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Puzzo D, Sapienza S, Arancio O, Palmeri A. Role of phosphodiesterase 5 in synaptic plasticity and memory. Neuropsychiatr Dis Treat 2008; 4:371-87. [PMID: 18728748 PMCID: PMC2518390 DOI: 10.2147/ndt.s2447] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Phosphodiesterases (PDEs) are enzymes that break down the phosphodiesteric bond of the cyclic nucleotides, cAMP and cGMP, second messengers that regulate many biological processes. PDEs participate in the regulation of signal transduction by means of a fine regulation of cyclic nucleotides so that the response to cell stimuli is both specific and activates the correct third messengers. Several PDE inhibitors have been developed and used as therapeutic agents because they increase cyclic nucleotide levels by blocking the PDE function. In particular, sildenafil, an inhibitor of PDE5, has been mainly used in the treatment of erectile dysfunction but is now also utilized against pulmonary hypertension. This review examines the physiological role of PDE5 in synaptic plasticity and memory and the use of PDE5 inhibitors as possible therapeutic agents against disorders of the central nervous system (CNS).
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Affiliation(s)
- Daniela Puzzo
- Dept of Physiological Sciences, University of Catania Catania, Italy.
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52
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Tsunekawa H, Noda Y, Mouri A, Yoneda F, Nabeshima T. Synergistic effects of selegiline and donepezil on cognitive impairment induced by amyloid beta (25-35). Behav Brain Res 2008; 190:224-32. [PMID: 18420288 DOI: 10.1016/j.bbr.2008.03.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2007] [Revised: 02/28/2008] [Accepted: 03/03/2008] [Indexed: 11/27/2022]
Abstract
Selegiline, an irreversible inhibitor of monoamine oxidase B used in the treatment of Parkinson's disease, has been demonstrated to have a potential cognition-improving effect in patients with Alzheimer's disease (AD) undergoing treatment with an acetylcholinesterase inhibitor donepezil. To confirm such clinical events, we investigated whether co-administration of donepezil with selegiline had a synergistic cognition-improving effect in an animal model of AD. Intracerebroventricular injection of amyloid beta protein fragment 25-35 [Abeta(25-35)] induced impairment of learning and memory in a Y-maze, novel object recognition and contextual fear conditioning tests. Either donepezil or selegiline alone improved the cognitive impairments in the Y-maze and conditioned fear learning tasks in Abeta(25-35)-injected mice, whereas donepezil, but not selegiline, failed to improve the impairment in a novel object recognition task. Co-administration of donepezil with selegiline, at doses that do not exert efficacy individually, significantly improved the deficits in all three tests, indicating a synergistic cognition-improving effect. These alleviating effects were antagonized by pretreatment with a muscarinic receptor antagonist scopolamine and a dopamine receptor antagonist haloperidol. These results suggest that selegiline potentiates the effect of donepezil on the cognitive impairment, and that the synergistic effect may be mediated through both the cholinergic and dopaminergic systems.
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Affiliation(s)
- Hiroko Tsunekawa
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya, Aichi 466-8560, Japan
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53
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Alkam T, Nitta A, Mizoguchi H, Saito K, Seshima M, Itoh A, Yamada K, Nabeshima T. Restraining tumor necrosis factor-alpha by thalidomide prevents the amyloid beta-induced impairment of recognition memory in mice. Behav Brain Res 2007; 189:100-6. [PMID: 18325608 DOI: 10.1016/j.bbr.2007.12.014] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Accepted: 12/17/2007] [Indexed: 12/12/2022]
Abstract
No effective remedy has currently been realized to prevent the cognitive impairments of Alzheimer's disease (AD). The interruption of the toxic pathways of amyloid beta peptide (Abeta) still remains promising for the treatment. The involvement of tumor necrosis factor-alpha (TNF-alpha) in the toxicity of Abeta(1-40) in recent reports provide a fresh target for the interruption. In the current study, we evaluated the feasibility of a strategy that target TNF-alpha to prevent the impairment of memory induced by Abeta. The i.c.v-injection of Abeta(25-35) increased the hippocampal mRNA expression of both TNF-alpha and inducible nitric oxide synthase (iNOS), of which the former was stronger. The knock-out of TNF-alpha (TNF-alpha (-/-)) in mouse prevented the increase of iNOS mRNA induced by Abeta(25-35). Not only the inhibition of iNOS activity but also TNF-alpha (-/-) prevented the nitration of proteins in the hippocampus and the impairment of recognition memory in mice induced by Abeta(25-35). Daily treatment with thalidomide (20 mg/kg), a preferential degrader of TNF-alpha mRNA, or i.c.v.-injection of an anti-TNF-alpha antibody (10 etag/mouse) prevented the nitration of proteins in the hippocampus and the impairment of recognition memory induced by Abeta(25-35) or Abeta(1-40) in mice. These results suggested the practicability of targeting TNF-alpha as a preventive strategy against Abeta-mediated cognitive impairments.
