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Bahadorani M, Nasiri M, Dellinger K, Aravamudhan S, Zadegan R. Engineering Exosomes for Therapeutic Applications: Decoding Biogenesis, Content Modification, and Cargo Loading Strategies. Int J Nanomedicine 2024; 19:7137-7164. [PMID: 39050874 PMCID: PMC11268655 DOI: 10.2147/ijn.s464249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 06/20/2024] [Indexed: 07/27/2024] Open
Abstract
Exosomes emerge from endosomal invagination and range in size from 30 to 200 nm. Exosomes contain diverse proteins, lipids, and nucleic acids, which can indicate the state of various physiological and pathological processes. Studies have revealed the remarkable clinical potential of exosomes in diagnosing and prognosing multiple diseases, including cancer, cardiovascular disorders, and neurodegenerative conditions. Exosomes also have the potential to be engineered and deliver their cargo to a specific target. However, further advancements are imperative to optimize exosomes' diagnostic and therapeutic capabilities for practical implementation in clinical settings. This review highlights exosomes' diagnostic and therapeutic applications, emphasizing their engineering through simple incubation, biological, and click chemistry techniques. Additionally, the loading of therapeutic agents onto exosomes, utilizing passive and active strategies, and exploring hybrid and artificial exosomes are discussed.
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Affiliation(s)
- Mehrnoosh Bahadorani
- Department of Nanoengineering, Joint School of Nanoscience & Nanoengineering, North Carolina Agriculture and Technical State University, Greensboro, NC, USA
| | - Mahboobeh Nasiri
- Department of Nanoengineering, Joint School of Nanoscience & Nanoengineering, North Carolina Agriculture and Technical State University, Greensboro, NC, USA
| | - Kristen Dellinger
- Department of Nanoengineering, Joint School of Nanoscience & Nanoengineering, North Carolina Agriculture and Technical State University, Greensboro, NC, USA
| | - Shyam Aravamudhan
- Department of Nanoengineering, Joint School of Nanoscience & Nanoengineering, North Carolina Agriculture and Technical State University, Greensboro, NC, USA
| | - Reza Zadegan
- Department of Nanoengineering, Joint School of Nanoscience & Nanoengineering, North Carolina Agriculture and Technical State University, Greensboro, NC, USA
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Shirguppe S, Gapinske M, Swami D, Gosstola N, Acharya P, Miskalis A, Joulani D, Szkwarek MG, Bhattacharjee A, Elias G, Stilger M, Winter J, Woods WS, Anand D, Lim CKW, Gaj T, Perez-Pinera P. In vivo CRISPR base editing for treatment of Huntington's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.05.602282. [PMID: 39005280 PMCID: PMC11245100 DOI: 10.1101/2024.07.05.602282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Huntington's disease (HD) is an inherited and ultimately fatal neurodegenerative disorder caused by an expanded polyglutamine-encoding CAG repeat within exon 1 of the huntingtin (HTT) gene, which produces a mutant protein that destroys striatal and cortical neurons. Importantly, a critical event in the pathogenesis of HD is the proteolytic cleavage of the mutant HTT protein by caspase-6, which generates fragments of the N-terminal domain of the protein that form highly toxic aggregates. Given the role that proteolysis of the mutant HTT protein plays in HD, strategies for preventing this process hold potential for treating the disorder. By screening 141 CRISPR base editor variants targeting splice elements in the HTT gene, we identified platforms capable of producing HTT protein isoforms resistant to caspase-6-mediated proteolysis via editing of the splice acceptor sequence for exon 13. When delivered to the striatum of a rodent HD model, these base editors induced efficient exon skipping and decreased the formation of the N-terminal fragments, which in turn reduced HTT protein aggregation and attenuated striatal and cortical atrophy. Collectively, these results illustrate the potential for CRISPR base editing to decrease the toxicity of the mutant HTT protein for HD.
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Herman M, Randall GW, Spiegel JL, Maldonado DJ, Simoes S. Endo-lysosomal dysfunction in neurodegenerative diseases: opinion on current progress and future direction in the use of exosomes as biomarkers. Philos Trans R Soc Lond B Biol Sci 2024; 379:20220387. [PMID: 38368936 PMCID: PMC10874701 DOI: 10.1098/rstb.2022.0387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 11/27/2023] [Indexed: 02/20/2024] Open
Abstract
Over the past two decades, increased research has highlighted the connection between endosomal trafficking defects and neurodegeneration. The endo-lysosomal network is an important, complex cellular system specialized in the transport of proteins, lipids, and other metabolites, essential for cell homeostasis. Disruption of this pathway is linked to a wide range of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease and frontotemporal dementia. Furthermore, there is strong evidence that defects in this pathway create opportunities for diagnostic and therapeutic intervention. In this Opinion piece, we concisely address the role of endo-lysosomal dysfunction in five neurodegenerative diseases and discuss how future research can investigate this intracellular pathway, including extracellular vesicles with a specific focus on exosomes for the identification of novel disease biomarkers. This article is part of a discussion meeting issue 'Understanding the endo-lysosomal network in neurodegeneration'.
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Affiliation(s)
- Mathieu Herman
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Grace W. Randall
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Julia L. Spiegel
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Delphina J. Maldonado
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Sabrina Simoes
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
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Dinamarca MC, Colombo L, Brykczynska U, Grimm A, Fruh I, Hossain I, Gabriel D, Eckert A, Müller M, Pecho-Vrieseling E. Transmission-selective muscle pathology induced by the active propagation of mutant huntingtin across the human neuromuscular synapse. Front Mol Neurosci 2024; 16:1287510. [PMID: 38235149 PMCID: PMC10791992 DOI: 10.3389/fnmol.2023.1287510] [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: 09/01/2023] [Accepted: 11/27/2023] [Indexed: 01/19/2024] Open
Abstract
Neuron-to-neuron transmission of aggregation-prone, misfolded proteins may potentially explain the spatiotemporal accumulation of pathological lesions in the brains of patients with neurodegenerative protein-misfolding diseases (PMDs). However, little is known about protein transmission from the central nervous system to the periphery, or how this propagation contributes to PMD pathology. To deepen our understanding of these processes, we established two functional neuromuscular systems derived from human iPSCs. One was suitable for long-term high-throughput live-cell imaging and the other was adapted to a microfluidic system assuring that connectivity between motor neurons and muscle cells was restricted to the neuromuscular junction. We show that the Huntington's disease (HD)-associated mutant HTT exon 1 protein (mHTTEx1) is transmitted from neurons to muscle cells across the human neuromuscular junction. We found that transmission is an active and dynamic process that starts before aggregate formation and is regulated by synaptic activity. We further found that transmitted mHTTEx1 causes HD-relevant pathology at both molecular and functional levels in human muscle cells, even in the presence of the ubiquitous expression of mHTTEx1. In conclusion, we have uncovered a causal link between mHTTEx1 synaptic transmission and HD pathology, highlighting the therapeutic potential of blocking toxic protein transmission in PMDs.
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Affiliation(s)
- Margarita C. Dinamarca
- Neuronal Development and Degeneration Laboratory, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Laura Colombo
- Neuronal Development and Degeneration Laboratory, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Urszula Brykczynska
- Neuronal Development and Degeneration Laboratory, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Amandine Grimm
- Neurobiology Laboratory for Brain Aging and Mental Health, Transfaculty Research Platform, Molecular and Cognitive Neuroscience, University of Basel, Basel, Switzerland
| | - Isabelle Fruh
- Biomedical Research, Novartis Pharma AG, Novartis Campus, Basel, Switzerland
| | - Imtiaz Hossain
- Biomedical Research, Novartis Pharma AG, Novartis Campus, Basel, Switzerland
| | - Daniela Gabriel
- Biomedical Research, Novartis Pharma AG, Novartis Campus, Basel, Switzerland
| | - Anne Eckert
- Neurobiology Laboratory for Brain Aging and Mental Health, Transfaculty Research Platform, Molecular and Cognitive Neuroscience, University of Basel, Basel, Switzerland
| | - Matthias Müller
- Biomedical Research, Novartis Pharma AG, Novartis Campus, Basel, Switzerland
| | - Eline Pecho-Vrieseling
- Neuronal Development and Degeneration Laboratory, Department of Biomedicine, University of Basel, Basel, Switzerland
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Merighi A, Lossi L. Co-cultures of cerebellar slices from mice with different reelin genetic backgrounds as a model to study cortical lamination. F1000Res 2023; 11:1183. [PMID: 37881513 PMCID: PMC10594056 DOI: 10.12688/f1000research.126787.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/07/2023] [Indexed: 10/27/2023] Open
Abstract
Background: Reelin has fundamental functions in the developing and mature brain. Its absence gives rise to the Reeler phenotype in mice, the first described cerebellar mutation. In homozygous mutants missing the Reelin gene ( reln -/-), neurons are incapable of correctly positioning themselves in layered brain areas such as the cerebral and cerebellar cortices. We here demonstrate that by employing ex vivo cultured cerebellar slices one can reduce the number of animals and use a non-recovery procedure to analyze the effects of Reelin on the migration of Purkinje neurons (PNs). Methods: We generated mouse hybrids (L7-GFP relnF1/) with green fluorescent protein (GFP)-tagged PNs, directly visible under fluorescence microscopy. We then cultured the slices obtained from mice with different reln genotypes and demonstrated that when the slices from reln -/- mutants were co-cultured with those from reln +/- mice, the Reelin produced by the latter induced migration of the PNs to partially rescue the normal layered cortical histology. We have confirmed this observation with Voronoi tessellation to analyze PN dispersion. Results: In images of the co-cultured slices from reln -/- mice, Voronoi polygons were larger than in single-cultured slices of the same genetic background but smaller than those generated from slices of reln +/- animals. The mean roundness factor, area disorder, and roundness factor homogeneity were different when slices from reln -/- mice were cultivated singularly or co-cultivated, supporting mathematically the transition from the clustered organization of the PNs in the absence of Reelin to a layered structure when the protein is supplied ex vivo. Conclusions: Neurobiologists are the primary target users of this 3Rs approach. They should adopt it for the possibility to study and manipulate ex vivo the activity of a brain-secreted or genetically engineered protein (scientific perspective), the potential reduction (up to 20%) of the animals used, and the total avoidance of severe surgery (3Rs perspective).
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Affiliation(s)
- Adalberto Merighi
- Department of Veterinary Sciences, University of Turin, Grugliasco, 10095, Italy
| | - Laura Lossi
- Department of Veterinary Sciences, University of Turin, Grugliasco, 10095, Italy
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Miguez A, Gomis C, Vila C, Monguió-Tortajada M, Fernández-García S, Bombau G, Galofré M, García-Bravo M, Sanders P, Fernández-Medina H, Poquet B, Salado-Manzano C, Roura S, Alberch J, Segovia JC, Allen ND, Borràs FE, Canals JM. Soluble mutant huntingtin drives early human pathogenesis in Huntington's disease. Cell Mol Life Sci 2023; 80:238. [PMID: 37535170 PMCID: PMC10400696 DOI: 10.1007/s00018-023-04882-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 05/19/2023] [Accepted: 07/16/2023] [Indexed: 08/04/2023]
Abstract
Huntington's disease (HD) is an incurable inherited brain disorder characterised by massive degeneration of striatal neurons, which correlates with abnormal accumulation of misfolded mutant huntingtin (mHTT) protein. Research on HD has been hampered by the inability to study early dysfunction and progressive degeneration of human striatal neurons in vivo. To investigate human pathogenesis in a physiologically relevant context, we transplanted human pluripotent stem cell-derived neural progenitor cells (hNPCs) from control and HD patients into the striatum of new-born mice. Most hNPCs differentiated into striatal neurons that projected to their target areas and established synaptic connexions within the host basal ganglia circuitry. Remarkably, HD human striatal neurons first developed soluble forms of mHTT, which primarily targeted endoplasmic reticulum, mitochondria and nuclear membrane to cause structural alterations. Furthermore, HD human cells secreted extracellular vesicles containing mHTT monomers and oligomers, which were internalised by non-mutated mouse striatal neurons triggering cell death. We conclude that interaction of mHTT soluble forms with key cellular organelles initially drives disease progression in HD patients and their transmission through exosomes contributes to spread the disease in a non-cell autonomous manner.
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Affiliation(s)
- Andrés Miguez
- Laboratory of Stem Cells and Regenerative Medicine, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain.
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain.
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain.
