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Block AJ, York TC, Benedict R, Ma J, Bartz JC. Prion protein amino acid sequence influences formation of authentic synthetic PrP Sc. Sci Rep 2023; 13:441. [PMID: 36624174 PMCID: PMC9829857 DOI: 10.1038/s41598-022-26300-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 12/13/2022] [Indexed: 01/11/2023] Open
Abstract
Synthetic prions, generated de novo from minimal, non-infectious components, cause bona fide prion disease in animals. Transmission of synthetic prions to hosts expressing syngeneic PrPC results in extended, variable incubation periods and incomplete attack rates. In contrast, murine synthetic prions (MSP) generated via PMCA with minimal cofactors readily infected mice and hamsters and rapidly adapted to both species. To investigate if hamster synthetic prions (HSP) generated under the same conditions as the MSP are also highly infectious, we inoculated hamsters with HSP generated with either hamster wild type or mutant (ΔG54, ΔG54/M139I, M139I/I205M) recombinant PrP. None of the inoculated hamsters developed clinical signs of prion disease, however, brain homogenate from HSPWT- and HSPΔG54-infected hamsters contained PrPSc, indicating subclinical infection. Serial passage in hamsters resulted in clinical disease at second passage accompanied by changes in incubation period and PrPSc conformational stability between second and third passage. These data suggest the HSP, in contrast to the MSP, are not comprised of PrPSc, and instead generate authentic PrPSc via deformed templating. Differences in infectivity between the MSP and HSP suggest that, under similar generation conditions, the amino acid sequence of PrP influences generation of authentic PrPSc.
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Affiliation(s)
- Alyssa J. Block
- grid.254748.80000 0004 1936 8876Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, 2500 California Plaza, Omaha, NE 68178 USA
| | - Taylor C. York
- grid.254748.80000 0004 1936 8876Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, 2500 California Plaza, Omaha, NE 68178 USA
| | - Romilly Benedict
- grid.17088.360000 0001 2150 1785Department of Plant, Soil, and Microbial Sciences, College of Agriculture and Natural Resources, Michigan State University, East Lansing, MI USA
| | - Jiyan Ma
- grid.251017.00000 0004 0406 2057Van Andel Institute, Center for Neurodegenerative Science, Grand Rapids, MI USA
| | - Jason C. Bartz
- grid.254748.80000 0004 1936 8876Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, 2500 California Plaza, Omaha, NE 68178 USA
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2
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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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3
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Sinha A, Kushwaha R, Molesworth K, Mychko O, Makarava N, Baskakov IV. Phagocytic Activities of Reactive Microglia and Astrocytes Associated with Prion Diseases Are Dysregulated in Opposite Directions. Cells 2021; 10:1728. [PMID: 34359897 PMCID: PMC8304827 DOI: 10.3390/cells10071728] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 01/11/2023] Open
Abstract
Phagocytosis is one of the most important physiological functions of the glia directed at maintaining a healthy, homeostatic environment in the brain. Under a homeostatic environment, the phagocytic activities of astrocytes and microglia are tightly coordinated in time and space. In neurodegenerative diseases, both microglia and astrocytes contribute to neuroinflammation and disease pathogenesis, however, whether their phagocytic activities are up- or downregulated in reactive states is not known. To address this question, this current study isolated microglia and astrocytes from C57BL/6J mice infected with prions and tested their phagocytic activities in live-cell imaging assays that used synaptosomes and myelin debris as substrates. The phagocytic uptake by the reactive microglia was found to be significantly upregulated, whereas that of the reactive astrocytes was strongly downregulated. The up- and downregulation of phagocytosis by the two cell types were observed irrespective of whether disease-associated synaptosomes, normal synaptosomes, or myelin debris were used in the assays, indicating that dysregulations are dictated by cell reactive states, not substrates. Analysis of gene expression confirmed dysregulation of phagocytic functions in both cell types. Immunostaining of animal brains infected with prions revealed that at the terminal stage of disease, neuronal cell bodies were subject to engulfment by reactive microglia. This study suggests that imbalance in the phagocytic activities of the reactive microglia and astrocytes, which are dysregulated in opposite directions, is likely to lead to excessive microglia-mediated neuronal death on the one hand, and the inability of astrocytes to clear cell debris on the other hand, contributing to the neurotoxic effects of glia as a whole.
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Affiliation(s)
- Anshuman Sinha
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.S.); (R.K.); (K.M.); (O.M.); (N.M.)
