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Wiedemann A, Oussalah A, Guéant Rodriguez RM, Jeannesson E, Mertens M, Rotaru I, Alberto JM, Baspinar O, Rashka C, Hassan Z, Siblini Y, Matmat K, Jeandel M, Chery C, Robert A, Chevreux G, Lignières L, Camadro JM, Feillet F, Coelho D, Guéant JL. Multiomic analysis in fibroblasts of patients with inborn errors of cobalamin metabolism reveals concordance with clinical and metabolic variability. EBioMedicine 2024; 99:104911. [PMID: 38168585 PMCID: PMC10794925 DOI: 10.1016/j.ebiom.2023.104911] [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: 01/17/2023] [Revised: 11/28/2023] [Accepted: 11/28/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND The high variability in clinical and metabolic presentations of inborn errors of cobalamin (cbl) metabolism (IECM), such as the cblC/epicblC types with combined deficits in methylmalonyl-coA mutase (MUT) and methionine synthase (MS), are not well understood. They could be explained by the impaired expression/activity of enzymes from other metabolic pathways. METHODS We performed metabolomic, genomic, proteomic, and post-translational modification (PTM) analyses in fibroblasts from three cblC cases and one epi-cblC case compared with three cblG cases with specific MS deficits and control fibroblasts. FINDINGS CblC patients had metabolic profilings consistent with altered urea cycle, glycine, and energy mitochondrial metabolism. Metabolomic analysis showed partial disruption and increased glutamate/ketoglutarate anaplerotic pathway of the tricarboxylic acid cycle (TCA), in patient fibroblasts. RNA-seq analysis showed decreased expression of MT-TT (mitochondrial tRNA threonine), MT-TP (mitochondrial tRNA proline), OXCT1 (succinyl CoA:3-oxoacid CoA transferase deficiency), and MT-CO1 (cytochrome C oxidase subunit 1). Proteomic changes were observed for key mitochondrial enzymes, including NADH:ubiquinone oxidoreductase subunit A8 (NDUFA8), carnitine palmitoyltransferase 2 (CPT2), and ubiquinol-cytochrome C reductase, complex III subunit X (UQCR10). Propionaldehyde addition in ornithine aminotransferase was the predominant PTM in cblC cells and could be related with the dramatic cellular increase in propionate and methylglyoxalate. It is consistent with the decreased concentration of ornithine reported in 3 cblC cases. Whether the changes detected after multi-omic analyses underlies clinical features in cblC and cblG types of IECM, such as peripheral and central neuropathy, cardiomyopathy, pulmonary hypertension, development delay, remains to be investigated. INTERPRETATION The omics-related effects of IECM on other enzymes and metabolic pathways are consistent with the diversity and variability of their age-related metabolic and clinical manifestations. PTMs are expected to produce cumulative effects, which could explain the influence of age on neurological manifestations. FUNDING French Agence Nationale de la Recherche (Projects PREDICTS and EpiGONE) and Inserm.
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Affiliation(s)
- Arnaud Wiedemann
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France; National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy, F-54000, France
| | - Abderrahim Oussalah
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France; National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy, F-54000, France
| | - Rosa-Maria Guéant Rodriguez
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France; National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy, F-54000, France
| | - Elise Jeannesson
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France; National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy, F-54000, France
| | - Marc Mertens
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy, F-54000, France
| | - Irina Rotaru
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France; National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy, F-54000, France
| | - Jean-Marc Alberto
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France
| | - Okan Baspinar
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France
| | - Charif Rashka
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France
| | - Ziad Hassan
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France
| | - Youssef Siblini
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France
| | - Karim Matmat
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France
| | - Manon Jeandel
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France
| | - Celine Chery
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France
| | - Aurélie Robert
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France
| | - Guillaume Chevreux
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013, Paris, France
| | - Laurent Lignières
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013, Paris, France
| | | | - François Feillet
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France; National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy, F-54000, France
| | - David Coelho
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France; National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy, F-54000, France
| | - Jean-Louis Guéant
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, Nancy, F-54000, France; National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, Nancy, F-54000, France.
