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McLean RT, Buist E, St Clair D, Wei J. Autoantibodies against acetylcholine receptors are increased in archived serum samples from patients with schizophrenia. Schizophr Res 2024; 267:8-13. [PMID: 38508027 DOI: 10.1016/j.schres.2024.03.012] [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: 06/16/2023] [Revised: 02/19/2024] [Accepted: 03/14/2024] [Indexed: 03/22/2024]
Abstract
Previous studies have demonstrated that the levels of IgG against neurotransmitter receptors are increased in patients with schizophrenia. Genome-wide association (GWA) studies of schizophrenia confirmed that 108 loci harbouring over 300 genes were associated with schizophrenia. Although the functional implications of genetic variants are unclear, theoretical functional alterations of these genes could be replicated by the presence of autoantibodies. This study examined the levels of plasma IgG antibodies against four neurotransmitter receptors, CHRM4, GRM3, CHRNA4 and CHRNA5, using an in-house ELISA in 247 patients with schizophrenia and 344 non-psychiatric controls. Four peptides were designed based on in silico analysis with computational prediction of HLA-DRB1 restricted and B-cell epitopes. The relationship between plasma IgG levels and psychiatric symptoms, as defined by the Operational Criteria Checklist for Psychotic Illness and Affective Illness (OPCRIT), were examined. The results showed that the levels of plasma IgG against peptides derived from CHRM4 and CHRNA4 were significantly increased in patients with schizophrenia compared with control subjects, but there was no significant association of plasma IgG levels with any symptom domain or any specific symptoms. These preliminary results suggest that CHRM4 and CHRNA4 may be novel targets for autoantibody responses in schizophrenia, although the pathogenic relationship between increased serum autoantibody levels and schizophrenia symptoms remains unclear.
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Affiliation(s)
- Ryan Thomas McLean
- Institute of Health Research and Innovation, University of the Highlands and Islands, Inverness, UK.
| | - Elizabeth Buist
- Institute of Health Research and Innovation, University of the Highlands and Islands, Inverness, UK; New Craigs Hospital, Inverness, UK
| | - David St Clair
- Department of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK
| | - Jun Wei
- Institute of Health Research and Innovation, University of the Highlands and Islands, Inverness, UK
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2
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Hilscher MM, Mikulovic S, Perry S, Lundberg S, Kullander K. The alpha2 nicotinic acetylcholine receptor, a subunit with unique and selective expression in inhibitory interneurons associated with principal cells. Pharmacol Res 2023; 196:106895. [PMID: 37652281 DOI: 10.1016/j.phrs.2023.106895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 09/02/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) play crucial roles in various human disorders, with the α7, α4, α6, and α3-containing nAChR subtypes extensively studied in relation to conditions such as Alzheimer's disease, Parkinson's disease, nicotine dependence, mood disorders, and stress disorders. In contrast, the α2-nAChR subunit has received less attention due to its more restricted expression and the scarcity of specific agonists and antagonists for studying its function. Nevertheless, recent research has shed light on the unique expression pattern of the Chrna2 gene, which encodes the α2-nAChR subunit, and its involvement in distinct populations of inhibitory interneurons. This review highlights the structure, pharmacology, localization, function, and disease associations of α2-containing nAChRs and points to the unique expression pattern of the Chrna2 gene and its role in different inhibitory interneuron populations. These populations, including the oriens lacunosum moleculare (OLM) cells in the hippocampus, Martinotti cells in the neocortex, and Renshaw cells in the spinal cord, share common features and contribute to recurrent inhibitory microcircuits. Thus, the α2-nAChR subunit's unique expression pattern in specific interneuron populations and its role in recurrent inhibitory microcircuits highlight its importance in various physiological processes. Further research is necessary to uncover the comprehensive functionality of α2-containing nAChRs, delineate their specific contributions to neuronal circuits, and investigate their potential as therapeutic targets for related disorders.
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Affiliation(s)
- Markus M Hilscher
- Department of Immunology, Genetics and Pathology, Uppsala University, IGP/BMC, Box 815, 751 08 Uppsala, Sweden; Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Sanja Mikulovic
- Department of Immunology, Genetics and Pathology, Uppsala University, IGP/BMC, Box 815, 751 08 Uppsala, Sweden; Leibniz Institute for Neurobiology, Cognition & Emotion Laboratory, Magdeburg, Germany; German Center for Mental Health(DZPG), Germany
| | - Sharn Perry
- Department of Immunology, Genetics and Pathology, Uppsala University, IGP/BMC, Box 815, 751 08 Uppsala, Sweden; Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Australia
| | - Stina Lundberg
- Department of Immunology, Genetics and Pathology, Uppsala University, IGP/BMC, Box 815, 751 08 Uppsala, Sweden
| | - Klas Kullander
- Department of Immunology, Genetics and Pathology, Uppsala University, IGP/BMC, Box 815, 751 08 Uppsala, Sweden.
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3
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Nakayama M, Nishimura O, Nishimura Y, Kitaichi M, Kuraku S, Sone M, Hama C. Control of Synaptic Levels of Nicotinic Acetylcholine Receptor by the Sequestering Subunit Dα5 and Secreted Scaffold Protein Hig. J Neurosci 2023; 43:3989-4004. [PMID: 37117011 PMCID: PMC10255049 DOI: 10.1523/jneurosci.2243-21.2023] [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: 11/12/2021] [Revised: 04/05/2023] [Accepted: 04/10/2023] [Indexed: 04/30/2023] Open
Abstract
The presentation of nicotinic acetylcholine receptors (nAChRs) on synaptic membranes is crucial for generating cholinergic circuits, some of which are associated with memory function and neurodegenerative disorders. Although the physiology and structure of nAChR, a cation channel comprising five subunits, have been extensively studied, little is known about how the receptor levels in interneuronal synapses are determined and which nAChR subunits participate in the regulatory process in cooperation with synaptic cleft matrices and intracellular proteins. By a genetic screen of Drosophila, we identified mutations in the nAChR subunit Dα5 gene as suppressors that restored the mutant phenotypes of hig, which encodes a secretory matrix protein localized to cholinergic synaptic clefts in the brain. Only the loss of function of Dα5 among the 10 nAChR subunits suppressed hig mutant phenotypes in both male and female flies. Dα5 behaved as a lethal factor when Hig was defective; loss of Dα5 in hig mutants rescued lethality, upregulating Dα6 synaptic levels. By contrast, levels of Dα5, Dα6, and Dα7 subunits were all reduced in hig mutants. These three subunits have distinct properties for interaction with Hig or trafficking, as confirmed by chimeric subunit experiments. Notably, the chimeric Dα5 protein, which has the extracellular sequences that display no positive interaction with Hig, exhibited abnormal distribution and lethality even in the presence of Hig. We propose that the sequestering subunit Dα5 functions by reducing synaptic levels of nAChR through internalization, and this process is blocked by Hig, which tethers Dα5 to the synaptic cleft matrix.SIGNIFICANCE STATEMENT Because the cholinergic synapse is one of the major synapses that generate various brain functions, numerous studies have sought to reveal the physiology and structure of the nicotinic acetylcholine receptor (nAChR). However, little is known about how synaptic levels of nAChR are controlled and which nAChR subunits participate in the regulatory process in cooperation with synaptic cleft matrices. By a genetic screen of Drosophila, we identified mutations in the nAChR subunit Dα5 gene as suppressors that restored the mutant phenotypes of hig, which encodes a secretory matrix protein localized to cholinergic synaptic clefts. Our data indicate that Dα5 functions in reducing synaptic levels of nAChR, and this process is blocked by Hig, which tethers Dα5 to the synaptic cleft matrix.
