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Recent Advances in the Discovery of Nicotinic Acetylcholine Receptor Allosteric Modulators. Molecules 2023; 28:molecules28031270. [PMID: 36770942 PMCID: PMC9920195 DOI: 10.3390/molecules28031270] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/18/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Positive allosteric modulators (PAMs), negative allosteric modulators (NAMs), silent agonists, allosteric activating PAMs and neutral or silent allosteric modulators are compounds capable of modulating the nicotinic receptor by interacting at allosteric modulatory sites distinct from the orthosteric sites. This survey is focused on the compounds that have been shown or have been designed to interact with nicotinic receptors as allosteric modulators of different subtypes, mainly α7 and α4β2. Minimal chemical changes can cause a different pharmacological profile, which can then lead to the design of selective modulators. Experimental evidence supports the use of allosteric modulators as therapeutic tools for neurological and non-neurological conditions.
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Deba F, Munoz K, Peredia E, Akk G, Hamouda AK. Assessing potentiation of the (α4)3(β2)2 nicotinic acetylcholine receptor by the allosteric agonist CMPI. J Biol Chem 2021; 298:101455. [PMID: 34861241 PMCID: PMC8715118 DOI: 10.1016/j.jbc.2021.101455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/20/2021] [Accepted: 11/29/2021] [Indexed: 12/11/2022] Open
Abstract
The extracellular domain of the nicotinic acetylcholine receptor isoforms formed by three α4 and two β2 subunits ((α4)3(β2)2 nAChR) harbors two high-affinity “canonical” acetylcholine (ACh)-binding sites located in the two α4:β2 intersubunit interfaces and a low-affinity “noncanonical” ACh-binding site located in the α4:α4 intersubunit interface. In this study, we used ACh, cytisine, and nicotine (which bind at both the α4:α4 and α4:β2 interfaces), TC-2559 (which binds at the α4:β2 but not at the α4:α4 interface), and 3-(2-chlorophenyl)-5-(5-methyl-1-(piperidin-4-yl)-1H-pyrrazol-4-yl)isoxazole (CMPI, which binds at the α4:α4 but not at the α4:β2 interface), to investigate the binding and gating properties of CMPI at the α4:α4 interface. We recorded whole-cell currents from Xenopus laevis oocytes expressing (α4)3(β2)2 nAChR in response to applications of these ligands, alone or in combination. The electrophysiological data were analyzed in the framework of a modified Monod–Wyman–Changeux allosteric activation model. We show that CMPI is a high-affinity, high-efficacy agonist at the α4:α4 binding site and that its weak direct activating effect is accounted for by its inability to productively interact with the α4:β2 sites. The data presented here enhance our understanding of the functional contributions of ligand binding at the α4:α4 subunit interface to (α4)3(β2)2 nAChR-channel gating. These findings support the potential use of α4:α4 specific ligands to increase the efficacy of the neurotransmitter ACh in conditions associated with decline in nAChRs activity in the brain.
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Affiliation(s)
- Farah Deba
- Department of Pharmaceutical Sciences, The University of Texas at Tyler, Tyler, Texas, USA
| | - Kemburli Munoz
- Department of Pharmaceutical Sciences, Texas A&M HSC, Kingsville, Texas, USA
| | - Eloisa Peredia
- Department of Pharmaceutical Sciences, The University of Texas at Tyler, Tyler, Texas, USA
| | - Gustav Akk
- Department of Anesthesiology, Washington University in St. Louis, St. Louis, Missouri, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Ayman K Hamouda
- Department of Pharmaceutical Sciences, The University of Texas at Tyler, Tyler, Texas, USA.
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Hamouda AK, Bautista MR, Akinola LS, Alkhlaif Y, Jackson A, Carper M, Toma WB, Garai S, Chen YC, Thakur GA, Fowler CD, Damaj MI. Potentiation of (α4)2(β2)3, but not (α4)3(β2)2, nicotinic acetylcholine receptors reduces nicotine self-administration and withdrawal symptoms. Neuropharmacology 2021; 190:108568. [PMID: 33878302 DOI: 10.1016/j.neuropharm.2021.108568] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/28/2021] [Accepted: 04/10/2021] [Indexed: 11/26/2022]
Abstract
The low sensitivity (α4)3(β2)2 (LS) and high sensitivity (α4)2(β2)3 (HS) nAChR isoforms may contribute to a variety of brain functions, pathophysiological processes, and pharmacological effects associated with nicotine use. In this study, we examined the contributions of the LS and HS α4β2 nAChR isoforms in nicotine self-administration, withdrawal symptoms, antinociceptive and hypothermic effects. We utilized two nAChR positive allosteric modulators (PAMs): desformylflustrabromine (dFBr), a PAM of both the LS and HS α4β2 nAChRs, and CMPI, a PAM selective for the LS nAChR. We found that dFBr, but not CMPI, decreased intravenous nicotine self-administration in male mice in a dose-dependent manner. Unlike dFBr, which fully reverses somatic and affective symptoms of nicotine withdrawal, CMPI at doses up to 15 mg/kg in male mice only partially reduced nicotine withdrawal-induced somatic signs, anxiety-like behavior and sucrose preference, but had no effects on nicotine withdrawal-induced hyperalgesia. These results indicate that potentiation of HS α4β2 nAChRs is necessary to modulate nicotine's reinforcing properties that underlie nicotine intake and to reverse nicotine withdrawal symptoms that influence nicotine abstinence. In contrast, both dFBr and CMPI enhanced nicotine's hypothermic effect and reduced nicotine's antinociceptive effects in male mice. Therefore, these results indicate a more prevalent role of HS α4β2 nAChR isoforms in mediating various behavioral effects associated with nicotine, whereas the LS α4β2 nAChR isoform has a limited role in mediating body temperature and nociceptive responses. These findings will facilitate the development of more selective, efficacious, and safe nAChR-based therapeutics for nicotine addiction treatment.
