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Ahyayauch H, Masserini ME, Alonso A, Goñi FM. Understanding Aβ Peptide Binding to Lipid Membranes: A Biophysical Perspective. Int J Mol Sci 2024; 25:6401. [PMID: 38928107 PMCID: PMC11203662 DOI: 10.3390/ijms25126401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 05/27/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024] Open
Abstract
Aβ peptides are known to bind neural plasma membranes in a process leading to the deposit of Aβ-enriched plaques. These extracellular structures are characteristic of Alzheimer's disease, the major cause of late-age dementia. The mechanisms of Aβ plaque formation and deposition are far from being understood. A vast number of studies in the literature describe the efforts to analyze those mechanisms using a variety of tools. The present review focuses on biophysical studies mostly carried out with model membranes or with computational tools. This review starts by describing basic physical aspects of lipid phases and commonly used model membranes (monolayers and bilayers). This is followed by a discussion of the biophysical techniques applied to these systems, mainly but not exclusively Langmuir monolayers, isothermal calorimetry, density-gradient ultracentrifugation, and molecular dynamics. The Methodological Section is followed by the core of the review, which includes a summary of important results obtained with each technique. The last section is devoted to an overall reflection and an effort to understand Aβ-bilayer binding. Concepts such as Aβ peptide membrane binding, adsorption, and insertion are defined and differentiated. The roles of membrane lipid order, nanodomain formation, and electrostatic forces in Aβ-membrane interaction are separately identified and discussed.
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Affiliation(s)
- Hasna Ahyayauch
- Departamento de Bioquímica, Instituto Biofisika (CSIC, UPV/EHU), Universidad del País Vasco, 48940 Leioa, Spain; (H.A.); (A.A.)
- Institut Supérieur des Professions Infirmières et Techniques de Santé, Rabat 60000, Morocco
- Laboratoire de Biologie et Santé, Unité Neurosciences, Neuroimmunologie et Comportement, Faculty of Sciences, Ibn Tofail University, Kénitra 14000, Morocco
| | - Massimo E. Masserini
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy;
| | - Alicia Alonso
- Departamento de Bioquímica, Instituto Biofisika (CSIC, UPV/EHU), Universidad del País Vasco, 48940 Leioa, Spain; (H.A.); (A.A.)
| | - Félix M. Goñi
- Departamento de Bioquímica, Instituto Biofisika (CSIC, UPV/EHU), Universidad del País Vasco, 48940 Leioa, Spain; (H.A.); (A.A.)
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2
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Huang Z. Evidence that Alzheimer's Disease Is a Disease of Competitive Synaptic Plasticity Gone Awry. J Alzheimers Dis 2024; 99:447-470. [PMID: 38669548 PMCID: PMC11119021 DOI: 10.3233/jad-240042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024]
Abstract
Mounting evidence indicates that a physiological function of amyloid-β (Aβ) is to mediate neural activity-dependent homeostatic and competitive synaptic plasticity in the brain. I have previously summarized the lines of evidence supporting this hypothesis and highlighted the similarities between Aβ and anti-microbial peptides in mediating cell/synapse competition. In cell competition, anti-microbial peptides deploy a multitude of mechanisms to ensure both self-protection and competitor elimination. Here I review recent studies showing that similar mechanisms are at play in Aβ-mediated synapse competition and perturbations in these mechanisms underpin Alzheimer's disease (AD). Specifically, I discuss evidence that Aβ and ApoE, two crucial players in AD, co-operate in the regulation of synapse competition. Glial ApoE promotes self-protection by increasing the production of trophic monomeric Aβ and inhibiting its assembly into toxic oligomers. Conversely, Aβ oligomers, once assembled, promote the elimination of competitor synapses via direct toxic activity and amplification of "eat-me" signals promoting the elimination of weak synapses. I further summarize evidence that neuronal ApoE may be part of a gene regulatory network that normally promotes competitive plasticity, explaining the selective vulnerability of ApoE expressing neurons in AD brains. Lastly, I discuss evidence that sleep may be key to Aβ-orchestrated plasticity, in which sleep is not only induced by Aβ but is also required for Aβ-mediated plasticity, underlining the link between sleep and AD. Together, these results strongly argue that AD is a disease of competitive synaptic plasticity gone awry, a novel perspective that may promote AD research.
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Affiliation(s)
- Zhen Huang
- Departments of Neuroscience and Neurology, University of Wisconsin-Madison, Madison, WI, USA
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3
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Robinson J, Sarangi NK, Keyes TE. Role of phosphatidylserine in amyloid-beta oligomerization at asymmetric phospholipid bilayers. Phys Chem Chem Phys 2023; 25:7648-7661. [PMID: 36317678 DOI: 10.1039/d2cp03344e] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Amyloid-beta (Aβ1-42) aggregation triggers neurotoxicity and is linked to Alzheimer's disease. Aβ1-42 oligomers, rather than extended fibrils, adhere to the cell membrane, causing cell death. Phosphatidylserine (PS), an anionic phospholipid, is prevalent in neuronal membranes (< 20 molar percentage) and, while isolated to the cytoplasmic leaflet of the membrane in healthy cells, its exposure in apoptotic cells and migration to exoplasmic leaflet is triggered by oxidative damage to the membrane. It is widely believed that PS plays a crucial role in the Aβ peptide interaction in the membranes of neuronal cells. However, due to the complexity of the cell membrane, it can be challenging to address molecular level understanding of the PS-Aβ binding and oligomerization processes. Herein, we use microcavity supported lipid bilayers (MSLBs) to analyse PS and Aβ1-42 binding, oligomer formation, and membrane damage. MSLBs are a useful model to evaluate protein-membrane interactions because of their cell-like dual aspect fluidity, their addressability and compositional versatility. We used electrochemical impedance spectroscopy (EIS) and confocal fluorescence microscopy to compare the impact of Aβ1-42 on simple zwitterioinic membrane, dioleoylphosphatidylcholine (DOPC), with MSLBs comprised of transversally asymmetric binary DOPC and dioleoylphosphatidylserine (DOPS). Monomeric Aβ1-42 adsorbs weakly to the pristine zwitterionic DOPC membrane without aggregation. Using a membrane integrity test, with pyranine trapped within the cavities beneath the membrane, Aβ1-42 exposure did not result in pyranine leakage, indicating that DOPC membranes were intact. When 10 mol% DOPS was doped asymmetrically into the membrane's outer leaflet, oligomerization of Aβ1-42 monomer was evident in EIS and atomic force microscopy (AFM), and confocal imaging revealed that membrane damage, resulted in extensive pyranine leakage from the pores. The effects were time, and DOPS and Aβ1-42 concentration-dependent. Membrane pore formation was visible within 30 minutes, and oligomerization, membrane-oligomer multilayer, and Aβ1-42 fibril formation evident over 3 to 18 hours. In asymmetric membranes with DOPS localized to the lower leaflet, optothermally (laser induced) damage increased local DOPS concentrations at the distal leaflet, promoting Aβ1-42 aggregation.
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Affiliation(s)
- Jack Robinson
- School of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - Nirod Kumar Sarangi
- School of Chemical Sciences, Dublin City University, Dublin 9, Ireland.,National Center for Sensor Research, Dublin City University, Dublin 9, Ireland.
| | - Tia E Keyes
- School of Chemical Sciences, Dublin City University, Dublin 9, Ireland.,National Center for Sensor Research, Dublin City University, Dublin 9, Ireland.
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4
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Loh D, Reiter RJ. Melatonin: Regulation of Biomolecular Condensates in Neurodegenerative Disorders. Antioxidants (Basel) 2021; 10:1483. [PMID: 34573116 PMCID: PMC8465482 DOI: 10.3390/antiox10091483] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Biomolecular condensates are membraneless organelles (MLOs) that form dynamic, chemically distinct subcellular compartments organizing macromolecules such as proteins, RNA, and DNA in unicellular prokaryotic bacteria and complex eukaryotic cells. Separated from surrounding environments, MLOs in the nucleoplasm, cytoplasm, and mitochondria assemble by liquid-liquid phase separation (LLPS) into transient, non-static, liquid-like droplets that regulate essential molecular functions. LLPS is primarily controlled by post-translational modifications (PTMs) that fine-tune the balance between attractive and repulsive charge states and/or binding motifs of proteins. Aberrant phase separation due to dysregulated membrane lipid rafts and/or PTMs, as well as the absence of adequate hydrotropic small molecules such as ATP, or the presence of specific RNA proteins can cause pathological protein aggregation in neurodegenerative disorders. Melatonin may exert a dominant influence over phase separation in biomolecular condensates by optimizing membrane and MLO interdependent reactions through stabilizing lipid raft domains, reducing line tension, and maintaining negative membrane curvature and fluidity. As a potent antioxidant, melatonin protects cardiolipin and other membrane lipids from peroxidation cascades, supporting protein trafficking, signaling, ion channel activities, and ATPase functionality during condensate coacervation or dissolution. Melatonin may even control condensate LLPS through PTM and balance mRNA- and RNA-binding protein composition by regulating N6-methyladenosine (m6A) modifications. There is currently a lack of pharmaceuticals targeting neurodegenerative disorders via the regulation of phase separation. The potential of melatonin in the modulation of biomolecular condensate in the attenuation of aberrant condensate aggregation in neurodegenerative disorders is discussed in this review.
