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McIntyre RS, Jain R. Glutamatergic Modulators for Major Depression from Theory to Clinical Use. CNS Drugs 2024:10.1007/s40263-024-01114-y. [PMID: 39150594 DOI: 10.1007/s40263-024-01114-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/22/2024] [Indexed: 08/17/2024]
Abstract
Major depressive disorder (MDD) is a chronic, burdensome, highly prevalent disease that is characterized by depressed mood and anhedonia. MDD is especially burdensome as approved monoamine antidepressant treatments have weeks-long delays before clinical benefit and low remission rates. In the past 2 decades, a promising target emerged to improve patient outcomes in depression treatment: glutamatergic signaling. This narrative review provides a high-level overview of glutamate signaling in synaptogenesis and neural plasticity and the implications of glutamate dysregulation in depression. Based on this preclinical evidence implicating glutamate in depression and the rapid improvement of depression with ketamine treatment in a proof-of-concept trial, a range of N-methyl-D-aspartate (NMDA)-targeted therapies have been investigated. While an array of treatments has been investigated in registered phase 2 or 3 clinical trials, the development of most of these agents has been discontinued. Multiple glutamate-targeted antidepressants are actively in development, and two are approved. Nasal administration of esketamine (Spravato®) was approved by the US Food and Drug Administration (FDA) in 2019 to treat adults with treatment-resistant depression and in 2020 for adults with MDD with acute suicidal ideation or behavior. Oral combination dextromethorphan-bupropion (AXS-05, Auvelity® extended-release tablet) was FDA approved in 2022 for the treatment of MDD in adults. These approvals bolster the importance of glutamate in depression and represent an exciting breakthrough in contemporary psychiatry, providing new avenues of treatment for patients as first-line therapy or with either poor response or unacceptable side effects to monoaminergic antidepressants.
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Affiliation(s)
- Roger S McIntyre
- University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Department of Pharmacology, University of Toronto, Toronto, ON, Canada
| | - Rakesh Jain
- Department of Psychiatry, Texas Tech University School of Medicine-Permian Basin, Midland, TX, USA.
- Texas Tech University School of Medicine-Permian Basin, 2500 W William Cannon Drive, Suite 505, Austin, Texas, 78745, USA.
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2
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Pinoșanu EA, Pîrșcoveanu D, Albu CV, Burada E, Pîrvu A, Surugiu R, Sandu RE, Serb AF. Rhoa/ROCK, mTOR and Secretome-Based Treatments for Ischemic Stroke: New Perspectives. Curr Issues Mol Biol 2024; 46:3484-3501. [PMID: 38666949 PMCID: PMC11049286 DOI: 10.3390/cimb46040219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Ischemic stroke triggers a complex cascade of cellular and molecular events leading to neuronal damage and tissue injury. This review explores the potential therapeutic avenues targeting cellular signaling pathways implicated in stroke pathophysiology. Specifically, it focuses on the articles that highlight the roles of RhoA/ROCK and mTOR signaling pathways in ischemic brain injury and their therapeutic implications. The RhoA/ROCK pathway modulates various cellular processes, including cytoskeletal dynamics and inflammation, while mTOR signaling regulates cell growth, proliferation, and autophagy. Preclinical studies have demonstrated the neuroprotective effects of targeting these pathways in stroke models, offering insights into potential treatment strategies. However, challenges such as off-target effects and the need for tissue-specific targeting remain. Furthermore, emerging evidence suggests the therapeutic potential of MSC secretome in stroke treatment, highlighting the importance of exploring alternative approaches. Future research directions include elucidating the precise mechanisms of action, optimizing treatment protocols, and translating preclinical findings into clinical practice for improved stroke outcomes.
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Affiliation(s)
- Elena Anca Pinoșanu
- Department of Neurology, University of Medicine and Pharmacy of Craiova, St. Petru Rares, No. 2-4, 200433 Craiova, Romania; (E.A.P.); (D.P.); (C.V.A.)
- Doctoral School, University of Medicine and Pharmacy of Craiova, St. Petru Rares, No. 2-4, 200433 Craiova, Romania
| | - Denisa Pîrșcoveanu
- Department of Neurology, University of Medicine and Pharmacy of Craiova, St. Petru Rares, No. 2-4, 200433 Craiova, Romania; (E.A.P.); (D.P.); (C.V.A.)
| | - Carmen Valeria Albu
- Department of Neurology, University of Medicine and Pharmacy of Craiova, St. Petru Rares, No. 2-4, 200433 Craiova, Romania; (E.A.P.); (D.P.); (C.V.A.)
| | - Emilia Burada
- Department of Physiology, University of Medicine and Pharmacy of Craiova, St. Petru Rares, No. 2-4, 200433 Craiova, Romania;
| | - Andrei Pîrvu
- Dolj County Regional Centre of Medical Genetics, Clinical Emergency County Hospital Craiova, St. Tabaci, No. 1, 200642 Craiova, Romania;
| | - Roxana Surugiu
- Department of Biochemistry, University of Medicine and Pharmacy of Craiova, St. Petru Rares, No. 2-4, 200433 Craiova, Romania;
| | - Raluca Elena Sandu
- Department of Neurology, University of Medicine and Pharmacy of Craiova, St. Petru Rares, No. 2-4, 200433 Craiova, Romania; (E.A.P.); (D.P.); (C.V.A.)
- Department of Biochemistry, University of Medicine and Pharmacy of Craiova, St. Petru Rares, No. 2-4, 200433 Craiova, Romania;
| | - Alina Florina Serb
- Department of Biochemistry and Pharmacology, Biochemistry Discipline, “Victor Babes” University of Medicine and Pharmacy, Eftimie Murgu Sq., No. 2, 300041 Timisoara, Romania;
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3
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Fan G, Liu M, Liu J, Huang Y. The initiator of neuroexcitotoxicity and ferroptosis in ischemic stroke: Glutamate accumulation. Front Mol Neurosci 2023; 16:1113081. [PMID: 37033381 PMCID: PMC10076579 DOI: 10.3389/fnmol.2023.1113081] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 03/06/2023] [Indexed: 04/11/2023] Open
Abstract
Glutamate plays an important role in excitotoxicity and ferroptosis. Excitotoxicity occurs through over-stimulation of glutamate receptors, specifically NMDAR, while in the non-receptor-mediated pathway, high glutamate concentrations reduce cystine uptake by inhibiting the System Xc-, leading to intracellular glutathione depletion and resulting in ROS accumulation, which contributes to increased lipid peroxidation, mitochondrial damage, and ultimately ferroptosis. Oxidative stress appears to crosstalk between excitotoxicity and ferroptosis, and it is essential to maintain glutamate homeostasis and inhibit oxidative stress responses in vivo. As researchers work to develop natural compounds to further investigate the complex mechanisms and regulatory functions of ferroptosis and excitotoxicity, new avenues will be available for the effective treatment of ischaemic stroke. Therefore, this paper provides a review of the molecular mechanisms and treatment of glutamate-mediated excitotoxicity and ferroptosis.
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Affiliation(s)
- Genhao Fan
- Graduate School, Tianjin University of Chinese Medicine, Tianjin, China
| | - Menglin Liu
- Graduate School, Tianjin University of Chinese Medicine, Tianjin, China
| | - Jia Liu
- Department of Clinical Pharmacology, The Second Affiliated Hospital of Tianjin University of Chinese Medicine, Tianjin, China
| | - Yuhong Huang
- Department of Clinical Pharmacology, The Second Affiliated Hospital of Tianjin University of Chinese Medicine, Tianjin, China
- *Correspondence: Yuhong Huang,
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4
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Excitatory Synaptic Transmission in Ischemic Stroke: A New Outlet for Classical Neuroprotective Strategies. Int J Mol Sci 2022; 23:ijms23169381. [PMID: 36012647 PMCID: PMC9409263 DOI: 10.3390/ijms23169381] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/15/2022] [Accepted: 08/17/2022] [Indexed: 01/01/2023] Open
Abstract
Stroke is one of the leading causes of death and disability in the world, of which ischemia accounts for the majority. There is growing evidence of changes in synaptic connections and neural network functions in the brain of stroke patients. Currently, the studies on these neurobiological alterations mainly focus on the principle of glutamate excitotoxicity, and the corresponding neuroprotective strategies are limited to blocking the overactivation of ionic glutamate receptors. Nevertheless, it is disappointing that these treatments often fail because of the unspecificity and serious side effects of the tested drugs in clinical trials. Thus, in the prevention and treatment of stroke, finding and developing new targets of neuroprotective intervention is still the focus and goal of research in this field. In this review, we focus on the whole processes of glutamatergic synaptic transmission and highlight the pathological changes underlying each link to help develop potential therapeutic strategies for ischemic brain damage. These strategies include: (1) controlling the synaptic or extra-synaptic release of glutamate, (2) selectively blocking the action of the glutamate receptor NMDAR subunit, (3) increasing glutamate metabolism, and reuptake in the brain and blood, and (4) regulating the glutamate system by GABA receptors and the microbiota–gut–brain axis. Based on these latest findings, it is expected to promote a substantial understanding of the complex glutamate signal transduction mechanism, thereby providing excellent neuroprotection research direction for human ischemic stroke (IS).
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5
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Discovery of novel donepezil-M30D hybrids with neuroprotective properties for Alzheimer’s disease treatment. Med Chem Res 2022. [DOI: 10.1007/s00044-022-02886-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Revisiting Excitotoxicity in Traumatic Brain Injury: From Bench to Bedside. Pharmaceutics 2022; 14:pharmaceutics14010152. [PMID: 35057048 PMCID: PMC8781803 DOI: 10.3390/pharmaceutics14010152] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/31/2021] [Accepted: 01/05/2022] [Indexed: 12/12/2022] Open
Abstract
Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality. Consequences vary from mild cognitive impairment to death and, no matter the severity of subsequent sequelae, it represents a high burden for affected patients and for the health care system. Brain trauma can cause neuronal death through mechanical forces that disrupt cell architecture, and other secondary consequences through mechanisms such as inflammation, oxidative stress, programmed cell death, and, most importantly, excitotoxicity. This review aims to provide a comprehensive understanding of the many classical and novel pathways implicated in tissue damage following TBI. We summarize the preclinical evidence of potential therapeutic interventions and describe the available clinical evaluation of novel drug targets such as vitamin B12 and ifenprodil, among others.
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APOE4 Affects Basal and NMDAR-Mediated Protein Synthesis in Neurons by Perturbing Calcium Homeostasis. J Neurosci 2021; 41:8686-8709. [PMID: 34475200 DOI: 10.1523/jneurosci.0435-21.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 08/15/2021] [Accepted: 08/22/2021] [Indexed: 01/24/2023] Open
Abstract
Apolipoprotein E (APOE), one of the primary lipoproteins in the brain has three isoforms in humans, APOE2, APOE3, and APOE4. APOE4 is the most well-established risk factor increasing the predisposition for Alzheimer's disease (AD). The presence of the APOE4 allele alone is shown to cause synaptic defects in neurons and recent studies have identified multiple pathways directly influenced by APOE4. However, the mechanisms underlying APOE4-induced synaptic dysfunction remain elusive. Here, we report that the acute exposure of primary cortical neurons or synaptoneurosomes to APOE4 leads to a significant decrease in global protein synthesis. Primary cortical neurons were derived from male and female embryos of Sprague Dawley (SD) rats or C57BL/6J mice. Synaptoneurosomes were prepared from P30 male SD rats. APOE4 treatment also abrogates the NMDA-mediated translation response indicating an alteration of synaptic signaling. Importantly, we demonstrate that both APOE3 and APOE4 generate a distinct translation response which is closely linked to their respective calcium signature. Acute exposure of neurons to APOE3 causes a short burst of calcium through NMDA receptors (NMDARs) leading to an initial decrease in protein synthesis which quickly recovers. Contrarily, APOE4 leads to a sustained increase in calcium levels by activating both NMDARs and L-type voltage-gated calcium channels (L-VGCCs), thereby causing sustained translation inhibition through eukaryotic translation elongation factor 2 (eEF2) phosphorylation, which in turn disrupts the NMDAR response. Thus, we show that APOE4 affects basal and activity-mediated protein synthesis responses in neurons by affecting calcium homeostasis.SIGNIFICANCE STATEMENT Defective protein synthesis has been shown as an early defect in familial Alzheimer's disease (AD). However, this has not been studied in the context of sporadic AD, which constitutes the majority of cases. In our study, we show that Apolipoprotein E4 (APOE4), the predominant risk factor for AD, inhibits global protein synthesis in neurons. APOE4 also affects NMDA activity-mediated protein synthesis response, thus inhibiting synaptic translation. We also show that the defective protein synthesis mediated by APOE4 is closely linked to the perturbation of calcium homeostasis caused by APOE4 in neurons. Thus, we propose the dysregulation of protein synthesis as one of the possible molecular mechanisms to explain APOE4-mediated synaptic and cognitive defects. Hence, the study not only suggests an explanation for the APOE4-mediated predisposition to AD, it also bridges the gap in understanding APOE4-mediated pathology.
