NOS2A Gene Research Articles

Association of NOS2A gene polymorphisms with susceptibility to bovine tuberculosis in Chinese Holstein cattle.

Bovine tuberculosis (bTB) is a global zoonotic disease that has detrimental economic impacts worldwide. The NOS2A gene plays a key role in immunological control of many infectious diseases. However, research on the association between NOS2A polymorphisms and bTB infection in Holstein cattle reared on the Yunnan-Guizhou plateau of China is scarce. This study investigated a possible linkage between NOS2A polymorphisms and risk of developing bTB in Chinese Holstein cattle. The NOS2A gene was genotyped in 144 bTB-infected Holstein cows and 139 healthy controls were genotyped through nucleotide sequencing. Ten single-nucleotide polymorphisms (SNPs) were detected, six of which were associated with susceptibility/resistance patterns of bTB. Furthermore, the C/T genotypes of 671 and 2793, and T/T genotype of E22 (+15) were significantly associated with susceptibility risk; the G/A genotype of 2857, T/T genotype of E9 (+65), and C/C genotype of E9 (+114) probably increased resistance to bTB. In addition, the haplotypes of NOS2A-2 and NOS2A-9 were risk factors for bTB susceptibility, while the NOS2A-5 and NOS2A-8 haplotypes were contributing protective variants against tuberculosis. There is a significant association between variation in SNPs of NOS2A and tuberculosis susceptibility/resistance pattern. These findings suggest that substitution of genetic selection would be helpful for eradicating bTB. However, further investigation is required to study the underlying mechanism through which NOS2A polymorphisms affect bTB infection.

Epigenetic Insights and Potential Modifiers as Therapeutic Targets in β-Thalassemia.

Thalassemia, an inherited quantitative globin disorder, consists of two types, α– and β–thalassemia. β–thalassemia is a heterogeneous disease that can be asymptomatic, mild, or even severe. Considerable research has focused on investigating its underlying etiology. These studies found that DNA hypomethylation in the β–globin gene cluster is significantly related to fetal hemoglobin (HbF) elevation. Histone modification reactivates γ-globin gene expression in adults and increases β–globin expression. Down-regulation of γ–globin suppressor genes, i.e., BCL11A, KLF1, HBG-XMN1, HBS1L-MYB, and SOX6, elevates the HbF level. β–thalassemia severity is predictable through FLT1, ARG2, NOS2A, and MAP3K5 gene expression. NOS2A and MAP3K5 may predict the β–thalassemia patient’s response to hydroxyurea, a HbF-inducing drug. The transcription factors NRF2 and BACH1 work with antioxidant enzymes, i.e., PRDX1, PRDX2, TRX1, and SOD1, to protect erythrocytes from oxidative damage, thus increasing their lifespan. A single β–thalassemia-causing mutation can result in different phenotypes, and these are predictable by IGSF4 and LARP2 methylation as well as long non-coding RNA expression levels. Finally, the coinheritance of β–thalassemia with α–thalassemia ameliorates the β–thalassemia clinical presentation. In conclusion, the management of β–thalassemia is currently limited to genetic and epigenetic approaches, and numerous factors should be further explored in the future.

Association of Polymorphisms in the Promoter Region of NOS2A Gene with Primary Knee Osteoarthritis in the Greek Population.

IntroductionA new emerging role of nitric oxide (NO) in the aetiology of osteoarthritis (OA) has been reported. Inducible NO synthase (iNOS), produced by chondrocytes, is the major source of NO in the osteoarthritic cartilage. The aim of this study is to evaluate the potential association between the -1173C/T (rs9282799), -1026 C/A (rs 2779249) and -954G/C (rs1800482) single nucleotide polymorphisms (SNPs) in the promoter of the iNOS gene (NOS2A) and the incidence of knee OA in Greek population.MethodsNinety-six patients with primary knee OA were included in the study along with 44 controls. Genotypes were identified using polymerase chain reaction (PCR) and DNA sequencing techniques. Allelic and genotypic frequencies were compared between patients and controls.ResultsNone of the -1173C/T, -1026 C/A and -954G/C SNPs were detected in the studied population, either in patients or controls. However, another SNP was identified at the site -1056 at the promoter region, where the initial G allele was substituted by the T allele. Interestingly, the TT genotype was completely absent in controls, but was detected in six patients with a 6.2% observed frequency. The difference between patients and controls was not statistically significant (p-value = 0.18). In male OA patients, the observed frequency of the TT genotype was higher (28.6%) in comparison to the 0% of the male controls (p-value = 0.1). The frequency of the G allele was 0.82 in controls and 0.78 in OA patients (p-value = 0.53).ConclusionsThe present study demonstrates that the 954G/C, -1026C/A, -1056G/T and -1173C/T SNPs of the NOS2A gene are not a risk factor for primary knee OA in Greek population. Moreover, -954G/C, -1026C/A and -1173C/T are rare, if not completely absent, in the Greek population. Additional research is mandatory in order to investigate the association of these SNPs with OA in different ethnic populations.

