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Bhatt M, Lazzarin E, Alberto-Silva AS, Domingo G, Zerlotti R, Gradisch R, Bazzone A, Sitte HH, Stockner T, Bossi E. Unveiling the crucial role of betaine: modulation of GABA homeostasis via SLC6A1 transporter (GAT1). Cell Mol Life Sci 2024; 81:269. [PMID: 38884791 DOI: 10.1007/s00018-024-05309-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 06/18/2024]
Abstract
Betaine is an endogenous osmolyte that exhibits therapeutic potential by mitigating various neurological disorders. However, the underlying cellular and molecular mechanisms responsible for its neuroprotective effects remain puzzling.In this study, we describe a possible mechanism behind the positive impact of betaine in preserving neurons from excitotoxicity. Here we demonstrate that betaine at low concentration modulates the GABA uptake by GAT1 (slc6a1), the predominant GABA transporter in the central nervous system. This modulation occurs through the temporal inhibition of the transporter, wherein prolonged occupancy by betaine impedes the swift transition of the transporter to the inward conformation. Importantly, the modulatory effect of betaine on GAT1 is reversible, as the blocking of GAT1 disappears with increased extracellular GABA. Using electrophysiology, mass spectroscopy, radiolabelled cellular assay, and molecular dynamics simulation we demonstrate that betaine has a dual role in GAT1: at mM concentration acts as a slow substrate, and at µM as a temporal blocker of GABA, when it is below its K0.5. Given this unique modulatory characteristic and lack of any harmful side effects, betaine emerges as a promising neuromodulator of the inhibitory pathways improving GABA homeostasis via GAT1, thereby conferring neuroprotection against excitotoxicity.
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Affiliation(s)
- Manan Bhatt
- Department of Biotechnology and Life Science, Laboratory of Cellular and Molecular Physiology, University of Insubria, Via J. H. Dunant 3, 21100, Varese, Italy
| | - Erika Lazzarin
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Ana Sofia Alberto-Silva
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Guido Domingo
- Department of Biotechnology and Life Science, Laboratory of Cellular and Molecular Physiology, University of Insubria, Via J. H. Dunant 3, 21100, Varese, Italy
| | - Rocco Zerlotti
- Nanion Technologies GmbH, Ganghoferstr. 70a, 80339, Munich, Germany
| | - Ralph Gradisch
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Andre Bazzone
- Nanion Technologies GmbH, Ganghoferstr. 70a, 80339, Munich, Germany
| | - Harald H Sitte
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
- Hourani Center for Applied Scientific Research, Al-Ahliyya Amman University, Amman, 19328, Jordan
- Center for Addiction Research and Science, Medical University of Vienna, 1090, Vienna, Austria
| | - Thomas Stockner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - Elena Bossi
- Department of Biotechnology and Life Science, Laboratory of Cellular and Molecular Physiology, University of Insubria, Via J. H. Dunant 3, 21100, Varese, Italy.
- Centre for Neuroscience, University of Insubria, 21100, Varese, Italy.
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Efficacy and pharmacokinetics of betaine in CBS and cblC deficiencies: a cross-over randomized controlled trial. Orphanet J Rare Dis 2022; 17:417. [PMID: 36376887 PMCID: PMC9664596 DOI: 10.1186/s13023-022-02567-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 10/30/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Betaine is an "alternate" methyl donor for homocysteine remethylation catalyzed by betaine homocysteine methyltransferase (BHMT), an enzyme mainly expressed in the liver and kidney. Betaine has been used for more than 30 years in pyridoxine non-responsive cystathionine beta-synthase (pnrCBS) and cobalamin C (cblC) deficiencies to lower the hyperhomocysteinemia, although little is known about the optimal therapeutic dosage and its pharmacokinetic in these patients. AIMS We compared 2 betaine doses (100 mg/kg/day vs. 250 mg/kg/day) in children affected by pnrCBS or cblC deficiencies. We also measured the pharmacokinetics parameters after a single dose of betaine (100 or 250 mg/kg) in these patients. METHODS We conducted a prospective, randomized, crossover clinical trial with blinded evaluation. The primary outcome was the equivalence of total plasma homocysteine (tHcy) concentrations upon one-month oral treatment with betaine at 100 versus 250 mg/kg/day. RESULTS Eleven patients completed the study (5 pnrCBS and 6 cblC). tHcy concentrations were equivalent after a one-month treatment period for the two betaine dosages. Multivariate analysis showed a significant effect of betaine dose on methionine (Met) (p = 0.01) and S-adenosylmethionine (SAM) concentrations (p = 0.006). CONCLUSIONS Our analysis shows that there is no overt benefit to increasing betaine dosage higher than 100 mg/kg/day to lower tHcy concentrations in pnrCBS and cblC deficiencies. However, increasing betaine up to 250 mg/kg/d could benefit cblC patients through the increase of methionine and SAM concentrations, as low Met and SAM concentrations are involved in the pathophysiology of this disease. In contrast, in pnrCBS deficiency, betaine doses higher than 100 mg/kg/day could be harmful to these patients with pre-existing hypermethioninemia. TRIAL REGISTRATION Clinical Trials, NCT02404337. Registered 23 May 2015-prospectively registered, https://clinicaltrials.gov .
