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Key J, Gispert S, Kandi AR, Heinz D, Hamann A, Osiewacz HD, Meierhofer D, Auburger G. CLPP-Null Eukaryotes with Excess Heme Biosynthesis Show Reduced L-arginine Levels, Probably via CLPX-Mediated OAT Activation. Biomolecules 2024; 14:241. [PMID: 38397478 PMCID: PMC10886707 DOI: 10.3390/biom14020241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/12/2024] [Accepted: 02/16/2024] [Indexed: 02/25/2024] Open
Abstract
The serine peptidase CLPP is conserved among bacteria, chloroplasts, and mitochondria. In humans and mice, its loss causes Perrault syndrome, which presents with growth deficits, infertility, deafness, and ataxia. In the filamentous fungus Podospora anserina, CLPP loss leads to longevity. CLPP substrates are selected by CLPX, an AAA+ unfoldase. CLPX is known to target delta-aminolevulinic acid synthase (ALAS) to promote pyridoxal phosphate (PLP) binding. CLPX may also influence cofactor association with other enzymes. Here, the evaluation of P. anserina metabolomics highlighted a reduction in arginine/histidine levels. In Mus musculus cerebellum, reductions in arginine/histidine and citrulline occurred with a concomitant accumulation of the heme precursor protoporphyrin IX. This suggests that the increased biosynthesis of 5-carbon (C5) chain deltaALA consumes not only C4 succinyl-CoA and C1 glycine but also specific C5 delta amino acids. As enzymes responsible for these effects, the elevated abundance of CLPX and ALAS is paralleled by increased OAT (PLP-dependent, ornithine delta-aminotransferase) levels. Possibly as a consequence of altered C1 metabolism, the proteome profiles of P. anserina CLPP-null cells showed strong accumulation of a methyltransferase and two mitoribosomal large subunit factors. The reduced histidine levels may explain the previously observed metal interaction problems. As the main nitrogen-storing metabolite, a deficiency in arginine would affect the urea cycle and polyamine synthesis. Supplementation of arginine and histidine might rescue the growth deficits of CLPP-mutant patients.
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Affiliation(s)
- Jana Key
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Experimental Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (J.K.); (S.G.); (A.R.K.)
| | - Suzana Gispert
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Experimental Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (J.K.); (S.G.); (A.R.K.)
| | - Arvind Reddy Kandi
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Experimental Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (J.K.); (S.G.); (A.R.K.)
| | - Daniela Heinz
- Institute of Molecular Biosciences, Faculty of Biosciences, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany; (D.H.); (A.H.); (H.D.O.)
| | - Andrea Hamann
- Institute of Molecular Biosciences, Faculty of Biosciences, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany; (D.H.); (A.H.); (H.D.O.)
| | - Heinz D. Osiewacz
- Institute of Molecular Biosciences, Faculty of Biosciences, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany; (D.H.); (A.H.); (H.D.O.)
| | - David Meierhofer
- Max Planck Institute for Molecular Genetics, Ihnestraße 63-73, 14195 Berlin, Germany;
| | - Georg Auburger
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Experimental Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (J.K.); (S.G.); (A.R.K.)
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Temova Rakuša Ž, Roškar R, Hickey N, Geremia S. Vitamin B 12 in Foods, Food Supplements, and Medicines-A Review of Its Role and Properties with a Focus on Its Stability. MOLECULES (BASEL, SWITZERLAND) 2022; 28:molecules28010240. [PMID: 36615431 PMCID: PMC9822362 DOI: 10.3390/molecules28010240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022]
Abstract
Vitamin B12, also known as the anti-pernicious anemia factor, is an essential micronutrient totally dependent on dietary sources that is commonly integrated with food supplements. Four vitamin B12 forms-cyanocobalamin, hydroxocobalamin, 5'-deoxyadenosylcobalamin, and methylcobalamin-are currently used for supplementation and, here, we provide an overview of their biochemical role, bioavailability, and efficacy in different dosage forms. Since the effective quantity of vitamin B12 depends on the stability of the different forms, we further provide a review of their main reactivity and stability under exposure to various environmental factors (e.g., temperature, pH, light) and the presence of some typical interacting compounds (oxidants, reductants, and other water-soluble vitamins). Further, we explore how the manufacturing process and storage affect B12 stability in foods, food supplements, and medicines and provide a summary of the data published to date on the content-related quality of vitamin B12 products on the market. We also provide an overview of the approaches toward their stabilization, including minimization of the destabilizing factors, addition of proper stabilizers, or application of some (innovative) technological processes that could be implemented and contribute to the production of high-quality vitamin B12 products.