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A human stem cell-derived test system for agents modifying neuronal N-methyl-D-aspartate-type glutamate receptor Ca 2+-signalling. Arch Toxicol 2021; 95:1703-1722. [PMID: 33713149 PMCID: PMC8113295 DOI: 10.1007/s00204-021-03024-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 03/04/2021] [Indexed: 12/12/2022]
Abstract
Methods to assess neuronal receptor functions are needed in toxicology and for drug development. Human-based test systems that allow studies on glutamate signalling are still scarce. To address this issue, we developed and characterized pluripotent stem cell (PSC)-based neural cultures capable of forming a functional network. Starting from a stably proliferating neuroepithelial stem cell (NESC) population, we generate “mixed cortical cultures” (MCC) within 24 days. Characterization by immunocytochemistry, gene expression profiling and functional tests (multi-electrode arrays) showed that MCC contain various functional neurotransmitter receptors, and in particular, the N-methyl-d-aspartate subtype of ionotropic glutamate receptors (NMDA-R). As this important receptor is found neither on conventional neural cell lines nor on most stem cell-derived neurons, we focused here on the characterization of rapid glutamate-triggered Ca2+ signalling. Changes of the intracellular free calcium ion concentration ([Ca2+]i) were measured by fluorescent imaging as the main endpoint, and a method to evaluate and quantify signals in hundreds of cells at the same time was developed. We observed responses to glutamate in the low µM range. MCC responded to kainate and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and a subpopulation of 50% had functional NMDA-R. The receptor was modulated by Mg2+, Zn2+ and Pb2+ in the expected ways, and various toxicologically relevant agonists (quinolinic acid, ibotenic acid, domoic acid) triggered [Ca2+]i responses in MCC. Antagonists, such as phencyclidine, ketamine and dextromethorphan, were also readily identified. Thus, the MCC developed here may fill an important gap in the panel of test systems available to characterize the effects of chemicals on neurotransmitter receptors.
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9
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Positive modulation of NMDA receptors by AGN-241751 exerts rapid antidepressant-like effects via excitatory neurons. Neuropsychopharmacology 2021; 46:799-808. [PMID: 33059355 PMCID: PMC8027594 DOI: 10.1038/s41386-020-00882-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/03/2020] [Accepted: 09/29/2020] [Indexed: 12/25/2022]
Abstract
Dysregulation of the glutamatergic system and its receptors in medial prefrontal cortex (mPFC) has been implicated in major depressive disorder. Recent preclinical studies have shown that enhancing NMDA receptor (NMDAR) activity can exert rapid antidepressant-like effects. AGN-241751, an NMDAR positive allosteric modulator (PAM), is currently being tested as an antidepressant in clinical trials, but the mechanism and NMDAR subunit(s) mediating its antidepressant-like effects are unknown. We therefore used molecular, biochemical, and electrophysiological approaches to examine the cell-type-specific role of GluN2B-containing NMDAR in mediating antidepressant-like behavioral effects of AGN-241751. We demonstrate that AGN-241751 exerts antidepressant-like effects and reverses behavioral deficits induced by chronic unpredictable stress in mice. AGN-241751 treatment enhances NMDAR activity of excitatory and parvalbumin-inhibitory neurons in mPFC, activates Akt/mTOR signaling, and increases levels of synaptic proteins crucial for synaptic plasticity in the prefrontal cortex. Furthermore, cell-type-specific knockdown of GluN2B-containing NMDARs in mPFC demonstrates that GluN2B subunits on excitatory, but not inhibitory, neurons are necessary for antidepressant-like effects of AGN-241751. Together, these results demonstrate antidepressant-like actions of the NMDAR PAM AGN-241751 and identify GluN2B on excitatory neurons of mPFC as initial cellular trigger underlying these behavioral effects.
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10
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Hanson JE, Ma K, Elstrott J, Weber M, Saillet S, Khan AS, Simms J, Liu B, Kim TA, Yu GQ, Chen Y, Wang TM, Jiang Z, Liederer BM, Deshmukh G, Solanoy H, Chan C, Sellers BD, Volgraf M, Schwarz JB, Hackos DH, Weimer RM, Sheng M, Gill TM, Scearce-Levie K, Palop JJ. GluN2A NMDA Receptor Enhancement Improves Brain Oscillations, Synchrony, and Cognitive Functions in Dravet Syndrome and Alzheimer's Disease Models. Cell Rep 2021; 30:381-396.e4. [PMID: 31940483 PMCID: PMC7017907 DOI: 10.1016/j.celrep.2019.12.030] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/11/2019] [Accepted: 12/06/2019] [Indexed: 01/28/2023] Open
Abstract
NMDA receptors (NMDARs) play subunit-specific roles in synaptic function and are implicated in neuropsychiatric and neurodegenerative disorders. However, the in vivo consequences and therapeutic potential of pharmacologically enhancing NMDAR function via allosteric modulation are largely un-known. We examine the in vivo effects of GNE-0723, a positive allosteric modulator of GluN2A-subunit-containing NMDARs, on brain network and cognitive functions in mouse models of Dravet syndrome (DS) and Alzheimer’s disease (AD). GNE-0723 use dependently potentiates synaptic NMDA receptor currents and reduces brain oscillation power with a predominant effect on low-frequency (12–20 Hz) oscillations. Interestingly, DS and AD mouse models display aberrant low-frequency oscillatory power that is tightly correlated with network hypersynchrony. GNE-0723 treatment reduces aberrant low-frequency oscillations and epileptiform discharges and improves cognitive functions in DS and AD mouse models. GluN2A-subunit-containing NMDAR enhancers may have therapeutic benefits in brain disorders with network hypersynchrony and cognitive impairments. Hanson et al. examine the therapeutic effects of enhancing GluN2A-subunit-containing NMDAR function in Dravet syndrome and Alzheimer’s disease mice. GNE-0723 treatment reduces aberrant low-frequency oscillations and epileptiform discharges and improves cognitive functions in both disease models. GluN2A NMDAR enhancers may benefit brain disorders with network hypersynchrony and cognitive impairments.
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Affiliation(s)
- Jesse E Hanson
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA.
| | - Keran Ma
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Justin Elstrott
- Department of Biomedical Imaging, Genentech Inc., South San Francisco, CA 94080, USA
| | - Martin Weber
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Sandrine Saillet
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Abdullah S Khan
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Jeffrey Simms
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Benjamin Liu
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Thomas A Kim
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Gui-Qiu Yu
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | - Yelin Chen
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Tzu-Ming Wang
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Zhiyu Jiang
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Bianca M Liederer
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc., South San Francisco, CA 94080, USA
| | - Gauri Deshmukh
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc., South San Francisco, CA 94080, USA
| | - Hilda Solanoy
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Connie Chan
- Department of Pharmaceuticals, Genentech Inc., South San Francisco, CA 94080, USA
| | - Benjamin D Sellers
- Department of Discovery Chemistry, Genentech Inc., South San Francisco, CA 94080, USA
| | - Matthew Volgraf
- Department of Discovery Chemistry, Genentech Inc., South San Francisco, CA 94080, USA
| | - Jacob B Schwarz
- Department of Discovery Chemistry, Genentech Inc., South San Francisco, CA 94080, USA
| | - David H Hackos
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - Robby M Weimer
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA; Department of Biomedical Imaging, Genentech Inc., South San Francisco, CA 94080, USA
| | - Morgan Sheng
- Department of Neuroscience, Genentech Inc., South San Francisco, CA 94080, USA
| | - T Michael Gill
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | | | - Jorge J Palop
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA.
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Choi DW. Excitotoxicity: Still Hammering the Ischemic Brain in 2020. Front Neurosci 2020; 14:579953. [PMID: 33192266 PMCID: PMC7649323 DOI: 10.3389/fnins.2020.579953] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/25/2020] [Indexed: 12/13/2022] Open
Abstract
Interest in excitotoxicity expanded following its implication in the pathogenesis of ischemic brain injury in the 1980s, but waned subsequent to the failure of N-methyl-D-aspartate (NMDA) antagonists in high profile clinical stroke trials. Nonetheless there has been steady progress in elucidating underlying mechanisms. This review will outline the historical path to current understandings of excitotoxicity in the ischemic brain, and suggest that this knowledge should be leveraged now to develop neuroprotective treatments for stroke.
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Affiliation(s)
- Dennis W Choi
- Department of Neurology, SUNY Stony Brook, Stony Brook, NY, United States
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12
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Özgün A, Marote A, Behie LA, Salgado A, Garipcan B. Extremely low frequency magnetic field induces human neuronal differentiation through NMDA receptor activation. J Neural Transm (Vienna) 2019; 126:1281-1290. [PMID: 31317262 DOI: 10.1007/s00702-019-02045-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 07/09/2019] [Indexed: 12/31/2022]
Abstract
Magnetic fields with different frequency and intensity parameters exhibit a wide range of effects on different biological models. Extremely low frequency magnetic field (ELF MF) exposure is known to augment or even initiate neuronal differentiation in several in vitro and in vivo models. This effect holds potential for clinical translation into treatment of neurodegenerative conditions such as autism, Parkinson's disease and dementia by promoting neurogenesis, non-invasively. However, the lack of information on underlying mechanisms hinders further investigation into this phenomenon. Here, we examine involvement of glutamatergic Ca2+ channel, N-methyl-D-aspartate (NMDA) receptors in the process of human neuronal differentiation under ELF MF exposure. We show that human neural progenitor cells (hNPCs) differentiate more efficiently under ELF MF exposure in vitro, as demonstrated by the abundance of neuronal markers. Furthermore, they exhibit higher intracellular Ca2+ levels as evidenced by c-fos expression and more elongated mature neurites. We were able to neutralize these effects by blocking NMDA receptors with memantine. As a result, we hypothesize that the effects of ELF MF exposure on neuronal differentiation originate from the effects on NMDA receptors, which sequentially triggers Ca2+-dependent cascades that lead to differentiation. Our findings identify NMDA receptors as a new key player in this field that will aid further research in the pursuit of effect mechanisms of ELF MFs.
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Affiliation(s)
- Alp Özgün
- Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey
| | - Ana Marote
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, University of Minho, Braga/Guimarães, Portugal
| | - Leo A Behie
- Canada Research Chair in Biomedical Engineering (Emeritus), Schulich School of Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada
| | - António Salgado
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal. .,ICVS/3B's-PT Government Associate Laboratory, University of Minho, Braga/Guimarães, Portugal.
| | - Bora Garipcan
- Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey.
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13
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Tejeda GS, Esteban‐Ortega GM, San Antonio E, Vidaurre ÓG, Díaz‐Guerra M. Prevention of excitotoxicity-induced processing of BDNF receptor TrkB-FL leads to stroke neuroprotection. EMBO Mol Med 2019; 11:e9950. [PMID: 31273936 PMCID: PMC6609917 DOI: 10.15252/emmm.201809950] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 05/02/2019] [Accepted: 05/03/2019] [Indexed: 12/14/2022] Open
Abstract
Neuroprotective strategies aimed to pharmacologically treat stroke, a prominent cause of death, disability, and dementia, have remained elusive. A promising approach is restriction of excitotoxic neuronal death in the infarct penumbra through enhancement of survival pathways initiated by brain-derived neurotrophic factor (BDNF). However, boosting of neurotrophic signaling after ischemia is challenged by downregulation of BDNF high-affinity receptor, full-length tropomyosin-related kinase B (TrkB-FL), due to calpain-degradation, and, secondarily, regulated intramembrane proteolysis. Here, we have designed a blood-brain barrier (BBB) permeable peptide containing TrkB-FL sequences (TFL457 ) which prevents receptor disappearance from the neuronal surface, early induced after excitotoxicity. In this way, TFL457 interferes TrkB-FL cleavage by both proteolytic systems and increases neuronal viability via a PLCγ-dependent mechanism. By preserving downstream CREB and MEF2 promoter activities, TFL457 initiates a feedback mechanism favoring increased levels in excitotoxic neurons of critical prosurvival mRNAs and proteins. This neuroprotective peptide could be highly relevant for stroke therapy since, in a mouse ischemia model, it counteracts TrkB-FL downregulation in the infarcted brain, efficiently decreases infarct size, and improves neurological outcome.
