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Goedert, M.

Publications and source records attributed to Goedert, M..

At least 19 recordsLinked to original sources

Templated paired helical filament formation and tau fold-dependent inclusion morphologies in primary neurons

Neurodegenerative tauopathies are characterized by the abnormal assembly of tau into amyloid filaments with distinct, disease-specific folds. These filaments are proposed to spread in a prion-like manner, thus underlying the progression of pathology in diseased brains. A prediction of this hypothesis is that tau filaments will induce progeny filaments identical to the input seed material, yet cellular models of templated tau assembly have failed to fully recapitulate brain-derived filament structures. Here, we show that mixed primary mouse cortical neurons overexpressing full-length human tau via adeno-associated virus transduction propagate Alzheimer's disease paired helical filaments upon exposure to human brain-derived seeds. Using minimal tags and core mutations, we were able to unambiguously differentiate induced aggregates from the original seeds. Super-resolution microscopy and live-cell imaging revealed progressive inclusion formation in neurons. Moreover, seeding primary neurons with brain extracts from individuals with Pick's disease, corticobasal degeneration and progressive supranuclear palsy induced the formation of morphologically distinct inclusions. Together, these findings establish that primary neurons provide an environment for the faithful propagation of paired helical filaments and show that tau filament folds dictate higher-order inclusion morphologies within neurons.

neuroscience↗

Templated seeding induces the formation of Alzheimer paired helical tau filaments in human brain organoids

The prion concept postulates that seeded aggregation results in the recruitment of soluble protein monomers and their assembly into amyloid filaments with the same structures as those of the seeds. Here we show that this concept applies to tau filaments formed in cortical organoids obtained from human iPSCs of control subjects. Tau seeds were extracted from the frontal cortex of individuals with Alzheimer disease. When added to human cortical organoids expressing endogenous levels of three-repeat tau, they gave rise to filaments of three-repeat tau whose formation required endogenous tau expression. By cryo-EM, these seeded tau filaments were identical to the paired helical filaments of the seeds. This novel finding demonstrates the faithful templated seeding of tau in human nerve cells expressing endogenous levels of tau and opens the way to studying the mechanisms of paired helical filament formation and their downstream effects in a human system amenable to genetic modification.

neuroscience↗

Reduced tubulin polyglutamylation perturbs neuronal function and causes late-onset neurodegeneration

Microtubules are essential for neuronal functions and are involved in many neurodegenerative disorders. A posttranslational modification (PTM) of neuronal microtubules, polyglutamylation, was shown to control cargo transport, Tau protein binding to microtubules and to induce early-onset neurodegeneration when exceeding physiological levels. To determine the physiological importance of this PTM, we characterised mouse models with reduced polyglutamylation. We demonstrate that these mice develop late-onset atrophy of the olfactory bulb and frontal cortex, progressively reduced dendritic spine density, and deficits in olfaction, memory, and cognitive control. This indicates an important role of polyglutamylation in neuronal function. To test whether the observed defects are linked to neurodegeneration, we combined mice with reduced polyglutamylation with a transgenic model for tauopathy. Strikingly, reduced polyglutamylation accelerated the premature demise of mice transgenic for human Tau carrying the P301S mutation. Our work thus reveals key roles of microtubule polyglutamylation in neuronal function with implications for late-onset neurodegeneration linked to Tau pathology.

neuroscience↗

Dimerisation and twist reversal of the Lewy fold in α-synuclein mutants with Parkinson's disease and dementia

Dominantly inherited missense and gene dosage mutations in SNCA, the -synuclein gene, cause familial forms of Parkinsons disease and dementia. Here we report the structures of -synuclein filaments from the brains of such individuals. Pathogenic mutations A53T and G51D in SNCA give rise to singlets and doublets of the Lewy fold with a left-handed helical twist in the absence of a peptide-like density for island A. By contrast, filaments from the non-pathogenic variant H50Q consist of singlets of the right-handed Lewy fold with a density for island A, like filaments of wild-type -synuclein. The structures of filaments from homozygous mice transgenic for human mutant A53T -synuclein (line M83) are unlike those from human brains. They are more similar to the multiple system atrophy folds than to the Lewy fold of Parkinsons disease, Parkinsons disease dementia and dementia with Lewy bodies