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Rajesh Kushwaha
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.S.); (R.K.); (K.M.); (O.M.); (N.M.)
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Kara Molesworth
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.S.); (R.K.); (K.M.); (O.M.); (N.M.)
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Olga Mychko
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.S.); (R.K.); (K.M.); (O.M.); (N.M.)
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Natallia Makarava
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.S.); (R.K.); (K.M.); (O.M.); (N.M.)
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Ilia V. Baskakov
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.S.); (R.K.); (K.M.); (O.M.); (N.M.)
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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4
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Abstract
Transformation of astrocytes into reactive states is considered one of the major pathological hallmarks of prion and other neurodegenerative diseases. Recent years witnessed a growing appreciation of the view that reactive astrocytes are intimately involved in chronic neurodegeneration; however, little is known about their role in disease pathogenesis. The current article reviews the progress of the last few years and critically discusses controversial questions of whether reactive astrocytes associated with prion diseases are neurotoxic or neuroprotective and whether bidirectional A1–A2 model is applicable for describing polarization of astrocytes. Moreover, other important topics, including reversibility of a transition to a reactive state, along with the role of microglia and other stimuli in triggering astrocyte activation are reviewed. Defining the role of reactive astrocytes in pathogenesis of neurodegenerative diseases will open unrealized opportunities for developing new therapeutic approaches against prion and other neurodegenerative diseases.
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Affiliation(s)
- Ilia V Baskakov
- Department of Anatomy and Neurobiology, And Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA
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5
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Kushwaha R, Sinha A, Makarava N, Molesworth K, Baskakov IV. Non-cell autonomous astrocyte-mediated neuronal toxicity in prion diseases. Acta Neuropathol Commun 2021; 9:22. [PMID: 33546775 PMCID: PMC7866439 DOI: 10.1186/s40478-021-01123-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/14/2021] [Indexed: 02/08/2023] Open
Abstract
Under normal conditions, astrocytes perform a number of important physiological functions centered around neuronal support and synapse maintenance. In neurodegenerative diseases including Alzheimer’s, Parkinson’s and prion diseases, astrocytes acquire reactive phenotypes, which are sustained throughout the disease progression. It is not known whether in the reactive states associated with prion diseases, astrocytes lose their ability to perform physiological functions and whether the reactive states are neurotoxic or, on the contrary, neuroprotective. The current work addresses these questions by testing the effects of reactive astrocytes isolated from prion-infected C57BL/6J mice on primary neuronal cultures. We found that astrocytes isolated at the clinical stage of the disease exhibited reactive, pro-inflammatory phenotype, which also showed downregulation of genes involved in neurogenic and synaptogenic functions. In astrocyte-neuron co-cultures, astrocytes from prion-infected animals impaired neuronal growth, dendritic spine development and synapse maturation. Toward examining the role of factors secreted by reactive astrocytes, astrocyte-conditioned media was found to have detrimental effects on neuronal viability and synaptogenic functions via impairing synapse integrity, and by reducing spine size and density. Reactive microglia isolated from prion-infected animals were found to induce phenotypic changes in primary astrocytes reminiscent to those observed in prion-infected mice. In particular, astrocytes cultured with reactive microglia-conditioned media displayed hypertrophic morphology and a downregulation of genes involved in neurogenic and synaptogenic functions. In summary, the current study provided experimental support toward the non-cell autonomous mechanisms behind neurotoxicity in prion diseases and demonstrated that the astrocyte reactive phenotype associated with prion diseases is synaptotoxic.
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Makarava N, Chang JCY, Molesworth K, Baskakov IV. Posttranslational modifications define course of prion strain adaptation and disease phenotype. J Clin Invest 2020; 130:4382-4395. [PMID: 32484800 PMCID: PMC7410085 DOI: 10.1172/jci138677] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 05/13/2020] [Indexed: 12/13/2022] Open
Abstract
Posttranslational modifications are a common feature of proteins associated with neurodegenerative diseases including prion protein (PrPC), tau, and α-synuclein. Alternative self-propagating protein states or strains give rise to different disease phenotypes and display strain-specific subsets of posttranslational modifications. The relationships between strain-specific structure, posttranslational modifications, and disease phenotype are poorly understood. We previously reported that among hundreds of PrPC sialoglycoforms expressed by a cell, individual prion strains recruited PrPC molecules selectively, according to the sialylation status of their N-linked glycans. Here we report that transmission of a prion strain to a new host is accompanied by a dramatic shift in the selectivity of recruitment of PrPC sialoglycoforms, giving rise to a self-propagating scrapie isoform (PrPSc) with a unique sialoglycoform signature and disease phenotype. The newly emerged strain has the shortest incubation time to disease and is characterized by colocalization of PrPSc with microglia and a very profound proinflammatory response, features that are linked to a unique sialoglycoform composition of PrPSc. The current work provides experimental support for the hypothesis that strain-specific patterns of PrPSc sialoglycoforms formed as a result of selective recruitment dictate strain-specific disease phenotypes. This work suggests a causative relationship between a strain-specific structure, posttranslational modifications, and disease phenotype.
