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Speculation on How RIC-3 and Other Chaperones Facilitate α7 Nicotinic Receptor Folding and Assembly. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27144527. [PMID: 35889400 PMCID: PMC9318448 DOI: 10.3390/molecules27144527] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/07/2022] [Accepted: 07/09/2022] [Indexed: 11/17/2022]
Abstract
The process of how multimeric transmembrane proteins fold and assemble in the endoplasmic reticulum is not well understood. The alpha7 nicotinic receptor (α7 nAChR) is a good model for multimeric protein assembly since it has at least two independent and specialized chaperones: Resistance to Inhibitors of Cholinesterase 3 (RIC-3) and Nicotinic Acetylcholine Receptor Regulator (NACHO). Recent cryo-EM and NMR data revealed structural features of α7 nAChRs. A ser-ala-pro (SAP) motif precedes a structurally important but unique "latch" helix in α7 nAChRs. A sampling of α7 sequences suggests the SAP motif is conserved from C. elegans to humans, but the latch sequence is only conserved in vertebrates. How RIC-3 and NACHO facilitate receptor subunits folding into their final pentameric configuration is not known. The artificial intelligence program AlphaFold2 recently predicted structures for NACHO and RIC-3. NACHO is highly conserved in sequence and structure across species, but RIC-3 is not. This review ponders how different intrinsically disordered RIC-3 isoforms from C. elegans to humans interact with α7 nAChR subunits despite having little sequence homology across RIC-3 species. Two models from the literature about how RIC-3 assists α7 nAChR assembly are evaluated considering recent structural information about the receptor and its chaperones.
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Suchanecka A, Chmielowiec J, Chmielowiec K, Trybek G, Jaroń A, Czarny W, Król P, Masiak J, Grzywacz A. Serotonin Receptor HTR3A Gene Polymorphisms rs1985242 and rs1062613, E-Cigarette Use and Personality. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19084746. [PMID: 35457612 PMCID: PMC9029000 DOI: 10.3390/ijerph19084746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/09/2022] [Accepted: 04/11/2022] [Indexed: 02/01/2023]
Abstract
We nowadays record growing numbers of e-cigarette users. The development of nicotine dependence is a result of many factors, including genetics and personality. In this study we analyzed two polymorphisms—rs1985242 and rs1062613—in the serotonin receptor HTR3A gene in a group of e-cigarette users (n = 135) and controls (n = 106). Personality traits were measured using the NEO Five-Factor Inventory. The comparison of e-cigarette users with the control group indicates that the former showed significantly higher scores on the neuroticism scale and lower scores on the scales of extraversion and conscientiousness of the NEO-FFI. Homozygote variants of rs1985242 were more frequent in the study group. The results of the 2 × 3 factorial ANOVA for e-cigarette users and the control group as well as interaction between the HTR3A rs1985242 variants were found for the NEO-FFI conscientiousness scale. These results allow us to conclude that the combination of psychological factors and genetic data creates a possibility for making more complete models of substance use disorders.
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Affiliation(s)
- Aleksandra Suchanecka
- Independent Laboratory of Health Promotion, Pomeranian Medical University in Szczecin, 11 Chlapowskiego St., 70-204 Szczecin, Poland;
| | - Jolanta Chmielowiec
- Department of Hygiene and Epidemiology, Collegium Medicum, University of Zielona Góra, Zyty 28 St., 65-046 Zielona Gora, Poland; (J.C.); (K.C.)
| | - Krzysztof Chmielowiec
- Department of Hygiene and Epidemiology, Collegium Medicum, University of Zielona Góra, Zyty 28 St., 65-046 Zielona Gora, Poland; (J.C.); (K.C.)
| | - Grzegorz Trybek
- Department of Oral Surgery, Pomeranian Medical University in Szczecin, 72 Powstanców Wlkp. St., 70-111 Szczecin, Poland; (G.T.); (A.J.)
| | - Aleksandra Jaroń
- Department of Oral Surgery, Pomeranian Medical University in Szczecin, 72 Powstanców Wlkp. St., 70-111 Szczecin, Poland; (G.T.); (A.J.)
| | - Wojciech Czarny
- Faculty of Physical Education, University of Rzeszów, Towarnickiego 3 St., 35-959 Rzeszów, Poland;
| | - Paweł Król
- College of Medical Sciences, Institute of Physical Culture Studies, University of Rzeszow, St. Towarnickiego 3, 35-955 Rzeszów, Poland;
| | - Jolanta Masiak
- Neurophysiological Independent Unit, Department of Psychiatry, Medical University of Lublin, 20-093 Lublin, Poland;
| | - Anna Grzywacz
- Independent Laboratory of Health Promotion, Pomeranian Medical University in Szczecin, 11 Chlapowskiego St., 70-204 Szczecin, Poland;
- Correspondence:
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Li ZL, Gou CY, Wang WH, Li Y, Cui Y, Duan JJ, Chen Y. A novel effect of PDLIM5 in α7 nicotinic acetylcholine receptor upregulation and surface expression. Cell Mol Life Sci 2022; 79:64. [PMID: 35013841 PMCID: PMC11072317 DOI: 10.1007/s00018-021-04115-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 12/17/2021] [Accepted: 12/23/2021] [Indexed: 11/29/2022]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are widespread throughout the central nervous system. Signaling through nAChRs contributes to numerous higher-order functions, including memory and cognition, as well as abnormalities such as nicotine addiction and neurodegenerative disorders. Although recent studies indicate that the PDZ-containing proteins comprising PSD-95 family co-localize with nicotinic acetylcholine receptors and mediate downstream signaling in the neurons, the mechanisms by which α7nAChRs are regulated remain unclear. Here, we show that the PDZ-LIM domain family protein PDLIM5 binds to α7nAChRs and plays a role in nicotine-induced α7nAChRs upregulation and surface expression. We find that chronic exposure to 1 μM nicotine upregulated α7, β2-contained nAChRs and PDLIM5 in cultured hippocampal neurons, and the upregulation of α7nAChRs and PDLIM5 is increased more on the cell membrane than the cytoplasm. Interestingly, in primary hippocampal neurons, α7nAChRs and β2nAChRs display distinct patterns of expression, with α7nAChRs colocalized more with PDLIM5. Furthermore, PDLIM5 interacts with α7nAChRs, but not β2nAChRs in native brain neurons. Knocking down of PDLIM5 in SH-SY5Y abolishes nicotine-induced upregulation of α7nAChRs. In primary hippocampal neurons, using shRNA against PDLIM5 decreased both surface clustering of α7nAChRs and α7nAChRs-mediated currents. Proteomics analysis and isothermal titration calorimetry (ITC) results show that PDLIM5 interacts with α7nAChRs through the PDZ domain, and the interaction between PDLIM5 and α7nAChRs can be promoted by nicotine. Collectively, our data suggest a novel cellular role of PDLIM5 in the regulation of α7nAChRs, which may be relevant to plastic changes in the nervous system.
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Affiliation(s)
- Zi-Lin Li
- Neurobiology Research Center, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, No. 66, Gongchang Road, Guangming District, Shenzhen, 518107, Guangdong, People's Republic of China
| | - Chen-Yu Gou
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzho, 510080, Guangdong, People's Republic of China
| | - Wen-Hui Wang
- Neurobiology Research Center, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, No. 66, Gongchang Road, Guangming District, Shenzhen, 518107, Guangdong, People's Republic of China
| | - Yuan Li
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzho, 510080, Guangdong, People's Republic of China
| | - Yu Cui
- Neurobiology Research Center, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, No. 66, Gongchang Road, Guangming District, Shenzhen, 518107, Guangdong, People's Republic of China
| | - Jing-Jing Duan
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzho, 510080, Guangdong, People's Republic of China.
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, Guangdong, People's Republic of China.
| | - Yuan Chen
- Neurobiology Research Center, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, No. 66, Gongchang Road, Guangming District, Shenzhen, 518107, Guangdong, People's Republic of China.