- Neurology-Neuroimmunology Department, Multiple Sclerosis Centre of Catalunya (Cemcat), Vall d'Hebron Research Institute (VHIR), Vall d'Hebron University Hospital, Barcelona, Spain.
| | - Cinta Gomis
- Laboratory of Stem Cells and Regenerative Medicine, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain
| | - Cristina Vila
- Laboratory of Stem Cells and Regenerative Medicine, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain
| | - Marta Monguió-Tortajada
- REMAR-IVECAT Group, Germans Trias i Pujol Health Science Research Institute, Can Ruti Campus, Badalona, Spain
| | - Sara Fernández-García
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain
- Laboratory of Pathophysiology of Neurodegenerative Diseases, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
| | - Georgina Bombau
- Laboratory of Stem Cells and Regenerative Medicine, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain
| | - Mireia Galofré
- Laboratory of Stem Cells and Regenerative Medicine, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain
| | - María García-Bravo
- Division of Hematopoietic Innovative Therapies, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Madrid, Spain
| | - Phil Sanders
- Laboratory of Stem Cells and Regenerative Medicine, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain
| | - Helena Fernández-Medina
- Laboratory of Stem Cells and Regenerative Medicine, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain
| | - Blanca Poquet
- Laboratory of Stem Cells and Regenerative Medicine, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain
| | - Cristina Salado-Manzano
- Laboratory of Stem Cells and Regenerative Medicine, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain
| | - Santiago Roura
- ICREC Research Program, Germans Trias i Pujol Health Science Research Institute, Can Ruti Campus, Badalona, Spain
- Faculty of Medicine, University of Vic-Central University of Catalonia (UVic-UCC), Vic, Spain
| | - Jordi Alberch
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain
- Laboratory of Pathophysiology of Neurodegenerative Diseases, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
| | - José Carlos Segovia
- Division of Hematopoietic Innovative Therapies, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Madrid, Spain
| | - Nicholas D Allen
- Brain Repair Group, School of Biosciences, Cardiff University, Cardiff, UK
| | - Francesc E Borràs
- REMAR-IVECAT Group, Germans Trias i Pujol Health Science Research Institute, Can Ruti Campus, Badalona, Spain
- Nephrology Department, Germans Trias i Pujol Universitary Hospital, Badalona, Spain
| | - Josep M Canals
- Laboratory of Stem Cells and Regenerative Medicine, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.
- Creatio, Production and Validation Center of Advanced Therapies, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.
- Institute of Neurosciences, University of Barcelona, Barcelona, Spain.
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain.
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED), Madrid, Spain.
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Bonavita R, Scerra G, Di Martino R, Nuzzo S, Polishchuk E, Di Gennaro M, Williams SV, Caporaso MG, Caiazza C, Polishchuk R, D’Agostino M, Fleming A, Renna M. The HSPB1-p62/SQSTM1 functional complex regulates the unconventional secretion and transcellular spreading of the HD-associated mutant huntingtin protein. Hum Mol Genet 2023; 32:2269-2291. [PMID: 36971475 PMCID: PMC10321397 DOI: 10.1093/hmg/ddad047] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 03/06/2023] [Accepted: 03/23/2023] [Indexed: 07/20/2023] Open
Abstract
Conformational diseases, such as Alzheimer, Parkinson and Huntington diseases, are part of a common class of neurological disorders characterized by the aggregation and progressive accumulation of proteins bearing aberrant conformations. Huntington disease (HD) has autosomal dominant inheritance and is caused by mutations leading to an abnormal expansion in the polyglutamine (polyQ) tract of the huntingtin (HTT) protein, leading to the formation of HTT inclusion bodies in neurons of affected patients. Interestingly, recent experimental evidence is challenging the conventional view by which the disease pathogenesis is solely a consequence of the intracellular accumulation of mutant protein aggregates. These studies reveal that transcellular transfer of mutated huntingtin protein is able to seed oligomers involving even the wild-type (WT) forms of the protein. To date, there is still no successful strategy to treat HD. Here, we describe a novel functional role for the HSPB1-p62/SQSTM1 complex, which acts as a cargo loading platform, allowing the unconventional secretion of mutant HTT by extracellular vesicles. HSPB1 interacts preferentially with polyQ-expanded HTT compared with the WT protein and affects its aggregation. Furthermore, HSPB1 levels correlate with the rate of mutant HTT secretion, which is controlled by the activity of the PI3K/AKT/mTOR signalling pathway. Finally, we show that these HTT-containing vesicular structures are biologically active and able to be internalized by recipient cells, therefore providing an additional mechanism to explain the prion-like spreading properties of mutant HTT. These findings might also have implications for the turn-over of other disease-associated, aggregation-prone proteins.
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Affiliation(s)
| | | | - R Di Martino
- Institute for Endocrinology and Experimental Oncology “G. Salvatore,” National Research Council, 80131 Naples, Italy
- Institute of Biochemistry and Cell Biology, National Research Council, 80131 Naples, Italy
| | - S Nuzzo
- IRCCS SYNLAB SDN, 80143 Naples, Italy
| | - E Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Italy
| | - M Di Gennaro
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples “Federico II”, 80131 Naples, Italy
| | - S V Williams
- Department of Physiology, Development and Neuroscience, University of Cambridge, CB2 3DY Cambridge, UK
| | - M G Caporaso
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples “Federico II”, 80131 Naples, Italy
| | - C Caiazza
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples “Federico II”, 80131 Naples, Italy
| | - R Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Italy
| | - M D’Agostino
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples “Federico II”, 80131 Naples, Italy
| | - A Fleming
- Department of Physiology, Development and Neuroscience, University of Cambridge, CB2 3DY Cambridge, UK
| | - M Renna
- To whom correspondence should be addressed at: Department of Molecular Medicine and Medical Biotechnologies, School of Medicine, University of Naples “Federico II”, Via S. Pansini, 5, Building 19, Corpi Bassi Sud (I floor), 80131 Naples, Italy. Tel: +39 081/7463623, Fax: +39 081-7463205;
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8
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Chaiamarit T, Verhelle A, Chassefeyre R, Shukla N, Novak SW, Andrade LR, Manor U, Encalada SE. Mutant Prion Protein Endoggresomes are Hubs for Local Axonal Organelle-Cytoskeletal Remodeling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.19.533383. [PMID: 36993610 PMCID: PMC10055262 DOI: 10.1101/2023.03.19.533383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Dystrophic axons comprising misfolded mutant prion protein (PrP) aggregates are a characteristic pathological feature in the prionopathies. These aggregates form inside endolysosomes -called endoggresomes-, within swellings that line up the length of axons of degenerating neurons. The pathways impaired by endoggresomes that result in failed axonal and consequently neuronal health, remain undefined. Here, we dissect the local subcellular impairments that occur within individual mutant PrP endoggresome swelling sites in axons. Quantitative high-resolution light and electron microscopy revealed the selective impairment of the acetylated vs tyrosinated microtubule cytoskeleton, while micro-domain image analysis of live organelle dynamics within swelling sites revealed deficits uniquely to the MT-based active transport system that translocates mitochondria and endosomes toward the synapse. Cytoskeletal and defective transport results in the retention of mitochondria, endosomes, and molecular motors at swelling sites, enhancing mitochondria-Rab7 late endosome contacts that induce mitochondrial fission via the activity of Rab7, and render mitochondria dysfunctional. Our findings point to mutant Pr Pendoggresome swelling sites as selective hubs of cytoskeletal deficits and organelle retention that drive the remodeling of organelles along axons. We propose that the dysfunction imparted locally within these axonal micro-domains spreads throughout the axon over time, leading to axonal dysfunction in prionopathies.
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9
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Filippini F, Nola S, Zahraoui A, Roger K, Esmaili M, Sun J, Wojnacki J, Vlieghe A, Bun P, Blanchon S, Rain JC, Taymans JM, Chartier-Harlin MC, Guerrera C, Galli T. Secretion of VGF relies on the interplay between LRRK2 and post-Golgi v-SNAREs. Cell Rep 2023; 42:112221. [PMID: 36905628 DOI: 10.1016/j.celrep.2023.112221] [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: 10/05/2021] [Revised: 01/12/2023] [Accepted: 02/20/2023] [Indexed: 03/12/2023] Open
Abstract
The neuropeptide VGF was recently proposed as a neurodegeneration biomarker. The Parkinson's disease-related protein leucine-rich repeat kinase 2 (LRRK2) regulates endolysosomal dynamics, a process that involves SNARE-mediated membrane fusion and could regulate secretion. Here we investigate potential biochemical and functional links between LRRK2 and v-SNAREs. We find that LRRK2 directly interacts with the v-SNAREs VAMP4 and VAMP7. Secretomics reveals VGF secretory defects in VAMP4 and VAMP7 knockout (KO) neuronal cells. In contrast, VAMP2 KO "regulated secretion-null" and ATG5 KO "autophagy-null" cells release more VGF. VGF is partially associated with extracellular vesicles and LAMP1+ endolysosomes. LRRK2 expression increases VGF perinuclear localization and impairs its secretion. Retention using selective hooks (RUSH) assays show that a pool of VGF traffics through VAMP4+ and VAMP7+ compartments, and LRRK2 expression delays its transport to the cell periphery. Overexpression of LRRK2 or VAMP7-longin domain impairs VGF peripheral localization in primary cultured neurons. Altogether, our results suggest that LRRK2 might regulate VGF secretion via interaction with VAMP4 and VAMP7.
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Affiliation(s)
- Francesca Filippini
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Membrane Traffic in Healthy & Diseased Brain, 75014 Paris, France
| | - Sébastien Nola
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Membrane Traffic in Healthy & Diseased Brain, 75014 Paris, France
| | - Ahmed Zahraoui
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Membrane Traffic in Healthy & Diseased Brain, 75014 Paris, France
| | - Kevin Roger
- Université Paris Cité, Proteomics Platform Necker, Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, 75015 Paris, France
| | - Mansoore Esmaili
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ji Sun
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - José Wojnacki
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Membrane Traffic in Healthy & Diseased Brain, 75014 Paris, France
| | - Anaïs Vlieghe
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Membrane Traffic in Healthy & Diseased Brain, 75014 Paris, France
| | - Philippe Bun
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, NeurImag Imaging Facility, 75014 Paris, France
| | | | | | - Jean-Marc Taymans
- Université de Lille, INSERM, CHU Lille, UMR-S1172, LilNCog - Lille Neuroscience & Cognition, Lille, France
| | | | - Chiara Guerrera
- Université Paris Cité, Proteomics Platform Necker, Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, 75015 Paris, France
| | - Thierry Galli
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Membrane Traffic in Healthy & Diseased Brain, 75014 Paris, France; GHU Paris Psychiatrie & Neurosciences, Paris, France.
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10
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Abjean L, Ben Haim L, Riquelme-Perez M, Gipchtein P, Derbois C, Palomares MA, Petit F, Hérard AS, Gaillard MC, Guillermier M, Gaudin-Guérif M, Aurégan G, Sagar N, Héry C, Dufour N, Robil N, Kabani M, Melki R, De la Grange P, Bemelmans AP, Bonvento G, Deleuze JF, Hantraye P, Flament J, Bonnet E, Brohard S, Olaso R, Brouillet E, Carrillo-de Sauvage MA, Escartin C. Reactive astrocytes promote proteostasis in Huntington's disease through the JAK2-STAT3 pathway. Brain 2023; 146:149-166. [PMID: 35298632 DOI: 10.1093/brain/awac068] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 01/13/2022] [Accepted: 01/24/2022] [Indexed: 01/11/2023] Open
Abstract
Huntington's disease is a fatal neurodegenerative disease characterized by striatal neurodegeneration, aggregation of mutant Huntingtin and the presence of reactive astrocytes. Astrocytes are important partners for neurons and engage in a specific reactive response in Huntington's disease that involves morphological, molecular and functional changes. How reactive astrocytes contribute to Huntington's disease is still an open question, especially because their reactive state is poorly reproduced in experimental mouse models. Here, we show that the JAK2-STAT3 pathway, a central cascade controlling astrocyte reactive response, is activated in the putamen of Huntington's disease patients. Selective activation of this cascade in astrocytes through viral gene transfer reduces the number and size of mutant Huntingtin aggregates in neurons and improves neuronal defects in two complementary mouse models of Huntington's disease. It also reduces striatal atrophy and increases glutamate levels, two central clinical outcomes measured by non-invasive magnetic resonance imaging. Moreover, astrocyte-specific transcriptomic analysis shows that activation of the JAK2-STAT3 pathway in astrocytes coordinates a transcriptional program that increases their intrinsic proteolytic capacity, through the lysosomal and ubiquitin-proteasome degradation systems. This pathway also enhances their production and exosomal release of the co-chaperone DNAJB1, which contributes to mutant Huntingtin clearance in neurons. Together, our results show that the JAK2-STAT3 pathway controls a beneficial proteostasis response in reactive astrocytes in Huntington's disease, which involves bi-directional signalling with neurons to reduce mutant Huntingtin aggregation, eventually improving disease outcomes.
