1001
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Abstract
Aggregates of dysfunctional proteins and peptides in or between brain neurons are key neuropathological features of dementia and are believed to directly cause or substantially contribute to the development of these diseases. Fundamental parts of the mechanisms underlying the dysregulation of proteins in Alzheimer's disease, frontotemporal dementia, prion diseases and other dementing disorders are now well characterized, mainly due to the discovery of genes causing dominantly inherited disease forms (Table 1). As of today, no efficient pharmacotherapies are available, but new insights into the underlying molecular mechanisms are providing strategies to prevent or even cure these devastating disorders.
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Affiliation(s)
- Martin Ingelsson
- Harvard Medical School, Massachusetts General Hospital, Charlestown 02129, USA
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1002
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Koistinaho M, Ort M, Cimadevilla JM, Vondrous R, Cordell B, Koistinaho J, Bures J, Higgins LS. Specific spatial learning deficits become severe with age in beta -amyloid precursor protein transgenic mice that harbor diffuse beta -amyloid deposits but do not form plaques. Proc Natl Acad Sci U S A 2001; 98:14675-80. [PMID: 11724968 PMCID: PMC64740 DOI: 10.1073/pnas.261562998] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2001] [Indexed: 11/18/2022] Open
Abstract
Memory impairment progressing to dementia is the main clinical symptom of Alzheimer's disease (AD). AD is characterized histologically by the presence of beta-amyloid (Abeta) plaques and neurofibrillary tangles in specific brain regions. Although Abeta derived from the Abeta precursor protein (beta-APP) is believed to play a central etiological role in AD, it is not clear whether soluble and/or fibrillar forms are responsible for the memory deficit. We have generated and previously described mice expressing human wild-type beta-APP(751) isoform in neurons. These transgenic mice recapitulate early histopathological features of AD and form Abeta deposits but no plaques. Here we describe a specific and progressive learning and memory impairment in these animals. In the Morris water maze, a spatial memory task sensitive to hippocampal damage, one pedigree already showed significant differences in acquisition in 3-month-old mice that increased in severity with age and were expressed clearly in 6-month- and 2-year-old animals. The second transgenic pedigree displayed a milder impairment with a later age of onset. Performance deficits significantly decreased during the 6 days of training in young but not in aged transgenic animals. Both pedigrees of the transgenic mice differed from wild-type mice by less expressed increase of escape latencies after the platform position had been changed in the reversal experiment and by failure to prefer the goal quadrant in probe trials. Both pedigrees performed at wild-type level in a number of other tests (open field exploration and passive and active place avoidance). The results suggest that plaque formation is not a necessary condition for the neuronal beta-APP(751) transgene-induced memory impairment, which may be caused by beta-APP overexpression, isoform misexpression, or elevated soluble Abeta.
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Affiliation(s)
- M Koistinaho
- Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 Prague 4-Krc, Czech Republic
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1003
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Blasko I, Apochal A, Boeck G, Hartmann T, Grubeck-Loebenstein B, Ransmayr G. Ibuprofen decreases cytokine-induced amyloid beta production in neuronal cells. Neurobiol Dis 2001; 8:1094-101. [PMID: 11741404 DOI: 10.1006/nbdi.2001.0451] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Trying to decrease the production of Amyloid beta (Abeta) has been envisaged as a promising approach to prevent neurodegeneration in Alzheimer's disease (AD). A chronic inflammatory reaction with activated microglia cells and astrocytes is a constant feature of AD. The participation of the immune system in the disease process is further documented in several retrospective clinical studies showing an inverse relationship between the prevalence of AD and nonsteroidal anti-inflammatory drug (NSAID) therapy. Previously, we demonstrated that the combination of the proinflammatory cytokines TNFalpha with IFNgamma induces the production of Abeta-42 and Abeta-40 in human neuronal cells. In the present study, the neuronal cell line Sk-n-sh was incubated for 12 h with the cyclooxygenase inhibitor ibuprofen and subsequently stimulated with the cytokines TNFalpha and IFNgamma. Ibuprofen treatment decreased the secretion of total Abeta in the conditioned media of cytokine stimulated cells by 50% and prevented the accumulation of Abeta-42 and Abeta-40 in detergent soluble cell extracts. Viability of neuronal cells measured by detection of apoptosis was neither influenced by ibuprofen nor by cytokine treatment. The reduction in the production of Abeta by ibuprofen was presumably due to a decreased production of betaAPP, which in contrast to the control proteins M2 pyruvate kinase, beta-tubulin and the cytokine inducible ICAM-1 was detected at low concentration in ibuprofen treated cells. The data demonstrate a possible mechanism how ibuprofen may decrease the risk and delay the onset of AD.
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Affiliation(s)
- I Blasko
- Institute for Biomedical Aging Research, Austrian Academy of Sciences, Innsbruck, Austria
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1004
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Scorer CA. Preclinical and clinical challenges in the development of disease-modifying therapies for Alzheimer's disease. Drug Discov Today 2001; 6:1207-1219. [PMID: 11722873 DOI: 10.1016/s1359-6446(01)02042-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The neurodegenerative disease first described almost 100 years ago by Alois Alzheimer is predicted to be one of the major health problems of the 21st century. Alzheimer's disease (AD) is a progressive dementia characterized by global cognitive decline and is defined pathologically by amyloid plaques and neurofibrillary tangles. Major unmet medical need has encouraged pharmaceutical companies to invest in AD drug development. Promising novel approaches are under way, assisted by recent advances in animal models and an increased understanding of pathophysiology. However, demonstration of disease modification and identification of at-risk individuals are among the significant challenges facing those working in AD drug development.
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Affiliation(s)
- Carol A. Scorer
- Psychiatry Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park, Third Avenue, CM19 5AW tel: +44 1279 875227 fax: +44 1279 622660, Essex, UK
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1005
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Miller MM, Monjan AA, Buckholtz NS. Estrogen replacement therapy for the potential treatment or prevention of Alzheimer's disease. Ann N Y Acad Sci 2001; 949:223-34. [PMID: 11795357 DOI: 10.1111/j.1749-6632.2001.tb04025.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alzheimer's disease (AD) is an irreversible, progressive brain disorder that occurs gradually and results in memory loss, behavior and personality changes, and a decline in cognitive abilities. Although basic biological data suggest that estrogen may have neuroprotective and neuroenhancing functions, a number of studies have produced conflicting findings on the use of estrogen for maintaining cognitive function in older people. This review summarizes clinical studies that have examined the effects of estrogen in women with AD.
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Affiliation(s)
- M M Miller
- Neuroscience and Neuropsychology of Aging Program, National Institute on Aging, National Institutes of Health, Bethesda, Maryland 20892, USA
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1006
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Schwarz MJ, Chiang S, Müller N, Ackenheil M. T-helper-1 and T-helper-2 responses in psychiatric disorders. Brain Behav Immun 2001; 15:340-70. [PMID: 11782103 DOI: 10.1006/brbi.2001.0647] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The expanding field of psychoneuroimmunology has markedly increased knowledge about the interference of the central nervous system and the immune system. Immunological abnormalities in psychiatric patients have been repeatedly described in the last century. Modern concepts of immunology and the growing knowledge of psychoneuroimmunology may help in understanding the distinct immunological mechanisms in psychiatric disorders. One of these concepts regarding the adaptive immune system is the discrimination between Th1-like cell-mediated and Th2-like antibody-related immune responses. This article systematically describes alterations of Th1- or Th2-specific parameters in the major psychiatric disorders schizophrenia, major depression, and Alzheimer's disease. There are several hints of associations of these two distinct arms of immune response with subgroups of schizophrenia and major depression. The immunological research in Alzheimer's disease has already led to a preclinical model of immunotherapy. Categorization of immune parameters may also help to identify a possible immune-related pathophysiology in psychotic and affective disorders, resulting in specific treatment strategies.
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Affiliation(s)
- M J Schwarz
- Psychiatric Hospital, University of Munich, Nussbaumstr. 7, D-80336 Munich, Germany
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1007
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Vandermeeren M, Geraerts M, Pype S, Dillen L, Van Hove C, Mercken M. The functional gamma-secretase inhibitor prevents production of amyloid beta 1-34 in human and murine cell lines. Neurosci Lett 2001; 315:145-8. [PMID: 11716984 DOI: 10.1016/s0304-3940(01)02369-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The amyloid precursor protein (APP) undergoes two consecutive cleavages by different proteases, beta-secretase and gamma-secretase, leading to the release of an amyloidogenic 4 kDa fragment called amyloid beta (Abeta). Combining immunoprecipitation and mass spectrometry, we characterized soluble Abeta in cultured cell media of mouse neuroblastoma N2a cells and double hAPP/hBACE-1 transfected HEK293. The major Abeta isoforms detected were Abeta11-34, Abeta1-34, Abeta11-40 and Abeta1-40. In this study, we demonstrate that overexpression of human beta-secretase (BACE-1) in HEK293 cells resulted in predominant Abeta cleavage at position Glu(11) rather than Asp(1), as well as increased production of Abeta(x)-34, but not Abeta(x)-40. Incubation of cells with a specific gamma-secretase inhibitor suggests that cleavage of APP at Leu(34) could be mediated by gamma-secretase itself or by a gamma-secretase dependent process.
