1
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Teng X, Stefaniak E, Willison KR, Ying L. Interplay between Copper, Phosphatidylserine, and α-Synuclein Suggests a Link between Copper Homeostasis and Synaptic Vesicle Cycling. ACS Chem Neurosci 2024; 15:2884-2896. [PMID: 39013013 PMCID: PMC11311125 DOI: 10.1021/acschemneuro.4c00280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Revised: 06/14/2024] [Accepted: 07/02/2024] [Indexed: 07/18/2024] Open
Abstract
Copper homeostasis is critical to the functioning of the brain, and its breakdown is linked with many brain diseases. Copper is also known to interact with the negatively charged lipid, phosphatidylserine (PS), as well as α-synuclein, an aggregation-prone protein enriched in the synapse, which plays a role in synaptic vesicle docking and fusion. However, the interplay between copper, PS lipid, and α-synuclein is not known. Herein, we report a detailed and predominantly kinetic study of the interactions among these three components pertinent to copper homeostasis and neurotransmission. We found that synaptic vesicle-mimicking small unilamellar vesicles (SUVs) can sequester any excess free Cu2+ within milliseconds, and bound Cu2+ on SUVs can be reduced to Cu+ by GSH at a nearly constant rate under physiological conditions. Moreover, we revealed that SUV-bound Cu2+ does not affect the binding between wild-type α-synuclein and SUVs but affect that between N-terminal acetylated α-synuclein and SUVs. In contrast, Cu2+ can effectively displace both types of α-synuclein from the vesicles. Our results suggest that synaptic vesicles may mediate copper transfer in the brain, while copper could participate in synaptic vesicle docking to the plasma membrane via its regulation of the interaction between α-synuclein and synaptic vesicle.
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Affiliation(s)
- Xiangyu Teng
- Department
of Chemistry, Imperial College London, Molecular
Sciences Research Hub, 82 Wood Lane, London W12
0BZ, U.K.
| | - Ewelina Stefaniak
- National
Heart and Lung Institute, Imperial College
London, Molecular Sciences Research Hub, 82 Wood Lane, London W12 0BZ, U.K.
| | - Keith R. Willison
- Department
of Chemistry, Imperial College London, Molecular
Sciences Research Hub, 82 Wood Lane, London W12
0BZ, U.K.
| | - Liming Ying
- National
Heart and Lung Institute, Imperial College
London, Molecular Sciences Research Hub, 82 Wood Lane, London W12 0BZ, U.K.
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2
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Gromadzka G, Wilkaniec A, Tarnacka B, Hadrian K, Bendykowska M, Przybyłkowski A, Litwin T. The Role of Glia in Wilson's Disease: Clinical, Neuroimaging, Neuropathological and Molecular Perspectives. Int J Mol Sci 2024; 25:7545. [PMID: 39062788 PMCID: PMC11276698 DOI: 10.3390/ijms25147545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 07/07/2024] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
Wilson's disease (WD) is inherited in an autosomal recessive manner and is caused by pathogenic variants of the ATP7B gene, which are responsible for impaired copper transport in the cell, inhibition of copper binding to apoceruloplasmin, and biliary excretion. This leads to the accumulation of copper in the tissues. Copper accumulation in the CNS leads to the neurological and psychiatric symptoms of WD. Abnormalities of copper metabolism in WD are associated with impaired iron metabolism. Both of these elements are redox active and may contribute to neuropathology. It has long been assumed that among parenchymal cells, astrocytes have the greatest impact on copper and iron homeostasis in the brain. Capillary endothelial cells are separated from the neuropil by astrocyte terminal legs, putting astrocytes in an ideal position to regulate the transport of iron and copper to other brain cells and protect them if metals breach the blood-brain barrier. Astrocytes are responsible for, among other things, maintaining extracellular ion homeostasis, modulating synaptic transmission and plasticity, obtaining metabolites, and protecting the brain against oxidative stress and toxins. However, excess copper and/or iron causes an increase in the number of astrocytes and their morphological changes observed in neuropathological studies, as well as a loss of the copper/iron storage function leading to macromolecule peroxidation and neuronal loss through apoptosis, autophagy, or cuproptosis/ferroptosis. The molecular mechanisms explaining the possible role of glia in copper- and iron-induced neurodegeneration in WD are largely understood from studies of neuropathology in Parkinson's disease and Alzheimer's disease. Understanding the mechanisms of glial involvement in neuroprotection/neurotoxicity is important for explaining the pathomechanisms of neuronal death in WD and, in the future, perhaps for developing more effective diagnostic/treatment methods.
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Affiliation(s)
- Grażyna Gromadzka
- Department of Biomedical Sciences, Faculty of Medicine, Collegium Medicum, Cardinal Stefan Wyszynski University, Wóycickiego 1/3, 01-938 Warsaw, Poland
| | - Anna Wilkaniec
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego St., 02-106 Warsaw, Poland
| | - Beata Tarnacka
- Department of Rehabilitation, Medical University of Warsaw, Spartańska 1, 02-637 Warsaw, Poland
| | - Krzysztof Hadrian
- Department of Gastroenterology and Internal Medicine, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland (A.P.)
| | - Maria Bendykowska
- Students Scientific Association “Immunis”, Cardinal Stefan Wyszynski University, Dewajtis 5, 01-815 Warsaw, Poland
| | - Adam Przybyłkowski
- Department of Gastroenterology and Internal Medicine, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland (A.P.)
