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González-Lamuño D, Arrieta-Blanco FJ, Fuentes ED, Forga-Visa MT, Morales-Conejo M, Peña-Quintana L, Vitoria-Miñana I. Hyperhomocysteinemia in Adult Patients: A Treatable Metabolic Condition. Nutrients 2023; 16:135. [PMID: 38201964 PMCID: PMC10780827 DOI: 10.3390/nu16010135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/26/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
Hyperhomocysteinemia (HHcy) is recognized as an independent risk factor for various significant medical conditions, yet controversy persists around its assessment and management. The diagnosis of disorders afffecting homocysteine (Hcy) metabolism faces delays due to insufficient awareness of its clinical presentation and unique biochemical characteristics. In cases of arterial or venous thrombotic vascular events, particularly with other comorbidities, it is crucial to consider moderate to severe HHcy. A nutritional approach to HHcy management involves implementing dietary strategies and targeted supplementation, emphasizing key nutrients like vitamin B6, B12, and folate that are crucial for Hcy conversion. Adequate intake of these vitamins, along with betaine supplementation, supports Hcy remethylation. Lifestyle modifications, such as smoking cessation and regular physical activity, complement the nutritional approach to enhance Hcy metabolism. For individuals with HHcy, maintaining a plasma Hcy concentration below 50 μmol/L consistently is vital to lowering the risk of vascular events. Collaboration with healthcare professionals and dietitians is essential for developing personalized dietary plans addressing the specific needs and underlying health conditions. This integrated approach aims to optimize metabolic processes and reduce the associated health risks.
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Affiliation(s)
| | | | - Elena Dios Fuentes
- Endocrinology and Nutrition Department, Virgen del Rocío University Hospital, 41013 Sevilla, Spain;
| | | | - Monstserrat Morales-Conejo
- Unit for Congenital Metabolic Diseases and Other Rare Diseases, Internal Medicine Department, 12 de Octubre University Hospital, 28041 Madrid, Spain;
| | - Luis Peña-Quintana
- Pediatric Gastroenterology and Nutrition Unit, Insular Materno-Infantil University Hospital Complex, Asociación Canaria de Investigación Pediátrica, Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y Nutrición, University of Las Palmas de Gran Canaria, 35016 Las Palmas de Gran Canaria, Spain;
| | - Isidro Vitoria-Miñana
- Nutrition and Metabolic Diseases Unit, La Fe University Hospital, 46026 Valencia, Spain
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Omorou M, Liu N, Huang Y, Al-Ward H, Gao M, Mu C, Zhang L, Hui X. Cystathionine beta-Synthase in hypoxia and ischemia/reperfusion: A current overview. Arch Biochem Biophys 2022; 718:109149. [DOI: 10.1016/j.abb.2022.109149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/04/2022] [Accepted: 02/07/2022] [Indexed: 11/02/2022]
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Hua N, Ning Y, Zheng H, Zhao L, Qian X, Wormington C, Wang J. Recurrent dislocation of binocular crystal lenses in a patient with cystathionine beta-synthase deficiency. BMC Ophthalmol 2021; 21:212. [PMID: 33985475 PMCID: PMC8120774 DOI: 10.1186/s12886-021-01974-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 05/05/2021] [Indexed: 12/03/2022] Open
Abstract
Background Ectopia lentis is the common ocular manifestation of homocystinuria resulting from cystathionine beta-synthase (CBS) deficiency which has a high risk of thromboembolic complications. Case presentation The present study reports the case of a teenager with recurrent lens dislocation and glaucoma. He was diagnosed with CBS deficiency according to a high level of serum homocysteine and compound heterozygous mutations at two different positions on the CBS gene. Antiglaucoma eyedrops and a mydriatic successfully controlled the intraocular pressure, while oral pyridoxine and betaine uptake lowered the serum homocysteine level effectively. Conclusions Children with CBS deficiency may suffer from ectopia lentis, glaucoma and/or amblyopia. We firstly discovered a new mutation of CBS c. 697 T > G which had not been reported before. The patient was pyridoxine responsive and well controlled by medicine.
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Affiliation(s)
- Ning Hua
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251 Fukang Road, Nankai District, Tianjin, China.
| | - Yuxian Ning
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251 Fukang Road, Nankai District, Tianjin, China
| | - Hui Zheng
- Tianjin Eye Hospital, Tianjin, China
| | - Ledong Zhao
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251 Fukang Road, Nankai District, Tianjin, China
| | - Xuehan Qian
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251 Fukang Road, Nankai District, Tianjin, China
| | - Charles Wormington
- Salus Univerisity Pennsylvania College of Optometry, Elkins Park, PA, USA
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Levy J, Rodriguez-Guéant RM, Oussalah A, Jeannesson E, Wahl D, Ziuly S, Guéant JL. Cardiovascular manifestations of intermediate and major hyperhomocysteinemia due to vitamin B12 and folate deficiency and/or inherited disorders of one-carbon metabolism: a 3.5-year retrospective cross-sectional study of consecutive patients. Am J Clin Nutr 2021; 113:1157-1167. [PMID: 33693455 DOI: 10.1093/ajcn/nqaa432] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 12/16/2020] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The association of moderate hyperhomocysteinemia (HHcy) (15-30 μmol/L) with cardiovascular diseases (CVD) has been challenged by the lack of benefit of vitamin supplementation to lowering homocysteine. Consequently, the results of interventional studies have confused the debate regarding the management of patients with intermediate/severe HHcy. OBJECTIVE We sought to evaluate the association of intermediate (30-100 μmol/L) and severe (>100 μmol/L) HHcy related to vitamin deficiencies and/or inherited disorders with CVD outcomes. METHODS We performed a retrospective cross-sectional study on consecutive patients who underwent a homocysteine assay in a French University Regional Hospital Center. Patients with CVD outcomes were assessed for vitamin B12, folate, Hcy, methylmalonic acid, and next-generation clinical exome sequencing. RESULTS We evaluated 165 patients hospitalized for thromboembolic and other cardiovascular (CV) manifestations among 1006 patients consecutively recruited. Among them, 84% (138/165) had Hcy >30 μmol/L, 27% Hcy >50 μmol/L (44/165) and 3% Hcy >100 μmol/L (5/165). HHcy was related to vitamin B12 and/or folate deficiency in 55% (87/165), mutations in one or more genes of one-carbon and/or vitamin B12 metabolisms in 11% (19/165), and severe renal failure in 15% (21/141) of the studied patients. HHcy was the single vascular risk retrieved in almost 9% (15/165) of patients. Sixty % (101/165) of patients received a supplementation to treat HHcy, with a significant decrease in median Hcy from 41 to 17 µmol/L (IQR: 33.6-60.4 compared with 12.1-28). No recurrence of thromboembolic manifestations was observed after supplementation and antithrombotic treatment of patients who had HHcy as a single risk, after ∼4 y of follow-up. CONCLUSION The high frequency of intermediate/severe HHcy differs from the frequent moderate HHcy reported in previous observational studies of patients with pre-existing CVD. Our study points out the importance of diagnosing and treating nutritional deficiencies and inherited disorders to reverse intermediate/severe HHcy associated with CVD outcomes.
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Affiliation(s)
- Julien Levy
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital (CHRU) of Nancy, Nancy, France.,Reference Centre for Inborn Errors of Metabolism (ORPHA67872), University Hospital (CHRU) of Nancy, Nancy, France
| | - Rosa-Maria Rodriguez-Guéant
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital (CHRU) of Nancy, Nancy, France.,Reference Centre for Inborn Errors of Metabolism (ORPHA67872), University Hospital (CHRU) of Nancy, Nancy, France.,INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM, Nancy, France
| | - Abderrahim Oussalah
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital (CHRU) of Nancy, Nancy, France.,Reference Centre for Inborn Errors of Metabolism (ORPHA67872), University Hospital (CHRU) of Nancy, Nancy, France.,INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM, Nancy, France
| | - Elise Jeannesson
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital (CHRU) of Nancy, Nancy, France.,Reference Centre for Inborn Errors of Metabolism (ORPHA67872), University Hospital (CHRU) of Nancy, Nancy, France
| | - Denis Wahl
- INSERM UMR_S 1116 DCAC and CHRU-Nancy, Vascular Medicine Division and Regional Competence Center for Rare Auto-Immune Diseases, University of Lorraine, INSERM, University Hospital (CHRU) of Nancy, Nancy, France
| | - Stéphane Ziuly
- INSERM UMR_S 1116 DCAC and CHRU-Nancy, Vascular Medicine Division and Regional Competence Center for Rare Auto-Immune Diseases, University of Lorraine, INSERM, University Hospital (CHRU) of Nancy, Nancy, France
| | - Jean-Louis Guéant
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital (CHRU) of Nancy, Nancy, France.,Reference Centre for Inborn Errors of Metabolism (ORPHA67872), University Hospital (CHRU) of Nancy, Nancy, France.,INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM, Nancy, France
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Nedelcu C, Ionescu M, Pantea-Stoian A, Niţă D, Petcu L, Mazilu L, Suceveanu AI, Tuţă LA, Parepa IR. Correlation between plasma homocysteine and first myocardial infarction in young patients: Case-control study in Constanta County, Romania. Exp Ther Med 2020; 21:101. [PMID: 33363612 DOI: 10.3892/etm.2020.9533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 10/30/2020] [Indexed: 11/06/2022] Open
Abstract
An elevated level of total plasma homocysteine has been associated with a higher risk of atherosclerosis and coronary heart disease. The aim of our research was to study the relation between homocysteine and myocardial infarction (MI) in young patients. We conducted a case-control study in Constanţa County, Romania including 61 patients, divided in two groups. The first group, the MI group, consisted of 28 patients, male (67.9%) and female (32.1%) aged less than 45 years who were consecutively admitted to the Intensive Coronary Care Unit of the Emergency County Hospital of Constanţa from September 1, 2017 to August 31, 2018 (12 months), with an established diagnosis of first acute MI. The second group, the control group, included 33 patients, male (75.8%) and female (24.2%) aged less than 45 years, with cardiovascular risk factors and/or stable angina pectoris that were consecutively addressed for ambulatory cardiac evaluation at the Outpatient Clinic of Emergency County Hospital of Constanţa during the same period. Fasting plasma homocysteine was determined in both groups, within 24 h after MI onset, respectively after first cardiac exam in the controls. High homocysteine was statistically confirmed to be a risk factor in the study group, especially in association with smoking, chronic kidney disease (CKD), and to a lesser extent with diabetes mellitus (DM) and hypertension. Data analysis was performed using IBM SPSS Statistics 23. The procedures used included descriptive statistics, parametric statistical tests (Independent sample t-test), non-parametric statistical tests [Chi-square test of the association, with the evaluation of odds ratio (OR)]; the significance level used in the analysis (P-value) was 0.05. After adjusting for variables, our study results pointed out a strong association between plasma homocysteine and first acute MI among young patients, emphasising plasma homocysteine as a possible risk factor for myocardial infarction.
