501
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Dujardin S, Colin M, Buée L. Invited review: Animal models of tauopathies and their implications for research/translation into the clinic. Neuropathol Appl Neurobiol 2015; 41:59-80. [DOI: 10.1111/nan.12200] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 11/23/2014] [Indexed: 02/01/2023]
Affiliation(s)
- Simon Dujardin
- Inserm, UMR1172 Jean-Pierre Aubert Research Centre; Lille France
- Faculté de Médecine; Université de Lille; France
- Memory Clinic; CHRU; Lille France
| | - Morvane Colin
- Inserm, UMR1172 Jean-Pierre Aubert Research Centre; Lille France
- Faculté de Médecine; Université de Lille; France
- Memory Clinic; CHRU; Lille France
| | - Luc Buée
- Inserm, UMR1172 Jean-Pierre Aubert Research Centre; Lille France
- Faculté de Médecine; Université de Lille; France
- Memory Clinic; CHRU; Lille France
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502
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Congdon EE, Krishnaswamy S, Sigurdsson EM. Harnessing the immune system for treatment and detection of tau pathology. J Alzheimers Dis 2015; 40 Suppl 1:S113-21. [PMID: 24603943 DOI: 10.3233/jad-132435] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The tau protein is an attractive target for therapy and diagnosis. We started a tau immunotherapy program about 13 years ago and have since demonstrated that active and passive immunotherapies diminish tau pathology and improve function, including cognition, in different mouse models. These findings have been confirmed and extended by several groups. We routinely detect neuronal, and to a lesser extent microglial, antibody uptake correlating with tau pathology. Antibodies bind tau aggregates in the endosomal/lysosomal system, enhancing clearance presumably by promoting their disassembly. Extracellular clearance has recently been shown by others, using antibodies that apparently are not internalized. As most pathological tau is neuronal, intracellular targeting may be more efficacious. However, extracellular tau may be more accessible to antibodies, with tau-antibody complexes a target for microglial phagocytosis. The extent of involvement of each pathway may depend on numerous factors including antibody properties, degree of pathology, and experimental model. On the imaging front, multiple tau ligands derived from β-sheet dyes have been developed by several groups, some with promising results in clinical PET tests. Postmortem analysis should clarify their tau specificity, as in theory and based on histological staining, those are likely to have some affinity for various amyloids. We are developing antibody-derived tau probes that should be more specific, and have in mouse models shown in vivo detection and binding to pathological tau after peripheral injection. These are exciting times for research on tau therapies and diagnostic agents that hopefully can be applied to humans in the near future.
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Affiliation(s)
- Erin E Congdon
- Departments of Neuroscience and Physiology, New York University School of Medicine, NY, USA
| | | | - Einar M Sigurdsson
- Departments of Neuroscience and Physiology, New York University School of Medicine, NY, USA Departments of Psychiatry, New York University School of Medicine, NY, USA
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503
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Spreading of pathology in neurodegenerative diseases: a focus on human studies. Nat Rev Neurosci 2015; 16:109-20. [PMID: 25588378 DOI: 10.1038/nrn3887] [Citation(s) in RCA: 531] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The progression of many neurodegenerative diseases is thought to be driven by the template-directed misfolding, seeded aggregation and cell-cell transmission of characteristic disease-related proteins, leading to the sequential dissemination of pathological protein aggregates. Recent evidence strongly suggests that the anatomical connections made by neurons - in addition to the intrinsic characteristics of neurons, such as morphology and gene expression profile - determine whether they are vulnerable to degeneration in these disorders. Notably, this common pathogenic principle opens up opportunities for pursuing novel targets for therapeutic interventions for these neurodegenerative disorders. We review recent evidence that supports the notion of neuron-neuron protein propagation, with a focus on neuropathological and positron emission tomography imaging studies in humans.
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504
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The Ubiquitin-Proteasome System and Molecular Chaperone Deregulation in Alzheimer's Disease. Mol Neurobiol 2015; 53:905-931. [PMID: 25561438 DOI: 10.1007/s12035-014-9063-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/09/2014] [Indexed: 12/18/2022]
Abstract
One of the shared hallmarks of neurodegenerative diseases is the accumulation of misfolded proteins. Therefore, it is suspected that normal proteostasis is crucial for neuronal survival in the brain and that the malfunction of this mechanism may be the underlying cause of neurodegenerative diseases. The accumulation of amyloid plaques (APs) composed of amyloid-beta peptide (Aβ) aggregates and neurofibrillary tangles (NFTs) composed of misfolded Tau proteins are the defining pathological markers of Alzheimer's disease (AD). The accumulation of these proteins indicates a faulty protein quality control in the AD brain. An impaired ubiquitin-proteasome system (UPS) could lead to negative consequences for protein regulation, including loss of function. Another pivotal mechanism for the prevention of misfolded protein accumulation is the utilization of molecular chaperones. Molecular chaperones, such as heat shock proteins (HSPs) and FK506-binding proteins (FKBPs), are highly involved in protein regulation to ensure proper folding and normal function. In this review, we elaborate on the molecular basis of AD pathophysiology using recent data, with a particular focus on the role of the UPS and molecular chaperones as the defensive mechanism against misfolded proteins that have prion-like properties. In addition, we propose a rational therapy approach based on this mechanism.
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505
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Morales R, Callegari K, Soto C. Prion-like features of misfolded Aβ and tau aggregates. Virus Res 2015; 207:106-12. [PMID: 25575736 DOI: 10.1016/j.virusres.2014.12.031] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/11/2014] [Accepted: 12/29/2014] [Indexed: 02/07/2023]
Abstract
Recent findings have shown that several misfolded proteins can transmit disease pathogenesis in a prion-like manner by transferring their conformational properties to normally folded units. However, the extent by which these molecule-to-molecule or cell-to-cell spreading processes reflect the entire prion behavior is now subject of controversy, especially due to the lack of epidemiological data supporting inter-individual transmission of non-prion protein misfolding diseases. Nevertheless, extensive research has shown that several of the typical characteristics of prions can be observed for Aβ and tau aggregates when administered in animal models. In this article we review recent studies describing the prion-like features of both proteins, highlighting the similarities with bona fide prions in terms of inter-individual transmission, their strain-like conformational diversity, and the transmission of misfolded aggregates by different routes of administration.
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Affiliation(s)
- Rodrigo Morales
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, 6431 Fannin Street, Houston, TX 77030, United States.
| | - Keri Callegari
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, 6431 Fannin Street, Houston, TX 77030, United States.
| | - Claudio Soto
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, 6431 Fannin Street, Houston, TX 77030, United States.
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506
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Ren Y, Sahara N, Giasson B, Lewis J. Tauopathy Mouse Models. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00055-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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507
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Crary JF, Trojanowski JQ, Schneider JA, Abisambra JF, Abner EL, Alafuzoff I, Arnold SE, Attems J, Beach TG, Bigio EH, Cairns NJ, Dickson DW, Gearing M, Grinberg LT, Hof PR, Hyman BT, Jellinger K, Jicha GA, Kovacs GG, Knopman DS, Kofler J, Kukull WA, Mackenzie IR, Masliah E, McKee A, Montine TJ, Murray ME, Neltner JH, Santa-Maria I, Seeley WW, Serrano-Pozo A, Shelanski ML, Stein T, Takao M, Thal DR, Toledo JB, Troncoso JC, Vonsattel JP, White CL, Wisniewski T, Woltjer RL, Yamada M, Nelson PT. Primary age-related tauopathy (PART): a common pathology associated with human aging. Acta Neuropathol 2014; 128:755-66. [PMID: 25348064 DOI: 10.1007/s00401-014-1349-0] [Citation(s) in RCA: 979] [Impact Index Per Article: 97.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/26/2014] [Accepted: 09/28/2014] [Indexed: 01/31/2023]
Abstract
We recommend a new term, "primary age-related tauopathy" (PART), to describe a pathology that is commonly observed in the brains of aged individuals. Many autopsy studies have reported brains with neurofibrillary tangles (NFTs) that are indistinguishable from those of Alzheimer's disease (AD), in the absence of amyloid (Aβ) plaques. For these "NFT+/Aβ-" brains, for which formal criteria for AD neuropathologic changes are not met, the NFTs are mostly restricted to structures in the medial temporal lobe, basal forebrain, brainstem, and olfactory areas (bulb and cortex). Symptoms in persons with PART usually range from normal to amnestic cognitive changes, with only a minority exhibiting profound impairment. Because cognitive impairment is often mild, existing clinicopathologic designations, such as "tangle-only dementia" and "tangle-predominant senile dementia", are imprecise and not appropriate for most subjects. PART is almost universally detectable at autopsy among elderly individuals, yet this pathological process cannot be specifically identified pre-mortem at the present time. Improved biomarkers and tau imaging may enable diagnosis of PART in clinical settings in the future. Indeed, recent studies have identified a common biomarker profile consisting of temporal lobe atrophy and tauopathy without evidence of Aβ accumulation. For both researchers and clinicians, a revised nomenclature will raise awareness of this extremely common pathologic change while providing a conceptual foundation for future studies. Prior reports that have elucidated features of the pathologic entity we refer to as PART are discussed, and working neuropathological diagnostic criteria are proposed.
