Impaired Homocysteine Transmethylation and Protein-Methyltransferase Activity Reduce Expression of Selenoprotein P: Implications for Obesity and Metabolic Syndrome

Science.gov (United States)

Obesity causes Metabolic Syndrome and Type-II Diabetes, disrupting hepatic function, methionine (Met)/homocysteine (Hcy) transmethylation and methyltransferase (PRMT) activities. Selenoprotein P (SEPP1), exported from the liver, is the predominate form of plasma selenium (Se) and the physiological S...

Effect of Folic Acid, Betaine, Vitamin B₆, and Vitamin B12 on Homocysteine and Dimethylglycine Levels in Middle-Aged Men Drinking White Wine.

Science.gov (United States)

Rajdl, Daniel; Racek, Jaroslav; Trefil, Ladislav; Stehlik, Pavel; Dobra, Jana; Babuska, Vaclav

2016-01-12

Moderate regular consumption of alcoholic beverages is believed to protect against atherosclerosis but can also increase homocysteine or dimethylglycine, which are putative risk factors for atherosclerosis. We aimed (1) to investigate the effect of alcohol consumption on vitamins and several metabolites involved in one-carbon metabolism; and (2) to find the most effective way of decreasing homocysteine during moderate alcohol consumption. Male volunteers (n = 117) were randomly divided into five groups: the wine-only group (control, 375 mL of white wine daily for one month) and four groups combining wine consumption with one of the supplemented substances (folic acid, betaine, and vitamins B12 or B₆). Significant lowering of homocysteine concentration after the drinking period was found in subjects with concurrent folate and betaine supplementation. Vitamin B12 and vitamin B₆ supplementation did not lead to a statistically significant change in homocysteine. According to a multiple linear regression model, the homocysteine change in the wine-only group was mainly determined by the interaction between the higher baseline homocysteine concentration and the change in dimethylglycine levels. Folate and betaine can attenuate possible adverse effects of moderate alcohol consumption. Dimethylglycine should be interpreted together with data on alcohol consumption and homocysteine concentration.

The development of a new class of inhibitors for betaine-homocysteine S-methyltransferase

Czech Academy of Sciences Publication Activity Database

Pícha, Jan; Vaněk, Václav; Buděšínský, Miloš; Mládková, Jana; Garrow, T. A.; Jiráček, Jiří

2013-01-01

Roč. 65, July (2013), s. 256-275 ISSN 0223-5234 R&D Projects: GA ČR(CZ) GAP207/10/1277 Institutional support: RVO:61388963 Keywords : BHMT * inhibitor * homocysteine * phosphonate * phosphinate * amino acid derivative * bioisostere * S-alkylated homocysteine Subject RIV: CE - Biochemistry Impact factor: 3.432, year: 2013

Dietary strategies to treat hyperhomocysteinaemia based on the ...

African Journals Online (AJOL)

2014-01-13

Jan 13, 2014 ... of a methyl group and the purine base, adenine (from adenosine triphosphate or ..... rat liver betaine‑homocysteine methyltransferase gene expression and organization of the .... Betaine rescue of an animal model with.

Metabolism of S-adenosylmethionine in rat hepatocytes: transfer of methyl group from S-adenosylmethionine by methyltransferase reactions

International Nuclear Information System (INIS)

Tsukada, K.; Abe, T.; Kuwahata, T.; Mitsui, K.

1985-01-01

Treatment of rats with a methionine diet leads not only to a marked increase of S-adenosylmethionine synthetase in liver, but also to the increase of glycine, guanidoacetate and betaine-homocysteine methyltransferases. The activity of tRNA methyltransferase decreased with the increased amounts of methionine in the diets. However, the activities of phospholipids and S-adenosylmethionine-homocysteine methyltransferases did not show any significant change. When hepatocarcinogenesis induced by 2-fluorenylacetamide progresses, the activities of glycine and guanidoacetate methyltransferases in rat liver decreased, and could not be detected in tumorous areas 8 months after treatment. The levels of S-adenosylmethionine in the liver also decreased to levels of one-fifth of control animals at 8 months. The uptake and metabolism of [methyl- 3 H]-methionine and -S-adenosylmethionine have been investigated by in vivo and isolated hepatocytes. The uptake of methionine and transfer of methyl group to phospholipid in the cells by methionine were remarkably higher than those by S-adenosylmethionine. These results indicate that phospholipids in hepatocytes accept methyl group from S-adenosylmethionine immediately, when it is synthesized from methionine, before mixing its pool in the cells. 39 references, 1 figure, 2 tables

Studies on N5-methyltetrahydrofolate-homocystein methyltransferase in normal and leukemia leukocytes.

Science.gov (United States)

Peytremann, R; Thorndike, J; Beck, W S

1975-11-01

A cobalamin-dependent N5-methyltetra-hydrofolate-homocysteine methyltransferase (methyl-transferase) was demonstrated in unfractioned extracts of human normal and leukemia leukocytes. Activity was substantially reduced in the absence of an added cobalamin derivative. Presumably, this residual activity reflects the endogeneous level of holoenzyme. Enzyme activity was notably higher in lymphoid cells than in myeloid cells. Thus, mean specific activities (+/-SD) were: chronic lymphocytic leukemia lymphocytes, 2.15+/-1.16; normal lymphocytes, 0.91+/-0.59; normal mature granulocytes, 0.15+/-0.10; chronic myelocytic leukemia granulocytes, barely detectable activity. Properties of leukocytes enzymes resembled those of methyltransferases previously studied in bacteria and other animal cells. Granulocytes and chronic myelocytic leukemia cells contain a factor or factors that inhibits Escherichia coli enzyme. The data suggest that the prominence of this cobalamin-dependent enzyme in lymphocytes and other mononuclear cell types may be related to their potential for cell division.

Quantification of homocysteine-related metabolites and the role of betaine-homocysteine S-methyltransferase in HepG2 cells

Czech Academy of Sciences Publication Activity Database

Kořínek, M.; Šístek, V.; Mládková, Jana; Mikeš, P.; Jiráček, Jiří; Selicharová, Irena

2013-01-01

Roč. 27, č. 1 (2013), s. 111-121 ISSN 0269-3879 R&D Projects: GA ČR(CZ) GAP207/10/1277 Institutional support: RVO:61388963 Keywords : homocysteine * BHMT * LC-MS/MS * HepG2 * metabolites Subject RIV: CE - Biochemistry Impact factor: 1.662, year: 2013

Crystal structure of the homocysteine methyltransferase MmuM from Escherichia coli.

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Li, Kunhua; Li, Gengnan; Bradbury, Louis M T; Hanson, Andrew D; Bruner, Steven D

2016-02-01

Homocysteine S-methyltransferases (HMTs, EC 2.1.1.0) catalyse the conversion of homocysteine to methionine using S-methylmethionine or S-adenosylmethionine as the methyl donor. HMTs play an important role in methionine biosynthesis and are widely distributed among micro-organisms, plants and animals. Additionally, HMTs play a role in metabolite repair of S-adenosylmethionine by removing an inactive diastereomer from the pool. The mmuM gene product from Escherichia coli is an archetypal HMT family protein and contains a predicted zinc-binding motif in the enzyme active site. In the present study, we demonstrate X-ray structures for MmuM in oxidized, apo and metallated forms, representing the first such structures for any member of the HMT family. The structures reveal a metal/substrate-binding pocket distinct from those in related enzymes. The presented structure analysis and modelling of co-substrate interactions provide valuable insight into the function of MmuM in both methionine biosynthesis and cofactor repair. © 2016 Authors; published by Portland Press Limited.

Variability of plasma and urine betaine in diabetes mellitus and its relationship to methionine load test responses: an observational study

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Lever Michael

2012-07-01

Full Text Available Abstract Background Since betaine is an osmolyte and methyl donor, and abnormal betaine loss is common in diabetes mellitus (>20% patients, we investigated the relationship between betaine and the post-methionine load rise in homocysteine, in diabetes and control subjects. The post-methionine load test is reported to be both an independent vascular risk factor and a measure of betaine sufficiency. Methods Patients with type 2 diabetes (n = 34 and control subjects (n = 17 were recruited. We measured baseline fasting plasma and 4-hour post-methionine load (L-methionine, 0.1 mg/kg body weight concentrations of homocysteine, betaine, and the betaine metabolite N,N-dimethylglycine. Baseline urine excretions of betaine, dimethylglycine and glucose were measured on morning urine samples as the ratio to urine creatinine. Statistical determinants of the post-methionine load increase in homocysteine were identified in multiple linear regression models. Results Plasma betaine concentrations and urinary betaine excretions were significantly (p p = 0.00014 and plasma dimethylglycine concentrations (p = 0.039 were also more variable. In diabetes, plasma betaine was a significant negative determinant (p  Conclusions Both high and low plasma betaine concentrations, and high and low urinary betaine excretions, are more prevalent in diabetes. The availability of betaine affects the response in the methionine load test. The benefits of increasing betaine intake should be investigated.

Effect of homocysteine-lowering nutrients on blood lipids: results from four randomised, placebo-controlled studies in healthy humans.

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Margreet R Olthof

2005-05-01

Full Text Available BACKGROUND: Betaine (trimethylglycine lowers plasma homocysteine, a possible risk factor for cardiovascular disease. However, studies in renal patients and in obese individuals who are on a weight-loss diet suggest that betaine supplementation raises blood cholesterol; data in healthy individuals are lacking. Such an effect on cholesterol would counteract any favourable effect on homocysteine. We therefore investigated the effect of betaine, of its precursor choline in the form of phosphatidylcholine, and of the classical homocysteine-lowering vitamin folic acid on blood lipid concentrations in healthy humans. METHODS AND FINDINGS: We measured blood lipids in four placebo-controlled, randomised intervention studies that examined the effect of betaine (three studies, n = 151, folic acid (two studies, n = 75, and phosphatidylcholine (one study, n = 26 on plasma homocysteine concentrations. We combined blood lipid data from the individual studies and calculated a weighted mean change in blood lipid concentrations relative to placebo. Betaine supplementation (6 g/d for 6 wk increased blood LDL cholesterol concentrations by 0.36 mmol/l (95% confidence interval: 0.25-0.46, and triacylglycerol concentrations by 0.14 mmol/l (0.04-0.23 relative to placebo. The ratio of total to HDL cholesterol increased by 0.23 (0.14-0.32. Concentrations of HDL cholesterol were not affected. Doses of betaine lower than 6 g/d also raised LDL cholesterol, but these changes were not statistically significant. Further, the effect of betaine on LDL cholesterol was already evident after 2 wk of intervention. Phosphatidylcholine supplementation (providing approximately 2.6 g/d of choline for 2 wk increased triacylglycerol concentrations by 0.14 mmol/l (0.06-0.21, but did not affect cholesterol concentrations. Folic acid supplementation (0.8 mg/d had no effect on lipid concentrations. CONCLUSIONS: Betaine supplementation increased blood LDL cholesterol and triacylglycerol

Structures of a putative RNA 5-methyluridine methyltransferase, Thermus thermophilus TTHA1280, and its complex with S-adenosyl-l-homocysteine

International Nuclear Information System (INIS)

Pioszak, Augen A.; Murayama, Kazutaka; Nakagawa, Noriko; Ebihara, Akio; Kuramitsu, Seiki; Shirouzu, Mikako; Yokoyama, Shigeyuki

2005-01-01

Three structures of a putative RNA 5-methyluridine methyltransferase from T. thermophilus, including its complex with S-adenosyl-l-homocysteine, are presented. The structures reveal the mode of cofactor binding, architecture of the putative active site, and the presence of a deep cleft adjacent to the active site that may bind RNA. The Thermus thermophilus hypothetical protein TTHA1280 belongs to a family of predicted S-adenosyl-l-methionine (AdoMet) dependent RNA methyltransferases (MTases) present in many bacterial and archaeal species. Inspection of amino-acid sequence motifs common to class I Rossmann-fold-like MTases suggested a specific role as an RNA 5-methyluridine MTase. Selenomethionine (SeMet) labelled and native versions of the protein were expressed, purified and crystallized. Two crystal forms of the SeMet-labelled apoprotein were obtained: SeMet-ApoI and SeMet-ApoII. Cocrystallization of the native protein with S-adenosyl-l-homocysteine (AdoHcy) yielded a third crystal form, Native-AdoHcy. The SeMet-ApoI structure was solved by the multiple anomalous dispersion method and refined at 2.55 Å resolution. The SeMet-ApoII and Native-AdoHcy structures were solved by molecular replacement and refined at 1.80 and 2.60 Å, respectively. TTHA1280 formed a homodimer in the crystals and in solution. Each subunit folds into a three-domain structure composed of a small N-terminal PUA domain, a central α/β-domain and a C-terminal Rossmann-fold-like MTase domain. The three domains form an overall clamp-like shape, with the putative active site facing a deep cleft. The architecture of the active site is consistent with specific recognition of uridine and catalysis of methyl transfer to the 5-carbon position. The cleft is suitable in size and charge distribution for binding single-stranded RNA.

Combining combinatorial chemistry and affinity chromatography protocols for systematically probing protein-ligand interactions: application to the development of highly selective phosphinic inhibitors of human bataine: homocysteine S-methyltransferase

Czech Academy of Sciences Publication Activity Database

Collinsová, Michaela; Garrow, T. A.; Castro, C.; Dive, V.; Yiotakis, A.; Jiráček, Jiří

2002-01-01

Roč. 8, - (2002), s. S221 ISSN 1075-2617. [European Peptide Symposium /27./. 31.08.2002-06.09.2002, Sorrento] Institutional research plan: CEZ:AV0Z4055905 Keywords : homocysteine S-methyltransferase Subject RIV: CE - Biochemistry

Betaine is as effective as folate at re-synthesizing methionine for protein synthesis during moderate methionine deficiency in piglets.

Science.gov (United States)

McBreairty, Laura E; Robinson, Jason L; Harding, Scott V; Randell, Edward W; Brunton, Janet A; Bertolo, Robert F

2016-12-01

Both folate and betaine (synthesized from choline) are nutrients used to methylate homocysteine to reform the amino acid methionine following donation of its methyl group; however, it is unclear whether both remethylation pathways are of equal importance during the neonatal period when remethylation rates are high. Methionine is an indispensable amino acid that is in high demand in neonates not only for protein synthesis, but is also particularly important for transmethylation reactions, such as creatine and phosphatidylcholine synthesis. The objective of this study was to determine whether supplementation with folate, betaine, or a combination of both can equally re-synthesize methionine for protein synthesis when dietary methionine is limiting. Piglets were fed a low methionine diet devoid of folate, choline, and betaine, and on day 6, piglets were supplemented with either folate, betaine, or folate + betaine (n = 6 per treatment) until day 10. [1- 13 C]-phenylalanine oxidation was measured as an indicator of methionine availability for protein synthesis both before and after 2 days of supplementation. Prior to supplementation, piglets had lower concentrations of plasma folate, betaine, and choline compared to baseline with no change in homocysteine. Post-supplementation, phenylalanine oxidation levels were 20-46 % lower with any methyl donor supplementation (P = 0.006) with no difference among different supplementation groups. Furthermore, both methyl donors led to similarly lower concentrations of homocysteine following supplementation (P folate to remethylate methionine for protein synthesis, as indicated by lower phenylalanine oxidation.

Variability of plasma and urine betaine in diabetes mellitus and its relationship to methionine load test responses: an observational study

OpenAIRE

Lever, Michael; Slow, Sandy; McGregor, David O; Dellow, Warwick J; George, Peter M; Chambers, Stephen T

2012-01-01

Abstract Background Since betaine is an osmolyte and methyl donor, and abnormal betaine loss is common in diabetes mellitus (>20% patients), we investigated the relationship between betaine and the post-methionine load rise in homocysteine, in diabetes and control subjects. The post-methionine load test is reported to be both an independent vascular risk factor and a measure of betaine sufficiency. Methods Patients with type 2 diabetes (n = 34) and control subjects (n = 17) were recruited. We...

Small Molecule Inhibitors That Selectively Block Dengue Virus Methyltransferase*

OpenAIRE

Lim, Siew Pheng; Sonntag, Louis Sebastian; Noble, Christian; Nilar, Shahul H.; Ng, Ru Hui; Zou, Gang; Monaghan, Paul; Chung, Ka Yan; Dong, Hongping; Liu, Boping; Bodenreider, Christophe; Lee, Gladys; Ding, Mei; Chan, Wai Ling; Wang, Gang

2010-01-01

Crystal structure analysis of Flavivirus methyltransferases uncovered a flavivirus-conserved cavity located next to the binding site for its cofactor, S-adenosyl-methionine (SAM). Chemical derivatization of S-adenosyl-homocysteine (SAH), the product inhibitor of the methylation reaction, with substituents that extend into the identified cavity, generated inhibitors that showed improved and selective activity against dengue virus methyltransferase (MTase), but not related human enzymes. Crysta...

Homocyst(e)ine and stroke.

Science.gov (United States)

Furie, Karen L; Kelly, Peter J

2006-02-01

Homocyst(e)ine elevation is associated with a two- to threefold fold increased risk of ischemic stroke. Although most commonly associated with large-artery atherosclerosis and venous thrombosis, hyperhomocysteinemia may contribute to stroke by other mechanisms as well. Levels of homocysteine are determined by genetic regulation of the enzymes involved in homocyst(e)ine metabolism and by levels of the vitamin cofactors (folate, B (6), and B (12)) associated with those reactions. Emerging evidence suggests that genetic variation within this pathway, such as the methyleneterahydrofolate reductase and cystathionine beta-synthase and nicotinamide N-methyltransferase genes, increases the risk of ischemic stroke. The introduction of grain folate fortification in 1998 has reduced homocyst(e)ine concentrations in the U.S. population. However, it is important to screen for vitamin B (12) deficiency and be cognizant that vitamin B (6) levels may be low in the elderly and in individuals with inflammatory disorders. The Vitamin Intervention in Stroke Prevention study failed to prove that high-dose supplementation with folate, B (6), and B (12) reduced the risk of recurrent stroke or myocardial infarction at 2 years; however, there is an ongoing clinical trial evaluating the potential benefit of vitamin supplementation.

Dietary intake of S-(alpha-carboxybutyl)-DL-homocysteine induces hyperhomocysteinemia in rats

Czech Academy of Sciences Publication Activity Database

Straková, J.; Williams, K. T.; Gupta, S.; Schalinske, K. L.; Kruger, W. D.; Rozen, R.; Jiráček, Jiří; Li, L.; Garrow, T. A.

2010-01-01

Roč. 30, č. 7 (2010), s. 492-500 ISSN 0271-5317 R&D Projects: GA ČR(CZ) GAP207/10/1277 Grant - others:NIH(US) DK52501 Institutional research plan: CEZ:AV0Z40550506 Keywords : BHMT * homocysteine * rat * betaine Subject RIV: CC - Organic Chemistry Impact factor: 2.092, year: 2010

Small Molecule Inhibitors That Selectively Block Dengue Virus Methyltransferase*

Science.gov (United States)

Lim, Siew Pheng; Sonntag, Louis Sebastian; Noble, Christian; Nilar, Shahul H.; Ng, Ru Hui; Zou, Gang; Monaghan, Paul; Chung, Ka Yan; Dong, Hongping; Liu, Boping; Bodenreider, Christophe; Lee, Gladys; Ding, Mei; Chan, Wai Ling; Wang, Gang; Jian, Yap Li; Chao, Alexander Theodore; Lescar, Julien; Yin, Zheng; Vedananda, T. R.; Keller, Thomas H.; Shi, Pei-Yong

2011-01-01

Crystal structure analysis of Flavivirus methyltransferases uncovered a flavivirus-conserved cavity located next to the binding site for its cofactor, S-adenosyl-methionine (SAM). Chemical derivatization of S-adenosyl-homocysteine (SAH), the product inhibitor of the methylation reaction, with substituents that extend into the identified cavity, generated inhibitors that showed improved and selective activity against dengue virus methyltransferase (MTase), but not related human enzymes. Crystal structure of dengue virus MTase with a bound SAH derivative revealed that its N6-substituent bound in this cavity and induced conformation changes in residues lining the pocket. These findings demonstrate that one of the major hurdles for the development of methyltransferase-based therapeutics, namely selectivity for disease-related methyltransferases, can be overcome. PMID:21147775

Expression, purification, crystallization and preliminary crystallographic study of isolated modules of the mouse coactivator-associated arginine methyltransferase 1

Energy Technology Data Exchange (ETDEWEB)

Troffer-Charlier, Nathalie; Cura, Vincent; Hassenboehler, Pierre; Moras, Dino; Cavarelli, Jean, E-mail: cava@igbmc.u-strasbg.fr [IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Département de Biologie et Génomique Structurales, 1 Rue Laurent Fries, Illkirch, F-67404 (France); INSERM, U596, Illkirch, F-67400 (France); CNRS, UMR7104, Illkirch, F-67400 (France); Université Louis Pasteur, Faculté des Sciences de la Vie, Strasbourg, F-67000 (France)

2007-04-01

Isolated modules of mouse coactivator-associated arginine methyltransferase 1 encompassing the protein arginine N-methyltransferase catalytic domain have been overexpressed, purified and crystallized. X-ray diffraction data have been collected and have enabled determination of the structures by multiple isomorphous replacement using anomalous scattering. Coactivator-associated arginine methyltransferase 1 (CARM1) plays a crucial role in gene expression as a coactivator of several nuclear hormone receptors and also of non-nuclear receptor systems. Its recruitment by the transcriptional machinery induces protein methylation, leading to chromatin remodelling and gene activation. CARM1{sub 28–507} and two structural states of CARM1{sub 140–480} were expressed, purified and crystallized. Crystals of CARM1{sub 28–507} belong to space group P6{sub 2}22, with unit-cell parameters a = b = 136.0, c = 125.3 Å; they diffract to beyond 2.5 Å resolution using synchrotron radiation and contain one monomer in the asymmetric unit. The structure of CARM1{sub 28–507} was solved by multiple isomorphous replacement and anomalous scattering methods. Crystals of apo CARM1{sub 140–480} belong to space group I222, with unit-cell parameters a = 74.6, b = 99.0, c = 207.4 Å; they diffract to beyond 2.7 Å resolution and contain two monomers in the asymmetric unit. Crystals of CARM1{sub 140–480} in complex with S-adenosyl-l-homocysteine belong to space P2{sub 1}2{sub 1}2, with unit-cell parameters a = 74.6, b = 98.65, c = 206.08 Å; they diffract to beyond 2.6 Å resolution and contain four monomers in the asymmetric unit. The structures of apo and holo CARM1{sub 140–480} were solved by molecular-replacement techniques from the structure of CARM1{sub 28–507}.

Dimethylglycine accumulates in uremia and predicts elevated plasma homocysteine concentrations.

Science.gov (United States)

McGregor, D O; Dellow, W J; Lever, M; George, P M; Robson, R A; Chambers, S T

2001-06-01

Hyperhomocysteinemia is a risk factor for atherosclerosis that is common in chronic renal failure (CRF), but its cause is unknown. Homocysteine metabolism is linked to betaine-homocysteine methyl transferase (BHMT), a zinc metalloenzyme that converts glycine betaine (GB) to N,N dimethylglycine (DMG). DMG is a known feedback inhibitor of BHMT. We postulated that DMG might accumulate in CRF and contribute to hyperhomocysteinemia by inhibiting BHMT activity. Plasma and urine concentrations of GB and DMG were measured in 33 dialysis patients (15 continuous ambulatory peritoneal dialysis and 18 hemodialysis), 33 patients with CRF, and 33 age-matched controls. Concentrations of fasting plasma total homocysteine (tHcy), red cell and serum folate, vitamins B(6) and B(12), serum zinc, and routine biochemistry were also measured. Groups were compared, and determinants of plasma tHcy were identified by correlations and stepwise linear regression. Plasma DMG increased as renal function declined and was twofold to threefold elevated in dialysis patients. Plasma GB did not differ between groups. The fractional excretion of GB (FE(GB)) was increased tenfold, and FED(MG) was doubled in CRF patients compared with controls. Plasma tHcy correlated positively with plasma DMG, the plasma DMG:GB ratio, plasma creatinine, and FE(GB) and negatively with serum folate, zinc, and plasma GB. In the multiple regression model, only plasma creatinine, plasma DMG, or the DMG:GB ratio was independent predictors of tHcy. DMG accumulates in CRF and independently predicts plasma tHcy concentrations. These findings suggest that reduced BHMT activity is important in the pathogenesis of hyperhomocysteinemia in CRF.

Hepatoprotective Effects of Betaine Against Oxidative Stress Induced by Levodopa and Benserazide in Rats

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M Alirezaei

2015-02-01

Results: The study results indicated that the treatment of rats with levodopa and benserazide significantly increased total homocysteine (tHcy in plasma of the LD/Ben. group in comparison with the other groups (p <0.05. tHcy concentration was also significantly higher in LD group in comparison with control, betaine and LD/Bet. groups. Lipid peroxidation (TBARS amount of liver increased significantly in LD/Ben. group when compared to the control group which this index decreased by betaine treatment. In contrast, glutathione peroxidase and superoxide dismutase activities in liver were significantly higher in the LD-treated rats as compared to the LD/Ben. group. Serumic dopamine concentration decreased significantly in LD/Ben.-treated rats in comparison with LD and LD/Bet. groups. Conclusion: Taken together, it seems that betaine acts as an antioxidant agent regarding decrease of LD/Ben.-induced oxidative stress and is able to decrease their oxidative effects in liver of rats.

Transplacental exposure to inorganic arsenic at a hepatocarcinogenic dose induces fetal gene expression changes in mice indicative of aberrant estrogen signaling and disrupted steroid metabolism

International Nuclear Information System (INIS)

Liu Jie; Xie Yaxiong; Cooper, Ryan; Ducharme, Danica M.K.; Tennant, Raymond; Diwan, Bhalchandra A.; Waalkes, Michael P.

2007-01-01

Exposure to inorganic arsenic in utero in C3H mice produces hepatocellular carcinoma in male offspring when they reach adulthood. To help define the molecular events associated with the fetal onset of arsenic hepatocarcinogenesis, pregnant C3H mice were given drinking water containing 0 (control) or 85 ppm arsenic from day 8 to 18 of gestation. At the end of the arsenic exposure period, male fetal livers were removed and RNA isolated for microarray analysis using 22K oligo chips. Arsenic exposure in utero produced significant (p < 0.001) alterations in expression of 187 genes, with approximately 25% of aberrantly expressed genes related to either estrogen signaling or steroid metabolism. Real-time RT-PCR on selected genes confirmed these changes. Various genes controlled by estrogen, including X-inactive-specific transcript, anterior gradient-2, trefoil factor-1, CRP-ductin, ghrelin, and small proline-rich protein-2A, were dramatically over-expressed. Estrogen-regulated genes including cytokeratin 1-19 and Cyp2a4 were over-expressed, although Cyp3a25 was suppressed. Several genes involved with steroid metabolism also showed remarkable expression changes, including increased expression of 17β-hydroxysteroid dehydrogenase-7 (HSD17β7; involved in estradiol production) and decreased expression of HSD17β5 (involved in testosterone production). The expression of key genes important in methionine metabolism, such as methionine adenosyltransferase-1a, betaine-homocysteine methyltransferase and thioether S-methyltransferase, were suppressed. Thus, exposure of mouse fetus to inorganic arsenic during a critical period in development significantly alters the expression of various genes encoding estrogen signaling and steroid or methionine metabolism. These alterations could disrupt genetic programming at the very early life stage, which could impact tumor formation much later in adulthood

Modification of -Adenosyl--Homocysteine as Inhibitor of Nonstructural Protein 5 Methyltransferase Dengue Virus Through Molecular Docking and Molecular Dynamics Simulation

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Usman Sumo Friend Tambunan

2017-04-01

Full Text Available Dengue fever is still a major threat worldwide, approximately threatening two-fifths of the world’s population in tropical and subtropical countries. Nonstructural protein 5 (NS5 methyltransferase enzyme plays a vital role in the process of messenger RNA capping of dengue by transferring methyl groups from S -adenosyl- l -methionine to N7 atom of the guanine bases of RNA and the RNA ribose group of 2′OH, resulting in S -adenosyl- l -homocysteine (SAH. The modification of SAH compound was screened using molecular docking and molecular dynamics simulation, along with computational ADME-Tox (absorption, distribution, metabolism, excretion, and toxicity test. The 2 simulations were performed using Molecular Operating Environment (MOE 2008.10 software, whereas the ADME-Tox test was performed using various software. The modification of SAH compound was done using several functional groups that possess different polarities and properties, resulting in 3460 ligands to be docked. After conducting docking simulation, we earned 3 best ligands (SAH-M331, SAH-M2696, and SAH-M1356 based on ΔG binding and molecular interactions, which show better results than the standard ligands. Moreover, the results of molecular dynamics simulation show that the best ligands are still able to maintain the active site residue interaction with the binding site until the end of the simulation. After a series of molecular docking and molecular dynamics simulation were performed, we concluded that SAH-M1356 ligand is the most potential SAH-based compound to inhibit NS5 methyltransferase enzyme for treating dengue fever.

Effect of natural betaine on estimates of semen quality in mature AI boars during summer heat stress.

Science.gov (United States)

Cabezón, F A; Stewart, K R; Schinckel, A P; Barnes, W; Boyd, R D; Wilcock, P; Woodliff, J

2016-07-01

This study evaluated the effect of supplemental dietary betaine at three concentrations (0.0%, 0.63% and 1.26%) on semen characteristics, quality and quality after storage on boars. The trial was conducted between 22 July and 1 October 2014 in a boar stud located in Oklahoma. Boars were blocked by age within genetic line and randomly allotted to receive 0% (CON, n (line T)=22, n (line L)=10), 0.63% (BET-0.63%, n (line T)=21, n (line L)=6) or 1.26% (BET-1.26%, n (line T)=23, n (line L)=7). The diets containing betaine were fed over 10 weeks, to ensure supplemental betaine product (96% betaine) daily intakes of 16.34 and 32.68g, for the BET-0.63% and BET-1.26% diets, respectively. Serum homocysteine concentrations were less for animals with betaine treatments (P=0.016). Rectal temperatures of the boars were unaffected by betaine diets. Betaine tended to increase total sperm in the ejaculates when collectively compared with data of the control animals (P=0.093). Sperm morphology analysis indicated there was a greater percent of sperm with distal midpiece reflex (P=0.009) and tail (P=0.035) abnormalities in boars fed the BET-1.26% than boars fed the BET-0.63% diet. Betaine concentration in the seminal plasma was greater in boars with betaine treatments, with animals being fed the 0.63% and 1.26% diets having 59.2% and 54.5% greater betaine concentrations in seminal plasma as compared with boars of the control group (P=0.046). In conclusion, betaine supplementation at 0.63% and 1.26% tended to increase sperm concentration in the ejaculates by 6% and 13%, respectively, with no negative impacts on semen quality when 0.63% of betaine was included in the diet. Copyright © 2016 Elsevier B.V. All rights reserved.

Plastid-expressed betaine aldehyde dehydrogenase gene in carrot cultured cells, roots, and leaves confers enhanced salt tolerance.

Science.gov (United States)

Kumar, Shashi; Dhingra, Amit; Daniell, Henry

2004-09-01

Salinity is one of the major factors that limits geographical distribution of plants and adversely affects crop productivity and quality. We report here high-level expression of betaine aldehyde dehydrogenase (BADH) in cultured cells, roots, and leaves of carrot (Daucus carota) via plastid genetic engineering. Homoplasmic transgenic plants exhibiting high levels of salt tolerance were regenerated from bombarded cell cultures via somatic embryogenesis. Transformation efficiency of carrot somatic embryos was very high, with one transgenic event per approximately seven bombarded plates under optimal conditions. In vitro transgenic carrot cells transformed with the badh transgene were visually green in color when compared to untransformed carrot cells, and this offered a visual selection for transgenic lines. BADH enzyme activity was enhanced 8-fold in transgenic carrot cell cultures, grew 7-fold more, and accumulated 50- to 54-fold more betaine (93-101 micromol g(-1) dry weight of beta-Ala betaine and Gly betaine) than untransformed cells grown in liquid medium containing 100 mm NaCl. Transgenic carrot plants expressing BADH grew in the presence of high concentrations of NaCl (up to 400 mm), the highest level of salt tolerance reported so far among genetically modified crop plants. BADH expression was 74.8% in non-green edible parts (carrots) containing chromoplasts, and 53% in proplastids of cultured cells when compared to chloroplasts (100%) in leaves. Demonstration of plastid transformation via somatic embryogenesis utilizing non-green tissues as recipients of foreign DNA for the first time overcomes two of the major obstacles in extending this technology to important crop plants.

Development of first inhibitors for betaine-homocysteine S-methyltransferase 2

Czech Academy of Sciences Publication Activity Database

Mládková, J.; Vaněk, Václav; Elbert, Tomáš; Buděšínský, Miloš; Jiráček, Jiří

2012-01-01

Roč. 106, - (2012), s894-s894 ISSN 0009-2770. [EuCheMS Chemistry Congress /4./. 26.08.2012-30.08.2012, Prague] Institutional research plan: CEZ:AV0Z40550506 Keywords : enzyme catalysis * inhibitors * alkylation Subject RIV: CC - Organic Chemistry

Survival and psychomotor development with early betaine treatment in patients with severe methylenetetrahydrofolate reductase deficiency.

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Diekman, Eugene F; de Koning, Tom J; Verhoeven-Duif, Nanda M; Rovers, Maroeska M; van Hasselt, Peter M

2014-02-01

The impact of betaine treatment on outcome in patients with severe methylenetetrahydrofolate reductase (MTHFR) deficiency is presently unclear. To investigate the effect of betaine treatment on development and survival in patients with severe MTHFR deficiency. MEDLINE, EMBASE, and Cochrane databases between January 1960 and December 2012. Studies that described patients with severe MTHFR deficiency who received betaine treatment. We identified 15 case reports and case series, totaling 36 patients. Data included the following: (1) families with 2 or more patients with severe MTHFR deficiency, of whom at least 1 received betaine, or (2) single patients with severe MTHFR deficiency treated with betaine. To define severe MTHFR deficiency, methionine, homocysteine, MTHFR enzyme activity in fibroblasts, or mutations (in the MTHFR gene) had to be described as well as the effect of treatment (survival and/or psychomotor development). We compared the outcome in treated vs untreated patients and early- vs late-treated patients. Sensitivity analysis was performed to address definition of early treatment. To further assess the impact of treatment on mortality, we performed a subanalysis in families with at least 1 untreated deceased patient. Survival and psychomotor development. Eleven of 36 patients (31%) died. All deaths occurred in patients who did not receive treatment or in patients in whom treatment was delayed. In contrast, all 5 early-treated patients survived. Subgroup analysis of patients with deceased siblings-their genotypically identical controls-revealed that betaine treatment prevented mortality (P = .002). In addition, psychomotor development in surviving patients treated with betaine was normal in all 5 early-treated patients but in none of the 19 surviving patients with delayed treatment (P psychomotor development in patients with severe MTHFR deficiency, highlighting the importance of timely recognition through newborn screening.

Structural insights into mechanisms of the small RNA methyltransferase HEN1

Energy Technology Data Exchange (ETDEWEB)

Huang, Ying; Ji, Lijuan; Huang, Qichen; Vassylyev, Dmitry G.; Chen, Xuemei; Ma, Jin-Biao; (UAB); (UCR)

2010-02-22

RNA silencing is a conserved regulatory mechanism in fungi, plants and animals that regulates gene expression and defence against viruses and transgenes. Small silencing RNAs of {approx}20-30 nucleotides and their associated effector proteins, the Argonaute family proteins, are the central components in RNA silencing. A subset of small RNAs, such as microRNAs and small interfering RNAs (siRNAs) in plants, Piwi-interacting RNAs in animals and siRNAs in Drosophila, requires an additional crucial step for their maturation; that is, 2'-O-methylation on the 3' terminal nucleotide. A conserved S-adenosyl-L-methionine-dependent RNA methyltransferase, HUA ENHANCER 1 (HEN1), and its homologues are responsible for this specific modification. Here we report the 3.1 {angstrom} crystal structure of full-length HEN1 from Arabidopsis in complex with a 22-nucleotide small RNA duplex and cofactor product S-adenosyl-L-homocysteine. Highly cooperative recognition of the small RNA substrate by multiple RNA binding domains and the methyltransferase domain in HEN1 measures the length of the RNA duplex and determines the substrate specificity. Metal ion coordination by both 2' and 3' hydroxyls on the 3'-terminal nucleotide and four invariant residues in the active site of the methyltransferase domain suggests a novel Mg{sup 2+}-dependent 2'-O-methylation mechanism.

Osmotic Control of opuA Expression in Bacillus subtilis and Its Modulation in Response to Intracellular Glycine Betaine and Proline Pools

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Hoffmann, Tamara; Wensing, Annette; Brosius, Margot; Steil, Leif; Völker, Uwe

2013-01-01

Glycine betaine is an effective osmoprotectant for Bacillus subtilis. Its import into osmotically stressed cells led to the buildup of large pools, whose size was sensitively determined by the degree of the osmotic stress imposed. The amassing of glycine betaine caused repression of the formation of an osmostress-adaptive pool of proline, the only osmoprotectant that B. subtilis can synthesize de novo. The ABC transporter OpuA is the main glycine betaine uptake system of B. subtilis. Expression of opuA was upregulated in response to both sudden and sustained increases in the external osmolarity. Nonionic osmolytes exerted a stronger inducing effect on transcription than ionic osmolytes, and this was reflected in the development of corresponding OpuA-mediated glycine betaine pools. Primer extension analysis and site-directed mutagenesis pinpointed the osmotically controlled opuA promoter. Deviations from the consensus sequence of SigA-type promoters serve to keep the transcriptional activity of the opuA promoter low in the absence of osmotic stress. opuA expression was downregulated in a finely tuned manner in response to increases in the intracellular glycine betaine pool, regardless of whether this osmoprotectant was imported or was newly synthesized from choline. Such an effect was also exerted by carnitine, an effective osmoprotectant for B. subtilis that is not a substrate for the OpuA transporter. opuA expression was upregulated in a B. subtilis mutant that was unable to synthesize proline in response to osmotic stress. Collectively, our data suggest that the intracellular solute pool is a key determinant for the osmotic control of opuA expression. PMID:23175650

Comparative transcriptome analysis on the alteration of gene expression in ayu (Plecoglossus altivelis larvae associated with salinity change

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Xin-Jiang LU

2016-05-01

Full Text Available Ayu (Plecoglossus altivelis fish, which are an amphidromous species distributed in East Asia, live in brackish water (BW during their larval stage and in fresh water (FW during their adult stage. In this study, we found that FW-acclimated ayu larvae exhibited a slower growth ratio compared with that of BW-acclimated larvae. However, the mechanism underlying FW acclimation on growth suppression is poorly known. We employed transcriptome analysis to investigate the differential gene expression of FW acclimation by RNA sequencing. We identified 158 upregulated and 139 downregulated transcripts in FW-acclimated ayu larvae compared with that in BW-acclimated larvae. As determined by Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway mapping, functional annotation of the genes covered diverse biological functions and processes, and included neuroendocrinology, osmotic regulation, energy metabolism, and the cytoskeleton. Transcriptional expression of several differentially expressed genes in response to FW acclimation was further confirmed by real-time quantitative PCR. In accordance with transcriptome analysis, iodothyronine deiodinase (ID, pro-opiomelanocortin (POMC, betaine-homocysteine S-methyltransferase 1(BHMT, fructose-bisphosphate aldolase B (aldolase B, tyrosine aminotransferase (TAT, and Na+-K+ ATPase (NKA were upregulated after FW acclimation. Furthermore, the mRNA expressions of b-type natriuretic peptide (BNP and transgelin were downregulated after FW acclimation. Our data indicate that FW acclimation reduced the growth rate of ayu larvae, which might result from the expression alteration of genes related to endocrine hormones, energy metabolism, and direct osmoregulation.

Comparative transcriptome analysis on the alteration of gene expression in ayu (Plecoglossus altivelis) larvae associated with salinity change.

Science.gov (United States)

Lu, Xin-Jiang; Zhang, Hao; Yang, Guan-Jun; Li, Ming-Yun; Chen, Jiong

2016-05-18

Ayu (Plecoglossus altivelis) fish, which are an amphidromous species distributed in East Asia, live in brackish water (BW) during their larval stage and in fresh water (FW) during their adult stage. In this study, we found that FW-acclimated ayu larvae exhibited a slower growth ratio compared with that of BW-acclimated larvae. However, the mechanism underlying FW acclimation on growth suppression is poorly known. We employed transcriptome analysis to investigate the differential gene expression of FW acclimation by RNA sequencing. We identified 158 upregulated and 139 downregulated transcripts in FW-acclimated ayu larvae compared with that in BW-acclimated larvae. As determined by Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway mapping, functional annotation of the genes covered diverse biological functions and processes, and included neuroendocrinology, osmotic regulation, energy metabolism, and the cytoskeleton. Transcriptional expression of several differentially expressed genes in response to FW acclimation was further confirmed by real-time quantitative PCR. In accordance with transcriptome analysis, iodothyronine deiodinase (ID), pro-opiomelanocortin (POMC), betaine-homocysteine S-methyltransferase 1(BHMT), fructose-bisphosphate aldolase B (aldolase B), tyrosine aminotransferase (TAT), and Na(+)-K(+) ATPase (NKA) were upregulated after FW acclimation. Furthermore, the mRNA expressions of b-type natriuretic peptide (BNP) and transgelin were downregulated after FW acclimation. Our data indicate that FW acclimation reduced the growth rate of ayu larvae, which might result from the expression alteration of genes related to endocrine hormones, energy metabolism, and direct osmoregulation.

Modification of S-Adenosyl-l-Homocysteine as Inhibitor of Nonstructural Protein 5 Methyltransferase Dengue Virus Through Molecular Docking and Molecular Dynamics Simulation.

Science.gov (United States)

Tambunan, Usman Sumo Friend; Nasution, Mochammad Arfin Fardiansyah; Azhima, Fauziah; Parikesit, Arli Aditya; Toepak, Erwin Prasetya; Idrus, Syarifuddin; Kerami, Djati

2017-01-01

Dengue fever is still a major threat worldwide, approximately threatening two-fifths of the world's population in tropical and subtropical countries. Nonstructural protein 5 (NS5) methyltransferase enzyme plays a vital role in the process of messenger RNA capping of dengue by transferring methyl groups from S -adenosyl-l-methionine to N7 atom of the guanine bases of RNA and the RNA ribose group of 2'OH, resulting in S -adenosyl-l-homocysteine (SAH). The modification of SAH compound was screened using molecular docking and molecular dynamics simulation, along with computational ADME-Tox (absorption, distribution, metabolism, excretion, and toxicity) test. The 2 simulations were performed using Molecular Operating Environment (MOE) 2008.10 software, whereas the ADME-Tox test was performed using various software. The modification of SAH compound was done using several functional groups that possess different polarities and properties, resulting in 3460 ligands to be docked. After conducting docking simulation, we earned 3 best ligands (SAH-M331, SAH-M2696, and SAH-M1356) based on ΔG binding and molecular interactions, which show better results than the standard ligands. Moreover, the results of molecular dynamics simulation show that the best ligands are still able to maintain the active site residue interaction with the binding site until the end of the simulation. After a series of molecular docking and molecular dynamics simulation were performed, we concluded that SAH-M1356 ligand is the most potential SAH-based compound to inhibit NS5 methyltransferase enzyme for treating dengue fever.

Homocysteine inhibits hepatocyte proliferation via endoplasmic reticulum stress.

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Xue Yu

Full Text Available Homocysteine is an independent risk factor for coronary, cerebral, and peripheral vascular diseases. Recent studies have shown that levels of homocysteine are elevated in patients with impaired hepatic function, but the precise role of homocysteine in the development of hepatic dysfunction is unclear. In this study, we examined the effect of homocysteine on hepatocyte proliferation in vitro. Our results demonstrated that homocysteine inhibited hepatocyte proliferation by up-regulating protein levels of p53 as well as mRNA and protein levels of p21(Cip1 in primary cultured hepatocytes. Homocysteine induced cell growth arrest in p53-positive hepatocarcinoma cell line HepG2, but not in p53-null hepatocarcinoma cell line Hep3B. A p53 inhibitor pifithrin-α inhibited the expression of p21(Cip1 and attenuated homocysteine-induced cell growth arrest. Homocysteine induced TRB3 expression via endoplasmic reticulum stress pathway, resulting in Akt dephosphorylation. Knock-down of endogenous TRB3 significantly suppressed the inhibitory effect of homocysteine on cell proliferation and the phosphorylation of Akt. LiCl reversed homocysteine-mediated cell growth arrest by inhibiting TRB3-mediated Akt dephosphorylation. These results demonstrate that both TRB3 and p21(Cip1 are critical molecules in the homocysteine signaling cascade and provide a mechanistic explanation for impairment of liver regeneration in hyperhomocysteinemia.