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Affiliation(s)
- M Vandermeeren
- CNS Discovery Research, Janssen Research Foundation, Janssen Pharmaceutica, B-2340 Beerse, Belgium
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1008
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Arendash GW, Gordon MN, Diamond DM, Austin LA, Hatcher JM, Jantzen P, DiCarlo G, Wilcock D, Morgan D. Behavioral assessment of Alzheimer's transgenic mice following long-term Abeta vaccination: task specificity and correlations between Abeta deposition and spatial memory. DNA Cell Biol 2001; 20:737-44. [PMID: 11788052 DOI: 10.1089/10445490152717604] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Long-term vaccinations with human beta-amyloid peptide 1-42 (Abeta1-42) have recently been shown to prevent or markedly reduce Abeta deposition in the PDAPP transgenic model of Alzheimer's disease (AD). Using a similar protocol to vaccinate 7.5-month-old APP (Tg2576) and APP+PS1 transgenic mice over an 8-month period, we previously reported modest reductions in brain Abeta deposition at 16 months. In these same mice, Abeta vaccinations had no deleterious behavioral effects and, in fact, benefited the mice by providing partial protection from age-related deficits in spatial working memory in the radial arm water maze task (RAWM) at 15.5 months. By contrast, control-vaccinated transgenic mice exhibited impaired performance throughout the entire RAWM test period at 15.5 months. The present study expands on our initial report by presenting additional behavioral results following long-term Abeta vaccination, as well as correlational analyses between cognitive performance and Abeta deposition in vaccinated animals. We report that 8 months of Abeta vaccinations did not reverse an early-onset balance beam impairment in transgenic mice. Additionally, in Y-maze testing at 16 months, all mice showed comparable spontaneous alternation irrespective of genotype or vaccination status. Strong correlations were nonetheless present between RAWM performance and extent of "compact" Abeta deposition in both the hippocampus and the frontal cortex of vaccinated APP+PS1 mice. Our results suggest that the behavioral protection of long-term Abeta vaccinations is task specific, with preservation of hippocampal-associated working memory tasks most likely to occur. In view of the early short-term memory deficits exhibited by AD patients, Abeta vaccination of presymptomatic AD patients could be an effective therapeutic to protect against such cognitive impairments.
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Affiliation(s)
- G W Arendash
- The Alzheimer's Research Consortium, Department of Biology, University of South Florida, Tampa, Florida 33620, USA.
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1009
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Abstract
Recent advances in behavioral analyses of transgenic mouse models of Alzheimer's disease (AD) are discussed, and their impact on our understanding of the molecular basis of cognitive impairment in AD is considered. Studies of the relationship between memory and A Beta in transgenic mice expressing the amyloid precursor protein (APP) and its variants suggest that aging promotes the formation of soluble A Beta assemblies mediating negative effects on memory. A significant component of memory loss in APP transgenic mice is apparently caused by soluble A Beta assemblies, but whether and how much of the dementia within individuals afflicted with AD is caused by these A Beta species is unclear. Future studies in composite transgenic mice developing amyloid plaques, neurofibrillary tangles, and other AD pathology may allow for the determination of the relative contribution of A Beta and non-A Beta components to dementia.
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Affiliation(s)
- K H Ashe
- Department of Neurology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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1010
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Lambert MP, Viola KL, Chromy BA, Chang L, Morgan TE, Yu J, Venton DL, Krafft GA, Finch CE, Klein WL. Vaccination with soluble Abeta oligomers generates toxicity-neutralizing antibodies. J Neurochem 2001; 79:595-605. [PMID: 11701763 DOI: 10.1046/j.1471-4159.2001.00592.x] [Citation(s) in RCA: 252] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In recent studies of transgenic models of Alzheimer's disease (AD), it has been reported that antibodies to aged beta amyloid peptide 1-42 (Abeta(1-42)) solutions (mixtures of Abeta monomers, oligomers and amyloid fibrils) cause conspicuous reduction of amyloid plaques and neurological improvement. In some cases, however, neurological improvement has been independent of obvious plaque reduction, and it has been suggested that immunization might neutralize soluble, non-fibrillar forms of Abeta. It is now known that Abeta toxicity resides not only in fibrils, but also in soluble protofibrils and oligomers. The current study has investigated the immune response to low doses of Abeta(1-42) oligomers and the characteristics of the antibodies they induce. Rabbits that were injected with Abeta(1-42) solutions containing only monomers and oligomers produced antibodies that preferentially bound to assembled forms of Abeta in immunoblots and in physiological solutions. The antibodies have proven useful for assays that can detect inhibitors of oligomer formation, for immunofluorescence localization of cell-attached oligomers to receptor-like puncta, and for immunoblots that show the presence of SDS-stable oligomers in Alzheimer's brain tissue. The antibodies, moreover, were found to neutralize the toxicity of soluble oligomers in cell culture. Results support the hypothesis that immunizations of transgenic mice derive therapeutic benefit from the immuno-neutralization of soluble Abeta-derived toxins. Analogous immuno-neutralization of oligomers in humans may be a key in AD vaccines.
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Affiliation(s)
- M P Lambert
- Department of Neurobiology and Physiology, Northwestern University, Evanston, IL 60208, USA
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1011
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1012
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Wilcock DM, Gordon MN, Ugen KE, Gottschall PE, DiCarlo G, Dickey C, Boyett KW, Jantzen PT, Connor KE, Melachrino J, Hardy J, Morgan D. Number of Abeta inoculations in APP+PS1 transgenic mice influences antibody titers, microglial activation, and congophilic plaque levels. DNA Cell Biol 2001; 20:731-6. [PMID: 11788051 DOI: 10.1089/10445490152717596] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
There have been several reports on the use of beta-amyloid (Abeta ) vaccination in different mouse models of Alzheimer's disease (AD) and its effects on pathology and cognitive function. In this report, the histopathologic findings in the APP+PS1 doubly transgenic mouse were compared after three, five, or nine Abeta inoculations. The number of inoculations influenced the effects of vaccination on Congo red levels, microglia activation, and anti-Abeta antibody titers. After three inoculations, the antibody titer of transgenic mice was substantially lower than that found in nontransgenic animals. However, after nine inoculations, the levels were considerably higher in both genotypes and no longer distinguishable statistically. The number of inoculations influenced CD45 expression, an indicator of microglial activation. There was an initial upregulation, which was significant after five inoculations, but by nine inoculations, the extent of microglial activation was equivalent to that in mice given control vaccinations. Along with this increased CD45 expression, there was a correlative reduction in staining by Congo red, which stains compact plaques. When data from the mice from all groups were combined, there was a significant correlation between activation of microglia and Congo red levels, suggesting that microglia play a role in the clearance of compact plaque.
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Affiliation(s)
- D M Wilcock
- Alzheimer's Research Laboratory, Department of Pharmacology, University of South Florida, Tampa, Florida, USA
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1013
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Rogers J, Lue LF. Microglial chemotaxis, activation, and phagocytosis of amyloid beta-peptide as linked phenomena in Alzheimer's disease. Neurochem Int 2001; 39:333-40. [PMID: 11578768 DOI: 10.1016/s0197-0186(01)00040-7] [Citation(s) in RCA: 166] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Microglia are widely held to play important pathophysiologic roles in Alzheimer's disease (AD). On exposure to amyloid beta peptide (A beta) they exhibit chemotactic, phagocytic, phenotypic and secretory responses consistent with scavenger cell activity in a localized inflammatory setting. Because AD microglial chemotaxis, phagocytosis, and secretory activity have common, tightly linked soluble intermediaries (e.g., cytokines, chemokines), cell surface intermediaries (e.g., receptors, opsonins), and stimuli (e.g., highly inert A beta deposits and exposed neurofibrilly tangles), the mechanisms for microglial clearance of A beta are necessarily coupled to localized inflammatory mechanisms that can be cytotoxic to nearby tissue. This presents a critical dilemma for strategies to remove A beta by enhancing micoglial activation--a dilemma that warrants substantial further investigation.
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Affiliation(s)
- J Rogers
- L.J. Roberts Center for Alzheimer's Research, Sun Health Research Institute, P.O. Box 1278, 10515 West Santa Fe Drive, Sun City, AZ 85372, USA.
