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Gustafsson G, Lindström V, Rostami J, Nordström E, Lannfelt L, Bergström J, Ingelsson M, Erlandsson A. Alpha-synuclein oligomer-selective antibodies reduce intracellular accumulation and mitochondrial impairment in alpha-synuclein exposed astrocytes. J Neuroinflammation 2017; 14:241. [PMID: 29228971 PMCID: PMC5725978 DOI: 10.1186/s12974-017-1018-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 12/01/2017] [Indexed: 11/29/2022] Open
Abstract
Background Due to its neurotoxic properties, oligomeric alpha-synuclein (α-syn) has been suggested as an attractive target for passive immunization against Parkinson’s disease (PD). In mouse models of PD, antibody treatment has been shown to lower the levels of pathogenic α-syn species, including oligomers, although the mechanisms of action remain unknown. We have previously shown that astrocytes rapidly engulf α-syn oligomers that are intracellularly stored, rather than degraded, resulting in impaired mitochondria. Methods The aim of the present study was to investigate if the accumulation of α-syn in astrocytes can be affected by α-syn oligomer-selective antibodies. Co-cultures of astrocytes, neurons, and oligodendrocytes were derived from embryonic mouse cortex and exposed to α-syn oligomers or oligomers pre-incubated with oligomer-selective antibodies. Results In the presence of antibodies, the astrocytes displayed an increased clearance of the exogenously added α-syn, and consequently, the α-syn accumulation in the culture was markedly reduced. Moreover, the addition of antibodies rescued the astrocytes from the oligomer-induced mitochondrial impairment. Conclusions Our results demonstrate that oligomer-selective antibodies can prevent α-syn accumulation and mitochondrial dysfunction in cultured astrocytes.
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Affiliation(s)
- Gabriel Gustafsson
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Veronica Lindström
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Jinar Rostami
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Eva Nordström
- BioArctic AB, Warfvinges väg 35, 112 51, Stockholm, Sweden
| | - Lars Lannfelt
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Joakim Bergström
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Martin Ingelsson
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden
| | - Anna Erlandsson
- Molecular Geriatrics, Department of Public Health and Caring Sciences, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden.
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52
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Krejciova Z, Alibhai J, Zhao C, Krencik R, Rzechorzek NM, Ullian EM, Manson J, Ironside JW, Head MW, Chandran S. Human stem cell-derived astrocytes replicate human prions in a PRNP genotype-dependent manner. J Exp Med 2017; 214:3481-3495. [PMID: 29141869 PMCID: PMC5716027 DOI: 10.1084/jem.20161547] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 08/07/2017] [Accepted: 09/27/2017] [Indexed: 01/09/2023] Open
Abstract
Prions are infectious agents that cause neurodegenerative diseases such as Creutzfeldt-Jakob disease (CJD). The absence of a human cell culture model that replicates human prions has hampered prion disease research for decades. In this paper, we show that astrocytes derived from human induced pluripotent stem cells (iPSCs) support the replication of prions from brain samples of CJD patients. For experimental exposure of astrocytes to variant CJD (vCJD), the kinetics of prion replication occur in a prion protein codon 129 genotype-dependent manner, reflecting the genotype-dependent susceptibility to clinical vCJD found in patients. Furthermore, iPSC-derived astrocytes can replicate prions associated with the major sporadic CJD strains found in human patients. Lastly, we demonstrate the subpassage of prions from infected to naive astrocyte cultures, indicating the generation of prion infectivity in vitro. Our study addresses a long-standing gap in the repertoire of human prion disease research, providing a new in vitro system for accelerated mechanistic studies and drug discovery.