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Affiliation(s)
- Tursun Alkam
- Department of Neuropsychopharmacology & Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan
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54
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Alkam T, Nitta A, Mizoguchi H, Itoh A, Nabeshima T. A natural scavenger of peroxynitrites, rosmarinic acid, protects against impairment of memory induced by Abeta(25-35). Behav Brain Res 2007; 180:139-45. [PMID: 17420060 DOI: 10.1016/j.bbr.2007.03.001] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Revised: 02/26/2007] [Accepted: 03/02/2007] [Indexed: 11/26/2022]
Abstract
Peroxynitrite (ONOO(-))-mediated damage is regarded to be responsible for the cognitive dysfunction induced by amyloid beta protein (Abeta) in Alzheimer's disease (AD). In the present study, we examined the protective effects of rosmarinic acid (RA), a natural scavenger of ONOO(-), on the memory impairment in a mouse model induced by acute i.c.v. injection of Abeta(25-35). Mice daily received i.p. several doses of RA after the injection of Abeta(25-35). RA prevented the memory impairments induced by Abeta(25-35) in the Y maze test and novel object recognition task. RA, at the effective lowest dose (0.25mg/kg), prevented Abeta(25-35)-induced nitration of proteins, an indirect indicator of ONOO(-) damage, in the hippocampus. At this dose, RA also prevented nitration of proteins and impairment of recognition memory induced by ONOO(-)-i.c.v.-injection. Co-injection of the non-memory-impairing dose of ONOO(-) with Abeta(25-35) blocked the protective effects of RA (0.25mg/kg). These results demonstrated that the memory protective effects of RA in the neurotoxicity of Abeta(25-35) is due to its scavenging of ONOO(-), and that daily consumption of RA may protect against memory impairments observed in AD.
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Affiliation(s)
- Tursun Alkam
- Department of Neuropsychopharmacology & Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan
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55
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Medeiros R, Prediger RDS, Passos GF, Pandolfo P, Duarte FS, Franco JL, Dafre AL, Di Giunta G, Figueiredo CP, Takahashi RN, Campos MM, Calixto JB. Connecting TNF-alpha signaling pathways to iNOS expression in a mouse model of Alzheimer's disease: relevance for the behavioral and synaptic deficits induced by amyloid beta protein. J Neurosci 2007; 27:5394-404. [PMID: 17507561 PMCID: PMC6672347 DOI: 10.1523/jneurosci.5047-06.2007] [Citation(s) in RCA: 218] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Increased brain deposition of amyloid beta protein (Abeta) and cognitive deficits are classical signals of Alzheimer's disease (AD) that have been highly associated with inflammatory alterations. The present work was designed to determine the correlation between tumor necrosis factor-alpha (TNF-alpha)-related signaling pathways and inducible nitric oxide synthase (iNOS) expression in a mouse model of AD, by means of both in vivo and in vitro approaches. The intracerebroventricular injection of Abeta(1-40) in mice resulted in marked deficits of learning and memory, according to assessment in the water maze paradigm. This cognition impairment seems to be related to synapse dysfunction and glial cell activation. The pharmacological blockage of either TNF-alpha or iNOS reduced the cognitive deficit evoked by Abeta(1-40) in mice. Similar results were obtained in TNF-alpha receptor 1 and iNOS knock-out mice. Abeta(1-40) administration induced an increase in TNF-alpha expression and oxidative alterations in prefrontal cortex and hippocampus. Likewise, Abeta(1-40) led to activation of both JNK (c-Jun-NH2-terminal kinase)/c-Jun and nuclear factor-kappaB, resulting in iNOS upregulation in both brain structures. The anti-TNF-alpha antibody reduced all of the molecular and biochemical alterations promoted by Abeta(1-40). These results provide new insights in mouse models of AD, revealing TNF-alpha and iNOS as central mediators of Abeta action. These pathways might be targeted for AD drug development.
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Affiliation(s)
| | | | | | | | | | | | - Alcir L. Dafre
- Ciências Fisiológicas, Centro de Ciências Biológicas, and
| | - Gabriella Di Giunta
- Departamento de Anatomia Patológica, Hospital Universitário–Universidade Federal de Santa Catarina, 88049-900, Florianópolis, Santa Catarina, Brazil, and
| | - Cláudia P. Figueiredo
- Departamento de Anatomia Patológica, Hospital Universitário–Universidade Federal de Santa Catarina, 88049-900, Florianópolis, Santa Catarina, Brazil, and
| | | | - Maria M. Campos
- Faculdade de Odontologia, Pontifícia Universidade Católica do Rio Grande do Sul 90619-900, Rio Grande do Sul, Brazil
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56
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Puzzo D, Palmeri A, Arancio O. Involvement of the nitric oxide pathway in synaptic dysfunction following amyloid elevation in Alzheimer's disease. Rev Neurosci 2007; 17:497-523. [PMID: 17180876 DOI: 10.1515/revneuro.2006.17.5.497] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Amyloid-beta (Abeta), a peptide thought to play a crucial role in Alzheimer's disease (AD), has attracted scientific interest with the aim of characterizing the mechanisms by which it is involved in AD pathogenesis. Abeta has been found to markedly impair hippocampal long-term potentiation (LTP), a widely studied cellular model of synaptic plasticity that is thought to underlie learning and memory. The overall purpose of this review is to define the role of the nitric oxide (NO)/cGMP/cAMP-regulatory element binding (CREB) pathway in beta-amyloid-induced changes of basal neurotransmission and synaptic plasticity in the hippocampus, a structure within the temporal lobe of the brain critical for memory storage.
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Affiliation(s)
- Daniela Puzzo
- Department of Pathology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA.
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57
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Nagai T, Ito M, Nakamichi N, Mizoguchi H, Kamei H, Fukakusa A, Nabeshima T, Takuma K, Yamada K. The rewards of nicotine: regulation by tissue plasminogen activator-plasmin system through protease activated receptor-1. J Neurosci 2006; 26:12374-83. [PMID: 17122062 PMCID: PMC6675418 DOI: 10.1523/jneurosci.3139-06.2006] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Nicotine, a primary component of tobacco, is one of the most abused drugs worldwide. Approximately four million people die each year because of diseases associated with tobacco smoking. Mesolimbic dopaminergic neurons mediate the rewarding effects of abused drugs, including nicotine. Here we show that the tissue plasminogen activator (tPA)-plasmin system regulates nicotine-induced reward and dopamine release by activating protease activated receptor-1 (PAR1). In vivo microdialysis revealed that microinjection of either tPA or plasmin into the nucleus accumbens (NAc) significantly potentiated whereas plasminogen activator inhibitor-1 reduced the nicotine-induced dopamine release in the NAc in a dose-dependent manner. Nicotine-induced dopamine release was markedly diminished in tPA-deficient (tPA-/-) mice, and the defect of dopamine release in tPA-/- mice was restored by microinjection of either exogenous tPA or plasmin into the NAc. Nicotine increased tPA protein levels and promoted the release of tPA into the extracellular space in the NAc. Immunohistochemistry revealed that PAR1 immunoreactivity was localized to the nerve terminals positive for tyrosine hydroxylase in the NAc. Furthermore, we demonstrated that plasmin activated PAR1 and that nicotine-induced place preference and dopamine release were diminished in PAR1-deficient (PAR1-/-) mice. Targeting the tPA-plasmin-PAR1 system would provide new therapeutic approaches to the treatment of nicotine dependence.
