251
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Montoliu-Gaya L, Mulder SD, Herrebout MA, Baayen JC, Villegas S, Veerhuis R. Aβ-oligomer uptake and the resulting inflammatory response in adult human astrocytes are precluded by an anti-Aβ single chain variable fragment in combination with an apoE mimetic peptide. Mol Cell Neurosci 2018; 89:49-59. [DOI: 10.1016/j.mcn.2018.03.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/30/2018] [Accepted: 03/31/2018] [Indexed: 10/17/2022] Open
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252
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Lanke V, Moolamalla STR, Roy D, Vinod PK. Integrative Analysis of Hippocampus Gene Expression Profiles Identifies Network Alterations in Aging and Alzheimer's Disease. Front Aging Neurosci 2018; 10:153. [PMID: 29875655 PMCID: PMC5974201 DOI: 10.3389/fnagi.2018.00153] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 05/04/2018] [Indexed: 01/22/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder contributing to rapid decline in cognitive function and ultimately dementia. Most cases of AD occur in elderly and later years. There is a growing need for understanding the relationship between aging and AD to identify shared and unique hallmarks associated with the disease in a region and cell-type specific manner. Although genomic studies on AD have been performed extensively, the molecular mechanism of disease progression is still not clear. The major objective of our study is to obtain a higher-order network-level understanding of aging and AD, and their relationship using the hippocampal gene expression profiles of young (20-50 years), aging (70-99 years), and AD (70-99 years). The hippocampus is vulnerable to damage at early stages of AD and altered neurogenesis in the hippocampus is linked to the onset of AD. We combined the weighted gene co-expression network and weighted protein-protein interaction network-level approaches to study the transition from young to aging to AD. The network analysis revealed the organization of co-expression network into functional modules that are cell-type specific in aging and AD. We found that modules associated with astrocytes, endothelial cells and microglial cells are upregulated and significantly correlate with both aging and AD. The modules associated with neurons, mitochondria and endoplasmic reticulum are downregulated and significantly correlate with AD than aging. The oligodendrocytes module does not show significant correlation with neither aging nor disease. Further, we identified aging- and AD-specific interactions/subnetworks by integrating the gene expression with a human protein-protein interaction network. We found dysregulation of genes encoding protein kinases (FYN, SYK, SRC, PKC, MAPK1, ephrin receptors) and transcription factors (FOS, STAT3, CEBPB, MYC, NFKβ, and EGR1) in AD. Further, we found genes that encode proteins with neuroprotective function (14-3-3 proteins, PIN1, ATXN1, BDNF, VEGFA) to be part of the downregulated AD subnetwork. Our study highlights that simultaneously analyzing aging and AD will help to understand the pre-clinical and clinical phase of AD and aid in developing the treatment strategies.
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Affiliation(s)
- Vinay Lanke
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology, Hyderabad, Hyderabad, India
| | - S T R Moolamalla
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology, Hyderabad, Hyderabad, India
| | - Dipanjan Roy
- Cognitive Brain Dynamics Lab, National Brain Research Centre, Gurgaon, India
| | - P K Vinod
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology, Hyderabad, Hyderabad, India
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253
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Zhang D, Mably AJ, Walsh DM, Rowan MJ. Peripheral Interventions Enhancing Brain Glutamate Homeostasis Relieve Amyloid β- and TNFα- Mediated Synaptic Plasticity Disruption in the Rat Hippocampus. Cereb Cortex 2018; 27:3724-3735. [PMID: 27390019 DOI: 10.1093/cercor/bhw193] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Dysregulation of glutamate homeostasis in the interstitial fluid of the brain is strongly implicated in causing synaptic dysfunction in many neurological and psychiatric illnesses. In the case of Alzheimer's disease (AD), amyloid β (Aβ)-mediated disruption of synaptic plasticity and memory can be alleviated by interventions that directly remove glutamate or block certain glutamate receptors. An alternative strategy is to facilitate the removal of excess glutamate from the nervous system by activating peripheral glutamate clearance systems. One such blood-based system, glutamate oxaloacetate transaminase (GOT), is activated by oxaloacetate, which acts as a co-substrate. We report here that synthetic and AD brain-derived Aβ-mediated inhibition of synaptic long-term potentiation in the hippocampus is alleviated by oxaloacetate. Moreover the effect of oxaloacetate was GOT-dependent. The disruptive effects of a general inhibitor of excitatory amino acid transport or TNFα, a pro-inflammatory mediator of Aβ action, were also reversed by oxaloacetate. Furthermore, another intervention that increases peripheral glutamate clearance, peritoneal dialysis, mimicked the beneficial effect of oxaloacetate. These findings lend support to the promotion of the peripheral clearance of glutamate as a means to alleviate synaptic dysfunction that is caused by impaired glutamate homeostasis in the brain.
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Affiliation(s)
- Dainan Zhang
- Department of Pharmacology and Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Alexandra J Mably
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham & Women's Hospital, Harvard Institute of Medicine, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Dominic M Walsh
- Laboratory for Neurodegenerative Research, Ann Romney Center for Neurologic Diseases, Brigham & Women's Hospital, Harvard Institute of Medicine, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
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254
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Amyloid causes intermittent network disruptions in cognitively intact older subjects. Brain Imaging Behav 2018; 13:699-716. [DOI: 10.1007/s11682-018-9869-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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255
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Reactive Astrocytes as Drug Target in Alzheimer's Disease. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4160247. [PMID: 29888263 PMCID: PMC5977027 DOI: 10.1155/2018/4160247] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 03/20/2018] [Accepted: 04/10/2018] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease is a neurodegenerative disease characterized by deposition of extracellular amyloid-β, intracellular neurofibrillary tangles, and loss of cortical neurons. However, the mechanism underlying neurodegeneration in Alzheimer's disease (AD) remains to be explored. Many of the researches on AD have been primarily focused on neuronal changes. Current research, however, broadens to give emphasis on the importance of nonneuronal cells, such as astrocytes. Astrocytes play fundamental roles in several cerebral functions and their dysfunctions promote neurodegeneration and, eventually, retraction of neuronal synapses, which leads to cognitive deficits found in AD. Astrocytes become reactive as a result of deposition of Aβ, which in turn have detrimental consequences, including decreased glutamate uptake due to reduced expression of uptake transporters, altered energy metabolism, altered ion homeostasis (K+ and Ca+), increased tonic inhibition, and increased release of cytokines and inflammatory mediators. In this review, recent insights on the involvement of, tonic inhibition, astrocytic glutamate transporters and aquaporin in the pathogenesis of Alzheimer's disease are provided. Compounds which increase expression of GLT1 have showed efficacy for AD in preclinical studies. Tonic inhibition mediated by GABA could also be a promising target and drugs that block the GABA synthesizing enzyme, MAO-B, have shown efficacy. However, there are contradictory evidences on the role of AQP4 in AD.
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256
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Jin YY, Singh P, Chung HJ, Hong ST. Blood Ammonia as a Possible Etiological Agent for Alzheimer's Disease. Nutrients 2018; 10:E564. [PMID: 29734664 PMCID: PMC5986444 DOI: 10.3390/nu10050564] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 04/26/2018] [Accepted: 05/01/2018] [Indexed: 02/07/2023] Open
Abstract
Alzheimer’s disease (AD), characterized by cognitive decline and devastating neurodegeneration, is the most common age-related dementia. Since AD is a typical example of a complex disease that is affected by various genetic and environmental factors, various factors could be involved in preventing and/or treating AD. Extracellular accumulation of beta-amyloid peptide (Aβ) and intracellular accumulation of tau undeniably play essential roles in the etiology of AD. However, interestingly enough, medications targeting Aβ or tau all failed and the only clinically efficient medications for AD are drugs targeting the cholinergic pathway. Also, a very intriguing discovery in AD is that the Mediterranean diet (MeDi), containing an unusually large quantity of Lactobacilli, is very effective in preventing AD. Based on recently emerging findings, it is our opinion that the reduction of blood ammonia levels by Lactobacilli in MeDi is the therapeutic agent of MeDi for AD. The recent evidence of Lactobacilli lowering blood ammonia level not only provides a link between AD and MeDi but also provides a foundation of pharmabiotics for hyperammonemia as well as various neurological diseases.
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Affiliation(s)
- Yan Yan Jin
- Department of Biomedical Sciences and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Chonbuk 54907, Korea.
| | - Parul Singh
- Department of Biomedical Sciences and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Chonbuk 54907, Korea.
| | - Hea-Jong Chung
- Department of Biomedical Sciences and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Chonbuk 54907, Korea.
| | - Seong-Tschool Hong
- Department of Biomedical Sciences and Institute for Medical Science, Chonbuk National University Medical School, Jeonju, Chonbuk 54907, Korea.
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257
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Song Z, Yang W, Cheng G, Zhou X, Yang L, Zhao D. Prion protein is essential for the RE1 silencing transcription factor (REST)-dependent developmental switch in synaptic NMDA receptors. Cell Death Dis 2018; 9:541. [PMID: 29748616 PMCID: PMC5945644 DOI: 10.1038/s41419-018-0576-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 03/19/2018] [Indexed: 12/11/2022]
Abstract
It is important that the correct amounts of GluN2 subunits are maintained, as they determine NMDAR functional properties, which are crucial to neuronal communication, synaptogenesis and cognitive function. The transcriptional repressor RE1 silencing transcription factor (REST) is critical for the postnatal developmental switch in NMDARs. However, the mechanisms triggering REST and the link between NMDARs and REST are unclear. Here we show a new physiological essential role for cellular prion protein (PrPC) in REST-dependent homeostasis and the developmental switch of NMDARs. REST and REST-associated proteins were overactivated in the hippocampi of Prnp knockout mice (Prnp 0/0 ) compared with wild-type Prnp (Prnp +/+ ) mice. This coincided with the disruption of the normal developmental switch from GluN2B-to-GluN2A in vivo. PrPC co-located with REST under physiological environments and mediated the translocation of REST in conditioners of NMDARs in vitro in Prnp +/+ hippocampal neurons. Regardless of whether REST was knocked down or overexpressed, deletion of PrPC not only disrupted REST-mediated distribution of mitochondria, but also prevented REST-regulated expression of GluN2B and GluN2A in Prnp 0/0 . Importantly, these effects were rescued after overexpression of full-length PrPC through restoration of NMDAR2 subunits and their distributions in dendritic processes in Prnp 0/0 . Consistently, knockdown of PrPC in Prnp +/+ had a similar effect on Prnp 0/0 . Furthermore, PrPC colocalized with both GluN2B and GluN2A in Prnp +/+ . For the first time, we demonstrate that PrPC is essential for REST-regulated NMDARs. Confirming the regulation of NMDAR-modulating mechanisms could provide novel therapeutic targets against dysfunctions of glutamatergic transmission in the nervous system.
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Affiliation(s)
- Zhiqi Song
- The State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, 100193, Beijing, China
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences (CAMS) and Comparative Medicine Center, Peking Union Medical Collage (PUMC), Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, 100021, Beijing, China
| | - Wei Yang
- The State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, 100193, Beijing, China
- Hebei Institute of Animal Science and Veterinary Medicine, 071000, Baoding, China
| | - Guangyu Cheng
- The State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, 100193, Beijing, China
| | - Xiangmei Zhou
- The State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, 100193, Beijing, China
| | - Lifeng Yang
- The State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, 100193, Beijing, China
| | - Deming Zhao
- The State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, 100193, Beijing, China.
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258
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Maruyama T, Wada H, Abe Y, Niikura T. Alteration of global protein SUMOylation in neurons and astrocytes in response to Alzheimer's disease-associated insults. Biochem Biophys Res Commun 2018; 500:470-475. [PMID: 29660340 DOI: 10.1016/j.bbrc.2018.04.104] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 04/13/2018] [Indexed: 12/20/2022]
Abstract
SUMOylation, a post-translational modification of lysine residues by small ubiquitin-like modifier (SUMO) proteins, has been implicated in the pathogenesis of neurodegenerative disorders including Alzheimer's disease (AD), and in neuron- and astrocyte-specific physiological functions. Global SUMOylation is increased in the AD mouse brain in the pre-plaque-forming stage but returns to wild-type levels in the plaque-bearing stage. To clarify the reason for the transient change in SUMOylation, we analyzed the alteration of global SUMOylation induced by AD-associated cytotoxic stimuli in neurons and astrocytes individually. In neurons, amyloid β42 oligomers induced some but not significant increase in levels of SUMO1-modified proteins. Both hydrogen peroxide and glutamate significantly reduced SUMO1-modified protein levels. These changes were more prominent in neurons than in astrocytes. The opposite effect of Aβ and oxidative/excitotoxic stimuli on SUMO1 modification may cause the pathological stage-associated change in the level of SUMO-modified proteins in the AD mouse brain.
