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Saha J, Ford BJ, Wang X, Boyd S, Morgan SE, Rangachari V. Sugar distributions on gangliosides guide the formation and stability of amyloid-β oligomers. Biophys Chem 2023; 300:107073. [PMID: 37413816 PMCID: PMC10529042 DOI: 10.1016/j.bpc.2023.107073] [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: 03/24/2023] [Revised: 06/25/2023] [Accepted: 06/27/2023] [Indexed: 07/08/2023]
Abstract
Aggregation of Aβ peptides is a key contributor to the etiology of Alzheimer's disease. Being intrinsically disordered, monomeric Aβ is susceptible to conformational excursions, especially in the presence of important interacting partners such as membrane lipids, to adopt specific aggregation pathways. Furthermore, components such as gangliosides in membranes and lipid rafts are known to play important roles in the adoption of pathways and the generation of discrete neurotoxic oligomers. Yet, what roles do carbohydrates on gangliosides play in this process remains unknown. Here, using GM1, GM3, and GD3 ganglioside micelles as models, we show that the sugar distributions and cationic amino acids within Aβ N-terminal region modulate oligomerization of Aβ temporally, and dictate the stability and maturation of oligomers. These results demonstrate the selectivity of sugar distributions on the membrane surface toward oligomerization of Aβ and thus implicate cell-selective enrichment of oligomers.
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Affiliation(s)
- Jhinuk Saha
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, 118, College Dr Hattiesburg, MS 39402, USA
| | - Brea J Ford
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, 118, College Dr Hattiesburg, MS 39402, USA
| | | | - Sydney Boyd
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, 118, College Dr Hattiesburg, MS 39402, USA
| | | | - Vijayaraghavan Rangachari
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, 118, College Dr Hattiesburg, MS 39402, USA; Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA.
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2
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Saha J, Ford BJ, Boyd S, Rangachari V. Sugar distributions on gangliosides guide the formation and stability of amyloid-β oligomers. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.09.540003. [PMID: 37214891 PMCID: PMC10197704 DOI: 10.1101/2023.05.09.540003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Aggregation of Aβ peptides has been known as a key contributor to the etiology of Alzheimer's disease. Being intrinsically disordered, the monomeric Aβ is susceptible to conformational excursions, especially in the presence of key interacting partners such as membrane lipids, to adopt specific aggregation pathways. Furthermore, key components such as gangliosides in membranes and lipid rafts are known to play important roles in the adoption of pathways and the generation of discrete neurotoxic oligomers. Yet, what roles the carbohydrates on gangliosides play in this process remains unknown. Here, using GM1, GM3, and GD3 ganglioside micelles as models, we show that the sugar distributions and cationic amino acids within Aβ N-terminal region modulate oligomerization of Aβ temporally, and dictate the stability and maturation of oligomers.
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3
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Varshavskaya KB, Mitkevich VA, Makarov AA, Barykin EP. Synthetic, Cell-Derived, Brain-Derived, and Recombinant β-Amyloid: Modelling Alzheimer's Disease for Research and Drug Development. Int J Mol Sci 2022; 23:ijms232315036. [PMID: 36499362 PMCID: PMC9738609 DOI: 10.3390/ijms232315036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 12/02/2022] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia in the elderly, characterised by the accumulation of senile plaques and tau tangles, neurodegeneration, and neuroinflammation in the brain. The development of AD is a pathological cascade starting according to the amyloid hypothesis with the accumulation and aggregation of the β-amyloid peptide (Aβ), which induces hyperphosphorylation of tau and promotes the pro-inflammatory activation of microglia leading to synaptic loss and, ultimately, neuronal death. Modelling AD-related processes is important for both studying the molecular basis of the disease and the development of novel therapeutics. The replication of these processes is often achieved with the use of a purified Aβ peptide. However, Aβ preparations obtained from different sources can have strikingly different properties. This review aims to compare the structure and biological effects of Aβ oligomers and aggregates of a higher order: synthetic, recombinant, purified from cell culture, or extracted from brain tissue. The authors summarise the applicability of Aβ preparations for modelling Aβ aggregation, neurotoxicity, cytoskeleton damage, receptor toxicity in vitro and cerebral amyloidosis, synaptic plasticity disruption, and cognitive impairment in vivo and ex vivo. Further, the paper discusses the causes of the reported differences in the effect of Aβ obtained from the sources mentioned above. This review points to the importance of the source of Aβ for AD modelling and could help researchers to choose the optimal way to model the Aβ-induced abnormalities.
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Bigi A, Cascella R, Chiti F, Cecchi C. Amyloid fibrils act as a reservoir of soluble oligomers, the main culprits in protein deposition diseases. Bioessays 2022; 44:e2200086. [DOI: 10.1002/bies.202200086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 08/25/2021] [Accepted: 08/30/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Alessandra Bigi
- Department of Experimental and Clinical Biomedical Sciences Section of Biochemistry University of Florence Florence Italy
| | - Roberta Cascella
- Department of Experimental and Clinical Biomedical Sciences Section of Biochemistry University of Florence Florence Italy
| | - Fabrizio Chiti
- Department of Experimental and Clinical Biomedical Sciences Section of Biochemistry University of Florence Florence Italy
| | - Cristina Cecchi
- Department of Experimental and Clinical Biomedical Sciences Section of Biochemistry University of Florence Florence Italy
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Luo JJ, Wallace W, Kusiak JW. A tough trek in the development of an anti-amyloid therapy for Alzheimer's disease: Do we see hope in the distance? J Neurol Sci 2022; 438:120294. [DOI: 10.1016/j.jns.2022.120294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/27/2022] [Accepted: 05/18/2022] [Indexed: 12/17/2022]
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Krafft GA, Jerecic J, Siemers E, Cline EN. ACU193: An Immunotherapeutic Poised to Test the Amyloid β Oligomer Hypothesis of Alzheimer’s Disease. Front Neurosci 2022; 16:848215. [PMID: 35557606 PMCID: PMC9088393 DOI: 10.3389/fnins.2022.848215] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/02/2022] [Indexed: 12/26/2022] Open
Abstract
Alzheimer’s disease (AD) is an age-related neurodegenerative disease that affects 50 million people worldwide, with 10 million new cases occurring each year. The emotional and economic impacts of AD on patients and families are devastating. Approved treatments confer modest improvement in symptoms, and recently one treatment obtained accelerated approval from the United States Food and Drug Administration (FDA) and may have modest disease modifying benefit. Research over the past three decades has established a clear causal linkage between AD and elevated brain levels of amyloid β (Aβ) peptide, and substantial evidence now implicates soluble, non-fibrillar Aβ oligomers (AβOs) as the molecular assemblies directly responsible for AD-associated memory and cognitive failure and accompanying progressive neurodegeneration. The widely recognized linkage of elevated Aβ and AD spawned a comprehensive 20-year therapeutic campaign that focused primarily on two strategies – inhibition of the secretase enzymes responsible for Aβ production and clearance of Aβ peptide or amyloid plaques with Aβ-directed immunotherapeutics. Unfortunately, all clinical trials of secretase inhibitors were unsuccessful. Of the completed phase 3 immunotherapy programs, bapineuzumab (targeting amyloid plaque) and solanezumab (targeting Aβ monomers) were negative, and the crenezumab program (targeting Aβ monomers and to a small extent oligomers) was stopped for futility. Aducanumab (targeting amyloid plaques), which recently received FDA accelerated approval, had one positive and one negative phase 3 trial. More than 25 negative randomized clinical trials (RCTs) have evaluated Aβ-targeting therapeutics, yet none has directly evaluated whether selective blockage of disease-relevant AβOs can stop or reverse AD-associated cognitive decline. Here, we briefly summarize studies that establish the AD therapeutic rationale to target AβOs selectively, and we describe ACU193, the first AβO-selective immunotherapeutic to enter human clinical trials and the first positioned to test the AβO hypothesis of AD.
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Zarini-Gakiye E, Amini J, Sanadgol N, Vaezi G, Parivar K. Recent Updates in the Alzheimer's Disease Etiopathology and Possible Treatment Approaches: A Narrative Review of Current Clinical Trials. Curr Mol Pharmacol 2021; 13:273-294. [PMID: 32321414 DOI: 10.2174/1874467213666200422090135] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 02/19/2020] [Accepted: 03/04/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) is the most frequent subtype of incurable neurodegenerative dementias and its etiopathology is still not clearly elucidated. OBJECTIVE Outline the ongoing clinical trials (CTs) in the field of AD, in order to find novel master regulators. METHODS We strictly reviewed all scientific reports from Clinicaltrials.gov and PubMed databases from January 2010 to January 2019. The search terms were "Alzheimer's disease" or "dementia" and "medicine" or "drug" or "treatment" and "clinical trials" and "interventions". Manuscripts that met the objective of this study were included for further evaluations. RESULTS Drug candidates have been categorized into two main groups including antibodies, peptides or hormones (such as Ponezumab, Interferon β-1a, Solanezumab, Filgrastim, Levemir, Apidra, and Estrogen), and naturally-derived ingredients or small molecules (such as Paracetamol, Ginkgo, Escitalopram, Simvastatin, Cilostazo, and Ritalin-SR). The majority of natural candidates acted as anti-inflammatory or/and anti-oxidant and antibodies exert their actions via increasing amyloid-beta (Aβ) clearance or decreasing Tau aggregation. Among small molecules, most of them that are present in the last phases act as specific antagonists (Suvorexant, Idalopirdine, Intepirdine, Trazodone, Carvedilol, and Risperidone) or agonists (Dextromethorphan, Resveratrol, Brexpiprazole) and frequently ameliorate cognitive dysfunctions. CONCLUSION The presences of a small number of candidates in the last phase suggest that a large number of candidates have had an undesirable side effect or were unable to pass essential eligibility for future phases. Among successful treatment approaches, clearance of Aβ, recovery of cognitive deficits, and control of acute neuroinflammation are widely chosen. It is predicted that some FDA-approved drugs, such as Paracetamol, Risperidone, Escitalopram, Simvastatin, Cilostazoand, and Ritalin-SR, could also be used in off-label ways for AD. This review improves our ability to recognize novel treatments for AD and suggests approaches for the clinical trial design for this devastating disease in the near future.
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Affiliation(s)
- Elahe Zarini-Gakiye
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Javad Amini
- Department of Biology, Faculty of Sciences, University of Zabol, Zabol, Iran
| | - Nima Sanadgol
- Department of Biology, Faculty of Sciences, University of Zabol, Zabol, Iran,Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Gholamhassan Vaezi
- Department of Biology, Damghan Branch, Islamic Azad University, Damghan, Iran
| | - Kazem Parivar
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
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Mukhopadhyay S, Banerjee D. A Primer on the Evolution of Aducanumab: The First Antibody Approved for Treatment of Alzheimer's Disease. J Alzheimers Dis 2021; 83:1537-1552. [PMID: 34366359 DOI: 10.3233/jad-215065] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia with global burden projected to triple by 2050. It incurs significant biopsychosocial burden worldwide with limited treatment options. Aducanumab is the first monoclonal antibody recently approved by the US-FDA for mild AD through the accelerated approval pathway. It is the first molecule to be approved for AD since 2003 and carries with it a therapeutic promise for the future. As the definition of AD has evolved from a pathological entity to a Clinico-biological construct over the years, the amyloid-β (Aβ) pathway has been increasingly implicated in its pathogenesis. The approval of Aducanumab is based on reduction of the Aβ load in the brain, which forms a surrogate marker for this pathway. The research populace has, however, been globally divided by skepticism and hope regarding this approval. Failure to meet clinical endpoints in the trials, alleged transparency issues, cost-effectiveness, potential adverse effects, need for regular monitoring, and critique of 'amyloid cascade hypothesis' itself are the main caveats concerning the antibody. With this controversy in background, this paper critically looks at antibody research in AD therapeutics, evidence, and evolution of Aducanumab as a drug and the potential clinical implications of its use in future. While the efficacy of this monoclonal antibody in AD stands as a test of time, based on the growing evidence it is vital to rethink and explore alternate pathways of pathogenesis (oxidative stress, neuroinflammation, cholesterol metabolism, vascular factors, etc.) as possible therapeutic targets that may help elucidate the enigma of this complex yet progressive and debilitating neurodegenerative disorder.
