. The impact of genes of the renin-angiotensin and kinin-bradykinin systems in the development of cardiovascular disease in athletes has not been defined. This study aims to determine the polymorphisms of four genes (ACE, BDKRB2, PPARGC1A and NOS3) and the total genetic score to reveal the predisposition to the formation of physical qualities in martial arts athletes with different athletic abilities. The products of these four genes are involved in the control of blood pressure. The allelic variants of these genes are associated with the development of the physical quality “endurance” and have an indirect influence on the formation of speed and power qualities. The total genetic score (TGS: from 0 to 100 arbitrary units) was calculated from the genotype score in each polymorphism. The athletes were divided into Group I with high and Group II with low qualifications depending on their sports success. Single nucleotide polymorphisms (SNPs) are identified through restriction endonucleases cleavage for PCR amplicons for discriminating between alleles of the target genes ACE (rs4646994), BDKRB2 (rs5810761), PPARGC1A (rs8192673) and NOS3 (rs1799983). Significant differences between the allelic variants of target genes and athletic ability were found between Group I and Group II for genotype G/G of NOS3 gene and genotypes Gly/Gly and Gly/Ser of PPARGC1A gene. The data obtained confirm that athletes with unfavourable genotypes are excluded in the screening phase because their endurance is not fully developed to the required level in martial arts. Martial arts athletes with the highest TGS have the highest skill level. Polymorphic loci of four genes whose products are involved in blood pressure control (ACE, BDKRB2, NOS3 and PPARGC1A) can be used in martial arts not only to determine predisposition to cardiovascular disease but also to predispose to the development of speed and power qualities and endurance. The total genetic score can serve as a tool for predicting athletic success.

Endothelial NO synthase 786T/T polymorphism increases hemorrhagic transformation after endovascular thrombectomy

Background and purposeThis study examined whether the 786 NOS3 polymorphism is associated with the risk of hemorrhagic transformation (HT) in stroke patients with anterior large vessel occlusion (ALVO) treated using endovascular thrombectomy (EVT). MethodsWe performed an observational cohort study that included 118 patients with ALVO who underwent EVT. HT was assessed in follow-up CT and MRI. HT and non-HT patients were compared in terms of the 786 NOS3 polymorphism, flow mediated dilation (FMD) values within 3 days after the stroke, and collateral status based on three grading scales. Demographics, vascular risk factors, additional radiological data including ASPECT score, thrombus length and infarct size, and EVT procedure and outcome variables were also included. ResultsRadiological HT occurred in 55 (46.6%) patients and the 786T/T NOS3 polymorphism was associated with HT (unadjusted OR of 2.33, 95%CI: 1.05–5.20, adjusted OR of 3.14, 95%CI: 1.16–8.54). Collateral status and systemic endothelial function assessed by FMD were not mediators of this relationship as no differences were seen in the median FMD percentage values or collateral status between NOS3 genotypes. ConclusionsOur results suggest that genetic variations affecting the NO pathway, such as the 786 NOS3 polymorphism, may contribute to individual variability in the occurrence of HT and these results support involvement of this pathway in the pathogenesis of ischemia-reperfusion injury after EVT.

Layer-specific Nos3 expression and genotypic distribution in bicuspid aortic valve aortopathy.

We hypothesized that expression and activity of nitric oxide synthase-3 enzyme (Nos3) in bicuspid aortic valve (BAV) aortopathy are related to tissue layer and Nos3 genotype. Gene expression of Nos3 and platelet and endothelial cell adhesion molecule-1 (Pecam1) and NOS activity were measured in intima-containing media and adventitial specimens of ascending aortic tissue. The presence of 2 Nos3 single-nucleotide polymorphisms (SNPs; -786T/C and 894G/T) was determined for non-aneurysmal (NA) and aneurysmal patients with BAV (n = 40, 89, respectively); patients with tricuspid aortic valve (TAV) and aneurysm (n = 151); and NA patients with TAV (n = 100). Elevated Nos3 relative to Pecam1 and reduced Pecam1 relative to a housekeeping gene were observed within intima-containing aortic specimens from BAV patients when compared with TAV patients. Lower Nos3 in the adventitia of aneurysmal specimens was noted when compared with specimens of NA aorta, independent of valve morphology. NOS activity was similar among cohorts in media/intima and decreased in the diseased adventitia, relative to control patients. Aneurysmal BAV patients exhibited an under-representation of the wild-type genotype for -786 SNP. No differences in genotype distribution were noted for 894 SNP. Primary intimal endothelial cells from patients with at least 1 C allele at -786 SNP exhibited lower Nos3 when compared with wild-type cells. These findings of differential Nos3 in media/intima versus adventitia depending on valve morphology or aneurysm reveal new information regarding aneurysmal pathophysiology and support our ongoing assertion that there are distinct mechanisms giving rise to ascending aortopathy in BAV and TAV patients.

