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Rice LJ, Ecroyd H, van Oijen AM. Illuminating amyloid fibrils: Fluorescence-based single-molecule approaches. Comput Struct Biotechnol J 2021; 19:4711-4724. [PMID: 34504664 PMCID: PMC8405898 DOI: 10.1016/j.csbj.2021.08.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 12/15/2022] Open
Abstract
The aggregation of proteins into insoluble filamentous amyloid fibrils is a pathological hallmark of neurodegenerative diseases that include Parkinson's disease and Alzheimer's disease. Since the identification of amyloid fibrils and their association with disease, there has been much work to describe the process by which fibrils form and interact with other proteins. However, due to the dynamic nature of fibril formation and the transient and heterogeneous nature of the intermediates produced, it can be challenging to examine these processes using techniques that rely on traditional ensemble-based measurements. Single-molecule approaches overcome these limitations as rare and short-lived species within a population can be individually studied. Fluorescence-based single-molecule methods have proven to be particularly useful for the study of amyloid fibril formation. In this review, we discuss the use of different experimental single-molecule fluorescence microscopy approaches to study amyloid fibrils and their interaction with other proteins, in particular molecular chaperones. We highlight the mechanistic insights these single-molecule techniques have already provided in our understanding of how fibrils form, and comment on their potential future use in studying amyloid fibrils and their intermediates.
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Affiliation(s)
- Lauren J. Rice
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health & Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Heath Ecroyd
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health & Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Antoine M. van Oijen
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health & Medical Research Institute, Wollongong, NSW 2522, Australia
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52
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Mechanistic roles for altered O-GlcNAcylation in neurodegenerative disorders. Biochem J 2021; 478:2733-2758. [PMID: 34297044 DOI: 10.1042/bcj20200609] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 01/02/2023]
Abstract
Neurodegenerative diseases such as Alzheimer's and Parkinson's remain highly prevalent and incurable disorders. A major challenge in fully understanding and combating the progression of these diseases is the complexity of the network of processes that lead to progressive neuronal dysfunction and death. An ideal therapeutic avenue is conceivably one that could address many if not all of these multiple misregulated mechanisms. Over the years, chemical intervention for the up-regulation of the endogenous posttranslational modification (PTM) O-GlcNAc has been proposed as a potential strategy to slow down the progression of neurodegeneration. Through the development and application of tools that allow dissection of the mechanistic roles of this PTM, there is now a growing body of evidence that O-GlcNAc influences a variety of important neurodegeneration-pertinent mechanisms, with an overall protective effect. As a PTM that is appended onto numerous proteins that participate in protein quality control and homeostasis, metabolism, bioenergetics, neuronal communication, inflammation, and programmed death, O-GlcNAc has demonstrated beneficence in animal models of neurodegenerative diseases, and its up-regulation is now being pursued in multiple clinical studies.
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53
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Viral and Prion Infections Associated with Central Nervous System Syndromes in Brazil. Viruses 2021; 13:v13071370. [PMID: 34372576 PMCID: PMC8310075 DOI: 10.3390/v13071370] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/05/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022] Open
Abstract
Virus-induced infections of the central nervous system (CNS) are among the most serious problems in public health and can be associated with high rates of morbidity and mortality, mainly in low- and middle-income countries, where these manifestations have been neglected. Typically, herpes simplex virus 1 and 2, varicella-zoster, and enterovirus are responsible for a high number of cases in immunocompetent hosts, whereas other herpesviruses (for example, cytomegalovirus) are the most common in immunocompromised individuals. Arboviruses have also been associated with outbreaks with a high burden of neurological disorders, such as the Zika virus epidemic in Brazil. There is a current lack of understanding in Brazil about the most common viruses involved in CNS infections. In this review, we briefly summarize the most recent studies and findings associated with the CNS, in addition to epidemiological data that provide extensive information on the circulation and diversity of the most common neuro-invasive viruses in Brazil. We also highlight important aspects of the prion-associated diseases. This review provides readers with better knowledge of virus-associated CNS infections. A deeper understanding of these infections will support the improvement of the current surveillance strategies to allow the timely monitoring of the emergence/re-emergence of neurotropic viruses.
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54
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Schachner LF, Tran DP, Lee A, McGee JP, Jooss K, Durbin K, Seckler HDS, Adams L, Cline E, Melani R, Ives AN, Des Soye B, Kelleher NL, Patrie SM. Reassembling protein complexes after controlled disassembly by top-down mass spectrometry in native mode. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2021; 465:116591. [PMID: 34539228 PMCID: PMC8445521 DOI: 10.1016/j.ijms.2021.116591] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The combined use of electrospray ionization run in so-called "native mode" with top-down mass spectrometry (nTDMS) is enhancing both structural biology and discovery proteomics by providing three levels of information in a single experiment: the intact mass of a protein or complex, the masses of its subunits and non-covalent cofactors, and fragment ion masses from direct dissociation of subunits that capture the primary sequence and combinations of diverse post-translational modifications (PTMs). While intact mass data are readily deconvoluted using well-known software options, the analysis of fragmentation data that result from a tandem MS experiment - essential for proteoform characterization - is not yet standardized. In this tutorial, we offer a decision-tree for the analysis of nTDMS experiments on protein complexes and diverse bioassemblies. We include an overview of strategies to navigate this type of analysis, provide example data sets, and highlight software for the hypothesis-driven interrogation of fragment ions for localization of PTMs, metals, and cofactors on native proteoforms. Throughout we have emphasized the key features (deconvolution, search mode, validation, other) that the reader can consider when deciding upon their specific experimental and data processing design using both open-access and commercial software.
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Affiliation(s)
- Luis F. Schachner
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Denise P. Tran
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Alexander Lee
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - John P. McGee
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Kevin Jooss
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Kenneth Durbin
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Henrique Dos Santos Seckler
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Lauren Adams
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Erika Cline
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Rafael Melani
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Ashley N. Ives
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Benjamin Des Soye
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Neil L. Kelleher
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Steven M. Patrie
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
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55
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Radbakhsh S, Barreto GE, Bland AR, Sahebkar A. Curcumin: A small molecule with big functionality against amyloid aggregation in neurodegenerative diseases and type 2 diabetes. Biofactors 2021; 47:570-586. [PMID: 33893674 DOI: 10.1002/biof.1735] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 04/12/2021] [Indexed: 12/14/2022]
Abstract
Amyloidosis is a concept that implicates disorders and complications that are due to abnormal protein accumulation in different cells and tissues. Protein aggregation-associated diseases are classified according to the type of aggregates and deposition sites, such as neurodegenerative disorders and type 2 diabetes mellitus. Polyphenolic phytochemicals such as curcumin and its derivatives have anti-amyloid effects both in vitro and in animal models; however, the underlying mechanisms are not understood. In this review, we summarized possible mechanisms by which curcumin could interfere with self-assembly processes and reduce amyloid aggregation in amyloidosis. Furthermore, we discuss clinical trials in which curcumin is used as a therapeutic agent for the treatment of diseases linking to protein aggregates.
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Affiliation(s)
- Shabnam Radbakhsh
- Department of Medical Biotechnology and Nanotechnology, Mashhad University of Medical Sciences, Mashhad, Iran
| | - George E Barreto
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
- Health Research Institute, University of Limerick, Limerick, Ireland
| | - Abigail R Bland
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Department of Chemistry, University of Otago, Dunedin, New Zealand
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
- School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
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56
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Molecular insight into the early stage of amyloid-β(1-42) Homodimers aggregation influenced by histidine tautomerism. Int J Biol Macromol 2021; 184:887-897. [PMID: 34153362 DOI: 10.1016/j.ijbiomac.2021.06.078] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 05/23/2021] [Accepted: 06/10/2021] [Indexed: 11/20/2022]
Abstract
Aggregated amyloid β-peptide (Aβ) in small oligomeric forms inside the brain causes synaptic function disruption and the development of Alzheimer's disease (AD). Histidine is an important amino acid that may lead to structural changes. Aβ42 monomer chain includes 3 histidine residues that considering two ε and δ tautomers 8 isomers, including (εεε) and (εδδ) could be formed. Molecular dynamics simulation on homodimerization of (εεε) (the most common type of tautomers) and (εδδ) tautomers with different initial configurations using monomer chains from our previous work were performed to uncover the tautomeric behavior of histidine on Aβ42 aggregation in a physiological pH which is still largely unknown and impossible to observe experimentally. We found a higher propensity of forming β-sheet in (εδδ) homodimers and specifically in a greater amount from Aβ42 than from Aβ40. A smaller amount of β-sheet formation was observed for (εεε) homodimers compared with (εδδ). Additionally, interactions in (εδδ) homodimers may indicate the importance of the hydrophobic core and C-/N-terminals during oligomerization. Our findings indicate the important role of the tautomeric effect of histidine and (εδδ) homodimers at the early stage of Aβ aggregation.
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57
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Wang Z, Wang Y, Pasangulapati JP, Stover KR, Liu X, Schier SW, Weaver DF. Design, synthesis, and biological evaluation of furosemide analogs as therapeutics for the proteopathy and immunopathy of Alzheimer's disease. Eur J Med Chem 2021; 222:113565. [PMID: 34118718 DOI: 10.1016/j.ejmech.2021.113565] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/18/2021] [Accepted: 05/12/2021] [Indexed: 01/11/2023]
Abstract
β-Amyloid (Aβ) triggered proteopathic and immunopathic processes are a postulated cause of Alzheimer's disease (AD). Monomeric Aβ is derived from amyloid precursor protein, whereupon it aggregates into various assemblies, including oligomers and fibrils, which disrupt neuronal membrane integrity and induce cellular damage. Aβ is directly neurotoxic/synaptotoxic, but may also induce neuroinflammation through the concomitant activation of microglia. Previously, we have shown that furosemide is a known anthranilate-based drug with the capacity to downregulate the proinflammatory microglial M1 phenotype and upregulate the anti-inflammatory M2 phenotype. To further explore the pharmacologic effects of furosemide, this study reports a series of furosemide analogs that target both Aβ aggregation and neuroinflammation, thereby addressing the combined proteopathic-immunopathic pathogenesis of AD. Forty compounds were synthesized and evaluated. Compounds 3c, 3g, and 20 inhibited Aβ oligomerization; 33 and 34 inhibited Aβ fibrillization. 3g and 34 inhibited the production of TNF-α, IL-6, and nitric oxide, downregulated the expression of COX-2 and iNOS, and promoted microglial phagocytotic activity, suggesting dual activity against Aβ aggregation and neuroinflammation. Our data demonstrate the potential therapeutic utility of the furosemide-like anthranilate platform in the development of drug-like molecules targeting both the proteopathy and immunopathy of AD.
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Affiliation(s)
- Zhiyu Wang
- Krembil Research Institute, University Health Network, Toronto, Canada; Faculty of Pharmacy, University of Toronto, Ontario, Canada
| | - Yanfei Wang
- Krembil Research Institute, University Health Network, Toronto, Canada
| | | | - Kurt R Stover
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Xiaojing Liu
- Krembil Research Institute, University Health Network, Toronto, Canada
| | | | - Donald F Weaver
- Krembil Research Institute, University Health Network, Toronto, Canada; Faculty of Pharmacy, University of Toronto, Ontario, Canada; Faculty of Medicine, University of Toronto, Ontario, Canada; Department of Chemistry, University of Toronto, Ontario, Canada.
