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De Geer K, Mascianica K, Naess K, Sardh E, Lindstrand A, Björck E. Unraveling mucolipidosis type III gamma through whole genome sequencing in late-onset retinitis pigmentosa: a case report. BMC Ophthalmol 2023; 23:394. [PMID: 37752499 PMCID: PMC10523780 DOI: 10.1186/s12886-023-03136-4] [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: 01/24/2023] [Accepted: 09/12/2023] [Indexed: 09/28/2023] Open
Abstract
BACKGROUND We describe the case of a 47-year-old man referred to a retinal clinic and diagnosed with late-onset retinitis pigmentosa. Surprisingly, genetic testing revealed compound heterozygous pathogenic variants in GNPTG, leading to the diagnosis of the autosomal recessive lysosomal storage disorder mucolipidosis type III gamma. Mucolipidosis type III gamma is typically diagnosed during childhood due to symptoms relating to skeletal dysplasia. Retinal dystrophy is not a common phenotypic feature. CASE PRESENTATION Ophthalmologic examination was consistent with a mild form of retinitis pigmentosa and included fundus photography, measurement of best-corrected visual acuity, optical coherence tomography, electroretinogram and visual field testing. Extraocular findings included joint restriction and pains from an early age leading to bilateral hip replacement by age 30, aortic insufficiency, and hypertension. Genetic analysis was performed by whole genome sequencing filtered for a gene panel of 325 genes associated with retinal disease. Two compound heterozygous pathogenic variants were identified in GNPTG, c.347_349del and c.607dup. The diagnosis of mucolipidosis type III gamma was confirmed biochemically by measurement of increased activities of specific lysosomal enzymes in plasma. CONCLUSION To our knowledge this is the first description of retinitis pigmentosa caused by compound heterozygous variants in GNPTG, providing further indications that late-onset retinal dystrophy is part of the phenotypic spectrum of mucolipidosis type III gamma.
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Affiliation(s)
- Karl De Geer
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 17177, Stockholm, Sweden.
- Department of Clinical Genetics, Karolinska University Hospital, 17177, Stockholm, Sweden.
| | | | - Karin Naess
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, 17176, Stockholm, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Eliane Sardh
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 17177, Stockholm, Sweden
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, 17176, Stockholm, Sweden
| | - Anna Lindstrand
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 17177, Stockholm, Sweden
- Department of Clinical Genetics, Karolinska University Hospital, 17177, Stockholm, Sweden
| | - Erik Björck
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 17177, Stockholm, Sweden
- Department of Clinical Genetics, Karolinska University Hospital, 17177, Stockholm, Sweden
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2
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Zanetti A, D'Avanzo F, Bertoldi L, Zampieri G, Feltrin E, De Pascale F, Rampazzo A, Forzan M, Valle G, Tomanin R. Setup and Validation of a Targeted Next-Generation Sequencing Approach for the Diagnosis of Lysosomal Storage Disorders. J Mol Diagn 2020; 22:488-502. [PMID: 32036093 DOI: 10.1016/j.jmoldx.2020.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 11/07/2019] [Accepted: 01/11/2020] [Indexed: 12/14/2022] Open
Abstract
Lysosomal storage disorders (LSDs) are monogenic diseases, due to accumulation of specific undegraded substrates into lysosomes. LSD diagnosis could take several years because of both poor knowledge of these diseases and shared clinical features. The diagnostic approach includes clinical evaluations, biochemical tests, and genetic analysis of the suspected gene. In this study, we evaluated an LSD targeted sequencing panel as a tool capable to potentially reverse this classic diagnostic route. The panel includes 50 LSD genes and 230 intronic sequences conserved among 33 placental mammals. For the validation phase, 56 positive controls, 13 biochemically diagnosed patients, and nine undiagnosed patients were analyzed. Disease-causing variants were identified in 66% of the positive control alleles and in 62% of the biochemically diagnosed patients. Three undiagnosed patients were diagnosed. Eight patients undiagnosed by the panel were analyzed by whole exome sequencing: for two of them, the disease-causing variants were identified. Five patients, undiagnosed by both panel and exome analyses, were investigated through array comparative genomic hybridization: one of them was diagnosed. Conserved intronic fragment analysis, performed in cases unresolved by the first-level analysis, evidenced no candidate intronic variants. Targeted sequencing has low sequencing costs and short sequencing time. However, a coverage >60× to 80× must be ensured and/or Sanger validation should be performed. Moreover, it must be supported by a thorough clinical phenotyping.
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Affiliation(s)
- Alessandra Zanetti
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova, Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Francesca D'Avanzo
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova, Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy
| | - Loris Bertoldi
- Department of Biology and CRIBI Biotechnology Centre, University of Padova, Padova, Italy
| | - Guido Zampieri
- Department of Biology and CRIBI Biotechnology Centre, University of Padova, Padova, Italy
| | - Erika Feltrin
- Department of Biology and CRIBI Biotechnology Centre, University of Padova, Padova, Italy
| | - Fabio De Pascale
- Department of Biology and CRIBI Biotechnology Centre, University of Padova, Padova, Italy
| | - Angelica Rampazzo
- Infantile Neuropsychiatric Unit, Department of Women's and Children's Health, University of Padova, Padova, Italy
| | - Monica Forzan
- Clinical Genetics Unit, University Hospital of Padua, Padua, Italy
| | - Giorgio Valle
- Department of Biology and CRIBI Biotechnology Centre, University of Padova, Padova, Italy
| | - Rosella Tomanin
- Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova, Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Padova, Italy.
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3
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Velho RV, Harms FL, Danyukova T, Ludwig NF, Friez MJ, Cathey SS, Filocamo M, Tappino B, Güneş N, Tüysüz B, Tylee KL, Brammeier KL, Heptinstall L, Oussoren E, van der Ploeg AT, Petersen C, Alves S, Saavedra GD, Schwartz IV, Muschol N, Kutsche K, Pohl S. The lysosomal storage disorders mucolipidosis type II, type III alpha/beta, and type III gamma: Update on GNPTAB and GNPTG mutations. Hum Mutat 2019; 40:842-864. [PMID: 30882951 DOI: 10.1002/humu.23748] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/19/2019] [Accepted: 03/14/2019] [Indexed: 01/04/2023]
Abstract
Mutations in the GNPTAB and GNPTG genes cause mucolipidosis (ML) type II, type III alpha/beta, and type III gamma, which are autosomal recessively inherited lysosomal storage disorders. GNPTAB and GNPTG encode the α/β-precursor and the γ-subunit of N-acetylglucosamine (GlcNAc)-1-phosphotransferase, respectively, the key enzyme for the generation of mannose 6-phosphate targeting signals on lysosomal enzymes. Defective GlcNAc-1-phosphotransferase results in missorting of lysosomal enzymes and accumulation of non-degradable macromolecules in lysosomes, strongly impairing cellular function. MLII-affected patients have coarse facial features, cessation of statural growth and neuromotor development, severe skeletal abnormalities, organomegaly, and cardiorespiratory insufficiency leading to death in early childhood. MLIII alpha/beta and MLIII gamma are attenuated forms of the disease. Since the identification of the GNPTAB and GNPTG genes, 564 individuals affected by MLII or MLIII have been described in the literature. In this report, we provide an overview on 258 and 50 mutations in GNPTAB and GNPTG, respectively, including 58 novel GNPTAB and seven novel GNPTG variants. Comprehensive functional studies of GNPTAB missense mutations did not only gain insights into the composition and function of the GlcNAc-1-phosphotransferase, but also helped to define genotype-phenotype correlations to predict the clinical outcome in patients.
