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Treatment with the neurotoxic Aβ (25-35) peptide modulates the expression of neuroprotective factors Pin1, Sirtuin 1, and brain-derived neurotrophic factor in SH-SY5Y human neuroblastoma cells. ACTA ACUST UNITED AC 2016; 68:271-6. [PMID: 26915812 DOI: 10.1016/j.etp.2016.02.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/12/2016] [Accepted: 02/15/2016] [Indexed: 12/12/2022]
Abstract
The deposition of Amyloid β peptide plaques is a pathological hallmark of Alzheimer's disease (AD). The Aβ (25-35) peptide is regarded as the toxic fragment of full-length Aβ (1-42). The mechanism of its toxicity is not completely understood, along with its contribution to AD pathological processes. The aim of this study was to investigate the effect of the neurotoxic Aβ (25-35) peptide on the expression of the neuroprotective factors Pin1, Sirtuin1, and Bdnf in human neuroblastoma cells. Levels of Pin1, Sirtuin 1, and Bdnf were compared by real-time PCR and Western blotting in SH-SY5Y cells treated with Aβ (25-35) or administration vehicle. The level of Pin1 gene and protein expression was significantly decreased in cells exposed to 25 μM Aβ (25-35) compared to vehicle-treated controls. Similarly, Sirtuin1 expression was significantly reduced by Aβ (25-35) exposure. In contrast, both Bdnf mRNA and protein levels were significantly increased by Aβ (25-35) treatment, suggesting the activation of a compensatory response to the insult. Both Pin1 and Sirtuin 1 exert a protective role by reducing the probability of plaque deposition, since they promote amyloid precursor protein processing through non-amyloidogenic pathways. The present results show that Aβ (25-35) peptide reduced the production of these neuroprotective proteins, thus further increasing Aβ generation.
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Naert G, Zussy C, Tran Van Ba C, Chevallier N, Tang YP, Maurice T, Givalois L. Involvement of Endogenous Brain-Derived Neurotrophic Factor in Hypothalamic-Pituitary-Adrenal Axis Activity. J Neuroendocrinol 2015; 27:850-60. [PMID: 26388293 DOI: 10.1111/jne.12324] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 09/03/2015] [Accepted: 09/13/2015] [Indexed: 12/29/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) appears to be highly involved in hypothalamic-pituitary-adrenal (HPA) axis regulation during adulthood, playing an important role in homeostasis maintenance. The present study aimed to determine the involvement of BDNF in HPA axis activity under basal and stress conditions via partial inhibition of this endogenous neurotrophin. Experiments were conducted in rats and mice with two complementary approaches: (i) BDNF knockdown with stereotaxic delivery of BDNF-specific small interfering RNA (siRNA) into the lateral ventricle of adult male rats and (ii) genetically induced knockdown (KD) of BDNF expression specifically in the central nervous system during the first ontogenesis in mice (KD mice). Delivery of siRNA in the rat brain decreased BDNF levels in the hippocampus (-31%) and hypothalamus (-35%) but not in the amygdala, frontal cortex and pituitary. In addition, siRNA induced no change of the basal HPA axis activity. BDNF siRNA rats exhibited decreased BDNF levels and concomitant altered adrenocortoctrophic hormone (ACTH) and corticosterone responses to restraint stress, suggesting the involvement of BDNF in the HPA axis adaptive response to stress. In KD mice, BDNF levels in the hippocampus and hypothalamus were decreased by 20% in heterozygous and by 60% in homozygous animals compared to wild-type littermates. Although, in heterozygous KD mice, no significant change was observed in the basal levels of plasma ACTH and corticosterone, both hormones were significantly increased in homozygous KD mice, demonstrating that robust cerebral BDNF inhibition (60%) is necessary to affect basal HPA axis activity. All of these results in both rats and mice demonstrate the involvement and importance of a robust endogenous pool of BDNF in basal HPA axis regulation and the pivotal function of de novo BDNF synthesis in the establishment of an adapted response to stress.
