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Aroniadou-Anderjaska V, Figueiredo TH, De Araujo Furtado M, Pidoplichko VI, Lumley LA, Braga MFM. Alterations in GABA A receptor-mediated inhibition triggered by status epilepticus and their role in epileptogenesis and increased anxiety. Neurobiol Dis 2024; 200:106633. [PMID: 39117119 DOI: 10.1016/j.nbd.2024.106633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 07/31/2024] [Accepted: 08/05/2024] [Indexed: 08/10/2024] Open
Abstract
The triggers of status epilepticus (SE) in non-epileptic patients can vary widely, from idiopathic causes to exposure to chemoconvulsants. Regardless of its etiology, prolonged SE can cause significant brain damage, commonly resulting in the development of epilepsy, which is often accompanied by increased anxiety. GABAA receptor (GABAAR)-mediated inhibition has a central role among the mechanisms underlying brain damage and the ensuing epilepsy and anxiety. During SE, calcium influx primarily via ionotropic glutamate receptors activates signaling cascades which trigger a rapid internalization of synaptic GABAARs; this weakens inhibition, exacerbating seizures and excitotoxicity. GABAergic interneurons are more susceptible to excitotoxic death than principal neurons. During the latent period of epileptogenesis, the aberrant reorganization in synaptic interactions that follow interneuronal loss in injured brain regions, leads to the formation of hyperexcitable, seizurogenic neuronal circuits, along with disturbances in brain oscillatory rhythms. Reduction in the spontaneous, rhythmic "bursts" of IPSCs in basolateral amygdala neurons is likely to play a central role in anxiogenesis. Protecting interneurons during SE is key to preventing both epilepsy and anxiety. Antiglutamatergic treatments, including antagonism of calcium-permeable AMPA receptors, can be expected to control seizures and reduce excitotoxicity not only by directly suppressing hyperexcitation, but also by counteracting the internalization of synaptic GABAARs. Benzodiazepines, as delayed treatment of SE, have low efficacy due to the reduction and dispersion of their targets (the synaptic GABAARs), but also because themselves contribute to further reduction of available GABAARs at the synapse; furthermore, benzodiazepines may be completely ineffective in the immature brain.
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Affiliation(s)
- Vassiliki Aroniadou-Anderjaska
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA; Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
| | - Taiza H Figueiredo
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
| | - Marcio De Araujo Furtado
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Volodymyr I Pidoplichko
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
| | - Lucille A Lumley
- U.S. Army Medical Research Institute of Chemical Defense, Aberdeen, Proving Ground, MD, USA.
| | - Maria F M Braga
- Department of Anatomy, Physiology, and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA; Department of Psychiatry, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
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Wetzel A, Lei SH, Liu T, Hughes MP, Peng Y, McKay T, Waddington SN, Grannò S, Rahim AA, Harvey K. Dysregulated Wnt and NFAT signaling in a Parkinson's disease LRRK2 G2019S knock-in model. Sci Rep 2024; 14:12393. [PMID: 38811759 PMCID: PMC11137013 DOI: 10.1038/s41598-024-63130-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 05/24/2024] [Indexed: 05/31/2024] Open
Abstract
Parkinson's disease (PD) is a progressive late-onset neurodegenerative disease leading to physical and cognitive decline. Mutations of leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of PD. LRRK2 is a complex scaffolding protein with known regulatory roles in multiple molecular pathways. Two prominent examples of LRRK2-modulated pathways are Wingless/Int (Wnt) and nuclear factor of activated T-cells (NFAT) signaling. Both are well described key regulators of immune and nervous system development as well as maturation. The aim of this study was to establish the physiological and pathogenic role of LRRK2 in Wnt and NFAT signaling in the brain, as well as the potential contribution of the non-canonical Wnt/Calcium pathway. In vivo cerebral Wnt and NFATc1 signaling activity was quantified in LRRK2 G2019S mutant knock-in (KI) and LRRK2 knockout (KO) male and female mice with repeated measures over 28 weeks, employing lentiviral luciferase biosensors, and analyzed using a mixed-effect model. To establish spatial resolution, we investigated tissues, and primary neuronal cell cultures from different brain regions combining luciferase signaling activity, immunohistochemistry, qPCR and western blot assays. Results were analyzed by unpaired t-test with Welch's correction or 2-way ANOVA with post hoc corrections. In vivo Wnt signaling activity in LRRK2 KO and LRRK2 G2019S KI mice was increased significantly ~ threefold, with a more pronounced effect in males (~ fourfold) than females (~ twofold). NFATc1 signaling was reduced ~ 0.5-fold in LRRK2 G2019S KI mice. Brain tissue analysis showed region-specific expression changes in Wnt and NFAT signaling components. These effects were predominantly observed at the protein level in the striatum and cerebral cortex of LRRK2 KI mice. Primary neuronal cell culture analysis showed significant genotype-dependent alterations in Wnt and NFATc1 signaling under basal and stimulated conditions. Wnt and NFATc1 signaling was primarily dysregulated in cortical and hippocampal neurons respectively. Our study further built on knowledge of LRRK2 as a Wnt and NFAT signaling protein. We identified complex changes in neuronal models of LRRK2 PD, suggesting a role for mutant LRRK2 in the dysregulation of NFAT, and canonical and non-canonical Wnt signaling.
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Affiliation(s)
- Andrea Wetzel
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
- Institute of Physiology, Medical Faculty, Otto-von-Guericke-University, 39120, Magdeburg, Germany
| | - Si Hang Lei
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Tiansheng Liu
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Michael P Hughes
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Yunan Peng
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Tristan McKay
- Department of Life Sciences, Dalton Building, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Simon N Waddington
- Gene Transfer Technology Group, University College London, 86-96 Chenies Mews, London, WC1E 6HXZ, UK
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Simone Grannò
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
- Division of Neurosurgery, Department of Clinical Neurosciences, Geneva University Hospitals, Rue Gabrielle-Perret Gentil 4, 1205, Geneva, Switzerland
| | - Ahad A Rahim
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Kirsten Harvey
- Department of Pharmacology, UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK.
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Han QT, Yang WQ, Zang C, Zhou L, Zhang CJ, Bao X, Cai J, Li F, Shi Q, Wang XL, Qu J, Zhang D, Yu SS. The toxic natural product tutin causes epileptic seizures in mice by activating calcineurin. Signal Transduct Target Ther 2023; 8:101. [PMID: 36894540 PMCID: PMC9998865 DOI: 10.1038/s41392-023-01312-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 10/12/2022] [Accepted: 01/06/2023] [Indexed: 03/11/2023] Open
Abstract
Tutin, an established toxic natural product that causes epilepsy in rodents, is often used as a tool to develop animal model of acute epileptic seizures. However, the molecular target and toxic mechanism of tutin were unclear. In this study, for the first time, we conducted experiments to clarify the targets in tutin-induced epilepsy using thermal proteome profiling. Our studies showed that calcineurin (CN) was a target of tutin, and that tutin activated CN, leading to seizures. Binding site studies further established that tutin bound within the active site of CN catalytic subunit. CN inhibitor and calcineurin A (CNA) knockdown experiments in vivo proved that tutin induced epilepsy by activating CN, and produced obvious nerve damage. Together, these findings revealed that tutin caused epileptic seizures by activating CN. Moreover, further mechanism studies found that N-methyl-D-aspartate (NMDA) receptors, gamma-aminobutyric acid (GABA) receptors and voltage- and Ca2+- activated K+ (BK) channels might be involved in related signaling pathways. Our study fully explains the convulsive mechanism of tutin, which provides new ideas for epilepsy treatment and drug development.
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Affiliation(s)
- Qing-Tong Han
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Wan-Qi Yang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Caixia Zang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Linchao Zhou
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Chong-Jing Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Xiuqi Bao
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Jie Cai
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Fangfei Li
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Qinyan Shi
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Xiao-Liang Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Jing Qu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China.
| | - Dan Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China.
| | - Shi-Shan Yu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China.
