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Piccarducci R, Caselli MC, Zappelli E, Ulivi L, Daniele S, Siciliano G, Ceravolo R, Mancuso M, Baldacci F, Martini C. The Role of Amyloid-β, Tau, and α-Synuclein Proteins as Putative Blood Biomarkers in Patients with Cerebral Amyloid Angiopathy. J Alzheimers Dis 2022; 89:1039-1049. [PMID: 35964181 DOI: 10.3233/jad-220216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Cerebral amyloid angiopathy (CAA) is a cerebrovascular disorder characterized by the deposition of amyloid-β protein (Aβ) within brain blood vessels that develops in elderly people and Alzheimer's disease (AD) patients. Therefore, the investigation of biomarkers able to differentiate CAA patients from AD patients and healthy controls (HC) is of great interest, in particular in peripheral fluids. OBJECTIVE The current study aimed to detect the neurodegenerative disease (ND)-related protein (i.e., Aβ 1 - 40, Aβ 1 - 42, tau, and α-synuclein) levels in both red blood cells (RBCs) and plasma of CAA patients and HC, evaluating their role as putative peripheral biomarkers for CAA. METHODS For this purpose, the proteins' concentration was quantified in RBCs and plasma by homemade immunoenzymatic assays in an exploratory cohort of 20 CAA patients and 20 HC. RESULTS The results highlighted a significant increase of Aβ 1 - 40 and α-synuclein concentrations in both RBCs and plasma of CAA patients, while higher Aβ 1 - 42 and t-tau levels were detected only in RBCs of CAA individuals compared to HC. Moreover, Aβ 1 - 42/Aβ 1 - 40 ratio increased in RBCs and decreased in plasma of CAA patients. The role of these proteins as candidate peripheral biomarkers easily measurable with a blood sample in CAA needs to be confirmed in larger studies. CONCLUSION In conclusion, we provide evidence concerning the possible use of blood biomarkers for contributing to CAA diagnosis and differentiation from other NDs.
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Affiliation(s)
| | - Maria Chiara Caselli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Leonardo Ulivi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Gabriele Siciliano
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Roberto Ceravolo
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Michelangelo Mancuso
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Filippo Baldacci
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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2
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Design of pyrene functionalized triazole linked organosilane for specific detection of Ce3+ ions. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.130787] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Anand BG, Prajapati KP, Dubey K, Ahamad N, Shekhawat DS, Rath PC, Joseph GK, Kar K. Self-Assembly of Artificial Sweetener Aspartame Yields Amyloid-like Cytotoxic Nanostructures. ACS NANO 2019; 13:6033-6049. [PMID: 31021591 DOI: 10.1021/acsnano.9b02284] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Recent reports have revealed the intrinsic propensity of single aromatic metabolites to undergo self-assembly and form nanostructures of amyloid nature. Hence, identifying whether aspartame, a universally consumed artificial sweetener, is inherently aggregation prone becomes an important area of investigation. Although the reports on aspartame-linked side effects describe a multitude of metabolic disorders, the mechanistic understanding of such destructive effects is largely mysterious. Since aromaticity, an aggregation-promoting factor, is intrinsic to aspartame's chemistry, it is important to know whether aspartame can undergo self-association and if such a property can predispose any cytotoxicity to biological systems. Our study finds that aspartame molecules, under mimicked physiological conditions, undergo a spontaneous self-assembly process yielding regular β-sheet-like cytotoxic nanofibrils of amyloid nature. The resultant aspartame fibrils were found to trigger amyloid cross-seeding and become a toxic aggregation trap for globular proteins, Aβ peptides, and aromatic metabolites that convert native structures to β-sheet-like fibrils. Aspartame fibrils were also found to induce hemolysis, causing DNA damage resulting in both apoptosis and necrosis-mediated cell death. Specific spatial arrangement between aspartame molecules is predicted to form a regular amyloid-like architecture with a sticky exterior that is capable of promoting viable H-bonds, electrostatic interactions, and hydrophobic contacts with biomolecules, leading to the onset of protein aggregation and cell death. Results reveal that the aspartame molecule is inherently amyloidogenic, and the self-assembly of aspartame becomes a toxic trap for proteins and cells, exposing the bitter side of such a ubiquitously used artificial sweetener.
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Affiliation(s)
- Bibin Gnanadhason Anand
- Department of Bioscience and Bioengineering , Indian Institute of Technology Jodhpur , Jodhpur 342037 , India
| | | | - Kriti Dubey
- School of Life Sciences , Jawaharlal Nehru University , New Delhi 110067 , India
| | - Naseem Ahamad
- School of Life Sciences , Jawaharlal Nehru University , New Delhi 110067 , India
| | - Dolat Singh Shekhawat
- Department of Bioscience and Bioengineering , Indian Institute of Technology Jodhpur , Jodhpur 342037 , India
| | - Pramod Chandra Rath
- School of Life Sciences , Jawaharlal Nehru University , New Delhi 110067 , India
| | - George Kodimattam Joseph
- Department of Bioscience and Bioengineering , Indian Institute of Technology Jodhpur , Jodhpur 342037 , India
| | - Karunakar Kar
- School of Life Sciences , Jawaharlal Nehru University , New Delhi 110067 , India
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4
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Tatulian SA, Kandel N. Membrane Pore Formation by Peptides Studied by Fluorescence Techniques. Methods Mol Biol 2019; 2003:449-464. [PMID: 31218629 DOI: 10.1007/978-1-4939-9512-7_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pore formation in cellular membranes by pathogen-derived proteins is a mechanism utilized by a set of microbes to exert their cytotoxic effect. On the other hand, the host cells have developed a defense mechanism to produce antimicrobial peptides to kill the pathogens by a similar, membrane perforation mechanism. Furthermore, certain endogenous proteins or peptides kill the parent cells through membrane permeabilization. Analysis of the molecular details of membrane pore formation is often conducted using artificial systems, such as bilayer lipid membranes and synthetic peptides. This chapter describes two fluorescence-based methods to study peptide-induced membrane leakage. One method involves preparation of lipid vesicles loaded with a fluorophore (e.g., calcein or carboxyfluorescein) at a self-quenching concentration. If the externally added peptide forms relatively large pores (≥1 nm in diameter), the fluorophore leaks out and undergoes dequenching, resulting in time-dependent increase in fluorescence. The other method is designed to monitor smaller pores (<1 nm in diameter). It involves preparation of vesicles in a Ca2+-less buffer, containing a Ca2+-dependent fluorophore, such as Quin-2. Removal of external Quin-2 by a desalting column and addition of an appropriate concentration of CaCl2 externally sequesters Quin-2 and Ca2+ ions by the vesicle membrane. Addition of the pore-forming peptide to these vesicles results in membrane permeabilization, Ca2+ influx and binding to Quin-2. In both cases, the kinetics of the increase of fluorescence and its equilibrium levels allow quantitative analysis of the pore formation mechanism.
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Affiliation(s)
- Suren A Tatulian
- Department of Physics, University of Central Florida, Orlando, FL, USA.
| | - Nabin Kandel
- Department of Physics, University of Central Florida, Orlando, FL, USA
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5
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Rangachari V, Dean DN, Rana P, Vaidya A, Ghosh P. Cause and consequence of Aβ - Lipid interactions in Alzheimer disease pathogenesis. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2018; 1860:1652-1662. [PMID: 29526709 PMCID: PMC6133763 DOI: 10.1016/j.bbamem.2018.03.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 02/28/2018] [Accepted: 03/02/2018] [Indexed: 12/14/2022]
Abstract
Self-templating propagation of protein aggregate conformations is increasingly becoming a significant factor in many neurological diseases. In Alzheimer disease (AD), intrinsically disordered amyloid-β (Aβ) peptides undergo aggregation that is sensitive to environmental conditions. High-molecular weight aggregates of Aβ that form insoluble fibrils are deposited as senile plaques in AD brains. However, low-molecular weight aggregates called soluble oligomers are known to be the primary toxic agents responsible for neuronal dysfunction. The aggregation process is highly stochastic involving both homotypic (Aβ-Aβ) and heterotypic (Aβ with interacting partners) interactions. Two of the important members of interacting partners are membrane lipids and surfactants, to which Aβ shows a perpetual association. Aβ-membrane interactions have been widely investigated for more than two decades, and this research has provided a wealth of information. Although this has greatly enriched our understanding, the objective of this review is to consolidate the information from the literature that collectively showcases the unique phenomenon of lipid-mediated Aβ oligomer generation, which has largely remained inconspicuous. This is especially important because Aβ aggregate "strains" are increasingly becoming relevant in light of the correlations between the structure of aggregates and AD phenotypes. Here, we will focus on aspects of Aβ-lipid interactions specifically from the context of how lipid modulation generates a wide variety of biophysically and biochemically distinct oligomer sub-types. This, we believe, will refocus our thinking on the influence of lipids and open new approaches in delineating the mechanisms of AD pathogenesis. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
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Affiliation(s)
- Vijayaraghavan Rangachari
- Department of Chemistry & Biochemistry, University of Southern Mississippi, Hattiesburg, MS 39406, USA.
| | - Dexter N Dean
- Department of Chemistry & Biochemistry, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Pratip Rana
- Department of Computer Science, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Ashwin Vaidya
- Department of Mathematical Science, Montclair State University, Montclair, NJ 07043, USA
| | - Preetam Ghosh
- Department of Computer Science, Virginia Commonwealth University, Richmond, VA 23284, USA
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6
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Role of the cell membrane interface in modulating production and uptake of Alzheimer's beta amyloid protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1639-1651. [PMID: 29572033 DOI: 10.1016/j.bbamem.2018.03.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 12/22/2022]
Abstract
The beta amyloid protein (Aβ) plays a central role in Alzheimer's disease (AD) pathogenesis and its interaction with cell membranes in known to promote mutually disruptive structural perturbations that contribute to amyloid deposition and neurodegeneration in the brain. In addition to protein aggregation at the membrane interface and disruption of membrane integrity, growing reports demonstrate an important role for the membrane in modulating Aβ production and uptake into cells. The aim of this review is to highlight and summarize recent literature that have contributed insight into the implications of altered membrane composition on amyloid precursor protein (APP) proteolysis, production of Aβ, its internalization in to cells via permeabilization and receptor mediated uptake. Here, we also review the various membrane model systems and experimental tools used for probing Aβ-membrane interactions to investigate the key mechanistic aspects underlying the accumulation and toxicity of Aβ in AD.
