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Echeverria V, Mendoza C, Iarkov A. Nicotinic acetylcholine receptors and learning and memory deficits in Neuroinflammatory diseases. Front Neurosci 2023; 17:1179611. [PMID: 37255751 PMCID: PMC10225599 DOI: 10.3389/fnins.2023.1179611] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 04/07/2023] [Indexed: 06/01/2023] Open
Abstract
Animal survival depends on cognitive abilities such as learning and memory to adapt to environmental changes. Memory functions require an enhanced activity and connectivity of a particular arrangement of engram neurons, supported by the concerted action of neurons, glia, and vascular cells. The deterioration of the cholinergic system is a common occurrence in neurological conditions exacerbated by aging such as traumatic brain injury (TBI), posttraumatic stress disorder (PTSD), Alzheimer's disease (AD), and Parkinson's disease (PD). Cotinine is a cholinergic modulator with neuroprotective, antidepressant, anti-inflammatory, antioxidant, and memory-enhancing effects. Current evidence suggests Cotinine's beneficial effects on cognition results from the positive modulation of the α7-nicotinic acetylcholine receptors (nAChRs) and the inhibition of the toll-like receptors (TLRs). The α7nAChR affects brain functions by modulating the function of neurons, glia, endothelial, immune, and dendritic cells and regulates inhibitory and excitatory neurotransmission throughout the GABA interneurons. In addition, Cotinine acting on the α7 nAChRs and TLR reduces neuroinflammation by inhibiting the release of pro-inflammatory cytokines by the immune cells. Also, α7nAChRs stimulate signaling pathways supporting structural, biochemical, electrochemical, and cellular changes in the Central nervous system during the cognitive processes, including Neurogenesis. Here, the mechanisms of memory formation as well as potential mechanisms of action of Cotinine on memory preservation in aging and neurological diseases are discussed.
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Affiliation(s)
- Valentina Echeverria
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Concepción, Chile
- Research and Development Department, Bay Pines VAHCS, Bay Pines, FL, United States
| | - Cristhian Mendoza
- Facultad de Odontologia y Ciencias de la Rehabilitacion, Universidad San Sebastián, Concepción, Chile
| | - Alex Iarkov
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Concepción, Chile
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Foret MK, Lincoln R, Do Carmo S, Cuello AC, Cosa G. Connecting the "Dots": From Free Radical Lipid Autoxidation to Cell Pathology and Disease. Chem Rev 2020; 120:12757-12787. [PMID: 33211489 DOI: 10.1021/acs.chemrev.0c00761] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Our understanding of lipid peroxidation in biology and medicine is rapidly evolving, as it is increasingly implicated in various diseases but also recognized as a key part of normal cell function, signaling, and death (ferroptosis). Not surprisingly, the root and consequences of lipid peroxidation have garnered increasing attention from multiple disciplines in recent years. Here we "connect the dots" between the fundamental chemistry underpinning the cascade reactions of lipid peroxidation (enzymatic or free radical), the reactive nature of the products formed (lipid-derived electrophiles), and the biological targets and mechanisms associated with these products that culminate in cellular responses. We additionally bring light to the use of highly sensitive, fluorescence-based methodologies. Stemming from the foundational concepts in chemistry and biology, these methodologies enable visualizing and quantifying each reaction in the cascade in a cellular and ultimately tissue context, toward deciphering the connections between the chemistry and physiology of lipid peroxidation. The review offers a platform in which the chemistry and biomedical research communities can access a comprehensive summary of fundamental concepts regarding lipid peroxidation, experimental tools for the study of such processes, as well as the recent discoveries by leading investigators with an emphasis on significant open questions.
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Affiliation(s)
- Morgan K Foret
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Richard Lincoln
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, Canada H3A 0B8
| | - Sonia Do Carmo
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6.,Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada H3A 0C7.,Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H3A 2B4
| | - Gonzalo Cosa
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, Canada H3A 0B8
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Boiangiu RS, Mihasan M, Gorgan DL, Stache BA, Petre BA, Hritcu L. Cotinine and 6-Hydroxy-L-Nicotine Reverses Memory Deficits and Reduces Oxidative Stress in Aβ 25-35-Induced Rat Model of Alzheimer's Disease. Antioxidants (Basel) 2020; 9:E768. [PMID: 32824768 PMCID: PMC7465470 DOI: 10.3390/antiox9080768] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/08/2020] [Accepted: 08/13/2020] [Indexed: 12/15/2022] Open
Abstract
The nicotinic derivatives, cotinine (COT), and 6-hydroxy-L-nicotine (6HLN), showed promising cognitive-improving effects without exhibiting the nicotine's side-effects. Here, we investigated the impact of COT and 6HLN on memory impairment and the oxidative stress in the Aβ25-35-induced rat model of Alzheimer's disease (AD). COT and 6HLN were chronically administered to Aβ25-35-treated rats, and their memory performances were assessed using in vivo tasks (Y-maze, novel object recognition, and radial arm maze). By using in silico tools, we attempted to associate the behavioral outcomes with the calculated binding potential of these nicotinic compounds in the allosteric sites of α7 and α4β2 subtypes of the nicotinic acetylcholine receptors (nAChRs). The oxidative status and acetylcholinesterase (AChE) activity were determined from the hippocampal tissues. RT-qPCR assessed bdnf, arc, and il-1β mRNA levels. Our data revealed that COT and 6HLN could bind to α7 and α4β2 nAChRs with similar or even higher affinity than nicotine. Consequently, the treatment exhibited a pro-cognitive, antioxidant, and anti-AChE profile in the Aβ25-35-induced rat model of AD. Finally, RT-qPCR analysis revealed that COT and 6HLN positively modulated the bdnf, arc, and il-1β genes expression. Therefore, these nicotinic derivatives that act on the cholinergic system might represent a promising choice to ameliorate AD conditions.
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Affiliation(s)
- Razvan Stefan Boiangiu
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University of Iasi, 700506 Iasi, Romania; (R.S.B.); (M.M.); (D.L.G.); (B.A.S.)
| | - Marius Mihasan
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University of Iasi, 700506 Iasi, Romania; (R.S.B.); (M.M.); (D.L.G.); (B.A.S.)
| | - Dragos Lucian Gorgan
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University of Iasi, 700506 Iasi, Romania; (R.S.B.); (M.M.); (D.L.G.); (B.A.S.)
| | - Bogdan Alexandru Stache
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University of Iasi, 700506 Iasi, Romania; (R.S.B.); (M.M.); (D.L.G.); (B.A.S.)
- Center for Fundamental Research and Experimental Development in Translation Medicine—TRANSCEND, Regional Institute of Oncology, 700483 Iasi, Romania;
| | - Brindusa Alina Petre
- Center for Fundamental Research and Experimental Development in Translation Medicine—TRANSCEND, Regional Institute of Oncology, 700483 Iasi, Romania;
- Department of Chemistry, Faculty of Chemistry, Alexandru Ioan Cuza University of Iasi, 700506 Iasi, Romania
| | - Lucian Hritcu
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University of Iasi, 700506 Iasi, Romania; (R.S.B.); (M.M.); (D.L.G.); (B.A.S.)
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Liu C, Lu D, You X, Shi G, Deng J, Zhou T. Carbon dots sensitized lanthanide infinite coordination polymer nanoparticles: Towards ratiometric fluorescent sensing of cerebrospinal Aβ monomer as a biomarker for Alzheimer's disease. Anal Chim Acta 2020; 1105:147-154. [PMID: 32138913 DOI: 10.1016/j.aca.2020.01.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 12/28/2019] [Accepted: 01/09/2020] [Indexed: 12/31/2022]
Abstract
Herein, a novel ratiometric fluorescent probe based on CDs@Eu/GMP ICP nanoparticles was developed for the detection of Aβ monomer in rat as a biomarker for Alzheimer's disease (AD) by fully exploring the competitive coordination interaction and by taking advantage of excellent optical property of carbon dots sensitized lanthanide infinite coordination polymer (ICP) nanoparticles. The carbon dots (CDs) with abundant functional groups were encapsulated into Eu/GMP ICPs through self-adaptive chemistry, which could not only sensitize the red fluorescence of Eu/GMP ICPs effectively, but also act as an internal reference for self-correction. In the absence of Cu2+, the as-formed CDs@Eu/GMP ICPs exhibited the characteristic emission of CDs at 400 nm and strong emission of Eu3+ at 592 nm, 615 nm, 650 nm and 694 nm. With the addition of Cu2+, the red fluorescence of Eu3+ decreased due to the coordination interaction between CDs and Cu2+, thus destroyed the antenna effect. After the subsequent addition of Aβ monomer, the specific binding occurred between Cu2+ and Aβ monomer, and then the red fluorescence of Eu3+ restored again. During this process, the fluorescence of CDs remained unchanged, thus could be used as an internal reference to cancel out the environmental fluctuation and was more adaptive for the detection of Aβ monomer in biological fluids. The method demonstrated here was highly sensitive, free from the interference of other species in rat brain, the in vivo analysis of Aβ monomer in CSF and different brain regions from normal rats and Alzheimer's rats could be realized, which was of great significance for better understanding the mechanism of AD and paving the way to understand the chemical essence involved in AD.
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Affiliation(s)
- Chang Liu
- School of Ecological and Environmental Sciences, Shanghai Key Lab for Urban Ecological Process and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China; Institute of Eco-Chongming, 3663 Zhongshan Road, Shanghai, 200062, China
| | - Dingkun Lu
- School of Ecological and Environmental Sciences, Shanghai Key Lab for Urban Ecological Process and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China; Institute of Eco-Chongming, 3663 Zhongshan Road, Shanghai, 200062, China
| | - Xinrui You
- School of Ecological and Environmental Sciences, Shanghai Key Lab for Urban Ecological Process and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China; Institute of Eco-Chongming, 3663 Zhongshan Road, Shanghai, 200062, China
| | - Guoyue Shi
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
| | - Jingjing Deng
- School of Ecological and Environmental Sciences, Shanghai Key Lab for Urban Ecological Process and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China; Institute of Eco-Chongming, 3663 Zhongshan Road, Shanghai, 200062, China.
| | - Tianshu Zhou
- School of Ecological and Environmental Sciences, Shanghai Key Lab for Urban Ecological Process and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China; Institute of Eco-Chongming, 3663 Zhongshan Road, Shanghai, 200062, China.
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Mietlicki-Baase EG. Amylin in Alzheimer's disease: Pathological peptide or potential treatment? Neuropharmacology 2018; 136:287-297. [PMID: 29233636 PMCID: PMC5994175 DOI: 10.1016/j.neuropharm.2017.12.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 12/06/2017] [Accepted: 12/07/2017] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease for which we currently lack effective treatments or a cure. The pancreatic peptide hormone amylin has recently garnered interest as a potential pharmacological target for the treatment of AD. A number of studies have demonstrated that amylin and amylin analogs like the FDA-approved diabetes drug pramlintide can reduce amyloid burden in the brain and improve cognitive symptoms of AD. However, other data suggest that amylin may have pathological effects in AD due to its propensity to misfold and aggregate under certain conditions. Here, the literature supporting a beneficial versus harmful role of amylin in AD is reviewed. Additionally, several critical gaps in the literature are discussed, such as our limited understanding of the amylin system during aging and in disease states, as well as complexities of amylin receptor signaling and of changing pathophysiology during AD progression that might underlie the seemingly conflicting or contradictory results in the amylin/AD literature. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'
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Affiliation(s)
- Elizabeth G Mietlicki-Baase
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, State University of New York at Buffalo, Buffalo, NY 14214, USA.