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1014
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Vehmas AK, Borchelt DR, Price DL, McCarthy D, Wills-Karp M, Peper MJ, Rudow G, Luyinbazi J, Siew LT, Troncoso JC. beta-Amyloid peptide vaccination results in marked changes in serum and brain Abeta levels in APPswe/PS1DeltaE9 mice, as detected by SELDI-TOF-based ProteinChip technology. DNA Cell Biol 2001; 20:713-21. [PMID: 11788049 DOI: 10.1089/10445490152717578] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Although the pathogenesis of Alzheimer's disease (AD) is not fully understood, growing evidence indicates that the deposition of beta-amyloid (Abeta) and the local reactions of various cell types to this protein play major roles in the development of the disease. Immunization with the Abeta 1-42 peptide has been reported to decrease Abeta deposits in the brains of mutant amyloid precursor protein (APP/V717F) transgenic (tg) mice (Schenk et al. Immunization with amyloid-beta attenuates Alzheimer-disease-like pathology in the PDAPP mouse. Nature 1999;400:173-177). We have replicated this finding in APPswe/PS1DeltaE9 tg mice, which also develop Abeta deposits in the brain. The immunized animals developed high titers of antibodies against Abeta 1-42 in serum, and Abeta deposits in the brains were significantly reduced. Using surface-enhanced laser desorption/ionization (SELDI) mass spectrometry and ProteinChip((R)) technology, we detected trends toward increased soluble Abeta peptide in the brain and a decrease in assayable Abeta peptide in the serum of immunized compared with control animals. This last finding raises the possibility that anti-Abeta antibodies in the periphery sequester Abeta peptides or target them for degradation and in this way contribute to the enhanced Abeta clearance from the brain in immunized animals.
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Affiliation(s)
- A K Vehmas
- Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196, USA
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1015
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Kontush A. Amyloid-beta: an antioxidant that becomes a pro-oxidant and critically contributes to Alzheimer's disease. Free Radic Biol Med 2001; 31:1120-31. [PMID: 11677045 DOI: 10.1016/s0891-5849(01)00688-8] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Elevated production of amyloid-beta (A beta) as a preventive antioxidant for brain lipoproteins under the action of increased oxidative stress in aging is postulated to represent a major event in the development of Alzheimer's disease (AD). Increase in A beta production is followed by chelation of transition metal ions by A beta, accumulation of A beta-metal lipoprotein aggregates, production of reactive oxygen species and neurotoxicity. Chelation of copper by A beta is proposed to be a most important part of this pathway, because A beta binds copper stronger than other transition metals and because copper is a more efficient catalyst of oxidation than other metals. This amyloid-binds-copper (ABC) model does not remove A beta peptide from its central place in our current thinking of AD, but rather places additional factors in the center of discussion. Most importantly, they embrace pathological mechanisms known to develop in aging (which is the major risk factor for AD), such as increased production of reactive oxygen species by mitochondria, that are positioned upstream relative to the generation of A beta.
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Affiliation(s)
- A Kontush
- Medical Clinic, University Hospital Eppendorf, Hamburg, Germany.
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1016
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Schenk D, Seubert P, Ciccarelli RB. Immunotherapy with beta-amyloid for Alzheimer's disease: a new frontier. DNA Cell Biol 2001; 20:679-81. [PMID: 11788045 DOI: 10.1089/10445490152717532] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's disease (AD) represents the fourth leading cause of death in the U.S. and the leading cause of dementia in the elderly population. Until recently, there was little hope of finding a way to prevent the underlying brain pathology from progressing toward the inevitable conclusion of the disease. However, new immunotherapeutic approaches have been described that are based on vaccination with the beta-amyloid 1-42 peptide (Abeta). The encouraging efficacy and safety of Abeta immunization in reducing neuropathology in animal models of AD has opened up new therapeutic possibilities for patients. Immunization with Abeta is aimed at reducing the Abeta-associated pathology of AD. It is hypothesized that this approach will also reduce the cascade of downstream events leading to neuronal cell loss and, ultimately, dementia. The ensuing articles in this issue describe various aspects of the Abeta immunization strategy and their potential relevance to AD treatment.
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Affiliation(s)
- D Schenk
- Elan Pharmaceuticals, South San Francisco, California 94080, USA
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1017
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Solomon B. Immunotherapeutic strategies for prevention and treatment of Alzheimer's disease. DNA Cell Biol 2001; 20:697-703. [PMID: 11788047 DOI: 10.1089/10445490152717550] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pathologic examination in Alzheimer's disease (AD) shows a significant correlation between beta-amyloid peptide (AbetaP) deposition and the clinical severity of dementia. Formation of beta-amyloid (Abeta) is a complex kinetic and thermodynamic process, dependent on peptide-peptide interactions that may be modulated by other proteins. We found that site-directed antibodies toward peptide EFRH sequences 3-6 of the N-terminal region of AbetaP suppress in vitro formation of Abeta and dissolve already-formed fibrillar amyloid. These so-called chaperone-like properties of monoclonal antibodies led to the development of a new immunologic approach to AD treatment. The immunization procedure, based on phages displaying the EFRH epitope as antigen, induced anti-AbetaP antibodies that recognized the whole AbetaP and exhibited antiaggregating properties similar to those of antibodies obtained by injection of Abeta fibrils. Production and performance of anti-beta-amyloid antibodies in the transgenic mouse model of AD showed that these antibodies may be delivered from the periphery to the central nervous system, preventing the formation of Abeta and dissolving already-present aggregates. Moreover, immunization with Abeta protected transgenic mice from the learning and age-related memory deficits that occur in AD. These data support the hypotheses that Abeta plays a central role in AD and that site-directed antibodies that modulate Abeta conformation may provide immunotherapy of the disease.
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Affiliation(s)
- B Solomon
- Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
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1018
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Lemere CA, Maron R, Selkoe DJ, Weiner HL. Nasal vaccination with beta-amyloid peptide for the treatment of Alzheimer's disease. DNA Cell Biol 2001; 20:705-11. [PMID: 11788048 DOI: 10.1089/10445490152717569] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's disease (AD) is a severe neurodegenerative disease for which there is currently no effective prevention or treatment. The prediction that the number of U.S. patients with AD will triple to approximately 14 million over the next 50 years underscores the urgent need to explore novel therapeutic strategies for AD. The beta-amyloid protein (Abeta) accumulation and accompanying inflammation appear to play key roles in initiating the neuronal degeneration that underlies the signs and symptoms of AD. Interventions geared toward reducing Abeta accumulation and inflammatory responses should delay or prevent the onset of the clinical disease. Recently, several research groups, including ours, have shown that vaccination with Abeta results in a significant lowering of the Abeta burden in the brains of APP transgenic mice and, in some studies, improvement in their cognitive deficits. Our study described a novel approach, namely mucosal (intranasal) Abeta vaccination. Precisely how Abeta vaccination chronically lowers Abeta levels and reduces Abeta-associated pathology remains unclear. Here, we provide an overview of these studies, with particular emphasis on our work with intranasal Abeta vaccination. Examples of other intranasal vaccines and mucosal adjuvants are presented. Taken together, these data have implications for the future development of an intranasal Abeta vaccine for humans.
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Affiliation(s)
- C A Lemere
- Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
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1019
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Dickey CA, Morgan DG, Kudchodkar S, Weiner DB, Bai Y, Cao C, Gordon MN, Ugen KE. Duration and specificity of humoral immune responses in mice vaccinated with the Alzheimer's disease-associated beta-amyloid 1-42 peptide. DNA Cell Biol 2001; 20:723-9. [PMID: 11788050 DOI: 10.1089/10445490152717587] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by overproduction of beta-amyloid (Abeta), which is formed from amyloid precursor protein (APP), with the subsequent pathologic deposition of Abeta in regions of the brain important for memory and cognition. Recently, vaccination of murine models of AD that exhibit Abeta deposition has halted or delayed the usual progression of the pathology of AD. Our group has demonstrated that vaccination of a doubly transgenic mouse model (expressing mutant APP and presenilin-1) with the Abeta 1-42 peptide protects these mice from the memory deficits they would ordinarily develop. This report further characterizes the Abeta 1-42 peptide vaccine in mice. Anti-Abeta response time course analysis indicated that at least three vaccinations (each 100 microg) were necessary to elicit a significant anti-Abeta titer. Subsequent vaccinations resulted in half-maximal antibody titers of at least 10,000, and these titers were maintained for at least 5 months after the final boost. Peptide binding competition studies indicated that the highest humoral responses are generated against the N terminus of the Abeta peptide. Also, measurement of specific murine Ig isotypes in Abeta-vaccinated mice demonstrated a predominant IgG(1) and IgG(2b) response, suggesting a type 2 (Th2) T-helper cell immune response, which drives humoral immunity. Finally, lymphocyte proliferation assay experiments using Abeta peptides and splenocytes from vaccinated mice demonstrated that the vaccine specifically stimulates T-cell epitopes present within the Abeta peptide.