biophysics↗

Prion-like transmission of human tau strains in the mouse brain

Most neurodegenerative diseases are believed to spread through the brain by prion-like mechanisms, where filamentous protein assemblies self-propagate by templated seeding 1. Distinct conformations of amyloid filaments are thought to provide the physical basis for the strains that lead to different diseases 2. However, a central pillar of the prion hypothesis, that strains retain their structural identity upon transmission, has not been demonstrated. Here we show that the injection of tau filaments from the brains of individuals with Alzheimers disease or corticobasal degeneration into the brains of wildtype mice leads to the seeded assembly of amyloid filaments made of mouse tau with the same structures as those of the seeds. Thereby, we establish that, like prion strains, tau filaments propagate through templated seeding, and that the mouse is a suitable model to study the molecular mechanisms by which distinct tau folds drive disease-specific pathology in the brain.

neuroscience↗

The Pick fold in tau filaments from human MAPT mutants

Mutations in MAPT, the tau gene, give rise to forms of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17T), with abundant filamentous tau inclusions in brain cells. Some mutations that encode missense and deletion variants can give rise to a clinical picture of Picks disease and filaments made of three-repeat tau. Here we report the electron cryo-microscopy (cryo-EM) structures of tau filaments from individuals with MAPT mutations D252V, G272V, S320F and {Delta}G389-I392. The two-layered Pick fold was present in the individuals with mutations D252V and {Delta}G389-I392. By contrast, mutations G272V and S320F gave rise to a more open variant of the Pick fold, with residues 272-341 rotated by 20-25{degrees} with respect to the rest of the structure. These findings show that missense mutations within the filament core can modify the Pick fold, generating closely related structural variants. In addition, we were able to reconstitute the Pick fold and some of its variants using seeded assembly with recombinant 0N3R tau carrying 12 serine or threonine to aspartate substitutions (PAD12) and missense mutations D252V, G272V or S320F. This work provides a foundation for the development of structure-based diagnostic and therapeutic approaches.

biophysics↗

Twelve phosphomimetic mutations induce the assembly of recombinant full-length human tau into paired helical filaments

The assembly of tau into amyloid filaments is associated with more than twenty neurodegenerative diseases, collectively termed tauopathies. Cryo-EM structures of brain-derived tau filaments revealed that specific structures define different diseases, triggering a quest for the development of experimental model systems that replicate the structures of disease. Here, we describe twelve phosphomimetic, serine/threonine to aspartate, mutations in tau, which we termed PAD12, that collectively induce the in vitro assembly of full-length tau into filaments with the same structure as that of paired helical filaments extracted from the brains of individuals with Alzheimers disease. Solution-state nuclear magnetic resonance spectroscopy suggests that phosphomimetic mutations in the carboxy-terminal domain of tau may facilitate filament formation by disrupting an intramolecular interaction between two IVYK motifs. PAD12 tau can be used for both nucleation-dependent and multiple rounds of seeded assembly in vitro, as well as for the seeding of tau biosensor cells. PAD12 tau can be assembled into paired helical filaments under various shaking conditions, with the resulting filaments being stable for extended periods of time. They can be labelled with fluorophores and biotin. Tau filaments extracted from the brains of individuals with Alzheimers disease have been known to be made of hyperphosphorylated and abnormally phosphorylated full-length tau, but it was not known if the presence of this post-translational modification is more than a mere correlation. Our findings suggest that hyperphosphorylation of tau may be sufficient for the formation of the Alzheimer tau fold. PAD12 tau will be a useful tool for the study of molecular mechanisms of neurodegeneration.

