Functional Inducible Nitric Oxide Synthase Gene Variants Associate With Hypertension: A Case-Control Study in a Finnish Population-The TAMRISK Study

GETdb: A comprehensive database for genetic and evolutionary features of drug targets

The development of an innovative drug is complex and time-consuming, and the drug target identification is one of the critical steps in drug discovery process. Effective and accurate identification of drug targets can accelerate the drug development process. According to previous research, evolutionary and genetic information of genes has been found to facilitate the identification of approved drug targets. In addition, allosteric proteins have great potential as targets due to their structural diversity. However, this information that could facilitate target identification has not been collated in existing drug target databases. Here, we construct a comprehensive drug target database named Genetic and Evolutionary features of drug Targets database (GETdb, http://zhanglab.hzau.edu.cn/GETdb/page/index.jsp). This database not only integrates and standardizes data from dozens of commonly used drug and target databases, but also innovatively includes the genetic and evolutionary information of targets. Moreover, this database features an effective allosteric protein prediction model. GETdb contains approximately 4000 targets and over 29,000 drugs, and is a user-friendly database for searching, browsing and downloading data to facilitate the development of novel targets.

Single nucleotide polymorphisms in inducible nitric oxide synthase gene are not associated with persistent apical periodontitis

The aim of this study was to investigate whether there is an association between inducible in single nucleotide polymorphisms in nitric oxide synthase (rs2297518 and rs2779249) and persistent apical periodontitis. A total of 291 Brazilian subjects were included: 125 with signs/symptoms of persistent apical periodontitis and 166 with root canal-treated teeth exhibiting healthy perirradicular tissues. Endodontically treated patients were followed up after 1 year. The two single nucleotide polymorphisms in nitric oxide synthase were analysed using real-time polymerase chain reaction. Chi-square test and odds ratio with 95% confidence intervals were performed to compare genotype distributions between 'healed' and 'persistent apical periodontitis' groups (p < 0.05). Logistic regression analysis was used to evaluate SNP-SNP interactions. The allele and genotype distributions for the polymorphisms between the persistent apical periodontitis and healed groups were not statistically significant (p > 0.05). In the logistic regression analysis, the polymorphisms were not associated with persistent apical periodontitis and SNP-SNP interactions.

Association of Single-Nucleotide Polymorphisms Rs2779249 (chr17:26128581 C>A) and Rs rs2297518 (chr17: chr17:27769571 G>A) of the NOS2 Gene with Tension-Type Headache and Arterial Hypertension Overlap Syndrome in Eastern Siberia

Inducible nitric oxide (NO) synthase (iNOS), encoded by the NOS2 gene, promotes the generation of high levels of NO to combat harmful environmental influences in a wide range of cells. iNOS can cause adverse effects, such as falling blood pressure, if overexpressed. Thus, according to some data, this enzyme is an important precursor of arterial hypertension (AH) and tension-type headache (TTH), which are the most common multifactorial diseases in adults. The purpose of this study was to investigate the association of rs2779249 (chr17:26128581 C>A) and rs2297518 (chr17: chr17:27769571 G>A) of the NOS2 gene with TTH and AH overlap syndrome (OS) in Caucasians in Eastern Siberia. The sample size was 91 participants: the first group-30 patients with OS; the second group-30 patients AH; and the third group-31 healthy volunteers. RT-PCR was used for the determination of alleles and genotypes of the SNPs rs2779249 and rs2297518 of the NOS2 gene in all groups of participants. We showed that the frequency of allele A was significantly higher among patients with AH compared with healthy volunteers (p-value < 0.05). The frequency of the heterozygous genotype CA of rs2779249 was higher in the first group vs. the control (p-value = 0.03), and in the second group vs. the control (p-value = 0.045). The frequency of the heterozygous genotype GA of rs2297518 was higher in the first group vs. the control (p-value = 0.035), and in the second group vs. the control (p-value = 0.001). The allele A of rs2779249 was associated with OS (OR = 3.17 [95% CI: 1.31-7.67], p-value = 0.009) and AH (OR = 2.94 [95% CI: 1.21-7.15], p-value = 0.015) risks compared with the control. The minor allele A of rs2297518 was associated with OS (OR = 4.0 [95% CI: 0.96-16.61], p-value = 0.035) and AH (OR = 8.17 [95% CI: 2.03-32.79], p-value = 0.001) risks compared with the control. Therefore, our pilot study demonstrated that the SNPs rs2779249 and rs229718 of the NOS2 gene could be promising genetic biomarkers for this OS risk in Caucasians from Eastern Siberia.

