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Johansson L, Sandberg A, Nyström S, Hammarström P, Hallbeck M. Amyloid beta 1-40 and 1-42 fibril ratios and maturation level cause conformational differences with minimal impact on autophagy and cytotoxicity. J Neurochem 2024; 168:3308-3322. [PMID: 39133499 DOI: 10.1111/jnc.16201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 07/02/2024] [Accepted: 07/25/2024] [Indexed: 08/13/2024]
Abstract
The amyloid β (Aβ) peptide has a central role in Alzheimer's disease (AD) pathology. The peptide length can vary between 37 and 49 amino acids, with Aβ1-42 being considered the most disease-related length. However, Aβ1-40 is also found in Aβ plaques and has shown to form intertwined fibrils with Aβ1-42. The peptides have previously also shown to form different fibril conformations, proposed to be related to disease phenotype. To conduct more representative in vitro experiments, it is vital to uncover the impact of different fibril conformations on neurons. Hence, we fibrillized different Aβ1-40:42 ratios in concentrations of 100:0, 90:10, 75:25, 50:50, 25:75, 10:90 and 0:100 for either 24 h (early fibrils) or 7 days (aged fibrils). These were then characterized based on fibril width, LCO-staining and antibody-staining. We further challenged differentiated neuronal-like SH-SY5Y human cells with the different fibrils and measured Aβ content, cytotoxicity and autophagy function at three different time-points: 3, 24, and 72 h. Our results revealed that both Aβ1-40:42 ratio and fibril maturation affect conformation of fibrils. We further show the impact of these conformation changes on the affinity to commonly used Aβ antibodies, primarily affecting Aβ1-40 rich aggregates. In addition, we demonstrate uptake of the aggregates by neuronally differentiated human cells, where aggregates with higher Aβ1-42 ratios generally caused higher cellular levels of Aβ. These differences in Aβ abundance did not cause changes in cytotoxicity nor in autophagy activation. Our results show the importance to consider conformational differences of Aβ fibrils, as this can have fundamental impact on Aβ antibody detection. Overall, these insights underline the need for further exploration of the impact of conformationally different fibrils and the need to reliably produce disease relevant Aβ aggregates.
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Affiliation(s)
- Lovisa Johansson
- Department of Biomedical and Clinical Sciences and Department of Clinical Pathology, Linköping University, Linköping, Sweden
| | - Alexander Sandberg
- Department of Biomedical and Clinical Sciences and Department of Clinical Pathology, Linköping University, Linköping, Sweden
| | - Sofie Nyström
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Per Hammarström
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden
| | - Martin Hallbeck
- Department of Biomedical and Clinical Sciences and Department of Clinical Pathology, Linköping University, Linköping, Sweden
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2
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Tehrani MJ, Matsuda I, Yamagata A, Kodama Y, Matsunaga T, Sato M, Toyooka K, McElheny D, Kobayashi N, Shirouzu M, Ishii Y. E22G Aβ40 fibril structure and kinetics illuminate how Aβ40 rather than Aβ42 triggers familial Alzheimer's. Nat Commun 2024; 15:7045. [PMID: 39147751 PMCID: PMC11327332 DOI: 10.1038/s41467-024-51294-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 08/05/2024] [Indexed: 08/17/2024] Open
Abstract
Arctic (E22G) mutation in amyloid-β (Aβ enhances Aβ40 fibril accumulation in Alzheimer's disease (AD). Unlike sporadic AD, familial AD (FAD) patients with the mutation exhibit more Aβ40 in the plaque core. However, structural details of E22G Aβ40 fibrils remain elusive, hindering therapeutic progress. Here, we determine a distinctive W-shaped parallel β-sheet structure through co-analysis by cryo-electron microscopy (cryoEM) and solid-state nuclear magnetic resonance (SSNMR) of in-vitro-prepared E22G Aβ40 fibrils. The E22G Aβ40 fibrils displays typical amyloid features in cotton-wool plaques in the FAD, such as low thioflavin-T fluorescence and a less compact unbundled morphology. Furthermore, kinetic and MD studies reveal previously unidentified in-vitro evidence that E22G Aβ40, rather than Aβ42, may trigger Aβ misfolding in the FAD, and prompt subsequent misfolding of wild-type (WT) Aβ40/Aβ42 via cross-seeding. The results provide insight into how the Arctic mutation promotes AD via Aβ40 accumulation and cross-propagation.
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Affiliation(s)
- Mohammad Jafar Tehrani
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan
| | - Isamu Matsuda
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan
| | - Atsushi Yamagata
- RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Yu Kodama
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan
| | - Tatsuya Matsunaga
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan
- RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Mayuko Sato
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Kiminori Toyooka
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Dan McElheny
- Department of Chemistry, University of Illinois at Chicago, 845 W Taylor St, Chicago, IL, 60607, USA
| | - Naohiro Kobayashi
- RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Mikako Shirouzu
- RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Yoshitaka Ishii
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan.
- RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
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3
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Im D, Choi TS. Distinctive contribution of two additional residues in protein aggregation of Aβ42 and Aβ40 isoforms. BMB Rep 2024; 57:263-272. [PMID: 38835114 PMCID: PMC11214890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/16/2024] [Accepted: 04/26/2024] [Indexed: 06/06/2024] Open
Abstract
Amyloid-β (Aβ) is one of the amyloidogenic intrinsically disordered proteins (IDPs) that self-assemble to protein aggregates, incurring cell malfunction and cytotoxicity. While Aβ has been known to regulate multiple physiological functions, such as enhancing synaptic functions, aiding in the recovery of the blood-brain barrier/brain injury, and exhibiting tumor suppression/antimicrobial activities, the hydrophobicity of the primary structure promotes pathological aggregations that are closely associated with the onset of Alzheimer's disease (AD). Aβ proteins consist of multiple isoforms with 37-43 amino acid residues that are produced by the cleavage of amyloid-β precursor protein (APP). The hydrolytic products of APP are secreted to the extracellular regions of neuronal cells. Aβ 1-42 (Aβ42) and Aβ 1-40 (Aβ40) are dominant isoforms whose significance in AD pathogenesis has been highlighted in numerous studies to understand the molecular mechanism and develop AD diagnosis and therapeutic strategies. In this review, we focus on the differences between Aβ42 and Aβ40 in the molecular mechanism of amyloid aggregations mediated by the two additional residues (Ile41 and Ala42) of Aβ42. The current comprehension of Aβ42 and Aβ40 in AD progression is outlined, together with the structural features of Aβ42/Aβ40 amyloid fibrils, and the aggregation mechanisms of Aβ42/Aβ40. Furthermore, the impact of the heterogeneous distribution of Aβ isoforms during amyloid aggregations is discussed in the system mimicking the coexistence of Aβ42 and Aβ40 in human cerebrospinal fluid (CSF) and plasma. [BMB Reports 2024; 57(6): 263-272].
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Affiliation(s)
- Dongjoon Im
- Department of Life Sciences, Korea University, Seoul 02841, Korea
| | - Tae Su Choi
- Department of Life Sciences, Korea University, Seoul 02841, Korea
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4
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Hu Y, Zhu T, Zhang W. The characteristics of brain atrophy prior to the onset of Alzheimer's disease: a longitudinal study. Front Aging Neurosci 2024; 16:1344920. [PMID: 38863784 PMCID: PMC11165148 DOI: 10.3389/fnagi.2024.1344920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 05/02/2024] [Indexed: 06/13/2024] Open
Abstract
Objective We aimed to use the onset time of Alzheimer's disease (AD) as the reference time to longitudinally investigate the atrophic characteristics of brain structures prior to the onset of AD. Materials and methods A total of 328 participants from the ADNI database with clear onset of AD and structural imaging data were included in our study. The time before the onset of AD (abbreviated as BAD) was calculated. We investigated the longitudinal brain changes in 97 regions using multivariate linear mixed effects regression models. Results The average BAD was -28.15 months, with a range from -156 to 0 months. The 54 brain regions showed significant atrophy prior to the onset of AD, and these regions were mainly distributed in the frontal and temporal lobes. The parietal and occipital lobe exhibited relatively less atrophy than the other brain lobes. Sex, age, and magnetic field strength had greater direct impacts on structural indicators than APOE genotype and education. The analysis of interaction effects revealed that the APOE ε4 mutation carriers exhibited more severe structural changes in specific brain regions as the BAD increased. However, sex, age, and education had minimal regulatory influence on the structural changes associated with BAD. Conclusion Longitudinal analysis, with the onset time point of AD as the reference, can accurately describe the features of structural changes preceding the onset of AD and provide a comprehensive understanding of AD development.
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Affiliation(s)
- Ying Hu
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
- West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, China
| | - Ting Zhu
- West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, China
| | - Wei Zhang
- West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, China
- Mental Health Center of West China Hospital, Sichuan University, Chengdu, China
- Med-X Center for Informatics, Sichuan University, Chengdu, China
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Tian Y, Shang Q, Liang R, Viles JH. Copper(II) Can Kinetically Trap Arctic and Italian Amyloid-β 40 as Toxic Oligomers, Mimicking Cu(II) Binding to Wild-Type Amyloid-β 42: Implications for Familial Alzheimer's Disease. JACS AU 2024; 4:578-591. [PMID: 38425915 PMCID: PMC10900208 DOI: 10.1021/jacsau.3c00687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 01/23/2024] [Accepted: 01/23/2024] [Indexed: 03/02/2024]
Abstract
The self-association of amyloid-β (Aβ) peptide into neurotoxic oligomers is believed to be central to Alzheimer's disease (AD). Copper is known to impact Aβ assembly, while disrupted copper homeostasis impacts phenotype in Alzheimer's models. Here we show the presence of substoichiometric Cu(II) has very different impacts on the assembly of Aβ40 and Aβ42 isoforms. Globally fitting microscopic rate constants for fibril assembly indicates copper will accelerate fibril formation of Aβ40 by increasing primary nucleation, while seeding experiments confirm that elongation and secondary nucleation rates are unaffected by Cu(II). In marked contrast, Cu(II) traps Aβ42 as prefibrillar oligomers and curvilinear protofibrils. Remarkably, the Cu(II) addition to preformed Aβ42 fibrils causes the disassembly of fibrils back to protofibrils and oligomers. The very different behaviors of the two Aβ isoforms are centered around differences in their fibril structures, as highlighted by studies of C-terminally amidated Aβ42. Arctic and Italian familiar mutations also support a key role for fibril structure in the interplay of Cu(II) with Aβ40/42 isoforms. The Cu(II) dependent switch in behavior between nonpathogenic Aβ40 wild-type and Aβ40 Arctic or Italian mutants suggests heightened neurotoxicity may be linked to the impact of physiological Cu(II), which traps these familial mutants as oligomers and curvilinear protofibrils, which cause membrane permeability and Ca(II) cellular influx.
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Affiliation(s)
- Yao Tian
- School of Biological and Behavioral
Sciences, Queen Mary University of London, London E1 4NS, U.K.
| | - Qi Shang
- School of Biological and Behavioral
Sciences, Queen Mary University of London, London E1 4NS, U.K.
| | - Ruina Liang
- School of Biological and Behavioral
Sciences, Queen Mary University of London, London E1 4NS, U.K.
| | - John H. Viles
- School of Biological and Behavioral
Sciences, Queen Mary University of London, London E1 4NS, U.K.
