1
|
Do K, Benavente R, Catumbela CSG, Khan U, Kramm C, Soto C, Morales R. Adaptation of the protein misfolding cyclic amplification (PMCA) technique for the screening of anti-prion compounds. FASEB J 2024; 38:e23843. [PMID: 39072789 DOI: 10.1096/fj.202400614r] [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: 03/19/2024] [Revised: 07/05/2024] [Accepted: 07/15/2024] [Indexed: 07/30/2024]
Abstract
Prion diseases result from the misfolding of the physiological prion protein (PrPC) to a pathogenic conformation (PrPSc). Compelling evidence indicates that prevention and/or reduction of PrPSc replication are promising therapeutic strategies against prion diseases. However, the existence of different PrPSc conformations (or strains) associated with disease represents a major problem when identifying anti-prion compounds. Efforts to identify strain-specific anti-prion molecules are limited by the lack of biologically relevant high-throughput screening platforms to interrogate compound libraries. Here, we describe adaptations to the protein misfolding cyclic amplification (PMCA) technology (able to faithfully replicate PrPSc strains) that increase its throughput to facilitate the screening of anti-prion molecules. The optimized PMCA platform includes a reduction in sample and reagents, as well as incubation/sonication cycles required to efficiently replicate and detect rodent-adapted and cervid PrPSc strains. The visualization of PMCA products was performed via dot blots, a method that contributed to reduced processing times. These technical changes allowed us to evaluate small molecules with previously reported anti-prion activity. This proof-of-principle screening was evaluated for six rodent-adapted prion strains. Our data show that these compounds targeted either none, all or some PrPSc strains at variable concentrations, demonstrating that this PMCA system is suitable to test compound libraries for putative anti-prion molecules targeting specific PrPSc strains. Further analyses of a small compound library against deer prions demonstrate the potential of this new PMCA format to identify strain-specific anti-prion molecules. The data presented here demonstrate the use of the PMCA technique in the selection of prion strain-specific anti-prion compounds.
Collapse
Affiliation(s)
- Katherine Do
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Rebeca Benavente
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Celso S G Catumbela
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Uffaf Khan
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Carlos Kramm
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Claudio Soto
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Rodrigo Morales
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, Texas, USA
- Centro Integrativo de Biologia y Quimica Aplicada (CIBQA), Universidad Bernardo O'Higgins, Santiago, Chile
| |
Collapse
|
2
|
Zayed M, Kim YC, Jeong BH. Assessment of the therapeutic potential of Hsp70 activator against prion diseases using in vitro and in vivo models. Front Cell Dev Biol 2024; 12:1411529. [PMID: 39105172 PMCID: PMC11298377 DOI: 10.3389/fcell.2024.1411529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 07/04/2024] [Indexed: 08/07/2024] Open
Abstract
Introduction Prion diseases are deadly neurodegenerative disorders in both animals and humans, causing the destruction of neural tissue and inducing behavioral manifestations. Heat shock proteins (Hsps), act as molecular chaperones by supporting the appropriate folding of proteins and eliminating the misfolded proteins as well as playing a vital role in cell signaling transduction, cell cycle, and apoptosis control. SW02 is a potent activator of Hsp 70 kDa (Hsp70). Methods In the current study, the protective effects of SW02 against prion protein 106-126 (PrP106-126)-induced neurotoxicity in human neuroblastoma cells (SH-SY5Y) were investigated. In addition, the therapeutic effects of SW02 in ME7 scrapie-infected mice were evaluated. Results The results showed that SW02 treatment significantly increased Hsp70 mRNA expression levels and Hsp70 ATPase activity (p < 0.01). SW02 also significantly inhibited cytotoxicity and apoptosis induced by PrP106-126 (p < 0.01) and promoted neurite extension. In vivo, intraperitoneal administration of SW02 did not show a statistically significant difference in survival time (p = 0.16); however, the SW02-treated group exhibited a longer survival time of 223.6 ± 6.0 days compared with the untreated control group survival time of 217.6 ± 5.4 days. In addition, SW02 reduced the PrPSc accumulation in ME7 scrapie-infected mice at 5 months post-injection (p < 0.05). A significant difference was not observed in GFAP expression, an astrocyte marker, between the treated and untreated groups. Conclusion In conclusion, the potential therapeutic role of the Hsp70 activator SW02 was determined in the present study and may be a novel and effective drug to mitigate the pathologies of prion diseases and other neurodegenerative diseases. Further studies using a combination of two pharmacological activators of Hsp70 are required to maximize the effectiveness of each intervention.