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58
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Teng JS, Ooi YY, Chye SM, Ling APK, Koh RY. Immunotherapies for Parkinson's disease: Progression of Clinical Development. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2021; 20:802-813. [PMID: 34042040 DOI: 10.2174/1871527320666210526160926] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/28/2021] [Accepted: 03/02/2021] [Indexed: 11/22/2022]
Abstract
Parkinson's disease is a common neurodegenerative disease affecting the movement and wellbeing of most elderlies. The manifestations of Parkinson's disease often include resting tremor, stiffness, bradykinesia and muscular rigidity. The typical hallmark of Parkinson's disease is the destruction of neurons in the substantia nigra and the presence of Lewy bodies in different compartments of the central nervous system. Due to various limitations to the currently available treatments, immunotherapies have emerged to be the new approach to Parkinson's disease treatment. This approach shows some positive outcomes on the efficacy in removing the aggregated species of alpha-synuclein, which is believed to be one of the causes of Parkinson's disease. In this review, an overview of how alpha-synuclein contributes to Parkinson's disease and the effects of a few new immunotherapeutic treatments, including BIIB054 (cinpanemab), MEDI1341, AFFITOPE and PRX002 (prasinezumab) that are currently under clinical development, will be discussed.
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Affiliation(s)
- Jet Shee Teng
- Division of Applied Biomedical Science and Biotechnology, School of Health Science, International Medical University, Kuala Lumpur, Malaysia
| | - Yin Yin Ooi
- School of Biosciences, Faculty of Health & Medical Sciences, Taylor's University, Selangor, Malaysia
| | - Soi Moi Chye
- Division of Applied Biomedical Science and Biotechnology, School of Health Science, International Medical University, Kuala Lumpur, Malaysia
| | - Anna Pick Kiong Ling
- Division of Applied Biomedical Science and Biotechnology, School of Health Science, International Medical University, Kuala Lumpur, Malaysia
| | - Rhun Yian Koh
- Division of Applied Biomedical Science and Biotechnology, School of Health Science, International Medical University, Kuala Lumpur, Malaysia
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59
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Valderhaug VD, Heiney K, Ramstad OH, Bråthen G, Kuan WL, Nichele S, Sandvig A, Sandvig I. Early functional changes associated with alpha-synuclein proteinopathy in engineered human neural networks. Am J Physiol Cell Physiol 2021; 320:C1141-C1152. [PMID: 33950697 DOI: 10.1152/ajpcell.00413.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A patterned spread of proteinopathy represents a common characteristic of many neurodegenerative diseases. In Parkinson's disease (PD), misfolded forms of α-synuclein proteins accumulate in hallmark pathological inclusions termed Lewy bodies and Lewy neurites. Such protein aggregates seem to affect selectively vulnerable neuronal populations in the substantia nigra and to propagate within interconnected neuronal networks. Research findings suggest that these proteinopathic inclusions are present at very early time points in disease development, even before clear behavioral symptoms of dysfunction arise. In this study, we investigate the early pathophysiology developing after induced formation of such PD-related α-synuclein inclusions in a physiologically relevant in vitro setup using engineered human neural networks. We monitor the neural network activity using multielectrode arrays (MEAs) for a period of 3 wk following proteinopathy induction to identify associated changes in network function, with a special emphasis on the measure of network criticality. Self-organized criticality represents the critical point between resilience against perturbation and adaptational flexibility, which appears to be a functional trait in self-organizing neural networks, both in vitro and in vivo. We show that although developing pathology at early onset is not clearly manifest in standard measurements of network function, it may be discerned by investigating differences in network criticality states.
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Affiliation(s)
- Vibeke D Valderhaug
- Department of Neuromedicine and Movement Science, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Kristine Heiney
- Department of Computer Science, Faculty of Technology, Art and Design, Oslo Metropolitan University (OsloMet), Oslo, Norway
| | - Ola Huse Ramstad
- Department of Neuromedicine and Movement Science, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Geir Bråthen
- Department of Neuromedicine and Movement Science, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Wei-Li Kuan
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Stefano Nichele
- Department of Computer Science, Faculty of Technology, Art and Design, Oslo Metropolitan University (OsloMet), Oslo, Norway
| | - Axel Sandvig
- Department of Neuromedicine and Movement Science, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.,Department of Neurology and Clinical Neurophysiology, St Olav's Hospital, Trondheim, Norway.,Department of Clinical Neurosciences, Umeå University Hospital, Umeå, Sweden.,Department of Rehabilitation Medicine, Umeå University Hospital, Umeå, Sweden.,Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden.,Clinical Sciences, Umeå University, Umeå, Sweden
| | - Ioanna Sandvig
- Department of Neuromedicine and Movement Science, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
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60
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McCormick JW, Ammerman L, Chen G, Vogel PD, Wise JG. Transport of Alzheimer's associated amyloid-β catalyzed by P-glycoprotein. PLoS One 2021; 16:e0250371. [PMID: 33901197 PMCID: PMC8075256 DOI: 10.1371/journal.pone.0250371] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/06/2021] [Indexed: 12/24/2022] Open
Abstract
P-glycoprotein (P-gp) is a critical membrane transporter in the blood brain barrier (BBB) and is implicated in Alzheimer’s disease (AD). However, previous studies on the ability of P-gp to directly transport the Alzheimer’s associated amyloid-β (Aβ) protein have produced contradictory results. Here we use molecular dynamics (MD) simulations, transport substrate accumulation studies in cell culture, and biochemical activity assays to show that P-gp actively transports Aβ. We observed transport of Aβ40 and Aβ42 monomers by P-gp in explicit MD simulations of a putative catalytic cycle. In in vitro assays with P-gp overexpressing cells, we observed enhanced accumulation of fluorescently labeled Aβ42 in the presence of Tariquidar, a potent P-gp inhibitor. We also showed that Aβ42 stimulated the ATP hydrolysis activity of isolated P-gp in nanodiscs. Our findings expand the substrate profile of P-gp, and suggest that P-gp may contribute to the onset and progression of AD.
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Affiliation(s)
- James W. McCormick
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas, United States of America
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail: (JGW); (JWM)
| | - Lauren Ammerman
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas, United States of America
- The Center for Drug Discovery, Design and Delivery, Southern Methodist University, Dallas, Texas, United States of America
- The Center for Scientific Computation, Southern Methodist University, Dallas, Texas, United States of America
| | - Gang Chen
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas, United States of America
- The Center for Drug Discovery, Design and Delivery, Southern Methodist University, Dallas, Texas, United States of America
| | - Pia D. Vogel
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas, United States of America
- The Center for Drug Discovery, Design and Delivery, Southern Methodist University, Dallas, Texas, United States of America
| | - John G. Wise
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas, United States of America
- The Center for Drug Discovery, Design and Delivery, Southern Methodist University, Dallas, Texas, United States of America
- The Center for Scientific Computation, Southern Methodist University, Dallas, Texas, United States of America
- * E-mail: (JGW); (JWM)
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61
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Xie W, Kim KH, Vince R, More SS. The Amyloid Aggregation Accelerator Diacetyl Prevents Cognitive Decline in Alzheimer's Mouse Models. Chem Res Toxicol 2021; 34:1355-1366. [PMID: 33857375 DOI: 10.1021/acs.chemrestox.1c00089] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Diacetyl (DA), a food flavorant, is linked with occupational lung disease. Our in vitro experiments described the formation of a covalent adduct by DA with Arg5 of the Aβ1-42 peptide, which resulted in only a transient increase in neurotoxicity in SH-SY5Y cells. However, in vivo implications of these effects on Alzheimer's disease (AD) pathogenesis and the underlying mechanisms remain poorly understood. In the APP/PS1 transgenic AD mouse model, DA treatment did not exacerbate learning and memory deficits in the Morris water maze test. Moreover, DA increased the Aβ1-42 plaque burden and decreased neuronal inflammation in the transgenic AD mice. Additionally, cognitive impairment induced by intracerebroventricular Aβ1-42 was restored by the DA treatment, as assessed by the T-maze test. A corresponding mitigation of neuronal inflammation was also observed in the hippocampus of these nontransgenic mice due to the acceleration of Aβ1-42 aggregation by DA into nontoxic plaques. The data from SDS-PAGE, dot-blot, and TEM in vitro experiments corroborated the acceleration of the Aβ1-42 aggregation observed in vivo in AD animal models and characterized the DA-induced formation of Aβ1-42 fibrils. Such Aβ1-42-DA fibrils were unstable in the presence of detergent and amenable to detection by the thioflavin T reagent, thus underscoring the distinct assembly of these fibrils compared to that of the fibrils of the native Aβ1-42. Taken together, the results of this study present for the first time the in vivo implications of the DA-induced acceleration of Aβ1-42 and may provide a strategy for the rational design of Aβ1-42 aggregation accelerators as AD therapeutics that promote oligomer-free Aβ1-42 fibril formation.
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Affiliation(s)
- Wei Xie
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Kwan Hyun Kim
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Robert Vince
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Swati S More
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
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62
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Araújo AR, Castro VI, Reis RL, Pires RA. Glucosamine and Its Analogues as Modulators of Amyloid-β Toxicity. ACS Med Chem Lett 2021; 12:548-554. [PMID: 33859794 PMCID: PMC8040036 DOI: 10.1021/acsmedchemlett.0c00350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 03/17/2021] [Indexed: 01/04/2023] Open
Abstract
In Alzheimer's disease (AD), amyloid-β (Aβ) oligomers are considered key mediators of synaptic dysfunction and cognitive impairment. These unstable intermediate Aβ species can interfere with different cellular organelles, leading to neuronal cell death, through the formation of Ca2+-permeable membrane pores, impairment in the levels of acetylcholine neurotransmitters, increased insulin resistance, promotion of pro-inflammatory cascades, among others. Based on a series of evidences that indicate the key role of glycosaminoglycans (GAGs) in amyloid plaque formation, we evaluated the capacity of four monosaccharides, i.e., glucosamine (GlcN), N-acetyl glucosamine (GlcNAc), glucosamine-6-sulfate (GlcN6S), and glucosamine-6-phosphate (GlcN6P), to reduce the Aβ-mediated pathological hallmarks. The tested monosaccharides, in particular, GlcN6S and GlcN6P, were able to interact with Aβ aggregates, reducing neuronal cell death, Aβ-mediated damage to the cellular membrane, acetylcholinesterase activity, insulin resistance, and pro-inflammation levels.
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Affiliation(s)
- Ana R. Araújo
- 3B’s
Research Group, I3Bs − Research Institute on Biomaterials,
Biodegradables and Biomimetics, University
of Minho, Headquarters of the European
Institute of Excellence on Tissue Engineering and Regenerative Medicine,
AvePark, Parque de Ciência e Tecnologia, Zona Industrial da
Gandra, 4805-017 Barco, Portugal
- ICVS/3B’s
− PT Government Associate Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - Vânia I.
B. Castro
- 3B’s
Research Group, I3Bs − Research Institute on Biomaterials,
Biodegradables and Biomimetics, University
of Minho, Headquarters of the European
Institute of Excellence on Tissue Engineering and Regenerative Medicine,
AvePark, Parque de Ciência e Tecnologia, Zona Industrial da
Gandra, 4805-017 Barco, Portugal
- ICVS/3B’s
− PT Government Associate Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - Rui L. Reis
- 3B’s
Research Group, I3Bs − Research Institute on Biomaterials,
Biodegradables and Biomimetics, University
of Minho, Headquarters of the European
Institute of Excellence on Tissue Engineering and Regenerative Medicine,
AvePark, Parque de Ciência e Tecnologia, Zona Industrial da
Gandra, 4805-017 Barco, Portugal
- ICVS/3B’s
− PT Government Associate Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - Ricardo A. Pires
- 3B’s
Research Group, I3Bs − Research Institute on Biomaterials,
Biodegradables and Biomimetics, University
of Minho, Headquarters of the European
Institute of Excellence on Tissue Engineering and Regenerative Medicine,
AvePark, Parque de Ciência e Tecnologia, Zona Industrial da
Gandra, 4805-017 Barco, Portugal
- ICVS/3B’s
− PT Government Associate Laboratory, 4806-909 Braga/Guimarães, Portugal
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63
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Hausmann L, Schulz JB. Preface to an editorial controversy on α-synuclein: How good are cellular models?: This is a Preface for an Editorial controversy between Hilal A. Lashuel "Monitoring alpha-synuclein oligomerization and aggregation using bimolecular fluorescence complementation assays: What you see is not always what you get" and Tiago F. Outeiro "Alpha-synuclein oligomerization and aggregation: A model will always be a model" Read Hilal A. Lashuel's reply "Alpha-Synuclein oligomerization and aggregation: All models are useful but only if we know what they model". J Neurochem 2021; 157:869-871. [PMID: 33715161 DOI: 10.1111/jnc.15272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 12/11/2020] [Indexed: 11/30/2022]
Abstract
In many scientific disputes, research evidence may support one side or the other of a working hypothesis, and even in case of largely coherent hypotheses, arguments may be in favor of discrepant points of view. In the case of α-synuclein pathology and specific mechanisms of disease progression, various animal and cellular models have been established to pinpoint the physiological and pathological mechanisms. In the present 'Editorial controversy', two well-reputed researchers, Hilal Lashuel and Tiago F. Outeiro, discuss-with view to findings from their own and others' groups in the context of current status of knowledge-the question of how well models on α-synuclein pathology can reflect actual pathomechanisms, and derive recommendations for future research from it that shall help advance our understanding not only of α-synuclein-related pathologies and its role in the formation of Lewy bodies in particular, but of cellular or animal models in general.