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Affiliation(s)
- Sanchari Mukhopadhyay
- Geriatric Unit, Department of Psychiatry, NationalInstitute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
| | - Debanjan Banerjee
- Geriatric Unit, Department of Psychiatry, NationalInstitute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
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Hu KW, Fan HF, Lin HC, Huang JW, Chen YC, Shen CL, Shih YH, Tu LH. Exploring the Impact of Glyoxal Glycation on β-Amyloid Peptide (Aβ) Aggregation in Alzheimer's Disease. J Phys Chem B 2021; 125:5559-5571. [PMID: 34019761 DOI: 10.1021/acs.jpcb.1c02797] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease (AD) is characterized by the presence of extracellular senile plaques formed by β-amyloid (Aβ) peptides in the patient's brain. Previous studies have shown that the plaques in the AD brains are colocalized with the advanced glycation end products, which is mainly formed from a series of nonenzymatic reactions of proteins with reducing sugars or reactive dicarbonyls. Glycation was also demonstrated to increase the neurotoxicity of the Aβ peptides. To clarify the impact of glycation on Aβ aggregation, we synthesized two glycated Aβ42 peptides by replacing Lys16 and Lys28 with Nε-carboxymethyllysine respectively to mimic the occurrence of protein glycation. Afterward, we monitored the aggregation kinetics and conformational change for two glycated peptides. We also used fluorescence correlation spectroscopy to probe the early stage of peptide oligomerization and tested their abilities in copper binding and reactive oxygen species production. Our data show that glycation significantly slows down the aggregation process and induces more cytotoxicity especially at position 28. We speculated that the higher toxicity might result from a relatively stable oligomeric form of peptide and not from ROS production. The data shown here emphasized that glycated proteins would be an important therapeutic target in AD treatments.
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Affiliation(s)
- Kai-Wei Hu
- Department of Chemistry, National Taiwan Normal University, Taipei 100, Taiwan
| | - Hsiu-Fang Fan
- Institute of Medical Science and Technology, National Sun Yat-Sen University, Kaohsiung 800, Taiwan
| | - Han-Chen Lin
- Department of Anatomy, School of Medicine, Kaohsiung Medical University, Kaohsiung 800, Taiwan
| | - Jian-Wei Huang
- Institute of Medical Science and Technology, National Sun Yat-Sen University, Kaohsiung 800, Taiwan
| | - Yu-Chieh Chen
- Department of Chemistry, National Taiwan Normal University, Taipei 100, Taiwan
| | - Cai-Ling Shen
- Department of Chemistry, National Taiwan Normal University, Taipei 100, Taiwan
| | - Yao-Hsiang Shih
- Department of Anatomy, School of Medicine, Kaohsiung Medical University, Kaohsiung 800, Taiwan
| | - Ling-Hsien Tu
- Department of Chemistry, National Taiwan Normal University, Taipei 100, Taiwan
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10
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Pyun JM, Kang MJ, Ryoo N, Suh J, Youn YC, Park YH, Kim S. Amyloid Metabolism and Amyloid-Targeting Blood-Based Biomarkers of Alzheimer's Disease. J Alzheimers Dis 2021; 75:685-696. [PMID: 32390633 DOI: 10.3233/jad-200104] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Amyloid-β (Aβ) is a key protein in Alzheimer's disease (AD) in that its accumulation induces complex pathological changes. Although there has been extensive research on the metabolism of Aβ in AD, new compelling results have recently emerged. Historically, the production and clearance of Aβ have been thought to originate in the central nervous system (CNS). However, recent evidence suggests that the production and clearance of Aβ can also occur in the peripheral system, and that the peripherally driven Aβ migrates to the CNS and induces amyloidopathy with subsequent AD pathologic changes in the brain. This concept implies that AD is not restricted to the CNS but is a systemic disease instead. As such, the development of blood-based biomarkers targeting Aβ is of great interest. Central and peripheral Aβ are both active contributors to the pathology of AD and interact bidirectionally. Measuring peripheral Aβ is not just observing the reflection of the residual Aβ removed from the CNS but also tracking the ongoing process of AD pathology. Additionally, blood-based biomarkers could be a more accessible tool in clinical and research settings. Through arduous research, several blood-based biomarker assays have demonstrated notable results. In this review, we describe the metabolism of Aβ and the amyloid-targeting blood-based biomarkers of AD.
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Affiliation(s)
- Jung-Min Pyun
- Department of Neurology, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam-si, Republic of Korea
| | - Min Ju Kang
- Department of Neurology, Veterans Medical Research Institute, Veterans Health Service Medical Center, Seoul, Republic of Korea
| | - Nayoung Ryoo
- Department of Neurology, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam-si, Republic of Korea
| | - Jeewon Suh
- Department of Neurology, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam-si, Republic of Korea
| | - Young Chul Youn
- Department of Neurology, Chung-Ang University Hospital, Seoul, Republic of Korea
| | - Young Ho Park
- Department of Neurology, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam-si, Republic of Korea
| | - SangYun Kim
- Department of Neurology, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam-si, Republic of Korea
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11
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Metal- and UV- Catalyzed Oxidation Results in Trapped Amyloid-β Intermediates Revealing that Self-Assembly Is Required for Aβ-Induced Cytotoxicity. iScience 2020; 23:101537. [PMID: 33083713 PMCID: PMC7516296 DOI: 10.1016/j.isci.2020.101537] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/05/2020] [Accepted: 09/03/2020] [Indexed: 02/08/2023] Open
Abstract
Dityrosine (DiY), via the cross-linking of tyrosine residues, is a marker of protein oxidation, which increases with aging. Amyloid-β (Aβ) forms DiY in vitro and DiY-cross-linked Aβ is found in the brains of patients with Alzheimer disease. Metal- or UV- catalyzed oxidation of Aβ42 results in an increase in DiY cross-links. Using DiY as a marker of oxidation, we compare the self-assembly propensity and DiY cross-link formation for a non-assembly competent variant of Aβ42 (vAβ) with wild-type Aβ42. Oxidation results in the formation of trapped wild-type Aβ assemblies with increased DiY cross-links that are unable to elongate further. Assembly-incompetent vAβ and trapped Aβ assemblies are non-toxic to neuroblastoma cells at all stages of self-assembly, in contrast to oligomeric, non-cross-linked Aβ. These findings point to a mechanism of toxicity that necessitates dynamic self-assembly whereby trapped Aβ assemblies and assembly-incompetent variant Aβ are unable to result in cell death. Metal- (Cu2+ H202) or UV- catalyzedoxidation results in dityrosine (DiY) formation Oxidation results in DiY cross-link formation in Aβ and halts further assembly Non-assembling Aβ (trapped Aβ or variant Αβ monomer) is not cytotoxic
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12
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Huang YR, Liu RT. The Toxicity and Polymorphism of β-Amyloid Oligomers. Int J Mol Sci 2020; 21:E4477. [PMID: 32599696 PMCID: PMC7352971 DOI: 10.3390/ijms21124477] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 12/26/2022] Open
Abstract
It is widely accepted that β-amyloid oligomers (Aβos) play a key role in the progression of Alzheimer's disease (AD) by inducing neuron damage and cognitive impairment, but Aβos are highly heterogeneous in their size, structure and cytotoxicity, making the corresponding studies tough to carry out. Nevertheless, a number of studies have recently made remarkable progress in the describing the characteristics and pathogenicity of Aβos. We here review the mechanisms by which Aβos exert their neuropathogenesis for AD progression, including receptor binding, cell membrane destruction, mitochondrial damage, Ca2+ homeostasis dysregulation and tau pathological induction. We also summarize the characteristics and pathogenicity such as the size, morphology and cytotoxicity of dimers, trimers, Aβ*56 and spherical oligomers, and suggest that Aβos may play a different role at different phases of AD pathogenesis, resulting in differential consequences on neuronal synaptotoxicity and survival. It is warranted to investigate the temporal sequence of Aβos in AD human brain and examine the relationship between different Aβos and cognitive impairment.
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Affiliation(s)
- Ya-ru Huang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
- School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rui-tian Liu
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
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13
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Li S, Selkoe DJ. A mechanistic hypothesis for the impairment of synaptic plasticity by soluble Aβ oligomers from Alzheimer's brain. J Neurochem 2020; 154:583-597. [PMID: 32180217 DOI: 10.1111/jnc.15007] [Citation(s) in RCA: 138] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/28/2020] [Accepted: 03/02/2020] [Indexed: 12/18/2022]
Abstract
It is increasingly accepted that early cognitive impairment in Alzheimer's disease results in considerable part from synaptic dysfunction caused by the accumulation of a range of oligomeric assemblies of amyloid β-protein (Aβ). Most studies have used synthetic Aβ peptides to explore the mechanisms of memory deficits in rodent models, but recent work suggests that Aβ assemblies isolated from human (AD) brain tissue are far more potent and disease-relevant. Although reductionist experiments show Aβ oligomers to impair synaptic plasticity and neuronal viability, the responsible mechanisms are only partly understood. Glutamatergic receptors, GABAergic receptors, nicotinic receptors, insulin receptors, the cellular prion protein, inflammatory mediators, and diverse signaling pathways have all been suggested. Studies using AD brain-derived soluble Aβ oligomers suggest that only certain bioactive forms (principally small, diffusible oligomers) can disrupt synaptic plasticity, including by binding to plasma membranes and changing excitatory-inhibitory balance, perturbing mGluR, PrP, and other neuronal surface proteins, down-regulating glutamate transporters, causing glutamate spillover, and activating extrasynaptic GluN2B-containing NMDA receptors. We synthesize these emerging data into a mechanistic hypothesis for synaptic failure in Alzheimer's disease that can be modified as new knowledge is added and specific therapeutics are developed.
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Affiliation(s)
- Shaomin Li
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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14
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Flores-Muñoz C, Gómez B, Mery E, Mujica P, Gajardo I, Córdova C, Lopez-Espíndola D, Durán-Aniotz C, Hetz C, Muñoz P, Gonzalez-Jamett AM, Ardiles ÁO. Acute Pannexin 1 Blockade Mitigates Early Synaptic Plasticity Defects in a Mouse Model of Alzheimer's Disease. Front Cell Neurosci 2020; 14:46. [PMID: 32265655 PMCID: PMC7103637 DOI: 10.3389/fncel.2020.00046] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 02/18/2020] [Indexed: 12/11/2022] Open
Abstract
Synaptic loss induced by soluble oligomeric forms of the amyloid β peptide (sAβos) is one of the earliest events in Alzheimer’s disease (AD) and is thought to be the major cause of the cognitive deficits. These abnormalities rely on defects in synaptic plasticity, a series of events manifested as activity-dependent modifications in synaptic structure and function. It has been reported that pannexin 1 (Panx1), a nonselective channel implicated in cell communication and intracellular signaling, modulates the induction of excitatory synaptic plasticity under physiological contexts and contributes to neuronal death under inflammatory conditions. Here, we decided to study the involvement of Panx1 in functional and structural defects observed in excitatory synapses of the amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic (Tg) mice, an animal model of AD. We found an age-dependent increase in the Panx1 expression that correlates with increased Aβ levels in hippocampal tissue from Tg mice. Congruently, we also observed an exacerbated Panx1 activity upon basal conditions and in response to glutamate receptor activation. The acute inhibition of Panx1 activity with the drug probenecid (PBN) did not change neurodegenerative parameters such as amyloid deposition or astrogliosis, but it significantly reduced excitatory synaptic defects in the AD model by normalizing long-term potentiation (LTP) and depression and improving dendritic arborization and spine density in hippocampal neurons of the Tg mice. These results suggest a major contribution of Panx1 in the early mechanisms leading to the synaptopathy in AD. Indeed, PBN induced a reduction in the activation of p38 mitogen-activated protein kinase (MAPK), a kinase widely implicated in the early neurotoxic signaling in AD. Our data strongly suggest that an enhanced expression and activation of Panx1 channels contribute to the Aβ-induced cascades leading to synaptic dysfunction in AD.
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Affiliation(s)
- Carolina Flores-Muñoz
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.,Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - Bárbara Gómez
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Elena Mery
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Paula Mujica
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.,Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - Ivana Gajardo
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Claudio Córdova
- Laboratorio de Estructura y Función Celular, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Daniela Lopez-Espíndola
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso, Chile.,Centro de Investigaciones Biomédicas, Escuela de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Claudia Durán-Aniotz
- Center for Social and Cognitive Neuroscience (CSCN), School of Psychology, Universidad Adolfo Ibáñez, Santiago de Chile, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
| | - Claudio Hetz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile.,Center for Geroscience, Brain Health and Metabolism, Santiago, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Pablo Muñoz
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Centro de Investigaciones Biomédicas, Escuela de Medicina, Universidad de Valparaíso, Valparaíso, Chile
| | - Arlek M Gonzalez-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Álvaro O Ardiles
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile.,Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.,Centro Interdisciplinario de Estudios en Salud, Facultad de Medicina, Universidad de Valparaíso, Viña del Mar, Chile
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15
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APP Osaka Mutation in Familial Alzheimer's Disease-Its Discovery, Phenotypes, and Mechanism of Recessive Inheritance. Int J Mol Sci 2020; 21:ijms21041413. [PMID: 32093100 PMCID: PMC7073033 DOI: 10.3390/ijms21041413] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 12/14/2022] Open
Abstract
Alzheimer’s disease is believed to begin with synaptic dysfunction caused by soluble Aβ oligomers. When this oligomer hypothesis was proposed in 2002, there was no direct evidence that Aβ oligomers actually disrupt synaptic function to cause cognitive impairment in humans. In patient brains, both soluble and insoluble Aβ species always coexist, and therefore it is difficult to determine which pathologies are caused by Aβ oligomers and which are caused by amyloid fibrils. Thus, no validity of the oligomer hypothesis was available until the Osaka mutation was discovered. This mutation, which was found in a Japanese pedigree of familial Alzheimer’s disease, is the deletion of codon 693 of APP gene, resulting in mutant Aβ lacking the 22nd glutamate. Only homozygous carriers suffer from dementia. In vitro studies revealed that this mutation has a very unique character that accelerates Aβ oligomerization but does not form amyloid fibrils. Model mice expressing this mutation demonstrated that all pathologies of Alzheimer’s disease can be induced by Aβ oligomers alone. In this review, we describe the story behind the discovery of the Osaka mutation, summarize the mutant’s phenotypes, and propose a mechanism of its recessive inheritance.