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7
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Rose C, Dorard E, Audrain M, Gorisse-Hussonnois L, Cartier N, Braudeau J, Allinquant B. Transient increase in sAPPα secretion in response to Aβ1–42 oligomers: an attempt of neuronal self-defense? Neurobiol Aging 2018; 61:23-35. [DOI: 10.1016/j.neurobiolaging.2017.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 09/08/2017] [Accepted: 09/09/2017] [Indexed: 12/19/2022]
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8
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Intrinsic property of phenylalanine to trigger protein aggregation and hemolysis has a direct relevance to phenylketonuria. Sci Rep 2017; 7:11146. [PMID: 28894147 PMCID: PMC5593866 DOI: 10.1038/s41598-017-10911-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/15/2017] [Indexed: 01/31/2023] Open
Abstract
Excess accumulation of phenylalanine is the characteristic of untreated Phenylketonuria (PKU), a well-known genetic abnormality, which triggers several neurological, physical and developmental severities. However, the fundamental mechanism behind the origin of such diverse health problems, particularly the issue of how they are related to the build-up of phenylalanine molecules in the body, is largely unknown. Here, we show cross-seeding ability of phenylalanine fibrils that can effectively initiate an aggregation process in proteins under physiological conditions, converting native protein structures to β-sheet assembly. The resultant fibrils were found to cause severe hemolysis, yielding a plethora of deformed erythrocytes that is highly relevant to phenylketonuria. Unique arrangement of zwitterionic phenylalanine molecules in their amyloid-like higher order entities is predicted to promote both hydrophobic and electrostatic interaction, sufficient enough to trap proteins and to preferentially interact with the membrane components of RBCs. Since the prevalence of hemolysis and amyloid related psychoneurological severities are mostly observed in PKU patients, we propose that the inherent property of phenylalanine fibrils to trigger hemolysis and to induce protein aggregation may have direct relevance to the disease mechanism of PKU.
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Dorosh L, Stepanova M. Probing oligomerization of amyloid beta peptide in silico. MOLECULAR BIOSYSTEMS 2017; 13:165-182. [PMID: 27844078 DOI: 10.1039/c6mb00441e] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Aggregation of amyloid β (Aβ) peptide is implicated in fatal Alzheimer's disease, for which no cure is available. Understanding the mechanisms responsible for this aggregation is required in order for therapies to be developed. In an effort to better understand the molecular mechanisms involved in spontaneous aggregation of Aβ peptide, extensive molecular dynamics simulations are reported, and the results are analyzed through a combination of structural biology tools and a novel essential collective dynamics method. Several model systems composed of ten or twelve Aβ17-42 chains in water are investigated, and the influence of metal ions is probed. The results suggest that Aβ monomers tend to aggregate into stable globular-like oligomers with 13-23% of β-sheet content. Two stages of oligomer formation have been identified: quick collapse within the first 40 ns of the simulation, characterized by a decrease in inter-chain separation and build-up of β-sheets, and the subsequent slow relaxation of the oligomer structure. The resulting oligomers comprise a stable, coherently moving sub-aggregate of 6-9 strongly inter-correlated chains. Cu2+ and Fe2+ ions have been found to develop coordination bonds with carboxylate groups of E22, D23 and A42, which remain stable during 200 ns simulations. The presence of Fe2+, and particularly Cu2+ ions, in negatively charged cavities has been found to cause significant changes in the structure and dynamics of the oligomers. The results indicate, in particular, that formation of non-fibrillar oligomers might be involved in early template-free aggregation of Aβ17-42 monomers, with charged species such as Cu2+ or Fe2+ ions playing an important role.
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Affiliation(s)
- L Dorosh
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada. and National Research Council of Canada, Edmonton, Alberta, Canada
| | - M Stepanova
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada. and National Research Council of Canada, Edmonton, Alberta, Canada and Department of Physics, Astronomy, and Materials Science, Missouri State University, Springfield, MO, USA
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10
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Common molecular mechanism of amyloid pore formation by Alzheimer's β-amyloid peptide and α-synuclein. Sci Rep 2016; 6:28781. [PMID: 27352802 PMCID: PMC4926208 DOI: 10.1038/srep28781] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/08/2016] [Indexed: 12/16/2022] Open
Abstract
Calcium-permeable pores formed by small oligomers of amyloid proteins are the primary pathologic species in Alzheimer’s and Parkinson’s diseases. However, the molecular mechanisms underlying the assembly of these toxic oligomers in the plasma membrane of brain cells remain unclear. Here we have analyzed and compared the pore-forming capability of a large panel of amyloid proteins including wild-type, variant and truncated forms, as well as synthetic peptides derived from specific domains of Aβ1-42 and α-synuclein. We show that amyloid pore formation involves two membrane lipids, ganglioside and cholesterol, that physically interact with amyloid proteins through specific structural motifs. Mutation or deletion of these motifs abolished pore formation. Moreover, α-synuclein (Parkinson) and Aβ peptide (Alzheimer) did no longer form Ca2+-permeable pores in presence of drugs that target either cholesterol or ganglioside or both membrane lipids. These results indicate that gangliosides and cholesterol cooperate to favor the formation of amyloid pores through a common molecular mechanism that can be jammed at two different steps, suggesting the possibility of a universal therapeutic approach for neurodegenerative diseases. Finally we present the first successful evaluation of such a new therapeutic approach (coined “membrane therapy”) targeting amyloid pores formed by Aβ1-42 and α-synuclein.
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Marciani DJ. A retrospective analysis of the Alzheimer's disease vaccine progress - The critical need for new development strategies. J Neurochem 2016; 137:687-700. [PMID: 26990863 DOI: 10.1111/jnc.13608] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 02/25/2016] [Accepted: 02/26/2016] [Indexed: 12/16/2022]
Abstract
The promising results obtained with aducanumab and solanezumab against Alzheimer's disease (AD) strengthen the vaccine approach to prevent AD, despite of the many clinical setbacks. It has been problematic to use conjugated peptides with Th1/Th2 adjuvants to induce immune responses against conformational epitopes formed by Aβ oligomers, which is critical to induce protective antibodies. Hence, vaccination should mimic natural immunity by using whole or if possible conjugated antigens, but biasing the response to Th2 with anti-inflammatory adjuvants. Also, selection of the carrier and cross-linking agents is important to prevent suppression of the immune response against the antigen. That certain compounds having phosphorylcholine or fucose induce a sole Th2 immunity would allow antigens with T-cell epitopes without inflammatory autoimmune reactions to be used. Another immunization method is DNA vaccines combined with antigenic ones, which favors the clonal selection and expansion of high affinity antibodies needed for immune protection, but this also requires Th2 immunity. Since AD transgenic mouse models have limited value for immunogen selection as shown by the clinical studies, screening may require the use of validated antibodies and biophysical methods to identify the antigens that would be most likely recognized by the human immune system and thus capable to stimulate a protective antibody response. To induce an anti-Alzheimer's disease protective immunity and prevent possible damage triggered by antigens having B-cell epitopes-only, whole antigens might be used; while inducing Th2 immunity with sole anti-inflammatory fucose-based adjuvants. This approach would avert a damaging systemic inflammatory immunity and the suppression of immunoresponse against the antigen because of carrier and cross-linkers; immune requirements that extend to DNA vaccines.
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Barrett MA, Trapp M, Lohstroh W, Seydel T, Ollivier J, Ballauff M, Dencher NA, Hauß T. Alzheimer's peptide amyloid-β, fragment 22-40, perturbs lipid dynamics. SOFT MATTER 2016; 12:1444-51. [PMID: 26646730 DOI: 10.1039/c5sm02026c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The peptide amyloid-β (Aβ) interacts with membranes of cells in the human brain and is associated with Alzheimer's disease (AD). The intercalation of Aβ in membranes alters membrane properties, including the structure and lipid dynamics. Any change in the membrane lipid dynamics will affect essential membrane processes, such as energy conversion, signal transduction and amyloid precursor protein (APP) processing, and may result in the observed neurotoxicity associated with the disease. The influence of this peptide on membrane dynamics was studied with quasi-elastic neutron scattering, a technique which allows a wide range of observation times from picoseconds to nanoseconds, over nanometer length scales. The effect of the membrane integral neurotoxic peptide amyloid-β, residues 22-40, on the in- and out-of-plane lipid dynamics was observed in an oriented DMPC/DMPS bilayer at 15 °C, in its gel phase, and at 30 °C, near the phase transition temperature of the lipids. Near the phase-transition temperature, a 1.5 mol% of peptide causes up to a twofold decrease in the lipid diffusion coefficients. In the gel-phase, this effect is reversed, with amyloid-β(22-40) increasing the lipid diffusion coefficients. The observed changes in lipid diffusion are relevant to protein-protein interactions, which are strongly influenced by the diffusion of membrane components. The effect of the amyloid-β peptide fragment on the diffusion of membrane lipids will provide insight into the membrane's role in AD.
