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Brockmöller S, Worek F, Rothmiller S. Protein networking: nicotinic acetylcholine receptors and their protein-protein-associations. Mol Cell Biochem 2024; 479:1627-1642. [PMID: 38771378 DOI: 10.1007/s11010-024-05032-x] [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: 01/22/2024] [Accepted: 05/04/2024] [Indexed: 05/22/2024]
Abstract
Nicotinic acetylcholine receptors (nAChR) are complex transmembrane proteins involved in neurotransmission in the nervous system and at the neuromuscular junction. nAChR disorders may lead to severe, potentially fatal pathophysiological states. To date, the receptor has been the focus of basic and applied research to provide novel therapeutic interventions. Since most studies have investigated only the nAChR itself, it is necessary to consider the receptor as part of its protein network to understand or elucidate-specific pathways. On its way through the secretory pathway, the receptor interacts with several chaperones and proteins. This review takes a closer look at these molecular interactions and focuses especially on endoplasmic reticulum biogenesis, secretory pathway sorting, Golgi maturation, plasma membrane presentation, retrograde internalization, and recycling. Additional knowledge regarding the nAChR protein network may lead to a more detailed comprehension of the fundamental pathomechanisms of diseases or may lead to the discovery of novel therapeutic drug targets.
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Affiliation(s)
- Sabrina Brockmöller
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Bavaria, Germany.
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Bavaria, Germany
| | - Simone Rothmiller
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Bavaria, Germany
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2
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Shan H, Wang N, Gao X, Wang Z, Yu J, Zhangsun D, Zhu X, Luo S. Fluorescent α-Conotoxin [Q1G, ΔR14]LvIB Identifies the Distribution of α7 Nicotinic Acetylcholine Receptor in the Rat Brain. Mar Drugs 2024; 22:200. [PMID: 38786593 PMCID: PMC11122421 DOI: 10.3390/md22050200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024] Open
Abstract
α7 nicotinic acetylcholine receptors (nAChRs) are mainly distributed in the central nervous system (CNS), including the hippocampus, striatum, and cortex of the brain. The α7 nAChR has high Ca2+ permeability and can be quickly activated and desensitized, and is closely related to Alzheimer's disease (AD), epilepsy, schizophrenia, lung cancer, Parkinson's disease (PD), inflammation, and other diseases. α-conotoxins from marine cone snail venom are typically short, disulfide-rich neuropeptides targeting nAChRs and can distinguish various subtypes, providing vital pharmacological tools for the functional research of nAChRs. [Q1G, ΔR14]LvΙB is a rat α7 nAChRs selective antagonist, modified from α-conotoxin LvΙB. In this study, we utilized three types of fluorescein after N-Hydroxy succinimide (NHS) activation treatment: 6-TAMRA-SE, Cy3 NHS, and BODIPY-FL NHS, labeling the N-Terminal of [Q1G, ΔR14]LvΙB under weak alkaline conditions, obtaining three fluorescent analogs: LvIB-R, LvIB-C, and LvIB-B, respectively. The potency of [Q1G, ΔR14]LvΙB fluorescent analogs was evaluated at rat α7 nAChRs expressed in Xenopus laevis oocytes. Using a two-electrode voltage clamp (TEVC), the half-maximal inhibitory concentration (IC50) values of LvIB-R, LvIB-C, and LvIB-B were 643.3 nM, 298.0 nM, and 186.9 nM, respectively. The stability of cerebrospinal fluid analysis showed that after incubation for 12 h, the retention rates of the three fluorescent analogs were 52.2%, 22.1%, and 0%, respectively. [Q1G, ΔR14]LvΙB fluorescent analogs were applied to explore the distribution of α7 nAChRs in the hippocampus and striatum of rat brain tissue and it was found that Cy3- and BODIPY FL-labeled [Q1G, ΔR14]LvΙB exhibited better imaging characteristics than 6-TAMARA-. It was also found that α7 nAChRs are widely distributed in the cerebral cortex and cerebellar lobules. Taking into account potency, imaging, and stability, [Q1G, ΔR14]LvΙB -BODIPY FL is an ideal pharmacological tool to investigate the tissue distribution and function of α7 nAChRs. Our findings not only provide a foundation for the development of conotoxins as visual pharmacological probes, but also demonstrate the distribution of α7 nAChRs in the rat brain.
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Affiliation(s)
- Hongyu Shan
- Guangxi Key Laboratory of Special Biomedicine, School of Medicine, Guangxi University, Nanning 530004, China; (H.S.); (N.W.); (X.G.); (Z.W.); (J.Y.); (D.Z.)
| | - Nan Wang
- Guangxi Key Laboratory of Special Biomedicine, School of Medicine, Guangxi University, Nanning 530004, China; (H.S.); (N.W.); (X.G.); (Z.W.); (J.Y.); (D.Z.)
| | - Xinyu Gao
- Guangxi Key Laboratory of Special Biomedicine, School of Medicine, Guangxi University, Nanning 530004, China; (H.S.); (N.W.); (X.G.); (Z.W.); (J.Y.); (D.Z.)
| | - Zihan Wang
- Guangxi Key Laboratory of Special Biomedicine, School of Medicine, Guangxi University, Nanning 530004, China; (H.S.); (N.W.); (X.G.); (Z.W.); (J.Y.); (D.Z.)
| | - Jinpeng Yu
- Guangxi Key Laboratory of Special Biomedicine, School of Medicine, Guangxi University, Nanning 530004, China; (H.S.); (N.W.); (X.G.); (Z.W.); (J.Y.); (D.Z.)
| | - Dongting Zhangsun
- Guangxi Key Laboratory of Special Biomedicine, School of Medicine, Guangxi University, Nanning 530004, China; (H.S.); (N.W.); (X.G.); (Z.W.); (J.Y.); (D.Z.)
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
| | - Xiaopeng Zhu
- Guangxi Key Laboratory of Special Biomedicine, School of Medicine, Guangxi University, Nanning 530004, China; (H.S.); (N.W.); (X.G.); (Z.W.); (J.Y.); (D.Z.)
| | - Sulan Luo
- Guangxi Key Laboratory of Special Biomedicine, School of Medicine, Guangxi University, Nanning 530004, China; (H.S.); (N.W.); (X.G.); (Z.W.); (J.Y.); (D.Z.)
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China
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3
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Obiol DJ, Amundarain MJ, Zamarreño F, Vietri A, Antollini SS, Costabel MD. Oleic Acid Could Act as a Channel Blocker in the Inhibition of nAChR: Insights from Molecular Dynamics Simulations. J Phys Chem B 2024; 128:2398-2411. [PMID: 38445598 DOI: 10.1021/acs.jpcb.3c07067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
The activation of the muscular nicotinic acetylcholine receptor (nAChR) produces the opening of the channel, with the consequent increase in the permeability of cations, triggering an excitatory signal. Free fatty acids (FFA) are known to modulate the activity of the receptor as noncompetitive antagonists, acting at the membrane-AChR interface. We present molecular dynamics simulations of a model of nAChR in a desensitized closed state embedded in a lipid bilayer in which distinct membrane phospholipids were replaced by two different monounsaturated FFA that differ in the position of a double bond. This allowed us to detect and describe that the cis-18:1ω-9 FFA were located at the interface between the transmembrane segments of α2 and γ subunits diffused into the channel lumen with the consequent potential ability to block the channel to the passage of ions.
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Affiliation(s)
- Diego J Obiol
- Instituto de Física del Sur (IFISUR), Departamento de Física, Universidad Nacional del Sur (UNS), CONICET, Avenida Leandro N. Alem 1253, B8000CPB Bahía Blanca, Argentina
| | - María J Amundarain
- Instituto de Física del Sur (IFISUR), Departamento de Física, Universidad Nacional del Sur (UNS), CONICET, Avenida Leandro N. Alem 1253, B8000CPB Bahía Blanca, Argentina
- Department of Chemistry, Organic Chemistry III, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Fernando Zamarreño
- Instituto de Física del Sur (IFISUR), Departamento de Física, Universidad Nacional del Sur (UNS), CONICET, Avenida Leandro N. Alem 1253, B8000CPB Bahía Blanca, Argentina
| | - Agustín Vietri
- Instituto de Física del Sur (IFISUR), Departamento de Física, Universidad Nacional del Sur (UNS), CONICET, Avenida Leandro N. Alem 1253, B8000CPB Bahía Blanca, Argentina
| | - Silvia S Antollini
- Instituto de Investigaciones Bioquímicas de Bahía Blanca CONICET-UNS, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, B8000FWB Bahía Blanca, Argentina
| | - Marcelo D Costabel
- Instituto de Física del Sur (IFISUR), Departamento de Física, Universidad Nacional del Sur (UNS), CONICET, Avenida Leandro N. Alem 1253, B8000CPB Bahía Blanca, Argentina
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4
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Munafó JP, Biscussi B, Obiol D, Costabel M, Bouzat C, Murray AP, Antollini S. New Multitarget Molecules Derived from Caffeine as Potentiators of the Cholinergic System. ACS Chem Neurosci 2024; 15:994-1009. [PMID: 38407056 DOI: 10.1021/acschemneuro.3c00710] [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] [Indexed: 02/27/2024] Open
Abstract
Cholinergic deficit is a characteristic factor of several pathologies, such as myasthenia gravis, some types of congenital myasthenic syndromes, and Alzheimer's Disease. Two molecular targets for its treatment are acetylcholinesterase (AChE) and nicotinic acetylcholine receptor (nAChR). In previous studies, we found that caffeine behaves as a partial nAChR agonist and confirmed that it inhibits AChE. Here, we present new bifunctional caffeine derivatives consisting of a theophylline ring connected to amino groups by different linkers. All of them were more potent AChE inhibitors than caffeine. Furthermore, although some of them also activated muscle nAChR as partial agonists, not all of them stabilized nAChR in its desensitized conformation. To understand the molecular mechanism underlying these results, we performed docking studies on AChE and nAChR. The nAChR agonist behavior of the compounds depends on their accessory group, whereas their ability to stabilize the receptor in a desensitized state depends on the interactions of the linker at the binding site. Our results show that the new compounds can inhibit AChE and activate nAChR with greater potency than caffeine and provide further information on the modulation mechanisms of pharmacological targets for the design of novel therapeutic interventions in cholinergic deficit.
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Affiliation(s)
- Juan Pablo Munafó
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Camino La Carrindanga km 7, Bahía Blanca 8000, Argentina
| | - Brunella Biscussi
- Instituto de Química del Sur, Departamento de Química, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Avda. Alem 1253, Bahía Blanca 8000, Argentina
| | - Diego Obiol
- Grupo de Biofísica, Instituto de Física del Sur, Departamento de Física, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Avda. Alem 1253, Bahía Blanca 8000, Argentina
| | - Marcelo Costabel
- Grupo de Biofísica, Instituto de Física del Sur, Departamento de Física, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Avda. Alem 1253, Bahía Blanca 8000, Argentina
| | - Cecilia Bouzat
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Camino La Carrindanga km 7, Bahía Blanca 8000, Argentina
| | - Ana Paula Murray
- Instituto de Química del Sur, Departamento de Química, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Avda. Alem 1253, Bahía Blanca 8000, Argentina
| | - Silvia Antollini
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas, Camino La Carrindanga km 7, Bahía Blanca 8000, Argentina
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5
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Antollini SS, Barrantes FJ. Carlos Gutiérrez-Merino: Synergy of Theory and Experimentation in Biological Membrane Research. Molecules 2024; 29:820. [PMID: 38398572 PMCID: PMC10893188 DOI: 10.3390/molecules29040820] [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: 01/12/2024] [Revised: 02/06/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
Professor Carlos Gutiérrez-Merino, a prominent scientist working in the complex realm of biological membranes, has made significant theoretical and experimental contributions to the field. Contemporaneous with the development of the fluid-mosaic model of Singer and Nicolson, the Förster resonance energy transfer (FRET) approach has become an invaluable tool for studying molecular interactions in membranes, providing structural insights on a scale of 1-10 nm and remaining important alongside evolving perspectives on membrane structures. In the last few decades, Gutiérrez-Merino's work has covered multiple facets in the field of FRET, with his contributions producing significant advances in quantitative membrane biology. His more recent experimental work expanded the ground concepts of FRET to high-resolution cell imaging. Commencing in the late 1980s, a series of collaborations between Gutiérrez-Merino and the authors involved research visits and joint investigations focused on the nicotinic acetylcholine receptor and its relation to membrane lipids, fostering a lasting friendship.
