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Jana AK, Güven Ö, Yaşar F. The stability and dynamics of the Aβ40/Aβ42 interlaced mixed fibrils. J Biomol Struct Dyn 2023:1-14. [PMID: 37964619 DOI: 10.1080/07391102.2023.2280765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 11/01/2023] [Indexed: 11/16/2023]
Abstract
The accumulation of fibrillar amyloid-β (Aβ) aggregates in the brain, predominantly comprising 40- and 42-residue amyloid-β (Aβ40 and Aβ42), is a major pathological hallmark of Alzheimer's disease (AD). Aβ40 and Aβ42 naturally coexist in the brain under normal physiological conditions, and their interplay is generally considered to be a critical factor in the progression of AD. In addition to forming homogeneous oligomers and fibrils, Aβ40 and Aβ42 are also reported to co-assemble into hetero-oligomers and interlaced mixed fibrils, as evidenced by solid-state nuclear magnetic resonance spectroscopy (NMR), high molecular weight mass spectrometry and cross-seeding experiments. However, the exact molecular mechanisms underlying these processes remain unclear. In this study, we have used a recently resolved structurally uniform 1:1 mixture of Aβ40/Aβ42 interlaced mixed fibril as a prototype to gain insights into the molecular-level interactions between Aβ40 and Aβ42. We employed fully atomistic molecular dynamics simulation and compared the results with a homogeneous U-shaped Aβ40 fibrillar model. Our simulations using two different force fields provide conclusive evidence that the Aβ40/Aβ42 interlaced mixed fibril is energetically more favorable than the homogeneous Aβ40 fibrillar model. Furthermore, we also show that the increase in stability observed in the mixed model stems primarily from the packing interfaces and the stacking interfaces between C-termini. Our simulation results provide valuable mechanistic insights that are not readily accessible in experiment and could have significant implications for both the pathogenesis of AD and the development of current therapeutic strategies.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Asis K Jana
- Department of Microbiology and Biotechnology, Sister Nivedita University, Kolkata, West Bengal, India
| | - Özgür Güven
- Department of Physics Engineering, Hacettepe University, Ankara, Türkiye
| | - Fatih Yaşar
- Department of Physics Engineering, Hacettepe University, Ankara, Türkiye
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2
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Kumar M, Ivanova MI, Ramamoorthy A. Non-micellar ganglioside GM1 induces an instantaneous conformational change in Aβ 42 leading to the modulation of the peptide amyloid-fibril pathway. Biophys Chem 2023; 301:107091. [PMID: 37549471 DOI: 10.1016/j.bpc.2023.107091] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/09/2023]
Abstract
Alzheimer's disease is a progressive degenerative condition that mainly affects cognition and memory. Recently, distinct clinical and neuropathological phenotypes have been identified in AD. Studies revealed that structural variation in Aβ fibrillar aggregates correlates with distinct disease phenotypes. Moreover, environmental surroundings, including other biomolecules such as proteins and lipids, have been shown to interact and modulate Aβ aggregation. Model membranes containing ganglioside (GM1) clusters are specifically known to promote Aβ fibrillogenesis. This study unravels the modulatory effect of non-micellar GM1, a glycosphingolipid frequently released from the damaged neuronal membranes, on Aβ42 amyloid fibril formation. Using far-UV circular dichroism experiments, we observed a change in the peptide secondary structure from random-coil to β-turn structures with subsequent generation of predominantly β-sheet-rich species upon interaction with GM1. Thioflavin-T (ThT) fluorescence assays further indicated that GM1 likely interacts with an amyloidogenic Aβ42 intermediate species leading to a possible formation of GM1-modified Aβ42 fibril. Statistically, no significant difference in toxicity to RA-differentiated SH-SY5Y cells was observed between Aβ42 fibrils and GM1-tweaked Aβ42 aggregates. Moreover, GM1-modified Aβ42 aggregates exhibited prion-like properties in catalyzing the amyloid fibril formation of both major isomers of Aβ, Aβ40, and Aβ42.
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Affiliation(s)
- Manjeet Kumar
- Biophysics, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Magdalena I Ivanova
- Biophysics, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109-1055, USA; Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI 48109-1055, USA.
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3
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Li X, Yang Z, Chen Y, Zhang S, Wei G, Zhang L. Dissecting the Molecular Mechanisms of the Co-Aggregation of Aβ40 and Aβ42 Peptides: A REMD Simulation Study. J Phys Chem B 2023; 127:4050-4060. [PMID: 37126408 DOI: 10.1021/acs.jpcb.3c01078] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The aggregation of amyloid-β protein (Aβ) into oligomers and amyloid fibrils is closely related to Alzheimer's disease (AD). Aβ40 and Aβ42, as two most prominent isoforms of Aβ peptides, can cross-interact with each other and form co-aggregates, which affect the progression of the disease. However, the molecular determinants underlying Aβ40 and Aβ42 cross-interaction and the structural details of their co-oligomers remain elusive. Herein, we performed all-atom explicit-solvent replica exchange molecular dynamics simulations on Aβ40-Aβ42 heterogeneous and Aβ40/Aβ42 homogeneous dimer systems to dissect the co-aggregation mechanisms of the two isoforms. Our results show that the interpeptide main-chain interaction of Aβ40-Aβ42 is stronger than that of Aβ40-Aβ40 and Aβ42-Aβ42. The positions of hotspot residues in heterodimers and homodimers display high similarity, implying similar molecular recognition sites for both cross-interaction and self-interaction. Contact maps of Aβ40-Aβ42 heterodimers reveal that residue pairs crucial for cross-interaction are mostly located in the C-terminal hydrophobic regions of Aβ40 and Aβ42 peptides. Conformational analysis shows that Aβ40 and Aβ42 monomers can co-assemble into β-sheet-rich heterodimers with shorter β-sheets than those in homodimers, which is decremental to monomer addition. Similar molecular recognition sites and β-sheet distribution of Aβ40 and Aβ42 peptides are observed in heterodimers and homodimers, which may provide the molecular basis for the two isoforms' co-aggregation and cross-seeding. Our work dissects the co-aggregation mechanisms of Aβ40 and Aβ42 peptides at the atomic level, which will help for in-depth understanding of the cross-talk between the two Aβ isoforms and the pathogenesis of AD.
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Affiliation(s)
- Xuhua Li
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), and Department of Physics, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Zhiwei Yang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yujie Chen
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), and Department of Physics, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Shengli Zhang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China
| | - Guanghong Wei
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), and Department of Physics, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Lei Zhang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China
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4
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Chen EW, Guo Z. Preparation and Fractionation of Heterogeneous Aβ42 Oligomers with Different Aggregation Properties. Methods Mol Biol 2023; 2551:29-39. [PMID: 36310194 DOI: 10.1007/978-1-0716-2597-2_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Deposition of amyloid-β (Aβ) aggregates in the form of amyloid plaques is a central feature of Alzheimer's disease. The end products of Aβ aggregation are amyloid fibrils. Soluble Aβ aggregates called oligomers are also formed either on or off the pathway of fibril formation. The amyloid fibrils from different clinical subtypes of Alzheimer's disease have been found to adopt different structures, a phenomenon called fibril polymorphism. Meanwhile, different types of Aβ oligomers have also been found. Recently, it has been shown that different types of Aβ42 oligomers may form fibrils of different structures, linking oligomer heterogeneity to fibril polymorphism. In this chapter, we describe methods to prepare heterogeneous Aβ42 oligomers and to quantify the concentration of these oligomers at a low micromolar range using a fluorescamine method. Fractionation of these oligomers by size using ultrafiltration filters allows for the formation of Aβ42 fibrils with different structural properties.
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Affiliation(s)
- Erica W Chen
- Department of Neurology, Brain Research Institute, Molecular Biology Institute, University of California, Los Angeles, CA, USA
| | - Zhefeng Guo
- Department of Neurology, Brain Research Institute, Molecular Biology Institute, University of California, Los Angeles, CA, USA.
