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Wittenstein A, Caspi M, Rippin I, Elroy-Stein O, Eldar-Finkelman H, Thoms S, Rosin-Arbesfeld R. Nonsense mutation suppression is enhanced by targeting different stages of the protein synthesis process. PLoS Biol 2023; 21:e3002355. [PMID: 37943958 PMCID: PMC10684085 DOI: 10.1371/journal.pbio.3002355] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 11/28/2023] [Accepted: 09/29/2023] [Indexed: 11/12/2023] Open
Abstract
The introduction of premature termination codons (PTCs), as a result of splicing defects, insertions, deletions, or point mutations (also termed nonsense mutations), lead to numerous genetic diseases, ranging from rare neuro-metabolic disorders to relatively common inheritable cancer syndromes and muscular dystrophies. Over the years, a large number of studies have demonstrated that certain antibiotics and other synthetic molecules can act as PTC suppressors by inducing readthrough of nonsense mutations, thereby restoring the expression of full-length proteins. Unfortunately, most PTC readthrough-inducing agents are toxic, have limited effects, and cannot be used for therapeutic purposes. Thus, further efforts are required to improve the clinical outcome of nonsense mutation suppressors. Here, by focusing on enhancing readthrough of pathogenic nonsense mutations in the adenomatous polyposis coli (APC) tumor suppressor gene, we show that disturbing the protein translation initiation complex, as well as targeting other stages of the protein translation machinery, enhances both antibiotic and non-antibiotic-mediated readthrough of nonsense mutations. These findings strongly increase our understanding of the mechanisms involved in nonsense mutation readthrough and facilitate the development of novel therapeutic targets for nonsense suppression to restore protein expression from a large variety of disease-causing mutated transcripts.
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Affiliation(s)
- Amnon Wittenstein
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michal Caspi
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ido Rippin
- The Department of Human Molecular Genetics & Biochemistry School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Orna Elroy-Stein
- Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Hagit Eldar-Finkelman
- The Department of Human Molecular Genetics & Biochemistry School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Sven Thoms
- Biochemistry and Molecular Medicine, Medical School EWL, Bielefeld University, Bielefeld, Germany
| | - Rina Rosin-Arbesfeld
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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2
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Wang N, Zhang Y, Gedvilaite E, Loh JW, Lin T, Liu X, Liu CG, Kumar D, Donnelly R, Raymond K, Schuchman EH, Sleat DE, Lobel P, Xing J. Using whole-exome sequencing to investigate the genetic bases of lysosomal storage diseases of unknown etiology. Hum Mutat 2017; 38:1491-1499. [PMID: 28703315 DOI: 10.1002/humu.23291] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/04/2017] [Accepted: 07/08/2017] [Indexed: 12/17/2022]
Abstract
Lysosomes are membrane-bound, acidic eukaryotic cellular organelles that play important roles in the degradation of macromolecules. Mutations that cause the loss of lysosomal protein function can lead to a group of disorders categorized as the lysosomal storage diseases (LSDs). Suspicion of LSD is frequently based on clinical and pathologic findings, but in some cases, the underlying genetic and biochemical defects remain unknown. Here, we performed whole-exome sequencing (WES) on 14 suspected LSD cases to evaluate the feasibility of using WES for identifying causal mutations. By examining 2,157 candidate genes potentially associated with lysosomal function, we identified eight variants in five genes as candidate disease-causing variants in four individuals. These included both known and novel mutations. Variants were corroborated by targeted sequencing and, when possible, functional assays. In addition, we identified nonsense mutations in two individuals in genes that are not known to have lysosomal function. However, mutations in these genes could have resulted in phenotypes that were diagnosed as LSDs. This study demonstrates that WES can be used to identify causal mutations in suspected LSD cases. We also demonstrate cases where a confounding clinical phenotype may potentially reflect more than one lysosomal protein defect.