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Affiliation(s)
- Ayman K Hamouda
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Texas at Tyler, Tyler, TX, USA.
| | - Malia R Bautista
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, CA, USA
| | - Lois S Akinola
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA
| | - Yasmin Alkhlaif
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA
| | - Asti Jackson
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA
| | - Moriah Carper
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA
| | - Wisam B Toma
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA
| | - Sumanta Garai
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Yen-Chu Chen
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, CA, USA
| | - Ganesh A Thakur
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Christie D Fowler
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, CA, USA
| | - M Imad Damaj
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA.
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4
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Moerke MJ, McMahon LR, Wilkerson JL. More than Smoke and Patches: The Quest for Pharmacotherapies to Treat Tobacco Use Disorder. Pharmacol Rev 2020; 72:527-557. [PMID: 32205338 DOI: 10.1124/pr.119.018028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Tobacco use is a persistent public health issue. It kills up to half its users and is the cause of nearly 90% of all lung cancers. The main psychoactive component of tobacco is nicotine, primarily responsible for its abuse-related effects. Accordingly, most pharmacotherapies for smoking cessation target nicotinic acetylcholine receptors (nAChRs), nicotine's major site of action in the brain. The goal of the current review is twofold: first, to provide a brief overview of the most commonly used behavioral procedures for evaluating smoking cessation pharmacotherapies and an introduction to pharmacokinetic and pharmacodynamic properties of nicotine important for consideration in the development of new pharmacotherapies; and second, to discuss current and potential future pharmacological interventions aimed at decreasing tobacco use. Attention will focus on the potential for allosteric modulators of nAChRs to offer an improvement over currently approved pharmacotherapies. Additionally, given increasing public concern for the potential health consequences of using electronic nicotine delivery systems, which allow users to inhale aerosolized solutions as an alternative to smoking tobacco, an effort will be made throughout this review to address the implications of this relatively new form of nicotine delivery, specifically as it relates to smoking cessation. SIGNIFICANCE STATEMENT: Despite decades of research that have vastly improved our understanding of nicotine and its effects on the body, only a handful of pharmacotherapies have been successfully developed for use in smoking cessation. Thus, investigation of alternative pharmacological strategies for treating tobacco use disorder remains active; allosteric modulators of nicotinic acetylcholine receptors represent one class of compounds currently under development for this purpose.
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Affiliation(s)
- M J Moerke
- Division of Preclinical Pharmacology, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland (M.J.M.) and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (L.R.M., J.L.W.)
| | - L R McMahon
- Division of Preclinical Pharmacology, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland (M.J.M.) and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (L.R.M., J.L.W.)
| | - J L Wilkerson
- Division of Preclinical Pharmacology, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland (M.J.M.) and Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida (L.R.M., J.L.W.)
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Allosterism of Nicotinic Acetylcholine Receptors: Therapeutic Potential for Neuroinflammation Underlying Brain Trauma and Degenerative Disorders. Int J Mol Sci 2020; 21:ijms21144918. [PMID: 32664647 PMCID: PMC7404387 DOI: 10.3390/ijms21144918] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/06/2020] [Accepted: 07/10/2020] [Indexed: 12/21/2022] Open
Abstract
Inflammation is a key physiological phenomenon that can be pervasive when dysregulated. Persistent chronic inflammation precedes several pathophysiological conditions forming one of the critical cellular homeostatic checkpoints. With a steady global surge in inflammatory diseases, it is imperative to delineate underlying mechanisms and design suitable drug molecules targeting the cellular partners that mediate and regulate inflammation. Nicotinic acetylcholine receptors have a confirmed role in influencing inflammatory pathways and have been a subject of scientific scrutiny underlying drug development in recent years. Drugs designed to target allosteric sites on the nicotinic acetylcholine receptors present a unique opportunity to unravel the role of the cholinergic system in regulating and restoring inflammatory homeostasis. Such a therapeutic approach holds promise in treating several inflammatory conditions and diseases with inflammation as an underlying pathology. Here, we briefly describe the potential of cholinergic allosterism and some allosteric modulators as a promising therapeutic option for the treatment of neuroinflammation.