| | - Tomasz Litwin
- Second Department of Neurology, Institute of Psychiatry and Neurology, Sobieskiego 9, 02-957 Warsaw, Poland
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3
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Bjørklund G, Oliinyk P, Khavrona O, Lozynska I, Lysiuk R, Darmohray R, Antonyak H, Dub N, Zayachuk V, Antoniv O, Rybak O, Peana M. The Effects of Fisetin and Curcumin on Oxidative Damage Caused by Transition Metals in Neurodegenerative Diseases. Mol Neurobiol 2024:10.1007/s12035-024-04321-2. [PMID: 38970766 DOI: 10.1007/s12035-024-04321-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 06/19/2024] [Indexed: 07/08/2024]
Abstract
Neurodegenerative diseases pose a significant health challenge for the elderly. The escalating presence of toxic metals and chemicals in the environment is a potential contributor to central nervous system dysfunction and the onset of neurodegenerative conditions. Transition metals play a crucial role in various pathophysiological mechanisms associated with prevalent neurodegenerative diseases such as Alzheimer's and Parkinson's. Given the ubiquitous exposure to metals from diverse sources in everyday life, the workplace, and the environment, most of the population faces regular contact with different forms of these metals. Disturbances in the levels and homeostasis of certain transition metals are closely linked to the manifestation of neurodegenerative disorders. Oxidative damage further exacerbates the progression of neurological consequences. Presently, there exists no curative therapy for individuals afflicted by neurodegenerative diseases, with treatment approaches primarily focusing on alleviating pathological symptoms. Within the realm of biologically active compounds derived from plants, flavonoids and curcuminoids stand out for their extensively documented antioxidant, antiplatelet, and neuroprotective properties. The utilization of these compounds holds the potential to formulate highly effective therapeutic strategies for managing neurodegenerative diseases. This review provides a comprehensive overview of the impact of abnormal metal levels, particularly copper, iron, and zinc, on the initiation and progression of neurodegenerative diseases. Additionally, it aims to elucidate the potential of fisetin and curcumin to inhibit or decelerate the neurodegenerative process.
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Affiliation(s)
- Geir Bjørklund
- Council for Nutritional and Environmental Medicine (CONEM), Toften 24, 8610, Mo I Rana, Norway.
| | - Petro Oliinyk
- Department of Disaster Medicine and Military Medicine, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
- CONEM Ukraine Life Science Research Group, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
| | - Oksana Khavrona
- CONEM Ukraine Life Science Research Group, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
- Department of Biological Chemistry, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
| | - Iryna Lozynska
- CONEM Ukraine Life Science Research Group, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
- Department of Biological Chemistry, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
| | - Roman Lysiuk
- CONEM Ukraine Life Science Research Group, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
- Department of Pharmacognosy and Botany, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
| | - Roman Darmohray
- CONEM Ukraine Life Science Research Group, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
- Department of Pharmacognosy and Botany, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
| | - Halyna Antonyak
- Department of Ecology, Ivan Franko National University of Lviv, Lviv, 79005, Ukraine
| | - Natalia Dub
- Andrei Krupynskyi Lviv Medical Academy, Lviv, 79000, Ukraine
| | - Vasyl Zayachuk
- Department of Botany, Ukrainian National Forestry University, Wood Science and Non-Wood Forest Products, Lviv, 79057, Ukraine
| | - Olha Antoniv
- CONEM Ukraine Life Science Research Group, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
- Department of Pharmacology, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
| | - Oksana Rybak
- CONEM Ukraine Life Science Research Group, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
- Department of Pharmacognosy and Botany, Danylo Halytsky Lviv National Medical University, Lviv, 79010, Ukraine
| | - Massimiliano Peana
- Department of Chemical, Physical, Mathematical and Natural Sciences, University of Sassari, 07100, Sassari, Italy.
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4
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Cukierman DS, Bodnár N, Diniz R, Nagy L, Kállay C, Rey NA. Full Equilibrium Picture in Aqueous Binary and Ternary Systems Involving Copper(II), 1-Methylimidazole-Containing Hydrazonic Ligands, and the 103-112 Human Prion Protein Fragment. Inorg Chem 2022; 61:723-737. [PMID: 34918515 DOI: 10.1021/acs.inorgchem.1c03598] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work, we describe two novel 1-methylimidazole N-acylhydyrazonic ligands and their interaction with copper(II) in solution. Binary systems constituted by each of these hydrazones and the metal ion were studied by potentiometric titrations. The magnitude of their affinities for zinc(II) was also determined for the sake of comparison. Additionally, a full evaluation of the copper(II) chelation profile of the new ligands in ternary systems containing a human prion protein fragment was performed. Mixed ligand complexes comprising the HuPrP103-112 fragment, copper(II) ions, and an N-acylhydrazone were characterized by potentiometry, ultraviolet-visible spectroscopy, and circular dichroism. Some of these species were also identified by electrospray ionization mass spectrometry and unequivocally assigned through their isotopic distribution pattern. To the best of our knowledge, this is the first report concerning the stability of ternary complexes involving a hydrazonic metal-protein interaction modulator, copper, and a peptide. The ability of N-acylhydrazones to prevent peptide oxidation was also examined. Both ligands can partially prevent the formation of the doubly oxidized product, a process mediated by copper(II) ions. Oxidative stress is considered an important hallmark of neurodegenerative diseases such as prion-related spongiform encephalopathies. In this context, active intervention with respect to the deleterious copper-catalyzed methionine oxidation could represent an interesting therapeutic approach.