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Affiliation(s)
- Doris Loh
- Independent Researcher, Marble Falls, TX 78654, USA
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, TX 78229, USA
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5
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Huang Y, Chang Y, Liu L, Wang J. Nanomaterials for Modulating the Aggregation of β-Amyloid Peptides. Molecules 2021; 26:4301. [PMID: 34299575 PMCID: PMC8305396 DOI: 10.3390/molecules26144301] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/09/2021] [Accepted: 07/09/2021] [Indexed: 12/13/2022] Open
Abstract
The aberrant aggregation of amyloid-β (Aβ) peptides in the brain has been recognized as the major hallmark of Alzheimer's disease (AD). Thus, the inhibition and dissociation of Aβ aggregation are believed to be effective therapeutic strategiesforthe prevention and treatment of AD. When integrated with traditional agents and biomolecules, nanomaterials can overcome their intrinsic shortcomings and boost their efficiency via synergistic effects. This article provides an overview of recent efforts to utilize nanomaterials with superior properties to propose effective platforms for AD treatment. The underlying mechanismsthat are involved in modulating Aβ aggregation are discussed. The summary of nanomaterials-based modulation of Aβ aggregation may help researchers to understand the critical roles in therapeutic agents and provide new insight into the exploration of more promising anti-amyloid agents and tactics in AD theranostics.
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Affiliation(s)
- Yaliang Huang
- Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
- Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang 455000, China;
| | - Yong Chang
- Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang 455000, China;
| | - Lin Liu
- Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang 455000, China;
| | - Jianxiu Wang
- Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
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6
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Hou YJ, Zheng X, Zhong HM, Chen F, Yan GY, Cai KC. Structural dynamics of amyloid β peptide binding to acetylcholine receptor and virtual screening for effective inhibitors. CHINESE J CHEM PHYS 2021. [DOI: 10.1063/1674-0068/cjcp2008150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Yan-jun Hou
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, China
- Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, China
- Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, China
| | - Xuan Zheng
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Hong-mei Zhong
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, China
- Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, China
- Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, China
| | - Feng Chen
- Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, China
| | - Gui-yang Yan
- Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, China
| | - Kai-cong Cai
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, China
- Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, China
- Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, China
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7
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Changhong K, Peng Y, Yuan Z, Cai J. Ginsenoside Rb1 protected PC12 cells from Aβ 25-35-induced cytotoxicity via PPARγ activation and cholesterol reduction. Eur J Pharmacol 2020; 893:173835. [PMID: 33359145 DOI: 10.1016/j.ejphar.2020.173835] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 12/09/2020] [Accepted: 12/18/2020] [Indexed: 12/27/2022]
Abstract
Accumulating evidences suggest that amyloid β (Aβ)-peptide plays a key role in pathogenesis of Alzheimer's disease (AD) through aggregation and deposition into plaques in neuronal cells. Membrane components such as cholesterol and gangliosides not only enhance the production of amyloidogenic Aβ fragments, but also appear to strengthen Aβ-membrane interaction. Ginsenoside Rb1 (GRb1) is a major active component of Panax, which is widely used to improve learning and memory. In the present study, whether ginsenoside Rb1 could protect pheochromocytoma cells (PC12 cells) from Aβ25-35-induced cytotoxicity including inhibiting cell growth, inducing apoptosis, producing reactive oxygen species (ROS), destroying the cytoskeleton and bringing about membrane toxicity was investigated. Our results indicated that ginsenoside Rb1 could serve as an agonist of peroxisom proliferator-activated receptor-γ (PPARγ) and reduce the level of cholesterol in AD model cells. Reduction of the Aβ25-35-induced cytotoxicity by lowering cholesterol was evidenced by reduction of ROS production, lipid peroxidation, and protection of cytoskeleton and membrane surface rigidity. Most importantly, the viability of PC12 cells increased from 50.42 ± 5.51% for the AD group to 102.72 ± 4.34% for the 50 μM ginsenoside Rb1 group with cholesterol reduction. Our results suggested that ginsenoside Rb1 might function as an effective candidate to promote reverse cholesterol transport and lower ROS production, therefore providing a new insight into prevention and treatment of AD.
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Affiliation(s)
- Ke Changhong
- Department of Chemistry, Jinan University, Guangzhou, 510632, China; YZ Health-tech Inc., Hengqin District, Zhuhai, 519000, China
| | - Yuan Peng
- Department of Chemistry, Jinan University, Guangzhou, 510632, China
| | - Zhengqiang Yuan
- Institute of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, 51006, China.
| | - Jiye Cai
- Department of Chemistry, Jinan University, Guangzhou, 510632, China.
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8
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The interaction of Aβ42 peptide in monomer, oligomer or fibril forms with sphingomyelin/cholesterol/ganglioside bilayers. Int J Biol Macromol 2020; 168:611-619. [PMID: 33217464 DOI: 10.1016/j.ijbiomac.2020.11.112] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/11/2020] [Accepted: 11/16/2020] [Indexed: 12/12/2022]
Abstract
Aβ42 peptide binds neuronal membranes and aggregates into plaques that are characteristic of Alzheimer's disease. Aβ42 peptide has been proposed to be generated in membrane (nano) domains in the liquid-ordered phase, ganglioside GM1 being a major facilitator of peptide binding to the membrane. The peptide exists in solution in various degrees of aggregation, either monomers, oligomers or fibrils, of which oligomers appear to be particularly toxic. The present study reports on the binding of Aβ42 peptide, in monomer, oligomer or fibril form, to model membranes (lipid vesicles or monolayers), composed of sphingomyelin and cholesterol in equimolar ratios, to which 1-5 mol% of different gangliosides were incorporated. Thermodynamic binding parameters obtained from calorimetric data indicate a strong tendency to bind the membrane (ΔG ≈ 7 kcal/mol peptide), in a process dominated in most cases by the increase in entropy. ΔG was virtually invariant with the ganglioside species and the aggregation state of the peptide. The Langmuir balance demonstrated the capacity of all peptide preparations to become inserted in lipid monolayers of any composition and initial π in the range 10-30 mN/m, although fibrils were less capable to do so than oligomers or monomers, their maximum initial π being ≈25 mN/m.
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9
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Alvarez AB, Caruso B, Rodríguez PEA, Petersen SB, Fidelio GD. Aβ-Amyloid Fibrils Are Self-Triggered by the Interfacial Lipid Environment and Low Peptide Content. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:8056-8065. [PMID: 32551671 DOI: 10.1021/acs.langmuir.0c00468] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We studied the surface properties of Aβ(1-40) amyloid peptides mixed with 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) (liquid state) or 1,2-disteraoyl-phosphatidylcholine (DSPC) (solid state) phospholipids by using nanostructured lipid/peptide films (Langmuir monolayers). Pure Aβ(1-40) amyloid peptides form insoluble monolayers without forming fibril-like structures. In a lipid environment [phospholipid/Aβ(1-40) peptide mixtures], we observed that both miscibility and stability of the films depend on the peptide content. At low Aβ(1-40) amyloid peptide proportion (from 2.5 to 10% of peptide area proportion), we observed the formation of a fibril-like structure when mixed only with POPC lipids. The stability acquired by these mixed films is within 20-35 mN·m-1 compatible with the equivalent surface pressure postulated for natural biomembranes. Fibrils are clearly evidenced directly from the monolayers by using Brewster angle microscopy. The so-called nanostructured fibrils are thioflavin T positive when observed by fluorescence microscopy. The amyloid fibril network at the surface was also evidenced by atomic force microscopy when the films are transferred onto a mica support. Aβ(1-40) amyloid mixed with the solid DSPC lipid showed an immiscible behavior in all peptide proportions without fibril formation. We postulated that the amyloid fibrillogenesis at the membrane can be dynamically nano-self-triggered at the surface by the quality of the interfacial environment, that is, the physical state of the water-lipid interface and the relative content of amyloid protein present at the interface.
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Affiliation(s)
- Alain Bolaño Alvarez
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Cordoba X5000HUA, Argentina
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Cordoba X5000HUA, Argentina
| | - Benjamín Caruso
- Cátedra de Química Biológica, Departamento de Química, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba X5016GCA, Argentina
- Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT), CONICET, Universidad Nacional de Córdoba, Córdoba X5016GCA, Argentina
| | - Pablo E A Rodríguez
- Ministerio de Ciencia y Tecnología de la Provincia de Córdoba, Cordoba X5004AAP, Argentina
| | - Steffen B Petersen
- Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg 9220, Denmark
| | - Gerardo D Fidelio
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Cordoba X5000HUA, Argentina
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET, Universidad Nacional de Córdoba, Cordoba X5000HUA, Argentina
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10
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Fabiani C, Antollini SS. Alzheimer's Disease as a Membrane Disorder: Spatial Cross-Talk Among Beta-Amyloid Peptides, Nicotinic Acetylcholine Receptors and Lipid Rafts. Front Cell Neurosci 2019; 13:309. [PMID: 31379503 PMCID: PMC6657435 DOI: 10.3389/fncel.2019.00309] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/25/2019] [Indexed: 12/17/2022] Open
Abstract
Biological membranes show lateral and transverse asymmetric lipid distribution. Cholesterol (Chol) localizes in both hemilayers, but in the external one it is mostly condensed in lipid-ordered microdomains (raft domains), together with saturated phosphatidyl lipids and sphingolipids (including sphingomyelin and glycosphingolipids). Membrane asymmetries induce special membrane biophysical properties and behave as signals for several physiological and/or pathological processes. Alzheimer’s disease (AD) is associated with a perturbation in different membrane properties. Amyloid-β (Aβ) plaques and neurofibrillary tangles of tau protein together with neuroinflammation and neurodegeneration are the most characteristic cellular changes observed in this disease. The extracellular presence of Aβ peptides forming senile plaques, together with soluble oligomeric species of Aβ, are considered the major cause of the synaptic dysfunction of AD. The association between Aβ peptide and membrane lipids has been extensively studied. It has been postulated that Chol content and Chol distribution condition Aβ production and posterior accumulation in membranes and, hence, cell dysfunction. Several lines of evidence suggest that Aβ partitions in the cell membrane accumulate mostly in raft domains, the site where the cleavage of the precursor AβPP by β- and γ- secretase is also thought to occur. The main consequence of the pathogenesis of AD is the disruption of the cholinergic pathways in the cerebral cortex and in the basal forebrain. In parallel, the nicotinic acetylcholine receptor has been extensively linked to membrane properties. Since its transmembrane domain exhibits extensive contacts with the surrounding lipids, the acetylcholine receptor function is conditioned by its lipid microenvironment. The nicotinic acetylcholine receptor is present in high-density clusters in the cell membrane where it localizes mainly in lipid-ordered domains. Perturbations of sphingomyelin or cholesterol composition alter acetylcholine receptor location. Therefore, Aβ processing, Aβ partitioning, and acetylcholine receptor location and function can be manipulated by changes in membrane lipid biophysics. Understanding these mechanisms should provide insights into new therapeutic strategies for prevention and/or treatment of AD. Here, we discuss the implications of lipid-protein interactions at the cell membrane level in AD.
