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Li Y, Awasthi S, Bryan L, Ehrlich RS, Tonali N, Balog S, Yang J, Sewald N, Mayer M. Fluorescence-Based Monitoring of Early-Stage Aggregation of Amyloid-β, Amylin Peptide, Tau, and α-Synuclein Proteins. ACS Chem Neurosci 2024; 15:3113-3123. [PMID: 39150403 PMCID: PMC11378287 DOI: 10.1021/acschemneuro.4c00097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 07/02/2024] [Accepted: 07/25/2024] [Indexed: 08/17/2024] Open
Abstract
Early-stage aggregates of amyloid-forming proteins, specifically soluble oligomers, are implicated in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. Protein aggregation is typically monitored by fluorescence using the amyloid-binding fluorophore thioflavin T (ThT). Thioflavin T interacts, however, preferentially with fibrillar amyloid structures rather than with soluble, early-stage aggregates. In contrast, the two fluorophores, aminonaphthalene 2-cyanoacrylate-spiropyran (AN-SP) and triazole-containing boron-dipyrromethene (taBODIPY), were reported to bind preferentially to early-stage aggregates of amyloidogenic proteins. The present study compares ThT with AN-SP and taBODIPY with regard to their ability to monitor early stages of aggregation of four different amyloid-forming proteins, including amyloid-β (Aβ), tau protein, amylin, and α-synuclein. The results show that the three fluorophores vary in their suitability to monitor the early aggregation of different amyloid-forming proteins. For instance, in the presence of Aβ and amylin, the fluorescence intensity of AN-SP increased at an earlier stage of aggregation than the fluorescence of ThT, albeit with only a small fluorescence increase in the case of AN-SP. In contrast, in the presence of tau and amylin, the fluorescence intensity of taBODIPY increased at an earlier stage of aggregation than the fluorescence of ThT. Finally, α-synuclein aggregation could only be monitored by ThT fluorescence; neither AN-SP nor taBODIPY showed a significant increase in fluorescence over the course of aggregation of α-synuclein. These results demonstrate the ability of AN-SP and taBODIPY to monitor the formation of early-stage aggregates from specific amyloid-forming proteins at an early stage of aggregation, although moderate increases in fluorescence intensity, relatively large uncertainties in fluorescence values, and limited solubility of both fluorophores limit their usefulness for some amyloid proteins. The capability to monitor early aggregation of some amyloid proteins, such as amylin, might accelerate the discovery of aggregation inhibitors to minimize the formation of toxic oligomeric species for potential therapeutic use.
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Affiliation(s)
- Yuanjie Li
- Adolphe
Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg CH-1700, Switzerland
| | - Saurabh Awasthi
- Adolphe
Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg CH-1700, Switzerland
- Department
of Biotechnology, National Institute of
Pharmaceutical Education and Research, Raebareli (NIPER-R), Lucknow, Uttar Pradesh 226002, India
| | - Louise Bryan
- Adolphe
Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg CH-1700, Switzerland
| | - Rachel S. Ehrlich
- Department
of Chemistry and Biochemistry, University
of California San Diego, La Jolla, California 92093-0358, United States
| | - Nicolo Tonali
- CNRS,
BioCIS, Bâtiment Henri Moissan, Université
Paris-Saclay, 17 Av. des Sciences, Orsay 91400, France
| | - Sandor Balog
- Adolphe
Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg CH-1700, Switzerland
| | - Jerry Yang
- Department
of Chemistry and Biochemistry, University
of California San Diego, La Jolla, California 92093-0358, United States
| | - Norbert Sewald
- Bielefeld
University, Department of Chemistry P.O. Box 100131, Bielefeld 33501, Germany
| | - Michael Mayer
- Adolphe
Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg CH-1700, Switzerland
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2
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Tang Y, Zhang Y, Zhang D, Liu Y, Nussinov R, Zheng J. Exploring pathological link between antimicrobial and amyloid peptides. Chem Soc Rev 2024; 53:8713-8763. [PMID: 39041297 DOI: 10.1039/d3cs00878a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
Amyloid peptides (AMYs) and antimicrobial peptides (AMPs) are considered as the two distinct families of peptides, characterized by their unique sequences, structures, biological functions, and specific pathological targets. However, accumulating evidence has revealed intriguing pathological connections between these peptide families in the context of microbial infection and neurodegenerative diseases. Some AMYs and AMPs share certain structural and functional characteristics, including the ability to self-assemble, the presence of β-sheet-rich structures, and membrane-disrupting mechanisms. These shared features enable AMYs to possess antimicrobial activity and AMPs to acquire amyloidogenic properties. Despite limited studies on AMYs-AMPs systems, the cross-seeding phenomenon between AMYs and AMPs has emerged as a crucial factor in the bidirectional communication between the pathogenesis of neurodegenerative diseases and host defense against microbial infections. In this review, we examine recent developments in the potential interplay between AMYs and AMPs, as well as their pathological implications for both infectious and neurodegenerative diseases. By discussing the current progress and challenges in this emerging field, this account aims to inspire further research and investments to enhance our understanding of the intricate molecular crosstalk between AMYs and AMPs. This knowledge holds great promise for the development of innovative therapies to combat both microbial infections and neurodegenerative disorders.
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Affiliation(s)
- Yijing Tang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Ohio 44325, USA.
| | - Yanxian Zhang
- Division of Endocrinology and Diabetes, Department of Pediatrics, School of Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Dong Zhang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Yonglan Liu
- Cancer Innovation Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
- Department of Human Molecular Genetics and Biochemistry Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Jie Zheng
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Ohio 44325, USA.
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3
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Xu Y, Filice CT, Leonenko Z. Protective effect of trehalose sugar on amyloid-membrane interactions using BLM electrophysiology. Biophys J 2024; 123:1690-1704. [PMID: 38751113 PMCID: PMC11213996 DOI: 10.1016/j.bpj.2024.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 04/10/2024] [Accepted: 05/13/2024] [Indexed: 05/30/2024] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by dementia and memory loss in the elderly population. The amyloid-β peptide (Aβ) is one of the main pathogenic factors in AD and is known to cause damage to neuronal cellular membranes. There is no cure currently available for AD, and new approaches, including preventive strategies, are highly desirable. In this work, we explore the possibility of protecting neuronal membranes from amyloid-induced damage with naturally existing sugar trehalose. Trehalose has been shown to protect plant cellular membranes in extreme conditions and modify Aβ misfolding. We hypothesize that trehalose can protect the neuronal membrane from amyloid toxicity. In this work, we studied the protective effect of trehalose against Aβ1-42-induced damage in model lipid membranes (DPPC/POPC/cholesterol) using atomic force microscopy and black lipid membrane electrophysiology. Our results demonstrate that Aβ1-42 damaged membranes and led to ionic current leakage across these membranes due to the formation of various defects and pores. The presence of trehalose reduced the ion current across membranes caused by Aβ1-42 peptide damage, thus efficiently protecting the membranes. These findings suggest that the trehalose sugar can potentially be useful in protecting neuronal membranes against amyloid toxicity in AD.
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Affiliation(s)
- Yue Xu
- Department of Physics & Astronomy, University of Waterloo, Waterloo, ON, Canada
| | - Carina Teresa Filice
- Department of Biology, University of Waterloo, Waterloo, ON, Canada; Waterloo Institute for Nanotechnology, Waterloo, ON, Canada
| | - Zoya Leonenko
- Department of Physics & Astronomy, University of Waterloo, Waterloo, ON, Canada; Department of Biology, University of Waterloo, Waterloo, ON, Canada; Waterloo Institute for Nanotechnology, Waterloo, ON, Canada.
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4
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Karkisaval AG, Hassan R, Nguyen A, Balster B, Abedin F, Lal R, Tatulian SA. The structure of tyrosine-10 favors ionic conductance of Alzheimer's disease-associated full-length amyloid-β channels. Nat Commun 2024; 15:1296. [PMID: 38351257 PMCID: PMC10864385 DOI: 10.1038/s41467-023-43821-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 11/21/2023] [Indexed: 02/16/2024] Open
Abstract
Amyloid β (Aβ) ion channels destabilize cellular ionic homeostasis, which contributes to neurotoxicity in Alzheimer's disease. The relative roles of various Aβ isoforms are poorly understood. We use bilayer electrophysiology, AFM imaging, circular dichroism, FTIR and fluorescence spectroscopy to characterize channel activities of four most prevalent Aβ peptides, Aβ1-42, Aβ1-40, and their pyroglutamylated forms (AβpE3-42, AβpE3-40) and correlate them with the peptides' structural features. Solvent-induced fluorescence splitting of tyrosine-10 is discovered and used to assess the sequestration from the solvent and membrane insertion. Aβ1-42 effectively embeds in lipid membranes, contains large fraction of β-sheet in a β-barrel-like structure, forms multi-subunit pores in membranes, and displays well-defined ion channel features. In contrast, the other peptides are partially solvent-exposed, contain minimal β-sheet structure, form less-ordered assemblies, and produce irregular ionic currents. These findings illuminate the structural basis of Aβ neurotoxicity through membrane permeabilization and may help develop therapies that target Aβ-membrane interactions.
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Affiliation(s)
- Abhijith G Karkisaval
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA
| | - Rowan Hassan
- Department of Physics, University of Central Florida, Orlando, FL, USA
| | - Andrew Nguyen
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Benjamin Balster
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Faisal Abedin
- Department of Physics, University of Central Florida, Orlando, FL, USA
- Department of Biology, Xavier University of Louisiana, New Orleans, LA, USA
| | - Ratnesh Lal
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA.
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA.
| | - Suren A Tatulian
- Department of Physics, University of Central Florida, Orlando, FL, USA.
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5
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Tang Y, Zhang D, Robinson S, Zheng J. Inhibition of Pancreatic Cancer Cells by Different Amyloid Proteins Reveals an Inverse Relationship between Neurodegenerative Diseases and Cancer. Adv Biol (Weinh) 2023; 7:e2300070. [PMID: 37080947 DOI: 10.1002/adbi.202300070] [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: 02/10/2023] [Revised: 03/22/2023] [Indexed: 04/22/2023]
Abstract
Neurodegenerative diseases and cancers are considered to be two families of diseases caused by completely opposite cell-death mechanisms: the former caused by premature cell death, with the latter due to the increased resistance to cell death. Growing epidemiologic evidence appear to suggest an inverse correlation between neurodegenerative diseases and cancers. However, pathological links, particularly from a protein-cell interaction perspective, between these two families of diseases remains to be proven. Here, a fundamental study investigates the effects of three amyloid proteins of Aβ (associated with AD), hIAPP (associated with T2D), and hCT (associated with MTC) on pancreatic cancer (PANC-1) cells. Collective results demonstrate a general inhibitory activity of all of three amyloid proteins on cancer cell proliferation, but inhibition efficiencies are strongly dependent on amyloid sequence (Aβ, hIAPP, hCT), concentration (IC25, IC50, IC75), and aggregation states (monomers, oligomers). Amyloid proteins exhibit two pathways against cancer cells: amyloid monomer-induced ROS production to inhibit cell growth and amyloid oligomer-induced membrane disruption to kill cells. Collectively, the results demonstrate a general inhibition function of amyloid proteins to induce cancer cell death by preventing cell proliferation, suppressing cell migration, promoting reactive oxygen species production, and disrupting cell membranes.