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Affiliation(s)
- Daphne S Cukierman
- Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro 22451-900, Brazil
| | - Nikolett Bodnár
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen 4032, Hungary
| | - Renata Diniz
- Department of Chemistry, ICEx, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil
| | - Lajos Nagy
- Department of Applied Chemistry, University of Debrecen, Debrecen 4032, Hungary
| | - Csilla Kállay
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen 4032, Hungary
| | - Nicolás A Rey
- Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro 22451-900, Brazil
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5
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Kotuniak R, Bal W. Kinetics of Cu(II) complexation by ATCUN/NTS and related peptides: a gold mine of novel ideas for copper biology. Dalton Trans 2021; 51:14-26. [PMID: 34816848 DOI: 10.1039/d1dt02878b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cu(II)-peptide complexes are intensely studied as models for biological peptides and proteins and for their direct importance in copper homeostasis and dyshomeostasis in human diseases. In particular, high-affinity ATCUN/NTS (amino-terminal copper and nickel/N-terminal site) motifs present in proteins and peptides are considered as Cu(II) transport agents for copper delivery to cells. The information on the affinities and structures of such complexes derived from steady-state methods appears to be insufficient to resolve the mechanisms of copper trafficking, while kinetic studies have recently shown promise in explaining them. Stopped-flow experiments of Cu(II) complexation to ATCUN/NTS peptides revealed the presence of reaction steps with rates much slower than the diffusion limit due to the formation of novel intermediate species. Herein, the state of the field in Cu(II)-peptide kinetics is reviewed in the context of physiological data, leading to novel ideas in copper biology, together with the discussion of current methodological issues.
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Affiliation(s)
- Radosław Kotuniak
- Institute of Biochemistry and Biophysics, Polish Academy of Science, Pawińskiego 5a, 02-106 Warsaw, Poland.
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics, Polish Academy of Science, Pawińskiego 5a, 02-106 Warsaw, Poland.
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6
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Pal A, Rani I, Pawar A, Picozza M, Rongioletti M, Squitti R. Microglia and Astrocytes in Alzheimer's Disease in the Context of the Aberrant Copper Homeostasis Hypothesis. Biomolecules 2021; 11:1598. [PMID: 34827595 PMCID: PMC8615684 DOI: 10.3390/biom11111598] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 10/09/2021] [Accepted: 10/22/2021] [Indexed: 12/24/2022] Open
Abstract
Evidence of copper's (Cu) involvement in Alzheimer's disease (AD) is available, but information on Cu involvement in microglia and astrocytes during the course of AD has yet to be structurally discussed. This review deals with this matter in an attempt to provide an updated discussion on the role of reactive glia challenged by excess labile Cu in a wide picture that embraces all the major processes identified as playing a role in toxicity induced by an imbalance of Cu in AD.
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Affiliation(s)
- Amit Pal
- Department of Biochemistry, AIIMS, Kalyani 741245, West Bengal, India
| | - Isha Rani
- Department of Biochemistry, Maharishi Markandeshwar Institute of Medical Sciences and Research (MMIMSR), Maharishi Markandeshwar University (MMU), Mullana, Ambala 133207, Haryana, India;
| | - Anil Pawar
- Department of Zoology, DAV University, Jalandhar 144012, Punjab, India;
| | - Mario Picozza
- Neuroimmunology Unit, IRCSS Fondazione Santa Lucia, 00143 Rome, Italy;
| | - Mauro Rongioletti
- Department of Laboratory Medicine, Research and Development Division, San Giovanni Calibita Fatebenefratelli Hospital, Isola Tiberina, 00186 Rome, Italy;
| | - Rosanna Squitti
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, 25125 Brescia, Italy
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7
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Tabbì G, Cucci LM, Pinzino C, Munzone A, Marzo T, Pizzanelli S, Satriano C, Magrì A, La Mendola D. Peptides Derived from Angiogenin Regulate Cellular Copper Uptake. Int J Mol Sci 2021; 22:9530. [PMID: 34502439 PMCID: PMC8430698 DOI: 10.3390/ijms22179530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/26/2021] [Accepted: 08/31/2021] [Indexed: 12/31/2022] Open
Abstract
The angiogenin protein (ANG) is one of the most potent endogenous angiogenic factors. In this work we characterized by means of potentiometric, spectroscopic and voltammetric techniques, the copper complex species formed with peptide fragments derived from the N-terminal domain of the protein, encompassing the sequence 1-17 and having free amino, Ang1-17, or acetylated N-terminus group, AcAng1-17, so to explore the role of amino group in metal binding and cellular copper uptake. The obtained data show that amino group is the main copper anchoring site for Ang1-17. The affinity constant values, metal coordination geometry and complexes redox-potentials strongly depend, for both peptides, on the number of copper equivalents added. Confocal laser scanning microscope analysis on neuroblastoma cells showed that in the presence of one equivalent of copper ion, the free amino Ang1-17 increases cellular copper uptake while the acetylated AcAng1-17 strongly decreases the intracellular metal level. The activity of peptides was also compared to that of the protein normally present in the plasma (wtANG) as well as to the recombinant form (rANG) most commonly used in literature experiments. The two protein isoforms bind copper ions but with a different coordination environment. Confocal laser scanning microscope data showed that the wtANG induces a strong increase in intracellular copper compared to control while the rANG decreases the copper signal inside cells. These data demonstrate the relevance of copper complexes' geometry to modulate peptides' activity and show that wtANG, normally present in the plasma, can affect cellular copper uptake.
