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Jarosz ŁS, Socała K, Michalak K, Wiater A, Ciszewski A, Majewska M, Marek A, Grądzki Z, Wlaź P. The effect of psychoactive bacteria, Bifidobacterium longum Rosell®-175 and Lactobacillus rhamnosus JB-1, on brain proteome profiles in mice. Psychopharmacology (Berl) 2024; 241:925-945. [PMID: 38156998 PMCID: PMC11031467 DOI: 10.1007/s00213-023-06519-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 12/18/2023] [Indexed: 01/03/2024]
Abstract
RATIONALE The gut microbiota may play an important role in the development and functioning of the mammalian central nervous system. The assumption of the experiment was to prove that the use of probiotic bacterial strains in the diet of mice modifies the expression of brain proteins involved in metabolic and immunological processes. OBJECTIVES AND RESULTS Albino Swiss mice were administered with Bifidobacterium longum Rosell®-175 or Lactobacillus rhamnosus JB-1 every 24 h for 28 days. Protein maps were prepared from hippocampal homogenates of euthanized mice. Selected proteins that were statistically significant were purified and concentrated and identified using MALDI-TOF mass spectrometry. Among the analysed samples, 13 proteins were identified. The mean volumes of calcyon, secreted frizzled-associated protein 3, and catalase in the hippocampus of mice from both experimental groups were statistically significantly higher than in the control group. In mice supplemented with Lactobacillus rhamnosus JB-1, a lower mean volume of fragrance binding protein 2, shadow of prion protein, and glycine receptor α4 subunit was observed compared to the control. CONCLUSION The psychobiotics Bifidobacterium longum Rosell®-175 and Lactobacillus rhamnosus JB-1enhances expression of proteins involved in the activation and maturation of nerve cells, as well as myelination and homeostatic regulation of neurogenesis in mice. The tested psychobiotics cause a decrease in the expression of proteins associated with CNS development and in synaptic transmission, thereby reducing the capacity for communication between nerve cells. The results of the study indicate that psychobiotic bacteria can be used in auxiliary treatment of neurological disorders.
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Affiliation(s)
- Łukasz S Jarosz
- Department of Epizootiology and Clinic of Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Głęboka 30, 20-612, Lublin, Poland.
| | - Katarzyna Socała
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Katarzyna Michalak
- Department of Epizootiology and Clinic of Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Głęboka 30, 20-612, Lublin, Poland
| | - Adrian Wiater
- Department of Industrial and Environmental Microbiology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Artur Ciszewski
- Department of Epizootiology and Clinic of Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Głęboka 30, 20-612, Lublin, Poland
| | - Małgorzata Majewska
- Department of Industrial and Environmental Microbiology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Agnieszka Marek
- Department of Preventive Veterinary and Avian Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Głęboka 30, 20-612, Lublin, Poland
| | - Zbigniew Grądzki
- Department of Epizootiology and Clinic of Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Głęboka 30, 20-612, Lublin, Poland
| | - Piotr Wlaź
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
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2
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Do HQ, Pirayesh E, Ferreira G, Pandhare A, Gallardo ZR, Jansen M. A bupropion modulatory site in the Gloeobacter violaceus ligand-gated ion channel. Biophys J 2024:S0006-3495(24)00289-3. [PMID: 38678367 DOI: 10.1016/j.bpj.2024.04.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/27/2024] [Accepted: 04/25/2024] [Indexed: 04/29/2024] Open
Abstract
Bupropion is an atypical antidepressant and smoking cessation drug that causes adverse effects such as insomnia, irritability, and anxiety. Bupropion inhibits dopamine and norepinephrine reuptake transporters and eukaryotic cation-conducting pentameric ligand-gated ion channels, such as nicotinic acetylcholine and serotonin type 3A receptors, at clinically relevant concentrations. Here, we demonstrate that bupropion also inhibits a prokaryotic homolog of pentameric ligand-gated ion channels, the Gloeobacter violaceus ligand-gated ion channel (GLIC). Using the GLIC as a model, we used molecular docking to predict binding sites for bupropion. Bupropion was found to bind to several sites within the transmembrane domain, with the predominant site being localized to the interface between transmembrane segments M1 and M3 of two adjacent subunits. Residues W213, T214, and W217 in the first transmembrane segment, M1, and F267 and I271 in the third transmembrane segment, M3, most frequently reside within a 4 Å distance from bupropion. We then used single amino acid substitutions at these positions and two-electrode voltage-clamp recordings to determine their impact on bupropion inhibitory effects. The substitution T214F alters bupropion potency by shifting the half-maximal inhibitory concentration to a 13-fold higher value compared to wild-type GLIC. Residue T214 is found within a previously identified binding pocket for neurosteroids and lipids in the GLIC. This intersubunit binding pocket is structurally conserved and almost identical to a binding pocket described for neurosteroids in γ-aminobutyric acid type A receptors. Our data thus suggest that the T214 that lines a previously identified lipophilic binding pocket in GLIC and γ-aminobutyric acid type A receptors is also a modulatory site for bupropion interaction with the GLIC.
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Affiliation(s)
- Hoa Quynh Do
- Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Elham Pirayesh
- Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Garren Ferreira
- Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Akash Pandhare
- Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Zackary Ryan Gallardo
- Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Michaela Jansen
- Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas.
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Di Stefano D, Suganthan H, Buck L. Alfaxalone does not have long-term effects on goldfish pyramidal neuron action potential properties or GABA A receptor currents. FEBS Open Bio 2024; 14:555-573. [PMID: 38342633 PMCID: PMC10988724 DOI: 10.1002/2211-5463.13777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/30/2023] [Accepted: 01/31/2024] [Indexed: 02/13/2024] Open
Abstract
Anesthetics have varying physiological effects, but most notably alter ion channel kinetics. Alfaxalone is a rapid induction and washout neuroactive anesthetic, which potentiates γ-aminobutyric acid (GABA)-activated GABAA receptor (GABAA-R) currents. This study aims to identify any long-term effects of alfaxalone sedation on pyramidal neuron action potential and GABAA-R properties, to determine if its impact on neuronal function can be reversed in a sufficiently short timeframe to allow for same-day electrophysiological studies in goldfish brain. The goldfish (Carassius auratus) is an anoxia-tolerant vertebrate and is a useful model to study anoxia tolerance mechanisms. The results show that alfaxalone sedation did not significantly impact action potential properties. Additionally, the acute application of alfaxalone onto naive brain slices caused the potentiation of whole-cell GABAA-R current decay time and area under the curve. Following whole-animal sedation with alfaxalone, a 3-h wash of brain slices in alfaxalone-free saline, with saline exchanged every 30 min, was required to remove any potentiating impact of alfaxalone on GABAA-R whole-cell currents. These results demonstrate that alfaxalone is an effective anesthetic for same-day electrophysiological experiments with goldfish brain slices.
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Affiliation(s)
| | - Haushe Suganthan
- Department of Cell and Systems BiologyUniversity of TorontoCanada
| | - Leslie Buck
- Department of Cell and Systems BiologyUniversity of TorontoCanada
- Department of Ecology and Evolutionary BiologyUniversity of TorontoCanada
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4
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Absalom NL, Lin SXN, Liao VWY, Chua HC, Møller RS, Chebib M, Ahring PK. GABA A receptors in epilepsy: Elucidating phenotypic divergence through functional analysis of genetic variants. J Neurochem 2023. [PMID: 37621067 DOI: 10.1111/jnc.15932] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 08/26/2023]
Abstract
Normal brain function requires a tightly regulated balance between excitatory and inhibitory neurotransmissions. γ-Aminobutyric acid type A (GABAA ) receptors represent the major class of inhibitory ion channels in the mammalian brain. Dysregulation of these receptors and/or their associated pathways is strongly implicated in the pathophysiology of epilepsy. To date, hundreds of different GABAA receptor subunit variants have been associated with epilepsy, making them a prominent cause of genetically linked epilepsy. While identifying these genetic variants is crucial for accurate diagnosis and effective genetic counselling, it does not necessarily lead to improved personalised treatment options. This is because the identification of a variant does not reveal how the function of GABAA receptors is affected. Genetic variants in GABAA receptor subunits can cause complex changes to receptor properties resulting in various degrees of gain-of-function, loss-of-function or a combination of both. Understanding how variants affect the function of GABAA receptors therefore represents an important first step in the ongoing development of precision therapies. Furthermore, it is important to ensure that functional data are produced using methodologies that allow genetic variants to be classified using clinical guidelines such as those developed by the American College of Medical Genetics and Genomics. This article will review the current knowledge in the field and provide recommendations for future functional analysis of genetic GABAA receptor variants.
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Affiliation(s)
- Nathan L Absalom
- School of Science, University of Western Sydney, Sydney, New South Wales, Australia
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Susan X N Lin
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Vivian W Y Liao
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Han C Chua
- Brain and Mind Centre, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre, Filadelfia, Dianalund, Denmark
- Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Mary Chebib
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Philip K Ahring
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
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Sharmin D, Mian MY, Marcotte M, Prevot TD, Sibille E, Witkin JM, Cook JM. Synthesis and Receptor Binding Studies of α5 GABA AR Selective Novel Imidazodiazepines Targeted for Psychiatric and Cognitive Disorders. Molecules 2023; 28:4771. [PMID: 37375326 DOI: 10.3390/molecules28124771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
GABA mediates inhibitory actions through various GABAA receptor subtypes, including 19 subunits in human GABAAR. Dysregulation of GABAergic neurotransmission is associated with several psychiatric disorders, including depression, anxiety, and schizophrenia. Selective targeting of α2/3 GABAARs can treat mood and anxiety, while α5 GABAA-Rs can treat anxiety, depression, and cognitive performance. GL-II-73 and MP-III-022, α5-positive allosteric modulators have shown promising results in animal models of chronic stress, aging, and cognitive disorders, including MDD, schizophrenia, autism, and Alzheimer's disease. Described in this article is how small changes in the structure of imidazodiazepine substituents can greatly impact the subtype selectivity of benzodiazepine GABAAR. To investigate alternate and potentially more effective therapeutic compounds, modifications were made to the structure of imidazodiazepine 1 to synthesize different amide analogs. The novel ligands were screened at the NIMH PDSP against a panel of 47 receptors, ion channels, including hERG, and transporters to identify on- and off-target interactions. Any ligands with significant inhibition in primary binding were subjected to secondary binding assays to determine their Ki values. The newly synthesized imidazodiazepines were found to have variable affinities for the benzodiazepine site and negligible or no binding to any off-target profile receptors that could cause other physiological problems.
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Affiliation(s)
- Dishary Sharmin
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin Milwaukee, Milwaukee, WI 53201, USA
| | - Md Yeunus Mian
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin Milwaukee, Milwaukee, WI 53201, USA
| | - Michael Marcotte
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON M5S 2S1, Canada
| | - Thomas D Prevot
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON M5S 2S1, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Etienne Sibille
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON M5S 2S1, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5T 1R8, Canada
| | - Jeffrey M Witkin
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin Milwaukee, Milwaukee, WI 53201, USA
- Laboratory of Antiepileptic Drug Discovery, Ascension, St. Vincent, Indianapolis, IN 46260, USA
| | - James M Cook
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin Milwaukee, Milwaukee, WI 53201, USA
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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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7
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Hantsoo L, Payne JL. Towards understanding the biology of premenstrual dysphoric disorder: From genes to GABA. Neurosci Biobehav Rev 2023; 149:105168. [PMID: 37059403 PMCID: PMC10176022 DOI: 10.1016/j.neubiorev.2023.105168] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 03/10/2023] [Accepted: 04/10/2023] [Indexed: 04/16/2023]
Abstract
Premenstrual dysphoric disorder (PMDD) is a severe mood disorder, with affective symptoms that rise and fall in concert with the hormonal fluctuations of the menstrual cycle. PMDD's pathophysiology is poorly understood. This review describes recent research on potential biological contributors to PMDD, with a focus on neuroactive steroids, genetics, neuroimaging and cellular studies. Studies suggest that a key contributor is abnormal central nervous system (CNS) response to fluctuations in neuroactive steroid hormones. Imaging studies are limited but support alterations in serotonergic and GABA transmission. Genetic studies suggest heritability, yet specific genetic contributors have not been characterized. Finally, recent cutting-edge cellular studies indicate an underlying vulnerability to the effect of sex hormones at a cellular level. Overall the findings across studies do not yet fit together into a complete description of the underlying biology of PMDD. It is possible that PMDD consists of biological subtypes, and future research may benefit from a subtyping approach.