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5
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Grain-sized moxibustion inhibits the progression of Alzheimer disease in 5XFAD transgenic mice. JOURNAL OF ACUPUNCTURE AND TUINA SCIENCE 2022. [DOI: 10.1007/s11726-022-1342-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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6
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Burdukiewicz M, Rafacz D, Barbach A, Hubicka K, Bąkała L, Lassota A, Stecko J, Szymańska N, Wojciechowski J, Kozakiewicz D, Szulc N, Chilimoniuk J, Jęśkowiak I, Gąsior-Głogowska M, Kotulska M. AmyloGraph: a comprehensive database of amyloid-amyloid interactions. Nucleic Acids Res 2022; 51:D352-D357. [PMID: 36243982 PMCID: PMC9825533 DOI: 10.1093/nar/gkac882] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/22/2022] [Accepted: 09/30/2022] [Indexed: 01/29/2023] Open
Abstract
Information about the impact of interactions between amyloid proteins on their fibrillization propensity is scattered among many experimental articles and presented in unstructured form. We manually curated information located in almost 200 publications (selected out of 562 initially considered), obtaining details of 883 experimentally studied interactions between 46 amyloid proteins or peptides. We also proposed a novel standardized terminology for the description of amyloid-amyloid interactions, which is included in our database, covering all currently known types of such a cross-talk, including inhibition of fibrillization, cross-seeding and other phenomena. The new approach allows for more specific studies on amyloids and their interactions, by providing very well-defined data. AmyloGraph, an online database presenting information on amyloid-amyloid interactions, is available at (http://AmyloGraph.com/). Its functionalities are also accessible as the R package (https://github.com/KotulskaLab/AmyloGraph). AmyloGraph is the only publicly available repository for experimentally determined amyloid-amyloid interactions.
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Affiliation(s)
| | - Dominik Rafacz
- Faculty of Mathematics and Information Science, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland
| | - Agnieszka Barbach
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Katarzyna Hubicka
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Laura Bąkała
- Faculty of Mathematics and Information Science, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland
| | - Anna Lassota
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Jakub Stecko
- Faculty of Medicine, Wrocław Medical University, Ludwika Pasteura 1, 50-367 Wrocław, Poland
| | - Natalia Szymańska
- Faculty of Medicine, Wrocław Medical University, Ludwika Pasteura 1, 50-367 Wrocław, Poland
| | - Jakub W Wojciechowski
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Dominika Kozakiewicz
- Laboratory of Microbiome Immunobiology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wrocław, Poland
| | - Natalia Szulc
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Jarosław Chilimoniuk
- Department of Genomics, Faculty of Biotechnology, University of Wrocław, Fryderyka Joliot-Curie 14a, 50-383 Wrocław, Poland
| | - Izabela Jęśkowiak
- Department of Pharmacology, Wroclaw Medical University, Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland
| | - Marlena Gąsior-Głogowska
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Małgorzata Kotulska
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
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Liang R, Tian Y, Viles JH. Cross-seeding of WT amyloid-β with Arctic but not Italian familial mutants accelerates fibril formation in Alzheimer's disease. J Biol Chem 2022; 298:102071. [PMID: 35643314 PMCID: PMC9243174 DOI: 10.1016/j.jbc.2022.102071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 01/21/2023] Open
Abstract
Alzheimer’s disease (AD) involves the neurotoxic self-assembly of a 40 and 42 residue peptide, Amyloid-β (Aβ). Inherited early-onset AD can be caused by single point mutations within the Aβ sequence, including Arctic (E22G) and Italian (E22K) familial mutants. These mutations are heterozygous, resulting in an equal proportion of the WT and mutant Aβ isoform expression. It is therefore important to understand how these mixtures of Aβ isoforms interact with each other and influence the kinetics and morphology of their assembly into oligomers and fibrils. Using small amounts of nucleating fibril seeds, here, we systematically monitored the kinetics of fibril formation, comparing self-seeding with cross-seeding behavior of a range of isoform mixtures of Aβ42 and Aβ40. We confirm that Aβ40(WT) does not readily cross-seed Aβ42(WT) fibril formation. In contrast, fibril formation of Aβ40(Arctic) is hugely accelerated by Aβ42(WT) fibrils, causing an eight-fold reduction in the lag-time to fibrillization. We propose that cross-seeding between the more abundant Aβ40(Arctic) and Aβ42(WT) may be important for driving early-onset AD and will propagate fibril morphology as indicated by fibril twist periodicity. This kinetic behavior is not emulated by the Italian mutant, where minimal cross-seeding is observed. In addition, we studied the cross-seeding behavior of a C-terminal-amidated Aβ42 analog to probe the coulombic charge interplay between Glu22/Asp23/Lys28 and the C-terminal carboxylate. Overall, these studies highlight the role of cross-seeding between WT and mutant Aβ40/42 isoforms, which can impact the rate and structure of fibril assembly.
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Affiliation(s)
- Ruina Liang
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, United Kingdom
| | - Yao Tian
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, United Kingdom
| | - John H Viles
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, United Kingdom.
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8
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New Evidence on a Distinction between Aβ40 and Aβ42 Amyloids: Thioflavin T Binding Modes, Clustering Tendency, Degradation Resistance, and Cross-Seeding. Int J Mol Sci 2022; 23:ijms23105513. [PMID: 35628325 PMCID: PMC9141448 DOI: 10.3390/ijms23105513] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/10/2022] [Accepted: 05/13/2022] [Indexed: 12/27/2022] Open
Abstract
The relative abundance of two main Abeta-peptide types with different lengths, Aβ40 and Aβ42, determines the severity of the Alzheimer’s disease progression. However, the factors responsible for different behavior patterns of these peptides in the amyloidogenesis process remain unknown. In this comprehensive study, new evidence on Aβ40 and Aβ42 amyloid polymorphism was obtained using a wide range of experimental approaches, including custom-designed approaches. We have for the first time determined the number of modes of thioflavin T (ThT) binding to Aβ40 and Aβ42 fibrils and their binding parameters using a specially developed approach based on the use of equilibrium microdialysis, which makes it possible to distinguish between the concentration of the injected dye and the concentration of dye bound to fibrils. The binding sites of one of these modes located at the junction of adjacent fibrillar filaments were predicted by molecular modeling techniques. We assumed that the sites of the additional mode of ThT-Aβ42 amyloid binding observed experimentally (which are not found in the case of Aβ40 fibrils) are localized in amyloid clots, and the number of these sites could be used for estimation of the level of fiber clustering. We have shown the high tendency of Aβ42 fibers to form large clots compared to Aβ40 fibrils. It is probable that this largely determines the high resistance of Aβ42 amyloids to destabilizing effects (denaturants, ionic detergents, ultrasonication) and their explicit cytotoxic effect, which we have shown. Remarkably, cross-seeding of Aβ40 fibrillogenesis using the preformed Aβ42 fibrils changes the morphology and increases the stability and cytotoxicity of Aβ40 fibrils. The differences in the tendency to cluster and resistance to external factors of Aβ40 and Aβ42 fibrils revealed here may be related to the distinct role they play in the deposition of amyloids and, therefore, differences in pathogenicity in Alzheimer’s disease.
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9
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Amyloid Cross-Seeding: Mechanism, Implication, and Inhibition. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27061776. [PMID: 35335141 PMCID: PMC8955620 DOI: 10.3390/molecules27061776] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 01/21/2023]
Abstract
Most neurodegenerative diseases such as Alzheimer’s disease, type 2 diabetes, Parkinson’s disease, etc. are caused by inclusions and plaques containing misfolded protein aggregates. These protein aggregates are essentially formed by the interactions of either the same (homologous) or different (heterologous) sequences. Several experimental pieces of evidence have revealed the presence of cross-seeding in amyloid proteins, which results in a multicomponent assembly; however, the molecular and structural details remain less explored. Here, we discuss the amyloid proteins and the cross-seeding phenomena in detail. Data suggest that targeting the common epitope of the interacting amyloid proteins may be a better therapeutic option than targeting only one species. We also examine the dual inhibitors that target the amyloid proteins participating in the cross-seeding events. The future scopes and major challenges in understanding the mechanism and developing therapeutics are also considered. Detailed knowledge of the amyloid cross-seeding will stimulate further research in the practical aspects and better designing anti-amyloid therapeutics.