S-Inosyl-L-Homocysteine Hydrolase, a Novel Enzyme Involved in S-Adenosyl-L-Methionine Recycling.

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Miller, Danielle; Xu, Huimin; White, Robert H

2015-07-01

S-Adenosyl-L-homocysteine, the product of S-adenosyl-L-methionine (SAM) methyltransferases, is known to be a strong feedback inhibitor of these enzymes. A hydrolase specific for S-adenosyl-L-homocysteine produces L-homocysteine, which is remethylated to methionine and can be used to regenerate SAM. Here, we show that the annotated S-adenosyl-L-homocysteine hydrolase in Methanocaldococcus jannaschii is specific for the hydrolysis and synthesis of S-inosyl-L-homocysteine, not S-adenosyl-L-homocysteine. This is the first report of an enzyme specific for S-inosyl-L-homocysteine. As with S-adenosyl-L-homocysteine hydrolase, which shares greater than 45% sequence identity with the M. jannaschii homologue, the M. jannaschii enzyme was found to copurify with bound NAD(+) and has Km values of 0.64 ± 0.4 mM, 0.0054 ± 0.006 mM, and 0.22 ± 0.11 mM for inosine, L-homocysteine, and S-inosyl-L-homocysteine, respectively. No enzymatic activity was detected with S-adenosyl-L-homocysteine as the substrate in either the synthesis or hydrolysis direction. These results prompted us to redesignate the M. jannaschii enzyme an S-inosyl-L-homocysteine hydrolase (SIHH). Identification of SIHH demonstrates a modified pathway in this methanogen for the regeneration of SAM from S-adenosyl-L-homocysteine that uses the deamination of S-adenosyl-L-homocysteine to form S-inosyl-L-homocysteine. In strictly anaerobic methanogenic archaea, such as Methanocaldococcus jannaschii, canonical metabolic pathways are often not present, and instead, unique pathways that are deeply rooted on the phylogenetic tree are utilized by the organisms. Here, we discuss the recycling pathway for S-adenosyl-L-homocysteine, produced from S-adenosyl-L-methionine (SAM)-dependent methylation reactions, which uses a hydrolase specific for S-inosyl-L-homocysteine, an uncommon metabolite. Identification of the pathways and the enzymes involved in the unique pathways in the methanogens will provide insight into the

Cloning and Functional Analysis of Phosphoethanolamine Methyltransferase Promoter from Maize (Zea mays L.

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Gai-Li Niu

2018-01-01

Full Text Available Betaine, a non-toxic osmoprotectant, is believed to accumulate considerably in plants under stress conditions to maintain the osmotic pressure and promote a variety of processes involved in growth and development. Phosphoethanolamine N-methyltransferase (PEAMT, a key enzyme for betaine synthesis, is reported to be regulated by its upstream promoter. In the present investigation, by using the transgenic approach, a 1048 bp long promoter region of ZmPEAMT gene from Zea mays was cloned and functionally characterized in tobacco. Computational analysis affirmed the existence of abiotic stress responsive cis-elements like ABRE, MYC, HST, LST etc., as well as pathogen, wound and phytohormone responsive motifs. For transformation in tobacco, four 5′-deletion constructs of 826 bp (P2, 642 bp (P3, 428 bp (P4 and 245 bp (P5 were constructed from the 1048 bp (P1 promoter fragment. The transgenic plants generated through a single event exhibited a promising expression of GUS reporter protein in the leaf tissues of treated with salt, drought, oxidative and cold stress as well as control plants. The GUS expression level progressively reduced from P1 to P5 in the leaf tissues, whereas a maximal expression was observed with the P3 construct in the leaves of control plants. The expression of GUS was noted to be higher in the leaves of osmotically- or salt-treated transgenic plants than that in the untreated (control plants. An effective expression of GUS in the transgenic plants manifests that this promoter can be employed for both stress-inducible and constitutive expression of gene(s. Due to this characteristic, this potential promoter can be effectively used for genetic engineering of several crops.

Tyrosinase inhibition due to interaction of homocyst(e)ine with copper: the mechanism for reversible hypopigmentation in homocystinuria due to cystathionine beta-synthase deficiency.

Science.gov (United States)

Reish, O; Townsend, D; Berry, S A; Tsai, M Y; King, R A

1995-01-01

Deficiency of cystathionine beta-synthase (CBS) is a genetic disorder of transsulfuration resulting in elevated plasma homocyst(e)ine and methionine and decreased cysteine. Affected patients have multisystem involvement, which may include light skin and hair. Reversible hypopigmentation in treated homocystinuric patients has been infrequently reported, and the mechanism is undefined. Two CBS-deficient homocystinuric patients manifested darkening of their hypopigmented hair following treatment that decreased plasma homocyst(e)ine. We hypothesized that homocyst(e)ine inhibits tyrosinase, the major pigment enzyme. The activity of tyrosinase extracted from pigmented human melanoma cells (MNT-1) that were grown in the presence of homocysteine was reduced in comparison to that extracted from cells grown without homocysteine. Copper sulfate restored homocyst(e)ine-inhibited tyrosinase activity when added to the culture cell media at a proportion of 1.25 mol of copper sulfate per 1 mol of DL-homocysteine. Holo-tyrosinase activity was inhibited by adding DL-homocysteine to the assay reaction mixture, and the addition of copper sulfate to the reaction mixture prevented this inhibition. Other tested compounds, L-cystine and betaine did not affect tyrosinase activity. Our data suggest that reversible hypopigmentation in homocystinuria is the result of tyrosinase inhibition by homocyst(e)ine and that the probable mechanism of this inhibition is the interaction of homocyst(e)ine with copper at the active site of tyrosinase. Images Figure 1 PMID:7611281

Preliminary X-ray analysis of twinned crystals of sarcosine dimethylglycine methyltransferase from Halorhodospira halochoris

International Nuclear Information System (INIS)

Kallio, Juha Pekka; Jänis, Janne; Nyyssölä, Antti; Hakulinen, Nina; Rouvinen, Juha

2009-01-01

The crystallization and preliminary X-ray diffraction analysis of sarcosine dimethylglycine methyltransferase from H. halochoris is reported. Sarcosine dimethylglycine methyltransferase (EC 2.1.1.157) is an enzyme from the extremely halophilic anaerobic bacterium Halorhodospira halochoris. This enzyme catalyzes the twofold methylation of sarcosine to betaine, with S-adenosylmethionine (AdoMet) as the methyl-group donor. This study presents the crystallization and preliminary X-ray analysis of recombinant sarcosine dimethylglycine methyltransferase produced in Escherichia coli. Mass spectroscopy was used to determine the purity and homogeneity of the enzyme material. Two different crystal forms, which initially appeared to be hexagonal and tetragonal, were obtained. However, on analyzing the diffraction data it was discovered that both crystal forms were pseudo-merohedrally twinned. The true crystal systems were monoclinic and orthorhombic. The monoclinic crystal diffracted to a maximum of 2.15 Å resolution and the orthorhombic crystal diffracted to 1.8 Å resolution

Methionine kinetics in adult men: effects of dietary betaine on L-[2H3-methyl-1-13C]methionine

International Nuclear Information System (INIS)

Storch, K.J.; Wagner, D.A.; Young, V.R.

1991-01-01

The effects of a daily 3-g supplement of betaine on kinetic aspects of L-[2H3-methyl-1-13C]methionine (MET) metabolism in healthy young adult men were explored. Four groups of four subjects each were given a control diet, based on an L-amino acid mixture supplying 29.5 and 21.9 mg.kg-1.d-1 of L-methionine and L-cystine for 4 d before the tracer study, conducted on day 5 during the fed state. Two groups received the control diet and two groups received the betaine supplement. Tracer was given intravenously (iv) or orally. The transmethylation rate of MET (TM), homocysteine remethylation (RM), and oxidation of methionine were estimated from plasma methionine labeling and 13C enrichment of expired air. RM tended to increase (P = 0.14) but the TM and methionine oxidation were significantly (P less than 0.05) higher after betaine supplementation when estimated with the oral tracer. No differences were detected with the intravenous tracer. Methionine concentration in plasma obtained from blood taken from subjects in the fed state was higher (P less than 0.01) with betaine supplementation. These results suggest that excess methyl-group intake may increase the dietary requirement for methionine

The role of catechol-O-methyltransferase in catechol-enhanced erythroid differentiation of K562 cells.

Science.gov (United States)

Suriguga; Li, Xiao-Fei; Li, Yang; Yu, Chun-Hong; Li, Yi-Ran; Yi, Zong-Chun

2013-12-15

Catechol is widely used in pharmaceutical and chemical industries. Catechol is also one of phenolic metabolites of benzene in vivo. Our previous study showed that catechol improved erythroid differentiation potency of K562 cells, which was associated with decreased DNA methylation in erythroid specific genes. Catechol is a substrate for the catechol-O-methyltransferase (COMT)-mediated methylation. In the present study, the role of COMT in catechol-enhanced erythroid differentiation of K562 cells was investigated. Benzidine staining showed that exposure to catechol enhanced hemin-induced hemoglobin accumulation and induced mRNA expression of erythroid specific genes in K562 cells. Treatment with catechol caused a time- and concentration-dependent increase in guaiacol concentration in the medium of cultured K562 cells. When COMT expression was knocked down by COMT shRNA expression in K562 cells, the production of guaiacol significantly reduced, and the sensitivity of K562 cells to cytotoxicity of catechol significantly increased. Knockdown of COMT expression by COMT shRNA expression also eliminated catechol-enhanced erythroid differentiation of K562 cells. In addition, the pre-treatment with methyl donor S-adenosyl-L-methionine or its demethylated product S-adenosyl-L-homocysteine induced a significant increase in hemin-induced Hb synthesis in K562 cells and the mRNA expression of erythroid specific genes. These findings indicated that O-methylation catalyzed by COMT acted as detoxication of catechol and involved in catechol-enhanced erythroid differentiation of K562 cells, and the production of S-adenosyl-L-homocysteine partly explained catechol-enhanced erythroid differentiation. © 2013.

Effects of betaine on lipopolysaccharide-induced memory impairment in mice and the involvement of GABA transporter 2

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Miwa Masaya

2011-11-01

Full Text Available Abstract Background Betaine (glycine betaine or trimethylglycine plays important roles as an osmolyte and a methyl donor in animals. While betaine is reported to suppress expression of proinflammatory molecules and reduce oxidative stress in aged rat kidney, the effects of betaine on the central nervous system are not well known. In this study, we investigated the effects of betaine on lipopolysaccharide (LPS-induced memory impairment and on mRNA expression levels of proinflammatory molecules, glial markers, and GABA transporter 2 (GAT2, a betaine/GABA transporter. Methods Mice were continuously treated with betaine for 13 days starting 1 day before they were injected with LPS, or received subacute or acute administration of betaine shortly before or after LPS injection. Then, their memory function was evaluated using Y-maze and novel object recognition tests 7 and 10-12 days after LPS injection (30 μg/mouse, i.c.v., respectively. In addition, mRNA expression levels in hippocampus were measured by real-time RT-PCR at different time points. Results Repeated administration of betaine (0.163 mmol/kg, s.c. prevented LPS-induced memory impairment. GAT2 mRNA levels were significantly increased in hippocampus 24 hr after LPS injection, and administration of betaine blocked this increase. However, betaine did not affect LPS-induced increases in levels of mRNA related to inflammatory responses. Both subacute administration (1 hr before, and 1 and 24 hr after LPS injection and acute administration (1 hr after LPS injection of betaine also prevented LPS-induced memory impairment in the Y-maze test. Conclusions These data suggest that betaine has protective effects against LPS-induced memory impairment and that prevention of LPS-induced changes in GAT2 mRNA expression is crucial to this ameliorating effect.

Biochemical diversity of betaines in earthworms

Energy Technology Data Exchange (ETDEWEB)

Liebeke, Manuel [Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ (United Kingdom); Bundy, Jacob G., E-mail: j.bundy@imperial.ac.uk [Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ (United Kingdom)

2013-01-25

Highlights: ► We develop a method for rapid untargetted analysis of betaines. ► We profile betaines in a comparative study of ten earthworm species. ► Earthworms contain a surprisingly high number of different betaine metabolites. ► Earthworms contain betaines normally seen only in plants or marine animals. -- Abstract: The ability to accumulate osmoprotectant compounds, such as betaines, is an important evolutionary feature in many organisms. This is particularly the case for organisms that live in variable environments, which may have fluctuations in moisture and salinity levels. There is, surprisingly, very little known about betaines in soil invertebrates in general, and there is almost no information about earthworms – a group that are important ‘ecosystem engineers’ and key indicators of soil health. Here, we describe a fast and reliable {sup 1}H–{sup 13}C heteronuclear single quantum coherence (HSQC) 2D NMR approach for the metabolic profiling of a series of betaines and related metabolites in tissue extracts, and list {sup 1}H and {sup 13}C chemical shifts for the trimethylammonium signal for 23 such compounds. The analysis of ten different species from three different families (Lumbricidae, Megascolecidae and Glossoscolecidae) showed an unexpected diversity of betaines present in earthworms. In total ten betaines were identified, including hydroxyproline-betaine, proline-betaine, taurine-betaine, GABA-betaine and histidine-betaine, and a further eleven as-yet unassigned putative betaine metabolites detected. The findings clearly indicate a hitherto-unappreciated important role for betaine metabolism in earthworms.

Cloning, expression, purification, crystallization and preliminary X-ray analysis of NodS N-methyltransferase from Bradyrhizobium japonicum WM9

International Nuclear Information System (INIS)

Cakici, Ozgur; Sikorski, Michal; Stepkowski, Tomasz; Bujacz, Grzegorz; Jaskolski, Mariusz

2008-01-01

The NodS N-methyltransferase, an enzyme participating in the biosynthesis of the bacterial nodulation (Nod) factor necessary to establish symbiotic nitrogen fixation with a legume plant host, has been crystallized in the apo form as well as in complex with SAH. SAH is a byproduct of SAM degradation during the SAM-dependent methylation reaction. The Nod factor (NF) is a rhizobial signal molecule that is involved in recognition of a legume host and the formation of root and stem nodules. Some unique enzymes are involved in the biosynthesis of NF, which is a variously but specifically substituted lipochitooligosaccharide. One of these enzymes is NodS, an N-methyltransferase that methylates end-deacetylated chitooligosaccharide substrates. In the methylation reaction, NodS uses S-adenosyl-l-methionine (SAM) as a methyl donor. To date, no structural information is available about NodS from any rhizobium. X-ray crystallographic studies of the NodS protein from Bradyrhizobium japonicum WM9, which infects the legumes lupin and serradella, have been undertaken. The nodS gene was cloned and the recombinant protein was expressed in Escherichia coli cells using natural amino acids and as an SeMet derivative. NodS without ligands was crystallized in the presence of PEG 3350 and MgCl 2 . The protein was also crystallized in complex with S-adenosyl-l-homocysteine (SAH) in the presence of PEG 8000 and MgCl 2 . SAH is produced from SAM as a byproduct of the methylation reaction. The crystals of apo NodS are tetragonal and diffracted X-rays to 2.42 Å resolution. The NodS–SAH complex crystallizes in an orthorhombic space group and the crystals diffracted X-rays to 1.85 Å resolution

Competitive accumulation of betaines by Escherichia coli K-12 and derivative strains lacking betaine porters.

Science.gov (United States)

Randall, K; Lever, M; Peddie, B A; Chambers, S T

1995-08-17

Escherichia coli was grown in hyperosmotic media containing both glycine betaine and one other betaine. E. coli K-12 derivative WG439 (putP- proP- proU-) did not accumulate any of 15 betaines. Strains WG445 (putP- proP- proU+), WG443 (putP- proP+ proU-) and the control strains all accumulated less betaine, (CH3)3N(+)-(CH2)n-COO-, when n was greater than 1. Accumulation was not detectable when n = 5. Both L- and D-isomers of alpha-substituted betaines were accumulated by both strains WG443 and WG445, the D-isomers more slowly. Hydroxylated alpha-substituted betaines were accumulated relatively more through the osmoregulated transport protein ProU than through ProP. In actively growing cultures glycine betaine appeared to be the preferred substrate for accumulation, but the proportion of the second accumulated betaine increased as cultures approached stationary phase.

Choline and methionine differentially alter methyl carbon metabolism in bovine neonatal hepatocytes.

Science.gov (United States)

Chandler, Tawny L; White, Heather M

2017-01-01

Intersections in hepatic methyl group metabolism pathways highlights potential competition or compensation of methyl donors. The objective of this experiment was to examine the expression of genes related to methyl group transfer and lipid metabolism in response to increasing concentrations of choline chloride (CC) and DL-methionine (DLM) in primary neonatal hepatocytes that were or were not exposed to fatty acids (FA). Primary hepatocytes isolated from 4 neonatal Holstein calves were maintained as monolayer cultures for 24 h before treatment with CC (61, 128, 2028, and 4528 μmol/L) and DLM (16, 30, 100, 300 μmol/L), with or without a 1 mmol/L FA cocktail in a factorial arrangement. After 24 h of treatment, media was collected for quantification of reactive oxygen species (ROS) and very low-density lipoprotein (VLDL), and cell lysates were collected for quantification of gene expression. No interactions were detected between CC, DLM, or FA. Both CC and DLM decreased the expression of methionine adenosyltransferase 1A (MAT1A). Increasing CC did not alter betaine-homocysteine S-methyltranferase (BHMT) but did increase 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) and methylenetetrahydrofolate reductase (MTHFR) expression. Increasing DLM decreased expression of BHMT and MTR, but did not affect MTHFR. Expression of both phosphatidylethanolamine N-methyltransferase (PEMT) and microsomal triglyceride transfer protein (MTTP) were decreased by increasing CC and DLM, while carnitine palmitoyltransferase 1A (CPT1A) was unaffected by either. Treatment with FA decreased the expression of MAT1A, MTR, MTHFR and tended to decrease PEMT but did not affect BHMT and MTTP. Treatment with FA increased CPT1A expression. Increasing CC increased secretion of VLDL and decreased the accumulation of ROS in media. Within neonatal bovine hepatocytes, choline and methionine differentially regulate methyl carbon pathways and suggest that choline may play a critical role in

Expression of DNA methyltransferases is influenced by growth hormone in the long-living Ames dwarf mouse in vivo and in vitro.

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Armstrong, Vanessa L; Rakoczy, Sharlene; Rojanathammanee, Lalida; Brown-Borg, Holly M

2014-08-01

Methyltransferase expression and DNA methylation are linked to aging and age-related disease. We utilized 3-, 12-, and 24-month-old Ames dwarf and their wild-type siblings to examine the genotype and age-related differences in the expression of methyltransferase enzymes related to DNA methylation in the liver, glycine-N-methyltransferase and DNA methyltransferase (DNMT). We found that DNMT proteins and transcripts are differentially expressed in dwarf mice compared with wild-type siblings that can be attributed to age and/or genotype. However, DNMT1 protein expression is drastically reduced compared with wild-type controls at every age. DNMT3a protein levels coincide with differences observed in DNMT activity. Growth hormone appears to modulate expression of DNMT1 and 3a in dwarf liver tissue and primary hepatocytes. Therefore, growth hormone may contribute to age-related processes, DNA methylation, and, ultimately, longevity. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The putative protein methyltransferase LAE1 controls cellulase gene expression in Trichoderma reesei

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Seiboth, Bernhard; Karimi, Razieh Aghcheh; Phatale, Pallavi A; Linke, Rita; Hartl, Lukas; Sauer, Dominik G; Smith, Kristina M; Baker, Scott E; Freitag, Michael; Kubicek, Christian P

2012-01-01

Summary Trichoderma reesei is an industrial producer of enzymes that degrade lignocellulosic polysaccharides to soluble monomers, which can be fermented to biofuels. Here we show that the expression of genes for lignocellulose degradation are controlled by the orthologous T. reesei protein methyltransferase LAE1. In a lae1 deletion mutant we observed a complete loss of expression of all seven cellulases, auxiliary factors for cellulose degradation, β-glucosidases and xylanases were no longer expressed. Conversely, enhanced expression of lae1 resulted in significantly increased cellulase gene transcription. Lae1-modulated cellulase gene expression was dependent on the function of the general cellulase regulator XYR1, but also xyr1 expression was LAE1-dependent. LAE1 was also essential for conidiation of T. reesei. Chromatin immunoprecipitation followed by high-throughput sequencing (‘ChIP-seq’) showed that lae1 expression was not obviously correlated with H3K4 di- or trimethylation (indicative of active transcription) or H3K9 trimethylation (typical for heterochromatin regions) in CAZyme coding regions, suggesting that LAE1 does not affect CAZyme gene expression by directly modulating H3K4 or H3K9 methylation. Our data demonstrate that the putative protein methyltransferase LAE1 is essential for cellulase gene expression in T. reesei through mechanisms that remain to be identified. PMID:22554051

Co-ordinate expression of glycine betaine synthesis genes linked by the FMDV 2A region in a single open reading frame in Pichia pastoris.

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Wang, Sanhong; Yao, Quanhong; Tao, Jianmin; Qiao, Yushan; Zhang, Zhen

2007-12-01

The genes encoding the two enzymes choline monooxygenase (CMO) and betaine aldehyde dehydrogenase (BADH) of glycine betaine synthesis in Suaeda salsa were cloned and fused with the 2A region of foot-and-mouth disease virus in a single open reading frame. The fused genes were placed under the control of the alcohol oxidase (AOX1) promoter in pPIC3B and transformed into P. pastoris GS115. The expression of the fused genes in P. pastoris and the ability of recombinant yeasts to tolerate environmental stresses were studied. The results showed that induced with 0.5% methanol for 96 h, the maximal activities of CMO and BADH in the tested recombinant yeasts were 45- and 44-fold higher than those in the control yeast transformed empty vector only, respectively; the content of glycine betaine in the recombinant yeasts was 28- to 35-fold higher than that in the control. The fused genes linked by 2A region of foot-and-mouth disease virus were expressed in P. pastoris successfully and the polyprotein was 'cleaved' to each functional protein. The yeasts transformed the fused genes, which were more resistant to salt, methanol, and high temperature stresses than the control as result of glycine betaine synthesis genes introduced.

The role of catechol-O-methyltransferase in catechol-enhanced erythroid differentiation of K562 cells

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Suriguga,; Li, Xiao-Fei; Li, Yang; Yu, Chun-Hong; Li, Yi-Ran; Yi, Zong-Chun, E-mail: yizc@buaa.edu.cn

2013-12-15

Catechol is widely used in pharmaceutical and chemical industries. Catechol is also one of phenolic metabolites of benzene in vivo. Our previous study showed that catechol improved erythroid differentiation potency of K562 cells, which was associated with decreased DNA methylation in erythroid specific genes. Catechol is a substrate for the catechol-O-methyltransferase (COMT)-mediated methylation. In the present study, the role of COMT in catechol-enhanced erythroid differentiation of K562 cells was investigated. Benzidine staining showed that exposure to catechol enhanced hemin-induced hemoglobin accumulation and induced mRNA expression of erythroid specific genes in K562 cells. Treatment with catechol caused a time- and concentration-dependent increase in guaiacol concentration in the medium of cultured K562 cells. When COMT expression was knocked down by COMT shRNA expression in K562 cells, the production of guaiacol significantly reduced, and the sensitivity of K562 cells to cytotoxicity of catechol significantly increased. Knockdown of COMT expression by COMT shRNA expression also eliminated catechol-enhanced erythroid differentiation of K562 cells. In addition, the pre-treatment with methyl donor S-adenosyl-L-methionine or its demethylated product S-adenosyl-L-homocysteine induced a significant increase in hemin-induced Hb synthesis in K562 cells and the mRNA expression of erythroid specific genes. These findings indicated that O-methylation catalyzed by COMT acted as detoxication of catechol and involved in catechol-enhanced erythroid differentiation of K562 cells, and the production of S-adenosyl-L-homocysteine partly explained catechol-enhanced erythroid differentiation. - Highlights: • Catechol enhanced hemin-induced hemoglobin accumulation. • COMT-catalyzed methylation acted as detoxication of catechol. • COMT involved in catechol-enhanced erythroid differentiation.

The role of catechol-O-methyltransferase in catechol-enhanced erythroid differentiation of K562 cells

International Nuclear Information System (INIS)

Suriguga,; Li, Xiao-Fei; Li, Yang; Yu, Chun-Hong; Li, Yi-Ran; Yi, Zong-Chun

2013-01-01

Catechol is widely used in pharmaceutical and chemical industries. Catechol is also one of phenolic metabolites of benzene in vivo. Our previous study showed that catechol improved erythroid differentiation potency of K562 cells, which was associated with decreased DNA methylation in erythroid specific genes. Catechol is a substrate for the catechol-O-methyltransferase (COMT)-mediated methylation. In the present study, the role of COMT in catechol-enhanced erythroid differentiation of K562 cells was investigated. Benzidine staining showed that exposure to catechol enhanced hemin-induced hemoglobin accumulation and induced mRNA expression of erythroid specific genes in K562 cells. Treatment with catechol caused a time- and concentration-dependent increase in guaiacol concentration in the medium of cultured K562 cells. When COMT expression was knocked down by COMT shRNA expression in K562 cells, the production of guaiacol significantly reduced, and the sensitivity of K562 cells to cytotoxicity of catechol significantly increased. Knockdown of COMT expression by COMT shRNA expression also eliminated catechol-enhanced erythroid differentiation of K562 cells. In addition, the pre-treatment with methyl donor S-adenosyl-L-methionine or its demethylated product S-adenosyl-L-homocysteine induced a significant increase in hemin-induced Hb synthesis in K562 cells and the mRNA expression of erythroid specific genes. These findings indicated that O-methylation catalyzed by COMT acted as detoxication of catechol and involved in catechol-enhanced erythroid differentiation of K562 cells, and the production of S-adenosyl-L-homocysteine partly explained catechol-enhanced erythroid differentiation. - Highlights: • Catechol enhanced hemin-induced hemoglobin accumulation. • COMT-catalyzed methylation acted as detoxication of catechol. • COMT involved in catechol-enhanced erythroid differentiation

Maternal Folate Status and the BHMT c.716G>A Polymorphism Affect the Betaine Dimethylglycine Pathway during Pregnancy

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Jose M. Colomina

2016-10-01

Full Text Available The effect of the betaine: homocysteine methyltransferase BHMT c.716G>A (G: guanosine; A: adenosine single nucleotide polymorphism (SNP on the BHMT pathway is unknown during pregnancy. We hypothesised that it impairs betaine to dimethylglycine conversion and that folate status modifies its effect. We studied 612 women from the Reus Tarragona Birth Cohort from ≤12 gestational weeks (GW throughout pregnancy. The frequency of the variant BHMT c.716A allele was 30.8% (95% confidence interval (CI: 28.3, 33.5. In participants with normal-high plasma folate status (>13.4 nmol/L, least square geometric mean [95% CI] plasma dimethylglycine (pDMG, µmol/L was lower in the GA (2.35 [2.23, 2.47] versus GG (2.58 [2.46, 2.70] genotype at ≤12 GW (p < 0.05 and in the GA (2.08 [1.97, 2.19] and AA (1.94 [1.75, 2.16] versus GG (2.29 [2.18, 2.40] genotypes at 15 GW (p < 0.05. No differences in pDMG between genotypes were observed in participants with possible folate deficiency (≤13.4 nmol/L (p for interactions at ≤12 GW: 0.023 and 15 GW: 0.038. PDMG was lower in participants with the AA versus GG genotype at 34 GW (2.01 [1.79, 2.25] versus 2.44 [2.16, 2.76] and at labour, 2.51 [2.39, 2.64] versus 3.00 [2.84, 3.18], (p < 0.01. Possible deficiency compared to normal-high folate status was associated with higher pDMG in multiple linear regression analysis (β coefficients [SEM] ranging from 0.07 [0.04], p < 0.05 to 0.20 [0.04], p < 0.001 in models from early and mid-late pregnancy and the AA compared to GG genotype was associated with lower pDMG (β coefficients [SEM] ranging from −0.11 [0.06], p = 0.055 to −0.23 [0.06], p < 0.001. Conclusion: During pregnancy, the BHMT pathway is affected by folate status and by the variant BHMT c.716A allele.

Neuronal DNA Methyltransferases: Epigenetic Mediators between Synaptic Activity and Gene Expression?

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Bayraktar, Gonca; Kreutz, Michael R

2018-04-01

DNMT3A and 3B are the main de novo DNA methyltransferases (DNMTs) in the brain that introduce new methylation marks to non-methylated DNA in postmitotic neurons. DNA methylation is a key epigenetic mark that is known to regulate important cellular processes in neuronal development and brain plasticity. Accumulating evidence disclosed rapid and dynamic changes in DNA methylation of plasticity-relevant genes that are important for learning and memory formation. To understand how DNMTs contribute to brain function and how they are regulated by neuronal activity is a prerequisite for a deeper appreciation of activity-dependent gene expression in health and disease. This review discusses the functional role of de novo methyltransferases and in particular DNMT3A1 in the adult brain with special emphasis on synaptic plasticity, memory formation, and brain disorders.

Sulfur amino acid metabolism in doxorubicin-resistant breast cancer cells

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Ryu, Chang Seon; Kwak, Hui Chan; Lee, Kye Sook; Kang, Keon Wook; Oh, Soo Jin; Lee, Ki Ho; Kim, Hwan Mook; Ma, Jin Yeul; Kim, Sang Kyum

2011-01-01

Although methionine dependency is a phenotypic characteristic of tumor cells, it remains to be determined whether changes in sulfur amino acid metabolism occur in cancer cells resistant to chemotherapeutic medications. We compared expression/activity of sulfur amino acid metabolizing enzymes and cellular levels of sulfur amino acids and their metabolites between normal MCF-7 cells and doxorubicin-resistant MCF-7 (MCF-7/Adr) cells. The S-adenosylmethionine/S-adenosylhomocysteine ratio, an index of transmethylation potential, in MCF-7/Adr cells decreased to ∼ 10% relative to that in MCF-7 cells, which may have resulted from down-regulation of S-adenosylhomocysteine hydrolase. Expression of homocysteine-clearing enzymes, such as cystathionine beta-synthase, methionine synthase/methylene tetrahydrofolate reductase, and betaine homocysteine methyltransferase, was up-regulated in MCF-7/Adr cells, suggesting that acquiring doxorubicin resistance attenuated methionine-dependence and activated transsulfuration from methionine to cysteine. Homocysteine was similar, which is associated with a balance between the increased expressions of homocysteine-clearing enzymes and decreased extracellular homocysteine. Despite an elevation in cysteine, cellular GSH decreased in MCF-7/Adr cells, which was attributed to over-efflux of GSH into the medium and down-regulation of the GSH synthesis enzyme. Consequently, MCF-7/Adr cells were more sensitive to the oxidative stress induced by bleomycin and menadione than MCF-7 cells. In conclusion, our results suggest that regulating sulfur amino acid metabolism may be a possible therapeutic target for chemoresistant cancer cells. These results warrant further investigations to determine the role of sulfur amino acid metabolism in acquiring anticancer drug resistance in cancer cells using chemical and biological regulators involved in sulfur amino acid metabolism. - Research highlights: → MCF-7/Adr cells showed decreases in cellular GSH

Status of Homocysteine in Polycystic Ovary Syndrome (PCOS).

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Maleedhu, Priyanka; M, Vijayabhaskar; S S B, Sharma; Kodumuri, Praveen K; Devi D, Vasundhara

2014-02-01

Polycystic ovary syndrome (PCOS) is the most common endocrine disease in women of reproductive age and is estimated to affect 5-10 % of the population. Women with PCOS have a clustering of cardiovascular risk factors, such as obesity, dyslipidemia, impaired glucose tolerance and hypertension. Homocysteine has been recognized recently as a risk factor for cardiovascular diseases. Preliminary investigations suggest that high sensitivity C-reactive protein, homocysteine and adiponectin are abnormal in women with PCOS. The possible determinants of elevated homocysteine concentration are still debated among authors who found significant correlations between homocysteine and insulin resistance or hyperandrogenism. The purpose of this study is to evaluate homocysteine levels in the PCOS population compared with controls. Study group comprised of 142 women with PCOS and 65 healthy non-PCOS controls. Body mass index (BMI), Waist circumference and serum homocysteine were measured in PCOS subjects and age matched controls. Statastical Analysis: All values are expressed as mean α SD. The results obtained are analysed statistically using the unpaired student t-test to evaluate the significance of differences between the mean values. The mean BMI, Waist circumference and serum homocysteine values are significantly increased in PCOS subjects when compared with non PCOS controls. The present study has demonstrated increase in mean serum homocysteine concentrations in women with PCOS.

Salidroside Improves Homocysteine-Induced Endothelial Dysfunction by Reducing Oxidative Stress

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Sin Bond Leung

2013-01-01

Full Text Available Hyperhomocysteinemia is associated with an increased risk for cardiovascular diseases through increased oxidative stress. Salidroside is an active ingredient of the root of Rhodiola rosea with documented antioxidative, antihypoxia and neuroprotective properties. However, the vascular benefits of salidroside against endothelial dysfunction have yet to be explored. The present study, therefore, aimed to investigate the protective effect of salidroside on homocysteine-induced endothelial dysfunction. Functional studies on the rat aortas were performed to delineate the vascular effect of salidroside. DHE imaging was used to evaluate the reactive oxygen species (ROS level in aortic wall and endothelial cells. Western blotting was performed to assess the protein expression associated with oxidative stress and nitric oxide (NO bioavailability. Exposure to homocysteine attenuated endothelium-dependent relaxations in rat aortas while salidroside pretreatment rescued it. Salidroside inhibited homocystein-induced elevation in the NOX2 expression and ROS overproduction in both aortas and cultured endothelial cells and increased phosphorylation of eNOS which was diminished by homocysteine. The present study shows that salidroside is effective in preserving the NO bioavailability and thus protects against homocysteine-induced impairment of endothelium-dependent relaxations, largely through inhibiting the NOX2 expression and ROS production. Our results indicate a therapeutic potential of salidroside in the management of oxidative-stress-associated cardiovascular dysfunction.

Salidroside Improves Homocysteine-Induced Endothelial Dysfunction by Reducing Oxidative Stress

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Leung, Sin Bond; Zhang, Huina; Lau, Chi Wai; Huang, Yu; Lin, Zhixiu

2013-01-01

Hyperhomocysteinemia is associated with an increased risk for cardiovascular diseases through increased oxidative stress. Salidroside is an active ingredient of the root of Rhodiola rosea with documented antioxidative, antihypoxia and neuroprotective properties. However, the vascular benefits of salidroside against endothelial dysfunction have yet to be explored. The present study, therefore, aimed to investigate the protective effect of salidroside on homocysteine-induced endothelial dysfunction. Functional studies on the rat aortas were performed to delineate the vascular effect of salidroside. DHE imaging was used to evaluate the reactive oxygen species (ROS) level in aortic wall and endothelial cells. Western blotting was performed to assess the protein expression associated with oxidative stress and nitric oxide (NO) bioavailability. Exposure to homocysteine attenuated endothelium-dependent relaxations in rat aortas while salidroside pretreatment rescued it. Salidroside inhibited homocystein-induced elevation in the NOX2 expression and ROS overproduction in both aortas and cultured endothelial cells and increased phosphorylation of eNOS which was diminished by homocysteine. The present study shows that salidroside is effective in preserving the NO bioavailability and thus protects against homocysteine-induced impairment of endothelium-dependent relaxations, largely through inhibiting the NOX2 expression and ROS production. Our results indicate a therapeutic potential of salidroside in the management of oxidative-stress-associated cardiovascular dysfunction. PMID:23589720

Postprandial plasma betaine and other methyl donor-related responses after consumption of minimally processed wheat bran or wheat aleurone, or wheat aleurone incorporated into bread.

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Keaveney, Edel M; Price, Ruth K; Hamill, Lesley L; Wallace, Julie M W; McNulty, Helene; Ward, Mary; Strain, J J; Ueland, Per M; Molloy, Anne M; Piironen, Vieno; von Reding, Walter; Shewry, Peter R; Ward, Jane L; Welch, Robert W

2015-02-14

The bran and particularly the aleurone fraction of wheat are high in betaine and other physiological methyl donors, which may exert beneficial physiological effects. We conducted two randomised, controlled, cross-over postprandial studies to assess and compare plasma betaine and other methyl donor-related responses following the consumption of minimally processed bran and aleurone fractions (study A) and aleurone bread (study B). For both studies, standard pharmacokinetic parameters were derived for betaine, choline, folate, dimethylglycine (DMG), total homocysteine and methionine from plasma samples taken at 0, 0·5, 1, 2 and 3 h. In study A (n 14), plasma betaine concentrations were significantly and substantially elevated from 0·5 to 3 h following the consumption of both bran and aleurone compared with the control; however, aleurone gave significantly higher responses than bran. Small, but significant, increases were also observed in DMG measures; however, no significant responses were observed in other analytes. In study B (n 13), plasma betaine concentrations were significantly and substantially higher following consumption of the aleurone bread compared with the control bread; small, but significant, increases were also observed in DMG and folate measures in response to consumption of the aleurone bread; however, no significant responses were observed in other analytes. Peak plasma betaine concentrations, which were 1·7-1·8 times the baseline levels, were attained earlier following the consumption of minimally processed aleurone compared with the aleurone bread (time taken to reach peak concentration 1·2 v. 2·1 h). These results showed that the consumption of minimally processed wheat bran, and particularly the aleurone fraction, yielded substantial postprandial increases in plasma betaine concentrations. Furthermore, these effects appear to be maintained when aleurone was incorporated into bread.

A Possible Mechanism: Vildagliptin Prevents Aortic Dysfunction through Paraoxonase and Angiopoietin-Like 3

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Qian Zhang

2018-01-01

Full Text Available The collected data have revealed the beneficial effects of dipeptidyl peptidase-4 (DPP-4 inhibitors on the vascular endothelium, including vildagliptin. However, the involved mechanisms are not yet clear. In this study, Sprague-Dawley rats were randomly divided into the following four groups: control, diabetic, diabetic + low-dose vildagliptin (10 mg/kg/d, and diabetic + high-dose vildagliptin (20 mg/kg/d. The diabetic model was created by feeding a high-fat diet for four weeks and injection of streptozotocin. Then, vildagliptin groups were given oral vildagliptin for twelve weeks, and the control and diabetic groups were given the same volume of saline. The metabolic parameters, endothelial function, and whole genome expression in the aorta were examined. After 12 weeks of treatment, vildagliptin groups showed significantly reduced blood glucose, blood total cholesterol, and attenuated endothelial dysfunction. Notably, vildagliptin may inhibit angiopoietin-like 3 (Angptl3 and betaine-homocysteine S-methyltransferase (Bhmt expression and activated paraoxonase-1 (Pon1 in the aorta of diabetic rats. These findings may demonstrate the vasoprotective pathway of vildagliptin in vivo.

Lean Body Mass Harbors Sensing Mechanisms that Allow Safeguarding of Methionine Homeostasis.

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Ingenbleek, Yves

2017-09-20

Protein-depleted states generate allosteric inhibition of liver cystathionine β-synthase (CBS), which governs the first enzymatic step of the transsulfuration cascade, resulting in upstream accretion of homocysteine (Hcy) in body fluids. A similar Hcy increase may arise from normal hepatocytes undergoing experimentally-induced impairment of betaine-homocysteine methyltransferase (BHTM) activity or from components of lean body mass (LBM) submitted to any inflammatory disorder. LBM comprises a composite agglomeration of extrarenal tissues characterized by naturally occurring BHTM inactivity. As a result of cellular injury, LBM releases high concentrations of Hcy into the extracellular space, contrasting with the disruption of normal remethylation pathways. Hyperhomocysteinemia acts as a biomarker, reflecting the severity of insult and operating as an alarm signal. Elevated Hcy levels constitute a precursor pool recognized by a CBS coding region that reacts to meet increased methionine requirements in LBM tissues, using its enhanced production in hepatocytes. Preservation of methionine homeostasis benefits from its high metabolic priority and survival value.

Lean Body Mass Harbors Sensing Mechanisms that Allow Safeguarding of Methionine Homeostasis

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Yves Ingenbleek

2017-09-01

Full Text Available Protein-depleted states generate allosteric inhibition of liver cystathionine β-synthase (CBS, which governs the first enzymatic step of the transsulfuration cascade, resulting in upstream accretion of homocysteine (Hcy in body fluids. A similar Hcy increase may arise from normal hepatocytes undergoing experimentally-induced impairment of betaine-homocysteine methyltransferase (BHTM activity or from components of lean body mass (LBM submitted to any inflammatory disorder. LBM comprises a composite agglomeration of extrarenal tissues characterized by naturally occurring BHTM inactivity. As a result of cellular injury, LBM releases high concentrations of Hcy into the extracellular space, contrasting with the disruption of normal remethylation pathways. Hyperhomocysteinemia acts as a biomarker, reflecting the severity of insult and operating as an alarm signal. Elevated Hcy levels constitute a precursor pool recognized by a CBS coding region that reacts to meet increased methionine requirements in LBM tissues, using its enhanced production in hepatocytes. Preservation of methionine homeostasis benefits from its high metabolic priority and survival value.

Structural basis for G9a-like protein lysine methyltransferase inhibition by BIX-01294

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Chang, Yanqi; Zhang, Xing; Horton, John R.; Upadhyay, Anup K.; Spannhoff, Astrid; Liu, Jin; Synder, James P.; Bedford, Mark T.; Cheng, Xiaodong; (Emory-MED); (Emory); (Texas)

2009-03-26

Histone lysine methylation is an important epigenetic mark that regulates gene expression and chromatin organization. G9a and G9a-like protein (GLP) are euchromatin-associated methyltransferases that repress transcription by methylating histone H3 Lys9. BIX-01294 was originally identified as a G9a inhibitor during a chemical library screen of small molecules and has previously been used in the generation of induced pluripotent stem cells. Here we present the crystal structure of the catalytic SET domain of GLP in complex with BIX-01294 and S-adenosyl-L-homocysteine. The inhibitor is bound in the substrate peptide groove at the location where the histone H3 residues N-terminal to the target lysine lie in the previously solved structure of the complex with histone peptide. The inhibitor resembles the bound conformation of histone H3 Lys4 to Arg8, and is positioned in place by residues specific for G9a and GLP through specific interactions.

Evaluations of the trans-sulfuration pathway in multiple liver toxicity studies

International Nuclear Information System (INIS)

Schnackenberg, Laura K.; Chen Minjun; Sun, Jinchun; Holland, Ricky D.; Dragan, Yvonne; Tong Weida; Welsh, William; Beger, Richard D.

2009-01-01

Drug-induced liver injury has been associated with the generation of reactive metabolites, which are primarily detoxified via glutathione conjugation. In this study, it was hypothesized that molecules involved in the synthesis of glutathione would be diminished to replenish the glutathione depleted through conjugation reactions. Since S-adenosylmethionine (SAMe) is the primary source of the sulfur atom in glutathione, UPLC/MS and NMR were used to evaluate metabolites involved with the transulfuration pathway in urine samples collected during studies of eight liver toxic compounds in Sprague-Dawley rats. Urinary levels of creatine were increased on day 1 or day 2 in 8 high dose liver toxicity studies. Taurine concentration in urine was increased in only 3 of 8 liver toxicity studies while SAMe was found to be reduced in 4 of 5 liver toxicity studies. To further validate the results from the metabonomic studies, microarray data from rat liver samples following treatment with acetaminophen was obtained from the Gene Expression Omnibus (GEO) database. Some genes involved in the trans-sulfuration pathway, including guanidinoacetate N-methyltransferase, glycine N-methyltransferase, betaine-homocysteine methyltransferase and cysteine dioxygenase were found to be significantly decreased while methionine adenosyl transferase II, alpha increased at 24 h post-dosing, which is consistent with the SAMe and creatine findings. The metabolic and transcriptomic results show that the trans-sulfuration pathway from SAMe to glutathione was disturbed due to the administration of heptatotoxicants

CLONING, EXPRESSION, AND CHARACTERIZATION OF RAT S-ADENOSYL-L-METHIONINE: ARSENIC (III) METHYLTRANSFERASE (CYT19)

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CLONING, EXPRESSION, AND CHARACTERIZATION OF RAT S-ADENOSYL-L-METHIONINE: ARSENIC(III) METHYLTRANSFERASE (cyt19)Stephen B. Waters1 , Felicia Walton1 , Miroslav Styblo1 , Karen Herbin-Davis2, and David J. Thomas2 1 School of Medicine, University of North Carolina at Chape...