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MESH Headings
- Acetylcholine/metabolism
- Analysis of Variance
- Animals
- Brain/cytology
- Brain/drug effects
- Brain/metabolism
- Cells, Cultured
- Dopamine/metabolism
- Dopamine Antagonists/pharmacology
- Dose-Response Relationship, Drug
- Drug Interactions
- Electrophoresis, Polyacrylamide Gel/methods
- Embryo, Mammalian
- Guanosine 5'-O-(3-Thiotriphosphate)/pharmacokinetics
- Immunohistochemistry/methods
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred ICR
- Mice, Knockout
- Neurons/drug effects
- Neurons/metabolism
- Nicotine/administration & dosage
- Nicotinic Agonists/administration & dosage
- Radioligand Assay/methods
- Receptor, PAR-1/deficiency
- Receptor, PAR-1/physiology
- Reward
- Statistics, Nonparametric
- Tissue Plasminogen Activator/genetics
- Tissue Plasminogen Activator/pharmacology
- Tissue Plasminogen Activator/physiology
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Affiliation(s)
- Taku Nagai
- Laboratory of Neuropsychopharmacology, Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan
| | - Mina Ito
- Laboratory of Neuropsychopharmacology, Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
| | - Noritaka Nakamichi
- Laboratory of Neuropsychopharmacology, Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
| | - Hiroyuki Mizoguchi
- Laboratory of Neuropsychopharmacology, Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
| | - Hiroyuki Kamei
- Laboratory of Neuropsychopharmacology, Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
| | - Ayumi Fukakusa
- Laboratory of Neuropsychopharmacology, Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
| | - Toshitaka Nabeshima
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan
| | - Kazuhiro Takuma
- Laboratory of Neuropsychopharmacology, Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
| | - Kiyofumi Yamada
- Laboratory of Neuropsychopharmacology, Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
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58
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Ito M, Nagai T, Kamei H, Nakamichi N, Nabeshima T, Takuma K, Yamada K. Involvement of Tissue Plasminogen Activator-Plasmin System in Depolarization-Evoked Dopamine Release in the Nucleus Accumbens of Mice. Mol Pharmacol 2006; 70:1720-5. [PMID: 16908600 DOI: 10.1124/mol.106.022467] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tissue plasminogen activator (tPA), a serine protease, catalyzes the conversion of plasminogen to plasmin. In the present study, we investigated the role of the tPA-plasmin system in depolarization-evoked dopamine (DA) and acetylcholine (ACh) release in the nucleus accumbens (NAc) and hippocampus, respectively, of mice, by using in vivo microdialysis. Microinjection of either tPA or plasmin significantly potentiated 40 mM KCl-induced DA release without affecting basal DA levels. In contrast, plasminogen activator inhibitor-1 dose-dependently reduced 60 mM KCl-induced DA release. The 60 mM KCl-evoked DA release in the NAc was markedly diminished in tPA-deficient (tPA-/-) mice compared with wild-type mice, although basal DA levels did not differ between the two groups. Microinjections of either exogenous tPA (100 ng) or plasmin (100 ng) into the NAc of tPA-/-mice restored 60 mM KCl-induced DA release, as observed in wild-type mice. In contrast, there was no difference in either basal or 60 mM KCl-induced ACh release in the hippocampus between wild-type and tPA-/-mice. Our findings suggest that the tPA-plasmin system is involved in the regulation of depolarization-evoked DA release in the NAc.
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Affiliation(s)
- Mina Ito
- Laboratory of Neuropsychopharmacology, Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
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59
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Zhang YJ, Xu YF, Liu YH, Yin J, Li HL, Wang Q, Wang JZ. Peroxynitrite induces Alzheimer-like tau modifications and accumulation in rat brain and its underlying mechanisms. FASEB J 2006; 20:1431-42. [PMID: 16816118 DOI: 10.1096/fj.05-5223com] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To investigate the upstream effector that led to tau hyperphosphorylation, nitration, and accumulation as seen in Alzheimer's disease brain, and the underlying mechanisms, we bilaterally injected SIN-1, a recognized peroxynitrite donor, into the hippocampus of rat brain. We observed that the level of nitrated and hyperphosphorylated tau was markedly increased in rat hippocampus 24 h after drug administration, and these alterations were prevented by preinjection of uric acid, a natural scavenger of peroxynitrite. Concomitantly, we detected a significant activation in glycogen synthase kinase-3beta (GSK-3beta) and p38 MAPKs, including p38alpha, p38beta, and p38delta, but no obvious change was measured in the activity of p38gamma, ERK, and c-Jun amino-terminal kinase (JNK). Both nitrated tau and hyperphosphorylated tau were aggregated in the hippocampus, in which the activity of 20S proteasome was significantly arrested in SIN-1-injected rats. Further studies demonstrated that the hyperphosphorylated tau was degraded as efficiently as normal tau by 20S proteasome, but the nitrated tau with an unorderly secondary structure became more resistant to the proteolysis. These results provide the first in vivo evidence showing that peroxynitrite simultaneously induces tau hyperphosphorylation, nitration, and accumulation, and that activation of GSK-3beta, p38alpha, p38beta, p38delta isoforms and the inhibition of proteasome activity are respectively responsible for the peroxynitrite-induced tau hyperphosphorylation and accumulation. Our findings reveal a common upstream stimulator and a potential therapeutic target for Alzheimer-like neurodegeneration.
