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Sample records for methylenetetrahydrofolate reductase polymorphisms

  1. Prognostic Relevance of Methylenetetrahydrofolate Reductase Polymorphisms for Prostate Cancer

    PubMed Central

    Lin, Victor C.; Lu, Te-Ling; Yin, Hsin-Ling; Yang, Sheau-Fang; Lee, Yung-Chin; Liu, Chia-Chu; Huang, Chao-Yuan; Yu, Chia-Cheng; Chang, Ta-Yuan; Huang, Shu-Pin; Bao, Bo-Ying

    2016-01-01

    Folate metabolism has been associated with cancers via alterations in nucleotide synthesis, DNA methylation, and DNA repair. We hypothesized that genetic variants in methylenetetrahydrofolate reductase (MTHFR), a key enzyme of folate metabolism, would affect the prognosis of prostate cancer. Three haplotype-tagging single-nucleotide polymorphisms (SNPs) across the MTHFR gene region were genotyped in a cohort of 458 patients with clinically localized prostate cancer treated with radical prostatectomy. One SNP, rs9651118, was associated with disease recurrence, and the association persisted after multivariate analyses adjusting for known risk factors. Public dataset analyses suggested that rs9651118 affects MTHFR expression. Quantitative real-time polymerase chain reaction analysis revealed that MTHFR expression is significantly upregulated in prostate tumor tissues when compared with adjacent normal tissues. Furthermore, overexpression of MTHFR correlates with cancer recurrence and death in two independent publicly available prostate cancer datasets. In conclusion, our data provide rationale to further validate the clinical utility of MTHFR rs9651118 as a biomarker for prognosis in prostate cancer. PMID:27916838

  2. The polymorphisms in methylenetetrahydrofolate reductase, methionine synthase, methionine synthase reductase, and the risk of colorectal cancer.

    PubMed

    Zhou, Daijun; Mei, Qiang; Luo, Han; Tang, Bo; Yu, Peiwu

    2012-01-01

    Polymorphisms in genes involved in folate metabolism may modulate the risk of colorectal cancer (CRC), but data from published studies are conflicting. The current meta-analysis was performed to address a more accurate estimation. A total of 41 (17,552 cases and 26,238 controls), 24(8,263 cases and 12,033 controls), 12(3,758 cases and 5,646 controls), and 13 (5,511 cases and 7,265 controls) studies were finally included for the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1289C, methione synthase reductase (MTRR) A66G, methionine synthase (MTR) A2756G polymorphisms and the risk of CRC, respectively. The data showed that the MTHFR 677T allele was significantly associated with reduced risk of CRC (OR = 0.93, 95%CI 0.90-0.96), while the MTRR 66G allele was significantly associated with increased risk of CRC (OR = 1.11, 95%CI 1.01-1.18). Sub-group analysis by ethnicity revealed that MTHFR C677T polymorphism was significantly associated with reduced risk of CRC in Asians (OR = 0.80, 95%CI 0.72-0.89) and Caucasians (OR = 0.84, 95%CI 0.76-0.93) in recessive genetic model, while the MTRR 66GG genotype was found to significantly increase the risk of CRC in Caucasians (GG vs. AA: OR = 1.18, 95%CI 1.03-1.36). No significant association was found between MTHFR A1298C and MTR A2756G polymorphisms and the risk of CRC. Cumulative meta-analysis showed no particular time trend existed in the summary estimate. Probability of publication bias was low across all comparisons illustrated by the funnel plots and Egger's test. Collectively, this meta-analysis suggested that MTHFR 677T allele might provide protection against CRC in worldwide populations, while MTRR 66G allele might increase the risk of CRC in Caucasians. Since potential confounders could not be ruled out completely, further studies were needed to confirm these results.

  3. The Polymorphisms in Methylenetetrahydrofolate Reductase, Methionine Synthase, Methionine Synthase Reductase, and the Risk of Colorectal Cancer

    PubMed Central

    Zhou, Daijun; Mei, Qiang; Luo, Han; Tang, Bo; Yu, Peiwu

    2012-01-01

    Polymorphisms in genes involved in folate metabolism may modulate the risk of colorectal cancer (CRC), but data from published studies are conflicting. The current meta-analysis was performed to address a more accurate estimation. A total of 41 (17,552 cases and 26,238 controls), 24(8,263 cases and 12,033 controls), 12(3,758 cases and 5,646 controls), and 13 (5,511 cases and 7,265 controls) studies were finally included for the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1289C, methione synthase reductase (MTRR) A66G, methionine synthase (MTR) A2756G polymorphisms and the risk of CRC, respectively. The data showed that the MTHFR 677T allele was significantly associated with reduced risk of CRC (OR = 0.93, 95%CI 0.90-0.96), while the MTRR 66G allele was significantly associated with increased risk of CRC (OR = 1.11, 95%CI 1.01-1.18). Sub-group analysis by ethnicity revealed that MTHFR C677T polymorphism was significantly associated with reduced risk of CRC in Asians (OR = 0.80, 95%CI 0.72-0.89) and Caucasians (OR = 0.84, 95%CI 0.76-0.93) in recessive genetic model, while the MTRR 66GG genotype was found to significantly increase the risk of CRC in Caucasians (GG vs. AA: OR = 1.18, 95%CI 1.03-1.36). No significant association was found between MTHFR A1298C and MTR A2756G polymorphisms and the risk of CRC. Cumulative meta-analysis showed no particular time trend existed in the summary estimate. Probability of publication bias was low across all comparisons illustrated by the funnel plots and Egger's test. Collectively, this meta-analysis suggested that MTHFR 677T allele might provide protection against CRC in worldwide populations, while MTRR 66G allele might increase the risk of CRC in Caucasians. Since potential confounders could not be ruled out completely, further studies were needed to confirm these results. PMID:22719222

  4. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism: epidemiology, metabolism and the associated diseases.

    PubMed

    Liew, Siaw-Cheok; Gupta, Esha Das

    2015-01-01

    The Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is associated with various diseases (vascular, cancers, neurology, diabetes, psoriasis, etc) with the epidemiology of the polymorphism of the C677T that varies dependent on the geography and ethnicity. The 5,10-Methylenetetrahydrofolate reductase (MTHFR) locus is mapped on chromosome 1 at the end of the short arm (1p36.6). This enzyme is important for the folate metabolism which is an integral process for cell metabolism in the DNA, RNA and protein methylation. The mutation of the MTHFR gene which causes the C677T polymorphism is located at exon 4 which results in the conversion of valine to alanine at codon 222, a common polymorphism that reduces the activity of this enzyme. The homozygous mutated subjects have higher homocysteine levels while the heterozygous mutated subjects have mildly raised homocysteine levels compared with the normal, non-mutated controls. Hyperhomocysteinemia is an emerging risk factor for various cardiovascular diseases and with the increasing significance of this polymorphism in view of the morbidity and mortality impact on the patients, further prevention strategies and nutritional recommendations with the supplementation of vitamin B12 and folic acid which reduces plasma homocysteine level would be necessary as part of future health education. This literature review therefore focuses on the recent evidence-based reports on the associations of the MTHFR C677T polymorphism and the various diseases globally.

  5. The Importance of Homozygous Polymorphisms of Methylenetetrahydrofolate Reductase Gene in Romanian Patients with Idiopathic Venous Thromboembolism

    PubMed Central

    Hotoleanu, Cristina; Trifa, Adrian; Popp, Radu; Fodor, Daniela

    2013-01-01

    Background: Methylenetetrahydrofolate reductase (MTHFR) polymorphisms have recently raised the interest as a possible thrombophilic factors. Aims: We aimed to assess the frequency of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms in idiopathic venous thromboembolism (VTE) in a Romanian population and the associated risk of VTE. Study Design: We performed a case-control transversal study including 90 patients diagnosed with VTE and 75 sex- and age-matched controls. Methods: MTHFR C677T and A1298C polymorphisms were detected using PCR-RFLP method. Results: The homozygous MTHFR 677TT genotype, present in 18.8% of patients with VTE versus 6.6% of controls, was significantly associated with VTE (p= 0.021, OR= 3.26, 95%CI (1.141–9.313)). The heterozygous MTHFR A1298C genotype, presenting the highest prevalence in the VTE group (34.4%) as well as in controls (37.3%), was not associated with VTE (p=0.7). No associations were found for heterozygous MTHFR C677T (with a frequency of 32.2% in VTE and 37.3% in controls, p=0.492), respective homozygous MTHFR A1298C genotype (with a frequency of 1.1% in VTE and 2.6% in controls, p=0.456). Conclusion: Among MTHFR polymorphisms, only homozygosity for MTHFR 677TT may be considered a risk factor for VTE; the MTHFR A1298C polymorphism is not significantly associated with an increased risk of VTE. PMID:25207100

  6. Role of methylenetetrahydrofolate reductase gene (MTHFR) 677C>T polymorphism in pediatric cerebrovascular disorders.

    PubMed

    Alsayouf, Hamza; Zamel, Khaled M; Heyer, Geoffrey L; Khuhro, A Latif; Kahwash, Samir B; de los Reyes, Emily C

    2011-03-01

    Homozygosity for the methylenetetrahydrofolate reductase (MTHFR) 677C>T mutation (MTHFR TT) has been linked to an increased risk for stroke, coronary artery disease, and migraine headaches. The authors analyzed the potential link between MTHFR 677C>T homozygosity and childhood stroke. A true association might facilitate screening, recurrence risk stratification, and treatment in patients with cerebrovascular disease. They performed a retrospective chart review of children tested for the MTHFR 677C>/T mutation; 533 patients underwent MTHFR testing, and 8% were homozygous for the MTHFR 677C>T mutation. There was no difference in the cohort compared with the prevalence in the general population. This suggests that the MTHFR 677 C>T polymorphism played a minimal role or no role in stroke risk. However, the data suggest that the MTHFR TT genotype may influence migraine susceptibility in children because there was a higher proportion of migraine patients (28.6%) with the MTHFR TT homozygous genotype.

  7. Association between methylenetetrahydrofolate reductase C677T polymorphism and psoriasis: A meta-analysis.

    PubMed

    Wu, Dongze; Shi, Deshun; Yang, Li; Zhu, Xiaoliang

    2016-02-01

    Several studies have evaluated the associations between methylenetetrahydrofolate reductase (MTHFR) C677T and psoriasis. However, the results remain inconclusive. The objective of the present study was to conduct a qualitative and quantitative meta-analysis investigating the associations between MTHFR C677T and psoriasis. A published work search of PubMed, Embase, Web of Science and Chinese National Knowledge Infrastructure database were conducted to identify all publications concerning MTHFR C677T polymorphism and psoriasis on 1 October 2014. The principal outcome measure for evaluating the strength of the association was crude odds ratios along with their corresponding 95% confidence intervals. Data were extracted and statistical analyses were implemented using STATA version 12.0 software. A total of 1179 psoriatic cases and 937 controls from five case-control studies concentrating on the association between MTHFR C677T polymorphism and psoriasis were included in this qualitative meta-analysis. Pooled analysis revealed that there is no association between this polymorphism and susceptibility to psoriasis in dominant, recessive, allele and additive models under a random-effect model. However, a marginal significant association was found in the overdominant model under fixed-effect model. Subgroup analysis of ethnicity demonstrated that there is no association between MTHFR C677T polymorphism and either Asian or European psoriatic patients. In conclusion, MTHFR C677T polymorphism, qualitatively, is not a genetic factor for the pathogenesis of psoriasis but could quantitatively reflect the severity of psoriasis to some extent.

  8. 5,10-Methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTRR), and methionine synthase reductase (MTR) gene polymorphisms and adult meningioma risk.

    PubMed

    Zhang, Jun; Zhou, Yan-Wen; Shi, Hua-Ping; Wang, Yan-Zhong; Li, Gui-Ling; Yu, Hai-Tao; Xie, Xin-You

    2013-11-01

    The causes of meningiomas are not well understood. Folate metabolism gene polymorphisms have been shown to be associated with various human cancers. It is still controversial and ambiguous between the functional polymorphisms of folate metabolism genes 5,10-methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTRR), and methionine synthase reductase (MTR) and risk of adult meningioma. A population-based case–control study involving 600 meningioma patients (World Health Organization [WHO] Grade I, 391 cases; WHO Grade II, 167 cases; WHO Grade III, 42 cases) and 600 controls was done for the MTHFR C677T and A1298C, MTRR A66G, and MTR A2756G variants in Chinese Han population. The folate metabolism gene polymorphisms were determined by using a polymerase chain reaction–restriction fragment length polymorphism assay. Meningioma cases had a significantly lower frequency of MTHFR 677 TT genotype [odds ratio (OR) = 0.49, 95 % confidence interval (CI) 0.33–0.74; P = 0.001] and T allele (OR = 0.80, 95 % CI 0.67–0.95; P = 0.01) than controls. A significant association between risk of meningioma and MTRR 66 GG (OR = 1.41, 95 % CI 1.02–1.96; P = 0.04) was also observed. When stratifying by the WHO grade of meningioma, no association was found. Our study suggested that MTHFR C677T and MTRR A66G variants may affect the risk of adult meningioma in Chinese Han population.

  9. Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and susceptibility to ischemic stroke: a meta-analysis.

    PubMed

    Li, Pingping; Qin, Chao

    2014-02-10

    Associations between 5,10-methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and ischemic stroke have been reported (Ariyaratnam et al., 2007; Banerjee et al., 2007; Casas et al., 2004), but the results of these studies are inconsistent. To investigate the possible associations between the MTHFR gene polymorphism and ischemic stroke, we performed a meta-analysis. Nineteen case-control studies associated with MTHFR gene C667T involving 2223 cases and 2936 controls were included. Heterogeneity among studies was evaluated with I(2) and Egger's test and an inverted funnel plot was used to assess publication bias. Odds ratio (OR) was observed to identify the associations. Statistically significant association with ischemic stroke was identified for allele T polymorphism of MTHFR [fixed-effects OR=1.28, 95% confidence interval (95% CI): 1.17-1.40, P<0.00001] and marginally significant association was detected with genotype CT of MTHFR (fixed-effects OR=1.13, 95% CI: 1.01-127, P=0.04) and genotype TT of MTHFR (fixed-effects OR=1.43, 95% CI: 1.20-1.70, P<0.001). The results suggested that the MTHFR C667T genetic polymorphism was significantly associated with increased risk of ischemic stroke.

  10. Folate Pathway Gene Methylenetetrahydrofolate Reductase C677T Polymorphism and Alzheimer Disease Risk in Asian Population.

    PubMed

    Rai, Vandana

    2016-07-01

    The association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and susceptibility to Alzheimers disease (AD) was controversial in previous studies. The present meta-analysis was designed to investigate the association of MTHFR C677T polymorphism with AD. Nine studies were identified by search of PubMed, Google Scholar, Elsevier, Springer Link databases, up to January 2013. Odds ratios (ORs) with corresponding 95 % confidence interval (CI) were calculated using fixed effects model or random effects model. All statistical analysis was done by Mix version 1.7. MTHFR C677T polymorphism had a significant association with susceptibility to AD in all genetic models (for T vs C: OR 1.29, 95 % CI 1.15-1.44, p < 0.0001; for TT + CT vs CC: OR 1.38, 95 % CI 1.16-1.364, p = 0.0002; for TT vs CC: OR 1.60, 95 % CI 1.25-2.04, p = 0.0001; for CT vs CC: OR 1.28, 95 % CI 1.1-1.53, p < 0.008; for TT vs CT + CC: OR 1.37, 95 % CI 1.12-1.67, p = 0.002). Results from present meta-analysis supported that the MTHFR C677T polymorphism was associated with an increased risk of AD in Asian population.

  11. Polymorphisms of methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), methionine synthase reductase (MTRR), and thymidylate synthase (TYMS) in multiple myeloma risk.

    PubMed

    Lima, Carmen S P; Ortega, Manoela M; Ozelo, Margareth C; Araujo, Renato C; De Souza, Cármino A; Lorand-Metze, Irene; Annichino-Bizzacchi, Joyce M; Costa, Fernando F

    2008-03-01

    We tested whether the polymorphisms of the methylenetetrahydrofolate reductase gene, MTHFR C677T and A1298C, the methionine synthase gene, MTR A2756G, the methionine synthase reductase gene, MTRR A66G, and the thymidylate synthase gene, TYMS 2R-->3R, involved in folate and methionine metabolism, altered the risk for multiple myeloma (MM). Genomic DNA from 123MM patients and 188 controls was analysed by polymerase chain reaction and restriction digestion for the polymorphism analyses. The frequency of the MTR 2756 AG plus GG genotype was higher in patients than in controls (39.8% versus 23.4%, P=0.001). Individual carriers of the variant allele G had a 2.31 (95% CI: 1.38-3.87)-fold increased risk for MM compared with others. In contrast, similar frequencies of the MTHFR, the MTRR and the TYMS genotypes were seen in patients and controls. These results suggest, for the first time, a role for the MTR A2756G polymorphism in MM risk in our country, but should be confirmed by large-scale epidemiological studies with patients and controls age matched.

  12. Meta-analysis of methylenetetrahydrofolate reductase (MTHFR) polymorphisms affecting methotrexate toxicity

    PubMed Central

    Fisher, Mark C.; Cronstein, Bruce N.

    2008-01-01

    Objective Methotrexate is an effective therapy for Rheumatoid Arthritis (RA) but is also associated with toxicity. Pharmacogenetics is the systematic evaluation of the role of genetic differences in the efficacy and toxicity of therapeutic interventions. Because the results of small pharmacogenetic studies are often misleading, we undertook a meta-analysis of published studies to determine the role of polymorphisms in the therapeutic efficacy and toxicity of methotrexate. Methods A search of PUBMED produced 55 publications which were then reviewed for relevance to methotrexate toxicity and efficacy in patients with RA. To ensure that no studies were missed, each polymorphism found was then entered as an independent search string and all results were again reviewed. Results Only 2 polymorphisms (C677T and A1298C in methylenetetrahydrofolate reductase, MTHFR, total: 8 studies) relevant to methotrexate metabolism and efficacy had sufficient data to perform a meta-analysis of their association with toxicity; there was no polymorphism with sufficient data to perform a meta-analysis of efficacy. In a fixed effects model, the C677T polymorphism was associated with increased toxicity (OR 1.71, CI 1.32 – 2.21, p<0.001). The A1298C polymorphism was not associated with increased toxicity (OR 1.12, CI 0.79 – 1.6, p=0.626). Conclusions As pharmacogenetics evolves, more data are needed to assess the role of various polymorphisms for drug efficacy and toxicity. These results illustrate the paucity of reliable pharmacogenetic data on a commonly used anti-rheumatic drug and the potential role of pharmacogenetics in tailoring drug therapy for an individual patient. PMID:19208607

  13. The effect of methylenetetrahydrofolate reductase polymorphisms on susceptibility to human papilloma virus infection and cervical cancer.

    PubMed

    Hajiesmaeil, Mogge; Tafvizi, Farzaneh; Sarmadi, Soheila

    2016-12-01

    Cervical cancer is the third most common cancer among women worldwide. Several factors lead to cervical cancer, among which human papilloma virus (HPV) infection has a prominent role. Methylenetetrahydrofolate reductase (MTHFR) is crucial in folate metabolic pathway and plays an important role in DNA synthesis and DNA methylation. MTHFR gene polymorphisms, including C677T and A1298C, lead to reduced enzyme activity. This case-control study aims to illustrate the association between MTHFR gene polymorphisms and the risk of cervical cancer. This study was conducted on 196 samples, which included 96 cervical biopsy samples compared to 100 Pap smear samples of normal healthy women without HPV infection. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used for the MTHFR polymorphism detection, followed by fluorescent amplification-based specific hybridization PCR method to detect HPV16 and HPV18. The results show that the MTHFR 677TT genotype plays a protective role in cervical cancer (P=0.0030) (OR=0.21, 95% confidence interval [CI]: 0.07-0.59). Furthermore, there was a strong significant association between MTHFR 1298CC genotype and the risk of cervical cancer (OR=10.69; 95% CI: 4.28-26.71, P=0.0001). It can be concluded that A1298C polymorphism is a genetic risk factor for cervical cancer in the assessed Iranian population group. It seems that MTHFR 1298CC genotype is more susceptible to HPV 16 infection. Combination analysis of MTHFR C677T and A1298C polymorphisms revealed that combined MTHFR 677CC and 1298CC are strongly associated with a risk of cervical cancer.

  14. Methylenetetrahydrofolate reductase (MTHFR) polymorphism susceptibility to schizophrenia and bipolar disorder: an updated meta-analysis.

    PubMed

    Hu, Cai-Yun; Qian, Zhen-Zhong; Gong, Feng-Feng; Lu, Shan-Shan; Feng, Fang; Wu, Yi-Le; Yang, Hui-Yun; Sun, Ye-Huan

    2015-02-01

    Previous studies examining the possible role of the methylenetetrahydrofolate reductase (MTHFR) polymorphisms in the development of schizophrenia (SZ) and bipolar disorder (BPD) have provided inconclusive findings, this meta-analysis was therefore designed to get a more reliable assessment. A total of 38 articles were identified through a search of electronic databases, up to 27 February 2014. Odds ratios (ORs) with 95% confidence interval (CIs) were calculated using random effects models. Meta-analysis showed that MTHFR C677T was significantly associated with SZ, the highest OR was found for the recessive model (for TT vs. CT + CC: OR = 1.34, 95% CI: 1.18-1.53); a marginal association of MTHFR C677T with increased risk of BPD has also been found for the recessive model (OR = 1.26, 95% CI: 1.00-1.59). Subgroup analysis by ethnicity indicated that the significant association with SZ and BPD existed among Asian and African populations, but not for the white. MTHFR A1298C was significant associated with SZ, the highest OR for the dominant model (OR = 1.13, 95% CI: 1.03-1.24). Subgroup analysis indicated a significant association with SZ existed in Asian populations, not among the white populations and no significant association was detected between the MTHFR A1298C and BPD in all groups. We conclude that MTHFR polymorphism is associated with SZ and BPD among Asian, African populations, but not the white.

  15. Is methylenetetrahydrofolate reductase (MTHFR) gene A1298C polymorphism related with varicocele risk?

    PubMed

    Ucar, V B; Nami, B; Acar, H; Kilinç, M

    2015-02-01

    Varicocele is one of the main reasons for male infertility the exact aetiology of which remains unclear. Methylenetetrahydrofolate reductase (MTHFR) is important for DNA synthesis and methylation, which has a key role during spermatogenesis. Numerous literature suggests that the MTHFR polymorphism may be genetic risk factors for male infertility. In this study, we evaluated C677T and A1298C MTHFR gene polymorphism frequency in patients with varicocele and normal men. A total of 107 varicocele patients and 109 fertile healthy individuals were included. Genotyping of the MTHFR gene in C677T and A1298C base pairs carried out by using real-time PCR technique and afterwards, the statistical analysis accomplished. There is a statistical difference for the frequency of 1298AA genotype in patients with varicocele compared with normal controls (P = 0.0051, OR = 2.2750). Instead, subsequently, 1298/A allel frequency in patient group was significantly higher in comparison with control group (P = 0.0174). According to our results, 1298AA genotype in MTHFR gene raises the risk of varicocele approximately 2.3 times more compared with men carrying other genotypes. The results show that genetic factors have an important role in the molecular basis of varicocele.

  16. Methylenetetrahydrofolate reductase (MTHFR) polymorphisms and promoter methylation in cervical oncogenic lesions and cancer.

    PubMed

    Botezatu, Anca; Socolov, Demetra; Iancu, Iulia V; Huica, Irina; Plesa, Adriana; Ungureanu, Carmen; Anton, Gabriela

    2013-04-01

    The aim of this study was to investigate the role of methylenetetrahydrofolate reductase (MTHFR) polymorphisms and MTHFR methylation pattern in cervical lesions development among women from Romania, a country with high prevalence of human papillomavirus (HPV) cervical infections. To achieve this goal, blood samples and cervical cytology specimens (n = 77)/tumour tissue specimens (n = 23) were investigated. As control, blood and negative cytological smears (n = 50) were used. A statistically significant association was found between T allele of C677T polymorphism and cervical lesions, heterozygote women presenting a threefold increased risk (normal/cervical lesions and tumours: wild homozygote 34/41 (0.68/0.41), heterozygote 14/51 (0.28/0.51), mutant homozygote 2/8 (0.04/0.08); OR = 3.081, P = 0.0035). Using χ square test for the control group, the HPV-negative and HPV-positive patients with cervix lesions, a significant correlation between viral infection and T allele of C677T polymorphism (P = 0.0287) was found. The MTHFR promoter was methylated in all HGSIL and tumour samples, significant differences being noted between HPV-positive samples, control group and cases of cervical dysplastic lesions without HPV DNA (P < 0. 0001) and between samples from patients with high-risk (hr)HPV versus low-risk (lr)HPV (P = 0.0026). No correlations between polymorphisms and methylation were observed. In Romania, individuals carrying T allele are susceptible for cervical lesions. MTHFR promoter methylation is associated with cervical severity lesions and with hrHPV.

  17. Methylenetetrahydrofolate Reductase (MTHFR) C677T Polymorphism and Alzheimer Disease Risk: a Meta-Analysis.

    PubMed

    Rai, Vandana

    2017-03-01

    Methylenetetrahydrofolate reductase (MTHFR) is key enzyme of folate/homocysteine pathway. Case control association studies on MTHFR C677T polymorphism and Alzheimer's disease (AD) have been repeatedly performed over the last two decades, but the results are inconclusive. The aim of the present study was to assess the risk of MTHFR C677T polymorphism for AD. Forty-one studies were identified by a search of PubMed, Google Scholar, Elsevier, and Springer Link databases, up to January 2015. Odds ratios (ORs) with corresponding 95 % confidence interval (CI) were calculated using fixed effect model or random effect model. The subgroup analyses based on ethnicity were performed. MTHFR C677T polymorphism had a significant association with susceptibility to AD in all genetic models (for T vs C OR = 1.29, 95 % CI = 1.07-1.56, p = 0.003; for TT + CT vs CC OR = 1.29, 95 % CI = 1.19-1.40, p = 0.0004; for TT vs CC OR = 1.31, 95 % CI = 1.16-1.48, p = 0.001; for CT vs CC OR = 1.24, 95 % CI = 1.13-1.35, p < 0.004; and for TT vs CT + CC OR = 1.13, 95 % CI = 1.00-1.28, p = 0.02). Results of present meta-analysis supported that the MTHFR C677T polymorphism was associated with an increased risk of AD.

  18. Effects of methionine synthase and methylenetetrahydrofolate reductase gene polymorphisms on markers of one-carbon metabolism.

    PubMed

    Ho, Vikki; Massey, Thomas E; King, Will D

    2013-11-01

    Genetic and nutritional factors play a role in determining the functionality of the one-carbon (1C) metabolism cycle, a network of biochemical reactions critical to intracellular processes. Genes encoding enzymes for methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MTR) may determine biomarkers of the cycle including homocysteine (HCY), S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH). MTHFR C677T is an established genetic determinant of HCY but less is known of its effect on SAM and SAH. Conversely, the relationship between MTR A2756G and HCY remains inconclusive, and its effect on SAM and SAH has only been previously investigated in a female-specific population. Folate and vitamin B12 are essential substrate and cofactor of 1C metabolism; thus, consideration of gene-nutrient interactions may clarify the role of genetic determinants of HCY, SAM and SAH. This cross-sectional study included 570 healthy volunteers from Kingston, Ontario, Ottawa, Ontario and Halifax, Nova Scotia, Canada. Least squares regression was used to examine the effects of MTR and MTHFR polymorphisms on plasma HCY, SAM and SAH concentrations; gene-gene and gene-nutrient interactions were considered with the inclusion of cross-products in the model. Main effects of MTR and MTHFR polymorphisms on HCY concentrations were observed; however, no gene-gene or gene-nutrient interactions were found. No association was observed for SAM. For SAH, interactions between MTR and MTHFR polymorphisms, and MTHFR polymorphism and serum folate were found. The findings of this research provide evidence that HCY and SAH, biomarkers of 1C metabolism, are influenced by genetic and nutritional factors and their interactions.

  19. 5,10 Methylenetetrahydrofolate reductase genetic polymorphism as a risk factor for neural tube defects

    SciTech Connect

    Ou, C.Y.; Brown, V.K.; Khoury, M.J.

    1996-06-28

    Persons with a thermolabile form of the enzyme 5,10 methylenetetrahydrofolate reductase (MTHFR) have reduced enzyme activity and increased plasma homocysteine which can be lowered by supplemental folic acid. Thermolability of the enzyme has recently been shown to be caused by a common mutation (677C{sup {r_arrow}}T) in the MTHFR gene. We studied 41 fibroblast cultures from NTD-affected fetuses and compared their genotypes with those of 109 blood specimens from individuals in the general population. 677C{sup {r_arrow}}T homozygosity was associated with a 7.2 fold increased risk for NTDs (95% confidence interval: 1.8-30.3; p value: 0.001). These preliminary data suggest that the 677C{sup {r_arrow}}T polymorphism of the MTHFR gene is a risk factor for spina bifida and anencephaly that may provide a partial biologic explanation for why folic acid prevents these types of NTD. 13 refs., 1 fig., 1 tab.

  20. [Association between methylene-tetrahydrofolate reductase gene polymorphisms and chronic myeloid leukemia].

    PubMed

    Dorgham, Samia; Aberkane, Meriem; Boughrara, Wefa; Antar Soltan, Badra; Mehalhal, Nemra; Touhami, Hadj; Sidimansour, Noureddine; Merad Boudia, Nadia; Louhibi, Lotfi; Boudjema, Abdallah

    2014-09-01

    Methylene-tetrahydrofolate reductase (MTHFR) is a key enzyme of folate metabolism. Few studies were reported about its relationship with chronic myeloid leukemia (CML). We conducted a case-control study analyzing the prevalence of the polymorphisms MTHFR C677T and MTHFR A1298C in Algerians CML patients. Using TaqMan(®) allelic discrimination assay, we investigate MTHFR C677T and A1298C polymorphism distribution in 90 cases of CML and 100 healthy subjects. The frequencies of 677T alleles and genotypes 677TT and 677CT were significantly higher in cases than in control (P = 1E-6; OR = 6.77 [4.22-10.86]) and (P = 1E-6; OR = 10.38 [4.56-23.6]) respectively. Also, the frequencies of 1298C alleles and genotypes 1298CC and 1298AC were higher in cases (P = 9 E-6; OR = 2.65 [1.71-4.10]) and (P = 0.008; OR = 2.22 [1.21-4.06]) respectively. We report also the higher significance of the haplotype 677T/1298A and 677T/1298C in cases (P = 0.007; OR = 2.57 [1.26-5.24]) and (P = 5 E-6, OR = 6.91 [2.7646-17.2899]) respectively. Our results demonstrate that 677T and 1298C alleles are both associated with an increased risk of CML in Algeria.

  1. Methylenetetrahydrofolate reductase gene C677T polymorphism and breast cancer risk: Evidence for genetic susceptibility

    PubMed Central

    Kumar, Pradeep; Yadav, Upendra; Rai, Vandana

    2015-01-01

    There are several evidences supporting the role of 5–10 methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms in breast cancer (BC). Case control association studies on breast cancer have been repeatedly performed over the last two decades, but results are inconsistent. We performed a meta-analysis to confirm the association between MTHFR C677T polymorphism and BC risk. The articles were retrieved by searching the PubMed, Google Scholar, and Springer Link databases. Crude odds ratios (OR) with 95% confidence intervals (CIs) was used to assess the strength of association between C677T polymorphism and BC. Publication bias was assessed by Egger's and Begg-Mazumdar tests. Meta-analysis was performed with Open Meta Analyst. Total 75 studies with 31,315 cases and 35, 608 controls were found suitable for the inclusion in the present meta-analysis. The results of meta-analysis suggested that there were moderate significant association between C677T polymorphism and BC risk using overall comparisons in five genetic models (T vs. C: OR = 1.08, 95% CI = 1.03–1.13, p = < 0.001; TT + CT vs. CC: OR = 1.06, 95% CI = 1.02–1.09, p = < 0.001; TT vs. CC: OR = 1.17, 95% CI = 1.06–1.28, p = 0.001; CT vs. CC OR = 1.05, 95% CI = 1.01–1.08, p = 0.005; TT vs. CT + CC: OR = 1.12, 95% CI = 1.03–1.22, p = 0.005). In conclusion, results of present meta-analysis showed modest association between MTHFR C677T polymorphism with breast cancer in total studies. However, sub-group analysis results based on ethnicity showed strong significant association between TT genotype and breast cancer (TT vs. CC; OR°=°1.26; 95% CI: 1.06–1.51; p = 0.009) in Asian population but in Caucasian population such association was not observed (TT vs. CC; OR°=°1.08; 95% CI: 0.99–1.14; p = 0.05). PMID:26629412

  2. Methylenetetrahydrofolate reductase gene C677T polymorphism and breast cancer risk: Evidence for genetic susceptibility.

    PubMed

    Kumar, Pradeep; Yadav, Upendra; Rai, Vandana

    2015-12-01

    There are several evidences supporting the role of 5-10 methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms in breast cancer (BC). Case control association studies on breast cancer have been repeatedly performed over the last two decades, but results are inconsistent. We performed a meta-analysis to confirm the association between MTHFR C677T polymorphism and BC risk. The articles were retrieved by searching the PubMed, Google Scholar, and Springer Link databases. Crude odds ratios (OR) with 95% confidence intervals (CIs) was used to assess the strength of association between C677T polymorphism and BC. Publication bias was assessed by Egger's and Begg-Mazumdar tests. Meta-analysis was performed with Open Meta Analyst. Total 75 studies with 31,315 cases and 35, 608 controls were found suitable for the inclusion in the present meta-analysis. The results of meta-analysis suggested that there were moderate significant association between C677T polymorphism and BC risk using overall comparisons in five genetic models (T vs. C: OR = 1.08, 95% CI = 1.03-1.13, p = < 0.001; TT + CT vs. CC: OR = 1.06, 95% CI = 1.02-1.09, p = < 0.001; TT vs. CC: OR = 1.17, 95% CI = 1.06-1.28, p = 0.001; CT vs. CC OR = 1.05, 95% CI = 1.01-1.08, p = 0.005; TT vs. CT + CC: OR = 1.12, 95% CI = 1.03-1.22, p = 0.005). In conclusion, results of present meta-analysis showed modest association between MTHFR C677T polymorphism with breast cancer in total studies. However, sub-group analysis results based on ethnicity showed strong significant association between TT genotype and breast cancer (TT vs. CC; OR°=°1.26; 95% CI: 1.06-1.51; p = 0.009) in Asian population but in Caucasian population such association was not observed (TT vs. CC; OR°=°1.08; 95% CI: 0.99-1.14; p = 0.05).

  3. Methionine synthase A2756G polymorphism may predict ulcerative colitis and methylenetetrahydrofolate reductase C677T pancolitis, in Central China

    PubMed Central

    Chen, Min; Peyrin-Biroulet, Laurent; Xia, Bing; Guéant-Rodriguez, Rosa-Maria; Bronowicki, Jean-Pierre; Bigard, Marc-André; Guéant, Jean-Louis

    2008-01-01

    Background The association of genetic polymorphisms related to metabolism of homocysteine with inflammatory bowel disease has been evidenced in Crohn disease and remains an open question in ulcerative colitis. We evaluated the association of the polymorphisms of MTHFR, MTR, MTRR and TCN2 genes with ulcerative colitis in Central China. Methods 168 patients were genotyped for these polymorphisms and compared to 219 matched controls. Results Methionine synthase 2756G allele frequency was higher in ulcerative colitis than in controls 0.15 (95% C.I. 0.11–0.19) vs 0.09 (95% C.I. 0.07 – 0.12), (P = 0.0137) and predicted ulcerative colitis risk in logistic regression, with an Odds ratio at 1.8 (95% C.I. 1.15–2.84). Methylenetetrahydrofolate reductase 677TT genotype was 2.7-fold more prevalent in individuals with pancolitis than in those with left colitis or proctitis, with respective percentages of 27.3 (95% C.I.16.4–42.0) and 10.5 (95% C.I. 6.3–17.1) (P = 0.0123). The carriage of 677TT or 677CT/1298AC genotypes of methylenetetrahydrofolate reductase was more frequent in cases with pancolitis than in subjects with left colitis or proctitis (P = 0.0048), with an Odds ratio adjusted by age and sex at 3.3 (95% C.I. 1.4–7.9), P = 0.0084) in logistic regression. Conclusion Methionine synthase and methylenetetrahydrofolate reductase are genes of vitamin B12 and folate cellular metabolism associated respectively with risk and extent of ulcerative colitis, at least in Central China. This finding may open new insights, particularly for the potential interest in treating patients carrying the 677TT MTHFR genetic trait and a deficit in folate. PMID:18700049

  4. Relationship between genetic polymorphisms of methylenetetrahydrofolate reductase and breast cancer chemotherapy response.

    PubMed

    Yang, L; Wang, X W; Zhu, L P; Wang, H L; Wang, B; Wu, T; Zhao, Q; JinSiHan, D L X T; Wang, X Y

    2016-09-23

    Activity of methylenetetrahydrofolate reductase (MTHFR), an enzyme involved in folate metabolism, is influenced by mutations in the corresponding gene, contributing to a decrease in 5,10-MTHF. Due to such polymorphisms, individuals differ in MTHFR enzyme activity and plasma folate levels. We investigated the relationship between two common MTHFR polymorphisms (C677T and A1298C) and breast cancer (BC) chemotherapy response. From February 2013 to January 2016, 148 advanced BC patients at the Center Hospital of Cangzhou were enrolled and treated with six different chemotherapy regimens. Subjects were genotyped using polymerase chain reaction-restriction fragment length polymorphism. Forty-one (27.7%), 70 (47.3%), and 37 (25.0%) patients carried the C/C, C/T, and T/T C677T genotypes, respectively; 101 (68.2%), 42 (28.4%), and 5 (3.4%) had the A/A, A/C, and C/C genotypes of A1298C, respectively. Total chemotherapy efficacy was 66.9% (99/148), with 7 (4.7%), 92 (62.2%), 36 (24.3%), and 13 (8.8%) cases showing complete response, partial response, no change, and progressive disease, respectively. Chemotherapy regimens did not differ in effectiveness (P > 0.05). Efficacy rates associated with C677T C/C, C/T, and T/T genotypes were 58.5, 58.6, and 91.9%, respectively, with T/T carriers exhibiting significantly better responses than the C/C (P < 0.05) and C/T groups (P < 0.05). Effectiveness among A1298C A/A, A/C, and C/C carriers was 70.6, 64.3, and 0.0%, respectively, but no difference was established between these genotypes in this regard (P > 0.05). The MTHFR C677T genotype may be associated with BC chemotherapy response, and could be of great value in guiding individualized treatment for this disease.

  5. Methylenetetrahydrofolate Reductase C677T Polymorphism and Recurrent Pregnancy Loss Risk in Asian Population: A Meta-analysis.

    PubMed

    Rai, Vandana

    2016-10-01

    The C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene was implicated to be associated with thrombophilia due to its role in catalyzing the formation of 5-methylenetetrahydrofolate, a co-substrate for the conversion of homocysteine to methionine. Several case-control studies were investigated MTHFR C677T polymorphism as risk for recurrent pregnancy loss (RPL). These studies rendered contradictory results, some indicating that the polymorphism is associated with the risk of RPL whereas others concluded there is no association. To shed light on these inconclusive findings, a meta-analysis of all available studies published from Asian population relating the C677T polymorphism to the risk of RPL was conducted. The following electronic databases were searched without language restrictions: PubMed, Google Scholars, Elsevier and Springer Link up to December, 2015. Meta-analysis was performed using MetaAnalyst and Mix version 1.7. Meta-analysis results suggested that MTHFR C677T polymorphism contributed to the increased RPL risk in Asian population using all five genetic models (for T vs. C: OR 1.35, 95 % CI 1.09-1.68, p = 0.009; for TT + CT vs. CC: OR 1.44, 95 % CI 1.14-1.82, p = 0.006; for CT vs. CC: OR 1.39, 95 % CI 1.07-1.8, p = 0.01; for TT vs. CC: OR 1.79, 95 % CI 1.23.2.6, p = 0.007; for TT vs. CT + CC: OR 1.61, 95 % CI 1.02-2.56, p = 0.04). In conclusion, this meta-analysis demonstrates a strong association between the MTHFR C677T variant and RPL in Asian population and raising the importance of the use of folate in its treatment and prevention.

  6. Bladder exstrophy-epispadias complex and the role of methylenetetrahydrofolate reductase C677T polymorphism: A case control study

    PubMed Central

    Raman, Venkat Shankar; Bajpai, Minu; Ali, Abid

    2016-01-01

    Purpose: The Bladder Exstrophy-Epispadias Complex (BEEC) is the most serious form of midline abdominal malformation. The etiology of BEEC is unknown and is thought to be multifactorial. Methylenetetrahydrofolate reductase (MTHFR) polymorphism C677T is strongly associated with other midline abnormalities such as neural tube defects. No proper case-control study existed comparing MTHFR polymorphism with BEEC. We sought to find an association with MTHFR polymorphism and patients with bladder exstrophy (BE). Materials and Methods: The design of the study was a case-control study, involving 50 children with BEEC and 50 normal healthy school children. Genetic analysis for MTHFR 677 polymorphism was carried out after DNA extraction and polymerase chain reaction amplification. Epidemiological analysis was done by using the birth defect questionnaire on parents of BEEC. Results: Forty-two classical BE, two cloacal exstrophies (CE), four epispadias, and two exstrophy variant patients were a part of this study. Severe variety of BE had a significant association with C667T MTHFR polymorphism as compared to the normal control population (P = 0.01). Conclusion: C677T MTHFR polymorphism has a strong association with severe variety (CE) of BEEC occurrence. PMID:26862292

  7. Association of methylenetetrahydrofolate reductase (A1298C and C677T) polymorphisms with retinal vein occlusion in Tunisian patients.

    PubMed

    Mrad, Meriem; Wathek, Cheima; Saleh, Mekki Ben; Baatour, Makrem; Rannen, Riadh; Lamine, Khaled; Gabsi, Salem; Gritli, Nasreddine; Fekih-Mrissa, Najiba

    2014-04-01

    The role of two polymorphisms C677T and A1298C of the methylenetetrahydrofolate reductase (MTHFR) gene in the etiology of retinal vein occlusion (RVO) has not been adequately clarified. The aim of this study was to examine the prevalence of these polymorphisms among RVO Tunisian patients with and without systemic risk factors. Seventy-two patients with retinal vein occlusion (RVO) were studied. The control group included140 people matched for age, sex, and risk factors. Participants in the study were genotyped for the MTHFR C677T and A1298C polymorphisms. The genotyping was performed by PCR-RFLP. No significant differences were found in the frequencies of the three genotypes (AA, AC, CC) of the MTHFR A1298C polymorphism between RVO patients and healthy controls. However, the prevalence of the group of mutated genotypes (AC+CC) of the missense variant MTHFR A1298C was significantly different between patients and controls (16.67% vs. 6.42%, p=.01). Additionally, the frequency of the CT genotype as well as the group of combined mutated genotypes (CT+TT) for the C677T variant was significantly higher among RVO patients compared with controls (p<10(-3), p<10(-3)). This suggests an association between this polymorphism and RVO. Large study populations would be required to understand more completely the contribution of these markers in the risk of RVO.

  8. Meta-Prediction of the Effect of Methylenetetrahydrofolate Reductase Polymorphisms and Air Pollution on Alzheimer's Disease Risk.

    PubMed

    Wu, Suh-Mian; Chen, Zhao-Feng; Young, Lufei; Shiao, S Pamela K

    2017-01-11

    Background: Alzheimer's disease (AD) is a significant public health issue. AD has been linked with methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, but the findings have been inconsistent. The purpose of this meta-predictive analysis is to examine the associations between MTHFR polymorphisms and epigenetic factors, including air pollution, with AD risk using big data analytics approaches. Methods and Results: Forty-three studies (44 groups) were identified by searching various databases. MTHFR C677T TT and CT genotypes had significant associations with AD risk in all racial populations (RR = 1.13, p = 0.0047; and RR = 1.12, p < 0.0001 respectively). Meta-predictive analysis showed significant increases of percentages of MTHFR C677T polymorphism with increased air pollution levels in both AD case group and control group (p = 0.0021-0.0457); with higher percentages of TT and CT genotypes in the AD case group than that in the control group with increased air pollution levels. Conclusions: The impact of MTHFR C677T polymorphism on susceptibility to AD was modified by level of air pollution. Future studies are needed to further examine the effects of gene-environment interactions including air pollution on AD risk for world populations.

  9. Risk of colorectal cancer associated with the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in the Kashmiri population.

    PubMed

    Sameer, A S; Shah, Z A; Nissar, S; Mudassar, S; Siddiqi, M A

    2011-06-21

    Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme in folate metabolism and is involved in DNA synthesis, DNA repair and DNA methylation. The two common functional polymorphisms of MTHFR, 677 C→T and 1298 A→C, have been shown to impact various diseases, including cancer. The 677 C→T polymorphism has been widely investigated in different cancers and has been implicated as a risk factor for the development of various cancers. We investigated MTHFR C677T genotype frequency in colorectal cancer cases in the Kashmiri population and correlated this information with the known clinicopathological characters of colorectal cancer, in a case-control study. Eighty-six colorectal cancer cases were studied for MTHFR C677T polymorphism, compared to 160 controls taken from the general population, employing the PCR-RFLP technique. We found the frequency of the three different genotypes of MTHFR in our ethnic Kashmir population, i.e., CC, CT and TT, to be 68.6, 20.9 and 10.4% among colorectal cancer cases and 75.6, 16.9 and 7.5% among the general control population, respectively. There was a significant association between the MTHFR TT genotype and colorectal cancer in the higher age group. We conclude that the MTHFR C677T polymorphism slightly increases the risk for colorectal cancer development in our ethnic Kashmir population.

  10. Meta-Prediction of the Effect of Methylenetetrahydrofolate Reductase Polymorphisms and Air Pollution on Alzheimer’s Disease Risk

    PubMed Central

    Wu, Suh-Mian; Chen, Zhao-Feng; Young, Lufei; Shiao, S. Pamela K.

    2017-01-01

    Background: Alzheimer’s disease (AD) is a significant public health issue. AD has been linked with methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, but the findings have been inconsistent. The purpose of this meta-predictive analysis is to examine the associations between MTHFR polymorphisms and epigenetic factors, including air pollution, with AD risk using big data analytics approaches. Methods and Results: Forty-three studies (44 groups) were identified by searching various databases. MTHFR C677T TT and CT genotypes had significant associations with AD risk in all racial populations (RR = 1.13, p = 0.0047; and RR = 1.12, p < 0.0001 respectively). Meta-predictive analysis showed significant increases of percentages of MTHFR C677T polymorphism with increased air pollution levels in both AD case group and control group (p = 0.0021–0.0457); with higher percentages of TT and CT genotypes in the AD case group than that in the control group with increased air pollution levels. Conclusions: The impact of MTHFR C677T polymorphism on susceptibility to AD was modified by level of air pollution. Future studies are needed to further examine the effects of gene-environment interactions including air pollution on AD risk for world populations. PMID:28085050

  11. Impact of methionine synthase gene and methylenetetrahydrofolate reductase gene polymorphisms on the risk of sudden sensorineural hearing loss.

    PubMed

    Gross, Menachem; Friedman, Gideon; Eliashar, Ron; Koren-Morag, Nira; Goldschmidt, Neta; Atta, Iman Abou; Ben-Yehuda, Arie

    2006-01-01

    Idiopathic sudden sensorineural hearing loss (SSNHL) represents a frequently encountered otological disease of unknown etiology. In recent years, several inherited risk factors have been found in the pathogenesis of vascular diseases. In the present study, we determined whether specific polymorphism or the combination of polymorphisms in folate-dependent homocysteine metabolism genes can act as predisposing inherited vascular risk factors in the development of SSNHL. We conducted a prospective case-control study using DNA samples extracted from 81 patients diagnosed as suffering from SSNHL and 264 healthy control subjects. Three functional polymorphisms were analyzed by polymerase chain reaction amplification, restriction enzyme digestion, and DNA fragment separation by electrophoresis: methylenetetrahydrofolate reductase (MTHFR) C677T, MTHFR A1298C, and methionine synthase (MTR) A2756G polymorphisms. The prevalence of the homozygous genotype of MTR 2756GG in the SSNHL patients (9%) was significantly higher than in the control group (4%) (p = 0.011). The allelic frequency of the G allele of the MTR A2756G polymorphism among SSNHL patients (12.5%) was also significantly higher than in the control group (5%) (p = 0.033). The prevalence of patients possessing two polymorphisms (31%) and three polymorphisms (17%) in the SSNHL group was significantly higher than in the control group (23 and 9%, respectively; p = 0.019). The frequency of patients with a very high rank risk (double homozygous) was significantly higher in the SSNHL group, MTHFR 677TT/MTR 2675GG--7%, than the frequency of patients in the control group, MTHFR 677TT/MTR 2675GG--3% (p = 0.030). Certain polymorphisms in genes encoding enzymes in the folate-dependent homocysteine metabolism are associated with SSNHL. In our case-control study, a significant association between MTR 2756GG genotype and SSNHL was found which may represent an inherited vascular risk factor in the pathogenesis of SSNHL.

  12. Methylenetetrahydrofolate reductase genetic polymorphisms and esophageal squamous cell carcinoma susceptibility: A meta-analysis of case-control studies

    PubMed Central

    Shujuan, Yang; Jianxing, Zhang; Xin-yue, Chen

    2013-01-01

    Objectives: Genetic factors and environmental factors play a role in pathogenesis of esophageal squamous cell carcinoma (ESCC). Previous studies regarding the association of folate intake and Methylenetetrahydrofolate reductase C677T polymorphism with ESCC was conflicting. We conducted a meta-analysis to investigate the association of MTHFR C677T and folate intake with esophageal cancer risk. Methodology: MEDLINE, EMBASE and the Chinese Biomedical Database were searched in our study. The quality of studies were evaluated by predefined scale, and The association of polymorphisms of MTHFR C677T and folate intake and ESCC risk was estimated by Odds ratio (ORs) with 95% confidence intervals (CIs). Results: Nineteen studies (4239 cases and 5575 controls) were included for meta-analysis. A significant association was seen between individuals with MTHFR 677 CT [OR(95%)=1.47(1.32-1.63)] and TT [OR(95%)=1.69(1.49-1.91)] genotypes and ESCC risk (p<0.05). Low intake of folate had significantly higher risk of esophageal cancer among individuals with CT/TT genotype [OR(95%)=1.65(1.1-2.49)], while high intake of folate did not find significant high risk of esophageal cancer among individuals with CT/TT genotype [OR(95%)=1.64 (0.82-3.26)]. Conclusions: Our meta-analysis indicated the folate intake and MTHFR 677CT/TT are associated with the risk of ESCC, and folate showed a significant interaction with polymorphism of MTHFR C677T. PMID:24353609

  13. Methylenetetrahydrofolate reductase C677T polymorphism and Factor V Leiden variant in Mexican women with preeclampsia/eclampsia.

    PubMed

    Dávalos, I P; Moran, M C; Martínez-Abundis, E; González-Ortiz, M; Flores-Martínez, S E; Machorro, V; Sandoval, L; Figuera, L E; Mena, J P; Oliva, J M; Tlacuilo-Parra, J A; Sánchez-Corona, J; Salazar-Páramo, M

    2005-01-01

    The etiology of preeclampsia is still a matter of controversy. An association between hyperhomocysteinemia and preeclamptic patients has been described. A common missense mutation in the methylenetetrahydrofolate reductase (MTHFR) gene is associated with increased plasma homocysteine concentrations. In addition, the polymorphism of gene encoding for Factor V Leiden G1691A is associated with a prothrombotic state in heterozygous subjects. Both mutations in these thrombophilic proteins appear to have different prevalence in the general population and in patients with preeclampsia/eclampsia (PE/E). We studied single nucleotide polymorphisms for MTHFR C677T and coagulation Factor V Leiden in 33 Mexican patients with PE/E as a genetic risk factor for these diseases, comparing with a normotensive pregnant control group. The genotype and allele frequencies of MTHFR C677T and Factor V Leiden mutations between Mexican women with PE/E and healthy controls were not different. We conclude that these polymorphisms do not contribute in the etiology of PE/E as it has been reported in other populations.

  14. The relationship between methylenetetrahydrofolate reductase C677T gene polymorphism and diabetic nephropathy in Croatian type 2 diabetic patients.

    PubMed

    Tomić, Nives Gojo; Marusić, Srećko; Bozikov, Velimir; Kusec, Rajko; Bacić-Vrca, Vesna; Tadić, Mario

    2013-09-01

    Methylenetetrahydrofolate reductase (MTHFR) polymorphism has been shown to be associated with the development of diabetic nephropathy in many ethnic groups. In this study, we examined the correlation between MTHFR C677T polymorphism and microalbuminuria in patients with diabetes mellitus type 2 in Croatian patients. 85 patients with diabetes mellitus type 2 were recruited. Patients were classified into two groups--with and without diabetic nephropathy according to urinary albumin excretion rate in urine collected during 24 hours. The C677T genotype was determined by real-time PCR analysis. The genotype frequencies were CC 36.5%, CT 42.3% and TT 21.2% in diabetic patients without nephropathy versus CC 39.4%, CT 45.4% and TT 15.2% in those with nephropathy. There was no statistically significant difference in allele distribution between patients with nephropathy and those without (p = 0.788). Our study did not show a correlation between mutations in the MTHFR gene and diabetic nephropathy in Croatian patients. Diabetic nephropathy is influenced by multiple risk factors which can modify the importance of MTHFR polymorphism in its development.

  15. Relationship between methylenetetrahydrofolate reductase (MTHFR) A1298C gene polymorphism and type 2 diabetic nephropathy risk: a meta-analysis.

    PubMed

    Zhang, Jie; Xiao, Yan; Zhang, Xian-Wen; Gao, Zhi-Qing; Han, Jing-Hui

    2014-07-01

    Relationship between methylenetetrahydrofolate reductase (MTHFR) A1298C gene polymorphism and type 2 diabetic nephropathy (T2DN) risk is still unclear. This study was performed to evaluate if there is an association between the MTHFR A1298C gene polymorphism and T2DN risk using meta-analysis. The relevant reports were searched and identified from PubMed, Cochrane Library on 1 October 2013, and eligible studies were included and synthesized. Eight reports were recruited into this meta-analysis for the association of the MTHFR A1298C gene polymorphism with T2DN risk. The MTHFR A1298C C allele or CC genotype was shown to be not associated with T2DN risk (C allele: OR = 0.76, 95% CI: 0.43-1.34, p = 0.34; CC genotype: OR = 1.18, 95% CI: 0.63-2.22, p = 0.60). Interestingly, AA genotype was associated with the T2DN risk (OR = 0.68, 95% CI: 0.49-0.96, p = 0.03). In the sensitivity analysis according to the Hardy-Weinberg equilibrium (HWE), the results were consistent with those in non-sensitivity analysis. However, in the sensitivity analysis according to the control source from hospital, sample size of case (≥ 100), sample size of case (<100), the MTHFR A1298C gene polymorphism was not associated with T2DN risk. In conclusion, the MTHFR A1298C gene polymorphism was not associated with T2DN risk. However, additional studies are required to firmly establish a correlation between the MTHFR A1298C gene polymorphism and T2DN risk.

  16. Impact of methylenetetrahydrofolate reductase (MTHFR) polymorphisms on methotrexate-induced toxicities in acute lymphoblastic leukemia: a meta-analysis.

    PubMed

    Yang, Lin; Hu, Xin; Xu, Luhang

    2012-10-01

    The associations between methylenetetrahydrofolate reductase (MTHFR) polymorphism and methotrexate (MTX)-induced toxicities in patients with acute lymphoblastic leukemia (ALL) have been evaluated in various populations, with the results remained conflicting. Therefore, we conducted a meta-analysis by combining available data to derive a more precise estimation of the association. PubMed, Embase, and China National Knowledge Infrastructure were searched until 21 September 2011 to identify eligible studies. A total of 14 studies were included, with all studies investigating MTHFR C677T polymorphism while nine of them investigating MTHFR A1298C polymorphism only. Results suggested that MTHFR C677T polymorphism was associated with significantly increased risk of MTX-induced toxicity, specifically liver toxicity (TT/CT vs. CC: odds ratio (OR) = 1.70, 95 % confidence interval (CI) = 1.05-2.75), myelosuppression (TT vs. CT/CC: OR = 2.82, 95 %CI = 1.25-6.34), oral mucositis (TT/CT vs. CC: OR = 3.68, 95 %CI = 1.73-7.85), gastrointestinal toxicity (TT/CT vs. CC: OR = 2.36, 95 %CI = 1.36-4.11), and skin toxicity (T vs. C: OR = 2.26, 95 %CI = 1.07-4.74). MTHFR A1298C polymorphism was found to be associated with decreased risk of skin toxicity (CC/AC vs. AA: OR = 0.11, 95 %CI = 0.01-0.85). Genotyping of MTHFR polymorphism, C677T particularly, prior to treatment for ALL is likely to be useful with the aim of tailoring MTX therapy and thus reducing the MTX-related toxicities. However, further studies with larger data set and well-designed models are required to validate our findings.

  17. Methylenetetrahydrofolate Reductase A1298C Polymorphism and Breast Cancer Risk: A Meta-analysis of 33 Studies

    PubMed Central

    Rai, V

    2014-01-01

    Methylenetetrahydrofolate reductase (MTHFR) enzyme is essential for DNA synthesis and DNA methylation, and its gene polymorphisms have been implicated as risk factors for birth defects, neurological disorders, and different types of cancers. Several studies have investigated the association between the MTHFR A1298C polymorphism and breast cancer (BC) risk, but the results were inconclusive. To assess the risk associated with MTHFR A1298C polymorphism, a comprehensive meta-analysis was performed. PubMed, Google Scholar, Elsevier and Springer Link databases were searched for case-control studies relating the association between MTHFR A1298C polymorphism and BC risk and estimated summary odds ratios (ORs) with confidence intervals (CIs) for assessment. Up to January 2014, 33 case-control studies involving 15,919 BC patients and 19,700 controls were included in the present meta-analysis. The results showed that the A1298C polymorphism was not associated with BC risk in all the five genetic models (C vs. A allele (allele contrast): OR = 0.99, 95% confidence interval (CI): 0.93–1.05; AC versus AA (heterozygote/codominant): OR = 0.97, 95% CI: 0.89–1.04; CC versus AA (homozygote): OR = 0.99, 95% CI: 0.91–1.06; CC + AC versus AA (dominant model): OR = 0.97, 95% CI: 0.90–1.05; and CC versus AC + AA (recessive model): OR = 0.99, 95% CI: 0.91–1.07). The present meta-analysis did not support any association between the MTHFR A1298C polymorphism and BC risk. PMID:25506474

  18. Polymorphisms of 5,10-methylenetetrahydrofolate reductase and thymidylate synthase, dietary folate intake, and the risk of leukemia in adults.

    PubMed

    Liu, Ping; Zhang, Min; Xie, Xing; Jin, Jie; Holman, C D'Arcy J

    2016-03-01

    The 5,10-methylenetetrahydrofolate reductase (MTHFR) and thymidylate synthase (TS) are critical enzymes in folate metabolism. Previous studies have reported conflicting results on the associations between MTHFR/TS polymorphisms and adult leukemia risk, which may due to the lack of information on folate intake. We investigated the risks of adult leukemia with genetic polymorphisms of folate metabolic enzymes (MTHFR C677T, A1298C, and TS) and evaluated if the associations varied by dietary folate intake from a multicenter case-control study conducted in Chinese. This study comprised 442 incident adult leukemia cases and 442 outpatient controls, individually matched to cases by gender, birth quinquennium, and study site. Genotypes were determined by a polymerase chain reaction (PCR) or PCR-based restriction fragment length polymorphism assay. Dietary folate intake was assessed by face-to-face interviews using a validated food-frequency questionnaire. The MTHFR 677TT genotype conferred a significant higher risk of leukemia in males than in females and exhibited an increased risk of acute myeloid leukemia (AML) but a decreased risk of acute lymphoblastic leukemia (ALL). The MTHFR 1298AC genotype appeared to decrease the risks of leukemia in both genders, in AML and ALL. Stratified analysis by dietary folate intake showed the increased risks of leukemia with the MTHFR 677TT and TS 2R3R/2R2R genotypes were only significant in individuals with low folate intake. A significant interaction between TS polymorphism and dietary folate intake was observed (P = 0.03). This study suggests that dietary folate intake and gender may modify the associations between MTHFR/TS polymorphisms and adult leukemia risk.

  19. Thermolabile Methylenetetrahydrofolate Reductase C677T Polymorphism and Homocysteine Are Risk Factors for Coronary Artery Disease in Moroccan Population

    PubMed Central

    Bennouar, Nawal; Allami, Abdellatif; Azeddoug, Houssine; Bendris, Abdenbi; Laraqui, Abdelilah; El Jaffali, Amal; El Kadiri, Nizar; Benzidia, Rachid; Benomar, Anwar; Fellat, Seddik; Benomar, Mohamed

    2007-01-01

    Increased plasma total homocysteine (tHcy) levels have been shown to be a risk factor for coronary artery disease (CAD). The common methylenetetrahydrofolate reductase C677T (MTHFR C677T) polymorphism has been reported to be a strong predictor of mild hyperhomocysteinaemia (HHcy). We assessed whether this mutation was associated with increased risk of CAD and plasma levels of tHcy. We also evaluated interactions between this polymorphism, mild elevated tHcy levels and conventional risk factors of CAD. Method. Using PCR-RFLP analysis, we studied the frequency of the C677T genotypes and its effect on CAD and on tHcy concentrations in 400 subjects without and with CAD angiographically confirmed. There were 210 subjects with CAD and 190 subjects without CAD. Results. The frequencies of the C677T genotypes were 53% (59.5% in controls versus 48.1% in cases), 34.8% (32.1 in controls versus 37.1 in cases), and 11.8% (8.4% in controls versus 14.8% in cases), respectively, for 677CC, 677CT, and 677TT. The genotype frequencies were significantly different between case and control groups (P < .05). The 677T allele enhances the risk of CAD associated to HHcy (P < .01). In multivariate analysis models, MTHFR C677T polymorphism effect on CAD was masked by other risk factors. HHcy was only and independently influenced by MTHFR polymorphism and smoking habits, and it is a strong predictor of CAD independently of conventional risk factors. Conclusion. Our data suggest that HHcy is strongly and independently associated to CAD risk increase; and MTHFR C677T polymorphism and smoking habits were the main predictors of tHcy levels. The CAD risk increase is mainly associated with mild HHcy in 677TT, whereas in 677CT and 677CC it is mainly associated with the conventional risk factors. PMID:17497026

  20. Methylenetetrahydrofolate reductase C677T and methionine synthase A2756G polymorphisms influence on leukocyte genomic DNA methylation level.

    PubMed

    Weiner, Alexandra S; Boyarskikh, Uljana A; Voronina, Elena N; Mishukova, Olga V; Filipenko, Maxim L

    2014-01-01

    Methionine synthase (MTR) and methylenetetrahydrofolate reductase (MTHFR) enzymes are involved in the metabolism of methyl groups, and thus have an important role in the maintenance of proper DNA methylation level. In our study we aimed to evaluate the effect of the polymorphism A2756G (rs1805087) in the MTR gene on the level of human leukocyte genomic DNA methylation. Since the well-studied polymorphism C677T (rs1801133) in the MTHFR gene has already been shown to affect DNA methylation, we aimed to analyze the effect of MTR A2756G independently of the MTHFR C677T polymorphism. For this purpose, we collected the groups of 80 subjects with the MTR 2756AA genotype and 80 subjects with the MTR 2756GG genotype, having equal numbers of individuals with the MTHFR 677CC and the MTHFR 677TT genotypes, and determined the level of DNA methylation in each group. Individuals homozygous for the mutant MTR 2756G allele showed higher DNA methylation level than those harboring the MTR 2756AA genotype (5.061 ± 1.761% vs. 4.501 ± 1.621%, P=0.0391). Individuals with wild-type MTHFR 677СC genotype displayed higher DNA methylation level than the subjects with mutant MTHFR 677TT genotype (5.103 ± 1.767% vs. 4.323 ± 1.525%, P=0.0034). Our data provide evidence that the MTR A2756G polymorphism increases the level of DNA methylation and confirm the previous reports that the MTHFR C677T polymorphism is associated with DNA hypomethylation.

  1. Maternal Methylenetetrahydrofolate Reductase C677T Polymorphism and Down Syndrome Risk: A Meta-Analysis from 34 Studies

    PubMed Central

    Rai, Vandana; Yadav, Upendra; Kumar, Pradeep; Yadav, Sushil Kumar; Mishra, Om Prakesh

    2014-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of folate metabolic pathway which catalyzes the irreversible conversion of 5, 10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. 5-methyltetrahydrofolate donates methyl group for the methylation of homocysteine to methionine. Several studies have investigated maternal MTHFR C677T polymorphism as a risk factor for DS, but the results were controversial and inconclusive. To come into a conclusive estimate, authors performed a meta-analysis. Aim A meta-analysis of published case control studies was performed to investigate the association between maternal MTHFR C677T polymorphism and Down syndrome. Methods PubMed, Google Scholar, Elsevier, Springer Link databases were searched to select the eligible case control studies using appropriate keywords. The pooled odds ratio (OR) with 95%confidence interval were calculated for risk assessment. Results Thirty four studies with 3,098 DS case mothers and 4,852 control mothers were included in the present meta-analysis. The pooled OR was estimated under five genetic models and significant association was found between maternal MTHFR 677C>T polymorphism and Down syndrome under four genetic models except recessive model (for T vs. C, OR = 1.26, 95% CI = 1.09–1.46, p = 0.001; for TT vs. CC, OR = 1.49, 95% CI = 1.13–1.97, p = 0.008; for CT vs. CC, OR = 1.29, 95% CI = 1.10–1.51, p = 0.001; for TT+CT vs. CC, OR = 1.35, 95% CI = 1.13–1.60, p = 0.0008; for TT vs. CT+CC, OR = 0.76, 95% CI = 0.60–0.94, p = 0.01). Conclusion The results of the present meta-analysis support that maternal MTHFR C677T polymorphism is a risk factor for DS- affected pregnancy. PMID:25265565

  2. Methylenetetrahydrofolate reductase gene polymorphisms are associated with ischemic and hemorrhagic stroke: Dual effect of MTHFR polymorphisms C677T and A1298C.

    PubMed

    Sazci, Ali; Ergul, Emel; Tuncer, Nese; Akpinar, Gurler; Kara, Ihsan

    2006-12-11

    Hyperhomocysteinemia is an independent risk factor for ischemic stroke. The enzyme methylenetetrahydrofolate reductase (MTHFR) plays a critical role in modulating the levels of plasma homocysteine. Two polymorphisms in the MTHFR gene, C677T, A1298C result in reduced enzyme activity. The mechanisms of ischemic and hemorrhagic stroke are not well understood. Although controversial, previous studies have shown evidence of causality of both stroke subtypes in patients with methylenetetrahydrofolate reductase gene polymorphisms. Therefore, we examined whether the C677T and A1298C polymorphisms of MTHFR gene are genetic risk factors for both ischemic and hemorrhagic stroke in a Turkish Caucasian population. In a case-control study, 120 total unrelated stroke patients (92 ischemic stroke, 28 hemorrhagic stroke), and 259 healthy controls were genotyped for C677T and A1298C polymorphisms of the MTHFR gene using a PCR-RFLP based-method. The MTHFR 1298C allele (chi(2)=8.589; P=0.014), C1298C genotype (OR=2.544; P=0.004), and C677C/C1298C compound genotype (OR=3.020; P=0.001) were associated with overall stroke. The MTHFR 1298C allele (chi(2)=11.166; P=0.004), C1298C genotype (OR=2.950; P=0.001), and C677C/C1298C compound genotype (OR=3.463, P=0.0001) were strongly associated with ischemic stroke. Interestingly however, the MTHFR 677T allele (chi(2)=6.033; P=0.049), T677T genotype (OR=3.120; P=0.014), and T677T/A1298A compound genotype (OR=4.211; P=0.002) were associated with hemorrhagic stroke. In conclusion, the C677T and A1298C polymorphisms of the MTHFR gene are genetic risk factors for hamorrhagic and ischemic stroke respectively, independent of other atherothrombotic risk factors.

  3. The methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and tumor risk: evidence from 134 case-control studies.

    PubMed

    Tang, Min; Wang, Shang-Qian; Liu, Bian-Jiang; Cao, Qiang; Li, Bing-Jie; Li, Peng-Chao; Li, Yong-Fei; Qin, Chao; Zhang, Wei

    2014-07-01

    Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism, which is essential for DNA synthesis and methylation. Genetic variations in the MTHFR gene seem to contribute to a decreased activity of MTHFR, ultimately confer increased susceptibility to cancer. As the most extensively studied polymorphism, MTHFR C677T polymorphism was shown to contribute to cancer susceptibility but the results were inconsistent. The authors performed a meta-analysis including 134 studies (46,207 cases and 69,160 controls) to address the issue. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to assess the association. Overall, a significant elevated risk of cancer was associated with the MTHFR C677T polymorphism in T-allele versus C-allele comparison (OR = 1.06, 95% CI 1.02-1.11, P(heterogeneity) < 0.001), homozygote model (OR = 1.08, 95% CI 1.01-1.17, P(heterogeneity) < 0.001) and dominant model (OR = 1.05, 95% CI 1.00-1.10, P(heterogeneity) < 0.001). In the stratified analyses, significantly increased cancer risks were indicated among Asians in all genetic models except for heterozygote model. Further analysis revealed that C677T was significantly associated with an increased risk of esophageal and stomach cancer. This meta-analysis supports an association between the MTHFR C677T polymorphism and increased risk of esophageal and stomach cancer, especially among Asians. Additionally, more high-quality studies and that the covariates responsible for heterogeneity should be controlled to obtain a more conclusive response about the function of MTHFR C677T in cancer.

  4. Association between the methylenetetrahydrofolate reductase gene C677T polymorphism and sudden sensorineural hearing loss: a meta-analysis.

    PubMed

    Shu, Jingcheng; Yin, Shihua; Tan, An-Zhou; He, Meirong

    2015-09-01

    A variety of epidemiological studies have evaluated the association between methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and sudden sensorineural hearing loss (SSNHL), but the results were inconsistent. The aim of this meta-analysis was to clarify more accurately the association of this polymorphism with SSNHL. A systematic literature search of the associated studies up to May 1, 2014, was conducted using the following electronic databases: PubMed, Embase, Medline, and the China National Knowledge Infrastructure. Statistical analyses were performed by STATA12.0 software, with odds ratios (ORs) and their 95 % confidence intervals (CIs). Six eligible studies including covering 1,271 objects were identified. A pooled analysis of these studies showed no significant association between C677T polymorphism and risk of SSNHL: T vs. C (OR = 1.334, POR = 0.105); TT vs. CC (OR = 1.580, POR = 0.231); CT vs. CC (OR = 1.500, POR = 0.123); TT vs. CC + CT (OR = 1.326, POR = 0.293); and TT + CT vs. CC (OR = 1.540, POR = 0.102). But in subgroup analysis, a significant association was found in European populations (T vs. C, OR = 1.542, 95 % CI 1.008-2.359, P = 0.046; TT vs. CT + CC, OR = 1.856, 95 % CI 1.245-2.767, P = 0.002). There was no significant association in any model in the Asian populations. The present meta-analysis suggests that MTHFR gene C677T polymorphism is significantly associated with increased risk of SSNHL disease in European populations, but no statistically significant association was found between the MTHFR C677T gene mutation and SSNHL in Asian. Further large and well-designed studies are needed to confirm this association.

  5. A Meta-Analysis of Association between Methylenetetrahydrofolate Reductase Gene (MTHFR) 677C/T Polymorphism and Diabetic Retinopathy

    PubMed Central

    Luo, Shasha; Wang, Furu; Shi, Chao; Wu, Zhifeng

    2016-01-01

    Aims: To shed light on the conflicting findings of the association between the methylenetetrahydrofolate reductase gene (MTHFR) 677C/T polymorphism and the risk of diabetic retinopathy (DR), a meta-analysis was conducted. Methods: A predefined search was performed on 1747 DR cases and 3146 controls from 18 published studies by searching electronic databases and reference lists of relevant articles. A random-effects or fixed-effects model was used to estimate the sizes of overall and stratification effects of the MTHFR 677C/T polymorphism on the risk of DR, as appropriate. Results: Risks were evaluated by odds ratios (OR) with 95% confidence intervals (95% CI). We found a significant association between the MTHFR 677C/T polymorphism and the risk of DR for each genetic model (recessive model: OR = 1.67; 95% CI: 1.19–2.40 and dominant model: OR = 1.71; 95% CI: 1.28–2.28; respectively). In stratified analysis; we further found that the Asian group with both types of diabetes mellitus (DM) showed a significant association with genetic models (recessive model: OR = 2.16; 95% CI: 1.75–2.60 and dominant model: OR = 1.98; 95% CI: 1.42–2.76; respectively). Conclusions: Our study suggested that the MTHFR 677C/T polymorphism may contribute to DR development, especially in Asian populations. Prospective and additional genome-wide association studies (GWAS) are needed to clarify the real role of the MTHFR gene in determining susceptibility to DR. PMID:27517946

  6. Is the C677T polymorphism in methylenetetrahydrofolate reductase gene or plasma homocysteine a risk factor for diabetic peripheral neuropathy in Chinese individuals?☆

    PubMed Central

    Wang, Hongli; Fan, Dongsheng; Hong, Tianpei

    2012-01-01

    The present study enrolled 251 diabetic patients, including 101 with neuropathy and 150 without neuropathy. Of the 150 patients, 100 had no complications, such as retinopathy, nephropathy, or neuropathy. Polymerase chain reaction-restriction fragment length polymorphism analysis was used to identify methylenetetrahydrofolate reductase gene variants. Plasma homocysteine levels were also measured. Homocysteine levels and the frequency of hyperhomocysteinemia were significantly higher in patients with diabetic peripheral neuropathy compared with diabetic patients without neuropathy (P < 0.05). In logistic regression analysis with neuropathy as the dependent variable, the frequency of C677T in methylenetetrahydrofolate reductase was significantly higher in patients with diabetic peripheral neuropathy compared with patients without diabetic complications. Homocysteine levels were significantly higher in patients with diabetic peripheral neuropathy carrying the 677T allele and low folic acid levels. In conclusion, hyperhomocysteinemia is an independent risk factor for diabetic neuropathy in Chinese patients with diabetes. The C677T polymorphism in methylenetetrahydrofolate reductase and low folic acid levels may be risk factors for diabetic peripheral neuropathy in Chinese patients with diabetes. PMID:25538764

  7. Is the C677T polymorphism in methylenetetrahydrofolate reductase gene or plasma homocysteine a risk factor for diabetic peripheral neuropathy in Chinese individuals?

    PubMed

    Wang, Hongli; Fan, Dongsheng; Hong, Tianpei

    2012-10-25

    The present study enrolled 251 diabetic patients, including 101 with neuropathy and 150 without neuropathy. Of the 150 patients, 100 had no complications, such as retinopathy, nephropathy, or neuropathy. Polymerase chain reaction-restriction fragment length polymorphism analysis was used to identify methylenetetrahydrofolate reductase gene variants. Plasma homocysteine levels were also measured. Homocysteine levels and the frequency of hyperhomocysteinemia were significantly higher in patients with diabetic peripheral neuropathy compared with diabetic patients without neuropathy (P < 0.05). In logistic regression analysis with neuropathy as the dependent variable, the frequency of C677T in methylenetetrahydrofolate reductase was significantly higher in patients with diabetic peripheral neuropathy compared with patients without diabetic complications. Homocysteine levels were significantly higher in patients with diabetic peripheral neuropathy carrying the 677T allele and low folic acid levels. In conclusion, hyperhomocysteinemia is an independent risk factor for diabetic neuropathy in Chinese patients with diabetes. The C677T polymorphism in methylenetetrahydrofolate reductase and low folic acid levels may be risk factors for diabetic peripheral neuropathy in Chinese patients with diabetes.

  8. Methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism and diabetic nephropathy susceptibility in patients with type 2 diabetes mellitus.

    PubMed

    Zhou, Tian-Biao; Drummen, Gregor P C; Jiang, Zong-Pei; Li, Hong-Yan

    2015-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is a crucial enzyme that regulates nucleotide synthesis and DNA methylation. The MTHFR C677T gene polymorphism (rs1801133), a C → T transition at nucleotide 677 in exon 4, is a common gene variant of MTHFR and has been implicated in diabetic nephropathy, albeit with inconsistent results. Here, we performed a meta-analysis to assess the common effect size of this polymorphism on DN susceptibility. Case-control studies on the association of the MTHFR C677T gene polymorphism with DN risk were retrieved from databases up to August 1, 2013, and eligible studies were recruited into the meta-analysis and further analyzed. Of 132 studies, 33 were identified as suitable for this analysis. The results showed that T allele and TT genotype were distinctly associated with DN susceptibility in the overall population and Asians, and might be a risk factor in Caucasians and Africans (T allele: Overall population: p < 0.00001, Asians: p = 0.0002, Caucasians: p = 0.02, Africans: p < 0.00001; TT genotype: Overall population: p < 0.00001, Asians: p = 0.0003, Caucasians: p = 0.008, Africans: p = 0.0003). Furthermore, the analysis suggested that the CC genotype might play a protective role against DN onset in patients with type 2 diabetes for the overall population, Asians, Caucasian and Africans. However, due to the limited sample size in the African population, these results should be interpreted with care. In conclusion, the MTHFR C677T T allele or TT genotype might be a significant genetic molecular marker to determine the risk of DN in patients with type 2 diabetes and help to develop suitable disease prevention and management strategies.

  9. Methylenetetrahydrofolate reductase C677T polymorphism is associated with increased risk of coronary artery disease in young South African Indians.

    PubMed

    Ramkaran, Prithiksha; Phulukdaree, Alisa; Khan, Sajidah; Moodley, Devapregasan; Chuturgoon, Anil A

    2015-10-15

    Methylenetetrahydrofolate reductase (MTHFR) reduces 5',10'-methylenetetrahydrofolate to 5'-methyltetrahydrofolate, and is involved in remethylation of homocysteine to methionine, two important reactions involved in folate metabolism and methylation pathways. The common MTHFR C677T single nucleotide polymorphism (SNP) (rs1801133) has been associated with raised levels of homocysteine, a well known risk factor for coronary artery disease (CAD). CAD is a major cause of mortality worldwide. The age of onset of this chronic disorder is on the decline, particularly in the Indian population. Indians in South Africa (SA) have a higher prevalence of premature CAD compared to Black South Africans. The MTHFR C677T SNP has not been investigated in the SA Indian population. The present study therefore investigated the MTHFR C677T SNP in young SA Indian males with CAD compared to young Indian and Black male controls. A total of 290 subjects were recruited into this study which included 106 CAD patients (diagnosed on angiography, mean age 37.5, range 24-45 years), 100 Indian male controls (mean age 37.5, range 28-45 years), and 84 Black male controls (mean age 36.4, range 25-45). Polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) was used to genotype CAD patients and healthy controls. Data for clinical markers were obtained from pathology reports. There was a significant association between the 677 MTHFR variant (T) allele and CAD patients compared to the healthy Indian controls (p=0.0353, OR=2.105 95% CI 1.077-4.114). Indian controls presented with a higher frequency of the variant allele compared to Black controls (7% vs. 2% respectively, p=0.0515 OR=3.086 95% CI 0.9958-9.564). The MTHFR C677T SNP did not influence levels of total cholesterol, LDL, HDL, triglycerides, fasting glucose, fasting insulin, HbA1c or hsCRP. The higher frequency of the MTHFR 677 variant allele in South African Indians may be a contributing factor to the higher

  10. Role of 677C→T polymorphism a single substitution in methylenetetrahydrofolate reductase (MTHFR) gene in North Indian infertile men.

    PubMed

    Naqvi, Hena; Hussain, Syed Rizwan; Ahmad, Mohammad Kaleem; Mahdi, Farzana; Jaiswar, Shyam Pyari; Shankhwar, Satya Narayain; Mahdi, Abbas Ali

    2014-02-01

    Failure or severe difficulty in conceiving a child is surprisingly common, worldwide problem. Half of these cases are due to male factors with defects in sperm (1 in 15 men) being the single most common cause. Also about 60-75 % of male infertility cases are idiopathic, since the molecular mechanisms underlying the defects remain unknown. DNA methylation is crucial for spermatogenesis and high methylenetetrahydrofolate reductase (MTHFR) activity in adult testis than other organs in mouse, signifies its critical role in spermatogenesis. According to recent findings there is a correlation of epigenetic regulation of several imprinted genes with disturbed spermatogenesis and fertility. Consequently any change in the MTHFR gene sequence can modify the spermatogenesis including transmission of infertility to the carriers. The aim of the study is to analyze the distribution of the single nucleotide polymorphism C677T in the MTHFR gene in 637 North Indian infertile patients and 364 fertile North Indian men as controls by using PCR-RFLP technique and Chi Square test for statistical analysis. The average MTHFR 677CC, 677CT, 677TT genotype frequencies of total infertile men were 70.17, 24.17, 5.65 % in infertile men and 75.27, 21.7, 2.74 % in controls, respectively. The average frequency of the MTHFR 677T allele was 17.73 % in infertile men as compared to 13.59 % in controls. The statistical difference was significant. Disease risk was found 2.27-folds increased in patients who were carrying T allele. We found an association of C677T polymorphism with male infertility and that it may be a genetic risk factor for male infertility in North Indian population.

  11. Polymorphisms in methylenetetrahydrofolate reductase gene and risk of non-Hodgkin lymphoma in a multi-ethnic population.

    PubMed

    Suthandiram, Sujatha; Gan, Gin Gin; Zain, Shamsul Mohd; Haerian, Batoul Sadat; Bee, Ping Chong; Lian, Lay Hoong; Chang, Kian Meng; Ong, Tee Chuan; Mohamed, Zahurin

    2014-05-01

    An imbalance in folate metabolism can adversely affect DNA synthesis and methylation systems which can lead to susceptibility to non-Hodgkin lymphoma (NHL). Whether single nucleotide polymorphisms (SNPs) and their haplotypes in the methylenetetrahydrofolate reductase (MTHFR) are associated with NHL, remain inconclusive. We investigated the association between MTHFR C677T and A1298C SNPs and NHL risk in a population which is made up of Malay, Chinese and Indian ethnic subgroups. A total of 372 NHL patients and 722 controls were genotyped using the Sequenom MassARRAY platform. Our results of the pooled subjects failed to demonstrate significant association between the MTHFR C677T and A1298C SNPs with NHL and its subtypes. The results were in agreement with the previous meta-analyses. In the Indian ethnic subgroup however, single locus analysis of MTHFR A1298C appears to confer risk to NHL (Odds ratio (OR) 1.91, 95% confidence interval (95% CI) 1.22-3.00, P=0.006). The risk is almost doubled in homozygous carrier of MTHFR 1298CC (OR 4.03, 95% CI 1.56-10.43, P=0.004). Haplotype analysis revealed higher frequency of CC in the Indian NHL patients compared with controls (OR 1.86, 95% CI 1.18-2.93, P=0.007). There is lack of evidence to suggest an association between MTHFR C677T and A1298C with the risk of NHL in the Malays and Chinese. In the Indians however, the MTHFR A1298C confers risk to NHL. This study suggests ethnicity modifies the relationship between polymorphisms in the folate-metabolizing gene and NHL.