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Ashtary-Larky D, Bagheri R, Ghanavati M, Asbaghi O, Tinsley GM, Mombaini D, Kooti W, Kashkooli S, Wong A. Effects of betaine supplementation on cardiovascular markers: A systematic review and Meta-analysis. Crit Rev Food Sci Nutr 2021; 62:6516-6533. [PMID: 33764214 DOI: 10.1080/10408398.2021.1902938] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Controversy regarding the effects of betaine supplementation on cardiovascular markers has persisted for decades. This systematic review and meta-analysis compared the effects of betaine supplementation on cardiovascular disease (CVD) markers. Studies examining betaine supplementation on CVD markers published up to February 2021 were identified through PubMed, the Cochrane Library, Web of Science, Embase, and SCOPUS. Betaine supplementation had a significant effect on concentrations of betaine (MD: 82.14 μmol/L, 95% CI: 67.09 to 97.20), total cholesterol (TC) (MD: 14.12 mg/dl, 95% CI%: 9.23 to 19.02), low-density lipoprotein (LDL) (MD: 10.26 mg/dl, 95% CI: 6.14 to 14.38)], homocysteine (WMD: -1.30 micromol/L, 95% CI: -1.61 to -0.98), dimethylglycine (DMG) (MD: 21.33 micromol/L, 95% CI: 13.87 to 28.80), and methionine (MD: 2.06 micromol/L, 95% CI: 0.23 to 3.88). Moreover, our analysis indicated that betaine supplementation did not affect serum concentrations of triglyceride (TG), high-density lipoprotein (HDL), fasting blood glucose (FBG), C-reactive protein (CRP), liver enzymes [alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT)], and blood pressure. Our subgroup analysis suggested that a maximum dose of 4 g/d might have homocysteine-lowering effects without any adverse effect on lipid profiles reported with doses of ≥4 g/d. In conclusion, the present systematic review and meta-analysis supports the advantage of a lower dose of betaine supplementation (<4 g/d) on homocysteine concentrations without the lipid-augmenting effect observed with a higher dosage.
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Affiliation(s)
- Damoon Ashtary-Larky
- Nutrition and Metabolic Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Reza Bagheri
- Department of Exercise Physiology, University of Isfahan, Isfahan, Iran
| | - Matin Ghanavati
- Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology, Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Omid Asbaghi
- Student Research Committee, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Grant M Tinsley
- Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, Texas, USA
| | - Delsa Mombaini
- Nutrition and Metabolic Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Wesam Kooti
- Lung Diseases & Allergy Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
| | - Sara Kashkooli
- Student Research Committee, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Alexei Wong
- Department of Health and Human Performance, Marymount University, Arlington, Texas, USA
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Ali SAEM. Nutritional Deficiencies and Hyperhomocysteinemia. NUTRITIONAL MANAGEMENT AND METABOLIC ASPECTS OF HYPERHOMOCYSTEINEMIA 2021:259-267. [DOI: 10.1007/978-3-030-57839-8_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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Betaine in the Brain: Characterization of Betaine Uptake, its Influence on Other Osmolytes and its Potential Role in Neuroprotection from Osmotic Stress. Neurochem Res 2017; 42:3490-3503. [PMID: 28918494 DOI: 10.1007/s11064-017-2397-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/15/2017] [Accepted: 08/29/2017] [Indexed: 01/17/2023]
Abstract
Betaine (N-trimethylglycine), a common osmolyte, has received attention because of the number of clinical reports associating betaine supplementation with improved cognition, neuroprotection and exercise physiology. However, tissue analyses report little accumulation of betaine in brain tissue despite the presence of betaine/GABA transporters (BGT1) at the blood brain barrier and in nervous tissue, calling into question whether betaine influences neuronal function directly or indirectly. Therefore, the focus of this study was to determine what capacity nervous tissue has to accumulate betaine, specifically in the hippocampus, a region of the brain associated with learning and memory and one that is particularly susceptible to damage (e.g., seizure activity). Here we report that hippocampal slices actively accumulate betaine in a time, dose and osmolality dependent manner, resulting in peak intracellular concentrations four times extracellular concentrations within 8 h. Our data also indicate that betaine uptake differentially influences the accumulation of other osmolytes. Under isosmotic conditions, betaine uptake minimally impacted some osmolytes (e.g., glycerylphosphorylcholine and glutamate) while significantly reducing others (taurine, creatine, and myo-inositol). Under osmotic stress (hyperosmotic) conditions, we observed dramatic changes in osmolytes like glycine and glutamine-key players in inhibitory neurotransmission-and little change in osmolytes such as taurine, creatine and myo-inositol when betaine was available. These data suggest that betaine may influence pathways of inhibitory neurotransmitter production/recycling in addition to serving as an osmolyte and metabolic intermediate. In sum, our data provide detailed characterization of betaine uptake in the hippocampus that implicates betaine in the modulation of hippocampal neurophysiology and neuroprotection.