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Affiliation(s)
| | - Robert Roškar
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Neal Hickey
- Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
| | - Silvano Geremia
- Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
- Correspondence:
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Hannibal L, Jacobsen DW. Intracellular processing of vitamin B 12 by MMACHC (CblC). VITAMINS AND HORMONES 2022; 119:275-298. [PMID: 35337623 DOI: 10.1016/bs.vh.2022.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Vitamin B12 (cobalamin, Cbl, B12) is a water-soluble micronutrient synthesized exclusively by a group of microorganisms. Human beings are unable to make B12 and thus obtain the vitamin via intake of animal products, fermented plant-based foods or supplements. Vitamin B12 obtained from the diet comprises three major chemical forms, namely hydroxocobalamin (HOCbl), methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl). The most common form of B12 present in supplements is cyanocobalamin (CNCbl). Yet, these chemical forms cannot be utilized directly as they come, but instead, they undergo chemical processing by the MMACHC protein, also known as CblC. Processing of dietary B12 by CblC involves removal of the upper-axial ligand (beta-ligand) yielding the one-electron reduced intermediate cob(II)alamin. Newly formed cob(II)alamin undergoes trafficking and delivery to the two B12-dependent enzymes, cytosolic methionine synthase (MS) and mitochondrial methylmalonyl-CoA mutase (MUT). The catalytic cycles of MS and MUT incorporate cob(II)alamin as a precursor to regenerate the coenzyme forms MeCbl and AdoCbl, respectively. Mutations and epimutations in the MMACHC gene result in cblC disease, the most common inborn error of B12 metabolism, which manifests with combined homocystinuria and methylmalonic aciduria. Elevation of metabolites homocysteine and methylmalonic acid occurs because the lack of an active CblC blocks formation of the indispensable precursor cob(II)alamin that is necessary to activate MS and MUT. Thus, in patients with cblC disease, vitamin B12 is absorbed and present in circulation in normal to high concentrations, yet, cells are unable to make use of it. Mutations in seemingly unrelated genes that modify MMACHC gene expression also result in clinical phenotypes that resemble cblC disease. We review current knowledge on structural and functional aspects of intracellular processing of vitamin B12 by the versatile protein CblC, its partners and possible regulators.
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Affiliation(s)
- Luciana Hannibal
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany.
| | - Donald W Jacobsen
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
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4
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Basgalupp SP, Donis KC, Siebert M, E Vairo FP, Artigalas O, de Camargo Pinto LL, Behringer S, Spiekerkoetter U, Hannibal L, Schwartz IVD. Elevated holo-transcobalamin in Gaucher disease type II: A case report. Am J Med Genet A 2021; 185:2471-2476. [PMID: 34031990 DOI: 10.1002/ajmg.a.62252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/16/2021] [Accepted: 04/24/2021] [Indexed: 11/06/2022]
Abstract
Gaucher disease (GD), one of the most common lysosomal disorders, is caused by deficiency of β-glucocerebrosidase. Based on the presence and severity of neurological complications, GD is classified into types I, II (the most severe form), and III. Abnormalities in systemic markers of vitamin B12 (B12 ) metabolism have been reported in GD type I patients, suggesting a higher prevalence of B12 deficiency in these patients. A 2-month-old male with GD type II was admitted to the hospital presenting jaundice, hepatosplenomegaly, and ichthyosis. At admission, cholestasis and ascites, abnormal liver function enzymes, prolonged prothrombin time, and high levels of B12 were confirmed. Analysis of biomarkers of B12 status revealed elevated B12 and holo-transcobalamin (holo-TC) levels. The B12 profile found in our patient is the opposite to what is described for GD type I patients. Holo-TC may increase in inflammatory states or due to liver diseases. In GD, the accumulation of glucocerebroside may be a trigger that initiates a systemic inflammatory reaction, characterized by macrophage activation. We suggest higher levels of holo-TC could be associated with a more severe (neuronopathic) GD, and be a biomarker of GD type II.