Collapse
Affiliation(s)
- Mohammed Zayed
- Korea Zoonosis Research Institute, Jeonbuk National University, Iksan, Republic of Korea
- Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics, Jeonbuk National University, Jeonju, Republic of Korea
- Department of Surgery, College of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Yong-Chan Kim
- Department of Biological Sciences, Andong National University, Andong, Republic of Korea
| | - Byung-Hoon Jeong
- Korea Zoonosis Research Institute, Jeonbuk National University, Iksan, Republic of Korea
- Department of Bioactive Material Sciences, Institute for Molecular Biology and Genetics, Jeonbuk National University, Jeonju, Republic of Korea
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Cheatham AM, Sharma NR, Satpute-Krishnan P. Competition for calnexin binding regulates secretion and turnover of misfolded GPI-anchored proteins. J Cell Biol 2023; 222:e202108160. [PMID: 37702712 PMCID: PMC10499038 DOI: 10.1083/jcb.202108160] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 03/19/2023] [Accepted: 08/10/2023] [Indexed: 09/14/2023] Open
Abstract
In mammalian cells, misfolded glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) are cleared out of the ER to the Golgi via a constitutive and a stress-inducible pathway called RESET. From the Golgi, misfolded GPI-APs transiently access the cell surface prior to rapid internalization for lysosomal degradation. What regulates the release of misfolded GPI-APs for RESET during steady-state conditions and how this release is accelerated during ER stress is unknown. Using mutants of prion protein or CD59 as model misfolded GPI-APs, we demonstrate that inducing calnexin degradation or upregulating calnexin-binding glycoprotein expression triggers the release of misfolded GPI-APs for RESET. Conversely, blocking protein synthesis dramatically inhibits the dissociation of misfolded GPI-APs from calnexin and subsequent turnover. We demonstrate an inverse correlation between newly synthesized calnexin substrates and RESET substrates that coimmunoprecipitate with calnexin. These findings implicate competition by newly synthesized substrates for association with calnexin as a key factor in regulating the release of misfolded GPI-APs from calnexin for turnover via the RESET pathway.
Collapse
Affiliation(s)
- Amber M. Cheatham
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Nishi Raj Sharma
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Prasanna Satpute-Krishnan
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| |
Collapse
|
5
|
Walters RO, Haigh CL. Organoids for modeling prion diseases. Cell Tissue Res 2023; 392:97-111. [PMID: 35088182 PMCID: PMC9329493 DOI: 10.1007/s00441-022-03589-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 01/19/2022] [Indexed: 11/25/2022]
Abstract
Human cerebral organoids are an exciting and novel model system emerging in the field of neurobiology. Cerebral organoids are spheres of self-organizing, neuronal lineage tissue that can be differentiated from human pluripotent stem cells and that present the possibility of on-demand human neuronal cultures that can be used for non-invasively investigating diseases affecting the brain. Compared with existing humanized cell models, they provide a more comprehensive replication of the human cerebral environment. The potential of the human cerebral organoid model is only just beginning to be elucidated, but initial studies have indicated that they could prove to be a valuable model for neurodegenerative diseases such as prion disease. The application of the cerebral organoid model to prion disease, what has been learned so far and the future potential of this model are discussed in this review.
