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Kurakin S, Badreeva D, Dushanov E, Shutikov A, Efimov S, Timerova A, Mukhametzyanov T, Murugova T, Ivankov O, Mamatkulov K, Arzumanyan G, Klochkov V, Kučerka N. Arrangement of lipid vesicles and bicelle-like structures formed in the presence of Aβ(25-35) peptide. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184237. [PMID: 37820938 DOI: 10.1016/j.bbamem.2023.184237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/31/2023] [Accepted: 10/03/2023] [Indexed: 10/13/2023]
Abstract
Our complementary experimental data and molecular dynamics (MD) simulations results reveal the structure of previously observed lipid bicelle-like structures (BLSs) formed in the presence of amyloid-beta peptide Aβ(25-35) below the main phase transition temperature (Tm) of saturated phosphatidylcholine lipids and small unilamellar vesicles (SUVs) above this temperature. First, we show by using solid-state 31P nuclear magnetic resonance (NMR) spectroscopy that our BLSs being in the lipid gel phase demonstrate magnetic alignment along the magnetic field of NMR spectrometer and undergo a transition to SUVs in the lipid fluid phase when heated through the Tm. Secondly, thanks to the BLS alignment we present their lipid structure. Lipids are found located not only in the flat bilayered part but also around its perimeter, which is corroborated by the results of coarse-grained (CG) MD simulations. Finally, peptides appear to mix randomly with lipids in SUVs while assuming predominantly unordered secondary structures revealed by circular dichroism (CD), Raman spectroscopy, and all-atom MD simulations. Importantly, the former is changing little when the system undergoes morphological transitions between BLSs and SUVs. Our structural results then offer a platform for studying and understanding mechanisms of morphological transformations caused by the disruptive effect of amyloid-beta peptides on the lipid bilayer.
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Affiliation(s)
- Sergei Kurakin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia; Institute of Physics, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia.
| | - Dina Badreeva
- Meshcheryakov Laboratory of Information Technologies, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Ermuhammad Dushanov
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Artyom Shutikov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Sergey Efimov
- Institute of Physics, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia
| | - Ayzira Timerova
- Institute of Physics, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia
| | - Timur Mukhametzyanov
- Butlerov Chemistry Institute, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia
| | - Tatiana Murugova
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Oleksandr Ivankov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Kahramon Mamatkulov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Grigory Arzumanyan
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Vladimir Klochkov
- Institute of Physics, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia
| | - Norbert Kučerka
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia; Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Odbojárov 10, Bratislava 832 32, Slovakia.
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Kell DB, Pretorius E. Are fibrinaloid microclots a cause of autoimmunity in Long Covid and other post-infection diseases? Biochem J 2023; 480:1217-1240. [PMID: 37584410 DOI: 10.1042/bcj20230241] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/03/2023] [Accepted: 08/07/2023] [Indexed: 08/17/2023]
Abstract
It is now well established that the blood-clotting protein fibrinogen can polymerise into an anomalous form of fibrin that is amyloid in character; the resultant clots and microclots entrap many other molecules, stain with fluorogenic amyloid stains, are rather resistant to fibrinolysis, can block up microcapillaries, are implicated in a variety of diseases including Long COVID, and have been referred to as fibrinaloids. A necessary corollary of this anomalous polymerisation is the generation of novel epitopes in proteins that would normally be seen as 'self', and otherwise immunologically silent. The precise conformation of the resulting fibrinaloid clots (that, as with prions and classical amyloid proteins, can adopt multiple, stable conformations) must depend on the existing small molecules and metal ions that the fibrinogen may (and is some cases is known to) have bound before polymerisation. Any such novel epitopes, however, are likely to lead to the generation of autoantibodies. A convergent phenomenology, including distinct conformations and seeding of the anomalous form for initiation and propagation, is emerging to link knowledge in prions, prionoids, amyloids and now fibrinaloids. We here summarise the evidence for the above reasoning, which has substantial implications for our understanding of the genesis of autoimmunity (and the possible prevention thereof) based on the primary process of fibrinaloid formation.
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Affiliation(s)
- Douglas B Kell
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, U.K
- The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Kemitorvet 200, 2800 Kgs Lyngby, Denmark
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa
| | - Etheresia Pretorius
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, U.K
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa
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Kell DB, Laubscher GJ, Pretorius E. A central role for amyloid fibrin microclots in long COVID/PASC: origins and therapeutic implications. Biochem J 2022; 479:537-559. [PMID: 35195253 PMCID: PMC8883497 DOI: 10.1042/bcj20220016] [Citation(s) in RCA: 107] [Impact Index Per Article: 53.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 12/15/2022]
Abstract
Post-acute sequelae of COVID (PASC), usually referred to as 'Long COVID' (a phenotype of COVID-19), is a relatively frequent consequence of SARS-CoV-2 infection, in which symptoms such as breathlessness, fatigue, 'brain fog', tissue damage, inflammation, and coagulopathies (dysfunctions of the blood coagulation system) persist long after the initial infection. It bears similarities to other post-viral syndromes, and to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Many regulatory health bodies still do not recognize this syndrome as a separate disease entity, and refer to it under the broad terminology of 'COVID', although its demographics are quite different from those of acute COVID-19. A few years ago, we discovered that fibrinogen in blood can clot into an anomalous 'amyloid' form of fibrin that (like other β-rich amyloids and prions) is relatively resistant to proteolysis (fibrinolysis). The result, as is strongly manifested in platelet-poor plasma (PPP) of individuals with Long COVID, is extensive fibrin amyloid microclots that can persist, can entrap other proteins, and that may lead to the production of various autoantibodies. These microclots are more-or-less easily measured in PPP with the stain thioflavin T and a simple fluorescence microscope. Although the symptoms of Long COVID are multifarious, we here argue that the ability of these fibrin amyloid microclots (fibrinaloids) to block up capillaries, and thus to limit the passage of red blood cells and hence O2 exchange, can actually underpin the majority of these symptoms. Consistent with this, in a preliminary report, it has been shown that suitable and closely monitored 'triple' anticoagulant therapy that leads to the removal of the microclots also removes the other symptoms. Fibrin amyloid microclots represent a novel and potentially important target for both the understanding and treatment of Long COVID and related disorders.
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Affiliation(s)
- Douglas B. Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, U.K
- The Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Kemitorvet 200, 2800 Kgs Lyngby, Denmark
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, South Africa
| | | | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, 7602, South Africa
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4
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Jiang J, Liu Y, Wu Q. Revisit the Cellular Transmission and Emerging Techniques in Understanding the Mechanisms of Proteinopathies. Front Neurosci 2021; 15:781722. [PMID: 34867177 PMCID: PMC8636772 DOI: 10.3389/fnins.2021.781722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/29/2021] [Indexed: 11/13/2022] Open
Abstract
Alzheimer’s and Parkinson’s diseases (AD and PD) are amongst top of the prevalent neurodegenerative disease. One-third of PD patients are diagnosed with dementia, a pre-symptom of AD, but the underlying mechanism is elusive. Amyloid beta (Aβ) and α-synuclein are two of the most investigated proteins, whose pathological aggregation and spreading are crucial to the pathogenesis of AD and PD, respectively. Transcriptomic studies of the mammalian central nervous system shed light on gene expression profiles at molecular levels, regarding the complexity of neuronal morphologies and electrophysiological inputs/outputs. In the last decade, the booming of the single-cell RNA sequencing technique helped to understand gene expression patterns, alternative splicing, novel transcripts, and signal pathways in the nervous system at single-cell levels, providing insight for molecular taxonomy and mechanistic targets of the degenerative nervous system. Here, we re-visited the cell-cell transmission mechanisms of Aβ and α-synuclein in mediating disease propagation, and summarized recent single-cell transcriptome sequencing from different perspectives and discussed its understanding of neurodegenerative diseases.
