Relationship between hemorheology and Glu(298)Asp polymorphism of endothelial nitric oxide synthase gene in patients with coronary artery disease

This study aimed to investigate the relationship between endothelial nitric oxide synthase Glu(298)Asp gene polymorphism and hemorheological parameters. Red blood cell (RBC) deformability, aggregation were measured using an ectacytometry, whole blood, plasma viscosities were determined by a viscometer. Restriction fragment length polymorphism was used to detect polymorphism. Plasma nitrite, nitrate concentrations were determined by Griess method. The genotype distribution of the control group was as follows: 50 (67.5%) GG, 21 (28.4%) GT, 3 (4.1%) TT. A 48 (57.8%) of the patients with CAD had GG, 28 (33.7%) GT, 7 (8.5%) of them TT genotype. RBC aggregation index of CAD patients with G allele was higher and t½ lower compared to controls carrying the same allele. The amplitude of RBC aggregation of healthy subjects with T allele, who are under increased cardiovascular risk was lower compared to control subjects with G allele. The results of this study indicate that, alterations in RBC aggregation seem to be a consequence of CAD, more than being a preexisting cause. Additionally, some compensatory mechanisms by causing decrements in RBC aggregation, may help regulation of circulation in healthy individuals with high cardiovascular risk.     

NO Level and Endothelial NO Synthase Gene Polymorphism （Glu298Asp） in the Patients with Coronary Artery Disease from the Turkish Population

A healthy endothelium plays a core role in cardiovascu-lar control [1]. In the endothelial cell, nitric oxide (NO) issynthesized by the endothelial nitric oxide synthase (eNOS)encoded by a 26-exon gene (NOS 3) located on chromo-some 7 [2]. Besides its regulatory functions on vasomotortone and blood flow, endothelial NO is known to inhibitthe platelet activation and modulate migration and growthof the vascular smooth muscle [3]. Indirect evidence sug-gests that alterations of the NO pathwa…     

Oxidative stress and eNOS (Glu298Asp) gene polymorphism in preeclampsia in Indian population

Oxidative stress causing widespread endothelial dysfunction has been proposed as a key factor involved in the development of preeclampsia (PE). With this background our objective was to study oxidative stress biomarkers like nitric oxide and malondialdehyde (MDA) and to correlate these markers with endothelial nitric oxide synthase (eNOS) (Glu298Asp) gene polymorphism. This cross-sectional study included 300 pregnant women diagnosed with PE and 200 women with normal pregnancy. Plasma NO and MDA levels were analyzed using student's t test and eNOS gene polymorphism was studied by performing polymerase chain reaction amplification and restriction length polymorphism and frequencies were distributed by using χ(2) analysis. The mean plasma levels of NO were significantly lower in study group while MDA levels were significantly higher in study group (P < 0.001). Genotypic and allelic frequency of eNOS gene in both groups was found to be significant (P < 0.05). The intergenotypic variation of NO and MDA levels was found to be significant (P < 0.001). We concluded that the plasma levels of NO are decreased while MDA levels are increased in subjects with PE and that might contribute to the pathophysiology of PE. As observed in this study Glu298Asp eNOS gene polymorphism showed significant association with PE.     

Glu298Asp polymorphism of the endothelial nitric oxide synthase gene in Turkish patients with ischemic stroke

The low plasma nitric oxide concentrations and reduced vascular reactivity are considered major proatherogenic mechanisms in cardiovascular diseases. The present study aimed to assess the allelic frequency and the genotypic distribution of the Glu298Asp gene polymorphism at exon 7 of endothelial nitric oxide synthase (eNOS) gene in Turkish ischemic stroke patients compared to appropriate healthy controls, and to correlate the genetic findings with stroke subtypes. The study population included 146 (75 males, 71 females) patients with ischemic stroke which were categorized according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) and 133 (34 males, 99 females) healthy subjects. The eNOS polymorphism was identified with a PCR followed by RFLP with the restriction enzyme BanII. Genotypes were defined as GG, GT, and TT according to the presence of the G and T alleles. In this case-control study, we did not find any significant difference in either the genotypic distribution or allelic frequency of Glu298Asp gene polymorphism between the patients and the controls. In addition, there was also no significant difference for the genotype distribution and the allelic frequency among the stroke subtypes. The results suggested the lack of the association between the Glu298Asp gene polymorphism and ischemic stroke or subtypes of ischemic stroke in the Turkish population.     