Molecular Evolution and Expression Divergence of HMT Gene Family in Plants

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Man Zhao

2018-04-01

Full Text Available Homocysteine methyltransferase (HMT converts homocysteine to methionine using S-methylmethionine (SMM or S-adenosylmethionine (SAM as methyl donors in organisms, playing an important role in supplying methionine for the growth and the development of plants. To better understand the functions of the HMT genes in plants, we conducted a wide evolution and expression analysis of these genes. Reconstruction of the phylogenetic relationship showed that the HMT gene family was divided into Class 1 and Class 2. In Class 1, HMTs were only found in seed plants, while Class 2 presented in all land plants, which hinted that the HMT genes might have diverged in seed plants. The analysis of gene structures and selection pressures showed that they were relatively conserved during evolution. However, type I functional divergence had been detected in the HMTs. Furthermore, the expression profiles of HMTs showed their distinct expression patterns in different tissues, in which some HMTs were widely expressed in various organs, whereas the others were highly expressed in some specific organs, such as seeds or leaves. Therefore, according to our results in the evolution, functional divergence, and expression, the HMT genes might have diverged during evolution. Further analysis in the expression patterns of AthHMTs with their methyl donors suggested that the diverged HMTs might be related to supply methionine for the development of plant seeds.

Genomic survey, gene expression analysis and structural modeling suggest diverse roles of DNA methyltransferases in legumes.

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Rohini Garg

Full Text Available DNA methylation plays a crucial role in development through inheritable gene silencing. Plants possess three types of DNA methyltransferases (MTases, namely Methyltransferase (MET, Chromomethylase (CMT and Domains Rearranged Methyltransferase (DRM, which maintain methylation at CG, CHG and CHH sites. DNA MTases have not been studied in legumes so far. Here, we report the identification and analysis of putative DNA MTases in five legumes, including chickpea, soybean, pigeonpea, Medicago and Lotus. MTases in legumes could be classified in known MET, CMT, DRM and DNA nucleotide methyltransferases (DNMT2 subfamilies based on their domain organization. First three MTases represent DNA MTases, whereas DNMT2 represents a transfer RNA (tRNA MTase. Structural comparison of all the MTases in plants with known MTases in mammalian and plant systems have been reported to assign structural features in context of biological functions of these proteins. The structure analysis clearly specified regions crucial for protein-protein interactions and regions important for nucleosome binding in various domains of CMT and MET proteins. In addition, structural model of DRM suggested that circular permutation of motifs does not have any effect on overall structure of DNA methyltransferase domain. These results provide valuable insights into role of various domains in molecular recognition and should facilitate mechanistic understanding of their function in mediating specific methylation patterns. Further, the comprehensive gene expression analyses of MTases in legumes provided evidence of their role in various developmental processes throughout the plant life cycle and response to various abiotic stresses. Overall, our study will be very helpful in establishing the specific functions of DNA MTases in legumes.

A glutamate/aspartate switch controls product specificity in a protein arginine methyltransferase

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Debler, Erik W.; Jain, Kanishk; Warmack, Rebeccah A.; Feng, You; Clarke, Steven G.; Blobel, Günter; Stavropoulos, Pete

2016-02-08

Trypanosoma brucei PRMT7 (TbPRMT7) is a protein arginine methyltransferase (PRMT) that strictly monomethylates various substrates, thus classifying it as a type III PRMT. However, the molecular basis of its unique product specificity has remained elusive. Here, we present the structure of TbPRMT7 in complex with its cofactor product S-adenosyl-L-homocysteine (AdoHcy) at 2.8 Å resolution and identify a glutamate residue critical for its monomethylation behavior. TbPRMT7 comprises the conserved methyltransferase and β-barrel domains, an N-terminal extension, and a dimerization arm. The active site at the interface of the N-terminal extension, methyltransferase, and β-barrel domains is stabilized by the dimerization arm of the neighboring protomer, providing a structural basis for dimerization as a prerequisite for catalytic activity. Mutagenesis of active-site residues highlights the importance of Glu181, the second of the two invariant glutamate residues of the double E loop that coordinate the target arginine in substrate peptides/proteins and that increase its nucleophilicity. Strikingly, mutation of Glu181 to aspartate converts TbPRMT7 into a type I PRMT, producing asymmetric dimethylarginine (ADMA). Isothermal titration calorimetry (ITC) using a histone H4 peptide showed that the Glu181Asp mutant has markedly increased affinity for monomethylated peptide with respect to the WT, suggesting that the enlarged active site can favorably accommodate monomethylated peptide and provide sufficient space for ADMA formation. In conclusion, these findings yield valuable insights into the product specificity and the catalytic mechanism of protein arginine methyltransferases and have important implications for the rational (re)design of PRMTs.

S-Adenosyl-S-carboxymethyl-l-homocysteine: a novel cofactor found in the putative tRNA-modifying enzyme CmoA

International Nuclear Information System (INIS)

Byrne, Robert T.; Whelan, Fiona; Aller, Pierre; Bird, Louise E.; Dowle, Adam; Lobley, Carina M. C.; Reddivari, Yamini; Nettleship, Joanne E.; Owens, Raymond J.; Antson, Alfred A.; Waterman, David G.

2013-01-01

The putative methyltransferase CmoA is involved in the nucleoside modification of transfer RNA. X-ray crystallography and mass spectrometry are used to show that it contains a novel SAM derivative, S-adenosyl-S-carboxymethyl-l-homocysteine, in which the donor methyl group is replaced by a carboxymethyl group. Uridine at position 34 of bacterial transfer RNAs is commonly modified to uridine-5-oxyacetic acid (cmo 5 U) to increase the decoding capacity. The protein CmoA is involved in the formation of cmo 5 U and was annotated as an S-adenosyl-l-methionine-dependent (SAM-dependent) methyltransferase on the basis of its sequence homology to other SAM-containing enzymes. However, both the crystal structure of Escherichia coli CmoA at 1.73 Å resolution and mass spectrometry demonstrate that it contains a novel cofactor, S-adenosyl-S-carboxymethyl-l-homocysteine (SCM-SAH), in which the donor methyl group is substituted by a carboxymethyl group. The carboxyl moiety forms a salt-bridge interaction with Arg199 that is conserved in a large group of CmoA-related proteins but is not conserved in other SAM-containing enzymes. This raises the possibility that a number of enzymes that have previously been annotated as SAM-dependent are in fact SCM-SAH-dependent. Indeed, inspection of electron density for one such enzyme with known X-ray structure, PDB entry http://scripts.iucr.org/cgi-bin/cr.cgi?rm, suggests that the active site contains SCM-SAH and not SAM

YehZYXW of Escherichia coli Is a Low-Affinity, Non-Osmoregulatory Betaine-Specific ABC Transporter.

Science.gov (United States)

Lang, Shenhui; Cressatti, Marisa; Mendoza, Kris E; Coumoundouros, Chelsea N; Plater, Samantha M; Culham, Doreen E; Kimber, Matthew S; Wood, Janet M

2015-09-22

Transporter-mediated osmolyte accumulation stimulates the growth of Escherichia coli in high-osmolality environments. YehZYXW was predicted to be an osmoregulatory transporter because (1) osmotic and stationary phase induction of yehZYXW is mediated by RpoS, (2) the Yeh proteins are homologous to the components of known osmoregulatory ABC transporters (e.g., ProU of E. coli), and (3) YehZ models based on the structures of periplasmic betaine-binding proteins suggested that YehZ retains key betaine-binding residues. The betaines choline-O-sulfate, glycine betaine, and dimethylsulfoniopropionate bound YehZ and ProX with millimolar and micromolar affinities, respectively, as determined by equilibrium dialysis and isothermal titration calorimetry. The crystal structure of the YehZ apoprotein, determined at 1.5 Å resolution (PDB ID: 4WEP ), confirmed its similarity to other betaine-binding proteins. Small and nonpolar residues in the hinge region of YehZ (e.g., Gly223) pack more closely than the corresponding residues in ProX, stabilizing the apoprotein. Betaines bound YehZ-Gly223Ser an order of magnitude more tightly than YehZ, suggesting that weak substrate binding in YehZ is at least partially due to apo state stabilization. Neither ProX nor YehZ bound proline. Assays based on osmoprotection or proline auxotrophy failed to detect YehZYXW-mediated uptake of proline, betaines, or other osmolytes. However, transport assays revealed low-affinity glycine betaine uptake, mediated by YehZYXW, that was inhibited at high salinity. Thus, YehZYXW is a betaine transporter that shares substrate specificity, but not an osmoregulatory function, with homologues like E. coli ProU. Other work suggests that yehZYXW may be an antivirulence locus whose expression promotes persistent, asymptomatic bacterial infection.

Determination of Betaine in Jujube by Capillary Electrophoresis

Science.gov (United States)

Han, Likun; Liu, Haixing; Peng, Xuewei

2017-12-01

This paper presents the determination of betaine content in jujube by high performance capillary electrophoresis (HPCE) method. The borax solution was chosen as buffer solution, and its concentration was 40 mmol at a constant voltage of 20kV and injecting pressure time of 10s at 14°C. Linearity was kept in the concent ration range of 0.0113∼1.45mg of betaine with correlation coefficient of 0.9. The content of betaine in jujube was 85.91 mg/g (RSD = 16.6%) (n = 6). The recovery of betaine in jujube sample was in the range of 86.2% - 116.6% (n=3). This method is specific, simple and rapid and accurate, which is suitable for the detection of the content of betaine in jujube.

The effect of betaine on the foam stability: Molecular simulation

Energy Technology Data Exchange (ETDEWEB)

Gao, Fengfeng [Chemistry Engineering Department, Zibo Vocational Institute, Zibo 255314 (China); Key laboratory of Colloid and Interface Chemistry, Shandong University, Jinan 250100 (China); Liu, Guokui [Key laboratory of Colloid and Interface Chemistry, Shandong University, Jinan 250100 (China); Yuan, Shiling, E-mail: shilingyuan@sdu.edu.cn [Key laboratory of Colloid and Interface Chemistry, Shandong University, Jinan 250100 (China)

2017-06-15

Highlights: • The reasons of betaine to enhance the stability of foam films are investigated by molecular simulation. • An electrostatic structure is formed at the air/water interface due to the electrostatic interaction. • The electrostatic structure becomes denser with the increasing concentration of betaine. - Abstract: Zwitterionic betaines are widely used as foam boosters due to these can enhance the stability of foam films. In this paper, mechanistic insights of betaine to improve the stability of alkyl-polyoxyethylene carboxylate (AEC) foam are provided by molecular simulation. In the simulation, we observe the electropositive nitrogen atoms in betaine interact with the electronegative sulfur atoms, an electrostatic structure is formed at the air/water interface. Interaction energies of the mixed surfactants are calculated by the quantum chemistry methods. The calculations show betaine-AEC and betaine–betaine possess attractive interaction, and that AEC–AEC has repulsion to each other. In the other words, the repulsion between the headgroups of anionic surfactants is relaxed by betaine. Additionally, the influence of concentration of betaine on the stability of foam films is also simulated. The RDF and coordination numbers show that the electrostatic structures become denser with the increasing concentration of betaine. Therefore, entry barrier is enhanced accordingly. The SMD simulation also demonstrates the same variation tendency of entry barrier. The simulation details provide vital supplements to experiments.

Betaine is a positive regulator of mitochondrial respiration

Energy Technology Data Exchange (ETDEWEB)

Lee, Icksoo, E-mail: icksoolee@dankook.ac.kr

2015-01-09

Highlights: • Betaine enhances cytochrome c oxidase activity and mitochondrial respiration. • Betaine increases mitochondrial membrane potential and cellular energy levels. • Betaine’s anti-tumorigenic effect might be due to a reversal of the Warburg effect. - Abstract: Betaine protects cells from environmental stress and serves as a methyl donor in several biochemical pathways. It reduces cardiovascular disease risk and protects liver cells from alcoholic liver damage and nonalcoholic steatohepatitis. Its pretreatment can rescue cells exposed to toxins such as rotenone, chloroform, and LiCl. Furthermore, it has been suggested that betaine can suppress cancer cell growth in vivo and in vitro. Mitochondrial electron transport chain (ETC) complexes generate the mitochondrial membrane potential, which is essential to produce cellular energy, ATP. Reduced mitochondrial respiration and energy status have been found in many human pathological conditions including aging, cancer, and neurodegenerative disease. In this study we investigated whether betaine directly targets mitochondria. We show that betaine treatment leads to an upregulation of mitochondrial respiration and cytochrome c oxidase activity in H2.35 cells, the proposed rate limiting enzyme of ETC in vivo. Following treatment, the mitochondrial membrane potential was increased and cellular energy levels were elevated. We propose that the anti-proliferative effects of betaine on cancer cells might be due to enhanced mitochondrial function contributing to a reversal of the Warburg effect.

Folic Acid Supplementation Delays Atherosclerotic Lesion Development by Modulating MCP1 and VEGF DNA Methylation Levels In Vivo and In Vitro

Science.gov (United States)

Cui, Shanshan; Li, Wen; Lv, Xin; Wang, Pengyan; Gao, Yuxia; Huang, Guowei

2017-01-01

The pathogenesis of atherosclerosis has been partly acknowledged to result from aberrant epigenetic mechanisms. Accordingly, low folate levels are considered to be a contributing factor to promoting vascular disease because of deregulation of DNA methylation. We hypothesized that increasing the levels of folic acid may act via an epigenetic gene silencing mechanism to ameliorate atherosclerosis. Here, we investigated the atheroprotective effects of folic acid and the resultant methylation status in high-fat diet-fed ApoE knockout mice and in oxidized low-density lipoprotein-treated human umbilical vein endothelial cells. We analyzed atherosclerotic lesion histology, folate concentration, homocysteine concentration, S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), and DNA methyltransferase activity, as well as monocyte chemotactic protein-1 (MCP1) and vascular endothelial growth factor (VEGF) expression and promoter methylation. Folic acid reduced atherosclerotic lesion size in ApoE knockout mice. The underlying folic acid protective mechanism appears to operate through regulating the normal homocysteine state, upregulating the SAM: SAH ratio, elevating DNA methyltransferase activity and expression, altering MCP1 and VEGF promoter methylation, and inhibiting MCP1 and VEGF expression. We conclude that folic acid supplementation effectively prevented atherosclerosis by modifying DNA methylation through the methionine cycle, improving DNA methyltransferase activity and expression, and thus changing the expression of atherosclerosis-related genes. PMID:28475147

Crystal structure of arginine methyltransferase 6 from Trypanosoma brucei.

Directory of Open Access Journals (Sweden)

Chongyuan Wang

Full Text Available Arginine methylation plays vital roles in the cellular functions of the protozoan Trypanosoma brucei. The T. brucei arginine methyltransferase 6 (TbPRMT6 is a type I arginine methyltransferase homologous to human PRMT6. In this study, we report the crystal structures of apo-TbPRMT6 and its complex with the reaction product S-adenosyl-homocysteine (SAH. The structure of apo-TbPRMT6 displays several features that are different from those of type I PRMTs that were structurally characterized previously, including four stretches of insertion, the absence of strand β15, and a distinct dimerization arm. The comparison of the apo-TbPRMT6 and SAH-TbPRMT6 structures revealed the fine rearrangements in the active site upon SAH binding. The isothermal titration calorimetry results demonstrated that SAH binding greatly increases the affinity of TbPRMT6 to a substrate peptide derived from bovine histone H4. The western blotting and mass spectrometry results revealed that TbPRMT6 methylates bovine histone H4 tail at arginine 3 but cannot methylate several T. brucei histone tails. In summary, our results highlight the structural differences between TbPRMT6 and other type I PRMTs and reveal that the active site rearrangement upon SAH binding is important for the substrate binding of TbPRMT6.

Metal active site elasticity linked to activation of homocysteine in methionine synthases

Energy Technology Data Exchange (ETDEWEB)

Koutmos, Markos; Pejchal, Robert; Bomer, Theresa M.; Matthews, Rowena G.; Smith, Janet L.; Ludwig, Martha L. (Michigan)

2008-04-02

Enzymes possessing catalytic zinc centers perform a variety of fundamental processes in nature, including methyl transfer to thiols. Cobalamin-independent (MetE) and cobalamin-dependent (MetH) methionine synthases are two such enzyme families. Although they perform the same net reaction, transfer of a methyl group from methyltetrahydrofolate to homocysteine (Hcy) to form methionine, they display markedly different catalytic strategies, modular organization, and active site zinc centers. Here we report crystal structures of zinc-replete MetE and MetH, both in the presence and absence of Hcy. Structural investigation of the catalytic zinc sites of these two methyltransferases reveals an unexpected inversion of zinc geometry upon binding of Hcy and displacement of an endogenous ligand in both enzymes. In both cases a significant movement of the zinc relative to the protein scaffold accompanies inversion. These structures provide new information on the activation of thiols by zinc-containing enzymes and have led us to propose a paradigm for the mechanism of action of the catalytic zinc sites in these and related methyltransferases. Specifically, zinc is mobile in the active sites of MetE and MetH, and its dynamic nature helps facilitate the active site conformational changes necessary for thiol activation and methyl transfer.

S-Adenosyl-S-carboxymethyl-l-homocysteine: a novel cofactor found in the putative tRNA-modifying enzyme CmoA

Energy Technology Data Exchange (ETDEWEB)

Byrne, Robert T.; Whelan, Fiona [University of York, Heslington YO10 5DD (United Kingdom); Aller, Pierre [Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Bird, Louise E. [OPPF-UK, Research Complex at Harwell, R92 Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA (United Kingdom); Oxford University, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Dowle, Adam [University of York, Heslington YO10 5DD (United Kingdom); Lobley, Carina M. C. [Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Reddivari, Yamini; Nettleship, Joanne E.; Owens, Raymond J. [OPPF-UK, Research Complex at Harwell, R92 Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA (United Kingdom); Oxford University, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Antson, Alfred A. [University of York, Heslington YO10 5DD (United Kingdom); Waterman, David G., E-mail: david.waterman@stfc.ac.uk [STFC, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0FA (United Kingdom); University of York, Heslington YO10 5DD (United Kingdom)

2013-06-01

The putative methyltransferase CmoA is involved in the nucleoside modification of transfer RNA. X-ray crystallography and mass spectrometry are used to show that it contains a novel SAM derivative, S-adenosyl-S-carboxymethyl-l-homocysteine, in which the donor methyl group is replaced by a carboxymethyl group. Uridine at position 34 of bacterial transfer RNAs is commonly modified to uridine-5-oxyacetic acid (cmo{sup 5}U) to increase the decoding capacity. The protein CmoA is involved in the formation of cmo{sup 5}U and was annotated as an S-adenosyl-l-methionine-dependent (SAM-dependent) methyltransferase on the basis of its sequence homology to other SAM-containing enzymes. However, both the crystal structure of Escherichia coli CmoA at 1.73 Å resolution and mass spectrometry demonstrate that it contains a novel cofactor, S-adenosyl-S-carboxymethyl-l-homocysteine (SCM-SAH), in which the donor methyl group is substituted by a carboxymethyl group. The carboxyl moiety forms a salt-bridge interaction with Arg199 that is conserved in a large group of CmoA-related proteins but is not conserved in other SAM-containing enzymes. This raises the possibility that a number of enzymes that have previously been annotated as SAM-dependent are in fact SCM-SAH-dependent. Indeed, inspection of electron density for one such enzyme with known X-ray structure, PDB entry http://scripts.iucr.org/cgi-bin/cr.cgi?rm, suggests that the active site contains SCM-SAH and not SAM.

Structure and Mechanism of the Rebeccamycin Sugar 4'-O-Methyltransferase RebM

Energy Technology Data Exchange (ETDEWEB)

Singh, Shanteri; McCoy, Jason G.; Zhang, Changsheng; Bingman, Craig A.; Phillips, Jr., George N.; Thorson, Jon S. (UW)

2008-12-12

The 2.65-{angstrom} crystal structure of the rebeccamycin 4'-O-methyltransferase RebM in complex with S-adenosyl-l-homocysteine revealed RebM to adopt a typical S-adenosylmethionine-binding fold of small molecule O-methyltransferases (O-MTases) and display a weak dimerization domain unique to MTases. Using this structure as a basis, the RebM substrate binding model implicated a predominance of nonspecific hydrophobic interactions consistent with the reported ability of RebM to methylate a wide range of indolocarbazole surrogates. This model also illuminated the three putative RebM catalytic residues (His{sup 140/141} and Asp{sup 166}) subsequently found to be highly conserved among sequence-related natural product O-MTases from GC-rich bacteria. Interrogation of these residues via site-directed mutagenesis in RebM demonstrated His{sup 140} and Asp{sup 166} to be most important for catalysis. This study reveals RebM to be a member of the general acid/base-dependent O-MTases and, as the first crystal structure for a sugar O-MTase, may also present a template toward the future engineering of natural product MTases for combinatorial applications.

Functional characterization of a rice de novo DNA methyltransferase, OsDRM2, expressed in Escherichia coli and yeast

Energy Technology Data Exchange (ETDEWEB)

Pang, Jinsong, E-mail: pangjs542@nenu.edu.cn [Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun, Jilin 130024 (China); Dong, Mingyue; Li, Ning; Zhao, Yanli [Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun, Jilin 130024 (China); Liu, Bao, E-mail: baoliu@nenu.edu.cn [Key Laboratory of Molecular Epigenetics of the Ministry of Education, Northeast Normal University, Changchun, Jilin 130024 (China)

2013-03-01

Highlights: ► A rice de novo DNA methyltransferase OsDRM2 was cloned. ► In vitro methylation activity of OsDRM2 was characterized with Escherichia coli. ► Assays of OsDRM2 in vivo methylation were done with Saccharomyces cerevisiae. ► OsDRM2 methylation activity is not preferential to any type of cytosine context. ► The activity of OsDRM2 is independent of RdDM pathway. - Abstract: DNA methylation of cytosine nucleotides is an important epigenetic modification that occurs in most eukaryotic organisms and is established and maintained by various DNA methyltransferases together with their co-factors. There are two major categories of DNA methyltransferases: de novo and maintenance. Here, we report the isolation and functional characterization of a de novo methyltransferase, named OsDRM2, from rice (Oryza sativa L.). The full-length coding region of OsDRM2 was cloned and transformed into Escherichia coli and Saccharomyces cerevisiae. Both of these organisms expressed the OsDRM2 protein, which exhibited stochastic de novo methylation activity in vitro at CG, CHG, and CHH di- and tri-nucleotide patterns. Two lines of evidence demonstrated the de novo activity of OsDRM2: (1) a 5′-CCGG-3′ containing DNA fragment that had been pre-treated with OsDRM2 protein expressed in E. coli was protected from digestion by the CG-methylation-sensitive isoschizomer HpaII; (2) methylation-sensitive amplified polymorphism (MSAP) analysis of S. cerevisiae genomic DNA from transformants that had been introduced with OsDRM2 revealed CG and CHG methylation levels of 3.92–9.12%, and 2.88–6.93%, respectively, whereas the mock control S. cerevisiae DNA did not exhibit cytosine methylation. These results were further supported by bisulfite sequencing of the 18S rRNA and EAF5 genes of the transformed S. cerevisiae, which exhibited different DNA methylation patterns, which were observed in the genomic DNA. Our findings establish that OsDRM2 is an active de novo DNA

Functional characterization of a rice de novo DNA methyltransferase, OsDRM2, expressed in Escherichia coli and yeast

International Nuclear Information System (INIS)

Pang, Jinsong; Dong, Mingyue; Li, Ning; Zhao, Yanli; Liu, Bao

2013-01-01

Highlights: ► A rice de novo DNA methyltransferase OsDRM2 was cloned. ► In vitro methylation activity of OsDRM2 was characterized with Escherichia coli. ► Assays of OsDRM2 in vivo methylation were done with Saccharomyces cerevisiae. ► OsDRM2 methylation activity is not preferential to any type of cytosine context. ► The activity of OsDRM2 is independent of RdDM pathway. - Abstract: DNA methylation of cytosine nucleotides is an important epigenetic modification that occurs in most eukaryotic organisms and is established and maintained by various DNA methyltransferases together with their co-factors. There are two major categories of DNA methyltransferases: de novo and maintenance. Here, we report the isolation and functional characterization of a de novo methyltransferase, named OsDRM2, from rice (Oryza sativa L.). The full-length coding region of OsDRM2 was cloned and transformed into Escherichia coli and Saccharomyces cerevisiae. Both of these organisms expressed the OsDRM2 protein, which exhibited stochastic de novo methylation activity in vitro at CG, CHG, and CHH di- and tri-nucleotide patterns. Two lines of evidence demonstrated the de novo activity of OsDRM2: (1) a 5′-CCGG-3′ containing DNA fragment that had been pre-treated with OsDRM2 protein expressed in E. coli was protected from digestion by the CG-methylation-sensitive isoschizomer HpaII; (2) methylation-sensitive amplified polymorphism (MSAP) analysis of S. cerevisiae genomic DNA from transformants that had been introduced with OsDRM2 revealed CG and CHG methylation levels of 3.92–9.12%, and 2.88–6.93%, respectively, whereas the mock control S. cerevisiae DNA did not exhibit cytosine methylation. These results were further supported by bisulfite sequencing of the 18S rRNA and EAF5 genes of the transformed S. cerevisiae, which exhibited different DNA methylation patterns, which were observed in the genomic DNA. Our findings establish that OsDRM2 is an active de novo DNA

Plasma homocysteine levels in multiple sclerosis

NARCIS (Netherlands)

Ramsaransing, G S M; Fokkema, M R; Teelken, A; Arutjunyan, A V; Koch, M; De Keyser, J

Background: There is evidence that homocysteine contributes to various neurodegenerative disorders, and elevated plasma homocysteine levels have been observed in patients with multiple sclerosis (MS). Objective: To investigate if and why plasma homocysteine levels are increased in MS, and whether

Microsatellite instability and the association with plasma homocysteine and thymidylate synthase in colorectal cancer

DEFF Research Database (Denmark)

Jensen, Lars Henrik; Lindebjerg, Jan; Crüger, Dorthe G.

2008-01-01

, carcinoembryonic antigen, vitamin B12, and folate. Microsatellite instability of tumors was associated with higher levels of plasma homocysteine (p = 0.008) and higher protein expression of thymidylate synthase (p ... factors. CEA was not associated with neither homocysteine nor microsatellite instability. The data suggests that there is a more pronounced methyl unit deficiency in microsatellite instable tumors....

Antioxidant effects of betaine against Indomethacin-induced gastric damage in rats

Directory of Open Access Journals (Sweden)

M Alirezaei

2016-10-01

Full Text Available Introduction: Betaine (trimethyl glycine is known as methyl group donor and antioxidant in previous reports. The aim of this study was to assess the antioxidant effects of betaine in Indomethacin-induced gastric damages. Methods: Thirty-two adult male Sprague–Dawley rats in an experimental study were divided into four equal groups as follow: Control, Indomethacin, Betaine-indomethacin and Ascorbic acid-indomethacin. Control and indomethacin groups received normal saline and betaine and ascorbic acid-pretreated rats were administrated betaine (1.5% of the total diet and ascorbic acid (50 mg/kg body weight for 15 consecutive days, respectively. After 24 h fasting, all of the groups received indomethacin (48 mg/kg body weight and control group received distilled water. Results: Indomethacin administration increased gastric ulcer occurrence (% in comparison with control group and betaine pretreatment significantly decreased ulcer occurrence (% when compared to the other groups (P=0.0017. Gastric wall glutathione peroxidase (GPx activity was significantly lower in indomethacin group in comparison with the other groups (P=0.0012 while, betaine and ascorbic acid pretreatment increased GPx activity in comparison with indomethacin group (P=0.0012. Catalase activity was significantly higher in betaine-pretreated rats in comparison with indomethacin and ascorbic acid-indomethacin groups (P=0.0015. Lipid peroxidation significantly decreased in betaine and ascorbic acid pretreated groups (P=0.0013. Conclusion: These results showed beneficial antioxidant effects of betaine against gastric damages induced by indomethacin in rats.

Neuro-fuzzy model of homocysteine metabolism

Indian Academy of Sciences (India)

To conclude, polymorphisms in genes regulating remethylation of homocysteine strongly influence homocysteine levels. The restoration of one-carbon homeostasis by SHMT1 C1420T or increased flux of folate towards remethylation due to TYMS 5'-UTR 28 bp tandem repeat or nonvegetariandiet can lower homocysteine ...

Homocysteine increases the risk associated with hyperlipidaemia.

LENUS (Irish Health Repository)

Daly, Caroline

2009-04-01

The European Concerted Action Project \\'Homocysteine and Vascular Disease\\' showed that an elevated homocysteine is associated with a substantially increased risk of cardiovascular disease, and particularly when combined with other factors such as smoking, hypertension and hypercholesterolaemia. The purpose of this study was to examine the potential interactions between homocysteine and individual lipid subfractions. In addition, it was hypothesized that HDL cholesterol may protect against hyperhomocysteinaemia because HDL cholesterol is associated with the enzyme paroxonase, which reduces oxidization of homocysteine to the harmful metabolite, homocysteine thiolactonase.

The expression of spinal methyl-CpG-binding protein 2, DNA methyltransferases and histone deacetylases is modulated in persistent pain states

Directory of Open Access Journals (Sweden)

Tochiki Keri K

2012-02-01

Full Text Available Abstract Background DNA CpG methylation is carried out by DNA methyltransferases and induces chromatin remodeling and gene silencing through a transcription repressor complex comprising the methyl-CpG-binding protein 2 (MeCP2 and a subset of histone deacetylases. Recently, we have found that MeCP2 activity had a crucial role in the pattern of gene expression seen in the superficial dorsal horn rapidly after injection of Complete Freund's Adjuvant (CFA in the rat ankle joint. The aim of the present study was to analyse the changes in expression of MeCP2, DNA methyltransferases and a subset of histone deacetylases in the superficial dorsal horn during the maintenance phase of persistent pain states. In this process, the cell specific expression of MeCP2 was also investigated. Results Using immunohistochemistry, we found that neurones, oligodendrocytes and astrocytes expressed MeCP2. Microglia, oligodendrocyte precursor cells and Schwann cells never showed any positive stain for MeCP2. Quantitative analyses showed that MeCP2 expression was increased in the superficial dorsal horn 7 days following CFA injection in the ankle joint but decreased 7 days following spared nerve injury. Overall, the expression of DNA methyltransferases and a subset of histone deacetylases followed the same pattern of expression. However, there were no significant changes in the expression of the MeCP2 targets that we had previously shown are regulated in the early time points following CFA injection in the ankle joint. Finally, the expression of MeCP2 was also down regulated in damaged dorsal root ganglion neurones following spared nerve injury. Conclusion Our results strongly suggest that changes in chromatin compaction, regulated by the binding of MeCP2 complexes to methylated DNA, are involved in the modulation of gene expression in the superficial dorsal horn and dorsal root ganglia during the maintenance of persistent pain states.

Genetic impairments in folate enzymes increase dependence on dietary choline for phosphatidylcholine production at the expense of betaine synthesis.

Science.gov (United States)

Ganz, Ariel B; Shields, Kelsey; Fomin, Vlad G; Lopez, Yusnier S; Mohan, Sanjay; Lovesky, Jessica; Chuang, Jasmine C; Ganti, Anita; Carrier, Bradley; Yan, Jian; Taeswuan, Siraphat; Cohen, Vanessa V; Swersky, Camille C; Stover, Julie A; Vitiello, Gerardo A; Malysheva, Olga V; Mudrak, Erika; Caudill, Marie A

2016-10-01

Although single nucleotide polymorphisms (SNPs) in folate-mediated pathways predict susceptibility to choline deficiency during severe choline deprivation, it is unknown if effects persist at recommended intakes. Thus, we used stable isotope liquid chromatography-mass spectrometry (LC-MS) methodology to examine the impact of candidate SNPs on choline metabolism in a long-term, randomized, controlled feeding trial among pregnant, lactating, and nonpregnant (NP) women consuming 480 or 930 mg/d choline (22% as choline-d 9 , with d 9 indicating a deuterated trimethyl amine group) and meeting folate-intake recommendations. Variants impairing folate metabolism, methylenetetrahydrofolate reductase (MTHFR) rs1801133, methionine synthase (MTR) rs1805087 [wild-type (WT)], MTR reductase (MTRR) rs1801394, and methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase-formyltetrahydrofolate synthetase (MTHFD1) rs2236225, influenced choline dynamics, frequently through interactions with reproductive state and choline intake, with fewer genotypic alterations observed among pregnant women. Women with these variants partitioned more dietary choline toward phosphatidylcholine (PC) biosynthesis via the cytidine diphosphate (CDP)-choline pathway at the expense of betaine synthesis even when use of betaine as a methyl donor was increased. Choline intakes of 930 mg/d restored partitioning of dietary choline between betaine and CDP-PC among NP (MTHFR rs1801133 and MTR rs1805087 WT) and lactating (MTHFD1 rs2236225) women with risk genotypes. Overall, our findings indicate that loss-of-function variants in folate-metabolizing enzymes strain cellular PC production, possibly via impaired folate-dependent phosphatidylethanolamine-N-methyltransferase (PEMT)-PC synthesis, and suggest that women with these risk genotypes may benefit from choline intakes exceeding current recommendations.-Ganz, A. B., Shields, K., Fomin, V. G., Lopez, Y. S., Mohan, S., Lovesky, J., Chuang, J

Mining literature for a comprehensive pathway analysis: A case study for retrieval of homocysteine related genes for genetic and epigenetic studies

Directory of Open Access Journals (Sweden)

Mahajan Anubha

2006-01-01

Full Text Available Abstract Homocysteine is an independent risk factor for cardiovascular diseases. It is also known to be associated with a variety of complex disorders. While there are a large number of independent studies implicating homocysteine in isolated pathways, the mechanism of homocysteine induced adverse effects are not clear. Homocysteine-induced modulation of gene expression through alteration of methylation status or by hitherto unknown mechanisms is predicted to lead to several pathological conditions either directly or indirectly. In the present manuscript, using literature mining approach, we have identified the genes that are modulated directly or indirectly by an elevated level of homocysteine. These genes were then placed in appropriate pathways in an attempt to understand the molecular basis of homocysteine induced complex disorders and to provide a resource for selection of genes for polymorphism screening and analysis of mutations as well as epigenetic modifications in relation to hyperhomocysteinemia. We have identified 135 genes in 1137 abstracts that either modulate the levels of homocysteine or are modulated by elevated levels of homocysteine. Mapping the genes to their respective pathways revealed that an elevated level of homocysteine leads to the atherosclerosis either by directly affecting lipid metabolism and transport or via oxidative stress and/or Endoplasmic Reticulum (ER stress. Elevated levels of homocysteine also decreases the bioavailability of nitric oxide and modulates the levels of other metabolites including S-adenosyl methionine and S-adenosyl homocysteine which may result in cardiovascular or neurological disorders. The ER stress emerges as the common pathway that relates to apoptosis, atherosclerosis and neurological disorders and is modulated by levels of homocysteine. The comprehensive network collated has lead to the identification of genes that are modulated by homocysteine indicating that homocysteine exerts its

Chemical Probes of Histone Lysine Methyltransferases

Science.gov (United States)

2015-01-01

Growing evidence suggests that histone methyltransferases (HMTs, also known as protein methyltransferases (PMTs)) play an important role in diverse biological processes and human diseases by regulating gene expression and the chromatin state. Therefore, HMTs have been increasingly recognized by the biomedical community as a class of potential therapeutic targets. High quality chemical probes of HMTs, as tools for deciphering their physiological functions and roles in human diseases and testing therapeutic hypotheses, are critical for advancing this promising field. In this review, we focus on the discovery, characterization, and biological applications of chemical probes for HMTs. PMID:25423077

Glycine Betaine Recognition through Cation−π Interactions in Crystal Structures of Glycine Betaine Complexes with C-Ethyl-pyrogallol[4]arene and C-Ethyl-resorcin[4]arene as Receptors

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Ikuhide Fujisawa

2013-04-01

Full Text Available The glycine betaine (betaine, interacts with several types of proteins with diverse structures in vivo, and in the contact regions, the aromatic rings of protein residues are frequently found beside the trimethylammonium group of betaine, implying the importance of the cation−π interactions in recognition of this molecule. The crystal structures determined by X-ray crystallography of the complexes of betaine and C-ethyl-pyrogallol[4]arene (pyrogallol cyclic tetramer: PCT and betaine and C-ethyl-resorcin[4]arene (resorcinol cyclic tetramer: RCT mimic the conformations of betaine and protein complexes and show that the clathrate conformations are retained by the cation−π interactions. The difference of the conformation feature of betaine in the Protein Data Bank and in the Cambridge Structural Database was found by chance during the research and analyzed with the torsion angles.

Combining combinatorial chemistry and affinity chromatography: highly selective inhibitors of human betaine:homocysteine S-methyltransferase

Czech Academy of Sciences Publication Activity Database

Collinsová, Michaela; Castro, C.; Garrow, T. A.; Yiotakis, A.; Dive, V.; Jiráček, Jiří

2003-01-01

Roč. 10, - (2003), s. 113-122 ISSN 1074-5521 R&D Projects: GA AV ČR IAB4055003 Institutional research plan: CEZ:AV0Z4055905 Keywords : BHMT * inhibitor * phosphinic Subject RIV: CE - Biochemistry Impact factor: 6.129, year: 2003

Development of novel highly selective phosphinic pseudopeptide inhibitors of Zn-metalloenzyme betaine: homocysteine S-methyltransferase

Czech Academy of Sciences Publication Activity Database

Collinsová, Michaela

2002-01-01

Roč. 96, č. 4 (2002), s. 210-211 ISSN 0009-2770. [Sigma-Aldrich konference mladých chemiků, biochemiků a molekulárních biologů. 22.05.2002-25.05.2002, Velké Meziříčí] Institutional research plan: CEZ:AV0Z4055905 Keywords : phosphinic pseudopeptides Subject RIV: CE - Biochemistry

Effects of hyperhomocysteinemia and betaine-homocysteine S-methyltransferase inhibition on hepatocyte metabolites and the proteome

Czech Academy of Sciences Publication Activity Database

Selicharová, Irena; Kořínek, M.; Demianova, Zuzana; Chrudinová, Martina; Mládková, Jana; Jiráček, Jiří

2013-01-01

Roč. 1834, č. 8 (2013), s. 1596-1606 ISSN 1570-9639 R&D Projects: GA ČR(CZ) GAP207/10/1277 Institutional support: RVO:61388963 Keywords : apolipoprotein * fibrinogen * one-carbon metabolism * S-Adenosylmethionine * two-dimensional electrophoresis Subject RIV: CE - Biochemistry Impact factor: 3.191, year: 2013

Betaine and beet molasses enhance L-lactic acid production by Bacillus coagulans.

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Ke Xu

Full Text Available Lactic acid is an important chemical with various industrial applications, and it can be efficiently produced by fermentation, in which Bacillus coagulans strains present excellent performance. Betaine can promote lactic acid fermentation as an effective osmoprotectant. Here, positive effect of betaine on fermentation by B. coagulans is revealed. Betaine could enhance lactic acid production by protecting l-LDH activity and cell growth from osmotic inhibition, especially under high glucose concentrations and with poor organic nitrogen nutrients. The fermentation with 0.05 g/L betaine could produce 17.9% more lactic acid compared to the fermentation without betaine. Beet molasses, which is rich in sucrose and betaine, was utilized in a co-feeding fermentation and raised the productivity by 22%. The efficient lactic acid fermentation by B. coagulans is thus developed by using betaine and beet molasses.

Betaine and beet molasses enhance L-lactic acid production by Bacillus coagulans.

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Xu, Ke; Xu, Ping

2014-01-01

Lactic acid is an important chemical with various industrial applications, and it can be efficiently produced by fermentation, in which Bacillus coagulans strains present excellent performance. Betaine can promote lactic acid fermentation as an effective osmoprotectant. Here, positive effect of betaine on fermentation by B. coagulans is revealed. Betaine could enhance lactic acid production by protecting l-LDH activity and cell growth from osmotic inhibition, especially under high glucose concentrations and with poor organic nitrogen nutrients. The fermentation with 0.05 g/L betaine could produce 17.9% more lactic acid compared to the fermentation without betaine. Beet molasses, which is rich in sucrose and betaine, was utilized in a co-feeding fermentation and raised the productivity by 22%. The efficient lactic acid fermentation by B. coagulans is thus developed by using betaine and beet molasses.

Molecular cloning and functional expression of a stress-induced multifunctional O-methyltransferase with pinosylvin methyltransferase activity from Scots pine (Pinus sylvestris L.).

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Chiron, H; Drouet, A; Claudot, A C; Eckerskorn, C; Trost, M; Heller, W; Ernst, D; Sandermann, H

2000-12-01

Formation of pinosylvin (PS) and pinosylvin 3-O-monomethyl ether (PSM), as well as the activities of stilbene synthase (STS) and S-adenosyl-1-methionine (SAM):pinosylvin O-methyltransferase (PMT), were induced strongly in needles of Scots pine seedlings upon ozone treatment, as well as in cell suspension cultures of Scots pine upon fungal elicitation. A SAM-dependent PMT protein was purified and partially characterised. A cDNA encoding PMT was isolated from an ozone-induced Scots pine cDNA library. Southern blot analysis of the genomic DNA suggested the presence of a gene family. The deduced protein sequence showed the typical highly conserved regions of O-methyltransferases (OMTs), and average identities of 20-56% to known OMTs. PMT expressed in Escherichia coli corresponded to that of purified PMT (40 kDa) from pine cell cultures. The recombinant enzyme catalysed the methylation of PS, caffeic acid, caffeoyl-CoA and quercetin. Several other substances, such as astringenin, resveratrol, 5-OH-ferulic acid, catechol and luteolin, were also methylated. Recombinant PMT thus had a relatively broad substrate specificity. Treatment of 7-year old Scots pine trees with ozone markedly increased the PMT mRNA level. Our results show that PMT represents a new SAM-dependent OMT for the methylation of stress-induced pinosylvin in Scots pine needles.

Association between malnutrition and hyperhomocysteine in Alzheimer's disease patients and diet intervention of betaine.

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Sun, Jianying; Wen, Shiling; Zhou, Jing; Ding, Shuling

2017-09-01

Alzheimer's disease (AD) is a neurodegenerative disease, which is associated with malnutrition and hyperhomocysteine. The current study aimed to analyze the relationship between malnutrition and hyperhomocysteine in AD patients, and effects of diet intervention with betaine on the disease. The nutritional statuses of the AD patients were assessed by short form mini nutritional assessment (MNA-SF). The levels of Hcy, tau hyperphosphorylation, synaptic proteins, blood inflammatory factors were measured by enzymatic cycling assay, Western blot and ELISA. The cognitive function was measured by AD assessment scale (ADAS-cog). There was a significant difference in mental status between normal people and AD patients (Pmalnutrition was reported in a larger proportion of AD patients and high level of Hcy was closely associated with malnutrition. Betaine decreased the levels of phosphorylated tau, elevated PP2Ac activity and inhibited Aβ accumulation (Pmalnutrition and higher levels of Hcy. Betaine could restore Hcy expression to normal level in AD patient, which might ameliorate memory deficits. © 2016 Wiley Periodicals, Inc.

Homocysteine, Cortisol, Diabetes Mellitus, and Psychopathology

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K. Kontoangelos

2015-01-01

Full Text Available Objective. This study investigates the association of homocysteine and cortisol with psychological factors in type 2 diabetic patients. Method. Homocysteine, cortisol, and psychological variables were analyzed from 131 diabetic patients. Psychological factors were assessed with the Eysenck Personality Questionnaire (EPQ, Hostility and Direction of Hostility Questionnaire (HDHQ, the Symptom Checklist 90-R (SCL 90-R, the Zung Self-Rating Depression Scale (ZDRS, and the Maudsley O-C Inventory Questionnaire (MOCI. Blood samples were taken by measuring homocysteine and cortisol in both subgroups during the initial phase of the study (T0. One year later (T1, the uncontrolled diabetic patients were reevaluated with the use of the same psychometric instruments and with an identical blood analysis. Results. The relation of psychoticism and homocysteine is positive among controlled diabetic patients (P value = 0.006<0.05 and negative among uncontrolled ones (P value = 0.137. Higher values of cortisol correspond to lower scores on extraversion subscale (rp=-0.223, P value = 0.010. Controlled diabetic patients showed a statistically significant negative relationship between homocysteine and the act-out hostility subscale (rsp=-0.247, P=0.023. There is a statistically significant relationship between homocysteine and somatization (rsp=-0.220, P=0.043. Conclusions. These findings support the notion that homocysteine and cortisol are related to trait and state psychological factors in patients with diabetes mellitus type 2.