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Warlick H, Leon L, Patel R, Filoramo S, Knipe R, Joubran E, Levy A, Nguyen H, Rey J. Application of gabapentinoids and novel compounds for the treatment of benzodiazepine dependence: the glutamatergic model. Mol Biol Rep 2023; 50:1765-1784. [PMID: 36456769 DOI: 10.1007/s11033-022-08110-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 11/09/2022] [Indexed: 12/04/2022]
Abstract
BACKGROUND Current approaches for managing benzodiazepine (BZD) withdrawal symptoms are daunting for clinicians and patients, warranting novel treatment and management strategies. This review discusses the pharmacodynamic properties of BZDs, gabapentinoids (GBPs), endozepines, and novel GABAergic compounds associated with potential clinical benefits for BZD-dependent patients. The objective of this study was to review the complex neuromolecular changes occurring within the GABAergic and glutamatergic systems during the BZD tolerance and withdrawal periods while also examining the mechanism by which GBPs and alternative pharmacological therapies may attenuate withdrawal symptoms. METHODS AND RESULTS An elaborative literature review was conducted using multiple platforms, including the National Center for Biotechnology (NCBI), AccessMedicine, ScienceDirect, pharmacology textbooks, clinical trial data, case reports, and PubChem. Our literature analysis revealed that many distinctive neuroadaptive mechanisms are involved in the GABAergic and glutamatergic systems during BZD tolerance and withdrawal. Based on this data, we hypothesize that GBPs may attenuate the overactive glutamatergic system during the withdrawal phase by an indirect presynaptic glutamatergic mechanism dependent on the α2δ1 subunit expression. CONCLUSIONS GBPs may benefit individuals undergoing BZD withdrawal, given that the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor current significantly increases during abrupt BZD withdrawal in animal studies. This may be a conceivable explanation for the effectiveness of GBPs in treating both alcohol withdrawal symptoms and BZD withdrawal symptoms in some recent studies. Finally, natural and synthetic GABAergic compounds with unique pharmacodynamic properties were found to exert potential clinical benefits as BZD substitutes in animal studies, though human studies are lacking.
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Affiliation(s)
- Halford Warlick
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA.
| | - Lexie Leon
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Rudresh Patel
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Stefanie Filoramo
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Ryan Knipe
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Ernesto Joubran
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Arkene Levy
- Dr. Kiran C. Patel College of Allopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Hoang Nguyen
- Dr. Kiran C. Patel College Of Osteopathic Medicine, Nova Southeastern University, Davie, FL, USA
| | - Jose Rey
- College of Pharmacy, Nova Southeastern University, Davie, FL, USA
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GABA A and GABA B Receptors Mediate GABA-Induced Intracellular Ca 2+ Signals in Human Brain Microvascular Endothelial Cells. Cells 2022; 11:cells11233860. [PMID: 36497118 PMCID: PMC9739010 DOI: 10.3390/cells11233860] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/17/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022] Open
Abstract
Numerous studies recently showed that the inhibitory neurotransmitter, γ-aminobutyric acid (GABA), can stimulate cerebral angiogenesis and promote neurovascular coupling by activating the ionotropic GABAA receptors on cerebrovascular endothelial cells, whereas the endothelial role of the metabotropic GABAB receptors is still unknown. Preliminary evidence showed that GABAA receptor stimulation can induce an increase in endothelial Ca2+ levels, but the underlying signaling pathway remains to be fully unraveled. In the present investigation, we found that GABA evoked a biphasic elevation in [Ca2+]i that was initiated by inositol-1,4,5-trisphosphate- and nicotinic acid adenine dinucleotide phosphate-dependent Ca2+ release from neutral and acidic Ca2+ stores, respectively, and sustained by store-operated Ca2+ entry. GABAA and GABAB receptors were both required to trigger the endothelial Ca2+ response. Unexpectedly, we found that the GABAA receptors signal in a flux-independent manner via the metabotropic GABAB receptors. Likewise, the full Ca2+ response to GABAB receptors requires functional GABAA receptors. This study, therefore, sheds novel light on the molecular mechanisms by which GABA controls endothelial signaling at the neurovascular unit.
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Control of cell surface expression of GABA A receptors by a conserved region at the end of the N-terminal extracellular domain of receptor subunits. J Biol Chem 2022; 298:102590. [PMID: 36244453 PMCID: PMC9672411 DOI: 10.1016/j.jbc.2022.102590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 11/07/2022] Open
Abstract
Type A γ-aminobutyric acid receptors (GABAARs) represent a family of pentameric GABA-gated Cl-/HCO3- ion channels which mediate inhibitory transmission in the central nervous system. Cell surface expression of GABAARs, a prerequisite for their function, is dependent on the appropriate assembly of the receptor subunits and their transient interactions with molecular chaperones within the endoplasmic reticulum (ER) and Golgi apparatus. Here, we describe a highly conserved amino acid sequence within the extracellular N-terminal domain of the receptor subunits adjoining the first transmembrane domain as a region important for GABAAR processing within the ER. Modifications of this region in the α1, β3, and γ2 subunits using insertion or site-directed mutagenesis impaired GABAAR trafficking to the cell surface in heterologous cell systems although they had no effect on the subunit assembly. We found that mutated receptors accumulated in the ER where they were shown to associate with chaperones calnexin, BiP, and Grp94. However, their surface expression was increased when ER-associated degradation or proteosome function was inhibited, while modulation of ER calcium stores had little effect. When compared to the wt, mutated receptors showed decreased interaction with calnexin, similar binding to BiP, and increased association with Grp94. Structural modeling of calnexin interaction with the wt or mutated GABAAR revealed that disruption in structure caused by mutations in the conserved region adjoining the first transmembrane domain may impair calnexin binding. Thus, this previously uncharacterized region plays an important role in intracellular processing of GABAARs at least in part by stabilizing their interaction with calnexin.
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Chen L, Song M, Yao C. Calcineurin in development and disease. Genes Dis 2022; 9:915-927. [PMID: 35685477 PMCID: PMC9170610 DOI: 10.1016/j.gendis.2021.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/27/2021] [Accepted: 03/05/2021] [Indexed: 12/26/2022] Open
Abstract
Calcineurin (CaN) is a unique calcium (Ca2+) and calmodulin (CaM)-dependent serine/threonine phosphatase that becomes activated in the presence of increased intracellular Ca2+ level. CaN then functions to dephosphorylate target substrates including various transcription factors, receptors, and channels. Once activated, the CaN signaling pathway participates in the development of multiple organs as well as the onset and progression of various diseases via regulation of different cellular processes. Here, we review current literature regarding the structural and functional properties of CaN, highlighting its crucial role in the development and pathogenesis of immune system disorders, neurodegenerative diseases, kidney disease, cardiomyopathy and cancer.
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Affiliation(s)
- Lei Chen
- Department of Blood Transfusion, First Affiliated Hospital, The Third Military Medical University (Army Medical University), Chongqing 400038, PR China
| | - Min Song
- Department of Blood Transfusion, First Affiliated Hospital, The Third Military Medical University (Army Medical University), Chongqing 400038, PR China
| | - Chunyan Yao
- Department of Blood Transfusion, First Affiliated Hospital, The Third Military Medical University (Army Medical University), Chongqing 400038, PR China
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Tipton AE, Russek SJ. Regulation of Inhibitory Signaling at the Receptor and Cellular Level; Advances in Our Understanding of GABAergic Neurotransmission and the Mechanisms by Which It Is Disrupted in Epilepsy. Front Synaptic Neurosci 2022; 14:914374. [PMID: 35874848 PMCID: PMC9302637 DOI: 10.3389/fnsyn.2022.914374] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/17/2022] [Indexed: 11/13/2022] Open
Abstract
Inhibitory signaling in the brain organizes the neural circuits that orchestrate how living creatures interact with the world around them and how they build representations of objects and ideas. Without tight control at multiple points of cellular engagement, the brain’s inhibitory systems would run down and the ability to extract meaningful information from excitatory events would be lost leaving behind a system vulnerable to seizures and to cognitive decline. In this review, we will cover many of the salient features that have emerged regarding the dynamic regulation of inhibitory signaling seen through the lens of cell biology with an emphasis on the major building blocks, the ligand-gated ion channel receptors that are the first transduction point when the neurotransmitter GABA is released into the synapse. Epilepsy association will be used to indicate importance of key proteins and their pathways to brain function and to introduce novel areas for therapeutic intervention.
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Affiliation(s)
- Allison E. Tipton
- Graduate Program for Neuroscience, Boston University, Boston, MA, United States
- Biomolecular Pharmacology Program, Boston University School of Medicine, Boston, MA, United States
- Boston University MD/PhD Training Program, Boston, MA, United States
| | - Shelley J. Russek
- Biomolecular Pharmacology Program, Boston University School of Medicine, Boston, MA, United States
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States
- Center for Systems Neuroscience, Boston University, Boston, MA, United States
- Boston University MD/PhD Training Program, Boston, MA, United States
- *Correspondence: Shelley J. Russek,
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Anxiety and hippocampal neuronal activity: Relationship and potential mechanisms. COGNITIVE, AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2022; 22:431-449. [PMID: 34873665 DOI: 10.3758/s13415-021-00973-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/11/2021] [Indexed: 12/15/2022]
Abstract
The hippocampus has been implicated in modulating anxiety. It interacts with a variety of brain regions, both cortical and subcortical areas regulating emotion and stress responses, including prefrontal cortex, amygdala, hypothalamus, and the nucleus accumbens, to adjust anxiety levels in response to a variety of stressful conditions. Growing evidence indicates that anxiety is associated with increased neuronal excitability in the hippocampus, and alterations in local regulation of hippocampal excitability have been suggested to underlie behavioral disruptions characteristic of certain anxiety disorders. Furthermore, studies have shown that some anxiolytics can treat anxiety by altering the excitability and plasticity of hippocampal neurons. Hence, identifying cellular and molecular mechanisms and neural circuits that regulate hippocampal excitability in anxiety may be beneficial for developing targeted interventions for treatment of anxiety disorders particularly for the treatment-resistant cases. We first briefly review a role of the hippocampus in fear. We then review the evidence indicating a relationship between the hippocampal activity and fear/anxiety and discuss some possible mechanisms underlying stress-induced hippocampal excitability and anxiety-related behavior.