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Deba F, Ramos K, Vannoy M, Munoz K, Akinola LS, Damaj MI, Hamouda AK. Examining the Effects of (α4)3(β2)2 Nicotinic Acetylcholine Receptor-Selective Positive Allosteric Modulator on Acute Thermal Nociception in Rats. Molecules 2020; 25:molecules25122923. [PMID: 32630476 PMCID: PMC7355939 DOI: 10.3390/molecules25122923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 12/14/2022] Open
Abstract
Neuronal nicotinic acetylcholine receptor (nAChR)-based therapeutics are sought as a potential alternative strategy to opioids for pain management. In this study, we examine the antinociceptive effects of 3-(2-chlorophenyl)-5-(5-methyl-1-(piperidin-4-yl)-1H-pyrazol-4-yl)isoxazole (CMPI), a novel positive allosteric modulator (PAM), with preferential selectivity to the low agonist sensitivity (α4)3(β2)2 nAChR and desformylflustrabromine (dFBr), a PAM for α4-containing nAChRs. We used hot plate and tail flick tests to measure the effect of dFBr and CMPI on the latency to acute thermal nociceptive responses in rats. Intraperitoneal injection of dFBr, but not CMPI, dose-dependently increased latency in the hot plate test. In the tail flick test, the effect achieved at the highest dFBr or CMPI dose tested was only <20% of the maximum possible effects reported for nicotine and other nicotinic agonists. Moreover, the coadministration of dFBr did not enhance the antinociceptive effect of a low dose of nicotine. Our results show that the direct acute effect of dFBr is superior to that for CMPI, indicating that selectivity to (α4)3(β2)2 nAChR is not advantageous in alleviating responses to acute thermal nociceptive stimulus. However, further studies are necessary to test the suitability of (α4)3(β2)2 nAChR-selective PAMs in chronic pain models.
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Affiliation(s)
- Farah Deba
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Texas at Tyler, Tyler, TX 75799, USA;
- Department of Pharmaceutical Sciences, College of Pharmacy, Texas A&M Health Sciences Center MS 131, 1010 W. Ave. B, Kingsville, TX 78363, USA; (K.R.); (M.V.); (K.M.)
| | - Kara Ramos
- Department of Pharmaceutical Sciences, College of Pharmacy, Texas A&M Health Sciences Center MS 131, 1010 W. Ave. B, Kingsville, TX 78363, USA; (K.R.); (M.V.); (K.M.)
| | - Matthew Vannoy
- Department of Pharmaceutical Sciences, College of Pharmacy, Texas A&M Health Sciences Center MS 131, 1010 W. Ave. B, Kingsville, TX 78363, USA; (K.R.); (M.V.); (K.M.)
| | - Kemburli Munoz
- Department of Pharmaceutical Sciences, College of Pharmacy, Texas A&M Health Sciences Center MS 131, 1010 W. Ave. B, Kingsville, TX 78363, USA; (K.R.); (M.V.); (K.M.)
| | - Lois S. Akinola
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Kontos Medical Science Building, 1217 E. Marshall St., P.O. Box 980613, Richmond, VA 23298, USA; (L.S.A.); (M.I.D.)
| | - M. Imad Damaj
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Kontos Medical Science Building, 1217 E. Marshall St., P.O. Box 980613, Richmond, VA 23298, USA; (L.S.A.); (M.I.D.)
| | - Ayman K. Hamouda
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Texas at Tyler, Tyler, TX 75799, USA;
- Department of Pharmaceutical Sciences, College of Pharmacy, Texas A&M Health Sciences Center MS 131, 1010 W. Ave. B, Kingsville, TX 78363, USA; (K.R.); (M.V.); (K.M.)
- Correspondence: ; Tel.: +1-903-565-6578
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Wilkerson JL, Deba F, Crowley ML, Hamouda AK, McMahon LR. Advances in the In vitro and In vivo pharmacology of Alpha4beta2 nicotinic receptor positive allosteric modulators. Neuropharmacology 2020; 168:108008. [PMID: 32113032 DOI: 10.1016/j.neuropharm.2020.108008] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 02/08/2020] [Accepted: 02/11/2020] [Indexed: 11/29/2022]
Abstract
Receptors containing α4 and β2 subunits are a major neuronal nicotinic acetylcholine receptor (nAChR) subtype in the brain. This receptor plays a critical role in nicotine addiction, with potential smoking cessation therapeutics producing modulation of α4β2 nAChR. In addition, compounds that act as agonists at α4β2 nAChR may be useful for the treatment of pathological pain. Further, as the α4β2 nAChR has been implicated in cognition, therapeutics that act as α4β2 nAChR agonists are also being examined as treatments for cognitive disorders and neurological diseases that impact cognitive function, such as Alzheimer's disease and schizophrenia. This review will cover the molecular in vitro evidence that allosteric modulators of the α4β2 neuronal nAChR provide several advantages over traditional α4β2 nAChR orthosteric ligands. Specifically, we explore the concept that nAChR allosteric modulators allow for greater pharmacological selectivity, while minimizing potential deleterious off-target effects. Further, here we discuss the development and preclinical in vivo behavioral assessment of allosteric modulators at the α4β2 neuronal nAChR as therapeutics for smoking cessation, pathological pain, as well as cognitive disorders and neurological diseases that impact cognitive function. This article is part of the special issue on 'Contemporary Advances in Nicotine Neuropharmacology'.