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Wu M, Liu CZ, Barrall EA, Rissman RA, Joiner WJ. Unbalanced Regulation of α7 nAChRs by Ly6h and NACHO Contributes to Neurotoxicity in Alzheimer's Disease. J Neurosci 2021; 41:8461-8474. [PMID: 34446574 PMCID: PMC8513707 DOI: 10.1523/jneurosci.0494-21.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 08/17/2021] [Accepted: 08/19/2021] [Indexed: 12/24/2022] Open
Abstract
α7 nicotinic acetylcholine receptors (nAChRs) are widely expressed in the brain where they promote fast cholinergic synaptic transmission and serve important neuromodulatory functions. However, their high permeability to Ca2+ also predisposes them to contribute to disease states. Here, using transfected HEK-tsa cells and primary cultured hippocampal neurons from male and female rats, we demonstrate that two proteins called Ly6h and NACHO compete for access to α7 subunits, operating together but in opposition to maintain α7 assembly and activity within a narrow range that is optimal for neuronal function and viability. Using mixed gender human temporal cortex and cultured hippocampal neurons from rats we further show that this balance is perturbed during Alzheimer's disease (AD) because of amyloid β (Aβ)-driven reduction in Ly6h, with severe reduction leading to increased phosphorylated tau and α7-mediated neurotoxicity. Ly6h release into human CSF is also correlated with AD severity. Thus, Ly6h links cholinergic signaling, Aβ and phosphorylated tau and may serve as a novel marker for AD progression.SIGNIFICANCE STATEMENT One of the earliest and most persistent hypotheses regarding Alzheimer's disease (AD) attributes cognitive impairment to loss of cholinergic signaling. More recently, interest has focused on crucial roles for amyloid β (Aβ) and phosphorylated tau in Alzheimer's pathogenesis. Here, we demonstrate that these elements are linked by Ly6h and its counterpart, NACHO, functioning in opposition to maintain assembly of nicotinic acetylcholine receptors (nAChRs) within the physiological range. Our data suggests that Aβ shifts the balance away from Ly6h and toward NACHO, resulting in increased assembly of Ca2+-permeable nAChRs and thus a conversion of basal cholinergic to neurotoxic signaling.
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Affiliation(s)
- Meilin Wu
- Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Clifford Z Liu
- Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Erika A Barrall
- Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Robert A Rissman
- Department of Neurosciences, University of California San Diego, La Jolla, California 92093
- Alzheimer's Disease Research Center, University of California San Diego, La Jolla, California 92093
| | - William J Joiner
- Department of Pharmacology, University of California San Diego, La Jolla, California 92093
- Center for Circadian Biology, University of California San Diego, La Jolla, California 92093
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Camacho-Hernandez GA, Stokes C, Duggan BM, Kaczanowska K, Brandao-Araiza S, Doan L, Papke RL, Taylor P. Synthesis, Pharmacological Characterization, and Structure-Activity Relationships of Noncanonical Selective Agonists for α7 nAChRs. J Med Chem 2019; 62:10376-10390. [PMID: 31675224 DOI: 10.1021/acs.jmedchem.9b01467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A lack of selectivity of classical agonists for the nicotinic acetylcholine receptors (nAChR) has prompted us to identify and develop a distinct scaffold of α7 nAChR-selective ligands. Noncanonical 2,4,6-substituted pyrimidine analogues were framed around compound 40 for a structure-activity relationship study. The new lead compounds activate selectively the α7 nAChRs with EC50's between 30 and 140 nM in a PNU-120596-dependent, cell-based calcium influx assay. After characterizing the expanded lead landscape, we ranked the compounds for rapid activation using Xenopus oocytes expressing human α7 nAChR with a two-electrode voltage clamp. This approach enabled us to define the molecular determinants governing rapid activation, agonist potency, and desensitization of α7 nAChRs after exposure to pyrimidine analogues, thereby distinguishing this subclass of noncanonical agonists from previously defined types of agonists (agonists, partial agonists, silent agonists, and ago-PAMs). By NMR, we analyzed pKa values for ionization of lead candidates, demonstrating distinctive modes of interaction for this landscape of ligands.
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Affiliation(s)
- Gisela Andrea Camacho-Hernandez
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences , University of California-San Diego , La Jolla , California 92093-0751 , United States
| | - Clare Stokes
- Department of Pharmacology & Therapeutics , University of Florida , P.O. Box 100267, Gainesville , Florida 32610-0267 , United States
| | - Brendan M Duggan
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences , University of California-San Diego , La Jolla , California 92093-0751 , United States
| | - Katarzyna Kaczanowska
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences , University of California-San Diego , La Jolla , California 92093-0751 , United States
| | - Stefania Brandao-Araiza
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences , University of California-San Diego , La Jolla , California 92093-0751 , United States
| | - Lisa Doan
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences , University of California-San Diego , La Jolla , California 92093-0751 , United States
| | - Roger L Papke
- Department of Pharmacology & Therapeutics , University of Florida , P.O. Box 100267, Gainesville , Florida 32610-0267 , United States
| | - Palmer Taylor
- Department of Pharmacology & Therapeutics , University of Florida , P.O. Box 100267, Gainesville , Florida 32610-0267 , United States
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7
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Phoolcharoen W, Banyard AC, Prehaud C, Selden D, Wu G, Birch CPD, Szeto TH, Lafon M, Fooks AR, Ma JKC. In vitro and in vivo evaluation of a single chain antibody fragment generated in planta with potent rabies neutralisation activity. Vaccine 2019; 37:4673-4680. [PMID: 29523449 PMCID: PMC6677913 DOI: 10.1016/j.vaccine.2018.02.057] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 01/31/2018] [Accepted: 02/15/2018] [Indexed: 12/13/2022]
Abstract
Rabies causes more than 60,000 human deaths annually in areas where the virus is endemic. Importantly, rabies is one of the few pathogens for which there is no treatment following the onset of clinical disease with the outcome of infection being death in almost 100% of cases. Whilst vaccination, and the combination of vaccine and rabies immunoglobulin treatment for post-exposure administration are available, no tools have been identified that can reduce or prevent rabies virus replication once clinical disease has initiated. The search for effective antiviral molecules to treat those that have already developed clinical disease associated with rabies virus infection is considered one of the most important goals in rabies research. The current study assesses a single chain antibody molecule (ScFv) based on a monoclonal antibody that potently neutralises rabies in vitro as a potential therapeutic candidate. The recombinant ScFv was generated in Nicotiana benthamiana by transient expression, and was chemically conjugated (ScFv/RVG) to a 29 amino acid peptide, specific for nicotinic acetylcholine receptor (nAchR) binding in the CNS. This conjugated molecule was able to bind nAchR in vitro and enter neuronal cells more efficiently than ScFv. The ability of the ScFv/RVG to neutralise virus in vivo was assessed using a staggered administration where the molecule was inoculated either four hours before, two days after or four days after infection. The ScFv/RVG conjugate was evaluated in direct comparison with HRIG and a potential antiviral molecule, Favipiravir (also known as T-705) to indicate whether there was greater bioavailability of the ScFv in the brains of treated mice. The study indicated that the approach taken with the ScFv/RVG conjugate may have utility in the design and implementation of novel tools targetting rabies virus infection in the brain.
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Affiliation(s)
- Waranyoo Phoolcharoen
- Institute for Infection and Immunity, St. George's Hospital Medical School, University of London, London, UK; Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Ashley C Banyard
- Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency (APHA), Addlestone, Surrey KT15 3NB, UK
| | - Christophe Prehaud
- Institut Pasteur, Unité de Neuroimmunologie Virale, Département de Virologie, Paris, France
| | - David Selden
- Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency (APHA), Addlestone, Surrey KT15 3NB, UK
| | - Guanghui Wu
- Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency (APHA), Addlestone, Surrey KT15 3NB, UK
| | - Colin P D Birch
- Biomathematics and Risk Research Group, Animal and Plant Health Agency (APHA), Addlestone, Surrey KT15 3NB, UK
| | - Tim H Szeto
- Institute for Infection and Immunity, St. George's Hospital Medical School, University of London, London, UK
| | - Monique Lafon
- Institut Pasteur, Unité de Neuroimmunologie Virale, Département de Virologie, Paris, France
| | - Anthony R Fooks
- Wildlife Zoonoses and Vector-borne Diseases Research Group, Animal and Plant Health Agency (APHA), Addlestone, Surrey KT15 3NB, UK
| | - Julian K-C Ma
- Institute for Infection and Immunity, St. George's Hospital Medical School, University of London, London, UK.
