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Witkin JM, Barrett JE. ANXIOLYTICS: Origins, drug discovery, and mechanisms. Pharmacol Biochem Behav 2024; 245:173858. [PMID: 39178918 DOI: 10.1016/j.pbb.2024.173858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Revised: 08/12/2024] [Accepted: 08/15/2024] [Indexed: 08/26/2024]
Abstract
Anxiety is a part of the human condition and has been managed by psychoactive substances for centuries. The current medical need and societal demand for anxiolytic medicines has not abated. The present overview provides a brief historical introduction to the discovery of modern age anxiolytics that include the benzodiazepines together with a discussion of the continuing medical need for new antianxiety medications. The paper also discusses the use and impact of behavioral pharmacology in the preclinical development of anxiolytics. The review then highlights the diversity of mechanisms for creating a new generation of anxiolytics through mechanisms beyond the potentiation of GABAA receptors and the blockade of monoamine uptake. A discussion then follows on the behavioral specificity of action of anxiolytics that includes the concept of creating an anxioselective drug, one that targets anxiety without producing untoward effects that include sedation and dependence. The use of anxiolytics in the treatment of other conditions such as substance use disorder is also briefly reviewed. Finally, a brief summary of the current status of anxiolytic drug development is provided. The review concludes with the idea that despite a host of anxiolytic drugs, the lack of efficacy in some patients and the side-effects and safety issues associated with some of these medications demands alternative medicines. Current preclinical and clinical research is ongoing with the goal of identifying such compounds.
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Affiliation(s)
- Jeffrey M Witkin
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent Hospital, Indianapolis, IN, USA.
| | - James E Barrett
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA.
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2
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Cerne R, Smith JL, Chrzanowska A, Lippa A. Nonsedating anxiolytics. Pharmacol Biochem Behav 2024; 245:173895. [PMID: 39461622 DOI: 10.1016/j.pbb.2024.173895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2024] [Revised: 09/30/2024] [Accepted: 10/08/2024] [Indexed: 10/29/2024]
Abstract
Anxiety disorders are the most prevalent psychiatric pathology with substantial cost to society, but the existing treatments are often inadequate. This has rekindled the interest in the GABAA-receptor (GABAAR) positive allosteric modulator (PAM) compounds, which have a long history in treatment of anxiety beginning with diazepam, chlordiazepoxide, and alprazolam. While the GABAAR PAMs possess remarkable anxiolytic efficacy, they have fallen out of favor due to a host of adverse effects including sedation, motor impairment, addictive potential and tolerance development. A substantial effort was thus devoted to the design of GABAAR PAMs as anxiolytics with reduced sedative liabilities. Several non-benzodiazepine (BZD) GABAAPAMs progressed to clinical trials (bretazenil, abecarnil, alpidem, and ocinaplon) with alpidem obtaining regulatory approval as anxiolytic, but later withdrawn from market due to hepatotoxicity. Advances in molecular biology gave birth to a host of subtype selective GABAAR-PAMs which suffered from signs of sedation and motor impairment and only three compounds progressed to proof-of-concept studies (TPA-023, AZD7325 and PF-06372865). TPA-023 was terminated due to toxicity in preclinical species while AZD7325 and PF-06372865 did not achieve efficacy endpoints in patients. We highlight a new compound, KRM-II-81, that is an imidazodiazepine selective for GABAAR containing α2/3 and β3 proteins. In preclinical studies KRM-II-81 produced anxiolytic-like effects but with minimal sedation, respiratory depression, and abuse liability. Thus, KRM-II-81 is a newly discovered, non- BZD anxiolytic compound, which targets a selective population of GABAAR for improved therapeutic gain and reduced side effects.
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Affiliation(s)
- Rok Cerne
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN, USA; RespireRx Pharmaceuticals Inc., Glen Rock, NJ, USA; Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
| | - Jodi L Smith
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN, USA
| | | | - Arnold Lippa
- RespireRx Pharmaceuticals Inc., Glen Rock, NJ, USA
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3
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Klein P, Kaminski RM, Koepp M, Löscher W. New epilepsy therapies in development. Nat Rev Drug Discov 2024; 23:682-708. [PMID: 39039153 DOI: 10.1038/s41573-024-00981-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2024] [Indexed: 07/24/2024]
Abstract
Epilepsy is a common brain disorder, characterized by spontaneous recurrent seizures, with associated neuropsychiatric and cognitive comorbidities and increased mortality. Although people at risk can often be identified, interventions to prevent the development of the disorder are not available. Moreover, in at least 30% of patients, epilepsy cannot be controlled by current antiseizure medications (ASMs). As a result of considerable progress in epilepsy genetics and the development of novel disease models, drug screening technologies and innovative therapeutic modalities over the past 10 years, more than 200 novel epilepsy therapies are currently in the preclinical or clinical pipeline, including many treatments that act by new mechanisms. Assisted by diagnostic and predictive biomarkers, the treatment of epilepsy is undergoing paradigm shifts from symptom-only ASMs to disease prevention, and from broad trial-and-error treatments for seizures in general to mechanism-based treatments for specific epilepsy syndromes. In this Review, we assess recent progress in ASM development and outline future directions for the development of new therapies for the treatment and prevention of epilepsy.
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Affiliation(s)
- Pavel Klein
- Mid-Atlantic Epilepsy and Sleep Center, Bethesda, MD, USA.
| | | | - Matthias Koepp
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Wolfgang Löscher
- Translational Neuropharmacology Lab., NIFE, Department of Experimental Otology of the ENT Clinics, Hannover Medical School, Hannover, Germany.
- Center for Systems Neuroscience, Hannover, Germany.
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Zhao H, Liu Y, Cai N, Liao X, Tang L, Wang Y. Endocannabinoid Hydrolase Inhibitors: Potential Novel Anxiolytic Drugs. Drug Des Devel Ther 2024; 18:2143-2167. [PMID: 38882045 PMCID: PMC11179644 DOI: 10.2147/dddt.s462785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 05/27/2024] [Indexed: 06/18/2024] Open
Abstract
Over the past decade, the idea of targeting the endocannabinoid system to treat anxiety disorders has received increasing attention. Previous studies focused more on developing cannabinoid receptor agonists or supplementing exogenous cannabinoids, which are prone to various adverse effects due to their strong pharmacological activity and poor receptor selectivity, limiting their application in clinical research. Endocannabinoid hydrolase inhibitors are considered to be the most promising development strategies for the treatment of anxiety disorders. More recent efforts have emphasized that inhibition of two major endogenous cannabinoid hydrolases, monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH), indirectly activates cannabinoid receptors by increasing endogenous cannabinoid levels in the synaptic gap, circumventing receptor desensitization resulting from direct enhancement of endogenous cannabinoid signaling. In this review, we comprehensively summarize the anxiolytic effects of MAGL and FAAH inhibitors and their potential pharmacological mechanisms, highlight reported novel inhibitors or natural products, and provide an outlook on future directions in this field.
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Affiliation(s)
- Hongqing Zhao
- Science & Technology Innovation Center, Hunan University of Chinese Medicine, Changsha, Hunan, People’s Republic of China
- Hunan Key Laboratory of Traditional Chinese Medicine Prevention & Treatment of Depressive Diseases, Changsha, Hunan, People’s Republic of China
| | - Yang Liu
- Science & Technology Innovation Center, Hunan University of Chinese Medicine, Changsha, Hunan, People’s Republic of China
- Hunan Key Laboratory of Traditional Chinese Medicine Prevention & Treatment of Depressive Diseases, Changsha, Hunan, People’s Republic of China
| | - Na Cai
- Outpatient Department, the First Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, Hunan, People’s Republic of China
| | - Xiaolin Liao
- Science & Technology Innovation Center, Hunan University of Chinese Medicine, Changsha, Hunan, People’s Republic of China
- Hunan Key Laboratory of Traditional Chinese Medicine Prevention & Treatment of Depressive Diseases, Changsha, Hunan, People’s Republic of China
| | - Lin Tang
- Hunan Key Laboratory of Traditional Chinese Medicine Prevention & Treatment of Depressive Diseases, Changsha, Hunan, People’s Republic of China
- Department of Pharmacy, the First Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, Hunan, People’s Republic of China
| | - Yuhong Wang
- Science & Technology Innovation Center, Hunan University of Chinese Medicine, Changsha, Hunan, People’s Republic of China
- Hunan Key Laboratory of Traditional Chinese Medicine Prevention & Treatment of Depressive Diseases, Changsha, Hunan, People’s Republic of China
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MacLean A, Chappell AS, Kranzler J, Evrard A, Monchal H, Roucard C. BAER-101, a selective potentiator of α2- and α3-containing GABA A receptors, fully suppresses spontaneous cortical spike-wave discharges in Genetic Absence Epilepsy Rats from Strasbourg (GAERS). Drug Dev Res 2024; 85:e22160. [PMID: 38380694 DOI: 10.1002/ddr.22160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/29/2024] [Accepted: 01/31/2024] [Indexed: 02/22/2024]
Abstract
BAER-101 (formerly AZD7325) is a selective partial potentiator of α2/3-containing γ-amino-butyric acid A receptors (GABAARs) and produces minimal sedation and dizziness. Antiseizure effects in models of Dravet and Fragile X Syndromes have been published. BAER-101 has been administered to over 700 healthy human volunteers and patients where it was found to be safe and well tolerated. To test the extent of the antiseizure activity of BAER-1010, we tested BAER-101 in the Genetic Absence Epilepsy Rats from Strasbourg (GAERS) model, a widely used and translationally relevant model. GAERS rats with recording electrodes bilaterally located over the frontal and parietal cortices were used. Electroencepholographic (EEG) signals in freely moving awake rats were analyzed for spike-wave discharges (SWDs). BAER-101 was administered orally at doses of 0.3-100 mg/kg and diazepam was used as a positive control using a cross-over protocol with a wash-out period between treatments. The number of SWDs was dose-dependently reduced by BAER-101 with 0.3 mg/kg being the minimally effective dose (MED). The duration of and total time in SWDs were also reduced by BAER-101. Concentrations of drug in plasma achieved an MED of 10.1 nM, exceeding the Ki for α2 or α3, but 23 times lower than the Ki for α5-GABAARs. No adverse events were observed up to a dose 300× MED. The data support the possibility of antiseizure efficacy without the side effects associated with other GABAAR subtypes. This is the first report of an α2/3-selective GABA PAM suppressing seizures in the GAERS model. The data encourage proceeding to test BAER-101 in patients with epilepsy.
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Uusi-Oukari M, Korpi ER. GABAergic mechanisms in alcohol dependence. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2024; 175:75-123. [PMID: 38555121 DOI: 10.1016/bs.irn.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
The target of alcohol's effect on the central nervous system has been sought for more than 50 years in the brain's GABA system. The behavioral and emotional effects of alcohol in humans and rodents are very similar to those of barbiturates and benzodiazepines, and GABAA receptors have been shown to be one of the sites of alcohol action. The mechanisms of GABAergic inhibition have been a hotspot of research but have turned out to be complex and controversial. Genetics support the involvement of some GABAA receptor subunits in the development of alcohol dependence and in alcohol use disorders (AUD). Since the effect of alcohol on the GABAA system resembles that of a GABAergic positive modulator, it may be possible to develop GABAergic drug treatments that could substitute for alcohol. The adaptation mechanisms of the GABA system and the plasticity of the brain are a big challenge for drug development: the drugs that act on GABAA receptors developed so far also may cause adaptation and development of additional addiction. Human polymorphisms should be studied further to get insight about how they affect receptor function, expression or other factors to make reasonable predictions/hypotheses about what non-addictive interventions would help in alcohol dependence and AUD.