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Affiliation(s)
- Giovanni Tabbì
- Institute of Crystallography—National Council of Research—CNR, via Paolo Gaifami 18, 95126 Catania, Italy;
| | - Lorena Maria Cucci
- Nano Hybrid BioInterfaces Lab (NHBIL), Department of Chemical Sciences, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy;
| | - Calogero Pinzino
- Institute for the Chemistry of OrganoMetallic Compounds (ICCOM), National Council of Research—CNR, via G. Moruzzi 1, 56124 Pisa, Italy;
| | - Alessia Munzone
- Aix-Marseille Univesité, 52 Avenue Escadrille Normandie Niemen, 13013 Marseille, France;
| | - Tiziano Marzo
- Department of Pharmacy, University of Pisa, via Bonanno Pisano 6, 56126 Pisa, Italy;
| | - Silvia Pizzanelli
- Institute for the Chemistry of OrganoMetallic Compounds (ICCOM), National Council of Research—CNR, via G. Moruzzi 1, 56124 Pisa, Italy;
| | - Cristina Satriano
- Nano Hybrid BioInterfaces Lab (NHBIL), Department of Chemical Sciences, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy;
| | - Antonio Magrì
- Institute of Crystallography—National Council of Research—CNR, via Paolo Gaifami 18, 95126 Catania, Italy;
| | - Diego La Mendola
- Department of Pharmacy, University of Pisa, via Bonanno Pisano 6, 56126 Pisa, Italy;
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8
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Oxidase Reactivity of Cu II Bound to N-Truncated Aβ Peptides Promoted by Dopamine. Int J Mol Sci 2021; 22:ijms22105190. [PMID: 34068879 PMCID: PMC8155989 DOI: 10.3390/ijms22105190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/10/2021] [Accepted: 05/12/2021] [Indexed: 12/18/2022] Open
Abstract
The redox chemistry of copper(II) is strongly modulated by the coordination to amyloid-β peptides and by the stability of the resulting complexes. Amino-terminal copper and nickel binding motifs (ATCUN) identified in truncated Aβ sequences starting with Phe4 show very high affinity for copper(II) ions. Herein, we study the oxidase activity of [Cu–Aβ4−x] and [Cu–Aβ1−x] complexes toward dopamine and other catechols. The results show that the CuII–ATCUN site is not redox-inert; the reduction of the metal is induced by coordination of catechol to the metal and occurs through an inner sphere reaction. The generation of a ternary [CuII–Aβ–catechol] species determines the efficiency of the oxidation, although the reaction rate is ruled by reoxidation of the CuI complex. In addition to the N-terminal coordination site, the two vicinal histidines, His13 and His14, provide a second Cu-binding motif. Catechol oxidation studies together with structural insight from the mixed dinuclear complexes Ni/Cu–Aβ4−x reveal that the His-tandem is able to bind CuII ions independently of the ATCUN site, but the N-terminal metal complexation reduces the conformational mobility of the peptide chain, preventing the binding and oxidative reactivity toward catechol of CuII bound to the secondary site.
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9
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Stefaniak E, Pushie MJ, Vaerewyck C, Corcelli D, Griggs C, Lewis W, Kelley E, Maloney N, Sendzik M, Bal W, Haas KL. Exploration of the Potential Role for Aβ in Delivery of Extracellular Copper to Ctr1. Inorg Chem 2020; 59:16952-16966. [PMID: 33211469 DOI: 10.1021/acs.inorgchem.0c02100] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amyloid beta (Aβ) peptides are notorious for their involvement in Alzheimer's disease (AD), by virtue of their propensity to aggregate to form oligomers, fibrils, and eventually plaques in the brain. Nevertheless, they appear to be essential for correct neurophysiology on the synaptic level and may have additional functions including antimicrobial activity, sealing the blood-brain barrier, promotion of recovery from brain injury, and even tumor suppression. Aβ peptides are also avid copper chelators, and coincidentally copper is significantly dysregulated in the AD brain. Copper (Cu) is released in significant amounts during calcium signaling at the synaptic membrane. Aβ peptides may have a role in maintaining synaptic Cu homeostasis, including as a scavenger for redox-active Cu and as a chaperone for clearing Cu from the synaptic cleft. Here, we employed the Aβ1-16 and Aβ4-16 peptides as well-established non-aggregating models of major Aβ species in healthy and AD brains, and the Ctr1-14 peptide as a model for the extracellular domain of the human cellular copper transporter protein (Ctr1). With these model peptides and a number of spectroscopic techniques, we investigated whether the Cu complexes of Aβ peptides could provide Ctr1 with either Cu(II) or Cu(I). We found that Aβ1-16 fully and rapidly delivered Cu(II) to Ctr1-14 along the affinity gradient. Such delivery was only partial for the Aβ4-16/Ctr1-14 pair, in agreement with the higher complex stability for the former peptide. Moreover, the reaction was very slow and took ca. 40 h to reach equilibrium under the given experimental conditions. In either case of Cu(II) exchange, no intermediate (ternary) species were present in detectable amounts. In contrast, both Aβ species released Cu(I) to Ctr1-14 rapidly and in a quantitative fashion, but ternary intermediate species were detected in the analysis of XAS data. The results presented here are the first direct evidence of a Cu(I) and Cu(II) transfer between the human Ctr1 and Aβ model peptides. These results are discussed in terms of the fundamental difference between the peptides' Cu(II) complexes (pleiotropic ensemble of open structures of Aβ1-16 vs the rigid closed-ring system of amino-terminal Cu/Ni binding Aβ4-16) and the similarity of their Cu(I) complexes (both anchored at the tandem His13/His14, bis-His motif). These results indicate that Cu(I) may be more feasible than Cu(II) as the cargo for copper clearance from the synaptic cleft by Aβ peptides and its delivery to Ctr1. The arguments in favor of Cu(I) include the fact that cellular Cu export and uptake proteins (ATPase7A/B and Ctr1, respectively) specifically transport Cu(I), the abundance of extracellular ascorbate reducing agent in the brain, and evidence of a potential associative (hand-off) mechanism of Cu(I) transfer that may mirror the mechanisms of intracellular Cu chaperone proteins.