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Affiliation(s)
- Laura Hausmann
- Department of Neurology, RWTH Aachen University, Aachen, Germany
| | - Jörg B Schulz
- Department of Neurology, RWTH Aachen University, Aachen, Germany.,JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Forschungszentrum Jülich GmbH and RWTH Aachen University, Aachen, Germany
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64
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Gomes GN, Levine ZA. Defining the Neuropathological Aggresome across in Silico, in Vitro, and ex Vivo Experiments. J Phys Chem B 2021; 125:1974-1996. [PMID: 33464098 PMCID: PMC8362740 DOI: 10.1021/acs.jpcb.0c09193] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The loss of proteostasis over the life course is associated with a wide range of debilitating degenerative diseases and is a central hallmark of human aging. When left unchecked, proteins that are intrinsically disordered can pathologically aggregate into highly ordered fibrils, plaques, and tangles (termed amyloids), which are associated with countless disorders such as Alzheimer's disease, Parkinson's disease, type II diabetes, cancer, and even certain viral infections. However, despite significant advances in protein folding and solution biophysics techniques, determining the molecular cause of these conditions in humans has remained elusive. This has been due, in part, to recent discoveries showing that soluble protein oligomers, not insoluble fibrils or plaques, drive the majority of pathological processes. This has subsequently led researchers to focus instead on heterogeneous and often promiscuous protein oligomers. Unfortunately, significant gaps remain in how to prepare, model, experimentally corroborate, and extract amyloid oligomers relevant to human disease in a systematic manner. This Review will report on each of these techniques and their successes and shortcomings in an attempt to standardize comparisons between protein oligomers across disciplines, especially in the context of neurodegeneration. By standardizing multiple techniques and identifying their common overlap, a clearer picture of the soluble neuropathological aggresome can be constructed and used as a baseline for studying human disease and aging.
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Affiliation(s)
- Gregory-Neal Gomes
- Department of Pathology, Yale School of Medicine, New Haven, CT, 06520, USA
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Zachary A. Levine
- Department of Pathology, Yale School of Medicine, New Haven, CT, 06520, USA
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06511, USA
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65
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Owens LV, Benedetto A, Dawson N, Gaffney CJ, Parkin ET. Gene therapy-mediated enhancement of protective protein expression for the treatment of Alzheimer's disease. Brain Res 2021; 1753:147264. [PMID: 33422539 DOI: 10.1016/j.brainres.2020.147264] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/22/2020] [Accepted: 12/20/2020] [Indexed: 12/30/2022]
Abstract
Alzheimer's disease (AD) is the leading form of dementia but lacks curative treatments. Current understanding of AD aetiology attributes the development of the disease to the misfolding of two proteins; amyloid-β (Aβ) and hyperphosphorylated tau, with their pathological accumulation leading to concomitant oxidative stress, neuroinflammation, and neuronal death. These processes are regulated at multiple levels to maintain homeostasis and avert disease. However, many of the relevant regulatory proteins appear to be downregulated in the AD-afflicted brain. Enhancement/restoration of these 'protective' proteins, therefore, represents an attractive therapeutic avenue. Gene therapy is a desirable means of achieving this because it is not associated with the side-effects linked to systemic protein administration, and sustained protein expression virtually eliminates compliance issues. The current article represents a focused and succinct review of the better established 'protective' protein targets for gene therapy enhancement/restoration rather than being designed as an exhaustive review incorporating less validated protein subjects. In addition, we will discuss how the risks associated with uncontrolled or irreversible gene expression might be mitigated through combining neuronal-specific promoters, inducible expression systems and localised injections. Whilst many of the gene therapy targets reviewed herein are yet to enter clinical trials, preclinical testing has thus far demonstrated encouraging potential for the gene therapy-based treatment of AD.
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Affiliation(s)
- Lauren V Owens
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Alexandre Benedetto
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Neil Dawson
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Christopher J Gaffney
- Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Edward T Parkin
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK.
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66
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Alarcón-Espósito J, Mallea M, Rodríguez-Lavado J. From Hybrids to New Scaffolds: The Latest Medicinal Chemistry Goals in Multi-target Directed Ligands for Alzheimer's Disease. Curr Neuropharmacol 2021; 19:832-867. [PMID: 32928087 PMCID: PMC8686302 DOI: 10.2174/1570159x18666200914155951] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/13/2020] [Accepted: 08/28/2020] [Indexed: 11/22/2022] Open
Abstract
Alzheimer's disease (AD) is a chronic, progressive, and fatal neurodegenerative disorder affecting cognition, behavior, and function, being one of the most common causes of mental deterioration in elderly people. Once thought as being just developed because of β amyloid depositions or neurofibrillary Tau tangles, during the last decades, numerous AD-related targets have been established, the multifactorial nature of AD became evident. In this context, the one drug-one target paradigm has resulted in being inefficient in facing AD and other disorders with complex etiology, opening the field for the emergence of the multitarget approach. In this review, we highlight the recent advances within this area, emphasizing in hybridization tools of well-known chemical scaffolds endowed with pharmacological properties concerning AD, such as curcumin-, resveratrol-, chromone- and indole-. We focus mainly on well established and incipient AD therapeutic targets, AChE, BuChE, MAOs, β-amyloid deposition, 5-HT4 and Serotonin transporter, with the aim to shed light about new insights in the AD multitarget therapy.
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Affiliation(s)
- Jazmín Alarcón-Espósito
- Departamento de Quimica Organica y Fisicoquimica, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Olivos 1007, Independencia, Santiago, Chile
| | - Michael Mallea
- Departamento de Quimica Organica y Fisicoquimica, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Olivos 1007, Independencia, Santiago, Chile
| | - Julio Rodríguez-Lavado
- Departamento de Quimica Organica y Fisicoquimica, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Olivos 1007, Independencia, Santiago, Chile
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67
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Mladenovic Djordjevic AN, Kapetanou M, Loncarevic-Vasiljkovic N, Todorovic S, Athanasopoulou S, Jovic M, Prvulovic M, Taoufik E, Matsas R, Kanazir S, Gonos ES. Pharmacological intervention in a transgenic mouse model improves Alzheimer's-associated pathological phenotype: Involvement of proteasome activation. Free Radic Biol Med 2021; 162:88-103. [PMID: 33279620 PMCID: PMC7889698 DOI: 10.1016/j.freeradbiomed.2020.11.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/23/2020] [Accepted: 11/28/2020] [Indexed: 12/16/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia worldwide, characterized by a progressive decline in a variety of cognitive and non-cognitive functions. The amyloid beta protein cascade hypothesis places the formation of amyloid beta protein aggregates on the first position in the complex pathological cascade leading to neurodegeneration, and therefore AD might be considered to be a protein-misfolding disease. The Ubiquitin Proteasome System (UPS), being the primary protein degradation mechanism with a fundamental role in the maintenance of proteostasis, has been identified as a putative therapeutic target to delay and/or to decelerate the progression of neurodegenerative disorders that are characterized by accumulated/aggregated proteins. The purpose of this study was to test if the activation of proteasome in vivo can alleviate AD pathology. Specifically by using two compounds with complementary modes of proteasome activation and documented antioxidant and redox regulating properties in the 5xFAD transgenic mice model of AD, we ameliorated a number of AD related deficits. Shortly after proteasome activation we detected significantly reduced amyloid-beta load correlated with improved motor functions, reduced anxiety and frailty level. Essentially, to our knowledge this is the first report to demonstrate a dual activation of the proteasome and its downstream effects. In conclusion, these findings open up new directions for future therapeutic potential of proteasome-mediated proteolysis enhancement.
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Affiliation(s)
- Aleksandra N Mladenovic Djordjevic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Boulevard Despota Stefana, 142, 11000, Belgrade, Serbia.
| | - Marianna Kapetanou
- Institute of Chemical Biology, National Hellenic Research Foundation, 48 Vassileos Constantinou Ave., 11635, Athens, Greece
| | - Natasa Loncarevic-Vasiljkovic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Boulevard Despota Stefana, 142, 11000, Belgrade, Serbia; Molecular Nutrition and Health Lab, CEDOC - Centro de Estudos de Doenças Crónicas, NOVA Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Edifício CEDOC II, Rua Câmara Pestana 6, 1150-082, Lisboa, Portugal
| | - Smilja Todorovic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Boulevard Despota Stefana, 142, 11000, Belgrade, Serbia
| | - Sofia Athanasopoulou
- Institute of Chemical Biology, National Hellenic Research Foundation, 48 Vassileos Constantinou Ave., 11635, Athens, Greece; Department of Biology, Faculty of Medicine, University of Thessaly, Biopolis, 41500, Larissa, Greece
| | - Milena Jovic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Boulevard Despota Stefana, 142, 11000, Belgrade, Serbia
| | - Milica Prvulovic
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Boulevard Despota Stefana, 142, 11000, Belgrade, Serbia
| | - Era Taoufik
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Department of Neurobiology, Hellenic Pasteur Institute, 127 Vasilissis Sofias Avenue, 11521, Athens, Greece
| | - Rebecca Matsas
- Laboratory of Cellular and Molecular Neurobiology-Stem Cells, Department of Neurobiology, Hellenic Pasteur Institute, 127 Vasilissis Sofias Avenue, 11521, Athens, Greece
| | - Selma Kanazir
- Department for Neurobiology, Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Boulevard Despota Stefana, 142, 11000, Belgrade, Serbia
| | - Efstathios S Gonos
- Institute of Chemical Biology, National Hellenic Research Foundation, 48 Vassileos Constantinou Ave., 11635, Athens, Greece.
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68
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Parodi-Rullán R, Sone JY, Fossati S. Endothelial Mitochondrial Dysfunction in Cerebral Amyloid Angiopathy and Alzheimer's Disease. J Alzheimers Dis 2020; 72:1019-1039. [PMID: 31306129 DOI: 10.3233/jad-190357] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia. Cerebrovascular dysfunction is one of the earliest events in the pathogenesis of AD, as well as in vascular and mixed dementias. Cerebral amyloid angiopathy (CAA), the deposition of amyloid around cerebral vessels, is observed in up to 90% of AD patients and in approximately 50% of elderly individuals over 80 years of age. CAA is a strong contributor to vascular dysfunction in AD. CAA-laden brain vessels are characterized by dysfunctional hemodynamics and leaky blood-brain barrier (BBB), contributing to clearance failure and further accumulation of amyloid-β (Aβ) in the cerebrovasculature and brain parenchyma. Mitochondrial dysfunction is increasingly recognized as an important early initiator of the pathogenesis of AD and CAA. The objective of this review is to discuss the effects of Aβ on cerebral microvascular cell function, focusing on its impact on endothelial mitochondria. After introducing CAA and its etiology and genetic risk factors, we describe the pathological relationship between cerebrovascular amyloidosis and brain microvascular endothelial cell dysfunction, critically analyzing its roles in disease progression, hypoperfusion, and BBB integrity. Then, we focus on discussing the effect of Aβ challenge on endothelial mitochondrial dysfunction pathways, and their contribution to the progression of neurovascular dysfunction in AD and dementia. Finally, we report potential pharmacological and non-pharmacological mitochondria-targeted therapeutic strategies which may help prevent or delay cerebrovascular failure.