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Affiliation(s)
- Yong-Jie Zhang
- Pathophysiology Department, Key Laboratory of Neurological Disease of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China
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60
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Yamada K, Takayanagi M, Kamei H, Nagai T, Dohniwa M, Kobayashi K, Yoshida S, Ohhara T, Takuma K, Nabeshima T. Effects of memantine and donepezil on amyloid beta-induced memory impairment in a delayed-matching to position task in rats. Behav Brain Res 2006; 162:191-9. [PMID: 15904984 DOI: 10.1016/j.bbr.2005.02.036] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 02/25/2005] [Accepted: 02/25/2005] [Indexed: 11/26/2022]
Abstract
We investigated the effects of memantine and donepezil on amyloid beta (Abeta)-induced memory impairment in rats, which was assessed by a delayed-matching to position (DMPT) paradigm in three-lever operant chambers. Aggregated Abeta1-40 was microinjected bilaterally (1 nmol/side) into both CA1 and CA3 subfields of the hippocampus in rats that had previously performed the DMTP task. Memantine (20 mg/(kg day), s.c.) was continuously infused by an osmotic minipump for 4 weeks from 3 days before the microinjection of Abeta. Donepezil (2.5 mg/kg, p.o.) was administered 60 min before the DMTP test session. Bilateral microinjections of Abeta1-40 into the hippocampus resulted in a delayed, but persistent impairment of DMTP performance, which appeared more than 50 days after the injection. Memantine prevented the development of Abeta-induced memory impairment, while donepezil symptomatically alleviated the deficits. Because of a ceiling effect, the combination of donepezil with memantine failed to produce any additive or synergic effects. These results support the clinical data showing that memantine and donepezil are effective for the treatment of Alzheimer's disease. Moreover, it is suggested that memantine is effective for preventing Abeta-induced short-term memory impairment.
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Affiliation(s)
- Kiyofumi Yamada
- Laboratory of Neuropsychopharmacology, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
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61
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Puzzo D, Vitolo O, Trinchese F, Jacob JP, Palmeri A, Arancio O. Amyloid-beta peptide inhibits activation of the nitric oxide/cGMP/cAMP-responsive element-binding protein pathway during hippocampal synaptic plasticity. J Neurosci 2006; 25:6887-97. [PMID: 16033898 PMCID: PMC6725343 DOI: 10.1523/jneurosci.5291-04.2005] [Citation(s) in RCA: 190] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Amyloid-beta (Abeta), a peptide thought to play a crucial role in Alzheimer's disease (AD), has many targets that, in turn, activate different second-messenger cascades. Interestingly, Abeta has been found to markedly impair hippocampal long-term potentiation (LTP). To identify a new pathway that might be responsible for such impairment, we analyzed the role of the nitric oxide (NO)/soluble guanylyl cyclase (sGC)/cGMP/cGMP-dependent protein kinase (cGK)/cAMP-responsive element-binding protein (CREB) cascade because of its involvement in LTP. The use of the NO donor 2-(N,N-dethylamino)-diazenolate-2-oxide diethylammonium salt (DEA/NO), the sGC stimulator 3-(4-amino-5-cyclopropylpyrimidine-2-yl)-1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridine, or the cGMP-analogs 8-bromo-cGMP and 8-(4-chlorophenylthio)-cGMP reversed the Abeta-induced impairment of CA1-LTP through cGK activation. Furthermore, these compounds reestablished the enhancement of CREB phosphorylation occurring during LTP in slices exposed to Abeta. We also found that Abeta blocks the increase in cGMP immunoreactivity occurring immediately after LTP and that DEA/NO counteracts the effect of Abeta. These results strongly suggest that, when modulating hippocampal synaptic plasticity, Abeta downregulates the NO/cGMP/cGK/CREB pathway; thus, enhancement of the NO/cGMP signaling may provide a novel approach to the treatment of AD and other neurodegenerative diseases with elevated production of Abeta.
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Affiliation(s)
- Daniela Puzzo
- Department of Psychiatry, New York University School of Medicine, New York, New York 10016, USA
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62
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Hervás-Aguilar A, Puebla-Jiménez L, Burgos-Ramos E, Aguado-Llera D, Arilla-Ferreiro E. Effects of single and continuous administration of amyloid beta-peptide (25-35) on adenylyl cyclase activity and the somatostatinergic system in the rat frontal and parietal cortex. Neuroscience 2005; 135:181-90. [PMID: 16084649 DOI: 10.1016/j.neuroscience.2005.02.017] [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] [Received: 05/10/2004] [Revised: 02/07/2005] [Accepted: 02/12/2005] [Indexed: 11/26/2022]
Abstract
It is unknown whether the amyloid beta-peptide (Abeta), a principal component found in extracellular neuritic plaques in the brain of patients with Alzheimer's disease (AD), is capable of altering adenylyl cyclase (AC) activity and the somatostatin (SRIF) receptor-effector system in the cerebral cortex of the patients. Therefore, the objective of this study was to investigate the effect of the beta fragment, beta (25-35), on AC activity and the somatostatinergic system in the rat frontoparietal cortex. A single dose of beta (25-35) (10microg) injected intracerebroventricularly significantly decreased the density of SRIF receptors (27.4%) and increased their affinity (32.2%) in the frontoparietal cortex. The inhibitory effect of SRIF on basal and forskolin (FK)-stimulated AC activity was significantly lower in the beta (25-35)-treated rats when compared with controls. beta (25-35) did not modify Gialpha1, Gialpha2 nor Gialpha3 levels in membranes from the frontoparietal cortex. Continuous infusion of the peptide induced a decrease in the SRIF receptor density in this brain area to a similar extent as that observed 14 days after the single administration of the peptide. Likewise, this treatment decreased the SRIF receptor density in the frontal cortex (15.3%) and parietal cortex (27.2%). This effect was accompanied by a decrease in the SRIF-mediated inhibition of FK-stimulated AC activity (from 41.6% to 25.6%) in the frontal cortex as well by a decrease in basal AC activity (from 36.9% to 31.6%) and FK-stimulated AC activity (from 35.6% to 27.1%) in the parietal cortex. Continuous infusion of Abeta (25-35) had no effect on Gialpha1, Gialpha2 or Gialpha3 levels in membranes from frontal and parietal cortex. However, this treatment caused a decrease in SRIF-like immunoreactivity content in the parietal (38.9%) and frontal (20.4%) cortex. These results suggest that Abeta might be involved in the alterations of somatostatinergic system reported in AD.