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Affiliation(s)
- Silvia S. Antollini
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Instituto de Investigaciones Bioquímicas de Bahía Blanca (CONICET-UNS), Bahía Blanca 8000, Argentina;
| | - Francisco J. Barrantes
- Laboratory of Molecular Neurobiology, BIOMED UCA-CONICET, Buenos Aires C1107AAZ, Argentina
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Ledneczki I, Némethy Z, Molnár KD, Tapolcsányi P, Ilkei V, Vágó I, Kolok S, Thán M, Laszy J, Balázs O, Krámos B, Szigetvári Á, Bata I, Makó A, Visegrády A, Fodor L, Vastag M, Lévay G, Lendvai B, Greiner I, Éles J. Optimization of Novel α7 Nicotinic Acetylcholine Receptor Positive Allosteric Modulators and the Discovery of a Preclinical Development Candidate Molecule (RGH-560). J Med Chem 2023; 66:16276-16302. [PMID: 37989278 DOI: 10.1021/acs.jmedchem.3c01635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
During optimization of a previously identified lead compound, attempts were made to optimize the reactive indole structural element, the suboptimal metabolic stability, as well as the low kinetic solubility. It was concluded that the indole was important for in vitro activity. With the aim of further improvements, more thorough modifications were also carried out. As a result, a new chemotype (the azetidinespirochromone family) was identified, which proved to be 1 order of magnitude less lipophilic retaining the same high level of in vitro potency as the lead series itself, however, with improved metabolic stability and kinetic solubility. Compound 53 showed the most balanced physicochemical and pharmacological profile with significant in vivo efficacy in the scopolamine-induced amnesia test. Based on these promising results, cognitive enhancement through the positive modulation of α7 nAChRs appears to be a viable approach. Compound 53 was selected to be a preclinical development candidate (as RGH-560).
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Affiliation(s)
| | - Zsolt Némethy
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | | | - Pál Tapolcsányi
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Viktor Ilkei
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - István Vágó
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Sándor Kolok
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Márta Thán
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Judit Laszy
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Ottilia Balázs
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Balázs Krámos
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Áron Szigetvári
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Imre Bata
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Attila Makó
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | | | - László Fodor
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Mónika Vastag
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - György Lévay
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - Balázs Lendvai
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - István Greiner
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
| | - János Éles
- Gedeon Richter Plc, 19-21 Gyömői útca, Budapest H-1103, Hungary
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Hamanaka S, Kishi T, Sakuma K, Nishii Y, Hatano M, Iwata N. Serotonin 3 receptor antagonists for obsessive-compulsive disorder: A systematic review and pairwise meta-analysis. J Psychiatr Res 2023; 167:132-138. [PMID: 37866327 DOI: 10.1016/j.jpsychires.2023.10.029] [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: 03/12/2023] [Revised: 08/23/2023] [Accepted: 10/14/2023] [Indexed: 10/24/2023]
Abstract
The benefits of serotonin 3 receptor antagonists (5-HT3R-As) in obsessive-compulsive disorder (OCD) treatment remain unclear. Thus, this study aimed to perform a systematic review and a random-effects meta-analysis, including double-blind, randomized, placebo-controlled trials (DBRPCTs). The outcomes include the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) total score (primary), Y-BOCS obsession subscale score, Y-BOCS compulsive subscale score, treatment response, remission rate, all-cause discontinuation, and incidence of individual adverse events (nervousness/restlessness/anxiety, insomnia, headache, dizziness/lightheadedness, decreased appetite, constipation, nausea/vomiting, diarrhea, dry mouth, sweating/increased perspiration, itching/pruritus, tremor, and sexual dysfunction/decreased libido). The mean differences (MD) for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals (CIs) were calculated. Our study included 10 DBRPCTs (n = 628). Pooled 5-HT3R-As outperformed placebo regarding Y-BOCS total score (MD = -5.08, 95% CI = -7.04, -3.12, N = 9, n = 560), Y-BOCS obsession subscale score, Y-BOCS compulsive subscale score, treatment response, and remission rate. Individually, all 5-HT3R-As outperformed placebo regarding Y-BOCS total score (granisetron: MD = -5.59, 95% CI = -8.79, -2.39, N = 3, n = 178, ondansetron: MD = -5.72, 95% CI = -8.06, -3.37, N = 6, n = 331, tropisetron: MD = -2.87, 95% CI = -5.19, -0.550, N = 1, n = 96). However, all-cause discontinuation and incidence of individual adverse events between pooled 5-HT3R-As and placebo were not significantly different. In conclusion, our meta-analysis suggested 5-HT3R-As as efficacious for symptom improvement in individuals with OCD. However, the number of individuals included in each study was small; thus, a replication randomized trial of 5-HT3R-As should be conducted using a larger sample size.
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Affiliation(s)
- Shun Hamanaka
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, 470-1192, Japan
| | - Taro Kishi
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, 470-1192, Japan.
| | - Kenji Sakuma
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, 470-1192, Japan
| | - Yasufumi Nishii
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, 470-1192, Japan
| | - Masakazu Hatano
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, 470-1192, Japan; Department of Clinical Pharmacy, Fujita Health University School of Medicine, Toyoake, Aichi, 470-1192, Japan
| | - Nakao Iwata
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, 470-1192, Japan
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Quareshy M, Shanmugam M, Cameron AD, Bugg TDH, Chen Y. Characterisation of an unusual cysteine pair in the Rieske carnitine monooxygenase CntA catalytic site. FEBS J 2023; 290:2939-2953. [PMID: 36617384 PMCID: PMC10952381 DOI: 10.1111/febs.16722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 12/01/2022] [Accepted: 01/06/2023] [Indexed: 01/09/2023]
Abstract
Rieske monooxygenases undertake complex catalysis integral to marine, terrestrial and human gut-ecosystems. Group-I to -IV Rieske monooxygenases accept aromatic substrates and have well-characterised catalytic mechanisms. Nascent to our understanding are Group-V members catalysing the oxidation/breakdown of quaternary ammonium substrates. Phylogenetic analysis of Group V highlights a cysteine residue-pair adjacent to the mononuclear Fe active site with no established role. Following our elucidation of the carnitine monooxygenase CntA structure, we probed the function of the cysteine pair Cys206/Cys209. Utilising biochemical and biophysical techniques, we found the cysteine residues do not play a structural role nor influence the electron transfer pathway, but rather are used in a nonstoichiometric role to ensure the catalytic iron centre remains in an Fe(II) state.
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Affiliation(s)
| | | | | | | | - Yin Chen
- School of Life SciencesUniversity of WarwickCoventryUK
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9
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Elgoyhen AB. The α9α10 acetylcholine receptor: a non-neuronal nicotinic receptor. Pharmacol Res 2023; 190:106735. [PMID: 36931539 DOI: 10.1016/j.phrs.2023.106735] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/06/2023] [Accepted: 03/14/2023] [Indexed: 03/17/2023]
Abstract
Within the superfamily of pentameric ligand-gated ion channels, cholinergic nicotinic receptors (nAChRs) were classically identified to mediate synaptic transmission in the nervous system and the neuromuscular junction. The α9 and α10 nAChR subunits were the last ones to be identified. Surprisingly, they do not fall into the dichotomic neuronal/muscle classification of nAChRs. They assemble into heteropentamers with a well-established function as canonical ion channels in inner ear hair cells, where they mediate central nervous system control of auditory and vestibular sensory processing. The present review includes expression, pharmacological, structure-function, molecular evolution and pathophysiological studies, that define receptors composed from α9 and α10 subunits as distant and distinct members within the nAChR family. Thus, although α9 and α10 were initially included within the neuronal subdivision of nAChR subunits, they form a distinct clade within the phylogeny of nAChRs. Following the classification of nAChR subunits based on their main synaptic site of action, α9 and α10 should receive a name in their own right.
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Affiliation(s)
- Ana Belén Elgoyhen
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Vuelta de Obligado 2490, Buenos Aires 1428, Argentina.
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10
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Membrane lipid organization and nicotinic acetylcholine receptor function: A two-way physiological relationship. Arch Biochem Biophys 2022; 730:109413. [DOI: 10.1016/j.abb.2022.109413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 09/07/2022] [Accepted: 09/20/2022] [Indexed: 11/21/2022]
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11
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Shafiee Z, Karami L, Akbari M, Rezaee E, Maaza M, Tabatabai SA, Karimi G. Insights into the molecular mechanism of triazolopyrimidinone derivatives effects on the modulation of α 1β 2γ 2 subtype of GABA A receptor: An in silico approach. Arch Biochem Biophys 2022; 729:109380. [PMID: 36027937 DOI: 10.1016/j.abb.2022.109380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 07/30/2022] [Accepted: 08/18/2022] [Indexed: 11/25/2022]
Abstract
Due to the importance of benzodiazepine drugs in clinical practice, such as the treatment of anxiety disorders, depression, and insomnia and the side effects of classical benzodiazepines, the study of new benzodiazepine agonists has received much attentions. In this work, we used in silico methods to explore the molecular mechanism of 1,2,4-triazolo [1,5--a] pyrimidinone derivatives in the modulation of α1β2γ2 subtype of GABAA receptor. To this aim, molecular docking, molecular dynamics simulation (MD), post-MD analysis, binding free energy calculation, and prediction of ADME properties were performed. Results showed that all new compounds have a better binding affinity for the Benzodiazepine (BZD) site of the receptor than diazepam and compound 4c had the highest affinity among them. Moreover, a good agreement was observed between the calculated ΔGbinding and experimental IC50 values. Also, we noticed that residues in loop regions (particularly loop C and D-F in α1 and γ2 subunits, respectively) forming BZD binding site, take part in forming several H-bonds between the agonists and the receptor. Ser205, Thr207, Tyr160, and His102 of α1 subunit and Thr207 of γ2 subunit are mainly involved in forming H-bonds. Also, the orientation of agonists in the BZD binding site leads to π-π interactions with hydrophobic residues in loops A-F. Based on the DCCM analysis, the correlated motions in the γ2 subunit residues are greater than those of α1 subunit residues. Further, predicted ADME results indicated that all agonists meet the criteria. The triplicate MD simulation showed the reproducibility of the results and strengthened the study. Our results provide a comprehensive insight into the receptor-agonist interactions and clues for designing future BZD agonists.