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Affiliation(s)
- Natallia Makarava
- Center for Biomedical Engineering and Technology and
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Jennifer Chen-Yu Chang
- Center for Biomedical Engineering and Technology and
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Kara Molesworth
- Center for Biomedical Engineering and Technology and
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ilia V. Baskakov
- Center for Biomedical Engineering and Technology and
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Abstract
Chronic neuroinflammation involves reactive microgliosis and astrogliosis, and is regarded as a common pathological hallmark of neurodegenerative diseases including Alzheimer’s, Parkinson’s, ALS and prion diseases. Reactive astrogliosis, routinely observed immunohistochemically as an increase in glial fibrillary acidic protein (GFAP) signal, is a well-documented feature of chronic neuroinflammation associated with neurodegenerative diseases. Recent studies on single-cell transcriptional profiling of a mouse brain revealed that, under normal conditions, several distinct subtypes of astrocytes with regionally specialized distribution exist. However, it remains unclear whether astrocytic response to pro-inflammatory pathological conditions is uniform across whole brain or is region-specific. The current study compares the response of microglia and astrocytes to prions in mice infected with 22L mouse-adapted prion strain. While the intensity of reactive microgliosis correlated well with the extent of PrPSc deposition, reactive astrogliosis displayed a different, region-specific pattern. In particular, the thalamus and stratum oriens of hippocampus, which are both affected by 22L prions, displayed strikingly different response of astrocytes to PrPSc. Astrocytes in stratum oriens of hippocampus responded to accumulation of PrPSc with visible hypertrophy and increased GFAP, while in the thalamus, despite stronger PrPSc signal, the increase of GFAP was milder than in hippocampus, and the change in astrocyte morphology was less pronounced. The current study suggests that astrocyte response to prion infection is heterogeneous and, in part, defined by brain region. Moreover, the current work emphasizes the needs for elucidating region-specific changes in functional states of astrocytes and exploring the impact of these changes to chronic neurodegeneration.
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Affiliation(s)
- Natallia Makarava
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Jennifer Chen-Yu Chang
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Rajesh Kushwaha
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Ilia V Baskakov
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
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8
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Makarava N, Savtchenko R, Lasch P, Beekes M, Baskakov IV. Preserving prion strain identity upon replication of prions in vitro using recombinant prion protein. Acta Neuropathol Commun 2018; 6:92. [PMID: 30208966 PMCID: PMC6134792 DOI: 10.1186/s40478-018-0597-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 09/06/2018] [Indexed: 11/24/2022] Open
Abstract
Last decade witnessed an enormous progress in generating authentic infectious prions or PrPSc in vitro using recombinant prion protein (rPrP). Previous work established that rPrP that lacks posttranslational modification is able to support replication of highly infectious PrPSc with assistance of cofactors of polyanionic nature and/or lipids. Unexpectedly, previous studies also revealed that seeding of rPrP by brain-derived PrPSc gave rise to new prion strains with new disease phenotypes documenting loss of a strain identity upon replication in rPrP substrate. Up to now, it remains unclear whether prion strain identity can be preserved upon replication in rPrP. The current study reports that faithful replication of hamster strain SSLOW could be achieved in vitro using rPrP as a substrate. We found that a mixture of phosphatidylethanolamine (PE) and synthetic nucleic acid polyA was sufficient for stable replication of hamster brain-derived SSLOW PrPSc in serial Protein Misfolding Cyclic Amplification (sPMCA) that uses hamster rPrP as a substrate. The disease phenotype generated in hamsters upon transmission of recombinant PrPSc produced in vitro was strikingly similar to the original SSLOW diseases phenotype with respect to the incubation time to disease, as well as clinical, neuropathological and biochemical features. Infrared microspectroscopy (IR-MSP) indicated that PrPSc produced in animals upon transmission of recombinant PrPSc is structurally similar if not identical to the original SSLOW PrPSc. The current study is the first to demonstrate that rPrP can support replication of brain-derived PrPSc while preserving its strain identity. In addition, the current work is the first to document that successful propagation of a hamster strain could be achieved in vitro using hamster rPrP.