  12. Methylenetetrahydrofolate reductase: biochemical characterization and medical significance.

    PubMed

    Trimmer, Elizabeth E

    2013-01-01

    Methylenetetrahydrofolate reductase (MTHFR) catalyzes the reduction of 5,10-methylenetetrahydofolate (CH2-H4folate) to 5-methyltetrahydrofolate (CH3-H4folate). The enzyme employs a noncovalently-bound flavin adenine dinucleotide (FAD), which accepts reducing equivalents from NAD(P)H and transfers them to CH2-H4folate. The reaction provides the sole source of CH3-H4folate, which is utilized by methionine synthase in the synthesis of methionine from homocysteine. MTHFR plays a key role in folate metabolism and in the homeostasis of homocysteine; mutations in the enzyme lead to hyperhomocyst(e)inemia. A common C677T polymorphism in MTHFR has been associated with an increased risk for the development of cardiovascular disease, Alzheimer's disease, and depression in adults, and of neural tube defects in the fetus. The mutation also confers protection for certain types of cancers. This review presents the current knowledge of the enzyme, its biochemical characterization, and medical significance.

  13. Association between the methylenetetrahydrofolate reductase c.677C>T polymorphism and bone mineral density: an updated meta-analysis.

    PubMed

    Li, Hong-Zhuo; Wang, Wei; Liu, Yi-Ling; He, Xiao-Feng

    2016-02-01

    Many studies have reported an association between the methylenetetrahydrofolate reductase (MTHFR) c.677C>T polymorphism and reduced bone mineral density (BMD), but results have been inconsistent. We, therefore, performed a meta-analysis to further explore this association. Twenty-one studies, comprising 33,045 subjects, analyzed the association of MTHFR c.677C>T with femoral neck BMD. Significant association with reduced BMD was observed in Caucasians (recessive model: WMD = -0.004 g/cm(2), 95 % CI -0.008 to -0.006), post-menopausal women (recessive model: WMD = -0.005 g/cm(2), 95 % CI -0.007 to -0.003), men (dominant model: WMD = -0.004 g/cm(2), 95 % CI -0.005 to -0.004; recessive model: WMD = -0.004 g/cm(2), 95 % CI -0.005 to -0.004; TT vs. CC: WMD = -0.006 g/cm(2), 95 % CI -0.006 to -0.006; CT vs. CC: WMD = -0.003 g/cm(2), 95 % CI -0.003 to -0.003), and cohort studies (recessive model: WMD = -0.003 g/cm(2), 95 % CI -0.006 to -0.001). Twenty-two studies, which included 32,271 subjects, analyzed the MTHFR c.677C>T association with lumbar spine BMD. Significant association with reduced BMD was observed in Caucasians, women, post-menopausal women, men, and cohort studies. Seven studies, comprising 6806 subjects, analyzed the MTHFR c.677C>T association with total hip BMD, but no significant association was observed in any population. Nine studies involving 5591 subjects analyzed the association with total body BMD. Significant association with reduced BMD was observed in overall and women subgroup analyses. In summary, this meta-analysis indicates that the MTHFR c.677C>T polymorphism is associated with reduced BMD in lumbar spine and femoral neck in Caucasians, post-menopausal women, and men, and with total body BMD in women. In addition, our results suggest that new studies examining the association between MTHFR c.677C>T polymorphism and BMD of lumbar spine and femoral neck in Asians is warranted, because I (2) > 75.0 % was observed.

  14. Associations between Methylenetetrahydrofolate Reductase (MTHFR) Polymorphisms and Non-Alcoholic Fatty Liver Disease (NAFLD) Risk: A Meta-Analysis

    PubMed Central

    Sun, Man-Yi; Zhang, Li; Shi, Song-Li; Lin, Jing-Na

    2016-01-01

    Background C677T and A1298C are the most common allelic variants of Methylenetetrahydrofolate Reductase (MTHFR) gene. The association between MTHFR polymorphisms and the occurrence of non-alcoholic fatty liver disease (NAFLD) remains controversial. This study was thus performed to examine whether MTHFR mutations are associated with the susceptibility to NAFLD. Methods A first meta-analysis on the association between the MTHFR polymorphisms and NAFLD risks was carried out via Review Manager 5.0 and Stata/SE 12.0 software. The on-line databases, such as PubMed, EMBASE, CENTRAL, WOS, Scopus and EBSCOhost (updated to April 1st, 2016), were searched for eligible case-control studies. The odd radio (OR), 95% confidence interval (CI) and P value were calculated through Mantel-Haenszel statistics under random- or fixed-effect model. Results Eight articles (785 cases and 1188 controls) contributed data to the current meta-analysis. For C677T, increased NAFLD risks were observed in case group under homozygote model (T/T vs C/C, OR = 1.49, 95% CI = 1.03~2.15, P = 0.04) and recessive model (T/T vs C/C+C/T, OR = 1.42, 95% CI = 1.07~1.88, P = 0.02), but not the other genetics models, compared with control group. For A1298C, significantly increased NAFLD risks were detected in allele model (C vs A, OR = 1.53, 95% CI = 1.13~2.07, P = 0.006), homozygote model (C/C vs A/A, OR = 2.81, 95% CI = 1.63~4.85, P = 0.0002), dominant model (A/C+C/C vs A/A, OR = 1.60, 95% CI = 1.06~2.41, P = 0.03) and recessive model (C/C vs A/A+A/C, OR = 2.08, 95% CI = 1.45~3.00, P<0.0001), but not heterozygote model. Conclusion T/T genotype of MTHFR C677T polymorphism and C/C genotype of MTHFR A1298C are more likely to be associated with the susceptibility to NAFLD. PMID:27128842

  15. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and age at onset of schizophrenia: no consistent evidence for an association in the Nordic population.

    PubMed

    Saetre, Peter; Grove, Jakob; Børglum, Anders D; Mors, Ole; Werge, Thomas; Andreassen, Ole A; Vares, Maria; Agartz, Ingrid; Terenius, Lars; Jönsson, Erik G

    2012-12-01

    Methylenetetrahydrofolate reductase (MTHFR) is an enzyme involved in metabolic pathways of importance for nucleotide synthesis and methylation of DNA, membranes, proteins and lipids. The MTHFR gene includes a common polymorphism (rs1801133 or C677T), which is associated with enzyme activity. The T-allele of the C677T polymorphism has been associated with earlier age at onset of schizophrenia in a Scandinavian population, although no association was found in replication attempts in other populations. Extending the study to five Nordic samples consisting of 2,198 patients with schizophrenia, including the original Scandinavian samples, there was no significant association between MTHFR C677T polymorphism and age at onset in schizophrenia. The present results do not suggest that the investigated MTHFR polymorphism has any significant influence on age at onset of schizophrenia in the Nordic population.

  16. Serum homocysteine, vitamin B12, folic acid levels and methylenetetrahydrofolate reductase (MTHFR) gene polymorphism in vitiligo.

    PubMed

    Yasar, Ali; Gunduz, Kamer; Onur, Ece; Calkan, Mehmet

    2012-01-01

    The aim of this study was to determine serum vitamin B12, folic acid and homocysteine (Hcy) levels as well as MTHFR (C677, A1298C) gene polymorphisms in patients with vitiligo, and to compare the results with healthy controls. Forty patients with vitiligo and 40 age and sex matched healthy subjects were studied. Serum vitamin B12 and folate levels were determined by enzyme-linked immunosorbent assay. Plasma Hcy levels and MTHFR polymorphisms were determined by chemiluminescence and real time PCR methods, respectively. Mean serum vitamin B12 and Hcy levels were not significantly different while folic acid levels were significantly lower in the control group. There was no significant relationship between disease activity and vitamin B12, folic acid and homocystein levels. No significant difference in C677T gene polymorphism was detected. Heterozygote A1298C gene polymorphism in the patient group was statistically higher than the control group. There was no significant relationship between MTHFR gene polymorphisms and vitamin B12, folic acid and homocysteine levels. In conclusion, vitamin B12, folate and Hcy levels are not altered in vitiligo and MTHFR gene mutations (C677T and A1298C) do not seem to create susceptibility for vitiligo.

  17. Association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphism with ischemic stroke in the Eastern Chinese Han population.

    PubMed

    Lv, Q-Q; Lu, J; Sun, H; Zhang, J-S

    2015-04-27

    The association between the MTHFR genetic polymorphism and ischemic stroke has been reported by a number of investigators. However, the results have been controversial and conflicting. The aim of this study was to explore the association between the MTHFR variants C677T and A1298C and the risk of ischemic stroke in an Eastern Chinese Han population. A total of 199 patients with ischemic stroke and 241 controls were recruited. Genotyping of the MTHFR C677T and A1298C polymorphisms was carried out using the Taqman 7900HT Sequence Detection System. The overall estimates (odds ratio: OR) for the allele (C) and genotype (AC+CC) of the A1298C polymorphism were 1.57 [95% confidence interval (CI) = 1.16-2.10], and 2.36 (95%CI = 1.39-4.00), respectively, establishing significant association of the MTHFR A1298C polymorphism with ischemic stroke. In contrast, there were no statistically significant differences compared to controls between MTHFR C677T polymorphic variants in the association ischemic stroke risk. Furthermore, haplotype-based analysis demonstrated that compared with the C-677-A-1298 haplotype, the C-677-C-1298 and T-677-C-1298 haplotypes showed significant increased risk of ischemic stroke (OR = 1.56; 95%CI = 1.07- 2.2; P = 0.02; OR = 1.76; 95%CI = 1.17-2.65; P < 0.01, respectively). We concluded that the A1298C polymorphism and the haplotypes C-677-C-1298 and T-677-C-1298 in MTHFR might modulate the risk of ischemic stroke in the Eastern Chinese Han population.

  18. Association of methylenetetrahydrofolate reductase gene 677C > T polymorphism and Down syndrome.

    PubMed

    Costa-Lima, Marcelo Aguiar; Amorim, Márcia Rodrigues; Orioli, Iêda Maria

    2013-03-01

    The association between Down syndrome (DS) and maternal polymorphisms in genes encoding folic acid metabolizing enzymes remains a controversial issue. A meta-analysis was performed to evaluate the association of maternal MTHFR 677C > T polymorphism and the risk of having a child with DS. Case-control studies were screened from major literature databases. Twenty articles from 13 countries worldwide, with a total of 2,101 DS and 2,702 control mothers, attended the inclusion criteria. We found a 50 % increase for the association of maternal homozygous TT genotype and DS in both fixed (OR = 1.51; 95 % CI 1.22-1.87) and random effects models (OR 1.54; 95 % 1.15-2.05). Similarly, a significant pooled OR was found for the heterozygote CT, with an OR 1.26; 95 % CI 1.10-1.43 (fixed effects model) and OR 1.28; 95 % 1.08-1.51 (random effects model). As ultra-violet B solar radiation highly depends on latitude, and can promote, in less pigmented skin, intravascular folate photolysis, we stratified the analysis by latitude region, defining as Tropical (between 23.5(°) S and 23.5(°) N), Sub-Tropical (between 23.5(°) and 40(°) N and S), and Northern (≥ 40(o) N). Significant association was only found for Sub-Tropical area, both using fixed and random effect models. In conclusion, MTHFR 677C > T polymorphism is a moderate risk factor for DS for some populations, and populations located in Sub-Tropical region seem to be at greater risk. Latitude, ethnicity, skin pigmentation, and red blood cell folate are important variables to be considered in future studies.

  19. Methylenetetrahydrofolate reductase gene polymorphisms and the risk of anencephaly in Mexico.

    PubMed

    Muñoz, Julia Blanco; Lacasaña, Marina; Cavazos, Ricardo García; Borja-Aburto, Victor Hugo; Galavíz-Hernández, Carlos; Garduño, Clemente Aguilar

    2007-06-01

    The precise etiology of neural tube defects (NTDs) is not known. There is some evidence that mutations in MTHFR gene provide susceptibility to NTDs in some populations; however, other studies have not found this association. One of the problems with previous studies is that they treat NTDs as a homogeneous group, when specific defects could have different etiologies. We conducted a case-control study specifically for anencephaly, based on the Mexican Epidemiological Surveillance System of Neural Tube Defects to evaluate its association with maternal MTHFR 677C > T and 1298A > C polymorphisms, in three states with high frequencies of NTDs: Puebla, Estado de México and Guerrero. We interviewed and collected blood samples from 118 case mothers and 112 control mothers. The questionnaire included information on their reproductive history, socioeconomic characteristics, prenatal care, tobacco and alcohol use, presence of chronic diseases, acute illnesses and fever, consumption of multivitamins and drugs during the periconceptional period. After adjusting for potential confounders, the risk from the mutated homozygous mothers (677TT genotype) was significantly higher than that from mothers with 677CC genotype (OR 3.16, 95% CI 1.29-7.73); in the case of the heterozygous mothers, an increased risk of anencephaly was observed, even though this was not statistically significant (OR 1.81 95% CI 0.78-4.25). The association found between maternal 677TT genotype and anencephaly and the elevated presence of the 677T allele among Mexican women of fertile age urges intensifying folic acid supplementation which has proved to modify this genetic risk in other populations.

  20. The methylenetetrahydrofolate reductase (MTHFR) 677 C>T polymorphism increases the risk of developing chronic myeloid leukemia-a case-control study.

    PubMed

    Bănescu, Claudia; Iancu, Mihaela; Trifa, Adrian P; Macarie, Ioan; Dima, Delia; Dobreanu, Minodora

    2015-04-01

    The methylenetetrahydrofolate reductase (MTHFR) 677 C>T and 1298 A>C polymorphisms are associated with variations in folate levels, a phenomenon linked to the development of various malignancies. The aim of this study was to investigate the influence of the 677 C>T and 1298 A>C polymorphisms in the MTHFR gene on the risk of developing chronic myeloid leukemia (CML). Our study included 151 patients with CML and 305 controls. The MTHFR 677 C>T and 1298 A>C polymorphisms were investigated by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and allele-specific PCR techniques. The CT and TT genotypes of the MTHFR 677 C>T polymorphism were associated with an increased risk of developing CML (odds ratio (OR) = 1.556, 95% confidence interval (CI) = 1.017-2.381, p value = 0.041, and OR = 1.897, 95% CI = 1.046-3.44, p value = 0.035, respectively). No association was observed between the prognostic factors (blasts, basophils, additional chromosomal abnormalities, EUTOS score, Sokal and Hasford risk groups) and the MTHFR 677 C>T and 1298 A>C variant genotypes in CML patients. Our study shows that the MTHFR 677 C>T polymorphism is significantly associated with the risk of CML in Romanian patients.

  1. Methylenetetrahydrofolate reductase (MTHFR) 677C/T polymorphism is associated with antipsychotic-induced weight gain in first-episode schizophrenia.

    PubMed

    Srisawat, Umarat; Reynolds, Gavin P; Zhang, Zhi Jun; Zhang, Xiang Rong; Arranz, Belen; San, Luis; Dalton, Caroline F

    2014-03-01

    Genetic variants of the methylenetetrahydrofolate reductase (MTHFR) gene involved in homocysteine metabolism may be important predictors of antipsychotic drug-induced weight gain (AIWG). We tested whether two functional MTHFR polymorphisms are related to AIWG. Weight gain was studied in two cohorts of first-episode, initially drug-naive schizophrenia patients; Chinese Han (n = 182) and Spanish Caucasians (n = 72) receiving antipsychotics for 10 wk and 3 months respectively. Blood DNA was genotyped for 677C/T and 1298A/C MTHFR polymorphisms. Patients with the 677 CC genotype had a significantly greater increase in BMI compared to T-allele carriers in both Chinese (p = 0.012) and Spanish (p = 0.017) samples. The 677C/T MTHFR polymorphism showed an additive effect, but no significant interaction, with the -759C/T HTR2C polymorphism previously associated with AIWG. These results suggest that the 677C/T MTHFR polymorphism might, along with the -759C/T HTR2C polymorphism and other genetic factors, provide a useful marker for the important and limiting side effect of AIWG.

  2. Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and susceptibility to diabetic nephropathy in Chinese type 2 diabetic patients: a meta-analysis.

    PubMed

    Chang, Wei-wei; Zhang, Liu; Yao, Ying-shui; Su, Hong; Jin, Yue-long; Chen, Yan

    2013-08-01

    The association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and diabetic nephropathy (DN) or diabetes mellitus (DM) risk has been widely reported, but the results are still debatable. To investigate the role of MTHFR C677T polymorphism on DM or DN, 13 separate studies in the Chinese population on the relation between MTHFR C677T polymorphism and DM or DN were analyzed by a meta-analysis. Five genetic models were used to estimate the association between MTHFR C677T polymorphism and the risk of DM or DN. Overall, our meta-analysis for DN versus healthy controls produced significant results for all genetic contrasts except for the co-dominant model (allele contrast: OR = 2.24, 95%CI: 1.88-2.65, p < 0.00001, Pheterogeneity = 0.49). However, the meta-analysis for DM versus healthy controls produced non-significant results for all contrasts (allele contrast: OR = 1.12, 95%CI: 0.92-1.35, p = 0.25, Pheterogeneity = 0.07). In addition, the meta-analysis for DM versus DN produced significant results for all contrasts (allele contrast: OR = 1.88, 95%CI: 1.65-2.15, p < 0.00001, Pheterogeneity = 0.83). The current meta-analysis suggested that MTHFR C677T polymorphism might influence DN risk, but not for DM in the Chinese population.

  3. C677T polymorphism of the methylenetetrahydrofolate reductase gene does not affect folic acid, vitamin B12, and homocysteine serum levels in Turkish children with neural tube defects.

    PubMed

    Erdogan, M O; Yildiz, S H; Solak, M; Eser, O; Cosar, E; Eser, B; Koken, R; Buyukbas, S

    2010-06-22

    Association between neural tube defects (NTDs) and C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene was suspected, because the MTHFR gene codes for a key enzyme in folate metabolism. Its deficiency usually leads to significant reductions in plasma concentrations of folate, vitamin B(12) and methionine, whereas homocysteine levels are increased. We examined folate, vitamin B(12) and homocysteine serum concentrations and polymorphism of the C677T MTHFR gene in Turkish children with neural tube defects. Thirty-three children with NTDs, 26 mothers and 48 healthy individuals were studied. C677T MTHFR polymorphism was determined by melting curve analyses (LightCycler). The levels of folate, vitamin B(12) and homocysteine serum concentrations in NTDs were evaluated and compared, along with information concerning alleles of the MTHFR gene. C677T allele frequencies in NTD children and their mothers were similar to those found in controls. Serum folate and vitamin B(12) concentrations were significantly higher in NTD children than that of controls. Serum homocysteine concentrations were not significantly higher in NTD children and mothers. We concluded that C677T MTHFR gene polymorphism does not affect folic acid, vitamin B(12) and homocysteine metabolism in Turkish children with NTDs. C677T polymorphism of the MTHFR gene cannot be regarded as a major risk factor for NTDs in Turkish children.

  4. [Clinical course of acute coronary syndrome in dependence on containing of homozystein and С677Т methylenetetrahydrofolate reductase gene polymorphism].

    PubMed

    Pristupa, L N; Grek, A V; Ataman, Iu A; Orlovskiy, A V; Opolonska, N A

    2015-01-01

    Nowadays to a numerous factors of IHD development risks hyperhomocysteinemia (HHc), C-reactive protein, fibrogen, as well as genetic disorders are relating. With development of IHD and its complications associated methylentetrahudrofolate reductase gene mutation of С677Т polymorphism. The purpose of the investigation was studying the connection between acute coronary syndrome severity (ACS) in dependence on plasma homocysteine containing and genotype by С677Т polymorphism MTHFR gene. Examined: 161 patients with ACS and 87 almost healthy people. Identification of 4th exon allelic polymorphism MTHFR С677Т gene (rs1801133) was conducted with method of polymerase chain reaction, the investigation of homocysteine containing with immunoenzymated method. The statistic analyze was performed with using of SPSS - 17 programme. According to results of study patients with ACS of homozygote by minor allele T С677Т MTHFR gene polymorphism by main allele C and heterozygote were associated with high homocysteine containing in plasma. While frequencies of T/T genotype was reliably higher in patients with ACS with segment ST elevation and complicated course compare with patients with ACS with segment ST elevation and non-complicated course and ACS without climbs of segment ST. Also, statistically reliable difference in genotypes distribution by C677T MTHFR gene polymorphism in dependence on homocysteine plasma level and clinical course of ACS severity were established.

  5. Genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene Ala222Val and susceptibility to ovary cancer: a systematic review and meta-analysis.

    PubMed

    Pan, Xinwei; Lu, Yan; Long, Ying; Yao, Desheng

    2014-03-01

    Many studies have reported the role of methylenetetrahydrofolate reductase (MTHFR) gene Ala222Val polymorphism with ovary cancer risk, but the results remained controversial. To derive a more precise estimation of the relationship, a meta-analysis was performed. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between MTHFR Ala222Val polymorphism and ovary cancer risk. A total of 8 studies including 3,723 cases and 4,001 controls were also involved in this meta-analysis. When all the eligible studies were pooled into this meta-analysis, no significant association between ovary cancer risk and MTHFR Ala222Val polymorphism was found in all genetic models [codominant model: OR = 0.980, 95% CI = 0.756-1.270, P h = 0.088, P = 0.877; dominant model: OR = 1.022, 95% CI = 0.864-1.208, P h = 0.033, P = 0.803; recessive model: OR = 1.050, 95% CI = 0.803-1.373, P h = 0.032, P = 0.723; allele comparison model: OR = 1.028, 95% CI = 0.898-1.178, P h = 0.012, P = 0.685]. In the stratified analysis by ethnicity, no evidence of any associations of this polymorphism with ovary cancer was found in the Caucasian populations. Our meta-analysis supports that the MTHFR Ala222Val polymorphism is not contributed to the risk of ovary cancer from currently available evidence.

  6. Ethnic variation of the C677T and A1298C polymorphisms in the methylenetetrahydrofolate-reductase (MTHFR) gene in southwestern Mexico.

    PubMed

    Antonio-Véjar, V; Del Moral-Hernández, O; Alarcón-Romero, L C; Flores-Alfaro, E; Leyva-Vázquez, M A; Hernández-Sotelo, D; Illades-Aguiar, B

    2014-09-29

    In this study, we examined the distribution of genotype and allele frequencies of the C677T and A1298C polymorphisms in the methylenetetrahydrofolate-reductase gene (MTHFR) in two ethnic groups in the State of Guerrero, Mexico, which were compared with those of the Mestizo population of the region. A comparative study was conducted on 455 women from two ethnic groups and a group of Mestizo women of the State of Guerrero, Mexico: 135 Nahuas, 124 Mixtecas, and 196 Mestizas. Genotyping of both polymorphisms were performed by using polymerase chain reaction-restriction fragment length polymorphism methods. We found that the 677TT genotype was more frequent in Nahua and Mixteca women compared to Mestiza women (P = 0.008), and the most prevalent genotype in both ethnic groups was the 1298AA genotype (P < 0.001). We also compared the 677T allele frequency obtained from the groups studied with the frequencies reported in other ethnic groups of Mexico (Huichol, Tarahumara, and Purepecha). There were significant differences between the three ethnic groups compared to Nahuas (Huicholes, P = 0.004; Tarahumaras, P < 0.001; Purepechas, P = 0.042). Our results indicated significant differences in the frequencies of the C677T and A1298C polymorphisms between the two ethnic groups and the Mestizo population of the State of Guerrero. In addition, we found strong differences with other ethnic groups in Mexico. These results could be useful for future studies investigating diseases related to folate metabolism, and could help the government to design specific nutrition programs for different ethnic groups.

  7. Analysis of genetic polymorphisms of brain-derived neurotrophic factor and methylenetetrahydrofolate reductase in depressed patients in a Slovak (Caucasian) population.

    PubMed

    Evinova, Andrea; Babusikova, Eva; Straka, Stanislav; Ondrejka, Igor; Lehotsky, Jan

    2012-12-01

    Major depressive disorder (MDD) is a complex neuropsychiatric disorder where both gene-gene and gene-environment interactions play an important role, but the clues are still not fully understood. One carbon metabolism in the CNS plays a critical role in the synthesis and release of neurotransmitters which are relevant to depressive disorder. We studied genetic polymorphisms of the brain derived neurotrophic factor (BDNF) and the methylenetetrahydrofolate reductase (MTHFR) in association with major depressive disorder. We genotyped the BDNF G196A, the MTHFR C677T, and A1298C polymorphisms in 134 patients diagnosed with major depression and 143 control subjects in Slovak (Caucasian) cohort of patients and probands. We found no significant association of either the BDNF G196A or MTHFR C677T polymorphisms with major depressive disorder neither in female nor male group of patients. However, the MTHFR A1298C genotype distribution was 36.6% (for AA genotype), 48.5% (AC) and 14.9% (CC) for the depressed patients, and 48.9% (AA), 42.7% (AC) and 8.4% (CC), respectively, for the control subjects. Patients with MDD had a higher prevalence of the CC genotype (OR = 2.38; 95% CI = 1.07-5.32; p = 0.032) and the AC + CC genotype (OR = 1.67; 95% CI = 1.03-2.69; p = 0.037) in comparison with the control subjects. This study shows that CC genotype of the MTHFR A1298C is associated with higher risk of MDD in Slovak population.

  8. Pregnancy-associated osteoporosis with a heterozygous deactivating LDL receptor-related protein 5 (LRP5) mutation and a homozygous methylenetetrahydrofolate reductase (MTHFR) polymorphism.

    PubMed

    Cook, Fiona J; Mumm, Steven; Whyte, Michael P; Wenkert, Deborah

    2014-04-01

    Pregnancy-associated osteoporosis (PAO) is a rare, idiopathic disorder that usually presents with vertebral compression fractures (VCFs) within 6 months of a first pregnancy and delivery. Spontaneous improvement is typical. There is no known genetic basis for PAO. A 26-year-old primagravida with a neonatal history of unilateral blindness attributable to hyperplastic primary vitreous sustained postpartum VCFs consistent with PAO. Her low bone mineral density (BMD) seemed to respond to vitamin D and calcium therapy, with no fractures after her next successful pregnancy. Investigation of subsequent fetal losses revealed homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism associated both with fetal loss and with osteoporosis (OP). Because her neonatal unilateral blindness and OP were suggestive of loss-of-function mutation(s) in the gene that encodes LDL receptor-related protein 5 (LRP5), LRP5 exon and splice site sequencing was also performed. This revealed a unique heterozygous 12-bp deletion in exon 21 (c.4454_4465del, p.1485_1488del SSSS) in the patient, her mother and sons, but not her father or brother. Her mother had a normal BMD, no history of fractures, PAO, ophthalmopathy, or fetal loss. Her two sons had no ophthalmopathy and no skeletal issues. Her osteoporotic father (with a family history of blindness) and brother had low BMDs first documented at ages ∼40 and 32 years, respectively. Serum biochemical and bone turnover studies were unremarkable in all subjects. We postulate that our patient's heterozygous LRP5 mutation together with her homozygous MTHFR polymorphism likely predisposed her to low peak BMD. However, OP did not cosegregate in her family with the LRP5 mutation, the homozygous MTHFR polymorphism, or even the combination of the two, implicating additional genetic or nongenetic factors in her PAO. Nevertheless, exploration for potential genetic contributions to PAO may explain part of the pathogenesis of this

  9. Methylenetetrahydrofolate Reductase C677T Polymorphism and Type 2 Diabetes Mellitus in Chinese Population: A Meta-Analysis of 29 Case-Control Studies

    PubMed Central

    Zhu, Bo; Wu, Xiaomei; Zhi, Xueyuan; Liu, Lei; Zheng, Quanmei; Sun, Guifan

    2014-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR), a key enzyme in folate metabolism, had significant effects on the homocysteine levels. The common functional MTHFR C677T polymorphism had been extensively researched. Several studies had evaluated the relationship between MTHFR C677T polymorphism and type 2 diabetes mellitus (T2DM), but the results were still controversial in the Chinese Han population. This meta-analysis was conducted to evaluate the relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. Methods We searched the relevant studies in multiple electronic databases, which published up to December 2013. We reviewed and extracted data from all the included studies on the relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. The odds ratios (ORs) and their 95% confidence intervals (95%CIs) were used to evaluate the relationship. Fixed-effects and random-effects meta-analysis were used to pool ORs by the heterogeneity. Publication bias and sensitivity analysis were also examined. Results 29 studies were finally included in our meta-analysis, which contained 4656 individuals with T2DM and 2127 healthy controls. There was a significant relationship between MTHFR C677T polymorphism and T2DM under dominant (OR: 1.70, 95% CI: 1.42–2.02), recessive (OR: 1.48, 95% CI: 1.21–1.80), homozygous (OR: 1.89, 95% CI: 1.47–2.42), heterozygous (OR: 1.58, 95% CI: 1.33–1.87), and additive (OR: 1.46, 95% CI: 1.28–1.68) genetic model in a random-effects model. Subgroup analysis also reached similar results. Sensitivity analysis indicated that the overall result were dependable. Conclusions There was a significant relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. The results of our meta-analysis suggested that MTHFR 677T allele might be a risk genetic factor of T2DM in the Chinese Han population. PMID:25047451

  10. Impact of methylenetetrahydrofolate reductase polymorphisms and folate intake on the risk of gastric cancer and their association with Helicobacter pylori infection and tumor site.

    PubMed

    Chen, J; Yuan, L; Duan, Y Q; Jiang, J Q; Zhang, R; Huang, Z J; Xiao, X R

    2014-01-24

    Folic acid and methylenetetrahydrofolate reductase (MTHFR) may both affect the development of human cancer. We conducted a population-based case-control study in a Chinese population to investigate the potential role of folate intake and MTHFR gene polymorphisms in gastric cancer, and their interaction with infection by Helicobacter pylori and tumor location. A total of 767 patients with newly diagnosed gastric cancer and 775 controls were selected for this study. Genotyping of MTHFR C677T and A1298C was conducted by TaqMan assays using the ABI Prism 7911HT Sequence Detection System, and information on folate intake was collected by questionnaire. Compared with the CC genotype of MTHFR C677T, the TT genotype was significantly associated with a decreased risk of gastric cancer when the analysis was adjusted for other potential risk factors. We found a marginal significantly decreased risk of gastric cancer for individuals carrying the T allele [adjusted odds ratio (OR) = 0.83; 95% confidence interval (CI) = 0.65-1.01]. We detected an inverse relationship between folate intake and risk of gastric cancer, and the adjusted ORs (95%CI) for moderate and high folate intake were 0.97 (0.74-1.25) and 0.64 (0.49-0.87), respectively. Moreover, H. pylori infection, folate intake, and location of the tumor showed a significant interaction with the MTHFR C677T polymorphism. Our study suggests a protective role of MTHFR 677TT and high folate intake against gastric cancer, and the effect of the MTHFR C677T genotype may differ by H. pylori infection, folate consumption, and tumor site.

  11. B-vitamins, methylenetetrahydrofolate reductase (MTHFR) and hypertension.

    PubMed

    Ward, Mary; Wilson, Carol P; Strain, J J; Horigan, Geraldine; Scott, John M; McNulty, Helene

    2011-07-01

    Hypertension is a leading risk factor for cardiovascular disease (CVD) and stroke. A common polymorphism in the gene encoding the enzyme methylenetetrahydrofolate reductase (MTHFR), previously identified as the main genetic determinant of elevated homocysteine concentration and also recognized as a risk factor for CVD, appears to be independently associated with hypertension. The B-vitamin riboflavin is required as a cofactor by MTHFR and recent evidence suggests it may have a role in modulating blood pressure, specifically in those with the homozygous mutant MTHFR 677 TT genotype. If studies confirm that this genetic predisposition to hypertension is correctable by low-dose riboflavin, the findings could have important implications for the management of hypertension given that the frequency of this polymorphism ranges from 3 to 32 % worldwide.

  12. The effects of polymorphisms in methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), and methionine synthase reductase (MTRR) on the risk of cervical intraepithelial neoplasia and cervical cancer in Korean women.

    PubMed

    Tong, Seo-Yun; Lee, Jong-Min; Song, Eun-Seop; Lee, Kwang-Beom; Kim, Mi-Kyung; Yun, Young Mi; Lee, Jae-Kwan; Son, Sung-Kyong; Lee, Jung-Pil; Kim, Jae-Hoon; Hur, Soo-Young; Kwon, Yong-Il

    2010-01-01

    The purpose of the study was to investigate the association between cervical cancer risk and single-nucleotide polymorphisms (SNPs) in three one-carbon metabolism genes, methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), and methionine synthase reductase (MTRR) in Korean women. Twelve SNPs were identified in MTHFR, MTR, and MTRR in the 927 case-control samples, which included 165 cervical intraepithelial neoplasia 1 (CIN1), 167 cervical intraepithelial neoplasia 2 and 3 (CIN2/3), 155 cervical cancer patients, and 440 normal controls. The frequencies of the genotypes and haplotypes were assessed in the controls, CINs, and cervical cancers. Individual carriers of the variant allele C of MTHFR A1298C (rs1801131) had a 0.64-fold [95% confidence interval (CI): 0.42-0.98] decreased risk for CIN2/3 compared with common homozygotes. However, no significant association was found between most other variants and cervical cancer risk. The results also identified an increased CIN1 risk in carriers with at least one copy of haplotype 3 in the MTHFR gene (odds ratio, 1.88; 95% CI: 1.03-3.42). In conclusion, there was no significant association between most SNPs in MTHFR, MTR, or MTRR and the risk of CIN and cervical cancer in Korean women. In addition, there was no significant association of MTHFR haplotypes with risk of CIN2/3 and cervical cancer.

  13. Genetic susceptibility of methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C, and G1793A polymorphisms with risk for bladder transitional cell carcinoma in men.

    PubMed

    Safarinejad, Mohammad Reza; Shafiei, Nayyer; Safarinejad, Shiva

    2011-12-01

    We performed a case-control study of 158 bladder transitional cell carcinoma (TCC) cases and 316 controls to investigate the association between methylenetetrahydrofolate reductase (MTHFR) C677T, A1298G, and G1793A polymorphisms and bladder cancer susceptibility by polymerase chain reaction restriction fragment length polymorphism (PCR-RLFP) technique. The controls were frequency-matched to the cases by age (± 5 years), ethnicity, and smoking status. We also measured serum levels of total homocysteine (tHcy), folate, and vitamin B12. It was found that the 1298AC (odds ratio, OR = 3.74; 95% confidence interval, CI = 2.34-5.47; P = 0.001) and 1298CC (OR = 3.46, 95% CI = 2.37-5.52; P = 0.001) genotypes of MTHFR A1298C were significantly associated with increased risk of bladder TCC. The MTHFR C677T and G1793A polymorphisms were not associated with bladder TCC. After stratification for grade and stage, we observed that the 677TT (OR = 4.47, 95% CI = 2.74-6.72; P = 0.001) and MTHFR 1298CC (OR = 4.78, 95% CI = 2.82-6.89; P = 0.001) genotypes of MTHFR were associated with increased risk of muscle-invasive bladder TCC. We also found that the MTHFR 677CT+1298AA genotypes were associated with an approximately 70% reduction in risk of bladder cancer (OR = 0.31; 95% CI = 0.15-0.68) compared to the combined referent genotype. There were 8 haplotypes and 16 haplotype genotypes based on these three variants. When we used the haplotypes and assumed that the 677T, 1298C, and 1793G alleles were risk alleles, the adjusted odds ratios increased as the number of risk alleles increased: 1.00 for 0-1 variant, 1.88 (1.4-2.7) for any two risk alleles and 2.07 (1.6-2.8) for any three risk alleles. Serum tHcy levels were significantly higher in carriers of the 677T, 1298C, and 1793G alleles compared to noncarriers (all P < 0.01). There was no significant correlation between serum levels of tHcy and folate and bladder cancer risk. Further studies in larger samples size and different

  14. Association of methylenetetrahydrofolate reductase C677T polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

    PubMed Central

    2010-01-01

    Background The association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphism and serum lipid profiles is still controversial in diverse ethnics. Bai Ku Yao is an isolated subgroup of the Yao minority in China. The aim of the present study was to eveluate the association of MTHFR C677T polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations. Methods A total of 780 subjects of Bai Ku Yao and 686 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of the MTHFR C677T was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. Results The levels of serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) AI and ApoB were lower in Bai Ku Yao than in Han (P < 0.05-0.001). The frequency of C and T alleles was 77.4% and 22.6% in Bai Ku Yao, and 60.9% and 39.1% in Han (P < 0.001); respectively. The frequency of CC, CT and TT genotypes was 58.7%, 37.3% and 4.0% in Bai Ku Yao, and 32.6%, 56.4% and 11.0% in Han (P < 0.001); respectively. The levels of TC and LDL-C in both ethnic groups were significant differences among the three genotypes (P < 0.05-0.01). The T allele carriers had higher serum TC and LDL-C levels than the T allele noncarriers. The levels of ApoB in Han were significant differences among the three genotypes (P < 0.05). The T allele carriers had higher serum ApoB levels as compared with the T allele noncarriers. The levels of TC, TG and LDL-C in Bai Ku Yao were correlated with genotypes (P < 0.05-0.001), whereas the levels of LDL-C in Han were associated with genotypes (P < 0.001). Serum lipid parameters were also correlated with sex, age, body mass index, alcohol consumption, cigarette smoking, and blood pressure in the both ethnic

  15. Impact of Genetic Polymorphism of methylenetetrahydrofolate reductase C677T on Development of Hyperhomocysteinemia and Related Oxidative Changes in Egyptian β-Thalassemia Major Patients

    PubMed Central

    Abd-Elmawla, Mai A.; Rizk, Sherine M.; Youssry, Ilham; Shaheen, Amira A.

    2016-01-01

    Background β-thalasemia major (β-TM) patients often suffer from various vascular complications together with increased oxidative stress. Hyperhomocysteinemia (Hhcy) has been defined as a risk factor for these complications. Genetic polymorphism of methylenetetrahydrofolate reductase (MTHFR) C677T has been shown to cause Hhcy particularly in individuals with low B-vitamins. However, the status of homocysteine (hcy) in β-TM has not yet been adequately defined. Aim To evaluate the genetic polymorphism of MTHFR C677T among β-TM patients and its prospective contribution to Hhcy and related oxidative changes. Subjects and Methods Genotyping for MTHFR C677T was done by PCR-RFLP technique. Plasma hcy, vitamin B12, folate, malondialdehyde (MDA), total antioxidant capacity (TAC), oxidized low density lipoprotein (oxLDL), total nitric oxide (NOx) and lipid profile were determined in 66 β-TM patients and 66 control subjects of matched age and sex. Results The prevalence of MTHFR 677TT genotype was significant among β-TM patients (12%) compared to (3%) controls (OR = 4.9, 95%CI:1.2–24.2,P = 0.03). A strong association between Hhcy and MTHFR TT genotype was observed (OR = 7.7, 95%CI:2.8–20.9) where all β-TM patients with TT genotype were hyperhomocystienemic (≥ 15 μmol/l) and having sub-optimal folate level than those with CT or CC genotypes. Hyperhomocystienemic patients have suffered from increased oxidative stress characterized by significant increase in plasma MDA and oxLDL, and a significant reduction of plasma TAC and total NOx. Lipid profile of those patients was severely affected indicated by reduction in HDL and HDL/LDL and elevation in atherogenic index as compared with CC genotype. Other measured parameters were not significantly different among β-TM patients with different MTHFR genotypes. Conclusion This study suggests that Egyptian β-TM patients with MTHFR 677TT genotype could be at increasing risk of developing Hhcy particularly with folate

  16. Genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene and susceptibility to depression in Asian population: a systematic meta-analysis.

    PubMed

    Rai, V

    2014-01-01

    Genetic association studies on MTHFR C677 T polymorphism and depression have been repeatedly performed over the last two decades and results are generally inconsistent. The aim of the present study was to assess the risk of MTHFR C677T polymorphism for depression in Asian population. The author performed a meta-analysis and pooled data from individual case-control studies that examined the association between C677T polymorphism and depression (meta-analysis: 13 studies, 1,120 cases and 1,688 controls).The pooled Odd Ratios (OR) were estimated by both fixed effects and random effects models. Overall, there was an association between MTHFR C677T polymorphism and increased risk of depression under five genetic models (OR T vs. C=1.44, 95% CI= 1.56-1.78, P=0.001; OR TT vs. CC= 1.78, 95% CI 1.17– 2.69, P=0.006; OR CT vs CC=1.102, 95% CI=0.91-1.32,P=0.31; OR TT vs. CT+CC=1.73, 95% CI= 0.87-3.41, P=0.11; OR TT+CT vs. CC=1.26, 95% CI=0.96-1.64, P=0.08). Sensitivity analysis suggested exclusion of any single study did not alter the overall pooled Ors. In conclusion results of present meta-analysis supports that there is a significant association between MTHFR C677T polymorphism and depression risk, and MTHFR 677T allele contributes to increased risk of depression in Asian individuals.

  17. Comparison of the frequency of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in depressed versus nondepressed patients.

    PubMed

    Lizer, Mitsi H; Bogdan, Renee L; Kidd, Robert S

    2011-11-01

    Numerous studies have found an association between low serum folate levels and incidence of depression. Folic acid supplementation has been successfully used as an adjunct to treat depression in these patients. However, some individuals have a genetic deficiency in the methylene tetrahydrofolate reductase (MTHFR) gene that limits conversion of folic acid to its biologically active form, L-methylfolate. Several studies have identified a higher frequency of genetic variations in the MTHFR gene in depressed patients than in nondepressed controls. This study evaluated the frequency of the most common genetic variation MTHFR C667T in a group of depressed U.S. Caucasians and compared results with those of a control group of nondepressed U.S. Caucasians. Subjects were recruited from a psychiatric practice, an ambulatory care clinic, and the community. Informed consent and a cheek swab sample were obtained from each subject for analysis using real-time polymerase chain reaction (PCR). Allele and genotype frequencies were compared using Pearson X2 analysis. Complete data were obtained for 156 subjects. No significant differences were found in frequency of the MTHFR C667T T allele (0.415 vs 0.365; p=0.408) or the MTHFR C667T TT genotype (20.7% vs 17.6%; p=0.619) between the depressed and non-depressed controls, respectively. Therefore, use of L-methylfolate without an additional indication of need does not appear to be warranted in this group of U.S. Caucasians. Some patients may benefit from L-methylfolate, but an evidence-based approach, such as MTHFR genotyping, should be used to identify these specific patients. Additional research is also needed to confirm the benefit of L-methylfolate in specific patient populations (e.g., MTHFR TT genotype).

  18. [Investigation of detoxification polymorphisms genes, methylenetetrahydrofolate-reductase (MTHFR) and P53 in the radiosensitive human cells].

    PubMed

    Shagirova, Zh M; Ushenkova, L N; Mikhaĭlov, V F; Kurbatova, L A; Kuz'mina, N S; Semiachkina, A N; Vasil'eva, I M; Mazurik, V K; Zasukhina, G D

    2010-01-01

    The genes of detoxication, MTHFR and p53 were studied in Down' and Ehlers-Danlos syndrome cells. The frequency GSTM1(0/0) genotype in Down syndrome patients was in 1.5 times higher than in control cells (p < 0.069). Opposite the frequency GSTM1(0/0) genotype in Ehlers-Danlos syndrome was 23.3% 2 times lower than in control cells (p < 0.034). This indication was in 2 times lower in women cells than in men cells and in 3 times lower than in control cells (p < 0.026). The mutations of p53 gene (7th exon) were detected in 4 from 11 Down patients (36.7%; in 2 cases af women and men), in Ehlers-Danlos patients--in 5 cases and only in men (29.4% among all the observed patients). The observations 24 healthy donors weren't revealed any mutations (p < 0.013-0.001). The hypothesis about the connection between gene polymorphisms which take a part in genome stability and radiosensitivity in Down and Ehlers-Danlos patients was developed.

  19. The Impact of Methylenetetrahydrofolate Reductase C677T Polymorphism on Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation with Methotrexate Prophylaxis

    PubMed Central

    Shin, Dong-Yeop; Koh, Youngil; Yoon, Sung-Soo; Seong, Moon-Woo; Park, Sung Sup; Kim, Jin Hee; Lee, Yun-Gyoo; Kim, Inho

    2016-01-01

    Pharmacogenomics can explain the inter-individual differences in response to drugs, including methotrexate (MTX) used for acute graft-versus-host disease (aGVHD) prophylaxis during hematopoietic stem cell transplantation (HSCT). In real-world practice, preplanned MTX dose is arbitrarily modified according to observed toxicity which can lead to unexpected and severe aGVHD development. We aimed to validate the influence of MTHFR C677T polymorphism on the outcomes of allogenic HSCT in a relatively under-represented homogenous Asian population. A total of 177 patients were divided into 677TT group versus 677C-carriers (677CT+677CC), and clinical outcomes along with baseline characteristics were analyzed and compared. Although there was a tendency towards increased peak liver function test results and accordingly greater delta values between the highest and the baseline in 677TT group, we found no associations between genotypes and hepatotoxicity. However, the incidence of acute liver GVHD (≥ grade 2) was significantly higher in the 677TT group than in the 677CC + 677CT group (P = 0.016). A total of 25 patients (14.1%) expired due to transplantation related mortality (TRM) during the first 180 days after HSCT. Patients carrying 677TT genotype were more likely to experience early TRM than 677C-carriers. The same pattern was observed in the cumulative TRM rate, and 677TT genotype patients were more prone to cumulative TRM (P = 0.010). This translated into shorter OS for patients with 677TT compared to 677C-carriers (P = 0.010). The 3-year survival after HSCT was 29.9% for 677TT cases and 47.1% for 677C-carriers. The multivariate analysis identified 677TT genotype (HR = 1.775. 95% CI 1.122–2.808, P = 0.014) and non-CR state (HR = 2.841. 95% CI 1.627–4.960, P<0.001) as predictors for survival. In conclusion, the MTHFR 677TT genotype appears to be associated with acute liver GVHD, and represent a risk factor for TRM and survival in patients undergoing HSCT with MTX as

  20. Methylenetetrahydrofolate reductase (MTHFR) deficiency enhances resistance against cytomegalovirus infection.

    PubMed

    Fodil-Cornu, N; Kozij, N; Wu, Q; Rozen, R; Vidal, S M

    2009-10-01

    Folates provide one-carbon units for nucleotide synthesis and methylation reactions. A common polymorphism in the MTHFR gene (677C --> T) results in reduced enzymatic activity, and is associated with an increased risk for neural tube defects and cardiovascular disease. The high prevalence of this polymorphism suggests that it may have experienced a selective advantage under environmental pressure, possibly an infectious agent. To test the hypothesis that methylenetetrahydrofolate reductase (MTHFR) genotype influences the outcome of infectious disease, we examined the response of Mthfr-deficient mice against mouse cytomegalovirus (MCMV) infection. Acute MCMV infection of Mthfr(-/-) mice resulted in early control of cytokine secretion, decreased viral titer and preservation of spleen immune cells, in contrast to Mthfr wild-type littermates. The phenotype was abolished in MTHFR transgenic mice carrying an extra copy of the gene. Infection of primary fibroblasts with MCMV showed a decrease in viral replication and in the number of productively infected cells in Mthfr(+/-) fibroblasts compared with wild-type cells. These results indicate that Mthfr deficiency protects against MCMV infection in vivo and in vitro, suggesting that human genetic variants may provide an advantage in the host response against certain pathogens.

  1. Effect of the methylenetetrahydrofolate reductase gene polymorphisms on homocysteine, folate and vitamin B12 in patients with bipolar disorder and relatives.

    PubMed

    Ozbek, Zeynep; Kucukali, Cem Ismail; Ozkok, Elif; Orhan, Nurcan; Aydin, Makbule; Kilic, Gamze; Sazci, Ali; Kara, Ihsan

    2008-07-01

    We investigated the effect of polymorphic variants of c.1298A>C (Glu429Ala) and c.677C>T (Ala222Val) in methylenetetrahydrofolate (MTHFR) gene on the total homocysteine (tHcy), folate and B12 levels in patients with bipolar disorder, first-degree relatives of patients, and controls. The c.677C>T and c.1298A>C polymorphisms in MTHFR were determined by polymerase chain reaction-restriction fragment length polymorphism in 197 bipolar patients, 278 relatives and 238 controls. tHcy and folate and vitamin B12 levels were measured by Fluorescence Polarization Immunoassay and Electrochemiluminescence, respectively. The tHcy was significantly increased in patients and relatives. In contrast, folate and B12 were significantly lower in patients and relatives. Gender was not considered as a significant determinant in the multivariate analysis. Genotypes of c.1298A>C and c.677C>T were correlated with tHcy, folate and B12. Patients and relatives carrying TT and/or AA and AC genotypes had elevated tHcy and reduced folate and B12 levels. High tHcy but low folate and vitamin B12 levels may be a risk factor for development of bipolar disorder.

  2. Plasma folate, methylenetetrahydrofolate reductase (MTHFR), and colorectal cancer risk in three large nested case-control studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few prospective studies have examined the associations between blood levels of folate, in conjunction with methylenetetrahydrofolate reductase (MTHFR) polymorphisms, and colorectal cancer. We evaluated the associations between plasma folate, MTHFR C677T, and A1298C, and colorectal cancer in three la...

  3. Evidence for a Hexaheteromeric Methylenetetrahydrofolate Reductase in Moorella thermoacetica

    PubMed Central

    Mock, Johanna; Wang, Shuning; Huang, Haiyan; Kahnt, Jörg

    2014-01-01

    Moorella thermoacetica can grow with H2 and CO2, forming acetic acid from 2 CO2 via the Wood-Ljungdahl pathway. All enzymes involved in this pathway have been characterized to date, except for methylenetetrahydrofolate reductase (MetF). We report here that the M. thermoacetica gene that putatively encodes this enzyme, metF, is part of a transcription unit also containing the genes hdrCBA, mvhD, and metV. MetF copurified with the other five proteins encoded in the unit in a hexaheteromeric complex with an apparent molecular mass in the 320-kDa range. The 40-fold-enriched preparation contained per mg protein 3.1 nmol flavin adenine dinucleotide (FAD), 3.4 nmol flavin mononucleotide (FMN), and 110 nmol iron, almost as predicted from the primary structure of the six subunits. It catalyzed the reduction of methylenetetrahydrofolate with reduced benzyl viologen but not with NAD(P)H in either the absence or presence of oxidized ferredoxin. It also catalyzed the reversible reduction of benzyl viologen with NADH (diaphorase activity). Heterologous expression of the metF gene in Escherichia coli revealed that the subunit MetF contains one FMN rather than FAD. MetF exhibited 70-fold-higher methylenetetrahydrofolate reductase activity with benzyl viologen when produced together with MetV, which in part shows sequence similarity to MetF. Heterologously produced HdrA contained 2 FADs and had NAD-specific diaphorase activity. Our results suggested that the physiological electron donor for methylenetetrahydrofolate reduction in M. thermoacetica is NADH and that the exergonic reduction of methylenetetrahydrofolate with NADH is coupled via flavin-based electron bifurcation with the endergonic reduction of an electron acceptor, whose identity remains unknown. PMID:25002540

  4. Polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene, intakes of folate and related B vitamins and colorectal cancer: a case-control study in a population with relatively low folate intake.

    PubMed

    Sharp, Linda; Little, Julian; Brockton, Nigel T; Cotton, Seonaidh C; Masson, Lindsey F; Haites, Neva E; Cassidy, Jim

    2008-02-01

    Folate is key in one-carbon metabolism, disruption of which can interfere with DNA synthesis, repair, and methylation. Efficient one-carbon metabolism requires other B vitamins and the optimal activity of enzymes including 5,10-methylenetetrahydrofolate reductase (MTHFR). We report a population-based case-control study of folate intake, related dietary factors and MTHFR polymorphisms (C677T, A1298C) and colorectal cancer in a population with relatively high colorectal cancer incidence and relatively low folate intake. A total of 264 cases with histologically confirmed incident colorectal cancer and 408 controls participated. There was no clear trend in risk with reported intakes of total, or dietary, folate, riboflavin, vitamin B12 or vitamin B6, nor were there interactions between folate intake and the other B vitamins or alcohol. For C677T, risk decreased with increasing variant alleles (multivariate OR for CT v. CC = 0.77 (95 % CI 0.52, 1.16); OR for TT v. CC = 0.62 (95 % CI 0.31, 1.24)), which, although not statistically significant, was consistent with previous studies. For A1298C, compared with AA subjects, CC subjects had modest, non-significant, reduced risk (multivariate OR = 0.81 (95 % CI 0.45, 1.49)). There were significant interactions between total folate and C677T (P = 0.029) and A1298C (P = 0.025), and total vitamin B6 and both polymorphisms (C677T, P = 0.016; A1298C, P = 0.033), although the patterns observed differed from previous studies. Seen against the setting of low folate intake, the results suggest that the role of folate metabolism in colorectal cancer aetiology may be more complex than previously thought. Investigation of particular folate vitamers (for example, tetrahydrofolate, 5,10-methylenetetrahydrofolate) may help clarify carcinogenesis pathways.

  5. The C677T polymorphism of the methylenetetrahydrofolate reductase gene in Mexican mestizo neural-tube defect parents, control mestizo and native populations.

    PubMed

    Dávalos, I P; Olivares, N; Castillo, M T; Cantú, J M; Ibarra, B; Sandoval, L; Morán, M C; Gallegos, M P; Chakraborty, R; Rivas, F

    2000-01-01

    The C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene, associated with the thermolabile form of the enzyme, has reportedly been found to be increased in neural-tube defects (NTD), though this association is still unclear. A group of 107 mestizo parents of NTD children and five control populations: 101 mestizo (M), 50 Huichol (H), 38 Tarahumara (T), 21 Purepecha (P) and 20 Caucasian (C) individuals were typed for the MTHFR C677T variant by the PCR/RFLP (HinfI) method. Genotype frequencies were in agreement with the Hardy-Weinberg expectations in all six populations. Allele frequency (%) of the C677T variant was 45 in NTD, 44 in M, 56 in H, 36 in T, 57 in P, 35 in C. Pairwise inter-population comparisons of allele frequency disclosed a very similar distribution between NTD and M groups (exact test, P=0.92). Among controls, differences between M and individual native groups were NS (0.06

  6. Association study of methylenetetrahydrofolate reductase C677T mutation with cerebral venous thrombosis in an Iranian population.

    PubMed

    Ghaznavi, Habib; Soheili, Zahra; Samiei, Shahram; Soltanpour, Mohammad S

    2015-12-01

    There are limited data on the role of methylenetetrahydrofolate reductase C677T polymorphism and hyperhomocysteinemia as risk factors for cerebral venous thrombosis in Iranian population. We examined a possible association between fasting plasma homocysteine levels, methylenetetrahydrofolate reductase C677T polymorphism, and cerebral venous thrombosis in 50 patients with a diagnosis of cerebral venous thrombosis (20-63 years old) and 75 healthy controls (18-65 years old). Genotyping of the methylenetetrahydrofolate reductase C677T gene polymorphism was performed by PCR-restriction fragment length polymorphism analysis, and homocysteine levels were measured by enzyme immunoassay. Fasting plasma homocysteine levels were significantly higher in cerebral venous thrombosis patients than in controls (P = 0.015). Moreover, plasma homocysteine levels were significantly higher in methylenetetrahydrofolate reductase 677TT genotype compared to 677CT and 677CC genotypes in both cerebral venous thrombosis patients (P = 0.01) and controls (P = 0.03). Neither 677CT heterozygote genotype [odds ratio (OR) 1.35, 95% confidence interval (CI) 0.64-2.84, P = 0.556] nor 677TT homozygote genotype (OR 1.73, 95% CI 0.32-9.21, P = 0.833) was significantly associated with cerebral venous thrombosis. Additionally, no significant differences in the frequency of 677T allele between cerebral venous thrombosis patients and controls were identified (OR 1.31, 95% CI 0.69-2.50, P = 0.512). In conclusion, our study demonstrated that elevated plasma homocysteine levels are significant risk factors for cerebral venous thrombosis. Also, methylenetetrahydrofolate reductase 677TT genotype is not linked with cerebral venous thrombosis, but is a determinant of elevated plasma homocysteine levels.

  7. The prognostic significance of genetic polymorphisms (Methylenetetrahydrofolate Reductase C677T, Methionine Synthase A2756G, Thymidilate Synthase tandem repeat polymorphism) in multimodally treated oesophageal squamous cell carcinoma

    PubMed Central

    Sarbia, M; Stahl, M; von Weyhern, C; Weirich, G; Pühringer-Oppermann, F

    2006-01-01

    The present study retrospectively examined the correlation between the outcome of patients with locally advanced oesophageal squamous cell carcinoma (cT3-4 cN0-1 cM0) after multimodal treatment (radiochemotherapy±surgical resection), and the presence of genetic polymorphisms in genes involved in folate metabolism. In total, 68 patients who took part in a prospective multicentric trial received 5-fluorouracil (FU)-based radiochemotherapy, optionally followed by surgery. DNA was extracted from pretherapeutic tumour biopsies and was subsequently genotyped for common genetic polymorphisms of three genes (MTHFR C677T, MTR A2756G, TS tandem repeat polymorphism) involved in folate metabolism and potentially in sensitivity to 5-FU-based chemotherapy. The genotypes were correlated with tumour response to polychemotherapy, radiochemotherapy and with overall survival. Tumours with the MTR wild-type genotype (2756AA) showed a median survival time of 16 months, whereas tumours with an MTR variant genotype (2756AG/2756GG) showed a median survival time of 42 months (P=0.0463). No prognostic impact could be verified for the genotypes of the MTHFR genes and the TS gene. Among tumours treated with radiochemotherapy and subsequent resection, MTR variant genotype showed higher histopathological response rate than tumours with MTR wild-type genotype (P=0.0442). In contrast, no significant relationship between clinically determined tumour regression after polychemotherapy and polymorphisms of the three genes under analysis was observed. In conclusion, pretherapeutic determination of the MTR A2756G polymorphism may predict survival of multimodally treated oesophageal squamous cell carcinomas. Determination of MTHFR C677T and TS tandem repeat polymorphism has no predictive value. PMID:16333305

  8. The prognostic significance of genetic polymorphisms (Methylenetetrahydrofolate Reductase C677T, Methionine Synthase A2756G, Thymidilate Synthase tandem repeat polymorphism) in multimodally treated oesophageal squamous cell carcinoma.

    PubMed

    Sarbia, M; Stahl, M; von Weyhern, C; Weirich, G; Pühringer-Oppermann, F

    2006-01-30

    The present study retrospectively examined the correlation between the outcome of patients with locally advanced oesophageal squamous cell carcinoma (cT3-4 cN0-1 cM0) after multimodal treatment (radiochemotherapy+/-surgical resection), and the presence of genetic polymorphisms in genes involved in folate metabolism. In total, 68 patients who took part in a prospective multicentric trial received 5-fluorouracil (FU)-based radiochemotherapy, optionally followed by surgery. DNA was extracted from pretherapeutic tumour biopsies and was subsequently genotyped for common genetic polymorphisms of three genes (MTHFR C677T, MTR A2756G, TS tandem repeat polymorphism) involved in folate metabolism and potentially in sensitivity to 5-FU-based chemotherapy. The genotypes were correlated with tumour response to polychemotherapy, radiochemotherapy and with overall survival. Tumours with the MTR wild-type genotype (2756AA) showed a median survival time of 16 months, whereas tumours with an MTR variant genotype (2756AG/2756GG) showed a median survival time of 42 months (P=0.0463). No prognostic impact could be verified for the genotypes of the MTHFR genes and the TS gene. Among tumours treated with radiochemotherapy and subsequent resection, MTR variant genotype showed higher histopathological response rate than tumours with MTR wild-type genotype (P=0.0442). In contrast, no significant relationship between clinically determined tumour regression after polychemotherapy and polymorphisms of the three genes under analysis was observed. In conclusion, pretherapeutic determination of the MTR A2756G polymorphism may predict survival of multimodally treated oesophageal squamous cell carcinomas. Determination of MTHFR C677T and TS tandem repeat polymorphism has no predictive value.

  9. A new and improved method based on polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for the determination of A1298C mutation in the methylenetetrahydrofolate reductase (MTHFR) gene.

    PubMed

    Machnik, Grzegorz; Zapala, Malgorzata; Pelc, Ewa; Gasecka-Czapla, Monika; Kaczmarczyk, Grzegorz; Okopien, Boguslaw

    2013-01-01

    Intracellular folate homeostasis and metabolism is regulated by numerous genes. Among them, 5,10-methylenetetrahydrofolate reductase (MTHFR) is of special interest because of its involvement in regulation of the homocysteine level in the body as a result of folate metabolism. Moreover, some studies demonstrated that the homocysteine plasma level in individuals may be influenced by polymorphisms present in the MTHFR gene. Two common, clinically relevant mutations have been described: MTHFR C677T and MTHFR A1298C. Although several laboratory techniques allow genotyping of both polymorphisms, PCR-RFLP analysis is simple to perform, relatively cheap, and thus one of the most utilized. In the case of A1298C, the PCR-RFLP technique that utilizes MboII endonuclease class II requires an acrylamide gel electrophoresis, since agarose gel electrophoresis is unable to resolve short deoxyribonucleic acid (DNA) fragments after restriction digestion. Agarose gel electrophoresis is commonly preferred over that of acrylamide. To resolve this inconvenience, a novel PCR-RFLP, AjuI-based method to genotype A1298C alleles has been developed that can be performed on standard agarose gel.

  10. Interactions among methylenetetrahydrofolate reductase (MTHFR) and cystathionine β-synthase (CBS) polymorphisms - a cross-sectional study: multiple heterozygosis as a risk factor for higher homocysteine levels and vaso-occlusive episodes.

    PubMed

    Amaral, F M; Miranda-Vilela, A L; Lordelo, G S; Ribeiro, I F; Daldegan, M B; Grisolia, C K

    2017-02-23

    High plasma homocysteine (Hcy) ​​levels may be responsible for vaso-occlusive episodes and may have acquired and/or genetic causes. This cross-sectional study aimed to investigate the role of methylenetetrahydrofolate reductase (MTHFR; C677T; A1298C) and cystathionine-β-synthase (CBS; T833C/844ins68, G919A) polymorphisms in serum levels of folic acid, vitamin B12 and Hcy, and to verify a possible association between these polymorphisms and the clinical variability. Blood samples of Brazilian patients with a diagnosis of thrombosis were submitted to genotyping by PCR-based methods and serum dosages of folic acid, vitamin B12 and Hcy. Except for the CBS G919A polymorphism, all other genetic markers were in Hardy-Weinberg equilibrium. An increased risk for venous thrombosis was found for the MTHFR 1298CC carriers (OR = 1.688; 95%CI = 0.839-3.398, P = 0.018) and those homozygously mutant for the CBS haplotype 844ins68/T833C (OR = 2.488; 95%CI = 0.501-12.363, P = 0.031), while heterozygous for this CBS haplotype showed an increased risk for higher Hcy levels (OR = 5.900; 95%CI = 1.003-34.691, P = 0.030). Significant interactions were observed among the MTHFR C677T, MTHFR A1298C and CBS haplotype 844ins68/T833C polymorphisms in the results for Hcy levels (P = 0.000), where heterozygous had higher values. Interactions among these polymorphisms can affect serum Hcy levels, where multiple heterozygosis could be a risk factor for vaso-occlusive episodes.

  11. 5,10-Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms: genotype frequency and association with homocysteine and folate levels in middle-southern Italian adults.

    PubMed

    Zappacosta, Bruno; Graziano, Mirella; Persichilli, Silvia; Di Castelnuovo, Augusto; Mastroiacovo, Pierpaolo; Iacoviello, Licia

    2014-01-01

    Two genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene (C677T and A1298C) can influence the plasma homocysteine (Hcy) levels, especially in the presence of an inadequate folate status. The aim of this study was to evaluate the frequencies of C677T and of A1298C MTHFR polymorphisms and their correlation with Hcy and serum folate concentrations in a population of blood donors living in a region of middle-southern Italy (the Molise Region). One hundred ninety seven blood donors were studied for total plasma Hcy, serum folate and C677T and A1298C MTHFR genotypes. The frequency of C677T genotypes was 20.8% (CC), 49.8% (CT) and 29.4% (TT); for the A1298C genotypes: 48.7% (AA), 43.7% (AC) and 7.6% (CC). Hcy and serum folate concentrations were significantly different among genotypes of the C677T polymorphism (CC versus CT versus TT: <0.0001 both for Hcy and folate), with Hcy values increasing, and serum folate decreasing, from CC to TT subjects. Regarding to A1298C polymorphism, the difference among genotypes (AA versus AC versus CC; p: 0.026 for Hcy and 0.014 for serum folate), showed an opposite trend for both parameters, with Hcy higher in the wild-type and lower in the homozygotes and serum folate higher in CC than in AA subjects. In conclusion, we found a high frequency of MTHFR allele associated with high level of Hcy and low levels of folate in an Italian southern population.

  12. Methylenetetrahydrofolate Reductase C677T: Hypoplastic Left Heart and Thrombosis.

    PubMed

    Spronk, Kimberly J; Olivero, Anthony D; Haw, Marcus P; Vettukattil, Joseph J

    2015-10-01

    The incidence of congenital heart defects is higher in infants with mutation of methylenetetrahydrofolate reductase (MTHFR) gene. The MTHFR C677T gene decreases the bioavailability of folate and increases plasma homocysteine, a risk factor for thrombosis. There have been no reported cases in the literature on the clinical implications of this procoagulable state in the setting of cyanotic heart disease, which itself has prothrombotic predisposition. Two patients with hypoplastic left heart syndrome developed postoperative thrombotic complications, both were homozygous for MTHFR C677T. We present these cases and highlight the implications of MTHFR mutation in the management of complex congenital heart disease.

  13. Role of polymorphisms in factor V (FV Leiden), prothrombin, plasminogen activator inhibitor type-1 (PAI-1), methylenetetrahydrofolate reductase (MTHFR) and cystathionine β-synthase (CBS) genes as risk factors for thrombophilias.

    PubMed

    Miranda-Vilela, A L

    2012-09-01

    Thrombophilias are defined as a predisposition to thrombosis due to hematological changes which induce blood hypercoagulability; they can be inherited or acquired. They are individually characterized by a large phenotypic variability, even when they occur within the same family. Hereditary thrombophilias are, in most cases, due to changes related to physiological coagulation inhibitors or mutations in the genes of coagulation factors. High levels of plasma homocysteine may also be responsible for vaso-occlusive episodes and may have acquired (nutritional deficiencies of folate and vitamins B6 and B12) and/or genetic causes (mutations in the genes responsible for expression of enzymes involved in the intracellular metabolism of homocysteine). Considering that: (1) thromboses are events of multigenic and multifactorial etiopathology; (2) the presence of mutations in several genes significantly increases the risk of their occurrence; (3) the vascular territory (venous and/or arterial) affected involves different pathophysiological mechanisms and treatments, knowledge of genetic variants that may contribute to the risk and variability of the phenotypic manifestations of these diseases is extremely important. This understanding may provide support for a more individualized and therefore more effective treatment for thrombophilia carriers. Thus, this mini-review aims to address a comprehensive summary of thrombophilias and thrombosis, and discuss the role of polymorphisms in Factor V (FV Leiden), Prothrombin, Plasminogen activator inhibitor type-1 (PAI-1), Methylenetetrahydrofolate reductase (MTHFR) and Cystathionine β-synthase (CBS) genes as risk factors for thrombophilias.

  14. Methylenetetrahydrofolate reductase (MTHFR) polymorphism A1298C (Glu429Ala) predicts decline in renal function over time in the African-American Study of Kidney Disease and Hypertension (AASK) Trial and Veterans Affairs Hypertension Cohort (VAHC)

    PubMed Central

    Salem, Rany M.; Lipkowitz, Michael S.; Bhatnagar, Vibha; Pandey, Braj; Schork, Nicholas J.; O’Connor, Daniel T.

    2012-01-01

    Background. Hyperhomocysteinemia is associated with increased venous thrombosis and cardiovascular disease (CVD). Mutations in the human methylenetetrahydrofolate reductase (MTHFR) gene have been associated with increased homocysteine levels and risks of CVD in various populations including those with kidney disease. Here, we evaluated the influence of MTHFR variants on progressive loss of kidney function. Methods. We analyzed 821 subjects with hypertensive nephrosclerosis from the longitudinal National Institute of Diabetes and Digestive and Kidney Diseases African-American Study of Kidney Disease and Hypertension (AASK) Trial to determine whether decline in glomerular filtration rate (GFR) over ∼4.2 years was predicted by common genetic variation within MTHFR at non-synonymous positions C677T (Ala222Val) and A1298C (Glu429Ala) or by MTHFR haplotypes. The effect on GFR decline was then supported by a study of 1333 subjects from the San Diego Veterans Affairs Hypertension Cohort (VAHC), followed over ∼4.5 years. Linear effect models were utilized to determine both genotype [single-nucleotide polymorphism (SNP)] and genotype (SNP)-by-time interactions. Results. In AASK, the polymorphism at A1298C predicted the rate of GFR decline: A1298/A1298 major allele homozygosity resulted in a less pronounced decline of GFR, with a significant SNP-by-time interaction. An independent follow-up study in the San Diego VAHC subjects supports that A1298/A1298 homozygotes have the greatest estimated GFR throughout the study. Haplotype analysis with C677T yielded concurring results. Conclusion. We conclude that the MTHFR-coding polymorphism at A1298C is associated with renal decline in African-Americans with hypertensive nephrosclerosis and is supported by a veteran cohort with a primary care diagnosis of hypertension. Further investigation is needed to confirm such findings and to determine what molecular mechanism may contribute to this association. PMID:21613384

  15. Seven novel mutations in the methylenetetrahydrofolate reductase gene and genotype/phenotype correlations in severe methylenetetrahydrofolate reductase deficiency

    SciTech Connect

    Goyette, P.; Frosst, P.; Rosenblatt, D.S.; Rozen. R.

    1995-05-01

    5-Methyltetrahydrofolate, the major form of folate in plasma, is a carbon donor for the remethylation of homocysteine to methionine. This form of folate is generated from 5,10-methylenetetrahydrofolate through the action of 5,10-methylenetetrahydrofolate reductase (MTHFR), a cytosolic flavoprotein. Patients with an autosomal recessive severe deficiency of MTHFR have homocystinuria and a wide range of neurological and vascular disturbances. We have recently described the isolation of a cDNA for MTHFR and the identification of two mutations in patients with severe MTHFR deficiency. We report here the characterization of seven novel mutations in this gene: six missense mutations and a 5{prime} splice-site defect that activates a cryptic splice in the coding sequence. We also present a preliminary analysis of the relationship between genotype and phenotype for all nine mutations identified thus far in this gene. A nonsense mutation and two missense mutations (proline to leucine and threonine to methionine) in the homozygous state are associated with extremely low activity (0%-3%) and onset of symptoms within the 1st year of age. Other missense mutations (arginine to cysteine and arginine to glutamine) are associated with higher enzyme activity and later onset of symptoms. 19 refs., 4 figs., 2 tabs.

  16. Genetic variants in 3'-UTRs of methylenetetrahydrofolate reductase (MTHFR) predict colorectal cancer susceptibility in Koreans.

    PubMed

    Jeon, Young Joo; Kim, Jong Woo; Park, Hye Mi; Kim, Jung O; Jang, Hyo Geun; Oh, Jisu; Hwang, Seong Gyu; Kwon, Sung Won; Oh, Doyeun; Kim, Nam Keun

    2015-06-05

    Polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) play important roles in tumor development, progression, and metastasis. Moreover, recent studies have reported that a number of 3'-UTR polymorphisms potentially bind to specific microRNAs in a variety of cancers. The aim of this study was to investigate the association of four MTHFR polymorphisms, 2572C>A [rs4846049], 4869C>G [rs1537514], 5488C>T [rs3737967], and 6685T>C [rs4846048] with colorectal cancer (CRC) in Koreans. A total of 850 participants (450 CRC patients and 400 controls) were enrolled in the study. The genotyping of MTHFR 3'-UTR polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism analysis or TaqMan allelic discrimination assay. We found that MTHFR 2572C>A, 4869C>G, and 5488C>T genotypes were substantially associated with CRC susceptibility. Of the potentially susceptible polymorphisms, MTHFR 2572C>A was associated with increased homocysteine and decreased folate levels in the plasma based on MTHFR 677CC. Our study provides the evidences for 3'-UTR variants in MTHFR gene as potential biomarkers for use in CRC prevention.

  17. Distribution of common methylenetetrahydrofolate reductase gene mutations in patients with obstructive sleep apnoea.

    PubMed

    Bekci, T T; Kocak, N; Kesli, R

    2009-01-01

    Homocysteine levels have been investigated in patients with obstructive sleep apnoea syndrome (OSAS), a syndrome associated with a high level of comorbid cardiovascular disease (CVD). While significant increases in homocysteine levels have been observed in OSAS patients with CVD, no increases have been noted in OSAS patients without CVD. This study was designed to investigate the methylenetetrahydrofolate reductase (MTHFR) gene, which is essential for homocysteine metabolism and has been shown to have a causal role in the development of CVD. Eighty subjects, 30 diagnosed with OSAS by polysomnography and 50 controls (healthy volunteers with no symptoms of OSAS) were enrolled. Two mutations in the MTHFR gene were investigated using polymerase chain reactions and restriction fragment length polymorphisms. No significant differences were found in mean age, body mass index, homocysteine levels, or MTHFR allele or genotype distributions between patient and control groups.

  18. Severe scoliosis in a patient with severe methylenetetrahydrofolate reductase deficiency.

    PubMed

    Munoz, Tatiana; Patel, Jinesh; Badilla-Porras, Ramses; Kronick, Jonathan; Mercimek-Mahmutoglu, Saadet

    2015-01-01

    Severe methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare autosomal recessively inherited inborn error of folate metabolism. We report a new patient with severe MTHFR deficiency who presented at age 4 months with early onset severe scoliosis associated with severe hypotonia. Markedly decreased MTHFR enzyme activity (0.3 nmoles CHO/mg protein/h; reference range>9) and compound heterozygous mutations (c. 1304T>C; p.Phe435Ser and c.1539dup; p.Glu514Argfs∗24) in the MTHFR gene confirmed the diagnosis. She was treated with vitamin B12, folic acid and betaine supplementation and showed improvements in her developmental milestones and hypotonia. To the best of our knowledge, this is the first patient with MTHFR deficiency reported with severe early onset scoliosis. Despite the late diagnosis and treatment initiation, she showed favorable short-term neurodevelopmental outcome. This case suggests that homocysteine measurement should be included in the investigations of patients with developmental delay, hypotonia and scoliosis within first year of life prior to organizing genetic investigations.

  19. Mutation Update and Review of Severe Methylenetetrahydrofolate Reductase Deficiency.

    PubMed

    Froese, D Sean; Huemer, Martina; Suormala, Terttu; Burda, Patricie; Coelho, David; Guéant, Jean-Louis; Landolt, Markus A; Kožich, Viktor; Fowler, Brian; Baumgartner, Matthias R

    2016-05-01

    Severe 5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency is caused by mutations in the MTHFR gene and results in hyperhomocysteinemia and varying severity of disease, ranging from neonatal lethal to adult onset. Including those described here, 109 MTHFR mutations have been reported in 171 families, consisting of 70 missense mutations, 17 that primarily affect splicing, 11 nonsense mutations, seven small deletions, two no-stop mutations, one small duplication, and one large duplication. Only 36% of mutations recur in unrelated families, indicating that most are "private." The most common mutation is c.1530A>G (numbered from NM_005957.4, p.Lys510 = ) causing a splicing defect, found in 13 families; the most common missense mutation is c.1129C>T (p.Arg377Cys) identified in 10 families. To increase disease understanding, we report enzymatic activity, detected mutations, and clinical onset information (early, <1 year; or late, >1 year) for all published patients available, demonstrating that patients with early onset have less residual enzyme activity than those presenting later. We also review animal models, diagnostic approaches, clinical presentations, and treatment options. This is the first large review of mutations in MTHFR, highlighting the wide spectrum of disease-causing mutations.

  20. Folic acid rivals methylenetetrahydrofolate reductase (MTHFR) gene-silencing effect on MEPM cell proliferation and apoptosis.

    PubMed

    Xiao, Wen-Lin; Wu, Min; Shi, Bing

    2006-11-01

    It's clear that environmental factors play a role in the aetiology of orofacial clefting (OFC) and an important area of future research will be to unravel interactions that occur between candidate genes and environmental factors during early development of the embryo. Periconceptional folic acid supplementation may reduce the risk of OFC. Polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene reduce availability of 5-methylenetetrahydrofolate, the predominant circulating form of folic acid. To determine the effect of MTHFR gene mutation on murine embryonic palatal mesenchymal (MEPM) cells and the interaction with folic acid supplement, we used RNAi study in the primary cultures of MEPM cells. The cells of MTHFR gene silencing grew slower and the apoptosis cell number was more than the cells of control. Supplement with 20 microg/ml folic acid was the best to preventing teratogenic effect of MTHFR gene silencing. By flow cytometry analysis of cell cycle, results were shown that the MEPM cells were retarded in G(0)/G(1) after MTHFR gene silencing. While using 20 microg/ml folic acid supplements could make cell transit the G(1)/S restriction point and the cells growth was close to normal level.

  1. Association of methylenetetrahydrofolate reductase and methionine synthase polymorphisms with breast cancer risk and interaction with folate, vitamin B6, and vitamin B 12 intakes.

    PubMed

    Jiang-Hua, Qiao; De-Chuang, Jiao; Zhen-Duo, Lu; Shu-de, Cui; Zhenzhen, Liu

    2014-12-01

    We assessed the association between dietary intake of folate and the MTHFR genotype with breast cancer in a Chinese population, with additional analysis of the interactions of gene polymorphisms and dietary intake of folate, vitamin B6, and vitamin B12. A case-control study was performed, and 535 patients with newly diagnosed breast cancer and 673 controls were enrolled into this study. The MTHFR 667TT genotype (odds ratio (OR) = 1.82, 95 % confidence interval (CI) = 1.24-2.97) and T allele (OR 0= 1.48, 95 % CI = 1.15-1.78) were correlated with a moderately significant increased risk of breast cancer when compared with the CC genotype. Individuals carrying the MTR 2756GG genotype (OR = 1.66, 95 % CI = 1.16-2.56) and G allele (OR = 1.42, 95 % CI = 1.26-1.81) had a higher risk of breast cancer when compared with subjects with the AA genotype. The MTHFR 667 T allele and MTR 2756 G allele were associated with a higher risk of breast cancer in individuals with low folate intake, vitamin B6, and vitamin B12, but the association disappeared among subjects with moderate and high intake of folate, vitamin B6, and vitamin B12. This case-control study found that the MTHFR C677T and MTR A2756G polymorphisms are associated with risk of breast cancer, and folate, vitamin B6, and vitamin B12 intakes influence these associations.

  2. Maternal Supplementary Folate Intake, Methylenetetrahydrofolate Reductase (MTHFR) C677T and A1298C Polymorphisms and the Risk of Orofacial Cleft in Iranian Children

    PubMed Central

    Ebadifar, Asghar; KhorramKhorshid, Hamid Reza; Kamali, Koorosh; Salehi Zeinabadi, Mehdi; Khoshbakht, Tayyebeh; Ameli, Nazila

    2015-01-01

    Background: The purpose of this study was to describe the association of MTHFR gene single nucleotide polymorphisms (C677T and A1298C) and maternal supplementary folate intake with orofacial clefts in the Iranian population. Methods: In this case-control study, peripheral venous blood was taken from 65 patients with orofacial clefts and 215 unaffected controls for DNA extraction and kept in EDTA for further analysis. The genotyping was carried out using Polymerase Chain Reaction (PCR) followed by Restriction Fragment Length Polymorphism (RFLP) and gel electrophoresis. Data were analyzed using Chi square test and logistic regression tests. Results: Genotype frequencies of 677TT were reported to be 13.5 and 36.1% in controls and CL/P patients, respectively, which showed a significant difference compared to CC as reference (OR=4.118; 95% CI=1.997–8.492; p=0.001). Conversely, 1298CC with frequencies of 10.8 and 12.7% in controls and patients, respectively, showed no significant difference compared to AA (OR=2.359; 95% CI=0.792–7.023; p=0.123). Comparing patients whose mothers did not report the folate supplement intake during pregnancy, to controls, it was observed that lack of folate intake was a predisposing factor for having a child with oral clefts (OR=5/718, p=0.000). Conclusion: Children carrying the 677TT variant of the MTHFR gene may have an increased risk of CL/P. In addition, the finding that the risk associated with this allele was obviously higher when the mothers didn’t use folic acid, supports the hypothesis that folic acid may play a role in the etiology of CL/P. PMID:26140186

  3. Status of vitamin B-12 and B-6 but not of folate, homocysteine and the methylenetetrahydrofolate reductase C677T polymorphism are associated with impaired cognition and depression in adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene differs in frequency in different ethnic groups which have differing prevalence of age-related cognitive impairments. We used a battery of neuropsychological tests to examine association of the MTHFR C677T polymorphism w...

  4. Methylenetetrahydrofolate reductase (MTHFR) genotype, smoking habit, metastasis and oral cancer in Taiwan.

    PubMed

    Tsai, Chia-Wen; Hsu, Chia-Fang; Tsai, Ming-Hsui; Tsou, Yung-An; Hua, Chun-Hung; Chang, Wen-Shin; Lin, Cheng-Chieh; Bau, Da-Tian

    2011-06-01

    The aim of this study was to evaluate the association and interaction of genotypic polymorphism in methylenetetrahydrofolate reductase (MTHFR) with smoking habits and oral cancer in Taiwan. Two well-known polymorphic variants of MTHFR, C677T (rs1801133) and A1298C (rs1801131), were analyzed in association with oral cancer risk, and their joint effects with individual smoking habits on oral cancer risk are discussed. In total, 620 oral cancer patients and 620 non-cancer controls in central Taiwan were recruited and genotyped. The MTHFR C677T genotype, but not the A1298C, was differently distributed between the oral cancer and control groups. The T allele of MTHFR C677T was significantly more frequently found in controls than in oral cancer patients. Joint effects of smoking and MTHFR C677T genotype significantly affected oral cancer susceptibility. The MTHFR C677T CT and TT genotypes in association with smoking conferred lower odds ratios of 0.66 and 0.54 (95% confidence interval=0.49-0.82 and 0.39-0.86), respectively. Those patients with MTHFR C677T CT and TT genotypes also had a lower risk of oral cancer metastasis. MTHFR C677T genotype may have joint effects with smoking on oral carcinogenesis, and may be a useful biomarker for prediction and prognosis of oral cancer.

  5. The association between end-stage diabetic nephropathy and methylenetetrahydrofolate reductase genotype with macroangiopathy in type 2 diabetes mellitus.

    PubMed

    Hasegawa, G; Obayashi, H; Kamiuchi, K; Nakai, M; Kanatsuna, T; Yamaguchi, M; Tanaka, T; Shigeta, H; Fujii, M; Yoshikawa, T; Nakamura, N

    2003-05-01

    The T/T genotype of the methylenetetrahydrofolate reductase C677 T gene polymorphism is associated with elevated homocysteine levels and presumably with increased atherosclerotic risk. We evaluated the interaction between this gene polymorphism and end-stage diabetic nephropathy on the observed prevalence of macroangiopathy in type 2 diabetes mellitus. The methylenetetrahydrofolate reductase 677 C/T genotypes were determined in 174 type 2 diabetic patients: 80 with and 94 without renal failure due to diabetic nephropathy. In the patients with renal failure, the T/T genotype and T allele were significantly associated with macroangiopathy (T/T; 31 % vs. 2 %, P = 0.0001 T allele; 59 % vs. 29 %, P = 0.00014), whereas the associations were not significant in the patients without renal failure. In the multiple logistic regression analysis, age (10 years OR 4.05 [1.79 - 9.31], P < 0.0005) and 677 T allele (6.84 [2.12 - 22.05], P = 0.0013) were significantly associated with macroangiopathy in the patients with renal failure. In conclusion, this study demonstrated that the 677 T/T genotype and T allele of MTHFR were significantly associated with macroangiopathy in type 2 diabetic patients with renal failure. The MTHFR 677 T allele, together with renal dysfunction due to diabetic nephropathy, could be a strong risk factor for atherosclerotic disease.

  6. Folate metabolism gene 5,10-methylenetetrahydrofolate reductase (MTHFR) is associated with ADHD in myelomeningocele patients.