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Affiliation(s)
- Takuma Maruyama
- Department of Information and Communication Sciences, Faculty of Science and Technology, Sophia University, Japan
| | - Harmony Wada
- Department of Information and Communication Sciences, Faculty of Science and Technology, Sophia University, Japan
| | - Yoichiro Abe
- Department of Pharmacology, Keio University School of Medicine, Japan
| | - Takako Niikura
- Department of Information and Communication Sciences, Faculty of Science and Technology, Sophia University, Japan.
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259
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Tanqueiro SR, Ramalho RM, Rodrigues TM, Lopes LV, Sebastião AM, Diógenes MJ. Inhibition of NMDA Receptors Prevents the Loss of BDNF Function Induced by Amyloid β. Front Pharmacol 2018; 9:237. [PMID: 29695962 PMCID: PMC5904251 DOI: 10.3389/fphar.2018.00237] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 03/02/2018] [Indexed: 01/18/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) plays important functions in cell survival and differentiation, neuronal outgrowth and plasticity. In Alzheimer’s disease (AD), BDNF signaling is known to be impaired, partially because amyloid β (Aβ) induces truncation of BDNF main receptor, TrkB-full length (TrkB-FL). We have previously shown that such truncation is mediated by calpains, results in the formation of an intracellular domain (ICD) fragment and causes BDNF loss of function. Since calpains are Ca2+-dependent proteases, we hypothesized that excessive intracellular Ca2+ build-up could be due to dysfunctional N-methyl-d-aspartate receptors (NMDARs) activation. To experimentally address this hypothesis, we investigated whether TrkB-FL truncation by calpains and consequent BDNF loss of function could be prevented by NMDAR blockade. We herein demonstrate that a NMDAR antagonist, memantine, prevented excessive calpain activation and TrkB-FL truncation induced by Aβ25–35. When calpains were inhibited by calpastatin, BDNF was able to increase the dendritic spine density of neurons exposed to Aβ25135. Moreover, NMDAR inhibition by memantine also prevented Aβ-driven deleterious impact of BDNF loss of function on structural (spine density) and functional outcomes (synaptic potentiation). Collectively, these findings support NMDAR/Ca2+/calpains mechanistic involvement in Aβ-triggered BDNF signaling disruption.
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Affiliation(s)
- Sara R Tanqueiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Rita M Ramalho
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Tiago M Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Luísa V Lopes
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Maria J Diógenes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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260
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Lee SJC, Nam E, Lee HJ, Savelieff MG, Lim MH. Towards an understanding of amyloid-β oligomers: characterization, toxicity mechanisms, and inhibitors. Chem Soc Rev 2018; 46:310-323. [PMID: 27878186 DOI: 10.1039/c6cs00731g] [Citation(s) in RCA: 347] [Impact Index Per Article: 57.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Alzheimer's disease (AD) is characterized by an imbalance between production and clearance of amyloid-β (Aβ) species. Aβ peptides can transform structurally from monomers into β-stranded fibrils via multiple oligomeric states. Among the various Aβ species, structured oligomers are proposed to be more toxic than fibrils; however, the identification of Aβ oligomers has been challenging due to their heterogeneous and metastable nature. Multiple techniques have recently helped us gain a better understanding of oligomers' assembly details and structural properties. Moreover, some progress on elucidating the mechanisms of oligomer-triggered toxicity has been made. Based on the collection of current findings, there is growing consensus that control of toxic Aβ oligomers could be a valid approach to regulate Aβ-associated toxicity, which could advance development of new diagnostics and therapeutics for amyloid-related diseases. In this review, we summarize the recent understanding of Aβ oligomers' assembly, structural properties, and toxicity, along with inhibitors against Aβ aggregation, including oligomerization.
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Affiliation(s)
- Shin Jung C Lee
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
| | - Eunju Nam
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
| | - Hyuck Jin Lee
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Masha G Savelieff
- Department of Neurosurgery, University of Michigan, Ann Arbor 48109, MI, USA and SciGency Science Communications, Ann Arbor 48104, MI, USA
| | - Mi Hee Lim
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
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261
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Abstract
Excitatory glutamatergic neurotransmission via N-methyl-d-aspartate receptor (NMDAR) is critical for synaptic plasticity and survival of neurons. However, excessive NMDAR activity causes excitotoxicity and promotes cell death, underlying a potential mechanism of neurodegeneration occurred in Alzheimer's disease (AD). Studies indicate that the distinct outcomes of NMDAR-mediated responses are induced by regionalized receptor activities, followed by different downstream signaling pathways. The activation of synaptic NMDARs initiates plasticity and stimulates cell survival. In contrast, the activation of extrasynaptic NMDARs promotes cell death and thus contributes to the etiology of AD, which can be blocked by an AD drug, memantine, an NMDAR antagonist that selectively blocks the function of extrasynaptic NMDARs.
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Affiliation(s)
- Rui Wang
- Garrison Institute on Aging, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - P Hemachandra Reddy
- Garrison Institute on Aging, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,Cell Biology & Biochemistry Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,Neuroscience & Pharmacology Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,Neurology Department, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,Speech, Language and Hearing Sciences Departments, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,Garrison Institute on Aging, South West Campus, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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262
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Hu S, Hu H, Mak S, Cui G, Lee M, Shan L, Wang Y, Lin H, Zhang Z, Han Y. A Novel Tetramethylpyrazine Derivative Prophylactically Protects against Glutamate-Induced Excitotoxicity in Primary Neurons through the Blockage of N-Methyl-D-aspartate Receptor. Front Pharmacol 2018; 9:73. [PMID: 29483871 PMCID: PMC5816056 DOI: 10.3389/fphar.2018.00073] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 01/22/2018] [Indexed: 12/18/2022] Open
Abstract
The over-activation of NMDA receptor via the excessive glutamate is believed to one of the most causal factors associated with Alzheimer’s disease (AD), a progressive neurodegenerative brain disorder. Molecules that could protect against glutamate-induced neurotoxicity may hold therapeutic values for treating AD. Herein, the neuroprotective mechanisms of dimeric DT-010, a novel derivative of naturally occurring danshensu and tetramethylpyrazine, were investigated using primary rat cerebellar granule neurons (CGNs) and hippocampal neurons. It was found that DT-010 (3–30 μM) markedly prevented excitotoxicity of CGNs caused by glutamate, as evidenced by the promotion of neuronal viability as well as the reversal of abnormal morphological changes. While its parent molecules did not show any protective effects even when their concentration reached 50 μM. Additionally, DT-010 almost fully blocked intracellular accumulation of reactive oxygen species caused by glutamate and exogenous oxidative stimulus. Moreover, Western blot results demonstrated that DT-010 remarkably attenuated the inhibition of pro-survival PI3K/Akt/GSK3β pathway caused by glutamate. Ca2+ imaging with Fluo-4 fluorescence analysis further revealed that DT-010 greatly declined glutamate-induced increase in intracellular Ca2+. Most importantly, with the use of whole-cell patch clamp electrophysiology, DT-010 directly inhibited NMDA-activated whole-cell currents in primary hippocampal neurons. Molecular docking simulation analysis further revealed a possible binding mode that inhibited NMDA receptor at the ion channel, showing that DT-010 favorably binds to Asn602 of NMDA receptor via arene hydrogen bond. These results suggest that DT-010 could be served as a novel NMDA receptor antagonist and protect against glutamate-induced excitotoxicity from blocking the upstream NMDA receptors to the subsequent Ca2+ influx and to the downstream GSK3β cascade.
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Affiliation(s)
- Shengquan Hu
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China.,Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hong Kong, China
| | - Huihui Hu
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Shinghung Mak
- Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hong Kong, China.,Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, China
| | - Guozhen Cui
- Department of Bioengineering, Zunyi Medical University, Zhuhai, China
| | - Mingyuen Lee
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau
| | - Luchen Shan
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Yuqiang Wang
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Huangquan Lin
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Zaijun Zhang
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Yifan Han
- Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hong Kong, China.,Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, China
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263
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Guercio GD, Panizzutti R. Potential and Challenges for the Clinical Use of d-Serine As a Cognitive Enhancer. Front Psychiatry 2018; 9:14. [PMID: 29459833 PMCID: PMC5807334 DOI: 10.3389/fpsyt.2018.00014] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 01/17/2018] [Indexed: 12/16/2022] Open
Abstract
After 25 years of its discovery in the rat brain, d-serine is a recognized modulator of synaptic plasticity and cognitive processes through its actions on the NMDA-glutamate receptor. Importantly, cognitive impairment is a core feature of conditions, such as schizophrenia, Alzheimer's disease, depression, and aging, and is associated to disturbances in NMDA-glutamate receptors. The d-serine pathway has been associated with cognitive deficits and these conditions, and, for this reason, d-serine signaling is subject of intense research to probe its role in aiding diagnosis and therapy. Nevertheless, this has not resulted in new therapies being incorporated into clinical practice. Therefore, in this review we will address many questions that need to be solved by future studies, regarding d-serine pharmacokinetics, possible side effects, other strategies to modulate its levels, and combination with other therapies to increase its efficacy.
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Affiliation(s)
- Gerson D. Guercio
- Instituto de Ciencias Biomedicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rogerio Panizzutti
- Instituto de Ciencias Biomedicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Global Brain Health Institute, Trinity College Dublin, Dublin, Ireland
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264
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Lee WJ, Ham SA, Yoo H, Hwang JS, Yoo T, Paek KS, Lim DS, Han SG, Lee CH, Hong K, Seo HG. Activation of PPARδ attenuates neurotoxicity by inhibiting lipopolysaccharide-triggered glutamate release in BV-2 microglial cells. J Cell Biochem 2018; 119:5609-5619. [PMID: 29388693 DOI: 10.1002/jcb.26732] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 01/29/2018] [Indexed: 12/25/2022]
Abstract
Neuroinflammation-associated release of glutamate from activated microglia has been implicated in the progression of neurodegenerative diseases. However, the regulatory mechanisms underlying this glutamate release are poorly understood. Here, we show that peroxisome proliferator-activated receptor delta (PPARδ) modulates neurotoxicity by inhibiting glutamate release in lipopolysaccharide (LPS)-activated BV-2 microglial cells. Activation of PPARδ by GW501516, a specific PPARδ agonist, inhibited glutamate release in BV-2 cells. This effect of GW501516 was significantly blocked by shRNA-mediated knockdown of PPARδ and by treatment with GSK0660, a specific PPARδ antagonist, indicating that PPARδ is associated with blockade of glutamate release. Additionally, GW501516-activated PPARδ suppressed generation of reactive oxygen species and expression of gp91phox, a functional subunit of NADPH oxidase 2, in BV-2 cells stimulated with LPS. The inhibitory effect of GW501516 on gp91phox expression and glutamate release was further potentiated in the presence of AG490, a specific inhibitor of janus kinase 2 (JAK2), leading to the inhibition of signal transducer and activator of transcription 1 (STAT1). By contrast, GW501516 upregulated the expression of suppressor of cytokine signaling 1 (SOCS1), an endogenous inhibitor of JAK2. Furthermore, neurotoxicity induced by conditioned media from LPS-stimulated BV-2 cells was significantly reduced when conditioned media from BV-2 cells treated with both LPS and GW501516 were used. These results indicate that PPARδ attenuates LPS-triggered neuroinflammation by enhancing SOCS1-mediated inhibition of JAK2/STAT1 signaling, thereby inhibiting neurotoxicity associated with glutamate release.
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Affiliation(s)
- Won Jin Lee
- Sanghuh College of Life Sciences, Konkuk University, Gwangjin-gu, Seoul, Korea
| | - Sun Ah Ham
- Sanghuh College of Life Sciences, Konkuk University, Gwangjin-gu, Seoul, Korea
| | - Hyunjin Yoo
- Department of Stem Cell & Regenerative Biotechnology, Konkuk University, Gwangjin-gu, Seoul, Korea
| | - Jung Seok Hwang
- Sanghuh College of Life Sciences, Konkuk University, Gwangjin-gu, Seoul, Korea
| | - Taesik Yoo
- Sanghuh College of Life Sciences, Konkuk University, Gwangjin-gu, Seoul, Korea
| | | | - Dae-Seog Lim
- Department of Biotechnology, CHA University, Bundang-gu, Seongnam, Korea
| | - Sung Gu Han
- Sanghuh College of Life Sciences, Konkuk University, Gwangjin-gu, Seoul, Korea
| | - Chi-Ho Lee
- Sanghuh College of Life Sciences, Konkuk University, Gwangjin-gu, Seoul, Korea
| | - Kwonho Hong
- Department of Stem Cell & Regenerative Biotechnology, Konkuk University, Gwangjin-gu, Seoul, Korea
| | - Han Geuk Seo
- Sanghuh College of Life Sciences, Konkuk University, Gwangjin-gu, Seoul, Korea
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265
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Jurado S. AMPA Receptor Trafficking in Natural and Pathological Aging. Front Mol Neurosci 2018; 10:446. [PMID: 29375307 PMCID: PMC5767248 DOI: 10.3389/fnmol.2017.00446] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/21/2017] [Indexed: 01/09/2023] Open
Abstract
α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) enable most excitatory transmission in the brain and are crucial for mediating basal synaptic strength and plasticity. Because of the importance of their function, AMPAR dynamics, activity and subunit composition undergo a tight regulation which begins as early as prenatal development and continues through adulthood. Accumulating evidence suggests that the precise regulatory mechanisms involved in orchestrating AMPAR trafficking are challenged in the aging brain. In turn dysregulation of AMPARs can be linked to most neurological and neurodegenerative disorders. Understanding the mechanisms that govern AMPAR signaling during natural and pathological cognitive decline will guide the efforts to develop most effective ways to tackle neurodegenerative diseases which are one of the primary burdens afflicting an increasingly aging population. In this review, I provide a brief overview of the molecular mechanisms involved in AMPAR trafficking highlighting what is currently known about how these processes change with age and disease. As a particularly well-studied example of AMPAR dysfunction in pathological aging I focus in Alzheimer’s disease (AD) with special emphasis in how the production of neurofibrillary tangles (NFTs) and amyloid-β plaques may contribute to disruption in AMPAR function.