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Matmat K, Conart JB, Graindorge PH, El Kouche S, Hassan Z, Siblini Y, Umoret R, Safar R, Baspinar O, Robert A, Alberto JM, Oussalah A, Coelho D, Guéant JL, Guéant-Rodriguez RM. A transgenic mice model of retinopathy of cblG-type inherited disorder of one-carbon metabolism highlights epigenome-wide alterations related to cone photoreceptor cells development and retinal metabolism. Clin Epigenetics 2023; 15:158. [PMID: 37798757 PMCID: PMC10557304 DOI: 10.1186/s13148-023-01567-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 09/12/2023] [Indexed: 10/07/2023] Open
Abstract
BACKGROUND MTR gene encodes the cytoplasmic enzyme methionine synthase, which plays a pivotal role in the methionine cycle of one-carbon metabolism. This cycle holds a significant importance in generating S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), the respective universal methyl donor and end-product of epigenetic transmethylation reactions. cblG type of inherited disorders of vitamin B12 metabolism due to mutations in MTR gene exhibits a wide spectrum of symptoms, including a retinopathy unresponsive to conventional therapies. METHODS To unveil the underlying epigenetic pathological mechanisms, we conducted a comprehensive study of epigenomic-wide alterations of DNA methylation by NGS of bisulfited retinal DNA in an original murine model with conditional Mtr deletion in retinal tissue. Our focus was on postnatal day 21, a critical developmental juncture for ocular structure refinement and functional maturation. RESULTS We observed delayed eye opening and impaired visual acuity and alterations in the one-carbon metabolomic profile, with a notable dramatic decline in SAM/SAH ratio predicted to impair DNA methylation. This metabolic disruption led to epigenome-wide changes in genes involved in eye development, synaptic plasticity, and retinoid metabolism, including promoter hypermethylation of Rarα, a regulator of Lrat expression. Consistently, we observed a decline in cone photoreceptor cells and reduced expression of Lrat, Rpe65, and Rdh5, three pivotal genes of eye retinoid metabolism. CONCLUSION We introduced an original in vivo model for studying cblG retinopathy, which highlighted the pivotal role of altered DNA methylation in eye development, cone differentiation, and retinoid metabolism. This model can be used for preclinical studies of novel therapeutic targets.
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Affiliation(s)
- Karim Matmat
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - Jean-Baptiste Conart
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
- Department of Ophthalmology, University Regional Hospital Center of Nancy, 54000, Nancy, France
| | - Paul-Henri Graindorge
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - Sandra El Kouche
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - Ziad Hassan
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - Youssef Siblini
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - Rémy Umoret
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - Ramia Safar
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - Okan Baspinar
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - Aurélie Robert
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - Jean-Marc Alberto
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - Abderrahim Oussalah
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
| | - David Coelho
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, 54000, Nancy, France
| | - Jean-Louis Guéant
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France.
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, 54000, Nancy, France.
- Faculté de Médecine, Bâtiment C 2Ème Étage, 9 Avenue de La Forêt de Haye, 54505, Vandœuvre-lès-Nancy, France.
| | - Rosa-Maria Guéant-Rodriguez
- Inserm UMRS 1256 NGERE - Nutrition, Genetics, and Environmental Risk Exposure, University of Lorraine, 54500, Vandoeuvre-lès-Nancy, France.
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, 54000, Nancy, France.
- Faculté de Médecine, Bâtiment C 2Ème Étage, 9 Avenue de La Forêt de Haye, 54505, Vandœuvre-lès-Nancy, France.
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Wiedemann A, Oussalah A, Lamireau N, Théron M, Julien M, Mergnac JP, Augay B, Deniaud P, Alix T, Frayssinoux M, Feillet F, Guéant JL. Clinical, phenotypic and genetic landscape of case reports with genetically proven inherited disorders of vitamin B 12 metabolism: A meta-analysis. Cell Rep Med 2022; 3:100670. [PMID: 35764087 PMCID: PMC9381384 DOI: 10.1016/j.xcrm.2022.100670] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 11/22/2021] [Accepted: 06/02/2022] [Indexed: 10/31/2022]
Abstract
Inherited disorders of B12 metabolism produce a broad spectrum of manifestations, with limited knowledge of the influence of age and the function of related genes. We report a meta-analysis on 824 patients with a genetically proven diagnosis of an inherited disorder of vitamin B12 metabolism. Gene clusters and age categories are associated with patients' manifestations. The "cytoplasmic transport" cluster is associated with neurological and ophthalmological manifestations, the "mitochondrion" cluster with hypotonia, acute metabolic decompensation, and death, and the "B12 availability" and "remethylation" clusters with anemia and cytopenia. Hypotonia, EEG abnormalities, nystagmus, and strabismus are predominant in the younger patients, while neurological manifestations, such as walking difficulties, peripheral neuropathy, pyramidal syndrome, cerebral atrophy, psychiatric disorders, and thromboembolic manifestations, are predominant in the older patients. These results should prompt systematic checking of markers of vitamin B12 status, including homocysteine and methylmalonic acid, when usual causes of these manifestations are discarded in adult patients.