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Affiliation(s)
- Jinwen Jiang
- Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Yu Liu
- Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Qihui Wu
- Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
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Zhang H, Song Q, Yu G, Cao Z, Qiang X, Liu X, Deng Y. Phthalimide-(N-alkylbenzylamine) cysteamide hybrids as multifunctional agents against Alzheimer's disease: Design, synthesis, and biological evaluation. Chem Biol Drug Des 2021; 98:493-500. [PMID: 34143938 DOI: 10.1111/cbdd.13905] [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: 12/21/2020] [Revised: 04/13/2021] [Accepted: 06/06/2021] [Indexed: 11/30/2022]
Abstract
The complex pathogenesis of Alzheimer's disease (AD) calls for multi-target approach for disease treatment. Herein, based on the MTDLs strategy, a series of phthalimide-(N-alkylbenzylamine) cysteamide hybrids were designed, synthesized, and investigated in vitro for the purpose. Most of the target compounds were found to be potential multi-target agents. In vitro results showed that compound 9e was the representative compound in this series, endowed with high EeAChE and HuAChE inhibitory potency (IC50 = 1.55 µm and 2.23 µm, respectively), good inhibitory activity against self-induced Aβ1-42 aggregation (36.08% at 25 µm), and moderate antioxidant capacity (ORAC-FL value was 0.68 Trolox equivalents). Molecular docking studies rationalized the binding mode of 9e in both PAS and CAS of AChE. Moreover, 9e displayed excellent ability to against H2 O2 -induced PC12 cell injury and penetrate BBB. Overall, these results highlighted that compound 9e was an effective and promising multi-target agent for further anti-AD drug development.
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Affiliation(s)
- Heng Zhang
- Department of Medicinal Chemistry, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Qing Song
- Department of Medicinal Chemistry, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Guangjun Yu
- Department of Medicinal Chemistry, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Zhongcheng Cao
- Department of Medicinal Chemistry, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Xiaoming Qiang
- Department of Medicinal Chemistry, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Xiuxiu Liu
- Department of Medicinal Chemistry, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Yong Deng
- Department of Medicinal Chemistry, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, China
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Kanchi PK, Dasmahapatra AK. Enhancing the binding of the β-sheet breaker peptide LPFFD to the amyloid-β fibrils by aromatic modifications: A molecular dynamics simulation study. Comput Biol Chem 2021; 92:107471. [PMID: 33706107 DOI: 10.1016/j.compbiolchem.2021.107471] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/25/2021] [Accepted: 02/27/2021] [Indexed: 11/25/2022]
Abstract
Alzheimer's is a fatal neurodegenerative disease for which there is no cure at present. The disease is characterized by the presence of plaques in the brains of a patient, which are composed mainly of aggregates of the amyloid-β peptide in the form of β-sheet fibrils. Here, we investigated the possibility of exploiting the superior binding ability of aromatic amino acids to a particular model of the amyloid-β fibrils. which is a difficult target for drug design. The β-sheet breaker peptide LPFFD was modified with aromatic amino acids and its binding to these fibrils was studied. We found that the orientation and the electrostatic complementarity of the modified peptide with respect to the fibrils played a crucial role in determining whether its binding was improved by the aromatic amino acids. The modified LPFFD peptides were able to bind to those fibril residues. which are important in the aggregation of amyloid-β peptides and thus can potentially inhibit the further aggregation of the amyloid-beta peptides by blocking their interactions. We found that the tryptophan modified LPFFD peptides had the best binding affinities. In most cases, the aromatic amino acids in the N-terminus of the modified peptides made more contacts with the fibrils than those in the C-terminus. We also found that increasing the aromatic content did not significantly improve the binding of the LPFFD peptide to the fibrils. Our study can serve as a basis for the design of novel peptide-based drugs for Alzheimer's disease in which aromatic interactions play an important role.
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Affiliation(s)
- Pavan Krishna Kanchi
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Ashok Kumar Dasmahapatra
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India; Center for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
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7
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Wang X, Wang C, Chan HN, Ashok I, Krishnamoorthi SK, Li M, Li HW, Wong MS. Amyloid-β oligomer targeted theranostic probes for in vivo NIR imaging and inhibition of self-aggregation and amyloid-β induced ROS generation. Talanta 2021; 224:121830. [DOI: 10.1016/j.talanta.2020.121830] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/20/2020] [Accepted: 10/28/2020] [Indexed: 12/15/2022]
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8
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Xing X, Liu C, Ali A, Kang B, Li P, Ai H. Novel Disassembly Mechanisms of Sigmoid Aβ 42 Protofibrils by Introduced Neutral and Charged Drug Molecules. ACS Chem Neurosci 2020; 11:45-56. [PMID: 31697060 DOI: 10.1021/acschemneuro.9b00550] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by fibrillar deposits of amyloid-β (Aβ) peptides and neurofibrillary tangles of Tau proteins. Aβ peptides are composed of 37-49 residues, among which the Aβ42 isoform is particularly toxic and aggregation-prone and is enriched in the plaques of AD brains and thus considered central to the development of AD. Therefore, disaggregation and disruption provide potential therapeutic approaches to reduce, inhibit, and even reverse Aβ aggregation. Here we capture the atomic-level details of the interactions between sigmoid Aβ42 fibril 2MXU or 5KK3 and either natural tanshinone compounds TS1 or TS0 or negatively charged ER, proposing two unprecedented disassembly mechanisms. Natural TS1 or TS0 prefers to insert into the cavity together with part at the surface of the 2MXU to open up the mouth and twist the conformation, destroying the ordered growth of subsequent monomers along the fibril axis. For the more compact two-fold 5KK3 , attachment of TS1 or TS0 at the surface including some inserted in cavity results in the separation of the two folds. In the two sigmoid fibril systems, it is no longer applicable for the routine criteria to assess Aβ42 fibril disassembly by introduction of these drugs, such as either reduced H-bond number, decreased β-sheet contents, or both. ER, like-charged to Aβ42 fibril, is especially exceptional, and departs utterly from the neutral ones to disassemble Aβ42 fibril. Besides the inapplicable routine criteria, positive binding energy between ER and Aβ42 fibril also deviates from the hypotheses of "ligands exhibiting greater affinity for the β-amyloid peptide are effective at altering its aggregation and inhibiting cell toxicity" ( Cairo et al. , Biochemistry 2002 , 41 , 8620 - 8629 ) but results in stronger disassembly effect on the two kinds of sigmoid Aβ42 fibrils than neutral TS0 or TS1. The disassembly power of charged ER molecules derives from its stronger deformation ability to the conformation of Aβ42 fibril than the neutral ones, twisting the one-fold 2MXU into tapered-shape and separating two-fold 5KK3 in two parts further, which is in great agreement with experimental observations ( Irwin et al. Biomacromolecules 2013 , 14 ( 1 ), 264 - 274 ). The unusual disassembly mechanisms fill the gaps and offer an alternative direction in engineering new inhibitors to treat AD.