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Morris AAM, Kožich V, Santra S, Andria G, Ben-Omran TIM, Chakrapani AB, Crushell E, Henderson MJ, Hochuli M, Huemer M, Janssen MCH, Maillot F, Mayne PD, McNulty J, Morrison TM, Ogier H, O'Sullivan S, Pavlíková M, de Almeida IT, Terry A, Yap S, Blom HJ, Chapman KA. Guidelines for the diagnosis and management of cystathionine beta-synthase deficiency. J Inherit Metab Dis 2017; 40:49-74. [PMID: 27778219 PMCID: PMC5203861 DOI: 10.1007/s10545-016-9979-0] [Citation(s) in RCA: 187] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/11/2016] [Accepted: 09/12/2016] [Indexed: 12/17/2022]
Abstract
Cystathionine beta-synthase (CBS) deficiency is a rare inherited disorder in the methionine catabolic pathway, in which the impaired synthesis of cystathionine leads to accumulation of homocysteine. Patients can present to many different specialists and diagnosis is often delayed. Severely affected patients usually present in childhood with ectopia lentis, learning difficulties and skeletal abnormalities. These patients generally require treatment with a low-methionine diet and/or betaine. In contrast, mildly affected patients are likely to present as adults with thromboembolism and to respond to treatment with pyridoxine. In this article, we present recommendations for the diagnosis and management of CBS deficiency, based on a systematic review of the literature. Unfortunately, the quality of the evidence is poor, as it often is for rare diseases. We strongly recommend measuring the plasma total homocysteine concentrations in any patient whose clinical features suggest the diagnosis. Our recommendations may help to standardise testing for pyridoxine responsiveness. Current evidence suggests that patients are unlikely to develop complications if the plasma total homocysteine concentration is maintained below 120 μmol/L. Nevertheless, we recommend keeping the concentration below 100 μmol/L because levels fluctuate and the complications associated with high levels are so serious.
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Affiliation(s)
- Andrew A M Morris
- Institute of Human Development, University of Manchester, Manchester, UK.
- Willink Unit, Manchester Centre for Genomic Medicine, Central Manchester University Hospitals, St Mary's Hospital, Oxford Road, Manchester, M13 9WL, UK.
| | - Viktor Kožich
- Institute of Inherited Metabolic Disorders, Charles University in Prague-First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - Saikat Santra
- Clinical IMD, Birmingham Children's Hospital, Birmingham, UK
| | - Generoso Andria
- Department of translational medicine, Federico II University, Naples, Italy
| | | | | | - Ellen Crushell
- National Centre for Inherited Metabolic Disorders, Temple Street Children's University Hospital, Dublin, Ireland
| | - Mick J Henderson
- Willink Unit, Manchester Centre for Genomic Medicine, Central Manchester University Hospitals, St Mary's Hospital, Oxford Road, Manchester, M13 9WL, UK
- Biochemical Genetics, St James' University Hospital, Leeds, UK
| | - Michel Hochuli
- Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zürich, Zurich, Switzerland
| | - Martina Huemer
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, Zurich, Switzerland
- Rare Disease Initiative Zürich, University of Zürich, Zurich, Switzerland
- Dept. of Paediatrics, Landeskrankenhaus Bregenz, Bregenz, Austria
| | - Miriam C H Janssen
- Department of Internal medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Philip D Mayne
- Newborn Bloodspot Screening Laboratory, Temple Street Children's University Hospital, Dublin, Ireland
| | - Jenny McNulty
- National Centre for Inherited Metabolic Disorders, Temple Street Children's University Hospital, Dublin, Ireland
| | | | - Helene Ogier
- Service de Neurologie Pédiatrique et des Maladies Métaboliques, Hôpital Robert Debré, Paris, France
| | | | - Markéta Pavlíková
- Institute of Inherited Metabolic Disorders, Charles University in Prague-First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | | | - Allyson Terry
- Institute of Human Development, University of Manchester, Manchester, UK
- Dietetic Department, Alder Hey Hospital, Liverpool, UK
| | - Sufin Yap
- Dept of Inherited Metabolic Diseases, Sheffield Children's Hospital, Sheffield, UK
| | - Henk J Blom