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Affiliation(s)
- Gonzalo S Tejeda
- Instituto de Investigaciones Biomédicas “Alberto Sols”Consejo Superior de Investigaciones Científicas‐Universidad Autónoma de Madrid (CSIC‐UAM)MadridSpain
- Present address:
Gardiner LaboratoryInstitute of Cardiovascular and Medical SciencesCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Gema M Esteban‐Ortega
- Instituto de Investigaciones Biomédicas “Alberto Sols”Consejo Superior de Investigaciones Científicas‐Universidad Autónoma de Madrid (CSIC‐UAM)MadridSpain
| | - Esther San Antonio
- Instituto de Investigaciones Biomédicas “Alberto Sols”Consejo Superior de Investigaciones Científicas‐Universidad Autónoma de Madrid (CSIC‐UAM)MadridSpain
| | - Óscar G Vidaurre
- Instituto de Investigaciones Biomédicas “Alberto Sols”Consejo Superior de Investigaciones Científicas‐Universidad Autónoma de Madrid (CSIC‐UAM)MadridSpain
| | - Margarita Díaz‐Guerra
- Instituto de Investigaciones Biomédicas “Alberto Sols”Consejo Superior de Investigaciones Científicas‐Universidad Autónoma de Madrid (CSIC‐UAM)MadridSpain
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14
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Rogers JP, Pollak TA, Blackman G, David AS. Catatonia and the immune system: a review. Lancet Psychiatry 2019; 6:620-630. [PMID: 31196793 PMCID: PMC7185541 DOI: 10.1016/s2215-0366(19)30190-7] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 03/27/2019] [Accepted: 04/04/2019] [Indexed: 12/13/2022]
Abstract
Catatonia is a psychomotor disorder featuring stupor, posturing, and echophenomena. This Series paper examines the evidence for immune dysregulation in catatonia. Activation of the innate immune system is associated with mutism, withdrawal, and psychomotor retardation, which constitute the neurovegetative features of catatonia. Evidence is sparse and conflicting for acute-phase activation in catatonia, and whether this feature is secondary to immobility is unclear. Various viral, bacterial, and parasitic infections have been associated with catatonia, but it is primarily linked to CNS infections. The most common cause of autoimmune catatonia is N-methyl-D-aspartate receptor (NMDAR) encephalitis, which can account for the full spectrum of catatonic features. Autoimmunity appears to cause catatonia less by systemic inflammation than by the downstream effects of specific actions on extracellular antigens. The specific association with NMDAR encephalitis supports a hypothesis of glutamatergic hypofunction in catatonia.
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Affiliation(s)
- Jonathan P Rogers
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; South London and Maudsley National Health Service Foundation Trust, Bethlem Royal Hospital, UK.
| | - Thomas A Pollak
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; South London and Maudsley National Health Service Foundation Trust, Bethlem Royal Hospital, UK
| | - Graham Blackman
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; South London and Maudsley National Health Service Foundation Trust, Bethlem Royal Hospital, UK
| | - Anthony S David
- Institute of Mental Health, University College London, London, UK
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15
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Todd L, Palazzo I, Suarez L, Liu X, Volkov L, Hoang TV, Campbell WA, Blackshaw S, Quan N, Fischer AJ. Reactive microglia and IL1β/IL-1R1-signaling mediate neuroprotection in excitotoxin-damaged mouse retina. J Neuroinflammation 2019; 16:118. [PMID: 31170999 PMCID: PMC6555727 DOI: 10.1186/s12974-019-1505-5] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/09/2019] [Indexed: 12/12/2022] Open
Abstract
Background Microglia and inflammation have context-specific impacts upon neuronal survival in different models of central nervous system (CNS) disease. Herein, we investigate how inflammatory mediators, including microglia, interleukin 1 beta (IL1β), and signaling through interleukin 1 receptor type 1 (IL-1R1), influence the survival of retinal neurons in response to excitotoxic damage. Methods Excitotoxic retinal damage was induced via intraocular injections of NMDA. Microglial phenotype and neuronal survival were assessed by immunohistochemistry. Single-cell RNA sequencing was performed to obtain transcriptomic profiles. Microglia were ablated by using clodronate liposome or PLX5622. Retinas were treated with IL1β prior to NMDA damage and cell death was assessed in wild type, IL-1R1 null mice, and mice expressing IL-1R1 only in astrocytes. Results NMDA-induced damage included neuronal cell death, microglial reactivity, upregulation of pro-inflammatory cytokines, and genes associated with IL1β-signaling in different types of retinal neurons and glia. Expression of the IL1β receptor, IL-1R1, was evident in astrocytes, endothelial cells, some Müller glia, and OFF bipolar cells. Ablation of microglia with clodronate liposomes or Csf1r antagonist (PLX5622) resulted in elevated cell death and diminished neuronal survival in excitotoxin-damaged retinas. Exogenous IL1β stimulated the proliferation and reactivity of microglia in the absence of damage, reduced numbers of dying cells in damaged retinas, and increased neuronal survival following an insult. IL1β failed to provide neuroprotection in the IL-1R1-null retina, but IL1β-mediated neuroprotection was rescued when expression of IL-1R1 was restored in astrocytes. Conclusions We conclude that reactive microglia provide protection to retinal neurons, since the absence of microglia is detrimental to survival. We propose that, at least in part, the survival-influencing effects of microglia may be mediated by IL1β, IL-1R1, and interactions of microglia and other macroglia. Electronic supplementary material The online version of this article (10.1186/s12974-019-1505-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Levi Todd
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Isabella Palazzo
- Department of Neuroscience, College of Medicine, The Ohio State University, 3020 Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210-1239, USA
| | - Lilianna Suarez
- Department of Neuroscience, College of Medicine, The Ohio State University, 3020 Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210-1239, USA
| | - Xiaoyu Liu
- Institute for Behavioral Medicine Research, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Leo Volkov
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Thanh V Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Warren A Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, 3020 Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210-1239, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ning Quan
- Institute for Behavioral Medicine Research, College of Medicine, The Ohio State University, Columbus, OH, USA.,Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, 3020 Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210-1239, USA.
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16
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Jiang S, Li T, Ji T, Yi W, Yang Z, Wang S, Yang Y, Gu C. AMPK: Potential Therapeutic Target for Ischemic Stroke. Am J Cancer Res 2018; 8:4535-4551. [PMID: 30214637 PMCID: PMC6134933 DOI: 10.7150/thno.25674] [Citation(s) in RCA: 162] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 07/16/2018] [Indexed: 02/07/2023] Open
Abstract
5'-AMP-activated protein kinase (AMPK), a member of the serine/threonine (Ser/Thr) kinase group, is universally distributed in various cells and organs. It is a significant endogenous defensive molecule that responds to harmful stimuli, such as cerebral ischemia, cerebral hemorrhage, and, neurodegenerative diseases (NDD). Cerebral ischemia, which results from insufficient blood flow or the blockage of blood vessels, is a major cause of ischemic stroke. Ischemic stroke has received increased attention due to its '3H' effects, namely high mortality, high morbidity, and high disability. Numerous studies have revealed that activation of AMPK plays a protective role in the brain, whereas its action in ischemic stroke remains elusive and poorly understood. Based on existing evidence, we introduce the basic structure, upstream regulators, and biological roles of AMPK. Second, we analyze the relationship between AMPK and the neurovascular unit (NVU). Third, the actions of AMPK in different phases of ischemia and current therapeutic methods are discussed. Finally, we evaluate existing controversy and provide a detailed analysis, followed by ethical issues, potential directions, and further prospects of AMPK. The information complied here may aid in clinical and basic research of AMPK, which may be a potent drug candidate for ischemic stroke treatment in the future.
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17
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Lieberman AP, Shakkottai VG, Albin RL. Polyglutamine Repeats in Neurodegenerative Diseases. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2018; 14:1-27. [PMID: 30089230 DOI: 10.1146/annurev-pathmechdis-012418-012857] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Among the age-dependent protein aggregation disorders, nine neurodegenerative diseases are caused by expansions of CAG repeats encoding polyglutamine (polyQ) tracts. We review the clinical, pathological, and biological features of these inherited disorders. We discuss insights into pathogenesis gleaned from studies of model systems and patients, highlighting work that informs efforts to develop effective therapies. An important conclusion from these analyses is that expanded CAG/polyQ domains are the primary drivers of neurodegeneration, with the biology of carrier proteins influencing disease-specific manifestations. Additionally, it has become apparent that CAG/polyQ repeat expansions produce neurodegeneration via multiple downstream mechanisms, involving both gain- and loss-of-function effects. This conclusion indicates that the likelihood of developing effective therapies targeting single nodes is reduced. The evaluation of treatments for premanifest disease will likely require new investigational approaches. We highlight the opportunities and challenges underlying ongoing work and provide recommendations related to the development of symptomatic and disease-modifying therapies and biomarkers that could inform future research.
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Affiliation(s)
- Andrew P Lieberman
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA;
| | - Vikram G Shakkottai
- Department of Neurology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA; , .,Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - Roger L Albin
- Department of Neurology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA; , .,Neurology Service and the Geriatric Research, Education, and Clinical Center (GRECC), VA Ann Arbor Healthcare System, Ann Arbor, Michigan 48105, USA
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18
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Amin JB, Wollmuth LP. A Swiss army knife for targeting receptors. eLife 2018; 7:e37413. [PMID: 29792596 PMCID: PMC5967861 DOI: 10.7554/elife.37413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 11/20/2022] Open
Abstract
A compound can change the activity of NMDA receptors in some regions of a synapse without affecting those in other regions.
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Affiliation(s)
- Johansen B Amin
- Program in Cellular and Molecular BiologyStony Brook UniversityStony BrookUnited States
- Medical Scientist Training Program (MSTP)Stony Brook UniversityStony BrookUnited States
| | - Lonnie P Wollmuth
- Center for Nervous Systems DisordersStony Brook UniversityStony BrookUnited States
- Department of Neurobiology and BehaviorStony Brook UniversityStony BrookUnited States
- Department of Biochemistry and Cell BiologyStony Brook UniversityStony BrookUnited States
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19
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The Midline Axon Crossing Decision Is Regulated through an Activity-Dependent Mechanism by the NMDA Receptor. eNeuro 2018; 5:eN-NWR-0389-17. [PMID: 29766040 PMCID: PMC5952305 DOI: 10.1523/eneuro.0389-17.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 03/03/2018] [Accepted: 03/28/2018] [Indexed: 02/06/2023] Open
Abstract
Axon guidance in vertebrates is controlled by genetic cascades as well as by intrinsic activity-dependent refinement of connections. Midline axon crossing is one of the best studied pathfinding models and is fundamental to the establishment of bilaterally symmetric nervous systems. However, it is not known whether crossing requires intrinsic activity in axons, and what controls that activity. Further, a mechanism linking neuronal activity and gene expression has not been identified for axon pathfinding. Using embryonic zebrafish, we found that the NMDA receptor (NMDAR) NR1.1 subunit (grin1a) is expressed in commissural axons. Pharmacological inhibition of grin1a, hypoxia exposure reduction of grin1a expression, or CRISPR knock-down of grin1a leads to defects in midline crossing. Inhibition of neuronal activity phenocopies the effects of grin1a loss on midline crossing. By combining pharmacological inhibition of the NMDAR with optogenetic stimulation to precisely restore neuronal activity, we observed rescue of midline crossing. This suggests that the NMDAR controls pathfinding by an activity-dependent mechanism. We further show that the NMDAR may act, via modulating activity, on the transcription factor arxa (mammalian Arx), a known regulator of midline pathfinding. These findings uncover a novel role for the NMDAR in controlling activity to regulate commissural pathfinding and identify arxa as a key link between the genetic and activity-dependent regulation of midline axon guidance.
