Prevalence of eNOS Glu298Asp Polymorphism in Healthy Volunteers from a Region of Northern India

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

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

Polygenic study of endurance-associated genetic markers ACE I/D, ACTN3 Arg(R)577Ter(X), CKMM A/G NcoI and eNOS Glu(G)298Asp(T) in male Gorkha soldiers

Background

Gorkhas, a sub-mountainous population of the Himalayan region, are known for strength and bravery. In the present study when “Gorkha” is used without brackets, we are mentioning Gorkhas of Tibeto-Burman origin. Physical capability, strength and endurance are important components of fitness associated with genetic traits. The aim of this study was to examine the endurance potential of male Gorkha soldiers, based on endurance-related genetic markers ACE I/D, ACTN3 Arg (R)577Ter(X), CKMM A/G NcoI and eNOS Glu(G)298Asp(T).

Methods

Genotypic and allelic frequencies were determined in 374 male Gorkha soldiers (Tibeto-Burman). These frequencies were compared with frequencies obtained from Gorkha (Indo-Aryan), high-altitude natives (Tibeto-Burman) and Indian lowlanders (Indo-Aryan). “Total genotype score” (TGS) was calculated from accumulated combination of polymorphisms with maximum value “100” for theoretically “optimal” polygenic score. Probability of occurrence of “optimal” endurance profile was also determined.

Results

ACE II genotypic frequency was highest in Tamangs followed by Gurungs, Rais, Limbus and Magars. No statistical difference in genotypic and allelic frequency of ACTN3 Arg(R)577Ter(X) was noted within the groups. Rais showed the highest CKMM A allele frequency (0.908) compared to other Gorkha (Tibeto-Burman) groups. Limbus and Tamangs showed the highest eNOS G allele frequency (0.938 and 0.915, respectively) compared to that of other groups. Probability of male Gorkha soldiers possessing a theoretically optimal polygenic endurance profile for four candidate polymorphisms was ~3.35% (1 in 30). Four percent of the population of male Gorkha soldiers (15 in 374) exhibited an optimal TGS 100, and 16% exhibited TGS 87 for endurance compared to male Indian soldiers belonging to the lowland (Indo-Aryan) and Gorkha (Indo-Aryan) populations suggesting an overall more “favourable” polygenic profile in the male Gorkha soldier (Tibeto-Burman) population.

Conclusions

This study presents evidence of higher frequency of endurance-associated genes in the Gorkhas implying thereby that such genetically endowed individuals from the population may be selected and trained for achieving excellence in endurance-related elite sports activities.

Electronic supplementary material

The online version of this article (doi:10.1186/s40798-017-0085-0) contains supplementary material, which is available to authorized users.

Association of eNOS and Cav-1 gene polymorphisms with susceptibility risk of large artery atherosclerotic stroke

Endothelial nitric oxide synthase (eNOS) is localized in caveole and has important effects on caveolar coordination through its interaction with caveolin-1 (Cav-1), which supports normal functioning of vascular endothelial cells. However, the relationship between genotypic polymorphisms of e-NOS and Cav-1 genes and ischemic stroke (IS) remains lesser reported. This hospital-based case-control study aimed to determine the genetic polymorphisms of the eNOS (Glu298Asp) and Cav-1 (G14713A and T29107A) genes in association with susceptibility risk in patients who had suffered from a large artery atherosclerotic (LAA) stroke. Genotyping determination for these variant alleles was performed using the TaqMan assay. The distributions of observed allelic and genotypic frequencies for the polymorphisms were in Hardy-Weinberg equilibrium in healthy controls. The risk for an LAA stroke in the Asp298 variant was 1.72 (95% CI = 1.09–2.75) versus Glu298 of the eNOS. In the GA/AA (rs3807987) variant, it was 1.79 (95% CI = 1.16–2.74) versus GG and in TA/AA (rs7804372) was 1.61 (95% CI = 1.06–2.43) versus TT of the Cav-1, respectively. A tendency toward an increased LAA stroke risk was significant in carriers with the eNOS Glu298Asp variant in conjunction with the G14713 A and T29107A polymorphisms of the Cav-1 (aOR = 2.03, P-_trend = 0.002). A synergistic effect between eNOS and Cav-1 polymorphisms on IS risk elevation was significantly influenced by alcohol drinking, heavy cigarette smoking (P-_trend<0.01), and hypercholesterolemia (P-_trend < 0.001). In conclusion, genotypic polymorphisms of the eNOS Glu298Asp and Cav-1 14713A/29107A polymorphisms are associated with the elevated risk of LAA stroke among Han Chinese in Taiwan.

