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Rakoczy RJ, Runge GN, Sen AK, Sandoval O, Wells HG, Nguyen Q, Roberts BR, Sciortino JH, Gibbons WJ, Friedberg LM, Jones JA, McMurray MS. Pharmacological and behavioural effects of tryptamines present in psilocybin-containing mushrooms. Br J Pharmacol 2024. [PMID: 38825326 DOI: 10.1111/bph.16466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/08/2024] [Indexed: 06/04/2024] Open
Abstract
BACKGROUND AND PURPOSE Demand for new antidepressants has resulted in a re-evaluation of the therapeutic potential of psychedelic drugs. Several tryptamines found in psilocybin-containing "magic" mushrooms share chemical similarities with psilocybin. Early work suggests they may share biological targets. However, few studies have explored their pharmacological and behavioural effects. EXPERIMENTAL APPROACH We compared baeocystin, norbaeocystin and aeruginascin with psilocybin to determine if they are metabolized by the same enzymes, similarly penetrate the blood-brain barrier, serve as ligands for similar receptors and modulate behaviour in rodents similarly. We also assessed the stability and optimal storage and handling conditions for each compound. KEY RESULTS In vitro enzyme kinetics assays found that all compounds had nearly identical rates of dephosphorylation via alkaline phosphatase and metabolism by monoamine oxidase. Further, we found that only the dephosphorylated products of baeocystin and norbaeocystin crossed a blood-brain barrier mimetic to a similar degree as the dephosphorylated form of psilocybin, psilocin. The dephosphorylated form of norbaeocystin was found to activate the 5-HT2A receptor with similar efficacy to psilocin and norpsilocin in in vitro cell imaging assays. Behaviourally, only psilocybin induced head twitch responses in rats, a marker of 5-HT2A-mediated psychedelic effects and hallucinogenic potential. However, like psilocybin, norbaeocystin improved outcomes in the forced swim test. All compounds caused minimal changes to metrics of renal and hepatic health, suggesting innocuous safety profiles. CONCLUSIONS AND IMPLICATIONS Collectively, this work suggests that other naturally occurring tryptamines, especially norbaeocystin, may share overlapping therapeutic potential with psilocybin, but without causing hallucinations.
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Affiliation(s)
- Ryan J Rakoczy
- Department of Psychology, Miami University, Oxford, Ohio, USA
| | - Grace N Runge
- Department of Psychology, Miami University, Oxford, Ohio, USA
| | - Abhishek K Sen
- Department of Chemical, Paper, and Biomedical Engineering, Miami University, Oxford, Ohio, USA
| | - Oscar Sandoval
- Department of Psychology, Miami University, Oxford, Ohio, USA
| | - Hunter G Wells
- Department of Psychology, Miami University, Oxford, Ohio, USA
| | - Quynh Nguyen
- Department of Chemical, Paper, and Biomedical Engineering, Miami University, Oxford, Ohio, USA
| | | | - Jon H Sciortino
- Department of Psychology, Miami University, Oxford, Ohio, USA
| | - William J Gibbons
- Department of Chemical, Paper, and Biomedical Engineering, Miami University, Oxford, Ohio, USA
| | - Lucas M Friedberg
- Department of Chemical, Paper, and Biomedical Engineering, Miami University, Oxford, Ohio, USA
| | - J Andrew Jones
- Department of Chemical, Paper, and Biomedical Engineering, Miami University, Oxford, Ohio, USA
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2
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Krishnan R, Kannan MS, Deshpande DA. Superoxide Anions Inhibit Intracellular Calcium Response in Porcine Airway Smooth Muscle Cells. AJP Rep 2024; 14:e162-e169. [PMID: 38784940 PMCID: PMC11115973 DOI: 10.1055/a-2318-0625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 04/25/2024] [Indexed: 05/25/2024] Open
Abstract
Background Superoxide anions (O 2 - ) have multiple effects on pulmonary parenchyma altering cell proliferation, cellular metabolism, and airway smooth muscle (ASM) contraction. Intracellular calcium ([Ca 2+ ] i ) concentration plays a significant role in the regulation of ASM contraction, relaxation, proliferation, and gene expression. Objective We investigated the effects of O 2 - on agonist-stimulated changes in [Ca 2+ ] i in ASM cells. Design/Methods Fura-2 AM-loaded, freshly isolated porcine ASM (PASM) cells were used to examine [Ca 2+ ] i release in response to acetylcholine (ACh), histamine, endothelin, caffeine, and thapsigargin (TPG) in the presence or absence of extracellular Ca 2+ . Results Exposure of PASM cells to xanthine and xanthine oxidase (X + XO) resulted in a time-dependent generation of O 2 - , inhibited by superoxide dismutase (SOD). Preincubating PASM cells with X + XO for 15- or 45-minute inhibited net [Ca 2+ ] i responses to ACh, histamine, caffeine, and TPG compared with control cells. Pretreating PASM cells with SOD for 30 minutes mitigated the inhibitory effect of X + XO treatment on ACh-induced Ca 2+ elevation suggesting role of O 2 - . X + XO treatment also inhibited caffeine- and TPG-induced Ca 2+ elevation suggesting effect of O 2 - on [Ca 2+ ] i release and reuptake mechanisms. Conclusion Superoxide attenuates [Ca 2+ ] i release, reuptake, and may interfere with physiological functions of ASM cells.
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Affiliation(s)
- Ramesh Krishnan
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Mathur S. Kannan
- Departments of Pediatrics and Veterinary Pathobiology, University of Minnesota, Minneapolis, Minnesota
| | - Deepak A. Deshpande
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
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Robinson SD, Deuis JR, Niu P, Touchard A, Mueller A, Schendel V, Brinkwirth N, King GF, Vetter I, Schmidt JO. Peptide toxins that target vertebrate voltage-gated sodium channels underly the painful stings of harvester ants. J Biol Chem 2024; 300:105577. [PMID: 38110035 PMCID: PMC10821600 DOI: 10.1016/j.jbc.2023.105577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/29/2023] [Accepted: 12/11/2023] [Indexed: 12/20/2023] Open
Abstract
Harvester ants (genus Pogonomyrmex) are renowned for their stings which cause intense, long-lasting pain, and other neurotoxic symptoms in vertebrates. Here, we show that harvester ant venoms are relatively simple and composed largely of peptide toxins. One class of peptides is primarily responsible for the long-lasting local pain of envenomation via activation of peripheral sensory neurons. These hydrophobic, cysteine-free peptides potently modulate mammalian voltage-gated sodium (NaV) channels, reducing the voltage threshold for activation and inhibiting channel inactivation. These toxins appear to have evolved specifically to deter vertebrates.
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Affiliation(s)
- Samuel D Robinson
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia.
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Pancong Niu
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Axel Touchard
- CNRS, UMR Ecologie des forêts de Guyane - EcoFoG (AgroParisTech, CIRAD, INRAE, Université de Guyane, Université des Antilles), Kourou, France
| | - Alexander Mueller
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia; Centro de Investigación Biomédica CENBIO, Universidad UTE, Quito, Ecuador
| | - Vanessa Schendel
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | | | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia; Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Queensland, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia; School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia
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4
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McMahon KL, O'Brien H, Schroeder CI, Deuis JR, Venkatachalam D, Huang D, Green BR, Bandyopadhyay PK, Li Q, Yandell M, Safavi-Hemami H, Olivera BM, Vetter I, Robinson SD. Identification of sodium channel toxins from marine cone snails of the subgenera Textilia and Afonsoconus. Cell Mol Life Sci 2023; 80:287. [PMID: 37689602 PMCID: PMC10492761 DOI: 10.1007/s00018-023-04935-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/20/2023] [Accepted: 08/22/2023] [Indexed: 09/11/2023]
Abstract
Voltage-gated sodium (NaV) channels are transmembrane proteins that play a critical role in electrical signaling in the nervous system and other excitable tissues. µ-Conotoxins are peptide toxins from the venoms of marine cone snails (genus Conus) that block NaV channels with nanomolar potency. Most species of the subgenera Textilia and Afonsoconus are difficult to acquire; therefore, their venoms have yet to be comprehensively interrogated for µ-conotoxins. The goal of this study was to find new µ-conotoxins from species of the subgenera Textilia and Afonsoconus and investigate their selectivity at human NaV channels. Using RNA-seq of the venom gland of Conus (Textilia) bullatus, we identified 12 µ-conotoxin (or µ-conotoxin-like) sequences. Based on these sequences we designed primers which we used to identify additional µ-conotoxin sequences from DNA extracted from historical specimens of species from Textilia and Afonsoconus. We synthesized six of these µ-conotoxins and tested their activity on human NaV1.1-NaV1.8. Five of the six synthetic peptides were potent blockers of human NaV channels. Of these, two peptides (BuIIIB and BuIIIE) were potent blockers of hNaV1.3. Three of the peptides (BuIIIB, BuIIIE and AdIIIA) had submicromolar activity at hNaV1.7. This study serves as an example of the identification of new peptide toxins from historical DNA and provides new insights into structure-activity relationships of µ-conotoxins with activity at hNaV1.3 and hNaV1.7.
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Affiliation(s)
- Kirsten L McMahon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Henrik O'Brien
- Biology Department, University of Utah, Salt Lake City, UT, 84112, USA
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
- Peptide Therapeutics, Genentech, 1 DNA Way, South San Francisco, CA, 94080, USA
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | | | - Di Huang
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Brad R Green
- Biology Department, University of Utah, Salt Lake City, UT, 84112, USA
| | | | - Qing Li
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT, 84112, USA
- Cancer Bioinformatics, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, 84112, USA
| | - Mark Yandell
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT, 84112, USA
| | | | | | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Samuel D Robinson
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia.
- Biology Department, University of Utah, Salt Lake City, UT, 84112, USA.
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Galante P, Campos GAA, Moser JCG, Martins DB, Dos Santos Cabrera MP, Rangel M, Coelho LC, Simon KS, Amado VM, de A I Muller J, Koehbach J, Lohman RJ, Cabot PJ, Vetter I, Craik DJ, Toffoli-Kadri MC, Monge-Fuentes V, Goulart JT, Schwartz EF, Silva LP, Bocca AL, Mortari MR. Exploring the therapeutic potential of an antinociceptive and anti-inflammatory peptide from wasp venom. Sci Rep 2023; 13:12491. [PMID: 37528129 PMCID: PMC10393941 DOI: 10.1038/s41598-023-38828-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 07/16/2023] [Indexed: 08/03/2023] Open
Abstract
Animal venoms are rich sources of neuroactive compounds, including anti-inflammatory, antiepileptic, and antinociceptive molecules. Our study identified a protonectin peptide from the wasp Parachartergus fraternus' venom using mass spectrometry and cDNA library construction. Using this peptide as a template, we designed a new peptide, protonectin-F, which exhibited higher antinociceptive activity and less motor impairment compared to protonectin. In drug interaction experiments with naloxone and AM251, Protonectin-F's activity was decreased by opioid and cannabinoid antagonism, two critical antinociception pathways. Further experiments revealed that this effect is most likely not induced by direct action on receptors but by activation of the descending pain control pathway. We noted that protonectin-F induced less tolerance in mice after repeated administration than morphine. Protonectin-F was also able to decrease TNF-α production in vitro and modulate the inflammatory response, which can further contribute to its antinociceptive activity. These findings suggest that protonectin-F may be a potential molecule for developing drugs to treat pain disorders with fewer adverse effects. Our results reinforce the biotechnological importance of animal venom for developing new molecules of clinical interest.
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Affiliation(s)
- Priscilla Galante
- Laboratory of Neuropharmacology, Department of Physiological Sciences, University of Brasília, Brasília, DF, 70910-900, Brazil
| | - Gabriel A A Campos
- Laboratory of Neuropharmacology, Department of Physiological Sciences, University of Brasília, Brasília, DF, 70910-900, Brazil
| | - Jacqueline C G Moser
- Laboratory of Neuropharmacology, Department of Physiological Sciences, University of Brasília, Brasília, DF, 70910-900, Brazil
| | - Danubia B Martins
- Department of Physics, IBILCE, São Paulo State University, São José do Rio Preto, SP, 15054-000, Brazil
| | | | - Marisa Rangel
- Immunopathology Laboratory, Butantan Institute, Sao Paulo, SP, 05503-900, Brazil
| | - Luiza C Coelho
- Laboratory of Applied Immunology, Department of Cell Biology, University of Brasilia, Brasilia, DF, 70910-900, Brazil
| | - Karina S Simon
- Laboratory of Applied Immunology, Department of Cell Biology, University of Brasilia, Brasilia, DF, 70910-900, Brazil
| | - Veronica M Amado
- Faculty of Medicine and University Hospital of Brasília, University of Brasilia, Brasilia, DF, 79910-900, Brazil
| | - Jessica de A I Muller
- Laboratory of Pharmacology and Inflammation FACFAN, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, 79070-900, Brazil
| | - Johannes Koehbach
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Rink-Jan Lohman
- School of Pharmacy, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Peter J Cabot
- School of Pharmacy, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - David J Craik
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Monica C Toffoli-Kadri
- Laboratory of Pharmacology and Inflammation FACFAN, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, 79070-900, Brazil
| | - Victoria Monge-Fuentes
- Laboratory of Neuropharmacology, Department of Physiological Sciences, University of Brasília, Brasília, DF, 70910-900, Brazil
| | - Jair T Goulart
- Laboratory of Neuropharmacology, Department of Physiological Sciences, University of Brasília, Brasília, DF, 70910-900, Brazil
| | - Elisabeth F Schwartz
- Laboratory of Neuropharmacology, Department of Physiological Sciences, University of Brasília, Brasília, DF, 70910-900, Brazil
| | - Luciano P Silva
- Laboratory of Nanobiotechnology, Embrapa Genetic Resources and Biotechnology, Brasília, DF, 70770917, Brazil
| | - Anamelia L Bocca
- Laboratory of Applied Immunology, Department of Cell Biology, University of Brasilia, Brasilia, DF, 70910-900, Brazil
| | - Márcia R Mortari
- Laboratory of Neuropharmacology, Department of Physiological Sciences, University of Brasília, Brasília, DF, 70910-900, Brazil.
