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Jiang H, Jiang W, Zou J, Wang B, Yu M, Pan Y, Lin Y, Mao Y, Wang Y. The GluN2B subunit of N-methy-D-asparate receptor regulates the radial migration of cortical neurons in vivo. Brain Res 2015; 1610:20-32. [PMID: 25838242 DOI: 10.1016/j.brainres.2015.03.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Revised: 02/01/2015] [Accepted: 03/09/2015] [Indexed: 10/23/2022]
Abstract
The formation of layered structure of the mammalian neocortex requires a fine organized migration of post-mitotic neurons during early development. However, whether the radial migration is regulated by NMDA receptor and specific subunits remains contradictory and unknown. Here, we reported that in the developing rat cortex, migration of presumptive layer II/III neurons to their deserved destination was regulated by NMDA receptors with GluN2B but not GluN2A subunit. Using in utero electroporation of small interference RNA (siRNA) of distinct NMDA receptor subunits, we found that knockdown GluN1 and GluN2B subunits dramatically delayed the neuronal migration to proper layer II/III, while improperly stayed at lower layers or even the germinal regions, without changing the cell fate. In contrast, knockdown of GluN2A subunit did not impair the neuronal migration. Additionally, the ecotopic neurons by GluN2B RNAi developed to well dendritic differentiation, while the ones by GluN1 RNAi still kept morphology of migrating neurons. Therefore, GluN2B subunit of NMDA receptor plays an essential role in regulating proper neuronal migration and cortical lamination.
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Affiliation(s)
- Huayu Jiang
- Neurology Department, Shanghai Tenth People׳s Hospital, Tongji University, School of Medicine, Shanghai 200072, China
| | - Weiqing Jiang
- Department of Neurology, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Jing Zou
- Department of Neurology, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Baoxiang Wang
- Department of Neurology, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Mingrong Yu
- Neurology Department, Qiqihar Hospital, Heilongjiang Agriculture Reclamation Bureau, Qiqihar 161005, China
| | - Yuanmei Pan
- Department of Neurology, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Yan Lin
- Department of Neurology, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Yingwei Mao
- Department of Biology, 214 Life Sciences Building Penn State University, University Park, PA 16802, USA
| | - Yonggang Wang
- Neurology Department, Shanghai Tenth People׳s Hospital, Tongji University, School of Medicine, Shanghai 200072, China.
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Sabogal-Guáqueta AM, Muñoz-Manco JI, Ramírez-Pineda JR, Lamprea-Rodriguez M, Osorio E, Cardona-Gómez GP. The flavonoid quercetin ameliorates Alzheimer's disease pathology and protects cognitive and emotional function in aged triple transgenic Alzheimer's disease model mice. Neuropharmacology 2015; 93:134-45. [PMID: 25666032 DOI: 10.1016/j.neuropharm.2015.01.027] [Citation(s) in RCA: 265] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 01/21/2015] [Accepted: 01/26/2015] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD) is the most common senile dementia in the world. Although important progress has been made in understanding the pathogenesis of AD, current therapeutic approaches provide only modest symptomatic relief. In this study, we evaluated the neuroprotective effect of quercetin (25 mg/kg) administration via i.p. injection every 48 h for 3 months on aged (21-24 months old) triple transgenic AD model (3xTg-AD) mice. Our data show that quercetin decreases extracellular β-amyloidosis, tauopathy, astrogliosis and microgliosis in the hippocampus and the amygdala. These results were supported by a significant reduction in the paired helical filament (PHF), β-amyloid (βA) 1-40 and βA 1-42 levels and a decrease in BACE1-mediated cleavage of APP (into CTFβ). Additionally, quercetin induced improved performance on learning and spatial memory tasks and greater risk assessment behavior based on the elevated plus maze test. Together, these findings suggest that quercetin reverses histological hallmarks of AD and protects cognitive and emotional function in aged 3xTg-AD mice.
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Affiliation(s)
- Angélica Maria Sabogal-Guáqueta
- Neuroscience Group of Antioquia, Cellular and Molecular Neurobiology Area, Faculty of Medicine, University of Antioquia, Calle 70 No. 52-21, Medellin, Colombia
| | - Juan Ignacio Muñoz-Manco
- Neuroscience Group of Antioquia, Cellular and Molecular Neurobiology Area, Faculty of Medicine, University of Antioquia, Calle 70 No. 52-21, Medellin, Colombia
| | - Jose R Ramírez-Pineda
- Grupo de Investigación en Sustancias Bioactivas, Facultad de Química Farmacéutica, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia; Group of Immunomodulation, Faculty of Medicine, University of Antioquia, Calle 70 No. 52-21, Medellin, Colombia
| | | | - Edison Osorio
- Grupo de Investigación en Sustancias Bioactivas, Facultad de Química Farmacéutica, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Gloria Patricia Cardona-Gómez
- Neuroscience Group of Antioquia, Cellular and Molecular Neurobiology Area, Faculty of Medicine, University of Antioquia, Calle 70 No. 52-21, Medellin, Colombia.
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Tu S, Okamoto SI, Lipton SA, Xu H. Oligomeric Aβ-induced synaptic dysfunction in Alzheimer's disease. Mol Neurodegener 2014; 9:48. [PMID: 25394486 PMCID: PMC4237769 DOI: 10.1186/1750-1326-9-48] [Citation(s) in RCA: 370] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 10/08/2014] [Indexed: 11/30/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating disease characterized by synaptic and neuronal loss in the elderly. Compelling evidence suggests that soluble amyloid-β peptide (Aβ) oligomers induce synaptic loss in AD. Aβ-induced synaptic dysfunction is dependent on overstimulation of N-methyl-D-aspartate receptors (NMDARs) resulting in aberrant activation of redox-mediated events as well as elevation of cytoplasmic Ca2+, which in turn triggers downstream pathways involving phospho-tau (p-tau), caspases, Cdk5/dynamin-related protein 1 (Drp1), calcineurin/PP2B, PP2A, Gsk-3β, Fyn, cofilin, and CaMKII and causes endocytosis of AMPA receptors (AMPARs) as well as NMDARs. Dysfunction in these pathways leads to mitochondrial dysfunction, bioenergetic compromise and consequent synaptic dysfunction and loss, impaired long-term potentiation (LTP), and cognitive decline. Evidence also suggests that Aβ may, at least in part, mediate these events by causing an aberrant rise in extrasynaptic glutamate levels by inhibiting glutamate uptake or triggering glutamate release from glial cells. Consequent extrasynaptic NMDAR (eNMDAR) overstimulation then results in synaptic dysfunction via the aforementioned pathways. Consistent with this model of Aβ-induced synaptic loss, Aβ synaptic toxicity can be partially ameliorated by the NMDAR antagonists (such as memantine and NitroMemantine). PSD-95, an important scaffolding protein that regulates synaptic distribution and activity of both NMDA and AMPA receptors, is also functionally disrupted by Aβ. PSD-95 dysregulation is likely an important intermediate step in the pathological cascade of events caused by Aβ. In summary, Aβ-induced synaptic dysfunction is a complicated process involving multiple pathways, components and biological events, and their underlying mechanisms, albeit as yet incompletely understood, may offer hope for new therapeutic avenues.
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Affiliation(s)
- Shichun Tu
- Neuroscience and Aging Research Center, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Alkadhi KA, Tran TT. Chronic Stress Decreases Basal Levels of Memory-Related Signaling Molecules in Area CA1 of At-Risk (Subclinical) Model of Alzheimer’s Disease. Mol Neurobiol 2014; 52:93-100. [DOI: 10.1007/s12035-014-8839-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 07/30/2014] [Indexed: 11/28/2022]
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Cantanelli P, Sperduti S, Ciavardelli D, Stuppia L, Gatta V, Sensi SL. Age-Dependent Modifications of AMPA Receptor Subunit Expression Levels and Related Cognitive Effects in 3xTg-AD Mice. Front Aging Neurosci 2014; 6:200. [PMID: 25140151 PMCID: PMC4122177 DOI: 10.3389/fnagi.2014.00200] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 07/21/2014] [Indexed: 12/22/2022] Open
Abstract
GluA1, GluA2, GluA3, and GluA4 are the constitutive subunits of amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs), the major mediators of fast excitatory transmission in the mammalian central nervous system. Most AMPARs are Ca2+-impermeable because of the presence of the GluA2 subunit. GluA2 mRNA undergoes an editing process that results in a Q–R substitution, a key factor in the regulation of AMPAR Ca2+-permeability. AMPARs lacking GluA2 or containing the unedited subunit are permeable to Ca2+ and Zn2+. The phenomenon physiologically modulates synaptic plasticity while, in pathologic conditions, leads to increased vulnerability to excitotoxic neuronal death. Given the importance of these subunits, we have therefore evaluated possible associations between changes in expression levels of AMPAR subunits and development of cognitive deficits in 3xTg-AD mice, a widely investigated transgenic mouse model of Alzheimer’s disease (AD). With quantitative real-time PCR analysis, we assayed hippocampal mRNA expression levels of GluA1–4 subunits occurring in young [3 months of age (m.o.a.)] and old (12 m.o.a) Tg-AD mice and made comparisons with levels found in age-matched wild type (WT) mice. Efficiency of GluA2 RNA editing was also analyzed. All animals were cognitively tested for learning short- and long-term spatial memory with the Morris Water Maze (MWM) navigation task. 3xTg-AD mice showed age-dependent decreases of mRNA levels for all the AMPAR subunits, with the exception of GluA2. Editing remained fully efficient with aging in 3xTg-AD and WT mice. A one-to-one correlation analysis between MWM performances and GluA1–4 mRNA expression profiles showed negative correlations between GluA2 levels and MWM performances in young 3xTg-AD mice. On the contrary, positive correlations between GluA2 mRNA and MWM performances were found in young WT mice. Our data suggest that increases of AMPARs that contain GluA1, GluA3, and GluA4 subunits may help in maintaining cognition in pre-symptomatic 3xTg-AD mice.