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Affiliation(s)
- Liisa Hantsoo
- Department of Psychiatry & Behavioral Sciences, The Johns Hopkins University School of Medicine, 550 N. Broadway Street, Baltimore, MD 21205, USA.
| | - Jennifer L Payne
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, PO Box 800548, Charlottesville, VA 22908, USA
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Darwish M, Hattori S, Nishizono H, Miyakawa T, Yachie N, Takao K. Comprehensive behavioral analyses of mice with a glycine receptor alpha 4 deficiency. Mol Brain 2023; 16:44. [PMID: 37217969 DOI: 10.1186/s13041-023-01033-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 05/04/2023] [Indexed: 05/24/2023] Open
Abstract
Glycine receptors (GlyRs) are ligand-gated chloride channels comprising alpha (α1-4) and β subunits. The GlyR subunits play major roles in the mammalian central nervous system, ranging from regulating simple sensory information to modulating higher-order brain function. Unlike the other GlyR subunits, GlyR α4 receives relatively little attention because the human ortholog lacks a transmembrane domain and is thus considered a pseudogene. A recent genetic study reported that the GLRA4 pseudogene locus on the X chromosome is potentially involved in cognitive impairment, motor delay and craniofacial anomalies in humans. The physiologic roles of GlyR α4 in mammal behavior and its involvement in disease, however, are not known. Here we examined the temporal and spatial expression profile of GlyR α4 in the mouse brain and subjected Glra4 mutant mice to a comprehensive behavioral analysis to elucidate the role of GlyR α4 in behavior. The GlyR α4 subunit was mainly enriched in the hindbrain and midbrain, and had relatively lower expression in the thalamus, cerebellum, hypothalamus, and olfactory bulb. In addition, expression of the GlyR α4 subunit gradually increased during brain development. Glra4 mutant mice exhibited a decreased amplitude and delayed onset of the startle response compared with wild-type littermates, and increased social interaction in the home cage during the dark period. Glra4 mutants also had a low percentage of entries into open arms in the elevated plus-maze test. Although mice with GlyR α4 deficiency did not show motor and learning abnormalities reported to be associated in human genomics studies, they exhibited behavioral changes in startle response and social and anxiety-like behavior. Our data clarify the spatiotemporal expression pattern of the GlyR α4 subunit and suggest that glycinergic signaling modulates social, startle, and anxiety-like behaviors in mice.
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Affiliation(s)
- Mohamed Darwish
- Department of Behavioral Physiology, Graduate School of Innovative Life Science, University of Toyama, Toyama, Japan
- Department of Biochemistry, Faculty of Pharmacy, Cairo University, Cairo, Egypt
- Synthetic Biology Division, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Satoko Hattori
- Division of Systems Medical Science, Center for Comprehensive Medical Science, Fujita Health University, Aichi, Toyoake, Japan
| | - Hirofumi Nishizono
- Medical Research Institute, Kanazawa Medical University, Kahoku, Ishikawa, Japan
| | - Tsuyoshi Miyakawa
- Division of Systems Medical Science, Center for Comprehensive Medical Science, Fujita Health University, Aichi, Toyoake, Japan
| | - Nozomu Yachie
- Synthetic Biology Division, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
- School of Biomedical Engineering, The University of British Columbia, Vancouver, Canada
| | - Keizo Takao
- Department of Behavioral Physiology, Graduate School of Innovative Life Science, University of Toyama, Toyama, Japan.
- Department of Behavioral Physiology, Faculty of Medicine, University of Toyama, Toyama, Japan.
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan.
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9
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Xiang T, Liao J, Cai Y, Fan M, Li C, Zhang X, Li H, Chen Y, Pan J. Impairment of GABA inhibition in insomnia disorders: Evidence from the peripheral blood system. Front Psychiatry 2023; 14:1134434. [PMID: 36846238 PMCID: PMC9947704 DOI: 10.3389/fpsyt.2023.1134434] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 01/25/2023] [Indexed: 02/11/2023] Open
Abstract
AIM To explore the change characteristics and related factors of various indexes of GABAergic system in peripheral blood of patients with insomnia disorder. METHODS In this study, a total of 30 patients who met the DSM-5 diagnostic criteria for insomnia disorder and 30 normal controls were included. All subjects had a structured clinical interview with the Brief International Neuropsychiatric Disorder Interview, and PSQI was used to evaluate the sleep status of the subjects. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum γ-aminobutyric acid (GABA), and RT-PCR was used to detect GABAA receptor α1 and α2 subunit mRNA. All data were statistically analyzed using SPSS 23.0. RESULTS Compared with the normal control group, the mRNA levels of GABAA receptor α1 and α2 subunits in the insomnia disorder group were significantly lower, but there was no significant difference in the serum GABA levels between the two groups. And in the insomnia disorder group, there was no significant correlation between the GABA levels and the mRNA expression levels of α1 and α2 subunits of GABAA receptors. Although no significant correlation was found between PSQI and serum levels of these two subunit mRNAs, its component factors sleep quality and sleep time were negatively correlated with GABAA receptor α1 subunit mRNA levels, and daytime function was inversely correlated with GABAA receptor α2 subunit mRNA levels. CONCLUSION The inhibitory function of serum GABA in patients with insomnia may be impaired, and the decreased expression levels of GABAA receptor α1 and α2 subunit mRNA may become a reliable indicator of insomnia disorder.
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Affiliation(s)
- Ting Xiang
- Sleep Medical Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China.,Department of Psychiatry, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Jiwu Liao
- Department of Psychiatry, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Yixian Cai
- Sleep Medical Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China.,Department of Psychiatry, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Mei Fan
- Sleep Medical Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China.,Department of Psychiatry, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Congrui Li
- Department of Psychiatry, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Xiaotao Zhang
- Sleep Medical Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Hongyao Li
- Sleep Medical Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Yushan Chen
- Sleep Medical Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Jiyang Pan
- Sleep Medical Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China.,Department of Psychiatry, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
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Gao Q, Sun W, Wang YR, Li ZF, Zhao F, Geng XW, Xu KY, Chen D, Liu K, Xing Y, Liu W, Wei S. Role of allopregnanolone-mediated γ-aminobutyric acid A receptor sensitivity in the pathogenesis of premenstrual dysphoric disorder: Toward precise targets for translational medicine and drug development. Front Psychiatry 2023; 14:1140796. [PMID: 36937732 PMCID: PMC10017536 DOI: 10.3389/fpsyt.2023.1140796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/09/2023] [Indexed: 03/06/2023] Open
Abstract
Premenstrual dysphoric disorder (PMDD) can be conceptualized as a disorder of suboptimal sensitivity to neuroactive steroid hormones. Its core symptoms (emotional instability, irritability, depression, and anxiety) are related to the increase of stress sensitivity due to the fluctuation of hormone level in luteal phase of the menstrual cycle. In this review, we describe the emotional regulatory effect of allopregnanolone (ALLO), and summarize the relationship between ALLO and γ-aminobutyric acid A (GABAA) receptor subunits based on rodent experiments and clinical observations. A rapid decrease in ALLO reduces the sensitivity of GABAA receptor, and reduces the chloride influx, hindered the inhibitory effect of GABAergic neurons on pyramidal neurons, and then increased the excitability of pyramidal neurons, resulting in PMDD-like behavior. Finally, we discuss in depth the treatment of PMDD with targeted GABAA receptors, hoping to find a precise target for drug development and subsequent clinical application. In conclusion, PMDD pathophysiology is rooted in GABAA receptor sensitivity changes caused by rapid changes in ALLO levels. Targeting GABAA receptors may alleviate the occurrence of PMDD.
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Affiliation(s)
- Qian Gao
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, China
- Chinese Medicine and Brain Science Core Facility, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Wei Sun
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yue-Rui Wang
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, China
- Chinese Medicine and Brain Science Core Facility, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Zi-Fa Li
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Feng Zhao
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Xi-Wen Geng
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, China
- Chinese Medicine and Brain Science Core Facility, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Kai-Yong Xu
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Dan Chen
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Kun Liu
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, China
- Chinese Medicine and Brain Science Core Facility, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Ying Xing
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, China
- Chinese Medicine and Brain Science Core Facility, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Wei Liu
- Department of Encephalopathy, The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
- Wei Liu,
| | - Sheng Wei
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, China
- Chinese Medicine and Brain Science Core Facility, Shandong University of Traditional Chinese Medicine, Jinan, China
- *Correspondence: Sheng Wei,
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11
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Williams A, Cooney E, Segal G, Narayanan S, Morand M, Agadi S. GABRG1 variant as a potential novel cause of epileptic encephalopathy, hypotonia, and global developmental delay. Am J Med Genet A 2022; 188:3546-3549. [PMID: 36121006 DOI: 10.1002/ajmg.a.62969] [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: 08/10/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 01/31/2023]
Abstract
Epileptic encephalopathies (EEs) are severe brain disorders with excessive ictal (seizure) and interictal (electrographic epileptiform discharges) activity in developing brain which may result in progressive cognitive and neuropsychological deterioration. In contrast to regular epilepsy where the treatment goal is to prevent the seizure (ictal) recurrence, in patients with EE the goal is to treat both ictal as well as interictal activity to prevent further progression. With the introduction of genetic sequencing technologies over the past 20 years, there is growing recognition of the genetic basis of EE, with the majority due to monogenic causes. Monogenic etiologies of EE include pathogenic variants in the γ-aminobutyric acid type A receptor (GABA-A) encoding gene family. We present a 2-year-old patient with EE, hypotonia, and global developmental delays. Clinical trio exome sequencing showed a novel, de novo variant in GABRG1. GABRG1 encodes the γ1 subunit of the GABA-A receptor. To date, there has not been an association of EE with pathogenic variants in GABRG1. This variant is predicted to be damaging to protein structure and function, and the patient's phenotype is similar to those with pathogenic variants in other members of the GABA-A receptor encoding gene family.
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Affiliation(s)
- Aaron Williams
- University of Texas Medical Branch School of Medicine, Galveston, Texas, USA
| | - Erin Cooney
- University of Texas Medical Branch School of Medicine, Galveston, Texas, USA.,Division of Medical Genetics and Metabolism, Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Gabrielle Segal
- University of Texas Medical Branch School of Medicine, Galveston, Texas, USA
| | - Swetha Narayanan
- University of Texas Medical Branch School of Medicine, Galveston, Texas, USA.,Division of Medical Genetics and Metabolism, Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Megan Morand
- University of Texas Medical Branch School of Medicine, Galveston, Texas, USA.,Division of Medical Genetics and Metabolism, Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Satish Agadi
- University of Texas Medical Branch School of Medicine, Galveston, Texas, USA.,Division of Neurology, Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
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12
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McCoy AM, Prevot TD, Mian MY, Cook JM, Frazer A, Sibille EL, Carreno FR, Lodge DJ. Positive Allosteric Modulation of α5-GABAA Receptors Reverses Stress-Induced Alterations in Dopamine System Function and Prepulse Inhibition of Startle. Int J Neuropsychopharmacol 2022; 25:688-698. [PMID: 35732272 PMCID: PMC9380714 DOI: 10.1093/ijnp/pyac035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/24/2022] [Accepted: 06/21/2022] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Up to 64% of patients diagnosed with posttraumatic stress disorder (PTSD) experience psychosis, likely attributable to aberrant dopamine neuron activity. We have previously demonstrated that positive allosteric modulators of α5-GABAARs can selectively decrease hippocampal activity and reverse psychosis-like physiological and behavioral alterations in a rodent model used to study schizophrenia; however, whether this approach translates to a PTSD model remains to be elucidated. METHODS We utilized a 2-day inescapable foot shock (IS) procedure to induce stress-related pathophysiology in male Sprague-Dawley rats. We evaluated the effects of intra-ventral hippocampus (vHipp) administration GL-II-73, an α5-GABAAR, or viral overexpression of the α5 subunit, using in vivo electrophysiology and behavioral measures in control and IS-treated rats. RESULTS IS significantly increased ventral tegmental area dopamine neuron population activity, or the number of dopamine neurons firing spontaneously (n = 6; P = .016), consistent with observation in multiple rodent models used to study psychosis. IS also induced deficits in sensorimotor gating, as measured by reduced prepulse inhibition of startle (n = 12; P = .039). Interestingly, intra-vHipp administration of GL-II-73 completely reversed IS-induced increases in dopamine neuron population activity (n = 6; P = .024) and deficits in prepulse inhibition (n = 8; P = .025), whereas viral overexpression of the α5 subunit in the vHipp was not effective. CONCLUSIONS Our results demonstrate that pharmacological intervention augmenting α5-GABAAR function, but not α5 overexpression in itself, can reverse stress-induced deficits related to PTSD in a rodent model, providing a potential site of therapeutic intervention to treat comorbid psychosis in PTSD.