Collapse
Affiliation(s)
- Ryan O Walters
- Prion Cell Biology Unit, Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th Street, Hamilton, MT, 59840, USA
| | - Cathryn L Haigh
- Prion Cell Biology Unit, Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th Street, Hamilton, MT, 59840, USA.
| |
Collapse
|
6
|
Arshad H, Patel Z, Amano G, Li LY, Al-Azzawi ZAM, Supattapone S, Schmitt-Ulms G, Watts JC. A single protective polymorphism in the prion protein blocks cross-species prion replication in cultured cells. J Neurochem 2023; 165:230-245. [PMID: 36511154 DOI: 10.1111/jnc.15739] [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: 10/03/2022] [Revised: 11/22/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022]
Abstract
The bank vole (BV) prion protein (PrP) can function as a universal acceptor of prions. However, the molecular details of BVPrP's promiscuity for replicating a diverse range of prion strains remain obscure. To develop a cultured cell paradigm capable of interrogating the unique properties of BVPrP, we generated monoclonal lines of CAD5 cells lacking endogenous PrP but stably expressing either hamster (Ha), mouse (Mo), or BVPrP (M109 or I109 polymorphic variants) and then challenged them with various strains of mouse or hamster prions. Cells expressing BVPrP were susceptible to both mouse and hamster prions, whereas cells expressing MoPrP or HaPrP could only be infected with species-matched prions. Propagation of mouse and hamster prions in cells expressing BVPrP resulted in strain adaptation in several instances, as evidenced by alterations in conformational stability, glycosylation, susceptibility to anti-prion small molecules, and the inability of BVPrP-adapted mouse prion strains to infect cells expressing MoPrP. Interestingly, cells expressing BVPrP containing the G127V prion gene variant, identified in individuals resistant to kuru, were unable to become infected with prions. Moreover, the G127V polymorphic variant impeded the spontaneous aggregation of recombinant BVPrP. These results demonstrate that BVPrP can facilitate cross-species prion replication in cultured cells and that a single amino acid change can override the prion-permissive nature of BVPrP. This cellular paradigm will be useful for dissecting the molecular features of BVPrP that allow it to function as a universal prion acceptor.
Collapse
Affiliation(s)
- Hamza Arshad
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Zeel Patel
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Genki Amano
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Le Yao Li
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Zaid A M Al-Azzawi
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Surachai Supattapone
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Department of Medicine, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Gerold Schmitt-Ulms
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - 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
| |
Collapse
|
7
|
Molecular insights into the critical role of gallate moiety of green tea catechins in modulating prion fibrillation, cellular internalization, and neuronal toxicity. Int J Biol Macromol 2022; 223:755-765. [PMID: 36368361 DOI: 10.1016/j.ijbiomac.2022.11.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 11/01/2022] [Accepted: 11/06/2022] [Indexed: 11/11/2022]
Abstract
Transmissible spongiform encephalopathies (TSEs) or prion diseases are fatal neurodegenerative diseases with no approved therapeutics. TSE pathology is characterized by abnormal accumulation of amyloidogenic and infectious prion protein conformers (PrPSc) in the central nervous system. Herein, we examined the role of gallate group in green tea catechins in modulating the aggregation of human prion protein (HuPrP) using two green tea constituents i.e., epicatechin 3-gallate (EC3G; with intact gallate ring) and epigallocatechin (EGC; without gallate ring). Molecular docking indicated distinct differences in hydrogen bonding and hydrophobic interactions of EC3G and EGC at the β2-α2 loop of HuPrP. These differences were substantiated by 44-fold higher KD for EC3G as compared to EGC with the former significantly reducing Thioflavin T (ThT) binding aggregates of HuPrP. Conformational alterations in HuPrP aggregates were validated by particle sizing, AFM analysis and A11 and OC conformational antibodies. As compared to EGC, EC3G showed relatively higher reduction in toxicity and cellular internalization of HuPrP oligomers in Neuro-2a cells. Additionally, EC3G also displayed higher fibril disaggregating properties as observed by ThT kinetics and electron microscopy. Our observations were supported by molecular dynamics (MD) simulations that showed markedly reduced α2-α3 and β2-α2 loop mobilities in presence of EC3G that may lead to constriction of HuPrP conformational space with lowered β-sheet conversion. In totality, gallate moiety of catechins play key role in modulating HuPrP aggregation, and toxicity and could be a new structural motif for designing therapeutics against prion diseases and other neurodegenerative disorders.