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Affiliation(s)
- Matthew A Barrett
- Helmholtz-Zentrum Berlin für Materialien und Energie, Lise-Meitner-Campus, Berlin, Germany.
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Benterud T, Pankratov L, Solberg R, Bolstad N, Skinningsrud A, Baumbusch L, Sandvik L, Saugstad OD. Perinatal Asphyxia May Influence the Level of Beta-Amyloid (1-42) in Cerebrospinal Fluid: An Experimental Study on Newborn Pigs. PLoS One 2015; 10:e0140966. [PMID: 26501201 PMCID: PMC4621034 DOI: 10.1371/journal.pone.0140966] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 08/20/2015] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE Total tau (T-tau), phosphorylated tau (p-Tau) and Beta-Amyloid 1-42 (AB42) in Cerebrospinal Fluid (CSF) are useful biomarkers in neurodegenerative diseases. The aim of the study was to investigate the role of these and other CSF biomarkers (T-tau, p-Tau, AB42, S100B and NSE), during hypoxia-reoxygenation in a newborn pig model. DESIGN Thirty newborn pigs were included in a study of moderate or severe hypoxia. The moderate hypoxia group (n = 12) was exposed to global hypoxia (8% O2) until Base excess (BE) reached -15 mmol/l. The pigs in the group exposed to severe hypoxia (n = 12) received 8% O2 until BE reached -20 mmol/l or mean Blood Pressure fell below 20 mm Hg, The control group (n = 6) was kept at room air. For all treatments, the CSF was collected at 9.5 hours after the intervention. RESULTS The level of AB42 in CSF was significantly lower in the pigs exposed to severe hypoxia compared with the control group, 922(SD +/-445)pg/ml versus. 1290(SD +/-143) pg/ml (p<0.05), respectively. Further, a non-significant reduction of AB42 was observed in the group exposed to moderate hypoxia T-tau and p-Tau revealed no significant differences between the intervention groups and the control group, however a significantly higher level of S100B was seen in the CSF of pigs receiving hypoxia in comparison to the level in the control group. Further on, there was a moderate negative correlation between the levels of AB42 and S100B in CSF, as well as a moderate negative correlation between Lactate in blood at end of hypoxia and AB42 in CSF. INTERPRETATION This is the first study to our knowledge that demonstrated a significant drop in AB42 in CSF after neonatal hypoxia. Whether or not this has an etiological basis for adult neurodegenerative disorders needs to be studied with additional experiments and epidemiological studies. AB42 and S100B are significantly changed in neonatal pigs subjected to hypoxia compared to controls and thus may be valuable biomarkers of perinatal asphyxia.
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Affiliation(s)
- Torkil Benterud
- Dept of Pediatric Research, Oslo University Hospital, Oslo, Norway
- * E-mail: ;
| | - Leonid Pankratov
- Dept of Pediatric Research, Oslo University Hospital, Oslo, Norway
| | - Rønnaug Solberg
- Dept of Pediatric Research, Oslo University Hospital, Oslo, Norway
| | - Nils Bolstad
- Dept of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Anders Skinningsrud
- Dept Multidisciplinary Lab Med & Med Biochem, Akershus Univ Hosp, Lørenskog, Norway
| | - Lars Baumbusch
- Dept of Pediatric Research, Oslo University Hospital, Oslo, Norway
| | - Leiv Sandvik
- Dept of Biostatistics and Epidemiology, Oslo University Hospital, Oslo, Norway
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Lipid insertion domain unfolding regulates protein orientational transition behavior in a lipid bilayer. Biophys Chem 2015; 206:22-39. [PMID: 26164502 DOI: 10.1016/j.bpc.2015.06.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 06/24/2015] [Accepted: 06/25/2015] [Indexed: 01/02/2023]
Abstract
We have used coarse-grained (CG) and united atom (UA) molecular dynamics simulations to explore the mechanisms of protein orientational transition of a model peptide (Aβ42) in a phosphatidylcholine/cholesterol (PC/CHO) lipid bilayer. We started with an inserted state of Aβ42 containing a folded (I) or unfolded (II) K28-A42 lipid insertion domain (LID), which was stabilized by the K28-snorkeling and A42-anchoring to the PC polar groups in the lipid bilayer. After a UA-to-CG transformation and a 1000ns-CG simulation for enhancing the sampling of protein orientations, we discovered two transitions: I-to-"deep inserted" state with disrupted K28-snorkeling and II-to-"deep surface" state with disrupted A42-anchoring. The new states remained stable after a CG-to-UA transformation and a 200ns-UA simulation relaxation. Significant changes in the cholesterol-binding domain of Aβ42 and protein-induced membrane disruptions were evident after the transitions. We propose that the conformation of the LID regulates protein orientational transitions in the lipid membrane.
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Hashimoto M, Hossain S, Katakura M, Al Mamun A, Shido O. The binding of Aβ1-42 to lipid rafts of RBC is enhanced by dietary docosahexaenoic acid in rats: Implicates to Alzheimer's disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1402-9. [PMID: 25782726 DOI: 10.1016/j.bbamem.2015.03.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 02/13/2015] [Accepted: 03/09/2015] [Indexed: 11/18/2022]
Abstract
Once amyloid β peptides (Aβs) of the Alzheimer's disease build up in blood circulation, they are capable of binding to red blood cell (RBC) and inducing hemolysis of RBC. The mechanisms of the interactions between RBC and Aβ are largely unknown; however, it is very important for the therapeutic target of Aβ-induced hemolysis. In the present study, we investigated whether Aβ1-42 interacts with caveolin-1-containing detergent-resistant membranes (DRMs) of RBC and whether the interaction could be modulated by dietary pre-administration of docosahexaenoic acid (DHA). DHA pre-administration to rats inhibited hemolysis by Aβ1-42. This activity was accompanied by increased DHA levels and membrane fluidity and decreased cholesterol level, lipid peroxidation, and reactive oxygen species in the RBCs of the DHA-pretreated rats, suggesting that the antioxidative property of DHA may rescue RBCs from oxidative damage by Aβ1-42. The level of caveolin-1 was augmented in the DRMs of DHA-pretreated rats. Binding between Aβ1-42 and DRMs of RBC significantly increased in DHA-rats. When fluorescently labeled Aβ1-42 (TAMRA-Aβ1-42) was directly infused into the bloodstream, it again occupied the caveolin-1-containing DRMs of the RBCs from the DHA-rats to a greater extent, indicating that circulating Aβs interact with the caveolin-1-rich lipid rafts of DRMs and the interaction is stronger in the DHA-enriched RBCs. The levels of TAMRA-Aβ1-42 also increased in liver DRMs, whereas it decreased in plasma of DHA-pretreated rats. DHA might help clearance of circulating Aβs by increased lipid raft-dependent degradation pathways and implicate to therapies in Alzheimer's disease.
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Affiliation(s)
- Michio Hashimoto
- Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo, Shimane 693-8501, Japan.
| | - Shahdat Hossain
- Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo, Shimane 693-8501, Japan; Department of Biochemistry & Molecular Biology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh
| | - Masanori Katakura
- Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo, Shimane 693-8501, Japan
| | - Abdullah Al Mamun
- Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo, Shimane 693-8501, Japan
| | - Osamu Shido
- Department of Environmental Physiology, Shimane University Faculty of Medicine, Izumo, Shimane 693-8501, Japan
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Deleu M, Crowet JM, Nasir MN, Lins L. Complementary biophysical tools to investigate lipid specificity in the interaction between bioactive molecules and the plasma membrane: A review. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:3171-3190. [DOI: 10.1016/j.bbamem.2014.08.023] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 08/05/2014] [Accepted: 08/21/2014] [Indexed: 02/08/2023]
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17
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Zhou Q, Qi S, Sun X, Ge R. The interaction of a histidine-rich protein hpn with the membrane mimics: implications for pathologic roles of Hpn in Helicobacter pylori. Helicobacter 2014; 19:129-35. [PMID: 24494595 DOI: 10.1111/hel.12109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Hpn is a small histidine-rich protein in Helicobacter pylori. This protein has been shown to play roles in nickel storage and detoxification and to exhibit cytotoxicity to gastric epithelial cells. Hpn can be secreted outside of the bacterium and forms amyloid-like structures. OBJECTIVE To study the interactions between Hpn and membrane mimics, which may further our understanding of the pathologic roles of this bacterium. METHODS Various biochemical and biophysical methods, such as secondary structure determination be CD, calcein release assay with fluorescence spectrometry, and Laurdan and Prodan generalized polarization determination have been used to characterize the interaction between Hpn and membrane mimics. RESULTS Membrane mimics induced the formation of α-helix in Hpn. The interaction disrupts the integrity of the membrane mimics and leads to the release of inner calcein probe. The experiments involving the Laurdan and Prodan fluorescence indicated that increasing the total protein/lipid ratio leads to a less ordered and more hydrated lipid membrane structure close to the water/lipid interface of lipid bilayers modeling the mitochondrial inner membrane. CONCLUSION The present data indicated that Hpn may take part in the pathological roles of Helicobacter pylori through membrane interactions.