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Affiliation(s)
- Xiaofeng Xing
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China
| | - Chengqiang Liu
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China
| | - Aqsa Ali
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China
| | - Baotao Kang
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China
| | - Ping Li
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China
| | - Hongqi Ai
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China
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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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10
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Xing X, Liu C, Yang H, Nouman MF, Ai H. Folding dynamics of Aβ42 monomer at pH 4.0–7.5 with and without physiological salt conditions – does the β1 or β2 region fold first? NEW J CHEM 2020. [DOI: 10.1039/d0nj01090a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The seeding region of Aβ42 monomer is jointly affected by the solution acidity, ionic distribution of the salt, and charged residues.
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Affiliation(s)
- Xiaofeng Xing
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
- China
| | - Chengqiang Liu
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
- China
| | - Huijuan Yang
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
- China
| | | | - Hongqi Ai
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
- China
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The Amyloid as a Ribbon-Like Micelle in Contrast to Spherical Micelles Represented by Globular Proteins. Molecules 2019; 24:molecules24234395. [PMID: 31816829 PMCID: PMC6930452 DOI: 10.3390/molecules24234395] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 11/27/2019] [Accepted: 11/29/2019] [Indexed: 01/18/2023] Open
Abstract
Selected amyloid structures available in the Protein Data Bank have been subjected to a comparative analysis. Classification is based on the distribution of hydrophobicity in amyloids that differ with respect to sequence, chain length, the distribution of beta folds, protofibril structure, and the arrangement of protofibrils in each superfibril. The study set includes the following amyloids: Aβ (1-42), which is listed as Aβ (15-40) and carries the D23N mutation, and Aβ (11-42) and Aβ (1-40), both of which carry the E22Δ mutation, tau amyloid, and α-synuclein. Based on the fuzzy oil drop model (FOD), we determined that, despite their conformational diversity, all presented amyloids adopt a similar structural pattern that can be described as a ribbon-like micelle. The same model, when applied to globular proteins, results in structures referred to as "globular micelles," emerging as a result of interactions between the proteins' constituent residues and the aqueous solvent. Due to their composition, amyloids are unable to attain entropically favorable globular forms and instead attempt to limit contact between hydrophobic residues and water by producing elongated structures. Such structures typically contain quasi hydrophobic cores that stretch along the fibril's long axis. Similar properties are commonly found in ribbon-like micelles, with alternating bands of high and low hydrophobicity emerging as the fibrils increase in length. Thus, while globular proteins are generally consistent with a 3D Gaussian distribution of hydrophobicity, the distribution instead conforms to a 2D Gaussian distribution in amyloid fibrils.
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12
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Polyproline chains destabilize the Alzheimer's amyloid-β protofibrils: A molecular dynamics simulation study. J Mol Graph Model 2019; 93:107456. [PMID: 31581064 DOI: 10.1016/j.jmgm.2019.107456] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/22/2019] [Accepted: 09/24/2019] [Indexed: 12/11/2022]
Abstract
Alzheimer's is a fatal neurodegenerative disease for which there is no cure at present. The disease is characterized by the presence of plaques, principally comprising the amyloid-β peptide (viz., β-sheet) in the brains of a patient. In our present work, we study the interaction of these β-sheets with a different number of repeating units of proline (β-sheet breaker) by docking and all atom molecular dynamics simulations. Our results indicate that proline can break the amyloid protofibrils apart, cause them to break their β-sheet structure, and in some cases even induce the formation of 310 helices, which may be intermediates in the unfolding of these β-sheets. We have also observed that some of the important hydrogen bonds and salt bridges between chains were disrupted by proline and the tight interatomic packing of atoms in the fibrils was made relatively loose. Proline chains had a tendency to make several contacts with charged residues. Proline chains binded well to the fibrils by strong electrostatic interactions while hydrophobic interactions played a less important role. This leads to the conclusion that proline can break the amyloid fibrils apart and can be considered in the design of novel peptide-based drugs to treat Alzheimer's disease and potentially other diseases caused by the misfolding of proteins into β-sheets.
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Fabian P, Stapor K, Banach M, Ptak-Kaczor M, Konieczny L, Roterman I. Different Synergy in Amyloids and Biologically Active Forms of Proteins. Int J Mol Sci 2019; 20:E4436. [PMID: 31505841 PMCID: PMC6769701 DOI: 10.3390/ijms20184436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 08/31/2019] [Accepted: 09/04/2019] [Indexed: 11/16/2022] Open
Abstract
Protein structure is the result of the high synergy of all amino acids present in the protein. This synergy is the result of an overall strategy for adapting a specific protein structure. It is a compromise between two trends: The optimization of non-binding interactions and the directing of the folding process by an external force field, whose source is the water environment. The geometric parameters of the structural form of the polypeptide chain in the form of a local radius of curvature that is dependent on the orientation of adjacent peptide bond planes (result of the respective Phi and Psi rotation) allow for a comparative analysis of protein structures. Certain levels of their geometry are the criteria for comparison. In particular, they can be used to assess the differences between the structural form of biologically active proteins and their amyloid forms. On the other hand, the application of the fuzzy oil drop model allows the assessment of the role of amino acids in the construction of tertiary structure through their participation in the construction of a hydrophobic core. The combination of these two models-the geometric structure of the backbone and the determining of the participation in the construction of the tertiary structure that is applied for the comparative analysis of biologically active and amyloid forms-is presented.
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Affiliation(s)
- Piotr Fabian
- Institute of Computer Science, Silesian University of Technology, Akademicka 16, 44-100 Gliwice, Poland
| | - Katarzyna Stapor
- Institute of Computer Science, Silesian University of Technology, Akademicka 16, 44-100 Gliwice, Poland
| | - Mateusz Banach
- Department of Bioinformatics and Telemedicine, Jagiellonian University-Medical College, Łazarza 16, 31-530 Kraków, Poland
| | - Magdalena Ptak-Kaczor
- Department of Bioinformatics and Telemedicine, Jagiellonian University-Medical College, Łazarza 16, 31-530 Kraków, Poland
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Łojasiewicza 11, 30-348 Krakow, Poland
| | - Leszek Konieczny
- Chair of Medical Biochemistry, Jagiellonian University-Medical College, 31-034 Krakow, Poland
| | - Irena Roterman
- Department of Bioinformatics and Telemedicine, Jagiellonian University-Medical College, Łazarza 16, 31-530 Kraków, Poland.