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Affiliation(s)
- Mikko Uusi-Oukari
- Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Esa R Korpi
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
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Sharmin D, Divović B, Ping X, Cerne R, Smith JL, Rezvanian S, Mondal P, Meyer MJ, Kiley ME, Arnold LA, Mian MY, Pandey KP, Jin X, Mitrović JR, Djorović D, Lippa A, Cook JM, Golani LK, Scholze P, Savić MM, Witkin JM. New Imidazodiazepine Analogue, 5-(8-Bromo-6-(pyridin-2-yl)-4 H-benzo[ f]imidazo[1,5- a][1,4]diazepin-3-yl)oxazole, Provides a Simplified Synthetic Scheme, High Oral Plasma and Brain Exposures, and Produces Antiseizure Efficacy in Mice, and Antiepileptogenic Activity in Neural Networks in Brain Slices from a Patient with Mesial Temporal Lobe Epilepsy. ACS Chem Neurosci 2024; 15:517-526. [PMID: 38175916 DOI: 10.1021/acschemneuro.3c00555] [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] [Indexed: 01/06/2024] Open
Abstract
KRM-II-81 (1) is an imidazodiazepine GABAA receptor (GABAAR) potentiator with broad antiseizure efficacy and a low sedative burden. A brominated analogue, DS-II-73 (5), was synthesized and pharmacologically characterized as a potential backup compound as KRM-II-81 moves forward into development. The synthesis from 2-amino-5-bromophenyl)(pyridin-2yl)methanone (6) was processed in five steps with an overall yield of 38% and without the need for a palladium catalyst. GABAAR binding occurred with a Ki of 150 nM, and only 3 of 41 screened binding sites produced inhibition ≥50% at 10 μM, and the potency to induce cytotoxicity was ≥240 mM. DS-II-73 was selective for α2/3/5- over that of α1-containing GABAARs. Oral exposure of plasma and brain of rats was more than sufficient to functionally impact GABAARs. Tonic convulsions in mice and lethality induced by pentylenetetrazol were suppressed by DS-II-73 after oral administration and latencies to clonic and tonic seizures were prolonged. Cortical slice preparations from a patient with pharmacoresistant epilepsy (mesial temporal lobe) showed decreases in the frequency of local field potentials by DS-II-73. As with KRM-II-81, the motor-impairing effects of DS-II-73 were low compared to diazepam. Molecular docking studies of DS-II-73 with the α1β3γ2L-configured GABAAR showed low interaction with α1His102 that is suggested as a potential molecular mechanism for its low sedative side effects. These findings support the viability of DS-II-73 as a backup molecule for its ethynyl analogue, KRM-II-81, with the human tissue data providing translational credibility.
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Affiliation(s)
- Dishary Sharmin
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Branka Divović
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Belgrade 11221, Serbia
| | - Xingjie Ping
- Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, Indiana 46202, United States
| | - Rok Cerne
- Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, Indiana 46202, United States
- Laboratory of Antiepileptic Drug Discovery, St. Vincent's Hospital, Indianapolis, Indiana 46260, United States
- RespireRx Pharmaceuticals Inc, Glen Rock, New Jersey 07452, United States
- Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, Ljubljana 1000, Slovenia
| | - Jodi L Smith
- Laboratory of Antiepileptic Drug Discovery, St. Vincent's Hospital, Indianapolis, Indiana 46260, United States
| | - Sepideh Rezvanian
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Prithu Mondal
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Michelle Jean Meyer
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Molly E Kiley
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Leggy A Arnold
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Md Yeunus Mian
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Kamal P Pandey
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Xiaoming Jin
- Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, Indiana 46202, United States
| | - Jelena R Mitrović
- Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, University of Belgrade, Belgrade 11221, Serbia
| | - Djordje Djorović
- Institute of Anatomy, School of Medicine, University of Belgrade, Belgrade 11221, Serbia
| | - Arnold Lippa
- RespireRx Pharmaceuticals Inc, Glen Rock, New Jersey 07452, United States
| | - James M Cook
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
- RespireRx Pharmaceuticals Inc, Glen Rock, New Jersey 07452, United States
| | - Lalit K Golani
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna 1090, Austria
| | - Miroslav M Savić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Belgrade 11221, Serbia
| | - Jeffrey M Witkin
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
- Laboratory of Antiepileptic Drug Discovery, St. Vincent's Hospital, Indianapolis, Indiana 46260, United States
- RespireRx Pharmaceuticals Inc, Glen Rock, New Jersey 07452, United States
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Sieghart W. Why Can Modulation of α6-Containing GABA A Receptors Reduce the Symptoms of Multiple Neuropsychiatric Disorders? ARCHIVES OF PHARMACOLOGY AND THERAPEUTICS 2024; 6:047. [PMID: 38283799 PMCID: PMC7615572 DOI: 10.33696/pharmacol.6.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
α6-containing GABAA receptors (α6GABAARs) are strongly expressed in cerebellar granule cells, where they mediate a correctly timed and precise coordination of all muscle groups that execute behavior and protect the brain from information overflow. Recently, it was demonstrated that positive modulators with a high selectivity for α6GABAARs (α6-modulators) can reduce the symptoms of multiple neuropsychiatric disorders in respective animal models to an extent comparable with established clinical therapeutics. Here, these incredible findings are discussed and explained. So far, the beneficial actions of α6-modulators and their lack of side effects have only been demonstrated in animal models of the respective disorders. Preclinical studies have demonstrated their suitability for further drug development. Future human studies have to investigate their safety and possible side effects, and to clarify to which extent individual symptoms of the respective disorders can be reduced by α6-modulators in patients during acute and chronic dosing. Due to their broad therapeutic potential, α6-modulators might become a valuable new treatment option for multiple neuropsychiatric disorders.
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Affiliation(s)
- Werner Sieghart
- Center for Brain Research, Department of Molecular Neurosciences, Medical University Vienna, Spitalgasse 4, A-1090 Vienna, Austria
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9
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Thompson SM. Modulators of GABA A receptor-mediated inhibition in the treatment of neuropsychiatric disorders: past, present, and future. Neuropsychopharmacology 2024; 49:83-95. [PMID: 37709943 PMCID: PMC10700661 DOI: 10.1038/s41386-023-01728-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 07/14/2023] [Accepted: 08/08/2023] [Indexed: 09/16/2023]
Abstract
The predominant inhibitory neurotransmitter in the brain, γ-aminobutyric acid (GABA), acts at ionotropic GABAA receptors to counterbalance excitation and regulate neuronal firing. GABAA receptors are heteropentameric channels comprised from subunits derived from 19 different genes. GABAA receptors have one of the richest and well-developed pharmacologies of any therapeutic drug target, including agonists, antagonists, and positive and negative allosteric modulators (PAMs, NAMs). Currently used PAMs include benzodiazepine sedatives and anxiolytics, barbiturates, endogenous and synthetic neurosteroids, and general anesthetics. In this article, I will review evidence that these drugs act at several distinct binding sites and how they can be used to alter the balance between excitation and inhibition. I will also summarize existing literature regarding (1) evidence that changes in GABAergic inhibition play a causative role in major depression, anxiety, postpartum depression, premenstrual dysphoric disorder, and schizophrenia and (2) whether and how GABAergic drugs exert beneficial effects in these conditions, focusing on human studies where possible. Where these classical therapeutics have failed to exert benefits, I will describe recent advances in clinical and preclinical drug development. I will also highlight opportunities to advance a generation of GABAergic therapeutics, such as development of subunit-selective PAMs and NAMs, that are engendering hope for novel tools to treat these devastating conditions.
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Affiliation(s)
- Scott M Thompson
- Center for Novel Therapeutics, Department of Psychiatry, University of Colorado School of Medicine, 12700 E. 19th Ave., Aurora, CO, 80045, USA.
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Nakakubo S, Hiramatsu Y, Goto T, Kimura S, Narugami M, Nakajima M, Ueda Y, Shiraishi H, Manabe A, Sharmin D, Cook JM, Egawa K. Therapeutic effects of KRM-II-81, positive allosteric modulator for α2/3 subunit containing GABA A receptors, in a mouse model of Dravet syndrome. Front Pharmacol 2023; 14:1273633. [PMID: 37849734 PMCID: PMC10577232 DOI: 10.3389/fphar.2023.1273633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 09/21/2023] [Indexed: 10/19/2023] Open
Abstract
Introduction: Dravet syndrome (DS) is an intractable epilepsy syndrome concomitant with neurodevelopmental disorder that begins in infancy. DS is dominantly caused by mutations in the SCN1A gene, which encodes the α subunit of a voltage-gated Na channel. Pre-synaptic inhibitory dysfunction is regarded as the pathophysiological mechanism, but an effective strategy for ameliorating seizures and behavioral problems is still under development. Here, we evaluated the effects of KRM-II-81, a newly developed positive allosteric modulator for α 2/3 subunit containing GABAA receptors (α2/3-GABAAR) in a mice model of DS both in vivo and at the neuronal level. Methods: We used knock-in mice carrying a heterozygous, clinically relevant SCN1A mutation (background strain: C57BL/6 J) as a model of the DS (Scn1a WT/A1783V mice), knock-in mouse strain carrying a heterozygous, clinically relevant SCN1A mutation (A1783V). Seizure threshold and locomotor activity was evaluated by using the hyperthermia-induced seizure paradigm and open filed test, respectively. Anxiety-like behavior was assessed by avoidance of the center region in locomotor activity. We estimated a sedative effect by the total distance traveled in locomotor activity and grip strength. Inhibitory post synaptic currents (IPSCs) were recorded from a hippocampal CA1 pyramidal neuron in an acutely prepared brain slice. Results: KRM-II-81 significantly increased the seizure threshold of Scn1a WT/A1783V mice in a dose-dependent manner. A low dose of KRM-II-81 specifically improved anxiety-like behavior of Scn1a WT/A1783V mice. A sedative effect was induced by relatively high dose of KRM-II-81 in Scn1a WT/A1783V mice, the dose of which was not sedative for WT mice. KRM-II-81 potentiated IPSCs by increasing its decay time kinetics. This effect was more prominent in Scn1a WT/A1783V mice. Discussion: Higher activation of α2/3-GABAAR by KRM-II-81 suggests a compensatory modification of post synaptic inhibitory function against presynaptic inhibitory dysfunction in Scn1a WT/A1783V. The increased sensitivity for KRM-II-81 may be relevant to the distinct dose-dependent effect in each paradigm of Scn1a WT/A1783V mice. Conclusion: Selective activation for α2/3-GABAAR by KRM-II-81 could be potential therapeutic strategy for treating seizures and behavioral problems in DS.