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10
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Chang HW, Ma HI, Wu YS, Lee MC, Chung-Yueh Yuan E, Huang SJ, Cheng YS, Wu MH, Tu LH, Chan JCC. Site specific NMR characterization of abeta-40 oligomers cross seeded by abeta-42 oligomers. Chem Sci 2022; 13:8526-8535. [PMID: 35974768 PMCID: PMC9337746 DOI: 10.1039/d2sc01555b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 06/12/2022] [Indexed: 12/18/2022] Open
Abstract
Extracellular accumulation of β amyloid peptides of 40 (Aβ40) and 42 residues (Aβ42) has been considered as one of the hallmarks in the pathology of Alzheimer's disease. In this work, we are able to prepare oligomeric aggregates of Aβ with uniform size and monomorphic structure. Our experimental design is to incubate Aβ peptides in reverse micelles (RMs) so that the peptides could aggregate only through a single nucleation process and the size of the oligomers is confined by the physical dimension of the reverse micelles. The hence obtained Aβ oligomers (AβOs) are 23 nm in diameter and they belong to the category of high molecular-weight (MW) oligomers. The solid-state NMR data revealed that Aβ40Os adopt the structural motif of β-loop-β but the chemical shifts manifested that they may be structurally different from low-MW AβOs and mature fibrils. From the thioflavin-T results, we found that high-MW Aβ42Os can accelerate the fibrillization of Aβ40 monomers. Our protocol allows performing cross-seeding experiments among oligomeric species. By comparing the chemical shifts of Aβ40Os cross seeded by Aβ42Os and those of Aβ40Os prepared in the absence of Aβ42Os, we observed that the chemical states of E11, K16, and E22 were altered, whereas the backbone conformation of the β-sheet region near the C-terminus was structurally invariant. The use of reverse micelles allows hitherto the most detailed characterization of the structural variability of Aβ40Os. Extracellular accumulation of β amyloid peptides of 40 (Aβ40) and 42 residues (Aβ42) has been considered as one of the hallmarks in the pathology of Alzheimer's disease.![]()
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Affiliation(s)
- Han-Wen Chang
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Ho-I. Ma
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Yi-Shan Wu
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Ming-Che Lee
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Eric Chung-Yueh Yuan
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Shing-Jong Huang
- Instrumentation Center, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Yu-Sheng Cheng
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Meng-Hsin Wu
- Department of Chemistry, National Taiwan Normal University, No. 88, Section 4, Ting-Chow Road, Taipei, 11677, Taiwan
| | - Ling-Hsien Tu
- Department of Chemistry, National Taiwan Normal University, No. 88, Section 4, Ting-Chow Road, Taipei, 11677, Taiwan
| | - Jerry Chun Chung Chan
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
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11
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Ben-Zichri S, Malishev R, Oren O, Bloch DN, Taube R, Papo N, Jelinek R. Bcl-2-Homology-Only Proapoptotic Peptides Modulate β-Amyloid Aggregation and Toxicity. ACS Chem Neurosci 2021; 12:4554-4563. [PMID: 34806861 DOI: 10.1021/acschemneuro.1c00611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Aggregation of the β-Amyloid (Aβ) peptide in brain tissues is the hallmark of Alzheimer's disease (AD). While Aβ is presumed to be insidiously involved in the disease's pathophysiology, concrete mechanisms accounting for the role of Aβ in AD are yet to be deciphered. While Aβ has been primarily identified in the extracellular space, the peptide also accumulates in cellular compartments such as mitochondria and lysosomes and impairs cellular functions. Here, we show that prominent proapoptotic peptides associated with the mitochondrial outer membrane, the Bcl-2-homology-only peptides BID, PUMA, and NOXA, exert significant and divergent effects upon aggregation, cytotoxicity, and membrane interactions of Aβ42, the main Aβ homolog. Interestingly, we show that BID and PUMA accelerated aggregation of Aβ42, reduced Aβ42-induced toxicity and mitochondrial disfunction, and inhibited Aβ42-membrane interactions. In contrast, NOXA exhibited opposite effects, reducing Aβ42 fibril formation, affecting more pronounced apoptotic effects and mitochondrial disfunction, and enhancing membrane interactions of Aβ42. The effects of BID, PUMA, and NOXA upon the Aβ42 structure and toxicity may be linked to its biological properties and affect pathophysiological features of AD.
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Affiliation(s)
- Shani Ben-Zichri
- Department of Chemistry and Ilse Katz Institute for Nanotechnology, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Ravit Malishev
- Department of Chemistry and Ilse Katz Institute for Nanotechnology, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Ofek Oren
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Daniel N. Bloch
- Department of Chemistry and Ilse Katz Institute for Nanotechnology, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Ran Taube
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Niv Papo
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering and the National Institute of Biotechnology, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Raz Jelinek
- Department of Chemistry and Ilse Katz Institute for Nanotechnology, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
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12
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Oren O, Taube R, Papo N. Amyloid β structural polymorphism, associated toxicity and therapeutic strategies. Cell Mol Life Sci 2021; 78:7185-7198. [PMID: 34643743 PMCID: PMC11072899 DOI: 10.1007/s00018-021-03954-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 08/30/2021] [Accepted: 09/27/2021] [Indexed: 12/14/2022]
Abstract
A review of the multidisciplinary scientific literature reveals a large variety of amyloid-β (Aβ) oligomeric species, differing in molecular weight, conformation and morphology. These species, which may assemble via either on- or off-aggregation pathways, exhibit differences in stability, function and neurotoxicity, according to different experimental settings. The conformations of the different Aβ species are stabilized by intra- and inter-molecular hydrogen bonds and by electrostatic and hydrophobic interactions, all depending on the chemical and physical environment (e.g., solvent, ions, pH) and interactions with other molecules, such as lipids and proteins. This complexity and the lack of a complete understanding of the relationship between the different Aβ species and their toxicity is currently dictating the nature of the inhibitor (or inducer)-based approaches that are under development for interfering with (or inducing) the formation of specific species and Aβ oligomerization, and for interfering with the associated downstream neurotoxic effects. Here, we review the principles that underlie the involvement of different Aβ oligomeric species in neurodegeneration, both in vitro and in preclinical studies. In addition, we provide an overview of the existing inhibitors (or inducers) of Aβ oligomerization that serve as potential therapeutics for neurodegenerative diseases. The review, which covers the exciting studies that have been published in the past few years, comprises three main parts: 1) on- and off-fibrillar assembly mechanisms and Aβ structural polymorphism; 2) interactions of Aβ with other molecules and cell components that dictate the Aβ aggregation pathway; and 3) targeting the on-fibrillar Aβ assembly pathway as a therapeutic approach.
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Affiliation(s)
- Ofek Oren
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, P.O. Box 653, 84105, Beer-Sheva, Israel
- Department of Biotechnology Engineering, Avram and Stella Goldstein-Goren, National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, 84105, Beer-Sheva, Israel
| | - Ran Taube
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, P.O. Box 653, 84105, Beer-Sheva, Israel
| | - Niv Papo
- Department of Biotechnology Engineering, Avram and Stella Goldstein-Goren, National Institute of Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, 84105, Beer-Sheva, Israel.
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13
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Lau HHC, Ingelsson M, Watts JC. The existence of Aβ strains and their potential for driving phenotypic heterogeneity in Alzheimer's disease. Acta Neuropathol 2021; 142:17-39. [PMID: 32743745 DOI: 10.1007/s00401-020-02201-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/17/2022]
Abstract
Reminiscent of the human prion diseases, there is considerable clinical and pathological variability in Alzheimer's disease, the most common human neurodegenerative condition. As in prion disorders, protein misfolding and aggregation is a hallmark feature of Alzheimer's disease, where the initiating event is thought to be the self-assembly of Aβ peptide into aggregates that deposit in the central nervous system. Emerging evidence suggests that Aβ, similar to the prion protein, can polymerize into a conformationally diverse spectrum of aggregate strains both in vitro and within the brain. Moreover, certain types of Aβ aggregates exhibit key hallmarks of prion strains including divergent biochemical attributes and the ability to induce distinct pathological phenotypes when intracerebrally injected into mouse models. In this review, we discuss the evidence demonstrating that Aβ can assemble into distinct strains of aggregates and how such strains may be primary drivers of the phenotypic heterogeneity in Alzheimer's disease.
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14
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McGrowder DA, Miller F, Vaz K, Nwokocha C, Wilson-Clarke C, Anderson-Cross M, Brown J, Anderson-Jackson L, Williams L, Latore L, Thompson R, Alexander-Lindo R. Cerebrospinal Fluid Biomarkers of Alzheimer's Disease: Current Evidence and Future Perspectives. Brain Sci 2021; 11:215. [PMID: 33578866 PMCID: PMC7916561 DOI: 10.3390/brainsci11020215] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease is a progressive, clinically heterogeneous, and particularly complex neurodegenerative disease characterized by a decline in cognition. Over the last two decades, there has been significant growth in the investigation of cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease. This review presents current evidence from many clinical neurochemical studies, with findings that attest to the efficacy of existing core CSF biomarkers such as total tau, phosphorylated tau, and amyloid-β (Aβ42), which diagnose Alzheimer's disease in the early and dementia stages of the disorder. The heterogeneity of the pathophysiology of the late-onset disease warrants the growth of the Alzheimer's disease CSF biomarker toolbox; more biomarkers showing other aspects of the disease mechanism are needed. This review focuses on new biomarkers that track Alzheimer's disease pathology, such as those that assess neuronal injury (VILIP-1 and neurofilament light), neuroinflammation (sTREM2, YKL-40, osteopontin, GFAP, progranulin, and MCP-1), synaptic dysfunction (SNAP-25 and GAP-43), vascular dysregulation (hFABP), as well as CSF α-synuclein levels and TDP-43 pathology. Some of these biomarkers are promising candidates as they are specific and predict future rates of cognitive decline. Findings from the combinations of subclasses of new Alzheimer's disease biomarkers that improve their diagnostic efficacy in detecting associated pathological changes are also presented.