neuroscience↗

Novel tau filament folds in individuals with MAPT mutations P301L and P301T

Mutations in MAPT, the microtubule-associated protein tau gene, give rise to cases of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) with abundant filamentous tau inclusions in brain cells. Individuals with pathological MAPT variants exhibit behavioural changes, cognitive impairment and signs of parkinsonism. Missense mutations of residue P301, which are the most common MAPT mutations associated with FTDP-17, give rise to the assembly of mutant four-repeat tau into filamentous inclusions, in the absence of extracellular deposits. Here we report the cryo-EM structures of tau filaments from five individuals belonging to three unrelated families with mutation P301L and from one individual belonging to a family with mutation P301T. A novel three-lobed tau fold resembling the two-layered tau fold of Picks disease was present in all cases with the P301L tau mutation. Two different tau folds were found in the case with mutation P301T, the less abundant of which was a variant of the three-lobed fold. The major P301T tau fold was V-shaped, with partial similarity to the four-layered tau folds of corticobasal degeneration and argyrophilic grain disease. These findings suggest that FTDP-17 with mutations in P301 should be considered distinct inherited tauopathies and that model systems with these mutations should be used with caution in the study of sporadic tauopathies.

neuroscience↗

Tau filaments with the Alzheimer fold in cases with MAPT mutations V337M and R406W

Frontotemporal dementia (FTD) and Alzheimers disease are the most common forms of early-onset dementia. Dominantly inherited mutations in MAPT, the microtubule-associated protein tau gene, cause FTD and parkinsonism linked to chromosome 17 (FTDP-17). Individuals with FTDP-17 develop abundant filamentous tau inclusions in brain cells. Here we used electron cryo-microscopy to determine the structures of tau filaments from the brains of individuals with MAPT mutations V337M and R406W. Both mutations gave rise to tau filaments with the Alzheimer fold, which consisted of paired helical filaments in all V337M and R406W cases and of straight filaments in two V337M cases. We also identified a new assembly of the Alzheimer fold into triple tau filaments in a V337M case. Filaments assembled from recombinant tau(297-391) with mutation V337M had the Alzheimer fold and showed an increased rate of assembly.

biophysics↗

TAU FILAMENTS WITH THE CHRONIC TRAUMATIC ENCEPHALOPATHY FOLD IN A CASE OF VACUOLAR TAUOPATHY WITH VCP MUTATION D395G

Dominantly inherited mutation D395G in the gene encoding valosin-containing protein causes vacuolar tauopathy, a type of behavioural-variant frontotemporal dementia, with marked vacuolation and abundant filamentous tau inclusions made of all six brain isoforms. Here we report that tau inclusions were concentrated in layers II/III of the frontotemporal cortex in a case of vacuolar tauopathy. By electron cryo-microscopy, tau filaments had the chronic traumatic encephalopathy (CTE) fold. Tau inclusions of vacuolar tauopathy share this cortical location and the tau fold with CTE, subacute sclerosing panencephalitis and amyotrophic lateral sclerosis/parkinsonism-dementia complex, which are believed to be environmentally induced. Vacuolar tauopathy is the first inherited disease with the CTE tau fold.

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Cryo-EM structures of Aβ40 filaments from the leptomeninges of individuals with Alzheimer's disease and cerebral amyloid angiopathy

We used electron cryo-microscopy (cryo-EM) to determine the structures of A{beta}40 filaments from the leptomeninges of individuals with Alzheimers disease and cerebral amyloid angiopathy. In agreement with previously reported structures, which were solved to a resolution of 4.4 [A], we found three types of filaments. However, our new structures, solved to a resolution of 2.4 [A] resolution, revealed differences in the sequence assignment that redefine the fold of A{beta}40 peptides and their interactions. Filaments are made of pairs of protofilaments, the ordered core of which comprises D1-G38. The different filament types comprise one, two or three protofilament pairs. In each pair, residues H14-G37 of both protofilaments adopt an extended conformation and pack against each other in an anti-parallel fashion, held together by hydrophobic interactions and hydrogen bonds between main chains and side chains. Residues D1-H13 fold back on the adjacent parts of their own chains through both polar and non-polar interactions. There are also several additional densities of unknown identity. Sarkosyl extraction and aqueous extraction gave the same structures. By cryo-EM, parenchymal deposits of A{beta}42 and blood vessel deposits of A{beta}40 have distinct structures, supporting the view that Alzheimers disease and cerebral amyloid angiopathy are different A{beta} proteinopathies.

neuroscience↗

Cryo-EM structures of Tau filaments from the brains of mice transgenic for human mutant P301S Tau