    PubMed

    Spellicy, Catherine J; Northrup, Hope; Fletcher, Jack M; Cirino, Paul T; Dennis, Maureen; Morrison, Alanna C; Martinez, Carla A; Au, Kit Sing

    2012-01-01

    The objective of this study was to examine the relation between the 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene and behaviors related to attention- deficit/hyperactivity disorder (ADHD) in individuals with myelomeningocele. The rationale for the study was twofold: folate metabolizing genes, (e.g. MTHFR), are important not only in the etiology of neural tube defects but are also critical to cognitive function; and individuals with myelomeningocele have an elevated incidence of ADHD. Here, we tested 478 individuals with myelomeningocele for attention-deficit hyperactivity disorder behavior using the Swanson Nolan Achenbach Pelham-IV ADHD rating scale. Myelomeningocele participants in this group for whom DNAs were available were genotyped for seven single nucleotide polymorphisms (SNPs) in the MTHFR gene. The SNPs were evaluated for an association with manifestation of the ADHD phenotype in children with myelomeningocele. The data show that 28.7% of myelomeningocele participants exhibit rating scale elevations consistent with ADHD; of these 70.1% had scores consistent with the predominantly inattentive subtype. In addition, we also show a positive association between the SNP rs4846049 in the 3'-untranslated region of the MTHFR gene and the attention-deficit hyperactivity disorder phenotype in myelomeningocele participants. These results lend further support to the finding that behavior related to ADHD is more prevalent in patients with myelomeningocele than in the general population. These data also indicate the potential importance of the MTHFR gene in the etiology of the ADHD phenotype.

  7. The Association of Methylenetetrahydrofolate Reductase Genotypes with the Risk of Childhood Leukemia in Taiwan

    PubMed Central

    Chang, Wen-Shin; Ji, Hong-Xue; Hsiao, Chieh-Lun; Miao, Chia-En; Hsu, Yuan-Nian; Bau, Da-Tian

    2015-01-01

    Background Acute lymphoblastic leukemia (ALL) is the most prevalent type of pediatric cancer, the causes of which are likely to involve an interaction between genetic and environmental factors. To evaluate the effects of the genotypic polymorphisms in methylenetetrahydrofolate reductase (MTHFR) on childhood ALL risk in Taiwan, two well-known polymorphic genotypes of MTHFR, C677T (rs1801133) and A1298C (rs1801131), were analyzed to examine the extent of their associations with childhood ALL susceptibility and to discuss the MTHFR genotypic contribution to childhood ALL risk among different populations. Methodology/Principal Findings In total, 266 patients with childhood ALL and an equal number of non-cancer controls recruited were genotyped utilizing PCR-RFLP methodology. The MTHFR C677T genotype, but not the A1298C, was differently distributed between childhood ALL and control groups. The CT and TT of MTHFR C677T genotypes were significantly more frequently found in controls than in childhood ALL patients (odds ratios=0.60 and 0.48, 95% confidence intervals=0.42–0.87 and 0.24–0.97, respectively). As for gender, the boys carrying the MTHFR C677T CT or TT genotype conferred a lower odds ratio of 0.51 (95% confidence interval=0.32–0.81, P=0.0113) for childhood ALL. As for age, those equal to or greater than 3.5 years of age at onset of disease carrying the MTHFR C677T CT or TT genotype were of lower risk (odds ratio= 0.43 and 95% confidence interval=0.26–0.71, P=0.0016). Conclusions Our results indicated that the MTHFR C677T T allele was a protective biomarker for childhood ALL in Taiwan, and the association was more significant in male patients and in patients 3.5 years of age or older at onset of disease. PMID:25793509

  8. Free-floating thrombus of the carotid artery with a homozygous methylenetetrahydrofolate reductase gene mutation: a case report.

    PubMed

    Colak, Necmettin; Nazli, Yunus; Kosehan, Dilek; Alpay, Mehmet Fatih; Cakir, Omer

    2013-02-01

    Free-floating thrombus (FFT) of the carotid artery is a rare condition of currently unknown etiology. We describe a symptomatic patient with an FFT in the left common carotid artery. A duplex ultrasonography scan showed the presence of a mobile floating thrombus moving in cyclical motion with the cardiac cycles in the left common carotid artery. During emergency surgery, an FFT was seen at this location and removed. No underlying wall defect was seen at the time of surgery. In a genetic screening test, TT homozygous for the methylenetetrahydrofolate reductase (MTHFR) C677T genetic polymorphisms was detected. The patient recovered uneventfully, with no neurogical events. Lifelong anticoagulant therapy was recommended. An aggressive surgical approach is recommended in the patient to prevent embolic episodes.

  9. Neonatal stroke associated with de novo antiphospholipid antibody and homozygous 1298C/C methylenetetrahydrofolate reductase mutation

    PubMed Central

    Rego Sousa, Paulo; Figueira, Ricardo; Vasconcellos, Rui

    2012-01-01

    Antiphospholipid antibodies are a recognised prothrombotic risk factor associated with acute ischaemic infarction. Most autoimmune diseases are rare in infants, and in the neonatal period, autoimmunity is related to transplacental passage of maternal immunoglobulin G autoantibodies. Distinguishing between de novo and acquired autoimmunity has important therapeutic implications and is crucial for determining the prognosis. We present a case of a neonatal thrombotic stroke associated with de novo synthesis of antiphospholipid antibodies, a homozygous 1298C/C methylene-tetrahydrofolate reductase mutation and a double-homozygous plasminogen activator inhibitor 1 polymorphism (PAI-1 844A/A and 675 4G/4G), which may have increased the final thrombotic risk. Her mother was not positive for antiphospholipid antibodies. The authors highlight an unequivocal evidence of a de novo case of paediatric antiphospholipid antibody syndrome and emphasise the need for a thorough investigation in cases of neonatal stroke including molecular thrombophilia study. PMID:23162020

  10. Genistein inhibits activities of methylenetetrahydrofolate reductase and lactate dehydrogenase, enzymes which use NADH as a substrate.

    PubMed

    Grabowski, Michał; Banecki, Bogdan; Kadziński, Leszek; Jakóbkiewicz-Banecka, Joanna; Kaźmierkiewicz, Rajmund; Gabig-Cimińska, Magdalena; Węgrzyn, Grzegorz; Węgrzyn, Alicja; Banecka-Majkutewicz, Zyta

    2015-09-25

    Genistein (5, 7-dihydroxy-3- (4-hydroxyphenyl)-4H-1-benzopyran-4-one) is a natural isoflavone revealing many biological activities. Thus, it is considered as a therapeutic compound in as various disorders as cancer, infections and genetic diseases. Here, we demonstrate for the first time that genistein inhibits activities of bacterial methylenetetrahydrofolate reductase (MetF) and lactate dehydrogenase (LDH). Both enzymes use NADH as a substrate, and results of biochemical as well as molecular modeling studies with MetF suggest that genistein may interfere with binding of this dinucleotide to the enzyme. These results have implications for our understanding of biological functions of genistein and its effects on cellular metabolism.

  11. Methylenetetrahydrofolate reductase homozygous mutation in a young boy with cerebellar infarction.

    PubMed

    Spalice, Alberto; Del Balzo, Francesca; Perla, Francesco Massimo; Properzi, Enrico; Carducci, Carla; Antonozzi, Italo; Iannetti, Paola

    2009-06-08

    Posterior circulation vascular occlusive disease in children is a rare and uncommonly reported event. Among the numerous risk factors, the methylenetetrahydrofolate reductase (MTHFR) mutation is considered to be a common genetic cause of thrombosis in adults and children. Recently, a link between the MTHFR mutation and cerebrovascular disorders was reported in children. Diffusion tensor imaging (DTI) is a great improvement on magnetic resonance imaging (MRI), making the in vivo anatomical and pathological study of the brain and its fibers possible. In our patient cerebellar infarction was associated with MTHFR mutation and, in a standard neurological examination, DTI revealed normal white matter tracts.

  12. A founder mutation causing a severe methylenetetrahydrofolate reductase (MTHFR) deficiency in Bukharian Jews.

    PubMed

    Ben-Shachar, Shay; Zvi, Tal; Rolfs, Arndt; Breda Klobus, Andrea; Yaron, Yuval; Bar-Shira, Anat; Orr-Urtreger, Avi

    2012-11-01

    Methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare autosomal recessive disorder. A novel homozygous MTHFR c.474A>T (p.G158G) mutation was detected in two unrelated children of Jewish Bukharian origin. This mutation generates an abnormal splicing and early termination codon. A carrier frequency of 1:39 (5/196) was determined among unrelated healthy Bukharian Jews. Given the disease severity and allele frequency, a population screening for individuals of this ancestry is warranted in order to allow prenatal, or preimplantation diagnosis.

  13. Population distribution of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C risk alleles for methotrexate toxicity in Israel.

    PubMed

    Efrati, Edna; Elkin, Hela; Nahum, Sagi; Krivoy, Norberto

    2013-04-01

    Methylenetetrahydrofolate reductase (MTHFR) is a central regulatory enzyme in the folate pathway. Two non-synonymous single nucleotide polymorphisms in MTHFR, C677T (rs1801133) and A1298C (rs1801131) have been associated with reduced MTHFR enzyme activity. These polymorphisms, especially C677T, appear to be linked with methotrexate-related toxicity, particularly hepatotoxicity; thus, pretreatment identification of individuals carrying these polymorphisms may be of clinical relevance. The purpose of this study was to determine the frequency and distribution of MTHFR polymorphic variants, known to functionally impair MTHFR activity, in the highly heterogeneous Israeli population. MTHFR genotyping was carried out in the representatives of three major demographic groups in Israel by PCR-restriction fragment length polymorphism and high-resolution melting. The relative distribution of variant alleles 677T and 1298C was found to be similar in individuals of Jewish, Druze and Arab Moslem descent (p = 0.09). However, Ashkenazi Jews displayed a 1.9-fold higher frequency of variant 677T and a 1.8-fold lower frequency of variant 1298C compared to non-Ashkenazi Jews (p < 0.001). Distinct differences in the relative frequencies of both polymorphisms were also found between Ashkenazi Jews and Druze (p < 0.01 for C677T, p < 0.01 for A1298C) or Ashkenazi Jews and Arab Moslem (p < 0.01 for C677T, p < 0.05 for A1298C). These data underscore the importance of geographic genetic analysis for a better understanding of human pharmacotherapy and personalized medicine.

  14. Alteration of the alkaloid profile in genetically modified tobacco reveals a role of methylenetetrahydrofolate reductase in nicotine N-demethylation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of the tetrahydrofolate (THF)-mediated one-carbon (C1) metabolic network. This enzyme catalyzes reduction of 5,10-methylene-THF to 5-methyl-THF. The latter donates its methyl group to homocysteine forming Met, which is then used for the syn...

  15. [Posterior-predominant leukoencephalopathy which was caused by methylenetetrahydrofolate reductase deficiency and successfully treated with folic acid].

    PubMed

    Tamura, Asako; Sasaki, Ryogen; Kagawa, Ken; Nakatani, Kaname; Osaka, Hitoshi; Tomimoto, Hidekazu

    2014-01-01

    A 35-year-old woman was admitted with subacute intellectual deterioration. Laboratory studies showed elevated total homocysteine and decreased folic acid. MRI revealed leukoencephalopathy with a posterior predominance, and hyperintensity in the pyramidal tracts on T2-weighted and FLAIR images. The enzyme assay showed a deficiency of methylenetetrahydrofolate reductase (MTHFR) activity with low residual activity of 4.2% of the mean control value in cultured fibroblasts. Sequence analysis of the MTHFR gene demonstrated two homozygous missense mutations, c.677C>T (p.Ala222Val) and c.685A>C (p.Ile225Leu). c.677C>T (p.Ala222Val) is known as a common polymorphism and c.685A>C (p.Ile225Leu) is considered to be a novel polymorphism. A diagnosis of MTHFR deficiency was made. Treatment with folic acid, vitamin B12 and B6 made significant improvement of intellectual deterioration and reduction in the total homocysteine level. They also made marked resolution of leukoencephalopathy. Posterior-predominant leukoencephalopathy was found to be an excellent marker of MTHFR deficiency, and may help to establish the diagnosis.

  16. Methylenetetrahydrofolate Reductase 677TT Genotype may be Associated with an Increased Lung Cancer Risk in North China: An Updated Meta

    PubMed Central

    Liu, Nan-Bo; Li, Jun; Qi, Jia-Feng; Zhang, Zhen-Zhong; Wu, Xu; Zhang, Jun-Hua

    2014-01-01

    Background Although many epidemiology studies have investigated the methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and their associations with lung cancer (LC), definite conclusions cannot be drawn. To clarify the effects of MTHFR polymorphisms on the risk of LC, we performed a meta-analysis in Chinese populations. Material/Methods Related studies were identified from PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure (CNKI), and Chinese Biology Medicine (CBM) until 16 February 2014. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. Results A total of 11 studies with 2487 LC cases and 3228 controls were included in this meta-analysis. Overall, no significant association was found between MTHFR C677T polymorphism and LC risk when all studies in Chinese populations were pooled into this meta-analysis. In subgroup analyses stratified by geographical location and source of controls, significantly increased risk was found in North China (T vs. C: OR=1.28, 95% CI: 1.14–1.44; TT vs. CC: OR=1.67, 95% CI: 1.33–2.10; TT + CT vs. CC, OR=1.39, 95% CI=1.15–1.69; TT vs. CC + CT: OR=1.46, 95% CI: 1.03–2.06) and in population-based studies (TT vs. CC: OR=1.37, 95% CI: 1.14–1.65; TT vs. CC + CT: OR=1.25, 95% CI: 1.07–1.45). Conclusions This meta-analysis provides evidence that MTHFR C677T polymorphism may contribute to LC development in North China. Studies with larger sample sizes and wider spectrum of populations are warranted to verify this finding. PMID:25544260

  17. Combined choroidal neovascularization and hypopituitarism in a patient with homozygous mutation in methylenetetrahydrofolate reductase gene

    PubMed Central

    Aydogdu, Aydogan; Haymana, Cem; Baskoy, Kamil; Durukan, Ali H.; Ozgur, Gokhan; Azal, Omer

    2014-01-01

    We report a case of choroidal neovascularization (CNV) secondary to methylenetetrahydrofolate reductase (MTHFR) gene mutation in a 20-year-old male patient with hypopituitarism. Treatment with three consecutive injections of intravitreal ranibizumab (anti-vascular endothelial growth factor) resulted in significant improvement of the patient's vision and the appearance of the macula. A search of the literature produced no previously reported case of MTHFR gene mutation associated both CNV and possibly hypopituitarism. With hormone replacement therapy of hypopituitarism, acetyl salicylic acid 100 mg/day also was started. The patient was clinically stable both for CNV and other thromboembolic disorders over a 6-month follow-up and also 1-year follow-up period. PMID:24672570

  18. Effect of multivitamins on plasma homocysteine in patients with the 5,10 methylenetetrahydrofolate reductase C677T homozygous state.

    PubMed

    Dell'edera, Domenico; Tinelli, Andrea; Milazzo, Giusi Natalia; Malvasi, Antonio; Domenico, Carone; Pacella, Elena; Pierluigi, Compagnoni; Giuseppe, Tarantino; Marcello, Guido; Francesco, Lomurno; Epifania, Annunziata Anna

    2013-08-01

    The role of hyperhomocysteinemia (HHcy) as a cardiovascular risk factor remains a matter of debate, while it correlates with folates, it demonstrates inverse correlation with plasma homocysteine (Hcy) levels and vitamin B12 levels and reduces plasma Hcy levels following supplementation with multivitamins. The purpose of this study was to demonstrate that administering multivitamins at specific doses for 90 days restores normal plasma Hcy levels in women who are homozygous for the thermolabile variant of 5,10 methylenetetrahydrofolate reductase (MTHFR C677T). We enrolled 106 healthy females aged between 30 and 42 years, who were non-smokers, non-vegetarian, normotensive and who had no history of food abuse in the previous months. Only females were enrolled in order to rule out any bias due to the variation in Hcy plasma concentrations between males and females. Patient blood sampling was performed in order to determine plasma Hcy, serum folic acid and vitamin B12 levels. Furthermore, molecular characterization of the C677T polymorphism present in the MTHFR gene, was also performed. The results of this study demonstrated that supplementation with specific multivitamins restores normal plasma Hcy levels, regardless of the MTHFR genotype. Furthermore, it is unnecessary to adminster high doses of folate to reduce plasma Hcy levels, and administering high doses of folate may cause pro-inflammatory and pro-proliferative effects.

  19. Seven novel mutations at the 5,10-methylenetetrahydrofolate reductase locus

    SciTech Connect

    Goyette, P.; Frosst, P.; Rosenblatt, D.S.; Rozen, R.

    1994-09-01

    5,10-methylenetetrahydrofolate reductase (MTHFR), a flavoprotein, catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a cofactor for methionine synthase in the methylation of homocysteine to methionine. Severe MTHFR deficiency, which causes homocysteinemia, is an autosomal recessive disorder with variable clinical features; developmental delay, perinatal death, mental retardation and asymptomatic individuals have been observed. A milder deficiency has been reported in patients with cardiovascular disease. We have recently described the isolation of a cDNA for MTHFR and the identification of 2 mutations in patients with severe MTHFR deficiency. We report here the characterization of 7 additional mutations at this locus: 5 missense mutations and 2 splicing mutations. Mutation analysis was performed by SSCP on PCR products generated either from reverse transcription-PCR of patients` total fibroblast RNA or from PCR of patients` genomic DNA. The 5 missense mutations are as follows: 1 Arg to Cys substitution in a hydrophilic segment proposed to be the hinge region that connects the catalytic and regulatory domains, 2 different Arg to Cys substitutions in 2 patients whose enzymatic thermolability is responsive to FAD, 1 Thr to Met substitution affecting an evolutionarily-conserved residue and a Pro to Leu substitution. The 2 splicing mutations affect the 5{prime} splice site and the 3{prime} splice site of 2 introns, respectively. The 5{prime} splice site mutation generates a 57 bp in-frame deletion of the RNA through the utilization of a cryptic 5{prime} splice site within the coding sequence. The identification of 9 mutations at this locus has allowed us to make preliminary correlations between genotype and phenotype and to contribute to a structure:function analysis of the enzyme.

  20. Plasma folate, methylenetetrahydrofolate reductase (MTHFR), and colorectal cancer risk in three large nested case-control studies.

    PubMed

    Lee, Jung Eun; Wei, Esther K; Fuchs, Charles S; Hunter, David J; Lee, I-Min; Selhub, Jacob; Stampfer, Meir J; Willett, Walter C; Ma, Jing; Giovannucci, Edward

    2012-04-01

    Few prospective studies have examined the associations between blood levels of folate, in conjunction with methylenetetrahydrofolate reductase (MTHFR) polymorphisms, and colorectal cancer. We evaluated the associations between plasma folate, MTHFR C677T, and A1298C, and colorectal cancer in three large prospective studies: the Nurses' Health Study, the Health Professionals Follow-up Study, and the Physicians' Health Study. A total of 602 incident cases were identified and individually matched to controls who provided blood specimens. We used conditional logistic regression to calculate the relative risk (RR) and 95% confidence interval (95% CI) and then pooled the estimates using a random effects model. We found a lower risk of colorectal cancer among participants with low plasma folate levels: compared with the lowest quartile, RRs (95% CIs) for each successively higher quartile of plasma folate levels were 1.55 (1.14-2.11), 1.37 (1.00-1.88), and 1.47 (1.07-2.01; P for trend = 0.10). For the MTHFR polymorphisms, RRs (95% CIs) were 0.62 (0.44-0.90) for 677TT versus CC/CT and 0.68 (0.31-1.51) for 1298CC versus AC/AA, and these lower-risk genotypes were associated with lower circulating plasma folate levels. When we partitioned the variation in plasma folate levels, variation due to folate intake was not positively associated with colorectal cancer risk. We found that low plasma folate levels were associated with lower risk of colorectal cancer. The reasons underlying a lower risk of colorectal cancer with low plasma folate levels require elucidation because plasma folate levels can reflect dietary intake, genetic influences, and other factors.

  1. Prevention of brain disease from severe 5,10-methylenetetrahydrofolate reductase deficiency.

    PubMed

    Strauss, Kevin A; Morton, D Holmes; Puffenberger, Erik G; Hendrickson, Christine; Robinson, Donna L; Wagner, Conrad; Stabler, Sally P; Allen, Robert H; Chwatko, Grazyna; Jakubowski, Hieronim; Niculescu, Mihai D; Mudd, S Harvey

    2007-06-01

    Over a four-year period, we collected clinical and biochemical data from five Amish children who were homozygous for missense mutations in 5,10-methylenetetrahydrofolate reductase (MTHFR c.1129C>T). The four oldest patients had irreversible brain damage prior to diagnosis. The youngest child, diagnosed and started on betaine therapy as a newborn, is healthy at her present age of three years. We compared biochemical data among four groups: 16 control subjects, eight heterozygous parents, and five affected children (for the latter group, both before and during treatment with betaine anhydrous). Plasma amino acid concentrations were used to estimate changes in cerebral methionine uptake resulting from betaine therapy. In all affected children, treatment with betaine (534+/-222 mg/kg/day) increased plasma S-adenosylmethionine, improved markers of tissue methyltransferase activity, and resulted in a threefold increase of calculated brain methionine uptake. Betaine therapy did not normalize plasma total homocysteine, nor did it correct cerebral 5-methyltetrahydrofolate deficiency. We conclude that when the 5-methyltetrahydrofolate content of brain tissue is low, dietary betaine sufficient to increase brain methionine uptake may compensate for impaired cerebral methionine recycling. To effectively support the metabolic requirements of rapid brain growth, a large dose of betaine should be started early in life.

  2. The C677T mutation in the methylenetetrahydrofolate reductase gene among the Indonesian Javanese population.

    PubMed

    Sadewa, Ahmad Hamim; Sunarti; Sutomo, Retno; Hayashi, Chiyo; Lee, Myeong Jin; Ayaki, Hitoshi; Sofro, Abdul Salam M; Matsuo, Masafumi; Nishio, Hisahide

    2002-12-01

    The presence of the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene has been regarded as a genetic risk factor for coronary artery diseases and neural tube defects. Although the prevalence of this mutation has been reported from various ethnic populations, few data concerning Indonesian populations are available. We have investigated the frequency of the mutation in 68 Indonesian Javanese (residents of Java Island) and compared it with the data from 244 Japanese (residents of Honshu Island). The frequencies of the three genotypes in Javanese were C/C 0.84, C/T 0.16 and T/T 0.00, whereas those in Japanese were C/C 0.39, C/T 0.48 and T/T 0.13. The rarity of the T/T genotype in the Indonesian Javanese population may be due to malnutrition in pregnant women, because insufficient intake of folate is considered to be a survival disadvantage for fetuses with the T/T genotype. In conclusion, homozygosity for the C677T mutation in the MTHFR gene does not constitute a genetic risk factor for coronary artery diseases and neural tube defects in the Indonesian Javanese population.

  3. [Methylenetetrahydrofolate reductase deficiency-induced schizophrenia in a school-age boy].

    PubMed

    Wang, Qiao; Liu, Jing; Liu, Yu-Peng; Li, Xi-Yuan; Ma, Yan-Yan; Wu, Tong-Fei; Ding, Yuan; Song, Jin-Qing; Wang, Yu-Jie; Yang, Yan-Ling

    2014-01-01

    Methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare autosomal recessive disorder. It is known that MTHFR deficiency may result in hyperhomocysteinemia, but MTHFR deficiency-induced schizophrenia has been rarely reported. Here we present the clinical course, biochemical and genetic characteristics of schizophrenia resulted from MTHFR deficiency in a school-age boy. He was 13 years old. He was admitted with a two-year history of fear, auditory hallucination, learning difficulty, sleeping problems, irascibility, drowsing and giggling. At admission, he had significantly elevated plasma and urine levels of total homocysteine, significantly decreased levels of folate in serum and cerebrospinal fluid, and a normal blood concentration of methionine. Further DNA sequencing analysis showed 665C>T homozygous mutations in the MTHFR gene. The patient was diagnosed with MTHFR deficiency-associated schizophrenia and treatment with calcium folinate, vitamin B12, vitamin B6, and betaine was initiated. After the treatment for 1 week, his plasma and urine levels of homocysteine were decreased to a normal range and the clinical symptoms were significantly improved. After 3 months of treatment, the patient returned to school. He is now living with normal school life. In summary, children with late-onset MTHFR deficiency and secondary cerebral folate deficiency may lead to schizophrenia. This rare condition can be early diagnosed through analyses of blood and urine total homocysteine, amino acids in blood and folate in blood and cerebral fluid and successfully treated with folinic acid, vitamin B6, vitamin B12 and betaine.

  4. 5,10-Methylenetetrahydrofolate reductase deficiency with progressive polyneuropathy in an infant.

    PubMed

    Tsuji, Megumi; Takagi, Atsushi; Sameshima, Kiyoko; Iai, Mizue; Yamashita, Sumimasa; Shinbo, Hiroko; Furuya, Noritaka; Kurosawa, Kenji; Osaka, Hitoshi

    2011-06-01

    5,10-Methylenetetrahydrofolate reductase (MTHFR) deficiency is the most prevalent inborn error of folate metabolism, and has variable clinical manifestations from asymptomatic to severe psychomotor retardation, microcephalus and seizure. In untreated infantile cases, it predominantly affects the central nervous system, which is sometimes fatal. On the other hand, peripheral nerve involvement is uncommon. We present a severe infantile case of MTHFR deficiency that manifested unilateral phrenic nerve palsy with communicating hydrocephalus, developmental delay and died at 11months of age. An enzymatic study confirmed MTHFR deficiency with residual activity of 0.75% of mean control values in cultured fibroblasts. Mutation analysis of the MTHFR gene revealed homozygous, tandem missense mutations c.[446G>T; 447C>T] in exon 3 of the MTHFR gene converting glycine to valine (Gly149Val). In MTHFR deficiency, betaine may improve the symptoms if started immediately after birth by reducing the level of serum homocysteine and increasing that of methionine. Our results show that we should be aware of possible inborn errors of folate metabolism such as MTHFR deficiency, in infants with unexplained developmental delay manifesting rapidly progressive polyneuropathy.

  5. Gene-wide association study between the methylenetetrahydrofolate reductase gene (MTHFR) and schizophrenia in the Japanese population, with an updated meta-analysis on currently available data.

    PubMed

    Yoshimi, Akira; Aleksic, Branko; Kawamura, Yukiko; Takahashi, Nagahide; Yamada, Shinnosuke; Usui, Hinako; Saito, Shinichi; Ito, Yoshihito; Iwata, Nakao; Inada, Toshiya; Noda, Yukihiro; Yamada, Kiyofumi; Ozaki, Norio

    2010-12-01

    Methylenetetrahydrofolate reductase (MTHFR) is a critical molecule for single-carbon transfer reactions. Recent evidence suggests that polymorphisms of MTHFR are related to neural tube deficits and the pathogenesis of schizophrenia. While several studies have demonstrated associations between the gene encoding the MTHFR (MTHFR) polymorphisms and schizophrenia, these studies lack consistency. Therefore, we conducted a gene-wide association study (patients with schizophrenia = 696, control subjects = 747) and performed imputation analysis. Additionally, we performed meta-analysis on currently available data from 18 studies for two common functional polymorphisms (rs1801131 and rs1801133). There were no significant associations with schizophrenia in the single marker analysis for the seven tagging SNPs of MTHFR. In the haplotypic analysis, a nominally significant association was observed between the haplotypes, which included four SNPs (rs1801133, rs17421511, rs17037396, and rs9651118) and the schizophrenic patients. Additionally, the imputation analysis demonstrated there were several associated markers on the MTHFR chromosomal region. However, confirmatory analyses of three tagging SNPs (rs1801133, rs17037396, and rs9651118) and the top SNP (rs17421511) for the imputation results (patients with schizophrenia = 797, control subjects = 1025) failed to replicate the haplotypic analysis and the imputation results. These findings suggest that MTHFR polymorphisms are unlikely to be related to the development of schizophrenia in the Japanese population. However, since our meta-analysis results demonstrated strong support for association of rs1801133 with schizophrenia, further replication studies based on a gene-wide approach need to be considered.

  6. C677T methylenetetrahydrofolate reductase and plasma homocysteine levels among Thai vegans and omnivores.

    PubMed

    Kajanachumpol, Saowanee; Atamasirikul, Kalayanee; Tantibhedhyangkul, Phieuvit

    2013-01-01

    Hyperhomocysteinemia among vegetarians and vegans is caused mostly by vitamin B12 deficiency. A C-to-T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene results in a thermolabile MTHFR, which may affect homocysteine (Hcy) levels. The importance of this gene mutation among populations depends on the T allele frequency. Blood Hcy, vitamin B12, folate, vitamin B6, and MTHFR C677T mutation status were determined in 109 vegans and 86 omnivores aged 30 - 50 years. The vegans had significantly higher Hcy levels than the omnivores, geometric means (95 % CI) 19.2 (17.0 - 21.7) µmol/L vs. 8.53 (8.12 - 8.95) µmol/L, p < 0.001. A C-to-T mutation in the vegans increased plasma Hcy, albeit insignificantly; geometric means 18.2 µmol/L, 20.4 µmol/L, and 30.0 µmol/L respectively in CC, CT, and TT MTHFR genotypes. There was also a significant decrease in serum folate; geometric means 12.1 ng/mL, 9.33 ng/mL, and 7.20 ng/mL respectively, in the CC, CT, and TT mutants, p = 0.006, and particularly, in the TT mutant compared with the CC wild type, 7.20 ng/mL vs. 12.1 ng/mL, p = 0.023. These findings were not seen in the omnivores. It was concluded that hyperhomocysteinemia is prevalent among Thai vegans due to vitamin B12 deficiency. C-to-T MTHFR mutation contributes only modestly to the hyperhomocysteinemia.

  7. Molecular characterization of five patients with homocystinuria due to severe methylenetetrahydrofolate reductase deficiency.

    PubMed

    Urreizti, R; Moya-García, A A; Pino-Ángeles, A; Cozar, M; Langkilde, A; Fanhoe, U; Esteves, C; Arribas, J; Vilaseca, M A; Pérez-Dueñas, B; Pineda, M; González, V; Artuch, R; Baldellou, A; Vilarinho, L; Fowler, B; Ribes, A; Sánchez-Jiménez, F; Grinberg, D; Balcells, S

    2010-11-01

    Methylenetetrahydrofolate reductase (MTHFR) plays a major role in folate metabolism. Disturbed function of the enzyme results in hyperhomocysteinemia and causes severe vascular and neurological disorders and developmental delay. Five patients suspected of having non-classical homocystinuria due to MTHFR deficiency were examined with respect to their symptoms, MTHFR enzyme activity and genotypes of the MTHFR gene. All patients presented symptoms of severe central nervous system disease. Two patients died, at the ages of 15 months and 14 years. One patient is currently 32 years old, and is being treated with betaine and folinic acid. The other two patients, with an early diagnosis and a severe course of the disease, are currently improving under treatment. MTHFR enzyme activity in the fibroblasts of four of the patients was practically undetectable. We found four novel mutations, three of which were missense changes c.664G> T (p.V218L), c.1316T> C (p.F435S) and c.1733T> G (p.V574G), and the fourth was the 1-bp deletion c.1780delC (p.L590CfsX72). We also found the previously reported nonsense mutation c.1420G> T (p.E470X). All the patients were homozygous. Molecular modelling of the double mutant allele (p.V218L; p.A222V) revealed that affinity for FAD was not affected in this mutant. For the p.E470X mutation, the evidence pointed to nonsense-mediated mRNA decay. In general, genotype-phenotype analysis predicts milder outcomes for patients with missense changes than for those in which mutations led to severe alterations of the MTHFR protein.

  8. Genotype prevalence and allele frequencies of 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T mutation in two caste groups of India.

    PubMed

    Rai, V; Yadav, U; Kumar, P

    2012-06-15

    The aim of the present study was to investigate the distribution of 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphism in two caste group populations of eastern Uttar Pradesh. This mutation has been suggested to be positively associated with the risk of several congenital and multifactorial disorders. Frequency of mutant T allele differs in various ethnic and geographical populations of the world. MTHFR C677T mutation analysis was carried out by PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) method and the samples studied were randomly selected from the healthy individuals belonging to two caste populations. In Brahmin samples, genotype frequencies of CC, CT and TT were 0.727, 0.25 and 0.023 respectively whereas in Rajput samples, CC genotype was observed in 88 samples, CT genotype in 25 and TT genotype was found in 2 samples. Frequency of mutant T allele was found to be 0.147 in Brahmin and 0.126 in Rajput populations. The percentage of CT genotype and C allele were high in both the populations.

  9. Insights into severe 5,10-methylenetetrahydrofolate reductase deficiency: molecular genetic and enzymatic characterization of 76 patients.

    PubMed

    Burda, Patricie; Schäfer, Alexandra; Suormala, Terttu; Rummel, Till; Bürer, Céline; Heuberger, Dorothea; Frapolli, Michele; Giunta, Cecilia; Sokolová, Jitka; Vlášková, Hana; Kožich, Viktor; Koch, Hans Georg; Fowler, Brian; Froese, D Sean; Baumgartner, Matthias R

    2015-06-01

    5,10-Methylenetetrahydrofolate reductase (MTHFR) deficiency is the most common inherited disorder of folate metabolism and causes severe hyperhomocysteinaemia. To better understand the relationship between mutation and function, we performed molecular genetic analysis of 76 MTHFR deficient patients, followed by extensive enzymatic characterization of fibroblasts from 72 of these. A deleterious mutation was detected on each of the 152 patient alleles, with one allele harboring two mutations. Sixty five different mutations (42 novel) were detected, including a common splicing mutation (c.1542G>A) found in 21 alleles. Using an enzyme assay in the physiological direction, we found residual activity (1.7%-42% of control) in 42 cell lines, of which 28 showed reduced affinity for nicotinamide adenine dinucleotide phosphate (NADPH), one reduced affinity for methylenetetrahydrofolate, five flavin adenine dinucleotide-responsiveness, and 24 abnormal kinetics of S-adenosylmethionine inhibition. Missense mutations causing virtually absent activity were found exclusively in the N-terminal catalytic domain, whereas missense mutations in the C-terminal regulatory domain caused decreased NADPH binding and disturbed inhibition by S-adenosylmethionine. Characterization of patients in this way provides a basis for improved diagnosis using expanded enzymatic criteria, increases understanding of the molecular basis of MTHFR dysfunction, and points to the possible role of cofactor or substrate in the treatment of patients with specific mutations.

  10. Acute renal infarction associated with homozygous methylenetetrahydrofolate reductase mutation C677T and IgA beta-2-glycoprotein antibodies.

    PubMed

    Vlachostergios, Panagiotis J; Dufresne, François

    2015-07-01

    Arterial thrombosis of the kidney(s) is a rare clinical entity usually presenting as a result of cardioembolic disease, though rare inherited hypercoagulable states have also been implicated. Within this context, both hyperhomocysteinemia triggered by a mutated methylenetetrahydrofolate reductase (MTHFR) gene product and the presence of antiphospholipid antibodies have been separately associated with arterial thrombotic events, including renal artery embolism. We present a case of combined homozygous MTHFR C677T mutation and IgA beta-2-glycoprotein antibody positivity resulting in acute renal infarction and previous silent myocardial infarction. An acute and otherwise unexplained thrombotic event of unusual location always warrants further investigation, which should include testing for hereditary thrombophilic disorders.

  11. Mutations in cystathionine beta-synthase or methylenetetrahydrofolate reductase gene increase N-homocysteinylated protein levels in humans.

    PubMed

    Jakubowski, Hieronim; Boers, Godfried H J; Strauss, Kevin A

    2008-12-01

    Severely elevated plasma homocysteine (Hcy) levels observed in genetic disorders of Hcy metabolism are associated with pathologies in multiple organs and lead to premature death due to vascular complications. In addition to elevating plasma Hcy, mutations in cystathionine beta-synthase (CBS) or methylenetetrahydrofolate reductase (MTHFR) gene lead to markedly elevated levels of circulating Hcy-thiolactone. The thiooester chemistry of Hcy-thiolactone underlies its ability to form isopeptide bonds with protein lysine residues (N-Hcy-protein), which may impair or alter the protein's function. However, it was not known whether genetic deficiencies in Hcy metabolism affect N-Hcy-protein levels in humans. Here we show that plasma N-Hcy-protein levels are significantly elevated in CBS- and MTHFR-deficient patients. We also show that CBS-deficient patients have significantly elevated plasma levels of prothrombotic N-Hcy-fibrinogen. These results provide a possible explanation for increased atherothrombosis observed in CBS-deficient patients.

  12. Methylenetetrahydrofolate reductase gene germ-line C677T and A1298C SNPs are associated with colorectal cancer risk in the Turkish population.

    PubMed

    Ozen, Filiz; Sen, Metin; Ozdemir, Ozturk

    2014-01-01

    Colorectal cancer (CRC) is the third most common cause of death due to cancer in the worldwide and the incidence is also increasing in Turkey. Our present aim was to investigate any association between germ-line methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and CRC risk in Turkey. A total of 86 CRC cases and 212 control individuals of the same ethnicity were included in the current study. Peripheral blood-DNA samples were used for genotyping by StripAssay technique, based on the reverse- hybridization principle and real-time PCR methods. Results were compared in Pearson Chi-square and multiple logistic regression models. The MTHFR 677TT (homozygous) genotype was found in 20.9% and the T allele frequency 4.2-fold increased in CRC when compared with the control group.The second SNP MTHFR 1298CC (homozygous) genotype was found in 14.0% and the C allele frequency 1.4-fold elevated in the CRC group. The current data suggest strong associations between both SNPs of germ-line MTHFR 677 C>T and 1298 A>C genotypes and CRC susceptibility in the Turkish population. Now the results need to be confirmed with a larger sample size.

  13. Methylenetetrahydrofolate reductase (MTHFR) genetic variation and major depressive disorder prognosis: A five-year prospective cohort study of primary care attendees.

    PubMed

    Bousman, Chad A; Potiriadis, Maria; Everall, Ian P; Gunn, Jane M

    2014-01-01

    Methylenetetrahydrofolate reductase (MTHFR) genetic variation has been associated with the diagnosis of major depressive disorder (MDD) but no study to date has examined the effect MTHFR variation has on MDD prognosis. We sought to examine the prospective effects of two common MTHFR variants (C677T and A1298C) as well as seven haplotype-tagging single nucleotide polymorphisms (htSNPs) on MDD prognosis over a 5-year (60-month) period. Participants were 147 depressed primary care attendees enrolled in the Diagnosis, Management and Outcomes of Depression in Primary Care (diamond) prospective cohort study. Prognosis of MDD was measured using three methods: (1) DSM-IV criteria, (2) Primary Care Evaluation of Mental Disorders Patient Health Questionnaire-9 (PHQ-9), and (3) Center for Epidemiologic Studies Depression Scale (CESD). DSM-IV criteria for MDD was assessed using the Composite International Diagnostic Interview at baseline and 24, 36, 48, and 60 months post-baseline; whereas, PHQ-9 and CESD measures were employed at baseline and 12, 24, 36, 48, and 60 months post-baseline. Repeated measures analysis of variance showed that PHQ-9 symptom severity trajectories differed by C677T genotype (F = 3.34, df = 2,144, P = 0.038), with 677CC genotype showing the most severe symptom severity course over the 60 months of observation. Neither the A1298C polymorphism nor any of the htSNPs were associated with MDD prognosis regardless of measure used. Our results suggest that the MTHFR C677T polymorphism may serve as a marker for MDD prognosis pending independent replication.

  14. Meta-analysis of Methylenetetrahydrofolate reductase maternal gene in Down syndrome: increased susceptibility in women carriers of the MTHFR 677T allele.

    PubMed

    Victorino, D B; Godoy, M F; Goloni-Bertollo, E M; Pavarino, E C

    2014-08-01

    Because a number of data studies include some controversial results about Methylenetetrahydrofolate reductase (MTHFR) polymorphisms and Down syndrome (DS), we performed a meta-analysis to determine a more precise estimation of this association. Studies were searched on PubMed, EMBASE and Lilacs-Scielo, up to April 2013, and they were eligible if they included case mothers (DSM) that have gave birth to children with DS, and controls mothers (CM) that have gave birth to healthy children without chromosomal abnormality, syndrome or malformation. The combined odds ratio with 95% confidence intervals was calculated by fixed or random effects models to assess the strength of associations. Potential sources of heterogeneity between studies were evaluated using Q test and the I(2). Publication bias was estimated using Begg's test and Egger's linear regression test. Sensitivity analyses were performed by using allelic, dominant, recessive and codominant genetic models, Hardy-Weinberg equilibrium (HWE) and ethnicity. Twenty-two studies with 2,223 DSM and 2,807 CM were included for MTHFR C677T and 15 studies with 1,601 DSM and 1,849 CM were included for MTHFR A1298C. Overall analysis suggests an association of the MTHFR C677T polymorphism with maternal risk for DS. Moreover, no association between the MTHFR A1298C polymorphism and maternal risk for DS was found. There is also evidence of higher heterogeneity, with I(2) test values ranging from 8 to 89%. No evidence of publication bias was found. Taken together, our meta-analysis implied that the T allele carriers might carry an increased maternal risk for DS.

  15. Life-threatening methylenetetrahydrofolate reductase (MTHFR) deficiency with extremely early onset: characterization of two novel mutations in compound heterozygous patients.

    PubMed

    Forges, Thierry; Chery, Céline; Audonnet, Sandra; Feillet, François; Gueant, Jean-Louis

    2010-06-01

    Methylenetetrahydrofolate reductase (MTHFR) is a key enzymatic component of the folate cycle, converting 5,10-methylenetetrahydrofolate into 5-methyltetrahydrofolate, the methyl donor for remethylation of homocysteine into methionine. Severe MTHFR deficiency is a rare recessive disease leading to major hyperhomocysteinemia, homocystinuria, and progressive neurological distress within the two first decades of life. More than 50 mutations have been reported so far in affected patients but only a few cases with very early onset of symptoms during the first weeks have been described, most of them showing a particular severe clinical course. We detected two novel mutations by direct sequencing of MTHFR in compound heterozygous patients with extremely low or undetectable enzyme activity; one of them had clinical onset during the first week of life and fatal issue at the age of six weeks. Prenatal diagnosis of his sibling allowed for early treatment with B vitamins and betaine and a favorable outcome. One of these mutations (c.523G>A) led to an Ala>Thr transition in the catalytic domain of the enzyme, the other (c.1166G>A) induced alternative splicing of exon 7 at the junction of the catalytic and regulatory domains. Both parents carried only one of these mutations and presented with moderate and intermediate hyperhomocysteinemia, respectively, without neurological symptoms. Severe MTHFR deficiency thus has to be taken into consideration when investigating neurological distress even in the newborn, regarding the need for an earliest possible treatment. Characterization of the relatives further allows for preventive measure to limit the risks of chronic hyperhomocysteinemia.

  16. The maize brown midrib2 (bm2) gene encodes a methylenetetrahydrofolate reductase that contributes to lignin accumulation.

    PubMed

    Tang, Ho Man; Liu, Sanzhen; Hill-Skinner, Sarah; Wu, Wei; Reed, Danielle; Yeh, Cheng-Ting; Nettleton, Dan; Schnable, Patrick S

    2014-02-01

    The midribs of maize brown midrib (bm) mutants exhibit a reddish-brown color associated with reductions in lignin concentration and alterations in lignin composition. Here, we report the mapping, cloning, and functional and biochemical analyses of the bm2 gene. The bm2 gene was mapped to a small region of chromosome 1 that contains a putative methylenetetrahydrofolate reductase (MTHFR) gene, which is down-regulated in bm2 mutant plants. Analyses of multiple Mu-induced bm2-Mu mutant alleles confirmed that this constitutively expressed gene is bm2. Yeast complementation experiments and a previously published biochemical characterization show that the bm2 gene encodes a functional MTHFR. Quantitative RT-PCR analyses demonstrated that the bm2 mutants accumulate substantially reduced levels of bm2 transcript. Alteration of MTHFR function is expected to influence accumulation of the methyl donor S-adenosyl-L-methionine (SAM). Because SAM is consumed by two methyltransferases in the lignin pathway (Ye et al., ), the finding that bm2 encodes a functional MTHFR is consistent with its lignin phenotype. Consistent with this functional assignment of bm2, the expression patterns of genes in a variety of SAM-dependent or -related pathways, including lignin biosynthesis, are altered in the bm2 mutant. Biochemical assays confirmed that bm2 mutants accumulate reduced levels of lignin with altered composition compared to wild-type. Hence, this study demonstrates a role for MTHFR in lignin biosynthesis.

  17. Mutations in methylenetetrahydrofolate reductase and in cysthationine beta synthase: is there a link to homocysteine levels in peripheral arterial disease?

    PubMed

    Santos, Maria E R C; das C L E Silva, Francisco; Gomes, Karina B; Fernandes, Ana Paula M; Freitas, Fernanda R; Faria, Mayara C; Mota, Ana Paula L; Carvalho, Maria G

    2011-06-01

    Peripheral arterial disease (PAD) is an atherosclerotic disturbance characterized by a progressive obstruction of lower limb arteries. Many risk factors associated with PAD development have being reported in the literature. The present study aimed to investigate whether mutations in the methylenetetrahydrofolate reductase (MTHFR) or in the cystathionine beta synthase (CBS) genes are associated with higher levels of homocysteine and the risk of PAD in patients from Brazil. This study analyzed 39 patients with PAD and 32 without PAD in whom risk factors and C677T mutations in the MTHFR gene and both 844ins68 and T833C mutations in the CBS gene were investigated. Although higher levels of homocysteine could be observed in patients with PAD compared to controls, no association between the increase of homocysteine and the frequency of C677T, 844ins68, and T833C mutations could be observed. The results suggest that these mutations do not appear to be related to either homocysteine levels or the development of the disease. However, hyperhomocysteinemia and smoking are important factors in PAD development.

  18. The MET13 methylenetetrahydrofolate reductase gene is essential for infection-related morphogenesis in the rice blast fungus Magnaporthe oryzae.

    PubMed

    Yan, Xia; Que, Yawei; Wang, Hong; Wang, Congcong; Li, Ya; Yue, Xiaofeng; Ma, Zhonghua; Talbot, Nicholas J; Wang, Zhengyi

    2013-01-01

    Methylenetetrahydrofolate reductases (MTHFRs) play a key role in the biosynthesis of methionine in both prokaryotic and eukaryotic organisms. In this study, we report the identification of a novel T-DNA-tagged mutant WH672 in the rice blast fungus Magnaporthe oryzae, which was defective in vegetative growth, conidiation and pathogenicity. Analysis of the mutation confirmed a single T-DNA insertion upstream of MET13, which encodes a 626-amino-acid protein encoding a MTHFR. Targeted gene deletion of MET13 resulted in mutants that were non-pathogenic and significantly impaired in aerial growth and melanin pigmentation. All phenotypes associated with Δmet13 mutants could be overcome by addition of exogenous methionine. The M. oryzae genome contains a second predicted MTHFR-encoding gene, MET12. The deduced amino acid sequences of Met13 and Met12 share 32% identity. Interestingly, Δmet12 mutants produced significantly less conidia compared with the isogenic wild-type strain and grew very poorly in the absence of methionine, but were fully pathogenic. Deletion of both genes resulted in Δmet13Δmet12 mutants that showed similar phenotypes to single Δmet13 mutants. Taken together, we conclude that the MTHFR gene, MET13, is essential for infection-related morphogenesis by the rice blast fungus M. oryzae.

  19. Positional cloning in Cryptococcus neoformans and its application for identification and cloning of the gene encoding methylenetetrahydrofolate reductase.

    PubMed

    Toh-E, Akio; Ohkusu, Misako; Shimizu, Kiminori; Kawamoto, Susumu

    2015-03-01

    Cryptococcus neoformans, a basidiomycetous human pathogenic yeast, has been widely used in research fields in medical mycology as well as basic biology. Gene cloning or identification of the gene responsible for a mutation of interest is a key step for functional analysis of a particular gene. The availability therefore, of the multiple methods for cloning is desirable. In this study, we proposed a method for a mapping-based gene identification/cloning (positional cloning) method in C. neoformans. To this end, we constructed a series of tester strains, one of whose chromosomes was labeled with the URA5 gene. A heterozygous diploid constructed by crossing one of the tester strains to a mutant strain of interest loses a chromosome(s) spontaneously, which is the basis for assigning a recessive mutant gene to a particular chromosome in the mitotic mapping method. Once the gene of interest is mapped to one of the 14 chromosomes, classical genetic crosses can then be performed to determine its more precise location. The positional information thus obtained can then be used to significantly narrow down candidate genes by referring to the Cryptococcus genome database. Each candidate gene is then examined whether it would complement the mutation. We successfully applied this method to identify CNA07390 encoding methylenetetrahydrofolate reductase as the gene responsible for a methionine-requiring mutant in our mutant collection.

  20. The MET13 Methylenetetrahydrofolate Reductase Gene Is Essential for Infection-Related Morphogenesis in the Rice Blast Fungus Magnaporthe oryzae

    PubMed Central

    Wang, Hong; Wang, Congcong; Li, Ya; Yue, Xiaofeng; Ma, Zhonghua; Talbot, Nicholas J.; Wang, Zhengyi

    2013-01-01

    Methylenetetrahydrofolate reductases (MTHFRs) play a key role in the biosynthesis of methionine in both prokaryotic and eukaryotic organisms. In this study, we report the identification of a novel T-DNA-tagged mutant WH672 in the rice blast fungus Magnaporthe oryzae, which was defective in vegetative growth, conidiation and pathogenicity. Analysis of the mutation confirmed a single T-DNA insertion upstream of MET13, which encodes a 626-amino-acid protein encoding a MTHFR. Targeted gene deletion of MET13 resulted in mutants that were non-pathogenic and significantly impaired in aerial growth and melanin pigmentation. All phenotypes associated with Δmet13 mutants could be overcome by addition of exogenous methionine. The M. oryzae genome contains a second predicted MTHFR-encoding gene, MET12. The deduced amino acid sequences of Met13 and Met12 share 32% identity. Interestingly, Δmet12 mutants produced significantly less conidia compared with the isogenic wild-type strain and grew very poorly in the absence of methionine, but were fully pathogenic. Deletion of both genes resulted in Δmet13Δmet12 mutants that showed similar phenotypes to single Δmet13 mutants. Taken together, we conclude that the MTHFR gene, MET13, is essential for infection-related morphogenesis by the rice blast fungus M. oryzae. PMID:24116181

  1. Altered protein phosphatase 2A methylation and Tau phosphorylation in the young and aged brain of methylenetetrahydrofolate reductase (MTHFR) deficient mice

    PubMed Central

    Sontag, Jean-Marie; Wasek, Brandi; Taleski, Goce; Smith, Josephine; Arning, Erland; Sontag, Estelle; Bottiglieri, Teodoro

    2014-01-01

    Common functional polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene, a key enzyme in folate and homocysteine metabolism, influence risk for a variety of complex disorders, including developmental, vascular, and neurological diseases. MTHFR deficiency is associated with elevation of homocysteine levels and alterations in the methylation cycle. Here, using young and aged Mthfr knockout mouse models, we show that mild MTHFR deficiency can lead to brain-region specific impairment of the methylation of Ser/Thr protein phosphatase 2A (PP2A). Relative to wild-type controls, decreased expression levels of PP2A and leucine carboxyl methyltransferase (LCMT1) were primarily observed in the hippocampus and cerebellum, and to a lesser extent in the cortex of young null Mthfr−/− and aged heterozygous Mthfr+/− mice. A marked down regulation of LCMT1 correlated with the loss of PP2A/Bα holoenzymes. Dietary folate deficiency significantly decreased LCMT1, methylated PP2A and PP2A/Bα levels in all brain regions examined from aged Mthfr+/+ mice, and further exacerbated the regional effects of MTHFR deficiency in aged Mthfr+/− mice. In turn, the down regulation of PP2A/Bα was associated with enhanced phosphorylation of Tau, a neuropathological hallmark of Alzheimer’s disease (AD). Our findings identify hypomethylation of PP2A enzymes, which are major CNS phosphatases, as a novel mechanism by which MTHFR deficiency and Mthfr gene-diet interactions could lead to disruption of neuronal homeostasis, and increase the risk for a variety of neuropsychiatric disorders, including age-related diseases like sporadic AD. PMID:25202269

  2. The prevalence of methylenetetrahydrofolate reductase 677 C-T, factor V 1691 G-A, and prothrombin 20210 G-A mutations in healthy populations in Setif, Algeria.

    PubMed

    Bourouba, Romyla; Houcher, Bakhouche; Djabi, Farida; Egin, Yonca; Akar, Nejat

    2009-10-01

    The polymorphic mutation 677 C-T in the methylenetetrahydrofolate reductase (MTHFR) gene presents a heterogeneous worldwide distribution and is associated with different disorders such as cardiovascular disease. Its frequency shows great ethnic and geographic variations. The aim of this work is to determine the frequency of MTHFR 677 C-T and coexistence of MTHFR 677 C-T with 2 other common, hereditary thrombophilia causes-namely, factor V 1691 G-A and prothrombin (PT) 20210 G-A mutation-in the Sétif region of Algeria. The study involved 147 apparently healthy participants (82 men and 65 women). Genotyping was carried out by a real-time polymerase chain reaction. The MTHFR 677T carrier frequency was found to be 54.4% (80/147); 59 individuals were heterozygous (40.1%), and 21 were homozygous (14.3%). The frequency of MTHFR 677T was found to be 34.3%. Among the 147 individuals, 3 (2.0%) had factor V Leiden, and 5 (3.4%) had PT 20210 A mutation. Of the 80 participants with MTHFR 677T mutation, 2 had heterozygote factor V 1691 G-A gene mutation, and 4 had heterozygote PT 20210 G-A gene mutation. The results showed that MTHFR 677T prevalence is quite high: an allelic frequency of 34.3% with a genotype frequency of 14.3%. Factor V 1691 G-A and PT 20210 G-A gene mutations are rare in the healthy population of the Sétif region of Algeria.

  3. Individual and Joint Associations of Methylenetetrahydrofolate Reductase C677T Genotype and Plasma Homocysteine With Dyslipidemia in a Chinese Population With Hypertension.

    PubMed

    Liu, Yanhong; Li, Kang; Venners, Scott A; Hsu, Yi-Hsiang; Jiang, Shanqun; Weinstock, Justin; Wang, Binyan; Tang, Genfu; Xu, Xiping

    2017-04-01

    We aimed to examine the cross-sectional associations of plasma total homocysteine (tHcy) concentrations and methylenetetrahydrofolate reductase ( MTHFR) C677T genotype with dyslipidemia. A total of 231 patients with mild-to-moderate essential hypertension were enrolled from the Huoqiu and Yuexi communities in Anhui Province, China. Plasma tHcy levels were measured by high-performance liquid chromatography. Genotyping was performed by TaqMan allelic discrimination technique. Compared with MTHFR 677 CC + CT genotype carriers, TT genotype carriers had higher odds of hypercholesterolemia (adjusted odds ratio [OR] [95% confidence interval (CI)]: 2.7 [1.4-5.2]; P = .004) and higher odds of abnormal low-density lipoprotein cholesterol (adjusted OR [95% CI]: 2.3 [1.1-4.8]; P = .030). The individuals with the TT genotype had higher concentrations of log(tHcy) than those with the 677 CC + CT genotype (adjusted β [standard error]: .2 [0.03]; P < .001). Patients with tHcy ≥ 10 μmol/L had significantly higher odds of hypercholesterolemia (adjusted OR [95% CI]: 2.4 [1.2-4.7]; P = .010). Furthermore, patients with both the TT genotype and the tHcy ≥ 10 μmol/L had the highest odds of hypercholesterolemia (adjusted OR [95% CI]: 4.1 [1.8-9.4]; P = .001) and low-density lipoprotein cholesterol (adjusted OR [95% CI]: 2.4 [1.0-6.0]; P = .064). This study suggests that both tHcy and the MTHFR C677T gene polymorphism may be important determinants of the incidence of dyslipidemia in Chinese patients with essential hypertension. Further studies are needed to confirm the role of tHcy and the MTHFR C677T mutation in the development of dyslipidemia in a larger sample.

  4. A common mutation in the 5,10-methylenetetrahydrofolate reductase gene affects genomic DNA methylation through an interaction with folate status

    PubMed Central

    Friso, Simonetta; Choi, Sang-Woon; Girelli, Domenico; Mason, Joel B.; Dolnikowski, Gregory G.; Bagley, Pamela J.; Olivieri, Oliviero; Jacques, Paul F.; Rosenberg, Irwin H.; Corrocher, Roberto; Selhub, Jacob

    2002-01-01

    DNA methylation, an essential epigenetic feature of DNA that modulates gene expression and genomic integrity, is catalyzed by methyltransferases that use the universal methyl donor S-adenosyl-l-methionine. Methylenetetrahydrofolate reductase (MTHFR) catalyzes the synthesis of 5-methyltetrahydrofolate (5-methylTHF), the methyl donor for synthesis of methionine from homocysteine and precursor of S-adenosyl-l-methionine. In the present study we sought to determine the effect of folate status on genomic DNA methylation with an emphasis on the interaction with the common C677T mutation in the MTHFR gene. A liquid chromatography/MS method for the analysis of nucleotide bases was used to assess genomic DNA methylation in peripheral blood mononuclear cell DNA from 105 subjects homozygous for this mutation (T/T) and 187 homozygous for the wild-type (C/C) MTHFR genotype. The results show that genomic DNA methylation directly correlates with folate status and inversely with plasma homocysteine (tHcy) levels (P < 0.01). T/T genotypes had a diminished level of DNA methylation compared with those with the C/C wild-type (32.23 vs.62.24 ng 5-methylcytosine/μg DNA, P < 0.0001). When analyzed according to folate status, however, only the T/T subjects with low levels of folate accounted for the diminished DNA methylation (P < 0.0001). Moreover, in T/T subjects DNA methylation status correlated with the methylated proportion of red blood cell folate and was inversely related to the formylated proportion of red blood cell folates (P < 0.03) that is known to be solely represented in those individuals. These results indicate that the MTHFR C677T polymorphism influences DNA methylation status through an interaction with folate status. PMID:11929966

  5. Methylenetetrahydrofolate Reductase Activity Is Involved in the Plasma Membrane Redox System Required for Pigment Biosynthesis in Filamentous Fungi ▿ †

    PubMed Central

    Frandsen, Rasmus J. N.; Albertsen, Klaus Selk; Stougaard, Peter; Sørensen, Jens L.; Nielsen, Kristian F.; Olsson, Stefan; Giese, Henriette

    2010-01-01

    Methylenetetrahydrofolate reductases (MTHFRs) play a key role in biosynthesis of methionine and S-adenosyl-l-methionine (SAM) via the recharging methionine biosynthetic pathway. Analysis of 32 complete fungal genomes showed that fungi were unique among eukaryotes by having two MTHFRs, MET12 and MET13. The MET12 type contained an additional conserved sequence motif compared to the sequences of MET13 and MTHFRs from other eukaryotes and bacteria. Targeted gene replacement of either of the two MTHFR encoding genes in Fusarium graminearum showed that they were essential for survival but could be rescued by exogenous methionine. The F. graminearum strain with a mutation of MET12 (FgΔMET12) displayed a delay in the production of the mycelium pigment aurofusarin and instead accumulated nor-rubrofusarin and rubrofusarin. High methionine concentrations or prolonged incubation eventually led to production of aurofusarin in the MET12 mutant. This suggested that the chemotype was caused by a lack of SAM units for the methylation of nor-rubrofusarin to yield rubrofusarin, thereby imposing a rate-limiting step in aurofusarin biosynthesis. The FgΔMET13 mutant, however, remained aurofusarin deficient at all tested methionine concentrations and instead accumulated nor-rubrofusarin and rubrofusarin. Analysis of MET13 mutants in F. graminearum and Aspergillus nidulans showed that both lacked extracellular reduction potential and were unable to complete mycelium pigment biosynthesis. These results are the first to show that MET13, in addition to its function in methionine biosynthesis, is required for the generation of the extracellular reduction potential necessary for pigment production in filamentous fungi. PMID:20543064

  6. Methylenetetrahydrofolate reductase activity is involved in the plasma membrane redox system required for pigment biosynthesis in filamentous fungi.

    PubMed

    Frandsen, Rasmus J N; Albertsen, Klaus Selk; Stougaard, Peter; Sørensen, Jens L; Nielsen, Kristian F; Olsson, Stefan; Giese, Henriette

    2010-08-01

    Methylenetetrahydrofolate reductases (MTHFRs) play a key role in biosynthesis of methionine and S-adenosyl-l-methionine (SAM) via the recharging methionine biosynthetic pathway. Analysis of 32 complete fungal genomes showed that fungi were unique among eukaryotes by having two MTHFRs, MET12 and MET13. The MET12 type contained an additional conserved sequence motif compared to the sequences of MET13 and MTHFRs from other eukaryotes and bacteria. Targeted gene replacement of either of the two MTHFR encoding genes in Fusarium graminearum showed that they were essential for survival but could be rescued by exogenous methionine. The F. graminearum strain with a mutation of MET12 (FgDeltaMET12) displayed a delay in the production of the mycelium pigment aurofusarin and instead accumulated nor-rubrofusarin and rubrofusarin. High methionine concentrations or prolonged incubation eventually led to production of aurofusarin in the MET12 mutant. This suggested that the chemotype was caused by a lack of SAM units for the methylation of nor-rubrofusarin to yield rubrofusarin, thereby imposing a rate-limiting step in aurofusarin biosynthesis. The FgDeltaMET13 mutant, however, remained aurofusarin deficient at all tested methionine concentrations and instead accumulated nor-rubrofusarin and rubrofusarin. Analysis of MET13 mutants in F. graminearum and Aspergillus nidulans showed that both lacked extracellular reduction potential and were unable to complete mycelium pigment biosynthesis. These results are the first to show that MET13, in addition to its function in methionine biosynthesis, is required for the generation of the extracellular reduction potential necessary for pigment production in filamentous fungi.

  7. C677T mutation in methylenetetrahydrofolate reductase gene and neural tube defects: should Japanese women undergo gene screening before pregnancy?

    PubMed

    Kondo, Atsuo; Fukuda, Hiromi; Matsuo, Takuya; Shinozaki, Keiko; Okai, Ikuyo

    2014-02-01

    We analyzed the role of maternal C677T mutation in methylenetetrahydrofolate reductase (MTHFR) gene on spina bifida development in newborns. A total of 115 mothers who had given birth to a spina bifida child (SB mothers) gave 10 mL of blood together with written informed consent. The genotype distribution of C677T mutation was assessed and compared with that of the 4517 control individuals. The prevalence of the homozygous genotype (TT) among SB mothers was not significantly different from that among the controls (odds ratio [OR] = 0.65; 95% confidence interval [CI] = 0.31-1.25; P = 0.182), suggesting that MTHFR 677TT genotype in Japan is not associated with spina bifida development in newborns. The T allele frequency was not increased in SB mothers (34.8%) as compared to that of the control individuals (38.2%). Further, the internationally reported association between the two groups was found to be similar in all 15 countries studied except the Netherlands, where the TT genotype was found to be a genetic risk factor for spina bifida. For the prevention of affected pregnancy every woman planning to conceive has to take folic acid supplements 400 μg a day and the government is asked to take action in implementing food fortification with folic acid in the near future. In conclusion, it is not necessary for Japanese women to undergo genetic screening C677T mutation of the MTHFR gene as a predictive marker for spina bifida prior to pregnancy, because the TT genotype is not a risk factor for having an affected infant.

  8. A second common mutation in the methylenetetrahydrofolate reductase gene: an additional risk factor for neural-tube defects?

    PubMed Central

    van der Put, N M; Gabreëls, F; Stevens, E M; Smeitink, J A; Trijbels, F J; Eskes, T K; van den Heuvel, L P; Blom, H J

    1998-01-01

    Recently, we showed that homozygosity for the common 677(C-->T) mutation in the methylenetetrahydrofolate reductase (MTHFR) gene, causing thermolability of the enzyme, is a risk factor for neural-tube defects (NTDs). We now report on another mutation in the same gene, the 1298(A-->C) mutation, which changes a glutamate into an alanine residue. This mutation destroys an MboII recognition site and has an allele frequency of .33. This 1298(A-->C) mutation results in decreased MTHFR activity (one-way analysis of variance [ANOVA] P < .0001), which is more pronounced in the homozygous than heterozygous state. Neither the homozygous nor the heterozygous state is associated with higher plasma homocysteine (Hcy) or a lower plasma folate concentration-phenomena that are evident with homozygosity for the 677(C-->T) mutation. However, there appears to be an interaction between these two common mutations. When compared with heterozygosity for either the 677(C-->T) or 1298(A-->C) mutations, the combined heterozygosity for the 1298(A-->C) and 677(C-->T) mutations was associated with reduced MTHFR specific activity (ANOVA P < .0001), higher Hcy, and decreased plasma folate levels (ANOVA P <.03). Thus, combined heterozygosity for both MTHFR mutations results in similar features as observed in homozygotes for the 677(C-->T) mutation. This combined heterozygosity was observed in 28% (n =86) of the NTD patients compared with 20% (n =403) among controls, resulting in an odds ratio of 2.04 (95% confidence interval: .9-4.7). These data suggest that the combined heterozygosity for the two MTHFR common mutations accounts for a proportion of folate-related NTDs, which is not explained by homozygosity for the 677(C-->T) mutation, and can be an additional genetic risk factor for NTDs. PMID:9545395

  9. Plasma homocysteine in adolescents depends on the interaction between methylenetetrahydrofolate reductase genotype, lipids and folate: a seroepidemiological study

    PubMed Central

    Gil-Prieto, Ruth; Hernández, Valentín; Cano, Beatriz; Oya, Manuel; Gil, Ángel

    2009-01-01

    Background Many publications link high homocysteine levels to cardiovascular disease. In Spain there is little information on the prevalence of hyperhomocysteinaemia and associated vitamin factors among the general population, and less still among children. Cardiovascular risk factors in the childhood population may be related to the appearance of cardiovascular disease at adult age. The aim of this study is to establish a definition of hyperhomocysteinaemia in adolescents and to analyze the influence of vitamin and metabolic factors in homocysteine levels in this population group. Methods Descriptive, cross-sectional epidemiological study to estimate serum homocysteine, vitamin B12 and folate levels, as well as plasma total, HDL- and LDL- cholesterol in a schoolgoing population aged 13 to 17 years in Madrid, Spain. Spearman correlation analysis was performed to ascertain quantitative comparison, Pearson's χ2 test (frequency < 5, Fisher) was used for comparison of prevalences, Mann-Whitney U and Kruskal-Wallis test were used for comparison of means and Bonferroni correction was used for post-hoc tests. A multivariate logistic regression model was performed in the multivariate analysis. Results Based on the classic values for definition of hyperhomocysteinaemia in adults, prevalence of hyperhomocysteinaemia in the study population was: 1.26% for 15 μmol/L; and 2.52% for 12 μmol/L. Deficits in HDL cholesterol and serum folate levels yielded adjusted Odds Ratios (OR) for hyperhomocysteinemia of 2.786, 95% CI (1.089-7.126), and 5.140, 95% CI (2.347-11.256) respectively. Mutation of the methylenetetrahydrofolate reductase (MTHFR) C677T genotype also raises the risk of hyperhomocysteinaemia (CC→CT: OR = 2.362; 95% CI (1.107-5.042) CC→TT: OR = 6.124, 95% CI (2.301-16.303)) Conclusion A good definition of hyperhomocysteinaemia in adolescents is the 90th percentile, equivalent to 8.23 μmol/L. Risk factors for hyperhomocysteinaemia are cHDL and folate deficiency, and

  10. Identification of a putative methylenetetrahydrofolate reductase by sequence analysis of a 6.8 kb DNA fragment of yeast chromosome VII.

    PubMed

    Tizon, B; Rodríguez-Torres, M; Rodríguez-Belmonte, E; Cadahia, J L; Cerdan, E

    1996-09-01

    We report the sequence analysis of a 6.8 kb DNA fragment from Saccharomyces cerevisiae chromosome VII. This sequence contains five open reading frames (ORFs) greater than 100 amino acids. There is also an incomplete ORF flanking one of the extremes, G2868, which is the 3' end of the SCS3 gene (Hosaka et al., 1994). The translated sequence of ORF G2882 shows similarity to the human methylenetetrahydrofolate reductase (Goyette et al., 1994). ORF G2889 shows no significant homologies with the sequences compiled in databases. ORF G2893 corresponds to the gene SUP44, coding for the yeast ribosomal protein S4 (All-Robin et al., 1990). G2873 and G2896 are internal ORFs.

  11. The Prevalence of Factor V Leiden (G1691A) and Methylenetetrahydrofolate Reductase C677T Mutations in Sickle Cell Disease in Western India.

    PubMed

    Kangne, Harshada K; Jijina, Farah F; Italia, Yazdi M; Jain, Dipti L; Nadkarni, Anita H; Ghosh, Kanjaksha K; Colah, Roshan B

    2015-03-01

    The prevalence of the Factor V Leiden (FVL; G1691A) mutation and the methylenetetrahydrofolate reductase (MTHFR; C677T) mutation was determined in 180 patients with sickle cell (SS) disease (126 sickle homozygous and 54 sickle β-thalassaemia--age 1-47 years) and in 130 healthy controls. The FVL mutation in the heterozygous state was present in only 3 patients with SS disease and was absent in the controls. Genotyping of MTHFR 677C > T revealed increased frequency of the C allele than the T allele in patients as well as in controls. This suggests that these genetic markers may not be major risk factors for a hypercoagulable state in Indian patients with SS disease.

  12. Thyroid vein thrombosis in a young woman with methylenetetrahydrofolate reductase gene mutation receiving cyproterone acetate/ethinylestradiol treatment for polycystic ovary syndrome: a case report.

    PubMed

    Nazli, Yunus; Colak, Necmettin; Aksoy, Omer N; Cakir, Omer

    2011-06-01

    Thyroid vein thrombosis is a rare variety of venous thrombosis. The use of oral contraceptives and heterozygous methylenetetrahydrofolate reductase (MTHFR) gene mutation could have synergistic effects on the onset of venous thromboembolism. We report a 28-year-old woman with thyroid vein thrombosis. The thrombosis was possibly provoked by a combination of heterozygous MTHFR gene mutation and the use of a combined oral contraceptive (COC) containing cyproterone acetate/ethinylestradiol (CPA/EE) for polycystic ovary syndrome (PCOS). The patient was treated successfully with low molecular weight heparin and oral anticoagulation. The thyroid vein thrombosis resolved and the patient was advised to maintain lifelong use of anticoagulation therapy. Our report emphasizes that the combination of heterozygous MTHFR gene mutation, PCOS, and the use of a COC-containing CPA/EE could increase risk of thyroid vein thrombosis in young adults.

  13. Increased resistance to malaria in mice with methylenetetrahydrofolate reductase (Mthfr) deficiency suggests a mechanism for selection of the MTHFR 677C>T (c.665C>T) variant.

    PubMed

    Meadows, Danielle N; Pyzik, Michal; Wu, Qing; Torre, Sabrina; Gros, Philippe; Vidal, Silvia M; Rozen, Rima

    2014-05-01

    The polymorphism 677C>T (NM_005957.4:c.665C>T/p.Ala222Val, rs1801133:C>T) in methylenetetrahydrofolate reductase (MTHFR) results in mild enzymatic deficiency and increased risk for several complex traits including adverse reproductive outcomes, birth defects, and heart disease. Despite these deleterious effects, homozygosity is high (5%-15%) in many populations, and among the highest in Mediterranean regions, where malaria was historically endemic and may have conferred a selective advantage for other mutations. We infected Mthfr-deficient (Mthfr(+) (/-) ) and MTHFR overexpressing (MTHFR(Tg) ) mice with Plasmodium berghei ANKA to induce cerebral malaria. Mthfr(+/-) mice survived longer (P < 0.02, log-rank test), and MTHFR(Tg) mice died earlier (P < 0.05, log-rank test) after infection compared with wild-type littermates. Flow cytometry revealed increased lymphocyte populations and increased CCR4(+) NK cells in spleen of Mthfr(+) (/-) mice; MTHFR(Tg) animals had decreased numbers of these NK cells. Interferon-γ and interleukin-10 immunoreactive proteins were increased and decreased, respectively, in brain of Mthfr(+/-) mice compared with wild-type. We suggest that mild MTHFR deficiency protects against malarial infection and that this phenomenon may have led to the high frequency of the 677C>T/c.665C>T variant in human populations.

  14. The methylenetetrahydrofolate reductase C677T mutation induces cell-specific changes in genomic DNA methylation and uracil misincorporation: a possible molecular basis for the site-specific cancer risk modification.

    PubMed

    Sohn, Kyoung-Jin; Jang, Hyeran; Campan, Mihaela; Weisenberger, Daniel J; Dickhout, Jeffrey; Wang, Yi-Cheng; Cho, Robert C; Yates, Zoe; Lucock, Mark; Chiang, En-Pei; Austin, Richard C; Choi, Sang-Woon; Laird, Peter W; Kim, Young-In

    2009-05-01

    The C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene is associated with a decreased risk of colon cancer although it may increase the risk of breast cancer. This polymorphism is associated with changes in intracellular folate cofactors, which may affect DNA methylation and synthesis via altered one-carbon transfer reactions. We investigated the effect of this mutation on DNA methylation and uracil misincorporation and its interaction with exogenous folate in further modulating these biomarkers of one-carbon transfer reactions in an in vitro model of the MTHFR 677T mutation in HCT116 colon and MDA-MB-435 breast adenocarcinoma cells. In HCT116 cells, the MTHFR 677T mutation was associated with significantly increased genomic DNA methylation when folate supply was adequate or high; however, in the setting of folate insufficiency, this mutation was associated with significantly decreased genomic DNA methylation. In contrast, in MDA-MB-435 cells, the MTHFR 677T mutation was associated with significantly decreased genomic DNA methylation when folate supply was adequate or high and with no effect when folate supply was low. The MTHFR 677T mutation was associated with a nonsignificant trend toward decreased and increased uracil misincorporation in HCT116 and MDA-MB-435 cells, respectively. Our data demonstrate for the first time a functional consequence of changes in intracellular folate cofactors resulting from the MTHFR 677T mutation in cells derived from the target organs of interest, thus providing a plausible cellular mechanism that may partly explain the site-specific modification of colon and breast cancer risks associated with the MTHFR C677T mutation.

  15. Elevated total plasma homocysteine and 667C{r_arrow}T mutation of the 5,10-methylenetetrahydrofolate reductase gene in thrombotic vascular disease

    SciTech Connect

    De Franchis, R.; Sebastio, G.; Andria, G.

    1996-07-01

    Moderate elevation of total plasma homocysteine (tHcy) has been reported as an independent risk factor for thrombotic vascular disease, a well-known multifactorial disorder. Possible genetic causes of elevated tHcy include defects of the sulfur-containing amino acids metabolism due to deficiencies of cystathionine {Beta}-synthase, of 5,10-methylenetetrahydrofolate reductase (MTHFR), and of the enzymes of cobalamin metabolism. An impaired activity of MTHFR due to a thermolabile form of the enzyme has been observed in {le}28% of hyperhomocysteinemic patients with premature vascular disease. More recently, the molecular basis of such enzymatic thermolability has been related to a common mutation of the MTHFR gene, causing a C-to-T substitution at nt 677 (677C{r_arrow}T). This mutation was found in 38% of unselected chromosomes from 57 French Canadian individuals. The homozygous state for the mutation was present in 12% of these subjects and correlated with significantly elevated tHcy. Preliminary evidence indicates that the frequency of homozygotes for the 677C{r_arrow}T mutation may vary significantly in populations from different geographic areas. 5 refs., 2 tabs.

  16. Massive pulmonary embolism associated with Factor V Leiden, prothrombin, and methylenetetrahydrofolate reductase gene mutations in a young patient on oral contraceptive pills: a case report.

    PubMed

    Charafeddine, Khalil M; Mahfouz, Rami A; Ibrahim, Georges Y; Taher, Ali T; Hoballah, Jamal J; Taha, Assad M

    2010-10-01

    Factor V Leiden (Factor V G1691A), prothrombin gene mutation G20210A, and homozygous C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene are known to predispose venous thromboembolism (VTE). We present herein a rare case of a young woman heterozygous for these mutations and taking oral contraceptive pills for less than 2 months, diagnosed to have massive deep venous thrombosis and bilateral pulmonary embolism. The patient was managed for 10 days in the hospital and discharged home on oral anticoagulants. This case suggests that screening for these factors in people with family history of thrombosis and in relatives of patients with these mutations is highly recommended to prevent fatal consequences. In addition, a new guideline for treatment and prophylaxis with anticoagulant for these patients and others who are at risk of developing VTE (American College of Chest Physicians [ACCP] guidelines-Chest 2008) has been published recently. Our recommendation is to promote for the internationally published algorithms through their application, where necessary, to prevent any future thrombotic morbidity or mortality incidents.

  17. Recurrent cerebral venous thrombosis associated with heterozygote methylenetetrahydrofolate reductase C677T mutation and sickle cell trait without homocysteinemia: an autopsy case report and review of literature.

    PubMed

    Ali, Z; Troncoso, J C; Fowler, D R

    2014-09-01

    Elevated blood homocysteine concentration and certain genetic mutations have been associated with increased risk for developing arterial and venous thrombosis. A common mutation of methylenetetrahydrofolate reductase, MTHFR C677T, has been associated with elevated homocysteine concentration and increased risk for developing thrombosis in homozygote carriers. Heterozygote carriers for this gene mutation, if associated with other major or minor risk factors for thrombophilia, appear to be prone to develop thrombosis. A postmortem genetic testing for common mutations resulting in thrombophilia should be performed in all individuals who die as a result of thrombosis, regardless of predisposing risk factors, to determine the true prevalence of mutations in these individuals, and to assess the true role of a certain mutation, such as heterozygote MTHFR C677T, in the pathogenesis of thrombosis. Postmortem genetic testing for common mutations associated with thrombophilia in selected cases has potentially life-saving importance to surviving family members. We report a case of recurrent cerebral venous thrombosis in a 19 year old male with history of sickle cell trait, obesity, and high normal blood homocysteine, who was heterozygote for MTHFR C677T mutation.

  18. A cross-sectional study to find out the relationship of methylenetetrahydrofolate reductase (MTHFR) C677T genotype with plasma levels of folate and total homocysteine by daily folate intake in Japanese.

    PubMed

    Fukuda, Nana; Hamajima, Nobuyuki; Wakai, Kenji; Suzuki, Koji

    2014-01-01

    In those with the methylenetetrahydrofolate reductase (MTHFR) 677TT genotype, enzyme activity is lowered. Therefore, these individuals might require an increased intake of folate to maintain or control blood levels of plasma folate or total homocysteine (tHcy). We examined associations of dietary folate intake with fasting plasma folate and total homocysteine (tHcy) according to genotype among 554 Japanese (207 men and 347 women aged 39-89 y) recruited in 2009. Intake of folate was estimated with a food frequency questionnaire. The MTHFR polymorphism was genotyped by a polymerase chain reaction with confronting two-pair primers. The log-transformed concentration of folate or tHcy was regressed on energy-adjusted folate intake in a linear regression analysis. Higher folate intake was associated with higher plasma folate among those with the CC (β=0.165, p=0.066) or CT (β=0.248, p<0.001) genotypes, and with lower tHcy levels only among those with the CC (β=-0.141, p=0.013) genotype. Plasma folate was significantly and inversely associated with tHcy, irrespective of MTHFR genotype. When the analysis was restricted to those with tHcy levels higher than the reference range (≥13.5 nmol/mL, n=20), these significant associations were not found. The interaction between folate intake or plasma folate and genotype was not significant in any analysis. In conclusion, dietary folate intake was positively associated with plasma folate among those with the CC or CT genotypes and inversely associated with tHcy among those with the CC genotype, but the associations were not clear among those with higher levels of tHcy.

  19. The model homologue of the partially defective human 5,10-methylenetetrahydrofolate reductase, considered as a risk factor for stroke due to increased homocysteine level, can be protected and reactivated by heat shock proteins.

    PubMed

    Grabowski, Michał; Banecki, Bogdan; Kadziński, Leszek; Jakóbkiewicz-Banecka, Joanna; Gabig-Cimińska, Magdalena; Węgrzyn, Alicja; Węgrzyn, Grzegorz; Banecka-Majkutewicz, Zyta

    2016-10-01

    The A222 V substitution in the human MTHFR gene product (5,10-methylenetetrahydrofolate reductase) is responsible for a decreased activity of this enzyme. This may cause an increased homocysteine level, considered as a risk factor for arteriosclerosis and stroke. The bacterial homologue of the human enzyme, MetF, has been found to be a useful model in genetic and biochemical studies. The similarity of Escherichia coli MetF and human MTHFR proteins is so high that particular mutations in the corresponding human gene can be reflected by the bacterial mutants. For example, the A222 V substitution in MTHFR (caused by the C667T substitution in the MTHFR gene) can be ascribed to the A117 V substitution in MetF. Here, it is reported that a temperature-sensitive MetF117 (A117 V) protein can be partially protected from a thermal inactivation by the heat shock proteins from the Hsp70/100 systems. Moreover, activity of the thermally denatured enzyme can be partially restored by the same heat shock proteins. High temperature protein G (HtpG) had no effect on MetF117 activity in both experimental systems. The presented results indicate that functions of heat shock proteins may be required for maintenance of the MetF117 function. This may have implications for the mechanisms of arteriosclerosis and stroke, especially in the light of previous findings that the A222 V MTHFR polymorphism may be a risk factor for stroke, as well as recently published results which demonstrated the increased levels of antibodies against heat shock proteins in stroke patients.

  20. Choline Intake, Plasma Riboflavin, and the Phosphatidylethanolamine N-Methyltransferase G5465A Genotype Predict Plasma Homocysteine in Folate-Deplete Mexican-American Men with the Methylenetetrahydrofolate Reductase 677TT Genotype12

    PubMed Central

    Caudill, Marie A.; Dellschaft, Neele; Solis, Claudia; Hinkis, Sabrina; Ivanov, Alexandre A.; Nash-Barboza, Susan; Randall, Katharine E.; Jackson, Brandi; Solomita, Gina N.; Vermeylen, Francoise

    2009-01-01

    We previously showed that provision of the folate recommended dietary allowance and either 300, 550, 1100, or 2200 mg/d choline for 12 wk resulted in diminished folate status and a tripling of plasma total homocysteine (tHcy) in men with the methylenetetrahydrofolate reductase (MTHFR) 677TT genotype. However, the substantial variation in tHcy within the 677TT genotype at wk 12 implied that several factors were interacting with this genotype to affect homocysteine. As an extension of this work, the present study sought to identify the main predictors of wk-12 plasma tHcy, alone and together with the MTHFR C677T genotype (29 TT, 31 CC), using linear regression analysis. A basic model explaining 82.5% of the variation (i.e. adjusted R2 = 0.825) was constructed. However, the effects of the variables within this model were dependent upon the MTHFR C677T genotype (P for interaction ≤ 0.021). Within the 677TT genotype, serum folate (P = 0.005) and plasma riboflavin (P = 0.002) were strong negative predictors (inversely related) explaining 12 and 15%, respectively, of the variation in tHcy, whereas choline intake (P = 0.003) and serum creatinine (P < 0.001) were strong positive predictors, explaining 19 and 25% of the variation. None of these variables, except creatinine (P = 0.021), correlated with tHcy within the 677CC genotype. Of the 8 additional polymorphisms tested, none appeared to influence tHcy. However, when creatinine was not in the model, the phosphatidylethanolamine N-methyltransferase 5465G→A variant predicted lower tHcy (P < 0.001); an effect confined to the MTHFR 677TT genotype. Thus, in folate-deplete men, several factors with roles in 1-carbon metabolism interact with the MTHFR C677T genotype to affect plasma tHcy. PMID:19211833

  1. Complete deficiency of methylenetetrahydrofolate reductase in mice is associated with impaired retinal function and variable mortality, hematological profiles, and reproductive outcomes.