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Affiliation(s)
- Alexandra M McCoy
- Correspondence: Alexandra M. McCoy, BS, 7703 Floyd Curl Drive, MC 7764, San Antonio, TX, 78229, USA ()
| | - Thomas D Prevot
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Md Yenus Mian
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - James M Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Alan Frazer
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, Texas, USA,South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, Texas, USA
| | - Etienne L Sibille
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada,Department of Psychiatry, University of Toronto, Toronto, ON, Canada,Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Flavia R Carreno
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, Texas, USA,South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, Texas, USA
| | - Daniel J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, San Antonio, Texas, USA,South Texas Veterans Health Care System, Audie L. Murphy Division, San Antonio, Texas, USA
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13
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Sivakumar D, Ramli R. GABAergic signalling in modulation of dental pain. Eur J Pharmacol 2022; 924:174958. [DOI: 10.1016/j.ejphar.2022.174958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/07/2022] [Accepted: 04/11/2022] [Indexed: 11/30/2022]
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14
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Fujie Y, Liu G, Ozoe F, Ozoe Y. Structural insights into the interaction between gabazine (SR-95531) and Laodelphax striatellus GABA receptors. JOURNAL OF PESTICIDE SCIENCE 2022; 47:78-85. [PMID: 35800394 PMCID: PMC9184248 DOI: 10.1584/jpestics.d22-007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/13/2022] [Indexed: 06/15/2023]
Abstract
γ-Aminobutyric acid receptors (GABARs) mediate fast inhibitory neurotransmission and are targets for insecticides. GABARs are composed of five subunits, the composition of which dictates the pharmacological characteristics of GABARs. Both competitive and noncompetitive GABAR antagonists can be used as insecticides. Gabazine is a potent competitive antagonist of mammalian α1β2γ2 GABARs; however, it is less potent against insect GABARs. To explore how gabazine interacts with GABARs, we examined whether the sensitivity of the small brown planthopper (Laodelphax striatellus) RDL GABAR (LsRDLR) to gabazine is increased when its amino acid residues are substituted with α1β2γ2 GABAR residues. In the results, two of the generated mutants showed enhanced gabazine sensitivity. Docking simulations of gabazine using LsRDLR homology models and an α1β2γ2 GABAR cryo-EM structure revealed that the accommodation of gabazine into the "aromatic box" in the orthosteric site lowered the binding energy. This information may help in designing GABAR-targeting insecticides with novel modes of action.
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Affiliation(s)
- Yuki Fujie
- Faculty of Life and Environmental Sciences, Shimane University, Matsue, Shimane 690–8504, Japan
| | - Genyan Liu
- Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan, Hubei 430205, People’s Republic of China
| | - Fumiyo Ozoe
- Interdisciplinary Institute for Science Research, Organization for Research and Academic Information, Shimane University, Matsue, Shimane 690–8504, Japan
| | - Yoshihisa Ozoe
- Faculty of Life and Environmental Sciences, Shimane University, Matsue, Shimane 690–8504, Japan
- Interdisciplinary Institute for Science Research, Organization for Research and Academic Information, Shimane University, Matsue, Shimane 690–8504, Japan
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15
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Why won't it stop? The dynamics of benzodiazepine resistance in status epilepticus. Nat Rev Neurol 2022; 18:428-441. [PMID: 35538233 DOI: 10.1038/s41582-022-00664-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/19/2022] [Indexed: 11/08/2022]
Abstract
Status epilepticus is a life-threatening neurological emergency that affects both adults and children. Approximately 36% of episodes of status epilepticus do not respond to the current preferred first-line treatment, benzodiazepines. The proportion of episodes that are refractory to benzodiazepines is higher in low-income and middle-income countries (LMICs) than in high-income countries (HICs). Evidence suggests that longer episodes of status epilepticus alter brain physiology, thereby contributing to the emergence of benzodiazepine resistance. Such changes include alterations in GABAA receptor function and in the transmembrane gradient for chloride, both of which erode the ability of benzodiazepines to enhance inhibitory synaptic signalling. Often, current management guidelines for status epilepticus do not account for these duration-related changes in pathophysiology, which might differentially impact individuals in LMICs, where the average time taken to reach medical attention is longer than in HICs. In this Perspective article, we aim to combine clinical insights and the latest evidence from basic science to inspire a new, context-specific approach to efficiently managing status epilepticus.
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16
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Koniuszewski F, Vogel FD, Bampali K, Fabjan J, Seidel T, Scholze P, Schmiedhofer PB, Langer T, Ernst M. Molecular Mingling: Multimodal Predictions of Ligand Promiscuity in Pentameric Ligand-Gated Ion Channels. Front Mol Biosci 2022; 9:860246. [PMID: 35615739 PMCID: PMC9124788 DOI: 10.3389/fmolb.2022.860246] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 03/28/2022] [Indexed: 01/23/2023] Open
Abstract
Background: Human pentameric ligand-gated ion channels (pLGICs) comprise nicotinic acetylcholine receptors (nAChRs), 5-hydroxytryptamine type 3 receptors (5-HT3Rs), zinc-activated channels (ZAC), γ-aminobutyric acid type A receptors (GABAARs) and glycine receptors (GlyRs). They are recognized therapeutic targets of some of the most prescribed drugs like general anesthetics, anxiolytics, smoking cessation aids, antiemetics and many more. Currently, approximately 100 experimental structures of pLGICs with ligands bound exist in the protein data bank (PDB). These atomic-level 3D structures enable the generation of a comprehensive binding site inventory for the superfamily and the in silico prediction of binding site properties. Methods: A panel of high throughput in silico methods including pharmacophore screening, conformation analysis and descriptor calculation was applied to a selection of allosteric binding sites for which in vitro screens are lacking. Variant abundance near binding site forming regions and computational docking complement the approach. Results: The structural data reflects known and novel binding sites, some of which may be unique to individual receptors, while others are broadly conserved. The membrane spanning domain, comprising four highly conserved segments, contains ligand interaction sites for which in vitro assays suitable for high throughput screenings are critically lacking. This is also the case for structurally more variable novel sites in the extracellular domain. Our computational results suggest that the phytocannabinoid Δ9-tetrahydrocannabinol (Δ9-THC) can utilize multiple pockets which are likely to exist on most superfamily members. Conclusion: With this study, we explore the potential for polypharmacology among pLGICs. Our data suggest that ligands can display two forms of promiscuity to an extent greater than what has been realized: 1) Ligands can interact with homologous sites in many members of the superfamily, which bears toxicological relevance. 2) Multiple pockets in distinct localizations of individual receptor subtypes share common ligands, which counteracts efforts to develop selective agents. Moreover, conformational states need to be considered for in silico drug screening, as certain binding sites display considerable flexibility. In total, this work contributes to a better understanding of polypharmacology across pLGICs and provides a basis for improved structure guided in silico drug development and drug derisking.
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Affiliation(s)
- Filip Koniuszewski
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - Florian D. Vogel
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - Konstantina Bampali
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - Jure Fabjan
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - Thomas Seidel
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - Philip B. Schmiedhofer
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - Thierry Langer
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Margot Ernst
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University Vienna, Vienna, Austria
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17
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Ashton MK, Rueda AVL, Ho AM, Noor Aizin NABM, Sharma H, Dodd PR, Stadlin A, Camarini R. Sex differences in GABA A receptor subunit transcript expression are mediated by genotype in subjects with alcohol-related cirrhosis of the liver. GENES, BRAIN, AND BEHAVIOR 2022; 21:e12785. [PMID: 35301805 PMCID: PMC9744570 DOI: 10.1111/gbb.12785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 11/29/2022]
Abstract
Male and female human subjects show contrasting propensities to misuse drugs of addiction, including alcohol. These differences lead to different psychological and neurological consequences, such as the likelihood of developing dependence. The pattern and extent of brain damage in alcohol-use disorder cases also varies with comorbid disease. To explore mechanisms that might underlie these outcomes, we used autopsy tissue to determine mRNA transcript expression in relation to genotype for two GABAA receptor subunit genes. We used quantitative Real-Time PCR to measure GABRA6 and GABRA2 mRNA concentrations in dorsolateral prefrontal and primary motor cortices of alcohol-use disorder subjects and controls of both sexes with and without liver disease who had been genotyped for these GABAA receptor subunit genes. Cirrhotic alcohol-use disorder cases had significantly higher expression of GABRA6 and GABRA2 transcripts than either controls or non-cirrhotic alcohol-use disorder cases. Differences were observed between sexes, genotypes and brain regions. We show that sex differences in subjects with GABRA6 and GABRA2 variants may contribute to differences in susceptibility to alcohol-use disorder and alcohol-induced cirrhosis.
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Affiliation(s)
- Madeline K. Ashton
- School of Chemistry and Molecular BiosciencesThe University of QueenslandBrisbaneQueenslandAustralia
| | - André V. L. Rueda
- School of Chemistry and Molecular BiosciencesThe University of QueenslandBrisbaneQueenslandAustralia
- Departamento de Farmacologia, ICBUniversidade de São PauloSão PauloBrazil
| | - Ada M.‐C. Ho
- School of Chemistry and Molecular BiosciencesThe University of QueenslandBrisbaneQueenslandAustralia
- Department of Psychiatry and PsychologyMayo ClinicRochesterMinnesotaUSA
| | - Noradibah Arina Binte M. Noor Aizin
- School of Chemistry and Molecular BiosciencesThe University of QueenslandBrisbaneQueenslandAustralia
- Vela Research Singapore Pte LtdThe KendallSingapore
| | - Hansa Sharma
- School of Chemistry and Molecular BiosciencesThe University of QueenslandBrisbaneQueenslandAustralia
| | - Peter R. Dodd
- School of Chemistry and Molecular BiosciencesThe University of QueenslandBrisbaneQueenslandAustralia
| | | | - Rosana Camarini
- Departamento de Farmacologia, ICBUniversidade de São PauloSão PauloBrazil
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18
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Barnaby W, Dorman Barclay HE, Nagarkar A, Perkins M, Teicher G, Trapani JG, Downes GB. GABAA α subunit control of hyperactive behavior in developing zebrafish. Genetics 2022; 220:6519832. [PMID: 35106556 PMCID: PMC8982038 DOI: 10.1093/genetics/iyac011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 01/03/2022] [Indexed: 02/04/2023] Open
Abstract
GABAA receptors mediate rapid responses to the neurotransmitter gamma-aminobutyric acid and are robust regulators of the brain and spinal cord neural networks that control locomotor behaviors, such as walking and swimming. In developing zebrafish, gross pharmacological blockade of these receptors causes hyperactive swimming, which is also a feature of many zebrafish epilepsy models. Although GABAA receptors are important to control locomotor behavior, the large number of subunits and homeostatic compensatory mechanisms have challenged efforts to determine subunit-selective roles. To address this issue, we mutated each of the 8 zebrafish GABAA α subunit genes individually and in pairs using a CRISPR-Cas9 somatic inactivation approach and, then, we examined the swimming behavior of the mutants at 2 developmental stages, 48 and 96 h postfertilization. We found that disrupting the expression of specific pairs of subunits resulted in different abnormalities in swimming behavior at 48 h postfertilization. Mutation of α4 and α5 selectively resulted in longer duration swimming episodes, mutations in α3 and α4 selectively caused excess, large-amplitude body flexions (C-bends), and mutation of α3 and α5 resulted in increases in both of these measures of hyperactivity. At 96 h postfertilization, hyperactive phenotypes were nearly absent, suggesting that homeostatic compensation was able to overcome the disruption of even multiple subunits. Taken together, our results identify subunit-selective roles for GABAA α3, α4, and α5 in regulating locomotion. Given that these subunits exhibit spatially restricted expression patterns, these results provide a foundation to identify neurons and GABAergic networks that control discrete aspects of locomotor behavior.