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Laksono RM, Kalim H, Rohman MS, Widodo N, Ahmad MR, Halim W. Pulsed Radiofrequency Decreases pERK and Affects Intracellular Ca 2+ Influx, Cytosolic ATP Level, and Mitochondrial Membrane Potential in the Sensitized Dorsal Root Ganglion Neuron Induced by N-Methyl D-Aspartate. J Pain Res 2023; 16:1697-1711. [PMID: 37252110 PMCID: PMC10216856 DOI: 10.2147/jpr.s409658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/08/2023] [Indexed: 05/31/2023] Open
Abstract
Background The molecular mechanism of pulsed radiofrequency (PRF) in chronic pain management is not fully understood. Chronic pain involves the activation of specific N-Methyl D-Aspartate receptors (NMDAR) to induce central sensitization. This study aims to determine the effect of PRF on central sensitization biomarker phosphorylated extracellular signal-regulated kinase (pERK), Ca2+ influx, cytosolic ATP level, and mitochondrial membrane potential (Δψm) of the sensitized dorsal root ganglion (DRG) neuron following NMDAR activation. Methods This study is a true experimental in-vitro study on a sensitized DRG neuron induced with 80 µM NMDA. There are six treatment groups including control, NMDA 80 µM, Ketamine 100 µM, PRF 2Hz, NMDA 80 µM + PRF 2 Hz, and NMDA 80 µM + PRF 2 Hz + ketamine 100 µM. We use PRF 2 Hz 20 ms for 360 seconds. Statistical analysis was performed using the One-Way ANOVA and the Pearson correlation test with α=5%. Results In the sensitized DRG neuron, there is a significant elevation of pERK. There is a strong correlation between Ca2+, cytosolic ATP level, and Δψm with pERK intensity (p<0.05). PRF treatment decreases pERK intensity from 108.48 ± 16.95 AU to 38.57 ± 5.20 AU (p<0.05). PRF exposure to sensitized neurons also exhibits a Ca2+ influx, but still lower than in the unexposed neuron. PRF exposure in sensitized neurons has a higher cytosolic ATP level (0.0458 ± 0.0010 mM) than in the unexposed sensitized neuron (0.0198 ± 0.0004 mM) (p<0.05). PRF also decreases Δψm in the sensitized neuron from 109.24 ± 6.43 AU to 33.21 ± 1.769 AU (p<0.05). Conclusion PRF mechanisms related to DRG neuron sensitization are by decreasing pERK, altering Ca2+ influx, increasing cytosolic ATP level, and decreasing Δψm which is associated with neuron sensitization following NMDAR activation.
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Affiliation(s)
- Ristiawan Muji Laksono
- Doctoral Program in Biomedical Science, Faculty of Medicine, Brawijaya University, Malang, Indonesia
- Department of Anesthesiology and Intensive Therapy, Faculty of Medicine, Brawijaya University, Malang, Indonesia
| | - Handono Kalim
- Department of Internal Medicine, Faculty of Medicine, Brawijaya University, Malang, Indonesia
| | - Mohammad Saifur Rohman
- Department of Cardiology and Vascular Medicine, Faculty of Medicine, Brawijaya University, Malang, Indonesia
| | - Nashi Widodo
- Department of Biology, Faculty of Mathematics and Natural Science, Brawijaya University, Malang, Indonesia
| | - Muhammad Ramli Ahmad
- Department of Anesthesiology, Intensive Care and Pain Management, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Willy Halim
- Faculty of Medicine, Brawijaya University, Malang, Indonesia
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7
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A bivalent remipede toxin promotes calcium release via ryanodine receptor activation. Nat Commun 2023; 14:1036. [PMID: 36823422 PMCID: PMC9950431 DOI: 10.1038/s41467-023-36579-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 02/07/2023] [Indexed: 02/25/2023] Open
Abstract
Multivalent ligands of ion channels have proven to be both very rare and highly valuable in yielding unique insights into channel structure and pharmacology. Here, we describe a bivalent peptide from the venom of Xibalbanus tulumensis, a troglobitic arthropod from the enigmatic class Remipedia, that causes persistent calcium release by activation of ion channels involved in muscle contraction. The high-resolution solution structure of φ-Xibalbin3-Xt3a reveals a tandem repeat arrangement of inhibitor-cysteine knot (ICK) domains previously only found in spider venoms. The individual repeats of Xt3a share sequence similarity with a family of scorpion toxins that target ryanodine receptors (RyR). Single-channel electrophysiology and quantification of released Ca2+ stores within skinned muscle fibers confirm Xt3a as a bivalent RyR modulator. Our results reveal convergent evolution of RyR targeting toxins in remipede and scorpion venoms, while the tandem-ICK repeat architecture is an evolutionary innovation that is convergent with toxins from spider venoms.
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8
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Campbell EP, Abushawish AA, Valdez LA, Bell MK, Haryono M, Rangamani P, Bloodgood BL. Electrical signals in the ER are cell type and stimulus specific with extreme spatial compartmentalization in neurons. Cell Rep 2023; 42:111943. [PMID: 36640310 PMCID: PMC10033362 DOI: 10.1016/j.celrep.2022.111943] [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: 01/12/2022] [Revised: 10/04/2022] [Accepted: 12/15/2022] [Indexed: 01/06/2023] Open
Abstract
The endoplasmic reticulum (ER) is a tortuous organelle that spans throughout a cell with a continuous membrane containing ion channels, pumps, and transporters. It is unclear if stimuli that gate ER ion channels trigger substantial membrane potential fluctuations and if those fluctuations spread beyond their site of origin. Here, we visualize ER membrane potential dynamics in HEK cells and cultured rat hippocampal neurons by targeting a genetically encoded voltage indicator specifically to the ER membrane. We report the existence of clear cell-type- and stimulus-specific ER membrane potential fluctuations. In neurons, direct stimulation of ER ryanodine receptors generates depolarizations that scale linearly with stimulus strength and reach tens of millivolts. However, ER potentials do not spread beyond the site of receptor activation, exhibiting steep attenuation that is exacerbated by intracellular large conductance K+ channels. Thus, segments of ER can generate large depolarizations that are actively restricted from impacting nearby, contiguous membrane.
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Affiliation(s)
- Evan P Campbell
- Neurobiology Department, School of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Ahmed A Abushawish
- Neurobiology Department, School of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Lauren A Valdez
- Neurobiology Department, School of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Miriam K Bell
- Department of Mechanical and Aerospace Engineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Melita Haryono
- Neurobiology Department, School of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Brenda L Bloodgood
- Neurobiology Department, School of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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9
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Robinson SD, Schendel V, Schroeder CI, Moen S, Mueller A, Walker AA, McKinnon N, Neely GG, Vetter I, King GF, Undheim EAB. Intra-colony venom diversity contributes to maintaining eusociality in a cooperatively breeding ant. BMC Biol 2023; 21:5. [PMID: 36617555 PMCID: PMC9827630 DOI: 10.1186/s12915-022-01507-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 12/19/2022] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Eusociality is widely considered to evolve through kin selection, where the reproductive success of an individual's close relative is favored at the expense of its own. High genetic relatedness is thus considered a prerequisite for eusociality. While ants are textbook examples of eusocial animals, not all ants form colonies of closely related individuals. One such example is the ectatommine ant Rhytidoponera metallica, which predominantly forms queen-less colonies that have such a low intra-colony relatedness that they have been proposed to represent a transient, unstable form of eusociality. However, R. metallica is among the most abundant and widespread ants on the Australian continent. This apparent contradiction provides an example of how inclusive fitness may not by itself explain the maintenance of eusociality and raises the question of what other selective advantages maintain the eusocial lifestyle of this species. RESULTS We provide a comprehensive portrait of the venom of R. metallica and show that the colony-wide venom consists of an exceptionally high diversity of functionally distinct toxins for an ant. These toxins have evolved under strong positive selection, which is normally expected to reduce genetic variance. Yet, R. metallica exhibits remarkable intra-colony variation, with workers sharing only a relatively small proportion of toxins in their venoms. This variation is not due to the presence of chemical castes, but has a genetic foundation that is at least in part explained by toxin allelic diversity. CONCLUSIONS Taken together, our results suggest that the toxin diversity contained in R. metallica colonies may be maintained by a form of group selection that selects for colonies that can exploit more resources and defend against a wider range of predators. We propose that increased intra-colony genetic variance resulting from low kinship may itself provide a selective advantage in the form of an expanded pharmacological venom repertoire. These findings provide an example of how group selection on adaptive phenotypes may contribute to maintaining eusociality where a prerequisite for kin selection is diminished.
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Affiliation(s)
- Samuel D. Robinson
- grid.1003.20000 0000 9320 7537Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
| | - Vanessa Schendel
- grid.1003.20000 0000 9320 7537Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
| | - Christina I. Schroeder
- grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia ,Present Address: Genentech, 1 DNA Way, South San Francisco, CA 94080 USA
| | - Sarah Moen
- grid.1003.20000 0000 9320 7537Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072 Australia
| | - Alexander Mueller
- grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
| | - Andrew A. Walker
- grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
| | - Naomi McKinnon
- grid.1013.30000 0004 1936 834XDr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre, Centenary Institute, and School of Life and Environmental Sciences, University of Sydney, Sydney, NSW Australia
| | - G. Gregory Neely
- grid.1013.30000 0004 1936 834XDr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre, Centenary Institute, and School of Life and Environmental Sciences, University of Sydney, Sydney, NSW Australia
| | - Irina Vetter
- grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102 Australia
| | - Glenn F. King
- grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia
| | - Eivind A. B. Undheim
- grid.1003.20000 0000 9320 7537Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072 Australia ,grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072 Australia ,grid.5510.10000 0004 1936 8921Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, 0316 Oslo, Norway
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10
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Freer M, Darling N, Goncalves K, Mills KJ, Przyborski S. Development of a mammalian neurosensory full‐thickness skin equivalent and its application to screen sensitizing stimuli. Bioeng Transl Med 2023; 8:e10484. [DOI: 10.1002/btm2.10484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/06/2022] [Accepted: 12/21/2022] [Indexed: 01/04/2023] Open
Affiliation(s)
- Matthew Freer
- Department of Biosciences Durham University Durham UK
| | | | | | | | - Stefan Przyborski
- Department of Biosciences Durham University Durham UK
- Reprocell Europe Ltd Glasgow UK
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11
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Shin SM, Baek EJ, Oh DY, Kim KH, Kim KJ, Park EJ. Functional validation of co-culture model of human keratinocytes and neuronal cell line for sensitive skin by using transient receptor potential channel vanilloid subfamily member 1 antagonist. Skin Res Technol 2023; 29:e13275. [PMID: 36704884 PMCID: PMC9838752 DOI: 10.1111/srt.13275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 12/23/2022] [Indexed: 01/11/2023]
Abstract
BACKGROUND Sensitive skin is a subjective cutaneous hyper-reactivity that occurs in response to various innocuous stimuli. Keratinocytes have recently been shown to participate in sensory transduction by releasing many neuroactive molecules that bind to intra-epidermal free nerve endings and modulate nociception. In the literature, the characterization of these interactions has been based on the co-culture of keratinocyte and mammalian-origin neuronal cell lines. In this study, we established an in vitro model based on a co-culture of primary human keratinocytes and differentiated SH-SY5Y cells, a human neuronal cell line. METHODS Human epidermal keratinocytes and SH-SY5Y cells were monocultured and co-cultured. Changes in calcium influx, substance P, inflammatory cytokines, and neuropeptides between the monoculture and co-culture groups treated with capsaicin only and capsaicin with transient receptor potential channel vanilloid subfamily member 1 (TRPV1) antagonist, trans-4-tert-butylcyclohexanol (TTBC), together. In addition, the difference in stinging sensation was evaluated by applying it to the volunteers. RESULTS When SH-SY5Y cells were co-cultured with keratinocytes, they had no significant effect on axonal development. Substance P was also released after capsaicin treatment and reduced by TTBC under co-culture conditions. Moreover, the expression of inflammatory cytokines and neuropeptides was significantly increased in co-cultured keratinocytes compared to that under monoculture conditions. In addition, the stinging sensation was significantly induced after the application of capsaicin in vivo and was relieved after the application of the TRPV1 antagonist. CONCLUSION We demonstrated that the novel co-culture model is functionally valid through capsaicin and TRPV1 antagonist. We also confirmed that TTBC could be used for the treatment of sensitive skin through a co-culture model and in vivo tests. This co-culture model of keratinocytes and SH-SY5Y cells may be useful in vitro alternatives for studying the close communication between keratinocytes and neuronal cells and for screening therapeutic drugs for sensitive skin.