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Affiliation(s)
- A Hervás-Aguilar
- Grupo de Neurobioquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Ctra. Madrid-Barcelona km 33,6, Universidad de Alcalá, E-28871, Alcalá de Henares, Madrid, Spain
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63
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Stepanichev MY, Moiseeva YV, Lazareva NA, Gulyaeva NV. Studies of the effects of fragment (25?35) of beta-amyloid peptide on the behavior of rats in a radial maze. ACTA ACUST UNITED AC 2005; 35:511-8. [PMID: 16033199 DOI: 10.1007/s11055-005-0086-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Decreases in cognitive functions, particularly long-term (episodic) and working memory, are among the earliest prognostic signs of Alzheimer's disease. The toxicity of beta-amyloid peptide is regarded as a major cause of neurodegeneration and cognitive impairment in this disease. The present report describes studies of the effects of intracerebroventricular administration of beta-amyloid peptide (25-35) (Abeta(25-35)) on the reproduction of a previously assimilated habit consisting of finding food in an eight-arm radial maze in rats. Abeta(25-35) was given bilaterally at doses of 15 and 30 nmol/animal seven days after preliminary training. Testing was performed 60 days after peptide administration. The results showed that Abeta(25-35) impaired working memory in rats without having any significant effect on the retention of responses. We were unable to demonstrate any relationship between memory impairment and the dose of peptide given. These data provide evidence of the ability of Abeta(25-35) to produce greater degradation of working memory function than long-term memory function.
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Affiliation(s)
- M Yu Stepanichev
- Laboratory for the Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow.
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64
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Jhoo JH, Kim HC, Nabeshima T, Yamada K, Shin EJ, Jhoo WK, Kim W, Kang KS, Jo SA, Woo JI. Beta-amyloid (1-42)-induced learning and memory deficits in mice: involvement of oxidative burdens in the hippocampus and cerebral cortex. Behav Brain Res 2005; 155:185-96. [PMID: 15364477 DOI: 10.1016/j.bbr.2004.04.012] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2004] [Revised: 04/13/2004] [Accepted: 04/13/2004] [Indexed: 10/26/2022]
Abstract
We have demonstrated that oxidative stress is involved, at least in part, in beta-amyloid protein (Abeta)-induced neurotoxicity in vivo [Eur. J. Neurosci. 1999;11:83-90; Neuroscience 2003;119:399-419]. However, mechanistic links between oxidative stress and memory loss in response to Abeta remain elusive. In the present study, we examined whether oxidative stress contributes to the memory deficits induced by intracerebroventricular injection of Abeta (1-42) in mice. Abeta (1-42)-induced memory impairments were observed, as measured by the water maze and passive avoidance tests, although these impairments were not found in Abeta (40-1)-treated mice. Treatment with antioxidant alpha-tocopherol significantly prevented memory impairment induced by Abeta (1-42). Increased activities of the cytosolic Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and mitochondrial Mn-superoxide dismutase (Mn-SOD) were observed in the hippocampus and cerebral cortex of Abeta (1-42)-treated animals, as compared with Abeta (40-1)-treated mice. The induction of Cu,Zn-SOD was more pronounced than that of Mn-SOD after Abeta (1-42) insult. However, the concomitant induction of glutathione peroxidase (GPX) in response to significant increases in SOD activity was not seen in animals treated with Abeta (1-42). Furthermore, glutathione reductase (GRX) activity was only increased at 2h after Abeta (1-42) injection. Production of malondialdehyde (lipid peroxidation) and protein carbonyl (protein oxidation) remained elevated at 10 days post-Abeta (1-42), but the antioxidant alpha-tocopherol significantly prevented these oxidative stresses. Therefore, our results suggest that the oxidative stress contributes to the Abeta (1-42)-induced learning and memory deficits in mice.