Crystal Structure of the Thermus thermophilus 16 S rRNA Methyltransferase RsmC in Complex with Cofactor and Substrate Guanosine

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Demirci, H.; Gregory, S; Dahlberg, A; Jogl, G

2008-01-01

Post-transcriptional modification is a ubiquitous feature of ribosomal RNA in all kingdoms of life. Modified nucleotides are generally clustered in functionally important regions of the ribosome, but the functional contribution to protein synthesis is not well understood. Here we describe high resolution crystal structures for the N{sup 2}-guanine methyltransferase RsmC that modifies residue G1207 in 16 S rRNA near the decoding site of the 30 S ribosomal subunit. RsmC is a class I S-adenosyl-l-methionine-dependent methyltransferase composed of two methyltransferase domains. However, only one S-adenosyl-l-methionine molecule and one substrate molecule, guanosine, bind in the ternary complex. The N-terminal domain does not bind any cofactor. Two structures with bound S-adenosyl-l-methionine and S-adenosyl-l-homocysteine confirm that the cofactor binding mode is highly similar to other class I methyltransferases. Secondary structure elements of the N-terminal domain contribute to cofactor-binding interactions and restrict access to the cofactor-binding site. The orientation of guanosine in the active site reveals that G1207 has to disengage from its Watson-Crick base pairing interaction with C1051 in the 16 S rRNA and flip out into the active site prior to its modification. Inspection of the 30 S crystal structure indicates that access to G1207 by RsmC is incompatible with the native subunit structure, consistent with previous suggestions that this enzyme recognizes a subunit assembly intermediate.

Betaine attenuates memory impairment after water-immersion restraint stress and is regulated by the GABAergic neuronal system in the hippocampus.

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Kunisawa, Kazuo; Kido, Kiwamu; Nakashima, Natsuki; Matsukura, Takuya; Nabeshima, Toshitaka; Hiramatsu, Masayuki

2017-02-05

GABA mediated neuronal system regulates hippocampus-dependent memory and stress responses by controlling plasticity and neuronal excitability. Here, we demonstrate that betaine ameliorates water-immersion restraint stress (WIRS)-induced memory impairments. This improvement was inhibited by a betaine/GABA transporter-1 (GABA transporter-2: GAT2) inhibitor, NNC 05-2090. In this study, we investigated whether memory amelioration by betaine was mediated by the GABAergic neuronal system. Adult male mice were co-administered betaine and GABA receptor antagonists after WIRS. We also examined whether memory impairment after WIRS was attenuated by GABA receptor agonists. The memory functions were evaluated using a novel object recognition test 3-6 days after WIRS and/or the step-down type passive avoidance test at 7-8 days. The co-administration of the GABA A receptor antagonist bicuculline (1mg/kg) or the GABA B receptor antagonist phaclofen (10mg/kg) 1h after WIRS suppressed the memory-improving effects induced by betaine. Additionally, the administration of the GABA A receptor agonist muscimol (1mg/kg) or the GABA B receptor agonist baclofen (10mg/kg) 1h after WIRS attenuated memory impairments. These results were similar to the data observed with betaine. The treatment with betaine after WIRS significantly decreased the expression of GABA transaminase, and this effect was partially blocked by NNC 05-2090 in the hippocampus. WIRS caused a transient increase in hippocampal GABA levels and the changes after WIRS were not affected by betaine treatment in an in vivo microdialysis study. These results suggest that the beneficial effects of betaine may be mediated in part by changing the GABAergic neuronal system. Copyright © 2016 Elsevier B.V. All rights reserved.

Determination of Betaine in Lycii Cortex by Capillary Electrophoresis

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Peng, Xuewei; Liu, Haixing

2017-12-01

This paper presents the determination of betaine content in Lycii Cortex by high performance capillary electrophoresis (HPCE) method. The borax solution was chosen as buffer solution, and its concentration was 40 mmol at a constant voltage of 20kV and injecting pressure time of 10s at 14°C. Linearity was kept in the concent ration range of 0.0113∼1.45mg of betaine with correlation coefficient of 0.9. The content of betaine in Lycii Cortex was 61.9 mg/g (RSD = 13.4%) (n = 7). The recovery was in the range of 86.6% - 118.1% (n=4). This method is specific, simple and rapid and accurate, which is suitable for the detection of the content of betaine in Lycii Cortex.

ACS6, a Hydrogen sulfide-donating derivative of sildenafil, inhibits homocysteine-induced apoptosis by preservation of mitochondrial function

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Tang Xiao-Qing

2011-08-01

Full Text Available Abstract Background The hydrogen sulfide-releasing sildenafil, ACS6, has been demonstrated to inhibit superoxide formation through donating hydrogen sulfide (H2S. We have found that H2S antagonizes homocysteine-induced oxidative stress and neurotoxicity. The aim of the present study is to explore the protection of ACS6 against homocysteine-triggered cytotoxicity and apoptosis and the molecular mechanisms underlying in PC12 cells. Methods Cell viability was determined by Cell Counting Kit-8 assay. Cell apoptosis was observed using the chromatin dye Hoechst 33258 and analyzed by Flow Cytometry after propidium iodide staining. Mitochondrial membrane potential was monitored using the fluorescent dye Rh123. Intracellular reactive oxygen species were determined by oxidative conversion of cell permeable 2',7'-dichlorfluorescein-diacetate to fluorescent 2',7'-dichlorfluorescein. The expression of cleaved caspase-3 and bcl-2 and the accumulation of cytosolic cytochrome c were analyzed by Western blot. Results We show that ACS6 protects PC12 cells against cytotoxicity and apoptosis induced by homocysteine and blocks homocysteine-triggered cytochrome c release and caspase-3 activation. ACS6 treatment results in not only prevention of homocysteine-caused mitochondrial membrane potential (Δψ loss and reactive oxygen species (ROS overproduction but also reversal of Bcl-2 down-expression. Conclusions These results indicate that ACS6 protects PC12 cells against homocysteine-induced cytotoxicity and apoptosis by preservation of mitochondrial function though inhibiting both loss of Δψ and accumulation of ROS as well as modulating the expression of Bcl-2. Our study provides evidence both for a neuroprotective effect of ACS6 and for further evaluation of ACS6 as novel neuroprotectants for Alzheimer's disease associated with homocysteine.

Egg quality of quails fed low methionine diet supplemented with betaine

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Ratriyanto, A.; Indreswari, R.; Dewanti, R.; Wahyuningsih, S.

2018-03-01

This experiment investigated the effect of betaine supplementation to low methionine diet on egg quality of quails. A total of 340 laying quails (Coturnix coturnix japonica) was divided into 4 dietary treatments with 5 replicates of 17 quails each. The experiment was assigned in a completely randomized design. The four dietary treatments were the low methionine diet (0.3% methionine) without betaine supplementation and the low methionine diet supplemented with 0.07, 0.14, and 0.21% betaine. The experimental diets were applied for 8 weeks and the egg quality traits were measured at the age of 16 and 20 weeks. The data were subjected to analysis of variance, and when the treatment indicated significant effect, it was continued to orthogonal polynomial test to determine the optimum level of betaine. Increasing dietary levels of betaine increased the fat content of the egg with the linear regression of y = 11.0949 + 4.1914x (R2 = 0.18). However, supplementation of betaine did not affect protein content, yolk, albumen, and eggshell percentage. It can be concluded that betaine supplementation up to 0.21% to low methionine diet only had little effect in improving the quality traits of quail eggs.

Association of betaine with blood pressure in dialysis patients.

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Wang, Lulu; Zhao, Mingming; Liu, Wenjin; Li, Xiurong; Chu, Hong; Bai, Youwei; Sun, Zhuxing; Gao, Chaoqing; Zheng, Lemin; Yang, Junwei

2018-02-01

Mechanisms underlying elevated blood pressure in dialysis patients are complex as a variety of non-traditional factors are involved. We sought to explore the association of circulating betaine, a compound widely distributed in food, with blood pressure in dialysis patients. We used baseline data of an ongoing cohort study involving patients on hemodialysis. Plasma betaine was measured by high performance liquid chromatography in 327 subjects. Blood pressure level was determined by intradialytic ambulatory blood pressure monitoring. The mean age of the patients was 52.6 ± 11.9 years, and 58.4% were male. Average interdialytic ambulatory systolic and diastolic blood pressure were 138.4 ± 22.7 mm Hg and 84.4 ± 12.5 mm Hg, respectively. Mean plasma betaine level was 37.6 μmol/L. Multiple linear regression analysis revealed significant associations of betaine with both systolic blood pressure (β = -3.66, P = .003) and diastolic blood pressure (β = -2.00, P = .004). The associations persisted even after extensive adjustment for cardiovascular covariates. Subgroup analysis revealed that the association between betaine and blood pressure was mainly limited to female patients. Our data suggest that alteration of circulating betaine possibly contributes to blood pressure regulation in these patients. ©2018 Wiley Periodicals, Inc.

Homocysteine and cerebrovascular accidents.

Science.gov (United States)

Datta, Saikat; Pal, Salil K; Mazumdar, Hirak; Bhandari, Biswanath; Bhattacherjee, Sharmistha; Pandit, Sudipta

2009-06-01

Hyperhomocysteinaemia is rapidly emerging as an important risk factor for coronary artery disease, possibly because of its propensity to accelerate atherosclerosis. Whether it is also a risk factor for cerebrovascular accidents (CVA) is a matter of debate till now, as there are conflicting results of the various prospective studies. The present study was performed to correlate the levels of plasma homocysteine levels with that of ischaemic and haemorrhagic CVA. Forty-two cases of CVA were randomly selected over a period of one year, and their risk factors were assessed. It was observed that serum homocysteine levels were significantly raised in those with intracerebral infarcts when compared to those with intracerebral haemorrhage, although homocysteine levels didn't prove to be prognostically significant.

Therapeutical approach to plasma homocysteine and cardiovascular risk reduction

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Marcello Ciaccio

2008-03-01

Full Text Available Marcello Ciaccio, Giulia Bivona, Chiara BelliaDepartment of Medical Biotechnologies and Forensic Medicine, Faculty of Medicine, University of Palermo, ItalyAbstract: Homocysteine is a sulfur-containing aminoacid produced during metabolism of methionine. Since 1969 the relationship between altered homocysteine metabolism and both coronary and peripheral atherotrombosis is known; in recent years experimental evidences have shown that elevated plasma levels of homocysteine are associated with an increased risk of atherosclerosis and cardiovascular ischemic events. Several mechanisms by which elevated homocysteine impairs vascular function have been proposed, including impairment of endothelial function, production of reactive oxygen species (ROS and consequent oxidation of low-density lipids. Endothelial function is altered in subjects with hyperhomocysteinemia, and endothelial dysfunction is correlated with plasma levels of homocysteine. Folic acid and B vitamins, required for remethylation of homocysteine to methionine, are the most important dietary determinants of homocysteine and daily supplementation typically lowers plasma homocysteine levels; it is still unclear whether the decreased plasma levels of homocysteine through diet or drugs may be paralleled by a reduction in cardiovascular risk.Keywords: homocysteine, MTHFR, cardiovascular disease, folate, B vitamin

Homocyst(e)ine impairs endocardial endothelial function.

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Tyagi, S C; Smiley, L M; Mujumdar, V S

1999-12-01

Homocyst(e)ine injured vascular endothelium and modulated endothelial-dependent vascular function. Endothelium plays an analogous role in both the vessel and the endocardium. Therefore, we hypothesized that homocyst(e)ine modulated endocardial endothelium (EE) dependent cardiac function. The ex vivo cardiac rings from normal male Wistar-Kyoto rats were prepared. The contractile responses of left and right ventricular rings were measured in an isometric myobath, using different concentrations of CaCl2. The response was higher in the left ventricle than right ventricle and was elevated in endocardium without endothelium. The half effective concentration (EC50) and maximum tension generated by homocyst(e)ine were 10(6) and 5-fold lower than endothelin (ET) and angiotensin II (AII), respectively. However, in endothelial-denuded endocardium, homocyst(e)ine response was significantly increased (pine, and endothelial nitric oxide in EE function, cardiac rings were pretreated with AII (10(-10) M) or ET (10(-13) M) and then treated with homocyst(e)ine (10(-8) M). Results suggested that at these concentrations AII, ET, or homocyst(e)ine alone had no effect on cardiac contraction. However, in the presence of 10(-10) M AII or 10(-13) M ET, the cardiac contraction to homocyst(e)ine (10(-8) M) was significantly enhanced (pine. These results suggested that homocyst(e)ine impaired EE-dependent cardiac function and acted synergistically with AII and ET in enhancing the cardiac contraction.

The O-methyltransferase PMT2 mediates methylation of pinosylvin in Scots pine.

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Paasela, Tanja; Lim, Kean-Jin; Pietiäinen, Milla; Teeri, Teemu H

2017-06-01

Heartwood extractives are important determinants of the natural durability of pine heartwood. The most important phenolic compounds affecting durability are the stilbenes pinosylvin and its monomethylether, which in addition have important functions as phytoalexins in active defense. A substantial portion of the synthesized pinosylvin is 3-methoxylated but the O-methyltransferase responsible for this modification has not been correctly identified. We studied the expression of the stilbene pathway during heartwood development as well as in response to wounding of xylem and UV-C treatment of needles. We isolated and enzymatically characterized a novel O-methyltransferase, PMT2. The methylated product was verified as pinosylvin monomethylether using ultra performance liquid chromatography-tandem mass spectrometry and high performance liquid chromatography analyses. The PMT2 enzyme was highly specific for stilbenes as substrate, in contrast to caffeoyl-CoA O-methyltransferase (CCoAOMT) and PMT1 that were multifunctional. Expression profile and multifunctional activity of CCoAOMT suggest that it might have additional roles outside lignin biosynthesis. PMT1 is not involved in the stilbene pathway and its biological function remains an open question. We isolated a new specific O-methyltransferase responsible for 3-methoxylation of pinosylvin. Expression of PMT2 closely follows stilbene biosynthesis during developmental and stress induction. We propose that PMT2 is responsible for pinosylvin methylation in Scots pine (Pinus sylvestris), instead of the previously characterized methyltransferase, PMT1. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Neuroprotection and mechanisms of atractylenolide III in preventing learning and memory impairment induced by chronic high-dose homocysteine administration in rats.

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Zhao, H; Ji, Z-H; Liu, C; Yu, X-Y

2015-04-02

Studies demonstrated that chronic high-dose homocysteine administration induced learning and memory impairment in animals. Atractylenolide III (Aen-III), a neuroprotective constituent of Atractylodis macrocephalae Koidz, was isolated in our previous study. In this study, we investigated potential benefits of Aen-III in preventing learning and memory impairment following chronic high-dose homocysteine administration in rats. Results showed that administration of Aen-III significantly ameliorated learning and memory impairment induced by chronic high-dose homocysteine administration in rats, decreased homocysteine-induced reactive oxygen species (ROS) formation and restored homocysteine-induced decrease of phosphorylated protein kinase C expression level. Moreover, Aen-III protected primary cultured neurons from apoptotic death induced by homocysteine treatment. This study provides the first evidence for the neuroprotective effect of Aen-III in preventing learning and impairment induced by chronic administration of homocysteine. Aen-III may have therapeutic potential in treating homocysteine-mediated cognitive impairment and neuronal injury. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

The relationship between maternal and neonatal umbilical cord plasma homocyst(e)ine suggests a potential role for maternal homocyst(e)ine in fetal metabolism.

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Malinow, M R; Rajkovic, A; Duell, P B; Hess, D L; Upson, B M

1998-02-01

Data on fetal blood homocyst(e)ine concentrations are not available. We tested the hypothesis that homocyst(e)ine crosses the maternal/placental/fetal interphases and is sequestered by the fetus. The concentration of homocyst(e)ine was determined at parturition in peripheral venous plasma from 35 nulliparous healthy pregnant women and umbilical arterial and venous plasma from their conceptus. Findings demonstrated a descending concentration gradient of plasma homocyst(e)ine from maternal vein to umbilical vein and to umbilical artery; the decrease at each interphase approximated 1 micromol/L. The neonate weight and gestational age were inversely related to maternal homocyst(e)ine concentrations. The umbilical vein to umbilical artery homocyst(e)ine decrement suggests that uptake of homocyst(e)ine occurs in the fetus. The likely incorporation of homocyst(e)ine into the fetal metabolic cycle may implicate maternal homocyst(e)ine as having a potential nutritional role in the fetus. Further studies are required to explain the role of homocyst(e)ine in fetal metabolism and development.

Epigenetic changes of Arabidopsis genome associated with altered DNA methyltransferase and demethylase expressions after gamma irradiation

International Nuclear Information System (INIS)

Kim, Ji Eun; Cho, Eun Ju; Kim, Ji Hong; Chung, Byung Yeoup; Kim, Jin Hong

2012-01-01

DNA methylation at carbon 5 of cytosines is a hall mark of epigenetic inactivation and heterochromatin in both plants and mammals. In Arabidopsis, DNA methylation has two roles that protect the genome from selfish DNA elements and regulate gene expression. Plant genome has three types of DNA methyltransferase, METHYLTRANSFERASE 1 (MET1), DOMAINREARRANGED METHYLASE (DRM) and CHROMOMETHYLASE 3 (CMT3) that are capable of methylating CG, CHG (where H is A, T, or C) and CHH sites, respectively. MET1 is a maintenance DNA methyltransferase that controls CG methylation. Two members of the DRM family, DRM1 and DRM2, are responsible for de novo methylation of CG, CHG, and CHH sites but show a preference for CHH sites. Finally, CMT3 principally carries out CHG methylation and is involved in both de novo methylation and maintenance. Alternatively, active DNA demethylation may occur through the glycosylase activity by removing the methylcytosines from DNA. It may have essential roles in preventing transcriptional silencing of transgenes and endogenous genes and in activating the expression of imprinted genes. DNA demetylation in Arabidopsis is mediated by the DEMETER (DME) family of bifunctional DNA glycosylase. Three targets of DME are MEA (MEDEA), FWA (FLOWERING WAGENINGEN), and FIS2 (FERTILIZATION INDEPENDENT SEED 2). The DME family contains DEMETER-LIKE 2 (DML2), DML3, and REPRESSOR OF SILENING 1 (ROS1). DNA demetylation by ROS1, DML2, and DML3 protect the hypermethylation of specific genome loci. ROS1 is necessary to suppress the promoter methylation and the silencing of endogenous genes. In contrast, the function of DML2 and DML3 has not been reported. Several recent studies have suggested that epigenetic alterations such as change in DNA methylation and histone modification should be caused in plant genomes upon exposure to ionizing radiation. However, there is a lack of data exploring the underlying mechanisms. Therefore, the present study aims to characterize and

Epigenetic changes of Arabidopsis genome associated with altered DNA methyltransferase and demethylase expressions after gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Eun; Cho, Eun Ju; Kim, Ji Hong; Chung, Byung Yeoup; Kim, Jin Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

DNA methylation at carbon 5 of cytosines is a hall mark of epigenetic inactivation and heterochromatin in both plants and mammals. In Arabidopsis, DNA methylation has two roles that protect the genome from selfish DNA elements and regulate gene expression. Plant genome has three types of DNA methyltransferase, METHYLTRANSFERASE 1 (MET1), DOMAINREARRANGED METHYLASE (DRM) and CHROMOMETHYLASE 3 (CMT3) that are capable of methylating CG, CHG (where H is A, T, or C) and CHH sites, respectively. MET1 is a maintenance DNA methyltransferase that controls CG methylation. Two members of the DRM family, DRM1 and DRM2, are responsible for de novo methylation of CG, CHG, and CHH sites but show a preference for CHH sites. Finally, CMT3 principally carries out CHG methylation and is involved in both de novo methylation and maintenance. Alternatively, active DNA demethylation may occur through the glycosylase activity by removing the methylcytosines from DNA. It may have essential roles in preventing transcriptional silencing of transgenes and endogenous genes and in activating the expression of imprinted genes. DNA demetylation in Arabidopsis is mediated by the DEMETER (DME) family of bifunctional DNA glycosylase. Three targets of DME are MEA (MEDEA), FWA (FLOWERING WAGENINGEN), and FIS2 (FERTILIZATION INDEPENDENT SEED 2). The DME family contains DEMETER-LIKE 2 (DML2), DML3, and REPRESSOR OF SILENING 1 (ROS1). DNA demetylation by ROS1, DML2, and DML3 protect the hypermethylation of specific genome loci. ROS1 is necessary to suppress the promoter methylation and the silencing of endogenous genes. In contrast, the function of DML2 and DML3 has not been reported. Several recent studies have suggested that epigenetic alterations such as change in DNA methylation and histone modification should be caused in plant genomes upon exposure to ionizing radiation. However, there is a lack of data exploring the underlying mechanisms. Therefore, the present study aims to characterize and

Levels of Key Enzymes of Methionine-Homocysteine Metabolism in Preeclampsia

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Alejandra Pérez-Sepúlveda

2013-01-01

Full Text Available Objective. To evaluate the role of key enzymes in the methionine-homocysteine metabolism (MHM in the physiopathology of preeclampsia (PE. Methods. Plasma and placenta from pregnant women (32 controls and 16 PE patients were analyzed after informed consent. Protein was quantified by western blot. RNA was obtained with RNA purification kit and was quantified by reverse transcritase followed by real-time PCR (RT-qPCR. Identification of the C677T and A1298C methylenetetrahydrofolate reductase (MTHFR single-nucleotide polymorphisms (SNPs and A2756G methionine synthase (MTR SNP was performed using PCR followed by a high-resolution melting (HRM analysis. S-adenosyl methionine (SAM and S-adenosyl homocysteine (SAH were measured in plasma using high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS. The SNP association analysis was carried out using Fisher’s exact test. Statistical analysis was performed using a Mann-Whitney test. Results. RNA expression of MTHFR and MTR was significantly higher in patients with PE as compared with controls. Protein, SAM, and SAH levels showed no significant difference between preeclamptic patients and controls. No statistical differences between controls and PE patients were observed with the different SNPs studied. Conclusion. The RNA expression of MTHFR and MTR is elevated in placentas of PE patients, highlighting a potential compensation mechanism of the methionine-homocysteine metabolism in the physiopathology of this disease.

DACH-LIGA homocystein (german, austrian and swiss homocysteine society): consensus paper on the rational clinical use of homocysteine, folic acid and B-vitamins in cardiovascular and thrombotic diseases: guidelines and recommendations.

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Stanger, Olaf; Herrmann, Wolfgang; Pietrzik, Klaus; Fowler, Brian; Geisel, Jürgen; Dierkes, Jutta; Weger, Martin

2003-11-01

About half of all deaths are due to cardiovascular disease and its complications. The economic burden on society and the healthcare system from cardiovascular disability, complications, and treatments is huge and getting larger in the rapidly aging populations of developed countries. As conventional risk factors fail to account for part of the cases, homocysteine, a "new" risk factor, is being viewed with mounting interest. Homocysteine is a sulfur-containing intermediate product in the normal metabolism of methionine, an essential amino acid. Folic acid, vitamin B12, and vitamin B6 deficiencies and reduced enzyme activities inhibit the breakdown of homocysteine, thus increasing the intracellular homocysteine concentration. Numerous retrospective and prospective studies have consistently found an independent relationship between mild hyperhomocysteinemia and cardiovascular disease or all-cause mortality. Starting at a plasma homocysteine concentration of approximately 10 micromol/l, the risk increase follows a linear dose-response relationship with no specific threshold level. Hyperhomocysteinemia as an independent risk factor for cardiovascular disease is thought to be responsible for about 10% of total risk. Elevated plasma homocysteine levels (>12 micromol/l; moderate hyperhomocysteinemia) are considered cytotoxic and are found in 5 to 10% of the general population and in up to 40% of patients with vascular disease. Additional risk factors (smoking, arterial hypertension, diabetes, and hyperlipidemia) may additively or, by interacting with homocysteine, synergistically (and hence over-proportionally) increase overall risk. Hyperhomocysteinemia is associated with alterations in vascular morphology, loss of endothelial anti-thrombotic function, and induction of a procoagulant environment. Most known forms of damage or injury are due to homocysteine-mediated oxidative stress. Especially when acting as direct or indirect antagonists of cofactors and enzyme

S-adenosyl-L-(l-14C)-homocysteine

International Nuclear Information System (INIS)

Thomas, H.J.; Montgomery, J.A.

1987-01-01

S-Adenosyl-L-(1- 14 C)-homocysteine was prepared from commercially available L-(1- 14 C)-methionine by conversion first to S-benzyl-L-(1- 14 C)-homocysteine which upon treatment with sodium in liquid ammonia gave the disodium salt of L-(1- 14 C)-homocysteine. Reaction of this sodium salt with 5'-O-tosyladenosine gave the title compound. (author)

SULPHUR-CONTAINING AMINO ACIDS METABOLISM IN EXPERIMENTAL HYPER- AND HYPOTHYROIDISM IN RATS.

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Nechiporuk, V; Zaichko, N; Korda, М; Melnyk, A; Koloshko, O

2017-10-01

Hyper- and hypothyroidism are some of the most common endocrinopathies that cause many metabolic disorders including amino acids metabolism. However, a specific molecular mechanism of thyroid hormones influence on sulphur-containing amino acids metabolism has not been established. The aim of our research was to investigate experimentally the influence of thyroid gland functional state on the main enzymatic systems of sulphur-containing amino acids metabolism in liver and kidneys, the content of homocysteine, cysteine and H2S in blood. The rats were administered with L-thyroxine and mercazolil to simulate the states of hyper- and hypothyroidism, which were confirmed by the content of fT3, fT4 and TSH in the blood. In liver and kidneys of the animals with hypothyroidism we observed the decrease in the activity of enzymes of remethylation cycle of S-adenosylmethioninsyntase, S-adenosylhomocysteinhyhdrolase, betaine-homocysteine methyltransferase. Suppression of transsulfuration transformation of homocysteine to cysteine in hypothyroidism was mainly due to the inhibition of cystathionine synthase activity of cystathionine-β-synthase, wherein cystathionase activity of cystathionine-γ-lyase was not changed. In animals with hypothyroidism we also noticed the inhibition of cysteine desulfunation reactions: the activity of enzymes of cystathionine-β-synthase, cystathionine-γ-lyase and cysteine aminotransferase significantly decreased in liver and kidneys. Experimental hyperthyroidism was accompanied by increase in activity of remethylation cycle enzymes, increase in cystationine synthase activity of cystathionine-β-synthase in liver and activity of these enzymes in kidneys. The simulation of hyperthyroidism led to the decrease of homocysteine concentration, and of hypothyroidism - to the increase of homocysteine and cysteine concentrations and reduced H2S content in blood of the animals. Thus, the significant risk factors for the development of atherosclerosis

The Roles of Two miRNAs in Regulating the Immune Response of Sea Cucumber.

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Zhang, Pengjuan; Li, Chenghua; Zhang, Ran; Zhang, Weiwei; Jin, Chunhua; Wang, Lingling; Song, Linsheng

2015-12-01

MicroRNAs (miRNAs) have emerged as key regulators in many pathological processes by suppressing the transcriptional and post-transcriptional expression of target genes. MiR-2008 was previously found to be significantly up-regulated in diseased sea cucumber Apostichopus japonicus by high-through sequencing, whereas the reads of miR-137, a well-documented tumor repressor, displayed no significant change. In the present study, we found that miR-137 expression was slightly attenuated and miR-2008 was significantly enhanced after Vibrio splendidus infection or Lipopolysaccharides application. Further target screening and dual-luciferase reporter assay revealed that the two important miRNAs shared a common target gene of betaine-homocysteine S-methyltransferase (AjBHMT), which exhibited noncorrelated messenger RNA and protein expression patterns after bacterial challenge. In order to fully understand their regulatory mechanisms, we conducted the functional experiments in vitro and in vivo. The overexpression of miR-137 in sea cucumber or primary coelomocytes significantly decreased, whereas the inhibition of miR-137 increased the mRNA and protein expression levels of AjBHMT. In contrast, miR-2008 overexpression and inhibition showed no effect on AjBHMT mRNA levels, but the concentration of AjBHMT protein displayed significant changes both in vitro and in vivo. Consistently, the homocysteine (Hcy) contents were also accordingly altered in the aberrant expression analysis of both miRNAs, consistent with the results of the AjBHMT silencing assay in vitro and in vivo. More importantly, small interfering RNA mediated AjBHMT knockdown and Hcy exposure analyses both significantly increased reactive oxygen species (ROS) production and decreased the number of surviving invasive pathogen in sea cucumber coelomocytes. Taken together, these findings confirmed the differential roles of sea cucumber miR-137 and miR-2008 in regulating the common target AjBHMT to promote ROS production

[Gene cloning and bioinformatics analysis of SABATH methyltransferase in Lonicera japonica var. chinensis].

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Yu, Xiao-Dan; Jiang, Chao; Huang, Lu-Qi; Qin, Shuang-Shuang; Zeng, Xiang-Mei; Chen, Ping; Yuan, Yuan

2013-08-01

To clone SABATH methyltransferase (rLjSABATHMT) gene in Lonicera japonica var. chinensis, and compare the gene expression and intron sequence of SABATH methyltransferase orthologous in L. japonica with L. japonica var. chinensis. It provide a basis for gene regulate the formation of L. japonica floral scents. The cDNA and genome sequences of LjSABATHMT from L. japonica var. chinensis were cloned according to the gene fragments in cDNA library. The LjSABATHMT protein was characterized by bioinformatics analysis. SABATH family phylogenetic tree were built by MEGA 5.0. The transcripted level of SABATHMT orthologous were analyzed in different organs and different flower periods of L. japonica and L. japonica var. chinensis using RT-PCR analysis. Intron sequences of SABATHMT orthologous were also analyzied. The cDNA of LjSABATHMT was 1 251 bp, had a complete coding frame with 365 amino acids. The protein had the conservative SABATHMT domain, and phylogenetic tree showed that it may be a salicylic acid/benzoic acid methyltransferase. Higher expression of SABATH methyltransferase orthologous was found in flower. The intron sequence of L. japonica and L. japonica var. chinensis had rich polymorphism, and two SNP are unique genotype of L. japonica var. chinensis. The motif elements in two orthologous genes were significant differences. The intron difference of SABATH methyltransferase orthologous could be inducing to difference of gene expression between L. japonica and L. japonica var. chinensis. These results will provide important base on regulating active compounds of L. japonica.

The role of Homocysteine as a predictor for coronary heart disease

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Schramm, Susanne

2007-11-01

analyse the association of homocysteine plasma levels with future cardiac events in probands without pre-existing coronary heart disease or in population-based samples. To answer the second question, a systematic overview of the literature is prepared, including randomised controlled trials and systematic reviews of randomised controlled trials that determine the effectiveness of homocysteine lowering therapy for the prevention of cardiac events. To answer the third question, economic evaluations of homocysteine testing for preventive purposes are analysed. Methodological quality of all materials is assessed by widely accepted instruments, evidence was summarized qualitatively. Results: For the first question eleven systematic reviews and 33 single studies (prospective cohort studies and nested case control studies are available. Among the studies there is profound heterogeneity concercing study populations, classification of exposure (homocysteine measurements, units to express “elevation”, outcome definition and measurement, as well as controlling for confounding (qualitatively and quantitatively. Taking these heterogeneities into consideration, metaanalysis of single patient data with controlling for multiple confounders seems to be the only adequate method of summarizing the results of single studies. The only available analysis of this type shows, that in otherwise healthy people homocysteine plasma levels are only a very weak predictor of future cardiac events. The predictive value of the classical risk factors is much stronger. Among the studies that actively exclude patients with pre-existing coronary heart disease, there are no reports of an association between elevated homocysteine plasma levels and future cardiac events. Eleven randomized controlled trials (ten of them reported in one systematic review are analysed in order to answer the second question. All trials include high risk populations for the development of (further cardiac events. These studies

Homocysteine metabolism and risk of schizophrenia

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Muntjewerff, J.W.

2006-01-01

The one-carbon cycle hypothesis initiated research of schizophrenia risk in relation to sensitive markers of aberrant homocysteine metabolism, such as B-vitamin concentrations, plasma total homocysteine (tHcy) concentrations, and genetic determinants. We observed decreased plasma and elevated RBC

Homocysteine Test

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... needed to ensure the quality of the sample? Fasting for 10 to 12 hours may be required ... factors, such as smoking, high blood pressure , or obesity. However, the exact role that homocysteine plays in ...

Floral Benzenoid Carboxyl Methyltransferases: From in Vitro to in Planta Function

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Effmert,U.; Saschenbrecker, S.; Ross, J.; Negre, F.; Fraser, C.; Noel, J.; Dudareva, N.; Piechulla, B.

2005-01-01

Benzenoid carboxyl methyltransferases synthesize methyl esters (e.g., methyl benzoate and methyl salicylate), which are constituents of aromas and scents of many plant species and play important roles in plant communication with the surrounding environment. Within the past five years, eleven such carboxyl methyltransferases were isolated and most of them were comprehensively investigated at the biochemical, molecular and structural level. Two types of enzymes can be distinguished according to their substrate preferences: the SAMT-type enzymes isolated from Clarkia breweri, Stephanotis floribunda, Antirrhinum majus, Hoya carnosa, and Petunia hybrida, which have a higher catalytic efficiency and preference for salicylic acid, while BAMT-type enzymes from A. majus, Arabidopsis thaliana, Arabidopsis lyrata, and Nicotiana suaveolens prefer benzoic acid. The elucidation of C. breweri SAMT's three-dimensional structure allowed a detailed modelling of the active sites of the carboxyl methyltransferases and revealed that the SAM binding pocket is highly conserved among these enzymes while the methyl acceptor binding site exhibits some variability, allowing a classification into SAMT-type and BAMT-type enzymes. The analysis of expression patterns coupled with biochemical characterization showed that these carboxyl methyltransferases are involved either in floral scent biosynthesis or in plant defense responses. While the latter can be induced by biotic or abiotic stress, the genes responsible for floral scent synthesis exhibit developmental and rhythmic expression pattern. The nature of the product and efficiency of its formation in plants depend on the availability of substrates, the catalytic efficiency of the enzyme toward benzoic acid and/or salicylic acid, and the transcriptional, translational, and post-translational regulation at the enzyme level. The biochemical properties of benzenoid carboxyl methyltransferases suggest that the genes involved in plant defenses

INFLUENCE OF BETAINE ON GOAT MILK YIELD AND BLOOD METABOLITES

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Carlos Javier Fernandez

2009-02-01

Full Text Available Betaine is a natural occurring compound with methyl donor properties which is increasingly being used in animal feeding. Betaine, an oxidative product of choline is able to replace methionine in some physiologically important body processes. The subject of this work was to study the effect of betaine added to the diet on milk production and blood metabolites on Murciano-Granadina dairy goats.  Sixty lactating goats were selected from a commercial Murciano-Granadina goat herd (EXCAMUR S.L. located in Murcia Region (Spain. Goats were selected from a 250 goats herd, taken  into account the age, stage of lactation (2.5 as average, live weight (36 kg as average and type of birth (2 kids. Two homogenous groups of 30 goats were made and fed with 1.5 kg of compound feed and 1 kg of alfalfa hay per day and goat. Goats were fed twice a day and water was provided ad libitum. Both groups received the same diet but for the second group the diet was supplemented with 4 g∙kg-1 betaine (betaine anhydrous, Danisco Animal Nutrition. The feeds, presented in pellets, were formulated in based on recommendations of INRA (2007. The experimental period was 6 months and the experimental diets were provided 15 days before parturition. The herd was machine milked once at day. Chemical composition, milk production and blood metabolites of each goat were recorded and analyzed at the end of the trial. Variance analysis and means comparison were carried out using the general lineal model procedure and Tukey test for mean comparison. Goats fed with betaine diet had higher milk fat than goats fed control diet (4.8 vs. 5.2 % for control and betaine respectively; P

Anodic Aluminum Oxide Membrane-Assisted Fabrication of beta-In(2)S(3) Nanowires.

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Shi, Jen-Bin; Chen, Chih-Jung; Lin, Ya-Ting; Hsu, Wen-Chia; Chen, Yu-Cheng; Wu, Po-Feng

2009-06-06

In this study, beta-In(2)S(3) nanowires were first synthesized by sulfurizing the pure Indium (In) nanowires in an AAO membrane. As FE-SEM results, beta-In(2)S(3) nanowires are highly ordered, arranged tightly corresponding to the high porosity of the AAO membrane used. The diameter of the beta-In(2)S(3) nanowires is about 60 nm with the length of about 6-8 mum. Moreover, the aspect ratio of beta-In(2)S(3) nanowires is up to 117. An EDS analysis revealed the beta-In(2)S(3) nanowires with an atomic ratio of nearly S/In = 1.5. X-ray diffraction and corresponding selected area electron diffraction patterns demonstrated that the beta-In(2)S(3) nanowire is tetragonal polycrystalline. The direct band gap energy (E(g)) is 2.40 eV from the optical measurement, and it is reasonable with literature.

Riboflavin-responsive trimethylaminuria in a patient with homocystinuria on betaine therapy.

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Manning, Nigel J; Allen, Elizabeth K; Kirk, Richard J; Sharrard, Mark J; Smith, Edwin J

2012-01-01

A 17-year-old female patient with pyridoxine non-responsive homocystinuria, treated with 20 g of betaine per day, developed a strong body odour, which was described as fish-like. Urinary trimethylamine (TMA) was measured and found to be markedly increased. DNA mutation analysis revealed homozygosity for a common allelic variant in the gene coding for the TMA oxidising enzyme FMO3. Without changing diet or betaine therapy, riboflavin was given at a dose of 200 mg per day. An immediate improvement in her odour was noticed by her friends and family and urinary TMA was noted to be greatly reduced, although still above the normal range.Gradual further reductions in TMA (and odour) have followed whilst receiving riboflavin. Throughout this period, betaine compliance has been demonstrated by the measurement of dimethylglycine (DMG) excretion, which has been consistently increased. Marked excretions of DMG when the odour had subsided also demonstrate that DMG was not the source of the odour.This patient study raises the possibility that betaine may be converted to TMA by intestinal flora to some degree, resulting in a significant fish odour when oxidation of TMA is compromised by FMO3 variants. The possibility exists that the body odour occasionally associated with betaine therapy for homocystinuria may not be related to increased circulating betaine or DMG, but due to a common FMO3 mutation resulting in TMAU. Benefits of riboflavin therapy for TMAU for such patients would allow the maintenance of betaine therapy without problematic body odour.

Dynamic regulation of hepatic lipid droplet properties by diet.

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Crunk, Amanda E; Monks, Jenifer; Murakami, Aya; Jackman, Matthew; Maclean, Paul S; Ladinsky, Mark; Bales, Elise S; Cain, Shannon; Orlicky, David J; McManaman, James L

2013-01-01

Cytoplasmic lipid droplets (CLD) are organelle-like structures that function in neutral lipid storage, transport and metabolism through the actions of specific surface-associated proteins. Although diet and metabolism influence hepatic CLD levels, how they affect CLD protein composition is largely unknown. We used non-biased, shotgun, proteomics in combination with metabolic analysis, quantitative immunoblotting, electron microscopy and confocal imaging to define the effects of low- and high-fat diets on CLD properties in fasted-refed mice. We found that the hepatic CLD proteome is distinct from that of CLD from other mammalian tissues, containing enzymes from multiple metabolic pathways. The hepatic CLD proteome is also differentially affected by dietary fat content and hepatic metabolic status. High fat feeding markedly increased the CLD surface density of perilipin-2, a critical regulator of hepatic neutral lipid storage, whereas it reduced CLD levels of betaine-homocysteine S-methyltransferase, an enzyme regulator of homocysteine levels linked to fatty liver disease and hepatocellular carcinoma. Collectively our data demonstrate that the hepatic CLD proteome is enriched in metabolic enzymes, and that it is qualitatively and quantitatively regulated by diet and metabolism. These findings implicate CLD in the regulation of hepatic metabolic processes, and suggest that their properties undergo reorganization in response to hepatic metabolic demands.

Overexpression of ALDH10A8 and ALDH10A9 Genes Provides Insight into Their Role in Glycine Betaine Synthesis and Affects Primary Metabolism in Arabidopsis thaliana.

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Missihoun, Tagnon D; Willée, Eva; Guegan, Jean-Paul; Berardocco, Solenne; Shafiq, Muhammad R; Bouchereau, Alain; Bartels, Dorothea

2015-09-01

Betaine aldehyde dehydrogenases oxidize betaine aldehyde to glycine betaine in species that accumulate glycine betaine as a compatible solute under stress conditions. In contrast, the physiological function of betaine aldehyde dehydrogenase genes is at present unclear in species that do not accumulate glycine betaine, such as Arabidopsis thaliana. To address this question, we overexpressed the Arabidopsis ALDH10A8 and ALDH10A9 genes, which were identified to code for betaine aldehyde dehydrogenases, in wild-type A. thaliana. We analysed changes in metabolite contents of transgenic plants in comparison with the wild type. Using exogenous or endogenous choline, our results indicated that ALDH10A8 and ALDH10A9 are involved in the synthesis of glycine betaine in Arabidopsis. Choline availability seems to be a factor limiting glycine betaine synthesis. Moreover, the contents of diverse metabolites including sugars (glucose and fructose) and amino acids were altered in fully developed transgenic plants compared with the wild type. The plant metabolic response to salt and the salt stress tolerance were impaired only in young transgenic plants, which exhibited a delayed growth of the seedlings early after germination. Our results suggest that a balanced expression of the betaine aldehyde dehydrogenase genes is important for early growth of A. thaliana seedlings and for salt stress mitigation in young seedlings. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Study of the Effects of Betaine and/or C-Phycocyanin on the Growth of Lung Cancer A549 Cells In Vitro and In Vivo

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Rea Bingula

2016-01-01

Full Text Available We investigated the effects of betaine, C-phycocyanin (C-PC, and their combined use on the growth of A549 lung cancer both in vitro and in vivo. When cells were coincubated with betaine and C-PC, an up to 60% decrease in viability was observed which is significant compared to betaine (50% or C-PC treatment alone (no decrease. Combined treatment reduced the stimulation of NF-κB expression by TNF-α and increased the amount of the proapoptotic p38 MAPK. Interestingly, combined treatment induced a cell cycle arrest in G2/M phase for ~60% of cells. In vivo studies were performed in pathogen-free male nude rats injected with A549 cells in their right flank. Their daily food was supplemented with either betaine, C-PC, both, or neither. Compared to the control group, tumour weights and volumes were significantly reduced in either betaine- or C-PC-treated groups and no additional decrease was obtained with the combined treatment. This data indicates that C-PC and betaine alone may efficiently inhibit tumour growth in rats. The synergistic activity of betaine and C-PC on A549 cells growth observed in vitro remains to be further confirmed in vivo. The reason behind the nature of their interaction is yet to be sought.

Arabidopsis DNA methyltransferase AtDNMT2 associates with histone deacetylase AtHD2s activity

International Nuclear Information System (INIS)

Song, Yuan; Wu, Keqiang; Dhaubhadel, Sangeeta; An, Lizhe; Tian, Lining

2010-01-01

DNA methyltransferase2 (DNMT2) is always deemed to be enigmatic, because it contains highly conserved DNA methyltransferase motifs but lacks the DNA methylation catalytic capability. Here we show that Arabidopsis DNA methyltransferase2 (AtDNMT2) is localized in nucleus and associates with histone deacetylation. Bimolecular fluorescence complementation and pull-down assays show AtDNMT2 interacts with type-2 histone deacetylases (AtHD2s), a unique type of histone deacetylase family in plants. Through analyzing the expression of AtDNMT2: ss-glucuronidase (GUS) fusion protein, we demonstrate that AtDNMT2 has the ability to repress gene expression at transcription level. Meanwhile, the expression of AtDNMT2 gene is altered in athd2c mutant plants. We propose that AtDNMT2 possibly involves in the activity of histone deacetylation and plant epigenetic regulatory network.

Arabidopsis DNA methyltransferase AtDNMT2 associates with histone deacetylase AtHD2s activity

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Song, Yuan [Key Laboratory of Arid and Grassland Agroecology, Ministry of Education, School of Life Science, Lanzhou University, Lanzhou 730000 (China); Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, Canada N5V4T3 (Canada); Wu, Keqiang [Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan (China); Dhaubhadel, Sangeeta [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, Canada N5V4T3 (Canada); An, Lizhe, E-mail: lizhean@lzu.edu.cn [Key Laboratory of Arid and Grassland Agroecology, Ministry of Education, School of Life Science, Lanzhou University, Lanzhou 730000 (China); Tian, Lining, E-mail: tianl@agr.gc.ca [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON, Canada N5V4T3 (Canada)

2010-05-28

DNA methyltransferase2 (DNMT2) is always deemed to be enigmatic, because it contains highly conserved DNA methyltransferase motifs but lacks the DNA methylation catalytic capability. Here we show that Arabidopsis DNA methyltransferase2 (AtDNMT2) is localized in nucleus and associates with histone deacetylation. Bimolecular fluorescence complementation and pull-down assays show AtDNMT2 interacts with type-2 histone deacetylases (AtHD2s), a unique type of histone deacetylase family in plants. Through analyzing the expression of AtDNMT2: ss-glucuronidase (GUS) fusion protein, we demonstrate that AtDNMT2 has the ability to repress gene expression at transcription level. Meanwhile, the expression of AtDNMT2 gene is altered in athd2c mutant plants. We propose that AtDNMT2 possibly involves in the activity of histone deacetylation and plant epigenetic regulatory network.

Niacin treatment increases plasma homocyst(e)ine levels.