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Affiliation(s)
- Zohreh Shafiee
- Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Leila Karami
- Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran.
| | - Mahmood Akbari
- UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P.O. Box 392, Pretoria, South Africa; Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, Old Faure Road, 7129, Somerset West, South Africa
| | - Elham Rezaee
- Department of Pharmaceutical Chemistry, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Malik Maaza
- UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, P.O. Box 392, Pretoria, South Africa; Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, Old Faure Road, 7129, Somerset West, South Africa
| | - Sayyed Abbas Tabatabai
- Department of Pharmaceutical Chemistry, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Gilda Karimi
- Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
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12
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Fabiani C, Biscussi B, Munafo JP, Murray AP, Corradi J, Antollini SS. NEW SYNTHETIC CAFFEINE ANALOGS AS MODULATORS OF THE CHOLINERGIC SYSTEM. Mol Pharmacol 2021; 101:154-167. [PMID: 34969831 DOI: 10.1124/molpharm.121.000415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/26/2021] [Indexed: 11/22/2022] Open
Abstract
Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder. Since cholinergic deficit is a major factor in this disease, two molecular targets for its treatment are the acetylcholinesterase (AChE) and the nicotinic acetylcholine receptors (nAChRs). Given that caffeine is a natural compound that behaves as an AChE inhibitor and as a partial agonist of nAChRs, the aim of this work was to synthetize more potent bifunctional caffeine analogs that modulate these two molecular targets. To this end, a theophylline structure was connected to a pyrrolidine structure through a methylene chain of different lengths (3 to 7 carbon atoms) to give compounds 7-11 All caffeine derivatives inhibited the AChE, of which compound 11 showed the strongest effect. Electrophysiological studies showed that all compounds behave as agonists of the muscle and the neuronal α7 nAChR with greater potency than caffeine. To explore if the different analogs could affect the nAChR conformational state, the nAChR conformational-sensitive probe crystal violet (CrV) was used. Compounds 9 and 10 conduced the nAChR to a different conformational state comparable with a control nAChR desensitized state. Finally, molecular docking experiments showed that all derivatives interacted with both the catalytic and anionic sites of AChE and with the orthosteric binding site of the nAChR. Thus, the new synthetized compounds can inhibit the AChE and activate muscle and α7 nAChRs with greater potency than caffeine, which suggests that they could be useful leaders for the development of new therapies for the treatment of different neurological diseases. Significance Statement In this work we synthetized caffeine derivatives which can inhibit the AChE and activate both muscle and α7 nAChRs with higher potency than caffeine. These analogs can be divided into two groups: a non-desensitizing and a desensitizing nAChR group. From the nAChR-non desensitizing group, we propose compound 11 as the most interesting analog for further studies since it inhibits AChE with the highest potency and activates the nAChRs in the picomolar range without inducing receptor desensitization.
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Affiliation(s)
- Camila Fabiani
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur y Consejo Nacional de Investigaciones Científicas y Técnicas, Camino La Carrindanga km 7, Argentina
| | - Brunella Biscussi
- Instituto de Química del Sur, Departamento de Química, Universidad Nacional del Sur y Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Alem 1253, Argentina
| | - Juan Pablo Munafo
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur y Consejo Nacional de Investigaciones Científicas y Técnicas, Camino La Carrindanga km 7, Argentina
| | - Ana Paula Murray
- Instituto de Química del Sur, Departamento de Química, Universidad Nacional del Sur y Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Alem 1253, Argentina
| | - Jeremias Corradi
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur y Consejo Nacional de Investigaciones Científicas y Técnicas, Camino La Carrindanga km 7, Argentina
| | - Silvia Susana Antollini
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur y Consejo Nacional de Investigaciones Científicas y Técnicas, Camino La Carrindanga km 7, Argentina
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13
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Lipovsek M, Marcovich I, Elgoyhen AB. The Hair Cell α9α10 Nicotinic Acetylcholine Receptor: Odd Cousin in an Old Family. Front Cell Neurosci 2021; 15:785265. [PMID: 34867208 PMCID: PMC8634148 DOI: 10.3389/fncel.2021.785265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAChRs) are a subfamily of pentameric ligand-gated ion channels with members identified in most eumetazoan clades. In vertebrates, they are divided into three subgroups, according to their main tissue of expression: neuronal, muscle and hair cell nAChRs. Each receptor subtype is composed of different subunits, encoded by paralogous genes. The latest to be identified are the α9 and α10 subunits, expressed in the mechanosensory hair cells of the inner ear and the lateral line, where they mediate efferent modulation. α9α10 nAChRs are the most divergent amongst all nicotinic receptors, showing marked differences in their degree of sequence conservation, their expression pattern, their subunit co-assembly rules and, most importantly, their functional properties. Here, we review recent advances in the understanding of the structure and evolution of nAChRs. We discuss the functional consequences of sequence divergence and conservation, with special emphasis on the hair cell α9α10 receptor, a seemingly distant cousin of neuronal and muscle nicotinic receptors. Finally, we highlight potential links between the evolution of the octavolateral system and the extreme divergence of vertebrate α9α10 receptors.
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Affiliation(s)
- Marcela Lipovsek
- Ear Institute, Faculty of Brain Sciences, University College London, London, United Kingdom
| | - Irina Marcovich
- Departments of Otolaryngology & Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Ana Belén Elgoyhen
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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14
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Role of Receptors in Relation to Plaques and Tangles in Alzheimer's Disease Pathology. Int J Mol Sci 2021; 22:ijms222312987. [PMID: 34884789 PMCID: PMC8657621 DOI: 10.3390/ijms222312987] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/26/2021] [Accepted: 11/28/2021] [Indexed: 12/23/2022] Open
Abstract
Despite the identification of Aβ plaques and NFTs as biomarkers for Alzheimer’s disease (AD) pathology, therapeutic interventions remain elusive, with neither an absolute prophylactic nor a curative medication available to impede the progression of AD presently available. Current approaches focus on symptomatic treatments to maintain AD patients’ mental stability and behavioral symptoms by decreasing neuronal degeneration; however, the complexity of AD pathology requires a wide range of therapeutic approaches for both preventive and curative treatments. In this regard, this review summarizes the role of receptors as a potential target for treating AD and focuses on the path of major receptors which are responsible for AD progression. This review gives an overall idea centering on major receptors, their agonist and antagonist and future prospects of viral mimicry in AD pathology. This article aims to provide researchers and developers a comprehensive idea about the different receptors involved in AD pathogenesis that may lead to finding a new therapeutic strategy to treat AD.
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15
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Pursuing High-Resolution Structures of Nicotinic Acetylcholine Receptors: Lessons Learned from Five Decades. Molecules 2021; 26:molecules26195753. [PMID: 34641297 PMCID: PMC8510392 DOI: 10.3390/molecules26195753] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 09/19/2021] [Accepted: 09/20/2021] [Indexed: 01/04/2023] Open
Abstract
Since their discovery, nicotinic acetylcholine receptors (nAChRs) have been extensively studied to understand their function, as well as the consequence of alterations leading to disease states. Importantly, these receptors represent pharmacological targets to treat a number of neurological and neurodegenerative disorders. Nevertheless, their therapeutic value has been limited by the absence of high-resolution structures that allow for the design of more specific and effective drugs. This article offers a comprehensive review of five decades of research pursuing high-resolution structures of nAChRs. We provide a historical perspective, from initial structural studies to the most recent X-ray and cryogenic electron microscopy (Cryo-EM) nAChR structures. We also discuss the most relevant structural features that emerged from these studies, as well as perspectives in the field.
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16
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Christesen D, Yang YT, Chen W, Batterham P, Perry T. Loss of the Dβ1 nicotinic acetylcholine receptor subunit disrupts bursicon-driven wing expansion and diminishes adult viability in Drosophila melanogaster. Genetics 2021; 219:6320792. [PMID: 34849910 DOI: 10.1093/genetics/iyab112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 07/03/2021] [Indexed: 01/15/2023] Open
Abstract
Cholinergic signaling dominates the insect central nervous system, contributing to numerous fundamental pathways and behavioral circuits. However, we are only just beginning to uncover the diverse roles different cholinergic receptors may play. Historically, insect nicotinic acetylcholine receptors have received attention due to several subunits being key insecticide targets. More recently, there has been a focus on teasing apart the roles of these receptors, and their constituent subunits, in native signaling pathways. In this study, we use CRISPR-Cas9 genome editing to generate germline and somatic deletions of the Dβ1 nicotinic acetylcholine receptor subunit and investigate the consequences of loss of function in Drosophila melanogaster. Severe impacts on movement, male courtship, longevity, and wing expansion were found. Loss of Dβ1 was also associated with a reduction in transcript levels for the wing expansion hormone bursicon. Neuron-specific somatic deletion of Dβ1 in bursicon-producing neurons (CCAP-GAL4) was sufficient to disrupt wing expansion. Furthermore, CCAP-GAL4-specific expression of Dβ1 in a germline deletion background was sufficient to rescue the wing phenotype, pinpointing CCAP neurons as the neuronal subset requiring Dβ1 for the wing expansion pathway. Dβ1 is a known target of multiple commercially important insecticides, and the fitness costs exposed here explain why field-isolated target-site resistance has only been reported for amino acid replacements and not loss of function. This work reveals the importance of Dβ1-containing nicotinic acetylcholine receptors in CCAP neurons for robust bursicon-driven wing expansion.
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Affiliation(s)
- Danielle Christesen
- School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Ying Ting Yang
- School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Wei Chen
- School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Philip Batterham
- School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Trent Perry
- School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
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17
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Ledneczki I, Horváth A, Tapolcsányi P, Éles J, Molnár KD, Vágó I, Visegrády A, Kiss L, Szigetvári Á, Kóti J, Krámos B, Mahó S, Holm P, Kolok S, Fodor L, Thán M, Kostyalik D, Balázs O, Vastag M, Greiner I, Lévay G, Lendvai B, Némethy Z. HTS-based discovery and optimization of novel positive allosteric modulators of the α7 nicotinic acetylcholine receptor. Eur J Med Chem 2021; 222:113560. [PMID: 34111828 DOI: 10.1016/j.ejmech.2021.113560] [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: 02/26/2021] [Revised: 04/26/2021] [Accepted: 05/18/2021] [Indexed: 12/01/2022]
Abstract
HTS campaign of the corporate compound collection resulted in a novel, oxalic acid diamide scaffold of α7 nACh receptor positive allosteric modulators. During the hit expansion, several derivatives, such as 4, 11, 17 demonstrated not only high in vitro potency, but also in vivo efficacy in the mouse place recognition test. The advanced hit molecule 11 was further optimized by the elimination of the putatively mutagenic aromatic-amine building block that resulted in a novel, aminomethylindole compound family. The most balanced physico-chemical and pharmacological profile was found in case of compound 55. Docking study revealed an intersubunit binding site to be the most probable for our compounds. 55 demonstrated favorable cognitive enhancing profile not only in scopolamine-induced amnesia (place recognition test in mice) but also in natural forgetting (novel object recognition test in rats). Compound 55 was, furthermore, active in a cognitive paradigm of high translational value, namely in the rat touch screen visual discrimination test. Therefore, 55 was selected as a lead compound for further optimization. Based on the obtained favorable results, the invented aminomethylindole cluster may provide a viable approach for cognitive enhancement through positive allosteric modulation of α7 nAChRs.