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Using the Intranasal Route to Administer Drugs to Treat Neurological and Psychiatric Illnesses: Rationale, Successes, and Future Needs. CNS Drugs 2022; 36:739-770. [PMID: 35759210 PMCID: PMC9243954 DOI: 10.1007/s40263-022-00930-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/19/2022] [Indexed: 11/17/2022]
Abstract
While the intranasal administration of drugs to the brain has been gaining both research attention and regulatory success over the past several years, key fundamental and translational challenges remain to fully leveraging the promise of this drug delivery pathway for improving the treatment of various neurological and psychiatric illnesses. In response, this review highlights the current state of understanding of the nose-to-brain drug delivery pathway and how both biological and clinical barriers to drug transport using the pathway can been addressed, as illustrated by demonstrations of how currently approved intranasal sprays leverage these pathways to enable the design of successful therapies. Moving forward, aiming to better exploit the understanding of this fundamental pathway, we also outline the development of nanoparticle systems that show improvement in delivering approved drugs to the brain and how engineered nanoparticle formulations could aid in breakthroughs in terms of delivering emerging drugs and therapeutics while avoiding systemic adverse effects.
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Huang Z, Niu L. RNA aptamers for AMPA receptors. Neuropharmacology 2021; 199:108761. [PMID: 34509496 DOI: 10.1016/j.neuropharm.2021.108761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 08/07/2021] [Accepted: 08/19/2021] [Indexed: 12/16/2022]
Abstract
RNA aptamers are single-stranded RNA molecules, and they are selected against a target of interest so that they can bind to and modulate the activity of the target, such as inhibiting the target activity, with high potency and selectivity. Antagonists, such as RNA aptamers, acting on AMPA receptors, a major subtype of ionotropic glutamate receptors, are potential drug candidates for treatment of a number of CNS diseases that involve excessive receptor activation and/or elevated receptor expression. Here we review the approach to discover RNA aptamers targeting AMPA receptors from a random sequence library (∼1014 sequences) through a process called systematic evolution of ligands by exponential enrichment (SELEX). As compared with small-molecule compounds, RNA aptamers are a new class of regulatory agents with interesting and desirable pharmacological properties. Some AMPA receptor aptamers we have developed are presented in this review. The promises and challenges of translating RNA aptamers into potential drugs and treatment options are also discussed. This article is part of the special Issue on 'Glutamate Receptors - AMPA receptors'.
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Affiliation(s)
- Zhen Huang
- Chemistry Department, Center for Neuroscience Research, University at Albany, State University of New York (SUNY), Albany, NY, USA
| | - Li Niu
- Chemistry Department, Center for Neuroscience Research, University at Albany, State University of New York (SUNY), Albany, NY, USA.
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12
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Qin J, Wei T, Chen H, Lin X, Qin D, Wei F, Liu P, Ye W, Su J. Salicylate Induced GABAAR Internalization by Dopamine D1-Like Receptors Involving Protein Kinase C (PKC) in Spiral Ganglion Neurons. Med Sci Monit 2021; 27:e933278. [PMID: 34657931 PMCID: PMC8532520 DOI: 10.12659/msm.933278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Sodium salicylate (SS) induces excitotoxicity of spiral ganglion neurons (SGNs) by inhibiting the response of γ-aminobutyric acid type A receptors (GABAARs). Our previous studies have shown that SS can increase the internalization of GABAARs on SGNs, which involves dopamine D1-like receptors (D1Rs) and related signaling pathways. In this study, we aimed to explore the role of D1Rs and their downstream molecule protein kinase C (PKC) in the process of SS inhibiting GABAARs. MATERIAL AND METHODS The expression of D1Rs and GABARγ2 on rat cochlear SGNs cultured in vitro was tested by immunofluorescence. Then, the SGNs were exposed to SS, D1R agonist (SKF38393), D1R antagonist (SCH23390), clathrin/dynamin-mediated endocytosis inhibitor (dynasore), and PKC inhibitor (Bisindolylmaleimide I). Western blotting and whole-cell patch clamp technique were used to assess the changes of surface and total protein of GABARγ2 and GABA-activated currents. RESULTS Immunofluorescence showed that D1 receptors (DRD1) were expressed on SGNs. Data from western blotting showed that SS promoted the internalization of cell surface GABAARs, and activating D1Rs had the same result. Inhibiting D1Rs and PKC decreased the internalization of GABAARs. Meanwhile, the phosphorylation level of GABAARγ2 S327 affected by PKC was positively correlated with the degree of internalization of GABAARs. Moreover, whole-cell patch clamp recording showed that inhibition of D1Rs or co-inhibition of D1Rs and PKC attenuated the inhibitory effect of SS on GABA-activated currents. CONCLUSIONS D1Rs mediate the GABAAR internalization induced by SS via a PKC-dependent manner and participate in the excitotoxic process of SGNs.
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Affiliation(s)
- Jiangyuan Qin
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Tingjia Wei
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Huiying Chen
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Xiaoyu Lin
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Danxue Qin
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Fangyu Wei
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Peiqiang Liu
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Wenhua Ye
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Jiping Su
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
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13
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Anderson LL, Heblinski M, Absalom NL, Hawkins NA, Bowen M, Benson MJ, Zhang F, Bahceci D, Doohan PT, Chebib M, McGregor IS, Kearney JA, Arnold JC. Cannabigerolic acid, a major biosynthetic precursor molecule in cannabis, exhibits divergent effects on seizures in mouse models of epilepsy. Br J Pharmacol 2021; 178:4826-4841. [PMID: 34384142 PMCID: PMC9292928 DOI: 10.1111/bph.15661] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/26/2021] [Accepted: 08/10/2021] [Indexed: 11/28/2022] Open
Abstract
Background and Purpose Cannabis has been used to treat epilepsy for millennia, with such use validated by regulatory approval of cannabidiol (CBD) for Dravet syndrome. Unregulated artisanal cannabis‐based products used to treat children with intractable epilepsies often contain relatively low doses of CBD but are enriched in other phytocannabinoids. This raises the possibility that other cannabis constituents might have anticonvulsant properties. Experimental Approach We used the Scn1a+/− mouse model of Dravet syndrome to investigate the cannabis plant for phytocannabinoids with anticonvulsant effects against hyperthermia‐induced seizures. The most promising, cannabigerolic acid (CBGA), was further examined against spontaneous seizures and survival in Scn1a+/− mice and in electroshock seizure models. Pharmacological effects of CBGA were surveyed across multiple drug targets. Key Results The initial screen identified three phytocannabinoids with novel anticonvulsant properties: CBGA, cannabidivarinic acid (CBDVA) and cannabigerovarinic acid (CBGVA). CBGA was most potent and potentiated the anticonvulsant effects of clobazam against hyperthermia‐induced and spontaneous seizures, and was anticonvulsant in the MES threshold test. However, CBGA was proconvulsant in the 6‐Hz threshold test and a high dose increased spontaneous seizure frequency in Scn1a+/− mice. CBGA was found to interact with numerous epilepsy‐relevant targets including GPR55, TRPV1 channels and GABAA receptors. Conclusion and Implications These results suggest that CBGA, CBDVA and CBGVA may contribute to the effects of cannabis‐based products in childhood epilepsy. Although these phytocannabinoids have anticonvulsant potential and could be lead compounds for drug development programmes, several liabilities would need to be overcome before CBD is superseded by another in this class.