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Affiliation(s)
- Pamela Cantanelli
- Molecular Neurology Unit, Center of Excellence on Aging (CeSI), "G. d'Annunzio" University , Chieti , Italy
| | - Samantha Sperduti
- Functional Genetics Unit, Center of Excellence on Aging (CeSI), "G. d'Annunzio" University , Chieti , Italy ; Department of Psychological Sciences, School of Medicine and Health Sciences, "G. d'Annunzio" University , Chieti , Italy
| | - Domenico Ciavardelli
- Molecular Neurology Unit, Center of Excellence on Aging (CeSI), "G. d'Annunzio" University , Chieti , Italy ; School of Human and Social Science, Kore University of Enna , Enna , Italy
| | - Liborio Stuppia
- Functional Genetics Unit, Center of Excellence on Aging (CeSI), "G. d'Annunzio" University , Chieti , Italy ; Department of Psychological Sciences, School of Medicine and Health Sciences, "G. d'Annunzio" University , Chieti , Italy
| | - Valentina Gatta
- Functional Genetics Unit, Center of Excellence on Aging (CeSI), "G. d'Annunzio" University , Chieti , Italy ; Department of Psychological Sciences, School of Medicine and Health Sciences, "G. d'Annunzio" University , Chieti , Italy
| | - Stefano Luca Sensi
- Molecular Neurology Unit, Center of Excellence on Aging (CeSI), "G. d'Annunzio" University , Chieti , Italy ; Department of Neuroscience and Imaging, "G. d'Annunzio" University , Chieti , Italy ; Department of Neurology, Institute for Memory Impairments and Neurological Disorders, University of California Irvine , Irvine, CA , USA ; Department of Pharmacology, Institute for Memory Impairments and Neurological Disorders, University of California Irvine , Irvine, CA , USA
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Weiss S, Mori F, Rossi S, Centonze D. Disability in multiple sclerosis: When synaptic long-term potentiation fails. Neurosci Biobehav Rev 2014; 43:88-99. [DOI: 10.1016/j.neubiorev.2014.03.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 02/11/2014] [Accepted: 03/31/2014] [Indexed: 12/13/2022]
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Kook SY, Jeong H, Kang MJ, Park R, Shin HJ, Han SH, Son SM, Song H, Baik SH, Moon M, Yi EC, Hwang D, Mook-Jung I. Crucial role of calbindin-D28k in the pathogenesis of Alzheimer's disease mouse model. Cell Death Differ 2014; 21:1575-87. [PMID: 24853300 PMCID: PMC4158683 DOI: 10.1038/cdd.2014.67] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 03/03/2014] [Accepted: 04/04/2014] [Indexed: 01/22/2023] Open
Abstract
Calbindin-D28k (CB), one of the major calcium-binding and buffering proteins, has a critical role in preventing a neuronal death as well as maintaining calcium homeostasis. Although marked reductions of CB expression have been observed in the brains of mice and humans with Alzheimer disease (AD), it is unknown whether these changes contribute to AD-related dysfunction. To determine the pathogenic importance of CB depletions in AD models, we crossed 5 familial AD mutations (5XFAD; Tg) mice with CB knock-out (CBKO) mice and generated a novel line CBKO·5XFAD (CBKOTg) mice. We first identified the change of signaling pathways and differentially expressed proteins globally by removing CB in Tg mice using mass spectrometry and antibody microarray. Immunohistochemistry showed that CBKOTg mice had significant neuronal loss in the subiculum area without changing the magnitude (number) of amyloid β-peptide (Aβ) plaques deposition and elicited significant apoptotic features and mitochondrial dysfunction compared with Tg mice. Moreover, CBKOTg mice reduced levels of phosphorylated mitogen-activated protein kinase (extracellular signal-regulated kinase) 1/2 and cAMP response element-binding protein at Ser-133 and synaptic molecules such as N-methyl-D-aspartate receptor 1 (NMDA receptor 1), NMDA receptor 2A, PSD-95 and synaptophysin in the subiculum compared with Tg mice. Importantly, this is the first experimental evidence that removal of CB from amyloid precursor protein/presenilin transgenic mice aggravates AD pathogenesis, suggesting that CB has a critical role in AD pathogenesis.
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Affiliation(s)
- S-Y Kook
- Department of Biochemistry and Biomedical Sciences, Seoul National University, College of Medicine, Seoul, Korea
| | - H Jeong
- School of Interdisciplinary Bioscience and Bioengineering, Department of Chemical Engineering, POSTECH, Pohang, Korea
| | - M J Kang
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology and College of Medicine or College of Pharmacy, Seoul National University, Seoul, Korea
| | - R Park
- Department of Biochemistry and Biomedical Sciences, Seoul National University, College of Medicine, Seoul, Korea
| | - H J Shin
- Department of Biochemistry and Biomedical Sciences, Seoul National University, College of Medicine, Seoul, Korea
| | - S-H Han
- Department of Biochemistry and Biomedical Sciences, Seoul National University, College of Medicine, Seoul, Korea
| | - S M Son
- Department of Biochemistry and Biomedical Sciences, Seoul National University, College of Medicine, Seoul, Korea
| | - H Song
- Department of Biochemistry and Biomedical Sciences, Seoul National University, College of Medicine, Seoul, Korea
| | - S H Baik
- Department of Biochemistry and Biomedical Sciences, Seoul National University, College of Medicine, Seoul, Korea
| | - M Moon
- Molecular Neurobiology Laboratory, Department of Psychiatry and Mclean Hospital, Harvard Medical School, Belmont, MA, USA
| | - E C Yi
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology and College of Medicine or College of Pharmacy, Seoul National University, Seoul, Korea
| | - D Hwang
- 1] School of Interdisciplinary Bioscience and Bioengineering, Department of Chemical Engineering, POSTECH, Pohang, Korea [2] Department of New Biology and Center for Plant Aging Research, Institute for Basic Science, DGIST, Daegu, Korea
| | - I Mook-Jung
- Department of Biochemistry and Biomedical Sciences, Seoul National University, College of Medicine, Seoul, Korea
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58
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Cellular membrane fluidity in amyloid precursor protein processing. Mol Neurobiol 2014; 50:119-29. [PMID: 24553856 DOI: 10.1007/s12035-014-8652-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 01/23/2014] [Indexed: 12/20/2022]
Abstract
The senile plaque is a pathologic hallmark of Alzheimer's disease (AD). Amyloid-β peptide (Aβ), the main constituent of senile plaques, is neurotoxic especially in its oligomeric form. Aβ is derived from the sequential cleavage of amyloid precursor protein (APP) by β- and γ-secretases in the amyloidogenic pathway. Alternatively, APP can be cleaved by α-secretases within the Aβ domain to produce neurotrophic and neuroprotective α-secretase-cleaved soluble APP (sAPPα) in the nonamyloidogenic pathway. Since APP and α-, β-, and γ-secretases are membrane proteins, APP processing should be highly dependent on the membrane composition and the biophysical properties of cellular membrane. In this review, we discuss the role of the biophysical properties of cellular membrane in APP processing, especially the effects of phospholipases A(2) (PLA(2)s), fatty acids, cholesterol, and Aβ on membrane fluidity in relation to their effects on APP processing.
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Taghizadeh M, Talaei SA, Djazayeri A, Salami M. Vitamin D supplementation restores suppressed synaptic plasticity in Alzheimer's disease. Nutr Neurosci 2013; 17:172-7. [DOI: 10.1179/1476830513y.0000000080] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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60
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Cognitive recovery and restoration of cell proliferation in the dentate gyrus in the 5XFAD transgenic mice model of Alzheimer's disease following 2-hydroxy-DHA treatment. Biogerontology 2013; 14:763-75. [PMID: 24114505 DOI: 10.1007/s10522-013-9461-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 08/30/2013] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder in the elderly. In the last years, abnormalities of lipid metabolism and in particular of docosahexaenoic acid (DHA) have been recently linked with the development of the disease. According to the recent studies showing how hydroxylation of fatty acids enhances their biological activity, here we show that chronic treatment with a hydroxylated derivative of DHA, the 2-hydroxy-DHA (2OHDHA) in the 5XFAD transgenic mice model of AD improves performance in the radial arm maze test and restores cell proliferation in the dentate gyrus, with no changes in the presence of beta amyloid (Aβ) plaques. These results suggest that 2OHDHA induced restoration of cell proliferation can be regarded as a major component in memory recovery that is independent of Aβ load thus, setting the starting point for the development of a new drug for the treatment of AD.