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Zhang L, Trushin S, Christensen TA, Tripathi U, Hong C, Geroux RE, Howell KG, Poduslo JF, Trushina E. Differential effect of amyloid beta peptides on mitochondrial axonal trafficking depends on their state of aggregation and binding to the plasma membrane. Neurobiol Dis 2018; 114:1-16. [PMID: 29477640 PMCID: PMC5926207 DOI: 10.1016/j.nbd.2018.02.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 01/03/2018] [Accepted: 02/07/2018] [Indexed: 12/20/2022] Open
Abstract
Inhibition of mitochondrial axonal trafficking by amyloid beta (Aβ) peptides has been implicated in early pathophysiology of Alzheimer's Disease (AD). Yet, it remains unclear whether the loss of motility inevitably induces the loss of mitochondrial function, and whether restoration of axonal trafficking represents a valid therapeutic target. Moreover, while some investigations identify Aβ oligomers as the culprit of trafficking inhibition, others propose that fibrils play the detrimental role. We have examined the effect of a panel of Aβ peptides with different mutations found in familial AD on mitochondrial motility in primary cortical mouse neurons. Peptides with higher propensity to aggregate inhibit mitochondrial trafficking to a greater extent with fibrils inducing the strongest inhibition. Binding of Aβ peptides to the plasma membrane was sufficient to induce trafficking inhibition where peptides with reduced plasma membrane binding and internalization had lesser effect on mitochondrial motility. We also found that Aβ peptide with Icelandic mutation A673T affects axonal trafficking of mitochondria but has very low rates of plasma membrane binding and internalization in neurons, which could explain its relatively low toxicity. Inhibition of mitochondrial dynamics caused by Aβ peptides or fibrils did not instantly affect mitochondrial bioenergetic and function. Our results support a mechanism where inhibition of axonal trafficking is initiated at the plasma membrane by soluble low molecular weight Aβ species and is exacerbated by fibrils. Since trafficking inhibition does not coincide with the loss of mitochondrial function, restoration of axonal transport could be beneficial at early stages of AD progression. However, strategies designed to block Aβ aggregation or fibril formation alone without ensuring the efficient clearance of soluble Aβ may not be sufficient to alleviate the trafficking phenotype.
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Affiliation(s)
- Liang Zhang
- Department of Neurology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA.
| | - Sergey Trushin
- Department of Neurology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA.
| | - Trace A Christensen
- Microscopy and Cell Analysis Core Facility, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
| | - Utkarsh Tripathi
- Department of Neurology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA.
| | - Courtney Hong
- Department of Neurology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA
| | - Rachel E Geroux
- Department of Neurology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA.
| | - Kyle G Howell
- Department of Neurology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA; Microscopy and Cell Analysis Core Facility, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
| | - Joseph F Poduslo
- Department of Neurology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA; Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA.
| | - Eugenia Trushina
- Department of Neurology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA.
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Grizzell JA, Patel S, Barreto GE, Echeverria V. Cotinine improves visual recognition memory and decreases cortical Tau phosphorylation in the Tg6799 mice. Prog Neuropsychopharmacol Biol Psychiatry 2017; 78:75-81. [PMID: 28536070 DOI: 10.1016/j.pnpbp.2017.05.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 05/08/2017] [Accepted: 05/08/2017] [Indexed: 11/16/2022]
Abstract
Alzheimer's disease (AD) is associated with the progressive aggregation of hyperphosphorylated forms of the microtubule associated protein Tau in the central nervous system. Cotinine, the main metabolite of nicotine, reduced working memory deficits, synaptic loss, and amyloid β peptide aggregation into oligomers and plaques as well as inhibited the cerebral Tau kinase, glycogen synthase 3β (GSK3β) in the transgenic (Tg)6799 (5XFAD) mice. In this study, the effect of cotinine on visual recognition memory and cortical Tau phosphorylation at the GSK3β sites Serine (Ser)-396/Ser-404 and phospho-CREB were investigated in the Tg6799 and non-transgenic (NT) littermate mice. Tg mice showed short-term visual recognition memory impairment in the novel object recognition test, and higher levels of Tau phosphorylation when compared to NT mice. Cotinine significantly improved visual recognition memory performance increased CREB phosphorylation and reduced cortical Tau phosphorylation. Potential mechanisms underlying theses beneficial effects are discussed.
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Affiliation(s)
- J Alex Grizzell
- Research & Development Service, Bay Pines VA Healthcare System, Bay Pines, FL 33744, USA
| | - Sagar Patel
- Department of Psychology, NeuroNET Research Center, University of Tennessee, Knoxville, TN 37996, USA
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, D.C., Colombia; Center for Biomedical Research, Universidad Autónoma de Chile, Carlos Antúnez 1920, Providencia, Santiago, Chile
| | - Valentina Echeverria
- Research & Development Service, Bay Pines VA Healthcare System, Bay Pines, FL 33744, USA; Fac. Cs de la Salud, Universidad San Sebastián, Lientur 1457, Concepción 4080871, Chile.
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Das AK, Pandit R, Maiti S. Effect of amyloids on the vesicular machinery: implications for somatic neurotransmission. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0187. [PMID: 26009766 DOI: 10.1098/rstb.2014.0187] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Certain neurodegenerative diseases are thought to be initiated by the aggregation of amyloidogenic proteins. However, the mechanism underlying toxicity remains obscure. Most of the suggested mechanisms are generic in nature and do not directly explain the neuron-type specific lesions observed in many of these diseases. Some recent reports suggest that the toxic aggregates impair the synaptic vesicular machinery. This may lead to an understanding of the neuron-type specificity observed in these diseases. A disruption of the vesicular machinery can also be deleterious for extra-synaptic, especially somatic, neurotransmission (common in serotonergic and dopaminergic systems which are specifically affected in Alzheimer's disease (AD) and Parkinson's disease (PD), respectively), though this relationship has remained unexplored. In this review, we discuss amyloid-induced damage to the neurotransmitter vesicular machinery, with an eye on the possible implications for somatic exocytosis. We argue that the larger size of the system, and the availability of multi-photon microscopy techniques for directly visualizing monoamines, make the somatic exocytosis machinery a more tractable model for understanding the effect of amyloids on all types of vesicular neurotransmission. Indeed, exploring this neglected connection may not just be important, it may be a more fruitful route for understanding AD and PD.
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Affiliation(s)
- Anand Kant Das
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 400005, India
| | - Rucha Pandit
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 400005, India
| | - Sudipta Maiti
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 400005, India
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Li P, Beck WD, Callahan PM, Terry AV, Bartlett MG. Pharmacokinetics of cotinine in rats: a potential therapeutic agent for disorders of cognitive function. Pharmacol Rep 2014; 67:494-500. [PMID: 25933960 DOI: 10.1016/j.pharep.2014.12.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 11/24/2014] [Accepted: 12/05/2014] [Indexed: 02/09/2023]
Abstract
BACKGROUND Attention has been paid to cotinine (COT), one of the major metabolites of nicotine (NIC), for its pro-cognitive effects and potential therapeutic activities against Alzheimer's disease (AD) and other types of cognitive impairment. In order to facilitate pharmacological and toxicological studies on COT for its pro-cognitive activities, we conducted a pharmacokinetic (PK) study of COT in rats, providing important oral and intravenously (iv) PK information. METHODS In this study, plasma samples were obtained up to 48 h after COT was dosed to rats orally and iv at a dose of 3mg/kg. Plasma samples were prepared and analyzed using a sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) bioanalytical method, providing concentration profiles of COT and metabolites after oral and iv administrations. RESULTS The data were fitted into a one-compartment model and a two-compartment model for the oral and iv groups, respectively, providing important PK information for COT including PK profiles, half-life, clearance and bioavailability. The results suggested fast absorption, slow elimination and high bioavailability of COT in rats. CONCLUSIONS Several important facts about the PK properties in rats suggested COT could be a potential pro-cognitive agent. Information about the pharmacokinetics of COT in rats revealed in this study is of great importance for the future studies on COT or potential COT analogs as agents for improving cognition.
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Affiliation(s)
- Pei Li
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, Athens, USA
| | - Wayne D Beck
- Department of Pharmacology and Toxicology, Georgia Regents University, Augusta, USA
| | - Patrick M Callahan
- Department of Pharmacology and Toxicology, Georgia Regents University, Augusta, USA; Small Animal Behavior Core, Georgia Regents University, Augusta, USA
| | - Alvin V Terry
- Department of Pharmacology and Toxicology, Georgia Regents University, Augusta, USA; Small Animal Behavior Core, Georgia Regents University, Augusta, USA
| | - Michael G Bartlett
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, Athens, USA.
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Yu Y, Zhang L, Li C, Sun X, Tang D, Shi G. A Method for Evaluating the Level of Soluble β-Amyloid(1-40/1-42)in Alzheimer’s Disease Based on the Binding of Gelsolin to β-Amyloid Peptides. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201405001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Yu Y, Zhang L, Li C, Sun X, Tang D, Shi G. A method for evaluating the level of soluble β-amyloid(1-40/1-42) in Alzheimer's disease based on the binding of gelsolin to β-amyloid peptides. Angew Chem Int Ed Engl 2014; 53:12832-5. [PMID: 25244702 DOI: 10.1002/anie.201405001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 07/10/2014] [Indexed: 01/27/2023]
Abstract
In the present work, a new electrochemical strategy for the sensitive and specific detection of soluble β-amyloid Aβ(1-40/1-42) peptides in a rat model of Alzheimer's disease (AD) is described. In contrast to previous antibody-based methods, β-amyloid(1-40/1-42) was quantified based on its binding to gelsolin, a secretory protein present in the cerebrospinal fluid (CSF) and plasma. The level of soluble β-amyloid peptides in the CSF and various brain regions were found with this method to be lower in rats with AD than in normal rats.