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Affiliation(s)
- Suelen Porto Basgalupp
- Postgraduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Basic Research and Advanced Investigations in Neurosciences (BRAIN) Laboratory, Experimental Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.,Hospital Moinhos de Vento, Porto Alegre, Brazil
| | - Karina Carvalho Donis
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Marina Siebert
- Basic Research and Advanced Investigations in Neurosciences (BRAIN) Laboratory, Experimental Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.,Unit of Laboratorial Research, Experimental Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Filippo Pinto E Vairo
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Osvaldo Artigalas
- Hospital da Criança Conceição, Grupo Hospitalar Conceição (GHC), Porto Alegre, Brazil
| | | | - Sidney Behringer
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center, University of Freiburg, Germany
| | - Ute Spiekerkoetter
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center, University of Freiburg, Germany
| | - Luciana Hannibal
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center, University of Freiburg, Germany
| | - Ida Vanessa D Schwartz
- Postgraduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Basic Research and Advanced Investigations in Neurosciences (BRAIN) Laboratory, Experimental Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.,Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.,Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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Gick GG, Arora K, Sequeira JM, Nakayama Y, Lai SC, Quadros EV. Cellular uptake of vitamin B12: Role and fate of TCblR/CD320, the transcobalamin receptor. Exp Cell Res 2020; 396:112256. [DOI: 10.1016/j.yexcr.2020.112256] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/03/2020] [Accepted: 08/28/2020] [Indexed: 01/03/2023]
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Lyon P, Strippoli V, Fang B, Cimmino L. B Vitamins and One-Carbon Metabolism: Implications in Human Health and Disease. Nutrients 2020; 12:E2867. [PMID: 32961717 PMCID: PMC7551072 DOI: 10.3390/nu12092867] [Citation(s) in RCA: 127] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/17/2020] [Accepted: 09/17/2020] [Indexed: 12/17/2022] Open
Abstract
Vitamins B9 (folate) and B12 are essential water-soluble vitamins that play a crucial role in the maintenance of one-carbon metabolism: a set of interconnected biochemical pathways driven by folate and methionine to generate methyl groups for use in DNA synthesis, amino acid homeostasis, antioxidant generation, and epigenetic regulation. Dietary deficiencies in B9 and B12, or genetic polymorphisms that influence the activity of enzymes involved in the folate or methionine cycles, are known to cause developmental defects, impair cognitive function, or block normal blood production. Nutritional deficiencies have historically been treated with dietary supplementation or high-dose parenteral administration that can reverse symptoms in the majority of cases. Elevated levels of these vitamins have more recently been shown to correlate with immune dysfunction, cancer, and increased mortality. Therapies that specifically target one-carbon metabolism are therefore currently being explored for the treatment of immune disorders and cancer. In this review, we will highlight recent studies aimed at elucidating the role of folate, B12, and methionine in one-carbon metabolism during normal cellular processes and in the context of disease progression.
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Affiliation(s)
- Peter Lyon
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (P.L.); (V.S.); (B.F.)
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Victoria Strippoli
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (P.L.); (V.S.); (B.F.)
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Byron Fang
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (P.L.); (V.S.); (B.F.)
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Luisa Cimmino
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; (P.L.); (V.S.); (B.F.)
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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7
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Basgalupp SP, Siebert M, Ferreira C, Behringer S, Spiekerkoetter U, Hannibal L, Schwartz IVD. Assessment of cellular cobalamin metabolism in Gaucher disease. BMC MEDICAL GENETICS 2020; 21:12. [PMID: 31931749 PMCID: PMC6958775 DOI: 10.1186/s12881-020-0947-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 12/31/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Gaucher disease (GD) is a lysosomal disorder caused by biallelic pathogenic mutations in the GBA1 gene that encodes beta-glucosidase (GCase), and more rarely, by a deficiency in the GCase activator, saposin C. Clinically, GD manifests with heterogeneous multiorgan involvement mainly affecting hematological, hepatic and neurological axes. This disorder is divided into three types, based on the absence (type I) or presence and severity (types II and III) of involvement of the central nervous system. At the cellular level, deficiency of GBA1 disturbs lysosomal storage with buildup of glucocerebroside. The consequences of disturbed lysosomal metabolism on biochemical pathways that require lysosomal processing are unknown. Abnormal systemic markers of cobalamin (Cbl, B12) metabolism have been reported in patients with GD, suggesting impairments in lysosomal handling of Cbl or in its downstream utilization events. METHODS Cultured skin fibroblasts from control humans (n = 3), from patients with GD types I (n = 1), II (n = 1) and III (n = 1) and an asymptomatic carrier of GD were examined for their GCase enzymatic activity and lysosomal compartment intactness. Control human and GD fibroblasts were cultured in growth medium with and without 500 nM hydroxocobalamin supplementation. Cellular cobalamin status was examined via determination of metabolomic markers in cell lysate (intracellular) and conditioned culture medium (extracellular). The presence of transcobalamin (TC) in whole cell lysates was examined by Western blot. RESULTS Cultured skin fibroblasts from GD patients exhibited reduced GCase activity compared to healthy individuals and an asymptomatic carrier of GD, demonstrating a preserved disease phenotype in this cell type. The concentrations of total homocysteine (tHcy), methylmalonic acid (MMA), cysteine (Cys) and methionine (Met) in GD cells were comparable to control levels, except in one patient with GD III. The response of these metabolomic markers to supplementation with hydroxocobalamin (HOCbl) yielded variable results. The content of transcobalamin in whole cell lysates was comparable in control human and GD patients. CONCLUSIONS Our results indicate that cobalamin transport and cellular processing pathways are overall protected from lysosomal storage damage in GD fibroblasts. Extending these studies to hepatocytes, macrophages and plasma will shed light on cell- and compartment-specific vitamin B12 metabolism in Gaucher disease.
