201
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Sankar SB, Donegan RK, Shah KJ, Reddi AR, Wood LB. Heme and hemoglobin suppress amyloid β-mediated inflammatory activation of mouse astrocytes. J Biol Chem 2018; 293:11358-11373. [PMID: 29871926 DOI: 10.1074/jbc.ra117.001050] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 05/24/2018] [Indexed: 11/06/2022] Open
Abstract
Glial immune activity is a key feature of Alzheimer's disease (AD). Given that the blood factors heme and hemoglobin (Hb) are both elevated in AD tissues and have immunomodulatory roles, here we sought to interrogate their roles in modulating β-amyloid (Aβ)-mediated inflammatory activation of astrocytes. We discovered that heme and Hb suppress immune activity of primary mouse astrocytes by reducing expression of several proinflammatory cytokines (e.g. RANTES (regulated on activation normal T cell expressed and secreted)) and the scavenger receptor CD36 and reducing internalization of Aβ(1-42) by astrocytes. Moreover, we found that certain soluble (>75-kDa) Aβ(1-42) oligomers are primarily responsible for astrocyte activation and that heme or Hb association with these oligomers reverses inflammation. We further found that heme up-regulates phosphoprotein signaling in the phosphoinositide 3-kinase (PI3K)/Akt pathway, which regulates a number of immune functions, including cytokine expression and phagocytosis. The findings in this work suggest that dysregulation of Hb and heme levels in AD brains may contribute to impaired amyloid clearance and that targeting heme homeostasis may reduce amyloid pathogenesis. Altogether, we propose heme as a critical molecular link between amyloid pathology and AD risk factors, such as aging, brain injury, and stroke, which increase Hb and heme levels in the brain.
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Affiliation(s)
- Sitara B Sankar
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Rebecca K Donegan
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Kajol J Shah
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Amit R Reddi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332; Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332.
| | - Levi B Wood
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332; Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332.
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202
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Foroutanpay B, Kumar J, Kang S, Danaei N, Westaway D, Sim V, Kar S. The Effects of N-terminal Mutations on β-amyloid Peptide Aggregation and Toxicity. Neuroscience 2018; 379:177-188. [DOI: 10.1016/j.neuroscience.2018.03.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 03/01/2018] [Accepted: 03/12/2018] [Indexed: 12/31/2022]
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203
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Wolfe MS. Dysfunctional γ-Secretase in Familial Alzheimer's Disease. Neurochem Res 2018; 44:5-11. [PMID: 29619615 PMCID: PMC6592691 DOI: 10.1007/s11064-018-2511-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 03/19/2018] [Indexed: 12/24/2022]
Abstract
Genetics strongly implicate the amyloid β-peptide (Aβ) in the pathogenesis of Alzheimer's disease. Dominant missense mutation in the presenilins and the amyloid precursor protein (APP) cause early-onset familial Alzheimer's disease (FAD). As presenilin is the catalytic component of the γ-secretase protease complex that produces Aβ from APP, mutation of the enzyme or substrate that produce Aβ leads to FAD. However, the mechanism by which presenilin mutations cause FAD has been controversial, with gain of function and loss of function offered as binary choices. This overview will instead present the case that presenilins are dysfunctional in FAD. γ-Secretase is a multi-functional enzyme that proteolyzes the APP transmembrane domain in a complex and processive manner. Reduction in a specific function-the carboxypeptidase trimming of initially formed long Aβ peptides containing most of the transmembrane domain to shorter secreted forms-is an emerging common feature of FAD-mutant γ-secretase complexes.
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Affiliation(s)
- Michael S Wolfe
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, 66045, USA.
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204
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Chang CC, Edwald E, Veatch S, Steel DG, Gafni A. Interactions of amyloid-β peptides on lipid bilayer studied by single molecule imaging and tracking. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1616-1624. [PMID: 29580771 DOI: 10.1016/j.bbamem.2018.03.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 03/16/2018] [Accepted: 03/17/2018] [Indexed: 12/17/2022]
Abstract
The amyloid-β peptides (Aβ40 and Aβ42) feature prominently in the synaptic dysfunction and neuronal loss associated with Alzheimer's disease (AD). This has been proposed to be due either to interactions between Aβ and cell surface receptors affecting cell signaling, or to the formation of calcium-permeable channels in the membrane that disrupt calcium homeostasis. In both mechanisms the cell membrane is the primary cellular structure with which Aβ interacts. Aβ concentrations in human bodily fluids are very low (pM-nM) rendering studies of the size, composition, cellular binding sites and mechanism of action of the oligomers formed in vivo very challenging. Most studies, therefore, have utilized Aβ oligomers prepared at micromolar peptide concentrations, where Aβ forms oligomeric species which possess easily observable cell toxicity. Such toxicity has not been observed when nM concentrations of peptide are used in the experiment highlighting the importance of employing physiologically relevant peptide concentrations for the results to be of biological significance. In this paper single-molecule microscopy was used to monitor Aβ oligomer formation and diffusion on a supported lipid bilayer at nanomolar peptide concentrations. Aβ monomers, the dominant species in solution, tightly associate with the membrane and are highly mobile whereas trimers and higher-order oligomers are largely immobile. Aβ dimers exist in a mixture of mobile and immobile states. Oligomer growth on the membrane is more rapid for Aβ40 than for the more amyloidogenic Aβ42 but is largely inhibited for a 1:1 Aβ40:Aβ42 mixture. The mechanism underlying these Aβ40-Aβ42 interactions may feature in Alzheimer's pathology.
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Affiliation(s)
- Chun-Chieh Chang
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Elin Edwald
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sarah Veatch
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Duncan G Steel
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA; Department of Physics, University of Michigan, Ann Arbor, MI 48109, USA; Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ari Gafni
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
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205
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Intrahippocampal injection of a lentiviral vector expressing neurogranin enhances cognitive function in 5XFAD mice. Exp Mol Med 2018; 50:e461. [PMID: 29568074 PMCID: PMC5898899 DOI: 10.1038/emm.2017.302] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/27/2017] [Accepted: 10/09/2017] [Indexed: 02/08/2023] Open
Abstract
Progressive cognitive declines are the main clinical symptoms of Alzheimer's disease (AD). Cognitive impairment in AD is directly correlated with amyloid beta (Aβ)-mediated synaptic deficits. It is known that upregulation of neurogranin (Ng), a postsynaptic protein, contributes to the enhancement of synaptic plasticity and cognitive function. By contrast, downregulation of Ng expression results in learning and memory impairments. Interestingly, Ng expression is significantly reduced in the parenchyma of brains with AD. However, the pathological role that downregulated Ng plays in the cognitive dysfunctions observed in AD remains unclear. Therefore, the present study examined whether enhancing Ng expression affected cognitive functions in 5XFAD mice, an animal model of AD. We found that the Ng reductions and cognitive decline observed in 5XFAD mice were restored in mice that were intrahippocampally injected with an Ng-expressing lentiviral vector. Furthermore, overexpression of Ng upregulated expression of postsynaptic density protein-95 in the hippocampus of 5XFAD mice. These results suggest that the cause of cognitive decline in AD may be at least partially associated with reduced Ng levels, and thus, supplementation of Ng may be an appropriate therapeutic strategy for individuals with AD.
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206
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Wang X, Kastanenka KV, Arbel-Ornath M, Commins C, Kuzuya A, Lariviere AJ, Krafft GA, Hefti F, Jerecic J, Bacskai BJ. An acute functional screen identifies an effective antibody targeting amyloid-β oligomers based on calcium imaging. Sci Rep 2018; 8:4634. [PMID: 29545579 PMCID: PMC5854710 DOI: 10.1038/s41598-018-22979-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 03/05/2018] [Indexed: 12/15/2022] Open
Abstract
Soluble amyloid β oligomers (AβOs) are widely recognized neurotoxins that trigger aberrant signaling in specific subsets of neurons, leading to accumulated neuronal damage and memory disorders in Alzheimer's disease (AD). One of the profound downstream consequences of AβO-triggered events is dysregulation of cytosolic calcium concentration ([Ca2+]i), which has been implicated in synaptic failure, cytoskeletal abnormalities, and eventually neuronal death. We have developed an in vitro/in vivo drug screening assay to evaluate putative AβO-blocking candidates by measuring AβO-induced real-time changes in [Ca2+]i. Our screening assay demonstrated that the anti-AβO monoclonal antibody ACU3B3 exhibits potent blocking capability against a broad size range of AβOs. We showed that picomolar concentrations of AβOs were capable of increasing [Ca2+]i in primary neuronal cultures, an effect prevented by ACU3B3. Topical application of 5 nM AβOs onto exposed cortical surfaces also elicited significant calcium elevations in vivo, which was completely abolished by pre-treatment of the brain with 1 ng/mL (6.67 pM) ACU3B3. Our results provide strong support for the utility of this functional screening assay in identifying and confirming the efficacy of AβO-blocking drug candidates such as the human homolog of ACU3B3, which may emerge as the first experimental AD therapeutic to validate the amyloid oligomer hypothesis.
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Affiliation(s)
- Xueying Wang
- Massachusetts General Hospital, Department of Neurology, 114 16th Street, Charlestown, MA, 02129, USA
- Harvard University, Center for Brain Science, 52 Oxford Street, Cambridge, MA, 02138, USA
| | - Ksenia V Kastanenka
- Massachusetts General Hospital, Department of Neurology, 114 16th Street, Charlestown, MA, 02129, USA
| | - Michal Arbel-Ornath
- Massachusetts General Hospital, Department of Neurology, 114 16th Street, Charlestown, MA, 02129, USA
| | - Caitlin Commins
- Massachusetts General Hospital, Department of Neurology, 114 16th Street, Charlestown, MA, 02129, USA
| | - Akira Kuzuya
- Massachusetts General Hospital, Department of Neurology, 114 16th Street, Charlestown, MA, 02129, USA
| | - Amanda J Lariviere
- Massachusetts General Hospital, Department of Neurology, 114 16th Street, Charlestown, MA, 02129, USA
| | - Grant A Krafft
- Acumen Pharmaceuticals, Inc., 4435 North First Street, #360, Livermore, CA, 94551, USA
| | - Franz Hefti
- Acumen Pharmaceuticals, Inc., 4435 North First Street, #360, Livermore, CA, 94551, USA
| | - Jasna Jerecic
- Acumen Pharmaceuticals, Inc., 4435 North First Street, #360, Livermore, CA, 94551, USA.
| | - Brian J Bacskai
- Massachusetts General Hospital, Department of Neurology, 114 16th Street, Charlestown, MA, 02129, USA.
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207
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Rhynchophylline suppresses soluble Aβ 1-42-induced impairment of spatial cognition function via inhibiting excessive activation of extrasynaptic NR2B-containing NMDA receptors. Neuropharmacology 2018; 135:100-112. [PMID: 29510187 DOI: 10.1016/j.neuropharm.2018.03.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 02/15/2018] [Accepted: 03/03/2018] [Indexed: 01/06/2023]
Abstract
Rhynchophylline (RIN) is a significant active component isolated from the Chinese herbal medicine Uncaria rhynchophylla. The overproduction of soluble amyloid β protein (Aβ) oligomers in the hippocampus is closely involved in impairments in cognitive function at the early stage of Alzheimer's disease (AD). Growing evidences show that RIN possesses neuroprotective effects against Aβ-induced neurotoxicity. However, whether RIN can prevent soluble Aβ1-42-induced impairments in spatial cognitive function and synaptic plasticity is still unclear. Using the combined methods of behavioral tests, immunofluorescence and electrophysiological recordings, we characterized the key neuroprotective properties of RIN and its possible cellular and molecular mechanisms against soluble Aβ1-42-related impairments in rats. Our findings are as follows: (1) RIN efficiently rescued the soluble Aβ1-42-induced spatial learning and memory deficits in the Morris water maze test and prevented soluble Aβ1-42-induced suppression in long term potentiation (LTP) in the entorhinal cortex (EC)-dentate gyrus (DG) circuit. (2) Excessive activation of extrasynaptic GluN2B-NMDAR and subsequent Ca2+ overload contributed to the soluble Aβ1-42-induced impairments in spatial cognitive function and synaptic plasticity. (3) RIN prevented Aβ1-42-induced excessive activation of extrasynaptic NMDARs by reducing extrasynaptic NMDARs -mediated excitatory postsynaptic currents and down regulating GluN2B-NMDAR expression in the DG region, which inhibited Aβ1-42-induced Ca2+ overload mediated by extrasynanptic NMDARs. The results suggest that RIN could be an effective therapeutic candidate for cognitive impairment in AD.