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508
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Stancu IC, Vasconcelos B, Terwel D, Dewachter I. Models of β-amyloid induced Tau-pathology: the long and "folded" road to understand the mechanism. Mol Neurodegener 2014; 9:51. [PMID: 25407337 PMCID: PMC4255655 DOI: 10.1186/1750-1326-9-51] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 10/14/2014] [Indexed: 02/28/2023] Open
Abstract
The amyloid cascade hypothesis has been the prevailing hypothesis in Alzheimer’s Disease research, although the final and most wanted proof i.e. fully successful anti-amyloid clinical trials in patients, is still lacking. This may require a better in depth understanding of the cascade. Particularly, the exact toxic forms of Aβ and Tau, the molecular link between them and their respective contributions to the disease process need to be identified in detail. Although the lack of final proof has raised substantial criticism on the hypothesis per se, accumulating experimental evidence in in vitro models, in vivo models and from biomarkers analysis in patients supports the amyloid cascade and particularly Aβ-induced Tau-pathology, which is the focus of this review. We here discuss available models that recapitulate Aβ-induced Tau-pathology and review some potential underlying mechanisms. The availability and diversity of these models that mimic the amyloid cascade partially or more complete, provide tools to study remaining questions, which are crucial for development of therapeutic strategies for Alzheimer’s Disease.
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Affiliation(s)
| | | | | | - Ilse Dewachter
- Catholic University of Louvain, Institute of Neuroscience, Alzheimer Dementia, Av, E, Mounier 53, Av, Hippocrate 54, B-1200 Brussels, Belgium.
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509
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Falcon B, Cavallini A, Angers R, Glover S, Murray TK, Barnham L, Jackson S, O'Neill MJ, Isaacs AM, Hutton ML, Szekeres PG, Goedert M, Bose S. Conformation determines the seeding potencies of native and recombinant Tau aggregates. J Biol Chem 2014; 290:1049-65. [PMID: 25406315 PMCID: PMC4294473 DOI: 10.1074/jbc.m114.589309] [Citation(s) in RCA: 193] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Intracellular Tau inclusions are a pathological hallmark of several neurodegenerative diseases, collectively known as the tauopathies. They include Alzheimer disease, tangle-only dementia, Pick disease, argyrophilic grain disease, chronic traumatic encephalopathy, progressive supranuclear palsy, and corticobasal degeneration. Tau pathology appears to spread through intercellular propagation, requiring the formation of assembled “prion-like” species. Several cell and animal models have been described that recapitulate aspects of this phenomenon. However, the molecular characteristics of seed-competent Tau remain unclear. Here, we have used a cell model to understand the relationships between Tau structure/phosphorylation and seeding by aggregated Tau species from the brains of mice transgenic for human mutant P301S Tau and full-length aggregated recombinant P301S Tau. Deletion of motifs 275VQIINK280 and 306VQIVYK311 abolished the seeding activity of recombinant full-length Tau, suggesting that its aggregation was necessary for seeding. We describe conformational differences between native and synthetic Tau aggregates that may account for the higher seeding activity of native assembled Tau. When added to aggregated Tau seeds from the brains of mice transgenic for P301S Tau, soluble recombinant Tau aggregated and acquired the molecular properties of aggregated Tau from transgenic mouse brain. We show that seeding is conferred by aggregated Tau that enters cells through macropinocytosis and seeds the assembly of endogenous Tau into filaments.
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Affiliation(s)
- Benjamin Falcon
- From the Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Annalisa Cavallini
- Eli Lilly and Co., Erl Wood Manor, Windlesham, Surrey GU20 6PH, United Kingdom, and
| | - Rachel Angers
- From the Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom, Eli Lilly and Co., Erl Wood Manor, Windlesham, Surrey GU20 6PH, United Kingdom, and
| | - Sarah Glover
- Eli Lilly and Co., Erl Wood Manor, Windlesham, Surrey GU20 6PH, United Kingdom, and
| | - Tracey K Murray
- Eli Lilly and Co., Erl Wood Manor, Windlesham, Surrey GU20 6PH, United Kingdom, and
| | - Luanda Barnham
- Eli Lilly and Co., Erl Wood Manor, Windlesham, Surrey GU20 6PH, United Kingdom, and
| | - Samuel Jackson
- Eli Lilly and Co., Erl Wood Manor, Windlesham, Surrey GU20 6PH, United Kingdom, and
| | - Michael J O'Neill
- Eli Lilly and Co., Erl Wood Manor, Windlesham, Surrey GU20 6PH, United Kingdom, and
| | - Adrian M Isaacs
- the UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Michael L Hutton
- Eli Lilly and Co., Erl Wood Manor, Windlesham, Surrey GU20 6PH, United Kingdom, and
| | - Philip G Szekeres
- Eli Lilly and Co., Erl Wood Manor, Windlesham, Surrey GU20 6PH, United Kingdom, and
| | - Michel Goedert
- From the Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom,
| | - Suchira Bose
- Eli Lilly and Co., Erl Wood Manor, Windlesham, Surrey GU20 6PH, United Kingdom, and
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510
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Lang AE. Clinical heterogeneity in progressive supranuclear palsy: challenges to diagnosis, pathogenesis and future therapies. Mov Disord 2014; 29:1707-9. [PMID: 25384577 DOI: 10.1002/mds.26105] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 11/05/2014] [Indexed: 11/08/2022] Open
Affiliation(s)
- Anthony E Lang
- Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital and the University of Toronto
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511
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Goedert M, Falcon B, Clavaguera F, Tolnay M. Prion-like mechanisms in the pathogenesis of tauopathies and synucleinopathies. Curr Neurol Neurosci Rep 2014; 14:495. [PMID: 25218483 DOI: 10.1007/s11910-014-0495-z] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease, are characterized by the abnormal aggregation of a small number of intracellular proteins, with tau and α-synuclein being the most commonly affected. Until recently, the events leading to aggregate formation were believed to be entirely cell-autonomous, with protein misfolding occurring independently in many cells. It is now believed that protein aggregates form in a small number of brain cells, from which they propagate intercellularly through templated recruitment, reminiscent of the mechanisms by which prions spread through the nervous system.
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Affiliation(s)
- Michel Goedert
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK,
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512
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Magnusson K, Simon R, Sjölander D, Sigurdson CJ, Hammarström P, Nilsson KPR. Multimodal fluorescence microscopy of prion strain specific PrP deposits stained by thiophene-based amyloid ligands. Prion 2014; 8:319-29. [PMID: 25495506 PMCID: PMC4601348 DOI: 10.4161/pri.29239] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The disease-associated prion protein (PrP) forms aggregates which vary in structural conformation yet share an identical primary sequence. These variations in PrP conformation are believed to manifest in prion strains exhibiting distinctly different periods of disease incubation as well as regionally specific aggregate deposition within the brain. The anionic luminescent conjugated polythiophene (LCP), polythiophene acetic acid (PTAA) has previously been used to distinguish PrP deposits associated with distinct mouse adapted strains via distinct fluorescence emission profiles from the dye. Here, we employed PTAA and 3 structurally related chemically defined luminescent conjugated oligothiophenes (LCOs) to stain brain tissue sections from mice inoculated with 2 distinct prion strains. Our results showed that in addition to emission spectra, excitation, and fluorescence lifetime imaging microscopy (FLIM) can fruitfully be assessed for optical distinction of PrP deposits associated with distinct prion strains. Our findings support the theory that alterations in LCP/LCO fluorescence are due to distinct conformational restriction of the thiophene backbone upon interaction with PrP aggregates associated with distinct prion strains. We foresee that LCP and LCO staining in combination with multimodal fluorescence microscopy might aid in detecting structural differences among discrete protein aggregates and in linking protein conformational features with disease phenotypes for a variety of neurodegenerative proteinopathies.
