101
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Paraschiv G, Vincke C, Czaplewska P, Manea M, Muyldermans S, Przybylski M. Epitope structure and binding affinity of single chain llama anti-β-amyloid antibodies revealed by proteolytic excision affinity-mass spectrometry. J Mol Recognit 2012; 26:1-9. [DOI: 10.1002/jmr.2210] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 06/13/2012] [Accepted: 06/20/2012] [Indexed: 01/03/2023]
Affiliation(s)
- Gabriela Paraschiv
- Department of Chemistry, Laboratory of Analytical Chemistry and Biopolymer Structure Analysis; University of Konstanz; 78457; Konstanz; Germany
| | | | | | | | | | - Michael Przybylski
- Department of Chemistry, Laboratory of Analytical Chemistry and Biopolymer Structure Analysis; University of Konstanz; 78457; Konstanz; Germany
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102
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Antosova A, Gazova Z, Fedunova D, Valusova E, Bystrenova E, Valle F, Daxnerova Z, Biscarini F, Antalik M. Anti-amyloidogenic activity of glutathione-covered gold nanoparticles. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2012. [DOI: 10.1016/j.msec.2012.07.036] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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103
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Inestrosa NC, Montecinos-Oliva C, Fuenzalida M. Wnt signaling: role in Alzheimer disease and schizophrenia. J Neuroimmune Pharmacol 2012; 7:788-807. [PMID: 23160851 DOI: 10.1007/s11481-012-9417-5] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/30/2012] [Indexed: 12/16/2022]
Abstract
Wnt signaling function starts during the development of the nervous system and is crucial for synaptic plasticity in the adult brain. Clearly Wnt effects in synaptic and plastic processes are relevant, however the implication of this pathway in the prevention of neurodegenerative diseases that produce synaptic impairment, is even more interesting. Several years ago our laboratory found a relationship between the loss of Wnt signaling and the neurotoxicity of the amyloid-β-peptide (Aβ), one of the main players in Alzheimer's disease (AD). Moreover, the activation of the Wnt signaling cascade prevents Aβ-dependent cytotoxic effects. In fact, disrupted Wnt signaling may be a direct link between Aβ-toxicity and tau hyperphosphorylation, ultimately leading to impaired synaptic plasticity and/or neuronal degeneration, indicating that a single pathway can account for both neuro-pathological lesions and altered synaptic function. These observations, suggest that a sustained loss of Wnt signaling function may be a key relevant factor in the pathology of AD. On the other hand, Schizophrenia remains one of the most debilitating and intractable illness in psychiatry. Since Wnt signaling is important in organizing the developing brain, it is reasonable to propose that defects in Wnt signaling could contribute to Schizophrenia, particularly since the neuro-developmental hypothesis of the disease implies subtle dys-regulation of brain development, including some core components of the Wnt signaling pathways such as GSK-3β or Disrupted in Schizophrenia-1 (DISC-1). This review focuses on the relationship between Wnt signaling and its potential relevance for the treatment of neurodegenerative and neuropsychiatric diseases including AD and Schizophrenia.
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Affiliation(s)
- Nibaldo C Inestrosa
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331150, Santiago, Chile.
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104
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Prangkio P, Yusko EC, Sept D, Yang J, Mayer M. Multivariate analyses of amyloid-beta oligomer populations indicate a connection between pore formation and cytotoxicity. PLoS One 2012; 7:e47261. [PMID: 23077580 PMCID: PMC3471831 DOI: 10.1371/journal.pone.0047261] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 09/07/2012] [Indexed: 11/18/2022] Open
Abstract
Aggregates of amyloid-beta (Aβ) peptides are thought to be involved in the development of Alzheimer's disease because they can change synaptic plasticity and induce neuronal cell death by inflammation, oxidative damage, and transmembrane pore formation. Exactly which oligomeric species underlie these cytotoxic effects remains unclear. The work presented here established well-controlled aggregation conditions of Aβ₁₋₄₀ or Aβ₁₋₄₂ peptides over a 20-day period and characterized these preparations with regard to their β-sheet content, degree of fibril formation, relative abundance of various oligomer sizes, and propensity to induce membrane pore formation and cytotoxicity. Using this multivariate data set, a systematic and inherently unbiased partial least squares (PLS) approach showed that for both peptides the abundance of oligomers in the tetramer to 13-mer range contributed positively to both pore formation and cytotoxicity, while monomers, dimers, trimers, and the largest oligomers (>210 kDa) were negatively correlated to both phenomena. Multivariate PLS analysis is ideally suited to handle complex data sets and interdependent variables such as relative oligomer concentrations, making it possible to elucidate structure function relationships in complex mixtures. This approach, therefore, introduces an enabling tool to the field of amyloid research, in which it is often difficult to interpret the activity of individual species within a complex mixture of bioactive species.
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Affiliation(s)
- Panchika Prangkio
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
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105
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Nieznanski K, Choi JK, Chen S, Surewicz K, Surewicz WK. Soluble prion protein inhibits amyloid-β (Aβ) fibrillization and toxicity. J Biol Chem 2012; 287:33104-8. [PMID: 22915585 DOI: 10.1074/jbc.c112.400614] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The pathogenesis of Alzheimer disease appears to be strongly linked to the aggregation of amyloid-β (Aβ) peptide and, especially, formation of soluble Aβ1-42 oligomers. It was recently demonstrated that the cellular prion protein, PrP(C), binds with high affinity to these oligomers, acting as a putative receptor that mediates at least some of their neurotoxic effects. Here we show that the soluble (i.e. glycophosphatidylinositol anchor-free) prion protein and its N-terminal fragment have a strong effect on the aggregation pathway of Aβ1-42, inhibiting its assembly into amyloid fibrils. Furthermore, the prion protein prevents formation of spherical oligomers that normally occur during Aβ fibrillogenesis, acting as a potent inhibitor of Aβ1-42 toxicity as assessed in experiments with neuronal cell culture. These findings may provide a molecular level foundation to explain the reported protective action of the physiologically released N-terminal N1 fragment of PrP(C) against Aβ neurotoxicity. They also suggest a novel approach to pharmacological intervention in Alzheimer disease.
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Affiliation(s)
- Krzysztof Nieznanski
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, USA
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106
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Jellinger KA. Interaction between pathogenic proteins in neurodegenerative disorders. J Cell Mol Med 2012; 16:1166-83. [PMID: 22176890 PMCID: PMC3823071 DOI: 10.1111/j.1582-4934.2011.01507.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 12/16/2011] [Indexed: 12/21/2022] Open
Abstract
The misfolding and progressive aggregation of specific proteins in selective regions of the nervous system is a seminal occurrence in many neurodegenerative disorders, and the interaction between pathological/toxic proteins to cause neurodegeneration is a hot topic of current neuroscience research. Despite clinical, genetic and experimental differences, increasing evidence indicates considerable overlap between synucleinopathies, tauopathies and other protein-misfolding diseases. Inclusions, often characteristic hallmarks of these disorders, suggest interactions of pathological proteins enganging common downstream pathways. Novel findings that have shifted our understanding in the role of pathologic proteins in the pathogenesis of Alzheimer, Parkinson, Huntington and prion diseases, have confirmed correlations/overlaps between these and other neurodegenerative disorders. Emerging evidence, in addition to synergistic effects of tau protein, amyloid-β, α-synuclein and other pathologic proteins, suggests that prion-like induction and spreading, involving secreted proteins, are major pathogenic mechanisms in various neurodegenerative diseases, depending on genetic backgrounds and environmental factors. The elucidation of the basic molecular mechanisms underlying the interaction and spreading of pathogenic proteins, suggesting a dualism or triad of neurodegeneration in protein-misfolding disorders, is a major challenge for modern neuroscience, to provide a deeper insight into their pathogenesis as a basis of effective diagnosis and treatment.