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208
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Yulug B, Hanoglu L, Ozansoy M, Isık D, Kilic U, Kilic E, Schabitz WR. Therapeutic role of rifampicin in Alzheimer's disease. Psychiatry Clin Neurosci 2018; 72:152-159. [PMID: 29315976 DOI: 10.1111/pcn.12637] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/06/2017] [Accepted: 12/17/2017] [Indexed: 12/11/2022]
Abstract
Rifampicin exerts significant brain protective functions in multiple experimental models. Here we summarize the underlying mechanisms of the neuroprotective and pro-cognitive effects of rifampicin that are mediated by its anti-inflammatory, anti-tau, anti-amyloid, and cholinergic effects. Beyond suggesting that rifampicin shows strong brain protective effects in preclinical models of Alzheimer's disease, we also provide substantial clinical evidence for the neuroprotective and pro-cognitive effects of rifampicin. Future neuroimaging studies combined with clinical assessment scores are the following steps to be taken in this field of research.
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Affiliation(s)
- Burak Yulug
- Department of Neurology, Istanbul Medipol University, Istanbul, Turkey.,Department of Restorative and Regenerative Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Lütfü Hanoglu
- Department of Neurology, Istanbul Medipol University, Istanbul, Turkey.,Department of Restorative and Regenerative Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Mehmet Ozansoy
- Department of Restorative and Regenerative Medicine, Istanbul Medipol University, Istanbul, Turkey.,Department of Physiology, International School of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Dogan Isık
- Department of Psychiatry, Istanbul Medipol University, Istanbul, Turkey
| | - Ulkan Kilic
- Department of Medical Biology, Faculty of Medicine, University of Health Sciences, Istanbul, Turkey
| | - Ertugrul Kilic
- Department of Restorative and Regenerative Medicine, Istanbul Medipol University, Istanbul, Turkey.,Department of Physiology, International School of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Wolf Rüdiger Schabitz
- Department of Neurology, Bethel, EVKB, Bielefeld, University of Münster, Münster, Germany
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209
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A key role for MAM in mediating mitochondrial dysfunction in Alzheimer disease. Cell Death Dis 2018; 9:335. [PMID: 29491396 PMCID: PMC5832428 DOI: 10.1038/s41419-017-0215-0] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 11/27/2017] [Accepted: 12/06/2017] [Indexed: 12/19/2022]
Abstract
In the last few years, increased emphasis has been devoted to understanding the contribution of mitochondria-associated endoplasmic reticulum (ER) membranes (MAM) to human pathology in general, and neurodegenerative diseases in particular. A major reason for this is the central role that this subdomain of the ER plays in metabolic regulation and in mitochondrial biology. As such, aberrant MAM function may help explain the seemingly unrelated metabolic abnormalities often seen in neurodegeneration. In the specific case of Alzheimer disease (AD), besides perturbations in calcium and lipid homeostasis, there are numerous documented alterations in mitochondrial behavior and function, including reduced respiratory chain activity and oxidative phosphorylation, increased free radical production, and altered organellar morphology, dynamics, and positioning (especially perinuclear mitochondria). However, whether these alterations are primary events causative of the disease, or are secondary downstream events that are the result of some other, more fundamental problem, is still unclear. In support of the former possibility, we recently reported that C99, the C-terminal processing product of the amyloid precursor protein (APP) derived from its cleavage by β-secretase, is present in MAM, that its level is increased in AD, and that this increase reduces mitochondrial respiration, likely via a C99-induced alteration in cellular sphingolipid homeostasis. Thus, the metabolic disturbances seen in AD likely arise from increased ER-mitochondrial communication that is driven by an increase in the levels of C99 at the MAM.
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210
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Baazaoui N, Flory M, Iqbal K. Synaptic Compensation as a Probable Cause of Prolonged Mild Cognitive Impairment in Alzheimer's Disease: Implications from a Transgenic Mouse Model of the Disease. J Alzheimers Dis 2018; 56:1385-1401. [PMID: 28222506 DOI: 10.3233/jad-160845] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Alzheimer's disease (AD) is a slow, progressive neurodegenerative disease in which cognitive decline takes place over a period of several years with a very variable period of mild cognitive impairment (MCI) and, in some cases, relatively long period before progression to dementia. The cognitive deficit during MCI is probably due to neuronal loss, an intermediate level of amyloid-β (Aβ) plaques and neurofibrillary tangles (NFT) and synaptosis, which is interrupted with a transient compensatory increase. We found impairment in reference memory accompanied by a decrease in the expression of synaptophysin, β-III tubulin, and MAP2 and a trend for GluR1, at 12 weeks of age in 3xTg-AD mice (hAPPSwe, P301L tau, PS1 [M146V] knock-in), a widely used transgenic model of AD. Past 12 weeks, the cross-sectional analysis of different age groups showed a compensatory increase in synaptic markers relative to that in wild type animals in a topographic and time-dependent manner. When studied across time we found that in 3xTg-AD mice, the compensatory phenomenon occurred in parallel in different regions of the brain. However, this attempt of the brain to repair itself was able to only partially rescue cognitive impairment. These findings for the first time raise the intriguing possibility that AD causing mutated transgenes may initially cause an increase in synaptic and dendritic markers as a compensatory mechanism for synaptic deficit, and this phenomenon, though transient, could be the biological basis of the period of MCI seen in AD.
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Affiliation(s)
- Narjes Baazaoui
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, NY, USA.,Graduate Program in Biology (Neuroscience), College of Staten Island (CSI), City University of New York (CUNY) Graduate Center, New York, NY, USA
| | - Michael Flory
- Research Design and Analysis Service, New York State Institute for Basic Research in DevelopmentalDisabilities, NY, USA
| | - Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, NY, USA
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211
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Cruz E, Kumar S, Yuan L, Arikkath J, Batra SK. Intracellular amyloid beta expression leads to dysregulation of the mitogen-activated protein kinase and bone morphogenetic protein-2 signaling axis. PLoS One 2018; 13:e0191696. [PMID: 29470488 PMCID: PMC5823380 DOI: 10.1371/journal.pone.0191696] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/09/2018] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative syndrome classically depicted by the parenchymal accumulation of extracellular amyloid beta plaques. However, recent findings suggest intraneuronal amyloid beta (iAβ1-42) accumulation precedes extracellular deposition. Furthermore, the pathologic increase in iAβ1-42 has been implicated in dysregulation of cellular mechanisms critically important in axonal transport. Owing to neuronal cell polarity, retrograde and anterograde axonal transport are essential trafficking mechanism necessary to convey membrane bound neurotransmitters, neurotrophins, and endosomes between soma and synaptic interfaces. Although iAβ1-42 disruption of axonal transport has been implicated in dysregulation of neuronal synaptic transmission, the role of iAβ1-42 and its influence on signal transduction involving the mitogen-activated protein kinase (MAPK) and morphogenetic signaling axis are unknown. Our biochemical characterization of intracellular amyloid beta accumulation on MAPK and morphogenetic signaling have revealed increased iAβ1-42 expression leads to significant reduction in ERK 1/2 phosphorylation and increased bone morphogenetic protein 2 dependent Smad 1/5/8 phosphorylation. Furthermore, rescue of iAβ1-42 mediated attenuation of MAPK signaling can be accomplished with the small molecule PLX4032 as a downstream enhancer of the MAPK pathway. Consequently, our observations regarding the dysregulation of these gatekeepers of neuronal viability may have important implications in understanding the iAβ1-42 mediated effects observed in AD.
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Affiliation(s)
- Eric Cruz
- Department of Biochemistry and Molecular Biology, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Sushil Kumar
- Department of Biochemistry and Molecular Biology, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Li Yuan
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Jyothi Arikkath
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Surinder K. Batra
- Department of Biochemistry and Molecular Biology, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
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212
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Özdemir Z, Bildziukevich U, Wimmerová M, Macůrková A, Lovecká P, Wimmer Z. Plant Adaptogens: Natural Medicaments for 21st
Century? ChemistrySelect 2018. [DOI: 10.1002/slct.201702682] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Zülal Özdemir
- University of Chemistry and Technology in Prague, Faculty of Food and Biochemical Technology; Department of Chemistry of Natural Compounds; Technická 5 16628 Prague 6 Czech Republic
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic; Isotope Laboratory; Vídeňská 1083 14220 Prague 4 Czech Republic
| | - Uladzimir Bildziukevich
- University of Chemistry and Technology in Prague, Faculty of Food and Biochemical Technology; Department of Chemistry of Natural Compounds; Technická 5 16628 Prague 6 Czech Republic
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic; Isotope Laboratory; Vídeňská 1083 14220 Prague 4 Czech Republic
| | - Martina Wimmerová
- University of Chemistry and Technology in Prague, Faculty of Food and Biochemical Technology; Department of Chemistry of Natural Compounds; Technická 5 16628 Prague 6 Czech Republic
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic; Isotope Laboratory; Vídeňská 1083 14220 Prague 4 Czech Republic
| | - Anna Macůrková
- University of Chemistry and Technology in Prague, Faculty of Food and Biochemical Technology; Department of Biochemistry and Microbiology; Technická 5 16628 Prague 6 Czech Republic
| | - Petra Lovecká
- University of Chemistry and Technology in Prague, Faculty of Food and Biochemical Technology; Department of Biochemistry and Microbiology; Technická 5 16628 Prague 6 Czech Republic
| | - Zdeněk Wimmer
- University of Chemistry and Technology in Prague, Faculty of Food and Biochemical Technology; Department of Chemistry of Natural Compounds; Technická 5 16628 Prague 6 Czech Republic
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic; Isotope Laboratory; Vídeňská 1083 14220 Prague 4 Czech Republic
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213
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Environmental enrichment and exercise are better than social enrichment to reduce memory deficits in amyloid beta neurotoxicity. Proc Natl Acad Sci U S A 2018; 115:E2403-E2409. [PMID: 29463708 DOI: 10.1073/pnas.1718435115] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Recently, nongenetic animal models to study the onset and development of Alzheimer's disease (AD) have appeared, such as the intrahippocampal infusion of peptides present in Alzheimer amyloid plaques [i.e., amyloid-β (Aβ)]. Nonpharmacological approaches to AD treatment also have been advanced recently, which involve combinations of behavioral interventions whose specific effects are often difficult to determine. Here we isolate the neuroprotective effects of three of these interventions-environmental enrichment (EE), anaerobic physical exercise (AnPE), and social enrichment (SE)-on Aβ-induced oxidative stress and on impairments in learning and memory induced by Aβ. Wistar rats were submitted to 8 wk of EE, AnPE, or SE, followed by Aβ infusion in the dorsal hippocampus. Short-term memory (STM) and long-term memory (LTM) of object recognition (OR) and social recognition (SR) were evaluated. Biochemical assays determined hippocampal oxidative status: reactive oxygen species, lipid peroxidation by thiobarbituric acid reactive substance (TBARS) test, and total antioxidant capacity by ferric reducing/antioxidant power (FRAP), as well as acetylcholinesterase activity. Aβ infusion resulted in memory deficits and hippocampal oxidative damage. EE and AnPE prevented all memory deficits (STM and LTM of OR and SR) and lipid peroxidation (i.e., TBARS). SE prevented only the SR memory deficits and the decrease of total antioxidant capacity decrease (i.e., FRAP). Traditionally, findings obtained with EE protocols do not allow discrimination of the roles of the three individual factors involved. Here we demonstrate that EE and physical exercise have better neuroprotective effects than SE in memory deficits related to Aβ neurotoxicity in the AD model tested.