The effects of fine particulate matter constituents on exhaled nitric oxide and DNA methylation in the arginase–nitric oxide synthase pathway

BackgroundFine particulate matter (PM2.5) has been widely associated with airway inflammation represented by increased fractional concentration of exhaled nitric oxide (FeNO). However, it remains unclear whether various PM2.5 constituents have different impacts on FeNO and its production process from the arginase (ARG)–nitric oxide synthase (NOS) pathway. ObjectivesTo investigate the acute effects of PM2.5 constituents on FeNO and DNA methylation of genes involved. MethodsWe conducted a longitudinal panel study among 43 young adults in Shanghai, China from May to October in 2016. We monitored the concentrations of 25 constituents of PM2.5. We applied the linear mixed-effect model to evaluate the associations of PM2.5 constituents with FeNO and DNA methylation of the ARG2 and NOS2A genes. ResultsFollowing PM2.5 exposure, NOS2A methylation decreased and ARG2 methylation increased only on the concurrent day, whereas FeNO increased most prominently on the second day. Nine constituents (OC, EC, K, Fe, Zn, Ba, Cr, Se, and Pb) showed consistent associations with elevated FeNO and decreased NOS2A methylation or increased ARG2 methylation in single-constituent models and models adjusting for PM2.5 total mass and collinearity. An interquartile range increase of these constituents was associated with respective decrements of 0.27–1.20 in NOS2A methylation (%5mC); increments of 0.48–1.56 in ARG2 methylation (%5mC); and increments of 7.12%–17.54% in FeNO. ConclusionsOur results suggested that OC, EC, and some metallic elements may be mainly responsible for the development and epigenetic regulation of airway inflammatory response induced by short-term PM2.5 exposure.

Role of Genomic Biomarkers in Increasing Fetal Hemoglobin Levels Upon Hydroxyurea Therapy and in β-Thalassemia Intermedia: A Validation Cohort Study

Hemoglobinopathies exhibit a remarkable phenotypic diversity in terms of disease severity, while individual genetic background plays a key role in differential response to drug treatment. In the last decade, genomic variants in genes located within, as well as outside the human β-globin cluster have been shown to be significantly associated with Hb F increase, in relation to hydroxyurea (HU) therapy in patients with these diseases. Here, we aim to determine the effect of genomic variants located in genes, such as MAP3K5, ASS1, NOS2A, TOX, PDE7B, NOS1, FLT1 and ARG2, previously shown to modulate fetal hemoglobin (Hb F) levels in patients with β type hemoglobinopathies and reflecting disease severity and response to HU therapy in an independent cohort of Greek patients with these diseases. We recruited and genotyped 45 β-thalassemia patients (β-thal), either transfusion-dependent (TDT) or non transfusion-dependent (NTDT), 42 Hb S (HBB: c.20A>T)-β-thal compound heterozygotes, who were treated with HU, as well as 53 healthy individuals, all of Hellenic origin. Our study showed that genomic variants of the MAP3K5, NOS2A and ARG2 gene are associated with HU therapy efficacy in Hb S-β-thal compound heterozygotes. We have also shown that FLT1 and ARG2 genomic variants are associated with the mild phenotype of NTDT patients. Our findings provide evidence that MAP3K5, NOS2A, ARG2 and FLT1 genomic variants could be considered as genomic biomarkers to predict HU therapy efficacy in Hb S-β-thal compound heterozygotes and also to describe disease severity in patients with β type hemoglobinopathies.

