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Pahal S, Gupta A, Choudhary P, Chaudhary A, Singh S. Network pharmacological evaluation of Withania somnifera bioactive phytochemicals for identifying novel potential inhibitors against neurodegenerative disorder. J Biomol Struct Dyn 2022; 40:10887-10898. [PMID: 34278961 DOI: 10.1080/07391102.2021.1951355] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neurodegenerative disorders are illnesses that are responsible for neuronal cell death and resulting in lifelong cognitive problems. Due to their unclear mechanism, there are no effective drugs available for the treatment. For a long time, herbal drugs have been used as a role model in the field of the drug discovery process. Withania somnifera (Ashwagandha) in the Indian medicinal system (Ayurveda) is used for several neuronal disorders like insomnia and memory loss for decades. This study aims to identify active components of W. somnifera (WS) as potential inhibitors for the treatment of neurodegenerative diseases (ND). To fulfill this objective, Network pharmacology approach, gene ontology, pharmacokinetics analysis, molecular docking, and molecular dynamics simulation (MDS) studies were performed. A total of 77 active components in WS, 175 predicted neurodegenerative targets of WS, and 8085 ND-related targets were identified from different databases. The network analysis showed that the top ten targets APP, EGFR, MAPK1, ESR1, HSPA4, PRKCD, MAPK3, ABL1, JUN, and GSK3B were found as significant target related to ND. On the basis of gene ontology and topology analysis results, APP was found as a significant target related to Alzheimer's disease pathways. Molecular docking results found that Anahygrine, Cuscohygrine, Isopelletierine, and Nicotine showed the best binding affinities -5.55, -4.73, -4.04, and -4.11 Kcal/mol. Further, MDS results suggested that Isopelletierine and Nicotine could be used as potential inhibitors against APP protein and could be useful for the treatment of Alzheimer's disease.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sonu Pahal
- Department of Applied Sciences, Indian Institute of Information Technology Allahabad, Prayagraj, India
| | - Ayushi Gupta
- Department of Applied Sciences, Indian Institute of Information Technology Allahabad, Prayagraj, India
| | - Princy Choudhary
- Department of Applied Sciences, Indian Institute of Information Technology Allahabad, Prayagraj, India
| | - Amit Chaudhary
- Amity Institute of Biotechnology, Amity University, Noida, India
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2
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Delport A, Hewer R. The amyloid precursor protein: a converging point in Alzheimer's disease. Mol Neurobiol 2022; 59:4501-4516. [PMID: 35579846 DOI: 10.1007/s12035-022-02863-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 04/30/2022] [Indexed: 11/30/2022]
Abstract
The decades of evidence that showcase the role of amyloid precursor protein (APP), and its fragment amyloidβ (Aβ), in Alzheimer's disease (AD) pathogenesis are irrefutable. However, the absolute focus on the single APP metabolite Aβ as the cause for AD has resulted in APP and its other fragments that possess toxic propensity, to be overlooked as targets for treatment. The complexity of its processing and its association with systematic metabolism suggests that, if misregulated, APP has the potential to provoke an array of metabolic dysfunctions. This review discusses APP and several of its cleaved products with a particular focus on their toxicity and ability to disrupt healthy cellular function, in relation to AD development. We subsequently argue that the reduction of APP, which would result in a concurrent decrease in Aβ as well as all other toxic APP metabolites, would alleviate the toxic environment associated with AD and slow disease progression. A discussion of those drug-like compounds already identified to possess this capacity is also included.
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Affiliation(s)
- Alexandré Delport
- Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, 3201, South Africa.
| | - Raymond Hewer
- Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, 3201, South Africa
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Diaz JR, Martá-Ariza M, Khodadadi-Jamayran A, Heguy A, Tsirigos A, Pankiewicz JE, Sullivan PM, Sadowski MJ. Apolipoprotein E4 Effects a Distinct Transcriptomic Profile and Dendritic Arbor Characteristics in Hippocampal Neurons Cultured in vitro. Front Aging Neurosci 2022; 14:845291. [PMID: 35572125 PMCID: PMC9099260 DOI: 10.3389/fnagi.2022.845291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
The APOE gene is diversified by three alleles ε2, ε3, and ε4 encoding corresponding apolipoprotein (apo) E isoforms. Possession of the ε4 allele is signified by increased risks of age-related cognitive decline, Alzheimer's disease (AD), and the rate of AD dementia progression. ApoE is secreted by astrocytes as high-density lipoprotein-like particles and these are internalized by neurons upon binding to neuron-expressed apoE receptors. ApoE isoforms differentially engage neuronal plasticity through poorly understood mechanisms. We examined here the effects of native apoE lipoproteins produced by immortalized astrocytes homozygous for ε2, ε3, and ε4 alleles on the maturation and the transcriptomic profile of primary hippocampal neurons. Control neurons were grown in the presence of conditioned media from Apoe -/- astrocytes. ApoE2 and apoE3 significantly increase the dendritic arbor branching, the combined neurite length, and the total arbor surface of the hippocampal neurons, while apoE4 fails to produce similar effects and even significantly reduces the combined neurite length compared to the control. ApoE lipoproteins show no systemic effect on dendritic spine density, yet apoE2 and apoE3 increase the mature spines fraction, while apoE4 increases the immature spine fraction. This is associated with opposing effects of apoE2 or apoE3 and apoE4 on the expression of NR1 NMDA receptor subunit and PSD95. There are 1,062 genes differentially expressed across neurons cultured in the presence of apoE lipoproteins compared to the control. KEGG enrichment and gene ontology analyses show apoE2 and apoE3 commonly activate expression of genes involved in neurite branching, and synaptic signaling. In contrast, apoE4 cultured neurons show upregulation of genes related to the glycolipid metabolism, which are involved in dendritic spine turnover, and those which are usually silent in neurons and are related to cell cycle and DNA repair. In conclusion, our work reveals that lipoprotein particles comprised of various apoE isoforms differentially regulate various neuronal arbor characteristics through interaction with neuronal transcriptome. ApoE4 produces a functionally distinct transcriptomic profile, which is associated with attenuated neuronal development. Differential regulation of neuronal transcriptome by apoE isoforms is a newly identified biological mechanism, which has both implication in the development and aging of the CNS.
