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Kon T, Ichimata S, Di Luca DG, Martinez-Valbuena I, Kim A, Yoshida K, Alruwaita AA, Kleiner G, Strafella AP, Forrest SL, Sato C, Rogaeva E, Fox SH, Lang AE, Kovacs GG. Multiple system atrophy with amyloid-β-predominant Alzheimer's disease neuropathologic change. Brain Commun 2024; 6:fcae141. [PMID: 38712319 PMCID: PMC11073746 DOI: 10.1093/braincomms/fcae141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 03/08/2024] [Accepted: 04/15/2024] [Indexed: 05/08/2024] Open
Abstract
Multiple system atrophy is a neurodegenerative disease with α-synuclein pathology predominating in the striatonigral and olivopontocerebellar systems. Mixed pathologies are considered to be of low frequency and mostly comprise primary age-related tauopathy or low levels of Alzheimer's disease-related neuropathologic change. Therefore, the concomitant presence of different misfolded proteins in the same brain region is less likely in multiple system atrophy. During the neuropathological evaluation of 21 consecutive multiple system atrophy cases, we identified four cases exhibiting an unusual discrepancy between high Thal amyloid-β phase and low transentorhinal Braak neurofibrillary tangle stage. We mapped α-synuclein pathology, measured the size and number of glial cytoplasmic inclusions and compared the amyloid-β peptides between multiple system atrophy and Alzheimer's disease. In addition, we performed α-synuclein seeding assay from the affected putamen samples. We performed genetic testing for APOE, MAPT, PSEN1, PSEN2 and APP. We refer to the four multiple system atrophy cases with discrepancy between amyloid-β and tau pathology as 'amyloid-β-predominant Alzheimer's disease neuropathologic change-multiple system atrophy' to distinguish these from multiple system atrophy with primary age-related tauopathy or multiple system atrophy with typical Alzheimer's disease neuropathologic change. As most multiple system atrophy cases with mixed pathologies reported in the literature, these cases did not show a peculiar clinical or MRI profile. Three amyloid-β-predominant Alzheimer's disease neuropathologic change-multiple system atrophy cases were available for genetic testing, and all carried the APOE ɛ4 allele. The extent and severity of neuronal loss and α-synuclein pathology were not different compared with typical multiple system atrophy cases. Analysis of amyloid-β peptides revealed more premature amyloid-β plaques in amyloid-β-predominant Alzheimer's disease neuropathologic change-multiple system atrophy compared with Alzheimer's disease. α-Synuclein seeding amplification assay showed differences in the kinetics in two cases. This study highlights a rare mixed pathology variant of multiple system atrophy in which there is an anatomical meeting point of amyloid-β and α-synuclein, i.e. the striatum or cerebellum. Since biomarkers are entering clinical practice, these cases will be recognized, and the clinicians have to be informed that the prognosis is not necessarily different than in pure multiple system atrophy cases but that the effect of potential α-synuclein-based therapies might be influenced by the co-presence of amyloid-β in regions where α-synuclein also aggregates. We propose that mixed pathologies should be interpreted not only based on differences in the clinical phenotype but also on whether protein depositions regionally overlap, potentially leading to a different response to α-synuclein-targeted therapies.
