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Thewissen RMJ, Post MA, Maas DM, Veizaj R, Wagenaar I, Alsady M, Kools J, Bouman K, Zweers H, Meregalli PG, van der Kooi AJ, van Doorn PA, Groothuis JT, Lefeber DJ, Voermans NC. Oral ribose supplementation in dystroglycanopathy: A single case study. JIMD Rep 2024; 65:171-181. [PMID: 38736632 PMCID: PMC11078721 DOI: 10.1002/jmd2.12394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 05/14/2024] Open
Abstract
Three forms of muscular dystrophy-dystroglycanopathies are linked to the ribitol pathway. These include mutations in the isoprenoid synthase domain-containing protein (ISPD), fukutin-related protein (FKRP), and fukutin (FKTN) genes. The aforementioned enzymes are required for generation of the ribitol phosphate linkage in the O-glycan of alpha-dystroglycan. Mild cases of dystroglycanopathy present with slowly progressive muscle weakness, while in severe cases the eyes and brain are also involved. Previous research showed that ribose increased the intracellular concentrations of cytidine diphosphate-ribitol (CDP-ribitol) and had a therapeutic effect. Here, we report the safety and effects of oral ribose supplementation during 6 months in a patient with limb girdle muscular dystrophy type 2I (LGMD2I) due to a homozygous FKRP mutation. Ribose was well tolerated in doses of 9 g or 18 g/day. Supplementation with 18 g of ribose resulted in a decrease of creatine kinase levels of 70%. Moreover, metabolomics showed a significant increase in CDP-ribitol levels with 18 g of ribose supplementation (p < 0.001). Although objective improvement in clinical and patient-reported outcome measures was not observed, the patient reported subjective improvement of muscle strength, fatigue, and pain. This case study indicates that ribose supplementation in patients with dystroglycanopathy is safe and highlights the importance for future studies regarding its potential effects.
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Affiliation(s)
- R. M. J. Thewissen
- Department of NeurologyDonders Institute for Brain, Cognition and Behavior, Radboud University Medical CenterNijmegenThe Netherlands
| | - M. A. Post
- Department of NeurologyDonders Institute for Brain, Cognition and Behavior, Radboud University Medical CenterNijmegenThe Netherlands
| | - D. M. Maas
- Department of RehabilitationDonders Institute for Brain, Cognition and Behavior, Radboud University Medical CenterNijmegenThe Netherlands
| | - R. Veizaj
- Translational Metabolic Laboratory, Department of Laboratory MedicineRadboud University Medical CenterNijmegenThe Netherlands
| | - I. Wagenaar
- Translational Metabolic Laboratory, Department of Laboratory MedicineRadboud University Medical CenterNijmegenThe Netherlands
| | - M. Alsady
- Department of NeurologyDonders Institute for Brain, Cognition and Behavior, Radboud University Medical CenterNijmegenThe Netherlands
| | - J. Kools
- Department of NeurologyDonders Institute for Brain, Cognition and Behavior, Radboud University Medical CenterNijmegenThe Netherlands
| | - K. Bouman
- Department of NeurologyDonders Institute for Brain, Cognition and Behavior, Radboud University Medical CenterNijmegenThe Netherlands
- Department of Pediatric NeurologyDonders Institute for Brain, Cognition and Behavior, Amalia Children's Hospital, Radboud University Medical CenterNijmegenThe Netherlands
| | - H. Zweers
- Department of GastroenterologyRadboud University Medical CenterNijmegenThe Netherlands
| | - P. G. Meregalli
- Department of CardiologyAmsterdam UMCAmsterdamThe Netherlands
| | | | | | - J. T. Groothuis
- Department of RehabilitationDonders Institute for Brain, Cognition and Behavior, Radboud University Medical CenterNijmegenThe Netherlands
| | - D. J. Lefeber
- Department of NeurologyDonders Institute for Brain, Cognition and Behavior, Radboud University Medical CenterNijmegenThe Netherlands
- Translational Metabolic Laboratory, Department of Laboratory MedicineRadboud University Medical CenterNijmegenThe Netherlands
| | - N. C. Voermans
- Department of NeurologyDonders Institute for Brain, Cognition and Behavior, Radboud University Medical CenterNijmegenThe Netherlands
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Unnikrishnan G, Polavarapu K, Bardhan M, Nashi S, Vengalil S, Preethish-Kumar V, Valasani RK, Huddar A, Nishadham V, Nandeesh BN, Nalini A. Phenotype Genotype Characterization of FKRP-related Muscular Dystrophy among Indian Patients. J Neuromuscul Dis 2023:JND221618. [PMID: 37154180 DOI: 10.3233/jnd-221618] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
BACKGROUND The phenotypic spectrum of Fukutin-related protein (FKRP) mutations is highly variable and comprises of limb girdle muscular dystrophy (LGMD) R9 (previously LGMD 2I) and FKRP related congenital muscular dystrophies. OBJECTIVE To identify the distinct genotype phenotype pattern in Indian patients with FKRP gene mutations. METHODS We retrospectively reviewed the case files of patients with muscular dystrophy having a genetically confirmed FKRP mutation. All patients had undergone genetic testing using next-generation sequencing. RESULTS Our patients included five males and four females presenting between 1.5 years and seven years of age (median age - 3 years). The initial symptom was a delayed acquisition of gross motor developmental milestones in seven patients and recurrent falls and poor sucking in one patient each. Two patients had a language delay, with both having abnormalities on the brain MRI. Macroglossia, scapular winging, and facial weakness were noted in one, three and four patients respectively. Calf muscle hypertrophy was seen in eight patients and ankle contractures in six. At the last follow-up, three patients had lost ambulation (median age - 7 years; range 6.5-9 years) and three patients had not attained independent ambulation. Creatine kinase levels ranged between 2793 and 32,396 U/L (mean 12,120 U/L). A common mutation - c.1343C>T was noted in 5 patients in our cohort. Additionally, four novel mutations were identified. Overall, six patients had an LGMD R9 phenotype, and three had a congenital muscular dystrophy phenotype. CONCLUSION Patients with FKRP mutations can have varied presentations. A Duchenne-like phenotype was the most commonly encountered pattern in our cohort, with c.1343C>T being the most common mutation.