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14
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Structure of amyloid β 25-35 in lipid environment and cholesterol-dependent membrane pore formation. Sci Rep 2019; 9:2689. [PMID: 30804528 PMCID: PMC6389947 DOI: 10.1038/s41598-019-38749-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/08/2019] [Indexed: 01/14/2023] Open
Abstract
The amyloid β (Aβ) peptide and its shorter variants, including a highly cytotoxic Aβ25–35 peptide, exert their neurotoxic effect during Alzheimer’s disease by various mechanisms, including cellular membrane permeabilization. The intrinsic polymorphism of Aβ has prevented the identification of the molecular basis of Aβ pore formation by direct structural methods, and computational studies have led to highly divergent pore models. Here, we have employed a set of biophysical techniques to directly monitor Ca2+-transporting Aβ25–35 pores in lipid membranes, to quantitatively characterize pore formation, and to identify the key structural features of the pore. Moreover, the effect of membrane cholesterol on pore formation and the structure of Aβ25–35 has been elucidated. The data suggest that the membrane-embedded peptide forms 6- or 8-stranded β-barrel like structures. The 8-stranded barrels may conduct Ca2+ ions through an inner cavity, whereas the tightly packed 6-stranded barrels need to assemble into supramolecular structures to form a central pore. Cholesterol affects Aβ25–35 pore formation by a dual mechanism, i.e., by direct interaction with the peptide and by affecting membrane structure. Collectively, our data illuminate the molecular basis of Aβ membrane pore formation, which should advance both basic and clinical research on Alzheimer’s disease and membrane-associated pathologies in general.
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15
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Kozin SA, Barykin EP, Mitkevich VA, Makarov AA. Anti-amyloid Therapy of Alzheimer's Disease: Current State and Prospects. BIOCHEMISTRY (MOSCOW) 2018; 83:1057-1067. [PMID: 30472944 DOI: 10.1134/s0006297918090079] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Drug development for the treatment of Alzheimer's disease (AD) has been for a long time focused on agents that were expected to support endogenous β-amyloid (Aβ) in a monomeric state and destroy soluble Aβ oligomers and insoluble Aβ aggregates. However, this strategy has failed over the last 20 years and was eventually abandoned. In this review, we propose a new approach to the anti-amyloid AD therapy based on the latest achievements in understanding molecular causes of cerebral amyloidosis in AD animal models.
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Affiliation(s)
- S A Kozin
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia
| | - E P Barykin
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia
| | - V A Mitkevich
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia.
| | - A A Makarov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia.
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16
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Thai NQ, Bednarikova Z, Gancar M, Linh HQ, Hu CK, Li MS, Gazova Z. Compound CID 9998128 Is a Potential Multitarget Drug for Alzheimer's Disease. ACS Chem Neurosci 2018; 9:2588-2598. [PMID: 29775277 DOI: 10.1021/acschemneuro.8b00091] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We have probed small molecule compound CID 9998128 as a potential multitarget drug for the Alzheimer's disease (AD) using in silico and in vitro experiments. By all-atom simulation and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) method, we have demonstrated that this compound strongly binds to both amyloid β42 (Aβ42) fibrils and β-secretase, and the van der Waals interaction dominates over the electrostatic interaction in binding affinity. A detailed analysis at the atomic level revealed that indazole in CID 99998128 structure made a major contribution to instability of all studied complexes. In vitro experiments have shown that CID 9998128 inhibits the Aβ42 amyloid fibrillization and is capable to clear Aβ42 fibrils. Moreover, the compound dose-dependently decreases β-site amyloid precursor protein cleaving enzyme (BACE-1) activity with EC50 value in micromolar range. Thus, our study has revealed that CID 9998128 is a good candidate for AD treatment through preventing production of Aβ peptides and degrading their aggregates. For drug design, we predict that the chemical structure of potent AD multitarget inhibitors should not contain indazole.
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Affiliation(s)
- Nguyen Quoc Thai
- Institute for Computational Sciences and Technology, SBI building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam
- Dong Thap University, 783 Pham Huu Lau Street, Ward 6, Cao Lanh City, Dong Thap, Vietnam
- Biomedical Engineering Department, University of Technology -VNU HCM, 268 Ly Thuong Kiet Str., Distr. 10, Ho Chi Minh City, Vietnam
| | - Zuzana Bednarikova
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, Kosice 040 01, Slovakia
| | - Miroslav Gancar
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, Kosice 040 01, Slovakia
| | - Huynh Quang Linh
- Biomedical Engineering Department, University of Technology -VNU HCM, 268 Ly Thuong Kiet Str., Distr. 10, Ho Chi Minh City, Vietnam
| | - Chin-Kun Hu
- Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
- Physics Division, National Center for Theretical Sciences, Hsinchu 30013, Taiwan
- Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan
- Department of Systems Science, University of Schanghai for Science and Technology, Shanghai 200093, China
| | - Mai Suan Li
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Zuzana Gazova
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, Kosice 040 01, Slovakia
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17
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Banach M, Konieczny L, Wiśniowski Z, Roterman I. Fragment Aβ(18-41) presented within the CDR3 loop region of a shark immunoglobulin new antigen receptor single-variable domain antibody analyzed based on the fuzzy oil drop model. BIO-ALGORITHMS AND MED-SYSTEMS 2018. [DOI: 10.1515/bams-2018-0028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The structure of amyloid Aβ(1-41) is the object of many papers due to the neurodegenerative processes induced by this amyloid. One of the ways to investigate the possible structural forms other than the amyloid is to incorporate the fragment of this peptide into the chain of immunoglobulin. Fragment Aβ(18-41) presented within the CDR3 loop region of a shark immunoglobulin new antigen receptor single-variable domain antibody is the object of this analysis. The structure of this hybrid is available in the PDB and analyzed based on the fuzzy oil drop model. The aim is to define the status of this fragment, revealing the possible fitting to the ordered form of the hydrophobic core. Simultaneously, the verification of the predisposition to complexation is possible.
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18
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Przygońska K, Poznański J, Mistarz UH, Rand KD, Dadlez M. Side-chain moieties from the N-terminal region of Aβ are Involved in an oligomer-stabilizing network of interactions. PLoS One 2018; 13:e0201761. [PMID: 30080867 PMCID: PMC6078298 DOI: 10.1371/journal.pone.0201761] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 07/20/2018] [Indexed: 12/31/2022] Open
Abstract
Oligomeric forms of the Aβ peptide represent the most probable neurotoxic agent in Alzheimer’s disease. The dynamic and heterogeneous character of these oligomers makes their structural characterization by classic methods difficult. Native mass spectrometry, when supported by additional gas phase techniques, like ion mobility separation and hydrogen-deuterium exchange (IM-HDX-MS), enable analysis of different oligomers coexisting in the sample and may provide species-specific structural information for each oligomeric form populated in the gas phase. Here, we have combined these three techniques to obtain insight into the structural properties of oligomers of Aβ1–40 and two variants with scrambled sequences. Gas-phase HDX-MS revealed a sequence-specific engagement of the side-chains of residues located at the N-terminal part of the peptide in a network of oligomer-stabilizing interactions. Oligomer-specific interactions were no longer observed in the case of the fully scrambled sequence. Also, the ability to form alternative structures, observed for WT Aβ peptide, was lost upon scrambling. Our data underscore a role for the N-terminal residues in shaping the equilibria of oligomeric forms. Although the peptide lacking the N-terminal 1–16 residues (p3 peptide) is thought to be benign, the role of the N-terminus has not been sufficiently characterized yet. We speculate that the interaction networks revealed here may be crucial for enabling structural transitions necessary to obtain mature parallel cross-β structures from smaller antiparallel oligomers. We provide a hypothetical molecular model of the trajectory that allows a gradual conversion from antiparallel to parallel oligomers without decomposition of oligomers. Oligomer-defining interactions involving the Aβ peptide N-terminus may be important in production of the neurotoxic forms and thus should not be neglected.