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Affiliation(s)
- Jenny R. Diaz
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Mitchell Martá-Ariza
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | | | - Adriana Heguy
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, United States
| | - Aristotelis Tsirigos
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, United States
| | - Joanna E. Pankiewicz
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Biochemistry and Pharmacology, New York University Grossman School of Medicine, New York, NY, United States
| | - Patrick M. Sullivan
- Department of Medicine (Geriatrics), Duke University School of Medicine, Durham, NC, United States
- Durham VA Medical Center’s, Geriatric Research Education and Clinical Center, Durham, NC, United States
| | - Martin J. Sadowski
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Biochemistry and Pharmacology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
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4
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Wu CH, Tsai HP, Su YF, Tsai CY, Lu YY, Lin CL. 2-PMAP Ameliorates Cerebral Vasospasm and Brain Injury after Subarachnoid Hemorrhage by Regulating Neuro-Inflammation in Rats. Cells 2022; 11:242. [PMID: 35053358 PMCID: PMC8773560 DOI: 10.3390/cells11020242] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/27/2021] [Accepted: 01/07/2022] [Indexed: 02/01/2023] Open
Abstract
A subarachnoid hemorrhage (SAH), leading to severe disability and high fatality in survivors, is a devastating disease. Neuro-inflammation, a critical mechanism of cerebral vasospasm and brain injury from SAH, is tightly related to prognoses. Interestingly, studies indicate that 2-[(pyridine-2-ylmethyl)-amino]-phenol (2-PMAP) crosses the blood-brain barrier easily. Here, we investigated whether the vasodilatory and neuroprotective roles of 2-PMAP were observed in SAH rats. Rats were assigned to three groups: sham, SAH and SAH+2-PMAP. SAHs were induced by a cisterna magna injection. In the SAH+2-PMAP group, 5 mg/kg 2-PMAP was injected into the subarachnoid space before SAH induction. The administration of 2-PMAP markedly ameliorated cerebral vasospasm and decreased endothelial apoptosis 48 h after SAH. Meanwhile, 2-PMAP decreased the severity of neurological impairments and neuronal apoptosis after SAH. Furthermore, 2-PMAP decreased the activation of microglia and astrocytes, expressions of TLR-4 and p-NF-κB, inflammatory markers (TNF-α, IL-1β and IL-6) and reactive oxygen species. This study is the first to confirm that 2-PMAP has vasodilatory and neuroprotective effects in a rat model of SAH. Taken together, the experimental results indicate that 2-PMAP treatment attenuates neuro-inflammation, oxidative stress and cerebral vasospasm, in addition to ameliorating neurological deficits, and that these attenuating and ameliorating effects are conferred through the TLR-4/NF-κB pathway.
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Affiliation(s)
- Chieh-Hsin Wu
- Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (C.-H.W.); (H.-P.T.); (Y.-F.S.); (C.-Y.T.)
- Department of Surgery, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80756, Taiwan
| | - Hung-Pei Tsai
- Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (C.-H.W.); (H.-P.T.); (Y.-F.S.); (C.-Y.T.)
| | - Yu-Feng Su
- Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (C.-H.W.); (H.-P.T.); (Y.-F.S.); (C.-Y.T.)
- Department of Surgery, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80756, Taiwan
| | - Cheng-Yu Tsai
- Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (C.-H.W.); (H.-P.T.); (Y.-F.S.); (C.-Y.T.)
- Department of Surgery, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80756, Taiwan
| | - Ying-Yi Lu
- Department of Dermatology, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan
- Department of Health and Beauty, Shu-Zen Junior College of Medicine and Management, Kaohsiung 821, Taiwan
| | - Chih-Lung Lin
- Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan; (C.-H.W.); (H.-P.T.); (Y.-F.S.); (C.-Y.T.)