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Affiliation(s)
- Ewelina Stefaniak
- Department of Chemistry and Physics, Saint Mary's College, Notre Dame, Indiana 46556, United States.,Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland
| | - M Jake Pushie
- Department of Surgery, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Catherine Vaerewyck
- Department of Chemistry and Physics, Saint Mary's College, Notre Dame, Indiana 46556, United States
| | - David Corcelli
- Department of Chemistry and Physics, Saint Mary's College, Notre Dame, Indiana 46556, United States
| | - Chloe Griggs
- Department of Chemistry and Physics, Saint Mary's College, Notre Dame, Indiana 46556, United States
| | - Whitney Lewis
- Department of Chemistry and Physics, Saint Mary's College, Notre Dame, Indiana 46556, United States
| | - Emma Kelley
- Department of Chemistry and Physics, Saint Mary's College, Notre Dame, Indiana 46556, United States
| | - Noreen Maloney
- Department of Chemistry and Physics, Saint Mary's College, Notre Dame, Indiana 46556, United States
| | - Madison Sendzik
- Department of Chemistry and Physics, Saint Mary's College, Notre Dame, Indiana 46556, United States
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland
| | - Kathryn L Haas
- Department of Chemistry and Physics, Saint Mary's College, Notre Dame, Indiana 46556, United States
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10
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Teng X, Stefaniak E, Girvan P, Kotuniak R, Płonka D, Bal W, Ying L. Hierarchical binding of copperII to N-truncated Aβ4–16 peptide. Metallomics 2020; 12:470-473. [DOI: 10.1039/c9mt00299e] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Multiple intermediates were found in Cu(ii) binding to Aβ4–16 before the formation of a tight complex.
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Affiliation(s)
- Xiangyu Teng
- Department of Chemistry
- Imperial College London
- Molecular Sciences Research Hub
- White City Campus
- London W12 0BZ
| | - Ewelina Stefaniak
- Institute of Biochemistry and Biophysics
- Polish Academy of Sciences
- 02-106 Warsaw
- Poland
| | - Paul Girvan
- Department of Chemistry
- Imperial College London
- Molecular Sciences Research Hub
- White City Campus
- London W12 0BZ
| | - Radosław Kotuniak
- Institute of Biochemistry and Biophysics
- Polish Academy of Sciences
- 02-106 Warsaw
- Poland
| | - Dawid Płonka
- Institute of Biochemistry and Biophysics
- Polish Academy of Sciences
- 02-106 Warsaw
- Poland
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics
- Polish Academy of Sciences
- 02-106 Warsaw
- Poland
| | - Liming Ying
- National Heart and Lung Institute
- Imperial College London
- Molecular Sciences Research Hub
- White City Campus
- London W12 0BZ
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11
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Pushie MJ, Stefaniak E, Sendzik MR, Sokaras D, Kroll T, Haas KL. Using N-Terminal Coordination of Cu(II) and Ni(II) to Isolate the Coordination Environment of Cu(I) and Cu(II) Bound to His13 and His14 in Amyloid-β(4-16). Inorg Chem 2019; 58:15138-15154. [PMID: 31657204 DOI: 10.1021/acs.inorgchem.9b01940] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The amyloid-β (Aβ) peptide is a cleavage product of the amyloid precursor protein and has been implicated as a central player in Alzheimer's disease. The N-terminal end of Aβ is variable, and different proportions of these variable-length Aβ peptides are present in healthy individuals and those with the disease. The N-terminally truncated form of Aβ starting at position 4 (Aβ4-x) has a His residue as the third amino acid (His6 using the formal Aβ numbering). The N-terminal sequence Xaa-Xaa-His is known as an amino terminal copper and nickel binding motif (ATCUN), which avidly binds Cu(II). This motif is not present in the commonly studied Aβ1-x peptides. In addition to the ATCUN site, Aβ4-x contains an additional metal binding site located at the tandem His residues (bis-His at His13 and 14) which is also found in other isoforms of Aβ. Using the ATCUN and bis-His motifs, the Aβ4-x peptide is capable of binding multiple metal ions simultaneously. We confirm that Cu(II) bound to this particular ATCUN site is redox silent, but the second Cu(II) site is redox active and can be readily reduced with ascorbate. We have employed surrogate metal ions to block copper coordination at the ATCUN or the tandem His site in order to isolate spectral features of the copper coordination environment for structural characterization using extended X-ray absorption fine structure (EXAFS) spectroscopy. This approach reveals that each copper coordination environment is independent in the Cu2Aβ4-x state. The identification of two functionally different copper binding environments within the Aβ4-x sequence may have important implications for this peptide in vivo.