Collapse
|
8
|
Cellular Prion Protein Role in Cancer Biology: Is It A Potential Therapeutic Target? Biomedicines 2022; 10:biomedicines10112833. [PMID: 36359353 PMCID: PMC9687521 DOI: 10.3390/biomedicines10112833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/04/2022] [Accepted: 09/05/2022] [Indexed: 11/09/2022] Open
Abstract
Cancers are worldwide health concerns, whether they are sporadic or hereditary. The fundamental mechanism that causes somatic or oncogenic mutations and ultimately aids cancer development is still unknown. However, mammalian cells with protein-only somatic inheritance may also contribute to cancerous malignancies. Emerging data from a recent study show that prion-like proteins and prions (PrPC) are crucial entities that have a functional role in developing neurological disorders and cancer. Furthermore, excessive PrPC expression profiling has also been detected in non-neuronal tissues, such as the lymphoid cells, kidney, GIT, lung, muscle, and mammary glands. PrPC expression is strongly linked with the proliferation and metastasis of pancreatic, prostate, colorectal, and breast malignancies. Similarly, experimental investigation presented that the PrPC expression, including the prion protein-coding gene (PRNP) and p53 ag are directly associated with tumorigenicity and metastasis (tumor suppressor gene). The ERK2 (extracellular signal-regulated kinase) pathway also confers a robust metastatic capability for PrPC-induced epithelial to mesenchymal transition. Additionally, prions could alter the epigenetic regulation of genes and overactive the mitogen-activated protein kinase (MAPK) signaling pathway, which promotes the development of cancer in humans. Protein overexpression or suppression caused by a prion and prion-like proteins has also been linked to oncogenesis and metastasis. Meanwhile, additional studies have discovered resistance to therapeutic targets, highlighting the significance of protein expression levels as potential diagnostic indicators and therapeutic targets.
Collapse
|
9
|
Staderini M, Vanni S, Baldeschi AC, Giachin G, Zattoni M, Celauro L, Ferracin C, Bistaffa E, Moda F, Pérez DI, Martínez A, Martín MA, Martín-Cámara O, Cores Á, Bianchini G, Kammerer R, Menéndez JC, Legname G, Bolognesi ML. Bifunctional carbazole derivatives for simultaneous therapy and fluorescence imaging in prion disease murine cell models. Eur J Med Chem 2022; 245:114923. [DOI: 10.1016/j.ejmech.2022.114923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 05/20/2022] [Accepted: 11/08/2022] [Indexed: 11/17/2022]
|
10
|
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.
Collapse
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.
| |
Collapse
|
11
|
Nikolić L, Ferracin C, Legname G. Recent advances in cellular models for discovering prion disease therapeutics. Expert Opin Drug Discov 2022; 17:985-996. [PMID: 35983689 DOI: 10.1080/17460441.2022.2113773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Prion diseases are a group of rare and lethal rapidly progressive neurodegenerative diseases arising due to conversion of the physiological cellular prion protein into its pathological counterparts, denoted as "prions". These agents are resistant to inactivation by standard decontamination procedures and can be transmitted between individuals, consequently driving the irreversible brain damage typical of the diseases. AREAS COVERED Since its infancy, prion research has mainly depended on animal models for untangling the pathogenesis of the disease as well as for the drug development studies. With the advent of prion-infected cell lines, relevant animal models have been complemented by a variety of cell-based models presenting a much faster, ethically acceptable alternative. EXPERT OPINION To date, there are still either no effective prophylactic regimens or therapies for human prion diseases. Therefore, there is an urgent need for more relevant cellular models that best approximate in vivo models. Each cellular model presented and discussed in detail in this review has its own benefits and limitations. Once embarking in a drug screening campaign for the identification of molecules that could interfere with prion conversion and replication, one should carefully consider the ideal cellular model.