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Affiliation(s)
- Karin Magnusson
- a Department of Chemistry ; Linköping University ; Linköping , Sweden
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513
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Alpha-synuclein and tau: teammates in neurodegeneration? Mol Neurodegener 2014; 9:43. [PMID: 25352339 PMCID: PMC4230508 DOI: 10.1186/1750-1326-9-43] [Citation(s) in RCA: 184] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 10/16/2014] [Indexed: 11/25/2022] Open
Abstract
The accumulation of α-synuclein aggregates is the hallmark of Parkinson’s disease, and more generally of synucleinopathies. The accumulation of tau aggregates however is classically found in the brains of patients with dementia, and this type of neuropathological feature specifically defines the tauopathies. Nevertheless, in numerous cases α-synuclein positive inclusions are also described in tauopathies and vice versa, suggesting a co-existence or crosstalk of these proteinopathies. Interestingly, α-synuclein and tau share striking common characteristics suggesting that they may work in concord. Tau and α-synuclein are both partially unfolded proteins that can form toxic oligomers and abnormal intracellular aggregates under pathological conditions. Furthermore, mutations in either are responsible for severe dominant familial neurodegeneration. Moreover, tau and α-synuclein appear to promote the fibrillization and solubility of each other in vitro and in vivo. This suggests that interactions between tau and α-synuclein form a deleterious feed-forward loop essential for the development and spreading of neurodegeneration. Here, we review the recent literature with respect to elucidating the possible links between α-synuclein and tau.
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514
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Is there a risk of prion-like disease transmission by Alzheimer- or Parkinson-associated protein particles? Acta Neuropathol 2014; 128:463-76. [PMID: 25073522 PMCID: PMC4159603 DOI: 10.1007/s00401-014-1324-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 07/18/2014] [Accepted: 07/18/2014] [Indexed: 12/25/2022]
Abstract
The misfolding and aggregation of endogenous proteins in the central nervous system is a neuropathological hallmark of Alzheimer's disease (AD), Parkinson's disease (PD), as well as prion diseases. A molecular mechanism referred to as "nucleation-dependent aggregation" is thought to underlie this neuropathological phenomenon. According to this concept, disease-associated protein particles act as nuclei, or seeds, that recruit cellular proteins and incorporate them, in a misfolded form, into their growing aggregate structure. Experimental studies have shown that the aggregation of the AD-associated proteins amyloid-β (Aβ) and tau, and of the PD-associated protein α-synuclein, can be stimulated in laboratory animal models by intracerebral (i.c.) injection of inocula containing aggregated species of the respective proteins. This has raised the question of whether AD or PD can be transmitted, like certain human prion diseases, between individuals by self-propagating protein particles potentially present on medical instruments or in blood or blood products. While the i.c. injection of inocula containing AD- or PD-associated protein aggregates was found to cause neuronal damage and clinical abnormalities (e.g., motor impairments) in some animal models, none of the studies published so far provided evidence for a transmission of severe or even fatal disease. In addition, available epidemiological data do not indicate a transmissibility of AD or PD between humans. The findings published so far on the effects of experimentally transmitted AD- or PD-associated protein seeds do not suggest specific precautionary measures in the context of hemotherapy, but call for vigilance in transfusion medicine and other medical areas.
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515
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Abstract
Transcellular propagation of protein aggregates, or proteopathic seeds, may drive the progression of neurodegenerative diseases in a prion-like manner. In tauopathies such as Alzheimer's disease, this model predicts that tau seeds propagate pathology through the brain via cell-cell transfer in neural networks. The critical role of tau seeding activity is untested, however. It is unknown whether seeding anticipates and correlates with subsequent development of pathology as predicted for a causal agent. One major limitation has been the lack of a robust assay to measure proteopathic seeding activity in biological specimens. We engineered an ultrasensitive, specific, and facile FRET-based flow cytometry biosensor assay based on expression of tau or synuclein fusions to CFP and YFP, and confirmed its sensitivity and specificity to tau (∼ 300 fM) and synuclein (∼ 300 pM) fibrils. This assay readily discriminates Alzheimer's disease vs. Huntington's disease and aged control brains. We then carried out a detailed time-course study in P301S tauopathy mice, comparing seeding activity versus histological markers of tau pathology, including MC1, AT8, PG5, and Thioflavin S. We detected robust seeding activity at 1.5 mo, >1 mo before the earliest histopathological stain. Proteopathic tau seeding is thus an early and robust marker of tauopathy, suggesting a proximal role for tau seeds in neurodegeneration.
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516
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Dai CL, Chen X, Kazim SF, Liu F, Gong CX, Grundke-Iqbal I, Iqbal K. Passive immunization targeting the N-terminal projection domain of tau decreases tau pathology and improves cognition in a transgenic mouse model of Alzheimer disease and tauopathies. J Neural Transm (Vienna) 2014; 122:607-17. [PMID: 25233799 DOI: 10.1007/s00702-014-1315-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 09/12/2014] [Indexed: 01/16/2023]
Abstract
Intraneuronal accumulation of abnormally hyperphosphorylated tau in the brain is a histopathological hallmark of Alzheimer's disease and a family of related neurodegenerative disorders collectively called tauopathies. At present there is no effective treatment available for these progressive neurodegenerative diseases which are clinically characterized by dementia in mid to old-age. Here we report the treatment of 14-17-months-old 3xTg-AD mice with tau antibodies 43D (tau 6-18) and 77E9 (tau 184-195) to the N-terminal projection domain of tau or mouse IgG as a control by intraperitoneal injection once a week for 4 weeks, and the effects of the passive immunization on reduction of hyperphosphorylated tau, Aβ accumulation and cognitive performance in these animals. We found that treatment with tau antibodies 43D and 77E9 reduced total tau level, decreased tau hyperphosphorylated at Ser199, Ser202/Thr205 (AT8), Thr205, Ser262/356 (12E8), and Ser396/404 (PHF-1) sites, and a trend to reduce Aβ pathology. Most importantly, targeting N-terminal tau especially by 43D (tau 6-18) improved reference memory in the Morris water maze task in 3xTg-AD mice. We did not observe any abnormality in general physical characteristics of the treated animals with either of the two antibodies during the course of this study. Taken together, our studies demonstrate for the first time (1) that passive immunization targeting normal tau can effectively clear the hyperphosphorylated protein and possibly reduce Aβ pathology from the brain and (2) that targeting N-terminal projection domain of tau containing amino acid 6-18 is especially beneficial. Thus, targeting selective epitopes of N-terminal domain of tau may present a novel effective therapeutic opportunity for Alzheimer disease and other tauopathies.
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Affiliation(s)
- Chun-ling Dai
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY, 10314, USA
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517
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Meyer V, Dinkel PD, Rickman Hager E, Margittai M. Amplification of Tau fibrils from minute quantities of seeds. Biochemistry 2014; 53:5804-9. [PMID: 25153692 PMCID: PMC4165214 DOI: 10.1021/bi501050g] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
![]()
The
propagation of Tau pathology in Alzheimer’s disease
(AD) is thought to proceed through templated conversion of Tau protein
into fibrils and cell-to-cell transfer of elongation-competent seeds.
To investigate the efficiency of Tau conversion, we adapted the protein
misfolding cyclic amplification assay used for the conversion of prions.
Utilizing heparin as a cofactor and employing repetitive cycles of
shearing and growth, synthetic Tau fibrils and Tau fibrils in AD brain
extract are progressively amplified. Concurrently, self-nucleation
is suppressed. The results highlight breakage-induced replication
of Tau fibrils as a potential facilitator of disease spread.
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Affiliation(s)
- Virginia Meyer
- Department of Chemistry and Biochemistry, University of Denver , Denver, Colorado 80208, United States
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518
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Abstract
Sanders et al. (2014) demonstrate in this issue of Neuron that the natively unfolded protein tau can propagate indefinitely in distinct stable strains, therefore supporting the general idea that tau has prion-like properties, with implications for Alzheimer's disease and other tauopathies.
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Affiliation(s)
- Bradley T Hyman
- Neurology Service, Massachusetts General Hospital, 114 16(th) Street, Charlestown, MA 02129, USA.
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519
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Serial propagation of distinct strains of Aβ prions from Alzheimer's disease patients. Proc Natl Acad Sci U S A 2014; 111:10323-8. [PMID: 24982139 DOI: 10.1073/pnas.1408900111] [Citation(s) in RCA: 214] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
An increasing number of studies argues that self-propagating protein conformations (i.e., prions) feature in the pathogenesis of several common neurodegenerative diseases. Mounting evidence contends that aggregates of the amyloid-β (Aβ) peptide become self-propagating in Alzheimer's disease (AD) patients. An important characteristic of prions is their ability to replicate distinct strains, the biological information for which is enciphered within different conformations of protein aggregates. To investigate whether distinct strains of Aβ prions can be discerned in AD patients, we performed transmission studies in susceptible transgenic mice using brain homogenates from sporadic or heritable (Arctic and Swedish) AD cases. Mice inoculated with the Arctic AD sample exhibited a pathology that could be distinguished from mice inoculated with the Swedish or sporadic AD samples, which was judged by differential accumulation of Aβ isoforms and the morphology of cerebrovascular Aβ deposition. Unlike Swedish AD- or sporadic AD-inoculated animals, Arctic AD-inoculated mice, like Arctic AD patients, displayed a prominent Aβ38-containing cerebral amyloid angiopathy. The divergent transmission behavior of the Arctic AD sample compared with the Swedish and sporadic AD samples was maintained during second passage in mice, showing that Aβ strains are serially transmissible. We conclude that at least two distinct strains of Aβ prions can be discerned in the brains of AD patients and that strain fidelity was preserved on serial passage in mice. Our results provide a potential explanation for the clinical and pathological heterogeneity observed in AD patients.