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Affiliation(s)
- Qinglu Zhou
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-Sen University, Guangzhou, China
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18
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Dony N, Crowet JM, Joris B, Brasseur R, Lins L. SAHBNET, an accessible surface-based elastic network: an application to membrane protein. Int J Mol Sci 2013; 14:11510-26. [PMID: 23722660 PMCID: PMC3709745 DOI: 10.3390/ijms140611510] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 05/02/2013] [Accepted: 05/20/2013] [Indexed: 11/06/2022] Open
Abstract
Molecular Dynamics is a method of choice for membrane simulations and the rising of coarse-grained forcefields has opened the way to longer simulations with reduced calculations times. Here, we present an elastic network, SAHBNET (Surface Accessibility Hydrogen-Bonds elastic NETwork), that will maintain the structure of soluble or membrane proteins based on the hydrogen bonds present in the atomistic structure and the proximity between buried residues. This network is applied on the coarse-grained beads defined by the MARTINI model, and was designed to be more physics-based than a simple elastic network. The SAHBNET model is evaluated against atomistic simulations, and compared with ELNEDYN models. The SAHBNET is then used to simulate two membrane proteins inserted in complex lipid bilayers. These bilayers are formed by self-assembly and the use of a modified version of the GROMACS tool genbox (which is accessible through the gcgs.gembloux.ulg.ac.be website). The results show that SAHBNET keeps the structure close to the atomistic one and is successfully used for the simulation of membrane proteins.
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Affiliation(s)
- Nicolas Dony
- Center of Protein Engineering, University of Liège, Institut de chimie B6a, B-4000 Liège, Belgium; E-Mails: (N.D.); (B.J.)
| | - Jean Marc Crowet
- Numerical Molecular Biophysics Unit, Gembloux Agro-Bio Tech, University of Liège, Passage des déportés, B-5030 Gembloux, Belgium; E-Mails: (J.M.C.); (R.B.)
| | - Bernard Joris
- Center of Protein Engineering, University of Liège, Institut de chimie B6a, B-4000 Liège, Belgium; E-Mails: (N.D.); (B.J.)
| | - Robert Brasseur
- Numerical Molecular Biophysics Unit, Gembloux Agro-Bio Tech, University of Liège, Passage des déportés, B-5030 Gembloux, Belgium; E-Mails: (J.M.C.); (R.B.)
| | - Laurence Lins
- Numerical Molecular Biophysics Unit, Gembloux Agro-Bio Tech, University of Liège, Passage des déportés, B-5030 Gembloux, Belgium; E-Mails: (J.M.C.); (R.B.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +32-81-622-521; Fax: +32-81-622-522
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19
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Kiko T, Nakagawa K, Satoh A, Tsuduki T, Furukawa K, Arai H, Miyazawa T. Amyloid β levels in human red blood cells. PLoS One 2012; 7:e49620. [PMID: 23166730 PMCID: PMC3499416 DOI: 10.1371/journal.pone.0049620] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 10/10/2012] [Indexed: 11/18/2022] Open
Abstract
UNLABELLED Amyloid β-peptide (Aβ) is hypothesized to play a key role by oxidatively impairing the capacity of red blood cells (RBCs) to deliver oxygen to the brain. These processes are implicated in the pathogenesis of Alzheimer's disease (AD). Although plasma Aβ has been investigated thoroughly, the presence and distribution of Aβ in human RBCs are still unclear. In this study, we quantitated Aβ40 and Aβ42 in human RBCs with ELISA assays, and provided evidence that significant amounts of Aβ could be detected in RBCs and that the RBC Aβ levels increased with aging. The RBC Aβ levels increased with aging. On the other hand, providing an antioxidant supplement (astaxanthin, a polar carotenoid) to humans was found to decrease RBC Aβ as well as oxidative stress marker levels. These results suggest that plasma Aβ40 and Aβ42 bind to RBCs (possibly with aging), implying a pathogenic role of RBC Aβ. Moreover, the data indicate that RBC Aβ40 and Aβ42 may constitute biomarkers of AD. As a preventive strategy, therapeutic application of astaxanthin as an Aβ-lowering agent in RBCs could be considered as a possible anti-dementia agent. TRIAL REGISTRATION Controlled-Trials.com ISRCTN42483402.
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Affiliation(s)
- Takehiro Kiko
- Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Kiyotaka Nakagawa
- Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Akira Satoh
- Life Science Institute, Yamaha Motor Company, Ltd., Shizuoka, Japan
| | - Tsuyoshi Tsuduki
- Laboratory of Food and Biomolecular Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Katsutoshi Furukawa
- Department of Geriatrics and Gerontology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Hiroyuki Arai
- Department of Geriatrics and Gerontology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Teruo Miyazawa
- Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
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20
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Crowet JM, Parton DL, Hall BA, Steinhauer S, Brasseur R, Lins L, Sansom MSP. Multi-Scale Simulation of the Simian Immunodeficiency Virus Fusion Peptide. J Phys Chem B 2012; 116:13713-21. [DOI: 10.1021/jp3027385] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Jean-Marc Crowet
- Centre de Biophysique Moléculaire
Numérique, Gembloux Agro-Bio Tech, University of Liège, 2 Passage des déportés,
B-5030 Gembloux, Belgium
| | - Daniel L. Parton
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1
3QU, United Kingdom
| | - Benjamin A. Hall
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1
3QU, United Kingdom
| | - Sven Steinhauer
- Centre de Biophysique Moléculaire
Numérique, Gembloux Agro-Bio Tech, University of Liège, 2 Passage des déportés,
B-5030 Gembloux, Belgium
| | - Robert Brasseur
- Centre de Biophysique Moléculaire
Numérique, Gembloux Agro-Bio Tech, University of Liège, 2 Passage des déportés,
B-5030 Gembloux, Belgium
| | - Laurence Lins
- Centre de Biophysique Moléculaire
Numérique, Gembloux Agro-Bio Tech, University of Liège, 2 Passage des déportés,
B-5030 Gembloux, Belgium
| | - Mark S. P. Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1
3QU, United Kingdom
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21
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Li H, Nelson CE, Evans BC, Duvall CL. Delivery of intracellular-acting biologics in pro-apoptotic therapies. Curr Pharm Des 2011; 17:293-319. [PMID: 21348831 DOI: 10.2174/138161211795049642] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 02/18/2011] [Indexed: 12/21/2022]
Abstract
The recent elucidation of molecular regulators of apoptosis and their roles in cellular oncogenesis has motivated the development of biomacromolecular anticancer therapeutics that can activate intracellular apoptotic signaling pathways. Pharmaceutical scientists have employed a variety of classes of biologics toward this goal, including antisense oligodeoxynucleotides, small interfering RNA, proteins, antibodies, and peptides. However, stability in the in vivo environment, tumor-specific biodistribution, cell internalization, and localization to the intracellular microenvironment where the targeted molecule is localized pose significant challenges that limit the ability to directly apply intracellular-acting, pro-apoptotic biologics for therapeutic use. Thus, approaches to improve the pharmaceutical properties of therapeutic biomacromolecules are of great significance and have included chemically modifying the bioactive molecule itself or formulation with auxiliary compounds. Recently, promising advances in delivery of pro-apoptotic biomacromolecular agents have been made using tools such as peptide "stapling", cell penetrating peptides, fusogenic peptides, liposomes, nanoparticles, smart polymers, and synergistic combinations of these components. This review will discuss the molecular mediators of cellular apoptosis, the respective mechanisms by which these mediators are dysregulated in cellular oncogenesis, the history and development of both nucleic-acid and amino-acid based drugs, and techniques to achieve intracellular delivery of these biologics. Finally, recent applications where pro-apoptotic functionality has been achieved through delivery of intracellular-acting biomacromolecular drugs will be highlighted.
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Affiliation(s)
- Hongmei Li
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA
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22
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Amadoro G, Corsetti V, Atlante A, Florenzano F, Capsoni S, Bussani R, Mercanti D, Calissano P. Interaction between NH(2)-tau fragment and Aβ in Alzheimer's disease mitochondria contributes to the synaptic deterioration. Neurobiol Aging 2011; 33:833.e1-25. [PMID: 21958963 DOI: 10.1016/j.neurobiolaging.2011.08.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 07/26/2011] [Accepted: 08/05/2011] [Indexed: 12/15/2022]
Abstract
Although amyloid beta (Aβ) peptide can promote tau pathology and its toxicity is concurrently tau-dependent, the underlying mechanisms of the in vivo interplay of these proteins remain unsolved. Structural and functional mitochondrial alterations play an early, precipitating role in synaptic failure of Alzheimer's disease (AD) pathogenesis and an aggravated mitochondrial impairment has been described in triple APP/PS/tau transgenic mice carrying both plaques and tangles, if compared with mice overexpressing tau or amyloid precursor protein (APP) alone. Here, we show that a neurotoxic aminoterminal (NH(2))-derived tau fragment mapping between 26 and 230 amino acids of the human tau40 isoform (441 amino acids)-but not the physiological full-length protein-preferentially interacts with Aβ peptide(s) in human AD synapses in association with mitochondrial adenine nucleotide translocator-1 (ANT-1) and cyclophilin D. The two peptides-Aβ 1-42 and the smaller and more potent NH(2)-26-44 peptide of the longest 20-22 kDa NH(2)-tau fragment-inhibit the ANT-1-dependent adenosine diphosphate-adenosine triphosphate (ADP/ATP) exchange in a noncompetitive and competitive manner, respectively, and together further aggravate the mitochondrial dysfunction by exacerbating the ANT-1 impairment. Taken together, these data establish a common, direct and synergistic toxicity of pathological APP and tau products on synaptic mitochondria and suggest potential, new pathway(s) and target(s) for a combined, more efficient therapeutic intervention of early synaptic dysfunction in AD.