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Affiliation(s)
- Donovan A. McGrowder
- Department of Pathology, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica; (K.V.); (J.B.); (L.A.-J.); (L.L.); (R.T.)
| | - Fabian Miller
- Department of Physical Education, Faculty of Education, The Mico University College, 1A Marescaux Road, Kingston 5, Jamaica;
- Department of Biotechnology, Faculty of Science and Technology, The University of the West Indies, Kingston 7, Jamaica;
| | - Kurt Vaz
- Department of Pathology, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica; (K.V.); (J.B.); (L.A.-J.); (L.L.); (R.T.)
| | - Chukwuemeka Nwokocha
- Department of Basic Medical Sciences, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica; (C.N.); (C.W.-C.); (R.A.-L.)
| | - Cameil Wilson-Clarke
- Department of Basic Medical Sciences, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica; (C.N.); (C.W.-C.); (R.A.-L.)
| | - Melisa Anderson-Cross
- School of Allied Health and Wellness, College of Health Sciences, University of Technology, Kingston 7, Jamaica;
| | - Jabari Brown
- Department of Pathology, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica; (K.V.); (J.B.); (L.A.-J.); (L.L.); (R.T.)
| | - Lennox Anderson-Jackson
- Department of Pathology, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica; (K.V.); (J.B.); (L.A.-J.); (L.L.); (R.T.)
| | - Lowen Williams
- Department of Biotechnology, Faculty of Science and Technology, The University of the West Indies, Kingston 7, Jamaica;
| | - Lyndon Latore
- Department of Pathology, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica; (K.V.); (J.B.); (L.A.-J.); (L.L.); (R.T.)
| | - Rory Thompson
- Department of Pathology, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica; (K.V.); (J.B.); (L.A.-J.); (L.L.); (R.T.)
| | - Ruby Alexander-Lindo
- Department of Basic Medical Sciences, Faculty of Medical Sciences, The University of the West Indies, Kingston 7, Jamaica; (C.N.); (C.W.-C.); (R.A.-L.)
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15
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Xu XJ, Yang MS, Zhang B, Niu F, Dong JQ, Liu BY. Glucose metabolism: A link between traumatic brain injury and Alzheimer's disease. Chin J Traumatol 2021; 24:5-10. [PMID: 33358332 PMCID: PMC7878452 DOI: 10.1016/j.cjtee.2020.10.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 10/08/2020] [Accepted: 10/15/2020] [Indexed: 02/04/2023] Open
Abstract
Traumatic brain injury (TBI), a growing public health problem, is a leading cause of death and disability worldwide, although its prevention measures and clinical cares are substantially improved. Increasing evidence shows that TBI may increase the risk of mood disorders and neurodegenerative diseases, including Alzheimer's disease (AD). However, the complex relationship between TBI and AD remains elusive. Metabolic dysfunction has been the common pathology in both TBI and AD. On the one hand, TBI perturbs the glucose metabolism of the brain, and causes energy crisis and subsequent hyperglycolysis. On the other hand, glucose deprivation promotes amyloidogenesis via β-site APP cleaving enzyme-1 dependent mechanism, and triggers tau pathology and synaptic function. Recent findings suggest that TBI might facilitate Alzheimer's pathogenesis by altering metabolism, which provides clues to metabolic link between TBI and AD. In this review, we will explore how TBI-induced metabolic changes contribute to the development of AD.
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Affiliation(s)
- Xiao-Jian Xu
- Beijing Key Laboratory of Central Nervous System Injury, Beijing Neurosurgical Institute, Capital Medical University, Beijing, 100070, China
| | - Meng-Shi Yang
- Beijing Key Laboratory of Central Nervous System Injury and Department of Neurosurgery, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
| | - Bin Zhang
- Beijing Key Laboratory of Central Nervous System Injury and Department of Neurosurgery, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
| | - Fei Niu
- Beijing Key Laboratory of Central Nervous System Injury, Beijing Neurosurgical Institute, Capital Medical University, Beijing, 100070, China
| | - Jin-Qian Dong
- Beijing Key Laboratory of Central Nervous System Injury and Department of Neurosurgery, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
| | - Bai-Yun Liu
- Beijing Key Laboratory of Central Nervous System Injury, Beijing Neurosurgical Institute, Capital Medical University, Beijing, 100070, China,Beijing Key Laboratory of Central Nervous System Injury and Department of Neurosurgery, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China,Nerve Injury and Repair Center of Beijing Institute for Brain Disorders, Beijing, 100070, China,China National Clinical Research Center for Neurological Diseases, Beijing, 100070, China,Corresponding author. Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing, 100070, China.
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16
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Pradhan T, Annamalai K, Sarkar R, Huhn S, Hegenbart U, Schönland S, Fändrich M, Reif B. Seeded fibrils of the germline variant of human λ-III immunoglobulin light chain FOR005 have a similar core as patient fibrils with reduced stability. J Biol Chem 2020; 295:18474-18484. [PMID: 33093170 PMCID: PMC7939468 DOI: 10.1074/jbc.ra120.016006] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/21/2020] [Indexed: 11/26/2022] Open
Abstract
Systemic antibody light chains (AL) amyloidosis is characterized by deposition of amyloid fibrils derived from a particular antibody light chain. Cardiac involvement is a major risk factor for mortality. Using MAS solid-state NMR, we studied the fibril structure of a recombinant light chain fragment corresponding to the fibril protein from patient FOR005, together with fibrils formed by protein sequence variants that are derived from the closest germline (GL) sequence. Both analyzed fibril structures were seeded with ex-vivo amyloid fibrils purified from the explanted heart of this patient. We find that residues 11-42 and 69-102 adopt β-sheet conformation in patient protein fibrils. We identify arginine-49 as a key residue that forms a salt bridge to aspartate-25 in the patient protein fibril structure. In the germline sequence, this residue is replaced by a glycine. Fibrils from the GL protein and from the patient protein harboring the single point mutation R49G can be both heterologously seeded using patient ex-vivo fibrils. Seeded R49G fibrils show an increased heterogeneity in the C-terminal residues 80-102, which is reflected by the disappearance of all resonances of these residues. By contrast, residues 11-42 and 69-77, which are visible in the MAS solid-state NMR spectra, show 13Cα chemical shifts that are highly like patient fibrils. The mutation R49G thus induces a conformational heterogeneity at the C terminus in the fibril state, whereas the overall fibril topology is retained. These findings imply that patient mutations in FOR005 can stabilize the fibril structure.
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Affiliation(s)
- Tejaswini Pradhan
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit und UmweltInstitute of Structural Biology (STB), Neuherberg, Germany; Munich Center for Integrated Protein Science (CIPS-M) at the Dept. of Chemistry, Technische Universität München (TUM), Garching, Germany
| | | | - Riddhiman Sarkar
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit und UmweltInstitute of Structural Biology (STB), Neuherberg, Germany; Munich Center for Integrated Protein Science (CIPS-M) at the Dept. of Chemistry, Technische Universität München (TUM), Garching, Germany
| | - Stefanie Huhn
- Medical Department V, Multiple Myeloma Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Ute Hegenbart
- Medical Department V, Amyloidosis Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Stefan Schönland
- Medical Department V, Amyloidosis Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Marcus Fändrich
- Institute of Protein Biochemistry, Ulm University, Ulm, Germany
| | - Bernd Reif
- Helmholtz-Zentrum München (HMGU), Deutsches Forschungszentrum für Gesundheit und UmweltInstitute of Structural Biology (STB), Neuherberg, Germany; Munich Center for Integrated Protein Science (CIPS-M) at the Dept. of Chemistry, Technische Universität München (TUM), Garching, Germany.