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Affiliation(s)
- Sachiko Nakakubo
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Yasuyoshi Hiramatsu
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Takeru Goto
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Syuhei Kimura
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Masashi Narugami
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Midori Nakajima
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Yuki Ueda
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Atsushi Manabe
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
| | - Dishary Sharmin
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - James M. Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, United States
| | - Kiyoshi Egawa
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Japan
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Kaplan K, Hunsberger HC. Benzodiazepine-induced anterograde amnesia: detrimental side effect to novel study tool. Front Pharmacol 2023; 14:1257030. [PMID: 37781704 PMCID: PMC10536168 DOI: 10.3389/fphar.2023.1257030] [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: 07/11/2023] [Accepted: 09/04/2023] [Indexed: 10/03/2023] Open
Abstract
Benzodiazepines (BZDs) are anxiolytic drugs that act on GABAa receptors and are used to treat anxiety disorders. However, these drugs come with the detrimental side effect of anterograde amnesia, or the inability to form new memories. In this review we discuss, behavioral paradigms, sex differences and hormonal influences affecting BZD-induced amnesia, molecular manipulations, including the knockout of GABAa receptor subunits, and regional studies utilizing lesion and microinjection techniques targeted to the hippocampus and amygdala. Additionally, the relationship between BZD use and cognitive decline related to Alzheimer's disease is addressed, as there is a lack of consensus on whether these drugs are involved in inducing or accelerating pathological cognitive deficits. This review aims to inspire new research directions, as there is a gap in knowledge in understanding the cellular and molecular mechanisms behind BZD-induced amnesia. Understanding these mechanisms will allow for the development of alternative treatments and potentially allow BZDs to be used as a novel tool to study Alzheimer's disease.
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Affiliation(s)
- Kameron Kaplan
- Center for Neurodegenerative Diseases and Therapeutics, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
- Department of Neuroscience, Rosalind Franklin University of Medicine and Science, The Chicago Medical School, North Chicago, IL, United States
| | - Holly Christian Hunsberger
- Center for Neurodegenerative Diseases and Therapeutics, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
- Department of Neuroscience, Rosalind Franklin University of Medicine and Science, The Chicago Medical School, North Chicago, IL, United States
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Barresi E, Robello M, Baglini E, Poggetti V, Viviano M, Salerno S, Da Settimo F, Taliani S. Indol-3-ylglyoxylamide as Privileged Scaffold in Medicinal Chemistry. Pharmaceuticals (Basel) 2023; 16:997. [PMID: 37513909 PMCID: PMC10386336 DOI: 10.3390/ph16070997] [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: 06/12/2023] [Revised: 07/05/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
In recent years, indolylglyoxylamide-based derivatives have received much attention due to their application in drug design and discovery, leading to the development of a wide array of compounds that have shown a variety of pharmacological activities. Combining the indole nucleus, already validated as a "privileged structure," with the glyoxylamide function allowed for an excellent template to be obtained that is suitable to a great number of structural modifications aimed at permitting interaction with specific molecular targets and producing desirable therapeutic effects. The present review provides insight into how medicinal chemists have elegantly exploited the indolylglyoxylamide moiety to obtain potentially useful drugs, with a particular focus on compounds exhibiting activity in in vivo models or reaching clinical trials. All in all, this information provides exciting new perspectives on existing data that can be useful in further design of indolylglyoxylamide-based molecules with interesting pharmacological profiles. The aim of this report is to present an update of collection data dealing with the employment of this moiety in the rational design of compounds that are able to interact with a specific target, referring to the last 20 years.
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Affiliation(s)
- Elisabetta Barresi
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Marco Robello
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Emma Baglini
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Valeria Poggetti
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Monica Viviano
- Department of Pharmacy, University of Salerno, 84084 Fisciano, Italy
| | - Silvia Salerno
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Federico Da Settimo
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Sabrina Taliani
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
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Koniuszewski F, Vogel FD, Dajić I, Seidel T, Kunze M, Willeit M, Ernst M. Navigating the complex landscape of benzodiazepine- and Z-drug diversity: insights from comprehensive FDA adverse event reporting system analysis and beyond. Front Psychiatry 2023; 14:1188101. [PMID: 37457785 PMCID: PMC10345211 DOI: 10.3389/fpsyt.2023.1188101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/05/2023] [Indexed: 07/18/2023] Open
Abstract
Introduction Medications which target benzodiazepine (BZD) binding sites of GABAA receptors (GABAARs) have been in widespread use since the nineteen-sixties. They carry labels as anxiolytics, hypnotics or antiepileptics. All benzodiazepines and several nonbenzodiazepine Z-drugs share high affinity binding sites on certain subtypes of GABAA receptors, from which they can be displaced by the clinically used antagonist flumazenil. Additional binding sites exist and overlap in part with sites used by some general anaesthetics and barbiturates. Despite substantial preclinical efforts, it remains unclear which receptor subtypes and ligand features mediate individual drug effects. There is a paucity of literature comparing clinically observed adverse effect liabilities across substances in methodologically coherent ways. Methods In order to examine heterogeneity in clinical outcome, we screened the publicly available U.S. FDA adverse event reporting system (FAERS) database for reports of individual compounds and analyzed them for each sex individually with the use of disproportionality analysis. The complementary use of physico-chemical descriptors provides a molecular basis for the analysis of clinical observations of wanted and unwanted drug effects. Results and Discussion We found a multifaceted FAERS picture, and suggest that more thorough clinical and pharmacoepidemiologic investigations of the heterogenous side effect profiles for benzodiazepines and Z-drugs are needed. This may lead to more differentiated safety profiles and prescription practice for particular compounds, which in turn could potentially ease side effect burden in everyday clinical practice considerably. From both preclinical literature and pharmacovigilance data, there is converging evidence that this very large class of psychoactive molecules displays a broad range of distinctive unwanted effect profiles - too broad to be explained by the four canonical, so-called "diazepam-sensitive high-affinity interaction sites". The substance-specific signatures of compound effects may partly be mediated by phenomena such as occupancy of additional binding sites, and/or synergistic interactions with endogenous substances like steroids and endocannabinoids. These in turn drive the wanted and unwanted effects and sex differences of individual compounds.
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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
| | - Irena Dajić
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Thomas Seidel
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Markus Kunze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University Vienna, Vienna, Austria
| | - Matthäus Willeit
- Department of Psychiatry and Psychotherapy, Medical 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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Fagan HA, Baldwin DS. Pharmacological Treatment of Generalised Anxiety Disorder: Current Practice and Future Directions. Expert Rev Neurother 2023:1-14. [PMID: 37183813 DOI: 10.1080/14737175.2023.2211767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
INTRODUCTION Generalized Anxiety Disorder (GAD) is a common psychiatric condition, characterized by the presence of general apprehensiveness and excessive worry. Current management consists of a range of pharmacological and psychological treatments. However, many patients do not respond to first-line pharmacological treatments and novel anxiolytic drugs are being developed. AREAS COVERED In this review, the authors first discuss the diagnostic criteria and epidemiology of GAD. The effective pharmacological treatments for GAD and their tolerability are addressed. Current consensus guidelines for treatment of GAD are discussed, and maintenance treatment, the management of treatment resistance, and specific management of older adults and children/adolescents are considered. Finally, novel anxiolytics under development are discussed, with a focus on those which have entered clinical trials. EXPERT OPINION A range of effective treatments for GAD are available, particularly duloxetine, escitalopram, pregabalin, quetiapine, and venlafaxine. There is a limited evidence base to support the further pharmacological management of patients with GAD who have not responded to initial treatment. Although many novel anxiolytics have progressed to clinical trials, translation from animal models has been mostly unsuccessful. However, the potential of several compounds including certain psychedelics, ketamine, oxytocin, and agents modulating the orexin, endocannabinoid, and immune systems merits further study.
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Affiliation(s)
- Harry A Fagan
- Clinical and Experimental Sciences (CNS and Psychiatry), Faculty of Medicine, University of Southampton, Southampton, UK
- College Keep, Southern Health NHS Foundation Trust, Southampton, UK
| | - David S Baldwin
- Clinical and Experimental Sciences (CNS and Psychiatry), Faculty of Medicine, University of Southampton, Southampton, UK
- College Keep, Southern Health NHS Foundation Trust, Southampton, UK
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
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Voltage-clamp evidence of GABA A receptor subunit-specific effects: pharmacodynamic fingerprint of chlornordiazepam, the major active metabolite of mexazolam, as compared to alprazolam, bromazepam, and zolpidem. Pharmacol Rep 2022; 74:956-968. [PMID: 36097257 DOI: 10.1007/s43440-022-00411-x] [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: 06/09/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 10/14/2022]
Abstract
BACKGROUND Anxiolytic benzodiazepines, due to their clinical effectiveness, are one of the most prescribed drugs worldwide, despite being associated with sedative effects and impaired psychomotor and cognitive performance. Not every GABAA receptor functions in the same manner. Those containing α1 subunits are associated with sleep regulation and have a greater effect on the sedative-hypnotic benzodiazepines, whereas those containing α2 and/or α3 subunits are associated with anxiety phenomena and have a greater effect on the anxiolytic benzodiazepines. Therefore, characterization of the selectivity profile of anxiolytic drugs could translate into a significant clinical impact. METHODS The present study pharmacodynamically evaluated chlornordiazepam, the main active metabolite of mexazolam, upon GABAA receptors containing α2 and/or α3, anxiety-related, and those containing an α1 subunit, associated with sleep modulation. RESULTS As shown by whole-cell patch-clamp data, chlornordiazepam potentiated GABA-evoked current amplitude in α2 and α3 containing receptors without changing the current amplitude in α1 containing receptors. However, current decay time increased, particularly in GABAA receptors containing α1 subunits. In contrast, other anxiolytic benzodiazepines such as alprazolam, bromazepam, and zolpidem, all increased currents associated with GABAA receptors containing the α1 subunit. CONCLUSIONS This novel evidence demonstrates that mexazolam (through its main metabolite chlornordiazepam) has a "pharmacodynamic fingerprint" that correlates better with an anxiolytic profile and fewer sedative effects, when compared to alprazolam, bromazepam and zolpidem, explaining clinical trial outcomes with these drugs. This also highlights the relevance of the pharmacological selectivity over GABAA receptor subtypes in the selection of benzodiazepines, in addition to their clinical performance and pharmacokinetic characteristics.
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Microtubule-affinity regulating kinase 4: A potential drug target for cancer therapy. Cell Signal 2022; 99:110434. [PMID: 35961526 DOI: 10.1016/j.cellsig.2022.110434] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/14/2022] [Accepted: 08/05/2022] [Indexed: 12/29/2022]
Abstract
The human genome encodes more than 500 protein kinases that work by transferring the γ-phosphate group from ATP to serine, threonine, or tyrosine (Ser/Thr/Tyr) residues. Various kinases are associated with the onset of cancer and its further progression. The recent advancements in developing small-molecule kinase inhibitors to treat different cancer types have shown noticeable results in clinical therapies. Microtubule-affinity regulating kinase 4 (MARK-4) is a Ser/Thr protein kinase that relates structurally to AMPK/Snf1 subfamily of the CaMK kinases. The protein kinase modulates major signalling pathways such as NF-κB, mTOR and the Hippo-signalling pathway. MARK4 is associated with various cancer types due to its important role in regulating microtubule dynamics and subsequent cell division. Aberrant expression of MARK4 is linked with several pathologies such as cancer, Alzheimer's disease, obesity, etc. This review provides detailed information on structural aspects of MARK4 and its role in various signalling pathways related to cancer. Several therapeutic molecules were designed to inhibit the MARK4 activity from controlling associated diseases. The review further highlights kinase-targeted drug discovery and development in oncology and cancer therapies. Finally, we summarize the latest findings regarding the role of MARK4 in cancer, diabetes, and neurodegenerative disease path to provide a solid rationale for future investigation and therapeutic intervention.
