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Yonoichi S, Hirano T, Hara Y, Ishida Y, Shoda A, Kimura M, Murata M, Mantani Y, Yokoyama T, Ikenaka Y, Hoshi N. Effects of exposure to the neonicotinoid pesticide clothianidin on mouse intestinal microbiota under unpredictable environmental stress. Toxicol Appl Pharmacol 2024; 482:116795. [PMID: 38160895 DOI: 10.1016/j.taap.2023.116795] [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: 09/01/2023] [Revised: 11/28/2023] [Accepted: 12/20/2023] [Indexed: 01/03/2024]
Abstract
Recent research has demonstrated the toxicity of neonicotinoid pesticides (NNs) in mammals through their interaction with nicotinic acetylcholine receptors (nAChRs). These effects are reported to extend to the intestinal microbiota as well. In addition, environmental stress affects the expression of nAChRs, which may alter sensitivity to NNs. In this study, we analyzed the intestinal microbiota of mice exposed to clothianidin (CLO), a type of NN, under environmental stress, and aimed to clarify the effects of such combined exposure on the intestinal microbiota. C57BL/6N male mice (9 weeks old) were subchronically administered a no-observed-adverse-effect-level (NOAEL) CLO-mixed rehydration gel for 29 days and simultaneously subjected to chronic unpredictable mild stress (CUMS). After the administration period, cecum contents were collected and analyzed by 16S rRNA sequencing for intestinal microbiota. CLO exposure alone resulted in alterations in the relative abundance of Alistipes and ASF356, which produce short-chain fatty acids. The addition of CUMS amplified these changes. On the other hand, CLO alone did not affect the relative abundance of Lactobacillus, but the abundance decreased when CUMS was added. This study revealed that the combined exposure to CLO and stress not only amplifies their individual effects on intestinal microbiota but also demonstrates combined and multifaceted toxicities.
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Affiliation(s)
- Sakura Yonoichi
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
| | - Tetsushi Hirano
- Faculty of Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
| | - Yukako Hara
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
| | - Yuya Ishida
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
| | - Asuka Shoda
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
| | - Mako Kimura
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
| | - Midori Murata
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
| | - Youhei Mantani
- Laboratory of Histophysiology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
| | - Toshifumi Yokoyama
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
| | - Yoshinori Ikenaka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan; Translational Research Unit, Veterinary Teaching Hospital, Faculty of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan; One Health Research Center, Hokkaido University, Kita 18, Nishi 9, Kita-ku, Sapporo 060-0818, Japan; Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Nobuhiko Hoshi
- Laboratory of Animal Molecular Morphology, Department of Animal Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan.
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Skok M. Universal nature of cholinergic regulation demonstrated with nicotinic acetylcholine receptors. BBA ADVANCES 2022; 2:100061. [PMID: 37082580 PMCID: PMC10074969 DOI: 10.1016/j.bbadva.2022.100061] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/30/2022] [Indexed: 11/17/2022] Open
Abstract
Mammalian nicotinic acetylcholine receptors (nAChRs) were initially discovered as ligand-gated ion channels mediating fast synaptic transmission in the neuro-muscular junctions and autonomic ganglia. They were further found to be involved in a wide range of basic biological processes within the brain and in non-excitable tissues. The present review summarizes the data obtained in our laboratory during last two decades. Investigation of autonomic ganglia with the nAChR subunit-specific antibodies was followed by identification of nAChRs in B lymphocytes, discovery of mitochondrial nAChRs and their role in mitochondrial apoptosis pathway, and revealing the role of α7 nAChRs and α7-specific antibodies in neuroinflammation-related Alzheimer disease and COVID-19. The data obtained demonstrate the involvement of nAChRs in cell survival, proliferation, cell-to-cell communication and inflammatory reaction. Together with the ability of nAChRs to function in both ionotropic and metabotropic way, these data illustrate the universal nature of cholinergic regulation mediated by nAChRs.
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Nicotinic Acetylcholine Receptor Involvement in Inflammatory Bowel Disease and Interactions with Gut Microbiota. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18031189. [PMID: 33572734 PMCID: PMC7908252 DOI: 10.3390/ijerph18031189] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/22/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022]
Abstract
The gut-brain axis describes a complex interplay between the central nervous system and organs of the gastrointestinal tract. Sensory neurons of dorsal root and nodose ganglia, neurons of the autonomic nervous system, and immune cells collect and relay information about the status of the gut to the brain. A critical component in this bi-directional communication system is the vagus nerve which is essential for coordinating the immune system’s response to the activities of commensal bacteria in the gut and to pathogenic strains and their toxins. Local control of gut function is provided by networks of neurons in the enteric nervous system also called the ‘gut-brain’. One element common to all of these gut-brain systems is the expression of nicotinic acetylcholine receptors. These ligand-gated ion channels serve myriad roles in the gut-brain axis including mediating fast synaptic transmission between autonomic pre- and postganglionic neurons, modulation of neurotransmitter release from peripheral sensory and enteric neurons, and modulation of cytokine release from immune cells. Here we review the role of nicotinic receptors in the gut-brain axis with a focus on the interplay of these receptors with the gut microbiome and their involvement in dysregulation of gut function and inflammatory bowel diseases.