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Affiliation(s)
- Camila Fabiani
- Instituto de Investigaciones Bioquímicas de Bahía Blanca CONICET-UNS, Bahía Blanca, Argentina.,Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Silvia S Antollini
- Instituto de Investigaciones Bioquímicas de Bahía Blanca CONICET-UNS, Bahía Blanca, Argentina.,Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
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11
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Maity BK, Das AK, Dey S, Moorthi UK, Kaur A, Dey A, Surendran D, Pandit R, Kallianpur M, Chandra B, Chandrakesan M, Arumugam S, Maiti S. Ordered and Disordered Segments of Amyloid-β Drive Sequential Steps of the Toxic Pathway. ACS Chem Neurosci 2019; 10:2498-2509. [PMID: 30763064 DOI: 10.1021/acschemneuro.9b00015] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
While the roles of intrinsically disordered protein domains in driving interprotein interactions are increasingly well-appreciated, the mechanism of toxicity of disease-causing disordered proteins remains poorly understood. A prime example is Alzheimer's disease (AD) associated amyloid beta (Aβ). Aβ oligomers are highly toxic partially structured peptide assemblies with a distinct ordered region (residues ∼10-40) and a shorter disordered region (residues ∼1-9). Here, we investigate the role of this disordered domain and its relation to the ordered domain in the manifestation of toxicity through a set of Aβ fragments and stereoisomers designed for this purpose. We measure their effects on lipid membranes and cultured neurons, probing their toxicity, intracellular distributions, and specific molecular interactions using the techniques of confocal imaging, lattice light sheet imaging, fluorescence lifetime imaging, and fluorescence correlation spectroscopy. Remarkably, we find that neither part-Aβ10-40 or Aβ1-9, is toxic by itself. The ordered part (Aβ10-40) is the major determinant of how Aβ attaches to lipid bilayers, enters neuronal cells, and localizes primarily in the late endosomal compartments. However, once Aβ enters the cell, it is the disordered part (only when it is connected to the rest of the peptide) that has a strong and stereospecific interaction with an unknown cellular component, as demonstrated by distinct changes in the fluorescence lifetime of a fluorophore attached to the N-terminal. This interaction appears to commit Aβ to the toxic pathway. Our findings correlate well with Aβ sites of familial AD mutations, a significant fraction of which cluster in the disordered region. We conclude that, while the ordered region dictates attachment and cellular entry, the key to toxicity lies in the ordered part presenting the disordered part for a specific cellular interaction.
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Affiliation(s)
- Barun Kumar Maity
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Anand Kant Das
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Simli Dey
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | | | | | - Arpan Dey
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Dayana Surendran
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Rucha Pandit
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Mamata Kallianpur
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Bappaditya Chandra
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Muralidharan Chandrakesan
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | | | - Sudipta Maiti
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
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12
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Singh J, Peric M. Interaction of the β amyloid - Aβ(25-35) - peptide with zwitterionic and negatively charged vesicles with and without cholesterol. Chem Phys Lipids 2018; 216:39-47. [PMID: 30222975 DOI: 10.1016/j.chemphyslip.2018.09.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 12/11/2022]
Abstract
The interactions of the Alzheimer's β-amyloid peptide, Aβ(25-35), with 18:1 (Δ9-Cis) PC 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), L-α-phosphatidylcholine (EPC), 1,2-dioleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) (DOPG), and L-α-phosphatidylglycerol (EPG) phospholipid vesicles with and without cholesterol (Ch) are studied by the nitroxide spin probe electron paramagnetic resonance (EPR) method. Two nitroxide spin probes, 2,2,6,6-tetramethyl-piperidin-1-oxyl-4-yl hexadecanoate (TP, TEMPO-Palmitate) and 2-Ethyl-2-(15-methoxy-15-oxopentadecyl)-4,4-dimethyl-3-oxazolidinyloxy (16-DSE), are utilized in the study. TEMPO-Palmitate has the reporting EPR moiety located at the top of this spin probe, while 16-DSE has the reporting EPR moiety located at the tail of the spin probe. These two probes enable us to sample the surface and the middle of the phospholipid bilayer, respectively. All EPR measurements are done above the melting points of all four phospholipids when the bilayer is in the liquid crystal phase, the physiologically relevant phase. Due to non-linear spectral line fitting, the EPR spectral parameters are extracted with high precision. The results show that there are two populations of Aβ(25-35) and that one of them is located in the hydrophobic phospholipid layer below the hydrophilic headgroup region. The second population appears to be weakly coupled to the surface of the bilayer. Both hydrophobic and electrostatic interactions affect the insertion of Aβ(25-35) in the bilayer. Also, there is strong evidence for an interaction between cholesterol and Aβ(25-35), which affects the dielectric and dynamic properties of the bilayer.
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Affiliation(s)
- Jasmeet Singh
- Department of Physics and Astronomy and The Center for Supramolecular Studies, California State University at Northridge, Northridge, California 91330, United States
| | - Miroslav Peric
- Department of Physics and Astronomy and The Center for Supramolecular Studies, California State University at Northridge, Northridge, California 91330, United States.
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Khondker A, Alsop RJ, Himbert S, Tang J, Shi AC, Hitchcock AP, Rheinstädter MC. Membrane-Modulating Drugs can Affect the Size of Amyloid-β 25-35 Aggregates in Anionic Membranes. Sci Rep 2018; 8:12367. [PMID: 30120270 PMCID: PMC6098001 DOI: 10.1038/s41598-018-30431-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/30/2018] [Indexed: 01/08/2023] Open
Abstract
The formation of amyloid-β plaques is one of the hallmarks of Alzheimer's disease. The presence of an amphiphatic cell membrane can accelerate the formation of amyloid-β aggregates, making it a potential druggable target to delay the progression of Alzheimer's disease. We have prepared unsaturated anionic membranes made of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (DMPS) and added the trans-membrane segment Aβ25-35. Peptide plaques spontaneously form in these membranes at high peptide concentrations of 20 mol%, which show the characteristic cross-β motif (concentrations are relative to the number of membrane lipids and indicate the peptide-to-lipid ratio). We used atomic force microscopy, fluorescence microscopy, x-ray microscopy, x-ray diffraction, UV-vis spectroscopy and Molecular Dynamics (MD) simulations to study three membrane-active molecules which have been speculated to have an effect in Alzheimer's disease: melatonin, acetylsalicyclic acid (ASA) and curcumin at concentrations of 5 mol% (drug-to-peptide ratio). Melatonin did not change the structural parameters of the membranes and did not impact the size or extent of peptide clusters. While ASA led to a membrane thickening and stiffening, curcumin made membranes softer and thinner. As a result, ASA was found to lead to the formation of larger peptide aggregates, whereas curcumin reduced the volume fraction of cross-β sheets by ~70%. We speculate that the interface between membrane and peptide cluster becomes less favorable in thick and stiff membranes, which favors the formation of larger aggregates, while the corresponding energy mismatch is reduced in soft and thin membranes. Our results present evidence that cross-β sheets of Aβ25-35 in anionic unsaturated lipid membranes can be re-dissolved by changing membrane properties to reduce domain mismatch.
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Affiliation(s)
- Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Richard J Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Jennifer Tang
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - An-Chang Shi
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Adam P Hitchcock
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada. .,Origins Institute, McMaster University, Hamilton, Ontario, Canada.
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14
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Tanqueiro SR, Ramalho RM, Rodrigues TM, Lopes LV, Sebastião AM, Diógenes MJ. Inhibition of NMDA Receptors Prevents the Loss of BDNF Function Induced by Amyloid β. Front Pharmacol 2018; 9:237. [PMID: 29695962 PMCID: PMC5904251 DOI: 10.3389/fphar.2018.00237] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 03/02/2018] [Indexed: 01/18/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) plays important functions in cell survival and differentiation, neuronal outgrowth and plasticity. In Alzheimer’s disease (AD), BDNF signaling is known to be impaired, partially because amyloid β (Aβ) induces truncation of BDNF main receptor, TrkB-full length (TrkB-FL). We have previously shown that such truncation is mediated by calpains, results in the formation of an intracellular domain (ICD) fragment and causes BDNF loss of function. Since calpains are Ca2+-dependent proteases, we hypothesized that excessive intracellular Ca2+ build-up could be due to dysfunctional N-methyl-d-aspartate receptors (NMDARs) activation. To experimentally address this hypothesis, we investigated whether TrkB-FL truncation by calpains and consequent BDNF loss of function could be prevented by NMDAR blockade. We herein demonstrate that a NMDAR antagonist, memantine, prevented excessive calpain activation and TrkB-FL truncation induced by Aβ25–35. When calpains were inhibited by calpastatin, BDNF was able to increase the dendritic spine density of neurons exposed to Aβ25135. Moreover, NMDAR inhibition by memantine also prevented Aβ-driven deleterious impact of BDNF loss of function on structural (spine density) and functional outcomes (synaptic potentiation). Collectively, these findings support NMDAR/Ca2+/calpains mechanistic involvement in Aβ-triggered BDNF signaling disruption.