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Affiliation(s)
- Sandra Jurado
- Instituto de Neurociencias CSIC-UMH, San Juan de Alicante, Spain
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266
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Abstract
A recently identified mechanism for oligomeric Aβ-induced glutamate release from astrocytes involves intracellular Ca elevation, potentially by Ca-dependent vesicular release. Evidence suggests that levetiracetam (LEV; Keppra), an antiepileptic drug, can improve cognitive performance in both humans with mild cognitive impairment and animal models of Alzheimer disease. Because LEV acts by modulating neurotransmitter release from neurons by interaction with synaptic vesicles, we tested the effect of LEV on Aβ-induced astrocytic release of glutamate. We used a fluorescence resonance energy transfer-based glutamate sensor (termed SuperGluSnFR), whose structure is based on the ligand-binding site of glutamate receptors, to monitor glutamate release from primary cultures of human astrocytes exposed to oligomeric amyloid-β peptide 1-42 (Aβ42). We found that LEV (10 µM) inhibited oligomeric Aβ-induced astrocytic glutamate release. In addition, we show that this Aβ-induced glutamate release from astrocytes is sensitive to tetanus neurotoxin, an inhibitor of the vesicle release machinery. Taken together, our evidence suggests that LEV inhibits Aβ-induced vesicular glutamate release from astrocytes and thus may underlie, at least in part, the ability of LEV to reduce hyperexcitability in Alzheimer disease.
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267
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Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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268
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Xanthoceraside modulates NR2B-containing NMDA receptors at synapses and rescues learning-memory deficits in APP/PS1 transgenic mice. Psychopharmacology (Berl) 2018; 235:337-349. [PMID: 29124300 DOI: 10.1007/s00213-017-4775-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/23/2017] [Indexed: 01/22/2023]
Abstract
RATIONALE Alzheimer's disease (AD) is characterized by memory loss and synaptic damage. Previous studies suggested that xanthoceraside decreases glutamate-induced PC12 cell death, ameliorates memory deficits, and increases the number of dendritic spines in AD mice. These results indicated that xanthoceraside might have activities that protect synaptic plasticity. Herein, we detected the effect of xanthoceraside on synaptic function. MATERIALS AND METHODS Three-month-old APP/PS1 transgenic mice were orally treated with xanthoceraside (0.02, 0.08, or 0.32 mg/kg) once daily for 4 months and then behavioral tests were performed. LTP and Fluo-4/AM were carried out in vivo and in vitro, respectively. CaMKII-GluR1 and NR2B-associated proteins on synapses were measured. RESULTS Xanthoceraside administration alleviated learning-memory deficits and increased the LTP in APP/PS1 transgenic mice. Meanwhile, xanthoceraside increased the expression of pT286-CaMKII in synaptic and extrasynaptic pools and CaMKII, pS831-GluR1, and GluR1 in synaptic pools. In addition, xanthoceraside increased the total pY1472-NR2B and NR2B expression and increased the levels of pY1472-NR2B in synaptic and extrasynaptic pools and NR2B in synaptic pools. However, NR2B was decreased in extrasynaptic pools, which might be associated with decreased expression of STEP61 and pY531-Fyn. In vitro studies showed that xanthoceraside inhibited intracellular calcium overload and increased the number of and extended the length of dendrites in primary hippocampal neurons compared with the Aβ25-35 group. CONCLUSIONS The mechanism of xanthoceraside on ameliorating learning-memory deficits might be related to decrease intracellular calcium overload, increase CaMKII-GluR1 proteins, and up-regulate trafficking of pY1472-NR2B at synapse, thereby improving LTP in APP/PS1 transgenic mice.
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269
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Verkhratsky A, Nedergaard M. Physiology of Astroglia. Physiol Rev 2018; 98:239-389. [PMID: 29351512 PMCID: PMC6050349 DOI: 10.1152/physrev.00042.2016] [Citation(s) in RCA: 939] [Impact Index Per Article: 156.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/22/2017] [Accepted: 04/27/2017] [Indexed: 02/07/2023] Open
Abstract
Astrocytes are neural cells of ectodermal, neuroepithelial origin that provide for homeostasis and defense of the central nervous system (CNS). Astrocytes are highly heterogeneous in morphological appearance; they express a multitude of receptors, channels, and membrane transporters. This complement underlies their remarkable adaptive plasticity that defines the functional maintenance of the CNS in development and aging. Astrocytes are tightly integrated into neural networks and act within the context of neural tissue; astrocytes control homeostasis of the CNS at all levels of organization from molecular to the whole organ.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
| | - Maiken Nedergaard
- The University of Manchester , Manchester , United Kingdom ; Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science , Bilbao , Spain ; Department of Neuroscience, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain ; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark ; and Center for Translational Neuromedicine, University of Rochester Medical Center , Rochester, New York
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270
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Uncoupling DAPK1 from NMDA receptor GluN2B subunit exerts rapid antidepressant-like effects. Mol Psychiatry 2018; 23:597-608. [PMID: 28439098 PMCID: PMC5822462 DOI: 10.1038/mp.2017.85] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 02/23/2017] [Accepted: 02/28/2017] [Indexed: 02/08/2023]
Abstract
Several preclinical studies have reported the rapid antidepressant effects of N-methyl-D-aspartate receptor (NMDAR) antagonists, although the underlying mechanisms are still unclear. Death-associated protein kinase 1 (DAPK1) couples GluN2B subunits at extrasynaptic sites to regulate NMDAR channel conductance. In the present study, we found that chronic unpredictable stress (CUS) induced extracellular glutamate accumulation, accompanied by an increase in the DAPK1-NMDAR interaction, the high expression of DAPK1 and phosphorylated GluN2B at Ser1303, a decrease in phosphorylated DAPK1 at Ser308 and synaptic protein deficits in the rat medial prefrontal cortex (mPFC). CUS also enhanced GluN2B-mediated NMDA currents and extrasynaptic responses that were induced by bursts of high-frequency stimulation, which may be associated with the loss of astrocytes and low expression of glutamate transporter-1 (GLT-1). The blockade of GLT-1 in the mPFC was sufficient to induce depressive-like behavior and cause similar molecular changes. Selective GluN2B antagonist, DAPK1 knockdown by adeno-associated virus-mediated short-hairpin RNA or a pharmacological inhibitor, and the uncoupling of DAPK1 from the NMDAR GluN2B subunit produced rapid antidepressant-like effects and reversed CUS-induced alterations in the mPFC. The inhibition of DAPK1 and its interaction with GluN2B subunit in the mPFC also rescued CUS-induced depressive-like behavior 7 days after treatment. A selective GluN2B antagonist did not have rewarding effects in the conditioned place preference paradigm. Altogether, our findings suggest that the DAPK1 interaction with the NMDAR GluN2B subunit acts as a critical component in the pathophysiology of depression and is a potential target for new antidepressant treatments.
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271
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Melkonyan MM, Hunanyan L, Lourhmati A, Layer N, Beer-Hammer S, Yenkoyan K, Schwab M, Danielyan L. Neuroprotective, Neurogenic, and Amyloid Beta Reducing Effect of a Novel Alpha 2-Adrenoblocker, Mesedin, on Astroglia and Neuronal Progenitors upon Hypoxia and Glutamate Exposure. Int J Mol Sci 2017; 19:ijms19010009. [PMID: 29267189 PMCID: PMC5795961 DOI: 10.3390/ijms19010009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/17/2017] [Accepted: 12/19/2017] [Indexed: 12/17/2022] Open
Abstract
Locus coeruleus-noradrenergic system dysfunction is known to contribute to the progression of Alzheimer’s disease (AD). Besides a variety of reports showing the involvement of norepinephrine and its receptor systems in cognition, amyloid β (Aβ) metabolism, neuroinflammation, and neurogenesis, little is known about the contribution of the specific receptors to these actions. Here, we investigated the neurogenic and neuroprotective properties of a new α2 adrenoblocker, mesedin, in astroglial primary cultures (APC) from C57BL/6 and 3×Tg-AD mice. Our results demonstrate that mesedin rescues neuronal precursors and young neurons, and reduces the lactate dehydrogenase (LDH) release from astroglia under hypoxic and normoxic conditions. Mesedin also increased choline acetyltransferase, postsynaptic density marker 95 (PSD95), and Aβ-degrading enzyme neprilysin in the wild type APC, while in the 3×Tg-AD APC exposed to glutamate, it decreased the intracellular content of Aβ and enhanced the survival of synaptophysin-positive astroglia and neurons. These effects in APC can at least partially be attributed to the mesedin’s ability of increasing the expression of Interleukine(IL)-10, which is a potent anti-inflammatory, neuroprotective neurogenic, and Aβ metabolism enhancing factor. In summary, our data identify the neurogenic, neuroprotective, and anti-amyloidogenic action of mesedin in APC. Further in vivo studies are needed to estimate the therapeutic value of mesedin for AD.
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Affiliation(s)
- Magda M Melkonyan
- Department of Medical Chemistry, Yerevan state Medical University after M. Heratsi, 2 Koryun St., Yerevan 0025, Armenia.
| | - Lilit Hunanyan
- Department of Medical Chemistry, Yerevan state Medical University after M. Heratsi, 2 Koryun St., Yerevan 0025, Armenia.
| | - Ali Lourhmati
- Department of Clinical Pharmacology, Institute of Clinical and Experimental Pharmacology and Toxicology, University Hospital of Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany.
| | - Nikolas Layer
- Department of Clinical Pharmacology, Institute of Clinical and Experimental Pharmacology and Toxicology, University Hospital of Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany.
| | - Sandra Beer-Hammer
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology and ICePhA, University of Tuebingen, Wilhelmstr. 56, D-72076 Tübingen, Germany.
| | - Konstantin Yenkoyan
- Biochemistry Department, Yerevan state Medical University after M. Heratsi, 2 Koryun St., Yerevan 0025, Armenia.
| | - Matthias Schwab
- Department of Clinical Pharmacology, Institute of Clinical and Experimental Pharmacology and Toxicology, University Hospital of Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany.
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, University of Tübingen, Stuttgart, Auerbachstr. 112, D-70376 Stuttgart, Germany.
- Department of Pharmacy and Biochemistry, University of Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany.
| | - Lusine Danielyan
- Department of Clinical Pharmacology, Institute of Clinical and Experimental Pharmacology and Toxicology, University Hospital of Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany.
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272
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Mueller SG, Weiner MW. Amyloid Associated Intermittent Network Disruptions in Cognitively Intact Older Subjects: Structural Connectivity Matters. Front Aging Neurosci 2017; 9:418. [PMID: 29311904 PMCID: PMC5742224 DOI: 10.3389/fnagi.2017.00418] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 12/06/2017] [Indexed: 01/20/2023] Open
Abstract
Observations in animal models suggest that amyloid can cause network hypersynchrony in the early preclinical phase of Alzheimer's disease (AD). The aim of this study was (a) to obtain evidence of paroxysmal hypersynchrony in cognitively intact subjects (CN) with increased brain amyloid load from task-free fMRI exams using a dynamic analysis approach, (b) to investigate if and how hypersynchrony interferes with memory performance, and (c) to describe its relationship with gray and white matter connectivity. Florbetapir-F18 PET and task-free 3T functional and structural MRI were acquired in 47 CN (age = 70.6 ± 6.6), 17 were amyloid pos (florbetapir SUVR >1.11). A parcellation scheme encompassing 382 regions of interest was used to extract regional gray matter volumes, FA-weighted fiber tracts and regional BOLD signals. Graph analysis was used to characterize the gray matter atrophy profile and the white matter connectivity of each subject. The fMRI data was processed using a combination of sliding windows, graph and hierarchical cluster analysis. Each activity cluster was characterized by identifying strength dispersion (difference between pos and neg strength) their maximal and minimal pos and neg strength rois and by investigating their distribution and association with memory performance and gray and white matter connectivity using spearman rank correlations (FDR p < 0.05). The cluster analysis identified eight different activity clusters. Cluster 8 was characterized by the largest strength dispersion indicating hypersynchrony. Its duration/subject was positively correlated with amyloid load (r = 0.42, p = 0.03) and negatively with memory performance (CVLT delayed recall r = -0.39 p = 0.04). The assessment of the regional strength distribution indicated a functional disconnection between mesial temporal structures and the rest of the brain. White matter connectivity was increased in left lateral and mesial temporal lobe and was positively correlated with strength dispersion in the cross-modality analysis suggesting that it enables widespread hypersynchrony. In contrast, precuneus, gray matter connectivity was decreased in the right fusiform gyrus and negatively correlated with high degrees of strength dispersion suggesting that progressing gray matter atrophy could prevent the generation of paroxysmal hypersynchrony in later stages of the disease.