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214
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Upadhyay A, Mishra A. Amyloids of multiple species: are they helpful in survival? Biol Rev Camb Philos Soc 2018; 93:1363-1386. [DOI: 10.1111/brv.12399] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 01/13/2018] [Accepted: 01/18/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Arun Upadhyay
- Cellular and Molecular Neurobiology Unit; Indian Institute of Technology Jodhpur; Rajasthan 342011 India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit; Indian Institute of Technology Jodhpur; Rajasthan 342011 India
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215
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CoMFA and CoMSIA-based designing of resveratrol derivatives as amyloid-beta aggregation inhibitors against Alzheimer's disease. Med Chem Res 2018. [DOI: 10.1007/s00044-018-2138-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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216
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Alpha7 nicotinic acetylcholine receptor-specific agonist DMXBA (GTS-21) attenuates Aβ accumulation through suppression of neuronal γ-secretase activity and promotion of microglial amyloid-β phagocytosis and ameliorates cognitive impairment in a mouse model of Alzheimer's disease. Neurobiol Aging 2018; 62:197-209. [DOI: 10.1016/j.neurobiolaging.2017.10.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 09/30/2017] [Accepted: 10/26/2017] [Indexed: 01/04/2023]
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217
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Virgili J, Lebbadi M, Tremblay C, St-Amour I, Pierrisnard C, Faucher-Genest A, Emond V, Julien C, Calon F. Characterization of a 3xTg-AD mouse model of Alzheimer's disease with the senescence accelerated mouse prone 8 (SAMP8) background. Synapse 2018; 72. [DOI: 10.1002/syn.22025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 01/11/2018] [Accepted: 01/16/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Jessica Virgili
- Faculté de Pharmacie; Université Laval; Quebec Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec; Université Laval; Québec Canada
| | - Meryem Lebbadi
- Faculté de Pharmacie; Université Laval; Quebec Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec; Université Laval; Québec Canada
| | - Cyntia Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec; Université Laval; Québec Canada
| | - Isabelle St-Amour
- Axe Neurosciences, Centre de Recherche du CHU de Québec; Université Laval; Québec Canada
| | - Caroline Pierrisnard
- Faculté de Pharmacie; Université Laval; Quebec Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec; Université Laval; Québec Canada
| | - Audrey Faucher-Genest
- Axe Neurosciences, Centre de Recherche du CHU de Québec; Université Laval; Québec Canada
| | - Vincent Emond
- Axe Neurosciences, Centre de Recherche du CHU de Québec; Université Laval; Québec Canada
| | - Carl Julien
- Faculté de Pharmacie; Université Laval; Quebec Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec; Université Laval; Québec Canada
| | - Frédéric Calon
- Faculté de Pharmacie; Université Laval; Quebec Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec; Université Laval; Québec Canada
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218
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Oil Palm Phenolics Inhibit the In Vitro Aggregation of β-Amyloid Peptide into Oligomeric Complexes. Int J Alzheimers Dis 2018; 2018:7608038. [PMID: 29666700 PMCID: PMC5831689 DOI: 10.1155/2018/7608038] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 11/23/2017] [Accepted: 12/07/2017] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease is a severe neurodegenerative disease characterized by the aggregation of amyloid-β peptide (Aβ) into toxic oligomers which activate microglia and astrocytes causing acute neuroinflammation. Multiple studies show that the soluble oligomers of Aβ42 are neurotoxic and proinflammatory, whereas the monomers and insoluble fibrils are relatively nontoxic. We show that Aβ42 aggregation is inhibited in vitro by oil palm phenolics (OPP), an aqueous extract from the oil palm tree (Elaeis guineensis). The data shows that OPP inhibits stacking of β-pleated sheets, which is essential for oligomerization. We demonstrate the inhibition of Aβ42 aggregation by (1) mass spectrometry; (2) Congo Red dye binding; (3) 2D-IR spectroscopy; (4) dynamic light scattering; (5) transmission electron microscopy; and (6) transgenic yeast rescue assay. In the yeast rescue assay, OPP significantly reduces the cytotoxicity of aggregating neuropeptides in yeast genetically engineered to overexpress these peptides. The data shows that OPP inhibits (1) the aggregation of Aβ into oligomers; (2) stacking of β-pleated sheets; and (3) fibrillar growth and coalescence. These inhibitory effects prevent the formation of neurotoxic oligomers and hold potential as a means to reduce neuroinflammation and neuronal death and thereby may play some role in the prevention or treatment of Alzheimer's disease.
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219
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Novel targets in Alzheimer's disease: A special focus on microglia. Pharmacol Res 2018; 130:402-413. [PMID: 29391235 DOI: 10.1016/j.phrs.2018.01.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 01/12/2018] [Accepted: 01/26/2018] [Indexed: 02/07/2023]
Abstract
Several years after the intriguing novelty in the β-amyloid (Aβ) cascade hypothesis, where the Aβ oligomers emerged as the most detrimental species in the neuropathogenic process of Alzheimer's disease (AD) in place of fibrillar plaques, more recently innate immune system have come on stage as the other prominent factor. Neuroinflammation apparently contributes to AD eziopathogenesis, in large part through overactivation of microglia cells. Genetic and experimental studies strongly support the contribution of the immune system to increasing the risk of AD and participating in its progression. Besides the central immune response mediated by resident microglial cells, peripheral immune challenges may have profound negative effects on brain physiology as well, such as those originating from the gut microbiota. Despite the initial immune response to defend the organism, perpetuation seemingly turns into a chronic detrimental phenomenon that contributes to neuronal dysfunction and exacerbation of the disease. Several new immune-druggable targets are now under investigation, but much still remains to be defined about their precise role and whether and how their physiological activity changes in the injurious context of AD. From a therapeutic perspective, we can undoubtedly consider that AD is no longer solely an Aβ pathology, but rather a multifaceted disorder calling for multi-target therapies. New therapies fighting AD must still counteract Aβ but must also restore appropriate immune defences by tempering maladaptive factors and enabling beneficial responses.
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220
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Ribarič S. Peptides as Potential Therapeutics for Alzheimer's Disease. Molecules 2018; 23:E283. [PMID: 29385735 PMCID: PMC6017258 DOI: 10.3390/molecules23020283] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 01/26/2018] [Accepted: 01/28/2018] [Indexed: 12/22/2022] Open
Abstract
Intracellular synthesis, folding, trafficking and degradation of proteins are controlled and integrated by proteostasis. The frequency of protein misfolding disorders in the human population, e.g., in Alzheimer's disease (AD), is increasing due to the aging population. AD treatment options are limited to symptomatic interventions that at best slow-down disease progression. The key biochemical change in AD is the excessive accumulation of per-se non-toxic and soluble amyloid peptides (Aβ(1-37/44), in the intracellular and extracellular space, that alters proteostasis and triggers Aβ modification (e.g., by reactive oxygen species (ROS)) into toxic intermediate, misfolded soluble Aβ peptides, Aβ dimers and Aβ oligomers. The toxic intermediate Aβ products aggregate into progressively less toxic and less soluble protofibrils, fibrils and senile plaques. This review focuses on peptides that inhibit toxic Aβ oligomerization, Aβ aggregation into fibrils, or stabilize Aβ peptides in non-toxic oligomers, and discusses their potential for AD treatment.
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Affiliation(s)
- Samo Ribarič
- Institute of Pathophysiology, Faculty of Medicine, Zaloška 4, SI-1000 Ljubljana, Slovenia.
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221
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Hofrichter J, Krohn M, Schumacher T, Lange C, Feistel B, Walbroel B, Pahnke J. Sideritis spp. Extracts Enhance Memory and Learning in Alzheimer's β-Amyloidosis Mouse Models and Aged C57Bl/6 Mice. J Alzheimers Dis 2018; 53:967-80. [PMID: 27258424 PMCID: PMC4981905 DOI: 10.3233/jad-160301] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Nowadays, Alzheimer’s disease is the most prevalent epiphenomenon of the aging population. Although soluble amyloid-β (Aβ) species (monomers, oligomers) are recognized triggers of the disease, no therapeutic approach is able to stop it. Herbal medicines are used to treat different diseases in many regions of the world. On the Balkan Peninsula, at the eastern Mediterranean Sea, and adjacent regions, Sideritis species are used as traditional medicine to prevent age-related problems in elderly. To evaluate this traditional knowledge in controlled experiments, we tested extracts of two commonly used Sideritis species, Sideritis euboea and Sideritis scardica, with regard to their effects on cognition in APP-transgenic and aged, non-transgenic C57Bl/6 mice. Additionally, histomorphological and biochemical changes associated with Aβ deposition and treatment were assessed. We found that daily oral treatment with Sideritis spp. extracts highly enhanced cognition in aged, non-transgenic as well as in APP-transgenic mice, an effect that was even more pronounced when extracts of both species were applied in combination. The treatment strongly reduced Aβ42 load in APP-transgenic mice, accompanied by increased phagocytic activity of microglia, and increased expression of the α-secretase ADAM10. Moreover, the treatment was able to fully rescue neuronal loss of APP-transgenic mice to normal levels as seen in non-transgenic controls. Having the traditional knowledge in mind, our results imply that treatment with Sideritis spp. extracts might be a potent, well-tolerated option for treating symptoms of cognitive impairment in elderly and with regard to Alzheimer’s disease by affecting its most prominent hallmarks: Aβ pathology and cognitive decline.
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Affiliation(s)
| | - Markus Krohn
- University of Oslo (UiO) and Oslo University Hospital (OUS), Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, Oslo, Norway.,University of Rostock, Department of Neurology, Rostock, Germany
| | - Toni Schumacher
- University of Rostock, Department of Neurology, Rostock, Germany
| | - Cathleen Lange
- University of Rostock, Department of Neurology, Rostock, Germany
| | | | | | - Jens Pahnke
- University of Oslo (UiO) and Oslo University Hospital (OUS), Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, Oslo, Norway.,University of Rostock, Department of Neurology, Rostock, Germany.,University of Lübeck, Lübeck (LIED), Lübeck, Germany.,Leibniz Institute for Plant Biochemistry (IPB), Halle, Germany
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222
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Hsiao YH, Chang CH, Gean PW. Impact of social relationships on Alzheimer's memory impairment: mechanistic studies. J Biomed Sci 2018; 25:3. [PMID: 29325565 PMCID: PMC5764000 DOI: 10.1186/s12929-018-0404-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 01/02/2018] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) is characterized by progressive memory and neuronal loss culminating in cognitive impairment that not only affects a person's living ability but also becomes a society's as well as a family's economic burden. AD is the most common form of dementia in older persons. It is expected that the number of people with AD dementia will increase dramatically in the next 30 years, projecting to 75 million in 2030 and 131.5 million in 2050 worldwide. So far, no sufficient evidence is available to support that any medicine is able to prevent or reverse the progression of the disease. Early studies have shown that social environment, particularly social relationships, can affect one's behavior and mental health. A study analyzing the correlation between loneliness and risk of developing AD revealed that lonely persons had higher risk of AD compared with persons who were not lonely. On the other hand, it has been reported that we can prevent cognitive decline and delay the onset of AD if we keep mentally active and frequently participate in social activities. In this review, we focus on the impact of social behaviors on the progression of cognitive deficit in animal models of AD with a particular emphasis on a mechanistic scheme that explains how social isolation exacerbates cognitive impairment and how social interaction with conspecifics rescues AD patients' memory deficit.