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Affiliation(s)
- C A Dickey
- Alzheimer's Research Laboratory, University of South Florida, Tampa, Florida 33612, USA
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1020
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Harris-White ME, Chu T, Miller SA, Simmons M, Teter B, Nash D, Cole GM, Frautschy SA. Estrogen (E2) and glucocorticoid (Gc) effects on microglia and A beta clearance in vitro and in vivo. Neurochem Int 2001; 39:435-48. [PMID: 11578779 DOI: 10.1016/s0197-0186(01)00051-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The accumulation of fibrillar aggregates of beta Amyloid (A beta) in Alzheimer's Disease (AD) brain is associated with chronic brain inflammation. Although activated microglia (mu glia) can potentially clear toxic amyloid, chronic activation may lead to excessive production of neurotoxins. Recent epidemiological and clinical data have raised questions about the use of anti-inflammatory steroids (glucocorticoids, Gcs) and estrogens for treatment or prevention of AD. Since very little is known about steroid effects on mu glial interactions with amyloid, we investigated the effects of the synthetic Gc dexamethasone (DXM) and 17-beta estradiol (E2) in vitro in a murine mu glial-like N9 cell line on toxin production and intracellular A beta accumulation. To determine whether the steroid alterations of A beta uptake in vitro had relevance in vivo, we examined the effects of these steroids on A beta accumulation and mu glial responses to A beta infused into rat brain. Our in vitro data demonstrate for the first time that Gc dose-dependently enhanced mu glial A beta accumulation and support previous work showing that E2 enhances A beta uptake. Despite both steroids enhancing uptake, degradation was impeded, particularly with Gcs. Distinct differences between the two steroids were observed in their effect on toxin production and cell viability. Gc dose-dependently increased toxicity and potentiated A beta induction of nitric oxide, while E2 promoted cell viability and inhibited A beta induction of nitric oxide. The steroid enhancement of mu glial uptake and impedence of degradation observed in vitro were consistent with observations from in vivo studies. In the brains of A beta-infused rats, the mu glial staining in entorhinal cortex layer 3, not associated with A beta deposits was increased in response to A beta infusion and this effect was blocked by feeding rats prednisolone. In contrast, E2 enhanced mu glial staining in A beta-infused rats. A beta-immunoreactive (ir) deposits were quantitatively smaller, appeared denser, and were associated with robust mu glial responses. Despite the fact that steroid produced a smaller more focal deposit, total extracted A beta in cortical homogenate was elevated. Together, the in vivo and in vitro data support a role for steroids in plaque compaction. Our data are also consistent with the hypothesis that although E2 is less potent than Gc in impeding A beta degradation, long term exposure to both steroids could reduce A beta clearance and clinical utility. These data showing Gc potentiation of A beta-induced mu glial toxins may help explain the lack of epidemiological correlation for AD. The failure of both steroids to accelerate A beta degradation may explain their lack of efficacy for treatment of AD.
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Affiliation(s)
- M E Harris-White
- Department of Medicine, UCLA, C-128 RNRC, Los Angeles, CA 90095-1769, USA
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1021
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Weiner DB. Introduction to Inaugural Issue of Frontiers in Molecular Medicine. DNA Cell Biol 2001. [DOI: 10.1089/10445490152717514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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1022
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Poduslo JF, Curran GL. Amyloid beta peptide as a vaccine for Alzheimer's disease involves receptor-mediated transport at the blood-brain barrier. Neuroreport 2001; 12:3197-200. [PMID: 11711855 DOI: 10.1097/00001756-200110290-00011] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Much research is now focused on a potential vaccine for Alzheimer's disease (AD). Current studies involve administering the amyloid beta peptide (Abeta) in Freund's complete adjuvant, which cannot be used in humans. Our studies show that the immune complex of Abeta is taken up by a receptor-mediated process at the blood-brain barrier (BBB). The success of immunization for AD, therefore, may be critically dependent on circulating Abeta levels which are lower in AD patients compared to AD transgenic mice. Moreover, we have found that modifying the antibody with polyamine increases its BBB permeability and may provide a better approach to passive immunization for Alzheimer's disease.
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Affiliation(s)
- J F Poduslo
- Molecular Neurobiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
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1023
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Thomas T, Nadackal TG, Thomas K. Aspirin and non-steroidal anti-inflammatory drugs inhibit amyloid-beta aggregation. Neuroreport 2001; 12:3263-7. [PMID: 11711868 DOI: 10.1097/00001756-200110290-00024] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The neurotoxic and proinflammatory actions of the Alzheimer peptide amyloid-beta (Abeta) are dependent on its aggregation and beta-sheet conformation. Chronic use of non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin for arthritis decreases the risk of developing Alzheimer's disease (AD) by unknown mechanisms. We report that these drugs inhibit human Abeta aggregation in vitro and reverse the beta-sheet conformation of preformed fibrils at clinically relevant doses. Aspirin prevented enhanced Abeta aggregation by aluminum, an environmental risk factor for AD. This anti-aggregatory effect was restricted to NSAIDs and was not exhibited by other drugs used in AD therapy. NSAIDS may have a role in the prevention and treatment of AD, in addition to a number of age-related disorders such as arthritis, cardiovascular disease and cancer.
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Affiliation(s)
- T Thomas
- Woodlands Medical Center and Endron Therapeutics, 3150 Tampa Road, #16 Oldsmar, FL 34677, USA
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1024
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Familial amyloid polyneuropathy: receptor for advanced glycation end products-dependent triggering of neuronal inflammatory and apoptotic pathways. J Neurosci 2001. [PMID: 11567048 DOI: 10.1523/jneurosci.21-19-07576.2001] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Familial amyloid polyneuropathy (FAP) is a neurodegenerative disorder associated with extracellular deposition of mutant transthyretin (TTR) amyloid fibrils, particularly in the peripheral nervous system. We have hypothesized that binding of TTR fibrils to the receptor for advanced glycation end products (RAGE) on critical cellular targets is associated with a destructive stress response underlying peripheral nerve dysfunction. Analysis of nerve biopsy samples from patients with FAP (n = 16) at different stages of disease (0-3), compared with age-matched controls (n = 4), by semiquantitative immunohistology and in situ hybridization showed increased levels of RAGE, beginning at the earliest stages of the disease (FAP 0; p < 0.02) and especially localized in axons. Upregulation of proinflammatory cytokines (tumor necrosis factor-alpha and interleukin-1beta) (approximately threefold; p < 0.02) and the inducible form of nitric oxide synthase (iNOS) ( approximately 2.5-fold; p < 0.04) was also observed in a distribution overlapping RAGE expression. Tyrosine nitration and increased activated caspase-3 in axons from FAP patients (p < 0.03) were apparent. Although these data suggest the presence of ongoing neuronal stress, there was no upregulation of neurotrophins (nerve growth factor and neurotrophin-3) in FAP nerves. Studies on cultured neuronal-like, Schwann, and endothelial cells incubated with TTR fibrils displayed RAGE-dependent expression of cytokines and iNOS at early times (6 and 12 hr, respectively), followed by later (24 hr) activation of caspase-3 and DNA fragmentation. We propose that the interaction of TTR fibrils with RAGE may contribute to cellular stress and toxicity in FAP. Furthermore, there is an apparent lack of responsiveness of Schwann cells in FAP nerve to provide neurotrophic factors.
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1025
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Kirkitadze MD, Condron MM, Teplow DB. Identification and characterization of key kinetic intermediates in amyloid beta-protein fibrillogenesis. J Mol Biol 2001; 312:1103-19. [PMID: 11580253 DOI: 10.1006/jmbi.2001.4970] [Citation(s) in RCA: 557] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Amyloid beta-protein (Abeta) assembly into toxic oligomeric and fibrillar structures is a seminal event in Alzheimer's disease, therefore blocking this process could have significant therapeutic benefit. A rigorous mechanistic understanding of Abeta assembly would facilitate the targeting and design of fibrillogenesis inhibitors. Prior studies have shown that Abeta fibrillogenesis involves conformational changes leading to the formation of extended beta-sheets and that an alpha-helix-containing intermediate may be involved. However, the significance of this intermediate has been a matter of debate. We report here that the formation of an oligomeric, alpha-helix-containing assembly is a key step in Abeta fibrillogenesis. The generality of this phenomenon was supported by conformational studies of 18 different Abeta peptides, including wild-type Abeta(1-40) and Abeta(1-42), biologically relevant truncated and chemically modified Abeta peptides, and Abeta peptides causing familial forms of cerebral amyloid angiopathy. Without exception, fibrillogenesis of these peptides involved an oligomeric alpha-helix-containing intermediate and the kinetics of formation of the intermediate and of fibrils was temporally correlated. The kinetics varied depending on amino acid sequence and the extent of peptide N- and C-terminal truncation. The pH dependence of helix formation suggested that Asp and His exerted significant control over this process and over fibrillogenesis in general. Consistent with this idea, Abeta peptides containing Asp-->Asn or His-->Gln substitutions showed altered fibrillogenesis kinetics. These data emphasize the importance of the dynamic interplay between Abeta monomer conformation and oligomerization state in controlling fibrillogenesis kinetics.