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Garg, R; Malinow, M; Pettinger, M; Upson, B; Hunninghake, D

1999-12-01

Studies have reported high levels of plasma homocyst(e)ine as an independent risk factor for arterial occlusive disease. The Cholesterol Lowering Atherosclerosis Study reported an increase in plasma homocyst(e)ine levels in patients receiving both colestipol and niacin compared with placebo. Thus the objective of this study was to examine the effect of niacin treatment on plasma homocyst(e)ine levels. The Arterial Disease Multiple Intervention Trial, a multicenter randomized, placebo-controlled trial, examined the effect of niacin compared with placebo on homocyst(e)ine in a subset of 52 participants with peripheral arterial disease. During the screening phase, titration of niacin dose from 100 mg to 1000 mg daily resulted in a 17% increase in mean plasma homocyst(e)ine level from 13.1 +/- 4.4 micromol/L to 15.3 +/- 5.6 micromol/L (P ine levels in the niacin group and a 7% decrease in the placebo group (P =.0001). This difference remained statistically significant at the end of follow-up at 48 weeks. Niacin substantially increased plasma homocyst(e)ine levels, which could potentially reduce the expected benefits of niacin associated with lipoprotein modification. However, plasma homocyst(e)ine levels can be decreased by folic acid supplementation. Thus further studies are needed to determine whether B vitamin supplementation to patients undergoing long-term niacin treatment would be beneficial.

Structural Basis of Substrate Recognition in Thiopurine S-Methyltransferase

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Peng, Yi; Feng, Qiping; Wilk, Dennis; Adjei, Araba A.; Salavaggione, Oreste E.; Weinshilboum, Richard M.; Yee, Vivien C. (Case Western); (MCCM)

2008-09-23

Thiopurine S-methyltransferase (TPMT) modulates the cytotoxic effects of thiopurine prodrugs such as 6-mercaptopurine by methylating them in a reaction using S-adenosyl-l-methionine as the donor. Patients with TPMT variant allozymes exhibit diminished levels of protein and/or enzyme activity and are at risk for thiopurine drug-induced toxicity. We have determined two crystal structures of murine TPMT, as a binary complex with the product S-adenosyl-l-homocysteine and as a ternary complex with S-adenosyl-l-homocysteine and the substrate 6-mercaptopurine, to 1.8 and 2.0 {angstrom} resolution, respectively. Comparison of the structures reveals that an active site loop becomes ordered upon 6-mercaptopurine binding. The positions of the two ligands are consistent with the expected S{sub N}2 reaction mechanism. Arg147 and Arg221, the only polar amino acids near 6-mercaptopurine, are highlighted as possible participants in substrate deprotonation. To probe whether these residues are important for catalysis, point mutants were prepared in the human enzyme. Substitution of Arg152 (Arg147 in murine TPMT) with glutamic acid decreases V{sub max} and increases K{sub m} for 6-mercaptopurine but not K{sub m} for S-adenosyl-l-methionine. Substitution at this position with alanine or histidine and similar substitutions of Arg226 (Arg221 in murine TPMT) result in no effect on enzyme activity. The double mutant Arg152Ala/Arg226Ala exhibits a decreased V{sub max} and increased K{sub m} for 6-mercaptopurine. These observations suggest that either Arg152 or Arg226 may participate in some fashion in the TPMT reaction, with one residue compensating when the other is altered, and that Arg152 may interact with substrate more directly than Arg226, consistent with observations in the murine TPMT crystal structure.

Assessment of urinary betaine as a marker of diabetes mellitus in cardiovascular patients.

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Schartum-Hansen, Hall; Ueland, Per M; Pedersen, Eva R; Meyer, Klaus; Ebbing, Marta; Bleie, Øyvind; Svingen, Gard F T; Seifert, Reinhard; Vikse, Bjørn E; Nygård, Ottar

2013-01-01

Abnormal urinary excretion of betaine has been demonstrated in patients with diabetes or metabolic syndrome. We aimed to identify the main predictors of excretion in cardiovascular patients and to make initial assessment of its feasibility as a risk marker of future diabetes development. We used data from 2396 patients participating in the Western Norway B-vitamin Intervention Trial, who delivered urine and blood samples at baseline, and in the majority at two visits during follow-up of median 39 months. Betaine in urine and plasma were measured by liquid-chromatography-tandem mass spectrometry. The strongest determinants of urinary betaine excretion by multiple regression were diabetes mellitus, age and estimated glomerular filtration rate; all pdiabetes mellitus (n = 264) had a median excretion more than three times higher than those without. We found a distinct non-linear association between urinary betaine excretion and glycated hemoglobin, with a break-point at 6.5%, and glycated hemoglobin was the strongest determinant of betaine excretion in patients with diabetes mellitus. The discriminatory power for diabetes mellitus corresponded to an area under the curve by receiver-operating characteristics of 0.82, and betaine excretion had a coefficient of reliability of 0.73. We also found a significant, independent log-linear relation between baseline betaine excretion and the risk of developing new diabetes during follow-up. The good discriminatory power for diabetes, high test-retest stability and independent association with future risk of new diabetes should motivate further investigation on the role of betaine excretion in risk assessment and long-term follow-up of diabetes mellitus.

miR-125b targets DNMT3b and mediates p53 DNA methylation involving in the vascular smooth muscle cells proliferation induced by homocysteine

Energy Technology Data Exchange (ETDEWEB)

Cao, ChengJian [Key Laboratory of Basic Research in Cardio-Cerebral Vascular Diseases, Ningxia Medical University, Yinchuan (China); Zhang, HuiPing [Department of Prenatal Diagnosis Center, General Hospital of Ningxia Medical University, Yinchuan (China); Zhao, Li [Department of Medical Laboratory, Ningxia Medical University, Yinchuan (China); Zhou, Longxia [Department of Basic Medicine, Ningxia Medical University, Yinchuan (China); Zhang, Minghao; Xu, Hua [Key Laboratory of Basic Research in Cardio-Cerebral Vascular Diseases, Ningxia Medical University, Yinchuan (China); Department of Basic Medicine, Ningxia Medical University, Yinchuan (China); Han, Xuebo [Department of Medical Laboratory, Ningxia Medical University, Yinchuan (China); Li, Guizhong; Yang, Xiaoling [Key Laboratory of Basic Research in Cardio-Cerebral Vascular Diseases, Ningxia Medical University, Yinchuan (China); Department of Basic Medicine, Ningxia Medical University, Yinchuan (China); Jiang, YiDeng, E-mail: jyjcyxy@yeah.net [Key Laboratory of Basic Research in Cardio-Cerebral Vascular Diseases, Ningxia Medical University, Yinchuan (China); Department of Basic Medicine, Ningxia Medical University, Yinchuan (China)

2016-09-10

MicroRNAs (miRNAs) are short non-coding RNA and play crucial roles in a wide array of biological processes, including cell proliferation, differentiation and apoptosis. Our previous studies found that homocysteine(Hcy) can stimulate the proliferation of vascular smooth muscle cells (VSMCs), however, the underlying mechanisms were not fully elucidated. Here, we found proliferation of VSMCs induced by Hcy was of correspondence to the miR-125b expression reduced both in vitro and in the ApoE knockout mice, the hypermethylation of p53, its decreased expression, and DNA (cytosine-5)-methyltransferase 3b (DNMT3b) up-regulated. And, we found DNMT3b is a target of miR-125b, which was verified by the Dual-Luciferase reporter assay and western blotting. Besides, the siRNA interference for DNMT3b significantly decreased the methylation level of p53, which unveiled the causative role of DNMT3b in p53 hypermethylation. miR-125b transfection further confirmed its regulative roles on p53 gene methylation status and the VSMCs proliferation. Our data suggested that a miR-125b-DNMT3b-p53 signal pathway may exist in the VSMCs proliferation induced by Hcy.

miR-125b targets DNMT3b and mediates p53 DNA methylation involving in the vascular smooth muscle cells proliferation induced by homocysteine

International Nuclear Information System (INIS)

Cao, ChengJian; Zhang, HuiPing; Zhao, Li; Zhou, Longxia; Zhang, Minghao; Xu, Hua; Han, Xuebo; Li, Guizhong; Yang, Xiaoling; Jiang, YiDeng

2016-01-01

MicroRNAs (miRNAs) are short non-coding RNA and play crucial roles in a wide array of biological processes, including cell proliferation, differentiation and apoptosis. Our previous studies found that homocysteine(Hcy) can stimulate the proliferation of vascular smooth muscle cells (VSMCs), however, the underlying mechanisms were not fully elucidated. Here, we found proliferation of VSMCs induced by Hcy was of correspondence to the miR-125b expression reduced both in vitro and in the ApoE knockout mice, the hypermethylation of p53, its decreased expression, and DNA (cytosine-5)-methyltransferase 3b (DNMT3b) up-regulated. And, we found DNMT3b is a target of miR-125b, which was verified by the Dual-Luciferase reporter assay and western blotting. Besides, the siRNA interference for DNMT3b significantly decreased the methylation level of p53, which unveiled the causative role of DNMT3b in p53 hypermethylation. miR-125b transfection further confirmed its regulative roles on p53 gene methylation status and the VSMCs proliferation. Our data suggested that a miR-125b-DNMT3b-p53 signal pathway may exist in the VSMCs proliferation induced by Hcy.

Determination of Betaine in Forsythia Suspensa by High Performance Capillary Electrophoresis

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Liu, Haixing; Dong, Guoliang; Wang, Lintong

2017-12-01

This paper presents the determination of betaine content of Forsythia suspensa by high performance capillary electrophoresis (HPCE) method. The borax solution was chosen as buffer solution, and its concentration was 40 mmol with capillary column (75μm×52/60cm) at a constant voltage of 20kV and injecting pressure time of 10s at 20°C. Linearity was kept in the concent ration range of 0.0113-1.45mg·ml-1 of betaine with correlation coefficient of 0.999. The recovery was in the range of 97%-117% (n=5), The content of betaine was 281.5 mg·g-1and RSD value of 9.6% (n=6) in Forsythia suspensa. This method has the advantage of rapid, accurate and good repeatability in separation and determination of betaine in Forsythia suspensa.

Molecular interactions in the betaine monohydrate-polyol deep eutectic solvents: Experimental and computational studies

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Zahrina, Ida; Mulia, Kamarza; Yanuar, Arry; Nasikin, Mohammad

2018-04-01

DES (deep eutectic solvents) are a new class of ionic liquids that have excellent properties. The strength of interaction between molecules in the DES affects their properties and applications. In this work, the strength of molecular interactions between components in the betaine monohydrate salt and polyol (glycerol or/and propylene glycol) eutectic mixtures was studied by experimental and computational studies. The melting point and fusion enthalpy of the mixtures were measured using STA (Simultaneous Thermal Analyzer). The nature and strength of intermolecular interactions were observed by FT-IR and NMR spectroscopy. The molecular dynamics simulation was used to determine the number of H-bonds, percent occupancy, and radial distribution functions in the eutectic mixtures. The interaction between betaine monohydrate and polyol is following order: betaine monohydrate-glycerol-propylene glycol > betaine monohydrate-glycerol > betaine monohydrate-propylene glycol, where the latter is the eutectic mixture with the lowest stability, strength and extent of the hydrogen bonding interactions between component molecules. The presence of intra-molecular hydrogen bonding interactions, the inter-molecular hydrogen bonding interactions between betaine molecule and polyol, and also interactions between polyol and H2O of betaine monohydrate in the eutectic mixtures.

Retinal Ganglion Cell Loss in Diabetes Associated with Elevated Homocysteine

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Kenneth S. Shindler

2009-11-01

Full Text Available A number of studies have suggested that homocysteine may be a contributing factor to development of retinopathy in diabetic patients based on observed correlations between elevated homocysteine levels and the presence of retinopathy. The significance of such a correlation remains to be determined, and potential mechanisms by which homocysteine might induce retinopathy have not been well characterized. Ganapathy and colleagues1 used mutant mice that have endogenously elevated homocysteine levels due to heterozygous deletion of the cystathionine-β-synthase gene to examine changes in retinal pathology following induction of diabetes. Their finding that elevated homocysteine levels hastens loss of cells in the retinal ganglion cell layer suggests that toxicity to ganglion cells may warrant further investigation as a potential mechanism of homocysteine enhanced susceptibility to diabetic retinopathy.

Drosophila arginine methyltransferase 1 (DART1) is an ecdysone receptor co-repressor

International Nuclear Information System (INIS)

Kimura, Shuhei; Sawatsubashi, Shun; Ito, Saya; Kouzmenko, Alexander; Suzuki, Eriko; Zhao, Yue; Yamagata, Kaoru; Tanabe, Masahiko; Ueda, Takashi; Fujiyama, Sari; Murata, Takuya; Matsukawa, Hiroyuki; Takeyama, Ken-ichi; Yaegashi, Nobuo

2008-01-01

Histone arginine methylation is an epigenetic marker that regulates gene expression by defining the chromatin state. Arginine methyltransferases, therefore, serve as transcriptional co-regulators. However, unlike other transcriptional co-regulators, the physiological roles of arginine methyltransferases are poorly understood. Drosophila arginine methyltransferase 1 (DART1), the mammalian PRMT1 homologue, methylates the arginine residue of histone H4 (H4R3me2). Disruption of DART1 in Drosophila by imprecise P-element excision resulted in low viability during metamorphosis in the pupal stages. In the pupal stage, an ecdysone hormone signal is critical for developmental progression. DART1 interacted with the nuclear ecdysone receptor (EcR) in a ligand-dependent manner, and co-repressed EcR in intact flies. These findings suggest that DART1, a histone arginine methyltransferase, is a co-repressor of EcR that is indispensable for normal pupal development in the intact fly

Decreased serum homocysteine levels after micronutrient supplementation in older people

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Pusparini Pusparini

2016-02-01

Full Text Available Aging is associated with a gradual impairment in cognitive function. The elderly also show a high prevalence of undernutrition, whereas nutrition plays an important role in the metabolism of neuronal cells and enzymes. Homocysteine is an amino acid resulting from methionine metabolism and is dependent on intake of vitamin B12, vitamin B6 and folic acid. Homocysteine is said to play a role in cognitive function. The objective of this study was to evaluate the effect of micronutrient supplementation for 6 months on serum homocysteine levels and cognitive function in older people. This study was an experimental study of pre-post test design, carried out in Mampang subdistrict, South Jakarta. A total of 94 elderly people was recruited for this study, consisting of 44 females and 50 males. Serum homocysteine level was assessed by fluorescent polarization immunoassay and cognitive function by means of the mini mental state examination (MMSE before and after micronutrient supplementation. Mean serum homocysteine concentration after supplementation decreased significantly to 14.8 ± 5.8 mmol/L, compared with mean serum homocysteine level of 15.9 ± 5.9 mmol/L before supplementation (p=0.000. Multiple regression analysis indicated that the factors influencing post-supplementation MMSE scores were gender (â=-0.350; p=0.000, education (â=0.510; p=0.000 and post-supplementation homocysteine levels (â=-0.201; p=0.000, while age, pre-supplementation homocysteine levels and BMI did not affect MMSE scores. Homocysteine concentration decreased significantly after 6 months of supplementation. The factors affecting post-supplementation MMSE scores were gender, level of education, and post-supplementation homocysteine level.

Decreased serum homocysteine levels after micronutrient supplementation in older people

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Pusparini

2010-12-01

Full Text Available Aging is associated with a gradual impairment in cognitive function. The elderly also show a high prevalence of undernutrition, whereas nutrition plays an important role in the metabolism of neuronal cells and enzymes. Homocysteine is an amino acid resulting from methionine metabolism and is dependent on intake of vitamin B12, vitamin B6 and folic acid. Homocysteine is said to play a role in cognitive function. The objective of this study was to evaluate the effect of micronutrient supplementation for 6 months on serum homocysteine levels and cognitive function in older people. This study was an experimental study of pre-post test design, carried out in Mampang subdistrict, South Jakarta. A total of 94 elderly people was recruited for this study, consisting of 44 females and 50 males. Serum homocysteine level was assessed by fluorescent polarization immunoassay and cognitive function by means of the mini mental state examination (MMSE before and after micronutrient supplementation. Mean serum homocysteine concentration after supplementation decreased significantly to 14.8 ± 5.8 mmol/L, compared with mean serum homocysteine level of 15.9 ± 5.9 mmol/L before supplementation (p=0.000. Multiple regression analysis indicated that the factors influencing post-supplementation MMSE scores were gender (â=-0.350; p=0.000, education (â=0.510; p=0.000 and post-supplementation homocysteine levels (â=-0.201; p=0.000, while age, pre-supplementation homocysteine levels and BMI did not affect MMSE scores. Homocysteine concentration decreased significantly after 6 months of supplementation. The factors affecting post-supplementation MMSE scores were gender, level of education, and post-supplementation homocysteine level.

Gbu Glycine Betaine Porter and Carnitine Uptake in Osmotically Stressed Listeria monocytogenes Cells

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Mendum, Mary Lou; Smith, Linda Tombras

2002-01-01

The food-borne pathogen Listeria monocytogenes grows actively under high-salt conditions by accumulating compatible solutes such as glycine betaine and carnitine from the medium. We report here that the dominant transport system for glycine betaine uptake, the Gbu porter, may act as a secondary uptake system for carnitine, with a Km of 4 mM for carnitine uptake and measurable uptake at carnitine concentrations as low as 10 μM. This porter has a Km for glycine betaine uptake of about 6 μM. The dedicated carnitine porter, OpuC, has a Km for carnitine uptake of 1 to 3 μM and a Vmax of approximately 15 nmol/min/mg of protein. Mutants lacking either opuC or gbu were used to study the effects of four carnitine analogs on growth and uptake of osmolytes. In strain DP-L1044, which had OpuC and the two glycine betaine porters Gbu and BetL, triethylglycine was most effective in inhibiting growth in the presence of glycine betaine, but trigonelline was best at inhibiting growth in the presence of carnitine. Carnitine uptake through OpuC was inhibited by γ-butyrobetaine. Dimethylglycine inhibited both glycine betaine and carnitine uptake through the Gbu porter. Carnitine uptake through the Gbu porter was inhibited by triethylglycine. Glycine betaine uptake through the BetL porter was strongly inhibited by trigonelline and triethylglycine. These results suggest that it is possible to reduce the growth of L. monocytogenes under osmotically stressful conditions by inhibiting glycine betaine and carnitine uptake but that to do so, multiple uptake systems must be affected. PMID:12406761

Induction of epigenetic variation in Arabidopsis by over-expression of DNA METHYLTRANSFERASE1 (MET1.

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Samuel Brocklehurst

Full Text Available Epigenetic marks such as DNA methylation and histone modification can vary among plant accessions creating epi-alleles with different levels of expression competence. Mutations in epigenetic pathway functions are powerful tools to induce epigenetic variation. As an alternative approach, we investigated the potential of over-expressing an epigenetic function, using DNA METHYLTRANSFERASE1 (MET1 for proof-of-concept. In Arabidopsis thaliana, MET1 controls maintenance of cytosine methylation at symmetrical CG positions. At some loci, which contain dense DNA methylation in CG- and non-CG context, loss of MET1 causes joint loss of all cytosines methylation marks. We find that over-expression of both catalytically active and inactive versions of MET1 stochastically generates new epi-alleles at loci encoding transposable elements, non-coding RNAs and proteins, which results for most loci in an increase in expression. Individual transformants share some common phenotypes and genes with altered gene expression. Altered expression states can be transmitted to the next generation, which does not require the continuous presence of the MET1 transgene. Long-term stability and epigenetic features differ for individual loci. Our data show that over-expression of MET1, and potentially of other genes encoding epigenetic factors, offers an alternative strategy to identify epigenetic target genes and to create novel epi-alleles.

Multiple-Site Trimethylation of Ribosomal Protein L11 by the PrmA Methyltransferase

Energy Technology Data Exchange (ETDEWEB)

Demirci,H.; Gregory, S.; Dahlberg, A.; Jogl, G.

2008-01-01

Ribosomal protein L11 is a universally conserved component of the large subunit, and plays a significant role during initiation, elongation, and termination of protein synthesis. In Escherichia coli, the lysine methyltransferase PrmA trimethylates the N-terminal a-amino group and the -amino groups of Lys3 and Lys39. Here, we report four PrmA-L11 complex structures in different orientations with respect to the PrmA active site. Two structures capture the L11 N-terminal a-amino group in the active site in a trimethylated postcatalytic state and in a dimethylated state with bound S-adenosyl-L-homocysteine. Two other structures show L11 in a catalytic orientation to modify Lys39 and in a noncatalytic orientation. The comparison of complex structures in different orientations with a minimal substrate recognition complex shows that the binding mode remains conserved in all L11 orientations, and that substrate orientation is brought about by the unusual interdomain flexibility of PrmA.

Histone methyltransferases in cancer

DEFF Research Database (Denmark)

Albert, Mareike; Helin, Kristian

2009-01-01

Cancer is perceived as a heterogeneous group of diseases that is characterized by aberrant patterns of gene expression. In the last decade, an increasing amount of data has pointed to a key role for epigenetic alterations in human cancer. In this review, we focus on a subclass of epigenetic...... regulators, namely histone methyltransferases (HMTs). Several HMTs have been linked to different types of cancer; however, in most cases we only have limited knowledge regarding the molecular mechanisms by which the HMTs contribute to disease development. We summarize the current knowledge regarding some...

Mutations in Cytosine-5 tRNA Methyltransferases Impact Mobile Element Expression and Genome Stability at Specific DNA Repeats

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Bianca Genenncher

2018-02-01

Full Text Available The maintenance of eukaryotic genome stability is ensured by the interplay of transcriptional as well as post-transcriptional mechanisms that control recombination of repeat regions and the expression and mobility of transposable elements. We report here that mutations in two (cytosine-5 RNA methyltransferases, Dnmt2 and NSun2, impact the accumulation of mobile element-derived sequences and DNA repeat integrity in Drosophila. Loss of Dnmt2 function caused moderate effects under standard conditions, while heat shock exacerbated these effects. In contrast, NSun2 function affected mobile element expression and genome integrity in a heat shock-independent fashion. Reduced tRNA stability in both RCMT mutants indicated that tRNA-dependent processes affected mobile element expression and DNA repeat stability. Importantly, further experiments indicated that complex formation with RNA could also contribute to the impact of RCMT function on gene expression control. These results thus uncover a link between tRNA modification enzymes, the expression of repeat DNA, and genomic integrity.

Crystallization of mouse S-adenosyl-l-homocysteine hydrolase

International Nuclear Information System (INIS)

Ishihara, Masaaki; Kusakabe, Yoshio; Ohsumichi, Tsuyoshi; Tanaka, Nobutada; Nakanishi, Masayuki; Kitade, Yukio; Nakamura, Kazuo T.

2010-01-01

Mouse S-adenosyl-l-homocysteine hydrolase has been crystallized in the presence of the reaction product adenosine. Diffraction data to 1.55 Å resolution were collected using synchrotron radiation. S-Adenosyl-l-homocysteine hydrolase (SAHH; EC 3.3.1.1) catalyzes the reversible hydrolysis of S-adenosyl-l-homocysteine to adenosine and l-homocysteine. For crystallographic investigations, mouse SAHH (MmSAHH) was overexpressed in bacterial cells and crystallized using the hanging-drop vapour-diffusion method in the presence of the reaction product adenosine. X-ray diffraction data to 1.55 Å resolution were collected from an orthorhombic crystal form belonging to space group I222 with unit-cell parameters a = 100.64, b = 104.44, c = 177.31 Å. Structural analysis by molecular replacement is in progress

Serum homocysteine levels in cerebrovascular accidents.

Science.gov (United States)

Zongte, Zolianthanga; Shaini, L; Debbarma, Asis; Singh, Th Bhimo; Devi, S Bilasini; Singh, W Gyaneshwar

2008-04-01

Hyperhomocysteinemia has been considered an independent risk factor in the development of stroke. The present study was undertaken to evaluate serum homocysteine levels in patients with cerebrovascular accidents among the Manipuri population and to compare with the normal cases. Ninety-three cerebrovascular accident cases admitted in the hospital were enrolled for the study and twenty-seven age and sex matched individuals free from cerebrovascular diseases were taken as control group. Serum homocysteine levels were estimated by ELISA method using Axis homocysteine EIA kit manufactured by Ranbaxy Diagnostic Ltd. India. The finding suggests that hyperhomocysteinemia is associated with cerebrovascular accident with male preponderance, which increases with advancing age. However, whether hyperhomocysteinemia is the cause or the result of cerebrovascular accidents needs further investigations.

Determination of Betaine in Lycium Barbarum L. by High Performance Capillary Electrophoresis

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Liu, Haixing; Wang, Chunyan; Peng, Xuewei

2017-12-01

This paper presents the determination of betaine content in Lycium barbarum L. by high performance capillary electrophoresis (HPCE) method. The borax solution was chosen as buffer solution, and its concentration was 40 mmol at a constant voltage of 20kV and injecting pressure time of 10s at 20°C. Linearity was kept in the concent ration range of 0.0113∼1.45mg of betaine with correlation coefficient of 0.9. The recovery was in the range of 97.95%∼126% (n=4). The sample content of betaine was 29.3mg/g and RSD 6.4% (n=6). This method is specific, simple and rapid and accurate, which is suitable for the detection of the content of betaine in Lycium barbarum L.

Isolation of glycine betaine and proline betaine from human urine. Assessment of their role as osmoprotective agents for bacteria and the kidney.

OpenAIRE

Chambers, S T; Kunin, C M

1987-01-01

Human urine is osmoprotective for enteric bacteria, permitting E. coli to grow with high concentrations of NaCl and other salts and even higher concentrations of sucrose and mannitol but not urea. The active material in urine is soluble in methanol and is precipitated by ammonium reineckate at acid pH. Using gel filtration and high-pressure liquid chromatography, we have identified two major osmoprotective compounds in urine. One is glycine betaine; the other is proline betaine as demonstrate...

The histone H3 lysine 9 methyltransferase DIM-5 modifies chromatin at frequency and represses light-activated gene expression.

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Ruesch, Catherine E; Ramakrishnan, Mukund; Park, Jinhee; Li, Na; Chong, Hin S; Zaman, Riasat; Joska, Tammy M; Belden, William J

2014-11-25

The transcriptional program controlling the circadian rhythm requires coordinated regulation of chromatin. Characterization of the chromodomain helicase DNA-binding enzyme CHD1 revealed DNA methylation in the promoter of the central clock gene frequency (frq) in Neurospora crassa. In this report, we show that the DNA methylation at frq is not only dependent on the DNA methyltransferase DIM-2 but also on the H3K9 methyltransferase DIM-5 and HP1. Histone H3 lysine 9 trimethylation (H3K9me3) occurs at frq and is most prominent 30 min after light-activated expression. Strains lacking dim-5 have an increase in light-induced transcription, and more White Collar-2 is found associated with the frq promoter. Consistent with the notion that DNA methylation assists in establishing the proper circadian phase, loss of H3K9 methylation results in a phase advance suggesting it delays the onset of frq expression. The dim-5 deletion strain displays an increase in circadian-regulated conidia formation on race tubes and there is a synthetic genetic interaction between dim-5 and ras-1(bd). These results indicate DIM-5 has a regulatory role in muting circadian output. Overall, the data support a model where facultative heterochromatic at frq serves to establish the appropriate phase, mute the light response, and repress circadian output. Copyright © 2015 Ruesch et al.

Homocysteine and Cognitive Performance in Elders with Self-Neglect

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Burnett, J.; Smith, S.M.; Aung, K.; Dyer, C.

2009-01-01

Elevated plasma homocysteine has been associated with altered cognitive performance in older adults. Elders referred to Adult Protective Services (APS) for self-neglect have been reported to have elevated plasma homocysteine levels and to suffer from cognitive impairment. This study assesses the association, if any, between plasma homocysteine and cognitive performance among elders with self-neglect. Methods: Sixty-five community-living adults, 65 years of age and older, reported to Adult Protective Services for self-neglect and 55 matched controls (matched for age, ethnicity, gender and socio-economic status) consented and participated in this study. The research team conducted in-home comprehensive geriatric assessments which included the mini-mental state exam (MMSE), the 15-item geriatric depression scale (GDS), the Wolf-Klein Clock Drawing Tests (CDT) and a comprehensive nutritional biochemistry panel, which included plasma homocysteine. Student s t tests and Pearson correlations were conducted to assess for bivariate associations. Results: Elders with self-neglect had significantly higher plasma homocysteine levels (M=12.68umol/L, sd=4.4) compared to the controls (M=10.40umol/L, sd=3.61;t=3.21, df=127, p=.002). There were no statistically significant associations between cognitive performance and plasma homocysteine in the self-neglect group, however there was a significant correlation between plasma homocysteine and the CDT among the controls (r=-.296, p=.022). Conclusion: Mean plasma homocysteine levels were significantly higher in elders with self-neglect, however, they do not appear to be related to cognitive performance, indicating that cognitive impairment in elder self-neglect involve mechanisms other than hyperhomocysteinemia. These findings warrant further investigation

Structural Basis of Substrate Recognition in Human Nicotinamide N-Methyltransferase

Energy Technology Data Exchange (ETDEWEB)

Peng, Yi; Sartini, Davide; Pozzi, Valentina; Wilk, Dennis; Emanuelli, Monica; Yee, Vivien C. (Case Western); (Politecnica Valencia)

2012-05-02

Nicotinamide N-methyltransferase (NNMT) catalyzes the N-methylation of nicotinamide, pyridines, and other analogues using S-adenosyl-L-methionine as donor. NNMT plays a significant role in the regulation of metabolic pathways and is expressed at markedly high levels in several kinds of cancers, presenting it as a potential molecular target for cancer therapy. We have determined the crystal structure of human NNMT as a ternary complex bound to both the demethylated donor S-adenosyl-L-homocysteine and the acceptor substrate nicotinamide, to 2.7 {angstrom} resolution. These studies reveal the structural basis for nicotinamide binding and highlight several residues in the active site which may play roles in nicotinamide recognition and NNMT catalysis. The functional importance of these residues was probed by mutagenesis. Of three residues near the nicotinamide's amide group, substitution of S201 and S213 had no effect on enzyme activity while replacement of D197 dramatically decreased activity. Substitutions of Y20, whose side chain hydroxyl interacts with both the nicotinamide aromatic ring and AdoHcy carboxylate, also compromised activity. Enzyme kinetics analysis revealed k{sub cat}/K{sub m} decreases of 2-3 orders of magnitude for the D197A and Y20A mutants, confirming the functional importance of these active site residues. The mutants exhibited substantially increased K{sub m} for both NCA and AdoMet and modestly decreased k{sub cat}. MD simulations revealed long-range conformational effects which provide an explanation for the large increase in K{sub m}(AdoMet) for the D197A mutant, which interacts directly only with nicotinamide in the ternary complex crystal structure.

Homocysteine and coronary heart disease

DEFF Research Database (Denmark)

Clarke, Robert; Bennett, Derrick A; Parish, Sarah

2012-01-01

Moderately elevated blood levels of homocysteine are weakly correlated with coronary heart disease (CHD) risk, but causality remains uncertain. When folate levels are low, the TT genotype of the common C677T polymorphism (rs1801133) of the methylene tetrahydrofolate reductase gene (MTHFR) appreci......Moderately elevated blood levels of homocysteine are weakly correlated with coronary heart disease (CHD) risk, but causality remains uncertain. When folate levels are low, the TT genotype of the common C677T polymorphism (rs1801133) of the methylene tetrahydrofolate reductase gene (MTHFR...

Effect of lipid-lowering and anti-hypertensive drugs on plasma homocysteine levels

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Jutta Dierkes

2007-03-01

Full Text Available Jutta Dierkes, Claus Luley, Sabine WestphalInstitute of Clinical Chemistry and Biochemistry, University Hospital Magdeburg, Germany Abstract: Elevated plasma concentrations of homocysteine, a sulfur-containing amino acid, are a risk factor for coronary, cerebral and peripheral artery disease. Next to other factors, drugs used for the prevention or treatment of cardiovascular disease may modulate plasma homocysteine levels. Thus, a drug induced homocysteine increase may counteract the desired cardioprotective effect. The aim is to summarize the current knowledge on the effect of two important classes of drugs, lipid-lowering drugs and anti-hypertensive drugs, on homocysteine metabolism. Among the lipid-lowering drugs, especially the fibric acid derivatives, which are used for treatment of hypertriglyceridemia and low HDL-cholesterol, are associated with an increase of homocysteine by 20%–50%. This increase can be reduced, but not totally avoided by the addition of folic acid, vitamin B12 and B6 to fibrates. HMG-CoA reductase inhibitors (statins do not influence homocysteine concentrations substantially. The effects of nicotinic acid and n3-fatty acids on the homocysteine concentrations are less clear, more studies are necessary to clarify their influence on homocysteine. Antihypertensive drugs have also been studied with respect to homocysteine metabolism. A homocysteine increase has been shown after treatment with hydrochlorothiazide, a lowering was observed after treatment with ß-blockers, but no effect with ACE-inhibitors. The clinical significance of the homocysteine elevation by fibrates and thiazides is not clear. However, individual patients use these drugs for long time, indicating that even moderate increases may be important.Keywords: homocysteine, fibrates, diuretics, cardiovascular disease

Egg-specific expression of protein with DNA methyltransferase activity in the biocarcinogenic liver fluke Clonorchis sinensis.

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Kim, Seon-Hee; Cho, Hye-Jeong; Sohn, Woon-Mok; Ahn, Chun-Seob; Kong, Yoon; Yang, Hyun-Jong; Bae, Young-An

2015-08-01

Despite recent reports regarding the biology of cytosine methylation in Schistosoma mansoni, the impact of the regulatory machinery remains unclear in diverse platyhelminthes. This ambiguity is reinforced by discoveries of DNA methyltransferase 2 (DNMT2)-only organisms and the substrate specificity of DNMT2 preferential to RNA molecules. Here, we characterized a novel DNA methyltransferase, named CsDNMT2, in a liver fluke Clonorchis sinensis. The protein exhibited structural properties conserved in other members of the DNMT2 family. The native and recombinant CsDNMT2 exhibited considerable enzymatic activity on DNA. The spatiotemporal expression of CsDNMT2 mirrored that of 5-methylcytosine (5 mC), both of which were elevated in the C. sinensis eggs. However, CsDNMT2 and 5 mC were marginally detected in other histological regions of C. sinensis adults including ovaries and seminal receptacle. The methylation site seemed not related to genomic loci occupied by progenies of an active long-terminal-repeat retrotransposon. Taken together, our data strongly suggest that C. sinensis has preserved the functional DNA methylation machinery and that DNMT2 acts as a genuine alternative to DNMT1/DNMT3 to methylate DNA in the DNMT2-only organism. The epigenetic regulation would target functional genes primarily involved in the formation and/or maturation of eggs, rather than retrotransposons.

Geographic distribution of methyltransferases of Helicobacter pylori: evidence of human host population isolation and migration

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Vítor Jorge MB

2009-09-01

Full Text Available Abstract Background Helicobacter pylori colonizes the human stomach and is associated with gastritis, peptic ulcer, and gastric cancer. This ubiquitous association between H. pylori and humans is thought to be present since the origin of modern humans. The H. pylori genome encodes for an exceptional number of restriction and modifications (R-M systems. To evaluate if R-M systems are an adequate tool to determine the geographic distribution of H. pylori strains, we typed 221 strains from Africa, America, Asia, and Europe, and evaluated the expression of different 29 methyltransferases. Results Independence tests and logistic regression models revealed that ten R-M systems correlate with geographical localization. The distribution pattern of these methyltransferases may have been originated by co-divergence of regional H. pylori after its human host migrated out of Africa. The expression of specific methyltransferases in the H. pylori population may also reflect the genetic and cultural background of its human host. Methyltransferases common to all strains, M. HhaI and M. NaeI, are likely conserved in H. pylori, and may have been present in the bacteria genome since the human diaspora out of Africa. Conclusion This study indicates that some methyltransferases are useful geomarkers, which allow discrimination of bacterial populations, and that can be added to our tools to investigate human migrations.

A coupled photometric assay for characterization of S-adenosyl-l-homocysteine hydrolases in the physiological hydrolytic direction.

Science.gov (United States)

Kailing, Lyn L; Bertinetti, Daniela; Herberg, Friedrich W; Pavlidis, Ioannis V

2017-10-25

S-Adenosyl-l-homocysteine hydrolases (SAHases) are important metabolic enzymes and their dysregulation is associated with some severe diseases. In vivo they catalyze the hydrolysis of S-adenosyl-l-homocysteine (SAH), the by-product of methylation reactions in various organisms. SAH is a potent inhibitor of methyltransferases, thus its removal from the equilibrium is an important requirement for methylation reactions. SAH hydrolysis is also the first step in the cellular regeneration process of the methyl donor S-adenosyl-l-methionine (SAM). However, in vitro the equilibrium lies towards the synthetic direction. To enable characterization of SAHases in the physiologically relevant direction, we have developed a coupled photometric assay that shifts the equilibrium towards hydrolysis by removing the product adenosine, using a high affinity adenosine kinase (AK). This converts adenosine to AMP and thereby forms equimolar amounts of ADP, which is phosphorylated by a pyruvate kinase (PK), in turn releasing pyruvate. The readout of the assay is the consumption of NADH during the lactate dehydrogenase (LDH) catalyzed reduction of pyruvate to lactic acid. The applicability of the assay is showcased for the determination of the kinetic constants of an SAHase from Bradyrhizobium elkanii (K M,SAH 41±5μM, v max,SAH 25±1μM/min with 0.13mg/mL enzyme). This assay is a valuable tool for in vitro characterization of SAHases with biotechnological potential, and for monitoring SAHase activity in diagnostics. Copyright © 2017 Elsevier B.V. All rights reserved.

Domain V of 23S rRNA contains all the structural elements necessary for recognition by the ErmE methyltransferase

DEFF Research Database (Denmark)

Vester, B; Douthwaite, S

1994-01-01

investigated what structural elements in 23S rRNA are required for specific recognition by the ErmE methyltransferase. The ermE gene was cloned into R1 plasmid derivatives, providing a means of inducible expression in Escherichia coli. Expression of the methyltransferase in vivo confers resistance......, and the enzyme efficiently modifies 23S rRNA in vitro. Removal of most of the 23S rRNA structure, so that only domain V (nucleotides 2000 to 2624) remains, does not affect the efficiency of modification by the methyltransferase. In addition, modification still occurs after the rRNA tertiary structure has been...

Homocysteine interference in neurulation: a chick embryo model.

NARCIS (Netherlands)

Afman, L.A.; Blom, H.J.; Put, N.M.J. van der; Straaten, H.W.M. van

2003-01-01

BACKGROUND: Periconceptional folic acid supplementation reduces the occurrence and recurrence risk of neural tube defects (NTD). Mothers of children with NTD have elevated plasma homocysteine levels. Administering homocysteine to chick embryos is reported to cause 27% NTD. Therefore, elevated plasma

Crystal structure of di-( N-methylmorpholine betaine)- L(+)-tartrate

Science.gov (United States)

Dega-Szafran, Z.; Dutkiewicz, G.; Kosturkiewicz, Z.; Szafran, M.

2002-11-01

The crystal structure of di-( N-methylmorpholine betaine)- L(+)-tartrate has been determined by X-ray diffraction method. Crystals are orthorhombic, space group P2 12 12 1, a=9.580(1), b=12.208(1), c=18.677(1) Å, Z=4, R=0.037. The molecule of L(+)-tartaric acid appears in the extended form with the hydroxyl groups as well as carboxyl groups in anti positions. The molecule is involved in a number of the intra- and intermolecular hydrogen bonds. The COOH groups of the tartaric acid link two non-equivalent N-methylmorpholine betaine molecules by a short, intermolecular O-H⋯O bonds of the lengths 2.456(1) and 2.510(1) Å. The OH groups form two different bifurcated hydrogen bonds, the intramolecular with the CO oxygen atoms (2.641(2) and 2.638(2) Å) and the intermolecular (2.919(2) and 3.084(2) Å) with neighbouring tartaric acid molecules, and link complexes in the zigzag ribbon parallel to the x-axis. The morpholine rings of both betaine molecules are in chair conformation with methyl groups in an axial position and CH 2COO - substituents in an equatorial one. In the crystals and the PM3-optimized structures there is no symmetry, both in the tartrate and N-methylmorpholine betaine moieties. FTIR spectrum confirms the complex structure of the investigated molecule.

Serum homocyst(e)ine levels in women with preeclampsia.

Science.gov (United States)

Mayerhofer, K; Hefler, L; Zeisler, H; Tempfer, C; Bodner, K; Stöckler-Ipsiroglu, S; Mühl, A; Kaider, A; Schatten, C; Leodolter, S; Husslein, P; Kainz, C

2000-03-24

Endothelial dysfunction has been described as the final common pathophysiological pathway in the development of preeclampsia. Since it has been suggested that homocyst(e)ine damages endothelial cells, we measured serum homocyst(e)ine levels in women with preeclampsia and in healthy pregnant women in order to find a new prognostic parameter for women with preeclampsia. Forty-five women with preeclampsia and 45 healthy women with uncomplicated pregnancies, matched for age and parity, were entered into the study. Serum homocyst(e)ine levels were measured by gas chromatography-mass spectrometry analysis and correlated to clinical data. Logistic regression models were used to analyse the influence of serum homocyst(e)ine levels on the presence of preeclampsia versus healthy pregnant women and on the risk of premature termination of pregnancy due to preeclampsia. Median serum homocyst(e)ine levels in women with preeclampsia and healthy pregnant women were 14.2 (range 5.7-38.1) mumol/L and 15.1 (range 5.2-23.1) mumol/L, respectively (Mann-Whitney U-test, p = 0.8). In univariate logistic regression models, serum homocyst(e)ine levels had no significant influence on the odds of presenting with preeclampsia versus healthy pregnant women (univariate logistic regression model, p = 0.8) and on the odds of premature termination of pregnancy due to preeclampsia (univariate logistic regression model, p = 0.3). Serum homocyst(e)ine levels are not elevated in women with preeclampsia and are not associated with clinical outcome in women with preeclampsia.

Homocystein: A new biochemical marker in livestock sector

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Suleyman Kozat

2017-12-01

Full Text Available The livestock sector is making great contributions to the world economy. Many different diseases, such as cardiovascular diseases, kidney and mineral substance insufficiency, cause huge losses in yield and production in the livestock sector. Early diagnosis is essential to combat these diseases. Today, homocysteine levels are used as biochemical markers in the diagnosis of the functions and diseases of many different organs in human medicine. Homocysteine is an amino acid that occurs in the process of methionine metabolism and does not enter the primary structure of proteins. Homocysteine is a biochemical marker used in the assessment of cardiovascular and renal diseases as well as other organ functions. In this review, homocysteine determination methods and detailed information about which organ and system diseases can be used in livestock sector will be given. [J Adv Vet Anim Res 2017; 4(4.000: 319-332

Guanidinoacetate methyltransferase (GAMT) deficiency: late onset of movement disorder and preserved expressive language.

Science.gov (United States)

O'Rourke, Declan J; Ryan, Stephanie; Salomons, Gajja; Jakobs, Cornelis; Monavari, Ahmad; King, Mary D

2009-05-01

Guanidinoacetate methyltransferase (GAMT) deficiency is a disorder of creatine biosynthesis, characterized by early-onset learning disability and epilepsy in most affected children. Severe expressive language delay is a constant feature even in the mildest clinical phenotypes.We report the clinical, biochemical, imaging, and treatment data of two female siblings (18y and 13y) with an unusual phenotype of GAMT deficiency. The oldest sibling had subacute onset of a movement disorder at age 17 years, later than has been previously reported. The younger sibling had better language skills than previously described in this disorder. After treatment with creatine, arginine restriction and ornithine-supplemented diet, seizure severity and movement disorder were reduced but cognition did not improve. This report confirms that GAMT deficiency, a heterogeneous, potentially treatable disorder, detected by increased levels of guanidinoacetate in body fluids (e.g. plasma or urine) or by an abnormal creatine peak on magnetic resonance spectroscopy, should be considered in patients of any age with unexplained, apparently static learning disability and epilepsy.

Low diagnostic value of fasting and post-methionine load homocysteine tests. A study in Dutch subjects with homocysteine test indications

NARCIS (Netherlands)

Fokkema, M R; Dijck-Brouwer, D A J; van Doormaal, J J; Reijngoud, D J; Muskiet, F A J

BACKGROUND: Homocysteine is a cardiovascular disease risk factor. We investigated, both in subjects with past plasma total homocysteine (tHcy) test indications and healthy adults, the diagnostic value of a fasting (tHcy) (f-tHcy) and the added value of a post-methionine-load tHcy (postload-tHcy).

Differential gene expression in the liver of the African lungfish, Protopterus annectens, after 6 months of aestivation in air or 1 day of arousal from 6 months of aestivation.