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Potential roles of 5-HT 3 receptor (5-HT 3R) antagonists in modulating the effects of nicotine. Biomed Pharmacother 2019; 112:108630. [PMID: 30797147 DOI: 10.1016/j.biopha.2019.108630] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 01/17/2019] [Accepted: 01/28/2019] [Indexed: 12/22/2022] Open
Abstract
5-HT3R antagonists such as ondansetron, granisetron and tropisetron have been clinically used to treat nausea and vomiting in chemotherapy patients. However, current study and research revealed novel potentials of these ligands in other diseases like inflammation, Alzheimer's, and drug abuse. Towards utilising these drugs as anti-smoking agents to treat nicotine dependence problem, there are conflicting reports regarding the potential of these ligands in modulating the effects of nicotine in both human and animal behavioural studies. This is complicated by the heterogeneity of 5-HT3R itself, cross regulation between nicotinic acetylcholinergic receptor (nAChR) and distinct pharmacological profiles of 5-HT3R antagonists. This review gathered existing studies conducted investigating the potential of "-setron" class of 5-HT3R antagonists in modulating nicotine effects. We proposed that the mechanism where 5-HT3R antagonists mediate the effects of nicotine could be attributed by both direct at 5-HT3R and indirect mechanism in nicotine addiction downstream regulation. The indirect mechanism mediated by the 5-HT3R antagonist could be through α7 nAChR, 5-HT1B receptor (5-HT1BR), 5-HT1C receptor (5-HT1CR), calcineurin activity, p38 MAPK level, PPAR-γ and NF-κβ. Our review suggested that future studies should focus on newer 5-HT3R antagonist with superior pharmacological profile or the one with multitarget action rather than high selectivity at single receptor.
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Manetti D, Garifulina A, Bartolucci G, Bazzicalupi C, Bellucci C, Chiaramonte N, Dei S, Di Cesare Mannelli L, Ghelardini C, Gratteri P, Spirova E, Shelukhina I, Teodori E, Varani K, Tsetlin V, Romanelli MN. New Rigid Nicotine Analogues, Carrying a Norbornane Moiety, Are Potent Agonists of α7 and α3* Nicotinic Receptors. J Med Chem 2019; 62:1887-1901. [PMID: 30681854 DOI: 10.1021/acs.jmedchem.8b01372] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A three-dimensional database search has been applied to design a series of endo- and exo-3-(pyridin-3-yl)bicyclo[2.2.1]heptan-2-amines as nicotinic receptor ligands. The synthesized compounds were tested in radioligand binding assay on rat cortex against [3H]-cytisine and [3H]-methyllycaconitine to measure their affinity for α4β2* and α7* nicotinic receptors. The new derivatives showed some preference for the α4β2* over the α7* subtype, with their affinity being dependent on the endo/exo isomerism and on the methylation degree of the basic nitrogen. The endo primary amines displayed the lowest Ki values on both receptor subtypes. Selected compounds (1a, 2a, 3a, and 6a) were tested on heterologously expressed α4β2, α7, and α3β2 receptors and on SHSY-5Y cells. Compounds 1a and 2a showed α4β2 antagonistic properties while behaved as full agonists on recombinant α7 and on SHSY5Y cells. On the α3β2 subtype, only the chloro derivative 2a showed full agonist activity and submicromolar potency (EC50 = 0.43 μM). The primary amines described here represent new chemotypes for the α7 and α3* receptor subtypes.
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Affiliation(s)
- Dina Manetti
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences , University of Florence , Via Ugo Schiff 6 , 50019 Sesto Fiorentino , Italy
| | - Alexandra Garifulina
- Department of Molecular Basis of Neurosignaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry , Russian Academy of Sciences , Miklukho-Maklaya Street 16/10 , 117997 Moscow , Russia
| | - Gianluca Bartolucci
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences , University of Florence , Via Ugo Schiff 6 , 50019 Sesto Fiorentino , Italy
| | - Carla Bazzicalupi
- Department of Chemistry "Ugo Schiff" , University of Florence , Via della Lastruccia 3 , 50019 Sesto Fiorentino , Italy
| | - Cristina Bellucci
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences , University of Florence , Via Ugo Schiff 6 , 50019 Sesto Fiorentino , Italy
| | - Niccolò Chiaramonte
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences , University of Florence , Via Ugo Schiff 6 , 50019 Sesto Fiorentino , Italy
| | - Silvia Dei
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences , University of Florence , Via Ugo Schiff 6 , 50019 Sesto Fiorentino , Italy
| | - Lorenzo Di Cesare Mannelli
- Department of NEUROFARBA, Section of Pharmacology and Toxicology , University of Florence , Viale G Pieraccini 6 , 50139 Firenze , Italy
| | - Carla Ghelardini
- Department of NEUROFARBA, Section of Pharmacology and Toxicology , University of Florence , Viale G Pieraccini 6 , 50139 Firenze , Italy
| | - Paola Gratteri
- Department of NEUROFARBA, Laboratory of Molecular Modeling Cheminformatics & QSAR , University of Firenze , Via Ugo Schiff 6 , 50019 Sesto Fiorentino , Italy
| | - Ekaterina Spirova
- Department of Molecular Basis of Neurosignaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry , Russian Academy of Sciences , Miklukho-Maklaya Street 16/10 , 117997 Moscow , Russia
| | - Irina Shelukhina
- Department of Molecular Basis of Neurosignaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry , Russian Academy of Sciences , Miklukho-Maklaya Street 16/10 , 117997 Moscow , Russia
| | - Elisabetta Teodori
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences , University of Florence , Via Ugo Schiff 6 , 50019 Sesto Fiorentino , Italy
| | - Katia Varani
- Institute of Pharmacology , University of Ferrara , Via Fossato di Mortara 17-19 , 44100 Ferrara , Italy
| | - Victor Tsetlin
- Department of Molecular Basis of Neurosignaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry , Russian Academy of Sciences , Miklukho-Maklaya Street 16/10 , 117997 Moscow , Russia
| | - Maria Novella Romanelli
- Department of Neuroscience, Psychology, Drug Research and Child's Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences , University of Florence , Via Ugo Schiff 6 , 50019 Sesto Fiorentino , Italy
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10
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Spirova EN, Ivanov IA, Kasheverov IE, Kudryavtsev DS, Shelukhina IV, Garifulina AI, Son LV, Lummis SCR, Malca-Garcia GR, Bussmann RW, Hennig L, Giannis A, Tsetlin VI. Curare alkaloids from Matis Dart Poison: Comparison with d-tubocurarine in interactions with nicotinic, 5-HT3 serotonin and GABAA receptors. PLoS One 2019; 14:e0210182. [PMID: 30608952 PMCID: PMC6319706 DOI: 10.1371/journal.pone.0210182] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 12/18/2018] [Indexed: 12/16/2022] Open
Abstract
Several novel bisbenzylisoquinoline alkaloids (BBIQAs) have recently been isolated from a Matis tribe arrow poison and shown by two-electrode voltage-clamp to inhibit mouse muscle nicotinic acetylcholine receptors (nAChR). Here, using radioligand assay with Aplysia californica AChBP and radioiodinated α-bungarotoxin ([125I]-αBgt), we show that BBIQA1, BBIQA2, and d-tubocurarine (d-TC) have similar affinities to nAChR orthosteric site. However, a competition with [125I]-αBgt for binding to the Torpedo californica muscle-type nAChR revealed that BBIQAs1, 2, and 3 are less potent (IC50s = 26.3, 8.75, and 17.0 μM) than d-TC (IC50 = 0.39 μM), while with α7 nAChR in GH4C1 cells, BBIQA1 was less potent that d-TC (IC50s = 162 μM and 7.77 μM, respectively), but BBIQA2 was similar (IC50 = 5.52 μM). In inhibiting the Ca2+ responses induced by acetylcholine in Neuro2a cells expressing the mouse adult α1β1εδ nAChR or human α7 nAChR, BBIQAs1 and 2 had similar potencies to d-TC (IC50s in the range 0.75-3.08 μM). Our data suggest that BBIQA1 and BBIQA2 can inhibit adult muscle α1β1εδ nAChR by both competitive and noncompetitive mechanisms. Further experiments on neuronal α3β2, α4β2, and α9α10 nAChRs, expressed in Xenopus laevis oocytes, showed that similar potencies for BBIQAs1, 2, and d-TC. With α3β2γ2 GABAAR currents were almost completely inhibited by d-TC at a high (100 μM) concentration, but BBIQAs1 and 2 were less potent (only 40-50% inhibition), whereas in competition with Alexa Fluor 546-α-cobratoxin for binding to α1β3γ2 GABAAR in Neuro2a cells, d-TC and these analogs had comparable affinities. Especially interesting effects of BBIQAs1 and 2 in comparison with d-TC were observed for 5-HT3AR: BBIQA1 and BBIQA2 were 5- and 87-fold less potent than d-TC (IC50 = 22.63 nM). Thus, our results reveal that these BBIQAs differ from d-TC in their potencies towards certain Cys-loop receptors, and we suggest that understanding the reasons behind this might be useful for future drug design.