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Affiliation(s)
- M D Kirkitadze
- Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA
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1026
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Abstract
Alzheimer's disease (AD) afflicts 4 million people in the United States and is expected to strike 14 million by the year 2050, as the population ages. Researchers are scrambling to find genetic risk factors, decipher disease mechanisms, and develop reliable diagnostic tests that detect the illness at its earliest, potentially most treatable stage. Using these findings, they hope to devise new therapeutic approaches. Current clinical trials are testing novel techniques that stall or reverse AD-like neuropathology in mice.
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1027
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Affiliation(s)
- Neil A Mabbott
- Institute for Animal Health, Neuropathogenesis Unit, Ogston Building, West Mains Road, Edinburgh EH9 3JF, UK1
| | - Moira E Bruce
- Institute for Animal Health, Neuropathogenesis Unit, Ogston Building, West Mains Road, Edinburgh EH9 3JF, UK1
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1028
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Refolo LM, Pappolla MA, LaFrancois J, Malester B, Schmidt SD, Thomas-Bryant T, Tint GS, Wang R, Mercken M, Petanceska SS, Duff KE. A cholesterol-lowering drug reduces beta-amyloid pathology in a transgenic mouse model of Alzheimer's disease. Neurobiol Dis 2001; 8:890-9. [PMID: 11592856 DOI: 10.1006/nbdi.2001.0422] [Citation(s) in RCA: 369] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Clinical, epidemiological, and laboratory studies suggest that cholesterol may play a role in the pathogenesis of Alzheimer's disease (AD). Transgenic mice exhibiting an Alzheimer's beta-amyloid phenotype were treated with the cholesterol-lowering drug BM15.766 and tested for modulation of beta-amyloid levels. BM15.766 treatment reduced plasma cholesterol, brain Abeta peptides, and beta-amyloid load by greater than twofold. A strong, positive correlation between the amount of plasma cholesterol and Abeta was observed. Furthermore, drug treatment reduced the amyloidogenic processing of the amyloid precursor protein, suggesting alterations in processing in response to cholesterol modulation. This study demonstrates that hypocholesterolemia is associated with reduced Abeta accumulation suggesting that lowering cholesterol by pharmacological means may be an effective approach for reducing the risk of developing AD.
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Affiliation(s)
- L M Refolo
- Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962, USA.
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1029
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Abstract
Recent advances in the understanding of the genetic basis of Alzheimer's disease have enabled the production of transgenic mouse models of the disease. Utilizing both cDNA- and genomic-based approaches, these mouse models for Alzheimer's disease have already provided valuable insights into the pathogenesis of the disease and potential therapeutic interventions.
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Affiliation(s)
- B J Hock
- Dept of Genetics, Case Western Reserve University, University Hospitals of Cleveland, 10900 Euclid Avenue, Cleveland, OH 44106-4955, USA
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1030
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Morris RG. Episodic-like memory in animals: psychological criteria, neural mechanisms and the value of episodic-like tasks to investigate animal models of neurodegenerative disease. Philos Trans R Soc Lond B Biol Sci 2001; 356:1453-65. [PMID: 11571036 PMCID: PMC1088528 DOI: 10.1098/rstb.2001.0945] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The question of whether any non-human species displays episodic memory is controversial. Associative accounts of animal learning recognize that behaviour can change in response to single events but this does not imply that animals need or are later able to recall representations of unique events at a different time and place. The lack of language is also relevant, being the usual medium for communicating about the world, but whether it is critical for the capacity to represent and recall events is a separate matter. One reason for suspecting that certain animals possess an episodic-like memory system is that a variety of learning and memory tasks have been developed that, even though they do not meet the strict criteria required for episodic memory, have an 'episodic-like' character. These include certain one-trial learning tasks, scene-specific discrimination learning, multiple reversal learning, delayed matching and non-matching tasks and, most recently, tasks demanding recollection of 'what, where and when' an event happened. Another reason is that the neuronal architecture of brain areas thought to be involved in episodic memory (including the hippocampal formation) are substantially similar in mammals and, arguably, all vertebrates. Third, our developing understanding of activity-dependent synaptic plasticity (which is a candidate neuronal mechanism for encoding memory traces) suggests that its expression reflects certain physiological characteristics that are ideal components of a neuronal episodic memory system. These include the apparently digital character of synaptic change at individual terminals and the variable persistence of potentiation accounted for by the synaptic tag hypothesis. A further value of studying episodic-like memory in animals is the opportunity it affords to model certain kinds of neurodegenerative disease that, in humans, affect episodic memory. An example is recent work on a transgenic mouse that over-expresses a mutation of human amyloid precursor protein (APP) that occurs in familial Alzheimer's disease, under the control of platelet derived (PD) growth factor promoter (the PDAPP mouse). A striking age- and amyloid plaque-related deficit is seen using a task in which the mice have to keep changing their memory representation of the world rather than learn a single fact.
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Affiliation(s)
- R G Morris
- Department of Neuroscience, The University of Edinburgh, 1 George Square, Edinburgh EH8 9JZ, UK.
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1031
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Das P, Murphy MP, Younkin LH, Younkin SG, Golde TE. Reduced effectiveness of Abeta1-42 immunization in APP transgenic mice with significant amyloid deposition. Neurobiol Aging 2001; 22:721-7. [PMID: 11705631 DOI: 10.1016/s0197-4580(01)00245-7] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Vaccinations with Abeta1-42 have been shown to reduce amyloid burden in transgenic models of Alzheimer's disease (AD). We have further tested the efficacy of Abeta1-42 immunization in the Tg2576 mouse model of AD by immunizing one group of mice with minimal Abeta deposition, one group of mice with modest Abeta deposition, and one group with significant Abeta deposition. The effects of immunization on Abeta deposition were examined using biochemical and immunohistochemical methods. In Tg2576 mice immunized prior to significant amyloid deposition, Abeta1-42 immunization was highly effective. Biochemically extracted Abeta40 and Abeta42 levels were significantly reduced and immunohistochemical plaque load was also reduced. Immunization of mice with modest amounts of pre-existing Abeta deposits selectively reduced Abeta42 without altering Abeta40, although plaque load was reduced. In contrast, in Tg2576 mice with significant pre-existing Abeta loads, Abeta1-42 immunization only minimally decreased Abeta42 levels, whereas no alteration in Abeta40 levels or in plaque load was observed. These results indicate that in Tg2576 mice, Abeta1-42 immunization is more effective at preventing additional Abeta accumulation and does not result in significant clearance of pre-existing Abeta deposits.
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Affiliation(s)
- P Das
- Department of Neurosciences, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, Florida 32224, USA
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1032
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Tickler AK, Barrow CJ, Wade JD. Improved preparation of amyloid-beta peptides using DBU as Nalpha-Fmoc deprotection reagent. J Pept Sci 2001; 7:488-94. [PMID: 11587187 DOI: 10.1002/psc.342] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Previous studies have shown the amyloid peptides, Abeta 1-40/42, to be exceptionally difficult to assemble by Fmoc-solid phase peptide synthesis due to the high hydrophobicity of the C-terminal segment and resulting on-resin aggregation. We found that the use of the stronger and more efficient base, DBU, at a concentration of 2% in DMF for Nalpha-Fmoc deprotection allowed substantially improved continuous flow solid phase assembly of the model peptide Abeta 29-40/42 fragments. This suggested that, at least for these sequences, incomplete deprotection was a greater problem than incomplete amino acid acylation. This base was then used during the synthesis of both Abeta 1-40 and Abeta 1-42, up to and including Ser8, from which point 20% piperidine in DMF was utilized so as to avoid potential aspartimide formation at Asp7. By this means, the deprotection efficiency through the difficult C-terminal portion of the sequence was much improved and resulted in increased availability of terminal amino groups for acylation. This simple strategy that obviates the need for special conditions significantly improved crude peptide quality and allowed considerable facilitation of subsequent purification.
