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Rhodes LL, Smith KF, Murray JS, Passfield EMF, D'Archino R, Nelson W, Nishimura T, Thompson L, Trnski T. Sub-tropical benthic/epiphytic dinoflagellates of Aotearoa New Zealand and Rangitāhua Kermadec Islands. HARMFUL ALGAE 2023; 128:102494. [PMID: 37714580 DOI: 10.1016/j.hal.2023.102494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/17/2023]
Abstract
Temperatures and temperature anomalies have been increasing in the sub-tropical regions of Aotearoa New Zealand and these changes may impact on harmful algal bloom (HAB) events. Benthic and epiphytic dinoflagellates, particularly the toxin producers, are the focus of this study as it is predicted that under future climate conditions they may produce more toxins or marine animals may become more susceptible to them. The results of past expeditions to Rangitāhua Kermadec Islands and sampling trips to Northland, Aotearoa New Zealand, are summarised and the results of the most recent trips to both regions are presented. The macroalgal habitats of the dinoflagellates are also characterised. Dinoflagellate species not previously identified in Rangitāhua include Coolia canariensis, C. palmyrensis, and C. tropicalis, all identified by DNA sequencing of the large subunit ribosomal RNA region. Gambierdiscus polynesiensis was again isolated and produced 44-methylgambierone and gambierone, and one isolate produced ciguatoxins, the cause of Ciguatera Poisoning. An Ostreopsis tairoto isolate, as analysed by the oxidative cleavage method, produced a palytoxin (PLTX)-like amine oxidation fragment, but when analysed for PLTX-like analogues using a new intact method none were detected indicating an 'unknown' PLTX-like compound is produced by this isolate. Isolates of O. cf. siamensis (Ostreopsis sp. 9), collected in Northland, were also analysed using the oxidative cleavage method, with the common PLTX-like amine fragment and the amide fragment corresponding to bishomoPLTX detected in all isolates. Again, the intact method indicated no detections in the isolates, again suggesting an unknown compound was being produced by these isolates. Prorocentrum hoffmannianum isolates produced okadaic acid (OA) and isoDTX-1 and P. lima isolates produced OA, DTX-1, and isoDTX-1. It is expected that new species of potentially harmful, benthic dinoflagellates will continue to be recorded in Aotearoa New Zealand and the results from Rangitāhua provide a guide to the HAB species to expect in sub-tropical Northland as the oceans continue to warm.
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Affiliation(s)
- Lesley L Rhodes
- Cawthron Institute, 98 Halifax St East, PB 2, The Wood, Nelson 7010, New Zealand.
| | - Kirsty F Smith
- Cawthron Institute, 98 Halifax St East, PB 2, The Wood, Nelson 7010, New Zealand
| | - J Sam Murray
- Cawthron Institute, 98 Halifax St East, PB 2, The Wood, Nelson 7010, New Zealand
| | | | - Roberta D'Archino
- National Institute of Water and Atmospheric Research Ltd, PB 14-901, Wellington 6241, New Zealand
| | - Wendy Nelson
- National Institute of Water and Atmospheric Research Ltd, PB 14-901, Wellington 6241, New Zealand; School of Biological Sciences, University of Auckland, Auckland 1014, New Zealand
| | - Tomohiro Nishimura
- Cawthron Institute, 98 Halifax St East, PB 2, The Wood, Nelson 7010, New Zealand; Laboratory of Aquatic Environmental Science (LAQUES), Faculty of Agriculture and Marine Science, Kochi University, 200 Otsu, Monobe, Nankoku, Kochi 783-8502, Japan
| | - Lucy Thompson
- Cawthron Institute, 98 Halifax St East, PB 2, The Wood, Nelson 7010, New Zealand
| | - Tom Trnski
- Auckland War Memorial Museum, PB 92018, Victoria Street West, Auckland 1010, New Zealand
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Clarke MR, Jones B, Squires CLM, Imhoff FM, Harwood DT, Rhodes L, Selwood AI, McNabb PS, Baird SK. Cyclic Imine Pinnatoxin G is Cytotoxic to Cancer Cell Lines via Nicotinic Acetylcholine Receptor-Driven Classical Apoptosis. JOURNAL OF NATURAL PRODUCTS 2021; 84:2035-2042. [PMID: 34170700 DOI: 10.1021/acs.jnatprod.1c00418] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Pinnatoxin G is a cyclic imine neurotoxin produced by dinoflagellates that has been reported in shellfish. Like other members of the pinnatoxin family, it has been shown to have its effects via antagonism of the nicotinic acetylcholine receptors, with preferential binding to the α7 subunit often upregulated in cancer. Because increased activity of α7 nicotinic acetylcholine receptors contributes to increased growth and resistance to apoptosis, the effect of pinnatoxin G on cancer cell viability was tested. In a panel of six cancer cell lines, all cell types lost viability, but HT29 colon cancer and LN18 and U373 glioma cell lines were more sensitive than MDA-MB-231 breast cancer cells, PC3 prostate cancer cells, and U87 glioma cells, correlating with expression levels of α7, α4, and α9 nicotinic acetylcholine receptors. Some loss of cell viability could be attributed to cell cycle arrest, but significant levels of classical apoptosis were found, characterized by caspase activity, phosphatidylserine exposure, mitochondrial membrane permeability, and fragmented DNA. Intracellular Ca2+ levels also dropped immediately upon pinnatoxin G treatment, which may relate to antagonism of nicotinic acetylcholine receptor-mediated Ca2+ inflow. In conclusion, pinnatoxin G can decrease cancer cell viability, with both cytostatic and cytotoxic effects.