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Affiliation(s)
- Jin Hyeong Jhoo
- Department of Psychiatry, Pundang Jesaeng Hospital, Daejin Medical Center, Seongnam, South Korea
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65
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Urani A, Romieu P, Roman FJ, Yamada K, Noda Y, Kamei H, Manh Tran H, Nagai T, Nabeshima T, Maurice T. Enhanced antidepressant efficacy of sigma1 receptor agonists in rats after chronic intracerebroventricular infusion of beta-amyloid-(1-40) protein. Eur J Pharmacol 2004; 486:151-61. [PMID: 14975704 DOI: 10.1016/j.ejphar.2003.12.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2003] [Revised: 12/04/2003] [Accepted: 12/12/2003] [Indexed: 11/23/2022]
Abstract
Treatment of depressive symptoms in patients suffering from neurodegenerative disorders remains a challenging issue, since few available antidepressants present an adequate efficacy during pathological aging. Previous reports suggested that selective sigma(1) receptor agonists might constitute putative candidates. We here examined the pharmacological efficacy of igmesine and (+)-SKF-10,047 and the sigma(1) receptor-related neuroactive steroid dehydroepiandrosterone sulfate, in rats infused intracerebroventricularly during 14 days with the beta-amyloid-(1-40) protein and then submitted to the conditioned fear stress test. Igmesine and (+)-SKF-10,047 significantly reduced the stress-induced motor suppression at 30 and 6 mg/kg, respectively, in beta-amyloid-(40-1)-treated control rats. Active doses were decreased, to 10 and 3 mg/kg, respectively, in beta-amyloid-(1-40)-treated animals. The dehydroepiandrosterone sulfate effect was also facilitated, both in dose (10 vs. 30 mg/kg) and intensity, in beta-amyloid-(1-40)-treated rats. Neurosteroid levels were measured in several brain structures after beta-amyloid infusion, in basal and stress conditions. Progesterone levels, both under basal and stress-induced conditions, were decreased in the hippocampus and cortex of beta-amyloid-(1-40)-treated rats. The levels in pregnenolone, dehydroepiandrosterone and their sulfate esters appeared less affected by the beta-amyloid infusion. The sigma(1) receptor agonist efficacy is known to be inversely correlated to brain progesterone levels, synthesized mainly by neurons that are mainly affected by the beta-amyloid toxicity. The present study suggests that sigma(1) receptor agonists, due to their enhanced efficacy in a nontransgenic animal model, may alleviate Alzheimer's disease-associated depressive symptoms.
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Affiliation(s)
- Alexandre Urani
- INSERM U.336, Behavioural Neuropharmacology Group, Institut de Biologie, 4, bvd Henri IV, 34060 Montpellier, France
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66
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Kim HC, Yamada K, Nitta A, Olariu A, Tran MH, Mizuno M, Nakajima A, Nagai T, Kamei H, Jhoo WK, Im DH, Shin EJ, Hjelle OP, Ottersen OP, Park SC, Kato K, Mirault ME, Nabeshima T. Immunocytochemical evidence that amyloid beta (1-42) impairs endogenous antioxidant systems in vivo. Neuroscience 2003; 119:399-419. [PMID: 12770555 DOI: 10.1016/s0306-4522(02)00993-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Amyloid beta, the major constituent of the senile plaques in the brains of patients with Alzheimer's disease, is cytotoxic to neurons and has a central role in the pathogenesis of the disease. We have previously demonstrated that potent antioxidants idebenone and alpha-tocopherol prevent learning and memory impairment in rats which received a continuous intracerebroventricular infusion of amyloid beta, suggesting a role for oxidative stress in amyloid beta-induced learning and memory impairment. To test the hypothesis, in the present study, we investigated alterations in the immunoreactivity of endogenous antioxidant systems such as mitochondrial Mn-superoxide dismutase, glutathione, glutathione peroxidase and glutathione-S-transferase following the continuous intracerebroventricular infusion of amyloid beta for 2 weeks. The infusion of amyloid beta (1-42) resulted in a significant reduction of the immunoreactivity of these antioxidant substances in such brain areas as the hippocampus, parietal cortex, piriform cortex, substantia nigra and thalamus although the same treatment with amyloid beta (40-1) had little effect. The alterations induced by amyloid beta (1-42) were not uniform, but rather specific for each immunoreactive substance in a brain region-dependent manner. These results demonstrate a cytological effect of oxidative stress induced by amyloid beta (1-42) infusion. Furthermore, our findings may indicate a heterogeneous susceptibility to the oxidative stress produced by amyloid beta.
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Affiliation(s)
- H-C Kim
- Department of Pharmacy, College of Pharmacy, Kangwon National University, Korea Institute of Drug Abuse, Chunchon 200-701, South Korea
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67
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Stepanichev MY, Moiseeva YV, Lazareva NA, Onufriev MV, Gulyaeva NV. Single intracerebroventricular administration of amyloid-beta (25-35) peptide induces impairment in short-term rather than long-term memory in rats. Brain Res Bull 2003; 61:197-205. [PMID: 12832007 DOI: 10.1016/s0361-9230(03)00118-7] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ample experimental evidence indicates that intracerebral injection or infusion of amyloid-beta peptides (Abeta) to rodents induces learning and memory impairments as well as neurodegeneration in brain areas related to cognitive function. In the present study, we assessed the effects of a single intracerebroventricular (i.c.v.) injection of aggregated Abeta fragment (25-35) at a dose of 15nmol/rat on short-term and long-term memory in rats during the 6-month post-surgery period. The results demonstrate that Abeta(25-35)-induced memory impairments in spontaneous alternation behavior in a Y-maze at 17, 36, and 180 days after the surgery as well as in a social recognition task 110 days post-surgery. Abeta(25-35) also impaired spatial memory in an 8-arm radial maze, but did not influence performance of the step-down passive avoidance task. These results suggest that Abeta(25-35) preferably induces impairments of spatial and non-spatial short-term (working) memory rather than long-term memory in rats.