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Affiliation(s)
- Sun Mee Shin
- Department of Dermatology, Hallym Institute for Translational Medicine, Anyang, Korea
| | - Eun Joo Baek
- Department of Dermatology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Dong Yeol Oh
- Department of Dermatology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Kwang Ho Kim
- Department of Dermatology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Kwang Joong Kim
- Department of Dermatology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Eun Joo Park
- Department of Dermatology, Hallym University Sacred Heart Hospital, Anyang, Korea
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12
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Venom composition and pain-causing toxins of the Australian great carpenter bee Xylocopa aruana. Sci Rep 2022; 12:22168. [PMID: 36550366 PMCID: PMC9780326 DOI: 10.1038/s41598-022-26867-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022] Open
Abstract
Most species of bee are capable of delivering a defensive sting which is often painful. A solitary lifestyle is the ancestral state of bees and most extant species are solitary, but information on bee venoms comes predominantly from studies on eusocial species. In this study we investigated the venom composition of the Australian great carpenter bee, Xylocopa aruana Ritsema, 1876. We show that the venom is relatively simple, composed mainly of one small amphipathic peptide (XYTX1-Xa1a), with lesser amounts of an apamin homologue (XYTX2-Xa2a) and a venom phospholipase-A2 (PLA2). XYTX1-Xa1a is homologous to, and shares a similar mode-of-action to melittin and the bombilitins, the major components of the venoms of the eusocial Apis mellifera (Western honeybee) and Bombus spp. (bumblebee), respectively. XYTX1-Xa1a and melittin directly activate mammalian sensory neurons and cause spontaneous pain behaviours in vivo, effects which are potentiated in the presence of venom PLA2. The apamin-like peptide XYTX2-Xa2a was a relatively weak blocker of small conductance calcium-activated potassium (KCa) channels and, like A. mellifera apamin and mast cell-degranulating peptide, did not contribute to pain behaviours in mice. While the composition and mode-of-action of the venom of X. aruana are similar to that of A. mellifera, the greater potency, on mammalian sensory neurons, of the major pain-causing component in A. mellifera venom may represent an adaptation to the distinct defensive pressures on eusocial Apidae.
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13
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Zhang J, Yuan H, Yao X, Chen S. Endogenous ion channels expressed in human embryonic kidney (HEK-293) cells. Pflugers Arch 2022; 474:665-680. [PMID: 35567642 DOI: 10.1007/s00424-022-02700-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/25/2022] [Accepted: 04/30/2022] [Indexed: 12/21/2022]
Abstract
Mammalian expression systems, particularly the human embryonic kidney (HEK-293) cells, combined with electrophysiological studies, have greatly benefited our understanding of the function, characteristic, and regulation of various ion channels. It was previously assumed that the existence of endogenous ion channels in native HEK-293 cells could be negligible. Still, more and more ion channels are gradually reported in native HEK-293 cells, which should draw our attention. In this regard, we summarize the different ion channels that are endogenously expressed in HEK-293 cells, including voltage-gated Na+ channels, Ca2+ channels, K+ channels, Cl- channels, nonselective cation channels, TRP channels, acid-sensitive ion channels, and Piezo channels, which may complicate the recording of the heterogeneously expressed ion channels to a certain degree. We noted that the expression patterns and channel profiles varied with different studies, which may be due to the distinct originality of the cells, cell culture conditions, passage numbers, and different recording protocols. Therefore, a better knowledge of endogenous ion channels may help minimize potential problems in characterizing heterologously expressed ion channels. Based on this, it is recommended that HEK-293 cells from unknown sources should be examined before transfection for the characterization of their functional profile, especially when the expression level of exogenous ion channels does not overwhelm the endogenous ion channels largely, or the current amplitude is not significantly higher than the native currents.
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Affiliation(s)
- Jun Zhang
- School of Biomedical Sciences and Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong, China
| | - Huikai Yuan
- Department of General Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xiaoqiang Yao
- School of Biomedical Sciences and Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong, China
| | - Shuo Chen
- Department of Biopharmaceutical Sciences, School of Pharmacy, Harbin Medical University at Daqing, No. 39 Xinyang Rd, High-tech District, Daqing, 163319, Heilongjiang Province, China.
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14
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Bertagna F, Lewis R, Silva SRP, McFadden J, Jeevaratnam K. Thapsigargin blocks electromagnetic field-elicited intracellular Ca 2+ increase in HEK 293 cells. Physiol Rep 2022; 10:e15189. [PMID: 35510320 PMCID: PMC9069166 DOI: 10.14814/phy2.15189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 11/24/2022] Open
Abstract
Biological effects of electromagnetic fields (EMFs) have previously been identified for cellular proliferation and changes in expression and conduction of diverse types of ion channels. The major effect elicited by EMFs seems to be directed toward Ca2+ homeostasis. This is particularly remarkable since Ca2+ acts as a central modulator in various signaling pathways, including, but not limited to, cell differentiation and survival. Despite this, the mechanisms underlying this modulation have yet to be unraveled. Here, we assessed the effect of EMFs on intracellular [Ca2+], by exposing HEK 293 cells to both radio‐frequency electromagnetic fields (RF‐EMFs) and static magnetic fields (SMFs). We detected a constant and significant increase in [Ca2+] subsequent to exposure to both types of fields. Strikingly, the increase was nulled by administration of 10 μM Thapsigargin, a blocker of sarco/endoplasmic reticulum Ca2+‐ATPases (SERCAs), indicating the involvement of the endoplasmic reticulum (ER) in EMF‐related modulation of Ca2+ homeostasis.
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Affiliation(s)
- Federico Bertagna
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.,School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - Rebecca Lewis
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.,School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - S Ravi P Silva
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.,Advanced Technology Institute, University of Surrey, Guildford, Surrey, UK
| | - Johnjoe McFadden
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.,School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - Kamalan Jeevaratnam
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.,School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
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15
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Cardoso FC, Schmit M, Kuiper MJ, Lewis RJ, Tuck KL, Duggan PJ. Inhibition of N-type calcium ion channels by tricyclic antidepressants - experimental and theoretical justification for their use for neuropathic pain. RSC Med Chem 2022; 13:183-195. [PMID: 35308021 PMCID: PMC8864487 DOI: 10.1039/d1md00331c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 12/20/2021] [Indexed: 11/21/2022] Open
Abstract
A number of tricyclic antidepressants (TCAs) are commonly prescribed off-label for the treatment of neuropathic pain. The blockade of neuronal calcium ion channels is often invoked to partially explain the analgesic activity of TCAs, but there has been very limited experimental or theoretical evidence reported to support this assertion. The N-type calcium ion channel (CaV2.2) is a well-established target for the treatment of neuropathic pain and in this study a series of eleven TCAs and two closely related drugs were shown to be moderately effective inhibitors of this channel when endogenously expressed in the SH-SY5Y neuroblastoma cell line. A homology model of the channel, which matches closely a recently reported Cryo-EM structure, was used to investigate via docking and molecular dynamics experiments the possible mode of inhibition of CaV2.2 channels by TCAs. Two closely related binding modes, that occur in the channel cavity that exists between the selectivity filter and the internal gate, were identified. The TCAs are predicted to position themselves such that their ammonium side chains interfere with the selectivity filter, with some, such as amitriptyline, also appearing to hinder the channel's ability to open. This study provides the most comprehensive evidence to date that supports the notion that the blockade of neuronal calcium ion channels by TCAs is at least partially responsible for their analgesic effect.
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Affiliation(s)
- Fernanda C Cardoso
- Institute for Molecular Bioscience, The University of Queensland St Lucia QLD 4072 Australia
| | - Matthieu Schmit
- School of Chemistry, Monash University Victoria 3800 Australia
- CSIRO Manufacturing Research Way Clayton Victoria 3168 Australia
| | | | - Richard J Lewis
- Institute for Molecular Bioscience, The University of Queensland St Lucia QLD 4072 Australia
| | - Kellie L Tuck
- School of Chemistry, Monash University Victoria 3800 Australia
| | - Peter J Duggan
- CSIRO Manufacturing Research Way Clayton Victoria 3168 Australia
- College of Science and Engineering, Flinders University Adelaide South Australia 5042 Australia
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16
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Ho TNT, Abraham N, Lewis RJ. Unique Pharmacological Properties of α-Conotoxin OmIA at α7 nAChRs. Front Pharmacol 2021; 12:803397. [PMID: 34955864 PMCID: PMC8692984 DOI: 10.3389/fphar.2021.803397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
OmIA, isolated from Conus omaria venom, is a potent antagonist at α7 nAChRs. We determined the co-crystal structure of OmIA with Lymnae stagnalis acetylcholine binding protein (Ls-AChBP) that identified His5, Val10 and Asn11 as key determinants for the high potency of OmIA at α7 nAChRs. Remarkably, despite a competitive binding mode observed in the co-crystal structure, OmIA and analogues displayed functional insurmountable antagonism at α7 and α3β4 nAChRs, except OmIA analogues having long side chain at position 10 ([V10Q]OmIA and [V10L]OmIA), which were partial insurmountable antagonist at α7 nAChRs in the presence of type II positive allosteric modulators (PAMs). A “two-state, two-step” model was used to explain these observations, with [V10Q]OmIA and [V10L]OmIA co-existing in a fast reversible/surmountable as well as a tight binding/insurmountable state. OmIA and analogues also showed biphasic-inhibition at α7 nAChRs in the presence of PNU120596, with a preference for the high-affinity binding site following prolonged exposure. The molecular basis of binding and complex pharmacological profile of OmIA at α7 nAChRs presented in here expands on the potential of α-conotoxins to probe the pharmacological properties of nAChRs and may help guide the development novel α7 modulators.
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Affiliation(s)
- Thao N T Ho
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Nikita Abraham
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Richard J Lewis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
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17
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Robinson SD, Kambanis L, Clayton D, Hinneburg H, Corcilius L, Mueller A, Walker AA, Keramidas A, Kulkarni SS, Jones A, Vetter I, Thaysen-Andersen M, Payne RJ, King GF, Undheim EAB. A pain-causing and paralytic ant venom glycopeptide. iScience 2021; 24:103175. [PMID: 34693225 PMCID: PMC8517206 DOI: 10.1016/j.isci.2021.103175] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/07/2021] [Accepted: 09/22/2021] [Indexed: 11/26/2022] Open
Abstract
Ants (Hymenoptera: Formicidae) are familiar inhabitants of most terrestrial environments. Although we are aware of the ability of many species to sting, knowledge of ant venom chemistry remains limited. Herein, we describe the discovery and characterization of an O-linked glycopeptide (Mg7a) as a major component of the venom of the ant Myrmecia gulosa. Electron transfer dissociation and higher-energy collisional dissociation tandem mass spectrometry were used to localize three α-N-acetylgalactosaminyl residues (α-GalNAc) present on the 63-residue peptide. To allow for functional studies, we synthesized the full-length glycosylated peptide via solid-phase peptide synthesis, combined with diselenide-selenoester ligation-deselenization chemistry. We show that Mg7a is paralytic and lethal to insects, and triggers pain behavior and inflammation in mammals, which it achieves through a membrane-targeting mode of action. Deglycosylation of Mg7a renders it insoluble in aqueous solution, suggesting a key solubilizing role of the O-glycans.