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Kum C Hiong

Full Text Available The African lungfish, Protopterus annectens, can undergo aestivation during drought. Aestivation has three phases: induction, maintenance and arousal. The objective of this study was to examine the differential gene expression in the liver of P. annectens after 6 months (the maintenance phase of aestivation as compared with the freshwater control, or after 1 day of arousal from 6 months aestivation as compared with 6 months of aestivation using suppression subtractive hybridization. During the maintenance phase of aestivation, the mRNA expression of argininosuccinate synthetase 1 and carbamoyl phosphate synthetase III were up-regulated, indicating an increase in the ornithine-urea cycle capacity to detoxify ammonia to urea. There was also an increase in the expression of betaine homocysteine-S-transferase 1 which could reduce and prevent the accumulation of hepatic homocysteine. On the other hand, the down-regulation of superoxide dismutase 1 expression could signify a decrease in ROS production during the maintenance phase of aestivation. In addition, the maintenance phase was marked by decreases in expressions of genes related to blood coagulation, complement fixation and iron and copper metabolism, which could be strategies used to prevent thrombosis and to conserve energy. Unlike the maintenance phase of aestivation, there were increases in expressions of genes related to nitrogen, carbohydrate and lipid metabolism and fatty acid transport after 1 day of arousal from 6 months aestivation. There were also up-regulation in expressions of genes that were involved in the electron transport system and ATP synthesis, indicating a greater demand for metabolic energy during arousal. Overall, our results signify the importance of sustaining a low rate of waste production and conservation of energy store during the maintenance phase, and the dependence on internal energy store for repair and structural modification during the arousal phase, of

Effects of dietary supplementation with betaine on a nonalcoholic steatohepatitis (NASH) mouse model.

Science.gov (United States)

Kawakami, Sakura; Han, Kyu-Ho; Nakamura, Yumi; Shimada, Ken-ichiro; Kitano, Tomoko; Aritsuka, Tsutomu; Nagura, Taizo; Ohba, Kiyoshi; Nakamura, Kimihide; Fukushima, Michihiro

2012-01-01

The effects of betaine supplementation on non-alcoholic steatohepatitis (NASH) model mice were examined by measuring the accumulation of fat in the livers of NASH model mice compared to a control. Betaine from sugar beets was provided to the model mice as a dietary supplement. After 3 wk of dietary supplementation, there were no significant differences in body weight or liver weight between the groups. However, the liver to body weight ratio in the high-fat diet with betaine (HFB) group was significantly (pNASH model mice.

Synthesis of mesomeric betaine compounds with imidazolium-enolate structure

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Nina Gonsior

2012-03-01

Full Text Available The synthesis of a heterocyclic mesomeric betaine by quaternization reaction of 1-butylimidazole and tetrabromo-1,4-benzoquinone is presented. The structure was verified by means of X-ray single-crystal analysis, NMR and IR spectroscopy. Inclusion complexes of the heterocyclic mesomeric betaine with randomly methylated (1.8 β-cyclodextrin were investigated by UV–vis spectroscopy. Furthermore, the reaction conditions were applied to poly(vinylimidazole and 1,4-bis(1H-imidazol-1-ylbutane to obtain functionalized polymer networks and condensate polymers, respectively.

Protein-bound homocyst(e)ine. A possible risk factor for coronary artery disease.

Science.gov (United States)

Kang, S S; Wong, P W; Cook, H Y; Norusis, M; Messer, J V

1986-01-01

The development of atherosclerotic changes and thromboembolism are common features in homocystinurics. Hence, we postulate a positive correlation between the level of homocyst(e)ine in the blood and the occurrence of coronary artery disease. Homocysteine is found either as free homocystine, cysteine-homocysteine mixed disulfide, or protein-bound homocyst(e)ine. In nonhomocystinuric subjects, most homocysteine molecules are detectable in the protein-bound form. Thus, protein-bound homocyst(e)ine in stored plasma which reflected total plasma homocyst(e)ine was determined in 241 patients with coronary artery disease (173 males and 68 females). The mean +/- SD total plasma homocyst(e)ine was 5.41 +/- 1.62 nmol/ml in male patients, 4.37 +/- 1.09 nmol/ml in male controls, 5.66 +/- 1.93 nmol/ml in female patients, and 4.16 +/- 1.62 nmol/ml in female controls. The differences between the patients with coronary artery disease and the controls were statistically significant (P less than 0.0005). PMID:3700650

Association between homocyst(e)ine levels and risk of vascular events.

Science.gov (United States)

Kaplan, Eugene D

2003-03-01

Homocyst(e)ine is a novel risk factor in vascular disease. First observations of vascular lesions in children with high blood homocyst(e)ine levels due to severe inborn enzyme deficiencies led to the hypothesis that elevated blood homocyst(e)ine levels might be a risk factor for vascular disease. A substantial body of evidence on the role of the homocyst(e)ine in the development of coronary and carotid artery disease, myocardial infarction, stroke, deep vein thrombosis and other disorders has been accumulated over the last 30 years. Cross-sectional and case-control studies provide initial and the strongest support for the hypothesis, followed by results from the prospective cohorts. Infrequent cases of homozygous mutations of the key enzymes in the homocyst(e)ine metabolism chain are able to produce extreme homocyst(e)inemia and early vascular lesions. More frequently, heterozygous enzyme mutations and deficiencies of folate and vitamins B6 and B12 cause mild to moderate homocyst(e)inemia, which is still strongly associated with the increased risk of vascular events. Elevated homocyst(e)ine levels may be effectively managed with adequate folate, B12 and B6 intake in doses comparable to or above FDA recommendations. Whether correction of elevated homocyst(e)ine levels with vitamins is helpful in prevention and treatment of vascular events remains unknown and is under investigation in ongoing clinical trials (VISP, VITATOPS). No consensus on homocyst(e)ine management is available at the present time.

Main: 1U1H [RPSD[Archive

Lifescience Database Archive (English)

Full Text Available bidopsis Thaliana Molecule: 5-Methyltetrahydropteroyltriglutamate-- Homocysteine Methyltransferase; Chain: A...QKDEALFSANAAALASRRSSPRVTNEGVQKAAAALKGSDHRRATNVSARLDAQQKKLNLPILPTTTIGSFPQTVELRRVRREYKAKKVSEEDYVKAI...GPVTILNWSFVRNDQPRHETCYQIALAIKDEVEDLEKGGIGVIQIDEAALREGLPLRKSEHAFYLDWAVHSFRITNCGVQDSTQIHTHMCYSHFNDIIHSIIDMDADV

[Homocystein--an independent risk factor for cardiovascular and thrombotic diseases].

Science.gov (United States)

Fowler, B

2005-09-01

Over the last 20 years homocysteine has taken on increasing importance as an independent, potentially modifiable risk factor for various forms of vascular disease including peripheral and cerebral vascular disease, coronary heart disease and thrombosis. This association has been ascertained in many retrospective and prospective studies but the strength of risk is not yet firmly established although it is clearly dependent on several modifying factors such as other risk factors, nutrition and genetic polymorphisms. Generally it is estimated that hyperhomocysteinaemia is responsible for about 10% of all risks. Homocysteine is formed from the dietary amino acid methionine and plays a pivotal role in folate metabolism and methyl group transfer. Its concentrations in tissues and plasma are influenced by many genetic and environmental factors, especially vitamins such as folate, B12 and B6 as well as certain medications and even life style factors. Nowadays the measurement of plasma homocysteine is freely available although care has to be taken in sample handling and interpretation of results. Final proof that homocysteine is a causal agent and not just a marker for cardiovascular disease and that reduction of plasma homocysteine by vitamin treatment reduces risk of cardiovascular disease is still awaited. Therefore at the present time neither wide-scale screening for homocysteine levels nor general prophylaxis with high dose vitamins is justified. However most experts recommend homocysteine determination in individuals with existing or high risk for arterial or venous blood vessel disease and their relatives. Elevated homocysteine can be lowered in such cases with a combination of folic acid, vitamin B12 vitamin B6. The results of ongoing trials on the impact of such treatment on risk of vascular disease are awaited with great interest.

A Picrinine N-Methyltransferase Belongs to a New Family of γ-Tocopherol-Like Methyltransferases Found in Medicinal Plants That Make Biologically Active Monoterpenoid Indole Alkaloids1[OPEN

Science.gov (United States)

Levac, Dylan; Cázares, Paulo; Yu, Fang

2016-01-01

Members of the Apocynaceae plant family produce a large number of monoterpenoid indole alkaloids (MIAs) with different substitution patterns that are responsible for their various biological activities. A novel N-methyltransferase involved in the vindoline pathway in Catharanthus roseus showing distinct similarity to γ-tocopherol C-methyltransferases was used in a bioinformatic screen of transcriptomes from Vinca minor, Rauvolfia serpentina, and C. roseus to identify 10 γ-tocopherol-like N-methyltransferases from a large annotated transcriptome database of different MIA-producing plant species (www.phytometasyn.ca). The biochemical function of two members of this group cloned from V. minor (VmPiNMT) and R. serpentina (RsPiNMT) have been characterized by screening their biochemical activities against potential MIA substrates harvested from the leaf surfaces of MIA-accumulating plants. The approach was validated by identifying the MIA picrinine from leaf surfaces of Amsonia hubrichtii as a substrate of VmPiNMT and RsPiNMT. Recombinant proteins were shown to have high substrate specificity and affinity for picrinine, converting it to N-methylpicrinine (ervincine). Developmental studies with V. minor and R. serpentina showed that RsPiNMT and VmPiNMT gene expression and biochemical activities were highest in younger leaf tissues. The assembly of at least 150 known N-methylated MIAs within members of the Apocynaceae family may have occurred as a result of the evolution of the γ-tocopherol-like N-methyltransferase family from γ-tocopherol methyltransferases. PMID:26848097

Homocysteine as a potential biochemical marker for depression in elderly stroke survivors

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Michaela C. Pascoe

2012-04-01

Full Text Available Background: Elderly stroke survivors have been reported to be at risk of malnutrition and depression. Vitamin B-related metabolites such as methylmalonic acid and homocysteine have been implicated in depression. Objective: We conducted a study exploring the relationship between homocysteine and post-stroke depression. Design: Three methodologies were used: Observational cohort study of elderly Swedish patients (n=149 1.5 years post-stroke, assessed using Diagnostic and Statistical Manual of Mental Disorders, Montgomery Åsberg Depression Rating Scale and serum blood levels of methylmalonic acid and homocysteine. Results: Homocysteine significantly correlated with depressive symptomatology in stroke survivors (β = 0.18*. Individuals with abnormal levels of methylmalonic acid and homocysteine were almost twice more likely to show depressive symptomatology than those with normal levels (depressive symptoms 22%; no depressive symptoms 12%. Comparison of methylmalonic acid and homocysteine levels with literature data showed fewer stroke survivors had vitamin deficiency than did reference individuals (normal range 66%; elevated 34%. Conclusions: Homocysteine is significantly associated with depressive symptomatology in elderly Swedish stroke survivors.

Unfiltered coffee increases plasma homocysteine concentrations in healthy volunteers: a randomized trial

NARCIS (Netherlands)

Grubben, M. J.; Boers, G. H.; Blom, H. J.; Broekhuizen, R.; de Jong, R.; van Rijt, L.; de Ruijter, E.; Swinkels, D. W.; Nagengast, F. M.; Katan, M. B.

2000-01-01

An elevated plasma homocysteine concentration is a putative risk factor for cardiovascular disease. Observational studies have reported an association between coffee consumption and plasma homocysteine concentrations. We studied the effect of coffee consumption on plasma homocysteine in a crossover

Higher Dietary Choline and Betaine Intakes Are Associated with Better Body Composition in the Adult Population of Newfoundland, Canada.

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Xiang Gao

Full Text Available Choline is an essential nutrient and betaine is an osmolyte and methyl donor. Both are important to maintain health including adequate lipid metabolism. Supplementation of dietary choline and betaine increase muscle mass and reduce body fat in animals. However, little data is available regarding the role of dietary choline and betaine on body composition in humans.To investigate the association between dietary choline and betaine intakes with body composition in a large population based cross-sectional study.A total of 3214 subjects from the CODING (Complex Disease in Newfoundland population: Environment and Genetics study were assessed. Dietary choline and betaine intakes were computed from the Willett Food Frequency questionnaire. Body composition was measured using dual-energy X-ray absorptiometry following a 12-hour fast. Major confounding factors including age, sex, total calorie intake and physical activity level were controlled in all analyses.Significantly inverse correlations were found between dietary choline and betaine intakes, with all obesity measurements: total percent body fat (%BF, percent trunk fat (%TF, percent android fat (%AF, percent gynoid fat (%GF and anthropometrics: weight, body mass index, waist circumference, waist-to-hip ratio in both women and men (r range from -0.13 to -0.47 for choline and -0.09 to -0.26 for betaine, p<0.001 for all. Dietary choline intake had stronger association than betaine. Moreover, obese subjects had the lowest dietary choline and betaine intakes, with overweight subjects in the middle, and normal weight subjects consumed the highest dietary choline and betaine (p<0.001. Vice versa, when subjects were ranked according to dietary choline and betaine intakes, subjects with the highest intake of both had the lowest %TF, %AF, %GF, %BF and highest %LM among the groups in both sexes.Our findings indicate that high dietary choline and betaine intakes are significantly associated with favorable body

Cocamidopropyl betaine.

Science.gov (United States)

Jacob, Sharon E; Amini, Sadegh

2008-01-01

Cocamidopropyl betaine (CAPB) is an amphoteric synthetic detergent that has been increasingly used in cosmetics and personal hygiene products (eg, shampoos, contact lens solutions, toothpaste detergents, makeup removers, bath gels, skin care products, cleansers, liquid soaps, antiseptics, and gynecologic and anal hygiene products) because it induces relatively mild skin irritation. Delayed T-cell-mediated type IV hypersensitivity reactions to CAPB have been reported, and contact sensitization prevalence is estimated at between 3.0 and 7.2%. The increasing rates of sensitization led to CAPB's being named Allergen of the Year in 2004. Related impurities rendered during the manufacturing process (such as amidoamine and dimethylaminopropylamine) are thought to play a role in sensitization.

Effect of consumption of red wine, spirits and beer on serum homocysteine

NARCIS (Netherlands)

Gaag, M.S. van der; Ubbink, J.B.; Sillanaukee, P.; Nikkari, S.; Hendriks, H.F.J.

2000-01-01

Serum homocysteine increases after moderate consumption of red wine and spirits, but not after moderate consumption of beer. Vitamin B6 in beer seems to prevent the alcohol-induced rise in serum homocysteine. Chemicals/CAS: Homocysteine, 454-28-4; Pyridoxine, 65-23-6

The phenotypic and molecular assessment of the non-conserved Arabidopsis MICRORNA163/S-ADENOSYL-METHYLTRANSFERASE regulatory module during biotic stress.

Science.gov (United States)

Litholdo, Celso Gaspar; Eamens, Andrew Leigh; Waterhouse, Peter Michael

2018-04-01

In plants, microRNAs (miRNAs) have evolved in parallel to the protein-coding genes that they target for expression regulation, and miRNA-directed gene expression regulation is central to almost every cellular process. MicroRNA, miR163, is unique to the Arabidopsis genus and is processed into a 24-nucleotide (nt) mature small regulatory RNA (sRNA) from a single precursor transcript transcribed from a single locus, the MIR163 gene. The MIR163 locus is a result of a recent inverted duplication event of one of the five closely related S-ADENOSYL-METHYLTRANSFERASE genes that the mature miR163 sRNA targets for expression regulation. Currently, however, little is known about the role of the miR163/S-ADENOSYL-METHYLTRANSFERASE regulatory module in response to biotic stress. Here, we document the expression domains of MIR163 and the S-ADENOSYL-METHYLTRANSFERASE target genes following fusion of their putative promoter sequences to the β-glucuronidase (GUS) reporter gene and subsequent in planta expression. Further, we report on our phenotypic and molecular assessment of Arabidopsis thaliana plants with altered miR163 accumulation, namely the mir163-1 and mir163-2 insertion knockout mutants and the miR163 overexpression line, the MIR163-OE plant. Finally, we reveal miR163 accumulation and S-ADENOSYL-METHYLTRANSFERASE target gene expression post treatment with the defence elicitors, salicylic acid and jasmonic acid, and following Fusarium oxysporum infection, wounding, and herbivory attack. Together, the work presented here provides a comprehensive new biological insight into the role played by the Arabidopsis genus-specific miR163/S-ADENOSYL-METHYLTRANSFERASE regulatory module in normal A. thaliana development and during the exposure of A. thaliana plants to biotic stress.

Serum Homocysteine level in patients with Multiple Sclerosis

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F Ashtari

2005-09-01

Full Text Available Background: The etiology of multiple sclerosis (MS, a chronic demyelinative disease-is unknown. The damage of blood–brain barrier (BBB vasculature is a characteristic of MS and Homocystein (Hcy can damage BBB, then increase in total Hcy may be important in MS pathogenesis. The aim of this study was to compare the serum level of total Hcy in MS patients with control group. Methods: In a case control study, serum level of total Hcy measured in 35 MS patient and compared with 30 healthy matched controls. All patients had definitive MS according to Poser criteria, without history of myocardial infarction, stroke, neuropathy, transient ischemic attack, homocystinuria or renal failure. Results: The serum concentration of total homocystein was significantly higher in multiple sclerosis patients than healthy controls. The mean total Hcy level was 17.92± 6.9 mmol/lit in cases and 14.6±2.92 mmol/lit in controls (P=0.013. Conclusion: Serum total Homocystein may have a role in MS pathogenesis and reduction of it should be studied moreover. Key words: Multiple Sclerosis, Homocystein, Serum level

MicroRNA-29a Alleviates Bile Duct Ligation Exacerbation of Hepatic Fibrosis in Mice through Epigenetic Control of Methyltransferases

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Ya-Ling Yang

2017-01-01

Full Text Available MicroRNA-29 (miR-29 is found to modulate hepatic stellate cells’ (HSCs activation and, thereby, reduces liver fibrosis pathogenesis. Histone methyltransferase regulation of epigenetic reactions reportedly participates in hepatic fibrosis. This study is undertaken to investigate the miR-29a regulation of the methyltransferase signaling and epigenetic program in hepatic fibrosis progression. miR-29a transgenic mice (miR-29aTg mice and wild-type littermates were subjected to bile duct-ligation (BDL to develop cholestatic liver fibrosis. Primary HSCs were transfected with a miR-29a mimic and antisense inhibitor. Profibrogenic gene expression, histone methyltransferases and global genetic methylation were probed with real-time quantitative RT-PCR, immunohistochemical stain, Western blot and ELISA. Hepatic tissue in miR-29aTg mice displayed weak fibrotic matrix as evidenced by Sirius Red staining concomitant with low fibrotic matrix collagen 1α1 expression within affected tissues compared to the wild-type mice. miR-29a overexpression reduced the BDL exaggeration of methyltransferases, DNMT1, DNMT3b and SET domain containing 1A (SET1A expression. It also elevated phosphatase and tensin homolog deleted on chromosome 10 (PTEN signaling within liver tissue. In vitro, miR-29a mimic transfection lowered collagen 1α1, DNMT1, DNMT3b and SET1A expression in HSCs. Gain of miR-29a signaling resulted in DNA hypomethylation and high PTEN expression. This study shines a new light on miR-29a inhibition of methyltransferase, a protective effect to maintain the DNA hypomethylation state that decreases fibrogenic activities in HSC. These robust analyses also highlight the miR-29a regulation of epigenetic actions to ameliorate excessive fibrosis during cholestatic liver fibrosis development.

Variation of Polyphenols and Betaines in Aerial Parts of Young, Field-Grown Amaranthus Genotypes

DEFF Research Database (Denmark)

Steffensen, Stine Krogh; Pedersen, H. A.; Labouriau, R.

2011-01-01

-trans-feruloyltyramine, N-trans-feruloyl-4-O-methyldopamine), and betaines (glycinebetaine, trigonelline) were determined. The variation in phytochemical content due to species and cultivation site was analyzed utilizing the multivariate statistical methods of principal component analysis (PCA) and graphical model (GM...... primarily by a higher content of trigonelline and the two hydroxycinnamyl amides in A. mantegazzianus. The GM showed that the quantities of the different analytes within each compound group were intercorrelated except in the case of the betaines. The betaines carried no information on each other...

Functional characterization of KanP, a methyltransferase from the kanamycin biosynthetic gene cluster of Streptomyces kanamyceticus.

Science.gov (United States)

Nepal, Keshav Kumar; Yoo, Jin Cheol; Sohng, Jae Kyung

2010-09-20

KanP, a putative methyltransferase, is located in the kanamycin biosynthetic gene cluster of Streptomyces kanamyceticus ATCC12853. Amino acid sequence analysis of KanP revealed the presence of S-adenosyl-L-methionine binding motifs, which are present in other O-methyltransferases. The kanP gene was expressed in Escherichia coli BL21 (DE3) to generate the E. coli KANP recombinant strain. The conversion of external quercetin to methylated quercetin in the culture extract of E. coli KANP proved the function of kanP as S-adenosyl-L-methionine-dependent methyltransferase. This is the first report concerning the identification of an O-methyltransferase gene from the kanamycin gene cluster. The resistant activity assay and RT-PCR analysis demonstrated the leeway for obtaining methylated kanamycin derivatives from the wild-type strain of kanamycin producer. 2009 Elsevier GmbH. All rights reserved.

[Estimation of relation between homocysteine concentration and selected lipid parameters and adhesion molecules concentration in children with atherosclerosis risk factors].

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Sierakowska-Fijałek, Anna; Baj, Zbigniew; Kaczmarek, Piotr; Stepień, Mariusz; Rysz, Jacek

2008-10-01

Atherosclerosis begins in childhood. At present among numerous risk factors of atherosclerosis the role of hiperhomocysteinemia in development of cardiovascular heart disease is taken under consideration. Atherogenic effect of homocystein is related to its cytotoxin action, conducting to endothelial dysfunction and damage. It is correlated with increase of the lipid levels in the blood serum and change of expression of the soluble forms of adhesion molecules. The aim of this study was to estimate relations between the homocystein serum concentration, expression of the selected adhesion molecules and the lipid levels in the blood serum in children with atherosclerosis risk factors. The group consisted of 670 children, 76 of them had atherosclerosis risk factors. In further examination 48 children have taken a part, whose parents were agreed for theirs participation in the program. The comparative group composed of 25 children without the risk factors. We determined total cholesterol (TC), triglycerides (TG), LDL cholesterol fraction (LDL-C), HDL cholesterol fraction (HDL-C), serum homocysteine concentration (Hcy), the expression of the soluble forms of adhesion molecules (sCAM): sP-selectin and sVCAM-1 (vascular cell adhesion molecule-1). Obesity, hypertension and lipid disorders in the shape of higher concentration of TC, LDL-C, TG and lower HDL-C were the most frequent risk factors in the investigated children. No significant differences in serum homocysteine concentration were observed between the investigated groups. However, its concentration was significantly higher in children with two atherosclerosis risk factors. No significant differences in expression of s-VCAM-1 were observed in the investigated groups, concentration of sP-selectin was significantly higher in children with atherosclerosis risk factors (phomocysteine and chosen adhesion molecules in children with atherosclerosis risk factors might potentially constitute the marker of early

Methyltransferase That Modifies Guanine 966 of the 16 S rRNA: FUNCTIONAL IDENTIFICATION AND TERTIARY STRUCTURE*

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Lesnyak, Dmitry V.; Osipiuk, Jerzy; Skarina, Tatiana; Sergiev, Petr V.; Bogdanov, Alexey A.; Edwards, Aled; Savchenko, Alexei; Joachimiak, Andrzej; Dontsova, Olga A.

2010-01-01

N2-Methylguanine 966 is located in the loop of Escherichia coli 16 S rRNA helix 31, forming a part of the P-site tRNA-binding pocket. We found yhhF to be a gene encoding for m2G966 specific 16 S rRNA methyltransferase. Disruption of the yhhF gene by kanamycin resistance marker leads to a loss of modification at G966. The modification could be rescued by expression of recombinant protein from the plasmid carrying the yhhF gene. Moreover, purified m2G966 methyltransferase, in the presence of S-adenosylomethionine (AdoMet), is able to methylate 30 S ribosomal subunits that were purified from yhhF knock-out strain in vitro. The methylation is specific for G966 base of the 16 S rRNA. The m2G966 methyltransferase was crystallized, and its structure has been determined and refined to 2.05 Å. The structure closely resembles RsmC rRNA methyltransferase, specific for m2G1207 of the 16 S rRNA. Structural comparisons and analysis of the enzyme active site suggest modes for binding AdoMet and rRNA to m2G966 methyltransferase. Based on the experimental data and current nomenclature the protein expressed from the yhhF gene was renamed to RsmD. A model for interaction of RsmD with ribosome has been proposed. PMID:17189261

Methyltransferase that modifies guanine 966 of the 16 S rRNA: functional identification and tertiary structure.

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Lesnyak, Dmitry V; Osipiuk, Jerzy; Skarina, Tatiana; Sergiev, Petr V; Bogdanov, Alexey A; Edwards, Aled; Savchenko, Alexei; Joachimiak, Andrzej; Dontsova, Olga A

2007-02-23

N(2)-Methylguanine 966 is located in the loop of Escherichia coli 16 S rRNA helix 31, forming a part of the P-site tRNA-binding pocket. We found yhhF to be a gene encoding for m(2)G966 specific 16 S rRNA methyltransferase. Disruption of the yhhF gene by kanamycin resistance marker leads to a loss of modification at G966. The modification could be rescued by expression of recombinant protein from the plasmid carrying the yhhF gene. Moreover, purified m(2)G966 methyltransferase, in the presence of S-adenosylomethionine (AdoMet), is able to methylate 30 S ribosomal subunits that were purified from yhhF knock-out strain in vitro. The methylation is specific for G966 base of the 16 S rRNA. The m(2)G966 methyltransferase was crystallized, and its structure has been determined and refined to 2.05A(.) The structure closely resembles RsmC rRNA methyltransferase, specific for m(2)G1207 of the 16 S rRNA. Structural comparisons and analysis of the enzyme active site suggest modes for binding AdoMet and rRNA to m(2)G966 methyltransferase. Based on the experimental data and current nomenclature the protein expressed from the yhhF gene was renamed to RsmD. A model for interaction of RsmD with ribosome has been proposed.

Glycine Betaine and Proline Production in Eucalyptus Plant under NaCl Harassing Environment

International Nuclear Information System (INIS)

Qureshi, T. M.; Bano, A.; Ashraf, M. Y.

2015-01-01

An investigation has been carried out to study the production of Proline and Betaine by applying Abscisic acid (ABA) treatment under NaCl and water stressed conditions. The seeds of four provenances of Eucalyptus camaldulesnis were obtained from the University of Agriculture, Faisalabad (Provenance I), Punjab Forest Research Institute, Faisalabad (Provenance II), Bio-saline Research Station-I, Lahore (Provenance III) and Bio-saline Research Station-II of Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad (Provenance 1V). It was observed that Proline and Betaine accumulation increased significantly in all the provenances with increase in drought or salt stress, ABA alone and in combination with drought. Provenance II and III species remained successful in maintaining higher Proline and Betaine accumulation as compared to Provenances I and IV. From the results it can be concluded that ABA treatment remains successful in enhancing Proline and Betaine production and maintaining the physiological parameters necessary to enhance plant growth both under salt and in combination with drought condition. (author)

Purification, crystallization and preliminary crystallographic studies of plant S-adenosyl-l-homocysteine hydrolase (Lupinus luteus)

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Brzezinski, Krzysztof [Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan (Poland); Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan (Poland); Bujacz, Grzegorz [Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan (Poland); Faculty of Food Chemistry and Biotechnology, Technical University of Lodz (Poland); Jaskolski, Mariusz, E-mail: mariuszj@amu.edu.pl [Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan (Poland); Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan (Poland)

2008-07-01

Single crystals of recombinant S-adenosyl-l-homocysteine hydrolase from L. luteus in complex with adenosine diffract X-rays to 1.17 Å resolution at 100 K. The crystals are tetragonal, space group P4{sub 3}2{sub 1}2, and contain one copy of the dimeric enzyme in the asymmetric unit. By degrading S-adenosyl-l-homocysteine, which is a byproduct of S-adenosyl-l-methionine-dependent methylation reactions, S-adenosyl-l-homocysteine hydrolase (SAHase) acts as a regulator of cellular methylation processes. S-Adenosyl-l-homocysteine hydrolase from the leguminose plant yellow lupin (Lupinus luteus), LlSAHase, which is composed of 485 amino acids and has a molecular weight of 55 kDa, has been cloned, expressed in Escherichia coli and purified. Crystals of LlSAHase in complex with adenosine were obtained by the hanging-drop vapour-diffusion method using 20%(w/v) PEG 4000 and 10%(v/v) 2-propanol as precipitants in 0.1 M Tris–HCl buffer pH 8.0. The crystals were tetragonal, space group P4{sub 3}2{sub 1}2, with unit-cell parameters a = 122.4, c = 126.5 Å and contained two protein molecules in the asymmetric unit, corresponding to the functional dimeric form of the enzyme. Atomic resolution (1.17 Å) X-ray diffraction data have been collected using synchrotron radiation.

Purification, crystallization and preliminary crystallographic studies of plant S-adenosyl-l-homocysteine hydrolase (Lupinus luteus)

International Nuclear Information System (INIS)

Brzezinski, Krzysztof; Bujacz, Grzegorz; Jaskolski, Mariusz

2008-01-01

Single crystals of recombinant S-adenosyl-l-homocysteine hydrolase from L. luteus in complex with adenosine diffract X-rays to 1.17 Å resolution at 100 K. The crystals are tetragonal, space group P4 3 2 1 2, and contain one copy of the dimeric enzyme in the asymmetric unit. By degrading S-adenosyl-l-homocysteine, which is a byproduct of S-adenosyl-l-methionine-dependent methylation reactions, S-adenosyl-l-homocysteine hydrolase (SAHase) acts as a regulator of cellular methylation processes. S-Adenosyl-l-homocysteine hydrolase from the leguminose plant yellow lupin (Lupinus luteus), LlSAHase, which is composed of 485 amino acids and has a molecular weight of 55 kDa, has been cloned, expressed in Escherichia coli and purified. Crystals of LlSAHase in complex with adenosine were obtained by the hanging-drop vapour-diffusion method using 20%(w/v) PEG 4000 and 10%(v/v) 2-propanol as precipitants in 0.1 M Tris–HCl buffer pH 8.0. The crystals were tetragonal, space group P4 3 2 1 2, with unit-cell parameters a = 122.4, c = 126.5 Å and contained two protein molecules in the asymmetric unit, corresponding to the functional dimeric form of the enzyme. Atomic resolution (1.17 Å) X-ray diffraction data have been collected using synchrotron radiation

Homocystein as a risk factor for developing complications in chronic renal failure.

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Jakovljevic, Biljana; Gasic, Branislav; Kovacevic, Pedja; Rajkovaca, Zvezdana; Kovacevic, Tijana

2015-04-01

Cardiovascular diseases are leading cause of death in patients with chronic renal failure. The aim of our study was to establish connection between levels of homocysteine and traditional and nontraditional risk factors for developing cardiovascular diseases in dialysis and pre dialysis patients. We included 33 pre dialysis (23 in stage three and 10 in stage four of chronic kidney disease) and 43 patients receiving hemodialysis longer than six months. Besides standard laboratory parameters, levels of homocysteine and blood pressure were measured in all patients. Glomerular filtration rate was measured in pre dialysis patients and dialysis quality parameters in dialysis patients. Homocysteine levels were elevated in all patients (19±5.42mmol/l). The connection between homocysteine levels and other cardiovascular diseases risk factors was not established in pre dialysis patients. In patients treated with hemodialysis we found negative correlation between homocysteine levels and patients' age (phomocysteine levels and length of dialysis (phomocysteine and anemia parameters (erythrocytes, hemoglobin), (pHomocysteine and LDL (and total cholesterol) were in negative correlation (pHomocysteine, as one of nontraditional cardiovascular diseases risk factors, is elevated in all patients with chronic renal failure and it's positive correlation with some other risk factors was found.

Apoptosis of bone marrow mesenchymal stem cells caused by homocysteine via activating JNK signal.

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Benzhi Cai

Full Text Available Bone marrow mesenchymal stem cells (BMSCs are capable of homing to and repair damaged myocardial tissues. Apoptosis of BMSCs in response to various pathological stimuli leads to the attenuation of healing ability of BMSCs. Plenty of evidence has shown that elevated homocysteine level is a novel independent risk factor of cardiovascular diseases. The present study was aimed to investigate whether homocysteine may induce apoptosis of BMSCs and its underlying mechanisms. Here we uncovered that homocysteine significantly inhibited the cellular viability of BMSCs. Furthermore, TUNEL, AO/EB, Hoechst 333342 and Live/Death staining demonstrated the apoptotic morphological appearance of BMSCs after homocysteine treatment. A distinct increase of ROS level was also observed in homocysteine-treated BMSCs. The blockage of ROS by DMTU and NAC prevented the apoptosis of BMSCs induced by homocysteine, indicating ROS was involved in the apoptosis of BMSCs. Moreover, homocysteine also caused the depolarization of mitochondrial membrane potential of BMSCs. Furthermore, apoptotic appearance and mitochondrial membrane potential depolarization in homocysteine-treated BMSCs was significantly reversed by JNK inhibitor but not p38 MAPK and ERK inhibitors. Western blot also confirmed that p-JNK was significantly activated after exposing BMSCs to homocysteine. Homocysteine treatment caused a significant reduction of BMSCs-secreted VEGF and IGF-1 in the culture medium. Collectively, elevated homocysteine induced the apoptosis of BMSCs via ROS-induced the activation of JNK signal, which provides more insight into the molecular mechanisms of hyperhomocysteinemia-related cardiovascular diseases.

Elevated second-trimester serum homocyst(e)ine levels and subsequent risk of preeclampsia.

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Sorensen, T K; Malinow, M R; Williams, M A; King, I B; Luthy, D A

1999-01-01

Elevated plasma homocyst(e)ine is a risk factor for endothelial dysfunction and vascular disease. In late gestation, levels of homocyst(e)ine are higher in preeclamptics, as compared with normotensive pregnant women. Our objective was to determine whether homocyst(e)ine elevations precede the development of preeclampsia. We used a prospective nested case-control study design to compare second trimester maternal serum homocyst(e)ine concentrations in 52 patients who developed preeclampsia (pregnancy-induced hypertension with proteinuria) compared with 56 women who remained normotensive throughout pregnancy. Study subjects were selected from a base population of 3, 042 women who provided blood samples at an average gestational age of 16 weeks and later delivered at our center. Serum homocyst(e)ine was measured by high-performance liquid chromatography and electrochemical detection. Approximately 29% of preeclamptics, as compared to 13% of controls had homocyst(e)ine levels >/=5.5 micromol/l (upper decile of distribution of control values). Adjusted for maternal age, parity, and body mass-index, a second trimester elevation of homocyst(e)ine was associated with a 3. 2-fold increased risk of preeclampsia (adjusted OR = 3.2; 95% CI 1. 1-9.2; p = 0.030). There was evidence of a interaction between maternal adiposity (as indicated by her prepregnancy body mass index) and parity with second trimester elevations in serum homocyst(e)ine. Nulliparous women with elevated homocyst(e)ine levels experienced a 9.7-fold increased risk of preeclampsia as compared with multiparous women without homocyst(e)ine elevations (95% CI 2.1-14.1; p = 0.003). Women with a higher prepregnancy body mass index (>/=21.4 kg/m(2), or upper 50th percentile) and who also had elevated homocyst(e)ine levels, as compared with leaner women without homocyst(e)ine elevations were 6.9 times more likely to later develop preeclampsia (95% CI 1.4-32.1; p = 0.016). Our findings are consistent with other

[Blue-light induced expression of S-adenosy-L-homocysteine hydrolase-like gene in Mucor amphibiorum RCS1].

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Gao, Ya; Wang, Shu; Fu, Mingjia; Zhong, Guolin

2013-09-04

To determine blue-light induced expression of S-adenosyl-L-homocysteine hydrolase-like (sahhl) gene in fungus Mucor amphibiorum RCS1. In the random process of PCR, a sequence of 555 bp was obtained from M. amphibiorum RCS1. The 555 bp sequence was labeled with digoxin to prepare the probe for northern hybridization. By northern hybridization, the transcription of sahhl gene was analyzed in M. amphibiorum RCS1 mycelia culture process from darkness to blue light to darkness. Simultaneously real-time PCR method was used to the sahhl gene expression analysis. Compared with the sequence of sahh gene from Homo sapiens, Mus musculus and some fungi species, a high homology of the 555 bp sequence was confirmed. Therefore, the preliminary confirmation has supported that the 555 bp sequence should be sahhl gene from M. amphibiorum RCS1. Under the dark pre-culture in 24 h, a large amounts of transcript of sahhl gene in the mycelia can be detected by northern hybridization and real-time PCR in the condition of 24 h blue light. But a large amounts of transcript of sahhl gene were not found in other detection for the dark pre-culture of 48 h, even though M. amphibiorum RCS1 mycelia were induced by blue light. Blue light can induce the expression of sahhl gene in the vigorous growth of M. amphibiorum RCS1 mycelia.

Patients with atherosclerotic vascular disease: how low should plasma homocyst(e)ine levels go?

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Spence, J D

2001-01-01

Plasma homocyst(e)ine level is a strong independent risk factor for vascular disease. The spelling of homocyst(e)ine reflects that what is measured, and what constitutes the risk factor; it includes homocysteine, homocystine (the dimer of homocysteine) and mixed cysteine-homocysteine disulfide. Homocyst(e)ine levels above 10.2 micro mol/L are associated with a doubling of coronary risk, and levels above 20 micro mol/L are associated with a 9.9-fold increase in risk compared with levels below 9 micro mol/L. The mechanisms by which homocyst(e)ine promotes vascular disease include increased thrombosis, consumption of nitric oxide, endothelial injury, and reduced thrombolysis. Homocyst(e)ine is an independent predictor of carotid atherosclerosis. Vitamin therapy with folate, pyridoxine (vitamin B(6)), and cyanocobalamin (vitamin B(12)) reduces blood levels of homocyst(e)ine, improves endothelial function, reduces levels of fibrinogen and lipoprotein(a), improves thrombolysis, and in uncontrolled clinical observation, leads to regression of carotid plaque. These lines of evidence support a causal relationship between homocyst(e)ine and atherosclerosis, and suggest that in patients with vascular disease, an appropriate target level for therapy may be below 9 or 10 micro mol/L. Randomized controlled studies are under way to determine whether vitamin therapy is effective in secondary prevention of myocardial infarction and stroke.

Betaine Phosphate (CH3)3N+CH2COO-.H3PO4 Modification Using D2O

International Nuclear Information System (INIS)

Saryati; Ridwan; Deswita; Sugiantoro, Sugik

2002-01-01

Betaine fosfate (CH 3 ) 3 N + CH 2 COO - .H 3 PO 4 modification by using D 2 O has been studied. This modification was carried out by slowly evaporation the saturated Betaine phosphat in the D 2 O solution in the dry box at 40 o C, until the dry crystal were formed. Based on the NMR data, can be concluded that the exchange process with D has been runed well and Betaine phosphate-D (CH 3 ) 3 N + CH 2 COO - .H 3 PO 4 has been resulted. From the X-ray diffraction pattern data can be concluded that there are a deference in the crystal structure between Betaine phosphate and Betaine phosphate modification result. From the Differential Scanning Colorimeter (DSC) diagram at the range temperature from 30 o C to 250 o C, can be shown that the Betaine phosphate-H has two endothermic transition phase, at 99 o C with a very little adsorbed calor and at 221.50 o C with -26.75 cal/g. Modified Betaine phosphate has also two endothermic transition phase, at 99.86 o C with -1.94 cal/g and at 171.01 o C with -3.48 cal/g. It can be conclosed that the D atom substitution on the H atoms in Betaine phosphate, to change the crystal and the endothermic fase temperature and energy

Proximate Composition, and -Carnitine and Betaine Contents in Meat from Korean Indigenous Chicken

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Samooel Jung

2015-12-01

Full Text Available This study investigated the proximate composition and l-carnitine and betaine content of meats from 5 lines of Korean indigenous chicken (KIC for developing highly nutritious meat breeds with health benefits from the bioactive compounds such as l-carnitine and betaine in meat. In addition, the relevance of gender (male and female and meat type (breast and thigh meat was examined. A total of 595 F1 progeny (black [B], grey-brown [G], red-brown [R], white [W], and yellow-brown [Y] from 70 full-sib families were used. The moisture, protein, fat, and ash contents of the meats were significantly affected by line, gender, and meat type (p<0.05. The males in line G and females in line B showed the highest protein and the lowest fat content of the meats. l-carnitine and betaine content showed effects of meat type, line, and gender (p<0.05. The highest l-carnitine content was found in breast and thigh meats from line Y in both genders. The breast meat from line G and the thigh meat from line R had the highest betaine content in males. The female breast and thigh meats showed the highest betaine content in line R. These data could be valuable for establishing selection strategies for developing highly nutritious chicken meat breeds in Korea.

Dietary Intake and Plasma Levels of Choline and Betaine in Children with Autism Spectrum Disorders

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Joanna C. Hamlin

2013-01-01

Full Text Available Abnormalities in folate-dependent one-carbon metabolism have been reported in many children with autism. Because inadequate choline and betaine can negatively affect folate metabolism and in turn downstream methylation and antioxidant capacity, we sought to determine whether dietary intake of choline and betaine in children with autism was adequate to meet nutritional needs based on national recommendations. Three-day food records were analyzed for 288 children with autism (ASDs who participated in the national Autism Intervention Research Network for Physical Health (AIR-P Study on Diet and Nutrition in children with autism. Plasma concentrations of choline and betaine were measured in a subgroup of 35 children with ASDs and 32 age-matched control children. The results indicated that 60–93% of children with ASDs were consuming less than the recommended Adequate Intake (AI for choline. Strong positive correlations were found between dietary intake and plasma concentrations of choline and betaine in autistic children as well as lower plasma concentrations compared to the control group. We conclude that choline and betaine intake is inadequate in a significant subgroup of children with ASDs and is reflected in lower plasma levels. Inadequate intake of choline and betaine may contribute to the metabolic abnormalities observed in many children with autism and warrants attention in nutritional counseling.

Enhancer of zeste homologue 2 plays an important role in neuroblastoma cell survival independent of its histone methyltransferase activity.

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Bate-Eya, Laurel T; Gierman, Hinco J; Ebus, Marli E; Koster, Jan; Caron, Huib N; Versteeg, Rogier; Dolman, M Emmy M; Molenaar, Jan J

2017-04-01

Neuroblastoma is predominantly characterised by chromosomal rearrangements. Next to V-Myc Avian Myelocytomatosis Viral Oncogene Neuroblastoma Derived Homolog (MYCN) amplification, chromosome 7 and 17q gains are frequently observed. We identified a neuroblastoma patient with a regional 7q36 gain, encompassing the enhancer of zeste homologue 2 (EZH2) gene. EZH2 is the histone methyltransferase of lysine 27 of histone H3 (H3K27me3) that forms the catalytic subunit of the polycomb repressive complex 2. H3K27me3 is commonly associated with the silencing of genes involved in cellular processes such as cell cycle regulation, cellular differentiation and cancer. High EZH2 expression correlated with poor prognosis and overall survival independent of MYCN amplification status. Unexpectedly, treatment of 3 EZH2-high expressing neuroblastoma cell lines (IMR32, CHP134 and NMB), with EZH2-specific inhibitors (GSK126 and EPZ6438) resulted in only a slight G1 arrest, despite maximum histone methyltransferase activity inhibition. Furthermore, colony formation in cell lines treated with the inhibitors was reduced only at concentrations much higher than necessary for complete inhibition of EZH2 histone methyltransferase activity. Knockdown of the complete protein with three independent shRNAs resulted in a strong apoptotic response and decreased cyclin D1 levels. This apoptotic response could be rescued by overexpressing EZH2ΔSET, a truncated form of wild-type EZH2 lacking the SET transactivation domain necessary for histone methyltransferase activity. Our findings suggest that high EZH2 expression, at least in neuroblastoma, has a survival function independent of its methyltransferase activity. This important finding highlights the need for studies on EZH2 beyond its methyltransferase function and the requirement for compounds that will target EZH2 as a complete protein. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vitamin intake: a possible determinant of plasma homocyst(e)ine among middle-aged adults.

