Human tauopathy-derived tau strains determine the substrates recruited for templated amplification

Abstract Tauopathies are a subset of neurodegenerative diseases characterized by abnormal tau inclusions. Specifically, three-repeat tau and four-repeat tau in Alzheimer’s disease (AD), three-repeat tau in Pick's disease (PiD) and four-repeat in progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) form amyloid-like fibrous structures that accumulate in neurons and/or glial cells. Amplification and cell-to-cell transmission of abnormal tau based on the prion hypothesis are believed to explain the onset and progression of tauopathies. Recent studies support not only the self-propagation of abnormal tau, but also the presence of conformationally distinct tau aggregates, namely tau strains. Cryo-electron microscopy analyses of patient-derived tau filaments have revealed disease-specific ordered tau structures. However, it remains unclear whether the ultrastructural and biochemical properties of tau strains are inherited during the amplification of abnormal tau in the brain. In this study, we investigated template-dependent amplification of tau aggregates using a cellular model of seeded aggregation. Tau strains extracted from human tauopathies caused strain-dependent accumulation of insoluble filamentous tau in SH-SY5Y cells. The seeding activity towards full-length four-repeat tau substrate was highest in CBD-tau seeds, followed by PSP-tau and AD-tau seeds, while AD-tau seeds showed higher seeding activity than PiD-tau seeds towards three-repeat tau substrates. Abnormal tau amplified in cells inherited the ultrastructural and biochemical properties of the original seeds. These results strongly suggest that the structural differences of patient-derived tau strains underlie the diversity of tauopathies, and that seeded aggregation and filament formation mimicking the pathogenesis of sporadic tauopathy can be reproduced in cultured cells. Our results indicate that the disease-specific conformation of tau aggregates determines the tau isoform substrate that is recruited for templated amplification, and also influences the prion-like seeding activity.

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Co-factor-free aggregation of tau into seeding-competent RNA-sequestering amyloid fibrils

Nature Communications ◽

10.1038/s41467-021-24362-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Pijush Chakraborty ◽

Gwladys Rivière ◽

Shu Liu ◽

Alain Ibáñez de Opakua ◽

Rıza Dervişoğlu ◽

...

Keyword(s):

Amyloid Fibrils ◽

Corticobasal Degeneration ◽

Binding Studies ◽

Rigid Core ◽

Tau Aggregation ◽

The Brain ◽

Tau Aggregate ◽

Disease Specific ◽

Tau Fibrils

AbstractPathological aggregation of the protein tau into insoluble aggregates is a hallmark of neurodegenerative diseases. The emergence of disease-specific tau aggregate structures termed tau strains, however, remains elusive. Here we show that full-length tau protein can be aggregated in the absence of co-factors into seeding-competent amyloid fibrils that sequester RNA. Using a combination of solid-state NMR spectroscopy and biochemical experiments we demonstrate that the co-factor-free amyloid fibrils of tau have a rigid core that is similar in size and location to the rigid core of tau fibrils purified from the brain of patients with corticobasal degeneration. In addition, we demonstrate that the N-terminal 30 residues of tau are immobilized during fibril formation, in agreement with the presence of an N-terminal epitope that is specifically detected by antibodies in pathological tau. Experiments in vitro and in biosensor cells further established that co-factor-free tau fibrils efficiently seed tau aggregation, while binding studies with different RNAs show that the co-factor-free tau fibrils strongly sequester RNA. Taken together the study provides a critical advance to reveal the molecular factors that guide aggregation towards disease-specific tau strains.

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Amyloid imaging probes are useful for detection of prion plaques and treatment of transmissible spongiform encephalopathies

Journal of General Virology ◽

10.1099/vir.0.19754-0 ◽

2004 ◽

Vol 85 (6) ◽

pp. 1785-1790 ◽

Cited By ~ 48

Author(s):

Kensuke Ishikawa ◽

Katsumi Doh-ura ◽

Yukitsuka Kudo ◽

Noriyuki Nishida ◽

Ikuko Murakami-Kubo ◽

...