Endothelial nitric oxide synthase gene polymorphisms and the risk of hypertension in an Indian population

Genetic variants of eNOS gene play a significant role in the pathogenesis of hypertension. Many environmental factors have, also, been implicated in the aetiology of hypertension. We carried out an age-matched case-control study among adults. Hypertension was defined according to JNC-VII criteria and eNOS gene polymorphisms were determined by PCR and PCR followed by PCR-RFLP. eNOS intron 4 aa genotype (adjusted OR 6.81; 95% CI 2.29–20.25) and eNOS 894TT genotype (adjusted OR 7.84; 95% CI 2.57–23.96) were associated with the risk of hypertension. Tobacco users (either smoking/chewing or both) with eNOS intron 4 aa genotype (OR 14.00: 95% CI 1.20–163.37), eNOS 894GG genotype (OR 5.56: 95% CI 3.72–8.31), and eNOS T-786C CC genotype (OR 9.00: 95% CI 1.14–71.04) were at an increased risk of hypertension. Similarly a significant gene-environment interaction was observed between individuals consuming alcohol with eNOS intron 4 aa genotype (OR 12.00: 95% CI 1.20–143.73) and eNOS 894GG genotype (OR 1.95: 95% CI 1.35–2.81). The present study identified few susceptible genotypes of the eNOS gene with the risk of hypertension. Moreover, the interactive effects between the environmental factors and the risk of hypertension were dependent on the eNOS genotypes.

Prevalence of endothelial nitric oxide synthase E298D polymorphism in Turkish patients with essential hypertension

AIMS

Our aim was to evaluate the effects of endothelial nitric oxide synthase (eNOS) E298D polymorphism in obesity variables and essential hypertension (eHT) development risk. The genotype frequencies of E298D polymorphism in eHT patients and non-hypertensive (non-HT) controls (proven to have normal coronaries angiographically) were analyzed for their association with demographic and obesity related data of the eHT patients and controls.

MATERIALS AND METHODS

eNOS gene E298D genotypes were determined with qPCR.

RESULTS

The eNOS E298D polymorphism frequencies for 298E/E, 298E/D and 298D/D genotypes were respectively as 41.1%, 44.6%, 14.3% in subjects eHT and 52.8%, 38.9%, 8.3% in the non-HT groups. The combined E298D homozygous polymorphic and heterozygous genotypes were found to have a decreasing effect on serum total-cholesterol levels in comparison to wild-type genotypes in eHT patients but not controls.

CONCLUSIONS

Our results support the idea that, the eNOS E298D polymorphism, which is not associated with hypertension, may increase the risk of hypertension when associated with high serum total-cholesterol levels.

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.

Polymorphisms of genes related to endothelial cells are associated with primary biliary cirrhosis patients of Cretan origin

BACKGROUND

Primary biliary cirrhosis (PBC) is an organ specific autoimmune disease of still unidentified genetic etiology. We have shown that endothelins (ETs), produced by the liver endothelial cells are increased in PBC and may play a major pathogenetic role.

AIMS

To study gene polymorphisms related to the endothelial cells (eNOS, EDN-1 genes) and, to investigate whether the previously reported association of CTLA4 gene polymorphisms is replicated in a genetically homogeneous Greek population.

PATIENTS AND METHODS

Genomic DNA was extracted from 100 PBC patients (83 females, 93% AMA+, 74/100 Ludwig stage I-II) and 158 healthy controls. eNOS, CTLA4 and ET1 polymorphisms were determined by PCR-RFLPs analysis.

RESULTS

Both eNOS intron4 VNTR and eNOS exon7 G894T SNP were significantly associated with increased risk in PBC. EDN-11 rs2071942 "A" and rs5370 "T" alleles appeared a tendency for association with disease progression. No association was found between PBC and the CTLA4 SNPs analyzed.

CONCLUSIONS

We demonstrated that eNOS, a gene related to the liver endothelium function is associated with PBC. Contrarily, the important in adaptive immunity gene CTLA4 was not associated with the disease in the homogeneous population analyzed. These results are compatible partially with our previous hypothesis that defects of the liver endothelial system, leading to endothelin overproduction, may be a fundamental early pathogenetic mechanism in PBC.

Endothelial nitric oxide synthase gene polymorphism (G894T) and diabetes mellitus (type II) among South Indians

The objective of the study is to find out whether the endothelial nitric oxide synthase (eNOS) G894T single-nucleotide polymorphism is associated with type 2 diabetes mellitus in South Indian (Tamil) population. A total number of 260 subjects comprising 100 type 2 diabetic mellitus patients and 160 healthy individuals with no documented history of diabetes were included for the study. DNA was isolated, and eNOS G894T genotyping was performed using the polymerase chain reaction followed by restriction enzyme analysis using Ban II. The genotype distribution in patients and controls were compatible with the Hardy-Weinberg expectations (P > 0.05). Odds ratio indicates that the occurrence of mutant genotype (GT/TT) was 7.2 times (95% CI = 4.09–12.71) more frequent in the cases than in controls. Thus, the present study demonstrates that there is an association of endothelial nitric oxide synthase gene (G894T) polymorphism with diabetes mellitus among South Indians.

Endothelial nitric oxide synthase gene Glu298Asp polymorphism in patients with coronary artery disease

BACKGROUND AND OBJECTIVES

Endo-derived nitric oxide (NO) is synthesized from L-arginine by endothelial nitric oxide synthase (NOS3). Since reduced NO synthesis in endothelial cells has been implicated in the development of coronary atherosclerosis, we investigated the association of NOS3 gene polymorphisms and coronary artery disease (CAD) in an Iranian population.