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Affiliation(s)
- L L Anderson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - M Heblinski
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - N L Absalom
- School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - N A Hawkins
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - M Bowen
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,School of Psychology, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - M J Benson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,School of Psychology, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - F Zhang
- School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - D Bahceci
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - P T Doohan
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - M Chebib
- School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - I S McGregor
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.,School of Psychology, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - J A Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - J C Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
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14
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Nuwer JL, Brady ML, Povysheva NV, Coyne A, Jacob TC. Sustained treatment with an α5 GABA A receptor negative allosteric modulator delays excitatory circuit development while maintaining GABAergic neurotransmission. Neuropharmacology 2021; 197:108724. [PMID: 34284042 DOI: 10.1016/j.neuropharm.2021.108724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/01/2021] [Accepted: 07/14/2021] [Indexed: 01/02/2023]
Abstract
α5 subunit GABA type A receptor (GABAAR) preferring negative allosteric modulators (NAMs) are cognitive enhancers with antidepressant-like effects. α5-NAM success in treating mouse models of neurodevelopmental disorders with excessive inhibition have led to Phase 2 clinical trials for Down syndrome. Despite in vivo efficacy, no study has examined the effects of continued α5-NAM treatment on inhibitory and excitatory synapse plasticity to identify mechanisms of action. Here we used L-655,708, an imidazobenzodiazepine that acts as a highly selective but weak α5-NAM, to investigate the impact of sustained treatment on hippocampal neuron synapse and dendrite development. We show that 2-day pharmacological reduction of α5-GABAAR signaling from DIV12-14, when GABAARs contribute to depolarization, delays dendritic spine maturation and the NMDA receptor (NMDAR) GluN2B/GluN2A developmental shift. In contrast, α5-NAM treatment from DIV19-21, when hyperpolarizing GABAAR signaling predominates, enhances surface synaptic GluN2A while decreasing GluN2B. Despite changes in NMDAR subtype surface levels and localization, total levels of key excitatory synapse proteins were largely unchanged, and mEPSCs were unaltered. Importantly, 2-day α5-NAM treatment does not alter the total surface levels or distribution of α5-GABAARs, reduce the gephyrin inhibitory synaptic scaffold, or impair phasic or tonic inhibition. Furthermore, α5-NAM inhibition of the GABAAR tonic current in mature neurons is maintained after 2-day α5-NAM treatment, suggesting reduced tolerance liability, in contrast to other clinically relevant GABAAR-targeting drugs such as benzodiazepines. Together, these results show that α5-GABAARs contribute to dendritic spine maturation and excitatory synapse development via a NMDAR dependent mechanism without perturbing overall neuronal excitability.
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Affiliation(s)
- Jessica L Nuwer
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Megan L Brady
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Nadya V Povysheva
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Amanda Coyne
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Tija C Jacob
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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15
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Regulation of GABA A Receptors Induced by the Activation of L-Type Voltage-Gated Calcium Channels. MEMBRANES 2021; 11:membranes11070486. [PMID: 34209589 PMCID: PMC8304739 DOI: 10.3390/membranes11070486] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/23/2021] [Accepted: 06/25/2021] [Indexed: 12/30/2022]
Abstract
GABAA receptors are pentameric ion channels that mediate most synaptic and tonic extrasynaptic inhibitory transmissions in the central nervous system. There are multiple GABAA receptor subtypes constructed from 19 different subunits in mammals that exhibit different regional and subcellular distributions and distinct pharmacological properties. Dysfunctional alterations of GABAA receptors are associated with various neuropsychiatric disorders. Short- and long-term plastic changes in GABAA receptors can be induced by the activation of different intracellular signaling pathways that are triggered, under physiological and pathological conditions, by calcium entering through voltage-gated calcium channels. This review discusses several mechanisms of regulation of GABAA receptor function that result from the activation of L-type voltage gated calcium channels. Calcium influx via these channels activates different signaling cascades that lead to changes in GABAA receptor transcription, phosphorylation, trafficking, and synaptic clustering, thus regulating the inhibitory synaptic strength. These plastic mechanisms regulate the interplay of synaptic excitation and inhibition that is crucial for the normal function of neuronal circuits.
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16
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Morgan AJ, Davis LC, Galione A. Choreographing endo-lysosomal Ca 2+ throughout the life of a phagosome. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119040. [PMID: 33872669 DOI: 10.1016/j.bbamcr.2021.119040] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/05/2021] [Accepted: 04/07/2021] [Indexed: 12/20/2022]
Abstract
The emergence of endo-lysosomes as ubiquitous Ca2+ stores with their unique cohort of channels has resulted in their being implicated in a growing number of processes in an ever-increasing number of cell types. The architectural and regulatory constraints of these acidic Ca2+ stores distinguishes them from other larger Ca2+ sources such as the ER and influx across the plasma membrane. In view of recent advances in the understanding of the modes of operation, we discuss phagocytosis as a template for how endo-lysosomal Ca2+ signals (generated via TPC and TRPML channels) can be integrated in multiple sophisticated ways into biological processes. Phagocytosis illustrates how different endo-lysosomal Ca2+ signals drive different phases of a process, and how these can be altered by disease or infection.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Park, Oxford OX1 3QT, UK.
| | - Lianne C Davis
- Department of Pharmacology, University of Oxford, Mansfield Park, Oxford OX1 3QT, UK
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Park, Oxford OX1 3QT, UK.
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17
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Field M, Dorovykh V, Thomas P, Smart TG. Physiological role for GABA A receptor desensitization in the induction of long-term potentiation at inhibitory synapses. Nat Commun 2021; 12:2112. [PMID: 33837214 PMCID: PMC8035410 DOI: 10.1038/s41467-021-22420-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/03/2021] [Indexed: 01/03/2023] Open
Abstract
GABAA receptors (GABAARs) are pentameric ligand-gated ion channels distributed throughout the brain where they mediate synaptic and tonic inhibition. Following activation, these receptors undergo desensitization which involves entry into long-lived agonist-bound closed states. Although the kinetic effects of this state are recognised and its structural basis has been uncovered, the physiological impact of desensitization on inhibitory neurotransmission remains unknown. Here we describe an enduring form of long-term potentiation at inhibitory synapses that elevates synaptic current amplitude for 24 h following desensitization of GABAARs in response to agonist exposure or allosteric modulation. Using receptor mutants and allosteric modulators we demonstrate that desensitization of GABAARs facilitates their phosphorylation by PKC, which increases the number of receptors at inhibitory synapses. These observations provide a physiological relevance to the desensitized state of GABAARs, acting as a signal to regulate the efficacy of inhibitory synapses during prolonged periods of inhibitory neurotransmission.
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Affiliation(s)
- Martin Field
- Department of Neuroscience, Physiology and Pharmacology, UCL, London, UK
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Valentina Dorovykh
- Department of Neuroscience, Physiology and Pharmacology, UCL, London, UK
| | - Philip Thomas
- Department of Neuroscience, Physiology and Pharmacology, UCL, London, UK
| | - Trevor G Smart
- Department of Neuroscience, Physiology and Pharmacology, UCL, London, UK.
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18
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Kim HY, Suh PG, Kim JI. The Role of Phospholipase C in GABAergic Inhibition and Its Relevance to Epilepsy. Int J Mol Sci 2021; 22:ijms22063149. [PMID: 33808762 PMCID: PMC8003358 DOI: 10.3390/ijms22063149] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 03/02/2021] [Accepted: 03/17/2021] [Indexed: 12/13/2022] Open
Abstract
Epilepsy is characterized by recurrent seizures due to abnormal hyperexcitation of neurons. Recent studies have suggested that the imbalance of excitation and inhibition (E/I) in the central nervous system is closely implicated in the etiology of epilepsy. In the brain, GABA is a major inhibitory neurotransmitter and plays a pivotal role in maintaining E/I balance. As such, altered GABAergic inhibition can lead to severe E/I imbalance, consequently resulting in excessive and hypersynchronous neuronal activity as in epilepsy. Phospholipase C (PLC) is a key enzyme in the intracellular signaling pathway and regulates various neuronal functions including neuronal development, synaptic transmission, and plasticity in the brain. Accumulating evidence suggests that neuronal PLC is critically involved in multiple aspects of GABAergic functions. Therefore, a better understanding of mechanisms by which neuronal PLC regulates GABAergic inhibition is necessary for revealing an unrecognized linkage between PLC and epilepsy and developing more effective treatments for epilepsy. Here we review the function of PLC in GABAergic inhibition in the brain and discuss a pathophysiological relationship between PLC and epilepsy.
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Affiliation(s)
- Hye Yun Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea; (H.Y.K.); (P.-G.S.)
| | - Pann-Ghill Suh
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea; (H.Y.K.); (P.-G.S.)
- Korea Brain Research Institute (KBRI), Daegu 41062, Korea
| | - Jae-Ick Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea; (H.Y.K.); (P.-G.S.)