Keyword(s):

Transmissible Spongiform Encephalopathies ◽

Dependent Manner ◽

Cellular Model ◽

Spongiform Encephalopathies ◽

Therapeutic Drugs ◽

Experimental Mouse Model ◽

Imaging Probes ◽

Experimental Mouse ◽

The Brain ◽

Strain Dependent

Diagnostic imaging probes have been developed to monitor cerebral amyloid lesions in patients with neurodegenerative disorders. A thioflavin derivative, 2-[4′-(methylamino)phenyl] benzothiazole (BTA-1) and a Congo red derivative, (trans, trans),-1-bromo-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (BSB) are representative chemicals of these probes. In this report, the two chemicals were studied in transmissible spongiform encephalopathies (TSE). Both BTA-1 and BSB selectively bound to compact plaques of prion protein (PrP), not only in the brain specimens of certain types of human TSE, but also in the brains of TSE-infected mice when the probes were injected intravenously. The chemicals bound to plaques in the brains were stable and could be detected for more than 42 h post-injection. In addition, the chemicals inhibited abnormal PrP formation in a cellular model of TSE with IC50 values of 4 nM for BTA-1 and 1·4 μM for BSB. In an experimental mouse model, the intravenous injection of 1 mg BSB prolonged the incubation period by 14 %. This efficacy was only observed against the RML strain and not the other strains examined. These observations suggest that these chemicals bind directly to PrP aggregates and inhibit new formation of abnormal PrP in a strain-dependent manner. Both BTA-1 and BSB can be expected to be lead chemicals not only for imaging probes but also for therapeutic drugs for TSEs caused by certain strains.

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Role of molecular polymorphism in defining tau filament structures in neurodegenerative diseases

10.1101/2021.05.24.445353 ◽

2021 ◽

Author(s):

Xinyu Xiang ◽

Tamta Arakhamia ◽

Yari Carlomagno ◽

Shikhar Dhingra ◽

Manon Thierry ◽

...

Keyword(s):

Neurodegenerative Diseases ◽

Tau Protein ◽

Molecular Level ◽

Corticobasal Degeneration ◽

Molecular Polymorphism ◽

Cofactor Binding ◽

Tau Isoforms ◽

The Brain ◽

Disease Specific

Misfolding and aggregation of tau protein is implicated in many neurodegenerative diseases that are typified by the presence of large, filamentous tau inclusions. The aggregation of tau in human brain is disease-specific with characteristic filaments defining the neuropathology. An understanding of how identical tau isoforms aggregate into disparate filament morphologies in phenotypically distinct tau-related diseases remains elusive. Here, we determine the structure of a brain-derived twisted tau filament in progressive supranuclear palsy and compare it to a dissimilar tau fold found in corticobasal degeneration. While the tau filament core in both diseases is comprised of residues 274 to 380, molecular-level polymorphism exists. Potential origins of the molecular polymorphism, such as noncovalent cofactor binding, are identified and predicted to modulate tau filament structures in the brain.

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Tau strains shape disease

Acta Neuropathologica ◽

10.1007/s00401-021-02301-7 ◽

2021 ◽

Author(s):

Jaime Vaquer-Alicea ◽

Marc I. Diamond ◽

Lukasz A. Joachimiak

Keyword(s):

Neurodegenerative Diseases ◽

Cultured Cells ◽

Monomer Unit ◽

Corticobasal Degeneration ◽

Amino Acid Sequences ◽

Protein Assemblies ◽

Protein Tau ◽

Aggregation Propensity ◽

Argyrophilic Grain ◽

Prion Hypothesis

AbstractTauopathies consist of over 25 different neurodegenerative diseases that include argyrophilic grain disease (AGD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and Pick’s disease (PiD). Tauopathies are defined by brain accumulation of microtubule-associated protein tau in fibrillar aggregates, whose prevalence strongly correlates with dementia. Dominant mutations in tau cause neurodegenerative diseases, and most increase its aggregation propensity. Pathogenesis of tauopathies may involve pathological tau conformers that serve as templates to recruit native protein into growing assemblies and also move between brain cells to cause disease progression, similar to prions. Prions adopt pathological conformations, termed “strains,” that stably propagate in living systems, and create unique patterns of neuropathology. Data from multiple laboratories now suggest that tau acts as a prion. It propagates unique strains indefinitely in cultured cells, and when these are inoculated into mouse models, they create defined neuropathological patterns, which establish a direct link between conformation and disease. In humans, distinct fibril structures are associated with different diseases, but causality has not been established as in mice. Cryo-EM structures of tau fibrils isolated from tauopathy brains reveal distinct fibril cores across disease. Interestingly, the conformation of the tau monomer unit within different fibril subtypes from the same patient appears relatively preserved. This is consistent with data that the tau monomer samples an ensemble of conformations that act as distinct pathologic templates in the formation of restricted numbers of strains. The propensity of a tau monomer to adopt distinct conformations appears to be linked to defined local motifs that expose different patterns of amyloidogenic amino acid sequences. The prion hypothesis, which predicts that protein structure dictates resultant disease, has proved particularly useful to understand the diversity of human tauopathies. The challenge now is to develop methods to rapidly classify patients according to the structure of the underlying pathological protein assemblies to achieve more accurate diagnosis and effective therapy.

