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Walsh DJ, Rees JR, Mehra S, Bourkas MEC, Kaczmarczyk L, Stuart E, Jackson WS, Watts JC, Supattapone S. Anti-prion drugs do not improve survival in novel knock-in models of inherited prion disease. PLoS Pathog 2024; 20:e1012087. [PMID: 38557815 PMCID: PMC10984475 DOI: 10.1371/journal.ppat.1012087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 03/01/2024] [Indexed: 04/04/2024] Open
Abstract
Prion diseases uniquely manifest in three distinct forms: inherited, sporadic, and infectious. Wild-type prions are responsible for the sporadic and infectious versions, while mutant prions cause inherited variants like fatal familial insomnia (FFI) and familial Creutzfeldt-Jakob disease (fCJD). Although some drugs can prolong prion incubation times up to four-fold in rodent models of infectious prion diseases, no effective treatments for FFI and fCJD have been found. In this study, we evaluated the efficacy of various anti-prion drugs on newly-developed knock-in mouse models for FFI and fCJD. These models express bank vole prion protein (PrP) with the pathogenic D178N and E200K mutations. We applied various drug regimens known to be highly effective against wild-type prions in vivo as well as a brain-penetrant compound that inhibits mutant PrPSc propagation in vitro. None of the regimens tested (Anle138b, IND24, Anle138b + IND24, cellulose ether, and PSCMA) significantly extended disease-free survival or prevented mutant PrPSc accumulation in either knock-in mouse model, despite their ability to induce strain adaptation of mutant prions. Our results show that anti-prion drugs originally developed to treat infectious prion diseases do not necessarily work for inherited prion diseases, and that the recombinant sPMCA is not a reliable platform for identifying compounds that target mutant prions. This work underscores the need to develop therapies and validate screening assays specifically for mutant prions, as well as anti-prion strategies that are not strain-dependent.
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Affiliation(s)
- Daniel J. Walsh
- Department of Biochemistry and Cell Biology Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Judy R. Rees
- Department of Epidemiology Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- Department of Community and Family Medicine Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Surabhi Mehra
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Matthew E. C. Bourkas
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Lech Kaczmarczyk
- Wallenberg Center for Molecular Medicine, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Erica Stuart
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Walker S. Jackson
- Wallenberg Center for Molecular Medicine, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Joel C. Watts
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Surachai Supattapone
- Department of Biochemistry and Cell Biology Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- Department of Medicine, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
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2
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Zayed M, Kook SH, Jeong BH. Potential Therapeutic Use of Stem Cells for Prion Diseases. Cells 2023; 12:2413. [PMID: 37830627 PMCID: PMC10571911 DOI: 10.3390/cells12192413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/02/2023] [Accepted: 10/05/2023] [Indexed: 10/14/2023] Open
Abstract
Prion diseases are neurodegenerative disorders that are progressive, incurable, and deadly. The prion consists of PrPSc, the misfolded pathogenic isoform of the cellular prion protein (PrPC). PrPC is involved in a variety of physiological functions, including cellular proliferation, adhesion, differentiation, and neural development. Prion protein is expressed on the membrane surface of a variety of stem cells (SCs), where it plays an important role in the pluripotency and self-renewal matrix, as well as in SC differentiation. SCs have been found to multiply the pathogenic form of the prion protein, implying their potential as an in vitro model for prion diseases. Furthermore, due to their capability to self-renew, differentiate, immunomodulate, and regenerate tissue, SCs are prospective cell treatments in many neurodegenerative conditions, including prion diseases. Regenerative medicine has become a new revolution in disease treatment in recent years, particularly with the introduction of SC therapy. Here, we review the data demonstrating prion diseases' biology and molecular mechanism. SC biology, therapeutic potential, and its role in understanding prion disease mechanisms are highlighted. Moreover, we summarize preclinical studies that use SCs in prion diseases.
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Affiliation(s)
- Mohammed Zayed
- Korea Zoonosis Research Institute, Jeonbuk National University, Iksan 54531, Republic of Korea;
- Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics, Jeonbuk National University, Jeonju 54896, Republic of Korea
- Department of Surgery, College of Veterinary Medicine, South Valley University, Qena 83523, Egypt
| | - Sung-Ho Kook
- Department of Bioactive Material Sciences, Research Center of Bioactive Materials, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - Byung-Hoon Jeong
- Korea Zoonosis Research Institute, Jeonbuk National University, Iksan 54531, Republic of Korea;
- Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics, Jeonbuk National University, Jeonju 54896, Republic of Korea
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3
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Walsh DJ, Rees JR, Mehra S, Bourkas MEC, Kaczmarczyk L, Stuart E, Jackson WS, Watts JC, Supattapone S. Anti-prion drugs do not improve survival in knock-in models of inherited prion disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.28.559951. [PMID: 37808761 PMCID: PMC10557747 DOI: 10.1101/2023.09.28.559951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Prion diseases uniquely manifest in three distinct forms: inherited, sporadic, and infectious. Wild-type prions are responsible for the sporadic and infectious versions, while mutant prions cause inherited variants like fatal familial insomnia (FFI) and familial Creutzfeldt-Jakob disease (fCJD). Although some drugs can prolong prion incubation times up to four-fold in rodent models of infectious prion diseases, no effective treatments for FFI and fCJD have been found. In this study, we evaluated the efficacy of various anti-prion drugs on newly-developed knock-in mouse models for FFI and fCJD. These models express bank vole prion protein (PrP) with the pathogenic D178N and E200K mutations. We applied various drug regimens known to be highly effective against wild-type prions in vivo as well as a brain-penetrant compound that inhibits mutant PrP Sc propagation in vitro . None of the regimens tested (Anle138b, IND24, Anle138b + IND24, cellulose ether, and PSCMA) significantly extended disease-free survival or prevented mutant PrP Sc accumulation in either knock-in mouse model, despite their ability to induce strain adaptation of mutant prions. Paradoxically, the combination of Anle138b and IND24 appeared to accelerate disease by 16% and 26% in kiBVI E200K and kiBVI D178N mice, respectively, and accelerated the aggregation of mutant PrP molecules in vitro . Our results show that anti-prion drugs originally developed to treat infectious prion diseases do not necessarily work for inherited prion diseases, and that the recombinant sPMCA is not a reliable platform for identifying compounds that target mutant prions. This work underscores the need to develop therapies and validate screening assays specifically for mutant prions.