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Lam J, Coleman N, Garing ALA, Wulff H. The therapeutic potential of small-conductance KCa2 channels in neurodegenerative and psychiatric diseases. Expert Opin Ther Targets 2013; 17:1203-20. [PMID: 23883298 DOI: 10.1517/14728222.2013.823161] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION KCa2 or small-conductance Ca(2+)-activated K(+) channels (SK) are expressed in many areas of the central nervous system where they participate in the regulation of neuronal afterhyperpolarization and excitability, and also serve as negative feedback regulators on the glutamate-NMDA pathway. AREAS COVERED This review focuses on the role of KCa2 channels in learning and memory and their potential as therapeutic targets for Alzheimer's and Parkinson's disease, ataxia, schizophrenia and alcohol dependence. EXPERT OPINION There currently exists relatively solid evidence supporting the use of KCa2 activators for ataxia. Genetic KCa2 channel suppression in deep cerebellar neurons induces ataxia, while KCa2 activators like 1-EBIO, SKA-31 and NS13001 improve motor deficits in mouse models of episodic ataxia (EA) and spinal cerebellar ataxia (SCA). Use of KCa2 activators for ataxia is further supported by a report that riluzole improves ataxia in a small clinical trial. Based on accumulating literature evidence, KCa2 activators further appear attractive for the treatment of alcohol dependence and withdrawal. Regarding Alzheimer's disease, Parkinson's disease and schizophrenia, further research, including long-term studies in disease relevant animal models, will be needed to determine whether KCa2 channels constitute valid targets and whether activators or inhibitors would be needed to positively affect disease outcomes.
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Affiliation(s)
- Jenny Lam
- University of California, Davis, Department of Pharmacology , 451 Health Sciences Drive, Genome and Biomedical Sciences Facility Room 3502, Davis, CA 95616 , USA +1 530 754 6135 ; +1 530 752 7710 ;
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Kuo MF, Paulus W, Nitsche MA. Therapeutic effects of non-invasive brain stimulation with direct currents (tDCS) in neuropsychiatric diseases. Neuroimage 2013; 85 Pt 3:948-60. [PMID: 23747962 DOI: 10.1016/j.neuroimage.2013.05.117] [Citation(s) in RCA: 277] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 04/30/2013] [Accepted: 05/23/2013] [Indexed: 12/19/2022] Open
Abstract
Neuroplasticity, which is the dynamic structural and functional reorganization of central nervous system connectivity due to environmental and internal demands, is recognized as a major physiological basis for adaption of cognition, and behavior, and thus of utmost importance for normal brain function. Pathological alterations of plasticity are increasingly explored as pathophysiological foundation of diverse neurological and psychiatric diseases. Non-invasive brain stimulation techniques (NIBS), such as repetitive transcranial magnetic stimulation (rTMS), and transcranial direct current stimulation (tDCS), are able to induce and modulate neuroplasticity in humans. Therefore, they have potential to alter pathological plasticity on the one hand, and foster physiological plasticity on the other, in neuropsychiatric diseases to reduce symptoms, and enhance rehabilitation. tDCS is an emerging NIBS tool, which induces glutamatergic plasticity via application of relatively weak currents through the scalp in humans. In the last years its efficacy to treat neuropsychiatric diseases has been explored increasingly. In this review, we will give an overview of pathological alterations of plasticity in neuropsychiatric diseases, gather clinical studies involving tDCS to ameliorate symptoms, and discuss future directions of application, with an emphasis on optimizing stimulation effects.
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Affiliation(s)
- Min-Fang Kuo
- University Medical Center, Clinic for Clinical Neurophysiology, Georg-August-University, Robert-Koch-Str. 40, 37099 Goettingen, Germany.
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63
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Huang YJ, Lin CH, Lane HY, Tsai GE. NMDA Neurotransmission Dysfunction in Behavioral and Psychological Symptoms of Alzheimer's Disease. Curr Neuropharmacol 2013; 10:272-85. [PMID: 23450042 PMCID: PMC3468881 DOI: 10.2174/157015912803217288] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 06/04/2012] [Accepted: 07/09/2012] [Indexed: 01/06/2023] Open
Abstract
Dementia has become an all-important disease because the population is aging rapidly and the cost of health care associated with dementia is ever increasing. In addition to cognitive function impairment, associated behavioral and psychological symptoms of dementia (BPSD) worsen patient’s quality of life and increase caregiver’s burden. Alzheimer’s disease is the most common type of dementia and both behavioral disturbance and cognitive impairment of Alzheimer’s disease are thought to be associated with the N-methyl-D-aspartate (NMDA) dysfunction as increasing evidence of dysfunctional glutamatergic neurotransmission had been reported in behavioral changes and cognitive decline in Alzheimer’s disease. We review the literature regarding dementia (especially Alzheimer’s disease), BPSD and relevant findings on glutamatergic and NMDA neurotransmission, including the effects of memantine, a NMDA receptor antagonist, and NMDA-enhancing agents, such as D-serine and D-cycloserine. Literatures suggest that behavioral disturbance and cognitive impairment of Alzheimer’s disease may be associated with excitatory neurotoxic effects which result in impairment of neuronal plasticity and degenerative processes. Memantine shows benefits in improving cognition, function, agitation/aggression and delusion in Alzheimer’s disease. On the other hand, some NMDA modulators which enhance NMDA function through the co-agonist binding site can also improve cognitive function and psychotic symptoms. We propose that modulating NMDA neurotransmission is effective in treating behavioral and psychological symptoms of Alzheimer’s disease. Prospective study using NMDA enhancers in patients with Alzheimer’s disease and associated behavioral disturbance is needed to verify this hypothesis.
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Affiliation(s)
- Yu-Jhen Huang
- Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan ; Department of Psychiatry, China Medical University Hospital, Taichung, Taiwan
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Moreth J, Kroker KS, Schwanzar D, Schnack C, von Arnim CAF, Hengerer B, Rosenbrock H, Kussmaul L. Globular and protofibrillar aβ aggregates impair neurotransmission by different mechanisms. Biochemistry 2013; 52:1466-76. [PMID: 23374097 DOI: 10.1021/bi3016444] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In Alzheimer's disease, substantial evidence indicates the causative role of soluble amyloid β (Aβ) aggregates. Although a variety of Aβ assemblies have been described, the debate about their individual relevance is still ongoing. One critical issue hampering this debate is the use of different methods for the characterization of endogenous and synthetic peptide and their intrinsic limitations for distinguishing Aβ aggregates. Here, we used different protocols for the establishment of prefibrillar Aβ assemblies with varying morphologies and sizes and compared them in a head-to-head fashion. Aggregation was characterized via the monomeric peptide over time until spheroidal, protofibrillar, or fibrillar Aβ aggregates were predominant. It could be shown that a change in the ionic environment induced a structural rearrangement, which consequently confounds the delineation of a measured neurotoxicity toward a distinct Aβ assembly. Here, neuronal binding and hippocampal neurotransmission were found to be suitable to account for the synaptotoxicity to different Aβ assemblies, based on the stability of the applied Aβ aggregates in these settings. In contrast to monomeric or fibrillar Aβ, different prefibrillar Aβ aggregates targeted neurons and impaired hippocampal neurotransmission with nanomolar potency, albeit by different modalities. Spheroidal Aβ aggregates inhibited NMDAR-dependent long-term potentiation, as opposed to protofibrillar Aβ aggregates, which inhibited AMPAR-dominated basal neurotransmission. In addition, a provoked structural conversion of spheroidal to protofibrillar Aβ assemblies resulted in a time-dependent suppression of basal neurotransmission, indicative of a mechanistic switch in synaptic impairment. Thus, we emphasize the importance of addressing the metastability of prefacto characterized Aβ aggregates in assigning a biological effect.
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Affiliation(s)
- Jens Moreth
- Department of CNS Diseases Research Germany, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Strasse, Biberach an der Riss D-88397, Germany.
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Dinamarca MC, Ríos JA, Inestrosa NC. Postsynaptic Receptors for Amyloid-β Oligomers as Mediators of Neuronal Damage in Alzheimer's Disease. Front Physiol 2012; 3:464. [PMID: 23267328 PMCID: PMC3526732 DOI: 10.3389/fphys.2012.00464] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 11/22/2012] [Indexed: 11/13/2022] Open
Abstract
The neurotoxic effect of amyloid-β peptide (Aβ) over the central synapses has been described and is reflected in the decrease of some postsynaptic excitatory proteins, the alteration in the number and morphology of the dendritic spines, and a decrease in long-term potentiation. Many studies has been carried out to identify the putative Aβ receptors in neurons, and is still no clear why the Aβ oligomers only affect the excitatory synapses. Aβ oligomers bind to neurite and preferentially to the postsynaptic region, where the postsynaptic protein-95 (PSD-95) is present in the glutamatergic synapse, and interacts directly with the N-methyl-D-aspartate receptor (NMDAR) and neuroligin (NL). NL is a postsynaptic protein which binds to the presynaptic protein, neurexin to form a heterophilic adhesion complex, the disruption of this interaction affects the integrity of the synaptic contact. Structurally, NL has an extracellular domain homolog to acetylcholinesterase, the first synaptic protein that was found to interact with Aβ. In the present review we will document the interaction between Aβ and the extracellular domain of NL-1 at the excitatory synapse, as well as the interaction with other postsynaptic components, including the glutamatergic receptors (NMDA and mGluR5), the prion protein, the neurotrophin receptor, and the α7-nicotinic acetylcholine receptor. We conclude that several Aβ oligomers receptors exist at the excitatory synapse, which could be the responsible for the neurotoxic effect described for the Aβ oligomers. The characterization of the interaction between Aβ receptors and Aβ oligomers could help to understand the source of the neurologic damage observed in the brain of the Alzheimer's disease patients.