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In vitro amplification of pathogenic tau conserves disease-specific bioactive characteristics

Acta Neuropathologica ◽

10.1007/s00401-020-02253-4 ◽

2021 ◽

Author(s):

Hong Xu ◽

Mia O’Reilly ◽

Garrett S. Gibbons ◽

Lakshmi Changolkar ◽

Jennifer D. McBride ◽

...

Keyword(s):

Tau Protein ◽

Biological Activities ◽

Corticobasal Degeneration ◽

Tau Pathology ◽

Protein Tau ◽

Beta Sheet Structure ◽

Sheet Structure ◽

Strain Dependent ◽

Disease Specific

AbstractThe microtubule-associated protein tau (tau) forms hyperphosphorylated aggregates in the brains of tauopathy patients that can be pathologically and biochemically defined as distinct tau strains. Recent studies show that these tau strains exhibit strain-specific biological activities, also referred to as pathogenicities, in the tau spreading models. Currently, the specific pathogenicity of human-derived tau strains cannot be fully recapitulated by synthetic tau preformed fibrils (pffs), which are generated from recombinant tau protein. Reproducing disease-relevant tau pathology in cell and animal models necessitates the use of human brain-derived tau seeds. However, the availability of human-derived tau is extremely limited. Generation of tau variants that can mimic the pathogenicity of human-derived tau seeds would significantly extend the scale of experimental design within the field of tauopathy research. Previous studies have demonstrated that in vitro seeding reactions can amplify the beta-sheet structure of tau protein from a minute quantity of human-derived tau. However, whether the strain-specific pathogenicities of the original, human-derived tau seeds are conserved in the amplified tau strains has yet to be experimentally validated. Here, we used biochemically enriched brain-derived tau seeds from Alzheimer’s disease (AD), corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) patient brains with a modified seeding protocol to template the recruitment of recombinant 2N4R (T40) tau in vitro. We quantitatively interrogated efficacy of the amplification reactions and the pathogenic fidelity of the amplified material to the original tau seeds using recently developed sporadic tau spreading models. Our data suggest that different tau strains can be faithfully amplified in vitro from tau isolated from different tauopathy brains and that the amplified tau variants retain their strain-dependent pathogenic characteristics.

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Mechanisms of Neurodegeneration in Various Forms of Parkinsonism—Similarities and Differences

Cells ◽

10.3390/cells10030656 ◽

2021 ◽

Vol 10 (3) ◽

pp. 656

Author(s):

Dariusz Koziorowski ◽

Monika Figura ◽

Łukasz M. Milanowski ◽

Stanisław Szlufik ◽

Piotr Alster ◽

...

Keyword(s):

Neurodegenerative Diseases ◽

Tau Protein ◽

Protein Gene ◽

Clinical Presentation ◽

Neuronal Loss ◽

Corticobasal Degeneration ◽

Inflammatory Factors ◽

Parkinsonian Disorders ◽

Genetic Features ◽

The Brain

Parkinson's disease (PD), dementia with Lewy body (DLB), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and multiple system atrophy (MSA) belong to a group of neurodegenerative diseases called parkinsonian syndromes. They share several clinical, neuropathological and genetic features. Neurodegenerative diseases are characterized by the progressive dysfunction of specific populations of neurons, determining clinical presentation. Neuronal loss is associated with extra- and intracellular accumulation of misfolded proteins. The parkinsonian diseases affect distinct areas of the brain. PD and MSA belong to a group of synucleinopathies that are characterized by the presence of fibrillary aggregates of α-synuclein protein in the cytoplasm of selected populations of neurons and glial cells. PSP is a tauopathy associated with the pathological aggregation of the microtubule associated tau protein. Although PD is common in the world's aging population and has been extensively studied, the exact mechanisms of the neurodegeneration are still not fully understood. Growing evidence indicates that parkinsonian disorders to some extent share a genetic background, with two key components identified so far: the microtubule associated tau protein gene (MAPT) and the α-synuclein gene (SNCA). The main pathways of parkinsonian neurodegeneration described in the literature are the protein and mitochondrial pathways. The factors that lead to neurodegeneration are primarily environmental toxins, inflammatory factors, oxidative stress and traumatic brain injury.