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520
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Cicchetti F, Lacroix S, Cisbani G, Vallières N, Saint-Pierre M, St-Amour I, Tolouei R, Skepper JN, Hauser RA, Mantovani D, Barker RA, Freeman TB. Mutant huntingtin is present in neuronal grafts in huntington disease patients. Ann Neurol 2014; 76:31-42. [DOI: 10.1002/ana.24174] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 04/29/2014] [Accepted: 04/29/2014] [Indexed: 12/13/2022]
Affiliation(s)
- Francesca Cicchetti
- Centre Hospitalier Universitaire de Québec Research Center
- Departments of Psychiatry and Neurosciences
| | - Steve Lacroix
- Centre Hospitalier Universitaire de Québec Research Center
- Molecular Medicine, Laval University; Quebec City Quebec Canada
| | - Giulia Cisbani
- Centre Hospitalier Universitaire de Québec Research Center
| | | | | | | | - Ranna Tolouei
- Biomaterials and Bioengineering Laboratory; Saint-François d'Assise Hospital
- Department of Mining Engineering, Metallurgy, and Materials; Laval University; Quebec City Quebec Canada
| | - Jeremy N. Skepper
- Cambridge Advanced Imaging Centre; University of Cambridge; Cambridge United Kingdom
| | - Robert A. Hauser
- Departments of Neurology, Pharmacology, and Experimental Therapeutics; Parkinson's Disease and Movement Disorders National Parkinson's Foundation Center of Excellence, University of South Florida; Tampa Florida
| | - Diego Mantovani
- Biomaterials and Bioengineering Laboratory; Saint-François d'Assise Hospital
- Department of Mining Engineering, Metallurgy, and Materials; Laval University; Quebec City Quebec Canada
| | - Roger A. Barker
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences; University of Cambridge; Cambridge United Kingdom
| | - Thomas B. Freeman
- Department of Neurosurgery and Brain Repair
- Center of Excellence for Aging and Brain Repair; University of South Florida; Tampa Florida
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521
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Cook C, Stankowski JN, Carlomagno Y, Stetler C, Petrucelli L. Acetylation: a new key to unlock tau's role in neurodegeneration. ALZHEIMERS RESEARCH & THERAPY 2014; 6:29. [PMID: 25031639 PMCID: PMC4075151 DOI: 10.1186/alzrt259] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The identification of tau protein as a major constituent of neurofibrillary tangles spurred considerable effort devoted to identifying and validating pathways through which therapeutics may alleviate tau burden in Alzheimer's disease and related tauopathies, including chronic traumatic encephalopathy associated with sport- and military-related injuries. Most tau-based therapeutic strategies have previously focused on modulating tau phosphorylation, given that tau species present within neurofibrillary tangles are hyperphosphorylated on a number of different residues. However, the recent discovery that tau is modified by acetylation necessitates additional research to provide greater mechanistic insight into the spectrum of physiological consequences of tau acetylation, which may hold promise as a novel therapeutic target. In this review, we discuss recent findings evaluating tau acetylation in the context of previously accepted notions regarding tau biology and pathophysiology. We also examine the evidence demonstrating the neuroprotective and beneficial consequences of inhibiting histone deacetylase (HDAC)6, a tau deacetylase, including its effect on microtubule stabilization. We also discuss the rationale for pharmacologically modulating HDAC6 in tau-based pathologies as a novel therapeutic strategy.
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Affiliation(s)
- Casey Cook
- Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | | | - Yari Carlomagno
- Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA
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522
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Watts JC, Prusiner SB. Mouse models for studying the formation and propagation of prions. J Biol Chem 2014; 289:19841-9. [PMID: 24860095 DOI: 10.1074/jbc.r114.550707] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Prions are self-propagating protein conformers that cause a variety of neurodegenerative disorders in humans and animals. Mouse models have played key roles in deciphering the biology of prions and in assessing candidate therapeutics. The development of transgenic mice that form prions spontaneously in the brain has advanced our understanding of sporadic and genetic prion diseases. Furthermore, the realization that many proteins can become prions has necessitated the development of mouse models for assessing the potential transmissibility of common neurodegenerative diseases. As the universe of prion diseases continues to expand, mouse models will remain crucial for interrogating these devastating illnesses.
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Affiliation(s)
- Joel C Watts
- From the Institute for Neurodegenerative Diseases and the Department of Neurology, University of California, San Francisco, California 94143
| | - Stanley B Prusiner
- From the Institute for Neurodegenerative Diseases and the Department of Neurology, University of California, San Francisco, California 94143
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523
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Sanders DW, Kaufman SK, DeVos SL, Sharma AM, Mirbaha H, Li A, Barker SJ, Foley AC, Thorpe JR, Serpell LC, Miller TM, Grinberg LT, Seeley WW, Diamond MI. Distinct tau prion strains propagate in cells and mice and define different tauopathies. Neuron 2014; 82:1271-88. [PMID: 24857020 DOI: 10.1016/j.neuron.2014.04.047] [Citation(s) in RCA: 693] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2014] [Indexed: 12/13/2022]
Abstract
Prion-like propagation of tau aggregation might underlie the stereotyped progression of neurodegenerative tauopathies. True prions stably maintain unique conformations ("strains") in vivo that link structure to patterns of pathology. We now find that tau meets this criterion. Stably expressed tau repeat domain indefinitely propagates distinct amyloid conformations in a clonal fashion in culture. Reintroduction of tau from these lines into naive cells reestablishes identical clones. We produced two strains in vitro that induce distinct pathologies in vivo as determined by successive inoculations into three generations of transgenic mice. Immunopurified tau from these mice recreates the original strains in culture. We used the cell system to isolate tau strains from 29 patients with 5 different tauopathies, finding that different diseases are associated with different sets of strains. Tau thus demonstrates essential characteristics of a prion. This might explain the phenotypic diversity of tauopathies and could enable more effective diagnosis and therapy.
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Affiliation(s)
- David W Sanders
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63105, USA
| | - Sarah K Kaufman
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63105, USA
| | - Sarah L DeVos
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63105, USA
| | - Apurwa M Sharma
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63105, USA
| | - Hilda Mirbaha
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63105, USA
| | - Aimin Li
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63105, USA
| | - Scarlett J Barker
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63105, USA
| | - Alex C Foley
- School of Life Sciences, University of Sussex, Falmer BN1 9QG, UK
| | - Julian R Thorpe
- School of Life Sciences, University of Sussex, Falmer BN1 9QG, UK
| | - Louise C Serpell
- School of Life Sciences, University of Sussex, Falmer BN1 9QG, UK
| | - Timothy M Miller
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63105, USA
| | - Lea T Grinberg
- Department of Neurology and Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - William W Seeley
- Department of Neurology and Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Marc I Diamond
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63105, USA.
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524
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A novel in vivo model of tau propagation with rapid and progressive neurofibrillary tangle pathology: the pattern of spread is determined by connectivity, not proximity. Acta Neuropathol 2014; 127:667-83. [PMID: 24531916 PMCID: PMC4252866 DOI: 10.1007/s00401-014-1254-6] [Citation(s) in RCA: 345] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 01/28/2014] [Accepted: 01/30/2014] [Indexed: 12/16/2022]
Abstract
Intracellular inclusions composed of hyperphosphorylated filamentous tau are a hallmark of Alzheimer’s disease, progressive supranuclear palsy, Pick’s disease and other sporadic neurodegenerative tauopathies. Recent in vitro and in vivo studies have shown that tau aggregates do not only seed further tau aggregation within neurons, but can also spread to neighbouring cells and functionally connected brain regions. This process is referred to as ‘tau propagation’ and may explain the stereotypic progression of tau pathology in the brains of Alzheimer’s disease patients. Here, we describe a novel in vivo model of tau propagation using human P301S tau transgenic mice infused unilaterally with brain extract containing tau aggregates. Infusion-related neurofibrillary tangle pathology was first observed 2 weeks post-infusion and increased in a stereotypic, time-dependent manner. Contralateral and anterior/posterior spread of tau pathology was also evident in nuclei with strong synaptic connections (efferent and afferent) to the site of infusion, indicating that spread was dependent on synaptic connectivity rather than spatial proximity. This notion was further supported by infusion-related tau pathology in white matter tracts that interconnect these regions. The rapid and robust propagation of tau pathology in this model will be valuable for both basic research and the drug discovery process.