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20
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Marballi KK, Gallitano AL. Immediate Early Genes Anchor a Biological Pathway of Proteins Required for Memory Formation, Long-Term Depression and Risk for Schizophrenia. Front Behav Neurosci 2018; 12:23. [PMID: 29520222 PMCID: PMC5827560 DOI: 10.3389/fnbeh.2018.00023] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 01/29/2018] [Indexed: 01/02/2023] Open
Abstract
While the causes of myriad medical and infectious illnesses have been identified, the etiologies of neuropsychiatric illnesses remain elusive. This is due to two major obstacles. First, the risk for neuropsychiatric disorders, such as schizophrenia, is determined by both genetic and environmental factors. Second, numerous genes influence susceptibility for these illnesses. Genome-wide association studies have identified at least 108 genomic loci for schizophrenia, and more are expected to be published shortly. In addition, numerous biological processes contribute to the neuropathology underlying schizophrenia. These include immune dysfunction, synaptic and myelination deficits, vascular abnormalities, growth factor disruption, and N-methyl-D-aspartate receptor (NMDAR) hypofunction. However, the field of psychiatric genetics lacks a unifying model to explain how environment may interact with numerous genes to influence these various biological processes and cause schizophrenia. Here we describe a biological cascade of proteins that are activated in response to environmental stimuli such as stress, a schizophrenia risk factor. The central proteins in this pathway are critical mediators of memory formation and a particular form of hippocampal synaptic plasticity, long-term depression (LTD). Each of these proteins is also implicated in schizophrenia risk. In fact, the pathway includes four genes that map to the 108 loci associated with schizophrenia: GRIN2A, nuclear factor of activated T-cells (NFATc3), early growth response 1 (EGR1) and NGFI-A Binding Protein 2 (NAB2); each of which contains the "Index single nucleotide polymorphism (SNP)" (most SNP) at its respective locus. Environmental stimuli activate this biological pathway in neurons, resulting in induction of EGR immediate early genes: EGR1, EGR3 and NAB2. We hypothesize that dysfunction in any of the genes in this pathway disrupts the normal activation of Egrs in response to stress. This may result in insufficient electrophysiologic, immunologic, and neuroprotective, processes that these genes normally mediate. Continued adverse environmental experiences, over time, may thereby result in neuropathology that gives rise to the symptoms of schizophrenia. By combining multiple genes associated with schizophrenia susceptibility, in a functional cascade triggered by neuronal activity, the proposed biological pathway provides an explanation for both the polygenic and environmental influences that determine the complex etiology of this mental illness.
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Affiliation(s)
- Ketan K. Marballi
- Department of Basic Medical Sciences and Psychiatry, University of Arizona College of Medicine—Phoenix, Phoenix, AZ, United States
| | - Amelia L. Gallitano
- Department of Basic Medical Sciences and Psychiatry, University of Arizona College of Medicine—Phoenix, Phoenix, AZ, United States
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21
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Li T, Wang L, Hu Q, Liu S, Bai X, Xie Y, Zhang T, Bo S, Gao X, Wu S, Li G, Wang Z. Neuroprotective Roles of l-Cysteine in Attenuating Early Brain Injury and Improving Synaptic Density via the CBS/H 2S Pathway Following Subarachnoid Hemorrhage in Rats. Front Neurol 2017; 8:176. [PMID: 28512446 PMCID: PMC5411453 DOI: 10.3389/fneur.2017.00176] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 04/13/2017] [Indexed: 01/31/2023] Open
Abstract
l-Cysteine is a semi-essential amino acid and substrate for cystathionine-β-synthase (CBS) in the central nervous system. We previously reported that NaHS, an H2S donor, significantly alleviated brain damage after subarachnoid hemorrhage (SAH) in rats. However, the potential therapeutic value of l-cysteine and the molecular mechanism supporting these beneficial effects have not been determined. This study was designed to investigate whether l-cysteine could attenuate early brain injury following SAH and improve synaptic function by releasing endogenous H2S. Male Wistar rats were subjected to SAH induced by cisterna magna blood injection, and l-cysteine was intracerebroventricularly administered 30 min after SAH induction. Treatment with l-cysteine stimulated CBS activity in the prefrontal cortex (PFC) and H2S production. Moreover, l-cysteine treatment significantly ameliorated brain edema, improved neurobehavioral function, and attenuated neuronal cell death in the PFC; these effects were associated with a decrease in the Bax/Bcl-2 ratio and the suppression of caspase-3 activation 48 h after SAH. Furthermore, l-cysteine treatment activated the CREB-brain-derived neurotrophic factor (BDNF) pathway and intensified synaptic density by regulating synapse proteins 48 h after SAH. Importantly, all the beneficial effects of l-cysteine in SAH were abrogated by amino-oxyacetic acid, a CBS inhibitor. Based on these findings, l-cysteine may play a neuroprotective role in SAH by inhibiting cell apoptosis, upregulating CREB-BDNF expression, and promoting synaptic structure via the CBS/H2S pathway.
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Affiliation(s)
- Tong Li
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, Jinan, China.,Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Lingxiao Wang
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, Jinan, China.,Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Quan Hu
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, Jinan, China.,Department of Neurosurgery, Taian Central Hospital, Taian, China
| | - Song Liu
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Xuemei Bai
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Yunkai Xie
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Tiantian Zhang
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Shishi Bo
- Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Xiangqian Gao
- Department of Pathology, Binzhou Medical University Hospital, Binzhou, China
| | - Shuhua Wu
- Department of Pathology, Binzhou Medical University Hospital, Binzhou, China
| | - Gang Li
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, Jinan, China
| | - Zhen Wang
- Department of Physiology, Shandong University School of Medicine, Jinan, China
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22
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Wang L, Wang A, Supplee WW, Koffler K, Cheng Y, Quezado ZMN, Levy RJ. Carbon monoxide incompletely prevents isoflurane-induced defects in murine neurodevelopment. Neurotoxicol Teratol 2017; 61:92-103. [PMID: 28131877 DOI: 10.1016/j.ntt.2017.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 01/17/2017] [Accepted: 01/24/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND Commonly used anesthetics have been shown to disrupt neurodevelopment in preclinical models. It has been proposed that such anesthesia-induced neurotoxicity is mediated by apoptotic neurodegeneration in the immature brain. Low dose carbon monoxide (CO) exerts cytoprotective properties and we have previously demonstrated that CO inhibits isoflurane-induced apoptosis in the developing murine brain. Here we utilized anti-apoptotic concentrations of CO to delineate the role of apoptotic neurodegeneration in anesthesia-induced neurotoxicity by assessing the effect of CO on isoflurane-induced defects in neurodevelopment. METHODS C57Bl/6 mouse pups underwent 1-hour exposure to 0ppm (air), 5ppm, or 100ppm CO in air with or without isoflurane on postnatal day 7. Cohorts were evaluated 5-7weeks post exposure with T-maze cognitive testing followed by social behavior assessment. Brain size, whole brain cellular content, and neuronal density in primary somatosensory cortex and hippocampal CA3 region were measured as secondary outcomes 1-week or 5-7weeks post exposure along with 7-day old, unexposed controls. RESULTS Isoflurane impaired memory acquisition and resulted in abnormal social behavior. Low concentration CO abrogated anesthetic-induced defects in memory acquisition, however, it also resulted in impaired spatial reference memory and social behavior abnormalities. Changes in brain size, cellular content, and neuronal density over time related to the age of the animal and were unaffected by either isoflurane or CO. CONCLUSIONS Anti-apoptotic concentrations of CO incompletely prevented isoflurane-induced defects in neurodevelopment, lacked concentration-dependent effects, and only provided protection in certain domains suggesting that anesthesia-related neurotoxicity is not solely mediated by activation of the mitochondrial apoptosis pathway.
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Affiliation(s)
- Li Wang
- The Sheikh Zayed Institute for Pediatric Surgical Innovation, Division of Pain Medicine, Children's National Health System, Children's Research Institute, The George Washington University School of Medicine and Health Sciences, United States
| | - Aili Wang
- Department of Anesthesiology, Columbia University Medical Center, United States
| | | | - Kayla Koffler
- Department of Anesthesiology, Columbia University Medical Center, United States
| | - Ying Cheng
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, The George Washington University School of Medicine and Health Sciences, United States
| | - Zenaide M N Quezado
- The Sheikh Zayed Institute for Pediatric Surgical Innovation, Division of Pain Medicine, Children's National Health System, Children's Research Institute, The George Washington University School of Medicine and Health Sciences, United States
| | - Richard J Levy
- Department of Anesthesiology, Columbia University Medical Center, United States.
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23
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Chan SY, Matthews E, Burnet PWJ. ON or OFF?: Modulating the N-Methyl-D-Aspartate Receptor in Major Depression. Front Mol Neurosci 2017; 9:169. [PMID: 28133445 PMCID: PMC5233677 DOI: 10.3389/fnmol.2016.00169] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/27/2016] [Indexed: 12/20/2022] Open
Abstract
Since the discovery that a single dose of ketamine, an N-methyl-D-aspartate receptor (NMDAR) antagonist, had rapid and long-lasting antidepressant effects, there has been increased interest in using NMDAR modulators in the pharmacotherapy of depression. Ketamine's efficacy seems to imply that depression is a disorder of NMDAR hyperfunctionality. However, studies showing that not all NMDAR antagonists are able to act as antidepressants challenge this notion. Furthermore, NMDAR co-agonists have also been gaining attention as possible treatments. Co-agonists such as D-serine and sarcosine have shown efficacy in both pre-clinical models and human trials. This raises the question of how both NMDAR antagonists and agonists are able to have converging behavioral effects. Here we critically review the evidence and proposed therapeutic mechanisms for both NMDAR antagonists and agonists, and collate several theories on how both activation and inhibition of NMDARs appear to have antidepressant effects.
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Affiliation(s)
- Shi Yu Chan
- Department of Psychiatry, Warneford Hospital, University of Oxford Oxford, UK
| | | | - Philip W J Burnet
- Department of Psychiatry, Warneford Hospital, University of Oxford Oxford, UK
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24
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Levy RJ. Carbon monoxide and anesthesia-induced neurotoxicity. Neurotoxicol Teratol 2016; 60:50-58. [PMID: 27616667 DOI: 10.1016/j.ntt.2016.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 08/10/2016] [Accepted: 09/06/2016] [Indexed: 10/21/2022]
Abstract
The majority of commonly used anesthetic agents induce widespread neuronal degeneration in the developing mammalian brain. Downstream, the process appears to involve activation of the oxidative stress-associated mitochondrial apoptosis pathway. Targeting this pathway could result in prevention of anesthetic toxicity in the immature brain. Carbon monoxide (CO) is a gas that exerts biological activity in the developing brain and low dose exposures have the potential to provide neuroprotection. In recent work, low concentration CO exposures limited isoflurane-induced neuronal apoptosis in a dose-dependent manner in newborn mice and modulated oxidative stress within forebrain mitochondria. Because infants and children are routinely exposed to low levels of CO during low-flow general endotracheal anesthesia, such anti-oxidant and pro-survival cellular effects are clinically relevant. Here we provide an overview of anesthesia-related CO exposure, discuss the biological activity of low concentration CO, detail the effects of CO in the brain during development, and provide evidence for CO-mediated inhibition of anesthesia-induced neurotoxicity.
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Affiliation(s)
- Richard J Levy
- Department of Anesthesiology, Columbia University Medical Center, United States.