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Affiliation(s)
- M Jake Pushie
- Department of Surgery , University of Saskatchewan , Saskatoon , Saskatchewan S7N 5E5 , Canada
| | - Ewelina Stefaniak
- Department of Chemistry and Physics , Saint Mary's College , Notre Dame , Indiana 46556 , United States.,Institute of Biochemistry and Biophysics, Polish Academy of Sciences , Pawińskiego 5a , 02-106 Warsaw , Poland
| | - Madison R Sendzik
- Department of Chemistry and Physics , Saint Mary's College , Notre Dame , Indiana 46556 , United States
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - Thomas Kroll
- Stanford Synchrotron Radiation Lightsource , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - Kathryn L Haas
- Department of Chemistry and Physics , Saint Mary's College , Notre Dame , Indiana 46556 , United States
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12
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Effects of Cu(II) on the aggregation of amyloid-β. J Biol Inorg Chem 2019; 24:1197-1215. [PMID: 31602542 DOI: 10.1007/s00775-019-01727-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/01/2019] [Indexed: 12/27/2022]
Abstract
Aberrant aggregation of the Aβ protein is a hallmark of Alzheimer's disease (AD), but no complete characterization of the molecular level pathogenesis has been achieved. A promising hypothesis is that dysfunction of metal ion homeostasis, and consequently, the undesired interaction of metal ions with Aβ, may be central to the development of AD. Qualitatively, most data indicate that Cu(II) induces rapid self-assembly of both Aβ40 and Aβ42 during the initial phase of the aggregation, while at longer time scales fibrillation may occur, depending on the experimental conditions. For Aβ40 and Cu(II):Aβ ≤ 1, most data imply that low concentration of Aβ40 favors nucleation and rapid fibril elongation, while high concentration of Aβ40 favors formation of amorphous aggregates. However, there are conflicting reports on this issue. For Aβ42 and Cu(II):Aβ ≤ 1, there is consensus that the lag time is extended upon addition of Cu(II). For Cu(II):Aβ > 1, the lag time is increased upon interaction with Cu(II), and in most cases fibrillation is not observed, presumably because Cu(II) occupies a second more solvent-exposed binding site, which is more prone to form metal ion-bridged species and cause rapid formation of non-fibrillar aggregates. The interesting N-terminally truncated Aβ11-40 with high affinity for Cu(II), exhibits delay of fibrillation upon addition of 0.4 eq. Cu(II). In our view, there are still problems achieving reproducible results in this field, and we provide a shortlist of some of the pitfalls. Finally, we propose a consensus model for the effects of Cu(II) on the aggregation kinetics of Aβ.
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13
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Stefaniak E, Bal W. Cu II Binding Properties of N-Truncated Aβ Peptides: In Search of Biological Function. Inorg Chem 2019; 58:13561-13577. [PMID: 31304745 DOI: 10.1021/acs.inorgchem.9b01399] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
As life expectancy increases, the number of people affected by progressive and irreversible dementia, Alzheimer's Disease (AD), is predicted to grow. No drug designs seem to be working in humans, apparently because the origins of AD have not been identified. Invoking amyloid cascade, metal ions, and ROS production hypothesis of AD, herein we share our point of view on Cu(II) binding properties of Aβ4-x, the most prevalent N-truncated Aβ peptide, currently known as the main constituent of amyloid plaques. The capability of Aβ4-x to rapidly take over copper from previously tested Aβ1-x peptides and form highly stable complexes, redox unreactive and resistant to copper exchange reactions, prompted us to propose physiological roles for these peptides. We discuss the new findings on the reactivity of Cu(II)Aβ4-x with coexisting biomolecules in the context of synaptic cleft; we suggest that the role of Aβ4-x peptides is to quench Cu(II) toxicity in the brain and maintain neurotransmission.
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Affiliation(s)
- Ewelina Stefaniak
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences , Pawińskiego 5a , 02-106 Warsaw , Poland
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences , Pawińskiego 5a , 02-106 Warsaw , Poland
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14
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Przygońska K, Pacewicz M, Sadowska W, Poznański J, Bal W, Dadlez M. His6, His13, and His14 residues in Aβ 1-40 peptide significantly and specifically affect oligomeric equilibria. Sci Rep 2019; 9:9449. [PMID: 31263161 PMCID: PMC6602940 DOI: 10.1038/s41598-019-45988-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 06/20/2019] [Indexed: 11/12/2022] Open
Abstract
Oligomers of Aβ peptide are implicated as the most probable causative agent in Alzheimer's disease. However, their structural properties remain elusive due to the dynamic and heterogeneous character of oligomeric species coexisting in solution. Nevertheless, new approaches, mainly based on mass spectrometry, provide unique access to these different structural forms. Using these methods, we previously showed that the N-terminal, non-amyloidogenic region of Aβ is involved in the network of interactions specifically stabilizing oligomers. In the present study, we identified three histidine residues as active participants in this network. Detailed knowledge of the structural features that are potentially important for oligomer-mediated neurotoxicity is a prerequisite for the rational design of oligomerization modifiers.
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Affiliation(s)
- Kaja Przygońska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Magdalena Pacewicz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Wiktoria Sadowska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- Department of Chemistry, University of Warsaw, Warsaw, Poland
| | - Jarosław Poznański
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Michał Dadlez
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
- Institute of Genetics and Biotechnology, Department of Biology, University of Warsaw, Warsaw, Poland.
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15
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Hsu HW, Bondy SC, Kitazawa M. Environmental and Dietary Exposure to Copper and Its Cellular Mechanisms Linking to Alzheimer's Disease. Toxicol Sci 2019; 163:338-345. [PMID: 29409005 DOI: 10.1093/toxsci/kfy025] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Metals are commonly found in the environment, household, and workplaces in various forms, and a significant segment of the population is routinely exposed to the trace amount of metals from variety of sources. Exposure to metals, such as aluminum, lead, iron, and copper, from environment has long been debated as a potential environmental risk factor for Alzheimer's disease (AD) for decades, yet results from in vitro, in vivo, and human population remain controversial. In the case of copper, the neurotoxic mechanism of action was classically viewed as its strong affinity to amyloid-beta (Aβ) to help its aggregation and increase oxidative stress via Fenton reaction. Thus, it has been thought that accumulation of copper mediates neurotoxicity, and removing it from the brain prevents or reverse Aβ plaque burden. Recent evidence, however, suggests dyshomeostasis of copper and its valency in the body, instead of the accumulation and interaction with Aβ, are major determinants of its beneficial effects as an essential metal or its neurotoxic counterpart. This notion is also supported by the fact that genetic loss-of-function mutations on copper transporters lead to severe neurological symptoms. Along with its altered distribution, recent studies have also proposed novel mechanisms of copper neurotoxicity mediated by nonneuronal cell lineages in the brain, such as capillary endothelial cells, leading to development of AD neuropathology. This review covers recent findings of multifactorial toxic mechanisms of copper and discusses the risk of environmental exposure as a potential factor in accounting for the variability of AD incidence.