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Tarasenko O, Voytenko S, Koval L, Lykhmus O, Kalashnyk O, Skok M. Unusual properties of α7 nicotinic acetylcholine receptor ion channels in B lymphocyte-derived SP-2/0 cells. Int Immunopharmacol 2020; 82:106373. [PMID: 32163855 DOI: 10.1016/j.intimp.2020.106373] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/25/2020] [Accepted: 03/02/2020] [Indexed: 12/30/2022]
Abstract
This study demonstrates the presence of α7 nicotinic acetylcholine receptors (nAChR) in B lymphocyte-derived SP-2/0 cells by means of flow cytometry and immunocytochemistry. According to lectin and sandwich ELISA, the α7 subunits expressed in SP-2/0 cells are more glycosylated compared to those expressed in the brain or normal B lymphocytes and are combined with β2 subunits. At zero and negative pipette potentials, either acetylcholine or α7-specific agonist PNU282987 stimulated the ion channel activity in SP-2/0 cells revealed by single channel patch-clamp recordings. The conductivity was within the range of 19 to 39 pS and reversal potential was between -17 mV and +28 mV, the currents were potentiated by α7-specific positive allosteric modulator PNU120596 and were partially blocked by α7-specific antagonist methyllicaconitine (MLA). However, they were oriented downwards suggesting that the channels mediated the cation outflux rather than influx. As shown by Ca2+ imaging studies, PNU282987 did not stimulate immediate Ca2+ influx into SP-2/0 cells. Instead, Ca2+ influx through Ca-release-activated channels (CRACs) was observed within minutes after either PNU282987 or MLA application. It is concluded that SP-2/0 express α7β2 nAChRs, which mediate the cation outflux under negative pipette potentials applied, possibly, due to depolarized membrane or negative surface charge formed by carbohydrate residues. In addition, α7β2 nAChRs may influence CRACs in ion-independent way.
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Affiliation(s)
| | - Sergiy Voytenko
- Bogomoletz Institute of Physiology, 4, Bogomoletz Str, 01024 Kyiv, Ukraine
| | - Lyudmyla Koval
- Palladin Institute of Biochemistry, 9, Leontovycha Str., 01030 Kyiv, Ukraine.
| | - Olena Lykhmus
- Palladin Institute of Biochemistry, 9, Leontovycha Str., 01030 Kyiv, Ukraine
| | - Olena Kalashnyk
- Palladin Institute of Biochemistry, 9, Leontovycha Str., 01030 Kyiv, Ukraine
| | - Maryna Skok
- Palladin Institute of Biochemistry, 9, Leontovycha Str., 01030 Kyiv, Ukraine.
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Teodoro R, Scheunemann M, Wenzel B, Peters D, Deuther-Conrad W, Brust P. Synthesis and radiofluorination of novel fluoren-9-one based derivatives for the imaging of α7 nicotinic acetylcholine receptor with PET. Bioorg Med Chem Lett 2018; 28:1471-1475. [PMID: 29628323 DOI: 10.1016/j.bmcl.2018.03.081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 03/29/2018] [Indexed: 12/15/2022]
Abstract
By structure-activity relationship studies on the tilorone scaffold, the 'one armed' substituted dibenzothiophenes and the fluoren-9-ones were identified as the most potential α7 nAChR ligands. While the suitability of dibenzothiophene derivatives as PET tracers is recognized, the potential of fluoren-9-ones is insufficiently investigated. We herein report on a series of fluoren-9-one based derivatives targeting α7 nAChR with compounds 8a and 8c possessing the highest affinity and selectivity. Accordingly, with [18F]8a and [18F]8c we designed and initially evaluated the first fluoren-9-one derived α7 nAChR selective PET ligands. A future application of these radioligands is facilitated by the herein presented successful implementation of fully automated radiosynthesis.
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Affiliation(s)
- Rodrigo Teodoro
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Matthias Scheunemann
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany
| | - Barbara Wenzel
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany
| | - Dan Peters
- DanPET AB, Rosenstigen 7, Malmö SE-21619, Sweden
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany
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Cuny H, Yu R, Tae HS, Kompella SN, Adams DJ. α-Conotoxins active at α3-containing nicotinic acetylcholine receptors and their molecular determinants for selective inhibition. Br J Pharmacol 2017; 175:1855-1868. [PMID: 28477355 DOI: 10.1111/bph.13852] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 04/13/2017] [Accepted: 04/24/2017] [Indexed: 01/22/2023] Open
Abstract
Neuronal α3-containing nicotinic acetylcholine receptors (nAChRs) in the peripheral nervous system (PNS) and non-neuronal tissues are implicated in a number of severe disease conditions ranging from cancer to cardiovascular diseases and chronic pain. However, despite the physiological characterization of mouse models and cell lines, the precise pathophysiology of nAChRs outside the CNS remains not well understood, in part because there is a lack of subtype-selective antagonists. α-Conotoxins isolated from cone snail venom exhibit characteristic individual selectivity profiles for nAChRs and, therefore, are excellent tools to study the determinants for nAChR-antagonist interactions. Given that human α3β4 subtype selective α-conotoxins are scarce and this is a major nAChR subtype in the PNS, the design of new peptides targeting this nAChR subtype is desirable. Recent studies using α-conotoxins RegIIA and AuIB, in combination with nAChR site-directed mutagenesis and computational modelling, have shed light onto specific nAChR residues, which determine the selectivity of the α-conotoxins for the human α3β2 and α3β4 subtypes. Publications describing the selectivity profile and binding sites of other α-conotoxins confirm that subtype-selective nAChR antagonists often work through common mechanisms by interacting with the same structural components and sites on the receptor. LINKED ARTICLES This article is part of a themed section on Nicotinic Acetylcholine Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.11/issuetoc.