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Affiliation(s)
- Susanne G Mueller
- Center for Imaging of Neurodegenerative Diseases, San Francisco Veterans Affairs Medical Center, San Francisco, CA, United States.,Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
| | - Michael W Weiner
- Center for Imaging of Neurodegenerative Diseases, San Francisco Veterans Affairs Medical Center, San Francisco, CA, United States.,Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States
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273
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González-Reyes RE, Nava-Mesa MO, Vargas-Sánchez K, Ariza-Salamanca D, Mora-Muñoz L. Involvement of Astrocytes in Alzheimer's Disease from a Neuroinflammatory and Oxidative Stress Perspective. Front Mol Neurosci 2017; 10:427. [PMID: 29311817 PMCID: PMC5742194 DOI: 10.3389/fnmol.2017.00427] [Citation(s) in RCA: 329] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 12/06/2017] [Indexed: 12/19/2022] Open
Abstract
Alzheimer disease (AD) is a frequent and devastating neurodegenerative disease in humans, but still no curative treatment has been developed. Although many explicative theories have been proposed, precise pathophysiological mechanisms are unknown. Due to the importance of astrocytes in brain homeostasis they have become interesting targets for the study of AD. Changes in astrocyte function have been observed in brains from individuals with AD, as well as in AD in vitro and in vivo animal models. The presence of amyloid beta (Aβ) has been shown to disrupt gliotransmission, neurotransmitter uptake, and alter calcium signaling in astrocytes. Furthermore, astrocytes express apolipoprotein E and are involved in the production, degradation and removal of Aβ. As well, changes in astrocytes that precede other pathological characteristics observed in AD, point to an early contribution of astroglia in this disease. Astrocytes participate in the inflammatory/immune responses of the central nervous system. The presence of Aβ activates different cell receptors and intracellular signaling pathways, mainly the advanced glycation end products receptor/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway, responsible for the transcription of pro-inflammatory cytokines and chemokines in astrocytes. The release of these pro-inflammatory agents may induce cellular damage or even stimulate the production of Aβ in astrocytes. Additionally, Aβ induces the appearance of oxidative stress (OS) and production of reactive oxygen species and reactive nitrogen species in astrocytes, affecting among others, intracellular calcium levels, NADPH oxidase (NOX), NF-κB signaling, glutamate uptake (increasing the risk of excitotoxicity) and mitochondrial function. Excessive neuroinflammation and OS are observed in AD, and astrocytes seem to be involved in both. The Aβ/NF-κB interaction in astrocytes may play a central role in these inflammatory and OS changes present in AD. In this paper, we also discuss therapeutic measures highlighting the importance of astrocytes in AD pathology. Several new therapeutic approaches involving phenols (curcumin), phytoestrogens (genistein), neuroesteroids and other natural phytochemicals have been explored in astrocytes, obtaining some promising results regarding cognitive improvements and attenuation of neuroinflammation. Novel strategies comprising astrocytes and aimed to reduce OS in AD have also been proposed. These include estrogen receptor agonists (pelargonidin), Bambusae concretio Salicea, Monascin, and various antioxidatives such as resveratrol, tocotrienol, anthocyanins, and epicatechin, showing beneficial effects in AD models.
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Affiliation(s)
- Rodrigo E González-Reyes
- Grupo de Investigación en Neurociencias (NeURos), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia
| | - Mauricio O Nava-Mesa
- Grupo de Investigación en Neurociencias (NeURos), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia
| | - Karina Vargas-Sánchez
- Biomedical Sciences Research Group, School of Medicine, Universidad Antonio Nariño, Bogotá, Colombia
| | - Daniel Ariza-Salamanca
- Grupo de Investigación en Neurociencias (NeURos), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia
| | - Laura Mora-Muñoz
- Grupo de Investigación en Neurociencias (NeURos), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia
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274
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Chun H, Lee CJ. Reactive astrocytes in Alzheimer's disease: A double-edged sword. Neurosci Res 2017; 126:44-52. [PMID: 29225140 DOI: 10.1016/j.neures.2017.11.012] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/07/2017] [Accepted: 11/07/2017] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) is a chronic and fatal disease, in which neuronal damage at its late stage cannot be easily reversed. Because AD progression is caused by multiple factors including diverse cellular processes, studies on AD pathogenesis at the molecular and cellular level are challenging. Based on the lessons from unsuccessful neuron-focused research for an AD cure, non-cell autonomous mechanisms including brain inflammation and reactive astrocytes have recently been in the spotlight as potential therapeutic targets for AD. Studies have shown that reactive astrocytes are not only the result of inflammatory defense reactions, but also an active catabolic decomposer that acts by taking up amyloid beta toxins. Here, we give an overview of the characteristics of reactive astrocytes as pathological features of AD. Reactive astrocytes exert biphasic effects, that is, beneficial or detrimental depending on multiple factors. Many efforts have been put forth for defining and characterizing molecular signatures for the beneficial and detrimental reactive astrocytes. In the foreseeable future, manipulating and targeting each established molecular signature should have profound therapeutic implications for the treatment of AD.
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Affiliation(s)
- Heejung Chun
- Center for Neuro-Medicine, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - C Justin Lee
- Center for Neuroscience and Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea; Bio-Med, University of Science and Technology (UST), Daejeon, 34132, Republic of Korea; Center for Glia-Neuron Interaction, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
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275
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Ochalek A, Mihalik B, Avci HX, Chandrasekaran A, Téglási A, Bock I, Giudice ML, Táncos Z, Molnár K, László L, Nielsen JE, Holst B, Freude K, Hyttel P, Kobolák J, Dinnyés A. Neurons derived from sporadic Alzheimer's disease iPSCs reveal elevated TAU hyperphosphorylation, increased amyloid levels, and GSK3B activation. ALZHEIMERS RESEARCH & THERAPY 2017; 9:90. [PMID: 29191219 PMCID: PMC5709977 DOI: 10.1186/s13195-017-0317-z] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/27/2017] [Indexed: 12/16/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common type of dementia, affecting one in eight adults over 65 years of age. The majority of AD cases are sporadic, with unknown etiology, and only 5% of all patients with AD present the familial monogenic form of the disease. In the present study, our aim was to establish an in vitro cell model based on patient-specific human neurons to study the pathomechanism of sporadic AD. METHODS We compared neurons derived from induced pluripotent stem cell (iPSC) lines of patients with early-onset familial Alzheimer's disease (fAD), all caused by mutations in the PSEN1 gene; patients with late-onset sporadic Alzheimer's disease (sAD); and three control individuals without dementia. The iPSC lines were differentiated toward mature cortical neurons, and AD pathological hallmarks were analyzed by RT-qPCR, enzyme-linked immunosorbent assay, and Western blotting methods. RESULTS Neurons from patients with fAD and patients with sAD showed increased phosphorylation of TAU protein at all investigated phosphorylation sites. Relative to the control neurons, neurons derived from patients with fAD and patients with sAD exhibited higher levels of extracellular amyloid-β 1-40 (Aβ1-40) and amyloid-β 1-42 (Aβ1-42). However, significantly increased Aβ1-42/Aβ1-40 ratios, which is one of the pathological markers of fAD, were observed only in samples of patients with fAD. Additionally, we detected increased levels of active glycogen synthase kinase 3 β, a physiological kinase of TAU, in neurons derived from AD iPSCs, as well as significant upregulation of amyloid precursor protein (APP) synthesis and APP carboxy-terminal fragment cleavage. Moreover, elevated sensitivity to oxidative stress, as induced by amyloid oligomers or peroxide, was detected in both fAD- and sAD-derived neurons. CONCLUSIONS On the basis of the experiments we performed, we can conclude there is no evident difference except secreted Aβ1-40 levels in phenotype between fAD and sAD samples. To our knowledge, this is the first study in which the hyperphosphorylation of TAU protein has been compared in fAD and sAD iPSC-derived neurons. Our findings demonstrate that iPSC technology is suitable to model both fAD and sAD and may provide a platform for developing new treatment strategies for these conditions.
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Affiliation(s)
- Anna Ochalek
- Molecular Animal Biotechnology Laboratory, Szent István University, H-2100, Gödöllő, Hungary.,BioTalentum Ltd., Aulich Lajos Street 26, H-2100, Gödöllő, Hungary
| | - Balázs Mihalik
- BioTalentum Ltd., Aulich Lajos Street 26, H-2100, Gödöllő, Hungary
| | - Hasan X Avci
- BioTalentum Ltd., Aulich Lajos Street 26, H-2100, Gödöllő, Hungary.,Department of Anatomy, Embryology and Histology, Faculty of Medicine, University of Szeged, H-6700, Szeged, Hungary.,Present address: University Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, 72076, Tübingen, Germany
| | | | | | - István Bock
- BioTalentum Ltd., Aulich Lajos Street 26, H-2100, Gödöllő, Hungary
| | - Maria Lo Giudice
- BioTalentum Ltd., Aulich Lajos Street 26, H-2100, Gödöllő, Hungary
| | - Zsuzsanna Táncos
- BioTalentum Ltd., Aulich Lajos Street 26, H-2100, Gödöllő, Hungary
| | - Kinga Molnár
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117, Budapest, Hungary
| | - Lajos László
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117, Budapest, Hungary
| | - Jørgen E Nielsen
- Neurogenetics Clinic & Research Laboratory, Danish Dementia Research Centre, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | | | - Kristine Freude
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870, Copenhagen, Denmark
| | - Poul Hyttel
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870, Copenhagen, Denmark
| | - Julianna Kobolák
- BioTalentum Ltd., Aulich Lajos Street 26, H-2100, Gödöllő, Hungary
| | - András Dinnyés
- Molecular Animal Biotechnology Laboratory, Szent István University, H-2100, Gödöllő, Hungary. .,BioTalentum Ltd., Aulich Lajos Street 26, H-2100, Gödöllő, Hungary.
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276
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Musardo S, Marcello E. Synaptic dysfunction in Alzheimer's disease: From the role of amyloid β-peptide to the α-secretase ADAM10. Eur J Pharmacol 2017. [DOI: 10.1016/j.ejphar.2017.06.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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277
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Caraci F, Iulita MF, Pentz R, Flores Aguilar L, Orciani C, Barone C, Romano C, Drago F, Cuello AC. Searching for new pharmacological targets for the treatment of Alzheimer's disease in Down syndrome. Eur J Pharmacol 2017; 817:7-19. [DOI: 10.1016/j.ejphar.2017.10.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/26/2017] [Accepted: 10/04/2017] [Indexed: 11/26/2022]
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278
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Tu S, Akhtar MW, Escorihuela RM, Amador-Arjona A, Swarup V, Parker J, Zaremba JD, Holland T, Bansal N, Holohan DR, Lopez K, Ryan SD, Chan SF, Yan L, Zhang X, Huang X, Sultan A, McKercher SR, Ambasudhan R, Xu H, Wang Y, Geschwind DH, Roberts AJ, Terskikh AV, Rissman RA, Masliah E, Lipton SA, Nakanishi N. NitroSynapsin therapy for a mouse MEF2C haploinsufficiency model of human autism. Nat Commun 2017; 8:1488. [PMID: 29133852 PMCID: PMC5684358 DOI: 10.1038/s41467-017-01563-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 09/27/2017] [Indexed: 01/07/2023] Open
Abstract
Transcription factor MEF2C regulates multiple genes linked to autism spectrum disorder (ASD), and human MEF2C haploinsufficiency results in ASD, intellectual disability, and epilepsy. However, molecular mechanisms underlying MEF2C haploinsufficiency syndrome remain poorly understood. Here we report that Mef2c +/-(Mef2c-het) mice exhibit behavioral deficits resembling those of human patients. Gene expression analyses on brains from these mice show changes in genes associated with neurogenesis, synapse formation, and neuronal cell death. Accordingly, Mef2c-het mice exhibit decreased neurogenesis, enhanced neuronal apoptosis, and an increased ratio of excitatory to inhibitory (E/I) neurotransmission. Importantly, neurobehavioral deficits, E/I imbalance, and histological damage are all ameliorated by treatment with NitroSynapsin, a new dual-action compound related to the FDA-approved drug memantine, representing an uncompetitive/fast off-rate antagonist of NMDA-type glutamate receptors. These results suggest that MEF2C haploinsufficiency leads to abnormal brain development, E/I imbalance, and neurobehavioral dysfunction, which may be mitigated by pharmacological intervention.