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107
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Mufamadi MS, Choonara YE, Kumar P, Modi G, Naidoo D, Ndesendo VMK, du Toit LC, Iyuke SE, Pillay V. Surface-Engineered Nanoliposomes by Chelating Ligands for Modulating the Neurotoxicity Associated with β-Amyloid Aggregates of Alzheimer’s disease. Pharm Res 2012; 29:3075-89. [DOI: 10.1007/s11095-012-0770-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 04/30/2012] [Indexed: 11/28/2022]
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108
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Wang Q, Xu Y, Chen JC, Qin YY, Liu M, Liu Y, Xie MJ, Yu ZY, Zhu Z, Wang W. Stromal cell-derived factor 1α decreases β-amyloid deposition in Alzheimer's disease mouse model. Brain Res 2012; 1459:15-26. [PMID: 22560596 DOI: 10.1016/j.brainres.2012.04.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 03/21/2012] [Accepted: 04/07/2012] [Indexed: 12/17/2022]
Abstract
β-amyloid (Aβ) aggregates are known to induce neuronal and synaptic dysfunction, and thus are involved in learning and memory deficits in Alzheimer's disease (AD), making Aβ deposits a potential target for prevention or treatment. Microglia, especially bone marrow-derived microglia (BMDM), has been recently thought to play important roles in internalizing and phagocytozing Aβ. BMDM originate in the bone marrow, migrate into the blood as hematopoietic progenitor cells (HPCs) and enter the brain in a chemokine-dependent manner. An effective chemoattractant for HPCs is stromal cell-derived factor 1 (SDF-1), which is also involved in regulating HPCs differentiation. Therefore, we hypothesize that SDF-1 might have influence on the migration of BMDM from peripheral cycle to brain. To explore whether treatment with SDF-1α can decrease Aβ burden, APP/PS1 double transgenic mice were given intracerebroventricular injection of SDF-1α weekly from the age of 28 to 32 weeks (4 weeks of injections) or from 28 to 36 weeks (8 weeks of injections). The results of our study showed that SDF-1α treatment decreased the area and the number of Aβ deposits, increased the level of Iba-1, a marker of microglia, and increased the number of plaque associated microglia in the parenchyma of APP/PS1 transgenic mice. These results suggest that SDF-1 could provide a novel and promising target for the purpose of lowering Aβ pathology in AD.
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Affiliation(s)
- Qi Wang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Avenue, Wuhan, China
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109
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Wise-Scira O, Xu L, Kitahara T, Perry G, Coskuner O. Amyloid-β peptide structure in aqueous solution varies with fragment size. J Chem Phys 2012; 135:205101. [PMID: 22128957 DOI: 10.1063/1.3662490] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Various fragment sizes of the amyloid-β (Aβ) peptide have been utilized to mimic the properties of the full-length Aβ peptide in solution. Among these smaller fragments, Aβ16 and Aβ28 have been investigated extensively. In this work, we report the structural and thermodynamic properties of the Aβ16, Aβ28, and Aβ42 peptides in an aqueous solution environment. We performed replica exchange molecular dynamics simulations along with thermodynamic calculations for investigating the conformational free energies, secondary and tertiary structures of the Aβ16, Aβ28, and Aβ42 peptides. The results show that the thermodynamic properties vary from each other for these peptides. Furthermore, the secondary structures in the Asp1-Lys16 and Asp1-Lys28 regions of Aβ42 cannot be completely captured by the Aβ16 and Aβ28 fragments. For example, the β-sheet structures in the N-terminal region of Aβ16 and Aβ28 are either not present or the abundance is significantly decreased in Aβ42. The α-helix and β-sheet abundances in Aβ28 and Aβ42 show trends--to some extent--with the potential of mean forces but no such trend could be obtained for Aβ16. Interestingly, Arg5 forms salt bridges with large abundances in all three peptides. The formation of a salt bridge between Asp23-Lys28 is more preferred over the Glu22-Lys28 salt bridge in Aβ28 but this trend is vice versa for Aβ42. This study shows that the Asp1-Lys16 and Asp1-Lys28 regions of the full length Aβ42 peptide cannot be completely mimicked by studying the Aβ16 and Aβ28 peptides.
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Affiliation(s)
- Olivia Wise-Scira
- The University of Texas at San Antonio, Department of Chemistry, One UTSA Circle, San Antonio, Texas 78249, USA
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110
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Xing SL, Chen B, Shen DZ, Zhu CQ. β-amyloid peptide binds and regulates ectopic ATP synthase α-chain on neural surface. Int J Neurosci 2012; 122:290-7. [PMID: 22185089 DOI: 10.3109/00207454.2011.649867] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Accumulation of the amyloid β protein (Aβ) in the brain is an important step in the pathogenesis of Alzheimer's disease. Many molecules could bind with Aβ, among which some molecules mediate Aβ neuronal toxicity. Thus, it is of interest to study the binding proteins of Aβ, and the functions that might be affected by Aβ. In the present study, we observed that accumulation of α-subunit of ATP synthase is associated with aggregates of Aβ proteins in amyloid plaques of amyloid precursor protein/presennillin-1 transgenic mice, and identified the α-subunit of ATP synthase as one of the Aβ binding proteins on the plasma membrane of neural cells by Western blot and mass spectrometry. In order to evaluate the consequences of the interaction between Aβ and surface α-subunit of ATP synthase, the extracellular ATP generation was analyzed, which showed that aggregated Aβ partially inhibited the extracellular generation of ATP, but was unable to significantly induce a decrease in cell surface ATP synthase α on neurons. These results suggest that the cell surface ATP synthase α is a binding protein for Aβ on neural cells, the functional inhibition of surface ATP synthase might be involved in machinery of brain malfunction in Aβ-mediated pathogenesis of Alzheimer's disease.
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Affiliation(s)
- San-Li Xing
- Shanghai Geriatric Institute of Chinese Medicine, Shanghai 200031, PR China
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111
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Nomura I, Takechi H, Kato N. Intraneuronally injected amyloid β inhibits long-term potentiation in rat hippocampal slices. J Neurophysiol 2012; 107:2526-31. [PMID: 22338026 DOI: 10.1152/jn.00589.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Extracellular accumulation of amyloid beta (Aβ) is a hallmark of Alzheimer's disease (AD). It has been reported that extracellular perfusion of Aβ inhibits long-term potentiation (LTP), which is strongly related to memory in animal models. However, it has recently been proposed that intracellular Aβ may be the first pathological change to occur in AD. Here, we have investigated the effect on LTP of intracellular injection of Aβ (Aβ(1-40), Aβ(1-42)) into hippocampal pyramidal cells using patch-clamp technique. We found that injection of 1 nM Aβ(1-42) completely blocked LTP, and extracellular perfusion of a p38 MAPK inhibitor or a metabotropic glutamate receptor blocker reversed these blocking effects on LTP. Furthermore, we have examined the effects of different concentrations of Aβ(1-40) and Aβ(1-42) on LTP and showed that Aβ(1-40) required a 1,000-fold higher concentration to attenuate LTP than 1 nM Aβ(1-42). These results indicate that LTP is impaired by Aβ injected into genetically wild-type neurons in the sliced hippocampus, suggesting an acute action of intracellular Aβ on the intracellular LTP-inducing machinery.
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Affiliation(s)
- Izumi Nomura
- Department of Geriatric Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoin, Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
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112
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Kim CB, Chae CJ, Shin HR, Song KB. Measurement of beta-amyloid peptides in specific cells using a photo thin-film transistor. NANOSCALE RESEARCH LETTERS 2012; 7:72. [PMID: 22226401 PMCID: PMC3283500 DOI: 10.1186/1556-276x-7-72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 01/06/2012] [Indexed: 05/31/2023]
Abstract
The existence of beta-amyloid [Aβ] peptides in the brain has been regarded as the most archetypal biomarker of Alzheimer's disease [AD]. Recently, an early clinical diagnosis has been considered a great importance in identifying people who are at high risk of AD. However, no microscale electronic sensing devices for the detection of Aβ peptides have been developed yet. In this study, we propose an effective method to evaluate a small quantity of Aβ peptides labeled with fluorescein isothiocyanate [FITC] using a photosensitive field-effect transistor [p-FET] with an on-chip single-layer optical filter. To accurately evaluate the quantity of Aβ peptides within the cells cultured on the p-FET device, we measured the photocurrents which resulted from the FITC-conjugated Aβ peptides expressed from the cells and measured the number of photons of the fluorochrome in the cells using a photomultiplier tube. Thus, we evaluated the correlation between the generated photocurrents and the number of emitted photons. We also evaluated the correlation between the number of emitted photons and the amount of FITC by measuring the FITC volume using AFM. Finally, we estimated the quantity of Aβ peptides of the cells placed on the p-FET sensing area on the basis of the binding ratio between FITC molecules and Aβ peptides.
