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Bundy J, Shaw J, Hammel M, Nguyen J, Robbins C, Mercier I, Suryanarayanan A. Role of β3 subunit of the GABA type A receptor in triple negative breast cancer proliferation, migration, and cell cycle progression. Cell Cycle 2024; 23:448-465. [PMID: 38623967 PMCID: PMC11174043 DOI: 10.1080/15384101.2024.2340912] [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: 09/08/2023] [Accepted: 02/29/2024] [Indexed: 04/17/2024] Open
Abstract
Triple negative breast cancer (TNBC) is known for its heterogeneous nature and aggressive onset. The unresponsiveness to hormone therapies and immunotherapy and the toxicity of chemotherapeutics account for the limited treatment options for TNBC. Ion channels have emerged as possible therapeutic candidates for cancer therapy, but little is known about how ligand gated ion channels, specifically, GABA type A ligand-gated ion channel receptors (GABAAR), affect cancer pathogenesis. Our results show that the GABAA β3 subunit is expressed at higher levels in TNBC cell lines than non-tumorigenic cells, therefore contributing to the idea that limiting the GABAAR via knockdown of the GABAA β3 subunit is a potential strategy for decreasing the proliferation and migration of TNBC cells. We employed pharmacological and genetic approaches to investigate the role of the GABAA β3 subunit in TNBC proliferation, migration, and cell cycle progression. The results suggest that pharmacological antagonism or genetic knockdown of GABAA β3 subunit decreases TNBC proliferation and migration. In addition, GABAA β3 subunit knockdown causes cell cycle arrest in TNBC cell lines via decreased cyclin D1 and increased p21 expression. Our findings suggest that membrane bound GABAA receptors containing the β3 subunit can be further developed as a potential novel target for the treatment of TNBC.
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Affiliation(s)
- J Bundy
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, Saint Joseph’s University, Pharmacology and Toxicology Center (PTC), Philadelphia, PA, USA
| | - J Shaw
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, Saint Joseph’s University, Pharmacology and Toxicology Center (PTC), Philadelphia, PA, USA
| | - M Hammel
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, Saint Joseph’s University, Pharmacology and Toxicology Center (PTC), Philadelphia, PA, USA
| | - J Nguyen
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, Saint Joseph’s University, Pharmacology and Toxicology Center (PTC), Philadelphia, PA, USA
| | - C Robbins
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, Saint Joseph’s University, Pharmacology and Toxicology Center (PTC), Philadelphia, PA, USA
| | - I Mercier
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, Saint Joseph’s University, Pharmacology and Toxicology Center (PTC), Philadelphia, PA, USA
| | - A Suryanarayanan
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, Saint Joseph’s University, Pharmacology and Toxicology Center (PTC), Philadelphia, PA, USA
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Ruiz-Rodríguez VM, Torres-González CA, Salas-Canedo KM, Pecina-Maza NQ, Martínez-Leija ME, Portales-Pérez DP, Estrada-Sánchez AM. Dynamical changes in the expression of GABAergic and purinergic components occur during the polarization of THP-1 monocytes to proinflammatory macrophages. Biochem Biophys Rep 2023; 36:101558. [PMID: 37881409 PMCID: PMC10594599 DOI: 10.1016/j.bbrep.2023.101558] [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: 10/03/2023] [Accepted: 10/11/2023] [Indexed: 10/27/2023] Open
Abstract
The monocytes are key components of innate immunity, as they can differentiate into phagocytic cells or macrophages with proinflammatory or anti-inflammatory phenotypes. The gamma-aminobutyric acid (GABA) and adenosine triphosphate (ATP), two known neurotransmitters, are two environmental signals that contribute to the differentiation of monocytes into macrophages and their subsequent polarization into proinflammatory M1 and anti-inflammatory M2 macrophages. Although monocytes and macrophages express proteins related to GABA and ATP-mediated response (GABAergic and purinergic systems, respectively), it is unknown whether changes in their expression occur during monocyte activation or their differentiation and polarization into macrophages. Therefore, we evaluated the expression levels of GABAergic and purinergic signaling components in the THP-1 monocyte cell line and their changes during monocyte activation, differentiation, and polarization to M1 proinflammatory macrophages. Our results showed that activated monocytes are characterized by increased expression of two GABAergic components, the GABA transporter 2 (GAT-2) and the glutamic acid decarboxylase (GAD)-67, an enzyme involved in GABA synthesis. Also, monocytes showed a pronounced expression of the purinergic receptors P2X4 and P2X7. Interestingly, during differentiation, monocytes increased the expression of the β2 subunit of GABA A-type receptor (GABA-AR), while the purinergic receptors P2X1 and P2X1del were reduced. In contrast, proinflammatory M1 macrophages showed a reduced expression in the α4 subunit of GABA-AR and GAD67, while P2X4 and P2X7 were overexpressed. These results indicate that dynamical changes in the GABAergic and purinergic components occur during the transition from monocytes to macrophages. Since GABA and ATP are two neurotransmitters, our results suggest that monocytes and macrophages respond to neurotransmitter-induced stimulation and may represent a path of interaction between the nervous and immune systems during peripheral inflammation and neuroinflammation development.
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Affiliation(s)
- Victor Manuel Ruiz-Rodríguez
- División de Biología Molecular, Laboratorio de Neurobiología, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, San Luis Potosí, México
| | - Carlos Alberto Torres-González
- División de Biología Molecular, Laboratorio de Neurobiología, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, San Luis Potosí, México
- Translational and Molecular Medicine Laboratory, Research Center for Health Sciences and Biomedicine, Autonomous University of San Luis Potosí, San Luis Potosí, México
| | - Karina Monserrat Salas-Canedo
- División de Biología Molecular, Laboratorio de Neurobiología, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, San Luis Potosí, México
- Translational and Molecular Medicine Laboratory, Research Center for Health Sciences and Biomedicine, Autonomous University of San Luis Potosí, San Luis Potosí, México
| | - Nicole Quibey Pecina-Maza
- División de Biología Molecular, Laboratorio de Neurobiología, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, San Luis Potosí, México
- Translational and Molecular Medicine Laboratory, Research Center for Health Sciences and Biomedicine, Autonomous University of San Luis Potosí, San Luis Potosí, México
| | - Miguel Ernesto Martínez-Leija
- Translational and Molecular Medicine Laboratory, Research Center for Health Sciences and Biomedicine, Autonomous University of San Luis Potosí, San Luis Potosí, México
| | - Diana Patricia Portales-Pérez
- Translational and Molecular Medicine Laboratory, Research Center for Health Sciences and Biomedicine, Autonomous University of San Luis Potosí, San Luis Potosí, México
| | - Ana María Estrada-Sánchez
- División de Biología Molecular, Laboratorio de Neurobiología, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, San Luis Potosí, México
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3
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Jia ZQ, Zhang SG, Wang Y, Pan JH, Liu FF, Zhan EL, Fouad EA, Fu YL, Pan QR, Zhao CQ. Physiological Function of RDL1 and RDL2 Subunits of the Ionotropic GABA Receptor in the Spodoptera litura with the CRISPR/Cas9 System In Vivo. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:11875-11883. [PMID: 37490029 DOI: 10.1021/acs.jafc.3c02811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
In insect ionotropic γ-aminobutyric acid receptor (iGABAR) subunits, only resistance to dieldrin (RDL) can be individually and functionally expressed in vitro. In lepidopteran, two to three RDL subtypes are identified; however, their physiological roles have not been distinguished in vivo. In this study, SlRdl1 and SlRdl2 of S. litura were individually knocked out using CRISPR/Cas9, respectively. The mortality and larval and pupal duration of KOSlRdl1 and KOSlRdl2 were increased. The flight time and distance were increased by 43.30%-80.66% and 58.96%-198.22%, respectively, in KOSlRdl1. The GABA-induced current was significantly decreased by 53.57%-74.28% and 46.91%-63.34% in the ventral nerve cord, and the GABA titer was significantly reduced by 17.65%-28.05% and 19.85%-42.46% in KOSlRdl1 and KOSlRdl2, respectively. In conclusion, SlRdl1 and SlRdl2 are necessary for the transmission of GABA-induced neural signals; however, only SlRdl1 could regulate the flight capability of S. litura. Our results provided a new avenue to study lepidopteran iGABARs.
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Affiliation(s)
- Zhong Qiang Jia
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Su Gui Zhang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Ying Wang
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Jun Heng Pan
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Fei Fan Liu
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - En Ling Zhan
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Eman Atef Fouad
- Department of Bioassay, Central Agricultural Pesticides Laboratory, Agricultural Research Center, 12618 Giza, Egypt
| | - Ya Li Fu
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Qi Rui Pan
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Chun Qing Zhao
- Key Laboratory of Integrated Pest Management on Crops in East China, Ministry of Agriculture, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P.R. China
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Du Y, Li J, Wang M, Tian Q, Pang Y, Wen Y, Wu D, Wang YT, Dong Z. Genetic inhibition of glutamate allosteric potentiation of GABA ARs in mice results in hyperexcitability, leading to neurobehavioral abnormalities. MedComm (Beijing) 2023; 4:e235. [PMID: 37101797 PMCID: PMC10123808 DOI: 10.1002/mco2.235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 04/28/2023] Open
Abstract
The imbalance between neuronal excitation and inhibition (E/I) in neural circuit has been considered to be at the root of numerous brain disorders. We recently reported a novel feedback crosstalk between the excitatory neurotransmitter glutamate and inhibitory γ-aminobutyric acid type A receptor (GABAAR)-glutamate allosteric potentiation of GABAAR functions through a direct binding of glutamate to the GABAAR itself. Here, we investigated the physiological significance and pathological implications of this cross-talk by generating the β3E182G knock-in (KI) mice. We found that β3E182G KI, while had little effect on basal GABAAR-mediated synaptic transmission, significantly reduced glutamate potentiation of GABAAR-mediated responses. These KI mice displayed lower thresholds for noxious stimuli, higher susceptibility to seizures and enhanced hippocampus-related learning and memory. Additionally, the KI mice exhibited impaired social interactions and decreased anxiety-like behaviors. Importantly, hippocampal overexpression of wild-type β3-containing GABAARs was sufficient to rescue the deficits of glutamate potentiation of GABAAR-mediated responses, hippocampus-related behavioral abnormalities of increased epileptic susceptibility, and impaired social interactions. Our data indicate that the novel crosstalk among excitatory glutamate and inhibitory GABAAR functions as a homeostatic mechanism in fine-tuning neuronal E/I balance, thereby playing an essential role in ensuring normal brain functioning.