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525
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Ghaemmaghami S, Russo M, Renslo AR. Successes and challenges in phenotype-based lead discovery for prion diseases. J Med Chem 2014; 57:6919-29. [PMID: 24762293 PMCID: PMC4148153 DOI: 10.1021/jm5001425] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
![]()
Creutzfeldt–Jakob disease
(CJD) is a rare but invariably
fatal neurodegenerative disease caused by misfolding of an endogenous
protein into an alternative pathogenic conformation. The details of
protein misfolding and aggregation are not well understood nor are
the mechanism(s) by which the aggregated protein confers cellular
toxicity. While there is as yet no clear consensus about how best
to intervene therapeutically in CJD, prion infections can be propagated
in cell culture and in experimental animals, affording both in vitro
and in vivo models of disease. Here we review recent lead discovery
efforts for CJD, with a focus on our own efforts to optimize 2-aminothiazole
analogues for anti-prion potency in cells and for brain exposure in
mice. The compounds that emerged from this effort were found to be
efficacious in multiple animal models of prion disease even as they
revealed new challenges for the field, including the emergence of
resistant prion strains.
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Affiliation(s)
- Sina Ghaemmaghami
- Department of Biology, University of Rochester , 326 Hutchison Hall, Rochester, New York 14627, United States
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526
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Dal Prà I, Chiarini A, Gui L, Chakravarthy B, Pacchiana R, Gardenal E, Whitfield JF, Armato U. Do astrocytes collaborate with neurons in spreading the "infectious" aβ and Tau drivers of Alzheimer's disease? Neuroscientist 2014; 21:9-29. [PMID: 24740577 DOI: 10.1177/1073858414529828] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Evidence has begun emerging for the "contagious" and destructive Aβ42 (amyloid-beta42) oligomers and phosphorylated Tau oligomers as drivers of sporadic Alzheimer's disease (AD), which advances along a pathway starting from the brainstem or entorhinal cortex and leading to cognition-related upper cerebral cortex regions. Seemingly, Aβ42 oligomers trigger the events generating the neurotoxic Tau oligomers, which may even by themselves spread the characteristic AD neuropathology. It has been assumed that only neurons make and spread these toxic drivers, whereas their associated astrocytes are just janitorial bystanders/scavengers. But this view is likely to radically change since normal human astrocytes freshly isolated from adult cerebral cortex can be induced by exogenous Aβ25-35, an Aβ42 proxy, to make and secrete increased amounts of endogenous Aβ42. Thus, it would seem that the steady slow progression of AD neuropathology along specific cognition-relevant brain networks is driven by both Aβ42 and phosphorylated Tau oligomers that are variously released from increasing numbers of "contagion-stricken" members of tightly coupled neuron-astrocyte teams. Hence, we surmise that stopping the oversecretion and spread of the two kinds of "contagious" oligomers by such team members, perhaps via a specific CaSR (Ca(2+)-sensing receptor) antagonist like NPS 2143, might effectively treat AD.
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Affiliation(s)
- Ilaria Dal Prà
- Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy
| | - Anna Chiarini
- Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy
| | - Li Gui
- Department of Neurology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | | | - Raffaella Pacchiana
- Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy
| | - Emanuela Gardenal
- Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy
| | | | - Ubaldo Armato
- Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy
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527
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Cell-to-cell transmission of pathogenic proteins in neurodegenerative diseases. Nat Med 2014; 20:130-8. [PMID: 24504409 DOI: 10.1038/nm.3457] [Citation(s) in RCA: 472] [Impact Index Per Article: 47.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 12/19/2013] [Indexed: 12/12/2022]
Abstract
A common feature of many neurodegenerative diseases is the deposition of β-sheet-rich amyloid aggregates formed by proteins specific to these diseases. These protein aggregates are thought to cause neuronal dysfunction, directly or indirectly. Recent studies have strongly implicated cell-to-cell transmission of misfolded proteins as a common mechanism for the onset and progression of various neurodegenerative disorders. Emerging evidence also suggests the presence of conformationally diverse 'strains' of each type of disease protein, which may be another shared feature of amyloid aggregates, accounting for the tremendous heterogeneity within each type of neurodegenerative disease. Although there are many more questions to be answered, these studies have opened up new avenues for therapeutic interventions in neurodegenerative disorders.
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528
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George S, Rönnbäck A, Gouras GK, Petit GH, Grueninger F, Winblad B, Graff C, Brundin P. Lesion of the subiculum reduces the spread of amyloid beta pathology to interconnected brain regions in a mouse model of Alzheimer's disease. Acta Neuropathol Commun 2014; 2:17. [PMID: 24517102 PMCID: PMC3932948 DOI: 10.1186/2051-5960-2-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 02/03/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The progressive development of Alzheimer's disease (AD) pathology follows a spatiotemporal pattern in the human brain. In a transgenic (Tg) mouse model of AD expressing amyloid precursor protein (APP) with the arctic (E693G) mutation, pathology spreads along anatomically connected structures. Amyloid-β (Aβ) pathology first appears in the subiculum and is later detected in interconnected brain regions, including the retrosplenial cortex. We investigated whether the spatiotemporal pattern of Aβ pathology in the Tg APP arctic mice to interconnected brain structures can be interrupted by destroying neurons using a neurotoxin and thereby disconnecting the neural circuitry. RESULTS We performed partial unilateral ibotenic acid lesions of the subiculum (first structure affected by Aβ pathology) in young Tg APParc mice, prior to the onset of pathology. We assessed Aβ/C99 pathology in mice aged up to 6 months after injecting ibotenate into the subiculum. Compared to the brains of intact Tg APP arctic mice, we observed significantly decreased Aβ/C99 pathology in the ipsilateral dorsal subiculum, CA1 region of the hippocampus and the retrosplenial cortex; regions connecting to and from the dorsal subiculum. By contrast, Aβ/C99 pathology was unchanged in the contralateral hippocampus in the mice with lesions. CONCLUSION These results, obtained in an animal model of AD, support the notion that Aβ/C99 pathology is transmitted between interconnected neurons in AD.
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Affiliation(s)
- Sonia George
- Neuronal Survival Unit, Department of Experimental Medical Science, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, Michigan, USA
| | - Annica Rönnbäck
- Alzheimer Disease Research Center, Karolinska Institutet, Stockholm, Sweden
| | - Gunnar K Gouras
- Experimental Dementia Research Unit, Department of Experimental Medical Science, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Géraldine H Petit
- Neuronal Survival Unit, Department of Experimental Medical Science, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Fiona Grueninger
- CNS Discovery and Translation Pharma Research and Exploratory Development, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Bengt Winblad
- Alzheimer Disease Research Center, Karolinska Institutet, Stockholm, Sweden
| | - Caroline Graff
- Alzheimer Disease Research Center, Karolinska Institutet, Stockholm, Sweden
- Department of Geriatric Medicine, Genetics unit, Karolinska University Hospital, Stockholm, Sweden
| | - Patrik Brundin
- Neuronal Survival Unit, Department of Experimental Medical Science, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
- Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, Michigan, USA
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529
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Meyer V, Dinkel PD, Luo Y, Yu X, Wei G, Zheng J, Eaton GR, Ma B, Nussinov R, Eaton SS, Margittai M. Single mutations in tau modulate the populations of fibril conformers through seed selection. Angew Chem Int Ed Engl 2014; 53:1590-3. [PMID: 24453187 PMCID: PMC4083751 DOI: 10.1002/anie.201308473] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 11/13/2013] [Indexed: 12/20/2022]
Abstract
Seeded conversion of tau monomers into fibrils is a central step in the progression of tau pathology in Alzheimer's disease and other neurodegenerative disorders. Self-assembly is mediated by the microtubule binding repeats in tau. There are either three or four repeats present depending on the protein isoform. Here, double electron-electron resonance spectroscopy was used to investigate the conformational ensemble of four-repeat tau fibrils. Single point mutations at key positions in the protein (ΔK280, P301S, P312I, D314I) markedly change the distribution of fibril conformers after template-assisted growth, whereas other mutations in the protein (I308M, S320F, G323I, G326I, Q336R) do not. These findings provide unprecedented insights into the seed selection of tau disease mutants and establish conformational compatibility as an important driving force in tau fibril propagation.