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16
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Tamano H, Takiguchi M, Tanaka Y, Murakami T, Adlard PA, Bush AI, Takeda A. Preferential Neurodegeneration in the Dentate Gyrus by Amyloid β 1-42-Induced Intracellular Zn 2+Dysregulation and Its Defense Strategy. Mol Neurobiol 2019; 57:1875-1888. [PMID: 31865526 DOI: 10.1007/s12035-019-01853-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 12/11/2019] [Indexed: 12/18/2022]
Abstract
On the basis of the evidence that rapid intracellular Zn2+ dysregulation by amyloid β1-42 (Aβ1-42) in the normal hippocampus transiently induces cognitive decline, here we report preferential neurodegeneration in the dentate gyrus by Aβ1-42-induced intracellular Zn2+ dysregulation and its defense strategy. Neurodegeneration was preferentially observed in the dentate granule cell layer in the hippocampus after a single Aβ1-42 injection into the lateral ventricle but not in the CA1 and CA3 pyramidal cell layers, while intracellular Zn2+ dysregulation was extensively observed in the hippocampus in addition to the dentate gyrus. Neurodegeneration in the dentate granule cell layer was rescued after co-injection of extracellular and intracellular Zn2+ chelators, i.e., CaEDTA and ZnAF-2DA, respectively. Aβ1-42-induced cognitive impairment was also rescued by co-injection of CaEDTA and ZnAF-2DA. Pretreatment with dexamethasone, an inducer of metalothioneins, Zn2+-binding proteins rescued neurodegeneration in the dentate granule cell layer and cognitive impairment via blocking the intracellular Zn2+ dysregulation induced by Aβ1-42. The present study indicates that intracellular Zn2+ dysregulation induced by Aβ1-42 preferentially causes neurodegeneration in the dentate gyrus, resulting in hippocampus-dependent cognitive decline. It is likely that controlling intracellular Zn2+ dysregulation, which is induced by the rapid uptake of Zn-Aβ1-42 complexes, is a defense strategy for Alzheimer's disease pathogenesis.
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Affiliation(s)
- Haruna Tamano
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
| | - Mako Takiguchi
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
| | - Yukino Tanaka
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
| | - Taku Murakami
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
| | - Paul A Adlard
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Ashley I Bush
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Atsushi Takeda
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
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17
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Cline EN, Bicca MA, Viola KL, Klein WL. The Amyloid-β Oligomer Hypothesis: Beginning of the Third Decade. J Alzheimers Dis 2019; 64:S567-S610. [PMID: 29843241 PMCID: PMC6004937 DOI: 10.3233/jad-179941] [Citation(s) in RCA: 520] [Impact Index Per Article: 104.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The amyloid-β oligomer (AβO) hypothesis was introduced in 1998. It proposed that the brain damage leading to Alzheimer’s disease (AD) was instigated by soluble, ligand-like AβOs. This hypothesis was based on the discovery that fibril-free synthetic preparations of AβOs were potent CNS neurotoxins that rapidly inhibited long-term potentiation and, with time, caused selective nerve cell death (Lambert et al., 1998). The mechanism was attributed to disrupted signaling involving the tyrosine-protein kinase Fyn, mediated by an unknown toxin receptor. Over 4,000 articles concerning AβOs have been published since then, including more than 400 reviews. AβOs have been shown to accumulate in an AD-dependent manner in human and animal model brain tissue and, experimentally, to impair learning and memory and instigate major facets of AD neuropathology, including tau pathology, synapse deterioration and loss, inflammation, and oxidative damage. As reviewed by Hayden and Teplow in 2013, the AβO hypothesis “has all but supplanted the amyloid cascade.” Despite the emerging understanding of the role played by AβOs in AD pathogenesis, AβOs have not yet received the clinical attention given to amyloid plaques, which have been at the core of major attempts at therapeutics and diagnostics but are no longer regarded as the most pathogenic form of Aβ. However, if the momentum of AβO research continues, particularly efforts to elucidate key aspects of structure, a clear path to a successful disease modifying therapy can be envisioned. Ensuring that lessons learned from recent, late-stage clinical failures are applied appropriately throughout therapeutic development will further enable the likelihood of a successful therapy in the near-term.
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Affiliation(s)
- Erika N Cline
- Department of Neurobiology, Cognitive Neurology and Alzheimer's Disease Center, International Institute for Nanotechnology, and Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
| | - Maíra Assunção Bicca
- Department of Neurobiology, Cognitive Neurology and Alzheimer's Disease Center, International Institute for Nanotechnology, and Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
| | - Kirsten L Viola
- Department of Neurobiology, Cognitive Neurology and Alzheimer's Disease Center, International Institute for Nanotechnology, and Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
| | - William L Klein
- Department of Neurobiology, Cognitive Neurology and Alzheimer's Disease Center, International Institute for Nanotechnology, and Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
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18
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Mehrazma B, Rauk A. Exploring Amyloid-β Dimer Structure Using Molecular Dynamics Simulations. J Phys Chem A 2019; 123:4658-4670. [PMID: 31082235 DOI: 10.1021/acs.jpca.8b11251] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A major hallmark of Alzheimer's disease (AD) is the aggregation of amyloid-β peptides in the brains of people afflicted by the disease. The exact pathway to this catastrophic event is unknown. In this work, a total of 9.5 μs molecular dynamics simulations have been performed to investigate the structure and dynamics of the smallest form of toxic Aβ oligomers, i.e., the Aβ dimers. This study suggests that specific hydrophobic regions are vital in the aggregation process. Different possible structures for Aβ dimers are reported along with their relative binding affinity. These data may be used to design better Aβ-aggregation inhibitors. The diversity of the dimer structures suggests several aggregation pathways.
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Affiliation(s)
- Banafsheh Mehrazma
- Department of Chemistry , University of Calgary , Calgary AB , Canada T2N 1N4
| | - Arvi Rauk
- Department of Chemistry , University of Calgary , Calgary AB , Canada T2N 1N4
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19
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Cline EN, Das A, Bicca MA, Mohammad SN, Schachner LF, Kamel JM, DiNunno N, Weng A, Paschall JD, Bu RL, Khan FM, Rollins MG, Ives AN, Shekhawat G, Nunes-Tavares N, de Mello FG, Compton PD, Kelleher NL, Klein WL. A novel crosslinking protocol stabilizes amyloid β oligomers capable of inducing Alzheimer's-associated pathologies. J Neurochem 2019; 148:822-836. [PMID: 30565253 DOI: 10.1111/jnc.14647] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 12/09/2018] [Accepted: 12/11/2018] [Indexed: 12/27/2022]
Abstract
Amyloid β oligomers (AβOs) accumulate early in Alzheimer's disease (AD) and experimentally cause memory dysfunction and the major pathologies associated with AD, for example, tau abnormalities, synapse loss, oxidative damage, and cognitive dysfunction. In order to develop the most effective AβO-targeting diagnostics and therapeutics, the AβO structures contributing to AD-associated toxicity must be elucidated. Here, we investigate the structural properties and pathogenic relevance of AβOs stabilized by the bifunctional crosslinker 1,5-difluoro-2,4-dinitrobenzene (DFDNB). We find that DFDNB stabilizes synthetic Aβ in a soluble oligomeric conformation. With DFDNB, solutions of Aβ that would otherwise convert to large aggregates instead yield solutions of stable AβOs, predominantly in the 50-300 kDa range, that are maintained for at least 12 days at 37°C. Structures were determined by biochemical and native top-down mass spectrometry analyses. Assayed in neuronal cultures and i.c.v.-injected mice, the DFDNB-stabilized AβOs were found to induce tau hyperphosphorylation, inhibit choline acetyltransferase, and provoke neuroinflammation. Most interestingly, DFDNB crosslinking was found to stabilize an AβO conformation particularly potent in inducing memory dysfunction in mice. Taken together, these data support the utility of DFDNB crosslinking as a tool for stabilizing pathogenic AβOs in structure-function studies.
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Affiliation(s)
- Erika N Cline
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
| | - Arighno Das
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
| | | | - Saad N Mohammad
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA.,Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
| | - Luis F Schachner
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois, USA
| | - Josette M Kamel
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
| | - Nadia DiNunno
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
| | - Anthea Weng
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
| | - Jacob D Paschall
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
| | - Riana Lo Bu
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
| | - Faraz M Khan
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
| | - Madeline G Rollins
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
| | - Ashley N Ives
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois, USA
| | - Gajendra Shekhawat
- Department of Material Science and Engineering, Northwestern University, Evanston, Illinois, USA
| | - Nilson Nunes-Tavares
- Instituo de Biofisica Carlo Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernando G de Mello
- Instituo de Biofisica Carlo Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Philip D Compton
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois, USA
| | - Neil L Kelleher
- Departments of Chemistry and Molecular Biosciences and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois, USA
| | - William L Klein
- Department of Neurobiology, Northwestern University, Evanston, Illinois, USA
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20
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Khan SS, LaCroix M, Boyle G, Sherman MA, Brown JL, Amar F, Aldaco J, Lee MK, Bloom GS, Lesné SE. Bidirectional modulation of Alzheimer phenotype by alpha-synuclein in mice and primary neurons. Acta Neuropathol 2018; 136:589-605. [PMID: 29995210 DOI: 10.1007/s00401-018-1886-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/14/2018] [Accepted: 07/07/2018] [Indexed: 01/01/2023]
Abstract
α-Synuclein (αSyn) histopathology defines several neurodegenerative disorders, including Parkinson's disease, Lewy body dementia, and Alzheimer's disease (AD). However, the functional link between soluble αSyn and disease etiology remains elusive, especially in AD. We, therefore, genetically targeted αSyn in APP transgenic mice modeling AD and mouse primary neurons. Our results demonstrate bidirectional modulation of behavioral deficits and pathophysiology by αSyn. Overexpression of human wild-type αSyn in APP animals markedly reduced amyloid deposition but, counter-intuitively, exacerbated deficits in spatial memory. It also increased extracellular amyloid-β oligomers (AβOs), αSyn oligomers, exacerbated tau conformational and phosphorylation variants associated with AD, and enhanced neuronal cell cycle re-entry (CCR), a frequent prelude to neuron death in AD. Conversely, ablation of the SNCA gene encoding for αSyn in APP mice improved memory retention in spite of increased plaque burden. Reminiscent of the effect of MAPT ablation in APP mice, SNCA deletion prevented premature mortality. Moreover, the absence of αSyn decreased extracellular AβOs, ameliorated CCR, and rescued postsynaptic marker deficits. In summary, this complementary, bidirectional genetic approach implicates αSyn as an essential mediator of key phenotypes in AD and offers new functional insight into αSyn pathophysiology.
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21
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Silverman JM, Gibbs E, Peng X, Martens KM, Balducci C, Wang J, Yousefi M, Cowan CM, Lamour G, Louadi S, Ban Y, Robert J, Stukas S, Forloni G, Hsiung GYR, Plotkin SS, Wellington CL, Cashman NR. A Rational Structured Epitope Defines a Distinct Subclass of Toxic Amyloid-beta Oligomers. ACS Chem Neurosci 2018; 9:1591-1606. [PMID: 29614860 DOI: 10.1021/acschemneuro.7b00469] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Oligomers of amyloid-β (AβO) are deemed key in synaptotoxicity and amyloid seeding of Alzheimer's disease (AD). However, the heterogeneous and dynamic nature of AβO and inadequate markers for AβO subtypes have stymied effective AβO identification and therapeutic targeting in vivo. We identified an AβO-subclass epitope defined by differential solvent orientation of the lysine 28 side chain in a constrained loop of serine-asparagine-lysine (cSNK), rarely displayed in molecular dynamics simulations of monomer and fibril ensembles. A mouse monoclonal antibody targeting AβOcSNK recognizes ∼50-60 kDa SDS-resistant soluble Aβ assemblages in AD brain and prolongs the lag phase of Aβ aggregation in vitro. Acute peripheral infusion of a murine IgG1 anti-AβOcSNK in two AD mouse models reduced soluble brain Aβ aggregates by 20-30%. Chronic cSNK peptide immunization of APP/PS1 mice engendered an anti-AβOcSNK IgG1 response without epitope spreading to Aβ monomers or fibrils and was accompanied by preservation of global PSD95 expression and improved cued fear memory. Our data indicate that the oligomer subtype AβOcSNK participates in synaptotoxicity and propagation of Aβ aggregation in vitro and in vivo.