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Affiliation(s)
- Zuzana Krejciova
- National CJD Research & Surveillance Unit, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK,Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, CA
| | - James Alibhai
- National CJD Research & Surveillance Unit, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Chen Zhao
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, Scotland, UK
| | - Robert Krencik
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, TX
| | - Nina M. Rzechorzek
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, Scotland, UK,Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Edinburgh, Scotland, UK
| | - Erik M. Ullian
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA
| | - Jean Manson
- Neurobiology Division, The Roslin Institute, University of Edinburgh, Edinburgh, Scotland, UK
| | - James W. Ironside
- National CJD Research & Surveillance Unit, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Mark W. Head
- National CJD Research & Surveillance Unit, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Siddharthan Chandran
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, Scotland, UK,UK Dementia Research Institute, University of Edinburgh, Edinburgh, Scotland, UK,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK,Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, National Centre for Biological Sciences, Bangalore, India,Correspondence to Siddharthan Chandran:
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53
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Human Astrocytes Transfer Aggregated Alpha-Synuclein via Tunneling Nanotubes. J Neurosci 2017; 37:11835-11853. [PMID: 29089438 PMCID: PMC5719970 DOI: 10.1523/jneurosci.0983-17.2017] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 09/20/2017] [Accepted: 10/11/2017] [Indexed: 12/30/2022] Open
Abstract
Many lines of evidence suggest that the Parkinson's disease (PD)-related protein α-synuclein (α-SYN) can propagate from cell to cell in a prion-like manner. However, the cellular mechanisms behind the spreading remain elusive. Here, we show that human astrocytes derived from embryonic stem cells actively transfer aggregated α-SYN to nearby astrocytes via direct contact and tunneling nanotubes (TNTs). Failure in the astrocytes' lysosomal digestion of excess α-SYN oligomers results in α-SYN deposits in the trans-Golgi network followed by endoplasmic reticulum swelling and mitochondrial disturbances. The stressed astrocytes respond by conspicuously sending out TNTs, enabling intercellular transfer of α-SYN to healthy astrocytes, which in return deliver mitochondria, indicating a TNT-mediated rescue mechanism. Using a pharmacological approach to inhibit TNT formation, we abolished the transfer of both α-SYN and mitochondria. Together, our results highlight the role of astrocytes in α-SYN cell-to-cell transfer, identifying possible pathophysiological events in the PD brain that could be of therapeutic relevance. SIGNIFICANCE STATEMENT Astrocytes are the major cell type in the brain, yet their role in Parkinson's disease progression remains elusive. Here, we show that human astrocytes actively transfer aggregated α-synuclein (α-SYN) to healthy astrocytes via direct contact and tunneling nanotubes (TNTs), rather than degrade it. The astrocytes engulf large amounts of oligomeric α-SYN that are subsequently stored in the trans-Golgi network region. The accumulation of α-SYN in the astrocytes affects their lysosomal machinery and induces mitochondrial damage. The stressed astrocytes respond by sending out TNTs, enabling intercellular transfer of α-SYN to healthy astrocytes. Our findings highlight an unexpected role of astrocytes in the propagation of α-SYN pathology via TNTs, revealing astrocytes as a potential target for therapeutic intervention.
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54
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Tang BL. The use of mesenchymal stem cells (MSCs) for amyotrophic lateral sclerosis (ALS) therapy – a perspective on cell biological mechanisms. Rev Neurosci 2017; 28:725-738. [DOI: 10.1515/revneuro-2017-0018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/04/2017] [Indexed: 12/12/2022]
Abstract
AbstractRecent clinical trials of mesenchymal stem cells (MSCs) transplantation have demonstrated procedural safety and clinical proof of principle with a modest indication of benefit in patients with amyotrophic lateral sclerosis (ALS). While replacement therapy remained unrealistic, the clinical efficacy of this therapeutic option could be potentially enhanced if we could better decipher the mechanisms underlying some of the beneficial effects of transplanted cells, and work toward augmenting or combining these in a strategic manner. Novel ways whereby MSCs could act in modifying disease progression should also be explored. In this review, I discuss the known, emerging and postulated mechanisms of action underlying effects that transplanted MSCs may exert to promote motor neuron survival and/or to encourage regeneration in ALS. I shall also speculate on how transplanted cells may alter the diseased environment so as to minimize non-neuron cell autonomous damages by immune cells and astrocytes.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University Health System, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Medical Drive, Singapore 117597, Singapore
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55
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Ferrer I. Diversity of astroglial responses across human neurodegenerative disorders and brain aging. Brain Pathol 2017; 27:645-674. [PMID: 28804999 PMCID: PMC8029391 DOI: 10.1111/bpa.12538] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/24/2017] [Indexed: 12/11/2022] Open
Abstract
Astrogliopathy refers to alterations of astrocytes occurring in diseases of the nervous system, and it implies the involvement of astrocytes as key elements in the pathogenesis and pathology of diseases and injuries of the central nervous system. Reactive astrocytosis refers to the response of astrocytes to different insults to the nervous system, whereas astrocytopathy indicates hypertrophy, atrophy/degeneration and loss of function and pathological remodeling occurring as a primary cause of a disease or as a factor contributing to the development and progression of a particular disease. Reactive astrocytosis secondary to neuron loss and astrocytopathy due to intrinsic alterations of astrocytes occur in neurodegenerative diseases, overlap each other, and, together with astrocyte senescence, contribute to disease-specific astrogliopathy in aging and neurodegenerative diseases with abnormal protein aggregates in old age. In addition to the well-known increase in glial fibrillary acidic protein and other proteins in reactive astrocytes, astrocytopathy is evidenced by deposition of abnormal proteins such as β-amyloid, hyper-phosphorylated tau, abnormal α-synuclein, mutated huntingtin, phosphorylated TDP-43 and mutated SOD1, and PrPres , in Alzheimer's disease, tauopathies, Lewy body diseases, Huntington's disease, amyotrophic lateral sclerosis and Creutzfeldt-Jakob disease, respectively. Astrocytopathy in these diseases can also be manifested by impaired glutamate transport; abnormal metabolism and release of neurotransmitters; altered potassium, calcium and water channels resulting in abnormal ion and water homeostasis; abnormal glucose metabolism; abnormal lipid and, particularly, cholesterol metabolism; increased oxidative damage and altered oxidative stress responses; increased production of cytokines and mediators of the inflammatory response; altered expression of connexins with deterioration of cell-to-cell networks and transfer of gliotransmitters; and worsening function of the blood brain barrier, among others. Increased knowledge of these aspects will permit a better understanding of brain aging and neurodegenerative diseases in old age as complex disorders in which neurons are not the only players.