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Lu LP, Chang WH, Huang JJ, Tan P, Tsai GE. Lithium Benzoate Exerts Neuroprotective Effect by Improving Mitochondrial Function, Attenuating Reactive Oxygen Species, and Protecting Cognition and Memory in an Animal Model of Alzheimer’s Disease. J Alzheimers Dis Rep 2022; 6:557-575. [PMID: 36275418 PMCID: PMC9535606 DOI: 10.3233/adr-220025] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 08/09/2022] [Indexed: 11/15/2022] Open
Abstract
Background: Alzheimer’s disease (AD) is a multifactorial neurodegenerative disease affecting many cellular pathways, including protein aggregation, mitochondrial dysfunction, oxidative stress (OS), and neuroinflammation. Currently, no effective treatment for AD exists. Objective: We aim to determine the effect of lithium benzoate (LiBen) in protecting neurons from amyloid-β (Aβ) or other neurotoxin insults. Methods: Primary rat cortical neurons co-treated with neurotoxins and LiBen were used to examine its effect in cell viability, reactive oxygen species (ROS) clearance, and mitochondrial functions by MTT, CellRox fluorescence staining, and seahorse assay. Then, Barnes maze and prepulse inhibition test were performed in APP/PS1 mice that received chronic LiBen treatment to assess its effect on cognitive protection. Oral bioavailability of LiBen was also assessed by pharmacokinetic study in rat plasma. Results: In this study, we discovered that LiBen can attenuate cellular ROS level, improve mitochondrial function, increase cell viability against multiple different insults of mitochondrial dysfunction, Aβ accumulation, and neuroinflammation, and promote neurogenesis. We demonstrated that LiBen has advantages over lithium or sodium benzoate alone as LiBen displays superior neuroprotective efficacy and oral bioavailability than the other two agents when being applied either alone or in combination. Furthermore, chronic administration of LiBen showed protection for cognition as well as spatial memory and reduced the senile plaque deposition in brains of AD animal models. Conclusion: LiBen stands as a promising therapeutic agent for improving cognition and delaying the progression of AD.
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Affiliation(s)
- Lu-Ping Lu
- Department of Research and Development, SyneuRx International (Taiwan) Corp., New Taipei, Taiwan
| | - Wei-Hua Chang
- Department of Research and Development, SyneuRx International (Taiwan) Corp., New Taipei, Taiwan
| | - Jing-Jia Huang
- Department of Research and Development, SyneuRx International (Taiwan) Corp., New Taipei, Taiwan
| | - Peng Tan
- Department of Research and Development, SyneuRx International (Taiwan) Corp., New Taipei, Taiwan
| | - Guochuan Emil Tsai
- Department of Research and Development, SyneuRx International (Taiwan) Corp., New Taipei, Taiwan
- UCLA School of Medicine, Los Angeles, CA, USA
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7
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Liang R, Tian Y, Viles JH. Cross-seeding of WT amyloid-β with Arctic but not Italian familial mutants accelerates fibril formation in Alzheimer's disease. J Biol Chem 2022; 298:102071. [PMID: 35643314 PMCID: PMC9243174 DOI: 10.1016/j.jbc.2022.102071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 01/21/2023] Open
Abstract
Alzheimer’s disease (AD) involves the neurotoxic self-assembly of a 40 and 42 residue peptide, Amyloid-β (Aβ). Inherited early-onset AD can be caused by single point mutations within the Aβ sequence, including Arctic (E22G) and Italian (E22K) familial mutants. These mutations are heterozygous, resulting in an equal proportion of the WT and mutant Aβ isoform expression. It is therefore important to understand how these mixtures of Aβ isoforms interact with each other and influence the kinetics and morphology of their assembly into oligomers and fibrils. Using small amounts of nucleating fibril seeds, here, we systematically monitored the kinetics of fibril formation, comparing self-seeding with cross-seeding behavior of a range of isoform mixtures of Aβ42 and Aβ40. We confirm that Aβ40(WT) does not readily cross-seed Aβ42(WT) fibril formation. In contrast, fibril formation of Aβ40(Arctic) is hugely accelerated by Aβ42(WT) fibrils, causing an eight-fold reduction in the lag-time to fibrillization. We propose that cross-seeding between the more abundant Aβ40(Arctic) and Aβ42(WT) may be important for driving early-onset AD and will propagate fibril morphology as indicated by fibril twist periodicity. This kinetic behavior is not emulated by the Italian mutant, where minimal cross-seeding is observed. In addition, we studied the cross-seeding behavior of a C-terminal-amidated Aβ42 analog to probe the coulombic charge interplay between Glu22/Asp23/Lys28 and the C-terminal carboxylate. Overall, these studies highlight the role of cross-seeding between WT and mutant Aβ40/42 isoforms, which can impact the rate and structure of fibril assembly.
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Affiliation(s)
- Ruina Liang
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, United Kingdom
| | - Yao Tian
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, United Kingdom
| | - John H Viles
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, United Kingdom.
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8
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Lin L, Hua F, Salinas C, Young C, Bussiere T, Apgar JF, Burke JM, Kandadi Muralidharan K, Rajagovindan R, Nestorov I. Quantitative systems pharmacology model for Alzheimer's disease to predict the effect of aducanumab on brain amyloid. CPT Pharmacometrics Syst Pharmacol 2022; 11:362-372. [PMID: 35029320 PMCID: PMC8923729 DOI: 10.1002/psp4.12759] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/20/2021] [Accepted: 12/29/2021] [Indexed: 12/25/2022] Open
Abstract
Alzheimer's disease (AD) is an irreversible, progressive brain disorder that impairs memory and cognitive function. Dysregulation of the amyloid-β (Aβ) pathway and amyloid plaque accumulation in the brain are hallmarks of AD. Aducanumab is a human, immunoglobulin gamma 1 monoclonal antibody targeting aggregated forms of Aβ. In phase Ib and phase III studies, aducanumab reduced Aβ plaques in a dose dependent manner, as measured by standard uptake value ratio of amyloid positron emission tomography imaging. The goal of this work was to develop a quantitative systems pharmacology model describing the production, aggregation, clearance, and transport of Aβ as well as the mechanism of action for the drug to understand the relationship between aducanumab dosing regimens and changes of different Aβ species, particularly plaques in the brain. The model was used to better understand the pharmacodynamic effects observed in the clinical trials of aducanumab and assist in the clinical development of future Aβ therapies.
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Affiliation(s)
- Lin Lin
- BiogenCambridgeMassachusettsUSA
| | - Fei Hua
- Applied BioMath, LLCConcordMassachusettsUSA
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9
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Welty S, Thathiah A, Levine AS. DNA Damage Increases Secreted Aβ40 and Aβ42 in Neuronal Progenitor Cells: Relevance to Alzheimer's Disease. J Alzheimers Dis 2022; 88:177-190. [PMID: 35570488 PMCID: PMC9277680 DOI: 10.3233/jad-220030] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2022] [Indexed: 01/12/2023]
Abstract
BACKGROUND Recent studies suggest a strong association between neuronal DNA damage, elevated levels of amyloid-β (Aβ), and regions of the brain that degenerate in Alzheimer's disease (AD). OBJECTIVE To investigate the nature of this association, we tested the hypothesis that extensive DNA damage leads to an increase in Aβ40 and Aβ42 generation. METHODS We utilized an immortalized human neuronal progenitor cell line (NPCs), ReN VM GA2. NPCs or 20 day differentiated neurons were treated with hydrogen peroxide or etoposide and allowed to recover for designated times. Sandwich ELISA was used to assess secreted Aβ40 and Aβ42. Western blotting, immunostaining, and neutral comet assay were used to evaluate the DNA damage response and processes indicative of AD pathology. RESULTS We determined that global hydrogen peroxide damage results in increased cellular Aβ40 and Aβ42 secretion 24 h after treatment in ReN GA2 NPCs. Similarly, DNA double strand break (DSB)-specific etoposide damage leads to increased Aβ40 and Aβ42 secretion 2 h and 4 h after treatment in ReN GA2 NPCs. In contrast, etoposide damage does not increase Aβ40 and Aβ42 secretion in post-mitotic ReN GA2 neurons. CONCLUSION These findings provide evidence that in our model, DNA damage is associated with an increase in Aβ secretion in neuronal progenitors, which may contribute to the early stages of neuronal pathology in AD.
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Affiliation(s)
- Starr Welty
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Amantha Thathiah
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- University of Pittsburgh Brain Institute, Pittsburgh, PA, USA
- Pittsburgh Institute of Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
| | - Arthur Samuel Levine
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- University of Pittsburgh Brain Institute, Pittsburgh, PA, USA
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10
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Madrasi K, Das R, Mohmmadabdul H, Lin L, Hyman BT, Lauffenburger DA, Albers MW, Rissman RA, Burke JM, Apgar JF, Wille L, Gruenbaum L, Hua F. Systematic in silico analysis of clinically tested drugs for reducing amyloid-beta plaque accumulation in Alzheimer's disease. Alzheimers Dement 2021; 17:1487-1498. [PMID: 33938131 PMCID: PMC8478725 DOI: 10.1002/alz.12312] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 01/21/2021] [Accepted: 01/21/2021] [Indexed: 01/28/2023]
Abstract
Introduction Despite strong evidence linking amyloid beta (Aβ) to Alzheimer's disease, most clinical trials have shown no clinical efficacy for reasons that remain unclear. To understand why, we developed a quantitative systems pharmacology (QSP) model for seven therapeutics: aducanumab, crenezumab, solanezumab, bapineuzumab, elenbecestat, verubecestat, and semagacestat. Methods Ordinary differential equations were used to model the production, transport, and aggregation of Aβ; pharmacology of the drugs; and their impact on plaque. Results The calibrated model predicts that endogenous plaque turnover is slow, with an estimated half‐life of 2.75 years. This is likely why beta‐secretase inhibitors have a smaller effect on plaque reduction. Of the mechanisms tested, the model predicts binding to plaque and inducing antibody‐dependent cellular phagocytosis is the best approach for plaque reduction. Discussion A QSP model can provide novel insights to clinical results. Our model explains the results of clinical trials and provides guidance for future therapeutic development.
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Affiliation(s)
| | | | | | - Lin Lin
- Applied Biomath, Concord, Massachusetts, USA
| | - Bradley T Hyman
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Douglas A Lauffenburger
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Mark W Albers
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Robert A Rissman
- Department of Neurosciences, UCSD School of Medicine, La Jolla, California, USA
| | | | | | - Lucia Wille
- Applied Biomath, Concord, Massachusetts, USA
| | | | - Fei Hua
- Applied Biomath, Concord, Massachusetts, USA
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11
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Ji X, Wang H, Zhu M, He Y, Zhang H, Chen X, Gao W, Fu Y. Brainstem atrophy in the early stage of Alzheimer's disease: a voxel-based morphometry study. Brain Imaging Behav 2021; 15:49-59. [PMID: 31898091 DOI: 10.1007/s11682-019-00231-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Postmortem studies on patients with Alzheimer's disease (AD) have confirmed that the dorsal raphe nucleus (DRN) in the brainstem is the first brain structure affected in the earliest stage of AD. The present study examined the brainstem in the early stage of AD using magnetic resonance (MR) imaging. T1-weighted MR images of the brains of 81 subjects were obtained from the publicly available Open Access Series of Imaging Studies (OASIS) database, including 27 normal control (NC) subjects, 27 patients with very mild AD (AD-VM) and 27 patients with mild AD (AD-M). The brainstem was interactively segmented from the MR images using ITK-SNAP. The present voxel-based morphometry (VBM) study was designed to investigate the brainstem differences between the AD-VM/AD-M groups and the NC group. The results showed bilateral loss in the pons and the left part of the midbrain in the AD-M group compared to the NC group. The AD-M group showed greater loss in the left midbrain than the AD-VM group (PFWEcorrected < 0.05). The results revealed that brainstem atrophy occurs in the early stages of AD (Clinical Dementia Rating = 0.5 and 1.0). Most of these findings were also investigated in a multicenter dataset. This is the first VBM study that provides evidence of brainstem alterations in the early stage of AD.
