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Gasbarri C, Angelini G. Cyclocurcumin as Promising Bioactive Natural Compound: An Overview. Molecules 2024; 29:1451. [PMID: 38611731 PMCID: PMC11013289 DOI: 10.3390/molecules29071451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 03/11/2024] [Accepted: 03/22/2024] [Indexed: 04/14/2024] Open
Abstract
Although identical in molecular formula and weight, curcumin and cyclocurcumin show remarkable differences in their reactivity. Both are natural compounds isolated from the rhizome of turmeric, the former is involved in the diketo/keto-enol tautomerism through the bis-α,β-unsaturated diketone unit according to the polarity of the solvent, while the latter could react by trans-cis isomerization due to the presence of the α,β-unsaturated dihydropyranone moiety. Even if curcumin is generally considered responsible of the therapeutical properties of Curcuma longa L. due to its high content, cyclocurcumin has attracted great interest over the last several decades for its individual behavior and specific features as a bioactive compound. Cyclocurcumin has a hydrophobic nature characterized by fluorescence emission, solvatochromism, and the tendency to form spherical fluorescent aggregates in aqueous solution. Molecular docking analysis reveals the potentiality of cyclocurcumin as antioxidant, enzyme inhibitor, and antiviral agent. Promising biological activities are observed especially in the treatment of degenerative and cardiovascular diseases. Despite the versatility emerging from the data reported herein, the use of cyclocurcumin seems to remain limited in clinical applications mainly because of its low solubility and bioavailability.
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Affiliation(s)
- Carla Gasbarri
- Department of Pharmacy, University “G. d’Annunzio” of Chieti—Pescara, Via dei Vestini, 66100 Chieti, Italy;
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2
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Kaur S, Sehrawat A, Mastana SS, Kandimalla R, Sharma PK, Bhatti GK, Bhatti JS. Targeting calcium homeostasis and impaired inter-organelle crosstalk as a potential therapeutic approach in Parkinson's disease. Life Sci 2023; 330:121995. [PMID: 37541578 DOI: 10.1016/j.lfs.2023.121995] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 07/27/2023] [Accepted: 07/31/2023] [Indexed: 08/06/2023]
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta, leading to motor symptoms such as tremors, rigidity, and bradykinesia. Current therapeutic strategies for PD are limited and mainly involve symptomatic relief, with no available treatment for the underlying causes of the disease. Therefore, there is a need for new therapeutic approaches that target the underlying pathophysiological mechanisms of PD. Calcium homeostasis is an essential process for maintaining proper cellular function and survival, including neuronal cells. Calcium dysregulation is also observed in various organelles, including the endoplasmic reticulum (ER), mitochondria, and lysosomes, resulting in organelle dysfunction and impaired inter-organelle communication. The ER, as the primary calcium reservoir, is responsible for folding proteins and maintaining calcium homeostasis, and its dysregulation can lead to protein misfolding and neurodegeneration. The crosstalk between ER and mitochondrial calcium signaling is disrupted in PD, leading to neuronal dysfunction and death. In addition, a lethal network of calcium cytotoxicity utilizes mitochondria, ER and lysosome to destroy neurons. This review article focused on the complex role of calcium dysregulation and its role in aggravating functioning of organelles in PD so as to provide new insight into therapeutic strategies for treating this disease. Targeting dysfunctional organelles, such as the ER and mitochondria and lysosomes and whole network of calcium dyshomeostasis can restore proper calcium homeostasis and improve neuronal function. Additionally targeting calcium dyshomeostasis that arises from miscommunication between several organelles can be targeted so that therapeutic effects of calcium are realised in whole cellular territory.
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Affiliation(s)
- Satinder Kaur
- Laboratory of Translational Medicine and Nanotherapeutics, Department of Human Genetics and Molecular Medicine, School of Health Sciences, Central University of Punjab, Bathinda, India
| | - Abhishek Sehrawat
- Laboratory of Translational Medicine and Nanotherapeutics, Department of Human Genetics and Molecular Medicine, School of Health Sciences, Central University of Punjab, Bathinda, India
| | - Sarabjit Singh Mastana
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.
| | - Ramesh Kandimalla
- CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad, Telangana, India
| | | | - Gurjit Kaur Bhatti
- Department of Medical Lab Technology, University Institute of Applied Health Sciences, Chandigarh University, Mohali, India.
| | - Jasvinder Singh Bhatti
- Laboratory of Translational Medicine and Nanotherapeutics, Department of Human Genetics and Molecular Medicine, School of Health Sciences, Central University of Punjab, Bathinda, India.
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Viles JH. Imaging Amyloid-β Membrane Interactions: Ion-Channel Pores and Lipid-Bilayer Permeability in Alzheimer's Disease. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 135:e202215785. [PMID: 38515735 PMCID: PMC10952214 DOI: 10.1002/ange.202215785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Indexed: 03/08/2023]
Abstract
The accumulation of the amyloid-β peptides (Aβ) is central to the development of Alzheimer's disease. The mechanism by which Aβ triggers a cascade of events that leads to dementia is a topic of intense investigation. Aβ self-associates into a series of complex assemblies with different structural and biophysical properties. It is the interaction of these oligomeric, protofibril and fibrillar assemblies with lipid membranes, or with membrane receptors, that results in membrane permeability and loss of cellular homeostasis, a key event in Alzheimer's disease pathology. Aβ can have an array of impacts on lipid membranes, reports have included: a carpeting effect; a detergent effect; and Aβ ion-channel pore formation. Recent advances imaging these interactions are providing a clearer picture of Aβ induced membrane disruption. Understanding the relationship between different Aβ structures and membrane permeability will inform therapeutics targeting Aβ cytotoxicity.
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Affiliation(s)
- John H. Viles
- Department of Biochemistry, SBBS, Queen MaryUniversity of LondonUK
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4
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Viles JH. Imaging Amyloid-β Membrane Interactions: Ion-Channel Pores and Lipid-Bilayer Permeability in Alzheimer's Disease. Angew Chem Int Ed Engl 2023; 62:e202215785. [PMID: 36876912 PMCID: PMC10953358 DOI: 10.1002/anie.202215785] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 03/07/2023]
Abstract
The accumulation of the amyloid-β peptides (Aβ) is central to the development of Alzheimer's disease. The mechanism by which Aβ triggers a cascade of events that leads to dementia is a topic of intense investigation. Aβ self-associates into a series of complex assemblies with different structural and biophysical properties. It is the interaction of these oligomeric, protofibril and fibrillar assemblies with lipid membranes, or with membrane receptors, that results in membrane permeability and loss of cellular homeostasis, a key event in Alzheimer's disease pathology. Aβ can have an array of impacts on lipid membranes, reports have included: a carpeting effect; a detergent effect; and Aβ ion-channel pore formation. Recent advances imaging these interactions are providing a clearer picture of Aβ induced membrane disruption. Understanding the relationship between different Aβ structures and membrane permeability will inform therapeutics targeting Aβ cytotoxicity.
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Affiliation(s)
- John H. Viles
- Department of Biochemistry, SBBS, Queen MaryUniversity of LondonUK
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5
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The interactions of amyloid β aggregates with phospholipid membranes and the implications for neurodegeneration. Biochem Soc Trans 2023; 51:147-159. [PMID: 36629697 DOI: 10.1042/bst20220434] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/20/2022] [Accepted: 12/22/2022] [Indexed: 01/12/2023]
Abstract
Misfolding, aggregation and accumulation of Amyloid-β peptides (Aβ) in neuronal tissue and extracellular matrix are hallmark features of Alzheimer's disease (AD) pathology. Soluble Aβ oligomers are involved in neuronal toxicity by interacting with the lipid membrane, compromising its integrity, and affecting the function of receptors. These facts indicate that the interaction between Aβ oligomers and cell membranes may be one of the central molecular level factors responsible for the onset of neurodegeneration. The present review provides a structural understanding of Aβ neurotoxicity via membrane interactions and contributes to understanding early events in Alzheimer's disease.
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Yi Y, Lim MH. Current understanding of metal-dependent amyloid-β aggregation and toxicity. RSC Chem Biol 2023; 4:121-131. [PMID: 36794021 PMCID: PMC9906324 DOI: 10.1039/d2cb00208f] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/22/2022] [Indexed: 11/23/2022] Open
Abstract
The discovery of effective therapeutics targeting amyloid-β (Aβ) aggregates for Alzheimer's disease (AD) has been very challenging, which suggests its complicated etiology associated with multiple pathogenic elements. In AD-affected brains, highly concentrated metals, such as copper and zinc, are found in senile plaques mainly composed of Aβ aggregates. These metal ions are coordinated to Aβ and affect its aggregation and toxicity profiles. In this review, we illustrate the current view on molecular insights into the assembly of Aβ peptides in the absence and presence of metal ions as well as the effect of metal ions on their toxicity.
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Affiliation(s)
- Yelim Yi
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
| | - Mi Hee Lim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
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7
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Abstract
Perturbation of cell membranes by amyloid β (Ab) peptide oligomers is one possible mechanism of cytotoxicity in Alzheimer's disease, but the structure of such Ab-membrane complexes is unknown. Here we examine the stability of several putative structures by implicit membrane and all-atom molecular dynamics simulations. The structures include (a) a variety of models proposed by other researchers in the past, (b) a heptameric β barrel determined by grafting the Ab sequence onto α-hemolysin, (c) a similar structure with modified strand orientation and turn location based on an experimental β-hairpin structure, (d) oligomers inserting C-terminal β hairpins into one leaflet of the bilayer, (e) oligomers forming parallel C-terminal β barrels, and (f) a helical hexamer made of C-terminal fragments. The α-hemolysin-grafted structure and its alternately oriented variant are stable in the membrane and form an aqueous pore. In contrast, the C-terminal parallel barrels are not stable, presumably due to excessive hydrophobicity of their inner surface. The helical hexamer also failed to stabilize an aqueous pore for the same reason. The C-terminal hairpin-inserting structures remain stably inserted but, again, do not form an aqueous pore. Our results suggest that only β-barrels inserting a combination of C-terminal and other residues can form stable aqueous pores.