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Affiliation(s)
- Margarita C Dinamarca
- Centro de Envejecimiento y Regeneración, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile Santiago, Chile
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66
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Reducing amyloid-related Alzheimer's disease pathogenesis by a small molecule targeting filamin A. J Neurosci 2012; 32:9773-84. [PMID: 22815492 DOI: 10.1523/jneurosci.0354-12.2012] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
PTI-125 is a novel compound demonstrating a promising new approach to treating Alzheimer's disease (AD), characterized by neurodegeneration and amyloid plaque and neurofibrillary pathologies. We show that the toxic signaling of amyloid-β(42) (Aβ(42)) by the α7-nicotinic acetylcholine receptor (α7nAChR), which results in tau phosphorylation and formation of neurofibrillary tangles, requires the recruitment of the scaffolding protein filamin A (FLNA). By binding FLNA with high affinity, PTI-125 prevents Aβ(42)'s toxic cascade, decreasing phospho-tau and Aβ aggregates and reducing the dysfunction of α7nAChRs, NMDARs, and insulin receptors. PTI-125 prevents Aβ(42) signaling by drastically reducing its affinity for α7nAChRs and can even dissociate existing Aβ(42)-α7nAChR complexes. Additionally, PTI-125 prevents Aβ-induced inflammatory cytokine release by blocking FLNA recruitment to toll-like receptor 4, illustrating an anti-inflammatory effect. PTI-125's broad spectrum of beneficial effects is demonstrated here in an intracerebroventricular Aβ(42) infusion mouse model of AD and in human postmortem AD brain tissue.
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67
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Lemoine D, Jiang R, Taly A, Chataigneau T, Specht A, Grutter T. Ligand-gated ion channels: new insights into neurological disorders and ligand recognition. Chem Rev 2012; 112:6285-318. [PMID: 22988962 DOI: 10.1021/cr3000829] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Damien Lemoine
- Laboratoire de Biophysicochimie des Récepteurs Canaux, UMR 7199 CNRS, Conception et Application de Molécules Bioactives, Faculté de Pharmacie, Université de Strasbourg , 67400 Illkirch, France
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68
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Kuiper EFE, Nelemans A, Luiten P, Nijholt I, Dolga A, Eisel U. K(Ca)2 and k(ca)3 channels in learning and memory processes, and neurodegeneration. Front Pharmacol 2012; 3:107. [PMID: 22701424 PMCID: PMC3372087 DOI: 10.3389/fphar.2012.00107] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 05/19/2012] [Indexed: 11/13/2022] Open
Abstract
Calcium-activated potassium (KCa) channels are present throughout the central nervous system as well as many peripheral tissues. Activation of KCa channels contribute to maintenance of the neuronal membrane potential and was shown to underlie the afterhyperpolarization (AHP) that regulates action potential firing and limits the firing frequency of repetitive action potentials. Different subtypes of KCa channels were anticipated on the basis of their physiological and pharmacological profiles, and cloning revealed two well defined but phylogenetic distantly related groups of channels. The group subject of this review includes both the small conductance KCa2 channels (KCa2.1, KCa2.2, and KCa2.3) and the intermediate-conductance (KCa3.1) channel. These channels are activated by submicromolar intracellular Ca2+ concentrations and are voltage independent. Of all KCa channels only the KCa2 channels can be potently but differentially blocked by the bee-venom apamin. In the past few years modulation of KCa channel activation revealed new roles for KCa2 channels in controlling dendritic excitability, synaptic functioning, and synaptic plasticity. Furthermore, KCa2 channels appeared to be involved in neurodegeneration, and learning and memory processes. In this review, we focus on the role of KCa2 and KCa3 channels in these latter mechanisms with emphasis on learning and memory, Alzheimer’s disease and on the interplay between neuroinflammation and different neurotransmitters/neuromodulators, their signaling components and KCa channel activation.
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Affiliation(s)
- Els F E Kuiper
- Molecular Neurobiology, University of Groningen Groningen, Netherlands
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69
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Age-dependent rescue by simvastatin of Alzheimer's disease cerebrovascular and memory deficits. J Neurosci 2012; 32:4705-15. [PMID: 22492027 DOI: 10.1523/jneurosci.0169-12.2012] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Alzheimer's disease (AD) is now established as a progressive compromise not only of the neurons but also of the cerebral vasculature. Increasing evidence also indicates that cerebrovascular dysfunction may be a key or an aggravating pathogenic factor in AD, emphasizing the importance to properly control this deficit when aiming for effective therapy. Here, we report that simvastatin (3-6 months, 40 mg/kg/d) completely rescued cerebrovascular reactivity, basal endothelial nitric oxide synthesis, and activity-induced neurometabolic and neurovascular coupling in adult (6 months) and aged (12 months) transgenic mice overexpressing the Swedish and Indiana mutations of the human amyloid precursor protein (AD mice). Remarkably, simvastatin fully restored short- and long-term memory in adult, but not in aged AD mice. These beneficial effects occurred without any decreasing effect of simvastatin on brain amyloid-β (Aβ) levels or plaque load. However, in AD mice with recovered memory, protein levels of the learning- and memory-related immediate early genes c-Fos and Egr-1 were normalized or upregulated in hippocampal CA1 neurons, indicative of restored neuronal function. In contrast, the levels of phospholipase A2, enkephalin, PSD-95, synaptophysin, or glutamate NMDA receptor subunit type 2B were either unaltered in AD mice or unaffected by treatment. These findings disclose new sites of action for statins against Aβ-induced neuronal and cerebrovascular deficits that could be predictive of therapeutic benefit in AD patients. They further indicate that simvastatin and, possibly, other brain penetrant statins bear high therapeutic promise in early AD and in patients with vascular diseases who are at risk of developing AD.
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70
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Hritcu L, Cioanca O, Hancianu M. Effects of lavender oil inhalation on improving scopolamine-induced spatial memory impairment in laboratory rats. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2012; 19:529-534. [PMID: 22402245 DOI: 10.1016/j.phymed.2012.02.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 12/13/2011] [Accepted: 02/04/2012] [Indexed: 05/31/2023]
Abstract
Lavender is reported to be an effective medical plant in treating inflammation, depression, stress and mild anxiety in Europe and the USA. The present study investigated the effects of two different lavender essential oils from Lavandula angustifolia ssp. angustifolia Mill. (Lamiaceae) and Lavandula hybrida Rev. (Lamiaceae) on neurological capacity of male Wistar rats subjected to scopolamine (0.7mg/kg)-induced dementia rat model. Chronic exposures to lavender essential oils (daily, for 7 continuous days) significantly reduced anxiety-like behavior and inhibited depression in elevated plus-maze and forced swimming tests, suggesting anxiolytic and antidepressant activity. Also, spatial memory performance in Y-maze and radial arm-maze tasks was improved, suggesting positive effects on memory formation. Taken together, multiple exposures to lavender essential oils could effectively reverse spatial memory deficits induced by dysfunction of the cholinergic system in the rat brain and might provide an opportunity for management neurological abnormalities in dementia conditions.
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Affiliation(s)
- Lucian Hritcu
- Department of Biology, Alexandru Ioan Cuza University, Bd. Carol I, No. 11, Iasi 700506, Romania.
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71
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Hunter S, Brayne C. Relationships between the amyloid precursor protein and its various proteolytic fragments and neuronal systems. Alzheimers Res Ther 2012; 4:10. [PMID: 22498202 PMCID: PMC3583130 DOI: 10.1186/alzrt108] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease and in its familial form is associated with mutations in the amyloid precursor protein (APP) and the presenilins (PSs). Much data regarding the interactions of APP, its proteolytic fragments and PS have been generated, expanding our understanding of the roles of these proteins in mechanisms underlying cognitive function and revealing many complex relationships with wide ranging cellular systems. In this review, we examine the multiple interactions of APP and its proteolytic fragments with other neuronal systems in terms of feedback loops and use these relationships to build a map. We highlight the complexity involved in the APP proteolytic system and discuss alternative perspectives on the roles of APP and its proteolytic fragments in dynamic processes associated with disease progression in AD. We highlight areas where data are missing and suggest potential confounding factors. We suggest that a systems biology approach enhances representations of the data and may be more useful in modelling both normal cognition and disease processes.
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Affiliation(s)
- Sally Hunter
- Institute of Public Health, University of Cambridge, Forvie site, Robinson Way, Cambridge CB2 0SR, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Forvie site, Robinson Way, Cambridge CB2 0SR, UK
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72
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Selective degeneration of septal and hippocampal GABAergic neurons in a mouse model of amyloidosis and tauopathy. Neurobiol Dis 2012; 47:1-12. [PMID: 22426397 DOI: 10.1016/j.nbd.2012.03.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 01/30/2012] [Accepted: 03/01/2012] [Indexed: 01/16/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by brain accumulation of amyloid-β peptide and neurofibrillary tangles, which are believed to initiate a pathological cascade that results in progressive impairment of cognitive functions and eventual neuronal death. To obtain a mouse model displaying the typical AD histopathology of amyloidosis and tauopathy, we generated a triple-transgenic mouse line (TauPS2APP) by overexpressing human mutations of the amyloid precursor protein, presenilin2 and tau genes. Stereological analysis of TauPS2APP mice revealed significant neurodegeneration of GABAergic septo-hippocampal projection neurons as well as their target cells, the GABAergic hippocampal interneurons. In contrast, the cholinergic medial septum neurons remained unaffected. Moreover, the degeneration of hippocampal GABAergic interneurons was dependent on the hippocampal subfield and interneuronal subtype investigated, whereby the dentate gyrus and the NPY-positive interneurons, respectively, were most strongly affected. Neurodegeneration was also accompanied by a change in the mRNA expression of markers for inhibitory interneurons. In line with the loss of inhibitory neurons, we observed functional changes in TauPS2APP mice relative to WT mice, with strongly enhanced long-term potentiation in the medial-perforant pathway input to the dentate gyrus, and stereotypic hyperactivity. Our data indicate that inhibitory neurons are the targets of neurodegeneration in a mouse model of amyloidosis and tauopathy, thus pointing to a possible role of the inhibitory network in the pathophysiological and functional cascade of Alzheimer's disease.