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Affiliation(s)
| | - Kiran Polavarapu
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Mainak Bardhan
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Saraswati Nashi
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Seena Vengalil
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | | | - Ravi Kiran Valasani
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Akshata Huddar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Vikas Nishadham
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | | | - Atchayaram Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
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Gaertner A, Burr L, Klauke B, Brodehl A, Laser KT, Klingel K, Tiesmeier J, Schulz U, zu Knyphausen E, Gummert J, Milting H. Compound Heterozygous FKTN Variants in a Patient with Dilated Cardiomyopathy Led to an Aberrant α-Dystroglycan Pattern. Int J Mol Sci 2022; 23:ijms23126685. [PMID: 35743126 PMCID: PMC9223741 DOI: 10.3390/ijms23126685] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 02/01/2023] Open
Abstract
Fukutin encoded by FKTN is a ribitol 5-phosphate transferase involved in glycosylation of α-dystroglycan. It is known that mutations in FKTN affect the glycosylation of α-dystroglycan, leading to a dystroglycanopathy. Dystroglycanopathies are a group of syndromes with a broad clinical spectrum including dilated cardiomyopathy and muscular dystrophy. In this study, we reported the case of a patient with muscular dystrophy, early onset dilated cardiomyopathy, and elevated creatine kinase levels who was a carrier of the compound heterozygous variants p.Ser299Arg and p.Asn442Ser in FKTN. Our work showed that compound heterozygous mutations in FKTN lead to a loss of fully glycosylated α-dystroglycan and result in cardiomyopathy and end-stage heart failure at a young age.
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Affiliation(s)
- Anna Gaertner
- Erich und Hanna Klessmann-Institut für Kardiovaskuläre Forschung und Entwicklung, Klinik für Thorax- und Kardiovaskularchirurgie, Herz und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (L.B.); (B.K.); (A.B.); (J.T.); (U.S.); (J.G.)
- Correspondence: (A.G.); (H.M.)
| | - Lidia Burr
- Erich und Hanna Klessmann-Institut für Kardiovaskuläre Forschung und Entwicklung, Klinik für Thorax- und Kardiovaskularchirurgie, Herz und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (L.B.); (B.K.); (A.B.); (J.T.); (U.S.); (J.G.)
| | - Baerbel Klauke
- Erich und Hanna Klessmann-Institut für Kardiovaskuläre Forschung und Entwicklung, Klinik für Thorax- und Kardiovaskularchirurgie, Herz und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (L.B.); (B.K.); (A.B.); (J.T.); (U.S.); (J.G.)
| | - Andreas Brodehl
- Erich und Hanna Klessmann-Institut für Kardiovaskuläre Forschung und Entwicklung, Klinik für Thorax- und Kardiovaskularchirurgie, Herz und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (L.B.); (B.K.); (A.B.); (J.T.); (U.S.); (J.G.)
| | - Kai Thorsten Laser
- Zentrum für Angeborene Herzfehler, Herz und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (K.T.L.); (E.z.K.)
| | - Karin Klingel
- Kardiopathologie, Institut für Pathologie und Neuropathologie, Universitätsklinikum Tübingen, Liebermeisterstraße 8, 72076 Tübingen, Germany;
| | - Jens Tiesmeier
- Erich und Hanna Klessmann-Institut für Kardiovaskuläre Forschung und Entwicklung, Klinik für Thorax- und Kardiovaskularchirurgie, Herz und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (L.B.); (B.K.); (A.B.); (J.T.); (U.S.); (J.G.)
| | - Uwe Schulz
- Erich und Hanna Klessmann-Institut für Kardiovaskuläre Forschung und Entwicklung, Klinik für Thorax- und Kardiovaskularchirurgie, Herz und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (L.B.); (B.K.); (A.B.); (J.T.); (U.S.); (J.G.)
| | - Edzard zu Knyphausen
- Zentrum für Angeborene Herzfehler, Herz und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (K.T.L.); (E.z.K.)
| | - Jan Gummert
- Erich und Hanna Klessmann-Institut für Kardiovaskuläre Forschung und Entwicklung, Klinik für Thorax- und Kardiovaskularchirurgie, Herz und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (L.B.); (B.K.); (A.B.); (J.T.); (U.S.); (J.G.)
| | - Hendrik Milting
- Erich und Hanna Klessmann-Institut für Kardiovaskuläre Forschung und Entwicklung, Klinik für Thorax- und Kardiovaskularchirurgie, Herz und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (L.B.); (B.K.); (A.B.); (J.T.); (U.S.); (J.G.)
- Correspondence: (A.G.); (H.M.)
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Tamura JI, Tamura T, Hoshino S, Imae R, Kato R, Yokono M, Nagase M, Ohno S, Manabe N, Yamaguchi Y, Manya H, Endo T. Chemical and Chemo-Enzymatic Syntheses of Glycans Containing Ribitol Phosphate Scaffolding of Matriglycan. ACS Chem Biol 2022; 17:1513-1523. [PMID: 35670527 DOI: 10.1021/acschembio.2c00181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ribitol phosphate modifications to the core M3 O-mannosyl glycan are important for the functional maturation of α-dystroglycan. Three sequentially extended partial structures of the core M3 O-mannosyl glycan including a tandem ribitol phosphate were regio- and stereo-selectively synthesized: Rbo5P-3GalNAcβ, Rbo5P-1Rbo5P-3GalNAcβ, and Xylβ1-4Rbo5P-1Rbo5P-3GalNAcβ (Rbo5P, d-ribitol-5-phosphate; GalNAc, N-acetyl-d-galactosamine; Xyl, d-xylose). Rbo5P-3GalNAcβ with p-nitrophenyl at the aglycon part served as a substrate for ribitol phosphate transferase (FKRP, fukutin-related protein), and its product was glycosylated by the actions of a series of glycosyltransferases, namely, ribitol xylosyltransferase 1 (RXYLT1), β1,4-glucuronyltransferase 1 (B4GAT1), and like-acetyl-glucosaminyltransferase (LARGE). Rbo5P-3GalNAcβ equipped with an alkyne-type aglycon was also active for FKRP. The molecular information obtained on FKRP suggests that Rbo5P-3GalNAcβ derivatives are the minimal units required as the acceptor glycan for Rbo5P transfer and may serve as a precursor for the elongation of the core M3 O-mannosyl glycan.