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Affiliation(s)
- Ekaterina N. Spirova
- Department of Molecular Neuroimmune signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Igor A. Ivanov
- Department of Molecular Neuroimmune signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Igor E. Kasheverov
- Department of Molecular Neuroimmune signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Moscow, Russia
| | - Denis S. Kudryavtsev
- Department of Molecular Neuroimmune signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Irina V. Shelukhina
- Department of Molecular Neuroimmune signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexandra I. Garifulina
- Department of Molecular Neuroimmune signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Lina V. Son
- Department of Molecular Neuroimmune signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Sarah C. R. Lummis
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Gonzalo R. Malca-Garcia
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, United States of America
| | | | - Lothar Hennig
- Institut für Organische Chemie, Fakultät für Chemie und Mineralogie, Universität Leipzig, Leipzig, Germany
| | - Athanassios Giannis
- Institut für Organische Chemie, Fakultät für Chemie und Mineralogie, Universität Leipzig, Leipzig, Germany
| | - Victor I. Tsetlin
- Department of Molecular Neuroimmune signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- PhysBio of MEPhI, Moscow, Russia
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11
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Greenwald EC, Mehta S, Zhang J. Genetically Encoded Fluorescent Biosensors Illuminate the Spatiotemporal Regulation of Signaling Networks. Chem Rev 2018; 118:11707-11794. [PMID: 30550275 PMCID: PMC7462118 DOI: 10.1021/acs.chemrev.8b00333] [Citation(s) in RCA: 302] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cellular signaling networks are the foundation which determines the fate and function of cells as they respond to various cues and stimuli. The discovery of fluorescent proteins over 25 years ago enabled the development of a diverse array of genetically encodable fluorescent biosensors that are capable of measuring the spatiotemporal dynamics of signal transduction pathways in live cells. In an effort to encapsulate the breadth over which fluorescent biosensors have expanded, we endeavored to assemble a comprehensive list of published engineered biosensors, and we discuss many of the molecular designs utilized in their development. Then, we review how the high temporal and spatial resolution afforded by fluorescent biosensors has aided our understanding of the spatiotemporal regulation of signaling networks at the cellular and subcellular level. Finally, we highlight some emerging areas of research in both biosensor design and applications that are on the forefront of biosensor development.
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Affiliation(s)
- Eric C Greenwald
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Sohum Mehta
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Jin Zhang
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
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12
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Phoolcharoen W, Prehaud C, van Dolleweerd CJ, Both L, da Costa A, Lafon M, Ma JK. Enhanced transport of plant-produced rabies single-chain antibody-RVG peptide fusion protein across an in cellulo blood-brain barrier device. PLANT BIOTECHNOLOGY JOURNAL 2017; 15:1331-1339. [PMID: 28273388 PMCID: PMC5595719 DOI: 10.1111/pbi.12719] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 02/12/2017] [Accepted: 03/01/2017] [Indexed: 05/03/2023]
Abstract
The biomedical applications of antibody engineering are developing rapidly and have been expanded to plant expression platforms. In this study, we have generated a novel antibody molecule in planta for targeted delivery across the blood-brain barrier (BBB). Rabies virus (RABV) is a neurotropic virus for which there is no effective treatment after entry into the central nervous system. This study investigated the use of a RABV glycoprotein peptide sequence to assist delivery of a rabies neutralizing single-chain antibody (ScFv) across an in cellulo model of human BBB. The 29 amino acid rabies virus peptide (RVG) recognizes the nicotinic acetylcholine receptor (nAchR) at neuromuscular junctions and the BBB. ScFv and ScFv-RVG fusion proteins were produced in Nicotiana benthamiana by transient expression. Both molecules were successfully expressed and purified, but the ScFv expression level was significantly higher than that of ScFv-RVG fusion. Both ScFv and ScFv-RVG fusion molecules had potent neutralization activity against RABVin cellulo. The ScFv-RVG fusion demonstrated increased binding to nAchR and entry into neuronal cells, compared to ScFv alone. Additionally, a human brain endothelial cell line BBB model was used to demonstrate that plant-produced ScFv-RVGP fusion could translocate across the cells. This study indicates that the plant-produced ScFv-RVGP fusion protein was able to cross the in celluloBBB and neutralize RABV.
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Affiliation(s)
- Waranyoo Phoolcharoen
- Institute for Infection and ImmunitySt. George's Hospital Medical SchoolUniversity of LondonLondonUK
- Pharmacognosy and Pharmaceutical BotanyFaculty of Pharmaceutical SciencesChulalongkorn UniversityBangkokThailand
| | - Christophe Prehaud
- Unité de Neuroimmunologie ViraleDépartement de VirologieInstitut PasteurParisFrance
| | - Craig J. van Dolleweerd
- Institute for Infection and ImmunitySt. George's Hospital Medical SchoolUniversity of LondonLondonUK
| | - Leonard Both
- Institute for Infection and ImmunitySt. George's Hospital Medical SchoolUniversity of LondonLondonUK
| | - Anaelle da Costa
- Unité de Neuroimmunologie ViraleDépartement de VirologieInstitut PasteurParisFrance
| | - Monique Lafon
- Unité de Neuroimmunologie ViraleDépartement de VirologieInstitut PasteurParisFrance
| | - Julian K‐C. Ma
- Institute for Infection and ImmunitySt. George's Hospital Medical SchoolUniversity of LondonLondonUK
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13
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Shelukhina I, Spirova E, Kudryavtsev D, Ojomoko L, Werner M, Methfessel C, Hollmann M, Tsetlin V. Calcium imaging with genetically encoded sensor Case12: Facile analysis of α7/α9 nAChR mutants. PLoS One 2017; 12:e0181936. [PMID: 28797116 PMCID: PMC5552293 DOI: 10.1371/journal.pone.0181936] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 07/10/2017] [Indexed: 11/17/2022] Open
Abstract
Elucidation of the structural basis of pharmacological differences for highly homologous α7 and α9 nicotinic acetylcholine receptors (nAChRs) may shed light on their involvement in different physiological functions and diseases. Combination of site-directed mutagenesis and electrophysiology is a powerful tool to pinpoint the key amino-acid residues in the receptor ligand-binding site, but for α7 and α9 nAChRs it is complicated by their poor expression and fast desensitization. Here, we probed the ligand-binding properties of α7/α9 nAChR mutants by a proposed simple and fast calcium imaging method. The method is based on transient co-expression of α7/α9 nAChR mutants in neuroblastoma cells together with Ric-3 or NACHO chaperones and Case12 fluorescent calcium ion sensor followed by analysis of their pharmacology using a fluorescence microscope or a fluorometric imaging plate reader (FLIPR) with a GFP filter set. The results obtained were confirmed by electrophysiology and by calcium imaging with the conventional calcium indicator Fluo-4. The affinities for acetylcholine and epibatidine were determined for human and rat α7 nAChRs, and for their mutants with homologous residues of α9 nAChR incorporated at positions 117-119, 184, 185, 187, and 189, which are anticipated to be involved in ligand binding. The strongest decrease in the affinity was observed for mutations at positions 187 and 119. The L119D mutation of α7 nAChR, showing a larger effect for epibatidine than for acetylcholine, may implicate this position in pharmacological differences between α7 and α9 nAChRs.