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Affiliation(s)
- A K Tickler
- Howard Florey Institute of Experimental Physiology and Medicine, The University of Melbourne, Victoria, Australia
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1033
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Janus C, Phinney AL, Chishti MA, Westaway D. New developments in animal models of Alzheimer's disease. Curr Neurol Neurosci Rep 2001; 1:451-7. [PMID: 11898556 DOI: 10.1007/s11910-001-0105-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease (AD) is characterized by deterioration in mental function leading to dementia, deposition of amyloid plaques and neurofibrillary tangles (NFTs), and neuronal loss. The major component of plaques is the amyloid-beta peptide (A beta), whereas NFTs are assemblies of hyperphosphorylated forms of the microtubule-associated protein tau. Electron microscopy of NFTs reveals structures known as paired helical filaments (PHFs). In familial AD (FAD), mutations in three distinct genes drive A beta synthesis by favoring endoproteolytic secretase cleavages that liberate A beta from the Alzheimer beta-amyloid precursor protein (APP). This suggests that excess A beta initiates a pathogenic cascade in humans that culminates in all the pathologic and cellular hallmarks of AD. Building upon the knowledge of FAD mutations, incremental technical advances have now allowed reproduceable creation of APP transgenic mice that exhibit AD-like amyloid pathology and A beta burdens. These transgenic mouse lines also exhibit deficits in spatial reference and working memory, with immunization against A beta abrogating both AD-associated phenotypes. Besides establishing a proof of principle for A beta-directed therapies, these findings suggest a potential to identify individual elements in the pathogenic pathway that lead to cognitive dysfunction. Furthermore, transgenic APP mice with potent amyloid deposition will likely form a beach-head to capture the final elements of AD neuropathology--cell loss and NFTs composed of PHFs--that are missing from current transgenic models.
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Affiliation(s)
- C Janus
- Centre for Research in Neurodegenerative Diseases, University of Toronto, Tanz Neuroscience Building, 6 Queen's Park Crescent West, Toronto, Ontario M55 3H2, Canada
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1034
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Matsuoka Y, Picciano M, La Francois J, Duff K. Fibrillar beta-amyloid evokes oxidative damage in a transgenic mouse model of Alzheimer's disease. Neuroscience 2001; 104:609-13. [PMID: 11440793 DOI: 10.1016/s0306-4522(01)00115-4] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Beta-amyloid is one of the most significant features of Alzheimer's disease, and has been considered to play a pivotal role in neurodegeneration through an unknown mechanism. However, it has been noted that beta-amyloid accumulation is associated with markers of oxidative stress including protein oxidation (Smith et al., 1997), lipid peroxidation (Mark et al., 1997; Sayre et al., 1997), advanced glycation end products (Smith et al., 1994), and oxidation of nucleic acids (Nunomura et al., 1999). Furthermore, studies from cultured cells have shown that beta-amyloid leads to an increase in hydrogen peroxide levels (Behl et al., 1994), and the production of reactive oxygen intermediates (Harris et al., 1995). Taken together, this evidence supports the idea that beta-amyloid plays a key role in oxidative stress-evoked neuropathology. In this study, we examined the induction of oxidative stress in response to amyloid load in a mouse model of Alzheimer's disease. The mice carrying mutant amyloid precursor protein and presenilins-1 (Goate et al., 1991; Hardy, 1997), develops beta-amyloid deposits at 10-12 weeks of age and show several features of the human disease (Holcomb et al., 1998; Matsuoka et al., 2001; McGowan et al., 1999; Takeuchi et al., 2000; Wong et al., 1999). Both 3-nitrotyrosine and 4-hydroxy-2-nonenal (protein and lipid oxidative stress markers, respectively) associate strongly with fibrillar beta-amyloid, but not with diffuse (thioflavine S negative) beta-amyloid, and the levels increase in relation to the age-associated increase in fibrillar amyloid load.From these data we suggest that fibrillar beta-amyloid is associated with oxidative damage which may influence disease progression in the Alzheimer's disease brain.
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Affiliation(s)
- Y Matsuoka
- Dementia Research Group, Nathan Kline Institute/New York University Medical Center, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA
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1035
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Monsonego A, Maron R, Zota V, Selkoe DJ, Weiner HL. Immune hyporesponsiveness to amyloid beta-peptide in amyloid precursor protein transgenic mice: implications for the pathogenesis and treatment of Alzheimer's disease. Proc Natl Acad Sci U S A 2001; 98:10273-8. [PMID: 11517335 PMCID: PMC56951 DOI: 10.1073/pnas.191118298] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Alzheimer's disease is a dementia that involves progressive deposition of amyloid beta-protein (Abeta) in brain regions important for memory and cognition, followed by secondary inflammation that contributes to the neuropathologic process. Immunization with Abeta can reduce cerebral Abeta burden and consequent neuropathologic changes in the brains of mice transgenic for the beta-amyloid precursor protein (APP). We found that transgenic expression of human APP in B6SJL mice, under the prion promoter, results in immune hyporesponsiveness to human Abeta, in terms of both antibody and cellular immune responses. The decreased antibody responses were related not to B cell tolerance but rather to the inability of Abeta-specific T cells to provide help for antibody production. The immune hyporesponsiveness could be overcome if T cell help was provided by coupling an Abeta B cell epitope to BSA. Our results suggest that expression of APP in transgenic mice is associated with an Abeta-specific impaired adaptive immune response that may contribute to the neuropathology. Moreover, humans with life-long elevation of brain and peripheral Abeta (e.g., patients with presenilin mutations or Down syndrome) could have reduced immune responses to Abeta vaccination.
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Affiliation(s)
- A Monsonego
- Center for Neurologic Diseases, Harvard Medical School and Brigham and Women's Hospital, 77 Avenue Louis Pasteur, HIM 730, Boston, MA 02115, USA
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1036
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Hoozemans JJ, Rozemuller AJ, Veerhuis R, Eikelenboom P. Immunological aspects of alzheimer's disease: therapeutic implications. BioDrugs 2001; 15:325-37. [PMID: 11437695 DOI: 10.2165/00063030-200115050-00004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease causing progressive impairment of memory and cognitive function. The amyloid cascade hypothesis suggests that mismetabolism of the beta-amyloid (A beta) precursor protein (APP) followed by subsequent formation of non-fibrillar and fibrillar A beta deposits leads to glial activation and eventually to neurotoxicity, causing cognitive impairment. Several lines of evidence indicate that an inflammatory process contributes to the pathology of AD. First, inflammatory proteins have been identified as being associated with neuritic plaques and in glial cells surrounding these plaques. Second, certain polymorphisms of acute-phase proteins and cytokines associated with AD plaques increase the risk or predispose for earlier onset of developing AD. Third, epidemiological studies indicate that anti-inflammatory drugs can retard the development of AD. Several steps in the pathological cascade of AD have been identified as possible targets for actions of nonsteroidal anti-inflammatory drugs. For instance, microglia are considered a target because this cell type is closely involved in AD pathology through secretion of neurotoxic substances and by modulating a positive feedback loop of the inflammatory mechanism that may be involved in the pathological cascade in AD. On the basis of studies in APP transgenic mice, immunisation with A beta was recently suggested as a novel immunological approach for the treatment of AD. Immunisation elicits A beta-specific antibodies that could affect several early steps of the amyloid-driven cascade. Antibodies could prevent A beta from aggregating into fibrils and accelerate clearance of A beta by stimulating its removal by microglial cells. This review outlines the pathological and genetic evidence that an inflammatory mechanism is involved in AD and the therapeutic approaches based on inhibition or mediation of inflammation.
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Affiliation(s)
- J J Hoozemans
- Department of Psychiatry, Vrije Universiteit Medical Center, Amsterdam, The Netherlands.
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1037
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Abstract
Major advances in vaccinology in the past year include the experimental use of vaccination for diseases such as Alzheimer's and stroke, a demonstration of the power of genomic approaches for target antigen identification, hopeful results in a clinical trial for a therapeutic cancer vaccine, and the successful mass immunisation of children with meningococcal conjugate vaccine in the UK.
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Affiliation(s)
- A W Heath
- Division of Genomic Medicine, University of Sheffield Medical School, UK.
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1038
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Mattson MP, Chan SL, Camandola S. Presenilin mutations and calcium signaling defects in the nervous and immune systems. Bioessays 2001; 23:733-44. [PMID: 11494322 DOI: 10.1002/bies.1103] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Presenilin-1 (PS1) is thought to regulate cell differentiation and survival by modulating the Notch signaling pathway. Mutations in PS1 have been shown to cause early-onset inherited forms of Alzheimer's disease (AD) by a gain-of-function mechanism that alters proteolytic processing of the amyloid precursor protein (APP) resulting in increased production of neurotoxic forms of amyloid beta-peptide. The present article considers a second pathogenic mode of action of PS1 mutations, a defect in cellular calcium signaling characterized by overfilling of endoplasmic reticulum (ER) calcium stores and altered capacitive calcium entry; this abnormality may impair synaptic plasticity and sensitize neurons to apoptosis and excitotoxicity. The calcium signaling defect has also been documented in lymphocytes, suggesting a contribution of immune dysfunction to the pathogenesis of AD. A better understanding of the calcium signaling defect resulting from PS1 mutations may lead to the development of novel preventative and therapeutic strategies for disorders of the nervous and immune systems.