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Affiliation(s)
- Jenny L Wilkerson
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32610, United States.
| | - Farah Deba
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Texas at Tyler, Tyler, TX, 75799, United States
| | - Morgan L Crowley
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, 32610, United States
| | - Ayman K Hamouda
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Texas at Tyler, Tyler, TX, 75799, United States.
| | - Lance R McMahon
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, 32610, United States.
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Laikowski MM, Reisdorfer F, Moura S. NAChR α4β2 Subtype and their Relation with Nicotine Addiction, Cognition, Depression and Hyperactivity Disorder. Curr Med Chem 2019; 26:3792-3811. [PMID: 29637850 DOI: 10.2174/0929867325666180410105135] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 12/27/2017] [Accepted: 04/05/2018] [Indexed: 01/07/2023]
Abstract
BACKGROUND Neuronal α4β2 nAChRs are receptors involved in the role of neurotransmitters regulation and release, and this ionic channel participates in biological process of memory, learning and attention. This work aims to review the structure and functioning of the α4β2 nAChR emphasizing its role in the treatment of associated diseases like nicotine addiction and underlying pathologies such as cognition, depression and attention-deficit hyperactivity disorder. METHODS The authors realized extensive bibliographic research using the descriptors "Nicotine Receptor α4β2" and "cognition", "depression", "attention-deficit hyperactivity disorder", besides cross-references of the selected articles and after analysis of references in the specific literature. RESULTS As results, it was that found 179 relevant articles presenting the main molecules with affinity to nAChR α4β2 related to the cited diseases. The α4β2 nAChR subtype is a remarkable therapeutic target since this is the most abundant receptor in the central nervous system. CONCLUSION In summary, this review presents perspectives on the pharmacology and therapeutic targeting of α4β2 nAChRs for the treatment of cognition and diseases like nicotine dependence, depression and attention-deficit hyperactivity disorder.
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Affiliation(s)
- Manuela M Laikowski
- Laboratory of Natural and Synthetics Products, University of Caxias do Sul, Caxias do Sul, Brazil
| | - Fávero Reisdorfer
- Laboratory of Drug Development and Quality Control, University Federal of Pampa, Brazil
| | - Sidnei Moura
- Laboratory of Natural and Synthetics Products, University of Caxias do Sul, Caxias do Sul, Brazil
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Wang ZJ, Deba F, Mohamed TS, Chiara DC, Ramos K, Hamouda AK. Unraveling amino acid residues critical for allosteric potentiation of (α4)3(β2)2-type nicotinic acetylcholine receptor responses. J Biol Chem 2017; 292:9988-10001. [PMID: 28446611 DOI: 10.1074/jbc.m116.771246] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 04/20/2017] [Indexed: 01/29/2023] Open
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are promising drug targets to manage several neurological disorders and nicotine addiction. Growing evidence indicates that positive allosteric modulators of nAChRs improve pharmacological specificity by binding to unique sites present only in a subpopulation of nAChRs. Furthermore, nAChR positive allosteric modulators such as NS9283 and CMPI have been shown to potentiate responses of (α4)3(β2)2 but not (α4)2(β2)3 nAChR isoforms. This selective potentiation underlines that the α4:α4 interface, which is present only in the (α4)3(β2)2 nAChR, is an important and promising drug target. In this report we used site-directed mutagenesis to substitute specific amino acid residues and computational analyses to elucidate CMPI's binding mode at the α4:α4 subunit extracellular interface and identified a unique set of amino acid residues that determined its affinity. We found that amino acid residues α4Gly-41, α4Lys-64, and α4Thr-66 were critical for (α4)3(β2)2 nAChR potentiation by CMPI, but not by NS9283, whereas amino acid substitution at α4His-116, a known determinant of NS9283 and of agonist binding at the α4:α4 subunit interface, did not reduce CMPI potentiation. In contrast, substitutions at α4Gln-124 and α4Thr-126 reduced potentiation by CMPI and NS9283, indicating that their binding sites partially overlap. These results delineate the role of amino acid residues contributing to the α4:α4 subunit extracellular interface in nAChR potentiation. These findings also provide structural information that will facilitate the structure-based design of novel therapeutics that target selectively the (α4)3(β2)2 nAChR.