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Affiliation(s)
- Shichun Tu
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA.
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
| | - Mohd Waseem Akhtar
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Rosa Maria Escorihuela
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
- Departament de PsiquiatriaiMedicina Legal, Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Alejandro Amador-Arjona
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Vivek Swarup
- Center for Autism Research and Treatment (CART), University of California, Los Angeles, CA, 90095, USA
| | - James Parker
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Jeffrey D Zaremba
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Timothy Holland
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Neha Bansal
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Daniel R Holohan
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Kevin Lopez
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Scott D Ryan
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Shing Fai Chan
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Li Yan
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Xiaofei Zhang
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Xiayu Huang
- Bioinformatics Core Facility, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Abdullah Sultan
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Scott R McKercher
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
- Department of Molecular Medicine and Neuroscience, Neuroscience Translational Center, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Rajesh Ambasudhan
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Huaxi Xu
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Yuqiang Wang
- Institute of New Drug Research, Jinan University College of Pharmacy, Guangzhou, 510632, China
| | - Daniel H Geschwind
- Center for Autism Research and Treatment (CART), University of California, Los Angeles, CA, 90095, USA
| | - Amanda J Roberts
- Department of Neuroscience and Mouse Behavioral Assessment Core, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Alexey V Terskikh
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Robert A Rissman
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, 92093, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA, 92161, USA
| | - Eliezer Masliah
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, 92093, USA
- National Institute on Aging, NIH, Bethesda, MD, 20892, USA
| | - Stuart A Lipton
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA.
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
- Department of Molecular Medicine and Neuroscience, Neuroscience Translational Center, The Scripps Research Institute, La Jolla, CA, 92037, USA.
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, 92093, USA.
| | - Nobuki Nakanishi
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA.
- Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
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279
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Mann AP, Scodeller P, Hussain S, Braun GB, Mölder T, Toome K, Ambasudhan R, Teesalu T, Lipton SA, Ruoslahti E. Identification of a peptide recognizing cerebrovascular changes in mouse models of Alzheimer's disease. Nat Commun 2017; 8:1403. [PMID: 29123083 PMCID: PMC5680235 DOI: 10.1038/s41467-017-01096-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 08/17/2017] [Indexed: 01/02/2023] Open
Abstract
Cerebrovascular changes occur in Alzheimer’s disease (AD). Using in vivo phage display, we searched for molecular markers of the neurovascular unit, including endothelial cells and astrocytes, in mouse models of AD. We identified a cyclic peptide, CDAGRKQKC (DAG), that accumulates in the hippocampus of hAPP-J20 mice at different ages. Intravenously injected DAG peptide homes to neurovascular unit endothelial cells and to reactive astrocytes in mouse models of AD. We identified connective tissue growth factor (CTGF), a matricellular protein that is highly expressed in the brain of individuals with AD and in mouse models, as the target of the DAG peptide. We also showed that exogenously delivered DAG homes to the brain in mouse models of glioblastoma, traumatic brain injury, and Parkinson’s disease. DAG may potentially be used as a tool to enhance delivery of therapeutics and imaging agents to sites of vascular changes and astrogliosis in diseases associated with neuroinflammation. Cerebrovascular changes and astrogliosis occur in Alzheimer’s disease (AD). Using an in vivo phage display technique, the authors identified a peptide that upon systematic administration, can home to brain endothelial cells and astrocytes in mouse models of AD at the early stages of the disease.
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Affiliation(s)
- Aman P Mann
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Pablo Scodeller
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.,Laboratory of Cancer Biology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, 50411, Estonia
| | - Sazid Hussain
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.,AivoCode Inc., La Jolla, CA, 92037, USA
| | - Gary B Braun
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Tarmo Mölder
- Laboratory of Cancer Biology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, 50411, Estonia
| | - Kadri Toome
- Laboratory of Cancer Biology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, 50411, Estonia
| | - Rajesh Ambasudhan
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA
| | - Tambet Teesalu
- Laboratory of Cancer Biology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, 50411, Estonia
| | - Stuart A Lipton
- Neurodegenerative Disease Center, Scintillon Institute, San Diego, CA, 92121, USA.,Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Erkki Ruoslahti
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA. .,Center for Nanomedicine and Department of Cell, Molecular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
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280
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Huang S, Tong H, Lei M, Zhou M, Guo W, Li G, Tang X, Li Z, Mo M, Zhang X, Chen X, Cen L, Wei L, Xiao Y, Li K, Huang Q, Yang X, Liu W, Zhang L, Qu S, Li S, Xu P. Astrocytic glutamatergic transporters are involved in Aβ-induced synaptic dysfunction. Brain Res 2017; 1678:129-137. [PMID: 29066369 DOI: 10.1016/j.brainres.2017.10.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 10/10/2017] [Accepted: 10/11/2017] [Indexed: 01/15/2023]
Abstract
In Alzheimer's disease (AD), dementia severity correlates most strongly with decreased synapse density in the hippocampus and cerebral cortex. Although studies in rodents have established that hippocampal long-term potentiation (LTP) is inhibited by soluble oligomers of beta-amyloid (Aβ), the synaptic mechanisms remain unclear. Here, field excitatory postsynaptic potentials (fEPSP) recordings were made in the CA1 region of mouse hippocampal slices. The medium of APP-expressing CHO cells, which contain soluble forms of Aβ including small oligomers, inhibited LTP and facilitated long-term depression (LTD), thus making the LTP/LTD curve shift toward the right. This phenomenon could be mimicked by the non-selective glutamate transporter inhibitor, DL-TBOA. More specifically, the Aβ impaired LTP and facilitated LTD were occluded by the selective astrocytic glutamate transporter inhibitors, TFB-TBOA. In cultured astrocytes, the Aβ oligomers also decrease astrocytic glutamate transporters (EAAT1, EAAT2) expression. We conclude that soluble Aβ oligomers decrease the activation of astrocytic glutamate transporters, thereby impairing synaptic plasticity.
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Affiliation(s)
- Shuxuan Huang
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Huichun Tong
- Clinical Medicine Research Centre, Shunde Hospital, Southern Medical University, Foshan, Guangdong 528300, China; Department of Neurology, Shunde Hospital, Southern Medical University, Foshan, Guangdong 528300, China
| | - Ming Lei
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China; Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Miaomiao Zhou
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Wenyuan Guo
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Guihua Li
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Xiaolu Tang
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Zhe Li
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Mingshu Mo
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Xiuping Zhang
- Teaching Center of Experimental Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Xiang Chen
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Luan Cen
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Lei Wei
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510082, China
| | - Yousheng Xiao
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Kaiping Li
- State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Qinghui Huang
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China; State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China
| | - Xinling Yang
- Department of Neurology, The Third Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830011, China
| | - Weiguo Liu
- Department of Geroatric&Neurology, Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Li Zhang
- Department of Geroatric&Neurology, Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Shaogang Qu
- Clinical Medicine Research Centre, Shunde Hospital, Southern Medical University, Foshan, Guangdong 528300, China; Department of Neurology, Shunde Hospital, Southern Medical University, Foshan, Guangdong 528300, China.
| | - Shaomin Li
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China; Ann Romney Center for Neurologic Disease, Brigham and Women's Hospital of Harvard Medical School, Boston, MA 02115, USA.
| | - Pingyi Xu
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120, China.
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281
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Altinoz MA, Elmaci İ. Targeting nitric oxide and NMDA receptor-associated pathways in treatment of high grade glial tumors. Hypotheses for nitro-memantine and nitrones. Nitric Oxide 2017; 79:68-83. [PMID: 29030124 DOI: 10.1016/j.niox.2017.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/26/2017] [Accepted: 10/07/2017] [Indexed: 12/31/2022]
Abstract
Glioblastoma multiforme (GBM) is a devastating brain cancer with no curative treatment. Targeting Nitric Oxide (NO) and glutamatergic pathways may help as adjunctive treatments in GBM. NO at low doses promotes tumorigenesis, while at higher levels (above 300 nM) triggers apoptosis. Gliomas actively secrete high amounts of glutamate which activates EGR signaling and mediates degradation of peritumoral tissues via excitotoxic injury. Memantine inhibits NMDA-subtype of glutamate receptors (NMDARs) and induces autophagic death of glioma cells in vitro and blocks glioma growth in vivo. Nitro-memantines may exert further benefits by limiting NMDAR signaling and by delivery of NO to the areas of excessive NMDAR activity leading NO-accumulation at tumoricidal levels within gliomas. Due to the duality of NO in tumorigenesis, agents which attenuate NO levels may also act beneficial in treatment of GBM. Nitrone compounds including N-tert-Butyl-α-phenylnitrone (PBN) and its disulfonyl-phenyl derivative, OKN-007 suppress free radical formation in experimental cerebral ischemia. OKN-007 failed to show clinical efficacy in stroke, but trials demonstrated its high biosafety in humans including elderly subjects. PBN inhibits the signaling pathways of NF-κB, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX). In animal models of liver cancer and glioblastoma, OKN-007 seemed more efficient than PBN in suppression of cell proliferation, microvascular density and in induction of apoptosis. OKN-007 also inhibits SULF2 enzyme, which promotes tumor growth via versatile pathways. We assume that nitromemantines may be more beneficial concomitant with chemo-radiotherapy while nitrones alone may act useful in suppressing basal tumor growth and angiogenesis.
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Affiliation(s)
- Meric A Altinoz
- Neuroacademy Group, Department of Neurosurgery, Memorial Hospital, Istanbul, Turkey.
| | - İlhan Elmaci
- Neuroacademy Group, Department of Neurosurgery, Memorial Hospital, Istanbul, Turkey
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282
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Jeong S. Molecular and Cellular Basis of Neurodegeneration in Alzheimer's Disease. Mol Cells 2017; 40:613-620. [PMID: 28927263 PMCID: PMC5638769 DOI: 10.14348/molcells.2017.0096] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/06/2017] [Accepted: 08/16/2017] [Indexed: 12/25/2022] Open
Abstract
The most common form of senile dementia is Alzheimer's disease (AD), which is characterized by the extracellular deposition of amyloid β-peptide (Aβ) plaques and the intracellular formation of neurofibrillary tangles (NFTs) in the cerebral cortex. Tau abnormalities are commonly observed in many neurodegenerative diseases including AD, Parkinson's disease, and Pick's disease. Interestingly, tau-mediated formation of NFTs in AD brains shows better correlation with cognitive impairment than Aβ plaque accumulation; pathological tau alone is sufficient to elicit frontotemporal dementia, but it does not cause AD. A growing amount of evidence suggests that soluble Aβ oligomers in concert with hyperphosphorylated tau (pTau) serve as the major pathogenic drivers of neurodegeneration in AD. Increased Aβ oligomers trigger neuronal dysfunction and network alternations in learning and memory circuitry prior to clinical onset of AD, leading to cognitive decline. Furthermore, accumulated damage to mitochondria in the course of aging, which is the best-known nongenetic risk factor for AD, may collaborate with soluble Aβ and pTau to induce synapse loss and cognitive impairment in AD. In this review, I summarize and discuss the current knowledge of the molecular and cellular biology of AD and also the mechanisms that underlie Aβ-mediated neurodegeneration.