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Affiliation(s)
- Irina Shelukhina
- Department of Molecular Basis of Neurosignalling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Ekaterina Spirova
- Department of Molecular Basis of Neurosignalling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Denis Kudryavtsev
- Department of Molecular Basis of Neurosignalling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Lucy Ojomoko
- Department of Molecular Basis of Neurosignalling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Markus Werner
- Department of Biochemistry I, Ruhr University Bochum, Bochum, Germany
| | | | - Michael Hollmann
- Department of Biochemistry I, Ruhr University Bochum, Bochum, Germany
| | - Victor Tsetlin
- Department of Molecular Basis of Neurosignalling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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14
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Kaczanowska K, Camacho Hernandez GA, Bendiks L, Kohs L, Cornejo-Bravo JM, Harel M, Finn MG, Taylor P. Substituted 2-Aminopyrimidines Selective for α7-Nicotinic Acetylcholine Receptor Activation and Association with Acetylcholine Binding Proteins. J Am Chem Soc 2017; 139:3676-3684. [DOI: 10.1021/jacs.6b10746] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Katarzyna Kaczanowska
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0650, United States,
| | - Gisela Andrea Camacho Hernandez
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0650, United States,
- Facultad
de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad 14418, Tijuana, Baja California 22390, Mexico
| | - Larissa Bendiks
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0650, United States,
| | - Larissa Kohs
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0650, United States,
| | - Jose Manuel Cornejo-Bravo
- Facultad
de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Calzada Universidad 14418, Tijuana, Baja California 22390, Mexico
| | - Michal Harel
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0650, United States,
| | - M. G. Finn
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0650, United States,
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15
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Lacin E, Muller A, Fernando M, Kleinfeld D, Slesinger PA. Construction of Cell-based Neurotransmitter Fluorescent Engineered Reporters (CNiFERs) for Optical Detection of Neurotransmitters In Vivo. J Vis Exp 2016:53290. [PMID: 27214050 PMCID: PMC4939270 DOI: 10.3791/53290] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Cell-based neurotransmitter fluorescent engineered reporters (CNiFERs) provide a new tool for neuroscientists to optically detect the release of neurotransmitters in the brain in vivo. A specific CNiFER is created from a human embryonic kidney cell that stably expresses a specific G protein-coupled receptor, which couples to Gq/11 G proteins, and a FRET-based Ca(2+)-detector, TN-XXL. Activation of the receptor leads to an increase in the FRET signal. CNiFERs have nM sensitivity and a temporal response of seconds because a CNiFER clone utilizes the native receptor for a particular neurotransmitter, e.g., D2R for dopamine. CNiFERs are directly implanted into the brain, enabling them to sense neurotransmitter release with a spatial resolution of less than one hundred µm, making them ideal to measure volume transmission in vivo. CNiFERs can also be used to screen other drugs for potential cross-reactivity in vivo. We recently expanded the family of CNiFERs to include GPCRs that couple to Gi/o G proteins. CNiFERs are available for detecting acetylcholine (ACh), dopamine (DA) and norepinephrine (NE). Given that any GPCR can be used to create a novel CNiFER and that there are approximately 800 GPCRs in the human genome, we describe here the general procedure to design, realize, and test any type of CNiFER.
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Affiliation(s)
- Emre Lacin
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai
| | - Arnaud Muller
- Department of Physics, University of California, San Diego
| | - Marian Fernando
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai
| | - David Kleinfeld
- Department of Physics, University of California, San Diego; Section of Neurobiology, University of California, San Diego;
| | - Paul A Slesinger
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai;
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16
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Wu M, Puddifoot CA, Taylor P, Joiner WJ. Mechanisms of inhibition and potentiation of α4β2 nicotinic acetylcholine receptors by members of the Ly6 protein family. J Biol Chem 2015; 290:24509-18. [PMID: 26276394 DOI: 10.1074/jbc.m115.647248] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Indexed: 11/06/2022] Open
Abstract
α4β2 nicotinic acetylcholine receptors (nAChRs) are abundantly expressed throughout the central nervous system and are thought to be the primary target of nicotine, the main addictive substance in cigarette smoking. Understanding the mechanisms by which these receptors are regulated may assist in developing compounds to selectively interfere with nicotine addiction. Here we report previously unrecognized modulatory properties of members of the Ly6 protein family on α4β2 nAChRs. Using a FRET-based Ca(2+) flux assay, we found that the maximum response of α4β2 receptors to agonist was strongly inhibited by Ly6h and Lynx2 but potentiated by Ly6g6e. The mechanisms underlying these opposing effects appear to be fundamentally distinct. Receptor inhibition by Lynx2 was accompanied by suppression of α4β2 expression at the cell surface, even when assays were preceded by chronic exposure of cells to an established chaperone, nicotine. Receptor inhibition by Lynx2 also was resistant to pretreatment with extracellular phospholipase C, which cleaves lipid moieties like those that attach Ly6 proteins to the plasma membrane. In contrast, potentiation of α4β2 activity by Ly6g6e was readily reversible by pretreatment with phospholipase C. Potentiation was also accompanied by slowing of receptor desensitization and an increase in peak currents. Collectively our data support roles for Lynx2 and Ly6g6e in intracellular trafficking and allosteric potentiation of α4β2 nAChRs, respectively.
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Affiliation(s)
| | | | - Palmer Taylor
- From the Department of Pharmacology, Biomedical Sciences Graduate Program, Neuroscience Graduate Program, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California 92093-0636
| | - William J Joiner
- From the Department of Pharmacology, Biomedical Sciences Graduate Program, Neuroscience Graduate Program, Center for Circadian Biology, and
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17
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Ly6h regulates trafficking of alpha7 nicotinic acetylcholine receptors and nicotine-induced potentiation of glutamatergic signaling. J Neurosci 2015; 35:3420-30. [PMID: 25716842 DOI: 10.1523/jneurosci.3630-14.2015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
α7 nAChRs are expressed widely throughout the brain, where they are important for synaptic signaling, gene transcription, and plastic changes that regulate sensory processing, cognition, and neural responses to chronic nicotine exposure. However, the mechanisms by which α7 nAChRs are regulated are poorly understood. Here we show that trafficking of α7-subunits is controlled by endogenous membrane-associated prototoxins in the Ly6 family. In particular, we find that Ly6h reduces cell-surface expression and calcium signaling by α7 nAChRs. We detect Ly6h in several rat brain regions, including the hippocampus, where we find it is both necessary and sufficient to limit the magnitude of α7-mediated currents. Consistent with such a regulatory function, knockdown of Ly6h in rat hippocampal pyramidal neurons enhances nicotine-induced potentiation of glutamatergic mEPSC amplitude, which is known to be mediated by α7 signaling. Collectively our data suggest a novel cellular role for Ly6 proteins in regulating nAChRs, which may be relevant to plastic changes in the nervous system including rewiring of glutamatergic circuitry during nicotine addiction.