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Affiliation(s)
- Samuel D Robinson
- Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia.,Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Lucas Kambanis
- School of Chemistry, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Daniel Clayton
- School of Chemistry, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Hannes Hinneburg
- Department of Molecular Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia
| | - Leo Corcilius
- School of Chemistry, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Alexander Mueller
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Andrew A Walker
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Angelo Keramidas
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Sameer S Kulkarni
- School of Chemistry, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Alun Jones
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | | | - Richard J Payne
- School of Chemistry, The University of Sydney, Camperdown, NSW 2006, Australia.,ARC Centre of Excellence for Innovations in Peptide and Protein Science, St Lucia, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia.,ARC Centre of Excellence for Innovations in Peptide and Protein Science, St Lucia, Australia
| | - Eivind A B Undheim
- Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia.,Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia.,Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.,Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, The University of Oslo, 0316 Oslo, Norway
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18
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Dusan M, Jastrow C, Alyce MM, Yingkai W, Shashikanth M, Andelain E, Christine BM, Stuart BM, Oliver BG, Michael MZ, Nicolas VH, Damien KJ, Rainer HV. Differentiation of the 50B11 dorsal ganglion cells into NGF and GDNF responsive nociceptor subtypes. Mol Pain 2021; 16:1744806920970368. [PMID: 33307981 PMCID: PMC7745567 DOI: 10.1177/1744806920970368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The embryonic rat dorsal root ganglion (DRG) neuron-derived 50B11 cell line is a promising sensory neuron model expressing markers characteristic of NGF and GDNF-dependent C-fibre nociceptors. Whether these cells have the capacity to develop into distinct nociceptive subtypes based on NGF- or GDNF-dependence has not been investigated. Here we show that by augmenting forskolin (FSK) and growth factor supplementation with NGF or GDNF, 50B11 cultures can be driven to acquire differential functional responses to common nociceptive agonists capsaicin and ATP respectively. In addition, to previous studies, we also demonstrate that a differentiated neuronal phenotype can be maintained for up to 7 days. Western blot analysis of nociceptive marker proteins further demonstrates that the 50B11 cells partially recapitulate the functional phenotypes of classical NGF-dependent (peptidergic) and GDNF-dependent (non-peptidergic) neuronal subtypes described in DRGs. Further, 50B11 cells differentiated with NGF/FSK, but not GDNF/FSK, show sensitization to acute prostaglandin E2 treatment. Finally, RNA-Seq analysis confirms that differentiation with NGF/FSK or GDNF/FSK produces two 50B11 cell subtypes with distinct transcriptome expression profiles. Gene ontology comparison of the two subtypes of differentiated 50B11 cells to rodent DRG neurons studies shows significant overlap in matching or partially matching categories. This transcriptomic analysis will aid future suitability assessment of the 50B11 cells as a high-throughput nociceptor model for a broad range of experimental applications. In conclusion, this study shows that the 50B11 cell line is capable of partially recapitulating features of two distinct types of embryonic NGF and GDNF-dependent nociceptor-like cells.
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Affiliation(s)
- Matusica Dusan
- Anatomy and Histology, Flinders Health & Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Canlas Jastrow
- Anatomy and Histology, Flinders Health & Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Martin M Alyce
- Human Physiology, Flinders Health & Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Wei Yingkai
- Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University and Medical Centre, Bedford Park, Adelaide, South Australia, Australia
| | - Marri Shashikanth
- Visceral Pain Research Group, College of Medicine and Public Health, South Australian Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Erickson Andelain
- Flow Cytometry Facility, Department of Molecular Medicine and Genetics, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Barry M Christine
- Anatomy and Histology, Flinders Health & Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Brierley M Stuart
- Flow Cytometry Facility, Department of Molecular Medicine and Genetics, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Best G Oliver
- Flow Cytometry Facility, Department of Molecular Medicine and Genetics, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Michael Z Michael
- Visceral Pain Research Group, College of Medicine and Public Health, South Australian Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Voelcker H Nicolas
- Flinders Centre for Innovation in Cancer, College of Medicine and Public Health, Flinders University and Medical Centre, Bedford Park, Adelaide, South Australia, Australia
| | - Keating J Damien
- Human Physiology, Flinders Health & Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
| | - Haberberger V Rainer
- Anatomy and Histology, Flinders Health & Medical Research Institute, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
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19
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Jensen T, Walker AA, Nguyen SH, Jin AH, Deuis JR, Vetter I, King GF, Schmidt JO, Robinson SD. Venom chemistry underlying the painful stings of velvet ants (Hymenoptera: Mutillidae). Cell Mol Life Sci 2021; 78:5163-5177. [PMID: 33970306 PMCID: PMC11072429 DOI: 10.1007/s00018-021-03847-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/31/2021] [Accepted: 04/23/2021] [Indexed: 11/29/2022]
Abstract
Velvet ants (Hymenoptera: Mutillidae) are a family of solitary parasitoid wasps that are renowned for their painful stings. We explored the chemistry underlying the stings of mutillid wasps of the genus Dasymutilla Ashmead. Detailed analyses of the venom composition of five species revealed that they are composed primarily of peptides. We found that two kinds of mutillid venom peptide appear to be primarily responsible for the painful effects of envenomation. These same peptides also have defensive utility against invertebrates, since they were able to incapacitate and kill honeybees. Both act directly on cell membranes where they directly increase ion conductivity. The defensive venom peptides of Dasymutilla bear a striking similarity, in structure and mode of action, to those of the ant Myrmecia gulosa (Fabricius), suggesting either retention of ancestral toxins, or convergence driven by similar life histories and defensive selection pressures. Finally, we propose that other highly expressed Dasymutilla venom peptides may play a role in parasitisation, possible in delay or arrest of host development. This study represents the first detailed account of the composition and function of the venoms of the Mutillidae.
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Affiliation(s)
- Timo Jensen
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Andrew A Walker
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Son H Nguyen
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Ai-Hua Jin
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
- School of Pharmacy, The University of Queensland, Brisbane, QLD, 4102, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | | | - Samuel D Robinson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia.
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20
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Development of a novel in vitro assay to screen for neuroprotective drugs against iatrogenic neurite shortening. PLoS One 2021; 16:e0248139. [PMID: 33690613 PMCID: PMC7946280 DOI: 10.1371/journal.pone.0248139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 02/21/2021] [Indexed: 12/17/2022] Open
Abstract
This work tries to help overcome the lack of relevant translational screening assays, as a limitation for the identification of novel analgesics for neuropathic pain. Hyperexcitability and neurite shortening are common adverse effects of antiviral and antitumor drugs, leading to neuropathic pain. Now, as seen in the drug screening that we developed here, a high-content microscopy-based assay with immortalized dorsal root ganglia (DRG) neurons (differentiated F11 cells) allowed to identify drugs able to protect against the iatrogenic neurite shortening induced by the antitumor drug vincristine and the antiviral drug rilpivirine. We observed that vincristine and rilpivirine induced a significant reduction in the neurite length, which was reverted by α-lipoic acid. We had also evidenced protective effects of pregabalin and melatonin, acting through the α2δ-2 subunit of the voltage-dependent calcium channels and the MT1 receptor, respectively. Additionally, two hits originated from a previous primary screening aimed to detect inhibitors of hyperexcitability to inflammatory mediators in DRG neurons (nitrendipine and felodipine) also prevented neurite shortening in our model. In summary, in this work we developed a novel secondary assay for identifying hits with neuroprotective effect against iatrogenic neurite shortening, consistent with the anti-hyperexcitability action previously tested: highlighting nitrendipine and felodipine against iatrogenic damage in DRG neurons.
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21
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Kazandjian TD, Petras D, Robinson SD, van Thiel J, Greene HW, Arbuckle K, Barlow A, Carter DA, Wouters RM, Whiteley G, Wagstaff SC, Arias AS, Albulescu LO, Plettenberg Laing A, Hall C, Heap A, Penrhyn-Lowe S, McCabe CV, Ainsworth S, da Silva RR, Dorrestein PC, Richardson MK, Gutiérrez JM, Calvete JJ, Harrison RA, Vetter I, Undheim EAB, Wüster W, Casewell NR. Convergent evolution of pain-inducing defensive venom components in spitting cobras. Science 2021; 371:386-390. [PMID: 33479150 PMCID: PMC7610493 DOI: 10.1126/science.abb9303] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 12/07/2020] [Indexed: 01/06/2023]
Abstract
Convergent evolution provides insights into the selective drivers underlying evolutionary change. Snake venoms, with a direct genetic basis and clearly defined functional phenotype, provide a model system for exploring the repeated evolution of adaptations. While snakes use venom primarily for predation, and venom composition often reflects diet specificity, three lineages of cobras have independently evolved the ability to spit venom at adversaries. Using gene, protein, and functional analyses, we show that the three spitting lineages possess venoms characterized by an up-regulation of phospholipase A2 (PLA2) toxins, which potentiate the action of preexisting venom cytotoxins to activate mammalian sensory neurons and cause enhanced pain. These repeated independent changes provide a fascinating example of convergent evolution across multiple phenotypic levels driven by selection for defense.
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Affiliation(s)
- T D Kazandjian
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - D Petras
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA
| | - S D Robinson
- Centre for Advanced Imaging, University of Queensland, St Lucia, QLD 4072, Australia
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4072, Australia
| | - J van Thiel
- Institute of Biology, University of Leiden, Leiden 2333BE, Netherlands
| | - H W Greene
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - K Arbuckle
- Department of Biosciences, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - A Barlow
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK
- Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University, Bangor LL57 2UW, UK
| | - D A Carter
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4072, Australia
| | - R M Wouters
- Institute of Biology, University of Leiden, Leiden 2333BE, Netherlands
| | - G Whiteley
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - S C Wagstaff
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
- Research Computing Unit, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - A S Arias
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501, Costa Rica
| | - L-O Albulescu
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - A Plettenberg Laing
- Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University, Bangor LL57 2UW, UK
| | - C Hall
- Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University, Bangor LL57 2UW, UK
| | - A Heap
- Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University, Bangor LL57 2UW, UK
| | - S Penrhyn-Lowe
- Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University, Bangor LL57 2UW, UK
| | - C V McCabe
- School of Earth Sciences, University of Bristol, Bristol BS8 1RL, UK
| | - S Ainsworth
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - R R da Silva
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
- Núcleo de Pesquisa em Produtos Naturais e Sintéticos (NPPNS), Molecular Sciences Department, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - P C Dorrestein
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - M K Richardson
- Institute of Biology, University of Leiden, Leiden 2333BE, Netherlands
| | - J M Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501, Costa Rica
| | - J J Calvete
- Evolutionary and Translational Venomics Laboratory, Consejo Superior de Investigaciones Científicas, 46010 Valencia, Spain
| | - R A Harrison
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - I Vetter
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4072, Australia
- School of Pharmacy, University of Queensland, Woolloongabba, QLD 4102, Australia
| | - E A B Undheim
- Centre for Advanced Imaging, University of Queensland, St Lucia, QLD 4072, Australia
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4072, Australia
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Blindern, 0316 Oslo, Norway
| | - W Wüster
- Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University, Bangor LL57 2UW, UK
| | - N R Casewell
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK.
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McMahon KL, Tran HN, Deuis JR, Lewis RJ, Vetter I, Schroeder CI. Discovery, Pharmacological Characterisation and NMR Structure of the Novel µ-Conotoxin SxIIIC, a Potent and Irreversible Na V Channel Inhibitor. Biomedicines 2020; 8:biomedicines8100391. [PMID: 33023152 PMCID: PMC7599555 DOI: 10.3390/biomedicines8100391] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium (NaV) channel subtypes, including NaV1.7, are promising targets for the treatment of neurological diseases, such as chronic pain. Cone snail-derived µ-conotoxins are small, potent NaV channel inhibitors which represent potential drug leads. Of the 22 µ-conotoxins characterised so far, only a small number, including KIIIA and CnIIIC, have shown inhibition against human NaV1.7. We have recently identified a novel µ-conotoxin, SxIIIC, from Conus striolatus. Here we present the isolation of native peptide, chemical synthesis, characterisation of human NaV channel activity by whole-cell patch-clamp electrophysiology and analysis of the NMR solution structure. SxIIIC displays a unique NaV channel selectivity profile (1.4 > 1.3 > 1.1 ≈ 1.6 ≈ 1.7 > 1.2 >> 1.5 ≈ 1.8) when compared to other µ-conotoxins and represents one of the most potent human NaV1.7 putative pore blockers (IC50 152.2 ± 21.8 nM) to date. NMR analysis reveals the structure of SxIIIC includes the characteristic α-helix seen in other µ-conotoxins. Future investigations into structure-activity relationships of SxIIIC are expected to provide insights into residues important for NaV channel pore blocker selectivity and subsequently important for chronic pain drug development.
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Affiliation(s)
- Kirsten L. McMahon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
| | - Hue N.T. Tran
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
| | - Jennifer R. Deuis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
| | - Richard J. Lewis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
- The School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia
- Correspondence: (I.V.); (C.I.S.)
| | - Christina I. Schroeder
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; (K.L.M.); (H.N.T.T.); (J.R.D.); (R.J.L.)
- National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
- Correspondence: (I.V.); (C.I.S.)