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4
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Eraña H, Díaz-Domínguez CM, Charco JM, Vidal E, González-Miranda E, Pérez-Castro MA, Piñeiro P, López-Moreno R, Sampedro-Torres-Quevedo C, Fernández-Veiga L, Tasis-Galarza J, Lorenzo NL, Santini-Santiago A, Lázaro M, García-Martínez S, Gonçalves-Anjo N, San-Juan-Ansoleaga M, Galarza-Ahumada J, Fernández-Muñoz E, Giler S, Valle M, Telling GC, Geijó M, Requena JR, Castilla J. Understanding the key features of the spontaneous formation of bona fide prions through a novel methodology that enables their swift and consistent generation. Acta Neuropathol Commun 2023; 11:145. [PMID: 37679832 PMCID: PMC10486007 DOI: 10.1186/s40478-023-01640-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/20/2023] [Indexed: 09/09/2023] Open
Abstract
Among transmissible spongiform encephalopathies or prion diseases affecting humans, sporadic forms such as sporadic Creutzfeldt-Jakob disease are the vast majority. Unlike genetic or acquired forms of the disease, these idiopathic forms occur seemingly due to a random event of spontaneous misfolding of the cellular PrP (PrPC) into the pathogenic isoform (PrPSc). Currently, the molecular mechanisms that trigger and drive this event, which occurs in approximately one individual per million each year, remain completely unknown. Modelling this phenomenon in experimental settings is highly challenging due to its sporadic and rare occurrence. Previous attempts to model spontaneous prion misfolding in vitro have not been fully successful, as the spontaneous formation of prions is infrequent and stochastic, hindering the systematic study of the phenomenon. In this study, we present the first method that consistently induces spontaneous misfolding of recombinant PrP into bona fide prions within hours, providing unprecedented possibilities to investigate the mechanisms underlying sporadic prionopathies. By fine-tuning the Protein Misfolding Shaking Amplification method, which was initially developed to propagate recombinant prions, we have created a methodology that consistently produces spontaneously misfolded recombinant prions in 100% of the cases. Furthermore, this method gives rise to distinct strains and reveals the critical influence of charged surfaces in this process.
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Affiliation(s)
- Hasier Eraña
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
- ATLAS Molecular Pharma S. L. Bizkaia Technology Park, 48160, Derio, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Carlos III National Health Institute, 28029, Madrid, Spain
| | - Carlos M Díaz-Domínguez
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Carlos III National Health Institute, 28029, Madrid, Spain
| | - Jorge M Charco
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
- ATLAS Molecular Pharma S. L. Bizkaia Technology Park, 48160, Derio, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Carlos III National Health Institute, 28029, Madrid, Spain
| | - Enric Vidal
- IRTA, Programa de Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), Campus de la Universitat Autònoma de Barcelona (UAB), Bellaterra, Catalonia, Spain
| | - Ezequiel González-Miranda
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Miguel A Pérez-Castro
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Patricia Piñeiro
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Rafael López-Moreno
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Cristina Sampedro-Torres-Quevedo
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Leire Fernández-Veiga
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Juan Tasis-Galarza
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Nuria L Lorenzo
- CIMUS Biomedical Research Institute and Department of Medical Sciences, University of Santiago de Compostela-IDIS, 15782, Santiago de Compostela, Spain
| | - Aileen Santini-Santiago
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Melisa Lázaro
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Sandra García-Martínez
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Nuno Gonçalves-Anjo
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Maitena San-Juan-Ansoleaga
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Josu Galarza-Ahumada
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Eva Fernández-Muñoz
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Samanta Giler
- IRTA, Programa de Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), Campus de la Universitat Autònoma de Barcelona (UAB), Bellaterra, Catalonia, Spain
| | - Mikel Valle
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain
| | - Glenn C Telling
- Prion Research Center (PRC), Colorado State University, Fort Collins, CO, 80523, USA
| | - Mariví Geijó
- Animal Health Department, NEIKER-Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Spain
| | - Jesús R Requena
- CIMUS Biomedical Research Institute and Department of Medical Sciences, University of Santiago de Compostela-IDIS, 15782, Santiago de Compostela, Spain
| | - Joaquín Castilla
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, 48160, Derio, Bizkaia, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Carlos III National Health Institute, 28029, Madrid, Spain.
- IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
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5
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Schwind AM, Walsh DJ, Burke CM, Supattapone S. Phospholipid cofactor solubilization inhibits formation of native prions. J Neurochem 2023; 166:875-884. [PMID: 37551010 PMCID: PMC10528465 DOI: 10.1111/jnc.15930] [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: 05/03/2023] [Revised: 07/05/2023] [Accepted: 07/25/2023] [Indexed: 08/09/2023]
Abstract
Cofactor molecules are required to generate infectious mammalian prions in vitro. Mouse and hamster prions appear to have different cofactor preferences: Whereas both mouse and hamster prions can use phosphatidylethanolamine (PE) as a prion cofactor, only hamster prions can also use single-stranded RNA as an alternative cofactor. Here, we investigated the effect of detergent solubilization on rodent prion formation in vitro. We discovered that detergents that can solubilize PE (n-octylglucoside, n-octylgalactoside, and CHAPS) inhibit mouse prion formation in serial protein misfolding cyclic amplification (sPMCA) reactions using bank vole brain homogenate substrate, whereas detergents that are unable to solubilize PE (Triton X-100 and IPEGAL) have no effect. For all three PE-solubilizing detergents, inhibition of RML mouse prion formation was only observed above the critical micellar concentration (CMC). Two other mouse prion strains, Me7 and 301C, were also inhibited by the three PE-solubilizing detergents but not by Triton X-100 or IPEGAL. In contrast, none of the detergents inhibited hamster prion formation in parallel sPMCA reactions using the same bank vole brain homogenate substrate. In reconstituted sPMCA reactions using purified substrates, n-octylglucoside inhibited hamster prion formation when immunopurified bank vole PrPC substrate was supplemented with brain phospholipid but not with RNA. Interestingly, phospholipid cofactor solubilization had no effect in sPMCA reactions using bacterially expressed recombinant PrP substrate, indicating that the inhibitory effect of solubilization requires PrPC post-translational modifications. Overall, these in vitro results show that the ability of PE to facilitate the formation of native but not recombinant prions requires phospholipid bilayer integrity, suggesting that membrane structure may play an important role in prion formation in vivo.