    PubMed

    Lawrance, Andrea K; Racine, Julie; Deng, Liyuan; Wang, Xiaoling; Lachapelle, Pierre; Rozen, Rima

    2011-02-01

    Severe deficiency of methylenetetrahydrofolate reductase (MTHFR) with homocystinuria can result in early demise or later-onset neurological impairment, including developmental delay, motor dysfunction, and seizures. We previously characterized BALB/c Mthfr (-/-)mice as a model for this disorder and have recently backcrossed the disrupted allele onto the C57Bl/6 background to examine the variable phenotypes in MTHFR deficiency. Compared with BALB/c Mthfr (-/-)mice, C57Bl/6 Mthfr (-/-)mice have enhanced survival rates (81% vs 26.5%). Four-day-old BALB/c mutant pups had lower body, brain, and spleen weights relative to their wild-type counterparts compared with C57Bl/6 mutants. Pregnant BALB/c Mthfr (+/-)mice had increased resorptions and embryonic delays compared with wild-type littermates, whereas these outcomes in C57Bl/6 c Mthfr (+/-)mice were similar to those of wild-type C57Bl/6 mice. BALB/c-mutant pups had altered hematological profiles (higher hematocrit, hemoglobin, and white blood cell counts, with lower platelet counts) compared with C57Bl/6 mutants. Mutants of both strains had similar degrees of hepatic steatosis, hepatic activity of betaine:homocysteine methyltransferase, and altered cerebellar histology. Electroretinograms (ERG) in C57Bl/6 Mthfr (-/-)mice revealed decreased amplitude of scotopic and photopic waves in 6-week-old mice, with normalized ERGs at 13 weeks. Plasma homocysteine was modestly higher in C57Bl/6 compared with BALB/c mice. Our results emphasize the variable presentation of MTHFR deficiency in different genetic backgrounds and suggest that plasma homocysteine is not a predictor of severity. In addition, our novel findings of decreased spleen weights, thrombocytopenia, and impaired retinal function warrant investigation in patients with severe MTHFR deficiency or other forms of homocystinuria.

  2. Molecular genetic analysis in mild hyperhomocysteinemia: A common mutation in the methylenetetrahydrofolate reductase gene is a genetic risk factor for cardiovascular disease

    SciTech Connect

    Kluijtmans, L.A.J.; Heuvel, L.P.W.J. van den; Stevens, E.M.B.

    1996-01-01

    Mild hyperhomocysteinemia is an established risk factor for cardiovascular disease. Genetic aberrations in the cystathionine P-synthase (CBS) and methylenetetrahydrofolate reductase (MTHFR) genes may account for reduced enzyme activities and elevated plasma homocysteine levels. In 15 unrelated Dutch patients with homozygous CBS deficiency, we observed the 833T{yields}C (1278T) mutation in 50% of the alleles. Very recently, we identified a common mutation (677C{yields}T; A{yields}V) in the MTHFR gene, which, in homozygous state, is responsible for the thermolabile phenotype and which is associated with decreased specific MTHFR activity and elevated homocysteine levels. We screened 60 cardiovascular patients and 111 controls for these two mutations, to determine whether these mutations are risk factors for premature cardiovascular disease. Heterozygosity for the 833T{yields}C mutation in the CBS gene was observed in one individual of the control group but was absent in patients with premature cardiovascular disease. Homozygosity for the 677C-{yields}T mutation in the MTHFR gene was found in 9 (15%) of 60 cardiovascular patients and in only 6 ({approximately}5%) of 111 control individuals (odds ratio 3.1 [95% confidence interval 1.0-9.21]). Because of both the high prevalence of the 833T-{yields}C mutation among homozygotes for CBS deficiency and its absence in 60 cardiovascular patients, we may conclude that heterozygosity for CBS deficiency does not appear to be involved in premature cardiovascular disease. However, a frequent homozygous mutation in the MTHFR gene is associated with a threefold increase in risk for premature cardiovascular disease. 35 refs., 3 figs., 1 tab.

  3. The "thermolabile" variant of methylenetetrahydrofolate reductase and neural tube defects: An evaluation of genetic risk and the relative importance of the genotypes of the embryo and the mother.

    PubMed Central

    Shields, D C; Kirke, P N; Mills, J L; Ramsbottom, D; Molloy, A M; Burke, H; Weir, D G; Scott, J M; Whitehead, A S

    1999-01-01

    Recent reports have implicated the "thermolabile" (T) variant of methylenetetrahydrofolate reductase (MTHFR) in the causation of folate-dependent neural tube defects (NTDs). We report herein the largest genetic study of NTD cases (n=271) and families (n=218) to date, establishing that, in Ireland, the "TT" genotype is found in 18.8% of cases versus 8.3% of controls (odds ratio 2.57; confidence interval [CI] 1.48-4.45; P=.0005). The maternal and paternal TT genotypes have intermediate frequencies of 13.8% and 11.9%, respectively, indicating that the predominant MTHFR-related genetic effect acts via the TT genotype of the developing embryo. Analysis of the 218 family triads of mother, father, and affected child with log-linear models supports this interpretation, providing significant evidence that the case TT genotype is associated with NTDs (P=.02) but no evidence of a maternal TT genotypic effect (P=. 83). The log-linear model predicted that the risk of NTDs conferred by the case TT genotype is 1.61 (CI 1.06-2.46), consistent with the paramount importance of the case TT genotype in determining risk. There is no compelling evidence for more than a modest additional risk conferred by a maternal TT genotype. These results favor a biological model of MTHFR-related NTD pathogenesis in which suboptimal maternal folate status imposes biochemical stress on the developing embryo, a stress it is ill-equipped to tolerate if it has a TT genotype. PMID:10090889

  4. Molecular genetic analysis in mild hyperhomocysteinemia: a common mutation in the methylenetetrahydrofolate reductase gene is a genetic risk factor for cardiovascular disease.

    PubMed Central

    Kluijtmans, L. A.; van den Heuvel, L. P.; Boers, G. H.; Frosst, P.; Stevens, E. M.; van Oost, B. A.; den Heijer, M.; Trijbels, F. J.; Rozen, R.; Blom, H. J.

    1996-01-01

    Mild hyperhomocysteinemia is an established risk factor for cardiovascular disease. Genetic aberrations in the cystathionine beta-synthase (CBS) and methylenetetrahydrofolate reductase (MTHFR) genes may account for reduced enzyme activities and elevated plasma homocysteine levels. In 15 unrelated Dutch patients with homozygous CBS deficiency, we observed the 833T-->C (I278T) mutation in 50% of the alleles. Very recently, we identified a common mutation (677C-->T; A-->V) in the MTHFR gene, which, in homozygous state, is responsible for the thermolabile phenotype and which is associated with decreased specific MTHRF activity and elevated homocysteine levels. We screened 60 cardiovascular patients and 111 controls for these two mutations, to determine whether these mutations are risk factors for premature cardiovascular disease. Heterozygosity for the 833T-->C mutation in the CBS gene was observed in one individual of the control group but was absent in patients with premature cardiovascular disease. Homozygosity for the 677C-->T mutation in the MTHFR gene was found in (15%) of 60 cardiovascular patients and in only 6 (approximately 5%) of 111 control individuals (odds ratio 3.1 [95% confidence interval 1.0-9.2]). Because of both the high prevalence of the 833T-->C mutation among homozygotes for CBS deficiency and its absence in 60 cardiovascular patients, we may conclude that heterozygosity for CBS deficiency does not appear to be involved in premature cardiovascular disease. However, a frequent homozygous mutation in the MTHFR gene is associated with a threefold increase in risk for premature cardiovascular disease. PMID:8554066

  5. [C677T polymorphism of the methylentetrahydrofolate reductase gene in mothers of children affected with neural tube defects].

    PubMed

    Morales de Machín, Alisandra; Méndez, Karile; Solís, Ernesto; Borjas de Borjas, Lisbeth; Bracho, Ana; Hernández, María Luisa; Negrón, Aimara; Delgado, Wilmer; Sánchez, Yanira

    2015-09-01

    Neural tube defects (NTD) are the most common congenital anomalies of the central nervous system, with a multifactorial pattern of inheritance, presumably involving the interaction of several genetic and environmental factors. The methylenetetrahydrofolate reductase (MTHFR) gene 677C>T polymorphism has been implicated as a risk factor for NTD. The main objective of this research was to investigate the association of the 677C>T polymorphism of the MTHFR gene as a genetic risk factor for NTD. Molecular analysis was performed in DNA samples from 52 mothers with antecedent of NTD offspring and from 119 healthy control mothers. Using the Polymerase Chain Reaction, a 198 bases pairs fragment was digested with the restriction enzyme Hinfi. 677T MTHFR allele frequencies for the problem and the control groups were 51.92% and 34.45%, respectively, and 677C MTHFR allele frequencies were 48.08% and 65.55%, respectively. There were significant differences in allele (p: 0.002) and genotype (p: 0.007) frequencies between these two groups. The odds ratio (OR) to the TT genotype vs. the CC genotype was estimated as OR: 4.9 [95% CI: 1,347-6.416] p: 0.002; CT+TT vs. CC: OR: 2.9 [95% CI: 1.347-6.416] p: 0.005; TT vs. CT+CC: OR: 2.675 [95% CI: 1,111-6.441] p: 0.024. The data presented in this study support the relationship between MTHFR 677C>T polymorphism and risk in mothers with antecedent of NTD offspring.

  6. Genetic Variation of Methylenetetrahydrofolate Reductase (MTHFR) and Thymidylate Synthase (TS) Genes Is Associated with Idiopathic Recurrent Implantation Failure

    PubMed Central

    Shim, Sung Han; Lee, Yubin; Kim, Ji Hyang; Jeon, Young Joo; Ko, Jung Jae; Lee, Woo Sik; Kim, Nam Keun

    2016-01-01

    The one-carbon metabolism pathway disorder was important role in successful pregnancy. The MTHFR and TS protein were crucial factor in one-carbon metabolism. To investigate the association between recurrent implantation failure (RIF) and enzymes in the one-carbon metabolism pathway. A total of 120 women diagnosed with RIF and 125 control subjects were genotyped for MTHFR 677C>T, 1298A>C, TSER 2R/3R and TS 1494del/ins by a polymerase chain reaction-restriction fragment length polymorphism assay. According to the gene-gene combination analysis, the MTHFR 677/MTHFR 1298 (TT/AA) and MTHFR 677/TS 1494 (TT/6bp6bp) genetic combinations were associated with relatively higher risks [adjusted odds ratio (AOR), 2.764; 95% CI, 1.065–7.174; P = 0.037 and AOR, 3.186; 95% CI, 1.241–8.178; P = 0.016] in RIF patients compared to the CC/AA (MTHFR 677/MTHFR 1298) and TT/6bp6bp (MTHFR 677/TS 1494) combinations, respectively. The results suggested that the combined MTHFR 677/MTHFR 1298 genotype might be associated with increased risk of RIF. To the best of our knowledge, this study is the first to elucidate the potential association of MTHFR, TS and TSER polymorphisms with RIF risk in Korean patients. PMID:27560137

  7. Regulation of Folate-Mediated One-Carbon Metabolism by Glycine N-Methyltransferase (GNMT) and Methylenetetrahydrofolate Reductase (MTHFR).

    PubMed

    Wang, Yi-Cheng; Wu, Ming-Tsung; Lin, Yan-Jun; Tang, Feng-Yao; Ko, Hsin-An; Chiang, En-Pei

    2015-01-01

    Folate-mediated one-carbon metabolism is an important therapeutic target of human diseases. We extensively investigated how gene-nutrient interactions may modulate human cancer risk in 2 major folate metabolic genes, MTHFR and GNMT. The biochemical impacts of MTHFR and GNMT on methyl group supply, global DNA methylation, nucleotide biosynthesis, DNA damage, and partitioning of the folate dependent 1-carbon group were carefully studied. The distinct model systems used included: EB virus-transformed lymphoblasts expressing human MTHFR polymorphic genotypes; liver-derived GNMT-null cell-lines with and without GNMT overexpression; and HepG2 cells with stabilized inhibition of MTHFR using shRNA, GNMT wildtype, heterozygotous (GNMT(het)) and knockout (GNMT(nul)) mice. We discovered that the MTHFR TT genotype significantly reduces folate-dependent remethylation under folate restriction, but it assists purine synthesis when folate is adequate. The advantage of de novo purine synthesis found in the MTHFR TT genotype may account for the protective effect of MTHFR in human hematological malignancies. GNMT affects transmethylation kinetics and S-adenosylmethionine (adoMet) synthesis, and facilitates the conservation of methyl groups by limiting homocysteine remethylation fluxes. Restoring GNMT assists methylfolate-dependent reactions and ameliorates the consequences of folate depletion. GNMT expression in vivo improves folate retention and bioavailability in the liver. Loss of GNMT impairs nucleotide biosynthesis. Over-expression of GNMT enhances nucleotide biosynthesis and improves DNA integrity by reducing uracil misincorporation in DNA both in vitro and in vivo. The systematic series of studies gives new insights into the underlying mechanisms by which MTHFR and GNMT may participate in human tumor prevention.

  8. Fundamental Role of Methylenetetrahydrofolate Reductase 677 C → T Genotype and Flavin Compounds in Biochemical Phenotypes for Schizophrenia and Schizoaffective Psychosis

    PubMed Central

    Fryar-Williams, Stephanie

    2016-01-01

    The Mental Health Biomarker Project (2010–2016) explored variables for psychosis in schizophrenia and schizoaffective disorder. Blood samples from 67, highly characterized symptomatic cases and 67 gender and age matched control participants were analyzed for methyl tetrahydrofolate reductase (MTHFR) 677C → T gene variants and for vitamin B6, B12 and D, folate, unbound copper, zinc cofactors for enzymes in the methylation cycle, and related catecholamine pathways. Urine samples were analyzed for indole-catecholamines, their metabolites, and oxidative-stress marker, hydroxylpyrolline-2-one (HPL). Rating scales were Brief Psychiatric Rating Scale, Positive and Negative Syndrome Scale, Global Assessment of Function scale, Clinical Global Impression (CGI) score, and Social and Occupational Functioning Assessment Scale (SOFAS). Analysis used Spearman’s correlates, receiver operating characteristics and structural equation modeling (SEM). The correlative pattern of variables in the overall participant sample strongly implicated monoamine oxidase (MAO) enzyme inactivity so the significant role of MAO’s cofactor flavin adenine nucleotide and its precursor flavin adenine mononucleotide (FMN) within the biochemical pathways was investigated and confirmed as 71% on SEM of the total sample. Splitting the data sets for MTHFR 677C → T polymorphism variants coding for the MTHFR enzyme, discovered that biochemistry variables relating to the wild-type enzyme differed markedly in pattern from those coded by the homozygous variant and that the hereozygous-variant pattern resembled the wild-type-coded pattern. The MTHFR 677C → T-wild and -heterozygous gene variants have a pattern of depleted vitamin cofactors characteristic of flavin insufficiency with under-methylation and severe oxidative stress. The second homozygous MTHFR 677TT pattern related to elevated copper:zinc ratio and a vitamin pattern related to flavin sufficiency and risk of over-methylation. The

  9. Prothrombin G20210A and methylenetetrahydrofolate reductase C677T polymorphisms in peripheral capillary nonperfusion: a case report.

    PubMed

    Wathek, Chaima; Mrad, Meriem; Abdessalem, Nadia Ben; Maalej, Afef; Gritli, Nasreddine; Gabsi, Salem; Rannen, Riadh; Fekih-Mrissa, Najiba

    2015-09-01

    The G20210A mutation in the prothrombin gene is an established risk factor for venous thrombosis. However, there is some controversy as to the role played by this mutation in arterial thrombotic disease. The association of peripheral capillary nonperfusion with prothrombin G20210A mutation has never been reported before. We present the case of 34-year-old man who presented with peripheral capillary nonperfusion. The fundus examination of his right eye revealed an epiretinal membrane, peripheral (mainly temporally) retinal haemorrhages, exudates and microaneurismal alterations of the vascular bed. Fluorescein angiography of his right eye demonstrated an extended area of capillary nonperfusion distal to the microaneurismal lesions. Evaluation revealed mutations of the G20210A prothrombin and MTHFR genes. Screening for hereditary thrombophilia should be considered, regardless of patient age, in patients with peripheral retinal ischemia. The prothrombin G20210A mutation, a genetic risk factor, may be associated with peripheral capillary nonperfusion.

  10. Structures of NADH and CH[subscript 3]-H[subscript 4] Folate Complexes of Escherichia coli Methylenetetrahydrofolate Reductase Reveal a Spartan Strategy for a Ping-Pong Reaction

    SciTech Connect

    Pejchal, Robert; Sargeant, Ryan; Ludwig, Martha L.

    2010-03-08

    Methylenetetrahydrofolate reductases (MTHFRs; EC 1.7.99.5) catalyze the NAD(P)H-dependent reduction of 5,10-methylenetetrahydrofolate (CH{sub 2}-H{sub 4}folate) to 5-methyltetrahydrofolate (CH{sub 3}-H{sub 4}folate) using flavin adenine dinucleotide (FAD) as a cofactor. The initial X-ray structure of Escherichia coli MTHFR revealed that this 33-kDa polypeptide is a ({beta}{alpha}){sub 8} barrel that aggregates to form an unusual tetramer with only 2-fold symmetry. Structures of reduced enzyme complexed with NADH and of oxidized Glu28Gln enzyme complexed with CH{sub 3}-H{sub 4}folate have now been determined at resolutions of 1.95 and 1.85 {angstrom}, respectively. The NADH complex reveals a rare mode of dinucleotide binding; NADH adopts a hairpin conformation and is sandwiched between a conserved phenylalanine, Phe223, and the isoalloxazine ring of FAD. The nicotinamide of the bound pyridine nucleotide is stacked against the si face of the flavin ring with C4 adjoining the N5 of FAD, implying that this structure models a complex that is competent for hydride transfer. In the complex with CH{sub 3}-H{sub 4}folate, the pterin ring is also stacked against FAD in an orientation that is favorable for hydride transfer. Thus, the binding sites for the two substrates overlap, as expected for many enzymes that catalyze ping-pong reactions, and several invariant residues interact with both folate and pyridine nucleotide substrates. Comparisons of liganded and substrate-free structures reveal multiple conformations for the loops {beta}2-{alpha}2 (L2), {beta}3-{alpha}3 (L3), and {beta}4-{alpha}4 (L4) and suggest that motions of these loops facilitate the ping-pong reaction. In particular, the L4 loop adopts a 'closed' conformation that allows Asp120 to hydrogen bond to the pterin ring in the folate complex but must move to an 'open' conformation to allow NADH to bind.

  11. [Vascular diseases, spina bifida and schizophrenia in a single family associated with the heterozygote mutation of the heat-sensitive variant of methylenetetrahydrofolate reductase].

    PubMed

    Horváth, A; Morava, E; Tóth, G; Czakó, M; Melegh, B; Kosztolányi, G

    2001-07-08

    Homozygous mutation of the thermolabile variant of methylene tetrahydrofolate reductase (MTHFR) may result in hyperhomocystinemia, leading to an increased risk for early cardiovascular disease, neural tube defects, and possibly major depression, schizophrenia. According to recent studies heterozygosity for the thermolabile variant of the MTHFR gene mutation is also more frequent in patients with thrombotic disease compared to that in the average population. We report on a family with different types of early vascular disease. In four consecutive generations MTHFR heterozygosity was detected: in the proband and in her mother, grandfather and daughter. Further conditions of the family members, possibly due to carrying the mutation, came to light by the pedigree analysis and examinations. The patient had pulmonary emboli at young age, her aunt died of spina bifida shortly after birth. The patient's mother suffers from schizophrenia and depression. The grandfather had pulmonary emboli, her sister with spina bifida occulta also carries the same mutation, as does her daughter who is sofar asymptomatic. In other asymptomatic members of the family no mutations were found. Unexpectedly, hyperhomocystinemia was detected in all heterozygote individuals. Our study demonstrates the necessity for folic acid therapy in mutation carriers to prevent early vascular events, depression and schizophrenia, and also to reduce the risk for neural tube defects in a preconception setting.

  12. Analysis of methionine synthase reductase polymorphism (A66G) in Indian Muslim population

    PubMed Central

    Rai, Vandana; Yadav, Upendra; Kumar, Pradeep; Yadav, Sushil Kumar

    2013-01-01

    BACKGROUND AND OBJECTIVES: Methionine synthase reductase (MTRR) is a vital enzyme of homocysteine/methionine metabolic pathway and is required for the conversion of inactive form of methionine synthase (MTR) to its active form. A clinically important allelic variant of MTRR A66G, with less enzymatic activity is reported with worldwide prevalence rate of ~ 30%. The present study was designed to determine the frequency of MTRR A66G polymorphism in rural Sunni Muslim population of Eastern Uttar Pradesh. MATERIALS AND METHODS: Total 56 subjects were analyzed for MTRR A66G polymorphism. A66G mutation analysis was carried out according to the polymerase chain reaction-restriction fragment length polymorphism method of Wilson et al. [1] amplification with MTRR specific primers followed by amplicon digestion with NdeI enzyme was used for the identification of different MTRR genotypes in subjects. RESULTS AND DISCUSSION: The AA genotype was found in 5 subjects, AG in 23 subjects, and GG genotype in 28 subjects. Genotype frequencies of AA, AG, and GG were 0.089, 0.41, and 0.5 respectively. The allele frequency of A allele was found to be 0.298 and G allele was 0.705. CONCLUSION: It is evident from the present study that the percentage of homozygous genotype GG and frequency of G allele is high in the target Muslim population. PMID:24019620

  13. Malaria antifolate resistance with contrasting Plasmodium falciparum dihydrofolate reductase (DHFR) polymorphisms in humans and Anopheles mosquitoes

    PubMed Central

    Mharakurwa, Sungano; Kumwenda, Taida; Mkulama, Mtawa A. P.; Musapa, Mulenga; Chishimba, Sandra; Shiff, Clive J.; Sullivan, David J.; Thuma, Philip E.; Liu, Kun; Agre, Peter

    2011-01-01

    Surveillance for drug-resistant parasites in human blood is a major effort in malaria control. Here we report contrasting antifolate resistance polymorphisms in Plasmodium falciparum when parasites in human blood were compared with parasites in Anopheles vector mosquitoes from sleeping huts in rural Zambia. DNA encoding P. falciparum dihydrofolate reductase (EC 1.5.1.3) was amplified by PCR with allele-specific restriction enzyme digestions. Markedly prevalent pyrimethamine-resistant mutants were evident in human P. falciparum infections—S108N (>90%), with N51I, C59R, and 108N+51I+59R triple mutants (30–80%). This resistance level may be from selection pressure due to decades of sulfadoxine/pyrimethamine use in the region. In contrast, cycloguanil-resistant mutants were detected in very low frequency in parasites from human blood samples—S108T (13%), with A16V and 108T+16V double mutants (∼4%). Surprisingly, pyrimethamine-resistant mutants were of very low prevalence (2–12%) in the midguts of Anopheles arabiensis vector mosquitoes, but cycloguanil-resistant mutants were highly prevalent—S108T (90%), with A16V and the 108T+16V double mutant (49–57%). Structural analysis of the dihydrofolate reductase by in silico modeling revealed a key difference in the enzyme within the NADPH binding pocket, predicting the S108N enzyme to have reduced stability but the S108T enzyme to have increased stability. We conclude that P. falciparum can bear highly host-specific drug-resistant polymorphisms, most likely reflecting different selective pressures found in humans and mosquitoes. Thus, it may be useful to sample both human and mosquito vector infections to accurately ascertain the epidemiological status of drug-resistant alleles. PMID:22065788

  14. The Drop That Spilled the Cup: Acute Myocardial Infarction in a Young Woman with Underlying Thrombophilic Polymorphisms and Oral Contraceptive Use

    PubMed Central

    Capilli, Gianfranco; Patané, Anella Antonietta

    2014-01-01

    We present the case of a 28-year-old woman who was admitted to our cardiology unit for acute coronary syndrome. Her history was notable for cardiovascular disease familiarity, active smoking, and oral contraceptive use. On further analysis, she was noted to have thrombophilic polymorphisms involving the plasminogen activator inhibitor (PAI), angiotensin-converting enzyme (ACE), and methylenetetrahydrofolate reductase (MTHFR) genes. We discuss the implications that these cofactors may have had in the genesis of the disease. PMID:25587456

  15. Survival and risk of relapse of acute lymphoblastic leukemia in a Mexican population is affected by dihydrofolate reductase gene polymorphisms

    PubMed Central

    GÓMEZ-GÓMEZ, YAZMÍN; ORGANISTA-NAVA, JORGE; SAAVEDRA-HERRERA, MÓNICA VIRGINIA; RIVERA-RAMÍREZ, ANA BERTHA; TERÁN-PORCAYO, MARCO ANTONIO; DEL CARMEN ALARCÓN-ROMERO, LUZ; ILLADES-AGUIAR, BERENICE; LEYVA-VÁZQUEZ, MARCO ANTONIO

    2012-01-01

    Dihydrofolate reductase (DHFR) is the major target of methotrexate, a key component in childhood acute lymphoblastic leukemia (ALL) treatment. Polymorphisms in the gene coding for DHFR have been associated with adverse event treatment. This study evaluated the effect of the -A317G and C829T polymorphisms in the DHFR gene on survival and risk of relapse of ALL. Seventy patients with ALL and 100 healthy individuals were genotyped by the polymerase chain reaction-restriction fragment length polymorphism method. An association between the polymorphisms and the risk of relapse was found (p<0.05); patients with the -317G/G genotype were found to have an 8.55 (95% CI 1.84–39.70) higher chance of relapse and carriers of the 829T/T genotype had a 14.0 (95% CI 1.13–172.63) higher chance of relapse. Other variables, such as age and leukocyte count, were associated (p<0.05) with the risk of relapse of the disease. Individuals with the G/G and T/T genotype of the -A317G and C829T polymorphisms had poorer survival compared to other genotype groups (log-rank test; p<0.05). Although preliminary, these data seem to suggest a role for the DHFR polymorphisms in the risk of relapse of ALL and the mortality risk in these patients. PMID:22969948

  16. Adaptive developmental plasticity in methylene tetrahydrofolate reductase (MTHFR) C677T polymorphism limits its frequency in South Indians.

    PubMed

    Naushad, Shaik Mohammad; Krishnaprasad, Chintakindi; Devi, Akella Radha Rama

    2014-05-01

    Methylene tetrahydrofolate reductase (MTHFR) C677T polymorphism shows considerable heterogeneity in its distribution in humans worldwide. The current study was conducted to investigate whether this polymorphism exhibited adaptive developmental plasticity in the control of the TT-genotype frequency. We screened 1,818 South Indian subjects (895 males and 923 females) for MTHFR C677T polymorphism using PCR-restriction fragment length polymorphism approach. MTHFR 677T-allele frequency in males and females was 9.1 and 11.0%, respectively. Compared to females, males had lower frequency of TT-genotype [odds ratio 0.31, 95% confidence interval (CI) 0.08-1.01]. The frequency of MTHFR 677T-allele was highest in the age group of 20-40 years and it gradually decreased from 40-60 to 60-80 years (P trend<0.0001). MTHFR 677TT-genotype was associated with 7.02-folds (95% CI: 2.12-25.63, P<0.0001) cumulative risk for recurrent pregnancy loss (RPL), neural tube defects (NTDs) and deep vein thrombosis (DVT). Linear regression model suggested that male gender exhibited increased homocysteine levels by 9.35 μmol/L while each MTHFR 677T-allele contributed to 4.63 μmol/L increase in homocysteine. Plasma homocysteine showed inverse correlation with dietary folate (r=-0.17, P<0.0001), B2 (r=-0.14, P<0.0001) and B6 (r=-0.07, P=0.03). Examination of the spontaneously aborted fetuses (n=35) showed no significant association of fetal genotype on its in utero viability. From the current study, it was concluded that C677T seemed to have acquired adaptive developmental plasticity among South Indians due to environmental influences thus contributing to hyperhomocysteinemia and its associated complications such as RPL, NTDs, DVT, etc.

  17. Polymorphisms in folate-related enzyme genes in idiopathic infertile Brazilian men.

    PubMed

    Gava, Marcello M; Kayaki, Erika A; Bianco, Bianca; Teles, Juliana S; Christofolini, Denise M; Pompeo, Antonio C L; Glina, Sidney; Barbosa, Caio P

    2011-12-01

    The aim of the study was to analyze the distribution of the methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), and methionine synthase (MTR) polymorphisms in idiopathic infertile Brazilian men and fertile men. Case-control study comprising 133 idiopathic infertile Brazilian men with nonobstructive azoospermia ([NOA] n = 55) or severe oligozoospermia ([SO] n = 78) and 173 fertile men as controls. MTHFR C677T, A1298C, and G1793A; MTRR A66G; and MTR A2756G polymorphisms were studied by quantitative polymerase chain reaction (qPCR). The results were analyzed statistically and a P value <.05 was considered significant. Single-marker analysis revealed a significant association among MTHFR C677T polymorphism and both NOA group (P = .018) and SO group (P < .001). Considering the MTHFR A1298C, MTHFR G1793A, and MTRR A66G polymorphisms, no difference was found between NOA group and SO group. Regarding the MTR A2756G polymorphism, a significant difference was found between NOA and controls, P = .017. However, statistical analysis revealed no association between SO group and controls. Combined genotypes of 3 MTHFR polymorphisms did not identify a haplotype associated with idiopathic infertility. The combinatory analysis of the 3 polymorphisms MTHFR, MTRR, and MTR did not show difference between cases and controls. The findings suggest the MTHFR C677T and MTR A2756G polymorphisms could be an important genetic factor predisposing to idiopathic infertility in Brazilian men.

  18. Analysis of Polymorphisms in Genes (AGT, MTHFR, GPIIIa, and GSTP1) Associated with Hypertension, Thrombophilia and Oxidative Stress in Mestizo and Amerindian Populations of México

    PubMed Central

    Juárez-Velázquez, Rocio; Canto, Patricia; Canto-Cetina, Thelma; Rangel-Villalobos, Hector; Rosas-Vargas, Haydee; Rodríguez, Maricela; Canizales-Quinteros, Samuel; Velázquez Wong, Ana Claudia; Ordoñez-Razo, Rosa María; Vilchis-Dorantes, Guadalupe; Coral-Vázquez, Ramón Mauricio

    2010-01-01

    Several polymorphisms related to hypertension, thrombophilia, and oxidative stress has been associated with the development of cardiovascular disease. We analyzed the frequency of M235T angiotensinogen (AGT), A222V 5,10 methylenete-trahydrofolate reductase (MTHFR), L33P glycoprotein IIIa (GPIIIa), and I105V glutathione S-transferase P1 (GSTP1) polymorphisms in 285 individuals belonging to Mexican-Mestizo and five Amerindian population from México, by real time PCR allelic discrimination. Allele and genotype frequencies were compared using χ2 tests. All populations followed the Hardy Weinberg equilibrium for assay markers with the exception of the Triki, whose were in Hardy Weinberg dysequilibrium for the glutathione S-transferase P1 polymorphism. Interestingly, according to all the analyzed single nucleotide polymorphisms (SNPs), the Triki population was the most differentiated and homogeneous group of the six populations analyzed. A comparison of our data with those previously published for some Caucasian, Asian and Black populations showed quite significant differences. These differences were remarkable with all the Mexican populations having a lower frequency of the 105V allele of the glutathione S-transferase P1 and reduced occurrence of the 222A allele of the 5,10 methylenetetrahydrofolate reductase. Our results show the genetic diversity among different Mexican populations and with other racial groups. PMID:20592457

  19. Real-Time PCR for Dihydrofolate Reductase Gene Single-Nucleotide Polymorphisms in Plasmodium vivax Isolates

    PubMed Central

    Brega, Sara; de Monbrison, Frédérique; Severini, Carlo; Udomsangpetch, Rachanee; Sutanto, Inge; Ruckert, Paul; Peyron, François; Picot, Stéphane

    2004-01-01

    Mutations in the dhfr gene of Plasmodium vivax (pvdhfr) are associated with resistance to the antifolate antimalarial drugs. Polymorphisms in the pvdhfr gene were assessed by hybridization probe technology on the LightCycler instrument with 134 P. vivax-infected blood samples from Turkey (n = 24), Azerbaijan (n = 39), Thailand (n = 16), Indonesia (n = 53), and travelers (n = 19). Double mutations (S58R and S117N) or quadruple mutations (F57L/I, S58R, T61M, and S117N) in the pvdhfr genes were found in all Thai samples (100%). pvdhfr mutant-type alleles were significantly more common in samples from travelers (42%) than in those from patients from Indonesia (5%). Surprisingly, the pvdhfr single-mutation allele (S117N) was identified at a high frequency in parasites from Turkey and Azerbaijan (71 and 36%, respectively), where sulfadoxine-pyrimethamine is not recommended for the treatment of P. vivax malaria by the World Health Organization and the Malaria National Programs. PMID:15215112

  20. Quinone Reductase 2 Is a Catechol Quinone Reductase

    SciTech Connect

    Fu, Yue; Buryanovskyy, Leonid; Zhang, Zhongtao

    2008-09-05

    The functions of quinone reductase 2 have eluded researchers for decades even though a genetic polymorphism is associated with various neurological disorders. Employing enzymatic studies using adrenochrome as a substrate, we show that quinone reductase 2 is specific for the reduction of adrenochrome, whereas quinone reductase 1 shows no activity. We also solved the crystal structure of quinone reductase 2 in complexes with dopamine and adrenochrome, two compounds that are structurally related to catecholamine quinones. Detailed structural analyses delineate the mechanism of quinone reductase 2 specificity toward catechol quinones in comparison with quinone reductase 1; a side-chain rotational difference between quinone reductase 1 and quinone reductase 2 of a single residue, phenylalanine 106, determines the specificity of enzymatic activities. These results infer functional differences between two homologous enzymes and indicate that quinone reductase 2 could play important roles in the regulation of catecholamine oxidation processes that may be involved in the etiology of Parkinson disease.

  1. MTHFR polymorphisms in childhood acute lymphoblastic leukemia: influence on methotrexate therapy

    PubMed Central

    Umerez, Maitane; Gutierrez-Camino, Ángela; Muñoz-Maldonado, Carmen; Martin-Guerrero, Idoia; Garcia-Orad, Africa

    2017-01-01

    Methotrexate (MTX) is an important component in the therapy used to treat childhood acute lymphoblastic leukemia (ALL). Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme for MTX pharmacokinetics. Two single-nucleotide polymorphisms in MTHFR gene, C677T and A1298C, affecting MTHFR activity, have been widely studied as potential markers of MTX toxicity and/or outcome in pediatric ALL. In this review, we show that the majority of published reports do not find association or present opposite effect. Therefore, MTHFR C677T and A1298C polymorphisms do not seem to be good markers of MTX-related toxicity and/or outcome in pediatric ALL. The efforts should be focused on other genes, such as transporter genes or microRNA-related genes. PMID:28392709

  2. A variety of gene polymorphisms associated with idiopathic granulomatous mastitis

    PubMed Central

    Destek, Sebahattin; Gul, Vahit Onur; Ahioglu, Serkan

    2016-01-01

    Idiopathic granulomatous mastitis (IGM) is a rare and chronic inflammatory disorder. IGM mimics breast cancer regarding its clinical and radiological features. Etiology of IGM remains unclarified. Our patient was 37-year-old and 14 weeks pregnant. There was pain, redness and swelling in the right breast. The mass suggestive of malignancy was detected in sonography. Serum CA 125 and CA 15-3 levels were high. Genetic analysis was performed for the etiology. methylenetetrahydrofolate reductase (MTHFR) C 677 TT, β-fibrinogen-455 G>A, plasminogen activator inhibitor (PAI)-1 5 G/5 G, angiotensin-converting enzyme (ACE) I/D mutation was found. IGM was diagnosed by cor biopsy. An association was also reported between breast cancer and mutations in MTHFR-C 677 T, PAI-1, ACE genes. Genetic polymorphisms may involve in the development of IGM as it was seen in our case. Further studies should be conducted to better clarify this plausible association. PMID:27619324

  3. Genetic polymorphisms involved in folate metabolism and elevated plasma concentrations of homocysteine: maternal risk factors for Down syndrome in Brazil.

    PubMed

    Biselli, J M; Goloni-Bertollo, E M; Zampieri, B L; Haddad, R; Eberlin, M N; Pavarino-Bertelli, E C

    2008-01-22

    The aim of the present study was to investigate the effect of polymorphisms C677T and A1298C in the methylenetetrahydrofolate reductase (MTHFR) gene, A2756G in methionine synthase reductase (MTR) gene and A80G in reduced folate carrier 1 (RFC1) gene, and plasma homocysteine (Hcy), on the maternal risk for Down syndrome (DS). Seventy-two DS mothers and 194 mothers who had no children with DS were evaluated. The investigation of the MTHFR C677T, MTR A2756G and RFC1 A80G polymorphisms was performed by polymerase chain reaction and enzyme digestion and the MTHFR A1298C polymorphism by allele-specific polymerase chain reaction. Hcy quantification was carried out by liquid chromatography-tandem mass spectrometry. The median number of polymorphic alleles for the four loci tested was greater in DS mothers compared to the control group, and the presence of three or more polymorphic alleles increased the risk for having a child with DS 1.74 times. Elevated maternal risk for DS was also observed when plasma Hcy concentration was higher than 4.99 micromol/L. In conclusion, the presence of three or more polymorphic alleles for MTHFR C677T, MTHFR A1298C, MTR A2756G, and RFC1 A80G, and plasma Hcy concentrations higher than 4.99 micromol/L are maternal risk factors for DS.

  4. Susceptibility to diabetic neuropathy in patients with insulin dependent diabetes mellitus is associated with a polymorphism at the 5' end of the aldose reductase gene

    PubMed Central

    Heesom, A.; Millward, A.; Demaine, A.

    1998-01-01

    OBJECTIVES—There is evidence that the polyol pathway is involved in the pathogenesis of diabetic neuropathy. Aldose reductase (ALR2) is the first and rate limiting enzyme of this pathway and recent studies have suggested that polymorphisms in and around the gene are associated with the development of diabetic microvascular disease. The aim was to examine the role of ALR2 in the susceptibility to diabetic neuropathy in patients with insulin dependent diabetes mellitus (IDDM).
METHODS—One hundred and fifty nine British white patients with IDDM and 102 normal healthy controls were studied using the polymerase chain reaction to test for a highly polymorphic microsatellite marker 2.1 kilobase (kb) upstream of the initiation site of the ALR2 gene.
RESULTS—Seven alleles were detected (Z-6, Z-4, Z-2, Z, Z+2, Z+4, and Z+6). There was a highly significant decrease in the frequency of the Z+2 allele in those patients with overt neuropathy compared with those with no neuropathy after 20 years duration of diabetes (14.1% v 38.2%, χ2 =17.3, p<0.00001). A similar difference was also found between the neuropathy group and those patients who have had diabetes for< five years with no overt neuropathy (14.1% v 30.2%, χ2=9.0, p<0.0025). The neuropathy group also had a significant decrease in the frequency of the Z/Z+2 genotype compared with those patients who have no neuropathy after 20 years duration of diabetes (14.0% v 44.7%, χ2=13.0, p<0.0005).
CONCLUSION—These results suggest that the aldose reductase gene is intimately involved in the pathogenesis of diabetic neuropathy.

 PMID:9489533

  5. Lack of association between the methylenetetrahydropholate reductase gene A1298C polymorphism and neural tube defects in a Turkish study group.

    PubMed

    Yildiz, S H; Ozdemir Erdogan, M; Solak, M; Eser, O; Arıkan Terzi, E S; Eser, B; Kocabaş, V; Aslan, A

    2016-06-03

    The etiology underlying neural tube defects (NTDs) is not fully understood and is believed to involve a complex milieu of genetic and environmental factors. The A1298C polymorphism in the methylenetetrahydropholate reductase gene (MTHFR) has been associated with mild risk for NTDs. In this study, the genotype distribution of the MTHFR gene A1298C polymorphism and the levels of serum homocysteine, vitamin B12, and folate were evaluated in 33 children with NTDs, their mothers, and 46 healthy controls. Genotyping of the A1298C polymorphism was performed by real-time polymerase chain reaction. The A and C allele frequencies in children with NTDs and their mothers were similar to controls (P = 0.160). The 1298AA and 1298CC genotype frequencies (P = 0.551 and 0.062, respectively) in children with NTDs and their mothers did not differ from controls. On the other hand, the 1298AC genotype frequencies in children with NTDs and their mothers were significantly different from controls (P = 0.025). The genotype frequency of 1298AC was lower in children with NTDs than in controls. There was no significant association between clinical distribution of NTDs and 1298AA/AC/CC genotypes (P > 0.05). Serum vitamin B12 levels were higher in children with NTDs than their mothers and controls (P = 0.001). There were no differences among serum homocysteine and folate levels in all groups (P = 0.494 and 0.141, respectively). Both genetic and nutritional factors are important in the etiology of NTDs. Thus, the A1298C polymorphism cannot be regarded as a major risk factor for NTDs.

  6. A 19-base pair deletion polymorphism in dihydrofolate reductase is associated with increased unmetabolized folic acid in plasma and decreased red blood cell folate.

    PubMed

    Kalmbach, Renee D; Choumenkovitch, Silvina F; Troen, Aron P; Jacques, Paul F; D'Agostino, Ralph; Selhub, Jacob

    2008-12-01

    Dihydrofolate reductase (DHFR) catalyzes the reduction of folic acid to tetrahydrofolate (THF). A 19-bp noncoding deletion allele maps to intron 1, beginning 60 bases from the splice donor site, and has been implicated in neural tube defects and cancer, presumably by influencing folate metabolism. The functional impact of this polymorphism has not yet been demonstrated. The objective of this research was to determine the effects of the DHFR mutation with respect to folate status and assess influence of folic acid intake on these relations. The relationship between DHFR genotype and plasma concentrations of circulating folic acid, total folate, total homocysteine, and concentrations of RBC folate was determined in 1215 subjects from the Framingham Offspring Study. There was a significant interaction between DHFR genotype and folic acid intake with respect to the prevalence of high circulating unmetabolized folic acid (defined as >85th percentile). Folic acid intake of >or=500 microg/d increased the prevalence of high circulating unmetabolized folic acid in subjects with the deletion (del/del genotype (47.0%) compared with the wild type (WT)/del (21.4%) and wild type (WT)/WT genotypes (24.4%) (P for interaction = 0.03). Interaction between the DHFR polymorphism and folic acid intake was also seen with respect to RBC folate (P for interaction = 0.01). When folic acid intake was <250 microg/d, the del/del genotype was associated with significantly lower RBC folate (732.3 nmol/L) compared with the WT/WT genotype (844.4 nmol/L). Our results suggest the del/del polymorphism in DHFR is a functional polymorphism, because it limits assimilation of folic acid into cellular folate stores at high and low folic acid intakes.

  7. Association of methionine synthase rs1801394 and methionine synthase reductase rs1805087 polymorphisms with meningioma in adults: A meta-analysis

    PubMed Central

    ZENG, XIAN-TAO; LU, JUN-TI; TANG, XIANG-JUN; WENG, HONG; LUO, JIE

    2014-01-01

    Several epidemiological studies suggested that methionine synthase (MTRR) rs1801394 and methionine synthase reductase (MTR) rs1805087 polymorphisms may be involved in the risk of meningioma in adults; however, the results from different case-control studies have been inconsistent. Therefore, we performed a meta-analysis to investigate the association of MTRR and MTR polymorphisms with meningioma. PubMed, Web of Knowledge, China National Knowledge Infrastructure and Wanfang databases were searched up to October 30, 2013 and 3 publications, involving 7 case-control studies, were finally included. Following data extraction, a meta-analysis was conducted using Stata 12.0 software. The pooled results based on the fixed effects model demonstrated that the MTRR rs1801394 polymorphism was associated with an increased risk of meningioma [odds ratio (OR)=1.18, 95% confidence interval (CI): 1.05–1.32 for G vs. A; OR=1.41, 95% CI: 1.12–1.77 for GG vs. AA; OR=1.08, 95% CI: 0.94–1.33 for AG vs. AA; OR=1.19, 95% CI: 1.01–1.40 for (AG+GG) vs. AA; and OR=1.32, 95% CI: 1.07–1.63 for GG vs. (AG+AA)]; however, an association between the MTR rs1805087 polymorphism and the risk of meningioma was not identified [OR=0.99, 95% CI: 0.88–1.12 for G vs. A; OR=1.09, 95% CI: 0.80–1.48 for GG vs. AA; OR=0.95, 95% CI: 0.82–1.11 for AG vs. AA; OR=0.97, 95% CI: 0.84–1.13 for (AG+GG) vs. AA; and OR=1.09, 95% CI: 0.80–1.48 for GG vs. (AG+AA)]. Therefore, the currently available evidence suggests that the MTRR rs1801394 polymorphism may increase the risk of meningioma, whereas the MTRR rs1801394 polymorphism is not associated with meningioma. PMID:24748989

  8. One-carbon metabolism-related gene polymorphisms and risk of head and neck squamous cell carcinoma: case-control study.

    PubMed

    Suzuki, Takeshi; Matsuo, Keitaro; Hasegawa, Yasuhisa; Hiraki, Akio; Wakai, Kenji; Hirose, Kaoru; Saito, Toshiko; Sato, Shigeki; Ueda, Ryuzo; Tajima, Kazuo

    2007-09-01

    Low consumption of vegetables and fruits, which leads to insufficient folate intake, is associated with increased risk of several types of cancer, including head and neck squamous cell carcinoma (HNSCC). Functional polymorphisms in genes encoding one-carbon metabolism enzymes, such as methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), methionine synthase (MTR A2756G), methionine synthase reductase (MTRR A66G) and thymidylate synthase (TS), influence folate metabolism and thus might impact on HNSCC risk. We conducted a case-control study with 237 HNSCC cases newly and histologically diagnosed and 711 age- and sex-matched non-cancer controls to clarify associations with these five polymorphisms. Gene-environment interactions between polymorphisms and smoking and drinking habit and folate consumption were also evaluated by logistic regression analysis. Dietary folate intake was inversely associated with HNSCC risk. None of the polymorphisms showed any significant impact on HNSCC risk by genotype alone, but we found interactions between drinking habit and MTHFR C667T (P = 0.04), MTR A2756G (P = 0.04) and MTRR A66G (P = 0.03) polymorphisms. The results suggest that there may be interactions between one-carbon metabolism-related polymorphisms and alcohol drinking for HNSCC risk.

  9. Genetic polymorphisms in one-carbon metabolism: associations with CpG island methylator phenotype (CIMP) in colon cancer and the modifying effects of diet

    PubMed Central

    Curtin, Karen; Slattery, Martha L.; Ulrich, Cornelia M.; Bigler, Jeannette; Levin, Theodore R.; Wolff, Roger K.; Albertsen, Hans; Potter, John D.; Samowitz, Wade S.

    2008-01-01

    This study investigated associations between CpG island methylator phenotype (CIMP) colon cancer and genetic polymorphisms relevant to one-carbon metabolism and thus, potentially the provision of methyl groups and risk of colon cancer. Data from a large, population-based case–control study (916 incident colon cancer cases and 1972 matched controls) were used. Candidate polymorphisms in methylenetetrahydrofolate reductase (MTHFR), thymidylate synthase (TS), transcobalamin II (TCNII), methionine synthase (MTR), reduced folate carrier (RFC), methylene-tetrahydrofolate dehydrogenase 1 (MTHFD1), dihydrofolate reductase (DHFR) and alcohol dehydrogenase 3 (ADH3) were evaluated. CIMP− or CIMP+ phenotype was based on five CpG island markers: MINT1, MINT2, MINT31, p16 and MLH1. The influence of specific dietary factors (folate, methionine, vitamin B12 and alcohol) on these associations was also analyzed. We hypothesized that polymorphisms involved in the provision of methyl groups would be associated with CIMP+ tumors (two or more of five markers methylated), potentially modified by diet. Few associations specific to CIMP+ tumors were observed overall, which does not support the hypothesis that the provision of methyl groups is important in defining a methylator phenotype. However, our data suggest that genetic polymorphisms in MTHFR 1298A > C, interacting with diet, may be involved in the development of highly CpG-methylated colon cancers. AC and CC genotypes in conjunction with a high-risk dietary pattern (low folate and methionine intake and high alcohol use) were associated with CIMP+ (OR = 2.1, 95% CI = 1.3–3.4 versus AA/high risk; P-interaction = 0.03). These results provide only limited support for a role of polymorphisms in one-carbon metabolism in the etiology of CIMP colon cancer. PMID:17449906

  10. Combined effect of polymorphisms in type III 5-α reductase and androgen receptor gene with the risk of benign prostatic hyperplasia in Korea

    PubMed Central

    Lee, Chung Lyul; Lee, Jaegeun; Na, Yong Gil; Song, Ki Hak

    2016-01-01

    We evaluated whether type III 5-alpha reductase (SRD5A3; steroid reductase 5-alpha 3) polymorphism was associated with susceptibility of benign prostate hyperplasia (BPH) and the combined effects in BPH risk between the type of short tandem repeat (STR) in SRD5A3 and the length of trinucleotide (CAG) repeats in androgen receptor (AR) gene. We compared the length of AC repeats in STR region of SRD5A3 gene and a CAG repeat in AR in 188 BPH patients who underwent transurethral resection of prostate (TURP) and 98 controls by polymerase chain reaction-based methods. We defined short type was less than 21 copies of AC repeats. The odds ratio for BPH between the men with at least one of short type and with both large types of STR in SRD5A3 gene was 3.10 (95% confidence interval [CI], 1.87–5.16; P=0.000). And BPH was 2.35 times more likely to occur in with less than 23 copies of CAG repeats than men equal or greater than 23 copies in AR gene (95% CI, 1.18–2.36; P=0.016). The men with the large type of STR and ≥23 copies of CAG repeats have 5.3 times BPH risk compared to the reference group with the at least one of the short type of STR and <23 copies (P<0.000). In conclusion, these results suggest that shorter AC repeats of SRD5A3 gene and shorter CAG repeats of AR gene were associated with an increased risk for BPH. However, the interaction between above two factors was not affected in risk of BPH. PMID:27807533

  11. "Polymorphisms in folate metabolism genes as maternal risk factor for neural tube defects: an updated meta-analysis".

    PubMed

    Yadav, Upendra; Kumar, Pradeep; Yadav, Sushil Kumar; Mishra, Om Prakash; Rai, Vandana

    2015-02-01

    Epidemiological studies have evaluated the association between maternal methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C and methionine synthase reductase (MTRR) A66G polymorphisms and risk of neural tube defects (NTDs) in offspring. However, the results from the published studies on the association between these three polymorphisms and NTD risk are conflicting. To derive a clearer picture of association between these three maternal polymorphisms and risk of NTD, we performed meta-analysis. A comprehensive search was conducted to identify all case-control studies of maternal MTHFR and MTRR polymorphisms and NTD risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Overall, we found that maternal MTHFR C677T polymorphism (OR(TvsC) =1.20; 95% CI = 1.13-1.28) and MTRR A66G polymorphism (OR(GvsA) = 1.21; 95% CI = 0.98-1.49) were risk factors for producing offspring with NTD but maternal MTHFR A1298C polymorphism (OR(CvsA) = 0.91; 95% CI = 0.78-1.07) was not associated with NTD risk. However, in stratified analysis by geographical regions, we found that the maternal C677T polymorphism was significantly associated with the risk of NTD in Asian (OR(TvsC) = 1.43; 95% CI: 1.05-1.94), European (OR(TvsC) = 1.13; 95% CI: 1.04-1.24) and American (OR(TvsC) = 1.26; 95% CI: 1.13-1.41) populations. In conclusion, present meta-analysis supports that the maternal MTHFR C677T and MTRR A66G are polymorphisms contributory to risk for NTD.

  12. Association of MTHFR C677T and A1298C polymorphisms with non-Hodgkin lymphoma susceptibility: Evidence from a meta-analysis

    PubMed Central

    He, Jing; Liao, Xiao-Yu; Zhu, Jin-Hong; Xue, Wen-Qiong; Shen, Guo-Ping; Huang, Shao-Yi; Chen, Wei; Jia, Wei-Hua

    2014-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism and DNA synthesis. A number of studies have examined the association of MTHFR C677T and A1298C polymorphisms with non-Hodgkin lymphoma (NHL) susceptibility; however, the conclusions were contradictory. We searched available publications assessing the polymorphisms of MTHFR and NHL susceptibility from MEDLINE, EMBASE and CBM. Genotype-based mRNA expression analysis was performed using data from 270 individuals with three different ethnicities. Ultimately, a total of 7448 cases and 11146 controls from 25 studies were included for the C677T polymorphism, 6173 cases and 9725 controls from 19 studies for the A1298C polymorphism. Pooled results indicated that neither C677T nor A1298C polymorphism was associated with NHL susceptibility. However, C677T polymorphism showed a statistically significantly increased risk for Caucasians, but a decreased risk for Asians in the subgroup analysis by ethnicity. The same variants may confer increased susceptibility to develop follicular lymphoma (FL). Moreover, A1298C polymorphism was associated with increased NHL risk for Asians. This meta-analysis indicated that C677T polymorphism was associated with altered NHL susceptibility for Caucasians, Asians and FL. Increased NHL risk was also shown for A1298C among Asians. These findings warrant validation in large and well-designed prospective studies. PMID:25146845

  13. Association between C677T Polymorphism of Methylene Tetrahydrofolate Reductase and Congenital Heart Disease: Meta-Analysis of 7,697 Cases and 13,125 Controls

    PubMed Central

    Mamasoula, Chrysovalanto; Prentice, R. Reid; Pierscionek, Tomasz; Pangilinan, Faith; Mills, James L.; Druschel, Charlotte; Pass, Kenneth; Russell, Mark W.; Hall, Darroch; Töpf, Ana; Brown, Danielle L.; Zelenika, Diana; Bentham, Jamie; Cosgrove, Catherine; Bhattacharya, Shoumo; Riveron, Javier Granados; Setchfield, Kerry; Brook, J. David; Bu'Lock, Frances A.; Thornborough, Chris; Rahman, Thahira J.; Doza, Julian Palomino; Tan, Huay L.; O'Sullivan, John; Stuart, A. Graham; Blue, Gillian; Winlaw, David; Postma, Alex V.; Mulder, Barbara J.M.; Zwinderman, Aelko H.; van Engelen, Klaartje; Moorman, Antoon F.M.; Rauch, Anita; Gewillig, Marc; Breckpot, Jeroen; Devriendt, Koen; Lathrop, G. Mark; Farrall, Martin; Goodship, Judith A.; Cordell, Heather J.; Brody, Lawrence C.; Keavney, Bernard D.

    2013-01-01

    Background Association between the C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene and congenital heart disease (CHD) is contentious. Methods and Results We compared genotypes between CHD cases and controls, and between mothers of CHD cases and controls. We placed our results in context by conducting metaanalyses of previously published studies. Among 5,814 cases with primary genotype data and 10,056 controls, there was no evidence of association between MTHFR C677T genotype and CHD risk (OR 0.96 [95% CI 0.87-1.07]). A random-effects meta-analysis of all studies (involving 7,697 cases and 13,125 controls) suggested the presence of association (OR 1.25 [95% CI 1.03-1.51]; p=0.022), but with substantial heterogeneity among contributing studies (I2=64.4%), and evidence of publication bias. Meta-analysis of large studies only (defined by a variance of the log OR less than 0.05), which together contributed 83% of all cases, yielded no evidence of association (OR 0.97 [95% CI 0.91-1.03]), without significant heterogeneity (I2=0). Moreover, meta-analysis of 1,781 mothers of CHD cases (829 of whom were genotyped in this study) and 19,861 controls revealed no evidence of association between maternal C677T genotype and risk of CHD in offspring (OR 1.13 [95% CI 0.87-1.47]). There was no significant association between MTHFR genotype and CHD risk in large studies from regions with different levels of dietary folate. Conclusions The MTHFR C677T polymorphism, which directly influences plasma folate levels, is not associated with CHD risk. Publication biases appear to substantially contaminate the literature with regard to this genetic association. PMID:23876493

  14. C677T (RS1801133 ) MTHFR gene polymorphism frequency in a colombian population

    PubMed Central

    Gómez-Gutierrez, Alberto; Gómez, Piedad Elena; Casas-Gomez, Maria Consuelo; Briceño, Ignacio

    2015-01-01

    Introduction: Abnormal levels of the enzyme methylenetetrahydrofolate reductase (MTHFR) are associated with an increased risk of both cardiovascular and cerebrovascular disease and higher concentrations of homocysteine. Abnormal levels are also related to birth defects, pregnancy complications, cancer and toxicity to methotrexate (MTX). Polymorphisms of MTHFR affect the activity of the enzyme. Genetic associations have been related to treatment efficacy. Objective: To establish the frequency of the C> T polymorphism at nucleotide 677 of the MTHFR gene in a group of Colombian individuals. Methods: Data from pharmacogenetic microarrays that include MTX sensibility-associated polymorphisms were retrospectively collected (Pathway Genomics®). The frequency of the C> T MTHFR rs1801133 marker polymorphism was analyzed. Results: Microarray data from 68 men and 84 women were analyzed. Comparisons of genotype C/C vs. C/T and T/T were statistically significantly different (p= 0.00, p= 0.026, respectively), as were C/T and T / T (p= 0.0001). Conclusions: Results for the C/C and C/T genotypes in a Colombian population are similar to other previously studied groups of healthy subjects. Subjects from our population might be at risk of developing diseases associated with MTHFR polymorphisms and might present toxicity and adverse effects if treated with MTX, which suggests the need to evaluate therapeutic alternatives based on individual pharmacogenetic studies. PMID:26309343

  15. Associations of MTHFR C677T and MTRR A66G Gene Polymorphisms with Metabolic Syndrome: A Case-Control Study in Northern China

    PubMed Central

    Yang, Boyi; Fan, Shujun; Zhi, Xueyuan; Wang, Da; Li, Yongfang; Wang, Yinuo; Wang, Yanxun; Wei, Jian; Zheng, Quanmei; Sun, Guifan

    2014-01-01

    Prior evidence indicates that homocysteine plays a role in the development of metabolic syndrome (MetS). Methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms are common genetic determinants of homocysteine levels. To investigate the associations of the MTHFR C677T and MTRR A66G polymorphisms with MetS, 692 Chinese Han subjects with MetS and 878 controls were recruited. The component traits of MetS and the MTHFR C677T and MTRR A66G genotypes were determined. A significant association was observed between the MTHFR 677T allele and increased risk of MetS, high fasting blood glucose, high waist circumference, and increasing number of MetS components. The MTRR A66G polymorphism was associated with an increased risk of MetS when combined with the MTHFR 677TT genotype, although there was no association found between MetS and MTRR A66G alone. Furthermore, the MTRR 66GG genotype was associated with high fasting blood glucose and triglycerides. Our data suggest that the MTHFR 677T allele may contribute to an increased risk of MetS in the northern Chinese Han population. The MTRR A66G polymorphism is not associated with MetS. However, it may exacerbate the effect of the MTHFR C677T variant alone. Further large prospective population-based studies are required to confirm our findings. PMID:25429430

  16. Dihydrofolate reductase 19-bp deletion polymorphism modifies the association of folate status with memory in a cross-sectional multi-ethnic study of adults123

    PubMed Central

    Philip, Dana; Buch, Assaf; Moorthy, Denish; Scott, Tammy M; Parnell, Laurence D; Lai, Chao-Qiang; Ordovás, José M; Selhub, Jacob; Rosenberg, Irwin H; Tucker, Katherine L; Troen, Aron M

    2015-01-01

    Background: Folate status has been positively associated with cognitive function in many studies; however, some studies have observed associations of poor cognitive outcomes with high folate. In search of an explanation, we hypothesized that the association of folate with cognition would be modified by the interaction of high-folate status with a common 19-bp deletion polymorphism in the dihydrofolate reductase (DHFR) gene. To our knowledge, the cognitive effects of this gene have not been studied previously. Objective: We examined the association between cognitive outcomes with the 19-bp deletion DHFR polymorphism, folate status, and their interaction with high or normal plasma folate. Design: This was a pooled cross-sectional study of the following 2 Boston-based cohorts of community living adults: the Boston Puerto Rican Health Study and the Nutrition, Aging, and Memory in Elders study. Individuals were genotyped for the DHFR 19-bp deletion genotype, and plasma folate status was determined. Cognitive outcomes included the Mini-Mental State Examination, Center for Epidemiologic Studies Depression Scale, and factor scores for the domains of memory, executive function, and attention from a set of cognitive tests. Results: The prevalence of the homozygous deletion (del/del) genotype was 23%. In a multivariable analysis, high folate status (>17.8 ng/mL) was associated with better memory scores than was normal-folate status (fourth–fifth quintiles compared with first–third quintiles: β ± SE = −0.22 ± 0.06, P < 0.01). Carriers of the DHFR del/del genotype had worse memory scores (β ± SE = −0.24 ± 0.10, P < 0.05) and worse executive scores (β = −0.19, P < 0.05) than did those with the del/ins and ins/ins genotypes. Finally, we observed an interaction such that carriers of the del/del genotype with high folate had significantly worse memory scores than those of both noncarriers with high-folate and del/del carriers with normal-folate (β-interaction = 0

  17. Anthracycline-Related Cardiomyopathy After Childhood Cancer: Role of Polymorphisms in Carbonyl Reductase Genes—A Report From the Children's Oncology Group

    PubMed Central

    Blanco, Javier G.; Sun, Can-Lan; Landier, Wendy; Chen, Lu; Esparza-Duran, Diego; Leisenring, Wendy; Mays, Allison; Friedman, Debra L.; Ginsberg, Jill P.; Hudson, Melissa M.; Neglia, Joseph P.; Oeffinger, Kevin C.; Ritchey, A. Kim; Villaluna, Doojduen; Relling, Mary V.; Bhatia, Smita

    2012-01-01

    Purpose Carbonyl reductases (CBRs) catalyze reduction of anthracyclines to cardiotoxic alcohol metabolites. Polymorphisms in CBR1 and CBR3 influence synthesis of these metabolites. We examined whether single nucleotide polymorphisms in CBR1 (CBR1 1096G>A) and/or CBR3 (CBR3 V244M) modified the dose-dependent risk of anthracycline-related cardiomyopathy in childhood cancer survivors. Patients and Methods One hundred seventy survivors with cardiomyopathy (patient cases) were compared with 317 survivors with no cardiomyopathy (controls; matched on cancer diagnosis, year of diagnosis, length of follow-up, and race/ethnicity) using conditional logistic regression techniques. Results A dose-dependent association was observed between cumulative anthracycline exposure and cardiomyopathy risk (0 mg/m2: reference; 1 to 100 mg/m2: odds ratio [OR], 1.65; 101 to 150 mg/m2: OR, 3.85; 151 to 200 mg/m2: OR, 3.69; 201 to 250 mg/m2: OR, 7.23; 251 to 300 mg/m2: OR, 23.47; > 300 mg/m2: OR, 27.59; Ptrend < .001). Among individuals carrying the variant A allele (CBR1:GA/AA and/or CBR3:GA/AA), exposure to low- to moderate-dose anthracyclines (1 to 250 mg/m2) did not increase the risk of cardiomyopathy. Among individuals with CBR3 V244M homozygous G genotypes (CBR3:GG), exposure to low- to moderate-dose anthracyclines increased cardiomyopathy risk when compared with individuals with CBR3:GA/AA genotypes unexposed to anthracyclines (OR, 5.48; P = .003), as well as exposed to low- to moderate-dose anthracyclines (OR, 3.30; P = .006). High-dose anthracyclines (> 250 mg/m2) were associated with increased cardiomyopathy risk, irrespective of CBR genotype status. Conclusion This study demonstrates increased anthracycline-related cardiomyopathy risk at doses as low as 101 to 150 mg/m2. Homozygosis for G allele in CBR3 contributes to increased cardiomyopathy risk associated with low- to moderate-dose anthracyclines, such that there seems to be no safe dose for patients homozygous for the CBR3 V244

  18. A Study on MTHFR C677T Gene Polymorphism and Alcohol Dependence among Meiteis of Manipur, India.

    PubMed

    Singh, Huidrom Suraj; Salam, Kabita; Saraswathy, Kallur Nava

    2014-01-01

    Chronic alcohol consumption is reported to be associated with increase in plasma homocysteine levels which is further influenced by the polymorphism in methylenetetrahydrofolate reductase (MTHFR) gene. The present study aims to understand the extent of the MTHFR C677T polymorphism in alcohol dependent (AD) cases of Meiteis of Manipur, a Mendelian population of India. MTHFR C677T polymorphism was screened in 313 controls and 139 alcohol dependent (AD) cases who all met DSM-IV criteria for alcohol dependence. Both AD cases and controls were unrelated up to 1st cousin. Among the control group, different drinking patterns like abstainer/nondrinkers (NDs), occasional drinkers (ODs), and moderate drinkers (MDs) are included. Both the groups were found to be in Hardy-Weinberg equilibrium (P > 0.05). Genotypic and allelic frequency distribution of MTHFR C677T polymorphism did not differ significantly between AD cases and controls (P > 0.05). However, individuals carrying mutant (T) allele show more than 1-fold increased risk for AD though not significant (OR = 1.43; 95% CI 0.41-5.01, P > 0.05). In conclusion, MTHFR C677T polymorphism is not found to be risk marker for AD in present studied population. However, higher prevalence of the mutant T allele may exacerbate deleterious health risk in future especially among alcohol drinkers.

  19. Association of MTHFR C677T polymorphism with loneliness but not depression in cognitively normal elderly males.

    PubMed

    Lan, Wen-Hsuan; Yang, Albert C; Hwang, Jen-Ping; Hong, Chen-Jee; Liou, Ying-Jay; Yeh, Heng-Liang; Liu, Mu-En; Tsai, Shih-Jen

    2012-07-11

    Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is involved in folate and homocysteine metabolism, and has been associated with geriatric disorders, including dementia and late-life depression. The present work aimed to investigate the effect of MTHFR C677T polymorphism on the presence of depression and loneliness in cognitively normal male subjects. A total of 323 cognitively normal male subjects were included in this study (mean age=80.6; SD=5.3). Depression was assessed by the Geriatric Depression Scale-Short Form (GDS-SF) and loneliness by UCLA loneliness scales. Analysis of variance (ANOVA) was used to test the between MTHFR genotype difference in depression and loneliness. Multiple regression was used to test the effect of MTHFR polymorphism on the loneliness, controlling for age, education, cognitive function, and depression. ANOVA showed a significant between-genotype difference in loneliness scores (P=0.015), and post hoc comparisons showed that subjects with C/C genotype had significantly higher loneliness ratings, compared to those with C/T or T/T genotype. Regression analysis indicated that the effect of MTHFR polymorphism on loneliness was independent of age, education, cognitive function, and depression. Our findings suggest that MTHFR C677T polymorphism may be linked more to loneliness than depression in the cognitively normal elderly males, and may be implicated in the pathophysiology of late-life depression in relation to MTHFR genes.

  20. Epistasis Between Polymorphisms in COMT, ESR1, and GCH1 Influences COMT Enzyme Activity and Pain

    PubMed Central

    Smith, Shad B.; Reenilä, Ilkka; Männistö, Pekka T.; Slade, Gary D.; Maixner, William; Diatchenko, Luda; Nackley, Andrea G.

    2014-01-01

    Abnormalities in the enzymatic activity of catechol-O-methyltransferase (COMT) contribute to chronic pain conditions, such as temporomandibular disorders (TMD). Thus, we sought to determine the effects of polymorphisms in COMT and functionally-related pain genes in the COMT pathway (estrogen receptor 1: ESR1, guanosine-5-triphosphate cyclohydrolase 1: GCH1, methylenetetrahydrofolate reductase: MTHFR) on COMT enzymatic activity, musculoskeletal pain, and pain-related intermediate phenotypes among TMD cases and healthy controls. Results demonstrate that the COMT rs4680 (val158met) polymorphism is most strongly associated with outcome measures, such that individuals with the minor A allele (met) exhibit reduced COMT activity, increased TMD risk, and increased musculoskeletal pain. Epistatic interactions were observed between the COMT rs4680 polymorphism and polymorphisms in GCH1 and ESR1. Among individuals with the COMT met allele, those with two copies of the GCH1 rs10483639 minor G allele exhibit normalized COMT activity and increased mechanical pain thresholds. Among individuals with the COMT val allele, those with two copies of the ESR1 rs3020377 minor A allele exhibit reduced COMT activity, increased bodily pain, and poorer self-reported health. These data reveal that the GCH1 minor G allele confers a protective advantage among met carriers, while the ESR1 minor A allele is disadvantageous among val carriers. Furthermore, these data suggest that the ability to predict the downstream effects of genetic variation on COMT activity is critically important to understanding the molecular basis of chronic pain conditions. PMID:25218601

  1. Epistasis between polymorphisms in COMT, ESR1, and GCH1 influences COMT enzyme activity and pain.

    PubMed

    Smith, Shad B; Reenilä, Ilkka; Männistö, Pekka T; Slade, Gary D; Maixner, William; Diatchenko, Luda; Nackley, Andrea G

    2014-11-01

    Abnormalities in the enzymatic activity of catechol-O-methyltransferase (COMT) contribute to chronic pain conditions, such as temporomandibular disorders (TMD). Thus, we sought to determine the effects of polymorphisms in COMT and functionally related pain genes in the COMT pathway (estrogen receptor 1 [ESR1], guanosine-5-triphosphate cyclohydrolase 1 [GCH1], methylenetetrahydrofolate reductase [MTHFR]) on COMT enzymatic activity, musculoskeletal pain, and pain-related intermediate phenotypes among TMD cases and healthy control subjects. Results show that the COMT rs4680 (val(158)met) polymorphism is most strongly associated with outcome measures, such that individuals with the minor A allele (met) exhibit reduced COMT activity, increased TMD risk, and increased musculoskeletal pain. Epistatic interactions were observed between the COMT rs4680 polymorphism and polymorphisms in GCH1 and ESR1. Among individuals with the COMT met allele, those with 2 copies of the GCH1 rs10483639 minor G allele exhibit normalized COMT activity and increased mechanical pain thresholds. Among individuals with the COMT val allele, those with 2 copies of the ESR1 rs3020377 minor A allele exhibit reduced COMT activity, increased bodily pain, and poorer self-reported health. These data reveal that the GCH1 minor G allele confers a protective advantage among met carriers, whereas the ESR1 minor A allele is disadvantageous among val carriers. Furthermore, these data suggest that the ability to predict the downstream effects of genetic variation on COMT activity is critically important to understanding the molecular basis of chronic pain conditions.

  2. Association of MTHFR C677T and A1298C polymorphisms with oral cancer susceptibility: evidence from a meta-analysis

    PubMed Central

    Jiang, Sui; Xu, Jin-Dong; Zhuo, Zhen-Jian; Hua, Zhu-Ming

    2017-01-01

    Methylenetetrahydrofolate reductase (MTHFR) is a central enzyme involved in folate metabolism and plays an important role in DNA synthesis and methylation. Several studies have been conducted to illustrate the associations between MTHFR C677T and A1298C polymorphisms with oral cancer susceptibility; however, the results are inconsistent. Therefore, we conducted an updated meta-analysis to obtain a more reliable estimation of the associations. We retrieved eligible studies from PubMed, EMBASE, and CBM databases through September 2016. Ultimately, pooled analyses involved 10 studies with 1443 cases and 1640 controls for the C677T polymorphism, as well as five studies with 973 cases and 1024 controls for the A1298C polymorphism. Risk estimates were presented as odds ratios (ORs) and 95% confidence intervals (95% CIs). Pooled results indicated that neither C677T nor A1298C polymorphism was associated with oral cancer susceptibility. However, a borderline significant association was detected between MTHFR C677T polymorphism and a decreased oral cancer risk (homozygous model: OR=0.71, 95% CI=0.50–1.00) in hospital-based studies. Our results suggested that MTHFR C677T and A1298C polymorphisms might not be associated with oral cancer risk. However, more evidence is needed to further confirm these findings in the future. PMID:28138253

  3. Risk of prostate cancer and thrombosis-related factor polymorphisms

    PubMed Central

    GHASEMI, SOMAYEHSADAT; TAVAKOLI, AYDIN; MOGHADAM, MOHAMAD; ZARGAR, MOHAMAD ALI; ABBASPOUR, MARYAM; HATAMNEJADIAN, NASIM; EBRAHIMI, AHMAD

    2014-01-01

    Venous thromboembolism (VTE) is a complication commonly encountered in cancer patients and is considered to be a major cause of morbidity and mortality. The genetic polymorphisms of thrombophilic factors in cancer patients have been focused on during the last few years. However, the number of available studies on the association between prostate cancer and thromboembolic diseases is limited. Prostate cancer is one of the four major types of cancer and its development is affected by a variety of environmental and genetic factors. In the present study we aimed to focus on the effects of thromboembolic factor gene variations on the risk of prostate cancer. In order to conduct our prospective study, we used amplification-refractory mutation system-polymerase chain reaction to investigate three polymorphisms [factor V Leiden (FVL) G1691A, factor II (prothrombin, PTH) G20210A and methylenetetrahydrofolate reductase (MTHFR) C677T] in prostate cancer patients, via comparison with normal individuals. The results demonstrated no significant differences in FVL and PTH gene variations between cases and controls (P>0.05). Although some cases with the T allele of MTHFR 677 were identified, no significant solidarity was established by statistical analysis (P>0.05). Therefore, non-genetic factors that may disturb homeostatic balance should also be considered in future studies, in order to determine the exact association between VTE and prostate cancer. PMID:24649068

  4. MTHFR C677 T gene polymorphism in lymphoproliferative diseases.

    PubMed

    Deligezer, Ugur; Akisik, Ebru E; Yaman, Fulya; Erten, Nilgün; Dalay, Nejat

    2006-01-01

    Methylenetetrahydrofolate reductase (MTHFR), a key enzyme in folate metabolism, has been implicated in cancer risk. In the present study we used a melting curve analysis to investigate the association of the common MTHFR C677 T polymorphism with lymphoproliferative diseases. Patients (n=117) were compared with age- and sex-matched control subjects (n=154). Our results indicate that the 677 T variant occurred less frequently in patients (26%) than in the control group (33.7%; P=0.05). Investigation of the variant allele (677 T) frequency in the subgroups with Hodgkin's lymphoma (HL) and B-cell neoplasms (BCNs) revealed that this difference was a result of the significantly lower distribution of the variant allele in patients with HL (20.5%; P=0.01). This was accompanied by a significantly higher frequency of the homozygote normal genotype (677CC) among the patients with HL. In patients with BCNs the distribution of the variant allele (30.3%) was comparable to that in the control group (P=0.47). However, the difference between HL (20.5%) and BCNs (30.3%) did not reach statistical significance (P=0.09). Our results suggest that the distribution of the C677 T polymorphism may vary among lymphoproliferative diseases.

  5. The effect of MTHFR C677T polymorphism on type 2 diabetes mellitus with vascular complications in Chinese Han population: a meta-analysis.

    PubMed

    Zhang, Dan; Zhou, Yijun; Han, Lingling; Ji, Hongmei; Li, Jia

    2014-01-01

    Methylenetetrahydrofolate reductase plays an important role in folate metabolism. Individuals who are type 2 diabetes mellitus have greatest risk for the development of vascular complications. The results of studies which assessed the association between MTHFR C677T polymorphism and T2DM with vascular complications were inconsistent in the Chinese Han population. The purpose of this meta-analysis was to assess the associations between MTHFR C677T polymorphism and T2DM with vascular complications in the Chinese Han population. We collected all relevant articles on MTHFR C677T polymorphisms and T2DM with vascular complications in the Chinese Han population in multiple electronic databases which were searched to December 2013. Fixed-effects and random-effects meta-analyses were performed to assess the odds ratios (ORs). Stratified Analysis, sensitivity Analysis and publication bias were examined. A total of 1984 diabetic patients with vascular complications and 1703 single diabetic patients were found in meta-analysis. There was a significant association between MTHFR C677T polymorphisms and T2DM with vascular complications under recessive genetic model, dominant genetic model, homozygous genetic model, heterozygous genetic model and allele comparison. Sensitivity analysis indicated that the overall result was dependable. Our meta-analysis suggests the MTHFR C677T polymorphisms is associated with T2DM with vascular complications in the Chinese Han population.

  6. Dietary consumption of B vitamins, maternal MTHFR polymorphisms and risk for spontaneous abortion

    PubMed Central

    Rodríguez-Guillén, María del Rosario; Torres-Sánchez, Luisa; Chen, Jia; Galván-Portillo, Marcia; Silva-Zolezzi, Irma; Blanco-Muñoz, Julia; Hernández-Valero, María A.; López-Carrillo, Lizbeth

    2010-01-01

    Objective To asses he association between intake of folate and B vitamins and the incidence of spontaneous abortion (SA) according to the maternal methylenetetrahydrofolate reductase (MTHFR) polymorphisms (677 C>T and 1298 A>C). Material and Methods We conducted a nested case-control study within a perinatal cohort of women recruited in the state of Morelos, Mexico. Twenty-three women with SA were compared to 74 women whose pregnancy survived beyond week 20th. Intake of folate and B vitamins respectively, was estimated using a validated food frequency questionnaire. Maternal MTHFR polymorphisms were determined by PCR-RFLP and serum homocysteine levels by HPLC. Results Carriers of MTHFR 677TT and 1298AC genotypes respectively showed an increased risk of SA (OR 677TT vs. CC/CT=5.0; 95% CI: 1.2, 20.9 and OR 1298 AC vs. AA=5.5; 95% CI: 1.1, 26.6). Conclusions Our results support the role of MTHFR polymorphisms as a risk factor for SA, regardless of dietary intake of B vitamins. PMID:19180309

  7. Does the MTHFR A1298C Polymorphism Modulate the Cardiorespiratory Response to Training?

    PubMed

    Cięszczyk, Paweł; Zarębska, Aleksandra; Jastrzębski, Zbigniew; Sawczyn, Michał; Kozakiewicz-Drobnik, Izabela; Leońska-Duniec, Agata; Kaczmarczyk, Mariusz; Maciejewska-Skrendo, Agnieszka; Żmijewski, Piotr; Trybek, Grzegorz; Smółka, Wojciech; Pilch, Jan; Leźnicka, Katarzyna; Lulińska-Kuklik, Ewelina; Sawczuk, Marek; Massidda, Myosotis

    2016-12-01

    The 5,10-methylenetetrahydrofolate reductase gene (MTHFR) A1298C polymorphic variant is a candidate to explain the individual differences in trainability and response to exercise training. Therefore, the aim of the study was to verify whether the A1298C polymorphism influenced the aerobic and anaerobic performance as well as body and mass composition in young Polish women following low-high impact aerobic exercise training. Two hundred and one women aged 21 ± 1 years (range 19-24) were included in the study. All of them completed a 12-week exercise training program and were measured for selected somatic features, aerobic capacity and cardiorespiratory fitness indices as well as peak anaerobic power and anaerobic capacity, before and after the intervention. A mixed 2 x 2 ANOVA for 20 dependent variables grouped in three categories was conducted. No significant interaction of the genotype with training for body mass and body composition variables was observed. Although, there were three significant genotype x training interactions for maximal oxygen uptake variables, regardless of body mass i.e.: for VO2max (p < 0.05), HRmax (p < 0.0001) and HRAT/HRmax (p < 0.0001). Significantly greater improvement in VO2max was gained by the CC+AC group compared to the AA genotype group. The present results support the hypothesis that individual differences in trainability are at least in part determined by the genetic component and MTHFR A1298C seems to be one of the many polymorphisms involved.

  8. A 19-base pair deletion polymorphism in dihydrofolate reductase is associated with increased unmetabolized folic acid in plasma and decreased red blood cell folate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dihydrofolate reductase (DHFR) catalyzes the reduction of folic acid to tetrahydrofolate (THF). A 19-bp noncoding deletion allele maps to intron 1, beginning 60 bases from the splice donor site, and has been implicated in neural tube defects and cancer, presumably by influencing folate metabolism. T...

  9. MTHFR 677C>T Polymorphism and the Risk of Breast Cancer: Evidence from an Original Study and Pooled Data for 28031 Cases and 31880 Controls

    PubMed Central

    Sekhar, Deepa; Francis, Amirtharaj; Gupta, Nishi; Konwar, Rituraj; Kumar, Sandeep; Kumar, Surender; Thangaraj, Kumarasamy; Rajender, Singh

    2015-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) acts at an important metabolic point in the regulation of cellular methylation reaction. It assists in the conversion of 5, 10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. The latter aids in remethylation of homocysteine to de novo methionine that is required for DNA synthesis. The objective of this study was to examine the effect of MTHFR 677 C>T polymorphism on the risk of breast cancer in the Indian sub-continent. Methods and Results We genotyped 677 C>T locus in 1096 individuals that were classified into cases (N=588) and controls (N=508). Genotype data were analyzed using chi-square test. No significant difference was observed in the distribution of genotypes between cases and controls in north Indian (P = 0.932), south Indian (P = 0.865), and pooled data (P = 0.680). To develop a consensus regarding the impact of 677C>T polymorphism on breast cancer risk, we also conducted a meta-analysis on 28031 cases and 31880 controls that were pooled from sixty one studies. The overall summary estimate upon meta-analysis suggested no significant correlation between the 677C>T substitution and breast cancer in the dominant model (Fixed effect model: OR = 0.97, P=0.072, Random effects model: OR = 0.96, P = 0.084) or the recessive model (Fixed effect model: OR = 1.05, P = 0.089; Random effects model: OR= 1.08, P= 0.067). Conclusion 677 C>T substitution does not affect breast cancer risk in the Indo-European and Dravidian populations of India. Analysis on pooled data further ruled out association between the 677 C>T polymorphism and breast cancer. Therefore, 677 C>T substitution does not appear to influence the risk of breast cancer. PMID:25803740

  10. The effects of genomic polymorphisms in one-carbon metabolism pathways on survival of gastric cancer patients received fluorouracil-based adjuvant therapy

    PubMed Central

    Zhao, Tingting; Xu, Zhi; Gu, Dongying; Wu, Peng; Huo, Xinying; Wei, Xiaowei; Tang, Yongfei; Gong, Weida; He, Ming-Liang; Chen, Jinfei

    2016-01-01

    5-fluorouracil (5-FU) is widely used to treat patients with gastric cancer (GC). However, the response rate is quite heterogeneous. The single nucleotide polymorphisms (SNPs) and their interactions of genes in the one-carbon metabolism (OCM) pathway, including Methylenetetrahydrofolate reductase (MTHFR), Methionine synthase reductase (MTRR), Methionine synthase (MTR), and Thymidylate synthase (TS), significantly affect 5-FU metabolism. In this study, 650 stage II-III patients were recruited from 1998 to 2006. Among them, 251 received 5-FU treatment and other 399 patients were untreated. The Cox regression analysis, log-rank tests and Kaplan–Meier plots were adopted. In the chemotherapy cohort, MTRR 66 GA + GG genotypes decreased death risk, however, the protect effect of MTRR 66 GA + GG disappeared when GC patients simultaneously had MTHFR 677TT + TC or MTR 2756GG + GA genotypes. TS 5′-UTR 2R3R + 3R3R genotypes also prolonged overall survival of patients treated with 5-FU. And this favorable prognosis obviously enhanced when GC patients simultaneously had TS 3′-UTR DD + DI and TS 5′-UTR 2R3R + 3R3R genotypes. Our findings showed that the polymorphisms of MTRR 66 A > G and TS 5′-UTR 3R > 2R may be potential prognostic factors for GC patients receiving 5-FU. PMID:27456431

  11. Homocysteine Metabolism Gene Polymorphisms (MTHFR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G) Jointly Elevate the Risk of Folate Deficiency.