- Correspondence: ; Tel.: +82-52-217-2458
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19
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Markin PA, Brito A, Moskaleva NE, Tagliaro F, Tarasov VV, La Frano MR, Savitskii MV, Appolonova SA. Short- and medium-term exposures of diazepam induce metabolomic alterations associated with the serotonergic, dopaminergic, adrenergic and aspartic acid neurotransmitter systems in zebrafish (Danio rerio) embryos/larvae. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2021; 38:100816. [PMID: 33610025 DOI: 10.1016/j.cbd.2021.100816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Diazepam is a well-known psychoactive drug widely used worldwide for the treatment of anxiety, seizures, alcohol withdrawal syndrome, muscle spasms, sleeplessness, agitation, and pre/post-operative sedation. It is part of the benzodiazepine family, substances known to primarily act by binding and enhancing gamma-aminobutyric acid (GABAA) receptors. The objective of the present work was to investigate the influence of short and medium-term diazepam exposures on neurotransmitters measured through targeted metabolomics using a zebrafish embryo model. METHODS Short-term (2.5 h) and medium-term (96 h) exposures to diazepam were performed at drug concentrations of 0.8, 1.6, 16, and 160 μg/L. Intervention groups were compared with a vehicle control group. Each group consisted of 20 zebrafish eggs/larvae. Metabolites related with neurotransmission were determined by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). RESULTS Thirty-six compounds were quantified. Significantly increased tryptophan and serotonin concentrations were found in the intervention groups receiving higher doses of diazepam in 2.5 h exposure (p < 0.05 control versus intervention groups). Tyrosine concentrations were higher (p < 0.05) at higher concentrations in 2.5 h exposure, but lower (p < 0.05) at higher concentrations in 96 h exposure. Both phenylalanine and aspartic acid concentrations were higher (p < 0.05) at higher doses in 2.5 h and 96 h exposure. CONCLUSIONS Short- and medium-term exposures to diazepam induce dose- and time-dependent metabolomic alterations associated with the serotonergic, dopaminergic/adrenergic, and aspartic acid neurotransmitter systems in zebrafish.
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Affiliation(s)
- Pavel A Markin
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia; PhD Program in Nanosciences and Advanced Technologies, University of Verona, Verona, Italy; I.M. Sechenov First Moscow State Medical University, Russia
| | - Alex Brito
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Natalia E Moskaleva
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia; World-Class Research Center "Digital Biodesign and Personalized Healthcare", I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Franco Tagliaro
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia; Unit of Forensic Medicine, Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | | | - Michael R La Frano
- Department of Food Science and Nutrition, California Polytechnic State University, San Luis Obispo, CA, USA; Cal Poly Metabolomics Service Center, California Polytechnic State University, San Luis Obispo, CA, USA
| | - Mark V Savitskii
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia; I.M. Sechenov First Moscow State Medical University, Russia
| | - Svetlana A Appolonova
- Laboratory of Pharmacokinetics and Metabolomic Analysis, Institute of Translational Medicine and Biotechnology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia.
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20
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Castellano D, Shepard RD, Lu W. Looking for Novelty in an "Old" Receptor: Recent Advances Toward Our Understanding of GABA ARs and Their Implications in Receptor Pharmacology. Front Neurosci 2021; 14:616298. [PMID: 33519367 PMCID: PMC7841293 DOI: 10.3389/fnins.2020.616298] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 12/14/2020] [Indexed: 12/16/2022] Open
Abstract
Diverse populations of GABAA receptors (GABAARs) throughout the brain mediate fast inhibitory transmission and are modulated by various endogenous ligands and therapeutic drugs. Deficits in GABAAR signaling underlie the pathophysiology behind neurological and neuropsychiatric disorders such as epilepsy, anxiety, and depression. Pharmacological intervention for these disorders relies on several drug classes that target GABAARs, such as benzodiazepines and more recently neurosteroids. It has been widely demonstrated that subunit composition and receptor stoichiometry impact the biophysical and pharmacological properties of GABAARs. However, current GABAAR-targeting drugs have limited subunit selectivity and produce their therapeutic effects concomitantly with undesired side effects. Therefore, there is still a need to develop more selective GABAAR pharmaceuticals, as well as evaluate the potential for developing next-generation drugs that can target accessory proteins associated with native GABAARs. In this review, we briefly discuss the effects of benzodiazepines and neurosteroids on GABAARs, their use as therapeutics, and some of the pitfalls associated with their adverse side effects. We also discuss recent advances toward understanding the structure, function, and pharmacology of GABAARs with a focus on benzodiazepines and neurosteroids, as well as newly identified transmembrane proteins that modulate GABAARs.
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Affiliation(s)
- David Castellano
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Ryan David Shepard
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Wei Lu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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21
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Mahmoodkhani M, Ghasemi M, Derafshpour L, Amini M, Mehranfard N. Long-Term Decreases in the Expression of Calcineurin and GABAA Receptors Induced by Early Maternal Separation Are Associated with Increased Anxiety-Like Behavior in Adult Male Rats. Dev Neurosci 2020; 42:135-144. [PMID: 33341802 DOI: 10.1159/000512221] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/09/2020] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION Early life stress is a well-described risk factor of anxiety disorders in adulthood. Dysfunction in GABA/glutamate receptors and their functional regulator, calcineurin, is linked to anxiety disorders. Here, we investigated the effect of early life stress, such as repeated maternal separation (MS; 3 h per day from postnatal day [P] 2 to 11), on changes in the expression of calcineurin as well as the ionotropic glutamatergic and GABAergic receptors including α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), N-methyl-D-aspartate (NMDA) and GABAA receptors in the hippocampus and prefrontal cortex (PFC) of adolescent (P35) and adult (P62) male Wistar rats and their correlations with anxiety-like behavior in adulthood. METHODS The protein levels were assessed by Western blot analysis. Anxiety-like behavior was measured in the elevated plus maze (EPM) and open field (OF) tests. RESULTS MS induced a regional transient decrease of glutamate receptors expression at P35, with decreased NMDA and AMPA receptor levels, respectively, in the hippocampus and PFC, suggesting a possible decrease in excitatory synaptic strength. In contrast to glutamate receptors, MS had long-lasting influence on GABAA receptor and calcineurin levels, with reduced expression of GABAA receptor and calcineurin in both brain regions at P35 that continued into adulthood. These results were accompanied by increased anxiety behavior in adulthood, shown by lower percentage of number of total entries and time spent in the open arms of the EPM, and by lower time spent and number of entries in the OF central area. CONCLUSIONS Together, our study suggests that GABAA receptors via calcineurin-dependent signaling pathways may play an important role in the expression of stress-induced anxiety-like behavior.
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Affiliation(s)
- Maryam Mahmoodkhani
- Neurophysiology Research Center, Cellular and Molecular Medicine Institute, Urmia University of Medical Sciences, Urmia, Iran
| | - Maedeh Ghasemi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Leila Derafshpour
- Neurophysiology Research Center, Cellular and Molecular Medicine Institute, Urmia University of Medical Sciences, Urmia, Iran
| | - Mohammad Amini
- Neurophysiology Research Center, Cellular and Molecular Medicine Institute, Urmia University of Medical Sciences, Urmia, Iran
| | - Nasrin Mehranfard
- Neurophysiology Research Center, Cellular and Molecular Medicine Institute, Urmia University of Medical Sciences, Urmia, Iran,
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22
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Sun Y, He Y, Yang L, Liang D, Shi W, Zhu X, Jiang Y, Ou C. Manganese induced nervous injury by α-synuclein accumulation via ATP-sensitive K(+) channels and GABA receptors. Toxicol Lett 2020; 332:164-170. [PMID: 32659473 DOI: 10.1016/j.toxlet.2020.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 06/27/2020] [Accepted: 07/06/2020] [Indexed: 02/06/2023]
Abstract
Manganese (Mn) is an environmental pollutant having a toxic effect on Parkinson's disease, with significant damage seen in the neurons of basal ganglia. Hence, Mn pollution is a public health concern. A Sprague-Dawley rat model was used to determine the damage to basal nuclei, and the effect of Mn intake was detected using the Morris water maze test and transmission electron microscopy. The SH-SY5Y cell line was exposed to Mn, and downstream signaling was assessed to determine the mechanism of toxicity. Mn exposure injured neurons, repressing GABAAR receptors and inducing GABABR receptors. The synergistic effect of the GABABR receptor and Kir6.1-SUR1 or Kir6.2-SUR1 was found to be one of the potential factors for the secretion of α-synuclein. The accumulation of α-synuclein regulated downstream factors calmodulin (CAM) cAMP response element-binding protein (CREB), thereby impairing learning and memory. Other genes downstream of CREB, rather than the feedback regulation of CREB, and brain-derived neurotrophic factor might also be involved.
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Affiliation(s)
- Yi Sun
- Department of Toxicology, School of Public Health, Guilin Medical University, Guilin 541004, China
| | - Yonghua He
- Department of Toxicology, School of Public Health, Guilin Medical University, Guilin 541004, China
| | - Lin Yang
- Department of Toxicology, School of Public Health, Guilin Medical University, Guilin 541004, China
| | - Dan Liang
- Department of Toxicology, School of Public Health, Guilin Medical University, Guilin 541004, China
| | - Wenxiang Shi
- Department of Toxicology, School of Public Health, Guilin Medical University, Guilin 541004, China
| | - Xiaonian Zhu
- Department of Toxicology, School of Public Health, Guilin Medical University, Guilin 541004, China
| | - Yueming Jiang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Naning 530021, China
| | - Chaoyan Ou
- Department of Toxicology, School of Public Health, Guilin Medical University, Guilin 541004, China.