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17
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From Brain to Heart: Possible Role of Amyloid-β in Ischemic Heart Disease and Ischemia-Reperfusion Injury. Int J Mol Sci 2020; 21:ijms21249655. [PMID: 33348925 PMCID: PMC7766370 DOI: 10.3390/ijms21249655] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/13/2020] [Accepted: 12/14/2020] [Indexed: 02/06/2023] Open
Abstract
Ischemic heart disease (IHD) is among the leading causes of death in developed countries. Its pathological origin is traced back to coronary atherosclerosis, a lipid-driven immuno-inflammatory disease of the arteries that leads to multifocal plaque development. The primary clinical manifestation of IHD is acute myocardial infarction (AMI),) whose prognosis is ameliorated with optimal timing of revascularization. Paradoxically, myocardium re-perfusion can be detrimental because of ischemia-reperfusion injury (IRI), an oxidative-driven process that damages other organs. Amyloid-β (Aβ) plays a physiological role in the central nervous system (CNS). Alterations in its synthesis, concentration and clearance have been connected to several pathologies, such as Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA). Aβ has been suggested to play a role in the pathogenesis of IHD and cerebral IRI. The purpose of this review is to summarize what is known about the pathological role of Aβ in the CNS; starting from this evidence, we will illustrate the role played by Aβ in the development of coronary atherosclerosis and its possible implications in the pathophysiology of IHD and myocardial IRI. Better elucidation of Aβ's contribution to the molecular pathways underlying IHD and IRI could be of great help in developing new therapeutic strategies.
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18
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Gu L, Guo Z. Alzheimer's Aβ42 and Aβ40 form mixed oligomers with direct molecular interactions. Biochem Biophys Res Commun 2020; 534:292-296. [PMID: 33272573 DOI: 10.1016/j.bbrc.2020.11.092] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 11/25/2020] [Indexed: 12/27/2022]
Abstract
Formation of Aβ oligomers and fibrils plays a central role in the pathogenesis of Alzheimer's disease. There are two major forms of Aβ in the brain: Aβ42 and Aβ40. Aβ42 is the major component of the amyloid plaques, but the overall abundance of Aβ40 is several times that of Aβ42. In vitro experiments show that Aβ42 and Aβ40 affect each other's aggregation. In mouse models of Alzheimer's disease, overexpression of Aβ40 has been shown to reduce the plaque pathology, suggesting that Aβ42 and Aβ40 also interact in vivo. Here we address the question of whether Aβ42 and Aβ40 interact with each other in the formation of oligomers using electron paramagnetic resonance (EPR) spectroscopy. When the Aβ42 oligomers were formed using only spin-labeled Aβ42, the dipolar interaction between spin labels that are within 20 Å range broadened the EPR spectrum and reduced its amplitude. Oligomers formed with a mixture of spin-labeled Aβ42 and wild-type Aβ42 gave an EPR spectrum with higher amplitude due to weakened spin-spin interactions, suggesting molecular mixing of labeled and wild-type Aβ42. When spin-labeled Aβ42 and wild-type Aβ40 were mixed to form oligomers, the resulting EPR spectrum also showed reduced amplitude, suggesting that wild-type Aβ40 can also form oligomers with spin-labeled Aβ42. Therefore, our results suggest that Aβ42 and Aβ40 form mixed oligomers with direct molecular interactions. Our results point to the importance of investigating Aβ42-Aβ40 interactions in the brain for a complete understanding of Alzheimer's pathogenesis and therapeutic interventions.
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Affiliation(s)
- Lei Gu
- Department of Neurology, Brain Research Institute, Molecular Biology Institute, University of California, Los Angeles, CA, 90095, USA
| | - Zhefeng Guo
- Department of Neurology, Brain Research Institute, Molecular Biology Institute, University of California, Los Angeles, CA, 90095, USA.
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19
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Rudajev V, Novotny J. The Role of Lipid Environment in Ganglioside GM1-Induced Amyloid β Aggregation. MEMBRANES 2020; 10:membranes10090226. [PMID: 32916822 PMCID: PMC7558528 DOI: 10.3390/membranes10090226] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/04/2020] [Accepted: 09/07/2020] [Indexed: 01/14/2023]
Abstract
Ganglioside GM1 is the most common brain ganglioside enriched in plasma membrane regions known as lipid rafts or membrane microdomains. GM1 participates in many modulatory and communication functions associated with the development, differentiation, and protection of neuronal tissue. It has, however, been demonstrated that GM1 plays a negative role in the pathophysiology of Alzheimer's disease (AD). The two features of AD are the formation of intracellular neurofibrillary bodies and the accumulation of extracellular amyloid β (Aβ). Aβ is a peptide characterized by intrinsic conformational flexibility. Depending on its partners, Aβ can adopt different spatial arrangements. GM1 has been shown to induce specific changes in the spatial organization of Aβ, which lead to enhanced peptide accumulation and deleterious effect especially on neuronal membranes containing clusters of this ganglioside. Changes in GM1 levels and distribution during the development of AD may contribute to the aggravation of the disease.
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20
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Park G, Xue C, Wang H, Guo Z. Distinguishing the Effect on the Rate and Yield of Aβ42 Aggregation by Green Tea Polyphenol EGCG. ACS OMEGA 2020; 5:21497-21505. [PMID: 32905372 PMCID: PMC7469419 DOI: 10.1021/acsomega.0c02063] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/10/2020] [Indexed: 05/15/2023]
Abstract
Deposition of Aβ42 aggregates in the form of amyloid plaques is a pathological hallmark of Alzheimer's disease. A desired avenue of intervention is the inhibition of Aβ42 aggregation. Epigallocatechin gallate (EGCG), the main polyphenol in green tea, has been generally considered an inhibitor of Aβ aggregation. However, previous experiments focused on the reduction of the amount of Aβ42 aggregates, while the effect of EGCG on the rate of Aβ42 aggregation was not critically analyzed. Here we performed an experimental evaluation of Aβ42 aggregation kinetics in the absence and presence of EGCG at a wide range of concentrations. We found that EGCG reduced thioflavin T fluorescence in an EGCG concentration-dependent manner, suggesting that EGCG reduced the amount of Aβ42 fibrils. The effect of EGCG on the rate of Aβ42 aggregation appears to be bimodal. We found that higher EGCG-to-Aβ42 ratios promoted the rate of Aβ42 aggregation, while lower EGCG-to-Aβ42 ratios inhibited the aggregation rate. To confirm that the reduction of thioflavin T fluorescence is due to the lowered aggregate quantity, but not due to perturbation of thioflavin T binding to Aβ42 fibrils, we probed the effect of EGCG on Aβ42 aggregation using site-directed spin labeling. Electron paramagnetic resonance of spin-labeled Aβ42 aggregates suggests that high EGCG-to-Aβ42 ratios led to a greatly reduced amount of Aβ42 fibrils, and these aggregates adopt similar structures as the fibrils in the no-EGCG sample. Potential implications of this work in designing prevention or therapeutic strategies using EGCG are discussed.
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21
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Ke PC, Zhou R, Serpell LC, Riek R, Knowles TPJ, Lashuel HA, Gazit E, Hamley IW, Davis TP, Fändrich M, Otzen DE, Chapman MR, Dobson CM, Eisenberg DS, Mezzenga R. Half a century of amyloids: past, present and future. Chem Soc Rev 2020; 49:5473-5509. [PMID: 32632432 PMCID: PMC7445747 DOI: 10.1039/c9cs00199a] [Citation(s) in RCA: 304] [Impact Index Per Article: 76.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Amyloid diseases are global epidemics with profound health, social and economic implications and yet remain without a cure. This dire situation calls for research into the origin and pathological manifestations of amyloidosis to stimulate continued development of new therapeutics. In basic science and engineering, the cross-β architecture has been a constant thread underlying the structural characteristics of pathological and functional amyloids, and realizing that amyloid structures can be both pathological and functional in nature has fuelled innovations in artificial amyloids, whose use today ranges from water purification to 3D printing. At the conclusion of a half century since Eanes and Glenner's seminal study of amyloids in humans, this review commemorates the occasion by documenting the major milestones in amyloid research to date, from the perspectives of structural biology, biophysics, medicine, microbiology, engineering and nanotechnology. We also discuss new challenges and opportunities to drive this interdisciplinary field moving forward.