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Affiliation(s)
- Renata Voltolini Velho
- Section Cell Biology of Rare Diseases, Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Frederike L Harms
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tatyana Danyukova
- Section Cell Biology of Rare Diseases, Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nataniel F Ludwig
- Department of Genetics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Post-Graduation Program in Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | | | | | - Mirella Filocamo
- Laboratorio di Genetica Molecolare e Biobanche, Istituto Giannina Gaslini, Genova, Italy
| | - Barbara Tappino
- Laboratorio di Genetica Molecolare e Biobanche, Istituto Giannina Gaslini, Genova, Italy
| | - Nilay Güneş
- Department of Pediatric Genetics, Istanbul University Cerrahpasa, Medicine School, Istanbul, Turkey
| | - Beyhan Tüysüz
- Department of Pediatric Genetics, Istanbul University Cerrahpasa, Medicine School, Istanbul, Turkey
| | - Karen L Tylee
- Willink Biochemical Genetics Unit, Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, Saint Mary's Hospital, Manchester, UK
| | - Kathryn L Brammeier
- Willink Biochemical Genetics Unit, Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, Saint Mary's Hospital, Manchester, UK
| | - Lesley Heptinstall
- Genomic Diagnostics Laboratory, Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, Saint Mary's Hospital, Manchester, UK
| | - Esmee Oussoren
- Department of Pediatrics, Center for LyMannose phosphorylation in health and diseasesosomal and Metabolic Diseases, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Ans T van der Ploeg
- Department of Pediatrics, Center for LyMannose phosphorylation in health and diseasesosomal and Metabolic Diseases, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Christine Petersen
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sandra Alves
- Department of Human Genetics, INSA, National Health Institute Doutor Ricardo Jorge, Porto, Portugal
| | - Gloria Durán Saavedra
- División de Pediatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ida V Schwartz
- Department of Genetics, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.,Post-Graduation Program in Genetics and Molecular Biology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Nicole Muschol
- International Center for Lysosomal Disorders, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sandra Pohl
- Section Cell Biology of Rare Diseases, Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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4
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Does the clinical phenotype of mucolipidosis-IIIγ differ from its αβ counterpart?: supporting facts in a cohort of 18 patients. Clin Dysmorphol 2019; 28:7-16. [PMID: 30507725 DOI: 10.1097/mcd.0000000000000249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mucolipidosis-IIIγ (ML-IIIγ) is a recessively inherited slowly progressive skeletal dysplasia caused by mutations in GNPTG. We report the genetic and clinical findings in the largest cohort with ML-IIIγ so far: 18 affected individuals from 12 families including 12 patients from India, five from Turkey, and one from the USA. With consanguinity confirmed in eight of 12 families, molecular characterization showed that all affected patients had homozygous pathogenic GNPTG genotypes, underscoring the rarity of the disorder. Unlike ML-IIIαβ, which present with a broader spectrum of severity, the ML-III γ phenotype is milder, with onset in early school age, but nonetheless thus far considered phenotypically not differentiable from ML-IIIαβ. Evaluation of this cohort has yielded phenotypic findings including hypertrophy of the forearms and restricted supination as clues for ML-IIIγ, facilitating an earlier correct choice of genotype screening. Early identification of this disorder may help in offering a timely intervention for the relief of carpal tunnel syndrome, monitoring and surgery for cardiac valve involvement, and evaluation of the need for joint replacement. As this condition may be confused with rheumatoid arthritis, confirmation of diagnosis will prevent inappropriate use of immunosuppressants and disease-modifying agents.
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5
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Wang Y, Ye J, Qiu WJ, Han LS, Gao XL, Liang LL, Gu XF, Zhang HW. Identification of predominant GNPTAB gene mutations in Eastern Chinese patients with mucolipidosis II/III and a prenatal diagnosis of mucolipidosis II. Acta Pharmacol Sin 2019; 40:279-287. [PMID: 29872134 DOI: 10.1038/s41401-018-0023-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/28/2018] [Indexed: 11/09/2022] Open
Abstract
Mucolipidosis II α/β, mucolipidosis III α/β, and mucolipidosis III γ are autosomal recessive disorders belonging to the family of lysosomal storage disorders caused by deficiency of the UDP-N-acetylglucosamine, a lysosomal enzyme N-acetylglucosamine-1-phosphotransferase (GlcNAc-phosphotransferase) localized in the Golgi apparatus, which is essential for normal processing and packaging of soluble lysosomal enzymes with initiating the first step of tagging lysosomal enzymes with mannose-6-phosphate (M6P). Mucolipidosis II and III are caused by mutations in the GNPTAB and GNPTG genes, and patients with these diseases are characterized by short stature, skeletal abnormalities, and developmental delay. In this study we report 38 patients with mucolipidosis II and III enrolled in Eastern China during the past 8 years. The diagnosis was made based on clinical characteristics and measurement of plasma lysosomal enzyme activity. Sanger sequencing of GNPTAB and/or GNPTG for all patients and real-time quantitative PCR were performed to confirm the diagnosis. In addition, 11 cases of prenatal mucolipidosis II were diagnosed based on measurement of the enzyme activity in amniotic fluid supernatant and genetic testing of cultured amniotic cells. Based on molecular genetic tests, 30 patients were diagnosed with mucolipidosis II α/β, 6 were diagnosed with III α/β and 2 were diagnosed with III γ. Thirty-seven different GNPTAB gene mutations were identified in 29 patients with mucolipidosis II α/β and six patients with III α/β. These mutations included 22 new mutations (p.W44X, p.E279X, p.W416X, p.W463X, p.Q802X, p.Q882X, p.A34P, p.R334P, p.D408N, p.D534N, p.Y997C, p.D1018V, p.L1025S, p.L1033P, c.88_89delAC, c.890_891insT, c.1150_1151insTTA, c.1523delG, c.2473_2474insA, c.2980_2983delGCCT, c.3094delA, and deletion of exon 9). Four new GNPTG gene mutations were identified (c.13delC, p.Y81X, p.G126R and c.609+1delG) in two mucolipidosis III γ patients. Among the 11 cases of prenatal diagnosis, four were mucolipidosis II fetuses, three were heterozygous, and the remaining four were normal fetuses. This study expands the mutation spectrum of the GNPTAB and GNPTG genes and contributes to specific knowledge of mucolipidosis II/III in a population from Eastern China.