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Affiliation(s)
- Cristina Nedelcu
- Cardiology Department, Constanta County Army Hospital, 900527 Constanţa, Romania
| | - Mihaela Ionescu
- Department of Clinical Medical Sciences, Faculty of General Medicine, 'Ovidius' University of Constanţa, 900527 Constanţa, Romania
| | - Anca Pantea-Stoian
- Department of Metabolic Diseases of the Clinical Emergency Hospital, 'Carol Davila' University of Medicine and Pharmacy Bucharest, 050474 Bucharest, Romania
| | - Daniel Niţă
- Department of Interventional Cardiology, Army's Center for Cardiovascular Diseases, 010825 Bucharest, Romania
| | - Lucian Petcu
- Department of Biophysics, Faculty of General Medicine, 'Ovidius' University of Constanţa, 900527 Constanta, Romania
| | - Laura Mazilu
- Department of Clinical Medical Sciences, Faculty of General Medicine, 'Ovidius' University of Constanţa, 900527 Constanţa, Romania
| | - Andra-Iulia Suceveanu
- Department of Clinical Medical Sciences, Faculty of General Medicine, 'Ovidius' University of Constanţa, 900527 Constanţa, Romania
| | - Liliana-Ana Tuţă
- Department of Clinical Medical Sciences, Faculty of General Medicine, 'Ovidius' University of Constanţa, 900527 Constanţa, Romania
| | - Irinel-Raluca Parepa
- Department of Clinical Medical Sciences, Faculty of General Medicine, 'Ovidius' University of Constanţa, 900527 Constanţa, Romania
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Park I, Johnson LK, Cox A, Branchford BR, Paola JD, Bublil EM, Majtan T. Hypermethioninemia Leads to Fatal Bleeding and Increased Mortality in a Transgenic I278T Mouse Model of Homocystinuria. Biomedicines 2020; 8:biomedicines8080244. [PMID: 32722248 PMCID: PMC7459533 DOI: 10.3390/biomedicines8080244] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 01/20/2023] Open
Abstract
Severely elevated plasma homocysteine and methionine lead to thromboembolic events and strokes in homocystinuric (HCU) patients. Mouse models of HCU failed to exhibit prothrombotic phenotype, presumably due to lack of hypermethioninemia. We evaluated the impact of hypermethioninemia together with hyperhomocysteinemia on murine HCU phenotype and compared the efficacy of the current and novel therapies for HCU. High methionine intake decreased survival of I278T mice, which died from intestinal bleeding with hepatic and pancreatic failure. I278T mice on normal or increased methionine intake developed endothelial dysfunction, but paradoxically demonstrated delayed occlusion in an induced arterial thrombosis model. RNA-seq analysis suggested that expression of coagulation factor XI (FXI) is downregulated in livers of I278T mice. Indeed, plasma concentrations of FXI were decreased in I278T mice on normal diet and further reduced by increased methionine intake. Dietary methionine restriction normalized the observed phenotype. Similarly, treatment with OT-58, a novel enzyme therapy for HCU, corrected the phenotype in I278T mice regardless of their dietary methionine intake. Hypermethioninemia does not contribute to prothrombotic phenotype in murine HCU. Downregulation of FXI may contribute to the lack of prothrombotic tendency in I278T mice. Methionine restriction or treatment with OT-58 corrects vascular disease in the I278T mouse model of HCU.
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Affiliation(s)
- Insun Park
- Section of Genetics & Metabolism, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - Linda K. Johnson
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - Allaura Cox
- Section of Hematology/Oncology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA; (A.C.); (B.R.B.); (J.D.P.)
- University of Colorado Hemophilia and Thrombosis Center, Aurora, CO 80045, USA
| | - Brian R. Branchford
- Section of Hematology/Oncology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA; (A.C.); (B.R.B.); (J.D.P.)
- University of Colorado Hemophilia and Thrombosis Center, Aurora, CO 80045, USA
| | - Jorge Di Paola
- Section of Hematology/Oncology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA; (A.C.); (B.R.B.); (J.D.P.)
- University of Colorado Hemophilia and Thrombosis Center, Aurora, CO 80045, USA
| | | | - Tomas Majtan
- Section of Genetics & Metabolism, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
- Correspondence: ; Tel.: +1-303-724-3813
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7
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Urquhart BL, House AA. Assessing Plasma Total Homocysteine in Patients with End-Stage Renal Disease. Perit Dial Int 2020. [DOI: 10.1177/089686080702700502] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Elevated plasma total homocysteine (tHcy) is a risk factor for cardiovascular disease; however, in light of several recent randomized trials, the issue of causality has been cast into doubt. Patients with end-stage renal disease are particularly interesting as they consistently have elevated tHcy and their leading causes of morbidity and mortality are related to cardiovascular disease. In the present article, we review the early evidence for the homocysteine theory of atherosclerosis, homocysteine metabolism, mechanisms of toxicity, and pertinent available clinical investigations. Where appropriate, the sparse evidence of homocysteine in peritoneal dialysis is reviewed. We conclude by addressing the difficulties associated with lowering plasma tHcy in patients with end-stage renal disease and suggest some novel methods for lowering tHcy in this resistant population. Finally, to address the issue of causality, we recommend that clinicians and scientists await the results of the FAVORIT trial before abandoning homocysteine as a modifiable risk factor for cardiovascular disease, as this study has recruited patients from a population with consistently elevated plasma tHcy who are known to respond to vitamin therapy.
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Affiliation(s)
- Bradley L. Urquhart
- Departments of Medicine The University of Western Ontario, London, Ontario, Canada
- Physiology/Pharmacology, The University of Western Ontario, London, Ontario, Canada
| | - Andrew A. House
- Departments of Medicine The University of Western Ontario, London, Ontario, Canada
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8
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Hoss GRW, Poloni S, Blom HJ, Schwartz IVD. Three Main Causes of Homocystinuria: CBS, cblC and MTHFR Deficiency. What do they Have in Common? JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2019. [DOI: 10.1590/2326-4594-jiems-2019-0007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
| | - Soraia Poloni
- Universidade Federal do Rio Grande do Sul, Brazil; Hospital de Clínicas de Porto Alegre, Brazil
| | - Henk J Blom
- University Medical Centre Amsterdam, Netherlands
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9
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Şahin MM, Uğur MB, Karamert R, Aytekin S, Kabiş B, Düzlü M, Seymen C, Elmas Ç, Gökdoğan Ç, Ünlü S. Evaluation of Effect of Garlic Aged Extracts and Vitamin B12 on Noise-Induced Hearing Loss. Noise Health 2018; 20:232-239. [PMID: 31823910 PMCID: PMC6924192 DOI: 10.4103/nah.nah_33_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE This study investigated effects of S-allylmercaptocysteine (SAMC), diallyl disulfide (DADS), and vitamin B12 on inner ear functions and morphology after long-period high-level broadband noise exposure. MATERIALS AND METHODS Twenty-four healthy rats were randomly divided into four groups. First group was chosen as the control group. Vitamin B12, SAMC, and DADS were applied to other groups for 4 weeks. On the 14th day, each group was exposed to broadband noise. Auditory brainstem response test was performed before and immediately after noise exposure and repeated on the 2nd and 14th day. RESULTS Permanent threshold shifts were significantly lower in groups treated with vitamin B12, SAMC, and DADS. Histologically, cochleae of SAMC and DADS groups were found to be better preserved than the cochleae of vitamin B12 and control groups. CONCLUSION Physiologically and histologically, SAMC and DADS reduced the long-term effects of noise. However, physiological recovery was not consistent with the morphological findings in vitamin B12 group.
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Affiliation(s)
- Muammer M. Şahin
- Department of Otorhinolaryngology, Head and Neck Surgery, Ankara Numune Hospital, Ankara, Turkey
| | - Mehmet B. Uğur
- Department of Otorhinolaryngology, Head and Neck Surgery, Ankara Gazi University Hospital, Ankara, Turkey
| | - Recep Karamert
- Department of Otorhinolaryngology, Head and Neck Surgery, Ankara Gazi University Hospital, Ankara, Turkey
| | - Sinem Aytekin
- Department of Pathology, Ankara Gazi University Hospital, Ankara, Turkey
| | - Burak Kabiş
- Department of Audiology, Ankara Gazi University Hospital, Ankara, Turkey
| | - Mehmet Düzlü
- Department of Otorhinolaryngology, Head and Neck Surgery, Ankara Gazi University Hospital, Ankara, Turkey
| | - Cemile Seymen
- Department of Histology and Embryology, Ankara Gazi University Hospital, Ankara, Turkey
| | - Çiğdem Elmas
- Department of Histology and Embryology, Ankara Gazi University Hospital, Ankara, Turkey
| | - Çağıl Gökdoğan
- Department of Audiology, Ankara Gazi University Hospital, Ankara, Turkey
| | - Serkan Ünlü
- Pharmacology Department, Ankara Gazi University Institute of Health Sciences, Ankara, Turkey
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10
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Hankey GJ. B vitamins for stroke prevention. Stroke Vasc Neurol 2018; 3:51-58. [PMID: 30022794 PMCID: PMC6047336 DOI: 10.1136/svn-2018-000156] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/11/2018] [Accepted: 05/11/2018] [Indexed: 12/24/2022] Open
Abstract
Supplementation with B vitamins (vitamin B9(folic acid), vitamin B12 and vitamin B6) lowers blood total homocysteine (tHcy) concentrations by about 25% and reduces the relative risk of stroke overall by about 10% (risk ratio (RR) 0.90, 95% CI 0.82 to 0.99) compared with placebo. Homocysteine-lowering interventions have no significant effect on myocardial infarction, death from any cause or adverse outcomes. Factors that appear to modify the effect of B vitamins on stroke risk include low folic acid status, high tHcy, high cyanocobalamin dose in patients with impaired renal function and concurrent antiplatelet therapy. In regions with increasing levels or established policies of population folate supplementation, evidence from observational genetic epidemiological studies and randomised controlled clinical trials is concordant in suggesting an absence of benefit from lowering of homocysteine with folic acid for prevention of stroke. Clinical trials indicate that in countries which mandate folic acid fortification of food, folic acid supplementation has no significant effect on reducing stroke risk (RR 1.05, 95% CI 0.90 to 1.23). However, in countries without mandatory folic acid food fortification, folic acid supplementation reduces the risk of stroke by about 15% (RR 0.85, 95% CI 0.77 to 0.94). Folic acid alone or in combination with minimal cyanocobalamin (≤0.05 mg/day) is associated with an even greater reduction in risk of future stroke by 25% (RR 0.75, 95% CI 0.66 to 0.86), whereas the combination of folic acid and a higher dose of cyanocobalamin (≥0.4 mg/day) is not associated with a reduced risk of future stroke (RR 0.95, 95% CI 0.86 to 1.05). The lack of benefit of folic acid plus higher doses of cyanocobalamin (≥0.4 mg/day) was observed in trials which all included participants with chronic kidney disease. Because metabolic B12 deficiency is very common and usually not diagnosed, future randomised trials of homocysteine-lowering interventions for stroke prevention should probably test a combination of folic acid and methylcobalamin or hydroxocobalamin instead of cyanocobalamin, and perhaps vitamin B6.