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Affiliation(s)
- Wayne Barnaby
- Neuroscience and Behavior Graduate Program, University of Massachusetts Amherst, Amherst, MA 01003, USA,Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | | | - Akanksha Nagarkar
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Matthew Perkins
- Biology Department and Neuroscience Program, Amherst College, Amherst, MA 01002, USA
| | - Gregory Teicher
- Molecular and Cellular Biology Program, University of Massachusetts Amherst, Amherst, MA 01003, USA,Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Josef G Trapani
- Neuroscience and Behavior Graduate Program, University of Massachusetts Amherst, Amherst, MA 01003, USA,Biology Department and Neuroscience Program, Amherst College, Amherst, MA 01002, USA
| | - Gerald B Downes
- Neuroscience and Behavior Graduate Program, University of Massachusetts Amherst, Amherst, MA 01003, USA,Molecular and Cellular Biology Program, University of Massachusetts Amherst, Amherst, MA 01003, USA,Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA,Corresponding author: Biology Department, Neuroscience and Behavior Graduate Program, and Molecular and Cellular Biology Graduate Program, 611 North Pleasant St., Morrill Science Center, Building 4 North, Amherst, MA 01003, USA.
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19
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Lipovsek M, Marcovich I, Elgoyhen AB. The Hair Cell α9α10 Nicotinic Acetylcholine Receptor: Odd Cousin in an Old Family. Front Cell Neurosci 2021; 15:785265. [PMID: 34867208 PMCID: PMC8634148 DOI: 10.3389/fncel.2021.785265] [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: 09/28/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAChRs) are a subfamily of pentameric ligand-gated ion channels with members identified in most eumetazoan clades. In vertebrates, they are divided into three subgroups, according to their main tissue of expression: neuronal, muscle and hair cell nAChRs. Each receptor subtype is composed of different subunits, encoded by paralogous genes. The latest to be identified are the α9 and α10 subunits, expressed in the mechanosensory hair cells of the inner ear and the lateral line, where they mediate efferent modulation. α9α10 nAChRs are the most divergent amongst all nicotinic receptors, showing marked differences in their degree of sequence conservation, their expression pattern, their subunit co-assembly rules and, most importantly, their functional properties. Here, we review recent advances in the understanding of the structure and evolution of nAChRs. We discuss the functional consequences of sequence divergence and conservation, with special emphasis on the hair cell α9α10 receptor, a seemingly distant cousin of neuronal and muscle nicotinic receptors. Finally, we highlight potential links between the evolution of the octavolateral system and the extreme divergence of vertebrate α9α10 receptors.
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Affiliation(s)
- Marcela Lipovsek
- Ear Institute, Faculty of Brain Sciences, University College London, London, United Kingdom
| | - Irina Marcovich
- Departments of Otolaryngology & Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Ana Belén Elgoyhen
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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20
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Janzen D, Slavik B, Zehe M, Sotriffer C, Loos HM, Buettner A, Villmann C. Sesquiterpenes and sesquiterpenoids harbor modulatory allosteric potential and affect inhibitory GABA A receptor function in vitro. J Neurochem 2021; 159:101-115. [PMID: 34263932 DOI: 10.1111/jnc.15469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/11/2021] [Accepted: 07/07/2021] [Indexed: 11/29/2022]
Abstract
Naturally occurring compounds such as sesquiterpenes and sesquiterpenoids (SQTs) have been shown to modulate GABAA receptors (GABAA Rs). In this study, the modulatory potential of 11 SQTs at GABAA Rs was analyzed to characterize their potential neurotropic activity. Transfected HEK293 cells and primary hippocampal neurons were functionally investigated using electrophysiological whole-cell recordings. Significantly different effects of β-caryophyllene and α-humulene, as well as their respective derivatives β-caryolanol and humulol, were observed in the HEK293 cell system. In neurons, the concomitant presence of phasic and tonic GABAA R configurations accounts for differences in receptor modulation by SQTs. The in vivo presence of the γ2 and δ subunits is important for SQT modulation. While phasic GABAA receptors in hippocampal neurons exhibited significantly altered GABA-evoked current amplitudes in the presence of humulol and guaiol, negative allosteric potential at recombinantly expressed α1 β2 γ2 receptors was only verified for humolol. Modeling and docking studies provided support for the binding of SQTs to the neurosteroid-binding site of the GABAA R localized between transmembrane segments 1 and 3 at the (+ α)-(- α) interface. In sum, differences in the modulation of GABAA R isoforms between SQTs were identified. Another finding is that our results provide an indication that nutritional digestion affects the neurotropic potential of natural compounds.
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Affiliation(s)
- Dieter Janzen
- Institute for Clinical Neurobiology, University Hospital, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Benedikt Slavik
- Chair of Aroma and Smell Research, Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Markus Zehe
- Institute of Pharmacy and Food Chemistry, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Christoph Sotriffer
- Institute of Pharmacy and Food Chemistry, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Helene M Loos
- Chair of Aroma and Smell Research, Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Fraunhofer Institute for Process Engineering and Packaging IVV, Freising, Germany
| | - Andrea Buettner
- Chair of Aroma and Smell Research, Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Fraunhofer Institute for Process Engineering and Packaging IVV, Freising, Germany
| | - Carmen Villmann
- Institute for Clinical Neurobiology, University Hospital, Julius-Maximilians-University Würzburg, Würzburg, Germany
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21
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Kłopotowski K, Czyżewska MM, Mozrzymas JW. Glycine substitution of α1F64 residue at the loop D of GABA A receptor impairs gating - Implications for importance of binding site-channel gate linker rigidity. Biochem Pharmacol 2021; 192:114668. [PMID: 34216603 DOI: 10.1016/j.bcp.2021.114668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/27/2021] [Accepted: 06/28/2021] [Indexed: 12/29/2022]
Abstract
GABAA receptors (GABAARs) play a crucial role in mediating inhibition in adult mammalian brains. In the recent years, an impressive progress in revealing the static structure of GABAARs was achieved but the molecular mechanisms underlying their conformational transitions remain elusive. Phenylalanine 64 (α1F64) is located at the loop D of the orthosteric binding site of GABAAR and was found to directly interact with GABA molecule. Mutations of α1F64 were demonstrated to affect not only binding but also some gating properties. Loop D is a rigid β strand which seems to be particularly suitable to convey activatory signaling from the ligand binding site (LBS) to the gate at the channel pore. To test this scenario, we have investigated the substitution of α1F64 with glycine, the smallest amino acid, widely recognized as a rigidity "reducer" of protein structures. To this end, we assessed the impact of the α1F64G mutation in the α1β2γ2L type of GABAARs on gating properties by analyzing both macroscopic responses to rapid agonist applications and single-channel currents. We found that this substitution dramatically altered all gating features of the receptor (opening/closing, preactivation and desensitization) which contrasts with markedly weaker effects of previously considered substitutions (α1F64L and α1F64A). In particular, α1F64G mutation practically abolished the desensitization process. At the same time, the α1F64G mutant maintained gating integrity manifested as single-channel activity in the form of clusters. We conclude that rigidity of the loop D plays a crucial role in conveying the activation signal from the LBS to the channel gate.
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Affiliation(s)
- Karol Kłopotowski
- Wroclaw Medical University, Department of Biophysics and Neuroscience, Chalubinskiego 3A, Wroclaw, Dolnośląskie PL 50-368, +48 71 784 15 51, Poland.
| | - Marta M Czyżewska
- Wroclaw Medical University, Department of Biophysics and Neuroscience, Chalubinskiego 3A, Wroclaw, Dolnośląskie PL 50-368, +48 71 784 15 51, Poland
| | - Jerzy W Mozrzymas
- Wroclaw Medical University, Department of Biophysics and Neuroscience, Chalubinskiego 3A, Wroclaw, Dolnośląskie PL 50-368, +48 71 784 15 51, Poland.
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22
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Thomas JT, Spady BL, Munday PL, Watson SA. The role of ligand-gated chloride channels in behavioural alterations at elevated CO2 in a cephalopod. J Exp Biol 2021; 224:269059. [PMID: 34100547 DOI: 10.1242/jeb.242335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 05/30/2021] [Indexed: 11/20/2022]
Abstract
Projected future carbon dioxide (CO2) levels in the ocean can alter marine animal behaviours. Disrupted functioning of γ-aminobutyric acid type A (GABAA) receptors (ligand-gated chloride channels) is suggested to underlie CO2-induced behavioural changes in fish. However, the mechanisms underlying behavioural changes in marine invertebrates are poorly understood. We pharmacologically tested the role of GABA-, glutamate-, acetylcholine- and dopamine-gated chloride channels in CO2-induced behavioural changes in a cephalopod, the two-toned pygmy squid (Idiosepius pygmaeus). We exposed squid to ambient (∼450 µatm) or elevated (∼1000 µatm) CO2 for 7 days. Squid were treated with sham, the GABAA receptor antagonist gabazine or the non-specific GABAA receptor antagonist picrotoxin, before measurement of conspecific-directed behaviours and activity levels upon mirror exposure. Elevated CO2 increased conspecific-directed attraction and aggression, as well as activity levels. For some CO2-affected behaviours, both gabazine and picrotoxin had a different effect at elevated compared with ambient CO2, providing robust support for the GABA hypothesis within cephalopods. In another behavioural trait, picrotoxin but not gabazine had a different effect in elevated compared with ambient CO2, providing the first pharmacological evidence, in fish and marine invertebrates, for altered functioning of ligand-gated chloride channels, other than the GABAAR, underlying CO2-induced behavioural changes. For some other behaviours, both gabazine and picrotoxin had a similar effect in elevated and ambient CO2, suggesting altered function of ligand-gated chloride channels was not responsible for these CO2-induced changes. Multiple mechanisms may be involved, which could explain the variability in the CO2 and drug treatment effects across behaviours.
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Affiliation(s)
- Jodi T Thomas
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Blake L Spady
- Coral Reef Watch, National Oceanic and Atmospheric Administration, College Park, MD 20740, USA.,ReefSense Pty Ltd., Cranbrook, QLD 4814, Australia
| | - Philip L Munday
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Sue-Ann Watson
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia.,Biodiversity and Geosciences Program, Museum of Tropical Queensland, Queensland Museum Network, Townsville, QLD 4810, Australia
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23
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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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24
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Maingret F, Groc L. Characterization of the Functional Cross-Talk between Surface GABA A and Dopamine D5 Receptors. Int J Mol Sci 2021; 22:ijms22094867. [PMID: 34064454 PMCID: PMC8125140 DOI: 10.3390/ijms22094867] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 01/17/2023] Open
Abstract
The γ-aminobutyric acid type A receptor (GABAAR) plays a major role in fast inhibitory synaptic transmission and is highly regulated by the neuromodulator dopamine. In this aspect, most of the attention has been focused on the classical intracellular signaling cascades following dopamine G-protein-coupled receptor activation. Interestingly, the GABAAR and dopamine D5 receptor (D5R) have been shown to physically interact in the hippocampus, but whether a functional cross-talk occurs is still debated. In the present study, we use a combination of imaging and single nanoparticle tracking in live hippocampal neurons to provide evidence that GABAARs and D5Rs form dynamic surface clusters. Disrupting the GABAAR–D5R interaction with a competing peptide leads to an increase in the diffusion coefficient and the explored area of both receptors, and a drop in immobile synaptic GABAARs. By means of patch-clamp recordings, we show that this fast lateral redistribution of surface GABAARs correlates with a robust depression in the evoked GABAergic currents. Strikingly, it also shifts in time the expression of long-term potentiation at glutamatergic synapses. Together, our data both set the plasma membrane as the primary stage of a functional interplay between GABAAR and D5R, and uncover a non-canonical role in regulating synaptic transmission.