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Affiliation(s)
- Chang-Beom Kim
- IT Convergence Services Core Research Team, Electronics and Telecommunications Research Institute, 218 Gajeong-ro, Yuseong-gu, Daejeon, 305-700, South Korea.
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113
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Small DH. Dysregulation of Ca2+Homeostasis in Alzheimers Disease: Role in Acetylcholinesterase Production and AMPA Receptor Internalization. NEURODEGENER DIS 2012; 10:76-9. [DOI: 10.1159/000333126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Accepted: 09/03/2011] [Indexed: 11/19/2022] Open
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114
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Lim YA, Grimm A, Giese M, Mensah-Nyagan AG, Villafranca JE, Ittner LM, Eckert A, Götz J. Inhibition of the mitochondrial enzyme ABAD restores the amyloid-β-mediated deregulation of estradiol. PLoS One 2011; 6:e28887. [PMID: 22174920 PMCID: PMC3236223 DOI: 10.1371/journal.pone.0028887] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 11/16/2011] [Indexed: 11/25/2022] Open
Abstract
Alzheimer's disease (AD) is a conformational disease that is characterized by amyloid-β (Aβ) deposition in the brain. Aβ exerts its toxicity in part by receptor-mediated interactions that cause down-stream protein misfolding and aggregation, as well as mitochondrial dysfunction. Recent reports indicate that Aβ may also interact directly with intracellular proteins such as the mitochondrial enzyme ABAD (Aβ binding alcohol dehydrogenase) in executing its toxic effects. Mitochondrial dysfunction occurs early in AD, and Aβ's toxicity is in part mediated by inhibition of ABAD as shown previously with an ABAD decoy peptide. Here, we employed AG18051, a novel small ABAD-specific compound inhibitor, to investigate the role of ABAD in Aβ toxicity. Using SH-SY5Y neuroblastoma cells, we found that AG18051 partially blocked the Aβ-ABAD interaction in a pull-down assay while it also prevented the Aβ42-induced down-regulation of ABAD activity, as measured by levels of estradiol, a known hormone and product of ABAD activity. Furthermore, AG18051 is protective against Aβ42 toxicity, as measured by LDH release and MTT absorbance. Specifically, AG18051 reduced Aβ42-induced impairment of mitochondrial respiration and oxidative stress as shown by reduced ROS (reactive oxygen species) levels. Guided by our previous finding of shared aspects of the toxicity of Aβ and human amylin (HA), with the latter forming aggregates in Type 2 diabetes mellitus (T2DM) pancreas, we determined whether AG18051 would also confer protection from HA toxicity. We found that the inhibitor conferred only partial protection from HA toxicity indicating distinct pathomechanisms of the two amyloidogenic agents. Taken together, our results present the inhibition of ABAD by compounds such as AG18051 as a promising therapeutic strategy for the prevention and treatment of AD, and suggest levels of estradiol as a suitable read-out.
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Affiliation(s)
- Yun-An Lim
- Alzheimer's & Parkinson's Disease Laboratory, Brain & Mind Research Institute, University of Sydney, Camperdown, New South Wales, Australia
| | - Amandine Grimm
- Neurobiology Laboratory, Psychiatric University Clinics Basel, University of Basel, Basel, Switzerland
| | - Maria Giese
- Neurobiology Laboratory, Psychiatric University Clinics Basel, University of Basel, Basel, Switzerland
| | - Ayikoe Guy Mensah-Nyagan
- Equipe Steroïdes, Neuromodulateurs et Neuropathologies, Université de Strasbourg, Strasbourg, France
| | | | - Lars M. Ittner
- Alzheimer's & Parkinson's Disease Laboratory, Brain & Mind Research Institute, University of Sydney, Camperdown, New South Wales, Australia
| | - Anne Eckert
- Neurobiology Laboratory, Psychiatric University Clinics Basel, University of Basel, Basel, Switzerland
- * E-mail: (JG); (AE)
| | - Jürgen Götz
- Alzheimer's & Parkinson's Disease Laboratory, Brain & Mind Research Institute, University of Sydney, Camperdown, New South Wales, Australia
- * E-mail: (JG); (AE)
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115
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Sundaram RK, Kasinathan C, Stein S, Sundaram P. Novel Detox Gel Depot sequesters β-Amyloid Peptides in a mouse model of Alzheimer's Disease. Int J Pept Res Ther 2011; 18:99-106. [PMID: 22712003 DOI: 10.1007/s10989-011-9283-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Alzheimer's Disease (AD), a debilitating neurodegenerative disease is caused by aggregation and accumulation of a 39-43 amino acid peptide (amyloid β or Aβ) in brain parenchyma and cerebrovasculature. The rational approach would be to use drugs that interfere with Aβ-Aβ interaction and disrupt polymerization. Peptide ligands capable of binding to the KLVFF (amino acids 16-20) region in the Aβ molecule have been investigated as possible drug candidates. Retro-inverso (RI) peptide of this pentapeptide, ffvlk, has been shown to bind artificial fibrils made from Aβ with moderate affinity. We hypothesized that a 'detox gel', which is synthesized by covalently linking a tetrameric version of RI peptide ffvlk to poly (ethylene glycol) polymer chains will act like a 'sink' to capture Aβ peptides from the surrounding environment. We previously demonstrated that this hypothesis works in an in vitro system. The present study extended this hypothesis to an in vivo mouse model of Alzheimer's Disease and determined the therapeutic effect of our detox gel. We injected detox gel subcutaneously to AD model mice and analyzed brain levels of Aβ-42 and improvement in memory parameters. The results showed a reduction of brain amyloid burden in detox gel treated mice. Memory parameters in the treated mice improved. No undesirable immune response was observed. The data strongly suggest that our detox gel can be used as an effective therapy to deplete brain Aβ levels. Considering recent abandonment of failed antibody based therapies, our detox gel appears to have the advantage of being a non-immune based therapy.
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Affiliation(s)
- Ranjini K Sundaram
- Recombinant Technologies LLC, 1090 Meriden Waterbury Road, Suite 1, Cheshire, CT 06410
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116
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Furukawa-Hibi Y, Alkam T, Nitta A, Matsuyama A, Mizoguchi H, Suzuki K, Moussaoui S, Yu QS, Greig NH, Nagai T, Yamada K. Butyrylcholinesterase inhibitors ameliorate cognitive dysfunction induced by amyloid-β peptide in mice. Behav Brain Res 2011; 225:222-9. [PMID: 21820013 PMCID: PMC4979006 DOI: 10.1016/j.bbr.2011.07.035] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 07/15/2011] [Accepted: 07/18/2011] [Indexed: 10/17/2022]
Abstract
The cholinesterase inhibitor, rivastigmine, ameliorates cognitive dysfunction and is approved for the treatment of Alzheimer's disease (AD). Rivastigmine is a dual inhibitor of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE); however, the impact of BuChE inhibition on cognitive dysfunction remains to be determined. We compared the effects of a selective BuChE inhibitor, N1-phenethyl-norcymserine (PEC), rivastigmine and donepezil (an AChE-selective inhibitor) on cognitive dysfunction induced by amyloid-β peptide (Aβ(1-40)) in mice. Five-week-old imprinting control region (ICR) mice were injected intracerebroventricularly (i.c.v.) with either Aβ(1-40) or the control peptide Aβ(40-1) on Day 0, and their recognition memory was analyzed by a novel object recognition test. Treatment with donepezil (1.0mg/kg), rivastigmine (0.03, 0.1, 0.3mg/kg) or PEC (1.0, 3.0mg/kg) 20min prior to, or immediately after the acquisition session (Day 4) ameliorated the Aβ(1-40) induced memory impairment, indicating a beneficial effect on memory acquisition and consolidation. In contrast, none of the investigated drugs proved effective when administrated before the retention session (Day 5). Repeated daily administration of donepezil, rivastigmine or PEC, on Days 0-3 inclusively, ameliorated the cognitive dysfunction in Aβ(1-40) challenged mice. Consistent with the reversal of memory impairments, donepezil, rivastigmine or PEC treatment significantly reduced Aβ(1-40) induced tyrosine nitration of hippocampal proteins, a marker of oxidative damage. These results indicate that BuChE inhibition, as well as AChE inhibition, is a viable therapeutic strategy for cognitive dysfunction in AD.