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Affiliation(s)
- Nan Wang
- Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Yeting Zhang
- Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey.,Human Genetics Institute of New Jersey, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Erika Gedvilaite
- Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Jui Wan Loh
- Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Timothy Lin
- Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Xiuping Liu
- Sequencing and ncRNA Program, Department of Experimental Therapeutics, The University of Texas-MD Anderson Cancer Center, Houston, Texas
| | - Chang-Gong Liu
- Sequencing and ncRNA Program, Department of Experimental Therapeutics, The University of Texas-MD Anderson Cancer Center, Houston, Texas
| | - Dibyendu Kumar
- Waksman Institute of Microbiology, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Robert Donnelly
- Molecular Resource Facility at Rutgers, New Jersey Medical School, Newark, New Jersey
| | - Kimiyo Raymond
- Department of Laboratory Medicine and Pathology, Biochemical Genetics Laboratory, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Edward H Schuchman
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - David E Sleat
- Center for Advanced Biotechnology and Medicine, Rutgers, the State University of New Jersey, Piscataway, New Jersey.,Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Peter Lobel
- Center for Advanced Biotechnology and Medicine, Rutgers, the State University of New Jersey, Piscataway, New Jersey.,Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Jinchuan Xing
- Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey.,Human Genetics Institute of New Jersey, Rutgers, the State University of New Jersey, Piscataway, New Jersey
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3
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Tuttolomondo A, Simonetta I, Duro G, Pecoraro R, Miceli S, Colomba P, Zizzo C, Nucera A, Daidone M, Di Chiara T, Scaglione R, Della Corte V, Corpora F, Vogiatzis D, Pinto A. Inter-familial and intra-familial phenotypic variability in three Sicilian families with Anderson-Fabry disease. Oncotarget 2017; 8:61415-61424. [PMID: 28977874 PMCID: PMC5617434 DOI: 10.18632/oncotarget.18250] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 04/11/2017] [Indexed: 12/27/2022] Open
Abstract
Background Anderson-Fabry disease (AFD) is an inborn lysosomal enzymopathy resulting from the deficient or absent activity of the lysosomal exogalactohydrolase, α-galactosidase A. This deficiency, results in the altered metabolism of glycosphingolipids which leads to their accumulation in lysosomes, thus to cellular and vascular dysfunction. To date, numerous mutations (according to recent data more than 1000 mutations) have been reported in the GLA intronic and exonic mutations. Traditionally, clinical manifestations are more severe in affected hemizygous males than in females. Nevertheless, recent studies have described severe organ dysfunction in women. The aim of the study This study reports clinical, biochemical, and molecular findings of the members of three Sicilian families. The clinical history of these patients highlights a remarkable interfamilial and intrafamilial phenotypic variability which characterizes Fabry disease relative to target organs and severity of clinical manifestations. Discussion Our findings, in agreement with previous data, report a little genotype-phenotype correlation for the disease, suggesting that the wide phenotypic variability of Anderson-Fabry disease is not completely ascribable to different gene mutations but other factors and mechanisms seem to be involved in the pathogenesis and clinical expression of the disease. Moreover, this study emphasies the importance of pedigree analysis in the family of each proband for identifying other possibly affected relatives.