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Affiliation(s)
- Isidro Ferrer
- Department of Pathology and Experimental TherapeuticsUniversity of BarcelonaBarcelonaSpain
- Institute of NeuropathologyPathologic Anatomy Service, Bellvitge University Hospital, IDIBELL, Hospitalet de LlobregatBarcelonaSpain
- Institute of NeurosciencesUniversity of BarcelonaBarcelonaSpain
- Biomedical Network Research Center on Neurodegenerative Diseases (CIBERNED), Institute Carlos IIIMadridSpain
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Niedergang F, Gasman S, Vitale N, Desnos C, Lamaze C. Meeting after meeting: 20 years of discoveries by the members of the Exocytosis-Endocytosis Club. Biol Cell 2017; 109:339-353. [DOI: 10.1111/boc.201700026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/24/2017] [Accepted: 07/24/2017] [Indexed: 11/29/2022]
Affiliation(s)
- Florence Niedergang
- Institut National de la Santé et de la Recherche Médicale (INSERM); U1016 Institut Cochin Paris France
- Centre National de la Recherche Scientifique (CNRS); UMR 8104 Paris France
- Université Paris Descartes, Sorbonne Paris Cité; Paris France
| | - Stéphane Gasman
- Institut des Neurosciences Cellulaires et Intégratives; CNRS UPR3212; Université de Strasbourg; France
- INSERM; 75654 Paris Cedex 13 France
| | - Nicolas Vitale
- Institut des Neurosciences Cellulaires et Intégratives; CNRS UPR3212; Université de Strasbourg; France
- INSERM; 75654 Paris Cedex 13 France
| | - Claire Desnos
- Université Paris Descartes, Sorbonne Paris Cité; Paris France
- CNRS; UMR 8250 Paris France
| | - Christophe Lamaze
- Institut Curie - Centre de Recherche; PSL Research University; Membrane Dynamics and Mechanics of Intracellular Signaling Laboratory; Paris France
- CNRS; UMR 3666 Paris France
- INSERM; U1143 Paris France
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57
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Victoria GS, Zurzolo C. The spread of prion-like proteins by lysosomes and tunneling nanotubes: Implications for neurodegenerative diseases. J Cell Biol 2017; 216:2633-2644. [PMID: 28724527 PMCID: PMC5584166 DOI: 10.1083/jcb.201701047] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 06/03/2017] [Accepted: 07/05/2017] [Indexed: 11/22/2022] Open
Abstract
Victoria and Zurzolo discuss current evidence for the emerging role of lysosomal damage and tunneling nanotubes in the intercellular propagation of prion and prion-like proteins in neurodegenerative disease. Progression of pathology in neurodegenerative diseases is hypothesized to be a non–cell-autonomous process that may be mediated by the productive spreading of prion-like protein aggregates from a “donor cell” that is the source of misfolded aggregates to an “acceptor cell” in which misfolding is propagated by conversion of the normal protein. Although the proteins involved in the various diseases are unrelated, common pathways appear to be used for their intercellular propagation and spreading. Here, we summarize recent evidence of the molecular mechanisms relevant for the intercellular trafficking of protein aggregates involved in prion, Alzheimer’s, Huntington’s, and Parkinson’s diseases. We focus in particular on the common roles that lysosomes and tunneling nanotubes play in the formation and spreading of prion-like assemblies.