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Affiliation(s)
- Laurene Abjean
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Lucile Ben Haim
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Miriam Riquelme-Perez
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France.,Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, 91057 Evry, France
| | - Pauline Gipchtein
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Céline Derbois
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, 91057 Evry, France
| | - Marie-Ange Palomares
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, 91057 Evry, France
| | - Fanny Petit
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Anne-Sophie Hérard
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Marie-Claude Gaillard
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Martine Guillermier
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Mylène Gaudin-Guérif
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Gwennaëlle Aurégan
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Nisrine Sagar
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Cameron Héry
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Noëlle Dufour
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | | | - Mehdi Kabani
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Ronald Melki
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | | | - Alexis P Bemelmans
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Gilles Bonvento
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Jean-François Deleuze
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, 91057 Evry, France
| | - Philippe Hantraye
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Julien Flament
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Eric Bonnet
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, 91057 Evry, France
| | - Solène Brohard
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, 91057 Evry, France
| | - Robert Olaso
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de Recherche en Génomique Humaine, 91057 Evry, France
| | - Emmanuel Brouillet
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Maria-Angeles Carrillo-de Sauvage
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
| | - Carole Escartin
- Université Paris-Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265 Fontenay-aux-Roses, France
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11
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Asadi F, Dhanvantari S. Misrouting of glucagon and stathmin-2 towards lysosomal system of α-cells in glucagon hypersecretion of diabetes. Islets 2022; 14:40-57. [PMID: 34923907 PMCID: PMC8726656 DOI: 10.1080/19382014.2021.2011550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Glucagon hypersecretion from the pancreatic α-cell is a characteristic sign of diabetes, which exacerbates fasting hyperglycemia. Thus, targeting glucagon secretion from α-cells may be a promising approach for combating hyperglucagonemia. We have recently identified stathmin-2 as an α-cell protein that regulates glucagon secretion by directing glucagon toward the endolysosomal system in αTC1-6 cells. We hypothesized that disruption of Stmn2-mediated trafficking of glucagon to the endolysosomes in diabetes contributes to hyperglucagonemia. In isolated islets from male mice treated with streptozotocin (STZ), glucagon secretion and cellular content were augmented, but cellular Stmn2 levels were reduced (p < .01), as measured by both ELISA and immunofluorescence intensity. Using confocal immunofluorescence microscopy, the colocalization of glucagon and Stmn2 in Lamp2A+ lysosomes was dramatically reduced (p < .001) in islets from diabetic mice, and the colocalization of Stmn2, but not glucagon, with the late endosome marker, Rab7, significantly (p < .01) increased. Further studies were conducted in αTC1-6 cells cultured in media containing high glucose (16.7 mM) for 2 weeks to mimic glucagon hypersecretion of diabetes. Surprisingly, treatment of αTC1-6 cells with the lysosomal inhibitor bafilomycin A1 reduced K+-induced glucagon secretion, suggesting that high glucose may induce glucagon secretion from another lysosomal compartment. Both glucagon and Stmn2 co-localized with Lamp1, which marks secretory lysosomes, in cells cultured in high glucose. We propose that, in addition to enhanced trafficking and secretion through the regulated secretory pathway, the hyperglucagonemia of diabetes may also be due to re-routing of glucagon from the degradative Lamp2A+ lysosome toward the secretory Lamp1+ lysosome.
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Affiliation(s)
- Farzad Asadi
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Savita Dhanvantari
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
- Department of Medical Biophysics, Western University, London, ON, Canada
- Metabolism & Diabetes and Imaging Programs, Lawson Health Research Institute, London, ON, Canada
- CONTACT Savita Dhanvantari Lawson Health Research Institute, PO Box 5777, Stn B, London, ONN6A 4V2, Canada
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12
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Brás IC, Khani MH, Vasili E, Möbius W, Riedel D, Parfentev I, Gerhardt E, Fahlbusch C, Urlaub H, Zweckstetter M, Gollisch T, Outeiro TF. Molecular Mechanisms Mediating the Transfer of Disease-Associated Proteins and Effects on Neuronal Activity. JOURNAL OF PARKINSON'S DISEASE 2022; 12:2397-2422. [PMID: 36278361 DOI: 10.3233/jpd-223516] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Various cellular pathways have been implicated in the transfer of disease-related proteins between cells, contributing to disease progression and neurodegeneration. However, the overall effects of protein transfer are still unclear. OBJECTIVE Here, we performed a systematic comparison of basic molecular mechanisms involved in the release of alpha-synuclein, Tau, and huntingtin, and evaluated functional effects upon internalization by receiving cells. METHODS Evaluation of protein release to the extracellular space in a free form and in extracellular vesicles using an optimized ultracentrifugation protocol. The extracellular effects of the proteins and extracellular vesicles in primary neuronal cultures were assessed using multi-channel electrophysiological recordings combined with a customized spike sorting framework. RESULTS We demonstrate cells differentially release free-forms of each protein to the extracellular space. Importantly, neuronal activity is distinctly modulated upon protein internalization in primary cortical cultures. In addition, these disease-related proteins also occur in extracellular vesicles, and are enriched in ectosomes. Internalization of ectosomes and exosomes by primary microglial or astrocytic cells elicits the production of pro-inflammatory cytokines, and modifies spontaneous electrical activity in neurons. OBJECTIVE Overall, our study demonstrates that released proteins can have detrimental effects for surrounding cells, and suggests protein release pathways may be exploited as therapeutic targets in different neurodegenerative diseases.
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Affiliation(s)
- Inês C Brás
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Mohammad H Khani
- Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
| | - Eftychia Vasili
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute for Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Dietmar Riedel
- Laboratory of Electron Microscopy, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Iwan Parfentev
- Research Group Bioanalytical Mass Spectrometry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ellen Gerhardt
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Christiane Fahlbusch
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Henning Urlaub
- Research Group Bioanalytical Mass Spectrometry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.,Bioanalytics, Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany.,Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Tim Gollisch
- Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
| | - Tiago F Outeiro
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany.,Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.,Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, United Kingdom.,Scientific Employee with an Honorary Contract at German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
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13
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Neueder A, Kojer K, Hering T, Lavery DJ, Chen J, Birth N, Hallitsch J, Trautmann S, Parker J, Flower M, Sethi H, Haider S, Lee JM, Tabrizi SJ, Orth M. Abnormal molecular signatures of inflammation, energy metabolism, and vesicle biology in human Huntington disease peripheral tissues. Genome Biol 2022; 23:189. [PMID: 36071529 PMCID: PMC9450392 DOI: 10.1186/s13059-022-02752-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 08/18/2022] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND A major challenge in neurodegenerative diseases concerns identifying biological disease signatures that track with disease progression or respond to an intervention. Several clinical trials in Huntington disease (HD), an inherited, progressive neurodegenerative disease, are currently ongoing. Therefore, we examine whether peripheral tissues can serve as a source of readily accessible biological signatures at the RNA and protein level in HD patients. RESULTS We generate large, high-quality human datasets from skeletal muscle, skin and adipose tissue to probe molecular changes in human premanifest and early manifest HD patients-those most likely involved in clinical trials. The analysis of the transcriptomics and proteomics data shows robust, stage-dependent dysregulation. Gene ontology analysis confirms the involvement of inflammation and energy metabolism in peripheral HD pathogenesis. Furthermore, we observe changes in the homeostasis of extracellular vesicles, where we find consistent changes of genes and proteins involved in this process. In-depth single nucleotide polymorphism data across the HTT gene are derived from the generated primary cell lines. CONCLUSIONS Our 'omics data document the involvement of inflammation, energy metabolism, and extracellular vesicle homeostasis. This demonstrates the potential to identify biological signatures from peripheral tissues in HD suitable as biomarkers in clinical trials. The generated data, complemented by the primary cell lines established from peripheral tissues, and a large panel of iPSC lines that can serve as human models of HD are a valuable and unique resource to advance the current understanding of molecular mechanisms driving HD pathogenesis.
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Affiliation(s)
- Andreas Neueder
- Department of Neurology, Ulm University, 89081, Ulm, Germany
| | - Kerstin Kojer
- Department of Neurology, Ulm University, 89081, Ulm, Germany
| | - Tanja Hering
- Department of Neurology, Ulm University, 89081, Ulm, Germany
| | - Daniel J Lavery
- CHDI Foundation, Princeton, NJ, 08540, USA
- Loulou Foundation, Orphan Disease Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jian Chen
- CHDI Foundation, Princeton, NJ, 08540, USA
| | - Nathalie Birth
- Department of Neurology, Ulm University, 89081, Ulm, Germany
| | | | - Sonja Trautmann
- Department of Neurology, Ulm University, 89081, Ulm, Germany
| | - Jennifer Parker
- UCL Huntington's Disease Centre, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Michael Flower
- UCL Huntington's Disease Centre, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Huma Sethi
- UCL Huntington's Disease Centre, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Salman Haider
- UCL Huntington's Disease Centre, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Jong-Min Lee
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
| | - Sarah J Tabrizi
- UCL Huntington's Disease Centre, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Michael Orth
- Department of Neurology, Ulm University, 89081, Ulm, Germany.
- Swiss Huntington Centre, Neurozentrum, Siloah AG, Worbstr. 312, 3073, Gümligen, Switzerland.
- University Hospital of Old Age Psychiatry and Psychotherapy, Bern University, Bern, Switzerland.
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14
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Donnelly KM, Coleman CM, Fuller ML, Reed VL, Smerina D, Tomlinson DS, Pearce MMP. Hunting for the cause: Evidence for prion-like mechanisms in Huntington’s disease. Front Neurosci 2022; 16:946822. [PMID: 36090278 PMCID: PMC9448931 DOI: 10.3389/fnins.2022.946822] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 07/28/2022] [Indexed: 11/23/2022] Open
Abstract
The hypothesis that pathogenic protein aggregates associated with neurodegenerative diseases spread from cell-to-cell in the brain in a manner akin to infectious prions has gained substantial momentum due to an explosion of research in the past 10–15 years. Here, we review current evidence supporting the existence of prion-like mechanisms in Huntington’s disease (HD), an autosomal dominant neurodegenerative disease caused by expansion of a CAG repeat tract in exon 1 of the huntingtin (HTT) gene. We summarize information gained from human studies and in vivo and in vitro models of HD that strongly support prion-like features of the mutant HTT (mHTT) protein, including potential involvement of molecular features of mHTT seeds, synaptic structures and connectivity, endocytic and exocytic mechanisms, tunneling nanotubes, and nonneuronal cells in mHTT propagation in the brain. We discuss mechanisms by which mHTT aggregate spreading and neurotoxicity could be causally linked and the potential benefits of targeting prion-like mechanisms in the search for new disease-modifying therapies for HD and other fatal neurodegenerative diseases.
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Affiliation(s)
- Kirby M. Donnelly
- Department of Biological Sciences, University of the Sciences, Philadelphia, PA, United States
| | - Cevannah M. Coleman
- Department of Biological Sciences, University of the Sciences, Philadelphia, PA, United States
| | - Madison L. Fuller
- Department of Biological Sciences, University of the Sciences, Philadelphia, PA, United States
| | - Victoria L. Reed
- Department of Biological Sciences, University of the Sciences, Philadelphia, PA, United States
| | - Dayna Smerina
- Department of Biological Sciences, University of the Sciences, Philadelphia, PA, United States
| | - David S. Tomlinson
- Department of Biological Sciences, University of the Sciences, Philadelphia, PA, United States
| | - Margaret M. Panning Pearce
- Department of Biological Sciences, University of the Sciences, Philadelphia, PA, United States
- Department of Biology, Saint Joseph’s University, Philadelphia, PA, United States
- *Correspondence: Margaret M. Panning Pearce,
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15
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Ahat E, Bui S, Zhang J, da Veiga Leprevost F, Sharkey L, Reid W, Nesvizhskii AI, Paulson HL, Wang Y. GRASP55 regulates the unconventional secretion and aggregation of mutant huntingtin. J Biol Chem 2022; 298:102219. [PMID: 35780830 PMCID: PMC9352920 DOI: 10.1016/j.jbc.2022.102219] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 06/19/2022] [Accepted: 06/20/2022] [Indexed: 11/25/2022] Open
Abstract
Recent studies demonstrated that the Golgi reassembly stacking proteins (GRASPs), especially GRASP55, regulate Golgi-independent unconventional secretion of certain cytosolic and transmembrane cargoes; however, the underlying mechanism remains unknown. Here, we surveyed several neurodegenerative disease-related proteins, including mutant huntingtin (Htt-Q74), superoxide dismutase 1 (SOD1), tau, and TAR DNA-binding protein 43 (TDP-43), for unconventional secretion; our results show that Htt-Q74 is most robustly secreted in a GRASP55-dependent manner. Using Htt-Q74 as a model system, we demonstrate that unconventional secretion of Htt is GRASP55 and autophagy dependent and is enhanced under stress conditions such as starvation and endoplasmic reticulum stress. Mechanistically, we show that GRASP55 facilitates Htt secretion by tethering autophagosomes to lysosomes to promote autophagosome maturation and subsequent lysosome secretion and by stabilizing p23/TMED10, a channel for translocation of cytoplasmic proteins into the lumen of the endoplasmic reticulum-Golgi intermediate compartment. Moreover, we found that GRASP55 levels are upregulated by various stresses to facilitate unconventional secretion, whereas inhibition of Htt-Q74 secretion by GRASP55 KO enhances Htt aggregation and toxicity. Finally, comprehensive secretomic analysis identified novel cytosolic cargoes secreted by the same unconventional pathway, including transgelin (TAGLN), multifunctional protein ADE2 (PAICS), and peroxiredoxin-1 (PRDX1). In conclusion, this study defines the pathway of GRASP55-mediated unconventional protein secretion and provides important insights into the progression of Huntington's disease.
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Affiliation(s)
- Erpan Ahat
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Sarah Bui
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jianchao Zhang
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Lisa Sharkey
- Department of Neurology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Whitney Reid
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Alexey I. Nesvizhskii
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA,Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA
| | - Henry L. Paulson
- Department of Neurology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Yanzhuang Wang
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA; Department of Neurology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA.