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6
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Oussoren E, van Eerd D, Murphy E, Lachmann R, van der Meijden JC, Hoefsloot LH, Verdijk R, Ruijter GJG, Maas M, Hollak CEM, Langendonk JG, van der Ploeg AT, Langeveld M. Mucolipidosis type III, a series of adult patients. J Inherit Metab Dis 2018; 41:839-848. [PMID: 29704188 PMCID: PMC6133174 DOI: 10.1007/s10545-018-0186-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/04/2018] [Accepted: 04/10/2018] [Indexed: 01/29/2023]
Abstract
BACKGROUND Mucolipidosis type III α/β or γ (MLIII) are rare autosomal recessive diseases, in which reduced activity of the enzyme UDP-N-acetyl glucosamine-1-phosphotransferase (GlcNAc-PTase) leads to intra-lysosomal accumulation of different substrates. Publications on the natural history of MLIII, especially the milder forms, are scarce. This study provides a detailed description of the disease characteristics and its natural course in adult patients with MLIII. METHODS In this retrospective chart study, the clinical, biochemical and molecular findings in adult patients with a confirmed diagnosis of MLIII from three treatment centres were collected. RESULTS Thirteen patients with MLIII were included in this study. Four patients (31%) were initially misdiagnosed with a type of mucopolysaccharidosis (MPS). Four patients (31%) had mild cognitive impairment. Six patients (46%) needed help with activities of daily living (ADL) or were wheelchair-dependent. All patients had dysostosis multiplex and progressive secondary osteoarthritis, characterised by cartilage destruction and bone lesions in multiple joints. All patients underwent multiple orthopaedic surgical interventions as early as the second or third decades of life, of which total hip replacement (THR) was the most common procedure (61% of patients). Carpal tunnel syndrome (CTS) was found in 12 patients (92%) and in eight patients (61%), CTS release was performed. CONCLUSIONS Severe skeletal abnormalities, resulting from abnormal bone development and severe progressive osteoarthritis, are the hallmark of MLIII, necessitating surgical orthopaedic interventions early in life. Future therapies for this disease should focus on improving cartilage and bone quality, preventing skeletal complications and improving mobility.
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Affiliation(s)
- Esmee Oussoren
- Department of Pediatrics, Center for Lysosomal and Metabolic Diseases, Erasmus MC—Sophia Children’s Hospital, P.O. Box 2060, 3000 CB Rotterdam, The Netherlands
| | - David van Eerd
- Department of Internal Medicine, Center for Lysosomal and Metabolic Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - Elaine Murphy
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Robin Lachmann
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Jan C. van der Meijden
- Department of Pediatrics, Center for Lysosomal and Metabolic Diseases, Erasmus MC—Sophia Children’s Hospital, P.O. Box 2060, 3000 CB Rotterdam, The Netherlands
| | - Lies H. Hoefsloot
- Department of Clinical Genetics, Center for Lysosomal and Metabolic Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - Rob Verdijk
- Department of Pathology, Erasmus MC, Rotterdam, The Netherlands
| | - George J. G. Ruijter
- Department of Clinical Genetics, Center for Lysosomal and Metabolic Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - Mario Maas
- Department of Radiology and Nuclear Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Carla E. M. Hollak
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Janneke G. Langendonk
- Department of Internal Medicine, Center for Lysosomal and Metabolic Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - Ans T. van der Ploeg
- Department of Pediatrics, Center for Lysosomal and Metabolic Diseases, Erasmus MC—Sophia Children’s Hospital, P.O. Box 2060, 3000 CB Rotterdam, The Netherlands
| | - Mirjam Langeveld
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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7
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Di Lorenzo G, Velho RV, Winter D, Thelen M, Ahmadi S, Schweizer M, De Pace R, Cornils K, Yorgan TA, Grüb S, Hermans-Borgmeyer I, Schinke T, Müller-Loennies S, Braulke T, Pohl S. Lysosomal Proteome and Secretome Analysis Identifies Missorted Enzymes and Their Nondegraded Substrates in Mucolipidosis III Mouse Cells. Mol Cell Proteomics 2018; 17:1612-1626. [PMID: 29773673 DOI: 10.1074/mcp.ra118.000720] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/27/2018] [Indexed: 11/06/2022] Open
Abstract
Targeting of soluble lysosomal enzymes requires mannose 6-phosphate (M6P) signals whose formation is initiated by the hexameric N-acetylglucosamine (GlcNAc)-1-phosphotransferase complex (α2β2γ2). Upon proteolytic cleavage by site-1 protease, the α/β-subunit precursor is catalytically activated but the functions of γ-subunits (Gnptg) in M6P modification of lysosomal enzymes are unknown. To investigate this, we analyzed the Gnptg expression in mouse tissues, primary cultured cells, and in Gnptg reporter mice in vivo, and found high amounts in the brain, eye, kidney, femur, vertebra and fibroblasts. Consecutively we performed comprehensive quantitative lysosomal proteome and M6P secretome analysis in fibroblasts of wild-type and Gnptgko mice mimicking the lysosomal storage disorder mucolipidosis III. Although the cleavage of the α/β-precursor was not affected by Gnptg deficiency, the GlcNAc-1-phosphotransferase activity was significantly reduced. We purified lysosomes and identified 29 soluble lysosomal proteins by SILAC-based mass spectrometry exhibiting differential abundance in Gnptgko fibroblasts which was confirmed by Western blotting and enzymatic activity analysis for selected proteins. A subset of these lysosomal enzymes show also reduced M6P modifications, fail to reach lysosomes and are secreted, among them α-l-fucosidase and arylsulfatase B. Low levels of these enzymes correlate with the accumulation of non-degraded fucose-containing glycostructures and sulfated glycosaminoglycans in Gnptgko lysosomes. Incubation of Gnptgko fibroblasts with arylsulfatase B partially rescued glycosaminoglycan storage. Combinatorial treatments with other here identified missorted enzymes of this degradation pathway might further correct glycosaminoglycan accumulation and will provide a useful basis to reveal mechanisms of selective, Gnptg-dependent formation of M6P residues on lysosomal proteins.