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73
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NR2B-Containing NMDA Receptors Expression and Their Relationship to Apoptosis in Hippocampus of Alzheimer’s Disease-Like Rats. Neurochem Res 2012; 37:1420-7. [DOI: 10.1007/s11064-012-0726-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 01/30/2012] [Accepted: 02/10/2012] [Indexed: 11/26/2022]
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74
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Benilova I, Karran E, De Strooper B. The toxic Aβ oligomer and Alzheimer's disease: an emperor in need of clothes. Nat Neurosci 2012; 15:349-57. [DOI: 10.1038/nn.3028] [Citation(s) in RCA: 1435] [Impact Index Per Article: 119.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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75
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Neuronal receptors as targets for the action of amyloid-beta protein (Aβ) in the brain. Expert Rev Mol Med 2012; 14:e2. [PMID: 22261393 DOI: 10.1017/s1462399411002134] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Accumulation of neurotoxic soluble amyloid-beta protein (Aβ) oligomers in the brains of patients with Alzheimer disease (AD) and their role in AD pathogenesis have emerged as topics of considerable interest in recent years. Soluble Aβ oligomers impair synaptic and neuronal function, leading to neurodegeneration that is clinically manifested by memory and cognitive dysfunction. The precise mechanisms whereby Aβ oligomers cause neurotoxicity remain unknown. Emerging insights into the mechanistic link between neuronal receptors and soluble Aβ oligomers highlight the potential role of these receptors in Aβ-mediated neurotoxicity in AD. The current review focuses on studies describing interactions between soluble Aβ oligomers and neuronal receptors, and their role in AD pathogenesis. Furthermore, these studies provide insight into potential therapies for AD using compounds directed at putative target receptors for the action of Aβ in the central nervous system. We focus on interactions of Aβ with subtypes of acetylcholine and glutamatergic receptors. Additionally, neuronal receptors such as insulin, amylin and receptor for advanced glycation end products could be potential targets for soluble Aβ-oligomer-mediated neurotoxicity. Aβ interactions with other receptors such as the p75 neurotrophin receptors, which are highly expressed on cholinergic basal forebrain neurons lost in AD, are also highlighted.
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76
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Sadleir KR, Vassar R. Cdk5 protein inhibition and Aβ42 increase BACE1 protein level in primary neurons by a post-transcriptional mechanism: implications of CDK5 as a therapeutic target for Alzheimer disease. J Biol Chem 2012; 287:7224-35. [PMID: 22223639 DOI: 10.1074/jbc.m111.333914] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The β-secretase enzyme BACE1 initiates production of the amyloid-β (Aβ) peptide that comprises plaques in Alzheimer disease (AD) brain. BACE1 levels are increased in AD, potentially accelerating Aβ generation, but the mechanisms of BACE1 elevation are not fully understood. Cdk5/p25 has been implicated in neurodegeneration and BACE1 regulation, suggesting therapeutic Cdk5 inhibition for AD. In addition, caspase 3 has been implicated in BACE1 elevation. Here, we show that the Cdk5 level and p25:p35 ratio were elevated and correlated with BACE1 level in brains of AD patients and 5XFAD transgenic mice. Mouse primary cortical neurons treated with Aβ42 oligomers had increased BACE1 level and p25:p35 ratio. Surprisingly, the Aβ42-induced BACE1 elevation was not blocked by Cdk5 inhibitors CP68130 and roscovitine, and instead the BACE1 level was increased greater than with Aβ42 treatment alone. Moreover, Cdk5 inhibitors alone elevated BACE1 in a time- and dose-dependent manner that coincided with increased caspase 3 cleavage and decreased Cdk5 level. Caspase 3 inhibitor benzyloxycarbonyl-VAD failed to prevent the Aβ42-induced BACE1 increase. Further experiments suggested that the Aβ42-induced BACE1 elevation was the result of a post-transcriptional mechanism. We conclude that Aβ42 may increase the BACE1 level independently of either Cdk5 or caspase 3 and that Cdk5 inhibition for AD may cause BACE1 elevation, a potentially negative therapeutic outcome.
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Affiliation(s)
- Katherine R Sadleir
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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77
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Soheili M, Tavirani MR, Salami M. Clearance of Amyloid Beta Plaques from Brain of Alzheimeric Rats by Lavandula angustifolia. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/nm.2012.34044] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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78
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Hansen N. Action mechanisms of transcranial direct current stimulation in Alzheimer's disease and memory loss. Front Psychiatry 2012; 3:48. [PMID: 22615703 PMCID: PMC3351674 DOI: 10.3389/fpsyt.2012.00048] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 04/24/2012] [Indexed: 01/01/2023] Open
Abstract
The pharmacological treatment of Alzheimer's disease (AD) is often limited and accompanied by drug side effects. Thus alternative therapeutic strategies such as non-invasive brain stimulation are needed. Few studies have demonstrated that transcranial direct current stimulation (tDCS), a method of neuromodulation with consecutive robust excitability changes within the stimulated cortex area, is beneficial in AD. There is also evidence that tDCS enhances memory function in cognitive rehabilitation in depressive patients, Parkinson's disease, and stroke. tDCS improves working and visual recognition memory in humans and object-recognition learning in the elderly. AD's neurobiological mechanisms comprise changes in neuronal activity and the cerebral blood flow (CBF) caused by altered microvasculature, synaptic dysregulation from ß-amyloid peptide accumulation, altered neuromodulation via degenerated modulatory amine transmitter systems, altered brain oscillations, and changes in network connectivity. tDCS alters (i) neuronal activity and (ii) human CBF, (iii) has synaptic and non-synaptic after-effects (iv), can modify neurotransmitters polarity-dependently, (v) and alter oscillatory brain activity and (vi) functional connectivity patterns in the brain. It thus is reasonable to use tDCS as a therapeutic instrument in AD as it improves cognitive function in manner based on a disease mechanism. Moreover, it could prove valuable in other types of dementia. Future large-scale clinical and mechanism-oriented studies may enable us to identify its therapeutic validity in other types of demential disorders.
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Affiliation(s)
- Niels Hansen
- Department of Neurophysiology, Ruhr University Bochum Bochum, Germany
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79
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Scott Bitner R. Cyclic AMP response element-binding protein (CREB) phosphorylation: a mechanistic marker in the development of memory enhancing Alzheimer's disease therapeutics. Biochem Pharmacol 2011; 83:705-14. [PMID: 22119240 DOI: 10.1016/j.bcp.2011.11.009] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 11/07/2011] [Accepted: 11/09/2011] [Indexed: 10/15/2022]
Abstract
CREB-mediated transcription can be initiated by membrane receptor stimulation and subsequent activation of intracellular pathways to the cell nucleus, and has been described as a molecular switch required for learning and memory. While CREB dimers are thought to be constitutively bound to response elements on DNA under basal conditions, it is CREB phosphorylation that is believed to be responsible for transcriptional activation leading to gene products such as BDNF that play a key role in synaptic plasticity and cognitive function. Conversely, preclinical and clinical findings now suggest that impaired CREB phosphorylation may be a pathological component in neurodegenerative disorders, in particular Alzheimer's disease (AD). In this regard, pharmacological-induced CREB phosphorylation in brain regions associated with cognition, i.e. cortex and hippocampus may represent a mechanistic basis for the development of novel AD therapeutics. The purpose of this commentary is to describe an experimental strategy to biochemically characterize the pharmacological induction of CREB phosphorylation as a mechanistic marker across different pharmacological classes of compounds for the potential treatment of AD that include: α7 nicotinic agonists, H3 antagonists and 11β HSD1 inhibitors.
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Affiliation(s)
- R Scott Bitner
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064, United States.