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Affiliation(s)
- Abigail M. Schwind
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, USA
| | - Daniel J. Walsh
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, USA
| | - Cassandra M. Burke
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, USA
| | - Surachai Supattapone
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, USA
- Department of Medicine, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, USA
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6
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Gunnels T, Shikiya RA, York TC, Block AJ, Bartz JC. Evidence for preexisting prion substrain diversity in a biologically cloned prion strain. PLoS Pathog 2023; 19:e1011632. [PMID: 37669293 PMCID: PMC10503715 DOI: 10.1371/journal.ppat.1011632] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/15/2023] [Accepted: 08/21/2023] [Indexed: 09/07/2023] Open
Abstract
Prion diseases are a group of inevitably fatal neurodegenerative disorders affecting numerous mammalian species, including Sapiens. Prions are composed of PrPSc, the disease specific conformation of the host encoded prion protein. Prion strains are operationally defined as a heritable phenotype of disease under controlled transmission conditions. Treatment of rodents with anti-prion drugs results in the emergence of drug-resistant prion strains and suggest that prion strains are comprised of a dominant strain and substrains. While much experimental evidence is consistent with this hypothesis, direct observation of substrains has not been observed. Here we show that replication of the dominant strain is required for suppression of a substrain. Based on this observation we reasoned that selective reduction of the dominant strain may allow for emergence of substrains. Using a combination of biochemical methods to selectively reduce drowsy (DY) PrPSc from biologically-cloned DY transmissible mink encephalopathy (TME)-infected brain resulted in the emergence of strains with different properties than DY TME. The selection methods did not occur during prion formation, suggesting the substrains identified preexisted in the DY TME-infected brain. We show that DY TME is biologically stable, even under conditions of serial passage at high titer that can lead to strain breakdown. Substrains therefore can exist under conditions where the dominant strain does not allow for substrain emergence suggesting that substrains are a common feature of prions. This observation has mechanistic implications for prion strain evolution, drug resistance and interspecies transmission.
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Affiliation(s)
- Tess Gunnels
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, United States of America
| | - Ronald A. Shikiya
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, United States of America
| | - Taylor C. York
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, United States of America
| | - Alyssa J. Block
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, United States of America
| | - Jason C. Bartz
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, United States of America
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7
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Walsh DJ, Schwind AM, Noble GP, Supattapone S. Conformational diversity in purified prions produced in vitro. PLoS Pathog 2023; 19:e1011083. [PMID: 36626391 PMCID: PMC9870145 DOI: 10.1371/journal.ppat.1011083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/23/2023] [Accepted: 12/23/2022] [Indexed: 01/11/2023] Open
Abstract
Prion diseases are caused by misfolding of either wild-type or mutant forms of the prion protein (PrP) into self-propagating, pathogenic conformers, collectively termed PrPSc. Both wild-type and mutant PrPSc molecules exhibit conformational diversity in vivo, but purified prions generated by the serial protein misfolding cyclic amplification (sPMCA) technique do not display this same diversity in vitro. This discrepancy has left a gap in our understanding of how conformational diversity arises at the molecular level in both types of prions. Here, we use continuous shaking instead of sPMCA to generate conformationally diverse purified prions in vitro. Using this approach, we show for the first time that wild type prions initially seeded by different native strains can propagate as metastable PrPSc conformers with distinguishable strain properties in purified reactions containing a single active cofactor. Propagation of these metastable PrPSc conformers requires appropriate shaking conditions, and changes in these conditions cause all the different PrPSc conformers to converge irreversibly into the same single conformer as that produced in sPMCA reactions. We also use continuous shaking to show that two mutant PrP molecules with different pathogenic point mutations (D177N and E199K) adopt distinguishable PrPSc conformations in reactions containing pure protein substrate without cofactors. Unlike wild-type prions, the conformations of mutant prions appear to be dictated by substrate sequence rather than seed conformation. Overall, our studies using purified substrates in shaking reactions show that wild-type and mutant prions use fundamentally different mechanisms to generate conformational diversity at the molecular level.
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Affiliation(s)
- Daniel J. Walsh
- Department of Biochemistry Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Abigail M. Schwind
- Department of Biochemistry Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Geoffrey P. Noble
- Department of Biochemistry Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Surachai Supattapone
- Department of Biochemistry Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- Department of Medicine, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
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8
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Essential Components of Synthetic Infectious Prion Formation De Novo. Biomolecules 2022; 12:biom12111694. [DOI: 10.3390/biom12111694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/08/2022] [Accepted: 11/11/2022] [Indexed: 11/17/2022] Open
Abstract
Prion diseases are a class of neurodegenerative diseases that are uniquely infectious. Whilst their general replication mechanism is well understood, the components required for the formation and propagation of highly infectious prions are poorly characterized. The protein-only hypothesis posits that the prion protein (PrP) is the only component of the prion; however, additional co-factors are required for its assembly into infectious prions. These can be provided by brain homogenate, but synthetic lipids and non-coding RNA have also been used in vitro. Here, we review a range of experimental approaches, which generate PrP amyloid assemblies de novo. These synthetic PrP assemblies share some, but not necessarily all, properties of genuine infectious prions. We will discuss the different experimental approaches, how a prion is defined, the non-protein requirements of a prion, and provide an overview of the current state of prion amplification and generation in vitro.
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9
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Mercer RCC, Harris DA. Mechanisms of prion-induced toxicity. Cell Tissue Res 2022; 392:81-96. [PMID: 36070155 DOI: 10.1007/s00441-022-03683-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 08/30/2022] [Indexed: 11/02/2022]
Abstract
Prion diseases are devastating neurodegenerative diseases caused by the structural conversion of the normally benign prion protein (PrPC) to an infectious, disease-associated, conformer, PrPSc. After decades of intense research, much is known about the self-templated prion conversion process, a phenomenon which is now understood to be operative in other more common neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. In this review, we provide the current state of knowledge concerning a relatively poorly understood aspect of prion diseases: mechanisms of neurotoxicity. We provide an overview of proposed functions of PrPC and its interactions with other extracellular proteins in the central nervous system, in vivo and in vitro models used to delineate signaling events downstream of prion propagation, the application of omics technologies, and the emerging appreciation of the role played by non-neuronal cell types in pathogenesis.
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Affiliation(s)
- Robert C C Mercer
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA.
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10
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Ma J, Zhang J, Yan R. Recombinant Mammalian Prions: The “Correctly” Misfolded Prion Protein Conformers. Viruses 2022; 14:v14091940. [PMID: 36146746 PMCID: PMC9504972 DOI: 10.3390/v14091940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/22/2022] [Accepted: 08/27/2022] [Indexed: 11/17/2022] Open
Abstract
Generating a prion with exogenously produced recombinant prion protein is widely accepted as the ultimate proof of the prion hypothesis. Over the years, a plethora of misfolded recPrP conformers have been generated, but despite their seeding capability, many of them have failed to elicit a fatal neurodegenerative disorder in wild-type animals like a naturally occurring prion. The application of the protein misfolding cyclic amplification technique and the inclusion of non-protein cofactors in the reaction mixture have led to the generation of authentic recombinant prions that fully recapitulate the characteristics of native prions. Together, these studies reveal that recPrP can stably exist in a variety of misfolded conformations and when inoculated into wild-type animals, misfolded recPrP conformers cause a wide range of outcomes, from being completely innocuous to lethal. Since all these recPrP conformers possess seeding capabilities, these results clearly suggest that seeding activity alone is not equivalent to prion activity. Instead, authentic prions are those PrP conformers that are not only heritable (the ability to seed the conversion of normal PrP) but also pathogenic (the ability to cause fatal neurodegeneration). The knowledge gained from the studies of the recombinant prion is important for us to understand the pathogenesis of prion disease and the roles of misfolded proteins in other neurodegenerative disorders.