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High-Cholesterol Diet Decreases the Level of Phosphatidylinositol 4,5-Bisphosphate by Enhancing the Expression of Phospholipase C (PLCβ1) in Rat Brain

International Journal of Molecular Sciences ◽

10.3390/ijms21031161 ◽

2020 ◽

Vol 21 (3) ◽

pp. 1161 ◽

Cited By ~ 2

Author(s):

Yoon Sun Chun ◽

Sungkwon Chung

Keyword(s):

Neurodegenerative Diseases ◽

Rat Brain ◽

Phospholipase C ◽

Cultured Cells ◽

Cell Interaction ◽

High Cholesterol Diet ◽

Cholesterol Diet ◽

High Cholesterol ◽

Amyloid Aβ ◽

The Brain

Cholesterol is a critical component of eukaryotic membranes, where it contributes to regulating transmembrane signaling, cell–cell interaction, and ion transport. Dysregulation of cholesterol levels in the brain may induce neurodegenerative diseases, such as Alzheimer’s disease, Parkinson disease, and Huntington disease. We previously reported that augmenting membrane cholesterol level regulates ion channels by decreasing the level of phosphatidylinositol 4,5-bisphosphate (PIP2), which is closely related to β-amyloid (Aβ) production. In addition, cholesterol enrichment decreased PIP2 levels by increasing the expression of the β1 isoform of phospholipase C (PLC) in cultured cells. In this study, we examined the effect of a high-cholesterol diet on phospholipase C (PLCβ1) expression and PIP2 levels in rat brain. PIP2 levels were decreased in the cerebral cortex in rats on a high-cholesterol diet. Levels of PLCβ1 expression correlated with PIP2 levels. However, cholesterol and PIP2 levels were not correlated, suggesting that PIP2 level is regulated by cholesterol via PLCβ1 expression in the brain. Thus, there exists cross talk between cholesterol and PIP2 that could contribute to the pathogenesis of neurodegenerative diseases.

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Novel biochemical properties of the brain ERK kinase PK40erk

Neurobiology of Aging ◽

10.1016/0197-4580(94)92604-2 ◽

1994 ◽

Vol 15 ◽

pp. S37

Keyword(s):

Biochemical Properties ◽

The Brain ◽

Erk Kinase

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A 2.8-Angstrom-Resolution Cryo-Electron Microscopy Structure of Human Parechovirus 3 in Complex with Fab from a Neutralizing Antibody

Journal of Virology ◽

10.1128/jvi.01597-18 ◽

2018 ◽

Vol 93 (4) ◽

Cited By ~ 5

Author(s):

Aušra Domanska ◽

Justin W. Flatt ◽

Joonas J. J. Jukonen ◽

James A. Geraets ◽

Sarah J. Butcher

Keyword(s):

Electron Microscopy ◽

Monoclonal Antibody ◽

High Resolution ◽

Cultured Cells ◽

Human Monoclonal Antibody ◽

Neutralizing Antibody ◽

Molecular Diagnostic ◽

Diagnostic Tools ◽

Human Parechovirus ◽

Cryo Electron Microscopy

ABSTRACTHuman parechovirus 3 (HPeV3) infection is associated with sepsis characterized by significant immune activation and subsequent tissue damage in neonates. Strategies to limit infection have been unsuccessful due to inadequate molecular diagnostic tools for early detection and the lack of a vaccine or specific antiviral therapy. Toward the latter, we present a 2.8-Å-resolution structure of HPeV3 in complex with fragments from a neutralizing human monoclonal antibody, AT12-015, using cryo-electron microscopy (cryo-EM) and image reconstruction. Modeling revealed that the epitope extends across neighboring asymmetric units with contributions from capsid proteins VP0, VP1, and VP3. Antibody decoration was found to block binding of HPeV3 to cultured cells. Additionally, at high resolution, it was possible to model a stretch of RNA inside the virion and, from this, identify the key features that drive and stabilize protein-RNA association during assembly.IMPORTANCEHuman parechovirus 3 (HPeV3) is receiving increasing attention as a prevalent cause of sepsis-like symptoms in neonates, for which, despite the severity of disease, there are no effective treatments available. Structural and molecular insights into virus neutralization are urgently needed, especially as clinical cases are on the rise. Toward this goal, we present the first structure of HPeV3 in complex with fragments from a neutralizing monoclonal antibody. At high resolution, it was possible to precisely define the epitope that, when targeted, prevents virions from binding to cells. Such an atomic-level description is useful for understanding host-pathogen interactions and viral pathogenesis mechanisms and for finding potential cures for infection and disease.

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