No Association Between Interleukin 6 and Inducible Nitric Oxide Synthase Polymorphisms and Dengue Infection: A Case-Control Study

BACKGROUND

Dengue is a life-threatening disease. The factors that lead to severe cases are not completely understood. The host immune system is involved in the response to infections and plays an important role in dengue infection. IL-6 and iNOS are components of the immune system and genetic polymorphisms in these genes may be involved in dengue virus infection. The study aimed to investigate the association of genetic polymorphisms in the IL6 and iNOS genes and dengue.

METHODS

We performed a case-control study using 60 dengue-infected individuals and 119 healthy controls. Polymorphisms in the IL6 (T15A) and iNOS (-1173CT) genes were amplified by Real-Time PCR. Statistical analyses were performed using BioEstat 5.0.

RESULTS

We identified that the frequency of T/A genotype of IL6 was higher in dengue fever patients and C/T genotype of iNOS was higher in dengue hemorrhagic fever patients, however, no association was found between these polymorphisms and dengue.

CONCLUSION

Polymorphisms in iNOS and IL6 were not associated with dengue infection.

The Role of Single Nucleotide Variants of NOS1, NOS2, and NOS3 Genes in the Development of the Phenotype of Migraine and Arterial Hypertension

Migraine (M) and arterial hypertension (AH) are very common diseases. Today, there are a number of studies confirming and explaining their comorbidity. We searched PubMed, Springer, Scopus, Web of Science, Clinicalkeys, and Google Scholar databases for full-text English publications over the past 15 years using keywords and their combinations. The present review provides a synthesis of information about single nucleotide variants (SNVs) of NOS1, NOS2, and NOS3 genes involved in the development of M and essential AH. The results of studies we have discussed in this review are contradictory, which might be due to different designs of the studies, small sample sizes in some of them, as well as different social and geographical environments. Despite a high prevalence of the M and AH phenotype, its genetic markers have not yet been sufficiently studied. Specifically, there are separate molecular genetic studies aimed to identify SNVs of NOS1, NOS2, and NOS3 genes responsible for the development of M and those responsible for the development of AH. However, these SNVs have not been studied in patients with the phenotype of M and AH. In this review, we identify the SNVs that would be the most interesting to study in this aspect. Understanding the role of environmental factors and genetic predictors will contribute to a better diagnostics and exploration of new approaches to pathogenetic and disease-modifying treatment of the M and AH phenotype.

The Role of Single-Nucleotide Variants of NOS1, NOS2, and NOS3 Genes in the Comorbidity of Arterial Hypertension and Tension-Type Headache

Patients with tension-type headache (TTH) have an increased risk of developing arterial hypertension (AH), while hypertensive subjects do seem to have an increased risk of TTH. We searched for full-text English publications in databases using keywords and combined word searches over the past 15 years. In addition, earlier publications of historical interest were included in the review. In our review, we summed up the single nucleotide variants (SNVs) of Nitric Oxide Synthases (NOSs) genes involved in the development of essential AH and TTH. The results of studies we discussed in this review are contradictory. This might be due to different designs of the studies, small sample sizes in some of them, as well as different social and geographical characteristics. However, the contribution of genetic and environmental factors remains understudied. This makes the issue interesting for researchers, as understanding these mechanisms can contribute to a search for new approaches to pathogenetic and disease-modifying treatment of the AH and TTH phenotype. New drugs against AH and TTH can be based on inhibition of nitric oxide (NO) production, blockade of steps in the NO-cGMP pathway, or NO scavenging. Indeed, selective neuronal NOS (n-NOS) and inducible NOS (i-NOS) inhibitors are already in early clinical development.