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Affiliation(s)
- Ze-Jun Wang
- From the Department of Pharmaceutical Sciences, Texas A&M Health Sciences Center, Kingsville, Texas 78363
| | - Farah Deba
- From the Department of Pharmaceutical Sciences, Texas A&M Health Sciences Center, Kingsville, Texas 78363
| | - Tasnim S Mohamed
- From the Department of Pharmaceutical Sciences, Texas A&M Health Sciences Center, Kingsville, Texas 78363
| | - David C Chiara
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Kara Ramos
- From the Department of Pharmaceutical Sciences, Texas A&M Health Sciences Center, Kingsville, Texas 78363
| | - Ayman K Hamouda
- From the Department of Pharmaceutical Sciences, Texas A&M Health Sciences Center, Kingsville, Texas 78363, .,Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Sciences Center, Bryan, Texas 77807, and
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Hamouda AK, Deba F, Wang ZJ, Cohen JB. Photolabeling a Nicotinic Acetylcholine Receptor (nAChR) with an (α4)3(β2)2 nAChR-Selective Positive Allosteric Modulator. Mol Pharmacol 2016; 89:575-84. [PMID: 26976945 DOI: 10.1124/mol.116.103341] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 03/09/2016] [Indexed: 01/25/2023] Open
Abstract
Positive allosteric modulators (PAMs) of nicotinic acetylcholine (ACh) receptors (nAChRs) have potential clinical applications in the treatment of nicotine dependence and many neuropsychiatric conditions associated with decreased brain cholinergic activity, and 3-(2-chlorophenyl)-5-(5-methyl-1-(piperidin-4-yl)-1H-pyrrazol-4-yl)isoxazole (CMPI) has been identified as a PAM selective for neuronal nAChRs containing theα4 subunit. In this report, we compare CMPI interactions with low-sensitivity (α4)3(β2)2 and high-sensitivity (α4)2(β2)3 nAChRs, and with muscle-type nAChRs. In addition, we use the intrinsic reactivity of [(3)H]CMPI upon photolysis at 312 nm to identify its binding sites inTorpedonAChRs. Recording fromXenopusoocytes, we found that CMPI potentiated maximally the responses of (α4)3(β2)2nAChR to 10μM ACh (EC10) by 400% and with anEC50of ∼1µM. CMPI produced a left shift of the ACh concentration-response curve without altering ACh efficacy. In contrast, CMPI inhibited (∼35% at 10µM) ACh responses of (α4)2(β2)3nAChRs and fully inhibited human muscle andTorpedonAChRs with IC50values of ∼0.5µM. Upon irradiation at 312 nm, [(3)H]CMPI photoincorporated into eachTorpedo[(α1)2β1γδ] nAChR subunit. Sequencing of peptide fragments isolated from [(3)H]CMPI-photolabeled nAChR subunits established photolabeling of amino acids contributing to the ACh binding sites (αTyr(190),αTyr(198),γTrp(55),γTyr(111),γTyr(117),δTrp(57)) that was fully inhibitable by agonist and lower-efficiency, state-dependent [(3)H]CMPI photolabeling within the ion channel. Our results establish that CMPI is a potent potentiator of nAChRs containing anα4:α4 subunit interface, and that its intrinsic photoreactivy makes it of potential use to identify its binding sites in the (α4)3(β2)2nAChR.
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Affiliation(s)
- Ayman K Hamouda
- Department of Pharmaceutical Sciences, Rangel College of Pharmacy, Texas A&M Health Sciences Center, Kingsville, Texas (A.K.H., F.D., Z.-J.W.); and Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (A.K.H., J.B.C.)
| | - Farah Deba
- Department of Pharmaceutical Sciences, Rangel College of Pharmacy, Texas A&M Health Sciences Center, Kingsville, Texas (A.K.H., F.D., Z.-J.W.); and Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (A.K.H., J.B.C.)
| | - Ze-Jun Wang
- Department of Pharmaceutical Sciences, Rangel College of Pharmacy, Texas A&M Health Sciences Center, Kingsville, Texas (A.K.H., F.D., Z.-J.W.); and Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (A.K.H., J.B.C.)
| | - Jonathan B Cohen
- Department of Pharmaceutical Sciences, Rangel College of Pharmacy, Texas A&M Health Sciences Center, Kingsville, Texas (A.K.H., F.D., Z.-J.W.); and Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (A.K.H., J.B.C.)
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11
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Mohamed TS, Jayakar SS, Hamouda AK. Orthosteric and Allosteric Ligands of Nicotinic Acetylcholine Receptors for Smoking Cessation. Front Mol Neurosci 2015; 8:71. [PMID: 26635524 PMCID: PMC4658446 DOI: 10.3389/fnmol.2015.00071] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/06/2015] [Indexed: 12/23/2022] Open
Abstract
Nicotine addiction, the result of tobacco use, leads to over six million premature deaths world-wide per year, a number that is expected to increase by a third within the next two decades. While more than half of smokers want and attempt to quit, only a small percentage of smokers are able to quit without pharmacological interventions. Therefore, over the past decades, researchers in academia and the pharmaceutical industry have focused their attention on the development of more effective smoking cessation therapies, which is now a growing 1.9 billion dollar market. Because the role of neuronal nicotinic acetylcholine receptors (nAChR) in nicotine addiction is well established, nAChR based therapeutics remain the leading strategy for smoking cessation. However, the development of neuronal nAChR drugs that are selective for a nAChR subpopulation is challenging, and only few neuronal nAChR drugs are clinically available. Among the many neuronal nAChR subtypes that have been identified in the brain, the α4β2 subtype is the most abundant and plays a critical role in nicotine addiction. Here, we review the role of neuronal nAChRs, especially the α4β2 subtype, in the development and treatment of nicotine addiction. We also compare available smoking cessation medications and other nAChR orthosteric and allosteric ligands that have been developed with emphasis on the difficulties faced in the development of clinically useful compounds with high nAChR subtype selectivity.