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Affiliation(s)
- Hartmut Cuny
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia.,Victor Chang Cardiac Research Institute, Developmental and Stem Cell Biology Division, Sydney, NSW, Australia
| | - Rilei Yu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China.,Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia
| | - Shiva N Kompella
- Faculty of Pharmacy, University of Sydney, Sydney, NSW, Australia
| | - David J Adams
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, NSW, Australia
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7
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DUBOC H, TOLSTANOVA G, YUAN PQ, WU V, KAJI I, BIRAUD M, AKIBA Y, KAUNITZ J, MILLION M, TACHE Y, LARAUCHE M. Reduction of epithelial secretion in male rat distal colonic mucosa by bile acid receptor TGR5 agonist, INT-777: role of submucosal neurons. Neurogastroenterol Motil 2016; 28:1663-1676. [PMID: 27259385 PMCID: PMC5083223 DOI: 10.1111/nmo.12866] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/28/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND Recent evidence from rat neuron-free mucosa study suggests that the membrane bile acid receptor TGR5 decreases colonic secretion under basal and stimulated conditions. As submucosal neurons are key players in secretory processes and highly express TGR5, we investigated their role in TGR5 agonist-induced inhibition of secretion and the pathways recruited. METHODS TGR5 expression and localization were assessed in rat proximal (pC) and distal (dC) colon by qPCR and immunohistochemistry with double labeling for cholinergic neurons in whole-mount preparations. The influence of a selective (INT-777) or weak (ursodeoxycholic acid, UDCA) TGR5 agonist on colonic secretion was assessed in Ussing chambers, in dC preparation removing seromuscular ± submucosal tissues, in the presence of different inhibitors of secretion pathways. KEY RESULTS TGR5 mRNA is expressed in full thickness dC and pC and immunoreactivity is located in colonocytes and pChAT-positive neurons. Addition of INT-777, and less potently UDCA, decreased colonic secretion in seromuscular stripped dC by -58.17± 2.6%. INT-777 effect on basal secretion was reduced in neuron-free and TTX-treated mucosal-submucosal preparations. Atropine, hexamethonium, indomethacin, and L-NAME all reduced significantly INT-777's inhibitory effect while the 5-HT4 antagonist, RS-39604, and lidocaine abolished it. INT-777 inhibited stimulated colonic secretion induced by nicotine, but not cisapride, carbachol or PGE2. CONCLUSIONS & INFERENCES TGR5 activation inhibits basal and stimulated distal colonic secretion in rats by acting directly on epithelial cells and also inhibiting submucosal neurons. This could represent a counter-regulatory mechanism, at the submucosal level, of the known prosecretory effect of bile acids in the colon.
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Affiliation(s)
- Henri DUBOC
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA,DHU UNITY, Inserm UMR 1149, and Louis Mourier Hospital, Department of Gastroenterology and Hepatology, AP-HP, University Paris Diderot Sorbonne Paris Cité, Paris, France
| | - Ganna TOLSTANOVA
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA,Educational-Scientific Center “Institute of Biology” Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Pu-Qing YUAN
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Vincent WU
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Izumi KAJI
- Department of Medicine, School of Medicine, UCLA,Brentwood Biomedical Research Institute, Los Angeles, California, USA
| | - Mandy BIRAUD
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Yasutada AKIBA
- VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA,Department of Medicine, School of Medicine, UCLA,Brentwood Biomedical Research Institute, Los Angeles, California, USA
| | - Jonathan KAUNITZ
- VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA,Department of Medicine, School of Medicine, UCLA,Department of Surgery, School of Medicine, UCLA,Brentwood Biomedical Research Institute, Los Angeles, California, USA
| | - Mulugeta MILLION
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Yvette TACHE
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
| | - Muriel LARAUCHE
- CURE: Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA,VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA
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Teodoro R, Scheunemann M, Deuther-Conrad W, Wenzel B, Fasoli FM, Gotti C, Kranz M, Donat CK, Patt M, Hillmer A, Zheng MQ, Peters D, Steinbach J, Sabri O, Huang Y, Brust P. A Promising PET Tracer for Imaging of α₇ Nicotinic Acetylcholine Receptors in the Brain: Design, Synthesis, and in Vivo Evaluation of a Dibenzothiophene-Based Radioligand. Molecules 2015; 20:18387-421. [PMID: 26473809 PMCID: PMC6332508 DOI: 10.3390/molecules201018387] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/25/2015] [Accepted: 09/28/2015] [Indexed: 01/22/2023] Open
Abstract
Changes in the expression of α7 nicotinic acetylcholine receptors (α7 nAChRs) in the human brain are widely assumed to be associated with neurological and neurooncological processes. Investigation of these receptors invivo depends on the availability of imaging agents such as radioactively labelled ligands applicable in positron emission tomography (PET). We report on a series of new ligands for α7 nAChRs designed by the combination of dibenzothiophene dioxide as a novel hydrogen bond acceptor functionality with diazabicyclononane as an established cationic center. To assess the structure-activity relationship (SAR) of this new basic structure, we further modified the cationic center systematically by introduction of three different piperazine-based scaffolds. Based on invitro binding affinity and selectivity, assessed by radioligand displacement studies at different rat and human nAChR subtypes and at the structurally related human 5-HT3 receptor, we selected the compound 7-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-2-fluorodibenzo-[b,d]thiophene 5,5-dioxide (10a) for radiolabeling and further evaluation invivo. Radiosynthesis of [18F]10a was optimized and transferred to an automated module. Dynamic PET imaging studies with [18F]10a in piglets and a monkey demonstrated high uptake of radioactivity in the brain, followed by washout and target-region specific accumulation under baseline conditions. Kinetic analysis of [18F]10a in pig was performed using a two-tissue compartment model with arterial-derived input function. Our initial evaluation revealed that the dibenzothiophene-based PET radioligand [18F]10a ([18F]DBT-10) has high potential to provide clinically relevant information about the expression and availability of α7 nAChR in the brain.