Association between Genetic Variants in NOS2 and TNF Genes with Congenital Zika Syndrome and Severe Microcephaly

Zika virus (ZIKV) causes Congenital Zika Syndrome (CZS) in individuals exposed prenatally. Here, we investigated polymorphisms in VEGFA, PTGS2, NOS3, TNF, and NOS2 genes as risk factors to CZS. Forty children with CZS and forty-eight children who were in utero exposed to ZIKV infection, but born without congenital anomalies, were evaluated. Children with CZS were predominantly infected by ZIKV in the first trimester (p < 0.001) and had mothers with lower educational level (p < 0.001) and family income (p < 0.001). We found higher risk of CZS due the allele rs2297518[A] of NOS2 (OR = 2.28, CI 95% 1.17–4.50, p = 0.015). T allele and TT/CT genotypes of the TNF rs1799724 and haplotypes associated with higher expression of TNF were more prevalent in children with CZS and severe microcephaly (p = 0.029, p = 0.041 and p = 0.030, respectively). Our findings showed higher risk of CZS due ZIKV infection in the first trimester and suggested that polymorphisms in NOS2 and TNF genes affect the risk of CZS and severe microcephaly.

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.

The Role of Inducible NOS2 Gene Polymorphism in the Development of Essential Arterial Hypertension

The risk of essential arterial hypertension was assessed in carriers of the NOS2 gene variants (rs1800482 (-954G>C), rs3730017 (C>T)). In subjects carrying C allele (rs1800482), the risk for essential arterial hypertension developing was higher by 1.7 times (OR=1.712, 95%CI 1.07-2.74), while the presence of T-allele (rs3730017) had a protective effect (OR=0.304, 95%CI 0.192-0.482). In patients with essential arterial hypertension, the presence of the C allele (rs1800482) was associated with a higher content of NO metabolites in the blood plasma. A positive correlation was found between the plasma content of nitrites and nitrates and the level of transcripts of VCAM1, ICAM1 genes in peripheral blood leukocytes. We found the influence of the C allele carriership on the expression VCAM1 and ICAM1 genes in patients with essential hypertension. It was hypothesized that this polymorphic site in the NOS2 gene can be involved in the development of endothelial dysfunction and essential arterial hypertension through modulation of NO level under condition of inflammation.

Variability within the human iNOS gene and Achilles tendon injuries: Evidence for a heterozygous advantage effect

OBJECTIVES

The aim of this case control genetic association study was to explore whether two variants within the inducible nitric oxide synthase (iNOS) gene, rs2779249 (C/A) and rs2248814 (A/G), influenced the risk of Achilles tendinopathy in a British population.

DESIGN

Candidate gene, case control association study.

METHOD

We recruited 145 individuals diagnosed with Achilles tendon pathology and 132 asymptomatic controls. All participants were genotyped for the iNOS variants using qPCR and significant associations were discovered using a combination of Chi squared and ANOVA type analysis.

RESULTS

The CA genotype of the iNOS rs2779249 variant was protective and conformed to a heterozygous advantage model of inheritance as it was overrepresented in the control participants (p=0.009). In sex specific analysis the protective association persisted in male participants (p=0.016) but not in females. Unlike the rs2779249 variant, the rs2248814 variant was not associated with Achilles tendinopathy or Achilles tendon rupture.

CONCLUSION

The rs2779249 CA genotype within the human iNOS gene appears to protect individuals from Achilles tendinopathy. This study further supports a genetic contribution to modifying the risk of Achilles tendon problems. The study also infers an important role for nitric oxide in tendon healing and/or degradation.

Circulating nitric oxide metabolites and the risk of cardiometabolic outcomes: a prospective population-based study

Aim: This study was conducted to investigate whether serum NO metabolites (NOx) could predict the occurrence of type 2 diabetes (T2DM), hypertension (HTN) and metabolic syndrome (MetS). Methods: We measured serum NOx concentrations in the Tehran Lipid and Glucose Study participants (aged ≥19 years) and followed them for a median of 7.7 years for the incidence of outcomes. To determine the appropriate cut-off points of serum NOx for predicting clinical events, a random sampling method (50:50 ratio) was used for the population and for analysis, receiver operator characteristic curve was used. Multivariable Cox proportional hazard models were used to estimate the hazard ratios (HRs) with 95% confidence intervals (95% CIs) of T2DM, HTN and MetS in response to serum NOx values. Results: The optimal cut-off points of serum NOx levels for predicting T2DM, HTN and MetS were 26.5, 25.5 and 25.5 µmol/L, respectively. Participants with serum NOx levels ≥25.5 µmol/L had increased risk of MetS (HR = 1.31, 95% CI = 1.01-1.72). No evidence was found for any association of serum NOx with incidence of T2DM and HTN (HR = 1.03, 95% CI = 0.83-1.77 and HR = 1.09, 95% CI = 0.88-1.35). Conclusion: In this prospective population-based investigation, a higher circulating NOx was associated with development of MetS.