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Affiliation(s)
- Sara R Tanqueiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Rita M Ramalho
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Tiago M Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Luísa V Lopes
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Maria J Diógenes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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15
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Membrane-Accelerated Amyloid-β Aggregation and Formation of Cross-β Sheets. MEMBRANES 2017; 7:membranes7030049. [PMID: 28858214 PMCID: PMC5618134 DOI: 10.3390/membranes7030049] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/26/2017] [Accepted: 08/23/2017] [Indexed: 11/17/2022]
Abstract
Amyloid- β aggregates play a causative role in Alzheimer's disease. These aggregates are a product of the physical environment provided by the basic neuronal membrane, composed of a lipid bilayer. The intrinsic properties of the lipid bilayer allow amyloid- β peptides to nucleate and form well-ordered cross- β sheets within the membrane. Here, we correlate the aggregation of the hydrophobic fragment of the amyloid- β protein, A β 25 - 35 , with the hydrophobicity, fluidity, and charge density of a lipid bilayer. We summarize recent biophysical studies of model membranes and relate these to the process of aggregation in physiological systems.
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16
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Lockhart C, Klimov DK. The Alzheimer's disease A β peptide binds to the anionic DMPS lipid bilayer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1118-28. [DOI: 10.1016/j.bbamem.2016.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 02/26/2016] [Accepted: 03/01/2016] [Indexed: 11/24/2022]
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17
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Cuco A, Serro AP, Farinha JP, Saramago B, da Silva AG. Interaction of the Alzheimer Aβ(25–35) peptide segment with model membranes. Colloids Surf B Biointerfaces 2016; 141:10-18. [DOI: 10.1016/j.colsurfb.2016.01.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/04/2016] [Accepted: 01/06/2016] [Indexed: 11/15/2022]
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18
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Tang J, Alsop RJ, Backholm M, Dies H, Shi AC, Rheinstädter MC. Amyloid-β(25-35) peptides aggregate into cross-β sheets in unsaturated anionic lipid membranes at high peptide concentrations. SOFT MATTER 2016; 12:3165-3176. [PMID: 26934592 DOI: 10.1039/c5sm02619a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
One of the hallmarks of Alzheimer's disease is the formation of protein plaques in the brain, which mainly consist of amyloid-β peptides of different lengths. While the role of these plaques in the pathology of the disease is not clear, the mechanism behind peptide aggregation is a topic of intense research and discussion. Because of their simplicity, synthetic membranes are promising model systems to identify the elementary processes involved. We prepared unsaturated zwitterionic/anionic lipid membranes made of 1-palmitoyl-2-oleoyl-sn-glycero-phosphocholine (POPC) and 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine (DMPS) at concentrations of POPC/3 mol% DMPS containing 0 mol%, 3 mol%, 10 mol%, and 20 mol% amyloid-β25-35 peptides. Membrane-embedded peptide clusters were observed at peptide concentrations of 10 and 20 mol% with a typical cluster size of ∼11 μm. Cluster density increased with peptide concentration from 59 (±3) clusters per mm(2) to 920 (±64) clusters per mm(2), respectively. While monomeric peptides take an α-helical state when embedded in lipid bilayers at low peptide concentrations, the peptides in peptide clusters were found to form cross-β sheets and showed the characteristic pattern in X-ray experiments. The presence of the peptides was accompanied by an elastic distortion of the bilayers, which can induce a long range interaction between the peptides. The experimentally observed cluster patterns agree well with Monte Carlo simulations of long-range interacting peptides. This interaction may be the fundamental process behind cross-β sheet formation in membranes and these sheets may serve as seeds for further growth into amyloid fibrils.
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Affiliation(s)
- Jennifer Tang
- Department of Physics and Astronomy, McMaster University, ABB-241, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
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19
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Bag S, Sett A, DasGupta S, Dasgupta S. Hydropathy: the controlling factor behind the inhibition of Aβ fibrillation by graphene oxide. RSC Adv 2016. [DOI: 10.1039/c6ra23570k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Fibrillation of Aβ25–35 peptide is inhibited in presence of graphene oxide.
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Affiliation(s)
- Sudipta Bag
- Department of Chemistry
- Indian Institute of Technology Kharagpur
- Kharagpur 721302
- India
| | - Ayantika Sett
- Department of Chemical Engineering
- Indian Institute of Technology Kharagpur
- Kharagpur 721302
- India
| | - Sunando DasGupta
- Department of Chemical Engineering
- Indian Institute of Technology Kharagpur
- Kharagpur 721302
- India
| | - Swagata Dasgupta
- Department of Chemistry
- Indian Institute of Technology Kharagpur
- Kharagpur 721302
- India
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20
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Barrett MA, Alsop RJ, Hauß T, Rheinstädter MC. The Position of Aβ22-40 and Aβ1-42 in Anionic Lipid Membranes Containing Cholesterol. MEMBRANES 2015; 5:824-43. [PMID: 26633529 PMCID: PMC4704014 DOI: 10.3390/membranes5040824] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/25/2015] [Indexed: 02/07/2023]
Abstract
Amyloid-β peptides interact with cell membranes in the human brain and are associated with neurodegenerative diseases, such as Alzheimer's disease. An emerging explanation of the molecular mechanism, which results in neurodegeneration, places the cause of neurotoxicity of the amyloid- peptides on their potentially negative interaction with neuronal membranes. It is known that amyloid-β peptides interact with the membrane, modifying the membrane's structural and dynamic properties. We present a series of X-ray diffraction experiments on anionic model lipid membranes containing various amounts of cholesterol. These experiments provide experimental evidence for an interaction of both the full length amyloid-β1-42 peptide, and the peptide fragment amyloid-β22-40 with anionic bilayer containing cholesterol. The location of the amyloid-β peptides was determined from these experiments, with the full length peptide embedding into the membrane, and the peptide fragment occupying 2 positions-on the membrane surface and embedded into the membrane core.
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Affiliation(s)
- Matthew A Barrett
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Lise-Meitner-Campus, Berlin, Germany.
| | - Richard J Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada.
| | - Thomas Hauß
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Lise-Meitner-Campus, Berlin, Germany.
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada.
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21
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Interfacial force-driven pattern formation during drying of Aβ (25–35) fibrils. Int J Biol Macromol 2015; 79:344-52. [DOI: 10.1016/j.ijbiomac.2015.04.074] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 04/27/2015] [Accepted: 04/28/2015] [Indexed: 11/21/2022]
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22
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TREM2 lipid sensing sustains the microglial response in an Alzheimer's disease model. Cell 2015; 160:1061-71. [PMID: 25728668 PMCID: PMC4477963 DOI: 10.1016/j.cell.2015.01.049] [Citation(s) in RCA: 1116] [Impact Index Per Article: 124.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 12/11/2014] [Accepted: 01/26/2015] [Indexed: 11/24/2022]
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglia surface receptor that triggers intracellular protein tyrosine phosphorylation. Recent genome-wide association studies have shown that a rare R47H mutation of TREM2 correlates with a substantial increase in the risk of developing Alzheimer's disease (AD). To address the basis for this genetic association, we studied TREM2 deficiency in the 5XFAD mouse model of AD. We found that TREM2 deficiency and haploinsufficiency augment β-amyloid (Aβ) accumulation due to dysfunctional response of microglia, which become apoptotic and fail to cluster around Aβ plaques. We further demonstrate that TREM2 senses a broad array of anionic and zwitterionic lipids known to associate with fibrillar Aβ in lipid membranes and to be exposed on the surface of damaged neurons. Remarkably, the R47H mutation impairs TREM2 detection of lipid ligands. Thus, TREM2 detects damage-associated lipid patterns associated with neurodegeneration, sustaining microglia response to Aβ accumulation.
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23
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Egea-Jiménez AL, Corbalán-García S, Gómez-Fernández JC. The C1B domains of novel PKCε and PKCη have a higher membrane binding affinity than those of the also novel PKCδ and PKCθ. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1898-909. [DOI: 10.1016/j.bbamem.2014.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/28/2014] [Accepted: 04/02/2014] [Indexed: 10/25/2022]
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Dies H, Toppozini L, Rheinstädter MC. The interaction between amyloid-β peptides and anionic lipid membranes containing cholesterol and melatonin. PLoS One 2014; 9:e99124. [PMID: 24915524 PMCID: PMC4051683 DOI: 10.1371/journal.pone.0099124] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 05/11/2014] [Indexed: 12/21/2022] Open
Abstract
One of the hallmarks of Alzheimer's disease is the formation of senile plaques, primarily consisting of amyloid- (A) peptides. Peptide-membrane and peptide-lipid interactions are thought to be crucial in this process. We studied the interaction of A and A peptides with anionic lipid membranes made of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphoserine (DMPS) using X-ray diffraction. We compare the experimentally determined electron densities in the gel state of the membranes with density calculations from peptide structures reported in the Protein Data Bank in order to determine the position of the peptide in the bilayers. The full length peptide A was found to embed in the hydrocarbon core of the anionic lipid bilayers. Two populations were found for the A peptide: (1) membrane-bound states in the hydrophilic head group region of the bilayers, where the peptides align parallel to the membranes, and (2) an embedded state in the bilayer center. Aging plays an important role in the development of Alzheimer's, in particular with respect to changes in cholesterol and melatonin levels in the brain tissue. Immiscible cholesterol plaques were created by addition of 30 mol% cholesterol to the anionic membranes. The A peptides were found to strongly interact with the lipid bilayers, displacing further cholesterol molecules into the plaques, effectively lowering the cholesterol concentration in the membranes and increasing the total fraction of cholesterol plaques. Addition of 30 mol% melatonin molecules to the anionic membranes drastically reduced the population of the membrane-embedded A state. These results present experimental evidence for an interaction between A peptides, melatonin and cholesterol in lipid membranes.