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Affiliation(s)
- István Ledneczki
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary.
| | - Anita Horváth
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Pál Tapolcsányi
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - János Éles
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | | | - István Vágó
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - András Visegrády
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - László Kiss
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Áron Szigetvári
- Spectroscopic Research Department, Gedeon Richter Plc., Budapest, Hungary
| | - János Kóti
- Spectroscopic Research Department, Gedeon Richter Plc., Budapest, Hungary
| | - Balázs Krámos
- Spectroscopic Research Department, Gedeon Richter Plc., Budapest, Hungary
| | - Sándor Mahó
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | | | - Sándor Kolok
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - László Fodor
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Márta Thán
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Diána Kostyalik
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Ottilia Balázs
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Mónika Vastag
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - István Greiner
- Research Management, Gedeon Richter Plc., Budapest, Hungary
| | - György Lévay
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Balázs Lendvai
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Zsolt Némethy
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
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18
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Bregestovski PD, Ponomareva DN. Photochromic Modulation of Cys-loop
Ligand-gated Ion Channels. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021020162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Ledneczki I, Tapolcsányi P, Gábor E, Visegrády A, Vass M, Éles J, Holm P, Horváth A, Pocsai A, Mahó S, Greiner I, Krámos B, Béni Z, Kóti J, Káncz AE, Thán M, Kolok S, Laszy J, Balázs O, Bugovits G, Nagy J, Vastag M, Szájli Á, Bozó É, Lévay G, Lendvai B, Némethy Z. Discovery of novel positive allosteric modulators of the α7 nicotinic acetylcholine receptor: Scaffold hopping approach. Eur J Med Chem 2021; 214:113189. [PMID: 33540354 DOI: 10.1016/j.ejmech.2021.113189] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/08/2021] [Accepted: 01/08/2021] [Indexed: 11/26/2022]
Abstract
The paper focuses on the scaffold hopping-based discovery and characterization of novel nicotinic alpha 7 receptor positive modulator (α7 nAChR PAM) ligands around the reference molecule (A-867744). First, substantial efforts were carried out to assess the importance of the various pharmacophoric elements on the in vitro potency (SAR evaluation) by chemical modifications. Subsequently, several new derivatives with versatile, heteroaromatic central cores were synthesized and characterized. A promising, pyrazole-containing new chemotype with good physicochemical and in vitro parameters was identified. Retrospective analysis based on homology modeling was also carried out. Besides its favorable in vitro characteristics, the most advanced derivative 69 also showed in vivo efficacy in a rodent model of cognition (scopolamine-induced amnesia in the mouse place recognition test) and acceptable pharmacokinetic properties. Based on the in vivo data, the resulting molecule with advanced drug-like characteristics has the possibility to improve cognitive performance in a biologically relevant dose range, further strengthening the view of the supportive role of α7 nACh receptors in the cognitive processes.
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Affiliation(s)
- István Ledneczki
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary.
| | - Pál Tapolcsányi
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Eszter Gábor
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - András Visegrády
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary; Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Márton Vass
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - János Éles
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | | | - Anita Horváth
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Anikó Pocsai
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Sándor Mahó
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - István Greiner
- Research Management, Gedeon Richter Plc., Budapest, Hungary
| | - Balázs Krámos
- Spectroscopic Research Department, Gedeon Richter Plc., Budapest, Hungary
| | - Zoltán Béni
- Spectroscopic Research Department, Gedeon Richter Plc., Budapest, Hungary
| | - János Kóti
- Spectroscopic Research Department, Gedeon Richter Plc., Budapest, Hungary
| | - Anna E Káncz
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Márta Thán
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Sándor Kolok
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Judit Laszy
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Ottilia Balázs
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Gyula Bugovits
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - József Nagy
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Mónika Vastag
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Ágota Szájli
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Éva Bozó
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - György Lévay
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Balázs Lendvai
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Zsolt Némethy
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
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20
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McGrath-Morrow SA, Gorzkowski J, Groner JA, Rule AM, Wilson K, Tanski SE, Collaco JM, Klein JD. The Effects of Nicotine on Development. Pediatrics 2020; 145:peds.2019-1346. [PMID: 32047098 PMCID: PMC7049940 DOI: 10.1542/peds.2019-1346] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/05/2019] [Indexed: 01/08/2023] Open
Abstract
Recently, there has been a significant increase in the use of noncombustible nicotine-containing products, including electronic cigarettes (e-cigarettes). Of increasing popularity are e-cigarettes that can deliver high doses of nicotine over short periods of time. These devices have led to a rise in nicotine addiction in adolescent users who were nonsmokers. Use of noncombustible nicotine products by pregnant mothers is also increasing and can expose the developing fetus to nicotine, a known teratogen. In addition, young children are frequently exposed to secondhand and thirdhand nicotine aerosols generated by e-cigarettes, with little understanding of the effects these exposures can have on health. With the advent of these new nicotine-delivery systems, many concerns have arisen regarding the short- and long-term health effects of nicotine on childhood health during all stages of development. Although health studies on nicotine exposure alone are limited, educating policy makers and health care providers on the potential health effects of noncombustible nicotine is needed because public acceptance of these products has become so widespread. Most studies evaluating the effects of nicotine on health have been undertaken in the context of smoke exposure. Nevertheless, in vitro and in vivo preclinical studies strongly indicate that nicotine exposure alone can adversely affect the nervous, respiratory, immune, and cardiovascular systems, particularly when exposure occurs during critical developmental periods. In this review, we have included both preclinical and clinical studies to identify age-related health effects of nicotine exposure alone, examining the mechanisms underlying these effects.
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Affiliation(s)
- Sharon A. McGrath-Morrow
- Julius B. Richmond Center of Excellence, American Academy of Pediatrics, Itasca, Illinois;,Eudowood Division of Pediatric Respiratory Sciences, Department of Pediatrics, School of Medicine and
| | - Julie Gorzkowski
- Julius B. Richmond Center of Excellence, American Academy of Pediatrics, Itasca, Illinois
| | - Judith A. Groner
- Julius B. Richmond Center of Excellence, American Academy of Pediatrics, Itasca, Illinois;,Department of Pediatrics, Nationwide Children’s Hospital, Columbus, Ohio
| | - Ana M. Rule
- Julius B. Richmond Center of Excellence, American Academy of Pediatrics, Itasca, Illinois;,Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Karen Wilson
- Julius B. Richmond Center of Excellence, American Academy of Pediatrics, Itasca, Illinois;,Department of Pediatrics, Icahn School of Medicine at Mount Sinai and Kravis Children’s Hospital, New York, New York
| | - Susanne E. Tanski
- Julius B. Richmond Center of Excellence, American Academy of Pediatrics, Itasca, Illinois;,Department of Pediatrics, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire; and
| | - Joseph M. Collaco
- Julius B. Richmond Center of Excellence, American Academy of Pediatrics, Itasca, Illinois;,Eudowood Division of Pediatric Respiratory Sciences, Department of Pediatrics, School of Medicine and
| | - Jonathan D. Klein
- Julius B. Richmond Center of Excellence, American Academy of Pediatrics, Itasca, Illinois;,Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
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21
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Xue Y, He X, Yang T, Wang Y, Liu Z, Zhang G, Wang Y, Wang K, Zhang L, Zhang L. Discovery of fused heterocyclic carboxamide derivatives as novel α7-nAChR agonists: Synthesis, preliminary SAR and biological evaluation. Eur J Med Chem 2019; 182:111618. [PMID: 31434041 DOI: 10.1016/j.ejmech.2019.111618] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/10/2019] [Accepted: 08/11/2019] [Indexed: 10/26/2022]
Abstract
The α7 nicotinic acetylcholine receptor (α7 nAChR) has emerged as a promising therapeutic target for schizophrenia. In our previous work, a novel series of α7-nAChR agonists bearing scaffold of indolizine were discovered. To explore the effect of aromaticity on the activity and find more active agents, herein, fused heterocyclic carboxamide derivatives were designed and synthesized in this study. Based on the evaluation by two-electrode voltage clamp in Xenopus oocytes, 27 of the synthesized compounds showed obvious agonism of α7 nAChR. Particularly, compounds 10a and 10e showed significantly higher Emax than EVP-6124. The result illustrated the importance of aromaticity to the activity of agonism. Compound 10a, which showed EC50 of 1.88 μM and Emax of 72.4%, was further characterized comprehensively, including co-application with type II positive allosteric modulator PNU-120596, selectivity with other closely related ligand-gated ion channel, etc. The results showed that 10a showed moderate selectivity over other subtypes such as α4β2 and α3β4 nAChR. 10a evoked α7-like currents that were inhibited by MLA and enhanced in the presence of the α7 PAM PNU-120596. The analysis of binding mode and understanding of structure-activity relationship provided insights to develop more potent novel α7-nAChR agonists.
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Affiliation(s)
- Yu Xue
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, PR China.
| | - Xiaomeng He
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, PR China.
| | - Taoyi Yang
- Department of Molecular and Cellular Pharmacology, PKU-IDG/McGovern Institute for Brain Research, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, PR China
| | - Yuxi Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, PR China
| | - Zhenming Liu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, PR China
| | - Guisen Zhang
- Jiangsu Nhwa Pharmaceutical Co. Ltd, 69 Minzhu South Road, Xuzhou, Jiangsu, 221116, PR China
| | - Yanxing Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, PR China
| | - Kewei Wang
- Department of Molecular and Cellular Pharmacology, PKU-IDG/McGovern Institute for Brain Research, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, PR China.
| | - Liangren Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, PR China.
| | - Lihe Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, PR China.
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Fabiani C, Antollini SS. Alzheimer's Disease as a Membrane Disorder: Spatial Cross-Talk Among Beta-Amyloid Peptides, Nicotinic Acetylcholine Receptors and Lipid Rafts. Front Cell Neurosci 2019; 13:309. [PMID: 31379503 PMCID: PMC6657435 DOI: 10.3389/fncel.2019.00309] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/25/2019] [Indexed: 12/17/2022] Open
Abstract
Biological membranes show lateral and transverse asymmetric lipid distribution. Cholesterol (Chol) localizes in both hemilayers, but in the external one it is mostly condensed in lipid-ordered microdomains (raft domains), together with saturated phosphatidyl lipids and sphingolipids (including sphingomyelin and glycosphingolipids). Membrane asymmetries induce special membrane biophysical properties and behave as signals for several physiological and/or pathological processes. Alzheimer’s disease (AD) is associated with a perturbation in different membrane properties. Amyloid-β (Aβ) plaques and neurofibrillary tangles of tau protein together with neuroinflammation and neurodegeneration are the most characteristic cellular changes observed in this disease. The extracellular presence of Aβ peptides forming senile plaques, together with soluble oligomeric species of Aβ, are considered the major cause of the synaptic dysfunction of AD. The association between Aβ peptide and membrane lipids has been extensively studied. It has been postulated that Chol content and Chol distribution condition Aβ production and posterior accumulation in membranes and, hence, cell dysfunction. Several lines of evidence suggest that Aβ partitions in the cell membrane accumulate mostly in raft domains, the site where the cleavage of the precursor AβPP by β- and γ- secretase is also thought to occur. The main consequence of the pathogenesis of AD is the disruption of the cholinergic pathways in the cerebral cortex and in the basal forebrain. In parallel, the nicotinic acetylcholine receptor has been extensively linked to membrane properties. Since its transmembrane domain exhibits extensive contacts with the surrounding lipids, the acetylcholine receptor function is conditioned by its lipid microenvironment. The nicotinic acetylcholine receptor is present in high-density clusters in the cell membrane where it localizes mainly in lipid-ordered domains. Perturbations of sphingomyelin or cholesterol composition alter acetylcholine receptor location. Therefore, Aβ processing, Aβ partitioning, and acetylcholine receptor location and function can be manipulated by changes in membrane lipid biophysics. Understanding these mechanisms should provide insights into new therapeutic strategies for prevention and/or treatment of AD. Here, we discuss the implications of lipid-protein interactions at the cell membrane level in AD.
