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Marecki R, Kałuska J, Kolanek A, Hakało D, Waszkiewicz N. Zuranolone - synthetic neurosteroid in treatment of mental disorders: narrative review. Front Psychiatry 2023; 14:1298359. [PMID: 38116383 PMCID: PMC10729607 DOI: 10.3389/fpsyt.2023.1298359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 11/13/2023] [Indexed: 12/21/2023] Open
Abstract
With each passing year, the number of people suffering from mental disorders grows at a disturbing speed. Neuroactive steroids are a new promising group of drugs with the potential for use in many diseases like postpartum depression, postnatal psychosis, major depression, insomnia, bipolar disorder, and Parkinson's tremor, due to their ability to modulate the activity of GABAA receptor. Neurosteroids are progesterone metabolites that are synthesized from cholesterol or steroid hormones in various brain regions. They regulate neuronal development, regeneration, and neurotransmission. They are implicated in mood disorders, anxiety disorders, schizophrenia, PTSD, and impulsive aggression. Neurosteroids have been studied for their potential to prevent or treat neurodegenerative diseases such as Alzheimer's disease and HIV-associated dementia. They can promote neurogenesis, neuronal survival, myelination, and memory function. They can also affect the growth and sensitivity of hormone-dependent brain tumors such as gliomas. Zuranolone, a newly registered neurosteroid drug has shown huge flexibility in both clinical and ambulatory treatment thanks to its pharmacokinetic traits, especially the possibility for oral administration, unlike its predecessor Brexanolone. Zuranolone is a synthetic positive allosteric modulator of the GABAA receptor that can be taken orally. The review aims to summarize the current knowledge on zuranolone as a novel neurosteroid drug for various mental disorders, especially for postpartum mental disorders for which this drug was meant originally. It covers studies indexed in the PubMed, Scopus, and Web of Science databases published since 2017. Keywords used in the search, as well as inclusion and exclusion criteria, are given in the aims and methodology section. The review explains the evidence for the role of neurosteroids, especially allopregnanolone, in the pathophysiology and treatment of postpartum depression. It discusses the mechanisms of neurosteroid action, the changes in neurosteroid levels during pregnancy and postpartum, and the clinical trials of brexanolone and zuranolone, two synthetic analogs of allopregnanolone, for postpartum depression. It provides an overview of the biosynthesis and metabolism of neurosteroids in the central and peripheral nervous system. Furthermore, it explains the different sources and pathways of neurosteroid production and the factors that influence their synthesis and regulation, such as stress, hormones, drugs, and genetic variations. The review also explores the potential relevance of neurosteroids for other psychiatric disorders, such as major depression, bipolar disorder, post-traumatic stress disorder (PTSD), schizophrenia, and premenstrual dysphoric disorder. Finally, it highlights the associations between neurosteroid levels and symptom severity and the effects of neurosteroid modulation on mood, cognition, and neuroplasticity.
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Alvarez LD, Alves NRC. Molecular determinants of tetrahydrocannabinol binding to the glycine receptor. Proteins 2023; 91:400-411. [PMID: 36271319 DOI: 10.1002/prot.26438] [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: 08/02/2022] [Revised: 10/04/2022] [Accepted: 10/18/2022] [Indexed: 02/03/2023]
Abstract
The recognition of Cannabis as a source of new compounds suitable for medical use has attracted strong interest from the scientific community in its research, and substantial progress has accumulated regarding cannabinoids' activity; however, a thorough description of their molecular mechanisms of action remains a task to complete. Highlighting their complex pharmacology, the list of cannabinoids' interactors has vastly expanded beyond the canonical cannabinoid receptors. Among those, we have focused our study on the glycine receptor (GlyR), an ion channel involved in the modulation of nervous system responses, including, to our interest, sensitivity to peripheral pain. Here, we report the use of computational methods to investigate possible binding modes between the GlyR and Δ9 -tetrahydrocannabinol (THC). After obtaining a first pose for the THC binding from a biased molecular docking simulation and subsequently evaluating it by molecular dynamic simulations, we found a dynamic system with an identifiable representative binding mode characterized by the specific interaction with two transmembrane residues (Phe293 and Ser296). Complementarily, we assessed the role of membrane cholesterol in this interaction and positively established its relevance for THC binding to GlyR. Lastly, the use of restrained molecular dynamics simulations allowed us to refine the description of the binding mode and of the cholesterol effect. Altogether, our findings contribute to the current knowledge about the GlyR-THC mode of binding and propose a new starting point for future research on how cannabinoids in general, and THC in particular, modulate pain perception in view of its possible clinical applications.