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Affiliation(s)
- Yijing Tang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, OH, 44325, USA
| | - Dong Zhang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, OH, 44325, USA
| | - Sarah Robinson
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, OH, 44325, USA
| | - Jie Zheng
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, OH, 44325, USA
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6
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Khayer N, Motamed N, Marashi SA, Goshadrou F. RT-DOb, a switch gene for the gene pair {Csf1r, Milr1}, can influence the onset of Alzheimer's disease by regulating communication between mast cell and microglia. PLoS One 2023; 18:e0288134. [PMID: 37410787 DOI: 10.1371/journal.pone.0288134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 06/20/2023] [Indexed: 07/08/2023] Open
Abstract
In biology, homeostasis is a central cellular phenomenon that plays a crucial role in survival. The central nervous system (CNS) is controlled by exquisitely sensitive homeostatic mechanisms when facing inflammatory or pathological insults. Mast cells and microglia play a crucial role in CNS homeostasis by eliminating damaged or unnecessary neurons and synapses. Therefore, decoding molecular circuits that regulate CNS homeostasis may lead to more effective therapeutic strategies that specifically target particular subsets for better therapy of Alzheimer's disease (AD). Based on a computational analysis of a microarray dataset related to AD, the H2-Ob gene was previously identified as a potential modulator of the homeostatic balance between mast cells and microglia. Specifically, it plays such a role in the presence of a three-way gene interaction in which the H2-Ob gene acts as a switch in the co-expression relationship of two genes, Csf1r and Milr1. Therefore, the importance of the H2-Ob gene as a potential therapeutic target for AD has led us to experimentally validate this relationship using the quantitative real-time PCR technique. In the experimental investigation, we confirmed that a change in the expression levels of the RT1-DOb gene (the rat ortholog of murine H2-Ob) can switch the co-expression relationship between Csf1r and Milr1. Furthermore, since the RT1-DOb gene is up-regulated in AD, the mentioned triplets might be related to triggering AD.
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Affiliation(s)
- Nasibeh Khayer
- Skull Base Research Center, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Nasrin Motamed
- Department of Cellular and Molecular Biology, School of Biology, University of Tehran, Tehran, Iran
| | - Sayed-Amir Marashi
- Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran
| | - Fatemeh Goshadrou
- Department of Basic Sciences, Faculty of Paramedical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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7
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Young KA, Mancera RL. Review: Investigating the aggregation of amyloid beta with surface plasmon resonance: Do different approaches yield different results? Anal Biochem 2022; 654:114828. [PMID: 35931183 DOI: 10.1016/j.ab.2022.114828] [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: 03/22/2022] [Revised: 07/17/2022] [Accepted: 07/19/2022] [Indexed: 11/30/2022]
Abstract
Aggregation of amyloid beta into amyloid plaques in the brain is a hallmark characteristic of Alzheimer's disease. Therapeutics aimed at preventing or retarding amyloid formation often rely on detailed characterization of the underlying mechanism and kinetics of protein aggregation. Surface plasmon resonance (SPR) spectroscopy is a robust technique used to determine binding affinity and kinetics of biomolecular interactions. This approach has been used to characterize the mechanism of aggregation of amyloid beta but there are multiple pitfalls that need to be addressed when working with this and other amyloidogenic proteins. The choice of method for analyte preparation and ligand immobilization to a sensor chip can lead to different theoretical and practical implications in terms of the mathematical modelling of binding data, different mechanisms of binding and the presence of different interacting species. This review examines preparation methods for SPR characterisation of the aggregation of amyloid beta and their influence on the findings derived from such studies.
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Affiliation(s)
- Kimberly A Young
- Curtin Medical School, Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Ricardo L Mancera
- Curtin Medical School, Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.
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8
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Fini H, Hassan Q, Noroozifar M, Kerman K. Electrografting a Hybrid Bilayer Membrane via Diazonium Chemistry for Electrochemical Impedance Spectroscopy of Amyloid-β Aggregation. MICROMACHINES 2022; 13:574. [PMID: 35457879 PMCID: PMC9029378 DOI: 10.3390/mi13040574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/20/2022] [Accepted: 03/24/2022] [Indexed: 11/23/2022]
Abstract
Herein, a novel hybrid bilayer membrane is introduced as a platform to study the aggregation of amyloid-β1-42 (Aβ1-42) peptide on surfaces. The first layer was covalently attached to a glassy carbon electrode (GCE) via diazonium electrodeposition, which provided a highly stable template for the hybrid bilayer formation. To prepare the long-chain hybrid bilayer membrane (lcHBLM)-modified electrodes, GCE surfaces were modified with 4-dodecylbenzenediazonium (DDAN) followed by the modification with dihexadecyl phosphate (DHP) as the second layer. For the preparation of short-chain hybrid bilayer membrane (scHBLM)-modified electrodes, GCE surfaces were modified with 4-ethyldiazonium (EDAN) as the first layer and bis(2-ethylhexyl) phosphate (BEHP) was utilized as the second layer. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used to characterize the bilayer formation. Both positively charged [Ru(NH3)6]3+ and negatively charged ([Fe(CN)6]3-/4-) redox probes were used for electrochemical characterization of the modified surfaces using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). EIS results showed a decrease in charge transfer resistance (Rct) upon incubation of Aβ1-42 on the hybrid bilayer-modified surfaces. This framework provides a promising electrochemical platform for designing hybrid bilayers with various physicochemical properties to study the interaction of membrane-bound receptors and biomolecules on surfaces.
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Budvytyte R, Ambrulevičius F, Jankaityte E, Valincius G. Electrochemical Assessment of Dielectric Damage to Phospholipid Bilayers by Amyloid β-Oligomers. Bioelectrochemistry 2022; 145:108091. [DOI: 10.1016/j.bioelechem.2022.108091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/23/2022] [Accepted: 02/24/2022] [Indexed: 11/02/2022]
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10
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Tang Y, Zhang D, Gong X, Zheng J. A mechanistic survey of Alzheimer's disease. Biophys Chem 2021; 281:106735. [PMID: 34894476 DOI: 10.1016/j.bpc.2021.106735] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/26/2021] [Accepted: 11/26/2021] [Indexed: 02/06/2023]
Abstract
Alzheimer's disease (AD) is the most common, age-dependent neurodegenerative disorder. While AD has been intensively studied from different aspects, there is no effective cure for AD, largely due to a lack of a clear mechanistic understanding of AD. In this mini-review, we mainly focus on the discussion and summary of mechanistic causes of Alzheimer's disease (AD). While different AD mechanisms illustrate different molecular and cellular pathways in AD pathogenesis, they do not necessarily exclude each other. Instead, some of them could work together to initiate, trigger, and promote the onset and development of AD. In a broader viewpoint, some AD mechanisms (e.g., amyloid aggregation mechanism, microbial infection/neuroinflammation mechanism, and amyloid cross-seeding mechanism) could also be applicable to other amyloid diseases including type II diabetes, Parkinson's disease, and prion disease. Such common mechanisms for AD and other amyloid diseases explain not only the pathogenesis of individual amyloid diseases, but also the spreading of pathologies between these diseases, which will inspire new strategies for therapeutic intervention and prevention for AD.
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Affiliation(s)
- Yijing Tang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, OH, United States of America
| | - Dong Zhang
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, OH, United States of America
| | - Xiong Gong
- Department of Polymer Engineering, The University of Akron, OH, United States of America
| | - Jie Zheng
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, OH, United States of America.
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Kim M, Son J, Kim Y. NMR Studies of the Ion Channel-Forming Human Amyloid-β with Zinc Ion Concentrations. MEMBRANES 2021; 11:membranes11110799. [PMID: 34832029 PMCID: PMC8620595 DOI: 10.3390/membranes11110799] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/06/2021] [Accepted: 10/14/2021] [Indexed: 11/16/2022]
Abstract
Alzheimer’s disease (AD) is classified as an amyloid-related disease. Amyloid beta (Aβ) is a transmembrane protein known to play a major role in the pathogenesis of AD. These Aβ proteins can form ion channels or pores in the cell membrane. Studies have elucidated the structure of the transmembrane domain of Aβ ion channels. In addition, various studies have investigated substances that block or inhibit the formation of Aβ ion channels. Zinc ions are considered as potential inhibitors of AD. In this study, we focused on the transmembrane domain and some external domains of the Aβ protein (hAPP-TM), and solution-state NMR was used to confirm the effect on residues of the protein in the presence of zinc ions. In addition, we sought to confirm the structure and orientation of the protein in the presence of the bicelle using solid-state NMR.
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Affiliation(s)
| | | | - Yongae Kim
- Correspondence: ; Tel.: +82-31-330-4604; Fax: +82-31-330-4566
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Trzeciak P, Herbet M, Dudka J. Common Factors of Alzheimer's Disease and Rheumatoid Arthritis-Pathomechanism and Treatment. Molecules 2021; 26:6038. [PMID: 34641582 PMCID: PMC8512006 DOI: 10.3390/molecules26196038] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/20/2021] [Accepted: 09/29/2021] [Indexed: 11/17/2022] Open
Abstract
The accumulation of amyloid plaques, or misfolded fragments of proteins, leads to the development of a condition known as amyloidosis, which is clinically recognized as a systemic disease. Amyloidosis plays a special role in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease, and rheumatoid arthritis (RA). The occurrence of amyloidosis correlates with the aging process of the organism, and since nowadays, old age is determined by the comfort of functioning and the elimination of unpleasant disease symptoms in the elderly, exposure to this subject is justified. In Alzheimer's disease, amyloid plaques negatively affect glutaminergic and cholinergic transmission and loss of sympathetic protein, while in RA, amyloids stimulated by the activity of the immune system affect the degradation of the osteoarticular bond. The following monograph draws attention to the over-reactivity of the immune system in AD and RA, describes the functionality of the blood-brain barrier as an intermediary medium between RA and AD, and indicates the direction of research to date, focusing on determining the relationship and the cause-effect link between these disorders. The paper presents possible directions for the treatment of amyloidosis, with particular emphasis on innovative therapies.
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Affiliation(s)
| | - Mariola Herbet
- Chair and Department of Toxicology, Faculty of Pharmacy, Medical University of Lublin, Jaczewskiego 8b Street, 20-090 Lublin, Poland; (P.T.)
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Guo JL, Diaz-Gomez L, Xie VY, Bittner SM, Jiang EY, Wang B, Mikos AG. Three-Dimensional Printing of Click Functionalized, Peptide Patterned Scaffolds for Osteochondral Tissue Engineering. ACTA ACUST UNITED AC 2021; 22. [PMID: 33997430 DOI: 10.1016/j.bprint.2021.e00136] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Osteochondral repair remains a significant clinical challenge due to the multiple tissue phenotypes and complex biochemical milieu in the osteochondral unit. To repair osteochondral defects, it is necessary to mimic the gradation between bone and cartilage, which requires spatial patterning of multiple tissue-specific cues. To address this need, we have developed a facile system for the conjugation and patterning of tissue-specific peptides by melt extrusion of peptide-functionalized poly(ε-caprolactone) (PCL). In this study, alkyne-terminated PCL was conjugated to tissue-specific peptides via a mild, aqueous, and Ru(II)-catalyzed click reaction. The PCL-peptide composites were then 3D printed by multimaterial segmented printing to generate user-defined patterning of tissue-specific peptides. To confirm the bioactivity of 3D printed PCL-peptide composites, bone- and cartilage-specific scaffolds were seeded with mesenchymal stem cells and assessed for deposition of tissue-specific extracellular matrix in vitro. PCL-peptide scaffolds successfully promoted osteogenic and chondrogenic matrix deposition, with effects dependent on the identity of conjugated peptide.