Glu298Asp polymorphism influences the beneficial effects of fish oil fatty acids on postprandial vascular function

Our objective was to determine whether the endothelial nitric oxide synthase (eNOS) Glu298Asp polymorphism influences vascular response to raised NEFA enriched with saturated fatty acids (SFA) or long-chain (LC) n-3 polyunsaturated fatty acids (PUFA). Subjects were prospectively recruited for genotype (Glu298, n = 30 and Asp298, n = 29; balanced for age and gender) consumed SFA on two occasions, with and without the substitution of 0.07 g fat/kg body weight with LC n-3 PUFA, and with heparin infusion to elevate NEFA. Endothelial function was measured before and after NEFA elevation (240 min), with blood samples taken every 30 min. Flow-mediated dilation (FMD) decreased following SFA alone and increased following SFA+LC n-3 PUFA. There were 2-fold differences in the change in FMD response to the different fat loads between the Asp298 and Glu298 genotypes (P = 0.002) and between genders (P < 0.02). Sodium nitroprusside-induced reactivity, measured by laser Doppler imaging with iontophoresis, was significantly greater with SFA+LC n-3 PUFA in all female subjects (P < 0.001) but not in males. Elevated NEFA influences both endothelial-dependent and endothelial-independent vasodilation during the postprandial phase. Effects of fat composition appear to be genotype and gender dependent, with the greatest difference in vasodilatory response to the two fat loads seen in the Asp298 females.     

Association between Glu298Asp/677C-T single nucleotide polymorphism in the eNOS/MTHRF gene and blood stasis syndrome of ischemic stroke

Blood stasis syndrome of ischemic stroke (BSS-IS) is a common clinical phenotype that may be affected by certain mutagenic environmental factors or chemotherapeutic drugs; however, the role of susceptibility genes remains unclear. Previous studies have shown that ischemic stroke (IS) was closely associated with the Glu298Asp polymorphism in the eNOS gene and the 677C-T (Ala→Val) polymorphism in methylenetetrahydrofolate reductase (MTHRF) gene. Therefore, these two single nucleotide polymorphisms (SNPs) were selected to detect their associations with BSS-IS in this study. A SNP chip was employed to screen the SNP variation between both groups, and the results were verified using denaturing high-performance liquid chromatography (DHPLC) and restriction fragment length polymorphism (RFLP). The results confirmed that the TT genotype of Glu298Asp in the eNOS gene may be one of the risk factors associated with BSS-IS, while the genotype of 677C-T (Ala→Val) in the MTHRF gene may not be relevant to BSS-IS.     

Association between angiotensin-converting enzyme gene polymorphism and coronary artery disease

An insertion/deletion (I/D) polymorphism in the gene for angiotensin-converting enzyme (ACE) is associated with myocardial infarction and other cardiac pathology. There is evidence for a role of the renin-angiotensin system in cell growth and in the repair of damaged arterial walls, so the ACE gene is postulated to be a candidate gene affecting the important clinical problem of coronary artery disease (CAD). In view of the clinical importance of the ACE as a major marker of cardiovascular diseases, we investigated the I/D polymorphism of the ACE gene in Turkish CAD patients in comparison with control subjects to evaluate a possible association between CAD and the gene encoding ACE. Polymerase chain reaction, restriction fragment length polymorphism, and agarose gel electrophoresis techniques were used to determine the ACE genotype in 58 subjects. The frequencies of ACE D and ACE I allele among the patients with CAD were 62.26% and 37.73 % and in the control subjects were 49.3% and 50.76%, respectively. The greater frequency of deletion allele (D) was in the CAD group than in the control subjects was significant (P < 0.01).     