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Affiliation(s)
- Graeme J Hankey
- UWA Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia.,Department of Neurology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
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11
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Lorenzini M, Guha N, Davison JE, Pitcher A, Pandya B, Kemp H, Lachmann R, Elliott PM, Murphy E. Isolated aortic root dilation in homocystinuria. J Inherit Metab Dis 2018; 41:109-115. [PMID: 28980096 PMCID: PMC5786652 DOI: 10.1007/s10545-017-0094-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 08/17/2017] [Accepted: 09/15/2017] [Indexed: 01/02/2023]
Abstract
BACKGROUND Vascular complications in homocystinuria have been known for many years, but there have been no reports to date on involvement of the ascending aorta. METHODS We conducted a cross-sectional study of patients with homocystinuria, known to a single metabolic centre, and evaluated in 2016 with a transthoracic echocardiogram. Aortic root dilation was defined as Z-score ≥ 2.0 SD, and graded mild (Z-score 2.0-3.0), moderate (Z-score 3.01-4.0) and severe (Z-score > 4.0). RESULTS The study population included 34 patients, median age of 44.3 years (IQR 33.3-52.2), 50% males, 69% diagnosed aged <18 years and 29% pyridoxine-responsive. Eight (24%) had a history of hypertension. Seven patients (21%) were found to have a dilation of the aortic root, mild in two cases (6%), moderate in four (12%) and severe in one (3%). None had dilation of the ascending aorta. Significant aortic regurgitation, secondary to moderate aortic root dilation, was documented in two patients. A single patient had significant mitral regurgitation due to prolapse of both valve leaflets, as well as mild aortic root dilation. Comparing patients with a dilation of the aortic root to those without, there were no significant clinical, laboratory or echocardiographic differences, with the only exception being that the diameter of the ascending aorta was larger in the group with a dilated aortic root, albeit within normal limits. CONCLUSIONS A subset of patients with homocystinuria have isolated dilation of the aortic root similar to that observed in Marfan syndrome.
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Affiliation(s)
- Massimiliano Lorenzini
- University College London Institute for Cardiovascular Science and Barts Heart Centre, St. Bartholomew's Hospital, London, UK
- Cardiology, Department of Experimental, Diagnostic and Specialty Medicine, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Nishan Guha
- Department of Clinical Biochemistry, John Radcliffe Hospital and Nuffield Division of Clinical Laboratory Sciences, University of Oxford, Oxford, UK
| | - James E Davison
- Metabolic Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Alex Pitcher
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Bejal Pandya
- Adult Congenital Heart Disease Department, Barts Heart Centre, St. Bartholomew's Hospital, London, UK
| | - Helena Kemp
- Department of Clinical Biochemistry, North Bristol NHS Trust, Bristol, UK
| | - Robin Lachmann
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Perry M Elliott
- University College London Institute for Cardiovascular Science and Barts Heart Centre, St. Bartholomew's Hospital, London, UK
| | - Elaine Murphy
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
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12
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Majtan T, Hůlková H, Park I, Krijt J, Kožich V, Bublil EM, Kraus JP. Enzyme replacement prevents neonatal death, liver damage, and osteoporosis in murine homocystinuria. FASEB J 2017; 31:5495-5506. [PMID: 28821635 DOI: 10.1096/fj.201700565r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 07/31/2017] [Indexed: 11/11/2022]
Abstract
Classical homocystinuria (HCU) is an inborn error of sulfur amino acid metabolism caused by deficient activity of cystathionine β-synthase (CBS), resulting in an accumulation of homocysteine and a concomitant decrease of cystathionine and cysteine in blood and tissues. In mice, the complete lack of CBS is neonatally lethal. In this study, newborn CBS-knockout (KO) mice were treated with recombinant polyethyleneglycolylated human truncated CBS (PEG-CBS). Full survival of the treated KO mice, along with a positive impact on metabolite levels in plasma, liver, brain, and kidneys, was observed. The PEG-CBS treatment prevented an otherwise fatal liver disease characterized by steatosis, death of hepatocytes, and ultrastructural abnormalities of endoplasmic reticulum and mitochondria. Furthermore, treatment of the KO mice for 5 mo maintained the plasma metabolite balance and completely prevented osteoporosis and changes in body composition that characterize both the KO model and human patients. These findings argue that early treatment of patients with HCU with PEG-CBS may prevent clinical symptoms of the disease possibly without the need of dietary protein restriction.-Majtan, T., Hůlková, H., Park, I., Krijt, J., Kožich, V., Bublil, E. M., Kraus, J. P. Enzyme replacement prevents neonatal death, liver damage, and osteoporosis in murine homocystinuria.
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Affiliation(s)
- Tomas Majtan
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA;
| | - Helena Hůlková
- Institute of Inherited Metabolic Disorders, Charles University-First Faculty of Medicine and General University Hospital, Prague, Czech Republic.,Institute of Pathology, Charles University-First Faculty of Medicine and General University Hospital, Prague, Czech Republic; and
| | - Insun Park
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Jakub Krijt
- Institute of Inherited Metabolic Disorders, Charles University-First Faculty of Medicine and General University Hospital, Prague, Czech Republic
| | - Viktor Kožich
- Institute of Inherited Metabolic Disorders, Charles University-First Faculty of Medicine and General University Hospital, Prague, Czech Republic
| | - Erez M Bublil
- Orphan Technologies Limited, Rapperswil, Switzerland
| | - Jan P Kraus
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA;
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Oxidative Stress in Homocystinuria Due to Cystathionine ß-Synthase Deficiency: Findings in Patients and in Animal Models. Cell Mol Neurobiol 2017; 37:1477-1485. [PMID: 28258516 DOI: 10.1007/s10571-017-0478-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 02/21/2017] [Indexed: 12/13/2022]
Abstract
Homocystinuria is an inborn error of amino acid metabolism caused by deficiency of cystathionine ß-synthase (CBS) activity, biochemically characterized by homocysteine (Hcy) and methionine (Met) accumulation in biological fluids and high urinary excretion of homocystine. Clinical manifestations include thinning and lengthening of long bones, osteoporosis, dislocation of the ocular lens, thromboembolism, and mental retardation. Although the pathophysiology of this disease is poorly known, the present review summarizes the available experimental findings obtained from patients and animal models indicating that oxidative stress may contribute to the pathogenesis of homocystinuria. In this scenario, several studies have shown that enzymatic and non-enzymatic antioxidant defenses are decreased in individuals affected by this disease. Furthermore, markers of lipid, protein, and DNA oxidative damage have been reported to be increased in blood, brain, liver, and skeletal muscle in animal models studied and in homocystinuric patients, probably as a result of increased free radical generation. On the other hand, in vitro and in vivo studies have shown that Hcy induces reactive species formation in brain, so that this major accumulating metabolite may underlie the oxidative damage observed in the animal model and human condition. Taken together, it may be presumed that the disruption of redox homeostasis may contribute to the tissue damage found in homocystinuria. Therefore, it is proposed that the use of appropriate antioxidants may represent a novel adjuvant therapy for patients affected by this disease.
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14
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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: 191] [Impact Index Per Article: 27.3] [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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15
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Homocysteine and disease: Causal associations or epiphenomenons? Mol Aspects Med 2016; 53:36-42. [PMID: 27876556 DOI: 10.1016/j.mam.2016.11.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 11/18/2016] [Indexed: 01/08/2023]
Abstract
Nutritional and genetic deficiencies of folate and vitamin B12 lead to elevation of cellular homocysteine (Hcy), which translates in increased plasma Hcy. The sources and role of elevated plasma Hcy in pathology continues to be a subject of intense scientific debate. Whether a cause, mediator or marker, little is known about the molecular mechanisms and interactions of Hcy with cellular processes that lead to disease. The use of folic acid reduces the incidence of neural tube defects, but the effect of Hcy-lowering interventions with folic acid in cardiovascular disease and cognitive impairment remains controversial. The fact that levels of Hcy in plasma do not always reflect cellular status of this amino acid may account for the substantial gaps that exist between epidemiological, intervention and basic research studies. Understanding whether plasma Hcy is a mechanistic player or an epiphenomenon in pathogenesis requires further investigation, and this research is essential to improve the assessment and potential treatment of hyperhomocysteinemias.
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16
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Jamison RL, Hartigan P, Gaziano JM, Fortmann SP, Goldfarb DS, Haroldson JA, Kaufman J, Lavori P, McCully KS, Robinson K. Design and statistical issues in the homocysteinemia in kidney and end stage renal disease (HOST) study. Clin Trials 2016; 1:451-60. [PMID: 16279283 DOI: 10.1191/1740774504cn038oa] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The Homocysteine Study (HOST) Veterans Affairs Cooperative Studies Program No. 453, is a prospective, randomized, two arm, double blind study of patients with end stage renal disease (ESRD) or advanced chronic kidney disease (ACKD, defined as an estimated creatinine clearance of 30 ml/min or less). Its primary objective is to determine whether administration of high doses of three vitamins, folic acid, vitamin B6 and vitamin B12, to lower the high plasma homocysteine levels, will reduce all cause mortality. The secondary objectives are to examine whether the treatment lowers the incidence of myocardial infarction, stroke, amputation of a lower extremity, a composite of death and the foregoing three events, the plasma homocysteine level, and, in ESRD patients undergoing hemodialysis, thrombosis of the vascular access. A unique feature of this trial is that after initial evaluation at enrollment and one return visit the follow up is exclusively by phone (or, if necessary, by mail). The subject is contacted every three months throughout the duration of the study from a central location. The study drug is shipped to the patient from a central location rather supplied locally. In a two year enrollment period, 2006 patients are to be enrolled. The duration of the observation period is four to six years. Data will be stored and analyzed at a coordinating center. The study design has the power to detect a reduction in all cause mortality rate of 17%. Issues related to the unique features of the design of this study are discussed.
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Affiliation(s)
- Rex L Jamison
- Division of Nephrology, Stanford University School of Medicine, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA
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17
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Sim WC, Han I, Lee W, Choi YJ, Lee KY, Kim DG, Jung SH, Oh SH, Lee BH. Inhibition of homocysteine-induced endoplasmic reticulum stress and endothelial cell damage by l-serine and glycine. Toxicol In Vitro 2016; 34:138-145. [DOI: 10.1016/j.tiv.2016.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 03/08/2016] [Accepted: 04/05/2016] [Indexed: 10/22/2022]
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18
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Sørensen JT, Gaustadnes M, Stabler SP, Allen RH, Mudd SH, Hvas AM. Molecular and biochemical investigations of patients with intermediate or severe hyperhomocysteinemia. Mol Genet Metab 2016; 117:344-50. [PMID: 26750749 DOI: 10.1016/j.ymgme.2015.12.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Revised: 12/22/2015] [Accepted: 12/22/2015] [Indexed: 10/22/2022]
Abstract
A discrepancy has been identified between numbers of expected and identified patients with homocystinuria due to cystathionine beta-synthase (CBS) deficiency. Patients homozygous for the frequent c.833T>C (p.I278T) are most often responsive to vitamin B6, and can present with a total-homocysteine (tHcy) <100 μM on a normal diet. In Denmark, patients with tHcy <100 μM are not routinely sequenced for CBS(2) mutations. This study investigated the prevalence of CBS mutations and the common methylenetetrahydrofolate reductase (MTHFR) c.677C>T polymorphism in patients with tHcy ≥ 50 μM and the association with clinical manifestations. We studied a cohort of patients with intermediate and severe hyperhomocysteinemia (tHcy ≥ 50 μM) determined between 1996 and 2011. Among the 413 eligible patients, 184 (45%) patients agreed to participate in the present follow-up study. A MTHFR(3)c.677TT genotype was found in 49% of the patients. Eight patients were found to have mutations in CBS(2). Of those, two were homozygous for c.833T>C (p.I278T), and four were compound heterozygous for c.833T>C. One c.833T>C (p.I278T) compound heterozygote was identified by lowering the threshold for sequencing from tHcy at 100 μM to 50 μM. The most prominent clinical presentation among patients with a CBS(2) mutation was thrombosis presenting at a median age of 25 years. In case of arterial or venous thrombosis without any explanation in individuals below 40 years, tHcy should be part of the thrombophilia screening. When tHcy is between 50 and 100 μM genotyping for the MTHFR(3) c.677TT is relevant, and when tHcy >100 μM CBS should be genotyped.