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25
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Li T, Liu H, Xue H, Zhang J, Han X, Yan S, Bo S, Liu S, Yuan L, Deng L, Li G, Wang Z. Neuroprotective Effects of Hydrogen Sulfide Against Early Brain Injury and Secondary Cognitive Deficits Following Subarachnoid Hemorrhage. Brain Pathol 2016; 27:51-63. [PMID: 26822402 DOI: 10.1111/bpa.12361] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 01/24/2016] [Indexed: 01/17/2023] Open
Abstract
Although the neuroprotective effects of hydrogen sulfide (H2 S) have been demonstrated in several studies, whether H2 S protects against early brain injury (EBI) and secondary cognitive dysfunction in subarachnoid hemorrhage (SAH) model remains unknown. This study was undertaken to evaluate the influence of H2 S on both acute brain injury and neurobehavioral changes as well as the underlying mechanisms after SAH. The H2 S donor, NaHS, was administered via an intraperitoneal injection at a dose of 5.6 mg/kg at 2 h, 6 h, 24 h, and 46 h after SAH in rat model. The results showed that NaHS treatment significantly improved brain edema and neurobehavioral function, and attenuated neuronal cell death in the prefrontal cortex, associated with a decrease in Bax/Bcl-2 ratio and suppression of caspase-3 activation at 48 h after SAH. NaHS also promoted phospho-Akt and phospho-ERK levels. Furthermore, NaHS treatment significantly enhanced the levels of brain-derived neurotrophic factor (BDNF) and phospho-CREB. Importantly, NaHS administration improved learning and memory performance in the Morris water maze test at 7 days post-SAH in rats. These results demonstrated that NaHS, as an exogenous H2 S donor, could significantly alleviate the development of EBI and cognitive dysfunction induced by SAH via Akt/ERK-related antiapoptosis pathway, and upregulating BDNF-CREB expression.
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Affiliation(s)
- Tong Li
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, 107#, Wenhua Xi Road, Jinan, Shandong Province, 250012, P.R. China.,Department of Physiology, Shandong University School of Medicine, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, P.R. China
| | - Hansen Liu
- Department of Physiology, Shandong University School of Medicine, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, P.R. China
| | - Hao Xue
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, 107#, Wenhua Xi Road, Jinan, Shandong Province, 250012, P.R. China
| | - Jinsen Zhang
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, 107#, Wenhua Xi Road, Jinan, Shandong Province, 250012, P.R. China
| | - Xiao Han
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, 107#, Wenhua Xi Road, Jinan, Shandong Province, 250012, P.R. China
| | - Shaofeng Yan
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, 107#, Wenhua Xi Road, Jinan, Shandong Province, 250012, P.R. China
| | - Shishi Bo
- Department of Physiology, Shandong University School of Medicine, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, P.R. China
| | - Song Liu
- Department of Physiology, Shandong University School of Medicine, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, P.R. China
| | - Lin Yuan
- Department of Physiology, Shandong University School of Medicine, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, P.R. China
| | - Lin Deng
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, 107#, Wenhua Xi Road, Jinan, Shandong Province, 250012, P.R. China
| | - Gang Li
- Department of Neurosurgery, Qilu Hospital of Shandong University and Brain Science Research Institute, Shandong University, 107#, Wenhua Xi Road, Jinan, Shandong Province, 250012, P.R. China
| | - Zhen Wang
- Department of Physiology, Shandong University School of Medicine, 44#, Wenhua Xi Road, Jinan, Shandong, 250012, P.R. China
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Xia C, Shen S, Hashmi F, Qiao LY. Colitis-induced bladder afferent neuronal activation is regulated by BDNF through PLCγ pathway. Exp Neurol 2015; 285:126-135. [PMID: 26687970 DOI: 10.1016/j.expneurol.2015.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 11/14/2015] [Accepted: 12/10/2015] [Indexed: 02/08/2023]
Abstract
Patients with inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS) often experience increased sensory responsiveness in the urinary bladder reflecting neurogenic bladder overactivity. Here we demonstrate that colitis-induced up-regulation of the phospholipase C gamma (PLCγ) pathway downstream of brain-derived neurotrophic factor (BDNF) in bladder afferent neurons in the dorsal root ganglia (DRG) plays essential roles in activating these neurons thereby leading to bladder hyperactivity. Upon induction of colitis with 2,4,6-trinitrobenzenesulfonic acid (TNBS) in rats, we found that the phosphorylation (activation) level of cAMP responsive element-binding (p-CREB) protein, a molecular switch of neuronal plasticity, was increased in specifically labeled bladder afferent neurons in the thoracolumbar and lumbosacral DRGs. In rats having reduced levels of BDNF (BDNF+/-), colitis failed to elevate CREB protein activity in bladder afferent neurons. Physiological examination also demonstrated that colitis-induced urinary frequency was not shown in BDNF+/- rats, implicating an essential role of BDNF in mediating colon-to-bladder sensory cross-sensitization. We further implemented in vivo and in vitro studies and demonstrated that BDNF-mediated colon-to-bladder sensory cross-activation involved the TrkB-PLCγ-calcium/calmodulin-dependent protein kinase II (CaMKII) cascade. In contrast, the PI3K/Akt pathway was not activated in bladder afferent neurons during colitis and was not involved in BDNF action in the DRG. Our results suggest that colon-to-bladder sensory cross-sensitization is regulated by specific signal transduction initiated by the up-regulation of BDNF in the DRG.
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Affiliation(s)
- Chunmei Xia
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Shanwei Shen
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Fiza Hashmi
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Li-Ya Qiao
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA.
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Dean BJF, Snelling SJB, Dakin SG, Javaid MK, Carr AJ. In vitro effects of glutamate and N-methyl-D-aspartate receptor (NMDAR) antagonism on human tendon derived cells. J Orthop Res 2015; 33:1515-22. [PMID: 26041147 DOI: 10.1002/jor.22923] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/07/2015] [Indexed: 02/04/2023]
Abstract
It is known that extracellular glutamate concentrations are increased in tendinopathy but the effects of glutamate upon human tendon derived cells are unknown. The primary purpose was to investigate the effect of glutamate exposure on human tendon-derived cells in terms of viability, protein, and gene expression. The second purpose was to assess whether NMDAR antagonism would affect the response of tendon-derived cells to glutamate exposure. Human tendon-derived cells were obtained from supraspinatus tendon tissue obtained during rotator cuff repair (tendon tear derived cells) and from healthy hamstring tendon tissue (control cells). The in vitro impact of glutamate exposure and NMDAR antagonism (MK-801) was measured using the Alamar blue cell viability assay, immunocytochemistry, and quantitative real-time PCR. Glutamate reduced cell viability at 24 h in tendon tear derived cells but not in control cells at concentrations of 7.5 mM and above. Cell viability was significantly reduced after 72 h of 1.875 mM glutamate in both cell groups; this deleterious effect was attenuated by NMDAR antagonism with 10 µM MK-801. Both 24 and 72 h of 1.875 mM glutamate exposure reduced Type 1 alpha 1 collagen (COL1A1) and Type 3 alpha 1 collagen (COL3A1) gene expression, but increased Aggrecan gene expression. We propose that these effects of glutamate on tendon derived cells including reduced cell viability and altered matrix gene expression contribute to the pathogenesis of tendinopathy.
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Affiliation(s)
- Benjamin John Floyd Dean
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, United Kingdom
| | - Sarah J B Snelling
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, United Kingdom
| | - Stephanie Georgina Dakin
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, United Kingdom
| | - Muhammad Kassim Javaid
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, United Kingdom
| | - Andrew Jonathan Carr
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, United Kingdom
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Dai HB, Xu MM, Lv J, Ji XJ, Zhu SH, Ma RM, Miao XL, Duan ML. Mild Hypothermia Combined with Hydrogen Sulfide Treatment During Resuscitation Reduces Hippocampal Neuron Apoptosis Via NR2A, NR2B, and PI3K-Akt Signaling in a Rat Model of Cerebral Ischemia-Reperfusion Injury. Mol Neurobiol 2015; 53:4865-73. [DOI: 10.1007/s12035-015-9391-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 08/11/2015] [Indexed: 10/23/2022]
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Dai HB, Ji X, Zhu SH, Hu YM, Zhang LD, Miao XL, Ma RM, Duan ML, Li WY. Hydrogen sulphide and mild hypothermia activate the CREB signaling pathway and prevent ischemia-reperfusion injury. BMC Anesthesiol 2015; 15:119. [PMID: 26283659 PMCID: PMC4538757 DOI: 10.1186/s12871-015-0097-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 07/22/2015] [Indexed: 01/23/2023] Open
Abstract
Background Both hydrogen sulphide (H2S) and mild hypothermia have been reported to prevent brain damage caused by reperfusion assault through regulating the N-methyl-D-aspartate receptor (NMDAR). However, the relationship between the two treatments and how they exert neuro-protective effects through NMDARs remain to be elucidated. Methods Transient cerebral ischemia was induced using the Pulsinelli four-vessel occlusion method. We used sodium hydrosulphide (NaHS) as the H2S donor. We randomly divided 100 Sprague–Dawley rats into five groups of 20: Sham operation group (Sh), normothermic (36-37 °C) ischemia group (NT), mild hypothermic (32-33 °C) ischemia group (mHT), normothermic ischemia combined with NaHS treatment group (NT + NaHS), and mild hypothermic ischemia combined with NaHS treatment group (mHT + NaHS). After 6 hrs of reperfusion, rats were decapitated and hippocampus samples were immediately collected. We measured NR2A (GluN1), NR2B (GluN2) and p-CREB protein levels using western blotting. We further analyzed BDNF mRNA expression by real-time PCR. Hematoxylin and eosin (HE) staining was used to examine pyramidal cell histology at the CA1 region. All statistical analyses were carried out by ANOVA and LSD t-test as implemented by the SPSS 13.0 software. Results In the four test groups with ischemia-reperfusion, hippocampal H2S concentration increased following treatment, and administration of NaHS further increased H2S levels. Moreover, administration of both NaHS and mild hypothermia resulted in up-regulation of NR2A and NR2B protein expressions, as well as p-CREB protein and BDNF mRNA levels. At the cellular level, NaHS and mild hypothermia groups exhibited lower damage caused by ischemia-reperfusion in the CA1 region of the hippocampus. The strongest protective effect was observed in rats treated with combined NaHS and mild hypothermia, suggesting their effects were additive. Conclusion Our results support previous findings that hydrogen sulphide and mild hypothermia can prevent ischemia-reperfusion injury. Both treatments caused an up-regulation of NMDA receptors, as well as an elevation in p-CREB protein and BDNF mRNA levels. Thus, hydrogen sulphide and mild hypothermia may provide neuro-protective effect through activating the pro-survival CREB signaling pathway.
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Affiliation(s)
- Hai-bin Dai
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, No. 305 East Zhongshan Road, Jiangsu, Nanjing, 210002, China.
| | - Xiangjun Ji
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, No. 305 East Zhongshan Road, Jiangsu, Nanjing, 210002, China.
| | - Si-hai Zhu
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, No. 305 East Zhongshan Road, Jiangsu, Nanjing, 210002, China.
| | - Yi-min Hu
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, No. 305 East Zhongshan Road, Jiangsu, Nanjing, 210002, China.
| | - Li-dong Zhang
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, No. 305 East Zhongshan Road, Jiangsu, Nanjing, 210002, China.
| | - Xiao-lei Miao
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, No. 305 East Zhongshan Road, Jiangsu, Nanjing, 210002, China.
| | - Ru-Meng Ma
- Department of Experimental Surgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.
| | - Man-lin Duan
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, No. 305 East Zhongshan Road, Jiangsu, Nanjing, 210002, China.
| | - Wei-yan Li
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, No. 305 East Zhongshan Road, Jiangsu, Nanjing, 210002, China.
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Dean BJF, Snelling SJB, Dakin SG, Murphy RJ, Javaid MK, Carr AJ. Differences in glutamate receptors and inflammatory cell numbers are associated with the resolution of pain in human rotator cuff tendinopathy. Arthritis Res Ther 2015; 17:176. [PMID: 26160609 PMCID: PMC4498529 DOI: 10.1186/s13075-015-0691-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Accepted: 06/18/2015] [Indexed: 12/18/2022] Open
Abstract
INTRODUCTION The relationship between peripheral tissue characteristics and pain symptoms in soft tissue inflammation is poorly understood. The primary aim of this study was to determine immunohistochemical differences in tissue obtained from patients with persistent pain and patients who had become pain-free after surgical treatment for rotator cuff tendinopathy. The secondary aim was to investigate whether there would be differences in glutaminergic and inflammatory gene expression between disease-derived and healthy control cells in vitro. METHODS Supraspinatus tendon biopsies were obtained from nine patients with tendon pain before shoulder surgery and from nine further patients whose pain had resolved completely following shoulder surgery. Histological markers relating to the basic tendon characteristics, inflammation and glutaminergic signalling were quantified by immunohistochemical analysis. Gene expression of glutaminergic and inflammatory markers was determined in tenocyte explants derived from painful rotator cuff tendon tears in a separate cohort of patients and compared to that of explants from healthy control tendons. Dual labelling was performed to identify cell types expressing nociceptive neuromodulators. RESULTS Tendon samples from patients with persistent pain demonstrated increased levels of metabotropic glutamate receptor 2 (mGluR2), kainate receptor 1 (KA1), protein gene product 9.5 (PGP9.5), CD206 (macrophage marker) and CD45 (pan-leucocyte marker) versus pain-free controls (p <0.05). NMDAR1 co-localised with CD206-positive cells, whereas PGP9.5 and glutamate were predominantly expressed by resident tendon cells. These results were validated by in vitro increases in the expression of mGluR2, N-methyl-D-aspartate receptor (NMDAR1), KA1, CD45, CD206 and tumour necrosis factor alpha (TNF-α) genes (p <0.05) in disease-derived versus control cells. CONCLUSIONS We conclude that differences in glutamate receptors and inflammatory cell numbers are associated with the resolution of shoulder pain in rotator cuff tendinopathy, and that disease-derived cells exhibit a distinctly different neuro-inflammatory gene expression profile to healthy control cells.