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Affiliation(s)
- Jason L Guo
- Department of Bioengineering, Rice University, Houston, TX
| | | | - Virginia Y Xie
- Department of Bioengineering, Rice University, Houston, TX
| | - Sean M Bittner
- Department of Bioengineering, Rice University, Houston, TX
| | - Emily Y Jiang
- Department of Bioengineering, Rice University, Houston, TX
| | - Bonnie Wang
- Department of Bioengineering, Rice University, Houston, TX
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14
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Shi JM, Zhu L, Lan X, Zhao DW, He YJ, Sun ZQ, Wu D, Li HY. Endocytosis Is a Key Mode of Interaction between Extracellular β-Amyloid and the Cell Membrane. Biophys J 2020; 119:1078-1090. [PMID: 32857960 PMCID: PMC7499104 DOI: 10.1016/j.bpj.2020.07.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/21/2020] [Accepted: 07/08/2020] [Indexed: 11/23/2022] Open
Abstract
Interactions between amyloid-β peptide (Aβ) and the cell membrane include interaction with membrane lipids and binding to membrane receptors, both of which are considered to be the toxicity mechanisms of Aβ. However, it is unclear whether both mechanisms lead to cytotoxicity. Thus, we aimed to analyze these two mechanisms of Aβ42 interaction with cell membranes under different Aβ aggregation states. To this end, model membrane experiments were conducted. Quantitative analysis of Aβ42 monomers or oligomers bound to the membrane of neuro-2a cells was also performed, and laser confocal microscopy was employed to assess endocytosis of FITC-Aβ42 monomers or oligomers by neuro-2a cells. We found that the binding capacity of Aβ42 to membrane lipids was weak and that the amount of Aβ42 bound to membrane lipids was low. Moreover, clathrin-mediated endocytosis of Aβ42 oligomers by neuro-2a cells was observed. Endocytosis serves as a key mode of interaction between extracellular Aβ42 and neurons. These findings provide insights into the mechanisms underlying Aβ oligomer metabolism.
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Affiliation(s)
- Jing-Ming Shi
- School of Medicine, Xizang Minzu University, Xian' yang, Shaanxi, P.R. China
| | - Li Zhu
- School of Life Sciences, Lanzhou University, Lanzhou, P.R. China
| | - Xi Lan
- MOE Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China
| | - Duan-Wei Zhao
- Gansu Provincial Institute of Drug Control, Lanzhou, P.R. China
| | - Yong-Jun He
- School of Medicine, Xizang Minzu University, Xian' yang, Shaanxi, P.R. China
| | - Zheng-Qi Sun
- School of Medicine, Xizang Minzu University, Xian' yang, Shaanxi, P.R. China
| | - Di Wu
- School of Life Sciences, Lanzhou University, Lanzhou, P.R. China
| | - Hai-Yun Li
- MOE Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
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15
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Jang HY, Shin JY, Oh SH, Byun JH, Lee JH. PCL/HA Hybrid Microspheres for Effective Osteogenic Differentiation and Bone Regeneration. ACS Biomater Sci Eng 2020; 6:5172-5180. [PMID: 33455267 DOI: 10.1021/acsbiomaterials.0c00550] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The purpose of this study is to develop a bioactive bone graft based on polycaprolactone (PCL, synthetic polymer; used in clinical practices as a grafting material for craniofacial bone defects) and hyaluronic acid (HA, bioactive natural polymer; known as a promoting substance for bone regeneration) that would be fabricated by clinically available procedures (mild condition without toxic chemicals) and provide bioactivity for sufficient period, and thus effectively induce bone reconstruction. For this, PCL/HA hybrid microspheres were produced by a spray-precipitation technique using clinically adapted solvents. The HA was stably and evenly entrapped in the PCL/HA hybrid microspheres. It was demonstrated that the PCL/HA hybrid microspheres provide an appropriate environment for proliferation and osteogenic differentiation of human periosteum-derived cells (hPDCs) (in vitro) and allow significantly enhanced bone regeneration (in vivo) compared with PCL microspheres without HA. The PCL/HA hybrid microspheres can be a simple but clinically applicable bioactive bone graft for large-sized bone defects.
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Affiliation(s)
- Hee Yun Jang
- Department of Advanced Materials, Hannam University, Daejeon 34054, Republic of Korea
| | - Jun Yung Shin
- Department of Advanced Materials, Hannam University, Daejeon 34054, Republic of Korea
| | - Se Heang Oh
- Department of Nanobiomedical Science, Dankook University, Cheonan 31116, Republic of Korea.,Center for Bio-Medical Engineering Core Facility, Dankook University, Cheonan 31116, Republic of Korea
| | - June-Ho Byun
- Department of Oral and Maxillofacial Surgery, Gyeongsang National University School of Medicine, Gyeongsang National University Hospital, Institute of Health Sciences, Gyeongsang National University, Jinju 52727, Republic of Korea
| | - Jin Ho Lee
- Department of Advanced Materials, Hannam University, Daejeon 34054, Republic of Korea
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16
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Highlighting the effect of amyloid beta assemblies on the mechanical properties and conformational stability of cell membrane. J Mol Graph Model 2020; 100:107670. [PMID: 32711259 DOI: 10.1016/j.jmgm.2020.107670] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 01/05/2023]
Abstract
Alzheimer disease (AD) is the most common cause of dementia, characterized by a progressive decline in cognitive function due to the abnormal aggregation and deposition of Amyloid beta (Aβ) fibrils in the brain of patients. In this context, the molecular mechanisms of protein misfolding and aggregation that are known to induce significant biophysical alterations in cells, including destabilization of plasma membranes, remain partially unclear. Physical interaction between the Aβ assemblies and the membrane leads to the disruption of the cell membrane in multiple ways including, surface carpeting, generation of transmembrane channels and detergent-like membrane dissolution. Understanding the impact of amyloidogenic protein in different stages of aggregation with the plasma membrane, plays a crucial role to fully elucidate the pathological mechanisms of AD. Within this framework, computer simulations represent a powerful tool able to shed lights on the interactions governing the structural influence of Aβ proteins on biological membrane. In this study, molecular dynamics (MD) simulations have been performed in order to characterize how POPC bilayer conformational and mechanical properties are affected by the interaction with Aβ11-42 peptide, oligomer and fibril.
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17
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Teppang KL, Ehrlich RS, Yang J. Method to discriminate amyloids using fluorescent probes. Methods Enzymol 2020; 639:91-114. [PMID: 32475414 DOI: 10.1016/bs.mie.2020.04.010] [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: 03/11/2023]
Abstract
The aggregation of misfolded proteins into amyloids is a common characteristic of many neurodegenerative and non-neurologic diseases. Fluorescent amyloid-targeting probes that discriminate amyloids based on differences in protein composition can provide rapid information to aid in disease diagnosis. In this chapter, we present protocols for the synthesis and use of ANCA-11 as an environmentally-sensitive amyloid-targeting probe that can fluorescently discriminate between amyloids with different disease origin. We also present a protocol for preparing amyloid samples of synthetic Amyloid-β(1-42), as problems with amyloid preparations can be a large driver of time and cost for research. The methods presented here can be generalized for evaluation of other amyloid-targeting fluorescent probes with different aggregates of amyloidogenic proteins in solution or in tissue.
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Affiliation(s)
- Kristine L Teppang
- Department of Chemistry and Biochemistry, University of California, San Diego, CA, United States
| | - Rachel S Ehrlich
- Department of Chemistry and Biochemistry, University of California, San Diego, CA, United States
| | - Jerry Yang
- Department of Chemistry and Biochemistry, University of California, San Diego, CA, United States.
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18
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Vander Zanden CM, Wampler L, Bowers I, Watkins EB, Majewski J, Chi EY. Fibrillar and Nonfibrillar Amyloid Beta Structures Drive Two Modes of Membrane-Mediated Toxicity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:16024-16036. [PMID: 31509701 PMCID: PMC7385729 DOI: 10.1021/acs.langmuir.9b02484] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In Alzheimer's disease, the amyloid-beta peptide (Aβ) is implicated in neuronal toxicity via interactions with the cell membrane. Monomeric Aβ (Aβm) is intrinsically disordered, but it can adopt a range of aggregated conformations with varying toxicities from short fibrillar oligomers (FO), to globular nonfibrillar oligomers (NFO), and full-length amyloid fibrils. NFO is considered to be the most toxic, followed by fibrils, and finally Aβm. To elucidate molecular-level membrane interactions that contribute to their different toxicities, we used liquid surface X-ray scattering and Langmuir trough insertion assays to compare Aβm, FO, and NFO surface activities and interactions with anionic DMPG lipid monolayers at the air/water interface. All Aβ species were highly surface active and rapidly adopted β-sheet rich structures upon adsorption to the air/water interface. Likewise, all Aβ species had affinity for the anionic membrane. Aβm rapidly converted to β-sheet rich assemblies upon binding the membrane, and these aggregated structures of Aβm and FO disrupted hexagonally packed lipid domains and resulted in membrane thinning and instability. In contrast, NFO perturbed membrane structure by extracting lipids from the air/water interface and causing macroscale membrane deformations. Altogether, our results support two models for membrane-mediated Aβ toxicity: fibril-induced reorganization of lipid packing and NFO-induced membrane destabilization and lipid extraction. This work provides a structural understanding of Aβ neurotoxicity via membrane interactions and aids the effort in understanding early events in Alzheimer's disease and other neurodegenerative diseases.