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11
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Naeimi WR, Serio TR. Beyond Amyloid Fibers: Accumulation, Biological Relevance, and Regulation of Higher-Order Prion Architectures. Viruses 2022; 14:v14081635. [PMID: 35893700 PMCID: PMC9332770 DOI: 10.3390/v14081635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 07/14/2022] [Accepted: 07/23/2022] [Indexed: 12/19/2022] Open
Abstract
The formation of amyloid fibers is associated with a diverse range of disease and phenotypic states. These amyloid fibers often assemble into multi-protofibril, high-order architectures in vivo and in vitro. Prion propagation in yeast, an amyloid-based process, represents an attractive model to explore the link between these aggregation states and the biological consequences of amyloid dynamics. Here, we integrate the current state of knowledge, highlight opportunities for further insight, and draw parallels to more complex systems in vitro. Evidence suggests that high-order fibril architectures are present ex vivo from disease relevant environments and under permissive conditions in vivo in yeast, including but not limited to those leading to prion formation or instability. The biological significance of these latter amyloid architectures or how they may be regulated is, however, complicated by inconsistent experimental conditions and analytical methods, although the Hsp70 chaperone Ssa1/2 is likely involved. Transition between assembly states could form a mechanistic basis to explain some confounding observations surrounding prion regulation but is limited by a lack of unified methodology to biophysically compare these assembly states. Future exciting experimental entryways may offer opportunities for further insight.
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12
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Block AJ, Bartz JC. Prion strains: shining new light on old concepts. Cell Tissue Res 2022; 392:113-133. [PMID: 35796874 DOI: 10.1007/s00441-022-03665-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/23/2022] [Indexed: 02/04/2023]
Abstract
Prion diseases are a group of inevitably fatal neurodegenerative disorders affecting numerous mammalian species, including humans. The existence of heritable phenotypes of disease in the natural host suggested that prions exist as distinct strains. Transmission of sheep scrapie to rodent models accelerated prion research, resulting in the isolation and characterization of numerous strains with distinct characteristics. These strains are grouped into categories based on the incubation period of disease in different strains of mice and also by how stable the strain properties were upon serial passage. These classical studies defined the host and agent parameters that affected strain properties, and, prior to the advent of the prion hypothesis, strain properties were hypothesized to be the result of mutations in a nucleic acid genome of a conventional pathogen. The development of the prion hypothesis challenged the paradigm of infectious agents, and, initially, the existence of strains was difficult to reconcile with a protein-only agent. In the decades since, much evidence has revealed how a protein-only infectious agent can perform complex biological functions. The prevailing hypothesis is that strain-specific conformations of PrPSc encode prion strain diversity. This hypothesis can provide a mechanism to explain the observed strain-specific differences in incubation period of disease, biochemical properties of PrPSc, tissue tropism, and subcellular patterns of pathology. This hypothesis also explains how prion strains mutate, evolve, and adapt to new species. These concepts are applicable to prion-like diseases such as Parkinson's and Alzheimer's disease, where evidence of strain diversity is beginning to emerge.
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Affiliation(s)
- Alyssa J Block
- Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE, 68178, USA
| | - Jason C Bartz
- Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE, 68178, USA.
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13
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Carta M, Aguzzi A. Molecular foundations of prion strain diversity. Curr Opin Neurobiol 2021; 72:22-31. [PMID: 34416480 DOI: 10.1016/j.conb.2021.07.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/09/2021] [Accepted: 07/14/2021] [Indexed: 12/15/2022]
Abstract
Despite being caused by a single protein, prion diseases are strikingly heterogenous. Individual prion variants, known as strains, possess distinct biochemical properties, form aggregates with characteristic morphologies and preferentially seed certain brain regions, causing markedly different disease phenotypes. Strain diversity is determined by protein structure, post-translational modifications and the presence of extracellular matrix components, with single amino acid substitutions or altered protein glycosylation exerting dramatic effects. Here, we review recent advances in the study of prion strains and discuss how a deeper knowledge of the molecular origins of strain heterogeneity is providing a foundation for the development of anti-prion therapeutics.
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Affiliation(s)
- Manfredi Carta
- Institute of Neuropathology, University Hospital of Zurich, University of Zurich, Schmelzbergstrasse 12, 8091 Zurich, Switzerland
| | - Adriano Aguzzi
- Institute of Neuropathology, University Hospital of Zurich, University of Zurich, Schmelzbergstrasse 12, 8091 Zurich, Switzerland.
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14
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Bartz JC. Environmental and host factors that contribute to prion strain evolution. Acta Neuropathol 2021; 142:5-16. [PMID: 33899132 PMCID: PMC8932343 DOI: 10.1007/s00401-021-02310-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 02/08/2023]
Abstract
Prions are novel pathogens that are composed entirely of PrPSc, the self-templating conformation of the host prion protein, PrPC. Prion strains are operationally defined as a heritable phenotype of disease that are encoded by strain-specific conformations of PrPSc. The factors that influence the relative distribution of strains in a population are only beginning to be understood. For prions with an infectious etiology, environmental factors, such as strain-specific binding to surfaces and resistance to weathering, can influence which strains are available for transmission to a naïve host. Strain-specific differences in efficiency of infection by natural routes of infection can also select for prion strains. The host amino acid sequence of PrPC has the greatest effect on dictating the repertoire of prion strains. The relative abundance of PrPC, post-translational modifications of PrPC and cellular co-factors involved in prion conversion can also provide conditions that favor the prevalence of a subset of prion strains. Additionally, prion strains can interfere with each other, influencing the emergence of a dominant strain. Overall, both environmental and host factors may influence the repertoire and distribution of strains within a population.
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Affiliation(s)
- Jason C Bartz
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, 2500 California Plaza, Omaha, NE, 68178, USA.
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15
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Evidence of distinct α-synuclein strains underlying disease heterogeneity. Acta Neuropathol 2021; 142:73-86. [PMID: 32440702 DOI: 10.1007/s00401-020-02163-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/14/2020] [Accepted: 05/15/2020] [Indexed: 12/27/2022]
Abstract
Synucleinopathies are a group of neurodegenerative disorders caused by the misfolding and self-templating of the protein α-synuclein, or the formation of α-synuclein prions. Each disorder differs by age of onset, presenting clinical symptoms, α-synuclein inclusion morphology, and neuropathological distribution. Explaining this disease-specific variability, the strain hypothesis postulates that each prion disease is encoded by a distinct conformation of the misfolded protein, and therefore, each synucleinopathy is caused by a unique α-synuclein structure. This review discusses the current data supporting the role of α-synuclein strains in disease heterogeneity. Several in vitro and in vivo models exist for evaluating strain behavior, however, as the focus of this article is to compare strains across synucleinopathy patients, our discussion predominantly focuses on the two models most commonly used for this purpose: the α-syn140*A53T-YFP cell line and the TgM83+/- mouse model. Here we define each strain based on biochemical stability, ability to propagate in α-syn140-YFP cell lines, and incubation period, inclusion morphology and distribution, and neurological signs in TgM83+/- mice.