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Affiliation(s)
- Suelen Porto Basgalupp
- Postgraduate Program in Medical Sciences, Faculty of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Basic Research and Advanced Investigations in Neurosciences (BRAIN) Laboratory, Experimental Research Center. Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Marina Siebert
- Basic Research and Advanced Investigations in Neurosciences (BRAIN) Laboratory, Experimental Research Center. Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.,Unit of Laboratorial Research, Experimental Research Center, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
| | - Charles Ferreira
- Postgraduate Program in Health Sciences, Gynecology and Obstetrics (PPGGO), Faculty of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Sidney Behringer
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ute Spiekerkoetter
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Luciana Hannibal
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - Ida Vanessa Doederlein Schwartz
- Postgraduate Program in Medical Sciences, Faculty of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. .,Basic Research and Advanced Investigations in Neurosciences (BRAIN) Laboratory, Experimental Research Center. Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil. .,Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil. .,Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
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Richard E, Brasil S, Leal F, Navarrete R, Vega A, Ecay MJ, Desviat LR, Pérez-Cerda C, Ugarte M, Merinero B, Pérez B. Isolated and Combined Remethylation Disorders. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2017. [DOI: 10.1177/2326409816685732] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Eva Richard
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Sandra Brasil
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Fátima Leal
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Rosa Navarrete
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Ana Vega
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - María Jesús Ecay
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Lourdes R. Desviat
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Celia Pérez-Cerda
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Magdalena Ugarte
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Begoña Merinero
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
| | - Belén Pérez
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular-SO UAM-CSIC, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- IdiPAZ, Madrid, Spain
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Rizzo G, Laganà AS, Rapisarda AMC, La Ferrera GMG, Buscema M, Rossetti P, Nigro A, Muscia V, Valenti G, Sapia F, Sarpietro G, Zigarelli M, Vitale SG. Vitamin B12 among Vegetarians: Status, Assessment and Supplementation. Nutrients 2016; 8:E767. [PMID: 27916823 PMCID: PMC5188422 DOI: 10.3390/nu8120767] [Citation(s) in RCA: 177] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 11/23/2016] [Accepted: 11/23/2016] [Indexed: 02/06/2023] Open
Abstract
Cobalamin is an essential molecule for humans. It acts as a cofactor in one-carbon transfers through methylation and molecular rearrangement. These functions take place in fatty acid, amino acid and nucleic acid metabolic pathways. The deficiency of vitamin B12 is clinically manifested in the blood and nervous system where the cobalamin plays a key role in cell replication and in fatty acid metabolism. Hypovitaminosis arises from inadequate absorption, from genetic defects that alter transport through the body, or from inadequate intake as a result of diet. With the growing adoption of vegetarian eating styles in Western countries, there is growing focus on whether diets that exclude animal foods are adequate. Since food availability in these countries is not a problem, and therefore plant foods are sufficiently adequate, the most delicate issue remains the contribution of cobalamin, which is poorly represented in plants. In this review, we will discuss the status of vitamin B12 among vegetarians, the diagnostic markers for the detection of cobalamin deficiency and appropriate sources for sufficient intake, through the description of the features and functions of vitamin B12 and its absorption mechanism.
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Affiliation(s)
| | - Antonio Simone Laganà
- Unit of Gynecology and Obstetrics, Department of Human Pathology in Adulthood and Childhood, "G. Barresi", University of Messina, Via Consolare Valeria 1, Messina 98125, Italy.
| | - Agnese Maria Chiara Rapisarda
- Department of General Surgery and Medical Surgical Specialties, University of Catania, Via S. Sofia 78, Catania 95124, Italy.
| | - Gioacchina Maria Grazia La Ferrera
- Department of Gastroenterology and Digestive Endoscopy Maddalena Raimondi San Cataldo, Via Forlanini 5, San Cataldo, Caltanissetta 93017, Italy.
| | - Massimo Buscema
- Unit of Diabetology and Endocrino-Metabolic Diseases, Hospital for Emergency Cannizzaro, Via Messina 829, Catania 95126, Italy.
| | - Paola Rossetti
- Unit of Diabetology and Endocrino-Metabolic Diseases, Hospital for Emergency Cannizzaro, Via Messina 829, Catania 95126, Italy.
| | - Angela Nigro
- Unit of Diabetology and Endocrino-Metabolic Diseases, Hospital for Emergency Cannizzaro, Via Messina 829, Catania 95126, Italy.
| | - Vincenzo Muscia
- Unit of Diabetology and Endocrino-Metabolic Diseases, Hospital for Emergency Cannizzaro, Via Messina 829, Catania 95126, Italy.
| | - Gaetano Valenti
- Department of General Surgery and Medical Surgical Specialties, University of Catania, Via S. Sofia 78, Catania 95124, Italy.
| | - Fabrizio Sapia
- Department of General Surgery and Medical Surgical Specialties, University of Catania, Via S. Sofia 78, Catania 95124, Italy.
| | - Giuseppe Sarpietro
- Department of General Surgery and Medical Surgical Specialties, University of Catania, Via S. Sofia 78, Catania 95124, Italy.
| | - Micol Zigarelli
- Department of General Surgery and Medical Surgical Specialties, University of Catania, Via S. Sofia 78, Catania 95124, Italy.
| | - Salvatore Giovanni Vitale
- Unit of Gynecology and Obstetrics, Department of Human Pathology in Adulthood and Childhood, "G. Barresi", University of Messina, Via Consolare Valeria 1, Messina 98125, Italy.