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Sarkar S, Choudhury S, Islam N, Chowdhury MSJH, Chowdhury MTI, Baker MR, Baker SN, Kumar H. Effects of Diazepam on Reaction Times to Stop and Go. Front Hum Neurosci 2020; 14:567177. [PMID: 33132880 PMCID: PMC7573484 DOI: 10.3389/fnhum.2020.567177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/31/2020] [Indexed: 01/13/2023] Open
Abstract
Introduction: The ability to stop the execution of a movement in response to an external cue requires intact executive function. The effect of psychotropic drugs on movement inhibition is largely unknown. Movement stopping can be estimated by the Stop Signal Reaction Time (SSRT). In a recent publication, we validated an improved measure of SSRT (optimum combination SSRT, ocSSRT). Here we explored how diazepam, which enhances transmission at GABAA receptors, affects ocSSRT. Methods: Nine healthy individuals were randomized to receive placebo, 5 mg or 10 mg doses of diazepam. Each participant received both the dosage of drug and placebo orally on separate days with adequate washout. The ocSSRT and simple reaction time (RT) were estimated through a stop-signal task delivered via a battery-operated box incorporating green (Go) and red (Stop) light-emitting diodes. The task was performed just before and 1 h after dosing. Result: The mean change in ocSSRT after 10 mg diazepam was significantly higher (+27 ms) than for placebo (−1 ms; p = 0.012). By contrast, the mean change in simple response time remained comparable in all three dosing groups (p = 0.419). Conclusion: Our results confirm that a single therapeutic adult dose of diazepam can alter motor inhibition in drug naïve healthy individuals. The selective effect of diazepam on ocSSRT but not simple RT suggests that GABAergic neurons may play a critical role in movement-stopping.
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Affiliation(s)
- Swagata Sarkar
- Department of Neurology, Institute of Neurosciences Kolkata, Kolkata, India.,Department of Physiology, University of Calcutta, Kolkata, India
| | - Supriyo Choudhury
- Department of Neurology, Institute of Neurosciences Kolkata, Kolkata, India
| | - Nazrul Islam
- Department of Neurology, National Institute of Neurosciences and Hospital, Dhaka, Bangladesh
| | | | | | - Mark R Baker
- Department of Neurology, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom.,Department of Clinical Neurophysiology, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom.,The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Stuart N Baker
- The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Hrishikesh Kumar
- Department of Neurology, Institute of Neurosciences Kolkata, Kolkata, India
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Gray JC, Murphy M, Leggio L. Leveraging genetic data to investigate molecular targets and drug repurposing candidates for treating alcohol use disorder and hepatotoxicity. Drug Alcohol Depend 2020; 214:108155. [PMID: 32652377 PMCID: PMC7423741 DOI: 10.1016/j.drugalcdep.2020.108155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/03/2020] [Accepted: 06/24/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Novel treatments for alcohol use disorder (AUD) and alcohol-related liver disease (ALD) are greatly needed. Genetic information can improve drug discovery rates by facilitating the identification of novel biological targets and potential drugs for repurposing. METHODS The present study utilized a recently developed Bayesian approach, Integrative Risk Gene Selector (iRIGS), to identify additional risk genes for alcohol consumption using SNPs from the largest alcohol consumption GWAS to date (N = 941,280). iRIGS incorporates several genomic features and closeness of these genes in network space to compute a posterior probability for protein coding genes near each SNP. We subsequently used the Target Central Resource Database to search for drug-protein interactions for these newly identified genes and previously identified risk genes for alcohol consumption. RESULTS We identified several genes that are novel contributions to the previously published alcohol consumption GWAS. Namely, ACVR2A, which is critical for liver function and linked to anxiety and cocaine self-administration, and PRKCE, which has been linked to alcohol self-administration. Notably, only a minority of the SNPs (18.4 %) were linked to genes with confidence (>0.75), underscoring the need to apply multiple methods to assign function to loci. Finally, some previously identified risk genes for alcohol consumption code for proteins that are implicated in liver function and are targeted by drugs, some of which are candidates for managing hepatotoxicity. CONCLUSIONS This study demonstrates the value of incorporating regulatory information and drug-protein interaction data to highlight additional molecular targets and drug repurposing candidates for treating AUD and ALD.
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Affiliation(s)
- Joshua C. Gray
- Department of Medical and Clinical Psychology, Uniformed Services University, 4301 Jones Bridge Rd, Bethesda, MD 20814,Correspondence to Joshua Charles Gray, PhD; (410) 707-1180, , 4301 Jones Bridge Rd, Bethesda, MD 20814
| | - Mikela Murphy
- Department of Medical and Clinical Psychology, Uniformed Services University, 4301 Jones Bridge Rd, Bethesda, MD 20814
| | - Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research and National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Bethesda, MD; Medication Development Program, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD; Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, RI
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25
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The role of hippocampal GABA A receptors on anxiolytic effects of Echium amoenum extract in a mice model of restraint stress. Mol Biol Rep 2020; 47:6487-6496. [PMID: 32778988 DOI: 10.1007/s11033-020-05699-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 07/26/2020] [Indexed: 01/01/2023]
Abstract
Echium amoenum (EA), a popular medicinal plant in Persian medicine, has anxiolytic, antioxidant, sedative, and anti-inflammatory effects. This study examined whether GABA-ergic signaling is involved in the anxiolytic effects of EA in mice. Sixty BALB/c mice (25-30 g) were divided into six groups (n = 10) as follows: the (I) control group received 10 ml/kg normal saline (NS). In the stress groups, the animals underwent 14 consecutive days of restraint stress (RS), and received following treatments simultaneously; (II) RS + NS; (III) RS + Diaz (Diazepam); (IV) RS + EA; (V) RS + Flu (Flumazenil) + EA; (VI) RS + Flu + Diaz. Behavioral tests including the open field test (OFT) and elevated plus maze (EPM) were performed to evaluate anxiety-like behaviors and the effects of the regimens. The plasma level of corticosterone and the hippocampal protein expressions of IL-1β, TNF-α, CREB, and BDNF, as well as p-GABAA/GABAA ratio, were also assessed. The findings revealed that chronic administration of EA alone produced anxiolytic effects in both behavioral tests, while diazepam alone or in combination with Flu failed to decrease the anxiety-like behaviors. Furthermore, the p-GABAA/GABAA and p-CREB/CREB ratios, and protein levels of BDNF were significantly increased in the EA-received group. On the other hand, plasma corticosterone levels and the hippocampal IL-1β and TNF-α levels were significantly decreased by EA. However, pre-treatment with GABAA receptors (GABAA Rs) antagonist, Flu, reversed the anxiolytic and molecular effects of EA in the RS-subjected animals. Our findings confirmed that alternation of GABAAR is involved in the effects of EA against RS-induced anxiety-like behaviors, HPA axis activation, and neuroinflammation.
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26
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The adenosine A1 receptor agonist WAG 994 suppresses acute kainic acid-induced status epilepticus in vivo. Neuropharmacology 2020; 176:108213. [PMID: 32615188 DOI: 10.1016/j.neuropharm.2020.108213] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/10/2020] [Accepted: 06/12/2020] [Indexed: 12/22/2022]
Abstract
Status epilepticus (SE) is a neurological emergency characterized by continuous seizure activity lasting longer than 5 min, often with no recovery between seizures (Trinka et al., 2015). SE is refractory to benzodiazepine and second-line treatments in about 30% cases. Novel treatment approaches are urgently needed as refractory SE is associated with mortality rates of up to 70%. Robust adenosinergic anticonvulsant effects have been known for decades, but translation into seizure treatments was hampered by cardiovascular side effects. However, the selective adenosine A1 receptor agonist SDZ WAG 994 (WAG) displays diminished cardiovascular side effects compared to classic A1R agonists and was safely administered systemically in human clinical trials. Here, we investigate the anticonvulsant efficacy of WAG in vitro and in vivo. WAG robustly inhibited high-K+-induced continuous epileptiform activity in rat hippocampal slices (IC50 = 52.5 nM). Importantly, WAG acutely suppressed SE in vivo induced by kainic acid (20 mg/kg i.p.) in mice. After SE was established, mice received three i.p. injections of WAG or diazepam (DIA, 5 mg/kg). Interestingly, DIA did not attenuate SE while the majority of WAG-treated mice (1 mg/kg) were seizure-free after three injections. Anticonvulsant effects were retained when a lower dose of WAG (0.3 mg/kg) was used. Importantly, all WAG-treated mice survived kainic acid induced SE. In summary, we report for the first time that an A1R agonist with an acceptable human side-effect profile can acutely suppress established SE in vivo. Our results suggest that WAG stops or vastly attenuates SE while DIA fails to mitigate SE in this model.