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Affiliation(s)
- Virginia Meyer
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - Paul D. Dinkel
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - Yin Luo
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (MOE), and Department of Physics, Fudan University, Shanghai, P. R. China
| | - Xiang Yu
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Guanghong Wei
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (MOE), and Department of Physics, Fudan University, Shanghai, P. R. China
| | - Jie Zheng
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Gareth R. Eaton
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - Buyong Ma
- Basic Science Program, SAIC-Frederick, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Ruth Nussinov
- Basic Science Program, SAIC-Frederick, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland 21702, United States
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Sandra S. Eaton
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - Martin Margittai
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
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530
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Clavaguera F, Hench J, Lavenir I, Schweighauser G, Frank S, Goedert M, Tolnay M. Peripheral administration of tau aggregates triggers intracerebral tauopathy in transgenic mice. Acta Neuropathol 2014; 127:299-301. [PMID: 24362441 PMCID: PMC4253855 DOI: 10.1007/s00401-013-1231-5] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 12/08/2013] [Accepted: 12/09/2013] [Indexed: 12/05/2022]
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531
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Dujardin S, Lécolle K, Caillierez R, Bégard S, Zommer N, Lachaud C, Carrier S, Dufour N, Aurégan G, Winderickx J, Hantraye P, Déglon N, Colin M, Buée L. Neuron-to-neuron wild-type Tau protein transfer through a trans-synaptic mechanism: relevance to sporadic tauopathies. Acta Neuropathol Commun 2014; 2:14. [PMID: 24479894 PMCID: PMC3922636 DOI: 10.1186/2051-5960-2-14] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 01/16/2014] [Indexed: 12/31/2022] Open
Abstract
Background In sporadic Tauopathies, neurofibrillary degeneration (NFD) is characterised by the intraneuronal aggregation of wild-type Tau proteins. In the human brain, the hierarchical pathways of this neurodegeneration have been well established in Alzheimer’s disease (AD) and other sporadic tauopathies such as argyrophilic grain disorder and progressive supranuclear palsy but the molecular and cellular mechanisms supporting this progression are yet not known. These pathways appear to be associated with the intercellular transmission of pathology, as recently suggested in Tau transgenic mice. However, these conclusions remain ill-defined due to a lack of toxicity data and difficulties associated with the use of mutant Tau. Results Using a lentiviral-mediated rat model of hippocampal NFD, we demonstrated that wild-type human Tau protein is axonally transferred from ventral hippocampus neurons to connected secondary neurons even at distant brain areas such as olfactory and limbic systems indicating a trans-synaptic protein transfer. Using different immunological tools to follow phospho-Tau species, it was clear that Tau pathology generated using mutated Tau remains near the IS whereas it spreads much further using the wild-type one. Conclusion Taken together, these results support a novel mechanism for Tau protein transfer compared to previous reports based on transgenic models with mutant cDNA. It also demonstrates that mutant Tau proteins are not suitable for the development of experimental models helpful to validate therapeutic intervention interfering with Tau spreading.
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532
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Meyer V, Dinkel PD, Luo Y, Yu X, Wei G, Zheng J, Eaton GR, Ma B, Nussinov R, Eaton SS, Margittai M. Single Mutations in Tau Modulate the Populations of Fibril Conformers through Seed Selection. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201308473] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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533
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Iqbal K, Liu F, Gong CX. Alzheimer disease therapeutics: focus on the disease and not just plaques and tangles. Biochem Pharmacol 2014; 88:631-9. [PMID: 24418409 DOI: 10.1016/j.bcp.2014.01.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 12/26/2013] [Accepted: 01/02/2014] [Indexed: 12/13/2022]
Abstract
The bulk of AD research during the last 25 years has been Aβ-centric based on a strong faith in the Amyloid Cascade Hypothesis which is not supported by the data on humans. To date, Aβ-based therapeutic clinical trials on sporadic cases of AD have been negative. Although most likely the major reason for the failure is that Aβ is not an effective therapeutic target for sporadic AD, initiation of the treatment at mild to moderate stages of the disease is blamed as too late to be effective. Clinical trials on presymptomatic familial AD cases have been initiated with the logic that Aβ is a trigger of the disease and hence initiation of the Aβ immunotherapies several years before any clinical symptoms would be effective. There is an urgent need to explore targets other than Aβ. There is now increasing interest in inhibiting tau pathology, which does have a far more compelling rationale than Aβ. AD is multifactorial and over 99% of the cases are the sporadic form of the disease. Understanding of the various etiopathogenic mechanisms of sporadic AD and generation of the disease-relevant animal models are required to develop rational therapeutic targets and therapies. Treatment of AD will require both inhibition of neurodegeneration and regeneration of the brain.
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Affiliation(s)
- Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA.
| | - Fei Liu
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA
| | - Cheng-Xin Gong
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA
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534
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Caillet-Boudin ML, Fernandez-Gomez FJ, Tran H, Dhaenens CM, Buee L, Sergeant N. Brain pathology in myotonic dystrophy: when tauopathy meets spliceopathy and RNAopathy. Front Mol Neurosci 2014; 6:57. [PMID: 24409116 PMCID: PMC3885824 DOI: 10.3389/fnmol.2013.00057] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 12/20/2013] [Indexed: 01/18/2023] Open
Abstract
Myotonic dystrophy (DM) of type 1 and 2 (DM1 and DM2) are inherited autosomal dominant diseases caused by dynamic and unstable expanded microsatellite sequences (CTG and CCTG, respectively) in the non-coding regions of the genes DMPK and ZNF9, respectively. These mutations result in the intranuclear accumulation of mutated transcripts and the mis-splicing of numerous transcripts. This so-called RNA gain of toxic function is the main feature of an emerging group of pathologies known as RNAopathies. Interestingly, in addition to these RNA inclusions, called foci, the presence of neurofibrillary tangles (NFT) in patient brains also distinguishes DM as a tauopathy. Tauopathies are a group of nearly 30 neurodegenerative diseases that are characterized by intraneuronal protein aggregates of the microtubule-associated protein Tau (MAPT) in patient brains. Furthermore, a number of neurodegenerative diseases involve the dysregulation of splicing regulating factors and have been characterized as spliceopathies. Thus, myotonic dystrophies are pathologies resulting from the interplay among RNAopathy, spliceopathy, and tauopathy. This review will describe how these processes contribute to neurodegeneration. We will first focus on the tauopathy associated with DM1, including clinical symptoms, brain histology, and molecular mechanisms. We will also discuss the features of DM1 that are shared by other tauopathies and, consequently, might participate in the development of a tauopathy. Moreover, we will discuss the determinants common to both RNAopathies and spliceopathies that could interfere with tau-related neurodegeneration.
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Affiliation(s)
- Marie-Laure Caillet-Boudin
- Alzheimer and Tauopathies, Faculty of Medicine, Jean-Pierre Aubert Research Centre, Institute of Predictive Medicine and Therapeutic Research, Inserm, UMR 837 Lille, France ; University of Lille Nord de France, UDSL Lille, France
| | - Francisco-Jose Fernandez-Gomez
- Alzheimer and Tauopathies, Faculty of Medicine, Jean-Pierre Aubert Research Centre, Institute of Predictive Medicine and Therapeutic Research, Inserm, UMR 837 Lille, France ; University of Lille Nord de France, UDSL Lille, France
| | - Hélène Tran
- Alzheimer and Tauopathies, Faculty of Medicine, Jean-Pierre Aubert Research Centre, Institute of Predictive Medicine and Therapeutic Research, Inserm, UMR 837 Lille, France ; University of Lille Nord de France, UDSL Lille, France
| | - Claire-Marie Dhaenens
- Alzheimer and Tauopathies, Faculty of Medicine, Jean-Pierre Aubert Research Centre, Institute of Predictive Medicine and Therapeutic Research, Inserm, UMR 837 Lille, France ; University of Lille Nord de France, UDSL Lille, France
| | - Luc Buee
- Alzheimer and Tauopathies, Faculty of Medicine, Jean-Pierre Aubert Research Centre, Institute of Predictive Medicine and Therapeutic Research, Inserm, UMR 837 Lille, France ; University of Lille Nord de France, UDSL Lille, France
| | - Nicolas Sergeant
- Alzheimer and Tauopathies, Faculty of Medicine, Jean-Pierre Aubert Research Centre, Institute of Predictive Medicine and Therapeutic Research, Inserm, UMR 837 Lille, France ; University of Lille Nord de France, UDSL Lille, France
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535
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Alzheimer’s Disease and Frontotemporal Lobar Degeneration: Mouse Models. NEURODEGENER DIS 2014. [DOI: 10.1007/978-1-4471-6380-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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536
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Abstract
AbstractAlzheimer’s disease (AD) is a neurodegenerative disorder that is characterized by normal memory loss and cognitive impairment in humans. Many drug targets and disease-modulating therapies are available for treatment of AD, but none of these are effective enough in reducing problems associated with recognition and memory. Potential drug targets so far reported for AD are β-secretase, Γ-secretase, amyloid beta (Aβ) and Aβ fibrils, glycogen synthase kinase-3 (GSK-3), acyl-coenzyme A: cholesterol acyl-transferase (ACAT) and acetylcholinesterase (AChE). Herbal remedies (antioxidants) and natural metal-chelators have shown a very significant role in reducing the risk of AD, as well as lowering the effect of Aβ in AD patients. Researchers are working in the direction of antisense and stem cell-based therapies for a cure for AD, which mainly depends on the clearance of misfolded protein deposits — including Aβ, tau, and alpha-synuclein. Computational approaches for inhibitor designing, interaction analysis, principal descriptors and an absorption, distribution, metabolism, excretion and toxicity (ADMET) study could speed up the process of drug development with higher efficacy and less chance of failure. This paper reviews the known drugs, drug targets, and existing and future therapies for the treatment of AD.