POLYMORPHISM IN THE INDUCIBLE NITRIC OXIDE SYNTHASE GENE INPATIENT SUSCEPTIBILITY SPINAL TUBERCULOSIS

Spinal Tuberculosis is an infection of the spine caused by Mycobacterium Tuberculosis. It is an extrapulmonary complication of Mycobacterium Tuberculosis infection. The purpose of this study was to determine whether there is a NOS 2A gene polymorphism so that patients are susceptible to tuberculosis spondylitis. This study is an analytical cross-sectional study on 36 Spinal tuberculosis patients at the Wahidin Sudirohusodo Hospital in Makassar who had tested positive TB geneXpert and took 5 ml of blood samples in EDTA tubes. Then DNA extraction and genotyping examination with PCR techniques were carried out. There were 39 subjects in this study 39 TB spondylitis patients (84.8%) and 7 controls (15.2%). Most of them were women (58.7%), aged between 20-29 years (41.3%). Based on PCR results, only 2 subjects experienced a gene mutation (4.3%) in the A-277G single nucleotide. The NOS2A gene polymorphism is a cause of susceptibility to spinal tuberculosis.

Association Between rs3833912/rs16944 SNPs and Risk for Cerebral Palsy in Mexican Children

Perinatal asphyxia in the neonatal brain triggers a robust inflammatory response in which nitric oxide (NO) generation plays a hazardous role. Increased levels of NO can be maintained by the activity of inducible NO synthase (NOS2A) on its own or activated by IL-1beta (IL-1β) gene transcription and positive back stimulation of the NOS2 (CCTTT)n microsatellite by IL-1β, thus potentiating brain injury after ischemic perinatal asphyxia. We investigated whether the risk for cerebral palsy (CP) increases when an expansion of the − 2.5 kb (CCTTT)n microsatellite in the NOS2A gene and a single nucleotide polymorphism (SNP) in -C511T of the IL- IL-1β gene promoter occur in patients after perinatal hypoxic-ischemic encephalopathy. Genomic DNA was purified from peripheral leukocytes of 48 patients with CP and of 57 healthy control children. IL-1β SNP genotypes were established using a real-time PCR technique and fluorogenic probes and were validated by restriction fragment length polymorphism (RFLP) analysis using the AvaI restriction enzyme. The length of the CCTTTn microsatellite in the NOS2 gene promoter was determined by automated sequencing. The 14 repeat-long allele of the CCTTTn NOS2A microsatellite was present in 27% of CP patients vs 12.3% of controls, showing an odds ratio (OR) = 2.6531 and 95% confidence interval (CI) = 0.9612–7.3232 (P < 0.0469). The -511 TT genotype frequency showed an OR = 2.6325 (95% CI = 1.1348–6.1066, P = 0.0189). Interestingly, the haplotype CCTTT14/TT showed an OR = 9.561 (95%, CI = 1.1321–80.753; P = 0.0164). The haplotype (CCTTT)14/TT, formed by the expansion of the − 2.5 kb (CCTTT)n microsatellite in the NOS2A gene promoter and the -511 C➝ T SNP of the IL-1β gene promoter, might be a useful marker to identify patients who are at high risk for developing CP after hypoxic-ischemic encephalopathy.

Analysis of polymorphisms in Interleukin 10, NOS2A, and ESR2 genes in chronic and aggressive periodontitis.

The objective of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in the IL10, NOS2A, and ESR2 genes and chronic periodontitis (CP) and aggressive periodontitis (AgP). Three groups of patients underwent periodontal and radiographic evaluations: CP (n = 61), AgP (n = 50), and periodontally healthy (control group=61). Genomic DNA was extracted from oral epithelial cells and used for genotyping by real-time polymerase chain reaction using TaqMan® probes. The investigated SNPs were: -1087G > A, -819C > T and -592C > A in the IL10; +2087G > A in the NOS2A, and +1730G > A in the ESR2 gene. Differences in genotype and allele frequencies of each polymorphism and some individual characteristics were analyzed using the chi-square test and multivariate logistic regression analysis. Analysis of SNPs and haplotypes in the IL10 and SNP in the ESR2 gene did not present any significant association with AgP or CP. The +2087G allele of the NOS2A gene tended to be significantly associated with periodontal disease. Patients carrying the genotype +2087GG in the NOS2A gene were genetically protected against the development of CP (p = 0.05; OR = 0.44; 95%CI = 0.20-0.95). This result showed greater significance when patients with AgP and CP were combined (total PD) (p = 0.03; OR = 0.46; 95%CI = 0.23-0.92). In conclusion, the studied Brazilian population had a significantly higher frequency of the GG genotype for the +2087 SNP in the NOS2A gene in individuals without periodontitis, although statistical significance was not maintained after multiple logistic regression.