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16
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Vats S, Galli T. Role of SNAREs in Unconventional Secretion—Focus on the VAMP7-Dependent Secretion. Front Cell Dev Biol 2022; 10:884020. [PMID: 35784483 PMCID: PMC9244844 DOI: 10.3389/fcell.2022.884020] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 05/27/2022] [Indexed: 11/28/2022] Open
Abstract
Intracellular membrane protein trafficking is crucial for both normal cellular physiology and cell-cell communication. The conventional secretory route follows transport from the Endoplasmic reticulum (ER) to the plasma membrane via the Golgi apparatus. Alternative modes of secretion which can bypass the need for passage through the Golgi apparatus have been collectively termed as Unconventional protein secretion (UPS). UPS can comprise of cargo without a signal peptide or proteins which escape the Golgi in spite of entering the ER. UPS has been classified further depending on the mode of transport. Type I and Type II unconventional secretion are non-vesicular and non-SNARE protein dependent whereas Type III and Type IV dependent on vesicles and on SNARE proteins. In this review, we focus on the Type III UPS which involves the import of cytoplasmic proteins in membrane carriers of autophagosomal/endosomal origin and release in the extracellular space following SNARE-dependent intracellular membrane fusion. We discuss the role of vesicular SNAREs with a strong focus on VAMP7, a vesicular SNARE involved in exosome, lysosome and autophagy mediated secretion. We further extend our discussion to the role of unconventional secretion in health and disease with emphasis on cancer and neurodegeneration.
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Affiliation(s)
- Somya Vats
- Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Membrane Traffic in Healthy and Diseased Brain, Université Paris Cité, Paris, France
| | - Thierry Galli
- Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Membrane Traffic in Healthy and Diseased Brain, Université Paris Cité, Paris, France
- GHU PARIS Psychiatrie & Neurosciences, Paris, France
- *Correspondence: Thierry Galli,
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17
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Filaquier A, Marin P, Parmentier ML, Villeneuve J. Roads and hubs of unconventional protein secretion. Curr Opin Cell Biol 2022; 75:102072. [PMID: 35305454 DOI: 10.1016/j.ceb.2022.02.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/07/2022] [Accepted: 02/14/2022] [Indexed: 12/11/2022]
Abstract
In eukaryotes, there is now compelling evidence that in addition to the conventional endoplasmic reticulum-Golgi secretory pathway, there are additional routes for the export of cytoplasmic proteins with a critical role in numerous physio-pathological conditions. These alternative secretory pathways or unconventional protein secretion (UPS) start now to be molecularly dissected, and while UPS landscape appears to be governed by a striking diversity and heterogeneity of mechanisms, common principles are emerging. We review here the role of key molecular determinants as well as the role of central hubs for UPS, highlighting the plasticity and dynamic properties of membrane-bound compartments. We also describe recent findings that position UPS as an integral component of adaptive responses to cope with particular cellular needs and stresses.
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Affiliation(s)
- Aurore Filaquier
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Philippe Marin
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Marie-Laure Parmentier
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Julien Villeneuve
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France.
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18
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Yoshida S, Hasegawa T. Deciphering the prion-like behavior of pathogenic protein aggregates in neurodegenerative diseases. Neurochem Int 2022; 155:105307. [PMID: 35181393 DOI: 10.1016/j.neuint.2022.105307] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/12/2022] [Accepted: 02/13/2022] [Indexed: 12/12/2022]
Abstract
Neurodegenerative diseases are hitherto classified based on their core clinical features, the anatomical distribution of neurodegeneration, and the cell populations mainly affected. On the other hand, the wealth of neuropathological, genetic, molecular and biochemical studies have identified the existence of distinct insoluble protein aggregates in the affected brain regions. These findings have spread the use of a collective term, proteinopathy, for neurodegenerative disorders with particular type of structurally altered protein accumulation. Particularly, a recent breakthrough in this field came with the discovery that these protein aggregates can transfer from one cell to another, thereby converting normal proteins to potentially toxic, misfolded species in a prion-like manner. In this review, we focus specifically on the molecular and cellular basis that underlies the seeding activity and transcellular spreading phenomenon of neurodegeneration-related protein aggregates, and discuss how these events contribute to the disease progression.
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Affiliation(s)
- Shun Yoshida
- Division of Neurology, Department of Neuroscience & Sensory Organs, Tohoku University Graduate School of Medicine, Sendai, Miyagi, 9808574, Japan; Department of Neurology, National Hospital Organization Yonezawa Hospital, Yonezawa, Yamagata, 992-1202, Japan
| | - Takafumi Hasegawa
- Division of Neurology, Department of Neuroscience & Sensory Organs, Tohoku University Graduate School of Medicine, Sendai, Miyagi, 9808574, Japan.
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19
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Alpaugh M, Denis HL, Cicchetti F. Prion-like properties of the mutant huntingtin protein in living organisms: the evidence and the relevance. Mol Psychiatry 2022; 27:269-280. [PMID: 34711942 DOI: 10.1038/s41380-021-01350-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
If theories postulating that pathological proteins associated with neurodegenerative disorders behave similarly to prions were initially viewed with reluctance, it is now well-accepted that this occurs in several disease contexts. Notably, it has been reported that protein misfolding and subsequent prion-like properties can actively participate in neurodegenerative disorders. While this has been demonstrated in multiple cellular and animal model systems related to Alzheimer's and Parkinson's diseases, the prion-like properties of the mutant huntingtin protein (mHTT), associated with Huntington's disease (HD), have only recently been considered to play a role in this pathology, a concept our research group has contributed to extensively. In this review, we summarize the last few years of in vivo research in the field and speculate on the relationship between prion-like events and human HD. By interpreting observations primarily collected in in vivo models, our discussion will aim to discriminate which experimental factors contribute to the most efficient types of prion-like activities of mHTT and which routes of propagation may be more relevant to the human condition. A look back at nearly a decade of experimentation will inform future research and whether therapeutic strategies may emerge from this new knowledge.
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Affiliation(s)
- Melanie Alpaugh
- Centre de Recherche du CHU de Québec - Université Laval, Axe Neurosciences, Québec, QC, G1V 4G2, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Hélèna L Denis
- Centre de Recherche du CHU de Québec - Université Laval, Axe Neurosciences, Québec, QC, G1V 4G2, Canada.,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Francesca Cicchetti
- Centre de Recherche du CHU de Québec - Université Laval, Axe Neurosciences, Québec, QC, G1V 4G2, Canada. .,Département de Psychiatrie & Neurosciences, Université Laval, Québec, QC, G1V 0A6, Canada.
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20
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Jarosińska OD, Rüdiger SGD. Molecular Strategies to Target Protein Aggregation in Huntington's Disease. Front Mol Biosci 2021; 8:769184. [PMID: 34869596 PMCID: PMC8636123 DOI: 10.3389/fmolb.2021.769184] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/18/2021] [Indexed: 11/30/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by the aggregation of the mutant huntingtin (mHTT) protein in nerve cells. mHTT self-aggregates to form soluble oligomers and insoluble fibrils, which interfere in a number of key cellular functions. This leads to cell quiescence and ultimately cell death. There are currently still no treatments available for HD, but approaches targeting the HTT levels offer systematic, mechanism-driven routes towards curing HD and other neurodegenerative diseases. This review summarizes the current state of knowledge of the mRNA targeting approaches such as antisense oligonucleotides and RNAi system; and the novel methods targeting mHTT and aggregates for degradation via the ubiquitin proteasome or the autophagy-lysosomal systems. These methods include the proteolysis-targeting chimera, Trim-Away, autophagosome-tethering compound, autophagy-targeting chimera, lysosome-targeting chimera and approach targeting mHTT for chaperone-mediated autophagy. These molecular strategies provide a knowledge-based approach to target HD and other neurodegenerative diseases at the origin.
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Affiliation(s)
- Olga D. Jarosińska
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands
- Science for Life, Utrecht University, Utrecht, Netherlands
| | - Stefan G. D. Rüdiger
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands
- Science for Life, Utrecht University, Utrecht, Netherlands
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21
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Chongtham A, Isas JM, Pandey NK, Rawat A, Yoo JH, Mastro T, Kennedy MB, Langen R, Khoshnan A. Amplification of neurotoxic HTTex1 assemblies in human neurons. Neurobiol Dis 2021; 159:105517. [PMID: 34563643 DOI: 10.1016/j.nbd.2021.105517] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/24/2021] [Accepted: 09/21/2021] [Indexed: 11/25/2022] Open
Abstract
Huntington's disease (HD) is a genetically inherited neurodegenerative disorder caused by expansion of a polyglutamine (polyQ) repeat in the exon-1 of huntingtin protein (HTT). The expanded polyQ enhances the amyloidogenic propensity of HTT exon 1 (HTTex1), which forms a heterogeneous mixture of assemblies with a broad neurotoxicity spectrum. While predominantly intracellular, monomeric and aggregated mutant HTT species are also present in the cerebrospinal fluids of HD patients, however, their biological properties are not well understood. To explore the role of extracellular mutant HTT in aggregation and toxicity, we investigated the uptake and amplification of recombinant HTTex1 assemblies in cell culture models. We find that small HTTex1 fibrils preferentially enter human neurons and trigger the amplification of neurotoxic assemblies; astrocytes or epithelial cells are not permissive. The amplification of HTTex1 in neurons depletes endogenous HTT protein with non-pathogenic polyQ repeat, activates apoptotic caspase-3 pathway and induces nuclear fragmentation. Using a panel of novel monoclonal antibodies and genetic mutation, we identified epitopes within the N-terminal 17 amino acids and proline-rich domain of HTTex1 to be critical in neural uptake and amplification. Synaptosome preparations from the brain homogenates of HD mice also contain mutant HTT species, which enter neurons and behave similar to small recombinant HTTex1 fibrils. These studies suggest that amyloidogenic extracellular mutant HTTex1 assemblies may preferentially enter neurons, propagate and promote neurodegeneration.
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Affiliation(s)
| | - J Mario Isas
- Zilkha Neurogenetic Institute, Keck School of Medicine of USC, Los Angeles, CA 90089, USA
| | - Nitin K Pandey
- Zilkha Neurogenetic Institute, Keck School of Medicine of USC, Los Angeles, CA 90089, USA
| | - Anoop Rawat
- Zilkha Neurogenetic Institute, Keck School of Medicine of USC, Los Angeles, CA 90089, USA
| | - Jung Hyun Yoo
- Biology and Bioengineering, Caltech, Pasadena, CA 91125, USA
| | - Tara Mastro
- Biology and Bioengineering, Caltech, Pasadena, CA 91125, USA
| | - Mary B Kennedy
- Biology and Bioengineering, Caltech, Pasadena, CA 91125, USA
| | - Ralf Langen
- Zilkha Neurogenetic Institute, Keck School of Medicine of USC, Los Angeles, CA 90089, USA
| | - Ali Khoshnan
- Biology and Bioengineering, Caltech, Pasadena, CA 91125, USA.
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22
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Lakpa KL, Khan N, Afghah Z, Chen X, Geiger JD. Lysosomal Stress Response (LSR): Physiological Importance and Pathological Relevance. J Neuroimmune Pharmacol 2021; 16:219-237. [PMID: 33751445 PMCID: PMC8099033 DOI: 10.1007/s11481-021-09990-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/08/2021] [Indexed: 02/08/2023]
Abstract
Extensive work has characterized endoplasmic reticulum (ER) and mitochondrial stress responses. In contrast, very little has been published about stress responses in lysosomes; subcellular acidic organelles that are physiologically important and are of pathological relevance. The greater lysosomal system is dynamic and is comprised of endosomes, lysosomes, multivesicular bodies, autophagosomes, and autophagolysosomes. They are important regulators of cellular physiology, they represent about 5% of the total cellular volume, they are heterogeneous in their sizes and distribution patterns, they are electron dense, and their subcellular positioning within cells varies in response to stimuli, insults and pH. These organelles are also integral to the pathogenesis of lysosomal storage diseases and it is increasingly recognized that lysosomes play important roles in the pathogenesis of such diverse conditions as neurodegenerative disorders and cancer. The purpose of this review is to focus attention on lysosomal stress responses (LSR), compare LSR with better characterized stress responses in ER and mitochondria, and form a framework for future characterizations of LSR. We synthesized data into the concept of LSR and present it here such that the definition of LSR can be modified as new knowledge is added and specific therapeutics are developed.
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Affiliation(s)
- Koffi L Lakpa
- Department of Biomedical Sciences, Dakota School of Medicine and Health Sciences, University of North, Grand Forks, ND, 58203, USA
| | - Nabab Khan
- Department of Biomedical Sciences, Dakota School of Medicine and Health Sciences, University of North, Grand Forks, ND, 58203, USA
| | - Zahra Afghah
- Department of Biomedical Sciences, Dakota School of Medicine and Health Sciences, University of North, Grand Forks, ND, 58203, USA
| | - Xuesong Chen
- Department of Biomedical Sciences, Dakota School of Medicine and Health Sciences, University of North, Grand Forks, ND, 58203, USA
| | - Jonathan D Geiger
- Department of Biomedical Sciences, Dakota School of Medicine and Health Sciences, University of North, Grand Forks, ND, 58203, USA.
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23
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Kuang X, Nunn K, Jiang J, Castellano P, Hardikar U, Horgan A, Kong J, Tan Z, Dai W. Structural insight into transmissive mutant huntingtin species by correlative light and electron microscopy and cryo-electron tomography. Biochem Biophys Res Commun 2021; 560:99-104. [PMID: 33984771 DOI: 10.1016/j.bbrc.2021.04.124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 04/29/2021] [Indexed: 02/07/2023]
Abstract
Aggregates of mutant huntingtin (mHTT) containing an expanded polyglutamine (polyQ) tract are hallmarks of Huntington's Disease (HD). Studies have shown that mHTT can spread between cells, leading to the propagation of misfolded protein pathology. However, the structure of transmissive mHTT species, and the molecular mechanisms underlying their transmission remain unknown. Using correlative light and electron microscopy (CLEM) and cryo-electron tomography (cryo-ET), we identified two types of aggregation-prone granules in conditioned medium from PC12 cells expressing a mHTT N-terminal fragment: densities enclosed by extracellular vesicles (EVs), and uncoated, amorphous meshworks of heterogeneous oligomers that co-localize with clusters of EVs. In vitro assays confirmed that liposomes induce condensation of polyQ oligomers into higher-order assemblies, resembling the uncoated meshworks observed in PC12 conditioned medium. Our findings provide novel insights into formation and architecture of transmissive mHTT proteins, and highlight the potential role of EVs as both carriers and modulators of transmissive mHTT proteins.