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Affiliation(s)
- Sangyun Jeong
- Department of Molecular Biology, Chonbuk National University, Jeonju 54896,
Korea
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283
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Drugs to Alter Extracellular Concentration of Glutamate: Modulators of Glutamate Uptake Systems. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/978-1-4939-7228-9_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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284
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Astrocyte-Mediated Neuronal Synchronization Properties Revealed by False Gliotransmitter Release. J Neurosci 2017; 37:9859-9870. [PMID: 28899919 PMCID: PMC5637115 DOI: 10.1523/jneurosci.2761-16.2017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 06/14/2017] [Accepted: 06/27/2017] [Indexed: 12/21/2022] Open
Abstract
Astrocytes spontaneously release glutamate (Glut) as a gliotransmitter (GT), resulting in the generation of extrasynaptic NMDAR-mediated slow inward currents (SICs) in neighboring neurons, which can increase local neuronal excitability. However, there is a deficit in our knowledge of the factors that control spontaneous astrocyte GT release and the extent of its influence. We found that, in rat brain slices, increasing the supply of the physiological transmitter Glut increased the frequency and signaling charge of SICs over an extended period. This phenomenon was replicated by exogenous preexposure to the amino acid D-aspartate (D-Asp). Using D-Asp as a “false” GT, we determined the extent of local neuron excitation by GT release in ventrobasal thalamus, CA1 hippocampus, and somatosensory cortex. By analyzing synchronized neuronal NMDAR-mediated excitation, we found that the properties of the excitation were conserved in different brain areas. In the three areas, astrocyte-derived GT release synchronized groups of neurons at distances of >;200 μm. Individual neurons participated in more than one synchronized population, indicating that individual neurons can be excited by more than one astrocyte and that individual astrocytes may determine a neuron's synchronized network. The results confirm that astrocytes can act as excitatory nodes that can influence neurons over a significant range in a number of brain regions. Our findings further suggest that chronic elevation of ambient Glut levels can lead to increased GT Glut release, which may be relevant in some pathological states. SIGNIFICANCE STATEMENT Astrocytes spontaneously release glutamate (Glut) and other gliotransmitters (GTs) that can modify neuronal activity. Exposing brain slices to Glut and D-aspartate (D-Asp) before recording resulted in an increase in frequency of GT-mediated astrocyte–neuron signaling. Using D-Asp, it was possible to investigate the effects of specific GT release at neuronal NMDARs. Calcium imaging showed synchronized activity in groups of neurons in cortex, hippocampus, and thalamus. The size of these populations was similar in all areas and some neurons were involved in more than one synchronous group. The findings show that GT release is supply dependent and that the properties of the signaling and activated networks are largely conserved between different brain areas.
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285
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Ferrer I. Diversity of astroglial responses across human neurodegenerative disorders and brain aging. Brain Pathol 2017; 27:645-674. [PMID: 28804999 PMCID: PMC8029391 DOI: 10.1111/bpa.12538] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/24/2017] [Indexed: 12/11/2022] Open
Abstract
Astrogliopathy refers to alterations of astrocytes occurring in diseases of the nervous system, and it implies the involvement of astrocytes as key elements in the pathogenesis and pathology of diseases and injuries of the central nervous system. Reactive astrocytosis refers to the response of astrocytes to different insults to the nervous system, whereas astrocytopathy indicates hypertrophy, atrophy/degeneration and loss of function and pathological remodeling occurring as a primary cause of a disease or as a factor contributing to the development and progression of a particular disease. Reactive astrocytosis secondary to neuron loss and astrocytopathy due to intrinsic alterations of astrocytes occur in neurodegenerative diseases, overlap each other, and, together with astrocyte senescence, contribute to disease-specific astrogliopathy in aging and neurodegenerative diseases with abnormal protein aggregates in old age. In addition to the well-known increase in glial fibrillary acidic protein and other proteins in reactive astrocytes, astrocytopathy is evidenced by deposition of abnormal proteins such as β-amyloid, hyper-phosphorylated tau, abnormal α-synuclein, mutated huntingtin, phosphorylated TDP-43 and mutated SOD1, and PrPres , in Alzheimer's disease, tauopathies, Lewy body diseases, Huntington's disease, amyotrophic lateral sclerosis and Creutzfeldt-Jakob disease, respectively. Astrocytopathy in these diseases can also be manifested by impaired glutamate transport; abnormal metabolism and release of neurotransmitters; altered potassium, calcium and water channels resulting in abnormal ion and water homeostasis; abnormal glucose metabolism; abnormal lipid and, particularly, cholesterol metabolism; increased oxidative damage and altered oxidative stress responses; increased production of cytokines and mediators of the inflammatory response; altered expression of connexins with deterioration of cell-to-cell networks and transfer of gliotransmitters; and worsening function of the blood brain barrier, among others. Increased knowledge of these aspects will permit a better understanding of brain aging and neurodegenerative diseases in old age as complex disorders in which neurons are not the only players.
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Affiliation(s)
- Isidro Ferrer
- Department of Pathology and Experimental TherapeuticsUniversity of BarcelonaBarcelonaSpain
- Institute of NeuropathologyPathologic Anatomy Service, Bellvitge University Hospital, IDIBELL, Hospitalet de LlobregatBarcelonaSpain
- Institute of NeurosciencesUniversity of BarcelonaBarcelonaSpain
- Biomedical Network Research Center on Neurodegenerative Diseases (CIBERNED), Institute Carlos IIIMadridSpain
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286
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Liang J, Kulasiri D, Samarasinghe S. Computational investigation of Amyloid-β-induced location- and subunit-specific disturbances of NMDAR at hippocampal dendritic spine in Alzheimer's disease. PLoS One 2017; 12:e0182743. [PMID: 28837653 PMCID: PMC5570373 DOI: 10.1371/journal.pone.0182743] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 07/24/2017] [Indexed: 01/22/2023] Open
Abstract
In Alzheimer’s disease (AD), dysregulation of intracellular Ca2+ signalling has been observed as an early event prior to the presence of clinical symptoms and is believed to be a crucial factor contributing to AD pathogenesis. Amyloid-β oligomers (AβOs) disturb the N-methyl-D-aspartate receptor (NMDAR)-mediated postsynaptic Ca2+ signalling in response to presynaptic stimulation by increasing the availability of extracellular glutamate as well as directly disturbing the NMDARs. The abnormal Ca2+ response can further lead to impairments in long-term potentiation (LTP), an important process in memory formation. In this study, we develop a mathematical model of a CA1 pyramidal dendritic spine and conduct computational experiments. We use this model to mimic alterations by AβOs under AD conditions to investigate how they are involved in the Ca2+ dysregulation in the dendritic spine. The alterations in glutamate availability, as well as NMDAR availability and activity, are studied both individually and globally. The simulation results suggest that alterations in glutamate availability mostly affect the synaptic response and have limited effects on the extrasynaptic receptors. Moreover, overactivation of extrasynaptic NMDARs in AD is unlikely to be induced by presynaptic stimulation, but by upregulation of the resting level of glutamate, possibly resulting from these alterations. Furthermore, internalisation of synaptic NR2A-NMDAR shows greater damage to the postsynaptic Ca2+ response in comparison with the internalisation of NR2B-NMDARs; thus, the suggested neuroprotective role of the latter is very limited during synaptic transmission in AD. We integrate a CaMKII state transition model with the Ca2+ model to further study the effects of alterations of NMDARs in the CaMKII state transition, an important downstream event in the early phase of LTP. The model reveals that cooperation between NR2A- and NR2B-NMDAR is required for LTP induction. Under AD conditions, internalisation of membrane NMDARs is suggested to be the cause of the loss of synapse numbers by disrupting CaMKII-NMDAR formation.
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Affiliation(s)
- Jingyi Liang
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, New Zealand
| | - Don Kulasiri
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, New Zealand
- * E-mail:
| | - Sandhya Samarasinghe
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, New Zealand
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287
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Towards a Better Understanding of GABAergic Remodeling in Alzheimer's Disease. Int J Mol Sci 2017; 18:ijms18081813. [PMID: 28825683 PMCID: PMC5578199 DOI: 10.3390/ijms18081813] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 12/18/2022] Open
Abstract
γ-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the vertebrate brain. In the past, there has been a major research drive focused on the dysfunction of the glutamatergic and cholinergic neurotransmitter systems in Alzheimer’s disease (AD). However, there is now growing evidence in support of a GABAergic contribution to the pathogenesis of this neurodegenerative disease. Previous studies paint a complex, convoluted and often inconsistent picture of AD-associated GABAergic remodeling. Given the importance of the GABAergic system in neuronal function and homeostasis, in the maintenance of the excitatory/inhibitory balance, and in the processes of learning and memory, such changes in GABAergic function could be an important factor in both early and later stages of AD pathogenesis. Given the limited scope of currently available therapies in modifying the course of the disease, a better understanding of GABAergic remodeling in AD could open up innovative and novel therapeutic opportunities.
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288
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Bosson A, Paumier A, Boisseau S, Jacquier-Sarlin M, Buisson A, Albrieux M. TRPA1 channels promote astrocytic Ca 2+ hyperactivity and synaptic dysfunction mediated by oligomeric forms of amyloid-β peptide. Mol Neurodegener 2017; 12:53. [PMID: 28683776 PMCID: PMC5501536 DOI: 10.1186/s13024-017-0194-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/29/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Excessive synaptic loss is thought to be one of the earliest events in Alzheimer's disease (AD). However, the key mechanisms that maintain plasticity of synapses during adulthood or initiate synapse dysfunction in AD remain unknown. Recent studies suggest that astrocytes contribute to functional changes observed during synaptic plasticity and play a major role in synaptic dysfunction but astrocytes behavior and involvement in early phases of AD remained largely undefined. METHODS We measure astrocytic calcium activity in mouse CA1 hippocampus stratum radiatum in both the global astrocytic population and at a single cell level, focusing in the highly compartmentalized astrocytic arbor. Concurrently, we measure excitatory post-synaptic currents in nearby pyramidal neurons. RESULTS We find that application of soluble Aβ oligomers (Aβo) induced fast and widespread calcium hyperactivity in the astrocytic population and in the microdomains of the astrocyte arbor. We show that astrocyte hyperactivity is independent of neuronal activity and is repaired by transient receptor potential A1 (TRPA1) channels blockade. In return, this TRPA1 channels-dependent hyperactivity influences neighboring CA1 neurons triggering an increase in glutamatergic spontaneous activity. Interestingly, in an AD mouse model (APP/PS1-21 mouse), astrocyte calcium hyperactivity equally takes place at the beginning of Aβ production, depends on TRPA1 channels and is linked to CA1 neurons hyperactivity. CONCLUSIONS Our experiments demonstrate that astrocytes contribute to early Aβo toxicity exhibiting a global and local Ca2+ hyperactivity that involves TRPA1 channels and is related to neuronal hyperactivity. Together, our data suggest that astrocyte is a frontline target of Aβo and highlight a novel mechanism for the understanding of early synaptic dysregulation induced by soluble Aβo species.
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Affiliation(s)
- Anthony Bosson
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
| | - Adrien Paumier
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
| | - Sylvie Boisseau
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
| | - Muriel Jacquier-Sarlin
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
| | - Alain Buisson
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
| | - Mireille Albrieux
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
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289
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Plá V, Barranco N, Pozas E, Aguado F. Amyloid-β Impairs Vesicular Secretion in Neuronal and Astrocyte Peptidergic Transmission. Front Mol Neurosci 2017; 10:202. [PMID: 28701919 PMCID: PMC5487408 DOI: 10.3389/fnmol.2017.00202] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/08/2017] [Indexed: 12/17/2022] Open
Abstract
Regulated secretion of neuropeptides and neurotrophic factors critically modulates function and plasticity of synapses and circuitries. It is believed that rising amyloid-β (Aβ) concentrations, synaptic dysfunction and network disorganization underlie early phases of Alzheimer’s disease (AD). Here, we analyze the impact of soluble Aβ1–42 assemblies on peptidergic secretion in cortical neurons and astrocytes. We show that neurons and astrocytes differentially produce and release carboxypeptidase E (CPE) and secretogranin III (SgIII), two dense-core vesicle (DCV) markers belonging to the regulated secretory pathway. Importantly, Aβ1–42, but not scrambled Aβ1–42, dramatically impairs basal and Ca2+-regulated secretions of endogenously produced CPE and SgIII in cultured neurons and astrocytes. Additionally, KCl-evoked secretion of the DCV cargo brain-derived neurotrophic factor (BDNF) is lowered by Aβ1–42 administration, whereas glutamate release from synaptic vesicle (SVs) remains unchanged. In agreement with cell culture results, Aβ1–42 effects on CPE and SgIII secretion are faithfully recapitulated in acute adult brain slices. These results demonstrate that neuronal and astrocyte secretion of DCV cargos is impaired by Aβ in vitro and in situ. Furthermore, Aβ-induced dysregulated peptidergic transmission could have an important role in the pathogenesis of AD and DCV cargos are possible candidates as cerebrospinal fluid (CSF) biomarkers.