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Affiliation(s)
- Kaja Przygońska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Jarosław Poznański
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Ulrik H. Mistarz
- Department of Pharmacy, University of Copenhagen, Copenhagen, Denmark
| | - Kasper D. Rand
- Department of Pharmacy, University of Copenhagen, Copenhagen, Denmark
| | - Michał Dadlez
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- Institute of Genetics and Biotechnology, Department of Biology, University of Warsaw, Warsaw, Poland
- * E-mail:
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19
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Kell DB, Pretorius E. No effects without causes: the Iron Dysregulation and Dormant Microbes hypothesis for chronic, inflammatory diseases. Biol Rev Camb Philos Soc 2018; 93:1518-1557. [PMID: 29575574 PMCID: PMC6055827 DOI: 10.1111/brv.12407] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/12/2018] [Accepted: 02/15/2018] [Indexed: 12/11/2022]
Abstract
Since the successful conquest of many acute, communicable (infectious) diseases through the use of vaccines and antibiotics, the currently most prevalent diseases are chronic and progressive in nature, and are all accompanied by inflammation. These diseases include neurodegenerative (e.g. Alzheimer's, Parkinson's), vascular (e.g. atherosclerosis, pre-eclampsia, type 2 diabetes) and autoimmune (e.g. rheumatoid arthritis and multiple sclerosis) diseases that may appear to have little in common. In fact they all share significant features, in particular chronic inflammation and its attendant inflammatory cytokines. Such effects do not happen without underlying and initially 'external' causes, and it is of interest to seek these causes. Taking a systems approach, we argue that these causes include (i) stress-induced iron dysregulation, and (ii) its ability to awaken dormant, non-replicating microbes with which the host has become infected. Other external causes may be dietary. Such microbes are capable of shedding small, but functionally significant amounts of highly inflammagenic molecules such as lipopolysaccharide and lipoteichoic acid. Sequelae include significant coagulopathies, not least the recently discovered amyloidogenic clotting of blood, leading to cell death and the release of further inflammagens. The extensive evidence discussed here implies, as was found with ulcers, that almost all chronic, infectious diseases do in fact harbour a microbial component. What differs is simply the microbes and the anatomical location from and at which they exert damage. This analysis offers novel avenues for diagnosis and treatment.
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Affiliation(s)
- Douglas B. Kell
- School of ChemistryThe University of Manchester, 131 Princess StreetManchesterLancsM1 7DNU.K.
- The Manchester Institute of BiotechnologyThe University of Manchester, 131 Princess StreetManchesterLancsM1 7DNU.K.
- Department of Physiological SciencesStellenbosch University, Stellenbosch Private Bag X1Matieland7602South Africa
| | - Etheresia Pretorius
- Department of Physiological SciencesStellenbosch University, Stellenbosch Private Bag X1Matieland7602South Africa
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20
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Bi XA, Sun Q, Zhao J, Xu Q, Wang L. Non-linear ICA Analysis of Resting-State fMRI in Mild Cognitive Impairment. Front Neurosci 2018; 12:413. [PMID: 29970984 PMCID: PMC6018085 DOI: 10.3389/fnins.2018.00413] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 05/30/2018] [Indexed: 01/02/2023] Open
Abstract
Compared to linear independent component analysis (ICA), non-linear ICA is more suitable for the decomposition of mixed components. Existing studies of functional magnetic resonance imaging (fMRI) data by using linear ICA assume that the brain's mixed signals, which are caused by the activity of brain, are formed through the linear combination of source signals. But the application of the non-linear combination of source signals is more suitable for the mixed signals of brain. For this reason, we investigated statistical differences in resting state networks (RSNs) on 32 healthy controls (HC) and 38 mild cognitive impairment (MCI) patients using post-nonlinear ICA. Post-nonlinear ICA is one of the non-linear ICA methods. Firstly, the fMRI data of all subjects was preprocessed. The second step was to extract independent components (ICs) of fMRI data of all subjects. In the third step, we calculated the correlation coefficient between ICs and RSN templates, and selected ICs of the largest spatial correlation coefficient. The ICs represent the corresponding RSNs. After finding out the eight RSNs of MCI group and HC group, one sample t-tests were performed. Finally, in order to compare the differences of RSNs between MCI and HC groups, the two-sample t-tests were carried out. We found that the functional connectivity (FC) of RSNs in MCI patients was abnormal. Compared with HC, MCI patients showed the increased and decreased FC in default mode network (DMN), central executive network (CEN), dorsal attention network (DAN), somato-motor network (SMN), visual network(VN), MCI patients displayed the specifically decreased FC in auditory network (AN), self-referential network (SRN). The FC of core network (CN) did not reveal significant group difference. The results indicate that the abnormal FC in RSNs is selective in MCI patients.
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Affiliation(s)
- Xia-An Bi
- College of Information Science and Engineering, Hunan Normal University, Changsha, China
| | - Qi Sun
- College of Information Science and Engineering, Hunan Normal University, Changsha, China
| | - Junxia Zhao
- College of Information Science and Engineering, Hunan Normal University, Changsha, China
| | - Qian Xu
- College of Information Science and Engineering, Hunan Normal University, Changsha, China
| | - Liqin Wang
- College of Information Science and Engineering, Hunan Normal University, Changsha, China
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21
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Abstract
Amyloid fibrils are protein homopolymers that adopt diverse cross-β conformations. Some amyloid fibrils are associated with the pathogenesis of devastating neurodegenerative disorders, including Alzheimer's disease and Parkinson's disease. Conversely, functional amyloids play beneficial roles in melanosome biogenesis, long-term memory formation and release of peptide hormones. Here, we showcase advances in our understanding of amyloid assembly and structure, and how distinct amyloid strains formed by the same protein can cause distinct neurodegenerative diseases. We discuss how mutant steric zippers promote deleterious amyloidogenesis and aberrant liquid-to-gel phase transitions. We also highlight effective strategies to combat amyloidogenesis and related toxicity, including: (1) small-molecule drugs (e.g. tafamidis) to inhibit amyloid formation or (2) stimulate amyloid degradation by the proteasome and autophagy, and (3) protein disaggregases that disassemble toxic amyloid and soluble oligomers. We anticipate that these advances will inspire therapeutics for several fatal neurodegenerative diseases. Summary: This Review showcases important advances in our understanding of amyloid structure, assembly and disassembly, which are inspiring novel therapeutic strategies for amyloid disorders.
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Affiliation(s)
- Edward Chuang
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Pharmacology Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Acacia M Hori
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christina D Hesketh
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA .,Pharmacology Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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22
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Abstract
Senile plaques and neurofibrillary tangles are the principal histopathologic hallmarks of Alzheimer disease. The essential constituents of these lesions are structurally abnormal variants of normally generated proteins: Aβ protein in plaques and tau protein in tangles. At the molecular level, both proteins in a pathogenic state share key properties with classic prions, i.e., they consist of alternatively folded, β-sheet-rich forms of the proteins that autopropagate by the seeded corruption and self-assembly of like proteins. Other similarities with prions include the ability to manifest as polymorphic and polyfunctional strains, resistance to chemical and enzymatic destruction, and the ability to spread within the brain and from the periphery to the brain. In Alzheimer disease, current evidence indicates that the pathogenic cascade follows from the endogenous, sequential corruption of Aβ and then tau. Therapeutic options include reducing the production or multimerization of the proteins, uncoupling the Aβ-tauopathy connection, or promoting the inactivation or removal of anomalous assemblies from the brain. Although aberrant Aβ appears to be the prime mover of Alzheimer disease pathogenesis, once set in motion by Aβ, the prion-like propagation of tauopathy may proceed independently of Aβ; if so, Aβ might be solely targeted as an early preventive measure, but optimal treatment of Alzheimer disease at later stages of the cascade could require intervention in both pathways.