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Collaço RDC, Hyslop S, Rocha T, Dorce VAC, Rowan EG, Antunes E. Neurotoxicity of Tityus bahiensis (brown scorpion) venom in sympathetic vas deferens preparations and neuronal cells. Arch Toxicol 2020; 94:3315-3327. [PMID: 32548756 PMCID: PMC7415753 DOI: 10.1007/s00204-020-02799-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 05/28/2020] [Indexed: 01/04/2023]
Abstract
Systemic scorpion envenomation is characterized by massive neurotransmitter release from peripheral nerves mediated primarily by scorpion venoms neurotoxins. Tityus bahiensis is one of the medically most important species in Brazil, but its venom pharmacology, especially regarding to peripheral nervous system, is poorly understood. Here, we evaluated the T. bahiensis venom activity on autonomic (sympathetic) neurotransmission by using a variety of approaches, including vas deferens twitch-tension recordings, electrophysiological measurements (resting membrane potentials, spontaneous excitatory junctional potentials and whole-cell patch-clamp), calcium imaging and histomorphological analysis. Low concentrations of venom (≤ 3 μg/mL) facilitated the electrically stimulated vas deferens contractions without affecting postsynaptic receptors or damaging the smooth muscle cells. Transient TTX-sensitive sustained contractions and resting membrane depolarization were mediated mainly by massive spontaneous ATP release. High venom concentrations (≥ 10 μg/mL) blocked the muscle contractions and induced membrane depolarization. In neuronal cells (ND7-23wt), the venom increased the peak sodium current, modified the current-voltage relationship by left-shifting the Nav-channel activation curve, thereby facilitating the opening of these channels. The venom also caused a time-dependent increase in neuronal calcium influx. These results indicate that the sympathetic hyperstimulation observed in systemic envenomation is presynaptically driven, probably through the interaction of α- and β-toxins with neuronal sodium channels.
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Affiliation(s)
- Rita de Cássia Collaço
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK.
| | - Stephen Hyslop
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Thalita Rocha
- São Francisco University (USF), Bragança Paulista, SP, Brazil
| | - Valquiria A C Dorce
- Laboratory of Pharmacology, Division for Scientific Development, Butantan Institute, São Paulo, SP, Brazil
| | - Edward G Rowan
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Edson Antunes
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
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Cardoso FC, Marliac MA, Geoffroy C, Schmit M, Bispat A, Lewis RJ, Tuck KL, Duggan PJ. The neuronal calcium ion channel activity of constrained analogues of MONIRO-1. Bioorg Med Chem 2020; 28:115655. [DOI: 10.1016/j.bmc.2020.115655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/06/2020] [Accepted: 07/10/2020] [Indexed: 01/19/2023]
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Nixon SA, Dekan Z, Robinson SD, Guo S, Vetter I, Kotze AC, Alewood PF, King GF, Herzig V. It Takes Two: Dimerization Is Essential for the Broad-Spectrum Predatory and Defensive Activities of the Venom Peptide Mp1a from the Jack Jumper Ant Myrmecia pilosula. Biomedicines 2020; 8:biomedicines8070185. [PMID: 32629771 PMCID: PMC7400207 DOI: 10.3390/biomedicines8070185] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 02/07/2023] Open
Abstract
Ant venoms have recently attracted increased attention due to their chemical complexity, novel molecular frameworks, and diverse biological activities. The heterodimeric peptide ∆-myrtoxin-Mp1a (Mp1a) from the venom of the Australian jack jumper ant, Myrmecia pilosula, exhibits antimicrobial, membrane-disrupting, and pain-inducing activities. In the present study, we examined the activity of Mp1a and a panel of synthetic analogues against the gastrointestinal parasitic nematode Haemonchus contortus, the fruit fly Drosophila melanogaster, and for their ability to stimulate pain-sensing neurons. Mp1a was found to be both insecticidal and anthelmintic, and it robustly activated mammalian sensory neurons at concentrations similar to those reported to elicit antimicrobial and cytotoxic activity. The native antiparallel Mp1a heterodimer was more potent than heterodimers with alternative disulfide connectivity, as well as monomeric analogues. We conclude that the membrane-disrupting effects of Mp1a confer broad-spectrum biological activities that facilitate both predation and defense for the ant. Our structure-activity data also provide a foundation for the rational engineering of analogues with selectivity for particular cell types.
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Affiliation(s)
- Samantha A. Nixon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (S.A.N.); (Z.D.); (S.D.R.); (S.G.); (I.V.); (P.F.A.)
- CSIRO Agriculture and Food, St Lucia, QLD 4072, Australia;
| | - Zoltan Dekan
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (S.A.N.); (Z.D.); (S.D.R.); (S.G.); (I.V.); (P.F.A.)
| | - Samuel D. Robinson
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (S.A.N.); (Z.D.); (S.D.R.); (S.G.); (I.V.); (P.F.A.)
| | - Shaodong Guo
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (S.A.N.); (Z.D.); (S.D.R.); (S.G.); (I.V.); (P.F.A.)
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (S.A.N.); (Z.D.); (S.D.R.); (S.G.); (I.V.); (P.F.A.)
- School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia
| | | | - Paul F. Alewood
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (S.A.N.); (Z.D.); (S.D.R.); (S.G.); (I.V.); (P.F.A.)
| | - Glenn F. King
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (S.A.N.); (Z.D.); (S.D.R.); (S.G.); (I.V.); (P.F.A.)
- Correspondence: (G.F.K.); (V.H.); Tel.: +61-7-3346-2025 (G.F.K.); +61-7-5456-5382 (V.H.)
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (S.A.N.); (Z.D.); (S.D.R.); (S.G.); (I.V.); (P.F.A.)
- School of Science & Engineering, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia
- Correspondence: (G.F.K.); (V.H.); Tel.: +61-7-3346-2025 (G.F.K.); +61-7-5456-5382 (V.H.)
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Haberberger RV, Barry C, Matusica D. Immortalized Dorsal Root Ganglion Neuron Cell Lines. Front Cell Neurosci 2020; 14:184. [PMID: 32636736 PMCID: PMC7319018 DOI: 10.3389/fncel.2020.00184] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 05/28/2020] [Indexed: 12/14/2022] Open
Abstract
Pain is one of the most significant causes of suffering and disability world-wide, and arguably the most burdensome global health challenge. The growing number of patients suffering from chronic pain conditions such as fibromyalgia, complex regional pain syndrome, migraine and irritable bowel syndrome, not only reflect the complexity and heterogeneity of pain types, but also our lack of understanding of the underlying mechanisms. Sensory neurons within the dorsal root ganglia (DRG) have emerged as viable targets for effective chronic pain therapy. However, DRG's contain different classes of primary sensory neurons including pain-associated nociceptive neurons, non-nociceptive temperature sensing, mechanosensory and chemoreceptive neurons, as well as multiple types of immune and endothelial cells. This cell-population heterogeneity makes investigations of individual subgroups of DRG neurons, such as nociceptors, difficult. In attempts to overcome some of these difficulties, a limited number of immortalized DRG-derived cell lines have been generated over the past few decades. In vitro experiments using DRG-derived cell lines have been useful in understanding sensory neuron function. In addition to retaining phenotypic similarities to primary cultured DRG neurons, these cells offer greater suitability for high throughput assays due to ease of culture, maintenance, growth efficiency and cost-effectiveness. For accurate interpretation and translation of results it is critical, however, that phenotypic similarities and differences of DRG-derived cells lines are methodically compared to native neurons. Published reports to date show notable variability in how these DRG-derived cells are maintained and differentiated. Understanding the cellular and molecular differences stemming from different culture methods, is essential to validate past and future experiments, and enable these cells to be used to their full potential. This review describes currently available DRG-derived cell lines, their known sensory and nociceptor specific molecular profiles, and summarize their morphological features related to differentiation and neurite outgrowth.
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Affiliation(s)
- Rainer Viktor Haberberger
- Anatomy & Histology, College of Medicine and Public Health, Flinders Health & Medical Research Institute, Flinders University, Adelaide, SA, Australia
| | - Christine Barry
- Anatomy & Histology, College of Medicine and Public Health, Flinders Health & Medical Research Institute, Flinders University, Adelaide, SA, Australia
| | - Dusan Matusica
- Anatomy & Histology, College of Medicine and Public Health, Flinders Health & Medical Research Institute, Flinders University, Adelaide, SA, Australia
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27
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Wilson DT, Bansal PS, Carter DA, Vetter I, Nicke A, Dutertre S, Daly NL. Characterisation of a Novel A-Superfamily Conotoxin. Biomedicines 2020; 8:biomedicines8050128. [PMID: 32443665 PMCID: PMC7277881 DOI: 10.3390/biomedicines8050128] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 05/15/2020] [Accepted: 05/18/2020] [Indexed: 12/13/2022] Open
Abstract
Conopeptides belonging to the A-superfamily from the venomous molluscs, Conus, are typically α-conotoxins. The α-conotoxins are of interest as therapeutic leads and pharmacological tools due to their selectivity and potency at nicotinic acetylcholine receptor (nAChR) subtypes. Structurally, the α-conotoxins have a consensus fold containing two conserved disulfide bonds that define the two-loop framework and brace a helical region. Here we report on a novel α-conotoxin Pl168, identified from the transcriptome of Conus planorbis, which has an unusual 4/8 loop framework. Unexpectedly, NMR determination of its three-dimensional structure reveals a new structural type of A-superfamily conotoxins with a different disulfide-stabilized fold, despite containing the conserved cysteine framework and disulfide connectivity of classical α-conotoxins. The peptide did not demonstrate activity on a range of nAChRs, or Ca2+ and Na+ channels suggesting that it might represent a new pharmacological class of conotoxins.
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Affiliation(s)
- David T. Wilson
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD 4878, Australia; (D.T.W.); (P.S.B.)
| | - Paramjit S. Bansal
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD 4878, Australia; (D.T.W.); (P.S.B.)
| | - David A. Carter
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (D.A.C.); (I.V.)
| | - Irina Vetter
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; (D.A.C.); (I.V.)
- School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Nußbaumstraße 26, 80336 Munich, Germany;
| | - Sébastien Dutertre
- Institut des Biomolécules Max Mousseron, UMR 5247, Université de Montpellier, CNRS, 34095 Montpellier, France;
| | - Norelle L. Daly
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD 4878, Australia; (D.T.W.); (P.S.B.)
- Correspondence: ; Tel.: +61-7-4232-1815
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28
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Ma J, Stefanoska D, Grad S, Alini M, Peroglio M. Direct and Intervertebral Disc-Mediated Sensitization of Dorsal Root Ganglion Neurons by Hypoxia and Low pH. Neurospine 2020; 17:42-59. [PMID: 32252154 PMCID: PMC7136118 DOI: 10.14245/ns.2040052.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 02/28/2020] [Indexed: 12/21/2022] Open
Abstract
Objective Ischemia-related risk factors are consistently correlated with discogenic pain, but it remains unclear how the ischemia-associated hypoxia and acidosis influence the peripheral sensory nervous system, namely the dorsal root ganglion (DRG), either directly or indirectly via intervertebral disc (IVD) mediation.
Methods Bovine tail IVD organ cultures were preconditioned in different hypoxic and/or acidic conditions for 3 days to collect the conditioned medium (CM). The DRG-derived ND7/23 cells were either treated by the IVD CM or directly stimulated by hypoxic and/or acidic conditions. Neuronal sensitization was evaluated using calcium imaging (Fluo-4) after 3 days.
Results We found that direct exposure of DRG cell line to hypoxia and acidosis increased both spontaneous and bradykinin-stimulated calcium response compared to normoxia-neutral pH cultures. Hypoxia and low pH in combination showed stronger effect than either parameter on its own. Indirect exposure of DRG to hypoxia-acidosis-stressed IVD CM also increased spontaneous and bradykinin-stimulated response, but to a lower extent than direct exposure. The impact of direct hypoxia and acidosis on DRG was validated in a primary sheep DRG cell culture, showing the same trend.
Conclusion Our data suggest that targeting hypoxia and acidosis stresses both in IVD and DRG could be a relevant objective in discogenic pain treatment.
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Affiliation(s)
- Junxuan Ma
- AO Research Institute Davos, Davos, Switzerland
| | | | | | - Mauro Alini
- AO Research Institute Davos, Davos, Switzerland
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29
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Kang P, Li X, Liu Y, Shiers SI, Xiong H, Giannotta M, Dejana E, Price TJ, Randrianalisoa J, Nielsen SO, Qin Z. Transient Photoinactivation of Cell Membrane Protein Activity without Genetic Modification by Molecular Hyperthermia. ACS NANO 2019; 13:12487-12499. [PMID: 31613606 PMCID: PMC7096286 DOI: 10.1021/acsnano.9b01993] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Precise manipulation of protein activity in living systems has broad applications in biomedical sciences. However, it is challenging to use light to manipulate protein activity in living systems without genetic modification. Here, we report a technique to optically switch off protein activity in living cells with high spatiotemporal resolution, referred to as molecular hyperthermia (MH). MH is based on the nanoscale-confined heating of plasmonic gold nanoparticles by short laser pulses to unfold and photoinactivate targeted proteins of interest. First, we show that protease-activated receptor 2 (PAR2), a G-protein-coupled receptor and an important pathway that leads to pain sensitization, can be photoinactivated in situ by MH without compromising cell proliferation. PAR2 activity can be switched off in laser-targeted cells without affecting surrounding cells. Furthermore, we demonstrate the molecular specificity of MH by inactivating PAR2 while leaving other receptors intact. Second, we demonstrate that the photoinactivation of a tight junction protein in brain endothelial monolayers leads to a reversible blood-brain barrier opening in vitro. Lastly, the protein inactivation by MH is below the nanobubble generation threshold and thus is predominantly due to the nanoscale heating. MH is distinct from traditional hyperthermia (that induces global tissue heating) in both its time and length scales: nanoseconds versus seconds, nanometers versus millimeters. Our results demonstrate that MH enables selective and remote manipulation of protein activity and cellular behavior without genetic modification.