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Affiliation(s)
- Jannie Tanderup Sørensen
- Centre for Haemophilia and Thrombosis, Department of Clinical Biochemistry Aarhus University Hospital, Denmark
| | - Mette Gaustadnes
- Department of Molecular Medicine, Aarhus University Hospital, Denmark
| | - Sally P Stabler
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, USA
| | - Robert H Allen
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, USA
| | - S Harvey Mudd
- Laboratory of Molecular Biology, National Institute of Mental Health, NIH, Bethesda, USA
| | - Anne-Mette Hvas
- Centre for Haemophilia and Thrombosis, Department of Clinical Biochemistry Aarhus University Hospital, Denmark.
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19
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Borges MC, Hartwig FP, Oliveira IO, Horta BL. Is there a causal role for homocysteine concentration in blood pressure? A Mendelian randomization study. Am J Clin Nutr 2016; 103:39-49. [PMID: 26675774 PMCID: PMC4691668 DOI: 10.3945/ajcn.115.116038] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 10/28/2015] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND An understanding of whether homocysteine is a cause or a marker of increased blood pressure is relevant because blood homocysteine can be effectively lowered by safe and inexpensive interventions (e.g., vitamin B-6, B-9, and B-12 supplementation). OBJECTIVE The aim was to assess the causal influence of homocysteine on systolic and diastolic blood pressure (SBP and DBP, respectively) in adults with the use of Mendelian randomization (MR). DESIGN Data from the 1982 Pelotas Birth Cohort (Brazil) were used. A total of 4297 subjects were evaluated in 2004-2005 (mean age: 22.8 y). The association of homocysteine concentration with SBP and DBP was assessed by conventional ordinary least-squares (OLS) linear regression and 2-stage least-squares (2SLS) regression (MR analysis). The single nucleotide polymorphism (SNP) methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133) was used as proxy for homocysteine concentration. We also applied MR to data from the International Consortium for Blood Pressure (ICBP) genomewide association studies (>69,000 participants) using rs1801133 and additional homocysteine-associated SNPs as instruments. RESULTS In OLS regression, a 1-SD unit increase in log homocysteine concentration was associated with an increase of 0.9 (95% CI: 0.4, 1.4) mm Hg in SBP and of 1.0 (95% CI: 0.6, 1.4) mm Hg in DBP. In 2SLS regression, for the same increase in homocysteine, the coefficients were -1.8 mm Hg for SBP (95% CI: -3.9, 0.4 mm Hg; P = 0.01) and 0.1 mm Hg for DBP (95% CI: -1.5, 1.7 mm Hg; P = 0.24). In the MR analysis of ICBP data, homocysteine concentration was not associated with SBP (β = 0.6 mm Hg for each 1-SD unit increase in log homocysteine; 95% CI: -0.8, 1.9 mm Hg) but was positively associated with DBP (β = 1.1 mm Hg; 95% CI: 0.2, 1.9 mm Hg). The association of genetically increased homocysteine with DBP was not consistent across different SNPs. CONCLUSION Overall, the present findings do not corroborate the hypothesis that homocysteine has a causal role in blood pressure, especially in SBP.
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Affiliation(s)
| | | | - Isabel O Oliveira
- Postgraduate Program in Epidemiology and Department of Physiology and Pharmacology, Institute of Biology, Universidade Federal de Pelotas, Pelotas, Brazil
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20
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Brunelli S, Fusco A, Iosa M, Ricciardi E, Traballesi M. Functional Outcome After Lower Limb Amputation: Is Hyperhomocysteinemia a Predictive Factor?: An Observational Study. Medicine (Baltimore) 2015; 94:e2167. [PMID: 26656344 PMCID: PMC5008489 DOI: 10.1097/md.0000000000002167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Lower limb amputation (LLA) is the drastic stage of peripheral arterial disease (PAD) where the hyperhomocysteinemia (H-HCY) seems to be a risk factor. Surprisingly, in literature the levels and the role of homocysteinemia (HCY) in persons with LLA are understudied. This study aims to investigate the level of HCY and its correlation with the functional outcomes after LLA.A case-control study to analyze HCY levels in amputees admitted in a rehabilitation hospital during an investigation period of 1.5 years. Barthel Index was used to assess the functional outcome.We enrolled 91 dysvascular amputees and 44 amputees for other reasons than PAD (controls). The mean level of HCY was found higher in dysvascular amputees (15.2 ± 7.5) compared to controls (11.0 ± 5.0, P < 0.0001) with a risk related ratio of 4.78. Normal Gaussian distribution of HCY was observed in controls, whereas in dysvascular amputees the data follow a double Gaussian distribution. Finally, a significant negative correlation was found between HCY and the effectiveness of rehabilitation (R = -0.37, P = 0.001) only in dysvascular amputees.Dysvascular amputees had a level of HCY significantly higher than amputees without PAD. H-HCY seems to influence the functional outcomes of the rehabilitative treatment only in LLA due to PAD.
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Affiliation(s)
- Stefano Brunelli
- From the Santa Lucia Foundation, Scientific Institute for Research, Hospitalization and Health Care, Rome, Italy
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21
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Xie D, Yuan Y, Guo J, Yang S, Xu X, Wang Q, Li Y, Qin X, Tang G, Huo Y, Deng G, Wu S, Wang B, Zhang Q, Wang X, Fang P, Wang H, Xu X, Hou F. Hyperhomocysteinemia predicts renal function decline: a prospective study in hypertensive adults. Sci Rep 2015; 5:16268. [PMID: 26553372 PMCID: PMC4639775 DOI: 10.1038/srep16268] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 08/28/2015] [Indexed: 01/29/2023] Open
Abstract
Hyper-homocysteinemia (HHcy) is associated with microalbuminuria and glomerular injury in general and diabetic populations. However, HHcy’s role in hypertensive patients was not studied. We investigated whether HHcy is an independent risk factor for renal function decline and development of chronic kidney disease (CKD) in hypertensive men and women. This was a community-based prospective cohort study of 2,387 hypertensive adults without CKD at baseline, with a mean follow-up of 4.4 years. Baseline and follow-up levels of plasma Hcy, folate, vitamin B12, blood pressure and other pertinent covariables were obtained. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/per 1.73 m2 and an eGFR decline rate >1 ml/min/per 1.73 m2/year. There was a graded association between Hcy tertiles and eGFR decline. Subjects in the 3rd tertile of Hcy levels had an accelerated rate of eGFR decline and an increased risk of incident CKD, as compared with those in the 1st tertile, after adjusting for age, gender, baseline diabetes, SBP, BMI, smoking, dyslipidemia, eGFR, folate and vitamin B12 levels. In conclusion, in this prospective cohort of Chinese hypertensive adults, elevated baseline plasma Hcy can serve as an independent biomarker to predict renal function decline and incident CKD.
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Affiliation(s)
- Di Xie
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yan Yuan
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jiangnan Guo
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Shenglin Yang
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xin Xu
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Qin Wang
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Youbao Li
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xianhui Qin
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Genfu Tang
- School of Health Administration, Anhui Medical University, Hefei, China
| | - Yong Huo
- Department of Cardiology, Peking University First Hospital, Beijing, China
| | - Guangpu Deng
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Shengjie Wu
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Binyan Wang
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,Institute of Biomedicine, Anhui Medical University, Hefei, China
| | - Qin Zhang
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xiaobin Wang
- Department of Population, Family and Reproductive Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, USA
| | - Pu Fang
- Department of Pharmacology, Center for Metabolic Disease Research, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Hong Wang
- Department of Pharmacology, Center for Metabolic Disease Research, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Xiping Xu
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Fanfan Hou
- National Clinical Research Center of Kidney Disease, State Key Laboratory of Organ Failure Research, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China
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22
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Latour A, Salameh S, Carbonne C, Daubigney F, Paul JL, Kergoat M, Autier V, Delabar JM, De Geest B, Janel N. Corrective effects of hepatotoxicity by hepatic Dyrk1a gene delivery in mice with intermediate hyperhomocysteinemia. Mol Genet Metab Rep 2015. [PMID: 28649528 PMCID: PMC5471159 DOI: 10.1016/j.ymgmr.2014.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Hyperhomocysteinemia results from hepatic metabolism dysfunction and is characterized by a high plasma homocysteine level, which is also an independent risk factor for cardiovascular disease. Elevated levels of homocysteine in plasma lead to hepatic lesions and abnormal lipid metabolism. Therefore, lowering homocysteine levels might offer therapeutic benefits. Recently, we were able to lower plasma homocysteine levels in mice with moderate hyperhomocysteinemia using an adenoviral construct designed to restrict the expression of DYRK1A, a serine/threonine kinase involved in methionine metabolism (and therefore homocysteine production), to hepatocytes. Here, we aimed to extend our previous findings by analyzing the effect of hepatocyte-specific Dyrk1a gene transfer on intermediate hyperhomocysteinemia and its associated hepatic toxicity and liver dysfunction. Commensurate with decreased plasma homocysteine and alanine aminotransferase levels, targeted hepatic expression of DYRK1A in mice with intermediate hyperhomocysteinemia resulted in elevated plasma paraoxonase-1 and lecithin:cholesterol acyltransferase activities and apolipoprotein A-I levels. It also rescued hepatic apolipoprotein E, J, and D levels. Further, Akt/GSK3/cyclin D1 signaling pathways in the liver of treated mice were altered, which may help prevent homocysteine-induced cell cycle dysfunction. DYRK1A gene therapy could be useful in the treatment of hyperhomocysteinemia in populations, such as end-stage renal disease patients, who are unresponsive to B-complex vitamin therapy.
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Key Words
- ALT, alanine aminotransferase
- APO, apolipoprotein
- Alanine aminotransferase
- Apolipoproteins
- CBS, cystathionine beta synthase
- DCPIP, 2,6-dichlorophenolindophenol
- Dyrk1a gene transfer
- HDLs, high-density lipoproteins
- HPLC, high-performance liquid chromatography
- Intermediate hyperhomocysteinemia
- KYNA, kynurenic acid
- LCAT, lecithin:cholesterol acyltransferase
- Lecithin:cholesterol acyltransferase
- Mice
- NQO1, NAD(P)H:quinone oxidoreductase
- PBS, phosphate-buffered saline
- PCR, polymerase chain reaction
- PON-1, paraoxonase-1
- SAH, S-adenosylhomocysteine
- SAHH, S-adenosylhomocysteine hydrolase
- SAM, S-adenosylmethionine
- VLDL, very low-density lipoprotein.