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Affiliation(s)
- Yehong Du
- Growth, Development, and Mental Health of Children and Adolescence CenterPediatric Research InstituteMinistry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChina International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory DisordersChildren's Hospital of Chongqing Medical UniversityChongqingChina
| | - Junjie Li
- Growth, Development, and Mental Health of Children and Adolescence CenterPediatric Research InstituteMinistry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChina International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory DisordersChildren's Hospital of Chongqing Medical UniversityChongqingChina
| | - Maoju Wang
- Growth, Development, and Mental Health of Children and Adolescence CenterPediatric Research InstituteMinistry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChina International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory DisordersChildren's Hospital of Chongqing Medical UniversityChongqingChina
| | - Qiuyun Tian
- Growth, Development, and Mental Health of Children and Adolescence CenterPediatric Research InstituteMinistry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChina International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory DisordersChildren's Hospital of Chongqing Medical UniversityChongqingChina
| | - Yayan Pang
- Growth, Development, and Mental Health of Children and Adolescence CenterPediatric Research InstituteMinistry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChina International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory DisordersChildren's Hospital of Chongqing Medical UniversityChongqingChina
| | - Ya Wen
- Brain Research Centre and Department of MedicineVancouver Coastal Health Research InstituteUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Dongchuan Wu
- Translational Medicine Research CenterChina Medical University HospitalGraduate Institutes of Biomedical SciencesTaichungChina
| | - Yu Tian Wang
- Brain Research Centre and Department of MedicineVancouver Coastal Health Research InstituteUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Zhifang Dong
- Growth, Development, and Mental Health of Children and Adolescence CenterPediatric Research InstituteMinistry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChina International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory DisordersChildren's Hospital of Chongqing Medical UniversityChongqingChina
- Institute for Brain Science and Disease of Chongqing Medical UniversityChongqingChina
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5
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Beltrán-Matas P, Hartveit E, Veruki ML. Functional properties of GABA A receptors of AII amacrine cells of the rat retina. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1134765. [PMID: 38983040 PMCID: PMC11182327 DOI: 10.3389/fopht.2023.1134765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 03/08/2023] [Indexed: 07/11/2024]
Abstract
Amacrine cells are a highly diverse group of inhibitory retinal interneurons that sculpt the responses of bipolar cells, ganglion cells, and other amacrine cells. They integrate excitatory inputs from bipolar cells and inhibitory inputs from other amacrine cells, but for most amacrine cells, little is known about the specificity and functional properties of their inhibitory inputs. Here, we have investigated GABAA receptors of the AII amacrine, a critical neuron in the rod pathway microcircuit, using patch-clamp recording in rat retinal slices. Puffer application of GABA evoked robust responses, but, surprisingly, spontaneous GABAA receptor-mediated postsynaptic currents were not observed, neither under control conditions nor following application of high-K+ solution to facilitate release. To investigate the biophysical and pharmacological properties of GABAA receptors in AIIs, we therefore used nucleated patches and a fast application system. Both brief and long pulses of GABA (3 mM) evoked GABAA receptor-mediated currents with slow, multi-exponential decay kinetics. The average weighted time constant (τw) of deactivation was ~163 ms. Desensitization was even slower, with τw ~330 ms. Non-stationary noise analysis of patch responses and directly observed channel gating yielded a single-channel conductance of ~23 pS. Pharmacological investigation suggested the presence of α2 and/or α3 subunits, as well as the γ2 subunit. Such subunit combinations are typical of GABAA receptors with slow kinetics. If synaptic GABAA receptors of AII amacrines have similar functional properties, the slow deactivation and desensitization kinetics will facilitate temporal summation of GABAergic inputs, allowing effective summation and synaptic integration to occur even for relatively low frequencies of inhibitory inputs.
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Affiliation(s)
| | - Espen Hartveit
- Department of Biomedicine, University of Bergen, Bergen, Norway
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Gonzalez-Burgos G, Miyamae T, Reddy N, Dawkins S, Chen C, Hill A, Enwright J, Ermentrout B, Lewis DA. Mechanisms regulating the properties of inhibition-based gamma oscillations in primate prefrontal and parietal cortices. Cereb Cortex 2023:7086912. [DOI: 10.1093/cercor/bhad077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 03/29/2023] Open
Abstract
AbstractIn primates, the dorsolateral prefrontal (DLPFC) and posterior parietal (PPC) cortices are key nodes in the working memory network. The working memory-related gamma oscillations induced in these areas, predominantly in layer 3, exhibit higher frequency in DLPFC. Although these regional differences in oscillation frequency are likely essential for information transfer between DLPFC and PPC, the mechanisms underlying these differences remain poorly understood. We investigated, in rhesus monkey, the DLPFC and PPC layer 3 pyramidal neuron (L3PN) properties that might regulate oscillation frequency and assessed the effects of these properties simulating oscillations in computational models. We found that GABAAR-mediated synaptic inhibition synchronizes L3PNs in both areas, but analysis of GABAAR mRNA levels and inhibitory synaptic currents suggested similar mechanisms of inhibition-mediated synchrony in DLPFC and PPC. Basal dendrite spine density and AMPAR/NMDAR mRNA levels were higher in DLPFC L3PNs, whereas excitatory synaptic currents were similar between areas. Therefore, synaptically evoked excitation might be stronger in DLPFC L3PNs due to a greater quantity of synapses in basal dendrites, a main target of recurrent excitation. Simulations in computational networks showed that oscillation frequency and power increased with increasing recurrent excitation, suggesting a mechanism by which the DLPFC–PPC differences in oscillation properties are generated.
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Zhou L, Sun X, Duan J. NMDARs regulate the excitatory-inhibitory balance within neural circuits. BRAIN SCIENCE ADVANCES 2023. [DOI: 10.26599/bsa.2022.9050020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023] Open
Abstract
Excitatory-inhibitory (E/I) balance is essential for normal neural development, behavior and cognition. E/I imbalance leads to a variety of neurological disorders, such as autism and schizophrenia. NMDA receptors (NMDARs) regulate AMPAR-mediated excitatory and GABAAR-mediated inhibitory synaptic transmission, suggesting that NMDARs play an important role in the establishment and maintenance of the E/I balance. In this review, we briefly introduced NMDARs, AMPARs and GABAARs, summarized the current studies on E/I balance mediated by NMDARs, and discussed the current advances in NMDAR-mediated AMPAR and GABAAR development. Specifically, we analyzed the role of NMDAR subunits in the establishment and maintenance of E/I balance, which may provide new therapeutic strategies for the recovery of E/I imbalance in neurological disorders.
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Affiliation(s)
- Liang Zhou
- College of Pharmaceutical Sciences, Soochow University, Suzhou 215123, Jiangsu, China
| | - Xiaohui Sun
- College of Pharmaceutical Sciences, Soochow University, Suzhou 215123, Jiangsu, China
| | - Jingjing Duan
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, Guangdong, China
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8
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Menzikov SA, Zaichenko DM, Moskovtsev AA, Morozov SG, Kubatiev AA. Zinc Inhibits the GABA AR/ATPase during Postnatal Rat Development: The Role of Cysteine Residue. Int J Mol Sci 2023; 24:ijms24032764. [PMID: 36769085 PMCID: PMC9917249 DOI: 10.3390/ijms24032764] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/24/2023] [Accepted: 01/26/2023] [Indexed: 02/04/2023] Open
Abstract
Zinc ions (Zn2+) are concentrated in various brain regions and can act as a neuromodulator, targeting a wide spectrum of postsynaptic receptors and enzymes. Zn2+ inhibits the GABAARs, and its potency is profoundly affected by the subunit composition and neuronal developmental stage. Although the extracellular amino acid residues of the receptor's hetero-oligomeric structure are preferred for Zn2+ binding, there are intracellular sites that, in principle, could coordinate its potency. However, their role in modulating the receptor function during postembryonic development remains unclear. The GABAAR possesses an intracellular ATPase that enables the energy-dependent anion transport via a pore. Here, we propose a mechanistic and molecular basis for the inhibition of intracellular GABAAR/ATPase function by Zn2+ in neonatal and adult rats. The enzymes within the scope of GABAAR performance as Cl-ATPase and then as Cl-, HCO3-ATPase form during the first week of postnatal rat development. In addition, we have shown that the Cl-ATPase form belongs to the β1 subunit, whereas the β3 subunit preferably possesses the Cl-, HCO3-ATPase activity. We demonstrated that a Zn2+ with variable efficacy inhibits the GABAAR as well as the ATPase activities of immature or mature neurons. Using fluorescence recording in the cortical synaptoneurosomes (SNs), we showed a competitive association between Zn2+ and NEM in parallel changes both in the ATPase activity and the GABAAR-mediated Cl- and HCO3- fluxes. Finally, by site-directed mutagenesis, we identified in the M3 domain of β subunits the cysteine residue (C313) that is essential for the manifestation of Zn2+ potency.