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Affiliation(s)
- Xuyuan Kuang
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Department of Hyperbaric Oxygen, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Kyle Nunn
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Jennifer Jiang
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Paul Castellano
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Uttara Hardikar
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Arianna Horgan
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Joyce Kong
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Zhiqun Tan
- Department of Anatomy and Neurobiology, University of California Irvine School of Medicine, Irvine, CA, 29697, USA; Institute for Memory Impairment and Neurological Disorders, University of California-Irvine, Irvine, CA, 29697, USA.
| | - Wei Dai
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA; Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA.
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24
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Onur TS, Laitman A, Zhao H, Keyho R, Kim H, Wang J, Mair M, Wang H, Li L, Perez A, de Haro M, Wan YW, Allen G, Lu B, Al-Ramahi I, Liu Z, Botas J. Downregulation of glial genes involved in synaptic function mitigates Huntington's disease pathogenesis. eLife 2021; 10:64564. [PMID: 33871358 PMCID: PMC8149125 DOI: 10.7554/elife.64564] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 04/19/2021] [Indexed: 01/01/2023] Open
Abstract
Most research on neurodegenerative diseases has focused on neurons, yet glia help form and maintain the synapses whose loss is so prominent in these conditions. To investigate the contributions of glia to Huntington's disease (HD), we profiled the gene expression alterations of Drosophila expressing human mutant Huntingtin (mHTT) in either glia or neurons and compared these changes to what is observed in HD human and HD mice striata. A large portion of conserved genes are concordantly dysregulated across the three species; we tested these genes in a high-throughput behavioral assay and found that downregulation of genes involved in synapse assembly mitigated pathogenesis and behavioral deficits. To our surprise, reducing dNRXN3 function in glia was sufficient to improve the phenotype of flies expressing mHTT in neurons, suggesting that mHTT's toxic effects in glia ramify throughout the brain. This supports a model in which dampening synaptic function is protective because it attenuates the excitotoxicity that characterizes HD. When a neuron dies, through injury or disease, the body loses all communication that passes through it. The brain compensates by rerouting the flow of information through other neurons in the network. Eventually, if the loss of neurons becomes too great, compensation becomes impossible. This process happens in Alzheimer's, Parkinson's, and Huntington's disease. In the case of Huntington's disease, the cause is mutation to a single gene known as huntingtin. The mutation is present in every cell in the body but causes particular damage to parts of the brain involved in mood, thinking and movement. Neurons and other cells respond to mutations in the huntingtin gene by turning the activities of other genes up or down, but it is not clear whether all of these changes contribute to the damage seen in Huntington's disease. In fact, it is possible that some of the changes are a result of the brain trying to protect itself. So far, most research on this subject has focused on neurons because the huntingtin gene plays a role in maintaining healthy neuronal connections. But, given that all cells carry the mutated gene, it is likely that other cells are also involved. The glia are a diverse group of cells that support the brain, providing care and sustenance to neurons. These cells have a known role in maintaining the connections between neurons and may also have play a role in either causing or correcting the damage seen in Huntington's disease. The aim of Onur et al. was to find out which genes are affected by having a mutant huntingtin gene in neurons or glia, and whether severity of Huntington’s disease improved or worsened when the activity of these genes changed. First, Onur et al. identified genes affected by mutant huntingtin by comparing healthy human brains to the brains of people with Huntington's disease. Repeating the same comparison in mice and fruit flies identified genes affected in the same way across all three species, revealing that, in Huntington's disease, the brain dials down glial cell genes involved in maintaining neuronal connections. To find out how these changes in gene activity affect disease severity and progression, Onur et al. manipulated the activity of each of the genes they had identified in fruit flies that carried mutant versions of huntingtin either in neurons, in glial cells or in both cell types. They then filmed the flies to see the effects of the manipulation on movement behaviors, which are affected by Huntington’s disease. This revealed that purposely lowering the activity of the glial genes involved in maintaining connections between neurons improved the symptoms of the disease, but only in flies who had mutant huntingtin in their glial cells. This indicates that the drop in activity of these genes observed in Huntington’s disease is the brain trying to protect itself. This work suggests that it is important to include glial cells in studies of neurological disorders. It also highlights the fact that changes in gene expression as a result of a disease are not always bad. Many alterations are compensatory, and try to either make up for or protect cells affected by the disease. Therefore, it may be important to consider whether drugs designed to treat a condition by changing levels of gene activity might undo some of the body's natural protection. Working out which changes drive disease and which changes are protective will be essential for designing effective treatments.
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Affiliation(s)
- Tarik Seref Onur
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Genetics & Genomics Graduate Program, Baylor College of Medicine, Houston, United States
| | - Andrew Laitman
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Quantitative & Computational Biosciences, Baylor College of Medicine, Houston, United States.,Department of Pediatrics, Baylor College of Medicine, Houston, United States
| | - He Zhao
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Ryan Keyho
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Hyemin Kim
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Jennifer Wang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Megan Mair
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Genetics & Genomics Graduate Program, Baylor College of Medicine, Houston, United States
| | - Huilan Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Lifang Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Alma Perez
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Maria de Haro
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Ying-Wooi Wan
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Genevera Allen
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Departments of Electrical & Computer Engineering, Statistics and Computer Science, Rice University, Houston, United States
| | - Boxun Lu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Ismael Al-Ramahi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Zhandong Liu
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Quantitative & Computational Biosciences, Baylor College of Medicine, Houston, United States.,Department of Pediatrics, Baylor College of Medicine, Houston, United States
| | - Juan Botas
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States.,Genetics & Genomics Graduate Program, Baylor College of Medicine, Houston, United States.,Quantitative & Computational Biosciences, Baylor College of Medicine, Houston, United States
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25
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Wang H, Zhang Z, Guan J, Lu W, Zhan C. Unraveling GLUT-mediated transcytosis pathway of glycosylated nanodisks. Asian J Pharm Sci 2021; 16:120-128. [PMID: 33613735 PMCID: PMC7878461 DOI: 10.1016/j.ajps.2020.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/08/2020] [Accepted: 07/06/2020] [Indexed: 12/14/2022] Open
Abstract
Glucose transporter (GLUT)-mediated transcytosis has been validated as an efficient method to cross the blood-brain barrier and enhance brain transport of nanomedicines. However, the transcytosis process remains elusive. Glycopeptide-modified nanodisks (Gly-A7R-NDs), which demonstrated high capacity of brain targeting via GLUT-mediated transcytosis in our previous reports, were utilized to better understand the whole transcytosis process. Gly-A7R-NDs internalized brain capillary endothelial cells mainly via GLUT-mediated/clathrin dependent endocytosis and macropinocytosis. The intracellular Gly-A7R-NDs remained intact, and the main excretion route of Gly-A7R-NDs was lysosomal exocytosis. Glycosylation of nanomedicine was crucial in GLUT-mediated transcytosis, while morphology did not affect the efficiency. This study highlights the pivotal roles of lysosomal exocytosis in the process of GLUT-mediated transcytosis, providing a new impetus to development of brain targeting drug delivery by accelerating lysosomal exocytosis.
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Affiliation(s)
- Huan Wang
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200032, China
- Center of Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 201399, China
- School of Pharmacy, Fudan University and Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education and PLA, Shanghai 201203, China
| | - Zui Zhang
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200032, China
| | - Juan Guan
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200032, China
- School of Pharmacy, Fudan University and Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education and PLA, Shanghai 201203, China
| | - Weiyue Lu
- School of Pharmacy, Fudan University and Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education and PLA, Shanghai 201203, China
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Changyou Zhan
- Department of Pharmacology, School of Basic Medical Sciences and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200032, China
- Center of Medical Research and Innovation, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 201399, China
- School of Pharmacy, Fudan University and Key Laboratory of Smart Drug Delivery (Fudan University), Ministry of Education and PLA, Shanghai 201203, China
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Mutant Huntingtin Is Cleared from the Brain via Active Mechanisms in Huntington Disease. J Neurosci 2020; 41:780-796. [PMID: 33310753 DOI: 10.1523/jneurosci.1865-20.2020] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 11/17/2020] [Accepted: 11/25/2020] [Indexed: 12/13/2022] Open
Abstract
Huntington disease (HD) is a neurodegenerative disease caused by a CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. Therapeutics that lower HTT have shown preclinical promise and are being evaluated in clinical trials. However, clinical assessment of brain HTT lowering presents challenges. We have reported that mutant HTT (mHTT) in the CSF of HD patients correlates with clinical measures, including disease burden as well as motor and cognitive performance. We have also shown that lowering HTT in the brains of HD mice results in correlative reduction of mHTT in the CSF, prompting the use of this measure as an exploratory marker of target engagement in clinical trials. In this study, we investigate the mechanisms of mHTT clearance from the brain in adult mice of both sexes to elucidate the significance of therapy-induced CSF mHTT changes. We demonstrate that, although neurodegeneration increases CSF mHTT concentrations, mHTT is also present in the CSF of mice in the absence of neurodegeneration. Importantly, we show that secretion of mHTT from cells in the CNS followed by glymphatic clearance from the extracellular space contributes to mHTT in the CSF. Furthermore, we observe secretion of wild type HTT from healthy control neurons, suggesting that HTT secretion is a normal process occurring in the absence of pathogenesis. Overall, our data support both passive release and active clearance of mHTT into CSF, suggesting that its treatment-induced changes may represent a combination of target engagement and preservation of neurons.SIGNIFICANCE STATEMENT: Changes in CSF mutant huntingtin (mHTT) are being used as an exploratory endpoint in HTT lowering clinical trials for the treatment of Huntington disease (HD). Recently, it was demonstrated that intrathecal administration of a HTT lowering agent leads to dose-dependent reduction of CSF mHTT in HD patients. However, little is known about how HTT, an intracellular protein, reaches the extracellular space and ultimately the CSF. Our findings that HTT enters CSF by both passive release and active secretion followed by glymphatic clearance may have significant implications for interpretation of treatment-induced changes of CSF mHTT in clinical trials for HD.
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García-Huerta P, Troncoso-Escudero P, Wu D, Thiruvalluvan A, Cisternas-Olmedo M, Henríquez DR, Plate L, Chana-Cuevas P, Saquel C, Thielen P, Longo KA, Geddes BJ, Lederkremer GZ, Sharma N, Shenkman M, Naphade S, Sardi SP, Spichiger C, Richter HG, Court FA, Tshilenge KT, Ellerby LM, Wiseman RL, Gonzalez-Billault C, Bergink S, Vidal RL, Hetz C. Insulin-like growth factor 2 (IGF2) protects against Huntington's disease through the extracellular disposal of protein aggregates. Acta Neuropathol 2020; 140:737-764. [PMID: 32642868 PMCID: PMC8513574 DOI: 10.1007/s00401-020-02183-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/06/2020] [Accepted: 06/19/2020] [Indexed: 12/13/2022]
Abstract
Impaired neuronal proteostasis is a salient feature of many neurodegenerative diseases, highlighting alterations in the function of the endoplasmic reticulum (ER). We previously reported that targeting the transcription factor XBP1, a key mediator of the ER stress response, delays disease progression and reduces protein aggregation in various models of neurodegeneration. To identify disease modifier genes that may explain the neuroprotective effects of XBP1 deficiency, we performed gene expression profiling of brain cortex and striatum of these animals and uncovered insulin-like growth factor 2 (Igf2) as the major upregulated gene. Here, we studied the impact of IGF2 signaling on protein aggregation in models of Huntington's disease (HD) as proof of concept. Cell culture studies revealed that IGF2 treatment decreases the load of intracellular aggregates of mutant huntingtin and a polyglutamine peptide. These results were validated using induced pluripotent stem cells (iPSC)-derived medium spiny neurons from HD patients and spinocerebellar ataxia cases. The reduction in the levels of mutant huntingtin was associated with a decrease in the half-life of the intracellular protein. The decrease in the levels of abnormal protein aggregation triggered by IGF2 was independent of the activity of autophagy and the proteasome pathways, the two main routes for mutant huntingtin clearance. Conversely, IGF2 signaling enhanced the secretion of soluble mutant huntingtin species through exosomes and microvesicles involving changes in actin dynamics. Administration of IGF2 into the brain of HD mice using gene therapy led to a significant decrease in the levels of mutant huntingtin in three different animal models. Moreover, analysis of human postmortem brain tissue and blood samples from HD patients showed a reduction in IGF2 level. This study identifies IGF2 as a relevant factor deregulated in HD, operating as a disease modifier that buffers the accumulation of abnormal protein species.