Relationship between inducible NOS single-nucleotide polymorphisms and hypertension in Han Chinese

BACKGROUND

Inducible nitric oxide synthase (iNOS) single-nucleotide polymorphisms have been reported to confer susceptibility to hypertension, but no consensus has been reached. The aim of this study was to investigate the association between iNOS and hypertension in a Chinese population.

METHODS

This was a case-control study including 1172 hypertensive and 1172 control subjects to investigate the association between iNOS and hypertension.

RESULTS

There were significant differences in the distribution of genotype and allele frequencies of rs2779249 and rs2297518 between hypertensive and normotensive subjects. Logistic regression analyses were performed with different genetic models (additive, dominant, recessive) adjusting for confounding risk covariates, including age, sex, body mass index, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, smoking, drinking, and family history of hypertension. The odds ratio (OR) was 1.27 (1.12, 1.44) in the additive model, 1.31 (1.09, 1.59) in the dominant, and 1.68 (1.28, 2.19) in the recessive model of rs2779249; the OR was 1.26 (1.06, 1.50) in the additive model and 1.46 (1.13, 1.89) in the dominant model of rs2297518.

CONCLUSION

The current study provides evidence that iNOS is strongly associated with hypertension.

Inducible Nitric Oxide Synthase Polymorphisms and Nitric Oxide Levels in Individuals with Chronic Periodontitis

This study aimed to investigate whether the -1026(A>C)(rs2779249) and +2087(A>G)(2297518) polymorphisms in the NOS2 gene were associated with chronic periodontitis (CP) and with salivary levels of nitrite (NO₂^-) and/or nitrate + nitrite (NOx). A group of 113 mixed-race patients were subjected to periodontal, genetic, and biochemical evaluations (65 CP/48 periodontally healthy subjects). DNA was extracted from oral epithelial cells and used for genotyping by polymerase chain reaction (real-time). Salivary NOx concentrations were determined using an ozone-based chemiluminescence assay. Association of CP with alleles and genotypes of the -1026(A>C) polymorphism was found (X² test, p = 0.0075; 0.0308), but this was not maintained after multiple logistic regression, performed to estimate the effect of covariates and polymorphisms in CP. This analysis demonstrated, after correction for multiple comparisons, that only the female gender was significantly associated with CP. Polymorphisms analyzed as haplotypes were not associated with CP. NOx levels were significantly higher in the control group of heterozygous individuals for both polymorphisms. In conclusion, the female gender was significantly associated with CP, and higher levels of salivary NOx were found in control subjects and associated with the heterozygous state of the NOS2 polymorphisms, reinforcing the potential of NO metabolites as markers of periodontitis status.

Angiogenesis-related genes and thalidomide teratogenesis in humans: an approach on genetic variation and review of past in vitro studies

Thalidomide embryopathy (TE) has affected more than 10,000 babies worldwide. The hypothesis of antiangiogenesis as the teratogenic mechanism of thalidomide has been investigated in several experimental models; but, in humans, it has only been accessed by in vitro studies. Here, we hypothesized the effect of thalidomide upon angiogenesis-related molecules or proteins, previously identified in human embryonic cells, through the in silico STRING-tool. We also investigated ten polymorphisms in angiogenesis-related genes in 38 Brazilian TE individuals and 136 non-affected Brazilians. NOS2, PTGS2, and VEGFA polymorphisms were chosen for genotyping. The STRING-tool suggested nitric oxide and β-catenin as the central angiogenesis-related molecules affected by thalidomide's antiangiogenic property. We did not identify a significant difference of allelic, genotypic or haplotypic frequencies between the groups. We could not predict a risk allele or a protective one for TE in NOS2, PTGS2, or VEGFA, although other genes should be analyzed in larger samples. The role of nitric oxide and β-catenin must be further evaluated, regarding thalidomide teratogenesis complex etiology.