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Affiliation(s)
- Judith M. Silverman
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada
| | - Ebrima Gibbs
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada
| | - Xubiao Peng
- Department of Physics and Astronomy, Genome Sciences and Technology Program, Bioinformatics, Institute for Applied Math, University of British Columbia, Room
311, 6356 Agricultural Road, Vancouver, BC V6T 1Z2, Canada
| | - Kris M. Martens
- Department of Pathology and Laboratory Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Claudia Balducci
- IRCCS, Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Via La Masa, 19, 20156 Milano, Italy
| | - Jing Wang
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada
| | - Masoud Yousefi
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada
| | - Catherine M. Cowan
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada
| | - Guillaume Lamour
- Chemistry Department, University of British Columbia, Rm D223, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Sarah Louadi
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada
| | - Yuxin Ban
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada
| | - Jerome Robert
- Department of Pathology and Laboratory Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Sophie Stukas
- Department of Pathology and Laboratory Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Gianluigi Forloni
- IRCCS, Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Via La Masa, 19, 20156 Milano, Italy
| | - Ging-Yuek R. Hsiung
- UBC Hospital Clinic for Alzheimer Disease and Related Disorders, Department of Medicine, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Steven S. Plotkin
- Department of Physics and Astronomy, Genome Sciences and Technology Program, Bioinformatics, Institute for Applied Math, University of British Columbia, Room
311, 6356 Agricultural Road, Vancouver, BC V6T 1Z2, Canada
| | - Cheryl L. Wellington
- Department of Pathology and Laboratory Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Neil R. Cashman
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada
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22
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Structural and kinetic basis for the selectivity of aducanumab for aggregated forms of amyloid-β. Sci Rep 2018; 8:6412. [PMID: 29686315 PMCID: PMC5913127 DOI: 10.1038/s41598-018-24501-0] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 04/05/2018] [Indexed: 12/21/2022] Open
Abstract
Aducanumab, a human-derived antibody targeting amyloid-β (Aβ), is in Phase 3 clinical trials for the treatment of Alzheimer’s disease. Biochemical and structural analyses show that aducanumab binds a linear epitope formed by amino acids 3–7 of the Aβ peptide. Aducanumab discriminates between monomers and oligomeric or fibrillar aggregates based on weak monovalent affinity, fast binding kinetics and strong avidity for epitope-rich aggregates. Direct comparative studies with analogs of gantenerumab, bapineuzumab and solanezumab demonstrate clear differentiation in the binding properties of these antibodies. The crystal structure of the Fab fragment of aducanumab bound to its epitope peptide reveals that aducanumab binds to the N terminus of Aβ in an extended conformation, distinct from those seen in structures with other antibodies that target this immunodominant epitope. Aducanumab recognizes a compact epitope that sits in a shallow pocket on the antibody surface. In silico analyses suggest that aducanumab interacts weakly with the Aβ monomer and may accommodate a variety of peptide conformations, further supporting its selectivity for Aβ aggregates. Our studies provide a structural rationale for the low affinity of aducanumab for non-pathogenic monomers and its greater selectivity for aggregated forms than is seen for other Aβ-targeting antibodies.
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23
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Geerts H, Spiros A, Roberts P. Impact of amyloid-beta changes on cognitive outcomes in Alzheimer's disease: analysis of clinical trials using a quantitative systems pharmacology model. Alzheimers Res Ther 2018; 10:14. [PMID: 29394903 PMCID: PMC5797372 DOI: 10.1186/s13195-018-0343-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 01/15/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Despite a tremendous amount of information on the role of amyloid in Alzheimer's disease (AD), almost all clinical trials testing this hypothesis have failed to generate clinically relevant cognitive effects. METHODS We present an advanced mechanism-based and biophysically realistic quantitative systems pharmacology computer model of an Alzheimer-type neuronal cortical network that has been calibrated with Alzheimer Disease Assessment Scale, cognitive subscale (ADAS-Cog) readouts from historical clinical trials and simulated the differential impact of amyloid-beta (Aβ40 and Aβ42) oligomers on glutamate and nicotinic neurotransmission. RESULTS Preclinical data suggest a beneficial effect of shorter Aβ forms within a limited dose range. Such a beneficial effect of Aβ40 on glutamate neurotransmission in human patients is absolutely necessary to reproduce clinical data on the ADAS-Cog in minimal cognitive impairment (MCI) patients with and without amyloid load, the effect of APOE genotype effect on the slope of the cognitive trajectory over time in placebo AD patients and higher sensitivity to cholinergic manipulation with scopolamine associated with higher Aβ in MCI subjects. We further derive a relationship between units of Aβ load in our model and the standard uptake value ratio from amyloid imaging. When introducing the documented clinical pharmacodynamic effects on Aβ levels for various amyloid-related clinical interventions in patients with low Aβ baseline, the platform predicts an overall significant worsening for passive vaccination with solanezumab, beta-secretase inhibitor verubecestat and gamma-secretase inhibitor semagacestat. In contrast, all three interventions improved cognition in subjects with moderate to high baseline Aβ levels, with verubecestat anticipated to have the greatest effect (around ADAS-Cog value 1.5 points), solanezumab the lowest (0.8 ADAS-Cog value points) and semagacestat in between. This could explain the success of many amyloid interventions in transgene animals with an artificial high level of Aβ, but not in AD patients with a large variability of amyloid loads. CONCLUSIONS If these predictions are confirmed in post-hoc analyses of failed clinical amyloid-modulating trials, one should question the rationale behind testing these interventions in early and prodromal subjects with low or zero amyloid load.
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Affiliation(s)
- Hugo Geerts
- In Silico Biosciences, 686 Westwind Dr, Berwyn, PA, 1312, USA.
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Athan Spiros
- In Silico Biosciences, 686 Westwind Dr, Berwyn, PA, 1312, USA
| | - Patrick Roberts
- In Silico Biosciences, 686 Westwind Dr, Berwyn, PA, 1312, USA
- Amazon AI AWS, Portland, OR, USA
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24
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Zimbone S, Monaco I, Gianì F, Pandini G, Copani AG, Giuffrida ML, Rizzarelli E. Amyloid Beta monomers regulate cyclic adenosine monophosphate response element binding protein functions by activating type-1 insulin-like growth factor receptors in neuronal cells. Aging Cell 2018; 17. [PMID: 29094448 PMCID: PMC5770784 DOI: 10.1111/acel.12684] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2017] [Indexed: 11/29/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder associated with synaptic dysfunction, pathological accumulation of β-amyloid (Aβ), and neuronal loss. The self-association of Aβ monomers into soluble oligomers seems to be crucial for the development of neurotoxicity (J. Neurochem., 00, 2007 and 1172). Aβ oligomers have been suggested to compromise neuronal functions in AD by reducing the expression levels of the CREB target gene and brain-derived neurotrophic factor (BDNF) (J. Neurosci., 27, 2007 and 2628; Neurobiol. Aging, 36, 2015 and 20406 Mol. Neurodegener., 6, 2011 and 60). We previously reported a broad neuroprotective activity of physiological Aβ monomers, involving the activation of type-1 insulin-like growth factor receptors (IGF-IRs) (J. Neurosci., 29, 2009 and 10582, Front Cell Neurosci., 9, 2015 and 297). We now provide evidence that Aβ monomers, by activating the IGF-IR-stimulated PI3-K/AKT pathway, induce the activation of CREB in neurons and sustain BDNF transcription and release.
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Affiliation(s)
- Stefania Zimbone
- Institute of Biostructures and Bioimaging; National Council of Research (IBB-CNR); Via Paolo Gaifami 18 95126 Catania Italy
| | - Irene Monaco
- Institute of Biostructures and Bioimaging; National Council of Research (IBB-CNR); Via Paolo Gaifami 18 95126 Catania Italy
| | - Fiorenza Gianì
- Endocrinology, Department of Clinical and Experimental Medicine; Garibaldi-Nesima Medical Center; University of Catania; via Palermo 636 95122 Catania Italy
| | - Giuseppe Pandini
- Endocrinology, Department of Clinical and Experimental Medicine; Garibaldi-Nesima Medical Center; University of Catania; via Palermo 636 95122 Catania Italy
| | - Agata G. Copani
- Institute of Biostructures and Bioimaging; National Council of Research (IBB-CNR); Via Paolo Gaifami 18 95126 Catania Italy
- Department of Drug Sciences; University of Catania; Viale A. Doria 6 95125 Catania Italy
| | - Maria Laura Giuffrida
- Institute of Biostructures and Bioimaging; National Council of Research (IBB-CNR); Via Paolo Gaifami 18 95126 Catania Italy
| | - Enrico Rizzarelli
- Institute of Biostructures and Bioimaging; National Council of Research (IBB-CNR); Via Paolo Gaifami 18 95126 Catania Italy
- Department of Chemical Sciences; University of Catania; Viale A. Doria 6 95125 Catania Italy
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25
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Cuddy LK, Seah C, Pasternak SH, Rylett RJ. Amino-Terminal β-Amyloid Antibody Blocks β-Amyloid-Mediated Inhibition of the High-Affinity Choline Transporter CHT. Front Mol Neurosci 2017; 10:361. [PMID: 29163036 PMCID: PMC5681948 DOI: 10.3389/fnmol.2017.00361] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 10/19/2017] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's disease (AD) is a common age-related neurodegenerative disorder that is characterized by progressive cognitive decline. The deficits in cognition and attentional processing that are observed clinically in AD are linked to impaired function of cholinergic neurons that release the neurotransmitter acetylcholine (ACh). The high-affinity choline transporter (CHT) is present at the presynaptic cholinergic nerve terminal and is responsible for the reuptake of choline produced by hydrolysis of ACh following its release. Disruption of CHT function leads to decreased choline uptake and ACh synthesis, leading to impaired cholinergic neurotransmission. We report here that cell-derived β-amyloid peptides (Aβ) decrease choline uptake activity and cell surface CHT protein levels in SH-SY5Y neural cells. Moreover, we make the novel observation that the amount of CHT protein localizing to early endosomes and lysosomes is decreased significantly in cells that have been treated with cell culture medium that contains Aβ peptides released from neural cells. The Aβ-mediated loss of CHT proteins from lysosomes is prevented by blocking lysosomal degradation of CHT with the lysosome inhibitor bafilomycin A1 (BafA1). BafA1 also attenuated the Aβ-mediated decrease in CHT cell surface expression. Interestingly, however, lysosome inhibition did not block the effect of Aβ on CHT activity. Importantly, neutralizing Aβ using an anti-Aβ antibody directed at the N-terminal amino acids 1-16 of Aβ, but not by an antibody directed at the mid-region amino acids 22-35 of Aβ, attenuates the effect of Aβ on CHT activity and trafficking. This indicates that a specific N-terminal Aβ epitope, or specific conformation of soluble Aβ, may impair CHT activity. Therefore, Aβ immunotherapy may be a more effective therapeutic strategy for slowing the progression of cognitive decline in AD than therapies designed to promote CHT cell surface levels.