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9
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Bistaffa E, Moda F, Virgilio T, Campagnani I, De Luca CMG, Rossi M, Salzano G, Giaccone G, Tagliavini F, Legname G. Synthetic Prion Selection and Adaptation. Mol Neurobiol 2018; 56:2978-2989. [PMID: 30074230 DOI: 10.1007/s12035-018-1279-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 07/23/2018] [Indexed: 12/31/2022]
Abstract
Prion pathologies are characterized by the conformational conversion of the cellular prion protein (PrPC) into a pathological infectious isoform, known as PrPSc. The latter acquires different abnormal conformations, which are associated with specific pathological phenotypes. Recent evidence suggests that prions adapt their conformation to changes in the context of replication. This phenomenon is known as either prion selection or adaptation, where distinct conformations of PrPSc with higher propensity to propagate in the new environment prevail over the others. Here, we show that a synthetically generated prion isolate, previously subjected to protein misfolding cyclic amplification (PMCA) and then injected in animals, is able to change its biochemical and biophysical properties according to the context of replication. In particular, in second transmission passage in vivo, two different prion isolates were found: one characterized by a predominance of the monoglycosylated band (PrPSc-M) and the other characterized by a predominance of the diglycosylated one (PrPSc-D). Neuropathological, biochemical, and biophysical assays confirmed that these PrPSc possess distinctive characteristics. Finally, PMCA analysis of PrPSc-M and PrPSc-D generated PrPSc (PrPSc-PMCA) whose biophysical properties were different from those of both inocula, suggesting that PMCA selectively amplified a third PrPSc isolate. Taken together, these results indicate that the context of replication plays a pivotal role in either prion selection or adaptation. By exploiting the ability of PMCA to mimic the process of prion replication in vitro, it might be possible to assess how changes in the replication environment influence the phenomenon of prion selection and adaptation.
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Affiliation(s)
- Edoardo Bistaffa
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Fabio Moda
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Tommaso Virgilio
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland
| | - Ilaria Campagnani
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | | | - Martina Rossi
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Giulia Salzano
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Giorgio Giaccone
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Fabrizio Tagliavini
- Unit of Neuropathology and Neurology 5, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Giuseppe Legname
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy.
- ELETTRA Laboratory, Sincrotrone Trieste S.C.p.A, Basovizza, Trieste, Italy.
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10
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Abstract
Transmissible spongiform encephalopathies (TSEs) are caused by an infectious agent that is thought to consist of only misfolded and aggregated prion protein (PrP). Unlike conventional micro-organisms, the agent spreads and propagates by binding to and converting normal host PrP into the abnormal conformer, increasing the infectious titre. Synthetic prions, composed of refolded fibrillar forms of recombinant PrP (rec-PrP) have been generated to address whether PrP aggregates alone are indeed infectious prions. In several reports, the development of TSE disease has been described following inoculation and passage of rec-PrP fibrils in transgenic mice and hamsters. However in studies described here we show that inoculation of rec-PrP fibrils does not always cause clinical TSE disease or increased infectious titre, but can seed the formation of PrP amyloid plaques in PrP-P101L knock-in transgenic mice (101LL). These data are reminiscent of the "prion-like" spread of misfolded protein in other models of neurodegenerative disease following inoculation of transgenic mice with pre-formed amyloid seeds. Protein misfolding, even when the protein is PrP, does not inevitably lead to the development of an infectious TSE disease. It is possible that most in vivo and in vitro produced misfolded PrP is not infectious and that only a specific subpopulation is associated with infectivity and neurotoxicity.
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Affiliation(s)
- Rona M. Barron
- Neurobiology Division, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Easter Bush, UK,Correspondence to: Rona M. Barron; The Roslin Institute, Easter Bush, Midlothian, UK EH25 9RG;
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11
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Abstract
DNA intercalators modulate amyloid assembly of proteins through specific hetero-aromatic interactions diverting them to form amorphous aggregates.