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Affiliation(s)
- Lautaro D Alvarez
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Universidad de Buenos Aires, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, UMYMFOR, Buenos Aires, Argentina
| | - N R Carina Alves
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Universidad de Buenos Aires, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, IFIBYNE, Buenos Aires, Argentina
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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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Velisek L. From Standard of Care to Personalized (Art of) Medicine: Two Novel GABA-A Receptor β3 Subunit Mutations Associated With Epilepsy Syndromes. Epilepsy Curr 2019; 20:45-47. [PMID: 31852240 PMCID: PMC7020529 DOI: 10.1177/1535759719889624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
[Box: see text].
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Alvarez LD, Pecci A. Mapping the neurosteroid binding sites on glycine receptors. J Steroid Biochem Mol Biol 2019; 192:105388. [PMID: 31176751 DOI: 10.1016/j.jsbmb.2019.105388] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/27/2019] [Accepted: 05/30/2019] [Indexed: 11/18/2022]
Abstract
Glycine is a major inhibitory neurotransmitter in the CNS, where it modulates both sensory and motor transduction throughout its binding to glycine receptors (GlyRs), pentameric chloride channels that share structural and functional properties with type A γ-aminobutyric acid receptors (GABAAR). A large number of structurally diverse organic compounds have been identified as GlyR and GABAAR allosteric modulators, making these receptors attractive pharmacological targets. Taking into account the recent resolved crystal structures of GABAAR/neurosteroid complexes, and due to the high sequence identity between the GABAAR and GlyR transmembrane domains, in this work we applied molecular modeling methods to explore the neurosteroid binding to GlyR. Our results indicated that neurosteroid binding sites of GABAARs are also conserved in the GlyRs. Furthermore, docking and molecular dynamics simulations predicted that neurosteroids are stably recognized at these sites, providing precise information on the molecular basis of the neurosteroid binding mode to GlyR. The comparison of how allopregnanolone and pregnanolone 3-OH moieties are recognized by the GlyR binding pocket revealed significant differences that may be associated to opposite effects of these isomers on the GlyR response.
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Affiliation(s)
- Lautaro D Alvarez
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Ciudad Universitaria, Buenos Aires, C1428EGA, Argentina; CONICET - Universidad de Buenos Aires, UMYMFOR, Ciudad Universitaria, Buenos Aires, C1428EGA, Argentina.
| | - Adali Pecci
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Ciudad Universitaria, Buenos Aires, C1428EGA, Argentina; CONICET - Universidad de Buenos Aires, IFIBYNE, Ciudad Universitaria, Buenos Aires, C1428EGA, Argentina
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Abstract
Neurosteroids (NS) are the main modulators of γ-aminobutyric acid type A receptors (GABAARs), which are the ligand-gated channels target of the major inhibitory neurotransmitter in vertebrates. As a consequence of their ability to modify inhibitory functions in the brain, NS have high physiological and clinical relevance. Accumulated evidence has strongly suggested that NS binding sites were located in the GABAAR transmembrane domain; however the specific localization of these sites has remained an enigma for decades. Fortunately, recent resolution of GABAARs crystal structures, together with computational strategies applied to investigate the NS binding, has paved the way to rationalizing the molecular basis of NS modulation. This work reviews from a historical perspective the road followed for establishing the GABAAR/NS binding mode, from their initial molecular modeling to the latest findings. Furthermore, a comparative analysis describing the NS binding is provided, plus a preliminary analysis of putative NS sites in other assemblies.