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Affiliation(s)
- Giorgia Di Lorenzo
- From the ‡Section Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Renata Voltolini Velho
- From the ‡Section Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dominic Winter
- §Institute of Biochemistry and Molecular Biology, University of Bonn, Bonn, Germany
| | - Melanie Thelen
- §Institute of Biochemistry and Molecular Biology, University of Bonn, Bonn, Germany
| | - Shiva Ahmadi
- §Institute of Biochemistry and Molecular Biology, University of Bonn, Bonn, Germany
| | - Michaela Schweizer
- ¶Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Raffaella De Pace
- From the ‡Section Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kerstin Cornils
- ‖Research Department Cell and Gene Therapy, Department of Stem Cell Transplantation, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Timur Alexander Yorgan
- **Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Saskia Grüb
- From the ‡Section Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Irm Hermans-Borgmeyer
- ¶Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thorsten Schinke
- **Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Sven Müller-Loennies
- ‡‡Division Biophysics, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Thomas Braulke
- From the ‡Section Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany;
| | - Sandra Pohl
- From the ‡Section Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany;
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8
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Popa-Wagner A, Glavan DG, Olaru A, Olaru DG, Margaritescu O, Tica O, Surugiu R, Sandu RE. Present Status and Future Challenges of New Therapeutic Targets in Preclinical Models of Stroke in Aged Animals with/without Comorbidities. Int J Mol Sci 2018; 19:ijms19020356. [PMID: 29370078 PMCID: PMC5855578 DOI: 10.3390/ijms19020356] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 01/18/2018] [Accepted: 01/22/2018] [Indexed: 01/02/2023] Open
Abstract
The aging process, comorbidities, and age-associated diseases are closely dependent on each other. Cerebral ischemia impacts a wide range of systems in an age-dependent manner. However, the aging process has many facets which are influenced by the genetic background and epigenetic or environmental factors, which can explain why some people age differently than others. Therefore, there is an urgent need to identify age-related changes in body functions or structures that increase the risk for stroke and which are associated with a poor outcome. Multimodal imaging, electrophysiology, cell biology, proteomics, and transcriptomics, offer a useful approach to link structural and functional changes in the aging brain, with or without comorbidities, to post-stroke rehabilitation. This can help us to improve our knowledge about senescence firstly, and in this context, aids in elucidating the pathophysiology of age-related diseases that allows us to develop therapeutic strategies or prevent diseases. These processes, including potential therapeutical interventions, need to be studied first in relevant preclinical models using aged animals, with and without comorbidities. Therefore, preclinical research on ischemic stroke should consider age as the most important risk factor for cerebral ischemia. Furthermore, the identification of effective therapeutic strategies, corroborated with successful translational studies, will have a dramatic impact on the lives of millions of people with cerebrovascular diseases.
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Affiliation(s)
- Aurel Popa-Wagner
- Griffith University School of Medicine, Gold Coast Campus, QLD, Queensland Eye Institute, Brisbane, QLD 4101, Australia.
- Department of Functional Sciences, Center of Clinical and Experimental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania.
| | - Daniela-Gabriela Glavan
- Psychiatry Clinic Hospital, University of Medicine and Pharmacy of Craiova, Petru Rares Street 2, 200349 Craiova, Romania.
| | - Andrei Olaru
- Department of Ophthalmology, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania.
| | | | - Otilia Margaritescu
- Department of Neurosurgery, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania.
| | - Oana Tica
- Department of "Mother and Child", University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania.
| | - Roxana Surugiu
- Department of Functional Sciences, Center of Clinical and Experimental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania.
| | - Raluca Elena Sandu
- Department of Functional Sciences, Center of Clinical and Experimental Medicine, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania.
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9
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Tüysüz B, Kasapçopur Ö, Alkaya DU, Şahin S, Sözeri B, Yeşil G. Mucolipidosis type III gamma: Three novel mutation and genotype-phenotype study in eleven patients. Gene 2017; 642:398-407. [PMID: 29170090 DOI: 10.1016/j.gene.2017.11.052] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 11/07/2017] [Accepted: 11/17/2017] [Indexed: 11/18/2022]
Abstract
Mucolipidosis type III gamma (MLIII gamma) is a lysosomal storage disease characterized by joint stiffness, mild coarse face and corneal clouding, which becomes recognizable usually in childhood. Biallelic mutations in the GNPTG gene, which encode the γ subunit of the N-acetylglucosamine-1-phosphotransferase enzyme, are the underlying cause of MLIII gamma. The aim of this study is to evaluate the longitudinal findings and genotype of eleven patients from eight families with MLIII gamma and to establish a genotype-phenotype correlation. The most frequently observed initial finding was stiffness of finger joints, which detected in patients between 18month-olds and five year-olds. However, in four patients presented here, initial finding was knee pain or waddling gait, which started between six-16years of age. All patients also had variable degrees of stiffness on large joints. The longest follow up period was 16years while the shortest was three years and six months. We observed that the patients who had an early onset disease and severe joint stiffness had also rapidly progressive joint involvement mostly localized in hands, shoulders, and hip. However; the patients with late onset and/or mild joint stiffness experienced slowly progressive symptoms. Most patients dropped in their growth curve in time and the ones who were severely affected reached the final height below the third centile. Seven disease-causing mutations, three of them novel, were detected in GNPTG gene. According to our clinical observations c.493_494insC and c.283_284insC mutations lead to a severe phenotype and c.196C>T, c.347_349del, c.652_655delTACT and c.445delG/c.367A>G mutations seemed to generate a milder phenotype.
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Affiliation(s)
- Beyhan Tüysüz
- Department of Pediatric Genetics, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey.
| | - Özgür Kasapçopur
- Department of Pediatric Rheumatology, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey
| | - Dilek Uludağ Alkaya
- Department of Pediatric Genetics, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey
| | - Sezgin Şahin
- Department of Pediatric Rheumatology, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey
| | - Betül Sözeri
- Department of Pediatric Rheumatology, Ege University Medical School, Izmir, Turkey
| | - Gözde Yeşil
- Department of Medical Genetics, BezmialemVakif University, Istanbul, Turkey
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10
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Flanagan-Steet H, Matheny C, Petrey A, Parker J, Steet R. Enzyme-specific differences in mannose phosphorylation between GlcNAc-1-phosphotransferase αβ and γ subunit deficient zebrafish support cathepsin proteases as early mediators of mucolipidosis pathology. Biochim Biophys Acta Gen Subj 2016; 1860:1845-53. [PMID: 27241848 DOI: 10.1016/j.bbagen.2016.05.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/28/2016] [Accepted: 05/20/2016] [Indexed: 11/25/2022]
Abstract
Targeting soluble acid hydrolases to lysosomes requires the addition of mannose 6-phosphate residues on their N-glycans. This process is initiated by GlcNAc-1-phosphotransferase, a multi-subunit enzyme encoded by the GNPTAB and GNPTG genes. The GNPTAB gene products (the α and ß subunits) are responsible for recognition and catalysis of hydrolases whereas the GNPTG gene product (the γ subunit) enhances mannose phosphorylation of a subset of hydrolases. Here we identify and characterize a zebrafish gnptg insertional mutant and show that loss of the gamma subunit reduces mannose phosphorylation on a subset glycosidases but does not affect modification of several cathepsin proteases. We further show that glycosidases, but not cathepsins, are hypersecreted from gnptg(-/-) embryonic cells, as evidenced by reduced intracellular activity and increased circulating serum activity. The gnptg(-/-) embryos lack the gross morphological or craniofacial phenotypes shown in gnptab-deficient morphant embryos to result from altered cathepsin activity. Despite the lack of overt phenotypes, decreased fertilization and embryo survival were noted in mutants, suggesting that gnptg associated deposition of mannose 6-phosphate modified hydrolases into oocytes is important for early embryonic development. Collectively, these findings demonstrate that loss of the zebrafish GlcNAc-1-phosphotransferase γ subunit causes enzyme-specific effects on mannose phosphorylation. The finding that cathepsins are normally modified in gnptg(-/-) embryos is consistent with data from gnptab-deficient zebrafish suggesting these proteases are the key mediators of acute pathogenesis. This work also establishes a valuable new model that can be used to probe the functional relevance of GNPTG mutations in the context of a whole animal.