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537
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Liu C, Götz J. Profiling murine tau with 0N, 1N and 2N isoform-specific antibodies in brain and peripheral organs reveals distinct subcellular localization, with the 1N isoform being enriched in the nucleus. PLoS One 2013; 8:e84849. [PMID: 24386422 PMCID: PMC3875548 DOI: 10.1371/journal.pone.0084849] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Accepted: 11/19/2013] [Indexed: 11/18/2022] Open
Abstract
In the adult murine brain, the microtubule-associated protein tau exists as three major isoforms, which have four microtubule-binding repeats (4R), with either no (0N), one (1N) or two (2N) amino-terminal inserts. The human brain expresses three additional isoforms with three microtubule-binding repeats (3R) each. However, little is known about the role of the amino-terminal inserts and how the 0N, 1N and 2N tau species differ. In order to investigate this, we generated a series of isoform-specific antibodies and performed a profiling by Western blotting and immunohistochemical analyses using wild-type mice in three age groups: two months, two weeks and postnatal day 0 (P0). This revealed that the brain is the only organ to express tau at significant levels, with 0N4R being the predominant isoform in the two month-old adult. Subcellular fractionation of the brain showed that the 1N isoform is over-represented in the soluble nuclear fraction. This is in agreement with the immunohistochemical analysis as the 1N isoform strongly localizes to the neuronal nucleus, although it is also found in cell bodies and dendrites, but not axons. The 0N isoform is mainly found in cell bodies and axons, whereas nuclei and dendrites are only slightly stained with the 0N antibody. The 2N isoform is highly expressed in axons and in cell bodies, with a detectable expression in dendrites and a very slight expression in nuclei. The 2N isoform that was undetectable at P0, in adult brain was mainly found localized to cell bodies and dendrites. Together these findings reveal significant differences between the three murine tau isoforms that are likely to reflect different neuronal functions.
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Affiliation(s)
- Chang Liu
- Sydney Medical School, Brain and Mind Research Institute, University of Sydney, Camperdown, New South Wales, Australia
| | - Jürgen Götz
- Sydney Medical School, Brain and Mind Research Institute, University of Sydney, Camperdown, New South Wales, Australia
- Clem Jones Centre for Ageing Dementia Research (CJCADR), Queensland Brain Institute (QBI), The University of Queensland, St Lucia Campus, Brisbane, Queensland, Australia
- * E-mail:
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538
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Jucker M, Walker LC. Self-propagation of pathogenic protein aggregates in neurodegenerative diseases. Nature 2013; 501:45-51. [PMID: 24005412 DOI: 10.1038/nature12481] [Citation(s) in RCA: 1149] [Impact Index Per Article: 104.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/17/2013] [Indexed: 12/12/2022]
Abstract
For several decades scientists have speculated that the key to understanding age-related neurodegenerative disorders may be found in the unusual biology of the prion diseases. Recently, owing largely to the advent of new disease models, this hypothesis has gained experimental momentum. In a remarkable variety of diseases, specific proteins have been found to misfold and aggregate into seeds that structurally corrupt like proteins, causing them to aggregate and form pathogenic assemblies ranging from small oligomers to large masses of amyloid. Proteinaceous seeds can therefore serve as self-propagating agents for the instigation and progression of disease. Alzheimer's disease and other cerebral proteopathies seem to arise from the de novo misfolding and sustained corruption of endogenous proteins, whereas prion diseases can also be infectious in origin. However, the outcome in all cases is the functional compromise of the nervous system, because the aggregated proteins gain a toxic function and/or lose their normal function. As a unifying pathogenic principle, the prion paradigm suggests broadly relevant therapeutic directions for a large class of currently intractable diseases.
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Affiliation(s)
- Mathias Jucker
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, D-72076 Tübingen, Germany.
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539
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Abstract
Alzheimer's disease (AD) is associated with the deposition of β-amyloid (Aβ) plaques in the brain. In this issue, by cleverly processing patient samples, Lu et al. define a novel structural model of Aβ fibrils from AD brain, revealing surprising differences from in vitro fibrils. These findings may lead to structure-specific inhibitors and more selective amyloid-imaging methods.
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Affiliation(s)
- Adriano Aguzzi
- Institute of Neuropathology, University Hospital Zurich, 8091 Zurich, Switzerland.
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540
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Modeling Alzheimer's disease in mouse without mutant protein overexpression: cooperative and independent effects of Aβ and tau. PLoS One 2013; 8:e80706. [PMID: 24278307 PMCID: PMC3835479 DOI: 10.1371/journal.pone.0080706] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Accepted: 10/15/2013] [Indexed: 01/23/2023] Open
Abstract
Background Alzheimer’s disease (AD), the most common cause of dementia in the elderly, has two pathological hallmarks: Aβ plaques and aggregation of hyperphosphorylated tau (p-tau). Aβ is a cleavage product of Amyloid Precursor Protein (APP). Presenilin 1 (PS1) and presenilin 2 (PS2) are the catalytic subunit of γ-secretase, which cleaves APP and mediates Aβ production. Genetic mutations in APP, PSEN1 or PSEN2 can lead to early onset of familial AD (FAD). Although mutations in the tau encoding gene MAPT leads to a subtype of frontotemporal dementia and these mutations have been used to model AD tauopathy, no MAPT mutations have been found to be associated with AD. Results To model AD pathophysiology in mice without the gross overexpression of mutant transgenes, we created a humanized AD mouse model by crossing the APP and PSEN1 FAD knock-in mice with the htau mice which express wildtype human MAPT genomic DNA on mouse MAPT null background (APP/PS1/htau). The APP/PS1/htau mice displayed mild, age-dependent, Aβ plaques and tau hyperphosphorylation, thus successfully recapitulating the late-onset AD pathological hallmarks. Selected biochemical analyses, including p-tau western blot, γ-secretase activity assay, and Aβ ELISA, were performed to study the interaction between Aβ and p-tau. Subsequent behavioral studies revealed that the APP/PS1/htau mice showed reduced mobility in old ages and exaggerated fear response. Genetic analysis suggested that the fear phenotype is due to a synergic interaction between Aβ and p-tau, and it can be completely abolished by tau deletion. Conclusion The APP/PS1/htau model represents a valuable and disease-relevant late-onset pre-clinical AD animal model because it incorporates human AD genetics without mutant protein overexpression. Analysis of the mice revealed both cooperative and independent effects of Aβ and p-tau.
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541
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Abstract
Prions are proteins that adopt alternative conformations, which become self-propagating. Increasing evidence argues that prions feature in the synucleinopathies that include Parkinson's disease, Lewy body dementia, and multiple system atrophy (MSA). Although TgM83(+/+) mice homozygous for a mutant A53T α-synuclein transgene begin developing CNS dysfunction spontaneously at ∼10 mo of age, uninoculated TgM83(+/-) mice (hemizygous for the transgene) remain healthy. To determine whether MSA brains contain α-synuclein prions, we inoculated the TgM83(+/-) mice with brain homogenates from two pathologically confirmed MSA cases. Inoculated TgM83(+/-) mice developed progressive signs of neurologic disease with an incubation period of ∼100 d, whereas the same mice inoculated with brain homogenates from spontaneously ill TgM83(+/+) mice developed neurologic dysfunction in ∼210 d. Brains of MSA-inoculated mice exhibited prominent astrocytic gliosis and microglial activation as well as widespread deposits of phosphorylated α-synuclein that were proteinase K sensitive, detergent insoluble, and formic acid extractable. Our results provide compelling evidence that α-synuclein aggregates formed in the brains of MSA patients are transmissible and, as such, are prions. The MSA prion represents a unique human pathogen that is lethal upon transmission to Tg mice and as such, is reminiscent of the prion causing kuru, which was transmitted to chimpanzees nearly 5 decades ago.
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542
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Propagation of tau pathology in Alzheimer's disease: identification of novel therapeutic targets. ALZHEIMERS RESEARCH & THERAPY 2013; 5:49. [PMID: 24152385 PMCID: PMC3978816 DOI: 10.1186/alzrt214] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Accumulation and aggregation of the microtubule-associated protein tau are a pathological hallmark of neurodegenerative disorders such as Alzheimer’s disease (AD). In AD, tau becomes abnormally phosphorylated and forms inclusions throughout the brain, starting in the entorhinal cortex and progressively affecting additional brain regions as the disease progresses. Formation of these inclusions is thought to lead to synapse loss and cell death. Tau is also found in the cerebrospinal fluid (CSF), and elevated levels are a biomarker for AD. Until recently, it was thought that the presence of tau in the CSF was due to the passive release of aggregated tau from dead or dying tangle-bearing neurons. However, accumulating evidence from different AD model systems suggests that tau is actively secreted and transferred between synaptically connected neurons. Transgenic mouse lines with localized expression of aggregating human tau in the entorhinal cortex have demonstrated that, as these animals age, tau becomes mislocalized from axons to cell bodies and dendrites and that human tau-positive aggregates form first in the entorhinal cortex and later in downstream projection targets. Numerous in vitro and in vivo studies have provided insight into the mechanisms by which tau may be released and internalized by neurons and have started to provide insight into how tau pathology may spread in AD. In this review, we discuss the evidence for regulated tau release and its specific uptake by neurons. Furthermore, we identify possible therapeutic targets for preventing the propagation of tau pathology, as inhibition of tau transfer may restrict development of tau tangles in a small subset of neurons affected in early stages of AD and therefore prevent widespread neuron loss and cognitive dysfunction associated with later stages of the disease.