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Affiliation(s)
- Tasnim S Mohamed
- Department of Pharmaceutical Sciences, College of Pharmacy, Texas A&M Health Sciences Center Kingsville, TX, USA
| | - Selwyn S Jayakar
- Department of Neurobiology, Harvard Medical School Boston, MA, USA
| | - Ayman K Hamouda
- Department of Pharmaceutical Sciences, College of Pharmacy, Texas A&M Health Sciences Center Kingsville, TX, USA ; Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Sciences Center Bryan, TX, USA
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Grupe M, Jensen AA, Ahring PK, Christensen JK, Grunnet M. Unravelling the mechanism of action of NS9283, a positive allosteric modulator of (α4)3(β2)2 nicotinic ACh receptors. Br J Pharmacol 2015; 168:2000-10. [PMID: 23278456 DOI: 10.1111/bph.12095] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 11/22/2012] [Accepted: 12/14/2012] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND AND PURPOSE Strong implications in major neurological diseases make the neuronal α4β2 nicotinic ACh receptor (nAChR) a highly interesting drug target. In this study, we present a detailed electrophysiological characterization of NS9283, a potent positive allosteric modulator acting selectively at 3α:2β stoichiometry of α2* and α4* nAChRs. EXPERIMENTAL APPROACH The whole-cell patch-clamp technique equipped with an ultra-fast drug application system was used to perform electrophysiological characterization of NS9283 modulatory actions on human α4β2 nAChRs stably expressed in HEK293 cells (HEK293-hα4β2). KEY RESULTS NS9283 was demonstrated to increase the potency of ACh-evoked currents in HEK293-hα4β2 cells by left-shifting the concentration-response curve ~60-fold. Interestingly, this modulation did not significantly alter maximal efficacy levels of ACh. Further, NS9283 did not affect the rate of desensitization of ACh-evoked currents, was incapable of reactivating desensitized receptors and only moderately slowed recovery from desensitization. However, NS9283 strongly decreased the rate of deactivation kinetics and also modestly decreased the rate of activation. This resulted in a left-shift of the ACh window current of (α4)3(β2)2 nAChRs in the presence of NS9283. CONCLUSIONS AND IMPLICATIONS This study demonstrates that NS9283 increases responsiveness of human (α4)3(β2)2 nAChR to ACh with no change in maximum efficacy. We propose that this potentiation is due to a significant slowing of deactivation kinetics. In summary, the mechanism of action of NS9283 bears high resemblance to that of benzodiazepines at the GABAA receptor and to our knowledge, NS9283 constitutes the first nAChR compound of this class.
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Affiliation(s)
- M Grupe
- NeuroSearch A/S, Ballerup, Denmark.
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Sangepu B, Gandu B, Anupoju G, Jetti V. Synthesis of Isoxazole, 1, 2, 4-Oxadiazole and (1H-Pyrazol-4-yl)-methanone Oxime Derivatives fromN-Hydroxy-1H-pyrazole-4-carbimidoyl Chloride and their Biological Activity. J Heterocycl Chem 2015. [DOI: 10.1002/jhet.2309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Bhavanarushi Sangepu
- Fluoroorganic Division; CSIR-Indian Institute of Chemical Technology; Tarnaka Hyderabad 500607 India
| | - Bharath Gandu
- Bioengineering and Environmental Sciences; CSIR-Indian Institute of Chemical Technology; Tarnaka Hyderabad 500607 India
| | - Gangagnirao Anupoju
- Bioengineering and Environmental Sciences; CSIR-Indian Institute of Chemical Technology; Tarnaka Hyderabad 500607 India
| | - Vatsalarani Jetti
- Fluoroorganic Division; CSIR-Indian Institute of Chemical Technology; Tarnaka Hyderabad 500607 India
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Thiazole: a promising heterocycle for the development of potent CNS active agents. Eur J Med Chem 2014; 92:1-34. [PMID: 25544146 DOI: 10.1016/j.ejmech.2014.12.031] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 11/10/2014] [Accepted: 12/18/2014] [Indexed: 01/15/2023]
Abstract
Thiazole is a valuable scaffold in the field of medicinal chemistry and has accounted to display a variety of biological activities. Thiazole and its derivatives have attracted continuing interest to design various novel CNS active agents. In the past few decades, thiazoles have been widely used to develop a variety of therapeutic agents against numerous CNS targets. Thiazole containing drug molecules are currently being used in treatment of various CNS disorders and a number of thiazole derivatives are also presently in clinical trials. A lot of research has been carried out on thiazole and their analogues, which has proved their efficacy to overcome several CNS disorders in rodent as well as primate models. The aim of present review is to highlights diverse CNS activities displayed by thiazole and their derivatives. SAR of this nucleus has also been well discussed. This review covers the recent updates present in literature and will surely provide a greater insight for the designing and development of potent thiazole based CNS active agents in future.