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Affiliation(s)
- Paula García-Huerta
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Sector B, Second Floor, Faculty of Medicine, University of Chile, Independencia 1027, P.O. Box 70086, Santiago, Chile
| | - Paulina Troncoso-Escudero
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Sector B, Second Floor, Faculty of Medicine, University of Chile, Independencia 1027, P.O. Box 70086, Santiago, Chile
- Center for Integrative Biology, Faculty of Sciences, University Mayor, Santiago, Chile
| | - Di Wu
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Arun Thiruvalluvan
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Marisol Cisternas-Olmedo
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Center for Integrative Biology, Faculty of Sciences, University Mayor, Santiago, Chile
| | - Daniel R Henríquez
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Department of Cell Biology, Faculty of Sciences, University of Chile, Santiago, Chile
| | - Lars Plate
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Pedro Chana-Cuevas
- Faculty of Medical Sciences, University of Santiago de Chile, Santiago, Chile
| | - Cristian Saquel
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Center for Integrative Biology, Faculty of Sciences, University Mayor, Santiago, Chile
| | - Peter Thielen
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, 02115, USA
| | | | | | - Gerardo Z Lederkremer
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- George Wise Faculty of Life Sciences, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Neeraj Sharma
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- George Wise Faculty of Life Sciences, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Marina Shenkman
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- George Wise Faculty of Life Sciences, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Swati Naphade
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - S Pablo Sardi
- Rare and Neurological Diseases Therapeutic Area, Sanofi, 49 New York Avenue, Framingham, MA, 01701, USA
| | - Carlos Spichiger
- Faculty of Sciences, Institute of Biochemistry and Microbiology, University Austral of Chile, Valdivia, Chile
| | - Hans G Richter
- Faculty of Medicine, Institute of Anatomy, Histology and Pathology, University Austral of Chile, Valdivia, Chile
| | - Felipe A Court
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Center for Integrative Biology, Faculty of Sciences, University Mayor, Santiago, Chile
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | | | - Lisa M Ellerby
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - R Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Christian Gonzalez-Billault
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Department of Cell Biology, Faculty of Sciences, University of Chile, Santiago, Chile
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Steven Bergink
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Rene L Vidal
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile.
- Center for Integrative Biology, Faculty of Sciences, University Mayor, Santiago, Chile.
| | - Claudio Hetz
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile.
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Sector B, Second Floor, Faculty of Medicine, University of Chile, Independencia 1027, P.O. Box 70086, Santiago, Chile.
- Buck Institute for Research on Aging, Novato, CA, 94945, USA.
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Obaroakpo JU, Liu L, Zhang S, Lu J, Liu L, Pang X, Lv J. In vitro modulation of glucagon-like peptide release by DPP-IV inhibitory polyphenol-polysaccharide conjugates of sprouted quinoa yoghurt. Food Chem 2020; 324:126857. [DOI: 10.1016/j.foodchem.2020.126857] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 03/09/2020] [Accepted: 04/17/2020] [Indexed: 12/15/2022]
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Tang BL. Trafficking Unconventionally via UPS. Cells 2020; 9:cells9092009. [PMID: 32882862 PMCID: PMC7564385 DOI: 10.3390/cells9092009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 09/01/2020] [Indexed: 11/24/2022] Open
Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
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Yan W, Li T, Yin T, Hou Z, Qu K, Wang N, Durkan C, Dong L, Qiu J, Gregersen H, Wang G. M2 macrophage-derived exosomes promote the c-KIT phenotype of vascular smooth muscle cells during vascular tissue repair after intravascular stent implantation. Theranostics 2020; 10:10712-10728. [PMID: 32929376 PMCID: PMC7482821 DOI: 10.7150/thno.46143] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 08/13/2020] [Indexed: 12/13/2022] Open
Abstract
Rationale: For intravascular stent implantation to be successful, the processes of vascular tissue repair and therapy are considered to be critical. However, the mechanisms underlying the eventual fate of vascular smooth muscle cells (VSMCs) during vascular tissue repair remains elusive. In this study, we hypothesized that M2 macrophage-derived exosomes to mediate cell-to-cell crosstalk and induce dedifferentiation phenotypes in VSMCs. Methods: In vivo, 316L bare metal stents (BMS) were implanted from the left iliac artery into the abdominal aorta of 12-week-old male Sprague-Dawley (SD) rats for 7 and 28 days. Hematoxylin and eosin (HE) were used to stain the neointimal lesions. En-face immunofluorescence staining of smooth muscle 22 alpha (SM22α) and CD68 showed the rat aorta smooth muscle cells (RASMCs) and macrophages. Immunohistochemical staining of total galactose-specific lectin 3 (MAC-2) and total chitinase 3-like 3 (YM-1) showed the total macrophages and M2 macrophages. In vitro, exosomes derived from IL-4+IL-13-treated macrophages (M2Es) were isolated by ultracentrifugation and characterized based on their specific morphology. Ki-67 staining was conducted to assess the effects of the M2Es on the proliferation of RASMCs. An atomic force microscope (AFM) was used to detect the stiffness of the VSMCs. GW4869 was used to inhibit exosome release. RNA-seq was performed to determine the mRNA profiles of the RASMCs and M2Es-treated RASMCs. Quantitative real-time PCR (qRT-PCR) analysis was conducted to detect the expression levels of the mRNAs. Western blotting was used to detect the candidate protein expression levels. T-5224 was used to inhibit the DNA binding activity of AP-1 in RASMCs. Results: M2Es promote c-KIT expression and softening of nearby VSMCs, hence accelerating the vascular tissue repair process. VSMCs co-cultured in vitro with M2 macrophages presented an increased capacity for de-differentiation and softening, which was exosome dependent. In addition, the isolated M2Es helped to promote VSMC dedifferentiation and softening. Furthermore, the M2Es enhanced vascular tissue repair potency by upregulation of VSMCs c-KIT expression via activation of the c-Jun/activator protein 1 (AP-1) signaling pathway. Conclusions: The findings of this study emphasize the prominent role of M2Es during VSMC dedifferentiation and vascular tissue repair via activation of the c-Jun/AP-1 signaling pathway, which has a profound impact on the therapeutic strategies of coronary stenting techniques.
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C. elegans Models to Study the Propagation of Prions and Prion-Like Proteins. Biomolecules 2020; 10:biom10081188. [PMID: 32824215 PMCID: PMC7464663 DOI: 10.3390/biom10081188] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/10/2020] [Accepted: 08/13/2020] [Indexed: 12/14/2022] Open
Abstract
A hallmark common to many age-related neurodegenerative diseases, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS), is that patients develop proteinaceous deposits in their central nervous system (CNS). The progressive spreading of these inclusions from initially affected sites to interconnected brain areas is reminiscent of the behavior of bona fide prions in transmissible spongiform encephalopathies (TSEs), hence the term prion-like proteins has been coined. Despite intensive research, the exact mechanisms that facilitate the spreading of protein aggregation between cells, and the associated loss of neurons, remain poorly understood. As population demographics in many countries continue to shift to higher life expectancy, the incidence of neurodegenerative diseases is also rising. This represents a major challenge for healthcare systems and patients’ families, since patients require extensive support over several years and there is still no therapy to cure or stop these diseases. The model organism Caenorhabditis elegans offers unique opportunities to accelerate research and drug development due to its genetic amenability, its transparency, and the high degree of conservation of molecular pathways. Here, we will review how recent studies that utilize this soil dwelling nematode have proceeded to investigate the propagation and intercellular transmission of prions and prion-like proteins and discuss their relevance by comparing their findings to observations in other model systems and patients.
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32
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Wong CO. Endosomal-Lysosomal Processing of Neurodegeneration-Associated Proteins in Astrocytes. Int J Mol Sci 2020; 21:ijms21145149. [PMID: 32708198 PMCID: PMC7404029 DOI: 10.3390/ijms21145149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/17/2020] [Accepted: 07/18/2020] [Indexed: 12/15/2022] Open
Abstract
Most common neurodegenerative diseases (NDs) are characterized by deposition of protein aggregates that are resulted from misfolding, dysregulated trafficking, and compromised proteolytic degradation. These proteins exert cellular toxicity to a broad range of brain cells and are found in both neurons and glia. Extracellular monomeric and oligomeric ND-associated proteins are taken up by astrocytes, the most abundant glial cell in the brain. Internalization, intracellular trafficking, processing, and disposal of these proteins are executed by the endosomal-lysosomal system of astrocytes. Endosomal-lysosomal organelles thus mediate the cellular impact and metabolic fate of these toxic protein species. Given the indispensable role of astrocytes in brain metabolic homeostasis, the endosomal-lysosomal processing of these proteins plays a fundamental role in altering the trajectory of neurodegeneration. This review aims at summarizing the mounting evidence that has established the essential role of astrocytic endosomal-lysosomal organelles in the processing of amyloid precursor proteins, Apolipoprotein E (ApoE), tau, alpha synuclein, and huntingtin, which are associated with NDs such as Alzheimer’s, Parkinson’s, and Huntington diseases.
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Affiliation(s)
- Ching-On Wong
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
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33
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Nucleocytoplasmic Proteomic Analysis Uncovers eRF1 and Nonsense-Mediated Decay as Modifiers of ALS/FTD C9orf72 Toxicity. Neuron 2020; 106:90-107.e13. [PMID: 32059759 DOI: 10.1016/j.neuron.2020.01.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 12/08/2019] [Accepted: 01/15/2020] [Indexed: 12/13/2022]
Abstract
The most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) is a hexanucleotide repeat expansion in C9orf72 (C9-HRE). While RNA and dipeptide repeats produced by C9-HRE disrupt nucleocytoplasmic transport, the proteins that become redistributed remain unknown. Here, we utilized subcellular fractionation coupled with tandem mass spectrometry and identified 126 proteins, enriched for protein translation and RNA metabolism pathways, which collectively drive a shift toward a more cytosolic proteome in C9-HRE cells. Among these was eRF1, which regulates translation termination and nonsense-mediated decay (NMD). eRF1 accumulates within elaborate nuclear envelope invaginations in patient induced pluripotent stem cell (iPSC) neurons and postmortem tissue and mediates a protective shift from protein translation to NMD-dependent mRNA degradation. Overexpression of eRF1 and the NMD driver UPF1 ameliorate C9-HRE toxicity in vivo. Our findings provide a resource for proteome-wide nucleocytoplasmic alterations across neurodegeneration-associated repeat expansion mutations and highlight eRF1 and NMD as therapeutic targets in C9orf72-associated ALS and/or FTD.
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Abstract
Lysosomes are membrane-bound organelles with roles in processes involved in degrading and recycling cellular waste, cellular signalling and energy metabolism. Defects in genes encoding lysosomal proteins cause lysosomal storage disorders, in which enzyme replacement therapy has proved successful. Growing evidence also implicates roles for lysosomal dysfunction in more common diseases including inflammatory and autoimmune disorders, neurodegenerative diseases, cancer and metabolic disorders. With a focus on lysosomal dysfunction in autoimmune disorders and neurodegenerative diseases - including lupus, rheumatoid arthritis, multiple sclerosis, Alzheimer disease and Parkinson disease - this Review critically analyses progress and opportunities for therapeutically targeting lysosomal proteins and processes, particularly with small molecules and peptide drugs.
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Affiliation(s)
- Srinivasa Reddy Bonam
- CNRS-University of Strasbourg, Biotechnology and Cell Signalling, Illkirch, France
- Laboratory of Excellence Medalis, Team Neuroimmunology and Peptide Therapy, Institut de Science et d'Ingénierie Supramoléculaire (ISIS), Strasbourg, France
| | - Fengjuan Wang
- CNRS-University of Strasbourg, Biotechnology and Cell Signalling, Illkirch, France
- Laboratory of Excellence Medalis, Team Neuroimmunology and Peptide Therapy, Institut de Science et d'Ingénierie Supramoléculaire (ISIS), Strasbourg, France
| | - Sylviane Muller
- CNRS-University of Strasbourg, Biotechnology and Cell Signalling, Illkirch, France.
- Laboratory of Excellence Medalis, Team Neuroimmunology and Peptide Therapy, Institut de Science et d'Ingénierie Supramoléculaire (ISIS), Strasbourg, France.
- University of Strasbourg Institute for Advanced Study, Strasbourg, France.
- Fédération Hospitalo-Universitaire OMICARE, Fédération de Médecine Translationnelle de Strasbourg, Strasbourg University, Strasbourg, France.
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35
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Ko J, Isas JM, Sabbaugh A, Yoo JH, Pandey NK, Chongtham A, Ladinsky M, Wu WL, Rohweder H, Weiss A, Macdonald D, Munoz-Sanjuan I, Langen R, Patterson PH, Khoshnan A. Identification of distinct conformations associated with monomers and fibril assemblies of mutant huntingtin. Hum Mol Genet 2019; 27:2330-2343. [PMID: 29912367 DOI: 10.1093/hmg/ddy141] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 04/12/2018] [Accepted: 04/16/2018] [Indexed: 11/14/2022] Open
Abstract
The N-terminal fragments of mutant huntingtin (mHTT) misfold and assemble into oligomers, which ultimately bundle into insoluble fibrils. Conformations unique to various assemblies of mHTT remain unknown. Knowledge on the half-life of various multimeric structures of mHTT is also scarce. Using a panel of four new antibodies named PHP1-4, we have identified new conformations in monomers and assembled structures of mHTT. PHP1 and PHP2 bind to epitopes within the proline-rich domain (PRD), whereas PHP3 and PHP4 interact with motifs formed at the junction of polyglutamine (polyQ) and polyproline (polyP) repeats of HTT. The PHP1- and PHP2-reactive epitopes are exposed in fibrils of mHTT exon1 (mHTTx1) generated from recombinant proteins and mHTT assemblies, which progressively accumulate in the nuclei, cell bodies and neuropils in the brains of HD mouse models. Notably, electron microscopic examination of brain sections of HD mice revealed that PHP1- and PHP2-reactive mHTT assemblies are present in myelin sheath and in vesicle-like structures. Moreover, PHP1 and PHP2 antibodies block seeding and subsequent fibril assembly of mHTTx1 in vitro and in a cell culture model of HD. PHP3 and PHP4 bind to epitopes in full-length and N-terminal fragments of monomeric mHTT and binding diminishes as the mHTTx1 assembles into fibrils. Interestingly, PHP3 and PHP4 also prevent the aggregation of mHTTx1 in vitro highlighting a regulatory function for the polyQ-polyP motifs. These newly detected conformations may affect fibril assembly, stability and intercellular transport of mHTT.