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Affiliation(s)
- Rebecca Parodi-Rullán
- Alzheimer's Center at Temple, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Je Yeong Sone
- Department of Psychiatry, Center for Brain Health, NYU School of Medicine, New York, NY, USA
| | - Silvia Fossati
- Alzheimer's Center at Temple, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
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69
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Ulamec SM, Brockwell DJ, Radford SE. Looking Beyond the Core: The Role of Flanking Regions in the Aggregation of Amyloidogenic Peptides and Proteins. Front Neurosci 2020; 14:611285. [PMID: 33335475 PMCID: PMC7736610 DOI: 10.3389/fnins.2020.611285] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/02/2020] [Indexed: 12/14/2022] Open
Abstract
Amyloid proteins are involved in many neurodegenerative disorders such as Alzheimer’s disease [Tau, Amyloid β (Aβ)], Parkinson’s disease [alpha-synuclein (αSyn)], and amyotrophic lateral sclerosis (TDP-43). Driven by the early observation of the presence of ordered structure within amyloid fibrils and the potential to develop inhibitors of their formation, a major goal of the amyloid field has been to elucidate the structure of the amyloid fold at atomic resolution. This has now been achieved for a wide variety of sequences using solid-state NMR, microcrystallography, X-ray fiber diffraction and cryo-electron microscopy. These studies, together with in silico methods able to predict aggregation-prone regions (APRs) in protein sequences, have provided a wealth of information about the ordered fibril cores that comprise the amyloid fold. Structural and kinetic analyses have also shown that amyloidogenic proteins often contain less well-ordered sequences outside of the amyloid core (termed here as flanking regions) that modulate function, toxicity and/or aggregation rates. These flanking regions, which often form a dynamically disordered “fuzzy coat” around the fibril core, have been shown to play key parts in the physiological roles of functional amyloids, including the binding of RNA and in phase separation. They are also the mediators of chaperone binding and membrane binding/disruption in toxic amyloid assemblies. Here, we review the role of flanking regions in different proteins spanning both functional amyloid and amyloid in disease, in the context of their role in aggregation, toxicity and cellular (dys)function. Understanding the properties of these regions could provide new opportunities to target disease-related aggregation without disturbing critical biological functions.
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Affiliation(s)
- Sabine M Ulamec
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - David J Brockwell
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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70
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Tandem-Homodimer of a β-Sheet-Forming Short Peptide Inhibits Random-to-β Structural Transition of Its Original Monomer. Processes (Basel) 2020. [DOI: 10.3390/pr8111421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
There is an increasing interest in designing fibrillogenesis modulators for treating amyloid β (Aβ)-peptide-associated diseases. The use of Aβ fragment peptides and their derivatives, as well as nonpeptidyl natural products, is one promising approach to prevent Aβ fibrillation. In this study, we demonstrate that tandem-homodimers (TDs) of a β-sheet-forming short peptide in which the amino acid sequence is duplicated in series and joined via an amino alkanoic acid linker of different chain lengths, preventing the random-to-β structural transition of the original monomer. Ape5-TD, containing 5-amino pentanoate, most potently prevented this transition for at least five days by generating disordered aggregates with reduced tryptic stability. The linkers in the TDs generated this inhibitory activity, probably due to their bent conformations and hydrophobicity, appropriate for accommodating and twisting the monomers, resulting in irregular arrangements of the peptides. The present study could allow the design of a new class of protein/peptide fibrillogenesis modulators.
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71
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Fulopova B, Stuart KE, Bennett W, Bindoff A, King AE, Vickers JC, Canty AJ. Regional differences in beta amyloid plaque deposition and variable response to midlife environmental enrichment in the cortex of APP/PS1 mice. J Comp Neurol 2020; 529:1849-1862. [PMID: 33104234 DOI: 10.1002/cne.25060] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 01/21/2023]
Abstract
Environmentally enriched housing conditions can increase performance on cognitive tasks in APP/PS1 mice; however, the potential effects of environmental enrichment (EE) on disease modification in terms of pathological change are inconclusive. We hypothesized that previous contrasting findings may be attributable to regional differences in susceptibility to amyloid beta (Aβ) plaque deposition in cortical regions that are functionally associated with EE. We characterized fibrillar plaque deposition in 6, 12, and 18-22 months old APP/PS1 mice in the prefrontal (PFC), somatosensory (SS2), and primary motor cortex (M1). We found a significant increase in plaque load between 6 and 12 months in all regions. In animals over 12 months, only the PFC region continued to significantly accumulate plaques. Additionally, 12 months old animals subjected to 6 months of EE showed improved spatial navigation and had significantly fewer plaques in M1 and SS2, but not in the PFC. These findings suggest that the PFC region is selectively susceptible to Aβ deposition and less responsive to the attenuating effects of EE. In contrast, M1 and SS2 regions plateau with respect to Aβ deposition by 12 months of age and are susceptible to amyloid pathology modification by midlife EE.
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Affiliation(s)
- Barbora Fulopova
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Tasmania, Australia
| | - Kimberley E Stuart
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Tasmania, Australia
| | - William Bennett
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Tasmania, Australia
| | - Aidan Bindoff
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Tasmania, Australia
| | - Anna E King
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Tasmania, Australia
| | - James C Vickers
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Tasmania, Australia
| | - Alison J Canty
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Tasmania, Australia
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72
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Camarillo-López RH, Hernández Rodríguez M, Torres-Ramos MA, Arciniega-Martínez IM, García-Marín ID, Correa Basurto J, Méndez Méndez JV, Rosales-Hernández MC. Tert-butyl-(4-hydroxy-3-((3-(2-methylpiperidin-yl)propyl)carbamoyl)phenyl)carbamate Has Moderated Protective Activity in Astrocytes Stimulated with Amyloid Beta 1-42 and in a Scopolamine Model. Molecules 2020; 25:molecules25215009. [PMID: 33137907 PMCID: PMC7672627 DOI: 10.3390/molecules25215009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease with no cure nowadays; there is no treatment either to prevent or to stop its progression. In vitro studies suggested that tert-butyl-(4-hydroxy-3-((3-(2-methylpiperidin-yl)propyl)carbamoyl)phenyl) carbamate named the M4 compound can act as both β-secretase and an acetylcholinesterase inhibitor, preventing the amyloid beta peptide (Aβ) aggregation and the formation of fibrils (fAβ) from Aβ1-42. This work first aimed to assess in in vitro studies to see whether the death of astrocyte cells promoted by Aβ1-42 could be prevented. Second, our work investigated the ability of the M4 compound to inhibit amyloidogenesis using an in vivo model after scopolamine administration. The results showed that M4 possesses a moderate protective effect in astrocytes against Aβ1-42 due to a reduction in the TNF-α and free radicals observed in cell cultures. In the in vivo studies, however, no significant effect of M4 was observed in comparison with a galantamine model employed in rats, in which case this outcome was attributed to the bioavailability of M4 in the brain of the rats.
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Affiliation(s)
- Raúl Horacio Camarillo-López
- Laboratorio de Biofísica y biocatálisis, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Diaz Mirón s/n, 11340 Ciudad de México, Mexico; (R.H.C.-L.); (M.H.R.); (I.D.G.-M.)
| | - Maricarmen Hernández Rodríguez
- Laboratorio de Biofísica y biocatálisis, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Diaz Mirón s/n, 11340 Ciudad de México, Mexico; (R.H.C.-L.); (M.H.R.); (I.D.G.-M.)
| | - Mónica Adriana Torres-Ramos
- Unidad Periférica de Neurociencias, Facultad de Medicina UNAM-Instituto Nacional de Neurología y Neurocirugía, MVS-SSA, Insurgentes sur 3877, La Fama, Tlalpan, 14269 Ciudad de México, Mexico;
| | - Ivonne Maciel Arciniega-Martínez
- Laboratorio de Inmunidad de Mucosas, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón s/n, 11340 Ciudad de México, Mexico;
| | - Iohanan Daniel García-Marín
- Laboratorio de Biofísica y biocatálisis, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Diaz Mirón s/n, 11340 Ciudad de México, Mexico; (R.H.C.-L.); (M.H.R.); (I.D.G.-M.)
| | - José Correa Basurto
- Laboratorio de Diseño y Desarrollo de Nuevos Fármacos e Innovación Biotecnológica, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, 11340 Ciudad de México, Mexico;
| | - Juan Vicente Méndez Méndez
- Centro de Nanociencias y Micro y Nanotecnologías, Instituto Politécnico Nacional. Av. Luis Enrique Erro s/n, Nueva Industrial Vallejo, Gustavo A. Madero, 07738 Ciudad de México, Mexico;
| | - Martha Cecilia Rosales-Hernández
- Laboratorio de Biofísica y biocatálisis, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Diaz Mirón s/n, 11340 Ciudad de México, Mexico; (R.H.C.-L.); (M.H.R.); (I.D.G.-M.)
- Correspondence:
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73
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Oxidative Stress in Alzheimer's Disease: In Vitro Therapeutic Effect of Amniotic Fluid Stem Cells Extracellular Vesicles. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:2785343. [PMID: 33193997 PMCID: PMC7641262 DOI: 10.1155/2020/2785343] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/20/2020] [Accepted: 07/31/2020] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is characterized by abnormal protein aggregation, deposition of extracellular β-amyloid proteins (Aβ), besides an increase of oxidative stress. Amniotic fluid stem cells (AFSCs) should have a therapeutic potential for neurodegenerative disorders, mainly through a paracrine effect mediated by extracellular vesicles (EV). Here, we examined the effect of EV derived from human AFSCs (AFSC-EV) on the disease phenotypes in an AD neuron primary culture. We observed a positive effect of AFSC-EV on neuron morphology, viability, and Aβ and phospho-Tau levels. This could be due to the apoptotic and autophagic pathway modulation derived from the decrease in oxidative stress. Indeed, reactive oxygen species (ROS) were reduced, while GSH levels were enhanced. This modulation could be ascribed to the presence of ROS regulating enzymes, such as SOD1 present into the AFSC-EV themselves. This study describes the ROS-modulating effects of extracellular vesicles alone, apart from their deriving stem cell, in an AD in vitro model, proposing AFSC-EV as a therapeutic tool to stop the progression of AD.
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74
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Vadukul DM, Maina M, Franklin H, Nardecchia A, Serpell LC, Marshall KE. Internalisation and toxicity of amyloid-β 1-42 are influenced by its conformation and assembly state rather than size. FEBS Lett 2020; 594:3490-3503. [PMID: 32871611 DOI: 10.1002/1873-3468.13919] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/30/2020] [Accepted: 08/19/2020] [Indexed: 01/18/2023]
Abstract
Amyloid fibrils found in plaques in Alzheimer's disease (AD) brains are composed of amyloid-β peptides. Oligomeric amyloid-β 1-42 (Aβ42) is thought to play a critical role in neurodegeneration in AD. Here, we determine how size and conformation affect neurotoxicity and internalisation of Aβ42 assemblies using biophysical methods, immunoblotting, toxicity assays and live-cell imaging. We report significant cytotoxicity of Aβ42 oligomers and their internalisation into neurons. In contrast, Aβ42 fibrils show reduced internalisation and no toxicity. Sonicating Aβ42 fibrils generates species similar in size to oligomers but remains nontoxic. The results suggest that Aβ42 oligomers have unique properties that underlie their neurotoxic potential. Furthermore, we show that incubating cells with Aβ42 oligomers for 24 h is sufficient to trigger irreversible neurotoxicity.