THE EFFECT OF NOS3 AND AGTR1 GENOTYPES ON THE COURSE OF THE ARTERIAL HYPERTENSION FOR THE OVERWEIGHT OR OBESE PATIENTS

The aim: Objective of the research is to determine the effect of NOS3 and AGTR1 genotypes of patients with arterial hypertension and high body mass index in the course of the disease. Materials and methods: 58 patients (22 men and 36 women) with AH and high BMI were examined. The average age of the examined patients was 53.6±8.7 years. The analysis of rs1799983 polymorphisms of the NOS3 gene (localization 7q36.1; 7:150999023) and AGTR1 (type 1 receptor for angiotensin 2 1166 A>C) was performed using TaqMan assay (Thermo Fisher Scientific, USA) by real-time PCR (Applied Biosystems, USA) using TaqMan probe amplification products. Genomic DNA samples were isolated from stabilized blood using a Genomic DNA Mini Kit reagent (Invitrogen, USA). The Statistica 10 program (StatSoft Inc.) was used for statistical processing of the obtained data, USA). The independent samples were compared using the Mann-Whitney (U) criterion. In all cases of statistical evaluation, the reliability of differences was taken into account at a value of p<0.05. Results and conclusions: Polymorphism of the NOS3 and AGTR1 genes is associated with early development and complicated course of cardiovascular pathology. The combination of NOS3 and AGTR1 gene polymorphism in patients with the high body mass index increases the risk of complications in hypertension. Using a mathematical model to predict the probability (95%) of genetic mutations in two genes (NOS3 and AGTR1) increases the effectiveness of diagnosis for patients with the high risk of developing cardiovascular complications.

Intra‐individual differences in the effect of endurance versus resistance training on vascular function: A cross‐over study

We used a within‐subject, cross‐over design study to compare the impact of 4‐weeks' resistance (RT) versus endurance (END) training on vascular function. We subsequently explored the association of intra‐individual effects of RT versus END on vascular function with a single nucleotide polymorphism (SNP) of the NOS3 gene. Thirty‐five healthy males (21 ± 2 years old) were genotyped for the NOS3 rs2070744 SNP and completed both training modalities. Participants completed 12 sessions over a 4‐week period, either RT (leg‐extension) or END (cycling) training in a randomized, balanced cross‐over design with a 3‐week washout period. Participants performed peak oxygen uptake (peak VO2) and leg‐extension single‐repetition maximum (1‐RM) testing, and vascular function assessment using flow‐mediated dilation (FMD) on 3 separated days pre/post‐training. Peak VO2 increased after END (p < 0.001), while 1‐RM increased after RT (p < 0.001). FMD improved after 4‐weeks’ training (time effect: p = 0.006), with no difference between exercise modalities (interaction effect: p = 0.92). No relation was found between individual changes (delta, pre‐post) in FMD to both types of training (R2 = 0.06, p = 0.14). Intra‐individual changes in FMD following END and RT were associated with the NOS3 SNP, with TT homozygotes significantly favoring only END (p = 0.016) and TC/CC tending to favor RT only (p = 0.056). Although both training modes improved vascular function, significant intra‐individual variation in the adaptation of FMD was found. The association with NOS3 genotype suggests a genetic predisposition to FMD adapting to a specific mode of chronic exercise. This study therefore provides novel evidence for personalized exercise training to optimize vascular health.

Impact on Longevity of Genetic Cardiovascular Risk and Lifestyle including Red Meat Consumption.