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Affiliation(s)
- G Naert
- Molecular Mechanisms in Neurodegenerative Dementia Laboratory, Inserm, U1198 Montpellier, France
- University of Montpellier, Montpellier, France
- EPHE, Paris, France
| | - C Zussy
- Molecular Mechanisms in Neurodegenerative Dementia Laboratory, Inserm, U1198 Montpellier, France
- University of Montpellier, Montpellier, France
- EPHE, Paris, France
| | - C Tran Van Ba
- Molecular Mechanisms in Neurodegenerative Dementia Laboratory, Inserm, U1198 Montpellier, France
- University of Montpellier, Montpellier, France
- EPHE, Paris, France
| | - N Chevallier
- Molecular Mechanisms in Neurodegenerative Dementia Laboratory, Inserm, U1198 Montpellier, France
- University of Montpellier, Montpellier, France
- EPHE, Paris, France
| | - Y-P Tang
- Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center (LSUHSC), New Orleans, LA, USA
| | - T Maurice
- Molecular Mechanisms in Neurodegenerative Dementia Laboratory, Inserm, U1198 Montpellier, France
- University of Montpellier, Montpellier, France
- EPHE, Paris, France
| | - L Givalois
- Molecular Mechanisms in Neurodegenerative Dementia Laboratory, Inserm, U1198 Montpellier, France
- University of Montpellier, Montpellier, France
- EPHE, Paris, France
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Meunier J, Villard V, Givalois L, Maurice T. The γ-secretase inhibitor 2-[(1R)-1-[(4-chlorophenyl)sulfonyl](2,5-difluorophenyl) amino]ethyl-5-fluorobenzenebutanoic acid (BMS-299897) alleviates Aβ1–42 seeding and short-term memory deficits in the Aβ25–35 mouse model of Alzheimer's disease. Eur J Pharmacol 2013; 698:193-9. [DOI: 10.1016/j.ejphar.2012.10.033] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 10/15/2012] [Accepted: 10/23/2012] [Indexed: 02/08/2023]
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Chambon C, Wegener N, Gravius A, Danysz W. Behavioural and cellular effects of exogenous amyloid-β peptides in rodents. Behav Brain Res 2011; 225:623-41. [PMID: 21884730 DOI: 10.1016/j.bbr.2011.08.024] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 08/10/2011] [Accepted: 08/16/2011] [Indexed: 12/29/2022]
Abstract
A better understanding of Alzheimer's disease (AD) and the development of disease modifying therapies are some of the biggest challenges of the 21st century. One of the core features of AD are amyloid plaques composed of amyloid-beta (Aβ) peptides. The first hypothesis proposed that cognitive deficits are linked to plaque-development and transgenic mice have been generated to study this link, thereby providing a good model to develop new therapeutic approaches. Since later it was recognised that in AD patients the cognitive deficit is rather correlated to soluble amyloid levels, consequently, a new hypothesis appeared associating the earliest amyloid toxicity to these soluble species. The purpose of this review is to give a summary of behavioural and cellular data obtained after soluble Aβ peptide administration into rodents' brain, thereby showing that this model is a valid tool to investigate AD pathology when no plaques are present. Additionally, this method offers an excellent, efficient model to test compounds which could act at such early stages of the disease.
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Affiliation(s)
- Caroline Chambon
- In Vivo Pharmacology, Merz Pharmaceuticals GmbH, Eckenheimer Landstrasse 100, D-60318 Frankfurt am Main, Germany.
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Zussy C, Brureau A, Delair B, Marchal S, Keller E, Ixart G, Naert G, Meunier J, Chevallier N, Maurice T, Givalois L. Time-course and regional analyses of the physiopathological changes induced after cerebral injection of an amyloid β fragment in rats. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:315-34. [PMID: 21703413 DOI: 10.1016/j.ajpath.2011.03.021] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 03/22/2011] [Accepted: 03/29/2011] [Indexed: 10/18/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative pathology characterized by the presence of senile plaques and neurofibrillary tangles, accompanied by synaptic and neuronal loss. The major component of senile plaques is an amyloid β protein (Aβ) formed by pathological processing of the Aβ precursor protein. We assessed the time-course and regional effects of a single intracerebroventricular injection of aggregated Aβ fragment 25-35 (Aβ(25-35)) in rats. Using a combined biochemical, behavioral, and morphological approach, we analyzed the peptide effects after 1, 2, and 3 weeks in the hippocampus, cortex, amygdala, and hypothalamus. The scrambled Aβ(25-35) peptide was used as negative control. The aggregated forms of Aβ peptides were first characterized using electron microscopy, infrared spectroscopy, and Congo Red staining. Intracerebroventricular injection of Aβ(25-35) decreased body weight, induced short- and long-term memory impairments, increased endocrine stress, cerebral oxidative and cellular stress, neuroinflammation, and neuroprotective reactions, and modified endogenous amyloid processing, with specific time-course and regional responses. Moreover, Aβ(25-35), the presence of which was shown in the different brain structures and over 3 weeks, provoked a rapid glial activation, acetylcholine homeostasis perturbation, and hippocampal morphological alterations. In conclusion, the acute intracerebroventricular Aβ(25-35) injection induced substantial central modifications in rats, highly reminiscent of the human physiopathology, that could contribute to physiological and cognitive deficits observed in AD.