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Affiliation(s)
- Devkee M Vadukul
- Dementia Research group, Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, E Sussex, UK.,CEMO-Alzheimer Dementia group, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Mahmoud Maina
- Dementia Research group, Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, E Sussex, UK.,College of Medical Sciences, Yobe State University, Nigeria
| | - Hannah Franklin
- Dementia Research group, Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, E Sussex, UK
| | - Astrid Nardecchia
- Dementia Research group, Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, E Sussex, UK
| | - Louise C Serpell
- Dementia Research group, Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, E Sussex, UK
| | - Karen E Marshall
- Dementia Research group, Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, E Sussex, UK
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75
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Rudajev V, Novotny J. The Role of Lipid Environment in Ganglioside GM1-Induced Amyloid β Aggregation. MEMBRANES 2020; 10:membranes10090226. [PMID: 32916822 PMCID: PMC7558528 DOI: 10.3390/membranes10090226] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/04/2020] [Accepted: 09/07/2020] [Indexed: 01/14/2023]
Abstract
Ganglioside GM1 is the most common brain ganglioside enriched in plasma membrane regions known as lipid rafts or membrane microdomains. GM1 participates in many modulatory and communication functions associated with the development, differentiation, and protection of neuronal tissue. It has, however, been demonstrated that GM1 plays a negative role in the pathophysiology of Alzheimer's disease (AD). The two features of AD are the formation of intracellular neurofibrillary bodies and the accumulation of extracellular amyloid β (Aβ). Aβ is a peptide characterized by intrinsic conformational flexibility. Depending on its partners, Aβ can adopt different spatial arrangements. GM1 has been shown to induce specific changes in the spatial organization of Aβ, which lead to enhanced peptide accumulation and deleterious effect especially on neuronal membranes containing clusters of this ganglioside. Changes in GM1 levels and distribution during the development of AD may contribute to the aggravation of the disease.
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76
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Paul A, Frenkel-Pinter M, Escobar Alvarez D, Milordini G, Gazit E, Zacco E, Segal D. Tryptophan-galactosylamine conjugates inhibit and disaggregate amyloid fibrils of Aβ42 and hIAPP peptides while reducing their toxicity. Commun Biol 2020; 3:484. [PMID: 32879439 PMCID: PMC7468108 DOI: 10.1038/s42003-020-01216-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 07/31/2020] [Indexed: 12/14/2022] Open
Abstract
Self-assembly of proteins into amyloid fibrils is a hallmark of various diseases, including Alzheimer's disease (AD) and Type-2 diabetes Mellitus (T2DM). Aggregation of specific peptides, like Aβ42 in AD and hIAPP in T2DM, causes cellular dysfunction resulting in the respective pathology. While these amyloidogenic proteins lack sequence homology, they all contain aromatic amino acids in their hydrophobic core that play a major role in their self-assembly. Targeting these aromatic residues by small molecules may be an attractive approach for inhibiting amyloid aggregation. Here, various biochemical and biophysical techniques revealed that a panel of tryptophan-galactosylamine conjugates significantly inhibit fibril formation of Aβ42 and hIAPP, and disassemble their pre-formed fibrils in a dose-dependent manner. They are also not toxic to mammalian cells and can reduce the cytotoxicity induced by Aβ42 and hIAPP aggregates. These tryptophan-galactosylamine conjugates can therefore serve as a scaffold for the development of therapeutics towards AD and T2DM.
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Affiliation(s)
- Ashim Paul
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
| | - Moran Frenkel-Pinter
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
| | - Daniela Escobar Alvarez
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
| | - Giulia Milordini
- The Maurice Wohl Clinical Neuroscience Institute, King's College London, Brixton, London, SE5 9RT, UK
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
| | - Elsa Zacco
- The Maurice Wohl Clinical Neuroscience Institute, King's College London, Brixton, London, SE5 9RT, UK.
- RNA Central Lab, Center for Human Technologies, Istituto Italiano di Tecnologia, 16152, Genova, Italy.
| | - Daniel Segal
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel.
- Sagol Interdisciplinary School of Neuroscience, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel.
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77
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Mittal V, Devitt G, Nedeljkovic M, Carpenter LG, Chong HMH, Wilkinson JS, Mahajan S, Mashanovich GZ. Ge on Si waveguide mid-infrared absorption spectroscopy of proteins and their aggregates. BIOMEDICAL OPTICS EXPRESS 2020; 11:4714-4722. [PMID: 32923073 PMCID: PMC7449756 DOI: 10.1364/boe.398013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/19/2020] [Accepted: 07/21/2020] [Indexed: 06/11/2023]
Abstract
Specific proteins and their aggregates form toxic amyloid plaques and neurofibrillary tangles in the brains of people suffering from neurodegenerative diseases such as Alzheimer's and Parkinson's. It is important to study these conformational changes to identify and differentiate these diseases at an early stage so that timely medication is provided to patients. Mid-infrared spectroscopy can be used to monitor these changes by studying the line-shapes and the relative absorbances of amide bands present in proteins. This work focusses on the spectroscopy of the protein, Bovine Serum Albumin as an exemplar, and its aggregates using germanium on silicon waveguides in the 1900-1000 cm-1 (5.3-10.0 µm) spectral region.
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Affiliation(s)
- Vinita Mittal
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - George Devitt
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Milos Nedeljkovic
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Lewis G. Carpenter
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Harold M. H. Chong
- School of Electronics and Computer Science, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - James S. Wilkinson
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Sumeet Mahajan
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
- School of Chemistry, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Goran Z. Mashanovich
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, United Kingdom
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78
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Collagen hydrogel confinement of Amyloid-β (Aβ) accelerates aggregation and reduces cytotoxic effects. Acta Biomater 2020; 112:164-173. [PMID: 32464268 DOI: 10.1016/j.actbio.2020.05.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia and is associated with the accumulation of amyloid-β (Aβ), a peptide whose aggregation has been associated with neurotoxicity. Drugs targeting Aβ have shown great promise in 2D in vitro models and mouse models, yet preclinical and clinical trials for AD have been highly disappointing. We propose that current in vitro culture systems for discovering and developing AD drugs have significant limitations; specifically, that Aβ aggregation is vastly different in these 2D cultures carried out on flat plastic or glass substrates vs. in a 3D environment, such as brain tissue, where Aβ confinement alters aggregation kinetics and thermodynamics. In this work, we identified attenuation of Aβ cytotoxicity in 3D hydrogel culture compared to 2D cell culture. We investigated Aβ structure and aggregation in solution vs. hydrogel using Transmission Electron Microscopy (TEM), Fluorescence Correlation Spectroscopy (FCS), and Thioflavin T (ThT) assays. Our results reveal that the equilibrium is shifted to stable extended β-sheet (ThT positive) aggregates in hydrogels and away from the relatively unstable/unstructured presumed toxic oligomeric Aβ species in solution. Volume exclusion imparted by hydrogel confinement stabilizes unfolded, presumably toxic species, promoting stable extended β-sheet fibrils. STATEMENT OF SIGNIFICANCE: Alzheimer's disease (AD) is a devastating disease and has been studied for over 100 years. Yet, no cure exists and only 5 prescription drugs are FDA-approved to temporarily treat the AD symptoms of declining brain functions related to thinking and memory. Why don't we have more effective treatments to cure AD or relieve AD symptoms? We propose that current culture methods based upon cells cultured on flat, stiff substrates have significant limitations for discovering and developing AD drugs. This study provides strong evidence that AD drugs should be tested in 3D culture systems as a step along the development pathway towards new, more effective drugs to treat AD.
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79
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Altered brain arginine metabolism with age in the APP swe/PSEN1 dE9 mouse model of Alzheimer's disease. Neurochem Int 2020; 140:104798. [PMID: 32711019 DOI: 10.1016/j.neuint.2020.104798] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 06/09/2020] [Accepted: 06/26/2020] [Indexed: 12/19/2022]
Abstract
Amyloid-beta (Aβ) cleaved from amyloid precursor protein (APP) has been proposed to play a central and causative role in the aetiology of Alzheimer's disease (AD). APPswe/PSEN1dE9 (APP/PS1) transgenic mice display chronic Aβ accumulation and deposition in the brain. L-arginine is a semi-essential amino acid with a number of bioactive metabolites, and altered arginine metabolism has been implicated in the pathogenesis and/or the development of AD. This study systematically investigated how arginine metabolic profiles changed in the frontal cortex, hippocampus, parahippocampal region and cerebellum of male APP/PS1 mice at 4, 9 and 17 months of age relative to their sex- and age-matched wildtype controls. Immunohistochemistry demonstrated age-related Aβ deposition in the brain. High-performance liquid chromatography and mass spectrometry revealed age-related increases in glutamine, spermidine and spermine in APP/PS1 mice in a region-specific manner. Notably, genotype-related increases in spermine were found in the frontal cortex at the 9-month age point and in the frontal cortex, hippocampus and parahippocampal region at 17 months of age. Given the existing literature indicating the role of polyamines (spermine in particular) in modulating the aggregation and toxicity of Aβ oligomers, increased spermidine and spermine levels in APP/PS1 mice may be a neuroprotective mechanism to combat Aβ toxicity. Future research is required to better understand the functional significance of these changes.
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80
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Biophysical characterization of p53 core domain aggregates. Biochem J 2020; 477:111-120. [PMID: 31841126 DOI: 10.1042/bcj20190778] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/12/2019] [Accepted: 12/13/2019] [Indexed: 12/16/2022]
Abstract
Aggregation is the cause of numerous protein conformation diseases. A common facet of these maladies is the transition of a protein from its functional native state into higher order forms, such as oligomers and amyloid fibrils. p53 is an essential tumor suppressor that is prone to such conformational transitions, resulting in its compromised ability to avert cancer. This work explores the biophysical properties of early-, mid-, and late-stage p53 core domain (p53C) aggregates. Atomistic and coarse-grained molecular dynamics (MD) simulations suggest that early- and mid-stage p53C aggregates have a polymorphic topology of antiparallel and parallel β-sheets that localize to the core amyloidogenic sequence. Both topologies involve similar extents of interstrand mainchain hydrogen bonding, while sidechain interactions could play a role in regulating strand orientation. The free energy difference between the antiparallel and parallel states was within statistical uncertainty. Negative stain electron microscopy of mature fibrils shows a wide distribution of fiber widths, indicating that polymorphism may extend to the quaternary structure level. Circular dichroism of the fibrils was indicative of β-sheet rich structures in atypical conformations. The Raman spectrum of aggregated p53C was consistent with a mixture of arranged β-sheets and heterogeneous structural elements, which is compatible with the MD findings of an ordered β-sheet nucleus flanked by disordered structure. Structural polymorphism is a common property of amyloids; however, because certain polymorphs of the same protein can be more harmful than others, going forward it will be pertinent to establish correlations between p53C aggregate structure and pathology.
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81
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Fayazi R, Habibi-Rezaei M, Heiat M, Javadi-Zarnaghi F, Taheri RA. Glycated albumin precipitation using aptamer conjugated magnetic nanoparticles. Sci Rep 2020; 10:10716. [PMID: 32612182 PMCID: PMC7329883 DOI: 10.1038/s41598-020-67469-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 06/02/2020] [Indexed: 01/10/2023] Open
Abstract
To develop a strategy for the elimination of prefibrillar amyloid aggregates, a three-step non-modified DNA aptamer conjugation on silica-coated magnetic nanoparticles was carried out to achieve aptamer conjugated on MNP (Ap-SiMNP). Prefibrillar amyloid aggregates are generated under a diabetic condition which are prominently participated in developing diabetic complications. The binding properties of candidate DNA aptamer against serum albumin prefibrillar amyloid aggregates (AA20) were verified using electrophoretic mobility shift assay (EMSA) and surface plasmon resonance spectroscopy (SPR) analysis. The chloro-functionalized silica-coated MNPs were synthesized then a nano-targeting structure as aptamer conjugated on MNP (Ap-SiMNP) was constructed. Finally, Ap-SiMNP was verified for specific binding efficiency and AA20 removal using an external magnetic field. The candidate aptamer showed a high binding capacity at EMSA and SPR analysis (KD = 3.4 × 10─9 M) and successfully used to construct Ap-SiMNP. Here, we show a proof of concept for an efficient bio-scavenger as Ap-SiMNP to provide a promising opportunity to consider as a possible strategy to overcome some diabetic complications through specific binding/removal of toxic AA20 species.