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Affiliation(s)
- Antonino Tuttolomondo
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
| | - Irene Simonetta
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
| | - Giovanni Duro
- CNR-IBIM: Institute of Biomedicine and Molecular Immunology "A. Monroy" Palermo, Palermo, Italy
| | - Rosaria Pecoraro
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
| | - Salvatore Miceli
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
| | - Paolo Colomba
- CNR-IBIM: Institute of Biomedicine and Molecular Immunology "A. Monroy" Palermo, Palermo, Italy
| | - Carmela Zizzo
- CNR-IBIM: Institute of Biomedicine and Molecular Immunology "A. Monroy" Palermo, Palermo, Italy
| | - Antonia Nucera
- Stroke Unit, Neurology, Saint Andrea Hospital, La Spezia, Italy.,Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada
| | - Mario Daidone
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
| | - Tiziana Di Chiara
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
| | - Rosario Scaglione
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
| | - Vittoriano Della Corte
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
| | - Francesca Corpora
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
| | - Danai Vogiatzis
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
| | - Antonio Pinto
- U.O.C di Medicina Interna con Stroke Care, Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy
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4
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Caspi M, Firsow A, Rajkumar R, Skalka N, Moshkovitz I, Munitz A, Pasmanik-Chor M, Greif H, Megido D, Kariv R, Rosenberg DW, Rosin-Arbesfeld R. A flow cytometry-based reporter assay identifies macrolide antibiotics as nonsense mutation read-through agents. J Mol Med (Berl) 2015; 94:469-82. [PMID: 26620677 DOI: 10.1007/s00109-015-1364-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 10/24/2015] [Accepted: 11/03/2015] [Indexed: 01/01/2023]
Abstract
UNLABELLED A large number of human diseases are caused by nonsense mutations. These mutations result in premature protein termination and the expression of truncated, usually nonfunctional products. A promising therapeutic strategy for patients suffering from premature termination codon (PTC)-mediated disorders is to suppress the nonsense mutation and restore the expression of the affected protein. Such a suppression approach using specific antibiotics and other read-through promoting agents has been shown to suppress PTCs and restore the production of several important proteins. Here, we report the establishment of a novel, rapid, and very efficient method for screening stop-codon read-through agents. We also show that, in both mammalian cells and in a transgenic mouse model, distinct members of the macrolide antibiotic family can induce read-through of disease-causing stop codons leading to re-expression of several key proteins and to reduced disease phenotypes. Taken together, our results may help in the identification and characterization of well-needed customized pharmaceutical PTC suppression agents. KEY MESSAGES Establishment of a flow cytometry-based reporter assay to identify nonsense mutation read-through agents. Macrolide antibiotics can induce read-through of disease-causing stop codons. Macrolide-induced protein restoration can alleviate disease-like phenotypes.
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Affiliation(s)
- Michal Caspi
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Ramat-Aviv, 69978, Tel Aviv, Israel
| | - Anastasia Firsow
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Ramat-Aviv, 69978, Tel Aviv, Israel
| | - Raja Rajkumar
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Ramat-Aviv, 69978, Tel Aviv, Israel
| | - Nir Skalka
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Ramat-Aviv, 69978, Tel Aviv, Israel
| | - Itay Moshkovitz
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Ramat-Aviv, 69978, Tel Aviv, Israel
| | - Ariel Munitz
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Ramat-Aviv, 69978, Tel Aviv, Israel
| | - Metsada Pasmanik-Chor
- Bioinformatics Unit, G.S.W. Faculty of Life Science, Tel Aviv University, Tel Aviv, Israel
| | | | | | - Revital Kariv
- Department of Gastroenterology, Tel Aviv Sourasky Medical Center, Tel Aviv, 64239, Israel
| | - Daniel W Rosenberg
- Center for Molecular Medicine, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Rina Rosin-Arbesfeld
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Ramat-Aviv, 69978, Tel Aviv, Israel.
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5
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Kingma SDK, Bodamer OA, Wijburg FA. Epidemiology and diagnosis of lysosomal storage disorders; challenges of screening. Best Pract Res Clin Endocrinol Metab 2015; 29:145-57. [PMID: 25987169 DOI: 10.1016/j.beem.2014.08.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The lysosomal storage disorders (LSDs) are a group of genetic disorders resulting from defective lysosomal metabolism and subsequent accumulation of substrates. Patients present with a large phenotypic spectrum of disease manifestations that are generally not specific for LSDs, leading to considerable diagnostic delay and missed cases. Introduction of new disease modifying therapies for LSDs has made early diagnosis a priority. Increased awareness, but particularly the introduction of screening programs allow for early diagnosis and timely initiation of treatment. This review will provide insight into the epidemiology and diagnostic process for LSDs. In addition, challenges for carrier screening, high-risk screening and newborn population screening for LSDs are discussed.