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Affiliation(s)
- Minoru Nakayama
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
- Faculty of Science, Toho University, Funabashi 274-8510, Japan
| | - Osamu Nishimura
- Laboratory for Phyloinformatics, RIKEN Center for Biosystems Dynamics Research, RIKEN, Kobe 650-0047, Japan
| | - Yuhi Nishimura
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Miwa Kitaichi
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Shigehiro Kuraku
- Laboratory for Phyloinformatics, RIKEN Center for Biosystems Dynamics Research, RIKEN, Kobe 650-0047, Japan
| | - Masaki Sone
- Faculty of Science, Toho University, Funabashi 274-8510, Japan
| | - Chihiro Hama
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
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4
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Arnold E, Soler-Llavina G, Kambara K, Bertrand D. The importance of ligand gated ion channels in sleep and sleep disorders. Biochem Pharmacol 2023; 212:115532. [PMID: 37019187 DOI: 10.1016/j.bcp.2023.115532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 04/05/2023]
Abstract
On average, humans spend about 26 years of their life sleeping. Increased sleep duration and quality has been linked to reduced disease risk; however, the cellular and molecular underpinnings of sleep remain open questions. It has been known for some time that pharmacological modulation of neurotransmission in the brain can promote either sleep or wakefulness thereby providing some clues about the molecular mechanisms at play. However, the field of sleep research has developed an increasingly detailed understanding of the requisite neuronal circuitry and key neurotransmitter receptor subtypes, suggesting that it may be possible to identify next generation pharmacological interventions to treat sleep disorders within this same space. The aim of this work is to examine the latest physiological and pharmacological findings highlighting the contribution of ligand gated ion channels including the inhibitory GABAA and glycine receptors and excitatory nicotinic acetylcholine receptors and glutamate receptors in the sleep-wake cycle regulation. Overall, a better understanding of ligand gated ion channels in sleep will help determine if these highly druggable targets could facilitate a better night's sleep.
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5
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Mazzaferro S, Strikwerda JR, Sine SM. Stoichiometry-selective modulation of α4β2 nicotinic ACh receptors by divalent cations. Br J Pharmacol 2022; 179:1353-1370. [PMID: 34768309 DOI: 10.1111/bph.15723] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/11/2021] [Accepted: 10/18/2021] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND AND PURPOSE α4β2 nicotinic ACh receptors (nAChRs) comprise the most abundant class of nAChRs in the nervous system. They assemble in two stoichiometric forms, each exhibiting distinct functional and pharmacological signatures. However, whether one or both forms are modulated by calcium or magnesium has not been established. EXPERIMENTAL APPROACH To assess the functional consequences of calcium and magnesium, each stoichiometric form was expressed in clonal mammalian fibroblasts and single-channel currents were recorded in the presence of a range of ACh concentrations. KEY RESULTS In the absence of divalent cations, each stoichiometric form exhibits high unitary conductance and simple gating kinetics composed of solitary channel openings or short bursts of openings. However, in the presence of calcium and magnesium, the conductance and gating kinetics change in a stoichiometry-dependent manner. Calcium and magnesium reduce the conductance of both stoichiometric forms, with each cation producing an equivalent reduction, but the reduction is greater for the (α4)2 (β2)3 form. Moreover, divalent cations promote efficient channel opening of the (α4)3 (β2)2 stoichiometry, while minimally affecting the (α4)2 (β2)3 stoichiometry. For the (α4)3 (β2)2 stoichiometry, at high but not low ACh concentrations, calcium in synergy with magnesium promote clustering of channel openings into episodes of many openings in quick succession. CONCLUSION AND IMPLICATIONS Modulation of the α4β2 nAChR by divalent cations depends on the ACh concentration, the type of cation and the subunit stoichiometry. The functional consequences of modulation are expected to depend on the regional distributions of the stoichiometric forms and synaptic versus extrasynaptic locations of the receptors.
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Affiliation(s)
- Simone Mazzaferro
- Receptor Biology Laboratory, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - John R Strikwerda
- Receptor Biology Laboratory, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Steven M Sine
- Receptor Biology Laboratory, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.,Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.,Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
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6
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Li J, Xu Y, Peng G, Zhu K, Wu Z, Shi L, Wu G. Identification of the Nerve-Cancer Cross-Talk-Related Prognostic Gene Model in Head and Neck Squamous Cell Carcinoma. Front Oncol 2021; 11:788671. [PMID: 34912722 PMCID: PMC8666427 DOI: 10.3389/fonc.2021.788671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 11/08/2021] [Indexed: 12/24/2022] Open
Abstract
The incidence of head and neck squamous cell carcinoma (HNSC) is increasing year by year. The nerve is an important component of the tumor microenvironment, which has a wide range of cross-talk with tumor cells and immune cells, especially in highly innervated organs, such as head and neck cancer and pancreatic cancer. However, the role of cancer-nerve cross-talk-related genes (NCCGs) in HNSC is unclear. In our study, we constructed a prognostic model based on genes with prognostic value in NCCGs. We used Pearson’s correlation to analyze the relationship between NCCGs and immune infiltration, microsatellite instability, tumor mutation burden, drug sensitivity, and clinical stage. We used single-cell sequencing data to analyze the expression of genes associated with stage in different cells and explored the possible pathways affected by these genes via gene set enrichment analysis. In the TCGA-HNSC cohort, a total of 23 genes were up- or downregulated compared with normal tissues. GO and KEGG pathway analysis suggested that NCCGs are mainly concentrated in membrane potential regulation, chemical synapse, axon formation, and neuroreceptor-ligand interaction. Ten genes were identified as prognosis genes by Kaplan-Meier plotter and used as candidate genes for LASSO regression. We constructed a seven-gene prognostic model (NTRK1, L1CAM, GRIN3A, CHRNA5, CHRNA6, CHRNB4, CHRND). The model could effectively predict the 1-, 3-, and 5-year survival rates in the TCGA-HNSC cohort, and the effectiveness of the model was verified by external test data. The genes included in the model were significantly correlated with immune infiltration, microsatellite instability, tumor mutation burden, drug sensitivity, and clinical stage. Single-cell sequencing data of HNSC showed that CHRNB4 was mainly expressed in tumor cells, and multiple metabolic pathways were enriched in high CHRNB4 expression tumor cells. In summary, we used comprehensive bioinformatics analysis to construct a prognostic gene model and revealed the potential of NCCGs as therapeutic targets and prognostic biomarkers in HNSC.
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Affiliation(s)
- Jun Li
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yunhong Xu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gang Peng
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kuikui Zhu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zilong Wu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Liangliang Shi
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gang Wu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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7
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Eadaim A, Hahm ET, Justice ED, Tsunoda S. Cholinergic Synaptic Homeostasis Is Tuned by an NFAT-Mediated α7 nAChR-K v4/Shal Coupled Regulatory System. Cell Rep 2021; 32:108119. [PMID: 32905767 PMCID: PMC7521586 DOI: 10.1016/j.celrep.2020.108119] [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: 03/08/2019] [Revised: 06/23/2020] [Accepted: 08/17/2020] [Indexed: 11/26/2022] Open
Abstract
Homeostatic synaptic plasticity (HSP) involves compensatory mechanisms employed by neurons and circuits to preserve signaling when confronted with global changes in activity that may occur during physiological and pathological conditions. Cholinergic neurons, which are especially affected in some pathologies, have recently been shown to exhibit HSP mediated by nicotinic acetylcholine receptors (nAChRs). In Drosophila central neurons, pharmacological blockade of activity induces a homeostatic response mediated by the Drosophila α7 (Dα7) nAChR, which is tuned by a subsequent increase in expression of the voltage-dependent Kv4/Shal channel. Here, we show that an in vivo reduction of cholinergic signaling induces HSP mediated by Dα7 nAChRs, and this upregulation of Dα7 itself is sufficient to trigger transcriptional activation, mediated by nuclear factor of activated T cells (NFAT), of the Kv4/Shal gene, revealing a receptor-ion channel system coupled for homeostatic tuning in cholinergic neurons. Eadaim et al. show that in vivo reduction of cholinergic signaling in Drosophila neurons induces synaptic homeostasis mediated by Dα7 nAChRs. This upregulation of Dα7 induces Kv4/Shal gene expression mediated by nuclear factor of activated T cells (NFAT), revealing a receptor-ion channel system coupled for homeostatic tuning in cholinergic neurons.
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Affiliation(s)
- Abdunaser Eadaim
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Eu-Teum Hahm
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Elizabeth D Justice
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Susan Tsunoda
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
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8
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Phillips MB, Nigam A, Johnson JW. Interplay between Gating and Block of Ligand-Gated Ion Channels. Brain Sci 2020; 10:brainsci10120928. [PMID: 33271923 PMCID: PMC7760600 DOI: 10.3390/brainsci10120928] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/21/2020] [Accepted: 11/26/2020] [Indexed: 02/03/2023] Open
Abstract
Drugs that inhibit ion channel function by binding in the channel and preventing current flow, known as channel blockers, can be used as powerful tools for analysis of channel properties. Channel blockers are used to probe both the sophisticated structure and basic biophysical properties of ion channels. Gating, the mechanism that controls the opening and closing of ion channels, can be profoundly influenced by channel blocking drugs. Channel block and gating are reciprocally connected; gating controls access of channel blockers to their binding sites, and channel-blocking drugs can have profound and diverse effects on the rates of gating transitions and on the stability of channel open and closed states. This review synthesizes knowledge of the inherent intertwining of block and gating of excitatory ligand-gated ion channels, with a focus on the utility of channel blockers as analytic probes of ionotropic glutamate receptor channel function.