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Sureshkumar KK, Chopra B. Impact of Donor Ethnicity on Long-Term Kidney Transplant Outcomes: Analysis by Kidney Donor Profile Index Categories. EXP CLIN TRANSPLANT 2020; 18:144-148. [DOI: 10.6002/ect.2018.0394] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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28
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Foitzick MF, Medina NB, Iglesias García LC, Gravielle MC. Benzodiazepine exposure induces transcriptional down-regulation of GABA A receptor α1 subunit gene via L-type voltage-gated calcium channel activation in rat cerebrocortical neurons. Neurosci Lett 2020; 721:134801. [PMID: 32007495 DOI: 10.1016/j.neulet.2020.134801] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/24/2020] [Accepted: 01/30/2020] [Indexed: 01/10/2023]
Abstract
GABAA receptors are targets of different pharmacologically relevant drugs, such as barbiturates, benzodiazepines, and anesthetics. In particular, benzodiazepines are prescribed for the treatment of anxiety, sleep disorders, and seizure disorders. Benzodiazepines potentiate GABA responses by binding to GABAA receptors, which are mainly composed of α (1-3, 5), β2, and γ2 subunits. Prolonged activation of GABAA receptors by endogenous and exogenous modulators induces adaptive changes that lead to tolerance. For example, chronic administration of benzodiazepines produces tolerance to most of their pharmacological actions, limiting their usefulness. The mechanism of benzodiazepine tolerance is still unknown. To investigate the molecular basis of tolerance, we studied the effect of sustained exposure of rat cerebral cortical neurons to diazepam on the GABAA receptor. Flunitrazepam binding experiments showed that diazepam treatment induced uncoupling between GABA and benzodiazepine sites, which was blocked by co-incubation with flumazenil, picrotoxin, or nifedipine. Diazepam also produced selective transcriptional down-regulation of GABAA receptor α1 subunit gene through a mechanism dependent on the activation of L-type voltage-gated calcium channels. These findings suggest benzodiazepine-induced stimulation of calcium influx through L-type voltage-gated calcium channels triggers the activation of a signaling pathway that leads to uncoupling and an alteration of receptor subunit expression. Insights into the mechanism of benzodiazepine tolerance will contribute to the design of new drugs that can maintain their efficacies after long-term treatments.
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Affiliation(s)
- María Florencia Foitzick
- Instituto de Investigaciones Farmacológicas (ININFA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. CONICET, Buenos Aires, Argentina
| | - Nelsy Beatriz Medina
- Instituto de Investigaciones Farmacológicas (ININFA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. CONICET, Buenos Aires, Argentina
| | - Lucía Candela Iglesias García
- Instituto de Investigaciones Farmacológicas (ININFA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. CONICET, Buenos Aires, Argentina
| | - María Clara Gravielle
- Instituto de Investigaciones Farmacológicas (ININFA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. CONICET, Buenos Aires, Argentina.
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29
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Kang Y, Saito M, Toyoda H. Molecular and Regulatory Mechanisms of Desensitization and Resensitization of GABA A Receptors with a Special Reference to Propofol/Barbiturate. Int J Mol Sci 2020; 21:ijms21020563. [PMID: 31952324 PMCID: PMC7014398 DOI: 10.3390/ijms21020563] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/11/2020] [Accepted: 01/14/2020] [Indexed: 11/16/2022] Open
Abstract
It is known that desensitization of GABAA receptor (GABAAR)-mediated currents is paradoxically correlated with the slowdown of their deactivation, i.e., resensitization. It has been shown that an upregulation of calcineurin enhances the desensitization of GABAAR-mediated currents but paradoxically prolongs the decay phase of inhibitory postsynaptic currents/potentials without appreciable diminution of their amplitudes. The paradoxical correlation between desensitization and resensitization of GABAAR-mediated currents can be more clearly seen in response to a prolonged application of GABA to allow more desensitization, instead of brief pulse used in previous studies. Indeed, hump-like GABAAR currents were produced after a strong desensitization at the offset of a prolonged puff application of GABA in pyramidal cells of the barrel cortex, in which calcineurin activity was enhanced by deleting phospholipase C-related catalytically inactive proteins to enhance the desensitization/resensitization of GABAAR-mediated currents. Hump-like GABAAR currents were also evoked at the offset of propofol or barbiturate applications in hippocampal or sensory neurons, but not GABA applications. Propofol and barbiturate are useful to treat benzodiazepine/alcohol withdrawal syndrome, suggesting that regulatory mechanisms of desensitization/resensitization of GABAAR-mediated currents are important in understanding benzodiazepine/alcohol withdrawal syndrome. In this review, we will discuss the molecular and regulatory mechanisms underlying the desensitization and resensitization of GABAAR-mediated currents and their functional significances.
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Affiliation(s)
- Youngnam Kang
- Department of Behavioral Physiology, Graduate School of Human Sciences, Osaka University, Osaka 565-0871, Japan
- Department of Neurobiology and Physiology, School of Dentistry, Seoul National University, Seoul 110-749, Korea
- Correspondence: (Y.K.); (H.T.)
| | - Mitsuru Saito
- Department of Oral Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Sakuragaoka 8-35-1, Kagoshima 890-8544, Japan;
| | - Hiroki Toyoda
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Osaka 565-0871, Japan
- Correspondence: (Y.K.); (H.T.)
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Khayenko V, Maric HM. Targeting GABA AR-Associated Proteins: New Modulators, Labels and Concepts. Front Mol Neurosci 2019; 12:162. [PMID: 31293385 PMCID: PMC6606717 DOI: 10.3389/fnmol.2019.00162] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 06/12/2019] [Indexed: 12/21/2022] Open
Abstract
γ-aminobutyric acid type A receptors (GABAARs) are the major mediators of synaptic inhibition in the brain. Aberrant GABAAR activity or regulation is observed in various neurodevelopmental disorders, neurodegenerative diseases and mental illnesses, including epilepsy, Alzheimer’s and schizophrenia. Benzodiazepines, anesthetics and other pharmaceutics targeting these receptors find broad clinical use, but their inherent lack of receptor subtype specificity causes unavoidable side effects, raising a need for new or adjuvant medications. In this review article, we introduce a new strategy to modulate GABAeric signaling: targeting the intracellular protein interactors of GABAARs. Of special interest are scaffolding, anchoring and supporting proteins that display high GABAAR subtype specificity. Recent efforts to target gephyrin, the major intracellular integrator of GABAergic signaling, confirm that GABAAR-associated proteins can be successfully targeted through diverse molecules, including recombinant proteins, intrabodies, peptide-based probes and small molecules. Small-molecule artemisinins and peptides derived from endogenous interactors, that specifically target the universal receptor binding site of gephyrin, acutely affect synaptic GABAAR numbers and clustering, modifying neuronal transmission. Interference with GABAAR trafficking provides another way to modulate inhibitory signaling. Peptides blocking the binding site of GABAAR to AP2 increase the surface concentration of GABAAR clusters and enhance GABAergic signaling. Engineering of gephyrin binding peptides delivered superior means to interrogate neuronal structure and function. Fluorescent peptides, designed from gephyrin binders, enable live neuronal staining and visualization of gephyrin in the post synaptic sites with submicron resolution. We anticipate that in the future, novel fluorescent probes, with improved size and binding efficiency, may find wide application in super resolution microscopy studies, enlightening the nanoscale architecture of the inhibitory synapse. Broader studies on GABAAR accessory proteins and the identification of the exact molecular binding interfaces and affinities will advance the development of novel GABAAR modulators and following in vivo studies will reveal their clinical potential as adjuvant or stand-alone drugs.
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Affiliation(s)
- Vladimir Khayenko
- Institute of Structural Biology, Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany.,Department of Biotechnology and Biophysics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Hans Michael Maric
- Institute of Structural Biology, Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany.,Department of Biotechnology and Biophysics, Biocenter, University of Würzburg, Würzburg, Germany
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31
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Lüscher B, Möhler H. Brexanolone, a neurosteroid antidepressant, vindicates the GABAergic deficit hypothesis of depression and may foster resilience. F1000Res 2019; 8. [PMID: 31275559 PMCID: PMC6544078 DOI: 10.12688/f1000research.18758.1] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/22/2019] [Indexed: 12/18/2022] Open
Abstract
The GABAergic deficit hypothesis of depression states that a deficit of GABAergic transmission in defined neural circuits is causal for depression. Conversely, an enhancement of GABA transmission, including that triggered by selective serotonin reuptake inhibitors or ketamine, has antidepressant effects. Brexanolone, an intravenous formulation of the endogenous neurosteroid allopregnanolone, showed clinically significant antidepressant activity in postpartum depression. By allosterically enhancing GABA
A receptor function, the antidepressant activity of allopregnanolone is attributed to an increase in GABAergic inhibition. In addition, allopregnanolone may stabilize normal mood by decreasing the activity of stress-responsive dentate granule cells and thereby sustain resilience behavior. Therefore, allopregnanolone may augment and extend its antidepressant activity by fostering resilience. The recent structural resolution of the neurosteroid binding domain of GABA
A receptors will expedite the development of more selective ligands as a potential new class of central nervous system drugs.