Background Cardiovascular risk (CVR) underlies aging process and longevity. Previous work points to genetic and environmental factors associated with this risk. Objectives The aim of this research is to look for any CVR gene-gene and gene-multifactorial/lifestyle interactions that may impact health and disease and underlie exceptional longevity. Methods A case-control study involving 521 both gender individuals, 253 centenarians (100.26 ± 1.98 years), and 268 controls (67.51 ± 3.25 years), low (LCR, n = 107) and high (HCR, n = 161) CVR. Hypertension, diabetes, obesity (BMI, kg·m−2), and impaired kidney function were defined according to standard criteria. CVR was calculated using Q risk®. DNA was genotyping (ACE-rs4646994, AGT-rs4762, AGR1-rs5182, GRK4-rs2960306, GRK4-rs1024323, NOS3-rs1799983, and SLC12A3-rs13306673) through iPlex-MassARRAY®, read by MALDI-TOF mass spectrometry, and analyzed by EARTDECODE®. Results Antilongevity factors consisted (OR 95% CI, p < 0.05) BMI 1.558 (1.445-1.680), hypertension 2.358 (1.565-3.553), smoking habits 4.528 (2.579-7.949), diabetes 5.553 (2.889-10.675), hypercholesterolemia 1.016 (1.010-1.022), and regular consumption of red meat 22.363 (13.987-35.755). Genetic aspects particularly for HCR individuals ACE II (OR: 3.96 (1.83-8.56), p < 0.0001) and NOS3 TT (OR: 3.11 (1.70-5.70), p < 0.0001) genotypes were also risk associate. Obesity, smoking, hypercholesterolemia, and frequent consumption of red meat have an additive action to hypertension in the longevity process. There was a synergistic interaction between the endothelial NOS3 genotypes and the severity of arterial hypertension. An epistatic interaction between functional genetic variants of GRK4 and angiotensinogen was also observed. Conclusions Cardiovascular risk-related genetic and multifactorial or predominantly lifestyle aspects and its interactions might influence the aging process and contribute to exceptional longevity in Portuguese centenarians. Besides lifestyle, the activity of nitrite oxide synthase may be one of the main physiologic regulators of cardiovascular protection in the path of longevity.

ASSOCIATION OF GENOTYPES OF POLYMORPHISM NOS3 WITH MACROANGIOPATHIES IN PATIENTS WITH HYPERTONIC DISEASE COMBINED WITH TYPE 2 DIABETES MELLITUS

The purpose - to study the probability of association of genotypes of polymorphism NOS3 with macroangiopathies in patients with artherial hypertension (AH) with type 2 diabetes mellitus (DM). Material and methods . 100 patients with AH and type 2 DM and were examined. In all persons the lesions of the arteries of mixed type were verified. The alleles of the polymorphic sites of the synthetase gene of nitric oxide 3 (NOS3, Gene ID: 4846, locus-7q36, polymorphism -786T> C transversion, dbSNP-rs2070744) were studied. Results. The distribution of genotypes NOS3 polymorphism in AG and DM2 group characterized by a probable deviation from the Hardy-Weinberg equilibrium (p<0.01). In monolocal analysis of NOS3 alleles and genotypes with of macroangiopathy, a significant difference was found (p <0.05). The allele -786C associated with an increased (2.55) of mixed-type vascular lesions vs. control group (OR = 4,27; 95% CI=1,86 - 9.77; p<0.05). It was set decreased (4,46 times) frequency of allele -786T in AG and DM 2 (p<0.05), and homozygous risk allele C (2 times) vs. control group (95% CI=0.10-0,50; p<0.05). Conclusions. It was set the probable differences and decreased the frequency of protective alleles and genotypes in patients with hypertension and diabetes mellitus with macroangiopathy.

Replication of a Gene-Diet Interaction at CD36, NOS3 and PPARG in Response to Omega-3 Fatty Acid Supplements on Blood Lipids: A Double-Blind Randomized Controlled Trial

BackgroundModulation of genetic variants on the effect of omega-3 fatty acid supplements on blood lipids is still unclear. MethodsIn a double-blind randomized controlled trial, 150 patients with type 2 diabetes (T2D) were randomized into omega-3 fatty acid group (n = 56 for fish oil and 44 for flaxseed oil) and control group (n = 50) for 180 days. All patients were genotyped for genetic variants at CD36 (rs1527483), NOS3 (rs1799983) and PPARG (rs1801282). Linear regression was used to examine the interaction between omega-3 fatty acid intervention and CD36, NOS3 or PPARG variants for blood lipids. FindingsSignificant interaction with omega-3 fatty acid supplements was observed for CD36 on triglycerides (p-interaction = 0.042) and PPAGR on low-density lipoprotein-cholesterol (p-interaction = 0.02). We also found a significant interaction between change in erythrocyte phospholipid omega-3 fatty acid composition and NOS3 genotype on triglycerides (p-interaction = 0.042), total cholesterol (p-interaction = 0.013) and ratio of total cholesterol to high-density lipoprotein cholesterol (p-interaction = 0.015). The T2D patients of CD36-G allele, PPARG-G allele and NOS3-A allele tended to respond better to omega-3 fatty acids in improving lipid profiles. The interaction results of the omega-3 fatty acid group were mainly attributed to the fish oil supplements. InterpretationThis study suggests that T2D patients with different genotypes at CD36, NOS3 and PPARG respond differentially to intervention of omega-3 supplements in blood lipid profiles.