Association of the Glu298Asp polymorphism in the endothelial nitric oxide synthase gene with essential hypertension resistant to conventional therapy

Endothelial nitric oxide synthase (eNOS) produces nitric oxide (NO) which, after diffusing into vascular smooth muscle cells, activates guanylate cyclase leading to vasodilatation. A polymorphism (894G to T) in exon 7 of the eNOS gene causes the conversion of Glu to Asp in position 298. The recently described crystal structure of the heme domain of eNOS protein shows that Glu298 is fully solvent accessible and distant from regions integral to enzyme function. Searching for phenotypic expression of eNOS gene variants, we genotyped a group of patients with essential hypertension (H, n = 119) for the Glu298Asp polymorphism and compared them with age- and sex-matched healthy normals (N, n = 85). To specify phenotypic expression further, the hypertensive patients were subdivided into one group that responded well to regular antihypertensive therapy (CH, n = 45) and one group that was resistant to the therapy (RH, n = 74). Patients with BP higher than 140/90 mmHg when on adequate lifestyle modification and triple-combination therapy (including diuretics) were considered resistant. In RH and H groups, a significantly higher frequency of T alleles (P = 0.022 and P = 0.046, respectively) was found compared to normotonics (N). In well-controlled hypertonics, the same tendency was found, but did not reach statistical significance. The Glu298Asp polymorphism may contribute to the complex pathogenesis of essential hypertension and may be a factor in the resistance of these patients to conventional antihypertensive therapy. The presence of this allele may thus be predictive of the patients' therapeutic response.     

Preliminary computational modeling of nitric oxide synthase 3 interactions with caveolin-1： influence of exon 7 Glu298Asp polymorphism

The significance of endothelial nitric oxide synthase 3 （NOS3） activity has been recognized for many years, however it was only recently that the complicated regulation of this constitutively expressed enzyme in endothelial cells was identified. A critical component of the NOS3 regulatory cyde in endothelial cells is its intracellnlar localization to caveolae. The caveolar coordination of NOS3, more specifically its interaction with caveolin-1 （Cav-1）, plays a major role in normal endothelial NOS3 activity and vascular bioavailability of nitric oxide. We have recently shown that the presence of NOS3 exon 7 Glu298Asp polymorphism caused diminished shear-dependent NOS activation, was less extensively associated with caveolae, and had a decreased degree of interaction with Cav-1. Here, we carried out preliminary investigations to identify possible mechanisms of the genotype-dependent endothelial cell responses we observed in our previous investigations. Through this approach we tested the hypothesis that computer simulations could provide insights regarding the contribution of this single nucleotide polymorphism to regulation of the NOS3 isoform. We observed that in the Glu/Asp and Asp/Asp mutant genotypes, the amount of NOS3 associated with Cav-1 was significantly lower. Additionally, we have shown, using a theoretical computational model, that mutation of an amino acid at position 298 might affect the protein-protein interactions and localization of the NOS3 protein. These alterations might also affect the protein function and explain the enhanced disease risk associated with the presence of Glu298Asp polymorphism in the NOS3 protein.     

Study of the association between growth differentiation factor 15 gene polymorphism and coronary artery disease in a Chinese population

Growth differentiation factor (GDF)-15 belongs to a member of the transforming growth factor-β cytokine superfamily, and elevated GDF-15 concentrations are linked to increased risk of cardiovascular diseases and future adverse cardiac events in apparently healthy elderly women, acute coronary syndrome, and chronic heart failure. However, its genetic mechanisms are still unknown. We investigated whether GDF-15 −3148C>G variant (SNP, rs4808793) is associated with a predisposition to coronary artery disease (CAD) and its severity in a Chinese population. We studied 418 consecutive patients, including 192 with coronary stenosis ≥50% or previous myocardial infarction and 226 controls without documented CAD. Coronary artery disease cases and controls were genotyped for SNP rs4808793 by using the ligase detection reaction method. The three genotypes CC, CG, and GG were present in rs4808793. No differences were found in genotype distribution and allele frequencies of rs4808793 between subjects with and without CAD, or when grouped according to sex. Logistic regression did not reveal any increased risk of CAD in subjects carrying the CG, GG genotype, or G allele at rs4808793 compared with individuals carrying the CC genotype or C allele; this finding was the same when subjects were grouped by sex (all P > 0.05). Rs4808793 does not affect main anthropometric and metabolic characteristics, nor did there exists any association between rs4808793 and the severity of coronary lesions (all P > 0.05). Our data do not support an association of rs4808793 with CAD or its severity in a Chinese population.     