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18
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Bourne Y, Sulzenbacher G, Radić Z, Aráoz R, Reynaud M, Benoit E, Zakarian A, Servent D, Molgó J, Taylor P, Marchot P. Marine Macrocyclic Imines, Pinnatoxins A and G: Structural Determinants and Functional Properties to Distinguish Neuronal α7 from Muscle α1(2)βγδ nAChRs. Structure 2015; 23:1106-15. [PMID: 26004441 DOI: 10.1016/j.str.2015.04.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 04/03/2015] [Accepted: 04/04/2015] [Indexed: 10/23/2022]
Abstract
Pinnatoxins are macrocyclic imine phycotoxins associated with algal blooms and shellfish toxicity. Functional analysis of pinnatoxin A and pinnatoxin G by binding and voltage-clamp electrophysiology on membrane-embedded neuronal α7, α4β2, α3β2, and muscle-type α12βγδ nicotinic acetylcholine receptors (nAChRs) reveals high-affinity binding and potent antagonism for the α7 and α12βγδ subtypes. The toxins also bind to the nAChR surrogate, acetylcholine-binding protein (AChBP), with low Kd values reflecting slow dissociation. Crystal structures of pinnatoxin-AChBP complexes (1.9-2.2 Å resolution) show the multiple anchoring points of the hydrophobic portion, the cyclic imine, and the substituted bis-spiroketal and cyclohexene ring systems of the pinnatoxins that dictate tight binding between the opposing loops C and F at the receptor subunit interface, as observed for the 13-desmethyl-spirolide C and gymnodimine A congeners. Uniquely, however, the bulky bridged EF-ketal ring specific to the pinnatoxins extends radially from the interfacial-binding pocket to interact with the sequence-variable loop F and govern nAChR subtype selectivity and central neurotoxicity.
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Affiliation(s)
- Yves Bourne
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France; Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France.
| | - Gerlind Sulzenbacher
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France; Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France
| | - Zoran Radić
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093-0650, USA
| | - Rómulo Aráoz
- Institut des Neurosciences Paris-Saclay, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Morgane Reynaud
- Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Evelyne Benoit
- Institut des Neurosciences Paris-Saclay, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Armen Zakarian
- Department of Chemistry and Biochemistry, University of California Santa Barbara, CA 93106-9510, USA
| | - Denis Servent
- Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Jordi Molgó
- Institut des Neurosciences Paris-Saclay, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093-0650, USA
| | - Pascale Marchot
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France; Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France.
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19
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Arunrungvichian K, Fokin VV, Vajragupta O, Taylor P. Selectivity Optimization of Substituted 1,2,3-Triazoles as α7 Nicotinic Acetylcholine Receptor Agonists. ACS Chem Neurosci 2015; 6:1317-30. [DOI: 10.1021/acschemneuro.5b00058] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Kuntarat Arunrungvichian
- Center
of Excellence for Innovation in Drug Design and Discovery, Faculty
of Pharmacy, Mahidol University, 447 Sri-Ayudhya Road, Bangkok 10400, Thailand
- Department
of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0650, United States
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Valery V. Fokin
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Opa Vajragupta
- Center
of Excellence for Innovation in Drug Design and Discovery, Faculty
of Pharmacy, Mahidol University, 447 Sri-Ayudhya Road, Bangkok 10400, Thailand
| | - Palmer Taylor
- Department
of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0650, United States
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20
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Cell-based reporters reveal in vivo dynamics of dopamine and norepinephrine release in murine cortex. Nat Methods 2014; 11:1245-52. [PMID: 25344639 PMCID: PMC4245316 DOI: 10.1038/nmeth.3151] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 09/14/2014] [Indexed: 11/11/2022]
Abstract
Neuronal coding of stimulus-to-action sequences are believed to involve the release of dopamine (DA) and norepinephrine (NE). The electrochemical similarity of these monoamines, however, confounds real-time measurements of their release. Here we report the creation of cell-based neurotransmitter fluorescent-engineered reporters (CNiFERs) that utilize the specificity of G-protein coupled receptors (GPCRs) to discriminate nanomolar concentrations of DA and NE. CNiFERs were implanted into frontal cortex of mice to measure the timing of neurotransmitter release during classical conditioning using two-photon microscopy. The onset of DA release correlated with that of licking and monotonically shifted from the time of the reward toward that of the cue. In contrast, concurrent release of NE did not correlate with licking or the cue. This new generation of CNiFERs provides unique tools to assess the release of monoamines. The molecular design of these CNiFERs may be generalized to realize CNiFERs for any molecule that activates a GPCR.
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21
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Kobayashi A, Parker RL, Wright AP, Brahem H, Ku P, Oliver KM, Walz A, Lester HA, Miwa JM. Lynx1 supports neuronal health in the mouse dorsal striatum during aging: an ultrastructural investigation. J Mol Neurosci 2014; 53:525-36. [PMID: 25027556 DOI: 10.1007/s12031-014-0352-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 06/09/2014] [Indexed: 10/25/2022]
Abstract
Nicotinic acetylcholine receptors have been shown to participate in neuroprotection in the aging brain. Lynx protein modulators dampen the activity of the cholinergic system through direct interaction with nicotinic receptors. Although lynx1 null mutant mice exhibit augmented learning and plasticity, they also exhibit macroscopic vacuolation in the dorsal striatum as they age, detectable at the optical microscope level. Despite the relevance of the lynx1 gene to brain function, little is known about the cellular ultrastructure of these age-related changes. In this study, we assessed degeneration in the dorsal striatum in 1-, 3-, 7-, and 13-month-old mice, using optical and transmission electron microscopy. We observed a loss of nerve fibers, a breakdown in nerve fiber bundles, and a loss of neuronal nuclei in the 13-month-old lynx1 null striatum. At higher magnification, these nerve fibers displayed intracellular vacuoles and disordered myelin sheaths. Few or none of these morphological alterations were present in younger lynx1 null mutant mice or in heterozygous lynx1 null mutant mice at any age. These data indicate that neuronal health can be maintained by titrating lynx1 dosage and that the lynx1 gene may participate in a trade-off between neuroprotection and augmented learning.
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Affiliation(s)
- Atsuko Kobayashi
- Biology Division, California Institute of Technology, MC156-29, 1200 E. California Blvd., Pasadena, CA, 91125, USA
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Yang J, Li MD. Association and interaction analyses of 5-HT3 receptor and serotonin transporter genes with alcohol, cocaine, and nicotine dependence using the SAGE data. Hum Genet 2014; 133:905-18. [PMID: 24590108 PMCID: PMC4055533 DOI: 10.1007/s00439-014-1431-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 02/16/2014] [Indexed: 12/29/2022]
Abstract
Previous studies have implicated genes encoding the 5-HT3AB receptors (HTR3A and HTR3B) and the serotonin transporter (SLC6A4), both independently and interactively, in alcohol (AD), cocaine (CD), and nicotine dependence (ND). However, whether these genetic effects also exist in subjects with comorbidities remains largely unknown. We used 1,136 African-American (AA) and 2,428 European-American (EA) subjects from the Study of Addiction: Genetics and Environment (SAGE) to determine associations between 88 genotyped or imputed variants within HTR3A, HTR3B, and SLC6A4 and three types of addictions, which were measured by DSM-IV diagnoses of AD, CD, and ND and the Fagerström Test for Nicotine Dependence (FTND), an independent measure of ND commonly used in tobacco research. Individual SNP-based association analysis revealed a significant association of rs2066713 in SLC6A4 with FTND in AA (β = -1.39; P = 1.6E - 04). Haplotype-based association analysis found one major haplotype formed by SNPs rs3891484 and rs3758987 in HTR3B that was significantly associated with AD in the AA sample, and another major haplotype T-T-G, formed by SNPs rs7118530, rs12221649, and rs2085421 in HTR3A, which showed significant association with FTND in the EA sample. Considering the biologic roles of the three genes and their functional relations, we used the GPU-based Generalized Multifactor Dimensionality Reduction (GMDR-GPU) program to test SNP-by-SNP interactions within the three genes and discovered two- to five-variant models that have significant impacts on AD, CD, ND, or FTND. Interestingly, most of the SNPs included in the genetic interaction model(s) for each addictive phenotype are either overlapped or in high linkage disequilibrium for both AA and EA samples, suggesting these detected variants in HTR3A, HTR3B, and SLC6A4 are interactively contributing to etiology of the three addictive phenotypes examined in this study.