    PubMed

    Li, Wen-Xing; Dai, Shao-Xing; Zheng, Jun-Juan; Liu, Jia-Qian; Huang, Jing-Fei

    2015-08-10

    Folate deficiency is strongly associated with cardiovascular disease. We aimed to explore the joint effect of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase (MTR) A2756G, and methionine synthase reductase (MTRR) A66G polymorphisms on folate deficiency in a Chinese hypertensive population. A total of 480 subjects aged 28-75 were enrolled in this study from September 2005-December 2005 from six hospitals in different Chinese regions. Known genotypes were detected by PCR-RFLP methods and serum folate was measured by chemiluminescence immunoassay. Our results showed that MTHFR 677TT and MTR 2756AG + GG were independently associated with a higher risk of folate deficiency (TT vs. CC + CT, p < 0.001 and AG + GG vs. AA p = 0.030, respectively). However, the MTHFR A1298C mutation may confer protection by elevating the serum folate level (p = 0.025). Furthermore, patients carrying two or more risk genotypes showed higher odds of folate deficiency than null risk genotype carriers, especially those carrying four risk genotypes. These findings were verified by generalized multifactor dimensionality reduction (p = 0.0107) and a cumulative effects model (p = 0.001). The results of this study have shown that interactions among homocysteine metabolism gene polymorphisms lead to dramatic elevations in the folate deficiency risk.

  12. Homocysteine Metabolism Gene Polymorphisms (MTHFR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G) Jointly Elevate the Risk of Folate Deficiency

    PubMed Central

    Li, Wen-Xing; Dai, Shao-Xing; Zheng, Jun-Juan; Liu, Jia-Qian; Huang, Jing-Fei

    2015-01-01

    Folate deficiency is strongly associated with cardiovascular disease. We aimed to explore the joint effect of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase (MTR) A2756G, and methionine synthase reductase (MTRR) A66G polymorphisms on folate deficiency in a Chinese hypertensive population. A total of 480 subjects aged 28–75 were enrolled in this study from September 2005–December 2005 from six hospitals in different Chinese regions. Known genotypes were detected by PCR-RFLP methods and serum folate was measured by chemiluminescence immunoassay. Our results showed that MTHFR 677TT and MTR 2756AG + GG were independently associated with a higher risk of folate deficiency (TT vs. CC + CT, p < 0.001 and AG + GG vs. AA p = 0.030, respectively). However, the MTHFR A1298C mutation may confer protection by elevating the serum folate level (p = 0.025). Furthermore, patients carrying two or more risk genotypes showed higher odds of folate deficiency than null risk genotype carriers, especially those carrying four risk genotypes. These findings were verified by generalized multifactor dimensionality reduction (p = 0.0107) and a cumulative effects model (p = 0.001). The results of this study have shown that interactions among homocysteine metabolism gene polymorphisms lead to dramatic elevations in the folate deficiency risk. PMID:26266420

  13. The 844ins68 cystathionine beta-synthase and C677T MTHFR gene polymorphism and the vaso-occlusive event risk in sickle cell disease

    PubMed Central

    Alves Jacob, Maza; da Cunha Bastos, Celso; Regina Bonini-Domingos, Claudia

    2011-01-01

    Introduction Sickle cell disease (SCD) is an inflammatory condition with an increase in the adhesion of sickled erythrocytes, and it is a potential cause of vaso-occlusive episodes, an event related to clinical manifestations, morbidity and mortality. The cystathionine beta-synthase enzyme gene (CBS) and the methylenetetrahydrofolate reductase enzyme gene (MTHFR) are risk factors for thromboembolic disorders. This study evaluated the frequency of the 844ins68 CBS and C677T MTHFR gene polymorphisms and their possibility to be risk factors for vaso-occlusive crises. Material and methods In total 91 blood samples from SCD patients were studied by PCR-RFLP and PCR-allele-specific, for the SCD genotype confirmation and polymorphism identification. Results The presence of clinical manifestations related to vaso-occlusive crises were more frequent among patients with the Hb SS genotype (p = 0.007). The CBS enzyme gene was three times more frequent (p = 0.011) among patients with vaso-occlusive complications. The MTHFR gene mutation frequency showed no increased risk for vaso-occlusive crises in SCD patients (p = 0.193). The interaction between the two polymorphisms was evaluated in 12.08% of the SCD patients and doubled the vaso-occlusive disease risk (relative risk: 2.16). Conclusions We conclude that the presence of 844ins68 CBS and C677T MTHFR gene polymorphism was a risk factor for vaso-occlusive episodes in the SCD patients evaluated. PMID:22291740

  14. Homocysteine and the C677T Gene Polymorphism of Its Key Metabolic Enzyme MTHFR Are Risk Factors of Early Renal Damage in Hypertension in a Chinese Han Population

    PubMed Central

    Yun, Lin; Xu, Rui; Li, Guohua; Yao, Yucai; Li, Jiamin; Cong, Dehong; Xu, Xingshun; Zhang, Lihua

    2015-01-01

    Abstract The combined hyperhomocysteinemia condition is a feature of the Chinese hypertensive population. This study used the case-control method to investigate the association between plasma homocysteine and the C677T gene polymorphism of its key metabolic enzyme, 5, 10-methylenetetrahydrofolate reductase (MTHFR), and early renal damage in a hypertensive Chinese Han population. A total of 379 adult essential hypertensive patients were selected as the study subjects. The personal information, clinical indicators, and the C677T gene polymorphism of MTHFR were texted. This study used the urine microalbumin/urine creatinine ratio (UACR) as a grouping basis: the hypertension without renal damage group (NRD group) and the hypertension combined with early renal damage group (ERD group). Early renal damage in the Chinese hypertensive population was associated with body weight, systolic pressure, diastolic pressure, urea nitrogen, serum creatinine, cystatin C, uric acid, aldosterone, and glomerular filtration rate. The homocysteine level and the UACR in the TT genotype group were higher than those in the CC genotype group. The binary logistic regression analysis results showed that after sex and age were adjusted, the MTHFR C677T gene polymorphism was correlated with early renal damage in hypertension in both the recessive model and in the additive model. Plasma homocysteine and the C677T gene polymorphism of its key metabolic enzyme MTHFR might be independent risk factors of early renal damage in the hypertensive Chinese Han population. PMID:26717388

  15. Association between MTHFR C677T Polymorphism and Risk of Acute Lymphoblastic Leukemia: A Meta-Analysis Based on 51 Case-Control Studies

    PubMed Central

    Li, Su-yi; Ye, Jie-yu; Liang, En-yu; Zhou, Li-xia; Yang, Mo

    2015-01-01

    Background Studies and systematic reviews have reached inconsistent conclusions on the role of 5, 10-methylenetetrahydrofolate reductase (MTHFR) polymorphism C677T in acute lymphoblastic leukemia (ALL) risk. Material/Methods The present meta-analysis comprising of 51 case-control studies, including 7892 cases and 14 280 controls was performed to reevaluate the association between MTHFR C677T polymorphism and ALL risk. Results Statistical differences were found in the dominant model (TT+CT vs. CC, odd ratio (OR)=0.89, 95% CI, 0.79–1.00, P=0.04) and the CT vs. CC (OR=0.89, 95% CI, 0.80–1.00, P=0.05), but not in the allele contrast model (T vs. C, OR=0.92, 95% CI, 0.84–1.01, P=0.08), additive model (TT vs. CC, OR=0.87, 95% CI, 0.73–1.05, P=0.15), or recessive model (TT vs. CT+CC, OR=0.94, 95% CI, 0.81–1.10, P=0.44) in overall populations. In the subgroup analyses stratified by age (children and adults) and ethnicity (Asian and Caucasian), no significant associations between MTHFR C677T polymorphism and ALL risk were observed. Conclusions The current study found no sufficient evidence of a protective role of MTHFR C677T polymorphism in ALL susceptibility. PMID:25761797

  16. Screening of polymorphisms for MTHFR and DHFR genes in spina bifida children and their mothers

    NASA Astrophysics Data System (ADS)

    Husna, M. Z.; Endom, I.; Ibrahim, S.; Selvi, N. Amaramalar; Fakhrurazi, H.; Htwe, R. Ohnmar; Kanehaswari, Y.; Halim, A. R. Abdul; Wong, S. W.; Subashini, K.; Syahira, O. Nur; Aishah, S.

    2013-11-01

    Mechanism underlying the beneficial effect of folic acid supplementation in reducing the risk of neural tube defect is still not well understood. Current evidences show the involvement of folic acid metabolic gene's polymorphism as contributing factors that regulate this pathway. Therefore, the objective of this research was to determine the presence of C677T polymorphism for methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase (DHFR-19 bp deletion) genes between mother-children pairs of case and control. With the approval of UKMMC ethic committee, genomic DNA was extracted from one hundred and forty consented bloods. Polymerase chain reaction (PCR), PCR-RFLP (Restriction Fragment Length Polymorphism) and sequencing were employed to verify each nucleotide change. Our result shows that mutant MTHFR and DHFR alleles are present in all Malaysian sub-ethnic groups, case and control. Even though mutant MTHFR are found to be slightly higher in the case groups, 75% of the affected child is a non carrier for this allele and 62.5% of the mothers with an affected child are genotypically normal. For DHFR, almost all (87.5-100%) investigated samples are a carrier or having a double DHFR deletion be it a case or control pairs. However, strong maternal inheritance shown by the deleted allele might be due to a cascade effect of lacks of folate consumption or maternal uniparental disomy. In conclusion, the use of MTHFR and DHFR as markers in determining the risk of having spina bifida baby is uninformative and plays a small indirect role as the genetic causes of spina bifida. Therefore, spina bifida remains etiologically unknown polygenic and quantitative developmental trait whereby the searches for positive genetic marker need to be continued.

  17. Gene polymorphisms in folate metabolizing enzymes in adult acute lymphoblastic leukemia: effects on methotrexate-related toxicity and survival

    PubMed Central

    Ongaro, Alessia; De Mattei, Monica; Della Porta, Matteo Giovanni; Rigolin, GianMatteo; Ambrosio, Cristina; Di Raimondo, Francesco; Pellati, Agnese; Masieri, Federica Francesca; Caruso, Angelo; Catozzi, Linda; Gemmati, Donato

    2009-01-01

    Background The antifolate agent methotrexate is an important component of maintenance therapy in acute lymphoblastic leukemia, although methotrexate-related toxicity is often a reason for interruption of chemotherapy. Prediction of toxicity is difficult because of inter-individual variability susceptibility to antileukemic agents. Methotrexate interferes with folate metabolism leading to depletion of reduced folates. Design and Methods The aim of this study was to investigate the influence of polymorphisms for folate metabolizing enzymes with respect to toxicity and survival in adult patients with acute lymphoblastic leukemia treated with methotrexate maintenance therapy. To this purpose, we evaluated possible associations between genotype and hematologic and non-hematologic toxicity and effects on survival at 2 years of follow-up in patients with acute lymphoblastic leukemia. Results Polymorphisms in the genes encoding for methylenetetrahydrofolate reductase (MTHFR 677C>T) and in dihydrofolate reductase (DHFR 19 bp deletion) significantly increased the risk of hepatotoxicity in single (odds ratio 5.23, 95% confidence interval 1.13–21.95 and odds ratio 4.57, 95% confidence interval 1.01–20.77, respectively) and in combined analysis (odds ratio 6.82, 95% confidence interval 1.38–33.59). MTHFR 677C>T also increased the risk of leukopenia and gastrointestinal toxicity, whilst thymidylate synthase 28 bp repeat polymorphism increased the risk of anemia (odds ratio 8.48, 95% confidence interval 2.00–36.09). Finally, patients with MTHFR 677TT had a decreased overall survival rate (hazard ratio 2.37, 95% confidence interval 1.46–8.45). Conclusions Genotyping of folate polymorphisms might be useful in adult acute lymphoblastic leukemia to optimize methotrexate therapy, reducing the associated toxicity with possible effects on survival. PMID:19648163

  18. Thioredoxin reductase.

    PubMed Central

    Mustacich, D; Powis, G

    2000-01-01

    The mammalian thioredoxin reductases (TrxRs) are a family of selenium-containing pyridine nucleotide-disulphide oxidoreductases with mechanistic and sequence identity, including a conserved -Cys-Val-Asn-Val-Gly-Cys- redox catalytic site, to glutathione reductases. TrxRs catalyse the NADPH-dependent reduction of the redox protein thioredoxin (Trx), as well as of other endogenous and exogenous compounds. The broad substrate specificity of mammalian TrxRs is due to a second redox-active site, a C-terminal -Cys-SeCys- (where SeCys is selenocysteine), that is not found in glutathione reductase or Escherichia coli TrxR. There are currently two confirmed forms of mammalian TrxRs, TrxR1 and TrxR2, and it is possible that other forms will be identified. The availability of Se is a key factor determining TrxR activity both in cell culture and in vivo, and the mechanism(s) for the incorporation of Se into TrxRs, as well as the regulation of TrxR activity, have only recently begun to be investigated. The importance of Trx to many aspects of cell function make it likely that TrxRs also play a role in protection against oxidant injury, cell growth and transformation, and the recycling of ascorbate from its oxidized form. Since TrxRs are able to reduce a number of substrates other than Trx, it is likely that additional biological effects will be discovered for TrxR. Furthermore, inhibiting TrxR with drugs may lead to new treatments for human diseases such as cancer, AIDS and autoimmune diseases. PMID:10657232

  19. Meta-analysis of the association of MTHFR polymorphisms with multiple myeloma risk

    PubMed Central

    Ma, Li-Min; Ruan, Lin-Hai; Yang, Hai-Ping

    2015-01-01

    The association of methylenetetrahydrofolate reductase (MTHFR) polymorphisms with multiple myeloma (MM) risk has been explored, but the results remain controversial. Thus, a meta-analysis was performed to provide a comprehensively estimate. The case-control studies about MTHFR C677T and A1298C polymorphisms with MM risk were collected by searching PubMed, Elsevier, China National Knowledge Infrastructure and Wanfang Databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were applied to assess the strength of association. Overall, no significant association was found between MTHFR A1298C polymorphism and MM risk under all four genetic models (AC vs. AA, OR = 0.99, 95%CI = 0.82-1.20; CC vs. AA, OR = 1.14, 95%CI = 0.77-1.68; recessive model, OR = 1.10, 95%CI = 0.76-1.59; dominant model, OR = 1.01, 95%CI = 0.84-1.22). The risk was also not significantly altered for C677T polymorphism and MM in overall comparisons (CT vs. CC, OR = 1.04, 95%CI = 0.93-1.17; TT vs. CC, OR = 1.16, 95%CI = 0.98-1.37; recessive model, OR = 1.13, 95%CI = 0.98-1.32; dominant model, OR = 1.07, 95%CI = 0.96-1.20). In subgroup analyses by ethnicity, no significant association was observed in both Caucasians and Asians. This meta-analysis suggested that MTHFR polymorphisms were not associated with MM risk. PMID:26022785

  20. Folate and One-Carbon Metabolism Gene Polymorphisms and Their Associations With Oral Facial Clefts

    PubMed Central

    Boyles, Abee L.; Wilcox, Allen J.; Taylor, Jack A.; Meyer, Klaus; Fredriksen, Åse; Ueland, Per Magne; Drevon, Christian A.; Vollset, Stein Emil; Lie, Rolv Terje

    2008-01-01

    Folate metabolism plays a critical role in embryonic development. Prenatal folate supplementation reduces the risk of neural tube defects and probably oral facial clefts. Previous studies of related metabolic genes have associated polymorphisms in cystathionine-beta-synthase (CBS) and 5,10-methylenetetrahydrofolate reductase (MTHFR) with cleft risk. We explored associations between genes related to one-carbon metabolism and clefts in a Norwegian population-based study that included 362 families with cleft lip with or without cleft palate (CL/P) and 191 families with cleft palate only (CPO). We previously showed a 39% reduction in risk of CL/P with folic acid supplementation in this population. In the present study we genotyped 12 polymorphisms in nine genes related to one-carbon metabolism and looked for associations of clefting risk with fetal polymorphisms, maternal polymorphisms, as well as parent-of-origin effects, using combined likelihood-ratio tests (LRT). We also stratified by maternal periconceptional intake of folic acid (>400 μg) to explore gene-exposure interactions. We found a reduced risk of CL/P with mothers who carried the CBS C699T variant (rs234706); relative risk was 0.94 with one copy of the T allele (95% CI 0.63-1.4) and 0.50 (95% CI 0.26-0.96) with two copies (P = 0.008). We found no evidence of interaction of this variant with folate status. We saw no evidence of risk from the MTHFR C677T variant (rs1801133) either overall or after stratifying by maternal folate intake. No associations were found between any of the polymorphisms and CPO. Genetic variations in the nine metabolic genes examined here do not confer a substantial degree of risk for clefts. Published 2008 Wiley-Liss, Inc.† PMID:18203168

  1. Interaction of MTHFR C677T and A1298C, and MTR A2756G gene polymorphisms in breast cancer risk in a population in Northeast Brazil.

    PubMed

    de Cássia Carvalho Barbosa, Rita; da Costa, Débora Menezes; Cordeiro, Denise Ellen Francelino; Vieira, Ana Patricia Freitas; Rabenhorst, Silvia Helena Barem

    2012-11-01

    Polymorphisms in genes encoding enzymes of folate metabolism are a focus of breast cancer risk studies due of the role of these enzymes in DNA methylation, synthesis, and repair. MTHFR, encoding for 5,10-methylenetetrahydrofolate reductase, is one of the most studied genes in this regard, but findings are controversial, and the majority of studies have analyzed polymorphisms individually. In this case control study, we examined the combination of the polymorphisms MTHFR C677T and A1298C with MTR A2756G, where MTR, methionine synthase, is an important enzyme of the folate cycle in the methylation pathway. One hundred and forty-two patients with breast cancer and controls were included and the genotypes were determined using PCR-RFLP. In the population studied, individuals carrying the polymorphic allele in the heterozygous state for both enzymes, MTHFR C677T and MTR A2756G, had an increased risk [odds ratio, OR=2.77 (95% confidence interval, CI=1.19-6.52)] for disease, compared to those with the wild genotype. In addition, individuals carrying the MTR 2756 genotype AG had an increased risk when this was combined with the MTHFR 1298 genotype CC [OR=5.13 (95% CI=0.87-38.82)]. No significant results were found from the analyses associating the MTHFR C677T and A1298C genotypes. However, when stratifying the patients by age (50 years old as the cut-off), patients over 50 years old had greater risk, with the presence of both MTHFR polymorphisms in the heterozygous state [OR=5.33 (95% CI=1.42-21.03)]. This study points out the importance of the interactions between the MTHFR C677T, MTHFR A1298C and MTR A2756G polymorphisms, and also highlights the relevance of the MTR A2756G polymorphism and age in breast cancer risk.

  2. Association of Polymorphisms in BDNF, MTHFR, and Genes Involved in the Dopaminergic Pathway with Memory in a Healthy Chinese Population

    ERIC Educational Resources Information Center

    Yeh, Ting-Kuang; Hu, Chung-Yi; Yeh, Ting-Chi; Lin, Pei-Jung; Wu, Chung-Hsin; Lee, Po-Lei; Chang, Chun-Yen

    2012-01-01

    The contribution of genetic factors to the memory is widely acknowledged. Research suggests that these factors include genes involved in the dopaminergic pathway, as well as the genes for brain-derived neurotrophic factor (BDNF) and methylenetetrahydrofolate reductase (MTHFR). The activity of the products of these genes is affected by single…

  3. Maternal gene polymorphisms involved in folate metabolism and the risk of having a Down syndrome offspring: a meta-analysis.

    PubMed

    Yang, Mei; Gong, Tian; Lin, Xiaofang; Qi, Ling; Guo, Yiyang; Cao, Zhongqiang; Shen, Min; Du, Yukai

    2013-11-01

    Down syndrome (DS) is the most common chromosomal abnormality. Many studies have assessed the association between maternal gene polymorphisms involved in folate metabolism and the risk of having a DS offspring, but data are conflicting. Our study aimed to arrive at a more accurate estimation. Therefore, we carried out a meta-analysis of 26, 17, 9, 15, 9 and 6 case-control studies on the relationship between maternal methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase (MTR) A2756G, methionine synthase reductase (MTRR) A66G, reduced folate carrier 1 A80G and cystathionine β-synthase 844ins68 polymorphisms and the risk of having a DS offspring. The allele contrast and model-free approach were used. Results showed marginal significant associations for MTHFR C677T, overall [odds ratio (OR) = 1.28 (1.22, 1.46) and generalised odds ratio (ORG) = 1.35 (1.16, 1.57)] and in Caucasian [OR = 1.15 (1.03, 1.29) and ORG = 1.20 (1.04, 1.38)], Asian [OR = 1.68 (1.08, 2.63) and ORG = 1.74 (1.08, 2.80)] and Brazilian [OR = 1.22 (1.04, 1.43) and ORG = 1.28 (1.06, 1.55)] populations; for MTRR A66G, overall [OR = 1.22 (1.02, 1.46) and ORG = 1.31 (1.06, 1.62)]; and for RFC1 A80G, overall [OR = 1.16 (1.02, 1.31) and ORG = 1.18 (1.01, 1.37)]. MTHFR A1298C, MTR 12756G and CBS 844ins68 polymorphisms produced non-significant results. Since potential confounders could not be ruled out completely in this meta-analysis, further studies are needed to confirm these results.

  4. DNA promoter methylation in breast tumors: no association with genetic polymorphisms in MTHFR and MTR.

    PubMed

    Tao, Meng Hua; Shields, Peter G; Nie, Jing; Marian, Catalin; Ambrosone, Christine B; McCann, Susan E; Platek, Mary; Krishnan, Shiva S; Xie, Bin; Edge, Stephen B; Winston, Janet; Vito, Dominica; Trevisan, Maurizio; Freudenheim, Jo L

    2009-03-01

    Aberrant promoter methylation is recognized as an important feature of breast carcinogenesis. We hypothesized that genetic variation of genes for methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MTR), two critical enzymes in the one-carbon metabolism, may alter DNA methylation levels and thus influence DNA methylation in breast cancer. We evaluated case-control association of MTHFR C677T, A1298C, and MTR A2756G polymorphisms for cases strata-defined by promoter methylation status for each of three genes, E-cadherin, p16, and RAR-beta2 in breast cancer; in addition, we evaluated case-case comparisons of the likelihood of promoter methylation in relation to genotypes using a population-based case-control study conducted in Western New York State. Methylation was evaluated with real-time methylation-specific PCRs for 803 paraffin-embedded breast tumor tissues from women with primary, incident breast cancer. We applied unordered polytomous regression and unconditional logistic regression to derive adjusted odds ratios and 95% confidence intervals. We did not find any association of MTHFR and MTR polymorphisms with breast cancer risk stratified by methylation status nor between polymorphisms and likelihood of promoter methylation of any of the genes. There was no evidence of difference within strata defined by menopausal status, estrogen receptor status, folate intake, and lifetime alcohol consumption. Overall, we found no evidence that these common polymorphisms of the MTHFR and MTR genes are associated with promoter methylation of E-cadherin, p16, and RAR-beta2 genes in breast cancer.

  5. DNA promoter methylation in breast tumors: No association with genetic polymorphisms in MTHFR and MTR

    PubMed Central

    Tao, Meng Hua; Shields, Peter G.; Nie, Jing; Marian, Catalin; Ambrosone, Christine B.; McCann, Susan E.; Platek, Mary; Krishnan, Shiva S.; Xie, Bin; Edge, Stephen B.; Winston, Janet; Vito, Dominica; Trevisan, Maurizio; Freudenheim, Jo L.

    2013-01-01

    Aberrant promoter methylation is recognized as an important feature of breast carcinogenesis. We hypothesized that genetic variation of genes for methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MTR), two critical enzymes in one-carbon metabolism, may alter DNA methylation levels, and thus influence DNA methylation in breast cancer. We evaluated case-control association of MTHFR C677T, A1298C, and MTR A2756G polymorphisms for cases strata defined by promoter methylation status for each of three genes, E- cadherin, p16, and RAR-β2 in breast cancer; in addition, we evaluated case-case comparisons of likelihood of promoter methylation in relation to genotypes using a population-based case-control study conducted in Western New York State. Methylation was evaluated with real time methylation-specific PCRs for 803 paraffin embedded breast tumor tissues from women with primary, incident breast cancer. We applied unordered polytomous regression and unconditional logistic regression to derive adjusted odds ratios (OR) and 95% confidence intervals (CI). We did not find any association of MTHFR and MTR polymorphisms with breast cancer risk stratified by methylation status nor between polymorphisms and likelihood of promoter methylation of any of the genes. There was no evidence of difference within strata defined by menopausal status, ER status, folate intake and lifetime alcohol consumption. Overall, we found no evidence that these common polymorphisms of the MTHFR and MTR genes are associated with promoter methylation of E- cadherin, p16, and RAR-β2 genes in breast cancer. PMID:19240236

  6. Association of MTHFR (C677T) Gene Polymorphism With Breast Cancer in North India

    PubMed Central

    Waseem, Mohammad; Hussain, Syed Rizwan; Kumar, Shashank; Serajuddin, Mohammad; Mahdi, Farzana; Sonkar, Satyendra Kumar; Bansal, Cherry; Ahmad, Mohammad Kaleem

    2016-01-01

    BACKGROUND Breast cancer is one of the most common malignancies in women and is associated with a variety of risk factors. The functional single-nucleotide polymorphism (SNP) C677T in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR) may lead to decreased enzyme activity and affect the chemosensitivity of tumor cells. This study was designed to investigate the association of MTHFR gene polymorphism (SNP) in the pathogenesis of breast cancer among the North Indian women population. MATERIALS AND METHODS Genotyping was performed by polymerase chain reaction (PCR) using genomic DNA, extracted from the peripheral blood of subjects with (275 cases) or without (275 controls) breast cancer. Restriction fragment length polymorphism was used to study C677T polymorphism in the study groups. RESULTS The distribution of MTHFR (C677T) genotype frequencies, ie, CC, TT, and CT, among the patients was 64.7%, 2.18%, and 33.09%, respectively. In the healthy control group, the CC, TT, and CT frequencies were 78.91%, 1.09%, and 20.1%, respectively. The frequencies of C and T alleles were 81.2% and 18.7%, respectively, in the patient subjects, while they were 88.9% and 11.09%, respectively, among the healthy control group. Frequencies of the CT genotype and the T allele were significantly different (P = 0.007 and P = 0.005, respectively) between the control and the case subjects. CONCLUSION This study shows an association of the CT genotype and the T allele of the MTHFR (C667T) gene with increased genetic risk for breast cancer among Indian women. PMID:27721657

  7. Combined genotype and haplotype distributions of MTHFR C677T and A1298C polymorphisms

    PubMed Central

    Fan, Shujun; Yang, Boyi; Zhi, Xueyuan; Wang, Yanxun; Zheng, Quanmei; Sun, Guifan

    2016-01-01

    Abstract Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms are, independently and/or in combination, associated with many disorders. However, data on the combined genotype and haplotype distributions of the 2 polymorphisms in Chinese population were limited. We recruited 13,473 adult women from 9 Chinese provinces, collected buccal cell samples, and determined genotypes, to estimate the combined genotype and haplotype distributions of the MTHFR C677T and A1298C polymorphisms. In the total sample, the 6 common combined genotypes were CT/AA (29.5%), TT/AA (21.9%), CC/AA (15.4%), CC/AC (14.9%), CT/AC (13.7%), and CC/CC (3.4%); the 3 frequent haplotypes were 677T-1298A (43.6%), 677C-1298A (37.9%), and 677C-1298C (17.6%). Importantly, we observed that there were 51 (0.4%) individuals with the CT/CC genotype, 92 (0.7%) with the TT/AC genotype, 17 (0.1%) with the TT/CC genotype, and that the frequency of the 677T-1298C haplotype was 0.9%. In addition, the prevalence of some combined genotypes and haplotypes varied among populations residing in different areas and even showed apparent geographical gradients. Further linkage disequilibrium analysis showed that the D’ and r2 values were 0.883 and 0.143, respectively. In summary, the findings of our study provide further strong evidence that the MTHFR C677T and A1298C polymorphisms are usually in trans and occasionally in cis configurations. The frequencies of mutant genotype combinations were relatively higher in Chinese population than other populations, and showed geographical variations. These baseline data would be useful for future related studies and for developing health management programs. PMID:27902594

  8. MTHFR Gene Polymorphism-Mutations and Air Pollution as Risk Factors for Breast Cancer

    PubMed Central

    Gonzales, Mildred C.; Yu, Pojui; Shiao, S. Pamela K.

    2017-01-01

    Background The methylenetetrahydrofolate reductase gene (MTHFR) is one of the most investigated genes associated with breast cancer for its role in epigenetic pathways. Objectives The objectives of this metaprediction study were to examine the polymorphism-mutation risk subtypes of MTHFR and air pollution as contributing factors for breast cancer. Methods For triangulation purposes in metapredictive analyses, we used a recursive partition tree, nonlinear association curve fit, and heat maps for data visualization, in addition to the conventional comparison procedure and pooled analyses. Results We included 36,683 breast cancer cases and 40,689 controls across 82 studies for MTHFR 677 and 23,252 cases and 27,094 controls across 50 studies for MTHFR 1298. MTHFR 677 TT was a risk genotype for breast cancer (p = .0004) and in the East Asian subgroup (p = .005). On global maps, the most polymorphism-mutations on MTHFR 677 TT were found in the Middle East, Europe, Asia, and the Americas, whereas the most mutations on MTHFR 1298 CC were located in Europe and the Middle East for the control group. The geographic information system maps further revealed that MTHFR 677 TT mutations yielded a higher risk of breast cancer for Australia, East Asia, the Middle East, South Europe, Morocco, and the Americas and that MTHFR 1298 CC mutations yielded a higher risk in Asia, the Middle East, South Europe, and South America. Metapredictive analysis revealed that air pollution level was significantly associated with MTHFR 677 TT polymorphism-mutation genotype. Discussion We present the most comprehensive analyses to date of MTHFR polymorphism-mutations and breast cancer risk. Future nursing studies are needed to investigate the health impact on breast cancer of epigenetics and air pollution across populations. PMID:28114181

  9. MTHFR gene C677T mutation and ACE gene I/D polymorphism in Turkish patients with osteoarthritis.

    PubMed

    Inanir, Ahmet; Yigit, Serbulent; Tural, Sengul; Cecen, Osman; Yildirim, Eren

    2013-01-01

    Osteoarthritis is a degenerative joint disorder resulting in destruction of articular cartilage, osteophyte formation, and subchondral bone sclerosis. In recent years, numerous genetic factors have been identified and implicated in osteoarthritis. The aim of the current study was to examine the influence of methylenetetrahydrofolate reductase (MTHFR) gene C677T mutation and angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) variations on the risk of osteoarthritis. Genomic DNA is obtained from 421 persons (221 patients with osteoarthritis and 200 healthy controls). ACE gene I/D polymorphism genotypes were determined using polymerase chain reaction using I and D allele-specific primers. The MTHFR C677T mutation was analyzed by polymerase chain reaction (PCR) based restriction fragment length polymorphism (RFLP) methods. We found significant difference between the groups with respect to both ACE and MTHFR genotype distributions (p< 0.001, p< 0.001 respectively). Our study suggests that ACE gene DD genotype and MTHFR gene CC genotype could be used as genetic markers in osteoarthritis in Turkish study populations.

  10. Role of MTHFR C677T and MTR A2756G polymorphisms in thyroid and breast cancer development.

    PubMed

    Zara-Lopes, T; Gimenez-Martins, A P A; Nascimento-Filho, C H V; Castanhole-Nunes, M M U; Galbiatti-Dias, A L S; Padovani-Júnior, J A; Maniglia, J V; Francisco, J L E; Pavarino, E C; Goloni-Bertollo, E M

    2016-05-09

    Folate metabolism is essential for DNA synthesis and repair. Alterations in genes that participate in folate metabolism can be associated with several types of malignant neoplasms, including thyroid and breast cancer. In the present case-control study, we examined the association between methylenetetrahydrofolate reductase (MTHFR C677T, rs1801133) and methionine synthase (MTR A2756G, rs1805087) polymorphisms and risk for thyroid and breast cancer. Polymerase chain reaction-restriction fragment length technique was used to determine the specific genotypes in the genes of interest. Statistical analysis was performed by multiple logistic regression test. We found an association between MTHFR C677T polymorphism and risks to both thyroid (OR = 2.50; 95%CI = 1.15-5.46; P = 0.02) and breast cancer (OR = 2.53; 95%CI = 1.08-5.93; P = 0.03). Tobacco consumption and high body mass index were also associated with thyroid cancer. In addition, increased age (≥50 years) and alcohol consumption were found to be associated with breast cancer. Our results indicated that MTHFR C677T is significantly associated with thyroid and breast cancer risks. Thus, these factors may be used as potential prognostic markers for thyroid and breast cancers.

  11. Role of MTHFR C677T gene polymorphism in the susceptibility of schizophrenia: An updated meta-analysis.

    PubMed

    Yadav, Upendra; Kumar, Pradeep; Gupta, Sanjay; Rai, Vandana

    2016-04-01

    Methylenetetrahydrofolate reductase (MTHFR) is the key enzyme of folate/homocysteine metabolic pathway. C677T polymorphism of MTHFR gene was reported as risk factor for congenital defects, metabolic and neuropsychiatric disorders. Numerous case-control studies investigated C677T polymorphism as risk factor for schizophrenia but results of these studies were contradictory. To draw a conclusion, a meta-analysis of all available case-control studies was performed. PubMed, Google Scholar, Springer Link and Elsevier databases were searched for eligible case-control studies. Pooled odds ratio with 95%CI was used as an association measure and all statistical analyses were performed by Open Meta-Analyst and MIX software. Total 38 studies with 10,069 cases and 13,372 controls were included in the present meta-analysis. Results of meta-analysis showed significant associated between C677T polymorphism and risk of schizophrenia (ORTvsC=1.18, 95%CI=1.10-1.27, p=<0.001; ORCTvsCC=1.10, 95%CI=1.04-1.17, p=<0.001; ORTTvsCC=1.40, 95%CI=1.20-1.64, p=<0.001; ORTT+CTvsCC=1.19, 95%CI=1.09-1.30, p=<0.001). We also performed subgroup and sensitivity analyses. Subgroup analysis was done according to ethnicity and significant association was found between C677T polymorphism and risk of schizophrenia in all three ethnic populations-African (OR=2.51; 95%CI=1.86-3.40; p=<0.001), Asian (OR=1.21; 95%CI=1.10-1.33; p=<0.001) and Caucasian (OR=1.07; 95%CI=1.01-1.14; p=0.01). In conclusion the results of the present meta-analysis suggested that the MTHFR C677T polymorphism is a risk factor for schizophrenia.

  12. Homocysteine, methylenetetrahydrofolate reductase, folate status and atherothrombosis: A mechanistic and clinical perspective.

    PubMed

    Santilli, Francesca; Davì, Giovanni; Patrono, Carlo

    2016-03-01

    Observational studies consistently reported an association between plasma total homocysteine concentrations and the risk of vascular events. In contrast, data from randomized trials largely support the hypothesis that mild elevations in homocysteine level have a modest effect on cardiovascular risk. A substantial body of evidence suggests that platelet activation is, at least in part, a transducer of the effects of high homocysteine in promoting atherothrombosis. The larger treatment effect recorded in several supplementation trials by subjects not on antiplatelet agents may support this hypothesis and justify, at least in part, the success of folate therapy in primary prevention. Circulating folate and homocysteine levels as well as MTHFR genotype, while emerging as major predictors of the risk of vascular events and of the efficacy of folic acid therapy, have also proved to be determinants of an interindividual variability in the degree of lipid peroxidation and platelet activation, and of the extent of their downregulation by folic acid. This may justify a variability in folate requirements, to be further characterized with dose-finding studies using biochemical endpoints. The combination of low-dose aspirin and low-dose folate would appear to be ideally suited for the primary prevention of both coronary and cerebrovascular events, and additional clinical trials should assess the efficacy and safety of these agents.

  13. Association of the Maternal MTHFR C677T Polymorphism with Susceptibility to Neural Tube Defects in Offsprings: Evidence from 25 Case-Control Studies

    PubMed Central

    Zou, Peng; Ji, Guixiang; Gu, Aihua; Zhao, Peng

    2012-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme in folate metabolism and is involved in DNA methylation, DNA synthesis, and DNA repair. In addition, it is a possible risk factor in neural tube defects (NTDs). The association of the C677T polymorphism in the MTHFR gene and NTD susceptibility has been widely demonstrated, but the results remain inconclusive. In this study, we performed a meta-analysis with 2429 cases and 3570 controls to investigate the effect of the MTHFR C677T polymorphism on NTDs. Methods An electronic search of PubMed and Embase database for papers on the MTHFR C677T polymorphism and NTD risk was performed. All data were analysed with STATA (version 11). Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association. Sensitivity analysis, test of heterogeneity, cumulative meta-analysis, and assessment of bias were performed in our meta-analysis. Results A significant association between the MTHFR C677T polymorphism and NTD susceptibility was revealed in our meta-analysis ( TT versus CC: OR  = 2.022, 95% CI: 1.508, 2.712; CT+TT versus CC: OR  = 1.303, 95% CI: 1.089, 1.558; TT versus CC+CT: OR  = 1.716, 95% CI: 1.448, 2.033; 2TT+CT versus 2CC+CT: OR  = 1.330, 95% CI: 1.160, 1.525). Moreover, an increased NTD risk was found after stratification of the MTHFR C677T variant data by ethnicity and source of controls. Conclusion The results suggested the maternal MTHFR C677T polymorphism is a genetic risk factor for NTDs. Further functional studies to investigate folate-related gene polymorphisms, periconceptional multivitamin supplements, complex interactions, and the development of NTDs are warranted. PMID:23056169

  14. Molecular Cloning, Expression Pattern and Polymorphisms of NADPH-Cytochrome P450 Reductase in the Bird Cherry-Oat Aphid Rhopalosiphum padi (L.)

    PubMed Central

    Zuo, Yayun; Li, Yuting

    2016-01-01

    NADPH–cytochrome P450 reductase (CPR) plays an important role in the cytochrome P450 (CYP)-mediated metabolism of endogenous and exogenous substrates. CPR has been found to be associated with insecticide metabolism and resistance in many insects. However, information regarding CPR in the bird cherry-oat aphid, Rhopalosiphum padi, is unavailable. In the current study, a full-length cDNA (2,476 bp) of CPR (RpCPR) encoding 681 amino acids was cloned from R. padi. Nucleotide sequence and deduced amino acid sequence analysis showed that RpCPR exhibits characteristics of classical CPRs and shares high identities with those of other insects, especially with the pea aphid, Acyrthosiphon pisum. The mRNA of RpCPR was expressed at all developmental stages, with the highest expression level found in the second instar and the lowest in adult. Expression levels of RpCPR in isoprocarb-resistant and imidacloprid-resistant strains were 3.74- and 3.53-fold higher, respectively, than that of a susceptible strain. RpCPR expression could also be induced by low concentrations (LC30) of isoprocarb and imidacloprid. Moreover, we sequenced the open reading frame (ORF) of RpCPR from 167 field samples collected in 11 geographical populations. Three hundred and thirty-four SNPs were detected, of which, 65 were found in more than two individuals. One hundred and ninety-four missense mutations were present in the amino acid sequence, of which, the P484S mutant had an allele frequency of 35.1%. The present results suggest that RpCPR may play an important role in the P450-mediated insecticide resistance of R. padi to isoprocarb and imidacloprid and possibly other insecticides. Meanwhile, RpCPRmaintains high genetic diversity in natural individuals, which provides the possibility of studying potential correlations between variants and certain special physiological characters. PMID:27124302

  15. Dietary intake of folate, vitamin B2, vitamin B6, vitamin B12, genetic polymorphism of related enzymes, and risk of breast cancer: a case-control study in Japan.

    PubMed

    Ma, Enbo; Iwasaki, Motoki; Kobayashi, Minatsu; Kasuga, Yoshio; Yokoyama, Shiro; Onuma, Hiroshi; Nishimura, Hideki; Kusama, Ritsu; Tsugane, Shoichiro

    2009-01-01

    We investigated associations among intake of folate, vitamin B2, vitamin B6, vitamin B12, and polymorphisms of 5,10-methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MTR) genes and breast cancer risk in a Japanese population. A hospital based, case-control study was conducted in Nagano Prefecture, Japan, in 388 pairs of patients with histologically confirmed invasive breast cancer and age- and area-matched controls selected from medical checkup examinees. Energy-adjusted intakes of folate and other B vitamins were derived from a validated food frequency questionnaire. Genotyping was completed for MTHFR (C677T and A1298T) and MTR (A2756G). Odds ratios and 95% confidence intervals were calculated by the conditional logistical regression model. Median dietary folate intake (microg/day) in the control group was 438.2 (interquartile range: 354.9-542.9). Neither dietary intake of folate, vitamin B2, vitamin B6, or vitamin B12 nor polymorphisms of MTHFR or MTR genes were significantly associated with breast cancer risk. Further, no significant interaction was found among nutrients, polymorphisms, and breast cancer risk. Associations of nutrients with breast cancer risk did not differ by hormone receptors status. We conclude that dietary intake of folate and related B vitamins and genotypes of MTHFR or MTR have no overall association with breast cancer risk in Japanese women.

  16. Additive Interaction of MTHFR C677T and MTRR A66G Polymorphisms with Being Overweight/Obesity on the Risk of Type 2 Diabetes

    PubMed Central

    Zhi, Xueyuan; Yang, Boyi; Fan, Shujun; Li, Yongfang; He, Miao; Wang, Da; Wang, Yanxun; Wei, Jian; Zheng, Quanmei; Sun, Guifan

    2016-01-01

    Although both methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms have been associated with type 2 diabetes (T2D), their interactions with being overweight/obesity on T2D risk remain unclear. To evaluate the associations of the two polymorphisms with T2D and their interactions with being overweight/obesity on T2D risk, a case-control study of 180 T2D patients and 350 healthy controls was conducted in northern China. Additive interaction was estimated using relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S). After adjustments for age and gender, borderline significant associations of the MTHFR C677T and MTRR A66G polymorphisms with T2D were observed under recessive (OR = 1.43, 95% CI: 0.98–2.10) and dominant (OR = 1.43, 95% CI: 1.00–2.06) models, respectively. There was a significant interaction between the MTHFR 677TT genotype and being overweight/obesity on T2D risk (AP = 0.404, 95% CI: 0.047–0.761), in addition to the MTRR 66AG/GG genotypes (RERI = 1.703, 95% CI: 0.401–3.004; AP = 0.528, 95% CI: 0.223–0.834). Our findings suggest that individuals with the MTHFR 677TT or MTRR 66AG/GG genotypes are more susceptible to the detrimental effect of being overweight/obesity on T2D. Further large-scale studies are still needed to confirm our findings. PMID:27983710

  17. Does the MTHFR A1298C Polymorphism Modulate the Cardiorespiratory Response to Training?

    PubMed Central

    Zarębska, Aleksandra; Jastrzębski, Zbigniew; Sawczyn, Michał; Kozakiewicz-Drobnik, Izabela; Leońska-Duniec, Agata; Kaczmarczyk, Mariusz; Maciejewska-Skrendo, Agnieszka; Żmijewski, Piotr; Trybek, Grzegorz; Smółka, Wojciech; Pilch, Jan; Leźnicka, Katarzyna; Lulińska-Kuklik, Ewelina; Sawczuk, Marek; Massidda, Myosotis

    2016-01-01

    Abstract The 5,10-methylenetetrahydrofolate reductase gene (MTHFR) A1298C polymorphic variant is a candidate to explain the individual differences in trainability and response to exercise training. Therefore, the aim of the study was to verify whether the A1298C polymorphism influenced the aerobic and anaerobic performance as well as body and mass composition in young Polish women following low-high impact aerobic exercise training. Two hundred and one women aged 21 ± 1 years (range 19–24) were included in the study. All of them completed a 12-week exercise training program and were measured for selected somatic features, aerobic capacity and cardiorespiratory fitness indices as well as peak anaerobic power and anaerobic capacity, before and after the intervention. A mixed 2 x 2 ANOVA for 20 dependent variables grouped in three categories was conducted. No significant interaction of the genotype with training for body mass and body composition variables was observed. Although, there were three significant genotype x training interactions for maximal oxygen uptake variables, regardless of body mass i.e.: for VO2max (p < 0.05), HRmax (p < 0.0001) and HRAT/HRmax (p < 0.0001). Significantly greater improvement in VO2max was gained by the CC+AC group compared to the AA genotype group. The present results support the hypothesis that individual differences in trainability are at least in part determined by the genetic component and MTHFR A1298C seems to be one of the many polymorphisms involved. PMID:28031756

  18. MTHFR C677T polymorphism and recurrent early pregnancy loss risk in north Indian population.

    PubMed

    Nair, Rohini R; Khanna, Anuradha; Singh, Kiran

    2012-02-01

    Recurrent early pregnancy loss (REPL) is a multifactorial disorder as both genetic and environmental factors contribute to the development of disease. Folate metabolism is an important mechanism to ensure proper fetal growth. Hyperhomocysteinemia leads to a number of disorders and REPL is one of them. In a case-control study DNA from 106 cases with the history of 3 or more REPL and 140 healthy fertile controls with successful pregnancy outcomes were genotyped for C677T single-nucleotide polymorphism (SNP) of the MTHFR (methylenetetrahydrofolate reductase) gene through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), which was further confirmed by sequencing. Allele frequencies of REPL cases were compared with healthy controls and a statistically significant association was found between REPL and the mutant T allele (χ² = 8.786, odds ratio [OR] = 2.20, 95% confidence interval [CI] = 1.323-3.9658, P = .003). The genotype frequencies of SNP C677T also differ significantly between these 2 groups (χ² = 8.237, P = .016). The OR for heterozygous CT in the REPL versus controls is 1.9591 (95% CI = 1.0285-3.7318, P = .04). The OR for TT homozygous is 6.3009 (95% CI = 1.2065, P = .02). Combined odds ratio of CT and TT against the control has been calculated as 2.2194 (95% CI = 1.2029-4.0952, P = .02) which is also significant. Thus the present study clearly indicates that homozygosity and heterozygosity for the MTHFR C677T polymorphism confer a 6.3009- and 1.9591-fold increased risk of idiopathic REPL, respectively.

  19. Effects of Common Polymorphisms in the MTHFR and ACE Genes on Diabetic Peripheral Neuropathy Progression: a Meta-Analysis.

    PubMed

    Wu, Shuai; Han, Yan; Hu, Qiang; Zhang, Xiaojie; Cui, Guangcheng; Li, Zezhi; Guan, Yangtai

    2017-05-01

    Diabetic peripheral neuropathy (DPN) is a microvascular complication of diabetes mellitus. The aim of this meta-analysis was to evaluate the effects of methylenetetrahydrofolate reductase (MTHFR) 677 C>T and ACE I/D polymorphisms in the development of DPN. We systematically reviewed published studies on MTHFR 677 C>T and ACE I/D polymorphisms and DPN found in various types of electronic databases. Strengthening the Reporting of Observational studies in Epidemiology (STROBE) quality score systems were used to determine the quality of the articles selected for inclusion. Odds ratios (ORs) and its corresponding 95 % confidence interval (95 % CI) were calculated. We used STATA statistical software (version 12.0, Stata Corporation, College Station, TX, USA) to deal with statistical data. Our results indicated an association of ACE D>I mutation (OR = 1.43, 95 % CI 1.12-1.83, P = 0.004) and MTHFR 677 C>T mutation (OR = 1.43, 95 % CI 1.08-1.90, P = 0.014) with DPN under the allele model, and similar results were also found under the dominant model (all P < 0.05). Subgroup analysis by country indicated that the MTHFR 677 C>T polymorphism may be the main risk factor for DPN in Turkey under four genetic models. ACE D>I mutation was correlated with DPN in Japanese and Pakistani populations in the majority of groups. The relationships of MTHFR 677 C>T and ACE I/D polymorphisms with DPN patients presented in this meta-analyses support the view that the MTHFR and ACE genes might play an important role in the development of DPN.

  20. Association of OGG1 and MTHFR polymorphisms with age-related cataract: A systematic review and meta-analysis

    PubMed Central

    Liu, Yizhi

    2017-01-01

    Purpose To discern and confirm genetic biomarkers that help identify populations at high risk for age-related cataract (ARC). Methods A literature search was performed in the PubMed, Web of Science and China National Knowledge Internet databases for genetic association studies published before June 26, 2016 regarding ARC susceptibility. All genetic polymorphisms reported were systematically reviewed, followed by extraction of candidate genes/loci with sufficient genotype data in ≥3 studies for the meta-analysis. A random/fixed-effects model was used to calculate the pooled odds ratios and 95% confidence intervals to evaluate the associations considering multiple genetic models. Sensitivity analysis was also performed. Results A total of 144 polymorphisms in 36 genes were reported in the 61 previous genetic association studies. Thereby, three polymorphisms of two genes (8-oxoguanine DNA glycosylase-1 [OGG1]; methylenetetrahydrofolate reductase NADPH [MTHFR]) in eight studies were included in the meta-analysis. Regarding the OGG1-rs1052133, the GG (OR = 1.925; 95%CI, 1.181–3.136; p = 0.009) and CG (OR = 1.384; 95%CI, 1.171–1.636; p<0.001) genotypes indicated higher risk of ARC. For the MTHFR gene, the CC+TT genotype of rs1801133 might be protective (OR, 0.838; 95%CI, 0.710–0.989; p = 0.036), whereas the AA+CC genotype of rs1801131 indicated increased risk for the mixed subtype (OR = 1.517; 95%CI, 1.113–2.067; p = 0.008). Conclusions Polymorphisms of OGG1 and MTHFR genes are associated with ARC susceptibility and may help identify populations at high risk for ARC. PMID:28253266

  1. The MTR A2756G polymorphism is associated with an increase of plasma homocysteine concentration in Brazilian individuals with Down syndrome.

    PubMed

    Biselli, J M; Goloni-Bertollo, E M; Haddad, R; Eberlin, M N; Pavarino-Bertelli, E C

    2008-01-01

    Individuals with Down syndrome (DS) present decreased homocysteine (Hcy) concentration, reflecting a functional folate deficiency secondary to overexpression of the cystathionine ss-synthase gene. Since plasma Hcy may be influenced by genetic polymorphisms, we evaluated the influence of C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase gene (MTHFR), of A2756G polymorphism in the methionine synthase gene (MTR), and of A80G polymorphism in the reduced folate carrier 1 gene on Hcy concentrations in Brazilian DS patients. Fifty-six individuals with free trisomy 21 were included in the study. Plasma Hcy concentrations were measured by liquid chromatography_tandem mass spectrometry with linear regression coefficient r(2) = 0.9996, average recovery between 92.3 to 108.3% and quantification limits of 1.0 micromol/L. Hcy concentrations >15 micromol/L were considered to characterize hyperhomocystinemia. Genotyping for the polymorphisms was carried out by polymerase chain reaction followed by enzyme digestion and allele-specific polymerase chain reaction. The mean Hcy concentration was 5.2 +/- 3.3 micromol/L. There was no correlation between Hcy concentrations and age, gender or MTHFR C677T, A1298C and reduced folate carrier 1 A80G genotype. However, Hcy concentrations were significantly increased in the MTR 2756AG heterozygous genotype compared to the MTR 2756AA wild-type genotype. The present results suggest that the heterozygous genotype MTR 2756AG is associated with the increase in plasma Hcy concentrations in this group of Brazilian patients with DS.

  2. Folate Levels and Polymorphisms in the Genes MTHFR, MTR, and TS in Colorectal Cancer

    PubMed Central

    Taflin, Helena; Wettergren, Yvonne; Odin, Elisabeth; Carlsson, Göran; Derwinger, Kristoffer

    2014-01-01

    AIM The aim of the study was to explore and describe the effect of polymorphisms in folate-associated genes regarding the levels of different folate forms and their distribution in tumors and mucosa in patients with colorectal cancer. MATERIALS AND METHODS Tumor and mucosa tissues from 53 patients with colorectal cancer were analyzed. The concentrations of tetrahydrofolate (THF), 5-methylTHF, and 5,10-methyleneTHF were measured by liquid chromatography—mass spectrometry. Genotyping of polymorphisms in the folate-associated genes methylenetetrahydrofolate reductase (MTHFR, C677T), methionine synthase (MTR, A2756G), and thymidylate synthase (TS, 5′-TSER 28 bp tandem repeat and 3′-TSUTR 6 bp deletion/insertion), were done by real-time polymerase chain reaction. Folate levels and distributions were determined in the total patient cohort and after subgrouping by genotypes. RESULTS The total folate level, as well as the THF and 5,10-methyleneTHF levels, were significantly higher in the tumor compared with mucosa tissue (P = 0.030, 0.031, and 0.015, respectively). The individual variation in folate levels in both tumor and mucosa were larger than the variation found when the patients were subgrouped by the gene polymorphisms. No significant differences in the mean concentration of any folate in the mucosa or tumor tissue were found in relation to the analyzed polymorphisms. The percentage level of 5,10-methyleneTHF in tumors was highest in patients with the MTHFR 677 CC genotype, and lowest in patients with the TT genotype (P = 0.033). A significantly lower percentage level of the 5,10-methyleneTHF level was found in tumors of patients with the 5′-TSER 3R/3R genotype (P = 0.0031). CONCLUSION A significant difference was found between the percentage level of 5,10-methyleneTHF in tumor tissues in relation to the MTHFR C677T and 5′-TSER 28 bp repeat polymorphisms. However, no differences were found in the actual tissue folate levels, or in their distribution, in

  3. Gene polymorphisms involved in folate and methionine metabolism and increased risk of sporadic colorectal adenocarcinoma.

    PubMed

    Guimarães, José Luiz Miranda; Ayrizono, Maria de Lurdes; Coy, Cláudio Saddy Rodrigues; Lima, Carmen Silvia Passos

    2011-10-01

    This pilot study has compared the polymorphic genotype frequencies of methylenetetrahydrofolate reductase (MTHFR A1298C and C677T), methionine synthase (MTR A2756G), methionine synthase reductase (MTRR A66G), and thymidylate synthase (TS 2R/3R) in 113 patients with sporadic colorectal adenocarcinoma (SCA) and 188 healthy blood donors, used as matched controls. The aim was to assess the role of these genotypes in the increased risk of SCA among the southeastern Brazilian population. Carriers of genotype MTRR 66GG, or the combined variants MTHFR 1298AC + CC plus 677CT + TT, or MTHFR 677CT + TT plus MTR 2756AG + GG, or MTHFR 1298AC + CC plus 677CT + TT plus MTR 2756AG + GG, or yet, MTHFR 1298AC + CC plus 677CT + TT plus MTRR 66AG + GG, respectively, showed an increased risk of the order of 1.99-, 3.26-, 2.22-, 10.92-, and 14.88-fold of developing SCA when compared with carriers of the other studied polymorphic genotypes, whether in isolation or in combination. In addition, individuals with the MTHFR 677CT + TT or the MTR 2756AG + GG genotypes had a 2.12- and a 1.42-fold increased risks of SCA onset before 50 years of age. African-Brazilians with the MTRR 66GG genotype had a 1.98-fold increased risk of SCA while individuals with the MTR 2756AG + GG and the MTHFR 677CT + TT genotypes showed a 2.11- and a 1.62-fold increased risk of undifferentiated and advanced tumors at diagnosis, respectively. Carriers of genotype MTHFR 1298AC + CC or MTHFR 1298AC + CC plus MTRR 66AG + GG had a 1.42- and a 3.07-fold increased risk of rectal tumor, respectively. Additionally, carriers of MTHFR 677CT + TT or MTHFR 677CT + TT plus TS 2R/3R + 3R/3R had a 1.55- and a 5.39-fold increased risk for colon tumor, respectively, in comparison with carriers of the wild genotypes. These data suggest that all polymorphisms coding for folate and methionine-dependent enzymes, particularly when present in combination with

  4. Effects of folic acid deficiency and MTHFRC677T polymorphisms on cytotoxicity in human peripheral blood lymphocytes

    SciTech Connect

    Wu Xiayu; Liang Ziqing; Zou Tianning; Wang Xu

    2009-02-13

    Apoptosis (APO) and necrosis (NEC) are two different types of cell death occurring in response to cellular stress factors. Cells with DNA damage may undergo APO or NEC. Folate is an essential micronutrient associated with DNA synthesis, repair and methylation. Methylenetetrahydrofolate reductase (MTHFR) regulates intracellular folate metabolism. Folate deficiency and MTHFR C677T polymorphisms have been shown to be related to DNA damage. To verify the cytotoxic effects of folate deficiency on cells with different MTHFR C677T genotypes, 15 human peripheral lymphocyte cases with different MTHFR C677T genotypes were cultured in folic acid (FA)-deficient and -sufficient media for 9 days. Cytotoxicity was quantified using the frequencies of APO and NEC as endpoints, the nuclear division index (NDI), and the number of viable cells (NVC). These results showed that FA is an important factor in reducing cytotoxicity and increasing cell proliferation. Lymphocytes with the TT genotype proliferated easily under stress and exhibited different responses to FA deficiency than lymphocytes with the CC and CT genotypes. A TT individual may accumulate more cytotoxicity under cytotoxic stress, suggesting that the effects of FA deficiency on cytotoxicity are greater than the effects in individuals with the other MTHFR C677T variants.

  5. Gene polymorphisms as risk factors for predicting the cardiovascular manifestations in Marfan syndrome. Role of folic acid metabolism enzyme gene polymorphisms in Marfan syndrome.

    PubMed

    Benke, Kálmán; Ágg, Bence; Mátyás, Gábor; Szokolai, Viola; Harsányi, Gergely; Szilveszter, Bálint; Odler, Balázs; Pólos, Miklós; Maurovich-Horvat, Pál; Radovits, Tamás; Merkely, Béla; Nagy, Zsolt B; Szabolcs, Zoltán

    2015-10-01

    Folic acid metabolism enzyme polymorphisms are believed to be responsible for the elevation of homocysteine (HCY) concentration in the blood plasma, correlating with the pathogenesis of aortic aneurysms and aortic dissection. We studied 71 Marfan patients divided into groups based on the severity of cardiovascular involvement: no intervention required (n=27, Group A); mild involvement requiring intervention (n=17, Group B); severe involvement (n=27, Group C) subdivided into aortic dilatation (n=14, Group C1) and aortic dissection (n=13, Group C2), as well as 117 control subjects. We evaluated HCY, folate, vitamin B12 and the polymorphisms of methylenetetrahydrofolate reductase (MTHFR;c.665C>T and c.1286A>C), methionine synthase (MTR;c.2756A>G) and methionine synthase reductase (MTRR;c.66A>G). Multiple comparisons showed significantly higher levels of HCY in Group C2 compared to Groups A, B, C1 and control group (p<0.0001, p<0.0001, p=0.001 and p=0.003, respectively). Folate was lower in Group C2 than in Groups A, B, C1 and control subjects (p<0.0001, p=0.02, p<0.0001 and p<0.0001, respectively). Group C2 had the highest prevalence of homozygotes for all four gene polymorphisms. Multivariate logistic regression analysis revealed that HCY plasma level was an independent risk factor for severe cardiovascular involvement (Group C; odds ratio [OR] 1.85, 95% confidence interval [CI] 1.28-2.67, p=0.001) as well as for aortic dissection (Group C2; OR 2.49, 95%CI 1.30-4.78, p=0.006). In conclusion, severe cardiovascular involvement in Marfan patients, and especially aortic dissection, is associated with higher HCY plasma levels and prevalence of homozygous genotypes of folic acid metabolism enzymes than mild or no cardiovascular involvement. These results suggest that impaired folic acid metabolism has an important role in the development and remodelling of the extracellular matrix of the aorta.

  6. MTHFR, MTR, and MTRR Polymorphisms in Relation to p16INK4A Hypermethylation in Mucosa of Patients with Colorectal Cancer

    PubMed Central

    Wettergren, Yvonne; Odin, Elisabeth; Carlsson, Göran; Gustavsson, Bengt

    2010-01-01

    We recently analyzed the hypermethylation status of the p16INK4a (p16) gene promoter in normal-appearing mucosa obtained from patients with colorectal cancer. Hypermethylation of p16 was associated with reduced survival of these patients. In the present study, germ line polymorphisms in the folate- and methyl-associated genes, methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR) and methionine synthase reductase (MTRR), were analyzed in the same patient cohort to find a possible link between these genetic variants and p16 hypermethylation. Genomic DNA was extracted from blood of patients (n = 181) and controls (n = 300). Genotype analyses were run on an ABI PRISM® 7900HT sequence-detection system (Applied Biosystems), using real-time polymerase chain reaction and TaqMan chemistry. The results showed that the genotype distributions of the patient and control groups were similar. No significant differences in cancer-specific or disease-free survival of stage I–III patients according to polymorphic variants were detected, nor were any differences in cancer-specific or disease-free survival detected when patients were subgrouped according to the MTHFR or MTR genotype groups and dichotomized by p16 hypermethylation status in mucosa. However, patients with the MTRR 66 AA/AG genotypes were found to have a significantly worse cancer-specific survival when the mucosa were positive, compared with negative, for p16 hypermethylation (hazard ratio 2.7; 95% confidence interval 1.2–6.4; P = 0.023). In contrast, there was no difference in survival among patients with the MTRR 66 GG genotype stratified by p16 hypermethylation status. These results indicate a relationship between genetic germ-line variants of the MTRR gene and p16 hypermethylation in mucosa, which may affect the clinical outcome of patients with colorectal cancer. PMID:20549016

  7. Polymorphisms in the MTHFR gene are associated with recurrence risk in lymph node-positive breast cancer patients

    PubMed Central

    Suner, Ali; Buyukhatipoglu, Hakan; Aktas, Gokmen; Kus, Tulay; Ulasli, Mustafa; Oztuzcu, Serdar; Kalender, Mehmet Emin; Sevinc, Alper; Kul, Seval; Camci, Celaletdin

    2016-01-01

    Purpose The aim of this study is to clarify the relationship between recurrence risk of breast cancer and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms. Patients and methods Breast cancer patients who had undergone surgery in Gaziantep University Oncology Hospital between June 2005 and June 2012 were followed-up and retrospectively enrolled in this study. Blood samples were collected from all patients to assess MTHFR C677T polymorphisms. Stage according to tumor–node–metastasis system, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 status, grade of disease, menopausal status, and administered chemotherapy or hormonal therapy were recorded. Effects of these parameters on recurrence risk were evaluated using univariate analysis and multivariate binary logistic regression model. Results Association of MTHFR C677T polymorphisms with recurrence risk was evaluated in 298 patients whose median age was 47 years (range: 21–79 years). In all patients, age (odds ratio [OR] =0.953, P=0.005) and N3 lymph node status (OR =6.293, P=0.001) were found to affect the recurrence risk. While MTHFR homozygote genotype did not have an effect on recurrence risk in all patients, increased risk was observed in lymph node-positive subgroup (OR =4.271; 95% CI 1.515–12.023; P=0.006). Adjusting for age, tumor size (T), and node status (N), MTHFR homozygote genotype had more statistically significant risk for recurrence (OR =3.255; 95% CI 1.047–10.125; P=0.041). Conclusion MTHFR TT genotype was found to be associated with increased recurrence risk in patients with lymph node-positive breast cancer. PMID:27672331

  8. Association between C677T and A1298C polymorphisms of the MTHFR gene and risk of male infertility: a meta-analysis.

    PubMed

    Yang, Y; Luo, Y Y; Wu, S; Tang, Y D; Rao, X D; Xiong, L; Tan, M; Deng, M Z; Liu, H

    2016-04-26

    Published studies on the association between the C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene and male infertility risk are controversial. To obtain a more precise evaluation, we performed a meta-analysis based on published case-control studies. We conducted an electronic search of PubMed, EMBASE, the Cochrane Library, the Web of Science, and the China Knowledge Resource Integrated Database for papers on MTHFR gene C677T and A1298C polymorphisms and male infertility risk. Pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were used to assess the strength of association in homozygote, heterozygote, dominant, recessive, and additive models. Statistical heterogeneity, test of publication bias, and sensitivity analysis were carried out using the STATA software (Version 13.0). Overall, 21 studies of C677T (4505 cases and 4024 controls) and 13 studies of A1298C (2785 cases and 3094 controls) were included in this meta-analysis. For C677T, the homozygote comparison results were OR = 1.629, 95%CI (1.215- 2.184), and the recessive model results were OR = 1.462 (1.155- 1.850). For A1298C, the homozygote comparison results were OR = 1.289 (1.029-1.616), and the recessive model results were OR = 1.288 (1.034-1.604). In conclusion, the current meta-analysis showed that the MTHFR C677T polymorphism was associated with a significantly increased male infertility risk in the Asian and overall populations, but not in the Caucasian population, and there was a significant association between the A1298C polymorphism and male infertility risk in the Asian, Caucasian, and overall groups.

  9. Geographical Distribution of MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in China: Findings from 15357 Adults of Han Nationality

    PubMed Central

    Yang, Boyi; Liu, Yuyan; Li, Yongfang; Fan, Shujun; Zhi, Xueyuan; Lu, Xiangxiang; Wang, Da; Zheng, Quanmei; Wang, Yinuo; Wang, Yanxun; Sun, Guifan

    2013-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C and methionine synthase reductase (MTRR) A66G polymorphisms are important genetic determinants for homocysteine (Hcy) levels, and are associated with several disorders. These polymorphisms are heterogeneously distributed worldwide. Our objective was to explore the geographical distributions of these polymorphisms in China. Methodologies 15357 healthy adults were recruited from 10 regions. Buccal samples were collected and genomic DNA was isolated. Genotyping was performed using the fluorogenic 5′-nuclease assay. Principal Findings The prevalence of the three polymorphisms among different populations from China varied significantly and showed apparent geographical gradients. For MTHFR C677T, the frequencies of the 677T allele and the 677TT genotype were significantly higher among northern populations and ranged from the lowest values (24.0% and 6.4%, respectively) in Hainan (southern) to the highest values (63.1% and 40.8%, respectively) in Shandong (northern). For MTHFR A1298C, the 1298C allele and the 1298CC genotype frequencies were significantly higher among southern populations and increased from low values (13.1% and 1.4%, respectively) in Shandong to high values (25.7% and 6.7%, respectively) in Hainan. For A66G, the 66G allele and the 66GG genotype frequencies increased from lower values (23.7% and 5.4%, respectively) in Shandong to higher values (29.2% and 8.6%, respectively) in Hainan. The overall frequency of the 677T allele, 677TT genotype, 1298C allele, 1298CC genotype, 66G allele and 66GG genotype in the Chinese Han population was 45.2%, 23.2%, 18.6%, 3.9%, 25.7%, and 6.6%, respectively. No gender differences were found in the prevalence of both the MTHFR C677T and MTRR A66G polymorphisms. Conclusions This study indicates that there are marked geographical variations in the prevalence of the three polymorphisms among Chinese Han populations. Our baseline data may be useful for

  10. Three genetic polymorphisms of homocysteine-metabolizing enzymes and risk of coronary heart disease: a meta-analysis based on 23 case-control studies.

    PubMed

    Chen, Ling; Liu, Liu; Hong, Kui; Hu, Jianxin; Cheng, Xiaoshu

    2012-02-01

    Many epidemiological studies have explored the relationships between three genetic polymorphisms of genes encoding homocysteine-metabolizing enzymes (methionine synthase [MTR] A2756G, methionine synthase reductase [MTRR] A66G, and N(5),N(10)-methylenetetrahydrofolate reductase [MTHFR] A1298C) and risk of coronary heart disease (CHD), but no conclusive results were obtained. Therefore, we performed a meta-analysis of 23 case-control studies. Odds ratio (OR) and 95% confidence interval (95% CI) were used to examine the strength of the associations. Among those primary studies, 22 studies were for Europeans, and one study focused on the MTR A2756G polymorphism in Asians. The results of combined analyses of the MTR A2756G polymorphism suggested that the G allele was associated with increased risk of CHD and myocardial infarction (MI) especially for Europeans (GG vs. AA for CHD: OR [95% CI]=1.63 [1.18-2.25], p(z)(-test)=0.001, p(heterogeneity)=0.274; GG+AG vs. AA for MI: OR [95% CI]=1.44 [1.08-1.93], p(z)(-test)=0.014, p(heterogeneity)=0.611). In addition, the G allele was also associated with higher risk CHD based on population-based case-control studies (PCC) (GG vs. AA: OR [95% CI]=1.75 [1.24-2.49], p(z)(-test)=0.002, p(heterogeneity)=0.316). The results suggested that the MTRR A66G polymorphism was not associated with risk of CHD for Europeans (AA vs. GG: OR [95% CI]=1.07 [0.59-1.94], p(z)(-test)=0.831, p(heterogeneity)<0.01). The results suggested that the C allele of the MTHFR A1298C polymorphism might be associated with the increased risk of MI for Europeans (CC vs. CA+AA: OR [95% CI]=1.37 [1.03-1.84], p(z)(-test)=0.033, p(heterogeneity)=0.668). However, when subgroup analyses for sources of controls were performed, conflicting results were obtained. The results suggested that the C allele was associated with decreased risk of CHD based on hospital-based case-control studies, but associated with increased risk of CHD based on PCC. This meta-analysis suggests that

  11. Regional Brain Shrinkage over Two Years: Individual Differences and Effects of Pro-Inflammatory Genetic Polymorphisms

    PubMed Central

    Persson, N.; Ghisletta, P.; Dahle, C.L.; Bender, A.R.; Yang, Y.; Yuan, P.; Daugherty, A.M.; Raz, N.

    2014-01-01

    We examined regional changes in brain volume in healthy adults (N = 167, age 19-79 years at baseline; N = 90 at follow-up) over approximately two years. With latent change score models, we evaluated mean change and individual differences in rates of change in 10 anatomically-defined and manually-traced regions of interest (ROIs): lateral prefrontal cortex (LPFC), orbital frontal cortex (OF), prefrontal white matter (PFw), hippocampus (HC), parahippocampal gyrus (PhG), caudate nucleus (Cd), putamen (Pt), insula (In), cerebellar hemispheres (CbH), and primary visual cortex (VC). Significant mean shrinkage was observed in the HC, CbH, In, OF, and the PhG, and individual differences in change were noted in all regions, except the OF. Pro-inflammatory genetic variants mediated shrinkage in PhG and CbH. Carriers of two T alleles of interleukin-1β (IL-1βC-511T, rs16944) and a T allele of methylenetetrahydrofolate reductase (MTHFRC677T, rs1801133) polymorphisms showed increased PhG shrinkage. No effects of a pro-inflammatory polymorphism for C-reactive protein (CRP-286C>A>T, rs3091244) or apolipoprotein (APOE) ε4 allele were noted. These results replicate the pattern of brain shrinkage observed in previous studies, with a notable exception of the LPFC thus casting doubt on the unique importance of prefrontal cortex in aging. Larger baseline volumes of CbH and In were associated with increased shrinkage, in conflict with the brain reserve hypothesis. Contrary to previous reports, we observed no significant linear effects of age and hypertension on regional brain shrinkage. Our findings warrant further investigation of the effects of neuroinflammation on structural brain change throughout the lifespan. PMID:25264227

  12. Regional brain shrinkage over two years: individual differences and effects of pro-inflammatory genetic polymorphisms.

    PubMed

    Persson, N; Ghisletta, P; Dahle, C L; Bender, A R; Yang, Y; Yuan, P; Daugherty, A M; Raz, N

    2014-12-01

    We examined regional changes in brain volume in healthy adults (N=167, age 19-79years at baseline; N=90 at follow-up) over approximately two years. With latent change score models, we evaluated mean change and individual differences in rates of change in 10 anatomically-defined and manually-traced regions of interest (ROIs): lateral prefrontal cortex (LPFC), orbital frontal cortex (OF), prefrontal white matter (PFw), hippocampus (Hc), parahippocampal gyrus (PhG), caudate nucleus (Cd), putamen (Pt), insula (In), cerebellar hemispheres (CbH), and primary visual cortex (VC). Significant mean shrinkage was observed in the Hc, CbH, In, OF, and PhG, and individual differences in change were noted in all regions, except the OF. Pro-inflammatory genetic variants modified shrinkage in PhG and CbH. Carriers of two T alleles of interleukin-1β (IL-1β C-511T, rs16944) and a T allele of methylenetetrahydrofolate reductase (MTHFR C677T, rs1801133) polymorphisms showed increased PhG shrinkage. No effects of a pro-inflammatory polymorphism for C-reactive protein (CRP-286C>A>T, rs3091244) or apolipoprotein (APOE) ε4 allele were noted. These results replicate the pattern of brain shrinkage observed in previous studies, with a notable exception of the LPFC, thus casting doubt on the unique importance of prefrontal cortex in aging. Larger baseline volumes of CbH and In were associated with increased shrinkage, in conflict with the brain reserve hypothesis. Contrary to previous reports, we observed no significant linear effects of age and hypertension on regional brain shrinkage. Our findings warrant further investigation of the effects of neuroinflammation on structural brain change throughout the lifespan.

  13. Meta-Prediction of MTHFR Gene Polymorphism Mutations and Associated Risk for Colorectal Cancer

    PubMed Central

    Yu, C. H.

    2016-01-01

    The methylenetetrahydrofolate reductase (MTHFR) gene is one of the most investigated of the genes associated with chronic human diseases because of its associations with hyperhomocysteinemia and toxicity. It has been proposed as a prototype gene for the prevention of colorectal cancer (CRC). The major objectives of this meta-analysis were to examine the polymorphism-mutation patterns of MTHFR and their associations with risk for CRC as well as potential contributing factors for mutations and disease risks. This analysis included 33,626 CRC cases and 48,688 controls across 92 studies for MTHFR 677 and 16,367 cases and 24,874 controls across 54 studies for MTHFR 1298, comprising data for various racial and ethnic groups, both genders, and multiple cancer sites. MTHFR 677 homozygous TT genotype was protective (p < .05) for CRC for all included populations; however, with heterogeneity across various racial–ethnic groups and opposing findings, it was a risk genotype for the subgroup of Hispanics (p < .01). Additional countries for which subgroup analyses resulted in 677 TT as a risk genotype included Turkey, Romania, Croatia, Hungary, Portugal, Mexico, Brazil, U.S. Hawai’i, Taiwan, India, and Egypt. Countries with the highest mutation rates and risks for both MTHFR 677 and 1298 genotypes are presented using global maps to visualize the grouping patterns. Meta-predictive analyses revealed that air pollution levels were associated with gene polymorphisms for both genotypes. Future nursing research should be conducted to develop proactive measures to protect populations in cities where air pollution causes more deaths. PMID:26858257

  14. Association of Thymidylate Synthase Gene Polymorphisms with Stavudine Triphosphate Intracellular Levels and Lipodystrophy▿

    PubMed Central

    Domingo, Pere; Cabeza, M. Carmen; Pruvost, Alain; Torres, Ferran; Salazar, Juliana; del Mar Gutierrez, M.; Mateo, M. Gracia; Fontanet, Angels; Fernandez, Irene; Domingo, Joan C.; Villarroya, Francesc; Vidal, Francesc; Baiget, Montserrat

    2011-01-01

    The antiviral activity and toxicity of stavudine (d4T) depend on its triphosphate metabolite, stavudine triphosphate (d4T-TP). Therefore, modifications in intracellular levels of d4T-TP may change the toxicity profile of stavudine. d4T-TP intracellular levels in peripheral blood mononuclear cells were determined with a prominence liquid chromatograph connected to a triple-quadruple mass spectrometer. Polymorphisms in the thymidylate synthase (TS), methylenetetrahydrofolate reductase (MTHFR), dihydrofolate reductase (DHFR), reduced folate carrier 1 (RFC1; SLC19A1), and cyclin D1 (CCND1) genes were determined by direct sequencing using an ABI Prism 3100 genetic analyzer or Fluidigm's Biomark system. The Mann-Whitney test, rank analysis of variance (with Bonferroni's adjusted post hoc comparisons), and logistic regression were used for the inferential analyses. Thirty-three stavudine-treated patients were enrolled in this cross-sectional study. d4T-TP intracellular levels were 11.50 fmol/106 cells (interquartile range [IQR] = 8.12 to 13.87 fmol/106 cells) in patients with a high-expression TS genotype (2/3G, 3C/3G, and 3G/3G), whereas in those with a low-expression TS genotype (2/2, 2/3C, and 3C/3C), they were 21.40 fmol/106 cells (IQR = 18.90 to 27.0 fmol/106 cells) (P < 0.0001). Polymorphisms in the MTHFR, DHFR, RFC1, and CCND1 genes did not influence the intracellular concentration of d4T-TP. d4T-TP levels were independently associated with the TS genotype (low versus high expression; odds ratio [OR] = 86.22; 95% confidence interval [CI] = 8.48 to nonestimable; P = 0.0023). The low-expression TS genotype was associated with the development of HIV/highly active antiretroviral therapy-associated lypodystrophy syndrome (HALS) (OR = 14.0; 95% CI = 2.09 to 108.0; P = 0.0032). Our preliminary data show that polymorphisms in the thymidylate synthase gene are strongly associated with d4T-TP intracellular levels and with development of HALS. PMID:21282454

  15. A novel lateral flow assay based on GoldMag nanoparticles and its clinical applications for genotyping of MTHFR C677T polymorphisms

    NASA Astrophysics Data System (ADS)

    Hui, Wenli; Zhang, Sinong; Zhang, Chao; Wan, Yinsheng; Zhu, Juanli; Zhao, Gang; Wu, Songdi; Xi, Dujuan; Zhang, Qinlu; Li, Ningning; Cui, Yali

    2016-02-01

    Current techniques for single nucleotide polymorphism (SNP) detection require tedious experimental procedures and expensive and sophisticated instruments. In this study, a visual genotyping method has been successfully established via combining ARMS-PCR with gold magnetic nanoparticle (GoldMag)-based lateral flow assay (LFA) and applied to the genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T. C677T substitution of the gene MTHFR leads to an increased risk of diseases. The genotyping result is easily achievable by visual observation within 5 minutes after loading of the PCR products onto the LFA device. The system is able to accurately assess a broad detection range of initial starting genomic DNA amounts from 5 ng to 1200 ng per test sample. The limit of detection reaches 5 ng. Furthermore, our PCR-LFA system was applied to clinical trials for screening 1721 individuals for the C677T genotypes. The concordance rate of the genotyping results detected by PCR-LFA was up to 99.6% when compared with the sequencing results. Collectively, our PCR-LFA has been proven to be rapid, accurate, sensitive, and inexpensive. This new method is highly applicable for C677T SNP screening in laboratories and clinical practices. More promisingly, it could also be extended to the detection of SNPs of other genes.

  16. Prevalence of hyperhomocysteinemia and the MTHFR C677T polymorphism in patients with arterial and venous thrombosis from North Western Russia.

    PubMed

    Shmeleva, Veronika M; Kapustin, Sergey I; Papayan, Ludmila P; Sobczyńska-Malefora, Agata; Harrington, Dominic J; Savidge, Geoffrey F

    2003-01-01

    Conflicting data from Western European and USA population studies led us to investigate hyperhomocysteinemia (HHcy), the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms and thrombotic disease in North Western Russia. Plasma total homocysteine (tHcy) levels, MTHFR C677T genotype, selected life style determinants and haemostatic factor activity were determined in patients with arterial (n = 33), venous (n = 40), arterial + venous (n = 11) thrombosis and healthy controls (n = 30). We found raised median tHcy levels in all patient groups vs. controls (p < 0.05), with odds ratios (95% CI) for vascular disease among patients with HHcy (defined as > 15 micromol/l) of 3.9 (0.6 - 14.3), 4.8 (1.2 - 18.8) and 15.8 (2.8 - 87.3) respectively. tHcy levels were a function of MTHFR C677T genotype, and all patients with tHcy levels > 30 micromol/l had the MTHFR C677T homozygous substitution. Elevated tHcy levels (p < 0.05) were identified in smokers and coffee drinkers, with the degree of elevation dependent on MTHFR C677T genotype. Of the studied haemostatic parameters increased factor VIII activity and vWF antigen and activity was observed in HHcy subjects. We conclude that HHcy and MTHFR C677T genotype are positively associated with arterial and venous thrombotic disease in the population of North Western Russia.

  17. Breast cancer risk associated with gene expression and genotype polymorphisms of the folate-metabolizing MTHFR gene: a case-control study in a high altitude Ecuadorian mestizo population.

    PubMed

    López-Cortés, Andrés; Echeverría, Carolina; Oña-Cisneros, Fabián; Sánchez, María Eugenia; Herrera, Camilo; Cabrera-Andrade, Alejandro; Rosales, Felipe; Ortiz, Malena; Paz-Y-Miño, César

    2015-08-01

    Breast cancer (BC) is the leading cause of cancer-related death among women in 2014. Methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), and MTR reductase (MTRR) are enzymes that play an important role in folate metabolism. The single nucleotide polymorphisms, MTHFR C677T, A1298C, MTR A2756G, and MTRR A66G, alter plasmatic folate and homocysteine concentrations, causing problems during the repairment, synthesis, and methylation of the genetic material. Therefore, it is essential to know how BC risk is associated with histopathological and immunohistochemical characteristics, genotype polymorphisms, and gene expression in a high altitude Ecuadorian mestizo population. DNA was extracted from 195 healthy and 114 affected women. Genotypes were determined by restriction enzymes and genomic sequencing. mRNA was extracted from 26 glandular breast tissue samples, both from cancerous tissue and healthy tissue adjacent to the tumor. Relative gene expression was determined with the comparative Livak method (2(-ΔΔCT)). We found significant association between the rs1801133 (A222V) genotypes and an increased risk of BC development: C/T (odds ratio [OR] = 1.8; 95 % confidence interval [CI] = 1.1-3.2; P = 0.039), T/T (OR = 2.9; 95 % CI = 1.2-7.2; P = 0.025), and C/T + T/T (OR = 1.9; 95 % CI = 1.1-3.3; P = 0.019). Regarding relative gene expression, we found significant mRNA subexpression between the combined genotypes C/T + T/T (rs1801133) and triple negative breast cancer (TNBC) (P = 0.034). In brief, the MTHFR gene and its protein could act as potential predictive biomarkers of BC, especially TNBC among the high altitude Ecuadorian mestizo population.

  18. High-dose folic acid supplementation alters the human sperm methylome and is influenced by the MTHFR C677T polymorphism

    PubMed Central

    Aarabi, Mahmoud; San Gabriel, Maria C.; Chan, Donovan; Behan, Nathalie A.; Caron, Maxime; Pastinen, Tomi; Bourque, Guillaume; MacFarlane, Amanda J.; Zini, Armand; Trasler, Jacquetta

    2015-01-01

    Dietary folate is a major source of methyl groups required for DNA methylation, an epigenetic modification that is actively maintained and remodeled during spermatogenesis. While high-dose folic acid supplementation (up to 10 times the daily recommended dose) has been shown to improve sperm parameters in infertile men, the effects of supplementation on the sperm epigenome are unknown. To assess the impact of 6 months of high-dose folic acid supplementation on the sperm epigenome, we studied 30 men with idiopathic infertility. Blood folate concentrations increased significantly after supplementation with no significant improvements in sperm parameters. Methylation levels of the differentially methylated regions of several imprinted loci (H19, DLK1/GTL2, MEST, SNRPN, PLAGL1, KCNQ1OT1) were normal both before and after supplementation. Reduced representation bisulfite sequencing (RRBS) revealed a significant global loss of methylation across different regions of the sperm genome. The most marked loss of DNA methylation was found in sperm from patients homozygous for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, a common polymorphism in a key enzyme required for folate metabolism. RRBS analysis also showed that most of the differentially methylated tiles were located in DNA repeats, low CpG-density and intergenic regions. Ingenuity Pathway Analysis revealed that methylation of promoter regions was altered in several genes involved in cancer and neurobehavioral disorders including CBFA2T3, PTPN6, COL18A1, ALDH2, UBE4B, ERBB2, GABRB3, CNTNAP4 and NIPA1. Our data reveal alterations of the human sperm epigenome associated with high-dose folic acid supplementation, effects that were exacerbated by a common polymorphism in MTHFR. PMID:26307085

  19. Meta-analyses of blood homocysteine levels for gender and genetic association studies of the MTHFR C677T polymorphism in schizophrenia.