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Affiliation(s)
- Matthew B. Phillips
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.B.P.); (A.N.)
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Aparna Nigam
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.B.P.); (A.N.)
| | - Jon W. Johnson
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; (M.B.P.); (A.N.)
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Correspondence: ; Tel.: +1-(412)-624-4295
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9
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Zhu L, Chen L, Xu P, Lu D, Dai S, Zhong L, Han Y, Zhang M, Xiao B, Chang L, Wu Q. Genetic and molecular basis of epilepsy-related cognitive dysfunction. Epilepsy Behav 2020; 104:106848. [PMID: 32028124 DOI: 10.1016/j.yebeh.2019.106848] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/06/2019] [Accepted: 12/06/2019] [Indexed: 02/02/2023]
Abstract
Epilepsy is a common neurological disease characterized by recurrent seizures. About 70 million people were affected by epilepsy or epileptic seizures. Epilepsy is a complicated complex or symptomatic syndromes induced by structural, functional, and genetic causes. Meanwhile, several comorbidities are accompanied by epileptic seizures. Cognitive dysfunction is a long-standing complication associated with epileptic seizures, which severely impairs quality of life. Although the definitive pathogenic mechanisms underlying epilepsy-related cognitive dysfunction remain unclear, accumulating evidence indicates that multiple risk factors are probably involved in the development and progression of cognitive dysfunction in patients with epilepsy. These factors include the underlying etiology, recurrent seizures or status epilepticus, structural damage that induced secondary epilepsy, genetic variants, and molecular alterations. In this review, we summarize several theories that may explain the genetic and molecular basis of epilepsy-related cognitive dysfunction.
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Affiliation(s)
- Lin Zhu
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Lu Chen
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Puying Xu
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Di Lu
- Biomedicine Engineering Research Center, Kunming Medical University, 1168 Chun Rong West Road, Kunming, Yunnan 650500, PR China
| | - Shujuan Dai
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Lianmei Zhong
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Yanbing Han
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China
| | - Mengqi Zhang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, Hunan 410008, PR China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiang Ya Road, Changsha, Hunan 410008, PR China
| | - Lvhua Chang
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China.
| | - Qian Wu
- Department of Neurology, First Affiliated Hospital, Kunming Medical University, 295 Xi Chang Road, Kunming, Yunnan 650032, PR China.
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10
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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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11
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Deflorio C, Blanchard S, Carisì MC, Bohl D, Maskos U. Human polymorphisms in nicotinic receptors: a functional analysis in iPS-derived dopaminergic neurons. FASEB J 2016; 31:828-839. [PMID: 27856558 DOI: 10.1096/fj.201600932r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 10/31/2016] [Indexed: 11/11/2022]
Abstract
Tobacco smoking is a public health problem, with ∼5 million deaths per year, representing a heavy burden for many countries. No effective therapeutic strategies are currently available for nicotine addiction, and it is therefore crucial to understand the etiological and pathophysiological factors contributing to this addiction. The neuronal α5 nicotinic acetylcholine receptor (nAChR) subunit is critically involved in nicotine dependence. In particular, the human polymorphism α5D398N corresponds to the strongest correlation with nicotine dependence risk found to date in occidental populations, according to meta-analysis of genome-wide association studies. To understand the specific contribution of this subunit in the context of nicotine addiction, an efficient screening system for native human nAChRs is needed. We have differentiated human induced pluripotent stem (iPS) cells into midbrain dopaminergic (DA) neurons and obtained a comprehensive characterization of these neurons by quantitative RT-PCR. The functional properties of nAChRs expressed in these human DA neurons, with or without the polymorphism in the α5 subunit, were studied with the patch-clamp electrophysiological technique. Our results in human DA neurons carrying the polymorphism in the α5 subunit showed an increase in EC50, indicating that, in the presence of the polymorphism, more nicotine or acetylcholine chloride is necessary to obtain the same effect. This human cell culturing system can now be used in drug discovery approaches to screen for compounds that interact specifically with human native and polymorphic nAChRs.-Deflorio, C., Blanchard, S., Carisì, M. C., Bohl, D., Maskos, U. Human polymorphisms in nicotinic receptors: a functional analysis in iPS-derived dopaminergic neurons.
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Affiliation(s)
- Cristina Deflorio
- Unité Neurobiologie Intégrative des Systèmes Cholinergiques, Département de Neuroscience, Institut Pasteur, Paris, France
| | - Stéphane Blanchard
- Unité Neurobiologie Intégrative des Systèmes Cholinergiques, Département de Neuroscience, Institut Pasteur, Paris, France
| | - Maria Carla Carisì
- Unité Neurobiologie Intégrative des Systèmes Cholinergiques, Département de Neuroscience, Institut Pasteur, Paris, France
| | - Delphine Bohl
- Unité Neurobiologie Intégrative des Systèmes Cholinergiques, Département de Neuroscience, Institut Pasteur, Paris, France.,Institut du Cerveau et de la Moelle Epinière, INSERM Unité 1127, CNRS, UMR 7225, Université Pierre et Marie Curie, Paris, France
| | - Uwe Maskos
- Unité Neurobiologie Intégrative des Systèmes Cholinergiques, Département de Neuroscience, Institut Pasteur, Paris, France; .,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 3731, Institut Pasteur, Paris, France; and
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12
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Wu J, Liu Q, Tang P, Mikkelsen JD, Shen J, Whiteaker P, Yakel JL. Heteromeric α7β2 Nicotinic Acetylcholine Receptors in the Brain. Trends Pharmacol Sci 2016; 37:562-574. [PMID: 27179601 DOI: 10.1016/j.tips.2016.03.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/27/2016] [Accepted: 03/30/2016] [Indexed: 10/21/2022]
Abstract
The α7 nicotinic acetylcholine receptor (α7 nAChR) is highly expressed in the brain, where it maintains various neuronal functions including (but not limited to) learning and memory. In addition, the protein expression levels of α7 nAChRs are altered in various brain disorders. The classic rule governing α7 nAChR assembly in the mammalian brain was that it was assembled from five α7 subunits to form a homomeric receptor pentamer. However, emerging evidence demonstrates the presence of heteromeric α7 nAChRs in heterologously expressed systems and naturally in brain neurons, where α7 subunits are co-assembled with β2 subunits to form a novel type of α7β2 nAChR. Interestingly, the α7β2 nAChR exhibits distinctive function and pharmacology from traditional homomeric α7 nAChRs. We review recent advances in probing the distribution, function, pharmacology, pathophysiology, and stoichiometry of the heteromeric α7β2 nAChR, which have provided new insights into the understanding of a novel target of cholinergic signaling.