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Affiliation(s)
- Jun-Ichi Tamura
- The United Graduate School of Agricultural Sciences, Tottori University, Tottori 680-8553, Japan
| | - Takahiro Tamura
- The United Graduate School of Agricultural Sciences, Tottori University, Tottori 680-8553, Japan
| | - Shunsuke Hoshino
- Molecular Glycobiology, Research Team for Mechanism of Aging, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan
| | - Rieko Imae
- Molecular Glycobiology, Research Team for Mechanism of Aging, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan
| | - Ryuichi Kato
- Structural Biology Research Center, Institute of Material Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan
| | - Mizuki Yokono
- Technical Department, Tottori University, Tottori 680-8550, Japan
| | - Mao Nagase
- Division of Structural Glycobiology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai 981-8558, Japan
| | - Shiho Ohno
- Division of Structural Glycobiology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai 981-8558, Japan
| | - Noriyoshi Manabe
- Division of Structural Glycobiology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai 981-8558, Japan
| | - Yoshiki Yamaguchi
- Division of Structural Glycobiology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai 981-8558, Japan
| | - Hiroshi Manya
- Molecular Glycobiology, Research Team for Mechanism of Aging, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan
| | - Tamao Endo
- Molecular Glycobiology, Research Team for Mechanism of Aging, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan
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5
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Expanding the Phenotype of B3GALNT2-Related Disorders. Genes (Basel) 2022; 13:genes13040694. [PMID: 35456500 PMCID: PMC9024883 DOI: 10.3390/genes13040694] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 04/13/2022] [Indexed: 11/16/2022] Open
Abstract
Dystroglycanopathies are a group of congenital muscular dystrophies (CMDs) that include a broad phenotypic spectrum ranging from late-onset limb-girdle muscular dystrophy to severe muscle–eye–brain disease, Walker–Warburg syndrome, and Fukuyama congenital muscular dystrophy. In addition to clinical heterogeneity, CMDs are characterized by genetic heterogeneity. To date, 18 genes have been associated with CMDs. One of them is B3GALNT2, which encodes the β-1,3-N-acetylgalactosaminyltransferase 2 that glycosylates α-dystroglycan. In this study, using exome sequencing, we identify a homozygous frameshift variant in B3GALNT2 due to a mixed uniparental disomy of chromosome 1 in a 7-year-old girl with global developmental delay, severely delayed active language development, and autism spectrum disorder but without any symptoms of muscular dystrophy. In addition to this case, we also provide an overview of all previously reported cases, further expanding the phenotypic spectrum.
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Tamura T, Omura Y, Kotera K, Ito R, Ohno S, Manabe N, Yamaguchi Y, Tamura JI. Synthesis of the matriglycan hexasaccharide, -3Xylα1-3GlcAβ1-trimer and its interaction with laminin. Org Biomol Chem 2022; 20:8489-8500. [DOI: 10.1039/d2ob01388f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Matriglycan hexasaccharide (-3Xylα1-3GlcAβ1)3-O(C2H4O)3CH2CCH and the biotin conjugate was synthesized. The hexasaccharide showed good interaction with laminin-G-like domains 4 and 5 of laminin-α2 using saturation transfer difference-NMR and bio-layer interferometry.
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Affiliation(s)
- Takahiro Tamura
- The United Graduate School of Agricultural Sciences, Tottori University, Tottori, 680-8553 Japan
| | - Yuka Omura
- Department of Agricultural, life and Environmental Sciences, Faculty of Agriculture, Tottori University, Tottori, 680-8553 Japan
| | - Kota Kotera
- Department of Agricultural, life and Environmental Sciences, Faculty of Agriculture, Tottori University, Tottori, 680-8553 Japan
| | - Ryota Ito
- Division of Structural Glycobiology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, 981-8558 Japan
| | - Shiho Ohno
- Division of Structural Glycobiology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, 981-8558 Japan
| | - Noriyoshi Manabe
- Division of Structural Glycobiology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, 981-8558 Japan
| | - Yoshiki Yamaguchi
- Division of Structural Glycobiology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, Sendai, 981-8558 Japan
| | - Jun-ichi Tamura
- The United Graduate School of Agricultural Sciences, Tottori University, Tottori, 680-8553 Japan
- Department of Agricultural, life and Environmental Sciences, Faculty of Agriculture, Tottori University, Tottori, 680-8553 Japan
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7
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Kanagawa M. Dystroglycanopathy: From Elucidation of Molecular and Pathological Mechanisms to Development of Treatment Methods. Int J Mol Sci 2021; 22:ijms222313162. [PMID: 34884967 PMCID: PMC8658603 DOI: 10.3390/ijms222313162] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 01/13/2023] Open
Abstract
Dystroglycanopathy is a collective term referring to muscular dystrophies with abnormal glycosylation of dystroglycan. At least 18 causative genes of dystroglycanopathy have been identified, and its clinical symptoms are diverse, ranging from severe congenital to adult-onset limb-girdle types. Moreover, some cases are associated with symptoms involving the central nervous system. In the 2010s, the structure of sugar chains involved in the onset of dystroglycanopathy and the functions of its causative gene products began to be identified as if they were filling the missing pieces of a jigsaw puzzle. In parallel with these discoveries, various dystroglycanopathy model mice had been created, which led to the elucidation of its pathological mechanisms. Then, treatment strategies based on the molecular basis of glycosylation began to be proposed after the latter half of the 2010s. This review briefly explains the sugar chain structure of dystroglycan and the functions of the causative gene products of dystroglycanopathy, followed by introducing the pathological mechanisms involved as revealed from analyses of dystroglycanopathy model mice. Finally, potential therapeutic approaches based on the pathological mechanisms involved are discussed.