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Affiliation(s)
- Yoko Furukawa-Hibi
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University, Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466-8560, Japan
| | - Tursun Alkam
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University, Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466-8560, Japan
| | - Atsumi Nitta
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University, Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466-8560, Japan
| | - Akihiro Matsuyama
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University, Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466-8560, Japan
| | - Hiroyuki Mizoguchi
- Futuristic Environmental Simulation Center, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan
| | - Kazuhiko Suzuki
- Translational Sciences, Novartis Pharma KK, Tokyo 106-8618, Japan
| | - Saliha Moussaoui
- Neuroscience Research, Novartis Institutes for BioMedical Research, Novartis Pharma AG, CH-4002 Basel, Switzerland
| | - Qian-Sheng Yu
- Drug Design and Development Section, Laboratory of Neuroscience, Intramural Research, Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Nigel H. Greig
- Drug Design and Development Section, Laboratory of Neuroscience, Intramural Research, Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Taku Nagai
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University, Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466-8560, Japan
| | - Kiyofumi Yamada
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University, Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466-8560, Japan
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Mateos L, Persson T, Katoozi S, Kathozi S, Gil-Bea FJ, Cedazo-Minguez A. Estrogen protects against amyloid-β toxicity by estrogen receptor α-mediated inhibition of Daxx translocation. Neurosci Lett 2011; 506:245-50. [PMID: 22119000 DOI: 10.1016/j.neulet.2011.11.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 11/04/2011] [Accepted: 11/09/2011] [Indexed: 10/15/2022]
Abstract
Estrogen was shown to promote neuronal survival against several neurotoxic insults including β-amyloid (Aβ). The proposed mechanism includes the activation of the mitogen activated protein kinase/extracellular signal-regulated kinase (Mapk/Erk), phosphatidylinositol 3-kinase/Akt pathways and the upregulation of antiapoptotic proteins. On the other hand, Aβ neurotoxicity depends on the activation of apoptosis signal-regulating kinase 1 (Ask1), and both Ask1 activity and Aβ toxicity are inhibited by thioredoxin-1 (Trx1). Here, we explored the possibility that estrogen could protect cells against Aβ(1-42) toxicity by inhibiting the Ask1 cascade or by modulating Trx1. Cytosolic translocation of death-associated protein Daxx was used as indicator of Ask1 activity. Using human SH-SY5Y neuroblastoma cells, 17β-estradiol (E2) and specific agonists for estrogen receptor (ER) α or β we demonstrated that nM concentrations of E2 protected against Aβ(1-42) by a mechanism depending upon ERα stimulation, Akt activation and Ask1 inhibition. Moreover, this protection would occur independently of ERβ and the induction of Trx1 expression. Our results emphasize the importance of Ask1 cascade in Aβ toxicity, and of ERα and Ask1 as targets for developing new neuroprotective drugs.
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Affiliation(s)
- Laura Mateos
- Karolinska Institutet, NVS, KI-Alzheimer Disease Research Center, NOVUM, 5th floor, SE-14186 Stockholm, Sweden
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118
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Jellinger KA. Interaction between α-synuclein and other proteins in neurodegenerative disorders. ScientificWorldJournal 2011; 11:1893-907. [PMID: 22125446 PMCID: PMC3217595 DOI: 10.1100/2011/371893] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 10/10/2011] [Indexed: 02/06/2023] Open
Abstract
Protein aggregation is a common characteristic of many neurodegenerative disorders, and the interaction between pathological/toxic proteins to cause neurodegeneration is a hot topic of current neuroscience research. Despite clinical, genetic, and experimental differences, evidence increasingly indicates considerable overlap between synucleinopathies and tauopathies or other protein-misfolding diseases. Inclusions, characteristics of these disorders, also occurring in other neurodegenerative diseases, suggest interactions of pathological proteins engaging common downstream pathways. Novel findings that have shifted our understanding in the role of pathologic proteins in the pathogenesis of Parkinson and Alzheimer diseases have confirmed correlations/overlaps between these and other neurodegenerative disorders. The synergistic effects of α-synuclein, hyperphosphorylated tau, amyloid-β, and other pathologic proteins, and the underlying molecular pathogenic mechanisms, including induction and spread of protein aggregates, are critically reviewed, suggesting a dualism or triad of neurodegeneration in protein-misfolding disorders, although the etiology of most of these processes is still mysterious.
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Affiliation(s)
- Kurt A Jellinger
- Institute of Clinical Neurobiology, Kenyongasse 18, A-1070 Vienna, Austria.
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119
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Hémar A, Mulle C. [Alzheimer's disease, amyloid peptide and synaptic dysfunction]. Med Sci (Paris) 2011; 27:733-6. [PMID: 21880261 DOI: 10.1051/medsci/2011278015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is the first cause of dementia that leads to insidious and progressive loss of memory and cognitive functions. In the early stages of AD, there is a strong correlation between memory impairment and cortical levels of soluble amyloid-β peptide oligomers (Aβ). It has become clear that Aβ disrupt glutamatergic synaptic function, which in turn may lead to the characteristic cognitive deficits. Conversely, experiments in rodents have conforted the notion that Aβo impairs synaptic transmission and plasticity, and that mouse models with increased production of these oligomers display cognitive impairment. Many studies have attempted to determine the mechanisms by which Aβo disrupt synaptic plasticity and mediate their detrimental effect, but the actual pathways are still poorly understood. Here we review this thriving area of research which aims at understanding the mechanisms of synaptic dysfunction in the early phase of AD, and its consequences on the activity of neural circuits.
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Affiliation(s)
- Agnès Hémar
- Institut interdisciplinaire de neurosciences, Université de Bordeaux, Bordeaux Cedex, France.
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120
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Mathew A, Yoshida Y, Maekawa T, Sakthi Kumar D. Alzheimer's disease: Cholesterol a menace? Brain Res Bull 2011; 86:1-12. [DOI: 10.1016/j.brainresbull.2011.06.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 06/17/2011] [Accepted: 06/19/2011] [Indexed: 12/20/2022]
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121
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Wang D, Yuen EY, Zhou Y, Yan Z, Xiang YK. Amyloid beta peptide-(1-42) induces internalization and degradation of beta2 adrenergic receptors in prefrontal cortical neurons. J Biol Chem 2011; 286:31852-63. [PMID: 21757762 DOI: 10.1074/jbc.m111.244335] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Emerging evidence indicates that amyloid β peptide (Aβ) initially induces subtle alterations in synaptic function in Alzheimer disease. We have recently shown that Aβ binds to β(2) adrenergic receptor (β(2)AR) and activates protein kinase A (PKA) signaling for glutamatergic regulation of synaptic activities. Here we show that in the cerebrums of mice expressing human familial mutant presenilin 1 and amyloid precursor protein genes, the levels of β(2)AR are drastically reduced. Moreover, Aβ induces internalization of transfected human β(2)AR in fibroblasts and endogenous β(2)AR in primary prefrontal cortical neurons. In fibroblasts, Aβ treatment also induces transportation of β(2)AR into lysosome, and prolonged Aβ treatment causes β(2)AR degradation. The Aβ-induced β(2)AR internalization requires the N terminus of the receptor containing the peptide binding sites and phosphorylation of β(2)AR by G protein-coupled receptor kinase, not by PKA. However, the G protein-coupled receptor kinase phosphorylation of β(2)AR and the receptor internalization are much slower than that induced by βAR agonist isoproterenol. The Aβ-induced β(2)AR internalization is also dependent on adaptor protein arrestin 3 and GTPase dynamin, but not arrestin 2. Functionally, pretreatment of primary prefrontal cortical neurons with Aβ induces desensitization of β(2)AR, which leads to attenuated response to subsequent stimulation with isoproterenol, including decreased cAMP levels, PKA activities, PKA phosphorylation of serine 845 on α-amino-2,3-dihydro-5-methyl-3-oxo-4-isoxazolepropanoic acid (AMPA) receptor subunit 1 (GluR1), and AMPA receptor-mediated miniature excitatory postsynaptic currents. This study indicates that Aβ induces β(2)AR internalization and degradation leading to impairment of adrenergic and glutamatergic activities.