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Affiliation(s)
- Ya-Hsin Hsiao
- Department of Pharmacology, College of Medicine, National Cheng Kung University, No.1, Ta-Shieh Rd, Tainan City, 701, Taiwan
| | - Chih-Hua Chang
- Department of Pharmacology, College of Medicine, National Cheng Kung University, No.1, Ta-Shieh Rd, Tainan City, 701, Taiwan
| | - Po-Wu Gean
- Department of Pharmacology, College of Medicine, National Cheng Kung University, No.1, Ta-Shieh Rd, Tainan City, 701, Taiwan.
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223
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Kosenko EA, Tikhonova LA, Montoliu C, Barreto GE, Aliev G, Kaminsky YG. Metabolic Abnormalities of Erythrocytes as a Risk Factor for Alzheimer's Disease. Front Neurosci 2018; 11:728. [PMID: 29354027 PMCID: PMC5760569 DOI: 10.3389/fnins.2017.00728] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/13/2017] [Indexed: 01/02/2023] Open
Abstract
Alzheimer's disease (AD) is a slowly progressive, neurodegenerative disorder of uncertain etiology. According to the amyloid cascade hypothesis, accumulation of non-soluble amyloid β peptides (Aβ) in the Central Nervous System (CNS) is the primary cause initiating a pathogenic cascade leading to the complex multilayered pathology and clinical manifestation of the disease. It is, therefore, not surprising that the search for mechanisms underlying cognitive changes observed in AD has focused exclusively on the brain and Aβ-inducing synaptic and dendritic loss, oxidative stress, and neuronal death. However, since Aβ depositions were found in normal non-demented elderly people and in many other pathological conditions, the amyloid cascade hypothesis was modified to claim that intraneuronal accumulation of soluble Aβ oligomers, rather than monomer or insoluble amyloid fibrils, is the first step of a fatal cascade in AD. Since a characteristic reduction of cerebral perfusion and energy metabolism occurs in patients with AD it is suggested that capillary distortions commonly found in AD brain elicit hemodynamic changes that alter the delivery and transport of essential nutrients, particularly glucose and oxygen to neuronal and glial cells. Another important factor in tissue oxygenation is the ability of erythrocytes (red blood cells, RBC) to transport and deliver oxygen to tissues, which are first of all dependent on the RBC antioxidant and energy metabolism, which finally regulates the oxygen affinity of hemoglobin. In the present review, we consider the possibility that metabolic and antioxidant defense alterations in the circulating erythrocyte population can influence oxygen delivery to the brain, and that these changes might be a primary mechanism triggering the glucose metabolism disturbance resulting in neurobiological changes observed in the AD brain, possibly related to impaired cognitive function. We also discuss the possibility of using erythrocyte biochemical aberrations as potential tools that will help identify a risk factor for AD.
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Affiliation(s)
- Elena A Kosenko
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Lyudmila A Tikhonova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Carmina Montoliu
- Fundación Investigación Hospital Clínico, INCLIVA Instituto Investigación Sanitaria, Valencia, Spain
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia.,Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Gjumrakch Aliev
- GALLY International Biomedical Research Institute Inc., San Antonio, TX, United States
| | - Yury G Kaminsky
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia
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224
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Sekioka R, Honjo E, Honda S, Fuji H, Akashiba H, Mitani Y, Yamasaki S. Discovery of novel scaffolds for γ-secretase modulators without an arylimidazole moiety. Bioorg Med Chem 2018; 26:435-442. [DOI: 10.1016/j.bmc.2017.11.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/28/2017] [Accepted: 11/30/2017] [Indexed: 01/15/2023]
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225
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Hey JA, Kocis P, Hort J, Abushakra S, Power A, Vyhnálek M, Yu JY, Tolar M. Discovery and Identification of an Endogenous Metabolite of Tramiprosate and Its Prodrug ALZ-801 that Inhibits Beta Amyloid Oligomer Formation in the Human Brain. CNS Drugs 2018; 32:849-861. [PMID: 30076539 PMCID: PMC6153967 DOI: 10.1007/s40263-018-0554-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND ALZ-801 is an oral, small-molecule inhibitor of beta amyloid (Aβ) oligomer formation in clinical development for Alzheimer's disease (AD). ALZ-801 is a prodrug of tramiprosate with improved pharmacokinetic properties and gastrointestinal tolerability. During clinical studies, we discovered that the primary metabolite of tramiprosate and its prodrug ALZ-801, 3-sulfopropanoic acid (3-SPA), is an endogenous molecule in the human brain and present in the cerebrospinal fluid (CSF) of patients with AD and other neurodegenerative brain diseases. OBJECTIVE The objectives of this research were to (1) identify and confirm the presence of 3-SPA in CSF samples from elderly, drug-naïve patients with memory deficits; (2) quantify the levels of 3-SPA in the CSF of patients with AD from tramiprosate phase III North American (NA) trial; (3) evaluate the in vitro anti-Aβ42 oligomer activity of 3-SPA; and (4) characterize the pharmacokinetics and brain-penetration properties of 3-SPA. METHODS Lumbar CSF samples from 64 drug-naïve patients with cognitive deficits (Mini-Mental State Examination [MMSE] score range 15-30) and six patients with AD treated with tramiprosate 150 mg twice daily in the phase III trial, at week 78, were analyzed. We used liquid chromatography-tandem mass spectrometry to confirm the structural molecular identity of endogenous 3-SPA with a 3-SPA reference standard and ion-mobility spectrometry-mass spectrometry with molecular dynamics to characterize interactions of 3-SPA with Aβ42 monomers, and the resultant conformational alterations. Rat studies using oral (30 mg/kg) and intravenous (10 mg/kg) doses were conducted to characterize the pharmacokinetic properties and brain penetration of 3-SPA. RESULTS We confirmed the presence of 3-SPA in the CSF of drug-naïve patients with cognitive deficits (mean concentration 11.7 ± 4.3 nM). The mean concentration of 3-SPA in patients with AD treated with tramiprosate was 135 ± 51 nM. In vitro studies revealed a multi-ligand interaction of 3-SPA with monomeric Aβ42 that inhibits the aggregation of Aβ42 into small oligomers. Comparisons of the molecular interactions of tramiprosate and 3-SPA with Aβ42 are also presented. Furthermore, in rat preclinical studies, 3-SPA displayed 100% oral bioavailability and 25% brain penetration, indicating that the metabolite is well absorbed and crosses the blood-brain barrier. CONCLUSIONS We confirmed the endogenous presence of 3-SPA, the major metabolite of tramiprosate, in the CSF of drug-naïve elderly patients with memory deficits due to AD and a variety of other neurodegenerative disorders. The levels of 3-SPA were up to 12.6-fold greater in patients with AD receiving tramiprosate than in drug-naïve patients. In addition, we showed that 3-SPA has potent anti-Aβ oligomer activity, inhibiting aggregation of Aβ42 into small oligomers with efficacy comparable to that of tramiprosate. 3-SPA displays excellent oral availability and brain penetration in rats, suggesting that the higher CSF concentrations of 3-SPA in the human brain after oral administration of ALZ-801 or tramiprosate (and subsequent conversion to 3-SPA) result from the penetration of the metabolite into the central nervous system. These data suggest that 3-SPA is an endogenous agent with potential activity stabilizing the conformational flexibility of Aβ monomers that, in turn, inhibit Aβ misfolding and formation of soluble toxic Aβ oligomers in humans, thereby preventing the initial pathogenic step in the progression of AD. Clinical improvements observed in patients with AD carrying the ε4 allele of the apolipoprotein E gene in tramiprosate phase III studies may in part be explained by the therapeutic effects of excess levels of the metabolite in the brains of these patients. The potential protective role of 3-SPA in AD pathogenesis, as well as its therapeutic role in AD and other neurodegenerative disorders, warrants further investigation.
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Affiliation(s)
- John A. Hey
- Alzheon, Inc, 111 Speen Street Suite 306, Framingham, MA 01701 USA
| | - Petr Kocis
- Alzheon, Inc, 111 Speen Street Suite 306, Framingham, MA 01701 USA
| | - Jakub Hort
- 0000 0004 0608 7557grid.412752.7International Clinical Research Centre, St. Anne’s University Hospital Brno, Brno, Czech Republic ,0000 0004 1937 116Xgrid.4491.8Department of Neurology, Cognitive Center, 2nd Faculty of Medicine, Motol University Hospital, Charles University, Prague, Czech Republic
| | - Susan Abushakra
- Alzheon, Inc, 111 Speen Street Suite 306, Framingham, MA 01701 USA
| | - Aidan Power
- Alzheon, Inc, 111 Speen Street Suite 306, Framingham, MA 01701 USA
| | - Martin Vyhnálek
- 0000 0004 0608 7557grid.412752.7International Clinical Research Centre, St. Anne’s University Hospital Brno, Brno, Czech Republic ,0000 0004 1937 116Xgrid.4491.8Department of Neurology, Cognitive Center, 2nd Faculty of Medicine, Motol University Hospital, Charles University, Prague, Czech Republic
| | - Jeremy Y. Yu
- Alzheon, Inc, 111 Speen Street Suite 306, Framingham, MA 01701 USA
| | - Martin Tolar
- Alzheon, Inc, 111 Speen Street Suite 306, Framingham, MA 01701 USA
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226
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Marsh J, Alifragis P. Synaptic dysfunction in Alzheimer's disease: the effects of amyloid beta on synaptic vesicle dynamics as a novel target for therapeutic intervention. Neural Regen Res 2018; 13:616-623. [PMID: 29722304 PMCID: PMC5950662 DOI: 10.4103/1673-5374.230276] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The most prevalent form of dementia in the elderly is Alzheimer's disease. A significant contributing factor to the progression of the disease appears to be the progressive accumulation of amyloid-β42 (Aβ42), a small hydrophobic peptide. Unfortunately, attempts to develop therapies targeting the accumulation of Aβ42 have not been successful to treat or even slow down the disease. It is possible that this failure is an indication that targeting downstream effects rather than the accumulation of the peptide itself might be a more effective approach. The accumulation of Aβ42 seems to affect various aspects of physiological cell functions. In this review, we provide an overview of the evidence that implicates Aβ42 in synaptic dysfunction, with a focus on how it contributes to defects in synaptic vesicle dynamics and neurotransmitter release. We discuss data that provide new insights on the Aβ42 induced pathology of Alzheimer's disease and a more detailed understanding of its contribution to the synaptic deficiencies that are associated with the early stages of the disease. Although the precise mechanisms that trigger synaptic dysfunction are still under investigation, the available data so far has enabled us to put forward a model that could be used as a guide to generate new therapeutic targets for pharmaceutical intervention.