    PubMed

    Nishi, Akira; Numata, Shusuke; Tajima, Atsushi; Kinoshita, Makoto; Kikuchi, Kumiko; Shimodera, Shinji; Tomotake, Masahito; Ohi, Kazutaka; Hashimoto, Ryota; Imoto, Issei; Takeda, Masatoshi; Ohmori, Tetsuro

    2014-09-01

    Previous studies suggest that elevated blood homocysteine levels and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism are risk factors for schizophrenia. However, the effects of gender and MTHFR C677T genotypes on blood homocysteine levels in schizophrenia have not been consistent. We first investigated whether plasma total homocysteine levels were higher in patients with schizophrenia than in controls with stratification by gender and by the MTHFR C677T genotypes in a large cohort (N = 1379). Second, we conducted a meta-analysis of association studies between blood homocysteine levels and schizophrenia separately by gender (N = 4714). Third, we performed a case-control association study between the MTHFR C677T polymorphism and schizophrenia (N = 4998) and conducted a meta-analysis of genetic association studies based on Japanese subjects (N = 10 378). Finally, we assessed the effect of plasma total homocysteine levels on schizophrenia by a mendelian randomization approach. The ANCOVA after adjustment for age demonstrated a significant effect of diagnosis on the plasma total homocysteine levels in all strata, and the subsequent meta-analysis for gender demonstrated elevated blood homocysteine levels in both male and female patients with schizophrenia although antipsychotic medication might influence the outcome. The meta-analysis of the Japanese genetic association studies demonstrated a significant association between the MTHFR C677T polymorphism and schizophrenia. The mendelian randomization analysis in the Japanese populations yielded an OR of 1.15 for schizophrenia per 1-SD increase in plasma total homocysteine. Our study suggests that increased plasma total homocysteine levels may be associated with an increased risk of schizophrenia.

  20. Association of PHB 1630 C>T and MTHFR 677 C>T polymorphisms with breast and ovarian cancer risk in BRCA1/2 mutation carriers: results from a multicenter study

    PubMed Central

    Jakubowska, A; Rozkrut, D; Antoniou, A; Hamann, U; Scott, R J; McGuffog, L; Healy, S; Sinilnikova, O M; Rennert, G; Lejbkowicz, F; Flugelman, A; Andrulis, I L; Glendon, G; Ozcelik, H; Thomassen, M; Paligo, M; Aretini, P; Kantala, J; Aroer, B; von Wachenfeldt, A; Liljegren, A; Loman, N; Herbst, K; Kristoffersson, U; Rosenquist, R; Karlsson, P; Stenmark-Askmalm, M; Melin, B; Nathanson, K L; Domchek, S M; Byrski, T; Huzarski, T; Gronwald, J; Menkiszak, J; Cybulski, C; Serrano, P; Osorio, A; Cajal, T R; Tsitlaidou, M; Benítez, J; Gilbert, M; Rookus, M; Aalfs, C M; Kluijt, I; Boessenkool-Pape, J L; Meijers-Heijboer, H E J; Oosterwijk, J C; van Asperen, C J; Blok, M J; Nelen, M R; van den Ouweland, A M W; Seynaeve, C; van der Luijt, R B; Devilee, P; Easton, D F; Peock, S; Frost, D; Platte, R; Ellis, S D; Fineberg, E; Evans, D G; Lalloo, F; Eeles, R; Jacobs, C; Adlard, J; Davidson, R; Eccles, D; Cole, T; Cook, J; Godwin, A; Bove, B; Stoppa-Lyonnet, D; Caux-Moncoutier, V; Belotti, M; Tirapo, C; Mazoyer, S; Barjhoux, L; Boutry-Kryza, N; Pujol, P; Coupier, I; Peyrat, J-P; Vennin, P; Muller, D; Fricker, J-P; Venat-Bouvet, L; Johannsson, O Th; Isaacs, C; Schmutzler, R; Wappenschmidt, B; Meindl, A; Arnold, N; Varon-Mateeva, R; Niederacher, D; Sutter, C; Deissler, H; Preisler-Adams, S; Simard, J; Soucy, P; Durocher, F; Chenevix-Trench, G; Beesley, J; Chen, X; Rebbeck, T; Couch, F; Wang, X; Lindor, N; Fredericksen, Z; Pankratz, V S; Peterlongo, P; Bonanni, B; Fortuzzi, S; Peissel, B; Szabo, C; Mai, P L; Loud, J T; Lubinski, J

    2012-01-01

    Background: The variable penetrance of breast cancer in BRCA1/2 mutation carriers suggests that other genetic or environmental factors modify breast cancer risk. Two genes of special interest are prohibitin (PHB) and methylene-tetrahydrofolate reductase (MTHFR), both of which are important either directly or indirectly in maintaining genomic integrity. Methods: To evaluate the potential role of genetic variants within PHB and MTHFR in breast and ovarian cancer risk, 4102 BRCA1 and 2093 BRCA2 mutation carriers, and 6211 BRCA1 and 2902 BRCA2 carriers from the Consortium of Investigators of Modifiers of BRCA1 and BRCA2 (CIMBA) were genotyped for the PHB 1630 C>T (rs6917) polymorphism and the MTHFR 677 C>T (rs1801133) polymorphism, respectively. Results: There was no evidence of association between the PHB 1630 C>T and MTHFR 677 C>T polymorphisms with either disease for BRCA1 or BRCA2 mutation carriers when breast and ovarian cancer associations were evaluated separately. Analysis that evaluated associations for breast and ovarian cancer simultaneously showed some evidence that BRCA1 mutation carriers who had the rare homozygote genotype (TT) of the PHB 1630 C>T polymorphism were at increased risk of both breast and ovarian cancer (HR 1.50, 95%CI 1.10–2.04 and HR 2.16, 95%CI 1.24–3.76, respectively). However, there was no evidence of association under a multiplicative model for the effect of each minor allele. Conclusion: The PHB 1630TT genotype may modify breast and ovarian cancer risks in BRCA1 mutation carriers. This association need to be evaluated in larger series of BRCA1 mutation carriers. PMID:22669161

  1. Polymorphism in one-carbon metabolism pathway affects survival of gastric cancer patients: Large and comprehensive study

    PubMed Central

    Huo, Xinying; Shen, Lili; Wang, Chun; Tang, Yongfei; Wu, Peng; He, Jason; Gong, Weida; He, Ming-Liang; Chen, Jinfei

    2015-01-01

    Although it has been shown that polymorphisms in one-carbon metabolism (OCM) pathway are associated with gastric cancer (GC), their interactions and contributions for patients’ survival are elusive. In this study, we investigated the effects of polymorphisms and their interactions on the survival of GC patients, including genes of Methylenetetrahydrofolate reductase (MTHFR 677C > T, 1298A > C), Methionine synthase reductase (MTRR 66A > G), Methionine synthase (MTR 2756A > G), and Thymidylate synthase (TS 3′-UTR ins6 > del6, 5′-UTR 2R > 3R). We recruited 919 GC patients from 1998 to 2006. The Kaplan–Meier plots, Cox regression analyses and the log-rank tests were carried out in this study. MTHFR 1298CC genotype showed protective effect (HR = 0.444, 95% CI = 0.210–0.940). MTRR 66 GA + GG genotypes decreased the risk of death (HR = 0.793, 95% CI = 0.651–0.967) in general, and in subgroups with more pronounced diffuse type, greater depth of invasion (T2/T3/T4), higher level lymph node metastasis (N1/N2/N3), advanced TNM stages (II/III level) and 5-Fu treatment. However, the improved survival disappeared when GC patients simultaneously had MTR 2756 GA + GG genotypes (HR = 1.063, 95% CI = 0.750–1.507). Although MTRR 66GA genotype was not associated with the survival of GC patients, patients with simultaneous MTRR 66GA and MTR 2756AA genotypes exhibited significant risk reduction of death (HR = 0.773, 95% CI = 0.609–0.981). MTHFR 1298 CA + CC combined with TS 5-UTR 2R3R + 3R3R genotypes (HR = 0.536, 95% CI = 0.315–0.913) also increased patient survival rates. Our results suggest that the MTRR 66A > G and MTHFR 1298A > C polymorphisms may be useful prognostic biomarkers for GC patients. PMID:25840420

  2. Plasminogen activator inhibitor-1 4G/5G and the MTHFR 677C/T polymorphisms and susceptibility to polycystic ovary syndrome: a meta-analysis.

    PubMed

    Lee, Young Ho; Song, Gwan Gyu

    2014-04-01

    The aim of this study was to explore whether the plasminogen activator inhibitor-1 (PAI-1) 4G/5G and the methylenetetrahydrofolate reductase (MTHFR) 677C/T polymorphisms are associated with susceptibility to polycystic ovary syndrome (PCOS). Meta-analyses were conducted to determine the association between the PAI-1 4G/5G and MTHFR 677C/T polymorphisms and PCOS using: (1) allele contrast (2) homozygote contrast, (3) recessive, and (4) dominant models. For meta-analysis, nine studies of the PAI-1 4G/5G polymorphism with 2384 subjects (PCOS, 1615; controls, 769) and eight studies of the MTHFR 677C/T polymorphism with 1270 study subjects were included. Meta-analysis of all study subjects showed no association between PCOS and the PAI-1 4G allele (OR=0.949, 95% CI=0.671-1.343, p=0.767). Stratification by ethnicity, however, indicated a significant association between the PAI-1 4G allele and PCOS in Turkish and Asian populations (OR=0.776, 95% CI=0.602-0.999, p=0.049; OR=1.749, 95% CI=1.297-2.359, p=2.5×10(-5) respectively). In addition, meta-analysis indicated an association between PCOS and the PAI-1 4G4G+4G5G genotype in Europeans (OR=1.406, 95% CI=1.025-1.928, p=0.035). However, meta-analysis of all study subjects showed no association between PCOS and the MTHFR 677T allele (OR=0.998, 95% CI=0.762-1.307, p=0.989), including Europeans (OR=0.806, 95% CI=0.610-1.063, p=0.126). Meta-analysis showed no association between PCOS and the MTHFR 677C/T polymorphism using homozygote contrast, and recessive and dominant models. In conclusion, meta-analysis suggests the PAI-1 4G/5G polymorphism is associated with susceptibility to PCOS in European, Turkish, and Asian populations, but the MTHFR 677C/T polymorphism is not associated with susceptibility to PCOS in Europeans.

  3. MTHFR C677T polymorphism and breast, ovarian cancer risk: a meta-analysis of 19,260 patients and 26,364 controls

    PubMed Central

    He, Lilin; Shen, Yongxiang

    2017-01-01

    Objective Previous studies have found that many gene variations can be detected in both breast cancer and ovarian cancer, which is beneficial for the elaboration of the molecular origin of breast and ovarian cancer. Furthermore, many studies have explored the association of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism with the risk of breast cancer and/or ovarian cancer; however, the results remained inconclusive. Therefore, this study conducted a systematic review and meta-analysis to evaluate the association between MTHFR C677T polymorphism and the risk of breast and ovarian cancer. Materials and methods A total of 50 studies with 19,260 cases and 26,364 controls including 39 studies for breast cancer and 8 studies for ovarian cancer were identified on searching through PubMed, Embase, Web of Science, China National Knowledge Infrastructure, WanFang, and Database of Chinese Scientific and Technical Periodicals (VIP). Allele model, dominant model, recessive model, homozygous model, and co-dominant model were applied to evaluate the association of MTHFR C677T polymorphism with breast cancer and/or ovarian cancer risk. Moreover, the odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of the association between MTHFR C677T polymorphism and breast and ovarian cancer risk. Results A significantly increased breast cancer risk was observed in the overall analysis (for C vs T, OR =1.19, CI: 1.12–1.28, P<0.05; for CC vs TT, OR =1.20, CI: 1.10–1.23, P<0.05; for (CT+CC) vs TT, OR =1.19, CI: 1.11–1.27, P<0.05; for CC vs (CT+TT), OR =1.19, CI: 1.79–1.95, P<0.05), while no significantly increased ovarian cancer risk was detected. In the subgroup analysis based on ethnicity, a significant association of breast cancer and/or ovarian cancer risk with MTHFR C677T polymorphism was observed in Asians. Interestingly, there was no significant association between MTHFR C677T polymorphism and ovarian cancer risk in

  4. Polymorphisms in MTHFR, MS and CBS Genes and Homocysteine Levels in a Pakistani Population

    PubMed Central

    Yakub, Mohsin; Moti, Naushad; Parveen, Siddiqa; Chaudhry, Bushra; Azam, Iqbal; Iqbal, Mohammad Perwaiz

    2012-01-01

    Background Hyperhomocysteinemia (>15 µmol/L) is highly prevalent in South Asian populations including Pakistan. In order to investigate the genetic determinants of this condition, we studied 6 polymorphisms in genes of 3 enzymes - methylenetetrahydrofolate reductase (MTHFR; C677T; A1298C), methionine synthase (MS; A2756G), cystathionine-β-synthase (CBS; T833C/844ins68, G919A) involved in homocysteine metabolism and investigated their interactions with nutritional and environmental factors in a Pakistani population. Methodology/Principal Findings In a cross-sectional survey, 872 healthy adults (355 males and 517 females; age 18–60 years) were recruited from a low-income urban population in Karachi. Fasting venous blood was obtained and assessed for plasma/serum homocysteine; folate, vitamin B12, pyridoxal phosphate and blood lead. DNA was isolated and genotyping was performed by PCR-RFLP (restriction-fragment-length- polymorphism) based assays. The average changes in homocysteine levels for MTHFR 677CT and TT genotypes were positive [β(SE β), 2.01(0.63) and 16.19(1.8) µmol/L, respectively]. Contrary to MTHFR C677T polymorphism, the average changes in plasma homocysteine levels for MS 2756AG and GG variants were negative [β(SE β), −0.56(0.58) and −0.83(0.99) µmol/L, respectively]. The average change occurring for CBS 844ins68 heterozygous genotype (ancestral/insertion) was −1.88(0.81) µmol/L. The combined effect of MTHFR C677T, MS A2756G and CBS 844ins68 genotypes for plasma homocysteine levels was additive (p value <0.001). Odds of having hyperhomocysteinemia with MTHFR 677TT genotype was 10-fold compared to MTHFR 677CC genotype [OR (95%CI); 10.17(3.6–28.67)]. Protective effect towards hyperhomocysteinemia was observed with heterozygous (ancestral/insertion) genotype of CBS 844ins68 compared to homozygous ancestral type [OR (95% CI); 0.58 (0.34–0.99)]. Individuals with MTHFR 677CT or TT genotypes were at a greater risk of hyperhomocysteinemia in

  5. The antihypertensive MTHFR gene polymorphism rs17367504-G is a possible novel protective locus for preeclampsia

    PubMed Central

    Thomsen, Liv Cecilie V.; McCarthy, Nina S.; Melton, Phillip E.; Cadby, Gemma; Austgulen, Rigmor; Nygård, Ottar K.; Johnson, Matthew P.; Brennecke, Shaun; Moses, Eric K.; Bjørge, Line; Iversen, Ann-Charlotte

    2017-01-01

    Objective: Preeclampsia is a complex heterogeneous disease commonly defined by new-onset hypertension and proteinuria in pregnancy. Women experiencing preeclampsia have increased risk for cardiovascular diseases (CVD) later in life. Preeclampsia and CVD share risk factors and pathophysiologic mechanisms, including dysregulated inflammation and raised blood pressure. Despite commonalities, little is known about the contribution of shared genes (pleiotropy) to these diseases. This study aimed to investigate whether genetic risk factors for hypertension or inflammation are pleiotropic by also being associated with preeclampsia. Methods: We genotyped 122 single nucleotide polymorphisms (SNPs) in women with preeclampsia (n = 1006) and nonpreeclamptic controls (n = 816) from the Norwegian HUNT Study. SNPs were chosen on the basis of previously reported associations with either nongestational hypertension or inflammation in genome-wide association studies. The SNPs were tested for association with preeclampsia in a multiple logistic regression model. Results: The minor (G) allele of the intronic SNP rs17367504 in the gene methylenetetrahydrofolate reductase (MTHFR) was associated with a protective effect on preeclampsia (odds ratio 0.65, 95% confidence interval 0.53–0.80) in the Norwegian cohort. This association did not replicate in an Australian preeclampsia case–control cohort (P = 0.68, odds ratio 1.05, 95% confidence interval 0.83–1.32, minor allele frequency = 0.15). Conclusion: MTHFR is important for regulating transmethylation processes and is involved in regulation of folate metabolism. The G allele of rs17367504 has previously been shown to protect against nongestational hypertension. Our study suggests a novel association between this allele and reduced risk for preeclampsia. This is the first study associating the minor (G) allele of a SNP within the MTHFR gene with a protective effect on preeclampsia, and in doing so identifying a

  6. Polymorphisms of Pyrimidine Pathway Enzymes Encoding Genes and HLA-B*40∶01 Carriage in Stavudine-Associated Lipodystrophy in HIV-Infected Patients

    PubMed Central

    Pruvost, Alain; Torres, Ferran; Salazar, Juliana; Gutierrez, Maria del Mar; Domingo, Joan Carles; Fernandez, Irene; Villarroya, Francesc; Vidal, Francesc; Baiget, Montserrat; de la Calle-Martín, Oscar

    2013-01-01

    Purpose To assess in a cohort of Caucasian patients exposed to stavudine (d4T) the association of polymorphisms in pyrimidine pathway enzymes and HLA-B*40∶01 carriage with HIV/Highly active antiretroviral therapy (HAART)-associated lipodystrophy syndrome (HALS). Methods Three-hundred and thirty-six patients, 187 with HALS and 149 without HALS, and 72 uninfected subjects were recruited. The diagnosis of HALS was performed following the criteria of the Lipodystrophy Severity Grading Scale. Polymorphisms in the thymidylate synthase (TS) and methylene-tetrahydrofolate reductase (MTHFR) genes were determined by direct sequencing, HLA-B genotyping by PCR-SSOr Luminex Technology, and intracellular levels of stavudine triphosphate (d4T-TP) by a LC-MS/MS assay method. Results HALS was associated with the presence of a low expression TS genotype polymorphism (64.7% vs. 42.9%, OR = 2.43; 95%CI: 1.53–3.88, P<0.0001). MTHFR gene polymorphisms and HLA-B*40∶01 carriage were not associated with HALS or d4T-TP intracellular levels. Low and high expression TS polymorphisms had different d4T-TP intracellular levels (25.60 vs. 13.60 fmol/106 cells, P<0.0001). Independent factors associated with HALS were(OR [95%CI]: (a) Combined TS and MTHFR genotypes (p = 0.006, reference category (ref.): ‘A+A’; OR for ‘A+B’ vs. ref.: 1.39 [0.69–2.80]; OR for ‘B+A’ vs. ref.: 2.16 [1.22–3.83]; OR for ‘B+B’ vs. ref.: 3.13, 95%CI: 1.54–6.35), (b) maximum viral load ≥5 log10 (OR: 2.55, 95%CI: 1.56–4.14, P = 0.001), (c) use of EFV (1.10 [1.00–1.21], P = 0.008, per year of use). Conclusion HALS is associated with combined low-expression TS and MTHFR associated with high activity polymorphisms but not with HLA-B*40∶01 carriage in Caucasian patients with long-term exposure to stavudine. PMID:23840581

  7. MTHFR C677T, A1298C and MS A2756G Gene Polymorphisms and Male Infertility Risk in a Chinese Population: A Meta-Analysis

    PubMed Central

    Yang, Bo; Fang, Kun; Ren, Shangqing; Liao, Jian; Liu, Shengzhuo; Liu, Liangren; Peng, Zhufeng; Dong, Qiang

    2017-01-01

    Background Methylenetetrahydrofolate reductase gene (MTHFR C677T and A1298C) and methionine synthase gene (MS A2756G) polymorphisms have shown an association with male infertility risk in several ethnic populations. Although several studies have evaluated these associations in Chinese populations, their small sample sizes and inconsistent outcomes have prevented strong conclusions. Therefore, the present meta-analysis was performed with published studies to evaluate the associations of the three single nucleotide polymorphisms (SNPs) and male infertility in a Chinese population. Methods We conducted a search of PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI), China biology medical literature (CBM), VIP, and Chinese literature (Wan Fang) databases up to May 31, 2016. Odds ratios (ORs) and 95% confidence intervals (95%CIs) were used to assess the strength of associations with a random-effect model or a fixed-effect model based on the heterogeneity analysis results. Sensitivity analysis was used to confirm the reliability and stability of the meta-analysis. Results A total of nine studies, including 1,713 cases and 1,104 controls, were included in the meta-analysis. The pooled results indicated that the MTHFR C667T polymorphism was significantly associated with increased risk of male infertility in the Chinese population in the allele model (T vs. C: OR = 1.47, 95%CI = 1.32–1.63), the dominant model (TT + CT vs. CC: OR = 1.51, 95%CI = 1.30–1.77), the additive model (TT vs. CC: OR = 2.08, 95%CI = 1.68–2.58) and the recessive model (TT vs. CT+CC: OR = 1.58, 95%CI = 1.31–1.90), whereas the MTHFR A1298C and MS A2756G polymorphisms were not risk factors. There was no significant heterogeneity in any genotype contrasts among the studies. The sensitivity analysis indicated that the results of this meta-analysis were relatively stable. Conclusion This study suggests that the MTHFR C667T polymorphism may contribute to the genetic

  8. Carbon-carbon double-bond reductases in nature.

    PubMed

    Huang, Minmin; Hu, Haihong; Ma, Li; Zhou, Quan; Yu, Lushan; Zeng, Su

    2014-08-01

    Reduction of C = C bonds by reductases, found in a variety of microorganisms (e.g. yeasts, bacteria, and lower fungi), animals, and plants has applications in the production of metabolites that include pharmacologically active drugs and other chemicals. Therefore, the reductase enzymes that mediate this transformation have become important therapeutic targets and biotechnological tools. These reductases are broad-spectrum, in that, they can act on isolation/conjugation C = C-bond compounds, α,β-unsaturated carbonyl compounds, carboxylic acids, acid derivatives, and nitro compounds. In addition, several mutations in the reductase gene have been identified, some associated with diseases. Several of these reductases have been cloned and/or purified, and studies to further characterize them and determine their structure in order to identify potential industrial biocatalysts are still in progress. In this study, crucial reductases for bioreduction of C = C bonds have been reviewed with emphasis on their principal substrates and effective inhibitors, their distribution, genetic polymorphisms, and implications in human disease and treatment.

  9. MTHFR C677T and MTR A2756G polymorphisms and the homocysteine lowering efficacy of different doses of folic acid in hypertensive Chinese adults

    PubMed Central

    2012-01-01

    Background This study aimed to investigate if the homocysteine-lowering efficacy of two commonly used physiological doses (0.4 mg/d and 0.8 mg/d) of folic acid (FA) can be modified by individual methylenetetrahydrofolate reductase (MTHFR) C677T and/or methionine synthase (MTR) A2756G polymorphisms in hypertensive Chinese adults. Methods A total of 480 subjects with mild or moderate essential hypertension were randomly assigned to three treatment groups: 1) enalapril only (10 mg, control group); 2) enalapril-FA tablet [10:0.4 mg (10 mg enalapril combined with 0.4 mg of FA), low FA group]; and 3) enalapril-FA tablet (10:0.8 mg, high FA group), once daily for 8 weeks. Results After 4 or 8 weeks of treatment, homocysteine concentrations were reduced across all genotypes and FA dosage groups, except in subjects with MTR 2756AG /GG genotype in the low FA group at week 4. However, compared to subjects with MTHFR 677CC genotype, homocysteine concentrations remained higher in subjects with CT or TT genotype in the low FA group (P < 0.05 for either of these genotypes) and TT genotype in the high FA group (P < 0.05). Furthermore, subjects with TT genotype showed a greater homocysteine-lowering response than did subjects with CC genotype in the high FA group (mean percent reduction of homocysteine at week 8: CC 10.8% vs. TT: 22.0%, P = 0.005), but not in the low FA group (CC 9.9% vs. TT 11.2%, P = 0.989). Conclusions This study demonstrated that MTHFR C677T polymorphism can not only affect homocysteine concentration at baseline and post-FA treatment, but also can modify therapeutic responses to various dosages of FA supplementation. PMID:22230384

  10. Hearing impairment risk and interaction of folate metabolism related gene polymorphisms in an aging study

    PubMed Central

    2011-01-01

    Background Recent investigations demonstrated many genetic contributions to the development of human age-related hearing impairment (ARHI), however, reports of factors associated with a reduction in the ARHI risk are rare. Folate metabolism is essential for cellular functioning. Despite the extensive investigations regarding the roles of folate metabolism related gene polymorphisms in the pathophysiology of complex diseases, such as cancer, cardio-cerebrovascular disease, and atherosclerosis, little is known about the association with ARHI. The aim of this study is to investigate the effects of the methionine synthase (MTR) A2756G and methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms on the risk of hearing impairment in middle-aged and elderly Japanese. Methods Data were collected from community-dwelling Japanese adults aged 40-84 years who participated in the Longitudinal Study of Aging biennially between 1997 and 2008. We analyzed cumulative data (5,167 samples in accumulated total) using generalized estimating equations. Results The MTHFR 677T allele was significantly associated with a reduced risk of hearing impairment only when the subjects were wild-type homozygotes for MTR A2756G. The per-T allele odds ratio of MTHFR for the risk of developing hearing impairment was 0.7609 (95% CI: 0.6178-0.9372) in the MTR AA genotype. In addition, a subgroup analysis demonstrated that the favorable effect of the MTHFR 677T allele on the risk of developing hearing impairment was independent of folate and homocysteine level, whereas plasma total homocysteine level was independently associated with an increased risk of developing hearing impairment. The interactive effect of gene polymorphisms associated with folate metabolism may modify the risk of developing hearing impairment after middle age. These results contribute to the elucidation of the causes of ARHI. Conclusions The present study has found that the MTHFR 677T allele has a favorable effect on a

  11. Population-level diversity in the association of genetic polymorphisms of one-carbon metabolism with breast cancer risk.

    PubMed

    Naushad, Shaik Mohammad; Divya, Chandrasekhar; Janaki Ramaiah, M; Hussain, Tajamul; Alrokayan, Salman A; Kutala, Vijay Kumar

    2016-10-01

    Aberrations in one-carbon metabolism were reported to increase breast cancer risk by influencing the DNA synthesis and methylation of DNA and catecholamines. However, the results of these association studies remain inconclusive. We have explored the contribution of eight genetic polymorphisms in modulating the susceptibility to breast cancer by performing a meta-analysis of worldwide studies. In total, 62 case-control studies representing 17 different populations involving 18,117 breast cancer cases and 23,573 healthy controls were included in this meta-analysis. Out of the eight polymorphisms analyzed, methylenetetrahydrofolate reductase (MTHFR) C677T exhibited positive association with the breast cancer risk in both fixed effects (OR 1.14, 95 % CI 1.10-1.17) and random effects (OR 1.10, 95 % CI 1.02-1.18) models. Solute carrier family 19 (folate transporter), member 1 (SLC19A1) G80A exhibited positive association (OR 1.16, 95 % CI 1.03-1.31) while MTR A2756G exhibited an inverse association (OR 0.78, 95 % CI 0.75-0.82) with the breast in fixed effect model alone. Significant heterogeneity was observed in the association of MTHFR C677T with breast cancer even between studies from the same geographical area, specifically among Chinese, Indians, and Turks. Subgroup analysis revealed MTHFR C677T-mediated breast cancer risk in post-menopausal women and women with low dietary intake of folate. Geographical area wise segregation of data revealed MTHFR-mediated increased breast cancer risk in populations who consume methionine-rich diet. Altitude-level variations were observed in the association of SHMT1 C1420T with breast cancer. India and Brazil of same altitude showed an inverse association with this polymorphism, while USA and China that share similar altitude showed a null association. MTHFR C677T and SLC19A1 G80A are the two polymorphisms of one-carbon metabolic pathway that increase breast cancer in the worldwide population. Dietary patterns and altitudinal

  12. Screening for C677T and A1298C MTHFR polymorphisms in patients with epilepsy and risk of hyperhomocysteinemia.

    PubMed

    Caccamo, D; Condello, S; Gorgone, G; Crisafulli, G; Belcastro, V; Gennaro, S; Striano, P; Pisani, F; Ientile, R

    2004-01-01

    Hyperhomocysteinemia can result from decreased methylenetetrahydrofolate reductase (MTHFR) enzyme activity, owing to genetic polymorphisms andor inadequate folate intake. This study was aimed at investigating the prevalence of C677T and A1298C MTHFR polymorphisms, and their impact on hyperhomocysteinemia in 95 epileptic patients and 98 controls. Double gradient-denaturing gradient gel electrophoresis screening revealed that the frequency of T677 polymorphic allele was similar between cases and controls (46.3% vs 42.3%), whereas that of C1298 allele was significantly higher in patients (30.5% vs 19.4%, p < 0.05). Significant differences between the two groups were also found for the frequencies of genotypes AA1298 (46.3% in cases vs 67.3% in controls, p < 0.01) and AC1298 (46.3% in cases vs 26.6% in controls, p < 0.01). Other genotype frequencies did not show any statistically significant differences. Haplotype frequencies significantly differed between the two groups. The CT677/AC1298 diplotype was significantly more frequent in epileptic patients than in controls (32.6% vs 18.4%, p < 0.05). Patients treated with enzyme-inducing antiepileptic drugs, having this diplotype and concomitant low folate concentration (i.e., < 3.4 nmol/L), exhibited plasma homocysteine levels significantly higher than normal values (27.1 +/- 2.44 micromol/L, p < 0.001). This increase, however, was lower than that observed in folate-deficient patients with diplotype TT677/AA1298 (41.3 +/- 3.41 micromol/L, p < 0.001). Indeed, these two diplotypes could be regarded as risk factors for hyperhomocysteinemia. Conversely, we found that the CC677/AA1298 diplotype was significantly more frequent in controls (p < 0.01), suggesting a protective role. Our study suggests that both C677T and A1298C MTHFR polymorphisms should be examined when assessing genetic risk factors of hyperhomocysteinemia in epilepsy.

  13. Coenzyme Q10, hyperhomocysteinemia and MTHFR C677T polymorphism in levodopa-treated Parkinson's disease patients.

    PubMed

    Gorgone, Gaetano; Currò, Monica; Ferlazzo, Nadia; Parisi, Giulia; Parnetti, Lucilla; Belcastro, Vincenzo; Tambasco, Nicola; Rossi, Aroldo; Pisani, Francesco; Calabresi, Paolo; Ientile, Riccardo; Caccamo, Daniela

    2012-03-01

    There is evidence that increased homocysteine (Hcy) levels might accelerate dopaminergic cell death in Parkinson's disease (PD) through neurotoxic effects. Homocysteine neurotoxicity mainly relies on redox state alterations. The present work was aimed at investigating the relationships between plasma Hcy concentrations and percent content of oxidized versus total Coenzyme Q10 (%CoQ10) in 60 PD patients and 82 healthy subjects. Both groups were screened for plasma levels of Hcy, vitamin B12, folate, %CoQ10 and C677T methylenetetrahydrofolate reductase (MTHFR) gene polymorphism. The MTHFR TT677 mutated genotype was found more frequently in patients than in controls (p = 0.01). In a multivariate analysis, Hcy levels and %CoQ10 were associated with the case/control category (p < 0.0001), MTHFR genotype (p < 0.0001) and their interaction term (p = 0.0015), even after adjusting for age, sex, folate and vitamin B12. Patients carrying the TT677 genotype exhibited the highest values of Hcy and %CoQ10 (p < 0.0001). Structural equation modelling evidenced that the TT677 genotype and levodopa daily dose were independently and directly correlated with Hcy (p < 0.0001, and p = 0.003, respectively), which, in turn, showed a significant correlation (p < 0.0001) with the %CoQ10 in PD patients. Our results suggest that increased Hcy levels act as mediator of the systemic oxidative stress occurring in PD, and %CoQ10 determination might be regarded as a predictor of toxic Hcy effects.

  14. Dietary intake of folate, vitamin B6, and vitamin B12, genetic polymorphism of related enzymes, and risk of breast cancer: a case-control study in Brazilian women

    PubMed Central

    2009-01-01

    Background Several studies have determined that dietary intake of B vitamins may be associated with breast cancer risk as a result of interactions between 5,10-methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MTR) in the one-carbon metabolism pathway. However, the association between B vitamin intake and breast cancer risk in Brazilian women in particular has not yet been investigated. Methods A case-control study was conducted in São Paulo, Brazil, with 458 age-matched pairs of Brazilian women. Energy-adjusted intakes of folate, vitamin B6, and vitamin B12 were derived from a validated Food Frequency Questionnaire (FFQ). Genotyping was completed for MTHFR A1298C and C677T, and MTR A2756G polymorphisms. A logistical regression model was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). Results Neither dietary intake of folate, vitamin B6, or vitamin B12 nor MTHFR polymorphisms were independently associated with breast cancer risk. Analysis stratified by menopausal status showed a significant association between placement in the highest tertile of folate intake and risk of breast cancer in premenopausal women (OR = 2.17, 95% CI: 1.23–3.83; Ptrend = 0.010). The MTR 2756GG genotype was associated with a higher risk of breast cancer than the 2756AA genotype (OR = 1.99, 95% CI = 1.01–3.92; Ptrend = 0.801), and statistically significant interactions with regard to risk were observed between the MTHFR A1298C polymorphism and folate (P = 0.024) or vitamin B6 (P = 0.043), and between the MTHFR C677T polymorphism and folate (P = 0.043) or vitamin B12 (P = 0.022). Conclusion MTHFR polymorphisms and dietary intake of folate, vitamin B6, and vitamin B12 had no overall association with breast cancer risk. However, increased risk was observed in total women with the MTR 2756GG genotype and in premenopausal women with high folate intake. These findings, as well as significant interactions between MTHFR polymorphisms and B vitamins

  15. The Frequency of Some Thrombophilic Mutations in Eastern Turkey

    PubMed Central

    Ozturk, Nurinnisa; Bakan, Ebubekir; Gul, Mehmet Ali; Bakan, Nuri; Sebin, Engin; Kiziltunc, Ahmet

    2016-01-01

    Objective: Factor V / Factor II / Methylenetetrahydrofolate reductase, gene polymorphisms are closely associated with thrombophilia. Regional frequencies of these mutations may show a characteristic state. The aim of our study was to evaluate the frequency of commonly seen Factor V / Factor II / Methylenetetrahydrofolate reductase gene polymorphisms in Eastern Turkey. Materials and Methods: In 433 patients sent to the laboratory with the suspicion of thrombophilia, using whole blood samples, an automated Nucleic Acid Test was used for mutation determinations in Verigene System. The kit module was designed to detect the Factor V G1691A / Factor II G20210A / Methylenetetrahydrofolate reductase gene C677T single nucleotide polymorphisms. Results: In 433 patients, 8.7% for Factor V G1691A polymorphisms were heterozygous genotype, 3.9% for Factor II G20210A polymorphisms were heterozygous genotype, and 43.9% for methylenetetrahydrofolate reductase 677C>T polymorphisms were heterozygous genotype and 3.0% homozygous mutation genotype. Conclusion: Detection of these commonly seen Factor V / Factor II / Methylenetetrahydrofolate reductase single nucleotide polymorphisms can help to identify patients in high risk group and to evaluate the interaction of genetic and acquired risk factors. Our findings suggest that commonly seen thrombophilic allele mutation frequency in our region is the same as the data reported in the literature. PMID:27026755

  16. Genetic polymorphism of MTHFR C677T and premature coronary artery disease susceptibility: A meta-analysis.

    PubMed

    Hou, Xiaowen; Chen, Xin; Shi, Jingpu

    2015-07-01

    The association between 5, 10-methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism and premature coronary artery disease (PCAD) is controversial. To explore a more precise estimation of the association, a meta-analysis was conducted in the present study. The relevant studies were identified by searching PubMed, EMBASE, the Web of Science, Cochrane Collaboration Database, Chinese National Knowledge Infrastructure, Wanfang Database and China Biological Medicine up to November, 2014. The meta-analysis was performed by STATA 11. 21 studies with a total of 6912 subjects, including 2972 PCAD patients and 3940 controls. The pooled analysis showed that MTHFR C677T gene polymorphism was probably associated with PCAD (CT vs. CC: OR=1.13, 95% CI=1.01-1.27; dominant model: OR=1.16, 95% CI=1.04-1.29; recessive model: OR=1.19, 95% CI=1.00-1.40; allele analysis: OR=1.17, 95% CI=1.01-1.34). Subgroup analysis by plasma homocysteine concentration showed a significant association in the homocysteine >15μmol/L subgroup (CT vs. CC: OR=1.44, 95% CI=1.10-1.88; TT vs. CC: OR=2.51, 95% CI=1.12-5.63; dominant model: OR=1.51, 95% CI=1.16-1.96; recessive model: OR=2.33, 95% CI=1.05-5.20; allele analysis: OR=1.48, 95% CI=1.18-1.87). Subgroup analysis by continent displayed a significant association among the Asian population (CT vs. CC: OR=1.51, 95% CI=1.23-1.86; TT vs. CC: OR=2.81, 95% CI=1.87-4.23; dominant model: OR=1.65, 95% CI=1.35-2.01; recessive model: OR=2.22, 95% CI=1.53-3.21; allele analysis: OR=1.61, 95% CI=1.37-1.89). The statistical stability and reliability was demonstrated by sensitivity analysis and publication bias outcomes. In conclusion, the meta-analysis suggests that MTHFR C677T gene polymorphism may be associated with PCAD.

  17. Nitrate and periplasmic nitrate reductases

    PubMed Central

    Sparacino-Watkins, Courtney; Stolz, John F.; Basu, Partha

    2014-01-01

    The nitrate anion is a simple, abundant and relatively stable species, yet plays a significant role in global cycling of nitrogen, global climate change, and human health. Although it has been known for quite some time that nitrate is an important species environmentally, recent studies have identified potential medical applications. In this respect the nitrate anion remains an enigmatic species that promises to offer exciting science in years to come. Many bacteria readily reduce nitrate to nitrite via nitrate reductases. Classified into three distinct types – periplasmic nitrate reductase (Nap), respiratory nitrate reductase (Nar) and assimilatory nitrate reductase (Nas), they are defined by their cellular location, operon organization and active site structure. Of these, Nap proteins are the focus of this review. Despite similarities in the catalytic and spectroscopic properties Nap from different Proteobacteria are phylogenetically distinct. This review has two major sections: in the first section, nitrate in the nitrogen cycle and human health, taxonomy of nitrate reductases, assimilatory and dissimilatory nitrate reduction, cellular locations of nitrate reductases, structural and redox chemistry are discussed. The second section focuses on the features of periplasmic nitrate reductase where the catalytic subunit of the Nap and its kinetic properties, auxiliary Nap proteins, operon structure and phylogenetic relationships are discussed. PMID:24141308

  18. Aberrant DNA Methylation of P16, MGMT, and hMLH1 Genes in Combination with MTHFR C677T Genetic Polymorphism in gastric cancer

    PubMed Central

    Song, Binbin; Ai, Jiang; Kong, Xianghong; Liu, Dexin; Li, Jun

    2013-01-01

    Objective: We aimed to explore the association of P16, MGMT and HMLH1 with gastric cancer and their relation with Methylenetetrahydrofolate reductase (MTHFR). Methods: 322 gastric patients who were confirmed with pathological diagnosis were included in our study. Aberrant DNA methylation of P16, MGMT and HMLH1 and polymorphisms of MTHFR C677T and A1298C were detected using PCR-RFLP. Results: The proportions of DNA hypermethylation in P16, MGMT and hMLH1 genes in gastric cancer tissues were 75.2% (242/322), 27.6% (89/322) and 5.3% (17/322), respectively. In the remote normal-appearing tissues, 29.5% (95/322) and 16.1%(52/322) showed hypermethylation in P16 and MGMT genes, respectively. We found a significantly higher proportion of DNA hypermethylation of P16 in patients with N1 TNM stage in cancer tissues and remote normal-appearing tissues (P<0.05). Similarly, we found DNA hypermethylation of MGMT had significantly higher proportion in N1 and M1 TNM stage (P<0.05). Individuals with homozygotes (TT) of MTHFR C677T had significant risk of DNA hypermethylation of MGMT in cancer tissues [OR (95% CI)=4.27(1.76-7.84)], and a significant risk was also found in those carrying MTHFR 677CT/TT genotype [OR (95% CI)= 3.27(1.21-4.77)]. Conclusion: We found the aberrant hypermethylation of cancer-related genes, such as P16, MGMT and HMLH1, could be predictive biomarkers for detection of gastric cancer. PMID:24550949

  19. Effect of polymorphisms of the MTHFR and APOE genes on susceptibility to diabetes and severity of diabetic retinopathy in Brazilian patients.

    PubMed

    Errera, F I V; Silva, M E R; Yeh, E; Maranduba, C M C; Folco, B; Takahashi, W; Pereira, A C; Krieger, J E; Passos-Bueno, M R

    2006-07-01

    Diabetes mellitus (DM) is a highly prevalent complex genetic disorder. There has been a worldwide effort in the identification of susceptibility genes for DM and its complications, and the 5-10-methylenetetrahydrofolate reductase (MTHFR) and apolipoprotein-E (APOE) genes have been considered good candidate susceptibility genes to this condition. The objectives of the present study were to determine if the 677T MTHFR and epsilon2/epsilon3/epsilon4 APOE alleles are risk factors for DM and for severity of diabetic retinopathy (DR). A total of 248 individuals were studied: 107 healthy individuals and 141 diabetic patients (46 with type 1 diabetes and 95 with type 2 diabetes), who also had DR (81 with non-proliferative DR and 60 with proliferative DR). The polymorphisms were analyzed by PCR followed by digestion with restriction enzyme or the single-nucleotide primer extension method. No evidence of association between the 677TT genotype of MTHFR gene and DM [cases: TT = 10/95 (10.6%); controls: TT = 14/107 (13%)] or with severity of DR was observed [cases: TT = 5/60 (8.5%); controls: TT = 9/81 (11.1%); P > 0.05]. We also did not find evidence of an association between APOE alleles and proliferative DR (epsilon2, epsilon3 and epsilon4 in cases: 9, 76, and 15%, and in controls: 5, 88, and 12%, respectively) but the carriers of epsilon2 allele were more frequent among patients with type 2 DM and DR than in controls [cases: 15/95 (15.8%); controls: 7/107 (6.5%); P < 0.05]. Therefore, our results suggest that the epsilon2 allele/APOE might be a risk factor for diabetes in the Brazilian population.

  20. Polymorphic variants of cytochrome P450 2B6 (CYP2B6.4-CYP2B6.9) exhibit altered rates of metabolism for bupropion and efavirenz: a charge-reversal mutation in the K139E variant (CYP2B6.8) impairs formation of a functional cytochrome p450-reductase complex.

    PubMed

    Zhang, Haoming; Sridar, Chitra; Kenaan, Cesar; Amunugama, Hemali; Ballou, David P; Hollenberg, Paul F

    2011-09-01

    In this study, metabolism of bupropion, efavirenz, and 7-ethoxy-4-trifluoromethylcoumarin (7-EFC) by CYP2B6 wild type (CYP2B6.1) and six polymorphic variants (CYP2B6.4 to CYP2B6.9) was investigated in a reconstituted system to gain a better understanding of the effects of the mutations on the catalytic properties of these naturally occurring variants. All six variants were successfully overexpressed in Escherichia coli, including CYP2B6.8 (the K139E variant), which previously could not be overexpressed in mammalian COS-1 cells (J Pharmacol Exp Ther 311:34-43, 2004). The steady-state turnover rates for the hydroxylation of bupropion and efavirenz and the O-deethylation of 7-EFC showed that these mutations significantly alter the catalytic activities of CYP2B6. It was found that CYP2B6.6 exhibits 4- and 27-fold increases in the K(m) values for the hydroxylation of bupropion and efavirenz, respectively, and CYP2B6.8 completely loses its ability to metabolize any of the substrates under normal turnover conditions. However, compared with CYP2B6.1, CYP2B6.8 retains 77% of its 7-EFC O-deethylase activity in the presence of tert-butyl hydroperoxide as an alternative oxidant, indicating that the heme and the active site are catalytically competent. Presteady-state measurements of the rate of electron transfer from NADPH-dependent cytochrome P450 reductase (CPR) to CYP2B6.8 using stopped-flow spectrophotometry revealed that CYP2B6.8 is incapable of accepting electrons from CPR. These observations provide conclusive evidence suggesting that the charge-reversal mutation in the K139E variant prevents CYP2B6.8 from forming a functional complex with CPR. Results from this work provide further insights to better understand the genotype-phenotype correlation regarding CYP2B6 polymorphisms and drug metabolism.

  1. Association of Thymidylate Synthase Polymorphisms with Acute Pancreatitis and/or Peripheral Neuropathy in HIV-Infected Patients on Stavudine-Based Therapy

    PubMed Central

    Torres, Ferran; Salazar, Juliana; Gutierrez, Maria del Mar; Mateo, Maria Gracia; Martínez, Esteban; Domingo, Joan Carles; Fernandez, Irene; Villarroya, Francesc; Ribera, Esteban; Vidal, Francesc; Baiget, Montserrat

    2013-01-01

    Background Low expression thymidylate synthase (TS) polymorphism has been associated with increased stavudine triphosphate intracellular (d4T-TP) levels and the lipodystrophy syndrome. The use of d4T has been associated with acute pancreatitis and peripheral neuropathy. However, no relationship has ever been proved between TS polymorphisms and pancreatitis and/or peripheral neuropathy. Methods We performed a case-control study to assess the relationship of TS and methylene-tetrahydrofolate reductase (MTHFR) gene polymorphisms with acute pancreatitis and/or peripheral neuropathy in patients exposed to d4T. Student’s t test, Pearson’s correlations, one-way ANOVA with Bonferroni correction and stepwise logistic regression analyses were done. Results Forty-three cases and 129 controls were studied. Eight patients (18.6%) had acute pancreatitis, and 35 (81.4%) had peripheral neuropathy. Prior AIDS was more frequent in cases than in controls (OR = 2.36; 95%CI 1.10–5.07, P = 0.0247). L7ow expression TS and MTHFR genotype associated with increased activity were more frequent in patients with acute pancreatitis and/or peripheral neuropathy than in controls (72.1% vs. 46.5%, OR = 2.97; 95%CI: 1.33–6.90, P = 0.0062, and 79.1% vs. 56.6%, OR = 2.90, 95%CI: 1.23–7.41, P = 0.0142, respectively). Independent positive or negative predictors for the development of d4T-associated pancreatitis and/or peripheral neuropathy were: combined TS and MTHFR genotypes (reference: A+A; P = 0.002; ORA+B = 0.34 [95%CI: 0.08 to 1.44], ORB+A = 3.38 [95%CI: 1.33 to 8.57], ORB+B = 1.13 [95%CI: 0.34 to 3.71]), nadir CD4 cell count >200 cells/mm3 (OR = 0.38; 95%CI: 0.17–0.86, P = 0.021), and HALS (OR = 0.39 95%CI: 0.18–0.85, P = 0.018). Conclusions Low expression TS plus a MTHFR genotype associated with increased activity is associated with the development of peripheral neuropathy in d4T-exposed patients. PMID:23468971

  2. Zeatin reductase in Phaseolus embryos

    SciTech Connect

    Martin, R.C.; Mok, David, W.S.; Mok, M.C. )

    1989-04-01

    Zeatin was converted to O-xylosylzeatin in embryos of Phaseolus vulgaris . O-xylosyldihydrozeatin was also identified as a zeatin metabolite. Incubation of embryo extracts with {sup 14}C-zeatin and {sup 14}C-O-xylosylzeatin revealed that reduction preceeds the O-xylosylation of zeatin. An enzyme responsible for reducing the N{sup 6}-side chain was isolated and partially purified using ammonium sulfate fractionation and affinity, gel filtration and anion exchange chromatography. The NADPH dependent reductase was zeatin specific and did not recognize cis-zeatin, ribosylzeatin, i{sup 6}Ade or i{sup 6}Ado. Two forms of the reductase could be separated by either gel filtration or anion exchange HPLC. The HMW isozyme (Mr. 55,000) eluted from the anion exchange column later than the LMW isozyme (Mr. 25,000). Interspecific differences in zeatin reductase activity were also detected.

  3. Polymorphisms in genes involved in folate metabolism modify the association of dietary and circulating folate and vitamin B-6 with cervical neoplasia.

    PubMed

    Tomita, Luciana Y; D'Almeida, Vania; Villa, Luisa L; Franco, Eduardo L; Cardoso, Marly A

    2013-12-01

    High folate intake has been suggested as an important factor in cancer prevention; however, previous studies on the relation among folate intake, serum folate, and plasma homocysteine (hcy) are controversial. We conducted a hospital-based, case-control study in Brazil investigating associations between dietary and circulating vitamins B-6 and B-12 and folate, hcy, genotypes of folate-metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR C677T, A1298C), 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR A2756G), methionine synthase reductase (MTRR A66G), and reduced folate carrier (RFC1 G80A) and risk of cervical intraepithelial neoplasia (CIN) grades 1 (CIN1), 2 (CIN2), and 3 (CIN3). The study was composed by 453 controls, 140 CIN1, 126 CIN2, and 231 CIN3. We investigated the joint effects of genetic variants of folate-related genes using genetic risk scores (GRSs) by summing the number of risk alleles for CIN1 and CIN2+ (CIN2 and CIN3 cases). The OR (95% CI) for CIN1 and CIN2+ per each risk allele were 1.29 (1.01, 1.65) and 1.22 (1.01, 1.46), respectively. An association between folate intake and CIN2+ was observed only after stratification according to GRS: crude OR (95% CI) for lower folate intake and GRS ≥ 4 was 1.67 (0.92, 3.04) (P-trend < 0.001) compared with higher folate intake (above the median) and GRS ≤ 3. The CIN2+ risk of lower serum vitamin B-6 and GRS ≥ 4 was 2.14 (0.92, 5.02) (P-trend = 0.05) and lower serum folate (below the median) and GRS ≥ 4 was 0.49 (0.20, 1.17) (P-trend = 0.05) after adjustment for confounding variables and human papillomavirus infection. Our data suggest that polymorphisms in genes related to folate metabolism modify the association of dietary and circulating folate and vitamin B-6 with cervical neoplasia.

  4. Isolated menthone reductase and nucleic acid molecules encoding same

    DOEpatents

    Croteau, Rodney B; Davis, Edward M; Ringer, Kerry L

    2013-04-23

    The present invention provides isolated menthone reductase proteins, isolated nucleic acid molecules encoding menthone reductase proteins, methods for expressing and isolating menthone reductase proteins, and transgenic plants expressing elevated levels of menthone reductase protein.

  5. Relationship of MTHFR Gene 677C→T Polymorphism, Homocysteine, and Estimated Glomerular Filtration Rate Levels With the Risk of New-Onset Diabetes

    PubMed Central

    Qin, Xianhui; Li, Youbao; Yuan, Hui; Xie, Di; Tang, Genfu; Wang, Binyan; Wang, Xiaobin; Xu, Xin; Xu, Xiping; Hou, Fanfan

    2015-01-01

    Abstract East Asian patients with diabetes have a higher risk for renal complications and strokes than Europeans. We aimed to evaluate the effect of methylenetetrahydrofolate reductase (MTHFR) gene 677C→T polymorphism, which was associated with a higher stroke risk and was common in the Chinese population, as well as homocysteine and estimated glomerular filtration rate (eGFR) levels on the risk of new-onset diabetes (NOD). A total of 2422 subjects without diabetes were followed-up for 7 years. NOD was defined as fasting plasma glucose ≥7.0 mmol/L or self-reported physician diagnosis of diabetes. Compared with subjects with MTHFR 677CC genotype, those with TT genotype had a higher risk of NOD in females (odds ratio 2.78, 95% confidence interval 1.39–5.56) but not in males (0.80, 0.40–1.61, P for interaction = 0.008). Furthermore, MTHFR 677C→T polymorphism was more strongly associated with the risk of NOD among females with higher body mass index (BMI, ≥23 vs <23 kg/m2, P for interaction = 0.009) or lower high-density lipoprotein-cholesterol (HDL-C, <1.3 vs ≥1.3 mmol/L, P for interaction = 0.015) levels. Hyperhomocysteinemia (≥16 vs <10 μmol/L) was not significantly associated with NOD in males (0.88, 0.42–1.85) or females (1.52, 0.65–3.57). However, mildly decreased eGFR (<90 vs 90–120 mL/min/1.73 m2) was associated with NOD mainly in males (1.96, 1.01–3.78; females, 0.74, 0.32–1.72, P for interaction = 0.134). Females with MTHFR 677TT genotype had a significantly higher risk of NOD, particularly those with higher BMI or low HDL-C levels. The higher risk of NOD associated with mildly decreased eGFR also warrants more investigation. Our results provide insights into the ethnic differences of diabetic complications between East Asian patients and Europeans. PMID:25700330

  6. Nitrate reductase from Rhodopseudomonas sphaeroides.

    PubMed Central

    Kerber, N L; Cardenas, J

    1982-01-01

    The facultative phototroph Rhodopseudomonas sphaeroides DSM158 was incapable of either assimilating or dissimilating nitrate, although the organism could reduce it enzymatically to nitrite either anaerobically in the light or aerobically in the dark. Reduction of nitrate was mediated by a nitrate reductase bound to chromatophores that could be easily solubilized and functioned with chemically reduced viologens or photochemically reduced flavins as electron donors. The enzyme was solubilized, and some of its kinetic and molecular parameters were determined. It seemed to be nonadaptive, ammonia did not repress its synthesis, and its activity underwent a rapid decline when the cells entered the stationary growth phase. Studies with inhibitors and with metal antagonists indicated that molybdenum and possibly iron participate in the enzymatic reduction of nitrate. The conjectural significance of this nitrate reductase in phototrophic bacteria is discussed. PMID:6978883

  7. Fatty acyl-CoA reductase

    SciTech Connect

    Reiser, Steven E.; Somerville, Chris R.

    1998-12-01

    The present invention relates to bacterial enzymes, in particular to an acyl-CoA reductase and a gene encoding an acyl-CoA reductase, the amino acid and nucleic acid sequences corresponding to the reductase polypeptide and gene, respectively, and to methods of obtaining such enzymes, amino acid sequences and nucleic acid sequences. The invention also relates to the use of such sequences to provide transgenic host cells capable of producing fatty alcohols and fatty aldehydes.

  8. The C677T mutation of the 5,10-methylenetetrahydrofolate reductase gene is a moderate risk factor for spina bifida in Italy.

    PubMed Central

    de Franchis, R; Buoninconti, A; Mandato, C; Pepe, A; Sperandeo, M P; Del Gado, R; Capra, V; Salvaggio, E; Andria, G; Mastroiacovo, P

    1998-01-01

    OBJECTIVE: To estimate the risk for spina bifida associated with the common mutation C677T of the MTHFR gene in a country with a relatively low prevalence of NTDs. DESIGN: Case-control study. SUBJECTS: Cases: 203 living patients affected with spina bifida (173 myelomeningocele and 30 lipomeningocele); controls: 583 subjects (306 young adults and 277 unselected newborns) from northern and central-southern Italy. SETTING: Cases: three spina bifida centres; young adult controls: DNA banks; newborn controls: regional neonatal screening centres. MAIN OUTCOME MEASURES: Prevalence of the C677T genotypes in cases and controls by place of birth; odds ratios for spina bifida and estimated attributable fraction. RESULTS: The prevalence of T/T, T/C, and C/C genotype was 16.6%, 53.7%, and 29.7% in controls and 25.6%, 43.8%, and 30.6% in cases, respectively. We found no differences between type of defect or place of birth. The odds ratio for spina bifida associated with the T/T genotype v C/C plus T/C was 1.73 (95% CI 1.15, 2.59) and the corresponding attributable fraction was 10.8%. No increased risk was found for heterozygous patients (OR=0.79, 95% CI 0.53-1.18). CONCLUSION: This study, as well as the meta-analysis we updated, shows that homozygosity for the MTHFR C677T mutation is a moderate risk factor in Europe, and even in Italy where there is a relatively low prevalence of spina bifida. The estimated attributable fraction associated with this risk factor explains only a small proportion of cases preventable by periconceptional folic acid supplementation. Thus, other genes involved in folate-homocysteine metabolism, their interaction, and the interaction between genetic and environmental factors should be investigated further. PMID:9863598

  9. EVALUATION OF INFANT METHYLENETETRAHYDROFOLATE REDUCTASE GENOTYPE, MATERNAL VITAMIN USE, AND RISK OF HIGH VERSUS LOW LEVEL SPINA BIFIDA DEFECTS. (R828292)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  10. Chromosomal localization of the gene for the human trifunctional enzyme, methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase-formyltetrahydrofolate synthetase.

    PubMed Central

    Rozen, R; Barton, D; Du, J; Hum, D W; MacKenzie, R E; Francke, U

    1989-01-01

    A trifunctional protein in man, 5,10-methylenetetrahydrofolate dehydrogenase-5,10-methenyltetrahydrofolate cyclohydrolase-10-formyltetrahydrofolate synthetase, catalyzes three consecutive steps in the interconversion of tetrahydrofolate derivatives; these derivatives supply one-carbon units for intermediary metabolism. Somatic cell hybridization and in situ hybridization were used to localize the functional gene coding for this protein--to human chromosome 14q24, near the c-fos and TGF-beta 3 loci. A second hybridizing sequence, possibly a pseudogene, was identified near the centromere of the X chromosome, at Xp11. Images Figure 1 PMID:2786332

  11. Nitrate Reductase Regulates Expression of Nitrite Uptake and Nitrite Reductase Activities in Chlamydomonas reinhardtii 1

    PubMed Central

    Galván, Aurora; Cárdenas, Jacobo; Fernández, Emilio

    1992-01-01

    In Chlamydomonas reinhardtii mutants defective at the structural locus for nitrate reductase (nit-1) or at loci for biosynthesis of the molybdopterin cofactor (nit-3, nit-4, or nit-5 and nit-6), both nitrite uptake and nitrite reductase activities were repressed in ammonium-grown cells and expressed at high amounts in nitrogen-free media or in media containing nitrate or nitrite. In contrast, wild-type cells required nitrate induction for expression of high levels of both activities. In mutants defective at the regulatory locus for nitrate reductase (nit-2), very low levels of nitrite uptake and nitrite reductase activities were expressed even in the presence of nitrate or nitrite. Both restoration of nitrate reductase activity in mutants defective at nit-1, nit-3, and nit-4 by isolating diploid strains among them and transformation of a structural mutant upon integration of the wild-type nit-1 gene gave rise to the wild-type expression pattern for nitrite uptake and nitrite reductase activities. Conversely, inactivation of nitrate reductase by tungstate treatment in nitrate, nitrite, or nitrogen-free media made wild-type cells respond like nitrate reductase-deficient mutants with respect to the expression of nitrite uptake and nitrite reductase activities. Our results indicate that nit-2 is a regulatory locus for both the nitrite uptake system and nitrite reductase, and that the nitrate reductase enzyme plays an important role in the regulation of the expression of both enzyme activities. PMID:16668656

  12. [The different genotypes of MTHFR 1298A>C and PON1 -108C>T polymorphisms confer the increased risk of the abdominal aortic aneurysm in the smoking and nonsmoking persons].

    PubMed

    Strauss, Ewa; Waliszewski, Krzysztof; Pawlak, Andrzej L

    2005-01-01

    In abdominal aortic aneurysm (AAA) both the etiology and the pathogenesis are of the multifactorial character. The genetic component in the determination of this disease is proven by its familial occurrence. Smoking represents the best recognized risk factor of the AAA development. Increased concentrations of homocysteine (Hcy) in plasma are the common finding in these patients. It is assumed that the Hcy thiolactone, the most reactive metabolite of Hcy, may participate in the aortic wall destruction in AAA. The polymorphic variants of the methylenetetrahydrofolate reductase (MTHFR 677C>T and 1298A>C) influence tissue concentrations of the Hcy. Paraoxonase (PON1), the enzyme associated in plasma with the HDL fraction, as lactonase detoxicates the Hcy thiolactone. The promotor polymorphism of PON1 - 108C>T gene may determine the lower activity of this enzyme. In the case-control study of 106 patients with AAA and 97 healthy persons, the effects of selected genetic and nongenetic risk factors on development of AAA were assessed, considering the possibilities of interaction between them. It was found, that the arterial hypertension, cigarette smoking and the lower HDL fraction are independent risk factors of AAA. The arterial hypertension was a risk factor both in the smoking and the nonsmoking males, whereas the lower HDL fraction has been the risk factor only for the smoking men. By the multivariate analysis in the nonsmoking males the MTHFR 1298 AC and CC genotypes increased the risk of AAA development 4,8-fold in relation to the MTHFR 1298 AA nonsmoking males. In reference to the genotypes of the expected high impact on the metabolism of Hcy and of Hcy thiolactone, the genotypes of MTHFR 677TT and PON1 -108CT and TT were more frequent in smoking ones, but the difference was not significant. This observation fits with the assumption that the influence of smoking on the occurrence of AAA prevails over that of genetic variability. When the patients age was considered

  13. Neuroprotective role for carbonyl reductase?

    PubMed

    Maser, Edmund

    2006-02-24

    Oxidative stress is increasingly implicated in neurodegenerative disorders including Alzheimer's, Parkinson's, Huntington's, and Creutzfeld-Jakob diseases or amyotrophic lateral sclerosis. Reactive oxygen species seem to play a significant role in neuronal cell death in that they generate reactive aldehydes from membrane lipid peroxidation. Several neuronal diseases are associated with increased accumulation of abnormal protein adducts of reactive aldehydes, which mediate oxidative stress-linked pathological events, including cellular growth inhibition and apoptosis induction. Combining findings on neurodegeneration and oxidative stress in Drosophila with studies on the metabolic characteristics of the human enzyme carbonyl reductase (CR), it is clear now that CR has a potential physiological role for neuroprotection in humans. Several lines of evidence suggest that CR represents a significant pathway for the detoxification of reactive aldehydes derived from lipid peroxidation and that CR in humans is essential for neuronal cell survival and to confer protection against oxidative stress-induced brain degeneration.

  14. Prevalence of MTHFR C677T Polymorphism in North Indian Mothers Having Babies with Trisomy 21 Down Syndrome

    ERIC Educational Resources Information Center

    Kohli, Utkarsh; Arora, Sadhna; Kabra, Madhulika; Ramakrishnan, Lakshmy; Gulati, Sheffali; Pandey, Ravindra

    2008-01-01

    Recent studies have evaluated possible links between polymorphisms in maternal folate metabolism genes and Down syndrome. Some of these studies show a significantly increased prevalence of the C677T polymorphism of the 5,10-methylene tetrahydrofolate reductase (NADPH) gene (MTHFR) among mothers who have had babies with Down syndrome. This study…

  15. Population- and Family-Based Studies Associate the "MTHFR" Gene with Idiopathic Autism in Simplex Families

    ERIC Educational Resources Information Center

    Liu, Xudong; Solehdin, Fatima; Cohen, Ira L.; Gonzalez, Maripaz G.; Jenkins, Edmund C.; Lewis, M. E. Suzanne; Holden, Jeanette J. A.

    2011-01-01

    Two methylenetetrahydrofolate reductase gene ("MTHFR") functional polymorphisms were studied in 205 North American simplex (SPX) and 307 multiplex (MPX) families having one or more children with an autism spectrum disorder. Case-control comparisons revealed a significantly higher frequency of the low-activity 677T allele, higher prevalence of the…

  16. Genetics Home Reference: 5-alpha reductase deficiency

    MedlinePlus

    ... About half of these individuals adopt a male gender role in adolescence or early adulthood. Related Information ... 1730-5. Citation on PubMed Cohen-Kettenis PT. Gender change in 46,XY persons with 5alpha-reductase- ...

  17. A dissimilatory nitrite reductase in Paracoccus halodenitrificans

    NASA Technical Reports Server (NTRS)

    Grant, M. A.; Hochstein, L. I.

    1984-01-01

    Paracoccus halodenitrificans produced a membrane-associated nitrite reductase. Spectrophotometric analysis showed it to be associated with a cd-cytochrome and located on the inner side of the cytoplasmic membrane. When supplied with nitrite, membrane preparations produced nitrous oxide and nitric oxide in different ratios depending on the electron donor employed. The nitrite reductase was maximally active at relatively low concentrations of sodium chloride and remained attached to the membranes at 100 mM sodium chloride.

  18. Characterization of thyroidal glutathione reductase

    SciTech Connect

    Raasch, R.J.

    1989-01-01

    Glutathione levels were determined in bovine and rat thyroid tissue by enzymatic conjugation with 1-chloro-2,4-dinitrobenzene using glutathione S-transferase. Bovine thyroid tissue contained 1.31 {+-} 0.04 mM reduced glutathione (GSH) and 0.14 {+-} 0.02 mM oxidized glutathione (GSSG). In the rat, the concentration of GSH was 2.50 {+-} 0.05 mM while GSSG was 0.21 {+-} 0.03 mM. Glutathione reductase (GR) was purified from bovine thyroid to electrophoretic homogeneity by ion exchange, affinity and molecular exclusion chromatography. A molecular weight range of 102-109 kDa and subunit size of 55 kDa were determined for GR. Thyroidal GR was shown to be a favoprotein with one FAD per subunit. The Michaelis constants of bovine thyroidal GR were determined to be 21.8 {mu}M for NADPH and 58.8 {mu}M for GSSG. The effect of thyroid stimulating hormone (TSH) and thyroxine (T{sub 4}) on in vivo levels of GR and glucose 6-phosphate dehydrogenase were determined in rat thyroid homogenates. Both enzymes were stimulated by TSH treatment and markedly reduced following T{sub 4} treatment. Lysosomal hydrolysis of ({sup 125}I)-labeled and unlabeled thyroglobulin was examined using size exclusion HPLC.

  19. The aldo-keto reductase superfamily homepage.

    PubMed

    Hyndman, David; Bauman, David R; Heredia, Vladi V; Penning, Trevor M

    2003-02-01

    The aldo-keto reductases (AKRs) are one of the three enzyme superfamilies that perform oxidoreduction on a wide variety of natural and foreign substrates. A systematic nomenclature for the AKR superfamily was adopted in 1996 and was updated in September 2000 (visit www.med.upenn.edu/akr). Investigators have been diligent in submitting sequences of functional proteins to the Web site. With the new additions, the superfamily contains 114 proteins expressed in prokaryotes and eukaryotes that are distributed over 14 families (AKR1-AKR14). The AKR1 family contains the aldose reductases, the aldehyde reductases, the hydroxysteroid dehydrogenases and steroid 5beta-reductases, and is the largest. Other families of interest include AKR6, which includes potassium channel beta-subunits, and AKR7 the aflatoxin aldehyde reductases. Two new families include AKR13 (yeast aldose reductase) and AKR14 (Escherichia coli aldehyde reductase). Crystal structures of many AKRs and their complexes with ligands are available in the PDB and accessible through the Web site. Each structure has the characteristic (alpha/beta)(8)-barrel motif of the superfamily, a conserved cofactor binding site and a catalytic tetrad, and variable loop structures that define substrate specificity. Although the majority of AKRs are monomeric proteins of about 320 amino acids in length, the AKR2, AKR6 and AKR7 family may form multimers. To expand the nomenclature to accommodate multimers, we recommend that the composition and stoichiometry be listed. For example, AKR7A1:AKR7A4 (1:3) would designate a tetramer of the composition indicated. The current nomenclature is recognized by the Human Genome Project (HUGO) and the Web site provides a link to genomic information including chromosomal localization, gene boundaries, human ESTs and SNPs and much more.

  20. Chicken muscle aldose reductase: purification, properties and relationship to other chicken aldo/keto reductases.

    PubMed

    Murphy, D G; Davidson, W S

    1986-01-01

    An enzyme that catalyzes the NADPH-dependent reduction of a wide range of aromatic and hydroxy-aliphatic aldehydes was purified from chicken breast muscle. This enzyme shares many properties with mammalian aldose reductases including molecular weight, relative substrate specificity, Michaelis constants, an inhibitor specificity. Therefore, it seems appropriate to call this enzyme an aldose reductase (EC 1.1.1.21). Chicken muscle aldose reductase appears to be kinetically identical to an aldose reductase that has been purified from chicken kidney (Hara et al., Eur. J. Biochem. 133, 207-214) and to hen muscle L-glycol dehydrogenase (Bernado et al., Biochim. biophys. Acta 659, 189-198). The association of this aldose reductase with muscular dystrophy in the chick is discussed.

  1. Respiratory arsenate reductase as a bidirectional enzyme

    USGS Publications Warehouse

    Richey, C.; Chovanec, P.; Hoeft, S.E.; Oremland, R.S.; Basu, P.; Stolz, J.F.

    2009-01-01

    The haloalkaliphilic bacterium Alkalilimnicola ehrlichii is capable of anaerobic chemolithoautotrophic growth by coupling the oxidation of arsenite (As(III)) to the reduction of nitrate and carbon dioxide. Analysis of its complete genome indicates that it lacks a conventional arsenite oxidase (Aox), but instead possesses two operons that each encode a putative respiratory arsenate reductase (Arr). Here we show that one homolog is expressed under chemolithoautotrophic conditions and exhibits both arsenite oxidase and arsenate reductase activity. We also demonstrate that Arr from two arsenate respiring bacteria, Alkaliphilus oremlandii and Shewanella sp. strain ANA-3, is also biochemically reversible. Thus Arr can function as a reductase or oxidase. Its physiological role in a specific organism, however, may depend on the electron potentials of the molybdenum center and [Fe–S] clusters, additional subunits, or constitution of the electron transfer chain. This versatility further underscores the ubiquity and antiquity of microbial arsenic metabolism.

  2. Diversity in mechanisms of substrate oxidation by cytochrome P450 2D6. Lack of an allosteric role of NADPH-cytochrome P450 reductase in catalytic regioselectivity.

    PubMed

    Hanna, I H; Krauser, J A; Cai, H; Kim, M S; Guengerich, F P

    2001-10-26

    Cytochrome P450 (P450) 2D6 was first identified as the polymorphic human debrisoquine hydroxylase and subsequently shown to catalyze the oxidation of a variety of drugs containing a basic nitrogen. Differences in the regioselectivity of oxidation products formed in systems containing NADPH-P450 reductase/NADPH and the model oxidant cumene hydroperoxide have been proposed by others to be due to an allosteric influence of the reductase on P450 2D6 (Modi, S., Gilham, D. E., Sutcliffe, M. J., Lian, L.-Y., Primrose, W. U., Wolf, C. R., and Roberts, G. C. K. (1997) Biochemistry 36, 4461-4470). We examined the differences in the formation of oxidation products of N-methyl-4-phenyl-1,2,5,6-tetrahydropyridine, metoprolol, and bufuralol between reductase-, cumene hydroperoxide-, and iodosylbenzene-supported systems. Catalytic regioselectivity was not influenced by the presence of the reductase in any of the systems supported by model oxidants, ruling out allosteric influences. The presence of the reductase had little effect on the affinity of P450 2D6 for any of these three substrates. The addition of the reaction remnants of the model oxidants (cumyl alcohol and iodobenzene) to the reductase-supported system did not affect reaction patterns, arguing against steric influences of these products on catalytic regioselectivity. Label from H(2)18O was quantitatively incorporated into 1'-hydroxybufuralol in the iodosylbenzene- but not in the reductase- or cumene hydroperoxide-supported reactions. We conclude that the P450 systems utilizing NADPH-P450 reductase, cumene hydroperoxide, and iodosylbenzene use similar but distinct chemical mechanisms. These differences are the basis for the variable product distributions, not an allosteric influence of the reductase.

  3. The tyrosyl free radical in ribonucleotide reductase.

    PubMed Central

    Gräslund, A; Sahlin, M; Sjöberg, B M

    1985-01-01

    The enzyme, ribonucleotide reductase, catalyses the formation of deoxyribonucleotides from ribonucleotides, a reaction essential for DNA synthesis in all living cells. The Escherichia coli ribonucleotide reductase, which is the prototype of all known eukaryotic and virus-coded enzymes, consists of two nonidentical subunits, proteins B1 and B2. The B2 subunit contains an antiferromagnetically coupled pair of ferric ions and a stable tyrosyl free radical. EPR studies show that the tyrosyl radical, formed by loss of ferric ions and a stable tyrosyl free radical. EPR studies show that the tyrosyl radical, formed by loss of an electron, has its unpaired spin density delocalized in the aromatic ring of tyrosine. Effects of iron-radical interaction indicate a relatively close proximity between the iron center and the radical. The EPR signal of the radical can be studied directly in frozen packed cells of E. coli or mammalian origin, if the cells are made to overproduce ribonucleotide reductase. The hypothetic role of the tyrosyl free radical in the enzymatic reaction is not yet elucidated, except in the reaction with the inhibiting substrate analogue 2'-azido-CDP. In this case, the normal tyrosyl radical is destroyed with concomitant appearance of a 2'-azido-CDP-localized radical intermediate. Attempts at spin trapping of radical reaction intermediates have turned out negative. In E. coli the activity of ribonucleotide reductase may be regulated by enzymatic activities that interconvert a nonradical containing form and the fully active protein B2. In synchronized mammalian cells, however, the cell cycle variation of ribonucleotide reductase, studied by EPR, was shown to be due to de novo protein synthesis. Inhibitors of ribonucleotide reductase are of medical interest because of their ability to control DNA synthesis. One example is hydroxyurea, used in cancer therapy, which selectively destroys the tyrosyl free radical. PMID:3007085

  4. Prevalence of MTHFR C677T and MS A2756G polymorphisms in major depressive disorder, and their impact on response to fluoxetine treatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To examine the prevalence of the C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene and the A2756G polymorphism of methionine synthase (MS), and their impact on antidepressant response. We screened 224 subjects (52% female, mean age 39 +/- 11 years) with SCID-diagnosed major...

  5. Evaluation of nitrate reductase activity in Rhizobium japonicum

    SciTech Connect

    Streeter, J.G.; DeVine, P.J.

    1983-08-01

    Nitrate reductase activity was evaluated by four approaches, using four strains of Rhizobium japonicum and 11 chlorate-resistant mutants of the four strains. It was concluded that in vitro assays with bacteria or bacteroids provide the most simple and reliable assessment of the presence or absence of nitrate reductase. Nitrite reductase activity with methyl viologen and dithionite was found, but the enzyme activity does not confound the assay of nitrate reductase. 18 references

  6. Isolation, sequence identification and tissue expression profile of two novel soybean (glycine max) genes-vestitone reductase and chalcone reductase.

    PubMed

    Liu, G Y

    2009-09-01

    The complete mRNA sequences of two soybean (glycine max) genes-vestitone reductase and chalcone reductase, were amplified using the rapid amplification of cDNA ends methods. The sequence analysis of these two genes revealed that soybean vestitone reductase gene encodes a protein of 327 amino acids which has high homology with the vestitone reductase of Medicago sativa (77%). The soybean chalcone reductase gene encodes a protein of 314 amino acids that has high homology with the chalcone reductase of kudzu vine (88%) and medicago sativa (83%). The expression profiles of the soybean vestitone reductase and chalcone reductase genes were studied and the results indicated that these two soybean genes were differentially expressed in detected soybean tissues including leaves, stems, roots, inflorescences, embryos and endosperm. Our experiment established the foundation for further research on these two soybean genes.

  7. Post-translational Regulation of Nitrate Reductase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrate reductase (NR) catalyzes the reduction of nitrate to nitrite, which is the first step in the nitrate assimilation pathway, but can also reduce nitrite to nitric oxide (NO), an important signaling molecule that is thought to mediate a wide array of of developmental and physiological processes...

  8. Fumarate Reductase Activity of Streptococcus faecalis

    PubMed Central

    Aue, B. J.; Diebel, R. H.

    1967-01-01

    Some characteristics of a fumarate reductase from Streptococcus faecalis are described. The enzyme had a pH optimum of 7.4; optimal activity was observed when the ionic strength of the phosphate buffer was adjusted to 0.088. The Km value of the enzyme for reduced flavin mononucleotide was 2 × 10−4 m as determined with a 26-fold preparation. In addition to fumarate, the enzyme reduced maleate and mesaconate. No succinate dehydrogenase activity was detected, but succinate did act as an inhibitor of the fumarate reductase activity. Other inhibitors were malonate, citraconate, and trans-, trans-muconate. Metal-chelating agents did not inhibit the enzyme. A limited inhibition by sulfhydryl-binding agents was observed, and the preparations were sensitive to air oxidation and storage. Glycine, alanine, histidine, and possibly lysine stimulated fumarate reductase activity in the cell-free extracts. However, growth in media supplemented with glycine did not enhance fumarate reductase activity. The enzymatic activity appears to be constitutive. PMID:4960892

  9. [Pharmacogenetics and tumor sensitivity of antineoplastic agents. Application to colorectal cancer].

    PubMed

    Milano, Gérard

    2008-05-31

    There are gene polymorphisms which can impact on the pharmacodynamics of anticancer agents used in the treatment of colorectal cancer. It is the case for thymidylate synthase, for methylenetetrahydrofolate reductase and for UGT 1A1. Polymorphisms of UGT 1A1 are considered as potential indicators of a risk of toxicity treatment by irinotecan. Clinical trials are in progress so as to validate the clinical usefulness of these germinal genetic analyses so as to select treatments/doses adapted to individual profiles.

  10. Control of dihydrofolate reductase messenger ribonucleic acid production

    SciTech Connect

    Leys, E.J.; Kellems, R.E.

    1981-11-01

    The authors used methotrexate-resistant mouse cells in which dihydrofolate reductase levels are approximately 500 times normal to study the effect of growth stimulation on dihydrofolate reductase gene expression. As a result of growth stimulation, the relative rate of dihydrofolate reductase protein synthesis increased threefold, reaching a maximum between 25 and 30 h after stimulation. The relative rate of dihydrofolate reductase messenger ribonucleic acid production (i.e., the appearance of dihydrofolate reductase messenger ribonucleic acid in the cytoplasm) increased threefold after growth stimulation and was accompanied by a corresponding increase in the relative steady-state level of dihydrofolate reductase ribonucleic acid in the nucleus. However, the increase in the nuclear level of dihydrofolate reductase ribonucleic acid was not accompanied by a significant increase in the relative rate of transcription of the dihydrofolate reductase genes. These data indicated that the relative rate of appearance of dihydrofolate reductase messenger ribonucleic acid in the cytoplasm depends on the relative stability of the dihydrofolate reductase ribonucleic acid sequences in the nucleus and is not dependent on the relative rate of transcription of the dihydrofolate reductase genes.

  11. Augmentation of CFTR maturation by S-nitrosoglutathione reductase

    PubMed Central

    Sawczak, Victoria; Zaidi, Atiya; Butler, Maya; Bennett, Deric; Getsy, Paulina; Zeinomar, Maryam; Greenberg, Zivi; Forbes, Michael; Rehman, Shagufta; Jyothikumar, Vinod; DeRonde, Kim; Sattar, Abdus; Smith, Laura; Corey, Deborah; Straub, Adam; Sun, Fei; Palmer, Lisa; Periasamy, Ammasi; Randell, Scott; Kelley, Thomas J.; Lewis, Stephen J.

    2015-01-01

    S-nitrosoglutathione (GSNO) reductase regulates novel endogenous S-nitrosothiol signaling pathways, and mice deficient in GSNO reductase are protected from airways hyperreactivity. S-nitrosothiols are present in the airway, and patients with cystic fibrosis (CF) tend to have low S-nitrosothiol levels that may be attributed to upregulation of GSNO reductase activity. The present study demonstrates that 1) GSNO reductase activity is increased in the cystic fibrosis bronchial epithelial (CFBE41o−) cells expressing mutant F508del-cystic fibrosis transmembrane regulator (CFTR) compared with the wild-type CFBE41o− cells, 2) GSNO reductase expression level is increased in the primary human bronchial epithelial cells expressing mutant F508del-CFTR compared with the wild-type cells, 3) GSNO reductase colocalizes with cochaperone Hsp70/Hsp90 organizing protein (Hop; Stip1) in human airway epithelial cells, 4) GSNO reductase knockdown with siRNA increases the expression and maturation of CFTR and decreases Stip1 expression in human airway epithelial cells, 5) increased levels of GSNO reductase cause a decrease in maturation of CFTR, and 6) a GSNO reductase inhibitor effectively reverses the effects of GSNO reductase on CFTR maturation. These studies provide a novel approach to define the subcellular location of the interactions between Stip1 and GSNO reductase and the role of S-nitrosothiols in these interactions. PMID:26637637

  12. Analysis of the promoter region of the gene encoding NAD-dependent methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase.

    PubMed Central

    Bélanger, C; Peri, K G; MacKenzie, R E

    1991-01-01

    Sequence analysis of the 5'-flanking region of the gene encoding NAD-dependent methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase (NMDMC) revealed several putative cis-regulatory elements. To delineate the function of these regulatory elements, various deletion mutants of the 5'-flanking region were connected to the reporter gene chloramphenicol acetyltransferase (CAT) and promoter activity was measured in transient transfection assays. Transfection experiments performed with the sequence extending from -508 to +59 produced a high-level transient expression of the CAT gene in BALB/c 3T3-SV-T2 and NIH 3T3 cells. Removal of the sequence from +16 to +59 which includes the second transcription start point at +43, a TATA-like box and 5'-untranslated sequences abolished the promoter activity. Deletion analysis of 5'-upstream sequences revealed that the region from positions -55 to +59 is sufficient to mediate a high CAT activity comparable to the level obtained with the construct -508/+59. Within this region are found a CAAT box, a TATA-like box and two putative GC boxes. A functional analysis of the promoter showed that the sequence from -55 to +59 is sufficient to respond to stimulation by serum. Images PMID:1843253

  13. Isolation and characterization of a nitrite reductase gene and its use as a probe for denitrifying bacteria.

    PubMed Central

    Smith, G B; Tiedje, J M

    1992-01-01

    The dissimilatory nitrite reductase gene (nir) from denitrifying bacterium Pseudomonas stutzeri JM300 was isolated and sequenced. In agreement with recent sequence information from another strain of P. stutzeri (strain ZoBell), strain JM300 nir is the first gene in an operon and is followed immediately by a gene which codes for a tetraheme protein; 2.5 kb downstream from the nitrite reductase carboxyl terminus is the cytochrome c551 gene. P. stutzeri JM300 nir is 67% homologous to P. aeruginosa nir and 88% homologous to P. stutzeri ZoBell nir. Within the nitrite reductase promoter region is an fnr-like operator very similar to an operator upstream of a separate anaerobic pathway, that for arginine catabolism in P. aeruginosa. The denitrification genes in P. stutzeri thus may be under the same regulatory control as that found for other anaerobic pathways of pseudomonads. We have generated gene probes from restriction fragments within the nitrite reductase operon to evaluate their usefulness in ecology studies of denitrification. Probes generated from the carboxyl terminus region hybridized to denitrifying bacteria from five separate genera and did not cross-hybridize to any nondenitrifying bacteria among six genera tested. The denitrifier probes were successful in detecting denitrifying bacteria from samples such as a bioreactor consortium, aquifer microcosms, and denitrifying toluene-degrading enrichments. The probes also were used to reveal restriction fragment length polymorphism patterns indicating the diversity of denitrifiers present in these mixed communities. Images PMID:1539983

  14. FRUCTOSE-6-PHOSPHATE REDUCTASE FROM SALMONELLA GALLINARUM

    PubMed Central

    Zancan, Glaci T.; Bacila, Metry

    1964-01-01

    Zancan, Glaci T. (Universidade do Paraná, Curitiba, Paraná, Brazil), and Metry Bacila. Fructose-6-phosphate reductase from Salmonella gallinarum. J. Bacteriol. 87:614–618. 1964.—A fructose-6-phosphate reductase present in cell-free extracts of Salmonella gallinarum was purified approximately 42 times. The optimal pH for this enzyme is 8.0. The enzyme is specific for fructose-6-phosphate and reduced nicotinamide adenine dinucleotide (NADH). The dissociation constants are 1.78 × 10−4m for fructose-6-phosphate and 8.3 × 10−5m for NADH. The Q10, reaction order, and equilibrium constant were determined. The enzyme is sensitive to p-chloromercuribenzoic acid, but not to o-iodosobenzoic acid nor to N-ethylmaleimide. PMID:14127579

  15. Retinal Ganglion Cell Loss and Mild Vasculopathy in Methylene Tetrahydrofolate Reductase (Mthfr)-Deficient Mice: A Model of Mild Hyperhomocysteinemia

    PubMed Central

    Markand, Shanu; Saul, Alan; Roon, Penny; Prasad, Puttur; Martin, Pamela; Rozen, Rima; Ganapathy, Vadivel; Smith, Sylvia B.