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Affiliation(s)
- M P Mattson
- Laboratory of Neurosciences, National Institute on Aging Gerontology Research Center, Baltimore, MD 21224, USA.
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1039
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Abstract
Transgenic mouse models exist for the major neurodegenerative diseases, including Alzheimer's disease, tauopathy and amyotrophic lateral sclerosis. Although many of the mice do not completely replicate the human disease they are intended to model, they have provided insight into the mechanisms that underlie disease etiology. In the case of the Alzheimer's disease and amyotrophic lateral sclerosis models, the mice have also provided a therapeutic testing ground for the testing of agents that have been shown to have considerable clinical promise.
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Affiliation(s)
- K Duff
- Nathan Kline Institute, New York, New York 10962, USA.
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1040
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Le R, Cruz L, Urbanc B, Knowles RB, Hsiao-Ashe K, Duff K, Irizarry MC, Stanley HE, Hyman BT. Plaque-induced abnormalities in neurite geometry in transgenic models of Alzheimer disease: implications for neural system disruption. J Neuropathol Exp Neurol 2001; 60:753-8. [PMID: 11487049 DOI: 10.1093/jnen/60.8.753] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Neurites that pass through amyloid-beta deposits in Alzheimer disease (AD) undergo 3 changes: they develop phosphorylated tau immunoreactivity; the density of SMI-32-positive dendrites diminishes; and they also develop a marked alteration in their geometric features, changing from being nearly straight to being quite curvy. The extent to which the latter 2 phenomena are related to phosphorylated tau is unknown. We have now examined whether amyloid-beta deposits in APP695Sw transgenic mice, which have only rare phosphorylated tau containing neurites. develop these changes. We found that dendritic density is diminished within the boundaries of amyloid-beta plaques, with the greatest loss (about 80%, p < 0.001) within the boundaries of thioflavine S cores. Remaining dendrites within plaques develop substantial morphological alterations quantitatively similar to those seen in AD. A statistically significant but smaller degree of change in geometry was seen in the immediate vicinity around plaques, suggesting a propagation of cytoskeletal disruption from the center of the plaque outward. We examined the possible physiological consequences of this change in dendritic geometry using a standard cable-theory model. We found a predicted delay of several milliseconds in about one quarter of the dendrites passing through a thioflavine S plaque. These results are consistent with previous observations in AD, and suggest that thioflavine S-positive amyloid-beta deposits have a marked effect on dendritic microarchitecture in the cortex, even in the relative absence of phosphorylated tau alterations.
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Affiliation(s)
- R Le
- Department of Neurology, Massachusetts General Hospital, Charlestown, USA
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1041
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Jaffar S, Counts SE, Ma SY, Dadko E, Gordon MN, Morgan D, Mufson EJ. Neuropathology of mice carrying mutant APP(swe) and/or PS1(M146L) transgenes: alterations in the p75(NTR) cholinergic basal forebrain septohippocampal pathway. Exp Neurol 2001; 170:227-43. [PMID: 11476589 DOI: 10.1006/exnr.2001.7710] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cholinergic basal forebrain (CBF) projection systems are defective in late Alzheimer's disease (AD). We examined the brains of 12-month-old singly and doubly transgenic mice overexpressing mutant amyloid precursor protein (APP(swe)) and/or presenilin-1 (PS1(M146L)) to investigate the effects of these AD-related genes on plaque and tangle pathology, astrocytic expression, and the CBF projection system. Two types of beta-amyloid (Abeta)-immunoreactive (ir) plaques were observed: type 1 were darkly stained oval and elongated deposits of Abeta, and type 2 were diffuse plaques containing amyloid fibrils. APP(swe) and PS1(M146L) mouse brains contained some type 1 plaques, while the doubly transgenic (APP(swe)/PS1(M146L)) mice displayed a greater abundance of types 1 and 2 plaques. Sections immunostained for the p75 NGF receptor (p75(NTR)) revealed circular patches scattered throughout the cortex and hippocampus of the APP(swe)/PS1(M146L) mice that contained Abeta, were innervated by p75(NTR)-ir neurites, but displayed virtually no immunopositive neurons. Tau pathology was not seen in any transgenic genotype, although a massive glial response occurred in the APP(swe)/PS1(M146L) mice associated with amyloid plaques. Stereology revealed a significant increase in p75(NTR)-ir medial septal neurons in the APP(swe) and PS1(M146L) singly transgenic mice compared to the APP(swe)/PS1(M146L) mice. No differences in size or optical density of p75(NTR)-ir neurons were observed in these three mutants. p75(NTR)-ir fibers in hippocampus and cortex were more pronounced in the APP(swe) and PS1(M146L) mice, while the APP(swe)/PS1(M146L) mice showed the least p75(NTR)-ir fiber staining. These findings suggest a neurotrophic role for mutant APP and PS1 upon cholinergic hippocampal projection neurons at 12 months of age.
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Affiliation(s)
- S Jaffar
- Department of Neurological Sciences, Rush Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA
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1042
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Sigurdsson EM, Scholtzova H, Mehta PD, Frangione B, Wisniewski T. Immunization with a nontoxic/nonfibrillar amyloid-beta homologous peptide reduces Alzheimer's disease-associated pathology in transgenic mice. THE AMERICAN JOURNAL OF PATHOLOGY 2001; 159:439-47. [PMID: 11485902 PMCID: PMC1850561 DOI: 10.1016/s0002-9440(10)61715-4] [Citation(s) in RCA: 209] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transgenic mice with brain amyloid-beta (Abeta) plaques immunized with aggregated Abeta1-42 have reduced cerebral amyloid burden. However, the use of Abeta1-42 in humans may not be appropriate because it crosses the blood brain barrier, forms toxic fibrils, and can seed fibril formation. We report that immunization in transgenic APP mice (Tg2576) for 7 months with a soluble nonamyloidogenic, nontoxic Abeta homologous peptide reduced cortical and hippocampal brain amyloid burden by 89% (P = 0.0002) and 81% (P = 0.0001), respectively. Concurrently, brain levels of soluble Abeta1-42 were reduced by 57% (P = 0.0019). Ramified microglia expressing interleukin-1beta associated with the Abeta plaques were absent in the immunized mice indicating reduced inflammation in these animals. These promising findings suggest that immunization with nonamyloidogenic Abeta derivatives represents a potentially safer therapeutic approach to reduce amyloid burden in Alzheimer's disease, instead of using toxic Abeta fibrils.
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Affiliation(s)
- E M Sigurdsson
- Department of Neurology, New York University School of Medicine, 550 First Ave., New York, NY 10016, USA.
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1043
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Abstract
Recent advances in experimental genomics, coupled with the wealth of sequence information available for a variety of organisms, have the potential to transform the way pharmacological research is performed. At present, high-density DNA microarrays allow researchers to quickly and accurately quantify gene-expression changes in a massively parallel manner. Although now well established in other biomedical fields, such as cancer and genetics research, DNA microarrays have only recently begun to make significant inroads into pharmacology. To date, the major focus in this field has been on the general application of DNA microarrays to toxicology and drug discovery and design. This review summarizes the major microarray findings of relevance to neuropsychopharmacology, as a prelude to the design and analysis of future basic and clinical microarray experiments. The ability of DNA microarrays to monitor gene expression simultaneously in a large-scale format is helping to usher in a post-genomic age, where simple constructs about the role of nature versus nurture are being replaced by a functional understanding of gene expression in living organisms.