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17
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Structural and dynamic mechanisms of GABA A receptor modulators with opposing activities. Nat Commun 2022; 13:4582. [PMID: 35933426 PMCID: PMC9357065 DOI: 10.1038/s41467-022-32212-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 07/21/2022] [Indexed: 12/02/2022] Open
Abstract
γ-Aminobutyric acid type A (GABAA) receptors are pentameric ligand-gated ion channels abundant in the central nervous system and are prolific drug targets for treating anxiety, sleep disorders and epilepsy. Diverse small molecules exert a spectrum of effects on γ-aminobutyric acid type A (GABAA) receptors by acting at the classical benzodiazepine site. They can potentiate the response to GABA, attenuate channel activity, or counteract modulation by other ligands. Structural mechanisms underlying the actions of these drugs are not fully understood. Here we present two high-resolution structures of GABAA receptors in complex with zolpidem, a positive allosteric modulator and heavily prescribed hypnotic, and DMCM, a negative allosteric modulator with convulsant and anxiogenic properties. These two drugs share the extracellular benzodiazepine site at the α/γ subunit interface and two transmembrane sites at β/α interfaces. Structural analyses reveal a basis for the subtype selectivity of zolpidem that underlies its clinical success. Molecular dynamics simulations provide insight into how DMCM switches from a negative to a positive modulator as a function of binding site occupancy. Together, these findings expand our understanding of how GABAA receptor allosteric modulators acting through a common site can have diverging activities. GABAA receptors are important targets for anxiety, sedation and anesthesia. Here, the authors present structures bound by zolpidem (Ambien), the most prescribed hypnotic in the US, and DMCM, a negative modulator, providing insights into receptor modulation.
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Cerne R, Lippa A, Poe MM, Smith JL, Jin X, Ping X, Golani LK, Cook JM, Witkin JM. GABAkines - Advances in the discovery, development, and commercialization of positive allosteric modulators of GABA A receptors. Pharmacol Ther 2022; 234:108035. [PMID: 34793859 PMCID: PMC9787737 DOI: 10.1016/j.pharmthera.2021.108035] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 11/08/2021] [Indexed: 12/25/2022]
Abstract
Positive allosteric modulators of γ-aminobutyric acid-A (GABAA) receptors or GABAkines have been widely used medicines for over 70 years for anxiety, epilepsy, sleep, and other disorders. Traditional GABAkines like diazepam have safety and tolerability concerns that include sedation, motor-impairment, respiratory depression, tolerance and dependence. Multiple GABAkines have entered clinical development but the issue of side-effects has not been fully solved. The compounds that are presently being developed and commercialized include several neuroactive steroids (an allopregnanolone formulation (brexanolone), an allopregnanolone prodrug (LYT-300), Sage-324, zuranolone, and ganaxolone), the α2/3-preferring GABAkine, KRM-II-81, and the α2/3/5-preferring GABAkine PF-06372865 (darigabat). The neuroactive steroids are in clinical development for post-partum depression, intractable epilepsy, tremor, status epilepticus, and genetic epilepsy disorders. Darigabat is in development for epilepsy and anxiety. The imidazodiazepine, KRM-II-81 is efficacious in animal models for the treatment of epilepsy and post-traumatic epilepsy, acute and chronic pain, as well as anxiety and depression. The efficacy of KRM-II-81 in models of pharmacoresistant epilepsy, preventing the development of seizure sensitization, and in brain tissue of intractable epileptic patients bodes well for improved therapeutics. Medicinal chemistry efforts are also ongoing to identify novel and improved GABAkines. The data document gaps in our understanding of the molecular pharmacology of GABAkines that drive differential pharmacological profiles, but emphasize advancements in the ability to successfully utilize GABAA receptor potentiation for therapeutic gain in neurology and psychiatry.
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Affiliation(s)
- Rok Cerne
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN USA,Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, Ljubljana, Slovenia.,RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA,Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, IN, USA
| | - Arnold Lippa
- RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA
| | | | - Jodi L. Smith
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN USA
| | - Xiaoming Jin
- Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, IN, USA
| | - Xingjie Ping
- Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, IN, USA
| | - Lalit K. Golani
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - James M. Cook
- RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA,Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Jeffrey M. Witkin
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN USA,RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA,Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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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: 3.3] [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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Can GABAkines Quiet the Noise? The GABAA Receptor Neurobiology and Pharmacology of Tinnitus. Biochem Pharmacol 2022; 201:115067. [DOI: 10.1016/j.bcp.2022.115067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/21/2022] [Accepted: 04/25/2022] [Indexed: 11/20/2022]
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The Case for Clinical Trials with Novel GABAergic Drugs in Diabetes Mellitus and Obesity. Life (Basel) 2022; 12:life12020322. [PMID: 35207609 PMCID: PMC8876029 DOI: 10.3390/life12020322] [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] [Received: 01/22/2022] [Revised: 02/09/2022] [Accepted: 02/16/2022] [Indexed: 11/17/2022] Open
Abstract
Obesity and diabetes mellitus have become the surprising menaces of relative economic well-being worldwide. Gamma amino butyric acid (GABA) has a prominent role in the control of blood glucose, energy homeostasis as well as food intake at several levels of regulation. The effects of GABA in the body are exerted through ionotropic GABAA and metabotropic GABAB receptors. This treatise will focus on the pharmacologic targeting of GABAA receptors to reap beneficial therapeutic effects in diabetes mellitus and obesity. A new crop of drugs selectively targeting GABAA receptors has been under investigation for efficacy in stroke recovery and cognitive deficits associated with schizophrenia. Although these trials have produced mixed outcomes the compounds are safe to use in humans. Preclinical evidence is summarized here to support the rationale of testing some of these compounds in diabetic patients receiving insulin in order to achieve better control of blood glucose levels and to combat the decline of cognitive performance. Potential therapeutic benefits could be achieved (i) By resetting the hypoglycemic counter-regulatory response; (ii) Through trophic actions on pancreatic islets, (iii) By the mobilization of antioxidant defence mechanisms in the brain. Furthermore, preclinical proof-of-concept work, as well as clinical trials that apply the novel GABAA compounds in eating disorders, e.g., olanzapine-induced weight-gain, also appear warranted.
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The imidazodiazepine, KRM-II-81: An example of a newly emerging generation of GABAkines for neurological and psychiatric disorders. Pharmacol Biochem Behav 2022; 213:173321. [PMID: 35041859 DOI: 10.1016/j.pbb.2021.173321] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 12/21/2021] [Accepted: 12/30/2021] [Indexed: 02/07/2023]
Abstract
GABAkines, or positive allosteric modulators of γ-aminobutyric acid-A (GABAA) receptors, are used for the treatment of anxiety, epilepsy, sleep, and other disorders. The search for improved GABAkines, with reduced safety liabilities (e.g., dependence) or side-effect profiles (e.g., sedation) constituted multiple discovery and development campaigns that involved a multitude of strategies over the past century. Due to the general lack of success in the development of new GABAkines, there had been a decades-long draught in bringing new GABAkines to market. Recently, however, there has been a resurgence of efforts to bring GABAkines to patients, the FDA approval of the neuroactive steroid brexanolone for post-partum depression in 2019 being the first. Other neuroactive steroids are in various stages of clinical development (ganaxolone, zuranolone, LYT-300, Sage-324, PRAX 114, and ETX-155). These GABAkines and non-steroid compounds (GRX-917, a TSPO binding site ligand), darigabat (CVL-865), an α2/3/5-preferring GABAkine, SAN711, an α3-preferring GABAkine, and the α2/3-preferring GABAkine, KRM-II-81, bring new therapeutic promise to this highly utilized medicinal target in neurology and psychiatry. Herein, we also discuss possible conditions that have enabled the transition to a new age of GABAkines. We highlight the pharmacology of KRM-II-81 that has the most preclinical data reported. KRM-II-81 is the lead compound in a new series of orally bioavailable imidazodiazepines entering IND-enabling safety studies. KRM-II-81 has a preclinical profile predicting efficacy against pharmacoresistant epilepsies, traumatic brain injury, and neuropathic pain. KRM-II-81 also produces anxiolytic- and antidepressant-like effects in rodent models. Other key features of the pharmacology of this compound are its low sedation rate, lack of tolerance development, and the ability to prevent the development of seizure sensitization.
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Zheng X, Wang C, Zhai N, Luo X, Liu G, Ju X. In Silico Screening of Novel α1-GABA A Receptor PAMs towards Schizophrenia Based on Combined Modeling Studies of Imidazo [1,2-a]-Pyridines. Int J Mol Sci 2021; 22:9645. [PMID: 34502550 PMCID: PMC8431797 DOI: 10.3390/ijms22179645] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/26/2021] [Accepted: 09/01/2021] [Indexed: 02/01/2023] Open
Abstract
The ionotropic GABAA receptor (GABAAR) has been proven to be an important target of atypical antipsychotics. A novel series of imidazo [1,2-a]-pyridine derivatives, as selective positive allosteric modulators (PAMs) of α1-containing GABAARs with potent antipsychotic activities, have been reported recently. To better clarify the pharmacological essentiality of these PAMs and explore novel antipsychotics hits, three-dimensional quantitative structure-activity relationships (3D-QSAR), molecular docking, pharmacophore modeling, and molecular dynamics (MD) were performed on 33 imidazo [1,2-a]-pyridines. The constructed 3D-QSAR models exhibited good predictive abilities. The dockings results and MD simulations demonstrated that hydrogen bonds, π-π stackings, and hydrophobic interactions play essential roles in the binding of these novel PAMs in the GABAAR binding pocket. Four hit compounds (DS01-04) were then screened out by the combination of the constructed models and computations, including the pharmacophore model, Topomer Search, molecular dockings, ADME/T predictions, and MD simulations. The compounds DS03 and DS04, with higher docking scores and better predicted activities, were also found to be relatively stable in the binding pocket by MD simulations. These results might provide a significant theoretical direction or information for the rational design and development of novel α1-GABAAR PAMs with antipsychotic activities.
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Affiliation(s)
- Xiaojiao Zheng
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China; (X.Z.); (C.W.); (N.Z.); (X.L.)
| | - Chenchen Wang
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China; (X.Z.); (C.W.); (N.Z.); (X.L.)
| | - Na Zhai
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China; (X.Z.); (C.W.); (N.Z.); (X.L.)
| | - Xiaogang Luo
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China; (X.Z.); (C.W.); (N.Z.); (X.L.)
- School of Materials Science and Engineering, Zhengzhou University, No. 100 Science Avenue, Zhengzhou 450001, 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, China; (X.Z.); (C.W.); (N.Z.); (X.L.)
| | - Xiulian Ju
- Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, China; (X.Z.); (C.W.); (N.Z.); (X.L.)
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Bleuer-Elsner S, Medam T, Masson S. Effects of a single oral dose of gabapentin on storm phobia in dogs: A double-blind, placebo-controlled crossover trial. THE VETERINARY RECORD 2021; 189:e453. [PMID: 33993491 DOI: 10.1002/vetr.453] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Storm phobia in companion dogs is a common disorder that significantly impacts dogs' welfare. Gabapentin, the action of which is only partially understood, is widely used for its antiepileptic and analgesic properties. Only recently, the veterinary community began to use gabapentin to address phobia and anxiety in dogs. This study tested gabapentin to lower fear responses of dogs during a thunderstorm event. METHODS Eighteen dogs suffering from storm phobia completed our double-blind, placebo-controlled crossover trial. Each dog's behaviour was evaluated twice by his owner: once under placebo, once under gabapentin. The treatment was orally administered at least 90 min before the exposure. Gabapentin was given at a dose ranging from 25 to 30 mg/kg. RESULTS Our results indicate a significant reduction of the fear responses of dogs under gabapentin. The adverse effects were rare, and the most frequent amongst them was ataxia. CONCLUSION In this trial, gabapentin appears to be an efficient and safe molecule that should be considered as part of the treatment plan of storm phobia in dogs.