- hcy, homocysteine
- hhcy, hyperhomocysteinemia
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Affiliation(s)
- Alizée Latour
- Univ Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative (BFA), UMR 8251 CNRS, F-75205 Paris, France
| | - Sacha Salameh
- Univ Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative (BFA), UMR 8251 CNRS, F-75205 Paris, France
| | - Christel Carbonne
- Metabrain Research, Chilly Mazarin, France.,Brain & Spine Institute (ICM) CNRS UMR7225, INSERM UMRS 975, Paris, France
| | - Fabrice Daubigney
- Univ Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative (BFA), UMR 8251 CNRS, F-75205 Paris, France
| | - Jean-Louis Paul
- AP-HP, Hôpital Européen Georges Pompidou, Service de Biochimie, 75015 Paris, France.,Univ Paris-Sud, EA 4529, UFR de Pharmacie, 92296 Châtenay-Malabry, France
| | - Micheline Kergoat
- Metabrain Research, Chilly Mazarin, France.,Brain & Spine Institute (ICM) CNRS UMR7225, INSERM UMRS 975, Paris, France
| | - Valérie Autier
- Metabrain Research, Chilly Mazarin, France.,Brain & Spine Institute (ICM) CNRS UMR7225, INSERM UMRS 975, Paris, France
| | - Jean-Maurice Delabar
- Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Bart De Geest
- Center for Molecular and Vascular Biology, University of Leuven, Campus Gasthuisberg, 3000 Leuven, Belgium
| | - Nathalie Janel
- Univ Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative (BFA), UMR 8251 CNRS, F-75205 Paris, France
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23
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Poloni S, Leistner-Segal S, Bandeira IC, D'Almeida V, de Souza CFM, Spritzer PM, Castro K, Tonon T, Nalin T, Imbard A, Blom HJ, Schwartz IVD. Body composition in patients with classical homocystinuria: body mass relates to homocysteine and choline metabolism. Gene 2014; 546:443-7. [PMID: 24815046 DOI: 10.1016/j.gene.2014.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 04/20/2014] [Accepted: 05/05/2014] [Indexed: 01/10/2023]
Abstract
INTRODUCTION Classical homocystinuria is a rare genetic disease caused by cystathionine β-synthase deficiency, resulting in homocysteine accumulation. Growing evidence suggests that reduced fat mass in patients with classical homocystinuria may be associated with alterations in choline and homocysteine pathways. This study aimed to evaluate the body composition of patients with classical homocystinuria, identifying changes in body fat percentage and correlating findings with biochemical markers of homocysteine and choline pathways, lipoprotein levels and bone mineral density (BMD) T-scores. METHODS Nine patients with classical homocystinuria were included in the study. Levels of homocysteine, methionine, cysteine, choline, betaine, dimethylglycine and ethanolamine were determined. Body composition was assessed by bioelectrical impedance analysis (BIA) in patients and in 18 controls. Data on the last BMD measurement and lipoprotein profile were obtained from medical records. RESULTS Of 9 patients, 4 (44%) had a low body fat percentage, but no statistically significant differences were found between patients and controls. Homocysteine and methionine levels were negatively correlated with body mass index (BMI), while cysteine showed a positive correlation with BMI (p<0.05). There was a trend between total choline levels and body fat percentage (r=0.439, p=0.07). HDL cholesterol correlated with choline and ethanolamine levels (r=0.757, p=0.049; r=0.847, p=0.016, respectively), and total cholesterol also correlated with choline levels (r=0.775, p=0.041). There was no association between BMD T-scores and body composition. CONCLUSIONS These results suggest that reduced fat mass is common in patients with classical homocystinuria, and that alterations in homocysteine and choline pathways affect body mass and lipid metabolism.
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Affiliation(s)
- Soraia Poloni
- Post-Graduation Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; BRAIN Laboratory (Basic Research and Advanced Investigations in Neurosciences), Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
| | - Sandra Leistner-Segal
- BRAIN Laboratory (Basic Research and Advanced Investigations in Neurosciences), Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Isabel Cristina Bandeira
- BRAIN Laboratory (Basic Research and Advanced Investigations in Neurosciences), Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Vânia D'Almeida
- Reference Center for Inborn Errors of Metabolism, Universidade Federal de São Paulo, São Paulo, Brazil
| | | | - Poli Mara Spritzer
- Gynecological Endocrinology Unit, Division of Endocrinology, Hospital de Clinicas de Porto Alegre, Department of Physiology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Kamila Castro
- Food and Nutrition Research Center, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Tássia Tonon
- Post-Graduation Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Tatiéle Nalin
- Post-Graduation Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Apolline Imbard
- Biochemistry-Hormonology Laboratory, Robert Debré Hospital, APHP, Paris, France; Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, University Medical Centre Freiburg, Freiburg, Germany
| | - Henk J Blom
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, University Medical Centre Freiburg, Freiburg, Germany
| | - Ida V D Schwartz
- Post-Graduation Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; BRAIN Laboratory (Basic Research and Advanced Investigations in Neurosciences), Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
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24
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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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25
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Gupta S, Melnyk SB, Kruger WD. Cystathionine β-synthase-deficient mice thrive on a low-methionine diet. FASEB J 2013; 28:781-90. [PMID: 24189943 DOI: 10.1096/fj.13-240770] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cystathionine β-synthase (CBS) deficiency is a recessive inborn error of metabolism characterized by elevated serum total homocysteine (tHcy). Previously, our laboratory developed a mouse model of CBS deficiency, TgI278T Cbs(-)/(-) (abbreviated as Cbs(-/-)), characterized by low weight, low adiposity, decreased Scd-1 expression, facial alopecia, and osteoporosis. To determine the potential benefit of a methionine-restricted diet (MRD), we fed Cbs(-/-) and Cbs(+/-) control mice either an MRD or a regular diet (RD) from weaning till 240 d of age. Cbs(-/-) mice fed the MRD had a 77% decrease in tHcy, 28% increase in weight, 130% increase in fat mass, 82% increase in Scd-1 expression, and 10.6% increase in bone density and entirely lacked the alopecia phenotype observed in age-matched Cbs(-/-) mice fed the RD. At the end of the study, Cbs(-/-) mice fed the MRD were phenotypically indistinguishable from Cbs(+/-) mice fed the RD. Notably, whereas the MRD diet was highly beneficial to Cbs(-/-) mice, it had nearly opposite effect on Cbs(+/-) mice. These studies show that a low-methionine diet can correct the phenotypic consequences of loss of CBS and provide a striking example of how genotype and diet can interact to influence phenotype in mammals.
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Affiliation(s)
- Sapna Gupta
- 1Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111, USA.
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26
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Pey AL. Protein homeostasis disorders of key enzymes of amino acids metabolism: mutation-induced protein kinetic destabilization and new therapeutic strategies. Amino Acids 2013; 45:1331-41. [PMID: 24178766 DOI: 10.1007/s00726-013-1609-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 10/19/2013] [Indexed: 12/31/2022]
Abstract
Many inborn errors of amino acids metabolism are caused by single point mutations affecting the ability of proteins to fold properly (i.e., protein homeostasis), thus leading to enzyme loss-of-function. Mutations may affect protein homeostasis by altering intrinsic physical properties of the polypeptide (folding thermodynamics, and rates of folding/unfolding/misfolding) as well as the interaction of partially folded states with elements of the protein homeostasis network (such as molecular chaperones and proteolytic machineries). Understanding these mutational effects on protein homeostasis is required to develop new therapeutic strategies aimed to target specific features of the mutant polypeptide. Here, I review recent work in three different diseases of protein homeostasis associated to inborn errors of amino acids metabolism: phenylketonuria, inherited homocystinuria and primary hyperoxaluria type I. These three different genetic disorders involve proteins operating in different cell organelles and displaying different structural complexities. Mutations often decrease protein kinetic stability of the native state (i.e., its half-life for irreversible denaturation), which can be studied using simple kinetic models amenable to biophysical and biochemical characterization. Natural ligands and pharmacological chaperones are shown to stabilize mutant enzymes, thus supporting their therapeutic application to overcome protein kinetic destabilization. The role of molecular chaperones in protein folding and misfolding is also discussed as well as their potential pharmacological modulation as promising new therapeutic approaches. Since current available treatments for these diseases are either burdening or only successful in a fraction of patients, alternative treatments must be considered covering studies from protein structure and biophysics to studies in animal models and patients.
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Affiliation(s)
- Angel L Pey
- Department of Physical Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, 18071, Granada, Spain,
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27
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Evaluation of the prevalence of severe hyperhomocysteinemia in adult patients with thrombosis who underwent screening for thrombophilia. Thromb Res 2013; 132:681-4. [PMID: 24168815 DOI: 10.1016/j.thromres.2013.09.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 09/26/2013] [Accepted: 09/30/2013] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Treatment with B-vitamins and betaine reduces the high risk of thrombosis in patients with homocystinuria, a metabolic syndrome that is characterized by severe hyperhomocysteinemia (HHcy). In contrast, there is no clear demonstration that B-vitamins reduce the risk of thrombosis in patients with mild HHcy: for this reason, many question the clinical utility of measuring total Hcy (tHcy) in patients with thrombosis. However, thrombosis may be the first clinical manifestation of homocystinuria in patients reaching adulthood without signs and symptoms of the syndrome. AIM 1) to measure the prevalence of severe, previously undiagnosed, HHcy among patients with thrombosis 2) to profile these patients on the basis of their characteristics. METHODS Six Italian Thrombosis Centers completed a first questionnaire, reporting tHcy levels in patients with thrombosis who underwent thrombophilia screening, and a second questionnaire, reporting the characteristics of patients with severe HHcy (tHcy>100μmol/L). RESULTS Of 19,678 cross-sectionally collected patients with thrombosis who underwent thrombophilia screening in the last 12.5years (median value, range 6-17), 38 had severe HHcy (0.2%). Their median age at diagnosis was 47years (range 19-83) and the median level of tHcy was 130μmol/L (range 101-262). Venous thromboembolism (71%) was more frequent than arterial thromboembolism (26%); recurrent thrombosis occurred in 42% of cases. CONCLUSIONS Measurement of tHcy in adult patients with thrombosis may reveal the presence of severe HHcy. Since treatment of patients with severe HHcy decreases the risk of thrombosis, measurement of tHcy in patients with thrombosis may prove clinically useful.
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28
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Gupta S, Wang L, Anderl J, Slifker MJ, Kirk C, Kruger WD. Correction of cystathionine β-synthase deficiency in mice by treatment with proteasome inhibitors. Hum Mutat 2013; 34:1085-93. [PMID: 23592311 DOI: 10.1002/humu.22335] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/25/2013] [Accepted: 03/28/2013] [Indexed: 12/21/2022]
Abstract
Cystathionine beta-synthase (CBS) deficiency is an inborn error of metabolism characterized by extremely elevated levels of plasma total homocysteine. The vast majority of CBS-deficient patients have missense mutations located in the CBS gene that result in the production of either misfolded or unstable protein. Here, we examine the effect of proteasome inhibitors on mutant CBS function using two different mouse models of CBS deficiency. These mice lack mouse CBS and express a missense mutant human CBS enzyme (either p.I278T or p.S466L) that has less than 5% of normal liver CBS activity, resulting in a 10-30-fold elevation in plasma homocysteine levels. We show that treatment of these mice with two different proteasome inhibitors can induce liver Hsp70, Hsp40, and Hsp27, increase levels of active CBS, and lower plasma homocysteine levels to within the normal range. However, response rates varied, with 100% (8/8) of the p.S466L animals showing correction, but only 38% (10/26) of the p.I278T animals. In total, our data show that treatment with proteostasis modulators can restore significant enzymatic activity to mutant misfolded CBS enzymes and suggests that they may be useful in treating certain types of genetic diseases caused by missense mutations.