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Affiliation(s)
- R Fayazi
- School of Biology, University of Tehran, P.O.Box 14155-6455, Tehran, Iran
| | - M Habibi-Rezaei
- School of Biology, University of Tehran, P.O.Box 14155-6455, Tehran, Iran.
- Center of Excellence in Nano-Biomedicine, University of Tehran, Tehran, Iran.
| | - M Heiat
- Research Center for Gastroenterology and Liver Disease, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - F Javadi-Zarnaghi
- Department of Cell and Molecular Biology and Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran
| | - R A Taheri
- Nanobiotechnolology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
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82
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Kaur A, Kaur A, Goyal D, Goyal B. How Does the Mono-Triazole Derivative Modulate Aβ 42 Aggregation and Disrupt a Protofibril Structure: Insights from Molecular Dynamics Simulations. ACS OMEGA 2020; 5:15606-15619. [PMID: 32637837 PMCID: PMC7331201 DOI: 10.1021/acsomega.0c01825] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/08/2020] [Indexed: 05/31/2023]
Abstract
Clinical studies have identified that abnormal self-assembly of amyloid-β (Aβ) peptide into toxic fibrillar aggregates is associated with the pathology of Alzheimer's disease (AD). The most acceptable therapeutic approach to stop the progression of AD is to inhibit the formation of β-sheet-rich structures. Recently, we designed and evaluated a series of novel mono-triazole derivatives 4(a-x), where compound 4v was identified as the most potent inhibitor of Aβ42 aggregation and disaggregates preformed Aβ42 fibrils significantly. Moreover, 4v strongly averts the Cu2+-induced Aβ42 aggregation and disaggregates the preformed Cu2+-induced Aβ42 fibrils, halts the generation of reactive oxygen species, and shows neuroprotective effects in SH-SY5Y cells. However, the underlying molecular mechanism of inhibition of Aβ42 aggregation by 4v and disaggregation of preformed Aβ42 fibrils remains obscure. In this work, molecular dynamics (MD) simulations have been performed to explore the conformational ensemble of the Aβ42 monomer and a pentameric protofibril structure of Aβ42 in the presence of 4v. The MD simulations highlighted that 4v binds preferentially at the central hydrophobic core region of the Aβ42 monomer and chains D and E of the Aβ42 protofibril. The dictionary of secondary structure of proteins analysis indicated that 4v retards the conformational conversion of the helix-rich structure of the Aβ42 monomer into the aggregation-prone β-sheet conformation. The binding free energy calculated by the molecular mechanics Poisson-Boltzmann surface area method revealed an energetically favorable process with ΔG binding = -44.9 ± 3.3 kcal/mol for the Aβ42 monomer-4v complex. The free energy landscape analysis highlighted that the Aβ42 monomer-4v complex sampled conformations with significantly higher helical contents (35 and 49%) as compared to the Aβ42 monomer alone (17%). Compound 4v displayed hydrogen bonding with Gly37 (chain E) and π-π interactions with Phe19 (chain D) of the Aβ42 protofibril. Further, the per-residue binding free energy analysis also highlighted that Phe19 (chain D) and Gly37 (chain E) of the Aβ42 protofibril showed the maximum contribution in the binding free energy. The decreased binding affinity and residue-residue contacts between chains D and E of the Aβ42 protofibril in the presence of 4v indicate destabilization of the Aβ42 protofibril structure. Overall, the structural information obtained through MD simulations indicated that 4v stabilizes the native helical conformation of the Aβ42 monomer and persuades a destabilization in the protofibril structure of Aβ42. The results of the study will be useful in the rational design of potent inhibitors against amyloid aggregation.
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Affiliation(s)
- Amandeep Kaur
- Department
of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Anupamjeet Kaur
- Department
of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Deepti Goyal
- Department
of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Bhupesh Goyal
- School
of Chemistry & Biochemistry, Thapar
Institute of Engineering & Technology, Patiala 147004, Punjab, India
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83
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Watanabe-Nakayama T, Sahoo BR, Ramamoorthy A, Ono K. High-Speed Atomic Force Microscopy Reveals the Structural Dynamics of the Amyloid-β and Amylin Aggregation Pathways. Int J Mol Sci 2020; 21:E4287. [PMID: 32560229 PMCID: PMC7352471 DOI: 10.3390/ijms21124287] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/09/2020] [Accepted: 06/14/2020] [Indexed: 12/18/2022] Open
Abstract
Individual Alzheimer's disease (AD) patients have been shown to have structurally distinct amyloid-β (Aβ) aggregates, including fibrils, in their brain. These findings suggest the possibility of a relationship between AD progression and Aβ fibril structures. Thus, the characterization of the structural dynamics of Aβ could aid the development of novel therapeutic strategies and diagnosis. Protein structure and dynamics have typically been studied separately. Most of the commonly used biophysical approaches are limited in providing substantial details regarding the combination of both structure and dynamics. On the other hand, high-speed atomic force microscopy (HS-AFM), which simultaneously visualizes an individual protein structure and its dynamics in liquid in real time, can uniquely link the structure and the kinetic details, and it can also unveil novel insights. Although amyloidogenic proteins generate heterogeneously aggregated species, including transient unstable states during the aggregation process, HS-AFM elucidated the structural dynamics of individual aggregates in real time in liquid without purification and isolation. Here, we review and discuss the HS-AFM imaging of amyloid aggregation and strategies to optimize the experiments showing findings from Aβ and amylin, which is associated with type II diabetes, shares some common biological features with Aβ, and is reported to be involved in AD.
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Affiliation(s)
| | - Bikash R. Sahoo
- Biophysics Program, Department of Chemistry, Macromolecular Science and Engineering, and Biomedical Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA;
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA;
| | - Kenjiro Ono
- Division of Neurology, Department of Internal Medicine, School of Medicine, Showa University, Hatanodai, Shinagawa district, Tokyo 142-8666, Japan;
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84
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Tahirbegi B, Magness AJ, Piersimoni ME, Knöpfel T, Willison KR, Klug DR, Ying L. A Novel Aβ 40 Assembly at Physiological Concentration. Sci Rep 2020; 10:9477. [PMID: 32528074 PMCID: PMC7289798 DOI: 10.1038/s41598-020-66373-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/15/2020] [Indexed: 01/27/2023] Open
Abstract
Aggregates of amyloid-β (Aβ) are characteristic of Alzheimer's disease, but there is no consensus as to either the nature of the toxic molecular complex or the mechanism by which toxic aggregates are produced. We report on a novel feature of amyloid-lipid interactions where discontinuities in the lipid continuum can serve as catalytic centers for a previously unseen microscale aggregation phenomenon. We show that specific lipid membrane conditions rapidly produce long contours of lipid-bound peptide, even at sub-physiological concentrations of Aβ. Using single molecule fluorescence, time-lapse TIRF microscopy and AFM imaging we characterize this phenomenon and identify some exceptional properties of the aggregation pathway which make it a likely contributor to early oligomer and fibril formation, and thus a potential critical mechanism in the etiology of AD. We infer that these amyloidogenic events occur only at areas of high membrane curvature, which suggests a range of possible mechanisms by which accumulated physiological changes may lead to their inception. The speed of the formation is in hours to days, even at 1 nM peptide concentrations. Lipid features of this type may act like an assembly line for monomeric and small oligomeric subunits of Aβ to increase their aggregation states. We conclude that under lipid environmental conditions, where catalytic centers of the observed type are common, key pathological features of AD may arise on a very short timescale under physiological concentration.
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Affiliation(s)
- Bogachan Tahirbegi
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Alastair J Magness
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | | | - Thomas Knöpfel
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Keith R Willison
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - David R Klug
- Department of Chemistry, Imperial College London, London, United Kingdom.
| | - Liming Ying
- National Heart and Lung Institute, Imperial College London, London, United Kingdom.
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85
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Liang J, Pitsillou E, Man AYL, Madzima S, Bresnehan SM, Nakai ME, Hung A, Karagiannis TC. Utilisation of the OliveNet™ Library to investigate phenolic compounds using molecular modelling studies in the context of Alzheimer's disease. Comput Biol Chem 2020; 87:107271. [PMID: 32521495 DOI: 10.1016/j.compbiolchem.2020.107271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 04/24/2020] [Accepted: 04/26/2020] [Indexed: 01/05/2023]
Abstract
Alzheimer's disease (AD) is a debilitating neurodegenerative disease that affects over 47 million people worldwide, and is the most common form of dementia. There is a vast body of literature demonstrating that the disease is caused by an accumulation of toxic extracellular amyloid-β (Aβ) peptides and intracellular neurofibrillary tangles that consist of hyperphosphorylated tau. Adherence to the Mediterranean diet has been shown to reduce the incidence of AD and the phenolic compounds in extra virgin olive oil, including oleocanthal, have gained a significant amount of attention. A large number of these ligands have been described in the pre-existing literature and 222 of these compounds have been characterised in the OliveNet™ database. In this study, molecular docking was used to screen the 222 phenolic compounds from the OliveNet™ database and assess their ability to bind to various forms of the Aβ and tau proteins. The phenolic ligands were found to be binding strongly to the hairpin-turn of the Aβ1-40 and Aβ1-42 monomers, and binding sites were also identified in the tau fibril protein structures. Luteolin-4'-O-rutinoside, oleuricine A, isorhoifolin, luteolin-7-O-rutinoside, cyanidin-3-O-rutinoside and luteolin-7,4-O-diglucoside were predicted to be novel lead compounds. Molecular dynamics (MD) simulations performed using well-known olive ligands bound to Aβ1-42 oligomers highlighted that future work may examine potential anti-aggregating properties of novel compounds in the OliveNet™ database. This may lead to the development and evaluation of new compounds that may have efficacy against Alzheimer's disease.
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Affiliation(s)
- Julia Liang
- Epigenomic Medicine, Department of Diabetes, Central Clinical School, Monash University, Prahran, VIC 3004, Australia; School of Science, RMIT University, VIC 3001, Australia
| | - Eleni Pitsillou
- Epigenomic Medicine, Department of Diabetes, Central Clinical School, Monash University, Prahran, VIC 3004, Australia; Department of Microbiology and Immunology (Pathology), The University of Melbourne, Parkville, VIC 3052, Australia
| | - Abella Y L Man
- Epigenomic Medicine, Department of Diabetes, Central Clinical School, Monash University, Prahran, VIC 3004, Australia; Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Sibonginkosi Madzima
- Epigenomic Medicine, Department of Diabetes, Central Clinical School, Monash University, Prahran, VIC 3004, Australia; Department of Microbiology and Immunology (Pathology), The University of Melbourne, Parkville, VIC 3052, Australia
| | - Sarah M Bresnehan
- Epigenomic Medicine, Department of Diabetes, Central Clinical School, Monash University, Prahran, VIC 3004, Australia; Department of Microbiology and Immunology (Pathology), The University of Melbourne, Parkville, VIC 3052, Australia
| | - Michael E Nakai
- Epigenomic Medicine, Department of Diabetes, Central Clinical School, Monash University, Prahran, VIC 3004, Australia; Department of Microbiology and Immunology (Pathology), The University of Melbourne, Parkville, VIC 3052, Australia
| | - Andrew Hung
- School of Science, RMIT University, VIC 3001, Australia
| | - Tom C Karagiannis
- Epigenomic Medicine, Department of Diabetes, Central Clinical School, Monash University, Prahran, VIC 3004, Australia; Department of Clinical Pathology, The University of Melbourne, Parkville, VIC 3052, Australia.