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Affiliation(s)
- Aliasghar Sepehri
- Department of Chemistry, City College of New York, CUNY, 160 Convent Avenue, New York, New York10031, United States
| | - Themis Lazaridis
- Department of Chemistry, City College of New York, CUNY, 160 Convent Avenue, New York, New York10031, United States.,Graduate Programs in Chemistry, Biochemistry, and Physics, The Graduate Center, City University of New York, 365 Fifth Avenue, New York, New York10016, United States
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8
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Taylor AP, Davis PJ, Aubrey LD, White JBR, Parton ZN, Staniforth RA. Simple, Reliable Protocol for High-Yield Solubilization of Seedless Amyloid-β Monomer. ACS Chem Neurosci 2022; 14:53-71. [PMID: 36512740 PMCID: PMC9817077 DOI: 10.1021/acschemneuro.2c00411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Self-assembly of the amyloid-β (Aβ) peptide to form toxic oligomers and fibrils is a key causal event in the onset of Alzheimer's disease, and Aβ is the focus of intense research in neuroscience, biophysics, and structural biology aimed at therapeutic development. Due to its rapid self-assembly and extreme sensitivity to aggregation conditions, preparation of seedless, reproducible Aβ solutions is highly challenging, and there are serious ongoing issues with consistency in the literature. In this paper, we use a liquid-phase separation technique, asymmetric flow field-flow fractionation with multiangle light scattering (AF4-MALS), to develop and validate a simple, effective, economical method for re-solubilization and quality control of purified, lyophilized Aβ samples. Our findings were obtained with recombinant peptide but are physicochemical in nature and thus highly relevant to synthetic peptide. We show that much of the variability in the literature stems from the inability of overly mild solvent treatments to produce consistently monomeric preparations and is rectified by a protocol involving high-pH (>12) dissolution, sonication, and rapid freezing to prevent modification. Aβ treated in this manner is chemically stable, can be stored over long timescales at -80 °C, and exhibits remarkably consistent self-assembly behavior when returned to near-neutral pH. These preparations are highly monomeric, seedless, and do not require additional rounds of size exclusion, eliminating the need for this costly procedure and increasing the flexibility of use. We propose that our improved protocol is the simplest, fastest, and most effective way to solubilize Aβ from diverse sources for sensitive self-assembly and toxicity assays.
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Taylor AIP, Staniforth RA. General Principles Underpinning Amyloid Structure. Front Neurosci 2022; 16:878869. [PMID: 35720732 PMCID: PMC9201691 DOI: 10.3389/fnins.2022.878869] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 05/11/2022] [Indexed: 12/14/2022] Open
Abstract
Amyloid fibrils are a pathologically and functionally relevant state of protein folding, which is generally accessible to polypeptide chains and differs fundamentally from the globular state in terms of molecular symmetry, long-range conformational order, and supramolecular scale. Although amyloid structures are challenging to study, recent developments in techniques such as cryo-EM, solid-state NMR, and AFM have led to an explosion of information about the molecular and supramolecular organization of these assemblies. With these rapid advances, it is now possible to assess the prevalence and significance of proposed general structural features in the context of a diverse body of high-resolution models, and develop a unified view of the principles that control amyloid formation and give rise to their unique properties. Here, we show that, despite system-specific differences, there is a remarkable degree of commonality in both the structural motifs that amyloids adopt and the underlying principles responsible for them. We argue that the inherent geometric differences between amyloids and globular proteins shift the balance of stabilizing forces, predisposing amyloids to distinct molecular interaction motifs with a particular tendency for massive, lattice-like networks of mutually supporting interactions. This general property unites previously characterized structural features such as steric and polar zippers, and contributes to the long-range molecular order that gives amyloids many of their unique properties. The shared features of amyloid structures support the existence of shared structure-activity principles that explain their self-assembly, function, and pathogenesis, and instill hope in efforts to develop broad-spectrum modifiers of amyloid function and pathology.
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Mrdenovic D, Pieta IS, Nowakowski R, Kutner W, Lipkowski J, Pieta P. Amyloid β interaction with model cell membranes - What are the toxicity-defining properties of amyloid β? Int J Biol Macromol 2022; 200:520-531. [PMID: 35074328 DOI: 10.1016/j.ijbiomac.2022.01.117] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/10/2022] [Accepted: 01/18/2022] [Indexed: 01/26/2023]
Abstract
Disruption of the neuronal membrane by toxic amyloid β oligomers is hypothesized to be the major event associated with Alzheimer's disease's neurotoxicity. Misfolding of amyloid β is followed by aggregation via different pathways in which structurally different amyloid β oligomers can be formed. The respective toxic actions of these structurally diverse oligomers can vary significantly. Linking a particular toxic action to a structurally unique kind of amyloid β oligomers and resolving their toxicity-determining feature remains challenging because of their transient stability and heterogeneity. Moreover, the lipids that make up the membrane affect amyloid β oligomers' behavior, thus adding to the problem's complexity. The present review compares and analyzes the latest results to improve understanding of amyloid β oligomers' interaction with lipid bilayers.
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Affiliation(s)
- Dusan Mrdenovic
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland; Department of Chemistry, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada
| | - Izabela S Pieta
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Robert Nowakowski
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Wlodzimierz Kutner
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland; Faculty of Mathematics and Natural Sciences, School of Sciences, Cardinal Stefan Wyszynski University in Warsaw, Wóycickiego 1/3, 01-815 Warsaw, Poland
| | - Jacek Lipkowski
- Department of Chemistry, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada
| | - Piotr Pieta
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
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Zaretsky DV, Zaretskaia MV, Molkov YI. Membrane channel hypothesis of lysosomal permeabilization by beta-amyloid. Neurosci Lett 2021; 770:136338. [PMID: 34767924 DOI: 10.1016/j.neulet.2021.136338] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/29/2021] [Accepted: 11/03/2021] [Indexed: 11/16/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia affecting millions of people. Neuronal death in AD is initiated by oligomeric amyloid-β (Aβ) peptides. Recently, we proposed the amyloid degradation toxicity hypothesis, which explains multiple major observations associated with AD including autophagy failure and a decreased metabolism. According to the hypothesis, the key event in the cellular toxicity of amyloid is the formation of non-selective membrane channels in lysosomal membranes by amyloid fragments that are produced by the digestion of Aβ previously absorbed by endocytosis. Electrophysiological data suggest that amyloid-formed channels have different sizes, which can be explained by the fact that channel creating barrel-shaped amyloid aggregates can consist of different number of monomers. To estimate the ability of channels to leak molecules of various molecular weights, we modeled the channels as saline-filled cylinders in non-conductive membranes that pass spheres with a density of average globular proteins. As a basis, we used the conductance distribution taken from the previously published experimental dataset, in which single channels with electrical conductance of up to one nanosiemens were registered. Our calculations show that channels with such a giant conductance can allow for passing macromolecules such as large as lysosomal cathepsins implicated in the activation of apoptosis. The formation of giant channels is disproportionally promoted in an acidic environment. Also, amyloid fragments leaking from permeabilized lysosomes can reach the internal leaflet of the plasma membrane and permeabilize it. We conclude that while dissipation of the proton gradient by any (even smallest) amyloid channels readily explains lysosomal failure, the relatively rare events of lysosomal permeabilization to large macromolecules can be an additional mechanism of cellular death induced by exposure to Aβ.
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Affiliation(s)
| | | | - Yaroslav I Molkov
- Department of Mathematics and Statistics and Neuroscience Institute, Georgia State University, Atlanta, GA 30303, United States
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Zaretsky DV, Zaretskaia MV. Intracellular ion changes induced by the exposure to beta-amyloid can be explained by the formation of channels in the lysosomal membranes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1869:119145. [PMID: 34606794 DOI: 10.1016/j.bbamcr.2021.119145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 08/29/2021] [Accepted: 09/05/2021] [Indexed: 10/20/2022]
Abstract
In this manuscript, we reassess the data on beta-amyloid-induced changes of intracellular ions concentrations published previously by Abramov et al. (2003, 2004). Their observations made using high-resolution confocal microscopy with fast temporal resolution of images formed by fluorescent ion-sensitive fluorescent probes in living cells represent an unequivocal support for the amyloid channel theory. However, closer look reveals multiple facts which cannot be explained by channel formation in plasma membrane. Recently proposed amyloid degradation toxicity hypothesis provides the interpretation to these facts by considering that channels are formed in the lysosomal membranes.
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Sciaccaluga M, Megaro A, Bellomo G, Ruffolo G, Romoli M, Palma E, Costa C. An Unbalanced Synaptic Transmission: Cause or Consequence of the Amyloid Oligomers Neurotoxicity? Int J Mol Sci 2021; 22:ijms22115991. [PMID: 34206089 PMCID: PMC8199544 DOI: 10.3390/ijms22115991] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 12/18/2022] Open
Abstract
Amyloid-β (Aβ) 1-40 and 1-42 peptides are key mediators of synaptic and cognitive dysfunction in Alzheimer's disease (AD). Whereas in AD, Aβ is found to act as a pro-epileptogenic factor even before plaque formation, amyloid pathology has been detected among patients with epilepsy with increased risk of developing AD. Among Aβ aggregated species, soluble oligomers are suggested to be responsible for most of Aβ's toxic effects. Aβ oligomers exert extracellular and intracellular toxicity through different mechanisms, including interaction with membrane receptors and the formation of ion-permeable channels in cellular membranes. These damages, linked to an unbalance between excitatory and inhibitory neurotransmission, often result in neuronal hyperexcitability and neural circuit dysfunction, which in turn increase Aβ deposition and facilitate neurodegeneration, resulting in an Aβ-driven vicious loop. In this review, we summarize the most representative literature on the effects that oligomeric Aβ induces on synaptic dysfunction and network disorganization.