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Fowler CD, Kenny PJ. Nicotine aversion: Neurobiological mechanisms and relevance to tobacco dependence vulnerability. Neuropharmacology 2014; 76 Pt B:533-44. [PMID: 24055497 PMCID: PMC3858456 DOI: 10.1016/j.neuropharm.2013.09.008] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 09/04/2013] [Accepted: 09/05/2013] [Indexed: 11/22/2022]
Abstract
Nicotine stimulates brain reward circuitries, most prominently the mesocorticolimbic dopamine system, and this action plays a critical in establishing and maintaining the tobacco smoking habit. Compounds that attenuate nicotine reward are considered promising therapeutic candidates for tobacco dependence, but many of these agents have other actions that limit their potential utility. Nicotine is also highly noxious, particularly at higher doses, and aversive reactions to nicotine after initial exposure can decrease the likelihood of developing a tobacco habit in many first time smokers. Nevertheless, relatively little is known about the mechanisms of nicotine aversion. The purpose of this review is to present recent new insights into the neurobiological mechanisms that regulate avoidance of nicotine. First, the role of the mesocorticolimbic system, so often associated with nicotine reward, in regulating nicotine aversion is highlighted. Second, genetic variation that modifies noxious responses to nicotine and thereby influences vulnerability to tobacco dependence, in particular variation in the CHRNA5-CHRNA3-CHRNB4 nicotinic acetylcholine receptor (nAChR) subunit gene cluster, will be discussed. Third, the role of the habenular complex in nicotine aversion, primarily medial habenular projections to the interpeduncular nucleus (IPN) but also lateral habenular projections to rostromedial tegmental nucleus (RMTg) and ventral tegmental area (VTA) are reviewed. Forth, brain circuits that are enriched in nAChRs, but whose role in nicotine avoidance has not yet been assessed, will be identified. Finally, the feasibility of developing novel therapeutic agents for tobacco dependence that act not by blocking nicotine reward but by enhancing nicotine avoidance will be considered. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.
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Affiliation(s)
- Christie D Fowler
- Laboratory of Behavioral and Molecular Neuroscience, Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
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Timmermann DB, Sandager-Nielsen K, Dyhring T, Smith M, Jacobsen AM, Nielsen EØ, Grunnet M, Christensen JK, Peters D, Kohlhaas K, Olsen GM, Ahring PK. Augmentation of cognitive function by NS9283, a stoichiometry-dependent positive allosteric modulator of α2- and α4-containing nicotinic acetylcholine receptors. Br J Pharmacol 2013; 167:164-82. [PMID: 22506660 DOI: 10.1111/j.1476-5381.2012.01989.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Positive allosteric modulation of α4β2 nicotinic acetylcholine (nACh) receptors could add a new dimension to the pharmacology and therapeutic approach to these receptors. The novel modulator NS9283 was therefore tested extensively. EXPERIMENTAL APPROACH Effects of NS9283 were evaluated in vitro using fluorescence-based Ca(2+) imaging and electrophysiological voltage clamp experiments in Xenopus oocytes, mammalian cells and thalamocortical neurons. In vivo the compound was tested in models covering a range of cognitive domains in mice and rats. KEY RESULTS NS9283 was shown to increase agonist-evoked response amplitude of (α4)(3) (β2)(2) nACh receptors in electrophysiology paradigms. (α2)(3) (β2)(2) , (α2)(3) (β4)(2) and (α4)(3) (β4)(2) were modulated to comparable extents, but no effects were detected at α3-containing or any 2α : 3β stoichiometry nACh receptors. Native nACh receptors in thalamocortical neurons similarly displayed DHβE-sensitive currents that were receptive to modulation. NS9283 had favourable effects on sensory information processing, as shown by reversal of PCP-disrupted pre-pulse inhibition. NS9283 further improved performance in a rat model of episodic memory (social recognition), a rat model of sustained attention (five-choice serial reaction time task) and a rat model of reference memory (Morris water maze). Importantly, the effects in the Morris water maze could be fully reversed with mecamylamine, a blocker of nACh receptors. CONCLUSIONS AND IMPLICATIONS These results provide compelling evidence that positive allosteric modulators acting at the (α4)(3) (β2)(2) nACh receptors can augment activity across a broad range of cognitive domains, and that α4β2 nACh receptor allosteric modulation therefore constitutes a promising therapeutic approach to symptomatic treatment of cognitive impairment.
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Futatsugi K, Mascitti V, Guimarães CR, Morishita N, Cai C, DeNinno MP, Gao H, Hamilton MD, Hank R, Harris AR, Kung DW, Lavergne SY, Lefker BA, Lopaze MG, McClure KF, Munchhof MJ, Preville C, Robinson RP, Wright SW, Bonin PD, Cornelius P, Chen Y, Kalgutkar AS. From partial to full agonism: Identification of a novel 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole as a full agonist of the human GPR119 receptor. Bioorg Med Chem Lett 2013. [DOI: 10.1016/j.bmcl.2012.10.119] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Pandya A, Yakel JL. Allosteric modulators of the α4β2 subtype of neuronal nicotinic acetylcholine receptors. Biochem Pharmacol 2011; 82:952-8. [PMID: 21596025 PMCID: PMC3162104 DOI: 10.1016/j.bcp.2011.04.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 04/28/2011] [Accepted: 04/29/2011] [Indexed: 02/07/2023]
Abstract
Nicotinic acetylcholine receptors are ligand-gated ion conducting transmembrane channels from the Cys-loop receptor super-family. The α4β2 subtype is the predominant heteromeric subtype of nicotinic receptors found in the brain. Allosteric modulators for α4β2 receptors interact at a site other than the orthosteric site where acetylcholine binds. Many compounds which act as allosteric modulators of the α4β2 receptors have been identified, with both positive and negative effects. Such allosteric modulators either increase or decrease the response induced by agonist on the α4β2 receptors. Here we discuss the concept of allosterism as it pertains to the α4β2 receptors and summarize the important features of allosteric modulators for this nicotinic receptor subtype.