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23
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Affiliation(s)
| | - Klaus Müllen
- Max Planck Institute for Polymer Research, Ackermannweg 10, P.O. Box 3148, Mainz, Germany
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24
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Fantini J, Carlus D, Yahi N. The fusogenic tilted peptide (67-78) of α-synuclein is a cholesterol binding domain. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2343-51. [PMID: 21756873 DOI: 10.1016/j.bbamem.2011.06.017] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 06/21/2011] [Accepted: 06/23/2011] [Indexed: 01/06/2023]
Abstract
Parkinson's disease-associated α-synuclein is an amyloidogenic protein not only expressed in the cytoplasm of neurons, but also secreted in the extracellular space and internalized into glial cells through a lipid raft-dependent process. We previously showed that α-synuclein interacts with raft glycosphingolipids through a structural motif common to various viral and amyloidogenic proteins. Here we report that α-synuclein also interacts with cholesterol, as assessed by surface pressure measurements of cholesterol-containing monolayers. Using a panel of recombinant fragments and synthetic peptides, we identified two distinct cholesterol-binding domains in α-synuclein. One of these domains, which corresponds to the tilted peptide of α-synuclein (67-78), bound cholesterol with high affinity and was toxic for cultured astrocytes. Molecular modeling suggested that cholesterol binds to this peptide with a tilt angle of 46°. α-synuclein also contains a cholesterol recognition consensus motif, which had a lower affinity for cholesterol and was devoid of toxicity. This motif is encased in the glycosphingolipid-binding domain (34-45) of α-synuclein. In raft-like model membranes containing both cholesterol and glycosphingolipids, the head groups of glycosphingolipids prevented the accessibility of cholesterol to exogenous ligands. Nevertheless, cholesterol appeared to 'signal' its presence by tuning glycosphingolipid conformation, thereby facilitating α-synuclein binding to raft-like membranes. We propose that the association of α-synuclein with lipid rafts involves both the binding of α-synuclein (34-45) to glycosphingolipids, and the interaction of the fusogenic tilted peptide (67-78) with cholesterol. Coincidentally, a similar mechanism is used by viruses (HIV-1, HTLV-I, Ebola) which display a tilted peptide and fuse with host cell membranes through a sphingolipid/cholesterol-dependent process.
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25
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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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26
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Argyri L, Skamnaki V, Stratikos E, Chroni A. A simple approach for human recombinant apolipoprotein E4 expression and purification. Protein Expr Purif 2011; 79:251-7. [PMID: 21712092 DOI: 10.1016/j.pep.2011.06.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 06/07/2011] [Accepted: 06/13/2011] [Indexed: 10/18/2022]
Abstract
We report a simple expression and purification procedure for the production of recombinant apolipoprotein E4 (apoE4), an important protein for the lipid homeostasis in humans that plays critical roles in the pathogenesis of cardiovascular and neurodegenerative diseases. Our approach is based on the expression of a thioredoxin-apoE4 fusion construct in bacterial cells and subsequent removal of the fused thioredoxin using the highly specific 3C protease, avoiding costly and laborious lipidation-delipidation steps used before. Our approach results in rapid, high-yield production of structurally and functionally competent apoE4 as evidenced by secondary structure measurements, thermal and chemical melting profiles and the kinetic profile of solubilization of dimyristoyl-phosphatidylcholine (DMPC) vesicles. This protocol is appropriate for laboratories with little experience in apolipoprotein biochemistry and will facilitate future studies on the role of apoE4 in the pathogenesis of cardiovascular disease and neurodegenerative diseases, including Alzheimer's disease.
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Affiliation(s)
- Letta Argyri
- Institute of Biology, National Center for Scientific Research Demokritos, Agia Paraskevi, Athens 15310, Greece
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27
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Non-esterified fatty acids generate distinct low-molecular weight amyloid-β (Aβ42) oligomers along pathway different from fibril formation. PLoS One 2011; 6:e18759. [PMID: 21526230 PMCID: PMC3079704 DOI: 10.1371/journal.pone.0018759] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Accepted: 03/09/2011] [Indexed: 12/13/2022] Open
Abstract
Amyloid-β (Aβ) peptide aggregation is known to play a central role in the etiology of Alzheimer’s disease (AD). Among various aggregates, low-molecular weight soluble oligomers of Aβ are increasingly believed to be the primary neurotoxic agents responsible for memory impairment. Anionic interfaces are known to influence the Aβ aggregation process significantly. Here, we report the effects of interfaces formed by medium-chain (C9–C12), saturated non-esterified fatty acids (NEFAs) on Aβ42 aggregation. NEFAs uniquely affected Aβ42 aggregation rates that depended on both the ratio of Aβ:NEFA as well the critical micelle concentration (CMC) of the NEFAs. More importantly, irrespective of the kind of NEFA used, we observed that two distinct oligomers, 12–18 mers and 4–5 mers were formed via different pathway of aggregation under specific experimental conditions: (i) 12–18 mers were generated near the CMC in which NEFAs augment the rate of Aβ42 aggregation towards fibril formation, and, (ii) 4–5 mers were formed above the CMC, where NEFAs inhibit fibril formation. The data indicated that both 12–18 mers and 4–5 mers are formed along an alternate pathway called ‘off-pathway’ that did not result in fibril formation and yet have subtle structural and morphological differences that distinguish their bulk molecular behavior. These observations, (i) reflect the possible mechanism of Aβ aggregation in physiological lipid-rich environments, and (ii) reiterate the fact that all oligomeric forms of Aβ need not be obligatory intermediates of the fibril formation pathway.
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28
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Amyloid β-induced erythrocytic damage and its attenuation by carotenoids. FEBS Lett 2011; 585:1249-54. [PMID: 21459092 DOI: 10.1016/j.febslet.2011.03.060] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 03/23/2011] [Accepted: 03/28/2011] [Indexed: 11/22/2022]
Abstract
The presence of amyloid β-peptide (Aβ) in human blood has recently been established, and it has been hypothesized that Aβ readily contacts red blood cells (RBC) and oxidatively impairs RBC functions. In this study, we conducted in vitro and in vivo studies, which provide evidence that Aβ induces oxidative injury to RBC by binding to them, causing RBC phospholipid peroxidation and diminishing RBC endogenous carotenoids, especially xanthophylls. This type of damage is likely to injure the vasculature, potentially reducing oxygen delivery to the brain and facilitating Alzheimer's disease (AD). As a preventive strategy, because the Aβ-induced RBC damage could be attenuated by treatment of RBC with xanthophylls, we suggest that xanthophylls may contribute to the prevention of AD.
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29
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Aluminum enhances the toxic effects of amyloid β-peptide on cell membranes and a molecular model. MONATSHEFTE FUR CHEMIE 2011. [DOI: 10.1007/s00706-011-0471-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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30
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Butterfield SM, Lashuel HA. Amyloidogenic protein-membrane interactions: mechanistic insight from model systems. Angew Chem Int Ed Engl 2011; 49:5628-54. [PMID: 20623810 DOI: 10.1002/anie.200906670] [Citation(s) in RCA: 474] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The toxicity of amyloid-forming proteins is correlated with their interactions with cell membranes. Binding events between amyloidogenic proteins and membranes result in mutually disruptive structural perturbations, which are associated with toxicity. Membrane surfaces promote the conversion of amyloid-forming proteins into toxic aggregates, and amyloidogenic proteins, in turn, compromise the structural integrity of the cell membrane. Recent studies with artificial model membranes have highlighted the striking resemblance of the mechanisms of membrane permeabilization of amyloid-forming proteins to those of pore-forming toxins and antimicrobial peptides.
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Affiliation(s)
- Sara M Butterfield
- Laboratory of Molecular Neurobiology and Neuroproteomics, Swiss Federal Institute of Technology Lausanne (EPFL), SV-BMI-LMNN AI2351, 1015 Lausanne, Switzerland
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31
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Berthelot K, Lecomte S, Géan J, Immel F, Cullin C. A yeast toxic mutant of HET-s((218-289)) prion displays alternative intermediates of amyloidogenesis. Biophys J 2010; 99:1239-46. [PMID: 20713008 DOI: 10.1016/j.bpj.2010.06.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 06/08/2010] [Accepted: 06/09/2010] [Indexed: 10/19/2022] Open
Abstract
Amyloids are thought to be involved in various types of neurodegenerative disorders. Several kinds of intermediates, differing in morphology, size, and toxicity, have been identified in the multistep amyloidogenesis process. However, the mechanisms explaining amyloid toxicity remain unclear. We previously generated a toxic mutant of the nontoxic HET-s((218-289)) amyloid in yeast. Here we report that toxic and nontoxic amyloids differ not only in their structures but also in their assembling process. We used multiple and complementary methods to investigate the intermediates formed by these two amyloids. With the methods used, no intermediates were observed for the nontoxic amyloid; however, under the same experimental conditions, the toxic mutant displayed visible oligomeric and fibrillar intermediates.