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Affiliation(s)
- Heng-Wei Hsu
- Department of Medicine, Center for Occupational and Environmental Health, University of California, Irvine, California 92617
| | - Stephen C Bondy
- Department of Medicine, Center for Occupational and Environmental Health, University of California, Irvine, California 92617
| | - Masashi Kitazawa
- Department of Medicine, Center for Occupational and Environmental Health, University of California, Irvine, California 92617
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16
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Mital M, Bal W, Frączyk T, Drew SC. Interplay between Copper, Neprilysin, and N-Truncation of β-Amyloid. Inorg Chem 2018; 57:6193-6197. [PMID: 29774745 DOI: 10.1021/acs.inorgchem.8b00391] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sporadic Alzheimer's disease (AD) is associated with an inefficient clearance of the β-amyloid (Aβ) peptide from the central nervous system. The protein levels and activity of the Zn2+-dependent endopeptidase neprilysin (NEP) inversely correlate with brain Aβ levels during aging and in AD. The present study considered the ability of Cu2+ ions to inhibit human recombinant NEP and the role for NEP in generating N-truncated Aβ fragments with high-affinity Cu2+ binding motifs that can prevent this inhibition. Divalent copper noncompetitively inhibited NEP ( Ki = 1.0 μM), while proteolysis of Aβ yielded the soluble, Aβ4-9 fragment that can bind Cu2+ with femtomolar affinity at pH 7.4. This provides Aβ4-9 with the potential to act as a Cu2+ carrier and to mediate its own production by preventing NEP inhibition. Enzyme inhibition at high Zn2+ concentrations ( Ki = 20 μM) further suggests a mechanism for modulating NEP activity, Aβ4-9 production, and Cu2+ homeostasis.
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Affiliation(s)
- Mariusz Mital
- Florey Department of Neuroscience and Mental Health , The University of Melbourne , Melbourne , Victoria 3010 , Australia.,Institute of Biochemistry and Biophysics , Polish Academy of Sciences , Warsaw , Poland
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics , Polish Academy of Sciences , Warsaw , Poland
| | - Tomasz Frączyk
- Institute of Biochemistry and Biophysics , Polish Academy of Sciences , Warsaw , Poland.,Department of Immunology, Transplantology and Internal Medicine , Medical University of Warsaw , Warsaw , Poland
| | - Simon C Drew
- Department of Medicine (Royal Melbourne Hospital) , The University of Melbourne , Melbourne , Victoria 3010 , Australia
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17
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Kotynia A, Pap JS, Brasun J. The binding abilities of homodetic cyclic His-peptides toward copper ions. Inorganica Chim Acta 2018. [DOI: 10.1016/j.ica.2017.07.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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18
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Conte-Daban A, Boff B, Candido Matias A, Aparicio CNM, Gateau C, Lebrun C, Cerchiaro G, Kieffer I, Sayen S, Guillon E, Delangle P, Hureau C. A Trishistidine Pseudopeptide with Ability to Remove Both Cu Ι and Cu ΙΙ from the Amyloid-β Peptide and to Stop the Associated ROS Formation. Chemistry 2017; 23:17078-17088. [PMID: 28846165 PMCID: PMC5714062 DOI: 10.1002/chem.201703429] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Indexed: 01/08/2023]
Abstract
The pseudopeptide L, derived from a nitrilotriacetic acid scaffold and functionalized with three histidine moieties, is reminiscent of the amino acid side chains encountered in the Alzheimer's peptide (Aβ). Its synthesis and coordination properties for CuΙ and CuΙΙ are described. L efficiently complex CuΙΙ in a square-planar geometry involving three imidazole nitrogen atoms and an amidate-Cu bond. By contrast, CuΙ is coordinated in a tetrahedral environment. The redox behavior is irreversible and follows an ECEC mechanism in accordance with the very different environments of the two redox states of the Cu center. This is in line with the observed resistance of the CuΙ complex to oxidation by oxygen and the CuΙΙ complex reduction by ascorbate. The affinities of L for CuΙΙ and CuΙ at physiological pH are larger than that reported for the Aβ peptide. Therefore, due to its peculiar Cu coordination properties, the ligand L is able to target both redox states of Cu, redox silence them and prevent reactive oxygen species production by the CuAβ complex. Because reactive oxygen species contribute to the oxidative stress, a key issue in Alzheimer's disease, this ligand thus represents a new strategy in the long route of finding molecular concepts for fighting Alzheimer's disease.