Mice transgenic for human mutant P301S tau are widely used as models for human tauopathies. They develop neurodegeneration and abundant filamentous inclusions made of human mutant four-repeat tau. Here we used electron cryo-microscopy (cryo-EM) to determine the structures of tau filaments from the brains of Tg2541 and PS19 mice. Both lines express human P301S tau (0N4R for Tg2541 and 1N4R for PS19) on mixed genetic backgrounds and downstream of different promoters (murine Thy1 for Tg2541 and murine Prnp for PS19). The structures of tau filaments from Tg2541 and PS19 mice differ from each other and those of tau filaments from human brains. However, they share a substructure at the junction of repeats 2 and 3, which comprises residues I297-V312 of tau and includes the P301S mutation. The filament core from the brainstem of Tg2541 mice consists of residues K274-H329 of tau and two disconnected protein densities. Two non-proteinaceous densities are also in evidence. The filament core from the cerebral cortex of line PS19 extends from residues G271-P364 of tau. One strong non-proteinaceous density is also present. Unlike the tau filaments from human brains, the sequences following repeat 4 are missing from the cores of tau filaments from the brains of Tg2541 and PS19 mice.

neuroscience↗

Disease-specific tau filaments assemble via polymorphic intermediates

Intermediate species in the assembly of amyloid filaments are believed to play a central role in neurodegenerative diseases and may constitute important targets for therapeutic intervention. However, structural information about intermediate species has been scarce and the molecular mechanisms by which amyloids assemble remain largely unknown. Here, we use time-resolved electron cryo-microscopy (cryo-EM) to study the in vitro assembly of recombinant truncated tau (amino acids 297-391) into paired helical filaments of Alzheimers disease or into filaments of chronic traumatic encephalopathy. We report the formation of a shared first intermediate amyloid (FIA), with an ordered core comprising amino acids 302-316. Nuclear magnetic resonance indicates that the same amino acids adopt rigid, {beta}-strand-like conformations in monomeric tau. At later time points, the FIAs disappear and we observe many different intermediate amyloid filaments, with structures that depend on the reaction conditions. At the end of both reactions, most intermediate amyloids disappear and filaments with the same ordered cores as those from human brains remain. Our results provide structural insights into the processes of primary and secondary nucleation of amyloid assembly, with implications for the design of novel therapies.

biophysics↗

Tau Filaments from Amyotrophic Lateral Sclerosis/Parkinsonism-Dementia Complex (ALS/PDC) adopt the CTE Fold

The amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC) of the island of Guam and the Kii peninsula of Japan is a fatal neurodegenerative disease of unknown cause that is characterised by the presence of abundant filamentous tau inclusions in brains and spinal cords. Here we used electron cryo-microscopy (cryo-EM) to determine the structures of tau filaments from the cerebral cortex of three cases of ALS/PDC from Guam and eight cases from Kii, as well as from the spinal cord of two of the Guam cases. Tau filaments had the chronic traumatic encephalopathy (CTE) fold, with variable amounts of Type I and Type II filaments. Paired helical tau filaments were also found in two Kii cases. We also identified a novel Type III CTE tau filament, where protofilaments pack against each other in an anti-parallel fashion. ALS/PDC is the third known tauopathy with CTE-type filaments and abundant tau inclusions in cortical layers II/III, the others being CTE and subacute sclerosing panencephalitis. Because these tauopathies are believed to have environmental causes, our findings support the hypothesis that ALS/PDC is caused by exogenous factors. SIGNIFICANCEA neurodegenerative disease of unknown cause on the island of Guam and the Kii peninsula of Japan has been widely studied, because patients can suffer from the combined symptoms of motor neuron disease, parkinsonism and dementia. Abnormal filamentous inclusions made of tau protein characterise this amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC) and their formation closely correlates with neurodegeneration. Here we have used electron cryo-microscopy (cryo-EM) to show that tau filaments from ALS/PDC are identical to those from chronic traumatic encephalopathy (CTE), a disease caused by repetitive head impacts or blast waves. CTE tau filaments are also found in subacute sclerosing panencephalitis, which is a rare consequence of measles infection. ALS/PDC may therefore also be caused by environmental factors.

neuroscience↗

Cryo-EM structures of tau filaments from SH-SY5Y cells seeded with brain extracts from cases of Alzheimer's disease and corticobasal degeneration