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Affiliation(s)
- Jasdeep Singh
- Kusuma School of Biological Sciences
- Indian Institute of Technology Delhi
- New Delhi
- India
| | - Ankit Srivastava
- Kusuma School of Biological Sciences
- Indian Institute of Technology Delhi
- New Delhi
- India
| | - Pankaj Sharma
- Kusuma School of Biological Sciences
- Indian Institute of Technology Delhi
- New Delhi
- India
| | - Prashant Pradhan
- Kusuma School of Biological Sciences
- Indian Institute of Technology Delhi
- New Delhi
- India
| | - Bishwajit Kundu
- Kusuma School of Biological Sciences
- Indian Institute of Technology Delhi
- New Delhi
- India
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12
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Katorcha E, Daus ML, Gonzalez-Montalban N, Makarava N, Lasch P, Beekes M, Baskakov IV. Reversible off and on switching of prion infectivity via removing and reinstalling prion sialylation. Sci Rep 2016; 6:33119. [PMID: 27609323 PMCID: PMC5017131 DOI: 10.1038/srep33119] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/19/2016] [Indexed: 01/14/2023] Open
Abstract
The innate immune system provides the first line of defense against pathogens. To recognize pathogens, this system detects a number of molecular features that discriminate pathogens from host cells, including terminal sialylation of cell surface glycans. Mammalian cell surfaces, but generally not microbial cell surfaces, have sialylated glycans. Prions or PrPSc are proteinaceous pathogens that lack coding nucleic acids but do possess sialylated glycans. We proposed that sialylation of PrPSc is essential for evading innate immunity and infecting a host. In this study, the sialylation status of PrPSc was reduced by replicating PrPSc in serial Protein Misfolding Cyclic Amplification using sialidase-treated PrPC substrate and then restored to original levels by replication using non-treated substrate. Upon intracerebral administration, all animals that received PrPSc with original or restored sialylation levels were infected, whereas none of the animals that received PrPSc with reduced sialylation were infected. Moreover, brains and spleens of animals from the latter group were completely cleared of prions. The current work established that the ability of prions to infect the host via intracerebral administration depends on PrPSc sialylation status. Remarkably, PrPSc infectivity could be switched off and on in a reversible manner by first removing and then restoring PrPSc sialylation.
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Affiliation(s)
- Elizaveta Katorcha
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, 21201 United States of America.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, 21201 United States of America
| | - Martin L Daus
- Centre for Biological Threats and Special Pathogens, Robert Koch-Institute, 13353 Berlin, Germany
| | - Nuria Gonzalez-Montalban
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, 21201 United States of America.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, 21201 United States of America
| | - Natallia Makarava
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, 21201 United States of America.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, 21201 United States of America
| | - Peter Lasch
- Centre for Biological Threats and Special Pathogens, Robert Koch-Institute, 13353 Berlin, Germany
| | - Michael Beekes
- Centre for Biological Threats and Special Pathogens, Robert Koch-Institute, 13353 Berlin, Germany
| | - Ilia V Baskakov
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, 21201 United States of America.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, 21201 United States of America
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13
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Katorcha E, Srivastava S, Klimova N, Baskakov IV. Sialylation of Glycosylphosphatidylinositol (GPI) Anchors of Mammalian Prions Is Regulated in a Host-, Tissue-, and Cell-specific Manner. J Biol Chem 2016; 291:17009-19. [PMID: 27317661 PMCID: PMC5016106 DOI: 10.1074/jbc.m116.732040] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/09/2016] [Indexed: 01/08/2023] Open
Abstract
Prions or PrP(Sc) are proteinaceous infectious agents that consist of misfolded, self-replicating states of the prion protein or PrP(C) PrP(C) is posttranslationally modified with N-linked glycans and a sialylated glycosylphosphatidylinositol (GPI) anchor. Conformational conversion of PrP(C) gives rise to glycosylated and GPI-anchored PrP(Sc) The question of the sialylation status of GPIs within PrP(Sc) has been controversial. Previous studies that examined scrapie brains reported that both sialo- and asialo-GPIs were present in PrP(Sc), with the majority being asialo-GPIs. In contrast, recent work that employed cultured cells claimed that only PrP(C) with sialylo-GPIs could be recruited into PrP(Sc), whereas PrP(C) with asialo-GPIs inhibited conversion. To resolve this controversy, we analyzed the sialylation status of GPIs within PrP(Sc) generated in the brain, spleen, or cultured N2a or C2C12 myotube cells. We found that recruiting PrP(C) with both sialo- and asialo-GPIs is a common feature of PrP(Sc) The mixtures of sialo- and asialo-GPIs were observed in PrP(Sc) universally regardless of prion strain as well as host, tissue, or type of cells that produced PrP(Sc) Remarkably, the proportion of sialo- versus asialo-GPIs was found to be controlled by host, tissue, and cell type but not prion strain. In summary, this study found no strain-specific preferences for selecting PrP(C) with sialo- versus asialo-GPIs. Instead, this work suggests that the sialylation status of GPIs within PrP(Sc) is regulated in a cell-, tissue-, or host-specific manner and is likely to be determined by the specifics of GPI biosynthesis.