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Affiliation(s)
- Sapna Gupta
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA
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29
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Association between B-group vitamins and venous thrombosis: systematic review and meta-analysis of epidemiological studies. J Thromb Thrombolysis 2013; 34:459-67. [PMID: 22743781 DOI: 10.1007/s11239-012-0759-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A homocysteine-independent role for B-group vitamins on venous thrombosis (VT) development has been reported. However, related research findings remain inconsistent. PUBMED, EMBASE, and COCHRANE databases were searched to collect information on all eligible studies to make a meta-analysis about the relationship between B-group vitamins and VT. Literature search results did not suggest a correlation between thiamin, pantothenic acid, niacin, or riboflavin with VT. Based on their correlations in the literature, folic acid, vitamin B12, B6 were considered in the meta-analysis and systematic review. Significant standardized mean differences were obtained for plasma folic acid (-0.55; 95% CI, -0.75 to -0.36) and vitamin B12 (-0.34; 95% CI, -0.55 to -0.13). Reduced levels of folic acid and vitamin B12 may be independent risk factors of VT. Moreover, a qualitative systematic review indicated that low level of vitamin B6 was an independent risk factor of VT. Randomized clinical studies of B-group vitamins supplementation showed varying results on VT prevention. Multivitamin supplementation for VT prevention, regardless of homocysteine level, would be of interest. Further prospective clinical studies are needed to provide additional evidence on the clinical benefits of B-group vitamin supplementation for VT.
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30
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Yang HT, Lee M, Hong KS, Ovbiagele B, Saver JL. Efficacy of folic acid supplementation in cardiovascular disease prevention: an updated meta-analysis of randomized controlled trials. Eur J Intern Med 2012; 23:745-54. [PMID: 22884409 DOI: 10.1016/j.ejim.2012.07.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 06/28/2012] [Accepted: 07/03/2012] [Indexed: 10/28/2022]
Abstract
BACKGROUND In observational studies, lower serum homocysteine levels are associated with a lower incidence of cardiovascular disease (CVD). However, individual randomized controlled trials (RCTs) have yielded mixed findings regarding the efficacy of therapeutic homocysteine in lowering cardiovascular risk. Our aim was to perform an updated meta-analysis of relevant RCTs to assess the efficacy of folic acid supplementation in the prevention of CVD, coronary heart disease (CHD), and stroke. METHODS We performed systematic search to identify RCTs reported at least one of the CVD, CHD, or stroke as outcomes. Relative risk (RR) with 95% confidence interval was used as a measure of the association between folic acid supplementation and risk of CVD, CHD, stroke, and all-cause mortality. The analysis was further stratified by factors that could affect the treatment effects. RESULTS The systematic search identified 26 RCTs enrolling 58,804 participants. Pooling the RRs showed that folic acid supplementation was not associated with any significant change in the risk of CVD (RR 0.98, 0.95 to 1.02; p=0.36), CHD (RR 1.03, 0.98 to 1.08; p=0.23), and all-cause mortality (RR 1.00, 0.96 to 1.04; p=0.92), but was linked to a decreasing trend in stroke risk (RR 0.93, 0.86 to 1.00; p=0.05). In stratified analyses, the only heterogeneity was found for stroke risk reduction among groups with (RR 1.07, 0.92 to 1.25) vs. without (RR 0.88, 0.81 to 0.96) mandatory grain fortification (P for heterogeneity=0.03). CONCLUSIONS This meta-analysis suggests that there might be a potentially modest benefit of folic acid supplementation in stroke prevention.
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Affiliation(s)
- Hsin-Ta Yang
- Department of Neurology, Chang Gung Memorial Hospital at Chiayi, Chang Gung University College of Medicine, Taiwan
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31
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Ukachukwu V, Idris S, McIlwee A. Acute myocardial infarction in a young patient with hyperhomocysteinaemia. BMJ Case Rep 2012; 2012:bcr-2012-007489. [PMID: 23144358 DOI: 10.1136/bcr-2012-007489] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Homocysteinuria is a rare inborn error of metabolism known to be associated with an increased risk of vascular events. A 36-year-old Caucasian man presented with a 2 day history of epigastric discomfort associated with nausea and sweating. He has a history of homocysteinuria and had been poorly compliant with treatment. An ECG showed ST-segment elevation and Q-waves in anterior leads. Blood tests showed markedly elevated high-sensitivity troponin and high homocysteine levels. He had a failed primary percutaneous coronary intervention due to extensive thrombus in the left anterior descending artery, which was aspirated and he received integrelin infusion for 48 h. Echocardiogram showed mild-to-moderate impairment of left ventricular function with apical akinesis extending to the mid-portion of anteroseptal walls consistent with anterior myocardial infarction. He was started on homocysteine-lowering treatment with betaine and folic acid. He is now on follow-up with clinical chemistry and cardiac rehabilitation.
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32
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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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33
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Stanger O, Wonisch W. Enzymatic and non-enzymatic antioxidative effects of folic acid and its reduced derivates. Subcell Biochem 2012; 56:131-161. [PMID: 22116698 DOI: 10.1007/978-94-007-2199-9_8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A great part of the population appears to have insufficient folate intake, especially subgroups with higher demand, as determined through more sensitive methods and parameters currently in use. As the role of folate deficiency in congenital defects, e.g. in cardiovascular and neurodegenerative diseases, and in carcinogenesis has become better understood, folate has been recognized as having great potential to prevent these many disorders through folate supplementation or fortification for the general population. Folates are essential cofactors in the transfer and utilization of one-carbon groups in the process of DNA-biosynthesis with implications for genomic repair and stability. Folate acts indirectly to lower homocysteine levels and insures optimal functioning of the methylation cycle. Homocysteine was shown to be an independent risk factor for neurodegenerative and cardiovascular disease, which includes peripheral vascular disease, coronary artery disease, cerebrovascular disease and venous thrombosis. In fact, it was long believed that the beneficial effects of folate on vascular function and disease are related directly to the mechanism of homocysteine-diminution. Recent investigations have, however, demonstrated beneficial effects of folates unrelated to homocysteine-diminution, suggesting independent properties. One such mechanism could be free radical scavenging and antioxidant activity, as it is now recognized that free radicals play an important role in the oxidative stress leading to many diseases. It was found that folic acid and, in particular, its reduced derivates act both directly and indirectly to produce antioxidant effects. Folates interact with the endothelial enzyme NO synthase (eNOS) and, exert effects on the cofactor bioavailability of NO and thus, on peroxynitrite formation. Folate metabolism provides an interesting example of gene-environmental interaction.
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Affiliation(s)
- Olaf Stanger
- Heart Division, Cardiothoracic Surgery, Royal Brompton and Harefield NHS Foundation, Imperial College of Science, Technology and Medicine, Sydney Street, London, SW3 6NP, UK,
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34
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Vanzin CS, Biancini GB, Sitta A, Wayhs CAY, Pereira IN, Rockenbach F, Garcia SC, Wyse ATDS, Schwartz IVD, Wajner M, Vargas CR. Experimental evidence of oxidative stress in plasma of homocystinuric patients: a possible role for homocysteine. Mol Genet Metab 2011; 104:112-7. [PMID: 21742526 DOI: 10.1016/j.ymgme.2011.06.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 06/16/2011] [Accepted: 06/16/2011] [Indexed: 11/27/2022]
Abstract
Homocystinuria is an inherited disorder biochemically characterized by high urinary excretion of homocystine and increased levels of homocysteine (Hcy) and methionine in biological fluids. Affected patients usually have a variety of clinical and pathologic manifestations. Previous experimental data have shown a relationship between Hcy and oxidative stress, although very little was reported on this process in patients with homocystinuria. Therefore, in the present study we evaluated parameters of oxidative stress, namely carbonyl formation, malondialdehyde (MDA) levels, sulfhydryl content and total antioxidant status (TAS) in patients with homocystinuria at diagnosis and under treatment with a protein restricted diet supplemented by pyridoxine, folate, betaine, and vitamin B(12). We also correlated plasma Hcy and methionine concentrations with the oxidative stress parameters examined. We found a significant increase of MDA levels and carbonyl formation, as well as a reduction of sulfhydryl groups and TAS in plasma of homocystinuric patients at diagnosis relatively to healthy individuals (controls). We also verified that Hcy levels were negatively correlated with sulfhydryl content and positively with MDA levels. Furthermore, patients under treatment presented a significant reduction of the content of MDA, Hcy and methionine concentrations relatively to patients at diagnosis. Taken together, the present data indicate that lipid and protein oxidative damages are increased and the antioxidant defenses diminished in plasma of homocystinuric patients, probably due to increased reactive species elicited by Hcy. It is therefore presumed that oxidative stress participates at least in part in the pathogenesis of homocystinuria.
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Affiliation(s)
- Camila Simioni Vanzin
- Programa de Pós-Graduação em Ciências Biológicas:Bioquímica da Universidade Federal do Rio Grande do Sul (UFRGS), Ramiro Barcelos 2700, Porto Alegre, RS, 90035-000, Brazil
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35
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Garland J, Prasad A, Vardy C, Prasad C. Homocystinuria: Challenges in diagnosis and management. Paediatr Child Health 2011; 4:557-62. [PMID: 20213008 DOI: 10.1093/pch/4.8.557] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Two patients with homocystinuria are discussed. Both patients presented with behavioural abnormalities and deficits in attention - symptoms that are frequently encountered in paediatric office practice. In both cases, the diagnosis of homocystinuria was not made at initial presentation. Subtle but definite phenotypic features eventually provided the first indication of homocystinuria between the ages of five to seven years. Laboratory screening confirmed homocystine in the urine, and elevated methionine and homocysteine plasma levels in both patients. Patients with inborn errors of metabolism such as homocystinuria are treated first by family physicians and paediatricians. Without a high index of suspicion, physicians can easily overlook a diagnosis of homocystinuria. The management of patients with homocystinuria continues to pose a challenge to physicians and care givers.
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Cozar M, Urreizti R, Vilarinho L, Grosso C, Dodelson de Kremer R, Asteggiano CG, Dalmau J, García AM, Vilaseca MA, Grinberg D, Balcells S. Identification and functional analyses of CBS alleles in Spanish and Argentinian homocystinuric patients. Hum Mutat 2011; 32:835-42. [PMID: 21520339 DOI: 10.1002/humu.21514] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 04/04/2011] [Indexed: 11/08/2022]
Abstract
Homocystinuria due to CBS deficiency is a rare autosomal recessive disorder characterized by elevated plasma levels of homocysteine (Hcy) and methionine (Met). Here we present the analysis of 22 unrelated patients of different geographical origins, mainly Spanish and Argentinian. Twenty-two different mutations were found, 10 of which were novel. Five new mutations were missense and five were deletions of different sizes, including a 794-bp deletion (c.532-37_736 + 438del794) detected by Southern blot analysis. To assess the pathogenicity of these mutations, seven were expressed heterologously in Escherichia coli and their enzyme activities were assayed in vitro, in the absence and presence of the CBS activators PLP and SAM. The presence of the mutant proteins was confirmed by Western blotting. Mutations p.M173del, p.I278S, p.D281N, and p.D321V showed null activity in all conditions tested, whereas mutations p.49L, p.P200L and p.A446S retained different degrees of activity and response to stimulation. Finally, a minigene strategy allowed us to demonstrate the pathogenicity of an 8-bp intronic deletion, which led to the skipping of exon 6. In general, frameshifting deletions correlated with a more severe phenotype, consistent with the concept that missense mutations may recover enzymatic activity under certain conditions.