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Affiliation(s)
- Tomoya Kon
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 0S8, Canada
- Department of Neurology, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Shojiro Ichimata
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 0S8, Canada
- Department of Legal Medicine, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Daniel G Di Luca
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON M5S 1A1, Canada
- Department of Neurology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Ivan Martinez-Valbuena
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 0S8, Canada
| | - Ain Kim
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 0S8, Canada
| | - Koji Yoshida
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 0S8, Canada
- Department of Legal Medicine, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Abdullah A Alruwaita
- Edmund J Safra Program in Parkinson’s Disease and Rossy Program in Progressive Supranuclear Palsy, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada
- Neurology Department, Prince Sultan Military Medical City, Riyadh 11159, Saudi Arabia
| | - Galit Kleiner
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON M5S 1A1, Canada
- Movement Disorders and Spasticity Management Clinic, Pamela and Paul Austin Centre for Neurology and Behavioral Support, Baycrest Centre for Geriatric Care, Toronto, ON M6A 2E1, Canada
| | - Antonio P Strafella
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON M5S 1A1, Canada
- Edmund J Safra Program in Parkinson’s Disease and Rossy Program in Progressive Supranuclear Palsy, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada
| | - Shelley L Forrest
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 0S8, Canada
- Laboratory Medicine Program & Krembil Brain Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Faculty of Medicine, Health and Human Sciences, Dementia Research Centre, Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia
| | - Christine Sato
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 0S8, Canada
| | - Ekaterina Rogaeva
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 0S8, Canada
| | - Susan H Fox
- Edmund J Safra Program in Parkinson’s Disease and Rossy Program in Progressive Supranuclear Palsy, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada
| | - Anthony E Lang
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 0S8, Canada
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON M5S 1A1, Canada
- Edmund J Safra Program in Parkinson’s Disease and Rossy Program in Progressive Supranuclear Palsy, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada
| | - Gabor G Kovacs
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 0S8, Canada
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON M5S 1A1, Canada
- Edmund J Safra Program in Parkinson’s Disease and Rossy Program in Progressive Supranuclear Palsy, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada
- Laboratory Medicine Program & Krembil Brain Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Faculty of Medicine, Health and Human Sciences, Dementia Research Centre, Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
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2
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Ghosh U, Tse E, Shi M, Yang H, Wang F, Merz GE, Prusiner SB, Southworth DR, Condello C. Cryo-EM Structures Reveal Tau Filaments from Down Syndrome Adopt Alzheimer's Disease Fold. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.02.587507. [PMID: 38617229 PMCID: PMC11014571 DOI: 10.1101/2024.04.02.587507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Down Syndrome (DS) is a common genetic condition caused by trisomy of chromosome 21. Among the complex clinical features including musculoskeletal, neurological and cardiovascular disabilities, individuals with DS develop progressive dementia and early onset Alzheimer's Disease (AD). This is attributed to the increased gene dosage of amyloid precursor protein (APP), the formation of self-propagating Aβ and tau prion conformers, and the deposition of neurotoxic Aβ plaques and tau neurofibrillary tangles. Tau amyloid fibrils have previously been established to adopt many distinct conformations across different neurodegenerative conditions. Here we characterized 4 DS cases spanning 36 to 63 years in age by spectral confocal imaging with conformation-specific dyes and cryo-electron microscopy (cryo-EM) to determine structures of isolated tau fibrils. High-resolution structures reveal paired helical (PHF) and straight filament (SF) conformations of tau that are identical to those determined from AD. The PHFs and SFs are made of two C-shaped protofilaments with a cross-β/β-helix motif. Similar to AD, most filaments adopt the PHF form, while a minority (~20%) form SFs. For the youngest individual with no documented dementia samples exhibited sparse tau deposits. To isolate tau for cryo-EM from this challenging sample we employed a novel "affinity grid" method involving a graphene-oxide surface derivatized with anti-tau antibodies. This improved isolation and revealed primarily tau PHFs and a minor population of SSPE type II-like filaments are present at this early age. These findings expand the similarities between AD and DS to the molecular level providing insight into their related pathologies and the potential for targeting common tau filament folds by small molecule therapeutics and diagnostics.