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Affiliation(s)
- Miriam Sciaccaluga
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
- Correspondence: (M.S.); (C.C.); Tel.: +39-0755858180 (M.S.); +39-0755784233 (C.C.)
| | - Alfredo Megaro
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
| | - Giovanni Bellomo
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, Istituto Pasteur—Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (G.R.); (E.P.)
- IRCCS San Raffaele Pisana, 00166 Rome, Italy
| | - Michele Romoli
- Neurology Unit, Rimini “Infermi” Hospital—AUSL Romagna, 47923 Rimini, Italy;
| | - Eleonora Palma
- Department of Physiology and Pharmacology, Istituto Pasteur—Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (G.R.); (E.P.)
| | - Cinzia Costa
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
- Correspondence: (M.S.); (C.C.); Tel.: +39-0755858180 (M.S.); +39-0755784233 (C.C.)
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Elevating the Levels of Calcium Ions Exacerbate Alzheimer's Disease via Inducing the Production and Aggregation of β-Amyloid Protein and Phosphorylated Tau. Int J Mol Sci 2021; 22:ijms22115900. [PMID: 34072743 PMCID: PMC8198078 DOI: 10.3390/ijms22115900] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/08/2021] [Accepted: 05/08/2021] [Indexed: 01/03/2023] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease with a high incidence rate. The main pathological features of AD are β-amyloid plaques (APs), which are formed by β-amyloid protein (Aβ) deposition, and neurofibrillary tangles (NFTs), which are formed by the excessive phosphorylation of the tau protein. Although a series of studies have shown that the accumulation of metal ions, including calcium ions (Ca2+), can promote the formation of APs and NFTs, there is no systematic review of the mechanisms by which Ca2+ affects the development and progression of AD. In view of this, the current review summarizes the mechanisms by which Ca2+ is transported into and out of cells and organelles, such as the cell, endoplasmic reticulum, mitochondrial and lysosomal membranes to affect the balance of intracellular Ca2+ levels. In addition, dyshomeostasis of Ca2+ plays an important role in modulating the pathogenesis of AD by influencing the production and aggregation of Aβ peptides and tau protein phosphorylation and the ways that disrupting the metabolic balance of Ca2+ can affect the learning ability and memory of people with AD. In addition, the effects of these mechanisms on the synaptic plasticity are also discussed. Finally, the molecular network through which Ca2+ regulates the pathogenesis of AD is introduced, providing a theoretical basis for improving the clinical treatment of AD.
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Zaretsky DV, Zaretskaia MV. Mini-review: Amyloid degradation toxicity hypothesis of Alzheimer's disease. Neurosci Lett 2021; 756:135959. [PMID: 34000347 DOI: 10.1016/j.neulet.2021.135959] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 04/28/2021] [Accepted: 05/10/2021] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia affecting millions of people. Neuronal death in AD is initiated by oligomeric amyloid-β (Aβ) peptides. The amyloid channel hypothesis readily explains the primary molecular damage but does not address major observations associated with AD such as autophagy failure and decreased metabolism. The amyloid degradation toxicity hypothesis provides the interpretation as a sequence of molecular events. Aβ enters a cell by endocytosis, and the endocytic vesicle is merged with a lysosome. Lysosomal peptidases degrade the peptide. Fragments form membrane channels in lysosomal membranes that have a significant negative charge due to the presence of acidic phospholipids. Amyloid channels can transfer various ions (including protons) and even relatively large compounds, which explains lysosomal permeabilization. The neutralization of lysosomal content inactivates degradation enzymes, results in an accumulation of undigested amyloid, and stalls autophagy. Inadequate quality control of mitochondria is associated with an increased production of reactive oxygen species and decreased energy production. Also, the passage of lysosomal proteases through rare extremely large channels results in cell death. Proposed hypothesis identifies biochemical pathways involved in the initiation and progression of cellular damage induced by beta-amyloid and provides new potential pharmacological targets to treat Alzheimer's disease.
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Dogra A, Narang RS, Narang JK. Recent Advances in Nanotherapeutic Interventions for the Treatment of Alzheimer's Disease. Curr Pharm Des 2020; 26:2257-2279. [PMID: 32321393 DOI: 10.2174/1381612826666200422092620] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 03/06/2020] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD), with impairment of learning and memory as the common clinical manifestations, is one of the most challenging diseases affecting individuals, their families and society as a whole. The fact that its prevalence is escalating rapidly, with the total number of AD patients estimated to reach 115.4 million by 2050, has made the disease a very challenging ailment worldwide. Several biological barriers like the bloodbrain barrier (BBB), drug efflux by P-glycoprotein and the blood-cerebrospinal fluid barrier restrict the delivery of conventional AD drugs to the central nervous system (CNS), thereby limiting their effectiveness. In order to overcome the above physiological barriers, the development of nanomedicines has been extensively explored. The present review provides an insight into the pathophysiology of AD and risk factors associated with AD. Besides, various nanoformulations reported in the literature for the diagnosis and treatments of AD have been classified and summarised. The patented nanoformulations for AD and details of nanoformulations which are in clinical trials are also mentioned. The review would be helpful to researchers and scientific community by providing them with information related to the recent advances in nanointerventions for the diagnosis and treatment of AD, which they can further explore for better management of the disease. However, although the nanotherapeutics for managing AD have been extensively explored, the factors which hinder their commercialisation, the toxicity concern being one of them, need to be addressed so that effective nanotherapeutics for AD can be developed for clinical use.
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Affiliation(s)
- Anmol Dogra
- Department of Pharmaceutics, Khalsa College of Pharmacy, Amritsar, Punjab, India.,I.K. Gujral Punjab Technical University, Kapurthala, Punjab, India
| | - R S Narang
- Department of Oral & Maxillofacial Pathology and Microbiology, Sri Guru Ram Das Institute of Dental Sciences and Research, Amritsar, Punjab, India
| | - Jasjeet K Narang
- Department of Pharmaceutics, Khalsa College of Pharmacy, Amritsar, Punjab, India
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Zaretsky DV, Zaretskaia MV. Flow cytometry method to quantify the formation of beta-amyloid membrane ion channels. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183506. [PMID: 33171157 DOI: 10.1016/j.bbamem.2020.183506] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/31/2020] [Accepted: 11/05/2020] [Indexed: 11/17/2022]
Abstract
It is accepted that the cytotoxicity of beta-amyloid is mediated by its oligomers. Amyloid peptides can form ion channels in cell membranes and allow calcium and other ions to enter cells. In this project, we developed a technique to quantify the appearance of calcium in liposomes and applied this technique to study the effect of amyloid peptides on the permeability of membranes. Calcium influx was monitored in liposomes made of phosphatidylcholine (PC) or phosphatidylserine (PS) with an addition of a lipid-soluble dye DiD and containing fluorescent calcium-sensitive probe Fluo-3. The intensity of fluorescence of individual liposomes was measured using a flow cytometer. Calcium ionophore ionomycin served as a positive control. The addition of micromolar concentrations of short fragments of amyloid-beta (Aβ25-35) permeabilized a significant number of PS liposomes. This effect was not observed in PC liposomes. Our data supports the hypothesis that the ion channel formation by amyloid peptide is dependent on electrostatic interactions. High concentrations of Aβ25-35 (above 20 μM) increased signal intensity in a recording channel corresponding to the calcium-sensing probe. However, this phenomenon was also observed in Ca2+-free conditions and even in liposomes without Fluo-3, so we interpreted it as an artifact. Using the described technique, we were not able to detect the formation of calcium channels by several other amyloid peptides. Considering that liposomes appeared resistant to reasonable concentrations of solvents, we expect that described flowmetric technique can be used in high-throughput screening applications.
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Tetrapeptide Ac-HAEE-NH 2 Protects α4β2 nAChR from Inhibition by Aβ. Int J Mol Sci 2020; 21:ijms21176272. [PMID: 32872553 PMCID: PMC7504039 DOI: 10.3390/ijms21176272] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 12/25/2022] Open
Abstract
The cholinergic deficit in Alzheimer’s disease (AD) may arise from selective loss of cholinergic neurons caused by the binding of Aβ peptide to nicotinic acetylcholine receptors (nAChRs). Thus, compounds preventing such an interaction are needed to address the cholinergic dysfunction. Recent findings suggest that the 11EVHH14 site in Aβ peptide mediates its interaction with α4β2 nAChR. This site contains several charged amino acid residues, hence we hypothesized that the formation of Aβ-α4β2 nAChR complex is based on the interaction of 11EVHH14 with its charge-complementary counterpart in α4β2 nAChR. Indeed, we discovered a 35HAEE38 site in α4β2 nAChR, which is charge-complementary to 11EVHH14, and molecular modeling showed that a stable Aβ42-α4β2 nAChR complex could be formed via the 11EVHH14:35HAEE38 interface. Using surface plasmon resonance and bioinformatics approaches, we further showed that a corresponding tetrapeptide Ac-HAEE-NH2 can bind to Aβ via 11EVHH14 site. Finally, using two-electrode voltage clamp in Xenopus laevis oocytes, we showed that Ac-HAEE-NH2 tetrapeptide completely abolishes the Aβ42-induced inhibition of α4β2 nAChR. Thus, we suggest that 35HAEE38 is a potential binding site for Aβ on α4β2 nAChR and Ac-HAEE-NH2 tetrapeptide corresponding to this site is a potential therapeutic for the treatment of α4β2 nAChR-dependent cholinergic dysfunction in AD.