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Affiliation(s)
- Dayong Wang
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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122
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Da Costa Dias B, Jovanovic K, Gonsalves D, Weiss SFT. Structural and mechanistic commonalities of amyloid-β and the prion protein. Prion 2011; 5:126-37. [PMID: 21862871 DOI: 10.4161/pri.5.3.17025] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Amyloid β (Aβ) is a major causative agent of Alzheime disease. This neurotoxic peptide is generated as a result of the cleavage of the Amyloid-Precursor-Protein (APP) by the action of beta secretase and gamma secretase. The neurotoxicity was previously thought to be the result of aggregation. However, recent studies suggest that the interaction of Aβ with numerous cell surface receptors such as N-methyl-D-aspartate (NMDA), receptor for advanced glycosylation end products (RAGE), P75 neurotrophin receptor (P75NTR) as well as cell surface proteins such as the cellular prion protein (PrP(c) ) and heparan sulfate proteoglycans (HSPG) strongly enhances Aβ induced apoptosis and thereby contributes to neurotoxicity. This review focuses on the molecular mechanism resulting in Aβ-shedding as well as Aβ-induced apoptotic processes, genetic risk factors for familial Alzheimer disease and interactions of Aβ with cell surface receptors and proteins, with particular emphasis on the cellular prion protein. Furthermore, comparisons are drawn between Alzheimer disease and prion disorders and the role of laminin, an extracellular matrix protein, glycosaminoglycans and the 37 kDa/67 kDa laminin receptor (LRP/LR) have been highlighted with regards to both neurodegenerative diseases.
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Affiliation(s)
- Bianca Da Costa Dias
- School of Molecular and Cell Biology, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, Republic of South Africa (RSA)
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123
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Modes of Aβ toxicity in Alzheimer's disease. Cell Mol Life Sci 2011; 68:3359-75. [PMID: 21706148 PMCID: PMC3181413 DOI: 10.1007/s00018-011-0750-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 06/01/2011] [Accepted: 06/06/2011] [Indexed: 12/18/2022]
Abstract
Alzheimer’s disease (AD) is reaching epidemic proportions, yet a cure is not yet available. While the genetic causes of the rare familial inherited forms of AD are understood, the causes of the sporadic forms of the disease are not. Histopathologically, these two forms of AD are indistinguishable: they are characterized by amyloid-β (Aβ) peptide-containing amyloid plaques and tau-containing neurofibrillary tangles. In this review we compare AD to frontotemporal dementia (FTD), a subset of which is characterized by tau deposition in the absence of overt plaques. A host of transgenic animal AD models have been established through the expression of human proteins with pathogenic mutations previously identified in familial AD and FTD. Determining how these mutant proteins cause disease in vivo should contribute to an understanding of the causes of the more frequent sporadic forms. We discuss the insight transgenic animal models have provided into Aβ and tau toxicity, also with regards to mitochondrial function and the crucial role tau plays in mediating Aβ toxicity. We also discuss the role of miRNAs in mediating the toxic effects of the Aβ peptide.
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124
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Changes in the physiology of CA1 hippocampal pyramidal neurons in preplaque CRND8 mice. Neurobiol Aging 2011; 33:1609-23. [PMID: 21676499 DOI: 10.1016/j.neurobiolaging.2011.05.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 04/19/2011] [Accepted: 05/03/2011] [Indexed: 12/16/2022]
Abstract
Amyloid-β protein (Aβ) is thought to play a central pathogenic role in Alzheimer's disease. Aβ can impair synaptic transmission, but little is known about the effects of Aβ on intrinsic cellular properties. Here we compared the cellular properties of CA1 hippocampal pyramidal neurons in acute slices from preplaque transgenic (Tg+) CRND8 mice and wild-type (Tg-) littermates. CA1 pyramidal neurons from Tg+ mice had narrower action potentials with faster decays than neurons from Tg- littermates. Action potential-evoked intracellular Ca(2+) transients in the apical dendrite were smaller in Tg+ than in Tg- neurons. Resting calcium concentration was higher in Tg+ than in Tg- neurons. The difference in action potential waveform was eliminated by low concentrations of tetraethylammonium ions and of 4-aminopyridine, implicating a fast delayed-rectifier potassium current. Consistent with this suggestion, there was a small increase in immunoreactivity for Kv3.1b in stratum radiatum in Tg+ mice. These changes in intrinsic properties may affect information flow through the hippocampus and contribute to the behavioral deficits observed in mouse models and patients with early-stage Alzheimer's disease.
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125
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Abstract
Alzheimer's disease is associated with synapse loss, memory dysfunction, and pathological accumulation of amyloid-β (Aβ) in plaques. However, an exclusively pathological role for Aβ is being challenged by new evidence for an essential function of Aβ at the synapse. Aβ protein exists in different assembly states in the central nervous system and plays distinct roles ranging from synapse and memory formation to memory loss and neuronal cell death. Aβ is present in the brain of symptom-free people where it likely performs important physiological roles. New evidence indicates that synaptic activity directly evokes the release of Aβ at the synapse. At physiological levels, Aβ is a normal, soluble product of neuronal metabolism that regulates synaptic function beginning early in life. Monomeric Aβ40 and Aβ42 are the predominant forms required for synaptic plasticity and neuronal survival. With age, some assemblies of Aβ are associated with synaptic failure and Alzheimer's disease pathology, possibly targeting the N-methyl-D-aspartic acid receptor through the nicotinic acetylcholine receptor, mitochondrial Aβ alcohol dehydrogenase, and cyclophilin D. But emerging data suggests a distinction between age effects on the target response in contrast to the assembly state or the accumulation of the peptide. Both aging and Aβ independently decrease neuronal plasticity. Our laboratory has reported that Aβ, glutamate, and lactic acid are each increasingly toxic with neuron age. The basis of the age-related toxicity partly resides in age-related mitochondrial dysfunction and an oxidative shift in mitochondrial and cytoplasmic redox potential. In turn, signaling through phosphorylated extracellular signal-regulated protein kinases is affected along with an age-independent increase in phosphorylated cAMP response element-binding protein. This review examines the long-awaited functional impact of Aβ on synaptic plasticity.
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Affiliation(s)
- Mordhwaj S Parihar
- School of Studies in Biotechnology & Zoology, Vikram University, Ujjain, MP, India
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126
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Bugiani O. Alzheimer’s disease: ageing-related or age-related? New hypotheses from an old debate. Neurol Sci 2011; 32:1241-7. [DOI: 10.1007/s10072-011-0614-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 04/28/2011] [Indexed: 11/28/2022]
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127
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Liu L, Li Q, Sapolsky R, Liao M, Mehta K, Bhargava A, Pasricha PJ. Transient gastric irritation in the neonatal rats leads to changes in hypothalamic CRF expression, depression- and anxiety-like behavior as adults. PLoS One 2011; 6:e19498. [PMID: 21589865 PMCID: PMC3093391 DOI: 10.1371/journal.pone.0019498] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Accepted: 04/05/2011] [Indexed: 12/27/2022] Open
Abstract
AIMS A disturbance of the brain-gut axis is a prominent feature in functional bowel disorders (such as irritable bowel syndrome and functional dyspepsia) and psychological abnormalities are often implicated in their pathogenesis. We hypothesized that psychological morbidity in these conditions may result from gastrointestinal problems, rather than causing them. METHODS Functional dyspepsia was induced by neonatal gastric irritation in male rats. 10-day old male Sprague-Dawley rats received 0.1% iodoacetamide (IA) or vehicle by oral gavage for 6 days. At 8-10 weeks of age, rats were tested with sucrose preference and forced-swimming tests to examine depression-like behavior. Elevated plus maze, open field and light-dark box tests were used to test anxiety-like behaviors. ACTH and corticosterone responses to a minor stressor, saline injection, and hypothalamic CRF expression were also measured. RESULTS Behavioral tests revealed changes of anxiety- and depression-like behaviors in IA-treated, but not control rats. As compared with controls, hypothalamic and amygdaloid CRF immunoreactivity, basal levels of plasma corticosterone and stress-induced ACTH were significantly higher in IA-treated rats. Gastric sensory ablation with resiniferatoxin had no effect on behaviors but treatment with CRF type 1 receptor antagonist, antalarmin, reversed the depression-like behavior in IA-treated rats CONCLUSIONS The present results suggest that transient gastric irritation in the neonatal period can induce a long lasting increase in depression- and anxiety-like behaviors, increased expression of CRF in the hypothalamus, and an increased sensitivity of HPA axis to stress. The depression-like behavior may be mediated by the CRF1 receptor. These findings have significant implications for the pathogenesis of psychological co-morbidity in patients with functional bowel disorders.