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Affiliation(s)
- Bernhard Lüscher
- Department of Biology and Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, 16802, USA.,Center for Molecular Investigation of Neurological Disorders, The Huck Institutes for the Life Sciences, Pennsylvania State University, University Park, PA, 16802, USA
| | - Hanns Möhler
- Institute of Pharmacology and Neuroscience Center, University of Zurich, Zurich, 8057, Switzerland.,Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology (ETH), Zurich, 8057, Switzerland
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Brus O, Cao Y, Hammar Å, Landén M, Lundberg J, Nordanskog P, Nordenskjöld A. Lithium for suicide and readmission prevention after electroconvulsive therapy for unipolar depression: population-based register study. BJPsych Open 2019; 5:e46. [PMID: 31189487 PMCID: PMC6582214 DOI: 10.1192/bjo.2019.37] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Electroconvulsive therapy (ECT) is effective for unipolar depression but relapse and suicide are significant challenges. Lithium could potentially lower these risks, but is used only in a minority of patients.AimsThis study quantifies the effect of lithium on risk of suicide and readmission and identifies factors that are associate with readmission and suicide. METHOD This population-based register study used data from the Swedish National Quality Register for ECT and other Swedish national registers. Patients who have received ECT for unipolar depression as in-patients between 2011 and 2016 were followed until death, readmission to hospital or the termination of the study at the end of 2016. Cox regression was used to estimate hazard ratios (HR) of readmission and suicide in adjusted models. RESULTS Out of 7350 patients, 56 died by suicide and 4203 were readmitted. Lithium was prescribed to 638 (9%) patients. Mean follow-up was 1.4 years. Lithium was significantly associated with lower risk of suicide (P = 0.014) and readmission (HR 0.84 95% CI 0.75-0.93). The number needed to be treated with lithium to prevent one readmission was 16. In addition, the following factors were statistically associated with suicide: male gender, being a widow, substance use disorder and a history of suicide attempts. Readmission was associated with young age, being divorced or unemployed, comorbid anxiety disorder, nonpsychotic depression, more severe symptoms before ECT, no improvement with ECT, not receiving continuation ECT or antidepressants, usage of antipsychotics, anxiolytics or benzodiazepines, severity of medication resistance and number of previous admissions. CONCLUSIONS More patients could benefit from lithium treatment.Declaration of interestNone.
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Affiliation(s)
- Ole Brus
- Statistician, Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health, Örebro University, Sweden
| | - Yang Cao
- Statistician, Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health, Örebro University; and Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Sweden
| | - Åsa Hammar
- Professor, Department of Biological and Medical Psychology, University of Bergen; and Division of Psychiatry, Haukeland University Hospital, Norway
| | - Mikael Landén
- Professor, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at Gothenburg University; and Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Sweden
| | - Johan Lundberg
- Physician and Associate Professor, Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet; and Stockholm County Council, Sweden
| | - Pia Nordanskog
- Physician, Center for Social and Affective Neuroscience, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University; and Department of Psychiatry, Region Östergötland, Sweden
| | - Axel Nordenskjöld
- Physician, University Health Care Research Centre, Faculty of Health and Medical Sciences, Örebro University, Sweden
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Lorenz-Guertin JM, Bambino MJ, Das S, Weintraub ST, Jacob TC. Diazepam Accelerates GABA AR Synaptic Exchange and Alters Intracellular Trafficking. Front Cell Neurosci 2019; 13:163. [PMID: 31080408 PMCID: PMC6497791 DOI: 10.3389/fncel.2019.00163] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/08/2019] [Indexed: 12/21/2022] Open
Abstract
Despite 50+ years of clinical use as anxiolytics, anti-convulsants, and sedative/hypnotic agents, the mechanisms underlying benzodiazepine (BZD) tolerance are poorly understood. BZDs potentiate the actions of gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the adult brain, through positive allosteric modulation of γ2 subunit containing GABA type A receptors (GABAARs). Here we define key molecular events impacting γ2 GABAAR and the inhibitory synapse gephyrin scaffold following initial sustained BZD exposure in vitro and in vivo. Using immunofluorescence and biochemical experiments, we found that cultured cortical neurons treated with the classical BZD, diazepam (DZP), presented no substantial change in surface or synaptic levels of γ2-GABAARs. In contrast, both γ2 and the postsynaptic scaffolding protein gephyrin showed diminished total protein levels following a single DZP treatment in vitro and in mouse cortical tissue. We further identified DZP treatment enhanced phosphorylation of gephyrin Ser270 and increased generation of gephyrin cleavage products. Selective immunoprecipitation of γ2 from cultured neurons revealed enhanced ubiquitination of this subunit following DZP exposure. To assess novel trafficking responses induced by DZP, we employed a γ2 subunit containing an N terminal fluorogen-activating peptide (FAP) and pH-sensitive green fluorescent protein (γ2pHFAP). Live-imaging experiments using γ2pHFAP GABAAR expressing neurons identified enhanced lysosomal targeting of surface GABAARs and increased overall accumulation in vesicular compartments in response to DZP. Using fluorescence resonance energy transfer (FRET) measurements between α2 and γ2 subunits within a GABAAR in neurons, we identified reductions in synaptic clusters of this subpopulation of surface BZD sensitive receptor. Additional time-series experiments revealed the gephyrin regulating kinase ERK was inactivated by DZP at multiple time points. Moreover, we found DZP simultaneously enhanced synaptic exchange of both γ2-GABAARs and gephyrin using fluorescence recovery after photobleaching (FRAP) techniques. Finally we provide the first proteomic analysis of the BZD sensitive GABAAR interactome in DZP vs. vehicle treated mice. Collectively, our results indicate DZP exposure elicits down-regulation of gephyrin scaffolding and BZD sensitive GABAAR synaptic availability via multiple dynamic trafficking processes.
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Affiliation(s)
- Joshua M. Lorenz-Guertin
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Matthew J. Bambino
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sabyasachi Das
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Susan T. Weintraub
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Tija C. Jacob
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
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Petrache AL, Rajulawalla A, Shi A, Wetzel A, Saito T, Saido TC, Harvey K, Ali AB. Aberrant Excitatory-Inhibitory Synaptic Mechanisms in Entorhinal Cortex Microcircuits During the Pathogenesis of Alzheimer's Disease. Cereb Cortex 2019; 29:1834-1850. [PMID: 30766992 PMCID: PMC6418384 DOI: 10.1093/cercor/bhz016] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/18/2019] [Indexed: 12/24/2022] Open
Abstract
Synaptic dysfunction is widely proposed as an initial insult leading to the neurodegeneration observed in Alzheimer's disease (AD). We hypothesize that the initial insult originates in the lateral entorhinal cortex (LEC) due to deficits in key interneuronal functions and synaptic signaling mechanisms, in particular, Wnt (Wingless/integrated). To investigate this hypothesis, we utilized the first knock-in mouse model of AD (AppNL-F/NL-F), expressing a mutant form of human amyloid-β (Aβ) precursor protein. This model shows an age-dependent accumulation of Aβ, neuroinflammation, and neurodegeneration. Prior to the typical AD pathology, we showed a decrease in canonical Wnt signaling activity first affecting the LEC in combination with synaptic hyperexcitation and severely disrupted excitatory-inhibitory inputs onto principal cells. This synaptic imbalance was consistent with a reduction in the number of parvalbumin-containing (PV) interneurons, and a reduction in the somatic inhibitory axon terminals in the LEC compared with other cortical regions. However, targeting GABAA receptors on PV cells using allosteric modulators, diazepam, zolpidem, or a nonbenzodiazepine, L-838,417 (modulator of α2/3 subunit-containing GABAA receptors), restored the excitatory-inhibitory imbalance observed at principal cells in the LEC. These data support our hypothesis, providing a rationale for targeting the synaptic imbalance in the LEC for early stage therapeutic intervention to prevent neurodegeneration in AD.
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Affiliation(s)
| | | | - Anqi Shi
- UCL School of Pharmacy, University College London, London, UK
| | - Andrea Wetzel
- UCL School of Pharmacy, University College London, London, UK
| | - Takashi Saito
- RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | | | - Kirsten Harvey
- UCL School of Pharmacy, University College London, London, UK
| | - Afia B Ali
- UCL School of Pharmacy, University College London, London, UK
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