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Affiliation(s)
| | - Chiara Zurzolo
- Unité de Trafic Membranaire et Pathogénèse, Institut Pasteur, Paris, France
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58
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Nawaz M, Fatima F. Extracellular Vesicles, Tunneling Nanotubes, and Cellular Interplay: Synergies and Missing Links. Front Mol Biosci 2017; 4:50. [PMID: 28770210 PMCID: PMC5513920 DOI: 10.3389/fmolb.2017.00050] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 07/03/2017] [Indexed: 12/15/2022] Open
Abstract
The process of intercellular communication seems to have been a highly conserved evolutionary process. Higher eukaryotes use several means of intercellular communication to address both the changing physiological demands of the body and to fight against diseases. In recent years, there has been an increasing interest in understanding how cell-derived nanovesicles, known as extracellular vesicles (EVs), can function as normal paracrine mediators of intercellular communication, but can also elicit disease progression and may be used for innovative therapies. Over the last decade, a large body of evidence has accumulated to show that cells use cytoplasmic extensions comprising open-ended channels called tunneling nanotubes (TNTs) to connect cells at a long distance and facilitate the exchange of cytoplasmic material. TNTs are a different means of communication to classical gap junctions or cell fusions; since they are characterized by long distance bridging that transfers cytoplasmic organelles and intracellular vesicles between cells and represent the process of heteroplasmy. The role of EVs in cell communication is relatively well-understood, but how TNTs fit into this process is just emerging. The aim of this review is to describe the relationship between TNTs and EVs, and to discuss the synergies between these two crucial processes in the context of normal cellular cross-talk, physiological roles, modulation of immune responses, development of diseases, and their combinatory effects in tissue repair. At the present time this review appears to be the first summary of the implications of the overlapping roles of TNTs and EVs. We believe that a better appreciation of these parallel processes will improve our understanding on how these nanoscale conduits can be utilized as novel tools for targeted therapies.
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Affiliation(s)
- Muhammad Nawaz
- Department of Pathology and Forensic Medicine, Ribeirao Preto Medical School, University of São PauloSão Paulo, Brazil.,Department of Rheumatology and Inflammation Research, Sahlgrenska Academy, University of GothenburgGothenburg, Sweden
| | - Farah Fatima
- Department of Pathology and Forensic Medicine, Ribeirao Preto Medical School, University of São PauloSão Paulo, Brazil
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59
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Cell Connections by Tunneling Nanotubes: Effects of Mitochondrial Trafficking on Target Cell Metabolism, Homeostasis, and Response to Therapy. Stem Cells Int 2017; 2017:6917941. [PMID: 28659978 PMCID: PMC5474251 DOI: 10.1155/2017/6917941] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 03/21/2017] [Accepted: 03/30/2017] [Indexed: 01/16/2023] Open
Abstract
Intercellular communications play a major role in tissue homeostasis and responses to external cues. Novel structures for this communication have recently been described. These tunneling nanotubes (TNTs) consist of thin-extended membrane protrusions that connect cells together. TNTs allow the cell-to-cell transfer of various cellular components, including proteins, RNAs, viruses, and organelles, such as mitochondria. Mesenchymal stem cells (MSCs) are both naturally present and recruited to many different tissues where their interaction with resident cells via secreted factors has been largely documented. Their immunosuppressive and repairing capacities constitute the basis for many current clinical trials. MSCs recruited to the tumor microenvironment also play an important role in tumor progression and resistance to therapy. MSCs are now the focus of intense scrutiny due to their capacity to form TNTs and transfer mitochondria to target cells, either in normal physiological or in pathological conditions, leading to changes in cell energy metabolism and functions, as described in this review.
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60
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Rayman JB, Kandel ER. TIA-1 Is a Functional Prion-Like Protein. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a030718. [PMID: 28003185 DOI: 10.1101/cshperspect.a030718] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Prions are self-propagating protein conformations that are traditionally regarded as agents of neurodegenerative disease in animals. However, it has become evident that prion-like aggregation of endogenous proteins can also occur under normal physiological conditions (e.g., during memory storage or activation of the immune response). In this review, we focus on the functional prion-related protein TIA-1, an RNA-binding protein that is involved in multiple aspects of RNA metabolism but is best understood in terms of its role in stress granule assembly during the cellular stress response. We propose that stress granule formation provides a useful conceptual framework with which to address the positive role of TIA-1 prion-like aggregation. Elucidating the function of TIA-1 prion-like aggregation will advance our understanding of how prion-based molecular switches are used in normal physiological settings.