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Affiliation(s)
- Hannah Dies
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Laura Toppozini
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
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25
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Zhang HY, Yamakawa YI, Matsuya Y, Toyooka N, Tohda C, Awale S, Li F, Kadota S, Tezuka Y. Synthesis of long-chain fatty acid derivatives as a novel anti-Alzheimer's agent. Bioorg Med Chem Lett 2013; 24:604-8. [PMID: 24360558 DOI: 10.1016/j.bmcl.2013.12.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 11/20/2013] [Accepted: 12/02/2013] [Indexed: 11/29/2022]
Abstract
In order to develop new drugs for Alzheimer's disease, we prepared 17 fatty acid derivatives with different chain lengths and different numbers and positions of double bonds by using Wittig reaction and stereospecific hydrogenation of triple bonds as key reactions. Among them, (4Z,15Z)-octadecadienoic acid (10) and (23Z,34Z)-heptatriacontadienoic acid (16) showed the most potent neurite outgrowth activities on Aβ(25-35)-treated rat cortical neurons, which activities were comparable to that of a positive control, NGF. Both fatty acids 10 and 16 possess two (Z)-double bonds at the n-3 and n-14 positions, which might be important for the neurite outgrowth activity.
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Affiliation(s)
- Hong-Yan Zhang
- Division of Natural Products Chemistry, Institute of Natural Medicine, University of Toyama, Sugitani 2630, Toyama 930-0194, Japan
| | - Yu-ichiro Yamakawa
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani 2630, Toyama 930-0194, Japan
| | - Yuji Matsuya
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani 2630, Toyama 930-0194, Japan
| | - Naoki Toyooka
- Graduate School of Science and Technology for Research, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan; Graduate School of Innovative Life Science, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan.
| | - Chihiro Tohda
- Division of Division of Neuromedical Science, Institute of Natural Medicine, University of Toyama, Sugitani 2630, Toyama 930-0194, Japan
| | - Suresh Awale
- Frontier Research Core for Life Sciences, University of Toyama, Sugitani 2630, Toyama 930-0194, Japan
| | - Feng Li
- Research Promotion Office, Joint Usage/Research Center for Science-Based Natural Medicine, Institute of Natural Medicine, University of Toyama, Sugitani 2630, Toyama 930-0194, Japan
| | - Shigetoshi Kadota
- Division of Natural Products Chemistry, Institute of Natural Medicine, University of Toyama, Sugitani 2630, Toyama 930-0194, Japan
| | - Yasuhiro Tezuka
- Division of Natural Products Chemistry, Institute of Natural Medicine, University of Toyama, Sugitani 2630, Toyama 930-0194, Japan.
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26
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Labbé JF, Lefèvre T, Guay-Bégin AA, Auger M. Structure and membrane interactions of the β-amyloid fragment 25-35 as viewed using spectroscopic approaches. Phys Chem Chem Phys 2013; 15:7228-39. [PMID: 23572139 DOI: 10.1039/c3cp44623a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The β-amyloid fragment peptide 25-35 (Aβ(25-35)) is recognized as the cytotoxic sequence of the parent peptide Aβ. However, it remains unclear whether its neurotoxicity originates from its fibrillar form, how it interacts with lipid membranes, and whether cholesterol modulates these interactions. These questions have been addressed at a molecular level using various microscopic and spectroscopic techniques. The data show that Aβ(25-35) forms protofilaments at pH 7.4 at a concentration of 5 mM in the absence and presence of DMPC/DMPG model membranes. The peptide adopts a predominant aggregated β-sheet conformation under these conditions. However, as the peptide concentration decreases, the β-sheet structure tends to disappear for the benefit of β-turns, suggesting that the peptide association is reversible. The β-sheet structure formed by Aβ(25-35) appears to be atypical and characterized by the absence of intermolecular dipolar coupling and by a parallel strand configuration. The data show that Aβ(25-35)-phospholipid interactions are characterized by an increase in the conformational order of the lipid acyl chains and a change in the fluidity/elasticity of the bilayers. Concomitantly, the peptide seems to lose a few β-sheet structures, which suggests that the interactions between Aβ(25-35) and DMPC/DMPG membranes are partly driven by peptide concentration. Interactions indeed seem to occur when part of the peptides is not involved in protofilaments and increase as the proportion of the free peptide species increases. The interactions are very similar in the presence of cholesterol, except that the concentration effect of Aβ(25-35) is cancelled, suggesting that Chol limits the penetration of the peptide inside the bilayers.
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Affiliation(s)
- Jean-François Labbé
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Université Laval, Québec, Québec, Canada
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27
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Bernal-Mondragón C, Rivas-Arancibia S, Kendrick KM, Guevara-Guzmán R. Estradiol prevents olfactory dysfunction induced by A-β 25-35 injection in hippocampus. BMC Neurosci 2013; 14:104. [PMID: 24059981 PMCID: PMC3849069 DOI: 10.1186/1471-2202-14-104] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 09/19/2013] [Indexed: 01/09/2023] Open
Abstract
Background Some neurodegenerative diseases, such as Alzheimer and Parkinson, present an olfactory impairment in early stages, and sometimes even before the clinical symptoms begin. In this study, we assess the role of CA1 hippocampus (structure highly affected in Alzheimer disease) subfield in the rats’ olfactory behavior, and the neuroprotective effect of 17 beta estradiol (E2) against the oxidative stress produced by the injection of amyloid beta 25–35. Results 162 Wistar rats were ovariectomized and two weeks after injected with 2 μl of amyloid beta 25–35 (A-β25–35) in CA1 subfield. Olfactory behavior was evaluated with a social recognition test, odor discrimination, and search tests. Oxidative stress was evaluated with FOX assay and Western Blot against 4-HNE, Fluoro Jade staining was made to quantify degenerated neurons; all these evaluations were performed 24 h, 8 or 15 days after A-β25–35 injection. Three additional groups treated with 17 beta estradiol (E2) were also evaluated. The injection of A-β25–35 produced an olfactory impairment 24 h and 8 days after, whereas a partial recovery of the olfactory behavior was observed at 15 days. A complete prevention of the olfactory impairment was observed with the administration of E2 two weeks before the amyloid injection (A-β25–35 24 h + E2) and one or two weeks after (groups 8 A-β +E2 and 15 A-β +E2 days, respectively); a decrease of the oxidative stress and neurodegeneration were also observed. Conclusions Our finding shows that CA1 hippocampus subfield plays an important role in the olfactory behavior of the rat. The oxidative stress generated by the administration of A-β25–35 is enough to produce an olfactory impairment. This can be prevented with the administration of E2 before and after amyloid injection. This suggests a possible therapeutic use of estradiol in Alzheimer’s disease.
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Affiliation(s)
- Carlos Bernal-Mondragón
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Apdo, Postal 70250, D,F, México, Delegación Coyoacán 04510, Mexico.
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Gal N, Morag A, Kolusheva S, Winter R, Landau M, Jelinek R. Lipid Bilayers Significantly Modulate Cross-Fibrillation of Two Distinct Amyloidogenic Peptides. J Am Chem Soc 2013; 135:13582-9. [DOI: 10.1021/ja4070427] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Noga Gal
- Department
of Chemistry, Ben Gurion University of the Negev, Beer Sheva, Israel 84105
| | - Ahiud Morag
- Department
of Chemistry, Ben Gurion University of the Negev, Beer Sheva, Israel 84105
| | - Sofiya Kolusheva
- Ilse
Katz Institute for Nanotechnology, Ben Gurion University Beer Sheva, Israel 84105
| | - Roland Winter
- Technische Universität Dortmund Physikalische Chemie − Biophysikalische Chemie, Otto-Hahn-Straße
6, 44227 Dortmund, Germany
| | - Meytal Landau
- Department
of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Raz Jelinek
- Department
of Chemistry, Ben Gurion University of the Negev, Beer Sheva, Israel 84105
- Ilse
Katz Institute for Nanotechnology, Ben Gurion University Beer Sheva, Israel 84105
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29
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Yu X, Wang Q, Pan Q, Zhou F, Zheng J. Molecular interactions of Alzheimer amyloid-β oligomers with neutral and negatively charged lipid bilayers. Phys Chem Chem Phys 2013; 15:8878-89. [PMID: 23493873 DOI: 10.1039/c3cp44448a] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Interaction of p3 (Aβ(17-42)) peptides with cell membranes is crucial for the understanding of amyloid toxicity associated with Alzheimer's disease (AD). Such p3-membrane interactions are considered to induce the disruption of membrane permeability and integrity, but the exact mechanisms of how p3 aggregates, particularly small p3 oligomers, induce receptor-independent membrane disruption are not yet completely understood. Here, we investigate the adsorption, orientation, and surface interaction of the p3 pentamer with lipid bilayers composed of both pure zwitterionic POPC (palmitoyl-oleoyl-phosphatidylcholine) and mixed anionic POPC-POPG (palmitoyl-oleoyl-phosphatidylglycerol) (3 : 1) lipids using explicit-solvent molecular dynamics (MD) simulations. MD simulation results show that the p3 pentamer has much stronger interactions with mixed POPC-POPG lipids than pure POPC lipids, consistent with experimental observation that Aβ adsorption and fibrillation are enhanced on anionic lipid bilayers. Although electrostatic interactions are main attractive forces to drive the p3 pentamer to adsorb on the bilayer surface, the adsorption of the p3 pentamer on the lipid bilayer with C-terminal β-strands facing toward the bilayer surface is a net outcome of different competitions between p3 peptides-lipid bilayer and ions-p3-bilayer interactions. More importantly, Ca(2+) ions are found to form ionic bridges to associate negatively charged residues of p3 with anionic headgroups of the lipid bilayer, resulting in Aβ-Ca(2+)-PO4(-) complexes. Intensive Ca(2+) bound to the lipid bilayer and Ca(2+) ionic bridges may lead to Ca(2+) hemostasis responsible for neuronal dysfunction and death. This work provides insights into the mutual structure, dynamics, and interactions of both Aβ peptides and lipid bilayers at the atomic level, which expand our understanding of the complex behavior of amyloid-induced membrane disruption.