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Affiliation(s)
- Jie Wu
- Department of Physiology, Shantou University Medicine College, Shantou, Guangdong, China; Divisions of Neurology and Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013-4496, USA.
| | - Qiang Liu
- Divisions of Neurology and Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013-4496, USA
| | - Pei Tang
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Jens D Mikkelsen
- Neurobiology Research Unit, University Hospital Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Jianxin Shen
- Department of Physiology, Shantou University Medicine College, Shantou, Guangdong, China
| | - Paul Whiteaker
- Divisions of Neurology and Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013-4496, USA
| | - Jerrel L Yakel
- Neurobiology Laboratory, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH)/DHHS, Research Triangle Park, North Carolina 27709, USA
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Chatzidaki A, Fouillet A, Li J, Dage J, Millar NS, Sher E, Ursu D. Pharmacological Characterisation of Nicotinic Acetylcholine Receptors Expressed in Human iPSC-Derived Neurons. PLoS One 2015; 10:e0125116. [PMID: 25906356 PMCID: PMC4408108 DOI: 10.1371/journal.pone.0125116] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 03/20/2015] [Indexed: 01/21/2023] Open
Abstract
Neurons derived from human induced pluripotent stem cells (iPSCs) represent a potentially valuable tool for the characterisation of neuronal receptors and ion channels. Previous studies on iPSC-derived neuronal cells have reported the functional characterisation of a variety of receptors and ion channels, including glutamate receptors, γ-aminobutyric acid (GABA) receptors and several voltage-gated ion channels. In the present study we have examined the expression and functional properties of nicotinic acetylcholine receptors (nAChRs) in human iPSC-derived neurons. Gene expression analysis indicated the presence of transcripts encoding several nAChR subunits, with highest levels detected for α3-α7, β1, β2 and β4 subunits (encoded by CHRNA3-CHRNA7, CHRNB1, CHRNB2 and CHRNB4 genes). In addition, similarly high transcript levels were detected for the truncated dupα7 subunit transcript, encoded by the partially duplicated gene CHRFAM7A, which has been associated with psychiatric disorders such as schizophrenia. The functional properties of these nAChRs have been examined by calcium fluorescence and by patch-clamp recordings. The data obtained suggest that the majority of functional nAChRs expressed in these cells have pharmacological properties typical of α7 receptors. Large responses were induced by a selective α7 agonist (compound B), in the presence of the α7-selective positive allosteric modulator (PAM) PNU-120596, which were blocked by the α7-selective antagonist methyllycaconitine (MLA). In addition, a small proportion of the neurons express nAChRs with properties typical of heteromeric (non-α7 containing) nAChR subtypes. These cells therefore represent a great tool to advance our understanding of the properties of native human nAChRs, α7 in particular.
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Affiliation(s)
- Anna Chatzidaki
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Antoine Fouillet
- Lilly Research Centre, Eli Lilly and Company, Windlesham, Surrey, United Kingdom
| | - Jingling Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285, United States of America
| | - Jeffrey Dage
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285, United States of America
| | - Neil S. Millar
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Emanuele Sher
- Lilly Research Centre, Eli Lilly and Company, Windlesham, Surrey, United Kingdom
| | - Daniel Ursu
- Lilly Research Centre, Eli Lilly and Company, Windlesham, Surrey, United Kingdom
- * E-mail:
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14
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Conti V, Aracri P, Chiti L, Brusco S, Mari F, Marini C, Albanese M, Marchi A, Liguori C, Placidi F, Romigi A, Becchetti A, Guerrini R. Nocturnal frontal lobe epilepsy with paroxysmal arousals due to CHRNA2 loss of function. Neurology 2015; 84:1520-8. [PMID: 25770198 DOI: 10.1212/wnl.0000000000001471] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 12/29/2014] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE We assessed the mutation frequency in nicotinic acetylcholine receptor (nAChR) subunits CHRNA4, CHRNB2, and CHRNA2 in a cohort including autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) and sporadic nocturnal frontal lobe epilepsy (NFLE). Upon finding a novel mutation in CHRNA2 in a large family, we tested in vitro its functional effects. METHODS We sequenced all the coding exons and their flanking intronic regions in 150 probands (73 NFLE, 77 ADNFLE), in most of whom diagnosis had been validated by EEG recording of seizures. Upon finding a missense mutation in CHRNA2, we measured whole-cell currents in human embryonic kidney cells in both wild-type and mutant α2β4 and α2β2 nAChR subtypes stimulated with nicotine. RESULTS We found a c.889A>T (p.Ile297Phe) mutation in the proband (≈0.6% of the whole cohort) of a large ADNFLE family (1.2% of familial cases) and confirmed its segregation in all 6 living affected individuals. Video-EEG studies demonstrated sleep-related paroxysmal epileptic arousals in all mutation carriers. Oxcarbazepine treatment was effective in all. Whole-cell current density was reduced to about 40% in heterozygosity and to 0% in homozygosity, with minor effects on channel permeability and sensitivity to nicotine. CONCLUSION ADNFLE had previously been associated with CHRNA2 dysfunction in one family, in which a gain of function mutation was demonstrated. We confirm the causative role of CHRNA2 mutations in ADNFLE and demonstrate that also loss of function of α2 nAChRs may have pathogenic effects. CHRNA2 mutations are a rare cause of ADNFLE but this gene should be included in mutation screening.
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Affiliation(s)
- Valerio Conti
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Patrizia Aracri
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Laura Chiti
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Simone Brusco
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Francesco Mari
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Carla Marini
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Maria Albanese
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Angela Marchi
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Claudio Liguori
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Fabio Placidi
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Andrea Romigi
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Andrea Becchetti
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy
| | - Renzo Guerrini
- From the Pediatric Neurology and Neurogenetics Unit and Laboratories (V.C., L.C., F.M., C.M., R.G.), A. Meyer Children's Hospital-University of Florence; Department of Biotechnology and Biosciences and Center of Neuroscience (P.A., S.B., A.B.), Università di Milano-Bicocca, Milan; Neurophysiopathology Unit (M.A., A.M., C.L., F.P., A.R.), Sleep and Epilepsy Center, Department of Systems Medicine, University of Rome Tor Vergata General Hospital, Rome; IRCCS Neuromed (A.R.), Pozzilli, Isernia; and IRCCS Stella Maris Foundation (R.G.), Calambrone, Pisa, Italy.
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15
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Gill-Thind JK, Dhankher P, D'Oyley JM, Sheppard TD, Millar NS. Structurally similar allosteric modulators of α7 nicotinic acetylcholine receptors exhibit five distinct pharmacological effects. J Biol Chem 2014; 290:3552-62. [PMID: 25516597 PMCID: PMC4319022 DOI: 10.1074/jbc.m114.619221] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activation of nicotinic acetylcholine receptors (nAChRs) is associated with the binding of agonists such as acetylcholine to an extracellular site that is located at the interface between two adjacent receptor subunits. More recently, there has been considerable interest in compounds, such as positive and negative allosteric modulators (PAMs and NAMs), that are able to modulate nAChR function by binding to distinct allosteric sites. Here we examined a series of compounds differing only in methyl substitution of a single aromatic ring. This series of compounds includes a previously described α7-selective allosteric agonist, cis-cis-4-p-tolyl-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinoline-8-sulfonamide (4MP-TQS), together with all other possible combinations of methyl substitution at a phenyl ring (18 additional compounds). Studies conducted with this series of compounds have revealed five distinct pharmacological effects on α7 nAChRs. These five effects can be summarized as: 1) nondesensitizing activation (allosteric agonists), 2) potentiation associated with minimal effects on receptor desensitization (type I PAMs), 3) potentiation associated with reduced desensitization (type II PAMs), 4) noncompetitive antagonism (NAMs), and 5) compounds that have no effect on orthosteric agonist responses but block allosteric modulation (silent allosteric modulators (SAMs)). Several lines of experimental evidence are consistent with all of these compounds acting at a common, transmembrane allosteric site. Notably, all of these chemically similar compounds that have been classified as nondesensitizing allosteric agonists or as nondesensitizing (type II) PAMs are cis-cis-diastereoisomers, whereas all of the NAMs, SAMs, and type I PAMs are cis-trans-diastereoisomers. Our data illustrate the remarkable pharmacological diversity of allosteric modulators acting on nAChRs.
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Affiliation(s)
- JasKiran K Gill-Thind
- From the Department of Neuroscience, Physiology & Pharmacology, University College London, London, WC1E 6BT, United Kingdom and
| | - Persis Dhankher
- the Department of Chemistry, University College London, London, WC1H 0AJ, United Kingdom
| | - Jarryl M D'Oyley
- the Department of Chemistry, University College London, London, WC1H 0AJ, United Kingdom
| | - Tom D Sheppard
- the Department of Chemistry, University College London, London, WC1H 0AJ, United Kingdom
| | - Neil S Millar
- From the Department of Neuroscience, Physiology & Pharmacology, University College London, London, WC1E 6BT, United Kingdom and
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16
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Belfield WJ, Cole DJ, Martin IL, Payne MC, Chau PL. Constrained geometric simulation of the nicotinic acetylcholine receptor. J Mol Graph Model 2014; 52:1-10. [PMID: 24955489 DOI: 10.1016/j.jmgm.2014.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 05/01/2014] [Accepted: 05/02/2014] [Indexed: 10/25/2022]
Abstract
Constrained geometric simulations have been performed for the recently published closed-channel state of the nicotinic acetylcholine receptor. These simulations support the theory that correlated motion in the flexible β-sheet structure of the extracellular domain helps to communicate a "conformational wave", spreading from the acetylcholine binding pocket. Furthermore, we have identified key residues that act at the interface between subunits and between domains that could potentially facilitate rapid communication between the binding site and the transmembrane gate.