Collapse
Affiliation(s)
- Lea Nikolić
- PhD Student in Functional and Structural Genomics, Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy,
| | - Chiara Ferracin
- PhD Student in Functional and Structural Genomics, Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Giuseppe Legname
- D.Phil., Full Professor of Biochemistry, Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| |
Collapse
|
12
|
Colini Baldeschi A, Zattoni M, Vanni S, Nikolic L, Ferracin C, La Sala G, Summa M, Bertorelli R, Bertozzi SM, Giachin G, Carloni P, Bolognesi ML, De Vivo M, Legname G. Innovative Non-PrP-Targeted Drug Strategy Designed to Enhance Prion Clearance. J Med Chem 2022; 65:8998-9010. [PMID: 35771181 PMCID: PMC9289883 DOI: 10.1021/acs.jmedchem.2c00205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Prion diseases are a group of neurodegenerative disorders characterized by the accumulation of misfolded prion protein (called PrPSc). Although conversion of the cellular prion protein (PrPC) to PrPSc is still not completely understood, most of the therapies developed until now are based on blocking this process. Here, we propose a new drug strategy aimed at clearing prions without any direct interaction with neither PrPC nor PrPSc. Starting from the recent discovery of SERPINA3/SerpinA3n upregulation during prion diseases, we have identified a small molecule, named compound 5 (ARN1468), inhibiting the function of these serpins and effectively reducing prion load in chronically infected cells. Although the low bioavailability of this compound does not allow in vivo studies in prion-infected mice, our strategy emerges as a novel and effective approach to the treatment of prion disease.
Collapse
Affiliation(s)
- Arianna Colini Baldeschi
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| | - Marco Zattoni
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| | - Silvia Vanni
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| | - Lea Nikolic
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| | - Chiara Ferracin
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| | - Giuseppina La Sala
- Molecular Modeling & Drug Discovery Lab, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Maria Summa
- Translational Pharmacology, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Rosalia Bertorelli
- Translational Pharmacology, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Sine Mandrup Bertozzi
- Analytical Chemistry Lab, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Gabriele Giachin
- Department of Chemical Sciences (DiSC), University of Padua, Via F. Marzolo 1, 35131 Padova, Italy
| | - Paolo Carloni
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, "Computational Medicine", Forschungszentrum Jülich, 52428 Jülich, Germany.,Institute for Neuroscience and Medicine (INM)-11, "Molecular Neuroscience and Neuroimaging", Forschungszentrum Jülich, 52428 Jülich, Germany.,Department of Physics, RWTH-Aachen University, 52074 Aachen, Germany
| | - Maria Laura Bolognesi
- Department of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy
| | - Marco De Vivo
- Molecular Modeling & Drug Discovery Lab, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Giuseppe Legname
- Laboratory of Prion Biology, Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Via Bonomea 265, 34136 Trieste, Italy
| |
Collapse
|
13
|
Arshad H, Watts JC. Genetically engineered cellular models of prion propagation. Cell Tissue Res 2022; 392:63-80. [PMID: 35581386 DOI: 10.1007/s00441-022-03630-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/26/2022] [Indexed: 11/02/2022]
Abstract
For over three decades, cultured cells have been a useful tool for dissecting the molecular details of prion replication and the identification of candidate therapeutics for prion disease. A major issue limiting the translatability of these studies has been the inability to reliably propagate disease-relevant, non-mouse strains of prions in cells relevant to prion pathogenesis. In recent years, fueled by advances in gene editing technology, it has become possible to propagate prions from hamsters, cervids, and sheep in immortalized cell lines originating from the central nervous system. In particular, the use of CRISPR-Cas9-mediated gene editing to generate versions of prion-permissive cell lines that lack endogenous PrP expression has provided a blank canvas upon which re-expression of PrP leads to species-matched susceptibility to prion infection. When coupled with the ability to propagate prions in cells or organoids derived from stem cells, these next-generation cellular models should provide an ideal paradigm for identifying small molecules and other biological therapeutics capable of interfering with prion replication in animal and human prion disorders. In this review, we summarize recent advances that have widened the spectrum of prion strains that can be propagated in cultured cells and cutting-edge tissue-based models.