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Affiliation(s)
- Elizaveta Katorcha
- From the Center for Biomedical Engineering and Technology and the Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Saurabh Srivastava
- From the Center for Biomedical Engineering and Technology and the Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Nina Klimova
- From the Center for Biomedical Engineering and Technology and the Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Ilia V Baskakov
- From the Center for Biomedical Engineering and Technology and the Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
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Hu PP, Morales R, Duran-Aniotz C, Moreno-Gonzalez I, Khan U, Soto C. Role of Prion Replication in the Strain-dependent Brain Regional Distribution of Prions. J Biol Chem 2016; 291:12880-12887. [PMID: 27056328 DOI: 10.1074/jbc.m115.681791] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Indexed: 01/30/2023] Open
Abstract
One intriguing feature of prion diseases is their strain variation. Prion strains are differentiated by the clinical consequences they generate in the host, their biochemical properties, and their potential to infect other animal species. The selective targeting of these agents to specific brain structures have been extensively used to characterize prion strains. However, the molecular basis dictating strain-specific neurotropism are still elusive. In this study, isolated brain structures from animals infected with four hamster prion strains (HY, DY, 139H, and SSLOW) were analyzed for their content of protease-resistant PrP(Sc) Our data show that these strains have different profiles of PrP deposition along the brain. These patterns of accumulation, which were independent of regional PrP(C) production, were not reproduced by in vitro replication when different brain regions were used as substrate for the misfolding-amplification reaction. On the contrary, our results show that in vitro replication efficiency depended exclusively on the amount of PrP(C) present in each part of the brain. Our results suggest that the variable regional distribution of PrP(Sc) in distinct strains is not determined by differences on prion formation, but on other factors or cellular pathways. Our findings may contribute to understand the molecular mechanisms of prion pathogenesis and strain diversity.
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Affiliation(s)
- Ping Ping Hu
- From the Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, Houston, Texas 77030,; Innovative Drug Research Centre, Chongqing University, Chongqing 401331, China, and
| | - Rodrigo Morales
- From the Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, Houston, Texas 77030
| | - Claudia Duran-Aniotz
- From the Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, Houston, Texas 77030,; Universidad de los Andes, Facultad de Medicina, Av. San Carlos de Apoquindo 2200, Las Condes, Santiago, Chile
| | - Ines Moreno-Gonzalez
- From the Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, Houston, Texas 77030
| | - Uffaf Khan
- From the Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, Houston, Texas 77030
| | - Claudio Soto
- From the Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, Houston, Texas 77030,; Universidad de los Andes, Facultad de Medicina, Av. San Carlos de Apoquindo 2200, Las Condes, Santiago, Chile.
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Morales R, Hu PP, Duran-Aniotz C, Moda F, Diaz-Espinoza R, Chen B, Bravo-Alegria J, Makarava N, Baskakov IV, Soto C. Strain-dependent profile of misfolded prion protein aggregates. Sci Rep 2016; 6:20526. [PMID: 26877167 DOI: 10.1038/srep20526] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 01/05/2016] [Indexed: 12/21/2022] Open
Abstract
Prions are composed of the misfolded prion protein (PrPSc) organized in a variety of aggregates. An important question in the prion field has been to determine the identity of functional PrPSc aggregates. In this study, we used equilibrium sedimentation in sucrose density gradients to separate PrPSc aggregates from three hamster prion strains (Hyper, Drowsy, SSLOW) subjected to minimal manipulations. We show that PrPSc aggregates distribute in a wide range of arrangements and the relative proportion of each species depends on the prion strain. We observed a direct correlation between the density of the predominant PrPSc aggregates and the incubation periods for the strains studied. The relative presence of PrPSc in fractions of different sucrose densities was indicative of the protein deposits present in the brain as analyzed by histology. Interestingly, no association was found between sensitivity to proteolytic degradation and aggregation profiles. Therefore, the organization of PrP molecules in terms of the density of aggregates generated may determine some of the particular strain properties, whereas others are independent from it. Our findings may contribute to understand the mechanisms of strain variation and the role of PrPSc aggregates in prion-induced neurodegeneration.