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Affiliation(s)
- A. Conte-Daban
- CNRS, LCC (Laboratoire de Chimie de Coordination) 205 route de Narbonne,BP 44099 31077 Toulouse Cedex 4, France
- University of Toulouse, UPS, INPT 31077 Toulouse Cedex 4, France
| | - B. Boff
- Univ. Grenoble Alpes, CEA, CNRS, INAC, SyMMES (UMR 5819), CIBEST, 17 rue des martyrs, F-38 000 Grenoble, France
| | - A. Candido Matias
- Univ. Grenoble Alpes, CEA, CNRS, INAC, SyMMES (UMR 5819), CIBEST, 17 rue des martyrs, F-38 000 Grenoble, France
- Center for Natural Sciences and Humanities, Federal University of ABC – UFABC 09210-580, Santo André, SP, Brazil
| | - C. N. Montes Aparicio
- CNRS, LCC (Laboratoire de Chimie de Coordination) 205 route de Narbonne,BP 44099 31077 Toulouse Cedex 4, France
- University of Toulouse, UPS, INPT 31077 Toulouse Cedex 4, France
| | - C. Gateau
- Univ. Grenoble Alpes, CEA, CNRS, INAC, SyMMES (UMR 5819), CIBEST, 17 rue des martyrs, F-38 000 Grenoble, France
| | - C. Lebrun
- Univ. Grenoble Alpes, CEA, CNRS, INAC, SyMMES (UMR 5819), CIBEST, 17 rue des martyrs, F-38 000 Grenoble, France
| | - G. Cerchiaro
- Center for Natural Sciences and Humanities, Federal University of ABC – UFABC 09210-580, Santo André, SP, Brazil
| | - I. Kieffer
- BM30B/FAME beamline, ESRF, F-38043 Grenoble cedex 9, France
- Observatoire des Sciences de l’Univers de Grenoble, UMS 832 CNRS Université Grenoble Alpes, F-38041 Grenoble, France
| | - S. Sayen
- Institut de Chimie Moléculaire de Reims (ICMR, UMR CNRS 7312), Université de Reims Champagne-Ardenne, F-51687 Reims Cedex 2, France
| | - E. Guillon
- Institut de Chimie Moléculaire de Reims (ICMR, UMR CNRS 7312), Université de Reims Champagne-Ardenne, F-51687 Reims Cedex 2, France
| | - P. Delangle
- Univ. Grenoble Alpes, CEA, CNRS, INAC, SyMMES (UMR 5819), CIBEST, 17 rue des martyrs, F-38 000 Grenoble, France
| | - C. Hureau
- CNRS, LCC (Laboratoire de Chimie de Coordination) 205 route de Narbonne,BP 44099 31077 Toulouse Cedex 4, France
- University of Toulouse, UPS, INPT 31077 Toulouse Cedex 4, France
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19
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Branch T, Barahona M, Dodson CA, Ying L. Kinetic Analysis Reveals the Identity of Aβ-Metal Complex Responsible for the Initial Aggregation of Aβ in the Synapse. ACS Chem Neurosci 2017. [PMID: 28621929 PMCID: PMC5609119 DOI: 10.1021/acschemneuro.7b00121] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
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The
mechanism of Aβ aggregation in the absence of metal ions
is well established, yet the role that Zn2+ and Cu2+, the two most studied metal ions, released during neurotransmission,
paly in promoting Aβ aggregation in the vicinity of neuronal
synapses remains elusive. Here we report the kinetics of Zn2+ binding to Aβ and Zn2+/Cu2+ binding
to Aβ-Cu to form ternary complexes under near physiological
conditions (nM Aβ, μM metal ions). We find that these
reactions are several orders of magnitude slower than Cu2+ binding to Aβ. Coupled reaction-diffusion simulations of the
interactions of synaptically released metal ions with Aβ show
that up to a third of Aβ is Cu2+-bound under repetitive
metal ion release, while any other Aβ-metal complexes (including
Aβ-Zn) are insignificant. We therefore conclude that Zn2+ is unlikely to play an important role in the very early
stages (i.e., dimer formation) of Aβ aggregation, contrary to
a widely held view in the subject. We propose that targeting the specific
interactions between Cu2+ and Aβ may be a viable
option in drug development efforts for early stages of AD.
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Affiliation(s)
- Thomas Branch
- Institute of Chemical Biology, ‡Department of Chemistry, §Department of Mathematics, and ∥National Heart
and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom
| | - Mauricio Barahona
- Institute of Chemical Biology, ‡Department of Chemistry, §Department of Mathematics, and ∥National Heart
and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom
| | - Charlotte A. Dodson
- Institute of Chemical Biology, ‡Department of Chemistry, §Department of Mathematics, and ∥National Heart
and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom
| | - Liming Ying
- Institute of Chemical Biology, ‡Department of Chemistry, §Department of Mathematics, and ∥National Heart
and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom
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20
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Drew SC. The Case for Abandoning Therapeutic Chelation of Copper Ions in Alzheimer's Disease. Front Neurosci 2017; 11:317. [PMID: 28626387 PMCID: PMC5455140 DOI: 10.3389/fnins.2017.00317] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 05/18/2017] [Indexed: 12/26/2022] Open
Abstract
The "therapeutic chelation" approach to treating Alzheimer's disease (AD) evolved from the metals hypothesis, with the premise that small molecules can be designed to prevent transition metal-induced amyloid deposition and oxidative stress within the AD brain. Over more than 20 years, countless in vitro studies have been devoted to characterizing metal binding, its effect on Aβ aggregation, ROS production, and in vitro toxicity. Despite a lack of evidence for any clinical benefit, the conjecture that therapeutic chelation is an effective approach for treating AD remains widespread. Here, the author plays the devil's advocate, questioning the experimental evidence, the dogma, and the value of therapeutic chelation, with a major focus on copper ions.
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Affiliation(s)
- Simon C. Drew
- Department of Medicine, Royal Melbourne Hospital, University of MelbourneMelbourne, VIC, Australia
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