Collapse
Affiliation(s)
- Hamza Arshad
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower Rm. 4KD481, 60 Leonard Ave, Toronto, ON, M5T 0S8, Canada.,Department of Biochemistry, University of Toronto, 1 King's College Circle, Medical Sciences Building Rm. 5207, Toronto, ON, M5S 1A8, Canada
| | - Joel C Watts
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower Rm. 4KD481, 60 Leonard Ave, Toronto, ON, M5T 0S8, Canada. .,Department of Biochemistry, University of Toronto, 1 King's College Circle, Medical Sciences Building Rm. 5207, Toronto, ON, M5S 1A8, Canada.
| |
Collapse
|
14
|
Carnosic Acid and Carnosol Display Antioxidant and Anti-Prion Properties in In Vitro and Cell-Free Models of Prion Diseases. Antioxidants (Basel) 2022; 11:antiox11040726. [PMID: 35453411 PMCID: PMC9027925 DOI: 10.3390/antiox11040726] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/01/2022] [Accepted: 04/03/2022] [Indexed: 11/30/2022] Open
Abstract
Prion diseases are transmissible encephalopathies associated with the conversion of the physiological form of the prion protein (PrPC) to the disease-associated (PrPSc). Despite intense research, no therapeutic or prophylactic agent is available. The catechol-type diterpene Carnosic acid (CA) and its metabolite Carnosol (CS) from Rosmarinus officinalis have well-documented anti-oxidative and neuroprotective effects. Since oxidative stress plays an important role in the pathogenesis of prion diseases, we investigated the potential beneficial role of CA and CS in a cellular model of prion diseases (N2a22L cells) and in a cell-free prion amplification assay (RT-QuIC). The antioxidant effects of the compounds were confirmed when N2a22L were incubated with CA or CS. Furthermore, CA and CS reduced the accumulation of the disease-associated form of PrP, detected by Western Blotting, in N2a22L cells. This effect was validated in RT-QuIC assays, indicating that it is not associated with the antioxidant effects of CA and CS. Importantly, cell-free assays revealed that these natural products not only prevent the formation of PrP aggregates but can also disrupt already formed aggregates. Our results indicate that CA and CS have pleiotropic effects against prion diseases and could evolve into useful prophylactic and/or therapeutic agents against prion and other neurodegenerative diseases.
Collapse
|
15
|
Gene-Edited Cell Models to Study Chronic Wasting Disease. Viruses 2022; 14:v14030609. [PMID: 35337016 PMCID: PMC8950194 DOI: 10.3390/v14030609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 11/17/2022] Open
Abstract
Prion diseases are fatal infectious neurodegenerative disorders affecting both humans and animals. They are caused by the misfolded isoform of the cellular prion protein (PrPC), PrPSc, and currently no options exist to prevent or cure prion diseases. Chronic wasting disease (CWD) in deer, elk and other cervids is considered the most contagious prion disease, with extensive shedding of infectivity into the environment. Cell culture models provide a versatile platform for convenient quantification of prions, for studying the molecular and cellular biology of prions, and for performing high-throughput screening of potential therapeutic compounds. Unfortunately, only a very limited number of cell lines are available that facilitate robust and persistent propagation of CWD prions. Gene-editing using programmable nucleases (e.g., CRISPR-Cas9 (CC9)) has proven to be a valuable tool for high precision site-specific gene modification, including gene deletion, insertion, and replacement. CC9-based gene editing was used recently for replacing the PrP gene in mouse and cell culture models, as efficient prion propagation usually requires matching sequence homology between infecting prions and prion protein in the recipient host. As expected, such gene-editing proved to be useful for developing CWD models. Several transgenic mouse models were available that propagate CWD prions effectively, however, mostly fail to reproduce CWD pathogenesis as found in the cervid host, including CWD prion shedding. This is different for the few currently available knock-in mouse models that seem to do so. In this review, we discuss the available in vitro and in vivo models of CWD, and the impact of gene-editing strategies.