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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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11
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Translocation of the ABC transporter ABCD4 from the endoplasmic reticulum to lysosomes requires the escort protein LMBD1. Sci Rep 2016; 6:30183. [PMID: 27456980 PMCID: PMC4960490 DOI: 10.1038/srep30183] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 06/30/2016] [Indexed: 11/29/2022] Open
Abstract
We previously demonstrated that ABCD4 does not localize to peroxisomes but rather, the endoplasmic reticulum (ER), because it lacks the NH2-terminal hydrophilic region required for peroxisomal targeting. It was recently reported that mutations in ABCD4 result in a failure to release vitamin B12 from lysosomes. A similar phenotype is caused by mutations in LMBRD1, which encodes the lysosomal membrane protein LMBD1. These findings suggested to us that ABCD4 translocated from the ER to lysosomes in association with LMBD1. In this report, it is demonstrated that ABCD4 interacts with LMBD1 and then localizes to lysosomes, and this translocation depends on the lysosomal targeting ability of LMBD1. Furthermore, endogenous ABCD4 was localized to both lysosomes and the ER, and its lysosomal localization was disturbed by knockout of LMBRD1. To the best of our knowledge, this is the first report demonstrating that the subcellular localization of the ABC transporter is determined by its association with an adaptor protein.
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12
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Buers I, Pennekamp P, Nitschke Y, Lowe C, Skryabin BV, Rutsch F. Lmbrd1 expression is essential for the initiation of gastrulation. J Cell Mol Med 2016; 20:1523-33. [PMID: 27061115 PMCID: PMC4956942 DOI: 10.1111/jcmm.12844] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/24/2016] [Indexed: 01/06/2023] Open
Abstract
The rare inborn cblF defect of cobalamin metabolism is caused by mutations in the limb region 1 (LMBR1) domain containing 1 gene (LMBRD1). This defect is characterized by massive accumulation of free cobalamin in lysosomes and loss of mitochondrial succinyl‐CoA synthesis and cytosolic methionine synthesis. Affected children suffer from heart defects, developmental delay and megaloblastic anemia. LMBRD1 encodes for LMBD1, a predicted lysosomal cobalamin transport protein. In this study, we determine the physiological function of LMBRD1 during embryogenesis by generating Lmbrd1 deficient mice using the Cre/LoxP system. Complete loss of Lmbrd1 function is accompanied by early embryonic death in mice. Whole mount in situ hybridization studies against bone morphogenetic protein 4 and Nodal show that initial formation of the proximal–distal axis is unaffected in early embryonic stages whereas the initiation of gastrulation is disturbed shown by the expression pattern of even skipped homeotic gene 1 and fibroblast growth factor 8 in Lmbrd1 deficient mice. We conclude that intact function of LMBD1 is essential for the initiation of gastrulation.
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Affiliation(s)
- Insa Buers
- Department of General Pediatrics, Müenster University Children's Hospital, Müenster, Germany
| | - Petra Pennekamp
- Department of General Pediatrics, Müenster University Children's Hospital, Müenster, Germany
| | - Yvonne Nitschke
- Department of General Pediatrics, Müenster University Children's Hospital, Müenster, Germany
| | - Chrishanthi Lowe
- Department of General Pediatrics, Müenster University Children's Hospital, Müenster, Germany
| | - Boris V Skryabin
- Institute of Experimental Pathology, Müenster University, Müenster, Germany.,Department of Medicine (TRAM), University Hospital of Müenster, Münster, Germany
| | - Frank Rutsch
- Department of General Pediatrics, Müenster University Children's Hospital, Müenster, Germany
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13
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Ktena YP, Ramstad T, Baker EH, Sloan JL, Mannes AJ, Manoli I, Venditti CP. Propofol administration in patients with methylmalonic acidemia and intracellular cobalamin metabolism disorders: a review of theoretical concerns and clinical experiences in 28 patients. J Inherit Metab Dis 2015; 38:847-53. [PMID: 25985870 PMCID: PMC5577977 DOI: 10.1007/s10545-015-9816-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 01/18/2015] [Accepted: 01/22/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND Methylmalonic acidemia and intracellular cobalamin metabolism disorders represent a heterogeneous group of inborn errors of metabolism. Most patients will require diagnostic and/or therapeutic procedures frequently requiring sedation or anesthetic management due to neurological and neurocognitive impairments. It has been stated that propofol is contraindicated in this population. We report our experience with propofol administration in a large series of patients. METHODS Twenty eight patients (14 mut, seven cblC, three cblA, three cblB, one cblG) aged 2-35.6 years enrolled in a natural history study (ClinicalTrials.gov identifier: NCT00078078) and required anesthetics for 39 diagnostic or therapeutic procedures. Data were collected on the anesthetic technique, perianesthetic course, and adverse events related to propofol. RESULTS Propofol was used as the sole induction agent in most cases (36/39) and as the primary maintenance agent in all cases. Infusion rates were 100-400 mcg kg(-1) min(-1) (mean = 214). Infusion duration was 60-325 min (mean = 158) and total doses ranged between 270-3610 mg (mean = 1217). Adverse events were recorded in two cases; neither appeared to be related to propofol administration. CONCLUSIONS Propofol is an effective, safe induction and maintenance agent for elective short procedures requiring anesthesia in patients with MMA and cobalamin metabolism disorders. Despite multiple comorbidities and propensity toward instability, those affected can receive anesthesia with an acceptable safety profile, if metabolically and hemodynamically stabilized prior to the event. SYNOPSIS A review of the perianesthetic records of 28 patients with isolated MMA and intracellular cobalamin metabolism disorders suggests that propofol anesthesia can be administered safely to these patients, in the setting of metabolic stability.