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Affiliation(s)
- Mónica Cozar
- Departament de Genètica, Universitat de Barcelona, IBUB, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Barcelona, Spain
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Schiff M, Benoist JF, Tilea B, Royer N, Giraudier S, Ogier de Baulny H. Isolated remethylation disorders: do our treatments benefit patients? J Inherit Metab Dis 2011; 34:137-45. [PMID: 20490923 DOI: 10.1007/s10545-010-9120-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 04/17/2010] [Accepted: 04/20/2010] [Indexed: 10/19/2022]
Abstract
Deficiency of 5,10-methylenetetrahydrofolate reductase (MTHFR), the very rare methionine synthase reductase (CblE) and methionine synthase (CblG) defects, and the recently identified CblD-variant-1 defect are primary remethylation defects characterized by an isolated defect in methionine synthesis without methylmalonic aciduria. The clinical signs are mainly neurological, and hematological signs are seen in CblE, CblG, and CblD-variant-1 defects. Patients with neonatal or early-onset disease exhibit acute neurological distress. Infants and children have unspecific mental retardation, often with acquired microcephaly. Without appropriate therapy, they may experience acute or rapidly progressive neurological deterioration, which may be fatal. Adolescents and adults show normal development or mild developmental delay initially and then experience rapid neurological or behavioral deterioration. A few patients may have signs of subacute combined degeneration of the spinal cord. Adults may be asymptomatic or present with isolated thromboembolism. All patients with suspected remethylation disorders should receive emergency treatment with parenteral administration of hydroxocobalamin and folate supplements combined with betaine orally. The long-term treatment of CblE, CblG, and CblD-variant-1 defects consists of parenterally administered hydroxocobalamin and orally administered folate and betaine supplements, whereas patients with MTHFR deficiency require long-term oral folate and betaine supplements. Long-term oral methionine therapy should also be considered. Early treatment may lead to a favorable outcome with developmental recovery and prevention of further neurological deterioration. In contrast, most late-treated patients have severe and irreversible neuromotor impairments. Hematological abnormalities are easily corrected.
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Affiliation(s)
- Manuel Schiff
- Reference Center for Metabolic Disease, Robert Debré University Hospital, Paris, France.
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McGarrigle SA, O’Neill S, Walsh GM, Moran N, Graham IM, Cooney MT, Monavari A, Mayne P, Collins P. IntegrinαIIbβ3exists in an activated state in subjects with elevated plasma homocysteine levels. Platelets 2010; 22:65-73. [DOI: 10.3109/09537104.2010.512646] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kirsch SH, Herrmann W, Rabagny Y, Obeid R. Quantification of acetylcholine, choline, betaine, and dimethylglycine in human plasma and urine using stable-isotope dilution ultra performance liquid chromatography–tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2010; 878:3338-44. [DOI: 10.1016/j.jchromb.2010.10.016] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Revised: 10/13/2010] [Accepted: 10/16/2010] [Indexed: 10/18/2022]
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Unverdorben M, von Holt K, Winkelmann BR. Smoking and atherosclerotic cardiovascular disease: part II: role of cigarette smoking in cardiovascular disease development. Biomark Med 2010; 3:617-53. [PMID: 20477529 DOI: 10.2217/bmm.09.51] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Potential mechanisms and biomarkers of atherosclerosis related to cigarette smoking - a modifiable risk factor for that disease - are discussed in this article. These include smoking-associated inflammatory markers, such as leukocytes, high-sensitivity C-reactive protein, serum amyloid A, ICAM-1 and IL-6. Other reviewed markers are indicative for smoking-related impairment of arterial endothelial function (transcapillary leakage of albumin, inhibition of endogenous nitric oxide synthase activity and reduced endothelium-dependent vasodilation) or point to oxidative stress caused by various chemicals (cholesterol oxidation, autoantibodies to oxidized low-density lipoprotein, plasma levels of malondialdehyde and F(2)-isoprostanes and reduced antioxidant capacity). Smoking enhances platelet aggregability, increases blood viscosity and shifts the pro- and antithrombotic balance towards increased coagulability (e.g., fibrinogen, von Willebrand factor, ICAM-1 and P-selectin). Insulin resistance is higher in smokers compared with nonsmokers, and hemoglobin A1c is dose-dependently elevated, as is homocysteine. Smoke exposure may influence the kinetics of markers with different response to transient or chronic changes in cigarette smoking behavior.
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Affiliation(s)
- Martin Unverdorben
- Clinical Research Institute, Center for Cardiovascular Diseases, Heinz-Meise-Strasse 100, 36199 Rotenburg an der Fulda, Germany.
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Singh LR, Gupta S, Honig NH, Kraus JP, Kruger WD. Activation of mutant enzyme function in vivo by proteasome inhibitors and treatments that induce Hsp70. PLoS Genet 2010; 6:e1000807. [PMID: 20066033 PMCID: PMC2795852 DOI: 10.1371/journal.pgen.1000807] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 12/09/2009] [Indexed: 01/30/2023] Open
Abstract
Missense mutant proteins, such as those produced in individuals with genetic diseases, are often misfolded and subject to processing by intracellular quality control systems. Previously, we have shown using a yeast system that enzymatic function could be restored to I278T cystathionine beta-synthase (CBS), a cause of homocystinuria, by treatments that affect the intracellular chaperone environment. Here, we extend these studies and show that it is possible to restore significant levels of enzyme activity to 17 of 18 (94%) disease causing missense mutations in human cystathionine beta-synthase (CBS) expressed in Saccharomyces cerevisiae by exposure to ethanol, proteasome inhibitors, or deletion of the Hsp26 small heat shock protein. All three of these treatments induce Hsp70, which is necessary but not sufficient for rescue. In addition to CBS, these same treatments can rescue disease-causing mutations in human p53 and the methylene tetrahydrofolate reductase gene. These findings do not appear restricted to S. cerevisiae, as proteasome inhibitors can restore significant CBS enzymatic activity to CBS alleles expressed in fibroblasts derived from homocystinuric patients and in a mouse model for homocystinuria that expresses human I278T CBS. These findings suggest that proteasome inhibitors and other Hsp70 inducing agents may be useful in the treatment of a variety of genetic diseases caused by missense mutations.
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Affiliation(s)
- Laishram R. Singh
- Cancer Genetics and Signaling Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Sapna Gupta
- Cancer Genetics and Signaling Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Nicholaas H. Honig
- Cancer Genetics and Signaling Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
| | - Jan P. Kraus
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Warren D. Kruger
- Cancer Genetics and Signaling Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
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Sottilotta G, Siboni SM, Latella C, Oriana V, Romeo E, Santoro R, Consonni D, Trapani Lombardo V. Hyperhomocysteinemia and C677T MTHFR genotype in patients with retinal vein thrombosis. Clin Appl Thromb Hemost 2009; 16:549-53. [PMID: 19825913 DOI: 10.1177/1076029609348644] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION Elevated homocysteine (Hcy) is associated with the risk of deep vein thrombosis, pulmonary embolism, ischemic heart disease, and stroke. Several studies have suggested that hyperhomocysteinemia (HHcy) may predispose to retinal vein thrombosis (RVT) development. The aim of this study is to investigate the relationship between Hcy, C677T methylenetetrahydrofolate reductase (MTHFR) genotype, and RVT in patients compared with controls. MATERIALS AND METHODS We evaluated the Hcy plasma level of 3114 consecutive participants in 2 Italian centers during a 2-year period. Hyperhomocysteinemia was found in 99 patients and 136 healthy participants. Of the 99 patients, 20 had RVT with a high prevalence of HHcy in the RVT subgroup (20.2%). This result suggested a possible relationship between HHcy and RVT development. We investigated 105 consecutive patients with recent diagnosis of RVT, and we compared them with 226 healthy controls to evaluate whether HHcy may be a risk factor for RVT. RESULTS the prevalence of HHcy was higher in patients compared with controls (34.3% vs 14.2%; P < .001). The MTHFR C677T genotype was found in 69 of 105 (65.7%) patients with RVT (heterozygosity: 40 of 105 and homozygosity: 29 of 105). The control group showed the presence of MTHFR C677T genotype in 169 of 226 participants (74.8%; heterozygosity: 100 of 226 and homozygosity: 69 of 226) without difference between the 2 groups (P = .08). CONCLUSION our study suggests that HHcy is a possible risk factor for RVT development, while no association was found between RVT and the C677T MTHFR genotype.
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Affiliation(s)
- Gianluca Sottilotta
- Hemophilia Centre, Hemostasis and Thrombosis Service, Azienda Ospedaliera "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy.
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Mager A, Orvin K, Koren-Morag N, Lev IE, Assali A, Kornowski R, Shohat M, Battler A, Hasdai D. Impact of homocysteine-lowering vitamin therapy on long-term outcome of patients with coronary artery disease. Am J Cardiol 2009; 104:745-9. [PMID: 19733705 DOI: 10.1016/j.amjcard.2009.05.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2009] [Revised: 05/02/2009] [Accepted: 05/02/2009] [Indexed: 10/20/2022]
Abstract
Elevated homocysteine levels are associated with increased risk for mortality in patients with coronary artery disease (CAD). However, the benefit of homocysteine-lowering therapy remains controversial. The aim of this study was to examine the impact of homocysteine-lowering therapy on the long-term outcomes of patients with CAD and its interaction with the methylenetetrahydrofolate reductase genotype. The study sample included 492 patients with early-onset CAD who were genotyped for the C677T mutation in the methylenetetrahydrofolate reductase gene or screened for elevated homocysteine from January 1997 to December 2002. Folic acid > or =400 microg/day with or without additional B vitamins was administered at the attending physicians' discretion. There was no difference between treated (n = 140) and untreated patients in age, gender, or prevalence of coronary risk factors. Forty-six patients (9%) died during a median follow-up period of 115 months. Treatment was associated with significantly lower all-cause mortality in patients with homocysteine levels >15 micromol/L (4% vs 32%, p <0.001) but not in patients with lower levels (5% vs 7%, p >0.05). On Cox regression analysis, the following factors were independently associated with all-cause mortality: vitamin therapy (hazard ratio 0.33, 95% confidence interval 0.11 to 0.98, p = 0.046), elevated homocysteine level (hazard ratio 3.5, 95% confidence interval 1.31 to 9.43, p = 0.013), and older age (hazard ratio 1.1, 95% confidence interval 1.04 to 1.14, p <0.0001 for an increment of 5 years). The methylenetetrahydrofolate reductase genotype was not associated with outcomes. In conclusion, long-term folate-based vitamin therapy was independently associated with lower all-cause mortality in patients with CAD and elevated homocysteine levels. This association was not observed in patients with lower homocysteine levels.
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Kobzar G, Mardla V, Rätsep I, Samel N. Effect of vitamin B(6) vitamers on platelet aggregation. Platelets 2009; 20:120-4. [PMID: 19235054 DOI: 10.1080/09537100802687674] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The vitamers of vitamin B(6) inhibit platelet aggregation. However, their effect is weak when used separately. After the supplementation of one vitamer, the concentrations of the other ones also increase in plasma due to the interconversion of vitamin B(6) forms. It can be suggested that different vitamers in blood can interact with each other. The aim of this work was to test the effect of different vitamer combinations on platelet aggregation in vitro. Platelet aggregation was induced by ADP, collagen or arachidonic acid and measured photometrically in a Chronolog aggregometer. The inhibition of platelet aggregation by the pairwise combinations of the vitamers was significantly stronger than that of each vitamer separately. The combinations of three and four vitamers were yet more effective, inhibiting platelet aggregation at the concentration of 4 microM. Possible involvement of inhibitory prostaglandins in the effect of vitamin B(6) was studied. The inhibition of platelet aggregation by the vitamers could be prevented by the antagonist of prostacyclin receptors, CAY10441 while the antagonist of prostaglandin D(2) receptors, MK 0524 was ineffective. The results suggest that vitamin B(6) vitamers cause a synergistic inhibitory effect on platelet aggregation at concentrations that can be mediated by the activation of prostacyclin receptors with prostaglandin E(1).