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Affiliation(s)
- Joseph B Rayman
- Department of Neuroscience, College of Physicians and Surgeons of Columbia University, New York, New York 10032
| | - Eric R Kandel
- Department of Neuroscience, College of Physicians and Surgeons of Columbia University, New York, New York 10032.,Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York, New York 10032.,Howard Hughes Medical Institute at Columbia University, New York, New York 10032.,Zuckerman Mind Brain Behavior Institute, Columbia University, New York, New York 10032.,Kavli Institute for Brain Science, Columbia University, New York, New York 10032
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61
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Age and Environment Influences on Mouse Prion Disease Progression: Behavioral Changes and Morphometry and Stereology of Hippocampal Astrocytes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:4504925. [PMID: 28243355 PMCID: PMC5294381 DOI: 10.1155/2017/4504925] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/21/2016] [Accepted: 11/24/2016] [Indexed: 01/05/2023]
Abstract
Because enriched environment (EE) and exercise increase and aging decreases immune response, we hypothesized that environmental enrichment and aging will, respectively, delay and increase prion disease progression. Mice dorsal striatum received bilateral stereotaxic intracerebral injections of normal or ME7 prion infected mouse brain homogenates. After behavior analysis, animals were euthanized and their brains processed for astrocyte GFAP immunolabeling. Our analysis related to the environmental influence are limited to young adult mice, whereas age influence refers to aged mice raised on standard cages. Burrowing activity began to reduce in ME7-SE two weeks before ME7-EE, while no changes were apparent in ME7 aged mice (ME7-A). Object placement recognition was impaired in ME7-SE, NBH-A, and ME7-A but normal in all other groups. Object identity recognition was impaired in ME7-A. Cluster analysis revealed two morphological families of astrocytes in NBH-SE animals, three in NBH-A and ME7-A, and four in NBH-EE, ME7-SE, and ME7-EE. As compared with control groups, astrocytes from DG and CA3 prion-diseased animals show significant numerical and morphological differences and environmental enrichment did not reverse these changes but induced different morphological changes in GFAP+ hippocampal astroglia. We suggest that environmental enrichment and aging delayed hippocampal-dependent behavioral and neuropathological signs of disease progression.
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62
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Delage E, Cervantes DC, Pénard E, Schmitt C, Syan S, Disanza A, Scita G, Zurzolo C. Differential identity of Filopodia and Tunneling Nanotubes revealed by the opposite functions of actin regulatory complexes. Sci Rep 2016; 6:39632. [PMID: 28008977 PMCID: PMC5180355 DOI: 10.1038/srep39632] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 11/25/2016] [Indexed: 11/09/2022] Open
Abstract
Tunneling Nanotubes (TNTs) are actin enriched filopodia-like protrusions that play a pivotal role in long-range intercellular communication. Different pathogens use TNT-like structures as "freeways" to propagate across cells. TNTs are also implicated in cancer and neurodegenerative diseases, making them promising therapeutic targets. Understanding the mechanism of their formation, and their relation with filopodia is of fundamental importance to uncover their physiological function, particularly since filopodia, differently from TNTs, are not able to mediate transfer of cargo between distant cells. Here we studied different regulatory complexes of actin, which play a role in the formation of both these structures. We demonstrate that the filopodia-promoting CDC42/IRSp53/VASP network negatively regulates TNT formation and impairs TNT-mediated intercellular vesicle transfer. Conversely, elevation of Eps8, an actin regulatory protein that inhibits the extension of filopodia in neurons, increases TNT formation. Notably, Eps8-mediated TNT induction requires Eps8 bundling but not its capping activity. Thus, despite their structural similarities, filopodia and TNTs form through distinct molecular mechanisms. Our results further suggest that a switch in the molecular composition in common actin regulatory complexes is critical in driving the formation of either type of membrane protrusion.
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Affiliation(s)
- Elise Delage
- Unité Trafic Membranaire et Pathogenèse, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
| | - Diégo Cordero Cervantes
- Unité Trafic Membranaire et Pathogenèse, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
| | - Esthel Pénard
- Unité Trafic Membranaire et Pathogenèse, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
| | - Christine Schmitt
- Ultrapole, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
| | - Sylvie Syan
- Unité Trafic Membranaire et Pathogenèse, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
| | - Andrea Disanza
- FIRC Institute of Molecular Oncology, 20139 Milan, Italy
| | - Giorgio Scita
- FIRC Institute of Molecular Oncology, 20139 Milan, Italy.,Dipartimento di Scienze della Salute, Università degli Studi di Milano, 20122 Milan, Italy
| | - Chiara Zurzolo
- Unité Trafic Membranaire et Pathogenèse, Institut Pasteur, 25-28 Rue du Docteur Roux, 75724 Paris CEDEX 15, France
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