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Affiliation(s)
- Yiouli P Ktena
- Organic Acid Research Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, 49 Convent Drive, Building 49, Room 4A18, Bethesda, MD, USA
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14
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Obeid R, Fedosov SN, Nexo E. Cobalamin coenzyme forms are not likely to be superior to cyano- and hydroxyl-cobalamin in prevention or treatment of cobalamin deficiency. Mol Nutr Food Res 2015; 59:1364-72. [PMID: 25820384 PMCID: PMC4692085 DOI: 10.1002/mnfr.201500019] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/25/2015] [Accepted: 03/25/2015] [Indexed: 12/12/2022]
Abstract
Methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl) are coenzymes for methionine synthase and methylmalonyl-CoA mutase, respectively. Hydroxylcobalamin (HOCbl) and cyanocobalamin (CNCbl) are frequently used for supplementation. MeCbl and AdoCbl have recently emerged as alternative forms in supplements. In the light of metabolic transformation of Cbl into its cofactor forms, this review discusses current evidence on efficacy and utility of different Cbl forms in preventing or treating Cbl deficiency. Cbl-transporting proteins bind and mediate the uptake of all aforementioned forms of Cbl. After internalization and lysosomal release, Cbl binds to the cytosolic chaperon MMACHC that is responsible for (i) flavin-dependent decyanation of [CN-Co3+]Cbl to [Co2+]Cbl; (ii) glutathione-dependent dealkylation of MeCbl and AdoCbl to [Co2+/1+]Cbl; and (iii) glutathione-dependent decyanation of CNCbl or reduction of HOCbl under anaerobic conditions. MMACHC shows a broad specificity for Cbl forms and supplies the Cbl2+ intermediate for synthesis of MeCbl and AdoCbl. Cobalamin chemistry, physiology, and biochemistry suggest that MeCbl and AdoCbl follow the same route of intracellular processing as CNCbl does. We conclude that supplementing MeCbl or AdoCbl is unlikely to be advantageous compared to CNCbl. On the other hand, there are obvious advantages of high parenteral doses (1–2 mg) of HOCbl in treating inborn errors of Cbl metabolism.
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Affiliation(s)
- Rima Obeid
- Aarhus Institute of Advanced Studies, , University of Aarhus, Aarhus, Denmark.,Department of Clinical Chemistry, University Hospital of the Saarland, Homburg, Germany
| | - Sergey N Fedosov
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus C, Denmark.,Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Ebba Nexo
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus C, Denmark
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15
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Diagnostic Exome Sequencing and Tailored Bioinformatics of the Parents of a Deceased Child with Cobalamin Deficiency Suggests Digenic Inheritance of the MTR and LMBRD1 Genes. JIMD Rep 2014; 15:29-37. [PMID: 24664876 DOI: 10.1007/8904_2014_294] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 01/06/2014] [Accepted: 01/16/2014] [Indexed: 01/08/2023] Open
Abstract
Disorders of cobalamin deficiency are a heterogeneous group of disorders with at least 19 autosomal recessive-associated genes. Familial samples of an infant who died due to presumed cobalamin deficiency were referred for clinical exome sequencing. The patient died before obtaining a blood sample or skin biopsy, autopsy was declined, and DNA yielded from the newborn screening blood spot was insufficient for diagnostic testing. Whole-exome sequencing of the mother, father, and unaffected sister and tailored bioinformatics analysis was applied to search for mutations in underlying disorders with recessive inheritance. This approach identified alterations within two genes, each of which was carried by one parent. The mother carried a missense alteration in the MTR gene (c.3518C>T; p.P1173L) which was absent in the father and the sister. The father carried a translational frameshift alteration in the LMBRD1 gene (c.1056delG; p.L352Lfs*18) which was absent in the mother and present in the heterozygous state in the sister. These mutations in the MTR (MIM# 156570) and LMBRD1 (MIM# 612625) genes have been described in patients with disorders of cobalamin metabolism complementation groups cblG and cblF, respectively. The child's clinical presentation and biochemical results demonstrated overlap with both cblG and cblF. Sanger sequencing using DNA from the infant's blood spot confirmed the inheritance of the two alterations in compound heterozygous form. We present the first example of exome sequencing leading to a diagnosis in the absence of the affected patient. Furthermore, the data support the possibility for potential digenic inheritance associated with cobalamin deficiency.