- Department of Surgery, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80756, Taiwan
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Chan EWL, Yeo ETY, Wong KWL, See ML, Wong KY, Yap JKY, Gan SY. Piper sarmentosum Roxb. Attenuates Beta Amyloid (Aβ)-Induced Neurotoxicity Via the Inhibition of Amyloidogenesis and Tau Hyperphosphorylation in SH-SY5Y Cells. Curr Alzheimer Res 2021; 18:80-87. [PMID: 33761853 DOI: 10.2174/1567205018666210324124239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 01/29/2021] [Accepted: 03/15/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND In Alzheimer's disease, accumulation of beta amyloid (Aβ) triggers amyloidogenesis and hyperphosphorylation of tau protein leading to neuronal cell death. Piper sarmentosum Roxb. (PS) is a traditional medicinal herb used by Malay to treat rheumatism, headache and boost memory. It possesses various biological effects, such as anti-cholinergic, anti-inflammatory, anti-oxidant and anti-depressant-like effects. OBJECTIVE The present study aimed to investigate neuroprotective properties of PS against Aβ-induced neurotoxicity and to evaluate its potential mechanism of action. METHODS Neuroprotective effects of hexane (HXN), dichloromethane (DCM), ethyl acetate (EA) and methanol (MEOH) extracts from leaves (L) and roots (R) of PS against Aβ-induced neurotoxicity were investigated in SH-SY5Y human neuroblastoma cells. Cells were pre-treated with PS for 24 h followed by 24 h of induction with Aβ. The neuroprotective effects of PS were studied using cell viability and cellular reactive oxygen species (ROS) assays. The levels of extracellular Aβ and tau proteins phosphorylated at threonine 231 (pT231) were determined. Gene and protein expressions were assessed using qRT-PCR analyses and western blot analyses, respectively. RESULTS Hexane extracts of PS (LHXN and RHXN) protected SH-SY5Y cells against Aβ-induced neurotoxicity, and decreased levels of extracellular Aβ and phosphorylated tau (pT231). Although extracts of PS inhibited Aβ-induced ROS production, it was unlikely that neuroprotective effects were simply due to the anti-oxidant capacity of PS. Further, mechanistic study suggested that the neuroprotective effects of PS might be due to its capability to regulate amyloidogenesis through the downregulation of BACE and APP. CONCLUSION These findings suggest that hexane extracts of PS confer neuroprotection against Aβ- induced neurotoxicity in SH-SY5Y cells by attenuating amyloidogenesis and tau hyperphosphorylation. Due to its neuroprotective properties, PS might be a potential therapeutic agent for Alzheimer's disease.
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Affiliation(s)
- Elaine W L Chan
- Institute for Research, Development and Innovation, International Medical University, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur,Malaysia
| | - Emilia T Y Yeo
- School of Pharmacy, International Medical University, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur,Malaysia
| | - Kelly W L Wong
- School of Pharmacy, International Medical University, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur,Malaysia
| | - Mun L See
- School of Pharmacy, International Medical University, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur,Malaysia
| | - Ka Y Wong
- School of Pharmacy, International Medical University, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur,Malaysia
| | - Jeremy K Y Yap
- School of Postgraduate Studies, International Medical University, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur,Malaysia
| | - Sook Y Gan
- School of Pharmacy, International Medical University, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur,Malaysia
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6
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Pankiewicz JE, Diaz JR, Martá-Ariza M, Lizińczyk AM, Franco LA, Sadowski MJ. Peroxiredoxin 6 mediates protective function of astrocytes in Aβ proteostasis. Mol Neurodegener 2020; 15:50. [PMID: 32907613 PMCID: PMC7487614 DOI: 10.1186/s13024-020-00401-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 08/24/2020] [Indexed: 11/10/2022] Open
Abstract
Background Disruption of β-amyloid (Aβ) homeostasis is the initial culprit in Alzheimer’s disease (AD) pathogenesis. Astrocytes respond to emerging Aβ plaques by altering their phenotype and function, yet molecular mechanisms governing astrocytic response and their precise role in countering Aβ deposition remain ill-defined. Peroxiredoxin (PRDX) 6 is an enzymatic protein with independent glutathione peroxidase (Gpx) and phospholipase A2 (PLA2) activities involved in repair of oxidatively damaged cell membrane lipids and cellular signaling. In the CNS, PRDX6 is uniquely expressed by astrocytes and its exact function remains unexplored. Methods APPswe/PS1dE9 AD transgenic mice were once crossed to mice overexpressing wild-type Prdx6 allele or to Prdx6 knock out mice. Aβ pathology and associated neuritic degeneration were assessed in mice aged 10 months. Laser scanning confocal microscopy was used to characterize Aβ plaque morphology and activation of plaque-associated astrocytes and microglia. Effect of Prdx6 gene dose on plaque seeding was assessed in mice aged six months. Results We show that hemizygous knock in of the overexpressing Prdx6 transgene in APPswe/PS1dE9 AD transgenic mice promotes selective enticement of astrocytes to Aβ plaques and penetration of plaques by astrocytic processes along with increased number and phagocytic activation of periplaque microglia. This effects suppression of nascent plaque seeding and remodeling of mature plaques consequently curtailing brain Aβ load and Aβ-associated neuritic degeneration. Conversely, Prdx6 haplodeficiency attenuates astro- and microglia activation around Aβ plaques promoting Aβ deposition and neuritic degeneration. Conclusions We identify here PRDX6 as an important factor regulating response of astrocytes toward Aβ plaques. Demonstration that phagocytic activation of periplaque microglia vary directly with astrocytic PRDX6 expression level implies previously unappreciated astrocyte-guided microglia effect in Aβ proteostasis. Our showing that upregulation of PRDX6 attenuates Aβ pathology may be of therapeutic relevance for AD.