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Affiliation(s)
- Crystal M Vander Zanden
- Center for Biomedical Engineering , University of New Mexico , Albuquerque , New Mexico 87131 , United States
- Department of Chemical and Biological Engineering , University of New Mexico , Albuquerque , New Mexico 87131 , United States
- Department of Chemistry and Biochemistry , University of Colorado Colorado Springs , Colorado Springs , Colorado 80918 , United States
| | - Lois Wampler
- Department of Biomedical Engineering , Texas A&M University , College Station , Texas 77843 , United States
| | - Isabella Bowers
- Department of Engineering and Technology , Southeast Missouri State University , Cape Girardeau , Missouri 63701 , United States
| | - Erik B Watkins
- MPA-11: Materials Synthesis and Integrated Devices , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Jaroslaw Majewski
- Department of Chemical and Biological Engineering , University of New Mexico , Albuquerque , New Mexico 87131 , United States
- Division of Molecular and Cellular Biosciences , National Science Foundation , Alexandria , Virginia 22314 , United States
- Theoretical Biology and Biophysics , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Eva Y Chi
- Center for Biomedical Engineering , University of New Mexico , Albuquerque , New Mexico 87131 , United States
- Department of Chemical and Biological Engineering , University of New Mexico , Albuquerque , New Mexico 87131 , United States
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19
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Grasso G, Leanza L, Morbiducci U, Danani A, Deriu MA. Aminoacid substitutions in the glycine zipper affect the conformational stability of amyloid beta fibrils. J Biomol Struct Dyn 2019; 38:3908-3915. [PMID: 31543007 DOI: 10.1080/07391102.2019.1671224] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The aggregation of amyloid-beta peptides is associated with the pathogenesis of Alzheimer's disease. The hydrophobic core of the amyloid beta sequence contains a GxxxG repeated motif, called glycine zipper, which involves crucial residues for assuring stability and promoting the process of fibril formation. Mutations in this motif lead to a completely different oligomerization pathway and rate of fibril formation. In this work, we have tested G33L and G37L residue substitutions by molecular dynamics simulations. We found that both protein mutations may lead to remarkable changes in the fibril conformational stability. Results suggest the disruption of the glycine zipper as a possible strategy to reduce the aggregation propensity of amyloid beta peptides. On the basis of our data, further investigations may consider this key region as a binding site to design/discover novel effective inhibitors.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Gianvito Grasso
- Dalle Molle Institute for Artificial Intelligence (IDSIA), University of Applied Sciences of Southern Switzerland (SUPSI), University of Italian Switzerland (USI), Manno, Switzerland
| | - Luigi Leanza
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Italy
| | - Umberto Morbiducci
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Italy
| | - Andrea Danani
- Dalle Molle Institute for Artificial Intelligence (IDSIA), University of Applied Sciences of Southern Switzerland (SUPSI), University of Italian Switzerland (USI), Manno, Switzerland
| | - Marco A Deriu
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Italy
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20
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Arispe N, De Maio A. Memory Loss and the Onset of Alzheimer's Disease Could Be Under the Control of Extracellular Heat Shock Proteins. J Alzheimers Dis 2019; 63:927-934. [PMID: 29689729 DOI: 10.3233/jad-180161] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Alzheimer's disease (AD) is a major contemporary and escalating malady in which amyloid-β (Aβ) peptides are the most likely causative agent. Aβ peptides spontaneously tend to aggregate in extracellular fluids following a progression from a monomeric state, through intermediate forms, ending in amyloid fibers and plaques. It is generally accepted now that the neurotoxic agents leading to cellular death, memory loss, and other AD characteristics are the Aβ intermediate aggregated states. However, Aβ peptides are continuously produced, released into the extracellular space, and rapidly cleared from healthy brains. Coincidentally, members of the heat shock proteins (hsp) family are present in the extracellular medium of healthy cells and body fluids, opening the possibility that hsps and Aβ could meet and interact in the extracellular milieu of the brain. In this perspective and reflection article, we place our investigation showing that the presence of Hsp70s mitigate the formation of low molecular weight Aβ peptide oligomers resulting in a reduction of cellular toxicity, in context of the current understanding of the disease. We propose that it may be an inverse relationship between the presence of Hsp70, the stage of Aβ oligomers, neurotoxicity, and the incidence of AD, particularly since the expression and circulating levels of hsp decrease with aging. Combining these observations, we propose that changes in the dynamics of Hsp70s and Aβ concentrations in the circulating brain fluids during aging defines the control of the formation of Aβ toxic aggregates, thus determining the conditions for neuron degeneration and the incidence of AD.
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Affiliation(s)
- Nelson Arispe
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Antonio De Maio
- Department of Surgery and Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, USA
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21
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Wang X, Zheng W. Ca 2+ homeostasis dysregulation in Alzheimer's disease: a focus on plasma membrane and cell organelles. FASEB J 2019; 33:6697-6712. [PMID: 30848934 DOI: 10.1096/fj.201801751r] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Emerging evidence indicates that Ca2+ is a vital factor in modulating the pathogenesis of Alzheimer's disease (AD). In healthy neurons, Ca2+ concentration is balanced to maintain a lower level in the cytosol than in the extracellular space or certain intracellular compartments such as endoplasmic reticulum (ER) and the lysosome, whereas this homeostasis is broken in AD. On the plasma membrane, the AD hallmarks amyloid-β (Aβ) and tau interact with ligand-gated or voltage-gated Ca2+-influx channels and inhibit the Ca2+-efflux ATPase or exchangers, leading to an elevated intracellular Ca2+ level and disrupted Ca2+ signal. In the ER, the disabled presenilin "Ca2+ leak" function and the direct implications of Aβ and presenilin mutants contribute to Ca2+-signal disorder. The enhanced ryanodine receptor (RyR)-mediated and inositol 1,4,5-trisphosphate receptor (IP3R)-mediated Ca2+ release from the ER aggravates cytosolic Ca2+ disorder and triggers apoptosis; the down-regulated ER Ca2+ sensor, stromal interaction molecule (STIM), alleviates store-operated Ca2+ entry in plasma membrane, leading to spine loss. The increased transfer of Ca2+ from ER to mitochondria through mitochondria-associated ER membrane (MAM) causes Ca2+ overload in the mitochondrial matrix and consequently opens the cellular damage-related channel, mitochondrial permeability transition pore (mPTP). In this review, we discuss the effects of Aβ, tau and presenilin on neuronal Ca2+ signal, focusing on the receptors and regulators in plasma membrane and ER; we briefly introduce the involvement of MAM-mediated Ca2+ transfer and mPTP opening in AD pathogenesis.-Wang, X., Zheng, W. Ca2+ homeostasis dysregulation in Alzheimer's disease: a focus on plasma membrane and cell organelles.
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Affiliation(s)
- Xingjian Wang
- Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Wei Zheng
- Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang, China
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22
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Zhang M, Peyear T, Patmanidis I, Greathouse DV, Marrink SJ, Andersen OS, Ingólfsson HI. Fluorinated Alcohols' Effects on Lipid Bilayer Properties. Biophys J 2018; 115:679-689. [PMID: 30077334 PMCID: PMC6104562 DOI: 10.1016/j.bpj.2018.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 06/23/2018] [Accepted: 07/02/2018] [Indexed: 12/21/2022] Open
Abstract
Fluorinated alcohols (fluoroalcohols) have physicochemical properties that make them excellent solvents of peptides, proteins, and other compounds. Like other alcohols, fluoroalcohols also alter membrane protein function and lipid bilayer properties and stability. Thus, the questions arise: how potent are fluoroalcohols as lipid-bilayer-perturbing compounds, could small residual amounts that remain after adding compounds dissolved in fluoroalcohols alter lipid bilayer properties sufficiently to affect membranes and membrane protein function, and do they behave like other alcohols? To address these questions, we used a gramicidin-based fluorescence assay to determine the bilayer-modifying potency of selected fluoroalcohols: trifluoroethanol (TFE), HFIP, and perfluoro-tert-butanol (PFTB). These fluoroalcohols alter bilayer properties in the low (PFTB) to high (TFE) mM range. Using the same assay, we determined the bilayer partitioning of the alcohols. When referenced to the aqueous concentrations, the fluoroalcohols are more bilayer perturbing than their nonfluorinated counterparts, with the largest fluoroalcohol, PFTB, being the most potent and the smallest, TFE, the least. When referenced to the mole fractions in the membrane, however, the fluoroalcohols have equal or lesser bilayer-perturbing potency than their nonfluorinated counterparts, with TFE being more bilayer perturbing than PFTB. We compared the fluoroalcohols' molecular level bilayer interactions using atomistic molecular dynamics simulations and showed how, at higher concentrations, they can cause bilayer breakdown using absorbance measurements and 31P nuclear magnetic resonance.
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Affiliation(s)
- Mike Zhang
- Department Physiology and Biophysics, Weill Cornell Medicine, New York City, New York; The Bronx High School of Science, New York City, New York
| | - Thasin Peyear
- Department Physiology and Biophysics, Weill Cornell Medicine, New York City, New York
| | - Ilias Patmanidis
- Groningen Biomolecular Science and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands
| | - Denise V Greathouse
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas
| | - Siewert J Marrink
- Groningen Biomolecular Science and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands
| | - Olaf S Andersen
- Department Physiology and Biophysics, Weill Cornell Medicine, New York City, New York.
| | - Helgi I Ingólfsson
- Department Physiology and Biophysics, Weill Cornell Medicine, New York City, New York; Groningen Biomolecular Science and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands; Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California.
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23
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Rivera I, Capone R, Cauvi DM, Arispe N, De Maio A. Modulation of Alzheimer's amyloid β peptide oligomerization and toxicity by extracellular Hsp70. Cell Stress Chaperones 2018; 23:269-279. [PMID: 28956268 PMCID: PMC5823807 DOI: 10.1007/s12192-017-0839-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 01/20/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder leading to dementia caused by advanced neuronal dysfunction and death. The most significant symptoms of AD are observed at late stages of the disease when interventions are most likely too late to ameliorate the condition. Currently, the predominant theory for AD is the "amyloid hypothesis," which states that abnormally increased levels of amyloid β (Aβ) peptides result in the production of a variety of aggregates that are neurotoxic. The specific mechanisms for Aβ peptide-induced cytotoxicity have not yet been completely elucidated. However, since the majority of Aβ is released into the extracellular milieu, it is reasonable to assume that toxicity begins outside the cells and makes its way inside where it disrupts the basic cellular process resulting in cell death. There is increasing evidence that hsp, particularly Hsp70, are exported into the extracellular milieu by an active export mechanism independent of cell death. Therefore, both Aβ peptides and Hsp70 may coexist in a common environment during pathological conditions. We observed that Hsp70 affected the Aβ assembling process in vitro preventing oligomer formation. Moreover, the presence of Hsp70 reduced the Aβ peptide-induced toxicity of cultured neurons (N2A cells). These results suggest a potential mechanism for the reduction of the detrimental effects of Aβ peptides in AD.
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Affiliation(s)
- Isabel Rivera
- Division of Trauma, Critical Care, Burns and Acute Care Surgery, Department of Surgery and Department of Neurosciences, School of Medicine, University of California San Diego, 9500 Gilman Drive, #0739, La Jolla, 92093-0739, CA, USA
- Initiative for Maximizing Student Development (IMSD) Program, University of California San Diego, La Jolla, CA, USA
| | - Ricardo Capone
- Division of Trauma, Critical Care, Burns and Acute Care Surgery, Department of Surgery and Department of Neurosciences, School of Medicine, University of California San Diego, 9500 Gilman Drive, #0739, La Jolla, 92093-0739, CA, USA
| | - David M Cauvi
- Division of Trauma, Critical Care, Burns and Acute Care Surgery, Department of Surgery and Department of Neurosciences, School of Medicine, University of California San Diego, 9500 Gilman Drive, #0739, La Jolla, 92093-0739, CA, USA
| | - Nelson Arispe
- Department of Anatomy, Physiology and Genetics, Uniformed Services University School of Medicine, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA
| | - Antonio De Maio
- Division of Trauma, Critical Care, Burns and Acute Care Surgery, Department of Surgery and Department of Neurosciences, School of Medicine, University of California San Diego, 9500 Gilman Drive, #0739, La Jolla, 92093-0739, CA, USA.