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16
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Perturbation of neuronal cobalamin transport by lysosomal enzyme inhibition. Biosci Rep 2014; 34:BSR20130130. [PMID: 27919045 PMCID: PMC3908614 DOI: 10.1042/bsr20130130] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 01/03/2014] [Accepted: 01/06/2014] [Indexed: 11/17/2022] Open
Abstract
Cbl (cobalamin) utilization as an enzyme cofactor is dependent on its efficient transit through lysosomes to the cytosol and mitochondria. We have previously proposed that pathophysiological perturbations in lysosomal function may inhibit intracellular Cbl transport with consequences for down-stream metabolic pathways. In the current study, we used both HT1080 fibroblasts and SH-SY5Y neurons to assess the impact that protease inhibitors, chloroquine and leupeptin (N-acetyl-L-leucyl-L-leucyl-L-argininal), have on the distribution of [57Co]Cbl in lysosomes, mitochondria and cytosol. Under standard cell culture conditions the distribution of [57Co]Cbl in both neurons and fibroblasts was ~5% in lysosomes, 14% in mitochondria and 81% in cytosol. Treatment of cells with either 25 μM chloroquine or 40 μM leupeptin for 48 h significantly increased the lysosomal [57Co]Cbl levels, by 4-fold in fibroblasts and 10-fold in neurons, and this was associated with reduced cytosolic and mitochondrial [57Co]Cbl concentrations. Based on Western blotting of LAMP2 in fractions recovered from an OptiPrep density gradient, lysosomal Cbl trapping was associated with an expansion of the lysosomal compartment and an increase in a subpopulation of lysosomes with increased size and density. Moreover, the decreased mitochondrial Cbl that was associated with lysosomal Cbl trapping was correlated with decreased incorporation of [14C] propionate into cellular proteins/macromolecules, indicating an inhibition of Cbl-dependent Mm-CoA (methylmalonyl-coenzyme A) mutase activity. These results add support to the idea that lysosomal dysfunction may significantly impact upon Cbl transport and utilization.
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17
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Zhao H, Ruberu K, Li H, Garner B. Analysis of subcellular [57Co] cobalamin distribution in SH-SY5Y neurons and brain tissue. J Neurosci Methods 2013; 217:67-74. [DOI: 10.1016/j.jneumeth.2013.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/11/2013] [Accepted: 04/11/2013] [Indexed: 10/26/2022]
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18
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Kirsch SH, Herrmann W, Obeid R. Genetic defects in folate and cobalamin pathways affecting the brain. Clin Chem Lab Med 2013. [DOI: 10.1515/cclm-2012-0673] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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19
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Abstract
BACKGROUND Vitamin B12 (cobalamin) is a cobalt-containing compound synthesized by bacteria and an essential nutrient in mammals, which take it up from diet. The absorption and distribution of dietary vitamin B12 to the organism is a complex process involving several gene products including carrier proteins, plasma membrane receptors and transporters. Disturbed cellular entry, transit or egress of vitamin B12 may lead to low vitamin B12 status or deficiency and eventually hematological and neurological disorders. OBJECTIVE The aim of this review is to summarize the causes leading to vitamin B12 deficiency including decreased intake, impaired absorption and increased requirements. Under physiological conditions, vitamin B12 bound to the gastric intrinsic factor is internalized in the ileum by a highly specific receptor complex composed by Cubilin (Cubn) and Amnionless (Amn). Following exit of vitamin B12 from the ileum, general cellular uptake from the circulation requires the transcobalamin receptor CD320 whereas kidney reabsorption of cobalamin depends on Megalin (Lrp2). Whereas malabsorption of vitamin B12 is most commonly seen in the elderly, selective pediatric, nondietary-induced B12 deficiency is generally due to inherited disorders including the Imerslund-Gräsbeck syndrome and the much rarer intrinsic factor deficiency. Biochemical, clinical and genetic research on these disorders considerably improved our knowledge of vitamin B12 absorption. This review describes basic and recent findings on the intestinal handling of vitamin B12 and its importance in health and disease.