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16
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Soto P, Claflin IA, Bursott AL, Schwab-McCoy AD, Bartz JC. Cellular prion protein gene polymorphisms linked to differential scrapie susceptibility correlate with distinct residue connectivity between secondary structure elements. J Biomol Struct Dyn 2021; 39:129-139. [PMID: 31900058 PMCID: PMC7340567 DOI: 10.1080/07391102.2019.1708794] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The conformational conversion of the cellular prion protein (PrPC) to the misfolded and aggregated isoform, termed scrapie prion protein (PrPSc), is key to the development of a group of neurodegenerative diseases known as transmissible spongiform encephalopathies (TSEs). Although the conversion mechanism is not fully understood, the role of gene polymorphisms in varying susceptibilities to prion diseases is well established. In ovine, specific gene polymorphisms in PrPC alter prion disease susceptibility: the Valine136-Glutamine171 variant (Susceptible structure) displays high susceptibility to classical scrapie while the Alanine136-Arginine171 variant (Resistant structure) displays reduced susceptibility. The opposite trend has been reported in atypical scrapie. Despite the differentiation between classical and atypical scrapie, a complete understanding of the effect of polymorphisms on the structural dynamics of PrPC is lacking. From our structural bioinformatics study, we propose that polymorphisms locally modulate the network of residue interactions in the globular C-terminus of the ovine recombinant prion protein while maintaining the overall fold. Although the two variants we examined exhibit a densely connected group of residues that includes both β-sheets, the β2-α2 loop and the N-terminus of α-helix 2, only in the Resistant structure do most residues of α-helix 2 belong to this group. We identify the structural role of Valine136Alanine and Glutamine171Arginine: modulation of residue interaction networks that affect the connectivity between α-helix 2 and α-helix 3. We propose blocking interactions of residue 171 as a potential target for the design of therapeutics to prevent efficient PrPC misfolding. We discuss our results in the context of initial PrPC conversion and extrapolate to recently proposed PrPSc structures.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Patricia Soto
- Department of Physics, Creighton University, Omaha, Nebraska, 68178,Corresponding author: Patricia Soto, Creighton University – Department of Physics, 2500 California Plaza, Omaha, NE 68178, Phone number: 402.280.3361, Fax: 402.280.2140,
| | - India A. Claflin
- Department of Biology, Creighton University, Omaha, Nebraska, 68178
| | | | | | - Jason C. Bartz
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, 68178
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17
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Louka A, Zacco E, Temussi PA, Tartaglia GG, Pastore A. RNA as the stone guest of protein aggregation. Nucleic Acids Res 2020; 48:11880-11889. [PMID: 33068411 PMCID: PMC7708036 DOI: 10.1093/nar/gkaa822] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 09/12/2020] [Accepted: 10/14/2020] [Indexed: 12/13/2022] Open
Abstract
The study of prions as infectious aggregates dates several decades. From its original formulation, the definition of a prion has progressively changed to the point that many aggregation-prone proteins are now considered bona fide prions. RNA molecules, not included in the original 'protein-only hypothesis', are also being recognized as important factors contributing to the 'prion behaviour', that implies the transmissibility of an aberrant fold. In particular, an association has recently emerged between aggregation and the assembly of prion-like proteins in RNA-rich complexes, associated with both physiological and pathological events. Here, we discuss the historical rising of the concept of prion-like domains, their relation to RNA and their role in protein aggregation. As a paradigmatic example, we present the case study of TDP-43, an RNA-binding prion-like protein associated with amyotrophic lateral sclerosis. Through this example, we demonstrate how the current definition of prions has incorporated quite different concepts making the meaning of the term richer and more stimulating. An important message that emerges from our analysis is the dual role of RNA in protein aggregation, making RNA, that has been considered for many years a 'silent presence' or the 'stone guest' of protein aggregation, an important component of the process.
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Affiliation(s)
- Alexandra Louka
- UK Dementia Research Institute at the Maurice Wohl Institute of King's College London, London SE5 9RT, UK
| | - Elsa Zacco
- Center for Human Technologies, Central RNA laboratory, Istituto Italiano di Tecnologia, Genova 16152, Italy
| | - Piero Andrea Temussi
- UK Dementia Research Institute at the Maurice Wohl Institute of King's College London, London SE5 9RT, UK
- University “Federico II’’ Napoli, via Cynthia, Napoli 80100, Italy
| | - Gian Gaetano Tartaglia
- Center for Human Technologies, Central RNA laboratory, Istituto Italiano di Tecnologia, Genova 16152, Italy
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain and ICREA, 23 Passeig Lluıs Companys, Barcelona 08010, Spain
- Charles Darwin department of Biology and Biotechnology, Sapienza University of Rome, Piazzale A. Moro 5, Rome 00185, Italy
| | - Annalisa Pastore
- UK Dementia Research Institute at the Maurice Wohl Institute of King's College London, London SE5 9RT, UK
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18
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The Role of Vesicle Trafficking Defects in the Pathogenesis of Prion and Prion-Like Disorders. Int J Mol Sci 2020; 21:ijms21197016. [PMID: 32977678 PMCID: PMC7582986 DOI: 10.3390/ijms21197016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/15/2020] [Accepted: 09/21/2020] [Indexed: 11/26/2022] Open
Abstract
Prion diseases are fatal and transmissible neurodegenerative diseases in which the cellular form of the prion protein ‘PrPc’, misfolds into an infectious and aggregation prone isoform termed PrPSc, which is the primary component of prions. Many neurodegenerative diseases, like Alzheimer’s disease, Parkinson’s disease, and polyglutamine diseases, such as Huntington’s disease, are considered prion-like disorders because of the common characteristics in the propagation and spreading of misfolded proteins that they share with the prion diseases. Unlike prion diseases, these are non-infectious outside experimental settings. Many vesicular trafficking impairments, which are observed in prion and prion-like disorders, favor the accumulation of the pathogenic amyloid aggregates. In addition, many of the vesicular trafficking impairments that arise in these diseases, turn out to be further aggravating factors. This review offers an insight into the currently known vesicular trafficking defects in these neurodegenerative diseases and their implications on disease progression. These findings suggest that these impaired trafficking pathways may represent similar therapeutic targets in these classes of neurodegenerative disorders.