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Affiliation(s)
- Karine Berthelot
- Institut de Biochimie et Génétique Cellulaires, Centre National de la Recherche Scientifique, UMR 5095, Université Bordeaux 2 "Victor Segalen", Bordeaux, France.
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32
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Williams TL, Day IJ, Serpell LC. The effect of Alzheimer's Aβ aggregation state on the permeation of biomimetic lipid vesicles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:17260-8. [PMID: 20923185 DOI: 10.1021/la101581g] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Alzheimer's disease is characterized by the aggregation and deposition of the Aβ peptide. This 40 or 42 residue peptide is the product of the proteolysis of the amyloid precursor protein membrane protein and is able to assemble to form ordered, stable amyloid fibrils as well as small, soluble, and potentially cytotoxic oligomers. The toxicity of the oligomers may be associated with the ability to bind to and affect the integrity of lipid membranes. In this novel work, we have monitored and compared the ability of the potent Aβ42 peptide, the less amyloidogenic Aβ40 peptide, and a variant with reduced amyloidogenicity to bind to and affect the integrity of membranes using dye-filled synthetic vesicles. We reveal that the potency of the assemblies reduces with incubation time of the peptide and that maximal effect occurs when a particular species is apparent by electron microscopy. We have investigated the effect of lipid vesicle composition, and our results suggest that charge on the vesicles is important and that binding may partly be mediated by the GM1 ganglioside receptors expressed in the outer leaflet of vertebrate membranes.
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Affiliation(s)
- Thomas L Williams
- John Maynard Smith Building, School of Life Sciences, University of Sussex, Falmer, East Sussex, BN1 9QG, United Kingdom
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33
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Butterfield S, Lashuel H. Wechselwirkungen zwischen amyloidogenen Proteinen und Membranen: Modellsysteme liefern mechanistische Einblicke. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200906670] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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34
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Ravault S, Flore C, Saurel O, Milon A, Brasseur R, Lins L. Study of the specific lipid binding properties of Abeta 11-22 fragment at endosomal pH. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:10948-10953. [PMID: 19735146 DOI: 10.1021/la901544g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Increasing evidence implicates interactions between Abeta peptide and lipids in the development of Alzheimer's disease. More generally, Abeta peptide interactions with membranes seem to depend on the composition of the lipid bilayer and the structural features of the peptide. One key parameter should be pH, since one site of intracellular Abeta peptide production and/or accumulation is likely to be endosomes. This intracellular endosomal accumulation was suggested to contribute to disease progression. In this paper, we report a study on the 11-22 amphiphilic domain of Abeta in interaction with model membrane; this region contains most of the charged residues of the N-terminal domain of Abeta. We show that the peptide charge, and more precisely the protonation state of histidines 13 and/or 14, is important for the interaction with lipids. Hence, it is only at endosomal pH that a conformational change of the peptide is observed in the presence of negatively charged lipid vesicles, that is, when both lipid headgroups and histidines can interact through electrostatic interactions. Specific interactions of the fragment with phosphatidylserine and to a lesser extent with phosphatidylcholine, but not phosphatidylethanolamine, are further evidenced by the Langmuir monolayer technique. From our results, we suggest that the protonation state of His residues could have a role in the pathogenic surface interaction of the whole Abeta peptide with membranes.
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Affiliation(s)
- S Ravault
- Centre de Biophysique Moléculaire Numérique, Agricultural University of Gembloux, 5030 Gembloux, Belgium
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35
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Reddy AS, Izmitli A, de Pablo JJ. Effect of trehalose on amyloid β (29–40)-membrane interaction. J Chem Phys 2009; 131:085101. [DOI: 10.1063/1.3193726] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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36
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Picone P, Carrotta R, Montana G, Nobile MR, San Biagio PL, Di Carlo M. Abeta oligomers and fibrillar aggregates induce different apoptotic pathways in LAN5 neuroblastoma cell cultures. Biophys J 2009; 96:4200-11. [PMID: 19450490 DOI: 10.1016/j.bpj.2008.11.056] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Accepted: 11/19/2008] [Indexed: 10/20/2022] Open
Abstract
Fibril deposit formation of amyloid beta-protein (Abeta) in the brain is a hallmark of Alzheimer's disease (AD). Increasing evidence suggests that toxicity is linked to diffusible Abeta oligomers, which have been found in soluble brain extracts of AD patients, rather than to insoluble fibers. Here we report a study of the toxicity of two distinct forms of recombinant Abeta small oligomers and fibrillar aggregates to simulate the action of diffusible Abeta oligomers and amyloid plaques on neuronal cells. Different techniques, including dynamic light scattering, fluorescence, and scanning electron microscopy, have been used to characterize the two forms of Abeta. Under similar conditions and comparable incubation times in neuroblastoma LAN5 cell cultures, oligomeric species obtained from Abeta peptide are more toxic than fibrillar aggregates. Both oligomers and aggregates are able to induce neurodegeneration by apoptosis activation, as demonstrated by TUNEL assay and Hoechst staining assays. Moreover, we show that aggregates induce apoptosis by caspase 8 activation (extrinsic pathway), whereas oligomers induce apoptosis principally by caspase 9 activation (intrinsic pathway). These results are confirmed by cytochrome c release, almost exclusively detected in the cytosolic fraction of LAN5 cells treated with oligomers. These findings indicate an active and direct interaction between oligomers and the cellular membrane, and are consistent with internalization of the oligomeric species into the cytosol.
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Affiliation(s)
- Pasquale Picone
- Dipartimento di Chimica e Tecnologie Farmaceutiche, University of Palermo, Palermo, Italy
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37
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Smith PES, Brender JR, Ramamoorthy A. Induction of negative curvature as a mechanism of cell toxicity by amyloidogenic peptides: the case of islet amyloid polypeptide. J Am Chem Soc 2009; 131:4470-8. [PMID: 19278224 PMCID: PMC2665920 DOI: 10.1021/ja809002a] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The death of insulin-producing beta-cells is a key step in the pathogenesis of type 2 diabetes. The amyloidogenic peptide Islet Amyloid Polypeptide (IAPP, also known as amylin) has been shown to disrupt beta-cell membranes leading to beta-cell death. Despite the strong evidence linking IAPP to the destruction of beta-cell membrane integrity and cell death, the mechanism of IAPP toxicity is poorly understood. In particular, the effect of IAPP on the bilayer structure has largely been uncharacterized. In this study, we have determined the effect of the amyloidogenic and toxic hIAPP(1-37) peptide and the nontoxic and nonamyloidogenic rIAPP(1-37) peptide on membranes by a combination of DSC and solid-state NMR spectroscopy. We also characterized the toxic but largely nonamyloidogenic rIAPP(1-19) and hIAPP(1-19) fragments. DSC shows that both amyloidogenic (hIAPP(1-37)) and largely nonamyloidogenic (hIAPP(1-19) and rIAPP(1-19)) toxic versions of the peptide strongly favor the formation of negative curvature in lipid bilayers, while the nontoxic full-length rat IAPP(1-37) peptide does not. This result was confirmed by solid-state NMR spectroscopy which shows that in bicelles composed of regions of high curvature and low curvature, nontoxic rIAPP(1-37) binds to the regions of low curvature while toxic rIAPP(1-19) binds to regions of high curvature. Similarly, solid-state NMR spectroscopy shows that the toxic rIAPP(1-19) peptide significantly disrupts the lipid bilayer structure, whereas the nontoxic rIAPP(1-37) does not have a significant effect. These results indicate IAPP may induce the formation of pores by the induction of excess membrane curvature and can be used to guide the design of compounds that can prevent the cell-toxicity of IAPP. This mechanism may be important to understand the toxicity of other amyloidogenic proteins. Our solid-state NMR results also demonstrate the possibility of using bicelles to measure the affinity of biomolecules for negatively or positively curved regions of the membrane, which we believe will be useful in a variety of biochemical and biophysical investigations related to the cell membrane.
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Affiliation(s)
- Pieter E S Smith
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA
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38
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Florent-Béchard S, Desbène C, Garcia P, Allouche A, Youssef I, Escanyé MC, Koziel V, Hanse M, Malaplate-Armand C, Stenger C, Kriem B, Yen-Potin FT, Olivier JL, Pillot T, Oster T. The essential role of lipids in Alzheimer's disease. Biochimie 2009; 91:804-9. [PMID: 19303044 DOI: 10.1016/j.biochi.2009.03.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Accepted: 03/10/2009] [Indexed: 11/18/2022]
Abstract
In the absence of efficient diagnostic and therapeutic tools, Alzheimer's disease (AD) is a major public health concern due to longer life expectancy in the Western countries. Although the precise cause of AD is still unknown, soluble beta-amyloid (Abeta) oligomers are considered the proximate effectors of the synaptic injury and neuronal death occurring in the early stages of AD. Abeta oligomers may directly interact with the synaptic membrane, leading to impairment of synaptic functions and subsequent signalling pathways triggering neurodegeneration. Therefore, membrane structure and lipid status should be considered determinant factors in Abeta-oligomer-induced synaptic and cell injuries, and therefore AD progression. Numerous epidemiological studies have highlighted close relationships between AD incidence and dietary patterns. Among the nutritional factors involved, lipids significantly influence AD pathogenesis. It is likely that maintenance of adequate membrane lipid content could prevent the production of Abeta peptide as well as its deleterious effects upon its interaction with synaptic membrane, thereby protecting neurons from Abeta-induced neurodegeneration. As major constituents of neuronal lipids, n-3 polyunsaturated fatty acids are of particular interest in the prevention of AD valuable diet ingredients whose neuroprotective properties could be essential for designing preventive nutrition-based strategies. In this review, we discuss the functional relevance of neuronal membrane features with respect to susceptibility to Abeta oligomers and AD pathogenesis, as well as the prospective capacities of lipids to prevent or to delay the disease.