The role of NOS2A -954G/C and vascular endothelial growth factor +936C/T polymorphisms in type 2 diabetes mellitus and diabetic nonproliferative retinopathy risk management.

Type 2 diabetes mellitus (T2DM) remains one of the major health problems in Europe. Retinopathy is one of the major causes of morbidity in T2DM, strongly influencing the evolution and prognosis of these patients. In the last 2 decades, several studies have been conducted to identify the possible genetic susceptibility factors involved in the pathogenesis of the disease. However, there is little data related to the involvement of vascular endothelial growth factor (VEGF) and nitric oxide synthase (NOS) gene polymorphisms in the T2DM Caucasian population. The objective of this study was to identify a possible connection between NOS2A −954G/C (rs2297518) and VEGF +936C/T (rs3025039) polymorphisms and the risk of developing T2DM and nonproliferative diabetic retinopathy in a Caucasian population group. We investigated 200 patients diagnosed with T2DM and 208 controls. Genotypes were determined by multiplex polymerase chain reaction-restriction fragment length polymorphism. Statistical and comparative analyses (Fisher’s exact test) for dominant and recessive models of NOS2A −954G/C and VEGF +936C/T polymorphisms revealed an increased risk of T2DM (χ2=8.14, phi =0.141, P=0.004, odds ratio [OR] =2.795, 95% confidence interval [CI] =1.347–5.801; χ2=18.814, phi =0.215, P<0.001, OR =2.59, 95% CI =1.675–4.006, respectively). Also, comparative analysis for the recessive model (using Pearson’s chi-square test [χ2] and the phi coefficient [phi]) reveals that the variant CC genotype of NOS2A gene is more frequently associated with T2DM without retinopathy (χ2=3.835, phi =−0.138, P=0.05, OR =0.447, 95% CI =0.197–1.015). In conclusion, the results of the study place VEGF +936C/T polymorphisms among the genetic risk factor for T2DM, whereas NOS2A −954G/C polymorphisms act like a protective individual factor for nonproliferative retinopathy.

Association of a Functional Inducible Nitric Oxide Synthase Promoter Variant with Susceptibility to Infantile Cerebral Palsy

Background: Recently it has been shown an increase in the interleukin 1 beta and nitrite levels in cerebrospinal fluid as a primary response of the immature brain to oxygen deprivation in newborns that suffered perinatal asphyxia, 30% to 40% of these patients later develop neurological abnormalities incluiding cerebral palsy. Formerly was shown that an increased enzyme activity of NOS2 is responsible for the increase in nitrite levels in cerebrospinal fluid. The NOS2A gene has a polymorphic microsatellite (CCTTT)n located at -2.6 Kb from the gene promoter. The expansion of this microsatellite to 13 or 14 repeats increases transcription of the NOS2A gene and triples the nitric oxide level under hypoglycemia and hypoxia conditions. The study aim was shown that the expansion of -2.6 Kb CCTTT microsatellite in the NOS2 gene promoter, constitutes a risk factor for developing cerebral palsy in newborns that suffered perinatal asphyxia Methods: Genomic DNAs purified from peripheral leukocytes of 48 ICP patients and 57 healthy children, the (CCTTT)n microsatellite expansion were amplified by PCR, purified from agarosa gel in micro-column method and sequenced using genomelab methods development kit cycle sequencing dye terminator in an automated CEQ8000 sequencer. Results: The presence of a 14-repeat is significantly associated with infant cerebral palsy (Fisher P value=0.0122). Multivariate analysis adjusted for age and sex confirmed the association with an increased risk of developing infant cerebral palsy (odds ratio, 1.78; 95% confidence interval, 1.150-2.752; P=0.01). Conclusions: Our findings suggest that an expansion to 14 repeats of the CCTTT microsatellite plays a key role in the development of cerebral palsy in children that suffered perinatal asphyxia.