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, University Medical Centre Freiburg, Freiburg im Breisgau, Germany
| | - Kimberly A Chapman
- Division of Genetic and Metabolism, Children's National Health System, Washington, DC, USA
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Adam S, Almeida MF, Carbasius Weber E, Champion H, Chan H, Daly A, Dixon M, Dokoupil K, Egli D, Evans S, Eyskens F, Faria A, Ferguson C, Hallam P, Heddrich-Ellerbrok M, Jacobs J, Jankowski C, Lachmann R, Lilje R, Link R, Lowry S, Luyten K, MacDonald A, Maritz C, Martins E, Meyer U, Müller E, Murphy E, Robertson LV, Rocha JC, Saruggia I, Schick P, Stafford J, Stoelen L, Terry A, Thom R, van den Hurk T, van Rijn M, van Teefelen-Heithoff A, Webster D, White FJ, Wildgoose J, Zweers H. Dietary practices in pyridoxine non-responsive homocystinuria: a European survey. Mol Genet Metab 2013; 110:454-9. [PMID: 24206934 DOI: 10.1016/j.ymgme.2013.10.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 10/05/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND Within Europe, the management of pyridoxine (B6) non-responsive homocystinuria (HCU) may vary but there is limited knowledge about treatment practice. AIM A comparison of dietetic management practices of patients with B6 non-responsive HCU in European centres. METHODS A cross-sectional audit by questionnaire was completed by 29 inherited metabolic disorder (IMD) centres: (14 UK, 5 Germany, 3 Netherlands, 2 Switzerland, 2 Portugal, 1 France, 1 Norway, 1 Belgium). RESULTS 181 patients (73% >16 years of age) with HCU were identified. The majority (66%; n=119) were on dietary treatment (1-10 years, 90%; 11-16 years, 82%; and >16 years, 58%) with or without betaine and 34% (n=62) were on betaine alone. The median natural protein intake (g/day) on diet only was, by age: 1-10 years, 12 g; 11-16 years, 11 g; and >16 years, 45 g. With diet and betaine, median natural protein intake (g/day) by age was: 1-10 years, 13 g; 11-16 years, 20 g; and >16 years, 38 g. Fifty-two percent (n=15) of centres allocated natural protein by calculating methionine rather than a protein exchange system. A methionine-free l-amino acid supplement was prescribed for 86% of diet treated patients. Fifty-two percent of centres recommended cystine supplements for low plasma concentrations. Target treatment concentrations for homocystine/homocysteine (free/total) and frequency of biochemical monitoring varied. CONCLUSION In B6 non-responsive HCU the prescription of dietary restriction by IMD centres declined with age, potentially associated with poor adherence in older patients. Inconsistencies in biochemical monitoring and treatment indicate the need for international consensus guidelines.
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Affiliation(s)
- S Adam
- Glasgow Royal Infirmary, Royal Hospital for Sick Children, UK
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McRae MP. Betaine supplementation decreases plasma homocysteine in healthy adult participants: a meta-analysis. J Chiropr Med 2013; 12:20-5. [PMID: 23997720 DOI: 10.1016/j.jcm.2012.11.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 11/17/2012] [Accepted: 11/30/2012] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE Betaine supplementation has been shown to be an effective agent for decreasing plasma homocysteine in healthy adults. Studies in healthy volunteers show that 6 g/d of betaine lowers plasma homocysteine concentrations by 5% to 20%. The purpose of this study was to perform a meta-analysis of randomized placebo-controlled trials that used daily betaine supplementation to identify the range in betaine's effects on lowering homocysteine. METHODS Five randomized controlled trials published between 2002 and 2010 were identified using MEDLINE and a manual search. All 5 studies used health adult participants who were supplemented with at least 4 g/d of betaine for between 6 and 24 weeks. A meta-analysis was carried out using a random-effects model, and the overall effect size was calculated for changes in plasma homocysteine. RESULTS The pooled estimate of effect for betaine supplementation on plasma homocysteine was a reduction of 1.23 μmol/L, which was statistically significant (95% confidence interval, - 1.61 to - 0.85; P = .01). CONCLUSION Supplementation with at least 4g/d of betaine for a minimum of 6 weeks can lower plasma homocysteine.