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Affiliation(s)
- François Maingret
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, UMR 5297, 33076 Bordeaux, France;
- CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33076 Bordeaux, France
- Correspondence:
| | - Laurent Groc
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, UMR 5297, 33076 Bordeaux, France;
- CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33076 Bordeaux, France
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25
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Takamura Y, Kakuta H. In Vivo Receptor Visualization and Evaluation of Receptor Occupancy with Positron Emission Tomography. J Med Chem 2021; 64:5226-5251. [PMID: 33905258 DOI: 10.1021/acs.jmedchem.0c01714] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Positron emission tomography (PET) is useful for noninvasive in vivo visualization of disease-related receptors, for evaluation of receptor occupancy to determine an appropriate drug dosage, and for proof-of-concept of drug candidates in translational research. For these purposes, the specificity of the PET tracer for the target receptor is critical. Here, we review work in this area, focusing on the chemical structures of reported PET tracers, their Ki/Kd values, and the physical properties relevant to target receptor selectivity. Among these physical properties, such as cLogP, cLogD, molecular weight, topological polar surface area, number of hydrogen bond donors, and pKa, we focus especially on LogD and LogP as important physical properties that can be easily compared across a range of studies. We discuss the success of PET tracers in evaluating receptor occupancy and consider likely future developments in the field.
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Affiliation(s)
- Yuta Takamura
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Hiroki Kakuta
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
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26
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Yuan X, Zhang D, Mao S, Wang Q. Filling the Gap in Understanding the Mechanism of GABA AR and Propofol Using Computational Approaches. J Chem Inf Model 2021; 61:1889-1901. [PMID: 33823589 DOI: 10.1021/acs.jcim.0c01290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
γ-Aminobutyric acid type-A receptors (GABAARs) play a critical role in neural transmission by mediating the inhibitory neural firing and are the target of many psychiatric drugs. Among them, propofol is one of the most widely used and important general anesthetics in clinics. Recent advances in structural biology revealed the structure of a human GABAAR in both open and closed states. Yet, the detailed mechanism of the receptor and propofol remains to be fully understood. Therefore, in this study, based on the previous successes in structural biology, a variety of computational techniques were applied to fill the gap between previous experimental studies. This study investigated the ion-conducting mechanism of GABAAR, predicted the possible binding mechanism of propofol, and revealed a new motion mechanism of transmembrane domain (TMD) helices. We hope that this study may contribute to future studies on ion-channel receptors, general anesthetics, and drug development.
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Affiliation(s)
- Xinghang Yuan
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Di Zhang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Shengjun Mao
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Qiantao Wang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
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27
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Amundarain MJ, Caffarena ER, Costabel MD. How does α 1Histidine102 affect the binding of modulators to α 1β 2γ 2 GABA A receptors? molecular insights from in silico experiments. Phys Chem Chem Phys 2021; 23:3993-4006. [PMID: 33554986 DOI: 10.1039/d0cp05081d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The activation of GABAA receptors by the neurotransmitter gamma-aminobutyric acid mediates the rapid inhibition response in the central nervous system of mammals. Many neurological and mental health disorders arise from alterations in the structure or function of these pentameric ion channels. GABAA receptors are targets for numerous drugs, including benzodiazepines, which bind to α1β2γ2 GABAA receptors with high affinity to a site in the extracellular domain, between subunits α1 and γ2. It has been established experimentally that the binding of these drugs depends on the presence of one particular amino acid in the α1 subunit: histidine 102. However, the specific role it plays in the intermolecular interaction has not been elucidated. In this work, we applied in silico methods to understand whether certain protonation and rotamer states of α1His102 facilitate the binding of modulators. We analysed diazepam binding, a benzodiazepine, and the antagonist flumazenil to the GABAA receptor using molecular dynamics simulations and adaptive biasing force simulations. The binding free energy follows changes in the protonation state for both ligands, and rotameric states of α1His102 were specific for the different compounds, suggesting distinct preferences for positive allosteric modulators and antagonists. Moreover, in the presence of diazepam and favoured by a neutral tautomer, we identified a water molecule that links loops A, B, and C and may be relevant to the modulation mechanism.
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Affiliation(s)
- María Julia Amundarain
- Instituto de Física del Sur (IFISUR), Departamento de Física, Universidad Nacional del Sur (UNS), CONICET, Av. L. N. Alem 1253, B8000CPB - Bahía Blanca, Argentina.
| | - Ernesto Raúl Caffarena
- Programa de Computação Científica - PROCC, Fundação Oswaldo Cruz, Manguinhos, CEP 21040-360, Av. Brasil 4365, Rio de Janeiro, RJ, Brazil
| | - Marcelo Daniel Costabel
- Instituto de Física del Sur (IFISUR), Departamento de Física, Universidad Nacional del Sur (UNS), CONICET, Av. L. N. Alem 1253, B8000CPB - Bahía Blanca, Argentina.
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28
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Abstract
The adult brain is the result of a multistages complex neurodevelopmental process involving genetic, molecular and microenvironmental factors as well as diverse patterns of electrical activity. In the postnatal life, immature neuronal circuits undergo an experience-dependent maturation during critical periods of plasticity, but the brain still retains plasticity during adult life. In all these stages, the neurotransmitter GABA plays a pivotal role. In this chapter, we will describe the interaction of 5-HT with GABA in regulating neurodevelopment and plasticity.
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29
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Gao Y, Zhang Y, Wu F, Pei J, Luo X, Ju X, Zhao C, Liu G. Exploring the Interaction Mechanism of Desmethyl-broflanilide in Insect GABA Receptors and Screening Potential Antagonists by In Silico Simulations. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:14768-14780. [PMID: 33274636 DOI: 10.1021/acs.jafc.0c05728] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Broflanilide, a novel insecticide, is classified as a negative allosteric modulator (NAM) of insect γ-aminobutyric acid (GABA) receptors (GABARs) as desmethyl-broflanilide (DMBF) allosterically inhibits the GABA-induced responses. The G277M mutation of the Drosophila melanogaster GABAR subunit has been reported to abolish the inhibitory activity of DMBF. The binding mode of DMBF in insect GABARs needs to be clarified to understand the underlying mechanism of this mutation and to develop novel, efficient NAMs of insect GABARs. Here, we found that a hydrogen bond formed between DMBF and G277 of the D. melanogaster GABAR model might be the key interaction for the antagonism of DMBF by in silico simulations. The volume increase induced by the G277M mutation blocks the entrance of the binding pocket, making it difficult for DMBF to enter the binding pocket and thereby decreasing its activity. The following virtual screening and bioassay results identified a novel NAM candidate of insect GABARs. Overall, we reported a possible binding mode of DMBF in insect GABARs and proposed the insensitivity mechanism of the G277M mutant GABAR to DMBF using molecular simulations. The identified NAM candidates might provide more alternatives or potentials for the design of GABAR-targeting insecticides.
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Affiliation(s)
- Ya Gao
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, P. R. China
| | - Yichi Zhang
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Fengshou Wu
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, P. R. China
| | - Jianfeng Pei
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, P. R. China
| | - Xiaogang Luo
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, P. R. China
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, P. R. China
| | - Xiulian Ju
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, P. R. China
| | - Chunqing Zhao
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, P. R. China
| | - Genyan Liu
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, P. R. China
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30
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Cao JW, Guan W, Yu YC, Fu Y. Synaptic Transmission from Somatostatin-expressing Interneurons to Excitatory Neurons Mediated by α5-subunit-containing GABA A Receptors in the Developing Visual Cortex. Neuroscience 2020; 449:147-156. [PMID: 32926954 DOI: 10.1016/j.neuroscience.2020.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 08/29/2020] [Accepted: 09/02/2020] [Indexed: 11/16/2022]
Abstract
Dendrite-targeting somatostatin-expressing interneurons (SST-INs) powerfully control signal integration and synaptic plasticity in pyramidal dendrites during cortical development. We previously showed that synaptic transmission from SST-INs to pyramidal cells (PCs) (SST-IN → PC) in the mouse visual cortex suddenly declined at around the second postnatal week. However, it is unclear what specific postsynaptic mechanisms underlie this developmental change. Using multiple whole-cell patch-clamp recordings, we found that application of an α5-GABAA receptor-selective inverse agonist, alpha5IA, significantly weakened SST-IN → PC unitary inhibitory postsynaptic currents (uIPSCs) in layer 2/3 of the mouse visual cortex, but had no effect on uIPSCs from SST-INs to other types of interneurons. The extent of alpha5IA-induced reduction of SST-IN → PC synaptic transmission was significantly larger at postnatal days 11-13 (P11-13) than P14-17. Moreover, α5-subunit-containing GABAA receptors (α5-GABAARs)-mediated uIPSCs had slow rise and decay kinetics. Apart from pharmacological test, we observed that SST-IN → PC synapses did indeed contain α5-GABAARs by immunogold labeling for electron microscopy. More importantly, coinciding with the weakening of SST-IN → PC synaptic transmission, the number of α5-GABAAR particles in SST-IN → PC synapses significantly decreased at around the second postnatal week. Together, these data indicate that α5-GABAARs are involved in synaptic transmission from SST-INs to PCs in the neocortex, and are significantly diminished around the second postnatal week.
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Affiliation(s)
- Jun-Wei Cao
- Jing'an District Center Hospital of Shanghai, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Wuqiang Guan
- Jing'an District Center Hospital of Shanghai, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yong-Chun Yu
- Jing'an District Center Hospital of Shanghai, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yinghui Fu
- Jing'an District Center Hospital of Shanghai, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China.
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31
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Impaired Expression of GABA Signaling Components in the Alzheimer's Disease Middle Temporal Gyrus. Int J Mol Sci 2020; 21:ijms21228704. [PMID: 33218044 PMCID: PMC7698927 DOI: 10.3390/ijms21228704] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 12/26/2022] Open
Abstract
γ-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter, playing a central role in the regulation of cortical excitability and the maintenance of the excitatory/inhibitory (E/I) balance. Several lines of evidence point to a remodeling of the cerebral GABAergic system in Alzheimer’s disease (AD), with past studies demonstrating alterations in GABA receptor and transporter expression, GABA synthesizing enzyme activity and focal GABA concentrations in post-mortem tissue. AD is a chronic neurodegenerative disorder with a poorly understood etiology and the temporal cortex is one of the earliest regions in the brain to be affected by AD neurodegeneration. Utilizing NanoString nCounter analysis, we demonstrate here the transcriptional downregulation of several GABA signaling components in the post-mortem human middle temporal gyrus (MTG) in AD, including the GABAA receptor α1, α2, α3, α5, β1, β2, β3, δ, γ2, γ3, and θ subunits and the GABAB receptor 2 (GABABR2) subunit. In addition to this, we note the transcriptional upregulation of the betaine-GABA transporter (BGT1) and GABA transporter 2 (GAT2), and the downregulation of the 67 kDa isoform of glutamate decarboxylase (GAD67), the primary GABA synthesizing enzyme. The functional consequences of these changes require further investigation, but such alterations may underlie disruptions to the E/I balance that are believed to contribute to cognitive decline in AD.
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32
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Mir FR, Wilson C, Cabrera Zapata LE, Aguayo LG, Cambiasso MJ. Gonadal hormone-independent sex differences in GABA A receptor activation in rat embryonic hypothalamic neurons. Br J Pharmacol 2020; 177:3075-3090. [PMID: 32133616 DOI: 10.1111/bph.15037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 02/21/2020] [Accepted: 02/22/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND AND PURPOSE GABAA receptor functions are dependent on subunit composition, and, through their activation, GABA can exert trophic actions in immature neurons. Although several sex differences in GABA-mediated responses are known to be dependent on gonadal hormones, few studies have dealt with sex differences detected before the critical period of brain masculinisation. In this study, we assessed GABAA receptor functionality in sexually segregated neurons before brain hormonal masculinisation. EXPERIMENTAL APPROACH Ventromedial hypothalamic neurons were obtained from embryonic day 16 rat brains and grown in vitro for 2 days. Calcium imaging and electrophysiology recordings were carried out to assess GABAA receptor functional parameters. KEY RESULTS GABAA receptor activation elicited calcium entry in immature hypothalamic neurons mainly through L-type voltage-dependent calcium channels. Nifedipine blocked calcium entry more efficiently in male than in female neurons. There were more male than female neurons responding to GABA, and they needed more time to return to resting levels. Pharmacological characterisation revealed that propofol enhanced GABAA -mediated currents and blunted GABA-mediated calcium entry more efficiently in female neurons than in males. Testosterone treatment did not erase such sex differences. These data suggest sex differences in the expression of GABAA receptor subtypes. CONCLUSION AND IMPLICATIONS GABA-mediated responses are sexually dimorphic even in the absence of gonadal hormone influence, suggesting genetically biased differences. These results highlight the importance of GABAA receptors in hypothalamic neurons even before hormonal masculinisation of the brain.