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Affiliation(s)
- Gennadi Kobzar
- Department of Chemistry, Tallinn University of Technology, Tallinn, Estonia.
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Jamison RL, Shih MC, Humphries DE, Guarino PD, Kaufman JS, Goldfarb DS, Warren SR, Gaziano JM, Lavori P. Effect of the MTHFR C677T and A1298C polymorphisms on survival in patients with advanced CKD and ESRD: a prospective study. Am J Kidney Dis 2009; 53:779-89. [PMID: 19272686 DOI: 10.1053/j.ajkd.2008.12.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Accepted: 12/30/2008] [Indexed: 01/20/2023]
Abstract
BACKGROUND Abnormalities in the gene regulating methylenetetrahydrofolate reductase (MTHFR) are associated with increased homocysteine levels and increased mortality in normal and chronic kidney disease (CKD) populations. STUDY DESIGN Gene association study. SETTING & PARTICIPANTS This was a substudy of 677 patients from 21 Veterans Affairs medical centers participating in a randomized clinical trial (Homocysteinemia in Kidney and End-Stage Renal Disease [HOST]) of the effect on all-cause mortality of vitamin-induced lowering of plasma homocysteine levels. Of 677 patients, 213 (31%) were treated by using dialysis (end-stage renal disease [ESRD]) and 464 (69%) had a Cockcroft-Gault estimated creatinine clearance less than 30 mL/min (advanced CKD). PREDICTOR Polymorphisms C677T (rs1801133) and A1298C (rs1801131) of the MTHFR gene. OUTCOMES Unadjusted and adjusted all-cause mortality. MEASUREMENTS DNA was extracted from blood samples and amplified by means of polymerase chain reaction. RESULTS The adjusted hazard ratio in a recessive model of the relationship between the C677T polymorphism and all-cause mortality in all patients was 1.47 (95% confidence interval, 1.00 to 2.16; P = 0.05). In patients with ESRD with the mutant TT genotype, the adjusted hazard ratio for mortality in all patients was 2.27 (95% confidence interval, 1.07 to 4.84; P = 0.03); patients with advanced CKD showed a similar, although not significant, trend. The risk of myocardial infarction (P = 0.05) and composite risk of myocardial infarction, stroke, lower-extremity amputation, and mortality (P = 0.02) were greater in patients with ESRD with the mutant T allele at nucleotide 677. The overall relationship between the A1298C polymorphism and mortality was not significant (P = 0.6). LIMITATIONS Participants were 98% men; DNA samples were not obtained at enrollment in HOST; linkage disequilibrium with another causal polymorphism is a potential confounding factor; and power was reduced by the limited number of participants. CONCLUSIONS These findings provide additional support for the hypothesis that the mutant TT genotype at nucleotide 677 of the gene regulating MTHFR activity may increase the mortality risk in patients with ESRD.
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Affiliation(s)
- Rex L Jamison
- Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA.
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Gupta S, Kühnisch J, Mustafa A, Lhotak S, Schlachterman A, Slifker MJ, Klein-Szanto A, High KA, Austin RC, Kruger WD. Mouse models of cystathionine beta-synthase deficiency reveal significant threshold effects of hyperhomocysteinemia. FASEB J 2008; 23:883-93. [PMID: 18987302 DOI: 10.1096/fj.08-120584] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Untreated cystathionine beta-synthase (CBS) deficiency in humans is characterized by extremely elevated plasma total homocysteine (tHcy>200 microM), with thrombosis as the major cause of morbidity. Treatment with vitamins and diet leads to a dramatic reduction in thrombotic events, even though patients often still have severe elevations in tHcy (>80 microM). To understand the difference between extreme and severe hyperhomocysteinemia, we have examined two mouse models of CBS deficiency: Tg-hCBS Cbs(-/-) mice, with a mean serum tHcy of 169 microM, and Tg-I278T Cbs(-/-) mice, with a mean tHcy of 296 microM. Only Tg-I278T Cbs(-/-) animals exhibited strong biological phenotypes, including facial alopecia, osteoporosis, endoplasmic reticulum (ER) stress in the liver and kidney, and a 20% reduction in mean survival time. Metabolic profiling of serum and liver reveals that Tg-I278T Cbs(-/-) mice have significantly elevated levels of free oxidized homocysteine but not protein-bound homocysteine in serum and elevation of all forms of homocysteine and S-adenosylhomocysteine in the liver compared to Tg-hCBS Cbs(-/-) mice. RNA profiling of livers indicate that Tg-I278T Cbs(-/-) and Tg-hCBS Cbs(-/-) mice have unique gene signatures, with minimal overlap. Our results indicate that there is a clear pathogenic threshold effect for tHcy and bring into question the idea that mild elevations in tHcy are directly pathogenic.
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Affiliation(s)
- Sapna Gupta
- Division of Population Science, Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111, USA
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Kottgen A, Kao WHL, Hwang SJ, Boerwinkle E, Yang Q, Levy D, Benjamin EJ, Larson MG, Astor BC, Coresh J, Fox CS. Genome-wide association study for renal traits in the Framingham Heart and Atherosclerosis Risk in Communities Studies. BMC MEDICAL GENETICS 2008; 9:49. [PMID: 18522750 PMCID: PMC2430944 DOI: 10.1186/1471-2350-9-49] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 06/03/2008] [Indexed: 12/19/2022]
Abstract
BACKGROUND The Framingham Heart Study (FHS) recently obtained initial results from the first genome-wide association scan for renal traits. The study of 70,987 single nucleotide polymorphisms (SNPs) in 1,010 FHS participants provides a list of SNPs showing the strongest associations with renal traits which need to be verified in independent study samples. METHODS Sixteen SNPs were selected for replication based on the most promising associations with chronic kidney disease (CKD), estimated glomerular filtration rate (eGFR), and serum cystatin C in FHS. These SNPs were genotyped in 15,747 participants of the Atherosclerosis in Communities (ARIC) Study and evaluated for association using multivariable adjusted regression analyses. Primary outcomes in ARIC were CKD and eGFR. Secondary prospective analyses were conducted for association with kidney disease progression using multivariable adjusted Cox proportional hazards regression. The definition of the outcomes, all covariates, and the use of an additive genetic model was consistent with the original analyses in FHS. RESULTS The intronic SNP rs6495446 in the gene MTHFS was significantly associated with CKD among white ARIC participants at visit 4: the odds ratio per each C allele was 1.24 (95% CI 1.09-1.41, p = 0.001). Borderline significant associations of rs6495446 were observed with CKD at study visit 1 (p = 0.024), eGFR at study visits 1 (p = 0.073) and 4 (lower mean eGFR per C allele by 0.6 ml/min/1.73 m2, p = 0.043) and kidney disease progression (hazard ratio 1.13 per each C allele, 95% CI 1.00-1.26, p = 0.041). Another SNP, rs3779748 in EYA1, was significantly associated with CKD at ARIC visit 1 (odds ratio per each T allele 1.22, p = 0.01), but only with eGFR and cystatin C in FHS. CONCLUSION This genome-wide association study provides unbiased information implicating MTHFS as a candidate gene for kidney disease. Our findings highlight the importance of replication to identify common SNPs associated with renal traits.
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Affiliation(s)
- Anna Kottgen
- Department of Epidemiology and Welch Center for Prevention, Epidemiology & Clinical Research, Johns Hopkins University, Baltimore, MD, USA
| | - Wen Hong L Kao
- Department of Epidemiology and Welch Center for Prevention, Epidemiology & Clinical Research, Johns Hopkins University, Baltimore, MD, USA
- Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Shih-Jen Hwang
- Center for Population Studies, NHLBI, Bethesda, MD and NHLBI's Framingham Heart Study, Framingham, MA, USA
| | - Eric Boerwinkle
- Human Genetics Center and Institute of Molecular Medicine, University of Texas Health Science Center, Houston, TX, USA
| | - Qiong Yang
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Daniel Levy
- Center for Population Studies, NHLBI, Bethesda, MD and NHLBI's Framingham Heart Study, Framingham, MA, USA
| | - Emelia J Benjamin
- Center for Population Studies, NHLBI, Bethesda, MD and NHLBI's Framingham Heart Study, Framingham, MA, USA
- Division of Cardiology and Department of Preventive Medicine, School of Medicine, Department of Epidemiology, School of Public Health, Boston University, Boston, MA, USA
| | - Martin G Larson
- Center for Population Studies, NHLBI, Bethesda, MD and NHLBI's Framingham Heart Study, Framingham, MA, USA
| | - Brad C Astor
- Department of Epidemiology and Welch Center for Prevention, Epidemiology & Clinical Research, Johns Hopkins University, Baltimore, MD, USA
- Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Josef Coresh
- Department of Epidemiology and Welch Center for Prevention, Epidemiology & Clinical Research, Johns Hopkins University, Baltimore, MD, USA
- Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Caroline S Fox
- Center for Population Studies, NHLBI, Bethesda, MD and NHLBI's Framingham Heart Study, Framingham, MA, USA
- Division of Endocrinology, Hypertension, and Metabolism, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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Massé PG, Tranchant CC, Jougleux JL, Coburn SP, Cole DE. Cardiovascular disease-risk factors in middle-aged osteopaenic women treated with calcium alone or combined to three nutrients essential to artery and bone collagen. J Hum Nutr Diet 2008; 21:117-28. [DOI: 10.1111/j.1365-277x.2008.00852.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Perna AF, Luciano MG, Pulzella P, Satta E, Capasso R, Lombardi C, Ingrosso D, De Santo NG. Is homocysteine toxic in uremia? J Ren Nutr 2008; 18:12-7. [PMID: 18089438 DOI: 10.1053/j.jrn.2007.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
High levels of homocysteine have been implicated as a cardiovascular risk factor in the general population and in patients with chronic renal failure, and particularly patients on hemodialysis. To classify a risk factor as causally related to a certain disease, both strong epidemiologic data and sound basic-science studies establishing a mechanism are needed. Among the latter, the hypomethylation of proteins and DNA, and protein homocysteinylation, have been investigated in uremia, providing for an array of toxic effects in this disease.
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Affiliation(s)
- Alessandra F Perna
- First Division of Nephrology, Department of Pediatrics, and Cardiovascular Research Center, School of Medicine, Second University of Naples, Naples, Italy.
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Abstract
Mildly elevated homocysteine levels (Hcy) increase the risk for atherothrombotic vascular disease in the coronary, cerebrovascular, and peripheral arterial circulations. The molecular mechanisms responsible for decreased bioavailability of endothelium-derived nitric oxide (NO) by Hcy involve an increase of vascular oxidant stress and inhibition of important antioxidant capacity. Glutathione peroxidase-1 (GPx-1), a selenocysteine-containing antioxidant enzyme, may be a key target of Hcy's deleterious actions, and several experimental and clinical studies have demonstrated a complex relationship between plasma total homocysteine (tHcy), GPx-1, and endothelial dysfunction. Hcy may promote endothelial dysfunction, in part by decreasing GPx-1 expression; however, there is evidence to suggest that overexpression of GPx-1 can compensate for these effects. This review summarizes the current knowledge of the metabolism of Hcy, the effects of hyperhomocysteinemia observed in in vitro and in vivo models that lead to endothelial dysfunction and the possible mechanisms for these actions, and the role of GPx-1 in the pathogenesis of Hcy-induced cardiovascular disease (CVD).
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Affiliation(s)
- Edith Lubos
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
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