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Babij R, Ferrer C, Donatelle A, Wacks S, Buch AM, Niemeyer JE, Ma H, Duan ZRS, Fetcho RN, Che A, Otsuka T, Schwartz TH, Huang BS, Liston C, De Marco García NV. Gabrb3 is required for the functional integration of pyramidal neuron subtypes in the somatosensory cortex. Neuron 2023; 111:256-274.e10. [PMID: 36446382 PMCID: PMC9852093 DOI: 10.1016/j.neuron.2022.10.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 08/30/2022] [Accepted: 10/27/2022] [Indexed: 11/29/2022]
Abstract
Dysfunction of gamma-aminobutyric acid (GABA)ergic circuits is strongly associated with neurodevelopmental disorders. However, it is unclear how genetic predispositions impact circuit assembly. Using in vivo two-photon and widefield calcium imaging in developing mice, we show that Gabrb3, a gene strongly associated with autism spectrum disorder (ASD) and Angelman syndrome (AS), is enriched in contralaterally projecting pyramidal neurons and is required for inhibitory function. We report that Gabrb3 ablation leads to a developmental decrease in GABAergic synapses, increased local network synchrony, and long-lasting enhancement in functional connectivity of contralateral-but not ipsilateral-pyramidal neuron subtypes. In addition, Gabrb3 deletion leads to increased cortical response to tactile stimulation at neonatal stages. Using human transcriptomics and neuroimaging datasets from ASD subjects, we show that the spatial distribution of GABRB3 expression correlates with atypical connectivity in these subjects. Our studies reveal a requirement for Gabrb3 during the emergence of interhemispheric circuits for sensory processing.
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Affiliation(s)
- Rachel Babij
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA.,Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10021, USA
| | - Camilo Ferrer
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Alexander Donatelle
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Sam Wacks
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Amanda M Buch
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - James E Niemeyer
- Department of Neurological Surgery, Weill Cornell Medicine, New-York Presbyterian Hospital, New York, NY 10021, USA
| | - Hongtao Ma
- Department of Neurological Surgery, Weill Cornell Medicine, New-York Presbyterian Hospital, New York, NY 10021, USA
| | - Zhe Ran S Duan
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA.,Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10021, USA
| | - Robert N Fetcho
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA.,Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10021, USA
| | - Alicia Che
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA.,Current affiliation: Department of Psychiatry, Yale School of Medicine, New Haven, CT 06519, USA
| | - Takumi Otsuka
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Theodore H Schwartz
- Department of Neurological Surgery, Weill Cornell Medicine, New-York Presbyterian Hospital, New York, NY 10021, USA
| | - Ben S Huang
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Conor Liston
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Natalia V De Marco García
- Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA.,Lead Contact,Correspondence to
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10
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HDAC1-mediated regulation of GABA signaling within the lateral septum facilitates long-lasting social fear extinction in male mice. Transl Psychiatry 2023; 13:10. [PMID: 36646675 PMCID: PMC9842607 DOI: 10.1038/s41398-023-02310-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 12/31/2022] [Accepted: 01/06/2023] [Indexed: 01/18/2023] Open
Abstract
Social anxiety disorder (SAD) is caused by traumatic social experiences. It is characterized by intense fear and avoidance of social contexts, which can be robustly mimicked by the social fear conditioning (SFC) paradigm. The extinction phase of the SFC paradigm is akin to exposure therapy for SAD and requires learning to disassociate the trauma with the social context. Learning-induced acetylation of histones is critical for extinction memory formation and its endurance. Although class I histone deacetylases (HDACs) regulate the abovementioned learning process, there is a lack of clarity in isoforms and spatial specificity in HDAC function in social learning. Utilizing the SFC paradigm, we functionally characterized the role of HDAC1, specifically in the lateral septum (LS), in regulating the formation of long-term social fear extinction memory. We measured a local increase in activity-inducing HDAC1 phosphorylation at serine residues of social fear-conditioned (SFC+) mice in response to the extinction of social fear. We also found that LS-HDAC1 function negatively correlates with acute social fear extinction learning using pharmacological and viral approaches. Further, inhibition of LS-HDAC1 enhanced the expression of the GABA-A receptor β1 subunit (Gabrb1) in SFC+ mice, and activation of GABA-A receptors facilitated acute extinction learning. Finally, the facilitation of extinction learning by HDAC1 inhibition or GABA-A receptor activation within the LS led to the formation of long-lasting extinction memory, which persisted even 30 days after extinction. Our results show that HDAC1-mediated regulation of GABA signaling in the LS is crucial for the formation of long-lasting social fear extinction memory.
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11
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Castellano D, Wu K, Keramidas A, Lu W. Shisa7-Dependent Regulation of GABA A Receptor Single-Channel Gating Kinetics. J Neurosci 2022; 42:8758-8766. [PMID: 36216503 PMCID: PMC9698691 DOI: 10.1523/jneurosci.0510-22.2022] [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: 03/14/2022] [Revised: 08/19/2022] [Accepted: 09/27/2022] [Indexed: 12/29/2022] Open
Abstract
GABAA receptors (GABAARs) mediate the majority of fast inhibitory transmission throughout the brain. Although it is widely known that pore-forming subunits critically determine receptor function, it is unclear whether their single-channel properties are modulated by GABAAR-associated transmembrane proteins. We previously identified Shisa7 as a GABAAR auxiliary subunit that modulates the trafficking, pharmacology, and deactivation properties of these receptors. However, whether Shisa7 also regulates GABAAR single-channel properties has yet to be determined. Here, we performed single-channel recordings of α2β3γ2L GABAARs cotransfected with Shisa7 in HEK293T cells and found that while Shisa7 does not change channel slope conductance, it reduced the frequency of receptor openings. Importantly, Shisa7 modulates GABAAR gating by decreasing the duration and open probability within bursts. Through kinetic analysis of individual dwell time components, activation modeling, and macroscopic simulations, we demonstrate that Shisa7 accelerates GABAAR deactivation by governing the time spent between close and open states during gating. Together, our data provide a mechanistic basis for how Shisa7 controls GABAAR gating and reveal for the first time that GABAAR single-channel properties can be modulated by an auxiliary subunit. These findings shed light on processes that shape the temporal dynamics of GABAergic transmission.SIGNIFICANCE STATEMENT Although GABAA receptor (GABAAR) single-channel properties are largely determined by pore-forming subunits, it remains unknown whether they are also controlled by GABAAR-associated transmembrane proteins. Here, we show that Shisa7, a recently identified GABAAR auxiliary subunit, modulates GABAAR activation by altering single-channel burst kinetics. These results reveal that Shisa7 primarily decreases the duration and open probability of receptor burst activity during gating, leading to accelerated GABAAR deactivation. These experiments are the first to assess the gating properties of GABAARs in the presence of an auxiliary subunit and provides a kinetic basis for how Shisa7 modifies temporal attributes of GABAergic transmission at the single-channel level.
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Affiliation(s)
- David Castellano
- Synapse and Neural Circuit Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
| | - Kunwei Wu
- Synapse and Neural Circuit Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
| | - Angelo Keramidas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Wei Lu
- Synapse and Neural Circuit Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
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12
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Hozack BA, Kistler JM, Vaccaro AR, Beredjiklian PK. Benzodiazepines and Related Drugs in Orthopaedics. J Bone Joint Surg Am 2022; 104:2204-2210. [PMID: 36223476 DOI: 10.2106/jbjs.22.00516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
➤ Benzodiazepines are among the most commonly prescribed drugs worldwide and are often used as anxiolytics, hypnotics, anticonvulsants, and muscle relaxants. ➤ The risk of dependence on and abuse of these medications has recently gained more attention in light of the current opioid epidemic. ➤ Benzodiazepines can increase the risk of prolonged opioid use and abuse. ➤ Given the prevalence of the use of benzodiazepines and related drugs, orthopaedic patients are often prescribed these medications. ➤ Orthopaedic surgeons need to be aware of the prevalence of benzodiazepine and related drug prescriptions in the general population, their current uses in orthopaedic surgery, and the risks and adverse effects of their use.
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Affiliation(s)
- Bryan A Hozack
- Rothman Orthopaedic Institute, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
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13
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Langlois LD, Selvaraj P, Simmons SC, Gouty S, Zhang Y, Nugent FS. Repetitive mild traumatic brain injury induces persistent alterations in spontaneous synaptic activity of hippocampal CA1 pyramidal neurons. IBRO Neurosci Rep 2022; 12:157-162. [PMID: 35746968 PMCID: PMC9210462 DOI: 10.1016/j.ibneur.2022.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/20/2021] [Accepted: 02/07/2022] [Indexed: 11/17/2022] Open
Abstract
Mild traumatic brain injury (mTBI) or concussion is the most common form of TBI which frequently results in persistent cognitive impairments and memory deficits in affected individuals [1]. Although most studies have investigated the role of hippocampal synaptic dysfunction in earlier time points following a single injury, the long-lasting effects of mTBI on hippocampal synaptic transmission following multiple brain concussions have not been well-elucidated. Using a repetitive closed head injury (3XCHI) mouse model of mTBI, we examined the alteration of spontaneous synaptic transmission onto hippocampal CA1 pyramidal neurons by recording spontaneous excitatory AMPA receptor (AMPAR)- and inhibitory GABAAR-mediated postsynaptic currents (sEPSCs and sIPSCs, respectively) in adult male mice 2-weeks following the injury. We found that mTBI potentiated postsynaptic excitatory AMPAR synaptic function while depressed postsynaptic inhibitory GABAAR synaptic function in CA1 pyramidal neurons. Additionally, mTBI slowed the decay time of AMPAR currents while shortened the decay time of GABAAR currents suggesting changes in AMPAR and GABAAR subunit composition by mTBI. On the other hand, mTBI reduced the frequency of sEPSCs while enhanced the frequency of sIPSCs resulting in a lower ratio of sEPSC/sIPSC frequency in CA1 pyramidal neurons of mTBI animals compared to sham animals. Altogether, our results suggest that mTBI induces persistent postsynaptic modifications in AMPAR and GABAAR function and their synaptic composition in CA1 neurons while triggering a compensatory shift in excitation/inhibition (E/I) balance of presynaptic drives towards more inhibitory synaptic drive to hippocampal CA1 cells. The persistent mTBI-induced CA1 synaptic dysfunction and E/I imbalance could contribute to deficits in hippocampal plasticity that underlies long-term hippocampal-dependent learning and memory deficits in mTBI patients long after the initial injury.