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Affiliation(s)
- Rodrigo Teodoro
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Matthias Scheunemann
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Barbara Wenzel
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Francesca Maria Fasoli
- Consiglio Nazionale delle Ricerche, Institute of Neuroscience, Biometra-Institute University of Milan, Via Luigi Vanvitelli 32, Milano 20129, Italy.
| | - Cecilia Gotti
- Consiglio Nazionale delle Ricerche, Institute of Neuroscience, Biometra-Institute University of Milan, Via Luigi Vanvitelli 32, Milano 20129, Italy.
| | - Mathias Kranz
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Cornelius K Donat
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Marianne Patt
- Department of Nuclear Medicine, University Hospital Leipzig, Liebigstraße 18, Leipzig 04103, Germany.
| | - Ansel Hillmer
- PET Center, Yale University, P.O. Box 208048, 801 Howard Avenue, New Haven, CT 06520-8048, USA.
| | - Ming-Qiang Zheng
- PET Center, Yale University, P.O. Box 208048, 801 Howard Avenue, New Haven, CT 06520-8048, USA.
| | - Dan Peters
- Dan PET AB, Rosenstigen 7, Malmö SE-21619, Sweden.
| | - Jörg Steinbach
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
| | - Osama Sabri
- Department of Nuclear Medicine, University Hospital Leipzig, Liebigstraße 18, Leipzig 04103, Germany.
| | - Yiyun Huang
- PET Center, Yale University, P.O. Box 208048, 801 Howard Avenue, New Haven, CT 06520-8048, USA.
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Permoserstraße 15, Leipzig 04318, Germany.
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Voytenko LP, Lushnikova IV, Savotchenko AV, Isaeva EV, Skok MV, Lykhmus OY, Patseva MA, Skibo GG. Hippocampal GABAergic interneurons coexpressing alpha7-nicotinic receptors and connexin-36 are able to improve neuronal viability under oxygen-glucose deprivation. Brain Res 2015; 1616:134-45. [PMID: 25966616 DOI: 10.1016/j.brainres.2015.04.061] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 02/10/2015] [Accepted: 04/30/2015] [Indexed: 01/09/2023]
Abstract
The hippocampal interneurons are very diverse by chemical profiles and rather inconsistent by sensitivity to CI. Some hippocampal GABAergic interneurons survive certain time after ischemia while ischemia-sensitive interneurons and pyramidal neurons are damaged. GABAergic signaling, nicotinic receptors expressing α7-subunit (α7nAChRs(+)) and connexin-36 (Cx36(+), electrotonic gapjunctions protein) contradictory modulate post-ischemic environment. We hypothesized that hippocampal ischemia-resistant GABAergic interneurons coexpressing glutamate decarboxylase-67 isoform (GAD67(+)), α7nAChRs(+), Cx36(+) are able to enhance neuronal viability. To check this hypothesis the histochemical and electrophysiological investigations have been performed using rat hippocampal organotypic culture in the condition of 30-min oxygen-glucose deprivation (OGD). Post-OGD reoxygenation (4h) revealed in CA1 pyramidal layer numerous damaged cells, decreased population spike amplitude and increased pair-pulse depression. In these conditions GAD67(+) interneurons displayed the OGD-resistance and significant increase of GABA synthesis/metabolism (GAD67-immunofluorescence, mitochondrial activity). The α7nAChRs(+) and Cx36(+) co-localizations were revealed in resistant GAD67(+) interneurons. Under OGD: GABAA-receptors (GABAARs) blockade increased cell damage and exacerbated the pair-pulse depression in CA1 pyramidal layer; α7nAChRs and Cx36-channels separate blockades sufficiently decreased cell damage while interneuronal GAD67-immunofluorescence and mitochondrial activity were similar to the control. Thus, hippocampal GABAergic interneurons co-expressing α7nAChRs and Cx36 remained resistant certain time after OGD and were able to modulate CA1 neuron survival through GABAARs, α7nAChRs and Cx36-channels activity. The enhancements of the neuronal viability together with GABA synthesis/metabolism normalization suggest cooperative neuroprotective mechanism that could be used for increase in efficiency of therapeutic strategies against post-ischemic pathology.