Collapse
|
16
|
Muronetz VI, Kudryavtseva SS, Leisi EV, Kurochkina LP, Barinova KV, Schmalhausen EV. Regulation by Different Types of Chaperones of Amyloid Transformation of Proteins Involved in the Development of Neurodegenerative Diseases. Int J Mol Sci 2022; 23:ijms23052747. [PMID: 35269889 PMCID: PMC8910861 DOI: 10.3390/ijms23052747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/21/2022] [Accepted: 02/28/2022] [Indexed: 02/06/2023] Open
Abstract
The review highlights various aspects of the influence of chaperones on amyloid proteins associated with the development of neurodegenerative diseases and includes studies conducted in our laboratory. Different sections of the article are devoted to the role of chaperones in the pathological transformation of alpha-synuclein and the prion protein. Information about the interaction of the chaperonins GroE and TRiC as well as polymer-based artificial chaperones with amyloidogenic proteins is summarized. Particular attention is paid to the effect of blocking chaperones by misfolded and amyloidogenic proteins. It was noted that the accumulation of functionally inactive chaperones blocked by misfolded proteins might cause the formation of amyloid aggregates and prevent the disassembly of fibrillar structures. Moreover, the blocking of chaperones by various forms of amyloid proteins might lead to pathological changes in the vital activity of cells due to the impaired folding of newly synthesized proteins and their subsequent processing. The final section of the article discusses both the little data on the role of gut microbiota in the propagation of synucleinopathies and prion diseases and the possible involvement of the bacterial chaperone GroE in these processes.
Collapse
Affiliation(s)
- Vladimir I. Muronetz
- Belozersky Institute of Physico Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (L.P.K.); (K.V.B.); (E.V.S.)
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119991 Moscow, Russia;
- Correspondence:
| | - Sofia S. Kudryavtseva
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119991 Moscow, Russia;
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia;
| | - Evgeniia V. Leisi
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia;
| | - Lidia P. Kurochkina
- Belozersky Institute of Physico Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (L.P.K.); (K.V.B.); (E.V.S.)
| | - Kseniya V. Barinova
- Belozersky Institute of Physico Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (L.P.K.); (K.V.B.); (E.V.S.)
| | - Elena V. Schmalhausen
- Belozersky Institute of Physico Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; (L.P.K.); (K.V.B.); (E.V.S.)
| |
Collapse
|
17
|
Primary glia cells from bank vole propagate multiple rodent-adapted scrapie prions. Sci Rep 2022; 12:2190. [PMID: 35140295 PMCID: PMC8828835 DOI: 10.1038/s41598-022-06198-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 01/25/2022] [Indexed: 12/14/2022] Open
Abstract
Since the beginning prion research has been largely dependent on animal models for deciphering the disease, drug development or prion detection and quantification. Thereby, ethical as well as cost and labour-saving aspects call for alternatives in vitro. Cell models can replace or at least complement animal studies, but their number is still limited and the application usually restricted to certain strains and host species due to often strong transmission barriers. Bank voles promise to be an exception as they or materials prepared from them are uniquely susceptible to prions from various species in vivo, in vitro and in cell-free applications. Here we present a mainly astrocyte-based primary glia cell assay from bank vole, which is infectible with scrapie strains from bank vole, mouse and hamster. Stable propagation of bank vole-adapted RML, murine 22L and RML, and hamster 263K scrapie is detectable from 20 or 30 days post exposure onwards. Thereby, the infected bank vole glia cells show similar or even faster prion propagation than likewise infected glia cells of the corresponding murine or hamster hosts. We propose that our bank vole glia cell assay could be a versatile tool for studying and comparing multiple prion strains with different species backgrounds combined in one cell assay.
Collapse
|
18
|
Arshad H, Patel Z, Mehrabian M, Bourkas MEC, Al-Azzawi ZAM, Schmitt-Ulms G, Watts JC. The aminoglycoside G418 hinders de novo prion infection in cultured cells. J Biol Chem 2021; 297:101073. [PMID: 34390689 PMCID: PMC8413896 DOI: 10.1016/j.jbc.2021.101073] [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: 03/10/2021] [Revised: 07/23/2021] [Accepted: 08/10/2021] [Indexed: 01/16/2023] Open
Abstract
The study of prions and the discovery of candidate therapeutics for prion disease have been facilitated by the ability of prions to replicate in cultured cells. Paradigms in which prion proteins from different species are expressed in cells with low or no expression of endogenous prion protein (PrP) have expanded the range of prion strains that can be propagated. In these systems, cells stably expressing a PrP of interest are typically generated via coexpression of a selectable marker and treatment with an antibiotic. Here, we report the unexpected discovery that the aminoglycoside G418 (Geneticin) interferes with the ability of stably transfected cultured cells to become infected with prions. In G418-resistant lines of N2a or CAD5 cells, the presence of G418 reduced levels of protease-resistant PrP following challenge with the RML or 22L strains of mouse prions. G418 also interfered with the infection of cells expressing hamster PrP with the 263K strain of hamster prions. Interestingly, G418 had minimal to no effect on protease-resistant PrP levels in cells with established prion infection, arguing that G418 selectively interferes with de novo prion infection. As G418 treatment had no discernible effect on cellular PrP levels or its localization, this suggests that G418 may specifically target prion assemblies or processes involved in the earliest stages of prion infection.