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Affiliation(s)
- Joanna E Pankiewicz
- Department of Neurology, New York University Grossman School of Medicine, 550 First Avenue, Science Building, Room 10-07, New York, NY, 10016, USA.,Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Jenny R Diaz
- Department of Neurology, New York University Grossman School of Medicine, 550 First Avenue, Science Building, Room 10-07, New York, NY, 10016, USA
| | - Mitchell Martá-Ariza
- Department of Neurology, New York University Grossman School of Medicine, 550 First Avenue, Science Building, Room 10-07, New York, NY, 10016, USA
| | - Anita M Lizińczyk
- Department of Neurology, New York University Grossman School of Medicine, 550 First Avenue, Science Building, Room 10-07, New York, NY, 10016, USA
| | - Leor A Franco
- Department of Neurology, New York University Grossman School of Medicine, 550 First Avenue, Science Building, Room 10-07, New York, NY, 10016, USA
| | - Martin J Sadowski
- Department of Neurology, New York University Grossman School of Medicine, 550 First Avenue, Science Building, Room 10-07, New York, NY, 10016, USA. .,Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, 10016, USA. .,Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, 10016, USA.
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7
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Corsetti V, Borreca A, Latina V, Giacovazzo G, Pignataro A, Krashia P, Natale F, Cocco S, Rinaudo M, Malerba F, Florio R, Ciarapica R, Coccurello R, D’Amelio M, Ammassari-Teule M, Grassi C, Calissano P, Amadoro G. Passive immunotherapy for N-truncated tau ameliorates the cognitive deficits in two mouse Alzheimer's disease models. Brain Commun 2020; 2:fcaa039. [PMID: 32954296 PMCID: PMC7425324 DOI: 10.1093/braincomms/fcaa039] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/05/2020] [Accepted: 02/12/2020] [Indexed: 12/12/2022] Open
Abstract
Clinical and neuropathological studies have shown that tau pathology better correlates with the severity of dementia than amyloid plaque burden, making tau an attractive target for the cure of Alzheimer's disease. We have explored whether passive immunization with the 12A12 monoclonal antibody (26-36aa of tau protein) could improve the Alzheimer's disease phenotype of two well-established mouse models, Tg2576 and 3xTg mice. 12A12 is a cleavage-specific monoclonal antibody which selectively binds the pathologically relevant neurotoxic NH226-230 fragment (i.e. NH2htau) of tau protein without cross-reacting with its full-length physiological form(s). We found out that intravenous administration of 12A12 monoclonal antibody into symptomatic (6 months old) animals: (i) reaches the hippocampus in its biologically active (antigen-binding competent) form and successfully neutralizes its target; (ii) reduces both pathological tau and amyloid precursor protein/amyloidβ metabolisms involved in early disease-associated synaptic deterioration; (iii) improves episodic-like type of learning/memory skills in hippocampal-based novel object recognition and object place recognition behavioural tasks; (iv) restores the specific up-regulation of the activity-regulated cytoskeleton-associated protein involved in consolidation of experience-dependent synaptic plasticity; (v) relieves the loss of dendritic spine connectivity in pyramidal hippocampal CA1 neurons; (vi) rescues the Alzheimer's disease-related electrophysiological deficits in hippocampal long-term potentiation at the CA3-CA1 synapses; and (vii) mitigates the neuroinflammatory response (reactive gliosis). These findings indicate that the 20-22 kDa NH2-terminal tau fragment is crucial target for Alzheimer's disease therapy and prospect immunotherapy with 12A12 monoclonal antibody as safe (normal tau-preserving), beneficial approach in contrasting the early Amyloidβ-dependent and independent neuropathological and cognitive alterations in affected subjects.