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Affiliation(s)
- Ujjayini Ghosh
- Institute for Neurodegenerative Diseases; University of California, San Francisco; San Francisco, CA 94158, USA
| | - Eric Tse
- Institute for Neurodegenerative Diseases; University of California, San Francisco; San Francisco, CA 94158, USA
| | - Marie Shi
- Institute for Neurodegenerative Diseases; University of California, San Francisco; San Francisco, CA 94158, USA
| | - Hyunjun Yang
- Institute for Neurodegenerative Diseases; University of California, San Francisco; San Francisco, CA 94158, USA
| | - Feng Wang
- Department of Biochemistry and Biophysics, University of California San Francisco; San Francisco, CA, USA
| | - Gregory E. Merz
- Institute for Neurodegenerative Diseases; University of California, San Francisco; San Francisco, CA 94158, USA
- Department of Neurology, University of California San Francisco; San Francisco, CA, USA
| | - Stanley B. Prusiner
- Institute for Neurodegenerative Diseases; University of California, San Francisco; San Francisco, CA 94158, USA
- Department of Neurology, University of California San Francisco; San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California San Francisco; San Francisco, CA, USA
| | - Daniel R. Southworth
- Institute for Neurodegenerative Diseases; University of California, San Francisco; San Francisco, CA 94158, USA
- Department of Biochemistry and Biophysics, University of California San Francisco; San Francisco, CA, USA
| | - Carlo Condello
- Institute for Neurodegenerative Diseases; University of California, San Francisco; San Francisco, CA 94158, USA
- Department of Neurology, University of California San Francisco; San Francisco, CA, USA
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3
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Gaikwad S, Senapati S, Haque MA, Kayed R. Senescence, brain inflammation, and oligomeric tau drive cognitive decline in Alzheimer's disease: Evidence from clinical and preclinical studies. Alzheimers Dement 2024; 20:709-727. [PMID: 37814508 PMCID: PMC10841264 DOI: 10.1002/alz.13490] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 10/11/2023]
Abstract
Aging, tau pathology, and chronic inflammation in the brain play crucial roles in synaptic loss, neurodegeneration, and cognitive decline in tauopathies, including Alzheimer's disease. Senescent cells accumulate in the aging brain, accelerate the aging process, and promote tauopathy progression through their abnormal inflammatory secretome known as the senescence-associated secretory phenotype (SASP). Tau oligomers (TauO)-the most neurotoxic tau species-are known to induce senescence and the SASP, which subsequently promote neuropathology, inflammation, oxidative stress, synaptic dysfunction, neuronal death, and cognitive dysfunction. TauO, brain inflammation, and senescence are associated with heterogeneity in tauopathy progression and cognitive decline. However, the underlying mechanisms driving the disease heterogeneity remain largely unknown, impeding the development of therapies for tauopathies. Based on clinical and preclinical evidence, this review highlights the critical role of TauO and senescence in neurodegeneration. We discuss key knowledge gaps and potential strategies for targeting senescence and TauO to treat tauopathies. HIGHLIGHTS: Senescence, oligomeric Tau (TauO), and brain inflammation accelerate the aging process and promote the progression of tauopathies, including Alzheimer's disease. We discuss their role in contributing to heterogeneity in tauopathy and cognitive decline. We highlight strategies to target senescence and TauO to treat tauopathies while addressing key knowledge gaps.
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Affiliation(s)
- Sagar Gaikwad
- The Mitchell Center for Neurodegenerative Diseasesand Department of NeurologyUniversity of Texas Medical BranchGalvestonTexasUSA
| | - Sudipta Senapati
- The Mitchell Center for Neurodegenerative Diseasesand Department of NeurologyUniversity of Texas Medical BranchGalvestonTexasUSA
| | - Md. Anzarul Haque
- The Mitchell Center for Neurodegenerative Diseasesand Department of NeurologyUniversity of Texas Medical BranchGalvestonTexasUSA
| | - Rakez Kayed
- The Mitchell Center for Neurodegenerative Diseasesand Department of NeurologyUniversity of Texas Medical BranchGalvestonTexasUSA
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4
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Louros N, Schymkowitz J, Rousseau F. Mechanisms and pathology of protein misfolding and aggregation. Nat Rev Mol Cell Biol 2023; 24:912-933. [PMID: 37684425 DOI: 10.1038/s41580-023-00647-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2023] [Indexed: 09/10/2023]
Abstract
Despite advances in machine learning-based protein structure prediction, we are still far from fully understanding how proteins fold into their native conformation. The conventional notion that polypeptides fold spontaneously to their biologically active states has gradually been replaced by our understanding that cellular protein folding often requires context-dependent guidance from molecular chaperones in order to avoid misfolding. Misfolded proteins can aggregate into larger structures, such as amyloid fibrils, which perpetuate the misfolding process, creating a self-reinforcing cascade. A surge in amyloid fibril structures has deepened our comprehension of how a single polypeptide sequence can exhibit multiple amyloid conformations, known as polymorphism. The assembly of these polymorphs is not a random process but is influenced by the specific conditions and tissues in which they originate. This observation suggests that, similar to the folding of native proteins, the kinetics of pathological amyloid assembly are modulated by interactions specific to cells and tissues. Here, we review the current understanding of how intrinsic protein conformational propensities are modulated by physiological and pathological interactions in the cell to shape protein misfolding and aggregation pathology.