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Affiliation(s)
- Xiaoxi Ji
- School of Life Science and Technology, Harbin Institute of Technology, Building 2E-417, 2 Yikuang Street, Nangang District, Harbin, Heilongjiang Province, China.,Guangzhou Medical University, Guangzhou, China.,Department of Neurosurgery, Third People's Hospital of Hainan Province, 146 Jiefang Road, Sanya, Hainan Province, China
| | - Hui Wang
- Department of Neurosurgery, Third People's Hospital of Hainan Province, 146 Jiefang Road, Sanya, Hainan Province, China
| | - Minwei Zhu
- Department of Neurosurgery, First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yingjie He
- Guangzhou Medical University, Guangzhou, China.,Department of Neurosurgery, Third People's Hospital of Hainan Province, 146 Jiefang Road, Sanya, Hainan Province, China
| | - Hong Zhang
- Guangzhou Medical University, Guangzhou, China.,Department of Neurosurgery, Third People's Hospital of Hainan Province, 146 Jiefang Road, Sanya, Hainan Province, China
| | - Xiaoguang Chen
- Department of Neurosurgery, Third People's Hospital of Hainan Province, 146 Jiefang Road, Sanya, Hainan Province, China.
| | - Wenpeng Gao
- School of Life Science and Technology, Harbin Institute of Technology, Building 2E-417, 2 Yikuang Street, Nangang District, Harbin, Heilongjiang Province, China.
| | - Yili Fu
- School of Life Science and Technology, Harbin Institute of Technology, Building 2E-417, 2 Yikuang Street, Nangang District, Harbin, Heilongjiang Province, China
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12
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Chong JR, Ashton NJ, Karikari TK, Tanaka T, Saridin FN, Reilhac A, Robins EG, Nai YH, Vrooman H, Hilal S, Zetterberg H, Blennow K, Lai MKP, Chen CP. Plasma P-tau181 to Aβ42 ratio is associated with brain amyloid burden and hippocampal atrophy in an Asian cohort of Alzheimer's disease patients with concomitant cerebrovascular disease. Alzheimers Dement 2021; 17:1649-1662. [PMID: 33792168 DOI: 10.1002/alz.12332] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 02/01/2021] [Accepted: 02/18/2021] [Indexed: 12/20/2022]
Abstract
INTRODUCTION There is increasing evidence that phosphorylated tau (P-tau181) is a specific biomarker for Alzheimer's disease (AD) pathology, but its potential utility in non-White patient cohorts and patients with concomitant cerebrovascular disease (CeVD) is unknown. METHODS Single molecule array (Simoa) measurements of plasma P-tau181, total tau, amyloid beta (Aβ)40 and Aβ42, as well as derived ratios were correlated with neuroimaging modalities indicating brain amyloid (Aβ+), hippocampal atrophy, and CeVD in a Singapore-based cohort of non-cognitively impaired (NCI; n = 43), cognitively impaired no dementia (CIND; n = 91), AD (n = 44), and vascular dementia (VaD; n = 22) subjects. RESULTS P-tau181/Aβ42 ratio showed the highest area under the curve (AUC) for Aβ+ (AUC = 0.889) and for discriminating between AD Aβ+ and VaD Aβ- subjects (AUC = 0.903). In addition, P-tau181/Aβ42 ratio was associated with hippocampal atrophy. None of the biomarkers was associated with CeVD. DISCUSSION Plasma P-tau181/Aβ42 ratio may be a noninvasive means of identifying AD with elevated brain amyloid in populations with concomitant CeVD.
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Affiliation(s)
- Joyce R Chong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore.,Memory, Aging and Cognition Centre, National University Health Systems, Kent Ridge, Singapore
| | - Nicholas J Ashton
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.,Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden.,Psychology and Neuroscience, King's College London, Institute of Psychiatry, Maurice Wohl Institute Clinical Neuroscience Institute, London, UK.,NIHR Biomedical Research Centre for Mental Health and Biomedical Research Unit for Dementia at South London and Maudsley NHS Foundation, London, UK
| | - Thomas K Karikari
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | - Tomotaka Tanaka
- Memory, Aging and Cognition Centre, National University Health Systems, Kent Ridge, Singapore.,Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.,Clinical Imaging Research Centre, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore
| | - Francis N Saridin
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore.,Memory, Aging and Cognition Centre, National University Health Systems, Kent Ridge, Singapore
| | - Anthonin Reilhac
- Clinical Imaging Research Centre, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore
| | - Edward G Robins
- Clinical Imaging Research Centre, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore.,Technology and Research, Biopolis, Singapore Bioimaging Consortium, A*Star Agency for Science, Singapore
| | - Ying-Hwey Nai
- Clinical Imaging Research Centre, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore
| | - Henri Vrooman
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Saima Hilal
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore.,Memory, Aging and Cognition Centre, National University Health Systems, Kent Ridge, Singapore.,Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Kent Ridge, Singapore
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.,UK Dementia Research Institute at UCL, London, UK.,Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore.,Memory, Aging and Cognition Centre, National University Health Systems, Kent Ridge, Singapore
| | - Christopher P Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore.,Memory, Aging and Cognition Centre, National University Health Systems, Kent Ridge, Singapore
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Abstract
The history of Alzheimer's disease (AD) started in 1907, but we needed to wait until the end of the century to identify the components of pathological hallmarks and genetic subtypes and to formulate the first pathogenic hypothesis. Thanks to biomarkers and new technologies, the concept of AD then rapidly changed from a static view of an amnestic dementia of the presenium to a biological entity that could be clinically manifested as normal cognition or dementia of different types. What is clearly emerging from studies is that AD is heterogeneous in each aspect, such as amyloid composition, tau distribution, relation between amyloid and tau, clinical symptoms, and genetic background, and thus it is probably impossible to explain AD with a single pathological process. The scientific approach to AD suffers from chronological mismatches between clinical, pathological, and technological data, causing difficulty in conceiving diagnostic gold standards and in creating models for drug discovery and screening. A recent mathematical computer-based approach offers the opportunity to study AD in real life and to provide a new point of view and the final missing pieces of the AD puzzle.
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Affiliation(s)
- Camilla Ferrari
- Department of Neuroscience, Psychology, Drug Research, and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Sandro Sorbi
- Department of Neuroscience, Psychology, Drug Research, and Child Health (NEUROFARBA), University of Florence, Florence, Italy.,IRCCS Fondazione Don Carlo Gnocchi, Florence, Italy
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14
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Liang JH, Wang C, Huo XK, Tian XG, Zhao WY, Wang X, Sun CP, Ma XC. The genus Uncaria: A review on phytochemical metabolites and biological aspects. Fitoterapia 2020; 147:104772. [PMID: 33152463 DOI: 10.1016/j.fitote.2020.104772] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/03/2020] [Accepted: 10/25/2020] [Indexed: 12/14/2022]
Abstract
The genus Uncaira (Rubiaceae) comprises of 34 species, many of which are usually used as traditional Chinese medicines (TCMs) to treat hypertension, fever, headache, gastrointestinal illness, and fungal infection. Over the past twenty years, Uncaira species have been paid the considerable attentions in phytochemical and biological aspects, and about 100 new secondary metabolites, including alkaloids, triterpenes, and flavonoids, have been elucidated. This review aims to present a comprehensive and up-to date overview of the biological source, structures and their biosynthetic pathways, as well as the pharmacological of the compounds reported in the genus Uncaria for the past two decades. It would provide an insight into the emerging pharmacological applications of the genus Uncaria.
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Affiliation(s)
- Jia-Hao Liang
- College of Pharmacy, College of Integrative Medicine, Dalian Medical University, Dalian, China; Dalian Key Laboratory of Metabolic Target Characterization and Traditional Chinese Medicine Intervention, Dalian Medical University, Dalian, China
| | - Chao Wang
- College of Pharmacy, College of Integrative Medicine, Dalian Medical University, Dalian, China; Dalian Key Laboratory of Metabolic Target Characterization and Traditional Chinese Medicine Intervention, Dalian Medical University, Dalian, China
| | - Xiao-Kui Huo
- College of Pharmacy, College of Integrative Medicine, Dalian Medical University, Dalian, China; Dalian Key Laboratory of Metabolic Target Characterization and Traditional Chinese Medicine Intervention, Dalian Medical University, Dalian, China
| | - Xiang-Ge Tian
- College of Pharmacy, College of Integrative Medicine, Dalian Medical University, Dalian, China; Dalian Key Laboratory of Metabolic Target Characterization and Traditional Chinese Medicine Intervention, Dalian Medical University, Dalian, China
| | - Wen-Yu Zhao
- College of Pharmacy, College of Integrative Medicine, Dalian Medical University, Dalian, China; Dalian Key Laboratory of Metabolic Target Characterization and Traditional Chinese Medicine Intervention, Dalian Medical University, Dalian, China
| | - Xun Wang
- Department of Neurosurgery, The Third People's Hospital of Dalian, Non-Directly Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Cheng-Peng Sun
- College of Pharmacy, College of Integrative Medicine, Dalian Medical University, Dalian, China; Dalian Key Laboratory of Metabolic Target Characterization and Traditional Chinese Medicine Intervention, Dalian Medical University, Dalian, China.
| | - Xiao-Chi Ma
- College of Pharmacy, College of Integrative Medicine, Dalian Medical University, Dalian, China; Dalian Key Laboratory of Metabolic Target Characterization and Traditional Chinese Medicine Intervention, Dalian Medical University, Dalian, China.
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15
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Kent SA, Spires-Jones TL, Durrant CS. The physiological roles of tau and Aβ: implications for Alzheimer's disease pathology and therapeutics. Acta Neuropathol 2020; 140:417-447. [PMID: 32728795 PMCID: PMC7498448 DOI: 10.1007/s00401-020-02196-w] [Citation(s) in RCA: 208] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 01/18/2023]
Abstract
Tau and amyloid beta (Aβ) are the prime suspects for driving pathology in Alzheimer's disease (AD) and, as such, have become the focus of therapeutic development. Recent research, however, shows that these proteins have been highly conserved throughout evolution and may have crucial, physiological roles. Such functions may be lost during AD progression or be unintentionally disrupted by tau- or Aβ-targeting therapies. Tau has been revealed to be more than a simple stabiliser of microtubules, reported to play a role in a range of biological processes including myelination, glucose metabolism, axonal transport, microtubule dynamics, iron homeostasis, neurogenesis, motor function, learning and memory, neuronal excitability, and DNA protection. Aβ is similarly multifunctional, and is proposed to regulate learning and memory, angiogenesis, neurogenesis, repair leaks in the blood-brain barrier, promote recovery from injury, and act as an antimicrobial peptide and tumour suppressor. This review will discuss potential physiological roles of tau and Aβ, highlighting how changes to these functions may contribute to pathology, as well as the implications for therapeutic development. We propose that a balanced consideration of both the physiological and pathological roles of tau and Aβ will be essential for the design of safe and effective therapeutics.