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Affiliation(s)
- Camila Fabiani
- Instituto de Investigaciones Bioquímicas de Bahía Blanca CONICET-UNS, Bahía Blanca, Argentina.,Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Silvia S Antollini
- Instituto de Investigaciones Bioquímicas de Bahía Blanca CONICET-UNS, Bahía Blanca, Argentina.,Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
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23
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Ma KG, Qian YH. Alpha 7 nicotinic acetylcholine receptor and its effects on Alzheimer's disease. Neuropeptides 2019; 73:96-106. [PMID: 30579679 DOI: 10.1016/j.npep.2018.12.003] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/26/2018] [Accepted: 12/16/2018] [Indexed: 01/16/2023]
Abstract
Alzheimer's disease (AD) is one of the major disabling and lethal diseases for aged individuals worldwide. To date, there are more than 10 hypotheses proposed for AD pathology. The beta-amyloid (Aβ) cascade hypothesis is the most widely accepted and proposes that the accumulation of Aβ in the brain is one potential mechanism for AD pathogenesis. Because some Aβ-overloaded patients do not have AD syndrome, this hypothesis is challenged from time to time. More recently, it has been shown that intracellular Aβ plays a key role in AD pathology. Aβ is internalized by receptors distributed on the cell membrane. Among these receptors, the alpha7 nicotinic acetylcholine receptor (α7 nAChR) has been shown to play an important role in AD. The α7 nAChR is a ligand-gated ion channel and is expressed in pivotal brain regions (e.g., the cerebral cortex and hippocampus) responsible for cognitive functions. The α7 nAChR is localized both presynaptically and postsynaptically, where it activates intracellular signaling cascades. Its agonist has been investigated in clinical studies to improve cognitive functions in AD. Although many studies have shown the importance of the α7 nAChR in AD, little is known regarding its role in AD pathology. Therefore, in the current review, we summarized the basic information regarding the structures and functions of the α7 nAChR, the distribution and expression of the α7 nAChR, and the role of the α7 nAChR in mediating Aβ internalization. We subsequently focused on introducing the comprehensive α7 nAChR related signaling pathways and how these signaling pathways are integrated with the α7 nAChR to play a role in AD. Finally, we stressed the AD therapy that targets the α7 nAChR.
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Affiliation(s)
- Kai-Ge Ma
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 Yanta West Road, Xi'an 710061, China; Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China
| | - Yi-Hua Qian
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, 76 Yanta West Road, Xi'an 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education of China, Xi'an Jiaotong University Health Science Center, 76 Yanta West Road, Xi'an 710061, China.
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24
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Design, synthesis and biological evaluation of 1,4-Diazobicylco[3.2.2]nonane derivatives as α7-Nicotinic acetylcholine receptor PET/CT imaging agents and agonists for Alzheimer's disease. Eur J Med Chem 2018; 159:255-266. [PMID: 30296684 DOI: 10.1016/j.ejmech.2018.09.064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 09/20/2018] [Accepted: 09/25/2018] [Indexed: 11/20/2022]
Abstract
α7-Nicotinic acetylcholine receptor (α7-nAChR) agonists are promising therapeutic drug candidates for treating the cognitive impairment associated with Alzheimer's disease (AD). Thus, a novel class of derivatives of 1,4-diazobicylco[3.2.2]nonane has been synthesized and evaluated as α7-nAChR ligands. Five of them displayed high binding affinity (Ki = 0.001-25 nM). In particular, the Ki of 14 was 0.0069 nM, which is superior to that of the most potent ligand that was previously reported by an order of magnitude. Four of them had high selectivity for α7-nAChRs over α4β2-nAChRs and no significant hERG (human ether-a-go-go-related gene) inhibition. Their agonist activity was also discussed preliminarily. One of the compounds, 15 (Ki = 2.98 ± 1.41 nM), was further radiolabeled with 18F to afford [18F]15 for PET imaging, which exhibited high initial brain uptake (11.60 ± 0.14%ID/g at 15 min post injection), brain/blood value (9.57 at 30 min post injection), specific labeling of α7-nAChRs and fast clearance from the brain. Blocking studies demonstrated that [18F]15 was α7-nAChR selective. In addition, micro-PET/CT imaging in normal rats further indicated that [18F]15 had obvious accumulation in the brain. Therefore, [18F]15 was proved to be a potential PET radiotracer for α7-nAChR imaging.
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25
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Liu W, Li MD. Insights Into Nicotinic Receptor Signaling in Nicotine Addiction: Implications for Prevention and Treatment. Curr Neuropharmacol 2018; 16:350-370. [PMID: 28762314 PMCID: PMC6018190 DOI: 10.2174/1570159x15666170801103009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 06/18/2017] [Accepted: 07/28/2017] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Nicotinic acetylcholine receptors (nAChRs) belong to the Cys-loop ligandgated ion-channel (LGIC) superfamily, which also includes the GABA, glycine, and serotonin receptors. Many nAChR subunits have been identified and shown to be involved in signal transduction on binding to them of either the neurotransmitter acetylcholine or exogenous ligands such as nicotine. The nAChRs are pentameric assemblies of homologous subunits surrounding a central pore that gates cation flux, and they are expressed at neuromuscular junctions throughout the nervous system. METHODS AND RESULTS Because different nAChR subunits assemble into a variety of pharmacologically distinct receptor subtypes, and different nAChRs are implicated in various physiological functions and pathophysiological conditions, nAChRs represent potential molecular targets for drug addiction and medical therapeutic research. This review intends to provide insights into recent advances in nAChR signaling, considering the subtypes and subunits of nAChRs and their roles in nicotinic cholinergic systems, including structure, diversity, functional allosteric modulation, targeted knockout mutations, and rare variations of specific subunits, and the potency and functional effects of mutations by focusing on their effects on nicotine addiction (NA) and smoking cessation (SC). Furthermore, we review the possible mechanisms of action of nAChRs in NA and SC based on our current knowledge. CONCLUSION Understanding these cellular and molecular mechanisms will lead to better translational and therapeutic operations and outcomes for the prevention and treatment of NA and other drug addictions, as well as chronic diseases, such as Alzheimer's and Parkinson's. Finally, we put forward some suggestions and recommendations for therapy and treatment of NA and other chronic diseases.
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Affiliation(s)
- Wuyi Liu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, China.,School of Biological Sciences and Food Engineering, Fuyang Normal University, Fuyang, Anuhi 236041, China
| | - Ming D Li
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University School of Medicine, Hangzhou, China.,Research Center for Air Pollution and Health, Zhejiang University, Hangzhou, China.,Institute of NeuroImmune Pharmacology, Seton Hall University, South Orange, NJ, United States
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26
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Kim YB, Sung TY, Yang HS. Factors that affect the onset of action of non-depolarizing neuromuscular blocking agents. Korean J Anesthesiol 2017; 70:500-510. [PMID: 29046769 PMCID: PMC5645582 DOI: 10.4097/kjae.2017.70.5.500] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 08/02/2017] [Indexed: 12/14/2022] Open
Abstract
Neuromuscular blockade plays an important role in the safe management of patient airways, surgical field improvement, and respiratory care. Rapid-sequence induction of anesthesia is indispensable to emergency surgery and obstetric anesthesia, and its purpose is to obtain a stable airway, adequate depth of anesthesia, and appropriate respiration within a short period of time without causing irritation or damage to the patient. There has been a continued search for new neuromuscular blocking drugs (NMBDs) with a rapid onset of action. Factors that affect the onset time include the potency of the NMBDs, the rate of NMBDs reaching the effect site, the onset time by dose control, metabolism and elimination of NMBDs, buffered diffusion to the effect site, nicotinic acetylcholine receptor subunit affinity, drugs that affect acetylcholine (ACh) production and release at the neuromuscular junction, drugs that inhibit plasma cholinesterase, presynaptic receptors responsible for ACh release at the neuromuscular junction, anesthetics or drugs that affect muscle contractility, site and methods for monitoring neuromuscular function, individual variability, and coexisting disease. NMBDs with rapid onset without major adverse events are expected in the next few years, and the development of lower potency NMBDs will continue. Anesthesiologists should be aware of the use of NMBDs in the management of anesthesia. The choice of NMBD and determination of the appropriate dosage to modulate neuromuscular blockade characteristics such as onset time and duration of neuromuscular blockade should be considered along with factors that affect the effects of the NMBDs. In this review, we discuss the factors that affect the onset time of NMBDs.
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Affiliation(s)
- Yong Beom Kim
- Department of Anesthesiology and Pain Medicine, Gil Medical Center, Gachon University College of Medicine, Incheon, Korea
| | - Tae-Yun Sung
- Department of Anesthesiology and Pain Medicine, Konyang University Hospital, Konyang University College of Medicine, Daejeon, Korea
| | - Hong Seuk Yang
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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27
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Amin J, Subbarayan MS. Orthosteric- versus allosteric-dependent activation of the GABA A receptor requires numerically distinct subunit level rearrangements. Sci Rep 2017; 7:7770. [PMID: 28798394 PMCID: PMC5552871 DOI: 10.1038/s41598-017-08031-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 07/07/2017] [Indexed: 12/05/2022] Open
Abstract
Anaesthetic molecules act on synaptic transmission via the allosteric modulation of ligand-gated chloride channels, such as hetero-oligomeric α1β2γ2 GABAA receptors. To elucidate the overall activation paradigm via allosteric versus orthosteric sites, we used highly homologous, but homo-oligomeric, ρ1 receptors that are contrastingly insensitive to anaesthetics and respond partially to several full GABA α1β2γ2 receptor agonists. Here, we coexpressed varying ratios of RNAs encoding the wild-type and the mutated ρ1 subunits, which are anaesthetic-sensitive and respond with full efficacy to partial GABA agonists, to generate distinct ensembles of receptors containing five, four, three, two, one, or zero mutated subunits. Using these experiments, we then demonstrate that, in the pentamer, three anaesthetic-sensitive ρ1 subunits are needed to impart full efficacy to the partial GABA agonists. By contrast, five anaesthetic-sensitive subunits are required for direct activation by anaesthetics alone, and only one anaesthetic-sensitive subunit is sufficient to confer the anaesthetic-dependent potentiation to the GABA current. In conclusion, our data indicate that GABA and anaesthetics holistically activate the GABAA ρ1 receptor through distinct subunit level rearrangements and suggest that in contrast to the global impact of GABA via orthosteric sites, the force of anaesthetics through allosteric sites may not propagate to the neighbouring subunits and, thus, may have only a local and limited effect on the ρ1 GABAA receptor model system.