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39
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Zangger K, Gößler R, Khatai L, Lohner K, Jilek A. Structures of the glycine-rich diastereomeric peptides bombinin H2 and H4. Toxicon 2008; 52:246-54. [DOI: 10.1016/j.toxicon.2008.05.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Revised: 04/30/2008] [Accepted: 05/01/2008] [Indexed: 11/26/2022]
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40
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Relationships between the orientation and the structural properties of peptides and their membrane interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:1537-44. [DOI: 10.1016/j.bbamem.2008.04.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2007] [Revised: 04/14/2008] [Accepted: 04/21/2008] [Indexed: 11/17/2022]
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41
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Gordon LM, Nisthal A, Lee AB, Eskandari S, Ruchala P, Jung CL, Waring AJ, Mobley PW. Structural and functional properties of peptides based on the N-terminus of HIV-1 gp41 and the C-terminus of the amyloid-beta protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:2127-37. [PMID: 18515070 DOI: 10.1016/j.bbamem.2008.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 04/07/2008] [Accepted: 05/06/2008] [Indexed: 11/30/2022]
Abstract
Given their high alanine and glycine levels, plaque formation, alpha-helix to beta-sheet interconversion and fusogenicity, FP (i.e., the N-terminal fusion peptide of HIV-1 gp41; 23 residues) and amyloids were proposed as belonging to the same protein superfamily. Here, we further test whether FP may exhibit 'amyloid-like' characteristics, by contrasting its structural and functional properties with those of Abeta(26-42), a 17-residue peptide from the C-terminus of the amyloid-beta protein responsible for Alzheimer's. FTIR spectroscopy, electron microscopy, light scattering and predicted amyloid structure aggregation (PASTA) indicated that aqueous FP and Abeta(26-42) formed similar networked beta-sheet fibrils, although the FP fibril interactions were weaker. FP and Abeta(26-42) both lysed and aggregated human erythrocytes, with the hemolysis-onsets correlated with the conversion of alpha-helix to beta-sheet for each peptide in liposomes. Congo red (CR), a marker of amyloid plaques in situ, similarly inhibited either FP- or Abeta(26-42)-induced hemolysis, and surface plasmon resonance indicated that this may be due to direct CR-peptide binding. These findings suggest that membrane-bound beta-sheets of FP may contribute to the cytopathicity of HIV in vivo through an amyloid-type mechanism, and support the classification of HIV-1 FP as an 'amyloid homolog' (or 'amylog').
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Affiliation(s)
- Larry M Gordon
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
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42
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Nagarajan S, Ramalingam K, Neelakanta Reddy P, Cereghetti DM, Padma Malar EJ, Rajadas J. Lipid-induced conformational transition of the amyloid core fragment Abeta(28-35) and its A30G and A30I mutants. FEBS J 2008; 275:2415-27. [PMID: 18422968 DOI: 10.1111/j.1742-4658.2008.06378.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The interaction of the beta-amyloid peptide (Abeta) with neuronal membranes could play a key role in the pathogenesis of Alzheimer's disease. Recent studies have focused on the interactions of Abeta oligomers to explain the neuronal toxicity accompanying Alzheimer's disease. In our study, we have investigated the role of lipid interactions with soluble Abeta(28-35) (wild-type) and its mutants A30G and A30I in their aggregation and conformational preferences. CD and Trp fluorescence spectroscopic studies indicated that, immediately on dissolution, these peptides adopted a random coil structure. Upon addition of negatively charged 1,2-dipalmitoyl-syn-glycero-3-phospho-rac-(glycerol) sodium salt (PG) lipid, the wild-type and A30I mutant underwent reorganization into a predominant beta-sheet structure. However, no conformational changes were observed in the A30G mutant on interaction with PG. In contrast, the presence of zwitterionic 1,2-dipalmitoyl-syn-glycero-3-phosphatidylcholine (PC) lipid had no effect on the conformation of these three peptides. These observations were also confirmed with atomic force microscopy and the thioflavin-T assay. In the presence of PG vesicles, both the wild-type and A30I mutant formed fibrillar structures within 2 days of incubation in NaCl/P(i), but not in their absence. Again, no oligomerization was observed with PC vesicles. The Trp studies also revealed that both ends of the three peptides are not buried deep in the vesicle membrane. Furthermore, fluorescence spectroscopy using the environment-sensitive probe 1,6-diphenyl-1,3,5-hexatriene showed an increase in the membrane fluidity upon exposure of the vesicles to the peptides. The latter effect may result from the lipid head group interactions with the peptides. Fluorescence resonance energy transfer experiments revealed that these peptides undergo a random coil-to-sheet conversion in solution on aging and that this process is accelerated by negatively charged lipid vesicles. These results indicate that aggregation depends on hydrophobicity and propensity to form beta-sheets of the amyloid peptide, and thus offer new insights into the mechanism of amyloid neurodegenerative disease.
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Affiliation(s)
- Sureshbabu Nagarajan
- Bio-Organic and Neurochemistry Laboratory, Central Leather Research Institute, Adyar, Chennai, India
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43
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Lins L, Brasseur R. Tilted peptides: a structural motif involved in protein membrane insertion? J Pept Sci 2008; 14:416-22. [DOI: 10.1002/psc.971] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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44
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Lorin A, Lins L, Stroobant V, Brasseur R, Charloteaux B. The minimal fusion peptide of simian immunodeficiency virus corresponds to the 11 first residues of gp32. J Pept Sci 2007; 14:423-8. [DOI: 10.1002/psc.949] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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45
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Crowet JM, Lins L, Dupiereux I, Elmoualija B, Lorin A, Charloteaux B, Stroobant V, Heinen E, Brasseur R. Tilted properties of the 67-78 fragment of alpha-synuclein are responsible for membrane destabilization and neurotoxicity. Proteins 2007; 68:936-47. [PMID: 17554782 DOI: 10.1002/prot.21483] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Alpha-synuclein is a 140 residue protein associated with Parkinson's disease. Intraneural inclusions called Lewy bodies and Lewy neurites are mainly composed of alpha-synuclein aggregated into amyloid fibrils. Other amyloidogenic proteins, such as the beta amyloid peptide involved in Alzheimer's disease and the prion protein (PrP) associated with Creuztfeldt-Jakob's disease, are known to possess "tilted peptides". These peptides are short protein fragments that adopt an oblique orientation at a hydrophobic/hydrophilic interface, which enables destabilization of the membranes. In this paper, sequence analysis and molecular modelling predict that the 67-78 fragment of alpha-synuclein is a tilted peptide. Its destabilizing properties were tested experimentally. The alpha-synuclein 67-78 peptide is able to induce lipid mixing and leakage of unilamellar liposomes. The neuronal toxicity, studied using human neuroblastoma cells, demonstrated that the alpha-synuclein 67-78 peptide induces neurotoxicity. A mutant designed by molecular modelling to be amphipathic was shown to be significantly less fusogenic and toxic than the wild type. In conclusion, we have identified a tilted peptide in alpha-synuclein, which could be involved in the toxicity induced during amyloidogenesis of alpha-synuclein.
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Affiliation(s)
- Jean-Marc Crowet
- Gembloux Agricultural University, Centre de Biophysique Moléculaire Numérique, 2 Passage des Déportés, B-5030 Gembloux, Belgium.
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46
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Rocha S, Pereira MC, Coelho MAN, Möhwald H, Brezesinski G. Adsorption of the fusogenic peptide B18 onto solid surfaces: insights into the mechanism of peptide assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:5022-8. [PMID: 17391050 DOI: 10.1021/la0628120] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The adsorption and assembly of B18 peptide on various solid surfaces were studied by reflectometry techniques and atomic force microscopy. B18 is the minimal membrane binding and fusogenic motif of the sea urchin protein bindin, which mediates the fertilization process. Silicon substrates were modified to obtain hydrophilic charged surfaces (oxide layer and polyelectrolyte multilayers) and hydrophobic surfaces (octadecyltrichlorosilane). B18 does not adsorb on hydrophilic positively charged surfaces, which was attributed to electrostatic repulsion since the peptide is positively charged. In contrast, the peptide irreversibly adsorbs on negatively charged hydrophilic as well as on hydrophobic surfaces. B18 showed higher affinity for hydrophobic surfaces than for hydrophilic negatively charged surfaces, which must be due to the presence of hydrophobic side chains at both ends of the molecule. Atomic force microscopy provided the indication that lateral diffusion on the surface affects the adsorption process of B18 on hydrophobic surfaces. The adsorption of the peptide on negatively charged surfaces was characterized by the formation of globular clusters.