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Affiliation(s)
- Sandra D K Kingma
- Department of Pediatrics and Amsterdam Lysosome Center 'Sphinx', Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
| | - Olaf A Bodamer
- Division of Clinical and Translational Genetics, Department of Human Genetics, University of Miami, Miller School of Medicine, 1501 NW 10th Avenue, Miami, FL 33136, USA.
| | - Frits A Wijburg
- Department of Pediatrics and Amsterdam Lysosome Center 'Sphinx', Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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6
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Rigoldi M, Concolino D, Morrone A, Pieruzzi F, Ravaglia R, Furlan F, Santus F, Strisciuglio P, Torti G, Parini R. Intrafamilial phenotypic variability in four families with Anderson-Fabry disease. Clin Genet 2013; 86:258-63. [PMID: 23980562 DOI: 10.1111/cge.12261] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 08/21/2013] [Accepted: 08/21/2013] [Indexed: 11/26/2022]
Abstract
We analysed the clinical history of 16 hemizygous males affected by Anderson-Fabry Disease, from four families, to verify their intrafamilial phenotypic variability. Seven male patients, ranging from 26 to 61 years of age, died, whereas nine (age range 23-55) are alive. Eleven patients have undergone enzyme replacement therapy (ERT) for a period of 5-10 years. We have found a wide range of intrafamilial phenotypic variability in these families, both in terms of target-organs and severity of the disease. Overall, our findings confirm previous data from the literature showing a high degree of intrafamilial phenotypic variability in patients carrying the same mutation. Furthermore, our results underscore the difficulty in giving accurate prognostic information to patients during genetic counselling, both in terms of rate of disease progression and involvement of different organs, when such prognosis is solely based on the patient's family history.
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Affiliation(s)
- M Rigoldi
- Rare Metabolic Diseases Unit, San Gerardo Hospital, Monza, Italy
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7
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Goldmann T, Overlack N, Möller F, Belakhov V, van Wyk M, Baasov T, Wolfrum U, Nagel-Wolfrum K. A comparative evaluation of NB30, NB54 and PTC124 in translational read-through efficacy for treatment of an USH1C nonsense mutation. EMBO Mol Med 2012; 4:1186-99. [PMID: 23027640 PMCID: PMC3494875 DOI: 10.1002/emmm.201201438] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 08/17/2012] [Accepted: 08/22/2012] [Indexed: 12/22/2022] Open
Abstract
Translational read-through-inducing drugs (TRIDs) promote read-through of nonsense mutations, placing them in the spotlight of current gene-based therapeutic research. Here, we compare for the first time the relative efficacies of new-generation aminoglycosides NB30, NB54 and the chemical compound PTC124 on retinal toxicity and read-through efficacy of a nonsense mutation in the USH1C gene, which encodes the scaffold protein harmonin. This mutation causes the human Usher syndrome, the most common form of inherited deaf-blindness. We quantify read-through efficacy of the TRIDs in cell culture and show the restoration of harmonin function. We do not observe significant differences in the read-through efficacy of the TRIDs in retinal cultures; however, we show an excellent biocompatibility in retinal cultures with read-through versus toxicity evidently superior for NB54 and PTC124. In addition, in vivo administration of NB54 and PTC124 induced recovery of the full-length harmonin a1 with the same efficacy. The high biocompatibilities combined with the sustained read-through efficacies of these drugs emphasize the potential of NB54 and PTC124 in treating nonsense mutation-based retinal disorders.
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Affiliation(s)
- Tobias Goldmann
- Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University of Mainz, Germany
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8
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Lübke T, Lobel P, Sleat DE. Proteomics of the lysosome. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:625-35. [PMID: 18977398 DOI: 10.1016/j.bbamcr.2008.09.018] [Citation(s) in RCA: 201] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Revised: 09/24/2008] [Accepted: 09/30/2008] [Indexed: 01/05/2023]
Abstract
Defects in lysosomal function have been associated with numerous monogenic human diseases typically classified as lysosomal storage diseases. However, there is increasing evidence that lysosomal proteins are also involved in more widespread human diseases including cancer and Alzheimer disease. Thus, there is a continuing interest in understanding the cellular functions of the lysosome and an emerging approach to this is the identification of its constituent proteins by proteomic analyses. To date, the mammalian lysosome has been shown to contain approximately 60 soluble luminal proteins and approximately 25 transmembrane proteins. However, recent proteomic studies based upon affinity purification of soluble components or subcellular fractionation to obtain both soluble and membrane components suggest that there may be many more of both classes of protein resident within this organelle than previously appreciated. Discovery of such proteins has important implications for understanding the function and the dynamics of the lysosome but can also lead the way towards the discovery of the genetic basis for human diseases of hitherto unknown etiology. Here, we describe current approaches to lysosomal proteomics and data interpretation and review the new lysosomal proteins that have recently emerged from such studies.