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Affiliation(s)
- Jade Marsh
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, UK
| | - Pavlos Alifragis
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, UK
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227
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Gao Q, Fang Y, Zhang S, Li HW, Yung KKL, Lai KWC. Biophysical Characteristics of Human Neuroblastoma Cell in Oligomeric $\beta $ -Amyloid (1–40) Cytotoxicity. IEEE Trans Nanobioscience 2018; 17:70-77. [DOI: 10.1109/tnb.2018.2800723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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228
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Bordeleau M, ElAli A, Rivest S. Severe chronic cerebral hypoperfusion induces microglial dysfunction leading to memory loss in APPswe/PS1 mice. Oncotarget 2017; 7:11864-80. [PMID: 26918610 PMCID: PMC4914254 DOI: 10.18632/oncotarget.7689] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 02/05/2016] [Indexed: 12/12/2022] Open
Abstract
Cerebral vasculature plays a key role in controlling brain homeostasis. Cerebral vasculature dysfunction, associated to irregularities in cerebral blood perfusion, has been proposed to directly contribute to Alzheimer's disease (AD) pathogenesis. More precisely, chronic cerebral hypoperfusion, which impairs brain homeostasis, was demonstrated to take place even before cognitive decline. However, the mechanisms underlying the implication of chronic cerebral hypoperfusion in AD pathogenesis remain elusive. Therefore, this study aims at investigating the role of severe chronic cerebral hypoperfusion (SCCH) in AD pathogenesis. For this purpose, SCCH was induced in young APPswe/PS1 in order to evaluate the progression of AD-like pathology in these mice. We observed that SCCH accelerated the cognitive decline of young APPswe/PS1 mice, which was associated with an increased amyloid plaque number in brain parenchyma. In addition, SCCH reduced the activity of extracellular signal-regulated kinases 1/2 (ERK1/2), which has been shown to play an important role in the adaptive responses of neurons. Importantly, SCCH impaired the function of microglial cells, which are implicated in amyloid-β (Aβ) elimination. In vitro approaches underlined the ability of a low-glucose microenvironment to decrease the general activity and phagocytic capacity of microglia. By using a new model of SCCH, our study unravels new insights into the implication of severe chronic cerebral hypoperfusion in AD pathogenesis, mainly by altering microglial cell activity and consequently Aβ clearance.
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Affiliation(s)
- Maude Bordeleau
- Neuroscience Laboratory, CHU de Québec Research Center (CHUL), Department of Molecular Medicine, Faculty of Medicine, Laval University, Québec, Canada
| | - Ayman ElAli
- Neuroscience Laboratory, CHU de Québec Research Center (CHUL), Department of Psychiatry and Neuroscience, Faculty of Medicine, Laval University, Québec, Canada
| | - Serge Rivest
- Neuroscience Laboratory, CHU de Québec Research Center (CHUL), Department of Molecular Medicine, Faculty of Medicine, Laval University, Québec, Canada
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229
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Bai Y, Li M, Zhou Y, Ma L, Qiao Q, Hu W, Li W, Wills ZP, Gan WB. Abnormal dendritic calcium activity and synaptic depotentiation occur early in a mouse model of Alzheimer's disease. Mol Neurodegener 2017; 12:86. [PMID: 29137651 PMCID: PMC5686812 DOI: 10.1186/s13024-017-0228-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 11/02/2017] [Indexed: 12/31/2022] Open
Abstract
Background Alzheimer’s disease (AD) is characterized by amyloid deposition, tangle formation as well as synapse loss. Synaptic abnormalities occur early in the pathogenesis of AD. Identifying early synaptic abnormalities and their underlying mechanisms is likely important for the prevention and treatment of AD. Methods We performed in vivo two-photon calcium imaging to examine the activities of somas, dendrites and dendritic spines of layer 2/3 pyramidal neurons in the primary motor cortex in the APPswe/PS1dE9 mouse model of AD and age-matched wild type control mice. We also performed calcium imaging to determine the effect of Aβ oligomers on dendritic calcium activity. In addition, structural and functional two-photon imaging were used to examine the link between abnormal dendritic calcium activity and changes in dendritic spine size in the AD mouse model. Results We found that somatic calcium activities of layer 2/3 neurons were significantly lower in the primary motor cortex of 3-month-old APPswe/PS1dE9 mice than in wild type mice during quiet resting, but not during running on a treadmill. Notably, a significantly larger fraction of apical dendrites of layer 2/3 pyramidal neurons showed calcium transients with abnormally long duration and high peak amplitudes during treadmill running in AD mice. Administration of Aβ oligomers into the brain of wild type mice also induced abnormal dendritic calcium transients during running. Furthermore, we found that the activity and size of dendritic spines were significantly reduced on dendritic branches with abnormally prolonged dendritic calcium transients in AD mice. Conclusion Our findings show that abnormal dendritic calcium transients and synaptic depotentiation occur before amyloid plaque formation in the motor cortex of the APPswe/PS1dE9 mouse model of AD. Dendritic calcium transients with abnormally long durations and high amplitudes could be induced by soluble Aβ oligomers and contribute to synaptic deficits in the early pathogenesis of AD. Electronic supplementary material The online version of this article (10.1186/s13024-017-0228-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yang Bai
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.,Skirball Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, 10016, USA
| | - Miao Li
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Yanmei Zhou
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.,Skirball Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, 10016, USA
| | - Lei Ma
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Qian Qiao
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Wanling Hu
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Wei Li
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | | | - Wen-Biao Gan
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China. .,Skirball Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, 10016, USA.
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Oxalate-curcumin-based probe for micro- and macroimaging of reactive oxygen species in Alzheimer's disease. Proc Natl Acad Sci U S A 2017; 114:12384-12389. [PMID: 29109280 DOI: 10.1073/pnas.1706248114] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD) is an irreversible neurodegenerative disorder that has a progression that is closely associated with oxidative stress. It has long been speculated that the reactive oxygen species (ROS) level in AD brains is much higher than that in healthy brains. However, evidence from living beings is scarce. Inspired by the "chemistry of glow stick," we designed a near-IR fluorescence (NIRF) imaging probe, termed CRANAD-61, for sensing ROS to provide evidence at micro- and macrolevels. In CRANAD-61, an oxalate moiety was utilized to react with ROS and to consequentially produce wavelength shifting. Our in vitro data showed that CRANAD-61 was highly sensitive and rapidly responsive to various ROS. On reacting with ROS, its excitation and emission wavelengths significantly shifted to short wavelengths, and this shifting could be harnessed for dual-color two-photon imaging and transformative NIRF imaging. In this report, we showed that CRANAD-61 could be used to identify "active" amyloid beta (Aβ) plaques and cerebral amyloid angiopathy (CAA) surrounded by high ROS levels with two-photon imaging (microlevel) and to provide relative total ROS concentrations in AD brains via whole-brain NIRF imaging (macrolevel). Lastly, we showed that age-related increases in ROS levels in AD brains could be monitored with our NIRF imaging method. We believe that our imaging with CRANAD-61 could provide evidence of ROS at micro- and macrolevels and could be used for monitoring ROS changes under various AD pathological conditions and during drug treatment.
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231
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Brunner D, Flunkert S, Neddens J, Duller S, Scopes D, Treherne J, Hutter-Paier B. SEN1500, a novel oral amyloid-β aggregation inhibitor, attenuates brain pathology in a mouse model of Alzheimer’s disease. Neurosci Lett 2017; 660:96-102. [DOI: 10.1016/j.neulet.2017.09.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 09/01/2017] [Accepted: 09/12/2017] [Indexed: 01/10/2023]
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232
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Roher AE, Kokjohn TA, Clarke SG, Sierks MR, Maarouf CL, Serrano GE, Sabbagh MS, Beach TG. APP/Aβ structural diversity and Alzheimer's disease pathogenesis. Neurochem Int 2017; 110:1-13. [PMID: 28811267 PMCID: PMC5688956 DOI: 10.1016/j.neuint.2017.08.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/25/2017] [Accepted: 08/11/2017] [Indexed: 02/01/2023]
Abstract
The amyloid cascade hypothesis of Alzheimer's disease (AD) proposes amyloid- β (Aβ) is a chief pathological element of dementia. AD therapies have targeted monomeric and oligomeric Aβ 1-40 and 1-42 peptides. However, alternative APP proteolytic processing produces a complex roster of Aβ species. In addition, Aβ peptides are subject to extensive posttranslational modification (PTM). We propose that amplified production of some APP/Aβ species, perhaps exacerbated by differential gene expression and reduced peptide degradation, creates a diverse spectrum of modified species which disrupt brain homeostasis and accelerate AD neurodegeneration. We surveyed the literature to catalog Aβ PTM including species with isoAsp at positions 7 and 23 which may phenocopy the Tottori and Iowa Aβ mutations that result in early onset AD. We speculate that accumulation of these alterations induce changes in secondary and tertiary structure of Aβ that favor increased toxicity, and seeding and propagation in sporadic AD. Additionally, amyloid-β peptides with a pyroglutamate modification at position 3 and oxidation of Met35 make up a substantial portion of sporadic AD amyloid deposits. The intrinsic physical properties of these species, including resistance to degradation, an enhanced aggregation rate, increased neurotoxicity, and association with behavioral deficits, suggest their emergence is linked to dementia. The generation of specific 3D-molecular conformations of Aβ impart unique biophysical properties and a capacity to seed the prion-like global transmission of amyloid through the brain. The accumulation of rogue Aβ ultimately contributes to the destruction of vascular walls, neurons and glial cells culminating in dementia. A systematic examination of Aβ PTM and the analysis of the toxicity that they induced may help create essential biomarkers to more precisely stage AD pathology, design countermeasures and gauge the impacts of interventions.
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Affiliation(s)
- Alex E Roher
- Division of Neurobiology, Barrow Neurological Institute, Phoenix, AZ 85013, USA; Division of Clinical Education, Midwestern University, Glendale, AZ 85308, USA.
| | - Tyler A Kokjohn
- Department of Microbiology, Midwestern University, Glendale, AZ 85308, USA
| | - Steven G Clarke
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, Los Angeles CA 90095-1569, USA
| | - Michael R Sierks
- Department of Chemical Engineering, Arizona State University, Tempe, AZ 85287-6106, USA
| | - Chera L Maarouf
- Laboratory of Neuropathology, Banner Sun Health Research Institute, Sun City, AZ 85351, USA
| | - Geidy E Serrano
- Laboratory of Neuropathology, Banner Sun Health Research Institute, Sun City, AZ 85351, USA
| | - Marwan S Sabbagh
- Alzheimer's and Memory Disorders Division, Barrow Neurological Institute, Phoenix, AZ 85013, USA
| | - Thomas G Beach
- Laboratory of Neuropathology, Banner Sun Health Research Institute, Sun City, AZ 85351, USA
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233
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Li Y, Yang J, Liu H, Yang J, Du L, Feng H, Tian Y, Cao J, Ran C. Tuning the stereo-hindrance of a curcumin scaffold for the selective imaging of the soluble forms of amyloid beta species. Chem Sci 2017; 8:7710-7717. [PMID: 29568434 PMCID: PMC5851342 DOI: 10.1039/c7sc02050c] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 09/13/2017] [Indexed: 12/19/2022] Open
Abstract
Amyloid peptides and proteins are associated with the pathologies of numerous diseases. In the progression of a disease, amyloids exist in soluble and insoluble forms, which are the dominant species at different stages of the disease and they have different degrees of toxicity. However, differentiating between the soluble and insoluble forms is very challenging with small molecule probes due to multiple obstacles that need to be overcome. Inspired by the recognition principle of antibodies for sAβ, we hypothesized that the accessibility/tightness of soluble and insoluble amyloids could be utilized to design imaging probes to recognize different amyloid forms and the stereo-hindrance tuning strategy could be used to design imaging probes for selectively detecting the soluble amyloid beta (sAβ) species in Alzheimer's disease (AD). Herein, we demonstrated that tuning the stereo-hindrance of the phenoxy-alkyl chains at the 4-position of a curcumin scaffold could lead to certain selectivity for sAβ over insoluble Aβs (insAβ). Among the designed compounds, CRANAD-102 showed a 68-fold higher affinity for sAβ than for insAβ (7.5 ± 10 nM vs. 505.9 ± 275.9 nM). Moreover, our imaging data indicated that CRANAD-102 was indeed capable of detecting sAβ in vivo using 4 month old APP/PS1 mice, in which sAβ is the predominant species in the brain. In addition, we also demonstrated that CRANAD-102 could be used to monitor the increase in sAβ loading from the ages of 4 months old to 12 months old. We believe that CRANAD-102 can be a useful probe for selectively detecting sAβ species in AD and that our probe designing strategy can be applied to other amyloids and will have tremendous impact on AD drug development and other amyloid research.