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Affiliation(s)
- Jiekun Yang
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, 450 Ray C. Hunt Drive, Charlottesville, VA, 22903, USA
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SLEEPLESS is a bifunctional regulator of excitability and cholinergic synaptic transmission. Curr Biol 2014; 24:621-9. [PMID: 24613312 DOI: 10.1016/j.cub.2014.02.026] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 01/15/2014] [Accepted: 02/11/2014] [Indexed: 01/01/2023]
Abstract
BACKGROUND Although sleep is conserved throughout evolution, the molecular basis of its control is still largely a mystery. We previously showed that the quiver/sleepless (qvr/sss) gene encodes a membrane-tethered protein that is required for normal sleep in Drosophila. SLEEPLESS (SSS) protein functions, at least in part, by upregulating the levels and open probability of Shaker (Sh) potassium channels to suppress neuronal excitability and enable sleep. Consistent with this proposed mechanism, loss-of-function mutations in Sh phenocopy qvr/sss-null mutants. However, sleep is more genetically modifiable in Sh than in qvr/sss mutants, suggesting that SSS may regulate additional molecules to influence sleep. RESULTS Here we show that SSS also antagonizes nicotinic acetylcholine receptors (nAChRs) to reduce synaptic transmission and promote sleep. Mimicking this antagonism with the nAChR inhibitor mecamylamine or by RNAi knockdown of specific nAChR subunits is sufficient to restore sleep to qvr/sss mutants. Regulation of nAChR activity by SSS occurs posttranscriptionally, since the levels of nAChR mRNAs are unchanged in qvr/sss mutants. Regulation of nAChR activity by SSS may in fact be direct, since SSS forms a stable complex with and antagonizes nAChR function in transfected cells. Intriguingly, lynx1, a mammalian homolog of SSS, can partially restore normal sleep to qvr/sss mutants, and lynx1 can form stable complexes with Shaker-type channels and nAChRs. CONCLUSIONS Together, our data point to an evolutionarily conserved, bifunctional role for SSS and its homologs in controlling excitability and synaptic transmission in fundamental processes of the nervous system such as sleep.
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Molgó J, Aráoz R, Benoit E, Iorga BI. Physical and virtual screening methods for marine toxins and drug discovery targeting nicotinic acetylcholine receptors. Expert Opin Drug Discov 2013; 8:1203-23. [DOI: 10.1517/17460441.2013.822365] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Yang Z, Seneviratne C, Wang S, Ma JZ, Payne TJ, Wang J, Li MD. Serotonin transporter and receptor genes significantly impact nicotine dependence through genetic interactions in both European American and African American smokers. Drug Alcohol Depend 2013; 129:217-25. [PMID: 23290502 PMCID: PMC3628090 DOI: 10.1016/j.drugalcdep.2012.12.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 10/31/2012] [Accepted: 12/07/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Pharmacologic studies implicate a significant role of genes encoding the serotonin transporter (SLC6A4) and the 5-HT3AB subunits HTR3A and HTR3B in nicotine dependence (ND). However, whether they are involved in ND remains largely unknown. METHODS Here, we examined the impact of variations in the three genes on ND in 1366 individuals from 402 African American (AA) and 671 individuals from 200 European American (EA) families. The ND of each smoker was assessed with smoking quantity (SQ), heaviness of smoking index (HSI), and Fagerström test for nicotine dependence (FTND). RESULTS Association analysis revealed marginal association of rs10160548 in HTR3A with SQ and HSI in AA, 5-HTTLPR in SLC6A4 with FTND in EA, and rs11606194 in HTR3B with SQ and FTND in the pooled sample. Haplotype-based association analysis revealed a few major haplotypes in HTR3A that were significantly associated with ND in the AA, EA, and pooled samples. However, none of these associations remained significant after correcting for multiple testing except for a haplotype G-C-C-T-A-T formed by SNPs rs1150226, rs1062613, rs33940208, rs1985242, rs2276302, and rs10160548 in HTR3A for the AA sample. Considering biological functions of the three genes, we examined interactive effects of variants in the three genes, which revealed significant interactions among rs1062613 and rs10160548 in HTR3A, rs1176744 in HTR3B, and 5-HTTLPR and rs1042173 in SLC6A4 in affecting ND in the three samples. CONCLUSIONS We conclude that SLC6A4, HTR3A and HTR3B play a significant role in ND through genetic interactions.
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Affiliation(s)
- Zhongli Yang
- Shanxi Key Laboratory of Environmental Veterinary Science, Shanxi Agricultural University, Shanxi, China, Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, USA
| | - Chamindi Seneviratne
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, USA
| | - Shaolin Wang
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, USA
| | - Jennie Z. Ma
- Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA
| | - Thomas J. Payne
- ACT Center for Tobacco Treatment, Education and Research, Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Jundong Wang
- Shanxi Key Laboratory of Environmental Veterinary Science, Shanxi Agricultural University, Shanxi, China
| | - Ming D. Li
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, USA,Correspondence: Professor Ming D Li, Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, 1670 Discovery Drive, Suite 110, Charlottesville, VA 22911, USA. Tel: +1 434 243 0570; Fax: +1 434 973 7031;
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Kuryatov A, Mukherjee J, Lindstrom J. Chemical chaperones exceed the chaperone effects of RIC-3 in promoting assembly of functional α7 AChRs. PLoS One 2013; 8:e62246. [PMID: 23638015 PMCID: PMC3634732 DOI: 10.1371/journal.pone.0062246] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 03/19/2013] [Indexed: 02/02/2023] Open
Abstract
Functional α7 nicotinic acetylcholine receptors (AChRs) do not assemble efficiently in cells transfected with α7 subunits unless the cells are also transfected with the chaperone protein RIC-3. Despite the presence of RIC-3, large amounts of these subunits remain improperly assembled. Thus, additional chaperone proteins are probably required for efficient assembly of α7 AChRs. Cholinergic ligands can act as pharmacological chaperones to promote assembly of mature AChRs and upregulate the amount of functional AChRs. In addition, we have found that the chemical chaperones 4-phenylbutyric acid (PBA) and valproic acid (VPA) greatly increase the amount of functional α7 AChRs produced in a cell line expressing both α7 and RIC-3. Increased α7 AChR expression allows assay of drug action using a membrane potential-sensitive fluorescent indicator. Both PBA and VPA also increase α7 expression in the SH-SY5Y neuroblastoma cell line that endogenously expresses α7 AChRs. VPA increases expression of endogenous α7 AChRs in hippocampal neurons but PBA does not. RIC-3 is insufficient for optimal assembly of α7 AChRs, but provides assay conditions for detecting additional chaperones. Chemical chaperones are a useful pragmatic approach to express high levels of human α7 AChRs for drug selection and characterization and possibly to increase α7 expression in vivo.
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Affiliation(s)
- Alexander Kuryatov
- Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, Pennsylvania, United States of America
| | - Jayanta Mukherjee
- Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, Pennsylvania, United States of America
| | - Jon Lindstrom
- Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, Pennsylvania, United States of America
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An optimized fluorescent probe for visualizing glutamate neurotransmission. Nat Methods 2013; 10:162-70. [PMID: 23314171 PMCID: PMC4469972 DOI: 10.1038/nmeth.2333] [Citation(s) in RCA: 647] [Impact Index Per Article: 58.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 12/11/2012] [Indexed: 11/08/2022]
Abstract
We describe an intensity-based glutamate-sensing fluorescent reporter (iGluSnFR) with signal-to-noise ratio and kinetics appropriate for in vivo imaging. We engineered iGluSnFR in vitro to maximize its fluorescence change, and we validated its utility for visualizing glutamate release by neurons and astrocytes in increasingly intact neurological systems. In hippocampal culture, iGluSnFR detected single field stimulus-evoked glutamate release events. In pyramidal neurons in acute brain slices, glutamate uncaging at single spines showed that iGluSnFR responds robustly and specifically to glutamate in situ, and responses correlate with voltage changes. In mouse retina, iGluSnFR-expressing neurons showed intact light-evoked excitatory currents, and the sensor revealed tonic glutamate signaling in response to light stimuli. In worms, glutamate signals preceded and predicted postsynaptic calcium transients. In zebrafish, iGluSnFR revealed spatial organization of direction-selective synaptic activity in the optic tectum. Finally, in mouse forelimb motor cortex, iGluSnFR expression in layer V pyramidal neurons revealed task-dependent single-spine activity during running.