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Stoye NM, Dos Santos Guilherme M, Endres K. Alzheimer's disease in the gut-Major changes in the gut of 5xFAD model mice with ApoA1 as potential key player. FASEB J 2020; 34:11883-11899. [PMID: 32681583 DOI: 10.1096/fj.201903128rr] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 06/17/2020] [Accepted: 06/23/2020] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) affects around 33 million people worldwide, which makes it the most prominent form of dementia. The main focus of AD research has been on the central nervous system (CNS) for long, but in recent years, the gut gained more attention. The intestinal tract is innervated by the enteric nervous system (ENS), built of numerous different types of neurons showing great similarity to neurons of the CNS. It already has been demonstrated that the amyloid precursor protein, which plays a major role in AD pathology, is also expressed in these cells. We analyzed gut tissue of AD model mice (5xFAD) and the respective wild-type littermates at different pathological stages: pre-pathological, early pathological and late pathological. Our results show significant difference in function of the intestine of 5xFAD mice as compared to wild-type mice. Using a pathway array detecting 84 AD-related gene products, we found ApoA1 expression significantly altered in colon tissue of 5xFAD mice. Furthermore, we unveil ApoA1's beneficial impact on cell viability and calcium homeostasis of cultured enteric neurons of 5xFAD animals. With this study, we demonstrate that the intestine is altered in AD-like pathology and that ApoA1 might be one key player within the gut.
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Affiliation(s)
- Nicolai M Stoye
- Department of Psychiatry and Psychotherapy, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Malena Dos Santos Guilherme
- Department of Psychiatry and Psychotherapy, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Kristina Endres
- Department of Psychiatry and Psychotherapy, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
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20
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Fantini J, Chahinian H, Yahi N. Progress toward Alzheimer's disease treatment: Leveraging the Achilles' heel of Aβ oligomers? Protein Sci 2020; 29:1748-1759. [PMID: 32567070 DOI: 10.1002/pro.3906] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 06/17/2020] [Accepted: 06/19/2020] [Indexed: 12/14/2022]
Abstract
After three decades of false hopes and failures, a pipeline of therapeutic drugs that target the actual root cause of Alzheimer's disease (AD) is now available. Challenging the old paradigm that focused on β-amyloid peptide (Aβ) aggregation in amyloid plaques, these compounds are designed to prevent the neurotoxicity of Aβ oligomers that form Ca2+ permeable pores in the membranes of brain cells. By triggering an intracellular Ca2+ overdose, Aβ oligomers induce a cascade of neurotoxic events including oxidative stress, tau hyperphosphorylation, and neuronal loss. Targeting any post-Ca2+ entry steps (e.g., tau) will not address the root cause of the disease. Thus, preventing Aβ oligomers formation and/or blocking their toxicity is by essence the best approach to stop any progression of AD. Three categories of anti-oligomer compounds are already available: antibodies, synthetic peptides, and small drugs. Independent in silico-based designs of a peptide (AmyP53) and a monoclonal antibody (PMN310) converged to identify a histidine motif (H13/H14) that is critical for oligomer neutralization. This "histidine trick" can be viewed as the Achilles' heel of Aβ in the fight against AD. Moreover, lipid rafts and especially gangliosides play a critical role in the formation and toxicity of Aβ oligomers. Recognizing AD as a membrane disorder and gangliosides as the key anti-oligomer targets will provide innovative opportunities to find an efficient cure. A "full efficient" solution would also need to be affordable to anyone, as the number of patients has been following an exponential increase, affecting every part of the globe.
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Affiliation(s)
- Jacques Fantini
- INSERM UMR_S 1072, Aix-Marseille Université, Marseille, France
| | - Henri Chahinian
- INSERM UMR_S 1072, Aix-Marseille Université, Marseille, France
| | - Nouara Yahi
- INSERM UMR_S 1072, Aix-Marseille Université, Marseille, France
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21
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Karkisaval AG, Rostagno A, Azimov R, Ban DK, Ghiso J, Kagan BL, Lal R. Ion channel formation by N-terminally truncated Aβ (4-42): relevance for the pathogenesis of Alzheimer's disease. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2020; 29:102235. [PMID: 32531337 DOI: 10.1016/j.nano.2020.102235] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 11/17/2022]
Abstract
Aβ deposition is a pathological hallmark of Alzheimer's disease (AD). Besides the full-length amyloid forming peptides (Aβ1-40 and Aβ1-42), biochemical analyses of brain deposits have identified a variety of N- and C-terminally truncated Aβ variants in sporadic and familial AD patients. However, their relevance for AD pathogenesis remains largely understudied. We demonstrate that Aβ4-42 exhibits a high tendency to form β-sheet structures leading to fast self-aggregation and formation of oligomeric assemblies. Atomic force microscopy and electrophysiological studies reveal that Aβ4-42 forms highly stable ion channels in lipid membranes. These channels that are blocked by monoclonal antibodies specifically recognizing the N-terminus of Aβ4-42. An Aβ variant with a double truncation at phenylalanine-4 and leucine 34, (Aβ4-34), exhibits unstable channel formation capability. Taken together the results presented herein highlight the potential benefit of C-terminal proteolytic cleavage and further support an important pathogenic role for N-truncated Aβ species in AD pathophysiology.
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Affiliation(s)
- Abhijith G Karkisaval
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, 92092, USA
| | - Agueda Rostagno
- Department of Pathology, New York University Grossman School of Medicine, 550 First Avenue, New York, NY, 10016, USA
| | - Rustam Azimov
- Department of Psychiatry, Geffen School of Medicine, University of California, Los Angeles, California 90095, USA; Semel Neuropsychiatric for Neuroscience & Human Behavior, University of California, Los Angeles, California 90095, United States
| | - Deependra K Ban
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, 92092, USA
| | - Jorge Ghiso
- Department of Pathology, New York University Grossman School of Medicine, 550 First Avenue, New York, NY, 10016, USA; Department of Psychiatry, New York University Grossman School of Medicine, 550 First Avenue, New York, NY, 10016, USA.
| | - Bruce L Kagan
- Department of Psychiatry, Geffen School of Medicine, University of California, Los Angeles, California 90095, USA; Semel Neuropsychiatric for Neuroscience & Human Behavior, University of California, Los Angeles, California 90095, United States.
| | - Ratnesh Lal
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, 92092, USA; Department of Bioengineering, University of California San Diego, La Jolla, California, 92092, USA; Materials Science and Engineering, University of California San Diego, La Jolla, California, 92092, USA.
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22
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Kawahara M, Kato-Negishi M, Tanaka KI. Amyloids: Regulators of Metal Homeostasis in the Synapse. Molecules 2020; 25:molecules25061441. [PMID: 32210005 PMCID: PMC7145306 DOI: 10.3390/molecules25061441] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/17/2020] [Accepted: 03/20/2020] [Indexed: 12/11/2022] Open
Abstract
Conformational changes in amyloidogenic proteins, such as β-amyloid protein, prion proteins, and α-synuclein, play a critical role in the pathogenesis of numerous neurodegenerative diseases, including Alzheimer’s disease, prion disease, and Lewy body disease. The disease-associated proteins possess several common characteristics, including the ability to form amyloid oligomers with β-pleated sheet structure, as well as cytotoxicity, although they differ in amino acid sequence. Interestingly, these amyloidogenic proteins all possess the ability to bind trace metals, can regulate metal homeostasis, and are co-localized at the synapse, where metals are abundantly present. In this review, we discuss the physiological roles of these amyloidogenic proteins in metal homeostasis, and we propose hypothetical models of their pathogenetic role in the neurodegenerative process as the loss of normal metal regulatory functions of amyloidogenic proteins. Notably, these amyloidogenic proteins have the capacity to form Ca2+-permeable pores in membranes, suggestive of a toxic gain of function. Therefore, we focus on their potential role in the disruption of Ca2+ homeostasis in amyloid-associated neurodegenerative diseases.
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23
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Kepp KP, Squitti R. Copper imbalance in Alzheimer’s disease: Convergence of the chemistry and the clinic. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.06.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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24
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Mehra R, Kepp KP. Cell size effects in the molecular dynamics of the intrinsically disordered Aβ peptide. J Chem Phys 2019; 151:085101. [DOI: 10.1063/1.5115085] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Rukmankesh Mehra
- Technical University of Denmark, DTU Chemistry, Building 206, 2800 Kgs. Lyngby, Denmark
| | - Kasper P. Kepp
- Technical University of Denmark, DTU Chemistry, Building 206, 2800 Kgs. Lyngby, Denmark
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25
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Teng T, Ridgley DM, Tsoy A, Sun GY, Askarova S, Lee JC. Azelnidipine Attenuates the Oxidative and NFκB Pathways in Amyloid-β-Stimulated Cerebral Endothelial Cells. ACS Chem Neurosci 2019; 10:209-215. [PMID: 30399318 DOI: 10.1021/acschemneuro.8b00368] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cerebral amyloid angiopathy (CAA), a condition depicting cerebrovascular accumulation of amyloid β-peptide (Aβ), is a common pathological manifestation in Alzheimer's disease (AD). In this study, we investigated the effects of Azelnidipine (ALP), a dihydropyridine calcium channel blocker known for its treatment of hypertension, on oligomeric Aβ (oAβ)-induced calcium influx and its downstream pathway in immortalized mouse cerebral endothelial cells (bEND3). We found that ALP attenuated oAβ-induced calcium influx, superoxide anion production, and phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and calcium-dependent cytosolic phospholipase A2 (cPLA2). Both ALP and cPLA2 inhibitor, methylarachidonyl fluorophosphate (MAFP), suppressed oAβ-induced translocation of NFκB p65 subunit to nuclei, suggesting that cPLA2 activation and calcium influx are essential for oAβ-induced NFκB activation. In sum, our results suggest that calcium channel blocker could be a potential therapeutic strategy for suppressing oxidative stress and inflammatory responses in Aβ-stimulated microvasculature in AD.