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Affiliation(s)
- Yuyan Li
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital/Harvard Medical School , Charlestown , Massachusetts 02129 , USA
- School of Pharmacy , China Pharmaceutical University , Nanjing , 210009 , China
| | - Jian Yang
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital/Harvard Medical School , Charlestown , Massachusetts 02129 , USA
- School of Pharmacy , China Pharmaceutical University , Nanjing , 210009 , China
| | - Hongwu Liu
- School of Pharmacy , China Pharmaceutical University , Nanjing , 210009 , China
| | - Jing Yang
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital/Harvard Medical School , Charlestown , Massachusetts 02129 , USA
- College of Pharmaceutical Sciences , Soochow University , Suzhou , 215006 , China
| | - Lei Du
- School of Pharmacy , China Pharmaceutical University , Nanjing , 210009 , China
| | - Haiwei Feng
- School of Pharmacy , China Pharmaceutical University , Nanjing , 210009 , China
| | - Yanli Tian
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital/Harvard Medical School , Charlestown , Massachusetts 02129 , USA
- Department of Parasitology , Zhongshan School of Medicine , Sun Yat-Sen University , Guangzhou , P. R. China
| | - Jianqin Cao
- School of Pharmacy , China Pharmaceutical University , Nanjing , 210009 , China
| | - Chongzhao Ran
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital/Harvard Medical School , Charlestown , Massachusetts 02129 , USA
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234
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Brody AH, Strittmatter SM. Synaptotoxic Signaling by Amyloid Beta Oligomers in Alzheimer's Disease Through Prion Protein and mGluR5. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 82:293-323. [PMID: 29413525 PMCID: PMC5835229 DOI: 10.1016/bs.apha.2017.09.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Alzheimer's disease (AD) represents an impending global health crisis, yet the complexity of AD pathophysiology has so far precluded the development of any interventions to successfully slow or halt AD progression. It is clear that accumulation of Amyloid-beta (Aβ) peptide triggers progressive synapse loss to cause AD symptoms. Once initiated by Aβ, disease progression is complicated and accelerated by inflammation and by tau pathology. The recognition that Aβ peptide assumes multiple distinct states and that soluble oligomeric species (Aβo) are critical for synaptic damage is central to molecular understanding of AD. This knowledge has led to the identification of specific Aβo receptors, such as cellular prion protein (PrPC), mediating synaptic toxicity and neuronal dysfunction. The identification of PrPC as an Aβo receptor has illuminated an Aβo-induced signaling cascade involving mGluR5, Fyn, and Pyk2 that links Aβ and tau pathologies. This pathway provides novel potential therapeutic targets for disease-modifying AD therapy. Here, we discuss the methods by which several putative Aβo receptors were identified. We also offer an in-depth examination of the known molecular mechanisms believed to mediate Aβo-induced synaptic dysfunction, toxicity, and memory dysfunction.
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Affiliation(s)
- A Harrison Brody
- Program in Cellular Neuroscience, Neurodegeneration & Repair, Yale University School of Medicine, New Haven, CT, United States; Yale University, New Haven, CT, United States
| | - Stephen M Strittmatter
- Program in Cellular Neuroscience, Neurodegeneration & Repair, Yale University School of Medicine, New Haven, CT, United States; Yale University, New Haven, CT, United States.
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235
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Active Immunization Against hIAPP Oligomers Ameliorates the Diabetes- Associated Phenotype in a Transgenic Mice Model. Sci Rep 2017; 7:14031. [PMID: 29070797 PMCID: PMC5656574 DOI: 10.1038/s41598-017-14311-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 10/09/2017] [Indexed: 01/09/2023] Open
Abstract
Type 2 diabetes is characterized by insulin tolerance in target cells followed by a reduction of pancreatic β-cell mass. Islet amyloid polypeptide oligomeric assemblies were shown to contribute to β-cell apoptosis by forming discrete pores that destabilize the cellular membrane. We previously characterized α-helical cytotoxic islet amyloid polypeptide oligomers which interact with cell membranes, following a complete internalization that leads to cellular apoptosis. Moreover, antibodies which bind the oligomers and neutralize the cytotoxicity were exclusively identified in the serum of type 2 diabetes patients. Here, we examined the usage of the newly characterized oligomers as an active immunization agent targeting amyloid self- assembly in a diabetes-associated phenotype transgenic mice model. Immunized transgenic mice showed an increase in hIAPP-antibody serum titer as well as improvement in diabetes-associated parameters. Lower fasting blood glucose levels, higher insulin, and lower islet amyloid polypeptide accumulation were observed. Furthermore, antibodies derived from the immunized mice reduced hIAPP oligomers cytotoxicity towards β-cells in a dose-dependent manner. This study highlights the significance of targeting the early amyloid self-assembly events for potential disease management. Furthermore, it demonstrates that α-helical oligomers conformers are valid epitope for the development of future immunization therapy.
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236
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Hoffmann F, Adler J, Chandra B, Mote KR, Bekçioğlu-Neff G, Sebastiani D, Huster D. Perturbation of the F19-L34 Contact in Amyloid β (1-40) Fibrils Induces Only Local Structural Changes but Abolishes Cytotoxicity. J Phys Chem Lett 2017; 8:4740-4745. [PMID: 28910107 DOI: 10.1021/acs.jpclett.7b02317] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We explored structural details of fibrils formed by a mutated amyloid β (Aβ(1-40)) peptide carrying a Phe19 to Lys19 mutation, which was shown to completely abolish the toxicity of the molecule. Computer models suggest that the positively charged Lys19 side chain is expelled from the hydrophobic fibril interior upon fibrillation. This can be accommodated by either a 180° flip of the entire lower β-strand (model M1) or local perturbations of the secondary structure in the direct vicinity of the mutated site (model M2). This is accompanied by the formation of a new salt bridge between Glu22 and Lys28 in model M1. Experimentally, a novel contact between Phe20 and Leu34 as well as the significant structural perturbation of residues 20-23 could be confirmed. However, the mutated fibrils do not show the formation of any salt bridges. This demonstrates that although morphologically very robust, local perturbations of the Aβ(1-40) sequence lead to moderate structural alterations with tremendous impact on the physiological importance of these aggregates, which may suggest alternative strategies for the development of a remedy against Alzheimer's disease.
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Affiliation(s)
- Felix Hoffmann
- Department of Chemistry, Martin-Luther Universität Halle-Wittenberg , von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany
| | - Juliane Adler
- Institute for Medical Physics and Biophysics, Leipzig University , Härtelstr. 16-18, 04107 Leipzig, Germany
| | - Bappaditya Chandra
- Tata Institute of Fundamental Research , Homi Bhabha Road, Colaba, Mumbai 400 005, India
| | - Kaustubh R Mote
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research , 21 Brundavan Colony, Narsingi, Hyderabad 500 075, India
| | - Gül Bekçioğlu-Neff
- Department of Chemistry, Martin-Luther Universität Halle-Wittenberg , von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany
| | - Daniel Sebastiani
- Department of Chemistry, Martin-Luther Universität Halle-Wittenberg , von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, Leipzig University , Härtelstr. 16-18, 04107 Leipzig, Germany
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237
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Gallardo G, Holtzman DM. Antibody Therapeutics Targeting Aβ and Tau. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a024331. [PMID: 28062555 DOI: 10.1101/cshperspect.a024331] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The astonishing findings that active and passive immunization against amyloid-β (Aβ) in mouse models of Alzheimer's disease (AD) dramatically decreased amyloid burden led to a rapid initiation of human clinical trials with much enthusiasm. However, methodological issues and adverse effects relating to these clinical trials arose, challenging the effectiveness and safety of these reagents. Efforts are now underway to develop safer immunotherapeutic approaches toward Aβ and the treatment of individuals at risk for AD before or in the earliest stages of cognitive decline with new hopes. Furthermore, several studies have shown tau as a potential immunotherapeutic target for the treatment of tauopathy-related diseases including frontotemporal lobar dementia (FTLD). Both active and passive immunization targeting tau in mouse models of tauopathy effectively decreased tau pathology while improving cognitive performance. These preclinical studies have highlighted tau as an alternative target with much anticipation of clinical trials to be undertaken.
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Affiliation(s)
- Gilbert Gallardo
- Department of Neurology, Hope Center for Neurological Disorders, and Knight Alzheimer's Disease Research Center, Washington University, St. Louis, Missouri 63110
| | - David M Holtzman
- Department of Neurology, Hope Center for Neurological Disorders, and Knight Alzheimer's Disease Research Center, Washington University, St. Louis, Missouri 63110
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238
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Van Dam D, Vermeiren Y, Dekker AD, Naudé PJW, Deyn PPD. Neuropsychiatric Disturbances in Alzheimer's Disease: What Have We Learned from Neuropathological Studies? Curr Alzheimer Res 2017; 13:1145-64. [PMID: 27137218 PMCID: PMC5070416 DOI: 10.2174/1567205013666160502123607] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/04/2016] [Accepted: 04/27/2016] [Indexed: 12/16/2022]
Abstract
Neuropsychiatric symptoms (NPS) are an integral part of the dementia syndrome and were therefore recently included in the core diagnostic criteria of dementia. The near universal prevalence of NPS in Alzheimer's disease (AD), combined with their disabling effects on patients and caregivers, is contrasted by the fact that few effective and safe treatments exist, which is in part to be attributed to our incomplete understanding of the neurobiology of NPS. In this review, we describe the pathological alterations typical for AD, including spreading and evolution of burden, effect on the molecular and cellular integrity, functional consequences and atrophy of NPS-relevant brain regions and circuits in correlation with specific NPS assessments. It is thereby clearly established that NPS are fundamental expressions of the underlying neurodegenerative brain disease and not simply reflect the patients' secondary response to their illness. Neuropathological studies, moreover, include a majority of end-stage patient samples, which may not correctly represent the pathophysiological environment responsible for particular NPS that may already be present in an early stage, or even prior to AD diagnosis. The burdensome nature and high prevalence of NPS, in combination with the absence of effective and safe pharmacotherapies, provide a strong incentive to continue neuropathological and neurochemical, as well as imaging and other relevant approaches to further improve our apprehension of the neurobiology of NPS.
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Affiliation(s)
| | | | | | | | - Peter P De Deyn
- Laboratory of Neurochemistry and Behaviour, Institute Born-Bunge, Department of Biomedical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, and, Faculty of Medical and Health Care Sciences, University of Antwerp, Universiteitsplein 1, BE-2610 Wilrijk (Antwerp), Belgium
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239
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Hui S, Yang Y, Peng WJ, Sheng CX, Gong W, Chen S, Xu PP, Wang Z. Protective effects of Bushen Tiansui decoction on hippocampal synapses in a rat model of Alzheimer's disease. Neural Regen Res 2017; 12:1680-1686. [PMID: 29171433 PMCID: PMC5696849 DOI: 10.4103/1673-5374.217347] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2017] [Indexed: 12/26/2022] Open
Abstract
Bushen Tiansui decoction is composed of six traditional Chinese medicines: Herba Epimedii, Radix Polygoni multiflori, Plastrum testudinis, Fossilia Ossis Mastodi, Radix Polygalae, and Rhizoma Acorus tatarinowii. Because Bushen Tiansui decoction is effective against amyloid beta (Aβ) toxicity, we hypothesized that it would reduce hippocampal synaptic damage and improve cognitive function in Alzheimer's disease. To test this hypothesis, we used a previously established animal model of Alzheimer's disease, that is, microinjection of aggregated Aβ25-35 into the bilateral brain ventricles of Sprague-Dawley rats. We found that long-term (28 days) oral administration of Bushen Tiansui decoction (0.563, 1.688, and 3.375 g/mL; 4 mL/day) prevented synaptic loss in the hippocampus and increased the expression levels of synaptic proteins, including postsynaptic density protein 95, the N-methyl-D-aspartate receptor 2B subunit, and Shank1. These results suggested that Bushen Tiansui decoction can protect synapses by maintaining the expression of these synaptic proteins. Bushen Tiansui decoction also ameliorated measures reflecting spatial learning and memory deficits that were observed in the Morris water maze (i.e., increased the number of platform crossings and the amount of time spent in the target quadrant and decreased escape latency) following intraventricular injections of aggregated Aβ25-35 compared with those measures in untreated Aβ25-35-injected rats. Overall, these results provided evidence that further studies on the prevention and treatment of dementia with this traditional Chinese medicine are warranted.