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Wang X, McGovern G, Zhang Y, Wang F, Zha L, Jeffrey M, Ma J. Intraperitoneal Infection of Wild-Type Mice with Synthetically Generated Mammalian Prion. PLoS Pathog 2015; 11:e1004958. [PMID: 26136122 PMCID: PMC4489884 DOI: 10.1371/journal.ppat.1004958] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 05/14/2015] [Indexed: 11/23/2022] Open
Abstract
The prion hypothesis postulates that the infectious agent in transmissible spongiform encephalopathies (TSEs) is an unorthodox protein conformation based agent. Recent successes in generating mammalian prions in vitro with bacterially expressed recombinant prion protein provide strong support for the hypothesis. However, whether the pathogenic properties of synthetically generated prion (rec-Prion) recapitulate those of naturally occurring prions remains unresolved. Using end-point titration assay, we showed that the in vitro prepared rec-Prions have infectious titers of around 104 LD50 / μg. In addition, intraperitoneal (i.p.) inoculation of wild-type mice with rec-Prion caused prion disease with an average survival time of 210 – 220 days post inoculation. Detailed pathological analyses revealed that the nature of rec-Prion induced lesions, including spongiform change, disease specific prion protein accumulation (PrP-d) and the PrP-d dissemination amongst lymphoid and peripheral nervous system tissues, the route and mechanisms of neuroinvasion were all typical of classical rodent prions. Our results revealed that, similar to naturally occurring prions, the rec-Prion has a titratable infectivity and is capable of causing prion disease via routes other than direct intra-cerebral challenge. More importantly, our results established that the rec-Prion caused disease is pathogenically and pathologically identical to naturally occurring contagious TSEs, supporting the concept that a conformationally altered protein agent is responsible for the infectivity in TSEs. The transmissible spongiform encephalopathies (TSEs) are a group of infectious neurodegenerative diseases affecting both humans and animals. The prion hypothesis postulates that prions are protein conformation based infectious agents responsible for TSE infectivity. Prions have been synthetically generated in vitro, but it remains unclear whether the properties of synthetically generated prion are the same as those of TSE agents and whether the disease caused by synthetically generated prion is identical to naturally occurring TSEs. In this study, we demonstrated that similar to the classical TSE agents, the synthetically generated prion has a titratable infectivity and is able to cause prion disease in wild-type mice via routes other than direct intra-cerebral inoculation. More importantly, we showed that the synthetically generated prion induced pathological changes, including the dissemination of disease-specific prion protein accumulation and the route and mechanism of neuroinvasion, were all typical of classical TSEs. These results demonstrate the similarity of synthetically generated prion to the infectious agent in TSEs, providing strong evidence supporting the prion hypothesis.
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Affiliation(s)
- Xinhe Wang
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, Michigan, United States of America
- Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio, United States of America
| | - Gillian McGovern
- Animal and Plant Health Agency, Lasswade Laboratory, Pentlands Science Park, Penicuik, Midlothian, Scotland
| | - Yi Zhang
- Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio, United States of America
- Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China
| | - Fei Wang
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, Michigan, United States of America
- Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio, United States of America
| | - Liang Zha
- Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio, United States of America
| | - Martin Jeffrey
- Animal and Plant Health Agency, Lasswade Laboratory, Pentlands Science Park, Penicuik, Midlothian, Scotland
| | - Jiyan Ma
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, Michigan, United States of America
- Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio, United States of America
- Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China
- * E-mail:
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Srivastava S, Baskakov IV. Contrasting Effects of Two Lipid Cofactors of Prion Replication on the Conformation of the Prion Protein. PLoS One 2015; 10:e0130283. [PMID: 26090881 DOI: 10.1371/journal.pone.0130283] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 05/18/2015] [Indexed: 01/03/2023] Open
Abstract
Recent studies introduced two experimental protocols for converting full-length recombinant prion protein (rPrP) purified from E.coli into the infectious prion state (PrPSc) with high infectivity titers. Both protocols employed protein misfolding cyclic amplification (PMCA) for generating PrPScde novo, but used two different lipids, 1-palmitoyl-2-oleolyl-sn-glycero-3-phospho(1’-rac-glycerol) (POPG) or phosphatidylethanolamine (PE), as conversion cofactors. The current study compares the effect of POPG and PE on the physical properties of native, α-helical full-length mouse rPrP under the solvent conditions used for converting rPrP into PrPSc. Surprisingly, the effects of POPG and PE on rPrP physical properties, including its conformation, thermodynamic stability, aggregation state and interaction with a lipid, were found to be remarkably different. PE was shown to have minimal, if any, effects on rPrP thermodynamic stability, cooperativity of unfolding, immediate solvent environment or aggregation state. In fact, little evidence indicates that PE interacts with rPrP directly. In contrast, POPG was found to bind to and induce dramatic changes in rPrP structure, including a loss of α-helical conformation and formation of large lipid-protein aggregates that were resistant to partially denaturing conditions. These results suggest that the mechanisms by which lipids assist conversion of rPrP into PrPSc might be fundamentally different for POPG and PE.