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Affiliation(s)
- Ludovic D. Langlois
- Uniformed Services University of the Health Sciences, Edward Hebert School of Medicine, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD 20814, USA
| | - Prabhuanand Selvaraj
- Uniformed Services University of the Health Sciences, Edward Hebert School of Medicine, Department of Anatomy, Physiology and Genetics, Bethesda, MD 20814, USA
| | - Sarah C. Simmons
- Uniformed Services University of the Health Sciences, Edward Hebert School of Medicine, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD 20814, USA
| | - Shawn Gouty
- Uniformed Services University of the Health Sciences, Edward Hebert School of Medicine, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD 20814, USA
| | - Yumin Zhang
- Uniformed Services University of the Health Sciences, Edward Hebert School of Medicine, Department of Anatomy, Physiology and Genetics, Bethesda, MD 20814, USA
- Corresponding authors.
| | - Fereshteh S. Nugent
- Uniformed Services University of the Health Sciences, Edward Hebert School of Medicine, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD 20814, USA
- Corresponding authors.
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14
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Cao T, Chen H, Huang W, Xu S, Liu P, Zou W, Pang M, Xu Y, Bai X, Liu B, Rong L, Cui ZK, Li M. hUC-MSC-mediated recovery of subacute spinal cord injury through enhancing the pivotal subunits β3 and γ2 of the GABA A receptor. Theranostics 2022; 12:3057-3078. [PMID: 35547766 PMCID: PMC9065192 DOI: 10.7150/thno.72015] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 03/12/2022] [Indexed: 12/19/2022] Open
Abstract
Rationale: Spinal cord injury (SCI) remains an incurable neurological disorder leading to permanent and profound neurologic deficits and disabilities. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) are particularly appealing in SCI treatment to curtail damage, restore homeostasis and possible neural relay. However, the detailed mechanisms underlying hUC-MSC-mediated functional recovery of SCI have not been fully elucidated. The purpose of our current study is to identify novel therapeutic targets and depict the molecular mechanisms underlying the hUC-MSC-mediated recovery of subacute SCI. Methods: Adult female rats suffering from subacute incomplete thoracic SCI were treated with intrathecal transplantation of hUC-MSCs. The beneficial effects of hUC-MSCs on SCI repair were evaluated by a series of behavioral analyses, motor evoked potentials (MEPs) recording of hindlimb and immunohistochemistry. We carried out extensive transcriptome comparative analyses of spinal cord tissues at the lesion site from the subacute phase of SCI (sub-SCI) either treated without (+PBS) or with hUC-MSCs (+MSC) at 0 (sub-SCI), 1, 2, and 4 weeks post-transplantation (wpt), as well as normal spinal cord segments of intact/sham rats (Intact). Adeno-associated virus (AAV)-mediated neuron-specific expression system was employed to functionally screen specific γ-aminobutyric acid type A receptor (GABAAR) subunits promoting the functional recovery of SCI in vivo. The mature cortical axon scrape assay and transplantation of genetically modified MSCs with either overexpression or knockdown of brain-derived neurotrophic factor (BDNF) were employed to demonstrate that hUC-MSCs ameliorated the reduction of GABAAR subunits in the injured spinal cord via BDNF secretion in vitro and in vivo, respectively. Results: Comparative transcriptome analysis revealed the GABAergic synapse pathway is significantly enriched as a main target of hUC-MSC-activated genes in the injured spinal cord. Functional screening of the primary GABAAR subunits uncovered that Gabrb3 and Garbg2 harbored the motor and electrophysiological recovery-promoting competence. Moreover, targeting either of the two pivotal subunits β3 or γ2 in combination with/without the K+/Cl- cotransporter 2 (KCC2) reinforced the therapeutic effects. Mechanistically, BDNF secreted by hUC-MSCs contributed to the upregulation of GABAAR subunits (β3 & γ2) and KCC2 in the injured neurons. Conclusions: Our study identifies a novel mode for hUC-MSC-mediated locomotor recovery of SCI through synergistic upregulation of GABAAR β3 and γ2 along with KCC2 by BDNF secretion, indicating the significance of restoring the excitation/inhibition balance in the injured neurons for the reestablishment of neuronal circuits. This study also provides a potential combinatorial approach by targeting the pivotal subunit β3 or γ2 and KCC2, opening up possibilities for efficacious drug design.
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Affiliation(s)
- Tingting Cao
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Huan Chen
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Weiping Huang
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Sisi Xu
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Peilin Liu
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Weiwei Zou
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Mao Pang
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510515, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, 510630, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, 510630, China
| | - Ying Xu
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510515, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, 510630, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, 510630, China
| | - Xiaochun Bai
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Bin Liu
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510515, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, 510630, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, 510630, China
| | - Limin Rong
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510515, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, 510630, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, 510630, China
| | - Zhong-Kai Cui
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Mangmang Li
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
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15
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Menzikov SA, Zaichenko DM, Moskovtsev AA, Morozov SG, Kubatiev AA. Physiological Role of ATPase for GABA A Receptor Resensitization. Int J Mol Sci 2022; 23:ijms23105320. [PMID: 35628132 PMCID: PMC9141714 DOI: 10.3390/ijms23105320] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/03/2022] [Accepted: 05/07/2022] [Indexed: 02/01/2023] Open
Abstract
γ-Aminobutyric acid type A receptors (GABAARs) mediate primarily inhibitory synaptic transmission in the central nervous system. Following fast-paced activation, which provides the selective flow of mainly chloride (Cl−) and less bicarbonate (HCO3−) ions via the pore, these receptors undergo desensitization that is paradoxically prevented by the process of their recovery, referred to as resensitization. To clarify the mechanism of resensitization, we used the cortical synaptoneurosomes from the rat brain and HEK 293FT cells. Here, we describe the effect of γ-phosphate analogues (γPAs) that mimic various states of ATP hydrolysis on GABAAR-mediated Cl− and HCO3− fluxes in response to the first and repeated application of the agonist. We found that depending on the presence of bicarbonate, opened and desensitized states of the wild or chimeric GABAARs had different sensitivities to γPAs. This study presents the evidence that recovery of neuronal Cl− and HCO3− concentrations after desensitization is accompanied by a change in the intracellular ATP concentration via ATPase performance. The transition between the desensitization and resensitization states was linked to changes in both conformation and phosphorylation. In addition, the chimeric β3 isoform did not exhibit the desensitization of the GABAAR-mediated Cl− influx but only the resensitization. These observations lend a new physiological significance to the β3 subunit in the manifestation of GABAAR resensitization.
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Affiliation(s)
- Sergey A. Menzikov
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, 8, Baltiyskaya St., 125315 Moscow, Russia; (D.M.Z.); (A.A.M.); (S.G.M.); (A.A.K.)
- Correspondence: ; Tel.: +7-(499)-151-1756; Fax: +7-(495)-601-2366
| | - Danila M. Zaichenko
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, 8, Baltiyskaya St., 125315 Moscow, Russia; (D.M.Z.); (A.A.M.); (S.G.M.); (A.A.K.)
| | - Aleksey A. Moskovtsev
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, 8, Baltiyskaya St., 125315 Moscow, Russia; (D.M.Z.); (A.A.M.); (S.G.M.); (A.A.K.)
- Russian Medical Academy of Postdoctoral Education, Federal State Budgetary Educational Institution of Further Professional Education of the Ministry of Healthcare of the Russian Federation, 2/1, Barrykadnaya St., 125993 Moscow, Russia
| | - Sergey G. Morozov
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, 8, Baltiyskaya St., 125315 Moscow, Russia; (D.M.Z.); (A.A.M.); (S.G.M.); (A.A.K.)
| | - Aslan A. Kubatiev
- Institute of General Pathology and Pathophysiology, Russian Academy of Sciences, 8, Baltiyskaya St., 125315 Moscow, Russia; (D.M.Z.); (A.A.M.); (S.G.M.); (A.A.K.)
- Russian Medical Academy of Postdoctoral Education, Federal State Budgetary Educational Institution of Further Professional Education of the Ministry of Healthcare of the Russian Federation, 2/1, Barrykadnaya St., 125993 Moscow, Russia
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16
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Michalettos G, Ruscher K. Crosstalk Between GABAergic Neurotransmission and Inflammatory Cascades in the Post-ischemic Brain: Relevance for Stroke Recovery. Front Cell Neurosci 2022; 16:807911. [PMID: 35401118 PMCID: PMC8983863 DOI: 10.3389/fncel.2022.807911] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/28/2022] [Indexed: 11/28/2022] Open
Abstract
Adaptive plasticity processes are required involving neurons as well as non-neuronal cells to recover lost brain functions after an ischemic stroke. Recent studies show that gamma-Aminobutyric acid (GABA) has profound effects on glial and immune cell functions in addition to its inhibitory actions on neuronal circuits in the post-ischemic brain. Here, we provide an overview of how GABAergic neurotransmission changes during the first weeks after stroke and how GABA affects functions of astroglial and microglial cells as well as peripheral immune cell populations accumulating in the ischemic territory and brain regions remote to the lesion. Moreover, we will summarize recent studies providing data on the immunomodulatory actions of GABA of relevance for stroke recovery. Interestingly, the activation of GABA receptors on immune cells exerts a downregulation of detrimental anti-inflammatory cascades. Conversely, we will discuss studies addressing how specific inflammatory cascades affect GABAergic neurotransmission on the level of GABA receptor composition, GABA synthesis, and release. In particular, the chemokines CXCR4 and CX3CR1 pathways have been demonstrated to modulate receptor composition and synthesis. Together, the actual view on the interactions between GABAergic neurotransmission and inflammatory cascades points towards a specific crosstalk in the post-ischemic brain. Similar to what has been shown in experimental models, specific therapeutic modulation of GABAergic neurotransmission and inflammatory pathways may synergistically promote neuronal plasticity to enhance stroke recovery.