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Affiliation(s)
- Jan Ko
- Biology and Bioengineering, Caltech, Pasadena, CA 91125, USA
| | - J Mario Isas
- Zilka Neurogenetic Institute, Keck School of Medicine of USC, Los Angeles, CA 90089, USA
| | - Adam Sabbaugh
- Biology and Bioengineering, Caltech, Pasadena, CA 91125, USA
| | - Jung Hyun Yoo
- Biology and Bioengineering, Caltech, Pasadena, CA 91125, USA
| | - Nitin K Pandey
- Zilka Neurogenetic Institute, Keck School of Medicine of USC, Los Angeles, CA 90089, USA
| | | | - Mark Ladinsky
- Biology and Bioengineering, Caltech, Pasadena, CA 91125, USA
| | - Wei-Li Wu
- Biology and Bioengineering, Caltech, Pasadena, CA 91125, USA
| | | | - Andreas Weiss
- Evotec, Manfred Eigen Campus, Hamburg 22419, Germany
| | | | | | - Ralf Langen
- Zilka Neurogenetic Institute, Keck School of Medicine of USC, Los Angeles, CA 90089, USA
| | | | - Ali Khoshnan
- Biology and Bioengineering, Caltech, Pasadena, CA 91125, USA
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Webster JM, Darling AL, Uversky VN, Blair LJ. Small Heat Shock Proteins, Big Impact on Protein Aggregation in Neurodegenerative Disease. Front Pharmacol 2019; 10:1047. [PMID: 31619995 PMCID: PMC6759932 DOI: 10.3389/fphar.2019.01047] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 08/19/2019] [Indexed: 12/15/2022] Open
Abstract
Misfolding, aggregation, and aberrant accumulation of proteins are central components in the progression of neurodegenerative disease. Cellular molecular chaperone systems modulate proteostasis, and, therefore, are primed to influence aberrant protein-induced neurotoxicity and disease progression. Molecular chaperones have a wide range of functions from facilitating proper nascent folding and refolding to degradation or sequestration of misfolded substrates. In disease states, molecular chaperones can display protective or aberrant effects, including the promotion and stabilization of toxic protein aggregates. This seems to be dependent on the aggregating protein and discrete chaperone interaction. Small heat shock proteins (sHsps) are a class of molecular chaperones that typically associate early with misfolded proteins. These interactions hold proteins in a reversible state that helps facilitate refolding or degradation by other chaperones and co-factors. These sHsp interactions require dynamic oligomerization state changes in response to diverse cellular triggers and, unlike later steps in the chaperone cascade of events, are ATP-independent. Here, we review evidence for modulation of neurodegenerative disease-relevant protein aggregation by sHsps. This includes data supporting direct physical interactions and potential roles of sHsps in the stewardship of pathological protein aggregates in brain. A greater understanding of the mechanisms of sHsp chaperone activity may help in the development of novel therapeutic strategies to modulate the aggregation of pathological, amyloidogenic proteins. sHsps-targeting strategies including modulators of expression or post-translational modification of endogenous sHsps, small molecules targeted to sHsp domains, and delivery of engineered molecular chaperones, are also discussed.
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Affiliation(s)
- Jack M Webster
- Department of Molecular Medicine, USF Byrd Institute, University of South Florida, Tampa, FL, United States
| | - April L Darling
- Department of Molecular Medicine, USF Byrd Institute, University of South Florida, Tampa, FL, United States
| | - Vladimir N Uversky
- Department of Molecular Medicine, USF Byrd Institute, University of South Florida, Tampa, FL, United States
| | - Laura J Blair
- Department of Molecular Medicine, USF Byrd Institute, University of South Florida, Tampa, FL, United States
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Ferguson R, Subramanian V. The secretion of the angiogenic and neurotrophic factor angiogenin is COPII and microtubule dependent. Exp Cell Res 2019; 381:265-279. [PMID: 31128105 DOI: 10.1016/j.yexcr.2019.05.025] [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: 03/08/2019] [Revised: 05/10/2019] [Accepted: 05/19/2019] [Indexed: 10/26/2022]
Abstract
The RNaseA superfamily member Angiogenin (ANG) is a secreted protein involved in neovascularization, cell proliferation and stress response. Dysregulation of ANG expression is found in many cancers with poor prognosis and mutations in ANG are associated with neurodegenerative diseases. While the uptake and nuclear translocation of ANG is relatively well characterised, little is known about how it reaches the plasma membrane and its mode of secretion. We generated SH-SY5Y neuroblastoma cell lines constitutively expressing wild type (WT) Hemagglutinin (HA) epitope tagged mouse Ang1 (mAng1), and two amyotrophic lateral sclerosis associated ANG variants (C39W and K40I). Herein, we show that these cell lines secrete mAng1 into the culture media. Using small molecule inhibitors we probed the route taken between the endoplasmic reticulum and trans-Golgi network during secretion and have characterised it as COPII and microtubule dependent. In addition, we show that disruption by the PI3-kinase inhibitor wortmannin of the later stages of transit to the plasma membrane leads to mAng1 trafficking to lysosomal compartments. This suggests an autophagy dependent regulation of secretion.
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Affiliation(s)
- Ross Ferguson
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY, UK
| | - Vasanta Subramanian
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY, UK.
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38
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Peng W, Minakaki G, Nguyen M, Krainc D. Preserving Lysosomal Function in the Aging Brain: Insights from Neurodegeneration. Neurotherapeutics 2019; 16:611-634. [PMID: 31183763 PMCID: PMC6694346 DOI: 10.1007/s13311-019-00742-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Lysosomes are acidic, membrane-bound organelles that serve as the primary catabolic compartment of the cell. They are crucial to a variety of cellular processes from nutrient storage to autophagy. Given the diversity of lysosomal functions, it is unsurprising that lysosomes are also emerging as important players in aging. Lysosomal dysfunction is implicated in several aging-related neurodegenerative diseases including Alzheimer's, Parkinson's, amyotrophic lateral sclerosis/frontotemporal dementia, and Huntington's. Although the precise role of lysosomes in the aging brain is not well-elucidated, some insight into their function has been gained from our understanding of the pathophysiology of age-dependent neurodegenerative diseases. Therapeutic strategies targeting lysosomes and autophagic machinery have already been tested in several of these diseases with promising results, suggesting that improving lysosomal function could be similarly beneficial in preserving function in the aging brain.
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Affiliation(s)
- Wesley Peng
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, 60611, USA
| | - Georgia Minakaki
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, 60611, USA
| | - Maria Nguyen
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, 60611, USA
| | - Dimitri Krainc
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, 60611, USA.
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39
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Pernègre C, Duquette A, Leclerc N. Tau Secretion: Good and Bad for Neurons. Front Neurosci 2019; 13:649. [PMID: 31293374 PMCID: PMC6606725 DOI: 10.3389/fnins.2019.00649] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 06/06/2019] [Indexed: 01/20/2023] Open
Abstract
In Alzheimer’s disease (AD), neurofibrillary tangles (NFTs), lesions composed of hyperphosphorylated and aggregated tau, spread from the transentorhinal cortex to the hippocampal formation and neocortex. Growing evidence indicates that tau pathology propagates trans-synaptically, implying that pathological tau released by pre-synaptic neurons is taken up by post-synaptic neurons where it accumulates and aggregates. Observations such as the presence of tau in the cerebrospinal fluid (CSF) from control individuals and in the CSF of transgenic mice overexpressing human tau before the detection of neuronal death indicate that tau can be secreted by neurons. The increase of tau in the CSF in pathological conditions such as AD suggests that tau secretion is enhanced and/or other secretory pathways take place when neuronal function is compromised. In physiological conditions, extracellular tau could exert beneficial effects as observed for other cytosolic proteins also released in the extracellular space. In such a case, blocking tau secretion could have negative effects on neurons unless the mechanism of tau secretion are different in physiological and pathological conditions allowing the prevention of pathological tau secretion without affecting the secretion of physiological tau. Furthermore, distinct extracellular tau species could be secreted in physiological and pathological conditions, species having the capacity to induce tau pathology being only secreted in the latter condition. In the present review, we will focus on the mechanisms and function of tau secretion in both physiological and pathological conditions and how this information can help to elaborate an efficient therapeutic strategy to prevent tau pathology and its propagation.
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Affiliation(s)
- Camille Pernègre
- Research Centre of the University of Montreal Hospital (CRCHUM), Montréal, QC, Canada.,Département de Neurosciences, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Antoine Duquette
- Research Centre of the University of Montreal Hospital (CRCHUM), Montréal, QC, Canada.,Département de Neurosciences, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Nicole Leclerc
- Research Centre of the University of Montreal Hospital (CRCHUM), Montréal, QC, Canada.,Département de Neurosciences, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
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40
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Griffin EF, Yan X, Caldwell KA, Caldwell GA. Distinct functional roles of Vps41-mediated neuroprotection in Alzheimer's and Parkinson's disease models of neurodegeneration. Hum Mol Genet 2019; 27:4176-4193. [PMID: 30508205 DOI: 10.1093/hmg/ddy308] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 08/21/2018] [Indexed: 12/25/2022] Open
Abstract
Commonalities and, in some cases, pathological overlap between neurodegenerative diseases have led to speculation that targeting of underlying mechanisms might be of potentially shared therapeutic benefit. Alzheimer's disease is characterized by the formation of plaques, composed primarily of the amyloid-β 1-42 (Aβ) peptide in the brain, resulting in neurodegeneration. Previously, we have shown that overexpression of the lysosomal-trafficking protein, human Vps41 (hVps41), is neuroprotective in a transgenic worm model of Parkinson's disease, wherein progressive dopaminergic neurodegeneration is induced by α-synuclein overexpression. Here, we report the results of a systematic comparison of hVps41-mediated neuroprotection between α-synuclein and Aβ in transgenic nematode models of Caenorhabditis elegans. Our results indicate that an ARF-like GTPase gene product, ARL-8, mitigates endocytic Aβ neurodegeneration in a VPS-41-dependent manner, rather than through RAB-7 and AP3 as with α-synuclein. Furthermore, the neuroprotective effect of ARL-8 or hVps41 appears to be dependent on their colocalization and the activity of ARL-8. Additionally, we demonstrate that the LC3 orthologue, LGG-2, plays a critical role in Aβ toxicity with ARL-8. Further analysis of functional effectors of Aβ protein processing via the lysosomal pathway will assist in the elucidation of the underlying mechanism involving VPS-41-mediated neuroprotection. These results reveal functional distinctions in the intracellular management of neurotoxic proteins that serve to better inform the path for development of therapeutic interventions to halt neurodegeneration.
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Affiliation(s)
- Edward F Griffin
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, USA
| | | | - Kim A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, USA.,Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Nathan Shock Center for Research on the Basic Biology of Aging, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
| | - Guy A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, USA.,Departments of Neurology and Neurobiology, Center for Neurodegeneration and Experimental Therapeutics, Nathan Shock Center for Research on the Basic Biology of Aging, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
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41
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Recovery from tachyphylaxis of TRPV1 coincides with recycling to the surface membrane. Proc Natl Acad Sci U S A 2019; 116:5170-5175. [PMID: 30804201 DOI: 10.1073/pnas.1819635116] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The transient receptor potential vanilloid-1 (TRPV1) ion channel is essential for sensation of thermal and chemical pain. TRPV1 activation is accompanied by Ca2+-dependent desensitization; acute desensitization reflects rapid reduction in channel activity during stimulation, whereas tachyphylaxis denotes the diminution in TRPV1 responses to repetitive stimulation. Acute desensitization has been attributed to conformational changes of the TRPV1 channel; however, the mechanisms underlying the establishment of tachyphylaxis remain to be defined. Here, we report that the degree of whole-cell TRPV1 tachyphylaxis is regulated by the strength of inducing stimulation. Using light-sheet microscopy and pH-sensitive sensor pHluorin to follow TRPV1 endocytosis and exocytosis trafficking, we provide real-time information that tachyphylaxis of different degrees concurs with TRPV1 recycling to the plasma membrane in a proportional manner. This process controls TRPV1 surface expression level thereby the whole-cell nociceptive response. We further show that activity-gated TRPV1 trafficking associates with intracellular Ca2+ signals of distinct kinetics, and recruits recycling routes mediated by synaptotagmin 1 and 7, respectively. These results suggest that activity-dependent TRPV1 recycling contributes to the establishment of tachyphylaxis.