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Affiliation(s)
- Charleine Zussy
- Molecular Mechanisms in Neurodegenerative Dementia Laboratory, Inserm U710, Montpellier, France
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Figueiró M, Ilha J, Linck VM, Herrmann AP, Nardin P, Menezes CB, Achaval M, Gonçalves CA, Porciúncula LO, Nunes DS, Elisabetsky E. The Amazonian herbal Marapuama attenuates cognitive impairment and neuroglial degeneration in a mouse Alzheimer model. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2011; 18:327-333. [PMID: 20739160 DOI: 10.1016/j.phymed.2010.07.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
UNLABELLED Alzheimer's disease (AD) is expected to affect more than 22 million people worldwide by 2025, causing devastating suffering and enormous costs to families and society. AD is a multifactorial disease, with a complex pathological mosaic. In rodents, AD-like dementia can be induced by cerebral microinjection of Aβ peptide, leading to amyloid deposits, amnesia and various features of neurodegeneration. Marapuama (Ptychopetalum olacoides) is regarded as a "brain tonic" in the Amazon region and shows a nootropic profile in rodents. AIM OF THE STUDY Because a specific extract (POEE) of Marapuama was shown to possess promnesic and anti-amnesic properties, the aim of this study was to verify if POEE is also effective against Aβ(1-42)-induced cognitive deficit in mice. Additionally, Aβ deposits (Congo red), GFAP immunoreactivity (immunohistochemistry), and neurodegenerative changes in the hippocampal pyramidal layer (Nissl) were examined as measures of Aβ(1-42)-induced neurodegeneration. MATERIALS AND METHODS CF1 mice were subjected to the experimental Alzheimer model with the Aβ(1-42) i.c.v. administration. The effects of POEE 800 mg/kg were evaluated over 14 consecutive days of treatment. RESULTS The data show that 14 days of oral treatment with POEE (800 mg/kg) was effective in preventing Aβ-induced cognitive impairment, without altering the levels of BDNF and with parallel reductions in Aβ deposits and astrogliosis. CA1 hippocampus loss induced by Aβ(1-42) was also diminished in POEE-treated mice. CONCLUSION This study offers evidence of functional and neuroprotective effects of two weeks treatment with a Ptychopetalum olacoides extract against Aβ peptide-induced neurotoxicity in mice. Given the multifactorial nature of neurodegeneration, the considerable potential for an AChE inhibitor displaying associated neuroprotective properties such as here reported warrants further clinic evaluation.
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Affiliation(s)
- M Figueiró
- Laboratório de Etnofarmacologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS, Brazil.
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Alkadhi KA, Srivareerat M, Tran TT. Intensification of long-term memory deficit by chronic stress and prevention by nicotine in a rat model of Alzheimer's disease. Mol Cell Neurosci 2010; 45:289-96. [PMID: 20624465 DOI: 10.1016/j.mcn.2010.06.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2010] [Revised: 06/24/2010] [Accepted: 06/28/2010] [Indexed: 12/28/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cholinergic dysfunction and deposition of beta-amyloid (Aβ) in regions of the brain associated with learning and memory. The sporadic nature and late onset of most AD cases suggests that aside from biological determinants, environmental factors such as stress may also play a role in the progression of the disease. Behavioral and molecular studies were utilized to evaluate the effects of chronic nicotine treatment in the prevention of impairment of long-term memory. The rat model of AD was induced by i.c.v. osmotic pump infusion of Aβ peptides. Chronic psychosocial stress and chronic nicotine treatment were instituted for 6weeks. Spatial memory testing in the Radial Arm Water Maze revealed that, although stress, by itself, did not affect long-term memory, the combination of chronic stress and Aβ infusion impaired long-term memory significantly more than Aβ peptides infusion alone. Chronic nicotine treatment completely prevented Aβ- and stress/Aβ combination-induced memory impairment. Furthermore, molecular findings in hippocampal CA1 region of stress/Aβ rats indicated marked reduction in the protein levels of phosphorylated cAMP response element binding (p-CREB) and calcium-calmodulin-dependent protein kinase IV (CaMKIV), with significant increases in the levels of brain-derived neurotrophic factor (BDNF). These disturbances in signaling pathways, which may be the underlying mechanisms of impairment of long-term memory in these rats, were totally prevented by chronic nicotine treatment.