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Affiliation(s)
- Peiyuan Kang
- Department of Mechanical Engineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080, USA
| | - Xiaoqing Li
- Department of Bioengineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080, USA
| | - Yaning Liu
- Department of Mechanical Engineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080, USA
| | - Stephanie I. Shiers
- School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080, USA
| | - Hejian Xiong
- Department of Mechanical Engineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080, USA
| | - Monica Giannotta
- Vascular Biology Laboratory, The FIRC Institute of Molecular Oncology (IFOM), 20139 Milan, Italy
| | - Elisabetta Dejana
- Vascular Biology Laboratory, The FIRC Institute of Molecular Oncology (IFOM), 20139 Milan, Italy
- Department of Immunology, Genetics and Pathology, University of Uppsala, 751 05 Uppsala, Sweden
| | - Theodore John Price
- School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080, USA
| | - Jaona Randrianalisoa
- Institut de Thermique, Mécanique, Matériaux (ITheMM EA 7548), University of Reims Champagne-Ardenne, Reims Cedex 2, 51687 France
| | - Steven O. Nielsen
- Department of Chemistry and Biochemistry, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080, USA
| | - Zhenpeng Qin
- Department of Mechanical Engineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080, USA
- Department of Bioengineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080, USA
- Department of Surgery, University of Texas at Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390, USA
- Corresponding Author: . Phone: (972)883-4440
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Ambrosino P, Soldovieri MV, Di Zazzo E, Paventi G, Iannotti FA, Mosca I, Miceli F, Franco C, Canzoniero LMT, Taglialatela M. Activation of Kv7 Potassium Channels Inhibits Intracellular Ca 2+ Increases Triggered By TRPV1-Mediated Pain-Inducing Stimuli in F11 Immortalized Sensory Neurons. Int J Mol Sci 2019; 20:ijms20184322. [PMID: 31487785 PMCID: PMC6769798 DOI: 10.3390/ijms20184322] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/01/2019] [Accepted: 09/02/2019] [Indexed: 12/11/2022] Open
Abstract
Kv7.2-Kv7.5 channels mediate the M-current (IKM), a K+-selective current regulating neuronal excitability and representing an attractive target for pharmacological therapy against hyperexcitability diseases such as pain. Kv7 channels interact functionally with transient receptor potential vanilloid 1 (TRPV1) channels activated by endogenous and/or exogenous pain-inducing substances, such as bradykinin (BK) or capsaicin (CAP), respectively; however, whether Kv7 channels of specific molecular composition provide a dominant contribution in BK- or CAP-evoked responses is yet unknown. To this aim, Kv7 transcripts expression and function were assessed in F11 immortalized sensorial neurons, a cellular model widely used to assess nociceptive molecular mechanisms. In these cells, the effects of the pan-Kv7 activator retigabine were investigated, as well as the effects of ICA-27243 and (S)-1, two Kv7 activators acting preferentially on Kv7.2/Kv7.3 and Kv7.4/Kv7.5 channels, respectively, on BK- and CAP-induced changes in intracellular Ca2+ concentrations ([Ca2+]i). The results obtained revealed the expression of transcripts of all Kv7 genes, leading to an IKM-like current. Moreover, all tested Kv7 openers inhibited BK- and CAP-induced responses by a similar extent (~60%); at least for BK-induced Ca2+ responses, the potency of retigabine (IC50~1 µM) was higher than that of ICA-27243 (IC50~5 µM) and (S)-1 (IC50~7 µM). Altogether, these results suggest that IKM activation effectively counteracts the cellular processes triggered by TRPV1-mediated pain-inducing stimuli, and highlight a possible critical contribution of Kv7.4 subunits.
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Affiliation(s)
- Paolo Ambrosino
- Department of Science and Technology, University of Sannio, 82100 Benevento, Italy
| | - Maria Virginia Soldovieri
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, 86100 Campobasso, Italy
| | - Erika Di Zazzo
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, 86100 Campobasso, Italy
| | - Gianluca Paventi
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, 86100 Campobasso, Italy
| | - Fabio Arturo Iannotti
- Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, 80121 Naples, Italy
| | - Ilaria Mosca
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, 86100 Campobasso, Italy
| | - Francesco Miceli
- Division of Pharmacology, Department of Neuroscience, University of Naples "Federico II", 80131 Naples, Italy
| | - Cristina Franco
- Department of Science and Technology, University of Sannio, 82100 Benevento, Italy
| | | | - Maurizio Taglialatela
- Division of Pharmacology, Department of Neuroscience, University of Naples "Federico II", 80131 Naples, Italy.
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Scorpion venom increases acetylcholine release by prolonging the duration of somatic nerve action potentials. Neuropharmacology 2019; 153:41-52. [PMID: 30995441 DOI: 10.1016/j.neuropharm.2019.04.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/20/2019] [Accepted: 04/10/2019] [Indexed: 12/14/2022]
Abstract
Scorpionism is frequently accompanied by a massive release of catecholamines and acetylcholine from peripheral nerves caused by neurotoxic peptides present in these venoms, which have high specificity and affinity for ion channels. Tityus bahiensis is the second most medically important scorpion species in Brazil but, despite this, its venom remains scarcely studied, especially with regard to its pharmacology on the peripheral (somatic and autonomic) nervous system. Here, we evaluated the activity of T. bahiensis venom on somatic neurotransmission using myographic (chick and mouse neuromuscular preparations), electrophysiological (MEPP, EPP, resting membrane potentials, perineural waveforms, compound action potentials) and calcium imaging (on DRG neurons and muscle fibres) techniques. Our results show that the major toxic effects of T. bahiensis venom on neuromuscular function are presynaptically driven by the increase in evoked and spontaneous neurotransmitter release. Low venom concentrations prolong the axonal action potential, leading to a longer depolarization of the nerve terminals that enhances neurotransmitter release and facilitates nerve-evoked muscle contraction. The venom also stimulates the spontaneous release of neurotransmitters, probably through partial neuronal depolarization that allows calcium influx. Higher venom concentrations block the generation of action potentials and resulting muscle twitches. These effects of the venom were reversed by low concentrations of TTX, indicating voltage-gated sodium channels as the primary target of the venom toxins. These results suggest that the major neuromuscular toxicity of T. bahiensis venom is probably mediated mainly by α- and β-toxins interacting with presynaptic TTX-sensitive ion channels on both axons and nerve terminals.
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Macikova L, Sinica V, Kadkova A, Villette S, Ciaccafava A, Faherty J, Lecomte S, Alves ID, Vlachova V. Putative interaction site for membrane phospholipids controls activation of TRPA1 channel at physiological membrane potentials. FEBS J 2019; 286:3664-3683. [PMID: 31116904 DOI: 10.1111/febs.14931] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/09/2019] [Accepted: 05/20/2019] [Indexed: 12/16/2022]
Abstract
The transient receptor potential ankyrin 1 (TRPA1) channel is a polymodal sensor of environmental irritant compounds, endogenous proalgesic agents, and cold. Upon activation, TRPA1 channels increase cellular calcium levels via direct permeation and trigger signaling pathways that hydrolyze phosphatidylinositol-4,5-bisphosphate (PIP2 ) in the inner membrane leaflet. Our objective was to determine the extent to which a putative PIP2 -interaction site (Y1006-Q1031) is involved in TRPA1 regulation. The interactions of two specific peptides (L992-N1008 and T1003-P1034) with model lipid membranes were characterized by biophysical approaches to obtain information about affinity, peptide secondary structure, and peptide effect in the lipid organization. The results indicate that the two peptides interact with lipid membranes only if PIP2 is present and their affinities depend on the presence of calcium. Using whole-cell electrophysiology, we demonstrate that mutation at F1020 produced channels with faster activation kinetics and with a rightward shifted voltage-dependent activation curve by altering the allosteric constant that couples voltage sensing to pore opening. We assert that the presence of PIP2 is essential for the interaction of the two peptide sequences with the lipid membrane. The putative phosphoinositide-interacting domain comprising the highly conserved F1020 contributes to the stabilization of the TRPA1 channel gate.
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Affiliation(s)
- Lucie Macikova
- CBMN-UMR 5248 CNRS, IPB, University of Bordeaux, Pessac, France.,Department of Cellular Neurophysiology, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.,Department of Physiology, Faculty of Science, Charles University in Prague, Czech Republic
| | - Viktor Sinica
- Department of Cellular Neurophysiology, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Anna Kadkova
- Department of Cellular Neurophysiology, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | | | | | | | - Sophie Lecomte
- CBMN-UMR 5248 CNRS, IPB, University of Bordeaux, Pessac, France
| | - Isabel D Alves
- CBMN-UMR 5248 CNRS, IPB, University of Bordeaux, Pessac, France
| | - Viktorie Vlachova
- Department of Cellular Neurophysiology, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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33
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Ponce A, Castillo A, Hinojosa L, Martinez-Rendon J, Cereijido M. The expression of endogenous voltage-gated potassium channels in HEK293 cells is affected by culture conditions. Physiol Rep 2019; 6:e13663. [PMID: 29665277 PMCID: PMC5903699 DOI: 10.14814/phy2.13663] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 02/23/2018] [Accepted: 03/05/2018] [Indexed: 01/06/2023] Open
Abstract
HEK293 cells are widely used as a host for expression of heterologous proteins; yet, little care has been taken to characterize their endogenous membrane components, including ion channels. In this work, we aimed to describe the biophysical and pharmacological properties of endogenous, voltage‐dependent potassium currents (IKv). We also examined how its expression depends on culture conditions. We used the electrophysiological technique of whole‐cell patch clamp to record ion currents from HEK293 cells. We found that HEK cells express endogenous, voltage‐dependent potassium currents. We also found that diverse culture conditions, such as the passage number, the cell density, the type of serum that complements the culture media and the substratum, affect the magnitude and shape of IKv, resulting from the relative contribution of fast, slow, and noninactivating component currents. Incubation of cells in mature monolayers with trypsin–EDTA, notoriously reduces the magnitude and modifies the shape of voltage‐dependent potassium endogenous currents; nonetheless HEK cells recover IKv′s magnitude and shape within 6 h after replating, with a process that requires synthesis of new mRNA and protein subunits, as evidenced by the fact that actinomycin D and cycloheximide, inhibitors of synthesis of mRNA and protein, respectively, impair the recovery of IKv after trypsinization. In addition to be useful as a model expression system, HEK293 may be useful to understand how cells regulate the density of ion channels on the membrane.
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Affiliation(s)
- Arturo Ponce
- Department of Physiology, Biophysics and Neurosciences, Center For Research and Advanced Studies (Cinvestav), México D. F., México
| | - Aida Castillo
- Department of Physiology, Biophysics and Neurosciences, Center For Research and Advanced Studies (Cinvestav), México D. F., México
| | - Lorena Hinojosa
- Department of Physiology, Biophysics and Neurosciences, Center For Research and Advanced Studies (Cinvestav), México D. F., México
| | - Jacqueline Martinez-Rendon
- Department of Physiology, Biophysics and Neurosciences, Center For Research and Advanced Studies (Cinvestav), México D. F., México
| | - Marcelino Cereijido
- Department of Physiology, Biophysics and Neurosciences, Center For Research and Advanced Studies (Cinvestav), México D. F., México
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Novel conorfamides from Conus austini venom modulate both nicotinic acetylcholine receptors and acid-sensing ion channels. Biochem Pharmacol 2019; 164:342-348. [PMID: 31028742 DOI: 10.1016/j.bcp.2019.04.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 04/22/2019] [Indexed: 01/06/2023]
Abstract
Conorfamides are a poorly studied family of cone snail venom peptides with broad biological activities, including inhibition of glutamate receptors, acid-sensing ion channels, and voltage-gated potassium channels. The aim of this study was to characterize the pharmacological activity of two novel linear conorfamides (conorfamide_As1a and conorfamide_As2a) and their non-amidated counterparts (conopeptide_As1b and conopeptide_As2b) that were isolated from the venom of the Mexican cone snail Conus austini. Although As1a, As2a, As1b and As2b were identified by activity-guided fractionation using a high-throughput fluorescence imaging plate reader (FLIPR) assay assessing α7 nAChR activity, sequence determination revealed activity associated with four linear peptides of the conorfamide rather than the anticipated α-conotoxin family. Pharmacological testing revealed that the amidated peptide variants altered desensitization of acid-sensing ion channels (ASICs) 1a and 3, and the native lysine to arginine mutation differentiating As1a and As1b from As2a and As2b introduced ASIC1a peak current potentiation. Surprisingly, these conorfamides also inhibited α7 and muscle-type nicotinic acetylcholine receptors (nAChR) at nanomolar concentrations. This is the first report of conorfamides with dual activity, with the nAChR activity being the most potent molecular target of any conorfamide discovered to date.