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19
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Arshad H, Bourkas MEC, Watts JC. The utility of bank voles for studying prion disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 175:179-211. [PMID: 32958232 DOI: 10.1016/bs.pmbts.2020.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The transmission of prions between species is typically an inefficient process due to the species barrier, which represents incompatibility between prion seed and substrate molecules. Bank voles (Myodes glareolus) are an exception to this rule, as they are susceptible to a diverse range of prion strains from many different animal species. In particular, bank voles can be efficiently infected with most types of human prions and have played a critical role in validating variably protease-sensitive prionopathy (VPSPr) and certain forms of Gerstmann-Sträussler-Scheinker (GSS) disease as bona fide prion disorders rather than non-transmissible proteinopathies. The bank vole prion protein (BVPrP) confers a "universal prion acceptor" phenotype when expressed in mice and when used as a substrate for in vitro prion amplification assays, indicating that the unique prion transmission properties of bank voles are mediated by BVPrP. Over-expression of BVPrP in mice can also promote the spontaneous development of prion disease, indicating that BVPrP is intrinsically prone to both spontaneous and template-directed misfolding. Here, we discuss the utility of bank voles and BVPrP for prion research and how they have provided new tools for establishing rapid animal bioassays, modeling spontaneous prion disease, standardizing prion diagnostics, and understanding the molecular basis of the species barrier.
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Affiliation(s)
- Hamza Arshad
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Matthew E C Bourkas
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Joel C Watts
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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20
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Identification of a homology-independent linchpin domain controlling mouse and bank vole prion protein conversion. PLoS Pathog 2020; 16:e1008875. [PMID: 32898162 PMCID: PMC7508373 DOI: 10.1371/journal.ppat.1008875] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 09/22/2020] [Accepted: 08/11/2020] [Indexed: 11/19/2022] Open
Abstract
Prions are unorthodox pathogens that cause fatal neurodegenerative diseases in humans and other mammals. Prion propagation occurs through the self-templating of the pathogenic conformer PrPSc, onto the cell-expressed conformer, PrPC. Here we study the conversion of PrPC to PrPSc using a recombinant mouse PrPSc conformer (mouse protein-only recPrPSc) as a unique tool that can convert bank vole but not mouse PrPC substrates in vitro. Thus, its templating ability is not dependent on sequence homology with the substrate. In the present study, we used chimeric bank vole/mouse PrPC substrates to systematically determine the domain that allows for conversion by Mo protein-only recPrPSc. Our results show that that either the presence of the bank vole amino acid residues E227 and S230 or the absence of the second N-linked glycan are sufficient to allow PrPC substrates to be converted by Mo protein-only recPrPSc and several native infectious prion strains. We propose that residues 227 and 230 and the second glycan are part of a C-terminal domain that acts as a linchpin for bank vole and mouse prion conversion. Prions are unconventional infectious agents that lack nucleic acids such as DNA and RNA, and the mechanism by which prions replicate is not fully understood. It has been established that a central feature of the replication mechanism involves the misfolding of a host protein (PrPC) into an infectious shape termed PrPSc, but it is unclear how this misfolding occurs. Interestingly, it has been observed that a particular animal species, the European bank vole, is unusually susceptible to prion infection and that this near-universal susceptibility is caused by the specific PrPC sequence of this protein. Here we use a powerful and unique biochemical system to determine the specific region of bank vole PrPC that is primarily responsible for its propensity to misfold into PrPSc. This critical region, which is located at the extreme C-terminal end of the protein, appears to act as a linchpin domain that normally stabilizes the shape of PrPC and thereby regulates its misfolding into PrPSc.
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21
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Supattapone S. Cofactor molecules: Essential partners for infectious prions. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 175:53-75. [PMID: 32958241 DOI: 10.1016/bs.pmbts.2020.07.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The protein-only hypothesis predicts that infectious mammalian prions are composed solely of PrPSc, a misfolded conformer of the normal prion protein, PrPC. However, to date, all wild type protein-only PrPSc preparations lack significant levels of prion infectivity. Using a systemic biochemical approach, our laboratory isolated and identified two different endogenous cofactor molecules, RNA (Deleault et al., 2003 [50]; Deleault et al., 2007 [59]) and phosphatidylethanolamine (Deleault et al., 2012 [61]; Deleault et al., 2012 [18]), which facilitate the formation of prions with high levels of specific infectivity, leading us to propose to the alternative hypothesis that cofactor molecules are required to form wild type infectious prions (Deleault et al., 2007 [59]; Deleault et al., 2012 [18]; Geoghegan et al., 2007 [57]). In addition, we found that purified cofactor molecules restrict the strain properties of chemically defined infectious prions (Deleault et al., 2012 [18]), suggesting a "cofactor selection" model in which natural variation in the distribution of strain-specific cofactor molecules in different parts of the brain may be responsible for strain-dependent patterns of neurotropism (Deleault et al., 2012 [18]; Geoghegan et al., 2007 [57]).
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Affiliation(s)
- Surachai Supattapone
- Department of Biochemistry and Cell Biology and Department of Medicine, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States.
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22
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Callender JA, Sevillano AM, Soldau K, Kurt TD, Schumann T, Pizzo DP, Altmeppen H, Glatzel M, Esko JD, Sigurdson CJ. Prion protein post-translational modifications modulate heparan sulfate binding and limit aggregate size in prion disease. Neurobiol Dis 2020; 142:104955. [PMID: 32454127 DOI: 10.1016/j.nbd.2020.104955] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/09/2020] [Accepted: 05/21/2020] [Indexed: 01/05/2023] Open
Abstract
Many aggregation-prone proteins linked to neurodegenerative disease are post-translationally modified during their biogenesis. In vivo pathogenesis studies have suggested that the presence of post-translational modifications can shift the aggregate assembly pathway and profoundly alter the disease phenotype. In prion disease, the N-linked glycans and GPI-anchor on the prion protein (PrP) impair fibril assembly. However, the relevance of the two glycans to aggregate structure and disease progression remains unclear. Here we show that prion-infected knockin mice expressing an additional PrP glycan (tri-glycosylated PrP) develop new plaque-like deposits on neuronal cell membranes, along the subarachnoid space, and periventricularly, suggestive of high prion mobility and transit through the interstitial fluid. These plaque-like deposits were largely non-congophilic and composed of full length, uncleaved PrP, indicating retention of the glycophosphatidylinositol (GPI) anchor. Prion aggregates sedimented in low density fractions following ultracentrifugation, consistent with oligomers, and bound low levels of heparan sulfate (HS) similar to other predominantly GPI-anchored prions. Collectively, these results suggest that highly glycosylated PrP primarily converts as a GPI-anchored glycoform, with low involvement of HS co-factors, limiting PrP assembly mainly to oligomers. Since PrPC is highly glycosylated, these findings may explain the high frequency of diffuse, synaptic, and plaque-like deposits in the brain as well as the rapid conversion commonly observed in human and animal prion disease.