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24
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Liu Y, Ren B, Zhang Y, Sun Y, Chang Y, Liang G, Xu L, Zheng J. Molecular simulation aspects of amyloid peptides at membrane interface. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1906-1916. [PMID: 29421626 DOI: 10.1016/j.bbamem.2018.02.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/31/2018] [Accepted: 02/01/2018] [Indexed: 12/13/2022]
Abstract
The interactions of amyloid peptides with cell membranes play an important role in maintaining the integrity and functionality of cell membrane. A thorough molecular-level understanding of the structure, dynamics, and interactions between amyloid peptides and cell membranes is critical to amyloid aggregation and toxicity mechanisms for the bench-to-bedside applications. Here we review the most recent computational studies of amyloid peptides at model cell membranes. Different mechanisms of action of amyloid peptides on/in cell membranes, targeted by different computational techniques at different lengthscales and timescales, are rationally discussed. Finally, we have proposed some new insights into the remaining challenges and perspectives for future studies to improve our understanding of the activity of amyloid peptides associated with protein-misfolding diseases. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
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Affiliation(s)
- Yonglan Liu
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, College of Life Science and Chemistry, Hunan University of Technology, Zhuzhou 412007, PR China; Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, United States
| | - Baiping Ren
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, United States
| | - Yanxian Zhang
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, United States
| | - Yan Sun
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Yung Chang
- R&D Center for Membrane Technology and Department of Chemical EngineeringChung Yuan Christian University, Chung-Li, Taoyuan 320, Taiwan
| | - Guizhao Liang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044, PR China
| | - Lijian Xu
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, College of Life Science and Chemistry, Hunan University of Technology, Zhuzhou 412007, PR China; Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, United States.
| | - Jie Zheng
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, United States.
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25
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D'Amato AR, Bramson MTK, Puhl DL, Johnson J, Corr DT, Gilbert RJ. Solvent retention in electrospun fibers affects scaffold mechanical properties. ELECTROSPINNING 2018; 2:15-28. [PMID: 31032427 PMCID: PMC6482971 DOI: 10.1515/esp-2018-0002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Electrospinning is a robust material fabrication method allowing for fine control of mechanical, chemical, and functional properties in scaffold manufacturing. Electrospun fiber scaffolds have gained prominence for their potential in a variety of applications such as tissue engineering and textile manufacturing, yet none have assessed the impact of solvent retention in fibers on the scaffold's mechanical properties. In this study, we hypothesized that retained electrospinning solvent acts as a plasticizer, and gradual solvent evaporation, by storing fibers in ambient air, will cause significant increases in electrospun fiber scaffold brittleness and stiffness, and a significant decrease in scaffold toughness. Thermogravimetric analysis indicated solvent retention in PGA, PLCL, and PET fibers, and not in PU and PCL fibers. Differential scanning calorimetry revealed that polymers that were electrospun below their glass transition temperature (T g ) retained solvent and polymers electrospun above T g did not. Young's moduli increased and yield strain decreased for solventretaining PGA, PLCL, and PET fiber scaffolds as solvent evaporated from the scaffolds over a period of 14 days. Toughness and failure strain decreased for PGA and PET scaffolds as solvent evaporated. No significant differences were observed in the mechanical properties of PU and PCL scaffolds that did not retain solvent. These observations highlight the need to consider solvent retention following electrospinning and its potential effects on scaffold mechanical properties.
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Affiliation(s)
- Anthony R D'Amato
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th St., Troy, New York 12180, United States of America; Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, 1623 15th Street, Troy, New York 12180, United States of America
| | - Michael T K Bramson
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th St., Troy, New York 12180, United States pf America
| | - Devan L Puhl
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th St., Troy, New York 12180, United States of America; Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, 1623 15th Street, Troy, New York 12180, United States of America
| | - Jed Johnson
- Nanofiber Solutions, 4389 Weaver Court North, Hilliard, OH 43026, United States of America
| | - David T Corr
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th St., Troy, New York 12180, United States pf America
| | - Ryan J Gilbert
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, 110 8th St., Troy, New York 12180, United States of America; Center for Biotechnology and Interdisciplinary Sciences, Rensselaer Polytechnic Institute, 1623 15th Street, Troy, New York 12180, United States of America
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26
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Kim AC, Lim S, Kim YK. Metal Ion Effects on Aβ and Tau Aggregation. Int J Mol Sci 2018; 19:E128. [PMID: 29301328 PMCID: PMC5796077 DOI: 10.3390/ijms19010128] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/24/2017] [Accepted: 12/28/2017] [Indexed: 01/13/2023] Open
Abstract
Amyloid and tau aggregation are implicated in manifold neurodegenerative diseases and serve as two signature pathological hallmarks in Alzheimer's disease (AD). Though aging is considered as a prominent risk factor for AD pathogenesis, substantial evidence suggests that an imbalance of essential biometal ions in the body and exposure to certain metal ions in the environment can potentially induce alterations to AD pathology. Despite their physiological importance in various intracellular processes, biometal ions, when present in excessive or deficient amounts, can serve as a mediating factor for neurotoxicity. Recent studies have also demonstrated the contribution of metal ions found in the environment on mediating AD pathogenesis. In this regard, the neuropathological features associated with biometal ion dyshomeostasis and environmental metal ion exposure have prompted widespread interest by multiple research groups. In this review, we discuss and elaborate on findings from previous studies detailing the possible role of both endogenous and exogenous metal ions specifically on amyloid and tau pathology in AD.
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Affiliation(s)
- Anne Claire Kim
- Department of Neuroscience, Wellesley College, Wellesley, MA 02481, USA.
- Brain Science Institute, Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.
| | - Sungsu Lim
- Brain Science Institute, Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.
| | - Yun Kyung Kim
- Brain Science Institute, Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.
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27
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Nageeb El-Helaly S, Abd Elbary A, Kassem MA, El-Nabarawi MA. Electrosteric stealth Rivastigmine loaded liposomes for brain targeting: preparation, characterization, ex vivo, bio-distribution and in vivo pharmacokinetic studies. Drug Deliv 2017; 24:692-700. [PMID: 28415883 PMCID: PMC8240971 DOI: 10.1080/10717544.2017.1309476] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/13/2017] [Accepted: 03/17/2017] [Indexed: 12/20/2022] Open
Abstract
Being one of the highly effective drugs in treatment of Alzheimer's disease, Rivastigmine brain targeting is highly demandable, therefore liposomal dispersion of Rivastigmine was prepared containing 2 mol% PEG-DSPE added to Lecithin, Didecyldimethyl ammonium bromide (DDAB), Tween 80 in 1:0.02:0.25 molar ratio. A major challenge during the preparation of liposomes is maintaining a stable formulation, therefore the aim of our study was to increase liposomal stability by addition of DDAB to give an electrostatic stability and PEG-DSPE to increase stability by steric hindrance, yielding what we called an electrosteric stealth (ESS) liposomes. A medium nano-sized liposome (478 ± 4.94 nm) with a nearly neutral zeta potential (ZP, -8 ± 0.2 mV) and an entrapment efficiency percentage of 48 ± 6.22 was prepared. Stability studies showed no major alteration after three months storage period concerning particle size, polydispersity index, ZP, entrapment efficiency and in vitro release study confirming the successful formation of a stable liposomes. No histopathological alteration was recorded for ESS liposomes of the sheep nasal mucosa. While ESS liposomes showed higher % of drug permeating through the sheep nasal mucosa (48.6%) than the drug solution (28.7%). On completing the in vivo pharmacokinetic studies of 36 rabbits showed 424.2% relative bioavailability of the mean plasma levels of the formula ESS compared to that of RHT intranasal solution and 486% relative bioavailability of the mean brain levels.
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Affiliation(s)
- Sara Nageeb El-Helaly
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Ahmed Abd Elbary
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Mohamed A. Kassem
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Mohamed A. El-Nabarawi
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
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28
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Pires RH, Saraiva MJ, Damas AM, Kellermayer MSZ. Force spectroscopy reveals the presence of structurally modified dimers in transthyretin amyloid annular oligomers. J Mol Recognit 2016; 30. [PMID: 27808434 DOI: 10.1002/jmr.2587] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 09/21/2016] [Accepted: 09/30/2016] [Indexed: 12/17/2022]
Abstract
Toxicity in amyloidogenic protein misfolding disorders is thought to involve intermediate states of aggregation associated with the formation of amyloid fibrils. Despite their relevance, the heterogeneity and transience of these oligomers have placed great barriers in our understanding of their structural properties. Among amyloid intermediates, annular oligomers or annular protofibrils have raised considerable interest because they may contribute to a mechanism of cellular toxicity via membrane permeation. Here we investigated, by using AFM force spectroscopy, the structural detail of amyloid annular oligomers from transthyretin (TTR), a protein involved in systemic and neurodegenerative amyloidogenic disorders. Manipulation was performed in situ, in the absence of molecular handles and using persistence length-fit values to select relevant curves. Force curves reveal the presence of dimers in TTR annular oligomers that unfold via a series of structural intermediates. This is in contrast with the manipulation of native TTR that was more often manipulated over length scales compatible with a TTR monomer and without unfolding intermediates. Imaging and force spectroscopy data suggest that dimers are formed by the assembly of monomers in a head-to-head orientation with a nonnative interface along their β-strands. Furthermore, these dimers stack through nonnative contacts that may enhance the stability of the misfolded structure.
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Affiliation(s)
- Ricardo H Pires
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary.,Institute for Molecular and Cell Biology (IBMC), Porto, Portugal
| | - Maria J Saraiva
- Institute for Molecular and Cell Biology (IBMC), Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Ana M Damas
- Institute for Molecular and Cell Biology (IBMC), Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Miklós S Z Kellermayer
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary.,MTA-SE Molecular Biophysics Research Group, Budapest, Hungary
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29
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Gillman AL, Lee J, Ramachandran S, Capone R, Gonzalez T, Wrasidlo W, Masliah E, Lal R. Small molecule NPT-440-1 inhibits ionic flux through Aβ 1-42 pores: Implications for Alzheimer's disease therapeutics. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2016; 12:2331-2340. [PMID: 27335341 PMCID: PMC5116404 DOI: 10.1016/j.nano.2016.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 05/31/2016] [Accepted: 06/04/2016] [Indexed: 12/11/2022]
Abstract
Increased levels of soluble amyloid-beta (Aβ) oligomers are suspected to underlie Alzheimer's disease (AD) pathophysiology. These oligomers have been shown to form multi-subunit Aβ pores in bilayers and induce uncontrolled, neurotoxic, ion flux, particularly calcium ions, across cellular membranes that might underlie cognitive impairment in AD. Small molecule interventions that modulate pore activity could effectively prevent or ameliorate their toxic activity. Here we examined the efficacy of a small molecule, NPT-440-1, on modulating amyloid pore permeability. Co-incubation of B103 rat neuronal cells with NPT-440-1 and Aβ1-42 prevented calcium influx. In purified lipid bilayers, we show that a 10-15min preincubation, prior to membrane introduction, was required to prevent conductance. Thioflavin-T and circular dichroism both suggested a reduction in Aβ1-42 β-sheet content during this incubation period. Combined with previous studies on site-specific amino acid substitutions, these results suggest that pharmacological modulation of Aβ1-42 could prevent amyloid pore-mediated AD pathogenesis.