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Affiliation(s)
- Virginia Plá
- Department of Cell Biology, Physiology and Immunology, University of BarcelonaBarcelona, Spain.,Institute of Neurosciences, University of BarcelonaBarcelona, Spain
| | - Neus Barranco
- Department of Cell Biology, Physiology and Immunology, University of BarcelonaBarcelona, Spain.,Institute of Neurosciences, University of BarcelonaBarcelona, Spain
| | - Esther Pozas
- Department of Cell Biology, Physiology and Immunology, University of BarcelonaBarcelona, Spain
| | - Fernando Aguado
- Department of Cell Biology, Physiology and Immunology, University of BarcelonaBarcelona, Spain.,Institute of Neurosciences, University of BarcelonaBarcelona, Spain
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290
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Marsh J, Bagol SH, Williams RSB, Dickson G, Alifragis P. Synapsin I phosphorylation is dysregulated by beta-amyloid oligomers and restored by valproic acid. Neurobiol Dis 2017. [PMID: 28647556 DOI: 10.1016/j.nbd.2017.06.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Alzheimer's disease is the most prevalent form of dementia in the elderly but the precise causal mechanisms are still not fully understood. Growing evidence supports a significant role for Aβ42 oligomers in the development and progression of Alzheimer's. For example, intracellular soluble Aβ oligomers are thought to contribute to the early synaptic dysfunction associated with Alzheimer's disease, but the molecular mechanisms underlying this effect are still unclear. Here, we identify a novel mechanism that contributes to our understanding of the reported synaptic dysfunction. Using primary rat hippocampal neurons exposed for a short period of time to Aβ42 oligomers, we show a disruption in the activity-dependent phosphorylation cycle of SynapsinI at Ser9. SynapsinI is a pre-synaptic protein that responds to neuronal activity and regulates the availability of synaptic vesicles to participate in neurotransmitter release. Phosphorylation of SynapsinI at Ser9, modulates its distribution and interaction with synaptic vesicles. Our results show that in neurons exposed to Aβ42 oligomers, the levels of phosphorylated Ser9 of SynapsinI remain elevated during the recovery period following neuronal activity. We then investigated if this effect could be targeted by a putative therapeutic regime using valproic acid (a short branch-chained fatty acid) that has been proposed as a treatment for Alzheimer's disease. Exposure of Aβ42 treated neurons to valproic acid, showed that it restores the physiological regulation of SynapsinI after depolarisation. Our data provide a new insight on Aβ42-mediated pathology in Alzheimer's disease and supports the use of Valproic acid as a possible pharmaceutical intervention for the treatment of Alzheimer's disease.
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Affiliation(s)
- Jade Marsh
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Saifuddien Haji Bagol
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Robin S B Williams
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - George Dickson
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Pavlos Alifragis
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK.
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291
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Valls-Comamala V, Guivernau B, Bonet J, Puig M, Perálvarez-Marín A, Palomer E, Fernàndez-Busquets X, Altafaj X, Tajes M, Puig-Pijoan A, Vicente R, Oliva B, Muñoz FJ. The antigen-binding fragment of human gamma immunoglobulin prevents amyloid β-peptide folding into β-sheet to form oligomers. Oncotarget 2017; 8:41154-41165. [PMID: 28467807 PMCID: PMC5522293 DOI: 10.18632/oncotarget.17074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/22/2017] [Indexed: 02/05/2023] Open
Abstract
The amyloid beta-peptide (Aβ) plays a leading role in Alzheimer's disease (AD) physiopathology. Even though monomeric forms of Aβ are harmless to cells, Aβ can aggregate into β-sheet oligomers and fibrils, which are both neurotoxic. Therefore, one of the main therapeutic approaches to cure or delay AD onset and progression is targeting Aβ aggregation. In the present study, we show that a pool of human gamma immunoglobulins (IgG) protected cortical neurons from the challenge with Aβ oligomers, as assayed by MTT reduction, caspase-3 activation and cytoskeleton integrity. In addition, we report the inhibitory effect of IgG on Aβ aggregation, as shown by Thioflavin T assay, size exclusion chromatography and atomic force microscopy. Similar results were obtained with Palivizumab, a human anti-sincitial virus antibody. In order to dissect the important domains, we cleaved the pool of human IgG with papain to obtain Fab and Fc fragments. Using these cleaved fragments, we functionally identified Fab as the immunoglobulin fragment inhibiting Aβ aggregation, a result that was further confirmed by an in silico structural model. Interestingly, bioinformatic tools show a highly conserved structure able to bind amyloid in the Fab region. Overall, our data strongly support the inhibitory effect of human IgG on Aβ aggregation and its neuroprotective role.
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Affiliation(s)
- Victòria Valls-Comamala
- Laboratory of Molecular Physiology, Faculty of Health and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Biuse Guivernau
- Laboratory of Molecular Physiology, Faculty of Health and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Jaume Bonet
- Laboratory of Structural Bioinformatics (GRIB), Faculty of Health and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Marta Puig
- Laboratory of Molecular Physiology, Faculty of Health and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Alex Perálvarez-Marín
- Unitat de Biofísica, Departament de Bioquímica i de Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Ernest Palomer
- Laboratory of Molecular Physiology, Faculty of Health and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Xavier Fernàndez-Busquets
- Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
- ISGlobal, Barcelona Centre for International Health Research, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Xavier Altafaj
- Bellvitge Biomedical Research Institute (IDIBELL) - Unit of Neuropharmacology and Pain, University of Barcelona, Barcelona, Spain
| | - Marta Tajes
- Heart Diseases Biomedical Research Group, IMIM-Hospital del Mar Medical Research Institute, Barcelona, Spain
| | - Albert Puig-Pijoan
- Servei de Neurologia, Hospital del Mar-IMIM-Parc de Salut Mar, Barcelona, Spain
| | - Rubén Vicente
- Laboratory of Molecular Physiology, Faculty of Health and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Baldomero Oliva
- Laboratory of Structural Bioinformatics (GRIB), Faculty of Health and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Francisco J. Muñoz
- Laboratory of Molecular Physiology, Faculty of Health and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
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292
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Hettiarachchi NT, Boyle JP, Dallas ML, Al-Owais MM, Scragg JL, Peers C. Heme oxygenase-1 derived carbon monoxide suppresses Aβ 1-42 toxicity in astrocytes. Cell Death Dis 2017; 8:e2884. [PMID: 28617444 PMCID: PMC5520931 DOI: 10.1038/cddis.2017.276] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 04/19/2017] [Accepted: 05/12/2017] [Indexed: 12/27/2022]
Abstract
Neurodegeneration in Alzheimer's disease (AD) is extensively studied, and the involvement of astrocytes and other cell types in this process has been described. However, the responses of astrocytes themselves to amyloid β peptides ((Aβ; the widely accepted major toxic factor in AD) is less well understood. Here, we show that Aβ(1-42) is toxic to primary cultures of astrocytes. Toxicity does not involve disruption of astrocyte Ca2+ homeostasis, but instead occurs via formation of the toxic reactive species, peroxynitrite. Thus, Aβ(1-42) raises peroxynitrite levels in astrocytes, and Aβ(1-42) toxicity can be inhibited by antioxidants, or by inhibition of nitric oxide (NO) formation (reactive oxygen species (ROS) and NO combine to form peroxynitrite), or by a scavenger of peroxynitrite. Increased ROS levels observed following Aβ(1-42) application were derived from NADPH oxidase. Induction of haem oxygenase-1 (HO-1) protected astrocytes from Aβ(1-42) toxicity, and this protective effect was mimicked by application of the carbon monoxide (CO) releasing molecule CORM-2, suggesting HO-1 protection was attributable to its formation of CO. CO suppressed the rise of NADPH oxidase-derived ROS caused by Aβ(1-42). Under hypoxic conditions (0.5% O2, 48 h) HO-1 was induced in astrocytes and Aβ(1-42) toxicity was significantly reduced, an effect which was reversed by the specific HO-1 inhibitor, QC-15. Our data suggest that Aβ(1-42) is toxic to astrocytes, but that induction of HO-1 affords protection against this toxicity due to formation of CO. HO-1 induction, or CO donors, would appear to present attractive possible approaches to provide protection of both neuronal and non-neuronal cell types from the degenerative effects of AD in the central nervous system.
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Affiliation(s)
- Nishani T Hettiarachchi
- Division of Cardiovascular and Diabetes Research, LICAMM Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | - John P Boyle
- Division of Cardiovascular and Diabetes Research, LICAMM Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | - Mark L Dallas
- Reading School of Pharmacy, University of Reading, Reading, RG6 6UB, UK
| | - Moza M Al-Owais
- Division of Cardiovascular and Diabetes Research, LICAMM Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | - Jason L Scragg
- Division of Cardiovascular and Diabetes Research, LICAMM Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | - Chris Peers
- Division of Cardiovascular and Diabetes Research, LICAMM Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
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293
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Miyamoto T, Stein L, Thomas R, Djukic B, Taneja P, Knox J, Vossel K, Mucke L. Phosphorylation of tau at Y18, but not tau-fyn binding, is required for tau to modulate NMDA receptor-dependent excitotoxicity in primary neuronal culture. Mol Neurodegener 2017; 12:41. [PMID: 28526038 PMCID: PMC5438564 DOI: 10.1186/s13024-017-0176-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 04/26/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Hyperexcitability of neuronal networks can lead to excessive release of the excitatory neurotransmitter glutamate, which in turn can cause neuronal damage by overactivating NMDA-type glutamate receptors and related signaling pathways. This process (excitotoxicity) has been implicated in the pathogenesis of many neurological conditions, ranging from childhood epilepsies to stroke and neurodegenerative disorders such as Alzheimer's disease (AD). Reducing neuronal levels of the microtubule-associated protein tau counteracts network hyperexcitability of diverse causes, but whether this strategy can also diminish downstream excitotoxicity is less clear. METHODS We established a cell-based assay to quantify excitotoxicity in primary cultures of mouse hippocampal neurons and investigated the role of tau in exicitotoxicity by modulating neuronal tau expression through genetic ablation or transduction with lentiviral vectors expressing anti-tau shRNA or constructs encoding wildtype versus mutant mouse tau. RESULTS We demonstrate that shRNA-mediated knockdown of tau reduces glutamate-induced, NMDA receptor-dependent Ca2+ influx and neurotoxicity in neurons from wildtype mice. Conversely, expression of wildtype mouse tau enhances Ca2+ influx and excitotoxicity in tau-deficient (Mapt -/-) neurons. Reconstituting tau expression in Mapt -/- neurons with mutant forms of tau reveals that the tau-related enhancement of Ca2+ influx and excitotoxicity depend on the phosphorylation of tau at tyrosine 18 (pY18), which is mediated by the tyrosine kinase Fyn. These effects are most evident at pathologically elevated concentrations of glutamate, do not involve GluN2B-containing NMDA receptors, and do not require binding of Fyn to tau's major interacting PxxP motif or of tau to microtubules. CONCLUSIONS Although tau has been implicated in diverse neurological diseases, its most pathogenic forms remain to be defined. Our study suggests that reducing the formation or level of pY18-tau can counteract excitotoxicity by diminishing NMDA receptor-dependent Ca2+ influx.
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Affiliation(s)
- Takashi Miyamoto
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA.,Department of Neurology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Liana Stein
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA.,Department of Neurology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Reuben Thomas
- Gladstone Institutes, Convergence Zone, 1650 Owens Street, San Francisco, CA, 94158, USA
| | - Biljana Djukic
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA
| | - Praveen Taneja
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA
| | - Joseph Knox
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA
| | - Keith Vossel
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA.,Department of Neurology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Lennart Mucke
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, CA, 94158, USA. .,Department of Neurology, University of California, San Francisco, San Francisco, CA, 94158, USA.
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294
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Acosta C, Anderson HD, Anderson CM. Astrocyte dysfunction in Alzheimer disease. J Neurosci Res 2017; 95:2430-2447. [PMID: 28467650 DOI: 10.1002/jnr.24075] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/07/2017] [Accepted: 04/10/2017] [Indexed: 12/11/2022]
Abstract
Astrocytes are glial cells that are distributed throughout the central nervous system in an arrangement optimal for chemical and physical interaction with neuronal synapses and brain blood supply vessels. Neurotransmission modulates astrocytic excitability by activating an array of cell surface receptors and transporter proteins, resulting in dynamic changes in intracellular Ca2+ or Na+ . Ionic and electrogenic astrocytic changes, in turn, drive vital cell nonautonomous effects supporting brain function, including regulation of synaptic activity, neuronal metabolism, and regional blood supply. Alzheimer disease (AD) is associated with aberrant oligomeric amyloid β generation, which leads to extensive proliferation of astrocytes with a reactive phenotype and abnormal regulation of these processes. Astrocytic morphology, Ca2+ responses, extracellular K+ removal, glutamate transport, amyloid clearance, and energy metabolism are all affected in AD, resulting in a deleterious set of effects that includes glutamate excitotoxicity, impaired synaptic plasticity, reduced carbon delivery to neurons for oxidative phosphorylation, and dysregulated linkages between neuronal energy demand and regional blood supply. This review summarizes how astrocytes are affected in AD and describes how these changes are likely to influence brain function. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Crystal Acosta
- Department of Pharmacology and Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Research, Winnipeg, Manitoba, Canada
| | - Hope D Anderson
- Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Research, Winnipeg, Manitoba, Canada.,College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Christopher M Anderson
- Department of Pharmacology and Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Neuroscience Research Program, Kleysen Institute for Advanced Medicine, Health Sciences Centre, Winnipeg, Manitoba, Canada
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295
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Li K, Wei Q, Liu FF, Hu F, Xie AJ, Zhu LQ, Liu D. Synaptic Dysfunction in Alzheimer's Disease: Aβ, Tau, and Epigenetic Alterations. Mol Neurobiol 2017; 55:3021-3032. [PMID: 28456942 DOI: 10.1007/s12035-017-0533-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/06/2017] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized in the early stages by loss of learning and memory. However, the mechanism underlying these symptoms remains unclear. The best correlation between cognitive decline and pathological changes is in synaptic dysfunction. Histopathological hallmarks of AD are the abnormal aggregation of Aβ and Tau. Evidence suggests that Aβ and Tau oligomers contribute to synaptic loss in AD. Recently, direct links between epigenetic alterations, such as dysfunction in non-coding RNAs (ncRNAs), and synaptic pathologies have emerged, raising interest in exploring the potential roles of ncRNAs in the synaptic deficits in AD. In this paper, we summarize the potential roles of Aβ, Tau, and epigenetic alterations (especially by ncRNAs) in the synaptic dysfunction of AD and discuss the novel findings in this area.