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Affiliation(s)
- Yanyan Yu
- Department of Pharmaceutical Analysis, Xuzhou Medical College, Xuzhou 221004 (China); Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, Xuzhou 221004 (China)
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Ghasemi R, Zarifkar A, Rastegar K, Maghsoudi N, Moosavi M. Repeated intra-hippocampal injection of beta-amyloid 25–35 induces a reproducible impairment of learning and memory: Considering caspase-3 and MAPKs activity. Eur J Pharmacol 2014; 726:33-40. [DOI: 10.1016/j.ejphar.2013.11.034] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 11/27/2013] [Accepted: 11/27/2013] [Indexed: 12/29/2022]
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13
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Kang M, Kim SY, An SSA, Ju YR. Characterizing affinity epitopes between prion protein and β-amyloid using an epitope mapping immunoassay. Exp Mol Med 2013; 45:e34. [PMID: 23907583 PMCID: PMC3789258 DOI: 10.1038/emm.2013.63] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Revised: 04/12/2013] [Accepted: 05/02/2013] [Indexed: 12/11/2022] Open
Abstract
Cellular prion protein, a membrane protein, is expressed in all mammals. Prion protein is also found in human blood as an anchorless protein, and this protein form is one of the many potential sources of misfolded prion protein replication during transmission. Many studies have suggested that β-amyloid1-42 oligomer causes neurotoxicity associated with Alzheimer's disease, which is mediated by the prion protein that acts as a receptor and regulates the hippocampal potentiation. The prevention of the binding of these proteins has been proposed as a possible preventative treatment for Alzheimer's disease; therefore, a greater understanding of the binding hot-spots between the two molecules is necessary. In this study, the epitope mapping immunoassay was employed to characterize binding epitopes within the prion protein and complementary epitopes in β-amyloid. Residues 23-39 and 93-119 in the prion protein were involved in binding to β-amyloid1-40 and 1-42, and monomers of this protein interacted with prion protein residues 93-113 and 123-166. Furthermore, β-amyloid antibodies against the C-terminus detected bound β-amyloid1-42 at residues 23-40, 104-122 and 159-175. β-Amyloid epitopes necessary for the interaction with prion protein were not determined. In conclusion, charged clusters and hydrophobic regions of the prion protein were involved in binding to β-amyloid1-40 and 1-42. The 3D structure appears to be necessary for β-amyloid to interact with prion protein. In the future, these binding sites may be utilized for 3D structure modeling, as well as for the pharmaceutical intervention of Alzheimer's disease.
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Affiliation(s)
- Mino Kang
- Department of Bionanotechnology, Gachon University, Gyeonggi, Korea
| | - Su Yeon Kim
- Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Korea Centers for Disease Control and Prevention, Osong, Republic of Korea
| | - Seong Soo A An
- Department of Bionanotechnology, Gachon University, Gyeonggi, Korea
| | - Young Ran Ju
- Division of Zoonoses, Center for Immunology and Pathology, National Institute of Health, Korea Centers for Disease Control and Prevention, Osong, Republic of Korea
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Sivilia S, Lorenzini L, Giuliani A, Gusciglio M, Fernandez M, Baldassarro VA, Mangano C, Ferraro L, Pietrini V, Baroc MF, Viscomi AR, Ottonello S, Villetti G, Imbimbo BP, Calzà L, Giardino L. Multi-target action of the novel anti-Alzheimer compound CHF5074: in vivo study of long term treatment in Tg2576 mice. BMC Neurosci 2013. [PMID: 23560952 DOI: 10.1186/1471-2202-14.44] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Alzheimer disease is a multifactorial disorder characterized by the progressive deterioration of neuronal networks. The pathological hallmarks includes extracellular amyloid plaques and intraneuronal neurofibrillary tangles, but the primary cause is only partially understood. Thus, there is growing interest in developing agents that might target multiple mechanisms leading to neuronal degeneration. CHF5074 is a nonsteroidal anti-inflammatory derivative that has been shown to behave as a γ-secretase modulator in vitro and to inhibit plaque deposition and to reverse memory deficit in vivo in transgenic mouse models of Alzheimer's disease (AD). In the present study, the effects of a long-term (13-month) treatment with CHF5074 on indicators of brain functionality and neurodegeneration in transgenic AD mice (Tg2576) have been assessed and compared with those induced by a prototypical γ-secretase inhibitor (DAPT). RESULTS To this end, plaque-free, 6-month-old Tg2576 mice and wild-type littermates were fed with a diet containing CHF5074 (125 and 375 ppm/day), DAPT (375 ppm/day) or vehicle for 13 months. The measured indicators included object recognition memory, amyloid burden, brain oligomeric and plasma Aβ levels, intraneuronal Aβ, dendritic spine density/morphology, neuronal cyclin A positivity and activated microglia. Tg2576 mice fed with standard diet displayed an impairment of recognition memory. This deficit was completely reverted by the higher dose of CHF5074, while no effects were observed in DAPT-treated mice. Similarly, amyloid plaque burden, microglia activation and aberrant cell cycle events were significantly affected by CHF5074, but not DAPT, treatment. Both CHF5074 and DAPT reduced intraneuronal Aβ content, also increasing Aβ40 and Aβ42 plasma levels. CONCLUSIONS This comparative analysis revealed a profoundly diverse range of clinically relevant effects differentiating the multifunctional anti-inflammatory derivative CHF5074 from the γ-secretase inhibitor DAPT and highlighted unique mechanisms and potential targets that may be crucial for neuroprotection in mouse models of AD.
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Affiliation(s)
- Sandra Sivilia
- Department of Veterinary Medicine, University of Bologna, Bologna, Italy
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15
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Sivilia S, Lorenzini L, Giuliani A, Gusciglio M, Fernandez M, Baldassarro VA, Mangano C, Ferraro L, Pietrini V, Baroc MF, Viscomi AR, Ottonello S, Villetti G, Imbimbo BP, Calzà L, Giardino L. Multi-target action of the novel anti-Alzheimer compound CHF5074: in vivo study of long term treatment in Tg2576 mice. BMC Neurosci 2013; 14:44. [PMID: 23560952 PMCID: PMC3626610 DOI: 10.1186/1471-2202-14-44] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 03/14/2013] [Indexed: 02/08/2023] Open
Abstract
Background Alzheimer disease is a multifactorial disorder characterized by the progressive deterioration of neuronal networks. The pathological hallmarks includes extracellular amyloid plaques and intraneuronal neurofibrillary tangles, but the primary cause is only partially understood. Thus, there is growing interest in developing agents that might target multiple mechanisms leading to neuronal degeneration. CHF5074 is a nonsteroidal anti-inflammatory derivative that has been shown to behave as a γ-secretase modulator in vitro and to inhibit plaque deposition and to reverse memory deficit in vivo in transgenic mouse models of Alzheimer’s disease (AD). In the present study, the effects of a long-term (13-month) treatment with CHF5074 on indicators of brain functionality and neurodegeneration in transgenic AD mice (Tg2576) have been assessed and compared with those induced by a prototypical γ-secretase inhibitor (DAPT). Results To this end, plaque-free, 6-month-old Tg2576 mice and wild-type littermates were fed with a diet containing CHF5074 (125 and 375 ppm/day), DAPT (375 ppm/day) or vehicle for 13 months. The measured indicators included object recognition memory, amyloid burden, brain oligomeric and plasma Aβ levels, intraneuronal Aβ, dendritic spine density/morphology, neuronal cyclin A positivity and activated microglia. Tg2576 mice fed with standard diet displayed an impairment of recognition memory. This deficit was completely reverted by the higher dose of CHF5074, while no effects were observed in DAPT-treated mice. Similarly, amyloid plaque burden, microglia activation and aberrant cell cycle events were significantly affected by CHF5074, but not DAPT, treatment. Both CHF5074 and DAPT reduced intraneuronal Aβ content, also increasing Aβ40 and Aβ42 plasma levels. Conclusions This comparative analysis revealed a profoundly diverse range of clinically relevant effects differentiating the multifunctional anti-inflammatory derivative CHF5074 from the γ-secretase inhibitor DAPT and highlighted unique mechanisms and potential targets that may be crucial for neuroprotection in mouse models of AD.
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Affiliation(s)
- Sandra Sivilia
- Department of Veterinary Medicine, University of Bologna, Bologna, Italy
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16
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Takahashi RH, Capetillo-Zarate E, Lin MT, Milner TA, Gouras GK. Accumulation of intraneuronal β-amyloid 42 peptides is associated with early changes in microtubule-associated protein 2 in neurites and synapses. PLoS One 2013; 8:e51965. [PMID: 23372648 PMCID: PMC3553177 DOI: 10.1371/journal.pone.0051965] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Accepted: 11/09/2012] [Indexed: 11/19/2022] Open
Abstract
Pathologic aggregation of β-amyloid (Aβ) peptide and the axonal microtubule-associated protein tau protein are hallmarks of Alzheimer's disease (AD). Evidence supports that Aβ peptide accumulation precedes microtubule-related pathology, although the link between Aβ and tau remains unclear. We previously provided evidence for early co-localization of Aβ42 peptides and hyperphosphorylated tau within postsynaptic terminals of CA1 dendrites in the hippocampus of AD transgenic mice. Here, we explore the relation between Aβ peptide accumulation and the dendritic, microtubule-associated protein 2 (MAP2) in the well-characterized amyloid precursor protein Swedish mutant transgenic mouse (Tg2576). We provide evidence that localized intraneuronal accumulation of Aβ42 peptides is spatially associated with reductions of MAP2 in dendrites and postsynaptic compartments of Tg2576 mice at early ages. Our data support that reduction in MAP2 begins at sites of Aβ42 monomer and low molecular weight oligomer (M/LMW) peptide accumulation. Cumulative evidence suggests that accumulation of M/LMW Aβ42 peptides occurs early, before high molecular weight oligomerization and plaque formation. Since synaptic alteration is the best pathologic correlate of cognitive dysfunction in AD, the spatial association of M/LMW Aβ peptide accumulation with pathology of MAP2 within neuronal processes and synaptic compartments early in the disease process reinforces the importance of intraneuronal Aβ accumulation in AD pathogenesis.
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Affiliation(s)
- Reisuke H. Takahashi
- Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
- * E-mail: (RHT); (GKG)
| | - Estibaliz Capetillo-Zarate
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
| | - Michael T. Lin
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
| | - Teresa A. Milner
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, New York, United States of America
| | - Gunnar K. Gouras
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
- Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, Lund, Sweden
- * E-mail: (RHT); (GKG)
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17
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Cuello AC, Allard S, Ferretti MT. Evidence for the accumulation of Abeta immunoreactive material in the human brain and in transgenic animal models. Life Sci 2012; 91:1141-7. [PMID: 22705309 DOI: 10.1016/j.lfs.2012.05.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 05/11/2012] [Accepted: 05/24/2012] [Indexed: 12/19/2022]
Abstract
In this review we highlight the evidence for an intracellular origin of Abeta (Aβ) amyloid peptides as well as the observations for a pathological accumulation of these peptides in Alzheimer's disease and Down syndrome, as well as in transgenic animal models. We deliberate on the controversy as to whether the intracellular Aβ immunoreactive material is simply an accumulation of unprocessed full length amyloid precursor protein (APP) or a mix of processed APP fragments including Aβ. Finally, we discuss the possible pathological significance of these intracellular APP fragments and the expected future research directions regarding this thought-provoking problem.
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Affiliation(s)
- A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, 3655 Sir William Osler Promenade, Room 1210, Montreal, Quebec, Canada.