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543
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Miller MB, Wang DW, Wang F, Noble GP, Ma J, Woods VL, Li S, Supattapone S. Cofactor molecules induce structural transformation during infectious prion formation. Structure 2013; 21:2061-8. [PMID: 24120764 DOI: 10.1016/j.str.2013.08.025] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 08/30/2013] [Accepted: 08/30/2013] [Indexed: 12/12/2022]
Abstract
The spread of misfolded proteins may occur in many neurodegenerative diseases. Mammalian prions are currently the only misfolded proteins in which high specific biological infectivity can be produced in vitro. Using a system that generates infectious prions de novo from purified recombinant PrP and conversion cofactors palmitoyl-oleoyl-phosphatidylglycerol (POPG) and RNA, we examined by deuterium exchange mass spectrometry (DXMS) the stepwise protein conformational changes that occur during prion formation. We found that initial incubation with POPG causes major structural changes in PrP involving all three α helices and one β strand, with subsequent addition of RNA rendering the N terminus highly exposed. Final conversion into the infectious PrP(Sc) form was accompanied by globally decreased solvent exposure, with persistence of the major cofactor-induced conformational features. Thus, we report that cofactor molecules appear to induce major structural rearrangements during prion formation, initiating a dynamic sequence of conformational changes resulting in biologically active prions.
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Affiliation(s)
- Michael B Miller
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
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544
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Morozova OA, March ZM, Robinson AS, Colby DW. Conformational features of tau fibrils from Alzheimer's disease brain are faithfully propagated by unmodified recombinant protein. Biochemistry 2013; 52:6960-7. [PMID: 24033133 DOI: 10.1021/bi400866w] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Fibrils composed of tau protein are a pathological hallmark of several neurodegenerative disorders including Alzheimer's disease (AD). Here we show that when recombinant tau protein is seeded with paired helical filaments (PHFs) isolated from AD brain, the amyloid formed shares many of the structural features of AD PHFs. In contrast, tau amyloids formed with heparin as an inducing agent-a common biochemical model of tau misfolding-are structurally distinct from brain-derived PHFs. Using ultrastructural analysis by electron microscopy, circular dichroism, and chemical denaturation, we found that AD seeded recombinant tau fibrils were not significantly different than tau fibrils isolated from AD brain tissue. Tau fibrils produced by incubating recombinant tau with heparin had significantly narrower fibrils with a longer periodicity, higher chemical stability, and distinct secondary structure compared to AD PHFs. The addition of heparin to the reaction of recombinant tau and AD PHFs also corrupted the templating process, resulting in a mixture of fibril conformations. Our results suggest that AD-isolated PHFs act as a conformational template for the formation of recombinant tau fibrils. Therefore, the use of AD PHFs as seeds to stimulate recombinant tau amyloid formation produces synthetic tau fibers that closely resemble those associated with AD pathology and provides a biochemical model of tau misfolding that may be of improved utility for structural studies and drug screening. These results also demonstrate that post-translational modifications such as phosphorylation are not a prerequisite for the propagation of the tau fibril conformation found in AD.
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Affiliation(s)
- Olga A Morozova
- Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States
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545
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Clavaguera F, Grueninger F, Tolnay M. Intercellular transfer of tau aggregates and spreading of tau pathology: Implications for therapeutic strategies. Neuropharmacology 2013; 76 Pt A:9-15. [PMID: 24050961 DOI: 10.1016/j.neuropharm.2013.08.037] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 08/27/2013] [Accepted: 08/30/2013] [Indexed: 11/16/2022]
Abstract
Filaments made of hyperphosphorylated tau protein are encountered in a group of neurodegenerative disorders termed tauopathies. The most prevalent tauopathy, Alzheimer's disease (AD), additionally presents with extracellular deposits of the amyloid-β peptide (Aβ). Current symptomatic treatments have shown short term benefits in reducing cognitive symptoms as well as behavioral abnormalities in patients with mild to moderate AD but there is still no effective treatment to prevent or reverse AD. For decades, the amyloid cascade hypothesis of AD dominated basic research and focused pharmaceutical interest on Aβ. However, the existence of tauopathies that are devoid of Aβ deposits, together with the discovery of mutations in the tau gene leading to frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17T), confirmed the importance of tau per se in disease. Tau became an interesting disease target in its own right. We will review here recent research on cell-to-cell propagation of tau pathology, which we believe to be central to disease progression, and discuss tau immunotherapy in the light of these findings. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'.
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Affiliation(s)
- Florence Clavaguera
- Department of Neuropathology, Institute of Pathology, University Hospital, Schoenbeinstrasse 40, 4031 Basel, Switzerland
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546
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Duyckaerts C. Neurodegenerative lesions: seeding and spreading. Rev Neurol (Paris) 2013; 169:825-33. [PMID: 24035591 DOI: 10.1016/j.neurol.2013.07.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 07/16/2013] [Indexed: 11/25/2022]
Abstract
Accumulation of specific proteins has replaced loss of specific populations of neurons in the definition of most neurodegenerative diseases. In some cases, the amino-acid sequence of the protein that accumulates is altered by a mutation in the gene that codes for it but most generally, the primary structure is normal. Much evidence from human neuropathology has been collected over the years indicating that the progression of the lesions in such neurodegenerative diseases as Alzheimer's disease, Parkinson's disease and progressive supranuclear palsy follow the neuroanatomical connections. More recently, injection of aggregates of the specific proteins in the brain of experimental animals has been attempted in various experimental settings. Brain homogenates containing Aβ aggregates induce the early development of Aβ deposits in APP transgenic mice. Brain homogenates from various human tauopathies induce tau aggregates in transgenic mice expressing normal human tau. Finally, synthetic preformed fibrils of alpha-synuclein initiate the development of alpha-synuclein accumulation resembling Parkinson's disease in wild-type mice. Experiments in cell cultures suggest that the protein has to be in some specific state of oligomerization or fibrillation to be endocytosed and transported by the neuron. These data suggest that the protein that accumulates in a specific disease is initially misfolded and that this misfolding contaminates normal protein in a prion-like manner - in some cases through the neuronal connections.
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Affiliation(s)
- C Duyckaerts
- Laboratoire de neuropathologie Raymond-Escourolle, hôpital de la Pitié-Salpêtrière, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Centre de recherche de l'ICM, équipe Alzheimer-Prion, 47, boulevard de l'Hôpital, 750713 Paris, France.
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547
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Dan A, Takahashi M, Masuda-Suzukake M, Kametani F, Nonaka T, Kondo H, Akiyama H, Arai T, Mann DMA, Saito Y, Hatsuta H, Murayama S, Hasegawa M. Extensive deamidation at asparagine residue 279 accounts for weak immunoreactivity of tau with RD4 antibody in Alzheimer's disease brain. Acta Neuropathol Commun 2013; 1:54. [PMID: 24252707 PMCID: PMC3893535 DOI: 10.1186/2051-5960-1-54] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Accepted: 08/17/2013] [Indexed: 11/25/2022] Open
Abstract
Background Intracytoplasmic inclusions composed of filamentous tau proteins are defining characteristics of neurodegenerative tauopathies, but it remains unclear why different tau isoforms accumulate in different diseases and how they induce abnormal filamentous structures and pathologies. Two tau isoform-specific antibodies, RD3 and RD4, are widely used for immunohistochemical and biochemical studies of tau species in diseased brains. Results Here, we show that extensive irreversible post-translational deamidation takes place at asparagine residue 279 (N279) in the RD4 epitope of tau in Alzheimer’s disease (AD), but not corticobasal degeneration (CBD) or progressive supranuclear palsy (PSP), and this modification abrogates the immunoreactivity to RD4. An antiserum raised against deamidated RD4 peptide specifically recognized 4R tau isoforms, regardless of deamidation, and strongly stained tau in AD brain. We also found that mutant tau with N279D substitution showed reduced ability to bind to microtubules and to promote microtubule assembly. Conclusion The biochemical and structural differences of tau in AD from that in 4R tauopathies found in this study may therefore have implications for prion-like propagation of tau.
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