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Affiliation(s)
| | - Antonella Borreca
- Humanitas University Laboratory of Pharmacology and Brain Pathology, Neuro Center, 20089 Milan, Italy
- Institute of Neuroscience, 20129 Milan, Italy
| | | | | | | | - Paraskevi Krashia
- IRCSS Santa Lucia Foundation, 00143 Rome, Italy
- Department of Medicine, University Campus Bio-Medico, 00128 Rome, Italy
- Department of Science and Technology for Humans and Environment, University Campus Bio-medico, 00128 Rome, Italy
| | - Francesca Natale
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Sara Cocco
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Marco Rinaudo
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | | | - Rita Florio
- European Brain Research Institute (EBRI), 00161 Rome, Italy
| | | | - Roberto Coccurello
- IRCSS Santa Lucia Foundation, 00143 Rome, Italy
- Institute for Complex Systems (ISC), CNR, 00185 Rome, Italy
| | - Marcello D’Amelio
- IRCSS Santa Lucia Foundation, 00143 Rome, Italy
- Department of Medicine, University Campus Bio-Medico, 00128 Rome, Italy
- Department of Science and Technology for Humans and Environment, University Campus Bio-medico, 00128 Rome, Italy
| | | | - Claudio Grassi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | | | - Giuseppina Amadoro
- European Brain Research Institute (EBRI), 00161 Rome, Italy
- Institute of Translational Pharmacology (IFT)–National Research Council (CNR), 00133 Rome, Italy
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8
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Alasmari F, Alshammari MA, Alasmari AF, Alanazi WA, Alhazzani K. Neuroinflammatory Cytokines Induce Amyloid Beta Neurotoxicity through Modulating Amyloid Precursor Protein Levels/Metabolism. BIOMED RESEARCH INTERNATIONAL 2018; 2018:3087475. [PMID: 30498753 PMCID: PMC6222241 DOI: 10.1155/2018/3087475] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/19/2018] [Accepted: 10/11/2018] [Indexed: 01/06/2023]
Abstract
Neuroinflammation has been observed in association with neurodegenerative diseases including Alzheimer's disease (AD). In particular, a positive correlation has been documented between neuroinflammatory cytokine release and the progression of the AD, which suggests these cytokines are involved in AD pathophysiology. A histological hallmark of the AD is the presence of beta-amyloid (Aβ) plaques and tau neurofibrillary tangles. Beta-amyloid is generated by the sequential cleavage of beta (β) and gamma (γ) sites in the amyloid precursor protein (APP) by β- and γ-secretase enzymes and its accumulation can result from either a decreased Aβ clearance or increased metabolism of APP. Previous studies reported that neuroinflammatory cytokines reduce the efflux transport of Aβ, leading to elevated Aβ concentrations in the brain. However, less is known about the effects of neuroinflammatory mediators on APP expression and metabolism. In this article, we review the modulatory role of neuroinflammatory cytokines on APP expression and metabolism, including their effects on β- and γ-secretase enzymes.
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Affiliation(s)
- Fawaz Alasmari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Musaad A. Alshammari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Abdullah F. Alasmari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Wael A. Alanazi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Khalid Alhazzani
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
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9
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Pankiewicz JE, Sanchez S, Kirshenbaum K, Kascsak RB, Kascsak RJ, Sadowski MJ. Anti-prion Protein Antibody 6D11 Restores Cellular Proteostasis of Prion Protein Through Disrupting Recycling Propagation of PrP Sc and Targeting PrP Sc for Lysosomal Degradation. Mol Neurobiol 2018; 56:2073-2091. [PMID: 29987703 DOI: 10.1007/s12035-018-1208-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 06/26/2018] [Indexed: 10/28/2022]
Abstract
PrPSc is an infectious and disease-specific conformer of the prion protein, which accumulation in the CNS underlies the pathology of prion diseases. PrPSc replicates by binding to the cellular conformer of the prion protein (PrPC) expressed by host cells and rendering its secondary structure a likeness of itself. PrPC is a plasma membrane anchored protein, which constitutively recirculates between the cell surface and the endocytic compartment. Since PrPSc engages PrPC along this trafficking pathway, its replication process is often referred to as "recycling propagation." Certain monoclonal antibodies (mAbs) directed against prion protein can abrogate the presence of PrPSc from prion-infected cells. However, the precise mechanism(s) underlying their therapeutic propensities remains obscure. Using N2A murine neuroblastoma cell line stably infected with 22L mouse-adapted scrapie strain (N2A/22L), we investigated here the modus operandi of the 6D11 clone, which was raised against the PrPSc conformer and has been shown to permanently clear prion-infected cells from PrPSc presence. We determined that 6D11 mAb engages and sequesters PrPC and PrPSc at the cell surface. PrPC/6D11 and PrPSc/6D11 complexes are then endocytosed from the plasma membrane and are directed to lysosomes, therefore precluding recirculation of nascent PrPSc back to the cell surface. Targeting PrPSc by 6D11 mAb to the lysosomal compartment facilitates its proteolysis and eventually shifts the balance between PrPSc formation and degradation. Ongoing translation of PrPC allows maintaining the steady-state level of prion protein within the cells, which was not depleted under 6D11 mAb treatment. Our findings demonstrate that through disrupting recycling propagation of PrPSc and promoting its degradation, 6D11 mAb restores cellular proteostasis of prion protein.
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Affiliation(s)
- Joanna E Pankiewicz
- Department of Neurology, New York University School of Medicine, 550 First Avenue, Science Building, Room 1007, New York, NY, 10016, USA.,Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Sandrine Sanchez
- Department of Neurology, New York University School of Medicine, 550 First Avenue, Science Building, Room 1007, New York, NY, 10016, USA
| | - Kent Kirshenbaum
- Department of Chemistry, New York University, New York, NY, 10003, USA
| | - Regina B Kascsak
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, 10314, USA
| | - Richard J Kascsak
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, 10314, USA
| | - Martin J Sadowski
- Department of Neurology, New York University School of Medicine, 550 First Avenue, Science Building, Room 1007, New York, NY, 10016, USA. .,Department of Psychiatry, New York University School of Medicine, New York, NY, 10016, USA. .,Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA.