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Affiliation(s)
- Franco R Mir
- Laboratorio de Neurofisiología, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina.,Cátedra de Fisiología Animal, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba, Argentina.,Cátedra de Fisiología Animal, Departamento de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de La Rioja, La Rioja, Argentina
| | - Carlos Wilson
- Laboratorio de Neurobiología, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina.,Centro de Investigación en Medicina Traslaciona, Instituto Universitario de Ciencias Biomédicas de Córdoba (IUCBC), Córdoba, Argentina
| | - Lucas E Cabrera Zapata
- Laboratorio de Neurofisiología, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Luis G Aguayo
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - María Julia Cambiasso
- Laboratorio de Neurofisiología, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina.,Departamento de Biología Bucal, Facultad de Odontología, Universidad Nacional de Córdoba, Córdoba, Argentina
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33
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Hantsoo L, Epperson CN. Allopregnanolone in premenstrual dysphoric disorder (PMDD): Evidence for dysregulated sensitivity to GABA-A receptor modulating neuroactive steroids across the menstrual cycle. Neurobiol Stress 2020; 12:100213. [PMID: 32435664 PMCID: PMC7231988 DOI: 10.1016/j.ynstr.2020.100213] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/24/2020] [Accepted: 01/31/2020] [Indexed: 01/01/2023] Open
Abstract
Premenstrual dysphoric disorder (PMDD) is a severe mood disorder with core symptoms (affective lability, irritability, depressed mood, anxiety) and increased sensitivity to stress occurring in the luteal phase of the menstrual cycle. PMDD can be conceptualized as a disorder of suboptimal sensitivity to neuroactive steroid hormones (NASs). In this review, we describe the role of the NAS allopregnanolone (ALLO), a positive allosteric modulator of the GABAA receptor (GABAA-R), in PMDD's pathophysiology. We review evidence of impaired interaction between ALLO and GABAA-Rs in terms of affective symptom expression, with evidence from rodent and human studies. We discuss evidence of increased luteal phase stress sensitivity as a result of poor ALLO-GABA control of the HPA axis. Finally, we describe how treatments such as selective serotonin reuptake inhibitors (SSRIs) and new drugs targeting GABAA-Rs provide evidence for impaired ALLO-GABA function in PMDD. In sum, the literature supports the hypothesis that PMDD pathophysiology is rooted in impaired GABAA-R response to dynamic ALLO fluctuations across the menstrual cycle, manifesting in affective symptoms and poor regulation of physiologic stress response.
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Affiliation(s)
- Liisa Hantsoo
- Department of Psychiatry & Behavioral Sciences, The Johns Hopkins University School of Medicine, 550 N, Broadway Street Baltimore, MD, 21205, USA
| | - C Neill Epperson
- Department of Psychiatry, University of Colorado School of Medicine Anschutz Medical Campus, 13001 E 17th Place, MS F546, Aurora, CO, 80045, USA
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Comprehensive Analysis of GABA A-A1R Developmental Alterations in Rett Syndrome: Setting the Focus for Therapeutic Targets in the Time Frame of the Disease. Int J Mol Sci 2020; 21:ijms21020518. [PMID: 31947619 PMCID: PMC7014188 DOI: 10.3390/ijms21020518] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/03/2020] [Accepted: 01/10/2020] [Indexed: 02/08/2023] Open
Abstract
Rett syndrome, a serious neurodevelopmental disorder, has been associated with an altered expression of different synaptic-related proteins and aberrant glutamatergic and γ-aminobutyric acid (GABA)ergic neurotransmission. Despite its severity, it lacks a therapeutic option. Through this work we aimed to define the relationship between MeCP2 and GABAA.-A1 receptor expression, emphasizing the time dependence of such relationship. For this, we analyzed the expression of the ionotropic receptor subunit in different MeCP2 gene-dosage and developmental conditions, in cells lines, and in primary cultured neurons, as well as in different developmental stages of a Rett mouse model. Further, RNAseq and systems biology analysis was performed from post-mortem brain biopsies of Rett patients. We observed that the modulation of the MeCP2 expression in cellular models (both Neuro2a (N2A) cells and primary neuronal cultures) revealed a MeCP2 positive effect on the GABAA.-A1 receptor subunit expression, which did not occur in other proteins such as KCC2 (Potassium-chloride channel, member 5). In the Mecp2+/− mouse brain, both the KCC2 and GABA subunits expression were developmentally regulated, with a decreased expression during the pre-symptomatic stage, while the expression was variable in the adult symptomatic mice. Finally, the expression of the gamma-aminobutyric acid (GABA) receptor-related synaptic proteins from the postmortem brain biopsies of two Rett patients was evaluated, specifically revealing the GABA A1R subunit overexpression. The identification of the molecular changes along with the Rett syndrome prodromic stages strongly endorses the importance of time frame when addressing this disease, supporting the need for a neurotransmission-targeted early therapeutic intervention.
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35
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Hamburger M. HPLC-based activity profiling for pharmacologically and toxicologically relevant natural products - principles and recent examples. PHARMACEUTICAL BIOLOGY 2019; 57:328-334. [PMID: 31057026 PMCID: PMC6507960 DOI: 10.1080/13880209.2019.1606261] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 04/02/2019] [Indexed: 05/30/2023]
Abstract
CONTEXT Discovery of pharmacologically active natural products as starting points for drug development remains important and, for reasons of consumer safety, the identification of toxicologically relevant compounds in herbal drugs. OBJECTIVE To explain, with the aid of relevant examples from our own research, how these goals can be achieved. METHODS An in-house technology platform comprising pre-formatted extract libraries in 96-well format, miniaturized tracking of activity in extracts via HPLC-activity profiling, structure elucidation with microprobe NMR, and in vitro and in vivo pharmacological methods were used. RESULTS Piperine was identified as a new scaffold for allosteric GABAA receptor modulators with in vivo activity that interacts at a benzodiazepine-independent binding site. Selectivity and potency were improved by iterative optimization towards synthetic piperine analogues. Dehydroevodiamine and hortiamine from the traditional Chinese herbal drug Evodiae fructus were identified as potent hERG channel blockers in vitro. The compounds induced torsades de pointes arrhythmia in animal models. CONCLUSIONS The allosteric binding site for piperine analogues remains to be characterized and cardiac risks of herbal drugs need to be further evaluated to ensure consumer safety.
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Affiliation(s)
- Matthias Hamburger
- Pharmaceutical Biology, Pharmacenter, University of Basel, Basel, Switzerland
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36
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Gender-dependent regulation of anxiety-like behavior by δ subunit-containing GABAA receptor during postnatal development. Neuroreport 2019; 30:753-759. [PMID: 31261237 DOI: 10.1097/wnr.0000000000001192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The δ subunit-containing GABAA receptor [GABAA(δ)R], which is exclusively situated in the extrasynaptic space, has considerable influence on emotion and behavior. Although the expression of this receptor experiences dramatic fluctuation during postnatal development, it remains unknown whether it regulates emotion in a development-dependent manner. Here, by using mice with genetic deletion of GABAA(δ)R (knockout) and their wild-type littermates, we examined the role of GABAA(δ)R in regulating anxiety-like behavior, as measured with open field test (OFT) and elevated plus maze during the transition from puberty to adulthood. We observed that for female mice, the knockout ones at puberty but not adulthood showed increased anxiety-like behavior in the OFT relative to their wild-type littermates. However, such increase was not observed in elevated plus maze. For male mice, no between-genotype differences were observed in both tests at the above two developmental stages. Our results suggest that GABAA(δ)R preferentially affects the anxiety-like behavior in OFT in a development-dependent manner, but only in female mice.
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37
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Moslem M, Olive J, Falk A. Stem cell models of schizophrenia, what have we learned and what is the potential? Schizophr Res 2019; 210:3-12. [PMID: 30587427 DOI: 10.1016/j.schres.2018.12.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 12/14/2018] [Accepted: 12/16/2018] [Indexed: 12/13/2022]
Abstract
Schizophrenia is a complex disorder with clinical manifestations in early adulthood. However, it may start with disruption of brain development caused by genetic or environmental factors, or both. Early deteriorating effects of genetic/environmental factors on neural development might be key to described disease causing mechanisms. Establishing cellular models with cells from affected individual using the induced pluripotent stem cells (iPSC) technology could be used to mimic early neurodevelopment alterations caused by risk genes or environmental stressors. Indeed, cellular models have allowed identification and further study of risk factors and the biological pathways in which they are involved. New advancements in differentiation methods such as defined and robust monolayer protocols and cerebral 3D organoids have made it possible to faithfully mimic neural development and neuronal functionality while CRISPR-editing tools assist to engineer isogenic cell lines to precisely explore genetic variation in polygenic diseases such as schizophrenia. Here we review the current field of iPSC models of schizophrenia and how risk factors can be modelled as well as discussing the common biological pathways involved.
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Affiliation(s)
- Mohsen Moslem
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Jessica Olive
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Life Sciences, Imperial College London, United Kingdom.
| | - Anna Falk
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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38
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García-Nafría J, Tate CG. Cryo-Electron Microscopy: Moving Beyond X-Ray Crystal Structures for Drug Receptors and Drug Development. Annu Rev Pharmacol Toxicol 2019; 60:51-71. [PMID: 31348870 DOI: 10.1146/annurev-pharmtox-010919-023545] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Electron cryo-microscopy (cryo-EM) has revolutionized structure determination of membrane proteins and holds great potential for structure-based drug discovery. Here we discuss the potential of cryo-EM in the rational design of therapeutics for membrane proteins compared to X-ray crystallography. We also detail recent progress in the field of drug receptors, focusing on cryo-EM of two protein families with established therapeutic value, the γ-aminobutyric acid A receptors (GABAARs) and G protein-coupled receptors (GPCRs). GABAARs are pentameric ion channels, and cryo-EM structures of physiological heteromeric receptors in a lipid environment have uncovered the molecular basis of receptor modulation by drugs such as diazepam. The structures of ten GPCR-G protein complexes from three different classes of GPCRs have now been determined by cryo-EM. These structures give detailed insights into molecular interactions with drugs, GPCR-G protein selectivity, how accessory membrane proteins alter receptor-ligand pharmacology, and the mechanism by which HIV uses GPCRs to enter host cells.
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Affiliation(s)
- Javier García-Nafría
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom; .,Current affiliation: Institute for Biocomputation and Physics of Complex Systems (BIFI) and Laboratorio de Microscopias Avanzadas, University of Zaragoza, 50018 Zaragoza, Spain;
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Mattei C, Taly A, Soualah Z, Saulais O, Henrion D, Guérineau NC, Verleye M, Legros C. Involvement of the GABA A receptor α subunit in the mode of action of etifoxine. Pharmacol Res 2019; 145:104250. [PMID: 31059790 DOI: 10.1016/j.phrs.2019.04.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 03/21/2019] [Accepted: 04/27/2019] [Indexed: 12/31/2022]
Abstract
Etifoxine (EFX) is a non-benzodiazepine psychoactive drug which exhibits anxiolytic effects through a dual mechanism, by directly binding to GABAA receptors (GABAARs) and to the mitochondrial 18-kDa translocator protein, resulting in the potentiation of the GABAergic function. The β subunit subtype plays a key role in the EFX-GABAAR interaction, however this does not explain the anxiolytic effects of this drug. Here, we combined behavioral and electrophysiological experiments to challenge the role of the GABAAR α subunit in the EFX mode of action. After single administrations of anxiolytic doses (25-50 mg/kg, intraperitoneal), EFX did not induce any neurological nor locomotor impairments, unlike the benzodiazepine bromazepam (0.5-1 mg/kg, intraperitoneal). We established the EFX pharmacological profile on heteropentameric GABAARs constructed with α1 to α6 subunit expressed in Xenopus oocyte. Unlike what is known for benzodiazepines, neither the γ nor δ subunits influenced EFX-mediated potentiation of GABA-evoked currents. EFX acted first as a partial agonist on α2β3γ2S, α3β3γ2S, α6β3γ2S and α6β3δ GABAARs, but not on α1β3γ2S, α4β3γ2S, α4β3δ nor α5β3γ2S GABAARs. Moreover, EFX exhibited much higher positive allosteric modulation towards α2β3γ2S, α3β3γ2S and α6β3γ2S than for α1β3γ2S, α4β3γ2S and α5β3γ2S GABAARs. At 20 μM, corresponding to brain concentration at anxiolytic doses, EFX increased GABA potency to the highest extent for α3β3γ2S GABAARs. We built a docking model of EFX on α3β3γ2S GABAARs, which is consistent with a binding site located between α and β subunits in the extracellular domain. In conclusion, EFX preferentially potentiates α2β3γ2S and α3β3γ2S GABAARs, which might support its advantageous anxiolytic/sedative balance.