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86
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Ashrafizadeh M, Zarrabi A, Najafi M, Samarghandian S, Mohammadinejad R, Ahn KS. Resveratrol targeting tau proteins, amyloid-beta aggregations, and their adverse effects: An updated review. Phytother Res 2020; 34:2867-2888. [PMID: 32491273 DOI: 10.1002/ptr.6732] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/18/2020] [Accepted: 05/04/2020] [Indexed: 12/12/2022]
Abstract
Resveratrol (Res) is a non-flavonoid compound with pharmacological actions such as antioxidant, antiinflammatory, hepatoprotective, antidiabetes, and antitumor. This plant-derived chemical has a long history usage in treatment of diseases. The excellent therapeutic impacts of Res and its capability in penetration into blood-brain barrier have made it an appropriate candidate in the treatment of neurological disorders (NDs). Tau protein aggregations and amyloid-beta (Aβ) deposits are responsible for the induction of NDs. A variety of studies have elucidated the role of these aggregations in NDs and the underlying molecular pathways in their development. In the present review, based on the recently published articles, we describe that how Res administration could inhibit amyloidogenic pathway and stimulate processes such as autophagy to degrade Aβ aggregations. Besides, we demonstrate that Res supplementation is beneficial in dephosphorylation of tau proteins and suppressing their aggregations. Then, we discuss molecular pathways and relate them to the treatment of NDs.
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Affiliation(s)
- Milad Ashrafizadeh
- Department of Basic Science, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
| | - Ali Zarrabi
- Sabanci University Nanotechnology Research and Application Center (SUNUM), Tuzla, Turkey
| | - Masoud Najafi
- Radiology and Nuclear Medicine Department, School of Paramedical Sciences, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Saeed Samarghandian
- Department of Basic Medical Sciences, Neyshabur University of Medical Sciences, Neyshabur, Iran
| | - Reza Mohammadinejad
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Kwang Seok Ahn
- College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
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87
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Khorvash M, Blinov N, Ladner-Keay C, Lu J, Silverman JM, Gibbs E, Wang YT, Kovalenko A, Wishart D, Cashman NR. Molecular interactions between monoclonal oligomer-specific antibody 5E3 and its amyloid beta cognates. PLoS One 2020; 15:e0232266. [PMID: 32469918 PMCID: PMC7259632 DOI: 10.1371/journal.pone.0232266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 04/12/2020] [Indexed: 11/30/2022] Open
Abstract
Oligomeric amyloid β (Aβ) is currently considered the most neurotoxic form of the Aβ peptide implicated in Alzheimer’s disease (AD). The molecular structures of the oligomers have remained mostly unknown due to their transient nature. As a result, the molecular mechanisms of interactions between conformation-specific antibodies and their Aβ oligomer (AβO) cognates are not well understood. A monoclonal conformation-specific antibody, m5E3, was raised against a structural epitope of Aβ oligomers. m5E3 binds to AβOs with high affinity, but not to Aβ monomers or fibrils. In this study, a computational model of the variable fragment (Fv) of the m5E3 antibody (Fv5E3) is introduced. We further employ docking and molecular dynamics simulations to determine the molecular details of the antibody-oligomer interactions, and to classify the AβOs as Fv5E3-positives and negatives, and to provide a rationale for the low affinity of Fv5E3 for fibrils. This information will help us to perform site-directed mutagenesis on the m5E3 antibody to improve its specificity and affinity toward oligomeric Aβ species. We also provide evidence for the possible capability of the m5E3 antibody to disaggregate AβOs and to fragment protofilaments.
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Affiliation(s)
- Massih Khorvash
- Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Nick Blinov
- Department of Mechanical Engineering, Edmonton, Alberta, Canada
- National Research Council of Canada, Edmonton, Alberta, Canada
| | - Carol Ladner-Keay
- National Research Council of Canada, Edmonton, Alberta, Canada
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Jie Lu
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Judith M. Silverman
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Ebrima Gibbs
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Yu Tian Wang
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Andriy Kovalenko
- Department of Mechanical Engineering, Edmonton, Alberta, Canada
- National Research Council of Canada, Edmonton, Alberta, Canada
| | - David Wishart
- National Research Council of Canada, Edmonton, Alberta, Canada
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
- Department of Computing Science, University of Alberta, Edmonton, Alberta, Canada
| | - Neil R. Cashman
- Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
- * E-mail:
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88
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Do Post-Translational Modifications Influence Protein Aggregation in Neurodegenerative Diseases: A Systematic Review. Brain Sci 2020; 10:brainsci10040232. [PMID: 32290481 PMCID: PMC7226274 DOI: 10.3390/brainsci10040232] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 12/14/2022] Open
Abstract
The accumulation of abnormal protein aggregates represents a universal hallmark of neurodegenerative diseases (NDDs). Post-translational modifications (PTMs) regulate protein structure and function. Dysregulated PTMs may influence the propensity for protein aggregation in NDD-proteinopathies. To investigate this, we systematically reviewed the literature to evaluate effects of PTMs on aggregation propensity for major proteins linked to the pathogenesis and/or progression of NDDs. A search of PubMed, MEDLINE, EMBASE, and Web of Science Core Collection was conducted to retrieve studies that investigated an association between PTMs and protein aggregation in seven NDDs: Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), spinocerebellar ataxias, transmissible spongiform encephalopathy, and multiple sclerosis. Together, 1222 studies were identified, of which 69 met eligibility criteria. We identified that the following PTMs, in isolation or combination, potentially act as modulators of proteinopathy in NDDs: isoaspartate formation in Aβ, phosphorylation of Aβ or tau in AD; acetylation, 4-hydroxy-2-neonal modification, O-GlcNAcylation or phosphorylation of α-synuclein in PD; acetylation or phosphorylation of TAR DNA-binding protein-43 in ALS, and SUMOylation of superoxide dismutase-1 in ALS; and phosphorylation of huntingtin in HD. The potential pharmacological manipulation of these aggregation-modulating PTMs represents an as-yet untapped source of therapy to treat NDDs.
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89
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Fakhranurova L, Balobanov V, Ryabova N, Glukhov A, Ilyina N, Markelova N, Marchenkov V, Katina N. The presence of cross-β-structure as a key determinant of carbonic anhydrase amyloid fibrils cytotoxicity. Biochem Biophys Res Commun 2020; 524:453-458. [PMID: 32007272 DOI: 10.1016/j.bbrc.2020.01.113] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 01/20/2020] [Indexed: 12/19/2022]
Abstract
In most cases high cytotoxicity is characteristic of aggregates formed during lag phase of amyloid formation, whereas mature fibrils represent the depot of protein molecules incapable of damaging cell membranes. However, new experimental data show that in cases of some proteins the fibrils are the most toxic type of aggregates. Meanwhile, structural characteristics of cytotoxic fibrils and mechanisms of their cell damaging action are insufficiently explored. This work is dedicated to studying amyloid aggregation of bovine carbonic anhydrase (BCA) and effect of aggregates formed at different stages of amyloid formation on viability of the cells. Here we demonstrate that oligomers formed during lag phase do not decrease cell viability, whereas protofibrils and amyloids of BCA are cytotoxic. Obtained results allow concluding that toxicity of BCA aggregates is associated with the presence of amyloid cross-β-structure, which signature is absorbance peak at low wavenumbers at FTIR spectra (1615-1630 cm-1). Our data suppose that cross-β-core of ВСА amyloid fibrils is responsible for their cytotoxicity.
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Affiliation(s)
- Liliia Fakhranurova
- Institute of Theoretical and Experimental Biophysics RAS, Institutskaya st., 3, Russia.
| | - Vitaly Balobanov
- Institute of Protein Research RAS, Institutskaya st., 4, Russia.
| | - Natalya Ryabova
- Institute of Protein Research RAS, Institutskaya st., 4, Russia.
| | - Anatoly Glukhov
- Institute of Protein Research RAS, Institutskaya st., 4, Russia.
| | - Nelly Ilyina
- Institute of Protein Research RAS, Institutskaya st., 4, Russia.
| | | | | | - Natalya Katina
- Institute of Protein Research RAS, Institutskaya st., 4, Russia.
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90
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Ziaunys M, Sneideris T, Smirnovas V. Formation of distinct prion protein amyloid fibrils under identical experimental conditions. Sci Rep 2020; 10:4572. [PMID: 32165692 PMCID: PMC7067779 DOI: 10.1038/s41598-020-61663-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 02/28/2020] [Indexed: 01/01/2023] Open
Abstract
Protein aggregation into amyloid fibrils is linked to multiple neurodegenerative disorders, such as Alzheimer’s, Parkinson’s or Creutzfeldt-Jakob disease. A better understanding of the way these aggregates form is vital for the development of drugs. A large detriment to amyloid research is the ability of amyloidogenic proteins to spontaneously aggregate into multiple structurally distinct fibrils (strains) with different stability and seeding properties. In this work we show that prion proteins are capable of forming more than one type of fibril under the exact same conditions by assessing their Thioflavin T (ThT) binding ability, morphology, secondary structure, stability and seeding potential.
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Affiliation(s)
- Mantas Ziaunys
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Tomas Sneideris
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Vytautas Smirnovas
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania.
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91
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L. Almeida Z, M. M. Brito R. Structure and Aggregation Mechanisms in Amyloids. Molecules 2020; 25:molecules25051195. [PMID: 32155822 PMCID: PMC7179426 DOI: 10.3390/molecules25051195] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/17/2020] [Accepted: 02/19/2020] [Indexed: 12/27/2022] Open
Abstract
The aggregation of a polypeptide chain into amyloid fibrils and their accumulation and deposition into insoluble plaques and intracellular inclusions is the hallmark of several misfolding diseases known as amyloidoses. Alzheimer′s, Parkinson′s and Huntington’s diseases are some of the approximately 50 amyloid diseases described to date. The identification and characterization of the molecular species critical for amyloid formation and disease development have been the focus of intense scrutiny. Methods such as X-ray and electron diffraction, solid-state nuclear magnetic resonance spectroscopy (ssNMR) and cryo-electron microscopy (cryo-EM) have been extensively used and they have contributed to shed a new light onto the structure of amyloid, revealing a multiplicity of polymorphic structures that generally fit the cross-β amyloid motif. The development of rational therapeutic approaches against these debilitating and increasingly frequent misfolding diseases requires a thorough understanding of the molecular mechanisms underlying the amyloid cascade. Here, we review the current knowledge on amyloid fibril formation for several proteins and peptides from a kinetic and thermodynamic point of view, the structure of the molecular species involved in the amyloidogenic process, and the origin of their cytotoxicity.
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92
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Andreone BJ, Larhammar M, Lewcock JW. Cell Death and Neurodegeneration. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a036434. [PMID: 31451511 DOI: 10.1101/cshperspect.a036434] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Neurodegenerative disease is characterized by the progressive deterioration of neuronal function caused by the degeneration of synapses, axons, and ultimately the death of nerve cells. An increased understanding of the mechanisms underlying altered cellular homeostasis and neurodegeneration is critical to the development of effective treatments for disease. Here, we review what is known about neuronal cell death and how it relates to our understanding of neurodegenerative disease pathology. First, we discuss prominent molecular signaling pathways that drive neuronal loss, and highlight the upstream cell biology underlying their activation. We then address how neuronal death may occur during disease in response to neuron intrinsic and extrinsic stressors. An improved understanding of the molecular mechanisms underlying neuronal dysfunction and cell death will open up avenues for clinical intervention in a field lacking disease-modifying treatments.