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18
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Poduslo JF, Howell KG, Olson NC, Ramirez-Alvarado M, Kandimalla KK. Alzheimer’s Disease Amyloid β-Protein Mutations and Deletions That Define Neuronal Binding/Internalization as Early Stage Nonfibrillar/Fibrillar Aggregates and Late Stage Fibrils. Biochemistry 2012; 51:3993-4003. [DOI: 10.1021/bi300275g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joseph F. Poduslo
- Departments of Neurology, Neuroscience,
and Biochemistry/Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Kyle G. Howell
- Departments of Neurology, Neuroscience,
and Biochemistry/Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Nicole C. Olson
- Departments of Neurology, Neuroscience,
and Biochemistry/Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Marina Ramirez-Alvarado
- Departments of Neurology, Neuroscience,
and Biochemistry/Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Karunya K. Kandimalla
- Departments of Neurology, Neuroscience,
and Biochemistry/Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department of Pharmaceutics,
College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
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19
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Chen H, Epelbaum S, Delatour B. Fiber Tracts Anomalies in APPxPS1 Transgenic Mice Modeling Alzheimer's Disease. J Aging Res 2011; 2011:281274. [PMID: 21912744 PMCID: PMC3170810 DOI: 10.4061/2011/281274] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2011] [Revised: 05/30/2011] [Accepted: 06/28/2011] [Indexed: 11/20/2022] Open
Abstract
Amyloid beta (Aβ) peptides are known to accumulate in the brain of patients with Alzheimer's disease (AD). However, the link between brain amyloidosis and clinical symptoms has not been elucidated and could be mediated by secondary neuropathological alterations such as fiber tracts anomalies. In the present study, we have investigated the impact of Aβ overproduction in APPxPS1 transgenic mice on the integrity of forebrain axonal bundles (corpus callosum and anterior commissure). We found evidence of fiber tract volume reductions in APPxPS1 mice that were associated with an accelerated age-related loss of axonal neurofilaments and a myelin breakdown. The severity of these defects was neither correlated with the density of amyloid plaques nor associated with cell neurodegeneration. Our data suggest that commissural fiber tract alterations are present in Aβ-overproducing transgenic mice and that intracellular Aβ accumulation preceding extracellular deposits may act as a trigger of such morphological anomalies.
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Affiliation(s)
- H Chen
- CNRS, Laboratoire NAMC, UMR 8620, Université Paris-Sud 11, 91405 Orsay, France
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20
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Zeitlin R, Patel S, Burgess S, Arendash GW, Echeverria V. Caffeine induces beneficial changes in PKA signaling and JNK and ERK activities in the striatum and cortex of Alzheimer's transgenic mice. Brain Res 2011; 1417:127-36. [PMID: 21907331 DOI: 10.1016/j.brainres.2011.08.036] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 07/26/2011] [Accepted: 08/14/2011] [Indexed: 02/07/2023]
Abstract
Caffeine intake has been associated with a lower incidence of Alzheimer's disease (AD) in humans. In AD mouse models, caffeine significantly decreases senile plaques and amyloid beta (Aβ) levels while also protecting against or reversing cognitive impairment. To understand the mechanism(s) underlying the protective effects of caffeine against AD pathology, we investigated the effects of a two-week treatment with caffeine (3mg/day) in transgenic (APPswe) mice and non-transgenic (NT) mice on signaling factors involved in neuronal plasticity and survival. We evaluated cAMP-dependent protein kinase A (PKA), phospho-cyclic AMP response-element binding protein (phospho-CREB), and the pro-apoptotic protein kinases extracellular signal-regulated kinase 1/2 (phospho-ERK) and phospho-c-Jun N-terminal kinase 1 (phospho-JNK) in the striatum and frontal cortex of caffeine-treated mice. In the striatum, APPswe control mice exhibited a significant decrease in phospho-CREB, as well as significant increases in phospho-JNK and phospho-ERK in comparison to NT mice. Caffeine treatment stimulated PKA activity, increased phospho-CREB levels, and decreased phospho-JNK and phospho-ERK expression in the striatum of APPswe mice, all of which are thought to be beneficial changes for brain function. Even caffeine-treated NT mice exhibited some of these changes in striatum. In the frontal cortex, caffeine did not significantly increase phospho-CREB and PKA activity, but significantly reduced phospho-JNK and phospho-ERK expression in both APPswe and NT mice. These results suggest that caffeine shifts the balance between neurodegeneration and neuronal survival toward the stimulation of pro-survival cascades and inhibition of pro-apoptotic pathways in the striatum and/or cortex, which may contribute to its beneficial effects against AD.
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Affiliation(s)
- Ross Zeitlin
- Research and Development, Department of Veterans Affairs, Bay Pines VA Healthcare System, Bay Pines, FL 33744, USA
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21
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Mohamed A, Posse de Chaves E. Aβ internalization by neurons and glia. Int J Alzheimers Dis 2011; 2011:127984. [PMID: 21350608 PMCID: PMC3042623 DOI: 10.4061/2011/127984] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Accepted: 12/23/2010] [Indexed: 11/20/2022] Open
Abstract
In the brain, the amyloid β peptide (Aβ) exists extracellularly and inside neurons. The intracellular accumulation of Aβ in Alzheimer's disease brain has been questioned for a long time. However, there is now sufficient strong evidence indicating that accumulation of Aβ inside neurons plays an important role in the pathogenesis of Alzheimer's disease. Intraneuronal Aβ originates from intracellular cleavage of APP and from Aβ internalization from the extracellular milieu. We discuss here the different molecular mechanisms that are responsible for Aβ internalization in neurons and the links between Aβ internalization and neuronal dysfunction and death. A brief description of Aβ uptake by glia is also presented.
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Affiliation(s)
- Amany Mohamed
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada T6G 2H7
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22
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Urano T, Tohda C. Icariin improves memory impairment in Alzheimer's disease model mice (5xFAD) and attenuates amyloid β-induced neurite atrophy. Phytother Res 2011; 24:1658-63. [PMID: 21031624 DOI: 10.1002/ptr.3183] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Essential therapeutic drugs for Alzheimer's disease (AD) have not been developed. Since the neuritic atrophy leading to synaptic losses is one of the critical causes of memory impairment in AD, the effects of several constituents in tonic herbal medicines on neuritic atrophy and memory deficits have been studied. The present study investigated the effects of icariin, a main constituent in Epimedii Herba, a well known tonic crude drug, in an in vitro AD model and transgenic mouse AD model (5xFAD). Amyloid β(1-42)-induced atrophies of axons and dendrites were restored by post-treatment with icariin in rat cortical neurons. Administration of icariin for 8 days (p.o.) improved spatial memory impairment in 5xFAD mice. These novel findings suggest that icariin may improve memory dysfunction in AD and have a potential to extend neurites even when amyloid β-induced neurite atrophy has already occurred.
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Affiliation(s)
- Takuya Urano
- Division of Biofunctional Evaluation, Research Center for Ethnomedicine, Institute of Natural Medicine, University of Toyama, Toyama 930-0194, Japan
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23
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Gouras GK, Tampellini D, Takahashi RH, Capetillo-Zarate E. Intraneuronal beta-amyloid accumulation and synapse pathology in Alzheimer's disease. Acta Neuropathol 2010; 119:523-41. [PMID: 20354705 PMCID: PMC3183823 DOI: 10.1007/s00401-010-0679-9] [Citation(s) in RCA: 240] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 03/23/2010] [Accepted: 03/23/2010] [Indexed: 01/01/2023]
Abstract
The aberrant accumulation of aggregated beta-amyloid peptides (Abeta) as plaques is a hallmark of Alzheimer's disease (AD) neuropathology and reduction of Abeta has become a leading direction of emerging experimental therapies for the disease. The mechanism(s) whereby Abeta is involved in the pathophysiology of the disease remain(s) poorly understood. Initially fibrils, and subsequently oligomers of extracellular Abeta have been viewed as the most important pathogenic form of Abeta in AD. More recently, the intraneuronal accumulation of Abeta has been described in the brain, although technical considerations and its relevance in AD have made this a controversial topic. Here, we review the emerging evidence linking intraneuronal Abeta accumulation to the development of synaptic pathology and plaques in AD, and discuss the implications of intraneuronal beta-amyloid for AD pathology, biology, diagnosis and therapy.
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Affiliation(s)
- Gunnar K Gouras
- Department for Neurology and Neuroscience, Weill Cornell Medical College, New York, NY 10065, USA.
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24
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Hashimoto M, Bogdanovic N, Volkmann I, Aoki M, Winblad B, Tjernberg LO. Analysis of microdissected human neurons by a sensitive ELISA reveals a correlation between elevated intracellular concentrations of Abeta42 and Alzheimer's disease neuropathology. Acta Neuropathol 2010; 119:543-54. [PMID: 20198479 DOI: 10.1007/s00401-010-0661-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 02/19/2010] [Accepted: 02/19/2010] [Indexed: 11/28/2022]
Abstract
In Alzheimer's disease (AD), Purkinje neurons in the cerebellum are spared, while, for instance, pyramidal neurons in the hippocampus are neuropathologically affected. Several lines of evidence suggest that the pathogenesis could be induced by the concentration-dependent polymerization of the amyloid beta-peptide (Abeta) into extracellular oligomers. The role of intracellular Abeta is not fully investigated, but recent data indicate that also this pool could be of importance. Here, we use laser capture microdissection microscopy for isolation of Purkinje neurons from AD cases and controls, and quantify the low levels of intracellular Abeta using a novel and highly sensitive ELISA. Similar to Cornu Ammonis 1 pyramidal neurons, the intracellular levels of the most toxic variant, Abeta42, as well as the Abeta42/Abeta40 ratio, were increased in Purkinje neurons from sporadic AD cases as compared to controls. However, the levels of Abeta42 as well as Abeta40 were clearly lower in Purkinje neurons than in pyramidal neurons. Based on the volume of the captured Purkinje neurons, the intraneuronal concentrations of Abeta42 were calculated to be 200 nM in sporadic AD cases and 90 nM in controls. The corresponding concentrations in pyramidal neurons from hippocampus were 3 muM and 660 nM, respectively. The Abeta40 concentration was not significantly altered in AD cases compared to controls. However, we found ten times higher concentration of Abeta40 in pyramidal neurons (10 muM) compared to Purkinje neurons (1 muM). Finally, we suggest that high concentration of intracellular Abeta42 correlates with vulnerability to AD neuropathology.
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Affiliation(s)
- Masakazu Hashimoto
- Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet and Dainippon Sumitomo Pharma Alzheimer Center (KASPAC), KI-Alzheimer's Disease Research Center, Karolinska Institutet, Novum plan 5, Huddinge, Sweden.