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20
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Evidence of an evolutionarily conserved LMBR1 domain-containing protein that associates with endocytic cups and plays a role in cell migration in dictyostelium discoideum. EUKARYOTIC CELL 2012; 11:401-16. [PMID: 22307974 DOI: 10.1128/ec.05186-11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The ampA gene plays a role in Dictyostelium discoideum cell migration. Loss of ampA function results in reduced ability of growing cells to migrate to folic acid and causes small plaques on bacterial lawns, while overexpression of AmpA results in a rapid-migration phenotype and correspondingly larger plaques than seen with wild-type cells. To help understand how the ampA gene functions, second-site suppressors were created by restriction enzyme-mediated integration (REMI) mutagenesis. These mutants were selected for their ability to reduce the large plaque size of the AmpA overexpresser strain. The lmbd2B gene was identified as a suppressor of an AmpA-overexpressing strain. The lmbd2B gene product belongs to the evolutionarily conserved LMBR1 protein family, some of whose known members are endocytic receptors associated with human diseases, such as anemia. In order to understand lmbd2B function, mRFP fusion proteins were created and lmbd2B knockout cell lines were established. Our findings indicate that the LMBD2B protein is found associated with endocytic cups. It colocalizes with proteins that play key roles in endocytic events and is localized to ruffles on the dorsal surfaces of growing cells. Vegetative lmbd2B-null cells display defects in cell migration. These cells have difficulty sensing the chemoattractant folic acid, as indicated by a decrease in their chemotactic index. lmbd2B-null cells also appear to have difficulty establishing a front/back orientation to facilitate migration. A role for lmbd2B in development is also suggested. Our research gives insight into the function of a previously uncharacterized branch of the LMBR1 family of proteins. We provide evidence of an LMBR1 family plasma membrane protein that associates with endocytic cups and plays a role in chemotaxis.
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Oladipo O, Rosenblatt DS, Watkins D, Miousse IR, Sprietsma L, Dietzen DJ, Shinawi M. Cobalamin F disease detected by newborn screening and follow-up on a 14-year-old patient. Pediatrics 2011; 128:e1636-40. [PMID: 22065268 DOI: 10.1542/peds.2010-3518] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The cobalamin F (cblF) defect is caused by disturbed lysosomal release of cobalamin (vitamin B(12)) into the cytoplasm caused by mutations in the LMBRD1 gene. We present the clinical and biochemical characterization of a patient with newly diagnosed cblF disease and a follow-up on a 14-year-old patient. The new patient presented with elevation of propionyl carnitine found on a newborn screen. The patient was small for gestational age, exhibited dysmorphic features and mild developmental delay, and had trigonocephaly and ventricular septal defect. There was biochemical normalization and clinical improvement within 3 weeks of parenteral cobalamin treatment. The other patient presented at 4 weeks of life with failure to thrive and feeding difficulties. She was treated only with monthly cyanocobalamin shots. The patient has never experienced metabolic decompensation. She had short stature and was an average student with no behavioral concerns. Her metabolic derangements normalized after switching to weekly hydroxycobalamin. The available data on 14 patients with confirmed cblF disease suggest variability in age of onset, presenting symptoms, response to treatment, and long-term complications. Common clinical findings include small for gestational age, feeding difficulties, growth failure, and developmental delays. Some patients have congenital heart defects, dysmorphic features, and other congenital anomalies.
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Affiliation(s)
- Olajumoke Oladipo
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO 63110, USA
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Zhao H, Brunk UT, Garner B. Age-related lysosomal dysfunction: an unrecognized roadblock for cobalamin trafficking? Cell Mol Life Sci 2011; 68:3963-9. [PMID: 22015613 PMCID: PMC11114728 DOI: 10.1007/s00018-011-0861-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 09/30/2011] [Accepted: 10/05/2011] [Indexed: 01/10/2023]
Abstract
Vitamin-B(12) is a generic term for corrinoid compounds that exhibit the biological activity of cyanocobalamin and are collectively referred to as cobalamins. Methylcobalamin and 5-deoxyadenosylcobalamin are the active cobalamins in human metabolism. Cobalamin plays a crucial role in the maintenance of homocysteine and methylmalonyl-CoA homeostasis and is required for erythrocyte formation and DNA synthesis. Data from human and animal studies indicate that cobalamin deficiency impairs neuronal function; a process that is thought to contribute to age-related cognitive decline and dementia. Cobalamin deficiency also results in dysfunction of the peripheral nervous system; among other disorders. Although there is a detailed understanding of the biochemical pathways that are perturbed in cobalamin deficiency, the mechanisms underlying age-related dyshomeostasis in such pathways remain to be addressed. Because cobalamin utilization is dependent on its efficient transit through lysosomes, and mounting evidence indicates that lysosomal function deteriorates in aging long-lived post-mitotic cells such as neurons, in the present article we review published data that supports the proposition that impaired lysosomal processing of cobalamin may play a significant role in age-related (neuro) degenerative diseases.
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Affiliation(s)
- Hua Zhao
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia.
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