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Affiliation(s)
- Arnaud Wiedemann
- Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM UMR_S 1256, 54000 Nancy, France; Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France; Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000 Nancy, France
| | - Abderrahim Oussalah
- Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM UMR_S 1256, 54000 Nancy, France; Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000 Nancy, France; Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital of Nancy, 54000 Nancy, France
| | - Nathalie Lamireau
- Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France
| | - Maurane Théron
- Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France
| | - Melissa Julien
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital of Nancy, 54000 Nancy, France
| | | | - Baptiste Augay
- Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France
| | - Pauline Deniaud
- Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France
| | - Tom Alix
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital of Nancy, 54000 Nancy, France
| | - Marine Frayssinoux
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital of Nancy, 54000 Nancy, France
| | - François Feillet
- Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM UMR_S 1256, 54000 Nancy, France; Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France; Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000 Nancy, France
| | - Jean-Louis Guéant
- Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM UMR_S 1256, 54000 Nancy, France; Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000 Nancy, France; Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital of Nancy, 54000 Nancy, France.
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Structural Study of the Complex of cblC Methylmalonic Aciduria and Homocystinuria-Related Protein MMACHC with Cyanocobalamin. CRYSTALS 2022. [DOI: 10.3390/cryst12040468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
MMACHC is an essential protein for the body to metabolise vitamin B12, and its deficiency will cause cblC-type methylmalonic aciduria and homocystinuria. MMACHC can interact with cyanocobalamin (a type of vitamin B12) cofactor and plays an important role in targeting cyanocobalamin to the enzyme of interest. In this paper, the GST-tag fusion-tagged MMACHC protein was successfully expressed by Escherichia coli (E. coli) low-temperature induction, and the high-purity MMACHC protein was successfully purified by affinity chromatography and gel filtration. Further, the crystal structure of MMACHC and cyanocobalamin complex was obtained with a resolution of 1.93 Å using X-ray diffraction. By analysing the complex structure of MMACHC and cyanocobalamin, we revealed the reasons for the diversity of MMACHC substrates and explained the reasons for the differences in disease conditions caused by different MMACHC site mutations. The acquisition of the complex structure of MMACHC and cyanocobalamin will play a significant role in promoting research on the metabolic pathway of vitamin B12.
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Guéant JL, Guéant-Rodriguez RM, Kosgei VJ, Coelho D. Causes and consequences of impaired methionine synthase activity in acquired and inherited disorders of vitamin B 12 metabolism. Crit Rev Biochem Mol Biol 2021; 57:133-155. [PMID: 34608838 DOI: 10.1080/10409238.2021.1979459] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Methyl-Cobalamin (Cbl) derives from dietary vitamin B12 and acts as a cofactor of methionine synthase (MS) in mammals. MS encoded by MTR catalyzes the remethylation of homocysteine to generate methionine and tetrahydrofolate, which fuel methionine and cytoplasmic folate cycles, respectively. Methionine is the precursor of S-adenosyl methionine (SAM), the universal methyl donor of transmethylation reactions. Impaired MS activity results from inadequate dietary intake or malabsorption of B12 and inborn errors of Cbl metabolism (IECM). The mechanisms at the origin of the high variability of clinical presentation of impaired MS activity are classically considered as the consequence of the disruption of the folate cycle and related synthesis of purines and pyrimidines and the decreased synthesis of endogenous methionine and SAM. For one decade, data on cellular and animal models of B12 deficiency and IECM have highlighted other key pathomechanisms, including altered interactome of MS with methionine synthase reductase, MMACHC, and MMADHC, endoplasmic reticulum stress, altered cell signaling, and genomic/epigenomic dysregulations. Decreased MS activity increases catalytic protein phosphatase 2A (PP2A) and produces imbalanced phosphorylation/methylation of nucleocytoplasmic RNA binding proteins, including ELAVL1/HuR protein, with subsequent nuclear sequestration of mRNAs and dramatic alteration of gene expression, including SIRT1. Decreased SAM and SIRT1 activity induce ER stress through impaired SIRT1-deacetylation of HSF1 and hypomethylation/hyperacetylation of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α), which deactivate nuclear receptors and lead to impaired energy metabolism and neuroplasticity. The reversibility of these pathomechanisms by SIRT1 agonists opens promising perspectives in the treatment of IECM outcomes resistant to conventional supplementation therapies.