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Affiliation(s)
- Karim A Alkadhi
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204-5037, USA.
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Aliaga E, Silhol M, Bonneau N, Maurice T, Arancibia S, Tapia-Arancibia L. Dual response of BDNF to sublethal concentrations of beta-amyloid peptides in cultured cortical neurons. Neurobiol Dis 2009; 37:208-17. [PMID: 19822210 DOI: 10.1016/j.nbd.2009.10.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 09/25/2009] [Accepted: 10/02/2009] [Indexed: 02/06/2023] Open
Abstract
Beta-amyloid (Abeta) deposition is one important pathological hallmark in Alzheimer's disease (AD). However, low levels of Abeta may modify critical endogenous protection systems before neurodegeneration occurs. We examined the time-course effect of sublethal concentrations of Abeta on total BDNF (panBDNF), BDNF transcripts (I, II, IV and VI), trkB.FL, trkB.T1 and p75(NGFR) mRNA expression in cultured cortical neurons. We have shown that Abeta exhibited a dual response on BDNF mRNA, i.e. an increase at short times (3-5 h) and a dramatic decrease at longer times (24 or 48 h). The early increase in BDNF expression seems to be driven by increased expression of transcripts I and IV. The BDNF drop was specific since did not occur for other mRNAs examined. The BDNF protein content showed a similar profile but did not follow the dramatic reduction as its encoding mRNA. These observations may help to explain cognitive deficits observed at initial stages of AD.
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Affiliation(s)
- E Aliaga
- Centro de Neurobiología y Plasticidad del Desarrollo, Departamento de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretaña 1111, Playa Ancha, Valparaíso, Chile
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Yanashima R, Kitagawa N, Matsubara Y, Weatheritt R, Oka K, Kikuchi S, Tomita M, Ishizaki S. [Not Available]. Front Neuroinform 2009; 3:13. [PMID: 19543432 PMCID: PMC2699032 DOI: 10.3389/neuro.11/013.2009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2008] [Accepted: 04/30/2009] [Indexed: 01/25/2023] Open
Abstract
The scale-free and small-world network models reflect the functional units of networks. However, when we investigated the network properties of a signaling pathway using these models, no significant differences were found between the original undirected graphs and the graphs in which inactive proteins were eliminated from the gene expression data. We analyzed signaling networks by focusing on those pathways that best reflected cellular function. Therefore, our analysis of pathways started from the ligands and progressed to transcription factors and cytoskeletal proteins. We employed the Python module to assess the target network. This involved comparing the original and restricted signaling cascades as a directed graph using microarray gene expression profiles of late onset Alzheimer's disease. The most commonly used method of shortest-path analysis neglects to consider the influences of alternative pathways that can affect the activation of transcription factors or cytoskeletal proteins. We therefore introduced included k-shortest paths and k-cycles in our network analysis using the Python modules, which allowed us to attain a reasonable computational time and identify k-shortest paths. This technique reflected results found in vivo and identified pathways not found when shortest path or degree analysis was applied. Our module enabled us to comprehensively analyse the characteristics of biomolecular networks and also enabled analysis of the effects of diseases considering the feedback loop and feedforward loop control structures as an alternative path.