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Affiliation(s)
- Lautaro D Alvarez
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Universitaria , Buenos Aires C1428EGA , Argentina.,UMYMFOR , CONICET-Universidad de Buenos Aires , Ciudad Universitaria , Buenos Aires C1428EGA , Argentina
| | - Adali Pecci
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Universitaria , Buenos Aires C1428EGA , Argentina.,IFIBYNE , CONICET-Universidad de Buenos Aires , Ciudad Universitaria , Buenos Aires C1428EGA , Argentina
| | - Dario A Estrin
- Departamento de Química Inorgánica Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires , Ciudad Universitaria , Buenos Aires C1428EGA , Argentina.,INQUIMAE , CONICET-Universidad de Buenos Aires , Ciudad Universitaria , Buenos Aires C1428EGA , Argentina
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Alvarez LD, Pecci A. Structure and dynamics of neurosteroid binding to the α 1β 2γ 2 GABA A receptor. J Steroid Biochem Mol Biol 2018; 182:72-80. [PMID: 29705269 DOI: 10.1016/j.jsbmb.2018.04.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/17/2018] [Accepted: 04/23/2018] [Indexed: 11/23/2022]
Abstract
Neurosteroids are the principal endogenous modulators of the γ-Aminobutyric acid receptors (GABAARs), pentameric membrane-bound proteins that can be assembled from at least 19 subunits. In the most abundant GABAAR arrangement (α1β2γ2), neurosteroids can potentiate the GABA action as well as produce a direct activation of the channel. The recent crystal structures of neurosteroids bound to α homopentameric GABAAR reveal binding to five equivalent sites. However, these results have been obtained using receptors that are not physiologically relevant, suggesting a need to investigate neurosteroid binding to heteropentameric receptors that exist in the central nervous system. In a previous work, we predicted the neurosteroid binding site by applying molecular modeling methods on the β3 homopentamer. Here we construct a homology model of the transmembrane domain of the heteropentameric α1β2γ2 receptor and then, by combining docking and molecular dynamics simulations, we analyzed neurosteroid binding. Results show that the five neurosteroid cavities are conserved in the α1β2γ2 receptor and all of them are able to bind neurosteroids. Two different binding modes were detected depending on the identity of the residue at position 241 in the transmembrane helix 1. These theoretical findings provide microscopic insights into neurosteroid binding at the heteropentameric GABAAR. The existence of two classes of sites may be associated with how neurosteroids modulate GABAAR. Our finding would represent the essential first step to reach a comprehensive understanding of how these endogenous molecules regulate the central nervous system.
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Affiliation(s)
- Lautaro D Alvarez
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, UMYMFOR, Buenos Aires, Argentina.
| | - Adali Pecci
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Buenos Aires, Argentina; CONICET - Universidad de Buenos Aires, IFIBYNE, Buenos Aires, Argentina
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Alphaxalone Binds in Inner Transmembrane β+-α- Interfaces of α1β3γ2 γ-Aminobutyric Acid Type A Receptors. Anesthesiology 2018; 128:338-351. [PMID: 29210709 DOI: 10.1097/aln.0000000000001978] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Neurosteroids like alphaxalone are potent anxiolytics, anticonvulsants, amnestics, and sedative-hypnotics, with effects linked to enhancement of γ-aminobutyric acid type A (GABAA) receptor gating in the central nervous system. Data locating neurosteroid binding sites on synaptic αβγ GABAA receptors are sparse and inconsistent. Some evidence points to outer transmembrane β-α interfacial pockets, near sites that bind the anesthetics etomidate and propofol. Other evidence suggests that steroids bind more intracellularly in β-α interfaces. METHODS The authors created 12 single-residue β3 cysteine mutations: β3T262C and β3T266C in β3-M2; and β3M283C, β3Y284C, β3M286C, β3G287C, β3F289C, β3V290C, β3F293C, β3L297C, β3E298C, and β3F301C in β3-M3 helices. The authors coexpressed α1 and γ2L with each mutant β3 subunit in Xenopus oocytes and electrophysiologically tested each mutant for covalent sulfhydryl modification by the water-soluble reagent para-chloromercuribenzenesulfonate. Then, the authors assessed whether receptor-bound alphaxalone, etomidate, or propofol blocked cysteine modification, implying steric hindrance. RESULTS Eleven mutant β3 subunits, when coexpressed with α1 and γ2L, formed functional channels that displayed varied sensitivities to the three anesthetics. Exposure to para-chloromercuribenzenesulfonate produced irreversible functional changes in ten mutant receptors. Protection by alphaxalone was observed in receptors with β3V290C, β3F293C, β3L297C, or β3F301C mutations. Both etomidate and propofol protected receptors with β3M286C or β3V290C mutations. Etomidate also protected β3F289C. In α1β3γ2L structural homology models, all these protected residues are located in transmembrane β-α interfaces. CONCLUSIONS Alphaxalone binds in transmembrane β-α pockets of synaptic GABAA receptors that are adjacent and intracellular to sites for the potent anesthetics etomidate and propofol.