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Affiliation(s)
- Georgios Michalettos
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical Sciences, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Karsten Ruscher
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical Sciences, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
- LUBIN Lab—Lunds Laboratorium för Neurokirurgisk Hjärnskadeforskning, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
- *Correspondence: Karsten Ruscher
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17
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Mellado S, Moreno-Ruiz B, Expósito S, Fernández M, Martín ED. Prolactin Reduces Hippocampal Parvalbumin and GABAA Receptor Expression in Female Mice. Neuroendocrinology 2022; 112:796-806. [PMID: 34666336 PMCID: PMC9533442 DOI: 10.1159/000520279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 10/18/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Parvalbumin (PV)-positive cells are strategic elements of neuronal networks capable of influencing memory and learning processes. However, it is not known whether pituitary hormones may be related to PV expression in the hippocampus - a part of the limbic system with important functions in learning and memory. OBJECTIVE Since previous studies indicate that prolactin (PRL) plays a significant role in hippocampal-dependent learning and synaptic plasticity, we hypothesized that a rise in PRL levels can modify PV expression in the hippocampus. METHODS We employed biochemical, immunohistochemistry, and densitometry techniques - as well as a behavioural assay - in a hyperprolactinemia model using subcutaneous osmotic pumps in female mice. RESULTS PRL treatment via osmotic pump induced an increase in PRL receptor (PRLR) expression in most regions of the hippocampus analysed by Western blotting and immunohistochemistry methods. Fluorescent densitometry analysis revealed that PV expression decreases in the same layers in the hippocampus following PRL treatment, while double labelling immunostaining indicated close localization of PV and PRLR in PV-positive interneurons. In addition, we found that PRL induced a reduction in the β2/3 subunit of GABAA receptor (GABAAR) expression that was linearly correlated with the reduction in PV expression. This reduction in the β2/3 subunit of GABAAR expression was maintained in trained animals in which PRL treatment improved the learning of a spatial memory task. CONCLUSIONS These data show, for the first time, that an increase in PRL level is associated with changes in key constituent elements of inhibitory circuits in the hippocampus and may be of relevance for the alterations in cognitive function reported in hyperprolactinemia.
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Affiliation(s)
- Susana Mellado
- Laboratory of Neurophysiology and Synaptic Plasticity, Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Beatriz Moreno-Ruiz
- Laboratory of Neurophysiology and Synaptic Plasticity, Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Sara Expósito
- Laboratory of Neurophysiology and Synaptic Plasticity, Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Miriam Fernández
- Research Institute for Neurological Disabilities (IDINE), Medical School, University of Castilla-La Mancha, Albacete, Spain
| | - Eduardo D. Martín
- Laboratory of Neurophysiology and Synaptic Plasticity, Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain
- *Eduardo D. Martín,
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18
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Selvaraj P, Tanaka M, Wen J, Zhang Y. The Novel Monoacylglycerol Lipase Inhibitor MJN110 Suppresses Neuroinflammation, Normalizes Synaptic Composition and Improves Behavioral Performance in the Repetitive Traumatic Brain Injury Mouse Model. Cells 2021; 10:cells10123454. [PMID: 34943962 PMCID: PMC8700188 DOI: 10.3390/cells10123454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 12/22/2022] Open
Abstract
Modulation of the endocannabinoid system has emerged as an effective approach for the treatment of many neurodegenerative and neuropsychological diseases. However, the underlying mechanisms are still uncertain. Using a repetitive mild traumatic brain injury (mTBI) mouse model, we found that there was an impairment in locomotor function and working memory within two weeks post-injury, and that treatment with MJN110, a novel inhibitor of the principal 2-arachidononyl glycerol (2-AG) hydrolytic enzyme monoacylglycerol lipase dose-dependently ameliorated those behavioral changes. Spatial learning and memory deficits examined by Morris water maze between three and four weeks post-TBI were also reversed in the drug treated animals. Administration of MJN110 selectively elevated the levels of 2-AG and reduced the production of arachidonic acid (AA) and prostaglandin E2 (PGE2) in the TBI mouse brain. The increased production of proinflammatory cytokines, accumulation of astrocytes and microglia in the TBI mouse ipsilateral cerebral cortex and hippocampus were significantly reduced by MJN110 treatment. Neuronal cell death was also attenuated in the drug treated animals. MJN110 treatment normalized the expression of the NMDA receptor subunits NR2A and NR2B, the AMPA receptor subunits GluR1 and GluR2, and the GABAA receptor subunits α1, β2,3 and γ2, which were all reduced at 1, 2 and 4 weeks post-injury. The reduced inflammatory response and restored glutamate and GABA receptor expression likely contribute to the improved motor function, learning and memory in the MJN110 treated animals. The therapeutic effects of MJN110 were partially mediated by activation of CB1 and CB2 cannabinoid receptors and were eliminated when it was co-administered with DO34, a novel inhibitor of the 2-AG biosynthetic enzymes. Our results suggest that augmentation of the endogenous levels of 2-AG can be therapeutically useful in the treatment of TBI by suppressing neuroinflammation and maintaining the balance between excitatory and inhibitory neurotransmission.
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Affiliation(s)
- Prabhuanand Selvaraj
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA; (P.S.); (M.T.); (J.W.)
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
| | - Mikiei Tanaka
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA; (P.S.); (M.T.); (J.W.)
| | - Jie Wen
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA; (P.S.); (M.T.); (J.W.)
| | - Yumin Zhang
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA; (P.S.); (M.T.); (J.W.)
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
- Correspondence: ; Tel.: +1-301-295-3212
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19
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Michalettos G, Walter HL, Antunes ARP, Wieloch T, Talhada D, Ruscher K. Effect of Anti-inflammatory Treatment with AMD3100 and CX 3CR1 Deficiency on GABA A Receptor Subunit and Expression of Glutamate Decarboxylase Isoforms After Stroke. Mol Neurobiol 2021; 58:5876-5889. [PMID: 34417725 PMCID: PMC8599239 DOI: 10.1007/s12035-021-02510-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 07/29/2021] [Indexed: 11/24/2022]
Abstract
Following stroke, attenuation of detrimental inflammatory pathways might be a promising strategy to improve long-term outcome. In particular, cascades driven by pro-inflammatory chemokines interact with neurotransmitter systems such as the GABAergic system. This crosstalk might be of relevance for mechanisms of neuronal plasticity, however, detailed studies are lacking. The purpose of this study was to determine if treatment with 1,1′-[1,4-phenylenebis(methylene)]bis[1,4,8,11-tetraazacyclotetradecane] (AMD3100), an antagonist to the C-X-C chemokine receptor type 4 (CXCR4) and partial allosteric agonist to CXCR7 (AMD3100) alone or in combination with C-X3-C chemokine receptor type 1 (CX3CR1) deficiency, affect the expression of GABAA subunits and glutamate decarboxylase (GAD) isoforms. Heterozygous, CX3CR1-deficient mice and wild-type littermates were subjected to photothrombosis (PT). Treatment with AMD3100 (0.5 mg/kg twice daily i.p.) was administered starting from day 2 after induction of PT until day 14 after the insult. At this time point, GABAA receptor subunits (α3, β3, δ), GAD65 and GAD67, and CXCR4 were analyzed from the peri-infarct tissue and homotypic brain regions of the contralateral hemisphere by quantitative real-time PCR and Western Blot. Fourteen days after PT, CX3CR1 deficiency resulted in a significant decrease of the three GABAA receptor subunits in both the lesioned and the contralateral hemisphere compared to sham-operated mice. Treatment with AMD3100 promoted the down-regulation of GABAA subunits and GAD67 in the ipsilateral peri-infarct area, while the β3 subunit and the GAD isoforms were up-regulated in homotypic regions of the contralateral cortex. Changes in GABAA receptor subunits and GABA synthesis suggest that the CXCR4/7 and CX3CR1 signaling pathways are involved in the regulation of GABAergic neurotransmission in the post-ischemic brain.
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Affiliation(s)
- Georgios Michalettos
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical Sciences, Wallenberg Neuroscience Center, Lund University, BMC A13, S-22184, Lund, Sweden
| | - Helene L Walter
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical Sciences, Wallenberg Neuroscience Center, Lund University, BMC A13, S-22184, Lund, Sweden.,Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Ana Rita Pombo Antunes
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical Sciences, Wallenberg Neuroscience Center, Lund University, BMC A13, S-22184, Lund, Sweden
| | - Tadeusz Wieloch
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical Sciences, Wallenberg Neuroscience Center, Lund University, BMC A13, S-22184, Lund, Sweden
| | - Daniela Talhada
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical Sciences, Wallenberg Neuroscience Center, Lund University, BMC A13, S-22184, Lund, Sweden
| | - Karsten Ruscher
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical Sciences, Wallenberg Neuroscience Center, Lund University, BMC A13, S-22184, Lund, Sweden. .,LUBIN Lab - Lunds Laboratorium För Neurokirurgisk Hjärnskadeforskning, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden.