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Affiliation(s)
- Liansheng Liu
- Division of Gastroenterology and Hepatology, Stanford University Medical Center, Stanford, California, United States of America
| | - Qian Li
- Department of Pharmacology and Toxicology, University of Kansas, Kansas City, Kansas, United States of America
| | - Robert Sapolsky
- Department of Biology, School of Humanities and Sciences, Stanford University, Stanford, California, United States of America
| | - Min Liao
- Department of Surgery, University of California San Francisco, San Francisco, United States of America
| | - Kshama Mehta
- Division of Gastroenterology and Hepatology, Stanford University Medical Center, Stanford, California, United States of America
| | - Aditi Bhargava
- Department of Surgery, University of California San Francisco, San Francisco, United States of America
| | - Pankaj J. Pasricha
- Division of Gastroenterology and Hepatology, Stanford University Medical Center, Stanford, California, United States of America
- * E-mail:
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128
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Binding studies of truncated variants of the Aβ peptide to the V-domain of the RAGE receptor reveal Aβ residues responsible for binding. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:592-609. [DOI: 10.1016/j.bbapap.2011.02.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 02/15/2011] [Accepted: 02/18/2011] [Indexed: 11/20/2022]
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129
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Kawahara M, Ohtsuka I, Yokoyama S, Kato-Negishi M, Sadakane Y. Membrane Incorporation, Channel Formation, and Disruption of Calcium Homeostasis by Alzheimer's β-Amyloid Protein. Int J Alzheimers Dis 2011; 2011:304583. [PMID: 21547225 PMCID: PMC3087492 DOI: 10.4061/2011/304583] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2010] [Revised: 12/22/2010] [Accepted: 01/27/2011] [Indexed: 01/09/2023] Open
Abstract
Oligomerization, conformational changes, and the consequent neurodegeneration of Alzheimer's β-amyloid protein (AβP) play crucial roles in the pathogenesis of Alzheimer's disease (AD). Mounting evidence suggests that oligomeric AβPs cause the disruption of calcium homeostasis, eventually leading to neuronal death. We have demonstrated that oligomeric AβPs directly incorporate into neuronal membranes, form cation-sensitive ion channels (“amyloid channels”), and cause the disruption of calcium homeostasis via the amyloid channels. Other disease-related amyloidogenic proteins, such as prion protein in prion diseases or α-synuclein in dementia with Lewy bodies, exhibit similarities in the incorporation into membranes and the formation of calcium-permeable channels. Here, based on our experimental results and those of numerous other studies, we review the current understanding of the direct binding of AβP into membrane surfaces and the formation of calcium-permeable channels. The implication of composition of membrane lipids and the possible development of new drugs by influencing membrane properties and attenuating amyloid channels for the treatment and prevention of AD is also discussed.
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Affiliation(s)
- Masahiro Kawahara
- Department of Analytical Chemistry, School of Pharmaceutical Sciences, Kyushu University of Health and Welfare, 1714-1 Yoshino-cho, Nobeoka-shi, Miyazaki 882-8508, Japan
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130
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Sun A, Wang Q, Simonyi A, Sun G. Botanical Phenolics and Neurodegeneration. OXIDATIVE STRESS AND DISEASE 2011. [DOI: 10.1201/b10787-16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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132
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Waters J. The concentration of soluble extracellular amyloid-β protein in acute brain slices from CRND8 mice. PLoS One 2010; 5:e15709. [PMID: 21209950 PMCID: PMC3012091 DOI: 10.1371/journal.pone.0015709] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2010] [Accepted: 11/23/2010] [Indexed: 11/23/2022] Open
Abstract
Background Many recent studies of the effects of amyloid-β protein (Aβ) on brain tissue from amyloid precursor protein (APP) overexpressing mice have concluded that Aβ oligomers in the extracellular space can profoundly affect synaptic structure and function. As soluble proteins, oliomers of Aβ can diffuse through brain tissue and can presumably exit acute slices, but the rate of loss of Aβ species by diffusion from brain slices and the resulting reduced concentrations of Aβ species in brain slices are unknown. Methodology/Principal Findings Here I combine measurements of Aβ1–42 diffusion and release from acute slices and simple numerical models to measure the concentration of Aβ1–42 in intact mice (in vivo) and in acute slices from CRND8 mice. The in vivo concentration of diffusible Aβ1–42 in CRND8 mice was 250 pM at 6 months of age and 425 pM at 12 months of age. The concentration of Aβ1–42 declined rapidly after slice preparation, reaching a steady-state concentration within one hour. 50 µm from the surface of an acute slice the steady-state concentration of Aβ was 15–30% of the concentration in intact mice. In more superficial regions of the slice, where synaptic physiology is generally studied, the remaining Aβ is less than 15%. Hence the concentration of Aβ1–42 in acute slices from CRND8 mice is less than 150 pM. Conclusions/Significance Aβ affects synaptic plasticity in the picomolar concentration range. Some of the effects of Aβ may therefore be lost or altered after slice preparation, as the extracellular Aβ concentration declines from the high picomolar to the low picomolar range. Hence loss of Aβ by diffusion may complicate interpretation of the effects of Aβ in experiments on acute slices from APP overexpressing mice.
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Affiliation(s)
- Jack Waters
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America.
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133
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Rushworth JV, Hooper NM. Lipid Rafts: Linking Alzheimer's Amyloid-β Production, Aggregation, and Toxicity at Neuronal Membranes. Int J Alzheimers Dis 2010; 2011:603052. [PMID: 21234417 PMCID: PMC3014710 DOI: 10.4061/2011/603052] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 11/03/2010] [Indexed: 01/03/2023] Open
Abstract
Lipid rafts are membrane microdomains, enriched in cholesterol and sphingolipids, into which specific subsets of proteins and lipids partition, creating cell-signalling platforms that are vital for neuronal functions. Lipid rafts play at least three crucial roles in Alzheimer's Disease (AD), namely, in promoting the generation of the amyloid-β (Aβ) peptide, facilitating its aggregation upon neuronal membranes to form toxic oligomers and hosting specific neuronal receptors through which the AD-related neurotoxicity and memory impairments of the Aβ oligomers are transduced. Recent evidence suggests that Aβ oligomers may exert their deleterious effects through binding to, and causing the aberrant clustering of, lipid raft proteins including the cellular prion protein and glutamate receptors. The formation of these pathogenic lipid raft-based platforms may be critical for the toxic signalling mechanisms that underlie synaptic dysfunction and neuropathology in AD.
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Affiliation(s)
- Jo V. Rushworth
- Institute of Molecular and Cellular Biology, Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Nigel M. Hooper
- Institute of Molecular and Cellular Biology, Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
- Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, LIGHT Laboratories, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK
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Martínez de Morentin PB, González CR, López M. AMP-activated protein kinase: ‘a cup of tea’ against cholesterol-induced neurotoxicity. J Pathol 2010; 222:329-34. [DOI: 10.1002/path.2778] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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135
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Sims-Robinson C, Kim B, Rosko A, Feldman EL. How does diabetes accelerate Alzheimer disease pathology? Nat Rev Neurol 2010; 6:551-9. [PMID: 20842183 DOI: 10.1038/nrneurol.2010.130] [Citation(s) in RCA: 312] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Diabetes and Alzheimer disease (AD)-two age-related diseases-are both increasing in prevalence, and numerous studies have demonstrated that patients with diabetes have an increased risk of developing AD compared with healthy individuals. The underlying biological mechanisms that link the development of diabetes with AD are not fully understood. Abnormal protein processing, abnormalities in insulin signaling, dysregulated glucose metabolism, oxidative stress, the formation of advanced glycation end products, and the activation of inflammatory pathways are features common to both diseases. Hypercholesterolemia is another factor that has received attention, owing to its potential association with diabetes and AD. This Review summarizes the mechanistic pathways that might link diabetes and AD. An understanding of this complex interaction is necessary for the development of novel drug therapies and lifestyle guidelines aimed at the treatment and/or prevention of these diseases.