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Affiliation(s)
| | | | - Katrin Soldau
- Departments of Pathology, UC San Diego, La Jolla, CA 92093, USA
| | - Timothy D Kurt
- Departments of Pathology, UC San Diego, La Jolla, CA 92093, USA
| | - Taylor Schumann
- Departments of Pathology, UC San Diego, La Jolla, CA 92093, USA
| | - Donald P Pizzo
- Departments of Pathology, UC San Diego, La Jolla, CA 92093, USA
| | - Hermann Altmeppen
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, 20251, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, 20251, Germany
| | - Jeffrey D Esko
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA 92093, USA
| | - Christina J Sigurdson
- Department of Pathology, Microbiology, and Immunology, UC Davis, Davis, CA 95616, USA; Departments of Medicine, UC San Diego, La Jolla, CA 92093, USA.
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23
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Burke CM, Walsh DJ, Mark KMK, Deleault NR, Nishina KA, Agrimi U, Di Bari MA, Supattapone S. Cofactor and glycosylation preferences for in vitro prion conversion are predominantly determined by strain conformation. PLoS Pathog 2020; 16:e1008495. [PMID: 32294141 PMCID: PMC7185723 DOI: 10.1371/journal.ppat.1008495] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/27/2020] [Accepted: 03/24/2020] [Indexed: 11/18/2022] Open
Abstract
Prion diseases are caused by the misfolding of a host-encoded glycoprotein, PrPC, into a pathogenic conformer, PrPSc. Infectious prions can exist as different strains, composed of unique conformations of PrPSc that generate strain-specific biological traits, including distinctive patterns of PrPSc accumulation throughout the brain. Prion strains from different animal species display different cofactor and PrPC glycoform preferences to propagate efficiently in vitro, but it is unknown whether these molecular preferences are specified by the amino acid sequence of PrPC substrate or by the conformation of PrPSc seed. To distinguish between these two possibilities, we used bank vole PrPC to propagate both hamster or mouse prions (which have distinct cofactor and glycosylation preferences) with a single, common substrate. We performed reconstituted sPMCA reactions using either (1) phospholipid or RNA cofactor molecules, or (2) di- or un-glycosylated bank vole PrPC substrate. We found that prion strains from either species are capable of propagating efficiently using bank vole PrPC substrates when reactions contained the same PrPC glycoform or cofactor molecule preferred by the PrPSc seed in its host species. Thus, we conclude that it is the conformation of the input PrPSc seed, not the amino acid sequence of the PrPC substrate, that primarily determines species-specific cofactor and glycosylation preferences. These results support the hypothesis that strain-specific patterns of prion neurotropism are generated by selection of differentially distributed cofactors molecules and/or PrPC glycoforms during prion replication.
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Affiliation(s)
- Cassandra M. Burke
- Departments of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Daniel J. Walsh
- Departments of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Kenneth M. K. Mark
- Departments of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Nathan R. Deleault
- Departments of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Koren A. Nishina
- Departments of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Umberto Agrimi
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Michele A. Di Bari
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Surachai Supattapone
- Departments of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
- Department of Medicine, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
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24
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Lathe R, Darlix JL. Prion protein PrP nucleic acid binding and mobilization implicates retroelements as the replicative component of transmissible spongiform encephalopathy. Arch Virol 2020; 165:535-556. [PMID: 32025859 PMCID: PMC7024060 DOI: 10.1007/s00705-020-04529-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 12/13/2019] [Indexed: 12/21/2022]
Abstract
The existence of more than 30 strains of transmissible spongiform encephalopathy (TSE) and the paucity of infectivity of purified PrPSc, as well as considerations of PrP structure, are inconsistent with the protein-only (prion) theory of TSE. Nucleic acid is a strong contender as a second component. We juxtapose two key findings: (i) PrP is a nucleic-acid-binding antimicrobial protein that is similar to retroviral Gag proteins in its ability to trigger reverse transcription. (ii) Retroelement mobilization is widely seen in TSE disease. Given further evidence that PrP also mediates nucleic acid transport into and out of the cell, a strong case is to be made that a second element – retroelement nucleic acid – bound to PrP constitutes the second component necessary to explain the multiple strains of TSE.
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Affiliation(s)
- Richard Lathe
- Division of Infection Medicine, University of Edinburgh School of Medicine, Edinburgh, UK. .,Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Moscow, Moscow Region, Russia.
| | - Jean-Luc Darlix
- Faculté de Pharmacie, Centre Nationale de la Recherche Scientifique (CNRS) Laboratory of Bioimaging and Pathologies (Unité Mixte de Recherche 7021), Université de Strasbourg, Illkirch, France.
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Krance SH, Luke R, Shenouda M, Israwi AR, Colpitts SJ, Darwish L, Strauss M, Watts JC. Cellular models for discovering prion disease therapeutics: Progress and challenges. J Neurochem 2020; 153:150-172. [PMID: 31943194 DOI: 10.1111/jnc.14956] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 12/22/2022]
Abstract
Prions, which cause fatal neurodegenerative disorders such as Creutzfeldt-Jakob disease, are misfolded and infectious protein aggregates. Currently, there are no treatments available to halt or even delay the progression of prion disease in the brain. The infectious nature of prions has resulted in animal paradigms that accurately recapitulate all aspects of prion disease, and these have proven to be instrumental for testing the efficacy of candidate therapeutics. Nonetheless, infection of cultured cells with prions provides a much more powerful system for identifying molecules capable of interfering with prion propagation. Certain lines of cultured cells can be chronically infected with various types of mouse prions, and these models have been used to unearth candidate anti-prion drugs that are at least partially efficacious when administered to prion-infected rodents. However, these studies have also revealed that not all types of prions are equal, and that drugs active against mouse prions are not necessarily effective against prions from other species. Despite some recent progress, the number of cellular models available for studying non-mouse prions remains limited. In particular, human prions have proven to be particularly challenging to propagate in cultured cells, which has severely hindered the discovery of drugs for Creutzfeldt-Jakob disease. In this review, we summarize the cellular models that are presently available for discovering and testing drugs capable of blocking the propagation of prions and highlight challenges that remain on the path towards developing therapies for prion disease.