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Affiliation(s)
- Benjamin John Floyd Dean
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, UK.
| | - Sarah J B Snelling
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, UK.
| | - Stephanie G Dakin
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, UK.
| | - Richard J Murphy
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, UK.
| | - Muhammad Kassim Javaid
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, UK.
| | - Andrew Jonathan Carr
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford, OX3 7LD, UK.
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Kantamneni S. Cross-talk and regulation between glutamate and GABAB receptors. Front Cell Neurosci 2015; 9:135. [PMID: 25914625 PMCID: PMC4392697 DOI: 10.3389/fncel.2015.00135] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 03/23/2015] [Indexed: 12/16/2022] Open
Abstract
Brain function depends on co-ordinated transmission of signals from both excitatory and inhibitory neurotransmitters acting upon target neurons. NMDA, AMPA and mGluR receptors are the major subclasses of glutamate receptors that are involved in excitatory transmission at synapses, mechanisms of activity dependent synaptic plasticity, brain development and many neurological diseases. In addition to canonical role of regulating presynaptic release and activating postsynaptic potassium channels, GABAB receptors also regulate glutamate receptors. There is increasing evidence that metabotropic GABAB receptors are now known to play an important role in modulating the excitability of circuits throughout the brain by directly influencing different types of postsynaptic glutamate receptors. Specifically, GABAB receptors affect the expression, activity and signaling of glutamate receptors under physiological and pathological conditions. Conversely, NMDA receptor activity differentially regulates GABAB receptor subunit expression, signaling and function. In this review I will describe how GABAB receptor activity influence glutamate receptor function and vice versa. Such a modulation has widespread implications for the control of neurotransmission, calcium-dependent neuronal function, pain pathways and in various psychiatric and neurodegenerative diseases.
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Affiliation(s)
- Sriharsha Kantamneni
- Bradford School of Pharmacy, School of Life Sciences, University of Bradford Bradford, West Yorkshire, UK
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32
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Manza P, Zhang S, Hu S, Chao HH, Leung HC, Li CSR. The effects of age on resting state functional connectivity of the basal ganglia from young to middle adulthood. Neuroimage 2015; 107:311-322. [PMID: 25514518 PMCID: PMC4300261 DOI: 10.1016/j.neuroimage.2014.12.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 11/24/2014] [Accepted: 12/05/2014] [Indexed: 12/16/2022] Open
Abstract
The basal ganglia nuclei are critical for a variety of cognitive and motor functions. Much work has shown age-related structural changes of the basal ganglia. Yet less is known about how the functional interactions of these regions with the cerebral cortex and the cerebellum change throughout the lifespan. Here, we took advantage of a convenient sample and examined resting state functional magnetic resonance imaging data from 250 adults 18 to 49 years of age, focusing specifically on the caudate nucleus, pallidum, putamen, and ventral tegmental area/substantia nigra (VTA/SN). There are a few main findings to report. First, with age, caudate head connectivity increased with a large region of ventromedial prefrontal/medial orbitofrontal cortex. Second, across all subjects, pallidum and putamen showed negative connectivity with default mode network (DMN) regions such as the ventromedial prefrontal cortex and posterior cingulate cortex, in support of anti-correlation of the "task-positive" network (TPN) and DMN. This negative connectivity was reduced with age. Furthermore, pallidum, posterior putamen and VTA/SN connectivity to other TPN regions, such as somatomotor cortex, decreased with age. These results highlight a distinct effect of age on cerebral functional connectivity of the dorsal striatum and VTA/SN from young to middle adulthood and may help research investigating the etiologies or monitoring outcomes of neuropsychiatric conditions that implicate dopaminergic dysfunction.
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Affiliation(s)
- Peter Manza
- Department of Psychiatry, Yale University, New Haven, CT 06519, USA; Department of Psychology, Stony Brook University, Stony Brook, NY 11790, USA
| | - Sheng Zhang
- Department of Psychiatry, Yale University, New Haven, CT 06519, USA
| | - Sien Hu
- Department of Psychiatry, Yale University, New Haven, CT 06519, USA
| | - Herta H Chao
- Department of Internal Medicine, Yale University, New Haven, CT 06519, USA; Medical Service, VA Connecticut Health Care System, West Haven, CT 06516, USA
| | - Hoi-Chung Leung
- Department of Psychology, Stony Brook University, Stony Brook, NY 11790, USA
| | - Chiang-Shan R Li
- Department of Psychiatry, Yale University, New Haven, CT 06519, USA; Department of Neurobiology, Yale University, New Haven, CT 06520, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06520, USA.
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Ikonomidou C. Matrix metalloproteinases and epileptogenesis. Mol Cell Pediatr 2014; 1:6. [PMID: 26567100 PMCID: PMC4530574 DOI: 10.1186/s40348-014-0006-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 08/13/2014] [Indexed: 01/30/2023] Open
Abstract
Matrix metalloproteinases are vital drivers of synaptic remodeling in health and disease. It is suggested that at early stages of epileptogenesis, inhibition of matrix metalloproteinases may help ameliorate cell death, aberrant network rewiring, and neuroinflammation and prevent development of epilepsy.
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Microglial displacement of inhibitory synapses provides neuroprotection in the adult brain. Nat Commun 2014; 5:4486. [PMID: 25047355 PMCID: PMC4109015 DOI: 10.1038/ncomms5486] [Citation(s) in RCA: 212] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 06/23/2014] [Indexed: 01/21/2023] Open
Abstract
Microglia actively survey the brain microenvironment and play essential roles in sculpting synaptic connections during brain development. While microglial functions in the adult brain are less clear, activated microglia can closely appose neuronal cell bodies and displace axosomatic presynaptic terminals. Microglia-mediated stripping of presynaptic terminals is considered neuroprotective, but the cellular and molecular mechanisms are poorly defined. Using 3D electron microscopy, we demonstrate that activated microglia displace inhibitory presynaptic terminals from cortical neurons in adult mice. Electrophysiological recordings further establish that the reduction in inhibitory GABAergic synapses increased synchronized firing of cortical neurons in γ-frequency band. Increased neuronal activity results in the calcium-mediated activation of CaM kinase IV, phosphorylation of CREB, increased expression of antiapoptotic and neurotrophic molecules and reduced apoptosis of cortical neurons following injury. These results indicate that activated microglia can protect the adult brain by migrating to inhibitory synapses and displacing them from cortical neurons. Microglia play essential roles in sculpting synaptic connections during brain development but their role in the adult brain is less clear. Here the authors show that activated microglia can prophylactically protect the adult rodent brain from injury by migrating to and displacing inhibitory synapses from cortical neurons.
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Hsieh JH, Stein DJ, Howells FM. The neurobiology of methamphetamine induced psychosis. Front Hum Neurosci 2014; 8:537. [PMID: 25100979 PMCID: PMC4105632 DOI: 10.3389/fnhum.2014.00537] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 07/01/2014] [Indexed: 11/18/2022] Open
Abstract
Chronic methamphetamine abuse commonly leads to psychosis, with positive and cognitive symptoms that are similar to those of schizophrenia. Methamphetamine induced psychosis (MAP) can persist and diagnoses of MAP often change to a diagnosis of schizophrenia over time. Studies in schizophrenia have found much evidence of cortical GABAergic dysfunction. Methamphetamine psychosis is a well studied model for schizophrenia, however there is little research on the effects of methamphetamine on cortical GABAergic function in the model, and the neurobiology of MAP is unknown. This paper reviews the effects of methamphetamine on dopaminergic pathways, with focus on its ability to increase glutamate release in the cortex. Excess cortical glutamate would likely damage GABAergic interneurons, and evidence of this disturbance as a result of methamphetamine treatment will be discussed. We propose that cortical GABAergic interneurons are particularly vulnerable to glutamate overflow as a result of subcellular location of NMDA receptors on interneurons in the cortex. Damage to cortical GABAergic function would lead to dysregulation of cortical signals, resulting in psychosis, and further support MAP as a model for schizophrenia.
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Affiliation(s)
- Jennifer H. Hsieh
- Department of Psychiatry and Mental Health, University of Cape TownWestern Cape, South Africa
| | | | - Fleur M. Howells
- Department of Psychiatry and Mental Health, University of Cape TownWestern Cape, South Africa
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De Montigny A, Elhiri I, Allyson J, Cyr M, Massicotte G. NMDA reduces Tau phosphorylation in rat hippocampal slices by targeting NR2A receptors, GSK3β, and PKC activities. Neural Plast 2013; 2013:261593. [PMID: 24349798 PMCID: PMC3856160 DOI: 10.1155/2013/261593] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/11/2013] [Indexed: 01/06/2023] Open
Abstract
The molecular mechanisms that regulate Tau phosphorylation are complex and currently incompletely understood. In the present study, pharmacological inhibitors were deployed to investigate potential processes by which the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors modulates Tau phosphorylation in rat hippocampal slices. Our results demonstrated that Tau phosphorylation at Ser199-202 residues was decreased in NMDA-treated hippocampal slices, an effect that was not reproduced at Ser262 and Ser404 epitopes. NMDA-induced reduction of Tau phosphorylation at Ser199-202 was further promoted when NR2A-containing receptors were pharmacologically isolated and were completely abrogated by the NR2A receptor antagonist NVP-AAM077. Compared with nontreated slices, we observed that NMDA receptor activation was reflected in high Ser9 and low Tyr216 phosphorylation of glycogen synthase kinase-3 beta (GSK3β), suggesting that NMDA receptor activation might diminish Tau phosphorylation via a pathway involving GSK3β inhibition. Accordingly, we found that GSK3β inactivation by a protein kinase C- (PKC-) dependent mechanism is involved in the NMDA-induced reduction of Tau phosphorylation at Ser199-202 epitopes. Taken together, these data indicate that NR2A receptor activation may be important in limiting Tau phosphorylation by a PKC/GSK3β pathway and strengthen the idea that these receptors might act as an important molecular device counteracting neuronal cell death mechanisms in various pathological conditions.
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Affiliation(s)
- Audrée De Montigny
- Groupe de Recherche en Neuroscience, Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada G9A 5H7
| | - Ismaël Elhiri
- Groupe de Recherche en Neuroscience, Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada G9A 5H7
| | - Julie Allyson
- Groupe de Recherche en Neuroscience, Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada G9A 5H7
| | - Michel Cyr
- Groupe de Recherche en Neuroscience, Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada G9A 5H7
| | - Guy Massicotte
- Groupe de Recherche en Neuroscience, Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada G9A 5H7
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Wang Y, Zhou TH, Zhi Z, Barakat A, Hlatky L, Querfurth H. Multiple effects of β-amyloid on single excitatory synaptic connections in the PFC. Front Cell Neurosci 2013; 7:129. [PMID: 24027495 PMCID: PMC3759796 DOI: 10.3389/fncel.2013.00129] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 07/29/2013] [Indexed: 01/09/2023] Open
Abstract
Prefrontal cortex (PFC) is recognized as an AD-vulnerable region responsible for defects in cognitive functioning. Pyramidal cell (PC) connections are typically facilitating (F) or depressing (D) in PFC. Excitatory post-synaptic potentials (EPSPs) were recorded using patch-clamp from single connections in PFC slices of rats and ferrets in the presence of β-amyloid (Aβ). Synaptic transmission was significantly enhanced or reduced depending on their intrinsic type (facilitating or depressing), Aβ species (Aβ 40 or Aβ 42) and concentration (1-200 nM vs. 0.3-1 μ M). Nanomolar Aβ 40 and Aβ 42 had opposite effects on F-connections, resulting in fewer or increased EPSP failure rates, strengthening or weakening EPSPs and enhancing or inhibiting short-term potentiation [STP: synaptic augmentation (SA) and post-tetanic potentiation (PTP)], respectively. High Aβ 40 concentrations induced inhibition regardless of synaptic type. D-connections were inhibited regardless of Aβ species or concentration. The inhibition induced with bath application was hard to recover by washout, but a complete recovery was obtained with brief local application and prompt washout. Our data suggests that Aβ 40 acts on the prefrontal neuronal network by modulating facilitating and depressing synapses. At higher levels, both Aβ 40 and Aβ 42 inhibit synaptic activity and cause irreversible toxicity once diffusely accumulated in the synaptic environment.