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136
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Changes in mitochondrial dynamics during amyloid β-induced PC12 cell apoptosis. Mol Cell Biochem 2010; 344:277-84. [DOI: 10.1007/s11010-010-0552-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 07/23/2010] [Indexed: 11/27/2022]
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137
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Schulz-Schaeffer WJ. The synaptic pathology of alpha-synuclein aggregation in dementia with Lewy bodies, Parkinson's disease and Parkinson's disease dementia. Acta Neuropathol 2010; 120:131-43. [PMID: 20563819 PMCID: PMC2892607 DOI: 10.1007/s00401-010-0711-0] [Citation(s) in RCA: 411] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2010] [Revised: 05/31/2010] [Accepted: 06/11/2010] [Indexed: 12/16/2022]
Abstract
Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are usually associated with loss of dopaminergic neurons. Loss of substantia nigra neurons and presence of Lewy body inclusions in some of the remaining neurons are the hallmark pathology seen in the final stages of the disease. Attempts to correlate Lewy body pathology to either cell death or severity of clinical symptoms, however, have not been successful. While the pathophysiology of the neurodegenerative process can hardly be explained by Lewy bodies, the clinical symptoms do indicate a degenerative process located at the presynapse resulting in a neurotransmitter deficiency. Recently it was shown that 90% or even more of alpha-synuclein aggregates in DLB cases were located at the presynapses in the form of very small deposits. In parallel, dendritic spines are retracted, whereas the presynapses are relatively preserved, suggesting a neurotransmitter deprivation. The same alpha-synuclein pathology can be demonstrated for PD. These findings give rise to the notion that not cell death but rather alpha-synuclein aggregate-related synaptic dysfunction causes the neurodegeneration. This opens new perspectives for understanding PD and DLB. If presynaptic alpha-synuclein aggregation, not neuronal loss, is the key issue of the neurodegenerative process, then PD and DLB may eventually be treatable in the future. The disease may progress via trans-synaptical spread, suggesting that stem cell transplants are of limited use. Future therapies may focus on the regeneration of synapses.
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Affiliation(s)
- Walter J Schulz-Schaeffer
- Department of Neuropathology, University Medical Center Göttingen, Robert-Koch-Str. 40, Göttingen, Germany.
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138
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Expression of beta-amyloid induced age-dependent presynaptic and axonal changes in Drosophila. J Neurosci 2010; 30:1512-22. [PMID: 20107079 DOI: 10.1523/jneurosci.3699-09.2010] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Alzheimer's disease (AD) is attributable to synapse dysfunction and loss, but the nature and progression of the presynaptic structural and functional changes in AD are essentially unknown. We expressed wild-type or arctic form of beta amyloid(1-42) (Abeta) in a small group of neurons in the adult fly and performed extensive time course analysis of the function and structure of both axon and presynaptic terminals at the identified single-neuron level. Abeta accumulated intracellularly and induced a range of age-dependent changes, including depletion of presynaptic mitochondria, slowdown of bi-directional transports of axonal mitochondria, decreased synaptic vesicles, increased large vacuoles, and elevated synaptic fatigue. These structural and functional synaptic changes correlated with age-dependent deficit in motor behavior. All these alterations were accelerated in flies expressing the arctic form of Abeta. The depletion of presynaptic mitochondria was the earliest detected phenotype and was not caused by the change in axonal transport of mitochondria. Moreover, axonal mitochondria exhibited a dramatic reduction in number but a significant increase in size in aged Abeta-expressing flies, indicating a global depletion of mitochondria in the neuron and an impairment of mitochondria fission. These results suggest that Abeta accumulation depletes presynaptic and axonal mitochondria, leading to other presynaptic deficits.
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139
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Kim EA, Kim H, Ahn JY, Hahn HG, Kim KS, Kim TU, Cho SW. Suppression of lipopolysaccharide-induced microglial activation by a benzothiazole derivative. Mol Cells 2010; 30:51-7. [PMID: 20652495 DOI: 10.1007/s10059-010-0087-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 03/11/2010] [Accepted: 03/25/2010] [Indexed: 12/28/2022] Open
Abstract
We previously reported that KHG21834, a benzothiazole derivative, attenuates the beta-amyloid (Abeta)-induced degeneration of both cortical and mesencephalic neurons in vitro. Central nervous system inflammation mediated by activated microglia is a key event in the development of neurodegenerative disease. In this study, we show that KHG21834 suppresses inflammation-mediated cytokine upregulation. Specifically, KHG21834 induces significant reductions in the lipopolysaccharide-induced activation of microglia and production of proinflammatory mediators such as tumor necrosis factor-alpha, interlukin-1beta, nitric oxide, and inducible nitric oxide synthase. In addition, KHG21834 blocks the expression of mitogen-activated protein kinases, including ERK, p38 MAPK, JNK, and Akt. In vivo intracerebroventricular infusion of KHG21834 also leads to decreases the level of interleukin-1beta and tumor necrosis factor-alpha in brain. These results, in combination with our previous findings on Abeta-induced degeneration, support the potential therapeutic efficacy of KHG21834 for the treatment of neurodegenerative disorders via the targeting of key glial activation pathways.
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Affiliation(s)
- Eun-A Kim
- Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736, Korea
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140
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Kim EA, Hahn HG, Kim TU, Choi SY, Cho SW. Attenuation of β-amyloid-induced neuroinflammation by KHG21834 in vivo. BMB Rep 2010; 43:413-8. [DOI: 10.5483/bmbrep.2010.43.6.413] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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141
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Chen S, Yadav SP, Surewicz WK. Interaction between human prion protein and amyloid-beta (Abeta) oligomers: role OF N-terminal residues. J Biol Chem 2010; 285:26377-83. [PMID: 20576610 DOI: 10.1074/jbc.m110.145516] [Citation(s) in RCA: 215] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Soluble oligomers of Abeta42 peptide are believed to play a major role in the pathogenesis of Alzheimer disease (AD). It was recently found that at least some of the neurotoxic effects of these oligomers may be mediated by specific binding to the prion protein, PrP(C), on the cell surface (Laurén, J., Gimbel, D. A., Nygaard, H. B., Gilbert, J. W., and Strittmatter, S. M. (2009) Nature 457, 1128-1132). Here we characterized the interaction between synthetic Abeta42 oligomers and the recombinant human prion protein (PrP) using two biophysical techniques: site-directed spin labeling and surface plasmon resonance. Our data indicate that this binding is highly specific for a particular conformation adopted by the peptide in soluble oligomeric species. The binding appears to be essentially identical for the Met(129) and Val(129) polymorphic forms of human PrP, suggesting that the role of PrP codon 129 polymorphism as a risk factor in AD is due to factors unrelated to the interaction with Abeta oligomers. It was also found that in addition to the previously identified approximately 95-110 segment, the second region of critical importance for the interaction with Abeta42 oligomers is a cluster of basic residues at the extreme N terminus of PrP (residues 23-27). The deletion of any of these segments results in a major loss of the binding function, indicating that these two regions likely act in concert to provide a high affinity binding site for Abeta42 oligomers. This insight may help explain the interplay between the postulated protective and pathogenic roles of PrP in AD and may contribute to the development of novel therapeutic strategies as well.
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Affiliation(s)
- Shugui Chen
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, USA
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142
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Lee CYD, Landreth GE. The role of microglia in amyloid clearance from the AD brain. J Neural Transm (Vienna) 2010; 117:949-60. [PMID: 20552234 DOI: 10.1007/s00702-010-0433-4] [Citation(s) in RCA: 470] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 05/26/2010] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD), the most prominent cause of senile dementia, is clinically characterized by the extracellular deposition of beta-amyloid (Abeta) and the intracellular neurofibrillary tangles. It has been well accepted that AD pathogenesis arises from perturbation in the homeostasis of Abeta in the brain. Abeta is normally produced at high levels in the brain and cleared in an equivalent rate. Thus, even a moderate decrease in the clearance leads to the accumulation of Abeta and subsequent amyloid deposition. Microglia are the tissue macrophages in the central nervous system (CNS) and have been shown to play major roles in internalization and degradation of Abeta. Abeta exists in the brain both in soluble and in fibrillar forms. Microglia interact with these two forms of Abeta in different ways. They take up soluble forms of Abeta through macropinocytosis and LDL receptor-related proteins (LRPs) mediated pathway. Fibrillar forms of Abeta interact with the cell surface innate immune receptor complex, initiating intracellular signaling cascades that stimulate phagocytosis. Inflammatory responses influence the activation status of microglia and subsequently regulate their ability to take up and degrade Abeta. ApoE and its receptors have been shown to play critical roles in these processes. In this review, we will explore the mechanisms that microglia utilize to clear Abeta and the effectors that modulate the processes.