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Affiliation(s)
- Sarah A. Kent
- Translational Neuroscience PhD Programme, Centre for Discovery Brain Sciences and the UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ Scotland, UK
| | - Tara L. Spires-Jones
- Centre for Discovery Brain Sciences and the UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ Scotland, UK
| | - Claire S. Durrant
- Centre for Discovery Brain Sciences and the UK Dementia Research Institute, The University of Edinburgh, 1 George Square, Edinburgh, EH8 9JZ Scotland, UK
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16
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Candreva J, Chau E, Rice ME, Kim JR. Interactions between Soluble Species of β-Amyloid and α-Synuclein Promote Oligomerization while Inhibiting Fibrillization. Biochemistry 2019; 59:425-435. [PMID: 31854188 DOI: 10.1021/acs.biochem.9b00655] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aggregations of β-amyloid (Aβ) and α-synuclein (αS) into oligomeric and fibrillar assemblies are the pathological hallmarks of Alzheimer's and Parkinson's diseases, respectively. Although Aβ and αS affect different regions of the brain and are separated at the cellular level, there is evidence of their eventual interaction in the pathology of both disorders. Characterization of interactions of Aβ and αS at various stages of their aggregation pathways could reveal mechanisms and therapeutic targets for the prevention and cure of these neurodegenerative diseases. In this study, we comprehensively examined the interactions and their molecular manifestations using an array of characterization tools. We show for the first time that αS monomers and oligomers, but not αS fibrils, inhibit Aβ fibrillization while promoting oligomerization of Aβ monomers and stabilizing preformed Aβ oligomers via coassembly, as judged by Thioflavin T fluorescence, transmission electron microscopy, and SDS- and native-PAGE with fluorescently labeled peptides/proteins. In contrast, soluble Aβ species, such as monomers and oligomers, aggregate into fibrils, when incubated alone under the otherwise same condition. Our study provides evidence that the interactions with αS soluble species, responsible for the effects, are mediated primarily by the C-terminus of Aβ, when judged by competitive immunoassays using antibodies recognizing various fragments of Aβ. We also show that the C-terminus of Aβ is a primary site for its interaction with αS fibrils. Collectively, these data demonstrate aggregation state-specific interactions between αS and Aβ and offer insight into a molecular basis of synergistic biological effects between the two polypeptides.
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Affiliation(s)
- Jason Candreva
- Department of Chemical and Biomolecular Engineering , New York University , 6 MetroTech Center , Brooklyn , New York 11201 , United States
| | - Edward Chau
- Department of Chemical and Biomolecular Engineering , New York University , 6 MetroTech Center , Brooklyn , New York 11201 , United States
| | - Margaret E Rice
- Departments of Neurosurgery, and Neuroscience and Physiology , New York University School of Medicine , New York , New York 10016 , United States
| | - Jin Ryoun Kim
- Department of Chemical and Biomolecular Engineering , New York University , 6 MetroTech Center , Brooklyn , New York 11201 , United States
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17
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Persistent Infection with Herpes Simplex Virus 1 and Alzheimer's Disease-A Call to Study How Variability in Both Virus and Host may Impact Disease. Viruses 2019; 11:v11100966. [PMID: 31635156 PMCID: PMC6833100 DOI: 10.3390/v11100966] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 10/14/2019] [Accepted: 10/14/2019] [Indexed: 02/06/2023] Open
Abstract
Increasing attention has focused on the contributions of persistent microbial infections with the manifestation of disease later in life, including neurodegenerative conditions such as Alzheimer’s disease (AD). Current data has shown the presence of herpes simplex virus 1 (HSV-1) in regions of the brain that are impacted by AD in elderly individuals. Additionally, neuronal infection with HSV-1 triggers the accumulation of amyloid beta deposits and hyperphosphorylated tau, and results in oxidative stress and synaptic dysfunction. All of these factors are implicated in the development of AD. These data highlight the fact that persistent viral infection is likely a contributing factor, rather than a sole cause of disease. Details of the correlations between HSV-1 infection and AD development are still just beginning to emerge. Future research should investigate the relative impacts of virus strain- and host-specific factors on the induction of neurodegenerative processes over time, using models such as infected neurons in vitro, and animal models in vivo, to begin to understand their relationship with cognitive dysfunction.
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18
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Chai YL, Xing H, Chong JR, Francis PT, Ballard CG, Chen CP, Lai MKP. Mitochondrial Translocase of the Outer Membrane Alterations May Underlie Dysfunctional Oxidative Phosphorylation in Alzheimer's Disease. J Alzheimers Dis 2019; 61:793-801. [PMID: 29254089 DOI: 10.3233/jad-170613] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The translocase of the outer membrane (TOM) is a vital mitochondrial transport system facilitating the importation of nuclear encoded proteins into the organelle. While mitochondrial dysfunction, including perturbation of oxidative phosphorylation (OXPHOS) complex, is evident in Alzheimer's disease (AD), it remains unclear whether the observed OXPHOS deficits may be associated with TOM alterations. OBJECTIVES To correlate TOM subunits with OXPHOS complex proteins in AD. METHODS Postmortem neocortex (BA40) from AD and age-matched controls were processed to obtain mitochondrial enriched homogenates for the measurement of Tom20, Tom22, Tom40, and Tom70 as well as components of OXPHOS complex I-V by immunoblotting. RESULTS Tom20 and Tom70 immunoreactivities were significantly reduced in AD, as were components of OXPHOS complex I and III. Both Tom20 and Tom70 positively correlated with complex III and V, while Tom20 also correlated withcomplex IV. CONCLUSION Reductions in certain TOM subunits and their correlations with specific OXPHOS complex proteins suggest that an impaired mitochondrial transportation system may contribute to previously observed oxidative phosphorylation deficits in AD. Follow-up studies are needed to corroborate the present correlative study.
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Affiliation(s)
- Yuek Ling Chai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Huayang Xing
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Joyce R Chong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Paul T Francis
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - Clive G Ballard
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK.,University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Christopher P Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Wolfson Centre for Age-Related Diseases, King's College London, London, UK
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19
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Rana M, Sharma AK. Cu and Zn interactions with Aβ peptides: consequence of coordination on aggregation and formation of neurotoxic soluble Aβ oligomers. Metallomics 2019; 11:64-84. [DOI: 10.1039/c8mt00203g] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The coordination chemistry of transition metal ions (Fe, Cu, Zn) with the amyloid-β (Aβ) peptides has attracted a lot of attention in recent years due to its repercussions in Alzheimer's disease (AD).
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Affiliation(s)
- Monika Rana
- Department of Chemistry
- Central University of Rajasthan
- Ajmer 305817
- India
| | - Anuj Kumar Sharma
- Department of Chemistry
- Central University of Rajasthan
- Ajmer 305817
- India
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20
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Hunter S, Smailagic N, Brayne C. Dementia Research: Populations, Progress, Problems, and Predictions. J Alzheimers Dis 2018; 64:S119-S143. [DOI: 10.3233/jad-179927] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Sally Hunter
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Nadja Smailagic
- Institute of Public Health, University of Cambridge, Cambridge, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Cambridge, UK
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21
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Swaminathan SK, Ahlschwede KM, Sarma V, Curran GL, Omtri RS, Decklever T, Lowe VJ, Poduslo JF, Kandimalla KK. Insulin differentially affects the distribution kinetics of amyloid beta 40 and 42 in plasma and brain. J Cereb Blood Flow Metab 2018; 38:904-918. [PMID: 28569090 PMCID: PMC5987944 DOI: 10.1177/0271678x17709709] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Impaired brain clearance of amyloid-beta peptides (Aβ) 40 and 42 across the blood-brain barrier (BBB) is believed to be one of the pathways responsible for Alzheimer's disease (AD) pathogenesis. Hyperinsulinemia prevalent in type II diabetes was shown to damage cerebral vasculature and increase Aβ accumulation in AD brain. However, there is no clarity on how aberrations in peripheral insulin levels affect Aβ accumulation in the brain. This study describes, for the first time, an intricate relation between plasma insulin and Aβ transport at the BBB. Upon peripheral insulin administration in wild-type mice: the plasma clearance of Aβ40 increased, but Aβ42 clearance reduced; the plasma-to-brain influx of Aβ40 increased, and that of Aβ42 reduced; and the clearance of intracerebrally injected Aβ40 decreased, whereas Aβ42 clearance increased. In hCMEC/D3 monolayers (in vitro BBB model) exposed to insulin, the luminal uptake and luminal-to-abluminal permeability of Aβ40 increased and that of Aβ42 reduced; the abluminal-to-luminal permeability of Aβ40 decreased, whereas Aβ42 permeability increased. Moreover, Aβ cellular trafficking machinery was altered. In summary, Aβ40 and Aβ42 demonstrated distinct distribution kinetics in plasma and brain compartments, and insulin differentially modulated their distribution. Cerebrovascular disease and metabolic disorders may disrupt this intricate homeostasis and aggravate AD pathology.
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Affiliation(s)
- Suresh Kumar Swaminathan
- 1 Department of Pharmaceutics and Brain Barriers Research Center, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA.,2 Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Kristen M Ahlschwede
- 1 Department of Pharmaceutics and Brain Barriers Research Center, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA.,3 Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Vidur Sarma
- 1 Department of Pharmaceutics and Brain Barriers Research Center, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA.,2 Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Geoffry L Curran
- 2 Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN, USA.,3 Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Rajesh S Omtri
- 1 Department of Pharmaceutics and Brain Barriers Research Center, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
| | - Teresa Decklever
- 2 Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Val J Lowe
- 2 Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Joseph F Poduslo
- 3 Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Karunya K Kandimalla
- 1 Department of Pharmaceutics and Brain Barriers Research Center, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA.,3 Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN, USA
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22
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Di Fede G, Catania M, Maderna E, Ghidoni R, Benussi L, Tonoli E, Giaccone G, Moda F, Paterlini A, Campagnani I, Sorrentino S, Colombo L, Kubis A, Bistaffa E, Ghetti B, Tagliavini F. Molecular subtypes of Alzheimer's disease. Sci Rep 2018; 8:3269. [PMID: 29459625 PMCID: PMC5818536 DOI: 10.1038/s41598-018-21641-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 02/07/2018] [Indexed: 12/21/2022] Open
Abstract
Protein misfolding and aggregation is a central feature of several neurodegenerative disorders including Alzheimer's disease (AD), in which assemblies of amyloid β (Aβ) peptides accumulate in the brain in the form of parenchymal and/or vascular amyloid. A widely accepted concept is that AD is characterized by distinct clinical and neuropathological phenotypes. Recent studies revealed that Aβ assemblies might have structural differences among AD brains and that such pleomorphic assemblies can correlate with distinct disease phenotypes. We found that in both sporadic and inherited forms of AD, amyloid aggregates differ in the biochemical composition of Aβ species. These differences affect the physicochemical properties of Aβ assemblies including aggregation kinetics, resistance to degradation by proteases and seeding ability. Aβ-amyloidosis can be induced and propagated in animal models by inoculation of brain extracts containing aggregated Aβ. We found that brain homogenates from AD patients with different molecular profiles of Aβ are able to induce distinct patterns of Aβ-amyloidosis when injected into mice. Overall these data suggest that the assembly of mixtures of Aβ peptides into different Aβ seeds leads to the formation of distinct subtypes of amyloid having distinctive physicochemical and biological properties which result in the generation of distinct AD molecular subgroups.