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Affiliation(s)
- Anshul Pandya
- Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA.
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Williams DK, Wang J, Papke RL. Positive allosteric modulators as an approach to nicotinic acetylcholine receptor-targeted therapeutics: advantages and limitations. Biochem Pharmacol 2011; 82:915-30. [PMID: 21575610 DOI: 10.1016/j.bcp.2011.05.001] [Citation(s) in RCA: 208] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 04/28/2011] [Accepted: 05/02/2011] [Indexed: 11/16/2022]
Abstract
Neuronal nicotinic acetylcholine receptors (nAChR), recognized targets for drug development in cognitive and neuro-degenerative disorders, are allosteric proteins with dynamic interconversions between multiple functional states. Activation of the nAChR ion channel is primarily controlled by the binding of ligands (agonists, partial agonists, competitive antagonists) at conventional agonist binding sites, but is also regulated in either negative or positive ways by the binding of ligands to other modulatory sites. In this review, we discuss models for the activation and desensitization of nAChR, and the discovery of multiple types of ligands that influence those processes in both heteromeric nAChR, such as the high-affinity nicotine receptors of the brain, and homomeric α7-type receptors. In recent years, α7 nAChRs have been identified as a potential target for therapeutic indications leading to the development of α7-selective agonists and partial agonists. However, unique properties of α7 nAChR, including low probability of channel opening and rapid desensitization, may limit the therapeutic usefulness of ligands binding exclusively to conventional agonist binding sites. New enthusiasm for the therapeutic targeting of α7 has come from the identification of α7-selective positive allosteric modulators (PAMs) that work effectively on the intrinsic factors that limit α7 ion channel activation. While these new drugs appear promising for therapeutic development, we also consider potential caveats and possible limitations for their use, including PAM-insensitive forms of desensitization and cytotoxicity issues.
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Affiliation(s)
- Dustin K Williams
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL Neurocypres, United States
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A double Mannich approach to the synthesis of substituted piperidones—application to the synthesis of substituted E-ring analogues of methyllycaconitine. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.06.084] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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de Filippi G, Mogg AJ, Phillips KG, Zwart R, Sher E, Chen Y. The subtype-selective nicotinic acetylcholine receptor positive allosteric potentiator 2087101 differentially facilitates neurotransmission in the brain. Eur J Pharmacol 2010; 643:218-24. [PMID: 20624387 DOI: 10.1016/j.ejphar.2010.06.064] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 06/07/2010] [Accepted: 06/24/2010] [Indexed: 11/16/2022]
Abstract
Positive allosteric modulators of centrally expressed nicotinic acetylcholine receptors have therapeutic potentials in areas of cognition, motor function and reward. Several chemical classes of allosteric modulators that are selective for alpha7 nicotinic receptors have been characterised, but potentiators for the most widely expressed alpha4beta2 nicotinic receptor subtype are few and less defined, owing probably to the difficulty to achieve selectivity over other heteromeric receptor subtypes. 2087101 (2-amino-5-keto)thiazole) is a potent potentiator of both alpha7 and alpha4beta2 receptors and it has selectivity against the alpha3beta4 subtype, which may be responsible for the undesirable peripheral side effects. To further characterise its ability to differentiate between native nicotinic receptors, we examined the effects of 2087101 on alpha7, alpha4beta2* and alpha3beta4* receptor-mediated responses in the rat brain in electrophysiological and neurochemical experiments. 2087101 significantly potentiated agonist-induced, alpha7 and non-alpha7 receptor-mediated, GABAergic postsynaptic currents in cultured hippocampal neurones, but not the nicotine-stimulated [(3)H]noradrenaline release from hippocampal slices, which was primarily mediated by alpha3beta4* receptors, confirming its selectivity for alpha7 and alpha4beta2* receptors in native systems. 2087101 also significantly enhanced nicotine-stimulated firing increase in dopamine neurones of the ventral tegmental area, an effect that was dihydro-beta-erythroidine-sensitive and thereby mediated by alpha4beta2* nicotinic receptors. 2087101 can therefore enhance native nicotinic activities mediated by alpha7 and alpha4beta2*, but not alpha3beta4* receptors, showing its unique ability to discriminate between native heteromeric nicotinic receptor subtypes and its therapeutic potential for treating brain disorders by concurrent modulation of both alpha7 and alpha4beta2* nicotinic receptors.
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Gao B, Hierl M, Clarkin K, Juan T, Nguyen H, van der Valk M, Deng H, Guo W, Lehto SG, Matson D, McDermott JS, Knop J, Gaida K, Cao L, Waldon D, Albrecht BK, Boezio AA, Copeland KW, Harmange JC, Springer SK, Malmberg AB, McDonough SI. Pharmacological effects of nonselective and subtype-selective nicotinic acetylcholine receptor agonists in animal models of persistent pain. Pain 2010; 149:33-49. [DOI: 10.1016/j.pain.2010.01.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 12/16/2009] [Accepted: 01/11/2010] [Indexed: 12/20/2022]
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The Role of Fluorine in the Discovery and Optimization of CNS Agents. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2010. [DOI: 10.1016/s0065-7743(10)45026-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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