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Affiliation(s)
- Alan L Gillman
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States
| | - Joon Lee
- Department of Mechanical and Aerospace Engineering University of California, San Diego, La Jolla, CA, United States
| | - Srinivasan Ramachandran
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States; Department of Mechanical and Aerospace Engineering University of California, San Diego, La Jolla, CA, United States
| | - Ricardo Capone
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States
| | - Tania Gonzalez
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States
| | - Wolf Wrasidlo
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States; Neuropore Therapies, Inc., San Diego, CA, United States
| | - Eliezer Masliah
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States.
| | - Ratnesh Lal
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States; Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA, United States; Department of Mechanical and Aerospace Engineering University of California, San Diego, La Jolla, CA, United States.
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30
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Pithadia AS, Bhunia A, Sribalan R, Padmini V, Fierke CA, Ramamoorthy A. Influence of a curcumin derivative on hIAPP aggregation in the absence and presence of lipid membranes. Chem Commun (Camb) 2016; 52:942-5. [PMID: 26587568 DOI: 10.1039/c5cc07792c] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The deposition of aggregates of human islet amyloid polypeptide (hIAPP) has been correlated with the death of β-cells in type II diabetes mellitus. The actual molecular mechanism of cell death remains largely unknown; however, it has been postulated that the process of aggregation from monomeric hIAPP is closely involved. A possible cause of cellular toxicity may be through the disruption of structural integrity of the cell membrane by IAPP. Herein, a water-soluble curcumin derivative, CurDAc, is used to investigate the mitigation of hIAPP aggregation in the absence and presence of lipid membrane.
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Affiliation(s)
- Amit S Pithadia
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Anirban Bhunia
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA. and Department of Biophysics, Bose Institute, Kolkata 700 054, India
| | - Rajendran Sribalan
- Department of Organic Chemistry, School of Chemistry, Madurai Kamraj University, Madurai 21, India
| | - Vediappen Padmini
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA. and Biophysics Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Carol A Fierke
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA. and Biophysics Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ayyalusamy Ramamoorthy
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA. and Biophysics Program, University of Michigan, Ann Arbor, MI 48109, USA
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31
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Zhang X, Liu J, Huang L, Yang X, Petersen RB, Sun Y, Gong H, Zheng L, Huang K. How the imidazole ring modulates amyloid formation of islet amyloid polypeptide: A chemical modification study. Biochim Biophys Acta Gen Subj 2016; 1860:719-26. [DOI: 10.1016/j.bbagen.2016.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 12/18/2015] [Accepted: 01/13/2016] [Indexed: 11/25/2022]
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Pithadia A, Brender JR, Fierke CA, Ramamoorthy A. Inhibition of IAPP Aggregation and Toxicity by Natural Products and Derivatives. J Diabetes Res 2016; 2016:2046327. [PMID: 26649317 PMCID: PMC4662995 DOI: 10.1155/2016/2046327] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 04/15/2015] [Indexed: 01/10/2023] Open
Abstract
Fibrillar aggregates of human islet amyloid polypeptide, hIAPP, a pathological feature seen in some diabetes patients, are a likely causative agent for pancreatic beta-cell toxicity, leading to a transition from a state of insulin resistance to type II diabetes through the loss of insulin producing beta-cells by hIAPP induced toxicity. Because of the probable link between hIAPP and the development of type II diabetes, there has been strong interest in developing reagents to study the aggregation of hIAPP and possible therapeutics to block its toxic effects. Natural products are a class of compounds with interesting pharmacological properties against amyloids which have made them interesting targets to study hIAPP. Specifically, the ability of polyphenolic natural products, EGCG, curcumin, and resveratrol, to modulate the aggregation of hIAPP is discussed. Furthermore, we have outlined possible mechanistic discoveries of the interaction of these small molecules with the peptide and how they may mitigate toxicity associated with peptide aggregation. These abundantly found agents have been long used to combat diseases for many years and may serve as useful templates toward developing therapeutics against hIAPP aggregation and toxicity.
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Affiliation(s)
- Amit Pithadia
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Jeffrey R. Brender
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Carol A. Fierke
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
- *Ayyalusamy Ramamoorthy:
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33
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Hong L, Huang YJ, Yong WA. A Kinetic Model for Cell Damage Caused by Oligomer Formation. Biophys J 2015; 109:1338-46. [PMID: 26445435 DOI: 10.1016/j.bpj.2015.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 07/27/2015] [Accepted: 08/11/2015] [Indexed: 11/25/2022] Open
Abstract
It is well known that the formation of amyloid fiber may cause invertible damage to cells, although the underlying mechanism has not been fully understood. In this article, a microscopic model considering the detailed processes of amyloid formation and cell damage is constructed based on four simple assumptions, one of which is that cell damage is raised by oligomers rather than mature fibrils. By taking the maximum entropy principle, this microscopic model in the form of infinite mass-action equations together with two reaction-convection partial differential equations (PDEs) has been greatly coarse-grained into a macroscopic system consisting of only five ordinary differential equations (ODEs). With this simple model, the effects of primary nucleation, elongation, fragmentation, and protein and seeds concentration on amyloid formation and cell damage have been extensively explored and compared with experiments. We hope that our results will provide new insights into the quantitative linkage between amyloid formation and cell damage.
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Affiliation(s)
- Liu Hong
- Zhou Pei-Yuan Center for Applied Mathematics, Tsinghua University, Peking, P.R. China.
| | - Ya-Jing Huang
- Zhou Pei-Yuan Center for Applied Mathematics, Tsinghua University, Peking, P.R. China
| | - Wen-An Yong
- Zhou Pei-Yuan Center for Applied Mathematics, Tsinghua University, Peking, P.R. China
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34
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Borutaite V, Morkuniene R, Valincius G. Beta-amyloid oligomers: recent developments. Biomol Concepts 2015; 2:211-22. [PMID: 25962030 DOI: 10.1515/bmc.2011.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 05/09/2011] [Indexed: 01/01/2023] Open
Abstract
Recent studies point to a critical role of soluble β-amyloid oligomers in the pathogenesis of one of the most common neurodegenerative diseases, Alzheimer's disease (AD). Beta-amyloid peptides are cleavage products of a ubiquitously expressed protein, the amyloid precursor protein. Early studies suggested that accumulation of extracellular β-amyloid aggregates are the most toxic species causing synaptic dysfunction and neuronal loss in particular regions of the brain (neurobiological features underlying cognitive decline of the AD patients). In recent years, a shift of pardigm occurred, and now there is accumulating evidence that soluble oligomeric forms of the peptide are the most toxic to neuronal cells. In this review, we discuss recent findings on the toxic effects of amyloid-β oligomers, their physico-chemical properties and the possible pathways of their formation in vitro and in vivo.
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35
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Dworzak J, Renvoisé B, Habchi J, Yates EV, Combadière C, Knowles TP, Dobson CM, Blackstone C, Paulsen O, Murphy PM. Neuronal Cx3cr1 Deficiency Protects against Amyloid β-Induced Neurotoxicity. PLoS One 2015; 10:e0127730. [PMID: 26038823 PMCID: PMC4454597 DOI: 10.1371/journal.pone.0127730] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 04/20/2015] [Indexed: 01/06/2023] Open
Abstract
Cx3cr1, the receptor for the chemokine Cx3cl1 (fractalkine), has been implicated in the progression and severity of Alzheimer's disease-like pathology in mice, but the underlying mechanisms remain unclear. A complicating factor is that Cx3cr1 has been demonstrated in both neurons and microglia. Here, we have dissected the differences between neuronal and microglial Cx3cr1, specifically by comparing direct amyloid-β-induced toxicity in cultured, mature, microglia-depleted hippocampal neurons from wild-type and Cx3cr1-/- mice. Wild-type neurons expressed both Cx3cl1 and Cx3cr1 and released Cx3cl1 in response to amyloid-β. Knockout of neuronal Cx3cr1 abated amyloid-β-induced lactate dehydrogenase release. Furthermore, amyloid-β differentially induced depression of pre- and postsynaptic components of miniature excitatory postsynaptic currents, in a peptide conformation-dependent manner. Knockout of neuronal Cx3cr1 abated effects of both amyloid-β conformational states, which were differentiable by aggregation kinetics and peptide morphology. We obtained similar results after both acute and chronic treatment of cultured neurons with the Cx3cr1 antagonist F1. Thus, neuronal Cx3cr1 may impact Alzheimer's disease-like pathology by modulating conformational state-dependent amyloid-β-induced synaptotoxicity.
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Affiliation(s)
- Jenny Dworzak
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Maryland, United States of America
- Neuronal Oscillations Group, Department of Physiology, Development, and Neuroscience, University of Cambridge, Cambridge, United Kingdom
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Benoît Renvoisé
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Johnny Habchi
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Emma V. Yates
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Christophe Combadière
- Centre d'Immunologie et des Maladies Infectieuses-Paris, Institut National de la Santé et de la Recherche Médicale, Paris, France
| | - Tuomas P. Knowles
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | | | - Craig Blackstone
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ole Paulsen
- Neuronal Oscillations Group, Department of Physiology, Development, and Neuroscience, University of Cambridge, Cambridge, United Kingdom
- * E-mail: (PMM); (OP)
| | - Philip M. Murphy
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (PMM); (OP)
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36
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Roberts HL, Brown DR. Seeking a mechanism for the toxicity of oligomeric α-synuclein. Biomolecules 2015; 5:282-305. [PMID: 25816357 PMCID: PMC4496673 DOI: 10.3390/biom5020282] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 03/08/2015] [Accepted: 03/11/2015] [Indexed: 12/31/2022] Open
Abstract
In a number of neurological diseases including Parkinson’s disease (PD), α‑synuclein is aberrantly folded, forming abnormal oligomers, and amyloid fibrils within nerve cells. Strong evidence exists for the toxicity of increased production and aggregation of α-synuclein in vivo. The toxicity of α-synuclein is popularly attributed to the formation of “toxic oligomers”: a heterogenous and poorly characterized group of conformers that may share common molecular features. This review presents the available evidence on the properties of α-synuclein oligomers and the potential molecular mechanisms of their cellular disruption. Toxic α-synuclein oligomers may impact cells in a number of ways, including the disruption of membranes, mitochondrial depolarization, cytoskeleton changes, impairment of protein clearance pathways, and enhanced oxidative stress. We also examine the relationship between α-synuclein toxic oligomers and amyloid fibrils, in the light of recent studies that paint a more complex picture of α-synuclein toxicity. Finally, methods of studying and manipulating oligomers within cells are described.
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Affiliation(s)
- Hazel L Roberts
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
| | - David R Brown
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
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37
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Morkuniene R, Cizas P, Jankeviciute S, Petrolis R, Arandarcikaite O, Krisciukaitis A, Borutaite V. Small Aβ1-42 oligomer-induced membrane depolarization of neuronal and microglial cells: role of N-methyl-D-aspartate receptors. J Neurosci Res 2014; 93:475-86. [PMID: 25400096 DOI: 10.1002/jnr.23510] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 10/01/2014] [Accepted: 10/02/2014] [Indexed: 11/08/2022]
Abstract
Although it is well documented that soluble beta amyloid (Aβ) oligomers are critical factors in the pathogenesis of Alzheimer's disease (AD) by causing synaptic dysfunction and neuronal death, the primary mechanisms by which Aβ oligomers trigger neurodegeneration are not entirely understood. We sought to investigate whether toxic small Aβ(1-42) oligomers induce changes in plasma membrane potential of cultured neurons and glial cells in rat cerebellar granule cell cultures leading to neuronal death and whether these effects are sensitive to the N-methyl-D-aspartate receptor (NMDA-R) antagonist MK801. We found that small Aβ(1-42) oligomers induced rapid, protracted membrane depolarization of both neurons and microglia, whereas there was no change in membrane potential of astrocytes. MK801 did not modulate Aβ-induced neuronal depolarization. In contrast, Aβ1(-42) oligomer-induced decrease in plasma membrane potential of microglia was prevented by MK801. Small Aβ(1-42) oligomers significantly elevated extracellular glutamate and caused neuronal necrosis, and both were prevented by MK801. Also, small Aβ(1-42) oligomers decreased resistance of isolated brain mitochondria to calcium-induced opening of mitochondrial permeability transition pore. In conclusion, the results suggest that the primary effect of toxic small Aβ oligomers on neurons is rapid, NMDA-R-independent plasma membrane depolarization, which leads to neuronal death. Aβ oligomers-induced depolarization of microglial cells is NMDA-R dependent.