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35
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Dittert I, Prucha J, Krusek J, Sinica V, Kadkova A, Vlachova V. Acute exposure to high‐induction electromagnetic field affects activity of model peripheral sensory neurons. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.706.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ivan Dittert
- Institute of Physiology ASCRPrague 4Czech Republic
| | - Jaroslav Prucha
- Faculty of Biomedical EngineeringCzech Technical University in PragueKladnoCzech Republic
| | - Jan Krusek
- Institute of Physiology ASCRPrague 4Czech Republic
| | | | - Anna Kadkova
- Institute of Physiology ASCRPrague 4Czech Republic
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36
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Otvos RA, Still KBM, Somsen GW, Smit AB, Kool J. Drug Discovery on Natural Products: From Ion Channels to nAChRs, from Nature to Libraries, from Analytics to Assays. SLAS DISCOVERY : ADVANCING LIFE SCIENCES R & D 2019; 24:362-385. [PMID: 30682257 PMCID: PMC6484542 DOI: 10.1177/2472555218822098] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 11/16/2018] [Accepted: 12/07/2018] [Indexed: 12/21/2022]
Abstract
Natural extracts are complex mixtures that may be rich in useful bioactive compounds and therefore are attractive sources for new leads in drug discovery. This review describes drug discovery from natural products and in explaining this process puts the focus on ion-channel drug discovery. In particular, the identification of bioactives from natural products targeting nicotinic acetylcholine receptors (nAChRs) and serotonin type 3 receptors (5-HT3Rs) is discussed. The review is divided into three parts: "Targets," "Sources," and "Approaches." The "Targets" part will discuss the importance of ion-channel drug targets in general, and the α7-nAChR and 5-HT3Rs in particular. The "Sources" part will discuss the relevance for drug discovery of finding bioactive compounds from various natural sources such as venoms and plant extracts. The "Approaches" part will give an overview of classical and new analytical approaches that are used for the identification of new bioactive compounds with the focus on targeting ion channels. In addition, a selected overview is given of traditional venom-based drug discovery approaches and of diverse hyphenated analytical systems used for screening complex bioactive mixtures including venoms.
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Affiliation(s)
- Reka A. Otvos
- The Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of BioAnalytical Chemistry, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Kristina B. M. Still
- The Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of BioAnalytical Chemistry, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Govert W. Somsen
- The Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of BioAnalytical Chemistry, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - August B. Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Jeroen Kool
- The Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Division of BioAnalytical Chemistry, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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37
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Zhang W, Takahara T, Achiha T, Shibata H, Maki M. Cellular Ca 2+-Responding Nanoluciferase Reporter Gene System Directed by Tandemly Repeated Pseudo-palindromic NFAT-Response Elements. Methods Mol Biol 2019; 1929:95-109. [PMID: 30710269 DOI: 10.1007/978-1-4939-9030-6_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Luciferase reporter gene systems based on the NFAT-response element (RE) have been used to monitor intracellular Ca2+ elevation. However, Ca2+ mobilization agent (e.g., ionomycin) alone is not adequate to activate the currently often employed reporter gene that contains the NFAT-RE found in the IL2 promoter. In addition to activation of NFAT through the Ca2+-calmodulin/calcineurin pathway, activation of AP-1 as a partner transcription factor is essential for the IL2-based NFAT-RE system. Here, we describe a detailed method for the recently developed new reporter gene system containing the NFAT-RE from the IL8 promoter. This system enables us to monitor endpoint effects of Ca2+-mobilizing agonists independent of AP-1 activation.
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Affiliation(s)
- Wei Zhang
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Terunao Takahara
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
| | - Takuya Achiha
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Hideki Shibata
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Masatoshi Maki
- Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
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38
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Martínez AL, Brea J, Monroy X, Merlos M, Burgueño J, Loza MI. A New Model of Sensorial Neuron-Like Cells for HTS of Novel Analgesics for Neuropathic Pain. SLAS DISCOVERY 2018; 24:158-168. [PMID: 30383474 DOI: 10.1177/2472555218810323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this study we developed a new translational phenotypic in vitro model for high-throughput screening (HTS) of novel analgesics for treating neuropathic pain, in order to address the poor translation of traditional recombinant models. The immortalized dorsal root ganglia (DRG) neuron-like F11 cell line was selected based on its phenotype after differentiation. The acquisition of neuronal characteristics was evaluated by measuring the expression of TrkA as a DRG neuron marker ( p < 0.01) as well as by measuring the global neurite length ( p < 0.001). The response of F11 cells to ATP and KCl was obtained by measuring intracellular calcium concentration, dynamic mass redistribution, and membrane potential. A KCl-induced increase of intracellular calcium levels was chosen as the readout because of the better signal quality, higher reproducibility, and greater compatibility with HTS assay requirements compared with other methods. The response to KCl differed significantly between differentiated and undifferentiated cells ( p < 0.05), with an EC50 value of 5 mM in differentiated cells. The model was validated by screening the Prestwick Chemical Library. Five hits already proposed for neuropathic-related pain were identified, with IC50 values between 1 and 7 µM. This cell model provides a new tool for screening novel analgesics for the relief of neuropathic pain.
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Affiliation(s)
- Antón L Martínez
- 1 BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - José Brea
- 1 BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Xavier Monroy
- 2 Esteve Pharmaceuticals, Parc Cientific de Barcelona, Barcelona, Spain
| | - Manuel Merlos
- 2 Esteve Pharmaceuticals, Parc Cientific de Barcelona, Barcelona, Spain
| | - Javier Burgueño
- 2 Esteve Pharmaceuticals, Parc Cientific de Barcelona, Barcelona, Spain
| | - María Isabel Loza
- 1 BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
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Sairaman A, Cardoso FC, Bispat A, Lewis RJ, Duggan PJ, Tuck KL. Synthesis and evaluation of aminobenzothiazoles as blockers of N- and T-type calcium channels. Bioorg Med Chem 2018; 26:3046-3059. [DOI: 10.1016/j.bmc.2018.03.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/15/2018] [Accepted: 03/18/2018] [Indexed: 10/17/2022]
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40
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Kádková A, Synytsya V, Krusek J, Zímová L, Vlachová V. Molecular basis of TRPA1 regulation in nociceptive neurons. A review. Physiol Res 2018; 66:425-439. [PMID: 28730837 DOI: 10.33549/physiolres.933553] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Transient receptor potential A1 (TRPA1) is an excitatory ion channel that functions as a cellular sensor, detecting a wide range of proalgesic agents such as environmental irritants and endogenous products of inflammation and oxidative stress. Topical application of TRPA1 agonists produces an acute nociceptive response through peripheral release of neuropeptides, purines and other transmitters from activated sensory nerve endings. This, in turn, further regulates TRPA1 activity downstream of G-protein and phospholipase C-coupled signaling cascades. Despite the important physiological relevance of such regulation leading to nociceptor sensitization and consequent pain hypersensitivity, the specific domains through which TRPA1 undergoes post-translational modifications that affect its activation properties are yet to be determined at a molecular level. This review aims at providing an account of our current knowledge on molecular basis of regulation by neuronal inflammatory signaling pathways that converge on the TRPA1 channel protein and through modification of its specific residues influence the extent to which this channel may contribute to pain.
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Affiliation(s)
- A Kádková
- Department of Cellular Neurophysiology, Institute of Physiology CAS, Prague, Czech Republic. or
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41
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Nanoluciferase Reporter Gene System Directed by Tandemly Repeated Pseudo-Palindromic NFAT-Response Elements Facilitates Analysis of Biological Endpoint Effects of Cellular Ca 2+ Mobilization. Int J Mol Sci 2018; 19:ijms19020605. [PMID: 29463029 PMCID: PMC5855827 DOI: 10.3390/ijms19020605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/11/2018] [Accepted: 02/14/2018] [Indexed: 01/12/2023] Open
Abstract
NFAT is a cytoplasm-localized hyper-phosphorylated transcription factor that is activated through dephosphorylation by calcineurin, a Ca2+/calmodulin-dependent phosphatase. A non-palindromic NFAT-response element (RE) found in the IL2 promoter region has been commonly used for a Ca2+-response reporter gene system, but requirement of concomitant activation of AP-1 (Fos/Jun) often complicates the interpretation of obtained results. A new nanoluciferase (NanoLuc) reporter gene containing nine-tandem repeats of a pseudo-palindromic NFAT-RE located upstream of the IL8 promoter was designed to monitor Ca2+-induced transactivation activity of NFAT in human embryonic kidney (HEK) 293 cells by measuring luciferase activities of NanoLuc and co-expressed firefly luciferase for normalization. Ionomycin treatment enhanced the relative luciferase activity (RLA), which was suppressed by calcineurin inhibitors. HEK293 cells that stably express human STIM1 and Orai1, components of the store-operated calcium entry (SOCE) machinery, gave a much higher RLA by stimulation with thapsigargin, an inhibitor of sarcoplasmic/endoplamic reticulum Ca2+-ATPase (SERCA). HEK293 cells deficient in a penta-EF-hand Ca2+-binding protein ALG-2 showed a higher RLA value than the parental cells by stimulation with an acetylcholine receptor agonist carbachol. The novel reporter gene system is found to be useful for applications to cell signaling research to monitor biological endpoint effects of cellular Ca2+ mobilization.
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42
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Prucha J, Krusek J, Dittert I, Sinica V, Kadkova A, Vlachova V. Acute exposure to high-induction electromagnetic field affects activity of model peripheral sensory neurons. J Cell Mol Med 2017; 22:1355-1362. [PMID: 29210178 PMCID: PMC5783861 DOI: 10.1111/jcmm.13423] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/15/2017] [Indexed: 01/08/2023] Open
Abstract
Exposure to repetitive low‐frequency electromagnetic field (LF‐EMF) shows promise as a non‐invasive approach to treat various sensory and neurological disorders. Despite considerable progress in the development of modern stimulation devices, there is a limited understanding of the mechanisms underlying their biological effects and potential targets at the cellular level. A significant impact of electromagnetic field on voltage‐gated calcium channels and downstream signalling pathways has been convincingly demonstrated in many distinct cell types. However, evidence for clear effects on primary sensory neurons that particularly may be responsible for the analgesic actions of LF‐EMF is still lacking. Here, we used F11 cells derived from dorsal root ganglia neurons as an in vitro model of peripheral sensory neurons and three different protocols of high‐induction magnetic stimulation to determine the effects on chemical responsiveness and spontaneous activity. We show that short‐term (<180 sec.) exposure of F11 cells to LF‐EMF reduces calcium transients in response to bradykinin, a potent pain‐producing inflammatory agent formed at sites of injury. Moreover, we characterize an immediate and reversible potentiating effect of LF‐EMF on neuronal spontaneous activity. Our results provide new evidence that electromagnetic field may directly modulate the activity of sensory neurons and highlight the potential of sensory neuron‐derived cell line as a tool for studying the underlying mechanisms at the cellular and molecular level.
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Affiliation(s)
- Jaroslav Prucha
- Department of Information and Communication Technologies in Medicine, Czech Technical University in Prague, Prague, Czech Republic.,Department of Health Care Disciplines and Population Protection, Faculty of Biomedical Engineering, Czech Technical University in Prague, Prague, Czech Republic
| | - Jan Krusek
- Department of Cellular Neurophysiology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Ivan Dittert
- Department of Cellular Neurophysiology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Viktor Sinica
- Department of Cellular Neurophysiology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Anna Kadkova
- Department of Cellular Neurophysiology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Viktorie Vlachova
- Department of Cellular Neurophysiology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
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43
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Muttenthaler M, Andersson Å, Vetter I, Menon R, Busnelli M, Ragnarsson L, Bergmayr C, Arrowsmith S, Deuis JR, Chiu HS, Palpant NJ, O'Brien M, Smith TJ, Wray S, Neumann ID, Gruber CW, Lewis RJ, Alewood PF. Subtle modifications to oxytocin produce ligands that retain potency and improved selectivity across species. Sci Signal 2017; 10:10/508/eaan3398. [PMID: 29208680 DOI: 10.1126/scisignal.aan3398] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oxytocin and vasopressin mediate various physiological functions that are important for osmoregulation, reproduction, cardiovascular function, social behavior, memory, and learning through four G protein-coupled receptors that are also implicated in high-profile disorders. Targeting these receptors is challenging because of the difficulty in obtaining ligands that retain selectivity across rodents and humans for translational studies. We identified a selective and more stable oxytocin receptor (OTR) agonist by subtly modifying the pharmacophore framework of human oxytocin and vasopressin. [Se-Se]-oxytocin-OH displayed similar potency to oxytocin but improved selectivity for OTR, an effect that was retained in mice. Centrally infused [Se-Se]-oxytocin-OH potently reversed social fear in mice, confirming that this action was mediated by OTR and not by V1a or V1b vasopressin receptors. In addition, [Se-Se]-oxytocin-OH produced a more regular contraction pattern than did oxytocin in a preclinical labor induction and augmentation model using myometrial strips from cesarean sections. [Se-Se]-oxytocin-OH had no activity in human cardiomyocytes, indicating a potentially improved safety profile and therapeutic window compared to those of clinically used oxytocin. In conclusion, [Se-Se]-oxytocin-OH is a novel probe for validating OTR as a therapeutic target in various biological systems and is a promising new lead for therapeutic development. Our medicinal chemistry approach may also be applicable to other peptidergic signaling systems with similar selectivity issues.