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Srivareerat M, Tran TT, Salim S, Aleisa AM, Alkadhi KA. Chronic nicotine restores normal Aβ levels and prevents short-term memory and E-LTP impairment in Aβ rat model of Alzheimer's disease. Neurobiol Aging 2009; 32:834-44. [PMID: 19464074 DOI: 10.1016/j.neurobiolaging.2009.04.015] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Revised: 04/15/2009] [Accepted: 04/19/2009] [Indexed: 11/19/2022]
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by increased deposition of beta-amyloid (Aβ) peptides and progressive cholinergic dysfunction in regions of the brain involved in learning and memory processing. In AD, progressive accumulation of Aβ peptide impairs nicotinic acetylcholine receptor (nAChR) function by an unknown mechanism believed to involve α(7)- and α(4)β(2)-nAChR blockade. The three approaches of the current study evaluated the effects of chronic nicotine treatment in the prevention of Aβ-induced impairment of learning and short-term memory. Rat AD model was induced by 14-day i.c.v. osmotic pump infusion of a 1:1 mixture of 300 pmol/day Aβ(1-40)/Aβ(1-42) or Aβ(40-1) (inactive peptide, control). The effect of nicotine (2 mg/(kg day)) on Aβ-induced spatial learning and memory impairments was assessed by evaluation of performance in the radial arm water maze (RAWM), in vivo electrophysiological recordings of early-phase long-term potentiation (E-LTP) in urethane-anesthetized rats, and immunoblot analysis to determine changes in the levels of beta-site amyloid precursor protein (APP)-cleaving enzyme (BACE), Aβ and memory-related proteins. The results indicate that 6 weeks of nicotine treatment reduced the levels of Aβ(1-40) and BACE1 peptides in hippocampal area CA1 and prevented Aβ-induced impairment of learning and short-term memory. Chronic nicotine also prevented the Aβ-induced inhibition of basal synaptic transmission and LTP in hippocampal area CA1. Furthermore, chronic nicotine treatment prevented the Aβ-induced reduction of α(7)- and α(4)-nAChR. These effects of nicotine may be due, at least in part, to upregulation of brain derived neurotropic factor (BDNF).
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Affiliation(s)
- Marisa Srivareerat
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
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Lanctôt KL, Herrmann N, Rothenburg LS. Commentary: Aβ(1–42) injection causes memory impairment, lowered cortical and serum BDNF levels, and decreased hippocampal 5-HT2A levels. Exp Neurol 2008; 212:251-4. [DOI: 10.1016/j.expneurol.2008.04.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 03/24/2008] [Accepted: 04/28/2008] [Indexed: 12/20/2022]
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Chen Q, Nakajima A, Choi SH, Xiong X, Tang YP. Loss of presenilin function causes Alzheimer's disease-like neurodegeneration in the mouse. J Neurosci Res 2008; 86:1615-25. [PMID: 18189321 DOI: 10.1002/jnr.21601] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Accumulating evidence has indicated that gain-of-function in beta-amyloid production may be not the necessary mechanism for mutant presenilin-1 (PS1) or PS2 to cause familial Alzheimer's disease (AD). In the present article, we show that conditional knockout of PS1 from the adult stage in the forebrain of mice with the PS2 null mutation triggers robust AD-like neurodegeneration including brain shrinkage, cortical and hippocampal atrophy,ventricular enlargement, severe neuronal loss, gliosis, tau hyperphosphorylation, neurofillament tangle-like structures, and intracellular filaments. Learning and memory functions in these mice are almost completely lost. Notably, there is no beta-amyloid deposition, indicating that presenilin dysfunction can directly cause neurodegeneration without the involvement of beta-amyloid. Furthermore, neurodegeneration occurs in a progressive manner following aging, suggesting that an accumulating effect of presenilin dysfunction over time might be a pathogenic mechanism for the involvement of mutant PS1/PS2 in causing AD. These results validate a mouse model characterized by the presence of many features of AD pathology. Furthermore, the demonstration of AD-like neurodegeneration in the absence of beta-amyloid deposition challenges the long-standing beta-amyloid cascade hypothesis and encourages an open debate on the role of beta-amyloid in causing AD. Most important, our results strongly suggest that to develop gamma-secretase inhibitors for the pharmacological treatment of AD may be not a reasonable strategy because antagonism of presenilin function may worsen neurodegeneration.
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Affiliation(s)
- Qian Chen
- Department of Psychiatry, University of Chicago, Chicago, Illinois 60637, USA
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Aguado-Llera D, Arilla-Ferreiro E, Chowen JA, Argente J, Puebla-Jiménez L, Frago LM, Barrios V. 17β-Estradiol protects depletion of rat temporal cortex somatostatinergic system by β-amyloid. Neurobiol Aging 2007; 28:1396-409. [PMID: 16843571 DOI: 10.1016/j.neurobiolaging.2006.06.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2006] [Revised: 05/31/2006] [Accepted: 06/12/2006] [Indexed: 01/23/2023]
Abstract
Estradiol prevents amyloid-beta peptide (Abeta)-induced cell death through estrogen receptors (ERs) and modulates somatostatin (SRIF) responsiveness in the rat brain. As intracerebroventricular (ICV) Abeta25-35 administration reduces SRIFergic tone in the temporal cortex of ovariectomized (Ovx) rats, we asked whether 17beta-estradiol (E2) treatment can restore the Abeta25-35 induced changes in SRIF content, SRIF receptor density and adenylyl cyclase (AC) activity, as well as if these effects are mediated by ERs. E2 treatment did not change Abeta25-35 levels in the temporal cortex, but partially restored the SRIFergic parameters affected by Abeta insult and decreased cell death, which was correlated with Akt activation. The ER antagonist ICI 182,780 prevented the protective effect of E2 on sst2 levels, but did not modify SRIF levels. Furthermore, ICI 182,780 treatment further decreased sst2 protein and mRNA levels when administered alone to Abeta25-35-treated rats, suggesting that it may block the effects of endogenous estrogens. These findings indicate that E2 protects the temporal cortical SRIFergic system from Abeta-induced depletion independently of Abeta accumulation.