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Affiliation(s)
- Ramune Morkuniene
- Institute of Neurosciences, Lithuanian University of Health Sciences, Kaunas, Lithuania
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38
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Zhang M, Zhao J, Zheng J. Molecular understanding of a potential functional link between antimicrobial and amyloid peptides. SOFT MATTER 2014; 10:7425-7451. [PMID: 25105988 DOI: 10.1039/c4sm00907j] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Antimicrobial and amyloid peptides do not share common sequences, typical secondary structures, or normal biological activity but both the classes of peptides exhibit membrane-disruption ability to induce cell toxicity. Different membrane-disruption mechanisms have been proposed for antimicrobial and amyloid peptides, individually, some of which are not exclusive to either peptide type, implying that certain common principles may govern the folding and functions of different cytolytic peptides and associated membrane disruption mechanisms. Particularly, some antimicrobial and amyloid peptides have been identified to have dual complementary amyloid and antimicrobial properties, suggesting a potential functional link between amyloid and antimicrobial peptides. Given that some similar structural and membrane-disruption characteristics exist between the two classes of peptides, this review summarizes major findings, recent advances, and future challenges related to antimicrobial and amyloid peptides and strives to illustrate the similarities, differences, and relationships in the sequences, structures, and membrane interaction modes between amyloid and antimicrobial peptides, with a special focus on direct interactions of the peptides with the membranes. We hope that this review will stimulate further research at the interface of antimicrobial and amyloid peptides - which has been studied less intensively than either type of peptides - to decipher a possible link between both amyloid pathology and antimicrobial activity, which can guide drug design and peptide engineering to influence peptide-membrane interactions important in human health and diseases.
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Affiliation(s)
- Mingzhen Zhang
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, USA.
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39
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The effects of organic solvents on the membrane-induced fibrillation of human islet amyloid polypeptide and on the inhibition of the fibrillation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:3162-70. [PMID: 25218343 DOI: 10.1016/j.bbamem.2014.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 09/02/2014] [Accepted: 09/03/2014] [Indexed: 11/23/2022]
Abstract
The organic solvent dimethylsulphoxide (DMSO) and 1,1,1,3,3,3-hexafluoro-2-isopropanol (HFIP) have been widely used as a pre-treating agent of amyloid peptides and as a vehicle for water-insoluble inhibitors. These solvents are left in many cases as a trace quantity in bulk and membrane environments with treated amyloid peptides or inhibitors. In the present work, we studied the effects of the two organic solvents on the aggregation behaviors of human islet amyloid polypeptide (hIAPP) and the performances of an all-D-amino-acid inhibitor D-NFGAIL in preventing hIAPP fibrillation both in bulk solution and at phospholipid membrane. We showed that the presence of 1% v/v DMSO or HFIP decreases the rate of fibril formation of hIAPP at the lipid membrane rather than accelerates the fibril formation as what happened in bulk solution. We also showed that the presence of 1% v/v DMSO or HFIP impairs the activity of the inhibitor at the lipid membrane surface dramatically, while it affects the efficiency of the inhibitor in bulk solution slightly. We found that the inhibitor inserts into the lipid membrane more deeply or with more proportion in the presence of the organic solvents than it does in the absence of the organic solvents, which may hinder the binding of the inhibitor to hIAPP at the lipid membrane. Our results suggest that the organic solvents should be used with caution in studying membrane-induced fibrillogenesis of amyloid peptides and in testing amyloid inhibitors under membrane environments to avoid incorrect evaluation to the fibrillation process of amyloid peptides and the activity of inhibitors.
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40
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Gillman AL, Jang H, Lee J, Ramachandran S, Kagan B, Nussinov R, Teran Arce F. Activity and architecture of pyroglutamate-modified amyloid-β (AβpE3-42) pores. J Phys Chem B 2014; 118:7335-44. [PMID: 24922585 PMCID: PMC4096221 DOI: 10.1021/jp5040954] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 06/10/2014] [Indexed: 12/17/2022]
Abstract
Among the family of Aβ peptides, pyroglutamate-modified Aβ (AβpE) peptides are particularly associated with cytotoxicity in Alzheimer's disease (AD). They represent the dominant fraction of Aβ oligomers in the brains of AD patients, but their accumulation in the brains of elderly individuals with normal cognition is significantly lower. Accumulation of AβpE plaques precedes the formation of plaques of full-length Aβ (Aβ1-40/42). Most of these properties appear to be associated with the higher hydrophobicity of AβpE as well as an increased resistance to enzymatic degradation. However, the important question of whether AβpE peptides induce pore activity in lipid membranes and their potential toxicity compared with other Aβ pores is still open. Here we examine the activity of AβpE pores in anionic membranes using planar bilayer electrical recording and provide their structures using molecular dynamics simulations. We find that AβpE pores spontaneously induce ionic current across the membrane and have some similar properties to the other previously studied pores of the Aβ family. However, there are also some significant differences. The onset of AβpE3-42 pore activity is generally delayed compared with Aβ1-42 pores. However, once formed, AβpE3-42 pores produce increased ion permeability of the membrane, as indicated by a greater occurrence of higher conductance electrical events. Structurally, the lactam ring of AβpE peptides induces a change in the conformation of the N-terminal strands of the AβpE3-42 pores. While the N-termini of wild-type Aβ1-42 peptides normally reside in the bulk water region, the N-termini of AβpE3-42 peptides tend to reside in the hydrophobic lipid core. These studies provide a first step to an understanding of the enhanced toxicity attributed to AβpE peptides.
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Affiliation(s)
- Alan L. Gillman
- Department
of Bioengineering, University of California,
San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
| | - Hyunbum Jang
- Cancer
and Inflammation Program, National Cancer Institute at Frederick,
Leidos Biomedical Research, Inc., Frederick
National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Joon Lee
- Department
of Mechanical and Aerospace Engineering and Material Science Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Srinivasan Ramachandran
- Department
of Bioengineering, University of California,
San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
- Department
of Mechanical and Aerospace Engineering and Material Science Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Bruce
L. Kagan
- Department
of Psychiatry, David Geffen School of Medicine, Semel Institute for
Neuroscience and Human Behavior, University
of California, 760 Westwood
Plaza, Los Angeles, California 90024, United States
| | - Ruth Nussinov
- Cancer
and Inflammation Program, National Cancer Institute at Frederick,
Leidos Biomedical Research, Inc., Frederick
National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
- Department
of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Fernando Teran Arce
- Department
of Bioengineering, University of California,
San Diego, 9500 Gilman
Drive, La Jolla, California 92093, United States
- Department
of Mechanical and Aerospace Engineering and Material Science Program, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
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41
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Johnson RD, Steel DG, Gafni A. Structural evolution and membrane interactions of Alzheimer's amyloid-beta peptide oligomers: new knowledge from single-molecule fluorescence studies. Protein Sci 2014; 23:869-83. [PMID: 24753305 DOI: 10.1002/pro.2479] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 04/15/2014] [Accepted: 04/17/2014] [Indexed: 02/05/2023]
Abstract
Amyloid-β peptide (Aβ) oligomers may represent the proximal neurotoxin in Alzheimer's disease. Single-molecule microscopy (SMM) techniques have recently emerged as a method for overcoming the innate difficulties of working with amyloid-β, including the peptide's low endogenous concentrations, the dynamic nature of its oligomeric states, and its heterogeneous and complex membrane interactions. SMM techniques have revealed that small oligomers of the peptide bind to model membranes and cells at low nanomolar-to-picomolar concentrations and diffuse at rates dependent on the membrane characteristics. These methods have also shown that oligomers grow or dissociate based on the presence of specific inhibitors or promoters and on the ratio of Aβ40 to Aβ42. Here, we discuss several types of single-molecule imaging that have been applied to the study of Aβ oligomers and their membrane interactions. We also summarize some of the recent insights SMM has provided into oligomer behavior in solution, on planar lipid membranes, and on living cell membranes. A brief overview of the current limitations of the technique, including the lack of sensitive assays for Aβ-induced toxicity, is included in hopes of inspiring future development in this area of research.
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Affiliation(s)
- Robin D Johnson
- Department of Biophysics, The University of Michigan, Ann Arbor, Michigan, 48109; University of Michigan Medical School, The University of Michigan, Ann Arbor, Michigan, 48105
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42
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Mason TO, Chirgadze DY, Levin A, Adler-Abramovich L, Gazit E, Knowles TPJ, Buell AK. Expanding the solvent chemical space for self-assembly of dipeptide nanostructures. ACS NANO 2014; 8:1243-53. [PMID: 24422499 DOI: 10.1021/nn404237f] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Nanostructures composed of short, noncyclic peptides represent a growing field of research in nanotechnology due to their ease of production, often remarkable material properties, and biocompatibility. Such structures have so far been almost exclusively obtained through self-assembly from aqueous solution, and their morphologies are determined by the interactions between building blocks as well as interactions between building blocks and water. Using the diphenylalanine system, we demonstrate here that, in order to achieve structural and morphological control, a change in the solvent environment represents a simple and convenient alternative strategy to the chemical modification of the building blocks. Diphenylalanine (FF) is a dipeptide capable of self-assembly in aqueous solution into needle-like hollow micro- and nanocrystals with continuous nanoscale channels that possess advantageous properties such as high stiffness and piezoelectricity and have so emerged as attractive candidates for functional nanomaterials. We investigate systematically the solubility of diphenylalanine in a range of organic solvents and probe the role of the solvent in the kinetics of self-assembly and the structures of the final materials. Finally, we report the crystal structure of the FF peptide in microcrystalline form grown from MeOH solution at 1 Å resolution and discuss the structural changes relative to the conventional materials self-assembled in aqueous solution. These findings provide a significant expansion of the structures and morphologies that are accessible through FF self-assembly for existing and future nanotechnological applications of this peptide. Solvent mediation of molecular recognition and self-association processes represents an important route to the design of new supramolecular architectures deriving their functionality from the nanoscale ordering of their components.