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Affiliation(s)
- Nikolaos Louros
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium
- Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Joost Schymkowitz
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
- Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
| | - Frederic Rousseau
- Switch Laboratory, VIB-KU Leuven Center for Brain & Disease Research, Leuven, Belgium.
- Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium.
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5
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Ichimata S, Martinez-Valbuena I, Lee S, Li J, Karakani AM, Kovacs GG. Distinct Molecular Signatures of Amyloid-Beta and Tau in Alzheimer's Disease Associated with Down Syndrome. Int J Mol Sci 2023; 24:11596. [PMID: 37511361 PMCID: PMC10380583 DOI: 10.3390/ijms241411596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/11/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Limited comparative data exist on the molecular spectrum of amyloid-beta (Aβ) and tau deposition in individuals with Down syndrome (DS) and sporadic Alzheimer's disease (sAD). We assessed Aβ and tau deposition severity in the temporal lobe and cerebellum of ten DS and ten sAD cases. Immunohistochemistry was performed using antibodies against eight different Aβ epitopes (6F/3D, Aβ38, Aβ39, Aβ40, Aβ42, Aβ43, pyroglutamate Aβ at third glutamic acid (AβNp3E), phosphorylated- (p-)Aβ at 8th serine (AβpSer8)), and six different pathological tau epitopes (p-Ser202/Thr205, p-Thr231, p-Ser396, Alz50, MC1, GT38). Findings were evaluated semi-quantitatively and quantitatively using digital pathology. DS cases had significantly higher neocortical parenchymal deposition (Aβ38, Aβ42, and AβpSer8), and cerebellar parenchymal deposition (Aβ40, Aβ42, AβNp3E, and AβpSer8) than sAD cases. Furthermore, DS cases had a significantly larger mean plaque size (6F/3D, Aβ42, AβNp3E) in the temporal lobe, and significantly greater deposition of cerebral and cerebellar Aβ42 than sAD cases in the quantitative analysis. Western blotting corroborated these findings. Regarding tau pathology, DS cases had significantly more severe cerebral tau deposition than sAD cases, especially in the white matter (p-Ser202/Thr205, p-Thr231, Alz50, and MC1). Greater total tau deposition in the white matter (p-Ser202/Thr205, p-Thr231, and Alz50) of DS cases was confirmed by quantitative analysis. Our data suggest that the Aβ and tau molecular signatures in DS are distinct from those in sAD.
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Affiliation(s)
- Shojiro Ichimata
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 2S8, Canada; (S.I.); (I.M.-V.); (S.L.); (J.L.); (A.M.K.)
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A1, Canada
- Department of Legal Medicine, Faculty of Medicine, University of Toyama, Toyama 930-8555, Japan
| | - Ivan Martinez-Valbuena
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 2S8, Canada; (S.I.); (I.M.-V.); (S.L.); (J.L.); (A.M.K.)
| | - Seojin Lee
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 2S8, Canada; (S.I.); (I.M.-V.); (S.L.); (J.L.); (A.M.K.)
| | - Jun Li
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 2S8, Canada; (S.I.); (I.M.-V.); (S.L.); (J.L.); (A.M.K.)
| | - Ali M. Karakani
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 2S8, Canada; (S.I.); (I.M.-V.); (S.L.); (J.L.); (A.M.K.)
| | - Gabor G. Kovacs
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, ON M5T 2S8, Canada; (S.I.); (I.M.-V.); (S.L.); (J.L.); (A.M.K.)
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A1, Canada
- Edmond J. Safra Program in Parkinson’s Disease, Rossy Program for PSP Research and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada
- Laboratory Medicine Program, Krembil Brain Institute, University Health Network, Toronto, ON M5G 2C4, Canada
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6
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Merz GE, Chalkley MJ, Tan SK, Tse E, Lee J, Prusiner SB, Paras NA, DeGrado WF, Southworth DR. Stacked binding of a PET ligand to Alzheimer's tau paired helical filaments. Nat Commun 2023; 14:3048. [PMID: 37236970 PMCID: PMC10220082 DOI: 10.1038/s41467-023-38537-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
Accumulation of filamentous aggregates of tau protein in the brain is a pathological hallmark of Alzheimer's disease (AD) and many other neurodegenerative tauopathies. The filaments adopt disease-specific cross-β amyloid conformations that self-propagate and are implicated in neuronal loss. Development of molecular diagnostics and therapeutics is of critical importance. However, mechanisms of small molecule binding to the amyloid core is poorly understood. We used cryo-electron microscopy to determine a 2.7 Å structure of AD patient-derived tau paired-helical filaments bound to the PET ligand GTP-1. The compound is bound stoichiometrically at a single site along an exposed cleft of each protofilament in a stacked arrangement matching the fibril symmetry. Multiscale modeling reveals pi-pi aromatic interactions that pair favorably with the small molecule-protein contacts, supporting high specificity and affinity for the AD tau conformation. This binding mode offers critical insight into designing compounds to target different amyloid folds found across neurodegenerative diseases.