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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: 2] [Impact Index Per Article: 0.7] [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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21
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Electrophysiology of ionotropic GABA receptors. Cell Mol Life Sci 2021; 78:5341-5370. [PMID: 34061215 PMCID: PMC8257536 DOI: 10.1007/s00018-021-03846-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/02/2021] [Accepted: 04/23/2021] [Indexed: 10/30/2022]
Abstract
GABAA receptors are ligand-gated chloride channels and ionotropic receptors of GABA, the main inhibitory neurotransmitter in vertebrates. In this review, we discuss the major and diverse roles GABAA receptors play in the regulation of neuronal communication and the functioning of the brain. GABAA receptors have complex electrophysiological properties that enable them to mediate different types of currents such as phasic and tonic inhibitory currents. Their activity is finely regulated by membrane voltage, phosphorylation and several ions. GABAA receptors are pentameric and are assembled from a diverse set of subunits. They are subdivided into numerous subtypes, which differ widely in expression patterns, distribution and electrical activity. Substantial variations in macroscopic neural behavior can emerge from minor differences in structure and molecular activity between subtypes. Therefore, the diversity of GABAA receptors widens the neuronal repertoire of responses to external signals and contributes to shaping the electrical activity of neurons and other cell types.
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Sadamitsu K, Shigemitsu L, Suzuki M, Ito D, Kashima M, Hirata H. Characterization of zebrafish GABA A receptor subunits. Sci Rep 2021; 11:6242. [PMID: 33737538 PMCID: PMC7973766 DOI: 10.1038/s41598-021-84646-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/18/2021] [Indexed: 11/23/2022] Open
Abstract
γ-Aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system, exerts its effect through the activation of GABA receptors. GABAA receptors are ligand-gated chloride channels composed of five subunit proteins. Mammals have 19 different GABAA receptor subunits (α1–6, β1–3, γ1–3, δ, ε, π, θ, and ρ1–3), the physiological properties of which have been assayed by electrophysiology. However, the evolutionary conservation of the physiological characteristics of diverged GABAA receptor subunits remains unclear. Zebrafish have 23 subunits (α1, α2a, α2b, α3–5, α6a, α6b, β1–4, γ1–3, δ, π, ζ, ρ1, ρ2a, ρ2b, ρ3a, and ρ3b), but the electrophysiological properties of these subunits have not been explored. In this study, we cloned the coding sequences for zebrafish GABAA receptor subunits and investigated their expression patterns in larval zebrafish by whole-mount in situ hybridization. We also performed electrophysiological recordings of GABA-evoked currents from Xenopus oocytes injected with one or multiple zebrafish GABAA receptor subunit cRNAs and calculated the half-maximal effective concentrations (EC50s) for each. Our results revealed the spatial expressions and electrophysiological GABA sensitivities of zebrafish GABAA receptors, suggesting that the properties of GABAA receptor subunits are conserved among vertebrates.
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Affiliation(s)
- Kenichiro Sadamitsu
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, 252-5258, Japan
| | - Leona Shigemitsu
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, 252-5258, Japan
| | - Marina Suzuki
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, 252-5258, Japan
| | - Daishi Ito
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, 252-5258, Japan
| | - Makoto Kashima
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, 252-5258, Japan
| | - Hiromi Hirata
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, 252-5258, Japan.
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23
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Kim JJ, Hibbs RE. Direct Structural Insights into GABA A Receptor Pharmacology. Trends Biochem Sci 2021; 46:502-517. [PMID: 33674151 DOI: 10.1016/j.tibs.2021.01.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/08/2021] [Accepted: 01/25/2021] [Indexed: 12/18/2022]
Abstract
GABAA receptors are pentameric ligand-gated ion channels that mediate most fast neuronal inhibition in the brain. In addition to their important physiological roles, they are noteworthy in their rich pharmacology; prominent drugs used for anxiety, insomnia, and general anesthesia act through positive modulation of GABAA receptors. Direct structural information for how these drugs work was absent until recently. Efforts in structural biology over the past few years have revealed how important drug classes and natural products interact with the GABAA receptor, providing a foundation for studies in dynamics and structure-guided drug design. Here, we review recent developments in GABAA receptor structural pharmacology, focusing on subunit assemblies of the receptor found at synapses.
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Affiliation(s)
- Jeong Joo Kim
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ryan E Hibbs
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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24
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George S, Chiou TT, Kanamalla K, De Blas AL. Recruitment of Plasma Membrane GABA-A Receptors by Submembranous Gephyrin/Collybistin Clusters. Cell Mol Neurobiol 2021; 42:1585-1604. [PMID: 33547626 DOI: 10.1007/s10571-021-01050-1] [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: 08/20/2020] [Accepted: 01/23/2021] [Indexed: 11/29/2022]
Abstract
It has been shown that subunit composition is the main determinant of the synaptic or extrasynaptic localization of GABAA receptors (GABAARs). Synaptic and extrasynaptic GABAARs are involved in phasic and tonic inhibition, respectively. It has been proposed that synaptic GABAARs bind to the postsynaptic gephyrin/collybistin (Geph/CB) lattice, but not the typically extrasynaptic GABAARs. Nevertheless, there are no studies of the direct binding of various types of GABAARs with the submembranous Geph/CB lattice in the absence of other synaptic proteins, some of which are known to interact with GABAARs. We have reconstituted GABAARs of various subunit compositions, together with the Geph/CB scaffold, in HEK293 cells, and have investigated the recruitment of surface GABAARs by submembranous Geph/CB clusters. Results show that the typically synaptic α1β3γ2 GABAARs were trapped by submembranous Geph/CB clusters. The α5β3γ2 GABAARs, which are both synaptic and extrasynaptic, were also trapped by Geph/CB clusters. Extrasynaptic α4β3δ GABAARs consistently showed little or no trapping by the Geph/CB clusters. However, the extrasynaptic α6β3δ, α1β3, α6β3 (and less α4β3) GABAARs were highly trapped by the Geph/CB clusters. AMPA and NMDA glutamate receptors were not trapped. The results suggest: (I) in the absence of other synaptic molecules, the Geph/CB lattice has the capacity to trap not only synaptic but also several typically extrasynaptic GABAARs; (II) the Geph/CB lattice is important but does not play a decisive role in the synaptic localization of GABAARs; and (III) in neurons there must be mechanisms preventing the trapping of several typically extrasynaptic GABAARs by the postsynaptic Geph/CB lattice.
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Affiliation(s)
- Shanu George
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, U-3156, Storrs, CT, 06269-3156, USA
| | - Tzu-Ting Chiou
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, U-3156, Storrs, CT, 06269-3156, USA
| | - Karthik Kanamalla
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, U-3156, Storrs, CT, 06269-3156, USA
| | - Angel L De Blas
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, U-3156, Storrs, CT, 06269-3156, USA.
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25
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Intricacies of GABA A Receptor Function: The Critical Role of the β3 Subunit in Norm and Pathology. Int J Mol Sci 2021; 22:ijms22031457. [PMID: 33535681 PMCID: PMC7867123 DOI: 10.3390/ijms22031457] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/23/2022] Open
Abstract
Neuronal intracellular chloride ([Cl−]i) is a key determinant in γ-aminobutyric acid type A (GABA)ergic signaling. γ-Aminobutyric acid type A receptors (GABAARs) mediate both inhibitory and excitatory neurotransmission, as the passive fluxes of Cl− and HCO3− via pores can be reversed by changes in the transmembrane concentration gradient of Cl−. The cation–chloride co-transporters (CCCs) are the primary systems for maintaining [Cl−]i homeostasis. However, despite extensive electrophysiological data obtained in vitro that are supported by a wide range of molecular biological studies on the expression patterns and properties of CCCs, the presence of ontogenetic changes in [Cl−]i—along with the consequent shift in GABA reversal potential—remain a subject of debate. Recent studies showed that the β3 subunit possesses properties of the P-type ATPase that participates in the ATP-consuming movement of Cl− via the receptor. Moreover, row studies have demonstrated that the β3 subunit is a key player in GABAAR performance and in the appearance of serious neurological disorders. In this review, we discuss the properties and driving forces of CCCs and Cl−, HCO3−ATPase in the maintenance of [Cl−]i homeostasis after changes in upcoming GABAAR function. Moreover, we discuss the contribution of the β3 subunit in the manifestation of epilepsy, autism, and other syndromes.
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26
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Cai X, Li Y, Zheng X, Hu R, Li Y, Xiao L, Wang Z. Propofol suppresses microglial phagocytosis through the downregulation of MFG-E8. J Neuroinflammation 2021; 18:18. [PMID: 33422097 PMCID: PMC7796553 DOI: 10.1186/s12974-020-02061-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 12/16/2020] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Microglia are highly motile phagocytic cells in the healthy brain with surveillance and clearance functions. Although microglia have been shown to engulf cellular debris following brain insult, less is known about their phagocytic function in the absence of injury. Propofol can inhibit microglial activity, including phagocytosis. Milk fat globule epidermal growth factor 8 (MFG-E8), as a regulator of microglia, plays an essential role in the phagocytic process. However, whether MFG-E8 affects the alteration of phagocytosis by propofol remains unknown. METHODS Microglial BV2 cells were treated with propofol, with or without MFG-E8. Phagocytosis of latex beads was evaluated by flow cytometry and immunofluorescence. MFG-E8, p-AMPK, AMPK, p-Src, and Src levels were assessed by western blot analysis. Compound C (AMPK inhibitor) and dasatinib (Src inhibitor) were applied to determine the roles of AMPK and Src in microglial phagocytosis under propofol treatment. RESULTS The phagocytic ability of microglia was significantly decreased after propofol treatment for 4 h (P < 0.05). MFG-E8 production was inhibited by propofol in a concentration- and time-dependent manner (P < 0.05). Preadministration of MFG-E8 dose-dependently (from 10 to 100 ng/ml) reversed the suppression of phagocytosis by propofol (P < 0.05). Furthermore, the decline in p-AMPK and p-Src levels induced by propofol intervention was reversed by MFG-E8 activation (P < 0.05). Administration of compound C (AMPK inhibitor) and dasatinib (Src inhibitor) to microglia blocked the trend of enhanced phagocytosis induced by MFG-E8 (P < 0.05). CONCLUSIONS These findings reveal the intermediate role of MFG-E8 between propofol and microglial phagocytic activity. Moreover, MFG-E8 may reverse the suppression of phagocytosis induced by propofol through the regulation of the AMPK and Src signaling pathways.