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Affiliation(s)
- Leah K Cuddy
- Molecular Medicine Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Claudia Seah
- Molecular Medicine Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada
| | - Stephen H Pasternak
- Molecular Medicine Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada.,Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - R Jane Rylett
- Molecular Medicine Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
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26
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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] [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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27
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Brody DL, Jiang H, Wildburger N, Esparza TJ. Non-canonical soluble amyloid-beta aggregates and plaque buffering: controversies and future directions for target discovery in Alzheimer's disease. Alzheimers Res Ther 2017; 9:62. [PMID: 28818091 PMCID: PMC5561579 DOI: 10.1186/s13195-017-0293-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The specific amyloid-beta (Aβ) species or other amyloid-precursor protein cleavage products that are most directly related to human neurodegeneration and clinical dementia of the Alzheimer's type have not yet been directly identified. Without a clear understanding of the most relevant species, it is difficult to determine whether therapeutic candidates successfully engaged the correct target(s). Here, we review some of the controversies regarding soluble Aβ aggregates (also termed oligomers, dimers, trimers, Aβ*56, amylospheroids, etc.) and propose experiments designed to move forward towards new therapeutic approaches. Specifically, we review the increasing evidence for the relevance of non-canonical forms of Aβ, the much more potent toxicity attributable to native species than to synthetic Aβ, and the evidence implicating the ratio of soluble Aβ aggregates to plaques in differentiating demented patients from non-demented high Aβ plaque pathology controls. To move forward, we propose four related directions. 1) Narrowing the focus to species derived from human Alzheimer's disease (AD) brain tissue, as opposed to synthetic Aβ, cell culture-derived species, or species primarily present in animal models. 2) Careful study of differences between patients with dementia of the Alzheimer's type vs. non-demented controls with high Aβ plaque pathology. This will involve testing the hypothesis that, under some circumstances, plaques may buffer soluble toxic species, but later release them into the surrounding milieu. 3) Investigations of other protein constituents of soluble Aβ aggregates in addition to Aβ itself. Our initial data based on chemical cleavage experiments indicate that other proteins do appear to be part of the human brain soluble Aβ aggregates. 4) Multimodal experimental assessments of toxicity, including longer term effects on synapse loss, related deleterious cellular responses, and degeneration in human-derived neuron-like cells. Overall, the goal is to identify specific Aβ species, other amyloid precursor protein cleavage products, or other key proteins in aggregates present in human AD brains, less abundant in non-demented high pathology control brains, and robustly toxic in a wide variety of relevant assays. These species themselves, the enzymatic or cellular processes involved in their production, and their routes of clearance would be highly relevant therapeutic targets for dementia of the Alzheimer's type.
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Affiliation(s)
- David L. Brody
- Department of Neurology, Washington University School of Medicine, 660 South Euclid Avenue, Box 8111, St Louis, Missouri 63110 USA
- Hope Center for Neurological Disorders, Washington University School of Medicine, 660 South Euclid Avenue, Box 8111, St Louis, Missouri 63110 USA
| | - Hao Jiang
- Department of Neurology, Washington University School of Medicine, 660 South Euclid Avenue, Box 8111, St Louis, Missouri 63110 USA
| | - Norelle Wildburger
- Department of Neurology, Washington University School of Medicine, 660 South Euclid Avenue, Box 8111, St Louis, Missouri 63110 USA
| | - Thomas J. Esparza
- Department of Neurology, Washington University School of Medicine, 660 South Euclid Avenue, Box 8111, St Louis, Missouri 63110 USA
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28
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Alzheimer's disease as oligomeropathy. Neurochem Int 2017; 119:57-70. [PMID: 28821400 DOI: 10.1016/j.neuint.2017.08.010] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/30/2017] [Accepted: 08/13/2017] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder and is characterized by pathological aggregates of amyloid β-protein (Aβ) and tau protein. On the basis of genetic evidence, biochemical data, and animal models, Aβ has been suggested to be responsible for the pathogenesis of AD (the amyloid hypothesis). Aβ molecules tend to aggregate to form oligomers, protofibrils, and mature fibrils. Although mature fibrils in the final stage have been thought to be the cause of AD pathogenesis, recent studies using synthetic Aβ peptides, a cell culture model, Aβ precursor protein transgenic mice models, and human samples, such as cerebrospinal fluids and postmortem brains of AD patients, suggest that pre-fibrillar forms (oligomers of Aβ) are more deleterious than are extracellular fibril forms. Based on this recent evidence showing that oligomers have a central role in the pathogenesis of AD, the term "oligomeropathy" could be used to define AD and other protein-misfolding diseases. In this review, I discuss recent developments in the "oligomer hypothesis" including our research findings regarding the pathogenesis of AD.
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29
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Amar F, Sherman MA, Rush T, Larson M, Boyle G, Chang L, Götz J, Buisson A, Lesné SE. The amyloid-β oligomer Aβ*56 induces specific alterations in neuronal signaling that lead to tau phosphorylation and aggregation. Sci Signal 2017; 10:10/478/eaal2021. [PMID: 28487416 DOI: 10.1126/scisignal.aal2021] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Oligomeric forms of amyloid-forming proteins are believed to be the principal initiating bioactive species in many neurodegenerative disorders, including Alzheimer's disease (AD). Amyloid-β (Aβ) oligomers are implicated in AD-associated phosphorylation and aggregation of the microtubule-associated protein tau. To investigate the specific molecular pathways activated by different assemblies, we isolated various forms of Aβ from Tg2576 mice, which are a model for AD. We found that Aβ*56, a 56-kDa oligomer that is detected before patients develop overt signs of AD, induced specific changes in neuronal signaling. In primary cortical neurons, Aβ*56 interacted with N-methyl-d-aspartate receptors (NMDARs), increased NMDAR-dependent Ca2+ influx, and consequently increased intracellular calcium concentrations and the activation of Ca2+-dependent calmodulin kinase IIα (CaMKIIα). In cultured neurons and in the brains of Tg2576 mice, activated CaMKIIα was associated with increased site-specific phosphorylation and missorting of tau, both of which are associated with AD pathology. In contrast, exposure of cultured primary cortical neurons to other oligomeric Aβ forms (dimers and trimers) did not trigger these effects. Our results indicate that distinct Aβ assemblies activate neuronal signaling pathways in a selective manner and that dissecting the molecular events caused by each oligomer may inform more effective therapeutic strategies.
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Affiliation(s)
- Fatou Amar
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA.,N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55414, USA.,Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
| | - Mathew A Sherman
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA.,N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55414, USA.,Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
| | - Travis Rush
- INSERM, U1216, Université Grenoble Alpes, Grenoble Institut des Neurosciences, BP 170, Grenoble Cedex 9, F-38042, France
| | - Megan Larson
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA.,N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55414, USA.,Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
| | - Gabriel Boyle
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA.,N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55414, USA.,Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
| | - Liu Chang
- Sydney Medical School, Brain and Mind Research Institute, University of Sydney, Camperdown, Sydney, New South Wales 2050, Australia
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Alain Buisson
- INSERM, U1216, Université Grenoble Alpes, Grenoble Institut des Neurosciences, BP 170, Grenoble Cedex 9, F-38042, France
| | - Sylvain E Lesné
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA. .,N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55414, USA.,Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
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30
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Ford L, Crossley M, Vadukul DM, Kemenes G, Serpell LC. Structure-dependent effects of amyloid-β on long-term memory in Lymnaea stagnalis. FEBS Lett 2017; 591:1236-1246. [PMID: 28337747 PMCID: PMC5435943 DOI: 10.1002/1873-3468.12633] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/24/2017] [Accepted: 03/20/2017] [Indexed: 12/03/2022]
Abstract
Amyloid‐β (Aβ) peptides are implicated in the causation of memory loss, neuronal impairment, and neurodegeneration in Alzheimer's disease. Our recent work revealed that Aβ 1–42 and Aβ 25–35 inhibit long‐term memory (LTM) recall in Lymnaea stagnalis (pond snail) in the absence of cell death. Here, we report the characterization of the active species prepared under different conditions, describe which Aβ species is present in brain tissue during the behavioral recall time point and relate the sequence and structure of the oligomeric species to the resulting neuronal properties and effect on LTM. Our results suggest that oligomers are the key toxic Aβ1–42 structures, which likely affect LTM through synaptic plasticity pathways, and that Aβ 1–42 and Aβ 25–35 cannot be used as interchangeable peptides.
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Affiliation(s)
- Lenzie Ford
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonUK
- Present address: Department of NeuroscienceColumbia UniversityNew YorkNY10032USA
- Present address: Howard Hughes Medical InstituteColumbia UniversityNew YorkNY10032USA
| | - Michael Crossley
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonUK
| | - Devkee M. Vadukul
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonUK
| | - György Kemenes
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonUK
| | - Louise C. Serpell
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonUK
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31
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Ng RCL, Chan KH. Potential Neuroprotective Effects of Adiponectin in Alzheimer's Disease. Int J Mol Sci 2017; 18:E592. [PMID: 28282917 PMCID: PMC5372608 DOI: 10.3390/ijms18030592] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 02/20/2017] [Accepted: 02/28/2017] [Indexed: 12/11/2022] Open
Abstract
The adipocyte-secreted protein adiponectin (APN) has several protective functions in the peripheral tissues including insulin sensitizing, anti-inflammatory and anti-oxidative effects that may benefit neurodegenerative diseases such as Alzheimer's disease (AD). In addition, dysregulation of cerebral insulin sensitivities and signaling activities have been implicated in AD. Emerging insights into the mechanistic roles of adiponectin and AD highlight the potential therapeutic effects for AD through insulin signaling.
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Affiliation(s)
- Roy Chun-Laam Ng
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
- Research Center of Heart, Brain, Hormone and Healthy Aging, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Koon-Ho Chan
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
- Research Center of Heart, Brain, Hormone and Healthy Aging, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
- Hong Kong University Alzheimer's Disease Research Network, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
- Neuroimmunology and Neuroinflammation Research Laboratory, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
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32
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Assessing the Effects of Acute Amyloid β Oligomer Exposure in the Rat. Int J Mol Sci 2016; 17:ijms17091390. [PMID: 27563885 PMCID: PMC5037670 DOI: 10.3390/ijms17091390] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 08/16/2016] [Accepted: 08/18/2016] [Indexed: 11/28/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia, yet there are no therapeutic treatments that can either cure or delay its onset. Currently, the pathogenesis of AD is still uncertain, especially with respect to how the disease develops from a normal healthy brain. Amyloid β oligomers (AβO) are highly neurotoxic proteins and are considered potential initiators to the pathogenesis of AD. Rat brains were exposed to AβO via bilateral intracerebroventricular injections. Rats were then euthanized at either 1, 3, 7 or 21-days post surgery. Rat behavioural testing was performed using the Morris water maze and open field tests. Post-mortem brain tissue was immunolabelled for Aβ, microglia, and cholinergic neurons. Rats exposed to AβO showed deficits in spatial learning and anxiety-like behaviour. Acute positive staining for Aβ was only observed in the corpus callosum surrounding the lateral ventricles. AβO exposed rat brains also showed a delayed increase in activated microglia within the corpus callosum and a decreased number of cholinergic neurons within the basal forebrain. Acute exposure to AβO resulted in mild learning and memory impairments with co-concomitant white matter pathology within the corpus callosum and cholinergic cell loss within the basal forebrain. Results suggest that acute exposure to AβO in the rat may be a useful tool in assessing the early phases for the pathogenesis of AD.
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33
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Cannula implantation into the lateral ventricle does not adversely affect recognition or spatial working memory. Neurosci Lett 2016; 628:171-8. [DOI: 10.1016/j.neulet.2016.06.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/16/2016] [Accepted: 06/18/2016] [Indexed: 12/21/2022]
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34
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Savioz A, Giannakopoulos P, Herrmann FR, Klein WL, Kövari E, Bouras C, Giacobini E. A Study of Aβ Oligomers in the Temporal Cortex and Cerebellum of Patients with Neuropathologically Confirmed Alzheimer's Disease Compared to Aged Controls. NEURODEGENER DIS 2016; 16:398-406. [PMID: 27400224 DOI: 10.1159/000446283] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 04/19/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Investigations of Aβ oligomers in neuropathologically confirmed Alzheimer's disease (AD) are still scarce. We report neurohistopathological and biochemical analyses using antibodies against tau and amyloid β (Aβ) pathology. METHODS Thirty elderly AD patients and 43 age-matched controls with or without deposition of amyloid plaques (AP) were analyzed by immunohistochemistry. In 21 cases with available fresh tissue, Western blots were also performed. Neuropathological analysis included quantitative assessment of neurofibrillary tangles (NFT), AP and Aβ oligomer densities in the mesial temporal cortex (TC). RESULTS NFT, fibrillar amyloid and Aβ oligomeric deposit densities were significantly higher in AD patients than in controls. There was no relationship between oligomeric Aβ densities and Braak NFT staging scores. Furthermore, Aβ oligomer expression was closely correlated with Aβ plaques in the TC. By Western blot, Aβ oligomers were observed in AD patients, in plaque-free controls, in 1 'tangle-only AD' case, as well as in the cerebellum. A band near 55 kDa was the only Western blot signal that was significantly increased in the TC of AD patients compared to controls as well as less expressed in the cerebellum. CONCLUSION These results suggest that a putative dodecamer, near 55 kDa, may contribute to AD vulnerability of the TC.