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Abstract
Treatment of a N-2-pyridyl-β-ketoamide precursor with bromine afforded the first example of the 3-aryl(α-hydroxy)methylenelimidazo[1,2-a]pyridin-2(3H)-one framework. This transformation proceeded through a domino process comprising an initial bromination, cyclization via an intramolecular SN reaction, and a final keto-enol tautomerism, and allows generation of the fused heterocyclic system and installation of the acyl substituent in a single operation.
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Sanabria E, Cuenca RE, Esteso MÁ, Maldonado M. Benzodiazepines: Their Use either as Essential Medicines or as Toxics Substances. TOXICS 2021; 9:25. [PMID: 33535485 PMCID: PMC7912725 DOI: 10.3390/toxics9020025] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 01/19/2021] [Indexed: 11/16/2022]
Abstract
This review highlights the nature, characteristics, properties, pharmacological differences between different types of benzodiazepines, the mechanism of action in the central nervous system, and the degradation of benzodiazepines. In the end, the efforts to reduce the benzodiazepines' adverse effects are shown and a reflection is made on the responsible uses of these medications.
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Affiliation(s)
- Edilma Sanabria
- Grupo GICRIM, Programa de Investigación Criminal, Universidad Manuela Beltrán, Avenida Circunvalar No. 60-00, 111321 Bogotá, Colombia; (E.S.); (R.E.C.)
| | - Ronald Edgardo Cuenca
- Grupo GICRIM, Programa de Investigación Criminal, Universidad Manuela Beltrán, Avenida Circunvalar No. 60-00, 111321 Bogotá, Colombia; (E.S.); (R.E.C.)
| | - Miguel Ángel Esteso
- Universidad Católica Santa Teresa de Jesús de Ávila, Calle los Canteros s/n, 05005 Ávila, Spain;
- U.D. Química Física, Universidad de Alcalá, 28805 Alcalá de Henares, Spain
| | - Mauricio Maldonado
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia, Sede Bogotá, Cr. 30 No. 45-03, 111321 Bogotá, Colombia
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Perdew I, Emke C, Johnson B, Dixit V, Song Y, Griffith EH, Watson P, Gruen ME. Evaluation of Pexion ® (imepitoin) for treatment of storm anxiety in dogs: A randomised, double-blind, placebo-controlled trial. Vet Rec 2021; 188:e18. [PMID: 33960445 DOI: 10.1002/vetr.18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/07/2020] [Accepted: 12/03/2020] [Indexed: 11/10/2022]
Abstract
BACKGROUND While often grouped with other noise aversions, fearful behaviour during storms is considered more complex than noise aversion alone. The objective here was to assess the effect of imepitoin for the treatment of storm anxiety in dogs. METHODS In this double-blind, placebo-controlled randomised study, eligible dogs completed a baseline then were randomised to receive either imepitoin (n = 30; 30 mg/kg BID) or placebo (n = 15) for 28 days. During storms, owners rated their dog's intensity for 16 behaviours using a Likert scale. Weekly, owners rated intensity and frequency of these behaviours. Summary scores were compared to baseline and between groups. RESULTS AND CONCLUSIONS Imepitoin was significantly superior to placebo in storm logs and weekly surveys for weeks 2 and 4, and in the end-of-study survey. Mild/moderate adverse events were reported in 26 patients (24 active: two placebo); the most frequent adverse event was ataxia. Owners of dogs in the imepitoin group, compared to placebo, were significantly more likely to report that treatment reduced their dogs fear and anxiety during storms (p < 0.001) and other noise events (p < 0.001). Twice daily administration of imepitoin decreased anxiety scores in dogs with storm anxiety. Future work may evaluate optimal dosage regimens.
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Affiliation(s)
- Irina Perdew
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina, USA
| | - Carrie Emke
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina, USA
| | - Brianna Johnson
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina, USA
| | - Vaidehi Dixit
- Department of Statistics, North Carolina State University College of Sciences, Raleigh, North Carolina, USA
| | - Yukun Song
- Department of Statistics, North Carolina State University College of Sciences, Raleigh, North Carolina, USA
| | - Emily H Griffith
- Department of Statistics, North Carolina State University College of Sciences, Raleigh, North Carolina, USA
| | - Philip Watson
- Ingelheim am Rhein, Boehringer-Ingelheim Vetmedica GmbH, Ludwigshafen am Rhein, Germany
| | - Margaret E Gruen
- Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina, USA
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28
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Fabjan J, Koniuszewski F, Schaar B, Ernst M. Structure-Guided Computational Methods Predict Multiple Distinct Binding Modes for Pyrazoloquinolinones in GABA A Receptors. Front Neurosci 2021; 14:611953. [PMID: 33519364 PMCID: PMC7844064 DOI: 10.3389/fnins.2020.611953] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/23/2020] [Indexed: 12/16/2022] Open
Abstract
Pyrazoloquinolinones (PQs) are a versatile class of GABAA receptor ligands. It has been demonstrated that high functional selectivity for certain receptor subtypes can be obtained by specific substitution patterns, but so far, no clear SAR rules emerge from the studies. As is the case for many GABAA receptor targeting chemotypes, PQs can interact with distinct binding sites on a given receptor pentamer. In pentamers of αβγ composition, such as the most abundant α1β2γ2 subtype, many PQs are high affinity binders of the benzodiazepine binding site at the extracellular α+/γ2- interfaces. There they display a functionally near silent, flumazenil-like allosteric activity. More recently, interactions with extracellular α+/β- interfaces have been investigated, where strong positive modulation can be steered toward interesting subtype preferences. The most prominent examples are functionally α6-selective PQs. Similar to benzodiazepines, PQs also seem to interact with sites in the transmembrane domain, mainly the sites used by etomidate and barbiturates. This promiscuity leads to potential contributions from multiple sites to net modulation. Developing ligands that interact exclusively with the extracellular α+/β- interfaces would be desired. Correlating functional profiles with binding sites usage is hampered by scarce and heterogeneous experimental data, as shown in our meta-analysis of aggregated published data. In the absence of experimental structures, bound states can be predicted with pharmacophore matching methods and with computational docking. We thus performed pharmacophore matching studies for the unwanted sites, and computational docking for the extracellular α1,6+/β3- interfaces. The results suggest that PQs interact with their binding sites with diverse binding modes. As such, rational design of improved ligands needs to take a complex structure-activity landscape with branches between sub-series of derivatives into account. We present a workflow, which is suitable to identify and explore potential branching points on the structure-activity landscape of any small molecule chemotype.
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Affiliation(s)
| | | | | | - Margot Ernst
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
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29
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Löscher W, Klein P. The Pharmacology and Clinical Efficacy of Antiseizure Medications: From Bromide Salts to Cenobamate and Beyond. CNS Drugs 2021; 35:935-963. [PMID: 34145528 PMCID: PMC8408078 DOI: 10.1007/s40263-021-00827-8] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/04/2021] [Indexed: 12/16/2022]
Abstract
Epilepsy is one of the most common and disabling chronic neurological disorders. Antiseizure medications (ASMs), previously referred to as anticonvulsant or antiepileptic drugs, are the mainstay of symptomatic epilepsy treatment. Epilepsy is a multifaceted complex disease and so is its treatment. Currently, about 30 ASMs are available for epilepsy therapy. Furthermore, several ASMs are approved therapies in nonepileptic conditions, including neuropathic pain, migraine, bipolar disorder, and generalized anxiety disorder. Because of this wide spectrum of therapeutic activity, ASMs are among the most often prescribed centrally active agents. Most ASMs act by modulation of voltage-gated ion channels; by enhancement of gamma aminobutyric acid-mediated inhibition; through interactions with elements of the synaptic release machinery; by blockade of ionotropic glutamate receptors; or by combinations of these mechanisms. Because of differences in their mechanisms of action, most ASMs do not suppress all types of seizures, so appropriate treatment choices are important. The goal of epilepsy therapy is the complete elimination of seizures; however, this is not achievable in about one-third of patients. Both in vivo and in vitro models of seizures and epilepsy are used to discover ASMs that are more effective in patients with continued drug-resistant seizures. Furthermore, therapies that are specific to epilepsy etiology are being developed. Currently, ~ 30 new compounds with diverse antiseizure mechanisms are in the preclinical or clinical drug development pipeline. Moreover, therapies with potential antiepileptogenic or disease-modifying effects are in preclinical and clinical development. Overall, the world of epilepsy therapy development is changing and evolving in many exciting and important ways. However, while new epilepsy therapies are developed, knowledge of the pharmacokinetics, antiseizure efficacy and spectrum, and adverse effect profiles of currently used ASMs is an essential component of treating epilepsy successfully and maintaining a high quality of life for every patient, particularly those receiving polypharmacy for drug-resistant seizures.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Bünteweg 17, 30559, Hannover, Germany. .,Center for Systems Neuroscience, Hannover, Germany.
| | - Pavel Klein
- grid.429576.bMid-Atlantic Epilepsy and Sleep Center, Bethesda, MD USA
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30
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Crocetti L, Guerrini G. GABA A receptor subtype modulators in medicinal chemistry: an updated patent review (2014-present). Expert Opin Ther Pat 2020; 30:409-432. [PMID: 32200689 DOI: 10.1080/13543776.2020.1746764] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Introduction: Ligands at the benzodiazepine binding site of the GABAA receptor (GABAAR) act by modulating the effect of GABA (γ-aminobutyric acid). The benzodiazepine drugs are conventionally categorized as positive allosteric modulators enhancing the chloride ion current GABA-induced. In literature there are also reported ligands that act as negative allosteric modulators, reducing chloride ion current, and silent allosteric modulators not influencing the chloride ion flux.Areas covered: This review covers patents published from 2014 to present on ligands for the benzodiazepine binding site of the GABAARs. Patents filed from different companies and research groups report many compounds that may be used in the treatment/prevention of a large variety of diseases.Expert opinion: Since the discovery of the first benzodiazepine about 60 years have passed and about 50 years since the identification of their target, GABAA receptor. Even if benzodiazepines are the most popular anxiolytic drugs, the research in this field is still very active. From patents/application analysis arises that most of them claim methods for alleviating specific symptoms in different neurodegenerative diseases and their related memory deficits. Noteworthy is the presence of the α4- and α5-GABAA receptor subtype ligands as new pharmacological tools for airway hyperresponsiveness, inflammation diseases, and asthma.
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Affiliation(s)
- Letizia Crocetti
- NEUROFARBA, Pharmaceutical and Nutraceutical Section, University of Florence, Sesto Fiorentino, Italy
| | - Gabriella Guerrini
- NEUROFARBA, Pharmaceutical and Nutraceutical Section, University of Florence, Sesto Fiorentino, Italy
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31
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Duke AN, Platt DM, Rowlett JK. Tolerance and dependence following chronic alprazolam treatment: quantitative observation studies in female rhesus monkeys. Psychopharmacology (Berl) 2020; 237:1183-1194. [PMID: 31927603 PMCID: PMC7988478 DOI: 10.1007/s00213-019-05447-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 12/27/2019] [Indexed: 11/28/2022]
Abstract
RATIONALE In order to understand mechanisms underlying tolerance and dependence following chronic benzodiazepine treatments, quantitative and reproducible behavioral models of these phenomena are required. OBJECTIVES This research evaluated the ability of chronic treatment with a commonly prescribed benzodiazepine, alprazolam, to induce tolerance to sedative effects and physical dependence using a novel set of behavioral measurements in rhesus monkeys. METHODS Four female rhesus monkeys (Macaca mulatta) were implanted with chronic intravenous catheters and administered i.v. alprazolam (1.0 mg/kg every 4 h, 38 days total). Quantitative observation measures were obtained during the 38 days of treatment. Acute administration of the benzodiazepine receptor antagonist flumazenil (0.1, 0.3 mg/kg, i.v.) was given to assess precipitated withdrawal. On day 39, saline was substituted for alprazolam and withdrawal signs were assessed for 7 days. RESULTS Maximal sedation ("deep sedation") was evident on day 1 but was not significantly different from baseline levels by day 4 and was absent for the remainder of the 38 days of treatment. A milder form of sedation, "rest/sleep posture," emerged by day 3 and did not decline over 38 days. Cessation of alprazolam treatment resulted in significant withdrawal signs (nose rub, vomit, procumbent posture, tremor/jerk, rigid posture) that dissipated by day 3. These signs also were observed with flumazenil (0.3 mg/kg). CONCLUSIONS Chronic alprazolam treatment resulted in rapid tolerance to some behaviors (e.g., deep sedation) but no tolerance to others (e.g., rest/sleep posture). Physical dependence was observed via both spontaneous and precipitated withdrawal. Based on previous research, these phenomena may reflect differential plasticity at GABAA receptor subtypes.