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42
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Trajkovic K, Valdez C, Ysselstein D, Krainc D. Fluctuations in cell density alter protein markers of multiple cellular compartments, confounding experimental outcomes. PLoS One 2019; 14:e0211727. [PMID: 30716115 PMCID: PMC6361456 DOI: 10.1371/journal.pone.0211727] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 01/19/2019] [Indexed: 11/23/2022] Open
Abstract
The life cycle of cultured proliferating cells is characterized by fluctuations in cell population density induced by periodic subculturing. This leads to corresponding changes in micro- and macroenvironment of the cells, accompanied by altered cellular metabolism, growth rate and locomotion. Studying cell density-dependent morphological, physiological and biochemical fluctuations is relevant for understanding basic cellular mechanisms and for uncovering the intrinsic variation of commonly used tissue culture experimental models. Using multiple cell lines, we found that expression levels of the autophagic markers p62 and LC3II, and lysosomal enzyme cathepsin D were altered in highly confluent cells as a consequence of nutrient depletion and cell crowding, which led to inactivation of the mTOR signaling pathway. Furthermore, both Lamp1 and active focal adhesion kinase (FAK) were reduced in high-density cells, while chemical inhibition or deletion of FAK led to alterations in lysosomal and autophagic proteins, as well as in the mTOR signaling. This was accompanied by alterations in the Hippo signaling pathway, while cell cycle checkpoint regulator p-cdc2 remained unaffected in at least one studied cell line. On the other hand, allometric scaling of cellular compartments in growing cell populations resulted in biochemically detectable changes in the plasma membrane proteins Na+K+-ATPase and cadherin, and nuclear proteins HDAC1 and Lamin B1. Finally, we demonstrate how treatment-induced changes in cell density and corresponding modulation of susceptible proteins may lead to ambiguous experimental outcomes, or erroneous interpretation of cell culture data. Together, our data emphasize the need to recognize cell density as an important experimental variable in order to improve scientific rigor of cell culture-based studies.
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Affiliation(s)
- Katarina Trajkovic
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
- * E-mail: (DK); (KT)
| | - Clarissa Valdez
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Daniel Ysselstein
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Dimitri Krainc
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
- * E-mail: (DK); (KT)
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43
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Trajkovic K, Krainc D. Novel Approach to Tracking Mutant Huntingtin in Biosamples. Trends Mol Med 2018; 24:978-981. [PMID: 30509361 DOI: 10.1016/j.molmed.2018.10.002] [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: 10/03/2018] [Revised: 10/09/2018] [Accepted: 10/10/2018] [Indexed: 10/28/2022]
Abstract
Although the established causative agent in Huntington's disease (HD) is a mutation in a single gene encoding huntingtin protein, the pathogenic cascade preceding neuronal death and disease onset is both incompletely understood and clinically undetectable. A new article published in Molecular Cell explores mutant huntingtin (mHtt) aggregate seeding activity as an early pathogenesis-tracking parameter with potential biomarker quality.
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Affiliation(s)
- Katarina Trajkovic
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Dimitri Krainc
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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44
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Lee J, Ye Y. The Roles of Endo-Lysosomes in Unconventional Protein Secretion. Cells 2018; 7:cells7110198. [PMID: 30400277 PMCID: PMC6262434 DOI: 10.3390/cells7110198] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 10/30/2018] [Accepted: 10/31/2018] [Indexed: 12/21/2022] Open
Abstract
Protein secretion in general depends on signal sequence (also named leader sequence), a hydrophobic segment located at or close to the NH2-terminus of a secretory or membrane protein. This sequence guides the entry of nascent polypeptides into the lumen or membranes of the endoplasmic reticulum (ER) for folding, assembly, and export. However, evidence accumulated in recent years has suggested the existence of a collection of unconventional protein secretion (UPS) mechanisms that are independent of the canonical vesicular trafficking route between the ER and the plasma membrane (PM). These UPS mechanisms export soluble proteins bearing no signal sequence. The list of UPS cargos is rapidly expanding, along with the implicated biological functions, but molecular mechanisms accountable for the secretion of leaderless proteins are still poorly defined. This review summarizes our current understanding of UPS mechanisms with an emphasis on the emerging role of endo-lysosomes in this process.
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Affiliation(s)
- Juhyung Lee
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Yihong Ye
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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45
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Regulation and Roles of Autophagy at Synapses. Trends Cell Biol 2018; 28:646-661. [DOI: 10.1016/j.tcb.2018.03.006] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/12/2018] [Accepted: 03/30/2018] [Indexed: 12/21/2022]
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46
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Vilette D, Courte J, Peyrin JM, Coudert L, Schaeffer L, Andréoletti O, Leblanc P. Cellular mechanisms responsible for cell-to-cell spreading of prions. Cell Mol Life Sci 2018; 75:2557-2574. [PMID: 29761205 PMCID: PMC11105574 DOI: 10.1007/s00018-018-2823-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/04/2018] [Accepted: 04/23/2018] [Indexed: 01/01/2023]
Abstract
Prions are infectious agents that cause fatal neurodegenerative diseases. Current evidence indicates that they are essentially composed of an abnormally folded protein (PrPSc). These abnormal aggregated PrPSc species multiply in infected cells by recruiting and converting the host PrPC protein into new PrPSc. How prions move from cell to cell and progressively spread across the infected tissue is of crucial importance and may provide experimental opportunity to delay the progression of the disease. In infected cells, different mechanisms have been identified, including release of infectious extracellular vesicles and intercellular transfer of PrPSc-containing organelles through tunneling nanotubes. These findings should allow manipulation of the intracellular trafficking events targeting PrPSc in these particular subcellular compartments to experimentally address the relative contribution of these mechanisms to in vivo prion pathogenesis. In addition, such information may prompt further experimental strategies to decipher the causal roles of protein misfolding and aggregation in other human neurodegenerative diseases.
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Affiliation(s)
- Didier Vilette
- UMR1225, INRA, ENVT, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, Toulouse, France.
| | - Josquin Courte
- Neurosciences Paris Seine, UMR8246, Inserm U1130, IBPS, UPMC, Sorbonne Universités, 4 Place Jussieu, 75005, Paris, France
- Laboratoire Physico Chimie Curie, UMR168, UPMC, IPGG, Sorbonne Universités, 6 Rue Jean Calvin, 75005, Paris, France
| | - Jean Michel Peyrin
- Neurosciences Paris Seine, UMR8246, Inserm U1130, IBPS, UPMC, Sorbonne Universités, 4 Place Jussieu, 75005, Paris, France.
| | - Laurent Coudert
- Insitut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon I, 8 Avenue Rockefeller, 69373, Lyon Cedex 08, France
| | - Laurent Schaeffer
- Insitut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon I, 8 Avenue Rockefeller, 69373, Lyon Cedex 08, France
| | - Olivier Andréoletti
- UMR1225, INRA, ENVT, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, Toulouse, France
| | - Pascal Leblanc
- Insitut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon I, 8 Avenue Rockefeller, 69373, Lyon Cedex 08, France.
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47
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Evers MM, Miniarikova J, Juhas S, Vallès A, Bohuslavova B, Juhasova J, Skalnikova HK, Vodicka P, Valekova I, Brouwers C, Blits B, Lubelski J, Kovarova H, Ellederova Z, van Deventer SJ, Petry H, Motlik J, Konstantinova P. AAV5-miHTT Gene Therapy Demonstrates Broad Distribution and Strong Human Mutant Huntingtin Lowering in a Huntington's Disease Minipig Model. Mol Ther 2018; 26:2163-2177. [PMID: 30007561 PMCID: PMC6127509 DOI: 10.1016/j.ymthe.2018.06.021] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 02/07/2023] Open
Abstract
Huntington’s disease (HD) is a fatal neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the huntingtin gene. Previously, we showed strong huntingtin reduction and prevention of neuronal dysfunction in HD rodents using an engineered microRNA targeting human huntingtin, delivered via adeno-associated virus (AAV) serotype 5 vector with a transgene encoding an engineered miRNA against HTT mRNA (AAV5-miHTT). One of the challenges of rodents as a model of neurodegenerative diseases is their relatively small brain, making successful translation to the HD patient difficult. This is particularly relevant for gene therapy approaches, where distribution achieved upon local administration into the parenchyma is likely dependent on brain size and structure. Here, we aimed to demonstrate the translation of huntingtin-lowering gene therapy to a large-animal brain. We investigated the feasibility, efficacy, and tolerability of one-time intracranial administration of AAV5-miHTT in the transgenic HD (tgHD) minipig model. We detected widespread dose-dependent distribution of AAV5-miHTT throughout the tgHD minipig brain that correlated with the engineered microRNA expression. Both human mutant huntingtin mRNA and protein were significantly reduced in all brain regions transduced by AAV5-miHTT. The combination of widespread vector distribution and extensive huntingtin lowering observed with AAV5-miHTT supports the translation of a huntingtin-lowering gene therapy for HD from preclinical studies into the clinic.
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Affiliation(s)
- Melvin M Evers
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands.
| | - Jana Miniarikova
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Stefan Juhas
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Astrid Vallès
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | | | - Jana Juhasova
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | | | - Petr Vodicka
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Ivona Valekova
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Cynthia Brouwers
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Bas Blits
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Jacek Lubelski
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Hana Kovarova
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Zdenka Ellederova
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Sander J van Deventer
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Harald Petry
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
| | - Jan Motlik
- Institute of Animal Physiology and Genetics, Libechov, Czech Republic
| | - Pavlina Konstantinova
- Department of Research & Development, uniQure biopharma B.V., Amsterdam, the Netherlands
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48
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Tang BL. Unconventional Secretion and Intercellular Transfer of Mutant Huntingtin. Cells 2018; 7:cells7060059. [PMID: 29904030 PMCID: PMC6025013 DOI: 10.3390/cells7060059] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 06/08/2018] [Accepted: 06/12/2018] [Indexed: 01/17/2023] Open
Abstract
The mechanism of intercellular transmission of pathological agents in neurodegenerative diseases has received much recent attention. Huntington’s disease (HD) is caused by a monogenic mutation in the gene encoding Huntingtin (HTT). Mutant HTT (mHTT) harbors a CAG repeat extension which encodes an abnormally long polyglutamine (polyQ) repeat at HTT’s N-terminus. Neuronal pathology in HD is largely due to the toxic gain-of-function by mHTT and its proteolytic products, which forms both nuclear and cytoplasmic aggregates that perturb nuclear gene transcription, RNA splicing and transport as well cellular membrane dynamics. The neuropathological effects of mHTT have been conventionally thought to be cell-autonomous in nature. Recent findings have, however, indicated that mHTT could be secreted by neurons, or transmitted from one neuronal cell to another via different modes of unconventional secretion, as well as via tunneling nanotubes (TNTs). These modes of transmission allow the intercellular spread of mHTT and its aggregates, thus plausibly promoting neuropathology within proximal neuronal populations and between neurons that are connected within neural circuits. Here, the various possible modes for mHTT’s neuronal cell exit and intercellular transmission are discussed.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, 117597 Singapore, Singapore.
- NUS Graduate School for Integrative Sciences and Engineering, 117456 Singapore, Singapore.
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49
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Bingol B. Autophagy and lysosomal pathways in nervous system disorders. Mol Cell Neurosci 2018; 91:167-208. [PMID: 29729319 DOI: 10.1016/j.mcn.2018.04.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 04/26/2018] [Accepted: 04/28/2018] [Indexed: 12/12/2022] Open
Abstract
Autophagy is an evolutionarily conserved pathway for delivering cytoplasmic cargo to lysosomes for degradation. In its classically studied form, autophagy is a stress response induced by starvation to recycle building blocks for essential cellular processes. In addition, autophagy maintains basal cellular homeostasis by degrading endogenous substrates such as cytoplasmic proteins, protein aggregates, damaged organelles, as well as exogenous substrates such as bacteria and viruses. Given their important role in homeostasis, autophagy and lysosomal machinery are genetically linked to multiple human disorders such as chronic inflammatory diseases, cardiomyopathies, cancer, and neurodegenerative diseases. Multiple targets within the autophagy and lysosomal pathways offer therapeutic opportunities to benefit patients with these disorders. Here, I will summarize the mechanisms of autophagy pathways, the evidence supporting a pathogenic role for disturbed autophagy and lysosomal degradation in nervous system disorders, and the therapeutic potential of autophagy modulators in the clinic.
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Affiliation(s)
- Baris Bingol
- Genentech, Inc., Department of Neuroscience, 1 DNA Way, South San Francisco 94080, United States.
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50
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Trajkovic K, Jeong H, Krainc D. Mutant Huntingtin Secretion in Neuro2A Cells and Rat Primary Cortical Neurons. Bio Protoc 2018; 8:e2675. [PMID: 29326963 DOI: 10.21769/bioprotoc.2675] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Quantitative analysis of proteins secreted from the cells poses a challenge due to their low abundance and the interfering presence of a large amount of bovine serum albumin (BSA) in the cell culture media. We established assays for detection of mutant huntingtin (mHtt) secreted from Neuro2A cell line stably expressing mHtt and rat primary cortical neurons by Western blotting. Our protocol is based on reducing the amounts of BSA in the media while maintaining cell viability and secretory potential, and concentrating the media prior to analysis by means of ultrafiltration.
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Affiliation(s)
- Katarina Trajkovic
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Hyunkyung Jeong
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Dimitri Krainc
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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