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Affiliation(s)
- Tao Teng
- Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan Street, MC 063, Chicago, Illinois 60607, United States
| | - Devin M. Ridgley
- Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan Street, MC 063, Chicago, Illinois 60607, United States
| | - Andrey Tsoy
- National Laboratory Astana, Nazarbayev University, Astana, Kazakhstan 010000
| | - Grace Y. Sun
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Sholpan Askarova
- National Laboratory Astana, Nazarbayev University, Astana, Kazakhstan 010000
| | - James C. Lee
- Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan Street, MC 063, Chicago, Illinois 60607, United States
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26
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W. Pilkington IV A, Legleiter J. Challenges in understanding the structure/activity relationship of Aβ oligomers. AIMS BIOPHYSICS 2019. [DOI: 10.3934/biophy.2019.1.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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27
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28
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Zolghadr AR, Heydari Dokoohaki M. How Does the P7C3-Series of Neuroprotective Small Molecules Prevent Membrane Disruption? J Chem Inf Model 2017; 57:2009-2019. [PMID: 28691805 DOI: 10.1021/acs.jcim.7b00151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Molecular dynamics (MD) simulations are conducted to suggest a mechanism of action for the aminopropyl dibromocarbazole derivative (P7C3) small molecule, which protects neurons from apoptotic cell death. At first, the influence of embedded Aβ42 stacks on the structure of membrane is studied. Then, the effect of P7C3 molecules on the Aβ42 fibril enriched membrane and Aβ42 fibril depleted membrane (when Aβ42 fibrils are originally dissolved in the aqueous phase) are evaluated. Also, the formation of an amyloid ion channel in the Aβ42 enriched membrane is examined by calculating deuterium order parameter, density profile, and surface thickness. For Aβ42 in the fully inserted state, ion channel-like structures are formed. The presence of P7C3 molecules in this case just postpones membrane destruction but could not prevent pore formation. In contrast, when both Aβ42 and P7C3 molecules are embedded in the aqueous solution, the P7C3 molecules are self-assembled at membrane/ionic aqueous solution interface and prevent the precipitation and deposition of Aβ42 fibrils into the membrane.
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29
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Voelker MJ, Barz B, Urbanc B. Fully Atomistic Aβ40 and Aβ42 Oligomers in Water: Observation of Porelike Conformations. J Chem Theory Comput 2017; 13:4567-4583. [DOI: 10.1021/acs.jctc.7b00495] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Matthew J. Voelker
- Department
of Physics, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Bogdan Barz
- Institute
of Complex Systems, Structural Biochemistry ICS-6: Structural Biochemistry, Forschungzentrum Jülich GmbH, Jülich 52425, Germany
- Institute
of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany
| | - Brigita Urbanc
- Department
of Physics, Drexel University, Philadelphia, Pennsylvania 19104, United States
- Faculty
of Mathematics and Physics, University of Ljubljana, Ljubljana 1000, Slovenia
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30
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Randino R, Grimaldi M, Persico M, De Santis A, Cini E, Cabri W, Riva A, D’Errico G, Fattorusso C, D’Ursi AM, Rodriquez M. Investigating the Neuroprotective Effects of Turmeric Extract: Structural Interactions of β-Amyloid Peptide with Single Curcuminoids. Sci Rep 2016; 6:38846. [PMID: 28004737 PMCID: PMC5177957 DOI: 10.1038/srep38846] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 11/15/2016] [Indexed: 02/04/2023] Open
Abstract
A broad biophysical analysis was performed to investigate the molecular basis of the neuroprotective action of Curcuma longa extracts in Alzheimer's disease. By combining circular dichroism and electron paramagnetic resonance experiments with molecular modeling calculations, the minor components of Curcuma longa extracts, such as demethoxycurcumin (2, DMC), bisdemethoxycurcumin (3, BDMC) and cyclocurcumin (4, CYC), were analyzed in a membrane environment mimicking the phospholipid bilayer. Our study provides the first evidence on the relative role of single curcuminoids interacting with Aβ-peptide. When the CYC and curcumin metabolite tetrahydrocurcumin (5, THC) were inserted into an anionic lipid solution, a significant modification of the Aβ CD curves was detected. These data were implemented by EPR experiments, demonstrating that CYC reaches the inner part of the bilayer, while the other curcuminoids are localized close to the membrane interface. Computational studies provided a model for the curcuminoid-Aβ interaction, highlighting the importance of a constrained "semi-folded" conformation to interact with Aβ analogously to the pattern observed in α-helical coiled-coil peptide structures. This combined approach led to a better understanding of the intriguing in vitro and in vivo activity of curcuminoids as anti-Alzheimer agents, paving a new path for the rational design of optimized druggable analogues.
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Affiliation(s)
- Rosario Randino
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, 84084-Fisciano-Italy
| | - Manuela Grimaldi
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, 84084-Fisciano-Italy
| | - Marco Persico
- Department of Pharmacy, University of Naples “Federico II”, Via D. Montesano, 49, 80131-Naples-Italy
| | - Augusta De Santis
- Department of Chemical Sciences, University of Naples “Federico II”, Via Cinthia, 80126-Naples-Italy
| | - Elena Cini
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro, 2, 53100-Siena-Italy
| | - Walter Cabri
- R&D Department, Indena, Viale Ortles, 12, 20139-Milan-Italy
- Innovation & Development Fresenius-Kabi, Piazza Maestri del Lavoro, 7, 20063-Cernusco sul Naviglio Milan-Italy
| | - Antonella Riva
- R&D Department, Indena, Viale Ortles, 12, 20139-Milan-Italy
| | - Gerardino D’Errico
- Department of Chemical Sciences, University of Naples “Federico II”, Via Cinthia, 80126-Naples-Italy
| | - Caterina Fattorusso
- Department of Pharmacy, University of Naples “Federico II”, Via D. Montesano, 49, 80131-Naples-Italy
| | - Anna Maria D’Ursi
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, 84084-Fisciano-Italy
| | - Manuela Rodriquez
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, 84084-Fisciano-Italy
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31
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Bode DC, Baker MD, Viles JH. Ion Channel Formation by Amyloid-β42 Oligomers but Not Amyloid-β40 in Cellular Membranes. J Biol Chem 2016; 292:1404-1413. [PMID: 27927987 DOI: 10.1074/jbc.m116.762526] [Citation(s) in RCA: 149] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/24/2016] [Indexed: 12/23/2022] Open
Abstract
A central hallmark of Alzheimer's disease is the presence of extracellular amyloid plaques chiefly consisting of amyloid-β (Aβ) peptides in the brain interstitium. Aβ largely exists in two isoforms, 40 and 42 amino acids long, but a large body of evidence points to Aβ(1-42) rather than Aβ(1-40) as the cytotoxic form. One proposed mechanism by which Aβ exerts toxicity is the formation of ion channel pores that disrupt intracellular Ca2+ homeostasis. However, previous studies using membrane mimetics have not identified any notable difference in the channel forming properties between Aβ(1-40) and Aβ(1-42). Here, we tested whether a more physiological environment, membranes excised from HEK293 cells of neuronal origin, would reveal differences in the relative channel forming ability of monomeric, oligomeric, and fibrillar forms of both Aβ(1-40) and Aβ(1-42). Aβ preparations were characterized with transmission electron microscopy and thioflavin T fluorescence. Aβ was then exposed to the extracellular face of excised membranes, and transmembrane currents were monitored using patch clamp. Our data indicated that Aβ(1-42) assemblies in oligomeric preparations form voltage-independent, non-selective ion channels. In contrast, Aβ(1-40) oligomers, fibers, and monomers did not form channels. Ion channel conductance results suggested that Aβ(1-42) oligomers, but not monomers and fibers, formed three distinct pore structures with 1.7-, 2.1-, and 2.4-nm pore diameters. Our findings demonstrate that only Aβ(1-42) contains unique structural features that facilitate membrane insertion and channel formation, now aligning ion channel formation with the differential neurotoxic effect of Aβ(1-40) and Aβ(1-42) in Alzheimer's disease.
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Affiliation(s)
- David C Bode
- From the School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom and
| | - Mark D Baker
- the Blizard Institute, Centre for Neuroscience and Trauma, Barts and The London School of Medicine and Dentistry, Queen Mary, University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - John H Viles
- From the School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom and
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Groblewska M, Muszyński P, Wojtulewska-Supron A, Kulczyńska-Przybik A, Mroczko B. The Role of Visinin-Like Protein-1 in the Pathophysiology of Alzheimer's Disease. J Alzheimers Dis 2016; 47:17-32. [PMID: 26402751 DOI: 10.3233/jad-150060] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Calcium ions are crucial in the process of information transmission and integration in the central nervous system (CNS). These ions participate not only in intracellular mechanisms but also in intercellular processes. The changes in the concentration of Ca2 + ions modulate synaptic transmission, whereas neuronal activity induces calcium ion waves. Disturbed calcium homeostasis is thought to be one of the main features in the pathophysiology of Alzheimer's disease (AD), and AD pathogenesis is closely connected to Ca2 + signaling pathways. The effects of changes in neuronal Ca2 + are mediated by neuronal calcium sensor (NCS) proteins. It has been revealed that NCS proteins, with special attention to visinin-like protein 1 (VILIP-1), might have a connection to the etiology of AD. In the CNS, VILIP-1 influences the intracellular neuronal signaling pathways involved in synaptic plasticity, such as cyclic nucleotide cascades and nicotinergic signaling. This particular protein is implicated in calcium-mediated neuronal injury as well. VILIP-1 also participates in the pathological mechanisms of altered Ca2 + homeostasis, leading to neuronal loss. These findings confirm the utility of VILIP-1 as a useful biomarker of neuronal injury. Moreover, VILIP-1 plays a vital role in linking calcium-mediated neurotoxicity and AD-type pathological changes. The disruption of Ca2 + homeostasis caused by AD-type neurodegeneration may result in the damage of VILIP-1-containing neurons in the brain, leading to increased cerebrospinal fluid levels of VILIP-1. Thus, the aim of this overview is to describe the relationships of the NCS protein VILIP-1 with the pathogenetic factors of AD and neurodegenerative processes, as well as its potential clinical usefulness as a biomarker of AD. Moreover, we describe the current and probable therapeutic strategies for AD, targeting calcium-signaling pathways and VILIP-1.