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25
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Poduslo JF, Gilles EJ, Ramakrishnan M, Howell KG, Wengenack TM, Curran GL, Kandimalla KK. HH domain of Alzheimer's disease Abeta provides structural basis for neuronal binding in PC12 and mouse cortical/hippocampal neurons. PLoS One 2010; 5:e8813. [PMID: 20098681 PMCID: PMC2809098 DOI: 10.1371/journal.pone.0008813] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Accepted: 12/22/2009] [Indexed: 11/18/2022] Open
Abstract
A key question in understanding AD is whether extracellular Aβ deposition of parenchymal amyloid plaques or intraneuronal Aβ accumulation initiates the AD process. Amyloid precursor protein (APP) is endocytosed from the cell surface into endosomes where it is cleaved to produce soluble Aβ which is then released into the brain interstitial fluid. Intraneuronal Aβ accumulation is hypothesized to predominate from the neuronal uptake of this soluble extracellular Aβ rather than from ER/Golgi processing of APP. We demonstrate that substitution of the two adjacent histidine residues of Aβ40 results in a significant decrease in its binding with PC12 cells and mouse cortical/hippocampal neurons. These substitutions also result in a dramatic enhancement of both thioflavin-T positive fibril formation and binding to preformed Aβ fibrils while maintaining its plaque-binding ability in AD transgenic mice. Hence, alteration of the histidine domain of Aβ prevented neuronal binding and drove Aβ to enhanced fibril formation and subsequent amyloid plaque deposition - a potential mechanism for removing toxic species of Aβ. Substitution or even masking of these Aβ histidine residues might provide a new therapeutic direction for minimizing neuronal uptake and subsequent neuronal degeneration and maximizing targeting to amyloid plaques.
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Affiliation(s)
- Joseph F Poduslo
- Molecular Neurobiology Laboratory, Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America.
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26
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Khandelwal PJ, Moussa CEH. The Relationship between Parkin and Protein Aggregation in Neurodegenerative Diseases. Front Psychiatry 2010; 1:15. [PMID: 21423426 PMCID: PMC3059628 DOI: 10.3389/fpsyt.2010.00015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 05/10/2010] [Indexed: 12/12/2022] Open
Abstract
The most prominent changes in neurodegenerative diseases are protein accumulation and inclusion formation. Several neurodegenerative diseases, including Alzheimer's, the Synucleinopathies and Tauopathies share several overlapping clinical symptoms manifest in Parkinsonism, cognitive decline and dementia. As degeneration progresses in the disease process, clinical symptoms suggest convergent pathological pathways. Biochemically, protein cleavage, ubiquitination and phosphorylation seem to play fundamental roles in protein aggregation, inclusion formation and inflammatory responses. In the following we provide a synopsis of the current knowledge about protein accumulation and astrogliosis as a common denominator in neurodegenerative diseases, and we propose insights into protein degradation and anti-inflammation. We review the E3-ubiquitin ligase and other possible functions of parkin as a suppressant of inflammatory signs and a strategy to clear amyloid proteins in neurodegenerative diseases.
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Affiliation(s)
- Preeti J Khandelwal
- Department of Neuroscience, Georgetown University Medical Center Washington, DC, USA
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27
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Sorafenib inhibits nuclear factor kappa B, decreases inducible nitric oxide synthase and cyclooxygenase-2 expression, and restores working memory in APPswe mice. Neuroscience 2009; 162:1220-31. [DOI: 10.1016/j.neuroscience.2009.05.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 04/24/2009] [Accepted: 05/07/2009] [Indexed: 11/20/2022]
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28
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Lee LL, Ha H, Chang YT, DeLisa MP. Discovery of amyloid-beta aggregation inhibitors using an engineered assay for intracellular protein folding and solubility. Protein Sci 2009; 18:277-86. [PMID: 19177561 DOI: 10.1002/pro.33] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Genetic and biochemical studies suggest that Alzheimer's disease (AD) is caused by a series of events initiated by the production and subsequent aggregation of the Alzheimer's amyloid beta peptide (Abeta), the so-called amyloid cascade hypothesis. Thus, a logical approach to treating AD is the development of small molecule inhibitors that either block the proteases that generate Abeta from its precursor (beta- and gamma-secretases) or interrupt and/or reverse Abeta aggregation. To identify potent inhibitors of Abeta aggregation, we have developed a high-throughput screen based on an earlier selection that effectively paired the folding quality control feature of the Escherichia coli Tat protein export system with aggregation of the 42-residue AD pathogenesis effecter Abeta42. Specifically, a tripartite fusion between the Tat-dependent export signal ssTorA, the Abeta42 peptide and the beta-lactamase (Bla) reporter enzyme was found to be export incompetent due to aggregation of the Abeta42 moiety. Here, we reasoned that small, cell-permeable molecules that inhibited Abeta42 aggregation would render the ssTorA-Abeta42-Bla chimera competent for Tat export to the periplasm where Bla is active against beta-lactam antibiotics such as ampicillin. Using a fluorescence-based version of our assay, we screened a library of triazine derivatives and isolated four nontoxic, cell-permeable compounds that promoted efficient Tat-dependent export of ssTorA-Abeta42-Bla. Each of these was subsequently shown to be a bona fide inhibitor of Abeta42 aggregation using a standard thioflavin T fibrillization assay, thereby highlighting the utility of our bacterial assay as a useful screen for antiaggregation factors under physiological conditions.
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Affiliation(s)
- Li Ling Lee
- Cornell University, Ithaca, New York 14853, USA
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29
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Shineman DW, Dain AS, Kim ML, Lee VMY. Constitutively active Akt inhibits trafficking of amyloid precursor protein and amyloid precursor protein metabolites through feedback inhibition of phosphoinositide 3-kinase. Biochemistry 2009; 48:3787-94. [PMID: 19236051 DOI: 10.1021/bi802070j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Amyloid-beta (Abeta) peptides, generated through sequential proteolytic cleavage of amyloid precursor protein (APP), aggregate to form amyloid plaques in Alzheimer's disease (AD). Understanding the regulation of Abeta generation and cellular secretion is critical to our understanding of AD pathophysiology. In the present study, we examined the role of the insulin/insulin-like growth factor-1 (IGF-1) signaling pathway in regulating APP trafficking and Abeta secretion. Previous studies have demonstrated that insulin or IGF-1 stimulation can increase Abeta and APP secretion in a phosphoinositide 3-kinase (PI3K) dependent manner. To expand upon these studies and better understand the molecular targets responsible for alterations in APP secretion, we constitutively activated Akt, a downstream component of the insulin/IGF-1 signaling pathway. Counterintuitively, constitutively active Akt (myr-Akt) overexpression produced an opposite effect to insulin/IGF-1 stimulation and inhibited secretion of APP and APP metabolites in multiple cell lines. Myr-Akt overexpression also resulted in increased APP protein stability. Since the insulin/IGF-1 signaling pathway is tightly regulated by feedback inhibition pathways, we hypothesized that myr-Akt overexpression may be inducing feedback inhibition of PI3K, resulting in impaired APP trafficking. In support of this hypothesis, myr-Akt acted at a known node of PI3K inhibition and decreased insulin receptor substrate 1 (IRS1) protein levels. Our studies provide further support for PI3K as a modulator of APP trafficking and demonstrate that overactivation of the insulin/IGF-1 signaling pathway may result in feedback inhibition of PI3K through IRS1 and reduce APP trafficking and Abeta secretion.
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Affiliation(s)
- Diana W Shineman
- Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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Shah SB, Nolan R, Davis E, Stokin GB, Niesman I, Canto I, Glabe C, Goldstein LSB. Examination of potential mechanisms of amyloid-induced defects in neuronal transport. Neurobiol Dis 2009; 36:11-25. [PMID: 19497367 DOI: 10.1016/j.nbd.2009.05.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 05/03/2009] [Accepted: 05/25/2009] [Indexed: 01/31/2023] Open
Abstract
Microtubule-based neuronal transport pathways are impaired during the progression of Alzheimer's disease and other neurodegenerative conditions. However, mechanisms leading to defects in transport remain to be determined. We quantified morphological changes in neuronal cells following treatment with fibrils and unaggregated peptides of beta-amyloid (Abeta). Abeta fibrils induce axonal and dendritic swellings indicative of impaired transport. In contrast, Abeta peptides induce a necrotic phenotype in both neurons and non-neuronal cells. We tested several popular hypotheses by which aggregated Abeta could disrupt transport. Using fluorescent polystyrene beads, we developed experimental models of physical blockage and localized release of reactive oxygen species (ROS) that reliably induce swellings. Like the beads, Abeta fibrils localize in close proximity to swellings; however, fibril internalization is not required for disrupting transport. ROS and membrane permeability are also unlikely to be responsible for fibril-mediated toxicity. Collectively, our results indicate that multiple initiating factors converge upon pathways of defective transport.
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Affiliation(s)
- Sameer B Shah
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
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31
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Achim CL, Adame A, Dumaop W, Everall IP, Masliah E. Increased accumulation of intraneuronal amyloid beta in HIV-infected patients. J Neuroimmune Pharmacol 2009; 4:190-9. [PMID: 19288297 PMCID: PMC3055557 DOI: 10.1007/s11481-009-9152-8] [Citation(s) in RCA: 157] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 02/25/2009] [Indexed: 01/10/2023]
Abstract
In recent years, human immunodeficiency virus (HIV)-infected patients under highly active anti-retroviral therapy (HAART) regimens have shown a markedly improved general clinical status; however, the prevalence of mild cognitive disorders has increased. We propose that increased longevity with HIV-mediated chronic inflammation combined with the secondary effects of HAART may increase the risk of early brain aging as shown by intraneuronal accumulation of abnormal protein aggregates like amyloid beta (Abeta), which might participate in worsening the neurodegenerative process and cognitive impairment in older patients with HIV. For this purpose, levels and distribution of Abeta immunoreactivity were analyzed in the frontal cortex of 43 patients with HIV (ages 38-60) and HIV- age-matched controls. Subcellular localization of the Abeta-immunoreactive material was analyzed by double labeling and confocal microscopy and by immunono-electron microscopy (EM). Compared to HIV- cases, in HIV+ cases, there was abundant intracellular Abeta immunostaining in pyramidal neurons and along axonal tracts. Cases with HIV encephalitis (HIVE) had higher levels of intraneuronal Abeta immunoreactivity compared to HIV+ cases with no HIVE. Moreover, levels of intracellular Abeta correlated with age in the group with HIVE. Double-labeling analysis showed that the Abeta-immunoreactive granules in the neurons co-localized with lysosomal markers such as cathepsin-D and LC3. Ultrastructural analysis by immuno-EM has confirmed that in these cases, intracellular Abeta was often found in structures displaying morphology similar to autophagosomes. These findings suggest that long-term survival with HIV might interfere with clearance of proteins such as Abeta and worsen neuronal damage and cognitive impairment in this population.