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Affiliation(s)
- César Mattei
- Institut MITOVASC, UMR CNRS 6015 - UMR INSERM U1083, Université d'Angers, 3 Rue Roger Amsler 49100 ANGERS, France.
| | - Antoine Taly
- Theoretical Biochemistry Laboratory, Institute of Physico-Chemical Biology, CNRS UPR9080, University of Paris Diderot Sorbonne Paris Cité, 75005 Paris, France
| | - Zineb Soualah
- Institut MITOVASC, UMR CNRS 6015 - UMR INSERM U1083, Université d'Angers, 3 Rue Roger Amsler 49100 ANGERS, France
| | - Ophélie Saulais
- Institut MITOVASC, UMR CNRS 6015 - UMR INSERM U1083, Université d'Angers, 3 Rue Roger Amsler 49100 ANGERS, France
| | - Daniel Henrion
- Institut MITOVASC, UMR CNRS 6015 - UMR INSERM U1083, Université d'Angers, 3 Rue Roger Amsler 49100 ANGERS, France
| | - Nathalie C Guérineau
- Institut MITOVASC, UMR CNRS 6015 - UMR INSERM U1083, Université d'Angers, 3 Rue Roger Amsler 49100 ANGERS, France
| | - Marc Verleye
- Biocodex, Department of Pharmacology, Zac de Mercières, 60200 Compiègne, France
| | - Christian Legros
- Institut MITOVASC, UMR CNRS 6015 - UMR INSERM U1083, Université d'Angers, 3 Rue Roger Amsler 49100 ANGERS, France.
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40
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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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41
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Hernandez CC, Macdonald RL. A structural look at GABA A receptor mutations linked to epilepsy syndromes. Brain Res 2019; 1714:234-247. [PMID: 30851244 DOI: 10.1016/j.brainres.2019.03.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 02/25/2019] [Accepted: 03/06/2019] [Indexed: 12/12/2022]
Abstract
Understanding the genetic variation in GABAA receptor subunit genes (GABRs), GABRA1-6, GABRB1-3, GABRG1-3 and GABRD, in individuals affected by epilepsy may improve the diagnosis and treatment of epilepsy syndromes through identification of disease-associated variants. However, the lack of functional analysis and validation of many novel and previously reported familial and de novo mutations have made it challenging to address meaningful gene associations with epilepsy syndromes. GABAA receptors belong to the Cys-loop receptor family. Even though GABAA receptor mutant residues are widespread among different GABRs, their frequent occurrence in important structural domains that share common functional features suggests associations between structure and function.
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Affiliation(s)
- Ciria C Hernandez
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.
| | - Robert L Macdonald
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
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42
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Syafni N, Moradi-Afrapoli F, Danton O, Wilhelm A, Stadler M, Hering S, Potterat O, Hamburger M. HPLC-Based Activity Profiling for GABA A Receptor Modulators in Murraya exotica. Nat Prod Commun 2019. [DOI: 10.1177/1934578x1901400112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A dichloromethane extract from twigs and leaves of Murraya exotica produced allosteric potentiation of gamma aminobutyric acid (GABA) induced chloride currents in a microelectrode assay in Xenopus laevis oocytes expressing GABA receptors of α1, β2, γ2s subunit composition. The activity was tracked by HPLC-based activity profiling utilizing a zebrafish locomotor activity assay. Osthol (9) was identified as the main active compound. In addition, five other coumarins and four flavonols were identified. Osthol (9) and structurally related coumurrayin (10) were tested in the Xenopus oocyte assay. Compound 9 potentiated GABAA-induced chloride currents by 487 ± 42%, with an EC50 of 46 ± 10 μM, while 10 showed negligible effects on chloride currents. In silico evaluation of physicochemical properties showed that 9 and 10 had properties that are favorable for oral bioavailability and BBB permeability.
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Affiliation(s)
- Nova Syafni
- Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
- Faculty of Pharmacy/Sumatran Biota Laboratory, Andalas University, 25163 Padang, West Sumatra, Indonesia
| | | | - Ombeline Danton
- Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Anke Wilhelm
- Faculty of Natural and Agricultural Sciences, University of the Free State, 9300 Bloemfontein, Republic of South Africa
| | - Marco Stadler
- Department of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Steffen Hering
- Department of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Olivier Potterat
- Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Matthias Hamburger
- Pharmaceutical Biology, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
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43
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Stadler M, Monticelli S, Seidel T, Luger D, Salzer I, Boehm S, Holzer W, Schwarzer C, Urban E, Khom S, Langer T, Pace V, Hering S. Design, Synthesis, and Pharmacological Evaluation of Novel β2/3 Subunit-Selective γ-Aminobutyric Acid Type A (GABA A) Receptor Modulators. J Med Chem 2018; 62:317-341. [PMID: 30289721 DOI: 10.1021/acs.jmedchem.8b00859] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Subunit-selective modulation of γ-aminobutyric acid type A receptors (GABAAR) is considered to exert fewer side effects compared to unselective clinically used drugs. Here, the β2/3 subunit-selective GABAAR modulators valerenic acid (VA) and loreclezole (LOR) guided the synthesis of novel subunit-selective ligands with simplified structures. We studied their effects on GABAARs expressed in Xenopus laevis oocytes using two-microelectrode voltage clamp technique. Five compounds showed significantly more efficacious modulation of GABA-evoked currents than VA and LOR with retained potency and selectivity. Compound 18 [( E)-2-Cyano-3-(2,4-dichlorophenyl)but-2-enamide] induced the highest maximal modulation of GABA-induced chloride currents ( Emax: 3114 ± 242%), while 12 [( Z)-3-(2,4-dichlorophenyl)but-2-enenitrile] displayed the highest potency (EC50: 13 ± 2 μM). Furthermore, in hippocampal neurons 12 facilitated phasic and tonic GABAergic inhibition, and in vivo studies revealed significantly more potent protection against pentylenetetrazole (PTZ)-induced seizures compared to VA and LOR. Collectively, compound 12 constitutes a novel, simplified, and subunit-selective GABAAR modulator with low-dose anticonvulsant activity.
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Affiliation(s)
- Marco Stadler
- Department of Pharmacology and Toxicology , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Serena Monticelli
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Thomas Seidel
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Denise Luger
- Department of Pharmacology and Toxicology , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Isabella Salzer
- Department of Neurophysiology and Neuropharmacology , Medical University Vienna , Schwarzspanierstraße 17 , 1090 Vienna , Austria
| | - Stefan Boehm
- Department of Neurophysiology and Neuropharmacology , Medical University Vienna , Schwarzspanierstraße 17 , 1090 Vienna , Austria
| | - Wolfgang Holzer
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Christoph Schwarzer
- Department of Pharmacology , Medical University Innsbruck , Peter-Mayr-Straße 1a , 6020 Innsbruck , Austria
| | - Ernst Urban
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Sophia Khom
- Department of Pharmacology and Toxicology , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria.,Department of Neuroscience , The Scripps Research Institute , 10550 N Torrey Pines Road , La Jolla , California 92037 , United States
| | - Thierry Langer
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Vittorio Pace
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Steffen Hering
- Department of Pharmacology and Toxicology , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
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44
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Kim JK, Kim YS, Lee HM, Jin HS, Neupane C, Kim S, Lee SH, Min JJ, Sasai M, Jeong JH, Choe SK, Kim JM, Yamamoto M, Choy HE, Park JB, Jo EK. GABAergic signaling linked to autophagy enhances host protection against intracellular bacterial infections. Nat Commun 2018; 9:4184. [PMID: 30305619 PMCID: PMC6180030 DOI: 10.1038/s41467-018-06487-5] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 09/06/2018] [Indexed: 12/25/2022] Open
Abstract
Gamma-aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the brain; however, the roles of GABA in antimicrobial host defenses are largely unknown. Here we demonstrate that GABAergic activation enhances antimicrobial responses against intracellular bacterial infection. Intracellular bacterial infection decreases GABA levels in vitro in macrophages and in vivo in sera. Treatment of macrophages with GABA or GABAergic drugs promotes autophagy activation, enhances phagosomal maturation and antimicrobial responses against mycobacterial infection. In macrophages, the GABAergic defense is mediated via macrophage type A GABA receptor (GABAAR), intracellular calcium release, and the GABA type A receptor-associated protein-like 1 (GABARAPL1; an Atg8 homolog). Finally, GABAergic inhibition increases bacterial loads in mice and zebrafish in vivo, suggesting that the GABAergic defense plays an essential function in metazoan host defenses. Our study identified a previously unappreciated role for GABAergic signaling in linking antibacterial autophagy to enhance host innate defense against intracellular bacterial infection. Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in neuronal systems, but the potential role for such neurotransmitters on the immune system are emerging. Here the authors show GABA signaling is linked to autophagy, enhancing the host response against intracellular bacteria.
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Affiliation(s)
- Jin Kyung Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, 35015, Korea.,Department of Medical Science, Chungnam National University School of Medicine, Daejeon, 35015, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, 35015, Korea
| | - Yi Sak Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, 35015, Korea.,Department of Medical Science, Chungnam National University School of Medicine, Daejeon, 35015, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, 35015, Korea
| | - Hye-Mi Lee
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, 35015, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, 35015, Korea
| | - Hyo Sun Jin
- Biomedical Research Institute, Chungnam National University Hospital, Daejeon, 35015, Korea
| | - Chiranjivi Neupane
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon, 35015, Korea.,Department of Physiology, Chungnam National University School of Medicine, Daejeon, 35015, Korea
| | - Sup Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, 35015, Korea.,Department of Medical Science, Chungnam National University School of Medicine, Daejeon, 35015, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, 35015, Korea
| | - Sang-Hee Lee
- Institute of Molecular Biology & Genetics, Seoul National University, Seoul, 08826, Korea
| | - Jung-Joon Min
- Department of Nuclear Medicine, Chonnam National University Medical School, Gwangju, 61469, Korea
| | - Miwa Sasai
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, 565-0871, Japan
| | - Jae-Ho Jeong
- Department of Microbiology, Chonnam National University Medical School, Gwangju, 61469, Korea.,Molecular Medicine, BK21 Plus, Chonnam National University Graduate School, Gwangju, 61186, Korea
| | - Seong-Kyu Choe
- Department of Microbiology and Center for Metabolic Function Regulation, Wonkwang University School of Medicine, Iksan, Jeonbuk, 54538, Korea
| | - Jin-Man Kim
- Department of Pathology, Chungnam National University School of Medicine, Daejeon, 35015, Korea
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Osaka, 565-0871, Japan
| | - Hyon E Choy
- Department of Microbiology, Chonnam National University Medical School, Gwangju, 61469, Korea.,Molecular Medicine, BK21 Plus, Chonnam National University Graduate School, Gwangju, 61186, Korea
| | - Jin Bong Park
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon, 35015, Korea. .,Department of Physiology, Chungnam National University School of Medicine, Daejeon, 35015, Korea.
| | - Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, 35015, Korea.,Department of Medical Science, Chungnam National University School of Medicine, Daejeon, 35015, Korea.,Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon, 35015, Korea
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45
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Low SE, Ito D, Hirata H. Characterization of the Zebrafish Glycine Receptor Family Reveals Insights Into Glycine Receptor Structure Function and Stoichiometry. Front Mol Neurosci 2018; 11:286. [PMID: 30323738 PMCID: PMC6130310 DOI: 10.3389/fnmol.2018.00286] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 07/30/2018] [Indexed: 11/28/2022] Open
Abstract
To study characterization of zebrafish glycine receptors (zGlyRs), we assessed expression and function of five α- and two ß-subunit encoding GlyR in zebrafish. Our qPCR analysis revealed variable expression during development, while in situ hybridizations uncovered expression in the hindbrain and spinal cord; a finding consistent with the reported expression of GlyR subunits in these tissues from other organisms. Electrophysiological recordings using Xenopus oocytes revealed that all five α subunits form homomeric receptors activated by glycine, and inhibited by strychnine and picrotoxin. In contrast, ß subunits only formed functional heteromeric receptors when co-expressed with α subunits. Curiously, the second transmembranes of both ß subunits were found to lack a phenylalanine at the sixth position that is commonly associated with conferring picrotoxin resistance to heteromeric receptors. Consistent with the absence of phenylalanines at the sixth position, heteromeric zGlyRs often lacked significant picrotoxin resistance. Subsequent efforts revealed that resistance to picrotoxin in both zebrafish and human heteromeric GlyRs involves known residues within transmembrane 2, as well as previously unknown residues within transmembrane 3. We also found that a dominant mutation in human GlyRα1 that gives rise to hyperekplexia, and recessive mutations in zebrafish GlyRßb that underlie the bandoneon family of motor mutants, result in reduced receptor function. Lastly, through the use of a concatenated construct we demonstrate that zebrafish heteromeric receptors assemble with a stoichiometry of 3α:2ß. Collectively, our findings have furthered our knowledge regarding the assembly of heteromeric receptors, and the molecular basis of ß subunit-conferred picrotoxin resistance. These results should aid in future investigations of glycinergic signaling in zebrafish and mammals.
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Affiliation(s)
- Sean Eric Low
- Department of Chemistry and Biological Science, Aoyama Gakuin University, Sagamihara, Japan
| | - Daishi Ito
- Department of Chemistry and Biological Science, Aoyama Gakuin University, Sagamihara, Japan
| | - Hiromi Hirata
- Department of Chemistry and Biological Science, Aoyama Gakuin University, Sagamihara, Japan
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Calvo-Flores Guzmán B, Vinnakota C, Govindpani K, Waldvogel HJ, Faull RL, Kwakowsky A. The GABAergic system as a therapeutic target for Alzheimer's disease. J Neurochem 2018; 146:649-669. [DOI: 10.1111/jnc.14345] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 02/21/2018] [Accepted: 03/14/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Beatriz Calvo-Flores Guzmán
- Centre for Brain Research; Faculty of Medical and Health Sciences; Department of Anatomy and Medical Imaging; University of Auckland; Auckland New Zealand
| | - Chitra Vinnakota
- Centre for Brain Research; Faculty of Medical and Health Sciences; Department of Anatomy and Medical Imaging; University of Auckland; Auckland New Zealand
| | - Karan Govindpani
- Centre for Brain Research; Faculty of Medical and Health Sciences; Department of Anatomy and Medical Imaging; University of Auckland; Auckland New Zealand
| | - Henry J. Waldvogel
- Centre for Brain Research; Faculty of Medical and Health Sciences; Department of Anatomy and Medical Imaging; University of Auckland; Auckland New Zealand
| | - Richard L.M. Faull
- Centre for Brain Research; Faculty of Medical and Health Sciences; Department of Anatomy and Medical Imaging; University of Auckland; Auckland New Zealand
| | - Andrea Kwakowsky
- Centre for Brain Research; Faculty of Medical and Health Sciences; Department of Anatomy and Medical Imaging; University of Auckland; Auckland New Zealand
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Toxins as tools: Fingerprinting neuronal pharmacology. Neurosci Lett 2018; 679:4-14. [DOI: 10.1016/j.neulet.2018.02.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/09/2018] [Accepted: 02/02/2018] [Indexed: 12/30/2022]
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Xiang B, Liu K, Yu M, Liang X, Zhang J, Lei W, Huang C, Chen J, Gu X, Li N, Wu G, Wang Y, He W, Tan J, Zhang T. Systematic genetic analyses of genome-wide association study data reveal an association between the key nucleosome remodeling and deacetylase complex and bipolar disorder development. Bipolar Disord 2018; 20:370-380. [PMID: 29280245 DOI: 10.1111/bdi.12580] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 10/21/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND Genome-wide association studies (GWASs) are used to identify genetic variants for association with bipolar disorder (BD) risk; however, each GWAS can only reveal a small fraction of this association. This study systematically analyzed multiple GWAS data sets to provide further insights into potential causal BD processes by integrating the results of Psychiatric Genomics Consortium Phase I (PGC-I) for BD with core human pathways and functional networks. METHODS The i-Gsea4GwasV2 program was used to analyze data from the PGC-I GWAS for BD (the pathways came from Reactome), as well as the nominally significant pathways. We established a gene network of the significant pathways and performed a gene set analysis for each gene cluster of the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) GWAS data for the volumes of the intracranial region and seven subcortical regions. RESULTS A total of 30 of 1816 Reactome pathways were identified and showed associations with BD risk. We further revealed 22 interconnected functional and topologically interacting clusters (Clusters 0-21) that were associated with BD risk. Moreover, we obtained brain transcriptome data from BrainSpan and found significant associations between common variants of the genes in Cluster 1 with the hippocampus (HIP; P = .026; family-wise error [FWE] correction) and amygdala (AMY; P = .016; FEW correction) in Cluster 8 with HIP (P = .022; FWE correction). The genes in Cluster 1 were enriched for the transcriptional co-expression profile in the prenatal AMY, and core genes (CDH4, MTA2, RBBP4, and HDAC2) were identified to be involved in regulating early brain development. CONCLUSION This study demonstrated that the HIP and AMY play a central role in neurodevelopment and BD risk.
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Affiliation(s)
- Bo Xiang
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Kezhi Liu
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Minglan Yu
- Medical Laboratory Center, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Xuemei Liang
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Jin Zhang
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Wei Lei
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Chaohua Huang
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Jing Chen
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Xiaochu Gu
- Clinical Laboratory, Su zhou Guang ji Hospital, Suzhou, Jiangsu Province, China
| | - Nian Li
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Guoying Wu
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Yan Wang
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Wenying He
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Jinhua Tan
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
| | - Tao Zhang
- Department of Psychiatry, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
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Amundarain MJ, Viso JF, Zamarreño F, Giorgetti A, Costabel M. Orthosteric and benzodiazepine cavities of the α 1β 2γ 2 GABA A receptor: insights from experimentally validated in silico methods. J Biomol Struct Dyn 2018; 37:1597-1615. [PMID: 29633901 DOI: 10.1080/07391102.2018.1462733] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
γ-aminobutyric acid-type A (GABAA) receptors mediate fast synaptic inhibition in the central nervous system of mammals. They are modulated via several sites by numerous compounds, which include GABA, benzodiazepines, ethanol, neurosteroids and anaesthetics among others. Due to their potential as targets of novel drugs, a detailed knowledge of their structure-function relationships is needed. Here, we present the model of the α1β2γ2 subtype GABAA receptor in the APO state and in complex with selected ligands, including agonists, antagonists and allosteric modulators. The model is based on the crystallographic structure of the human β3 homopentamer GABAA receptor. The complexes were refined using atomistic molecular dynamics simulations. This allowed a broad description of the binding modes and the detection of important interactions in agreement with experimental information. From the best of our knowledge, this is the only model of the α1β2γ2 GABAA receptor that represents altogether the desensitized state of the channel and comprehensively describes the interactions of ligands of the orthosteric and benzodiazepines binding sites in agreement with the available experimental data. Furthermore, it is able to explain small differences regarding the binding of a variety of chemically divergent ligands. Finally, this new model may pave the way for the design of focused experimental studies that will allow a deeper description of the receptor.
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Affiliation(s)
- María Julia Amundarain
- a Departamento de Física, Instituto de Física del Sur (IFISUR) , Universidad Nacional del Sur (UNS), CONICET , Bahía Blanca , Argentina
| | - Juan Francisco Viso
- a Departamento de Física, Instituto de Física del Sur (IFISUR) , Universidad Nacional del Sur (UNS), CONICET , Bahía Blanca , Argentina
| | - Fernando Zamarreño
- a Departamento de Física, Instituto de Física del Sur (IFISUR) , Universidad Nacional del Sur (UNS), CONICET , Bahía Blanca , Argentina
| | - Alejandro Giorgetti
- b Faculty of Mathematical, Physical and Natural Sciences, Department of Biotechnology , University of Verona , Verona , Italy.,c Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Computational Biomedicine, Institute of Neuroscience and Medicine INM-9 , Forschungszentrum Jülich , Jülich , Germany
| | - Marcelo Costabel
- a Departamento de Física, Instituto de Física del Sur (IFISUR) , Universidad Nacional del Sur (UNS), CONICET , Bahía Blanca , Argentina
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Monesson-Olson B, McClain JJ, Case AE, Dorman HE, Turkewitz DR, Steiner AB, Downes GB. Expression of the eight GABAA receptor α subunits in the developing zebrafish central nervous system. PLoS One 2018; 13:e0196083. [PMID: 29702678 PMCID: PMC5922542 DOI: 10.1371/journal.pone.0196083] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/05/2018] [Indexed: 11/26/2022] Open
Abstract
GABA is a robust regulator of both developing and mature neural networks. It exerts many of its effects through GABAA receptors, which are heteropentamers assembled from a large array of subunits encoded by distinct genes. In mammals, there are 19 different GABAA subunit types, which are divided into the α, β, γ, δ, ε, π, θ and ρ subfamilies. The immense diversity of GABAA receptors is not fully understood. However, it is known that specific isoforms, with their distinct biophysical properties and expression profiles, tune responses to GABA. Although larval zebrafish are well-established as a model system for neural circuit analysis, little is known about GABAA receptors diversity and expression in this system. Here, using database analysis, we show that the zebrafish genome contains at least 23 subunits. All but the mammalian θ and ε subunits have at least one zebrafish ortholog, while five mammalian GABAA receptor subunits have two zebrafish orthologs. Zebrafish contain one subunit, β4, which does not have a clear mammalian ortholog. Similar to mammalian GABAA receptors, the zebrafish α subfamily is the largest and most diverse of the subfamilies. In zebrafish there are eight α subunits, and RNA in situ hybridization across early zebrafish development revealed that they demonstrate distinct patterns of expression in the brain, spinal cord, and retina. Some subunits were very broadly distributed, whereas others were restricted to small populations of cells. Subunit-specific expression patterns in zebrafish resembled were those found in frogs and rodents, which suggests that the roles of different GABAA receptor isoforms are largely conserved among vertebrates. This study provides a platform to examine isoform specific roles of GABAA receptors within zebrafish neural circuits and it highlights the potential of this system to better understand the remarkable heterogeneity of GABAA receptors.
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Affiliation(s)
- Bryan Monesson-Olson
- Neuroscience and Behavior Graduate Program, University of Massachusetts, Amherst, MA, United States of America
- Biology Department, University of Massachusetts, Amherst, MA, United States of America
| | - Jon J. McClain
- Biology Department, University of Massachusetts, Amherst, MA, United States of America
| | - Abigail E. Case
- Biology Department, University of Massachusetts, Amherst, MA, United States of America
| | - Hanna E. Dorman
- Biology Department, University of Massachusetts, Amherst, MA, United States of America
| | - Daniel R. Turkewitz
- Department of Biology and Health Sciences, Pace University, Pleasantville, NY, United States of America
| | - Aaron B. Steiner
- Department of Biology and Health Sciences, Pace University, Pleasantville, NY, United States of America
| | - Gerald B. Downes
- Neuroscience and Behavior Graduate Program, University of Massachusetts, Amherst, MA, United States of America
- Biology Department, University of Massachusetts, Amherst, MA, United States of America
- * E-mail:
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