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Yamauchi JG, Gomez K, Grimster N, Dufouil M, Nemecz A, Fotsing JR, Ho KY, Talley TT, Sharpless KB, Fokin VV, Taylor P. Synthesis of selective agonists for the α7 nicotinic acetylcholine receptor with in situ click-chemistry on acetylcholine-binding protein templates. Mol Pharmacol 2012; 82:687-99. [PMID: 22784805 DOI: 10.1124/mol.112.080291] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The acetylcholine-binding proteins (AChBPs), which serve as structural surrogates for the extracellular domain of nicotinic acetylcholine receptors (nAChRs), were used as reaction templates for in situ click-chemistry reactions to generate a congeneric series of triazoles from azide and alkyne building blocks. The catalysis of in situ azide-alkyne cycloaddition reactions at a dynamic subunit interface facilitated the synthesis of potentially selective compounds for nAChRs. We investigated compound sets generated in situ with soluble AChBP templates through pharmacological characterization with α7 and α4β2 nAChRs and 5-hydroxytryptamine type 3A receptors. Analysis of activity differences between the triazole 1,5-syn- and 1,4-anti-isomers showed a preference for the 1,4-anti-triazole regioisomers among nAChRs. To improve nAChR subtype selectivity, the highest-potency building block for α7 nAChRs, i.e., 3α-azido-N-methylammonium tropane, was used for additional in situ reactions with a mutated Aplysia californica AChBP that was made to resemble the ligand-binding domain of the α7 nAChR. Fourteen of 50 possible triazole products were identified, and their corresponding tertiary analogs were synthesized. Pharmacological assays revealed that the mutated binding protein template provided enhanced selectivity of ligands through in situ reactions. Discrete trends in pharmacological profiles were evident, with most compounds emerging as α7 nAChR agonists and α4β2 nAChR antagonists. Triazoles bearing quaternary tropanes and aromatic groups were most potent for α7 nAChRs. Pharmacological characterization of the in situ reaction products established that click-chemistry synthesis with surrogate receptor templates offered novel extensions of fragment-based drug design that were applicable to multisubunit ion channels.
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Affiliation(s)
- John G Yamauchi
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
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Rojsanga P, Boonyarat C, Utsintong M, Nemecz Á, Yamauchi JG, Talley TT, Olson AJ, Matsumoto K, Vajragupta O. The effect of crebanine on memory and cognition impairment via the alpha-7 nicotinic acetylcholine receptor. Life Sci 2012; 91:107-14. [PMID: 22749860 DOI: 10.1016/j.lfs.2012.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 06/08/2012] [Accepted: 06/15/2012] [Indexed: 12/11/2022]
Abstract
AIMS The aims of the present study were to investigate the effect of crebanine on memory and cognition impairment in mice and to elucidate the underlying molecular mechanisms. MAIN METHODS The memory-enhancing effects of crebanine were assessed with a water maze test using scopolamine-induced amnesic mice. The molecular mechanism was explored in silico by docking crebanine against acetylcholine binding proteins (AChBPs) and in vitro with a radioligand competition assay using (±)-[(3)H]-epibatidine. The pharmacological behavior was assessed by observing changes to the functional activity of α7-nAChRs expressed in Xenopus oocytes and by fluorescent assays on recombinant ligand gated ion channel (LGIC) receptors expressed in mammalian cells. KEY FINDINGS The administration of crebanine significantly improved the cognitive deficits induced by scopolamine, as measured by the water maze test. The docking results demonstrated that crebanine bound to the active binding site of the AChBP template with a good docking energy. Crebanine significantly inhibited the binding of (±)-[(3)H]-epibatidine to AChBPs with K(i) values of 179 nM and 538 nM for Ls and Ac, respectively. Further functional assays performed using two separate protocols indicated that crebanine is an antagonist of the α7-nAChR with an IC(50) of 19.1μM. SIGNIFICANCE The observed actions of crebanine against amnesia and its effect on α7-nAChRs will be beneficial for target-based drug design; crebanine or its scaffold can be used as the starting point to develop a drug for Alzheimer's disease. The cognition-enhancing effects of crebanine and the underlying mechanism based on α7-nAChRs are consistent with its traditional use. These findings demonstrate the potential utility of crebanine in the development of neurodegenerative therapy.
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Affiliation(s)
- Piyanuch Rojsanga
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand
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Looger LL, Griesbeck O. Genetically encoded neural activity indicators. Curr Opin Neurobiol 2012; 22:18-23. [DOI: 10.1016/j.conb.2011.10.024] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 10/31/2011] [Indexed: 10/15/2022]
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Nemecz Á, Taylor P. Creating an α7 nicotinic acetylcholine recognition domain from the acetylcholine-binding protein: crystallographic and ligand selectivity analyses. J Biol Chem 2011; 286:42555-42565. [PMID: 22009746 DOI: 10.1074/jbc.m111.286583] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Determining the structure of the ligand-binding domain of the nicotinic acetylcholine receptor (nAChR) has been a long standing goal in the design of selective drugs useful in implicated diseases for this prevalent receptor family. Acetylcholine-binding proteins have proven to be valuable surrogates with structural similarity and sequence identity to the extracellular domain of the nicotinic receptor, yet these soluble proteins have their unique features and do not serve as exact replicates of the nAChRs of interest. Here we systematically modify the sequence of these proteins toward the homomeric human α7 nAChR. These chimeric proteins exhibit a shift in affinities to reflect α7 binding characteristics yet maintain expression levels and stability conducive for crystallization. We also present a pentameric humanoid nAChR extracellular domain with the structural determination of the α7 nAChR glycosylation site.
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Affiliation(s)
- Ákos Nemecz
- Departments of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0650; Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0650
| | - Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093-0650.
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Utsintong M, Rojsanga P, Ho KY, Talley TT, Olson AJ, Matsumoto K, Vajragupta O. Virtual screening against acetylcholine binding protein. ACTA ACUST UNITED AC 2011; 17:204-15. [PMID: 21956172 DOI: 10.1177/1087057111421667] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The nicotinic acetylcholine receptors (nAChRs) are a member of the ligand-gated ion channel family and play a key role in the transfer of information across neurological networks. The X-ray crystal structure of agonist-bound α(7) acetylcholine binding protein (AChBP) has been recognized as the most appropriate template to model the ligand-binding domain of nAChR for studying the molecular mechanism of the receptor-ligand interactions. Virtual screening of the National Cancer Institute diversity set, a library of 1990 compounds with nonredundant pharmacophore profiles, using AutoDock against AChBPs revealed 51 potential candidates. In vitro radioligand competition assays using [(3)H] epibatidine against the AChBPs from the freshwater snails, Lymnaea stagnalis, and from the marine species, Aplysia californica and the mutant (AcY55W), revealed seven compounds from the list of candidates that had micromolar to nanomolar affinities for the AChBPs. Further investigation on α(7)nAChR expressing in Xenopus oocytes and on the recombinant receptors with fluorescence resonance energy transfer (FRET)-based calcium sensor expressing in HEK cells showed that seven compounds were antagonists of α(7)nAChR, only one compound (NSC34352) demonstrated partial agonistic effect at low dose (10 µM), and two compounds (NSC36369 and NSC34352) were selective antagonists on α(7)nAchR with moderate potency. These hits serve as novel templates/scaffolds for development of more potent and specific in the AChR systems.
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Affiliation(s)
- Maleeruk Utsintong
- School of Pharmaceutical Sciences, University of Phayao, Phayao, Thailand
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