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Affiliation(s)
- Giuseppe Di Fede
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Marcella Catania
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Emanuela Maderna
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Roberta Ghidoni
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio - Fatebenefratelli, Brescia, Italy
| | - Luisa Benussi
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio - Fatebenefratelli, Brescia, Italy
| | - Elisa Tonoli
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio - Fatebenefratelli, Brescia, Italy
| | - Giorgio Giaccone
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Fabio Moda
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Anna Paterlini
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio - Fatebenefratelli, Brescia, Italy
| | | | | | - Laura Colombo
- Department of Molecular Biochemistry and Pharmacology, IRCCS Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Adriana Kubis
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
- Department of Toxicology, Wroclaw Medical University, Wrocław, Poland
| | - Edoardo Bistaffa
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Bernardino Ghetti
- Department of Pathology and Laboratory Medicine, Indiana University, Indianapolis, Indiana, USA
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23
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Tapia-Rojas C, Inestrosa NC. Wnt signaling loss accelerates the appearance of neuropathological hallmarks of Alzheimer's disease in J20-APP transgenic and wild-type mice. J Neurochem 2018; 144:443-465. [DOI: 10.1111/jnc.14278] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 11/29/2017] [Accepted: 12/06/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Cheril Tapia-Rojas
- Centro de Envejecimiento y Regeneración (CARE UC); Departamento de Biología Celular y Molecular; Facultad de Ciencias Biológicas; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Nibaldo C. Inestrosa
- Centro de Envejecimiento y Regeneración (CARE UC); Departamento de Biología Celular y Molecular; Facultad de Ciencias Biológicas; Pontificia Universidad Católica de Chile; Santiago Chile
- Centre for Healthy Brain Ageing; School of Psychiatry; Faculty of Medicine; University of New South Wales; Sydney New South Wales Australia
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA); Universidad de Magallanes; Punta Arenas Chile
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24
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Hunter S, Brayne C. Understanding the roles of mutations in the amyloid precursor protein in Alzheimer disease. Mol Psychiatry 2018; 23:81-93. [PMID: 29112196 DOI: 10.1038/mp.2017.218] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 08/23/2017] [Accepted: 08/24/2017] [Indexed: 12/16/2022]
Abstract
Many models of disease progression in Alzheimer's disease (AD) have been proposed to help guide experimental design and aid the interpretation of results. Models focussing on the genetic evidence include the amyloid cascade (ACH) and presenilin (PSH) hypotheses and the amyloid precursor protein (APP) matrix approach (AMA), of which the ACH has held a dominant position for over two decades. However, the ACH has never been fully accepted and has not yet delivered on its therapeutic promise. We review the ACH, PSH and AMA in relation to levels of APP proteolytic fragments reported from AD-associated mutations in APP. Different APP mutations have diverse effects on the levels of APP proteolytic fragments. This evidence is consistent with at least three disease pathways that can differ between familial and sporadic AD and two pathways associated with cerebral amyloid angiopathy. We cannot fully evaluate the ACH, PSH and AMA in relation to the effects of mutations in APP as the APP proteolytic system has not been investigated systematically. The confounding effects of sequence homology, complexity of competing cleavages and antibody cross reactivities all illustrate limitations in our understanding of the roles these fragments and the APP proteolytic system as a whole in normal aging and disease play. Current experimental design should be refined to generate clearer evidence, addressing both aging and complex disorders with standardised reporting formats. A more flexible theoretical framework capable of accommodating the complexity of the APP proteolytic system is required to integrate available evidence.
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Affiliation(s)
- S Hunter
- Department of Public Health and Primary Care, Institute of Public Health, Forvie Site University of Cambridge, School of Clinical Medicine, Cambridge, UK
| | - C Brayne
- Department of Public Health and Primary Care, Institute of Public Health, Forvie Site University of Cambridge, School of Clinical Medicine, Cambridge, UK
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Tapia-Rojas C, Inestrosa NC. Loss of canonical Wnt signaling is involved in the pathogenesis of Alzheimer's disease. Neural Regen Res 2018; 13:1705-1710. [PMID: 30136680 PMCID: PMC6128062 DOI: 10.4103/1673-5374.238606] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the older population, however, the precise cause of the disease is unknown. The neuropathology is characterized by the presence of aggregates formed by amyloid-β (Aβ) peptide and phosphorylated tau; which is accompanied by progressive impairment of memory. Diverse signaling pathways are linked to AD, and among these the Wnt signaling pathway is becoming increasingly relevant, since it plays essential roles in the adult brain. Initially, Wnt signaling activation was proposed as a neuroprotective mechanism against Aβ toxicity. Later, it was reported that it participates in tau phosphorylation and processes of learning and memory. Interestingly, in the last years we demonstrated that Wnt signaling is fundamental in amyloid precursor protein (APP) processing and that Wnt dysfunction results in Aβ production and aggregation in vitro. Recent in vivo studies reported that loss of canonical Wnt signaling exacerbates amyloid deposition in a transgenic (Tg) mouse model of AD. Finally, we showed that inhibition of Wnt signaling in a Tg mouse previously at the appearance of AD signs, resulted in memory loss, tau phosphorylation and Aβ formation and aggregation; indicating that Wnt dysfunction accelerated the onset of AD. More importantly, Wnt signaling loss promoted cognitive impairment, tau phosphorylation and Aβ1-42 production in the hippocampus of wild-type (WT) mice, contributing to the development of an Alzheimer's-like neurophatology. Therefore, in this review we highlight the importance of Wnt/β-catenin signaling dysfunction in the onset of AD and propose that the loss of canonical Wnt signaling is a triggering factor of AD.
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Affiliation(s)
- Cheril Tapia-Rojas
- Centro de Envejecimiento y Regeneración (CARE UC), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nibaldo C Inestrosa
- Centro de Envejecimiento y Regeneración (CARE UC), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago; Centre for Healthy Brain Ageing, School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, Australia; Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
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Lau A, Bourkas M, Lu YQQ, Ostrowski LA, Weber-Adrian D, Figueiredo C, Arshad H, Shoaei SZS, Morrone CD, Matan-Lithwick S, Abraham KJ, Wang H, Schmitt-Ulms G. Functional Amyloids and their Possible Influence on Alzheimer Disease. Discoveries (Craiova) 2017; 5:e79. [PMID: 32309597 PMCID: PMC7159844 DOI: 10.15190/d.2017.9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 09/29/2017] [Accepted: 10/02/2017] [Indexed: 12/21/2022] Open
Abstract
Amyloids play critical roles in human diseases but have increasingly been recognized to also exist naturally. Shared physicochemical characteristics of amyloids and of their smaller oligomeric building blocks offer the prospect of molecular interactions and crosstalk amongst these assemblies, including the propensity to mutually influence aggregation. A case in point might be the recent discovery of an interaction between the amyloid β peptide (Aβ) and somatostatin (SST). Whereas Aβ is best known for its role in Alzheimer disease (AD) as the main constituent of amyloid plaques, SST is intermittently stored in amyloid-form in dense core granules before its regulated release into the synaptic cleft. This review was written to introduce to readers a large body of literature that surrounds these two peptides. After introducing general concepts and recent progress related to our understanding of amyloids and their aggregation, the review focuses separately on the biogenesis and interactions of Aβ and SST, before attempting to assess the likelihood of encounters of the two peptides in the brain, and summarizing key observations linking SST to the pathobiology of AD. While the review focuses on Aβ and SST, it is to be anticipated that crosstalk amongst functional and disease-associated amyloids will emerge as a general theme with much broader significance in the etiology of dementias and other amyloidosis.
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Affiliation(s)
- Angus Lau
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, Ontario M5T 2S8, Canada
| | - Matthew Bourkas
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, Ontario M5T 2S8, Canada
| | - Yang Qing Qin Lu
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Lauren Anne Ostrowski
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Danielle Weber-Adrian
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Carlyn Figueiredo
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Hamza Arshad
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, Ontario M5T 2S8, Canada
| | - Seyedeh Zahra Shams Shoaei
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Christopher Daniel Morrone
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Stuart Matan-Lithwick
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Karan Joshua Abraham
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Hansen Wang
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, Ontario M5T 2S8, Canada
| | - Gerold Schmitt-Ulms
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Medical Sciences Building, 6th Floor, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, 6th Floor, 60 Leonard Avenue, Toronto, Ontario M5T 2S8, Canada
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Dutta M, Mattaparthi VSK. In silico investigation on the inhibition of Aβ 42 aggregation by Aβ 40 peptide by potential of mean force study. J Biomol Struct Dyn 2017; 36:741-752. [PMID: 28278027 DOI: 10.1080/07391102.2017.1296783] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Recent experimental data revealed that small, soluble Amyloid beta (Aβ42) oligomers, especially dimers impair synaptic plasticity and memory leading to Alzheimer's disease. Here, we have studied dimerization of Aβ42/Aβ42 homo-dimer and Aβ40/Aβ42 hetero-dimer in terms of free energy profile by all-atom simulations using the ff99SB force field. We have found that in the presence of Aβ40 peptide, there exists a strong tendency to form a hetero-dimer with Aβ42 peptide, suggesting that a possible co-oligomerization. Furthermore, we have investigated the effects of Aβ40 on the Aβ42 peptide. Our study also shows that in presence of Aβ40, the beta-content of Aβ42 monomer is reduced. Additionally, certain residues important for bending in Aβ42 peptide attained an increased flexibility in the presence of Aβ40. The salt-bridge destabilization also manifested the impact of Aβ40 on Aβ42 peptide as a whole. Based on this, one may expect that Aβ40 inhibits the aggregation propensity of Aβ42. Moreover, the binding free energy obtained by the molecular mechanics-Poisson-Boltzmann surface area method also revealed a strong affinity between the two isoforms thereby suggests that Aβ40 binding induces conformational change in Aβ42. Our results suggest that co-oligomerization of Aβ isoforms may play a substantial role in Alzheimer's disease.
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Affiliation(s)
- Mary Dutta
- a Department of Molecular Biology and Biotechnology , Tezpur University , Tezpur 784 028 , Assam , India
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28
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You F, Li Q, Jin G, Zheng Y, Chen J, Yang H. Genistein protects against Aβ 25-35 induced apoptosis of PC12 cells through JNK signaling and modulation of Bcl-2 family messengers. BMC Neurosci 2017; 18:12. [PMID: 28081713 PMCID: PMC5234099 DOI: 10.1186/s12868-016-0329-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 12/27/2016] [Indexed: 01/22/2023] Open
Abstract
Background Deposition of aggregated amyloid beta (Aβ) protein is hallmark of Alzheimer’s disease, leading to dysfunction and apoptosis of neurons. The isoflavone phytoestrogen compound genistein (Gen) exerts a significant protective effect against Aβ25–35 induced neurotoxicity and mitochondrial damage in rat pheochromocytoma (PC12) cells. However, the mechanisms underlying Gen’s rescue remain elusive. Therefore we endeavored to research further the molecular mechanisms underlying Gen’s inhibition of Aβ25–35 induced apoptosis of neurons. Results We found that Gen dramatically suppressed the activation by Aβ25–35 of p-c-Jun N-terminal kinase (p-JNK), and also inhibited the JNK-dependent decreased of Bcl-w and increased of Bim. Furthermore, Gen significantly reduced the cytoplasmic concentrations of cytochrome c and Smac protein as well as caspase-3 activity. Additionally, pretreatment with JNK inhibitor SP600125 effectively suppressed Aβ25–35 induced PC12 cell cytotoxicity. Conclusion Taken together, the results suggested that Gen protects PC12 cells from Aβ25–35 induced neurotoxicity by interfering with p-JNK activation, thus attenuating the JNK-dependent apoptosis through the mitochondrial pathway. These findings constitute novel insights into the pathway for Aβ25–35 toxicity, and the neuroprotective action of Gen. Electronic supplementary material The online version of this article (doi:10.1186/s12868-016-0329-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fuling You
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China
| | - Qiao Li
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China
| | - Guifang Jin
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China
| | - Yaojie Zheng
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China
| | - Jingrong Chen
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China
| | - Hong Yang
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China.