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Affiliation(s)
- Heather Flanagan-Steet
- Complex Carbohydrate Research Center, 315 Riverbend Road, University of Georgia, Athens, GA 30602, United States
| | - Courtney Matheny
- Complex Carbohydrate Research Center, 315 Riverbend Road, University of Georgia, Athens, GA 30602, United States
| | - Aaron Petrey
- Complex Carbohydrate Research Center, 315 Riverbend Road, University of Georgia, Athens, GA 30602, United States
| | - Joshua Parker
- Complex Carbohydrate Research Center, 315 Riverbend Road, University of Georgia, Athens, GA 30602, United States
| | - Richard Steet
- Complex Carbohydrate Research Center, 315 Riverbend Road, University of Georgia, Athens, GA 30602, United States.
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11
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van Meel E, Kornfeld S. Mucolipidosis III GNPTG Missense Mutations Cause Misfolding of the γ Subunit of GlcNAc-1-Phosphotransferase. Hum Mutat 2016; 37:623-6. [PMID: 27038293 DOI: 10.1002/humu.22993] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 03/08/2016] [Indexed: 11/08/2022]
Abstract
The lysosomal storage disorder ML III γ is caused by defects in the γ subunit of UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase, the enzyme that tags lysosomal enzymes with the mannose 6-phosphate lysosomal targeting signal. In patients with this disorder, most of the newly synthesized lysosomal enzymes are secreted rather than being sorted to lysosomes, resulting in increased levels of these enzymes in the plasma. Several missense mutations in GNPTG, the gene encoding the γ subunit, have been reported in mucolipidosis III γ patients. However, in most cases, the impact of these mutations on γ subunit function has remained unclear. Here, we report that the variants c.316G>A (p.G106S), c.376G>A (p.G126S), and c.425G>A (p.C142Y) cause misfolding of the γ subunit, whereas another variant, c.857C>T (p.T286M), does not appear to alter γ subunit function. The misfolded γ subunits were retained in the ER and failed to rescue the lysosomal targeting of lysosomal acid glycosidases.
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Affiliation(s)
- Eline van Meel
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
| | - Stuart Kornfeld
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, 63110, USA
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12
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Enigmatic in vivo GlcNAc-1-phosphotransferase (GNPTG) transcript correction to wild type in two mucolipidosis III gamma siblings homozygous for nonsense mutations. J Hum Genet 2016; 61:555-60. [PMID: 26935170 DOI: 10.1038/jhg.2016.13] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 01/20/2016] [Accepted: 01/21/2016] [Indexed: 12/25/2022]
Abstract
Mucolipidosis (ML) III gamma is a rare autosomal-recessive disorder caused by pathogenic mutations in the GNPTG gene. GNPTG encodes the γ-subunit of GlcNAc-1-phosphotransferase that catalyzes mannose 6-phosphate targeting signal synthesis on soluble lysosomal enzymes. ML III gamma patients are characterized by missorting of lysosomal enzymes. In this report, we describe the probable occurrence of mRNA editing in two ML III gamma patients. Patients A and B (siblings) presented at the adult age with a typical clinical picture of ML III gamma, mainly compromising bone and joints, and high levels of lysosomal enzymes in plasma and low levels in fibroblasts. Both were found to be homozygous for c.-112C>G and c.328G>T (p.Glu110Ter) mutations in genomic DNA (gDNA) analysis of GNPTG. Analysis of complementary DNA (cDNA), however, showed normal genotypes for both patients. Low GNPTG mRNA expression was observed in both patients. The mRNA editing can explain the differences found in patients A and B regarding gDNA and cDNA analysis, and the mild clinical phenotype associated with homozygosity for a nonsense mutation. Our results suggest that mRNA editing can be more frequent than expected in monogenic disorders and that GNPTG analysis should be performed on gDNA.
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13
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Velho RV, De Pace R, Klünder S, Sperb-Ludwig F, Lourenço CM, Schwartz IVD, Braulke T, Pohl S. Analyses of disease-related GNPTAB mutations define a novel GlcNAc-1-phosphotransferase interaction domain and an alternative site-1 protease cleavage site. Hum Mol Genet 2015; 24:3497-505. [PMID: 25788519 PMCID: PMC4498157 DOI: 10.1093/hmg/ddv100] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 03/13/2015] [Indexed: 12/22/2022] Open
Abstract
Mucolipidosis II (MLII) and III alpha/beta are autosomal-recessive diseases of childhood caused by mutations in GNPTAB encoding the α/β-subunit precursor protein of the GlcNAc-1-phosphotransferase complex. This enzyme modifies lysosomal hydrolases with mannose 6-phosphate targeting signals. Upon arrival in the Golgi apparatus, the newly synthesized α/β-subunit precursor is catalytically activated by site-1 protease (S1P). Here we performed comprehensive expression studies of GNPTAB mutations, including two novel mutations T644M and T1223del, identified in Brazilian MLII/MLIII alpha/beta patients. We show that the frameshift E757KfsX1 and the non-sense R587X mutations result in the retention of enzymatically inactive truncated precursor proteins in the endoplasmic reticulum (ER) due to loss of cytosolic ER exit motifs consistent with a severe clinical phenotype in homozygosity. The luminal missense mutations, C505Y, G575R and T644M, partially impaired ER exit and proteolytic activation in accordance with less severe MLIII alpha/beta disease symptoms. Analogous to the previously characterized S399F mutant, we found that the missense mutation I403T led to retention in the ER and loss of catalytic activity. Substitution of further conserved residues in stealth domain 2 (I346 and W357) revealed similar biochemical properties and allowed us to define a putative binding site for accessory proteins required for ER exit of α/β-subunit precursors. Interestingly, the analysis of the Y937_M972del mutant revealed partial Golgi localization and formation of abnormal inactive β-subunits generated by S1P which correlate with a clinical MLII phenotype. Expression analyses of mutations identified in patients underline genotype–phenotype correlations in MLII/MLIII alpha/beta and provide novel insights into structural requirements of proper GlcNAc-1-phosphotransferase activity.