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Affiliation(s)
- C Y Daniel Lee
- School of Medicine, Case Western Reserve University, SOM E649, 10900 Euclid Avenue, Cleveland, OH 44106-4928, USA.
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143
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Rivière C, Papastamoulis Y, Fortin PY, Delchier N, Andriamanarivo S, Waffo-Teguo P, Kapche GD, Amira-Guebalia H, Delaunay JC, Mérillon JM, Richard T, Monti JP. New stilbene dimers against amyloid fibril formation. Bioorg Med Chem Lett 2010; 20:3441-3. [DOI: 10.1016/j.bmcl.2009.09.074] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 09/16/2009] [Accepted: 09/18/2009] [Indexed: 11/16/2022]
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144
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Douglas PM, Cyr DM. Interplay between protein homeostasis networks in protein aggregation and proteotoxicity. Biopolymers 2010; 93:229-36. [PMID: 19768782 DOI: 10.1002/bip.21304] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The misfolding and aggregation of disease proteins is characteristic of numerous neurodegenerative diseases. Particular neuronal populations are more vulnerable to proteotoxicity while others are more apt to tolerate the misfolding and aggregation of disease proteins. Thus, the cellular environment must play a significant role in determining whether disease proteins are converted into toxic or benign forms. The endomembrane network of eukaryotes divides the cell into different subcellular compartments that possess distinct sets of molecular chaperones and protein interaction networks. Chaperones act as agonists and antagonists of disease protein aggregation to prevent the accumulation of toxic intermediates in the aggregation pathway. Interacting partners can also modulate the conformation and localization of disease proteins and thereby influence proteotoxicity. Thus, interplay between these protein homeostasis network components can modulate the self-association of disease proteins and determine whether they elicit a toxic or benign outcome.
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Affiliation(s)
- Peter M Douglas
- Department of Cell and Developmental Biology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599-7090, USA
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145
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Gibbs ME, Maksel D, Gibbs Z, Hou X, Summers RJ, Small DH. Memory loss caused by β-amyloid protein is rescued by a β3-adrenoceptor agonist. Neurobiol Aging 2010; 31:614-24. [DOI: 10.1016/j.neurobiolaging.2008.05.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2007] [Revised: 04/20/2008] [Accepted: 05/21/2008] [Indexed: 10/21/2022]
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146
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PI3 kinase signaling is involved in Abeta-induced memory loss in Drosophila. Proc Natl Acad Sci U S A 2010; 107:7060-5. [PMID: 20351282 DOI: 10.1073/pnas.0909314107] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Multiple intracellular signals are altered in Alzheimer's disease brain tissues, including the PI3K/Akt pathway. However, the pathological relevance of such alterations is poorly understood. In vitro studies yield results that seem to be consistent with the conventional perception in which an up-regulation of the cell survival pathway, PI3K pathway, is protective in Alzheimer's disease pathogenesis. The current in vivo genetic approach, however, reveals that inhibition of the PI3K pathway leads to rescuing of the beta-amyloid peptide (Abeta)-induced memory loss in the Drosophila brain. We began our inquiry into the molecular basis of this memory loss by studying Abeta42-induced enhancement of long-term depression. We found that long-term depression is restored to a normal level through inhibition of PI3K activity. Abeta42-induced PI3K hyperactivity is directly confirmed by immunostaining of the PI3K phosphorylation targets, phospholipids. Such observations lead to the following demonstration that Abeta42-induced memory loss can be rescued through genetic silencing or pharmacological inhibition of PI3K functions. Our data suggest that Abeta42 stimulates PI3K, which in turn causes memory loss in association with an increase in accumulation of Abeta42 aggregates.
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147
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Kerr ML, Gasperini R, Gibbs ME, Hou X, Shepherd CE, Strickland DK, Foa L, Lawen A, Small DH. Inhibition of Aβ aggregation and neurotoxicity by the 39-kDa receptor-associated protein. J Neurochem 2010; 112:1199-209. [DOI: 10.1111/j.1471-4159.2009.06540.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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148
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Cerpa W, Farías GG, Godoy JA, Fuenzalida M, Bonansco C, Inestrosa NC. Wnt-5a occludes Abeta oligomer-induced depression of glutamatergic transmission in hippocampal neurons. Mol Neurodegener 2010; 5:3. [PMID: 20205789 PMCID: PMC2823745 DOI: 10.1186/1750-1326-5-3] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2009] [Accepted: 01/18/2010] [Indexed: 01/08/2023] Open
Abstract
Background Soluble amyloid-β (Aβ;) oligomers have been recognized to be early and key intermediates in Alzheimer's disease (AD)-related synaptic dysfunction. Aβ oligomers block hippocampal long-term potentiation (LTP) and impair rodent spatial memory. Wnt signaling plays an important role in neural development, including synaptic differentiation. Results We report here that the Wnt signaling activation prevents the synaptic damage triggered by Aβ oligomers. Electrophysiological analysis of Schaffer collaterals-CA1 glutamatergic synaptic transmission in hippocampal slices indicates that Wnt-5a increases the amplitude of field excitatory postsynaptic potentials (fEPSP) and both AMPA and NMDA components of the excitatory postsynaptic currents (EPSCs), without modifying the paired pulse facilitation (PPF). Conversely, in the presence of Aβ oligomers the fEPSP and EPSCs amplitude decreased without modification of the PPF, while the postsynaptic scaffold protein (PSD-95) decreased as well. Co-perfusion of hippocampal slices with Wnt-5a and Aβ oligomers occludes against the synaptic depression of EPSCs as well as the reduction of PSD-95 clusters induced by Aβ oligomers in neuronal cultures. Taken together these results indicate that Wnt-5a and Aβ oligomers inversely modulate postsynaptic components. Conclusion These results indicate that post-synaptic damage induced by Aβ oligomers in hippocampal neurons is prevented by non-canonical Wnt pathway activation.
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Affiliation(s)
- Waldo Cerpa
- Centro de Envejecimiento y Regeneración (CARE), Centro de Regulación Celular y Patología "Joaquín V, Luco" (CRCP), MIFAB, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
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Bales KR, Plath N, Svenstrup N, Menniti FS. Phosphodiesterase Inhibition to Target the Synaptic Dysfunction in Alzheimer’s Disease. TOPICS IN MEDICINAL CHEMISTRY 2010. [DOI: 10.1007/7355_2010_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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150
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Abstract
BACKGROUND Dementia and Parkinsonism are two major neurodegenerative disorders. Accurate diagnosis can be difficult when patients have both syndromes because of a wide range of etiologies. OBJECTIVES To improve clinical diagnosis, we propose a disease classification based on the pathological proteins which are involved in the neuropathological disease process. DESIGN Four neuropathological classes are proposed based on four major proteins, tau, A beta, alpha -synuclein and TDP43 : 1/ Tauopathy and amyloidopathy with possible Parkinsonism, 2/ Tauopathy with predominant Parkinsonism, 3/ Synucleinopathies with cognitive impairment/dementia and 4/ The TAR DNA binding protein 43 (TDP-43). This classification raises certain questions in clinical practice due to intriguing overlaps between clinical presentations despite the same pathological protein being involved. CONCLUSION The development of molecular and pathological protein research in neurodegenerative disorders can help classify the clinical association of dementia and Parkinsonism and improve therapeutic strategies against proteins involved in the degenerative process.
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Affiliation(s)
- A Gabelle
- Service de Neurologie, CHRU Montpellier, Hopital Gui de Chauliac, Montpellier Cedex 5, France.
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