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Translational inhibition of APP by Posiphen: Efficacy, pharmacodynamics, and pharmacokinetics in the APP/PS1 mouse. ALZHEIMERS & DEMENTIA-TRANSLATIONAL RESEARCH & CLINICAL INTERVENTIONS 2018; 4:37-45. [PMID: 29955650 PMCID: PMC6021259 DOI: 10.1016/j.trci.2017.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Introduction Translational inhibition of amyloid precursor protein (APP) by Posiphen has been shown to reduce APP and its fragments in cell culture, animal models, and mildly cognitively impaired patients, making it a promising drug candidate for the treatment of Alzheimer's disease. Methods We used a mouse model of Alzheimer's disease (APP/presenilin-1) to examine Posiphen's efficacy, pharmacodynamics, and pharmacokinetics. Results Posiphen treatment normalized impairments in spatial working memory, contextual fear learning, and synaptic function in APP/presenilin-1 mice, without affecting their visual acuity, motor skills, or motivation and without affecting wild-type mice. Posiphen had a prolonged effect in reducing APP and all related peptides for at least 9 hours after the last dose. Its concentration was higher in the brain than in plasma, and the most abundant metabolite was N8-norPosiphen. Discussion This is the first study demonstrating the therapeutic efficacy of inhibiting the translation of APP and its fragments in an Alzheimer's disease model.
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11
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Pankiewicz JE, Sadowski MJ. Editorial: Translational Control of APP Expression for Alzheimer Disease Therapy. ANNALS OF PHARMACOLOGY AND PHARMACEUTICS 2017; 2:1078. [PMID: 30288489 PMCID: PMC6168206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Joanna E. Pankiewicz
- Department of Neurology, New York University School of Medicine, New York, NY 10016
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016
| | - Martin J. Sadowski
- Department of Neurology, New York University School of Medicine, New York, NY 10016
- Department of Psychiatry, New York University School of Medicine, New York, NY 10016
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016
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12
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Angelica tenuissima Nakai Ameliorates Cognitive Impairment and Promotes Neurogenesis in Mouse Model of Alzheimer’s Disease. Chin J Integr Med 2017; 24:378-384. [DOI: 10.1007/s11655-017-2812-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Indexed: 12/28/2022]
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13
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Pankiewicz JE, Baquero-Buitrago J, Sanchez S, Lopez-Contreras J, Kim J, Sullivan PM, Holtzman DM, Sadowski MJ. APOE Genotype Differentially Modulates Effects of Anti-Aβ, Passive Immunization in APP Transgenic Mice. Mol Neurodegener 2017; 12:12. [PMID: 28143566 PMCID: PMC5282859 DOI: 10.1186/s13024-017-0156-1] [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: 08/30/2016] [Accepted: 01/24/2017] [Indexed: 11/11/2022] Open
Abstract
Background APOE genotype is the foremost genetic factor modulating β-amyloid (Aβ) deposition and risk of sporadic Alzheimer’s disease (AD). Here we investigated how APOE genotype influences response to anti-Aβ immunotherapy. Methods APPSW/PS1dE9 (APP) transgenic mice with targeted replacement of the murine Apoe gene for human APOE alleles received 10D5 anti-Aβ or TY11-15 isotype control antibodies between the ages of 12 and 15 months. Results Anti-Aβ immunization decreased both the load of fibrillar plaques and the load of Aβ immunopositive plaques in mice of all APOE backgrounds. Although the relative reduction in parenchymal Aβ plaque load was comparable across all APOE genotypes, APP/ε4 mice showed the greatest reduction in the absolute Aβ plaque load values, given their highest baseline. The immunization stimulated phagocytic activation of microglia, which magnitude adjusted for the post-treatment plaque load was the greatest in APP/ε4 mice implying association between the ε4 allele and impaired Aβ phagocytosis. Perivascular hemosiderin deposits reflecting ensued microhemorrhages were associated with vascular Aβ (VAβ) and ubiquitously present in control mice of all APOE genotypes, although in APP/ε3 mice their incidence was the lowest. Anti-Aβ immunization significantly reduced VAβ burden but increased the number of hemosiderin deposits across all APOE genotypes with the strongest and the weakest effect in APP/ε2 and APP/ε3 mice, respectively. Conclusions Our studies indicate that APOE genotype differentially modulates microglia activation and Aβ plaque load reduction during anti-Aβ immunotherapy. The APOE ε3 allele shows strong protective effect against immunotherapy associated microhemorrhages; while, conversely, the APOE ε2 allele increases risk thereof. Electronic supplementary material The online version of this article (doi:10.1186/s13024-017-0156-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joanna E Pankiewicz
- Department of Neurology, New York University School of Medicine, New York, NY, 10016, USA.,Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Jairo Baquero-Buitrago
- Department of Neurology, New York University School of Medicine, New York, NY, 10016, USA
| | - Sandrine Sanchez
- Department of Neurology, New York University School of Medicine, New York, NY, 10016, USA
| | | | - Jungsu Kim
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Department of Neuroscience, Mayo Clinic College of Medicine, Jacksonville, FL, 32224, USA
| | - Patrick M Sullivan
- Department of Medicine (Geriatrics), Duke University School of Medicine, Durham, NC, 27710, USA.,Durham VA Medical Center's Geriatric Research, Education, and Clinical Center, Durham, NC, 27710, USA
| | - David M Holtzman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Martin J Sadowski
- Department of Neurology, New York University School of Medicine, New York, NY, 10016, USA. .,Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA. .,Department of Psychiatry, New York University School of Medicine, New York, NY, 10016, USA.