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Affiliation(s)
- Renata Voltolini Velho
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Avenida Paulo Gama 110, 90040-060 Porto Alegre, Brazil
| | - Raffaella De Pace
- Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Sarah Klünder
- Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Fernanda Sperb-Ludwig
- Laboratory of Basic Research and Advanced Investigations in Neurosciences, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcellos 2350, 90035-903 Porto Alegre, Brazil and
| | - Charles Marques Lourenço
- Neurogenetics Unit, Department of Neurology, School of Medicine of Ribeirao Preto, University of São Paulo, Avenida Bandeirantes 3900, 14050-260 Ribeirão Preto, Brazil
| | - Ida V D Schwartz
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Avenida Paulo Gama 110, 90040-060 Porto Alegre, Brazil, Laboratory of Basic Research and Advanced Investigations in Neurosciences, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcellos 2350, 90035-903 Porto Alegre, Brazil and
| | - Thomas Braulke
- Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Sandra Pohl
- Department of Biochemistry, Children's Hospital, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany,
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14
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Idol RA, Wozniak DF, Fujiwara H, Yuede CM, Ory DS, Kornfeld S, Vogel P. Neurologic abnormalities in mouse models of the lysosomal storage disorders mucolipidosis II and mucolipidosis III γ. PLoS One 2014; 9:e109768. [PMID: 25314316 PMCID: PMC4196941 DOI: 10.1371/journal.pone.0109768] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/12/2014] [Indexed: 12/02/2022] Open
Abstract
UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase is an α2β2γ2 hexameric enzyme that catalyzes the synthesis of the mannose 6-phosphate targeting signal on lysosomal hydrolases. Mutations in the α/β subunit precursor gene cause the severe lysosomal storage disorder mucolipidosis II (ML II) or the more moderate mucolipidosis III alpha/beta (ML III α/β), while mutations in the γ subunit gene cause the mildest disorder, mucolipidosis III gamma (ML III γ). Here we report neurologic consequences of mouse models of ML II and ML III γ. The ML II mice have a total loss of acid hydrolase phosphorylation, which results in depletion of acid hydrolases in mesenchymal-derived cells. The ML III γ mice retain partial phosphorylation. However, in both cases, total brain extracts have normal or near normal activity of many acid hydrolases reflecting mannose 6-phosphate-independent lysosomal targeting pathways. While behavioral deficits occur in both models, the onset of these changes occurs sooner and the severity is greater in the ML II mice. The ML II mice undergo progressive neurodegeneration with neuronal loss, astrocytosis, microgliosis and Purkinje cell depletion which was evident at 4 months whereas ML III γ mice have only mild to moderate astrocytosis and microgliosis at 12 months. Both models accumulate the ganglioside GM2, but only ML II mice accumulate fucosylated glycans. We conclude that in spite of active mannose 6-phosphate-independent targeting pathways in the brain, there are cell types that require at least partial phosphorylation function to avoid lysosomal dysfunction and the associated neurodegeneration and behavioral impairments.
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Affiliation(s)
- Rachel A Idol
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - David F Wozniak
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Hideji Fujiwara
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Carla M Yuede
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Daniel S Ory
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Stuart Kornfeld
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Peter Vogel
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
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15
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Mäkinen VP, Civelek M, Meng Q, Zhang B, Zhu J, Levian C, Huan T, Segrè AV, Ghosh S, Vivar J, Nikpay M, Stewart AFR, Nelson CP, Willenborg C, Erdmann J, Blakenberg S, O'Donnell CJ, März W, Laaksonen R, Epstein SE, Kathiresan S, Shah SH, Hazen SL, Reilly MP, Lusis AJ, Samani NJ, Schunkert H, Quertermous T, McPherson R, Yang X, Assimes TL. Integrative genomics reveals novel molecular pathways and gene networks for coronary artery disease. PLoS Genet 2014; 10:e1004502. [PMID: 25033284 PMCID: PMC4102418 DOI: 10.1371/journal.pgen.1004502] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 05/27/2014] [Indexed: 12/13/2022] Open
Abstract
The majority of the heritability of coronary artery disease (CAD) remains unexplained, despite recent successes of genome-wide association studies (GWAS) in identifying novel susceptibility loci. Integrating functional genomic data from a variety of sources with a large-scale meta-analysis of CAD GWAS may facilitate the identification of novel biological processes and genes involved in CAD, as well as clarify the causal relationships of established processes. Towards this end, we integrated 14 GWAS from the CARDIoGRAM Consortium and two additional GWAS from the Ottawa Heart Institute (25,491 cases and 66,819 controls) with 1) genetics of gene expression studies of CAD-relevant tissues in humans, 2) metabolic and signaling pathways from public databases, and 3) data-driven, tissue-specific gene networks from a multitude of human and mouse experiments. We not only detected CAD-associated gene networks of lipid metabolism, coagulation, immunity, and additional networks with no clear functional annotation, but also revealed key driver genes for each CAD network based on the topology of the gene regulatory networks. In particular, we found a gene network involved in antigen processing to be strongly associated with CAD. The key driver genes of this network included glyoxalase I (GLO1) and peptidylprolyl isomerase I (PPIL1), which we verified as regulatory by siRNA experiments in human aortic endothelial cells. Our results suggest genetic influences on a diverse set of both known and novel biological processes that contribute to CAD risk. The key driver genes for these networks highlight potential novel targets for further mechanistic studies and therapeutic interventions. Sudden death due to heart attack ranks among the top causes of death in the world, and family studies have shown that genetics has a substantial effect on heart disease risk. Recent studies suggest that multiple genetic factors each with modest effects are necessary for the development of CAD, but the genes and molecular processes involved remain poorly understood. We conducted an integrative genomics study where we used the information of gene-gene interactions to capture groups of genes that are most likely to increase heart disease risk. We not only confirmed the importance of several known CAD risk processes such as the metabolism and transport of cholesterol, immune response, and blood coagulation, but also revealed many novel processes such as neuroprotection, cell cycle, and proteolysis that were not previously implicated in CAD. In particular, we highlight several genes such as GLO1 with key regulatory roles within these processes not detected by the first wave of genetic analyses. These results highlight the value of integrating population genetic data with diverse resources that functionally annotate the human genome. Such integration facilitates the identification of novel molecular processes involved in the pathogenesis of CAD as well as potential novel targets for the development of efficacious therapeutic interventions.