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Affiliation(s)
- Motoi Kanagawa
- Department of Cell Biology and Molecular Medicine, Graduate School of Medicine, Ehime University, 454 Shitsukawa, Toon 791-0295, Ehime, Japan
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8
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Iivonen AP, Kärkinen J, Yellapragada V, Sidoroff V, Almusa H, Vaaralahti K, Raivio T. Kallmann syndrome in a patient with Weiss-Kruszka syndrome and a de novo deletion in 9q31.2. Eur J Endocrinol 2021; 185:57-66. [PMID: 33909591 PMCID: PMC8183635 DOI: 10.1530/eje-20-1387] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 04/28/2021] [Indexed: 12/21/2022]
Abstract
Patients with deletions on chromosome 9q31.2 may exhibit delayed puberty, craniofacial phenotype including cleft lip/palate, and olfactory bulb hypoplasia. We report a patient with congenital HH with anosmia (Kallmann syndrome, KS) and a de novo 2.38 Mb heterozygous deletion in 9q31.2. The deletion breakpoints (determined with whole-genome linked-read sequencing) were in the FKTN gene (9:108,331,353) and in a non-coding area (9:110,707,332) (hg19). The deletion encompassed six protein-coding genes (FKTN, ZNF462, TAL2, TMEM38B, RAD23B, and KLF4). ZNF462 haploinsufficiency was consistent with the patient's Weiss-Kruszka syndrome (craniofacial phenotype, developmental delay, and sensorineural hearing loss), but did not explain his KS. In further analyses, he did not carry rare sequence variants in 32 known KS genes in whole-exome sequencing and displayed no aberrant splicing of 15 KS genes that were expressed in peripheral blood leukocyte transcriptome. The deletion was 1.8 Mb upstream of a KS candidate gene locus (PALM2AKAP2) but did not suppress its expression. In conclusion, this is the first report of a patient with Weiss-Kruszka syndrome and KS. We suggest that patients carrying a microdeletion in 9q31.2 should be evaluated for the presence of KS and KS-related features.
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Affiliation(s)
- Anna-Pauliina Iivonen
- Department of Physiology, Stem Cells and Metabolism Research Program, Faculty of Medicine, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Juho Kärkinen
- Pediatric Research Center, New Children’s Hospital, Helsinki University Hospital, Helsinki, Finland
| | - Venkatram Yellapragada
- Department of Physiology, Stem Cells and Metabolism Research Program, Faculty of Medicine, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | | | - Henrikki Almusa
- Institute for Molecular Medicine Finland, FIMM, University of Helsinki, Helsinki, Finland
| | - Kirsi Vaaralahti
- Department of Physiology, Stem Cells and Metabolism Research Program, Faculty of Medicine, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Taneli Raivio
- Department of Physiology, Stem Cells and Metabolism Research Program, Faculty of Medicine, Research Programs Unit, University of Helsinki, Helsinki, Finland
- Pediatric Research Center, New Children’s Hospital, Helsinki University Hospital, Helsinki, Finland
- Correspondence should be addressed to T Raivio;
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9
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Kölbel H, Preuße C, Brand L, von Moers A, Della Marina A, Schuelke M, Roos A, Goebel HH, Schara-Schmidt U, Stenzel W. Inflammation, fibrosis and skeletal muscle regeneration in LGMDR9 are orchestrated by macrophages. Neuropathol Appl Neurobiol 2021; 47:856-866. [PMID: 33973272 DOI: 10.1111/nan.12730] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/03/2021] [Accepted: 05/01/2021] [Indexed: 11/29/2022]
Abstract
AIMS Variable degrees of inflammation, necrosis, regeneration and fibrofatty replacement are part of the pathological spectrum of the dystrophic process in alpha dystroglycanopathy LGMDR9 (FKRP-related, OMIM #607155), one of the most prevailing types of LGMDs worldwide. Inflammatory processes and their complex interplay with vascular, myogenic and mesenchymal cells may have a major impact on disease development. The purpose of our study is to describe the specific immune morphological features in muscle tissue of patients with LGMDR9 to enable a better understanding of the phenotype of muscle damage leading to disease progression. METHODS We have analysed skeletal muscle biopsies of 17 patients genetically confirmed as having LGMDR9 by histopathological and molecular techniques. RESULTS We identified CD206+ MHC class II+ and STAT6+ immune-repressed macrophages dominating the endomysial infiltrate in areas of myofibre regeneration and fibrosis. Additionally, PDGFRβ+ pericytes were located around MHC class II+ activated capillaries residing in close proximity to areas of fibrosis and regenerating fibres. Expression of VEGF was found on many regenerating neonatal myosin+ fibres, myofibres and CD206+ macrophages also co-expressed VEGF. CONCLUSION Our results show characteristic immune inflammatory features in LGMDR9 and more specifically shed light on the predominant role of macrophages and their function in vascular organisation, fibrosis and myogenesis. Understanding disease-specific immune phenomena potentially inform about possibilities for anti-fibrotic and anti-inflammatory therapeutic strategies, which may complement Ribitol replacement and gene therapies for LGMDR9 that may be available in the future.
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Affiliation(s)
- Heike Kölbel
- Department of Neuropaediatrics, Neuromuscular Centre, Universitätsmedizin Essen, Germany
| | - Corinna Preuße
- Department of Neuropathology, Charité - Universitätsmedizin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Neurology with Institute for Translational Neurology, University Hospital Münster, Münster, Germany
| | - Lukas Brand
- Department of Neuropaediatrics, Neuromuscular Centre, Universitätsmedizin Essen, Germany
| | - Arpad von Moers
- Department of Paediatrics and Neuropaediatrics, DRK Klinikum Westend, Berlin, Germany
| | - Adela Della Marina
- Department of Neuropaediatrics, Neuromuscular Centre, Universitätsmedizin Essen, Germany
| | - Markus Schuelke
- Department of Neuropediatrics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andreas Roos
- Department of Neuropaediatrics, Neuromuscular Centre, Universitätsmedizin Essen, Germany
| | - Hans-Hilmar Goebel
- Department of Neuropathology, Charité - Universitätsmedizin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Neuropathology, Universitätsmedizin Mainz, Germany
| | - Ulrike Schara-Schmidt
- Department of Neuropaediatrics, Neuromuscular Centre, Universitätsmedizin Essen, Germany
| | - Werner Stenzel
- Department of Neuropathology, Charité - Universitätsmedizin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
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10
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Alharbi S, Alhashem A, Alkuraya F, Kashlan F, Tlili-Graiess K. Neuroimaging manifestations and genetic heterogeneity of Walker-Warburg syndrome in Saudi patients. Brain Dev 2021; 43:380-388. [PMID: 33199158 DOI: 10.1016/j.braindev.2020.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 10/08/2020] [Accepted: 10/25/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Walker-Warburg syndrome (WWS), an autosomal recessive disease, is the most severe phenotype of congenital muscular dystrophies. Its diagnosis remains primarily clinical and radiological. Identification of its causative variants will assist genetic counseling. We aim to describe genetic and neuroimaging findings of WWS and investigate the correlation between them. METHODS We retrospectively reviewed the clinical, genetic and neuroimaging findings of eleven Saudi neonates diagnosed with WWS between April 2012 and December 2018 in a single tertiary care center. Correlation between neuroimaging and genetic findings was investigated. RESULTS All patients had macrocephaly except one who had intrauterine growth restriction. Dysmorphic features were identified in nearly half of the patients. Creatine kinase levels were available in nine patients and were always elevated. Homozygous pathogenic variants were identified in all patients spanning POMT1 (n = 5), TMEM5 (n = 3), ISPD (n = 2) and POMT2 (n = 1) including one patient who had a dual molecular diagnosis of ISPD and PGAP2. On neuroimaging, all patients showed cobblestone cortex, classical infratentorial findings, and hydrocephalus. Other cerebral cortical malformations included subependymal heterotopia, polymicrogyria and open-lip schizencephaly in four, two and one patients, respectively. Buphthalmos and microphthalmia were the most prevalent orbital findings and found in all patients either unilaterally or bilaterally. CONCLUSION WWS is a genetically heterogeneous disorder among Saudis. The case with an additional PGAP2-related phenotype exemplifies the increased risk of dual autosomal recessive disorders in consanguineous populations. MRI is excellent in demonstrating spectrum of WWS brain and orbital malformations; however, no definite correlation could be found between the MRI findings and the genetic variant.