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29
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Upregulation of Aβ42 in the Brain and Bodily Fluids of Rhesus Monkeys with Aging. J Mol Neurosci 2016; 61:79-87. [PMID: 27647310 DOI: 10.1007/s12031-016-0840-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 09/06/2016] [Indexed: 10/21/2022]
Abstract
The cerebral accumulation of amyloid beta (Aβ) is one of the key pathological hallmarks of Alzheimer's disease (AD). Aβ is also found in bodily fluids such as the cerebrospinal fluid (CSF) and plasma. However, the significance of Aβ accumulation in the brain and different bodily pools, as well as its correlation with aging and cerebral amyloid pathology, is not completely understood. To better understand this question, we selected the rhesus monkey, which is phylogenetically and physiologically highly similar to the human, as a model to study. We quantified the levels of the two main Aβ isoforms (Aβ42 and Aβ40) in different sections of the brain (frontal cortex, temporal cortex, and hippocampus) and bodily fluids (CSF and plasma) of rhesus monkeys at different developmental phases (young, 5-9 years of age; mature, 10-19 years of age; and old, 21-24 years of age). We found that the levels of neuronal and insoluble Aβ42 increased significantly in the brain with aging, suggesting that this specific isoform might be directly involved in aging and AD-like pathophysiology. There was no significant change in the Aβ40 level in the brain with aging. In addition, the Aβ42 level, but not the Aβ40 level, in both the CSF and plasma increased with aging. We also identified a positive correlation between Aβ42 in the CSF and plasma and Aβ42 in the brain. Taken collectively, our results indicate that there is an association between Aβ accumulation and age. These results support the increased incidence of AD with aging.
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30
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Iljina M, Garcia GA, Dear AJ, Flint J, Narayan P, Michaels TCT, Dobson CM, Frenkel D, Knowles TPJ, Klenerman D. Quantitative analysis of co-oligomer formation by amyloid-beta peptide isoforms. Sci Rep 2016; 6:28658. [PMID: 27346247 PMCID: PMC4921824 DOI: 10.1038/srep28658] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 06/07/2016] [Indexed: 01/01/2023] Open
Abstract
Multiple isoforms of aggregation-prone proteins are present under physiological conditions and have the propensity to assemble into co-oligomers with different properties from self-oligomers, but this process has not been quantitatively studied to date. We have investigated the amyloid-β (Aβ) peptide, associated with Alzheimer’s disease, and the aggregation of its two major isoforms, Aβ40 and Aβ42, using a statistical mechanical modelling approach in combination with in vitro single-molecule fluorescence measurements. We find that at low concentrations of Aβ, corresponding to its physiological abundance, there is little free energy penalty in forming co-oligomers, suggesting that the formation of both self-oligomers and co-oligomers is possible under these conditions. Our model is used to predict the oligomer concentration and size at physiological concentrations of Aβ and suggests the mechanisms by which the ratio of Aβ42 to Aβ40 can affect cell toxicity. An increased ratio of Aβ42 to Aβ40 raises the fraction of oligomers containing Aβ42, which can increase the hydrophobicity of the oligomers and thus promote deleterious binding to the cell membrane and increase neuronal damage. Our results suggest that co-oligomers are a common form of aggregate when Aβ isoforms are present in solution and may potentially play a significant role in Alzheimer’s disease.
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Affiliation(s)
- Marija Iljina
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Gonzalo A Garcia
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Alexander J Dear
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Jennie Flint
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Priyanka Narayan
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Thomas C T Michaels
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Christopher M Dobson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Daan Frenkel
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Tuomas P J Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
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31
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Janssen L, Keppens C, De Deyn PP, Van Dam D. Late age increase in soluble amyloid-beta levels in the APP23 mouse model despite steady-state levels of amyloid-beta-producing proteins. Biochim Biophys Acta Mol Basis Dis 2015; 1862:105-12. [PMID: 26542217 DOI: 10.1016/j.bbadis.2015.10.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 10/01/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
Affiliation(s)
- Leen Janssen
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Cleo Keppens
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Peter P De Deyn
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; Department of Neurology and Memory Clinic, Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Antwerp, Belgium; University of Groningen, University Medical Center Groningen (UMCG), Department of Neurology and Alzheimer Research Center, Groningen, The Netherlands; Biobank, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Debby Van Dam
- Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; University of Groningen, University Medical Center Groningen (UMCG), Department of Neurology and Alzheimer Research Center, Groningen, The Netherlands.
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Patterson BW, Elbert DL, Mawuenyega KG, Kasten T, Ovod V, Ma S, Xiong C, Chott R, Yarasheski K, Sigurdson W, Zhang L, Goate A, Benzinger T, Morris JC, Holtzman D, Bateman RJ. Age and amyloid effects on human central nervous system amyloid-beta kinetics. Ann Neurol 2015; 78:439-53. [PMID: 26040676 PMCID: PMC4546566 DOI: 10.1002/ana.24454] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 05/20/2015] [Accepted: 05/31/2015] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Age is the single greatest risk factor for Alzheimer's disease (AD), with the incidence doubling every 5 years after age 65. However, our understanding of the mechanistic relationship between increasing age and the risk for AD is currently limited. We therefore sought to determine the relationship between age, amyloidosis, and amyloid-beta (Aβ) kinetics in the central nervous system (CNS) of humans. METHODS Aβ kinetics were analyzed in 112 participants and compared to the ages of participants and the amount of amyloid deposition. RESULTS We found a highly significant correlation between increasing age and slowed Aβ turnover rates (2.5-fold longer half-life over five decades of age). In addition, we found independent effects on Aβ42 kinetics specifically in participants with amyloid deposition. Amyloidosis was associated with a higher (>50%) irreversible loss of soluble Aβ42 and a 10-fold higher Aβ42 reversible exchange rate. INTERPRETATION These findings reveal a mechanistic link between human aging and the risk of amyloidosis, which may be owing to a dramatic slowing of Aβ turnover, increasing the likelihood of protein misfolding that leads to deposition. Alterations in Aβ kinetics associated with aging and amyloidosis suggest opportunities for diagnostic and therapeutic strategies. More generally, this study provides an example of how changes in protein turnover kinetics can be used to detect physiological and pathophysiological changes and may be applicable to other proteinopathies.
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Affiliation(s)
- Bruce W Patterson
- Department of Medicine, Washington University in St. Louis, St. Louis, MO
| | - Donald L Elbert
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO
| | - Kwasi G Mawuenyega
- Department of Neurology, Washington University in St. Louis, St. Louis, MO
| | - Tom Kasten
- Department of Neurology, Washington University in St. Louis, St. Louis, MO
| | - Vitaliy Ovod
- Department of Neurology, Washington University in St. Louis, St. Louis, MO
| | - Shengmei Ma
- Department of Biostatistics, Washington University in St. Louis, St. Louis, MO
| | - Chengjie Xiong
- Department of Biostatistics, Washington University in St. Louis, St. Louis, MO
- Knight Alzheimer's Disease Research Center, Department of Neurology, Washington University in St. Louis, St. Louis, MO
| | - Robert Chott
- Department of Medicine, Washington University in St. Louis, St. Louis, MO
| | - Kevin Yarasheski
- Department of Medicine, Washington University in St. Louis, St. Louis, MO
| | - Wendy Sigurdson
- Department of Neurology, Washington University in St. Louis, St. Louis, MO
- Knight Alzheimer's Disease Research Center, Department of Neurology, Washington University in St. Louis, St. Louis, MO
| | - Lily Zhang
- Hope Center for Neurological Disorders, Department of Neurology, Washington University in St. Louis, St. Louis, MO
| | - Alison Goate
- Department of Psychiatry, Washington University in St. Louis, St. Louis, MO
- Hope Center for Neurological Disorders, Department of Neurology, Washington University in St. Louis, St. Louis, MO
| | - Tammie Benzinger
- Department of Radiology, Washington University in St. Louis, St. Louis, MO
- Knight Alzheimer's Disease Research Center, Department of Neurology, Washington University in St. Louis, St. Louis, MO
| | - John C Morris
- Department of Neurology, Washington University in St. Louis, St. Louis, MO
- Knight Alzheimer's Disease Research Center, Department of Neurology, Washington University in St. Louis, St. Louis, MO
| | - David Holtzman
- Department of Neurology, Washington University in St. Louis, St. Louis, MO
- Knight Alzheimer's Disease Research Center, Department of Neurology, Washington University in St. Louis, St. Louis, MO
- Hope Center for Neurological Disorders, Department of Neurology, Washington University in St. Louis, St. Louis, MO
| | - Randall J Bateman
- Department of Neurology, Washington University in St. Louis, St. Louis, MO
- Knight Alzheimer's Disease Research Center, Department of Neurology, Washington University in St. Louis, St. Louis, MO
- Hope Center for Neurological Disorders, Department of Neurology, Washington University in St. Louis, St. Louis, MO
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Barage SH, Sonawane KD. Amyloid cascade hypothesis: Pathogenesis and therapeutic strategies in Alzheimer's disease. Neuropeptides 2015; 52:1-18. [PMID: 26149638 DOI: 10.1016/j.npep.2015.06.008] [Citation(s) in RCA: 369] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 06/24/2015] [Accepted: 06/24/2015] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease is an irreversible, progressive neurodegenerative disorder. Various therapeutic approaches are being used to improve the cholinergic neurotransmission, but their role in AD pathogenesis is still unknown. Although, an increase in tau protein concentration in CSF has been described in AD, but several issues remains unclear. Extensive and accurate analysis of CSF could be helpful to define presence of tau proteins in physiological conditions, or released during the progression of neurodegenerative disease. The amyloid cascade hypothesis postulates that the neurodegeneration in AD caused by abnormal accumulation of amyloid beta (Aβ) plaques in various areas of the brain. The amyloid hypothesis has continued to gain support over the last two decades, particularly from genetic studies. Therefore, current research progress in several areas of therapies shall provide an effective treatment to cure this devastating disease. This review critically evaluates general biochemical and physiological functions of Aβ directed therapeutics and their relevance.
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Affiliation(s)
- Sagar H Barage
- Department of Biotechnology, Shivaji University, Kolhapur 416004, Maharashtra (M.S.), India
| | - Kailas D Sonawane
- Structural Bioinformatics Unit, Department of Biochemistry, Shivaji University, Kolhapur 416004, Maharashtra (M.S.), India; Department of Microbiology, Shivaji University, Kolhapur 416004, Maharashtra (M.S.), India.