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Affiliation(s)
- David Aguado-Llera
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Universidad Autónoma de Madrid, Avda. Menéndez Pelayo, Madrid, Spain
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Burgos-Ramos E, Hervás-Aguilar A, Puebla-Jiménez L, Boyano-Adánez MC, Arilla-Ferreiro E. Chronic but not acute intracerebroventricular administration of amyloid beta-peptide(25-35) decreases somatostatin content, adenylate cyclase activity, somatostatin-induced inhibition of adenylate cyclase activity, and adenylate cyclase I levels in the rat hippocampus. J Neurosci Res 2007; 85:433-42. [PMID: 17086550 DOI: 10.1002/jnr.21115] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although alterations in adenylate cyclase (AC) activity and somatostatin (SRIF) receptor density have been reported in Alzheimer's disease, the effects of amyloid beta-peptide (Abeta) on these parameters in the hippocampus are unknown. Our aim was to investigate whether the peptide fragment Abeta(25-35) can affect the somatostatinergic system in the rat hippocampus. Hence, Abeta(25-35) was injected intracerebroventricularly (i.c.v.) to Wistar rats in a single dose or infused via an osmotic minipump connected to a cannula implanted in the right lateral ventricle during 14 days. The animals were decapitated 7 or 14 days after the single injection and 14 days after chronic infusion of the peptide. Chronic i.c.v. infusion of Abeta(25-35) decreased SRIF-like immunoreactive content without modifying the SRIF receptor density, SRIF receptor expression, or the Gialpha(1), Gialpha(2), and Gialpha(3) protein levels in the hippocampus. This treatment, however, caused a decrease in basal and forskolin-stimulated AC activity as well as in the capacity of SRIF to inhibit AC activity. Furthermore, the protein levels of the neural-specific AC type I were significantly decreased in the hippocampus of the treated rats, whereas an increase in the levels of AC V/VI was found, with no alterations in type VIII AC. A single i.c.v. dose of Abeta(25-35) exerted no effect on SRIF content or SRIF receptors but induced a slight decrease in forskolin-stimulated AC activity and its inhibition by SRIF. Because chronic Abeta(25-35) infusion impairs learning and memory whereas SRIF facilitates these functions, the alterations described here might be physiologically important given the decreased cognitive behavior previously reported in Abeta-treated rats.
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Affiliation(s)
- E Burgos-Ramos
- Grupo de Neurobioquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
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Abstract
Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family and plays an important role in neuronal survival and plasticity in the CNS. The proform of BDNF (pro-BDNF) is secreted and cleaved extracellularly by the serine protease plasmin to mature BDNF, which potentiates synaptic plasticity and long-term potentiation. Recent findings in animal models suggest an involvement of BDNF and its genetic functional single nucleotide polymorphism in the pathogenesis of different psychiatric diseases including depression, mania, schizophrenia, eating disorders, dementia, and Huntington's disease. In the brain and serum, BDNF is modulated by different factors. It is downregulated by stress and upregulated by learning processes, several antidepressive treatments, physical activity, and dietary restriction. Measurement of BDNF serum concentrations may be of diagnostic value. Additionally, the influence of different strategies for BDNF allocation seems to be relevant for the treatment and prevention of the above psychiatric disorders.
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Affiliation(s)
- C Laske
- Universitätsklinik für Psychiatrie und Psychotherapie Tübingen.