A missense Glu298Asp variant in the endothelial nitric oxide synthase gene is associated with coronary spasm in the Japanese

Coronary spasm plays an important role in the pathogenesis of not only variant angina but also ischemic heart disease in general. However, the precise mechanism(s) by which coronary spasm occurs remains to be elucidated. Coronary spasm may arise from interactions between environmental and genetic factors. Endothelial derived nitric oxide (NO) has been implicated in the control of vascular tone. We have recently shown that both basal and acetylcholine (ACh)-induced NO activities are impaired in the coronary arteries of patients with coronary spasm. The purpose of this study has been to elucidate the possible variants that occur in the coding region of the endothelial nitric oxide synthase (eNOS) gene and that may be associated with coronary spasm. After initial screening in the entire 26 coding regions of the eNOS gene, we found a missense Glu298Asp variant in exon 7 in patients with coronary spasm. We subsequently performed a larger scale study involving 113 patients with coronary spasm and 100 control subjects, who were all diagnosed by intracoronary injection of ACh. The analysis revealed a significant difference in the distribution of the variant between the coronary spasm group (21.2%) and control group (9.0%; P=0.014 for dominant effect). Thus, we have found the missense Glu298Asp variant in the eNOS gene by the analysis of its entire 26 coding regions. The variant is significantly associated with coronary spasm. Received: 2 February 1998 / Accepted: 9 April 1998     

Toll-like receptor 8 polymorphism and coronary artery disease

Toll-like receptors (TLRs) play roles in innate and adaptive immune responses. Some TLRs are involved in the pathogenesis of cardiovascular diseases. Coronary artery disease (CAD) has an inflammatory and immunological basis. We investigated whether TLR8 Met1Val and TLR8-129G>C single nucleotide polymorphisms (SNPs rs3764879 and rs3764880) are associated with CAD in the Chinese population. We enrolled 412 consecutive patients (185 with coronary stenosis ≥50% or previous myocardial infarction and 227 controls). Ligase detection reaction was performed to detect SNPs rs3764879 and rs3764880 of TLR8. The SNP at rs3764879 is in complete linkage disequilibrium with rs3764880. No significant difference was found in genotypic or allelic frequencies of these two common SNPs between CAD cases and controls (P > 0.05, respectively). No associations existed between these two SNPs and the severity of coronary artery stenosis (All P > 0.05). These results do not support an involvement of SNPs rs3764879 and rs3764880 of TLR8 in predisposition to CAD. Z. Chen and G. Ma contributed equally to this paper.     

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.     

MPO129A／G基因多态性与冠心病严重程度相关研究

目的：探讨髓过氧化物酶129A／G基因多态性与冠心病严重程度关系。方法：入选住院冠心病患者267例,均行冠脉造影检查。用比色法测定血清髓过氧化物酶活性;用聚合酶链反应．限制性片段长度多态性（PCR-RFLP）确定各研究对象的基因型。根据冠脉造影结果分别采用冠脉病变支数和Gensini评分来评估冠心病严重程度。结果：MPO129位点A、G等位基因频率分别为0．107和0．893。不同基因型组间血清髓过氧化物酶活性无明显差异,不同基因型在Gensini评分组间的分布无明显差异,基因型GG患者冠脉病变倾向于多血管病变。结论：髓过氧化物酶129A／G基因多态性与血清髓过氧化物酶活性无显著相关,其不能作为预测冠心病病变严重程度的理想指标。     

Lack of association between psoriasis vulgaris and red cell acid phosphatase polymorphism

Summary Polymorphism of red cell acid phosphatase (ACP-1; E.C. 3.1.3.2.) has been studied using the Cellogel technique of Martin et al. (1975) in 102 patients with psoriasis and 102 healthy controls. In contrast to two previous reports, no anomalies in distribution of phenotypes were found in patients or in controls.Results were obtained during medical thesis work of G. M.     