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Wang S, Liu Q, Li X, Zhao X, Qiu L, Lin J. Possible binding sites and interactions of propanidid and AZD3043 within the γ-aminobutyric acid type A receptor (GABAAR). J Biomol Struct Dyn 2017; 36:3926-3937. [DOI: 10.1080/07391102.2017.1403959] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Shanshan Wang
- School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, P.R China
- Key Laboratory of Nuclear Medicine, Ministry of Health & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, P.R. China
| | - Qingzhu Liu
- Key Laboratory of Nuclear Medicine, Ministry of Health & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, P.R. China
| | - Xi Li
- School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, P.R China
- Key Laboratory of Nuclear Medicine, Ministry of Health & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, P.R. China
| | - Xueyu Zhao
- School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, P.R China
- Key Laboratory of Nuclear Medicine, Ministry of Health & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, P.R. China
| | - Ling Qiu
- School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, P.R China
- Key Laboratory of Nuclear Medicine, Ministry of Health & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, P.R. China
| | - Jianguo Lin
- Key Laboratory of Nuclear Medicine, Ministry of Health & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, P.R. China
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Nik AM, Pressly B, Singh V, Antrobus S, Hulsizer S, Rogawski MA, Wulff H, Pessah IN. Rapid Throughput Analysis of GABA A Receptor Subtype Modulators and Blockers Using DiSBAC 1(3) Membrane Potential Red Dye. Mol Pharmacol 2017; 92:88-99. [PMID: 28428226 DOI: 10.1124/mol.117.108563] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/12/2017] [Indexed: 02/03/2023] Open
Abstract
Fluorometric imaging plate reader membrane potential dye (FMP-Red-Dye) is a proprietary tool for basic discovery and high-throughput drug screening for G-protein-coupled receptors and ion channels. We optimized and validated this potentiometric probe to assay functional modulators of heterologous expressed GABAA receptor (GABAAR) isoforms (synaptic α1β3γ2, extrasynaptic α4β3δ, and β3 homopentomers). High-resolution mass spectrometry identified FMP-Red-Dye as 5,5'-(1-propen-1-yl-3-ylidene)bis[1,3-dimethyl-2-thio-barbituric acid]. GABAAR-expressing cells equilibrated with FMP-Red-Dye exhibited depolarized equilibrium membrane potentials compared with GABAAR-null cells. The channel blockers picrotoxin, fipronil, and tetramethylenedisulfotetramine, and the competitive antagonist bicuculline reduced fluorescence near the levels in GABAAR-null cells indicating that FMR-Red-Dye, a barbiturate derivative, activates GABAAR-mediated outward Cl- current in the absence of GABA. GABA caused concentration-dependent increases in fluorescence with rank order of potencies among GABAAR isoforms consistent with results from voltage-clamp experiments (EC50 values for α4β3δ, α1β3γ2, and β3 homopentamers were 6 ± 1, 40 ± 11, and >18 mM, respectively), whereas GABAAR-null cells were unresponsive. Neuroactive steroids (NAS) increased fluorescence of GABAAR expressing cells in the absence of GABA and demonstrated positive allosteric modulation in the presence of GABA, whereas benzodiazepines only exhibited positive allosteric modulator (PAM) activity. Of 20 NAS tested, allopregnanolone, (3α,5α,20E)-3-hydroxy-13,24-cyclo-18-norcholan-20-ene-21-carbonitrile, eltanolone, 5β-pregnan-3α,21-diol-20-one, and ganaxolone showed the highest potency. The FMP-Red-Dye-based assay described here provides a sensitive and quantitative method of assessing the activity of GABAAR agonists, antagonists, and PAMs on diverse GABAAR isoforms. The assay has a wide range of applications, including screening for antiseizure agents and identifying channel blockers of interest to insecticide discovery or biosecurity.