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14
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Devi L, Ohno M. Effects of BACE1 haploinsufficiency on APP processing and Aβ concentrations in male and female 5XFAD Alzheimer mice at different disease stages. Neuroscience 2015; 307:128-37. [PMID: 26314636 DOI: 10.1016/j.neuroscience.2015.08.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/14/2015] [Accepted: 08/18/2015] [Indexed: 11/28/2022]
Abstract
β-Site APP-cleaving enzyme 1 (BACE1) initiates the generation of amyloid-β (Aβ), thus representing a prime therapeutic target for Alzheimer's disease (AD). Previous work including ours has used BACE1 haploinsufficiency (BACE1(+/-); i.e., 50% reduction) as a therapeutic relevant model to evaluate the efficacy of partial β-secretase inhibition. However, it is unclear whether the extent of Aβ reductions in amyloid precursor protein (APP) transgenic mice with BACE1(+/-) gene ablation may vary with sex or disease progression. Here, we compared the impacts of BACE1 haploinsufficiency on Aβ concentrations and APP processing in 5XFAD Alzheimer mice (1) between males and females and (2) between different stages with moderate and robust Aβ accumulation. First, male and female 5XFAD mice at 6-7 months of age showed equivalent levels of Aβ, BACE1, full-length APP and its metabolites. BACE1 haploinsufficiency significantly lowered soluble Aβ oligomers, total Aβ42 levels and plaque burden in 5XFAD mouse brains irrespective of sex. Furthermore, there was no sex difference in reductions of β-cleavage products of APP (C99 and sAPPβ) found in BACE1(+/-)·5XFAD mice relative to BACE1(+/+)·5XFAD controls. Meanwhile, APP and sAPPα levels in BACE1(+/-)·5XFAD mice were higher than those of 5XFAD controls regardless of sex. Based on these observations, we next combined male and female data to examine the effects of BACE1 haploinsufficiency in 5XFAD mice at 12-14 months of age, as compared with those in 6-7-month-old 5XFAD mice. Oligomeric Aβ and C99 levels were dramatically elevated in older 5XFAD mice. Although the β-metabolites of APP were significantly reduced by BACE1 haploinsufficiency in both age groups, high levels of these toxic amyloidogenic fragments remained in 12-14-month-old BACE1(+/-)·5XFAD mice. The present findings are consistent with our previous behavioral data showing that BACE1 haploinsufficiency rescues memory deficits in 5XFAD mice irrespective of sex but only in the younger age group.
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Affiliation(s)
- L Devi
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA
| | - M Ohno
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, USA; Department of Psychiatry, New York University Langone Medical Center, New York, NY, USA.
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15
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Borreca A, Gironi K, Amadoro G, Ammassari-Teule M. Opposite Dysregulation of Fragile-X Mental Retardation Protein and Heteronuclear Ribonucleoprotein C Protein Associates with Enhanced APP Translation in Alzheimer Disease. Mol Neurobiol 2015; 53:3227-3234. [PMID: 26048669 DOI: 10.1007/s12035-015-9229-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 05/21/2015] [Indexed: 01/09/2023]
Abstract
Amyloid precursor protein (APP) is overexpressed in familiar and sporadic Alzheimer Disease (AD) patients suggesting that, in addition to abnormalities in APP cleavage, enhanced levels of APP full length might contribute to the pathology. Based on data showing that the two RNA binding proteins (RBPs), Fragile-X Mental Retardation Protein (FMRP) and heteronuclear Ribonucleoprotein C (hnRNP C), exert an opposite control on APP translation, we have analyzed whether expression and translation of these two RBPs vary in relation to changes in APP protein and mRNA levels in the AD brain at 1, 3, and 6 months of age. Here, we show that, as expected, human APP is overexpressed in hippocampal total extract from Tg2576 mice at all age points. APP overexpression, however, is not stable over time but reaches its maximal level in 1-month-old mutants in association with the stronger (i) reduction of FMRP and (ii) augmentation of hnRNP C. APP levels then decrease progressively as a function of age in close relationship with the gradual normalization of FMRP and hnRNP C levels. Consistent with the mouse data, expression of FMRP and hnRNP C are, respectively, decreased and increased in hippocampal synaptosomes from sporadic AD patients. Our findings identify two RBP targets that might be manipulated for reducing abnormally elevated levels of APP in the AD brain, with the hypothesis that acting upstream of amyloidogenic processing might contribute to attenuate the amyloid burden.
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Affiliation(s)
- Antonella Borreca
- Institute of Cellular Biology and Neurobiology (IBCN), Consiglio Nazionale delle Ricerche, Via Del Fosso di Fiorano, 64 00143, Rome, Italy
| | - Katia Gironi
- University of Rome, La Sapienza. Piazza Aldo Moro, Rome, Italy
| | - Giusy Amadoro
- Institute of Translational Pharmacology (IFT)-National Research Council (CNR), Via Fosso del Cavaliere, 100-00133, Rome, Italy.,European Brain Research Institute (EBRI), Via del Fosso di Fiorano, 64-65 00143, Rome, Italy
| | - Martine Ammassari-Teule
- Institute of Cellular Biology and Neurobiology (IBCN), Consiglio Nazionale delle Ricerche, Via Del Fosso di Fiorano, 64 00143, Rome, Italy. .,Fondazione Santa Lucia, Via del Fosso di Fiorano, 64 00143, Rome, Italy.