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Affiliation(s)
- Torben Lübke
- Zentrum Biochemie und Molekulare Zellbiologie, Abteilung Biochemie II, Georg-August Universität Göttingen, 37073 Göttingen, Germany
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9
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Sleat DE, El-Banna M, Sohar I, Kim KH, Dobrenis K, Walkley SU, Lobel P. Residual levels of tripeptidyl-peptidase I activity dramatically ameliorate disease in late-infantile neuronal ceroid lipofuscinosis. Mol Genet Metab 2008; 94:222-33. [PMID: 18343701 PMCID: PMC2467442 DOI: 10.1016/j.ymgme.2008.01.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 01/18/2008] [Accepted: 01/19/2008] [Indexed: 10/22/2022]
Abstract
Classical late-infantile neuronal ceroid lipofuscinosis (LINCL) is a hereditary neurodegenerative disease of childhood that is caused by mutations in the gene (CLN2) encoding the lysosomal protease tripeptidyl-peptidase I (TPPI). LINCL is fatal and there is no treatment of demonstrated efficacy in affected children but preclinical studies with AAV-mediated gene therapy have demonstrated promise in a mouse model. Here, we have generated mouse CLN2-mutants that express different amounts of TPPI activity to benchmark levels required for therapeutic benefits. Approximately 3% of normal TPPI activity in brain delayed disease onset and doubled lifespan to a median of approximately 9 months compared to mice expressing approximately 0.2% of normal levels. Expression of 6% of normal TPPI activity dramatically attenuated disease, with a median lifespan of approximately 20 months which approaches that of unaffected mice. While the lifespan of this hypomorph is shortened, disease is late-onset, less severe and progresses slowly compared to mice expressing lower TPPI levels. For gene therapy and other approaches that restore enzyme activity, these results suggest that 6% of normal TPPI activity throughout the CNS of affected individuals will provide a significant therapeutic benefit but higher levels will be required to cure this disease.
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Affiliation(s)
- David E Sleat
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ 08854, USA.
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10
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Kellermayer R. Translational readthrough induction of pathogenic nonsense mutations. Eur J Med Genet 2006; 49:445-50. [PMID: 16740421 DOI: 10.1016/j.ejmg.2006.04.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Accepted: 04/27/2006] [Indexed: 11/08/2022]
Abstract
The treatment of genetic disorders is one of the biggest challenges lying ahead of modern medicine. While major advancements have been made in gene therapy, it is still far from achieving clinical success. However, other potential methods for treating single gene related diseases have also emerged recently. One such approach is the suppression of pathogenic nonsense mutations through inducing translational readthrough of the in-frame premature stop mutation. Aminoglycosides were the first drugs that gave promising results in this respect. This report provides a brief overview on the past, present and potential future of this pharmacogenetic approach.
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Affiliation(s)
- Richard Kellermayer
- Department of Medical Genetics and Child Development, University of Pécs, József A. u. 7., 7623 Pécs, Hungary.
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11
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Jeyakumar M, Dwek RA, Butters TD, Platt FM. Storage solutions: treating lysosomal disorders of the brain. Nat Rev Neurosci 2005; 6:713-25. [PMID: 16049428 DOI: 10.1038/nrn1725] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Many neurodegenerative diseases are characterized by the accumulation of undegradable molecules in cells or at extracellular sites in the brain. One such family of diseases is the lysosomal storage disorders, which result from defects in various aspects of lysosomal function. Until recently, there was little prospect of treating storage diseases involving the CNS. However, recent progress has been made in understanding these conditions and in translating the findings into experimental therapies. We review the developments in this field and discuss the similarities in pathological features between these diseases and some more common neurodegenerative disorders.