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Affiliation(s)
- Armand Savioz
- Departments of Mental Health and Psychiatry, University of Geneva, Geneva, Switzerland
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35
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Rudinskiy N, Fuerer C, Demurtas D, Zamorano S, De Piano C, Herrmann AG, Spires-Jones TL, Oeckl P, Otto M, Frosch MP, Moniatte M, Hyman BT, Schmid AW. Amyloid‐beta oligomerization is associated with the generation of a typical peptide fragment fingerprint. Alzheimers Dement 2016; 12:996-1013. [DOI: 10.1016/j.jalz.2016.03.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 02/29/2016] [Accepted: 03/19/2016] [Indexed: 10/21/2022]
Affiliation(s)
- Nikita Rudinskiy
- Department of Neurology, Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital Harvard Medical School Charlestown MA USA
| | - Christophe Fuerer
- School of Life Sciences, Proteomics Core Facility Ecole Polytechnique Fédérale de Lausanne (EPFL) Lausanne Switzerland
| | - Davide Demurtas
- School of Basic Sciences, Interdisciplinary Centre for Electron Microscopy (CIME) Ecole Polytechnique Fédérale de Lausanne (EPFL) Lausanne Switzerland
| | - Sebastian Zamorano
- School of Life Sciences, Proteomics Core Facility Ecole Polytechnique Fédérale de Lausanne (EPFL) Lausanne Switzerland
| | - Cyntia De Piano
- School of Life Sciences, Proteomics Core Facility Ecole Polytechnique Fédérale de Lausanne (EPFL) Lausanne Switzerland
| | - Abigail G. Herrmann
- Center for Cognitive and Neural Systems The University of Edinburgh Edinburgh Scotland
- Centre for Dementia Prevention The University of Edinburgh Edinburgh Scotland
- Euan MacDonald Centre for Motorneurone Disease The University of Edinburgh Edinburgh Scotland
| | - Tara L. Spires-Jones
- Center for Cognitive and Neural Systems The University of Edinburgh Edinburgh Scotland
- Centre for Dementia Prevention The University of Edinburgh Edinburgh Scotland
- Euan MacDonald Centre for Motorneurone Disease The University of Edinburgh Edinburgh Scotland
| | - Patrick Oeckl
- Department of Neurology Ulm University Hospital Ulm Germany
| | - Markus Otto
- Department of Neurology Ulm University Hospital Ulm Germany
| | - Matthew P. Frosch
- Massachusetts General Hospital and Harvard Medical School Massachusetts General Institute for Neurodegenerative Disease Charlestown MA USA
| | - Marc Moniatte
- School of Life Sciences, Proteomics Core Facility Ecole Polytechnique Fédérale de Lausanne (EPFL) Lausanne Switzerland
| | - Bradley T. Hyman
- Department of Neurology, Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital Harvard Medical School Charlestown MA USA
| | - Adrien W. Schmid
- School of Life Sciences, Proteomics Core Facility Ecole Polytechnique Fédérale de Lausanne (EPFL) Lausanne Switzerland
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36
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Forloni G, Artuso V, La Vitola P, Balducci C. Oligomeropathies and pathogenesis of Alzheimer and Parkinson's diseases. Mov Disord 2016; 31:771-81. [DOI: 10.1002/mds.26624] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 02/11/2016] [Accepted: 02/15/2016] [Indexed: 12/13/2022] Open
Affiliation(s)
- Gianluigi Forloni
- Departement of Neuroscience; IRCCS, Istituto di Ricerche Farmacologiche “Mario Negri,”; Milano Italy
| | | | - Pietro La Vitola
- Departement of Neuroscience; IRCCS, Istituto di Ricerche Farmacologiche “Mario Negri,”; Milano Italy
| | - Claudia Balducci
- Departement of Neuroscience; IRCCS, Istituto di Ricerche Farmacologiche “Mario Negri,”; Milano Italy
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37
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Ruzicka J, Kulijewicz-Nawrot M, Rodrigez-Arellano JJ, Jendelova P, Sykova E. Mesenchymal Stem Cells Preserve Working Memory in the 3xTg-AD Mouse Model of Alzheimer's Disease. Int J Mol Sci 2016; 17:ijms17020152. [PMID: 26821012 PMCID: PMC4783886 DOI: 10.3390/ijms17020152] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/12/2016] [Accepted: 01/20/2016] [Indexed: 12/26/2022] Open
Abstract
The transplantation of stem cells may have a therapeutic effect on the pathogenesis and progression of neurodegenerative disorders. In the present study, we transplanted human mesenchymal stem cells (MSCs) into the lateral ventricle of a triple transgenic mouse model of Alzheimer´s disease (3xTg-AD) at the age of eight months. We evaluated spatial reference and working memory after MSC treatment and the possible underlying mechanisms, such as the influence of transplanted MSCs on neurogenesis in the subventricular zone (SVZ) and the expression levels of a 56 kDa oligomer of amyloid β (Aβ*56), glutamine synthetase (GS) and glutamate transporters (Glutamate aspartate transporter (GLAST) and Glutamate transporter-1 (GLT-1)) in the entorhinal and prefrontal cortices and the hippocampus. At 14 months of age we observed the preservation of working memory in MSC-treated 3xTg-AD mice, suggesting that such preservation might be due to the protective effect of MSCs on GS levels and the considerable downregulation of Aβ*56 levels in the entorhinal cortex. These changes were observed six months after transplantation, accompanied by clusters of proliferating cells in the SVZ. Since the grafted cells did not survive for the whole experimental period, it is likely that the observed effects could have been transiently more pronounced at earlier time points than at six months after cell application.
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Affiliation(s)
- Jiri Ruzicka
- Department of Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic.
- Department of Neuroscience, 2nd Faculty of Medicine, Charles University, Prague 150 06, Czech Republic.
| | - Magdalena Kulijewicz-Nawrot
- Department of Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic.
| | - Jose Julio Rodrigez-Arellano
- Department of Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic.
- Functional Neuroanatomy Laboratory, Department of Neuroscience, Faculty of Medicine, the University of the Basque Country, 48940 Leioa, Spain.
| | - Pavla Jendelova
- Department of Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic.
- Department of Neuroscience, 2nd Faculty of Medicine, Charles University, Prague 150 06, Czech Republic.
| | - Eva Sykova
- Department of Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague 142 20, Czech Republic.
- Department of Neuroscience, 2nd Faculty of Medicine, Charles University, Prague 150 06, Czech Republic.
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38
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Haas LT, Salazar SV, Kostylev MA, Um JW, Kaufman AC, Strittmatter SM. Metabotropic glutamate receptor 5 couples cellular prion protein to intracellular signalling in Alzheimer's disease. Brain 2015; 139:526-46. [PMID: 26667279 DOI: 10.1093/brain/awv356] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 10/17/2015] [Indexed: 01/27/2023] Open
Abstract
Alzheimer's disease-related phenotypes in mice can be rescued by blockade of either cellular prion protein or metabotropic glutamate receptor 5. We sought genetic and biochemical evidence that these proteins function cooperatively as an obligate complex in the brain. We show that cellular prion protein associates via transmembrane metabotropic glutamate receptor 5 with the intracellular protein mediators Homer1b/c, calcium/calmodulin-dependent protein kinase II, and the Alzheimer's disease risk gene product protein tyrosine kinase 2 beta. Coupling of cellular prion protein to these intracellular proteins is modified by soluble amyloid-β oligomers, by mouse brain Alzheimer's disease transgenes or by human Alzheimer's disease pathology. Amyloid-β oligomer-triggered phosphorylation of intracellular protein mediators and impairment of synaptic plasticity in vitro requires Prnp-Grm5 genetic interaction, being absent in transheterozygous loss-of-function, but present in either single heterozygote. Importantly, genetic coupling between Prnp and Grm5 is also responsible for signalling, for survival and for synapse loss in Alzheimer's disease transgenic model mice. Thus, the interaction between metabotropic glutamate receptor 5 and cellular prion protein has a central role in Alzheimer's disease pathogenesis, and the complex is a potential target for disease-modifying intervention.
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Affiliation(s)
- Laura T Haas
- 1 Cellular Neuroscience, Neurodegeneration and Repair Program, Department of Neurology, Yale University School of Medicine, New Haven, CT 06536, USA 2 Graduate School of Cellular and Molecular Neuroscience, University of Tuebingen, D-72074 Tuebingen, Germany
| | - Santiago V Salazar
- 1 Cellular Neuroscience, Neurodegeneration and Repair Program, Department of Neurology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Mikhail A Kostylev
- 1 Cellular Neuroscience, Neurodegeneration and Repair Program, Department of Neurology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Ji Won Um
- 1 Cellular Neuroscience, Neurodegeneration and Repair Program, Department of Neurology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Adam C Kaufman
- 1 Cellular Neuroscience, Neurodegeneration and Repair Program, Department of Neurology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Stephen M Strittmatter
- 1 Cellular Neuroscience, Neurodegeneration and Repair Program, Department of Neurology, Yale University School of Medicine, New Haven, CT 06536, USA
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Müller-Schiffmann A, Herring A, Abdel-Hafiz L, Chepkova AN, Schäble S, Wedel D, Horn AHC, Sticht H, de Souza Silva MA, Gottmann K, Sergeeva OA, Huston JP, Keyvani K, Korth C. Amyloid-β dimers in the absence of plaque pathology impair learning and synaptic plasticity. Brain 2015; 139:509-25. [DOI: 10.1093/brain/awv355] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 10/17/2015] [Indexed: 11/12/2022] Open
Abstract
Abstract
Despite amyloid plaques, consisting of insoluble, aggregated amyloid-β peptides, being a defining feature of Alzheimer’s disease, their significance has been challenged due to controversial findings regarding the correlation of cognitive impairment in Alzheimer’s disease with plaque load. The amyloid cascade hypothesis defines soluble amyloid-β oligomers, consisting of multiple amyloid-β monomers, as precursors of insoluble amyloid-β plaques. Dissecting the biological effects of single amyloid-β oligomers, for example of amyloid-β dimers, an abundant amyloid-β oligomer associated with clinical progression of Alzheimer’s disease, has been difficult due to the inability to control the kinetics of amyloid-β multimerization. For investigating the biological effects of amyloid-β dimers, we stabilized amyloid-β dimers by an intermolecular disulphide bridge via a cysteine mutation in the amyloid-β peptide (Aβ-S8C) of the amyloid precursor protein. This construct was expressed as a recombinant protein in cells and in a novel transgenic mouse, termed tgDimer mouse. This mouse formed constant levels of highly synaptotoxic soluble amyloid-β dimers, but not monomers, amyloid-β plaques or insoluble amyloid-β during its lifespan. Accordingly, neither signs of neuroinflammation, tau hyperphosphorylation or cell death were observed. Nevertheless, these tgDimer mice did exhibit deficits in hippocampal long-term potentiation and age-related impairments in learning and memory, similar to what was observed in classical Alzheimer’s disease mouse models. Although the amyloid-β dimers were unable to initiate the formation of insoluble amyloid-β aggregates in tgDimer mice, after crossbreeding tgDimer mice with the CRND8 mouse, an amyloid-β plaque generating mouse model, Aβ-S8C dimers were sequestered into amyloid-β plaques, suggesting that amyloid-β plaques incorporate neurotoxic amyloid-β dimers that by themselves are unable to self-assemble. Our results suggest that within the fine interplay between different amyloid-β species, amyloid-β dimer neurotoxic signalling, in the absence of amyloid-β plaque pathology, may be involved in causing early deficits in synaptic plasticity, learning and memory that accompany Alzheimer’s disease.