SUBJECTS AND METHODS

We studied the NOS3 gene Glu298Asp polymorphism in 241 CAD patients with positive coronary angiograms (i.e.,> 50% stenosis affecting at least one coronary vessel) in Shahid Rajaee Heart Hospital and 261 control subjects without a history of symptomatic CAD. The NOS3 gene polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism. Lipid profile and other risk factors were also determined.

RESULTS

The genotype frequencies of Glu298Asp polymorphism for Glu/Glu, Glu/Asp, and Asp/Asp were 61.3%, 32.2%, and 6.5%, respectively, in control subjects, and 46.5%, 42.7%, and 10.8% in CAD patients, respectively. The genotype frequencies differed significantly between the two groups (P=.003). The frequencies of the Asp alleles were 32.2% and 22.6% for CAD patients and control subjects, respectively; the difference between the two groups was statistically significant (P=.001; odds ratio=1.6). Plasma lipids, except HDL-C, were also significantly increased in the CAD groups.

CONCLUSION

These results suggest that CAD is associated with Glu298Asp polymorphism of the NOS3 gene in our population and that this polymorphism is an independent risk factor for CAD.

Association of endothelial nitric oxide synthase Glu298Asp, 4b/a, and -786T>C gene variants with diabetic nephropathy

BACKGROUND

Nitric oxide (NO) produced by endothelial NO synthase (eNOS) mediates a wide range of processes, and abnormal NO production mediated diabetes complications, including diabetic nephropathy (DN). In view of their impact on eNOS activity, polymorphisms in eNOS gene were described as candidates for atherosclerosis and DN.

AIMS

We evaluated the association of -786T>C (promoter region), Glu298Asp (Exon 7), and 4b4a (Intron 4) polymorphisms in eNOS gene with Type 2 diabetes mellitus (T2DM) and DN by haplotype analysis.

SUBJECTS AND METHODS

Study subjects comprised 515 DN patients, 402 normoalbuminuric [diabetes with no nephropathy (DWN)] T2DM patients, and 748 healthy subjects. -786T>C and Glu298Asp genotyping were done by PCR-RFLP analysis.

RESULTS

Higher prevalence of mutant Asp298, 4a, and -786C alleles and homozygous Asp298/Asp298 and 4a/4a genotypes were seen in T2DM patients compared to healthy subjects, with increased Asp298/Asp298 seen in DN compared to DWN patients (P<.05). Three-loci haplotype analysis demonstrated significant association between eNOS variants and T2DM, with protective, neutral, T2DM, and DN-susceptible haplotypes identified, the latter including Asp298/4b/-786T and the Asp298/4a/-786C haplotypes that were present at higher frequencies among DN than among DWN patients. Multivariate regression analysis identified only Asp298/4a/-786T haplotype to be associated with DN (P=.047) after controlling for potential covariates.

CONCLUSION

Genetic variation at the eNOS locus is associated with T2DM. It can serve as a useful genetic marker of increased susceptibility to T2DM and its complications, including the risk of nephropathy.

Endothelial nitric oxide synthase gene haplotypes and circulating nitric oxide levels significantly associate with risk of essential hypertension

Nitric oxide (NO), a potent vasodilator, plays a pivotal role in blood pressure regulation. Endothelial NO synthase gene (NOS3) polymorphisms influence NO levels. Here, we investigated the role of the -922A/G, -786T/C, 4b/4a, and 894G/T polymorphisms of the NOS3 and NO(x) levels in 800 consecutive unrelated subjects comprising 455 patients of essential hypertension and 345 controls. The polymorphisms were investigated independently and as haplotypes. Plasma NO(x) levels (nitrate and nitrite) were estimated by the Griess method. Genotype frequencies for the -786T/C, 4b/4a, and 894G/T polymorphisms differed significantly (P<0.001) between patients and controls and were associated with an increased risk of hypertension (OR=2.0, OR=3.8, OR=1.6, respectively). The 4-locus haplotypes ATaG (H1), ATaT (H2), and GCaG (H3) were significantly associated with essential hypertension and served as susceptible haplotypes (P<or=0.0001). On the other hand, haplotypes ATbG (H4) and GTbG (H5) were negatively associated with hypertension and served as protective haplotypes (P<0.0001). NO(x) levels were significantly lower in patients than controls (P<0.0001). The individual polymorphisms showed marginal association with NO(x) level; however, the susceptible haplotype H2 associated significantly with lower NO(x) levels in patients (P<0.001) and conversely the haplotype H4 with higher NO(x) levels in controls (P<0.001). In conclusion, the 4b/4a and likely -786T/C polymorphisms were identified as the determinants modifying the risk of hypertension. This study identifies the NOS3 variants and haplotypes as genetic risk factors and as useful markers of increased susceptibility to the risk of essential hypertension.