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Affiliation(s)
- Saffire H Krance
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Russell Luke
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Marc Shenouda
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.,Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - Ahmad R Israwi
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Sarah J Colpitts
- Department of Immunology, University of Toronto, Toronto, ON, Canada
| | - Lina Darwish
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Maximilian Strauss
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.,Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - Joel C Watts
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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Holec SA, Block AJ, Bartz JC. The role of prion strain diversity in the development of successful therapeutic treatments. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 175:77-119. [PMID: 32958242 PMCID: PMC8939712 DOI: 10.1016/bs.pmbts.2020.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Prions are a self-propagating misfolded conformation of a cellular protein. Prions are found in several eukaryotic organisms with mammalian prion diseases encompassing a wide range of disorders. The first recognized prion disease, the transmissible spongiform encephalopathies (TSEs), affect several species including humans. Alzheimer's disease, synucleinopathies, and tauopathies share a similar mechanism of self-propagation of the prion form of the disease-specific protein reminiscent of the infection process of TSEs. Strain diversity in prion disease is characterized by differences in the phenotype of disease that is hypothesized to be encoded by strain-specific conformations of the prion form of the disease-specific protein. Prion therapeutics that target the prion form of the disease-specific protein can lead to the emergence of drug-resistant strains of prions, consistent with the hypothesis that prion strains exist as a dynamic mixture of a dominant strain in combination with minor substrains. To overcome this obstacle, therapies that reduce or eliminate the template of conversion are efficacious, may reverse neuropathology, and do not result in the emergence of drug resistance. Recent advancements in preclinical diagnosis of prion infection may allow for a combinational approach that treats the prion form and the precursor protein to effectively treat prion diseases.
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Affiliation(s)
- Sara A.M. Holec
- Institute for Applied Life Sciences and Department of Biology, University of Massachusetts Amherst, Amherst, MA, United States,Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, NE, United States
| | - Alyssa J. Block
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, NE, United States
| | - Jason C. Bartz
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, NE, United States,Corresponding author:
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Caughey B, Kraus A. Transmissibility versus Pathogenicity of Self-Propagating Protein Aggregates. Viruses 2019; 11:E1044. [PMID: 31717531 PMCID: PMC6893620 DOI: 10.3390/v11111044] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 12/22/2022] Open
Abstract
The prion-like spreading and accumulation of specific protein aggregates appear to be central to the pathogenesis of many human diseases, including Alzheimer's and Parkinson's. Accumulating evidence indicates that inoculation of tissue extracts from diseased individuals into suitable experimental animals can in many cases induce the aggregation of the disease-associated protein, as well as related pathological lesions. These findings, together with the history of the prion field, have raised the questions about whether such disease-associated protein aggregates are transmissible between humans by casual or iatrogenic routes, and, if so, do they propagate enough in the new host to cause disease? These practical considerations are important because real, and perhaps even only imagined, risks of human-to-human transmission of diseases such as Alzheimer's and Parkinson's may force costly changes in clinical practice that, in turn, are likely to have unintended consequences. The prion field has taught us that a single protein, PrP, can aggregate into forms that can propagate exponentially in vitro, but range from being innocuous to deadly when injected into experimental animals in ways that depend strongly on factors such as conformational subtleties, routes of inoculation, and host responses. In assessing the hazards posed by various disease-associated, self-propagating protein aggregates, it is imperative to consider both their actual transmissibilities and the pathological consequences of their propagation, if any, in recipient hosts.
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Affiliation(s)
- Byron Caughey
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA
| | - Allison Kraus
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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28
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Eraña H, Charco JM, Di Bari MA, Díaz-Domínguez CM, López-Moreno R, Vidal E, González-Miranda E, Pérez-Castro MA, García-Martínez S, Bravo S, Fernández-Borges N, Geijo M, D’Agostino C, Garrido J, Bian J, König A, Uluca-Yazgi B, Sabate R, Khaychuk V, Vanni I, Telling GC, Heise H, Nonno R, Requena JR, Castilla J. Development of a new largely scalable in vitro prion propagation method for the production of infectious recombinant prions for high resolution structural studies. PLoS Pathog 2019; 15:e1008117. [PMID: 31644574 PMCID: PMC6827918 DOI: 10.1371/journal.ppat.1008117] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 11/04/2019] [Accepted: 10/01/2019] [Indexed: 12/12/2022] Open
Abstract
The resolution of the three-dimensional structure of infectious prions at the atomic level is pivotal to understand the pathobiology of Transmissible Spongiform Encephalopathies (TSE), but has been long hindered due to certain particularities of these proteinaceous pathogens. Difficulties related to their purification from brain homogenates of disease-affected animals were resolved almost a decade ago by the development of in vitro recombinant prion propagation systems giving rise to highly infectious recombinant prions. However, lack of knowledge about the molecular mechanisms of the misfolding event and the complexity of systems such as the Protein Misfolding Cyclic Amplification (PMCA), have limited generating the large amounts of homogeneous recombinant prion preparations required for high-resolution techniques such as solid state Nuclear Magnetic Resonance (ssNMR) imaging. Herein, we present a novel recombinant prion propagation system based on PMCA that substitutes sonication with shaking thereby allowing the production of unprecedented amounts of multi-labeled, infectious recombinant prions. The use of specific cofactors, such as dextran sulfate, limit the structural heterogeneity of the in vitro propagated prions and makes possible, for the first time, the generation of infectious and likely homogeneous samples in sufficient quantities for studies with high-resolution structural techniques as demonstrated by the preliminary ssNMR spectrum presented here. Overall, we consider that this new method named Protein Misfolding Shaking Amplification (PMSA), opens new avenues to finally elucidate the three-dimensional structure of infectious prions.
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Affiliation(s)
- Hasier Eraña
- CIC bioGUNE, Derio (Bizkaia), Spain
- ATLAS Molecular Pharma S. L. Derio (Bizkaia), Spain
| | | | - Michele A. Di Bari
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | | | | | - Enric Vidal
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Barcelona, Spain
| | | | | | | | - Susana Bravo
- Proteomics Lab, IDIS, Santiago de Compostela, Spain
| | | | - Mariví Geijo
- Animal Health Department, NEIKER-Instituto Vasco de Investigación y Desarrollo Agrario, Derio (Bizkaia), Spain
| | - Claudia D’Agostino
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Joseba Garrido
- Animal Health Department, NEIKER-Instituto Vasco de Investigación y Desarrollo Agrario, Derio (Bizkaia), Spain
| | - Jifeng Bian
- Prion Research Center (PRC), Colorado State University, Fort Collins, Colorado, United States of America
| | - Anna König
- Institute of Complex Systems (ICS-6) and Jülich Center for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany
- Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Boran Uluca-Yazgi
- Institute of Complex Systems (ICS-6) and Jülich Center for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany
- Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Raimon Sabate
- Department of Pharmacy and Pharmaceutical Technology and Physical-Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, Spain
| | - Vadim Khaychuk
- Prion Research Center (PRC), Colorado State University, Fort Collins, Colorado, United States of America
| | - Ilaria Vanni
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Glenn C. Telling
- Prion Research Center (PRC), Colorado State University, Fort Collins, Colorado, United States of America
| | - Henrike Heise
- Institute of Complex Systems (ICS-6) and Jülich Center for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany
- Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Romolo Nonno
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Jesús R. Requena
- CIMUS Biomedical Research Institute, University of Santiago de Compostela-IDIS, Spain
| | - Joaquín Castilla
- CIC bioGUNE, Derio (Bizkaia), Spain
- IKERBasque, Basque Foundation for Science, Bilbao (Bizkaia), Spain
- * E-mail:
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