Collapse
Affiliation(s)
- Hamza Arshad
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Zeel Patel
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Mohadeseh Mehrabian
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, 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
| | - Zaid A M Al-Azzawi
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Gerold Schmitt-Ulms
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - 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.
| |
Collapse
|
19
|
Volatile Anesthetic Sevoflurane Precursor 1,1,1,3,3,3-Hexafluoro-2-Propanol (HFIP) Exerts an Anti-Prion Activity in Prion-Infected Culture Cells. Neurochem Res 2021; 46:2056-2065. [PMID: 34043140 PMCID: PMC8254714 DOI: 10.1007/s11064-021-03344-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 04/20/2021] [Accepted: 05/12/2021] [Indexed: 12/22/2022]
Abstract
Prion disease is a neurodegenerative disorder with progressive neurologic symptoms and accelerated cognitive decline. The causative protein of prion disease is the prion protein (PrP), and structural transition of PrP from the normal helix rich form (PrPC) to the abnormal β-sheet rich form (PrPSc) occurs in prion disease. While so far numerous therapeutic agents for prion diseases have been developed, none of them are still useful. A fluorinated alcohol, hexafluoro isopropanol (HFIP), is a precursor to the inhalational anesthetic sevoflurane and its metabolites. HFIP is also known as a robust α-helix inducer and is widely used as a solvent for highly aggregated peptides. Here we show that the α-helix-inducing activity of HFIP caused the conformational transformation of the fibrous structure of PrP into amorphous aggregates in vitro. HFIP added to the ScN2a cell medium, which continuously expresses PrPSc, reduced PrPSc protease resistance after 24-h incubation. It was also clarified that ScN2a cells are more susceptible to HFIP than any of the cells being compared. Based on these findings, HFIP is expected to develop as a therapeutic agent for prion disease.
Collapse
|
20
|
Chen C, Dong X. Therapeutic implications of prion diseases. BIOSAFETY AND HEALTH 2021. [DOI: 10.1016/j.bsheal.2020.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
|
21
|
Pineau H, Sim VL. From Cell Culture to Organoids-Model Systems for Investigating Prion Strain Characteristics. Biomolecules 2021; 11:biom11010106. [PMID: 33466947 PMCID: PMC7830147 DOI: 10.3390/biom11010106] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/05/2021] [Accepted: 01/11/2021] [Indexed: 02/06/2023] Open
Abstract
Prion diseases are the hallmark protein folding neurodegenerative disease. Their transmissible nature has allowed for the development of many different cellular models of disease where prion propagation and sometimes pathology can be induced. This review examines the range of simple cell cultures to more complex neurospheres, organoid, and organotypic slice cultures that have been used to study prion disease pathogenesis and to test therapeutics. We highlight the advantages and disadvantages of each system, giving special consideration to the importance of strains when choosing a model and when interpreting results, as not all systems propagate all strains, and in some cases, the technique used, or treatment applied, can alter the very strain properties being studied.
Collapse
Affiliation(s)
- Hailey Pineau
- Department of Medicine, University of Alberta, Edmonton, AB T6G 2B7, Canada;
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Valerie L. Sim
- Department of Medicine, University of Alberta, Edmonton, AB T6G 2B7, Canada;
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2R3, Canada
- Correspondence:
| |
Collapse
|
22
|
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.
Collapse
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.
| |
Collapse
|