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Affiliation(s)
- Atefeh Mousavi Nik
- Department of Molecular Biosciences, School of Veterinary Medicine (A.M.N., S.A., S.H., I.N.P.), and Department of Pharmacology (B.P., V.S., M.A.R., H.W.), School of Medicine, University of California Davis, Davis, California; Department of Neurology, School of Medicine, University of California Davis, Sacramento, California (M.A.R.); and The Medical Investigation of Neurodevelopmental Disorders Institute, Sacramento, California (I.N.P.)
| | - Brandon Pressly
- Department of Molecular Biosciences, School of Veterinary Medicine (A.M.N., S.A., S.H., I.N.P.), and Department of Pharmacology (B.P., V.S., M.A.R., H.W.), School of Medicine, University of California Davis, Davis, California; Department of Neurology, School of Medicine, University of California Davis, Sacramento, California (M.A.R.); and The Medical Investigation of Neurodevelopmental Disorders Institute, Sacramento, California (I.N.P.)
| | - Vikrant Singh
- Department of Molecular Biosciences, School of Veterinary Medicine (A.M.N., S.A., S.H., I.N.P.), and Department of Pharmacology (B.P., V.S., M.A.R., H.W.), School of Medicine, University of California Davis, Davis, California; Department of Neurology, School of Medicine, University of California Davis, Sacramento, California (M.A.R.); and The Medical Investigation of Neurodevelopmental Disorders Institute, Sacramento, California (I.N.P.)
| | - Shane Antrobus
- Department of Molecular Biosciences, School of Veterinary Medicine (A.M.N., S.A., S.H., I.N.P.), and Department of Pharmacology (B.P., V.S., M.A.R., H.W.), School of Medicine, University of California Davis, Davis, California; Department of Neurology, School of Medicine, University of California Davis, Sacramento, California (M.A.R.); and The Medical Investigation of Neurodevelopmental Disorders Institute, Sacramento, California (I.N.P.)
| | - Susan Hulsizer
- Department of Molecular Biosciences, School of Veterinary Medicine (A.M.N., S.A., S.H., I.N.P.), and Department of Pharmacology (B.P., V.S., M.A.R., H.W.), School of Medicine, University of California Davis, Davis, California; Department of Neurology, School of Medicine, University of California Davis, Sacramento, California (M.A.R.); and The Medical Investigation of Neurodevelopmental Disorders Institute, Sacramento, California (I.N.P.)
| | - Michael A Rogawski
- Department of Molecular Biosciences, School of Veterinary Medicine (A.M.N., S.A., S.H., I.N.P.), and Department of Pharmacology (B.P., V.S., M.A.R., H.W.), School of Medicine, University of California Davis, Davis, California; Department of Neurology, School of Medicine, University of California Davis, Sacramento, California (M.A.R.); and The Medical Investigation of Neurodevelopmental Disorders Institute, Sacramento, California (I.N.P.)
| | - Heike Wulff
- Department of Molecular Biosciences, School of Veterinary Medicine (A.M.N., S.A., S.H., I.N.P.), and Department of Pharmacology (B.P., V.S., M.A.R., H.W.), School of Medicine, University of California Davis, Davis, California; Department of Neurology, School of Medicine, University of California Davis, Sacramento, California (M.A.R.); and The Medical Investigation of Neurodevelopmental Disorders Institute, Sacramento, California (I.N.P.)