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Affiliation(s)
- Pu Chun Ke
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- Zhongshan Hospital, Fudan University, 111 Yixueyuan Rd, Xuhui District, Shanghai, China
| | - Ruhong Zhou
- Institute of Quantitative Biology, Zhejiang University, Hangzhou 310058, China; Department of Chemistry, Columbia University, New York, New York, 10027, USA
| | - Louise C. Serpell
- School of Life Sciences, University of Sussex, Falmer, East Sussex BN1 9QG, UK
| | - Roland Riek
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Wolfgang-Pauli-Str. 10, 8093 Zurich, Switzerland
| | - Tuomas P. J. Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, CB3 0HE, Cambridge, UK
| | - Hilal A. Lashuel
- Laboratory of Molecular Neurobiology and Neuroproteomics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences; Department of Materials Science and Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, 69978 Tel Aviv, Israel
| | - Ian W. Hamley
- School of Chemistry, Food Biosciences and Pharmacy, University of Reading, Whiteknights, Reading RG6 6AD, UK
| | - Thomas P. Davis
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane Qld 4072, Australia
| | - Marcus Fändrich
- Institute of Protein Biochemistry, Ulm University, 89081, Ulm, Germany
| | - Daniel Erik Otzen
- Department of Molecular Biology, Center for Insoluble Protein Structures (inSPIN), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark
| | - Matthew R. Chapman
- Department of Molecular, Cellular and Developmental Biology, Centre for Microbial Research, University of Michigan, Ann Arbor, MI 48109-1048, USA
| | - Christopher M. Dobson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - David S. Eisenberg
- Departments of Chemistry and Biochemistry and Biological Chemistry, UCLA-DOE Institute and Howard Hughes Medical Institute, UCLA, Los Angeles, CA, USA
| | - Raffaele Mezzenga
- Department of Health Science & Technology, ETH Zurich, Schmelzbergstrasse 9, LFO, E23, 8092 Zurich, Switzerland
- Department of Materials, ETH Zurich, Wolfgang Pauli Strasse 10, 8093 Zurich, Switzerland
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22
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Biophysical studies of protein misfolding and aggregation in in vivo models of Alzheimer's and Parkinson's diseases. Q Rev Biophys 2020; 49:e22. [PMID: 32493529 DOI: 10.1017/s0033583520000025] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Neurodegenerative disorders, including Alzheimer's (AD) and Parkinson's diseases (PD), are characterised by the formation of aberrant assemblies of misfolded proteins. The discovery of disease-modifying drugs for these disorders is challenging, in part because we still have a limited understanding of their molecular origins. In this review, we discuss how biophysical approaches can help explain the formation of the aberrant conformational states of proteins whose neurotoxic effects underlie these diseases. We discuss in particular models based on the transgenic expression of amyloid-β (Aβ) and tau in AD, and α-synuclein in PD. Because biophysical methods have enabled an accurate quantification and a detailed understanding of the molecular mechanisms underlying protein misfolding and aggregation in vitro, we expect that the further development of these methods to probe directly the corresponding mechanisms in vivo will open effective routes for diagnostic and therapeutic interventions.
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23
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Galzitskaya OV. Oligomers Are Promising Targets for Drug Development in the Treatment of Proteinopathies. Front Mol Neurosci 2020; 12:319. [PMID: 32076398 PMCID: PMC7006448 DOI: 10.3389/fnmol.2019.00319] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 12/16/2019] [Indexed: 12/31/2022] Open
Abstract
Currently, there is no effective treatment of proteinopathies, as well as their diagnosis in the early stages of the disease until the first clinical symptoms appear. The proposed model of fibrillation of the Aβ peptide and its fragments not only describes molecular rearrangements, but also offers models of processes that occur during the formation of amyloid aggregates. Since this model is also characteristic of other proteins and peptides, a new potential target for drug development in the treatment of Alzheimer’s disease (AD) and other proteinopathies is proposed on the basis of this model. In our opinion, it is oligomers that are promising targets for innovative developments in the treatment of these diseases.
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Affiliation(s)
- Oxana V Galzitskaya
- Laboratory of Bioinformatics and Proteomics, Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russia.,Laboratory of the Structure and Function of Muscle Proteins, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
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24
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Cerofolini L, Ravera E, Bologna S, Wiglenda T, Böddrich A, Purfürst B, Benilova I, Korsak M, Gallo G, Rizzo D, Gonnelli L, Fragai M, De Strooper B, Wanker EE, Luchinat C. Mixing Aβ(1–40) and Aβ(1–42) peptides generates unique amyloid fibrils. Chem Commun (Camb) 2020; 56:8830-8833. [DOI: 10.1039/d0cc02463e] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Solid-state NMR experiments reveal that the two isoforms of the beta-amyloid peptide (Aβ(1–40) and Aβ(1–42)) are able to form unique interlaced mixed fibrils.
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25
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Chaudhuri P, Prajapati KP, Anand BG, Dubey K, Kar K. Amyloid cross-seeding raises new dimensions to understanding of amyloidogenesis mechanism. Ageing Res Rev 2019; 56:100937. [PMID: 31430565 DOI: 10.1016/j.arr.2019.100937] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 06/21/2019] [Accepted: 07/23/2019] [Indexed: 12/12/2022]
Abstract
Hallmarks of most of the amyloid pathologies are surprisingly found to be heterocomponent entities such as inclusions and plaques which contain diverse essential proteins and metabolites. Experimental studies have already revealed the occurrence of coaggregation and cross-seeding during amyloid formation of several proteins and peptides, yielding multicomponent assemblies of amyloid nature. Further, research reports on the co-occurrence of more than one type of amyloid-linked pathologies in the same individual suggest the possible cross-talk among the disease related amyloidogenic protein species during their amyloid growth. In this review paper, we have tried to gain more insight into the process of coaggregation and cross-seeding during amyloid aggregation of proteins, particularly focusing on their relevance to the pathogenesis of the protein misfolding diseases. Revelation of amyloid cross-seeding and coaggregation seems to open new dimensions in our mechanistic understanding of amyloidogenesis and such knowledge may possibly inspire better designing of anti-amyloid therapeutics.
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26
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Xue C, Tran J, Wang H, Park G, Hsu F, Guo Z. Aβ42 fibril formation from predominantly oligomeric samples suggests a link between oligomer heterogeneity and fibril polymorphism. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190179. [PMID: 31417723 PMCID: PMC6689619 DOI: 10.1098/rsos.190179] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 06/10/2019] [Indexed: 05/27/2023]
Abstract
Amyloid-β (Aβ) oligomers play a central role in the pathogenesis of Alzheimer's disease. Oligomers of different sizes, morphology and structures have been reported in both in vivo and in vitro studies, but there is a general lack of understanding about where to place these oligomers in the overall process of Aβ aggregation and fibrillization. Here, we show that Aβ42 spontaneously forms oligomers with a wide range of sizes in the same sample. These Aβ42 samples contain predominantly oligomers, and they quickly form fibrils upon incubation at 37°C. When fractionated using ultrafiltration filters, the samples enriched with smaller oligomers form fibrils at a faster rate than the samples enriched with larger oligomers, with both a shorter lag time and faster fibril growth rate. This observation is independent of Aβ42 batches and hexafluoroisopropanol treatment. Furthermore, the fibrils formed by the samples enriched with larger oligomers are more readily solubilized by epigallocatechin gallate, a main catechin component of green tea. These results suggest that the fibrils formed by larger oligomers may adopt a different structure from fibrils formed by smaller oligomers, pointing to a link between oligomer heterogeneity and fibril polymorphism.
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Affiliation(s)
| | | | | | | | | | - Zhefeng Guo
- Department of Neurology, Brain Research Institute, Molecular Biology Institute, University of California, 710 Westwood Plaza, Los Angeles, CA 90095, USA
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Saikia J, Pandey G, Sasidharan S, Antony F, Nemade HB, Kumar S, Chaudhary N, Ramakrishnan V. Electric Field Disruption of Amyloid Aggregation: Potential Noninvasive Therapy for Alzheimer's Disease. ACS Chem Neurosci 2019; 10:2250-2262. [PMID: 30707008 DOI: 10.1021/acschemneuro.8b00490] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The aggregation of β-amyloid peptides is a key event in the formative stages of Alzheimer's disease. Promoting folding and inhibiting aggregation was reported as an effective strategy in reducing Aβ-elicited toxicity. This study experimentally investigates the influence of the external electric field (EF) and magnetic field (MF) of varying strengths on the in vitro fibrillogenesis of hydrophobic core sequence, Aβ16-22, and its parent peptide, Aβ1-42. Biophysical methods such as ThT fluorescence, static light scattering, circular dichroism, and infrared spectroscopy suggest that EF has a stabilizing effect on the secondary structure, initiating a conformational switch of Aβ16-22 and Aβ1-42 from β to non-β conformation. This observation was further corroborated by dynamic light scattering and transmission electron microscopic studies. To mimic in vivo conditions, we repeated ThT fluorescence assay with Aβ1-42 in human cerebrospinal fluid to verify EF-mediated modulation. The self-seeding of Aβ1-42 and cross-seeding with Aβ1-40 to verify that the autocatalytic amplification of self-assembly as a result of secondary nucleation also yields comparable results in EF-exposed and unexposed samples. Aβ-elicited toxicity of EF-treated samples in two neuroblastoma cell lines (SH-SY5Y and IMR-32) and human embryonic kidney cell line (HEK293) were found to be 15-38% less toxic than the EF untreated ones under identical conditions. Experiments with fluorescent labeled Aβ1-42 to correlate reduced cytotoxicity and cell internalization suggest a comparatively smaller uptake of the EF-treated peptides. Our results provide a scientific roadmap for future noninvasive, therapeutic solutions for the treatment of Alzheimer's disease.