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Affiliation(s)
- Lary C Walker
- Department of Neurology and Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States.
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23
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Real-time monitoring of amyloid fibrillation by electrical impedance spectroscopy. Colloids Surf B Biointerfaces 2017; 160:724-731. [DOI: 10.1016/j.colsurfb.2017.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 09/29/2017] [Accepted: 10/03/2017] [Indexed: 12/29/2022]
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24
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Huy PDQ, Thai NQ, Bednarikova Z, Phuc LH, Linh HQ, Gazova Z, Li MS. Bexarotene Does Not Clear Amyloid Beta Plaques but Delays Fibril Growth: Molecular Mechanisms. ACS Chem Neurosci 2017; 8:1960-1969. [PMID: 28689412 DOI: 10.1021/acschemneuro.7b00107] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In 2012, it was reported that anticancer drug bexarotene reduced amyloid plaque and improved mental functioning in a small sample of mice engineered to exhibit Alzheimer's like symptoms. It has been suggested that bexarotene stimulates expression of apolipoprotein E (ApoE) leading to intracellular clearance of amyloid beta (Aβ). However, the effect of bexarotene on clearance of plaques has not been seen in some mouse models. Two interesting questions include whether bexarotene can destroy Aβ fibrils via direct interaction with them and how this compound impacts the lag phase in the fibril growth process. By the Thioflavin T fluorescence assay and atomic force microscopy, we have shown that bexarotene prolongs the lag phase, but it does not degrade Aβ fibrils. The impotence of bexarotene in destroying fibrils means that this compound is weakly bound to Aβ. On the other hand, the weak binding would prevent bexarotene from prolonging the lag phase. Thus, our two main in vitro observations seem to contradict each other. In order to settle this problem at the atomic level, we have performed all-atom molecular dynamics simulations in explicit water. We have demonstrated that bexarotene is not capable to reduce amyloid deposits due to weak binding to Aβ fibrils. However, it delays the self-assembly through reduction of the β-content of Aβ monomers at high enough ligand concentrations. Bexarotene is the first compound which displays such an unusual behavior. We have also shown that bexarotene has a low binding propensity to Aβ monomer and dimer.
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Affiliation(s)
- Pham Dinh Quoc Huy
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
- Institute for Computational Science and Technology, Quang Trung Software City, Tan Chanh Hiep Ward,
District 12, Ho Chi Minh City, Vietnam
| | - Nguyen Quoc Thai
- Division of Theoretical Physics, Dong Thap University, 783 Pham Huu Lau Street, Ward 6, Cao Lanh
City, Dong Thap, Vietnam
- Biomedical Engineering Department, University of Technology, VNU HCM
268 Ly Thuong Kiet Street, District 10, Ho
Chi Minh City, Vietnam
| | - Zuzana Bednarikova
- Department of Theoretical
Physics, University of Natural Sciences, VNU, 227 Nguyen Van Cu,
District 5, Ho Chi Minh City, Vietnam
| | - Le Huu Phuc
- Department of Biophysics Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040
01 Kosice, Slovakia
| | - Huynh Quang Linh
- Biomedical Engineering Department, University of Technology, VNU HCM
268 Ly Thuong Kiet Street, District 10, Ho
Chi Minh City, Vietnam
| | - Zuzana Gazova
- Department of Theoretical
Physics, University of Natural Sciences, VNU, 227 Nguyen Van Cu,
District 5, Ho Chi Minh City, Vietnam
| | - Mai Suan Li
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
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Major Reaction Coordinates Linking Transient Amyloid-β Oligomers to Fibrils Measured at Atomic Level. Biophys J 2017; 113:805-816. [PMID: 28834717 DOI: 10.1016/j.bpj.2017.06.068] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/22/2017] [Accepted: 06/22/2017] [Indexed: 11/22/2022] Open
Abstract
The structural underpinnings for the higher toxicity of the oligomeric intermediates of amyloidogenic peptides, compared to the mature fibrils, remain unknown at present. The transient nature and heterogeneity of the oligomers make it difficult to follow their structure. Here, using vibrational and solid-state nuclear magnetic resonance spectroscopy, and molecular dynamics simulations, we show that freely aggregating Aβ40 oligomers in physiological solutions have an intramolecular antiparallel configuration that is distinct from the intermolecular parallel β-sheet structure observed in mature fibrils. The intramolecular hydrogen-bonding network flips nearly 90°, and the two β-strands of each monomeric unit move apart, to give rise to the well-known intermolecular in-register parallel β-sheet structure in the mature fibrils. Solid-state nuclear magnetic resonance distance measurements capture the interstrand separation within monomer units during the transition from the oligomer to the fibril form. We further find that the D23-K28 salt-bridge, a major feature of the Aβ40 fibrils and a focal point of mutations linked to early onset Alzheimer's disease, is not detectable in the small oligomers. Molecular dynamics simulations capture the correlation between changes in the D23-K28 distance and the flipping of the monomer secondary structure between antiparallel and parallel β-sheet architectures. Overall, we propose interstrand separation and salt-bridge formation as key reaction coordinates describing the structural transition of the small Aβ40 oligomers to fibrils.
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26
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Jang JY, Cho H, Park HY, Rhim H, Kang S. ALS-linked mutant SOD1 proteins promote Aβ aggregates in ALS through direct interaction with Aβ. Biochem Biophys Res Commun 2017; 493:697-707. [PMID: 28864422 DOI: 10.1016/j.bbrc.2017.08.127] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 08/28/2017] [Indexed: 12/16/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive degeneration of motor neurons. Aggregation of ALS-linked mutant Cu/Zn superoxide dismutase (SOD1) is a hallmark of a subset of familial ALS (fALS). Recently, intracellular amyloid-β (Aβ) is detected in motor neurons of both sporadic and familial ALS. We have previously shown that intracellular Aβ specifically interacts with G93A, an ALS-linked SOD1 mutant. However, little is known about the pathological and biological effect of this interaction in neurons. In this study, we have demonstrated that the Aβ-binding region is exposed on the SOD1 surface through the conformational changes due to misfolding of SOD1. Interestingly, we found that the intracellular aggregation of Aβ is enhanced through the direct interaction of Aβ with the Aβ-binding region exposed to misfolded SOD1. Ultimately, increased Aβ aggregation by this interaction promotes neuronal cell death. Consistent with this result, Aβ aggregates was three-fold higher in the brains of G93A transgenic mice than those of non Tg. Our study provides the first direct evidence that Aβ, an AD-linked factor, is associated to the pathogenesis of ALS and provides molecular clues to understand common aggregation mechanisms in the pathogenesis of neurodegenerative diseases. Furthermore, it will provide new insights into the development of therapeutic approaches for ALS.
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Affiliation(s)
- Ja-Young Jang
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Hyungmin Cho
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Hye-Yoon Park
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Hyangshuk Rhim
- Department of Medical Life Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
| | - Seongman Kang
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea.