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Li H, Guo Q, Inoue T, Polito VA, Tabuchi K, Hammer RE, Pautler RG, Taffet GE, Zheng H. Vascular and parenchymal amyloid pathology in an Alzheimer disease knock-in mouse model: interplay with cerebral blood flow. Mol Neurodegener 2014; 9:28. [PMID: 25108425 PMCID: PMC4132280 DOI: 10.1186/1750-1326-9-28] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 08/05/2014] [Indexed: 12/31/2022] Open
Abstract
Background Accumulation and deposition of β-amyloid peptides (Aβ) in the brain is a central event in the pathogenesis of Alzheimer’s disease (AD). Besides the parenchymal pathology, Aβ is known to undergo active transport across the blood–brain barrier and cerebral amyloid angiopathy (CAA) is a prominent feature in the majority of AD. Although impaired cerebral blood flow (CBF) has been implicated in faulty Aβ transport and clearance, and cerebral hypoperfusion can exist in the pre-clinical phase of Alzheimer’s disease (AD), it is still unclear whether it is one of the causal factors for AD pathogenesis, or an early consequence of a multi-factor condition that would lead to AD at late stage. To study the potential interaction between faulty CBF and amyloid accumulation in clinical-relevant situation, we generated a new amyloid precursor protein (APP) knock-in allele that expresses humanized Aβ and a Dutch mutation in addition to Swedish/London mutations and compared this line with an equivalent knock-in line but in the absence of the Dutch mutation, both crossed onto the PS1M146V knock-in background. Results Introduction of the Dutch mutation results in robust CAA and parenchymal Aβ pathology, age-dependent reduction of spatial learning and memory deficits, and CBF reduction as detected by fMRI. Direct manipulation of CBF by transverse aortic constriction surgery on the left common carotid artery caused differential changes in CBF in the anterior and middle region of the cortex, where it is reduced on the left side and increased on the right side. However these perturbations in CBF resulted in the same effect: both significantly exacerbate CAA and amyloid pathology. Conclusions Our study reveals a direct and positive link between vascular and parenchymal Aβ; both can be modulated by CBF. The new APP knock-in mouse model recapitulates many symptoms of AD including progressive vascular and parenchymal Aβ pathology and behavioral deficits in the absence of APP overexpression.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Hui Zheng
- Huffington Center on Aging, Baylor College of Medicine, Houston, Texas 77030, USA.
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35
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Hellström-Lindahl E, Westermark P, Antoni G, Estrada S. In vitro binding of [³H]PIB to human amyloid deposits of different types. Amyloid 2014; 21:21-7. [PMID: 24286359 DOI: 10.3109/13506129.2013.860895] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Systemic amyloidosis is caused by extracellular deposition of insoluble fibrillar proteins arranged in β-pleated sheets. [(11)C]PIB has been used in PET studies to assess Aβ deposition in brain of patients with Alzheimer's disease (AD). The possibility to visualize other types of amyloid deposits with [(11)C]PIB would be of potential clinical importance in early diagnosis and for following therapeutic effects. In the present study, we evaluated in vitro binding of [(3)H]PIB to tissues containing transthyretin (ATTR), immunoglobulin light-chain (AL), amyloid protein A (AA) and Aβ amyloid. We found significantly higher binding of [(3)H]PIB in tissue from systemic amyloidoses than in control tissue, i.e. 4.7 times higher (p < 0.05). [(3)H]PIB showed the highest affinity to cortex of AD brain (IC50 = 3.84 nM), while IC50 values were much higher for ATTR, AA and AL type of amyloidosis and large variations in affinity were observed even within tissues having the same type of amyloidosis. Extraction with guanidine-HCl, which disrupts the β-sheet structure, decreased the protein levels and, concomitantly, the binding of [(3)H]PIB in all four types of amyloidoses.
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Mitochondrial dysfunction: cause and consequence of Alzheimer's disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 127:183-210. [PMID: 25149218 DOI: 10.1016/b978-0-12-394625-6.00007-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The etiology of common, nonfamiliar late-onset Alzheimer's disease (LOAD) is only partly understood and seems to be extremely complex including many genetic and environmental factors. The most important environmental risk factor to develop LOAD is aging itself. Aging and LOAD are considered to be strongly linked to mitochondrial dysfunction and enhanced oxidative stress. In this review, we focus on the interaction between mitochondrial dysfunction in aging especially on defects of the respiratory chain of the oxidative phosphorylation system resulting in enhanced oxidative stress and the interplay between aging-associated mitochondrial defects and LOAD-associated mitochondrial failure. The deleterious effects of the two hallmarks of LOAD, amyloid beta, and hyperphosphorylated tau, on mitochondrial function, movement, and morphology are described as well as the toxic effects of the most relevant genetic risk factor of LOAD, the apolipoprotein E4 allele. Finally, the review provides an overview about drugs and nutritional ingredients which improve mitochondrial function or/and act as antioxidants and discusses their potential role in the treatment of LOAD.
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Isorhynchophylline Protects PC12 Cells Against Beta-Amyloid-Induced Apoptosis via PI3K/Akt Signaling Pathway. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:163057. [PMID: 24319473 PMCID: PMC3836301 DOI: 10.1155/2013/163057] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 09/12/2013] [Accepted: 09/23/2013] [Indexed: 11/18/2022]
Abstract
The neurotoxicity of amyloid- β (A β ) has been implicated as a critical cause of Alzheimer's disease. Isorhynchophylline (IRN), an oxindole alkaloid isolated from Uncaria rhynchophylla, exerts neuroprotective effect against Aβ 25-35-induced neurotoxicity in vitro. However, the exact mechanism for its neuroprotective effect is not well understood. The present study aimed to investigate the molecular mechanisms underlying the protective action of IRN against Aβ 25-35-induced neurotoxicity in cultured rat pheochromocytoma (PC12) cells. Pretreatment with IRN significantly increased the cell viability, inhibited the release of lactate dehydrogenase and the extent of DNA fragmentation in Aβ 25-35-treated cells. IRN treatment was able to enhance the protein levels of phosphorylated Akt (p-Akt) and glycogen synthase kinase-3 β (p-GSK-3 β ). Lithium chloride blocked Aβ 25-35-induced cellular apoptosis in a similar manner as IRN, suggesting that GSK-3 β inhibition was involved in neuroprotective action of IRN. Pretreatment with LY294002 completely abolished the protective effects of IRN. Furthermore, IRN reversed Aβ 25-35-induced attenuation in the level of phosphorylated cyclic AMP response element binding protein (p-CREB) and the effect of IRN could be blocked by the PI3K inhibitor. These experimental findings unambiguously suggested that the protective effect of IRN against Aβ 25-35-induced apoptosis in PC12 cells was associated with the enhancement of p-CREB expression via PI3K/Akt/GSK-3 β signaling pathway.
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Couch BA, Kerrisk ME, Kaufman AC, Nygaard HB, Strittmatter SM, Koleske AJ. Delayed amyloid plaque deposition and behavioral deficits in outcrossed AβPP/PS1 mice. J Comp Neurol 2013; 521:1395-408. [PMID: 23047754 DOI: 10.1002/cne.23239] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 05/22/2012] [Accepted: 10/02/2012] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative dementia characterized by amyloid plaque accumulation, synapse/dendrite loss, and cognitive impairment. Transgenic mice expressing mutant forms of amyloid-β precursor protein (AβPP) and presenilin-1 (PS1) recapitulate several aspects of this disease and provide a useful model system for studying elements of AD progression. AβPP/PS1 mice have been previously shown to exhibit behavioral deficits and amyloid plaque deposition between 4-9 months of age. We crossed AβPP/PS1 animals with mice of a mixed genetic background (C57BL/6 × 129/SvJ) and investigated the development of AD-like features in the resulting outcrossed mice. The onset of memory-based behavioral impairment is delayed considerably in outcrossed AβPP/PS1 mice relative to inbred mice on a C57BL/6 background. While inbred AβPP/PS1 mice develop deficits in radial-arm water maze performance and novel object recognition as early as 8 months, outcrossed AβPP/PS1 mice do not display defects until 18 months. Within the forebrain, we find that inbred AβPP/PS1 mice have significantly higher amyloid plaque burden at 12 months than outcrossed AβPP/PS1 mice of the same age. Surprisingly, inbred AβPP/PS1 mice at 8 months have low plaque burden, suggesting that plaque burden alone cannot explain the accompanying behavioral deficits. Analysis of AβPP processing revealed that elevated levels of soluble Aβ correlate with the degree of behavioral impairment in both strains. Taken together, these findings suggest that animal behavior, amyloid plaque deposition, and AβPP processing are sensitive to genetic differences between mouse strains.
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Affiliation(s)
- Brian A Couch
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
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Acetyl-CoA the key factor for survival or death of cholinergic neurons in course of neurodegenerative diseases. Neurochem Res 2013; 38:1523-42. [PMID: 23677775 PMCID: PMC3691476 DOI: 10.1007/s11064-013-1060-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 04/19/2013] [Accepted: 04/22/2013] [Indexed: 12/24/2022]
Abstract
Glucose-derived pyruvate is a principal source of acetyl-CoA in all brain cells, through pyruvate dehydogenase complex (PDHC) reaction. Cholinergic neurons like neurons of other transmitter systems and glial cells, utilize acetyl-CoA for energy production in mitochondria and diverse synthetic pathways in their extramitochondrial compartments. However, cholinergic neurons require additional amounts of acetyl-CoA for acetylcholine synthesis in their cytoplasmic compartment to maintain their transmitter functions. Characteristic feature of several neurodegenerating diseases including Alzheimer’s disease and thiamine diphosphate deficiency encephalopathy is the decrease of PDHC activity correlating with cholinergic deficits and losses of cognitive functions. Such conditions generate acetyl-CoA deficits that are deeper in cholinergic neurons than in noncholinergic neuronal and glial cells, due to its additional consumption in the transmitter synthesis. Therefore, any neuropathologic conditions are likely to be more harmful for the cholinergic neurons than for noncholinergic ones. For this reason attempts preserving proper supply of acetyl-CoA in the diseased brain, should attenuate high susceptibility of cholinergic neurons to diverse neurodegenerative conditions. This review describes how common neurodegenerative signals could induce deficts in cholinergic neurotransmission through suppression of acetyl-CoA metabolism in the cholinergic neurons.
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APP mutations in the Aβ coding region are associated with abundant cerebral deposition of Aβ38. Acta Neuropathol 2012; 124:809-21. [PMID: 23143229 DOI: 10.1007/s00401-012-1061-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 10/24/2012] [Accepted: 10/26/2012] [Indexed: 12/19/2022]
Abstract
Aβ is the main component of amyloid deposits in Alzheimer disease (AD) and its aggregation into oligomers, protofibrils and fibrils is considered a seminal event in the pathogenesis of AD. Aβ with C-terminus at residue 42 is the most abundant species in parenchymal deposits, whereas Aβ with C-terminus at residue 40 predominates in the amyloid of the walls of large vessels. Aβ peptides with other C-termini have not yet been thoroughly investigated. We analysed Aβ38 in the brains of patients with Aβ deposition linked to sporadic and familial AD, hereditary cerebral haemorrhage with amyloidosis, or Down syndrome. Immunohistochemistry, confocal microscopy, immunoelectron microscopy, immunoprecipitation and the electrophoresis separation of low molecular weight aggregates revealed that Aβ38 accumulates consistently in the brains of patients carrying APP mutations in the Aβ coding region, but was not detected in the patients with APP mutations outside the Aβ domain, in the patients with presenilin mutations or in subjects with Down syndrome. In the patients with sporadic AD, Aβ38 was absent in the senile plaques, but it was detected only in the vessel walls of a small subset of patients with severe cerebral amyloid angiopathy. Our results suggest that APP mutations in the Aβ coding region favour Aβ38 accumulation in the brain and that the molecular mechanisms of Aβ deposition in these patients may be different from those active in patients with familial AD associated with other genetic defects and sporadic AD.