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Affiliation(s)
| | - Paweł Muszyński
- Department of Neurodegeneration Diagnostics, Medical University of Białystok, Poland
| | | | | | - Barbara Mroczko
- Department of Biochemical Diagnostics, University Hospital in Białystok, Poland.,Department of Neurodegeneration Diagnostics, Medical University of Białystok, Poland
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33
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Kepp KP. Alzheimer's disease due to loss of function: A new synthesis of the available data. Prog Neurobiol 2016; 143:36-60. [PMID: 27327400 DOI: 10.1016/j.pneurobio.2016.06.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 06/10/2016] [Accepted: 06/11/2016] [Indexed: 12/11/2022]
Abstract
Alzheimer's Disease (AD) is a highly complex disease involving a broad range of clinical, cellular, and biochemical manifestations that are currently not understood in combination. This has led to many views of AD, e.g. the amyloid, tau, presenilin, oxidative stress, and metal hypotheses. The amyloid hypothesis has dominated the field with its assumption that buildup of pathogenic β-amyloid (Aβ) peptide causes disease. This paradigm has been criticized, yet most data suggest that Aβ plays a key role in the disease. Here, a new loss-of-function hypothesis is synthesized that accounts for the anomalies of the amyloid hypothesis, e.g. the curious pathogenicity of the Aβ42/Aβ40 ratio, the loss of Aβ caused by presenilin mutation, the mixed phenotypes of APP mutations, the poor clinical-biochemical correlations for genetic variant carriers, and the failure of Aβ reducing drugs. The amyloid-loss view accounts for recent findings on the structure and chemical features of Aβ variants and their coupling to human patient data. The lost normal function of APP/Aβ is argued to be metal transport across neuronal membranes, a view with no apparent anomalies and substantially more explanatory power than the gain-of-function amyloid hypothesis. In the loss-of-function scenario, the central event of Aβ aggregation is interpreted as a loss of soluble, functional monomer Aβ rather than toxic overload of oligomers. Accordingly, new research models and treatment strategies should focus on remediation of the functional amyloid balance, rather than strict containment of Aβ, which, for reasons rationalized in this review, has failed clinically.
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Affiliation(s)
- Kasper P Kepp
- Technical University of Denmark, DTU Chemistry, DK-2800 Kongens Lyngby, Denmark.
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Di Scala C, Yahi N, Flores A, Boutemeur S, Kourdougli N, Chahinian H, Fantini J. Comparison of the amyloid pore forming properties of rat and human Alzheimer's beta-amyloid peptide 1-42: Calcium imaging data. Data Brief 2016; 6:640-3. [PMID: 26909380 PMCID: PMC4735473 DOI: 10.1016/j.dib.2016.01.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 12/22/2015] [Accepted: 01/09/2016] [Indexed: 11/30/2022] Open
Abstract
The data here consists of calcium imaging of human neuroblastoma SH-SY5Y cells treated with the calcium-sensitive dye Fluo-4AM and then incubated with nanomolar concentrations of either human or rat Alzheimer’s β-amyloid peptide Aβ1-42. These data are both of a qualitative (fluorescence micrographs) and semi-quantitative nature (estimation of intracellular calcium concentrations of cells probed by Aβ1-42 peptides vs. control untreated cells). Since rat Aβ1-42 differs from its human counterpart at only three amino acid positions, this comparative study is a good assessment of the specificity of the amyloid pore forming assay. The interpretation of this dataset is presented in the accompanying study “Broad neutralization of calcium-permeable amyloid pore channels with a chimeric Alzheimer/Parkinson peptide targeting brain gangliosides” [1].
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Affiliation(s)
- Coralie Di Scala
- Aix-Marseille Université, PPSN-EA4674, Faculté des Sciences, Marseille, France
| | - Nouara Yahi
- Aix-Marseille Université, PPSN-EA4674, Faculté des Sciences, Marseille, France
| | - Alessandra Flores
- Aix-Marseille Université, PPSN-EA4674, Faculté des Sciences, Marseille, France
| | - Sonia Boutemeur
- Aix-Marseille Université, PPSN-EA4674, Faculté des Sciences, Marseille, France
| | - Nazim Kourdougli
- INSERM, INMED, Parc Scientifique de Luminy, 13009 Marseille, France
| | - Henri Chahinian
- Aix-Marseille Université, PPSN-EA4674, Faculté des Sciences, Marseille, France
| | - Jacques Fantini
- Aix-Marseille Université, PPSN-EA4674, Faculté des Sciences, Marseille, France
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Jang H, Arce FT, Ramachandran S, Kagan BL, Lal R, Nussinov R. Disordered amyloidogenic peptides may insert into the membrane and assemble into common cyclic structural motifs. Chem Soc Rev 2014; 43:6750-64. [PMID: 24566672 PMCID: PMC4143503 DOI: 10.1039/c3cs60459d] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Aggregation of disordered amyloidogenic peptides into oligomers is the causative agent of amyloid-related diseases. In solution, disordered protein states are characterized by heterogeneous ensembles. Among these, β-rich conformers self-assemble via a conformational selection mechanism to form energetically-favored cross-β structures, regardless of their precise sequences. These disordered peptides can also penetrate the membrane, and electrophysiological data indicate that they form ion-conducting channels. Based on these and additional data, including imaging and molecular dynamics simulations of a range of amyloid peptides, Alzheimer's amyloid-β (Aβ) peptide, its disease-related variants with point mutations and N-terminal truncated species, other amyloidogenic peptides, as well as a cytolytic peptide and a synthetic gel-forming peptide, we suggest that disordered amyloidogenic peptides can also present a common motif in the membrane. The motif consists of curved, moon-like β-rich oligomers associated into annular organizations. The motif is favored in the lipid bilayer since it permits hydrophobic side chains to face and interact with the membrane and the charged/polar residues to face the solvated channel pores. Such channels are toxic since their pores allow uncontrolled leakage of ions into/out of the cell, destabilizing cellular ionic homeostasis. Here we detail Aβ, whose aggregation is associated with Alzheimer's disease (AD) and for which there are the most abundant data. AD is a protein misfolding disease characterized by a build-up of Aβ peptide as senile plaques, neurodegeneration, and memory loss. Excessively produced Aβ peptides may directly induce cellular toxicity, even without the involvement of membrane receptors through Aβ peptide-plasma membrane interactions.
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Affiliation(s)
- Hyunbum Jang
- Cancer and Inflammation Program, National Cancer Institute at Frederick, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, U.S.A
| | - Fernando Teran Arce
- Departments of Bioengineering and of Mechanical and Aerospace Engineering, and Materials Science Program, University of California, San Diego, La Jolla, California 92093, U.S.A
| | - Srinivasan Ramachandran
- Departments of Bioengineering and of Mechanical and Aerospace Engineering, and Materials Science Program, University of California, San Diego, La Jolla, California 92093, U.S.A
| | - Bruce L. Kagan
- Department of Psychiatry, David Geffen School of Medicine, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, California 90024, U.S.A
| | - Ratnesh Lal
- Departments of Bioengineering and of Mechanical and Aerospace Engineering, and Materials Science Program, University of California, San Diego, La Jolla, California 92093, U.S.A
| | - Ruth Nussinov
- Cancer and Inflammation Program, National Cancer Institute at Frederick, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, U.S.A
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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Kotler SA, Walsh P, Brender JR, Ramamoorthy A. Differences between amyloid-β aggregation in solution and on the membrane: insights into elucidation of the mechanistic details of Alzheimer's disease. Chem Soc Rev 2014; 43:6692-700. [PMID: 24464312 PMCID: PMC4110197 DOI: 10.1039/c3cs60431d] [Citation(s) in RCA: 307] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The association of the amyloid-β (Aβ) peptide with cellular membranes is hypothesized to be the underlying phenomenon of neurotoxicity in Alzheimer's disease. Misfolding of proteins and peptides, as is the case with Aβ, follows a progression from a monomeric state, through intermediates, ending at long, unbranched amyloid fibers. This tutorial review offers a perspective on the association of toxic Aβ structures with membranes as well as details of membrane-associated mechanisms of toxicity.
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Affiliation(s)
- Samuel A Kotler
- Biophysics and Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109-1055, USA.