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Selivanova OM, Rogachevsky VV, Syrin AK, Galzitskaya OV. [Molecular mechanism of amyloid formation by Ab peptide: review of own works]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2019; 64:94-109. [PMID: 29460839 DOI: 10.18097/pbmc20186401094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
TA characteristic feature of amyloid structures is polymorphism. The study of amyloid structures and their formation process was carried out for synthetic and recombinant Ab(1-40) and Ab(1-42) peptide preparations. In the study of these peptides, we recognized fibrils of different morphologies. We observed fibrillar formations in the form of single fibrils, ribbons, bundles, bunches, and clusters. Polymorphism of fibrils was observed not only when the environmental conditions changed, but under the same conditions and this was a common characteristics of all amyloid formations. Fibrils of Ab(1-40) peptides tended to form aggregates of fibrils in the form of ribbons, while Ab(1-42) peptide under the same conditions polymerized in the form of rough fibrils of different diameters and tends to branch. We assume that the formation of fibrils of Ab(1-40) and Ab(1-42) peptides occurs according to a simplified scheme: a destabilized monomer ® a ring oligomer ® a mature fibril consisting of ring oligomers. Proceeding from the proposition that the ring oligomer is the main building block of amyloid fibril (similar to the cell in the body), it is easy to explain fibril polymorphism, as well as fragmentation of mature fibrils under various external influences, branching and irregularity of diameter (surface roughness) of fibrils. One aspect of the study of amyloidogenesis is the determination of the regions of the protein chain forming the core of the amyloid fibril. We theoretically predicted amyloidogenic regions for two isoforms of Ab peptides capable of forming an amyloid structure: 16-21 and 32-36 residues. Using the method of tandem mass spectrometry, these regions were determined experimentally. It was shown that the regions of Ab(1-40) peptide from 16 to 22 and from 28 to 40 residues were resistant to the action of proteases, i.e. its formed the core of the amyloid fibril. For Ab(1-42) peptide the whole sequence is not available for the action of proteases, which indicates a different way of associating ring oligomers in the formation of fibrils. Based on electron microscopy and mass spectrometry data we proposed a molecular model of the fibril formed by Ab(1-40) and Ab(1-42) peptides.
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Affiliation(s)
- O M Selivanova
- Institute of Protein Research, Pushchino, Moscow Region, Russia
| | - V V Rogachevsky
- Institute of Cell Biophysics, Pushchino, Moscow Region, Russia
| | - A K Syrin
- Institute of Protein Research, Pushchino, Moscow Region, Russia; State Scientific Center of Applied Microbiology and biotechnology, Village Obolensk, Moscow Region, Serpukhov District, Russia
| | - O V Galzitskaya
- Institute of Protein Research, Pushchino, Moscow Region, Russia
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29
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Galzitskaya OV, Surin AK, Glyakina AV, Rogachevsky VV, Selivanova OM. Should the Treatment of Amyloidosis Be Personified? Molecular Mechanism of Amyloid Formation by Aβ Peptide and Its Fragments. J Alzheimers Dis Rep 2018; 2:181-199. [PMID: 30480261 PMCID: PMC6218156 DOI: 10.3233/adr-180063] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Aβ40 and Aβ42 peptides are believed to be associated with Alzheimer's disease. Aggregates (plaques) of Aβ fibrils are found in the brains of humans affected with this disease. The mechanism of formation of Aβ fibrils has not been studied completely, which hinders the development of a correct strategy for therapeutic prevention of this neurodegenerative disorder. It has been found that the most toxic samples upon generation of fibrils are different oligomeric formations. Based on different research methods used for studying amyloidogenesis of Aβ40 and Aβ42 peptides and its amyloidogenic fragments, we have proposed a new mechanism of formation of amyloid fibrils. In accord with this mechanism, the main building unit for fibril generation is a ring-like oligomer. Association of ring-like oligomers results in the formation of fibrils of different morphologies. Our model implies that to prevent development of Alzheimer's disease a therapeutic intervention is required at the earliest stages of amyloidogenesis-at the stage of formation of ring-like oligomers. Therefore, the possibility of a personified approach for prevention not only of Alzheimer's disease development but also of other neurodegenerative diseases associated with the formation of fibrils is argued.
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Affiliation(s)
- Oxana V Galzitskaya
- Institute of Protein Research, Russian Academy of Science, Pushchino, Moscow Region, Russia
| | - Alexey K Surin
- Institute of Protein Research, Russian Academy of Science, Pushchino, Moscow Region, Russia.,State Scientific Center of Applied Microbiology and Biotechnology, Moscow Region, Serpukhov District, Obolensk, Russia.,Gamaleya Research Center of Epidemiology and Microbiology, Moscow, Russia
| | - Anna V Glyakina
- Institute of Protein Research, Russian Academy of Science, Pushchino, Moscow Region, Russia.,Institute of Mathematical Problems of Biology RAS, Keldysh Institute of Applied Mathematics of Russian Academy of Sciences, Pushchino, Russia
| | - Vadim V Rogachevsky
- Institute of Cell Biophysics, Russian Academy of Science, Pushchino, Moscow Region, Russia
| | - Olga M Selivanova
- Institute of Protein Research, Russian Academy of Science, Pushchino, Moscow Region, Russia
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30
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An Aβ42 variant that inhibits intra- and extracellular amyloid aggregation and enhances cell viability. Biochem J 2018; 475:3087-3103. [DOI: 10.1042/bcj20180247] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 09/02/2018] [Accepted: 09/07/2018] [Indexed: 01/06/2023]
Abstract
Aggregation and accumulation of the 42-residue amyloid β peptide (Aβ42) in the extracellular matrix and within neuronal cells is considered a major cause of neuronal cell cytotoxicity and death in Alzheimer's disease (AD) patients. Therefore, molecules that bind to Aβ42 and prevent its aggregation are therapeutically promising as AD treatment. Here, we show that a non-self-aggregating Aβ42 variant carrying two surface mutations, F19S and L34P (Aβ42DM), inhibits wild-type Aβ42 aggregation and significantly reduces Aβ42-mediated cell cytotoxicity. In addition, Aβ42DM inhibits the uptake and internalization of extracellularly added pre-formed Aβ42 aggregates into cells. This was the case in both neuronal and non-neuronal cells co-expressing Aβ42 and Aβ42DM or following pre-treatment of cells with extracellular soluble forms of the two peptides, even at high Aβ42 to Aβ42DM molar ratios. In cells, Aβ42DM associates with Aβ42, while in vitro, the two soluble recombinant peptides exhibit nano-molar binding affinity. Importantly, Aβ42DM potently suppresses Aβ42 amyloid aggregation in vitro, as demonstrated by thioflavin T fluorescence and transmission electron microscopy for detecting amyloid fibrils. Overall, we present a new approach for inhibiting Aβ42 fibril formation both within and outside cells. Accordingly, Aβ42DM should be evaluated in vivo for potential use as a therapeutic lead for treating AD.