The nitric oxide synthase-3 codon 298 polymorphism is not associated with late-onset sporadic Alzheimer's dementia and Lewy body disease in a sample from Hungary.

An association study was performed between apolipoprotein E (apoE) polymorphism and the common structural polymorphism Glu/Asp at codon 298 of the nitric oxide synthase (NOS3) gene in late-onset sporadic Alzheimer's dementia probands (LOAD), diffuse Lewy body dementia cases (DLBD) and controls in a Hungarian sample. The frequency of individuals who carried the apoE epsilon4 allele was significantly more common in both dementia groups (LOAD, 20%; DLBD, 27%; control, 8%; control versus DLBD, chi2=13.264, degrees of freedom=2, P<0.001; control versus LOAD, chi2=6.628, degrees of freedom=2, P<0.036). However, there were no significant differences in the NOS3 genotype and allele distributions between the LOAD, DLBD and control groups. The apoE status has been found to be independent from the NOS3 codon 298 polymorphism in the examined cohort. Despite the facts that NOS3 is associated with neuritic sprouting, and aberrant neuronal and glial expression of the same molecule has been found in neurodegenerative diseases, it is unlikely that the polymorphism Glu/Asp of the NOS3 gene is involved in the development of LOAD and DLBD.

The association between no-synthases gene polymorphisms and post-traumatic knee ostearthritis development among Rostov region residents

Background. Knee osteoarthritis (OA) is a common chronic degenerative disease. The risk factors for the development of knee OA are joint trauma and genetic predisposition. The aim of the present work was to study the associations between gene polymorphisms -84G A nNOS and -786T C eNOS and the risk of post-traumatic knee osteoarthritis (PTOA) development among Rostov region residents and to define the interactions between these polymorphisms and nitrite level in the plasma and synovial fluid (SF) and chondrocyte apoptosis in patients with PTOA. Materials and Methods. Case-control study involved 117 post-traumatic knee OA patients and 94 healthy controls. The nNOS and eNOS polymorphisms were determined by polymerase chain reaction. The nitrite concentrations in the plasma and synovial fluid were defined using Griess reaction. Chondrocyte apoptosis in cartilage sections was assessed morphologically by electron microscopy. Results. The G-84A nNOS genotype showed statistical differences between groups. The A allele is associated with PTOA development (OR 2,02, CI 1,08-3,76, p = 0,02). The eNOS genotype did not show statistical difference between groups. The NOx- concentration was higher both in plasma (p = 0,022) and synovial fluid (p = 0,014) of PTOA patients compared with plasma of healthy subjects. Multiple regression analyses demonstrated that the nitrite level in the SF is linked with -786T C NOS3 genotype; the -786С allele leaded to the decreasing in NOx- concentration. The electron microscopy confirmed the presence of early and late apoptotic chondrocytes in PTOA cartilage tissue. Conclusion. The G-84A nNOS polymorphism may be associated with PTOA development and chondrocyte apoptosis intensification. The -786С allele of -786T C NOS3 is associated with reduced NOx- concentration in the synovial fluid.

A NOS3 Polymorphism Determines Endothelial Response to Folate in Children with Type 1 Diabetes or Obesity