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Affiliation(s)
- Cristian L. Achim
- Department of Psychiatry, University of California, San Diego, CA, USA. Department of Pathology, University of California, San Diego, CA, USA
| | - Anthony Adame
- Department of Pathology, University of California, San Diego, CA, USA. Department of Neurosciences, University of California, 9500 Gilman Dr., La Jolla, San Diego, CA 92093-0624, USA
| | - Wilmar Dumaop
- Department of Pathology, University of California, San Diego, CA, USA
| | - Ian P. Everall
- Department of Psychiatry, University of California, San Diego, CA, USA
| | - Eliezer Masliah
- Department of Pathology, University of California, San Diego, CA, USA. Department of Neurosciences, University of California, 9500 Gilman Dr., La Jolla, San Diego, CA 92093-0624, USA
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Spencer B, Marr RA, Rockenstein E, Crews L, Adame A, Potkar R, Patrick C, Gage FH, Verma IM, Masliah E. Long-term neprilysin gene transfer is associated with reduced levels of intracellular Abeta and behavioral improvement in APP transgenic mice. BMC Neurosci 2008; 9:109. [PMID: 19014502 PMCID: PMC2596170 DOI: 10.1186/1471-2202-9-109] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 11/12/2008] [Indexed: 01/24/2023] Open
Abstract
Background Proteolytic degradation has emerged as a key pathway involved in controlling levels of the Alzheimer's disease (AD)-associated amyloid-β (Aβ) peptide in the brain. The endopeptidase, neprilysin, has been implicated as a major Aβ degrading enzyme in mice and humans. Previous short and intermediate term studies have shown the potential therapeutic application of neprilysin by delivering this enzyme into the brain of APP transgenic mice using gene transfer with viral vectors. However the effects of long-term neprilysin gene transfer on other aspects of Aβ associated pathology have not been explored yet in APP transgenic mice. Results We show that the sustained expression of neprilysin for up to 6 months lowered not only the amyloid plaque load but also reduced the levels of intracellular Aβ immunoreactivity. This was associated with improved behavioral performance in the water maze and ameliorated the dendritic and synaptic pathology in the APP transgenic mice. Conclusion These data support the possibility that long-term neprilysin gene therapy improves behavioral and neurodegenerative pathology by reducing intracellular Aβ.
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Affiliation(s)
- Brian Spencer
- Department of Neurosciences, University of California San Diego, La Jolla, California 92093, USA.
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Sakono M, Zako T, Ueda H, Yohda M, Maeda M. Formation of highly toxic soluble amyloid beta oligomers by the molecular chaperone prefoldin. FEBS J 2008; 275:5982-93. [DOI: 10.1111/j.1742-4658.2008.06727.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Alexander JJ, Anderson AJ, Barnum SR, Stevens B, Tenner AJ. The complement cascade: Yin-Yang in neuroinflammation--neuro-protection and -degeneration. J Neurochem 2008; 107:1169-87. [PMID: 18786171 DOI: 10.1111/j.1471-4159.2008.05668.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The complement cascade has long been recognized to play a key role in inflammatory and degenerative diseases. It is a 'double edged' sword as it is necessary to maintain health, yet can have adverse effects when unregulated, often exacerbating disease. The contrasting effects of complement, depending on whether in a setting of health or disease, is the price paid to achieve flexibility in scope and degree of a protective response for the host from infection and injury. Loss or even decreased efficiency of critical regulatory control mechanisms can result in aggravated inflammation and destruction of self-tissue. The role of the complement cascade is poorly understood in the nervous system and neurological disorders. Novel studies have demonstrated that the expression of complement proteins in brain varies in different cell types and the effects of complement activation in various disease settings appear to differ. Understanding the functioning of this cascade is essential, as it has therapeutic implications. In this review, we will attempt to provide insight into how this complex cascade functions and to identify potential strategic targets for therapeutic intervention in chronic diseases as well as acute injury in the CNS.
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Abstract
Universal features of the peptide aggregation process suggest a common mechanism, with a first-order phase transition in aqueous solutions of the peptides being the driving force. Small system sizes strongly affect the stability of the minor phase in the two-phase region. We show manifestations of this effect in aqueous solutions of fragments of the islet amyloid polypeptide, using computer simulation methods and invoking various approaches in characterizing clustering and aggregate formation. These systems with peptide concentrations deeply inside the immiscibility region show two distinct stable states, which interchange with time: one state contains a peptide aggregate; and the other state has an aggregate that is noticeably dissolved. The first state is relevant for macroscopic systems, whereas the second one is artificial. At a fixed concentration, the occurrence probability of the aggregate state vanishes upon decreasing the system size, thus indicating the necessity to apply a finite size-scaling for meaningful studies of peptide aggregation by simulations. The effect observed may be one of the factors responsible for the difference between intracellular and extracellular aggregation and fibrillization of polypeptides. The finite size of biological cells or their compartments may be playing a decisive role in hampering intracellular aggregation of highly insoluble amyloidogenic proteins, whereas aggregation is unavoidable in the extracellular space at the same peptide concentration.
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36
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Cuello AC, Canneva F. Impact of intracellular beta-amyloid in transgenic animals and cell models. NEURODEGENER DIS 2008; 5:146-8. [PMID: 18322374 DOI: 10.1159/000113686] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The present commentary based on cell and animal models of intracellular beta-amyloid (iAbeta) expression indicates that low levels of microscopically undetectable iAbeta could have a physiological role in the modulation of the cyclic AMP response element (CRE)-dependent gene expression and, as a consequence, a positive influence on synaptic plasticity (the 'good' Abeta?). On the other hand, high levels of iAbeta resembling the pathological and microscopically visible accumulation of this amyloid peptide, akin to that observed in Down syndrome and Alzheimer's disease, disrupt CRE-regulated gene expression, therefore compromising the protein synthesis-dependent component of long-term potentiation (the 'bad' Abeta?). Moreover, intracellular pathology would be independent and additive to the toxic effects of the extracellular Abeta burden.
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Affiliation(s)
- A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Que., Canada.
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Brock B, Basha MR, DiPalma K, Anderson A, Harry GJ, Rice DC, Maloney B, Lahiri DK, Zawia NH. Co-localization and distribution of cerebral APP and SP1 and its relationship to amyloidogenesis. J Alzheimers Dis 2008; 13:71-80. [PMID: 18334759 PMCID: PMC5862394 DOI: 10.3233/jad-2008-13108] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Alzheimer's disease is characterized by amyloid-beta peptide (Abeta)-loaded plaques in the brain. Abeta is a cleavage fragment of amyloid-beta protein precursor (APP) and over production of APP may lead to amyloidogenesis. The regulatory region of the APP gene contains consensus sites recognized by the transcription factor, specificity protein 1 (SP1), which has been shown to be required for the regulation of APP and Abeta. To understand the role of SP1 in APP biogenesis, herein we have characterized the relative distribution and localization of SP1, APP, and Abeta in various brain regions of rodent and primate models using immunohistochemistry. We observed that overall distribution and cellular localization of SP1, APP, and Abeta are similar and neuronal in origin. Their distribution is abundant in various layers of neocortex, but restricted to the Purkinje cell layer of the cerebellum, and the pyramidal cell layer of hippocampus. These findings suggest that overproduction of Abeta in vivo may be associated with transcriptional pathways involving SP1 and the APP gene.
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Affiliation(s)
- Brian Brock
- Neurotoxicology and Epigenomics Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881
| | - Md. Riyaz Basha
- Neurotoxicology and Epigenomics Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881
| | - Katie DiPalma
- Neurotoxicology and Epigenomics Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881
| | - Amy Anderson
- Neurotoxicology and Epigenomics Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881
| | - G. Jean Harry
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709
| | - Deborah C. Rice
- Maine Department of Health and Human Services, 11 State House Station, Augusta, ME 04333
| | - Bryan. Maloney
- Laboratory for Molecular Neurogenetics, Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Debomoy K. Lahiri
- Laboratory for Molecular Neurogenetics, Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Nasser H. Zawia
- Neurotoxicology and Epigenomics Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881
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Li XQ, Zhang SM, Yang HJ, Zhang ZH. Observation of amyloid precursor protein cleavage and A beta generation in living cells by using multiphoton laser scanning microscopy. Neurosci Bull 2008; 23:256-62. [PMID: 17952133 DOI: 10.1007/s12264-007-0038-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
OBJECTIVE To investigate the proteolytic mechanism of amyloid precursor protein (APP) and to explore amyloid-beta (A beta) generation in living neurons. METHODS DNA fragments were amplified by PCR or synthesized. The four fragments, CFP, 54bp, YFP and C99 were ligated into pcDNA3.0 vector to construct the recombinant plasmids pcDNA3.0-CFP-54bp-YFP and pcDNA3.0-CFP-54bp-YFP-C99. The SH-SY5Y cells were transiently transfected with pcDNA3.0-CFP-54bp-YFP or pcDNA3.0-CFP-54bp-YFP-C99. The expression of fusion gene was examined under a multiphoton laser scanning microscope. Fluorescence resonance energy transfer (FRET) was used to measure the beta cleavage and gamma cleavage of APP. A beta generation was confirmed by immunocytochemistry and multiphoton laser scanning microscopy. Cell viability was tested by MTT assay at different time points. RESULTS (1) The double restriction endonuclease digestion and sequencing analysis confirmed the authenticity of the recombinant plasmids pcDNA3.0-CFP-54bp-YFP and pcDNA3.0-CFP-54bp-YFP-C99. (2) Blue and yellow fluorescences were detected in the transfected cells. (3) FRET occurred in pcDNA3.0-CFP-54bp-YFP-transfected cells but not in pcDNA3.0-CFP-54bp-YFP-C99-transfected cells. (4) A beta was produced in the pcDNA3.0-CFP-54bp-YFP-C99 transfected cells. (5) A beta-deposition was widespread in the cell. (6) Cell viability decreased along with the intracellular A beta deposition. CONCLUSION C99 is important for the APP beta cleavage. A beta may be generated and deposited in cells at the early stage of Alzheimeros disease. Intracellular A beta accumulation brings deleterious effects on cells.
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Affiliation(s)
- Xiao-Qing Li
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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Li X, Xue Z, Zhang S. Construction of recombinant plasmid harboring APP717 mutation and preliminary study of APP proteolysis. ACTA ACUST UNITED AC 2007; 27:487-90. [PMID: 18060616 DOI: 10.1007/s11596-007-0502-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Indexed: 11/26/2022]
Abstract
In order to investigate the pathogenesis of Alzheimer disease (AD) and study the enzymatic progress of amyloid precursor protein (APP), the fluorescent eukaryotic expression plasmid of C99 was constructed containing APP717 mutation. The fragment encoding the last 99-aa of APP (which was named C99 containing APP717 mutation), together with the fragment encoding yellow fluorescence protein (which was named YFP) were amplified by PCR. The two fragments (YFP and C99) were inserted into the vector pcDNA3.0. The recombinant plasmid pcDNA3.0-YFP-C99 was accomplished and its authenticity was confirmed by enzyme digestion and sequencing. Then SH-SY5Y cells were transiently transfected with the recombinant plasmid pcDNA3.0-YFP-C99. The expression of the fusion gene was detected by laser confocalmicroscopy. Amyloid-beta (Abeta) was detected by both microscopy and immunochemistry. The authenticity of the construct was confirmed by the endonuclease digestion and DNA sequencing. The YFP fluorescence could be seen and proved the expression of fusion gene. Abeta labeled by YFP was detected by confocalmicroscopy and confirmed by immunocytochemistry. It was found that Abeta accumulated and deposited in the intracytoplasm, membrane and outside of the cell. Furthermore, Abeta accumulated mainly within the cell ahead of the deposition in the cell space and the cell shape was rough. It was suggested that Abeta could be generated within the cells. Abeta accumulated in the cell at the early stage before the deposition outside of the cells. Intracellular Abeta accumulation induced the secondary damage to the cells and caused the cell shape rough. Taken together, the recombinant plasmid, pcDNA3.0-YFP-C99 could be a useful tool to further study the cleavage mechanism of APP and to explore the pathogenesis of AD.