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Pauwels K, Williams TL, Morris KL, Jonckheere W, Vandersteen A, Kelly G, Schymkowitz J, Rousseau F, Pastore A, Serpell LC, Broersen K. Structural basis for increased toxicity of pathological aβ42:aβ40 ratios in Alzheimer disease. J Biol Chem 2011; 287:5650-60. [PMID: 22157754 DOI: 10.1074/jbc.m111.264473] [Citation(s) in RCA: 195] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The β-amyloid peptide (Aβ) is directly related to neurotoxicity in Alzheimer disease (AD). The two most abundant alloforms of the peptide co-exist under normal physiological conditions in the brain in an Aβ(42):Aβ(40) ratio of ∼1:9. This ratio is often shifted to a higher percentage of Aβ(42) in brains of patients with familial AD and this has recently been shown to lead to increased synaptotoxicity. The molecular basis for this phenomenon is unclear. Although the aggregation characteristics of Aβ(40) and Aβ(42) individually are well established, little is known about the properties of mixtures. We have explored the biophysical and structural properties of physiologically relevant Aβ(42):Aβ(40) ratios by several techniques. We show that Aβ(40) and Aβ(42) directly interact as well as modify the behavior of the other. The structures of monomeric and fibrillar assemblies formed from Aβ(40) and Aβ(42) mixtures do not differ from those formed from either of these peptides alone. Instead, the co-assembly of Aβ(40) and Aβ(42) influences the aggregation kinetics by altering the pattern of oligomer formation as evidenced by a unique combination of solution nuclear magnetic resonance spectroscopy, high molecular weight mass spectrometry, and cross-seeding experiments. We relate these observations to the observed enhanced toxicity of relevant ratios of Aβ(42):Aβ(40) in synaptotoxicity assays and in AD patients.
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Affiliation(s)
- Kris Pauwels
- Division of Molecular Structure, Medical Research Council National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
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Neniskyte U, Neher JJ, Brown GC. Neuronal death induced by nanomolar amyloid β is mediated by primary phagocytosis of neurons by microglia. J Biol Chem 2011; 286:39904-13. [PMID: 21903584 PMCID: PMC3220594 DOI: 10.1074/jbc.m111.267583] [Citation(s) in RCA: 159] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Alzheimer disease is characterized by neuronal loss and brain plaques of extracellular amyloid β (Aβ), but the means by which Aβ may induce neuronal loss is not entirely clear. Although high concentrations of Aβ (μm) can induce direct toxicity to neurons, we find that low concentration (nm) induce neuronal loss through a microglia-mediated mechanism. In mixed neuronal-glial cultures from rat cerebellum, 250 nm Aβ1–42 (added as monomers, oligomers or fibers) induced about 30% loss of neurons between 2 and 3 days. This neuronal loss occurred without any increase in neuronal apoptosis or necrosis, and no neuronal loss occurred with Aβ42–1. Aβ greatly increased the phagocytic capacity of microglia and induced phosphatidylserine exposure (an “eat-me” signal) on neuronal processes. Blocking exposed phosphatidylserine by adding annexin V or an antibody to phosphatidylserine or inhibiting microglial phagocytosis by adding either cytochalasin D (to block actin polymerization) or cyclo(RGDfV) (to block vitronectin receptors) significantly prevented neuronal loss. Loss of neuronal synapses occurred in parallel with loss of cell bodies and was also prevented by blocking phagocytosis. Inhibition of phagocytosis prevented neuronal loss with no increase in neuronal death, even after 7 days, suggesting that microglial phagocytosis was the primary cause of neuronal death induced by nanomolar Aβ.
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Affiliation(s)
- Urte Neniskyte
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom.
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The amyloid cascade hypothesis for Alzheimer's disease: an appraisal for the development of therapeutics. Nat Rev Drug Discov 2011; 10:698-712. [DOI: 10.1038/nrd3505] [Citation(s) in RCA: 1485] [Impact Index Per Article: 114.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Castellani RJ, Smith MA. Compounding artefacts with uncertainty, and an amyloid cascade hypothesis that is 'too big to fail'. J Pathol 2011; 224:147-52. [PMID: 21557219 DOI: 10.1002/path.2885] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
With each failure of anti-amyloid-β therapy in clinical trials, new trials are initiated with no hint of slowing down. This may be due, in part, to the fact that the amyloid cascade hypothesis has been so modified over time that it is now impossible to confirm or deny. The hypothesis now states, in effect, that invisible molecules target invisible structures. Still relevant, however, are multiple factors that surely cast some doubt but have either been rationalized or overlooked. Among these are the poor correlation between amyloid-β deposits and disease, the substantial differences between familial and sporadic disease, pathological assessment that indicates the secondary nature of lesions/proteins/cascades, the fact that soluble species are poorly reproducible laboratory phenomena, and the irrelevance of synaptic assessment to pathological interpretation. Although not yet dogma, the premature addition of mild cognitive impairment as the implied in vivo homologue to the soluble toxin-synapse interaction is also problematic. In either case, the amyloid cascade hypothesis continues to dominate the Alzheimer's disease literature and grant applications. The more the neuroscience community perseverates along these lines in the face of accumulating outcome data to the contrary, the more one is left to wonder whether the hypothesis is too big to fail.
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Affiliation(s)
- Rudy J Castellani
- Department of Pathology, University of Maryland, Baltimore, MD, USA.
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Shafaati M, Marutle A, Pettersson H, Lövgren-Sandblom A, Olin M, Pikuleva I, Winblad B, Nordberg A, Björkhem I. Marked accumulation of 27-hydroxycholesterol in the brains of Alzheimer's patients with the Swedish APP 670/671 mutation. J Lipid Res 2011; 52:1004-10. [PMID: 21335619 DOI: 10.1194/jlr.m014548] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
There is a significant flux of the neurotoxic oxysterol 27-hydroxycholesterol (27OHC) from the circulation across the blood-brain barrier. Because there is a correlation between 27OHC and cholesterol in the circulation and lipoprotein-bound cholesterol does not pass the blood-brain barrier, we have suggested that 27OHC may mediate the effects of hypercholesterolemia on the brain. We previously demonstrated a modest accumulation of 27OHC in brains of patients with sporadic Alzheimer's disease (AD), consistent with a role of 27OHC as a primary pathogenetic factor. We show here that there is a 4-fold accumulation of 27OHC in different regions of the cortexes of patients carrying the Swedish amyloid precursor protein (APPswe) 670/671 mutation. The brain levels of sitosterol and campesterol were not significantly different in the AD patients compared with the controls, suggesting that the blood-brain barrier was intact in the AD patients. We conclude that accumulation of 27OHC is likely to be secondary to neurodegeneration, possibly a result of reduced activity of CYP7B1, the neuronal enzyme responsible for metabolism of 27OHC. We discuss the possibility of a vicious circle in the brains of the patients with familial AD whereby neurodegenerative changes cause an accumulation of 27OHC that further accelerates neurodegeneration.
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Affiliation(s)
- Marjan Shafaati
- Department of Laboratory Medicine Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital Huddinge, Huddinge, Sweden
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Strandberg TE, Sipilä S. Biogerontology in Finland. Biogerontology 2010; 12:71-5. [PMID: 21161378 DOI: 10.1007/s10522-010-9313-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Accepted: 11/29/2010] [Indexed: 12/01/2022]
Abstract
This paper describes current biogerontology research in Finland especially in the universities with professorships in gerontology/geriatrics. If biogerontology is broadly taken to include all research in basic mechanisms of normal ageing as well as age-related diseases, the most prevalent current topics include basic research in genetics, mitochondrial function, musculoskeletal physiology, neurodegenerative and vascular diseases. The research activity of each institute and their international collaboration is briefly described with examples focused on recent publications in the field of biogerontology.
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Affiliation(s)
- Timo E Strandberg
- Institute of Health Sciences/Geriatrics, Oulu University Hospital, University of Oulu, Oulu, Finland.
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Ash ES, Alavijeh MS, Palmer AM, Mitchelmore C, Howlett DR, Francis PT, Broadstock M, Richardson JC. Neurochemical changes in a double transgenic mouse model of Alzheimer's disease fed a pro-oxidant diet. Neurochem Int 2010; 57:504-11. [PMID: 20600435 DOI: 10.1016/j.neuint.2010.06.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 06/23/2010] [Accepted: 06/24/2010] [Indexed: 01/18/2023]
Abstract
Oxidative stress is implicated in the pathogenesis of Alzheimer's disease (AD) causing neurodegeneration and decreased monoamine neurotransmitters. We investigated the effect of administration of a pro-oxidant diet on the levels of monoamines and metabolites in the brains of wildtype and transgenic mice expressing mutant APP and PS-1 (TASTPM mice). Three-month-old TASTPM and wildtype (C57BL6/J) mice were fed either normal or pro-oxidant diet for 3 months. The neocortex, cerebellum, hippocampus and striatum were assayed for their monoamine and monoamine metabolite content using HPLC with electrochemical detection. Striatal tyrosine hydroxylase (TOH) levels were analysed by Western blotting. In the striatum, female TASTPM mice had higher levels of DOPAC and male TASTPM mice had higher levels of 5-HIAA compared to wildtype mice. Administration of pro-oxidant diet increased striatal MHPG, turnover of NA and 5-HT levels in female TASTPM mice compared to TASTPM mice fed control diet. The pro-oxidant diet also decreased DOPAC levels in female TASTPM mice compared to those fed control diet. Striatal TOH did not depend on diet, gender or genotype. In the neocortex, the TASTPM genotype increased levels of 5-HIAA in male mice fed control diet compared to wildtype mice. In the cerebellum, the TASTPM genotype led to decreased levels of HVA (male mice only) and also decreased turnover of DA (female mice only) compared to wildtype mice. These data suggest a sparing of monoaminergic neurones in the cortex, striatum and hippocampus of TASTPM mice fed pro-oxidant diet and could be indicative of increased activity in corticostriatal circuits. The decreased cerebellar levels of HVA and turnover of DA in TASTPM mice hint at possible axonal degeneration within this subregion.
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Abstract
The complex neurodegeneration underlying Alzheimer disease (AD), although incompletely understood, is characterised by an aberrant re-entry into the cell cycle in neurons. Pathological evidence, in the form of cell cycle markers and regulatory proteins, suggests that cell cycle re-entry is an early event in AD, which precedes the formation of amyloid-beta plaques and neurofibrillary tangles (NFTs). Although the exact mechanisms that induce and mediate these cell cycle events in AD are not clear, significant advances have been made in further understanding the pathological role of cell cycle re-entry in AD. Importantly, recent studies indicate that cell cycle re-entry is not a consequence, but rather a cause, of neurodegeneration, suggesting that targeting of cell cycle re-entry may provide an opportunity for therapeutic intervention. Moreover, multiple inducers of cell cycle re-entry and their interactions in AD have been proposed. Here, we review the most recent advances in understanding the pathological implications of cell cycle re-entry in AD.
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Ionov ID, Pushinskaya II. Amyloid-beta production in aged guinea pigs: atropine-induced enhancement is reversed by naloxone. Neurosci Lett 2010; 480:83-6. [PMID: 20540990 DOI: 10.1016/j.neulet.2010.06.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 05/15/2010] [Accepted: 06/02/2010] [Indexed: 11/29/2022]
Abstract
Advanced age, cholinergic deficit, and elevated brain levels of enkephalin are associated with sporadic Alzheimer's disease. The influence of these factors on production of amyloidogenic peptides (Abeta) is uncertain. In the present experiments, the levels of 40/42 amino acid-residue Abeta were measured in the brain cortex of guinea pigs aged 15-16 weeks (young) and 25-26 months (aged). As was found, injections of atropine (21 days, 5mg/kg/day) increase Abeta levels in aged but not young animals. This atropine-induced effect was antagonized by simultaneous injections of naloxone (3mg/kg/day) whereas naloxone alone failed to affect Abeta accumulation. These results are discussed in the light of a possible "acetylcholine - Abeta" feedback loop and an influence of enkephalin on the loop function.
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Affiliation(s)
- Ilya D Ionov
- Centre on Theoretical Problems in Physical and Chemical Pharmacology, Russian Academy of Sciences, Leninsky Prospect 123-4-63, Moscow 117513, Russia.
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