    2015-01-01

    Purpose. Methylenetetrahydrofolate reductase (Mthfr) is a key enzyme in homocysteine-methionine metabolism. We investigated Mthfr expression in retina and asked whether mild hyperhomocysteinemia, due to Mthfr deficiency, alters retinal neurovascular structure and function. Methods. Expression of Mthfr was investigated at the gene and protein level using quantitative (q) RT-PCR, in situ hybridization, immunoblotting, and immunohistochemistry (IHC). The Mthfr+/+ and Mthfr+/− mice were subjected to comprehensive evaluation using ERG, funduscopy, fluorescein angiography (FA), spectral-domain optical coherence tomography (SD-OCT), HPLC, and morphometric and IHC analysis of glial fibrillary acidic protein (GFAP) at 8 to 24 weeks. Results. Gene and protein analyses disclosed widespread retinal expression of Mthfr. Electroretinography (ERG) revealed a significant decrease in positive scotopic threshold response in retinas of Mthfr+/− mice at 24 weeks. Fundus examination in mice from both groups was normal; FA revealed areas of focal vascular leakage in 20% of Mthfr+/− mice at 12 to 16 weeks and 60% by 24 weeks. The SD-OCT revealed a significant decrease in nerve fiber layer (NFL) thickness at 24 weeks in Mthfr+/− compared to Mthfr+/+ mice. There was a 2-fold elevation in retinal hcy at 24 weeks in Mthfr+/− mice by HPLC and IHC. Morphometric analysis revealed an approximately 20% reduction in cells in the ganglion cell layer of Mthfr+/− mice at 24 weeks. The IHC indicated significantly increased GFAP labeling suggestive of Müller cell activation. Conclusions. Mildly hyperhomocysteinemic Mthfr+/− mice demonstrate reduced ganglion cell function, thinner NFL, and mild vasculopathy by 24 weeks. The retinal phenotype is similar to that of hyperhomocysteinemic mice with deficiency of cystathionine-β-synthase (Cbs) reported earlier. The data support the hypothesis that hyperhomocysteinemia may be causative in certain retinal neurovasculopathies. PMID:25766590

  16. Characterization of erythrose reductases from filamentous fungi

    PubMed Central

    2013-01-01

    Proteins with putative erythrose reductase activity have been identified in the filamentous fungi Trichoderma reesei, Aspergillus niger, and Fusarium graminearum by in silico analysis. The proteins found in T. reesei and A. niger had earlier been characterized as glycerol dehydrogenase and aldehyde reductase, respectively. Corresponding genes from all three fungi were cloned, heterologously expressed in Escherichia coli, and purified. Subsequently, they were used to establish optimal enzyme assay conditions. All three enzymes strictly require NADPH as cofactor, whereas with NADH no activity could be observed. The enzymatic characterization of the three enzymes using ten substrates revealed high substrate specificity and activity with D-erythrose and D-threose. The enzymes from T. reesei and A. niger herein showed comparable activities, whereas the one from F. graminearum reached only about a tenth of it for all tested substrates. In order to proof in vivo the proposed enzyme function, we overexpressed the erythrose reductase-encoding gene in T. reesei. An increased production of erythritol by the recombinant strain compared to the parental strain could be detected. PMID:23924507

  17. A Ferredoxin Disulfide Reductase Delivers Electrons to the Methanosarcina barkeri Class III Ribonucleotide Reductase

    PubMed Central

    2015-01-01

    Two subtypes of class III anaerobic ribonucleotide reductases (RNRs) studied so far couple the reduction of ribonucleotides to the oxidation of formate, or the oxidation of NADPH via thioredoxin and thioredoxin reductase. Certain methanogenic archaea contain a phylogenetically distinct third subtype of class III RNR, with distinct active-site residues. Here we report the cloning and recombinant expression of the Methanosarcina barkeri class III RNR and show that the electrons required for ribonucleotide reduction can be delivered by a [4Fe-4S] protein ferredoxin disulfide reductase, and a conserved thioredoxin-like protein NrdH present in the RNR operon. The diversity of class III RNRs reflects the diversity of electron carriers used in anaerobic metabolism. PMID:26536144

  18. Methionine sulfoxide reductase contributes to meeting dietary methionine requirements

    PubMed Central

    Zhao, Hang; Kim, Geumsoo; Levine, Rodney L.

    2012-01-01

    Methionine sulfoxide reductases are present in all aerobic organisms. They contribute to antioxidant defenses by reducing methionine sulfoxide in proteins back to methionine. However, the actual in vivo roles of these reductases are not well defined. Since methionine is an essential amino acid in mammals, we hypothesized that methionine sulfoxide reductases may provide a portion of the dietary methionine requirement by recycling methionine sulfoxide. We used a classical bioassay, the growth of weanling mice fed diets varying in methionine, and applied it to mice genetically engineered to alter the levels of methionine sulfoxide reductase A or B1. Mice of all genotypes were growth retarded when raised on chow containing 0.10% methionine instead of the standard 0.45% methionine. Retardation was significantly greater in knockout mice lacking both reductases. We conclude that the methionine sulfoxide reductases can provide methionine for growth in mice with limited intake of methionine, such as may occur in the wild. PMID:22521563

  19. Structural Elucidation of Chalcone Reductase and Implications for Deoxychalcone Biosynthesis

    PubMed Central

    Bomati, Erin K.; Austin, Michael B.; Bowman, Marianne E.; Dixon, Richard A.; Noel, Joseph P.

    2010-01-01

    4,2′,4′,6′-tetrahydroxychalcone (chalcone) and 4,2′,4′-trihydroxychalcone (deoxychalcone) serve as precursors of ecologically important flavonoids and isoflavonoids. Deoxychalcone formation depends on chalcone synthase and chalcone reductase; however, the identity of the chalcone reductase substrate out of the possible substrates formed during the multistep reaction catalyzed by chalcone synthase remains experimentally elusive. We report here the three-dimensional structure of alfalfa chalcone reductase bound to the NADP+ cofactor and propose the identity and binding mode of its substrate, namely the non-aromatized coumaryl-trione intermediate of the chalcone synthase-catalyzed cyclization of the fully extended coumaryl-tetraketide thioester intermediate. In the absence of a ternary complex, the quality of the refined NADP+-bound chalcone reductase structure serves as a template for computer-assisted docking to evaluate the likelihood of possible substrates. Interestingly, chalcone reductase adopts the three-dimensional structure of the aldo/keto reductase superfamily. The aldo/keto reductase fold is structurally distinct from all known ketoreductases of fatty acid biosynthesis, which instead belong to the short-chain dehydrogenase/reductase superfamily. The results presented here provide structural support for convergent functional evolution of these two ketoreductases that share similar roles in the biosynthesis of fatty acids/polyketides. In addition, the chalcone reductase structure represents the first protein structure of a member of the aldo/ketoreductase 4 family. Therefore, the chalcone reductase structure serves as a template for the homology modeling of other aldo/ketoreductase 4 family members, including the reductase involved in morphine biosynthesis, namely codeinone reductase. PMID:15970585

  20. Limited proteolysis of the nitrate reductase from spinach leaves.

    PubMed

    Kubo, Y; Ogura, N; Nakagawa, H

    1988-12-25

    The functional structure of assimilatory NADH-nitrate reductase from spinach leaves was studied by limited proteolysis experiments. After incubation of purified nitrate reductase with trypsin, two stable products of 59 and 45 kDa were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The fragment of 45 kDa was purified by Blue Sepharose chromatography. NADH-ferricyanide reductase and NADH-cytochrome c reductase activities were associated with this 45-kDa fragment which contains FAD, heme, and NADH binding fragment. After incubation of purified nitrate reductase with Staphylococcus aureus V8 protease, two major peaks were observed by high performance liquid chromatography size exclusion gel filtration. FMNH2-nitrate reductase and reduced methyl viologen-nitrate reductase activities were associated with the first peak of 170 kDa which consists of two noncovalently associated (75-90-kDa) fragments. NADH-ferricyanide reductase activity, however, was associated with the second peak which consisted of FAD and NADH binding sites. Incubation of the 45-kDa fragment with S. aureus V8 protease produced two major fragments of 28 and 14 kDa which contained FAD and heme, respectively. These results indicate that the molybdenum, heme, and FAD components of spinach nitrate reductase are contained in distinct domains which are covalently linked by exposed hinge regions. The molybdenum domain appears to be important in the maintenance of subunit interactions in the enzyme complex.

  1. Enzyme toolbox: novel enantiocomplementary imine reductases.

    PubMed

    Scheller, Philipp N; Fademrecht, Silvia; Hofelzer, Sebastian; Pleiss, Jürgen; Leipold, Friedemann; Turner, Nicholas J; Nestl, Bettina M; Hauer, Bernhard

    2014-10-13

    Reducing reactions are among the most useful transformations for the generation of chiral compounds in the fine-chemical industry. Because of their exquisite selectivities, enzymatic approaches have emerged as the method of choice for the reduction of C=O and activated C=C bonds. However, stereoselective enzymatic reduction of C=N bonds is still in its infancy-it was only recently described after the discovery of enzymes capable of imine reduction. In our work, we increased the spectrum of imine-reducing enzymes by database analysis. By combining the currently available knowledge about the function of imine reductases with the experimentally uncharacterized diversity stored in protein sequence databases, three novel imine reductases with complementary enantiopreference were identified along with amino acids important for catalysis. Furthermore, their reducing capability was demonstrated by the reduction of the pharmaceutically relevant prochiral imine 2-methylpyrroline. These novel enzymes exhibited comparable to higher catalytic efficiencies than previously described enzymes, and their biosynthetic potential is highlighted by the full conversion of 2-methylpyrroline in whole cells with excellent selectivities.

  2. Soluble ascorbate free radical reductase in the human lens.

    PubMed

    Bando, M; Obazawa, H

    1994-01-01

    A major and a minor ascorbate free radical (AFR) reductase were separated from the soluble fraction in the human lens cortex by DEAE-cellulose ion-exchange column chromatography. These AFR reductases also exhibited diaphorase activity using dichlorophenolindophenol and ferricyanide as electron acceptors. The major AFR reductase was partially purified by 5'AMP-Sepharose 4B affinity column chromatography. This partially purified AFR reductase showed a single band of diaphorase activity in native polyacrylamide disc gel electrophoresis. This activity band corresponded to the major protein observed in protein staining by Coomassie Brilliant Blue. However, the protein staining by Coomassie Brilliant Blue showed this activity band surrounded by diffused staining. Molecular weight of the partially purified AFR reductase was determined to be 32 kDa by gel filtration, and the apparent Km value for AFR was about 15 microM. This major lens AFR reductase could be distinguished from soluble Neurospora, Euglena and cucumber AFR reductases, and from two ubiquitous enzymes with reduction activity of AFR and/or foreign compounds, ie, NADH-cytochrome b5 reductase and DT-diaphorase, by their molecular weights, Km values and/or ion-exchange chromatographic behaviors.

  3. Functional and Phylogenetic Divergence of Fungal Adenylate-Forming Reductases

    PubMed Central

    Kalb, Daniel; Lackner, Gerald

    2014-01-01

    A key step in fungal l-lysine biosynthesis is catalyzed by adenylate-forming l-α-aminoadipic acid reductases, organized in domains for adenylation, thiolation, and the reduction step. However, the genomes of numerous ascomycetes and basidiomycetes contain an unexpectedly large number of additional genes encoding similar but functionally distinct enzymes. Here, we describe the functional in vitro characterization of four reductases which were heterologously produced in Escherichia coli. The Ceriporiopsis subvermispora serine reductase Nps1 features a terminal ferredoxin-NADP+ reductase (FNR) domain and thus belongs to a hitherto undescribed class of fungal multidomain enzymes. The second major class is characterized by the canonical terminal short-chain dehydrogenase/reductase domain and represented by Ceriporiopsis subvermispora Nps3 as the first biochemically characterized l-α-aminoadipic acid reductase of basidiomycete origin. Aspergillus flavus l-tyrosine reductases LnaA and LnbA are members of a distinct phylogenetic clade. Phylogenetic analysis supports the view that fungal adenylate-forming reductases are more diverse than previously recognized and belong to four distinct classes. PMID:25085485

  4. Transcripts of anthocyanidin reductase and leucoanthocyanidin reductase and measurement of catechin and epicatechin in tartary buckwheat.

    PubMed

    Kim, Yeon Bok; Thwe, Aye Aye; Kim, Yeji; Li, Xiaohua; Cho, Jin Woong; Park, Phun Bum; Valan Arasu, Mariadhas; Abdullah Al-Dhabi, Naif; Kim, Sun-Ju; Suzuki, Tastsuro; Hyun Jho, Kwang; Park, Sang Un

    2014-01-01

    Anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR) play an important role in the monomeric units biosynthesis of proanthocyanidins (PAs) such as catechin and epicatechin in several plants. The aim of this study was to clone ANR and LAR genes involved in PAs biosynthesis and examine the expression of these two genes in different organs under different growth conditions in two tartary buckwheat cultivars, Hokkai T8 and T10. Gene expression was carried out by quantitative real-time RT-PCR, and catechin and epicatechin content was analyzed by high performance liquid chromatography. The expression pattern of ANR and LAR did not match the accumulation pattern of PAs in different organs of two cultivars. Epicatechin content was the highest in the flowers of both cultivars and it was affected by light in only Hokkai T8 sprouts. ANR and LAR levels in tartary buckwheat might be regulated by different mechanisms for catechin and epicatechin biosynthesis under light and dark conditions.

  5. Docking and molecular dynamics studies at trypanothione reductase and glutathione reductase active sites.

    PubMed

    Iribarne, Federico; Paulino, Margot; Aguilera, Sara; Murphy, Miguel; Tapia, Orlando

    2002-05-01

    A theoretical docking study on the active sites of trypanothione reductase (TR) and glutathione reductase (GR) with the corresponding natural substrates, trypanothione disulfide (T[S]2) and glutathione disulfide (GSSG), is reported. Molecular dynamics simulations were carried out in order to check the robustness of the docking results. The energetic results are in agreement with previous experimental findings and show the crossed complexes have lower stabilization energies than the natural ones. To test DOCK3.5, four nitro furanic compounds, previously designed as potentially active anti-chagasic molecules, were docked at the GR and TR active sites with the DOCK3.5 procedure. A good correlation was found between differential inhibitory activity and relative interaction energy (affinity). The results provide a validation test for the use of DOCK3.5 in connection with the design of anti-chagasic drugs.

  6. Transcripts of Anthocyanidin Reductase and Leucoanthocyanidin Reductase and Measurement of Catechin and Epicatechin in Tartary Buckwheat

    PubMed Central

    Kim, Yeon Bok; Thwe, Aye Aye; Kim, YeJi; Li, Xiaohua; Cho, Jin Woong; Park, Phun Bum; Valan Arasu, Mariadhas; Abdullah Al-Dhabi, Naif; Kim, Sun-Ju; Suzuki, Tastsuro; Hyun Jho, Kwang; Park, Sang Un

    2014-01-01

    Anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR) play an important role in the monomeric units biosynthesis of proanthocyanidins (PAs) such as catechin and epicatechin in several plants. The aim of this study was to clone ANR and LAR genes involved in PAs biosynthesis and examine the expression of these two genes in different organs under different growth conditions in two tartary buckwheat cultivars, Hokkai T8 and T10. Gene expression was carried out by quantitative real-time RT-PCR, and catechin and epicatechin content was analyzed by high performance liquid chromatography. The expression pattern of ANR and LAR did not match the accumulation pattern of PAs in different organs of two cultivars. Epicatechin content was the highest in the flowers of both cultivars and it was affected by light in only Hokkai T8 sprouts. ANR and LAR levels in tartary buckwheat might be regulated by different mechanisms for catechin and epicatechin biosynthesis under light and dark conditions. PMID:24605062

  7. B vitamin polymorphisms and behavior: evidence of associations with neurodevelopment, depression, schizophrenia, bipolar disorder and cognitive decline.

    PubMed

    Mitchell, E Siobhan; Conus, Nelly; Kaput, Jim

    2014-11-01

    The B vitamins folic acid, vitamin B12 and B6 are essential for neuronal function, and severe deficiencies have been linked to increased risk of neurodevelopmental disorders, psychiatric disease and dementia. Polymorphisms of genes involved in B vitamin absorption, metabolism and function, such as methylene tetrahydrofolate reductase (MTHFR), cystathionine β synthase (CβS), transcobalamin 2 receptor (TCN2) and methionine synthase reductase (MTRR), have also been linked to increased incidence of psychiatric and cognitive disorders. However, the effects of these polymorphisms are often quite small and many studies failed to show any meaningful or consistent associations. This review discusses previous findings from clinical studies and highlights gaps in knowledge. Future studies assessing B vitamin-associated polymorphisms must take into account not just traditional demographics, but subjects' overall diet, relevant biomarkers of nutritional status and also analyze related genetic factors that may exacerbate behavioral effects or nutritional status.

  8. Enhanced silver nanoparticle synthesis by optimization of nitrate reductase activity.

    PubMed

    Vaidyanathan, Ramanathan; Gopalram, Shubaash; Kalishwaralal, Kalimuthu; Deepak, Venkataraman; Pandian, Sureshbabu Ram Kumar; Gurunathan, Sangiliyandi

    2010-01-01

    Nanostructure materials are attracting a great deal of attention because of their potential for achieving specific processes and selectivity, especially in biological and pharmaceutical applications. The generation of silver nanoparticles using optimized nitrate reductase for the reduction of Ag(+) with the retention of enzymatic activity in the complex is being reported. This report involves the optimization of enzyme activity to bring about enhanced nanoparticle synthesis. Response surface methodology and central composite rotary design (CCRD) were employed to optimize a fermentation medium for the production of nitrate reductase by Bacillus licheniformis at pH 8. The four variables involved in the study of nitrate reductase were Glucose, Peptone, Yeast extract and KNO(3). Glucose had a significant effect on nitrate reductase production. The optimized medium containing (%) Glucose: 1.5, Peptone: 1, Yeast extract: 0.35 and KNO(3): 0.35 resulted in a nitrate reductase activity of 452.206 U/ml which is same as that of the central level. The medium A (showing least nitrate reductase activity) and the medium B (showing maximum nitrate reductase activity) were compared for the synthesis. Spectrophotometric analysis revealed that the particles exhibited a peak at 431 nm and the A(431) for the medium B was 2-fold greater than that of the medium A. The particles were also characterized using TEM. The particles synthesized using the optimized enzyme activity ranged from 10 to 80 nm and therefore can be extended to various medicinal applications.

  9. The structure of apo and holo forms of xylose reductase, a dimeric aldo-keto reductase from Candida tenuis.

    PubMed

    Kavanagh, Kathryn L; Klimacek, Mario; Nidetzky, Bernd; Wilson, David K

    2002-07-16

    Xylose reductase is a homodimeric oxidoreductase dependent on NADPH or NADH and belongs to the largely monomeric aldo-keto reductase superfamily of proteins. It catalyzes the first step in the assimilation of xylose, an aldose found to be a major constituent monosaccharide of renewable plant hemicellulosic material, into yeast metabolic pathways. It does this by reducing open chain xylose to xylitol, which is reoxidized to xylulose by xylitol dehydrogenase and metabolically integrated via the pentose phosphate pathway. No structure has yet been determined for a xylose reductase, a dimeric aldo-keto reductase or a family 2 aldo-keto reductase. The structures of the Candida tenuis xylose reductase apo- and holoenzyme, which crystallize in spacegroup C2 with different unit cells, have been determined to 2.2 A resolution and an R-factor of 17.9 and 20.8%, respectively. Residues responsible for mediating the novel dimeric interface include Asp-178, Arg-181, Lys-202, Phe-206, Trp-313, and Pro-319. Alignments with other superfamily members indicate that these interactions are conserved in other dimeric xylose reductases but not throughout the remainder of the oligomeric aldo-keto reductases, predicting alternate modes of oligomerization for other families. An arrangement of side chains in a catalytic triad shows that Tyr-52 has a conserved function as a general acid. The loop that folds over the NAD(P)H cosubstrate is disordered in the apo form but becomes ordered upon cosubstrate binding. A slow conformational isomerization of this loop probably accounts for the observed rate-limiting step involving release of cosubstrate. Xylose binding (K(m) = 87 mM) is mediated by interactions with a binding pocket that is more polar than a typical aldo-keto reductase. Modeling of xylose into the active site of the holoenzyme using ordered waters as a guide for sugar hydroxyls suggests a convincing mode of substrate binding.

  10. Solubilization and Resolution of the Membrane-Bound Nitrite Reductase from Paracoccus Halodenitrificans into Nitrite and Nitric Oxide Reductases

    NASA Technical Reports Server (NTRS)

    Grant, Michael A.; Cronin, Sonja E.; Hochstein, Lawrence I.

    1984-01-01

    Membranes prepared from Paracoccus halodenitrificans reduced nitrite or nitric oxide to nitrous oxide. Extraction of these membranes with the detergent CHAPSO [3-(3-Chlolamidoporopyldimethylammonio)-1-(2- hydroxy-1-propanesulfonate)], followed by ammonium sulfate fractionation of the solubilized proteins, resulted in the separation of nitrite and nitric oxide reductase activities. The fraction containing nitrite reductase activity spectrally resembled a cd-type cytochrome. Several cytochromes were detected in the nitric oxide reductase fraction. Which, if any, of these cytochromes is associated with the reduction of nitric oxide is not clear at this time.

  11. Polymorphism in Energetic Materials

    DTIC Science & Technology

    2008-01-01

    2008 NRL REVIEW 71 Polymorphism in Energetic Materials J.R. Deschamps,1 D.A. Parrish,1 and R.J. Butcher2 1Laboratory for Structure of Matter...can lead to substantial alterations in stability and performance. The authors recently reported on the crystal structures of five polymorphs of picryl...cally distinct forms. Since the properties of a solid sub- stance are determined by its composition and structure , polymorphs, although chemically

  12. Polymorphous computing fabric

    DOEpatents

    Wolinski, Christophe Czeslaw [Los Alamos, NM; Gokhale, Maya B [Los Alamos, NM; McCabe, Kevin Peter [Los Alamos, NM

    2011-01-18

    Fabric-based computing systems and methods are disclosed. A fabric-based computing system can include a polymorphous computing fabric that can be customized on a per application basis and a host processor in communication with said polymorphous computing fabric. The polymorphous computing fabric includes a cellular architecture that can be highly parameterized to enable a customized synthesis of fabric instances for a variety of enhanced application performances thereof. A global memory concept can also be included that provides the host processor random access to all variables and instructions associated with the polymorphous computing fabric.

  13. Enantioselective imine reduction catalyzed by imine reductases and artificial metalloenzymes.

    PubMed

    Gamenara, Daniela; Domínguez de María, Pablo

    2014-05-21

    Adding value to organic synthesis. Novel imine reductases enable the enantioselective reduction of imines to afford optically active amines. Likewise, novel bioinspired artificial metalloenzymes can perform the same reaction as well. Emerging proof-of-concepts are herein discussed.

  14. Exploration of Nitrate Reductase Metabolic Pathway in Corynebacterium pseudotuberculosis

    PubMed Central

    Abreu, Vinícius; Diniz, Carlos; Dorneles, Elaine M. S.; Barh, Debmalya

    2017-01-01

    Based on the ability of nitrate reductase synthesis, Corynebacterium pseudotuberculosis is classified into two biovars: Ovis and Equi. Due to the presence of nitrate reductase, the Equi biovar can survive in absence of oxygen. On the other hand, Ovis biovar that does not have nitrate reductase is able to adapt to various ecological niches and can grow on certain carbon sources. Apart from these two biovars, some other strains are also able to carry out the reduction of nitrate. The enzymes that are involved in electron transport chain are also identified by in silico methods. Findings about pathogen metabolism can contribute to the identification of relationship between nitrate reductase and the C. pseudotuberculosis pathogenicity, virulence factors, and discovery of drug targets. PMID:28316974

  15. 21 CFR 864.7375 - Glutathione reductase assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... activity of the enzyme glutathione reductase in serum, plasma, or erythrocytes by such techniques as fluorescence and photometry. The results of this assay are used in the diagnosis of liver disease,...

  16. Purification and characterization of assimilatory nitrite reductase from Candida utilis.

    PubMed

    Sengupta, S; Shaila, M S; Rao, G R

    1996-07-01

    Nitrate assimilation in many plants, algae, yeasts and bacteria is mediated by two enzymes, nitrate reductase (EC 1.6.6.2) and nitrite reductase (EC 1.7.7.1). They catalyse the stepwise reduction of nitrate to nitrite and nitrite to ammonia respectively. The nitrite reductase from an industrially important yeast, Candida utilis, has been purified to homogeneity. Purified nitrite reductase is a heterodimer and the molecular masses of the two subunits are 58 and 66 kDa. The native enzyme exhibits a molecular mass of 126 kDa as analysed by gel filtration. The identify of the two subunits of nitrite reductase was confirmed by immunoblotting using antibody for Cucurbita pepo leaf nitrite reductase. The presence of two different sized transcripts coding for the two subunits was confirmed by (a) in vitro translation of mRNA from nitrate-induced C. utilis followed by immunoprecipitation of the in vitro translated products with heterologous nitrite reductase antibody and (b) Northern-blot analysis. The 66 kDa subunit is acidic in nature which is probably due to its phosphorylated status. The enzyme is stable over a range of temperatures. Both subunits can catalyse nitrite reduction, and the reconstituted enzyme, at a higher protein concentration, shows an activity similar to that of the purified enzyme. Each of these subunits has been shown to contain a few unique peptides in addition to a large number of common peptides. Reduced Methyl Viologen has been found to be as effective an electron donor as NADPH in the catalytic process, a phenomenon not commonly seen for nitrite reductases from other systems.

  17. Comparative anatomy of the aldo-keto reductase superfamily.

    PubMed

    Jez, J M; Bennett, M J; Schlegel, B P; Lewis, M; Penning, T M

    1997-09-15

    The aldo-keto reductases metabolize a wide range of substrates and are potential drug targets. This protein superfamily includes aldose reductases, aldehyde reductases, hydroxysteroid dehydrogenases and dihydrodiol dehydrogenases. By combining multiple sequence alignments with known three-dimensional structures and the results of site-directed mutagenesis studies, we have developed a structure/function analysis of this superfamily. Our studies suggest that the (alpha/beta)8-barrel fold provides a common scaffold for an NAD(P)(H)-dependent catalytic activity, with substrate specificity determined by variation of loops on the C-terminal side of the barrel. All the aldo-keto reductases are dependent on nicotinamide cofactors for catalysis and retain a similar cofactor binding site, even among proteins with less than 30% amino acid sequence identity. Likewise, the aldo-keto reductase active site is highly conserved. However, our alignments indicate that variation ofa single residue in the active site may alter the reaction mechanism from carbonyl oxidoreduction to carbon-carbon double-bond reduction, as in the 3-oxo-5beta-steroid 4-dehydrogenases (Delta4-3-ketosteroid 5beta-reductases) of the superfamily. Comparison of the proposed substrate binding pocket suggests residues 54 and 118, near the active site, as possible discriminators between sugar and steroid substrates. In addition, sequence alignment and subsequent homology modelling of mouse liver 17beta-hydroxysteroid dehydrogenase and rat ovary 20alpha-hydroxysteroid dehydrogenase indicate that three loops on the C-terminal side of the barrel play potential roles in determining the positional and stereo-specificity of the hydroxysteroid dehydrogenases. Finally, we propose that the aldo-keto reductase superfamily may represent an example of divergent evolution from an ancestral multifunctional oxidoreductase and an example of convergent evolution to the same active-site constellation as the short

  18. Molybdenum effector of fumarate reductase repression and nitrate reductase induction in Escherichia coli.

    PubMed Central

    Iuchi, S; Lin, E C

    1987-01-01

    In Escherichia coli the presence of nitrate prevents the utilization of fumarate as an anaerobic electron acceptor. The induction of the narC operon encoding the nitrate reductase is coupled to the repression of the frd operon encoding the fumarate reductase. This coupling is mediated by nitrate as an effector and the narL product as the regulatory protein (S. Iuchi and E. C. C. Lin, Proc. Natl. Acad. Sci. USA 84:3901-3905, 1987). The protein-ligand complex appears to control narC positively but frd negatively. In the present study we found that a molybdenum coeffector acted synergistically with nitrate in the regulation of frd and narC. In chlD mutants believed to be impaired in molybdate transport (or processing), full repression of phi(frd-lac) and full induction of phi(narC-lac) by nitrate did not occur unless the growth medium was directly supplemented with molybdate (1 microM). This requirement was not clearly manifested in wild-type cells, apparently because it was met by the trace quantities of molybdate present as a contaminant in the mineral medium. In chlB mutants, which are known to accumulate the Mo cofactor because of its failure to be inserted as a prosthetic group into proteins such as nitrate reductase, nitrate repression of frd and induction of narC were also intensified by molybdate supplementation. In this case a deficiency of the molybdenum coeffector might have resulted from enhanced feedback inhibition of molybdate transport (or processing) by the elevated level of the unutilized Mo cofactor. In addition, mutations in chlE, which are known to block the synthesis of the organic moiety of the Mo cofactor, lowered the threshold concentration of nitrate (< 1 micromole) necessary for frd repression and narC induction. These changes could be explained simply by the higher intracellular nitrate attainable in cells lacking the ability to destroy the effector. PMID:3301812

  19. Distribution of Prx-linked hydroperoxide reductase activity among microorganisms.

    PubMed

    Takeda, Kouji; Nishiyama, Yoshitaka; Yoda, Koji; Watanabe, Toshihiro; Nimura-Matsune, Kaori; Mura, Kiyoshi; Tokue, Chiyoko; Katoh, Tetzuya; Kawasaki, Shinji; Niimura, Youichi

    2004-01-01

    Peroxiredoxin (Prx) constitutes a large family of enzymes found in microorganisms, animals, and plants, but the detection of the activities of Prx-linked hydroperoxide reductases (peroxiredoxin reductases) in cell extracts, and the purification based on peroxide reductase activity, have only been done in bacteria and Trypanosomatidae. A peroxiredoxin reductase (NADH oxidase) from a bacterium, Amphibacillus, displayed only poor activities in the presence of purified Prx from Saccharomyces or Synechocystis, while it is highly active in the presence of bacterial Prx. These results suggested that an enzyme system different from that in bacteria might exist for the reduction of Prx in yeast and cyanobacteria. Prx-linked hydroperoxide reductase activities were detected in cell extracts of Saccharomyces, Synechocystis, and Chlorella, and the enzyme activities of Saccharomyces and Chlorella were induced under vigorously aerated culture conditions and intensive light exposure conditions, respectively. Partial purification of Prx-linked peroxidase from the induced yeast cells indicated that the Prx-linked peroxidase system consists of two protein components, namely, thioredoxin and thioredoxin reductase. This finding is consistent with the previous report on its purification based on its protein protection activity against oxidation [Chae et al., J. Biol. Chem., 269, 27670-27678 (1994)]. In this study we have confirmed that Prx-linked peroxidase activity are widely distributed, not only in bacteria species and Trypanosomatidae, but also in yeast and photosynthetic microorganisms, and showed reconstitution of the activity from partially purified interspecies components.

  20. Microsecond subdomain folding in dihydrofolate reductase.

    PubMed

    Arai, Munehito; Iwakura, Masahiro; Matthews, C Robert; Bilsel, Osman

    2011-07-08

    The characterization of microsecond dynamics in the folding of multisubdomain proteins has been a major challenge in understanding their often complex folding mechanisms. Using a continuous-flow mixing device coupled with fluorescence lifetime detection, we report the microsecond folding dynamics of dihydrofolate reductase (DHFR), a two-subdomain α/β/α sandwich protein known to begin folding in this time range. The global dimensions of early intermediates were monitored by Förster resonance energy transfer, and the dynamic properties of the local Trp environments were monitored by fluorescence lifetime detection. We found that substantial collapse occurs in both the locally connected adenosine binding subdomain and the discontinuous loop subdomain within 35 μs of initiation of folding from the urea unfolded state. During the fastest observable ∼550 μs phase, the discontinuous loop subdomain further contracts, concomitant with the burial of Trp residue(s), as both subdomains achieve a similar degree of compactness. Taken together with previous studies in the millisecond time range, a hierarchical assembly of DHFR--in which each subdomain independently folds, subsequently docks, and then anneals into the native conformation after an initial heterogeneous global collapse--emerges. The progressive acquisition of structure, beginning with a continuously connected subdomain and spreading to distal regions, shows that chain entropy is a significant organizing principle in the folding of multisubdomain proteins and single-domain proteins. Subdomain folding also provides a rationale for the complex kinetics often observed.

  1. Active sites of thioredoxin reductases: why selenoproteins?

    PubMed

    Gromer, Stephan; Johansson, Linda; Bauer, Holger; Arscott, L David; Rauch, Susanne; Ballou, David P; Williams, Charles H; Schirmer, R Heiner; Arnér, Elias S J

    2003-10-28

    Selenium, an essential trace element for mammals, is incorporated into a selected class of selenoproteins as selenocysteine. All known isoenzymes of mammalian thioredoxin (Trx) reductases (TrxRs) employ selenium in the C-terminal redox center -Gly-Cys-Sec-Gly-COOH for reduction of Trx and other substrates, whereas the corresponding sequence in Drosophila melanogaster TrxR is -Ser-Cys-Cys-Ser-COOH. Surprisingly, the catalytic competence of these orthologous enzymes is similar, whereas direct Sec-to-Cys substitution of mammalian TrxR, or other selenoenzymes, yields almost inactive enzyme. TrxRs are therefore ideal for studying the biology of selenocysteine by comparative enzymology. Here we show that the serine residues flanking the C-terminal Cys residues of Drosophila TrxRs are responsible for activating the cysteines to match the catalytic efficiency of a selenocysteine-cysteine pair as in mammalian TrxR, obviating the need for selenium. This finding suggests that the occurrence of selenoenzymes, which implies that the organism is selenium-dependent, is not necessarily associated with improved enzyme efficiency. Our data suggest that the selective advantage of selenoenzymes is a broader range of substrates and a broader range of microenvironmental conditions in which enzyme activity is possible.

  2. Polymorphism and solvatomorphism 2008.

    PubMed

    Brittain, Harry G

    2010-09-01

    Papers and patents that deal with polymorphism and solvatomorphism have been summarized in an annual review. The review is divided into sections that cover articles of general interest, computational and theoretical studies, preparative and isolation methods, structural characterization and properties of polymorphic and solvatomorphic systems, studies of phase transformations, effects associated with secondary processing, and United States patents issued during 2008.

  3. Sulfite reductase protects plants against sulfite toxicity.

    PubMed

    Yarmolinsky, Dmitry; Brychkova, Galina; Fluhr, Robert; Sagi, Moshe

    2013-02-01

    Plant sulfite reductase (SiR; Enzyme Commission 1.8.7.1) catalyzes the reduction of sulfite to sulfide in the reductive sulfate assimilation pathway. Comparison of SiR expression in tomato (Solanum lycopersicum 'Rheinlands Ruhm') and Arabidopsis (Arabidopsis thaliana) plants revealed that SiR is expressed in a different tissue-dependent manner that likely reflects dissimilarity in sulfur metabolism between the plant species. Using Arabidopsis and tomato SiR mutants with modified SiR expression, we show here that resistance to ectopically applied sulfur dioxide/sulfite is a function of SiR expression levels and that plants with reduced SiR expression exhibit higher sensitivity than the wild type, as manifested in pronounced leaf necrosis and chlorophyll bleaching. The sulfite-sensitive mutants accumulate applied sulfite and show a decline in glutathione levels. In contrast, mutants that overexpress SiR are more tolerant to sulfite toxicity, exhibiting little or no damage. Resistance to high sulfite application is manifested by fast sulfite disappearance and an increase in glutathione levels. The notion that SiR plays a role in the protection of plants against sulfite is supported by the rapid up-regulation of SiR transcript and activity within 30 min of sulfite injection into Arabidopsis and tomato leaves. Peroxisomal sulfite oxidase transcripts and activity levels are likewise promoted by sulfite application as compared with water injection controls. These results indicate that, in addition to participating in the sulfate assimilation reductive pathway, SiR also plays a role in protecting leaves against the toxicity of sulfite accumulation.

  4. Uterine glutathione reductase activity: modulation by estrogens and progesterone.

    PubMed

    Díaz-Flores, M; Baiza-Gutman, L A; Pedrón, N N; Hicks, J J

    1999-10-29

    The aim of this study was to determine whether glutathione reductase activity in uterine tissue is regulated by sex hormones. In spayed rats uterine glutathione reductase was significantly increased by exogenous estrogen (P< 0.01), progesterone (P< 0.01) or estrogen plus progesterone (P<0.01). When enzyme activity is expressed per mg protein, daily administration of estrogen or progesterone induces a progressive increase of this enzyme between 24 to 48 h or 24 to 72 h of treatment, respectively. Whereas the combination of both steroids causes an earlier and higher increase in glutathione reductase activity at 24 h of treatment. Estradiol singly or in combination with progesterone induced the highest protein concentration in the uterus. Whereas uterine DNA concentration is only significantly affected by estradiol. Our results suggest that uterine glutathione reductase is regulated by estradiol and progesterone and may be involved in maintaining levels of reduced glutathione in the uterus. This compound may be required for control of the redox state of thiol groups and in detoxification reactions involving H2O2 and electrophylic substances. The antioxidant action of estrogens is partially due to the stimulation of glutathione reductase.

  5. HMG-CoA reductase guides migrating primordial germ cells.

    PubMed

    Van Doren, M; Broihier, H T; Moore, L A; Lehmann, R

    1998-12-03

    The enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase is best known for catalysing a rate-limiting step in cholesterol biosynthesis, but it also participates in the production of a wide variety of other compounds. Some clinical benefits attributed to inhibitors of HMG-CoA reductase are now thought to be independent of any serum cholesterol-lowering effect. Here we describe a new cholesterol-independent role for HMG-CoA reductase, in regulating a developmental process: primordial germ cell migration. We show that in Drosophila this enzyme is highly expressed in the somatic gonad and that it is necessary for primordial germ cells to migrate to this tissue. Misexpression of HMG-CoA reductase is sufficient to attract primordial germ cells to tissues other than the gonadal mesoderm. We conclude that the regulated expression of HMG-CoA reductase has a critical developmental function in providing spatial information to guide migrating primordial germ cells.

  6. Bacterial morphinone reductase is related to Old Yellow Enzyme.

    PubMed Central

    French, C E; Bruce, N C

    1995-01-01

    Morphinone reductase, produced by Pseudomonas putida M10, catalyses the NADH-dependent saturation of the carbon-carbon double bond of morphinone and codeinone, and is believed to be involved in the metabolism of morphine and codeine. The structural gene encoding morphinone reductase, designated morB, was cloned from Ps. putida M10 genomic DNA by the use of degenerate oligonucleotide probes based on elements of the amino acid sequence of the purified enzyme. Sequence analysis and structural characteristics indicated that morphinone reductase is related to the flavoprotein alpha/beta-barrel oxidoreductases, and is particularly similar to Old Yellow Enzyme of Saccharomyces spp. and the related oestrogen-binding protein of Candida albicans. Expressed sequence tags from several plant species show high homology to these enzymes, suggesting the presence of a family of enzymes conserved in plants and fungi. Although related bacterial proteins are known, morphinone reductase appears to be more similar to the eukaryotic proteins. Morphinone reductase was overexpressed in Escherichia coli, and has potential applications for the industrial preparation of semisynthetic opiates. Images Figure 1 Figure 5 PMID:8554504

  7. Purification and properties of proline reductase from Clostridium sticklandii.

    PubMed

    Seto, B; Stadtman, T C

    1976-04-25

    Proline reductase of Clostridium sticklandii is a membrane-bound protein and is released by treatment with detergents. The enzyme has been purified to homogeneity and is estimated by gel filtration and sedimentation equilibrium centrifugation to have a molecular weight of 298,000 to 327,000. A minimum molecular weight of 30,000 to 31,000 was calculated on the basis of sodium dodecyl sulfate-acrylamide gel electrophoresis and amino acid composition. Amino acid analysis showed a preponderance of acidic amino acids. No tryptophan was detected in the protein either spectrophotometrically or by amino acid analysis. A total of 20 sulfhydryl groups measured by titration of the reduced protein with 5,5'-dithiobis(2-nitrobenzoic acid) is in agreement with 20 cystic acid residues determined in hydrolysates of performic acid-oxidized protein. No molybdenum, iron, or selenium was found in the pure protein. Although NADH is the physiological electron donor for the proline reductase complex, the purified 300,000 molecular weight reductase component is inactive in the presence of NADH in vitro. Dithiothreitol, in contrast, can serve as electron donor both for unpurified (putative proline reductase complex) and purified proline reductase in vitro.

  8. Potential use of aldose reductase inhibitors to prevent diabetic complications.

    PubMed

    Zenon, G J; Abobo, C V; Carter, B L; Ball, D W

    1990-06-01

    Reviewed are (1) the biochemical basis and pathophysiology of diabetic complications and (2) the structure-activity relationships, pharmacology, pharmacokinetics, clinical trials, and adverse effects of aldose reductase inhibitors (ARIs). ARIs are a new class of drugs potentially useful in preventing diabetic complications, the most widely studied of which have been cataracts and neuropathy. ARIs inhibit aldose reductase, the first, rate-limiting enzyme in the polyol metabolic pathway. In nonphysiological hyperglycemia the activity of hexokinase becomes saturated while that of aldose reductase is enhanced, resulting in intracellular accumulation of sorbitol. Because sorbitol does not readily penetrate the cell membrane it can persist within cells, which may lead to diabetic complications. ARIs are a class of structurally dissimilar compounds that include carboxylic acid derivatives, flavonoids, and spirohydantoins. The major pharmacologic action of an ARI involves competitive binding to aldose reductase and consequent blocking of sorbitol production. ARIs delay cataract formation in animals, but the role of aldose reductase in cataract formation in human diabetics has not been established. The adverse effects of ARIs include hypersensitivity reactions. Although the polyol pathway may not be solely responsible for diabetic complications, studies suggest that therapy with ARIs could be beneficial. Further research is needed to determine the long-term impact and adverse effects of ARIs in the treatment of diabetic complications.

  9. Sulfur Isotope Effects of Dissimilatory Sulfite Reductase

    PubMed Central

    Leavitt, William D.; Bradley, Alexander S.; Santos, André A.; Pereira, Inês A. C.; Johnston, David T.

    2015-01-01

    The precise interpretation of environmental sulfur isotope records requires a quantitative understanding of the biochemical controls on sulfur isotope fractionation by the principle isotope-fractionating process within the S cycle, microbial sulfate reduction (MSR). Here we provide the only direct observation of the major (34S/32S) and minor (33S/32S, 36S/32S) sulfur isotope fractionations imparted by a central enzyme in the energy metabolism of sulfate reducers, dissimilatory sulfite reductase (DsrAB). Results from in vitro sulfite reduction experiments allow us to calculate the in vitro DsrAB isotope effect in 34S/32S (hereafter, 34εDsrAB) to be 15.3 ± 2‰, 2σ. The accompanying minor isotope effect in 33S, described as 33λDsrAB, is calculated to be 0.5150 ± 0.0012, 2σ. These observations facilitate a rigorous evaluation of the isotopic fractionation associated with the dissimilatory MSR pathway, as well as of the environmental variables that govern the overall magnitude of fractionation by natural communities of sulfate reducers. The isotope effect induced by DsrAB upon sulfite reduction is a factor of 0.3–0.6 times prior indirect estimates, which have ranged from 25 to 53‰ in 34εDsrAB. The minor isotope fractionation observed from DsrAB is consistent with a kinetic or equilibrium effect. Our in vitro constraints on the magnitude of 34εDsrAB is similar to the median value of experimental observations compiled from all known published work, where 34εr−p = 16.1‰ (r–p indicates reactant vs. product, n = 648). This value closely matches those of MSR operating at high sulfate reduction rates in both laboratory chemostat experiments (34εSO4−H2S =  17.3 ± 1.5‰, 2σ) and in modern marine sediments (34εSO4−H2S =  17.3 ± 3.8‰). Targeting the direct isotopic consequences of a specific enzymatic processes is a fundamental step toward a biochemical foundation for reinterpreting the biogeochemical and geobiological sulfur isotope records in

  10. Sulfur Isotope Effects of Dissimilatory Sulfite Reductase.

    PubMed

    Leavitt, William D; Bradley, Alexander S; Santos, André A; Pereira, Inês A C; Johnston, David T

    2015-01-01

    The precise interpretation of environmental sulfur isotope records requires a quantitative understanding of the biochemical controls on sulfur isotope fractionation by the principle isotope-fractionating process within the S cycle, microbial sulfate reduction (MSR). Here we provide the only direct observation of the major ((34)S/(32)S) and minor ((33)S/(32)S, (36)S/(32)S) sulfur isotope fractionations imparted by a central enzyme in the energy metabolism of sulfate reducers, dissimilatory sulfite reductase (DsrAB). Results from in vitro sulfite reduction experiments allow us to calculate the in vitro DsrAB isotope effect in (34)S/(32)S (hereafter, [Formula: see text]) to be 15.3 ± 2‰, 2σ. The accompanying minor isotope effect in (33)S, described as [Formula: see text], is calculated to be 0.5150 ± 0.0012, 2σ. These observations facilitate a rigorous evaluation of the isotopic fractionation associated with the dissimilatory MSR pathway, as well as of the environmental variables that govern the overall magnitude of fractionation by natural communities of sulfate reducers. The isotope effect induced by DsrAB upon sulfite reduction is a factor of 0.3-0.6 times prior indirect estimates, which have ranged from 25 to 53‰ in (34)εDsrAB. The minor isotope fractionation observed from DsrAB is consistent with a kinetic or equilibrium effect. Our in vitro constraints on the magnitude of [Formula: see text] is similar to the median value of experimental observations compiled from all known published work, where (34)ε r-p = 16.1‰ (r-p indicates reactant vs. product, n = 648). This value closely matches those of MSR operating at high sulfate reduction rates in both laboratory chemostat experiments ([Formula: see text] 17.3 ± 1.5‰, 2σ) and in modern marine sediments ([Formula: see text] 17.3 ± 3.8‰). Targeting the direct isotopic consequences of a specific enzymatic processes is a fundamental step toward a biochemical foundation for reinterpreting the

  11. Selenium in thioredoxin reductase: a mechanistic perspective.

    PubMed

    Lacey, Brian M; Eckenroth, Brian E; Flemer, Stevenson; Hondal, Robert J

    2008-12-02

    Most high M(r) thioredoxin reductases (TRs) have the unusual feature of utilizing a vicinal disulfide bond (Cys(1)-Cys(2)) which forms an eight-membered ring during the catalytic cycle. Many eukaryotic TRs have replaced the Cys(2) position of the dyad with the rare amino acid selenocysteine (Sec). Here we demonstrate that Cys- and Sec-containing TRs are distinguished by the importance each class of enzymes places on the eight-membered ring structure in the catalytic cycle. This hypothesis was explored by studying the truncated enzyme missing the C-terminal ring structure in conjunction with oxidized peptide substrates to investigate the reduction and opening of this dyad. The peptide substrates were identical in sequence to the missing part of the enzyme, containing either a disulfide or selenylsulfide linkage, but were differentiated by the presence (cyclic) and absence (acyclic) of the ring structure. The ratio of these turnover rates informs that the ring is only of modest importance for the truncated mouse mitochondrial Sec-TR (ring/no ring = 32), while the ring structure is highly important for the truncated Cys-TRs from Drosophila melanogaster and Caenorhabditis elegans (ring/no ring > 1000). All three enzymes exhibit a similar dependence upon leaving group pK(a) as shown by the use of the acyclic peptides as substrates. These two factors can be reconciled for Cys-TRs if the ring functions to simultaneously allow for attack by a nearby thiolate while correctly positioning the leaving group sulfur atom to accept a proton from the enzymic general acid. For Sec-TRs the ring is unimportant because the lower pK(a) of the selenol relative to a thiol obviates its need to be protonated upon S-Se bond scission and permits physical separation of the selenol and the general acid. Further study of the biochemical properties of the truncated Cys and Sec TR enzymes demonstrates that the chemical advantage conferred on the eukaryotic enzyme by a selenol is the ability to

  12. Association between MTHFD1 G1958A Polymorphism and Neural Tube Defects Susceptibility: A Meta-Analysis

    PubMed Central

    Jiang, Jianxin; Zhang, Yanfei; Wei, Liang; Sun, Zhiyang; Liu, Zhongmin

    2014-01-01

    Objectives The methylenetetrahydrofolate dehydrogenase (MTHFD1) gene, as one of the key genes involved in the folate pathway, has been reported to play a critical role in the pathogenesis of neural tube defects (NTDs). However, the results of published studies are contradictory and inconclusive. Thus, this meta-analysis aimed to evaluate the effect of the common polymorphism in the MTHFD1 gene, the G1958A (R653Q, dbSNP ID: rs2236225) variant, on the risk of NTDs in all eligible studies. Methods Relevant literature published before January 3, 2014 was retrieved from the MEDLINE, EMBASE, Cochrane Library, and CBM databases. Pooled crude odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated to evaluate the association between the MTHFD1 G1958A polymorphism and NTDs risk. Results We performed a meta-analysis of nine studies with a total of 4,302 NTDs patients and 4,238 healthy controls. Our results demonstrated a significant correlation between the MTHFD1 G1958A polymorphism and NTDs in an overall meta-analysis. For family-based studies, the study subjects were classified as NTD cases, mothers with NTDs offspring, and fathers with NTDs offspring. We found no association between any of the fathers’ genotypes and NTDs, whereas there was a clear excess of the 1958A allele in the mothers of children with NTDs compared with controls individuals. Conclusions In summary, our meta-analysis strongly suggests that the MTHFD1 G1958A polymorphism might be associated with maternal risk for NTDs in Caucasian populations. However, the evidence of this association should be interpreted with caution due to the selective nature of publication of genetic association studies. PMID:24977710

  13. Altered heme catabolism by heme oxygenase-1 caused by mutations in human NADPH cytochrome P450 reductase

    SciTech Connect

    Pandey, Amit V.; Flueck, Christa E.; Mullis, Primus E.

    2010-09-24

    Research highlights: {yields} Mutations in POR identified from patients lead to reduced HO-1 activities. {yields} POR mutation Y181D affecting FMN binding results in total loss of HO-1 activity. {yields} POR mutations A287P, C569Y and V608F, lost 50-70% activity. {yields} Mutations in FAD binding domain, R457H, Y459H and V492E lost all HO-1 activity. {yields} POR polymorphisms P228L, R316W, G413S, A503V and G504R have normal activity. -- Abstract: Human heme oxygenase-1 (HO-1) carries out heme catabolism supported by electrons supplied from the NADPH through NADPH P450 reductase (POR, CPR). Previously we have shown that mutations in human POR cause a rare form of congenital adrenal hyperplasia. In this study, we have evaluated the effects of mutations in POR on HO-1 activity. We used purified preparations of wild type and mutant human POR and in vitro reconstitution with purified HO-1 to measure heme degradation in a coupled assay using biliverdin reductase. Here we show that mutations in POR found in patients may reduce HO-1 activity, potentially influencing heme catabolism in individuals carrying mutant POR alleles. POR mutants Y181D, A457H, Y459H, V492E and R616X had total loss of HO-1 activity, while POR mutations A287P, C569Y and V608F lost 50-70% activity. The POR variants P228L, R316W and G413S, A503V and G504R identified as polymorphs had close to WT activity. Loss of HO-1 activity may result in increased oxidative neurotoxicity, anemia, growth retardation and iron deposition. Further examination of patients affected with POR deficiency will be required to assess the metabolic effects of reduced HO-1 activity in affected individuals.

  14. Structural functionality, catalytic mechanism modeling and molecular allergenicity of phenylcoumaran benzylic ether reductase, an olive pollen (Ole e 12) allergen

    NASA Astrophysics Data System (ADS)

    Jimenez-Lopez, Jose C.; Kotchoni, Simeon O.; Hernandez-Soriano, Maria C.; Gachomo, Emma W.; Alché, Juan D.

    2013-10-01

    Isoflavone reductase-like proteins (IRLs) are enzymes with key roles in the metabolism of diverse flavonoids. Last identified olive pollen allergen (Ole e 12) is an IRL relevant for allergy amelioration, since it exhibits high prevalence among atopic patients. The goals of this study are the characterization of (A) the structural-functionality of Ole e 12 with a focus in its catalytic mechanism, and (B) its molecular allergenicity by extensive analysis using different molecular computer-aided approaches covering (1) physicochemical properties and functional-regulatory motifs, (2) sequence analysis, 2-D and 3D structural homology modeling comparative study and molecular docking, (3) conservational and evolutionary analysis, (4) catalytic mechanism modeling, and (5) sequence, structure-docking based B-cell epitopes prediction, while T-cell epitopes were predicted by inhibitory concentration and binding score methods. Structural-based detailed features, phylogenetic and sequences analysis have identified Ole e 12 as phenylcoumaran benzylic ether reductase. A catalytic mechanism has been proposed for Ole e 12 which display Lys133 as one of the conserved residues of the IRLs catalytic tetrad (Asn-Ser-Tyr-Lys). Structure characterization revealed a conserved protein folding among plants IRLs. However, sequence polymorphism significantly affected residues involved in the catalytic pocket structure and environment (cofactor and substrate interaction-recognition). It might also be responsible for IRLs isoforms functionality and regulation, since micro-heterogeneities affected physicochemical and posttranslational motifs. This polymorphism might have large implications for molecular differences in B- and T-cells epitopes of Ole e 12, and its identification may help designing strategies to improve the component-resolving diagnosis and immunotherapy of pollen and food allergy through development of molecular tools.

  15. A detoxifying oxygen reductase in the anaerobic protozoan Entamoeba histolytica.

    PubMed

    Vicente, João B; Tran, Vy; Pinto, Liliana; Teixeira, Miguel; Singh, Upinder

    2012-09-01

    We report the characterization of a bacterial-type oxygen reductase abundant in the cytoplasm of the anaerobic protozoan parasite Entamoeba histolytica. Upon host infection, E. histolytica is confronted with various oxygen tensions in the host intestine, as well as increased reactive oxygen and nitrogen species at the site of local tissue inflammation. Resistance to oxygen-derived stress thus plays an important role in the pathogenic potential of E. histolytica. The genome of E. histolytica has four genes that encode flavodiiron proteins, which are bacterial-type oxygen or nitric oxide reductases and were likely acquired by lateral gene transfer from prokaryotes. The EhFdp1 gene has higher expression in virulent than in nonvirulent Entamoeba strains and species, hinting that the response to oxidative stress may be one correlate of virulence potential. We demonstrate that EhFdp1 is abundantly expressed in the cytoplasm of E. histolytica and that the protein levels are markedly increased (up to ~5-fold) upon oxygen exposure. Additionally, we produced fully functional recombinant EhFdp1 and demonstrated that this enzyme is a specific and robust oxygen reductase but has poor nitric oxide reductase activity. This observation represents a new mechanism of oxygen resistance in the anaerobic protozoan pathogen E. histolytica.

  16. 21 CFR 864.7375 - Glutathione reductase assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Glutathione reductase assay. 864.7375 Section 864.7375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7375...

  17. Thioredoxin and NADP-thioredoxin reductase from cultured carrot cells

    NASA Technical Reports Server (NTRS)

    Johnson, T. C.; Cao, R. Q.; Kung, J. E.; Buchanan, B. B.

    1987-01-01

    Dark-grown carrot (Daucus carota L.) tissue cultures were found to contain both protein components of the NADP/thioredoxin system--NADP-thioredoxin reductase and the thioredoxin characteristic of heterotrophic systems, thioredoxin h. Thioredoxin h was purified to apparent homogeneity and, like typical bacterial counterparts, was a 12-kdalton (kDa) acidic protein capable of activating chloroplast NADP-malate dehydrogenase (EC 1.1.1.82) more effectively than fructose-1,6-bisphosphatase (EC 3.1.3.11). NADP-thioredoxin reductase (EC 1.6.4.5) was partially purified and found to be an arsenite-sensitive enzyme composed of two 34-kDa subunits. Carrot NADP-thioredoxin reductase resembled more closely its counterpart from bacteria rather than animal cells in acceptor (thioredoxin) specificity. Upon greening of the cells, the content of NADP-thioredoxin-reductase activity, and, to a lesser extent, thioredoxin h decreased. The results confirm the presence of a heterotrophic-type thioredoxin system in plant cells and raise the question of its physiological function.

  18. Obtaining partial purified xylose reductase from Candida guilliermondii

    PubMed Central

    Tomotani, Ester Junko; de Arruda, Priscila Vaz; Vitolo, Michele; de Almeida Felipe, Maria das Graças

    2009-01-01

    The enzymatic bioconversion of xylose into xylitol by xylose reductase (XR) is an alternative for chemical and microbiological processes. The partial purified XR was obtained by using the following three procedures: an agarose column, a membrane reactor or an Amicon Ultra-15 50K Centrifugal Filter device at yields of 40%, 7% and 67%, respectively. PMID:24031408

  19. Dissimilatory Nitrite Reductase Genes from Autotrophic Ammonia-Oxidizing Bacteria

    PubMed Central

    Casciotti, Karen L.; Ward, Bess B.

    2001-01-01

    The presence of a copper-containing dissimilatory nitrite reductase gene (nirK) was discovered in several isolates of β-subdivision ammonia-oxidizing bacteria using PCR and DNA sequencing. PCR primers Cunir3 and Cunir4 were designed based on published nirK sequences from denitrifying bacteria and used to amplify a 540-bp fragment of the nirK gene from Nitrosomonas marina and five additional isolates of ammonia-oxidizing bacteria. Amplification products of the expected size were cloned and sequenced. Alignment of the nucleic acid and deduced amino acid (AA) sequences shows significant similarity (62 to 75% DNA, 58 to 76% AA) between nitrite reductases present in these nitrifiers and the copper-containing nitrite reductase found in classic heterotrophic denitrifiers. While the presence of a nitrite reductase in Nitrosomonas europaea is known from early biochemical work, preliminary sequence data from its genome indicate a rather low similarity to the denitrifier nirKs. Phylogenetic analysis of the partial nitrifier nirK sequences indicates that the topology of the nirK tree corresponds to the 16S rRNA and amoA trees. While the role of nitrite reduction in the metabolism of nitrifying bacteria is still uncertain, these data show that the nirK gene is present in closely related nitrifying isolates from many oceanographic regions and suggest that nirK sequences retrieved from the environment may include sequences from ammonia-oxidizing bacteria. PMID:11319103

  20. 21 CFR 864.7375 - Glutathione reductase assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Glutathione reductase assay. 864.7375 Section 864.7375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7375...

  1. 21 CFR 864.7375 - Glutathione reductase assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Glutathione reductase assay. 864.7375 Section 864.7375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7375...

  2. 21 CFR 864.7375 - Glutathione reductase assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Glutathione reductase assay. 864.7375 Section 864.7375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7375...

  3. Dihydrofolate reductase: A potential drug target in trypanosomes and leishmania

    NASA Astrophysics Data System (ADS)

    Zuccotto, Fabio; Martin, Andrew C. R.; Laskowski, Roman A.; Thornton, Janet M.; Gilbert, Ian H.

    1998-05-01

    Dihydrofolate reductase has successfully been used as a drug target in the area of anti-cancer, anti-bacterial and anti-malarial chemotherapy. Little has been done to evaluate it as a drug target for treatment of the trypanosomiases and leishmaniasis. A crystal structure of Leishmania major dihydrofolate reductase has been published. In this paper, we describe the modelling of Trypanosoma cruzi and Trypanosoma brucei dihydrofolate reductases based on this crystal structure. These structures and models have been used in the comparison of protozoan, bacterial and human enzymes in order to highlight the different features that can be used in the design of selective anti-protozoan agents. Comparison has been made between residues present in the active site, the accessibility of these residues, charge distribution in the active site, and the shape and size of the active sites. Whilst there is a high degree of similarity between protozoan, human and bacterial dihydrofolate reductase active sites, there are differences that provide potential for selective drug design. In particular, we have identified a set of residues which may be important for selective drug design and identified a larger binding pocket in the protozoan than the human and bacterial enzymes.

  4. The Kinetics and Inhibition of the Enzyme Methemoglobin Reductase

    ERIC Educational Resources Information Center

    Splittgerber, A. G.; And Others

    1975-01-01

    Describes an undergraduate biochemistry experiment which involves the preparation and kinetics of an oxidation-reduction enzyme system, methemoglobin reductase. A crude enzyme extract is prepared and assayed spectrophotometrically. The enzyme system obeys Michaelis-Menton kinetics with respect to both substrate and the NADH cofactor. (MLH)

  5. [Malate oxidation by mitochondrial succinate:ubiquinone-reductase].

    PubMed

    Belikova, Iu O; Kotliar, A B

    1988-04-01

    Succinate:ubiquinone reductase was shown to catalyze the oxidation of L- and D-stereoisomers of malate by artificial electron acceptors and ubiquinone. The rate of malate oxidation by succinate:ubiquinone reductase is by two orders of magnitude lower than that for the natural substrate--succinate. The values of kinetic constants for the oxidation of D- and L-stereoisomers of malate are equal to: V infinity = 0.1 mumol/min/mg protein, Km = 2 mM and V infinity = 0.05 mumol/min/mg protein, Km = 2 mM, respectively. The malate dehydrogenase activity is fully inhibited by the inhibitors of the dicarboxylate-binding site of the enzyme, i.e., N-ethylmaleimide and malonate and is practically insensitive to carboxin, a specific inhibitor of the ubiquinone-binding center. The enol form of oxaloacetate was shown to be the product of malate oxidation by succinate:ubiquinone reductase. The kinetics of inhibition of the enzyme activity by the ketone and enol forms of oxaloacetate was studied. Both forms of oxaloacetate effectively inhibit the succinate:ubiquinone reductase reaction.

  6. The arsenic hyperaccumulating Pteris vittata expresses two arsenate reductases

    PubMed Central

    Cesaro, Patrizia; Cattaneo, Chiara; Bona, Elisa; Berta, Graziella; Cavaletto, Maria

    2015-01-01

    Enzymatic reduction of arsenate to arsenite is the first known step in arsenate metabolism in all organisms. Although the presence of one mRNA arsenate reductase (PvACR2) has been characterized in gametophytes of P. vittata, no arsenate reductase protein has been directly observed in this arsenic hyperaccumulating fern, yet. In order to assess the possible presence of arsenate reductase in P. vittata, two recombinant proteins, ACR2-His6 and Trx-His6-S-Pv2.5–8 were prepared in Escherichia coli, purified and used to produce polyclonal antibodies. The presence of these two enzymes was evaluated by qRT-PCR, immunoblotting and direct MS analysis. Enzymatic activity was detected in crude extracts. For the first time we detected and identified two arsenate reductase proteins (PvACR2 and Pv2.5–8) in sporophytes and gametophytes of P. vittata. Despite an increase of the mRNA levels for both proteins in roots, no difference was observed at the protein level after arsenic treatment. Overall, our data demonstrate the constitutive protein expression of PvACR2 and Pv2.5–8 in P. vittata tissues and propose their specific role in the complex metabolic network of arsenic reduction. PMID:26412036

  7. The arsenic hyperaccumulating Pteris vittata expresses two arsenate reductases.

    PubMed

    Cesaro, Patrizia; Cattaneo, Chiara; Bona, Elisa; Berta, Graziella; Cavaletto, Maria

    2015-09-28

    Enzymatic reduction of arsenate to arsenite is the first known step in arsenate metabolism in all organisms. Although the presence of one mRNA arsenate reductase (PvACR2) has been characterized in gametophytes of P. vittata, no arsenate reductase protein has been directly observed in this arsenic hyperaccumulating fern, yet. In order to assess the possible presence of arsenate reductase in P. vittata, two recombinant proteins, ACR2-His6 and Trx-His6-S-Pv2.5-8 were prepared in Escherichia coli, purified and used to produce polyclonal antibodies. The presence of these two enzymes was evaluated by qRT-PCR, immunoblotting and direct MS analysis. Enzymatic activity was detected in crude extracts. For the first time we detected and identified two arsenate reductase proteins (PvACR2 and Pv2.5-8) in sporophytes and gametophytes of P. vittata. Despite an increase of the mRNA levels for both proteins in roots, no difference was observed at the protein level after arsenic treatment. Overall, our data demonstrate the constitutive protein expression of PvACR2 and Pv2.5-8 in P. vittata tissues and propose their specific role in the complex metabolic network of arsenic reduction.

  8. [Inhibition of aldose reductase by Chinese herbal medicine].

    PubMed

    Mao, X M; Zhang, J Q

    1993-10-01

    Seven Chinese herbal drugs were screened for experimental inhibition of lens aldose reductase activity, among which quercetin exhibited potent enzyme-inhibitory activities in vitro. Its IC50 value was 3.44 x 10(-7) mol/L. It may be helpful in the prophylaxis and treatment of diabetic complications.

  9. Characterization of mitochondrial thioredoxin reductase from C. elegans

    SciTech Connect

    Lacey, Brian M.; Hondal, Robert J. . E-mail: Robert.Hondal@uvm.edu

    2006-08-04

    Thioredoxin reductase catalyzes the NADPH-dependent reduction of the catalytic disulfide bond of thioredoxin. In mammals and other higher eukaryotes, thioredoxin reductases contain the rare amino acid selenocysteine at the active site. The mitochondrial enzyme from Caenorhabditis elegans, however, contains a cysteine residue in place of selenocysteine. The mitochondrial C. elegans thioredoxin reductase was cloned from an expressed sequence tag and then produced in Escherichia coli as an intein-fusion protein. The purified recombinant enzyme has a k {sub cat} of 610 min{sup -1} and a K {sub m} of 610 {mu}M using E. coli thioredoxin as substrate. The reported k {sub cat} is 25% of the k {sub cat} of the mammalian enzyme and is 43-fold higher than a cysteine mutant of mammalian thioredoxin reductase. The enzyme would reduce selenocysteine, but not hydrogen peroxide or insulin. The flanking glycine residues of the GCCG motif were mutated to serine. The mutants improved substrate binding, but decreased the catalytic rate.

  10. The arsenic hyperaccumulating Pteris vittata expresses two arsenate reductases

    NASA Astrophysics Data System (ADS)

    Cesaro, Patrizia; Cattaneo, Chiara; Bona, Elisa; Berta, Graziella; Cavaletto, Maria

    2015-09-01

    Enzymatic reduction of arsenate to arsenite is the first known step in arsenate metabolism in all organisms. Although the presence of one mRNA arsenate reductase (PvACR2) has been characterized in gametophytes of P. vittata, no arsenate reductase protein has been directly observed in this arsenic hyperaccumulating fern, yet. In order to assess the possible presence of arsenate reductase in P. vittata, two recombinant proteins, ACR2-His6 and Trx-His6-S-Pv2.5-8 were prepared in Escherichia coli, purified and used to produce polyclonal antibodies. The presence of these two enzymes was evaluated by qRT-PCR, immunoblotting and direct MS analysis. Enzymatic activity was detected in crude extracts. For the first time we detected and identified two arsenate reductase proteins (PvACR2 and Pv2.5-8) in sporophytes and gametophytes of P. vittata. Despite an increase of the mRNA levels for both proteins in roots, no difference was observed at the protein level after arsenic treatment. Overall, our data demonstrate the constitutive protein expression of PvACR2 and Pv2.5-8 in P. vittata tissues and propose their specific role in the complex metabolic network of arsenic reduction.

  11. Treatment of hirsutism with 5 alpha-reductase inhibitors.

    PubMed

    Brooks, J R

    1986-05-01

    Much os the evidence gathered from studies of 5 alpha-reductase activity levels and androgen metabolism in the skin of hirsute women and the excretion of androgen metabolites by hirsute women indicates that 5 alpha-reduced androgens are probably of primary importance in hirsutism. Unfortunately, until very recently, the lack of a suitable 5 alpha-reductase inhibitor made it very difficult to adequately test the hypothesis that such an inhibitor might be useful in the treatment of hirsutism and certain other androgen-related diseases. No substance was available which had good, unambiguous activity in vivo as a 5 alpha-reductase inhibitor. A number of 4-azasteroids have now been found to possess excellent 5 alpha-reductase inhibitory activity both in vitro and in vivo. Among other properties, several of these compounds show little or no affinity for the androgen receptor of rat prostate cytosol, they attenuate the growth promoting effect of T, but not DHT, on the ventral prostate of castrated male rats, they cause a marked reduction in prostatic DHT concentration in acutely treated rats and dogs and they bring about a significant decline in prostate size in chronically treated rats and dogs. It is expected that, in the near future, one or more of these highly active 5 alpha-reductase inhibitors will be tested in the clinic as a treatment for hirsutism. The results of those studies will be awaited with a great deal of interest since they should considerably advance our understanding of this disease and possibly contribute to its control.

  12. Assimilatory nitrate reductase from the green alga Ankistrodesmus braunii.

    PubMed

    De la Rosa, M A

    1983-01-01

    Assimilatory nitrate reductase (NAD(P)H-nitrate oxidoreductase, EC 1.6.6.2) from the green alga Ankistrodesmus braunii can be purified to homogeneity by dye-ligand chromatography on blue-Sepharose. The purified enzyme, whose turnover number is 623 s-1, presents an optimum pH of 7.5 and Km values of 13 microM, 23 microM and 0.15 mM for NADH, NADPH and nitrate, respectively. The NADH-nitrate reductase activity exhibits an iso ping pong bi bi kinetic mechanism. The molecular weight of the native nitrate reductase is 467 400, while that of its subunits is 58 750. These values suggest an octameric structure for the enzyme, which has been confirmed by electron microscopy. As deduced from spectrophotometric and fluorimetric studies, the enzyme contains FAD and cytochrome b-557 as prosthetic groups. FAD is not covalently bound to the protein and is easily dissociated in diluted solutions from the enzyme. Its apparent Km value is 4 nM, indicative of a high affinity of the enzyme for FAD. The results of the quantitative analyses of prosthetic groups indicate that nitrate reductase contains four molecules of flavin, four heme irons, and two atoms of molybdenum. The three components act sequentially transferring electrons from reduced pyridine nucleotides to nitrate, thus forming a short electron transport chain along the protein. A mechanism is proposed for the redox interconversion of the nitrate reductase activity. Inactivation seems to occur by formation of a stable complex of reduced enzyme with cyanide or superoxide, while reactivation is a consequence of reoxidation of the inactive enzyme. Both reactions imply the transfer of only one electron.

  13. Measurement of nitrous oxide reductase activity in aquatic sediments

    SciTech Connect

    Miller, L.G.; Oremland, R.S.; Paulsen, S.

    1986-01-01

    Denitrification in aquatic sediments was measured by an N/sub 2/O reductase assay. Sediments consumed small added quantities of N/sub 2/O over short periods (a few hours). In experiments with sediment slurries, N/sub 2/O reductase activity was inhibited by 0/sub 2/, C/sub 2/H/sub 2/, heat treatment, and by high levels of nitrate (1 mM) or sulfide (10 mM). However, ambient levels of nitrate (<100 ..mu..M) did not influence activity, and moderate levels (about 150 ..mu..M) induced only a short lag before reductase activity began. Moderate levels of sulfide (<1 mM) had no effect on N/sub 2/O reductase activity. Nitrous oxide reductase displayed Michaelis-Menten kinetics in sediments from freshwater, estuarine, and alkaline-saline environments. An in situ assay was devised in which a solution of N/sub 2/O was injected into sealed glass cores containing intact sediment. Two estimates of net rates of denitrification in San Francisco Bay under approximated in situ conditions were 0.009 and 0.041 mmol of N/sub 2/O per m/sup 2/ per h. Addition of chlorate to inhibit denitrification in these intact-core experiments (to estimate gross rates of N/sub 2/O consumption) resulted in approximately a 14% upward revision of estimates of net rates. These results were comparable to an in situ estimate of 0.022 mmol of N/sub 2/O per m/sup 2/ per h made with the acetylene block assay.

  14. Measurement of nitrous oxide reductase activity in aquatic sediments

    USGS Publications Warehouse

    Miller, L.G.; Oremland, R.S.; Paulsen, S.

    1986-01-01

    Denitrification in aquatic sediments was measured by an N2O reductase assay. Sediments consumed small added quantities of N2O over short periods (a few hours). In experiments with sediment slurries, N2O reductase activity was inhibited by O2, C2H2, heat treatment, and by high levels of nitrate (1 mM) or sulfide (10 mM). However, ambient levels of nitrate (<100 μM) did not influence activity, and moderate levels (about 150 μM) induced only a short lag before reductase activity began. Moderate levels of sulfide (<1 mM) had no effect on N2O reductase activity. Nitrous oxide reductase displayed Michaelis-Menten kinetics in sediments from freshwater (Km = 2.17 μM), estuarine (Km = 14.5 μM), and alkaline-saline (Km = 501 μM) environments. An in situ assay was devised in which a solution of N2O was injected into sealed glass cores containing intact sediment. Two estimates of net rates of denitrification in San Francisco Bay under approximated in situ conditions were 0.009 and 0.041 mmol of N2O per m2 per h. Addition of chlorate to inhibit denitrification in these intact-core experiments (to estimate gross rates of N2O consumption) resulted in approximately a 14% upward revision of estimates of net rates. These results were comparable to an in situ estimate of 0.022 mmol of N2O per m2 per h made with the acetylene block assay.

  15. Identification and characterization of 2-naphthoyl-coenzyme A reductase, the prototype of a novel class of dearomatizing reductases.

    PubMed

    Eberlein, Christian; Estelmann, Sebastian; Seifert, Jana; von Bergen, Martin; Müller, Michael; Meckenstock, Rainer U; Boll, Matthias

    2013-06-01

    The enzymatic dearomatization of aromatic ring systems by reduction represents a highly challenging redox reaction in biology and plays a key role in the degradation of aromatic compounds under anoxic conditions. In anaerobic bacteria, most monocyclic aromatic growth substrates are converted to benzoyl-coenzyme A (CoA), which is then dearomatized to a conjugated dienoyl-CoA by ATP-dependent or -independent benzoyl-CoA reductases. It was unresolved whether or not related enzymes are involved in the anaerobic degradation of environmentally relevant polycyclic aromatic hydrocarbons (PAHs). In this work, a previously unknown dearomatizing 2-naphthoyl-CoA reductase was purified from extracts of the naphthalene-degrading, sulphidogenic enrichment culture N47. The oxygen-tolerant enzyme dearomatized the non-activated ring of 2-naphthoyl-CoA by a four-electron reduction to 5,6,7,8-tetrahydro-2-naphthoyl-CoA. The dimeric 150 kDa enzyme complex was composed of a 72 kDa subunit showing sequence similarity to members of the flavin-containing 'old yellow enzyme' family. NCR contained FAD, FMN, and an iron-sulphur cluster as cofactors. Extracts of Escherichia coli expressing the encoding gene catalysed 2-naphthoyl-CoA reduction. The identified NCR is a prototypical enzyme of a previously unknown class of dearomatizing arylcarboxyl-CoA reductases that are involved in anaerobic PAH degradation; it fundamentally differs from known benzoyl-CoA reductases.

  16. Crystal structures of pinoresinol-lariciresinol and phenylcoumaran benzylic ether reductases and their relationship to isoflavone reductases

    NASA Technical Reports Server (NTRS)

    Min, Tongpil; Kasahara, Hiroyuki; Bedgar, Diana L.; Youn, Buhyun; Lawrence, Paulraj K.; Gang, David R.; Halls, Steven C.; Park, HaJeung; Hilsenbeck, Jacqueline L.; Davin, Laurence B.; Lewis, Norman G.; Kang, ChulHee

    2003-01-01

    Despite the importance of plant lignans and isoflavonoids in human health protection (e.g. for both treatment and prevention of onset of various cancers) as well as in plant biology (e.g. in defense functions and in heartwood development), systematic studies on the enzymes involved in their biosynthesis have only recently begun. In this investigation, three NADPH-dependent aromatic alcohol reductases were comprehensively studied, namely pinoresinol-lariciresinol reductase (PLR), phenylcoumaran benzylic ether reductase (PCBER), and isoflavone reductase (IFR), which are involved in central steps to the various important bioactive lignans and isoflavonoids. Of particular interest was in determining how differing regio- and enantiospecificities are achieved with the different enzymes, despite each apparently going through similar enone intermediates. Initially, the three-dimensional x-ray crystal structures of both PLR_Tp1 and PCBER_Pt1 were solved and refined to 2.5 and 2.2 A resolutions, respectively. Not only do they share high gene sequence similarity, but their structures are similar, having a continuous alpha/beta NADPH-binding domain and a smaller substrate-binding domain. IFR (whose crystal structure is not yet obtained) was also compared (modeled) with PLR and PCBER and was deduced to have the same overall basic structure. The basis for the distinct enantio-specific and regio-specific reactions of PCBER, PLR, and IFR, as well as the reaction mechanism and participating residues involved (as identified by site-directed mutagenesis), are discussed.

  17. Reduced impact of pyrimethamine drug pressure on Plasmodium malariae dihydrofolate reductase gene.

    PubMed

    Khim, Nimol; Kim, Saorin; Bouchier, Christiane; Tichit, Magali; Ariey, Frédéric; Fandeur, Thierry; Chim, Pheaktra; Ke, Sopheakvatey; Sum, Sarorn; Man, Somnang; Ratsimbasoa, Arsène; Durand, Rémy; Ménard, Didier

    2012-02-01

    Molecular investigations performed following the emergence of sulfadoxine-pyrimethamine (SP) resistance in Plasmodium falciparum have allowed the identification of the dihydrofolate reductase (DHFR) enzyme as the target of pyrimethamine. Although clinical cases of Plasmodium malariae are not usually treated with antifolate therapy, incorrect diagnosis and the high frequency of undetected mixed infections has probably exposed non-P. falciparum parasites to antifolate therapy in many areas. In this context, we aimed to assess the worldwide genetic diversity of the P. malariae dhfr gene in 123 samples collected in Africa and Asia, areas with different histories of SP use. Among the 10 polymorphic sites found, we have observed 7 new mutations (K55E, S58R, S59A, F168S, N194S, D207G, and T221A), which led us to describe 6 new DHFR proteins. All isolates from African countries were classified as wild type, while new mutations and haplotypes were recognized as exclusive to Madagascar (except for the double mutations at nucleotides 341 and 342 [S114N] found in one Cambodian isolate). Among these nonsynonymous mutations, two were likely related to pyrimethamine resistance: S58R (corresponding to C59R in P. falciparum and S58R in Plasmodium vivax; observed in one Malagasy sample) and S114N (corresponding to S108N in P. falciparum and S117N in P. vivax; observed in three Cambodian samples).

  18. Reduced Impact of Pyrimethamine Drug Pressure on Plasmodium malariae Dihydrofolate Reductase Gene

    PubMed Central

    Khim, Nimol; Kim, Saorin; Bouchier, Christiane; Tichit, Magali; Ariey, Frédéric; Fandeur, Thierry; Chim, Pheaktra; Ke, Sopheakvatey; Sum, Sarorn; Man, Somnang; Ratsimbasoa, Arsène; Durand, Rémy

    2012-01-01

    Molecular investigations performed following the emergence of sulfadoxine-pyrimethamine (SP) resistance in Plasmodium falciparum have allowed the identification of the dihydrofolate reductase (DHFR) enzyme as the target of pyrimethamine. Although clinical cases of Plasmodium malariae are not usually treated with antifolate therapy, incorrect diagnosis and the high frequency of undetected mixed infections has probably exposed non-P. falciparum parasites to antifolate therapy in many areas. In this context, we aimed to assess the worldwide genetic diversity of the P. malariae dhfr gene in 123 samples collected in Africa and Asia, areas with different histories of SP use. Among the 10 polymorphic sites found, we have observed 7 new mutations (K55E, S58R, S59A, F168S, N194S, D207G, and T221A), which led us to describe 6 new DHFR proteins. All isolates from African countries were classified as wild type, while new mutations and haplotypes were recognized as exclusive to Madagascar (except for the double mutations at nucleotides 341 and 342 [S114N] found in one Cambodian isolate). Among these nonsynonymous mutations, two were likely related to pyrimethamine resistance: S58R (corresponding to C59R in P. falciparum and S58R in Plasmodium vivax; observed in one Malagasy sample) and S114N (corresponding to S108N in P. falciparum and S117N in P. vivax; observed in three Cambodian samples). PMID:22123682

  19. Ribonucleotide reductases reveal novel viral diversity and predict biological and ecological features of unknown marine viruses

    PubMed Central

    Sakowski, Eric G.; Munsell, Erik V.; Hyatt, Mara; Kress, William; Williamson, Shannon J.; Nasko, Daniel J.; Polson, Shawn W.; Wommack, K. Eric

    2014-01-01

    Virioplankton play a crucial role in aquatic ecosystems as top-down regulators of bacterial populations and agents of horizontal gene transfer and nutrient cycling. However, the biology and ecology of virioplankton populations in the environment remain poorly understood. Ribonucleotide reductases (RNRs) are ancient enzymes that reduce ribonucleotides to deoxyribonucleotides and thus prime DNA synthesis. Composed of three classes according to O2 reactivity, RNRs can be predictive of the physiological conditions surrounding DNA synthesis. RNRs are universal among cellular life, common within viral genomes and virioplankton shotgun metagenomes (viromes), and estimated to occur within >90% of the dsDNA virioplankton sampled in this study. RNRs occur across diverse viral groups, including all three morphological families of tailed phages, making these genes attractive for studies of viral diversity. Differing patterns in virioplankton diversity were clear from RNRs sampled across a broad oceanic transect. The most abundant RNRs belonged to novel lineages of podoviruses infecting α-proteobacteria, a bacterial class critical to oceanic carbon cycling. RNR class was predictive of phage morphology among cyanophages and RNR distribution frequencies among cyanophages were largely consistent with the predictions of the “kill the winner–cost of resistance” model. RNRs were also identified for the first time to our knowledge within ssDNA viromes. These data indicate that RNR polymorphism provides a means of connecting the biological and ecological features of virioplankton populations. PMID:25313075

  20. Disappearing Polymorphs Revisited

    PubMed Central

    Bučar, Dejan-Krešimir; Lancaster, Robert W; Bernstein, Joel

    2015-01-01

    Nearly twenty years ago, Dunitz and Bernstein described a selection of intriguing cases of polymorphs that disappear. The inability to obtain a crystal form that has previously been prepared is indeed a frustrating and potentially serious problem for solid-state scientists. This Review discusses recent occurrences and examples of disappearing polymorphs (as well as the emergence of elusive crystal forms) to demonstrate the enduring relevance of this troublesome, but always captivating, phenomenon in solid-state research. A number of these instances have been central issues in patent litigations. This Review, therefore, also highlights the complex relationship between crystal chemistry and the law. PMID:26031248

  1. Immunological approach to the regulation of nitrate reductase in Monoraphidium braunii.

    PubMed

    Díez, J; López-Ruiz, A

    1989-02-01

    The effects of different culture conditions on nitrate reductase activity and nitrate reductase protein from Monoraphidium braunii have been studied, using two different immunological techniques, rocket immunoelectrophoresis and an enzyme-linked immunosorbent assay, to determine nitrate reductase protein. The nitrogen sources ammonium and glutamine repressed nitrate reductase synthesis, while nitrite, alanine, and glutamate acted as derepressors. There was a four- to eightfold increase of nitrate reductase activity and a twofold increase of nitrate reductase protein under conditions of nitrogen starvation versus growth on nitrate. Nitrate reductase synthesis was repressed in darkness. However, when Monoraphidium was grown under heterotrophic conditions with glucose as the carbon and energy source, the synthesis of nitrate reductase was maintained. With ammonium or darkness, changes in nitrate reductase activity correlated fairly well with changes in nitrate reductase protein, indicating that in both cases loss of activity was due to repression and not to inactivation of the enzyme. Experiments using methionine sulfoximine, to inhibit ammonium assimilation, showed that ammonium per se and not a product of its metabolism was the corepressor of the enzyme. The appearance of nitrate reductase activity after transferring the cells to induction media was prevented by cycloheximide and by 6-methylpurine, although in this latter case the effect was observed only in cells preincubated with the inhibitor for 1 h before the induction period.