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Affiliation(s)
- Shan Hui
- Department of Integrated Chinese and Western Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
- Department of Geriatric Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Yu Yang
- Department of Geriatric Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Wei-jun Peng
- Department of Integrated Chinese and Western Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Chen-xia Sheng
- Department of Integrated Chinese and Western Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Wei Gong
- Department of Integrated Chinese and Western Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Shuai Chen
- Department of Integrated Chinese and Western Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Pan-pan Xu
- Department of Integrated Chinese and Western Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Zhe Wang
- Department of Integrated Chinese and Western Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
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240
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Jeong S. Molecular and Cellular Basis of Neurodegeneration in Alzheimer's Disease. Mol Cells 2017; 40:613-620. [PMID: 28927263 PMCID: PMC5638769 DOI: 10.14348/molcells.2017.0096] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/06/2017] [Accepted: 08/16/2017] [Indexed: 12/25/2022] Open
Abstract
The most common form of senile dementia is Alzheimer's disease (AD), which is characterized by the extracellular deposition of amyloid β-peptide (Aβ) plaques and the intracellular formation of neurofibrillary tangles (NFTs) in the cerebral cortex. Tau abnormalities are commonly observed in many neurodegenerative diseases including AD, Parkinson's disease, and Pick's disease. Interestingly, tau-mediated formation of NFTs in AD brains shows better correlation with cognitive impairment than Aβ plaque accumulation; pathological tau alone is sufficient to elicit frontotemporal dementia, but it does not cause AD. A growing amount of evidence suggests that soluble Aβ oligomers in concert with hyperphosphorylated tau (pTau) serve as the major pathogenic drivers of neurodegeneration in AD. Increased Aβ oligomers trigger neuronal dysfunction and network alternations in learning and memory circuitry prior to clinical onset of AD, leading to cognitive decline. Furthermore, accumulated damage to mitochondria in the course of aging, which is the best-known nongenetic risk factor for AD, may collaborate with soluble Aβ and pTau to induce synapse loss and cognitive impairment in AD. In this review, I summarize and discuss the current knowledge of the molecular and cellular biology of AD and also the mechanisms that underlie Aβ-mediated neurodegeneration.
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Affiliation(s)
- Sangyun Jeong
- Department of Molecular Biology, Chonbuk National University, Jeonju 54896,
Korea
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241
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The Physiological and Pathological Implications of the Formation of Hydrogels, with a Specific Focus on Amyloid Polypeptides. Biomolecules 2017; 7:biom7040070. [PMID: 28937634 PMCID: PMC5745453 DOI: 10.3390/biom7040070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 08/30/2017] [Accepted: 09/18/2017] [Indexed: 02/07/2023] Open
Abstract
Hydrogels are water-swollen and viscoelastic three-dimensional cross-linked polymeric network originating from monomer polymerisation. Hydrogel-forming polypeptides are widely found in nature and, at a cellular and organismal level, they provide a wide range of functions for the organism making them. Amyloid structures, arising from polypeptide aggregation, can be damaging or beneficial to different types of organisms. Although the best-known amyloids are those associated with human pathologies, this underlying structure is commonly used by higher eukaryotes to maintain normal cellular activities, and also by microbial communities to promote their survival and growth. Amyloidogenesis occurs by nucleation-dependent polymerisation, which includes several species (monomers, nuclei, oligomers, and fibrils). Oligomers of pathological amyloids are considered the toxic species through cellular membrane perturbation, with the fibrils thought to represent a protective sink for toxic species. However, both functional and disease-associated amyloids use fibril cross-linking to form hydrogels. The properties of amyloid hydrogels can be exploited by organisms to fulfil specific physiological functions. Non-physiological hydrogelation by pathological amyloids may provide additional toxic mechanism(s), outside of membrane toxicity by oligomers, such as physical changes to the intracellular and extracellular environments, with wide-spread consequences for many structural and dynamic processes, and overall effects on cell survival.
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242
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Klein AN, Ziehm T, van Groen T, Kadish I, Elfgen A, Tusche M, Thomaier M, Reiss K, Brener O, Gremer L, Kutzsche J, Willbold D. Optimization of d-Peptides for Aβ Monomer Binding Specificity Enhances Their Potential to Eliminate Toxic Aβ Oligomers. ACS Chem Neurosci 2017; 8:1889-1900. [PMID: 28581708 DOI: 10.1021/acschemneuro.7b00045] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Amyloid-beta (Aβ) oligomers are thought to be causative for the development and progression of Alzheimer's disease (AD). Starting from the Aβ oligomer eliminating d-enantiomeric peptide D3, we developed and applied a two-step procedure based on peptide microarrays to identify D3 derivatives with increased binding affinity and specificity for monomeric Aβ(1-42) to further enhance the Aβ oligomer elimination efficacy. Out of more than 1000 D3 derivatives, we selected seven novel d-peptides, named ANK1 to ANK7, and characterized them in more detail in vitro. All ANK peptides bound to monomeric Aβ(1-42), eliminated Aβ(1-42) oligomers, inhibited Aβ(1-42) fibril formation, and reduced Aβ(1-42)-induced cytotoxicity more efficiently than D3. Additionally, ANK6 completely inhibited the prion-like propagation of preformed Aβ(1-42) seeds and showed a nonsignificant tendency for improving memory performance of tg-APPSwDI mice after i.p. application for 4 weeks. This supports the hypothesis that stabilization of Aβ monomers and thereby induced elimination of Aβ oligomers is a suitable therapeutic strategy.
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Affiliation(s)
- Antonia Nicole Klein
- Institute
of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425 Jülich, Germany
| | - Tamar Ziehm
- Institute
of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425 Jülich, Germany
| | - Thomas van Groen
- Department
of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Inga Kadish
- Department
of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Anne Elfgen
- Institute
of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425 Jülich, Germany
| | - Markus Tusche
- Institute
of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425 Jülich, Germany
| | - Maren Thomaier
- Institute
of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425 Jülich, Germany
| | - Kerstin Reiss
- Institute
of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425 Jülich, Germany
| | - Oleksandr Brener
- Institute
of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425 Jülich, Germany
- Institut
für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Lothar Gremer
- Institute
of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425 Jülich, Germany
- Institut
für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Janine Kutzsche
- Institute
of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425 Jülich, Germany
| | - Dieter Willbold
- Institute
of Complex Systems, Structural Biochemistry (ICS-6), Research Center Jülich, 52425 Jülich, Germany
- Institut
für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
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243
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TREM2 promotes Aβ phagocytosis by upregulating C/EBPα-dependent CD36 expression in microglia. Sci Rep 2017; 7:11118. [PMID: 28894284 PMCID: PMC5593901 DOI: 10.1038/s41598-017-11634-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 08/25/2017] [Indexed: 11/09/2022] Open
Abstract
TREM2 plays a critical role in the alleviation of Alzheimer's disease by promoting Aβ phagocytosis by microglia, but the detailed molecular mechanism underlying TREM2-induced direct phagocytic activity of Aβ remains to be revealed. We found that learning and memory functions were improved in aged TREM2 TG mice, with the opposite effects in KO mice. The amount of phagocytosed Aβ was significantly reduced in the primary microglia of KO mice. CD36 expression in primary microglia was greater in TG than in WT mice but was substantially decreased in KO mice. The expression of C/EBPα, an upstream transcriptional activator of CD36, was also elevated in primary microglia of TG mice but decreased in KO mice. The transcription of CD36 was markedly increased by TREM2 overexpression, and this effect was suppressed by a mutation of the C/EBPα binding site on the CD36 promoter. The TREM2-induced expression of CD36 and C/EBPα was inhibited by treatment with PI3K/AKT signaling blockers, and phosphorylation of AKT was elevated in TREM2-overexpressing BV2 cells. The present study provides evidence that TREM2 is required for preventing loss of memory and learning in Alzheimer's disease by regulating C/EBPα-dependent CD36 expression and the consequent Aβ phagocytosis.
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244
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Zeng Q, Man R, Luo Y, Zeng L, Zhong Y, Lu B, Wang X. IRF-8 is Involved in Amyloid-β 1-40 (Aβ 1-40)-induced Microglial Activation: a New Implication in Alzheimer's Disease. J Mol Neurosci 2017; 63:159-164. [PMID: 28856571 DOI: 10.1007/s12031-017-0966-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 08/16/2017] [Indexed: 12/29/2022]
Abstract
It is well known that extracellular deposition of amyloid-β (Aβ) peptide and microglia-mediated neuroinflammation are major hallmarks of Alzheimer's disease (AD). Interferon regulatory factor-8 (IRF-8), an important transcription factor of the IRF family, is highly restricted in microglia in brains. The expression pattern and function of IRF-8 in AD need to be elucidated in order to provide novel therapies for the treatment of AD. In this study, our results indicated that expression of IRF-8 is significantly elevated in the brains and microglia of AD transgenic model Tg2576 mice. Notably, in vitro cell culture and reporter luciferase assay show that Aβ1-40 treatment promotes expression of IRF-8 at the transcriptional level. Silencing of IRF-8 in microglia abolished Aβ1-40-induced elevation in typical activated microglia-related genes, including the microglial innate response receptor toll-like receptor 2 (TLR2), the chemotaxis gene purinergic receptor P2Y12R, and the proinflammatory cytokine IL-1β. However, overexpression of IRF-8 exacerbated the elevated expression of these proteins. Finally, the JAK2/STAT-1 pathway was found to mediate Aβ1-40-induced elevation of IRF-8. Overall, this is the first time to report that IRF-8 is involved in microglial activation and neuroinflammation in AD.
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Affiliation(s)
- Qinggan Zeng
- Department of Neurology, The Third Affiliated Hospital of Southern Medical University, No. 183, Zhongshan Road West, Guangzhou, Guangdong, 510630, China
| | - Rongyong Man
- Department of Neurology, The First People's Hospital of Huaihua, Affiliated to University of South China, No. 144, Jinxi Road South, Huaihua, 418000, China
| | - Yifeng Luo
- Department of Neurology, The Third Affiliated Hospital of Southern Medical University, No. 183, Zhongshan Road West, Guangzhou, Guangdong, 510630, China
| | - Ling Zeng
- Department of Neurology, The First People's Hospital of Huaihua, Affiliated to University of South China, No. 144, Jinxi Road South, Huaihua, 418000, China
| | - Yushi Zhong
- Department of Neurology, The First People's Hospital of Huaihua, Affiliated to University of South China, No. 144, Jinxi Road South, Huaihua, 418000, China
| | - Bingxun Lu
- Department of Neurology, The Third Affiliated Hospital of Southern Medical University, No. 183, Zhongshan Road West, Guangzhou, Guangdong, 510630, China
| | - Xiaofeng Wang
- Department of Neurology, The Third Affiliated Hospital of Southern Medical University, No. 183, Zhongshan Road West, Guangzhou, Guangdong, 510630, China.