NOS2A Gene Polymorphism in Susceptibility to Pulmonary Tuberculosis

Event Abstract Back to Event NOS2A Gene Polymorphism in Susceptibility to Pulmonary Tuberculosis Eloisa Lara Gonzalez1, Fernando A. Hernandez1 and Mercedes T. Fernandez Mestre1* 1 Instituto Venezolano de Investigaciones Cientificas, Centro de Medicina Experimental, Venezuela Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis, which primarily affects the lungs causing pulmonary tuberculosis. In the World Health Organization (WHO) Global Tuberculosis Report for 2014 there were 9.0 million new TB cases in 2013 and 1.5 million TB deaths (1.1 million among HIV-negative and 0.4 million among HIV-positive) of which 218,875 new cases and relapses occurred in the Americas. In Venezuela, according to the WHO, the incidence of new and relapse TB cases is among 20-49 per 100,000 inhabitants. The first interaction between Mycobacterium tuberculosis and the host occurs in pulmonary alveoli, where bacillus is phagocytosed by dendritic cells and macrophages. Nitric oxide (NO) plays a major role in the host-defense mechanism in response to infections and is implicated in bacteriostatic as well as bactericidal processes. NO is produced by three enzyme nitric oxide synthase (NOS) different: NOS1, NOS2 and NOS3. In the promoter region of the gene NOS2 has been identified polymorphisms that affect the binding of transcription factors affecting the concentrations of NO. Since that genetic polymorphism in the promoter of the NOS2 gene could modulate production of NO we investigated in this study the potential association between the NOS2G-954C polymorphism and the development of tuberculosis. Sixty nine patients with pulmonary TB and 94 apparently healthy individuals who have been exposed to Mycobacterium tuberculosis were genotyped for the NOS2G-954C polymorphism by PCR-RFLP. Our results showed not significant association between -954G/C NOS2A variant and susceptibility to either infection or the development of tuberculosis. Furthermore, we found no correlation between different genotypes -954G/C and the concentration of nitrite in plasma. However, we observed in the group of controls with tuberculin skin test positive (TST+) high concentrations of nitrite. In conclusion, the production of nitric oxide would control the Mycobacterium tuberculosis and the presence of other variants of NOS2A gene could determine its concentrations. Acknowledgements The authors are grateful to the persons that participated in this study. This study was supported by CRP - ICGEB Research Grant- CRP/VEN11-01 References Burgner, D. Rockett, K., Kwiatkowski, D. 1999. Nitric oxide and infectious diseases. Dis Childhood 81: 185-188. Kun, J. F., Mordmϋller, B., Perkins, D. J., May, J., Mercereau-Puijalon, O., Alpers, M., Weinberg, J. B., Kremsner, P. G. 2001. Nitric Oxide Synthase 2Lambaréné (G-954C), Increased Nitric Oxide Production, and Protection against Malaria. J. Infect. Dis. 184: 330-336. World Health Organization. Global Tuberculosis Report. 2014. Disponible en: http://www.who.int/tb/publications/global_report/en/ Yang, CH., Yuk, JM. y Jo, EK. 2009. The Role of Nitric Oxide in Mycobacterial Infections. Immun. Netwk. 9: 46-52. Keywords: Polymorphism, Genetic, Tuberculosis, Pulmonary, Nitric Oxide, Nitric Oxide Synthase, TST Conference: IMMUNOCOLOMBIA2015 - 11th Congress of the Latin American Association of Immunology - 10o. Congreso de la Asociación Colombiana de Alergia, Asma e Inmunología, Medellin, Colombia, 13 Oct - 16 Oct, 2015. Presentation Type: Poster Presentation Topic: Immunogenetics Citation: Lara Gonzalez E, Hernandez FA and Fernandez Mestre MT (2015). NOS2A Gene Polymorphism in Susceptibility to Pulmonary Tuberculosis. Front. Immunol. Conference Abstract: IMMUNOCOLOMBIA2015 - 11th Congress of the Latin American Association of Immunology - 10o. Congreso de la Asociación Colombiana de Alergia, Asma e Inmunología. doi: 10.3389/conf.fimmu.2015.05.00110 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 06 Apr 2015; Published Online: 14 Sep 2015. * Correspondence: Dr. Mercedes T Fernandez Mestre, Instituto Venezolano de Investigaciones Cientificas, Centro de Medicina Experimental, Caracas, Distrito Capital, 21827, Caracas 1020A, Venezuela, mfernandezmestre@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Eloisa Lara Gonzalez Fernando A Hernandez Mercedes T Fernandez Mestre Google Eloisa Lara Gonzalez Fernando A Hernandez Mercedes T Fernandez Mestre Google Scholar Eloisa Lara Gonzalez Fernando A Hernandez Mercedes T Fernandez Mestre PubMed Eloisa Lara Gonzalez Fernando A Hernandez Mercedes T Fernandez Mestre Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Association analysis of nitric oxide synthases: NOS1, NOS2A and NOS3 genes, with multiple sclerosis