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80
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Crouch PJ, Savva MS, Hung LW, Donnelly PS, Mot AI, Parker SJ, Greenough MA, Volitakis I, Adlard PA, Cherny RA, Masters CL, Bush AI, Barnham KJ, White AR. The Alzheimer’s therapeutic PBT2 promotes amyloid-β degradation and GSK3 phosphorylation via a metal chaperone activity. J Neurochem 2011; 119:220-30. [DOI: 10.1111/j.1471-4159.2011.07402.x] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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81
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Montgomery SL, Mastrangelo MA, Habib D, Narrow WC, Knowlden SA, Wright TW, Bowers WJ. Ablation of TNF-RI/RII expression in Alzheimer's disease mice leads to an unexpected enhancement of pathology: implications for chronic pan-TNF-α suppressive therapeutic strategies in the brain. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:2053-70. [PMID: 21835156 DOI: 10.1016/j.ajpath.2011.07.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 06/28/2011] [Accepted: 07/01/2011] [Indexed: 11/15/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by severe memory loss and cognitive impairment. Neuroinflammation, including the extensive production of pro-inflammatory molecules and the activation of microglia, has been implicated in the disease process. Tumor necrosis factor (TNF)-α, a prototypic pro-inflammatory cytokine, is elevated in AD, is neurotoxic, and colocalizes with amyloid plaques in AD animal models and human brains. We previously demonstrated that the expression of TNF-α is increased in AD mice at ages preceding the development of hallmark amyloid and tau pathological features and that long-term expression of this cytokine in these mice leads to marked neuronal death. Such observations suggest that TNF-α signaling promotes AD pathogenesis and that therapeutics suppressing this cytokine's activity may be beneficial. To dissect TNF-α receptor signaling requirements in AD, we generated triple-transgenic AD mice (3xTg-AD) lacking both TNF-α receptor 1 (TNF-RI) and 2 (TNF-RII), 3xTg-ADxTNF-RI/RII knock out, the cognate receptors of TNF-α. These mice exhibit enhanced amyloid and tau-related pathological features by the age of 15 months, in stark contrast to age-matched 3xTg-AD counterparts. Moreover, 3xTg-ADxTNF-RI/RII knock out-derived primary microglia reveal reduced amyloid-β phagocytic marker expression and phagocytosis activity, indicating that intact TNF-α receptor signaling is critical for microglial-mediated uptake of extracellular amyloid-β peptide pools. Overall, our results demonstrate that globally ablated TNF receptor signaling exacerbates pathogenesis and argues against long-term use of pan-anti-TNF-α inhibitors for the treatment of AD.
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MESH Headings
- Adaptor Proteins, Signal Transducing/metabolism
- Aging/pathology
- Alzheimer Disease/drug therapy
- Alzheimer Disease/metabolism
- Alzheimer Disease/pathology
- Alzheimer Disease/physiopathology
- Amyloid/metabolism
- Amyloid beta-Protein Precursor/genetics
- Animals
- Brain/metabolism
- Brain/pathology
- CA1 Region, Hippocampal/pathology
- CA1 Region, Hippocampal/physiopathology
- CA3 Region, Hippocampal/pathology
- CA3 Region, Hippocampal/physiopathology
- Calcium-Binding Proteins/metabolism
- Crosses, Genetic
- Female
- Humans
- Lipopolysaccharide Receptors/metabolism
- Long-Term Potentiation
- Male
- Mice
- Mice, Knockout
- Microfilament Proteins/metabolism
- Microglia/metabolism
- Microglia/pathology
- Phagocytosis
- Receptors, Tumor Necrosis Factor, Type I/deficiency
- Receptors, Tumor Necrosis Factor, Type I/metabolism
- Receptors, Tumor Necrosis Factor, Type II/deficiency
- Receptors, Tumor Necrosis Factor, Type II/metabolism
- Synapses/metabolism
- Transgenes/genetics
- Tumor Necrosis Factor-alpha/antagonists & inhibitors
- Tumor Necrosis Factor-alpha/metabolism
- tau Proteins/genetics
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Affiliation(s)
- Sara L Montgomery
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY14642, USA.
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82
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Khandelwal PJ, Herman AM, Moussa CEH. Inflammation in the early stages of neurodegenerative pathology. J Neuroimmunol 2011; 238:1-11. [PMID: 21820744 DOI: 10.1016/j.jneuroim.2011.07.002] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 07/09/2011] [Accepted: 07/12/2011] [Indexed: 12/12/2022]
Abstract
Inflammation is secondary to protein accumulation in neurodegenerative diseases, including Alzheimer's, Parkinson's and Amyotrophic Lateral Sclerosis. Emerging evidence indicate sustained inflammatory responses, involving microglia and astrocytes in animal models of neurodegeneration. It is unknown whether inflammation is beneficial or detrimental to disease progression and how inflammatory responses are induced within the CNS. Persistence of an inflammatory stimulus or failure to resolve sustained inflammation can result in pathology, thus, mechanisms that counteract inflammation are indispensable. Here we review studies on inflammation mediated by innate and adaptive immunity in the early stages of neurodegeneration and highlight important areas for future investigation.
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Affiliation(s)
- Preeti J Khandelwal
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20007, USA
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83
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Jung JH, An K, Kwon OB, Kim HS, Kim JH. Pathway-specific alteration of synaptic plasticity in Tg2576 mice. Mol Cells 2011; 32:197-201. [PMID: 21638202 PMCID: PMC3887667 DOI: 10.1007/s10059-011-0077-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 05/25/2011] [Accepted: 05/25/2011] [Indexed: 12/12/2022] Open
Abstract
Various animal models of Alzheimer disease (AD) are characterized by deficits in spatial memory that are causally related to altered synaptic function and impairment of long-term potentiation (LTP) in the hippocampus. In Tg2576 AD mice, we compared LTP in 2 major hippocampal pathways, Schaffer collateral (SC) and mossy fiber (MF) pathways. Whereas LTP was completely abolished in the SC pathway of Tg2576 mice, we found no decrease in LTP induced by stimulation of the MF pathway. In fact, we found that in the MF pathway, LTP was slightly, but significantly, enhanced compared with that in the MF pathway of WT littermates. This pathway-specific impairment of LTP is not attributable to alterations in transmitter release, as indicated by an unaltered paired-pulse ratio. These results suggest that the spatial memory deficits normally seen in AD models arise primarily from LTP impairment at the SC pathway.
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Affiliation(s)
| | | | | | - Hye-sun Kim
- Department of Pharmacology, Seoul National University, College of Medicine, Seoul 110-799, Korea
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84
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Kashani MS, Tavirani MR, Talaei SA, Salami M. Aqueous extract of lavender (Lavandula angustifolia) improves the spatial performance of a rat model of Alzheimer's disease. Neurosci Bull 2011; 27:99-106. [PMID: 21441971 DOI: 10.1007/s12264-011-1149-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVE Alzheimer's disease (AD) is one of the most important neurodegenerative disorders. It is characterized by dementia including deficits in learning and memory. The present study aimed to evaluate the effects of aqueous extract of lavender (Lavandula angustifolia) on spatial performance of AD rats. METHODS Male Wistar rats were first divided into control and AD groups. Rat model of AD was established by intracerebroventricular injection of 10 μg Aβ1-42 20 d prior to administration of the lavender extract. Rats in both groups were then introduced to 2 stages of task learning (with an interval of 20 d) in Morris water maze, each followed by one probe test. After the first stage of spatial learning, control and AD animals received different doses (50, 100 and 200 mg/kg) of the lavender extract. RESULTS In the first stage of experiment, the latency to locate the hidden platform in AD group was significantly higher than that in control group. However, in the second stage of experiment, control and AD rats that received distilled water (vehicle) showed similar performance, indicating that the maze navigation itself could improve the spatial learning of AD animals. Besides, in the second stage of experiment, control and AD rats that received lavender extract administration at different doses (50, 100, and 200 mg/ kg) spent less time locating the platform (except for the AD rats with 50 mg/kg extract treatment), as compared with their counterparts with vehicle treatment, respectively. In addition, lavender extract significantly improved the performance of control and AD rats in the probe test, only at the dose of 200 mg/kg, as compared with their counterparts with vehicle treatment. CONCLUSION The lavender extract can effectively reverse spatial learning deficits in AD rats.
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Affiliation(s)
- Masoud Soheili Kashani
- Proteomics Research Center, Shaheed Beheshti University of Medical Sciences, Tehran, Iran
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85
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Chong SA, Benilova I, Shaban H, De Strooper B, Devijver H, Moechars D, Eberle W, Bartic C, Van Leuven F, Callewaert G. Synaptic dysfunction in hippocampus of transgenic mouse models of Alzheimer's disease: a multi-electrode array study. Neurobiol Dis 2011; 44:284-91. [PMID: 21807097 DOI: 10.1016/j.nbd.2011.07.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 05/19/2011] [Accepted: 07/06/2011] [Indexed: 11/30/2022] Open
Abstract
APP.V717I and Tau.P301L transgenic mice develop Alzheimer's disease pathology comprising important aspects of human disease including increased levels of amyloid peptides, cognitive and motor impairment, amyloid plaques and neurofibrillary tangles. The combined model, APP.V717I×Tau.P301L bigenic mice (biAT mice) exhibit aggravated amyloid and tau pathology with severe cognitive and behavioral defects. In the present study, we investigated early changes in synaptic function in the CA1 and CA3 regions of acute hippocampal slices of young APP.V717I, Tau.P301L and biAT transgenic animals. We have used planar multi-electrode arrays (MEA) and improved methods for simultaneous multi-site recordings from two hippocampal sub-regions. In the CA1 region, long-term potentiation (LTP) was severely impaired in all transgenic animals when compared with age-matched wild-type controls, while basal synaptic transmission and paired-pulse facilitation were minimally affected. In the CA3 region, LTP was normal in Tau.P301L and APP.V717I but clearly impaired in biAT mice. Surprisingly, frequency facilitation in CA3 was significantly enhanced in Tau.P301L mice, while not affected in APP.V717I mice and depressed in biAT mice. The findings demonstrate important synaptic changes that differ considerably in the hippocampal sub-regions already at young age, well before the typical amyloid or tau pathology is evident.