To determine the effect of polymorphisms in NOS3 and folate pathway enzymes on vascular function and folate status and endothelial response to folate in children with diabetes or obesity. A total of 244 subjects (age 13.8 ± 2.8 years, 125 males) were studied for NOS3 and/or folate pathway polymorphisms using polymerase chain reaction/restriction fragment length polymorphism, including at baseline: 139 with type 1 diabetes; 58 with obesity; and 47 controls. The effect of NOS3 genotype on endothelial response to folate (5 mg) was assessed in 85 subjects with diabetes and 28 obese subjects who received active treatment during intervention trials. Vascular function (flow-mediated dilatation [FMD] and glyceryl trinitrate-mediated dilatation), clinical, and biochemical measurements were assessed at baseline and 8 weeks in folate intervention studies. Folate pathway enzyme and NOS3 polymorphisms did not significantly affect baseline vascular function. The polymorphism in intron 4 of endothelial nitric oxide synthase altered endothelial response to folate significantly: in subjects with diabetes FMD improved by 6.4 ± 5% (insertion carriers) vs 2.3 ± 6.6% (deletion carriers), P = .01; in obese subjects FMD improved by 1.8 ± 5.4% (insertion carriers) and deteriorated by -3.2 ± 7.2% (deletion carriers), P = .05. More subjects carrying the insertion normalized FMD after folate supplementation (insertion 64% vs deletion 28%, χ(2) = 10.14, P = .001). A NOS3 polymorphism predicts endothelial response to folate in children with diabetes or obesity, with implications for vascular risk and folate intervention studies.

NOS3 tagSNPs does not modify the chronic kidney disease progression in autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary and progressive renal disorder. It is also recognised as the most frequent genetic cause of chronic kidney diseases (CKD). In the present study, four tagging SNPs and two more well studied polymorphisms (Intron 4 VNTR and Glu298Asp) the NOS3 gene were investigated to unravel the potential modifier effect of NOS3 gene on the progression of CKD in ADPKD. A total of 102 ADPKD patients and 106 controls were selected for the study. The tagSNPs and Glu298Asp polymorphisms were genotyped using FRET-based KASPar method and intron-4 VNTR by polymerase chain reaction electrophoresis. The genotypes and haplotypes in the controls and ADPKD subjects were analysed by χ(2) tests and haploview software. Mantel-Haenszel stratified and univariate analyses were performed to estimate the influence of different genotypes between different CKD stages and hypertension. The tagSNPs of NOS3 genotypes and haplotypes did not exhibit any significant differences between controls and ADPKD patients. The significant linkage disequilibrium was observed between the rs3918184 and rs2853796 by forming LD block. In univariate analysis, the age and family history of Diabetes mellitus (DM) showed significant association with advancement of CKD, but not with the eNOS polymorphisms. Our data suggests that there is no evidence for the involvement of NOS3 tag SNPs in the progression to CKD in ADPKD patients. A systematic study using well validated functional SNPs is necessary to clarify the role of the NOS3 gene in the development of CKD in ADPKD.

Genetic influences on right ventricular systolic pressure (RVSP) in chronic obstructive pulmonary disease (COPD).

BackgroundPulmonary hypertension (PH) is a complication of chronic obstructive pulmonary disease (COPD). This study examined genetic variations in mediators of vascular remodelling and their association with PH in patients with COPD. In patients with COPD, we genotyped 7 SNPs in 6 candidate PH genes (NOS3, ACE, EDN1, PTGIS, SLC6A4, VEGFA). We tested for association with right ventricular systolic pressure (RVSP), spirometry and gas transfer, and hypoxemia.MethodsIn patients with COPD, we genotyped 7 SNPs in 6 candidate PH genes (NOS3, ACE, EDN1, PTGIS, SLC6A4, VEGFA). We tested for association with right ventricular systolic pressure (RVSP), spirometry and gas transfer, and hypoxemia.Results580 COPD patients were recruited, 341 patients had a transthoracic echocardiogram, with RVSP measurable in 278 patients (mean age 69 years, mean FEV1 50% predicted, mean RVSP 44 mmHg, median history of 50 pack-years). Of the 7 tested SNPs, the NOS3-VNTR polymorphism was significantly associated with RVSP in a dose-dependent fashion for the risk allele: mean RVSP for a/a and a/b genotypes were 52.0 and 46.6 mmHg respectively, compared to 43.2 mmHg for b/b genotypes (P = 0.032). No associations were found between RVSP and other polymorphisms. ACE II or ID genotypes were associated with a lower FEV1% predicted than the ACE DD genotype (P = 0.028). The NOS3-298 TT genotype was associated with lower KCO % predicted than the NOS3-298 GG or GT genotype (P = 0.031).ConclusionsThe NOS3-VNTR polymorphism was associated with RVSP in patients with COPD, supporting its involvement in the pathogenesis of PH in COPD. ACE and NOS3 genotypes were associated with COPD disease severity, but not with the presence of PH. Further study of these genes could lead to the development of prognostic and screening tools for PH in COPD.