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Affiliation(s)
- Jean-Louis Guéant
- UMR Inserm 1256 N-GERE (Nutrition, Génetique et Exposition aux Risques Environmentaux), Université de Lorraine, Vandoeuvre-lès-Nancy, France.,Departments of Digestive Diseases and Molecular Medicine and National Center of Inborn Errors of Metabolism, University Hospital Center, Université de Lorraine, Vandoeuvre-lès-Nancy, France
| | - Rosa-Maria Guéant-Rodriguez
- UMR Inserm 1256 N-GERE (Nutrition, Génetique et Exposition aux Risques Environmentaux), Université de Lorraine, Vandoeuvre-lès-Nancy, France.,Departments of Digestive Diseases and Molecular Medicine and National Center of Inborn Errors of Metabolism, University Hospital Center, Université de Lorraine, Vandoeuvre-lès-Nancy, France
| | - Viola J Kosgei
- UMR Inserm 1256 N-GERE (Nutrition, Génetique et Exposition aux Risques Environmentaux), Université de Lorraine, Vandoeuvre-lès-Nancy, France
| | - David Coelho
- UMR Inserm 1256 N-GERE (Nutrition, Génetique et Exposition aux Risques Environmentaux), Université de Lorraine, Vandoeuvre-lès-Nancy, France
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Mosca P, Robert A, Alberto JM, Meyer M, Kundu U, Hergalant S, Umoret R, Coelho D, Guéant JL, Leheup B, Dreumont N. Vitamin B 12 Deficiency Dysregulates m6A mRNA Methylation of Genes Involved in Neurological Functions. Mol Nutr Food Res 2021; 65:e2100206. [PMID: 34291881 DOI: 10.1002/mnfr.202100206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 07/05/2021] [Indexed: 11/12/2022]
Abstract
INTRODUCTION Vitamin B12 deficiency presents various neurological manifestations, such as cognitive dysfunction, mental retardation, or memory impairment. However, the involved molecular mechanisms remain to date unclear. Vitamin B12 is essential for synthesizing S-adenosyl methionine (SAM), the methyl group donor used for almost all transmethylation reactions. Here, we investigate the m6A methylation of mRNAs and their related gene expression in models of vitamin B12 deficiency. METHODS AND RESULTS This study observes two cellular models deficient in vitamin B12 and hippocampi of mice knock-out for the CD320 receptor. The decrease in SAM levels resulting from vitamin B12 deficiency is associated with m6 A reduced levels in mRNAs. This is also potentially mediated by the overexpression of the eraser FTO. We further investigate mRNA methylation of some genes involved in neurological functions targeted by the m6A reader YTH proteins. We notably observe a m6A hypermethylation of Prkca mRNA and a consistently increased expression of PKCα, a kinase involved in brain development and neuroplasticity, in the two cellular models. CONCLUSION Our data show that m6A methylation in mRNA could be one of the contributing mechanisms that underlie the neurological manifestations produced by vitamin B12 deficiency.
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Affiliation(s)
- Pauline Mosca
- Université de Lorraine, Inserm, NGERE, Nancy, F-54000, France
| | - Aurélie Robert
- Université de Lorraine, Inserm, NGERE, Nancy, F-54000, France
| | | | - Marie Meyer
- Université de Lorraine, Inserm, NGERE, Nancy, F-54000, France
| | - Urbi Kundu
- Université de Lorraine, Inserm, NGERE, Nancy, F-54000, France
| | | | - Rémy Umoret
- Université de Lorraine, Inserm, NGERE, Nancy, F-54000, France
| | - David Coelho
- Université de Lorraine, Inserm, NGERE, Nancy, F-54000, France
| | | | - Bruno Leheup
- Université de Lorraine, Inserm, NGERE, Nancy, F-54000, France
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