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Affiliation(s)
- Marc P McRae
- Associate Professor, Department of Basic Science, National University of Health Sciences, Lombard, IL
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Maclean KN, Jiang H, Greiner LS, Allen RH, Stabler SP. Long-term betaine therapy in a murine model of cystathionine beta-synthase deficient homocystinuria: decreased efficacy over time reveals a significant threshold effect between elevated homocysteine and thrombotic risk. Mol Genet Metab 2012; 105:395-403. [PMID: 22192524 DOI: 10.1016/j.ymgme.2011.11.190] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 11/16/2011] [Indexed: 11/22/2022]
Abstract
Classical homocystinuria (HCU) is caused by deficiency of cystathionine β-synthase and is characterized by connective tissue disturbances, mental retardation and cardiovascular disease. Treatment for pyridoxine non-responsive HCU typically involves lowering homocysteine levels with a methionine-restricted diet and dietary supplementation with betaine. Compliance with the methionine-restricted diet is difficult and often poor. Investigating optimization of the efficacy of long-term betaine treatment in isolation from a methionine-restricted diet is precluded by ethical considerations regarding patient risk. The HO mouse model of HCU developed in our laboratory, exhibits constitutive expression of multiple pro-inflammatory cytokines and a hypercoagulative phenotype both of which respond to short-term betaine treatment. Investigation of the effects of long-term betaine treatment in the absence of methionine-restriction in HO HCU mice revealed that the ability of betaine treatment to lower homocysteine diminished significantly over time. Plasma metabolite analysis indicated that this effect was due at least in part, to reduced betaine-homocysteine S-methyltransferase (BHMT) mediated remethylation of homocysteine. Western blotting analysis revealed that BHMT protein levels are significantly repressed in untreated HCU mice but are significantly induced in the presence of betaine treatment. The observed increase in plasma homocysteine during prolonged betaine treatment was accompanied by a significant increase in the plasma levels of TNF-alpha and IL-1beta and reversion to a hypercoagulative phenotype. Our findings are consistent with a relatively sharp threshold effect between severely elevated plasma homocysteine and thrombotic risk in HCU and indicate that the HO mouse model can serve as a useful tool for both testing novel treatment strategies and examining the optimal timing and dosing of betaine treatment with a view toward optimizing clinical outcome.
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Affiliation(s)
- Kenneth N Maclean
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045-0511, USA.
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10
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Ucar SK, Koroğlu OA, Berk O, Yalaz M, Kültürsay N, Blom HJ, Coker M. Titration of betaine therapy to optimize therapy in an infant with 5,10-methylenetetrahydrofolate reductase deficiency. Eur J Pediatr 2010; 169:241-3. [PMID: 19434424 DOI: 10.1007/s00431-009-0997-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 05/05/2009] [Indexed: 11/30/2022]
Abstract
Betaine therapy was given for 2 years to a 2-year-old boy with 5,10-methylenetetrahydrofolate reductase deficiency. Used as a methyl donor to lower homocysteine levels through methylation of methionine, betaine has been reported to be effective in treating homocystinuria. Satisfactory biochemical and clinical responses were obtained with the following regimen: betaine started in the newborn period at increasing doses to reach 1 g given six times a day. It is suggested that frequent administration of a moderate dose may provide clinical and biochemical benefit.
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Affiliation(s)
- Sema Kalkan Ucar
- Department of Pediatrics, Ege University Medical Faculty, Izmir, Turkey.
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Atkinson W, Elmslie J, Lever M, Chambers ST, George PM. Dietary and supplementary betaine: acute effects on plasma betaine and homocysteine concentrations under standard and postmethionine load conditions in healthy male subjects. Am J Clin Nutr 2008; 87:577-85. [PMID: 18326594 DOI: 10.1093/ajcn/87.3.577] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Betaine comes from the diet and from choline, and it is associated with vascular disease in some patient groups. Betaine supplementation lowers plasma total homocysteine. OBJECTIVE We compared the acute effects of dietary and supplementary betaine and choline on plasma betaine and homocysteine under standard conditions and after a methionine load. DESIGN In a randomized crossover study, 8 healthy men (19-40 y) consumed a betaine supplement (approximately 500 mg), high-betaine meal (approximately 517 mg), choline supplement (500 mg), high-choline meal (approximately 564 mg), high-betaine and -choline meal (approximately 517 mg betaine, approximately 622 mg choline), or a low-betaine and -choline control meal under standard conditions or postmethionine load. Plasma betaine, dimethylglycine, and homocysteine concentrations were measured hourly for 8 h and at 24 h after treatment. RESULTS Dietary and supplementary betaine raised plasma betaine concentrations relative to control (P < 0.001) under standard conditions. This was not associated with raised plasma dimethylglycine concentration, and no significant betaine appeared in the urine. A small increase in dimethylglycine excretion was observed when either betaine or choline was supplied (P = 0.011 and < 0.001). Small decreases in plasma homocysteine 6 h after ingestion under standard conditions (P < or = 0.05) were detected after a high-betaine meal and after a high-betaine and high-choline meal. Dietary betaine and choline and betaine supplementation attenuated the increase in plasma homocysteine at both 4 and 6 h after a methionine load (P < or = 0.001). CONCLUSIONS Dietary betaine and supplementary betaine acutely increase plasma betaine, and they and choline attenuate the postmethionine load rise in homocysteine concentrations.