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Affiliation(s)
- Angela N Duke
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
- New England Primate Research Center, Harvard Medical School, One Pine Hill Drive, Southborough, MA, 01772, USA
- Wake Forest Baptist Medical Center, Winston-Salem, NC, USA
| | - Donna M Platt
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
- New England Primate Research Center, Harvard Medical School, One Pine Hill Drive, Southborough, MA, 01772, USA
| | - James K Rowlett
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.
- New England Primate Research Center, Harvard Medical School, One Pine Hill Drive, Southborough, MA, 01772, USA.
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32
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Vega Alanis BA, Iorio MT, Silva LL, Bampali K, Ernst M, Schnürch M, Mihovilovic MD. Allosteric GABA A Receptor Modulators-A Review on the Most Recent Heterocyclic Chemotypes and Their Synthetic Accessibility. Molecules 2020; 25:E999. [PMID: 32102309 PMCID: PMC7070463 DOI: 10.3390/molecules25040999] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 11/17/2022] Open
Abstract
GABAA receptor modulators are structurally almost as diverse as their target protein. A plethora of heterocyclic scaffolds has been described as modulating this extremely important receptor family. Some made it into clinical trials and, even on the market, some were dismissed. This review focuses on the synthetic accessibility and potential for library synthesis of GABAA receptor modulators containing at least one heterocyclic scaffold, which were disclosed within the last 10 years.
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Affiliation(s)
- Blanca Angelica Vega Alanis
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/193, 1060 Vienna, Austria; (B.A.V.A.); (M.T.I.); (M.D.M.)
| | - Maria Teresa Iorio
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/193, 1060 Vienna, Austria; (B.A.V.A.); (M.T.I.); (M.D.M.)
| | - Luca L. Silva
- Department of Anesthesiology and Intensive Care Medicine, Charité–Universitätsmedizin, Charitéplatz 1, 10117 Berlin, Germany;
| | - Konstantina Bampali
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria;
| | - Margot Ernst
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria;
| | - Michael Schnürch
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/193, 1060 Vienna, Austria; (B.A.V.A.); (M.T.I.); (M.D.M.)
| | - Marko D. Mihovilovic
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/193, 1060 Vienna, Austria; (B.A.V.A.); (M.T.I.); (M.D.M.)
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Maramai S, Benchekroun M, Ward SE, Atack JR. Subtype Selective γ-Aminobutyric Acid Type A Receptor (GABAAR) Modulators Acting at the Benzodiazepine Binding Site: An Update. J Med Chem 2019; 63:3425-3446. [DOI: 10.1021/acs.jmedchem.9b01312] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Samuele Maramai
- Sussex Drug Discovery Centre, University of Sussex, Brighton BN1 9QJ, U.K
| | - Mohamed Benchekroun
- Sussex Drug Discovery Centre, University of Sussex, Brighton BN1 9QJ, U.K
- Équipe de Chimie Moléculaire, Laboratoire de Génomique Bioinformatique et Chimie Moléculaire, GBCM, EA7528, Conservatoire National des Arts et Métiers, 2 rue Conté, 75003 Paris, France
| | - Simon E. Ward
- Medicines Discovery Institute, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
| | - John R. Atack
- Medicines Discovery Institute, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K
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Tikhonova TA, Rassokhina IV, Kondrakhin EA, Fedosov MA, Bukanova JV, Rossokhin AV, Sharonova IN, Kovalev GI, Zavarzin IV, Volkova YA. Development of 1,3-thiazole analogues of imidazopyridines as potent positive allosteric modulators of GABA A receptors. Bioorg Chem 2019; 94:103334. [PMID: 31711764 DOI: 10.1016/j.bioorg.2019.103334] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 09/17/2019] [Accepted: 09/30/2019] [Indexed: 12/14/2022]
Abstract
Structure-activity relationship studies were conducted in the search for 1,3-thiazole isosteric analogs of imidazopyridine drugs (Zolpidem, Alpidem). Three series of novel γ-aminobutyric acid receptor (GABAAR) ligands belonging to imidazo[2,1-b]thiazoles, imidazo[2,1-b][1,3,4]thiadiazoles, and benzo[d]imidazo[2,1-b]thiazoles were synthesized and characterized as active agents against GABAAR benzodiazepine-binding site. In each of these series, potent compounds were discovered using a radioligand competition binding assay. The functional properties of highest-affinity compounds 28 and 37 as GABAAR positive allosteric modulators (PAMs) were determined by electrophysiological measurements. In vivo studies on zebrafish demonstrated their potential for the further development of anxiolytics. Using the OECD "Fish, Acute Toxicity Test" active compounds were found safe and non-toxic. Structural bases for activity of benzo[d]imidazo[2,1-b]thiazoles were proposed using molecular docking studies. The isosteric replacement of the pyridine nuclei by 1,3-thiazole, 1,3,4-thiadiazole, or 1,3-benzothiazole in the ring-fused imidazole class of GABAAR PAMs was shown to be promising for the development of novel hypnotics, anxiolytics, anticonvulsants, and sedatives drug-candidates.
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Affiliation(s)
- Tatyana A Tikhonova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russia
| | - Irina V Rassokhina
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russia
| | - Eugeny A Kondrakhin
- V. V. Zakusov Institute of Pharmacology, Russian Academy of Sciences, 8 Baltiyskaya Str., 125315 Moscow, Russia
| | - Mikhail A Fedosov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russia
| | - Julia V Bukanova
- Research Center of Neurology, 5 By-str. Obukha, 105064 Moscow, Russia
| | | | - Irina N Sharonova
- Research Center of Neurology, 5 By-str. Obukha, 105064 Moscow, Russia
| | - Georgy I Kovalev
- V. V. Zakusov Institute of Pharmacology, Russian Academy of Sciences, 8 Baltiyskaya Str., 125315 Moscow, Russia
| | - Igor V Zavarzin
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russia
| | - Yulia A Volkova
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russia.
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35
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Engel O, Müller HW, Klee R, Francke B, Mills DS. Effectiveness of imepitoin for the control of anxiety and fear associated with noise phobia in dogs. J Vet Intern Med 2019; 33:2675-2684. [PMID: 31568622 PMCID: PMC6872611 DOI: 10.1111/jvim.15608] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 08/20/2019] [Indexed: 11/30/2022] Open
Abstract
Background Noise phobia is a common behavior problem in dogs for which there are limited treatment options. Objective To evaluate the efficacy and safety of imepitoin in comparison to placebo for the control of anxiety and fear associated with noise phobia in dogs. Animals Two hundred thirty‐eight client‐owned dogs with noise phobia were recruited in veterinary clinics. Methods This placebo‐controlled, randomized, double‐blinded, clinical trial used a predictable noise event as eliciting context, the traditional New Year's Eve fireworks in Germany and the Netherlands. Owners began treatment 2 days before the anticipated noise event with administration of either imepitoin 30 mg/kg body weight Q12h or placebo for 3 consecutive days. On New Year's Eve, owners noted their observations of their dog's fear and anxiety behavior at 1600, 2200, 0020, and 0100 hours and scored the overall treatment effect on the following day. Results In the 16‐item owner report of fear and anxiety signs, fear and anxiety behaviors were significantly reduced under imepitoin treatment compared to placebo (delta −6.1 scoring points; P < .0001). A significantly higher proportion of owners reported a good or excellent overall treatment effect in the imepitoin group compared to placebo (odds ratio 4.689; 95% CI, 2.79‐7.89; P < .0001). Conclusion Imepitoin effectively controls fear and anxiety associated with noise phobia in dogs.
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Affiliation(s)
- Odilo Engel
- Boehringer Ingelheim Vetmedica GmbH, Ingelheim am Rhein, Germany
| | | | - Rebecca Klee
- Boehringer Ingelheim Vetmedica GmbH, Ingelheim am Rhein, Germany
| | - Bradley Francke
- Boehringer Ingelheim Vetmedica GmbH, Ingelheim am Rhein, Germany
| | - Daniel Simon Mills
- Animal Behaviour Cognition and Welfare Group, School of Life Sciences, University of Lincoln, Lincoln, United Kingdom
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36
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Synthesis of New GABA A Receptor Modulator with Pyrazolo[1,5-a]quinazoline (PQ) Scaffold. Int J Mol Sci 2019; 20:ijms20061438. [PMID: 30901916 PMCID: PMC6470557 DOI: 10.3390/ijms20061438] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 03/11/2019] [Accepted: 03/14/2019] [Indexed: 12/17/2022] Open
Abstract
We previously published a series of 8-methoxypirazolo[1,5-a]quinazolines (PQs) and their 4,5-dihydro derivatives (4,5(H)PQ) bearing the (hetero)arylalkylester group at position 3 as ligands at the γ-aminobutyric type A (GABAA) subtype receptor. Continuing the study in this field, we report here the design and synthesis of 3-(hetero)arylpyrazolo[1,5-a]quinazoline and 3-(hetero)aroylpyrazolo[1,5-a]quinazoline 8-methoxy substituted as interesting analogs of the above (hetero)arylalkylester, in which the shortening or the removal of the linker between the 3-(hetero)aryl ring and the PQ was performed. Only compounds that are able to inhibit radioligand binding by more than 80% at 10 μM have been selected for electrophysiological studies on recombinant α1β2γ2L GABAA receptors. Some compounds show a promising profile. For example, compounds 6a and 6b are able to modulate the GABAAR in an opposite manner, since 6b enhances and 6a reduces the variation of the chlorine current, suggesting that they act as a partial agonist and an inverse partial agonist, respectively. The most potent derivative was 3-(4-methoxyphenylcarbonyl)-8-methoxy-4,5-dihydropyrazolo[1,5-a] quinazoline 11d, which reaches a maximal activity at 1 μM (+54%), and it enhances the chlorine current at ≥0.01 μM. Finally, compound 6g, acting as a null modulator at α1β2γ2L, shows the ability to antagonize the full agonist diazepam and the potentiation of CGS 9895 on the new α+/β− ‘non-traditional’ benzodiazepine site.