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Affiliation(s)
- William J Belfield
- Theory of Condensed Matter Group, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, United Kingdom
| | - Daniel J Cole
- Theory of Condensed Matter Group, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, United Kingdom; Department of Chemistry, Yale University, New Haven, CT 06520-8107, United States
| | - Ian L Martin
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
| | - Mike C Payne
- Theory of Condensed Matter Group, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, United Kingdom
| | - P-L Chau
- Bioinformatique Structurale, CNRS UMR 3528, Institut Pasteur, 75724 Paris, France.
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17
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Schaaf CP. Nicotinic acetylcholine receptors in human genetic disease. Genet Med 2014; 16:649-56. [DOI: 10.1038/gim.2014.9] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 01/13/2014] [Indexed: 01/26/2023] Open
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18
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Dash B, Lukas RJ, Li MD. A signal peptide missense mutation associated with nicotine dependence alters α2*-nicotinic acetylcholine receptor function. Neuropharmacology 2014; 79:715-25. [PMID: 24467848 DOI: 10.1016/j.neuropharm.2014.01.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 01/10/2014] [Accepted: 01/13/2014] [Indexed: 10/25/2022]
Abstract
A cytosine to thymidine (C → T) missense mutation in the signal peptide (SP) sequence (rs2472553) of the nicotinic acetylcholine receptor (nAChR) α2 subunit produces a threonine-to-isoleucine substitution (T22I) often associated with nicotine dependence (ND). We assessed effects on function of α2*-nAChR ('*'indicates presence of additional subunits) of this mutation, which could alter SP cleavage, RNA/protein secondary structure, and/or efficiency of transcription, translation, subunit assembly, receptor trafficking or cell surface expression. Two-electrode voltage clamp analyses indicate peak current responses to ACh or nicotine are decreased 2.8-5.8-fold for putative low sensitivity (LS; 10:1 ratio of α:β subunit cRNAs injected) α2β2- or α2β4-nAChR and increased for putative high sensitivity (HS; 1:10 α:β subunit ratio) α2β2- (5.7-15-fold) or α2β4- (1.9-2.2-fold) nAChR as a result of the mutation. Agonist potencies are decreased 1.6-4-fold for putative LS or HS α2(T22I)β2-nAChR or for either α2*-nAChR subtype formed in the presence of equal amounts of subunit cRNA, slightly decreased for LS α2(T22I)β4-nAChR, but increased 1.4-2.4-fold for HS α2(T22I)β4-nAChR relative to receptors containing wild-type α2 subunits. These effects suggest that the α2 subunit SP mutation generally favors formation of LS receptor isoforms. We hypothesize that lower sensitivity of human α2*-nAChR to nicotine could contribute to increased susceptibility to ND. To our knowledge this is the first report of a SP mutation having a functional effect in a member of cys-loop family of ligand-gated ion channels.
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Affiliation(s)
- Bhagirathi Dash
- Department of Psychiatry and Neurobehavioral Sciences, School of Medicine, University of Virginia, Charlottesville, VA 22911, USA
| | - Ronald J Lukas
- Division of Neurobiology, Barrow Neurological Institute, Phoenix, AZ 85013, USA
| | - Ming D Li
- Department of Psychiatry and Neurobehavioral Sciences, School of Medicine, University of Virginia, Charlottesville, VA 22911, USA.
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Scarr E, Dean B. Role of the cholinergic system in the pathology and treatment of schizophrenia. Expert Rev Neurother 2014; 9:73-86. [DOI: 10.1586/14737175.9.1.73] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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20
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Colombo SF, Mazzo F, Pistillo F, Gotti C. Biogenesis, trafficking and up-regulation of nicotinic ACh receptors. Biochem Pharmacol 2013; 86:1063-73. [DOI: 10.1016/j.bcp.2013.06.023] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 06/24/2013] [Accepted: 06/26/2013] [Indexed: 12/11/2022]
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21
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Using C. elegans to Decipher the Cellular and Molecular Mechanisms Underlying Neurodevelopmental Disorders. Mol Neurobiol 2013; 48:465-89. [DOI: 10.1007/s12035-013-8434-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 02/26/2013] [Indexed: 10/27/2022]
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22
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Nicotinic acetylcholine receptors: From basic science to therapeutics. Pharmacol Ther 2013; 137:22-54. [DOI: 10.1016/j.pharmthera.2012.08.012] [Citation(s) in RCA: 382] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 08/20/2012] [Indexed: 12/14/2022]
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23
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Maffeo C, Bhattacharya S, Yoo J, Wells D, Aksimentiev A. Modeling and simulation of ion channels. Chem Rev 2012; 112:6250-84. [PMID: 23035940 PMCID: PMC3633640 DOI: 10.1021/cr3002609] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Christopher Maffeo
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - Swati Bhattacharya
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - Jejoong Yoo
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - David Wells
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
| | - Aleksei Aksimentiev
- Department of Physics, University of Illinois, 1110 W. Green St., Urbana, IL
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Affiliation(s)
- Ortrud K Steinlein
- School of Medicine, Ludwig-Maximilians University of Munich, Munich, Germany.
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25
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Sandulenko Y, Krasavin M. Natural products as templates for bioactive compound libraries. 3*. novel heterocycles and peptidomimetics generated from anabasine by isocyanide-based multicomponent reactions. Chem Heterocycl Compd (N Y) 2012. [DOI: 10.1007/s10593-012-1033-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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26
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Ping Y, Tsunoda S. Homeostatic plasticity in Drosophila central neurons, and implications in human diseases. Fly (Austin) 2012; 6:153-7. [PMID: 22735167 DOI: 10.4161/fly.20775] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Synaptic homeostasis is a form of neuronal plasticity that stabilizes activity of neural networks. Both presynaptic and postsynaptic effects are well documented in response to activity changes. The electrical signaling machinery of individual neurons, or intrinsic properties, have also been implicated in this plasticity. How synaptic and intrinsic changes are coordinated, however, is still a puzzle. A recent study by Ping and Tsunoda shows both synaptic and intrinsic changes in Drosophila central neurons in response to prolonged inactivity. ( 1) Changes include the upregulation of Dα7 nicotinic acetylcholine receptors (nAChRs) and Shal (Kv 4) potassium channels. This work has two noteworthy findings. First, although mediated by different receptors, synaptic homeostasis in the central nervous system (CNS) is conserved across species. This is perhaps the most direct demonstration that nAChRs mediate synaptic homeostasis. Changes in the expression of nAChRs have long been noted during development, as well as during pathological conditions, such as nicotine addiction ( 2) and Alzheimer disease. ( 3) The second interesting finding is the relationship between synaptic and intrinsic plasticity: nAChRs are upregulated immediately, subsequently triggering a rapid increase in Shal K (+) channels. This novel mechanism regulates synaptic homeostasis to stabilize synaptic potentials. This study sets the stage for Drosophila central neurons as a model for cholinergic synaptic homeostasis, its regulation and role in disease.
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Affiliation(s)
- Yong Ping
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO USA
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Kevelam SHG, Jansen FE, Binsbergen EV, Braun KPJ, Verbeek NE, Lindhout D, Poot M, Brilstra EH. Copy number variations in patients with electrical status epilepticus in sleep. J Child Neurol 2012; 27:178-82. [PMID: 21954431 DOI: 10.1177/0883073811416006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Electrical status epilepticus in sleep syndrome is the association of the electroencephalographic pattern and deficits in language or global cognitive function and behavioral problems. The etiology is often unknown, but genetic risk factors have been implicated. Array-based comparative genomic hybridization was used to identify copy number variations in 13 children with electrical status epilepticus in sleep syndrome to identify possible underlying risk factors. Seven copy number variations were detected in 4 of the 13 patients, which consisted of 6 novel gains and 1 loss, the recurrent 15q13.3 microdeletion. Two patients carried a probable pathogenic copy number variation containing a gene involved in the cholinergic pathway. Genetic aberrations in patients with electrical status epilepticus in sleep syndrome can provide an entry in the investigation of the etiology of electrical status epilepticus in sleep. However, further studies are needed to confirm our findings.