10.1093/brain/awv355_video_abstract awv355_video_abstract
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Affiliation(s)
| | - Arne Herring
- 2 Institute of Neuropathology, University of Duisburg-Essen, Germany
| | - Laila Abdel-Hafiz
- 3 Centre for Behavioural Neuroscience, Heinrich Heine University, Düsseldorf, Germany
| | - Aisa N. Chepkova
- 4 Institute for Neuro- and Sensory Physiology, Heinrich Heine University, Düsseldorf, Germany
| | - Sandra Schäble
- 3 Centre for Behavioural Neuroscience, Heinrich Heine University, Düsseldorf, Germany
- *Present address: Comparative Psychology, Institute of Experimental Psychology, Heinrich Heine University, Düsseldorf, Germany
| | - Diana Wedel
- 1 Department Neuropathology, Heinrich Heine University, Düsseldorf, Germany
| | - Anselm H. C. Horn
- 5 Institute for Biochemistry, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Heinrich Sticht
- 5 Institute for Biochemistry, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | | | - Kurt Gottmann
- 4 Institute for Neuro- and Sensory Physiology, Heinrich Heine University, Düsseldorf, Germany
| | - Olga A. Sergeeva
- 4 Institute for Neuro- and Sensory Physiology, Heinrich Heine University, Düsseldorf, Germany
| | - Joseph P. Huston
- 3 Centre for Behavioural Neuroscience, Heinrich Heine University, Düsseldorf, Germany
| | - Kathy Keyvani
- 2 Institute of Neuropathology, University of Duisburg-Essen, Germany
| | - Carsten Korth
- 1 Department Neuropathology, Heinrich Heine University, Düsseldorf, Germany
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40
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Wang SW, Yang SG, Liu W, Zhang YX, Xu PX, Wang T, Ling TJ, Liu RT. Alpha-tocopherol quinine ameliorates spatial memory deficits by reducing beta-amyloid oligomers, neuroinflammation and oxidative stress in transgenic mice with Alzheimer's disease. Behav Brain Res 2015; 296:109-117. [PMID: 26358659 DOI: 10.1016/j.bbr.2015.09.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/31/2015] [Accepted: 09/02/2015] [Indexed: 11/18/2022]
Abstract
The pathologies of Alzheimer's disease (AD) is associated with soluble beta-amyloid (Aβ) oligomers, neuroinflammation and oxidative stress. Decreasing the levels of Aβ oligomer, glial activation and oxidative stress are potential therapeutic approaches for AD treatment. We previously found alpha-tocopherol quinine (α-TQ) inhibited Aβ aggregation and cytotoxicity, decreased the release of inflammatory cytokines and reactive oxygen species (ROS) in vitro. However, whether α-TQ ameliorates memory deficits and other neuropathologies in mice or patients with AD remains unknown. In this study, we reported that orally administered α-TQ ameliorated memory impairment in APPswe/PS1dE9 transgenic mice, decreased oxidative stress and the levels of Aβ oligomer in the brains of mice, prevented the production of inducible nitric oxide synthase and inflammatory mediators, such as interleukin-6 and interleukin-1β, and inhibited microglial activation by inhibiting NF-κB signaling pathway. These findings suggest that α-TQ has potential therapeutic value for AD treatment.
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Affiliation(s)
- Shao-Wei Wang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Shi-Gao Yang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Wen Liu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Yang-Xin Zhang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Peng-Xin Xu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Life Science, Ningxia University, Yinchuan 750021, China
| | - Teng Wang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Tie-Jun Ling
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China.
| | - Rui-Tian Liu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
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41
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Giuffrida ML, Tomasello MF, Pandini G, Caraci F, Battaglia G, Busceti C, Di Pietro P, Pappalardo G, Attanasio F, Chiechio S, Bagnoli S, Nacmias B, Sorbi S, Vigneri R, Rizzarelli E, Nicoletti F, Copani A. Monomeric ß-amyloid interacts with type-1 insulin-like growth factor receptors to provide energy supply to neurons. Front Cell Neurosci 2015; 9:297. [PMID: 26300732 PMCID: PMC4528168 DOI: 10.3389/fncel.2015.00297] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 07/20/2015] [Indexed: 12/12/2022] Open
Abstract
ß-amyloid (Aß1−42) is produced by proteolytic cleavage of the transmembrane type-1 protein, amyloid precursor protein. Under pathological conditions, Aß1−42self-aggregates into oligomers, which cause synaptic dysfunction and neuronal loss, and are considered the culprit of Alzheimer's disease (AD). However, Aß1−42 is mainly monomeric at physiological concentrations, and the precise role of monomeric Aß1−42 in neuronal function is largely unknown. We report that the monomer of Aß1−42 activates type-1 insulin-like growth factor receptors and enhances glucose uptake in neurons and peripheral cells by promoting the translocation of the Glut3 glucose transporter from the cytosol to the plasma membrane. In neurons, activity-dependent glucose uptake was blunted after blocking endogenous Aß production, and re-established in the presence of cerebrospinal fluid Aß. APP-null neurons failed to enhance depolarization-stimulated glucose uptake unless exogenous monomeric Aß1−42 was added. These data suggest that Aß1−42 monomers were critical for maintaining neuronal glucose homeostasis. Accordingly, exogenous Aß1−42 monomers were able to rescue the low levels of glucose consumption observed in brain slices from AD mutant mice.
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Affiliation(s)
- Maria L Giuffrida
- National Research Council, Institute of Biostructure and Bioimaging Catania, Italy
| | - Marianna F Tomasello
- National Research Council, Institute of Biostructure and Bioimaging Catania, Italy ; PhD Program in Neuropharmacology, University of Catania Catania, Italy
| | - Giuseppe Pandini
- National Research Council, Institute of Biostructure and Bioimaging Catania, Italy ; Department of Clinical and Molecular Biomedicine, University of Catania Catania, Italy
| | - Filippo Caraci
- Department of Drug Sciences, University of Catania Catania, Italy ; IRCCS Associazione Oasi Maria S.S., Institute for Research on Mental Retardation and Brain Aging Troina, Italy
| | - Giuseppe Battaglia
- Department of Molecular Pathology, Neuropharmacology Unit, IRCCS Neuromed Pozzilli, Italy
| | - Carla Busceti
- Department of Molecular Pathology, Neuropharmacology Unit, IRCCS Neuromed Pozzilli, Italy
| | - Paola Di Pietro
- Department of Molecular Pathology, Neuropharmacology Unit, IRCCS Neuromed Pozzilli, Italy
| | - Giuseppe Pappalardo
- National Research Council, Institute of Biostructure and Bioimaging Catania, Italy
| | - Francesco Attanasio
- National Research Council, Institute of Biostructure and Bioimaging Catania, Italy
| | - Santina Chiechio
- Department of Drug Sciences, University of Catania Catania, Italy
| | | | | | - Sandro Sorbi
- NEUROFARBA, University of Florence Florence, Italy
| | - Riccardo Vigneri
- National Research Council, Institute of Biostructure and Bioimaging Catania, Italy ; Department of Clinical and Molecular Biomedicine, University of Catania Catania, Italy
| | - Enrico Rizzarelli
- National Research Council, Institute of Biostructure and Bioimaging Catania, Italy
| | - Ferdinando Nicoletti
- Department of Molecular Pathology, Neuropharmacology Unit, IRCCS Neuromed Pozzilli, Italy ; Department of Human Physiology and Pharmacology, University "La Sapienza" Rome, Italy
| | - Agata Copani
- National Research Council, Institute of Biostructure and Bioimaging Catania, Italy ; Department of Drug Sciences, University of Catania Catania, Italy
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42
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Breydo L, Uversky VN. Structural, morphological, and functional diversity of amyloid oligomers. FEBS Lett 2015; 589:2640-8. [PMID: 26188543 DOI: 10.1016/j.febslet.2015.07.013] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 07/08/2015] [Accepted: 07/11/2015] [Indexed: 12/19/2022]
Abstract
Protein misfolding and aggregation are known to play a crucial role in a number of important human diseases (Alzheimer's, Parkinson's, prion, diabetes, cataracts, etc.) as well as in a multitude of physiological processes. Protein aggregation is a highly complex process resulting in a variety of aggregates with different structures and morphologies. Oligomeric protein aggregates (amyloid oligomers) are formed as both intermediates and final products of the aggregation process. They are believed to play an important role in many protein aggregation-related diseases, and many of them are highly cytotoxic. Due to their instability and structural heterogeneity, information about structure, mechanism of formation, and physiological effects of amyloid oligomers is sparse. This review attempts to summarize the existing information on the major properties of amyloid oligomers.
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Affiliation(s)
- Leonid Breydo
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; Institute for Biological Instrumentation, Russian Academy of Sciences, Pushchino, Moscow Region, Russian Federation; Department of Biology, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia.
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43
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Kotler SA, Brender JR, Vivekanandan S, Suzuki Y, Yamamoto K, Monette M, Krishnamoorthy J, Walsh P, Cauble M, Holl MMB, Marsh ENG, Ramamoorthy A. High-resolution NMR characterization of low abundance oligomers of amyloid-β without purification. Sci Rep 2015; 5:11811. [PMID: 26138908 PMCID: PMC4490348 DOI: 10.1038/srep11811] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 05/21/2015] [Indexed: 01/30/2023] Open
Abstract
Alzheimer's disease is characterized by the misfolding and self-assembly of the amyloidogenic protein amyloid-β (Aβ). The aggregation of Aβ leads to diverse oligomeric states, each of which may be potential targets for intervention. Obtaining insight into Aβ oligomers at the atomic level has been a major challenge to most techniques. Here, we use magic angle spinning recoupling (1)H-(1)H NMR experiments to overcome many of these limitations. Using (1)H-(1)H dipolar couplings as a NMR spectral filter to remove both high and low molecular weight species, we provide atomic-level characterization of a non-fibrillar aggregation product of the Aβ1-40 peptide using non-frozen samples without isotopic labeling. Importantly, this spectral filter allows the detection of the specific oligomer signal without a separate purification procedure. In comparison to other solid-state NMR techniques, the experiment is extraordinarily selective and sensitive. A resolved 2D spectra could be acquired of a small population of oligomers (6 micrograms, 7% of the total) amongst a much larger population of monomers and fibers (93% of the total). By coupling real-time (1)H-(1)H NMR experiments with other biophysical measurements, we show that a stable, primarily disordered Aβ1-40 oligomer 5-15 nm in diameter can form and coexist in parallel with the well-known cross-β-sheet fibrils.
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Affiliation(s)
- Samuel A. Kotler
- Biophysics, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
| | - Jeffrey R. Brender
- Biophysics, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
- Department of Chemistry, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
| | | | - Yuta Suzuki
- Department of Chemistry, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
| | - Kazutoshi Yamamoto
- Biophysics, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
- Department of Chemistry, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
| | - Martine Monette
- Bruker BioSpin Ltd., Bruker Corporation, 555 E Steeles Ave, Milton, ON, Canada
| | - Janarthanan Krishnamoorthy
- Biophysics, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
- Department of Chemistry, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
| | - Patrick Walsh
- Biophysics, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
- Department of Chemistry, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
| | - Meagan Cauble
- Department of Chemistry, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
| | - Mark M. Banaszak Holl
- Department of Chemistry, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
- Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
| | - E. Neil. G. Marsh
- Department of Chemistry, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
| | - Ayyalusamy Ramamoorthy
- Biophysics, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
- Department of Chemistry, University of Michigan-Ann Arbor, Ann Arbor, Michigan 48109, U.S.A
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44
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Tau immunotherapy modulates both pathological tau and upstream amyloid pathology in an Alzheimer's disease mouse model. J Neurosci 2015; 35:4857-68. [PMID: 25810517 DOI: 10.1523/jneurosci.4989-14.2015] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In Alzheimer's disease (AD), the pathological accumulation of tau appears to be a downstream effect of amyloid β protein (Aβ). However, the relationship between these two proteins and memory loss is unclear. In this study, we evaluated the specific removal of pathological tau oligomers in aged Tg2576 mice by passive immunotherapy using tau oligomer-specific monoclonal antibody. Removal of tau oligomers reversed memory deficits and accelerated plaque deposition in the brain. Surprisingly, Aβ*56 levels decreased, suggesting a link between tau and Aβ oligomers in the promotion of cognitive decline. The results suggest that tau oligomerization is not only a consequence of Aβ pathology but also a critical mediator of the toxic effects observed afterward in AD. Overall, these findings support the potential of tau oligomers as a therapeutic target for AD.
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45
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Liu P, Reed MN, Kotilinek LA, Grant MKO, Forster CL, Qiang W, Shapiro SL, Reichl JH, Chiang ACA, Jankowsky JL, Wilmot CM, Cleary JP, Zahs KR, Ashe KH. Quaternary Structure Defines a Large Class of Amyloid-β Oligomers Neutralized by Sequestration. Cell Rep 2015; 11:1760-71. [PMID: 26051935 DOI: 10.1016/j.celrep.2015.05.021] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/04/2015] [Accepted: 05/10/2015] [Indexed: 12/29/2022] Open
Abstract
The accumulation of amyloid-β (Aβ) as amyloid fibrils and toxic oligomers is an important step in the development of Alzheimer's disease (AD). However, there are numerous potentially toxic oligomers and little is known about their neurological effects when generated in the living brain. Here we show that Aβ oligomers can be assigned to one of at least two classes (type 1 and type 2) based on their temporal, spatial, and structural relationships to amyloid fibrils. The type 2 oligomers are related to amyloid fibrils and represent the majority of oligomers generated in vivo, but they remain confined to the vicinity of amyloid plaques and do not impair cognition at levels relevant to AD. Type 1 oligomers are unrelated to amyloid fibrils and may have greater potential to cause global neural dysfunction in AD because they are dispersed. These results refine our understanding of the pathogenicity of Aβ oligomers in vivo.