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Affiliation(s)
- Xiaoying Cai
- Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Ying Li
- Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Xiaoyang Zheng
- Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Rong Hu
- Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Yingyuan Li
- Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Liangcan Xiao
- Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China.
| | - Zhongxing Wang
- Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China.
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27
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Steinecke A, Kurabayashi N, Hayano Y, Ishino Y, Taniguchi H. In Vivo Single-Cell Genotyping of Mouse Cortical Neurons Transfected with CRISPR/Cas9. Cell Rep 2020; 28:325-331.e4. [PMID: 31291570 DOI: 10.1016/j.celrep.2019.06.038] [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: 10/17/2018] [Revised: 04/15/2019] [Accepted: 06/08/2019] [Indexed: 10/26/2022] Open
Abstract
CRISPR/Cas-based technologies have revolutionized genetic approaches to addressing a wide range of neurobiological questions. The ability of CRISPR/Cas to introduce mutations into target genes allows us to perform in vivo loss-of-function experiments without generating genetically engineered mice. However, the lack of a reliable method to determine genotypes of individual CRISPR/Cas-transfected cells has made it impossible to unambiguously identify the genetic cause of their phenotypes in vivo. Here, we report a strategy for single-cell genotyping in CRISPR/Cas-transfected neurons that were phenotypically characterized in vivo. We show that re-sectioning of cortical slices and subsequent laser microdissection allow us to isolate individual CRISPR/Cas-transfected neurons. Sequencing of PCR products containing a CRISPR/Cas-targeted genomic region in single reference neurons provided genotypes that completely correspond with those deduced from their target protein expression and phenotypes. Thus, our study establishes a powerful strategy to determine the causality between genotypes and phenotypes in CRISPR/Cas-transfected neurons.
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Affiliation(s)
- André Steinecke
- Development and Function of Inhibitory Neural Circuits, Max Planck Florida Institute for Neuroscience, One Max Planck Way, Jupiter, FL 33458, USA
| | - Nobuhiro Kurabayashi
- Development and Function of Inhibitory Neural Circuits, Max Planck Florida Institute for Neuroscience, One Max Planck Way, Jupiter, FL 33458, USA; Life Science Research Center, University of Toyama, Toyama 930-0194, Japan
| | - Yasufumi Hayano
- Development and Function of Inhibitory Neural Circuits, Max Planck Florida Institute for Neuroscience, One Max Planck Way, Jupiter, FL 33458, USA
| | - Yugo Ishino
- Development and Function of Inhibitory Neural Circuits, Max Planck Florida Institute for Neuroscience, One Max Planck Way, Jupiter, FL 33458, USA
| | - Hiroki Taniguchi
- Development and Function of Inhibitory Neural Circuits, Max Planck Florida Institute for Neuroscience, One Max Planck Way, Jupiter, FL 33458, USA.
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28
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Moyses-Oliveira M, Yadav R, Erdin S, Talkowski ME. New gene discoveries highlight functional convergence in autism and related neurodevelopmental disorders. Curr Opin Genet Dev 2020; 65:195-206. [PMID: 32846283 DOI: 10.1016/j.gde.2020.07.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/30/2020] [Accepted: 07/06/2020] [Indexed: 01/06/2023]
Abstract
Over the last two years, remarkable gene discovery efforts have implicated disruption of pathways involving gene regulatory functions and neuronal processes in autism spectrum disorder (ASD), and more broadly defined neurodevelopmental disorders (NDDs). Functional studies in the developing brain and across cell types demonstrate that the spatiotemporal expression patterns of many of these genes coalesce on subnetworks with distinct developmental trajectories. Here, we review the convergent biological processes derived from gene discovery and functional genomics in ASD and NDD from 2018-2020. We further probe the mechanistic insights that suggest these frequently perturbed pathways are interconnected and, ultimately, converge on specific functional deficits in human neurodevelopment.
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Affiliation(s)
- Mariana Moyses-Oliveira
- Center for Genomic Medicine, Massachusetts General Hospital, Boston MA, United States; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston MA, United States; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge MA, United States; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - Rachita Yadav
- Center for Genomic Medicine, Massachusetts General Hospital, Boston MA, United States; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston MA, United States; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge MA, United States; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - Serkan Erdin
- Center for Genomic Medicine, Massachusetts General Hospital, Boston MA, United States; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge MA, United States; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - Michael E Talkowski
- Center for Genomic Medicine, Massachusetts General Hospital, Boston MA, United States; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston MA, United States; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge MA, United States; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, United States.
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29
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Menzikov SA, Zaichenko DM, Moskovtsev AA, Morozov SG, Kubatiev AA. Ectopic GABA A receptor β3 subunit determines Cl - / HCO 3 - -ATPase and chloride transport in HEK 293FT cells. FEBS J 2020; 288:699-712. [PMID: 32383536 DOI: 10.1111/febs.15359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 04/09/2020] [Accepted: 05/04/2020] [Indexed: 01/20/2023]
Abstract
Neuronal intracellular chloride concentration ([Cl- ]i ) is a crucial determinant of transmission mediated by the γ-aminobutyric acid type A receptor (GABAA R), which subserves synaptic and extrasynaptic inhibition as well as excitation. The Cl- ion is the main carrier of charge through the GABAA R; however, bicarbonate ions ( HCO 3 - ) flowing in the opposite direction can also contribute to the net current. The direction of Cl- and HCO 3 - fluxes is determined by the underlying electrochemical gradient, which is controlled by Cl- transporters and channels. Accumulating evidence suggests that active mechanisms of chloride transport across the GABAA R pore can underlie the regulation of [Cl- ]i . Measurement of Cl- / HCO 3 - -ATPase activity and Cl- transport in HEK 293FT cells expressing homomeric or heteromeric GABAA R ensembles (α2, β3, or γ2) with fluorescent dye for chloride demonstrated that receptor subtypes containing the β3 subunit show enzymatic activity and participate in GABA-mediated or ATP-dependent Cl- transport. GABA-mediated flow of Cl- ions into and out of the cells occurred for a short time period but then rapidly declined. However, Cl- ion flux was stabilized for a long time period in the presence of HCO 3 - ions. The reconstituted β3 subunit isoform, purified as a fusion protein, confirmed that β3 is critical for ATPase; however, only the triplet variant showed the full receptor function. The high sensitivity of the enzyme to γ-phosphate inhibitors led us to postulate that the β3 subunit is catalytic. Our discovery of a GABAA R type that requires ATP consumption for chloride movement provides new insight into the molecular mechanisms of inhibitory signaling.
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Affiliation(s)
| | | | - Aleksey A Moskovtsev
- Institute of General Pathology and Pathophysiology, Moscow, Russia.,Russian Medical Academy of Postdoctoral Education, Moscow, Russia
| | - Sergey G Morozov
- Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Aslan A Kubatiev
- Institute of General Pathology and Pathophysiology, Moscow, Russia.,Russian Medical Academy of Postdoctoral Education, Moscow, Russia
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30
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Uezu A, Hisey E, Kobayashi Y, Gao Y, Bradshaw TWA, Devlin P, Rodriguiz R, Tata PR, Soderling S. Essential role for InSyn1 in dystroglycan complex integrity and cognitive behaviors in mice. eLife 2019; 8:e50712. [PMID: 31829939 PMCID: PMC6944460 DOI: 10.7554/elife.50712] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023] Open
Abstract
Human mutations in the dystroglycan complex (DGC) result in not only muscular dystrophy but also cognitive impairments. However, the molecular architecture critical for the synaptic organization of the DGC in neurons remains elusive. Here, we report Inhibitory Synaptic protein 1 (InSyn1) is a critical component of the DGC whose loss alters the composition of the GABAergic synapses, excitatory/inhibitory balance in vitro and in vivo, and cognitive behavior. Association of InSyn1 with DGC subunits is required for InSyn1 synaptic localization. InSyn1 null neurons also show a significant reduction in DGC and GABA receptor distribution as well as abnormal neuronal network activity. Moreover, InSyn1 null mice exhibit elevated neuronal firing patterns in the hippocampus and deficits in fear conditioning memory. Our results support the dysregulation of the DGC at inhibitory synapses and altered neuronal network activity and specific cognitive tasks via loss of a novel component, InSyn1.