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Affiliation(s)
- Xiang Yu
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, USA
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30
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Guo C, Dugas T, Scates C, Garcia-Villarreal M, Ticich T, McMartin KE. Aluminum citrate blocks toxicity of calcium oxalate crystals by preventing binding with cell membrane phospholipids. Am J Nephrol 2013; 37:41-9. [PMID: 23295956 DOI: 10.1159/000345985] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 11/21/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Renal damage from ethylene glycol and primary hyperoxaluria is linked to accumulation of calcium oxalate monohydrate (COM) crystals in the renal proximal tubule (PT). In vitro studies have shown that aluminum citrate (AC), uniquely among citrate salts, blocks COM cytotoxicity to tubular cells. These studies were designed to evaluate the interaction of COM with membrane phospholipids and the ability of AC to reduce COM toxicity by interfering with this interaction. METHODS Interaction of COM with phospholipids was assessed using differential scanning calorimetric analysis of structural changes in specific liposomes. Interaction of COM with cell membranes was studied by measuring binding of radiolabeled crystals by human PT (HPT) cells. RESULTS Analysis of liposomes prepared from phosphatidylserine (PS) or phosphatidylcholine (PC) showed that COM interfered with the gel-liquid transition of PS liposomes, but not that of PC liposomes. AC reversed the COM-induced changes in liposomal structure. AC inhibited the binding of [(14)C]-COM by HPT cells in a concentration-dependent manner. AC blocked COM binding by interacting with the crystal surface and not the cell membrane. CONCLUSION These results indicate that AC blocks the binding of COM by PT cells, and consequently its cytotoxicity, by attaching to the surface of the crystal. Thus, AC, or a related compound that works by the same mechanism, could be a useful adjunct therapy to reduce the renal damage produced by severe hyperoxaluria.
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Affiliation(s)
- Chungang Guo
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA 71130-3932, USA
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31
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Ding H, Schauerte JA, Steel DG, Gafni A. β-Amyloid (1-40) peptide interactions with supported phospholipid membranes: a single-molecule study. Biophys J 2012; 103:1500-9. [PMID: 23062342 DOI: 10.1016/j.bpj.2012.08.051] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Revised: 08/26/2012] [Accepted: 08/29/2012] [Indexed: 02/07/2023] Open
Abstract
Recent evidence supports the hypothesis that the oligomers formed by the β-amyloid peptide early in its aggregation process are neurotoxic and may feature in Alzheimer's disease. Although the mechanism underlying this neurotoxicity remains unclear, interactions of these oligomers with neuronal membranes are believed to be involved. Identifying the neurotoxic species is challenging because β-amyloid peptides form oligomers at very low physiological concentrations (nM), and these oligomers are highly heterogeneous and metastable. Here, we report the use of single-molecule imaging techniques to study the interactions between β-amyloid (1-40) peptides and supported synthetic model anionic lipid membranes. The evolution of the β-amyloid species on the membranes was monitored for up to several days, and the results indicate an initial tight, uniform, binding of β-amyloid (1-40) peptides to the lipid membranes, followed by oligomer formation in the membrane. At these low concentrations, the behavior at early times during the formation of small oligomers is interpreted qualitatively in terms of the two-state model proposed by H. W. Huang for the interaction between amphipathic peptides and membranes. However, the rate of oligomer formation in the membrane and their size are highly dependent on the concentrations of β-amyloid (1-40) peptides in aqueous solution, suggesting two different pathways of oligomer formation, which lead to drastically different species in the membrane and a departure from the two-state model as the concentration increases.
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Affiliation(s)
- Hao Ding
- Department of Biophysics, University of Michigan, Ann Arbor, MI, USA
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32
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Catricala S, Torti M, Ricevuti G. Alzheimer disease and platelets: how's that relevant. IMMUNITY & AGEING 2012; 9:20. [PMID: 22985434 PMCID: PMC3545835 DOI: 10.1186/1742-4933-9-20] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 08/01/2012] [Indexed: 02/06/2023]
Abstract
Alzheimer Disease (AD) is the most common neurodegenerative disorder worldwide, and account for 60% to 70% of all cases of progressive cognitive impairment in elderly patients. At the microscopic level distinctive features of AD are neurons and synapses degeneration, together with extensive amounts of senile plaques and neurofibrillars tangles. The degenerative process probably starts 20-30 years before the clinical onset of the disease. Senile plaques are composed of a central core of amyloid β peptide, Aβ, derived from the metabolism of the larger amyloid precursor protein, APP, which is expressed not only in the brain, but even in non neuronal tissues. More than 30 years ago, some studies reported that human platelets express APP and all the enzymatic activities necessary to process this protein through the same pathways described in the brain. Since then a large number of evidence has been accumulated to suggest that platelets may be a good peripheral model to study the metabolism of APP, and the pathophysiology of the onset of AD. In this review, we will summarize the current knowledge on the involvement of platelets in Alzheimer Disease. Although platelets are generally accepted as a suitable model for AD, the current scientific interest on this model is very high, because many concepts still remain debated and controversial. At the same time, however, these still unsolved divergences mirror a difficulty to establish constant parameters to better defined the role of platelets in AD.
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Affiliation(s)
- Silvia Catricala
- Department of Internal Medicine and Therapeutics, Section of Geriatrics, University of Pavia, ASP-IDR S,Margherita, Via Emilia 12, Pavia, 27100, Italy.
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33
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Joshi N, Páez X, Araque H. Electroacupuncture Effects on the Disintegration of Beta Amyloid Sheets: Its Application to Alzheimer's Disease. Med Acupunct 2012. [DOI: 10.1089/acu.2012.0873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Narahari Joshi
- Department of Physiology, Universidad de los Andes, Mérida, Venezuela
| | - Ximena Páez
- Laboratory of Behavioral Physiology, School of Medicine, Universidad de los Andes, Mérida, Venezuela
| | - Haydeé Araque
- Programa Integral de Salud Maturitas Academiae (PRISMA), Universidad de los Andes, Mérida, Venezuela
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34
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Shanmugam G, Polavarapu PL. Site-specific structure of Aβ(25-35) peptide: isotope-assisted vibrational circular dichroism study. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1834:308-16. [PMID: 22910376 DOI: 10.1016/j.bbapap.2012.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Revised: 08/02/2012] [Accepted: 08/07/2012] [Indexed: 11/17/2022]
Abstract
We investigated the site-specific local structure of an amyloid peptide, NH(2)-GSNKGAIIGLM-COOH [Aβ(25-35)], one of the active fragments of amyloid β peptide that is known to be responsible for Alzheimer's disease, in the fibrillar aggregated state. Isotope-assisted infrared vibrational circular dichroism (VCD) and absorption (VA) spectroscopy were used for the parent Aβ(25-35) peptide, along with doubly (13)C labeled peptides at the carbonyl groups of residues 29 (Gly) and 30 (Ala) [Aβ(25-35:(13)C-29/30)] and at the carbonyl groups of residues 33 (Gly) and 34 (Leu) [Aβ(25-35:(13)C-33/34)]. The present results confirm that Aβ(25-35) peptide fibrils adopt a β-sheet structure and isotopic dilution experiments suggest a parallel β-sheet structure. The isotopic shifts suggest that the microenvironment of residues 29 (Gly) and 30 (Ala) could be different from that of residues 33 (Gly) and 34 (Leu). An unusual enhancement for the amide II' VCD intensities of Aβ(25-35:(13)C-29/30) and Aβ(25-35:(13)C-33/34) peptide fibrils, considered to originate from inter-strand coupling, was found for the first time. The structural information reported in this manuscript has important implications in understanding the role of this peptide in the development of Alzheimer's disease.
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Affiliation(s)
- Ganesh Shanmugam
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
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35
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Tauroursodeoxycholic acid suppresses amyloid β-induced synaptic toxicity in vitro and in APP/PS1 mice. Neurobiol Aging 2012; 34:551-61. [PMID: 22621777 DOI: 10.1016/j.neurobiolaging.2012.04.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 04/20/2012] [Accepted: 04/28/2012] [Indexed: 02/06/2023]
Abstract
Synapses are considered the earliest site of Alzheimer's disease (AD) pathology, where synapse density is reduced, and synaptic loss is highly correlated with cognitive impairment. Tauroursodeoxycholic acid (TUDCA) has been shown to be neuroprotective in several models of AD, including neuronal exposure to amyloid β (Aβ) and amyloid precursor protein (APP)/presenilin 1 (PS1) double-transgenic mice. Here, we show that TUDCA modulates synaptic deficits induced by Aβ in vitro. Specifically, TUDCA reduced the downregulation of the postsynaptic marker postsynaptic density-95 (PSD-95) and the decrease in spontaneous miniature excitatory postsynaptic currents (mEPSCs) frequency, while increasing the number of dendritic spines. This contributed to the induction of more robust and synaptically efficient neurons, reflected in inhibition of neuronal death. In vivo, TUDCA treatment of APP/PS1 mice abrogated the decrease in PSD-95 reactivity in the hippocampus. Taken together, these results expand the neuroprotective role of TUDCA to a synaptic level, further supporting the use of this molecule as a potential therapeutic strategy for the prevention and treatment of AD.