Association between endothelial nitric oxide gene intron 4a4b VNTR polymorphism and plasma homocysteine concentrations in Tunisian male patients with myocardial infarction

Many studies have shown that hyperhomocysteinemia may be an independent risk factor for coronary artery disease. However, not all prospective studies support an association between elevated plasma homocysteine levels and coronary artery disease. Nitric oxide (NO) plays a relevant role in various events during atherogenesis, and in vitro data suggest that NO may modulate total homocysteine (tHcy) concentrations, whereas polymorphisms of the endothelial nitric oxide (NOS3) gene have been reported to be related to an increased risk of myocardial infarction (MI) and hyperhomocysteinemia, but the results have been controversial. We hypothesized that the NOS3 synthase 4a4b VNTR polymorphism is a determinant of tHcy concentrations and tested this in 310 patients with MI and 250 controls. The NOS3 gene intron 4a4b VNTR polymorphism was analyzed by polymerase chain reaction analysis. There was no significant difference in the homocysteine levels between patients with MI and controls. The frequencies of the NOS34b4b, 4b4a, and 4a4a genotypes in the MI group were significantly different from those in the control group. In patients with MI, plasma tHcy concentrations were significantly different among the NOS3 genotypes (13.5±4.5, 18.5±3.9, and 20.4±2.1 μmol/L for 4b4b, 4a4b, and 4a4a genotypes, respectively; P<.001). However, no significant difference was observed for tHcy concentrations in the control group. In conclusion, the NOS34a4b gene polymorphism (presence of 4a allele) is associated with MI and influences plasma tHcy concentrations in patients with MI in the Tunisian male population.

Correlates of endothelial function and the peak systolic blood pressure response to a graded maximal exercise test

PurposeAn elevated systolic blood pressure (SBP) response to a graded maximal exercise stress test (GEST) may be a predictor of endothelial dysfunction and hypertension. We examined relationships among the GEST peak SBP response and indicators of endothelial function. MethodsMen (n=48, 43.7±1.4yr) with high BP (145.1±1.5/85.5±1.1mmHg) completed a GEST. Peak SBP was the highest SBP achieved during the GEST. Blood samples were taken for fasting glucose and insulin, nitric oxide (NO), and DNA. Endothelial nitric oxide synthase (NOS3, rs2070744) −786 T>C genotyping was determined by PCR. NOS3 genotypes were combined using a dominant model [TT (n=24); TC/CC (n=24)]. Brachial artery reactivity (BAR) was determined via ultrasound before, 1min, and 3min post occlusion and calculated as % change. Analysis of variance (ANOVA) tested changes in the peak SBP GEST response by NOS3 genotype. Multiple variable regression analyses examined relationships among the GEST peak SBP response and measures of endothelial function. Results%BAR change at 1min (r2=0.093, p=0.020), glucose (r2=0.062, p=0.014), NOS3 −786 T>C (r2=0.040, p=0.024), NO (r2=0.037, p=0.064), and age (r2=0.009, p=0.014) explained 24.1% of the GEST peak SBP response (p=0.043). The GEST peak SBP change from baseline was 11.1±5.0mmHg higher among those with the NOS3 C allele (92.4mmHg+3.8) than the NOS3 TT genotype (81.3mmHg+3.2) (p=0.03). ConclusionIndicators of endothelial function appear to explain a clinically significant portion of the GEST peak SBP response. Further investigation is needed to unravel the mechanisms by which endothelial function influences the GEST peak SBP response.

Combined effects of antioxidant vitamin and NOS3 genetic polymorphisms on breast cancer risk in women