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Affiliation(s)
- Xiaoqing Li
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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40
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Saavedra L, Mohamed A, Ma V, Kar S, de Chaves EP. Internalization of beta-amyloid peptide by primary neurons in the absence of apolipoprotein E. J Biol Chem 2007; 282:35722-32. [PMID: 17911110 DOI: 10.1074/jbc.m701823200] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Extracellular accumulation of beta-amyloid peptide (Abeta) has been linked to the development of Alzheimer disease. The importance of intraneuronal Abeta has been recognized more recently. Although considerable evidence indicates that extracellular Abeta contributes to the intracellular pool of Abeta, the mechanisms involved in Abeta uptake by neurons are poorly understood. We examined the molecular mechanisms involved in Abeta-(1-42) internalization by primary neurons in the absence of apolipoprotein E. We demonstrated that Abeta-(1-42) is more efficiently internalized by axons than by cell bodies of sympathetic neurons, suggesting that Abeta-(1-42) uptake might be mediated by proteins enriched in the axons. Although the acetylcholine receptor alpha7nAChR, previously suggested to be involved in Abeta internalization, is enriched in axons, our results indicate that it does not mediate Abeta-(1-42) internalization. Moreover, receptors of the low density lipoprotein receptor family are not essential for Abeta-(1-42) uptake in the absence of apolipoprotein E because receptor-associated protein had no effect on Abeta uptake. By expressing the inactive dynamin mutant dynK44A and the clathrin hub we found that Abeta-(1-42) internalization is independent of clathrin but dependent on dynamin, which suggests an endocytic pathway involving caveolae/lipid rafts. Confocal microscopy studies showing that Abeta did not co-localize with the early endosome marker EEA1 further support a clathrin-independent mechanism. The lack of co-localization of Abeta with caveolin in intracellular vesicles and the normal uptake of Abeta by neurons that do not express caveolin indicate that Abeta does not require caveolin either. Instead partial co-localization of Abeta-(1-42) with cholera toxin subunit B and sensitivity to reduction of cellular cholesterol and sphingolipid levels suggest a caveolae-independent, raft-mediated mechanism. Understanding the molecular events involved in neuronal Abeta internalization might identify potential therapeutic targets for Alzheimer disease.
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Affiliation(s)
- Lucila Saavedra
- Department of Pharmacology, University of Alberta, Edmonton, Canada
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41
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Na CH, Jeon SH, Zhang G, Olson GL, Chae CB. Inhibition of amyloid ?-peptide production by blockage of ?-secretase cleavage site of amyloid precursor protein. J Neurochem 2007; 101:1583-95. [PMID: 17542811 DOI: 10.1111/j.1471-4159.2006.04441.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Amyloid beta-peptide (Abeta) is implicated as the major causative agent in Alzheimer's disease (AD). Abeta is produced by the processing of the amyloid precursor protein (APP) by BACE1 (beta-secretase) and gamma-secretase. Many inhibitors have been developed for the secretases. However, the inhibitors will interfere with the processing of not only APP but also of other secretase substrates. In this study, we describe the development of inhibitors that prevent production of Abeta by specific binding to the beta-cleavage site of APP. We used the hydropathic complementarity (HC) approach for the design of short peptide inhibitors. Some of the HC peptides were bound to the substrate peptide (Sub W) corresponding to the beta-cleavage site of APP and blocked its cleavage by recombinant human BACE1 (rhBACE1) in vitro. In addition, HC peptides specifically inhibited the cleavage of Sub W, and not affecting other BACE1 substrates. Chemical modification allowed an HC peptide (CIQIHF) to inhibit the processing of APP as well as the production of Abeta in the treated cells. Such novel APP-specific inhibitors will provide opportunity for the development of drugs that can be used for the prevention and treatment of AD with minimal side effects.
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Affiliation(s)
- Chan Hyun Na
- Department of Life Science, Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Korea
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Hu Z, Zeng L, Huang Z, Zhang J, Li T. The Study of Golgi Apparatus in Alzheimer’s Disease. Neurochem Res 2007; 32:1265-77. [PMID: 17401657 DOI: 10.1007/s11064-007-9302-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Accepted: 01/30/2007] [Indexed: 10/23/2022]
Abstract
Alzheimer's disease is an irreversible, progressive neurodegenerative disorder leading invariably to death, usually within 7-10 years after diagnosis and is the leading cause of dementia in the elderly. Not only is Alzheimer's disease a tragic disease in which people suffer from neurodegeneration in the years to come, it also becomes an incredible burden on the public health system. However, there is currently no effective treatment to halt the progression or prevent the onset of Alzheimer's disease. This is partly due to the fact that the complex pathophysiology of Alzheimer's disease is not yet completely understood. Recently, Golgi apparatus is found to play an important role in Alzheimer's disease. In this review, we discuss the changes of Golgi apparatus during clinical progression and pathological development of Alzheimer's disease. First, changes of Golgi apparatus size in Alzheimer's disease are summarized. We then address the role of Golgi apparatus in the neuropathology of Alzheimer's disease. Finally, the role of Golgi apparatus in the pathogenesis of Alzheimer's disease is discussed. Understanding the contribution of Golgi apparatus dysfunction to Alzheimer's disease and its pathophysiological basis will significantly impact our ability to develop more effective therapies for Alzheimer's disease.
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Affiliation(s)
- Zhiping Hu
- Department of Neurology, Second Xiangya Hospital, Central South University, Changsha, China
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Chen Y, Bodles AM, McPhie DL, Neve RL, Mrak RE, Griffin WST. APP-BP1 inhibits Abeta42 levels by interacting with Presenilin-1. Mol Neurodegener 2007; 2:3. [PMID: 17286867 PMCID: PMC1802080 DOI: 10.1186/1750-1326-2-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2006] [Accepted: 02/07/2007] [Indexed: 11/10/2022] Open
Abstract
Background The β-amyloid precursor protein (APP) is sequentially cleaved by the β- and then γ-secretase to generate the amyloid β-peptides Aβ40 and Aβ42. Increased Aβ42/Aβ40 ratios trigger amyloid plaque formations in Alzheimer's disease (AD). APP binds to APP-BP1, but the biological consequence is not well understood. Results We report that when the endogenous APP-BP1 was suppressed by small interfering RNAs (siRNAs), cell-associated Aβ42 was dramatically increased in APP695 expressing primary neurons. The accumulation of Aβ42 was accompanied by significant increases in APP and APP-CTF in APP-BP1 siRNA expressing neurons. In contrast, APP-BP1 overexpression in primary neurons significantly decreased the levels of Aβ and endogenous APP but not APLPs. We also investigated the potential mechanism of APP-BP1-mediated APP processing. APP-BP1 co-precipitated with Presenilin-1 (PS1) in native rat brain extracts, co-migrated with the γ-secretase components in brain membrane extracts in glycerol gradient centrifugation, and colocalized in primary neurons. Further, the endogenous PS1-CTF was significantly downregulated by APP-BP1 expression. Conclusion Our data suggest that APP-BP1 may inhibit Aβ42 production by interacting with PS1 under physiological conditions.
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Affiliation(s)
- Yuzhi Chen
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Angela M Bodles
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Donna L McPhie
- Department of Psychiatry, McLean Hospital and Harvard Medical School, Belmont, MA 02478, USA
| | - Rachael L Neve
- Department of Psychiatry, McLean Hospital and Harvard Medical School, Belmont, MA 02478, USA
| | - Robert E Mrak
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - W Sue T Griffin
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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Oakley H, Cole SL, Logan S, Maus E, Shao P, Craft J, Guillozet-Bongaarts A, Ohno M, Disterhoft J, Van Eldik L, Berry R, Vassar R. Intraneuronal beta-amyloid aggregates, neurodegeneration, and neuron loss in transgenic mice with five familial Alzheimer's disease mutations: potential factors in amyloid plaque formation. J Neurosci 2006; 26:10129-40. [PMID: 17021169 PMCID: PMC6674618 DOI: 10.1523/jneurosci.1202-06.2006] [Citation(s) in RCA: 2367] [Impact Index Per Article: 131.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mutations in the genes for amyloid precursor protein (APP) and presenilins (PS1, PS2) increase production of beta-amyloid 42 (Abeta42) and cause familial Alzheimer's disease (FAD). Transgenic mice that express FAD mutant APP and PS1 overproduce Abeta42 and exhibit amyloid plaque pathology similar to that found in AD, but most transgenic models develop plaques slowly. To accelerate plaque development and investigate the effects of very high cerebral Abeta42 levels, we generated APP/PS1 double transgenic mice that coexpress five FAD mutations (5XFAD mice) and additively increase Abeta42 production. 5XFAD mice generate Abeta42 almost exclusively and rapidly accumulate massive cerebral Abeta42 levels. Amyloid deposition (and gliosis) begins at 2 months and reaches a very large burden, especially in subiculum and deep cortical layers. Intraneuronal Abeta42 accumulates in 5XFAD brain starting at 1.5 months of age (before plaques form), is aggregated (as determined by thioflavin S staining), and occurs within neuron soma and neurites. Some amyloid deposits originate within morphologically abnormal neuron soma that contain intraneuronal Abeta. Synaptic markers synaptophysin, syntaxin, and postsynaptic density-95 decrease with age in 5XFAD brain, and large pyramidal neurons in cortical layer 5 and subiculum are lost. In addition, levels of the activation subunit of cyclin-dependent kinase 5, p25, are elevated significantly at 9 months in 5XFAD brain, although an upward trend is observed by 3 months of age, before significant neurodegeneration or neuron loss. Finally, 5XFAD mice have impaired memory in the Y-maze. Thus, 5XFAD mice rapidly recapitulate major features of AD amyloid pathology and may be useful models of intraneuronal Abeta42-induced neurodegeneration and amyloid plaque formation.