Background: Multiple sclerosis (MS) is a chronic inflammatory autoimmune disorder of the central nervous system.Aim: To explore the genetic basis of three nitric oxide synthase (NOS) genes: NOS1, NOS2A and NOS3, with susceptibility to MS.Subjects and methods: A total of 122 MS patients and 118 healthy controls screened for NOS1 (rs2682826, rs41279104), NOS2A (CCTTT)n/(TAAA)n and NOS3 (rs1800783, rs1800779, rs2070744, 27bpVNTR) markers, using TaqMan®SNP Genotyping Assays and fragment analysis were enrolled in this study. QRT-PCR and ELISA were used to analyse the expression of NOS3 mRNA and Nitric Oxide (NO) levels.Results: Two NOS3 markers were associated with susceptibility to MS and early disease development. The NOS3 rs1800779 G-allele (p = 0.04) and GG-genotype (p = 0.02) showed association with susceptibility to MS. Short NOS2 (CCTTT)n (p = 0.03) and short/long repeat (p = 0.04) genotypes also showed associations with MS. These associations were intensified by sub-division of patients into Kuwaiti Arabs and Persians (p < 0.05). The NOS3-27 bp-VNTR a-allele was associated with early MS disease onset ≤26 years (p = 0.04). The NOS3-27 bp-VNTR a/b-genotype resulted in 23% lower NO production and the NOS3-rs1800779 AA-genotype resulted in lower NOS3 expression. Haplotypes obtained from NOS2A and NOS3 showed increased susceptibility to MS. NOS1 showed no significant association with MS.Conclusion: This study provides evidence for the association between selected NOS2 and NOS3 markers and MS susceptibility.

RPA-Dependent Melting of Triplex DNA at NOS2a Gene Promoter is Indispensible for p53-Mediated NOS2a Synthesis and Cardioprotection

RPA-Dependent Melting of Triplex DNA at NOS2a Gene Promoter is Indispensible for p53-Mediated NOS2a Synthesis and Cardioprotection

Close association between polymorphisms of the nitric oxide synthetase 3 gene and neurological disorders other than stroke

Correspondence: Shailendra Kapoor 2300 E Cary Street, Richmond, VA 23223, USA Email shailendrakapoor@yahoo.com To the editor I read with great interest the article by Du et al in a recent issue of your journal. The article makes highly interesting reading. Interestingly, the past few years have seen the discovery of a number of close associations between polymorphisms of the nitric oxide synthetase 3 (NOS3) gene and neurological diseases other than stroke. For instance, increased expression of NOS3 results in altered mitochondrial function in neurons. As a consequence, the intracellular levels of reactive oxygen species are accentuated, as are the levels of p53 and Bax, resulting in the dementia and neurodegeneration seen in individuals with Alzheimer’s disease. The G894T polymorphism acts as a risk factor for sporadic frontotemporal lobar degeneration. In fact, in a recent study, Venturelli et al have reported an incidence rate of 40% for the G894T polymorphism in individuals afflicted with frontotemporal lobar degeneration. Similarly, the risk of post-stroke dementia is increased in stroke patients with the rs1799983 polymorphism of the NOS3 gene. For instance, the hazard ratio is 3.14 in stroke patients with the TT genotype in comparison with those having the GG genotype. Similarly, individuals with Pick’s disease and Lewy body disease demonstrate altered NOS3 expression and accelerated proliferation of NOS3-positive neurons. An increased incidence of Parkinson’s disease is also associated with the rs12829185 and rs3782218 polymorphisms of the NOS1 gene and the rs944725 polymorphism of the NOS2A gene. Further, Sohn et al have recently demonstrated increased proliferation of NOS3-expressing glial cells in amyotrophic lateral sclerosis, as well as in progressive supranuclear palsy. The above examples illustrate a clear association between NOS3 and many neurological diseases, ranging from Alzheimer’s disease to Pick’s disease. Modulation of NOS3 function may alter and beneficially attenuate the progression of these diseases. Hopefully, the coming years will see the development of these NOS3 modulators.