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Affiliation(s)
- Sara Alharbi
- Neuroradiology Section, Department of Radiology, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Amal Alhashem
- Division of Genetics, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Fowzan Alkuraya
- Division of Genetics, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia; Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia; Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fawaz Kashlan
- Division of Neonatology, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Kalthoum Tlili-Graiess
- Neuroradiology Section, Department of Radiology, Prince Sultan Military Medical City, Riyadh, Saudi Arabia.
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11
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Song D, Dai Y, Chen X, Fu X, Chang X, Wang N, Zhang C, Yan C, Zheng H, Wu L, Jiang L, Hua Y, Yang H, Wang Z, Dai T, Zhu W, Han C, Yuan Y, Kobayashi K, Toda T, Xiong H. Genetic variations and clinical spectrum of dystroglycanopathy in a large cohort of Chinese patients. Clin Genet 2021; 99:384-395. [PMID: 33200426 DOI: 10.1111/cge.13886] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/27/2020] [Accepted: 11/12/2020] [Indexed: 12/18/2022]
Abstract
Dystroglycanopathy is a group of muscular dystrophies with deficient glycosylation of alpha-dystroglycan (α-DG). We recruited patients from 36 tertiary academic hospitals in China. In total, 143 patients with genetically diagnosed dystroglycanopathy were enrolled. Of these, limb girdle muscular dystrophy was the most common initial diagnosis (83 patients) and Walker-Warburg syndrome was the least common (1 patient). In 143 patients, mutations in FKRP gene were the most prevalent (62 patients), followed by POMT2, POMT1 (16), POMGNT1, ISPD (14), FKTN, GMPPB, B3GALNT2, DPM3, and DAG1. Several frequent mutations were identified in FKRP, POMT1, POMGNT1, ISPD, and FKTN genes. Many of these were founder mutations. Patients with FKRP mutations tended to have milder phenotypes, while those with mutations in POMGNT1 genes had more severe phenotypes. Mental retardation was a clinical feature associated with mutations of POMT1 gene. Detailed clinical data of 83 patients followed up in Peking University First Hospital were further analyzed. Our clinical and genetic analysis of a large cohort of Chinese patients with dystroglycanopathy expanded the genotype variation and clinical spectrum of congenital muscular dystrophies.
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Affiliation(s)
- Danyu Song
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yi Dai
- Department of Neurology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaoyu Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiaona Fu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xingzhi Chang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Ning Wang
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Cheng Zhang
- Department of Neurology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Chuanzhu Yan
- Department of Neurology, Qilu Hospital, Shandong University, Jinan, China
| | - Hong Zheng
- Department of Pediatrics, the First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, China
| | - Liwen Wu
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Li Jiang
- Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Ying Hua
- Department of Neurology, Wuxi Children's Hospital, Wuxi, China
| | - Haipo Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zhiqiang Wang
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Tingjun Dai
- Department of Neurology, Qilu Hospital, Shandong University, Jinan, China
| | - Wenhua Zhu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Chunxi Han
- Department of Neurology, Shenzhen Children's Hospital, Shenzhen, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Kazuhiro Kobayashi
- Division of Neurology/Molecular Brain Science, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tatsushi Toda
- Department of Neurology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
| | - Hui Xiong
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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12
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Tamura T, Omura Y, Tamura JI. Stereo- and Regioselective Synthesis of O-Mannosyl Glycan Containing Matriglycan and a Part of Tandem Ribitol Phosphate. J Org Chem 2020; 85:12935-12946. [PMID: 32930586 DOI: 10.1021/acs.joc.0c01569] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We herein successfully synthesized two pivotal structures of O-mannosyl glycan: (1) the matriglycan-repeating tetrasaccharide Xylα1-3GlcAβ1-3Xylα1-3GlcAβ and (2) the link between matriglycan and a part of tandem ribitol phosphate, Xylα1-3GlcAβ1-4Xylβ1-4Rbo, in a regio- and stereocontrolled manner. The disaccharide unit with the α-linkage of xylose was obtained by adopting the conformational fixation of the xylopyranoside ring and a specific solvation system of diastereoselective solubility.