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Affiliation(s)
- Yun Wang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University Wenzhou, Zhejiang, China ; Steward St. Elizabeth's Medical Center, Tufts Medical School, Tufts University Boston, MA, USA
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Sun F, Jin K, Uteshev VV. A type-II positive allosteric modulator of α7 nAChRs reduces brain injury and improves neurological function after focal cerebral ischemia in rats. PLoS One 2013; 8:e73581. [PMID: 23951360 PMCID: PMC3739732 DOI: 10.1371/journal.pone.0073581] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 07/26/2013] [Indexed: 11/19/2022] Open
Abstract
In the absence of clinically-efficacious therapies for ischemic stroke there is a critical need for development of new therapeutic concepts and approaches for prevention of brain injury secondary to cerebral ischemia. This study tests the hypothesis that administration of PNU-120596, a type-II positive allosteric modulator (PAM-II) of α7 nicotinic acetylcholine receptors (nAChRs), as long as 6 hours after the onset of focal cerebral ischemia significantly reduces brain injury and neurological deficits in an animal model of ischemic stroke. Focal cerebral ischemia was induced by a transient (90 min) middle cerebral artery occlusion (MCAO). Animals were then subdivided into two groups and injected intravenously (i.v.) 6 hours post-MCAO with either 1 mg/kg PNU-120596 (treated group) or vehicle only (untreated group). Measurements of cerebral infarct volumes and neurological behavioral tests were performed 24 hrs post-MCAO. PNU-120596 significantly reduced cerebral infarct volume and improved neurological function as evidenced by the results of Bederson, rolling cylinder and ladder rung walking tests. These results forecast a high therapeutic potential for PAMs-II as effective recruiters and activators of endogenous α7 nAChR-dependent cholinergic pathways to reduce brain injury and improve neurological function after cerebral ischemic stroke.
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Affiliation(s)
- Fen Sun
- University of North Texas Health Science Center, Department of Pharmacology and Neuroscience, Fort Worth, TX, United States of America
| | - Kunlin Jin
- University of North Texas Health Science Center, Department of Pharmacology and Neuroscience, Fort Worth, TX, United States of America
| | - Victor V. Uteshev
- University of North Texas Health Science Center, Department of Pharmacology and Neuroscience, Fort Worth, TX, United States of America
- * E-mail:
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Lee W, Reyes RC, Gottipati MK, Lewis K, Lesort M, Parpura V, Gray M. Enhanced Ca(2+)-dependent glutamate release from astrocytes of the BACHD Huntington's disease mouse model. Neurobiol Dis 2013; 58:192-9. [PMID: 23756199 DOI: 10.1016/j.nbd.2013.06.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/09/2013] [Accepted: 06/02/2013] [Indexed: 11/29/2022] Open
Abstract
Huntington's disease (HD) causes preferential loss of a subset of neurons in the brain although the huntingtin protein is expressed broadly in various neural cell types, including astrocytes. Glutamate-mediated excitotoxicity is thought to cause selective neuronal injury, and brain astrocytes have a central role in regulating extracellular glutamate. To determine whether full-length mutant huntingtin expression causes a cell-autonomous phenotype and perturbs astrocyte gliotransmitter release, we studied cultured cortical astrocytes from BACHD mice. Here, we report augmented glutamate release through Ca(2+)-dependent exocytosis from BACHD astrocytes. Although such release is usually dependent on cytosolic Ca(2+) levels, surprisingly, we found that BACHD astrocytes displayed Ca(2+) dynamics comparable to those in wild type astrocytes. These results point to a possible involvement of other factors in regulating Ca(2+)-dependent/vesicular release of glutamate from astrocytes. We found a biochemical footprint that would lead to increased availability of cytosolic glutamate in BACHD astrocytes: i) augmented de novo glutamate synthesis due to an increase in the level of the astrocyte specific mitochondrial enzyme pyruvate carboxylase; and ii) unaltered conversion of glutamate to glutamine, as there were no changes in the expression level of the astrocyte specific enzyme glutamine synthetase. This work identifies a new mechanism in astrocytes that could lead to increased levels of extracellular glutamate in HD and thus may contribute to excitotoxicity in this devastating disease.
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Affiliation(s)
- William Lee
- Department of Neurobiology, University of Alabama, Birmingham, AL 35294, USA
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Li XB, Yang ZX, Yang L, Chen XL, Zhang K, Yang Q, Wu YM, Liu SB, Tao KS, Zhao MG. Neuroprotective effects of flax lignan against NMDA-induced neurotoxicity in vitro. CNS Neurosci Ther 2012; 18:927-33. [PMID: 22970936 DOI: 10.1111/cns.12003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 08/14/2012] [Accepted: 08/14/2012] [Indexed: 01/12/2023] Open
Abstract
AIMS Flax Lignan (FLL), a chemical widespread within the plant and animal kingdoms, has antioxidant, antiinfectious, and antitumor activities. However, little is known about the effects of FLL on the central nervous system (CNS). METHODS The neuroprotective actions of FLL against N-methyl-d-aspartate (NMDA) are investigated in primary cultured cortical neurons by MTT assay. The expression levels of proteins related to apoptosis and GluN2-containing receptor were detected by Western blot analysis. Intracellular Ca(2+) was measured under a confocal laser scanning microscope. RESULTS After challenged with 100 μM NMDA for 30 min, loss of cell viability and excessive apoptotic cell death were observed in cultured cortical neurons. FLL protected the neurons against the NMDA-induced cell loss in a concentration-dependent manner. FLL also significantly inhibited the neuronal apoptosis induced by NMDA exposure through reversing intracellular concentration of Ca(2+) overload and balancing of Bcl-2 and Bax expression. Furthermore, FLL significantly reversed the upregulation of GluN2B-containing NMDA receptors by exposure to NMDA, but did not affect the expression of GluN2A-containing NMDA receptor. CONCLUSIONS These findings suggest that FLL protects cortical neurons by inhibiting the expression of GluN2B-containing NMDA receptor and regulating the Bcl-2 family.
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Affiliation(s)
- Xu-Bo Li
- Department of Pharmacology, School of Pharmacy, Xijing Hospital, the Fourth Military Medical University, Xi'an, China
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41
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Abstract
Our elderly population is growing and declines in cognitive abilities, such as memory, can be costly, because it can interfere with a person's ability to live independently. The NMDA receptor is very important for many different forms of memory and this receptor is negatively affected by aging. This review examines the progress that has been made recently in characterizing selective vulnerabilities of different subunits and splice variants of the NMDA receptor to normal aging in C57BL/6 mice. Evidence is also presented for changes in the relationships of NMDA receptors to plasticity across aging. Recent interventions show that enhancing NMDA receptors in aged individuals is associated with improvements in memory, but mouse models of neurodegenerative diseases suggest that finding the right balance between too little and too much NMDA receptor activity will be the key to enhancing memory without inducing pathology.
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Affiliation(s)
- Kathy R Magnusson
- Department of Biomedical Sciences, College of Veterinary Medicine, Healthy Aging Program, Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA ■ Tel.: +1 541 737 6923 ■ ■
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Ferreiro E, Baldeiras I, Ferreira IL, Costa RO, Rego AC, Pereira CF, Oliveira CR. Mitochondrial- and endoplasmic reticulum-associated oxidative stress in Alzheimer's disease: from pathogenesis to biomarkers. Int J Cell Biol 2012; 2012:735206. [PMID: 22701485 PMCID: PMC3373122 DOI: 10.1155/2012/735206] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 04/06/2012] [Indexed: 12/23/2022] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia in the elderly, affecting several million of people worldwide. Pathological changes in the AD brain include the presence of amyloid plaques, neurofibrillary tangles, loss of neurons and synapses, and oxidative damage. These changes strongly associate with mitochondrial dysfunction and stress of the endoplasmic reticulum (ER). Mitochondrial dysfunction is intimately linked to the production of reactive oxygen species (ROS) and mitochondrial-driven apoptosis, which appear to be aggravated in the brain of AD patients. Concomitantly, mitochondria are closely associated with ER, and the deleterious crosstalk between both organelles has been shown to be involved in neuronal degeneration in AD. Stimuli that enhance expression of normal and/or folding-defective proteins activate an adaptive unfolded protein response (UPR) that, if unresolved, can cause apoptotic cell death. ER stress also induces the generation of ROS that, together with mitochondrial ROS and decreased activity of several antioxidant defenses, promotes chronic oxidative stress. In this paper we discuss the critical role of mitochondrial and ER dysfunction in oxidative injury in AD cellular and animal models, as well as in biological fluids from AD patients. Progress in developing peripheral and cerebrospinal fluid biomarkers related to oxidative stress will also be summarized.
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Affiliation(s)
- E. Ferreiro
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Largo Marquês de Pombal 3004-517, Coimbra, Portugal
| | - I. Baldeiras
- Faculty of Medicine, University of Coimbra, Rua Larga 3004-504, Coimbra, Portugal
- University Coimbra Hospital, 3000-075, Coimbra, Portugal
| | - I. L. Ferreira
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Largo Marquês de Pombal 3004-517, Coimbra, Portugal
| | - R. O. Costa
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Largo Marquês de Pombal 3004-517, Coimbra, Portugal
| | - A. C. Rego
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Largo Marquês de Pombal 3004-517, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Rua Larga 3004-504, Coimbra, Portugal
| | - C. F. Pereira
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Largo Marquês de Pombal 3004-517, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Rua Larga 3004-504, Coimbra, Portugal
| | - C. R. Oliveira
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Largo Marquês de Pombal 3004-517, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Rua Larga 3004-504, Coimbra, Portugal
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von Reyn CR, Mott RE, Siman R, Smith DH, Meaney DF. Mechanisms of calpain mediated proteolysis of voltage gated sodium channel α-subunits following in vitro dynamic stretch injury. J Neurochem 2012; 121:793-805. [PMID: 22428606 DOI: 10.1111/j.1471-4159.2012.07735.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although enhanced calpain activity is well documented after traumatic brain injury (TBI), the pathways targeting specific substrate proteolysis are less defined. Our past work demonstrated that calpain cleaves voltage gated sodium channel (NaCh) α-subunits in an in vitro TBI model. In this study, we investigated the pathways leading to NaCh cleavage utilizing our previously characterized in vitro TBI model, and determined the location of calpain activation within neuronal regions following stretch injury to micropatterned cultures. Calpain specific breakdown products of α-spectrin appeared within axonal, dendritic, and somatic regions 6 h after injury, concurrent with the appearance of NaCh α-subunit proteolysis in both whole cell or enriched axonal preparations. Direct pharmacological activation of either NMDA receptors (NMDArs) or NaChs resulted in NaCh proteolysis. Likewise, a chronic (6 h) dual inhibition of NMDArs/NaChs but not L-type voltage gated calcium channels significantly reduced NaCh proteolysis 6 h after mechanical injury. Interestingly, an early, transient (30 min) inhibition of NMDArs alone significantly reduced NaCh proteolysis. Although a chronic inhibition of calpain significantly reduced proteolysis, a transient inhibition of calpain immediately after injury failed to significantly attenuate NaCh proteolysis. These data suggest that both NMDArs and NaChs are key contributors to calpain activation after mechanical injury, and that a larger temporal window of sustained calpain activation needs consideration in developing effective treatments for TBI.