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Affiliation(s)
- Sietske H G Kevelam
- Department of Medical Genetics, University Medical Center Utrecht, the Netherlands.
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Schrimpf MR, Sippy KB, Briggs CA, Anderson DJ, Li T, Ji J, Frost JM, Surowy CS, Bunnelle WH, Gopalakrishnan M, Meyer MD. SAR of α7 nicotinic receptor agonists derived from tilorone: exploration of a novel nicotinic pharmacophore. Bioorg Med Chem Lett 2012; 22:1633-8. [PMID: 22281189 DOI: 10.1016/j.bmcl.2011.12.126] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 12/22/2011] [Accepted: 12/27/2011] [Indexed: 10/14/2022]
Abstract
The well-known interferon-inducer tilorone was found to possess potent affinity for the agonist site of the α7 neuronal nicotinic receptor (K(i)=56 nM). SAR investigations determined that both basic sidechains are essential for potent activity, however active monosubstituted derivatives can also be prepared if the flexible sidechains are replaced with conformationally rigidified cyclic amines. Analogs in which the fluorenone core is replaced with either dibenzothiophene-5,5-dioxide or xanthenone also retain potent activity.
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Affiliation(s)
- Michael R Schrimpf
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL 60064-6117, USA.
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Liao J, DeWard SJ, Madan-Khetarpal S, Surti U, Hu J. A small homozygous microdeletion of 15q13.3 including the CHRNA7 gene in a girl with a spectrum of severe neurodevelopmental features. Am J Med Genet A 2011; 155A:2795-800. [PMID: 21990074 DOI: 10.1002/ajmg.a.34237] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 07/10/2011] [Indexed: 11/08/2022]
Abstract
A broad spectrum of neurodevelopmental and psychiatric disorders with variable expressivity has been reported to be associated with 15q13.3 heterozygous microdeletions. Using oligonucleotide-based array-CGH analysis, we identified a small homozygous 15q13.3 deletion in a 6-year-old girl with significant global developmental delay, severe hypotonia, cortical visual impairment, staring spell seizure, and abnormal electroencephalogram. She inherited this deletion from both parents, each of them being a heterozygous carrier. With a minimum size of 410 kb, it is the smallest 15q13.3 homozygous microdeletion reported to date and contains only the CHRNA7 gene. By comparing the phenotype of our patient with that of the other four previously reported cases with larger homozygous or compound heterozygous deletions, we conclude that patients with homozygous deletion of 15q13.3 have consistent clinical features and loss of CHRNA7 gene alone is sufficient to cause the majority of clinical features found in these patients.
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Affiliation(s)
- Jun Liao
- Pittsburgh Cytogenetics Laboratory, Center for Medical Genetics and Genomics, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
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Pearson-Fuhrhop KM, Cramer SC. Genetic influences on neural plasticity. PM R 2011; 2:S227-40. [PMID: 21172685 DOI: 10.1016/j.pmrj.2010.09.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Accepted: 09/13/2010] [Indexed: 01/07/2023]
Abstract
Neural plasticity refers to the capability of the brain to alter function or structure in response to a range of events and is a crucial component of both functional recovery after injury and skill learning in healthy individuals. A number of factors influence neural plasticity and recovery of function after brain injury. The current review considers the impact of genetic factors. Polymorphisms in the human genes coding for brain-derived neurotrophic factor and apolipoprotein E have been studied in the context of plasticity and stroke recovery and are discussed here in detail. Several processes involved in plasticity and stroke recovery, such as depression or pharmacotherapy effects, are modulated by other genetic polymorphisms and are also discussed. Finally, new genetic polymorphisms that have not been studied in the context of stroke are proposed as new directions for study. A better understanding of genetic influences on recovery and response to therapy might allow improved treatment after a number of forms of central nervous system injury.
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Endris V, Hackmann K, Neuhann TM, Grasshoff U, Bonin M, Haug U, Hahn G, Schallner JC, Schröck E, Tinschert S, Rappold G, Moog U. Homozygous loss of CHRNA7 on chromosome 15q13.3 causes severe encephalopathy with seizures and hypotonia. Am J Med Genet A 2011; 152A:2908-11. [PMID: 20979196 DOI: 10.1002/ajmg.a.33692] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Volker Endris
- Department of Molecular Human Genetics, Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
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Rahman S. Brain nicotinic receptors as emerging targets for drug addiction: neurobiology to translational research. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 98:349-65. [PMID: 21199776 DOI: 10.1016/b978-0-12-385506-0.00008-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Drug addiction, a chronic relapsing disorder, is a serious public health problem around the world. A growing body of preclinical and clinical evidence suggests that mammalian brain nicotinic acetylcholine receptors (nAChRs), the heterogeneous family of ion channels, play a pivotal role in drug addiction, including nicotine and alcohol dependence. As a result, there is an increasing interest in developing nAChR-based therapies for the treatment of addictive disorders. The current review summarizes the important preclinical and clinical data, demonstrating the ability of nAChR ligands to modulate nicotine and alcohol-induced biobehavioral and neurochemical changes in laboratory animals and humans. Recent studies suggest that partial agonists and antagonists at nAChRs have therapeutic potential for the management of nicotine and alcohol dependence. The complexity of nAChRs and their regulation for the development of nAChR-based drug candidates as novel pharmacotherapy for other addictive disorders will also be discussed. Taken together, this review will provide new insights into nAChR-based compounds and offer innovative translational strategies for combating drug addictive disorders.
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Affiliation(s)
- Shafiqur Rahman
- Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, Brookings, South Dakota, USA
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Espeseth T, Sneve MH, Rootwelt H, Laeng B. Nicotinic receptor gene CHRNA4 interacts with processing load in attention. PLoS One 2010; 5:e14407. [PMID: 21203548 PMCID: PMC3008676 DOI: 10.1371/journal.pone.0014407] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2010] [Accepted: 11/29/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Pharmacological studies suggest that cholinergic neurotransmission mediates increases in attentional effort in response to high processing load during attention demanding tasks [1]. METHODOLOGY/PRINCIPAL FINDINGS In the present study we tested whether individual variation in CHRNA4, a gene coding for a subcomponent in α4β2 nicotinic receptors in the human brain, interacted with processing load in multiple-object tracking (MOT) and visual search (VS). We hypothesized that the impact of genotype would increase with greater processing load in the MOT task. Similarly, we predicted that genotype would influence performance under high but not low load in the VS task. Two hundred and two healthy persons (age range = 39-77, Mean = 57.5, SD = 9.4) performed the MOT task in which twelve identical circular objects moved about the display in an independent and unpredictable manner. Two to six objects were designated as targets and the remaining objects were distracters. The same observers also performed a visual search for a target letter (i.e. X or Z) presented together with five non-targets while ignoring centrally presented distracters (i.e. X, Z, or L). Targets differed from non-targets by a unique feature in the low load condition, whereas they shared features in the high load condition. CHRNA4 genotype interacted with processing load in both tasks. Homozygotes for the T allele (N = 62) had better tracking capacity in the MOT task and identified targets faster in the high load trials of the VS task. CONCLUSION The results support the hypothesis that the cholinergic system modulates attentional effort, and that common genetic variation can be used to study the molecular biology of cognition.