It is becoming increasingly clear that there is wide heterogeneity in genetic predisposition to breast cancer and that breast cancer risk is determined by interactive effect between genetic and environmental factors. We investigated the combined effects of antioxidant vitamin intake and NOS3 genetic polymorphisms on breast cancer risk in a Korean population (Seoul Breast Cancer Study). Histologically confirmed breast cancer cases (n=512) and age, menopause status-matched controls (n=512) with no present or previous history of cancer were recruited from several teaching hospitals in Seoul during 2001-2003. Two genetic polymorphisms of NOS3 (298G>T and-786T>C) were assessed by single base extension assays. No overall association between the individual NOS3 genotypes or diplotypes and breast cancer risk was found, although the difference between cases and controls in the frequency of the NOS3 894 G>T polymorphism showed borderline significance (OR=0.74, 95% CI=0.52-1.06). There was no significant difference in energy intake or the intake of antioxidant vitamins between cases and controls, with the exception of vitamin E (OR=0.49 lowest vs. highest quartile, P(trend)<0.01). On the other hand, our results suggest that antioxidant vitamin intake may modify the effects of the NOS3-786T>C or 894 G>T genetic polymorphisms on breast cancer risk. Although a multiplicative interaction was not observed, the protective effect of β-carotene intake on breast cancer risk was observed predominantly in individuals with the TG:TG diplotype of NOS3 (OR=0.68) but not observed with others diplotype. An inverse association between vitamin E intake and breast cancer risk was observed for individuals with the NOS3 786 TC+TT genotype and the NOS3 894 GG genotype. In addition, folic acid had a protective effect in the NOS3 786 TT and NOS3 894 GT+TT genotype. Our results suggest that intake of antioxidant vitamins might modify the association between genetic polymorphisms of NOS3 and breast cancer risk.

Effects of human endothelial gene polymorphisms on cellular responses to hyperglycaemia: Role of NOS3 (Glu298Asp) and ACE (I/D) polymorphisms

The functional relevance of NOS3 and ACE genetic variations to endothelial cell function is largely unstudied. Here we tested the functional relevance of the NOS3 (Glu298Asp) polymorphism and ACE (I/D) polymorphism in endothelial cells in vitro. Our hypothesis was that these genetic polymorphisms alter endothelial cell sensitivity to glucose and 3-nitrotyrosine (3NT). Genotyped HUVECs were incubated with glucose, free 3NT or a combination of these two toxicants. Significant differences in glucose-induced cell death and free 3NT-induced cell death were observed among the NOS3 genotypes. Combined glucose/3NT caused increased toxicity among the NOS3 genotypes. No differences were observed among the ACE genotypes in their responses to glucose/3NT. These data demonstrate that the NOS3 genotype may be an important predictor of, or be mechanistically involved in, endothelial vulnerability, whereas the ACE I/D genotype is apparently less important. Thus this NOS3 genetic variation may play a role in vulnerability to endothelium-dependent diabetic vascular complications.

The effects of NOS3 Glu298Asp variant on colorectal cancer risk and progression in Turkish population

Endothelial nitric oxide synthase (eNOS), coded by the gene NOS3, may play an important role in uncontrollable cellular growth in several cancer types. Our study was performed to test the association between Glu298Asp polymorphisms in the NOS3 gene and colorectal cancer risk and progression. In this study, NOS3 Glu298Asp polymorphism was genotyped in 84 patients with colorectal cancer and 99 healthy subjects using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. There were significant differences in the distribution of NOS3 genotypes and frequencies of the alleles between colorectal cancer patients and controls (P = 0.016, P = 0.006, respectively). The increased frequency of NOS3 Glu298Asp homozygotes genotypes in patients who had advanced tumour stage was statistically significant (P = 0.042). Our findings have suggested that NOS3 Glu298Asp polymorphism might be associated with the risk and progression of colorectal cancer in Turkish population.

Polymorphisms in nitric-oxide synthase 3 may influence the risk of urinary-bladder cancer

Nitric oxide (NO) is an important biological messenger known to influence several types of human cancers. NO formation is catalyzed by three different nitric oxide synthase (NOS) enzymes. In this study we analyzed if the NOS3 promoter polymorphism −786T>C (rs2070744) and the NOS3 Glu298Asp polymorphism in exon 7 (rs1799983) influence risk and pathogenesis of urinary-bladder cancer. Allelic discrimination and DNA sequencing were used to determine the −786T>C and the Glu298Asp NOS3 genotypes in 359 urinary-bladder cancer patients, from a population-based patient material, and 164 population controls. Patient genotypes were combined with information on tumor stage, grade, stage and grade progression and cancer-specific death, using a 5-year clinical follow-up. A threefold increased odds ratio for bladder cancer was found in homozygous carriers of the C allele of the −786T>C promoter polymorphism (p=0.017). No increased bladder cancer risk was found for the Glu298Asp polymorphism, but there was an association between the Glu298Asp and tumor grade (p=0.040). Our results suggest that the NOS3 promoter polymorphism −786T>C may influence bladder cancer risk.