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Affiliation(s)
- L P Voytenko
- Department of Cytology, Bogomoletz Institute of Physiology, Kiev, Ukraine.
| | - I V Lushnikova
- Department of Cytology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - A V Savotchenko
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Ukraine
| | - E V Isaeva
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Ukraine
| | - M V Skok
- Palladin Institute of Biochemistry, Kiev, Ukraine
| | - O Yu Lykhmus
- Palladin Institute of Biochemistry, Kiev, Ukraine
| | - M A Patseva
- Department of Cytology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - G G Skibo
- Department of Cytology, Bogomoletz Institute of Physiology, Kiev, Ukraine
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Lykhmus O, Gergalova G, Zouridakis M, Tzartos S, Komisarenko S, Skok M. Inflammation decreases the level of alpha7 nicotinic acetylcholine receptors in the brain mitochondria and makes them more susceptible to apoptosis induction. Int Immunopharmacol 2015; 29:148-51. [PMID: 25887272 DOI: 10.1016/j.intimp.2015.04.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 03/06/2015] [Accepted: 04/01/2015] [Indexed: 12/11/2022]
Abstract
α7 nicotinic acetylcholine receptors (α7 nAChRs) are involved in regulating inflammatory reactions, as well as the cell viability. They are expressed in both the plasma membrane and mitochondria of eukaryotic cells. Previously we found that neuroinflammation resulted in the decrease of α7 nAChR density in the brain of mice and was accompanied by accumulation of amyloid-beta (Aβ) peptides and memory impairment. In the present paper, it is shown that inflammation induced by either regular bacterial lipopolysaccharide (LPS) injections or immunizations with α7 nAChR extracellular domain (1-208) affected also the brain cell mitochondria. Using various modifications of sandwich ELISA, we observed the decrease of α7 nAChRs and accumulation of Aβ(1-40) and Aβ(1-42) in mitochondria of immunized or LPS-treated mice compared to control ones. Mitochondria of treated mice responded with cytochrome c release to lower Ca(2+) concentrations than mitochondria of control mice and were less sensitive to its attenuation with α7 nAChR agonist PNU282987. It is concluded that inflammation decreases α7 nAChR expression in both mitochondria and cell plasma membrane and makes mitochondria more susceptible to apoptosis induction.
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Affiliation(s)
| | | | | | | | | | - Maryna Skok
- Palladin Institute of Biochemistry, Kyiv, Ukraine.
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11
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Kalashnyk O, Lykhmus O, Oliinyk O, Komisarenko S, Skok M. α7 Nicotinic acetylcholine receptor-specific antibody stimulates interleukin-6 production in human astrocytes through p38-dependent pathway. Int Immunopharmacol 2014; 23:475-9. [PMID: 25281899 DOI: 10.1016/j.intimp.2014.09.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 06/12/2014] [Accepted: 09/18/2014] [Indexed: 01/02/2023]
Abstract
α7 Nicotinic acetylcholine receptors (α7 nAChRs) are involved in regulating inflammatory cytokine production in macrophages and astrocytes. In the present paper, it is shown that α7-specific agonists PNU282987 (130nM) or choline (1.6mM) attenuated the interleukin-6 (IL-6) production stimulated by bacterial lipopolysaccharide in monocyte-derived U937 and astrocyte-derived U373 cell lines. In contrast, α7(179-190)-specific antibody, which bound to and was internalized by U373 cells, stimulated IL-6 production in p38 kinase-dependent manner in the absence of lipopolysaccharide. The antibody effect was not due to its Fc-fragment because similar capacity was found for recombinant single-chain (scFv) α7(179-190)-specific antibody selected from the gene library of healthy human subject. The data obtained allow suggesting that α7-specific antibody can provoke neuroinflammation within the brain by inducing IL-6 production in astrocytes.
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Affiliation(s)
| | | | | | | | - Maryna Skok
- Palladin Institute of Biochemistry, Kyiv, Ukraine.
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12
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Lykhmus O, Gergalova G, Koval L, Zhmak M, Komisarenko S, Skok M. Mitochondria express several nicotinic acetylcholine receptor subtypes to control various pathways of apoptosis induction. Int J Biochem Cell Biol 2014; 53:246-52. [PMID: 24880090 DOI: 10.1016/j.biocel.2014.05.030] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/07/2014] [Accepted: 05/19/2014] [Indexed: 11/18/2022]
Abstract
Nicotinic acetylcholine receptors control survival, proliferation and cytokine release in non-excitable cells. Previously we reported that α7 nicotinic receptors were present in the outer membranes of mouse liver mitochondria to regulate mitochondrial pore formation and cytochrome c release. Here we used a wide spectrum of nicotinic receptor subunit-specific antibodies to show that mitochondria express several nicotinic receptor subtypes in a tissue-specific manner: brain and liver mitochondria contain α7β2, α4β2 and less α3β2 nicotinic receptors, while mitochondria from the lung express preferentially α3β4 receptor subtype; all of them are non-covalently connected to voltage-dependent anion channels and control cytochrome c release. By using selective ligands of different nicotinic receptor subtypes (acetylcholine (1 μM) or dihydro-β-erythroidine (1 μM) for α4β2), conotoxin MII (1 nM) for α3β2, MLA (50 nM) for α7β2 and acetylcholine (10 μM) for all subtypes) and apoptogenic agents triggering different mitochondrial signaling pathways (1 μM wortmannin, 90 μM Ca(2+) or 0.5 mM H₂O₂) it was found that α7β2 receptors affect mainly PI₃K/Akt pathway, while α3β2 and α4β2 nAChRs also significantly influence CaKMII- and Src-dependent pathways. It is concluded that cholinergic regulation in mitochondria is realized through multiple nicotinic receptor subtypes, which control various pathways inducing mitochondrial type of apoptosis.