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Affiliation(s)
- Wendy Atkinson
- Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
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Alfthan G, Tapani K, Nissinen K, Saarela J, Aro A. The effect of low doses of betaine on plasma homocysteine in healthy volunteers. Br J Nutr 2007; 92:665-9. [PMID: 15522136 DOI: 10.1079/bjn20041253] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Homocysteine is a risk factor for vascular diseases, and lowering of plasma total homocysteine (tHcy) may be beneficial for health. Homocysteine can be remethylated to methionine by betaine–homocysteine methyltransferase using betaine (2(N,N,N-trimethyl)glycine) as methyl donor. A dose of 6 g betaine/d has been used in the treatment of homocystinuria, but data on the dose–response are scarce. Thirty-four healthy men and women were supplied with doses of 1, 3 and 6 g betaine and then with 6 g betaine + 1 mg folic acid for four consecutive 1-week periods. The mean plasma tHcy concentration decreased by 1·1 (NS), 10·0 and 14·0 % (P<0·001) after supplementation with 1, 3 and 6 g betaine respectively. A further decrease in plasma tHcy by 5 % (P<0·01) was achieved by combining 1 mg folic acid with the 6 g betaine dose. Plasma betaine increased from 31 (SD 13) to 255 (SD 136) μmol/l in a dose-dependent manner (R20·97). We conclude that plasma tHcy is lowered rapidly and significantly by 3 or 6 g betaine/d in healthy men and women.
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Affiliation(s)
- Georg Alfthan
- Department of Health and Functional Capacity, National Public Health Institute (KTL), Helsinki, Finland.
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Thwaites DT, Anderson CMH. Deciphering the mechanisms of intestinal imino (and amino) acid transport: The redemption of SLC36A1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:179-97. [PMID: 17123464 DOI: 10.1016/j.bbamem.2006.10.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Revised: 09/26/2006] [Accepted: 10/02/2006] [Indexed: 11/23/2022]
Abstract
The absorption of zwitterionic imino and amino acids, and related drugs, is an essential function of the small intestinal epithelium. This review focuses on the physiological roles of transporters recently identified at the molecular level, in particular SLC36A1, by identifying how they relate to the classical epithelial imino and amino acid transporters characterised in mammalian small intestine in the 1960s-1990s. SLC36A1 transports a number of D- and L-imino and amino acids, beta- and gamma-amino acids and orally-active neuromodulatory and antibacterial agents. SLC36A1 (or PAT1) functions as a proton-coupled imino and amino acid symporter in cooperation with the Na+/H+ exchanger NHE3 (SLC9A3) to produce the imino acid carrier identified in rat small intestine in the 1960s but subsequently ignored because of confusion with the IMINO transporter. However, it is the sodium/imino and amino acid cotransporter SLC6A20 which corresponds to the betaine carrier (identified in hamster, 1960s) and IMINO transporter (identified in rabbit and guinea pig, 1980s). This review summarises evidence for expression of SLC36A1 and SLC6A20 in human small intestine, highlights the differences in functional characteristics of the imino acid carrier and IMINO transporter, and explains the confusion surrounding these two distinct transport systems.
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Affiliation(s)
- David T Thwaites
- Epithelial Research Group, Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Framlington Place, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, UK.
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Moat SJ, Madhavan A, Taylor SY, Payne N, Allen RH, Stabler SP, Goodfellow J, McDowell IFW, Lewis MJ, Lang D. High- but not low-dose folic acid improves endothelial function in coronary artery disease. Eur J Clin Invest 2006; 36:850-9. [PMID: 17087779 DOI: 10.1111/j.1365-2362.2006.01739.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND While folic acid (FA) reduces plasma homocysteine (Hcy), whether the simultaneous improvement in endothelial function is dependent on Hcy lowering per se is questionable. In the present study the relationship between FA dose, Hcy lowering and endothelial function in patients with coronary artery disease (CAD) was investigated. MATERIALS AND METHODS Eighty-four patients with CAD received either 400 microg FA or 5 mg placebo daily for a 6-week treatment period. A further 44 patients with CAD received either 100 mg kg(-1) day(-1) of betaine or placebo for a 6-week treatment period. Flow-mediated dilatation (FMD), a measure of endothelial function, was assessed before and after the 6-week periods. Isometric tension and Western blotting were used to investigate the effect of FA on endothelial function and endothelial nitric oxide synthase (eNOS) dimerization in isolated rabbit aortic rings and cultured porcine aortic endothelial cells (PAEC), respectively. RESULTS Both 400 micro g day(-1) and 5 mg day(-1) FA significantly increased plasma folate and decreased plasma Hcy. The FMD improved significantly after 6 weeks' treatment of 5 mg day(-1) FA but did not correlate with the reduction in Hcy. There was no change in FMD in either the 400 micro g FA or placebo group. In a subgroup analysis of 11 patients in the betaine group, despite a reduced Hcy, a significant impairment in FMD was observed. In the in vitro studies FA, but not betaine, reversed methionine-induced endothelial dysfunction. Moreover, the FA promoted eNOS dimerization in cultured PAEC. CONCLUSIONS These data suggest that FA dose-dependently improves endothelial function in CAD via a mechanism independently of Hcy lowering. It may involve promotion of eNOS dimerization.