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Berhanu WM, Hansmann UHE. Stability of amyloid oligomers. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2014; 96:113-41. [PMID: 25443956 DOI: 10.1016/bs.apcsb.2014.06.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Molecular simulations are now commonly used to complement experimental techniques in investigating amyloids and their role in human diseases. In this chapter, we will summarize techniques and approaches often used in amyloid simulations and will present recent success stories. Our examples will be focused on lessons learned from molecular dynamics simulations in aqueous environments that start from preformed aggregates. These studies explore the limitations that arise from the choice of force field, the role of mutations in the growth of amyloid aggregates, segmental polymorphism, and the importance of cross-seeding. Furthermore, they give evidence for potential toxicity mechanisms. We finally discuss the role of molecular simulations in the search for aggregation inhibitors.
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Affiliation(s)
- Workalemahu M Berhanu
- Department of Chemistry & Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
| | - Ulrich H E Hansmann
- Department of Chemistry & Biochemistry, University of Oklahoma, Norman, Oklahoma, USA.
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Task K, D'Amore A, Singh S, Candiello J, Jaramillo M, Wagner WR, Kumta P, Banerjee I. Systems level approach reveals the correlation of endoderm differentiation of mouse embryonic stem cells with specific microstructural cues of fibrin gels. J R Soc Interface 2014; 11:20140009. [PMID: 24718448 DOI: 10.1098/rsif.2014.0009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Stem cells receive numerous cues from their associated substrate that help to govern their behaviour. However, identification of influential substrate characteristics poses difficulties because of their complex nature. In this study, we developed an integrated experimental and systems level modelling approach to investigate and identify specific substrate features influencing differentiation of mouse embryonic stem cells (mESCs) on a model fibrous substrate, fibrin. We synthesized a range of fibrin gels by varying fibrinogen and thrombin concentrations, which led to a range of substrate stiffness and microstructure. mESCs were cultured on each of these gels, and characterization of the differentiated cells revealed a strong influence of substrate modulation on gene expression patterning. To identify specific substrate features influencing differentiation, the substrate microstructure was quantified by image analysis and correlated with stem cell gene expression patterns using a statistical model. Significant correlations were observed between differentiation and microstructure features, specifically fibre alignment. Furthermore, this relationship occurred in a lineage-specific manner towards endoderm. This systems level approach allows for identification of specific substrate features from a complex material which are influential to cellular behaviour. Such analysis may be effective in guiding the design of scaffolds with specific properties for tissue engineering applications.
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Affiliation(s)
- Keith Task
- Department of Chemical Engineering, University of Pittsburgh, , Pittsburgh, PA, USA
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Zhang Y, Shi ZG, Wang ZH, Li JG, Chen JY, Zhang C. Effects of amyloid β-peptide fragment 31-35 on the BK channel-mediated K⁺ current and intracellular free Ca²⁺ concentration of hippocampal CA1 neurons. Neurosci Lett 2014; 568:72-6. [PMID: 24680749 DOI: 10.1016/j.neulet.2014.03.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 03/12/2014] [Accepted: 03/19/2014] [Indexed: 12/23/2022]
Abstract
The present study characterizes the effects of Aβ31-35, a short active fragment of amyloid β-peptide (Aβ), upon the BK channel-mediated K⁺ current and intracellular free Ca²⁺ concentration ([Ca²⁺]i) of freshly dissociated pyramidal cells from rat CA1 hippocampus by using whole-cell patch-clamp recording and single cell Ca²⁺ imaging techniques. The results show that: (1) in the presence of voltage- and ATP-gated K⁺ channel blockers application of 5.0 μM Aβ31-35 significantly diminished transient outward K⁺ current amplitudes at clamped voltages between 0 and 45mV; (2) under the same conditions [Ca²⁺]i was minimally affected by 5.0 μM but significantly increased by 12.5 μM and 25 μM Aβ31-35; and (3) when 25 μM of a larger fragment of the amyloid β-peptide, Aβ25-35, was applied, the results were similar to those obtained with the same concentration of Aβ31-35. These results indicate that Aβ31-35 is likely to be the shortest active fragment of the full Aβ sequence, and can be as effectively as the full-length Aβ peptide in suppressing BK-channel mediated K⁺ currents and significantly elevating [Ca²⁺]i in hippocampal CA1 neurons.
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Affiliation(s)
- Yu Zhang
- Department of Neurobiology, Shanxi Key Laboratory of Cell Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
| | - Zhi-Gang Shi
- Department of Neurobiology, Shanxi Key Laboratory of Cell Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China
| | - Zhi-Hua Wang
- Department of Pathology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China
| | - Jian-Guo Li
- Department of Neurobiology, Shanxi Key Laboratory of Cell Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China
| | - Jin-Yuan Chen
- Functional Laboratory, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China
| | - Ce Zhang
- Department of Neurobiology, Shanxi Key Laboratory of Cell Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
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AβP1-42 incorporation and channel formation in planar lipid membranes: the role of cholesterol and its oxidation products. J Bioenerg Biomembr 2013; 45:369-81. [DOI: 10.1007/s10863-013-9513-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 04/12/2013] [Indexed: 02/06/2023]
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Candiello J, Singh SS, Task K, Kumta PN, Banerjee I. Early differentiation patterning of mouse embryonic stem cells in response to variations in alginate substrate stiffness. J Biol Eng 2013; 7:9. [PMID: 23570553 PMCID: PMC3643844 DOI: 10.1186/1754-1611-7-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 03/20/2013] [Indexed: 01/05/2023] Open
Abstract
Background Embryonic stem cells (ESCs) have been implicated to have tremendous impact in regenerative therapeutics of various diseases, including Type 1 Diabetes. Upon generation of functionally mature ESC derived islet-like cells, they need to be implanted into diabetic patients to restore the loss of islet activity. Encapsulation in alginate microcapsules is a promising route of implantation, which can protect the cells from the recipient’s immune system. While there has been a significant investigation into islet encapsulation over the past decade, the feasibility of encapsulation and differentiation of ESCs has been less explored. Research over the past few years has identified the cellular mechanical microenvironment to play a central role in phenotype commitment of stem cells. Therefore it will be important to design the encapsulation material to be supportive to cellular functionality and maturation. Results This work investigated the effect of stiffness of alginate substrate on initial differentiation and phenotype commitment of murine ESCs. ESCs grown on alginate substrates tuned to similar biomechanical properties of native pancreatic tissue elicited both an enhanced and incrementally responsive differentiation towards endodermal lineage traits. Conclusions The insight into these biophysical phenomena found in this study can be used along with other cues to enhance the differentiation of embryonic stem cells toward a specific lineage fate.
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Affiliation(s)
- Joseph Candiello
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
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Burke KA, Yates EA, Legleiter J. Biophysical insights into how surfaces, including lipid membranes, modulate protein aggregation related to neurodegeneration. Front Neurol 2013; 4:17. [PMID: 23459674 PMCID: PMC3585431 DOI: 10.3389/fneur.2013.00017] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 02/09/2013] [Indexed: 11/13/2022] Open
Abstract
There are a vast number of neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and Huntington’s disease (HD), associated with the rearrangement of specific proteins to non-native conformations that promotes aggregation and deposition within tissues and/or cellular compartments. These diseases are commonly classified as protein-misfolding or amyloid diseases. The interaction of these proteins with liquid/surface interfaces is a fundamental phenomenon with potential implications for protein-misfolding diseases. Kinetic and thermodynamic studies indicate that significant conformational changes can be induced in proteins encountering surfaces, which can play a critical role in nucleating aggregate formation or stabilizing specific aggregation states. Surfaces of particular interest in neurodegenerative diseases are cellular and subcellular membranes that are predominately comprised of lipid components. The two-dimensional liquid environments provided by lipid bilayers can profoundly alter protein structure and dynamics by both specific and non-specific interactions. Importantly for misfolding diseases, these bilayer properties can not only modulate protein conformation, but also exert influence on aggregation state. A detailed understanding of the influence of (sub)cellular surfaces in driving protein aggregation and/or stabilizing specific aggregate forms could provide new insights into toxic mechanisms associated with these diseases. Here, we review the influence of surfaces in driving and stabilizing protein aggregation with a specific emphasis on lipid membranes.
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Affiliation(s)
- Kathleen A Burke
- C. Eugene Bennett Department of Chemistry, West Virginia University Morgantown, WV, USA
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Death by a thousand cuts in Alzheimer's disease: hypoxia--the prodrome. Neurotox Res 2013; 24:216-43. [PMID: 23400634 DOI: 10.1007/s12640-013-9379-2] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 01/10/2013] [Accepted: 01/21/2013] [Indexed: 12/30/2022]
Abstract
A wide range of clinical consequences may be associated with obstructive sleep apnea (OSA) including systemic hypertension, cardiovascular disease, pulmonary hypertension, congestive heart failure, cerebrovascular disease, glucose intolerance, impotence, gastroesophageal reflux, and obesity, to name a few. Despite this, 82 % of men and 93 % of women with OSA remain undiagnosed. OSA affects many body systems, and induces major alterations in metabolic, autonomic, and cerebral functions. Typically, OSA is characterized by recurrent chronic intermittent hypoxia (CIH), hypercapnia, hypoventilation, sleep fragmentation, peripheral and central inflammation, cerebral hypoperfusion, and cerebral glucose hypometabolism. Upregulation of oxidative stress in OSA plays an important pathogenic role in the milieu of hypoxia-induced cerebral and cardiovascular dysfunctions. Strong evidence underscores that cerebral amyloidogenesis and tau phosphorylation--two cardinal features of Alzheimer's disease (AD), are triggered by hypoxia. Mice subjected to hypoxic conditions unambiguously demonstrated upregulation in cerebral amyloid plaque formation and tau phosphorylation, as well as memory deficit. Hypoxia triggers neuronal degeneration and axonal dysfunction in both cortex and brainstem. Consequently, neurocognitive impairment in apneic/hypoxic patients is attributable to a complex interplay between CIH and stimulation of several pathological trajectories. The framework presented here helps delineate the emergence and progression of cognitive decline, and may yield insight into AD neuropathogenesis. The global impact of CIH should provide a strong rationale for treating OSA and snoring clinically, in order to ameliorate neurocognitive impairment in aged/AD patients.