A lack of association between adiponectin polymorphisms and coronary artery disease in a Chinese population

We investigated the association between two single nucleotide polymorphisms (SNPs) in the adiponectin gene (rs822395 and rs266729) and coronary artery disease (CAD) in a case-control study of 198 unrelated Chinese CAD patients (with ≥ 70% coronary stenosis or previous myocardial infarction) and 237 non-CAD controls. The ligase reaction was used to detect SNPs rs822395 and rs266729, and the allelic association of these SNPs with the occurrence and severity of CAD was assessed. There were no significant differences in the genotypic or allelic frequencies of the two SNPs between control and CAD individuals. In addition, there was no association between the two SNPs and the severity of CAD based on the number of diseased vessels. The frequencies of alleles C and G at rs266729 differed significantly between females in the CAD and control groups, but not between males. Female carriers of allele G at rs266729 had a higher risk of CAD compared with allele C carriers (OR = 1.30, 95% CI: 1.09-2.64, p = 0.02). These results indicate a gender-specific effect of the adiponectin gene rs266729 variant in modulating the risk of CAD in women.     

APE1 Asp148Glu gene polymorphism and lung cancer risk: a meta-analysis

Many studies have examined the association between the APE1 T1349G (Asp148Glu) gene polymorphisms and lung cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, a meta-analysis was performed. The PubMed, Embase, Web of Science, and CNKI database was searched for case–control studies published up to June 2010. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, ten studies, comprising 2,696 lung cancer cases and 3,948 controls were included. Overall, for the G allele carriers (TG + GG) versus homozygote TT, the pooled OR was 1.037 (95% CI = 0.928–1.159 P = 0.001 for heterogeneity), for GG versus TT the pooled OR was 0.997 (95% CI = 0.861–1.154 P = 0.005 for heterogeneity). In the stratified analysis by ethnicity, significantly risks were not found among Asians or Caucasians. However, in the subgroup analyses by smoking status, significantly risks were found among smokers not in non-smokers. This meta-analysis suggested that the APE1 T1349G (Asp148Glu) polymorphism was not associated with lung cancer risk among Asians or Caucasians. But, the APE1 G allele was an increased risk factor for developing lung cancer among smokers.     

Lack of association between TLR4 rs4986790 polymorphism and risk of cardiovascular disease in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with increased cardiovascular (CV) mortality. Toll-like receptor-4 (TLR4) activates the innate immune response via NF-kB pathway and mitogen-activated protein kinase signaling, leading to expression of proinflammatory cytokines and chemokines. The G allele of TLR4 rs4986790 (+896A>G, Asp299Gly) gene polymorphism has been implicated in reduction of risk of atherosclerosis. In this study, 1481 RA patients fulfilling the 1987 American College of Rheumatology (ACR) criteria were genotyped for the rs4986790 TLR4 variant to determine the influence of this variant in the risk of CV events in these patients. Also, HLA-DRB1 status was determined using molecular based methods. Moreover, potential influence of rs4986790 variant in the development of subclinical atherosclerosis was assessed in a subgroup of RA patients with no history of CV events by the measurement of surrogate markers of subclinical atherosclerosis. No statistically significant differences in allele or genotype frequencies for the rs4986790 variant between RA patients who experienced CV events or not were found. Likewise, no significant association between this gene variant and any of the surrogate markers of subclinical atherosclerosis was found. In summary, results in our study do not support the hypothesis that the rs4986790 (+896A>G, Asp299Gly) TLR4 variant may influence predisposition for subclinical atherosclerosis and clinically evident CV disease in RA patients.