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Affiliation(s)
| | | | | | - Erika Maus
- Departments of Cell and Molecular Biology and
| | - Pei Shao
- Departments of Cell and Molecular Biology and
| | | | | | - Masuo Ohno
- Physiology, The Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - John Disterhoft
- Physiology, The Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
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Mazur-Kolecka B, Dickson D, Frackowiak J. Induction of vascular amyloidosis-β by oxidative stress depends on APOE genotype. Neurobiol Aging 2006; 27:804-14. [PMID: 15993987 DOI: 10.1016/j.neurobiolaging.2005.04.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2004] [Revised: 04/13/2005] [Accepted: 04/26/2005] [Indexed: 11/19/2022]
Abstract
The reduced antioxidant defense in apolipoprotein E epsilon4/epsilon4 carriers may contribute to beta-amyloidosis. Previously we found that Fe(2+)-induced oxidative stress caused greater protein oxidation in epsilon4/epsilon4 than in epsilon3/epsilon3 human brain vascular smooth muscle cells. Moreover, Fe(2+) induced lysosomal accumulation of endogenous Abeta and APOE in cultured cells, and Abeta deposition in vascular tunica media in organotypic cultures of brain vessels. Here we demonstrated that Fe(2+) enhanced an uptake of exogenous Abeta 1-40 and its deposition together with APOE in lysosomes in myocytes. Abeta deposits were associated with lipid-peroxidation and protein ubiquitination, and were more abundant and stable in epsilon4/epsilon4 than in epsilon3/epsilon3 cells. In organotypic cultures of brain vessels Fe(2+) induced deposition of non-fibrillar and fibrillar Abeta 1-40 in vascular tunica media. We hypothesize that locally increased concentrations of iron induce accumulation of exogenous and endogenous Abeta in SMCs, triggering beta-amyloid angiopathy. The greater susceptibility of epsilon4 carriers to Fe(2+) ions may result in an increased risk of beta-amyloidosis.
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Affiliation(s)
- Bozena Mazur-Kolecka
- New York State Institute for Basic Research in Developmental Disabilities, Department of Developmental Neurobiology, 1050 Forest Hill Road, Staten Island, NY 10314, USA.
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Gouras GK, Almeida CG, Takahashi RH. Intraneuronal Abeta accumulation and origin of plaques in Alzheimer's disease. Neurobiol Aging 2006; 26:1235-44. [PMID: 16023263 DOI: 10.1016/j.neurobiolaging.2005.05.022] [Citation(s) in RCA: 230] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Revised: 05/25/2005] [Accepted: 05/27/2005] [Indexed: 10/25/2022]
Abstract
Plaques are a defining neuropathological hallmark of Alzheimer's disease (AD) and the major constituent of plaques, the beta-amyloid peptide (Abeta), is considered to play an important role in the pathophysiology of AD. But the biological origin of Abeta plaques and the mechanism whereby Abeta is involved in pathogenesis have been unknown. Abeta plaques were thought to form from the gradual accumulation and aggregation of secreted Abeta in the extracellular space. More recently, the accumulation of Abeta has been demonstrated to occur within neurons with AD pathogenesis. Moreover, intraneuronal Abeta accumulation has been reported to be critical in the synaptic dysfunction, cognitive dysfunction and the formation of plaques in AD. Here we provide a historical overview on the origin of plaques and a discussion on potential biological and therapeutic implications of intraneuronal Abeta accumulation for AD.
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Affiliation(s)
- Gunnar K Gouras
- Laboratory of Alzheimer's disease Neurobiology, Department of Neurology & Neuroscience, Weill Medical College of Cornell University, 525 East 68th Street, New York, NY 10021, USA.
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Zhou J, Fonseca MI, Kayed R, Hernandez I, Webster SD, Yazan O, Cribbs DH, Glabe CG, Tenner AJ. Novel Abeta peptide immunogens modulate plaque pathology and inflammation in a murine model of Alzheimer's disease. J Neuroinflammation 2005; 2:28. [PMID: 16332263 PMCID: PMC1326209 DOI: 10.1186/1742-2094-2-28] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Accepted: 12/07/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Alzheimer's disease, a common dementia of the elder, is characterized by accumulation of protein amyloid deposits in the brain. Immunization to prevent this accumulation has been proposed as a therapeutic possibility, although adverse inflammatory reactions in human trials indicate the need for novel vaccination strategies. METHOD Here vaccination with novel amyloid peptide immunogens was assessed in a transgenic mouse model displaying age-related accumulation of fibrillar plaques. RESULTS Immunization with any conformation of the amyloid peptide initiated at 12 months of age (at which time fibrillar amyloid has just begun to accumulate) showed significant decrease in total and fibrillar amyloid deposits and in glial reactivity relative to control transgenic animals. In contrast, there was no significant decrease in amyloid deposition or glial activation in mice in which vaccination was initiated at 16 months of age, despite the presence of similar levels anti-Abeta antibodies in young and old animals vaccinated with a given immunogen. Interestingly, immunization with an oligomeric conformation of Abeta was equally as effective as other amyloid peptides at reducing plaque accumulation. However, the antibodies generated by immunization with the oligomeric conformation of Abeta have more limited epitope reactivity than those generated by fAbeta, and the microglial response was significantly less robust. CONCLUSION These results suggest that a more specific immunogen such as oligomeric Abeta can be designed that achieves the goal of depleting amyloid while reducing potential detrimental inflammatory reactions. In addition, the data show that active immunization of older Tg2576 mice with any amyloid conformation is not as efficient at reducing amyloid accumulation and related pathology as immunization of younger mice, and that serum anti-amyloid antibody levels are not quantitatively related to reduced amyloid-associated pathology.
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Affiliation(s)
- Jun Zhou
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Maria I Fonseca
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Rakez Kayed
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Irma Hernandez
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | | | - Ozkan Yazan
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - David H Cribbs
- Department of Neurology, University of California, Irvine, College of Medicine, Irvine, CA 92697, USA
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697, USA
| | - Charles G Glabe
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697, USA
| | - Andrea J Tenner
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697, USA
- Center for Immunology, University of California, Irvine, CA 92697, USA
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Reddy PH, McWeeney S. Mapping cellular transcriptosomes in autopsied Alzheimer's disease subjects and relevant animal models. Neurobiol Aging 2005; 27:1060-77. [PMID: 16157420 DOI: 10.1016/j.neurobiolaging.2005.04.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Revised: 03/21/2005] [Accepted: 04/02/2005] [Indexed: 10/25/2022]
Abstract
Alzheimer's disease (AD) is a late-onset and progressive neurodegenerative disorder characterized clinically by memory loss, impairment of other cognitive functions, and changes in behavior and personality. The overall aim of this review is to summarize recent advances in studies of AD progression and the use of animal models in gene expression studies of AD progression. Genetic causes of AD are known only for early-onset AD patients. For a majority of late-onset AD patients, causal factors are still unknown. Currently, there are no early detectable biomarkers for late-onset AD, and there is a lack of understanding of AD pathophysiology, particularly at the early stages of disease progression, before pathology develops. Human histopathological and biochemical studies provide valuable information regarding the last stages of AD pathogenesis. However, to understand early cellular changes in AD progression before symptoms develop, animal models are still our only alternative. Several research groups have created genetically engineered animal models, particularly models of the mouse, rat, fly, and worm, which have allowed us to better, understand the initiating events of AD progression. Recently, state-of-the-art methods have helped elucidate gene expression changes in affected and unaffected tissues from postmortem AD brains and from animal models developed for AD studies. These methods allow the investigation of mRNA-based transcriptosomal profiles of brain specimens from AD humans and transgenic animals. The major finding from these studies is that AD progression and pathogenesis involve multiple cellular pathways, which suggests that AD is a complex and heterogeneous disease.
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Affiliation(s)
- P Hemachandra Reddy
- Neurogenetics Laboratory, Neurological Sciences Institute, Oregon Health and Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA.
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Seripa D, Matera MG, Dal Forno G, Gravina C, Masullo C, Daniele A, Binetti G, Bonvicini C, Squitti R, Palermo MT, Davis DG, Antuono P, Wekstein DR, Dobrina A, Gennarelli M, Fazio VM. Genotypes and haplotypes in the IL-1 gene cluster: analysis of two genetically and diagnostically distinct groups of Alzheimer patients. Neurobiol Aging 2005; 26:455-64. [PMID: 15653174 DOI: 10.1016/j.neurobiolaging.2004.04.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2003] [Revised: 03/24/2004] [Accepted: 04/12/2004] [Indexed: 11/30/2022]
Abstract
Increased risk of Alzheimer's disease (AD) has been associated with polymorphisms in the IL-1 gene cluster, and in particular with the IL-1alpha-889 T/T genotype. However, this association is still unclear, and needs further investigation. In order to clarify the role of these polymorphisms in the complex pathogenesis of AD we examined genotype and haplotype frequencies of the two C-to-T SNPs at position -889 and -551 in the IL-1alpha and IL-1beta genes, respectively, and of the 86 bp VNTR intron-2 polymorphisms in the IL-1Ra gene. The analysis was performed in two genetically and diagnostically distinct groups of sporadic AD from Italy and the USA. In the Italian group a significant association between the IL-1alpha-889 T/T genotype and AD (OR=3.022, 95% CI: 1.001-9.119) was found, whereas no difference was found in the group from the USA. Results were also compared with previously published studies that analyzed the same IL-1 polymorphisms in AD. In both groups, the analysis of the estimated haplotypes shows that AD patients and controls who carry the IL-1beta-511 C allele, were also more frequently carriers of the IL-1Ra 1 allele (haplotypes -C-1). The total frequency of the two -C-1 haplotypes (C-C-1 plus T-C-1) was about one half of the total frequency of the eight estimated haplotypes. This was confirmed by significant linkage disequilibrium between these two loci in both the Italian and USA groups. In the Italian group a weak association of the T-C-2 haplotype with the disease (OR=1.648, 95% CI: 1.519-1.788) was also found, whereas in the USA group no difference was found. Although ours and other published data on different samples of Caucasian and non-Caucasian AD show a great heterogeneity in the frequencies of the IL-1alpha-889, the IL-1beta-511 and the IL-1Ra VNTR gene polymorphisms, we confirm the role of the IL-1alpha-889 T/T genotype as a risk factor for sporadic AD, and show the presence of an allelic association between IL-1beta C and IL-1Ra 1 alleles in both the Italian and the USA groups, confirmed by the presence of significant levels of linkage disequilibrium between these two loci.
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Affiliation(s)
- Davide Seripa
- Laboratory of Gene Therapy, I.R.C.C.S. Casa Sollievo della Sofferenza, Padre Pio da Pietrelcina Foundation, San Giovanni Rotondo, FG, Italy.
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Abstract
The central pathological cause of Alzheimer disease (AD) is hypothesized to be an excess of beta-amyloid (Abeta) which accumulates into toxic fibrillar deposits within extracellular areas of the brain. These deposits disrupt neural and synaptic function and ultimately lead to neuronal degeneration and dementia. In addition to the pathological roles attributed to Abeta, evidence from our laboratory would suggest that Abeta serves a physiological role in the modulation of CRE-directed gene expression. This commentary also highlights some of the pathological consequences of the accumulation of intracellular Abeta. Finally it discusses the impact of cortical Abeta burden on transmitter-specific synaptic numbers as well as the generation of dystrophic neurites. The fundamental thesis of my proposal is that the Abeta pathology seen in AD is a continuous process from an initial abnormal Abeta intracellular accumulation to the well-established extracellular Abeta aggregation, culminating in the formation of amyloid plaques and dystrophic neurites.
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Affiliation(s)
- A Claudio Cuello
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Canada.
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