The formation of amyloid filaments through templated seeding is believed to underlie the propagation of pathology in most human neurodegenerative diseases. A widely used model system to study this process is to seed amyloid filament formation in cultured cells using human brain extracts. Here, we report the electron cryo-microscopy (cryo-EM) structures of tau filaments from undifferentiated seeded SH-SY5Y cells, that transiently expressed N-terminally HA-tagged 1N3R or 1N4R human tau, using brain extracts from individuals with AD or CBD. Although the resulting filament structures differed from those of the brain seeds, some degree of structural templating was observed. Studying templated seeding in cultured cells, and determining the structures of the resulting filaments, can thus provide insights into the cellular aspects underlying neurodegenerative diseases.

neuroscience↗

Identical tau filaments in subacute sclerosing panencephalitis and chronic traumatic encephalopathy

Subacute sclerosing panencephalitis (SSPE) occurs in some individuals after measles infection, following a symptom-free period of several years. It resembles chronic traumatic encephalopathy (CTE), which happens after repetitive head impacts or exposure to blast waves, following a symptom-free period. As in CTE, when present, the neurofibrillary changes of SSPE are concentrated in superficial cortical layers. Here we used electron cryo-microscopy of tau filaments from two cases of SSPE to show that the tau folds of SSPE and CTE are identical. Two types of filaments were each made of two identical protofilaments with an extra density in the {beta}-helix region. Like in CTE, the vast majority of tau filaments were Type I, with a minority of Type II filaments. These findings suggest that the CTE tau fold can be caused by different environmental insults, which may be linked by inflammatory changes.

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Cryo-EM structures of chronic traumatic encephalopathy tau filaments with PET ligand flortaucipir

Positron emission tomography (PET) imaging allows monitoring the progression of amyloid aggregation in the living brain. [18F]-Flortaucipir is the only approved PET tracer compound for the visualisation of tau aggregation. Here, we describe cryo-EM experiments on tau filaments in the presence and absence of flortaucipir. We used tau filaments isolated from the brain of an individual with Alzheimers disease (AD), and from the brain of an individual with primary age-related tauopathy (PART) with a co-pathology of chronic traumatic encephalopathy (CTE). Unexpectedly, we were unable to visualise additional cryo-EM density for flortaucipir for AD paired helical or straight filaments (PHFs or SFs), but we did observe density for flortaucipir binding to CTE Type I filaments from the case with PART. In the latter, flortaucipir binds in a 1:1 molecular stoichiometry with tau, adjacent to lysine 353 and aspartate 358. By adopting a tilted geometry with respect to the helical axis, the 4.7 [A] distance between neighbouring tau monomers is reconciled with the 3.5 [A] distance consistent with {pi}-{pi}-stacking between neighbouring molecules of flortaucipir.

neuroscience↗

New SNCA mutation and structures of α-synuclein filaments from juvenile-onset synucleinopathy

A 21-nucleotide duplication in one allele of SNCA was identified in a previously described disease with abundant -synuclein inclusions that we now call juvenile-onset synucleinopathy (JOS). Both wild-type -synuclein and its insertion mutant containing seven additional residues (MAAAEKT) after residue 22 were present in sarkosyl-insoluble material that was extracted from frontal cortex of the individual with JOS and examined by electron cryo-microscopy. The structures of JOS filaments, comprising either a single protofilament, or a pair of protofilaments, revealed a new -synuclein fold that differs from the folds of Lewy body diseases and multiple system atrophy (MSA). The JOS fold consists of a compact core, the sequence of which (residues 36-100 of wild-type -synuclein) is unaffected by the mutation, and two disconnected density islands (A and B) of mixed sequences. There is a non-proteinaceous cofactor bound between the core and island A. The JOS fold resembles the common substructure of MSA type I and type II dimeric filaments, with its core segment approximating the C-terminal body of MSA protofilaments B and its islands mimicking the N-terminal arm of MSA protofilaments A. The partial similarity of JOS and MSA folds extends to the locations of their cofactor-binding sites. Our findings provide insight into a likely mechanism of JOS fibrillation in which mutant -synuclein of 147 amino acids forms a nucleus with the JOS fold, around which wild-type and mutant proteins assemble during elongation.

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