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Affiliation(s)
- M Yu Stepanichev
- Department of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 5a Butlerov Str., Moscow 117485, Russia
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68
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Brown GC, Bal-Price A. Inflammatory neurodegeneration mediated by nitric oxide, glutamate, and mitochondria. Mol Neurobiol 2003; 27:325-55. [PMID: 12845153 DOI: 10.1385/mn:27:3:325] [Citation(s) in RCA: 328] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2002] [Accepted: 12/27/2002] [Indexed: 11/11/2022]
Abstract
In inflammatory, infectious, ischemic, and neurodegenerative pathologies of the central nervous system (CNS) glia become "activated" by inflammatory mediators, and express new proteins such as the inducible isoform of nitric oxide synthase (iNOS). Although these activated glia have benefi- cial roles, in vitro they potently kill cocultured neurons, and there is increasing evidence that they contribute to pathology in vivo. Nitric oxide (NO) from iNOS appears to be a key mediator of such glial-induced neuronal death. The high sensitivity of neurons to NO is partly due to NO causing inhibition of respiration, rapid glutamate release from both astrocytes and neurons, and subsequent excitotoxic death of the neurons. NO is a potent inhibitor of mitochondrial respiration, due to reversible binding of NO to cytochrome oxidase in competition with oxygen, resulting in inhibition of energy production and sensitization to hypoxia. Activated astrocytes or microglia cause a potent inhibition of respiration in cocultured neurons due to glial NO inhibiting cytochrome oxidase within the neurons, resulting in ATP depletion and glutamate release. In some conditions, glutamate- induced neuronal death can itself be mediated by N-methyl-D-aspartate (NMDA)-receptor activation of the neuronal isoform of NO synthase (nNOS) causing mitochondrial damage. In addition NO can be converted to a number of reactive derivatives such as peroxynitrite, NO2, N2O3, and S-nitrosothiols that can kill cells in part by inhibiting mitochondrial respiration or activation of mitochondrial permeability transition, triggering neuronal apoptosis or necrosis.
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Affiliation(s)
- Guy C Brown
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK.
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69
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Tran MH, Yamada K, Nakajima A, Mizuno M, He J, Kamei H, Nabeshima T. Tyrosine nitration of a synaptic protein synaptophysin contributes to amyloid beta-peptide-induced cholinergic dysfunction. Mol Psychiatry 2003; 8:407-12. [PMID: 12740598 DOI: 10.1038/sj.mp.4001240] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Amyloid beta (Abeta) is a critical factor involved in the pathogenesis of Alzheimer's disease (AD). We have previously demonstrated that continuous intracerebroventricular infusion of Abeta1-40 induced a time-dependent expression of the inducible nitric oxide (NO) synthase (iNOS) and an overproduction of NO in the rat hippocampus. The pathophysiological significance of the overproduction of NO on brain function was manifested by an impairment of nicotine-evoked acetylcholine(ACh) release and memory deficits.(4) Molecular mechanisms by which NO participates in the Abeta-induced brain dysfunction, however, remain to be determined. Here we show that chronic Abeta1-40 infusion caused a robust peroxynitrite formation and subsequent tyrosine nitration of proteins in the hippocampus. Immunoprecipitation and Western blot analyses further revealed that synaptophysin, a synaptic protein, was a main target of tyrosine nitration. Chronic infusion of Abeta1-40 resulted in an impairment of nicotine-evoked ACh release as analyzed by microdialysis. Daily treatment with the iNOS inhibitor aminoguanidine (AG) or the peroxynitrite scavenger uric acid (UA) prevented the tyrosine nitration of synaptophysin as well as the impairment of nicotine-evoked ACh release induced by Abeta. Our findings suggest that the tyrosine nitration of synaptophysin is related to Abeta-induced impairment of ACh release.
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Affiliation(s)
- M H Tran
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya, Japan.
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70
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Melo JB, Agostinho P, Oliveira CR. Involvement of oxidative stress in the enhancement of acetylcholinesterase activity induced by amyloid beta-peptide. Neurosci Res 2003; 45:117-27. [PMID: 12507730 DOI: 10.1016/s0168-0102(02)00201-8] [Citation(s) in RCA: 201] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Acetylcholinesterase (AChE) activity is increased within and around amyloid plaques, which are present in Alzheimer's disease (AD) patient's brain. In this study, using cultured retinal cells as a neuronal model, we analyzed the effect of the synthetic peptide Abeta(25-35) on the activity of AChE, the degradation enzyme of acetylcholine, as well as the involvement of oxidative stress in this process. The activity of AChE was increased when retinal cells were incubated with Abeta(25-35) (25 microM, 24 h) and antioxidants such as alpha-tocopherol acetate and nitric oxide synthase (NOS) inhibitors were capable of preventing this effect. Despite Abeta(25-35) did not affect cell membrane integrity, the redox capacity of cells decreased. The incubation with this amyloidogenic peptide led to an increment of reactive oxygen species formation (20%), of lipid peroxidation (65%), and basal intracellular calcium levels (40%). The data obtained show that the enhancement of AChE activity induced by Abeta(25-35) is mediated by oxidative stress, and that vitamin E and NOS inhibitors, by preventing the compromise of the enzyme activity, can have an important role in the maintenance of acetylcholine synaptic levels, thus preventing or improving cognitive and memory functions of AD patients.
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Affiliation(s)
- Joana Barbosa Melo
- Center for Neurosciences of Coimbra and Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal
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71
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Nagai T, Yamada K, Kim HC, Kim YS, Noda Y, Imura A, Nabeshima YI, Nabeshima T. Cognition impairment in the genetic model of aging klotho gene mutant mice: a role of oxidative stress. FASEB J 2003; 17:50-2. [PMID: 12475907 DOI: 10.1096/fj.02-0448fje] [Citation(s) in RCA: 236] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A new gene, termed klotho, is associated with the suppression of several aging phenotypes. Because high expression of klotho gene was detected in the brain, it would be plausible that klotho gene is involved in the regulation of brain aging. We investigated the changes in mnemonic function accompanying aging in klotho mutant mice. Cognitive function measured by novel-object recognition and conditioned-fear tests in klotho mutant mice was normal at the age of 6 wk, but markedly impaired at the age of 7 wk. Lipid (malondialdehyde) and DNA (8-hydroxy-2'-deoxyguanosine) peroxide levels in the hippocampus of klotho mutant mice increased at the age of 5 wk, 2 wk before the development of cognition deficits. Pro-death Bax increased, whereas anti-death Bcl-2 and Bcl-XL decreased, and apoptotic TUNEL-positive cells were detected in the hippocampus of klotho mutant mice at the age of 7 wk. A potent antioxidant, a-tocopherol, prevented cognition impairment and lipid peroxide accumulation and decreased the number of apoptotic cells in klotho mutant mice. These results suggest that oxidative stress has a crucial role in the aging-associated cognition impairment in klotho mutant mice. Klotho protein may be involved in the regulation of antioxidative defense.