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12
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Froissart R, Moreira da Silva I, Guffon N, Bozon D, Maire I. Mucopolysaccharidosis type II--genotype/phenotype aspects. ACTA PAEDIATRICA (OSLO, NORWAY : 1992). SUPPLEMENT 2003; 91:82-7. [PMID: 12572848 DOI: 10.1111/j.1651-2227.2002.tb03116.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
UNLABELLED Establishing correlations between a patient's genotype and clinical phenotype is based on the assumption that the same clinical consequences will be observed in individuals with the same residual function of a specific metabolic step. In mucopolysaccharidosis type II (MPS II; Hunter disease), patients present with a wide clinical spectrum. Furthermore, current methods for measuring the activity of the deficient enzyme in MPS II--iduronate-2-sulphatase (IDS)--are insufficiently sensitive to differentiate between complete absence of activity and the presence of residual activity. Attempts have therefore been made to establish genotype-phenotype correlations in order to explain the large degree of heterogeneity and to serve as a better guide to prognosis on which to base genetic counselling and treatment options. Using MPS II as an example, this paper illustrates the difficulties and potential advantages of determining genotype-phenotype correlations in lysosomal storage diseases. The response of patients with MPS II to allogenic bone marrow transplantation provides some insight into the likely influence of certain genotypes on therapeutic efficacy. CONCLUSIONS Evaluation of residual activity of IDS in MPS II using gene analysis, expression studies and transcript analysis does not always allow prediction of a patient's phenotype. The variable response to bone marrow transplantation, however, illustrates the potential importance of determining the genotype for selecting the most appropriate therapy for individual patients.
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Affiliation(s)
- R Froissart
- Paediatric Biochemistry Department, Debrousse Hospital, Lyon, France
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13
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Sawkar AR, Cheng WC, Beutler E, Wong CH, Balch WE, Kelly JW. Chemical chaperones increase the cellular activity of N370S beta -glucosidase: a therapeutic strategy for Gaucher disease. Proc Natl Acad Sci U S A 2002; 99:15428-33. [PMID: 12434014 PMCID: PMC137733 DOI: 10.1073/pnas.192582899] [Citation(s) in RCA: 429] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2002] [Indexed: 11/18/2022] Open
Abstract
Gaucher disease is a lysosomal storage disorder caused by deficient lysosomal beta-glucosidase (beta-Glu) activity. A marked decrease in enzyme activity results in progressive accumulation of the substrate (glucosylceramide) in macrophages, leading to hepatosplenomegaly, anemia, skeletal lesions, and sometimes CNS involvement. Enzyme replacement therapy for Gaucher disease is costly and relatively ineffective for CNS involvement. Chemical chaperones have been shown to stabilize various proteins against misfolding, increasing proper trafficking from the endoplasmic reticulum. We report herein that the addition of subinhibitory concentrations (10 microM) of N-(n-nonyl)deoxynojirimycin (NN-DNJ) to a fibroblast culture medium for 9 days leads to a 2-fold increase in the activity of N370S beta-Glu, the most common mutation causing Gaucher disease. Moreover, the increased activity persists for at least 6 days after the withdrawal of the putative chaperone. The NN-DNJ chaperone also increases WT beta-Glu activity, but not that of L444P, a less prevalent Gaucher disease variant. Incubation of isolated soluble WT enzyme with NN-DNJ reveals that beta-Glu is stabilized against heat denaturation in a dose-dependent fashion. We propose that NN-DNJ chaperones beta-Glu folding at neutral pH, thus allowing the stabilized enzyme to transit from the endoplasmic reticulum to the Golgi, enabling proper trafficking to the lysosome. Clinical data suggest that a modest increase in beta-Glu activity may be sufficient to achieve a therapeutic effect.
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Affiliation(s)
- Anu R Sawkar
- Department of Chemistry and The Skaggs Institute of Chemical Biology, La Jolla, CA 92037, USA
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Jung V. Fast forwarding pharmacogenomics. Pharmacogenomics 2002; 3:281-5. [PMID: 12052137 DOI: 10.1517/14622416.3.3.281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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