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Affiliation(s)
- Takahiro Tamura
- The United Graduate School of Agricultural Sciences, Tottori University, Tottori 680-8553, Japan
| | - Yuka Omura
- Graduate School of Sustainability Science, Department of Agricultural Science, Tottori University, Tottori 680-8553, Japan
| | - Jun-Ichi Tamura
- The United Graduate School of Agricultural Sciences, Tottori University, Tottori 680-8553, Japan.,Graduate School of Sustainability Science, Department of Agricultural Science, Tottori University, Tottori 680-8553, Japan
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13
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Mohamadian M, Naseri M, Ghandil P, Bahrami A, Momen AA. The first report of two homozygous sequence variants in FKRP and SELENON genes associated with syndromic congenital muscular dystrophy in Iran: Further expansion of the clinical phenotypes. J Gene Med 2020; 22:e3265. [PMID: 32864802 DOI: 10.1002/jgm.3265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 07/11/2020] [Accepted: 08/22/2020] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Congenital muscular dystrophy (CMD) refers to hypotonia and delayed motor development that is manifested at or near the birth. Additional presentations have been observed in CMD syndromes. METHODS Thorough clinical examinations were performed on two unrelated Iranian families with typical symptoms of CMD and uncommon features such as intellectual disability and nephrolithiasis. The genomic DNA of probands were subjected to whole exome sequencing. Following the detection of candidate variants with a bioinformatic pipeline, the familial co-segregation analysis was carried out using polymerase chain reaction-based Sanger sequencing. RESULTS We identified a missense homozygous variant in the fukutin-related protein (FKRP) gene (c.968G>A, p.Arg323His) related to CMD-dystroglycanopathy type B5 (MDDGB5) and a frameshift homozygous variant in the selenoprotein N (SELENON) gene (c.1446delC, p.Asn483Thrfs*11) associated with congenital rigid-spine muscular dystrophy 1 (RSMD1), which were completely segregated with the phenotypes in the families. These variants were not found in either the 1000 Genomes Project or the Exome Aggregation Consortium. The present study provides the first report of these homozygous sequence variants in Iran. Moreover, our study was the first observation of nephrolithiasis in FKRP-related dystroglycanopathy and intellectual disability in SELENON-related myopathies. Based on in silico studies and molecular docking, these variations induced pathogenic effects on the proteins. CONCLUSIONS Our findings extend the genetic database of Iranian patients with CMD and, in general, the phenotypical spectrum of syndromic CMD. It is recommended to consider these variants for a more accurate clinical interpretation, prenatal diagnosis and genetic counseling in families with a history of CMD, especially in those combined with cognitive impairments or renal dysfunctions.
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Affiliation(s)
- Malihe Mohamadian
- Department of Molecular Medicine, Birjand University of Medical Sciences, Birjand, Iran
| | - Mohsen Naseri
- Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Pegah Ghandil
- Diabetes Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Medical Genetics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Afsane Bahrami
- Cellular and Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Ali Akbar Momen
- Department of Paediatric Neurology, Golestan Medical, Educational, and Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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14
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Congenital hearing impairment associated with peripheral cochlear nerve dysmyelination in glycosylation-deficient muscular dystrophy. PLoS Genet 2020; 16:e1008826. [PMID: 32453729 PMCID: PMC7274486 DOI: 10.1371/journal.pgen.1008826] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 06/05/2020] [Accepted: 05/04/2020] [Indexed: 02/06/2023] Open
Abstract
Hearing loss (HL) is one of the most common sensory impairments and etiologically and genetically heterogeneous disorders in humans. Muscular dystrophies (MDs) are neuromuscular disorders characterized by progressive degeneration of skeletal muscle accompanied by non-muscular symptoms. Aberrant glycosylation of α-dystroglycan causes at least eighteen subtypes of MD, now categorized as MD-dystroglycanopathy (MD-DG), with a wide spectrum of non-muscular symptoms. Despite a growing number of MD-DG subtypes and increasing evidence regarding their molecular pathogeneses, no comprehensive study has investigated sensorineural HL (SNHL) in MD-DG. Here, we found that two mouse models of MD-DG, Largemyd/myd and POMGnT1-KO mice, exhibited congenital, non-progressive, and mild-to-moderate SNHL in auditory brainstem response (ABR) accompanied by extended latency of wave I. Profoundly abnormal myelination was found at the peripheral segment of the cochlear nerve, which is rich in the glycosylated α-dystroglycan–laminin complex and demarcated by “the glial dome.” In addition, patients with Fukuyama congenital MD, a type of MD-DG, also had latent SNHL with extended latency of wave I in ABR. Collectively, these findings indicate that hearing impairment associated with impaired Schwann cell-mediated myelination at the peripheral segment of the cochlear nerve is a notable symptom of MD-DG. Hearing loss (HL) is one of the most common sensory impairments and heterogeneous disorders in humans. Up to 60% of HL cases are caused by genetic factors, and approximately 30% of genetic HL cases are syndromic. Although 400–700 genetic syndromes are associated with sensorineural HL (SNHL), caused due to problems in the nerve pathways from the cochlea to the brain, only about 45 genes are known to be associated with syndromic HL. Muscular dystrophies (MDs) are neuromuscular disorders characterized by progressive degeneration of skeletal muscle accompanied by non-muscular symptoms. MD-dystroglycanopathy (MD-DG), caused by aberrant glycosylation of α-dystroglycan, is an MD subtype with a wide spectrum of non-muscular symptoms. Despite a growing number of MD-DG subtypes (at least 18), no comprehensive study has investigated SNHL in MD-DG. Here, we found that hearing impairment was associated with abnormal myelination of the peripheral segment of the cochlear nerve caused by impaired dystrophin–dystroglycan complex in two mouse models (type 3 and 6) of MD-DG and in patients (type 4) with MD-DG. This is the first comprehensive study investigating SNHL in MD-DG. Our findings may provide new insights into understanding the pathogenic characteristics and mechanisms underlying inherited syndromic hearing impairment.
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15
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Abstract
Laminins are large cell-adhesive glycoproteins that are required for the formation and function of basement membranes in all animals. Structural studies by electron microscopy in the early 1980s revealed a cross-shaped molecule, which subsequently was shown to consist of three distinct polypeptide chains. Crystallographic studies since the mid-1990s have added atomic detail to all parts of the laminin heterotrimer. The three short arms of the cross are made up of continuous arrays of disulphide-rich domains. The globular domains at the tips of the short arms mediate laminin polymerization; the surface regions involved in this process have been identified by structure-based mutagenesis. The long arm of the cross is an α-helical coiled coil of all three chains, terminating in a cell-adhesive globular region. The molecular basis of cell adhesion to laminins has been revealed by recent structures of heterotrimeric integrin-binding fragments and of a laminin fragment bound to the carbohydrate modification of dystroglycan. The structural characterization of the laminin molecule is essentially complete, but we still have to find ways of imaging native laminin polymers at molecular resolution.