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Affiliation(s)
- Markus Muttenthaler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia. .,Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Åsa Andersson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.,School of Pharmacy, The University of Queensland, Brisbane, Queensland 4104, Australia
| | - Rohit Menon
- Department of Behavioral and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, 93053 Regensburg, Germany
| | - Marta Busnelli
- CNR-Institute of Neuroscience, 20129 Milan, Italy.,Department of Biotechnology and Translational Medicine, University of Milan, 20129 Milan, Italy
| | - Lotten Ragnarsson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Christian Bergmayr
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Sarah Arrowsmith
- Department of Cellular and Molecular Physiology, Harris-Wellbeing Preterm Birth Centre, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Han Sheng Chiu
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Nathan J Palpant
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Margaret O'Brien
- National Centre for Biomedical Engineering Science, National University of Ireland, Galway H91 CF50, Ireland
| | - Terry J Smith
- National Centre for Biomedical Engineering Science, National University of Ireland, Galway H91 CF50, Ireland
| | - Susan Wray
- Department of Cellular and Molecular Physiology, Harris-Wellbeing Preterm Birth Centre, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
| | - Inga D Neumann
- Department of Behavioral and Molecular Neurobiology, Regensburg Center of Neuroscience, University of Regensburg, 93053 Regensburg, Germany
| | - Christian W Gruber
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria.,School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Paul F Alewood
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
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44
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Heusinkveld HJ, Westerink RH. Comparison of different in vitro cell models for the assessment of pesticide-induced dopaminergic neurotoxicity. Toxicol In Vitro 2017; 45:81-88. [DOI: 10.1016/j.tiv.2017.07.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 05/17/2017] [Accepted: 07/29/2017] [Indexed: 01/10/2023]
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45
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Jin A, Dekan Z, Smout MJ, Wilson D, Dutertre S, Vetter I, Lewis RJ, Loukas A, Daly NL, Alewood PF. Conotoxin Φ‐MiXXVIIA from the Superfamily G2 Employs a Novel Cysteine Framework that Mimics Granulin and Displays Anti‐Apoptotic Activity. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201708927] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ai‐Hua Jin
- Institute for Molecular Bioscience The University of Queensland St Lucia Queensland 4072 Australia
| | - Zoltan Dekan
- Institute for Molecular Bioscience The University of Queensland St Lucia Queensland 4072 Australia
| | - Michael J. Smout
- Centre for Biodiscovery and Molecular Development of Therapeutics, AITHM James Cook University Smithfield, Cairns QLD 4878 Australia
| | - David Wilson
- Centre for Biodiscovery and Molecular Development of Therapeutics, AITHM James Cook University Smithfield, Cairns QLD 4878 Australia
| | - Sébastien Dutertre
- Institute for Molecular Bioscience The University of Queensland St Lucia Queensland 4072 Australia
- Institut des Biomolécules Max Mousseron, UMR 5247 Université Montpellier, CNRS Place Eugène Bataillon 34095 Montpellier Cedex 5 France
| | - Irina Vetter
- Institute for Molecular Bioscience The University of Queensland St Lucia Queensland 4072 Australia
| | - Richard J. Lewis
- Institute for Molecular Bioscience The University of Queensland St Lucia Queensland 4072 Australia
| | - Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, AITHM James Cook University Smithfield, Cairns QLD 4878 Australia
| | - Norelle L. Daly
- Centre for Biodiscovery and Molecular Development of Therapeutics, AITHM James Cook University Smithfield, Cairns QLD 4878 Australia
| | - Paul F. Alewood
- Institute for Molecular Bioscience The University of Queensland St Lucia Queensland 4072 Australia
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46
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Abstract
Crotalphine is a structural analogue to a novel analgesic peptide that was first identified in the crude venom from the South American rattlesnake Crotalus durissus terrificus. Although crotalphine's analgesic effect is well established, its direct mechanism of action remains unresolved. The aim of the present study was to investigate the effect of crotalphine on ion channels in peripheral pain pathways. We found that picomolar concentrations of crotalphine selectively activate heterologously expressed and native TRPA1 ion channels. TRPA1 activation by crotalphine required intact N-terminal cysteine residues and was followed by strong and long-lasting desensitization of the channel. Homologous desensitization of recombinant TRPA1 and heterologous desensitization in cultured dorsal root ganglia neurons was observed. Likewise, crotalphine acted on peptidergic TRPA1-expressing nerve endings ex vivo as demonstrated by suppression of calcitonin gene-related peptide release from the trachea and in vivo by inhibition of chemically induced and inflammatory hypersensitivity in mice. The crotalphine-mediated desensitizing effect was abolished by the TRPA1 blocker HC030031 and absent in TRPA1-deficient mice. Taken together, these results suggest that crotalphine is the first peptide to mediate antinociception selectively and at subnanomolar concentrations by targeting TRPA1 ion channels.
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47
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Jin AH, Dekan Z, Smout MJ, Wilson D, Dutertre S, Vetter I, Lewis RJ, Loukas A, Daly NL, Alewood PF. Conotoxin Φ-MiXXVIIA from the Superfamily G2 Employs a Novel Cysteine Framework that Mimics Granulin and Displays Anti-Apoptotic Activity. Angew Chem Int Ed Engl 2017; 56:14973-14976. [PMID: 28984021 DOI: 10.1002/anie.201708927] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Indexed: 12/12/2022]
Abstract
Conotoxins are a large family of disulfide-rich peptides that contain unique cysteine frameworks that target a broad range of ion channels and receptors. We recently discovered the 33-residue conotoxin Φ-MiXXVIIA from Conus miles with a novel cysteine framework comprising three consecutive cysteine residues and four disulfide bonds. Regioselective chemical synthesis helped decipher the disulfide bond connectivity and the structure of Φ-MiXXVIIA was determined by NMR spectroscopy. The 3D structure displays a unique topology containing two β-hairpins that resemble the N-terminal domain of granulin. Similar to granulin, Φ-MiXXVIIA promotes cell proliferation (EC50 17.85 μm) while inhibiting apoptosis (EC50 2.2 μm). Additional framework XXVII sequences were discovered with homologous signal peptides that define the new conotoxin superfamily G2. The novel structure and biological activity of Φ-MiXXVIIA expands the repertoire of disulfide-rich conotoxins that recognize mammalian receptors.
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Affiliation(s)
- Ai-Hua Jin
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Zoltan Dekan
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Michael J Smout
- Centre for Biodiscovery and Molecular Development of Therapeutics, AITHM, James Cook University, Smithfield, Cairns, QLD, 4878, Australia
| | - David Wilson
- Centre for Biodiscovery and Molecular Development of Therapeutics, AITHM, James Cook University, Smithfield, Cairns, QLD, 4878, Australia
| | - Sébastien Dutertre
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, 4072, Australia.,Institut des Biomolécules Max Mousseron, UMR 5247, Université Montpellier, CNRS, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, AITHM, James Cook University, Smithfield, Cairns, QLD, 4878, Australia
| | - Norelle L Daly
- Centre for Biodiscovery and Molecular Development of Therapeutics, AITHM, James Cook University, Smithfield, Cairns, QLD, 4878, Australia
| | - Paul F Alewood
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, 4072, Australia
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48
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Hashemian S, Alhouayek M, Fowler CJ. TLR4 receptor expression and function in F11 dorsal root ganglion × neuroblastoma hybrid cells. Innate Immun 2017; 23:687-696. [PMID: 28958207 DOI: 10.1177/1753425917732824] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
TLR4 respond to bacterial LPS to produce inflammatory cytokines. TLR4 are expressed in dorsal root ganglia and play a role in pain. F11 dorsal root ganglia × mouse neuroblastoma cells possess many of the properties seen in nociceptive dorsal root ganglia neuronal cells. Here, we investigated the effect of 2 h and 6 h treatment with LPS upon the expression of inflammatory proteins in undifferentiated and differentiated F11 cells. The cells expressed mRNA for TRL4 (mouse, not rat) and proteins involved in TLR4 signaling. TLR4 expression was confirmed using immunohistochemistry. LPS produced modest increases in mouse and rat IL-6 and in mouse cyclooxygenase-2 levels in undifferentiated cells, but did not significantly affect mouse TNF-α expression. This contrasts with the robust effects of LPS upon cyclooxygenase-2 expression in cultured dorsal root ganglia neurons. F11 cells expressed the endocannabinoid metabolizing enzymes fatty acid amide hydrolase and N-acylethanolamine acid amidase (both murine), which were functionally active. These data suggest that F11 cells are not a useful model for the study of LPS-mediated effects but may be useful for the study of endocannabinoid catabolism.
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Affiliation(s)
- Sanaz Hashemian
- Department of Pharmacology and Clinical Neuroscience, Pharmacology Unit, Umeå University, Umeå, Sweden
| | - Mireille Alhouayek
- Department of Pharmacology and Clinical Neuroscience, Pharmacology Unit, Umeå University, Umeå, Sweden
| | - Christopher J Fowler
- Department of Pharmacology and Clinical Neuroscience, Pharmacology Unit, Umeå University, Umeå, Sweden
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49
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Zatkova M, Reichova A, Bacova Z, Strbak V, Kiss A, Bakos J. Neurite Outgrowth Stimulated by Oxytocin Is Modulated by Inhibition of the Calcium Voltage-Gated Channels. Cell Mol Neurobiol 2017; 38:371-378. [DOI: 10.1007/s10571-017-0503-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/06/2017] [Indexed: 11/29/2022]
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50
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Windley MJ, Vetter I, Lewis RJ, Nicholson GM. Lethal effects of an insecticidal spider venom peptide involve positive allosteric modulation of insect nicotinic acetylcholine receptors. Neuropharmacology 2017; 127:224-242. [PMID: 28396143 DOI: 10.1016/j.neuropharm.2017.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/28/2017] [Accepted: 04/06/2017] [Indexed: 01/17/2023]
Abstract
κ-Hexatoxins (κ-HXTXs) are a family of excitotoxic insect-selective neurotoxins from Australian funnel-web spiders that are lethal to a wide range of insects, but display no toxicity towards vertebrates. The prototypic κ-HXTX-Hv1c selectively blocks native and expressed cockroach large-conductance calcium-activated potassium (BKCa or KCa1.1) channels, but not their mammalian orthologs. Despite this potent and selective action on insect KCa1.1 channels, we found that the classical KCa1.1 blockers paxilline, charybdotoxin and iberiotoxin, which all block insect KCa1.1 channels, are not lethal in crickets. We therefore used whole-cell patch-clamp analysis of cockroach dorsal unpaired median (DUM) neurons to study the effects of κ-HXTX-Hv1c on sodium-activated (KNa), delayed-rectifier (KDR) and 'A-type' transient (KA) K+ channels. 1 μM κ-HXTX-Hv1c failed to significantly inhibit cockroach KNa and KDR channels, but did cause a 30 ± 7% saturating inhibition of KA channel currents, possibly via a Kv4 (Shal-like) action. However, this modest action at such a high concentration of κ-HXTX-Hv1c would indicate a different lethal target. Accordingly, we assessed the actions of κ-HXTX-Hv1c on neurotransmitter-gated ion channels in cockroach DUM neurons. We found that κ-HXTX-Hv1c failed to produce any major effects on GABAA or glutamate-Cl receptors but dramatically slowed nicotine-evoked ACh receptor (nAChR) current decay and reversed nAChR desensitization. These actions occurred without any alterations to nAChR current amplitude or the nicotine concentration-response curve, and are consistent with a positive allosteric modulation of nAChRs. κ-HXTX-Hv1c therefore represents the first venom peptide that selectively modulates insect nAChRs with a mode of action similar to the excitotoxic insecticide spinosyn A. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- Monique J Windley
- School of Life Sciences, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, University of Queensland, Brisbane St. Lucia, QLD 4072, Australia; School of Pharmacy, University of Queensland, Brisbane St. Lucia, QLD 4072, Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience, University of Queensland, Brisbane St. Lucia, QLD 4072, Australia
| | - Graham M Nicholson
- School of Life Sciences, University of Technology Sydney, Broadway, NSW 2007, Australia.
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