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Nyström S, Hammarström P. Generic amyloidogenicity of mammalian prion proteins from species susceptible and resistant to prions. Sci Rep 2015; 5:10101. [PMID: 25960067 DOI: 10.1038/srep10101] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 03/30/2015] [Indexed: 11/30/2022] Open
Abstract
Prion diseases are lethal, infectious diseases associated with prion protein (PrP) misfolding. A large number of mammals are susceptible to both sporadic and acquired prion diseases. Although PrP is highly conserved and ubiquitously expressed in all mammals, not all species exhibit prion disease. By employing full length recombinant PrP from five known prion susceptible species (human, cattle, cat, mouse and hamster) and two species considered to be prion resistant (pig and dog) the amyloidogenicity of these PrPs has been delineated. All the mammalian PrPs, even from resistant species, were swiftly converted from the native state to amyloid-like structure when subjected to a native condition conversion assay. The PrPs displayed amyloidotypic tinctorial and ultrastructural hallmarks. Self-seeded conversion of the PrPs displayed significantly decreased lag phases demonstrating that nucleation dependent polymerization is a dominating mechanism in the fibrillation process. Fibrils from Aβ1-40, Aβ1-42, Lysozyme, Insulin and Transthyretin did not accelerate conversion of HuPrP whereas fibrils from HuPrP90-231 and HuPrP121-231 as well as full length PrPs of all PrPs efficiently seeded conversion showing specificity of the assay requiring the C-terminal PrP sequence. Our findings have implications for PrP misfolding and could have ramifications in the context of prion resistant species and silent carriers.
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Klimova N, Makarava N, Baskakov IV. The diversity and relationship of prion protein self-replicating states. Virus Res 2014; 207:113-9. [PMID: 25312451 DOI: 10.1016/j.virusres.2014.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/15/2014] [Accepted: 10/01/2014] [Indexed: 10/24/2022]
Abstract
It has become evident that the prion protein (PrP) can form a diverse range of self-replicating structures in addition to bona fide PrP(Sc) or strain-specific PrP(Sc) variants. Some self-replicating states can be only produced in vitro, whereas others can be formed in vivo and in vitro. While transmissible, not all states that replicate in vivo are truly pathogenic. Some of them can replicate silently without causing symptoms or clinical diseases. In the current article we discuss the data on PK-digestion patterns of different self-replicating PrP states in connection with other structural data available to date and assess possible relationships between different self-replicating states. Even though different self-replicating PrP states appear to have significantly different global folding patterns, it seems that the C-terminal region exhibits a cross-β-sheet structure in all self-replicating states, as this region acquires the proteolytically most stable conformation. We also discuss the possibility of the transformation of self-replicating states and triggering of PrP(Sc) formation within the frame of the deformed templating model. The spread of silent self-replicating states is of a particular concern because they can lead to transmissible prion disease. Moreover, examples on how different replication requirements favor different states are discussed. This knowledge can help in designing conditions for selective amplification of a particular PrP state in vitro.
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Affiliation(s)
- Nina Klimova
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 725 W. Lombard St., Baltimore, MD 21201, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 725 W. Lombard St., Baltimore, MD 21201, USA
| | - Natallia Makarava
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 725 W. Lombard St., Baltimore, MD 21201, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 725 W. Lombard St., Baltimore, MD 21201, USA
| | - Ilia V Baskakov
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, 725 W. Lombard St., Baltimore, MD 21201, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 725 W. Lombard St., Baltimore, MD 21201, USA.
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