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Affiliation(s)
- Taku Nagai
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan
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72
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Olariu A, Yamada K, Mamiya T, Hefco V, Nabeshima T. Memory impairment induced by chronic intracerebroventricular infusion of beta-amyloid (1-40) involves downregulation of protein kinase C. Brain Res 2002; 957:278-86. [PMID: 12445970 DOI: 10.1016/s0006-8993(02)03608-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Signaling pathways underlying the cognitive deficit of the Alzheimer's disease (AD) are not completely understood. Protein kinase C (PKC), a major neuronal protein plays a critical role in cellular signal transduction and it is known to be subjected to modulation in AD. We showed previously that, chronic infusion of beta-amyloid (1-40) into rat cerebroventricle leads to deficit in spatial and non-spatial memory formation. As an attempt to identify the cellular correlates of the memory deficit, in the present study we investigated the PKC activation in different brain areas. Chronic infusion of beta-amyloid (1-40) for 14 days into the rat cerebroventricle decreased the activity of soluble protein kinase C (PKC) in the hippocampus. Subcellular translocation of PKC to membrane fraction in hippocampal slices of rats treated with beta-amyloid (1-40) was completely abolished under acute stimulation with 0.5 microM phorbol-dibutyrate (PDBu). We also reported a decreased affinity (k(D)) for PDBu binding in the hippocampus, cerebral cortex and striatum. The total number of binding sites for PDBu (B(max)) was increased, in the three brain areas analyzed on the day 14, but the changes were not statistically significant. Our data indicate that chronic accumulation of beta-amyloid (1-40) into the rat brain reduced activation of PKC, effect that would substantially contribute to the memory deficit found in these animals.
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Affiliation(s)
- Ana Olariu
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya, Japan
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73
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Auld DS, Kornecook TJ, Bastianetto S, Quirion R. Alzheimer's disease and the basal forebrain cholinergic system: relations to beta-amyloid peptides, cognition, and treatment strategies. Prog Neurobiol 2002; 68:209-45. [PMID: 12450488 DOI: 10.1016/s0301-0082(02)00079-5] [Citation(s) in RCA: 472] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD) is the most common form of degenerative dementia and is characterized by progressive impairment in cognitive function during mid- to late-adult life. Brains from AD patients show several distinct neuropathological features, including extracellular beta-amyloid-containing plaques, intracellular neurofibrillary tangles composed of abnormally phosphorylated tau, and degeneration of cholinergic neurons of the basal forebrain. In this review, we will present evidence implicating involvement of the basal forebrain cholinergic system in AD pathogenesis and its accompanying cognitive deficits. We will initially discuss recent results indicating a link between cholinergic mechanisms and the pathogenic events that characterize AD, notably amyloid-beta peptides. Following this, animal models of dementia will be discussed in light of the relationship between basal forebrain cholinergic hypofunction and cognitive impairments in AD. Finally, past, present, and future treatment strategies aimed at alleviating the cognitive symptomatology of AD by improving basal forebrain cholinergic function will be addressed.
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Affiliation(s)
- Daniel S Auld
- Douglas Hospital Research Centre, 6875 Blvd Lasalle, Verdun, Que, Canada H4H 1R3
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74
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Tran MH, Yamada K, Nabeshima T. Amyloid beta-peptide induces cholinergic dysfunction and cognitive deficits: a minireview. Peptides 2002; 23:1271-83. [PMID: 12128084 DOI: 10.1016/s0196-9781(02)00062-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Amyloid beta-peptide (Abeta) plays a critical role in the development of Alzheimer's disease (AD). Much progress has been made in understanding this age-related neurodegenerative disorder, thus an insight into the cellular actions of Abeta and resulting functional consequences may contribute to preventive and therapeutic approaches for AD. In this review, recent evidence of Abeta-induced brain dysfunction, particularly of cholinergic impairment and memory deficits is summarized. Moreover, proposed mechanisms for Abeta-induced neurotoxicity such as oxidative stress, ion-channel formation, and Abeta-receptor interaction are discussed.
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Affiliation(s)
- Manh Hung Tran
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan
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75
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Aldskogius H. Regulation of microglia - potential new drug targets in the CNS. Expert Opin Ther Targets 2001; 5:655-668. [PMID: 12540276 DOI: 10.1517/14728222.5.6.655] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Microglia respond to any disturbance in the CNS which poses a threat to physiological homeostasis. Although these responses are secondary, mainly to neuronal alterations, the way the microglial response evolves in many situations promotes further damage to the CNS. The list of clinical conditions in which this situation is a major problem is continuously growing and includes neurodegenerative diseases, stroke, trauma, demyelinating disorders and neuropathic pain. The significance of microglia for the pathogenesis of neurological and neuropsychiatric conditions has led to a rapidly expanding search for therapeutic possibilities to regulate microglial activity. As will be clear from this review, treatments which are currently available appear to offer some positive effects but are still far from satisfactory. A major challenge is to understand the mechanisms that determine whether activated microglia will develop into a cytotoxic or a cytoprotective component.
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Affiliation(s)
- Håkan Aldskogius
- Department of Neuroscience, Biomedical Center, PO Box 587, SE-751 23 Uppsala, Sweden.
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