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36
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Croce N, Ciotti MT, Gelfo F, Cortelli S, Federici G, Caltagirone C, Bernardini S, Angelucci F. Neuropeptide Y protects rat cortical neurons against β-amyloid toxicity and re-establishes synthesis and release of nerve growth factor. ACS Chem Neurosci 2012; 3:312-8. [PMID: 22860197 DOI: 10.1021/cn200127e] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 01/16/2012] [Indexed: 02/03/2023] Open
Abstract
Neuropeptide Y (NPY) is a 36 amino acid peptide, widely distributed within central nervous system neurons. More recently, it has been shown that NPY is involved in Alzheimer's disease (AD), a disorder characterized by accumulation of amyloid β-peptide (Aβ) in neurons. In a previous study, we investigated the effect of NPY on neuronal damage by exposing SH-SY5Y cells (an established human derived neuroblastoma cell line) to Aβ's pathogenic fragment 25-35 (Aβ(25-35)). We found a NPY-neuroprotective action associated with changes in intracellular production of nerve growth factor (NGF), a member of the neurotrophin family. Since our results were encouraging, we decided to replicate our data using primary cortical neurons cultured in presence of Aβ(25-35), and investigated whether NPY had similar neuroprotective action. Moreover, since cortical neurons are able to produce and release NGF, we investigated whether the synthesis and release of NGF were modified in such experimental conditions. Our results showed that a preincubation with NPY counteracted the toxic effect of Aβ, as measured by increased cell viability. Moreover, NPY pretreatment had an effect on NGF since its intracellular synthesis was increased, release was normalized, and mRNA expression was downregulated. Notably, these effects on NGF were in the opposite direction of those produced by incubating the cells with Aβ alone. This study in primary cortical neurons supports the hypothesis that NPY may be a neuroprotective agent against β-amyloid neurotoxicity. These data also suggest that NPY may influence the synthesis and the release of NGF by cortical neurons.
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Affiliation(s)
| | - Maria Teresa Ciotti
- Institute of Cellular Biology
and Neurobiology, National Council of Research, Rome, Italy
| | | | - Silvia Cortelli
- Department
of Internal Medicine, Tor Vergata University, Rome, Italy
| | - Giorgio Federici
- Department
of Internal Medicine, Tor Vergata University, Rome, Italy
| | | | - Sergio Bernardini
- Department
of Internal Medicine, Tor Vergata University, Rome, Italy
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37
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Betaneli V, Petrov EP, Schwille P. The role of lipids in VDAC oligomerization. Biophys J 2012; 102:523-31. [PMID: 22325275 DOI: 10.1016/j.bpj.2011.12.049] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 12/16/2011] [Accepted: 12/22/2011] [Indexed: 10/14/2022] Open
Abstract
Evidence has accumulated that the voltage-dependent anion channel (VDAC), located on the outer membrane of mitochondria, plays a central role in apoptosis. The involvement of VDAC oligomerization in apoptosis has been suggested in various studies. However, it still remains unknown how exactly VDAC supramolecular assembly can be regulated in the membrane. This study addresses the role of lipids in this process. We investigate the effect of cardiolipin (CL) and phosphatidylglycerol (PG), anionic lipids important for mitochondria metabolism and apoptosis, on VDAC oligomerization. By applying fluorescence cross-correlation spectroscopy to VDAC reconstituted into giant unilamellar vesicles, we demonstrate that PG significantly enhances VDAC oligomerization in the membrane, whereas cardiolipin disrupts VDAC supramolecular assemblies. During apoptosis, the level of PG in mitochondria increases, whereas the CL level decreases. We suggest that the specific lipid composition of the outer mitochondrial membrane might be of crucial relevance and, thus, a potential cue for regulating the oligomeric state of VDAC.
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Affiliation(s)
- Viktoria Betaneli
- Biophysics, BIOTEC, Technische Universität Dresden, Dresden, Germany
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38
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Cardinale A, Racaniello M, Saladini S, De Chiara G, Mollinari C, de Stefano MC, Pocchiari M, Garaci E, Merlo D. Sublethal doses of β-amyloid peptide abrogate DNA-dependent protein kinase activity. J Biol Chem 2011; 287:2618-31. [PMID: 22139836 DOI: 10.1074/jbc.m111.276550] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Accumulation of DNA damage and deficiency in DNA repair potentially contribute to the progressive neuronal loss in neurodegenerative disorders, including Alzheimer disease (AD). In multicellular eukaryotes, double strand breaks (DSBs), the most lethal form of DNA damage, are mainly repaired by the nonhomologous end joining pathway, which relies on DNA-PK complex activity. Both the presence of DSBs and a decreased end joining activity have been reported in AD brains, but the molecular player causing DNA repair dysfunction is still undetermined. β-Amyloid (Aβ), a potential proximate effector of neurotoxicity in AD, might exert cytotoxic effects by reactive oxygen species generation and oxidative stress induction, which may then cause DNA damage. Here, we show that in PC12 cells sublethal concentrations of aggregated Aβ(25-35) inhibit DNA-PK kinase activity, compromising DSB repair and sensitizing cells to nonlethal oxidative injury. The inhibition of DNA-PK activity is associated with down-regulation of the catalytic subunit DNA-PK (DNA-PKcs) protein levels, caused by oxidative stress and reversed by antioxidant treatment. Moreover, we show that sublethal doses of Aβ(1-42) oligomers enter the nucleus of PC12 cells, accumulate as insoluble oligomeric species, and reduce DNA-PK kinase activity, although in the absence of oxidative stress. Overall, these findings suggest that Aβ mediates inhibition of the DNA-PK-dependent nonhomologous end joining pathway contributing to the accumulation of DSBs that, if not efficiently repaired, may lead to the neuronal loss observed in AD.
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Affiliation(s)
- Alessio Cardinale
- Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome 00166, Italy
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39
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Axelsen PH, Komatsu H, Murray IVJ. Oxidative stress and cell membranes in the pathogenesis of Alzheimer's disease. Physiology (Bethesda) 2011; 26:54-69. [PMID: 21357903 DOI: 10.1152/physiol.00024.2010] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Amyloid β proteins and oxidative stress are believed to have central roles in the development of Alzheimer's disease. Lipid membranes are among the most vulnerable cellular components to oxidative stress, and membranes in susceptible regions of the brain are compositionally distinct from those in other tissues. This review considers the evidence that membranes are either a source of neurotoxic lipid oxidation products or the target of pathogenic processes involving amyloid β proteins that cause permeability changes or ion channel formation. Progress toward a comprehensive theory of Alzheimer's disease pathogenesis is discussed in which lipid membranes assume both roles and promote the conversion of monomeric amyloid β proteins into fibrils, the pathognomonic histopathological lesion of the disease.
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Affiliation(s)
- Paul H Axelsen
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
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40
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Mukhamedyarov MA, Teplov AY, Grishin SN, Leushina AV, Zefirov AL, Palotás A. Extraneuronal toxicity of Alzheimer's β-amyloid peptide: Comparative study on vertebrate skeletal muscles. Muscle Nerve 2011; 43:872-7. [DOI: 10.1002/mus.22000] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2010] [Indexed: 11/10/2022]
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41
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Croce N, Dinallo V, Ricci V, Federici G, Caltagirone C, Bernardini S, Angelucci F. Neuroprotective effect of neuropeptide Y against β-amyloid 25-35 toxicity in SH-SY5Y neuroblastoma cells is associated with increased neurotrophin production. NEURODEGENER DIS 2011; 8:300-9. [PMID: 21346312 DOI: 10.1159/000323468] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 12/09/2010] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND In the central nervous system, several neuropeptides are believed to be involved in the pathophysiology of Alzheimer's disease (AD). Among them, neuropeptide Y (NPY) is a small peptide widely distributed throughout the brain, where it serves as a neurotransmitter and/or a modulator of several neuroendocrine functions. More recently, NPY has generated interest because of its role in neuroprotection against excitotoxicity and modulation of neurogenesis. Interestingly, these effects are also influenced by neurotrophins, critical molecules for the function and survival of neurons that degenerate in AD. OBJECTIVE Our purpose was to investigate whether NPY might be a neuroprotective agent in AD and whether neurotrophins are involved in NPY-induced neuroprotection. METHODS To test this hypothesis, we exposed the SH-SY5Y neuroblastoma cell line to toxic concentrations of β-amyloid (Aβ) peptide fragment 25-35 (Aβ(25-35)) and measured cell survival and neurotrophin expression before and after a preincubation with NPY in the growth medium. RESULTS Our results demonstrated that preincubation with NPY prevented cell loss due to the toxic effect of Aβ(25-35). Moreover, while intracellular production of nerve growth factor and brain-derived neurotrophic factor were reduced by Aβ, NPY restored or even increased neurotrophin protein and mRNA in SH-SY5Y cells. CONCLUSION In conclusion, this study demonstrates that NPY increases the survival of SH-SY5Y neuroblastoma cells and counteracts the toxic effect of Aβ. In addition, NPY restores the neurotrophin levels in these cells. Although preliminary, these observations might be useful to understand the pathology of Alzheimer's and/or develop new therapeutic strategies.