| | - Isaac N Pessah
- Department of Molecular Biosciences, School of Veterinary Medicine (A.M.N., S.A., S.H., I.N.P.), and Department of Pharmacology (B.P., V.S., M.A.R., H.W.), School of Medicine, University of California Davis, Davis, California; Department of Neurology, School of Medicine, University of California Davis, Sacramento, California (M.A.R.); and The Medical Investigation of Neurodevelopmental Disorders Institute, Sacramento, California (I.N.P.)
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Cascella M, Schiavone V, Muzio MR, Cuomo A. Consciousness fluctuation during general anesthesia: a theoretical approach to anesthesia awareness and memory modulation. Curr Med Res Opin 2016; 32:1351-9. [PMID: 27046232 DOI: 10.1080/03007995.2016.1174679] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
With anesthesia awareness as a model of study we debate the both fascinating and dangerous phenomenon called consciousness fluctuation that takes place during surgical anesthesia. In accordance with current scientific knowledge this paradox is the consequence of our limits in both precise knowledge of anesthesia mechanisms and our inability to accurately assess the level of anesthesia with brain monitoring. We also focus on the relationships between memory and anesthesia, as well as the possibility of interfering with memory during general anesthesia.
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Affiliation(s)
- Marco Cascella
- a Division of Anesthesia, Department of Anesthesia, Endoscopy and Cardiology , Istituto Nazionale Tumori "Fondazione G. Pascale" - IRCCS , Naples , Italy
| | - Vincenzo Schiavone
- b Division of Anesthesia and Intensive Care , Hospital "Pineta Grande" , Castel Volturno , Italy
| | - Maria Rosaria Muzio
- c Division of Infantile Neuropsychiatry , UOMI - Maternal and Infant Health , Torre del Greco , Naples , Italy
| | - Arturo Cuomo
- a Division of Anesthesia, Department of Anesthesia, Endoscopy and Cardiology , Istituto Nazionale Tumori "Fondazione G. Pascale" - IRCCS , Naples , Italy
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Puthenkalam R, Hieckel M, Simeone X, Suwattanasophon C, Feldbauer RV, Ecker GF, Ernst M. Structural Studies of GABAA Receptor Binding Sites: Which Experimental Structure Tells us What? Front Mol Neurosci 2016; 9:44. [PMID: 27378845 PMCID: PMC4910578 DOI: 10.3389/fnmol.2016.00044] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 05/25/2016] [Indexed: 01/23/2023] Open
Abstract
Atomic resolution structures of cys-loop receptors, including one of a γ-aminobutyric acid type A receptor (GABAA receptor) subtype, allow amazing insights into the structural features and conformational changes that these pentameric ligand-gated ion channels (pLGICs) display. Here we present a comprehensive analysis of more than 30 cys-loop receptor structures of homologous proteins that revealed several allosteric binding sites not previously described in GABAA receptors. These novel binding sites were examined in GABAA receptor homology models and assessed as putative candidate sites for allosteric ligands. Four so far undescribed putative ligand binding sites were proposed for follow up studies based on their presence in the GABAA receptor homology models. A comprehensive analysis of conserved structural features in GABAA and glycine receptors (GlyRs), the glutamate gated ion channel, the bacterial homologs Erwinia chrysanthemi (ELIC) and Gloeobacter violaceus GLIC, and the serotonin type 3 (5-HT3) receptor was performed. The conserved features were integrated into a master alignment that led to improved homology models. The large fragment of the intracellular domain that is present in the structure of the 5-HT3 receptor was utilized to generate GABAA receptor models with a corresponding intracellular domain fragment. Results of mutational and photoaffinity ligand studies in GABAA receptors were analyzed in the light of the model structures. This led to an assignment of candidate ligands to two proposed novel pockets, candidate binding sites for furosemide and neurosteroids in the trans-membrane domain were identified. The homology models can serve as hypotheses generators, and some previously controversial structural interpretations of biochemical data can be resolved in the light of the presented multi-template approach to comparative modeling. Crystal and cryo-EM microscopic structures of the closest homologs that were solved in different conformational states provided important insights into structural rearrangements of binding sites during conformational transitions. The impact of structural variation and conformational motion on the shape of the investigated binding sites was analyzed. Rules for best template and alignment choice were obtained and can generally be applied to modeling of cys-loop receptors. Overall, we provide an updated structure based view of ligand binding sites present in GABAA receptors.