Single nucleotide polymorphisms in NOS2A and NOS3 genes are not associated with treatment response of non-small cell lung cancer patients following the definitive radiochemotherapy

Nitric oxide (NO), is endogenously synthesized from L-arginine by nitric oxide synthase (NOS), exhibits a dual role in sensitivity to radiotherapy and chemotherapy of cancer cells. The aim of this study was to evaluate the influence of polymorphisms in NOS genes on treatment response of non-small-cell lung cancer (NSCLC) patients after radiochemotherapy. A cohort of 198 NSCLC patients treated with radiochemotherapy between 2009 and 2011 were included in this study. Genotyping analyses of 35 SNPs ( NOS2A, 21 and NOS3, 14) in each sample were conducted by using the Sequenom MassArray system. Unconditional logistic regression was performed to assess the association between treatment response and each genotype while adjusting or not for other covariates. Of 198 patients, 87 (43.9%) had objective responses, and 111(56.1%) did not respond. We observed no significant associations between treatment response and each genotype. While adjusting for other covariates, the associations were also not significant. Our results suggest that genetic variations within the NOS2A and NOS3 genes may not influence the treatment response in NSCLC patients with radiochemotherapy. Future studies in this problem are required to confirm our findings.

Functional Variants inNOS1andNOS2AAre Not Associated with Progressive Hearing Loss in Ménière's Disease in a European Caucasian Population

Hearing loss in Ménière's disease (MD) is associated with loss of spiral ganglion neurons and hair cells. In a guinea pig model of endolymphatic hydrops, nitric oxide synthases (NOS) and oxidative stress mediate loss of spiral ganglion neurons. To test the hypothesis that functional variants of NOS1 and NOS2A are associated with MD, we genotyped three functional variants of NOS1 (rs41279104, rs2682826, and a cytosine-adenosine microsatellite repeat in exon 1f) and the CCTTT repeat in the promoter of NOS2A gene (rs3833912) in two independent MD sets (273 patients in total) and 550 controls. A third cohort of American patients was genotyped as replication cohort for the CCTTT repeat. Neither allele nor genotype frequencies of rs41279104 and rs2682826 were associated with MD, although longer alleles of the cytosine-adenosine microsatellite repeat were marginally significant (corrected p = 0.05) in the Mediterranean cohort but not in a second Galicia cohort. Shorter numbers of the CCTTT repeat in NOS2A were significantly more frequent in Galicia controls (OR = 0.37 [CI, 0.18-0.76], corrected p = 0.04), but this finding could not be replicated in Mediterranean or American case-control populations. Meta-analysis did not support an association between CCTTT repeats and risk for MD. Severe hearing loss (>75 dB) was also not associated with any functional variants studied. Functional variants of NOS1 and NOS2A do not confer susceptibility for MD.

DNA Methylation in the Arginase–Nitric Oxide Synthase Pathway Is Associated with Exhaled Nitric Oxide in Children with Asthma

Genetic variation in arginase (ARG) and nitric oxide synthase (NOS) has been associated with exhaled nitric oxide (FeNO) levels in children. Little is known about whether epigenetic variation in these genes modulates FeNO. To evaluate whether DNA methylation in ARG and NOS genes is associated with FeNO. A subset of 940 participants in the Children's Health Study were selected for this study. Children were eligible if they had FeNO measurements and buccal cells collected on the same day. CpG loci located in the promoter regions of NOS1, NOS2A, NOS3, ARG1, and ARG2 genes were analyzed. Multiple loci in each gene were evaluated individually and averaged together. DNA methylation was measured using a bisulfite-polymerase chain reaction pyrosequencing assay. Linear regression models were used to investigate the association between DNA methylation and FeNO and whether associations differed by asthma status. DNA methylation in ARG2 was significantly associated with FeNO. A 1% increase in average DNA methylation of ARG2 was associated with a 2.3% decrease in FeNO (95% confidence interval, -4 to -0.6). This association was significantly larger in children with asthma (%diff = -8.7%) than in children with no asthma (%diff = -1.6%; p(int) = 0.01). Differences in FeNO by asthma status were also observed for ARG1 (%diff(asthma) = -4.4%; %diff(non-asthma) = 0.3%; p(int) = 0.02). DNA methylation in NOS genes was not associated with FeNO. DNA methylation in ARG1 and ARG2 is associated with FeNO in children with asthma and suggests a possible role for epigenetic regulation of nitric oxide production.