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Affiliation(s)
- Gregory E Merz
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, USA
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Matthew J Chalkley
- Department of Pharmaceutical Chemistry, Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Sophia K Tan
- Department of Pharmaceutical Chemistry, Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Eric Tse
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, USA
| | - Joanne Lee
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, USA
| | - Stanley B Prusiner
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, USA
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Nick A Paras
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, USA
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - William F DeGrado
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, USA
- Department of Pharmaceutical Chemistry, Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Daniel R Southworth
- Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, USA.
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA.
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7
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Lee M, Yau WM, Louis JM, Tycko R. Structures of brain-derived 42-residue amyloid-β fibril polymorphs with unusual molecular conformations and intermolecular interactions. Proc Natl Acad Sci U S A 2023; 120:e2218831120. [PMID: 36893281 PMCID: PMC10089215 DOI: 10.1073/pnas.2218831120] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 02/04/2023] [Indexed: 03/11/2023] Open
Abstract
Fibrils formed by the 42-residue amyloid-β peptide (Aβ42), a main component of amyloid deposits in Alzheimer's disease (AD), are known to be polymorphic, i.e., to contain multiple possible molecular structures. Previous studies of Aβ42 fibrils, including fibrils prepared entirely in vitro or extracted from brain tissue and using solid-state NMR (ssNMR) or cryogenic electron microscopy (cryo-EM) methods, have found polymorphs with differences in amino acid sidechain orientations, lengths of structurally ordered segments, and contacts between cross-β subunit pairs within a single filament. Despite these differences, Aβ42 molecules adopt a common S-shaped conformation in all previously described high-resolution Aβ42 fibril structures. Here we report two cryo-EM-based structures of Aβ42 fibrils that are qualitatively different, in samples derived from AD brain tissue by seeded growth. In type A fibrils, residues 12 to 42 adopt a ν-shaped conformation, with both intra-subunit and intersubunit hydrophobic contacts to form a compact core. In type B fibrils, residues 2 to 42 adopt an υ-shaped conformation, with only intersubunit contacts and internal pores. Type A and type B fibrils have opposite helical handedness. Cryo-EM density maps and molecular dynamics simulations indicate intersubunit K16-A42 salt bridges in type B fibrils and partially occupied K28-A42 salt bridges in type A fibrils. The coexistence of two predominant polymorphs, with differences in N-terminal dynamics, is supported by ssNMR data, as is faithful propagation of structures from first-generation to second-generation brain-seeded Aβ42 fibril samples. These results demonstrate that Aβ42 fibrils can exhibit a greater range of structural variations than seen in previous studies.