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Affiliation(s)
- S J Moat
- Department of Medical Biochemistry, University Hospital of Wales, Cardiff, UK
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15
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Pierre G, Gissen P, Chakrapani A, McDonald A, Preece M, Wright J. Successful treatment of pyridoxine-unresponsive homocystinuria with betaine in pregnancy. J Inherit Metab Dis 2006; 29:688-9. [PMID: 16972179 DOI: 10.1007/s10545-006-0352-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 06/03/2006] [Accepted: 06/12/2006] [Indexed: 10/24/2022]
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Schwab U, Törrönen A, Meririnne E, Saarinen M, Alfthan G, Aro A, Uusitupa M. Orally administered betaine has an acute and dose-dependent effect on serum betaine and plasma homocysteine concentrations in healthy humans. J Nutr 2006; 136:34-8. [PMID: 16365055 DOI: 10.1093/jn/136.1.34] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Betaine, i.e., trimethylglycine, is linked to homocysteine metabolism. A 3-mo daily betaine supplementation decreased even normal plasma total homocysteine (tHcy) concentrations in humans. The pharmacokinetic characteristics and metabolism of betaine in humans have not been investigated in detail. The aim of this study was to assess the pharmacokinetics of orally administered betaine and its acute effect on plasma tHcy concentrations. Healthy volunteers (n = 10; 3 men, 7 women) with normal body weight (mean +/- SD, 69.5 +/- 17.0 kg), 40.8 +/- 12.4 y old, participated in the study. The betaine doses were 1, 3, and 6 g. The doses were mixed with 150 mL of orange juice and ingested after a 12-h overnight fast by each volunteer according to a randomized double-blind crossover design. Blood samples were drawn for 24 h and a 24-h urine collection was performed. Orally administered betaine had an immediate and dose-dependent effect on serum betaine concentration. Single doses of 3 and 6 g lowered plasma tHcy concentrations (P = 0.019 and P < 0.001, respectively), unlike the 1-g dose. After the highest dose, the concentrations remained low during the 24 h of monitoring. The change in plasma tHcy concentration was linearly associated with betaine dose (P = 0.006) and serum betaine concentration (R2 = 0.17, P = 0.025). The absorption and elimination of betaine were dose dependent. The urinary excretion of betaine seemed to increase with an increasing betaine dose, although a very small proportion of ingested betaine was excreted via urine. In conclusion, a single dose of orally administered betaine had an acute and dose-dependent effect on serum betaine concentration and resulted in lowered plasma tHcy concentrations within 2 h in healthy subjects.
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Affiliation(s)
- Ursula Schwab
- Department of Clinical Nutrition, University of Kuopio, Finland.
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17
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Abstract
Most of the drugs on the market are originally developed for adults and dosage selection is based on an optimal balance between clinical efficacy and safety. The aphorism 'children are not small adults' not only holds true for the selection of suitable drugs and dosages for use in children but also their susceptibility to adverse drug reactions. Since children may not be subject to dose escalation studies similar to those carried out in the adult population, some initial estimation of dose in paediatrics should be obtained via extrapolation approaches. However, following such an exercise, well-conducted PK-PD or PK studies will still be needed to determine the most appropriate doses for neonates, infants, children and adolescents.
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Affiliation(s)
- Trevor N Johnson
- Simcyp Ltd, Blades Enterprise Centre, John Street, Sheffield S2 4SU, UK.
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Opinion of the Scientific Panel on Dietetic products, nutrition and allergies [NDA] related to an application concerning the use of betaine as a novel food in the EU. EFSA J 2005. [DOI: 10.2903/j.efsa.2005.191] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Abstract
Betaine is distributed widely in animals, plants, and microorganisms, and rich dietary sources include seafood, especially marine invertebrates ( approximately 1%); wheat germ or bran ( approximately 1%); and spinach ( approximately 0.7%). The principal physiologic role of betaine is as an osmolyte and methyl donor (transmethylation). As an osmolyte, betaine protects cells, proteins, and enzymes from environmental stress (eg, low water, high salinity, or extreme temperature). As a methyl donor, betaine participates in the methionine cycle-primarily in the human liver and kidneys. Inadequate dietary intake of methyl groups leads to hypomethylation in many important pathways, including 1) disturbed hepatic protein (methionine) metabolism as determined by elevated plasma homocysteine concentrations and decreased S-adenosylmethionine concentrations, and 2) inadequate hepatic fat metabolism, which leads to steatosis (fatty accumulation) and subsequent plasma dyslipidemia. This alteration in liver metabolism may contribute to various diseases, including coronary, cerebral, hepatic, and vascular diseases. Betaine has been shown to protect internal organs, improve vascular risk factors, and enhance performance. Databases of betaine content in food are being developed for correlation with population health studies. The growing body of evidence shows that betaine is an important nutrient for the prevention of chronic disease.
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Affiliation(s)
- Stuart A S Craig
- Danisco USA Inc., 440 Saw Mill River Road, Ardsley, NY 10502, USA.