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Affiliation(s)
- Olena Lykhmus
- Palladin Institute of Biochemistry, 9, Leontovicha str., 01601 Kyiv, Ukraine
| | - Galyna Gergalova
- Palladin Institute of Biochemistry, 9, Leontovicha str., 01601 Kyiv, Ukraine
| | - Lyudmyla Koval
- Palladin Institute of Biochemistry, 9, Leontovicha str., 01601 Kyiv, Ukraine
| | - Maxim Zhmak
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 16/10, Miklukho-Maklaya str., 117997 Moscow, Russian Federation
| | - Sergiy Komisarenko
- Palladin Institute of Biochemistry, 9, Leontovicha str., 01601 Kyiv, Ukraine
| | - Maryna Skok
- Palladin Institute of Biochemistry, 9, Leontovicha str., 01601 Kyiv, Ukraine.
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13
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Gergalova G, Lykhmus O, Komisarenko S, Skok M. α7 nicotinic acetylcholine receptors control cytochrome c release from isolated mitochondria through kinase-mediated pathways. Int J Biochem Cell Biol 2014; 49:26-31. [PMID: 24412630 DOI: 10.1016/j.biocel.2014.01.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 12/11/2013] [Accepted: 01/02/2014] [Indexed: 10/25/2022]
Abstract
Nicotinic acetylcholine receptors are ligand-gated ion channels found in the plasma membrane of both excitable and non-excitable cells. Previously we reported that nicotinic receptors containing α7 subunits were present in the outer membranes of mitochondria to regulate the early apoptotic events like cytochrome c release. Here we show that signaling of mitochondrial α7 nicotinic receptors affects intramitochondrial protein kinases. Agonist of α7 nicotinic receptors PNU 282987 (30 nM) prevented the effect of phosphatidyl inositol-3-kinase inhibitor wortmannin, which stimulated cytochrome c release in isolated mouse liver mitochondria, and restored the Akt (Ser 473) phosphorylation state decreased by either 90 μM Ca(2+) or wortmannin. The effect of PNU 282987 was similar to inhibition of calcium-calmodulin-dependent kinase II (upon 90 μM Ca(2+)) or of Src kinase(s) (upon 0.5mM H2O2) and of protein kinase C. Cytochrome c release from mitochondria could be also attenuated by α7 nicotinic receptor antagonist methyllicaconitine or α7-specific antibodies. Allosteric modulator PNU 120526 (1 μM) did not improve the effect of agonist PNU 282987. Acetylcholine (1 μM) and methyllicaconitine (10nM) inhibited superoxide release from mitochondria measured according to alkalization of Ca(2+)-containing medium. It is concluded that α7 nicotinic receptors regulate mitochondrial permeability transition pore formation through ion-independent mechanism involving activation of intramitochondrial PI3K/Akt pathway and inhibition of calcium-calmodulin-dependent or Src-kinase-dependent signaling pathways.
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Affiliation(s)
- Galyna Gergalova
- Palladin Institute of Biochemistry, 9, Leontovicha Str., Kyiv 01601, Ukraine
| | - Olena Lykhmus
- Palladin Institute of Biochemistry, 9, Leontovicha Str., Kyiv 01601, Ukraine
| | - Sergiy Komisarenko
- Palladin Institute of Biochemistry, 9, Leontovicha Str., Kyiv 01601, Ukraine
| | - Maryna Skok
- Palladin Institute of Biochemistry, 9, Leontovicha Str., Kyiv 01601, Ukraine.
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14
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Improgo MRD, Scofield MD, Tapper AR, Gardner PD. The nicotinic acetylcholine receptor CHRNA5/A3/B4 gene cluster: dual role in nicotine addiction and lung cancer. Prog Neurobiol 2010; 92:212-26. [PMID: 20685379 DOI: 10.1016/j.pneurobio.2010.05.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 05/15/2010] [Accepted: 05/27/2010] [Indexed: 01/19/2023]
Abstract
More than 1 billion people around the world smoke, with 10 million cigarettes sold every minute. Cigarettes contain thousands of harmful chemicals including the psychoactive compound, nicotine. Nicotine addiction is initiated by the binding of nicotine to nicotinic acetylcholine receptors, ligand-gated cation channels activated by the endogenous neurotransmitter, acetylcholine. These receptors serve as prototypes for all ligand-gated ion channels and have been extensively studied in an attempt to elucidate their role in nicotine addiction. Many of these studies have focused on heteromeric nicotinic acetylcholine receptors containing α4 and β2 subunits and homomeric nicotinic acetylcholine receptors containing the α7 subunit, two of the most abundant subtypes expressed in the brain. Recently however, a series of linkage analyses, candidate-gene analyses and genome-wide association studies have brought attention to three other members of the nicotinic acetylcholine receptor family: the α5, α3 and β4 subunits. The genes encoding these subunits lie in a genomic cluster that contains variants associated with increased risk for several diseases including nicotine dependence and lung cancer. The underlying mechanisms for these associations have not yet been elucidated but decades of research on the nicotinic receptor gene family as well as emerging data provide insight on how these receptors may function in pathological states. Here, we review this body of work, focusing on the clustered nicotinic acetylcholine receptor genes and evaluating their role in nicotine addiction and lung cancer.