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245
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Diversity of Amyloid-beta Proteoforms in the Alzheimer's Disease Brain. Sci Rep 2017; 7:9520. [PMID: 28842697 PMCID: PMC5572664 DOI: 10.1038/s41598-017-10422-x] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/08/2017] [Indexed: 12/31/2022] Open
Abstract
Amyloid-beta (Aβ) plays a key role in the pathogenesis of Alzheimer’s disease (AD), but little is known about the proteoforms present in AD brain. We used high-resolution mass spectrometry to analyze intact Aβ from soluble aggregates and insoluble material in brains of six cases with severe dementia and pathologically confirmed AD. The soluble aggregates are especially relevant because they are believed to be the most toxic form of Aβ. We found a diversity of Aβ peptides, with 26 unique proteoforms including various N- and C-terminal truncations. N- and C-terminal truncations comprised 73% and 30%, respectively, of the total Aβ proteoforms detected. The Aβ proteoforms segregated between the soluble and more insoluble aggregates with N-terminal truncations predominating in the insoluble material and C- terminal truncations segregating into the soluble aggregates. In contrast, canonical Aβ comprised the minority of the identified proteoforms (15.3%) and did not distinguish between the soluble and more insoluble aggregates. The relative abundance of many truncated Aβ proteoforms did not correlate with post-mortem interval, suggesting they are not artefacts. This heterogeneity of Aβ proteoforms deepens our understanding of AD and offers many new avenues for investigation into pathological mechanisms of the disease, with implications for therapeutic development.
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246
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Study of Alzheimer's Disease-Related Biophysical Kinetics with a Microslit-Embedded Cantilever Sensor in a Liquid Environment. SENSORS 2017; 17:s17081819. [PMID: 28783132 PMCID: PMC5579575 DOI: 10.3390/s17081819] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 08/03/2017] [Accepted: 08/05/2017] [Indexed: 11/17/2022]
Abstract
A microsized slit-embedded cantilever sensor (slit cantilever) was fabricated and evaluated as a biosensing platform in a liquid environment. In order to minimize the degradation caused by viscous damping, a 300 × 100 µm2 (length × width) sized cantilever was released by a 5 µm gap-surrounding and vibrated by an internal piezoelectric-driven self-actuator. Owing to the structure, when the single side of the slit cantilever was exposed to liquid a significant quality factor (Q = 35) could be achieved. To assess the sensing performance, the slit cantilever was exploited to study the biophysical kinetics related to Aβ peptide. First, the quantification of Aβ peptide with a concentration of 10 pg/mL to 1 μg/mL was performed. The resonant responses exhibited a dynamic range from 100 pg/mL to 100 ng/mL (−56.5 to −774 ΔHz) and a dissociation constant (KD) of binding affinity was calculated as 1.75 nM. Finally, the Aβ self-aggregation associated with AD pathogenesis was monitored by adding monomeric Aβ peptides. As the concentration of added analyte increased from 100 ng/mL to 10 µg/mL, both the frequency shift values (−813 to −1804 ΔHz) and associate time constant increased. These results showed the excellent sensing performance of the slit cantilever overcoming a major drawback in liquid environments to become a promising diagnostic tool candidate.
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247
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Palavicini JP, Wang C, Chen L, Hosang K, Wang J, Tomiyama T, Mori H, Han X. Oligomeric amyloid-beta induces MAPK-mediated activation of brain cytosolic and calcium-independent phospholipase A 2 in a spatial-specific manner. Acta Neuropathol Commun 2017; 5:56. [PMID: 28750656 PMCID: PMC5530945 DOI: 10.1186/s40478-017-0460-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 07/19/2017] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease (AD) is histopathologically characterized by the build-up of fibrillar amyloid beta (Aβ) in the form of amyloid plaques and the development of intraneuronal neurofibrillary tangles consisting of aggregated hyperphosphorylated Tau. Although amyloid fibrils were originally considered responsible for AD pathogenesis, recent convincing evidence strongly implicates soluble oligomeric Aβ as the primary neurotoxic species driving disease progression. A third largely ignored pathological hallmark, originally described by Alois Alzheimer, is the presence of "adipose inclusions", suggestive of aberrant lipid metabolism. The molecular mechanisms underlying these "lipoid granules", as well as their potential link to soluble and/or fibrillar Aβ remain largely unknown. Seeking to better-understand these conundrums, we took advantage of the powerful technology of multidimensional mass spectrometry-based shotgun lipidomics and an AD transgenic mouse model overexpressing mutant amyloid precursor protein (APP E693Δ-Osaka-), where AD-like pathology and neurodegeneration occur as a consequence of oligomeric Aβ accumulation in the absence of amyloid plaques. Our results revealed for the first time that APP overexpression and oligomeric Aβ accumulation lead to an additive global accumulation of nonesterified polyunsaturated fatty acids (PUFAs) independently of amyloid plaques. Furthermore, we revealed that this accumulation is mediated by an increase in phospholipase A2 (PLA2) activity, evidenced by an accumulation of sn-1 lysophosphatidylcholine and by MAPK-mediated phosphorylation/activation of group IV Ca2+-dependent cytosolic (cPLA2) and the group VI Ca2+-independent PLA2 (iPLA2) independently of PKC. We further revealed that Aβ-induced oxidative stress also disrupts lipid metabolism via reactive oxygen species-mediated phospholipid cleavage leading to increased sn-2 lysophosphatidylcholine as well as lipid peroxidation and the subsequent accumulation of 4-hydroxynonenal. Brain histological studies implicated cPLA2 activity with arachidonic acid accumulation within myelin-rich regions, and iPLA2 activity with docosahexaenoic acid accumulation within pyramidal neuron-rich regions. Taken together, our results suggest that PLA2-mediated accumulation of free PUFAs drives AD-related disruption of brain lipid metabolism.
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248
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Dorosh L, Stepanova M. Probing oligomerization of amyloid beta peptide in silico. MOLECULAR BIOSYSTEMS 2017; 13:165-182. [PMID: 27844078 DOI: 10.1039/c6mb00441e] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Aggregation of amyloid β (Aβ) peptide is implicated in fatal Alzheimer's disease, for which no cure is available. Understanding the mechanisms responsible for this aggregation is required in order for therapies to be developed. In an effort to better understand the molecular mechanisms involved in spontaneous aggregation of Aβ peptide, extensive molecular dynamics simulations are reported, and the results are analyzed through a combination of structural biology tools and a novel essential collective dynamics method. Several model systems composed of ten or twelve Aβ17-42 chains in water are investigated, and the influence of metal ions is probed. The results suggest that Aβ monomers tend to aggregate into stable globular-like oligomers with 13-23% of β-sheet content. Two stages of oligomer formation have been identified: quick collapse within the first 40 ns of the simulation, characterized by a decrease in inter-chain separation and build-up of β-sheets, and the subsequent slow relaxation of the oligomer structure. The resulting oligomers comprise a stable, coherently moving sub-aggregate of 6-9 strongly inter-correlated chains. Cu2+ and Fe2+ ions have been found to develop coordination bonds with carboxylate groups of E22, D23 and A42, which remain stable during 200 ns simulations. The presence of Fe2+, and particularly Cu2+ ions, in negatively charged cavities has been found to cause significant changes in the structure and dynamics of the oligomers. The results indicate, in particular, that formation of non-fibrillar oligomers might be involved in early template-free aggregation of Aβ17-42 monomers, with charged species such as Cu2+ or Fe2+ ions playing an important role.
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Affiliation(s)
- L Dorosh
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada. and National Research Council of Canada, Edmonton, Alberta, Canada
| | - M Stepanova
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada. and National Research Council of Canada, Edmonton, Alberta, Canada and Department of Physics, Astronomy, and Materials Science, Missouri State University, Springfield, MO, USA
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249
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Yin K, Jin J, Zhu X, Yu L, Wang S, Qian L, Han L, Xu Y. CART modulates beta-amyloid metabolism-associated enzymes and attenuates memory deficits in APP/PS1 mice. Neurol Res 2017; 39:885-894. [PMID: 28743230 DOI: 10.1080/01616412.2017.1348689] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Kailin Yin
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Jiali Jin
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Xiaolei Zhu
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Linjie Yu
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Sulei Wang
- Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Lai Qian
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Lijuan Han
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Yun Xu
- Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
- Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, China
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250
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Colin J, Allouche A, Chauveau F, Corbier C, Pauron-Gregory L, Lanhers MC, Claudepierre T, Yen FT, Oster T, Malaplate-Armand C. Improved Neuroprotection Provided by Drug Combination in Neurons Exposed to Cell-Derived Soluble Amyloid-β Peptide. J Alzheimers Dis 2017; 52:975-87. [PMID: 27163806 DOI: 10.3233/jad-151110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Oligomeric amyloid-β (Aβ) peptide contributes to impaired synaptic connections and neurodegenerative processes, and as such, represents a primary therapeutic target for Alzheimer's disease (AD)-modifying approaches. However, the lack of efficacy of drugs that inhibit production of Aβ demonstrates the need for a better characterization of its toxic effects, both on synaptic and neuronal function. Here, we used conditioned medium obtained from recombinant HEK-AβPP cells expressing the human amyloid-β protein precursor (Aβ-CM), to investigate Aβ-induced neurotoxic and synaptotoxic effects. Characterization of Aβ-CM revealed that it contained picomolar amounts of cell-secreted Aβ in its soluble form. Incubation of primary cortical neurons with Aβ-CM led to significant decreases in synaptic protein levels as compared to controls. This effect was no longer observed in neurons incubated with conditioned medium obtained from HEK-AβPP cells grown in presence of the γ-secretase inhibitor, Semagacestat or LY450139 (LY-CM). However, neurotoxic and pro-apoptotic effects of Aβ-CM were only partially prevented using LY-CM, which could be explained by other deleterious compounds related to chronic oxidative stress that were released by HEK-AβPP cells. Indeed, full neuroprotection was observed in cells exposed to LY-CM by additional treatment with the antioxidant resveratrol, or with the pluripotent n-3 polyunsaturated fatty acid docosahexaenoic acid. Inhibition of Aβ production appeared necessary but insufficient to prevent neurodegenerative effects associated with AD due to other neurotoxic compounds that could exert additional deleterious effects on neuronal function and survival. Therefore, association of various types of protective agents needs to be considered when developing strategies for AD treatment.
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Affiliation(s)
- Julie Colin
- Université de Lorraine, ENSAIA, UR AFPA, EA 3998, USC INRA 0340, Nancy, France
| | - Ahmad Allouche
- Université de Lorraine, ENSAIA, UR AFPA, EA 3998, USC INRA 0340, Nancy, France
| | - Fabien Chauveau
- Université de Lyon 1, Lyon Neuroscience Research Center; CNRS UMR5292; INSERM U1028; Lyon, France
| | - Catherine Corbier
- Université de Lorraine, ENSAIA, UR AFPA, EA 3998, USC INRA 0340, Nancy, France
| | - Lynn Pauron-Gregory
- Université de Lorraine, ENSAIA, UR AFPA, EA 3998, USC INRA 0340, Nancy, France
| | | | - Thomas Claudepierre
- Université de Lorraine, ENSAIA, UR AFPA, EA 3998, USC INRA 0340, Nancy, France
| | - Frances T Yen
- Université de Lorraine, ENSAIA, UR AFPA, EA 3998, USC INRA 0340, Nancy, France
| | - Thierry Oster
- Université de Lorraine, ENSAIA, UR AFPA, EA 3998, USC INRA 0340, Nancy, France
| | - Catherine Malaplate-Armand
- Université de Lorraine, ENSAIA, UR AFPA, EA 3998, USC INRA 0340, Nancy, France.,Laboratoire de Biochimie, Hôpital Central, CHU de Nancy, CO n°34, Nancy, France
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