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37
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Engel O, Masic A, Landsberg G, Brooks M, Mills DS, Rundfeldt C. Imepitoin Shows Benzodiazepine-Like Effects in Models of Anxiety. Front Pharmacol 2018; 9:1225. [PMID: 30455643 PMCID: PMC6230983 DOI: 10.3389/fphar.2018.01225] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 10/08/2018] [Indexed: 01/21/2023] Open
Abstract
Imepitoin is a low affinity partial agonist for the benzodiazepine binding site of γ-aminobutyric acid (GABAA) receptors, and is currently used as an antiepileptic in dogs. Here we tested imepitoin for anxiolytic properties. In an in vitro model, imepitoin was capable of preventing the effect of corticotrophin releasing factor (CRF) on locus coeruleus neurons without suppressing the basal activity of these cells, an activity which is suggestive for an anti-stress effect of imepitoin. In addition, we applied a battery of standard rodent preclinical tests for anxiety behavior including elevated plus mazes in mice and rats, light-dark-box in mice and rats, social interaction test in rats, or the Vogel conflict test in rats. In all models, the observed profile of imepitoin appeared similar to benzodiazepines and typical for anxiolytic drugs. We also observed anxiolytic activity in dogs in a provoked open field sound-induced fear model, where reactions to noises were elicited by a sound recording of thunderstorms. Imepitoin caused an increase in locomotion measured in distance traveled and an ameliorating effect on cortisol levels in response to thunderstorm noises. For comparison, dexmedetomidine caused a decrease in locomotion and had no effect on cortisol. In all animal models the doses needed for an anxiolytic effect were not associated with sedation. In rodents, there was at least a factor of 10 between anxiolytic doses and doses with mild signs of sedation. In summary, imepitoin showed similar anxiolytic activities as benzodiazepines but without producing the known adverse reactions of benzodiazepines such as sedation.
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Affiliation(s)
- Odilo Engel
- Boehringer Ingelheim Vetmedica GmbH, Ingelheim am Rhein, Germany
| | | | | | | | - Daniel S. Mills
- Animal Behaviour, Cognition and Welfare Group, School of Life Sciences, University of Lincoln, Lincoln, United Kingdom
| | - Chris Rundfeldt
- Drug Consulting Network, Coswig, Germany
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Hanover, Germany
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Sieghart W, Savić MM. International Union of Basic and Clinical Pharmacology. CVI: GABAA Receptor Subtype- and Function-selective Ligands: Key Issues in Translation to Humans. Pharmacol Rev 2018; 70:836-878. [DOI: 10.1124/pr.117.014449] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Siebert DCB, Wieder M, Schlener L, Scholze P, Boresch S, Langer T, Schnürch M, Mihovilovic MD, Richter L, Ernst M, Ecker GF. SAR-Guided Scoring Function and Mutational Validation Reveal the Binding Mode of CGS-8216 at the α1+/γ2- Benzodiazepine Site. J Chem Inf Model 2018; 58:1682-1696. [PMID: 30028134 DOI: 10.1021/acs.jcim.8b00199] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The structural resolution of a bound ligand-receptor complex is a key asset to efficiently drive lead optimization in drug design. However, structural resolution of many drug targets still remains a challenging endeavor. In the absence of structural knowledge, scientists resort to structure-activity relationships (SARs) to promote compound development. In this study, we incorporated ligand-based knowledge to formulate a docking scoring function that evaluates binding poses for their agreement with a known SAR. We showcased this protocol by identifying the binding mode of the pyrazoloquinolinone (PQ) CGS-8216 at the benzodiazepine binding site of the GABAA receptor. Further evaluation of the final pose by molecular dynamics and free energy simulations revealed a close proximity between the pendent phenyl ring of the PQ and γ2D56, congruent with the low potency of carboxyphenyl analogues. Ultimately, we introduced the γ2D56A mutation and in fact observed a 10-fold potency increase in the carboxyphenyl analogue, providing experimental evidence in favor of our binding hypothesis.
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Affiliation(s)
- David C B Siebert
- Institute of Applied Synthetic Chemistry , TU Wien , Getreidemarkt 9/163 , 1060 Vienna , Austria
| | - Marcus Wieder
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstrasse 14 , 1090 Vienna , Austria.,Faculty of Chemistry, Department of Computational Biological Chemistry , University of Vienna , Währingerstrasse 17 , 1090 Vienna , Austria
| | - Lydia Schlener
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstrasse 14 , 1090 Vienna , Austria
| | - Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research , Medical University of Vienna , Spitalgasse 4 , 1090 Vienna , Austria
| | - Stefan Boresch
- Faculty of Chemistry, Department of Computational Biological Chemistry , University of Vienna , Währingerstrasse 17 , 1090 Vienna , Austria
| | - Thierry Langer
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstrasse 14 , 1090 Vienna , Austria
| | - Michael Schnürch
- Institute of Applied Synthetic Chemistry , TU Wien , Getreidemarkt 9/163 , 1060 Vienna , Austria
| | - Marko D Mihovilovic
- Institute of Applied Synthetic Chemistry , TU Wien , Getreidemarkt 9/163 , 1060 Vienna , Austria
| | - Lars Richter
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstrasse 14 , 1090 Vienna , Austria
| | - Margot Ernst
- Department of Molecular Neurosciences, Center for Brain Research , Medical University of Vienna , Spitalgasse 4 , 1090 Vienna , Austria
| | - Gerhard F Ecker
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstrasse 14 , 1090 Vienna , Austria
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Batinić B, Stanković T, Stephen MR, Kodali R, Tiruveedhula VV, Li G, Scholze P, Marković BD, Obradović AL, Ernst M, Cook JM, Savić MM. Attaining in vivo selectivity of positive modulation of α3βγ2 GABA A receptors in rats: A hard task! Eur Neuropsychopharmacol 2018; 28:903-914. [PMID: 29891214 DOI: 10.1016/j.euroneuro.2018.05.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 04/10/2018] [Accepted: 05/21/2018] [Indexed: 12/22/2022]
Abstract
It is unclear whether GABAA receptors (GABAARs) that contain the α3-subunit are substantially involved in the anxiolytic effects of benzodiazepines (BDZs). In the present study, we tested YT-III-31, a newer BDZ ligand with functional preference for α3βγ2 GABAARs, in two paradigms of unconditioned anxiety, the open field and elevated plus maze in rats. The effective dose of YT-III-31 (2 mg/kg) displayed a clear anxiolytic-like profile, unhampered by sedative action, in both tests. At a higher dose (10 mg/kg), YT-III-31 induced ataxia in the rotarod and sedation in spontaneous locomotor activity test. The latter effect was preventable by flumazenil and βCCt, the non-selective and α1βγ2 GABAAR affinity-selective antagonist, respectively, demonstrating that sedative properties of YT-III-31, when attained, are mediated by the α1γ2 site. To elucidate the receptor substrate of subtle behavioral differences between YT-III-31 and diazepam, we approximated in vivo receptor potentiation for both ligands, based on estimated unbound concentrations in rat brains. Far different from diazepam, YT-III-31 has significantly lower affinity for the α1γ2 over other BDZ-sensitive sites, and at lower doses (1-2 mg/kg) was devoid of potentiation at α1βγ2 GABAARs. The approximation approach revealed a modest selectivity of YT-III-31 for α3γ2- in comparison to α2γ2 and α5γ2 binding sites, suggesting that its anxiolytic-like activity may not necessarily or predominantly reflect potentiation at α3βγ2 GABAARs. Nonetheless, as the anxiolytic effects are achievable at a dose devoid of any sedative potential, and having favorable safety (cytotoxicity) and metabolic stability profile, YT-III-31 represents a valuable candidate for further translational research.
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Affiliation(s)
- Bojan Batinić
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Tamara Stanković
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Michael Rajesh Stephen
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Revathi Kodali
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Veera V Tiruveedhula
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Guanguan Li
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Bojan D Marković
- Department of Pharmaceutical Pharmacy, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Aleksandar Lj Obradović
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Margot Ernst
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - James M Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA
| | - Miroslav M Savić
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11221 Belgrade, Serbia.
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Witkin J, Smith J, Ping X, Gleason S, Poe M, Li G, Jin X, Hobbs J, Schkeryantz J, McDermott J, Alatorre A, Siemian J, Cramer J, Airey D, Methuku K, Tiruveedhula V, Jones T, Crawford J, Krambis M, Fisher J, Cook J, Cerne R. Bioisosteres of ethyl 8-ethynyl-6-(pyridin-2-yl)-4H-benzo[f]imidazo [1,5-a][1,4]diazepine-3-carboxylate (HZ-166) as novel alpha 2,3 selective potentiators of GABAA receptors: Improved bioavailability enhances anticonvulsant efficacy. Neuropharmacology 2018; 137:332-343. [DOI: 10.1016/j.neuropharm.2018.05.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 04/29/2018] [Accepted: 05/03/2018] [Indexed: 10/17/2022]
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The Benzodiazepine Binding Sites of GABAA Receptors. Trends Pharmacol Sci 2018; 39:659-671. [DOI: 10.1016/j.tips.2018.03.006] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/15/2018] [Accepted: 03/22/2018] [Indexed: 11/24/2022]
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Duke AN, Meng Z, Platt DM, Atack JR, Dawson GR, Reynolds DS, Tiruveedhula VVNPB, Li G, Stephen MR, Sieghart W, Cook JM, Rowlett JK. Evidence That Sedative Effects of Benzodiazepines Involve Unexpected GABA A Receptor Subtypes: Quantitative Observation Studies in Rhesus Monkeys. J Pharmacol Exp Ther 2018; 366:145-157. [PMID: 29720564 PMCID: PMC5988000 DOI: 10.1124/jpet.118.249250] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 04/30/2018] [Indexed: 11/22/2022] Open
Abstract
In nonhuman primates we tested a new set of behavioral categories for observable sedative effects using pediatric anesthesiology classifications as a basis. Using quantitative behavioral observation techniques in rhesus monkeys, we examined the effects of alprazolam and diazepam (nonselective benzodiazepines), zolpidem (preferential binding to α1 subunit-containing GABAA receptors), HZ-166 (8-ethynyl-6-(2'-pyridine)-4H-2,5,10b-triaza-benzo[e]azulene-3-carboxylic acid ethyl ester; functionally selective with relatively high intrinsic efficacy for α2 and α3 subunit-containing GABAA receptors), MRK-696 [7-cyclobutyl-6-(2-methyl-2H-1,2,4-triazol-2-ylmethoxy)-3-(2-flurophenyl)-1,2,4-triazolo(4,3-b)pyridazine; no selectivity but partial intrinsic activity], and TPA023B 6,2'-diflouro-5'-[3-(1-hydroxy-1-methylethyl)imidazo[1,2-b][1,2,4]triazin-7-yl]biphenyl-2-carbonitrile; partial intrinsic efficacy and selectivity for α2, α3, α5 subunit-containing GABAA receptors]. We further examined the role of α1 subunit-containing GABAA receptors in benzodiazepine-induced sedative effects by pretreating animals with the α1 subunit-preferring antagonist β-carboline-3-carboxylate-t-butyl ester (βCCT). Increasing doses of alprazolam and diazepam resulted in the emergence of observable ataxia, rest/sleep posture, and moderate and deep sedation. In contrast, zolpidem engendered dose-dependent observable ataxia and deep sedation but not rest/sleep posture or moderate sedation, and HZ-166 and TPA023 induced primarily rest/sleep posture. MRK-696 induced rest/sleep posture and observable ataxia. Zolpidem, but no other compounds, significantly increased tactile/oral exploration. The sedative effects engendered by alprazolam, diazepam, and zolpidem generally were attenuated by βCCT pretreatments, whereas rest/sleep posture and suppression of tactile/oral exploration were insensitive to βCCT administration. These data suggest that α2/3-containing GABAA receptor subtypes unexpectedly may mediate a mild form of sedation (rest/sleep posture), whereas α1-containing GABAA receptors may play a role in moderate/deep sedation.