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Affiliation(s)
- Roshan Puthenkalam
- Department of Molecular Neurosciences, Medical University of ViennaVienna, Austria
| | - Marcel Hieckel
- Department of Molecular Neurosciences, Medical University of ViennaVienna, Austria
| | - Xenia Simeone
- Department of Molecular Neurosciences, Medical University of ViennaVienna, Austria
| | | | - Roman V. Feldbauer
- Austrian Research Institute for Artificial Intelligence (OFAI)Vienna, Austria
| | - Gerhard F. Ecker
- Department of Pharmaceutical Chemistry, University of ViennaVienna, Austria
| | - Margot Ernst
- Department of Molecular Neurosciences, Medical University of ViennaVienna, Austria
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Drusin SI, Suarez IP, Gauto DF, Rasia RM, Moreno DM. dsRNA-protein interactions studied by molecular dynamics techniques. Unravelling dsRNA recognition by DCL1. Arch Biochem Biophys 2016; 596:118-25. [PMID: 26987516 DOI: 10.1016/j.abb.2016.03.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 03/02/2016] [Accepted: 03/09/2016] [Indexed: 12/30/2022]
Abstract
Double stranded RNA (dsRNA) participates in several biological processes, where RNA molecules acquire secondary structure inside the cell through base complementarity. The double stranded RNA binding domain (dsRBD) is one of the main protein folds that is able to recognize and bind to dsRNA regions. The N-terminal dsRBD of DCL1 in Arabidopsis thaliana (DCL1-1), in contrast to other studied dsRBDs, lacks a stable structure, behaving as an intrinsically disordered protein. DCL1-1 does however recognize dsRNA by acquiring a canonical fold in the presence of its substrate. Here we present a detailed modeling and molecular dynamics study of dsRNA recognition by DCL1-1. We found that DCL1-1 forms stable complexes with different RNAs and we characterized the residues involved in binding. Although the domain shows a binding loop substantially shorter than other homologs, it can still interact with the dsRNA and results in bending of the dsRNA A-type helix. Furthermore, we found that R8, a non-conserved residue located in the first dsRNA binding region, recognizes preferentially mismatched base pairs. We discuss our findings in the context of the function of DCL1-1 within the microRNA processing complex.
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Affiliation(s)
- Salvador I Drusin
- Instituto de Biología Molecular y Celular de Rosario (CONICET-UNR), Ocampo y Esmeralda, Predio CCT, 2000 Rosario, Argentina; Área Física, Departamento de Químico-Física, Facultad de Ciencias, Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Santa Fe, Argentina
| | - Irina P Suarez
- Instituto de Biología Molecular y Celular de Rosario (CONICET-UNR), Ocampo y Esmeralda, Predio CCT, 2000 Rosario, Argentina
| | - Diego F Gauto
- Instituto de Biología Molecular y Celular de Rosario (CONICET-UNR), Ocampo y Esmeralda, Predio CCT, 2000 Rosario, Argentina
| | - Rodolfo M Rasia
- Instituto de Biología Molecular y Celular de Rosario (CONICET-UNR), Ocampo y Esmeralda, Predio CCT, 2000 Rosario, Argentina; Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Santa Fe, Argentina
| | - Diego M Moreno
- Instituto de Química de Rosario (CONICET-UNR), Suipacha 570, S2002LRK Rosario, Santa Fe, Argentina; Área Inorgánica, Departamento de Químico-Física, Facultad de Ciencias, Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Santa Fe, Argentina.
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