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Poojari C, Kukol A, Strodel B. How the amyloid-β peptide and membranes affect each other: An extensive simulation study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:327-39. [DOI: 10.1016/j.bbamem.2012.09.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 09/03/2012] [Accepted: 09/04/2012] [Indexed: 11/24/2022]
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Tofoleanu F, Buchete NV. Alzheimer Aβ peptide interactions with lipid membranes: fibrils, oligomers and polymorphic amyloid channels. Prion 2012; 6:339-45. [PMID: 22874669 PMCID: PMC3609060 DOI: 10.4161/pri.21022] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Fibrillar aggregates of misfolded amyloid proteins are involved in a variety of diseases such as Alzheimer disease (AD), type 2 diabetes, Parkinson, Huntington and prion-related diseases. In the case of AD amyloid β (Aβ) peptides, the toxicity of amyloid oligomers and larger fibrillar aggregates is related to perturbing the biological function of the adjacent cellular membrane. We used atomistic molecular dynamics (MD) simulations of Aβ9–40 fibrillar oligomers modeled as protofilament segments, including lipid bilayers and explicit water molecules, to probe the first steps in the mechanism of Aβ-membrane interactions. Our study identified the electrostatic interaction between charged peptide residues and the lipid headgroups as the principal driving force that can modulate the further penetration of the C-termini of amyloid fibrils or fibrillar oligomers into the hydrophobic region of lipid membranes. These findings advance our understanding of the detailed molecular mechanisms and the effects related to Aβ-membrane interactions, and suggest a polymorphic structural character of amyloid ion channels embedded in lipid bilayers. While inter-peptide hydrogen bonds leading to the formation of β-strands may still play a stabilizing role in amyloid channel structures, these may also present a significant helical content in peptide regions (e.g., termini) that are subject to direct interactions with lipids rather than with neighboring Aβ peptides.
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Protective effects of curcumin on amyloid-β-induced neuronal oxidative damage. Neurochem Res 2012; 37:1584-97. [PMID: 22476982 DOI: 10.1007/s11064-012-0754-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 02/09/2012] [Accepted: 03/08/2012] [Indexed: 12/21/2022]
Abstract
To investigate the protective effects of curcumin against amyloid-β (Aβ)-induced neuronal damage. Primary rat cortical neurons were cultured with different treatments of Aβ and curcumin. Neuronal morphologies, viability and damage were assessed. Neuronal oxidative stress was assessed, including extracellular hydrogen peroxide and intracellular reactive oxygen species. The abilities of curcumin to scavenge free radicals and to inhibit Aβ aggregation and β-sheeted formation are further assessed and discussed. Curcumin preserves cell viability, which is decreased by Aβ. The results of changed morphology, released Lactate dehydrogenases and cell viability assays indicate that curcumin protects Aβ-induced neuronal damage. Curcumin depresses Aβ-induced up-regulation of neuronal oxidative stress. The treatment sequence impacts the protective effect of curcumin on Aβ-induced neuronal damage. Curcumin shows a more protective effect on neuronal oxidative damage when curcumin was added into cultured neurons not later than Aβ, especially prior to Aβ. The abilities of curcumin to scavenge free radicals and to inhibit the formation of β-sheeted aggregation are both beneficial to depress Aβ-induced oxidative damage. Curcumin prevents neurons from Aβ-induced oxidative damage, implying the therapeutic usage for the treatment of Alzheimer's disease patients.
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Connelly L, Arce FT, Jang H, Capone R, Kotler SA, Ramachandran S, Kagan BL, Nussinov R, Lal R. Atomic force microscopy and MD simulations reveal pore-like structures of all-D-enantiomer of Alzheimer's β-amyloid peptide: relevance to the ion channel mechanism of AD pathology. J Phys Chem B 2012; 116:1728-35. [PMID: 22217000 PMCID: PMC4342054 DOI: 10.1021/jp2108126] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is a protein misfolding disease characterized by a buildup of β-amyloid (Aβ) peptide as senile plaques, uncontrolled neurodegeneration, and memory loss. AD pathology is linked to the destabilization of cellular ionic homeostasis and involves Aβ peptide-plasma membrane interactions. In principle, there are two possible ways through which disturbance of the ionic homeostasis can take place: directly, where the Aβ peptide either inserts into the membrane and creates ion-conductive pores or destabilizes the membrane organization, or, indirectly, where the Aβ peptide interacts with existing cell membrane receptors. To distinguish between these two possible types of Aβ-membrane interactions, we took advantage of the biochemical tenet that ligand-receptor interactions are stereospecific; L-amino acid peptides, but not their D-counterparts, bind to cell membrane receptors. However, with respect to the ion channel-mediated mechanism, like L-amino acids, D-amino acid peptides will also form ion channel-like structures. Using atomic force microscopy (AFM), we imaged the structures of both D- and L-enantiomers of the full length Aβ(1-42) when reconstituted in lipid bilayers. AFM imaging shows that both L- and D-Aβ isomers form similar channel-like structures. Molecular dynamics (MD) simulations support the AFM imaged 3D structures. Previously, we have shown that D-Aβ(1-42) channels conduct ions similarly to their L- counterparts. Taken together, our results support the direct mechanism of Aβ ion channel-mediated destabilization of ionic homeostasis rather than the indirect mechanism through Aβ interaction with membrane receptors.
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Affiliation(s)
- Laura Connelly
- Departments of Bioengineering and of Mechanical and Aerospace Engineering and Materials Science Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Fernando Teran Arce
- Departments of Bioengineering and of Mechanical and Aerospace Engineering and Materials Science Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Hyunbum Jang
- Center for Cancer Research Nanobiology Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, MD 21702, USA
| | - Ricardo Capone
- Departments of Bioengineering and of Mechanical and Aerospace Engineering and Materials Science Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Samuel A. Kotler
- Departments of Bioengineering and of Mechanical and Aerospace Engineering and Materials Science Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Srinivasan Ramachandran
- Departments of Bioengineering and of Mechanical and Aerospace Engineering and Materials Science Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Bruce L. Kagan
- Department of Psychiatry, David Geffen School of Medicine, Semel Institute for Neuroscience Human Behavior, University of California, Los Angeles, CA 90024, USA
| | - Ruth Nussinov
- Center for Cancer Research Nanobiology Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, MD 21702, USA
| | - Ratnesh Lal
- Departments of Bioengineering and of Mechanical and Aerospace Engineering and Materials Science Program, University of California, San Diego, La Jolla, CA 92093, USA
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Positive evolutionary selection of an HD motif on Alzheimer precursor protein orthologues suggests a functional role. PLoS Comput Biol 2012; 8:e1002356. [PMID: 22319430 PMCID: PMC3271017 DOI: 10.1371/journal.pcbi.1002356] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 12/07/2011] [Indexed: 12/31/2022] Open
Abstract
HD amino acid duplex has been found in the active center of many different enzymes. The dyad plays remarkably different roles in their catalytic processes that usually involve metal coordination. An HD motif is positioned directly on the amyloid beta fragment (Aβ) and on the carboxy-terminal region of the extracellular domain (CAED) of the human amyloid precursor protein (APP) and a taxonomically well defined group of APP orthologues (APPOs). In human Aβ HD is part of a presumed, RGD-like integrin-binding motif RHD; however, neither RHD nor RXD demonstrates reasonable conservation in APPOs. The sequences of CAEDs and the position of the HD are not particularly conserved either, yet we show with a novel statistical method using evolutionary modeling that the presence of HD on CAEDs cannot be the result of neutral evolutionary forces (p<0.0001). The motif is positively selected along the evolutionary process in the majority of APPOs, despite the fact that HD motif is underrepresented in the proteomes of all species of the animal kingdom. Position migration can be explained by high probability occurrence of multiple copies of HD on intermediate sequences, from which only one is kept by selective evolutionary forces, in a similar way as in the case of the “transcription binding site turnover.” CAED of all APP orthologues and homologues are predicted to bind metal ions including Amyloid-like protein 1 (APLP1) and Amyloid-like protein 2 (APLP2). Our results suggest that HDs on the CAEDs are most probably key components of metal-binding domains, which facilitate and/or regulate inter- or intra-molecular interactions in a metal ion-dependent or metal ion concentration-dependent manner. The involvement of naturally occurring mutations of HD (Tottori (D7N) and English (H6R) mutations) in early onset Alzheimer's disease gives additional support to our finding that HD has an evolutionary preserved function on APPOs. HD amino acid duplex can be found in the active center of different metallo-enzymes. An HD motif is positioned directly on the amyloid beta (Aβ) fragment and on the carboxy-terminal region of the extracellular domain of the human amyloid precursor protein (APP) and a taxonomically well defined group of APP orthologues (APPOs). The conservation of the HD dyad is not position specific and it cannot be seen in a multiple alignment. Yet we show with a novel statistical method using evolutionary modeling that HD motif is positively selected by evolution on APPOs, despite the fact that HD dyad is underrepresented in the proteomes of all species of the animal kingdom. CAED of all APP orthologues and homologues are predicted to bind metal ions including Amyloid-like protein 1 (APLP1) and Amyloid-like protein 2 (APLP2). Our results suggest that HDs on the APPOs are most probably key components of metal-binding domains, which facilitate and/or regulate inter- or intra-molecular interactions in a metal ion-dependent or metal ion concentration-dependent manner. The involvement of naturally occurring mutations of HD (Tottori (D7N) and English (H6R)) in early onset Alzheimer's disease gives additional support to our finding that HD has an evolutionary preserved function on APPOs.
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