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Affiliation(s)
- Ma Reina D Improgo
- Brudnick Neuropsychiatric Research Institute, Department of Psychiatry, University of Massachusetts Medical School, 303 Belmont Street, Worcester, MA 01604, United States
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15
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Smoking and inflammatory bowel diseases: what in smoking alters the course? Int J Colorectal Dis 2010; 25:671-80. [PMID: 20333390 DOI: 10.1007/s00384-010-0925-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/25/2010] [Indexed: 02/08/2023]
Abstract
Epidemiological studies provide strong evidence to confirm the correlation between cigarette smoking and inflammatory bowel diseases. This relationship is proved to be positive in Crohn's disease and negative in ulcerative colitis. What in smoking alters the course of inflammatory bowel diseases is still a mystery. Different smoking parts have different and may be opponent actions. Smoking has dual effects. Some of its activities are, sometimes, constructive as they are working in an antagonistic manner to the mechanism of the disease, such as reducing rectal blood flow and accordingly less recruitments of inflammatory mediators to the area of inflammation, enhancement of mucosal production, and consequently, strengthening the membranes, and inhibition of pro-inflammatory mediators' liberation and activity in subjects with ulcerative colitis. Yet the outcome of smoking actions may be affected by the existence of other cofactors. Odd factors, such as shortage of zinc in subjects with Crohn's disease, may facilitate liberation of pro-inflammatory mediators and their activities and accordingly exacerbates symptoms.
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16
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Lykhmus O, Koval L, Pavlovych S, Zouridakis M, Zisimopoulou P, Tzartos S, Tsetlin V, Volpina O, Cloëz-Tayarani I, Komisarenko S, Skok M. Functional effects of antibodies against non-neuronal nicotinic acetylcholine receptors. Immunol Lett 2010; 128:68-73. [DOI: 10.1016/j.imlet.2009.11.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 11/05/2009] [Accepted: 11/13/2009] [Indexed: 01/20/2023]
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17
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Garza A, Huang LZ, Son JH, Winzer-Serhan UH. Expression of nicotinic acetylcholine receptors and subunit messenger RNAs in the enteric nervous system of the neonatal rat. Neuroscience 2008; 158:1521-9. [PMID: 19095047 DOI: 10.1016/j.neuroscience.2008.11.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 11/13/2008] [Accepted: 11/18/2008] [Indexed: 10/21/2022]
Abstract
In the enteric nervous system (ENS) excitatory nicotinic cholinergic transmission is mediated by neuronal nicotinic acetylcholine receptors (nAChR) and is critical for the regulation of gastric motility. nAChRs are ligand-gated pentameric ion channels found in the CNS and peripheral nervous system. The expression of heteromeric nAChR and receptor subunit mRNAs was investigated in the neonatal rat ENS using receptor autoradiography with the radiolabeled ligand (125)I-epibatidine, and in situ hybridization with subtype specific probes for ligand binding alpha (alpha2, alpha3, alpha4, alpha5, alpha6) and structural beta (beta2, beta3, beta4) subunits. The results showed strong nicotine sensitive binding of (125)I-epibatidine around the stomach, and small and large intestines. The binding was partially displaced by A85380, a nicotinic ligand which differentiates between different heteromeric nAChR subtypes, suggesting a mixed receptor population. Radioactive in situ hybridization detected expression of alpha3, alpha5, alpha7, beta2 and beta4 mRNA in the myenteric plexus of the stomach, and small and large intestines. In the submucosal plexus of the small and large intestines expression of alpha3, alpha5 and beta4 was found in some ganglia. There was no signal for alpha4, alpha6 and beta3 in the ENS but positive hybridization signal for alpha2 transcripts was seen in some areas of the small intestines. However, the signal was not associated with any ganglion cells. The results confirm the presence of heteromeric nAChRs in the ENS similar to those found in the peripheral nervous system, with the majority being composed of alpha3(alpha5)beta4, and a few alpha3beta2 nAChRs. In addition, homomeric alpha7 nAChRs could be present.
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Affiliation(s)
- A Garza
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University System, College Station, TX 77843-1114, USA
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18
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Combined blockade of α3β4 nicotinic acetylcholine receptors and GluR1 AMPA receptors in rats prevents kainate-induced tonic-clonic seizures. Bull Exp Biol Med 2007; 143:611-3. [DOI: 10.1007/s10517-007-0195-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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19
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Hirota CL, McKay DM. Cholinergic regulation of epithelial ion transport in the mammalian intestine. Br J Pharmacol 2006; 149:463-79. [PMID: 16981004 PMCID: PMC2014671 DOI: 10.1038/sj.bjp.0706889] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Acetylcholine (ACh) is critical in controlling epithelial ion transport and hence water movements for gut hydration. Here we review the mechanism of cholinergic control of epithelial ion transport across the mammalian intestine. The cholinergic nervous system affects basal ion flux and can evoke increased active ion transport events. Most studies rely on measuring increases in short-circuit current (ISC = active ion transport) evoked by adding ACh or cholinomimetics to intestinal tissue mounted in Ussing chambers. Despite subtle species and gut regional differences, most data indicate that, under normal circumstances, the effect of ACh on intestinal ion transport is mainly an increase in Cl- secretion due to interaction with epithelial M3 muscarinic ACh receptors (mAChRs) and, to a lesser extent, neuronal M1 mAChRs; however, AChR pharmacology has been plagued by a lack of good receptor subtype-selective compounds. Mice lacking M3 mAChRs display intact cholinergically-mediated intestinal ion transport, suggesting a possible compensatory mechanism. Inflamed tissues often display perturbations in the enteric cholinergic system and reduced intestinal ion transport responses to cholinomimetics. The mechanism(s) underlying this hyporesponsiveness are not fully defined. Inflammation-evoked loss of mAChR-mediated control of epithelial ion transport in the mouse reveals a role for neuronal nicotinic AChRs, representing a hitherto unappreciated braking system to limit ACh-evoked Cl- secretion. We suggest that: i) pharmacological analyses should be supported by the use of more selective compounds and supplemented with molecular biology techniques targeting specific ACh receptors and signalling molecules, and ii) assessment of ion transport in normal tissue must be complemented with investigations of tissues from patients or animals with intestinal disease to reveal control mechanisms that may go undetected by focusing on healthy tissue only.