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Affiliation(s)
- Jahanshah Amin
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, 33612, USA.
| | - Meena S Subbarayan
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, 33612, USA
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28
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Sajjanar B, Saxena S, Bisht D, Singh AK, Manjunatha Reddy GB, Singh R, Singh RP, Kumar S. Effect of nicotinic acetylcholine receptor alpha 1 (nAChRα1) peptides on rabies virus infection in neuronal cells. Neuropeptides 2016; 57:59-64. [PMID: 26656837 DOI: 10.1016/j.npep.2015.11.090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/03/2015] [Accepted: 11/26/2015] [Indexed: 12/25/2022]
Abstract
Rabies virus (RABV) is neurotropic and causes acute progressive encephalitis. Herein, we report the interaction of nAChRα1-subunit peptides with RABV and the effect of these peptides on RABV infection in cultured neuronal cells. Peptide sequences derived from torpedo, bovine, human and rats were synthesized and studied for their interactions with RABV using virus capture ELISA and peptide immunofluorescence. The results showed specific binding of the nAChRα1-subunit peptides to the RABV. In the virus adsorption assay, these peptides were found to inhibit the attachment of the RABV to the neuronal cells. The nAChRα1-subunit peptides inhibited the RABV infection and reduced viral gene expression in the cultured neuroblastoma (N2A) cells. Torpedo peptide sequence (T-32) had highest antiviral effect (IC50=14±3.01μM) compared to the other peptides studied. The results of the study indicated that nAChRα1-subunit peptides may act as receptor decoy molecules and inhibit the binding of virus to the native host cell receptors and hence may reduce viral infection.
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Affiliation(s)
- Basavaraj Sajjanar
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Bareilly 243122, Uttar Pradesh, India
| | - Shikha Saxena
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Bareilly 243122, Uttar Pradesh, India
| | - Deepika Bisht
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Bareilly 243122, Uttar Pradesh, India
| | - Arvind Kumar Singh
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Bareilly 243122, Uttar Pradesh, India
| | - G B Manjunatha Reddy
- National Institute of Veterinary Epidemiology and Disease Informatics, Bengaluru 560064, Karnataka, India
| | - Rajendra Singh
- Division of Veterinary Pathology, Indian Veterinary Research Institute, Bareilly 243122, Uttar Pradesh, India
| | - R P Singh
- Division of Biological Products, Indian Veterinary Research Institute, Bareilly 243122, Uttar Pradesh, India
| | - Satish Kumar
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Bareilly 243122, Uttar Pradesh, India.
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29
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Renda A, Penty N, Komal P, Nashmi R. Vulnerability to nicotine self-administration in adolescent mice correlates with age-specific expression of α4* nicotinic receptors. Neuropharmacology 2016; 108:49-59. [PMID: 27102349 DOI: 10.1016/j.neuropharm.2016.04.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 04/12/2016] [Accepted: 04/15/2016] [Indexed: 11/29/2022]
Abstract
The majority of smokers begin during adolescence, a developmental period with a high susceptibility to substance abuse. Adolescents are affected differently by nicotine compared to adults, with adolescents being more vulnerable to nicotine's rewarding properties. It is unknown if the age-dependent molecular composition of a younger brain contributes to a heightened susceptibility to nicotine addiction. Nicotine, the principle pharmacological component of tobacco, binds and activates nicotinic acetylcholine receptors (nAChRs) in the brain. The most prevalent is the widely expressed α4-containing (α4*) subtype which mediates reward and is strongly implicated in nicotine dependence. Exposing different age groups of mice, postnatal day (P) 44-86 days old, to a two bottle-choice oral nicotine self-administration paradigm for five days yielded age-specific consumption levels. Nicotine self-administration was elevated in the P44 group, peaked at P54-60 and was drastically lower in the P66 through P86 groups. We also quantified α4* nAChR expression via spectral confocal imaging of brain slices from α4YFP knock-in mice, in which the α4 nAChR subunit is tagged with a yellow fluorescent protein. Quantitative fluorescence revealed age-specific α4* nAChR expression in dopaminergic and GABAergic neurons of the ventral tegmental area. Receptor expression showed a strong positive correlation with daily nicotine dose, suggesting that α4* nAChR expression levels are age-specific and may contribute to the propensity to self-administer nicotine.
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Affiliation(s)
- Anthony Renda
- Department of Biology, Centre for Biomedical Research, University of Victoria, Canada
| | - Nora Penty
- Department of Biology, Centre for Biomedical Research, University of Victoria, Canada
| | - Pragya Komal
- Department of Biology, Centre for Biomedical Research, University of Victoria, Canada
| | - Raad Nashmi
- Department of Biology, Centre for Biomedical Research, University of Victoria, Canada.
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30
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Braun N, Lynagh T, Yu R, Biggin PC, Pless SA. Role of an Absolutely Conserved Tryptophan Pair in the Extracellular Domain of Cys-Loop Receptors. ACS Chem Neurosci 2016; 7:339-48. [PMID: 26764897 DOI: 10.1021/acschemneuro.5b00298] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cys-loop receptors mediate fast synaptic transmission in the nervous system, and their dysfunction is associated with a number of diseases. While some sequence variability is essential to ensure specific recognition of a chemically diverse set of ligands, other parts of the underlying amino acid sequences show a high degree of conservation, possibly to preserve the overall structural fold across the protein family. In this study, we focus on the only two absolutely conserved residues across the Cys-loop receptor family, two Trp side chains in the WXD motif of Loop D and in the WXPD motif of Loop A. Using a combination of conventional mutagenesis, unnatural amino acid incorporation, immunohistochemistry and MD simulations, we demonstrate the crucial contributions of these two Trp residues to receptor expression and function in two prototypical Cys-loop receptors, the anion-selective GlyR α1 and the cation-selective nAChR α7. Specifically, our results rule out possible electrostatic contributions of these Trp side chains and instead suggest that the overall size and shape of this aromatic pair is required in stabilizing the Cys-loop receptor extracellular domain.
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Affiliation(s)
- Nina Braun
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen 2100, Denmark
| | - Timothy Lynagh
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen 2100, Denmark
| | - Rilei Yu
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Philip C. Biggin
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Stephan A. Pless
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen 2100, Denmark
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31
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Khan MZ. A possible significant role of zinc and GPR39 zinc sensing receptor in Alzheimer disease and epilepsy. Biomed Pharmacother 2016; 79:263-72. [PMID: 27044837 DOI: 10.1016/j.biopha.2016.02.026] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 02/16/2016] [Accepted: 02/16/2016] [Indexed: 12/14/2022] Open
Abstract
Zinc the essential trace element, plays a significant role in the brain development and in the proper brain functions at every stage of life. Misbalance of zinc (Zn(2+)) ions in the central nervous system is involved in the pathogenesis of numerous neurodegenerative disorders such as Alzheimer's disease, Depression, and Epilepsy. In brain, Zn(2+) has been identified as a ligand, capable of activating and inhibiting the receptors including the NMDA-type glutamate receptors (NMDARs), GABAA receptors, nicotinic acetylcholine receptors (nAChRs), glycine receptors (glyR) and serotonin receptors (5-HT3). Recently GPR39 has been identified as a zinc-specific receptor, widely expressed in brain tissues including the frontal cortex, amygdala, and hippocampus. GPR39, when binding with Zn(2+) has shown promising therapeutic potentials. This review presents current knowledge regarding the role of GPR39 zinc sensing receptor in brain, with a focus on Alzheimer's disease and Epilepsy. Although the results are encouraging, further research is needed to clarify zinc and GPR39 role in the treatment of Alzheimer's disease and Epilepsy.
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Affiliation(s)
- Muhammad Zahid Khan
- Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China.
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32
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Bertrand D, Lee CHL, Flood D, Marger F, Donnelly-Roberts D. Therapeutic Potential of α7 Nicotinic Acetylcholine Receptors. Pharmacol Rev 2015; 67:1025-73. [DOI: 10.1124/pr.113.008581] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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33
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Oyola-Cintrón J, Caballero-Rivera D, Ballester L, Baéz-Pagán CA, Martínez HL, Vélez-Arroyo KP, Quesada O, Lasalde-Dominicci JA. Lateral diffusion, function, and expression of the slow channel congenital myasthenia syndrome αC418W nicotinic receptor mutation with changes in lipid raft components. J Biol Chem 2015; 290:26790-800. [PMID: 26354438 DOI: 10.1074/jbc.m115.678573] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Indexed: 12/18/2022] Open
Abstract
Lipid rafts, specialized membrane microdomains in the plasma membrane rich in cholesterol and sphingolipids, are hot spots for a number of important cellular processes. The novel nicotinic acetylcholine receptor (nAChR) mutation αC418W, the first lipid-exposed mutation identified in a patient that causes slow channel congenital myasthenia syndrome was shown to be cholesterol-sensitive and to accumulate in microdomains rich in the membrane raft marker protein caveolin-1. The objective of this study is to gain insight into the mechanism by which lateral segregation into specialized raft membrane microdomains regulates the activable pool of nAChRs. We performed fluorescent recovery after photobleaching (FRAP), quantitative RT-PCR, and whole cell patch clamp recordings of GFP-encoding Mus musculus nAChRs transfected into HEK 293 cells to assess the role of cholesterol and caveolin-1 (CAV-1) in the diffusion, expression, and functionality of the nAChR (WT and αC418W). Our findings support the hypothesis that a cholesterol-sensitive nAChR might reside in specialized membrane microdomains that upon cholesterol depletion become disrupted and release the cholesterol-sensitive nAChRs to the pool of activable receptors. In addition, our results in HEK 293 cells show an interdependence between CAV-1 and αC418W that could confer end plates rich in αC418W nAChRs to a susceptibility to changes in cholesterol levels that could cause adverse drug reactions to cholesterol-lowering drugs such as statins. The current work suggests that the interplay between cholesterol and CAV-1 provides the molecular basis for modulating the function and dynamics of the cholesterol-sensitive αC418W nAChR.
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Affiliation(s)
| | | | | | | | - Hernán L Martínez
- the California State University Dominguez Hills, Carson, California 90747
| | | | - Orestes Quesada
- Physical Sciences, University of Puerto Rico, Rio Piedras Campus, San Juan, Puerto Rico, 00931 and
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34
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Ihara M, Sattelle DB, Matsuda K. Probing new components (loop G and the α-α interface) of neonicotinoid binding sites on nicotinic acetylcholine receptors. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2015; 121:47-52. [PMID: 26047111 DOI: 10.1016/j.pestbp.2015.02.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 02/25/2015] [Accepted: 02/25/2015] [Indexed: 06/04/2023]
Abstract
Neonicotinoid insecticides interact with the orthosteric site on the extracellular ligand binding domain (LBD) of nicotinic acetylcholine receptors (nAChRs), typically activating the cation permeable ion channels. In nAChRs consisting of two α and three non-α subunits, LBDs contain six loops (loops A, B and C on the α subunit and loops D, E and F on the non-α subunit) which make up the orthosteric binding site at the α/non-α subunit interfaces. Recently, an additional site (loop G) on the β1 strand has been identified. Also, when the α/non-α subunit ratio is 3/2, another binding site is generated at the interface of two adjacent α subunits. Roles for loop G and the α-α interface in the interactions with neonicotinoids are discussed with reference to recent structural and physiological data.
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Affiliation(s)
- Makoto Ihara
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan.
| | - David B Sattelle
- The Wolfson Institute for Biomedical Research, Department of Medicine, University College London, Cruciform Building, Gower Street, London, WC1E 6BT, UK
| | - Kazuhiko Matsuda
- Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan.