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27
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Thai NQ, Nguyen HL, Linh HQ, Li MS. Protocol for fast screening of multi-target drug candidates: Application to Alzheimer's disease. J Mol Graph Model 2017; 77:121-129. [PMID: 28850894 DOI: 10.1016/j.jmgm.2017.08.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 08/03/2017] [Accepted: 08/04/2017] [Indexed: 01/08/2023]
Abstract
The treatment of many diseases may require drugs that are capable to attack multiple targets simultaneously. Obviously, the virtual screening of multi-target drug candidates is much more time consuming compared to the single-target case. This, in particular, concerns the last step of virtual screening where the binding free energy is computed by conventional molecular dynamics simulation. To overcome this difficulty we propose a simple protocol which is relied on the fast steered molecular dynamics simulation and on available experimental data on binding affinity of reference ligand to a given target. Namely, first we compute non-equilibrium works generated during pulling ligands from the binding site using the steered molecular dynamics method. Then as top leads we choose only those compounds that have the non-equilibrium work larger than that of a reference compound for which the binding free energy has been already known from experiment. Despite many efforts no cures for AD (Alzheimer's disease) have been found. One of possible reasons for this failure is that drug candidates were developed for a single target, while there are exist many possible pathways to AD. Applying our new protocol to five targets including amyloid beta fibril, peroxisome proliferator-activated receptor γ, retinoic X receptor α, β- and γ-secretases, we have found two potential drugs (CID 16040294 and CID 9998128) for AD from the large PubChem database. We have also shown that these two ligands can interfere with the activity of popular Acetylcholinesterase target through strong binding towards it.
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Affiliation(s)
- Nguyen Quoc Thai
- Institute for Computational Sciences and Technology,SBI building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Viet Nam; Dong Thap University,783 Pham Huu Lau Street, Ward 6, Cao Lanh City, Dong Thap, Viet Nam; Biomedical Engineering Department, University of Technology -VNU HCM, 268 Ly Thuong Kiet Str., Distr. 10, Ho Chi Minh City, Viet Nam
| | - Hoang Linh Nguyen
- Institute for Computational Sciences and Technology,SBI building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Viet Nam
| | - Huynh Quang Linh
- Biomedical Engineering Department, University of Technology -VNU HCM, 268 Ly Thuong Kiet Str., Distr. 10, Ho Chi Minh City, Viet Nam
| | - Mai Suan Li
- Institute for Computational Sciences and Technology,SBI building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Viet Nam; Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland.
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28
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Mathis CA, Lopresti BJ, Ikonomovic MD, Klunk WE. Small-molecule PET Tracers for Imaging Proteinopathies. Semin Nucl Med 2017; 47:553-575. [PMID: 28826526 DOI: 10.1053/j.semnuclmed.2017.06.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In this chapter, we provide a review of the challenges and advances in developing successful PET imaging agents for 3 major types of aggregated amyloid proteins: amyloid-beta (Aβ), tau, and alpha-synuclein (α-syn). These 3 amyloids are involved in the pathogenesis of a variety of neurodegenerative diseases, referred to as proteinopathies or proteopathies, that include Alzheimer disease, Lewy body dementias, multiple system atrophy, and frontotemporal dementias, among others. In the Introduction section, we briefly discuss the history of amyloid in neurodegenerative diseases and describe why progress in developing effective imaging agents has been hampered by the failure of crystallography to provide definitive ligand-protein interactions for rational radioligand design efforts. Instead, the field has relied on largely serendipitous, trial-and-error methods to achieve useful and specific PET amyloid imaging tracers for Aβ, tau, and α-syn deposits. Because many of the proteopathies involve more than 1 amyloid protein, it is important to develop selective PET tracers for the different amyloids to help assess the relative contribution of each to total amyloid burden. We use Pittsburgh compound B to illustrate some of the critical steps in developing a potent and selective Aβ PET imaging agent. Other selective Aβ and tau PET imaging compounds have followed similar pathways in their developmental processes. Success for selective α-syn PET imaging agents has not been realized yet, but work is ongoing in multiple laboratories throughout the world. In the tau sections, we provide background regarding 3-repeat (3R) and 4-repeat (4R) tau proteins and how they can affect the binding of tau radioligands in different tauopathies. We review the ongoing efforts to assess the properties of tau ligands, which are useful in 3R, 4R, or combined 3R-4R tauopathies. Finally, we describe in the α-syn sections recent attempts to develop selective tracers to image α-synucleinopathies.
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Affiliation(s)
- Chester A Mathis
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA.
| | - Brian J Lopresti
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Milos D Ikonomovic
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - William E Klunk
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA
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Abstract
The prion paradigm is increasingly invoked to explain the molecular pathogenesis of neurodegenerative diseases involving the misfolding and aggregation of proteins other than the prion protein (PrP). Extensive evidence from in vitro and in vivo studies indicates that misfolded and aggregated Aβ peptide, which is the probable molecular trigger for Alzheimer's disease, manifests all of the key characteristics of canonical mammalian prions. These features include a β-sheet rich architecture, tendency to polymerize into amyloid, templated corruption of like protein molecules, ability to form structurally and functionally variant strains, systematic spread by neuronal transport, and resistance to inactivation by heat and formaldehyde. In addition to Aβ, a growing body of research supports the view that the prion-like molecular transformation of specific proteins drives the onset and course of a remarkable variety of clinicopathologically diverse diseases. As such, the expanded prion paradigm could conceptually unify fundamental and translational investigations of these disorders.
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Affiliation(s)
- Jay Rasmussen
- a Department of Cellular Neurology , Hertie Institute for Clinical Brain Research, University of Tübingen , Tübingen , Germany.,b German Center for Neurodegenerative Diseases (DZNE) , Tübingen , Germany.,c Graduate Training Center of Neuroscience, University of Tübingen , Tübingen , Germany
| | - Mathias Jucker
- a Department of Cellular Neurology , Hertie Institute for Clinical Brain Research, University of Tübingen , Tübingen , Germany.,b German Center for Neurodegenerative Diseases (DZNE) , Tübingen , Germany
| | - Lary C Walker
- d Department of Neurology and Yerkes National Primate Research Center , Emory University , Atlanta , GA , USA
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Walker LC, Jucker M. The Exceptional Vulnerability of Humans to Alzheimer's Disease. Trends Mol Med 2017; 23:534-545. [PMID: 28483344 DOI: 10.1016/j.molmed.2017.04.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/22/2017] [Accepted: 04/04/2017] [Indexed: 12/31/2022]
Abstract
Like many humans, non-human primates deposit copious misfolded Aβ protein in the brain as they age. Nevertheless, the complete behavioral and pathologic phenotype of Alzheimer's disease, including Aβ plaques, neurofibrillary (tau) tangles, and dementia, has not yet been identified in a non-human species. Recent research suggests that the crucial link between Aβ aggregation and tauopathy is somehow disengaged in aged monkeys. Understanding why Alzheimer's disease fails to develop in species that are biologically proximal to humans could disclose new therapeutic targets in the chain of events leading to neurodegeneration and dementia.
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Affiliation(s)
- Lary C Walker
- Department of Neurology and Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA.
| | - Mathias Jucker
- Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, and the German Center for Neurodegenerative Diseases (DZNE), D-72076 Tübingen, Germany.