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Affiliation(s)
- Ke Li
- Department of Blood Transfusion, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Qing Wei
- Department of Blood Transfusion, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Fang-Fang Liu
- Department of Pathology, Central Hospital of Wuhan, Wuhan, 430014, People's Republic of China
| | - Fan Hu
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Ao-Ji Xie
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Ling-Qiang Zhu
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.
| | - Dan Liu
- Department of Medical Genetics, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.
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296
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Zhang D, Qi Y, Klyubin I, Ondrejcak T, Sarell CJ, Cuello AC, Collinge J, Rowan MJ. Targeting glutamatergic and cellular prion protein mechanisms of amyloid β-mediated persistent synaptic plasticity disruption: Longitudinal studies. Neuropharmacology 2017; 121:231-246. [PMID: 28390893 DOI: 10.1016/j.neuropharm.2017.03.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 03/08/2017] [Accepted: 03/30/2017] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease amyloid-β (Aβ) oligomers are synaptotoxic, inappropriately increasing extracellular glutamate concentration and glutamate receptor activation to thereby rapidly disrupt synaptic plasticity. Thus, acutely promoting brain glutamate homeostasis with a blood-based scavenging system, glutamate-oxaloacetate transaminase (GOT), and blocking metabotropic glutamate 5 (mGlu5) receptor or its co-receptor cellular prion protein (PrP), prevent the acute inhibition of long-term potentiation (LTP) by exogenous Aβ. Here, we evaluated the time course of the effects of such interventions in the persistent disruptive effects of Aβ oligomers, either exogenously injected in wild type rats or endogenously generated in transgenic rats that model Alzheimer's disease amyloidosis. We report that repeated, but not acute, systemic administration of recombinant GOT type 1, with or without the glutamate co-substrate oxaloacetate, reversed the persistent deleterious effect of exogenous Aβ on synaptic plasticity. Moreover, similar repetitive treatment reversibly abrogated the inhibition of LTP monitored longitudinally in freely behaving transgenic rats. Remarkably, brief repeated treatment with an mGlu5 receptor antagonist, basimglurant, or an antibody that prevents Aβ oligomer binding to PrP, ICSM35, also had similar reversible ameliorative effects in the transgenic rat model. Overall, the present findings support the ongoing development of therapeutics for early Alzheimer's disease based on these complementary approaches.
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Affiliation(s)
- Dainan Zhang
- Department of Pharmacology & Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland; Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; Center for Neurological Diseases (NCRC-ND), Beijing, China
| | - Yingjie Qi
- Department of Pharmacology & Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
| | - Igor Klyubin
- Department of Pharmacology & Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Tomas Ondrejcak
- Department of Pharmacology & Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Claire J Sarell
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, Department of Neurology and Neurosurgery, Department of Anatomy and Cell Biology, McGill University, Montreal, Canada
| | - John Collinge
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Michael J Rowan
- Department of Pharmacology & Therapeutics, and Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
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297
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Lane-Donovan C, Herz J. ApoE, ApoE Receptors, and the Synapse in Alzheimer's Disease. Trends Endocrinol Metab 2017; 28:273-284. [PMID: 28057414 PMCID: PMC5366078 DOI: 10.1016/j.tem.2016.12.001] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 11/29/2016] [Accepted: 12/07/2016] [Indexed: 01/24/2023]
Abstract
As the population ages, neurodegenerative diseases such as Alzheimer's disease (AD) are becoming a significant burden on patients, their families, and health-care systems. Neurodegenerative processes may start up to 15 years before outward signs and symptoms of AD, as evidenced by data from AD patients and mouse models. A major genetic risk factor for late-onset AD is the ɛ4 isoform of apolipoprotein E (ApoE4), which is present in almost 20% of the population. In this review we discuss the contribution of ApoE receptor signaling to the function of each component of the tripartite synapse - the axon terminal, the postsynaptic dendritic spine, and the astrocyte - and examine how these systems fail in the context of ApoE4 and AD.
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Affiliation(s)
- Courtney Lane-Donovan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Center for Neuroscience, Department of Neuroanatomy, Albert Ludwig University, Freiburg, Germany.
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298
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Arbel-Ornath M, Hudry E, Boivin JR, Hashimoto T, Takeda S, Kuchibhotla KV, Hou S, Lattarulo CR, Belcher AM, Shakerdge N, Trujillo PB, Muzikansky A, Betensky RA, Hyman BT, Bacskai BJ. Soluble oligomeric amyloid-β induces calcium dyshomeostasis that precedes synapse loss in the living mouse brain. Mol Neurodegener 2017; 12:27. [PMID: 28327181 PMCID: PMC5361864 DOI: 10.1186/s13024-017-0169-9] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 03/17/2017] [Indexed: 02/06/2023] Open
Abstract
Background Amyloid-β oligomers (oAβ) are thought to mediate neurotoxicity in Alzheimer’s disease (AD), and previous studies in AD transgenic mice suggest that calcium dysregulation may contribute to these pathological effects. Even though AD mouse models remain a valuable resource to investigate amyloid neurotoxicity, the concomitant presence of soluble Aβ species, fibrillar Aβ, and fragments of amyloid precursor protein (APP) complicate the interpretation of the phenotypes. Method To explore the specific contribution of soluble oligomeric Aβ (oAβ) to calcium dyshomeostasis and synaptic morphological changes, we acutely exposed the healthy mouse brain, at 3 to 6 months of age, to naturally occurring soluble oligomers and investigated their effect on calcium levels using in vivo multiphoton imaging. Results We observed a dramatic increase in the levels of neuronal resting calcium, which was dependent upon extracellular calcium influx and activation of NMDA receptors. Ryanodine receptors, previously implicated in AD models, did not appear to be primarily involved using this experimental setting. We used the high resolution cortical volumes acquired in-vivo to measure the effect on synaptic densities and observed that, while spine density remained stable within the first hour of oAβ exposure, a significant decrease in the number of dendritic spines was observed 24 h post treatment, despite restoration of intraneuronal calcium levels at this time point. Conclusions These observations demonstrate a specific effect of oAβ on NMDA-mediated calcium influx, which triggers synaptic collapse in vivo. Moreover, this work leverages a method to quantitatively measure calcium concentration at the level of neuronal processes, cell bodies and single synaptic elements repeatedly and thus can be applicable to testing putative drugs and/or other intervention methodologies. Electronic supplementary material The online version of this article (doi:10.1186/s13024-017-0169-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michal Arbel-Ornath
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA
| | - Eloise Hudry
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA
| | - Josiah R Boivin
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA
| | - Tadafumi Hashimoto
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA.,Department of Neuropathology, The University of Tokyo, Tokyo, Japan
| | - Shuko Takeda
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA
| | - Kishore V Kuchibhotla
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA.,Skirball Institute, NYU School of Medicine, New York, NY, 10016, USA
| | - Steven Hou
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA
| | - Carli R Lattarulo
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA
| | - Arianna M Belcher
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA
| | - Naomi Shakerdge
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA
| | - Pariss B Trujillo
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA
| | - Alona Muzikansky
- Department of Biostatistics, Harvard School of Public Health, 50 Staniford Street, Boston, MA, USA
| | - Rebecca A Betensky
- Department of Biostatistics, Harvard School of Public Health, 50 Staniford Street, Boston, MA, USA
| | - Bradley T Hyman
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA
| | - Brian J Bacskai
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St., Charlestown, MA, 02129, USA.
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299
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Seixas da Silva GS, Melo HM, Lourenco MV, Lyra E Silva NM, de Carvalho MB, Alves-Leon SV, de Souza JM, Klein WL, da-Silva WS, Ferreira ST, De Felice FG. Amyloid-β oligomers transiently inhibit AMP-activated kinase and cause metabolic defects in hippocampal neurons. J Biol Chem 2017; 292:7395-7406. [PMID: 28302722 DOI: 10.1074/jbc.m116.753525] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 03/15/2017] [Indexed: 11/06/2022] Open
Abstract
AMP-activated kinase (AMPK) is a key player in energy sensing and metabolic reprogramming under cellular energy restriction. Several studies have linked impaired AMPK function to peripheral metabolic diseases such as diabetes. However, the impact of neurological disorders, such as Alzheimer disease (AD), on AMPK function and downstream effects of altered AMPK activity on neuronal metabolism have been investigated only recently. Here, we report the impact of Aβ oligomers (AβOs), synaptotoxins that accumulate in AD brains, on neuronal AMPK activity. Short-term exposure of cultured rat hippocampal neurons or ex vivo human cortical slices to AβOs transiently decreased intracellular ATP levels and AMPK activity, as evaluated by its phosphorylation at threonine residue 172 (AMPK-Thr(P)172). The AβO-dependent reduction in AMPK-Thr(P)172 levels was mediated by glutamate receptors of the N-methyl-d-aspartate (NMDA) subtype and resulted in removal of glucose transporters (GLUTs) from the surfaces of dendritic processes in hippocampal neurons. Importantly, insulin prevented the AβO-induced inhibition of AMPK. Our results establish a novel toxic impact of AβOs on neuronal metabolism and suggest that AβO-induced, NMDA receptor-mediated AMPK inhibition may play a key role in early brain metabolic defects in AD.
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Affiliation(s)
| | - Helen M Melo
- From the Institute of Medical Biochemistry Leopoldo de Meis and
| | - Mychael V Lourenco
- From the Institute of Medical Biochemistry Leopoldo de Meis and.,the Institute of Biophysics Carlos Chagas Filho
| | | | | | | | - Jorge M de Souza
- Neurosurgery, Clementino Fraga Filho Hospital, Federal University of Rio De Janeiro, Rio de Janeiro 21941-902, Brazil
| | - William L Klein
- the Department of Neurobiology, Northwestern University, Evanston, Illinois 60208-3520, and
| | | | - Sergio T Ferreira
- From the Institute of Medical Biochemistry Leopoldo de Meis and.,the Institute of Biophysics Carlos Chagas Filho
| | - Fernanda G De Felice
- From the Institute of Medical Biochemistry Leopoldo de Meis and .,the Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
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300
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Blanco‐Suárez E, Caldwell ALM, Allen NJ. Role of astrocyte-synapse interactions in CNS disorders. J Physiol 2017; 595:1903-1916. [PMID: 27381164 PMCID: PMC5350444 DOI: 10.1113/jp270988] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 06/08/2016] [Indexed: 12/18/2022] Open
Abstract
Astrocytes comprise half of the cells in the brain. Although astrocytes have traditionally been described as playing a supportive role for neurons, they have recently been recognized as active participants in the development and plasticity of dendritic spines and synapses. Astrocytes can eliminate dendritic spines, induce synapse formation, and regulate neurotransmission and plasticity. Dendritic spine and synapse impairments are features of many neurological disorders, including autism spectrum disorder, schizophrenia, and Alzheimer's disease. In this review we will present evidence from multiple neurological disorders demonstrating that changes in astrocyte-synapse interaction contribute to the pathologies. Genomic analysis has connected altered astrocytic gene expression with synaptic deficits in a number of neurological disorders. Alterations in astrocyte-secreted factors have been implicated in the neuronal morphology and synaptic changes seen in neurodevelopmental disorders, while alteration in astrocytic glutamate uptake is a core feature of multiple neurodegenerative disorders. This evidence clearly demonstrates that maintaining astrocyte-synapse interaction is crucial for normal central nervous system functioning. Obtaining a better understanding of the role of astrocytes at synapses in health and disease will provide a new avenue for future therapeutic targeting.
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Affiliation(s)
- Elena Blanco‐Suárez
- Salk Institute for Biological StudiesMolecular Neuroscience Laboratory10010 North Torrey Pines RdLa JollaCA92037USA
| | - Alison L. M. Caldwell
- Salk Institute for Biological StudiesMolecular Neuroscience Laboratory10010 North Torrey Pines RdLa JollaCA92037USA
| | - Nicola J. Allen
- Salk Institute for Biological StudiesMolecular Neuroscience Laboratory10010 North Torrey Pines RdLa JollaCA92037USA
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