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Shimakawa, T; Nieto, F J; Malinow, M R; Chambless, L E; Schreiner, P J; Szklo, M

1997-05-01

Many epidemiologic studies have identified elevated plasma homocyst(e)ine as a risk factor for atherosclerosis and thromboembolic disease. To examined the relationship between vitamin intakes and plasma homocyst(e)ine, we analyzed dietary intake data from a case-control study of 322 middle-aged individuals with atherosclerosis in the carotid artery and 318 control subjects without evidence of this disease. All of these individuals were selected from a probability sample of 15,800 men and women who participated in the Atherosclerosis Risk in Communities (ARIC) Study. Plasma homocyst(e)ine was inversely associated with intakes of folate, vitamin B6, and vitamin B12 (controls only for this vitamin)--the three key vitamins in homocyst(e)ine metabolism. Among nonusers of vitamin supplement products, on average each tertile increase in intake of these vitamins was associated with 0.4 to 0.7 mumol/L decrease in plasma homocyst(e)ine. An inverse association of plasma homocyst(e)ine was also found with thiamin, riboflavin, calcium, phosphorus, and iron. Methionine and protein intake did not show any significant association with plasma homocyst(e)ine. In almost all analyses, cases and controls showed similar associations between dietary variables and plasma homocyst(e)ine. Plasma homocyst(e)ine among users of vitamin supplement products was 1.5 mumol/L lower than that among nonusers. Further studies to examine possible causal relationships among vitamin intake, plasma homocyst(e)ine, and cardiovascular disease are needed.

Human catechol-O-methyltransferase: Cloning and expression of the membrane-associated form

International Nuclear Information System (INIS)

Bertocci, B.; Miggiano, V.; Da Prada, M.; Dembic, Z.; Lahm, H.W.; Malherbe, P.

1991-01-01

A cDNA clone for human catechol-O-methyltransferase was isolated from a human hepatoma cell line (Hep G2) cDNA library by hybridization screening with a porcine cDNA probe. The cDNA clone was sequenced and found to have an insert of 1226 nucleotides. The deduced primary structure of hCOMT is composed of 271 amino acid residues with the predicted molecular mass of 30 kDa. At its N terminus it has a hydrophobic segment of 21 amino acid residues that may be responsible for insertion of hCOMT into the endoplasmic reticulum membrane. The primary structure of hCOMT exhibits high homology to the porcine partial cDNA sequence (93%). The deduced amino acid sequence contains two tryptic peptide sequences (T-22, T-33) found in porcine liver catechol-O-methyltransferase (CEMT). The coding region of hCOMT cDNA was placed under the control of the cytomegalovirus promoter to transfect human kidney 293 cells. The recombinant hCOMT was shown by immunoblot analysis to be mainly associated with the membrane fraction. RNA blot analysis revealed one COMT mRNA transcript of 1.4 kilobases in Hep G2 poly(A) + RNA

Plasma homocyst(e)ine concentrations in eclamptic and preeclamptic African women postpartum.

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Rajkovic, A; Mahomed, K; Malinow, M R; Sorenson, T K; Woelk, G B; Williams, M A

1999-09-01

To examine the relationship between plasma homocyst(e)ine and risk of eclampsia and preeclampsia among sub-Saharan African women who delivered at Harare Maternity Hospital in Zimbabwe. We ran a hospital-based, case-control study at Harare Maternity Hospital, University of Zimbabwe, Harare, Zimbabwe comprising 33 pregnant women with eclampsia and 138 with preeclampsia. Controls were 185 normotensive pregnant women. Plasma was collected postpartum and homocyst(e)ine levels were measured by high-performance liquid chromatography and electrochemical detection. Women with eclampsia or preeclampsia had significantly higher mean homocyst(e)ine levels than normotensive controls (12.54 or 12.77 micromol/L versus 9.93 micromol/L, respectively, Pine distribution (median 13.9 micromol/L) compared with women in the lowest quartile (median 6.2 micromol/L). The corresponding OR for preeclampsia was 4.57. Nulliparas with elevated homocyst(e)ine had a 12.90 times higher risk of preeclampsia compared with multiparas without elevated homocyst(e)ine. Postpartum plasma homocyst(e)ine concentrations are higher among Zimbabwean women with eclampsia and preeclampsia compared with normotensive women.

Vitamin B6 and homocysteine levels in carbamazepine treated ...

African Journals Online (AJOL)

Objectives: The study focused on the plasma levels of vitamin B6 and homocysteine in ... ed with carbamazepine were selected at out-patient De- .... Patients' demographic data and types of seizures are ex- .... morphisms that may alter the individual response to a .... genotype, homocysteine, and stroke risk: a meta-analy-.

Homocyst(e)ine and atherosclerosis in patients on chronic hemodialysis.

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Lee, Y K; Kwon, Y J; Yoon, J W; Oh, K S; Cha, D R; Cho, W Y; Huh, K; Pyo, H J; Kim, H K

1999-04-01

Hyperhomocyst(e)inemia is an established risk factor for atherosclerosis. We performed this study to identify the correlating variables and risk factors for atherosclerosis, as measured by the atherosclerotic score (AS), and to determine the relative risk for cardiovascular disease in relation to plasma homocyst(e)ine levels in patients on chronic hemodialysis. We evaluated and measured 61 patients on chronic hemodialysis for clinical and biochemical parameters including atherosclerotic score (AS) and plasma homocyst(e)ine. We divided patients into high and low groups, first, by the mean AS, and second, by the median value of plasma total homocyst(e)ine levels. Then we compared the variables between the two groups. Out of the 61 patients, the median plasma total homocyst(e)ine level was 24.4 micromol/L (mean+/-SD, 27.7+/-17.4; range, 9.8-127.4 micromol/L), and the median AS was 5 (mean+/-SD, 6.2+/-2.8; range, 3-13) out of a possible 20 points. AS was significantly correlated with plasma total homocyst(e)ine levels (r=0.37) and age (r=0.67). Through multivariate analysis, plasma total homocyst(e)ine level and age were determined as significant risk factors for the high-AS group (pine level did not correlate with age (p>0.05). Eighteen of the 61 patients, presented with cardiovascular disease until the present study, had an AS>6. Cardiovascular disease was found more often in the high-homocyst(e)ine group (>24.4 micromol/L) than in the low-homocyst(e)ine group (odds ratio, 9.3; 95% confidence interval, 2.3-37.4). Regardless of age, hyperhomocyst(e)inemia (especially homocyst(e)ine levels >24.4 micromol/L) is a risk factor that can be modified for the development of cardiovascular disease in patients on chronic hemodialysis.

Effect of dimethylaminoethanol, an inhibitor of betaine production, on the disposition of choline in the rat kidney

International Nuclear Information System (INIS)

Lohr, J.; Acara, M.

1990-01-01

The choline metabolite betaine has been shown to be an important organic osmoregulatory solute in the kidney. The isolated perfused rat kidney and kidney slice incubations were used to investigate the effect of 2-dimethylaminoethanol (DMAE), a choline oxidase inhibitor, on the renal excretion and metabolism of choline. In the isolated perfused kidney, [ 14 C]choline, at an initial perfusate concentration of 300 microM, was effectively removed from the perfusate over 25 min, with nearly all the 14 C in the perfusate accounted for by betaine during the remainder of the 90-min perfusion. DMAE at concentrations of 3.0 or 5.0 mM significantly decreased the rate of removal of [ 14 C]choline from the perfusate and the rate of addition of [ 14 C]betaine to the perfusate, yet [14C]betaine remained the only metabolite of choline in perfusate and urine. In kidney tissue slice experiments, conversion of [ 14 C]choline to [ 14 C]betaine was found in cortical, outer medullary and inner medullary regions of rat kidney. DMAE at 5.0 mM significantly inhibited [ 14 C]betaine production in each of the three regions studied. These data show that DMAE is an effective inhibitor of betaine production by the kidney and, as such, may be an important agent for the study of osmoregulation by the kidney

Influence of folic acid, pyridoxal phosphate and cobalamin on plasma homocyst(e)ine levels and the susceptibility of low-density lipoprotein to ex-vivo oxidation.

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Weiss, N; Feussner, A; Hailer, S; Spengel, F A; Keller, C; Wolfram, G

1999-10-15

Mild hyperhomocyst(e)inaemia is a risk factor for atherosclerotic vascular disease. In-vitro studies have shown that autooxidation of homocyst(e)ine is accompanied by the generation of oxygen radicals. This may lead to oxidative modification of low-density lipoproteins (LDL) and promote atherosclerotic vascular lesions. In male patients with peripheral arterial occlusive disease we determined fasting and post methionine load homocyst(e)ine levels by high performance liquid chromatography and the susceptibility of their LDL particles to ex-vivo oxidation by continously measuring the conjugated diene production induced by incubation with copper ions. Oxidation resistance (expressed as lag time), maximal oxidation rate, and extent of oxidation (expressed of total diene production) of LDL from patients with normal or mildly elevated homocyst(e)ine levels did not differ significantly. Folic acid, pyridoxal phosphate and cobalamin supplementation significantly decreased plasma homocyst(e)ine levels in hyperhomocyst(e)inaemic patients. This went along with a significant decrease in the extent of LDL oxidation and additionally increased HDL-cholesterol levels. The clinical relevance of these findings for the long-term course of atherosclerotic vascular disorders has to be determined by intervention studies.

Selective electrochemical determination of homocysteine in the presence of cysteine and glutathione

International Nuclear Information System (INIS)

Salehzadeh, Hamid; Mokhtari, Banafsheh; Nematollahi, Davood

2014-01-01

Graphical abstract: 3,5-Di-tert-buthylcatechol was used for the selective electrochemical determination of homocysteine in the presence of cysteine and glutathione at the glassy carbon and carbon nanotube modified glassy carbon electrode. - Highlights: • Selective electrochemical determination of homocysteine. • Catalytic electron transfer of 3,5-di-tert-buthylcatechol in the presence of homocysteine. • Michael type addition reaction of electrochemically generated 3,5-di-tert-buthyl-o-benzoquinone with glutathione. - Abstract: The electrochemical oxidation of 3,5-di-tert-buthylcatechol in the presence of homocysteine was used for the selective electrochemical determination of homocysteine in the presence of cysteine and glutathione at a glassy carbon and a glassy carbon electrode modified with carbon nanotube. The results revealed that the electrochemically generated 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione exhibits high catalytic activity toward homocysteine oxidation at reduced over-potential and low catalytic activity for oxidation of cysteine. The catalytic activity 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione toward cysteine was suppressed in the presence of 4-N,N-dimethylaminocinnamaldehyde. Contrary to homocysteine and cysteine, the reaction of glutathione with 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione is a substituation reaction. This method exhibits three dynamic linear ranges of 2.5 to 10 μmol L −1 , 10 to 100 μmol L −1 and 100 to 1000 μmol L −1 , and a lower detection limit (3σ) of 0.89 ± 3.53% μmol L −1 for homocysteine

Genetics of homocysteine metabolism and associated disorders

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S. Brustolin

2010-01-01

Full Text Available Homocysteine is a sulfur-containing amino acid derived from the metabolism of methionine, an essential amino acid, and is metabolized by one of two pathways: remethylation or transsulfuration. Abnormalities of these pathways lead to hyperhomocysteinemia. Hyperhomocysteinemia is observed in approximately 5% of the general population and is associated with an increased risk for many disorders, including vascular and neurodegenerative diseases, autoimmune disorders, birth defects, diabetes, renal disease, osteoporosis, neuropsychiatric disorders, and cancer. We review here the correlation between homocysteine metabolism and the disorders described above with genetic variants on genes coding for enzymes of homocysteine metabolism relevant to clinical practice, especially common variants of the MTHFR gene, 677C>T and 1298A>C. We also discuss the management of hyperhomocysteinemia with folic acid supplementation and fortification of folic acid and the impact of a decrease in the prevalence of congenital anomalies and a decline in the incidence of stroke mortality.

Safety of betaine as a novel food pursuant to Regulation (EC) No 258/97

DEFF Research Database (Denmark)

Sjödin, Anders Mikael

2017-01-01

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on betaine as a novel food (NF) pursuant to Regulation (EC) No 258/97. The information provided on the composition, the specifications, the batch......-to-batch variability, stability and production process of the NF is sufficient and does not raise concerns about the safety of the NF. The NF is proposed to be used in foods intended to meet additional requirements for intense muscular effort with a maximum intake of 2.5 g/day of betaine for sports people above 10...... as not sufficient. However, the total exposure to betaine from the diet (about 830 mg/day) is not known to be associated with adverse effects. Moreover, no adverse effects on platelet counts were noted in human intervention studies with exposure levels of 4 g/day of betaine for up to 6 months. A significant...

Plasma Homocysteine is Not Related to the Severity of Microangiopathy in Secondary Raynaud Phenomenon

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Jacomella, Vincenzo; Wasila, Monika; Husmann, Marc; Gitzelmann, Gabriela; Meier, Thomas; Amann-Vesti, Beatrice

2011-01-01

Introduction: The role of elevated homocysteine in primary and secondary Raynaud phenomenon (RP) and in patients with atherosclerosis has been reported controversially. In secondary RP due to connective tissue disease specific alterations of nailfold capillaries might be present. An association between these microvascular changes and homocysteine has been suggested. Aim: The aim of this study was to determine whether homocysteine level differs between patients with primary and secondary RP and to test the hypothesis that homocysteine or other cardiovascular risk factors are associated with specific features of microangiopathy in secondary RP. Patients and Methods Eighty-one consecutive patients with RP referred for vascular assessment were studied by nailfold capillaroscopy. Homocysteine, C-reactive protein and cholesterol were measured and other cardiovascular risk factors and comorbidities assessed. Results: Homocysteine, C-reactive-protein and cholesterol levels did not differ between patients with primary (n=60) and secondary RP (n=21). Likewise, no differences in the prevalence of cardiovascular risk factors and comorbidities were found. In secondary RP no correlation was found between microvascular involvement and homocysteine or C-reactive protein. Conclusion: Plasma homocysteine is not different in patients with either primary or secondary RP and is therefore not a marker for the distinction of these diseases. The extent of microvascular involvement in secondary RP does not correlate with plasma homocysteine. PMID:22216066

Plasma homocysteine level in cardiac syndrome X and its relation with duke treadmill score

International Nuclear Information System (INIS)

Timurkaynak, T.; Balcioglu, S.; Arslan, U.; Kocaman, Sinan A.; Cengel, A.

2008-01-01

Objective was to investigate the plasma homocysteine level and relationship between plasma homocysteine level and duke treadmill score (DTS) in cardiac syndrome X (CSX) patients. Seventy-nine patients (36 male, 43 female, mean age: 50+-8.8 years) admitted to Gazi University Hospital, Ankara, Turkey with typical effort angina, positive stress test and angiographically normal coronary arteries between January and September 2006 were included in this prospective and controlled study. Thirty asymptomatic patients (11 male, 19 female, mean age: 47.6+-8.3 years) with two cardiovascular risk factors were chosen as a control group. Plasma homocysteine level was measured in both groups and DTS was calculated in the CSX group. Plasma homocysteine was measured with AxSYM homocysteine immunoassay method in both groups. Plasma homocysteine level was higher in the CSx group compared to the control group 16.5+-4.9 umol/L, n=79, versus 12.4+-4.1 umol/L, n=30, p<0.001). The DTS was -2.7+-5.3 in the CSX group. There was a negative correlation between the DTS and homocysteine levels in the CSX group. (r=-0.506, p<0.001). Plasma homocysteine level, which is known to cause endothelial dysfunction and microvascular ischemia were higher in CSX patients. Also, this increase in homocysteine level correlated with the DTS, which represents the magnitude of ischemia. (author)

Status of Homocysteine in Polycystic Ovary Syndrome (PCOS)

OpenAIRE

Maleedhu, Priyanka; M., Vijayabhaskar; S.S.B., Sharma; Kodumuri, Praveen K; Devi D., Vasundhara

2014-01-01

Background: Polycystic ovary syndrome (PCOS) is the most common endocrine disease in women of reproductive age and is estimated to affect 5-10 % of the population. Women with PCOS have a clustering of cardiovascular risk factors, such as obesity, dyslipidemia, impaired glucose tolerance and hypertension. Homocysteine has been recognized recently as a risk factor for cardiovascular diseases. Preliminary investigations suggest that high sensitivity C-reactive protein, homocysteine and adiponect...

Homocysteine and brain atrophy on MRI of non-demented elderly

NARCIS (Netherlands)

den Heijer, T; Vermeer, SE; Clarke, R; Oudkerk, M; Koudstaal, PJ; Hofman, A; Breteler, MMB

Patients with Alzheimer's disease have higher plasma homocysteine levels than controls, but it is uncertain whether higher plasma homocysteine levels are involved in the early pathogenesis of the disease. Hippocampal, amygdalar and global brain atrophy on brain MRI have been proposed as early

Survival and Psychomotor Development With Early Betaine Treatment in Patients With Severe Methylenetetrahydrofolate Reductase Deficiency

NARCIS (Netherlands)

Diekman, Eugene F.; de Koning, Tom J.; Verhoeven-Duif, Nanda M.; Rovers, Maroeska M.; van Hasselt, Peter M.

IMPORTANCE The impact of betaine treatment on outcome in patients with severe methylenetetrahydrofolate reductase (MTHFR) deficiency is presently unclear. OBJECTIVE To investigate the effect of betaine treatment on development and survival in patients with severe MTHFR deficiency. DATA SOURCES

Survival and psychomotor development with early betaine treatment in patients with severe methylenetetrahydrofolate reductase deficiency

NARCIS (Netherlands)

Diekman, E.F.; Koning, T.J. de; Verhoeven-Duif, N.M.; Rovers, M.M.; Hasselt, P.M. van

2014-01-01

IMPORTANCE The impact of betaine treatment on outcome in patients with severe methylenetetrahydrofolate reductase (MTHFR) deficiency is presently unclear. OBJECTIVE To investigate the effect of betaine treatment on development and survival in patients with severe MTHFR deficiency. DATA SOURCES

Short-term folic acid supplementation induces variable and paradoxical changes in plasma homocyst(e)ine concentrations.

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Malinow, M R; Duell, P B; Williams, M A; Kruger, W D; Evans, A A; Anderson, P H; Block, P C; Hess, D L; Upson, B M; Graf, E E; Irvin-Jones, A; Wang, L

2001-01-01

Folic acid is presently the mainstay of treatment for most subjects with elevated plasma homocyst(e)ine concentrations [Plasma or serum homocyst(e)ine, or total homocysteine, refers to the sum of the sulfhydryl amino acid homocysteine and the homocysteinyl moieties of the disulfides homocystine and homocystein-cysteine, whether free or bound to plasma proteins.] Changes in homocyst(e)ine in response to folic acid supplementation are characterized by considerable interindividual variation. The purpose of this study was to identify factors that contribute to heterogeneity in short-term responses to folic acid supplementation. The effects of folic acid supplementation (1 or 2 mg per day) for 3 wk on plasma homocyst(e)ine concentrations were assessed in 304 men and women. Overall, folic acid supplementation increased mean plasma folate 31.5 +/- 98.0 nmol/L and decreased mean plasma homocyst(e)ine concentrations 1.2 +/- 2.4 micromol/L. There was evidence of substantial interindividual variation in the homocyst(e)ine response from -18.5 to +7.1 micromol/L, including an increase in homocyst(e)ine in 20% of subjects (mean increase 1.5 +/- 1.4 micromol/L). Basal homocyst(e)ine, age, male gender, cigarette smoking, use of multivitamins, methylene tetrahydrofolate reductase, and cystathionine beta-synthase polymorphisms accounted for 47.6% of the interindividual variability in the change in homocyst(e)ine after folic acid supplementation, but about 50% of variability in response to folic acid was not explained by the variables we studied.

Simultaneous, noninvasive, and transdermal extraction of urea and homocysteine by reverse iontophoresis

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et al

2011-02-01

Full Text Available Congo Tak-Shing Ching1,2,3, Tzong-Ru Chou1, Tai-Ping Sun1,2, Shiow-Yuan Huang3, Hsiu-Li Shieh21Graduate Institute of Biomedicine and Biomedical Technology; 2Department of Electrical Engineering, National Chi Nan University, Nantou, Taiwan; 3Department of Photonics and Communication Engineering, Asia University, Taichung, Taiwan, Republic of ChinaBackground: Cardiovascular and kidney diseases are a global public health problem and impose a huge economic burden on health care services. Homocysteine, an amino acid, is associated with coronary heart disease, while urea is a harmful metabolic substance which can be used to reflect kidney function. Monitoring of these two substances is therefore very important. This in vitro study aimed to determine whether homocysteine is extractable transdermally and noninvasively, and whether homocysteine and urea can be extracted simultaneously by reverse iontophoresis.Methods: A diffusion cell incorporated with porcine skin was used for all experiments with the application of a direct current (dc and four different symmetrical biphasic direct currents (SBdc for 12 minutes via Ag/AgCl electrodes. The dc and the SBdc had a current density of 0.3 mA/cm2.Results: The SBdc has four different phase durations of 15 sec, 30 sec, 60 sec, and 180 sec. It was found that homocysteine can be transdermally extracted by reverse iontophoresis. Simultaneous extraction of homocysteine and urea by reverse iontophoresis is also possible.Conclusion: These results suggest that extraction of homocysteine and urea by SBdc are phase duration-dependent, and the optimum mode for simultaneous homocysteine and urea extraction is the SBdc with the phase duration of 60 sec.Keywords: reverse iontophoresis, homocysteine, urea, monitoring, noninvasive, transdermal

MOLECULAR MODELING INDICATES THAT HOMOCYSTEINE INDUCES CONFORMATIONAL CHANGES IN THE STRUCTURE OF PUTATIVE TARGET PROTEINS

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Yumnam Silla

2015-09-01

Full Text Available An elevated level of homocysteine, a reactive thiol containing amino acid is associated with a multitude of complex diseases. A majority (>80% of homocysteine in circulation is bound to protein cysteine residues. Although, till date only 21 proteins have been experimentally shown to bind with homocysteine, using an insilico approach we had earlier identified several potential target proteins that could bind with homocysteine. Shomocysteinylation of proteins could potentially alter the structure and/or function of the protein. Earlier studies have shown that binding of homocysteine to protein alters its function. However, the effect of homocysteine on the target protein structure has not yet been documented. In the present work, we assess conformational or structural changes if any due to protein homocysteinylation using two proteins, granzyme B (GRAB and junctional adhesion molecule 1 (JAM1, which could potentially bind to homocysteine. We, for the first time, constructed computational models of homocysteine bound to target proteins and monitored their structural changes using explicit solvent molecular dynamic (MD simulation. Analysis of homocysteine bound trajectories revealed higher flexibility of the active site residues and local structural perturbations compared to the unbound native structure’s simulation, which could affect the stability of the protein. In addition, secondary structure analysis of homocysteine bound trajectories also revealed disappearance of â-helix within the G-helix and linker region that connects between the domain regions (as defined in the crystal structure. Our study thus captures the conformational transitions induced by homocysteine and we suggest these structural alterations might have implications for hyperhomocysteinemia induced pathologies.

Tetra primer ARMS-PCR relates folate/homocysteine pathway genes and ACE gene polymorphism with coronary artery disease.

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Masud, Rizwan; Qureshi, Irfan Zia

2011-09-01

Cardiovascular disorders and coronary artery disease (CAD) are significant contributors to morbidity and mortality in heart patients. As genes of the folate/homocysteine pathway have been linked with the vascular disease, we investigated association of these gene polymorphisms with CAD/myocardial infarction (MI) using the novel approach of tetraprimer ARMS-PCR. A total of 230 participants (129 MI cases, 101 normal subjects) were recruited. We genotyped rs1801133 and rs1801131 SNPs in 5'10' methylenetetrahydrofolate reductase (MTHFR), rs1805087 SNP in 5' methyltetrahydrofolate homocysteine methyltransferase (MTR), rs662 SNP in paroxanse1 (PON1), and rs5742905 polymorphism in cystathionine beta synthase (CBS). Angiotensin converting enzyme (ACE) insertion/deletion polymorphism was detected through conventional PCR. Covariates included blood pressure, fasting blood sugar, serum cholesterol, and creatinine concentrations. Our results showed allele frequencies at rs1801133, rs1801131, rs1805087 and the ACE insertion/deletion (I/D) polymorphism varied between cases and controls. Logistic regression, after adjusting for covariates, demonstrated significant associations of rs1801133 and rs1805087 with CAD in the additive, dominant, and genotype model. In contrast, ACE I/D polymorphism was significantly related with CAD where recessive model was applied. Gene-gene interaction against the disease status revealed two polymorphism groups: rs1801133, rs662, and rs1805087; and rs1801131, rs662, and ACE I/D. Only the latter interaction maintained significance after adjusted for covariates. Our study concludes that folate pathway variants exert contributory influence on susceptibility to CAD. We further suggest that tetraprimer ARMS-PCR successfully resolves the genotypes in selected samples and might prove to be a superior technique compared to the conventional approach.

Production of Se-methylselenocysteine in transgenic plants expressing selenocysteine methyltransferase

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Harris Hugh

2004-01-01

Full Text Available Abstract Background It has become increasingly evident that dietary Se plays a significant role in reducing the incidence of lung, colorectal and prostate cancer in humans. Different forms of Se vary in their chemopreventative efficacy, with Se-methylselenocysteine being one of the most potent. Interestingly, the Se accumulating plant Astragalus bisulcatus (Two-grooved poison vetch contains up to 0.6% of its shoot dry weight as Se-methylselenocysteine. The ability of this Se accumulator to biosynthesize Se-methylselenocysteine provides a critical metabolic shunt that prevents selenocysteine and selenomethionine from entering the protein biosynthetic machinery. Such a metabolic shunt has been proposed to be vital for Se tolerance in A. bisulcatus. Utilization of this mechanism in other plants may provide a possible avenue for the genetic engineering of Se tolerance in plants ideally suited for the phytoremediation of Se contaminated land. Here, we describe the overexpression of a selenocysteine methyltransferase from A. bisulcatus to engineer Se-methylselenocysteine metabolism in the Se non-accumulator Arabidopsis thaliana (Thale cress. Results By over producing the A. bisulcatus enzyme selenocysteine methyltransferase in A. thaliana, we have introduced a novel biosynthetic ability that allows the non-accumulator to accumulate Se-methylselenocysteine and γ-glutamylmethylselenocysteine in shoots. The biosynthesis of Se-methylselenocysteine in A. thaliana also confers significantly increased selenite tolerance and foliar Se accumulation. Conclusion These results demonstrate the feasibility of developing transgenic plant-based production of Se-methylselenocysteine, as well as bioengineering selenite resistance in plants. Selenite resistance is the first step in engineering plants that are resistant to selenate, the predominant form of Se in the environment.

Effect of natural betaine and ractopamine HCl on whole-body and carcass growth in pigs housed under high ambient temperatures.

Science.gov (United States)

Mendoza, S M; Boyd, R D; Zier-Rush, C E; Ferket, P R; Haydon, K D; van Heugten, E

2017-07-01

Betaine is an osmolyte that helps to maintain water homeostasis and cell integrity, which is essential during heat stress. We hypothesized that supplemental betaine can improve growth during heat stress and may further improve the response to ractopamine. Two studies were conducted to determine: 1) the effects of betaine in combination with ractopamine; and 2) the optimum betaine level for late finishing pigs during heat stress. Heat stress was imposed by gradually increasing temperatures over 10 d to the target high temperature of 32°C. In Exp. 1, pigs ( = 1477, BW = 91.6 ± 3 kg) were assigned within BW blocks and sex to 1 of 4 diets arranged in a 2 × 2 factorial RCB design (68 pens; 20 to 23 pigs/pen). Treatments consisted of diets without or with ractopamine (5 mg/kg for 21 d followed by 8.8 mg/kg to market) and each were supplemented with either 0 or 0.2% of betaine. Betaine reduced ( ≤ 0.05) BW (123.1 vs. 124.3 kg), ADG (0.780 vs. 0.833 kg/d), and ADFI (2.800 vs. 2.918 kg/d), but did not impact carcass characteristics. Ractopamine increased ( treatments in a RCB design (100 pens; 20 to 24 pigs/pen). Treatments consisted of diets with 0, 0.0625, 0.125, 0.1875% of betaine, and a positive control diet with ractopamine, but not betaine. Betaine tended to decrease carcass yield quadratically ( = 0.076; 74.1, 73.5, 73.8, and 73.9 for 0, 0.0625, 0.125, 0.1875% of betaine, respectively), but did not impact other responses. Ractopamine improved ( stress makes it an important production technology.

The genome-wide identification and transcriptional levels of DNA methyltransferases and demethylases in globe artichoke.

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Gianoglio, Silvia; Moglia, Andrea; Acquadro, Alberto; Comino, Cinzia; Portis, Ezio

2017-01-01

Changes to the cytosine methylation status of DNA, driven by the activity of C5 methyltransferases (C5-MTases) and demethylases, exert an important influence over development, transposon movement, gene expression and imprinting. Three groups of C5-MTase enzymes have been identified in plants, namely MET (methyltransferase 1), CMT (chromomethyltransferases) and DRM (domains rearranged methyltransferases). Here the repertoire of genes encoding C5-MTase and demethylase by the globe artichoke (Cynara cardunculus var. scolymus) is described, based on sequence homology, a phylogenetic analysis and a characterization of their functional domains. A total of ten genes encoding C5-MTase (one MET, five CMTs and four DRMs) and five demethylases was identified. An analysis of their predicted product's protein structure suggested an extensive level of conservation has been retained by the C5-MTases. Transcriptional profiling based on quantitative real time PCR revealed a number of differences between the genes encoding maintenance and de novo methyltransferases, sometimes in a tissue- or development-dependent manner, which implied a degree of functional specialization.

The genome-wide identification and transcriptional levels of DNA methyltransferases and demethylases in globe artichoke.

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Silvia Gianoglio

Full Text Available Changes to the cytosine methylation status of DNA, driven by the activity of C5 methyltransferases (C5-MTases and demethylases, exert an important influence over development, transposon movement, gene expression and imprinting. Three groups of C5-MTase enzymes have been identified in plants, namely MET (methyltransferase 1, CMT (chromomethyltransferases and DRM (domains rearranged methyltransferases. Here the repertoire of genes encoding C5-MTase and demethylase by the globe artichoke (Cynara cardunculus var. scolymus is described, based on sequence homology, a phylogenetic analysis and a characterization of their functional domains. A total of ten genes encoding C5-MTase (one MET, five CMTs and four DRMs and five demethylases was identified. An analysis of their predicted product's protein structure suggested an extensive level of conservation has been retained by the C5-MTases. Transcriptional profiling based on quantitative real time PCR revealed a number of differences between the genes encoding maintenance and de novo methyltransferases, sometimes in a tissue- or development-dependent manner, which implied a degree of functional specialization.

[Homocystein serum levels and lipid parameters in children with atherosclerosis risk factors].

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Sierakowska-Fijałek, Anna; Kaczmarek, Piotr; Pokoca, Lech; Smorag, Ireneusz; Wosik-Erenbek, Marzenna; Baj, Zbigniew

2007-02-01

Atherosclerosis is a disease of adult patients, however, it begins in childhood and progresses from fatty streaks to raised lesions in arteries in adolescence and young adults. Clinical manifestation of atherosclerosis in adulthood depends on the risk factors such as: lipid disorders, obesity, hypertension, smoking habits and family history of CHD. High serum homocysteine concentration is increasingly recognised as a new risk factor for atherosclerosis and other vascular diseases. Atherogenic effect of homocystein is related to cytotoxin action on the endothelial cells and their function. The aim of this study was to estimate relations between the homocysteine serum concentration and the lipid levels in children with atherosclerosis risk factors. The study was carried out on 48 children with atherosclerosis risk factors. The control group consisted of 25 healthy childrens. Total cholesterol (TC), Triglycerides (TG), HDL-C, LDL-C were determined by enzymatic method. Concentration of homocysteine was estimated by immunoenzymatic method (ELISA). Obesity, lipid disorders, and hypertension were the most frequent risk factors in the investigated children. Statistically significant higher concentration of TC, LDL-C, TG and lower HDL-C were observed in children with atherosclerosis risk factors. No significant differences in homocystein concentration were observed in the investigated groups, but homocystein concentration was significantly higher in group of children with atherosclerosis risk factors. We observed that increased number of the risk factors is followed by high homocystein concentration in the serum.

Identification of Aquifex aeolicus tRNA (m2(2G26) methyltransferase gene.

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Takeda, Hiroshi; Hori, Hiroyuki; Endo, Yaeta

2002-01-01

The modifications of N2,N2-dimethylguanine (m2(2)G) are found in tRNAs and rRNAs from eukarya and archaea. In tRNAs, modification at position G26 is generated by tRNA (m2(2)G26) methyltransferase, which is encoded by the corresponding gene, trm1. This enzyme catalyzes the methyl-transfer from S-adenosyl-L-methionine to the semi-conserved residue, G26, via the intermediate modified base, m2G26. Recent genome sequencing project has been reported that the putative trm1 is encoded in the genome of Aquifex aeolicus, a hyper-thermophilic eubacterium as only one exception among eubacteria. In order to confirm whether this bacterial trm1 gene product is a real tRNA (m2(2)G26) methyltransferase or not, we expressed this protein by wheat germ in vitro cell-free translation system. Our biochemical analysis clearly showed that this gene product possessed tRNA (m2(2)G26) methyltransferase activity.

Plasma folic acid cutoff value, derived from its relationship with homocyst(e)ine

NARCIS (Netherlands)

Brouwer, D A; Welten, H T; Reijngoud, D J; van Doormaal, J J; Muskiet, F A

We established the cutoff value for plasma folic acid, using plasma homocyst(e)ine as the functional marker. To do this, we investigated the relationship of the plasma folic acid of 103 apparently healthy adults with their fasting plasma homocyst(e)ine and with their plasma homocyst(e)ine 6 h after

An O-Methyltransferase Is Required for Infection of Tick Cells by Anaplasma phagocytophilum.

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Oliva Chávez, Adela S; Fairman, James W; Felsheim, Roderick F; Nelson, Curtis M; Herron, Michael J; Higgins, LeeAnn; Burkhardt, Nicole Y; Oliver, Jonathan D; Markowski, Todd W; Kurtti, Timothy J; Edwards, Thomas E; Munderloh, Ulrike G

2015-01-01

Anaplasma phagocytophilum, the causative agent of Human Granulocytic Anaplasmosis (HGA), is an obligately intracellular α-proteobacterium that is transmitted by Ixodes spp ticks. However, the pathogen is not transovarially transmitted between tick generations and therefore needs to survive in both a mammalian host and the arthropod vector to complete its life cycle. To adapt to different environments, pathogens rely on differential gene expression as well as the modification of proteins and other molecules. Random transposon mutagenesis of A. phagocytophilum resulted in an insertion within the coding region of an o-methyltransferase (omt) family 3 gene. In wild-type bacteria, expression of omt was up-regulated during binding to tick cells (ISE6) at 2 hr post-inoculation, but nearly absent by 4 hr p.i. Gene disruption reduced bacterial binding to ISE6 cells, and the mutant bacteria that were able to enter the cells were arrested in their replication and development. Analyses of the proteomes of wild-type versus mutant bacteria during binding to ISE6 cells identified Major Surface Protein 4 (Msp4), but also hypothetical protein APH_0406, as the most differentially methylated. Importantly, two glutamic acid residues (the targets of the OMT) were methyl-modified in wild-type Msp4, whereas a single asparagine (not a target of the OMT) was methylated in APH_0406. In vitro methylation assays demonstrated that recombinant OMT specifically methylated Msp4. Towards a greater understanding of the overall structure and catalytic activity of the OMT, we solved the apo (PDB_ID:4OA8), the S-adenosine homocystein-bound (PDB_ID:4OA5), the SAH-Mn2+ bound (PDB_ID:4PCA), and SAM- Mn2+ bound (PDB_ID:4PCL) X-ray crystal structures of the enzyme. Here, we characterized a mutation in A. phagocytophilum that affected the ability of the bacteria to productively infect cells from its natural vector. Nevertheless, due to the lack of complementation, we cannot rule out secondary mutations.

An O-Methyltransferase Is Required for Infection of Tick Cells by Anaplasma phagocytophilum.

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Adela S Oliva Chávez

Full Text Available Anaplasma phagocytophilum, the causative agent of Human Granulocytic Anaplasmosis (HGA, is an obligately intracellular α-proteobacterium that is transmitted by Ixodes spp ticks. However, the pathogen is not transovarially transmitted between tick generations and therefore needs to survive in both a mammalian host and the arthropod vector to complete its life cycle. To adapt to different environments, pathogens rely on differential gene expression as well as the modification of proteins and other molecules. Random transposon mutagenesis of A. phagocytophilum resulted in an insertion within the coding region of an o-methyltransferase (omt family 3 gene. In wild-type bacteria, expression of omt was up-regulated during binding to tick cells (ISE6 at 2 hr post-inoculation, but nearly absent by 4 hr p.i. Gene disruption reduced bacterial binding to ISE6 cells, and the mutant bacteria that were able to enter the cells were arrested in their replication and development. Analyses of the proteomes of wild-type versus mutant bacteria during binding to ISE6 cells identified Major Surface Protein 4 (Msp4, but also hypothetical protein APH_0406, as the most differentially methylated. Importantly, two glutamic acid residues (the targets of the OMT were methyl-modified in wild-type Msp4, whereas a single asparagine (not a target of the OMT was methylated in APH_0406. In vitro methylation assays demonstrated that recombinant OMT specifically methylated Msp4. Towards a greater understanding of the overall structure and catalytic activity of the OMT, we solved the apo (PDB_ID:4OA8, the S-adenosine homocystein-bound (PDB_ID:4OA5, the SAH-Mn2+ bound (PDB_ID:4PCA, and SAM- Mn2+ bound (PDB_ID:4PCL X-ray crystal structures of the enzyme. Here, we characterized a mutation in A. phagocytophilum that affected the ability of the bacteria to productively infect cells from its natural vector. Nevertheless, due to the lack of complementation, we cannot rule out secondary

Increased CSF Homocysteine in Pathological Gamblers Compared with Healthy Controls

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Nordin, Conny; Sjodin, Ingemar

2009-01-01

Neurocognitive disturbances suggesting a frontal lobe dysfunction have been observed in pathological gamblers and alcohol dependents. Given that a high homocysteine level has been suggested to be a mediating factor in alcohol-related cognitive decline, we have determined homocysteine and cobalamine in cerebrospinal fluid (CSF) obtained from 11…

Association between serum homocysteine concentration with coronary artery disease in Iranian patients

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Ahmad Mirdamadi

2011-07-01

Full Text Available BACKGROUND: The role of novel biomarkers like homocystein as a risk factor of coronary artery disease (CAD is being increasingly recognized. There is a marked geographical variation in plasma homocystein concentration. In spite of importance of hyperhomocysteinemia in CAD risk, there is a paucity of studies in Iran that evaluate it. Consequently, we evaluated the association between plasma total homocystein (tHcy concentration and CAD risk in an Iranian population.METHODS: In a case-control study, we compared the level of tHcy of forty five patients with angiographically proved CAD with forty five age and gender matched subjects without CAD as control group. The patients with diabetes, hypertension, thyroid dysfunction, chronic renal failure, hyperlipidemia and obesity and other conventional CAD risk factors were excluded from the study. Plasma tHcy was measured using immunoturbidimetry. RESULTS: Homocystein level was higher in men than women (16.7 ± 5.2 versus 14.3 ± 3.9 micromol/lit, P = 0.019. CAD patients had higher mean plasma tHcy than control group (17.1 ± 5.3 versus 14.2 ± 3.8 micromol/lit, P = 0.004. CONCLUSION: This study denoted that high plasma homocystein concentration is associated with CAD risk in Iranian people. Keywords: Coronary Artery Disease, Homocystein, Iran.

Genome-wide identification and comparative analysis of cytosine-5 DNA methyltransferases and demethylase families in wild and cultivated peanut

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Pengfei eWang

2016-02-01

Full Text Available AbstractDNA methylation plays important roles in genome protection, regulation of gene expression and was associated with plants development. Plant DNA methylation pattern was mediated by cytosine-5 DNA methyltransferases and demethylase. Although the genomes of AA and BB wild peanuts have been fully sequence, these two gene families have not been studied. In this study we report the identification and analysis of putative cytosine-5 DNA methyltransferases (C5-MTases and demethylase in AA and BB wild peanuts. Cytosine-5 DNA methyltransferases in AA and BB wild peanuts could be classified in known MET, CMT and DRM2 groups based on their domain organization. This result was supported by the gene and protein structural characteristics and phylogenetic analysis. We found that some wild peanut DRM2 numbers didn’t contain UBA domain which was different from other plants such as Arabidopsis, maize, soybean. Five DNA demethylase were found in AA genome and five in BB genome. The selective pressure analysis showed that wild peanut C5-MTases gene mainly underwent purifying selection but many positive selection sites can be detected. Conversely, DNA demethylase genes mainly underwent positive selection during evolution. Additionally, the expression dynamic of cytosine-5 DNA methyltransferases and demethylase genes in different cultivated peanut tissues were analyzed. Expression result showed that cold, heat or drought stress could influence the expression level of C5-MTases and DNA demethylase genes in cultivated peanut. These results are useful for better understanding the complexity of these two gene families, and will facilitate epigenetic studies in peanut.

Variability of fasting and post-menthionine plasma homocysteine levels in normo- and hyperhomocysteinaemic individuals

NARCIS (Netherlands)

van den Berg, M.; de Jong, S.C.; Devilli, W.; Rauwerda, J.A.; Jakobs, C.A.J.M.; Pals, G.; Boers, G.H.J.; Stehouwer, C.D.A.

1999-01-01

To assess the variability of plasma homocysteine levels, fasting and post-methionine homocysteine levels were measured twice, at baseline and after follow-up of 1-4 months, in 16 individuals with normal and 26 with elevated homocysteine levels after methionine loading. The intra-individual

The relationship between cholesterol and cognitive function is homocysteine-dependent

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Cheng YB

2014-10-01

Full Text Available Yibin Cheng,1 Yinlong Jin,1 Frederick W Unverzagt,2 Liqin Su,1 Lili Yang,3 Feng Ma,1 Ann M Hake,4,5 Carla Kettler,3 Chen Chen,1 Jingyi Liu,1 Jianchao Bian,6 Ping Li,7 Jill R Murrell,8 Hugh C Hendrie,2,9,10 Sujuan Gao3 1Institute for Environmental Health and Related Product Safety, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China; 2Department of Psychiatry, 3Department of Biostatistics, 4Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana, USA; 5Eli Lilly and Company, Indianapolis, Indiana, USA; 6Shandong Institute for Prevention and Treatment of Endemic Disease in China, Jinan, People’s Republic of China; 7Sichuan Provincial Center for Disease Control and Prevention in China, Chengdu, People’s Republic of China; 8Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 9Indiana University Center for Aging Research, 10Regenstrief Institute, Inc., Indianapolis, Indiana, USA Introduction: Previous studies have identified hyperlipidemia as a potential risk factor for dementia and Alzheimer’s disease. However, studies on cholesterol measured in late-life and cognitive function have been inconsistent. Few studies have explored nonlinear relationships or considered interactions with other biomarker measures.Methods: A cross-sectional sample of 1,889 participants from four rural counties in the People’s Republic of China was included in this analysis. Serum total cholesterol, high-density lipoprotein, triglycerides, and homocysteine levels were measured in fasting blood samples. A composite cognitive score was derived based on nine standardized cognitive test scores. Analysis of covariance models were used to investigate the association between biomarker measures and the composite cognitive scores.Results: There was a significant interaction between the homocysteine quartile group and the cholesterol quartile group on cognitive scores (P=0

Relationship Between Plasma Homocystein Levels and Polyneuropaty in Patients Using Levodopa For Idiopathic Parkinson’s Disease

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Mithat Bedir

2012-06-01

Full Text Available Objective: Recent studies showed high plasma homocysteine levels in patients treated with Levodopa for Parkinson’s disease (PD. Homocysteine, due to its exotoxic effect, might be the cause of polyneuropathy seen in PD. In this study, our aim was to show the correlation between high concentration of plasma homocysteine levels and polyneuropathy associated with PD.. Material and Methods: Forty-one patients with PD receiving levodopa treatment (patient group and 30 healthy subjects (control group were included in this study. We compared the two groups in terms of electrophysiological findings. Twelve patients had high plasma homocysteine levels and 29 of them had low plasma homocysteine levels. Results: Six of the 41 patients had sensorial polyneuropathy and decreased compound muscle action potantiel amplitude compared to controls. Two patients had high plasma homocysteine levels, two patients had nearly high plasma homocysteine levels, two patients had low plasma homocysteine levels who had sensorial polyneuropathy. Conclusion: Although in our study, we did not show any correlation between polyneuropathy and high plasma homocysteine levels, further studies including homogeneous groups of younger patients with PD are needed. (The Me di cal Bul - le tin of Ha se ki 2012; 50: 53-8

Do cysteine residues regulate transient receptor potential canonical type 6 (TRPC6) channel protein expression?

DEFF Research Database (Denmark)

Thilo, Florian; Liu, Ying; Krueger, Katharina

2012-01-01

The regulation of calcium influx through transient receptor potential canonical type 6 channel is mandatory for the activity of human monocytes. We submit the first evidence that cysteine residues of homocysteine or acetylcysteine affect TRPC6 expression in human monocytes. We observed that patie......The regulation of calcium influx through transient receptor potential canonical type 6 channel is mandatory for the activity of human monocytes. We submit the first evidence that cysteine residues of homocysteine or acetylcysteine affect TRPC6 expression in human monocytes. We observed...... that patients with chronic renal failure had significantly elevated homocysteine levels and TRPC6 mRNA expression levels in monocytes compared to control subjects. We further observed that administration of homocysteine or acetylcysteine significantly increased TRPC6 channel protein expression compared...... to control conditions. We therefore hypothesize that cysteine residues increase TRPC6 channel protein expression in humans....