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Affiliation(s)
- E R Marcotte
- Douglas Hospital Research Centre, Dept of Psychiatry, Faculty of Medicine, McGill University, Montreal, Quebec, Canada H4H 1R3
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1044
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Affiliation(s)
- V M Lee
- Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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1045
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Enari M, Flechsig E, Weissmann C. Scrapie prion protein accumulation by scrapie-infected neuroblastoma cells abrogated by exposure to a prion protein antibody. Proc Natl Acad Sci U S A 2001; 98:9295-9. [PMID: 11470893 PMCID: PMC55414 DOI: 10.1073/pnas.151242598] [Citation(s) in RCA: 327] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Exposure of susceptible neuroblastoma N2a cells to mouse scrapie prions leads to infection, as evidenced by the continued presence of the scrapie form of the prion protein (PrP(Sc)) and infectivity after 300 or more cell doublings. We find that exposure to phosphatidylinositol-specific phospholipase C (PIPLC) or to the monoclonal anti-prion protein (PrP) antibody 6H4 not only prevents infection of susceptible N2a cells but also cures chronically scrapie-infected cultures, as judged by the long-term abrogation of PrP(Sc) accumulation after cessation of treatment. A nonpassaged, stationary infected culture rapidly loses PrP(Sc) when exposed to the antibody or PIPLC, indicating that the PrP(Sc) level is determined by steady state equilibrium between formation and degradation, and that depletion of the cellular form of PrP can interrupt the propagation of PrP(Sc). These findings encourage the belief that passive immunization may provide a therapeutic approach to prion disease.
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Affiliation(s)
- M Enari
- Medical Research Council Prion Unit, Neurogenetics, Imperial College School of Medicine at St. Mary's, London W2 1PG, United Kingdom
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1046
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Brayden DJ, Templeton L, McClean S, Barbour R, Huang J, Nguyen M, Ahern D, Motter R, Johnson-Wood K, Vasquez N, Schenk D, Seubert P. Encapsulation in biodegradable microparticles enhances serum antibody response to parenterally-delivered beta-amyloid in mice. Vaccine 2001; 19:4185-93. [PMID: 11457544 DOI: 10.1016/s0264-410x(01)00162-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Poly(lactide-co-glycolide) (PLG) microspheres were tested as a parenteral delivery system for human beta-amyloid (1-42) (Abeta), a potential immunotherapeutic undergoing assessment in Phase 1 studies for Alzheimer's disease (AD). Abeta was successfully encapsulated in PLG microspheres of average sizes of 3 or 15 microm diameter. Swiss Webster (SW) mice were injected by the sub-cutaneous (s.c.) or intra-peritoneal (i.p.) routes with 3-33 microg Abeta. Abeta-PLG microparticles (3 microm) induced dose-dependent antibody responses, which were maximal at 33 microg Abeta, while Abeta in phosphate-buffered saline (PBS) produced weak antibody responses at the same doses by both routes. Significantly increased antibody responses were seen for both small and large particle formulations given by the i.p. route in comparison to the s.c route. It was previously reported that passive immunisation with Abeta-specific antibodies cleared amyloid plaques in a mouse model of AD (Bard F, Cannon C, Barbour R, et al. Peripherally administered antibodies against amyloid beta-peptide enter the nervous system and reduce pathology in a mouse model of Alzheimer disease. Nature Med 2000;6:916-19), an indication that induction of serum antibody is a prerequisite for efficacy.
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Affiliation(s)
- D J Brayden
- Elan Biotechnology Research, Biotechnology Building, Trinity College, 2, Dublin, Ireland.
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1047
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Town T, Tan J, Sansone N, Obregon D, Klein T, Mullan M. Characterization of murine immunoglobulin G antibodies against human amyloid-beta1-42. Neurosci Lett 2001; 307:101-4. [PMID: 11427310 DOI: 10.1016/s0304-3940(01)01951-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
It has been demonstrated that immunization of transgenic mouse models of Alzheimer's disease (AD) with amyloid-beta1-42 peptide (Abeta1-42) results in amelioration of AD-like pathology, including reduced soluble and deposited beta-amyloid and decreased cognitive impairment. Based on the proposed importance of immunoglobulin G (IgG) anti-Abeta antibodies (Abs) in these effects, we sought to characterize these Abs in splenocytes from mice immunized with Abeta1-42. Data show that a more aggregated preparation of Abeta1-42 gives a robust IgG anti-Abeta Ab response, while these Abs are almost undetectable when a less aggregated preparation of Abeta1-42 is used as the immunogen. Importantly, IgG anti-Abeta Ab production is detected after just 12 weeks of Abeta1-42 treatment. Analysis of anti-Abeta Ab IgG isotypes reveals that the majority of these Abs are IgG1, with significantly fewer Abs of the IgG2a or IgG2b isotypes (IgG1>IgG2a>IgG2b), suggesting a T lymphocyte helper type II response after Abeta1-42 immunization. To determine the epitope of Abeta recognized by IgG anti-Abeta Abs, intact Abeta and Abeta peptide fragments were analyzed for their ability to bind these Abs. Data show that these Abs specifically recognize an amino-terminal epitope of Abeta between amino acids one and twelve, with higher affinity for a more soluble preparation of Abeta1-42. These data further indicate the immunogenic potential of Abeta1-42 and offer insight into the nature of the IgG anti-Abeta Ab response.
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Affiliation(s)
- T Town
- The Roskamp Institute, University of South Florida, 3515 E. Fletcher Avenue, Tampa, FL 33613, USA.
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1048
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Chishti MA, Yang DS, Janus C, Phinney AL, Horne P, Pearson J, Strome R, Zuker N, Loukides J, French J, Turner S, Lozza G, Grilli M, Kunicki S, Morissette C, Paquette J, Gervais F, Bergeron C, Fraser PE, Carlson GA, George-Hyslop PS, Westaway D. Early-onset amyloid deposition and cognitive deficits in transgenic mice expressing a double mutant form of amyloid precursor protein 695. J Biol Chem 2001; 276:21562-70. [PMID: 11279122 DOI: 10.1074/jbc.m100710200] [Citation(s) in RCA: 677] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We have created early-onset transgenic (Tg) models by exploiting the synergistic effects of familial Alzheimer's disease mutations on amyloid beta-peptide (Abeta) biogenesis. TgCRND8 mice encode a double mutant form of amyloid precursor protein 695 (KM670/671NL+V717F) under the control of the PrP gene promoter. Thioflavine S-positive Abeta amyloid deposits are present at 3 months, with dense-cored plaques and neuritic pathology evident from 5 months of age. TgCRND8 mice exhibit 3,200-4,600 pmol of Abeta42 per g brain at age 6 months, with an excess of Abeta42 over Abeta40. High level production of the pathogenic Abeta42 form of Abeta peptide was associated with an early impairment in TgCRND8 mice in acquisition and learning reversal in the reference memory version of the Morris water maze, present by 3 months of age. Notably, learning impairment in young mice was offset by immunization against Abeta42 (Janus, C., Pearson, J., McLaurin, J., Mathews, P. M., Jiang, Y., Schmidt, S. D., Chishti, M. A., Horne, P., Heslin, D., French, J., Mount, H. T. J., Nixon, R. A., Mercken, M., Bergeron, C., Fraser, P. E., St. George-Hyslop, P., and Westaway, D. (2000) Nature 408, 979-982). Amyloid deposition in TgCRND8 mice was enhanced by the expression of presenilin 1 transgenes including familial Alzheimer's disease mutations; for mice also expressing a M146L+L286V presenilin 1 transgene, amyloid deposits were apparent by 1 month of age. The Tg mice described here suggest a potential to investigate aspects of Alzheimer's disease pathogenesis, prophylaxis, and therapy within short time frames.
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Affiliation(s)
- M A Chishti
- Centre for Research in Neurodegenerative Diseases, the Department of Laboratory Medicine, Division of Neurology, University Health Network, University of Toronto, Toronto, Ontario M5S 3H2, Canada
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1049
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Sleegers K, Van Duijn C. Alzheimer's Disease: Genes, Pathogenesis and Risk Prediction. Public Health Genomics 2001; 4:197-203. [PMID: 12107347 DOI: 10.1159/000064193] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
With the aging of western society the contribution to morbidity of diseases of the elderly, such as dementia, will increase exponentially. Thorough preventative and curative strategies are needed to constrain the increasing prevalence of these disabling diseases. Better understanding of the pathogenesis of disease will enable development of therapy, prevention and the identification of high-risk groups in the population. Here, we review the genetic epidemiology of Alzheimer's disease, the most common cause of dementia in the western world. The search for genetic risk factors, though far from completed, has been of major importance for understanding the pathogenesis of Alzheimer's disease. Although effective therapy is still awaited, these findings have led to new avenues for the development of drugs. Copyright 2002 S. Karger AG, Basel
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Affiliation(s)
- K. Sleegers
- Department of Epidemiology and Biostatistics, Erasmus Medical Centre Rotterdam, The Netherlands
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1050
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Abstract
Transgenic mice developing beta-amyloid (Abeta) plaques are advancing experimental treatment strategies for Alzheimer's disease. The metal chelator, clioquinol, is reported by Cherny et al. (2001) to reduce Abeta plaques, presumably by chelation of Abeta-associated zinc and copper. This and other recent Abeta-modulating treatment approaches are discussed.
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Affiliation(s)
- G K Gouras
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY 10021, USA
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