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Affiliation(s)
- Ville-Petteri Mäkinen
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California, United States of America
- South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia
| | - Mete Civelek
- Department of Medicine/Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Qingying Meng
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Jun Zhu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Candace Levian
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Tianxiao Huan
- National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts, United States of America
| | - Ayellet V. Segrè
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts, United States of America
| | - Sujoy Ghosh
- Department of Cardiovascular and Metabolic Research, Biomedical Biotechnology Research Institute, North Carolina Central University, Durham, North Carolina, United States of America
- Program in Cardiovascular and Metabolic Disorders and Centre for Computational Biology, Duke-NUS Graduate Medical School, Singapore
| | - Juan Vivar
- Department of Cardiovascular and Metabolic Research, Biomedical Biotechnology Research Institute, North Carolina Central University, Durham, North Carolina, United States of America
| | - Majid Nikpay
- Atherogenomics Laboratory, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Alexandre F. R. Stewart
- John and Jennifer Ruddy Canadian Cardiovascular Research Center, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Christopher P. Nelson
- Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital, Leicester, United Kingdom
- National Institute for Health Research (NIHR) Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital, Leicester, United Kingdom
| | - Christina Willenborg
- Institut für Integrative und Experimentelle Genomik, University of Lübeck, Lübeck, Germany
| | - Jeanette Erdmann
- Institut für Integrative und Experimentelle Genomik, University of Lübeck, Lübeck, Germany
- DZHK (German Research Centre for Cardiovascular Research), partner site Hamburg, Kiel, Lübeck, Germany
| | - Stefan Blakenberg
- Clinic for General and Interventional Cardiology, University Heart Center Hamburg, Hamburg, Germany
| | - Christopher J. O'Donnell
- National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts, United States of America
- Cardiology Division, Center for Human Genetic Research, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Winfried März
- Mannheim Institute of Public Health, Social and Preventive Medicine, Medical Faculty of Mannheim, University of Heidelberg, Mannheim, Germany
- Synlab Academy, Mannheim, Germany
| | - Reijo Laaksonen
- Science Center, Tampere University Hospital, Tampere, Finland
| | - Stephen E. Epstein
- Cardiovascular Research Institute, Washington Hospital Center, Washington, D.C., United States of America
| | - Sekar Kathiresan
- National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts, United States of America
- Cardiology Division, Center for Human Genetic Research, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Svati H. Shah
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | | | - Muredach P. Reilly
- Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | | | - Aldons J. Lusis
- Department of Medicine/Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Nilesh J. Samani
- Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital, Leicester, United Kingdom
- National Institute for Health Research (NIHR) Leicester Cardiovascular Biomedical Research Unit, Glenfield Hospital, Leicester, United Kingdom
| | - Heribert Schunkert
- DZHK (German Research Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
- Deutsches Herzzentrum München, Technische Universität München, Munich, Germany
| | - Thomas Quertermous
- Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
| | - Ruth McPherson
- Atherogenomics Laboratory, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Xia Yang
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California, United States of America
- * E-mail: (XY); (TLA)
| | - Themistocles L. Assimes
- Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail: (XY); (TLA)
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16
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Velho RV, Alegra T, Sperb F, Ludwig NF, Saraiva-Pereira ML, Matte U, Schwartz IVD. A de novo or germline mutation in a family with Mucolipidosis III gamma: Implications for molecular diagnosis and genetic counseling. Mol Genet Metab Rep 2014; 1:98-102. [PMID: 27896079 PMCID: PMC5121289 DOI: 10.1016/j.ymgmr.2014.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 01/26/2014] [Accepted: 01/26/2014] [Indexed: 11/23/2022] Open
Abstract
Mucolipidosis III (ML III) gamma is a very rare autosomal-recessive disorder characterized by the abnormal trafficking and subcellular localization of lysosomal enzymes due to mutations in the GNPTG gene. The present study consists of a report of a Brazilian compound heterozygote patient with ML III gamma resulting from one mutant paternal allele and one allele that had most likely undergone a de novo or maternal germline mutation. This is the first report of a de novo mutation in ML III gamma. This finding has significant implications for genetic counseling.
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Affiliation(s)
- Renata Voltolini Velho
- Gene Therapy Center, Experimental Research Center, Hospital de Clínicas de Porto Alegre, RS, Brazil; Genetics and Molecular Biology Postgraduate Program, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Taciane Alegra
- Genetics and Molecular Biology Postgraduate Program, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Fernanda Sperb
- Gene Therapy Center, Experimental Research Center, Hospital de Clínicas de Porto Alegre, RS, Brazil; Postgraduation Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Nataniel Floriano Ludwig
- Gene Therapy Center, Experimental Research Center, Hospital de Clínicas de Porto Alegre, RS, Brazil
| | - Maria Luiza Saraiva-Pereira
- Genetics and Molecular Biology Postgraduate Program, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto Alegre, RS, Brazil
| | - Ursula Matte
- Gene Therapy Center, Experimental Research Center, Hospital de Clínicas de Porto Alegre, RS, Brazil; Genetics and Molecular Biology Postgraduate Program, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Ida V D Schwartz
- Genetics and Molecular Biology Postgraduate Program, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Department of Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Postgraduation Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Brain Laboratory, Experimental Research Center, Hospital de Clínicas de Porto Alegre, RS, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto Alegre, RS, Brazil
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17
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Liu S, Zhang W, Shi H, Meng Y, Qiu Z. Three novel homozygous mutations in the GNPTG gene that cause mucolipidosis type III gamma. Gene 2013; 535:294-8. [PMID: 24316125 DOI: 10.1016/j.gene.2013.11.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 10/30/2013] [Accepted: 11/04/2013] [Indexed: 11/27/2022]
Abstract
BACKGROUND Mucolipidosis type III gamma (MLIII gamma) is an autosomal recessive disease caused by a mutation in the GNPTG gene, which encodes the γ subunit of the N-acetylglucosamine-1-phosphotransferase (GlcNAc-1-phosphotransferase). This protein plays a key role in the transport of lysosomal hydrolases to the lysosome. METHODS Three Chinese children with typical skeletal abnormalities of MLIII were identified, who were from unrelated consanguineous families. After obtaining informed consent, genomic DNA was isolated from the patients and their parents. Direct sequencing of the GNPTG and GNPTAB genes was performed using standard PCR reactions. RESULTS The three probands showed clinical features typical of MLIII gamma, such as joint stiffness and vertebral scoliosis without coarsened facial features. Mutation analysis of the GNPTG gene showed that three novel mutations were identified, two in exon seven [c.425G>A (p.Cys142Val)] and [c.515dupC (p.His172Profs27X)], and one in exon eight [c.609+1G>C]. Their parents were determined to be heterozygous carriers when compared to the reference sequence in GenBank on NCBI. CONCLUSIONS Mutation of the GNPTG gene is the cause of MLIII gamma in our patients. Our findings expand the mutation spectrum of the GNPTG gene and extend the knowledge of the phenotype-genotype correlation of the disease.