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Affiliation(s)
- Seon-Ah Chong
- Bio-Electronic Systems, Imec, Kapeldreef 75, Leuven, Belgium
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86
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Bicca MA, Figueiredo CP, Piermartiri TC, Meotti FC, Bouzon ZL, Tasca CI, Medeiros R, Calixto JB. The selective and competitive N-methyl-D-aspartate receptor antagonist, (-)-6-phosphonomethyl-deca-hydroisoquinoline-3-carboxylic acid, prevents synaptic toxicity induced by amyloid-β in mice. Neuroscience 2011; 192:631-41. [PMID: 21756976 DOI: 10.1016/j.neuroscience.2011.06.038] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 06/09/2011] [Accepted: 06/10/2011] [Indexed: 10/18/2022]
Abstract
The toxicity of amyloid β (Aβ) is highly associated with Alzheimer's disease (AD), which has a high incidence in elderly people worldwide. While the current treatment for moderate and severe AD includes blockage of the N-methyl-d-aspartate receptor (NMDAR), the molecular mechanisms of its effect are still poorly understood. Herein, we report that a single i.p. administration of the selective and competitive (NMDAR) antagonist LY235959 reduced Aβ neurotoxicity by preventing the down-regulation of glial glutamate transporters (glutamate-aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1)), the decrease in glutamate uptake, and the production of reactive oxygen species (ROS) induced by Aβ(1-40). Importantly, the blockage of NMDAR restored the Aβ(1-40)-induced synaptic dysfunction and cognitive impairment. However, LY235959 failed to prevent the inflammatory response associated with Aβ(1-40) treatment. Altogether, our data indicate that the acute administration of Aβ promotes oxidative stress, a decrease in glutamate transporter expression, and neurotoxicity. Our results reinforce the idea that NMDAR plays a critical regulatory action in Aβ toxicity and they provide further pre-clinical evidence for the potential role of the selective and competitive NMDAR antagonists in the treatment of AD.
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Affiliation(s)
- M A Bicca
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, 88049-900, Florianópolis, Santa Catarina, Brazil
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87
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Proctor DT, Coulson EJ, Dodd PR. Post-synaptic scaffolding protein interactions with glutamate receptors in synaptic dysfunction and Alzheimer's disease. Prog Neurobiol 2011; 93:509-21. [PMID: 21382433 DOI: 10.1016/j.pneurobio.2011.02.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 02/18/2011] [Accepted: 02/24/2011] [Indexed: 11/19/2022]
Abstract
Alzheimer's disease (AD) is characterized clinically by an insidious decline in cognition. Much attention has been focused on proposed pathogenic mechanisms that relate Aβ plaque and neurofibrillary tangle pathology to cognitive symptoms, but compelling evidence now identifies early synaptic loss and dysfunction, which precede plaque and tangle formation, as the more probable initiators of cognitive impairment. Glutamate-mediated transmission is severely altered in AD. Glutamate receptor expression is most markedly altered in regions of the AD brain that show the greatest pathological changes. Signaling via glutamate receptors controls synaptic strength and plasticity, and changes in these parameters are likely to contribute to memory and cognitive deficits in AD. Glutamate receptor expression and activity are modulated by interactions with post-synaptic scaffolding proteins that augment the strength and direction of signal cascades initiated by glutamate receptor activity. Scaffold proteins offer promising targets for more focused and effective drug therapy. In consequence, interest is developing into the roles these proteins play in neurological disease. In this review we discuss disruptions to excitatory neurotransmission at the level of glutamate receptor-post-synaptic scaffolding protein interactions that may contribute to synaptic dysfunction in AD.
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Affiliation(s)
- Dustin T Proctor
- School of Chemistry and Molecular Biosciences, Molecular Biosciences Building #76, Coopers Road, St Lucia campus, University of Queensland, Brisbane 4072, Australia
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88
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Majlessi N, Choopani S, Kamalinejad M, Azizi Z. Amelioration of amyloid β-induced cognitive deficits by Zataria multiflora Boiss. essential oil in a rat model of Alzheimer's disease. CNS Neurosci Ther 2011; 18:295-301. [PMID: 22070531 DOI: 10.1111/j.1755-5949.2011.00237.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
INTRODUCTION The limitations of current Alzheimer's disease (AD) therapeutics have prompted investigation into innovative therapeutics focused on antiinflammatory, antioxidant, and neuroprotective agents including those from medicinal plants. Numerous plants have been tested for their potential for alleviating symptoms of AD. AIMS Zataria multiflora Boiss. (ZM) a member of Lamiaceae family has been used in Iranian traditional medicine for its beneficial effects on mental abilities. Therefore, the effect of its essential oil was evaluated in a rat model of AD. METHODS Amyloid β-protein (Aβ) fragment 25-35 was injected bilaterally in the CA1 region of rats hippocampus and the effect of different doses of ZM essential oil (50, 100, or 200 μL/kg) on cognitive function was investigated in the Morris water maze. Acute toxicity of the essential oil was also studied. RESULTS The results showed increases in escape latency, traveled distance, heading angle, and decreases in target quadrant entries in Aβ-received groups as compared to the control group. This impairment was reversed by ZM essential oil. The results of acute toxicity testing revealed that the calculated LD50 (1264.9 μL/kg) is much higher than the therapeutic dose (100 μL/kg). CONCLUSIONS It seems that antioxidant, antiinflammatory, and anticholinesterase activities of ZM or its main constituents might contribute to its beneficial effects in this model. Our findings suggest that ZM may be a potentially valuable source of natural therapeutic agents for the treatment of AD. However, further investigations are necessary to establish its clinical efficacy and potential toxicity, before any recommendations concerning its use as a medication in the treatment of AD.
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Affiliation(s)
- Nahid Majlessi
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran.
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89
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Li H, Rao A, Hogan PG. Interaction of calcineurin with substrates and targeting proteins. Trends Cell Biol 2011; 21:91-103. [PMID: 21115349 PMCID: PMC3244350 DOI: 10.1016/j.tcb.2010.09.011] [Citation(s) in RCA: 272] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 09/15/2010] [Accepted: 09/27/2010] [Indexed: 12/18/2022]
Abstract
Calcineurin is a calcium activated protein phosphatase with a major role in calcium signaling in diverse cells and organs and clinical importance as the target of the immunosuppressive drugs cyclosporin A and tacrolimus (FK506). Cell biology studies have focused mainly on the role of calcineurin in transcriptional signaling. Calcium entry in response to extracellular stimuli results in calcineurin activation, and signal transmission from the cytosol into the nucleus through dephosphorylation and nuclear translocation of the transcription factor nuclear factor of activated T cells (NFAT). This initiates a cascade of transcriptional events involved in physiological and developmental processes. Molecular analyses of the calcineurin-NFAT interaction have been extended recently to encompass the interaction of calcineurin with other substrates, targeting proteins and regulators of calcineurin activity. These studies have increased our understanding of how this essential calcium activated enzyme orchestrates intracellular events in cooperation with other signaling pathways, and have suggested a link between altered calcineurin signaling and the developmental anomalies of Down syndrome.
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Affiliation(s)
- Huiming Li
- Immune Disease Institute and Program in Cellular and Molecular Medicine, Children's Hospital, Boston, MA 02115, USA
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90
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Therapeutic potential of some stress mediators in early Alzheimer's disease. Exp Gerontol 2011; 46:170-3. [DOI: 10.1016/j.exger.2010.09.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 09/07/2010] [Accepted: 09/09/2010] [Indexed: 01/19/2023]
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91
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Taghizadeh M, Djazayery A, Salami M, Eshraghian MR, Zavareh SAT. Vitamin-D-Free Regimen Intensifies the Spatial Learning Deficit in Alzheimer's Disease. Int J Neurosci 2011; 121:16-24. [DOI: 10.3109/00207454.2010.523132] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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92
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Balducci C, Forloni G. APP transgenic mice: their use and limitations. Neuromolecular Med 2010; 13:117-37. [PMID: 21152995 DOI: 10.1007/s12017-010-8141-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 11/20/2010] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease is the most widespread form of dementia. Its histopathological hallmarks include vascular and extracellular β-amyloid (Aβ) deposition and intraneuronal neurofibrillary tangles (NFTs). Gradual decline of cognitive functions linked to progressive synaptic loss makes patients unable to store new information in the earlier stages of the pathology, later becoming completely dependent because they are unable to do even elementary daily life actions. Although more than a hundred years have passed since Alois Alzheimer described the first case of AD, and despite many years of intense research, there are still many crucial points to be discovered in the neuropathological pathway. The development of transgenic mouse models engineered with overexpression of the amyloid precursor protein carrying familial AD mutations has been extremely useful. Transgenic mice present the hallmarks of the pathology, and histological and behavioural examination supports the amyloid hypothesis. As in human AD, extracellular Aβ deposits surrounded by activated astrocytes and microglia are typical features, together with synaptic and cognitive defects. Although animal models have been widely used, they are still being continuously developed in order to recapitulate some missing aspects of the disease. For instance, AD therapeutic agents tested in transgenic mice gave encouraging results which, however, were very disappointing in clinical trials. Neuronal cell death and NFTs typical of AD are much harder to replicate in these mice, which thus offer a fundamental but still imperfect tool for understanding and solving dementia pathology.
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Affiliation(s)
- Claudia Balducci
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, via G. La Masa, 19, 20156, Milan, Italy.
