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

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.

How Does Mental Health Impact Women's Heart Health?

From adolescence until old age, women are more vulnerable to common mental disorders (CMDs; depression and anxiety) than men at all stages of the life course. By middle age, women who have clinical depression are at twice the risk of having an incident cardiovascular disease (CVD) than those without. This has important implications for the way we prevent, identify and treat both CMDs and coronary heart disease in women. In this paper, we discuss the various genetic, biological, ethnic/racial, and psychological pathways by which women's vulnerability to CMDs elevate their CVD risk and recovery from a cardiac event. We review the evidence from trials that have, to date, failed to show that treating depression can reduce or delay the onset or recurrence of CVD events, especially for female patients. We discuss the value of lifestyle-based therapies for treating depression, to which women may be more responsive, and finish by discussing how population-based approaches including risk factor assessment could be tailored to consider these factors.

Association of SGK1 Polymorphisms With Susceptibility to Coronary Heart Disease in Chinese Han Patients With Comorbid Depression

There is a strong link between heart disease and depression, both of which are closely related to lifetime stress exposure. Serum/glucocorticoid-regulated kinase 1 (SGK1) is a stress-responsive gene with a pivotal role in both the heart and brain. To determine the role of SGK1 polymorphisms (rs2758151, rs1743963, rs9493857, rs1763509, rs9376026, and rs9389154) in susceptibility to comorbid coronary heart disease (CHD) and depression, we conducted a hospital-based case–control study involving 257 CHD cases (including 69 cases with depression and 188 cases without depression) and 107 controls in a Chinese Han population. Six single-nucleotide polymorphisms (SNPs) in the SGK1 gene were successfully genotyped by polymerase chain reaction–ligase detection reaction (PCR-LDR) assay. Our results showed no significant differences in SGK1 genetic polymorphisms between CHD patients and controls, whereas significant associations were observed between SGK1 SNPs (rs1743963 and rs1763509) and the development of depression in CHD patients (P = 0.018 by genotype, P = 0.032 by allele; P = 0.017 by genotype, P = 0.003 by allele, respectively). However, none of these associations remained significant after Bonferroni correction (P = 0.054 for rs1743963; P = 0.051 for rs1763509). Interestingly, both the GG genotype of SGK1 rs1743963 and AA genotype of SGK1 rs1763509 were associated with a higher risk of depression in CHD patients; for rs1763509, the Patient Health Questionnaire-9 (PHQ-9) scores in the carriers of the risk genotype for comorbid depression, AA, were significantly higher than in GG and AG carriers (P = 0.008). Notably, haplotype analysis indicated that haplotype GGA significantly increased the risk of depression in CHD patients (P = 0.011, odds ratio (OR) = 1.717, 95% confidence interval (CI) = 1.132–2.605), whereas haplotype AAG may be a protective factor for CHD patients with comorbid depression (P = 0.038, OR = 0.546, 95% CI = 0.307–0.972). It should be noted that only the significance of haplotype GGA survived after Bonferroni adjustment (P = 0.044) and that no significant differences were found for other SGK1 SNPs (rs2758151, rs9493857, rs9376026, and rs9389154) between CHD patients with and without depression. These findings, for the first time, elucidate the important role of SGK1 variants in the comorbidity of CHD and depression.

Common Variations in Prothrombotic Genes and Susceptibility to Ischemic Stroke in Young Patients: A Case-Control Study in Southeast Iran

Background and Objective: Evidence indicates that genetic factors may be involved in the risk of ischemic stroke (IS). The aim of this study was to assess the effect of genetic polymorphisms located in exons or untranslated regions of MTHFR as well as FV genes on ischemic stroke. Materials and Methods: In this case-control study, 106 patients with IS and 157 healthy volunteers (age <50 years) were genotyped for MTHFR C677T, A1298C, C2572A and C4869G, FVL, and prothrombin G20210A polymorphisms. Results: The MTHFR 677CT genotype was more frequent in patients and increased risk of IS with Odds Ratio = 1.9. The MTHFR A1298C and C2572A polymorphisms were not associated with IS in dominant and recessive models. Our findings showed a significant decrease in the MTHFR4869CG genotype in IS patients, and this variant was associated with a decreased risk of IS in the dominant model. The CAAT haplotype was associated with increased risk, and the GAAC haplotype was associated with decreased risk of IS compared to other haplotypes. There was no relation between FVL G1691A polymorphism and IS risk. Conclusions: The present study showed that the MTHFR 677CT genotype was more frequent and the MTHFR 4869CG genotype was less frequent in young IS patients.

The contribution of NOS3 variants to coronary artery disease: A combined genetic epidemiology and computational biochemistry perspective

Cardiovascular diseases, particularly coronary artery disease (CAD) and myocardial infarction, are the leading cause of death among people worldwide. CAD is exceedingly complex in its interplay of environment and genetics, with numerous genetic loci contributing to its heritability. Here, we aim at looking into the effects of the NOS3 c.894G>T and 27-bp VNTR polymorphisms on susceptibility to CAD in a population of Turkish Cypriots, at seeing whether these effects correlate with plasma lipid levels and at predicting the functional consequences of each polymorphism tested. A total of 50 subjects with CAD and 100 otherwise healthy subjects were included in the present case-control study. Genomic DNA was extracted from peripheral blood samples, and the two NOS3 polymorphisms were determined by restriction endonuclease analysis of PCR amplicons. Complementary methods of statistical analysis and computational modeling were employed accordingly to achieve the aims above. Our findings show that the 27-bp VNTR polymorphic locus, but not the c.894G>T polymorphic locus, is associated with CAD and that it may regulate NOS3 pre-mRNA splicing in a length-dependent manner. Overall, along with additional, yet-to-be ascertained susceptibility markers the 27-bp VNTR 4a/4b marker may be employed in risk stratification in community-level screening for CAD among Turkish Cypriots.