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16
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Determining binding sites of polycyclic aromatic small molecule-based amyloid-beta peptide aggregation modulators using sequence-specific antibodies. Anal Biochem 2015; 470:61-70. [DOI: 10.1016/j.ab.2014.10.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/21/2014] [Accepted: 10/27/2014] [Indexed: 12/22/2022]
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Abstract
Many lines of evidence support that β-amyloid (Aβ) peptides play an important role in Alzheimer's disease (AD), the most common cause of dementia. But despite much effort the molecular mechanisms of how Aβ contributes to AD remain unclear. While Aβ is generated from its precursor protein throughout life, the peptide is best known as the main component of amyloid plaques, the neuropathological hallmark of AD. Reduction in Aβ has been the major target of recent experimental therapies against AD. Unfortunately, human clinical trials targeting Aβ have not shown the hoped-for benefits. Thus, doubts have been growing about the role of Aβ as a therapeutic target. Here we review evidence supporting the involvement of Aβ in AD, highlight the importance of differentiating between various forms of Aβ, and suggest that a better understanding of Aβ's precise pathophysiological role in the disease is important for correctly targeting it for potential future therapy.
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Affiliation(s)
- Gunnar K. Gouras
- />Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Tomas T. Olsson
- />Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Oskar Hansson
- />Clinical Memory Research Unit, Clinical Sciences Malmö, Lund University, Lund, Sweden
- />Memory Clinic, Skåne University Hospital, Skåne, Sweden
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18
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Asuni AA, Pankiewicz JE, Sadowski MJ. Reply. Ann Neurol 2014; 76:630-1. [DOI: 10.1002/ana.24253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 08/21/2014] [Accepted: 08/21/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Ayodeji A. Asuni
- Department of Neurology; New York University School of Medicine; New York NY
| | - Joanna E. Pankiewicz
- Department of Neurology; New York University School of Medicine; New York NY
- Department of Biochemistry and Molecular Pharmacology; New York University School of Medicine; New York NY
| | - Martin J. Sadowski
- Department of Neurology; New York University School of Medicine; New York NY
- Department of Biochemistry and Molecular Pharmacology; New York University School of Medicine; New York NY
- Department of Psychiatry; New York University School of Medicine; New York NY
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Greig NH, Sambamurti K, Lahiri DK, Becker RE. Amyloid-β precursor protein synthesis inhibitors for Alzheimer's disease treatment. Ann Neurol 2014; 76:629-30. [PMID: 25146731 DOI: 10.1002/ana.24254] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 07/01/2014] [Accepted: 08/21/2014] [Indexed: 12/25/2022]
Affiliation(s)
- Nigel H Greig
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD
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Pankiewicz JE, Guridi M, Kim J, Asuni AA, Sanchez S, Sullivan PM, Holtzman DM, Sadowski MJ. Blocking the apoE/Aβ interaction ameliorates Aβ-related pathology in APOE ε2 and ε4 targeted replacement Alzheimer model mice. Acta Neuropathol Commun 2014; 2:75. [PMID: 24972680 PMCID: PMC4174325 DOI: 10.1186/s40478-014-0075-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 06/16/2014] [Indexed: 12/12/2022] Open
Abstract
Accumulation of β-amyloid (Aβ) in the brain is essential to Alzheimer's disease (AD) pathogenesis. Carriers of the apolipoprotein E (APOE) ε4 allele demonstrate greatly increased AD risk and enhanced brain Aβ deposition. In contrast, APOE ε2 allele carries show reduced AD risk, later age of disease onset, and lesser Aβ accumulation. However, it remains elusive whether the apoE2 isoform exerts truly protective effect against Aβ pathology or apoE2 plays deleterious role albeit less pronounced than the apoE4 isoform. Here, we characterized APPSW/PS1dE9/APOE ε2-TR (APP/E2) and APPSW/PS1dE9/APOE ε4-TR (APP/E4) mice, with targeted replacement (TR) of the murine Apoe for human ε2 or ε4 alleles, and used these models to investigate effects of pharmacological inhibition of the apoE/Aβ interaction on Aβ deposition and neuritic degeneration. APP/E2 and APP/E4 mice replicate differential effect of human apoE isoforms on Aβ pathology with APP/E4 mice showing a several-fold greater load of Aβ plaques, insoluble brain Aβ levels, Aβ oligomers, and density of neuritic plaques than APP/E2 mice. Furthermore, APP/E4 mice, but not APP/E2 mice, exhibit memory impairment on object recognition and radial arm maze tests. Between the age of 6 and 10 months APP/E2 and APP/E4 mice received treatment with Aβ12-28P, a non-toxic, synthetic peptide homologous to the apoE binding motif within the Aβ sequence, which competitively blocks the apoE/Aβ interaction. In both lines, the treatment significantly reduced brain Aβ accumulation, co-accumulation of apoE within Aβ plaques, and neuritic degeneration, and prevented memory deficit in APP/E4 mice. These results indicate that both apoE2 and apoE4 isoforms contribute to Aβ deposition and future therapies targeting the apoE/Aβ interaction could produce favorable outcome in APOE ε2 and ε4 allele carriers.
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