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93
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Jürgensen S, Antonio LL, Mussi GEA, Brito-Moreira J, Bomfim TR, De Felice FG, Garrido-Sanabria ER, Cavalheiro ÉA, Ferreira ST. Activation of D1/D5 dopamine receptors protects neurons from synapse dysfunction induced by amyloid-beta oligomers. J Biol Chem 2010; 286:3270-6. [PMID: 21115476 DOI: 10.1074/jbc.m110.177790] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Soluble oligomers of the amyloid-β peptide (AβOs) accumulate in the brains of Alzheimer disease (AD) patients and are implicated in synapse failure and early memory loss in AD. AβOs have been shown to impact synapse function by inhibiting long term potentiation, facilitating the induction of long term depression and inducing internalization of both AMPA and NMDA glutamate receptors, critical players in plasticity mechanisms. Because activation of dopamine D1/D5 receptors plays important roles in memory circuits by increasing the insertion of AMPA and NMDA receptors at synapses, we hypothesized that selective activation of D1/D5 receptors could protect synapses from the deleterious action of AβOs. We show that SKF81297, a selective D1/D5 receptor agonist, prevented the reduction in surface levels of AMPA and NMDA receptors induced by AβOs in hippocampal neurons in culture. Protection by SKF81297 was abrogated by the specific D1/D5 antagonist, SCH23390. Levels of AMPA receptor subunit GluR1 phosphorylated at Ser(845), which regulates AMPA receptor association with the plasma membrane, were reduced in a calcineurin-dependent manner in the presence of AβOs, and treatment with SKF81297 prevented this reduction. Establishing the functional relevance of these findings, SKF81297 blocked the impairment of long term potentiation induced by AβOs in hippocampal slices. Results suggest that D1/D5 receptors may be relevant targets for development of novel pharmacological approaches to prevent synapse failure in AD.
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Affiliation(s)
- Sofia Jürgensen
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro RJ 1944-590, Brazil
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94
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NMDA-mediated Ca(2+) influx drives aberrant ryanodine receptor activation in dendrites of young Alzheimer's disease mice. J Neurosci 2010; 30:12128-37. [PMID: 20826675 DOI: 10.1523/jneurosci.2474-10.2010] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Deficits in synaptic function, particularly through NMDA receptors (NMDARs), are linked to late-stage cognitive impairments in Alzheimer's disease (AD). At earlier disease stages, however, there is evidence for altered endoplasmic reticulum (ER) calcium signaling in human cases and in neurons from AD mouse models. Despite the fundamental importance of calcium to synaptic function, neither the extent of ER calcium dysregulation in dendrites nor its interaction with synaptic function in AD pathophysiology is known. Identifying the mechanisms underlying early synaptic calcium dysregulation in AD pathogenesis is likely a key component to understanding, and thereby preventing, the synapse loss and downstream cognitive impairments. Using two-photon calcium imaging, flash photolysis of caged glutamate, and patch-clamp electrophysiology in cortical brain slices, we examined interactions between synaptically and ER-evoked calcium release at glutamatergic synapses in young AD transgenic mice. We found increased ryanodine receptor-evoked calcium signals within dendritic spine heads, dendritic processes, and the soma of pyramidal neurons from 3xTg-AD and TAS/TPM AD mice relative to NonTg controls. In addition, synaptically evoked postsynaptic calcium responses were larger in the AD strains, as were calcium signals generated from NMDAR activation. However, calcium responses triggered by back-propagating action potentials were not different. Concurrent activation of ryanodine receptors (RyRs) with either synaptic or NMDAR stimulation generated a supra-additive calcium response in the AD strains, suggesting an aberrant calcium-induced calcium release (CICR) effect within spines and dendrites. We propose that presenilin-linked disruptions in RyR signaling and subsequent CICR via NMDAR-mediated calcium influx alters synaptic function and serves as an early pathogenic factor in AD.
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95
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Mouse models of neurological disorders—A comparison of heritable and acquired traits. Biochim Biophys Acta Mol Basis Dis 2010; 1802:785-95. [DOI: 10.1016/j.bbadis.2010.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 05/17/2010] [Accepted: 05/19/2010] [Indexed: 01/17/2023]
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96
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Kuzyk A, Kastyak M, Agrawal V, Gallant M, Sivakumar G, Rak M, Del Bigio MR, Westaway D, Julian R, Gough KM. Association among amyloid plaque, lipid, and creatine in hippocampus of TgCRND8 mouse model for Alzheimer disease. J Biol Chem 2010; 285:31202-7. [PMID: 20682779 DOI: 10.1074/jbc.m110.142174] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Amyloid peptide (Aβ) aggregation in the brain is a characteristic feature of Alzheimer disease (AD). Previously, we reported the discovery of focally elevated creatine deposits in brain tissue from TgCRND8 mice, which express double mutant (K670N/M671L and V717F) amyloid protein precursor. In this study, frozen hippocampal tissue sections from 5-, 8-, 11-, 14-, and 17-month old TgCRND8 and littermate control mice were examined with Fourier transform infrared microspectroscopy to explore the distribution of lipid, creatine, and dense core plaque deposits. Lipid distribution throughout the hippocampus was similar in transgenic (Tg) and non-Tg littermates at all ages. Dense core plaques were always found to lie within a thin (30-50 μm) lipid envelope, confirmed by imaging through serial sections. Creatine deposits were found in all TgCRND8 mice; the extent of deposition increased with age. Minor creatine deposits appeared in the oldest littermate controls. Distribution in the serial sections showed moderate correlation between layers, slightly disturbed by the freeze/thaw process. Creatine deposits in Tg mice were not specifically co-localized with plaques or lipid halos. The dimension of the lipid envelope is comparable with that of the diffuse halo of nonaggregated amyloid, implying a dynamic association in vivo, postulated to have a significant role in the evolving neurotoxicity.
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Affiliation(s)
- Alexandra Kuzyk
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
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97
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Zhao Z, Zhao S, Xu N, Yu C, Guan S, Liu X, Huang L, Liao W, Jia W. Lovastatin improves neurological outcome after nucleus basalis magnocellularis lesion in rats. Neuroscience 2010; 167:954-63. [DOI: 10.1016/j.neuroscience.2010.02.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Revised: 02/13/2010] [Accepted: 02/19/2010] [Indexed: 12/15/2022]
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98
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Tran TT, Srivareerat M, Alkadhi KA. Chronic psychosocial stress accelerates impairment of long-term memory and late-phase long-term potentiation in an at-risk model of Alzheimer's disease. Hippocampus 2010; 21:724-32. [PMID: 20865724 DOI: 10.1002/hipo.20790] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2010] [Indexed: 01/05/2023]
Abstract
Although it is generally agreed that Aβ contributes to the pathogenesis of AD, its precise role in AD and the reason for the varying intensity and time of onset of the disease have not been elucidated. In addition to genetic factors, environmental issues such as stress may also play a critical role in the etiology of AD. This study examined the effect of chronic psychosocial stress in an at-risk (treatment with a subpathogenic dose of Aβ; "subAβ") rat model of AD on long-term memory by three techniques: memory tests in the radial arm water maze, electrophysiological recordings of synaptic plasticity in anesthetized rats, and immunoblot analysis of learning- and long-term memory-related signaling molecules. Chronic psychosocial stress was induced using a rat intruder model. The subAβ rat model of AD was induced by continuous infusion of 160 pmol/day Aβ(1-42) via a 14-day i.c.v. osmotic pump. All tests showed that subAβ rats were not different from control rats. Result from behavioral tests and electrophysiological recordings showed that infusion of subAβ in chronically stressed rats (stress/subAβ group) caused significant impairment of cognitive functions and late-phase long-term potentiation (L-LTP). Molecular analysis of various signaling molecules after expression of L-LTP, revealed an increase in the levels of p-CREB in control, stress, and subAβ rats, but not in the stress/subAβ rats. These findings suggest that the chronic stress-induced molecular alteration may accelerate the impairment of cognition and synaptic plasticity in individuals "at-risk" for AD.
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Affiliation(s)
- Trinh T Tran
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, College of Pharmacy, Texas
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99
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Glass CK, Saijo K, Winner B, Marchetto MC, Gage FH. Mechanisms underlying inflammation in neurodegeneration. Cell 2010; 140:918-34. [PMID: 20303880 DOI: 10.1016/j.cell.2010.02.016] [Citation(s) in RCA: 2518] [Impact Index Per Article: 179.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 01/25/2010] [Accepted: 02/05/2010] [Indexed: 02/08/2023]
Abstract
Inflammation is associated with many neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. In this Review, we discuss inducers, sensors, transducers, and effectors of neuroinflammation that contribute to neuronal dysfunction and death. Although inducers of inflammation may be generated in a disease-specific manner, there is evidence for a remarkable convergence in the mechanisms responsible for the sensing, transduction, and amplification of inflammatory processes that result in the production of neurotoxic mediators. A major unanswered question is whether pharmacological inhibition of inflammation pathways will be able to safely reverse or slow the course of disease.
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Affiliation(s)
- Christopher K Glass
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, 92093, USA.
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100
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Abstract
The cause(s) of sporadic Alzheimer’s disease (sAD) are complex and currently poorly understood. They likely result from a combination of genetic, environmental, proteomic and lipidomic factors that crucially occur only in the aged brain. Age-related changes in calcium levels and dynamics have the potential to increase the production and accumulation of both amyloid-β peptide (Aβ) and τ pathologies in the AD brain, although these two pathologies themselves can induce calcium dyshomeostasis, particularly at synaptic membranes. This review discuses the evidence for a role for calcium dyshomeostasis in the initiation of pathology, as well as the evidence for these pathologies themselves disrupting normal calcium homeostasis, which lead to synaptic and neuronal dysfunction, synaptotoxicity and neuronal loss, underlying the dementia associated with the disease.
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Affiliation(s)
- Kim N Green
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697-4545, USA.
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