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Affiliation(s)
- C L Hirota
- Department Physiology & Biophysics, University of Calgary, Calgary, AB, Canada.
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20
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Gahring LC, Rogers SW. Neuronal nicotinic acetylcholine receptor expression and function on nonneuronal cells. AAPS JOURNAL 2006; 7:E885-94. [PMID: 16594641 PMCID: PMC2750958 DOI: 10.1208/aapsj070486] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Of the thousands of proven carcinogens and toxic agents contained within a cigarette, nicotine, while being the addictive agent, is often viewed as the least harmful of these compounds. Nicotine is a lipophilic molecule whose effects on neuronal nicotinic acetylcholine receptors (nAChR) have been primarily focused on its physiologic impact within the confines of the brain and peripheral nervous system. However, recently, many studies have found neuronal nAChRs to be expressed on many different nonneuronal cell types throughout the body, where increasing evidence suggests they have important roles in determining the consequences of nicotine use on multiple organs systems and diseases as diverse as ulcerative colitis, chronic pulmonary obstructive disease, and diabetes, as well as the neurologic disorders of Parkinson's and Alzheimer's disease. This review highlights current evidence for the expression of peripheral nAChRs in cells other than neurons and how they participate in fundamental processes, such as inflammation. Understanding these processes may offer novel therapeutic strategies to approach inflammatory diseases, as well as precautions in the design of interventional drugs.
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Affiliation(s)
- Lorise C Gahring
- Geriatric Research Education and Clinical Center, Salt Lake City VAMC, Salt Lake City, Utah 84132, USA.
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21
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Wang N, Orr-Urtreger A, Chapman J, Ergün Y, Rabinowitz R, Korczyn AD. Hidden function of neuronal nicotinic acetylcholine receptor β2 subunits in ganglionic transmission: comparison to α5 and β4 subunits. J Neurol Sci 2005; 228:167-77. [PMID: 15694199 DOI: 10.1016/j.jns.2004.11.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2004] [Revised: 11/19/2004] [Accepted: 11/22/2004] [Indexed: 10/25/2022]
Abstract
Neuronal nicotinic acetylcholine receptors (nAChR), which modulate fast excitatory postsynaptic potentials (f-EPSP), are located on both pre- and postganglionic sites in the autonomic nervous system (ANS). The receptor subunits alpha3, alpha5, alpha7, beta2 and beta4 are present in autonomic ganglia in various combinations and modulate acetylcholine (ACh) transmission. In the present study, autonomic functions were systemically examined in mice lacking beta2 subunits (beta2-/-) to further understand the functional role of beta2 subunits in modulating ganglionic transmission. The results show normal autonomic functions, both under physiological conditions and in perturbed conditions, on thermoregulation, pupillary size, heart rate responses and ileal contractile reactions. This suggests that the function of beta2-containing receptors in ganglionic transmission is hidden by the predominant beta4 containing receptors and confirms previous studies which suggest that alpha3alpha5beta4 nAChRs are sufficient for autonomic transmission. On the other hand, beta2-containing receptors have only a minor function on postsynaptic responses to ACh, but may modulate ACh release presynaptically, although there is no evidence for this.
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Affiliation(s)
- Ningshan Wang
- Department of Physiology and Pharmacology, Sackler Medical School, Tel Aviv University, Ramat Aviv 69978, Israel
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22
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Koval OM, Voitenko LP, Skok MV, Lykhmus EY, Tsetlin VI, Zhmak MN, Skok VI. The beta-subunit composition of nicotinic acetylcholine receptors in the neurons of the guinea pig inferior mesenteric ganglion. Neurosci Lett 2004; 365:143-6. [PMID: 15245796 DOI: 10.1016/j.neulet.2004.04.071] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2004] [Revised: 04/09/2004] [Accepted: 04/28/2004] [Indexed: 11/22/2022]
Abstract
The antibodies against synthetic (183-192) fragments of beta2- and beta4-subunits of rat neuronal nicotinic acetylcholine receptor were used to study a beta-subunit composition of nicotinic receptors in the inferior mesenteric ganglion of the guinea pig by both immunocytochemical staining and blocking of excitatory postsynaptic potentials induced by electric stimulation of the pre-ganglionic nerve (intermesenteric trunk). The beta4-specific antibody stained 59.8 +/- 7.5% of neurons and inhibited the synaptic responses in all (n = 10) neurons studied by 25.5 +/- 1.8%. The beta2-specific antibody did not stain ganglionic neurons and did not affect the synaptic transmission. Taking into account the previously obtained data on the alpha-subunits found in this ganglion, it is concluded that the neurons of inferior mesenteric ganglion contain nicotinic receptors of alpha3(alpha5)beta4 subtypes involved in synaptic transmission through the intermesenteric tract.
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Affiliation(s)
- Olga M Koval
- Bogomoletz Institute of Physiology, 4, Bogomoletz Str., 01024 Kiev, Ukraine
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