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35
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Báez-Pagán CA, Delgado-Vélez M, Lasalde-Dominicci JA. Activation of the Macrophage α7 Nicotinic Acetylcholine Receptor and Control of Inflammation. J Neuroimmune Pharmacol 2015; 10:468-76. [PMID: 25870122 DOI: 10.1007/s11481-015-9601-5] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 03/12/2015] [Indexed: 01/03/2023]
Abstract
Inflammatory responses to stimuli are essential body defenses against foreign threats. However, uncontrolled inflammation may result in serious health problems, which can be life-threatening. The α7 nicotinic acetylcholine receptor, a ligand-gated ion channel expressed in the nervous and immune systems, has an essential role in the control of inflammation. Activation of the macrophage α7 receptor by acetylcholine, nicotine, or other agonists, selectively inhibits production of pro-inflammatory cytokines while leaving anti-inflammatory cytokines undisturbed. The neural control of this regulation pathway was discovered recently and it was named the cholinergic anti-inflammatory pathway (CAP). When afferent vagus nerve terminals are activated by cytokines or other pro-inflammatory stimuli, the message travels through the afferent vagus nerve, resulting in action potentials traveling down efferent vagus nerve fibers in a process that eventually leads to macrophage α7 activation by acetylcholine and inhibition of pro-inflammatory cytokines production. The mechanism by which activation of α7 in macrophages regulates pro-inflammatory responses is subject of intense research, and important insights have thus been made. The results suggest that activation of the macrophage α7 controls inflammation by inhibiting NF-κB nuclear translocation, and activating the JAK2/STAT3 pathway among other suggested pathways. While the α7 is well characterized as a ligand-gated ion channel in neurons, whole-cell patch clamp experiments suggest that α7's ion channel activity, defined as the translocation of ions across the membrane in response to ligands, is absent in leukocytes, and therefore, ion channel activity is generally assumed not to be required for the operation of the CAP. In this perspective, we briefly review macrophage α7 activation as it relates to the control of inflammation, and broaden the current view by providing single-channel currents as evidence that the α7 expressed in macrophages retains its ion translocation activity despite the absence of whole-cell currents. Whether this ion-translocating activity is relevant for the proper operation of the CAP or other important physiological processes remains obscure.
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Affiliation(s)
- Carlos A Báez-Pagán
- Department of Biology, University of Puerto Rico, Río Piedras Campus, PO Box 23360, San Juan, Puerto Rico, 00931,
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Schaefer N, Langlhofer G, Kluck CJ, Villmann C. Glycine receptor mouse mutants: model systems for human hyperekplexia. Br J Pharmacol 2014; 170:933-52. [PMID: 23941355 DOI: 10.1111/bph.12335] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 07/19/2013] [Accepted: 08/02/2013] [Indexed: 11/30/2022] Open
Abstract
Human hyperekplexia is a neuromotor disorder caused by disturbances in inhibitory glycine-mediated neurotransmission. Mutations in genes encoding for glycine receptor subunits or associated proteins, such as GLRA1, GLRB, GPHN and ARHGEF9, have been detected in patients suffering from hyperekplexia. Classical symptoms are exaggerated startle attacks upon unexpected acoustic or tactile stimuli, massive tremor, loss of postural control during startle and apnoea. Usually patients are treated with clonazepam, this helps to dampen the severe symptoms most probably by up-regulating GABAergic responses. However, the mechanism is not completely understood. Similar neuromotor phenotypes have been observed in mouse models that carry glycine receptor mutations. These mouse models serve as excellent tools for analysing the underlying pathomechanisms. Yet, studies in mutant mice looking for postsynaptic compensation of glycinergic dysfunction via an up-regulation in GABAA receptor numbers have failed, as expression levels were similar to those in wild-type mice. However, presynaptic adaptation mechanisms with an unusual switch from mixed GABA/glycinergic to GABAergic presynaptic terminals have been observed. Whether this presynaptic adaptation explains the improvement in symptoms or other compensation mechanisms exist is still under investigation. With the help of spontaneous glycine receptor mouse mutants, knock-in and knock-out studies, it is possible to associate behavioural changes with pharmacological differences in glycinergic inhibition. This review focuses on the structural and functional characteristics of the various mouse models used to elucidate the underlying signal transduction pathways and adaptation processes and describes a novel route that uses gene-therapeutic modulation of mutated receptors to overcome loss of function mutations.
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Affiliation(s)
- Natascha Schaefer
- Institute for Clinical Neurobiology, Julius-Maximilians-University of Würzburg, Würzburg, Germany
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Miller PS, Aricescu AR. Crystal structure of a human GABAA receptor. Nature 2014; 512:270-5. [PMID: 24909990 PMCID: PMC4167603 DOI: 10.1038/nature13293] [Citation(s) in RCA: 526] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 03/28/2014] [Indexed: 01/01/2023]
Abstract
Type-A γ-aminobutyric acid receptors (GABAARs) are the principal mediators of rapid inhibitory synaptic transmission in the human brain. A decline in GABAAR signalling triggers hyperactive neurological disorders such as insomnia, anxiety and epilepsy. Here we present the first three-dimensional structure of a GABAAR, the human β3 homopentamer, at 3 Å resolution. This structure reveals architectural elements unique to eukaryotic Cys-loop receptors, explains the mechanistic consequences of multiple human disease mutations and shows an unexpected structural role for a conserved N-linked glycan. The receptor was crystallized bound to a previously unknown agonist, benzamidine, opening a new avenue for the rational design of GABAAR modulators. The channel region forms a closed gate at the base of the pore, representative of a desensitized state. These results offer new insights into the signalling mechanisms of pentameric ligand-gated ion channels and enhance current understanding of GABAergic neurotransmission.
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Affiliation(s)
- Paul S Miller
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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Brunzell DH, McIntosh JM, Papke RL. Diverse strategies targeting α7 homomeric and α6β2* heteromeric nicotinic acetylcholine receptors for smoking cessation. Ann N Y Acad Sci 2014; 1327:27-45. [PMID: 24730978 DOI: 10.1111/nyas.12421] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Preclinical studies suggest that a diversity of nicotinic acetylcholine receptors (nAChRs) with different sensitivities to nicotine may contribute to tobacco addiction. Using rodent intravenous nicotine self-administration as a preclinical model with good predictive validity for therapeutic efficacy for tobacco cessation, investigators have identified heteromeric α6β2* and homomeric α7 nAChRs as promising novel therapeutic targets to promote smoking abstinence (*denotes possible assembly with other subunits). The data suggest that diverse strategies that target these subclasses of nAChRs, namely inhibition of α6β2* nAChRs and stimulation of α7 nAChRs, will support tobacco cessation. α6β2* nAChRs, members of the high-affinity family of β2* nAChRs, function similarly to α4β2* nAChRs, the primary target of the FDA-approved drug varenicline, but have a much more selective neuroanatomical pattern of expression in catecholaminergic nuclei. Although activation of β2* nAChRs facilitates nicotine self-administration, stimulation of α7 nAChRs appears to negatively modulate both nicotine reinforcement and β2* nAChR function in the mesolimbic dopamine system. Although challenges and caveats must be considered in the development of therapeutics that target these nAChR subpopulations, an accumulation of data suggests that α7 nAChR agonists, partial agonists, or positive allosteric modulators and α6β2* nAChR antagonists, partial agonists, or negative allosteric modulators may prove to be effective therapeutics for tobacco cessation.
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Affiliation(s)
- Darlene H Brunzell
- Department of Pharmacology and Toxicology, Interdisciplinary Neuroscience Program and Institute for Drug and Alcohol Studies, Virginia Commonwealth University School of Medicine, Richmond, Virginia
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Kishi T, Mukai T, Matsuda Y, Iwata N. Selective serotonin 3 receptor antagonist treatment for schizophrenia: meta-analysis and systematic review. Neuromolecular Med 2013; 16:61-9. [PMID: 23896722 DOI: 10.1007/s12017-013-8251-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 07/16/2013] [Indexed: 11/25/2022]
Abstract
Double-blinded, randomized, placebo-control trials of selective serotonin 3 receptor antagonists (5-HT3R-ANTs) for schizophrenia have differed in outcome. This meta-analysis tests the hypothesis that 5-HT3R-ANTs are effective for the treatment for schizophrenia. We searched PubMed, the Cochrane Library database, and PsycINFO up to June 15, 2013. We conducted a systematic review and meta-analysis of individual patient data from randomized controlled trials comparing 5-HT3R-ANTs add-on therapy with placebo. The risk ratio (RR), 95 % confidence intervals (CI), and standardized mean difference (SMD) were calculated. A random-effects model was used. Six studies (total n = 311) were identified. These included one granisetron plus risperidone study, one ondansetron plus risperidone study, one ondansetron plus haloperidol, and three tropisetron plus risperidone studies. The statistically significant effects of 5-HT3R-ANTs add-on therapy on Positive and Negative Syndrome Scale (PANSS) total scores were SMD = -1.03, CI = -1.70 to -0.36, p = 0.003 (I (2) = 82 %, 5 studies, n = 261); on negative scores were SMD = -1.10, CI = -1.82 to -0.39, p = 0.002 (I (2) = 84 %, 5 studies, n = 261); and on PANSS general scores were SMD = -0.70, CI = -1.23 to -0.17, p = 0.01 (I (2) = 73 %, 5 studies, n = 261). However, 5-HT3R-ANTs add-on therapy was not superior to placebo in PANSS positive scores (SMD = -0.12, p = 0.33). Dropout due to all cause (RR = 0.80, p = 0.50), inefficacy (RR = 0.76, p = 0.65), or adverse events (RR = 0.84, p = 0.75) was similar in both groups. Constipation occurred significantly more often with 5-HT3R-ANTs than placebo (RR = 2.05, CI = 1.07-3.91, p = 0.03, NNH = 11, p = 0.02). 5-HT3R-ANTs add-on therapy is more beneficial on the psychopathology (especially negative symptoms) than controls in patients with schizophrenia, and 5-HT3R-ANTs seem to be well-tolerated treatments.
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Affiliation(s)
- Taro Kishi
- Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, 470-1192, Japan,
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Structural analysis and ion translocation mechanisms of the muscle-type acetylcholine receptor channel. J Appl Biomater Funct Mater 2013; 11:e53-60. [PMID: 23728540 DOI: 10.5301/jabfm.5000148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2012] [Indexed: 12/13/2022] Open
Abstract
PURPOSE The aim of this work is to analyze the conformational changes in the acetylcholine receptor caused by channel opening and to investigate the electrostatic profile during ion translocation through the channel. METHODS A computational model of the human muscle-type acetylcholine receptor (AChR) was built and used to analyze channel structure and its interactions with different ions. Using the Torpedo AChR crystal structure as a homologous template, the 3D structure of the human muscle-type AChR was reconstructed. RESULTS This first model is optimized and an open structure of the channel is generated using Normal Mode Analysis in order to assess morphologic and energetic differences between open and closed structures. In addition, the issue of ion translocation is investigated in further detail. Results elucidate different aspects of the channel: channel gate structure, channel interactions with translocating ions, differences between muscle-type AChR and previous neuronal-type AChR models. CONCLUSIONS The model constructed here is ideal for further computational studies on muscle-type AChR and its pathologic mutations.