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Slow S, Lever M, Lee MB, George PM, Chambers ST. Betaine analogues alter homocysteine metabolism in rats. Int J Biochem Cell Biol 2004; 36:870-80. [PMID: 15006639 DOI: 10.1016/j.biocel.2003.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Glycine betaine supplementation lowers homocysteine levels in homocystinuria and in chronic renal failure patients through methylation catalysed by betaine-homocysteine methyltransferase (BHMT). The aim of this study was to determine the effect of glycine betaine analogues on homocysteine metabolism in Lewis rats. Glycine betaine, proline betaine, trigonelline, dimethylsulfoniopropionate (DMSP) or dimethylthetin (1.5 mmoles) was subcutaneously administered to rats fed a low betaine diet. The effect of each betaine on total plasma homocysteine and urinary and plasma betaine concentrations was monitored for 24h following administration. Baseline plasma homocysteine was 8.5 +/- micromol/l (S.E.M., n=44) and compared to controls concentrations decreased following glycine betaine (0.8+/-0.4 micromol/l, P = 0.064), DMSP (1.0+/-0.5 micromol/l, P = 0.041) and dimethylthetin (1.5 +/- 0.7micromol/l, P = 0.033) treatment, while concentrations increased following proline betaine (2.24 +/-0.7micromol/l, P = 0.002) and trigonelline (1.6 +/-0.3 micromol/l, P < 0.001) treatment. The effect of glycine betaine, DMSP and dimethylthetin on circulating homocysteine concentrations was thought to be mediated by BHMT in vivo. This hypothesis was supported by the finding that circulating glycine betaine concentrations increased following DMSP and dimethylthetin treatment. Proline betaine and trigonelline appeared to be poor BHMT substrates, being largely excreted in the urine unchanged, yet increased circulating homocysteine levels. This suggests they are inhibitors of BHMT. Urinary excretion of glycine betaine increased following treatment with all betaines, suggesting that the resorption of glycine betaine in the kidney was inhibited. The study shows that glycine betaine analogues have multiple effects on homocysteine metabolism (250).
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Affiliation(s)
- Sandy Slow
- Biochemistry Unit, Canterbury Health Laboratories, PO Box 151, Christchurch, New Zealand.
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Devlin AM, Hajipour L, Gholkar A, Fernandes H, Ramesh V, Morris AAM. Cerebral edema associated with betaine treatment in classical homocystinuria. J Pediatr 2004; 144:545-8. [PMID: 15069409 DOI: 10.1016/j.jpeds.2003.12.041] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A child with cystathionine beta-synthase deficiency developed cerebral edema 4 to 6 weeks after starting betaine therapy. There was no evidence of intracranial thrombosis, but there was widespread edema of the white matter. He recovered fully after emergency decompressive craniotomy and withdrawal of betaine.
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Affiliation(s)
- A M Devlin
- Departments of Paediatric Neurology and Neurosurgery, Newcastle General Hospital, Newcastle-upon-Tyne, United Kingdom
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Nunes C, Han J, Monkhouse DC, Suryanarayanan R. Preformulation Studies to Meet the Challenges in the Manufacture of Betaine Solid Dosage Form. J Pharm Sci 2004; 93:38-47. [PMID: 14648634 DOI: 10.1002/jps.10508] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The objectives were (1). to perform solid-state characterization of anhydrous betaine (A) and betaine monohydrate (M), (2). to develop a pressure differential scanning calorimetric (DSC) technique for the quantification of M when present as a minor component in a mixture with A and, (3). to study the effect of annealing of A on the kinetics of A --> M transition. X-ray powder diffractometer (XRD), DSC, thermogravimetric analyzer (TGA), and an automated moisture sorption apparatus were used to characterize the phases. DSC at an elevated pressure of 200 psi enabled quantification of M in mixtures of A and M. Humidity-controlled TGA allowed study of the kinetics of A --> M transition. Automated moisture studies showed that A has a strong tendency to sorb water (at RH >or= 20%, 25 degrees C) and convert to M. When M was subjected to DSC at ambient pressure, the endotherms due to dehydration and vaporization of water overlapped. Pressure DSC enabled separation of these two thermal events. In mixtures of A and M, the enthalpy of dehydration (deltaH(d)) of M could be used for its quantification. A linear relationship was obtained when deltaH(d) was plotted as a function of the weight fraction of M in the mixture. The limits of detection and quantification of M in A were 0.15% and 1.5% w/w, respectively. The kinetics of water uptake by the annealed as well as the unannealed A, could be best described by the Avrami-Erofeev model (three-dimensional nucleation and growth). The calculated rate constant (k) of unannealed A (0.075 +/- 0.002 min(-1)) was significantly higher than that of annealed A (0.052 +/- 0.004 min(-1)). DSC at elevated pressure was a sensitive technique for quantification of M when present as a mixture with A. Annealing of A decelerated the A --> M phase transition reaction, possibly by increasing the degree of crystallinity of A.
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Affiliation(s)
- Cletus Nunes
- Department of Pharmaceutics, 308 Harvard St SE, University of Minnesota, Minneapolis, Minnesota 55455, USA
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