NOS2A as a candidate gene in Relapsing–Remitting Multiple Sclerosis: A haplotype study using selected subsets of single nucleotide polymorphisms

As with other autoimmune diseases, susceptibility to multiple sclerosis (MS) is believed to result from the complex interaction of a number of genes, each with modest effect. Several genome-wide screens have implicated the nitric oxide synthase 2A gene (NOS2A), which encodes the inducible form of nitric oxide synthase, as being potentially associated with MS. To determine whether genetic variants within this gene may constitute a risk factor for causing MS, we investigated 13 single nucleotide polymorphisms in the NOS2A gene, in a case–control group of 214 Italian patients with MS and 121 controls. All these single nucleotide polymorphisms (SNPs) were analyzed using the SNPlex™ Genotyping System (Applied Biosystems). Data were analyzed using Genemapper 4.0 and Haploview 4.1. No significant association between cases and controls (P > 0.05) was observed for the alleles of the SNPs. Defining the haplotype blocks also failed to detect any associated haplotypes. Our results suggest that polymorphic variation within the NOS2A gene does not influence the susceptibility to MS in patients of Italian origin.

Association between inducible and neuronal nitric oxide synthase polymorphisms and recurrent depressive disorder

Background Major depression is characterised by increased nitric oxide (NO) levels. Inhibition of the NO synthesizing enzymes, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS), results in antidepressant-like effects, whereas the expression of iNOS and nNOS is increased in depression. Recent studies have indicated that NOS participates in the mechanisms of antidepressants. The aim of this study was to examine whether a single nucleotide polymorphism (SNP) present in the genes encoding iNOS and nNOS can contribute to the risk of developing recurrent depressive disorder (rDD). Methods The study was carried out in a group of 181 depressive patients and 149 control subjects of Polish origin. SNPs were assessed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses. Results The genotype distributions of the polymorphisms in exon 22 of the NOS2A gene and in exon 29 of the nNOS gene were significantly different between rDD patients and controls. The results showed that the G/A SNP of the gene encoding iNOS was associated with an increased susceptibility to rDD, whereas A/A homozygous carriers had a decreased risk of developing rDD. There was also a significant association between the C/T SNP of the gene encoding nNOS; the presence of the CC homozygous genotype decreased the risk of rDD, whereas the T allele and T/T homozygous genotype increased the vulnerability to rDD. Conclusions Our results suggest that polymorphisms in the iNOS and nNOS genes confer an increased susceptibility or resistance to rDD. Future research should examine genetic variants and their associations to the expression of NOSs and NO level in depressive patients.

An inducible nitric oxide synthase polymorphism is associated with the risk of recurrent depressive disorder

Evidence indicates that depressive disorder is a heterogenic disease, and oxidative stress, inflammation and impairment of neurogenesis play a role in its aetiology. Moreover, there are data suggesting that genetic factors affect the development of depression. Nitric oxide (NO) is a biological molecule with both a beneficial and a detrimental role in brain. One of the three enzymes generating NO is inducible nitric oxide synthase (iNOS). Recent studies have shown that depressed patients are characterised by excessive NO production. In addition, iNOS inhibitors are effective in depression treatment. This study investigated the importance of a functional single nucleotide polymorphism (SNP), −1026C/A, located in the promoter region of the human NOS2A gene, for the risk of recurrent depressive disorder (RDD) vulnerability. The study was carried out in a group of 181 patients with RDD and 149 ethnically matched controls. Genotyping was performed by direct sequencing of the polymerase chain reaction (PCR) products. The genotype distribution of the −1026C/A polymorphism between depressed patients and healthy controls was significantly different. Individuals who were homozygous for the CC genotype exhibited an increased risk of developing RDD. In conclusion we cautiously conclude that polymorphism in the NOS2A gene promoter may play a role in the background of RDD.