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Laske C, Stransky E, Leyhe T, Eschweiler GW, Wittorf A, Richartz E, Bartels M, Buchkremer G, Schott K. Stage-dependent BDNF serum concentrations in Alzheimer’s disease. J Neural Transm (Vienna) 2005; 113:1217-24. [PMID: 16362629 DOI: 10.1007/s00702-005-0397-y] [Citation(s) in RCA: 242] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Accepted: 09/30/2005] [Indexed: 01/03/2023]
Abstract
Alzheimer's disease (AD) is characterized by cognitive decline and loss of neurons in specific brain regions. Recent findings have suggested an involvement of brain-derived neurotrophic factor (BDNF) in the pathogenesis of AD. BDNF is an endogenous protein involved in the maintenance of neuronal function, synaptic plasticity and structural integrity in the adult brain. To our knowledge, the present pilot study assessed for the first time BDNF serum and CSF concentrations in 30 patients with different stages of AD in comparison to 10 age-matched non-demendet controls. AD patients were divided in two groups according to their MMSE score: Group 1 (n = 15) in early stages with MMSE scores >or=21 (mean of 25.5) and Group 2 (n = 15) with more severe stages of dementia with MMSE scores <21 (mean of 13.3). As main results, we found in patients with early stages of probable AD significantly increased BDNF serum concentrations as compared to more severe stages of AD (p < 0.0001) and age-matched healthy controls (p = 0.028). BDNF serum values in all AD patients correlated significantly with MMSE scores (r = 0.486; p < 0.0001). Levels of BDNF were below the detection limit of the assay in unconcentrated CSF samples of AD patients and non-demendet controls.In summary, BDNF serum values are increased in early stages of Alzheimer's disease, which may reflect a compensatory repair mechanism in early neurodegeneration and could also contribute to increased degradation of beta-amyloid (Abeta). During the course of the disease, BDNF is decreasing, which correlates with the severity of dementia. The decrease of BDNF may constitute a lack of trophic support with an increase of Abeta accumulation and thus contribute to progressive degeneration of specific regions in the AD-affected brain. BDNF should be further evaluated as a candidate marker for clinical diagnosis and therapeutic monitoring in Alzheimer's disease.
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Affiliation(s)
- C Laske
- Department of Psychiatry and Psychotherapy, University of Tübinger, Germany.
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Szapacs ME, Numis AL, Andrews AM. Late onset loss of hippocampal 5-HT and NE is accompanied by increases in BDNF protein expression in mice co-expressing mutant APP and PS1. Neurobiol Dis 2004; 16:572-80. [PMID: 15262269 DOI: 10.1016/j.nbd.2004.04.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Revised: 02/11/2004] [Accepted: 04/16/2004] [Indexed: 12/13/2022] Open
Abstract
Transgenic mice expressing both mutant amyloid precursor protein (APPswe) and presenilin-1 (PS1DeltaE9) develop amyloid deposits as early as 4 months of age and preliminary evidence suggests that this may be associated with degenerative changes in serotonin axons innervating the dentate gyrus of the hippocampus. In the present investigation, which focused on further delineating the effects of amyloid deposition on hippocampal neurochemistry, decreases in serotonin neurotransmitter levels (-25%) were discovered to be present at 18 months in APP+/PS1+ mice, while norepinephrine was reduced in the hippocampus of 12- (-30%) and 18-month-old (-45%) APP+/PS1+ double mutants. In addition, brain-derived neurotrophic factor (BDNF) protein levels were investigated since changes in BDNF are reported to occur in AD, and BDNF has been shown to have trophic effects on serotonin and norepinephrine neurons. In doubly, but not singly mutant mice, hippocampal BDNF levels were increased at 12 (+70%) and 18 months (+170%). Furthermore, in a different model of serotonergic and noradrenergic degeneration, BDNF protein levels were similarly increased in response to depletions in hippocampal serotonin and norepinephrine caused by the chemical neurotoxin 1-methyl-4-(2'-aminophenyl)-1,2,3,6-tetrahydropyridine (2'-NH2-MPTP). These findings show that early amyloid deposition in mice expressing mutant human APP and PS-1 is associated with a progressive loss of serotonin and norepinephrine neurotransmitter levels in the hippocampus later in life. Furthermore, BDNF protein levels are increased in APP+/PS1+ and 2'-NH2-MPTP-treated mice, possibly as a compensatory response to serotonergic and noradrenergic neurodegeneration in a brain region important for learning and memory.