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Shi GX, Andres DA, Cai W. Ras family small GTPase-mediated neuroprotective signaling in stroke. Cent Nerv Syst Agents Med Chem 2012; 11:114-37. [PMID: 21521171 DOI: 10.2174/187152411796011349] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 01/18/2011] [Accepted: 03/22/2011] [Indexed: 12/31/2022]
Abstract
Selective neuronal cell death is one of the major causes of neuronal damage following stroke, and cerebral cells naturally mobilize diverse survival signaling pathways to protect against ischemia. Importantly, therapeutic strategies designed to improve endogenous anti-apoptotic signaling appear to hold great promise in stroke treatment. While a variety of complex mechanisms have been implicated in the pathogenesis of stroke, the overall mechanisms governing the balance between cell survival and death are not well-defined. Ras family small GTPases are activated following ischemic insults, and in turn, serve as intrinsic switches to regulate neuronal survival and regeneration. Their ability to integrate diverse intracellular signal transduction pathways makes them critical regulators and potential therapeutic targets for neuronal recovery after stroke. This article highlights the contribution of Ras family GTPases to neuroprotective signaling cascades, including mitogen-activated protein kinase (MAPK) family protein kinase- and AKT/PKB-dependent signaling pathways as well as the regulation of cAMP response element binding (CREB), Forkhead box O (FoxO) and hypoxiainducible factor 1(HIF1) transcription factors, in stroke.
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Affiliation(s)
- Geng-Xian Shi
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, 741 S. Limestone St., Lexington, KY 40536-0509, USA.
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Spaethling J, Le L, Meaney DF. NMDA receptor mediated phosphorylation of GluR1 subunits contributes to the appearance of calcium-permeable AMPA receptors after mechanical stretch injury. Neurobiol Dis 2012; 46:646-54. [PMID: 22426393 DOI: 10.1016/j.nbd.2012.03.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 01/30/2012] [Accepted: 03/01/2012] [Indexed: 10/28/2022] Open
Abstract
Alterations in neuronal cytosolic calcium is a key mediator of the traumatic brain injury (TBI) pathobiology, but less is known of the role and source of calcium in shaping early changes in synaptic receptors and neural circuits after TBI. In this study, we examined the calcium source and potential phosphorylation events leading to insertion of calcium-permeable AMPARs (CP-AMPARs) after in vitro traumatic brain injury, a receptor subtype that influences neural circuit dynamics for hours to days following injury. We found that both synaptic and NR2B-containing NMDARs contribute significantly to the calcium influx following stretch injury. Moreover, an early and sustained phosphorylation of the S-831 site of the GluR1 subunit appeared after mechanical injury, and this phosphorylation was blocked with the inhibition of either synaptic NMDARs or NR2B-containing NMDARs. In comparison, mechanical injury led to no significant change in the S-845 phosphorylation of the GluR1 subunit. Although no change in S-845 phosphorylation appeared in injured cultures, we observed that inhibition of NR2B-containing NMDARs significantly increased S-845 phosphorylation 1h after injury while blockade of synaptic NMDARs did not change S-845 phosphorylation at any time point following injury. These findings show that a broad class of NMDARs are activated in parallel and that targeting either subpopulation will reverse some of the consequences of mechanical injury, providing distinct paths to treat the effects of mechanical injury on neural circuits after TBI.
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Affiliation(s)
- Jennifer Spaethling
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104, United States
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46
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Sodero AO, Vriens J, Ghosh D, Stegner D, Brachet A, Pallotto M, Sassoè-Pognetto M, Brouwers JF, Helms JB, Nieswandt B, Voets T, Dotti CG. Cholesterol loss during glutamate-mediated excitotoxicity. EMBO J 2012; 31:1764-73. [PMID: 22343944 DOI: 10.1038/emboj.2012.31] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 01/10/2012] [Indexed: 11/09/2022] Open
Abstract
The deregulation of brain cholesterol metabolism is typical in acute neuronal injury (such as stroke, brain trauma and epileptic seizures) and chronic neurodegenerative diseases (Alzheimer's disease). Since both conditions are characterized by excessive stimulation of glutamate receptors, we have here investigated to which extent excitatory neurotransmission plays a role in brain cholesterol homeostasis. We show that a short (30 min) stimulation of glutamatergic neurotransmission induces a small but significant loss of membrane cholesterol, which is paralleled by release to the extracellular milieu of the metabolite 24S-hydroxycholesterol. Consistent with a cause-effect relationship, knockdown of the enzyme cholesterol 24-hydroxylase (CYP46A1) prevented glutamate-mediated cholesterol loss. Functionally, the loss of cholesterol modulates the magnitude of the depolarization-evoked calcium response. Mechanistically, glutamate-induced cholesterol loss requires high levels of intracellular Ca(2+), a functional stromal interaction molecule 2 (STIM2) and mobilization of CYP46A1 towards the plasma membrane. This study underscores the key role of excitatory neurotransmission in the control of membrane lipid composition, and consequently in neuronal membrane organization and function.
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Affiliation(s)
- Alejandro O Sodero
- VIB Center for Biology of Disease, Katholieke Universiteit Leuven, Leuven, Belgium
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Uteshev VV. α7 nicotinic ACh receptors as a ligand-gated source of Ca(2+) ions: the search for a Ca(2+) optimum. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:603-38. [PMID: 22453962 DOI: 10.1007/978-94-007-2888-2_27] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The spatiotemporal distribution of cytosolic Ca(2+) ions is a key determinant of neuronal behavior and survival. Distinct sources of Ca(2+) ions including ligand- and voltage-gated Ca(2+) channels contribute to intracellular Ca(2+) homeostasis. Many normal physiological and therapeutic neuronal functions are Ca(2+)-dependent, however an excess of cytosolic Ca(2+) or a lack of the appropriate balance between Ca(2+) entry and clearance may destroy cellular integrity and cause cellular death. Therefore, the existence of optimal spatiotemporal patterns of cytosolic Ca(2+) elevations and thus, optimal activation of ligand- and voltage-gated Ca(2+) ion channels are postulated to benefit neuronal function and survival. Alpha7 nicotinic -acetylcholine receptors (nAChRs) are highly permeable to Ca(2+) ions and play an important role in modulation of neurotransmitter release, gene expression and neuroprotection in a variety of neuronal and non-neuronal cells. In this review, the focus is placed on α7 nAChR-mediated currents and Ca(2+) influx and how this source of Ca(2+) entry compares to NMDA receptors in supporting cytosolic Ca(2+) homeostasis, neuronal function and survival.
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Affiliation(s)
- Victor V Uteshev
- Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107, USA.
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Beconi MG, Howland D, Park L, Lyons K, Giuliano J, Dominguez C, Munoz-Sanjuan I, Pacifici R. Pharmacokinetics of memantine in rats and mice. PLOS CURRENTS 2011; 3:RRN1291. [PMID: 22307216 PMCID: PMC3269340 DOI: 10.1371/currents.rrn1291] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 12/15/2011] [Indexed: 11/18/2022]
Abstract
To evaluate the potential of memantine as a therapeutic agent for Huntington’s disease (HD) we have undertaken a series of in vitro, ex vivo and whole animal studies to characterize its pharmacokinetics (PK) and pharmacodynamics (PD) in rats and mice. Results from these studies will enable determination of memantine exposures needed to engage the related functional PD marker and help predict the dose regimen for clinical trials to test its proposed mechanism of action; the selective blockade of extrasynaptic, but not synaptic, NMDA receptors. The studies reported here describe the PK of memantine in rats and mice at low (1 mg/kg) and high (10 mg/kg) doses. Our studies indicate that the clearance mechanisms of memantine in rats and mice are different from those in human, and that clearance needs to be taken into account when extrapolating to the human. In rats only, there is a significant metabolic contribution to memantine clearance at lower dose levels. While memantine is primarily cleared renally in all three species, the proportion of total systemic clearance above the glomerular filtration rate (GFR) is much higher in rats and mice (~13, 4.5, and 1.4 times higher than GFR in rats, mice, and humans, respectively), suggesting that the contribution of active transport to memantine elimination in rats and mice is more significant than in the human. In rats and mice, memantine had a short half-life (<4 h) and steep Cmax/Cmin ratios (>100). In the human, the half-life of memantine was reported to be very long (60-80 h) with a Cmax/Cmin ratio at steady state concentrations of ~1.5. A small change in the clearance of memantine - for example due to renal impairment or competition for the elimination pathway with a co-administered drug - will likely affect exposure and, therefore, the selectivity of memantine on NMDA receptors . The PK differences observed between these species demonstrate that the PK in mice and rats cannot be directly extrapolated to the human. Further, the relationship between the plasma concentration (and therefore dose) needed to elicit a mechanism-related in vivo functional effect (PD readout) while maintaining the selectivity of the extrasynaptic blockade of the NMDA receptors needs to be established before clinical trials can be appropriately planned.
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Affiliation(s)
- Maria G Beconi
- Director, DMPK, CHDI Management/CHDI Foundation, Princeton, NJ; Director of In Vivo Biology, CHDI Foundation Inc; Director, PreClinical Research, CHDI Foundation, Inc; Pharmacokinetic consultant for the CHDI Foundation, Holland NY; CHDI Foundation, Inc.; VP, Chemistry CHDI Foundation/ CHDI Management Inc. Los Angeles CA; VP Translational Biology, CHDI Management/CHDI Foundation Inc., Los Angeles (USA) and CSO - Drug Discovery & Development, CHDI Foundation / CHDI Management
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Abstract
The time course of excitatory synaptic currents, the major means of fast communication between neurons of the central nervous system, is encoded in the dynamic behaviour of post-synaptic glutamate-activated channels. First-pass attempts to explain the glutamate-elicited currents with mathematical models produced reaction mechanisms that included only the most basic functionally defined states: resting vs. liganded, closed vs. open, responsive vs. desensitized. In contrast, single-molecule observations afforded by the patch-clamp technique revealed an unanticipated kinetic multiplicity of transitions: from microseconds-lasting flickers to minutes-long modes. How these kinetically defined events impact the shape of the synaptic response, how they relate to rearrangements in receptor structure, and whether and how they are physiologically controlled represent currently active research directions. Modal gating, which refers to the slowest, least frequently observed ion-channel transitions, has been demonstrated for representatives of all ion channel families. However, reaction schemes have been largely confined to the short- and medium-range time scales. For glutamate receptors as well, modal gating has only recently come under rigorous scrutiny. This article reviews the evidence for modal gating of glutamate receptors and the still developing hypotheses about the mechanism(s) by which modal shifts occur and the ways in which they may impact the time course of synaptic transmission.
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Affiliation(s)
- Gabriela K Popescu
- Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, Buffalo, NY 14214, USA.
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50
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Soluble Aβ oligomers inhibit long-term potentiation through a mechanism involving excessive activation of extrasynaptic NR2B-containing NMDA receptors. J Neurosci 2011; 31:6627-38. [PMID: 21543591 DOI: 10.1523/jneurosci.0203-11.2011] [Citation(s) in RCA: 474] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In Alzheimer's disease (AD), dementia severity correlates strongly with decreased synapse density in hippocampus and cortex. Numerous studies report that hippocampal long-term potentiation (LTP) can be inhibited by soluble oligomers of amyloid β-protein (Aβ), but the synaptic elements that mediate this effect remain unclear. We examined field EPSPs and whole-cell recordings in wild-type mouse hippocampal slices. Soluble Aβ oligomers from three distinct sources (cultured cells, AD cortex, or synthetic peptide) inhibited LTP, and this was prevented by the selective NR2B inhibitors ifenprodil and Ro 25-6981. Soluble Aβ enhanced NR2B-mediated NMDA currents and extrasynaptic responses; these effects were mimicked by the glutamate reuptake inhibitor dl-threo-β-benzyloxyaspartic acid. Downstream, an Aβ-mediated rise in p38 mitogen-activated protein kinase (MAPK) activation was followed by downregulation of cAMP response element-binding protein, and LTP impairment was prevented by inhibitors of p38 MAPK or calpain. Thus, soluble Aβ oligomers at low nanomolar levels present in AD brain increase activation of extrasynaptic NR2B-containing receptors, thereby impairing synaptic plasticity.
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