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Affiliation(s)
- Thomas O Mason
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, United Kingdom, ‡Department of Biochemistry, University of Cambridge , 80 Tennis Court Road, CB2 1GA Cambridge, United Kingdom
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43
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Gheorghiu M, David S, Polonschii C, Olaru A, Gaspar S, Bajenaru O, Popescu BO, Gheorghiu E. Label free sensing platform for amyloid fibrils effect on living cells. Biosens Bioelectron 2014; 52:89-97. [DOI: 10.1016/j.bios.2013.08.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 08/17/2013] [Indexed: 01/19/2023]
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44
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Majd S, Yusko EC, Yang J, Sept D, Mayer M. A model for the interfacial kinetics of phospholipase D activity on long-chain lipids. Biophys J 2014; 105:146-53. [PMID: 23823233 DOI: 10.1016/j.bpj.2013.05.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 05/02/2013] [Accepted: 05/06/2013] [Indexed: 11/26/2022] Open
Abstract
The membrane-active enzyme phospholipase D (PLD) catalyzes the hydrolysis of the phosphodiester bond in phospholipids and plays a critical role in cell signaling. This catalytic reaction proceeds on lipid-water interfaces and is an example of heterogeneous catalysis in biology. Recently we showed that planar lipid bilayers, a previously unexplored model membrane for these kinetic studies, can be used for monitoring interfacial catalytic reactions under well-defined experimental conditions with chemical and electrical access to both sides of the lipid membrane. Employing an assay that relies on the conductance of the pore-forming peptide gramicidin A to monitor PLD activity, the work presented here reveals the kinetics of hydrolysis of long-chain phosphatidylcholine lipids in situ. We have developed an extension of a basic kinetic model for interfacial catalysis that includes product activation and substrate depletion. This model describes the kinetic behavior very well and reveals two kinetic parameters, the specificity constant and the interfacial quality constant. This approach results in a simple and general model to account for product accumulation in interfacial enzyme kinetics.
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Affiliation(s)
- Sheereen Majd
- Department of Bioengineering, Pennsylvania State University, University Park, Pennsylvania, USA.
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45
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Mayer M, Yang J. Engineered ion channels as emerging tools for chemical biology. Acc Chem Res 2013; 46:2998-3008. [PMID: 23932142 DOI: 10.1021/ar400129t] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Over the last 25 years, researchers have developed exogenously expressed, genetically engineered, semi-synthetic, and entirely synthetic ion channels. These structures have sufficient fidelity to serve as unique tools that can reveal information about living organisms. One of the most exciting success stories is optogenetics: the use of light-gated channels to trigger action potentials in specific neurons combined with studies of the response from networks of cells or entire live animals. Despite this breakthrough, the use of molecularly engineered ion channels for studies of biological systems is still in its infancy. Historically, researchers studied ion channels in the context of their own function in single cells or in multicellular signaling and regulation. Only recently have researchers considered ion channels and pore-forming peptides as responsive tools to report on the chemical and physical changes produced by other biochemical processes and reactions. This emerging class of molecular probes has a number of useful characteristics. For instance, these structures can greatly amplify the signal of chemical changes: the binding of one molecule to a ligand-gated ion channel can result in flux of millions of ions across a cell membrane. In addition, gating occurs on sub-microsecond time scales, resulting in fast response times. Moreover, the signal is complementary to existing techniques because the output is ionic current rather than fluorescence or radioactivity. And finally, ion channels are also localized at the membrane of cells where essential processes such as signaling and regulation take place. This Account highlights examples, mostly from our own work, of uses of ion channels and pore-forming peptides such as gramicidin in chemical biology. We discuss various strategies for preparing synthetically tailored ion channels that range from de novo designed synthetic molecules to genetically engineered or simply exogenously expressed or reconstituted wild-type channels. Next we consider aspects of experimental design by comparing various membrane environments or systems that make it possible to quantify the response of ion channels to biochemical processes of interest. We present applications of ion channels to answer questions in chemical biology, and propose potential future developments and applications of these single molecule probes. Finally we discuss the hurdles that impede the routine use of ion channel probes in biochemistry and cell biology laboratories and developments and strategies that could overcome these problems. Optogenetics has facilitated breakthroughs in neuroscience, and these results give a dramatic idea of what may lie ahead for designed ion channels as a functional class of molecular probes. If researchers can improve molecular engineering to increase ion channel versatility and can overcome the barriers to collaborating across disciplines, we conclude that these structures could have tremendous potential as novel tools for chemical biology studies.
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Affiliation(s)
- Michael Mayer
- Department of Chemical Engineering and Department of Biomedical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109-2110, United States
| | - Jerry Yang
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California 92093-0358, United States
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46
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Jensen LE, Bultynck G, Luyten T, Amijee H, Bootman MD, Roderick HL. Alzheimer's disease-associated peptide Aβ42 mobilizes ER Ca(2+) via InsP3R-dependent and -independent mechanisms. Front Mol Neurosci 2013; 6:36. [PMID: 24204331 PMCID: PMC3817845 DOI: 10.3389/fnmol.2013.00036] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Accepted: 10/14/2013] [Indexed: 11/13/2022] Open
Abstract
Dysregulation of Ca2+ homeostasis is considered to contribute to the toxic action of the Alzheimer's disease (AD)-associated amyloid-β-peptide (Aβ). Ca2+ fluxes across the plasma membrane and release from intracellular stores have both been reported to underlie the Ca2+ fluxes induced by Aβ42. Here, we investigated the contribution of Ca2+ release from the endoplasmic reticulum (ER) to the effects of Aβ42 upon Ca2+ homeostasis and the mechanism by which Aβ42 elicited these effects. Consistent with previous reports, application of soluble oligomeric forms of Aβ42 induced an elevation in intracellular Ca2+. The Aβ42-stimulated Ca2+ signals persisted in the absence of extracellular Ca2+ indicating a significant contribution of Ca2+ release from the ER Ca2+ store to the generation of these signals. Moreover, inositol 1,4,5-trisphosphate (InsP3) signaling contributed to Aβ42-stimulated Ca2+ release. The Ca2+ mobilizing effect of Aβ42 was also observed when applied to permeabilized cells deficient in InsP3 receptors, revealing an additional direct effect of Aβ42 upon the ER, and a mechanism for induction of toxicity by intracellular Aβ42.
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Affiliation(s)
- Laura E Jensen
- Babraham Institute, Babraham Research Campus Babraham, Cambridge, UK
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47
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Sepúlveda FJ, Fierro H, Fernandez E, Castillo C, Peoples RW, Opazo C, Aguayo LG. Nature of the neurotoxic membrane actions of amyloid-β on hippocampal neurons in Alzheimer's disease. Neurobiol Aging 2013; 35:472-81. [PMID: 24112789 DOI: 10.1016/j.neurobiolaging.2013.08.035] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 08/26/2013] [Accepted: 08/30/2013] [Indexed: 10/26/2022]
Abstract
The mechanism by which amyloid-β (Aβ) produces brain dysfunction in patients with Alzheimer's disease is largely unknown. According to previous studies, Aβ might share perforating properties with gramicidin, a well-accepted membrane-disrupting peptide. Therefore, we hypothesize that the key steps leading to synaptotoxicity by Aβ and gramicidin involve peptide aggregation, pore formation, and calcium dysregulation. Here, we show that Aβ and gramicidin form aggregates enriched in β-sheet structures using electron microscopy, and Thioflavin and Congo Red staining techniques. Also, we found that Aβ and gramicidin display fairly similar actions in hippocampal cell membranes, i.e. inducing Ca(2+) entry and synaptoxicity characterized by the loss of synaptic proteins and a decrease in neuronal viability. These effects were not observed in a Ca(2+) free solution, indicating that both Aβ and gramicidin induce neurotoxicity by a Ca(2+)-dependent mechanism. Using combined perforated patch clamp and imaging recordings, we found that only Aβ produced a perforation that progressed from a small (Cl(-)-selective pore) to a larger perforation that allowed the entry of fluorescent molecules. Therefore, based on these results, we propose that the perforation at the plasma membrane by Aβ is a dynamic process that is critical in producing neurotoxicity similar to that found in the brains of AD patients.
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Affiliation(s)
- Fernando J Sepúlveda
- Laboratory of Neurophysiology, Department of Physiology, University of Concepción, Concepción, Chile
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48
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Lemkul JA, Bevan DR. Aggregation of Alzheimer’s Amyloid β-Peptide in Biological Membranes: A Molecular Dynamics Study. Biochemistry 2013; 52:4971-80. [DOI: 10.1021/bi400562x] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Justin A. Lemkul
- Department of Biochemistry, Virginia Polytechnic Institute
and State University, Blacksburg, Virginia 24061, United States
| | - David R. Bevan
- Department of Biochemistry, Virginia Polytechnic Institute
and State University, Blacksburg, Virginia 24061, United States
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49
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Jang H, Connelly L, Arce FT, Ramachandran S, Lal R, Kagan BL, Nussinov R. Alzheimer's disease: which type of amyloid-preventing drug agents to employ? Phys Chem Chem Phys 2013; 15:8868-77. [PMID: 23450150 PMCID: PMC3663909 DOI: 10.1039/c3cp00017f] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The current paradigm in the amyloid hypothesis brands small β-amyloid (Aβ) oligomers as the toxic species in Alzheimer's disease (AD). These oligomers are fibril-like; contain β-sheet structure, and present exposed hydrophobic surface. Oligomers with this motif are capable of penetrating the cell membrane, gathering to form toxic ion channels. Current agents suppressing precursor Aβ cleavage have only met partial success; and to date, those targeting the peptides and their assemblies in the aqueous environment of the extracellular space largely fail in clinical trials. One possible reason is failure to reach membrane-embedded targets of disease-'infected' cells. Here we provide an overview, point to the need to account for the lipid environment when aiming to prevent the formation of toxic channels, and propose a combination therapy to target the species spectrum.
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Affiliation(s)
- Hyunbum Jang
- Center for Cancer Research, Nanobiology Program, Basic Science Program, SAIC-Frederick, Inc., National Cancer Institute, Frederick, Maryland 21702, USA
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50
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Ryan TM, Caine J, Mertens HDT, Kirby N, Nigro J, Breheney K, Waddington LJ, Streltsov VA, Curtain C, Masters CL, Roberts BR. Ammonium hydroxide treatment of Aβ produces an aggregate free solution suitable for biophysical and cell culture characterization. PeerJ 2013; 1:e73. [PMID: 23678397 PMCID: PMC3646356 DOI: 10.7717/peerj.73] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 04/22/2013] [Indexed: 11/20/2022] Open
Abstract
Alzheimer's disease is the leading cause of dementia in the elderly. Pathologically it is characterized by the presence of amyloid plaques and neuronal loss within the brain tissue of affected individuals. It is now widely hypothesised that fibrillar structures represent an inert structure. Biophysical and toxicity assays attempting to characterize the formation of both the fibrillar and the intermediate oligomeric structures of Aβ typically involves preparing samples which are largely monomeric; the most common method by which this is achieved is to use the fluorinated organic solvent 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). Recent evidence has suggested that this method is not 100% effective in producing an aggregate free solution. We show, using dynamic light scattering, size exclusion chromatography and small angle X-ray scattering that this is indeed the case, with HFIP pretreated Aβ peptide solutions displaying an increased proportion of oligomeric and aggregated material and an increased propensity to aggregate. Furthermore we show that an alternative technique, involving treatment with strong alkali results in a much more homogenous solution that is largely monomeric. These techniques for solubilising and controlling the oligomeric state of Aβ are valuable starting points for future biophysical and toxicity assays.
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Affiliation(s)
- Timothy M Ryan
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne , Parkville, Victoria , Australia
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