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Affiliation(s)
- Akiyoshi Uezu
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
| | - Erin Hisey
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
| | | | - Yudong Gao
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
| | - Tyler WA Bradshaw
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
| | - Patrick Devlin
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
| | - Ramona Rodriguiz
- Department of Psychiatry and Behavioral SciencesDuke University Medical SchoolDurhamUnited States
- Mouse Behavioral and Neuroendocrine Analysis Core FacilityDuke University Medical SchoolDurhamUnited States
| | | | - Scott Soderling
- Department of Cell BiologyDuke University Medical SchoolDurhamUnited States
- Department of NeurobiologyDuke University Medical SchoolDurhamUnited States
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31
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Campbell BFN, Tyagarajan SK. Cellular Mechanisms Contributing to the Functional Heterogeneity of GABAergic Synapses. Front Mol Neurosci 2019; 12:187. [PMID: 31456660 PMCID: PMC6700328 DOI: 10.3389/fnmol.2019.00187] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/19/2019] [Indexed: 11/24/2022] Open
Abstract
GABAergic inhibitory neurotransmission contributes to diverse aspects of brain development and adult plasticity, including the expression of complex cognitive processes. This is afforded for in part by the dynamic adaptations occurring at inhibitory synapses, which show great heterogeneity both in terms of upstream signaling and downstream effector mechanisms. Single-particle tracking and live imaging have revealed that complex receptor-scaffold interactions critically determine adaptations at GABAergic synapses. Super-resolution imaging studies have shown that protein interactions at synaptic sites contribute to nano-scale scaffold re-arrangements through post-translational modifications (PTMs), facilitating receptor and scaffold recruitment to synaptic sites. Additionally, plasticity mechanisms may be affected by the protein composition at individual synapses and the type of pre-synaptic input. This mini-review article examines recent discoveries of plasticity mechanisms that are operational within GABAergic synapses and discusses their contribution towards functional heterogeneity in inhibitory neurotransmission.
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Affiliation(s)
| | - Shiva K Tyagarajan
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
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32
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Duan J, Pandey S, Li T, Castellano D, Gu X, Li J, Tian Q, Lu W. Genetic Deletion of GABA A Receptors Reveals Distinct Requirements of Neurotransmitter Receptors for GABAergic and Glutamatergic Synapse Development. Front Cell Neurosci 2019; 13:217. [PMID: 31231192 PMCID: PMC6558517 DOI: 10.3389/fncel.2019.00217] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/29/2019] [Indexed: 12/13/2022] Open
Abstract
In the adult brain GABAA receptors (GABAARs) mediate the majority of synaptic inhibition that provides inhibitory balance to excitatory drive and controls neuronal output. In the immature brain GABAAR signaling is critical for neuronal development. However, the cell-autonomous role of GABAARs in synapse development remains largely unknown. We have employed the CRISPR-CAS9 technology to genetically eliminate GABAARs in individual hippocampal neurons and examined GABAergic and glutamatergic synapses. We found that development of GABAergic synapses, but not glutamatergic synapses, critically depends on GABAARs. By combining different genetic approaches, we have also removed GABAARs and two ionotropic glutamate receptors, AMPA receptors (AMPARs) and NMDA receptors (NMDARs), in single neurons and discovered a striking dichotomy. Indeed, while development of glutamatergic synapses and spines does not require signaling mediated by these receptors, inhibitory synapse formation is crucially dependent on them. Our data reveal a critical cell-autonomous role of GABAARs in inhibitory synaptogenesis and demonstrate distinct molecular mechanisms for development of inhibitory and excitatory synapses.
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Affiliation(s)
- Jingjing Duan
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States.,Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Saurabh Pandey
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Tianming Li
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - David Castellano
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Xinglong Gu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Jun Li
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Qingjun Tian
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Wei Lu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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Scott S, Aricescu AR. A structural perspective on GABA A receptor pharmacology. Curr Opin Struct Biol 2019; 54:189-197. [PMID: 31129381 DOI: 10.1016/j.sbi.2019.03.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/14/2019] [Accepted: 03/19/2019] [Indexed: 10/26/2022]
Abstract
GABAA receptors are pentameric ligand-gated chloride channels of crucial importance for the vertebrate nervous system physiology. They typically modulate the fast inhibitory neurotransmission, and represent the target receptors for major classes of drugs used in the clinic, such as benzodiazepines and general anesthetics. Recent technological progress in structural biology, in particular single-particle cryo-electron microscopy, has led to fundamental advances in understanding the detailed organization and signalling mechanisms of major GABAA receptor subtypes. This effort culminated with the high-resolution structural analysis of an intact, full-length human heteropentameric receptor, α1β3γ2, in a lipid bilayer and in complex with small molecule ligands including the commonly used benzodiazepines diazepam (Valium) and alprazolam (Xanax). These structures reveal multiple aspects of receptor activation and provide a path for rational design of subunit-specific GABAA receptor modulators.
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Affiliation(s)
- Suzanne Scott
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.
| | - Alexandru Radu Aricescu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK; Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK.
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Zimmerman AL, Kovatsis EM, Pozsgai RY, Tasnim A, Zhang Q, Ginty DD. Distinct Modes of Presynaptic Inhibition of Cutaneous Afferents and Their Functions in Behavior. Neuron 2019; 102:420-434.e8. [PMID: 30826183 PMCID: PMC6472967 DOI: 10.1016/j.neuron.2019.02.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/17/2018] [Accepted: 01/31/2019] [Indexed: 01/10/2023]
Abstract
Presynaptic inhibition (PSI) of primary sensory neurons is implicated in controlling gain and acuity in sensory systems. Here, we define circuit mechanisms and functions of PSI of cutaneous somatosensory neuron inputs to the spinal cord. We observed that PSI can be evoked by different sensory neuron populations and mediated through at least two distinct dorsal horn circuit mechanisms. Low-threshold cutaneous afferents evoke a GABAA-receptor-dependent form of PSI that inhibits similar afferent subtypes, whereas small-diameter afferents predominantly evoke an NMDA-receptor-dependent form of PSI that inhibits large-diameter fibers. Behaviorally, loss of either GABAA receptors (GABAARs) or NMDA receptors (NMDARs) in primary afferents leads to tactile hypersensitivity across skin types, and loss of GABAARs, but not NMDARs, leads to impaired texture discrimination. Post-weaning age loss of either GABAARs or NMDARs in somatosensory neurons causes systemic behavioral abnormalities, revealing critical roles of two distinct modes of PSI of somatosensory afferents in adolescence and throughout adulthood.
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Affiliation(s)
- Amanda L Zimmerman
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Eleni M Kovatsis
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Riana Y Pozsgai
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Aniqa Tasnim
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Qiyu Zhang
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA.
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Farrell JS, Nguyen QA, Soltesz I. Resolving the Micro-Macro Disconnect to Address Core Features of Seizure Networks. Neuron 2019; 101:1016-1028. [PMID: 30897354 PMCID: PMC6430140 DOI: 10.1016/j.neuron.2019.01.043] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/14/2018] [Accepted: 01/18/2019] [Indexed: 02/07/2023]
Abstract
Current drug treatments for epilepsy attempt to broadly restrict excitability to mask a symptom, seizures, with little regard for the heterogeneous mechanisms that underlie disease manifestation across individuals. Here, we discuss the need for a more complete view of epilepsy, outlining how key features at the cellular and microcircuit level can significantly impact disease mechanisms that are not captured by the most common methodology to study epilepsy, electroencephalography (EEG). We highlight how major advances in neuroscience tool development now enable multi-scale investigation of fundamental questions to resolve the currently controversial understanding of seizure networks. These findings will provide essential insight into what has emerged as a disconnect between the different levels of investigation and identify new targets and treatment options.
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Affiliation(s)
- Jordan S Farrell
- Department of Neurosurgery, Stanford University, Stanford, CA, USA.
| | - Quynh-Anh Nguyen
- Department of Neurosurgery, Stanford University, Stanford, CA, USA
| | - Ivan Soltesz
- Department of Neurosurgery, Stanford University, Stanford, CA, USA.
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Laverty D, Desai R, Uchański T, Masiulis S, Stec WJ, Malinauskas T, Zivanov J, Pardon E, Steyaert J, Miller KW, Aricescu AR. Cryo-EM structure of the human α1β3γ2 GABA A receptor in a lipid bilayer. Nature 2019; 565:516-520. [PMID: 30602789 PMCID: PMC6364807 DOI: 10.1038/s41586-018-0833-4] [Citation(s) in RCA: 210] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 12/03/2018] [Indexed: 02/04/2023]
Abstract
Type A γ-aminobutyric acid (GABAA) receptors are pentameric ligand-gated ion channels and the main drivers of fast inhibitory neurotransmission in the vertebrate nervous system1,2. Their dysfunction is implicated in a range of neurological disorders, including depression, epilepsy and schizophrenia3,4. Among the numerous assemblies that are theoretically possible, the most prevalent in the brain are the α1β2/3γ2 GABAA receptors5. The β3 subunit has an important role in maintaining inhibitory tone, and the expression of this subunit alone is sufficient to rescue inhibitory synaptic transmission in β1-β3 triple knockout neurons6. So far, efforts to generate accurate structural models for heteromeric GABAA receptors have been hampered by the use of engineered receptors and the presence of detergents7-9. Notably, some recent cryo-electron microscopy reconstructions have reported 'collapsed' conformations8,9; however, these disagree with the structure of the prototypical pentameric ligand-gated ion channel the Torpedo nicotinic acetylcholine receptor10,11, the large body of structural work on homologous homopentameric receptor variants12 and the logic of an ion-channel architecture. Here we present a high-resolution cryo-electron microscopy structure of the full-length human α1β3γ2L-a major synaptic GABAA receptor isoform-that is functionally reconstituted in lipid nanodiscs. The receptor is bound to a positive allosteric modulator 'megabody' and is in a desensitized conformation. Each GABAA receptor pentamer contains two phosphatidylinositol-4,5-bisphosphate molecules, the head groups of which occupy positively charged pockets in the intracellular juxtamembrane regions of α1 subunits. Beyond this level, the intracellular M3-M4 loops are largely disordered, possibly because interacting post-synaptic proteins are not present. This structure illustrates the molecular principles of heteromeric GABAA receptor organization and provides a reference framework for future mechanistic investigations of GABAergic signalling and pharmacology.
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Affiliation(s)
- Duncan Laverty
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK.
| | - Rooma Desai
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tomasz Uchański
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Simonas Masiulis
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - Wojciech J Stec
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Jasenko Zivanov
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Keith W Miller
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - A Radu Aricescu
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK.
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK.
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