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93
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Prolonged isolation stress accelerates the onset of Alzheimer’s disease-related pathology in 5xFAD mice despite running wheels and environmental enrichment. Behav Brain Res 2020; 379:112366. [DOI: 10.1016/j.bbr.2019.112366] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 11/14/2019] [Accepted: 11/14/2019] [Indexed: 02/06/2023]
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94
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Liu L, Wu Q, Zhong W, Chen Y, Zhang W, Ren H, Sun L, Sun J. Microarray Analysis of Differential Gene Expression in Alzheimer's Disease Identifies Potential Biomarkers with Diagnostic Value. Med Sci Monit 2020; 26:e919249. [PMID: 31984950 PMCID: PMC7001516 DOI: 10.12659/msm.919249] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 11/04/2019] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Alzheimer disease (AD) is a common and fatal subtype of dementia that remains a challenge to diagnose and treat. This study aimed to identify potential biomarkers that influence the prognosis of AD. MATERIAL AND METHODS A total of 6 gene expression profiles from the Gene Expression Omnibus (GEO) database were assessed for their potential as AD biomarkers. We identified differentially expressed genes (DEGs) using the prediction analysis for microarray (PAM) algorithm and obtained hub genes through the analysis of the protein-protein interaction (PPI) network and module analysis. RESULTS We identified 6 gene expression profiles from the GEO database and assessed their potential as AD biomarkers. Shared gene sets were extracted and integrated into large expression profile matrices. We identified 2514 DEGs including 68 upregulated- and 2446 downregulated genes through analysis of the limma package. We screened 379 significant DEGs including 68 upregulated and 307 downregulated genes for their ability to distinguish AD from control samples using PAM algorithm. Functional enrichment of the 379 target genes was produced from Database for Annotation, Visualization and Integrated Discovery.(DAVID) and included histone function, beta receptor signaling, cell growth, and angiogenesis. The downregulated genes were significantly enriched in MAPK signaling, synaptic signaling, neuronal apoptosis and AD associated pathways. Upon analysis of the PPI network, 32 hub genes including ENO2, CCT2, CALM2, ACACB, ATP5B, MDH1, and PP2CA were screened. Of these hub genes, NFKBIA and ACACB were upregulated and 29 genes were downregulated in AD patients. CONCLUSIONS We screened 379 significant DEGs as potential biomarkers of AD using PAM and obtained 32 hub genes through PPI network and module analysis. These findings reveal new potential AD biomarkers with prognostic and therapeutic value.
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Affiliation(s)
- Liping Liu
- Pharmaceutical College, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu, P.R. China
| | - Qin Wu
- Medical Technology College, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu, P.R. China
| | - Weiwei Zhong
- School of Public Foundation, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu, P.R. China
| | - Yuping Chen
- School of Basic Medicine, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu, P.R. China
| | - Wenying Zhang
- Institute of Biotechnology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu, P.R. China
| | - Huiling Ren
- Pharmaceutical College, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu, P.R. China
| | - Ling Sun
- Pharmaceutical College, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu, P.R. China
| | - Jihu Sun
- Department of Science and Technology, Jiangsu Vocational College of Medicine, Yancheng, Jiangsu, P.R. China
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95
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Liyanage SI, Weaver DF. Misfolded proteins as a therapeutic target in Alzheimer's disease. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2020; 118:371-411. [PMID: 31928732 DOI: 10.1016/bs.apcsb.2019.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
For decades, Alzheimer's Disease (AD) was defined as a disorder of protein misfolding and aggregation. In particular, the extracellular peptide fragment: amyloid-β (Aβ), and the intracellular microtubule-associated protein: tau, were thought to initiate a neurodegenerative cascade which culminated in AD's progressive loss of memory and executive function. As such, both proteins became the focus of intense scrutiny, and served as the principal pathogenic target for hundreds of clinical trials. However, with varying efficacy, none of these investigations produced a disease-modifying therapy - offering patients with AD little recourse aside from transient, symptomatic medications. The near universal failure of clinical trials is unprecedented for a major research discipline. In part, this has motivated an increasing skepticism of the relevance of protein misfolding to AD's etiology. Several recent observations, principally the presence of significant protein pathologies in non-demented seniors, have lent credence to an apparent cursory role for Aβ and tau. Herein, we review both Aβ and tau, examining the processes from their biosynthesis to their pathogenesis and evaluate their vulnerability to medicinal intervention. We further attempt to reconcile the apparent failure of trials with the potential these targets hold. Ultimately, we seek to answer if protein misfolding is a viable platform in the pursuit of a disease-arresting strategy for AD.
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Affiliation(s)
- S Imindu Liyanage
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Donald F Weaver
- Krembil Research Institute, University Health Network, Toronto, ON, Canada; Departments of Medicine (Neurology), Chemistry and Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
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96
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Vacchini M, Edwards R, Guizzardi R, Palmioli A, Ciaramelli C, Paiotta A, Airoldi C, La Ferla B, Cipolla L. Glycan Carriers As Glycotools for Medicinal Chemistry Applications. Curr Med Chem 2019; 26:6349-6398. [DOI: 10.2174/0929867326666190104164653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 11/07/2018] [Accepted: 12/18/2018] [Indexed: 12/12/2022]
Abstract
Carbohydrates are one of the most powerful and versatile classes of biomolecules that nature
uses to regulate organisms’ biochemistry, modulating plenty of signaling events within cells, triggering
a plethora of physiological and pathological cellular behaviors. In this framework, glycan carrier
systems or carbohydrate-decorated materials constitute interesting and relevant tools for medicinal
chemistry applications. In the last few decades, efforts have been focused, among others, on the development
of multivalent glycoconjugates, biosensors, glycoarrays, carbohydrate-decorated biomaterials
for regenerative medicine, and glyconanoparticles. This review aims to provide the reader with a general
overview of the different carbohydrate carrier systems that have been developed as tools in different
medicinal chemistry approaches relying on carbohydrate-protein interactions. Given the extent of
this topic, the present review will focus on selected examples that highlight the advancements and potentialities
offered by this specific area of research, rather than being an exhaustive literature survey of
any specific glyco-functionalized system.
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Affiliation(s)
- Mattia Vacchini
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Rana Edwards
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Roberto Guizzardi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Alessandro Palmioli
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Carlotta Ciaramelli
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Alice Paiotta
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Cristina Airoldi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Barbara La Ferla
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Laura Cipolla
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
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97
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Chai AB, Leung GKF, Callaghan R, Gelissen IC. P‐glycoprotein: a role in the export of amyloid‐β in Alzheimer's disease? FEBS J 2019; 287:612-625. [DOI: 10.1111/febs.15148] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 10/09/2019] [Accepted: 11/19/2019] [Indexed: 12/25/2022]
Affiliation(s)
- Amanda B. Chai
- School of Pharmacy Faculty of Medicine and Health University of Sydney Australia
| | - Gavin K. F. Leung
- School of Pharmacy Faculty of Medicine and Health University of Sydney Australia
| | - Richard Callaghan
- Research School of Biology and Medical School Australian National University Canberra Australia
| | - Ingrid C. Gelissen
- School of Pharmacy Faculty of Medicine and Health University of Sydney Australia
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98
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β-Amyloid Peptide: the Cell Compartment Multi-faceted Interaction in Alzheimer's Disease. Neurotox Res 2019; 37:250-263. [PMID: 31811589 DOI: 10.1007/s12640-019-00116-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/29/2019] [Accepted: 09/16/2019] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD) is the most widespread form of dementia, characterized by memory loss and reduction of cognitive functions that strongly interfere with normal daily life. Numerous evidences show that aggregates of the amyloid beta peptide, formed by 39 to 42 amino acid residues (Aβ39-43), from soluble small oligomers to large fibrils are characteristic markers of this pathology. However, AD is a complex disease and its neurodegenerative molecular mechanism is not yet fully understood. Growing evidence suggests a link between Aβ polymorphic nature, oligomers and fibrils, and specific mechanisms of neurodegeneration. The Aβ variable nature and its multiplicity of interactions with different proteins and organelles reflect the complexity of this pathology. In this review, we analyze the effects of the interaction between Aβ peptide and different cellular compartments in relation to the different kinds and sizes of amyloid aggregates. In particular, Aβ interaction with different cell structures such as the plasma membrane, mitochondria, lysosomes, nucleus, and endoplasmic reticulum is discussed. Further, we analyze the Aβ peptide ability to modify the structure and function of the target organelle, inducing alteration of its physiological role thus contributing to the pathological event. Dysfunction of cellular components terminating with the activation of the cellular death mechanism and subsequent neurodegeneration is also taken into consideration.
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99
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Palazzi L, Leri M, Cesaro S, Stefani M, Bucciantini M, Polverino de Laureto P. Insight into the molecular mechanism underlying the inhibition of α-synuclein aggregation by hydroxytyrosol. Biochem Pharmacol 2019; 173:113722. [PMID: 31756328 DOI: 10.1016/j.bcp.2019.113722] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 11/15/2019] [Indexed: 01/07/2023]
Abstract
Parkinson's disease (PD) is the second most prevalent neurodegenerative disease in the elderly people. To date, drugs able to reverse the disease are not available; the gold standard is levodopa that only relieves clinical symptoms, yet with severe side effects after prolonged administration. Many efforts are underway to find alternative targets for PD prevention or treatment, the most promising being α-synuclein (Syn). Recently, we reported that oleuropein aglycone (OleA) interferes with amyloid aggregation of Syn both stabilizing its monomeric state and inducing the formation of harmless, off-pathway oligomers. This study is focused at describing the interaction between Syn and hydroxytyrosol (HT), the phenolic moiety and main metabolite of OleA, and the interferences with Syn aggregation by using biophysical and biological techniques. Our results show that HT dose-dependently inhibits Syn aggregation and that covalent and non-covalent binding mediate HT-Syn interaction. HT does not modify the natively unfolded structure of Syn, rather, it stabilizes specific regions of the molecule leading to inhibition of protein fibrillation. Cellular assays showed that HT reduces the toxicity of Syn aggregates. Moreover, Syn aggregates interaction with the cell membrane, an important factor for prion-like properties of Syn on-pathway oligomers, was reduced in cells exposed to Syn aggregates grown in the presence of HT.
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Affiliation(s)
- Luana Palazzi
- Department of Pharmaceutical Sciences, CRIBI Biotechnology Centre, University of Padova, Italy
| | - Manuela Leri
- Department of Biomedical, Experimental and Clinical Sciences, University of Firenze, Italy; Department of Neuroscience, Psychology, Drug Research and Child Health, University of Firenze, Italy
| | - Samuele Cesaro
- Department of Pharmaceutical Sciences, CRIBI Biotechnology Centre, University of Padova, Italy
| | - Massimo Stefani
- Department of Biomedical, Experimental and Clinical Sciences, University of Firenze, Italy
| | - Monica Bucciantini
- Department of Biomedical, Experimental and Clinical Sciences, University of Firenze, Italy
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100
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Sameni S, Zhang R, Digman MA. Number and molecular brightness analysis reveals Htt25Q protein aggregation upon the uptake of Htt97Q aggregates. Biochem Biophys Res Commun 2019; 522:133-137. [PMID: 31757420 DOI: 10.1016/j.bbrc.2019.10.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 10/03/2019] [Indexed: 10/25/2022]
Abstract
Number and molecular Brightness (N&B) analysis is a powerful method used to monitor protein aggregation in living cells. Here, we used the N&B method to characterize the unexpanded HTT protein oligomerization after the internalization of the mutant HTT (mHTT) which contains a CAG repeat extensions encoding for long polyglutamine (polyQ) proteins resulting in misfolding and aggregation. HEK cells expressing Htt25Q-mCherry proteins were infected with Htt97Q-EGFP aggregates, by cell to cell uptake, in cultured conditions resulting in an increasing population of dimers and tetramers compared to our controls. This study shows for the first time the impact of protein aggregation in the unexpanded Htt25Q-mCherry expressing cells that occurs from cell to cell transfer of the expanded Htt97Q-EGFP. These results signify the sporadic behavior of the polyQ inclusion that gives insight into the mechanism of protein dynamics as a consequence of secreted mHTT aggregates.
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Affiliation(s)
- Sara Sameni
- Laboratory for Fluorescence Dynamics, USA; Department of Biomedical Engineering, USA
| | - Run Zhang
- Laboratory for Fluorescence Dynamics, USA; Department of Biomedical Engineering, USA
| | - Michelle A Digman
- Laboratory for Fluorescence Dynamics, USA; Department of Biomedical Engineering, USA; Department of Developmental and Cell Biology, USA; Department of Chemical Engineering and Material Sciences, University of California, Irvine, USA.
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