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16
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Nakane T, Angata K, Sato T, Kaji H, Narimatsu H. Identification of mammalian glycoproteins with type-I LacdiNAc structures synthesized by the glycosyltransferase B3GALNT2. J Biol Chem 2019; 294:7433-7444. [PMID: 30898876 DOI: 10.1074/jbc.ra118.006892] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/04/2019] [Indexed: 11/06/2022] Open
Abstract
The type-I LacdiNAc (LDN; GalNAcβ1-3GlcNAc) has rarely been observed in mammalian cells except in the O-glycan of α-dystroglycan, in contrast to type-II LDN structures (GalNAcβ1-4GlcNAc) in N- and O-glycans that are present in many mammalian glycoproteins, such as pituitary and hypothalamic hormones. Although a β1,3-N-acetylgalactosaminyltransferase 2 (B3GALNT2; type-I LDN synthase) has been cloned, the function of type-I LDN in mammalian cells is still unclear, as its carrier protein(s) has not been identified. In this study, using HeLa cells, we demonstrate that inhibition of Golgi-resident glycosyltransferase increases the abundance of B3GALNT2-synthesized type-I LDN structures, recognized by Wisteria floribunda agglutinin (WFA). Using isotope-coded glycosylation site-specific tagging (IGOT)-LC/MS analysis of Lec8 Chinese hamster cells lacking galactosylation and of cells transfected with the B3GALNT2 gene, we identified the glycoproteins that carry B3GALNT2-generated type-I LDN in their N-glycans. Our results further revealed that LDN presence on low-density lipoprotein receptor-related protein 1 and nicastrin depends on B3GALNT2, indicating the occurrence of type-I LDN in vivo in mammalian cells. Our analysis also uncovered that most of the identified glycoproteins localize to intracellular organelles, particularly to the endoplasmic reticulum. Whereas B4GALNT3 and B4GALNT4 synthesized LDN on extracellular glycoproteins, B3GALNT2 primarily transferred LDN to intracellular glycoproteins, thereby clearly delineating proteins that carry type-I or type-II LDNs. Taken together, our results indicate the presence of mammalian glycoproteins carrying type-I LDN on N-glycans and suggest that type-I and type-II LDNs have different roles in vivo.
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Affiliation(s)
- Takahiro Nakane
- From the Glycoscience and Glycotechnology Research Group, Biotechnology Research Institute for Drug Discovery, Department of Life Science and Biotechnology, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan and.,Doctoral Program in Clinical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8575, Japan
| | - Kiyohiko Angata
- From the Glycoscience and Glycotechnology Research Group, Biotechnology Research Institute for Drug Discovery, Department of Life Science and Biotechnology, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan and
| | - Takashi Sato
- From the Glycoscience and Glycotechnology Research Group, Biotechnology Research Institute for Drug Discovery, Department of Life Science and Biotechnology, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan and
| | - Hiroyuki Kaji
- From the Glycoscience and Glycotechnology Research Group, Biotechnology Research Institute for Drug Discovery, Department of Life Science and Biotechnology, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan and
| | - Hisashi Narimatsu
- From the Glycoscience and Glycotechnology Research Group, Biotechnology Research Institute for Drug Discovery, Department of Life Science and Biotechnology, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan and .,Doctoral Program in Clinical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8575, Japan
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17
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Kanagawa M. Myo-Glyco disease Biology: Genetic Myopathies Caused by Abnormal Glycan Synthesis and Degradation. J Neuromuscul Dis 2019; 6:175-187. [PMID: 30856120 PMCID: PMC6598100 DOI: 10.3233/jnd-180369] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Glycosylation is a major form of post-translational modification and plays various important roles in organisms by modifying proteins or lipids, which generates functional variability and can increase their stability. Because of the physiological importance of glycosylation, defects in genes encoding proteins involved in glycosylation or glycan degradation are sometimes associated with human diseases. A number of genetic neuromuscular diseases are caused by abnormal glycan modification or degeneration. Heterogeneous and complex modification machinery, and difficulties in structural and functional analysis of glycans have impeded the understanding of how glycosylation contributes to pathology. However, recent rapid advances in glycan and genetic analyses, as well as accumulating genetic and clinical information have greatly contributed to identifying glycan structures and modification enzymes, which has led to breakthroughs in the understanding of the molecular pathogenesis of various diseases and the possible development of therapeutic strategies. For example, studies on the relationship between glycosylation and muscular dystrophy in the last two decades have significantly impacted the fields of glycobiology and neuromyology. In this review, the basis of glycan structure and biosynthesis will be briefly explained, and then molecular pathogenesis and therapeutic concepts related to neuromuscular diseases will be introduced from the point of view of the life cycle of a glycan molecule.
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Affiliation(s)
- Motoi Kanagawa
- Division of Molecular Brain Science, Kobe University Graduate School of Medicine, Japan
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18
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Nickolls AR, Bönnemann CG. The roles of dystroglycan in the nervous system: insights from animal models of muscular dystrophy. Dis Model Mech 2018; 11:11/12/dmm035931. [PMID: 30578246 PMCID: PMC6307911 DOI: 10.1242/dmm.035931] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Dystroglycan is a cell membrane protein that binds to the extracellular matrix in a variety of mammalian tissues. The α-subunit of dystroglycan (αDG) is heavily glycosylated, including a special O-mannosyl glycoepitope, relying upon this unique glycosylation to bind its matrix ligands. A distinct group of muscular dystrophies results from specific hypoglycosylation of αDG, and they are frequently associated with central nervous system involvement, ranging from profound brain malformation to intellectual disability without evident morphological defects. There is an expanding literature addressing the function of αDG in the nervous system, with recent reports demonstrating important roles in brain development and in the maintenance of neuronal synapses. Much of these data are derived from an increasingly rich array of experimental animal models. This Review aims to synthesize the information from such diverse models, formulating an up-to-date understanding about the various functions of αDG in neurons and glia of the central and peripheral nervous systems. Where possible, we integrate these data with our knowledge of the human disorders to promote translation from basic mechanistic findings to clinical therapies that take the neural phenotypes into account. Summary: Dystroglycan is a ubiquitous matrix receptor linked to brain and muscle disease. Unraveling the functions of this protein will inform basic and translational research on neural development and muscular dystrophies.