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Affiliation(s)
- Myungwoon Lee
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD20892-0520
| | - Wai-Ming Yau
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD20892-0520
| | - John M. Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD20892-0520
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD20892-0520
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8
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Yang H, Yuan P, Wu Y, Shi M, Caro CD, Tengeiji A, Yamanoi S, Inoue M, DeGrado WF, Condello C. EMBER multi-dimensional spectral microscopy enables quantitative determination of disease- and cell-specific amyloid strains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526692. [PMID: 36778268 PMCID: PMC9915571 DOI: 10.1101/2023.02.01.526692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
In neurodegenerative diseases proteins fold into amyloid structures with distinct conformations (strains) that are characteristic of different diseases. However, there is a need to rapidly identify amyloid conformations in situ . Here we use machine learning on the full information available in fluorescent excitation/emission spectra of amyloid binding dyes to identify six distinct different conformational strains in vitro , as well as Aβ deposits in different transgenic mouse models. Our EMBER (excitation multiplexed bright emission recording) imaging method rapidly identifies conformational differences in Aβ and tau deposits from Down syndrome, sporadic and familial Alzheimer's disease human brain slices. EMBER has in situ identified distinct conformational strains of tau inclusions in astrocytes, oligodendrocytes, and neurons from Pick's disease. In future studies, EMBER should enable high-throughput measurements of the fidelity of strain transmission in cellular and animal neurodegenerative diseases models, time course of amyloid strain propagation, and identification of pathogenic versus benign strains. Significance In neurodegenerative diseases proteins fold into amyloid structures with distinct conformations (strains) that are characteristic of different diseases. There is a need to rapidly identify these amyloid conformations in situ . Here we use machine learning on the full information available in fluorescent excitation/emission spectra of amyloid binding dyes to identify six distinct different conformational strains in vitro , as well as Aβ deposits in different transgenic mouse models. Our imaging method rapidly identifies conformational differences in Aβ and tau deposits from Down syndrome, sporadic and familial Alzheimer's disease human brain slices. We also identified distinct conformational strains of tau inclusions in astrocytes, oligodendrocytes, and neurons from Pick's disease. These findings will facilitate the identification of pathogenic protein aggregates to guide research and treatment of protein misfolding diseases.
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Affiliation(s)
- Hyunjun Yang
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143
- Department of Pharmaceutical Chemistry, Cardiovascular Research Institute, University of California, San Francisco, CA 94158
| | - Peng Yuan
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143
| | - Yibing Wu
- Department of Pharmaceutical Chemistry, Cardiovascular Research Institute, University of California, San Francisco, CA 94158
| | - Marie Shi
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143
| | - Christoffer D Caro
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143
| | | | | | | | - William F DeGrado
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143
- Department of Pharmaceutical Chemistry, Cardiovascular Research Institute, University of California, San Francisco, CA 94158
| | - Carlo Condello
- Institute for Neurodegenerative Diseases, University of California, San Francisco, CA 94143
- Department of Neurology, University of California, San Francisco, CA 94143
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9
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Biochemical Discrimination of the Down Syndrome-Related Metabolic and Oxidative/Nitrosative Stress Alterations from the Physiologic Age-Related Changes through the Targeted Metabolomic Analysis of Serum. Antioxidants (Basel) 2022; 11:antiox11061208. [PMID: 35740106 PMCID: PMC9219806 DOI: 10.3390/antiox11061208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/09/2022] [Accepted: 06/16/2022] [Indexed: 12/02/2022] Open
Abstract
Down Syndrome (DS) is a neurodevelopmental disorder that is characterized by an accelerated aging process, frequently associated with the development of Alzheimer’s disease (AD). Previous studies evidenced that DS patients have various metabolic anomalies, easily measurable in their serum samples, although values that were found in DS patients were compared with those of age-matched non-DS patients, thus hampering to discriminate the physiologic age-related changes of serum metabolites from those that are truly caused by the pathologic processes associated with DS. In the present study we performed a targeted metabolomic evaluation of serum samples from DS patients without dementia of two age classes (Younger DS Patients, YDSP, aging 20–40 years; Aged DS Patients, ADSP, aging 41–60 years), comparing the results with those that were obtained in two age classes of non-DS patients (Younger non-DS Patients, YnonDSP, aging 30–60 years; Aged-nonDS Patients, AnonDSP, aging 75–90 years). Of the 36 compounds assayed, 30 had significantly different concentrations in Pooled non-DS Patients (PnonDSP), compared to Pooled DS Patients (PDSP). Age categorization revealed that 11/30 compounds were significantly different in AnonDSP, compared to YnonDSP, indicating physiologic, age-related changes of their circulating concentrations. A comparison between YDSP and ADSP showed that 19/30 metabolites had significantly different values from those found in the corresponding classes of non-DS patients, strongly suggesting pathologic, DS-associated alterations of their serum levels. Twelve compounds selectively and specifically discriminated PnonDSP from PDSP, whilst only three discriminated YDSP from ADSP. The results allowed to determine, for the first time and to the best of our knowledge, the true, age-independent alterations of metabolism that are measurable in serum and attributable only to DS. These findings may be of high relevance for better strategies (pharmacological, nutritional) aiming to specifically target the dysmetabolism and decreased antioxidant defenses that are associated with DS.
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