  2. Recominant Pinoresino-Lariciresinol Reductase, Recombinant Dirigent Protein And Methods Of Use

    DOEpatents

    Lewis, Norman G.; Davin, Laurence B.; Dinkova-Kostova, Albena T.; Fujita, Masayuki , Gang; David R. , Sarkanen; Simo , Ford; Joshua D.

    2003-10-21

    Dirigent proteins and pinoresinol/lariciresinol reductases have been isolated, together with cDNAs encoding dirigent proteins and pinoresinol/lariciresinol reductases. Accordingly, isolated DNA sequences are provided from source species Forsythia intermedia, Thuja plicata, Tsuga heterophylla, Eucommia ulmoides, Linum usitatissimum, and Schisandra chinensis, which code for the expression of dirigent proteins and pinoresinol/lariciresinol reductases. In other aspects, replicable recombinant cloning vehicles are provided which code for dirigent proteins or pinoresinol/lariciresinol reductases or for a base sequence sufficiently complementary to at least a portion of dirigent protein or pinoresinol/lariciresinol reductase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding dirigent protein or pinoresinol/lariciresinol reductase. Thus, systems and methods are provided for the recombinant expression of dirigent proteins and/or pinoresinol/lariciresinol reductases.

  3. Recombinant pinoresinol/lariciresinol reductase, recombinant dirigent protein, and methods of use

    DOEpatents

    Lewis, Norman G.; Davin, Laurence B.; Dinkova-Kostova, Albena T.; Fujita, Masayuki; Gang, David R.; Sarkanen, Simo; Ford, Joshua D.

    2001-04-03

    Dirigent proteins and pinoresinol/lariciresinol reductases have been isolated, together with cDNAs encoding dirigent proteins and pinoresinol/lariciresinol reductases. Accordingly, isolated DNA sequences are provided which code for the expression of dirigent proteins and pinoresinol/lariciresinol reductases. In other aspects, replicable recombinant cloning vehicles are provided which code for dirigent proteins or pinoresinol/lariciresinol reductases or for a base sequence sufficiently complementary to at least a portion of dirigent protein or pinoresinol/lariciresinol reductase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding dirigent protein or pinoresinol/lariciresinol reductase. Thus, systems and methods are provided for the recombinant expression of dirigent proteins and/or pinoresinol/lariciresinol reductases.

  4. The X-ray crystal structure of APR-B, an atypical adenosine 5'-phosphosulfate reductase from Physcomitrella patens.

    PubMed

    Stevenson, Clare E M; Hughes, Richard K; McManus, Michael T; Lawson, David M; Kopriva, Stanislav

    2013-11-15

    Sulfonucleotide reductases catalyse the first reductive step of sulfate assimilation. Their substrate specificities generally correlate with the requirement for a [Fe4S4] cluster, where adenosine 5'-phosphosulfate (APS) reductases possess a cluster and 3'-phosphoadenosine 5'-phosphosulfate reductases do not. The exception is the APR-B isoform of APS reductase from the moss Physcomitrella patens, which lacks a cluster. The crystal structure of APR-B, the first for a plant sulfonucleotide reductase, is consistent with a preference for APS. Structural conservation with bacterial APS reductase rules out a structural role for the cluster, but supports the contention that it enhances the activity of conventional APS reductases.

  5. Polymorphism of sorbitol

    NASA Astrophysics Data System (ADS)

    Nezzal, Amale; Aerts, Luc; Verspaille, Marleen; Henderickx, Geert; Redl, Andreas

    2009-07-01

    The polymorphism of sorbitol was investigated, confirming the existence of four anhydrous crystalline phases plus the hydrate. The crystallised melt (CM), the alpha form, and the gamma form were obtained via a dry route. The CM was confirmed to be a crystalline state with a spherulite morphology. The alpha form was obtained via direct conversion from the CM, in contrast to more complicated routes previously reported, and was found to have a very high crystallinity. Gamma crystals were obtained by seeding the melt at high temperature; however, crystallinity was clearly less than for alpha crystals. Despite its lower crystallinity, the gamma polymorph was found to be the most stable of the anhydrous crystalline forms; this was confirmed by its high melting point and low hygroscopicity. In contrast, the alpha polymorph has a relatively high melting point but lacks moisture stability at high relative humidity. The hydrate form has the same resistance to moisture as the gamma form, but melts at a lower temperature. The combination of both a high melting point and high stability in the presence of water makes the gamma polymorph best suited for confectionary applications.

  6. Investigation of Uranium Polymorphs

    SciTech Connect

    Sweet, Lucas E.; Henager, Charles H.; Hu, Shenyang Y.; Johnson, Timothy J.; Meier, David E.; Peper, Shane M.; Schwantes, Jon M.

    2011-08-01

    The UO3-water system is complex and has not been fully characterized, even though these species are common throughout the nuclear fuel cycle. As an example, most production schemes for UO3 result in a mixture of up to six or more different polymorphic phases, and small differences in these conditions will affect phase genesis that ultimately result in measureable changes to the end product. As a result, this feature of the UO3-water system may be useful as a means for determining process history. This research effort attempts to better characterize the UO3-water system with a variety of optical techniques for the purpose of developing some predictive capability for estimating process history in polymorphic phases of unknown origin. Three commercially relevant preparation methods for the production of UO3 were explored. Previously unreported low temperature routes to β- and γ-UO3 were discovered. Raman and fluorescence spectroscopic libraries were established for pure and mixed polymorphic forms of UO3 in addition to the common hydrolysis products of UO3. An advantage of the sensitivity of optical fluorescence microscopy over XRD has been demonstrated. Preliminary aging studies of the α and γ forms of UO3 have been conducted. In addition, development of a 3-D phase field model used to predict phase genesis of the system was initiated. Thermodynamic and structural constants that will feed the model have been gathered from the literature for most of the UO3 polymorphic phases.

  7. Enzyme polymorphisms in Canarium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fifty-two accessions of Canarium involving seven species, C. ovatum, C. album, C. megalanthum, C. harveyi, C. indicum, C. mehenbethene, and C. odontophyllum were studied for isozyme polymorphisms. Starch gel electrophoresis with a histidine-citrate buffer system (pH 6.5) was employed to assay six en...

  8. Polymorphism of clotting factors in Hungarian patients with Raynaud's phenomenon.

    PubMed

    Shemirani, Amir-Houshang; Szomják, Edit; Balogh, Emese; András, Csilla; Kovács, Dóra; Acs, Judit; Csiki, Zoltán

    2011-01-01

    Patients with primary Raynaud's phenomenon may have a genetically determined risk for clotting factors that predispose them to aberrant microvascular thrombosis. We investigated the prevalence of factor V substitution of G to A at position 1691 (FVLeiden), prothrombin G20210A, and methyltetrahydrofolate reductase C677T mutations in these patients. Two hundred (158 women, 42 men, mean age of 42.4 ± 13.7 years) consecutive patients with primary Raynaud's phenomenon and 200 age-sex-matched healthy controls of Hungarian origin were included in a case-control study. The prevalence of methyltetrahydrofolate reductase C677T homozygous among patients was significantly lower than in the control group (odds ratio 0.4, 95% confidence interval 0.2-0.9, P < 0.05). The prevalence of other thrombosis-associated alleles did not differ between patients with primary Raynaud's phenomenon and control subjects. FVLeiden, prothrombin G20210A, and polymorphism, prothrombin G20210A mutations have no apparent effect on the etiology of primary Raynaud's phenomenon.

  9. Is MTHFD1 polymorphism rs 2236225 (c.1958G>A) associated with the susceptibility of NSCL/P? A systematic review and meta-analysis

    PubMed Central

    Zhao, Huaxiang; Zhang, Jieni; Zhang, Mengqi; Deng, Feng; Zheng, Leilei; Zheng, Hui; Chen, Feng; Lin, Jiuxiang

    2016-01-01

    Aims: To investigate the association between the methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) polymorphism rs 2236225 (c.1958G>A) and susceptibility to non-syndromic cleft of the lip and/or palate (NSCL/P). Methods: An extensive literature review has been conducted using PubMed, Web of Science, Cochrane Library, Google Scholar, the China National Knowledge Infrastructure (CNKI), and Wanfang Database for eligible researches. The terms for searching were “cleft lip OR cleft palate OR CLP OR CL/P OR oral facial cleft OR OFC” AND “methylenetetrahydrofolate dehydrogenase (NADP+ dependent) 1 OR methenyltetrahydrofolate cyclohydrolase formyltetrahydrofolate synthetase OR MTHFD1 OR MTHFD”. Two independent researchers screened, evaluated and extracted the data of included studies. The pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated by random effects model under five gene models. Subgroup, sensitivity analysis and publication bias were also assessed. Results: Ten case-control studies have been included in the systematic review and eight studies have been considered for the meta-analysis. Overall, the MTHFD1 polymorphism rs2236225 and the risk of NSCL/P showed pooled OR (95% CI) of 1.02 (0.86-1.21) under allelic model. A higher degree of heterogeneity was observed in Asian countries (I 2 = 75.6%) compared to non-Asian countries (I 2 = 48.9%). Similar consequence appeared in the subgroup of children (I 2 = 78.6%) compared with that of mothers (I 2 = 0.0%). There was no significant difference in the publication bias by the Begg’s funnel plot (P = 0.711) and Egger’s regression test (P = 0.746). Conclusion: Our assessment suggested there was no significant association between the MTHFD1 polymorphism rs 2236225 (c.1958G>A) and the susceptibility to NSCL/P. Further investigations using a large sample size and a more advanced technique should be adopted to reach a more precise conclusion in the future. PMID:26834978

  10. Association study of sorbitol dehydrogenase -888G>C polymorphism with type 2 diabetic retinopathy in Caucasian-Brazilians.

    PubMed

    Ferreira, Fábio Netto; Crispim, Daisy; Canani, Luís Henrique; Gross, Jorge Luiz; dos Santos, Kátia Gonçalves

    2013-10-01

    Diabetic retinopathy (DR) is a common chronic complication of diabetes and remains the leading cause of blindness in working-aged people. Hyperglycemia increases glucose flux through the polyol pathway, in which aldose reductase converts glucose into intracellular sorbitol, which is subsequently converted to fructose by sorbitol dehydrogenase (SDH). The accelerated polyol pathway triggers a cascade of events leading to retinal vascular endothelial dysfunction and the eventual development of DR. Polymorphisms in the gene encoding aldose reductase have been consistently associated with DR. However, only two studies have analyzed the relationship between polymorphisms in the gene encoding SDH (SORD) and DR. In this case-control study, we investigated whether the -888G > C polymorphism (rs3759890) in the SORD gene is associated with the presence or severity of DR in 446 Caucasian-Brazilians with type 2 diabetes (241 subjects with and 205 subjects without DR). The -888G > C polymorphism was also examined in 105 healthy Caucasian blood donors, and the genotyping of this polymorphism was carried out by real-time PCR. The genotype and allele frequencies of the -888G > C polymorphism in patients with type 2 diabetes were similar to those of blood donors (G allele frequency = 0.16 in both groups of subjects). Similarly, the genotype and allele frequencies in patients with DR or the proliferative form of DR were similar to those of patients without this complication (P > 0.05 for all comparisons). Thus, our findings suggest that the -888G > C polymorphism in the SORD gene is not involved in the pathogenesis of DR in type 2 diabetes.

  11. The respiratory arsenate reductase from Bacillus selenitireducens strain MLS10

    USGS Publications Warehouse

    Afkar, E.; Lisak, J.; Saltikov, C.; Basu, P.; Oremland, R.S.; Stolz, J.F.

    2003-01-01

    The respiratory arsenate reductase from the Gram-positive, haloalkaliphile, Bacillus selenitireducens strain MLS10 was purified and characterized. It is a membrane bound heterodimer (150 kDa) composed of two subunits ArrA (110 kDa) and ArrB (34 kDa), with an apparent Km for arsenate of 34 ??M and Vmax of 2.5 ??mol min-1 mg-1. Optimal activity occurred at pH 9.5 and 150 g l-1 of NaCl. Metal analysis (inductively coupled plasma mass spectrometry) of the holoenzyme and sequence analysis of the catalytic subunit (ArrA; the gene for which was cloned and sequenced) indicate it is a member of the DMSO reductase family of molybdoproteins. ?? 2003 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.

  12. Pyrroline-5-Carboxylate Reductase in Soybean Nodules 1

    PubMed Central

    Chilson, Oscar P.; Kelly-Chilson, Anne E.; Schneider, Julie D.

    1992-01-01

    Characteristics of pyrroline-5-carboxylate reductase (P5CR) from Bradyrhizobium japonicum bacteroids and cultured rhizobia were compared with those of the enzyme in soybean nodule host cytosol. Reductase from host cytosol differed from that in bacteroids in: (a) the effect of pH on enzymic activity, (b) the capacity to catalyze both reduction of pyrroline-5-carboxylic acid and NAD+-dependent proline oxidation, (c) apparent affinities for pyrroline-5-carboxylic acid, and (d) sensitivities to inhibition by NADP+ and proline. The K1 for proline inhibition of P5CR in bacteroid cytosol was 1.8 millimolar. The properties of P5CR in B. japonicum and bacteroid cytosol were similar. The specific activities of P5CR in the cytosolic fractions of the nodule host and the bacteroid compartment were also comparable. PMID:16668837

  13. Characterization of 12-Oxo-Phytodienoic Acid Reductase in Corn

    PubMed Central

    Vick, Brady A.; Zimmerman, Don C.

    1986-01-01

    12-Oxo-phytodienoic acid reductase, an enzyme of the biosynthetic pathway that converts linolenic acid to jasmonic acid, has been characterized from the kernel and seedlings of corn (Zea mays L.). The molecular weight of the enzyme, estimated by gel filtration, was 54,000. Optimum enzyme activity was observed over a broad pH range, from pH 6.8 to 9.0. The enzyme had a Km of 190 micromolar for its substrate, 12-oxo-phytodienoic acid. The preferred reductant was NADPH, for which the enzyme exhibited a Km of 13 micromolar, compared with 4.2 millimolar for NADH. Reductase activity was low in the corn kernel but increased five-fold by the fifth day after germination and then gradually declined. PMID:16664582

  14. [Properties of a nitrite reductase inhibitor protein from Pseudomonas aeruginosa].

    PubMed

    Karapetian, A V; Nalbandian, R M

    1993-08-01

    The amino acid composition and major physico-chemical properties of the "nonblue" copper protein isolated earlier from Pseudomonas aeruginosa have been determined. It has been found that the azurin oxidase, cytochrome c551 oxidase and superoxide dismutase activities of the enzyme are inhibited by this protein. The inhibition seems to be due to the protein interaction with the electron-accepting center of nitrite reductase.

  15. Aldose and aldehyde reductases : structure-function studies on the coenzyme and inhibitor-binding sites.

    SciTech Connect

    El-Kabbani, O.; Old, S. E.; Ginell, S. L.; Carper, D. A.; Biosciences Division; Monash Univ.; NIH

    1999-09-03

    PURPOSE: To identify the structural features responsible for the differences in coenzyme and inhibitor specificities of aldose and aldehyde reductases. METHODS: The crystal structure of porcine aldehyde reductase in complex with NADPH and the aldose reductase inhibitor sorbinil was determined. The contribution of each amino acid lining the coenzyme-binding site to the binding of NADPH was calculated using the Discover package. In human aldose reductase, the role of the non-conserved Pro 216 (Ser in aldehyde reductase) in the binding of coenzyme was examined by site-directed mutagenesis. RESULTS: Sorbinil binds to the active site of aldehyde reductase and is hydrogen-bonded to Trp 22, Tyr 50, His 113, and the non-conserved Arg 312. Unlike tolrestat, the binding of sorbinil does not induce a change in the side chain conformation of Arg 312. Mutation of Pro 216 to Ser in aldose reductase makes the binding of coenzyme more similar to that of aldehyde reductase. CONCLUSIONS: The participation of non-conserved active site residues in the binding of inhibitors and the differences in the structural changes required for the binding to occur are responsible for the differences in the potency of inhibition of aldose and aldehyde reductases. We report that the non-conserved Pro 216 in aldose reductase contributes to the tight binding of NADPH.

  16. Early diagnosis and management of 5 alpha-reductase deficiency.

    PubMed Central

    Odame, I; Donaldson, M D; Wallace, A M; Cochran, W; Smith, P J

    1992-01-01

    Two siblings of Pakistani origin, karyotype 46 XY, were born with predominantly female external genitalia with minute phallus, bifid scrotum, urogenital sinus, and palpable gonads. The older sibling at the age of 8 days showed an adequate testosterone response to human chorionic gonadotrophin (hCG) stimulation. The diagnosis of 5 alpha-reductase deficiency was made at age 6 years when no 5 alpha-reduced glucocorticoid metabolites were detectable in urine even after tetracosactrin (Synacthen) stimulation. In the younger sibling the diagnosis of 5 alpha-reductase deficiency was provisionally made at the early age of 3 days on the basis of high urinary tetrahydrocortisol (THF)/allotetrahydrocortisol (5 alpha-THF) ratio and this ratio increased with age confirming the diagnosis. Plasma testosterone: dihydrotestosterone (DHT) ratio before and after hCG stimulation was within normal limits at age 3 days but was raised at age 9 months. Topical DHT cream application to the external genitalia promoted significant phallic growth in both siblings and in the older sibling corrective surgery was facilitated. In prepubertal male pseudohermaphrodites with normal or raised testosterone concentrations, phallic growth in response to DHT cream treatment could be an indirect confirmation of 5 alpha-reductase deficiency. Images Figure 1 PMID:1626992

  17. Cloning and Sequence Analysis of Two Pseudomonas Flavoprotein Xenobiotic Reductases

    PubMed Central

    Blehert, David S.; Fox, Brian G.; Chambliss, Glenn H.

    1999-01-01

    The genes encoding flavin mononucleotide-containing oxidoreductases, designated xenobiotic reductases, from Pseudomonas putida II-B and P. fluorescens I-C that removed nitrite from nitroglycerin (NG) by cleavage of the nitroester bond were cloned, sequenced, and characterized. The P. putida gene, xenA, encodes a 39,702-Da monomeric, NAD(P)H-dependent flavoprotein that removes either the terminal or central nitro groups from NG and that reduces 2-cyclohexen-1-one but did not readily reduce 2,4,6-trinitrotoluene (TNT). The P. fluorescens gene, xenB, encodes a 37,441-Da monomeric, NAD(P)H-dependent flavoprotein that exhibits fivefold regioselectivity for removal of the central nitro group from NG and that transforms TNT but did not readily react with 2-cyclohexen-1-one. Heterologous expression of xenA and xenB was demonstrated in Escherichia coli DH5α. The transcription initiation sites of both xenA and xenB were identified by primer extension analysis. BLAST analyses conducted with the P. putida xenA and the P. fluorescens xenB sequences demonstrated that these genes are similar to several other bacterial genes that encode broad-specificity flavoprotein reductases. The prokaryotic flavoprotein reductases described herein likely shared a common ancestor with old yellow enzyme of yeast, a broad-specificity enzyme which may serve a detoxification role in antioxidant defense systems. PMID:10515912

  18. The existence and significance of a mitochondrial nitrite reductase.

    PubMed

    Nohl, Hans; Staniek, Katrin; Kozlov, Andrey V

    2005-01-01

    The physiological functions of nitric oxide (NO) are well established. The finding that the endothelium-derived relaxing factor (EDRF) is NO was totally unexpected. It was shown that NO is a reaction product of an enzymatically catalyzed, overall, 5-electron oxidation of guanidinium nitrogen from L-arginine followed by the release of the free radical species NO. NO is synthesized by a single protein complex supported by cofactors, coenzymes (such as tetrahydrobiopterin) and cytochrome P450. The latter can uncouple from substrate oxidation producing O2*- radicals. The research groups of Richter [Ghafourifar P, Richter C. Nitric oxide synthase activity in mitochondria. FEBS Lett 1997; 418: 291-296.] and Boveris [Giulivi C, Poderoso JJ, Boveris A. Production of nitric oxide by mitochondria. J Biol Chem 1998; 273: 11038-11043.] identified a mitochondrial NO synthase (NOS). There are, however, increasing reports demonstrating that mitochondrial NO is derived from cytosolic NOS belonging to the Ca2+-dependent enzymes. NO was thought to control cytochrome oxidase. This assumption is controversial due to the life-time of NO in biological systems (millisecond range). We found a nitrite reductase in mitochondria which is of major interest. Any increase of nitrite in the tissue which is the first oxidation product of NO, for instance following NO donors, will stimulate NO-recycling via mitochondrial nitrite reductase. In this paper, we describe the identity and the function of mitochondrial nitrite reductase and the consequences of NO-recycling in the metabolic compartment of mitochondria.

  19. Phosphoglycerate kinase acts in tumour angiogenesis as a disulphide reductase

    NASA Astrophysics Data System (ADS)

    Lay, Angelina J.; Jiang, Xing-Mai; Kisker, Oliver; Flynn, Evelyn; Underwood, Anne; Condron, Rosemary; Hogg, Philip J.

    2000-12-01

    Disulphide bonds in secreted proteins are considered to be inert because of the oxidizing nature of the extracellular milieu. An exception to this rule is a reductase secreted by tumour cells that reduces disulphide bonds in the serine proteinase plasmin. Reduction of plasmin initiates proteolytic cleavage in the kringle 5 domain and release of the tumour blood vessel inhibitor angiostatin. New blood vessel formation or angiogenesis is critical for tumour expansion and metastasis. Here we show that the plasmin reductase isolated from conditioned medium of fibrosarcoma cells is the glycolytic enzyme phosphoglycerate kinase. Recombinant phosphoglycerate kinase had the same specific activity as the fibrosarcoma-derived protein. Plasma of mice bearing fibrosarcoma tumours contained several-fold more phosphoglycerate kinase, as compared with mice without tumours. Administration of phosphoglycerate kinase to tumour-bearing mice caused an increase in plasma levels of angiostatin, and a decrease in tumour vascularity and rate of tumour growth. Our findings indicate that phosphoglycerate kinase not only functions in glycolysis but is secreted by tumour cells and participates in the angiogenic process as a disulphide reductase.

  20. The effect of quercetin and galangin on glutathione reductase.

    PubMed

    Paulíková, Helena; Berczeliová, Elena

    2005-12-01

    Quercetin and galangin can change the activity of glutathione reductase. Quercetin (a catechol structure in the B-ring) and galangin (any hydroxyl group in the B-ring) have different biological activities but, both possess high antioxidant abilities. Quercetin during the antioxidative action, is converted into an oxidized products (o-semiquinone and o-quinone), and subsequently glutathionyl adducts may be formed or SH-enzyme can be inhibited. We have tried to see whether inhibition of glutathione reductase (GR) can be influenced by preincubation of enzyme with NADPH (a creation of reduced form of enzyme, GRH(2)) and whether diaphorase activity of the enzyme is decreased by these flavonoids. The results confirmed that quercetin inhibits GRH(2) and inhibition is reduced by addition of EDTA or N-acetylcysteine. Both of flavonoids have no effect on diaphorase activity of glutathione reductase and this enzyme could increase the production of free radicals by catalysis of reduction of o-quinone during action of quercetin in vivo.

  1. Catalytic mechanism and substrate selectivity of aldo-keto reductases: insights from structure-function studies of Candida tenuis xylose reductase.

    PubMed

    Kratzer, Regina; Wilson, David K; Nidetzky, Bernd

    2006-09-01

    Aldo-keto reductases (AKRs) constitute a large protein superfamily of mainly NAD(P)-dependent oxidoreductases involved in carbonyl metabolism. Catalysis is promoted by a conserved tetrad of active site residues (Tyr, Lys, Asp and His). Recent results of structure-function relationship studies for xylose reductase (AKR2B5) require an update of the proposed catalytic mechanism. Electrostatic stabilization by the epsilon-NH3+ group of Lys is a key source of catalytic power of xylose reductase. A molecular-level analysis of the substrate binding pocket of xylose reductase provides a case of how a very broadly specific AKR achieves the requisite selectivity for its physiological substrate and could serve as the basis for the design of novel reductases with improved specificities for biocatalytic applications.

  2. Quality evaluation of the Finasteride polymorphic forms I and II in capsules.

    PubMed

    da Silva, Lucélia Magalhães; Montanari, Cristina Martiniano; Santos, Olimpia Maria Martins; Cazedey, Edith Cristina Laignier; Ângelo, Marilene Lopes; de Araújo, Magali Benjamin

    2015-02-01

    Finasteride (FNS) is a specific competitive inhibitor of steroid type-II 5α-reductase and is widely used for the treatment of benign prostatic hyperplasia, prostate cancer, and androgenetic alopecia. FNS has two polymorphic forms identified as Form I and Form II. It is known that polymorphism can cause significant differences in the physicochemical properties of a compound such as melting point, density, morphology, solubility, and color. Thus, proper qualitative and quantitative monitoring of the solid-state forms is crucial to ensure high-quality products. There are no published papers studying the influence of the FNS polymorphs on the physicochemical quality of capsules. Furthermore, the available analytical methods are time-consuming, expensive, use buffer or do not demonstrate stability-indicating capacity. The aim of this work was to validate a rapid high-performance liquid chromatography (HPLC) method to evaluate FNS in capsules and to study the physicochemical properties of polymorphic forms, evaluating their possible influence in the dissolution profile and stability of FNS in capsules. Capsules containing Forms I and II of FNS were prepared and subjected to quality control studies, dissolution profiles and a stability study at 50°C. A significant effect of polymorphism on the FNS solubility and dissolution properties was observed. These results suggest that changes in the effects of FNS can occur if a suitable control study is not performed on the raw material used to produce the capsules.

  3. Methionine Sulfoxide Reductases Are Essential for Virulence of Salmonella Typhimurium

    PubMed Central

    Rouf, Syed Fazle; Kitowski, Vera; Böhm, Oliver M.; Rhen, Mikael; Jäger, Timo; Bange, Franz-Christoph

    2011-01-01

    Production of reactive oxygen species represents a fundamental innate defense against microbes in a diversity of host organisms. Oxidative stress, amongst others, converts peptidyl and free methionine to a mixture of methionine-S- (Met-S-SO) and methionine-R-sulfoxides (Met-R-SO). To cope with such oxidative damage, methionine sulfoxide reductases MsrA and MsrB are known to reduce MetSOs, the former being specific for the S-form and the latter being specific for the R-form. However, at present the role of methionine sulfoxide reductases in the pathogenesis of intracellular bacterial pathogens has not been fully detailed. Here we show that deletion of msrA in the facultative intracellular pathogen Salmonella (S.) enterica serovar Typhimurium increased susceptibility to exogenous H2O2, and reduced bacterial replication inside activated macrophages, and in mice. In contrast, a ΔmsrB mutant showed the wild type phenotype. Recombinant MsrA was active against free and peptidyl Met-S-SO, whereas recombinant MsrB was only weakly active and specific for peptidyl Met-R-SO. This raised the question of whether an additional Met-R-SO reductase could play a role in the oxidative stress response of S. Typhimurium. MsrC is a methionine sulfoxide reductase previously shown to be specific for free Met-R-SO in Escherichia (E.) coli. We tested a ΔmsrC single mutant and a ΔmsrBΔmsrC double mutant under various stress conditions, and found that MsrC is essential for survival of S. Typhimurium following exposure to H2O2, as well as for growth in macrophages, and in mice. Hence, this study demonstrates that all three methionine sulfoxide reductases, MsrA, MsrB and MsrC, facilitate growth of a canonical intracellular pathogen during infection. Interestingly MsrC is specific for the repair of free methionine sulfoxide, pointing to an important role of this pathway in the oxidative stress response of Salmonella Typhimurium. PMID:22073230

  4. Polymorphism of phosphoric oxide

    USGS Publications Warehouse

    Hill, W.L.; Faust, G.T.; Hendricks, S.B.

    1943-01-01

    The melting points and monotropic relationship of three crystalline forms of phosphoric oxide were determined by the method of quenching. Previous vapor pressure data are discussed and interpreted to establish a pressure-temperature diagram (70 to 600??) for the one-component system. The system involves three triple points, at which solid, liquid and vapor (P4O10) coexist in equilibrium, namely: 420?? and 360 cm., 562?? and 43.7 cm. and 580?? and 55.5 cm., corresponding to the hexagonal, orthorhombic and stable polymorphs, respectively, and at least two distinct liquids, one a stable polymer of the other, which are identified with the melting of the stable form and the hexagonal modification, respectively. Indices of refraction of the polymorphs and glasses were determined. The density and the thermal, hygroscopic and structural properties of the several phases are discussed.

  5. Kinetic characteristics of ZENECA ZD5522, a potent inhibitor of human and bovine lens aldose reductase.

    PubMed

    Cook, P N; Ward, W H; Petrash, J M; Mirrlees, D J; Sennitt, C M; Carey, F; Preston, J; Brittain, D R; Tuffin, D P; Howe, R

    1995-04-18

    Aldose reductase (aldehyde reductase 2) catalyses the conversion of glucose to sorbitol, and methylglyoxal to acetol. Treatment with aldose reductase inhibitors (ARIs) is a potential approach to decrease the development of diabetic complications. The sulphonylnitromethanes are a recently discovered class of aldose reductase inhibitors, first exemplified by ICI215918. We now describe enzyme kinetic characterization of a second sulphonylnitromethane, 3',5'-dimethyl-4'-nitromethylsulphonyl-2-(2-tolyl)acetanilide (ZD5522), which is at least 10-fold more potent against bovine lens aldose reductase in vitro and which also has a greater efficacy for reduction of rat nerve sorbitol levels in vivo (ED95 = 2.8 mg kg-1 for ZD5522 and 20 mg kg-1 for ICI 215918). ZD5522 follows pure noncompetitive kinetics against bovine lens aldose reductase when either glucose or methylglyoxal is varied (K(is) = K(ii) = 7.2 and 4.3 nM, respectively). This contrasts with ICI 215918 which is an uncompetitive inhibitor (K(ii) = 100 nM) of bovine lens aldose reductase when glucose is varied. Against human recombinant aldose reductase, ZD5522 displays mixed noncompetitive kinetics with respect to both substrates (K(is) = 41 nM, K(ii) = 8 nM with glucose and K(is) = 52 nM, K(ii) = 3.8 nM with methylglyoxal). This is the first report of the effects of a sulphonylnitromethane on either human aldose reductase or utilization of methylglyoxal. These results are discussed with reference to a Di Iso Ordered Bi Bi mechanism for aldose reductase, where the inhibitors compete with binding of both the aldehyde substrate and alcohol product. This model may explain why aldose reductase inhibitors follow noncompetitive or uncompetitive kinetics with respect to aldehyde substrates, and X-ray crystallography paradoxically locates an ARI within the substrate binding site. Aldehyde reductase (aldehyde reductase 1) is closely related to aldose reductase. Inhibition of bovine kidney aldehyde reductase by ZD5522

  6. Screening of Israeli Holstein-Friesian cattle for restriction fragment length polymorphisms using homologous and heterologous deoxyribonucleic acid probes.

    PubMed

    Hallerman, E M; Nave, A; Soller, M; Beckmann, J S

    1988-12-01

    Genomic DNA of Israeli Holstein-Friesian dairy cattle were screened with a battery of 17 cloned or subcloned DNA probes in an attempt to document restriction fragment length polymorphisms at a number of genetic loci. Restriction fragment length polymorphisms were observed at the chymosin, oxytocin-neurophysin I, lutropin beta, keratin III, keratin VI, keratin VII, prolactin, and dihydrofolate reductase loci. Use of certain genomic DNA fragments as probes produced hybridization patterns indicative of satellite DNA at the respective loci. Means for distinguishing hybridizations to coding sequences for unique genes from those to satellite DNA were developed. Results of this study are discussed in terms of strategy for the systematic development of large numbers of bovine genomic polymorphisms.

  7. Regulation of Nitrate Reductase Activity in Corn (Zea mays L.) Seedlings by Endogenous Metabolites 1

    PubMed Central

    Schrader, L. E.; Hageman, R. H.

    1967-01-01

    Primary and secondary metabolites of inorganic nitrogen metabolism were evaluated as inhibitors of nitrate reductase (EC 1.6.6.1) induction in green leaf tissue of corn seedlings. Nitrite, nitropropionic acid, ammonium ions, and amino acids were not effective as inhibitors of nitrate reductase activity or synthesis. Increasing α-amino nitrogen and protein content of intact corn seedlings by culture techniques significantly enhanced rather than decreased the potential for induction of nitrate reductase activity in excised seedlings. Secondary metabolites, derived from phenylalanine and tyrosine, were tested as inhibitors of induction of nitrate reductase. Of the 9 different phenylpropanoid compounds tested, only coumarin, trans-cinnamic and trans-o-hydroxycinnamic acids inhibited induction of nitrate reductase. While coumarin alone exhibited a relatively greater inhibitory effect on enzyme induction than on general protein synthesis (the latter measured by incorporation of labeled amino acids), this differential effect may have been dependent upon unequal rates of synthesis and accumulation with respect to the initial levels of nitrate reductase and general proteins. Because of the short half-life of nitrate reductase, inhibitors of protein synthesis in general could still achieve differential regulation of nitrogen metabolism. Coumarin did not inhibit nitrate reductase activity when added directly to the assay mixture at 5 mm. Carbamyl phosphate and its chemical derivative, cyanate, were found to be competitive (with nitrate) inhibitors of nitrate reductase. The data suggest that cyanate is the active inhibitor in the carbamyl phosphate preparations. PMID:16656715

  8. A flavone from Manilkara indica as a specific inhibitor against aldose reductase in vitro.

    PubMed

    Haraguchi, Hiroyuki; Hayashi, Ryosuke; Ishizu, Takashi; Yagi, Akira

    2003-09-01

    Isoaffinetin (5,7,3',4',5'-pentahydroxyflavone-6-C-glucoside) was isolated from Manilkara indica as a potent inhibitor of lens aldose reductase by bioassay-directed fractionation. This C-glucosyl flavone showed specific inhibition against aldose reductases (rat lens, porcine lens and recombinant human) with no inhibition against aldehyde reductase and NADH oxidase. Kinetic analysis showed that isoaffinetin exhibited uncompetitive inhibition against both dl-glyceraldehyde and NADPH. A structure-activity relationship study revealed that the increasing number of hydroxy groups in the B-ring contributes to the increase in aldose reductase inhibition by C-glucosyl flavones.

  9. Ammonification in Bacillus subtilis Utilizing Dissimilatory Nitrite Reductase Is Dependent on resDE

    PubMed Central

    Hoffmann, Tamara; Frankenberg, Nicole; Marino, Marco; Jahn, Dieter

    1998-01-01

    During anaerobic nitrate respiration Bacillus subtilis reduces nitrate via nitrite to ammonia. No denitrification products were observed. B. subtilis wild-type cells and a nitrate reductase mutant grew anaerobically with nitrite as an electron acceptor. Oxygen-sensitive dissimilatory nitrite reductase activity was demonstrated in cell extracts prepared from both strains with benzyl viologen as an electron donor and nitrite as an electron acceptor. The anaerobic expression of the discovered nitrite reductase activity was dependent on the regulatory system encoded by resDE. Mutation of the gene encoding the regulatory Fnr had no negative effect on dissimilatory nitrite reductase formation. PMID:9422613

  10. Structure of the Molybdenum Site of EEcherichia Coli Trimethylamine N-Oxide Reductase

    SciTech Connect

    Zhang, L.; Nelson, K.Johnson; Rajagopalan, K.V.; George, G.N.

    2009-05-28

    We report a structural characterization of the molybdenum site of recombinant Escherichia coli trimethylamine N-oxide (TMAO) reductase using X-ray absorption spectroscopy. The enzyme active site shows considerable similarity to that of dimethyl sulfoxide (DMSO) reductase, in that, like DMSO reductase, the TMAO reductase active site can exist in multiple forms. Examination of the published crystal structure of TMAO oxidase from Shewanella massilia indicates that the postulated Mo coordination structure is chemically impossible. The presence of multiple active site structures provides a potential explanation for the anomalous features reported from the crystal structure.

  11. Stability of Polymeric Crystalline Polymorphs

    NASA Astrophysics Data System (ADS)

    Sinkovits, Daniel W.; Kumar, Sanat K.

    2014-03-01

    In the search for polymeric materials with novel properties, such as high dielectric constant and low loss, an important attribute of a material is its crystal structure. Most polymers can crystallize into multiple polymorphs whose properties vary. Therefore, the question of which polymorphs are thermodynamically preferred under what conditions is of great importance. We generate polymorphs using atomistic molecular dynamics simulations and tackle the question of stability using a combination of molecular dynamics and Monte Carlo techniques. Multidisciplinary University Research Initiative (MURI).

  12. Components of glycine reductase from Eubacterium acidaminophilum. Cloning, sequencing and identification of the genes for thioredoxin reductase, thioredoxin and selenoprotein PA.

    PubMed

    Lübbers, M; Andreesen, J R

    1993-10-15

    The genes encoding thioredoxin reductase (trxB), thioredoxin (trxA), protein PA of glycine reductase (grdA) and the first 23 amino acids of the large subunit of protein PC of glycine reductase (grdC) belonging to the reductive deamination systems present in Eubacterium acidaminophilum were cloned and sequenced. The proteins were products of closely linked genes with 314 codons (thioredoxin reductase), 110 codons (thioredoxin), and 158 codons (protein PA). The protein previously called 'atypically small lipoamide dehydrogenase' or 'electron transferring flavoprotein' could now conclusively be identified as a thioredoxin reductase (subunit mass of 34781 Da) by the alignment with the enzyme of Escherichia coli showing the same typical order of the corresponding domains. The thioredoxin (molecular mass of 11742 Da) deviated considerably from the known consensus sequence, even in the most strongly conserved redox-active segment WCGPC that was now GCVPC. The selenocysteine of protein PA (molecular mass of 16609 Da) was encoded by TGA. The protein was highly similar to those of Clostridium purinolyticum and Clostridium sticklandii involved in glycine reductase. Thioredoxin reductase and thioredoxin of E. acidaminophilum could be successfully expressed in E. coli.

  13. Structural and Biochemical Characterization of Cinnamoyl-CoA Reductases.

    PubMed

    Sattler, Steven A; Walker, Alexander M; Vermerris, Wilfred; Sattler, Scott E; Kang, ChulHee

    2017-02-01

    Cinnamoyl-coenzyme A reductase (CCR) catalyzes the reduction of hydroxycinnamoyl-coenzyme A (CoA) esters using NADPH to produce hydroxycinnamyl aldehyde precursors in lignin synthesis. The catalytic mechanism and substrate specificity of cinnamoyl-CoA reductases from sorghum (Sorghum bicolor), a strategic plant for bioenergy production, were deduced from crystal structures, site-directed mutagenesis, and kinetic and thermodynamic analyses. Although SbCCR1 displayed higher affinity for caffeoyl-CoA or p-coumaroyl-CoA than for feruloyl-CoA, the enzyme showed significantly higher activity for the latter substrate. Through molecular docking and comparisons between the crystal structures of the Vitis vinifera dihydroflavonol reductase and SbCCR1, residues threonine-154 and tyrosine-310 were pinpointed as being involved in binding CoA-conjugated phenylpropanoids. Threonine-154 of SbCCR1 and other CCRs likely confers strong substrate specificity for feruloyl-CoA over other cinnamoyl-CoA thioesters, and the T154Y mutation in SbCCR1 led to broader substrate specificity and faster turnover. Through data mining using our structural and biochemical information, four additional putative CCR genes were discovered from sorghum genomic data. One of these, SbCCR2, displayed greater activity toward p-coumaroyl-CoA than did SbCCR1, which could imply a role in the synthesis of defense-related lignin. Taken together, these findings provide knowledge about critical residues and substrate preference among CCRs and provide, to our knowledge, the first three-dimensional structure information for a CCR from a monocot species.

  14. Thioredoxin Glutathione Reductase-Dependent Redox Networks in Platyhelminth Parasites

    PubMed Central

    Bonilla, Mariana; Gladyshev, Vadim N.

    2013-01-01

    Abstract Significance: Platyhelminth parasites cause chronic infections that are a major cause of disability, mortality, and economic losses in developing countries. Maintaining redox homeostasis is a major adaptive problem faced by parasites and its disruption can shift the biochemical balance toward the host. Platyhelminth parasites possess a streamlined thiol-based redox system in which a single enzyme, thioredoxin glutathione reductase (TGR), a fusion of a glutaredoxin (Grx) domain to canonical thioredoxin reductase (TR) domains, supplies electrons to oxidized glutathione (GSSG) and thioredoxin (Trx). TGR has been validated as a drug target for schistosomiasis. Recent Advances: In addition to glutathione (GSH) and Trx reduction, TGR supports GSH-independent deglutathionylation conferring an additional advantage to the TGR redox array. Biochemical and structural studies have shown that the TR activity does not require the Grx domain, while the glutathione reductase and deglutathionylase activities depend on the Grx domain, which receives electrons from the TR domains. The search for TGR inhibitors has identified promising drug leads, notably oxadiazole N-oxides. Critical Issues: A conspicuous feature of platyhelminth TGRs is that their Grx-dependent activities are temporarily inhibited at high GSSG concentrations. The mechanism underlying the phenomenon and its biological relevance are not completely understood. Future Directions: The functional diversity of Trxs and Grxs encoded in platyhelminth genomes remains to be further assessed to thoroughly understand the TGR-dependent redox network. Optimization of TGR inhibitors and identification of compounds targeting other parasite redox enzymes are good options to clinically develop relevant drugs for these neglected, but important diseases. Antioxid. Redox Signal. 19, 735–745. PMID:22909029

  15. Cytochrome b5 and NADH cytochrome b5 reductase: genotype-phenotype correlations for hydroxylamine reduction

    PubMed Central

    Sacco, James C.; Trepanier, Lauren A.

    2010-01-01

    Objectives NADH cytochrome b5 reductase (b5R) and cytochrome b5 (b5) catalyze the reduction of sulfamethoxazole hydroxylamine (SMX-HA), which can contribute to sulfonamide hypersensitivity, to the parent drug sulfamethoxazole. Variability in hydroxylamine reduction could thus play a role in adverse drug reactions. The aim of this study was to characterize variability in SMX-HA reduction in 111 human livers, and investigate its association with single nucleotide polymorphisms (SNPs) in b5 and b5R cDNA. Methods Liver microsomes were assayed for SMX-HA reduction activity, and b5 and b5R expression was semi-quantified by immunoblotting. The coding regions of the b5 (CYB5A) and b5R (CYB5R3) genes were resequenced. Results Hepatic SMX-HA reduction displayed a 19-fold range of individual variability (0.06–1.11 nmol/min/mg protein), and a 17-fold range in efficiency (Vmax/Km) among outliers. SMX-HA reduction was positively correlated with b5 and b5R protein content (p < 0.0001, r = 0.42; p = 0.01, r = 0.23, respectively), and expression of both proteins correlated with one another (p < 0.0001; r = 0.74). A novel cSNP in CYB5A (S5A) was associated with very low activity and protein expression. Two novel CYB5R3 SNPs, R59H and R297H, displayed atypical SMX-HA reduction kinetics and decreased SMX-HA reduction efficiency. Conclusion These studies indicate that while novel cSNPs in CYB5A and CYB5R3 are associated with significantly altered protein expression and/or hydroxylamine reduction activities, these low frequency cSNPs only appear to minimally impact overall observed phenotypic variability. Work is underway to characterize polymorphisms in other regions of these genes to further account for individual variability in hydroxylamine reduction. PMID:19997042

  16. The nitrate reductase-encoding gene of Volvox carteri: map location, sequence and induction kinetics.

    PubMed

    Gruber, H; Goetinck, S D; Kirk, D L; Schmitt, R

    1992-10-12

    The nitrate reductase (NR) structural gene (nitA) of Volvox carteri has been cloned and characterized. There is a single copy of this gene in the genome, and RFLP (restriction-fragment length polymorphism) analysis assigns it to the previously defined nitA/chlR locus on linkage group IX, 20-30 cM from the two beta-tubulin-encoding loci. Determination of the 5871-nt sequence of the coding region of genomic clones, and comparisons to a cDNA sequence, revealed ten introns and eleven exons that encode a 864-aa polypeptide. Detailed comparisons with higher-plant and fungal NRs indicate that, whereas the aa sequence is strongly conserved within functional domains for the flavin adenine dinucleotide-, heme- and molybdenum-pterin cofactor-binding sites, substantial differences in the aa sequence occur in the N-terminal end and the two inter-domain regions. Two potential transcription start points 439 and 452 nt upstream from the start codon and a polyadenylation signal 355 nt downstream from the stop codon have been identified by primer-extension analysis and cDNA sequencing, respectively. Accumulation of the nitA transcript is both induced by nitrate and repressed by ammonium and urea: after the organism is transferred from ammonium to nitrate as the nitrogen source, a 3.6-kb NR transcript is readily detectable on Northern blots by 10 min, reaches maximum abundance by 30 min, and then rapidly declines to an intermediate level that is subsequently maintained. Substantial induction by nitrate is observed at the end of the dark portion of the daily light/dark cycle, but the inductive response peaks in the first hour of the light period.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Phylogenetic diversity of dissimilatory sulfite reductase genes from deep-sea cold seep sediment.

    PubMed

    Fukuba, Tatsuhiro; Ogawa, Mari; Fujii, Teruo; Naganuma, Takeshi

    2003-01-01

    The phylogenetic diversity of dissimilatory sulfite reductase (DSR, EC 1.8.99.3) alpha-subunit genes from a deep-sea cold seep was analyzed. Bulk genomic DNA was extracted from the cold seep sediment and used for amplification by polymerase chain reaction (PCR) of DSR alpha-subunit gene. Two sizes of PCR products, 1.4 kb (expected) and 1.3 kb (unexpected), were amplified. Sixteen clones of the 1.4-kb amplicons and 16 clones of 1.3-kb amplicons, a total of 32 clones, were obtained and grouped into operational DSR units (ODUs) based on restriction fragment length polymorphism (RFLP) by digestion with HaeIII and MboI. A total of 14 ODUs, i.e., 5 ODUs from 1.4-kb amplicon clones and 9 ODUs from 1.3-kb amplicon clones, were recovered. About 400 bp of the 5' ends of all the clones was sequenced and validated the RFLP-based ODU grouping. All the 5'-end 400-bp sequences of ODUs, even from the 1.3-kb amplicons, showed the characteristic DSR amino acid sequence motifs. The ODUs from 1.4-kb amplicons were closely related to the delta-Proteobacterial lineage with the DSR genes from epsilon-Proteobacterial epibionts of the hot vent worm Alvinella pompejana. The ODUs from 1.3-kb amplicons were mostly related to the unknown but possibly archaeal lineage. The diversity of the DSR genes may indicate the diversity of sulfate reducers in the seep sediment as well as the complexity of electron donors including methane.

  18. Terpenoids from Diplophyllum taxifolium with quinone reductase-inducing activity.

    PubMed

    Wang, Xiao; Zhang, Jiao-Zhen; Zhou, Jin-Chuan; Shen, Tao; Lou, Hong-Xiang

    2016-03-01

    Two new ent-prenylaromadendrane-type diterpenoids, diplotaxifols A (1) and B (2), a new ent-eudesmol, ent-eudesma-4(15),11(13)-dien-6α,12-diol (3), eight new eudesmanolides enantiomers (4-11) of the corresponding compounds from higher plants along with four known ent-eudesmanolides (12-15) were isolated from the 95% EtOH extract of Chinese liverwort Diplophyllum taxifolium. Their structures were elucidated on the basis of MS, NMR and IR spectral data, and confirmed by single-crystal X-ray diffraction analysis. The quinone reductase-inducing activity of the compounds was evaluated.

  19. Applications of Carboxylic Acid Reductases in Oleaginous Microbes

    SciTech Connect

    Resch, Michael G.; Linger, Jeffrey; McGeehan, John; Tyo, Keith; Beckham, Gregg

    2016-04-24

    Carboxylic acid reductases (CARs) are recently emerging reductive enzymes for the direct production of aldehydes from biologically-produced carboxylic acids. Recent work has demonstrated that these powerful enzymes are able to reduce a very broad range of volatile- to long-chain fatty acids as well as aromatic acids. Here, we express four CAR enzymes from different fungal origins to test their activity against fatty acids commonly produced in oleaginous microbes. These in vitro results will inform metabolic engineering strategies to conduct mild biological reduction of carboxylic acids in situ, which is conventionally done via hydrotreating catalysis at high temperatures and hydrogen pressures.

  20. A Novel NADPH-dependent flavoprotein reductase from Bacillus megaterium acts as an efficient cytochrome P450 reductase.

    PubMed

    Milhim, Mohammed; Gerber, Adrian; Neunzig, Jens; Hannemann, Frank; Bernhardt, Rita

    2016-08-10

    Cytochromes P450 (P450s) require electron transfer partners to catalyze substrate conversions. With regard to biotechnological approaches, the elucidation of novel electron transfer proteins is of special interest, as they can influence the enzymatic activity and specificity of the P450s. In the current work we present the identification and characterization of a novel soluble NADPH-dependent diflavin reductase from Bacillus megaterium with activity towards a bacterial (CYP106A1) and a microsomal (CYP21A2) P450 and, therefore, we referred to it as B. megaterium cytochrome P450 reductase (BmCPR). Sequence analysis of the protein revealed besides the conserved FMN-, FAD- and NADPH-binding motifs, the presence of negatively charged cluster, which is thought to represent the interaction domain with P450s and/or cytochrome c. BmCPR was expressed and purified to homogeneity in Escherichia coli. The purified BmCPR exhibited a characteristic diflavin reductase spectrum, and showed a cytochrome c reducing activity. Furthermore, in an in vitro reconstituted system, the BmCPR was able to support the hydroxylation of testosterone and progesterone with CYP106A1 and CYP21A2, respectively. Moreover, in view of the biotechnological application, the BmCPR is very promising, as it could be successfully utilized to establish CYP106A1- and CYP21A2-based whole-cell biotransformation systems, which yielded 0.3g/L hydroxy-testosterone products within 8h and 0.16g/L 21-hydroxyprogesterone within 6h, respectively. In conclusion, the BmCPR reported herein owns a great potential for further applications and studies and should be taken into consideration for bacterial and/or microsomal CYP-dependent bioconversions.

  1. Energetics of kaolin polymorphs

    SciTech Connect

    Ligny, D. de; Navrotsky, A.

    1999-04-01

    The enthalpy of formation of kaolin polymorphs at 298 K has been determined by drop-solution calorimetry into molten lead borate at 975 K. Corrections have been made for impurities in the samples. The standard enthalpy of formation from the elements is: kaolinite {minus}4120.2 {+-} 6.6 kJ/mol, dickite {minus}4107.6 {+-} 5.7 kJ/mol, nacrite {minus}4104.0 {+-} 7.6 kJ/mol, and halloysite {minus}4097.5 {+-} 5.6 kJ/mol. Using entropy data from the literature, the standard free energy of formation from the elements at 298 K is /{minus}3799.4 {+-} 6.4 kJ/mol for kaolinite, {minus}3785.1 {+-} 5.6 kJ/mol for dickite, and {minus}3776.8 {+-} 5.8 kJ/mol for halloysite. The effect of crystallinity (Hinckley index ranging from 1.6 to 0.4) on the enthalpy of formation of kaolinite is smaller than 5 kJ/mol, the experimental error. The relative stability of the polymorphs probably does not change significantly with pressure and temperature over their range of occurrence. Thus the geological occurrence of halloysite, nacrite, and dickite, which are metastable phases, must be interpreted in terms of kinetics or as the result of a specific synthesis path, rather than as resulting from changes in the thermodynamically stable phase assemblage.

  2. Aldose Reductase-catalyzed Reduction of Aldehyde Phospholipids

    PubMed Central

    Srivastava, Sanjay; Spite, Matthew; Trent, John O.; West, Matthew B.; Ahmed, Yonis; Bhatnagar, Aruni

    2012-01-01

    SUMMARY Oxidation of unsaturated phospholipids results in the generation of aldehyde side chains that remain esterified to the phospholipid backbone. Such “core” aldehydes elicit immune responses and promote inflammation. However, the biochemical mechanisms by which phospholipid aldehydes are metabolized or detoxified are not well understood. In the studies reported here, we examined whether aldose reductase (AR), which reduces hydrophobic aldehydes, metabolizes phospholipid aldehydes. Incubation with AR led to the reduction of 5-oxovaleroyl, 7-oxo-5-heptenoyl, 5-hydroxy-6-oxo-caproyl, and 5-hydroxy-8-oxo-6-octenoyl phospholipids generated upon oxidation of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (PAPC). The enzyme also catalyzed the reduction of phospholipid aldehydes generated from the oxidation of 1-alkyl, and 1-alkenyl analogs of PAPC, and 1-palmitoyl-2-arachidonoyl phosphatidic acid or phosphoglycerol. Aldose reductase catalyzed the reduction of chemically synthesized 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphatidylcholine (POVPC) with a Km of 10 μM. Addition of POVPC to the culture medium led to incorporation and reduction of the aldehyde in COS-7 and THP-1 cells. Reduction of POVPC in these cells was prevented by the AR inhibitors sorbinil and tolrestat and was increased in COS-7 cells overexpressing AR. Together, these observations suggest that AR may be a significant participant in the metabolism of several structurally diverse phospholipid aldehydes. This metabolism may be a critical regulator of the pro-inflammatory and immunogenic effects of oxidized phospholipids. PMID:15465833

  3. Two fatty acyl reductases involved in moth pheromone biosynthesis

    PubMed Central

    Antony, Binu; Ding, Bao-Jian; Moto, Ken’Ichi; Aldosari, Saleh A.; Aldawood, Abdulrahman S.

    2016-01-01

    Fatty acyl reductases (FARs) constitute an evolutionarily conserved gene family found in all kingdoms of life. Members of the FAR gene family play diverse roles, including seed oil synthesis, insect pheromone biosynthesis, and mammalian wax biosynthesis. In insects, FAR genes dedicated to sex pheromone biosynthesis (pheromone-gland-specific fatty acyl reductase, pgFAR) form a unique clade that exhibits substantial modifications in gene structure and possesses unique specificity and selectivity for fatty acyl substrates. Highly selective and semi-selective ‘single pgFARs’ produce single and multicomponent pheromone signals in bombycid, pyralid, yponomeutid and noctuid moths. An intriguing question is how a ‘single reductase’ can direct the synthesis of several fatty alcohols of various chain lengths and isomeric forms. Here, we report two active pgFARs in the pheromone gland of Spodoptera, namely a semi-selective, C14:acyl-specific pgFAR and a highly selective, C16:acyl-specific pgFAR, and demonstrate that these pgFARs play a pivotal role in the formation of species-specific signals, a finding that is strongly supported by functional gene expression data. The study envisages a new area of research for disclosing evolutionary changes associated with C14- and C16-specific FARs in moth pheromone biosynthesis. PMID:27427355

  4. Human Neuroglobin Functions as a Redox-regulated Nitrite Reductase*

    PubMed Central

    Tiso, Mauro; Tejero, Jesús; Basu, Swati; Azarov, Ivan; Wang, Xunde; Simplaceanu, Virgil; Frizzell, Sheila; Jayaraman, Thottala; Geary, Lisa; Shapiro, Calli; Ho, Chien; Shiva, Sruti; Kim-Shapiro, Daniel B.; Gladwin, Mark T.

    2011-01-01

    Neuroglobin is a highly conserved hemoprotein of uncertain physiological function that evolved from a common ancestor to hemoglobin and myoglobin. It possesses a six-coordinate heme geometry with proximal and distal histidines directly bound to the heme iron, although coordination of the sixth ligand is reversible. We show that deoxygenated human neuroglobin reacts with nitrite to form nitric oxide (NO). This reaction is regulated by redox-sensitive surface thiols, cysteine 55 and 46, which regulate the fraction of the five-coordinated heme, nitrite binding, and NO formation. Replacement of the distal histidine by leucine or glutamine leads to a stable five-coordinated geometry; these neuroglobin mutants reduce nitrite to NO ∼2000 times faster than the wild type, whereas mutation of either Cys-55 or Cys-46 to alanine stabilizes the six-coordinate structure and slows the reaction. Using lentivirus expression systems, we show that the nitrite reductase activity of neuroglobin inhibits cellular respiration via NO binding to cytochrome c oxidase and confirm that the six-to-five-coordinate status of neuroglobin regulates intracellular hypoxic NO-signaling pathways. These studies suggest that neuroglobin may function as a physiological oxidative stress sensor and a post-translationally redox-regulated nitrite reductase that generates NO under six-to-five-coordinate heme pocket control. We hypothesize that the six-coordinate heme globin superfamily may subserve a function as primordial hypoxic and redox-regulated NO-signaling proteins. PMID:21296891

  5. A mutant of barley lacking NADH-hydroxypyruvate reductase

    SciTech Connect

    Blackwell, R.; Lea, P. )

    1989-04-01

    A mutant of barley, LaPr 88/29, deficient in peroxisomal NADH-hydroxypyruvate reductase (HPR) activity has been identified. Compared to the wild type the activities of NADH-HPR and NADPH-HPR were severely reduced but the mutant was still capable of fixing CO{sub 2} at rates equivalent to 75% of that of the wild type in air. Although lacking an enzyme in the main photorespiratory pathway, there appeared to be little disruption to photorespiratory metabolism as ammonia release, CO{sub 2} efflux and {sup 14}CO{sub 2} release from L-(U-{sup 14}C) serine were similar in both mutant and wild type. LaPr 88/29 has been used to show that NADH-glyoxylate reductase (GR) and NADH-HPR are probably not catalyzed by the same enzyme in barley and that over 80% of the NADPH-HPR activity is due to the NADH-HPR enzyme. Immunological studies, using antibodies raised against spinach HPR, have shown that the NADH-dependent enzyme protein is absent in LaPr 88/29 but there appears to be enhanced synthesis of the NADPH-dependent enzyme protein.

  6. Fluorescent analogues of methotrexate: characterization and interaction with dihydrofolate reductase.

    PubMed

    Kumar, A A; Kempton, R J; Anstead, G M; Freisheim, J H

    1983-01-18

    The dansylated derivatives of lysine and ornithine analogues of methotrexate exhibit fluorescence properties characteristic of the dansyl moiety with an excitation at 328 nm and an emission maximum at 580 nm in aqueous media. As in the case of dansyl amino acids, the fluorescence emission is dependent upon the polarity of the medium. In solvents of low dielectric constant there is an enhancement of the dansyl fluorescence intensity as well as a shift to shorter wavelengths. The dansylated analogues show a reduction in the quantum yields as compared to N epsilon-dansyl-L-lysine and 5-(N,N-dimethylamino)-1-naphthalenesulfonic acid. The absorption spectra of the two dansyl analogues are similar to the spectra of the parent basic amino acid precursors but with reduced molar extinction values. The two fluorescent analogues of methotrexate were found to be potent inhibitors of purified dihydrofolate reductases from Lactobacillus casei and from chicken liver. The binding of these fluorescent analogues to either dihydrofolate reductase resulted in 10-15-nm blue shift of the ligand emission maxima and a 2-5-fold enhancement of the emission. These fluorescent properties of the bound ligands indicate a possible interaction of the dansyl moiety with a region on the enzyme molecule which is more hydrophobic relative to the surrounding solvent.

  7. ADP-ribosylation of dinitrogenase reductase in Rhodobacter capsulatus

    SciTech Connect

    Jouanneau, Y.; Roby, C.; Meyer, C.M.; Vignais, P.M. )

    1989-07-25

    In the photosynthetic bacterium Rhodobacter capsulatus, nitrogenase is regulated by a reversible covalent modification of Fe protein or dinitrogenase reductase (Rc2). The linkage of the modifying group to inactive Rc2 was found to be sensitive to alkali and to neutral hydroxylamine. Complete release of the modifying group was achieved by incubation of inactive Rc2 in 0.4 or 1 M hydroxylamine. After hydroxylamine treatment of the Rc2 preparation, the modifying group could be isolated and purified by affinity chromatography and ion-exchange HPLC. The modifying group comigrated with ADP-ribose on both ion-exchange HPLC and thin-layer chromatography. Analyses by {sup 31}P NMR spectroscopy and mass spectrometry provided further evidence that the modifying group was ADP-ribose. The NMR spectrum of inactive Rc2 exhibited signals characteristic of ADP-ribose; integration of these signals allowed calculation of a molar ration ADP-ribose/Rc2 of 0.63. A hexapeptide carrying the ADP-ribose moiety was purified from a subtilisin digest of inactive Rc2. The structure of this peptide, determined by amino acid analysis and sequencing, is Gly-Arg(ADP-ribose)-Gly-Val-Ile-Thr. This structure allows identification of the binding site for ADP-ribose as Arg 101 of the polypeptide chain of Rc2. It is concluded that nitrogenase activity in R. capsulatus is regulated by reversible ADP-ribosylation of a specific arginyl residue of dinitrogenase reductase.

  8. Hydroxyurea-resistant vaccinia virus: overproduction of ribonucleotide reductase

    SciTech Connect

    Slabaugh, M.B.; Mathews, C.K.

    1986-11-01

    Repeated passage of vaccinia virus in increasing concentrations of hydroxyurea followed by plaque purification resulted in the isolation of variants capable of growth in 5 mM hydroxyurea, a drug concentration which inhibited the reproduction of wild-type vaccinia virus 1000-fold. Analyses of viral protein synthesis by using (/sup 35/S)methionine pulse-labeling at intervals throughout the infection cycle revealed that all isolates overproduced a 34,000-molecular-weight (MW) early polypeptide. Measurement of ribonucleoside-diphosphate reductase activity after infection indicated that 4- to 10-fold more activity was induced by hydroxyurea-resistant viruses than by the wild-type virus. A two-step partial purification resulted in a substantial enrichment for the 34,000-MW protein from extracts of wild-type and hydroxyurea-resistant-virus-infected, but not mock-infected, cells. In the presence of the drug, the isolates incorporated (/sup 3/H)thymidine into DNA earlier and a rate substantially greater than that of the wild type, although the onset of DNA synthesis was delayed in both cases. The drug resistance trait was markedly unstable in all isolates. In the absence of selective pressure, plaque-purified isolated readily segregated progeny that displayed a wide range of resistance phenotypes. The results of this study indicate that vaccinia virus encodes a subunit of ribonucleotide reductase which is 34,000-MW early protein whose overproduction confers hydroxyurea resistance on reproducing viruses.

  9. Increased nitrite reductase activity of fetal versus adult ovine hemoglobin

    PubMed Central

    Blood, Arlin B.; Tiso, Mauro; Verma, Shilpa T.; Lo, Jennifer; Joshi, Mahesh S.; Azarov, Ivan; Longo, Lawrence D.; Gladwin, Mark T.; Kim-Shapiro, Daniel B.; Power, Gordon G.

    2009-01-01

    Growing evidence indicates that nitrite, NO2−, serves as a circulating reservoir of nitric oxide (NO) bioactivity that is activated during physiological and pathological hypoxia. One of the intravascular mechanisms for nitrite conversion to NO is a chemical nitrite reductase activity of deoxyhemoglobin. The rate of NO production from this reaction is increased when hemoglobin is in the R conformation. Because the mammalian fetus exists in a low-oxygen environment compared with the adult and is exposed to episodes of severe ischemia during the normal birthing process, and because fetal hemoglobin assumes the R conformation more readily than adult hemoglobin, we hypothesized that nitrite reduction to NO may be enhanced in the fetal circulation. We found that the reaction was faster for fetal than maternal hemoglobin or blood and that the reactions were fastest at 50–80% oxygen saturation, consistent with an R-state catalysis that is predominant for fetal hemoglobin. Nitrite concentrations were similar in blood taken from chronically instrumented normoxic ewes and their fetuses but were elevated in response to chronic hypoxia. The findings suggest an augmented nitrite reductase activity of fetal hemoglobin and that the production of nitrite may participate in the regulation of vascular NO homeostasis in the fetus. PMID:19028797

  10. Dimethyl Fumarate Induces Glutathione Recycling by Upregulation of Glutathione Reductase

    PubMed Central

    Hoffmann, Christina; Dietrich, Michael; Herrmann, Ann-Kathrin; Schacht, Teresa

    2017-01-01

    Neuronal degeneration in multiple sclerosis has been linked to oxidative stress. Dimethyl fumarate (DMF) is an effective oral therapeutic option shown to reduce disease activity and progression in patients with relapsing-remitting multiple sclerosis. DMF activates the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) leading to increased synthesis of the major cellular antioxidant glutathione (GSH) and prominent neuroprotection in vitro. We previously demonstrated that DMF is capable of raising GSH levels even when glutathione synthesis is inhibited, suggesting enhanced GSH recycling. Here, we found that DMF indeed induces glutathione reductase (GSR), a homodimeric flavoprotein that catalyzes GSSG reduction to GSH by using NADPH as a reducing cofactor. Knockdown of GSR using a pool of E. coli RNase III-digested siRNAs or pharmacological inhibition of GSR, however, also induced the antioxidant response rendering it impossible to verify the suspected attenuation of DMF-mediated neuroprotection. However, in cystine-free medium, where GSH synthesis is abolished, pharmacological inhibition of GSR drastically reduced the effect of DMF on glutathione recycling. We conclude that DMF increases glutathione recycling through induction of glutathione reductase. PMID:28116039

  11. Nitrate metabolism in tobacco leaves overexpressing Arabidopsis nitrite reductase.

    PubMed

    Davenport, Susie; Le Lay, Pascaline; Sanchez-Tamburrrino, Juan Pablo

    2015-12-01

    Primary nitrogen assimilation in plants includes the reduction of nitrite to ammonium in the chloroplasts by the enzyme nitrite reductase (NiR EC:1.7.7.1) or in the plastids of non-photosynthetic organs. Here we report on a study overexpressing the Arabidopsis thaliana NiR (AtNiR) gene in tobacco plants under the control of a constitutive promoter (CERV - Carnation Etched Ring Virus). The aim was to overexpress AtNiR in an attempt to alter the level of residual nitrite in the leaf which can act as precursor to the formation of nitrosamines. The impact of increasing the activity of AtNiR produced an increase in leaf protein and a stay-green phenotype in the primary transformed AtNiR population. Investigation of the T1 homozygous population demonstrated elevated nitrate reductase (NR) activity, reductions in leaf nitrite and nitrate and the amino acids proline, glutamine and glutamate. Chlorophyl content of the transgenic lines was increased, as evidenced by the stay-green phenotype. This reveals the importance of NiR in primary nitrogen assimilation and how modification of this key enzyme affects both the nitrogen and carbon metabolism of tobacco plants.

  12. Properties of the arsenate reductase of plasmid R773.

    PubMed

    Gladysheva, T B; Oden, K L; Rosen, B P

    1994-06-14

    Resistance to toxic oxyanions in Escherichia coli is conferred by the ars operon carried on plasmid R773. The gene products of this operon catalyze extrusion of antimonials and arsenicals from cells of E. coli, thus providing resistance to those toxic oxyanions. In addition, resistance to arsenate is conferred by the product of the arsC gene. In this report, purified ArsC protein was shown to catalyze reduction of arsenate to arsenite. The enzymatic activity of the ArsC protein required glutaredoxin as a source of reducing equivalents. Other reductants, including glutathione and thioredoxin, were not effective electron donors. A spectrophotometric assay was devised in which arsenate reduction was coupled to NADPH oxidation. The results obtained with the coupled assay corresponded to those found by direct reduction of radioactive arsenate to arsenite. The only substrate of the reaction was arsenate (Km = 8 mM); other oxyanions including phosphate, sulfate, and antimonate were not reduced. Phosphate and sulfate were weak inhibitors, while the product, arsenite, was a stronger inhibitor (Ki = 0.1 mM). Arsenate reductase activity exhibited a pH optimum of 6.3-6.8. These results indicate that the ArsC protein is a novel reductase, and elucidation of its enzymatic mechanism should be of interest.

  13. Homozygous Ala65Pro Mutation with V89L Polymorphism in SRD5A2 Deficiency

    PubMed Central

    Eren, Erdal; Edgünlü, Tuba; Asut, Emre; Karakaş Çelik, Sevim

    2016-01-01

    Objective: Deficiency of steroid 5-alpha reductase type 2 (5αRD2) is a rare autosomal recessive disorder caused by mutations in the SRD5A2 gene. A defect in the 5-alpha reductase enzyme, which ensures conversion of testosterone into dihydrotestosterone, leads to disorders of sex development. This study presents the clinical and genetic results of patients with 5αRD2 deficiency. Methods: 5αRD2 deficiency was detected in 6 different patients from 3 unrelated families. All patients were reared as girls. Two of the patients presented with primary amenorrhea, one with primary amenorrhea and rejection of female gender, and the others with masses in their inguinal canals. Chromosome and sex-determining region Y (SRY) gene analyses were performed in all patients. Additionally, five exons of the SRD5A2 gene were amplified with polymerase chain reaction in the obtained DNA samples and evaluated. Results: While 46,XY was identified in 5 patients, 47,XXY was detected in one patient. The SRY gene was positive in all patients. The p.Ala65Pro (c193G>C) mutation and V89L polymorphism were observed in exon 1 of the SRD5A2 gene in all patients. Conclusion: Identification of this mutation and polymorphism is a significant indicator of presence of 5αRD2 deficiency in Southeastern Turkey, a geographical region where consanguineous marriages are also highly common. PMID:26761946

  14. Sequence and properties of pentaerythritol tetranitrate reductase from Enterobacter cloacae PB2.

    PubMed

    French, C E; Nicklin, S; Bruce, N C

    1996-11-01

    Pentaerythritol tetranitrate reductase, which reductively liberates nitrite from nitrate esters, is related to old yellow enzyme. Pentaerythritol tetranitrate reductase follows a ping-pong mechanism with competitive substrate inhibition by NADPH, is strongly inhibited by steroids, and is capable of reducing the unsaturated bond of 2-cyclohexen-1-one.

  15. Determination of the specific activities of methionine sulfoxide reductase A and B by capillary electrophoresis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A capillary electrophoresis (CE) method for the determination of methionine sulfoxide reductase A and methionine sulfoxide reductase B activities in mouse liver is described. The method is based on detection of the 4-(dimethylamino)azobenzene-4’-sulfonyl derivative of L-methionine (dabsyl Met), the ...

  16. QTL analysis of ferric reductase activity in the model legume lotus japonicus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physiological and molecular studies have demonstrated that iron accumulation from the soil into Strategy I plants can be limited by ferric reductase activity. An initial study of Lotus japonicus ecotypes Miyakojima MG-20 and Gifu B-129 identified significant leaf chlorosis and ferric reductase activ...

  17. Biliverdin Reductase Mediates Hypoxia-Induced EMT via PI3-Kinase and Akt

    PubMed Central

    Zeng, Rui; Yao, Ying; Han, Min; Zhao, Xiaoqin; Liu, Xiao-Cheng; Wei, Juncheng; Luo, Yun; Zhang, Juan; Zhou, Jianfeng; Wang, Shixuan; Ma, Ding; Xu, Gang

    2008-01-01

    Chronic hypoxia in the renal parenchyma is thought to induce epithelial-to-mesenchymal transition (EMT), leading to fibrogenesis and ultimately end-stage renal failure. Biliverdin reductase, recently identified as a serine/threonine/tyrosine kinase that may activate phosphatidylinositol 3-kinase (PI3K) and Akt, is upregulated in response to reactive oxygen species that may accompany hypoxia. We investigated this potential role of biliverdin reductase in hypoxia-induced renal tubular EMT. Expression of biliverdin reductase was upregulated in a human proximal tubule cell line (HK-2) cultured in hypoxic conditions (1% O2), and this was accompanied by reduced expression of E-cadherin and increased expression of the mesenchymal marker vimentin. Inhibiting PI3K reversed these changes, consistent with EMT. In normoxic conditions, overexpression of biliverdin reductase promoted similar characteristics of EMT, which were also reversed by inhibiting PI3K. Furthermore, using small interfering RNA (siRNA) to knockdown biliverdin reductase, we demonstrated that the enzyme associates with phosphorylated Akt and mediates the hypoxia-induced EMT phenotype. In vivo, expression of biliverdin reductase increased in the tubular epithelia of 5/6-nephrectomized rats, and immunohistochemistry of serial sections demonstrated similar localization of phosphorylated Akt and biliverdin reductase. In conclusion, biliverdin reductase mediates hypoxia-induced EMT through a PI3K/Akt-dependent pathway. PMID:18184861

  18. Nitrate transport is independent of NADH and NAD(P)H nitrate reductases in barley seedlings

    NASA Technical Reports Server (NTRS)

    Warner, R. L.; Huffaker, R. C.

    1989-01-01

    Barley (Hordeum vulgare L.) has NADH-specific and NAD(P)H-bispecific nitrate reductase isozymes. Four isogenic lines with different nitrate reductase isozyme combinations were used to determine the role of NADH and NAD(P)H nitrate reductases on nitrate transport and assimilation in barley seedlings. Both nitrate reductase isozymes were induced by nitrate and were required for maximum nitrate assimilation in barley seedlings. Genotypes lacking the NADH isozyme (Az12) or the NAD(P)H isozyme (Az70) assimilated 65 or 85%, respectively, as much nitrate as the wild type. Nitrate assimilation by genotype (Az12;Az70) which is deficient in both nitrate reductases, was only 13% of the wild type indicating that the NADH and NAD(P)H nitrate reductase isozymes are responsible for most of the nitrate reduction in barley seedlings. For all genotypes, nitrate assimilation rates in the dark were about 55% of the rates in light. Hypotheses that nitrate reductase has direct or indirect roles in nitrate uptake were not supported by this study. Induction of nitrate transporters and the kinetics of net nitrate uptake were the same for all four genotypes indicating that neither nitrate reductase isozyme has a direct role in nitrate uptake in barley seedlings.

  19. Comparison of finasteride (Proscar), a 5 alpha reductase inhibitor, and various commercial plant extracts in in vitro and in vivo 5 alpha reductase inhibition.

    PubMed

    Rhodes, L; Primka, R L; Berman, C; Vergult, G; Gabriel, M; Pierre-Malice, M; Gibelin, B

    1993-01-01

    Human prostate was used as a source of 5 alpha reductase. Compounds were incubated with an enzyme preparation and [3H]testosterone. [3H]-dihydrotestosterone production was measured to calculate 5 alpha reductase activity. IC50 values (ng/ml) were finasteride = 1; Permixon = 5,600; Talso = 7,000; Strogen Forte = 31,000; Prostagutt = 40,000; and Tadenan = 63,000. Bazoton and Harzol had no activity at concentrations up to 500,000 ng/ml. In castrate rats stimulated with testosterone (T) or dihydrotestosterone (DHT), finasteride, but not Permixon or Bazoton, inhibited T stimulated prostate growth, while none of the three compounds inhibited DHT stimulated growth. These results demonstrate that finasteride inhibits 5 alpha reductase, while Permixon and Bazoton have neither anti-androgen nor 5 alpha reductase inhibitory activity. In addition, in a 7 day human clinical trial, finasteride, but not Permixon or placebo, decreased serum DHT in men, further confirming the lack of 5 alpha reductase inhibition by Permixon. Finasteride and the plant extracts listed above do not inhibit the binding of DHT to the rat prostatic androgen receptor (concentrations to 100 micrograms/ml). Based on these results, it is unlikely that these plant extracts would shrink the prostate by inhibiting androgen action or 5 alpha reductase.

  20. Isolation of ascorbate free radical reductase from rabbit lens soluble fraction.

    PubMed

    Bando, Masayasu; Inoue, Takashi; Oka, Mikako; Nakamura, Kayako; Kawai, Kenji; Obazawa, Hajime; Kobayashi, Shizuko; Takehana, Makoto

    2004-12-01

    Ascorbate free radical (AFR) reductase with diaphorase activity was isolated from the rabbit lens soluble fraction to characterise some molecular properties of the enzyme. The isolation was accomplished using gel filtration (Sephadex G-75 superfine or Sephacryl S-200 HR), affinity chromatography (Affi-Gel Blue), native isoelectric focusing and two-dimensional gel electrophoresis. A major soluble AFR reductase was found at an isoelectric point of 8.4 and a molecular weight of 31 kDa, and a few minor enzymes were also detected in the range of pI 7.0-8.6. An unknown N-terminal partial amino acid sequence was determined in one peptide fragment prepared from the major enzyme fraction. From the sequence analysis, it is discussed that the lens soluble AFR reductase may differ from NADH-cytochrome b5 reductase reported to be involved in the membrane-bound AFR reductase activity of mitochondria, microsomes and plasma membrane.

  1. Trypanothione Reductase: A Viable Chemotherapeutic Target for Antitrypanosomal and Antileishmanial Drug Design

    PubMed Central

    Khan, M. Omar F.

    2007-01-01

    Trypanosomiasis and leishmaniasis are two debilitating disease groups caused by parasites of Trypanosoma and Leishmania spp. and affecting millions of people worldwide. A brief outline of the potential targets for rational drug design against these diseases are presented, with an emphasis placed on the enzyme trypanothione reductase. Trypanothione reductase was identified as unique to parasites and proposed to be an effective target against trypanosomiasis and leishmaniasis. The biochemical basis of selecting this enzyme as a target, with reference to the simile and contrast to human analogous enzyme glutathione reductase, and the structural aspects of its active site are presented. The process of designing selective inhibitors for the enzyme trypanothione reductase has been discussed. An overview of the different chemical classes of inhibitors of trypanothione reductase with their inhibitory activities against the parasites and their prospects as future chemotherapeutic agents are briefly revealed. PMID:21901070

  2. Epigallocatechin-3-gallate potently inhibits the in vitro activity of hydroxy-3-methyl-glutaryl-CoA reductase[S

    PubMed Central

    Cuccioloni, Massimiliano; Mozzicafreddo, Matteo; Spina, Michele; Tran, Chi Nhan; Falconi, Maurizio; Eleuteri, Anna Maria; Angeletti, Mauro

    2011-01-01

    Hydroxy-3-methyl-glutaryl-CoA reductase (HMGR) is the rate-controlling enzyme of cholesterol synthesis, and owing to its biological and pharmacological relevance, researchers have investigated several compounds capable of modulating its activity with the hope of developing new hypocholesterolemic drugs. In particular, polyphenol-rich extracts were extensively tested for their cholesterol-lowering effect as alternatives, or adjuvants, to the conventional statin therapies, but a full understanding of the mechanism of their action has yet to be reached. Our work reports on a detailed kinetic and equilibrium study on the modulation of HMGR by the most-abundant catechin in green tea, epigallocatechin-3-gallate (EGCG). Using a concerted approach involving spectrophotometric, optical biosensor, and chromatographic analyses, molecular docking, and site-directed mutagenesis on the cofactor site of HMGR, we have demonstrated that EGCG potently inhibits the in vitro activity of HMGR (Ki in the nanomolar range) by competitively binding to the cofactor site of the reductase. Finally, we evaluated the effect of combined EGCG-statin administration. PMID:21357570

  3. A new cotton SDR family gene encodes a polypeptide possessing aldehyde reductase and 3-ketoacyl-CoA reductase activities.

    PubMed

    Pang, Yu; Song, Wen-Qiang; Chen, Fang-Yuan; Qin, Yong-Mei

    2010-03-01

    To understand regulatory mechanisms of cotton fiber development, microarray analysis has been performed for upland cotton (Gossypium hirsutum). Based on this, a cDNA (GhKCR3) encoding a polypeptide belonging to short-chain alcohol dehydrogenase/reductase family was isolated and cloned. It contains an open reading frame of 987 bp encoding a polypeptide of 328 amino acid residues. Following its overexpression in bacterial cells, the purified recombinant protein specifically uses NADPH to reduce a variety of short-chain aldehydes. A fragment between Gly180 and Gly191 was found to be essential for its catalytic activity. Though the GhKCR3 gene shares low sequence similarities to the ortholog of Saccharomyces cerevisiae YBR159w that encodes 3-ketoacyl-CoA reductase (KCR) catalyzing the second step of fatty acid elongation, it was surprisingly able to complement the yeast ybr159wDelta mutant. Gas chromatography-mass spectrometry analysis showed that very long-chain fatty acids, especially C26:0, were produced in the ybr159wDelta mutant cells expressing GhKCR3. Applying palmitoyl-CoA and malonyl-CoA as substrates, GhKCR3 showed KCR activity in vitro. Quantitative real time-PCR analysis indicated GhKCR3 transcripts accumulated in rapidly elongating fibers, roots, and stems. Our results suggest that GhKCR3 is probably a novel KCR contributing to very long-chain fatty acid biosynthesis in plants.

  4. Curcumin is a tight-binding inhibitor of the most efficient human daunorubicin reductase--Carbonyl reductase 1.

    PubMed

    Hintzpeter, Jan; Hornung, Jan; Ebert, Bettina; Martin, Hans-Jörg; Maser, Edmund

    2015-06-05

    Curcumin is a major component of the plant Curcuma longa L. It is traditionally used as a spice and coloring in foods and is an important ingredient in curry. Curcuminoids have anti-oxidant and anti-inflammatory properties and gained increasing attention as potential neuroprotective and cancer preventive compounds. In the present study, we report that curcumin is a potent tight-binding inhibitor of human carbonyl reductase 1 (CBR1, Ki=223 nM). Curcumin acts as a non-competitive inhibitor with respect to the substrate 2,3-hexandione as revealed by plotting IC50-values against various substrate concentrations and most likely as a competitive inhibitor with respect to NADPH. Molecular modeling supports the finding that curcumin occupies the cofactor binding site of CBR1. Interestingly, CBR1 is one of the most effective human reductases in converting the anthracycline anti-tumor drug daunorubicin to daunorubicinol. The secondary alcohol metabolite daunorubicinol has significantly reduced anti-tumor activity and shows increased cardiotoxicity, thereby limiting the clinical use of daunorubicin. Thus, inhibition of CBR1 may increase the efficacy of daunorubicin in cancer tissue and simultaneously decrease its cardiotoxicity. Western-blots demonstrated basal expression of CBR1 in several cell lines. Significantly less daunorubicin reduction was detected after incubating A549 cell lysates with increasing concentrations of curcumin (up to 60% less with 50 μM curcumin), suggesting a beneficial effect in the co-treatment of anthracycline anti-tumor drugs together with curcumin.

  5. Naegleria fowleri: a free-living highly pathogenic amoeba contains trypanothione/trypanothione reductase and glutathione/glutathione reductase systems.

    PubMed

    Ondarza, Raúl N; Hurtado, Gerardo; Tamayo, Elsa; Iturbe, Angélica; Hernández, Eva

    2006-11-01

    This paper presents definitive data showing that the thiol-bimane compound isolated and purified by HPLC from Naegleria fowleri trophozoites unequivocally corresponds by matrix assisted laser-desorption ionization-time-of-flight MS, to the characteristic monoprotonated ion of trypanothione-(bimane)(2) [M(+)H(+)] of m/z 1104.57 and to the trypanothione-(bimane) of m/z 914.46. The trypanothione disulfide T(S)(2) was also found to have a molecular ion of m/z 723.37. Additionally HPLC demonstrated that thiol-bimane compounds corresponding to cysteine and glutathione were present in Naegleria. The ion patterns of the thiol-bimane compounds prepared from commercial trypanothione standard, Entamoeba histolytica and Crithidia luciliae are identical to the Naegleria thiol-bimane compound. Partially purified extracts from N. fowleri showed the coexistence of glutathione and trypanothione reductases activities. There is not doubt that the thiol compound trypanothione, which was previously thought to occur only in Kinetoplastida, is also present in the human pathogens E. histolytica and N. fowleri, as well as in the non-pathogenic euglenozoan E. gracilis. The presence of the trypanothione/trypanothione reductase system in N. fowleri creates the possibility of using this enzyme as a new "drug target" for rationally designed drugs to eliminate the parasite, without affecting the human host.