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Affiliation(s)
- Shuang Liu
- Department of Pediatrics, PUMC Hospital, CAMS&PUMC, Beijing 100730, PR China
| | - Weimin Zhang
- Clinical Research Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, PR China
| | - Huiping Shi
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, PR China
| | - Yan Meng
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, PR China
| | - Zhengqing Qiu
- Department of Pediatrics, PUMC Hospital, CAMS&PUMC, Beijing 100730, PR China.
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Mucolipidosis II and III alpha/beta in Brazil: analysis of the GNPTAB gene. Gene 2013; 524:59-64. [PMID: 23566849 DOI: 10.1016/j.gene.2013.03.105] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 03/03/2013] [Accepted: 03/26/2013] [Indexed: 11/20/2022]
Abstract
UNLABELLED Mucolipidosis II and III (MLII and MLIII) alpha/beta are rare autosomal recessive lysosomal storage diseases (LSDs) caused by pathogenic variations in the GNPTAB gene. GNPTAB gene codes for the α and β subunits of phosphotransferase, the enzyme responsible for synthesis of the mannose-6-phosphate (M6P) marker that directs lysosomal enzymes to the lysosome. OBJECTIVES The objective of this study is to identify sequence variations of the GNPTAB gene in Brazilian patients with MLII and MLIII alpha/beta. METHOD Sequencing of the GNPTAB gene was performed in samples of gDNA extracted from the peripheral blood of patients with MLII/III diagnosed at a national reference center for LSDs. RESULTS Twelve unrelated patients, from several regions of Brazil, were included in this study. Only one was born of consanguineous parents. All patients were found to carry at least one nonpathogenic variation. Nine causal sequence variations were found: c.242G>T (p.W81L); c.1123C>T (p.R375X); c.1196C>T (p.S399F); c.1208T>C (p.I403T); c.1514G>A (p.C505Y); c.1759C>T (p.R587X); c.2808A>G (p.Y937_M972del, novel mutation); c. 2269_2273delGAAAC (p.E757KfsX2, novel mutation); and c.3503_3504delTC (p.L1168QfsX5). Both pathogenic variations were identified in 8 of 12 patients; in four patients, only one pathogenic variation was identified. Mutation c.3503_3504delTC, located in exon 19, was the most frequent pathogenic variation found (n=11/24 alleles). The deleterious effect of the c.2808A>C mutation on splicing was confirmed by cDNA analysis. DISCUSSION/CONCLUSIONS Our findings confirm that the GNPTAB gene presents broad allelic heterogeneity and suggests that, in Brazilian ML II and III patients, screening for mutations should begin at exon 19 of the GNPTAB gene. Further analyses will be conducted on patients in whom both pathogenic mutations have not been found in this study.
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Abstract
Our knowledge about human genes and the consequences of mutations leading to human genetic diseases has drastically improved over the last few years. It has been recognized that many mutations are indeed pathogenic because they impact the mRNA rather than the protein itself. With our better understanding of the very complex mechanism of splicing, various bioinformatics tools have been developed. They are now frequently used not only to search for sequence motifs corresponding to splicing signals (splice sites, branch points, ESE, and ESS) but also to predict the impact of mutations on these signals. We now need to address the impact of mutations that affect the splicing process, as their consequences could vary from the activation of cryptic signals to the skipping of one or multiple exons. Despite the major developments of the bioinformatics field coupled to experimental data generated on splicing, it is today still not possible to efficiently predict the consequences of mutations impacting splicing signals, especially to predict if they will lead to exon skipping or to cryptic splice site activation.
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Voorbij AMWY, van Steenbeek FG, Vos-Loohuis M, Martens EECP, Hanson-Nilsson JM, van Oost BA, Kooistra HS, Leegwater PA. A contracted DNA repeat in LHX3 intron 5 is associated with aberrant splicing and pituitary dwarfism in German shepherd dogs. PLoS One 2011; 6:e27940. [PMID: 22132174 PMCID: PMC3223203 DOI: 10.1371/journal.pone.0027940] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 10/28/2011] [Indexed: 12/03/2022] Open
Abstract
Dwarfism in German shepherd dogs is due to combined pituitary hormone deficiency of unknown genetic cause. We localized the recessively inherited defect by a genome wide approach to a region on chromosome 9 with a lod score of 9.8. The region contains LHX3, which codes for a transcription factor essential for pituitary development. Dwarfs have a deletion of one of six 7 bp repeats in intron 5 of LHX3, reducing the intron size to 68 bp. One dwarf was compound heterozygous for the deletion and an insertion of an asparagine residue in the DNA-binding homeodomain of LHX3, suggesting involvement of the gene in the disorder. An exon trapping assay indicated that the shortened intron is not spliced efficiently, probably because it is too small. We applied bisulfite conversion of cytosine to uracil in RNA followed by RT-PCR to analyze the splicing products. The aberrantly spliced RNA molecules resulted from either skipping of exon 5 or retention of intron 5. The same splicing defects were observed in cDNA derived from the pituitary of dwarfs. A survey of similarly mutated introns suggests that there is a minimal distance requirement between the splice donor and branch site of 50 nucleotides. In conclusion, a contraction of a DNA repeat in intron 5 of canine LHX3 leads to deficient splicing and is associated with pituitary dwarfism.
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Affiliation(s)
- Annemarie M. W. Y. Voorbij
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Frank G. van Steenbeek
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Manon Vos-Loohuis
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Ellen E. C. P. Martens
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Jeanette M. Hanson-Nilsson
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Bernard A. van Oost
- Department of Biochemistry, American University of the Caribbean, Cupecoy, St. Maarten, Netherlands Antilles
| | - Hans S. Kooistra
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Peter A. Leegwater
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- * E-mail:
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Using next-generation sequencing for the diagnosis of rare disorders: a family with retinitis pigmentosa and skeletal abnormalities. J Pathol 2011; 225:12-8. [DOI: 10.1002/path.2941] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Gao Y, Yang K, Xu S, Wang C, Liu J, Zhang Z, Yuan M, Luo X, Liu M, Wang QK, Liu JY. Identification of compound heterozygous mutations in GNPTG in three siblings of a Chinese family with mucolipidosis type III gamma. Mol Genet Metab 2011; 102:107-9. [PMID: 20951619 DOI: 10.1016/j.ymgme.2010.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Accepted: 09/18/2010] [Indexed: 10/19/2022]
Abstract
Mucolipidosis III gamma is an autosomal recessive disorder with defective phosphorylation and trafficking of lysosomal enzymes. In a Chinese family with three siblings, linkage analysis revealed positive linkage of the family to GNPTG. Direct DNA sequence analysis identified two novel compound heterozygous mutations, c.471delC in exon 7 and IVS4-1G>C, in three patients. The two mutations cause frameshift and abnormal splicing, respectively, and represent the first series of GNPTG mutations in the Chinese population.
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Affiliation(s)
- Yong Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
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