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Affiliation(s)
- Angela N Duke
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - Zhiqiang Meng
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - Donna M Platt
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - John R Atack
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - Gerard R Dawson
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - David S Reynolds
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - V V N Phani Babu Tiruveedhula
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - Guanguan Li
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - Michael Rajesh Stephen
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - Werner Sieghart
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - James M Cook
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
| | - James K Rowlett
- New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts (A.N.D., Z.M., D.M.P., J.K.R.); Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi (D.M.P., J.K.R.); Medicines Discovery Institute, Cardiff University, Cardiff, Wales, United Kingdom (J.R.A.); P1Vital, University of Oxford, Warneford Hospital, Headington, Oxford, United Kingdom (G.R.D.); Alzheimer's Research UK, Granta Park, Great Abington, Cambridge, United Kingdom (D.S.R.); Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin (V.V.N.P.B.T., G.L., M.R.S., J.M.C.); and Division of Biochemistry and Molecular Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria (W.S.)
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Artelsmair M, Gu C, Lewis RJ, Elmore CS. Synthesis of C-14 labeled GABA A α2/α3 selective partial agonists and the investigation of late-occurring and long-circulating metabolites of GABA A receptor modulator AZD7325. J Labelled Comp Radiopharm 2018; 61:415-426. [PMID: 29314165 PMCID: PMC5969218 DOI: 10.1002/jlcr.3602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 12/26/2022]
Abstract
Anxiolytic activity has been associated with GABAA α2 and α3 subunits. Several target compounds were identified and required in C-14 labeled form to enable a better understanding of their drug metabolism and pharmacokinetic properties. AZD7325 is a selective GABAA α2 and α3 receptor modulator intended for the treatment of anxiety through oral administration. A great number of AZD7325 metabolites were observed across species in vivo, whose identification was aided by [14 C]AZD7325. An interesting metabolic cyclization and aromatization pathway leading to the tricyclic core of M9 and the oxidative pathways to M10 and M42 are presented.
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Affiliation(s)
- Markus Artelsmair
- Early Chemical Development, Pharmaceutical Sciences, IMED Biotech UnitAstraZenecaGothenburgSweden
| | - Chungang Gu
- DMPK, Oncology, IMED Biotech UnitAstraZenecaBostonMAUSA
| | - Richard J. Lewis
- Medicinal Chemistry, Respiratory, Inflammation and Autoimmunity, IMED Biotech UnitAstraZenecaGothenburgSweden
| | - Charles S. Elmore
- Early Chemical Development, Pharmaceutical Sciences, IMED Biotech UnitAstraZenecaGothenburgSweden
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Jamieson KH. Crisis or self-correction: Rethinking media narratives about the well-being of science. Proc Natl Acad Sci U S A 2018; 115:2620-2627. [PMID: 29531076 PMCID: PMC5856501 DOI: 10.1073/pnas.1708276114] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
After documenting the existence and exploring some implications of three alternative news narratives about science and its challenges, this essay outlines ways in which those who communicate science can more accurately convey its investigatory process, self-correcting norms, and remedial actions, without in the process legitimizing an unwarranted "science is broken/in crisis" narrative. The three storylines are: (i) quest discovery, which features scientists producing knowledge through an honorable journey; (ii) counterfeit quest discovery, which centers on an individual or group of scientists producing a spurious finding through a dishonorable one; and (iii) a systemic problem structure, which suggests that some of the practices that protect science are broken, or worse, that science is no longer self-correcting or in crisis.
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Affiliation(s)
- Kathleen Hall Jamieson
- Annenberg School for Communication, University of Pennsylvania, Philadelphia, PA 19104;
- Annenberg Public Policy Center, University of Pennsylvania, Philadelphia, PA 19104
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46
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Kato AS, Witkin JM. Protein complexes as psychiatric and neurological drug targets. Biochem Pharmacol 2018; 151:263-281. [PMID: 29330067 DOI: 10.1016/j.bcp.2018.01.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/05/2018] [Indexed: 12/25/2022]
Abstract
The need for improved medications for psychiatric and neurological disorders is clear. Difficulties in finding such drugs demands that all strategic means be utilized for their invention. The discovery of forebrain specific AMPA receptor antagonists, which selectively block the specific combinations of principal and auxiliary subunits present in forebrain regions but spare targets in the cerebellum, was recently disclosed. This discovery raised the possibility that other auxiliary protein systems could be utilized to help identify new medicines. Discussion of the TARP-dependent AMPA receptor antagonists has been presented elsewhere. Here we review the diversity of protein complexes of neurotransmitter receptors in the nervous system to highlight the broad range of protein/protein drug targets. We briefly outline the structural basis of protein complexes as drug targets for G-protein-coupled receptors, voltage-gated ion channels, and ligand-gated ion channels. This review highlights heterodimers, subunit-specific receptor constructions, multiple signaling pathways, and auxiliary proteins with an emphasis on the later. We conclude that the use of auxiliary proteins in chemical compound screening could enhance the detection of specific, targeted drug searches and lead to novel and improved medicines for psychiatric and neurological disorders.
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Affiliation(s)
- Akihiko S Kato
- Neuroscience Discovery, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, USA.
| | - Jeffrey M Witkin
- Neuroscience Discovery, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, USA
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Pálvölgyi A, Móricz K, Pataki Á, Mihalik B, Gigler G, Megyeri K, Udvari S, Gacsályi I, Antoni FA. Loop F of the GABA A receptor alpha subunit governs GABA potency. Neuropharmacology 2018; 128:408-415. [DOI: 10.1016/j.neuropharm.2017.10.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/29/2017] [Accepted: 10/31/2017] [Indexed: 12/28/2022]
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Stefanits H, Milenkovic I, Mahr N, Pataraia E, Hainfellner JA, Kovacs GG, Sieghart W, Yilmazer-Hanke D, Czech T. GABAAreceptor subunits in the human amygdala and hippocampus: Immunohistochemical distribution of 7 subunits. J Comp Neurol 2017; 526:324-348. [DOI: 10.1002/cne.24337] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 09/12/2017] [Accepted: 09/19/2017] [Indexed: 12/18/2022]
Affiliation(s)
- Harald Stefanits
- Department of Neurosurgery; Medical University of Vienna; Vienna Austria
- Institute of Neurology, Medical University of Vienna; Vienna Austria
| | - Ivan Milenkovic
- Department of Clinical Neurology; Medical University of Vienna; Vienna Austria
| | - Nina Mahr
- Department of Neurosurgery; Medical University of Vienna; Vienna Austria
| | - Ekaterina Pataraia
- Department of Clinical Neurology; Medical University of Vienna; Vienna Austria
| | | | - Gabor G. Kovacs
- Institute of Neurology, Medical University of Vienna; Vienna Austria
| | - Werner Sieghart
- Center for Brain Research, Department of Molecular Neurosciences; Medical University of Vienna; Vienna Austria
| | - Deniz Yilmazer-Hanke
- Clinical Neuroanatomy, Neurology Department, Medical Faculty; Ulm University; Ulm Germany
| | - Thomas Czech
- Department of Neurosurgery; Medical University of Vienna; Vienna Austria
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Novel Molecule Exhibiting Selective Affinity for GABA A Receptor Subtypes. Sci Rep 2017; 7:6230. [PMID: 28740086 PMCID: PMC5524711 DOI: 10.1038/s41598-017-05966-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 06/06/2017] [Indexed: 01/06/2023] Open
Abstract
Aminoquinoline derivatives were evaluated against a panel of receptors/channels/transporters in radioligand binding experiments. One of these derivatives (DCUK-OEt) displayed micromolar affinity for brain γ-aminobutyric acid type A (GABAA) receptors. DCUK-OEt was shown to be a positive allosteric modulator (PAM) of GABA currents with α1β2γ2, α1β3γ2, α5β3γ2 and α1β3δ GABAA receptors, while having no significant PAM effect on αβ receptors or α1β1γ2, α1β2γ1, α4β3γ2 or α4β3δ receptors. DCUK-OEt modulation of α1β2γ2 GABAA receptors was not blocked by flumazenil. The subunit requirements for DCUK-OEt actions distinguished DCUK-OEt from other currently known modulators of GABA function (e.g., anesthetics, neurosteroids or ethanol). Simulated docking of DCUK-OEt at the GABAA receptor suggested that its binding site may be at the α + β- subunit interface. In slices of the central amygdala, DCUK-OEt acted primarily on extrasynaptic GABAA receptors containing the α1 subunit and generated increases in extrasynaptic “tonic” current with no significant effect on phasic responses to GABA. DCUK-OEt is a novel chemical structure acting as a PAM at particular GABAA receptors. Given that neurons in the central amygdala responding to DCUK-OEt were recently identified as relevant for alcohol dependence, DCUK-OEt should be further evaluated for the treatment of alcoholism.
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Schwienteck KL, Li G, Poe MM, Cook JM, Banks ML, Negus SS. Abuse-related effects of subtype-selective GABA A receptor positive allosteric modulators in an assay of intracranial self-stimulation in rats. Psychopharmacology (Berl) 2017; 234:2091-2101. [PMID: 28365836 PMCID: PMC5875719 DOI: 10.1007/s00213-017-4615-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 03/22/2017] [Indexed: 12/21/2022]
Abstract
RATIONALE GABAA positive allosteric modulators (GABAA PAMs), such as diazepam and zolpidem, are used clinically for anxiety and insomnia, but abuse liability is a concern. Novel GABAA PAMS may have lower abuse liability while retaining clinical utility. OBJECTIVE The present study compared abuse-related effects of the non-selective GABAA PAM diazepam, the α1-selective GABAA PAM zolpidem, and three novel GABAA PAMs (JY-XHe-053, XHe-II-053, and HZ-166) using intracranial self-stimulation (ICSS) in rats. These novel compounds have relatively low efficacy at α1-, α2-, and α3-containing GABAA receptors, putative in vivo selectivity at α2/α3-containing GABAA receptors, and produce anxiolytic-like effects with limited sedation in non-human primates. METHODS Adult, male Sprague-Dawley rats (n = 17) were each implanted with a bipolar electrode in the medial forebrain bundle and trained to respond under a fixed-ratio 1 schedule of reinforcement for electrical brain stimulation. The potency and time course of effects were compared for diazepam (0.1-10 mg/kg), zolpidem (0.032-3.2 mg/kg), and the three novel compounds (JY-XHe-053, XHe-II-053, and HZ-166; all 3.2-32 mg/kg). RESULTS Zolpidem and diazepam produced transient facilitation of ICSS at small doses and more sustained rate-decreasing effects at larger doses. JY-XHe-053 and HZ-166 produced weak and inconsistent ICSS facilitation, whereas XHe-II-053 had no effect on ICSS. CONCLUSIONS These results support a key role for α1-containing GABAA receptors in mediating GABAA PAM-induced ICSS facilitation. These results are concordant with drug self-administration studies in monkeys in suggesting that GABAA PAMs with low α1 efficacy and putative α2/α3 selectivity have lower abuse liability than high-efficacy non-selective or α1-selective GABAA PAMs.
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Affiliation(s)
| | - Guanguan Li
- Dept of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI
| | - Michael M. Poe
- Dept of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI
| | - James M. Cook
- Dept of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI
| | - Matthew L. Banks
- Dept of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA
| | - S. Stevens Negus
- Dept of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA,Communicating Author: S. Stevens Negus, PhD, Department of Pharmacology and Toxicology, Virginia Commonwealth University, 410 North 12 Street, PO Box 980613, Richmond, VA 23298, Phone: 804-828-3158,
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