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Affiliation(s)
- Peng Liu
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA; N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55455, USA
| | - Miranda N Reed
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA; N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55455, USA
| | - Linda A Kotilinek
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA; N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55455, USA
| | - Marianne K O Grant
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA; N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55455, USA
| | - Colleen L Forster
- N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55455, USA; UMN Academic Health Center Biological Materials Procurement Network, University of Minnesota, Minneapolis, MN 55455, USA
| | - Wei Qiang
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA
| | - Samantha L Shapiro
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA; N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55455, USA
| | - John H Reichl
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA; N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55455, USA
| | - Angie C A Chiang
- Departments of Neuroscience, Neurology and Neurosurgery, Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Joanna L Jankowsky
- Departments of Neuroscience, Neurology and Neurosurgery, Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Carrie M Wilmot
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - James P Cleary
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA; N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55455, USA; Geriatric Research, Education and Clinical Center (GRECC), VA Medical Center, Minneapolis, MN 55417, USA
| | - Kathleen R Zahs
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA; N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55455, USA
| | - Karen H Ashe
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA; N. Bud Grossman Center for Memory Research and Care, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Geriatric Research, Education and Clinical Center (GRECC), VA Medical Center, Minneapolis, MN 55417, USA.
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46
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Involvement of Intracellular and Mitochondrial Aβ in the Ameliorative Effects of Huperzine A against Oligomeric Aβ42-Induced Injury in Primary Rat Neurons. PLoS One 2015; 10:e0128366. [PMID: 26024517 PMCID: PMC4448999 DOI: 10.1371/journal.pone.0128366] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 04/26/2015] [Indexed: 12/18/2022] Open
Abstract
Considerable studies indicate huperzine A is a promising natural product to suppress neuronal damages induced by β-amyloid (Aβ), a key pathogenic event in the Alzheimer’s disease (AD). As an extension, the present study for the first time explored whether the beneficial profiles of huperzine A against oligomeric Aβ42 induced neurotoxicity are associated with the accumulation and detrimental function of intraneuronal/mitochondrial Aβ, on the basis of the emerging evidence that intracellular Aβ is more relevant to AD progression as compared with extracellular Aβ. Huperzine A treatment was shown to significantly attenuate the neurotoxicity of oligomeric Aβ42, as demonstrated by increased neuronal viability. Interestingly, our results proved that exogenous Aβ42 could accumulate intraneuronally in a dose- and time-dependent manner, while huperzine A treatment markedly reduced the level of intracellular Aβ42. Moreover, huperzine A treatment rescued mitochondrial dysfunction induced by oligomeric Aβ42, including adenosine triphosphate (ATP) reduction, reactive oxygen species (ROS) overproduction and membrane potential depolarization. Further study demonstrated that huperzine A also significantly reduced the level of Aβ42 in the mitochondria-enriched subcellular fractions, as well as the Aβ42 fluorescent signals colocalized with mitochondrial marker. This study indicates that interfering intracellular Aβ especially mitochondrial Aβ accumulation, together with ameliorating Aβ-associated mitochondrial dysfunction, may contribute to the protective effects of huperzine A against Aβ neurotoxicity. Above results may shed more light on the pharmacological mechanisms of huperzine A and provide important clues for discovering novel therapeutic strategies for AD.
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O'Hare E, Jeggo R, Kim EM, Barbour B, Walczak JS, Palmer P, Lyons T, Page D, Hanna D, Meara JR, Spanswick D, Guo JP, McGeer EG, McGeer PL, Hobson P. Lack of support for bexarotene as a treatment for Alzheimer's disease. Neuropharmacology 2015; 100:124-30. [PMID: 26025659 DOI: 10.1016/j.neuropharm.2015.04.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/22/2015] [Indexed: 12/16/2022]
Abstract
Bexarotene has been reported to reduce brain amyloid-β (Aβ) levels and to improve cognitive function in transgenic mouse models of Alzheimer's disease (AD). Four groups failed to fully replicate the primary results but the original authors claimed overall support for the general conclusions. Because of its potential clinical importance, the current work studied the effects of bexarotene using two animal species and highly relevant paradigms. Rats were tested for the ability of bexarotene to prevent changes induced by an Aβ challenge in the form intracerebroventricular (i.c.v) administration of 7PA2 conditioned medium (7PA2 CM) which contains high levels of Aβ species. Bexarotene had no effect on the long-term potentiation of evoked extracellular field excitatory postsynaptic potentials induced by i.c.v. 7PA2 CM. It also had no effect following subcutaneous administration of 2, 5, 10 and 15 mg/kg on behavioral/cognitive impairment using an alternating-lever cyclic-ratio schedule of operant responding in the rat. The effects of bexarotene were further tested using the APPSwFILon, PSEN1*M146L*L286V transgenic mouse model of AD, starting at the time Aβ deposits first begin to develop. Mice were sacrificed after 48 days of exposure to 100 mg bexarotene per day. No significant difference between test and control mice was found using a water-maze test, and no significant difference in the number of Aβ deposits in cerebral cortex, using two different antibodies, was apparent. These results question the potential efficacy of bexarotene for AD treatment, even if instigated in the preclinical period prior to the onset of cognitive deficits reported for human AD. This article is part of the Special Issue entitled 'Synaptopathy--from Biology to Therapy'.
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Affiliation(s)
- Eugene O'Hare
- School of Psychology, Queen's University, University Road, Belfast BT7 1NN, Northern Ireland, UK.
| | - Ross Jeggo
- Neurosolutions Limited, P.O. Box 3517, Coventry CV4 7ZS, UK.
| | - Eun-Mee Kim
- School of Psychology, University of Ulster, Cromore Road, Coleraine BT52 1SA, UK.
| | - Bridgeen Barbour
- School of Psychology, Queen's University, University Road, Belfast BT7 1NN, Northern Ireland, UK.
| | | | - Philip Palmer
- School of Psychology, Queen's University, University Road, Belfast BT7 1NN, Northern Ireland, UK.
| | - Taylor Lyons
- School of Psychology, Queen's University, University Road, Belfast BT7 1NN, Northern Ireland, UK.
| | - Deaglan Page
- School of Psychology, Queen's University, University Road, Belfast BT7 1NN, Northern Ireland, UK.
| | - Donncha Hanna
- School of Psychology, Queen's University, University Road, Belfast BT7 1NN, Northern Ireland, UK.
| | - Jolyon R Meara
- Institute of Primary Care and Public Health, Cardiff University CF10 3XQ, UK.
| | - David Spanswick
- Neurosolutions Limited, P.O. Box 3517, Coventry CV4 7ZS, UK; Cerebrasol Limited, P.O. Box 63534, Montreal Quebec H3W1JO, Canada; Department of Physiology, Monash University, Clayton VIC 3800, Australia.
| | - Jian-Ping Guo
- Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver V6T1Z3, BC, Canada
| | - Edith G McGeer
- Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver V6T1Z3, BC, Canada
| | - Patrick L McGeer
- Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver V6T1Z3, BC, Canada.
| | - Peter Hobson
- Institute of Primary Care and Public Health, Cardiff University CF10 3XQ, UK.
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Ferreira ST, Lourenco MV, Oliveira MM, De Felice FG. Soluble amyloid-β oligomers as synaptotoxins leading to cognitive impairment in Alzheimer's disease. Front Cell Neurosci 2015; 9:191. [PMID: 26074767 PMCID: PMC4443025 DOI: 10.3389/fncel.2015.00191] [Citation(s) in RCA: 236] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 04/30/2015] [Indexed: 12/22/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia in the elderly, and affects millions of people worldwide. As the number of AD cases continues to increase in both developed and developing countries, finding therapies that effectively halt or reverse disease progression constitutes a major research and public health challenge. Since the identification of the amyloid-β peptide (Aβ) as the major component of the amyloid plaques that are characteristically found in AD brains, a major effort has aimed to determine whether and how Aβ leads to memory loss and cognitive impairment. A large body of evidence accumulated in the past 15 years supports a pivotal role of soluble Aβ oligomers (AβOs) in synapse failure and neuronal dysfunction in AD. Nonetheless, a number of basic questions, including the exact molecular composition of the synaptotoxic oligomers, the identity of the receptor(s) to which they bind, and the signaling pathways that ultimately lead to synapse failure, remain to be definitively answered. Here, we discuss recent advances that have illuminated our understanding of the chemical nature of the toxic species and the deleterious impact they have on synapses, and have culminated in the proposal of an Aβ oligomer hypothesis for Alzheimer’s pathogenesis. We also highlight outstanding questions and challenges in AD research that should be addressed to allow translation of research findings into effective AD therapies.
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Affiliation(s)
- Sergio T Ferreira
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil ; Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil
| | - Mychael V Lourenco
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil
| | - Mauricio M Oliveira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil
| | - Fernanda G De Felice
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil
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Mandler M, Santic R, Gruber P, Cinar Y, Pichler D, Funke SA, Willbold D, Schneeberger A, Schmidt W, Mattner F. Tailoring the antibody response to aggregated Aß using novel Alzheimer-vaccines. PLoS One 2015; 10:e0115237. [PMID: 25611858 PMCID: PMC4303436 DOI: 10.1371/journal.pone.0115237] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 11/20/2014] [Indexed: 12/26/2022] Open
Abstract
Recent evidence suggests Alzheimer-Disease (AD) to be driven by aggregated Aß. Capitalizing on the mechanism of molecular mimicry and applying several selection layers, we screened peptide libraries for moieties inducing antibodies selectively reacting with Aß-aggregates. The technology identified a pool of peptide candidates; two, AFFITOPES AD01 and AD02, were assessed as vaccination antigens and compared to Aβ1-6, the targeted epitope. When conjugated to Keyhole Limpet Hemocyanin (KLH) and adjuvanted with aluminum, all three peptides induced Aß-targeting antibodies (Abs). In contrast to Aß1-6, AD01- or AD02-induced Abs were characterized by selectivity for aggregated forms of Aß and absence of reactivity with related molecules such as Amyloid Precursor Protein (APP)/ secreted APP-alpha (sAPPa). Administration of AFFITOPE-vaccines to APP-transgenic mice was found to reduce their cerebral amyloid burden, the associated neuropathological alterations and to improve their cognitive functions. Thus, the AFFITOME-technology delivers vaccines capable of inducing a distinct Ab response. Their features may be beneficial to AD-patients, a hypothesis currently tested within a phase-II-study.
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Affiliation(s)
- Markus Mandler
- AFFiRiS AG, Karl-Farkas-Gasse 22, A-1030, Vienna, Austria
| | - Radmila Santic
- AFFiRiS AG, Karl-Farkas-Gasse 22, A-1030, Vienna, Austria
| | - Petra Gruber
- AFFiRiS AG, Karl-Farkas-Gasse 22, A-1030, Vienna, Austria
| | - Yeliz Cinar
- Institute for Structural Biochemistry (Institute of Complex Systems 6), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Dagmar Pichler
- AFFiRiS AG, Karl-Farkas-Gasse 22, A-1030, Vienna, Austria
| | - Susanne Aileen Funke
- Institute for Structural Biochemistry (Institute of Complex Systems 6), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Dieter Willbold
- Institute for Structural Biochemistry (Institute of Complex Systems 6), Forschungszentrum Jülich, 52425, Jülich, Germany
| | | | - Walter Schmidt
- AFFiRiS AG, Karl-Farkas-Gasse 22, A-1030, Vienna, Austria
| | - Frank Mattner
- AFFiRiS AG, Karl-Farkas-Gasse 22, A-1030, Vienna, Austria
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Lipids in Amyloid-β Processing, Aggregation, and Toxicity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 855:67-94. [PMID: 26149926 DOI: 10.1007/978-3-319-17344-3_3] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aggregation of amyloid-beta (Aβ) peptide is the major event underlying neuronal damage in Alzheimer's disease (AD). Specific lipids and their homeostasis play important roles in this and other neurodegenerative disorders. The complex interplay between the lipids and the generation, clearance or deposition of Aβ has been intensively investigated and is reviewed in this chapter. Membrane lipids can have an important influence on the biogenesis of Aβ from its precursor protein. In particular, increased cholesterol in the plasma membrane augments Aβ generation and shows a strong positive correlation with AD progression. Furthermore, apolipoprotein E, which transports cholesterol in the cerebrospinal fluid and is known to interact with Aβ or compete with it for the lipoprotein receptor binding, significantly influences Aβ clearance in an isoform-specific manner and is the major genetic risk factor for AD. Aβ is an amphiphilic peptide that interacts with various lipids, proteins and their assemblies, which can lead to variation in Aβ aggregation in vitro and in vivo. Upon interaction with the lipid raft components, such as cholesterol, gangliosides and phospholipids, Aβ can aggregate on the cell membrane and thereby disrupt it, perhaps by forming channel-like pores. This leads to perturbed cellular calcium homeostasis, suggesting that Aβ-lipid interactions at the cell membrane probably trigger the neurotoxic cascade in AD. Here, we overview the roles of specific lipids, lipid assemblies and apolipoprotein E in Aβ processing, clearance and aggregation, and discuss the contribution of these factors to the neurotoxicity in AD.
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