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Affiliation(s)
- Sandra Rocha
- Max Planck Institute of Colloids and Interfaces, Research Campus Golm, Am Mühlenberg 1, D-14476 Potsdam, Germany
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47
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Youssef I, Florent-Béchard S, Malaplate-Armand C, Koziel V, Bihain B, Olivier JL, Leininger-Muller B, Kriem B, Oster T, Pillot T. N-truncated amyloid-beta oligomers induce learning impairment and neuronal apoptosis. Neurobiol Aging 2007; 29:1319-33. [PMID: 17459527 DOI: 10.1016/j.neurobiolaging.2007.03.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 02/23/2007] [Accepted: 03/04/2007] [Indexed: 01/09/2023]
Abstract
N-terminal-truncated forms of amyloid-beta (A beta) peptide have been recently suggested to play a pivotal role early in Alzheimer's disease (AD). Among them, A beta 3(pE)-42 peptide, starting with pyroglutamyl at residue Glu-3, is considered as the predominant A beta species in AD plaques and pre-amyloid lesions. Its abundance is reported to be directly proportional to the severity of the clinical phenotype. The present study investigates the effects of soluble oligomeric A beta 3(pE)-42 after intracerebroventricular injection on mice learning ability and the molecular mechanisms of its in vitro neurotoxicity. Mice injected with soluble A beta 3(pE)-42 or A beta(l-42) displayed impaired spatial working memory and delayed memory acquisition in Y-maze and Morris water maze tests, while those injected with soluble A beta(42-1) showed no effect. These cognitive alterations were associated with free radical overproduction in the hippocampus and olfactory bulbs, but not in the cerebral cortex or cerebellum. In vitro, A beta 3(pE)-42 oligomers induced a redox-sensitive neuronal apoptosis involving caspase activation and an arachidonic acid-dependent pro-inflammatory pathway. These data suggest that A beta 3(pE)-42 could mediate the neurodegenerative process and subsequent cognitive alteration occurring in preclinical AD stages.
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Affiliation(s)
- Ihsen Youssef
- Lipidomix, JE 2482, INPL, Laboratoire de Médecine et Thérapeutique Moléculaire, 15 rue du Bois de la Champelle, 54505 Vandoeuvre-lès-Nancy, France
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48
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Patton RL, Kalback WM, Esh CL, Kokjohn TA, Van Vickle GD, Luehrs DC, Kuo YM, Lopez J, Brune D, Ferrer I, Masliah E, Newel AJ, Beach TG, Castaño EM, Roher AE. Amyloid-beta peptide remnants in AN-1792-immunized Alzheimer's disease patients: a biochemical analysis. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 169:1048-63. [PMID: 16936277 PMCID: PMC1698828 DOI: 10.2353/ajpath.2006.060269] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Experiments with amyloid-beta (Abeta)-42-immunized transgenic mouse models of Alzheimer's disease have revealed amyloid plaque disruption and apparent cognitive function recovery. Neuropathological examination of patients vaccinated against purified Abeta-42 (AN-1792) has demonstrated that senile plaque disruption occurred in immunized humans as well. Here, we examined tissue histology and quantified and biochemically characterized the remnant amyloid peptides in the gray and white matter and leptomeningeal/cortical vessels of two AN-1792-vaccinated patients, one of whom developed meningoencephalitis. Compact core and diffuse amyloid deposits in both vaccinated individuals were focally absent in some regions. Although parenchymal amyloid was focally disaggregated, vascular deposits were relatively preserved or even increased. Immunoassay revealed that total soluble amyloid levels were sharply elevated in vaccinated patient gray and white matter compared with Alzheimer's disease cases. Our experiments suggest that although immunization disrupted amyloid deposits, vascular capture prevented large-scale egress of Abeta peptides. Trapped, solubilized amyloid peptides may ultimately have cascading toxic effects on cerebrovascular, gray and white matter tissues. Anti-amyloid immunization may be most effective not as therapeutic or mitigating measures but as a prophylactic measure when Abeta deposition is still minimal. This may allow Abeta mobilization under conditions in which drainage and degradation of these toxic peptides is efficient.
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Affiliation(s)
- R Lyle Patton
- The Longtine Center for Molecular Biology and Genetics, W.H. Civin Laboratory for Neuropathology, M.D. Sun Health Research Institute, 10515 W. Santa Fe Dr., Sun City, AZ 85351, USA
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49
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Nguyen NQN, Tabruyn SP, Lins L, Lion M, Cornet AM, Lair F, Rentier-Delrue F, Brasseur R, Martial JA, Struman I. Prolactin/growth hormone-derived antiangiogenic peptides highlight a potential role of tilted peptides in angiogenesis. Proc Natl Acad Sci U S A 2006; 103:14319-24. [PMID: 16973751 PMCID: PMC1599962 DOI: 10.1073/pnas.0606638103] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Angiogenesis is a crucial step in many pathologies, including tumor growth and metastasis. Here, we show that tilted peptides exert antiangiogenic activity. Tilted (or oblique-oriented) peptides are short peptides known to destabilize membranes and lipid cores and characterized by an asymmetric distribution of hydrophobic residues along the axis when helical. We have previously shown that 16-kDa fragments of the human prolactin/growth hormone (PRL/GH) family members are potent angiogenesis inhibitors. Here, we demonstrate that all these fragments possess a 14-aa sequence having the characteristics of a tilted peptide. The tilted peptides of human prolactin and human growth hormone induce endothelial cell apoptosis, inhibit endothelial cell proliferation, and inhibit capillary formation both in vitro and in vivo. These antiangiogenic effects are abolished when the peptides' hydrophobicity gradient is altered by mutation. We further demonstrate that the well known tilted peptides of simian immunodeficiency virus gp32 and Alzheimer's beta-amyloid peptide are also angiogenesis inhibitors. Taken together, these results point to a potential new role for tilted peptides in regulating angiogenesis.
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Affiliation(s)
- Ngoc-Quynh-Nhu Nguyen
- Laboratory of Molecular Biology and Genetic Engineering, Center of Biomedical Integrative Genoproteomics, University of Liège, B-4000 Liège, Belgium; and
| | - Sebastien P. Tabruyn
- Laboratory of Molecular Biology and Genetic Engineering, Center of Biomedical Integrative Genoproteomics, University of Liège, B-4000 Liège, Belgium; and
| | - Laurence Lins
- Center of Numerical Molecular Biophysic, Gembloux Agricultural University, B-5030 Gembloux, Belgium
| | - Michelle Lion
- Laboratory of Molecular Biology and Genetic Engineering, Center of Biomedical Integrative Genoproteomics, University of Liège, B-4000 Liège, Belgium; and
| | - Anne M. Cornet
- Laboratory of Molecular Biology and Genetic Engineering, Center of Biomedical Integrative Genoproteomics, University of Liège, B-4000 Liège, Belgium; and
| | - Florence Lair
- Laboratory of Molecular Biology and Genetic Engineering, Center of Biomedical Integrative Genoproteomics, University of Liège, B-4000 Liège, Belgium; and
| | - Francoise Rentier-Delrue
- Laboratory of Molecular Biology and Genetic Engineering, Center of Biomedical Integrative Genoproteomics, University of Liège, B-4000 Liège, Belgium; and
| | - Robert Brasseur
- Center of Numerical Molecular Biophysic, Gembloux Agricultural University, B-5030 Gembloux, Belgium
| | - Joseph A. Martial
- Laboratory of Molecular Biology and Genetic Engineering, Center of Biomedical Integrative Genoproteomics, University of Liège, B-4000 Liège, Belgium; and
| | - Ingrid Struman
- Laboratory of Molecular Biology and Genetic Engineering, Center of Biomedical Integrative Genoproteomics, University of Liège, B-4000 Liège, Belgium; and
- To whom correspondence should be addressed at:
Laboratory of Molecular Biology and Genetic Engineering, Center of Biomedical Integrative Genoproteomics, University of Liège, B6, Allée du 6 Août, B-4000, Sart Tilman, Belgium. E-mail:
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50
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Tamaki C, Ohtsuki S, Iwatsubo T, Hashimoto T, Yamada K, Yabuki C, Terasaki T. Major involvement of low-density lipoprotein receptor-related protein 1 in the clearance of plasma free amyloid beta-peptide by the liver. Pharm Res 2006; 23:1407-16. [PMID: 16779710 DOI: 10.1007/s11095-006-0208-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Accepted: 02/08/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE To identify the molecules responsible for amyloid beta-peptide (1-40) (Abeta(1-40)) uptake by the liver, which play a major role in the systemic clearance of Abeta(1-40). METHODS The liver uptake index method was used to examine the mechanisms of Abeta(1-40) uptake by the liver in vivo. RESULTS [125I]Abeta(1-40) uptake by the rat liver was concentration-dependent (50% saturation concentration = 302 nM). The inhibitory spectrum of Abeta fragments indicated that 17-24 in Abeta (LVFFAEDV) was the putative sequence responsible for hepatic Abeta(1-40) uptake. Receptor-associated protein (RAP) inhibited [125I]Abeta(1-40) uptake by 48%. RAP-deficient mice, in which low-density lipoprotein receptor-related protein 1 (LRP-1) expression was suppressed, showed a 46% reduction in [125I]Abeta(1-40) uptake by the liver. siRNA-mediated suppression of LRP-1 expression in the liver resulted in a reduction in [125I]Abeta(1-40) uptake by 64%. Both the expression of LRP-1 in the liver and the hepatic Abeta(1-40) uptake were significantly reduced in 13-month-old rats compared with 7-week-old rats. CONCLUSIONS LRP-1 is the major receptor responsible for the saturable uptake of plasma free Abeta(1-40) by the liver. Reduction of LRP-1 expression will play a role in the age-related reduction in hepatic Abeta(1-40) clearance.
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Affiliation(s)
- Chihiro Tamaki
- Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan
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