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42
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Gorbenko G, Trusova V. Protein aggregation in a membrane environment. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2011; 84:113-42. [DOI: 10.1016/b978-0-12-386483-3.00002-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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43
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Kittner M, Knecht V. Disordered versus Fibril-like Amyloid β (25−35) Dimers in Water: Structure and Thermodynamics. J Phys Chem B 2010; 114:15288-95. [DOI: 10.1021/jp1065264] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Madeleine Kittner
- Department of Theory and Bio-Systems, Max-Planck-Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Volker Knecht
- Department of Theory and Bio-Systems, Max-Planck-Institute of Colloids and Interfaces, 14424 Potsdam, Germany
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44
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Schauerte JA, Wong PT, Wisser KC, Ding H, Steel DG, Gafni A. Simultaneous single-molecule fluorescence and conductivity studies reveal distinct classes of Abeta species on lipid bilayers. Biochemistry 2010; 49:3031-9. [PMID: 20201586 DOI: 10.1021/bi901444w] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The extracellular senile plaques prevalent in brain tissue in Alzheimer's disease (AD) are composed of amyloid fibrils formed by the Abeta peptide. These fibrils have been traditionally believed to be featured in neurotoxicity; however, numerous recent studies provide evidence that cytotoxicity in AD may be associated with low-molecular weight oligomers of Abeta that associate with neuronal membranes and may lead to membrane permeabilization and disruption of the ion balance in the cell. The underlying mechanism leading to disruption of the membrane is the subject of many recent studies. Here we report the application of single-molecule optical detection, using fluorescently labeled human Alphabeta40, combined with membrane conductivity measurements, to monitor the interaction of single-oligomeric peptide structures with model planar black lipid membranes (BLMs). In a qualitative study, we show that the binding of Alphabeta to the membrane can be described by three distinctly different behaviors, depending on the Alphabeta monomer concentration. For concentrations much below 10 nM, there is uniform binding of monomers over the surface of the membrane with no evidence of oligomer formation or membrane permeabilization. Between 10 nM and a few hundred nanomolar, the uniform monomer binding is accompanied by the presence of peptide species ranging from dimers to small oligomers. The dimers are not found to permeabilize the membrane, but the larger oligomers lead to permeabilization with individual oligomers producing ion conductances of <10 pS/pore. At higher concentrations, perhaps beyond physiologically relevant concentrations, larger extended and dynamic structures are found with large conductances (hundreds of picosiemens), suggesting a major disruption of the membrane.
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Affiliation(s)
- Joseph A Schauerte
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
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45
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Kaminsky YG, Marlatt MW, Smith MA, Kosenko EA. Subcellular and metabolic examination of amyloid-beta peptides in Alzheimer disease pathogenesis: evidence for Abeta(25-35). Exp Neurol 2009; 221:26-37. [PMID: 19751725 DOI: 10.1016/j.expneurol.2009.09.005] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 09/03/2009] [Accepted: 09/04/2009] [Indexed: 11/28/2022]
Abstract
Amyloid-beta peptide (Abeta) is a central player in the pathogenesis and diagnosis of Alzheimer disease. It aggregates to form the core of Alzheimer disease-associated plaques found in coordination with tau deposits in diseased individuals. Despite this clinical relevance, no single hypothesis satisfies and explicates the role of Abeta in toxicity and progression of the disease. To explore this area, investigators have focused on mechanisms of cellular dysfunction, aggregation, and maladaptive responses. Extensive research has been conducted using various methodologies to investigate Abeta peptides and oligomers, and these multiple facets have provided a wealth of data from specific models. Notably, the utility of each experiment must be considered in regards to the brain environment. The use of Abeta(25-35) in studies of cellular dysfunction has provided data indicating that the peptide is indeed responsible for multiple disturbances to cellular integrity. We will review how Abeta peptide induces oxidative stress and calcium homeostasis, and how multiple enzymes are deleteriously impacted by Abeta(25-35). Understanding and discussing the origin and properties of Abeta peptides is essential to evaluating their effects on various intracellular metabolic processes. Attention will also be specifically directed to metabolic compartmentation in affected brain cells, including mitochondrial, cytosolic, nuclear, and lysosomal enzymes.
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Affiliation(s)
- Yury G Kaminsky
- Institute of Theoretical and Experimental Biophysics, RAS, Pushchino, Russia.
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46
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Nicolas P, El Amri C. The dermaseptin superfamily: A gene-based combinatorial library of antimicrobial peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:1537-50. [DOI: 10.1016/j.bbamem.2008.09.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 09/14/2008] [Accepted: 09/18/2008] [Indexed: 10/21/2022]
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Sánchez-Bautista S, Corbalán-García S, Pérez-Lara A, Gómez-Fernández JC. A comparison of the membrane binding properties of C1B domains of PKCgamma, PKCdelta, and PKCepsilon. Biophys J 2009; 96:3638-47. [PMID: 19413969 DOI: 10.1016/j.bpj.2009.02.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Revised: 02/10/2009] [Accepted: 02/12/2009] [Indexed: 01/05/2023] Open
Abstract
The C1 domains of classical and novel PKCs mediate their diacylglycerol-dependent translocation. Using fluorescence resonance energy transfer, we studied the contribution of different negatively charged phospholipids and diacylglycerols to membrane binding. Three different C1B domains of PKCs were studied (the classical gamma, and the novel delta and epsilon), together with different lipid mixtures containing three types of acidic phospholipids and three types of activating diacylglycerols. The results show that C1Bgamma and C1Bepsilon exhibit a higher affinity to bind to vesicles containing 1-palmitoyl-2-oleoyl-sn-phosphatidic acid, 1-palmitoyl-2-oleoyl-sn-phoshatidylserine, or 1-palmitoyl-2-oleoyl-sn-phosphatidylglycerol, with C1Bepsilon being the most relevant case because its affinity for POPA-containing vesicles increased by almost two orders of magnitude. When the effect of the diacylglycerol fatty acid composition on membrane binding was studied, the C1Bepsilon domain showed the highest binding affinity to membranes containing 1-stearoyl-oleoyl-sn-glycerol or 1,2-sn-dioleoylglycerol with POPA as the acidic phospholipid. Of the three diacylglycerols used in this study, 1,2-sn-dioleoylglycerol and 1-stearoyl-oleoyl-sn-glycerol showed the highest affinities for each isoenzyme, whereas 1,2-sn-dipalmitoylglycerol; showed the lowest affinity. DSC experiments showed this to be a consequence of the nonfluid conditions of 1,2-sn-dipalmitoylglycerol;-containing systems.
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Affiliation(s)
- Sonia Sánchez-Bautista
- Departamento de Bioquímica y Biología Molecular A, Facultad de Veterinaria, Universidad de Murcia, E-30080-Murcia, Spain
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Wong PT, Schauerte JA, Wisser KC, Ding H, Lee EL, Steel DG, Gafni A. Amyloid-beta membrane binding and permeabilization are distinct processes influenced separately by membrane charge and fluidity. J Mol Biol 2008; 386:81-96. [PMID: 19111557 DOI: 10.1016/j.jmb.2008.11.060] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 11/25/2008] [Accepted: 11/30/2008] [Indexed: 10/21/2022]
Abstract
The 40 and 42 residue amyloid-beta (Abeta) peptides are major components of the proteinaceous plaques prevalent in the Alzheimer's disease-afflicted brain and have been shown to have an important role in instigating neuronal degeneration. Whereas it was previously thought that Abeta becomes cytotoxic upon forming large fibrillar aggregates, recent studies suggest that soluble intermediate-sized oligomeric species cause cell death through membrane permeabilization. The present study examines the interactions between Abeta40 and lipid membranes using liposomes as a model system to determine how changes in membrane composition influence the conversion of Abeta into these toxic species. Abeta40 membrane binding was monitored using fluorescence-based assays with a tryptophan-substituted peptide (Abeta40 [Y10W]). We extend previous observations that Abeta40 interacts preferentially with negatively charged membranes, and show that binding of nonfibrillar, low molecular mass oligomers of Abeta40 to anionic, but not neutral, membranes involves insertion of the peptide into the bilayer, as well as sequential conformational changes corresponding to the degree of oligomerization induced. Significantly, while anionic membranes in the gel, liquid crystalline, and liquid ordered phases induce these conformational changes equally, membrane permeabilization is reduced dramatically as the fluidity of the membrane is decreased. These findings demonstrate that binding alone is not sufficient for membrane permeabilization, and that the latter is also highly dependent on the fluidity and phase of the membrane. We conclude that binding and pore formation are two distinct steps. The differences in Abeta behavior induced by membrane composition may have significant implications on the development and progression of AD as neuronal membrane composition is altered with age.
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Affiliation(s)
- Pamela T Wong
- Department of Biological Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109, USA
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Interaction between Alzheimer's Aβ(25–35) peptide and phospholipid bilayers: The role of cholesterol. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:2710-6. [DOI: 10.1016/j.bbamem.2008.07.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Revised: 07/17/2008] [Accepted: 07/17/2008] [Indexed: 11/20/2022]
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50
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Ausili A, Torrecillas A, Martínez-Senac MM, Corbalán-García S, Gómez-Fernández JC. The interaction of the Bax C-terminal domain with negatively charged lipids modifies the secondary structure and changes its way of insertion into membranes. J Struct Biol 2008; 164:146-52. [DOI: 10.1016/j.jsb.2008.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Revised: 07/04/2008] [Accepted: 07/07/2008] [Indexed: 10/21/2022]
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