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Saligrama N, Case LK, del Rio R, Noubade R, Teuscher C. Systemic lack of canonical histamine receptor signaling results in increased resistance to autoimmune encephalomyelitis. THE JOURNAL OF IMMUNOLOGY 2013; 191:614-22. [PMID: 23772030 DOI: 10.4049/jimmunol.1203137] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Histamine (HA) is a key regulator of experimental allergic encephalomyelitis (EAE), the autoimmune model of multiple sclerosis. HA exerts its effects through four known G-protein-coupled receptors: H1, H2, H3, and H4 (histamine receptors; H(1-4)R). Using HR-deficient mice, our laboratory has demonstrated that H1R, H2R, H3R, and H4R play important roles in EAE pathogenesis, by regulating encephalitogenic T cell responses, cytokine production by APCs, blood-brain barrier permeability, and T regulatory cell activity, respectively. Histidine decarboxylase-deficient mice (HDCKO), which lack systemic HA, exhibit more severe EAE and increased Th1 effector cytokine production by splenocytes in response to myelin oligodendrocyte gp35-55. In an inverse approach, we tested the effect of depleting systemic canonical HA signaling on susceptibility to EAE by generating mice lacking all four known G-protein-coupled-HRs (H(1-4)RKO mice). In this article, we report that in contrast to HDCKO mice, H(1-4)RKO mice develop less severe EAE compared with wild-type animals. Furthermore, splenocytes from immunized H(1-4)RKO mice, compared with wild-type mice, produce a lower amount of Th1/Th17 effector cytokines. The opposing results seen between HDCKO and H1-4RKO mice suggest that HA may signal independently of H1-4R and support the existence of an alternative HAergic pathway in regulating EAE resistance. Understanding and exploiting this pathway has the potential to lead to new disease-modifying therapies in multiple sclerosis and other autoimmune and allergic diseases.
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Affiliation(s)
- Naresha Saligrama
- Department of Medicine, University of Vermont, Burlington, VT 05405, USA
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Mazurov AA, Kombo DC, Hauser TA, Miao L, Dull G, Genus JF, Fedorov NB, Benson L, Sidach S, Xiao Y, Hammond PS, James JW, Miller CH, Yohannes D. Discovery of (2S,3R)-N-[2-(Pyridin-3-ylmethyl)-1-azabicyclo[2.2.2]oct-3-yl]benzo[b]furan-2-carboxamide (TC-5619), a Selective α7 Nicotinic Acetylcholine Receptor Agonist, for the Treatment of Cognitive Disorders. J Med Chem 2012; 55:9793-809. [DOI: 10.1021/jm301048a] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anatoly A. Mazurov
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - David C. Kombo
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - Terry A. Hauser
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - Lan Miao
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - Gary Dull
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - John F. Genus
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - Nikolai B. Fedorov
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - Lisa Benson
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - Serguei Sidach
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - Yunde Xiao
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - Philip S. Hammond
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - John W. James
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - Craig H. Miller
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
| | - Daniel Yohannes
- Targacept, Inc., Winston-Salem, North
Carolina 27101-4165,
United States
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Lemoine D, Jiang R, Taly A, Chataigneau T, Specht A, Grutter T. Ligand-gated ion channels: new insights into neurological disorders and ligand recognition. Chem Rev 2012; 112:6285-318. [PMID: 22988962 DOI: 10.1021/cr3000829] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Damien Lemoine
- Laboratoire de Biophysicochimie des Récepteurs Canaux, UMR 7199 CNRS, Conception et Application de Molécules Bioactives, Faculté de Pharmacie, Université de Strasbourg , 67400 Illkirch, France
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Momi N, Kaur S, Ponnusamy MP, Kumar S, Wittel UA, Batra SK. Interplay between smoking-induced genotoxicity and altered signaling in pancreatic carcinogenesis. Carcinogenesis 2012; 33:1617-28. [PMID: 22623649 DOI: 10.1093/carcin/bgs186] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Despite continuous research efforts directed at early diagnosis and treatment of pancreatic cancer (PC), the status of patients affected by this deadly malignancy remains dismal. Its notoriety with regard to lack of early diagnosis and resistance to the current chemotherapeutics is due to accumulating signaling abnormalities. Hoarding experimental and epidemiological evidences have established a direct correlation between cigarette smoking and PC risk. The cancer initiating/promoting nature of cigarette smoke can be attributed to its various constituents including nicotine, which is the major psychoactive component, and several other toxic constituents, such as nitrosamines, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, and polycyclic aromatic hydrocarbons. These predominant smoke-constituents initiate a series of oncogenic events facilitating epigenetic alterations, self-sufficiency in growth signals, evasion of apoptosis, sustained angiogenesis, and metastasis. A better understanding of the molecular mechanisms underpinning these events is crucial for the prevention and therapeutic intervention against PC. This review presents various interconnected signal transduction cascades, the smoking-mediated genotoxicity, and genetic polymorphisms influencing the susceptibility for smoking-mediated PC development by modulating pivotal biological aspects such as cell defense/tumor suppression, inflammation, DNA repair, as well as tobacco-carcinogen metabolization. Additionally, it provides a large perspective toward tumor biology and the therapeutic approaches against PC by targeting one or several steps of smoking-mediated signaling cascades.
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Affiliation(s)
- Navneet Momi
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA
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Shan Q, Han L, Lynch JW. Distinct properties of glycine receptor β+/α- interface: unambiguously characterizing heteromeric interface reconstituted in homomeric protein. J Biol Chem 2012; 287:21244-52. [PMID: 22535951 DOI: 10.1074/jbc.m111.337741] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The glycine receptor (GlyR) exists either in homomeric α or heteromeric αβ forms. Its agonists bind at extracellular subunit interfaces. Unlike subunit interfaces from the homomeric α GlyR, subunit interfaces from the heteromeric αβ GlyR have not been characterized unambiguously because of the existence of multiple types of interface within single receptors. Here, we report that, by reconstituting β+/α- interfaces in a homomeric GlyR (αChb+a- GlyR), we were able to functionally characterize the αβ GlyR β+/α- interfaces. We found that the β+/α- interface had a higher agonist sensitivity than that of the α+/α- interface. This high sensitivity was contributed primarily by loop A. We also found that the β+/α- interface differentially modulates the agonist properties of glycine and taurine. Using voltage clamp fluorometry, we found that the conformational changes induced by glycine binding to the β+/α- interface were different from those induced by glycine binding to the α+/α- interface in the α GlyR. Moreover, the distinct conformational changes found at the β+/α- interface in the αChb+a- GlyR were also found in the heteromeric αβ GlyR, which suggests that the αChb+a- GlyR reconstitutes structural components and recapitulates functional properties, of the β+/α- interface in the heteromeric αβ GlyR. Our investigation not only provides structural and functional information about the GlyR β+/α- interface, which could direct GlyR β+/α- interface-specific drug design, but also provides a general methodology for unambiguously characterizing properties of specific protein interfaces from heteromeric proteins.
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Affiliation(s)
- Qiang Shan
- Brain and Mind Research Institute, University of Sydney, Sydney, New South Wales 2050, Australia.
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Brunzell DH. Preclinical evidence that activation of mesolimbic alpha 6 subunit containing nicotinic acetylcholine receptors supports nicotine addiction phenotype. Nicotine Tob Res 2012; 14:1258-69. [PMID: 22492084 DOI: 10.1093/ntr/nts089] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Nicotine is a major psychoactive ingredient in tobacco yet very few individuals quit smoking with the aid of nicotine replacement therapy. Targeted therapies with more selective action at nicotinic acetylcholine receptors (nAChRs) that contain a β2 subunit (β2*nAChRs; *denotes assembly with other subunits) have enjoyed significantly greater success, but exhibit potential for unwanted cardiac, gastrointestinal, and emotive side effects. DISCUSSION This literature review focuses on the preclinical evidence that suggests that subclasses of β2*nAChRs that assemble with the α6 subunit may provide an effective target for tobacco cessation. α6β2*nAChRs have a highly selective pattern of neuroanatomical expression in catecholaminergic nuclei including the ventral tegmental area and its projection regions. α6β2*nAChRs promote dopamine (DA) neuron activity and DA release in the mesolimbic dopamine system, a brain circuitry that is well-studied for its contributions to addiction behavior. A combination of genetic and pharmacological studies indicates that activation of α6β2*nAChRs is necessary and sufficient for nicotine psychostimulant effects and nicotine self-administration. α6β2*nAChRs support maintenance of nicotine use, support the conditioned reinforcing effects of drug-associated cues, and regulate nicotine withdrawal. CONCLUSIONS These data suggest that α6β2*nAChRs represent a critical pool of high affinity β2*nAChRs that regulates nicotine dependence phenotype and suggest that inhibition of these receptors may provide an effective strategy for tobacco cessation therapy.
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Affiliation(s)
- Darlene H Brunzell
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
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Nicotine-induced upregulation of native neuronal nicotinic receptors is caused by multiple mechanisms. J Neurosci 2012; 32:2227-38. [PMID: 22323734 DOI: 10.1523/jneurosci.5438-11.2012] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Nicotine causes changes in brain nicotinic acetylcholine receptors (nAChRs) during smoking that initiate addiction. Nicotine-induced upregulation is the long-lasting increase in nAChR radioligand binding sites in brain resulting from exposure. The mechanisms causing upregulation are not established. Many different mechanisms have been reported with the assumption that there is a single underlying cause. Using live rat cortical neurons, we examined for the first time how exposure and withdrawal of nicotine shape the kinetics of native α4β2-containing nAChR upregulation in real time. Upregulation kinetics demonstrates that at least two different mechanisms underlie this phenomenon. First, a transient upregulation occurs that rapidly reverses, faster than nAChR degradation, and corresponds to nAChR conformational changes as assayed by conformational-dependent, subunit-specific antibodies. Second, a long-lasting process occurs correlating with increases in nAChR numbers caused by decreased proteasomal subunit degradation. Previous radioligand binding measurements to brain tissue have measured the second process and largely missed the first. We conclude that nicotine-induced upregulation is composed of multiple processes occurring at different rates with different underlying causes.
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Zeilhofer HU, Wildner H, Yévenes GE. Fast synaptic inhibition in spinal sensory processing and pain control. Physiol Rev 2012; 92:193-235. [PMID: 22298656 DOI: 10.1152/physrev.00043.2010] [Citation(s) in RCA: 260] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The two amino acids GABA and glycine mediate fast inhibitory neurotransmission in different CNS areas and serve pivotal roles in the spinal sensory processing. Under healthy conditions, they limit the excitability of spinal terminals of primary sensory nerve fibers and of intrinsic dorsal horn neurons through pre- and postsynaptic mechanisms, and thereby facilitate the spatial and temporal discrimination of sensory stimuli. Removal of fast inhibition not only reduces the fidelity of normal sensory processing but also provokes symptoms very much reminiscent of pathological and chronic pain syndromes. This review summarizes our knowledge of the molecular bases of spinal inhibitory neurotransmission and its organization in dorsal horn sensory circuits. Particular emphasis is placed on the role and mechanisms of spinal inhibitory malfunction in inflammatory and neuropathic chronic pain syndromes.
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Abstract
Since the discovery of the major excitatory and inhibitory neurotransmitters and their receptors in the brain, many have deliberated over their likely structures and how these may relate to function. This was initially satisfied by the determination of the first amino acid sequences of the Cys-loop receptors that recognized acetylcholine, serotonin, GABA, and glycine, followed later by similar determinations for the glutamate receptors, comprising non-NMDA and NMDA subtypes. The last decade has seen a rapid advance resulting in the first structures of Cys-loop receptors, related bacterial and molluscan homologs, and glutamate receptors, determined down to atomic resolution. This now provides a basis for determining not just the complete structures of these important receptor classes, but also for understanding how various domains and residues interact during agonist binding, receptor activation, and channel opening, including allosteric modulation. This article reviews our current understanding of these mechanisms for the Cys-loop and glutamate receptor families.
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Affiliation(s)
- Trevor G Smart
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom.
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50
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Buchapudi K, Xu X, Ataian Y, Ji HF, Schulte M. Micromechanical measurement of AChBP binding for label-free drug discovery. Analyst 2012; 137:263-8. [DOI: 10.1039/c1an15734e] [Citation(s) in RCA: 11] [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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