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Affiliation(s)
- Matthew E Szapacs
- Department of Chemistry and the Huck Institute for Life Sciences, The Pennsylvania State University, University Park, PA 16802-4615, USA
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19
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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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20
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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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21
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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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22
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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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23
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Arias C, Montiel T, Quiroz-Báez R, Massieu L. beta-Amyloid neurotoxicity is exacerbated during glycolysis inhibition and mitochondrial impairment in the rat hippocampus in vivo and in isolated nerve terminals: implications for Alzheimer's disease. Exp Neurol 2002; 176:163-74. [PMID: 12093093 DOI: 10.1006/exnr.2002.7912] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Senile plaques composed mainly by beta-amyloid (Abeta) protein are one of the pathological hallmarks of Alzheimer's disease (AD). In vitro, Abeta and its active fragment 25-35 have been shown either to be directly neurotoxic or to exacerbate the damaging effect of other neurotoxic insults. However, the attempts to replicate Abeta neurotoxicity in vivo have yielded conflicting results. One of the most consistent alterations in AD is a reduced resting glucose utilization. Important evidence suggests that impairment of brain energy metabolism can lead to neuronal damage or facilitate the deleterious effects of some neurotoxic agents. In the present study we have investigated the influence of glycolysis inhibition induced by iodoacetate, and mitochondrial impairment induced by 3-nitropropionic acid (3-NP), in the toxicity of Abeta. We have studied Abeta neurotoxicity during energy deficiency both in vivo in the dentate gyrus of the hippocampal formation and in presynaptic terminals isolated from neocortex and hippocampus. Results show that during metabolic inhibition an enhanced vulnerability of hippocampal neurons to Abeta peptide toxicity occurs, probably resulting from decreased glucose metabolism and mitochondrial ATP production. Synaptosomal response to energy impairment and Abeta toxicity was evaluated by the MTT assay. Results suggest that synapses may be particularly sensitive to metabolic perturbation, which in turn exacerbates Abeta toxicity. The present data provide experimental support to the hypothesis that certain risk factors such as metabolic dysfunction and amyloid accumulation may interact to exacerbate AD, and that metabolic substrates such as pyruvate may play a role as a therapeutic tool.
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Affiliation(s)
- Clorinda Arias
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México
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24
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Law A, Gauthier S, Quirion R. Neuroprotective and neurorescuing effects of isoform-specific nitric oxide synthase inhibitors, nitric oxide scavenger, and antioxidant against beta-amyloid toxicity. Br J Pharmacol 2001; 133:1114-24. [PMID: 11487523 PMCID: PMC1572883 DOI: 10.1038/sj.bjp.0704179] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Beta amyloid (Abeta) is implicated in Alzheimer's disease (AD). Abeta(1 - 42) (5, 10, or 20 microM) was able to increase NO release and decrease cellular viability in primary rat cortical mixed cultures. L-NOARG and SMTC (both at 10 or 100 microM) - type I NOS inhibitors - reduced cellular NO release in the absence of Abeta(1 - 42). At 100 microM, both drugs decreased cell viability. L-NIL (10 or 100 microM), and 1400W (1 or 5 microM) - type II NOS inhibitors - reduced NO release and improved viability when either drug was administered up to 4 h post Abeta(1 - 42) (10 microM) treatment. L-NOARG and SMTC (both at 10 or 100 microM) were only able to decrease NO release. Carboxy-PTIO or Trolox (both at 10 or 100 microM) - a NO scavenger and an antioxidant, respectively - increased viability when administered up to 1 h post Abeta(1 - 42) treatment. Either L-NIL (50 microM) or 1400W (3 microM) and Trolox (50 microM) showed synergistic actions. Peroxynitrite (100 or 200 microM) reduced cell viability. Viabilities were improved by L-NIL (100 microM), 1400W (5 microM), carboxy-PTIO (10 or 100 microM), and Trolox (10 or 100 microM). Hence, the data show that Abeta(1 - 42) induced NO release in neurons and glial cells, and that Abeta neurotoxicity is, at least in part, mediated by NO. NO concentration modulating compounds and antioxidant may have therapeutic importance in neurological disorders where oxidative stress is likely involved such as in AD.
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Affiliation(s)
- A Law
- Douglas Hospital Research Centre, Verdun, Québec, Canada, H4H 1R3
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada, H3B 2A1
| | - S Gauthier
- Douglas Hospital Research Centre, Verdun, Québec, Canada, H4H 1R3
- McGill Centre for Studies in Aging, Vérdun, Québec, Canada, H4H 1R3
| | - R Quirion
- Douglas Hospital Research Centre, Verdun, Québec, Canada, H4H 1R3
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada, H3B 2A1
- McGill Centre for Studies in Aging, Vérdun, Québec, Canada, H4H 1R3
- Author for correspondence:
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