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Affiliation(s)
- Thomas Espeseth
- Department of Psychology, Center for the Study of Human Cognition, University of Oslo, Oslo, Norway
- * E-mail:
| | - Markus Handal Sneve
- Department of Psychology, Center for the Study of Human Cognition, University of Oslo, Oslo, Norway
| | - Helge Rootwelt
- Department of Medical Biochemistry, Rikshospitalet, Oslo University Hospital, Oslo, Norway
| | - Bruno Laeng
- Department of Psychology, Center for the Study of Human Cognition, University of Oslo, Oslo, Norway
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Liu J, Eaton JB, Caldarone B, Lukas RJ, Kozikowski AP. Chemistry and pharmacological characterization of novel nitrogen analogues of AMOP-H-OH (Sazetidine-A, 6-[5-(azetidin-2-ylmethoxy)pyridin-3-yl]hex-5-yn-1-ol) as α4β2-nicotinic acetylcholine receptor-selective partial agonists. J Med Chem 2010; 53:6973-85. [PMID: 20822184 DOI: 10.1021/jm100765u] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In order to advance therapeutic applications of nicotinic ligands, continuing research efforts are being directed toward the identification and characterization of novel nicotinic acetylcholine receptor (nAChR) ligands that are both potent and subtype selective. Herein we report the synthesis and pharmacological evaluation of members of a new series of 3-alkoxy-5-aminopyridine derivatives that display good selectivity for the α4β2-nAChR subtype based on ligand binding and functional evaluations. The most potent ligand in this series, compound 64, showed high radioligand binding affinity and selectivity for rat α4β2-nAChR with a K(i) value of 1.2 nM and 4700-fold selectivity for α4β2- over α3β4-nAChR, and ∼100-fold selectivity for functional, high-sensitivity, human α4β2-nAChR over α3β4*-nAChR. In the mouse forced swim test, compound 64 exhibited antidepressant-like effects. Structure-activity relationship (SAR) analyses suggest that the introduction of additional substituents to the amino group present on the pyridine ring of the N-demethylated analogue of compound 17 can provide potent α4β2-nAChR-selective ligands for possible use in treatment of neurological and psychiatric disorders including depression.
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Affiliation(s)
- Jianhua Liu
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, USA
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Malysz J, Anderson DJ, Grønlien JH, Ji J, Bunnelle WH, Håkerud M, Thorin-Hagene K, Ween H, Helfrich R, Hu M, Gubbins E, Gopalakrishnan S, Puttfarcken PS, Briggs CA, Li J, Meyer MD, Dyhring T, Ahring PK, Nielsen EØ, Peters D, Timmermann DB, Gopalakrishnan M. In vitro pharmacological characterization of a novel selective alpha7 neuronal nicotinic acetylcholine receptor agonist ABT-107. J Pharmacol Exp Ther 2010; 334:863-74. [PMID: 20504915 DOI: 10.1124/jpet.110.167072] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Enhancement of alpha7 nicotinic acetylcholine receptor (nAChR) activity is considered a therapeutic approach for ameliorating cognitive deficits present in Alzheimer's disease and schizophrenia. In this study, we describe the in vitro profile of a novel selective alpha7 nAChR agonist, 5-(6-[(3R)-1-azabicyclo[2,2,2]oct-3-yloxy]pyridazin-3-yl)-1H-indole (ABT-107). ABT-107 displayed high affinity binding to alpha7 nAChRs [rat or human cortex, [(3)H](1S,4S)-2,2-dimethyl-5-(6-phenylpyridazin-3-yl)-5-aza-2-azoniabicyclo[2.2.1]heptane (A-585539), K(i) = 0.2-0.6 nM or [(3)H]methyllycaconitine (MLA), 7 nM] that was at least 100-fold selective versus non-alpha7 nAChRs and other receptors. Functionally, ABT-107 did not evoke detectible currents in Xenopus oocytes expressing human or nonhuman alpha3beta4, chimeric (alpha6/alpha3)beta4, or 5-HT(3A) receptors, and weak or negligible Ca(2+) responses in human neuroblastoma IMR-32 cells (alpha3* function) and human alpha4beta2 and alpha4beta4 nAChRs expressed in human embryonic kidney 293 cells. ABT-107 potently evoked human and rat alpha7 nAChR current responses in oocytes (EC(50), 50-90 nM total charge, approximately 80% normalized to acetylcholine) that were enhanced by the positive allosteric modulator (PAM) 4-[5-(4-chloro-phenyl)-2-methyl-3-propionyl-pyrrol-1-yl]-benzenesulfonamide (A-867744). In rat hippocampus, ABT-107 alone evoked alpha7-like currents, which were inhibited by the alpha7 antagonist MLA. In dentate gyrus granule cells, ABT-107 enhanced spontaneous inhibitory postsynaptic current activity when coapplied with A-867744. In the presence of an alpha7 PAM [A-867744 or N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-4-chlorobenzamide hydrochloride (PNU-120596)], the addition of ABT-107 elicited MLA-sensitive alpha7 nAChR-mediated Ca(2+) signals in IMR-32 cells and rat cortical cultures and enhanced extracellular signal-regulated kinase phosphorylation in differentiated PC-12 cells. ABT-107 was also effective in protecting rat cortical cultures against glutamate-induced toxicity. In summary, ABT-107 is a selective high affinity alpha7 nAChR agonist suitable for characterizing the roles of this subtype in pharmacological studies.
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Affiliation(s)
- John Malysz
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott, Abbott Park, Illinois 60064-6125, USA.
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Wood AG, Saling MM, Fedi M, Berkovic SF, Scheffer IE, Benjamin C, Reutens DC. Neuropsychological function in patients with a single gene mutation associated with autosomal dominant nocturnal frontal lobe epilepsy. Epilepsy Behav 2010; 17:531-5. [PMID: 20189461 DOI: 10.1016/j.yebeh.2010.01.168] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 01/29/2010] [Accepted: 01/29/2010] [Indexed: 10/19/2022]
Abstract
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is a nonlesional condition associated with mutation of the gene coding for the alpha4 nicotinic acetylcholine receptor (nAChR). The nAChR modulates aspects of memory and attention. We examined the neuropsychological phenotype of ADNFLE, with a particular emphasis on understanding the impact on frontal lobe functions. We used standard clinical tests as well as focused measures of frontal lobe function in a well-defined group of patients with ADNFLE. Their performance was compared with that of a group of age-, sex-, and education-matched control participants. Patients with ADNFLE showed impairments on tasks requiring cognitive flexibility against a background of well-preserved intellectual abilities. In accord with existing research, verbal memory impairments were identified in the patient group; the level of impairment on these tasks correlated with disease-related factors. In our study of ADNFLE associated with one mutation, cognitive flexibility appears to be the core cognitive deficit.
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Affiliation(s)
- Amanda G Wood
- Department of Medicine, Southern Clinical School, Monash University, Melbourne, Australia.
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Araud T, Wonnacott S, Bertrand D. Associated proteins: The universal toolbox controlling ligand gated ion channel function. Biochem Pharmacol 2010; 80:160-9. [PMID: 20346921 DOI: 10.1016/j.bcp.2010.03.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 03/02/2010] [Accepted: 03/15/2010] [Indexed: 02/06/2023]
Abstract
Ligand gated ion channels are integral multimeric membrane proteins that can detect with high sensitivity the presence of a specific transmitter in the extracellular space and transduce this signal into an ion flux. While these receptors are widely expressed in the nervous system, their expression is not limited to neurons or their postsynaptic targets but extends to non-neuronal cells where they participate in many physiological responses. Cells have developed complex regulatory mechanisms allowing for the precise control and modulation of ligand gated ion channels. In this overview the roles of accessory subunits and associated proteins in these regulatory mechanisms are reviewed and their relevance illustrated by examples at different ligand gated ion channel types, with emphasis on nicotinic acetylcholine receptors. Dysfunction of ligand gated ion channels can result in neuromuscular, neurological or psychiatric disorders. A better understanding of the precise function of associated proteins and how they impact on ligand gated ion channels will provide new therapeutic opportunities for clinical intervention.
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Steinlein OK, Bertrand D. Nicotinic receptor channelopathies and epilepsy. Pflugers Arch 2009; 460:495-503. [DOI: 10.1007/s00424-009-0766-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 11/23/2009] [Accepted: 11/24/2009] [Indexed: 02/05/2023]
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Pearson-Fuhrhop KM, Kleim JA, Cramer SC. Brain plasticity and genetic factors. Top Stroke Rehabil 2009; 16:282-99. [PMID: 19740733 DOI: 10.1310/tsr1604-282] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Brain plasticity refers to changes in brain function and structure that arise in a number of contexts. One area in which brain plasticity is of considerable interest is recovery from stroke, both spontaneous and treatment-induced. A number of factors influence these poststroke brain events. The current review considers the impact of genetic factors. Polymorphisms in the human genes coding for brain-derived neurotrophic factor (BDNF) and apolipoprotein E (ApoE) have been studied in the context of plasticity and/or stroke recovery and are discussed here in detail. Several other genetic polymorphisms are indirectly involved in stroke recovery through their modulating influences on processes such as depression and pharmacotherapy effects. Finally, new genetic polymorphisms that have not been studied in the context of stroke are proposed as new directions for study. A better understanding of genetic influences on recovery and response to therapy might allow improved treatment after stroke.