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31
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Wälti MA, Orts J, Riek R. Quenched hydrogen-deuterium exchange NMR of a disease-relevant Aβ(1-42) amyloid polymorph. PLoS One 2017; 12:e0172862. [PMID: 28319116 PMCID: PMC5358797 DOI: 10.1371/journal.pone.0172862] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 02/12/2017] [Indexed: 11/21/2022] Open
Abstract
Alzheimer’s disease is associated with the aggregation into amyloid fibrils of Aβ(1–42) and Aβ(1–40) peptides. Interestingly, these fibrils often do not obtain one single structure but rather show different morphologies, so-called polymorphs. Here, we compare quenched hydrogen-deuterium (H/D) exchange of a disease-relevant Aβ(1–42) fibril for which the 3D structure has been determined by solid-state NMR with H/D exchange previously determined on another structural polymorph. This comparison reveals secondary structural differences between the two polymorphs suggesting that the two polymorphisms can be classified as segmental polymorphs.
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Affiliation(s)
| | - Julien Orts
- Laboratorium für Physikalische Chemie, ETH Zürich, Zürich, Switzerland
| | - Roland Riek
- Laboratorium für Physikalische Chemie, ETH Zürich, Zürich, Switzerland
- * E-mail:
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32
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Bellucci L, Bussi G, Di Felice R, Corni S. Fibrillation-prone conformations of the amyloid-β-42 peptide at the gold/water interface. NANOSCALE 2017; 9:2279-2290. [PMID: 28124697 DOI: 10.1039/c6nr06010b] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Proteins in the proximity of inorganic surfaces and nanoparticles may undergo profound adjustments that trigger biomedically relevant processes, such as protein fibrillation. The mechanisms that govern protein-surface interactions at the molecular level are still poorly understood. In this work, we investigate the adsorption onto a gold surface, in water, of an amyloid-β (Aβ) peptide, which is the amyloidogenic peptide involved in Alzheimer's disease. The entire adsorption process, from the peptide in bulk water to its conformational relaxation on the surface, is explored by large-scale atomistic molecular dynamics (MD) simulations. We start by providing a description of the conformational ensemble of Aβ in solution by a 22 μs temperature replica exchange MD simulation, which is consistent with previous results. Then, we obtain a statistical description of how the peptide approaches the gold surface by multiple MD simulations, identifying the preferential gold-binding sites and giving a kinetic picture of the association process. Finally, relaxation of the Aβ conformations at the gold/water interface is performed by a 19 μs Hamiltonian-temperature replica exchange MD simulation. We find that the conformational ensemble of Aβ is strongly perturbed by the presence of the surface. In particular, at the gold/water interface the population of the conformers akin to amyloid fibrils is significantly enriched, suggesting that this extended contact geometry may promote fibrillation.
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Affiliation(s)
- Luca Bellucci
- Center S3, CNR Institute of Nanoscience, via Campi 213/A, 41125 Modena, Italy.
| | - Giovanni Bussi
- SISSA-Scuola Internazionale Superiore di Studi Avanzati, via Bonomea 265, 34136 Trieste, Italy
| | - Rosa Di Felice
- Center S3, CNR Institute of Nanoscience, via Campi 213/A, 41125 Modena, Italy. and Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA
| | - Stefano Corni
- Center S3, CNR Institute of Nanoscience, via Campi 213/A, 41125 Modena, Italy.
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MORISAKU T, YUI H. Structural Discrimination between Aβ(1–40) and Aβ(1–42) Peptides in Films with Vibrational Circular Dichroism Spectroscopy. ANAL SCI 2017; 33:79-82. [DOI: 10.2116/analsci.33.79] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Toshinori MORISAKU
- Department of Chemistry, Faculty of Science, Tokyo University of Science
| | - Hiroharu YUI
- Department of Chemistry, Faculty of Science, Tokyo University of Science
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Wu Q, Sun JX, Song XH, Wang J, Xiong CQ, Teng FX, Gao CX. Blocking beta 2-adrenergic receptor inhibits dendrite ramification in a mouse model of Alzheimer's disease. Neural Regen Res 2017; 12:1499-1506. [PMID: 29089997 PMCID: PMC5649472 DOI: 10.4103/1673-5374.215261] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Dendrite ramification affects synaptic strength and plays a crucial role in memory. Previous studies revealed a correlation between beta 2-adrenergic receptor dysfunction and Alzheimer's disease (AD), although the mechanism involved is still poorly understood. The current study investigated the potential effect of the selective β2-adrenergic receptor antagonist, ICI 118551 (ICI), on Aβ deposits and AD-related cognitive impairment. Morris water maze test results demonstrated that the performance of AD-transgenic (TG) mice treated with ICI (AD-TG/ICI) was significantly poorer compared with NaCl-treated AD-TG mice (AD-TG/NaCl), suggesting that β2-adrenergic receptor blockage by ICI might reduce the learning and memory abilities of mice. Golgi staining and immunohistochemical staining revealed that blockage of the β2-adrenergic receptor by ICI treatment decreased the number of dendritic branches, and ICI treatment in AD-TG mice decreased the expression of hippocampal synaptophysin and synapsin 1. Western blot assay results showed that the blockage of β2-adrenergic receptor increased amyloid-β accumulation by downregulating hippocampal α-secretase activity and increasing the phosphorylation of amyloid precursor protein. These findings suggest that blocking the β2-adrenergic receptor inhibits dendrite ramification of hippocampal neurons in a mouse model of AD.
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Affiliation(s)
- Qin Wu
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical College, Xuzhou, Jiangsu Province, China.,College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Jin-Xia Sun
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Xiang-He Song
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Jing Wang
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Cun-Quan Xiong
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Fei-Xiang Teng
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
| | - Cui-Xiang Gao
- College of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu Province, China
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35
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Structure of Crenezumab Complex with Aβ Shows Loss of β-Hairpin. Sci Rep 2016; 6:39374. [PMID: 27996029 PMCID: PMC5171940 DOI: 10.1038/srep39374] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 11/21/2016] [Indexed: 12/12/2022] Open
Abstract
Accumulation of amyloid-β (Aβ) peptides and amyloid plaque deposition in brain is postulated as a cause of Alzheimer's disease (AD). The precise pathological species of Aβ remains elusive although evidence suggests soluble oligomers may be primarily responsible for neurotoxicity. Crenezumab is a humanized anti-Aβ monoclonal IgG4 that binds multiple forms of Aβ, with higher affinity for aggregated forms, and that blocks Aβ aggregation, and promotes disaggregation. To understand the structural basis for this binding profile and activity, we determined the crystal structure of crenezumab in complex with Aβ. The structure reveals a sequential epitope and conformational requirements for epitope recognition, which include a subtle but critical element that is likely the basis for crenezumab's versatile binding profile. We find interactions consistent with high affinity for multiple forms of Aβ, particularly oligomers. Of note, crenezumab also sequesters the hydrophobic core of Aβ and breaks an essential salt-bridge characteristic of the β-hairpin conformation, eliminating features characteristic of the basic organization in Aβ oligomers and fibrils, and explains crenezumab's inhibition of aggregation and promotion of disaggregation. These insights highlight crenezumab's unique mechanism of action, particularly regarding Aβ oligomers, and provide a strong rationale for the evaluation of crenezumab as a potential AD therapy.
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