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

Background:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

Oleanolic acid ameliorates high glucose-induced endothelial dysfunction via PPARδ activation

Oleanolic acid (3β-hydroxyolean-12-en-28-oic acid, OA) is a pentacyclic triterpenes widely distributed in food, medicinal plants and nutritional supplements. OA exhibits various pharmacological properties, such as hepatoprotective and anti-tumor effects. In this study, we analyzed the effect of OA on endothelial dysfunction induced by high glucose in human vascular endothelial cells (ECs). Western blotting showed that OA attenuated high glucose-reduced nitric production oxide (NO) as well as Akt-Ser⁴⁷³ and eNOS-Ser¹¹⁷⁷ phosphorylation in cultured human umbilical vein ECs (HUVECs). Next, luciferase reporter assay showed that OA activated peroxisome proliferators-activated receptor δ (PPARδ) activity. Quantitative reverse transcriptase PCR (qRT-PCR) demonstrated that OA increased the expressions of PPARδ target genes (PDK4, ADRP and ANGPTL4) in ECs. Meanwhile, the induced expressions of PDK4, ADRP and ANGPTL4 by OA were inhibited by GSK0660, a specific antagonist of PPARδ. In addition, inhibition of PPARδ abolished OA-induced the Akt-Ser⁴⁷³ and eNOS-Ser¹¹⁷⁷ phosphorylation, and NO production. Finally, by using Multi Myograph System, we showed that OA prevented high glucose-impaired vasodilation. This protective effect on vasodilation was inhibited in aortic rings pretreated with GSK0660. Collectively, we demonstrated that OA improved high glucose-impaired endothelial function via a PPARδ-mediated mechanism and through eNOS/Akt/NO pathway.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

Age and gender differences in the influences of eNOS T-786C polymorphism on arteriosclerotic parameters in general population in Japan

OBJECTIVE

The influence of T-786C polymorphism in the promoter region of endothelial nitric oxide synthase (eNOS) on arteriosclerotic parameters by age and gender were examined.

METHODS

Brachial-ankle pulse wave velocity (baPWV), heart-rate adjusted augmentation index (AIx@75), pulse pressure (PP) and albumin-creatinine ratio (ACR) were assessed as arteriosclerotic parameters in addition to non-high-density lipoprotein cholesterol (non-HDL-C) to HDL-C (non-HDL-C/HDL-C) ratio in 1499 participants. T-786C polymorphism (rs2070744) was screened using a TaqMan allelic discrimination assay. Analyses of covariance were carried.

RESULTS

Women with the non-C allele showed significantly lower AIx@75 in participants aged <65 years and baPWV in participants aged ≥65 years than those with C allele. In contrast, men with the non-C allele showed significantly higher PP in participants aged <65 years, and higher ACR and non-HDL-C/HDL-C ratio in participants aged ≥65 years. In men on cholesterol-lowering medication, the non-C allele carriers showed significantly higher non-HDL-C compared to those in the C allele carriers.

CONCLUSIONS

eNOS T-786C polymorphism is significantly associated with arteriosclerotic parameters accompanied with age and gender differences, possibly involving antioxidative and/or endothelial signaling other than inflammatory signaling.

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).

Short- and long-term treatment with folic acid suppresses thrombus formation in atherogenic mice in vivo

In the present study, we examined the effects of short- and long-term treatment with folic acid (FA) on thrombus formation in vivo in atherogenic mice to explore a novel agent for the prevention of atherothrombotic disease. Apolipoprotein E and low-density lipoprotein receptor double deficient (ApoE(-/-)LDLR(-/-)) mice were orally administrated a single bolus of FA (20mg/kg) or fed an atherogenic diet with or without FA (0.02, 0.5, and 1.5mg/kg) for 12 weeks. Thrombus formation and endothelial function were assessed in vivo using the He-Ne laser-induced carotid artery thrombus formation test and the flow-mediated vasodilation method. Platelet reactivity was assessed ex vivo using haemostatometry. Short-term treatment with FA markedly increased plasma folate levels and significantly suppressed laser-induced thrombus formation in apoE(-/-)LDLR(-/-) mice. Short-term treatment with FA suppressed platelet reactivity in apoE(-/-)LDLR(-/-) mice, but FA treatment did not affect endothelial function or plasma homocysteine levels. Long-term treatment with FA increased plasma folate levels dose-dependently. Thrombus formation and endothelial dysfunction were suppressed by treatment with 0.5 and 1.5mg/kg of FA, respectively, but not with 0.02mg/kg of FA, whereas platelet reactivity was not altered by treatment with any dose of FA. Long-term treatment with all doses of FA decreased the plasma homocysteine levels in apoE(-/-)LDLR(-/-) mice, although this result was not consistent with its anti-thrombotic action. In conclusion, our data showed that short- and long-term treatment with FA could suppress in vivo thrombus formation in an atherogenic setting, independent of its hypohomocysteinemic action.