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Landgren S, Engel JA, Andersson ME, Gonzalez-Quintela A, Campos J, Nilsson S, Zetterberg H, Blennow K, Jerlhag E. Association of nAChR gene haplotypes with heavy alcohol use and body mass. Brain Res 2009; 1305 Suppl:S72-9. [DOI: 10.1016/j.brainres.2009.08.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 07/01/2009] [Accepted: 08/06/2009] [Indexed: 10/20/2022]
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Hu ZJ, Bai L, Tizabi Y, Southerland W. Computational modeling study of human nicotinic acetylcholine receptor for developing new drugs in the treatment of alcoholism. Interdiscip Sci 2009; 1:254-62. [PMID: 20640803 DOI: 10.1007/s12539-009-0052-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Revised: 06/10/2009] [Accepted: 07/08/2009] [Indexed: 11/26/2022]
Abstract
Alcohol abuse and alcoholism are serious and costly problem in USA. Thus, the development of anti-alcoholism agents could be very significant. The understanding of the neurochemical basis underlying the addictive properties of drugs of abuse is imperative for the development of new pharmacological means to reverse the addictive state, prevent relapse or to reduce the intake of addictive compounds. The nicotinic acetylcholine receptors (nAChRs) are important therapeutic targets for various diseases. Recent studies have revealed that the alpha3beta2, alpha3beta3, and alpha6 subunits of nAChR protein family might be pharmacological targets for developing new drugs in the treatment of alcoholism. We have performed computational homology modeling of the alpha3beta2, alpha3beta3, and alpha6 subunits of human nACHRs based upon the recently determined crystal structure of the extracellular domain (ECD) of the mouse nAChR alpha1 subunit complexed with alpha-bungarotoxin at 1.94 A resolution. For comparison, we also built the ECD models of alpha4beta2, and alpha7 subunits of human nACHRs which are neurochemical targets for cessation of smoking. The three-dimensional (3D) models of the ECD of the monomer, and pentamer of these human nAChR were constructed. The docking of the agonist in the ligand-binding pocket of the human nAChR dimers was also performed. Since the nAChR ligand-binding site is a useful target for mutagenesis studies and the rational design of drugs against various diseases, these models provide useful information for future investigation.
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Affiliation(s)
- Zeng-Jian Hu
- Department of Biochemistry and Molecular Biology, Howard University College of Medicine, Washington, DC 20059, USA.
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Alexander JK, Govind AP, Drisdel RC, Blanton MP, Vallejo Y, Lam TT, Green WN. Palmitoylation of nicotinic acetylcholine receptors. J Mol Neurosci 2009; 40:12-20. [PMID: 19693711 DOI: 10.1007/s12031-009-9246-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 07/20/2009] [Indexed: 12/22/2022]
Abstract
It is well established that nicotinic acetylcholine receptors (nAChRs) undergo a number of different posttranslational modifications, such as disulfide bond formation, glycosylation, and phosphorylation. Recently, our laboratory has developed more sensitive assays of protein palmitoylation that have allowed us and others to detect the palmitoylation of relatively low abundant proteins such as ligand-gated ion channels. Here, we present evidence that palmitoylation is prevalent on many subunits of different nAChR subtypes, both muscle-type nAChRs and the neuronal "alpha(4)beta(2)" and "alpha(7)" subtypes most abundant in brain. The loss of ligand binding sites that occurs when palmitoylation is blocked with the inhibitor bromopalmitate suggests that palmitoylation of alpha(4)beta(2) and alpha(7) subtypes occurs during subunit assembly and regulates the formation of ligand binding sites. However, additional experiments are needed to test whether nAChR subunit palmitoylation is involved in other aspects of nAChR trafficking or whether palmitoylation regulates nAChR function. Further investigation would be aided by identifying the sites of palmitoylation on the subunits, and here we propose a mass spectrometry strategy for identification of these sites.
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Affiliation(s)
- J K Alexander
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA
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Millar NS. A review of experimental techniques used for the heterologous expression of nicotinic acetylcholine receptors. Biochem Pharmacol 2009; 78:766-76. [PMID: 19540210 DOI: 10.1016/j.bcp.2009.06.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 06/08/2009] [Accepted: 06/10/2009] [Indexed: 11/18/2022]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are members of the Cys-loop family of neurotransmitter-gated ion channels, a family that also includes receptors for gamma-aminobutyric acid, glycine and 5-hydroxytryptamine. In humans, nAChRs have been implicated in several neurological and psychiatric disorders and are major targets for pharmaceutical drug discovery. In addition, nAChRs are important targets for neuroactive pesticides in insects and in other invertebrates. Historically, nAChRs have been one of the most intensively studied families of neurotransmitter receptors. They were the first neurotransmitter receptors to be biochemically purified and the first to be characterized by molecular cloning and heterologous expression. Although much has been learnt from studies of native nAChRs, the expression of recombinant nAChRs has provided dramatic advances in the characterization of these important receptors. This review will provide a brief history of the characterization of nAChRs by heterologous expression. It will focus, in particular, upon studies of recombinant nAChRs, work that has been conducted by many hundreds of scientists during a period of almost 30 years since the molecular cloning of nAChR subunits in the early 1980s.
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Affiliation(s)
- Neil S Millar
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
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D'hoedt D, Bertrand D. Nicotinic acetylcholine receptors: an overview on drug discovery. Expert Opin Ther Targets 2009; 13:395-411. [DOI: 10.1517/14728220902841045] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Gu W, Lupski JR. CNV and nervous system diseases--what's new? Cytogenet Genome Res 2009; 123:54-64. [PMID: 19287139 DOI: 10.1159/000184692] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2008] [Indexed: 11/19/2022] Open
Abstract
Several new genomic disorders caused by copy number variation (CNV) of genes whose dosage is critical for the physiological function of the nervous system have been recently identified. Dup(7)(q11.23) patients carry duplications of the genomic region deleted in Williams-Beuren syndrome, they are characterized by prominent speech delay. The phenotypes of Potocki-Lupski syndrome and MECP2 duplication syndrome were neuropsychologically examined in detail, which revealed autism as an endophenotype and a prominent behavioral feature of these disorders. Tandem duplication of LMNB1 was reported to cause adult-onset autosomal dominant leukodystrophy. PAFAH1B1/LIS1 and YWHAE, which were deleted in isolated lissencephaly (PAFAH1B1/LIS1 alone) and Miller-Dieker syndrome (both genes), were found to be duplicated in patients with developmental delay. Finally, two novel microdeletion syndromes affecting 17q21.31 and 15q13.3, as well as their reciprocal duplications, were also identified. In this review, we provide an overview of the phenotypic manifestation of these syndromes and the rearrangements causing them.
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Affiliation(s)
- W Gu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
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Helbig I, Mefford HC, Sharp AJ, Guipponi M, Fichera M, Franke A, Muhle H, de Kovel C, Baker C, von Spiczak S, Kron KL, Steinich I, Kleefuss-Lie AA, Leu C, Gaus V, Schmitz B, Klein KM, Reif PS, Rosenow F, Weber Y, Lerche H, Zimprich F, Urak L, Fuchs K, Feucht M, Genton P, Thomas P, Visscher F, de Haan GJ, Møller RS, Hjalgrim H, Luciano D, Wittig M, Nothnagel M, Elger CE, Nürnberg P, Romano C, Malafosse A, Koeleman BPC, Lindhout D, Stephani U, Schreiber S, Eichler EE, Sander T. 15q13.3 microdeletions increase risk of idiopathic generalized epilepsy. Nat Genet 2009; 41:160-2. [PMID: 19136953 DOI: 10.1038/ng.292] [Citation(s) in RCA: 408] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Accepted: 10/27/2008] [Indexed: 11/09/2022]
Abstract
We identified 15q13.3 microdeletions encompassing the CHRNA7 gene in 12 of 1,223 individuals with idiopathic generalized epilepsy (IGE), which were not detected in 3,699 controls (joint P = 5.32 x 10(-8)). Most deletion carriers showed common IGE syndromes without other features previously associated with 15q13.3 microdeletions, such as intellectual disability, autism or schizophrenia. Our results indicate that 15q13.3 microdeletions constitute the most prevalent risk factor for common epilepsies identified to date.
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Affiliation(s)
- Ingo Helbig
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein (Kiel Campus), Schwanenweg 20, 24105 Kiel, Germany
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