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Wang D, Dong X, Wang C. Honokiol Ameliorates Amyloidosis and Neuroinflammation and Improves Cognitive Impairment in Alzheimer’s Disease Transgenic Mice. J Pharmacol Exp Ther 2018; 366:470-478. [DOI: 10.1124/jpet.118.248674] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 07/05/2018] [Indexed: 12/31/2022] Open
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32
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Wang H, Lee YK, Xue C, Guo Z. Site-specific structural order in Alzheimer's Aβ42 fibrils. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180166. [PMID: 30109072 PMCID: PMC6083707 DOI: 10.1098/rsos.180166] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/31/2018] [Indexed: 05/27/2023]
Abstract
Deposition of amyloid fibrils is a pathological hallmark of Alzheimer's disease. Aβ42 is the major protein whose aggregation leads to the formation of these fibrils. Understanding the detailed structure of Aβ42 fibrils is of particular importance for delineating the mechanism of Aβ42 aggregation and developing specific amyloid-targeting drugs. Here, we use site-directed spin labelling and electron paramagnetic resonance spectroscopy to study the site-specific structural order at each and every residue position in Aβ42 fibrils. Strong interactions between spin labels indicate highly ordered protein backbone at the labelling site, while weak interactions suggest disordered local structure. Our results show that Aβ42 consists of five β-strands (residues 2-7, 10-13, 17-20, 31-36, 39-41), three turns (residues 7-8, 14-16, 37-38) and one ordered loop (residues 21-30). Spin labels introduced at β-strand sites show strong spin-spin interactions, while spin labels at turn or loop sites show weak interactions. However, residues 24, 25 and 28 also show strong interactions between spin labels, suggesting that the loop 21-30 is partly ordered. In the context of recent structural work using solid-state NMR and cryoEM, the site-specific structural order revealed in this study provides a different perspective on backbone and side chain dynamics of Aβ42 fibrils.
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Affiliation(s)
| | | | | | - Zhefeng Guo
- Department of Neurology, Brain Research Institute, Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
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Galzitskaya OV, Galushko EI, Selivanova OM. Studies of the Process of Amyloid Formation by Aβ Peptide. BIOCHEMISTRY (MOSCOW) 2018; 83:S62-S80. [PMID: 29544432 DOI: 10.1134/s0006297918140079] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Studies of the process of amyloid formation by Aβ peptide have been topical due to the critical role of this peptide in the pathogenesis of Alzheimer's disease. Many articles devoted to this process are available in the literature; however, none of them gives a detailed description of the mechanism of the process of generation of amyloids. Moreover, there are no reliable data on the influence of modified forms of Aβ peptide on its amyloid formation. To appreciate the role of Aβ aggregation in the pathogenesis of Alzheimer's disease and to develop a strategy for its treatment, it is necessary to have a well-defined description of the molecular mechanism underlying the formation of amyloids as well as the contribution of each intermediate to this process. We are convinced that a combined analysis of theoretical and experimental methods is a way for understanding molecular mechanisms of numerous diseases. Based on our experimental data and molecular modeling, we have constructed a general model of the process of amyloid formation by Aβ peptide. Using the data described in our previous publications, we propose a model of amyloid formation by this peptide that differs from the generally accepted model. Our model can be applied to other proteins and peptides as well. According to this model, the main building unit for the formation of amyloid fibrils is a ring-like oligomer. Upon interaction with each other, ring-like oligomers form long fibrils of different morphology. This mechanism of generation of amyloid fibrils may be common for other proteins and peptides.
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Affiliation(s)
- O V Galzitskaya
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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34
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Yau WM, Tycko R. Depletion of amyloid-β peptides from solution by sequestration within fibril-seeded hydrogels. Protein Sci 2018; 27:1218-1230. [PMID: 29417648 DOI: 10.1002/pro.3387] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 02/02/2018] [Accepted: 02/05/2018] [Indexed: 11/10/2022]
Abstract
Aggregation of amyloid-β (Aβ) peptides in brain tissue leads to neurodegeneration in Alzheimer's disease (AD). Regardless of the kinetics or detailed mechanisms of Aβ aggregation, aggregation can only occur if Aβ concentrations exceed their local equilibrium solubility values. We propose that excess Aβ peptides can be removed from supersaturated solutions, including solutions in biological fluids, by the addition of hydrogels that are seeded with Aβ fibril fragments. Fibril growth within the hydrogels then sequesters excess peptides until equilibrium concentrations are reached. Experiments with 40- and 42-residue Aβ peptides (Aβ40 and Aβ42) in phosphate buffer at 24°C and in filtered fetal bovine serum at 37°C, using crosslinked polyacrylamide hydrogels, demonstrate the validity of this concept. Aβ sequestration in fibril-seeded hydrogels (or other porous media) may prove to be a useful technique in experiments with animal models of AD and may represent a possible approach to preventing or slowing the progression of AD in humans.
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Affiliation(s)
- Wai-Ming Yau
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, 20892-0520
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, 20892-0520
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35
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Villar-Piqué A, Schmitz M, Candelise N, Ventura S, Llorens F, Zerr I. Molecular and Clinical Aspects of Protein Aggregation Assays in Neurodegenerative Diseases. Mol Neurobiol 2018; 55:7588-7605. [DOI: 10.1007/s12035-018-0926-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 01/24/2018] [Indexed: 12/20/2022]
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36
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Baldassarre M, Baronio CM, Morozova-Roche LA, Barth A. Amyloid β-peptides 1-40 and 1-42 form oligomers with mixed β-sheets. Chem Sci 2017; 8:8247-8254. [PMID: 29568473 PMCID: PMC5857929 DOI: 10.1039/c7sc01743j] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 10/12/2017] [Indexed: 12/16/2022] Open
Abstract
Two main amyloid-β peptides of different length (Aβ40 and Aβ42) are involved in Alzheimer's disease. Their relative abundance is decisive for the severity of the disease and mixed oligomers may contribute to the toxic species. However, little is know about the extent of mixing. To study whether Aβ40 and Aβ42 co-aggregate, we used Fourier transform infrared spectroscopy in combination with 13C-labeling and spectrum calculation and focused on the amide I vibration, which is sensitive to backbone structure. Mixtures of monomeric labeled Aβ40 and unlabeled Aβ42 (and vice versa) were co-incubated for ∼20 min and their infrared spectrum recorded. The position of the main 13C-amide I' band shifted to higher wavenumbers with increasing admixture of 12C-peptide due to the presence of 12C-amides in the vicinity of 13C-amides. The results indicate that Aβ40 and Aβ42 form mixed oligomers with a largely random distribution of Aβ40 and Aβ42 strands in their β-sheets. The structures of the mixed oligomers are intermediate between those of the pure oligomers. There is no indication that one of the peptides forces the backbone structure of its oligomers on the other peptide when they are mixed as monomers. We also demonstrate that isotope-edited infrared spectroscopy can distinguish aggregation modulators that integrate into the backbone structure of their interaction partner from those that do not. As an example for the latter case, the pro-inflammatory calcium binding protein S100A9 is shown not to incorporate into the β-sheets of Aβ42.
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Affiliation(s)
- Maurizio Baldassarre
- Department of Biochemistry and Biophysics , Stockholm University , Arrhenius Laboratories , 10691 Stockholm , Sweden .
| | - Cesare M Baronio
- Department of Biochemistry and Biophysics , Stockholm University , Arrhenius Laboratories , 10691 Stockholm , Sweden .
| | | | - Andreas Barth
- Department of Biochemistry and Biophysics , Stockholm University , Arrhenius Laboratories , 10691 Stockholm , Sweden .
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37
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Xue C, Lee YK, Tran J, Chang D, Guo Z. A mix-and-click method to measure amyloid-β concentration with sub-micromolar sensitivity. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170325. [PMID: 28878984 PMCID: PMC5579099 DOI: 10.1098/rsos.170325] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 07/13/2017] [Indexed: 05/27/2023]
Abstract
Aggregation of amyloid-β (Aβ) protein plays a central role in Alzheimer's disease. Because protein aggregation is a concentration-dependent process, rigorous investigations require accurate concentration measurements. Owing to the high aggregation propensity of Aβ protein, working solutions of Aβ are typically in the low micromolar range. Therefore, an ideal Aβ quantification method requires high sensitivity without sacrificing speed and accuracy. Absorbance at 280 nm is frequently used to measure Aβ concentration, but the sensitivity is low with only one tyrosine and no tryptophan residues in the Aβ sequence. Here we present a fluorescence method for Aβ quantification using fluorescamine, which gives high fluorescence upon reaction with primary amines. We show that, using hen egg white lysozyme as a standard, fluorescence correlates linearly with primary amine concentration across a wide range of fluorescamine concentrations, from 62.5 to 1000 µM. The maximal sensitivity of detection is achieved at a fluorescamine concentration of 250 µM or higher. The fluorescamine method is compatible with the presence of dimethyl sulfoxide, which is commonly used in the preparation of Aβ oligomers, and limits the use of absorbance at 280 nm due to its high background reading. Using aggregation kinetics, we show that the fluorescamine method gives accurate concentration measurements at low micromolar range and leads to highly consistent aggregation data. We recommend the fluorescamine assay to be used for routine and on-the-fly concentration determination in Aβ oligomerization and fibrillization experiments.
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Affiliation(s)
| | | | | | | | - Zhefeng Guo
- Author for correspondence: Zhefeng Guo e-mail:
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