Correlation between Behavioural and Psychological Symptoms of Alzheimer Type Dementia and Plasma Homocysteine Concentration

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Zhanjie Zheng

2014-01-01

Full Text Available The relationship between plasma homocysteine and behavioral and psychological symptoms of dementia (BPSD has not been specifically investigated in previous research. In this study, we compared plasma homocysteine (Hcy among 40 Alzheimer’s disease (AD patients with BPSD, 37 AD patients without BPSD, and 39 healthy controls. Our results evidenced that the plasma homocysteine levels in AD patients with BPSD and without BPSD were higher than healthy controls and that the plasma homocysteine concentration in AD patients with BPSD was the highest among the three groups. Significant correlation between plasma homocysteine concentration and cognitive decline and duration of dementia was observed, but there was no correlation between BPSD and cognitive dysfunction or duration of dementia. In conclusion, this study showed for the first time that BPSD were associated with plasma homocysteine concentration in Alzheimer's dementia, and the results supported that hyperhomocysteine may take part in the pathogenesis of BPSD.

Protein Arginine Methyltransferase 5 Inhibition Upregulates Foxp3+ Regulatory T Cells Frequency and Function during the Ulcerative Colitis

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Yingxia Zheng

2017-05-01

Full Text Available Ulcerative colitis (UC pathogenesis is related to imbalance of immune responses, and the equilibrium between inflammatory T cells and Foxp3+ regulatory T cells (Tregs plays an important role in the intestinal homeostasis. Protein arginine methyltransferases (PRMTs regulate chromatin remodeling and gene expression. Here, we investigated whether inhibition of PRMTs affects colitis pathogenesis in mice and inflammatory bowel disease patients and further explored the underlying mechanisms. In this study, we found that protein arginine N-methyltransferase inhibitor 1 (AMI-1 treatments increased Tregs frequency, function, and reduced colitis incidence. Adoptive transfer of AMI-1-treated Tregs could reduce the colitis incidence. Colitis was associated with increased local PRMT5 expression, which was inhibited by AMI-1 treatment. Additionally, PRMT5 knockdown T cells produced a better response to TGFβ and promoted Tregs differentiation through decreased DNA methyltransferase 1 (DNMT1 expression. PRMT5 also enhanced H3K27me3 and DNMT1 binding to Foxp3 promoter, which restricted Tregs differentiation. Furthermore, PRMT5 knockdown led to decreased Foxp3 promoter methylation during Tregs induction. PRMT5 expression had a negative relationship with Tregs in UC patients, knockdown of PRMT5 expression increased Tregs frequency and decreased TNFα, IL-6, and IL-13 levels. Our study outlines a novel regulation of PRMT5 on Tregs development and function. Strategies to decrease PRMT5 expression might have therapeutic potential to control UC.

A SAM-dependent methyltransferase cotranscribed with arsenate reductase alters resistance to peptidyl transferase center-binding antibiotics in Azospirillum brasilense Sp7.

Science.gov (United States)

Singh, Sudhir; Singh, Chhaya; Tripathi, Anil Kumar

2014-05-01

The genome of Azospirillum brasilense harbors a gene encoding S-adenosylmethionine-dependent methyltransferase, which is located downstream of an arsenate reductase gene. Both genes are cotranscribed and translationally coupled. When they were cloned and expressed individually in an arsenate-sensitive strain of Escherichia coli, arsenate reductase conferred tolerance to arsenate; however, methyltransferase failed to do so. Sequence analysis revealed that methyltransferase was more closely related to a PrmB-type N5-glutamine methyltransferase than to the arsenate detoxifying methyltransferase ArsM. Insertional inactivation of prmB gene in A. brasilense resulted in an increased sensitivity to chloramphenicol and resistance to tiamulin and clindamycin, which are known to bind at the peptidyl transferase center (PTC) in the ribosome. These observations suggested that the inability of prmB:km mutant to methylate L3 protein might alter hydrophobicity in the antibiotic-binding pocket of the PTC, which might affect the binding of chloramphenicol, clindamycin, and tiamulin differentially. This is the first report showing the role of PrmB-type N5-glutamine methyltransferases in conferring resistance to tiamulin and clindamycin in any bacterium.

Total plasma homocysteine is associated with hypertension in Type I diabetic patients

DEFF Research Database (Denmark)

Neugebauer, S; Tarnow, L; Stehouwer, C D

2002-01-01

between plasma homocysteine concentrations, methylenetetrahydrofolate reductase gene polymorphism, hypertension, diabetic microvascular and macrovascular complications associated with kidney function. METHODS: Vascular complications, hypertension, methylenetetrahydrofolate reductase genotype (RFLP...... was an independent determinant of plasma homocysteine, the methylenetetrahydrofolate reductase gene polymorphism was neither associated with diabetic vascular complications nor with hypertension. CONCLUSION/INTERPRETATION: Increased plasma homocysteine concentrations but not the T allele per se, enhance the risk...... of hypertension and of CHD in Danish Type I diabetic patients with normal renal function....

[Effects of dietary wheat gluten level on decreasing plasma homocysteine concentration in rats].

Science.gov (United States)

Liu, Yiqun; Han, Feng; Sun, Licui; Lu, Jiaxi; Sugiyama, Kimio; Huang, Zhenwu

2015-05-01

To investigate the effects of different level of casein and wheat gluten on decreasing plasma homocysteine concentration in rats. 48 rats of the Wistar were fed with different level of casein (12.5%, 25% and 50%) and wheat gluten (14.5%, 29% and 58%) diets for 14 days, and they were killed by decapitation to obtain blood and livers was subject to analysis the concentration of homocysteine, cysteine and other amino acids, as well as BHMT and CBS activities. Body weight gain in rats fed wheat gluten dietary was significantly less than casein dietary, but food intake was significantly decreased in wheat gluten group with increasing of the protein content. The plasma homocysteine concentration in rats fed wheat gluten was marketly less than casein, however plasma cysteine concentration in wheat gluten was higher than casein group. The effects of wheat gluten on plasma homocysteine concentration are mainly depends on the low contents of methionine and high cysteine content, but the low contents of lyscine and threonine are not ignored. The mainly mechanism is that the increased cysteine concentration promot enzyme activities of homocystein metabolism, and increase the consumption of homocysteine.

Homocysteine levels -before and after methionine loading- in 51 Dutch families

NARCIS (Netherlands)

Heijer, den M.; Graafsma, S.; Lee, S.Y.; Verhoef, P.

2005-01-01

Elevated levels of homocysteine are a risk factor for vascular disease, thrombosis, neural tube defects and dementia. The 677C>T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene appears to be the most important single determinant of plasma homocysteine concentration. In the

Homocysteine and C-reactive protein as useful surrogate markers for evaluating CKD risk in adults.

Science.gov (United States)

Chuang, Chung-Hsun; Lee, Yi-Yen; Sheu, Bor-Fuh; Hsiao, Cheng-Ting; Loke, Song-Seng; Chen, Jih-Chang; Li, Wen-Cheng

2013-01-01

This study aimed to evaluate the effectiveness of homocysteine and C-reactive protein (CRP) as potential markers for chronic kidney disease (CKD) in adults in Taiwan, and to identify associations between these factors and CKD, stratifying by gender. This cross-sectional study analyzed multi-center data retrospectively. Data were collected from 22,043 adult Taiwanese at Chang-Gung Memorial Hospital from 2005 to 2011. Smoking/drinking history, personal medical/medication history, pregnancy, fasting times as well as laboratory parameters, including homocysteine and CRP were measured and analyzed. Significant differences were observed between four homocysteine and CRP quartiles in eGFR and CKD. For males, only one model showed significant associations between plasma homocysteine and CKD, while in females, all three models showed significant associations with CKD. On the contrary, the gender difference in the case of CRP was opposite. Combined homocysteine and CRP were associated with CKD in males but not in females. Among Taiwanese adults, plasma homocysteine is associated with CKD in females and plasma hsCRP is associated with CKD in males. High hsCRP/high homocysteine is associated with elevated CKD risk in male. Our results suggest that homocysteine and hsCRP may be useful surrogate markers for evaluating CKD risk in adults. © 2013 S. Karger AG, Basel.

Homocysteine and C-Reactive Protein as Useful Surrogate Markers for Evaluating CKD Risk in Adults

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Chung-Hsun Chuang

2013-10-01

Full Text Available Background/Aims: This study aimed to evaluate the effectiveness of homocysteine and C-reactive protein (CRP as potential markers for chronic kidney disease (CKD in adults in Taiwan, and to identify associations between these factors and CKD, stratifying by gender. Methods: This cross-sectional study analyzed multi-center data retrospectively. Data were collected from 22,043 adult Taiwanese at Chang-Gung Memorial Hospital from 2005 to 2011. Smoking/drinking history, personal medical/medication history, pregnancy, fasting times as well as laboratory parameters, including homocysteine and CRP were measured and analyzed. Results: Significant differences were observed between four homocysteine and CRP quartiles in eGFR and CKD. For males, only one model showed significant associations between plasma homocysteine and CKD, while in females, all three models showed significant associations with CKD. On the contrary, the gender difference in the case of CRP was opposite. Combined homocysteine and CRP were associated with CKD in males but not in females. Conclusion: Among Taiwanese adults, plasma homocysteine is associated with CKD in females and plasma hsCRP is associated with CKD in males. High hsCRP/high homocysteine is associated with elevated CKD risk in male. Our results suggest that homocysteine and hsCRP may be useful surrogate markers for evaluating CKD risk in adults.

Effect of consumption of red wine, spirits, and beer on serum homocysteine.

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van der Gaag, M S; Ubbink, J B; Sillanaukee, P; Nikkari, S; Hendriks, H F

2000-04-29

Serum homocysteine increases after moderate consumption of red wine and spirits, not after moderate consumption of beer. Vitamin B6 in beer seems to prevent the alcohol-induced rise in serum homocysteine.

Synthesis, vibrational and quantum chemical investigations of hydrogen bonded complex betaine dihydrogen selenite

Science.gov (United States)

Arjunan, V.; Marchewka, Mariusz K.; Kalaivani, M.

2012-10-01

The molecular complex of betaine with selenious acid namely, betaine dihydrogen selenite (C5H13NO5Se, BDHSe) was synthesised by the reaction of betaine and SeO2 in a 1:1:1 solution of isopropanol, methanol and water. Crystals were grown from this solution by cooling to 253 K for few days. The complex was formed without accompanying proton transfer from selenious acid molecule to betaine. The complete vibrational assignments and analysis of BDHSe have been performed by FTIR, FT-Raman and far-infrared spectral studies. More support on the experimental findings was added from the quantum chemical studies performed with DFT (B3LYP) method using 6-311++G∗∗, 6-31G∗∗, cc-pVDZ and 3-21G basis sets. The structural parameters, energies, thermodynamic parameters and the NBO charges of BDHSe were determined by the DFT method. The 1H and 13C isotropic chemical shifts (δ ppm) of BDHSe with respect to TMS were also calculated using the gauge independent atomic orbital (GIAO) method and compared with the experimental data. SHG experiment was carried out using Kurtz-Perry powder technique. The efficiency of second harmonic generation for BDHSe was estimated relatively to KDP: deff = 0.97 deff (KDP).

Roles of DNA methyltransferases in Arabidopsis development ...

African Journals Online (AJOL)

Mutations that cause severe loss of DNA methylation often leads to abnormal development. In the present review, we summarized recent findings of the three major DNA methyltransferases mutants playing vital role in development of Arabidopsis thaliana. Keywords: DNA methylation, epigenetics, methyltransferase, mutant ...

Structural insight into maintenance methylation by mouse DNA methyltransferase 1 (Dnmt1)

Science.gov (United States)

Takeshita, Kohei; Suetake, Isao; Yamashita, Eiki; Suga, Michihiro; Narita, Hirotaka; Nakagawa, Atsushi; Tajima, Shoji

2011-01-01

Methylation of cytosine in DNA plays a crucial role in development through inheritable gene silencing. The DNA methyltransferase Dnmt1 is responsible for the propagation of methylation patterns to the next generation via its preferential methylation of hemimethylated CpG sites in the genome; however, how Dnmt1 maintains methylation patterns is not fully understood. Here we report the crystal structure of the large fragment (291–1620) of mouse Dnmt1 and its complexes with cofactor S-adenosyl-L-methionine and its product S-adenosyl-L-homocystein. Notably, in the absence of DNA, the N-terminal domain responsible for targeting Dnmt1 to replication foci is inserted into the DNA-binding pocket, indicating that this domain must be removed for methylation to occur. Upon binding of S-adenosyl-L-methionine, the catalytic cysteine residue undergoes a conformation transition to a catalytically competent position. For the recognition of hemimethylated DNA, Dnmt1 is expected to utilize a target recognition domain that overhangs the putative DNA-binding pocket. Taking into considerations the recent report of a shorter fragment structure of Dnmt1 that the CXXC motif positions itself in the catalytic pocket and prevents aberrant de novo methylation, we propose that maintenance methylation is a multistep process accompanied by structural changes. PMID:21518897

Plasma homocysteine and B vitamins levels in Nigerian children with nephrotic syndrome.

Science.gov (United States)

Orimadegun, Bose Etaniamhe; Orimadegun, Adebola Emmanuel; Ademola, Adebowale Dele; Agbedana, Emmanuel Oluyemi

2014-01-01

Available data on plasma homocysteine level in patients with nephrotic syndrome (NS) are controversial with increased, decreased and unchanged values reported. Therefore, plasma homocysteine and serum B vitamins in Nigerian children with NS were assessed in this study. Fasting blood samples were analysed for plasma homocysteine, serum folate and B vitamins in 42 children with NS and 42 age and sex-matched healthy controls in this case control study. Data were compared between NS and control using t test and Chi square. Relationships were tested with regression analysis with p set at 0.05. Prevalence of hyperhomocysteinaemia, low folate and cyanocobalamin in NS was 57.1%, 14.3% and 9.5% respectively. The mean homocysteine level was significantly higher in NS than control (11.3±2.6 µmol/L versus 5.5±2.3 µmol/L). Also, NS had lower folate and cyanocobalamin than control: 9.1±3.9 ng/mL versus 11.2±3.1 ng/dL and 268.5±95.7 pg/mL versus 316±117.2 pg/mL respectively. Weak but significant correlation between homocysteine and serum albumin (r = 0.347), folate (r = -0.607) and vitamin B12 (r = -0.185) were found in the NS group. Significant relationship was also found between homocysteine and vitamin B12 (ß = -0.64, 95% CI = -1.20, -0.08) after controlling for folate and vitamin B6 levels. Clinically important hyperhomocysteinaemia and low B vitamins occur in Nigerian children with nephrotic syndrome. This data suggest that potential usefulness of folate and vitamin B supplementation for reducing high homocysteine levels in nephrotic syndrome need to be further investigated.

Serum homocysteine levels in relation to clinical progression in multiple sclerosis

NARCIS (Netherlands)

Teunissen, C.E.; Killestein, J.; Kragt, J.J.; Polman, C.H.; Dijkstra, C.D.; Blom, H.J.

2008-01-01

Background: Elevated homocysteine levels are associated with various neurodegenerative diseases and have even been identified as a risk factor for some of these. Homocysteine levels may be elevated in patients with multiple sclerosis (MS) but large studies are lacking and the relation with disease

Dissecting the Catalytic Mechanism of Betaine - Homocysteine S-Methyltransferase by Use of Intrinsic Tryptophan Fluorescence and Site-Directed Mutagenesis

Czech Academy of Sciences Publication Activity Database

Castro, C.; Gratson, A. A.; Evans, J. C.; Jiráček, Jiří; Collinsová, Michaela; Ludwig, M. L.; Garrow, T. A.

2004-01-01

Roč. 43, č. 18 (2004), s. 5341-5351 ISSN 0006-2960 R&D Projects: GA AV ČR IAA4055302 Grant - others:NIH(US) GM16429; NIH(US) DK52501; Illinois Agricultural Experimental Station(US) ILLU-698-352 Institutional research plan: CEZ:AV0Z4055905 Keywords : BHMT * CBHcy * fluorescence Subject RIV: CE - Biochemistry Impact factor: 4.008, year: 2004

Homocysteine regulates fatty acid and lipid metabolism in yeast.

Science.gov (United States)

Visram, Myriam; Radulovic, Maja; Steiner, Sabine; Malanovic, Nermina; Eichmann, Thomas O; Wolinski, Heimo; Rechberger, Gerald N; Tehlivets, Oksana

2018-04-13

S -Adenosyl-l-homocysteine hydrolase (AdoHcy hydrolase; Sah1 in yeast/AHCY in mammals) degrades AdoHcy, a by-product and strong product inhibitor of S -adenosyl-l-methionine (AdoMet)-dependent methylation reactions, to adenosine and homocysteine (Hcy). This reaction is reversible, so any elevation of Hcy levels, such as in hyperhomocysteinemia (HHcy), drives the formation of AdoHcy, with detrimental consequences for cellular methylation reactions. HHcy, a pathological condition linked to cardiovascular and neurological disorders, as well as fatty liver among others, is associated with a deregulation of lipid metabolism. Here, we developed a yeast model of HHcy to identify mechanisms that dysregulate lipid metabolism. Hcy supplementation to wildtype cells up-regulated cellular fatty acid and triacylglycerol content and induced a shift in fatty acid composition, similar to changes observed in mutants lacking Sah1. Expression of the irreversible bacterial pathway for AdoHcy degradation in yeast allowed us to dissect the impact of AdoHcy accumulation on lipid metabolism from the impact of elevated Hcy. Expression of this pathway fully suppressed the growth deficit of sah1 mutants as well as the deregulation of lipid metabolism in both the sah1 mutant and Hcy-exposed wildtype, showing that AdoHcy accumulation mediates the deregulation of lipid metabolism in response to elevated Hcy in yeast. Furthermore, Hcy supplementation in yeast led to increased resistance to cerulenin, an inhibitor of fatty acid synthase, as well as to a concomitant decline of condensing enzymes involved in very long-chain fatty acid synthesis, in line with the observed shift in fatty acid content and composition. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

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 Genotype

NARCIS (Netherlands)

Caudill, M.A.; Dellschaft, N.; Solis, C.; Hinkis, S.; Ivanov, A.A.; Nash-Barboza, S.; Randall, K.E.; Jackson, B.; Solomita, G.N.; Vermeylen, F.

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

MiR-29c regulates the expression of miR-34c and miR-449a by targeting DNA methyltransferase 3a and 3b in nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Niu, Man; Gao, Dan; Wen, Qiuyuan; Wei, Pingpin; Pan, Suming; Shuai, Cijun; Ma, Huiling; Xiang, Juanjuan; Li, Zheng; Fan, Songqing; Li, Guiyuan; Peng, Shuping

2016-01-01

Nasopharyngeal carcinoma (NPC) is prevalent in South East Asia and Southern China particularly, despite the reported 5-year survival ratio is relative higher than other deadly cancers such as liver, renal, pancreas cancer, the lethality is characterized by high metastatic potential in the early stage and high recurrence rate after radiation treatment. MicroRNA-29c was found to be down-regulated in the serum as well as in the tissue of nasopharyngeal carcinoma tissue. In this study, we found accidentally that the transfection of pre-miR-29c or miR-29c mimics significantly increases the expression level of miR-34c and miR-449a but doesn’t affect that of miR-222 using real-time quantitative PCR in nasopharyngeal carcinoma cell lines. To explore the molecular mechanism of the regulatory role, the cells are treated with 5-Aza-2-deoxycytidine (5-Aza-CdR) treatment and the level of miR-34c and miR-449a but not miR-222 accumulated by the treatment. DNA methyltransferase 3a, 3b were down-regulated by the 5-Aza-CdR treatment with western blot and real-time quantitative PCR. We found that pre-miR-29c or miR-29c mimics significantly increases the expression level of miR-34c and miR-449a. We further found DNA methyltransferase 3a and 3b are the target gene of miR-29c. Restoration of miR-29c in NPC cells down-regulated DNA methyltransferase 3a, 3b, but not DNA methyltransferase T1. The regulation of miR-29c/DNMTs/miR-34c/449a is an important molecular axis of NPC development and targeting DNMTs or restoring of miR-29c might be a promising therapy strategy for the prevention of NPC

Extracellular concentration of homocysteine in human cell lines is influenced by specific inhibitors of cyst(e)ine transport.

Science.gov (United States)

Hultberg, Björn

2004-04-01

Despite the growing evidence that plasma homocysteine is a cardiovascular risk factor, the mechanism behind the vascular injuries is still unknown. Studies of the cellular uptake systems for homocysteine are scarce, but membrane transporters of cyst(e)ine seem to be involved. In the present study the cellular uptake of extracellular homocysteine in HeLa and hepatoma cell lines is investigated by using several different transport inhibitors for cellular uptake of cyst(e)ine. It is shown that systems A and Xc- are the main transport systems for homocysteine uptake in HeLa cells. It is also confirmed that the magnitude of homocysteine uptake in hepatoma cells is lower than in HeLa cells. However, in the presence of high amounts of extracellular homocysteine both cell types exhibited a high elimination of homocysteine, which was inhibited by the presence of inhibitors of systems A or Xc-. It is possible that there is normally a high turnover of homocysteine in cell cultures, which is not detected by occasional determinations of homocysteine concentrations. The complex pattern of homocysteine production, release, uptake and distribution between different cells in the body is important to examine further in order to possibly be able to modulate the elimination of homocysteine from circulation and thereby lower the risk of cardiovascular disease.

Blood homocysteine, folic acid, vitamin B12 and vitamin B6 levels in psoriasis patients

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Meltem Uslu

2017-09-01

Full Text Available Background and Design: Homocysteine, a sulfur-containing amino acid, is known to be related with autoimmunity-inflammation, cardiovascular disease and DNA methylation. In this case-control study, we aimed to determine plasma homocysteine, folic acid, vitamin B12 and vitamin B6 levels in patients with psoriasis. Materials and Methods: Smoking, alcohol and coffee consumption habits were recorded in adult patients with plaque-type psoriasis and age- and sex-matched controls. Height and weight measurements were performed and Psoriasis Area and Severity Index (PASI scores were calculated. Fasting venous blood samples were collected to determine homocysteine, folic acid, vitamin B12, vitamin B6, glucose, total cholesterol, triglyceride, high density lipoprotein (HDL, erythrocyte sedimentation rate (ESR, and C-reactive protein (CRP levels. Results: There was no significant difference between psoriasis patients (n=43 and controls (n=47 in body mass index and alcohol and coffee consumption. Smoking rate was significantly high in psoriasis patients. The median PASI score was 10.0 (8.3-12.8. Plasma homocysteine, folic acid, vitamin B12, vitamin B6, total cholesterol, triglyseride, ESR and CRP values were not significantly different between patients and the controls. HDL level was low in psoriasis patients (p=0.001. Plasma homocysteine level was higher in males than in females. There was no relationship of homocysteine levels with patient’s age, PASI scores, ESR, CRP values and lipids. Homocysteine levels were inversely related with folic acid and vitamin B12 (p=0.000, r=-0.436, p=0.047, r=-0.204, respectively. We did not find any relationship between homocysteine and vitamin B6 levels. Conclusion: There was no increase in plasma homocysteine levels in psoriasis patients we followed up. Homocysteine level increases in inflammatory disorders and this increase is accepted as a cardiovascular disease marker. Homocysteine homeostasis may be balanced in our

Association of plasma homocysteine and white matter hypodensities in a sample of stroke patients

International Nuclear Information System (INIS)

Naveed, G.

2015-01-01

Studies of homocysteine in vascular disorders have yielded conflicting data. There are also differences based on various ethnicities and cultures. In this study, we have examined the homocysteine patterns in local stroke patients, so as to ascertain the homocysteine status in a sample of local population. Homocysteine-white matter hypodensities relationship in stroke is emerging, as an important aspect in stroke pathophysiology and is thought to have prognostic and therapeutic values. Methods: We included 150 stroke patients who were diagnosed as having clinical stroke on the basis of history; physical examination and CT (Computerized Tomography) scan of brain. These patients were recruited from neurology and emergency wards of two public sector hospitals of Lahore. The presence or absence of white matter hypodensities were diagnosed after consultation with a radiologist. Blood samples were collected from the same stroke patients. Results: We found a strong association between white matter hypodensities and total homocysteine in plasma of stroke patients p<0.001. Conclusion: Homocysteine is a risk factor for white matter hypodensities in stroke patients in our study. (author)

Homocysteine status and cardiovascular risk factors in patients with psoriasis: a case-control study.

LENUS (Irish Health Repository)

Tobin, A-M

2012-02-01

BACKGROUND: Psoriasis is a hyperproliferative, cutaneous disorder with the potential to lower levels of folate. This may result in raised levels of homocysteine, an independent risk factor for the development of cardiovascular disease. OBJECTIVE: A study was conducted to compare levels of red-cell folate (RCF) and homocysteine in patients with psoriasis and in healthy controls. Levels of homocysteine were also examined in the context of other major cardiovascular risk factors. METHODS: In total, 20 patients with psoriasis and 20 controls had their RCF, homo-cysteine and other conventional cardiovascular risk factors assessed. RESULTS: Patients with psoriasis had a trend towards lower levels of RCF. Significantly raised levels of homocysteine were found in patients with psoriasis compared with controls (P = 0.007). There was no correlation between homocysteine levels, RCF levels or disease activity as measured by the Psoriasis Area and Severity Index. Patients with psoriasis had higher body mass index (P < 0.004) and higher systolic blood pressure (P < 0.001) than controls. This may contribute to the excess cardiovascular mortality observed in patients with psoriasis.

[Prognosis significance of blood homocysteine after myocardial infarction].

Science.gov (United States)

Reis, R P; Azinheira, J; Reis, H P; Bordalo e Sá, A; Tavares, J; Adão, M; Santos, A L; Pina, J E; Correia, J M; Luís, A S

2000-05-01

Homocysteinemia is an independent risk factor of coronary artery disease and of myocardial infarction. In the present study we intend to relate fasting homocystein levels to prognosis after a myocardial infarction. From 1990 to 1992, we studied fasting homocysteinemia levels on a group of 112 patients aged under 56 years that had suffered a myocardial infarction between 3 and 12 months before. We obtained, the patients names, addresses, phone numbers and physicians' name. Seven years later (on average) we collected data regarding the patients evolution, consulting medical records, their physicians or by personal contact. We evaluated complications, namely mortality, vascular morbidity, such as unstable angina, re-infarction, stroke, and the need for invasive procedures (catheterism, PTCA, CABG). According to previous studies of the group, we used a cut-point of 10.10 mumol/L to define patients with normal or pathological levels of homocysteinemia. We excluded all patients that took vitamin B supplements, co-factors of HC metabolism, during this follow-up. We were able to obtain data on 110 patients. Patients with normal HC levels (n = 62) presented less global complications (26 versus 72%, p homocystein levels (n = 48), those with higher homocystein levels presented a higher degree of complications. In this population with myocardial infarction under 56 years of age, a high homocysteinemia level is an important prognostic factor. This study suggests that we can improve the prognosis and decrease the complications after myocardial infarction by lowering elevated homocystein levels.

Ameliorative effects of betaine and ascorbic acid administration to ...

African Journals Online (AJOL)

SAM

2014-06-04

Jun 4, 2014 ... The production of broiler chickens under heat stress conditions results ... other poultry, including pigeons, ducks, guinea fowls and turkeys (Abdullahi ...... betaine on energy utilization in growing pigs - a review. Ann. Anim. Sci.

Homocyst(e)ine and cardiovascular disease: a critical review of the epidemiologic evidence.

Science.gov (United States)

Eikelboom, J W; Lonn, E; Genest, J; Hankey, G; Yusuf, S

1999-09-07

To review epidemiologic studies on the association between homocyst(e)ine level and risk for cardiovascular disease and the potential benefits of homocysteine-decreasing therapies. Computerized and manual searches of the literature on total homocysteine levels and cardiovascular disease. Prospective studies and major retrospective epidemiologic studies evaluating the association between homocyst(e)ine levels and cardiovascular disease and the association between blood levels or dietary intake of folate, vitamin B6, and vitamin B12 and cardiovascular disease. Relevant data on patient population, plasma homocyst(e)ine levels, duration of follow-up, and main results were extracted from studies that met the inclusion criteria. The designs and results of studies included in this review are summarized. A formal meta-analysis was not performed because the studies were heterogeneous in method and design. Results of epidemiologic studies suggest that moderately elevated plasma or serum homocyst(e)ine levels are prevalent in the general population and are associated with an increased risk for cardiovascular disease, independent of classic cardiovascular risk factors. Simple, inexpensive, nontoxic therapy with folic acid, vitamin B6, and vitamin B12 reduces plasma homocyst(e)ine levels. Although the association between homocyst(e)ine levels and cardiovascular disease is generally strong and biologically plausible, the data from the prospective studies are less consistent. In addition, epidemiologic observations of an association between hyperhomocyst(e)inemia and cardiovascular risk do not prove the existence of a causal relation. Therefore, the effectiveness of folate, vitamin B6, and vitamin B12 in reducing cardiovascular morbidity and mortality requires rigorous testing in randomized clinical trials. Several such trials are under way; their results may greatly affect cardiovascular morbidity and mortality, given the simplicity and low cost of vitamin therapy.

Trimethylamine N-oxide stabilizes proteins via a distinct mechanism compared with betaine and glycine

Science.gov (United States)

Liao, Yi-Ting; Manson, Anthony C.; DeLyser, Michael R.; Noid, William G.; Cremer, Paul S.

2017-01-01

We report experimental and computational studies investigating the effects of three osmolytes, trimethylamine N-oxide (TMAO), betaine, and glycine, on the hydrophobic collapse of an elastin-like polypeptide (ELP). All three osmolytes stabilize collapsed conformations of the ELP and reduce the lower critical solution temperature (LSCT) linearly with osmolyte concentration. As expected from conventional preferential solvation arguments, betaine and glycine both increase the surface tension at the air–water interface. TMAO, however, reduces the surface tension. Atomically detailed molecular dynamics (MD) simulations suggest that TMAO also slightly accumulates at the polymer–water interface, whereas glycine and betaine are strongly depleted. To investigate alternative mechanisms for osmolyte effects, we performed FTIR experiments that characterized the impact of each cosolvent on the bulk water structure. These experiments showed that TMAO red-shifts the OH stretch of the IR spectrum via a mechanism that was very sensitive to the protonation state of the NO moiety. Glycine also caused a red shift in the OH stretch region, whereas betaine minimally impacted this region. Thus, the effects of osmolytes on the OH spectrum appear uncorrelated with their effects upon hydrophobic collapse. Similarly, MD simulations suggested that TMAO disrupts the water structure to the least extent, whereas glycine exerts the greatest influence on the water structure. These results suggest that TMAO stabilizes collapsed conformations via a mechanism that is distinct from glycine and betaine. In particular, we propose that TMAO stabilizes proteins by acting as a surfactant for the heterogeneous surfaces of folded proteins. PMID:28228526

The histone lysine methyltransferase KMT2D sustains a gene expression program that represses B cell lymphoma development.

Science.gov (United States)

Ortega-Molina, Ana; Boss, Isaac W; Canela, Andres; Pan, Heng; Jiang, Yanwen; Zhao, Chunying; Jiang, Man; Hu, Deqing; Agirre, Xabier; Niesvizky, Itamar; Lee, Ji-Eun; Chen, Hua-Tang; Ennishi, Daisuke; Scott, David W; Mottok, Anja; Hother, Christoffer; Liu, Shichong; Cao, Xing-Jun; Tam, Wayne; Shaknovich, Rita; Garcia, Benjamin A; Gascoyne, Randy D; Ge, Kai; Shilatifard, Ali; Elemento, Olivier; Nussenzweig, Andre; Melnick, Ari M; Wendel, Hans-Guido

2015-10-01

The gene encoding the lysine-specific histone methyltransferase KMT2D has emerged as one of the most frequently mutated genes in follicular lymphoma and diffuse large B cell lymphoma; however, the biological consequences of KMT2D mutations on lymphoma development are not known. Here we show that KMT2D functions as a bona fide tumor suppressor and that its genetic ablation in B cells promotes lymphoma development in mice. KMT2D deficiency also delays germinal center involution and impedes B cell differentiation and class switch recombination. Integrative genomic analyses indicate that KMT2D affects methylation of lysine 4 on histone H3 (H3K4) and expression of a set of genes, including those in the CD40, JAK-STAT, Toll-like receptor and B cell receptor signaling pathways. Notably, other KMT2D target genes include frequently mutated tumor suppressor genes such as TNFAIP3, SOCS3 and TNFRSF14. Therefore, KMT2D mutations may promote malignant outgrowth by perturbing the expression of tumor suppressor genes that control B cell-activating pathways.

Elevated homocysteine by levodopa is detrimental to neurogenesis in parkinsonian model.

Directory of Open Access Journals (Sweden)

Jin Young Shin

Full Text Available BACKGROUND: Modulation of neurogenesis that acts as an endogenous repair mechanism would have a significant impact on future therapeutic strategies for Parkinson's disease (PD. Several studies demonstrated dopaminergic modulation of neurogenesis in the subventricular zone (SVZ of the adult brain. Levodopa, the gold standard therapy for PD, causes an increase in homocysteine levels that induces neuronal death via N-methyl-D-aspartate (NMDA receptor. The present study investigated whether elevated homocysteine by levodopa treatment in a parkinsonian model would modulate neurogenesis via NMDA receptor signal cascade and compared the effect of levodopa and pramipexol (PPX on neurogenic activity. METHODOLOGY/PRINCIPAL FINDINGS: Neurogenesis was assessed in vitro using neural progenitor cells (NPCs isolated from the SVZ and in vivo with the BrdU-injected animal model of PD using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Modulation of homocysteine levels was evaluated using co-cultures of NPCs and astrocytes and PD animals. Immunochemical and Western blot analyses were used to measure neurogenesis and determine the cell death signaling. Levodopa treatment increased release of homocysteine on astrocytes culture media as well as in plasma and brain of PD animals. Increased homocysteine by levodopa led to increased apoptosis of NPCs through the NMDA receptor-dependent the extracellular signal-regulated kinase (ERK signaling pathways. The administration of a NMDA antagonist significantly attenuated apoptotic cell death in levodopa-treated NPCs and markedly increased the number of BrdU-positive cells in the SVZ of levodopa-treated PD animals. Comparative analysis revealed that PPX treatment significantly increased the number of NPCs and BrdU-positive cells in the SVZ of PD animals compared to levodopa treatment. Our present study demonstrated that increased homocysteine by levodopa has a detrimental effect on neurogenesis through NMDA receptor

Targeting MLL1 H3K4 methyltransferase activity in mixed-lineage leukemia.

Science.gov (United States)

Cao, Fang; Townsend, Elizabeth C; Karatas, Hacer; Xu, Jing; Li, Li; Lee, Shirley; Liu, Liu; Chen, Yong; Ouillette, Peter; Zhu, Jidong; Hess, Jay L; Atadja, Peter; Lei, Ming; Qin, Zhaohui S; Malek, Sami; Wang, Shaomeng; Dou, Yali

2014-01-23

Here we report a comprehensive characterization of our recently developed inhibitor MM-401 that targets the MLL1 H3K4 methyltransferase activity. MM-401 is able to specifically inhibit MLL1 activity by blocking MLL1-WDR5 interaction and thus the complex assembly. This targeting strategy does not affect other mixed-lineage leukemia (MLL) family histone methyltransferases (HMTs), revealing a unique regulatory feature for the MLL1 complex. Using MM-401 and its enantiomer control MM-NC-401, we show that inhibiting MLL1 methyltransferase activity specifically blocks proliferation of MLL cells by inducing cell-cycle arrest, apoptosis, and myeloid differentiation without general toxicity to normal bone marrow cells or non-MLL cells. More importantly, transcriptome analyses show that MM-401 induces changes in gene expression similar to those of MLL1 deletion, supporting a predominant role of MLL1 activity in regulating MLL1-dependent leukemia transcription program. We envision broad applications for MM-401 in basic and translational research. Copyright © 2014 Elsevier Inc. All rights reserved.

Unfiltered coffee increases plasma homocysteine concentrations in healthy volunteers: a randomized trial

NARCIS (Netherlands)

Grubben, M.J.; Boers, G.H.; Blom, H.J.; Broekhuizen, R.; Jong, de R.; Rijt, van L.; Katan, M.B.

2000-01-01

Background: An elevated plasma homocysteine concentration is a putative risk factor for cardiovascular disease. Observational studies have reported an association between coffee consumption and plasma homocysteine concentrations. Objective: We studied the effect of coffee consumption on plasma

GNMT Expression Increases Hepatic Folate Contents and Folate-Dependent Methionine Synthase-Mediated Homocysteine Remethylation

OpenAIRE

Wang, Yi-Cheng; Chen, Yi-Ming; Lin, Yan-Jun; Liu, Shih-Ping; Chiang, En-Pei Isabel

2011-01-01

Glycine N-methyltransferase (GNMT) is a major hepatic enzyme that converts S-adenosylmethionine to S-adenosylhomocysteine while generating sarcosine from glycine, hence it can regulate mediating methyl group availability in mammalian cells. GNMT is also a major hepatic folate binding protein that binds to, and, subsequently, may be inhibited by 5-methyltetrafolate. GNMT is commonly diminished in human hepatoma; yet its role in cellular folate metabolism, in tumorigenesis and antifolate therap...

Distinct Difference in Absorption Pattern in Pigs of Betaine Provided as a Supplement or Present Naturally in Cereal Dietary Fiber

DEFF Research Database (Denmark)

Hedemann, Mette Skou; Theil, Peter Kappel; Lærke, Helle Nygaard

2015-01-01

high-fiber breads differing in amount and source of dietary fiber (two experiments, n = 6 pigs each). Plasma betaine peaked after 30 min when betaine was fed as a supplement, whereas it peaked after 120–180 min when high-fiber breads were fed. Plasma betaine showed no diet × time interaction after...... feeding with high-fiber breads, indicating that the absorption kinetic did not differ between fiber sources. The net absorption of choline was not affected by the experimental diets. In conclusion, betaine in cereal sources has to be liberated from the matrix prior to absorption, causing delayed...

Proofreading in vivo: Editing of homocysteine by methionyl-tRNA synthetase in Escherichia coli

International Nuclear Information System (INIS)

Jakubowski, H.

1990-01-01

Previous in vitro studies have established a pre-transfer proofreading mechanism for editing of homocysteine by bacterial methionyl-, isoleucyl-, and valyl-tRNA synthetases. The unusual feature of the editing is the formation of a distinct compound, homocysteine thiolactone. Now, two-dimensional TLC analysis of 35S-labeled amino acids extracted from cultures of the bacterium Escherichia coli reveals that the thiolactone is also synthesized in vivo. In E. coli, the thiolactone is made from homocysteine in a reaction catalyzed by methionyl-tRNA synthetase. One molecule of homocysteine is edited as thiolactone per 109 molecules of methionine incorporated into protein in vivo. These results not only directly demonstrate that the adenylate proofreading pathway for rejection of misactivated homocysteine operates in vivo in E. coli but, in general, establish the importance of error-editing mechanisms in living cells

Plasma homocyst(e)ine concentrations in pregnant and nonpregnant women with controlled folate intake.

Science.gov (United States)

Bonnette, R E; Caudill, M A; Boddie, A M; Hutson, A D; Kauwell, G P; Bailey, L B

1998-08-01

To assess the effects of folate intake and pregnancy on plasma total homocyst(e)ine concentrations in women during the second trimester of pregnancy compared with young, healthy nonpregnant women. The diet provided either 450 or 850 microg of folate per day. These levels are approximately the current (400 microg/day) and previous (800 microg/day) Recommended Dietary Allowances for folate in pregnant women. Folate was provided as both food folate (120 microg/day) and supplemental folic acid (either 330 or 730 microg/day) for a period of 12 weeks. Plasma homocyst(e)ine (sum of free and protein-bound homocysteine), serum folate, and erythrocyte folate concentrations were determined weekly. Homocyst(e)ine concentrations were lower in pregnant women during the second trimester of normal pregnancy than in nonpregnant controls, independent of dietary folate intake. The overall mean (+/- standard deviation) homocyst(e)ine concentration of the pregnant subjects (5.4 +/- 1.4 micromol/L) was significantly lower than that observed in the nonpregnant control group (8.7 +/- 1.7 micromol/L) (P ine concentrations remained constant throughout the 12 weeks of the investigation. The folate intakes in this investigation were adequate to maintain constant homocyst(e)ine concentrations in pregnant and nonpregnant women. The lower homocyst(e)ine concentrations observed in pregnant subjects compared with nonpregnant controls may be a physiologic response to pregnancy.

Homocysteine as a Diagnostic and Etiopathogenic Factor in Children with Autism Spectrum Disorder.

Science.gov (United States)

Józefczuk, Jan; Kasprzycka, Wiktoria; Czarnecki, Rafał; Graczyk, Alfreda; Józefczuk, Paweł; Magda, Krzysztof; Lampart, Urszula

2017-08-01

Substantial characteristics of autism are cognitive and psychophysical disorders. Etiopathogenetic factors are thought to be responsible for development of autism in children with genetic predisposition as well as have their effect on the severity of the disorders. The main problem of early identification of patients affected by autism spectrum disorder is that there are no clear diagnostic criteria. The aim of our study was assessment of hair magnesium and serum homocysteine concentrations in children with autism. The presented work is a continuation of previous study in which we investigated the influence of disturbances in magnesium and homocysteine levels in children with autism, performed on a new, larger group of patients. One hundred and forty children had hair magnesium levels analyzed, as well as blood serum levels of homocysteine and magnesium. Hair magnesium analysis was performed using a flame atomic absorption spectrometer, blood serum homocysteine determination was performed using a radioimmunological method, and blood serum magnesium level was determined using a biochemical method. Our research showed normal magnesium blood levels and significantly high homocysteine levels and very low hair magnesium levels. Low concentration of hair magnesium progresses with age. Our hypothesis is that magnesium deficiency, as a relevant epigenetic factor, might be decreasing methylation of homocysteine, therefore decreasing genome transcription and lowering the synaptic plasticity. We suggest that analysis of hair magnesium and serum homocysteine levels might be useful in identification of children with autism spectrum disorder, as well as control of its treatment. Obtained results and performed analysis might therefore justify supplementation of magnesium among children with autism.

Microstructural White Matter Tissue Characteristics Are Modulated by Homocysteine: A Diffusion Tensor Imaging Study

OpenAIRE

Hsu, Jung-Lung; Chen, Wei-Hung; Bai, Chyi-Huey; Leu, Jyu-Gang; Hsu, Chien-Yeh; Viergever, Max A.; Leemans, Alexander

2015-01-01

Homocysteine level can lead to adverse effects on the brain white matter through endothelial dysfunction, microstructural inflammation, and neurotoxin effects. Despite previously observed associations between elevated homocysteine and macroscopic structural brain changes, it is still unknown whether microstructural associations of homocysteine on brain tissue properties can be observed in healthy subjects with routine MRI. To this end, we investigated potential relationships between homocyste...

Rauvolfia serpentina N-methyltransferases involved in ajmaline and Nβ -methylajmaline biosynthesis belong to a gene family derived from γ-tocopherol C-methyltransferase.

Science.gov (United States)

Cázares-Flores, Paulo; Levac, Dylan; De Luca, Vincenzo

2016-08-01

Ajmaline biosynthesis in Rauvolfia serpentina has been one of the most studied monoterpenoid indole alkaloid (MIA) pathways within the plant family Apocynaceae. Detailed molecular and biochemical information on most of the steps involved in the pathway has been generated over the last 30 years. Here we report the identification, molecular cloning and functional expression in Escherichia coli of two R. serpentinacDNAs that are part of a recently discovered γ-tocopherol-like N-methyltransferase (γ-TLMT) family and are involved in indole and side-chain N-methylation of ajmaline. Recombinant proteins showed remarkable substrate specificity for molecules with an ajmalan-type backbone and strict regiospecific N-methylation. Furthermore, N-methyltransferase gene transcripts and enzyme activity were enriched in R. serpentina roots which correlated with accumulation of ajmaline alkaloid. This study elucidates the final step in the ajmaline biosynthetic pathway and describes the enzyme responsible for the formation of Nβ -methylajmaline, an unusual charged MIA found in R. serpentina. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Homocysteine and coronary heart disease : the role of polymorphic genes and hemostasis

NARCIS (Netherlands)

Klerk, M.

2002-01-01

Background Homocysteine is a sulfur-containing amino acid formed during catabolism of the essential amino acid methionine. Defects in genes encoding enzymes or sub-optimal intake of B-vitamins (e.g. folate) involved in homocysteine