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Affiliation(s)
- Alec R Nickolls
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.,Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Carsten G Bönnemann
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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19
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Hohenester E. Laminin G-like domains: dystroglycan-specific lectins. Curr Opin Struct Biol 2018; 56:56-63. [PMID: 30530204 DOI: 10.1016/j.sbi.2018.11.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 11/23/2018] [Accepted: 11/23/2018] [Indexed: 01/31/2023]
Abstract
A unique O-mannose-linked glycan on the transmembrane protein dystroglycan binds a number of extracellular matrix proteins containing laminin G-like (LG) domains. The dystroglycan-matrix interaction is essential for muscle function: disrupted biosynthesis of the matrix-binding modification causes several forms of muscular dystrophy. The complete chemical structure of this modification has been deciphered in the past few years. We now know that LG domains bind to a glycosaminoglycan-like polysaccharide of [-3GlcAβ1,3Xylα1-] units, termed matriglycan, that is attached to a highly unusual heptasaccharide linker. X-ray crystallography has revealed the principles of Ca2+-dependent matriglycan binding by LG domains. In this review, the new structural insights are applied to the growing number of LG domain-containing proteins that bind dystroglycan. It is proposed that LG domains be recognised as 'D-type' lectins to indicate their conserved function in dystroglycan binding.
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Affiliation(s)
- Erhard Hohenester
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom.
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20
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Quijano-Roy S, de la Banda MGG. Distrofias musculares congénitas. REVISTA MÉDICA CLÍNICA LAS CONDES 2018. [DOI: 10.1016/j.rmclc.2018.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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21
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Detection of variants in dystroglycanopathy-associated genes through the application of targeted whole-exome sequencing analysis to a large cohort of patients with unexplained limb-girdle muscle weakness. Skelet Muscle 2018; 8:23. [PMID: 30060766 PMCID: PMC6066920 DOI: 10.1186/s13395-018-0170-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/13/2018] [Indexed: 12/16/2022] Open
Abstract
Background Dystroglycanopathies are a clinically and genetically heterogeneous group of disorders that are typically characterised by limb-girdle muscle weakness. Mutations in 18 different genes have been associated with dystroglycanopathies, the encoded proteins of which typically modulate the binding of α-dystroglycan to extracellular matrix ligands by altering its glycosylation. This results in a disruption of the structural integrity of the myocyte, ultimately leading to muscle degeneration. Methods Deep phenotypic information was gathered using the PhenoTips online software for 1001 patients with unexplained limb-girdle muscle weakness from 43 different centres across 21 European and Middle Eastern countries. Whole-exome sequencing with at least 250 ng DNA was completed using an Illumina exome capture and a 38 Mb baited target. Genes known to be associated with dystroglycanopathies were analysed for disease-causing variants. Results Suspected pathogenic variants were detected in DPM3, ISPD, POMT1 and FKTN in one patient each, in POMK in two patients, in GMPPB in three patients, in FKRP in eight patients and in POMT2 in ten patients. This indicated a frequency of 2.7% for the disease group within the cohort of 1001 patients with unexplained limb-girdle muscle weakness. The phenotypes of the 27 patients were highly variable, yet with a fundamental presentation of proximal muscle weakness and elevated serum creatine kinase. Conclusions Overall, we have identified 27 patients with suspected pathogenic variants in dystroglycanopathy-associated genes. We present evidence for the genetic and phenotypic diversity of the dystroglycanopathies as a disease group, while also highlighting the advantage of incorporating next-generation sequencing into the diagnostic pathway of rare diseases. Electronic supplementary material The online version of this article (10.1186/s13395-018-0170-1) contains supplementary material, which is available to authorized users.
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Cell endogenous activities of fukutin and FKRP coexist with the ribitol xylosyltransferase, TMEM5. Biochem Biophys Res Commun 2018; 497:1025-1030. [PMID: 29477842 DOI: 10.1016/j.bbrc.2018.02.162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 02/19/2018] [Indexed: 01/28/2023]
Abstract
Dystroglycanopathies are a group of muscular dystrophies that are caused by abnormal glycosylation of dystroglycan; currently 18 causative genes are known. Functions of the dystroglycanopathy genes fukutin, fukutin-related protein (FKRP), and transmembrane protein 5 (TMEM5) were most recently identified; fukutin and FKRP are ribitol-phosphate transferases and TMEM5 is a ribitol xylosyltransferase. In this study, we show that fukutin, FKRP, and TMEM5 form a complex while maintaining each of their enzyme activities. Immunoprecipitation and immunofluorescence experiments demonstrated protein interactions between these 3 proteins. A protein complex consisting of endogenous fukutin and FKRP, and exogenously expressed TMEM5 exerts activities of each enzyme. Our data showed for the first time that endogenous fukutin and FKRP enzyme activities coexist with TMEM5 enzyme activity, and suggest the possibility that formation of this enzyme complex may contribute to specific and prompt biosynthesis of glycans that are required for dystroglycan function.
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Ng BG, Freeze HH. Perspectives on Glycosylation and Its Congenital Disorders. Trends Genet 2018; 34:466-476. [PMID: 29606283 DOI: 10.1016/j.tig.2018.03.002] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/04/2018] [Accepted: 03/05/2018] [Indexed: 12/12/2022]
Abstract
Congenital disorders of glycosylation (CDG) are a rapidly expanding group of metabolic disorders that result from abnormal protein or lipid glycosylation. They are often difficult to clinically diagnose because they broadly affect many organs and functions and lack clinical uniformity. However, recent technological advances in next-generation sequencing have revealed a treasure trove of new genetic disorders, expanded the knowledge of known disorders, and showed a critical role in infectious diseases. More comprehensive genetic tools specifically tailored for mammalian cell-based models have revealed a critical role for glycosylation in pathogen-host interactions, while also identifying new CDG susceptibility genes. We highlight recent advancements that have resulted in a better understanding of human glycosylation disorders, perspectives for potential future therapies, and mysteries for which we continue to seek new insights and solutions.
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Affiliation(s)
- Bobby G Ng
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Hudson H Freeze
- Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
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