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Affiliation(s)
- Mitchell R Clarke
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, PO Box 56, Dunedin 9016, New Zealand
| | - Ben Jones
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, PO Box 56, Dunedin 9016, New Zealand
| | - Chloe L M Squires
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, PO Box 56, Dunedin 9016, New Zealand
| | - Floriane M Imhoff
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, PO Box 56, Dunedin 9016, New Zealand
| | - D Tim Harwood
- Cawthron Institute, Private Bag 2, Nelson 7040, New Zealand
| | - Lesley Rhodes
- Cawthron Institute, Private Bag 2, Nelson 7040, New Zealand
| | | | - Paul S McNabb
- Cawthron Institute, Private Bag 2, Nelson 7040, New Zealand
| | - Sarah K Baird
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, PO Box 56, Dunedin 9016, New Zealand
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Arnich N, Abadie E, Delcourt N, Fessard V, Fremy JM, Hort V, Lagrange E, Maignien T, Molgó J, Peyrat MB, Vernoux JP, Mattei C. Health risk assessment related to pinnatoxins in French shellfish. Toxicon 2020; 180:1-10. [DOI: 10.1016/j.toxicon.2020.03.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 03/16/2020] [Accepted: 03/25/2020] [Indexed: 02/02/2023]
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Sosa S, Pelin M, Cavion F, Hervé F, Hess P, Tubaro A. Acute Oral Toxicity of Pinnatoxin G in Mice. Toxins (Basel) 2020; 12:toxins12020087. [PMID: 32012834 PMCID: PMC7076786 DOI: 10.3390/toxins12020087] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/21/2020] [Accepted: 01/23/2020] [Indexed: 01/18/2023] Open
Abstract
Pinnatoxin G (PnTx-G) is a marine cyclic imine toxin produced by the dinoflagellate Vulcanodinium rugosum, frequently detected in edible shellfish from Ingril Lagoon (France). As other pinnatoxins, to date, no human poisonings ascribed to consumption of PnTx-G contaminated seafood have been reported, despite its potent antagonism at nicotinic acetylcholine receptors and its high and fast-acting toxicity after intraperitoneal or oral administration in mice. The hazard characterization of PnTx-G by oral exposure is limited to a single acute toxicity study recording lethality and clinical signs in non-fasted mice treated by gavage or through voluntary food ingestion, which showed differences in PnTx-G toxic potency. Thus, an acute toxicity study was carried out using 3 h-fasted CD-1 female mice, administered by gavage with PnTx-G (8–450 µg kg−1). At the dose of 220 µg kg−1 and above, the toxin induced a rapid onset of clinical signs (piloerection, prostration, hypothermia, abdominal breathing, paralysis of the hind limbs, and cyanosis), leading to the death of mice within 30 min. Except for moderate mucosal degeneration in the small intestine recorded at doses of 300 µg kg−1, the toxin did not induce significant morphological changes in the other main organs and tissues, or alterations in blood chemistry parameters. This acute oral toxicity study allowed to calculate an oral LD50 for PnTx-G equal to 208 μg kg−1 (95% confidence limits: 155–281 µg kg−1) and to estimate a provisional NOEL of 120 µg kg−1.
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Affiliation(s)
- Silvio Sosa
- Department of Life Sciences, University of Trieste, Via A. Valerio 6, 34127 Trieste, Italy; (M.P.); (F.C.); (A.T.)
- Correspondence: ; Tel.: +39-040-558-8836
| | - Marco Pelin
- Department of Life Sciences, University of Trieste, Via A. Valerio 6, 34127 Trieste, Italy; (M.P.); (F.C.); (A.T.)
| | - Federica Cavion
- Department of Life Sciences, University of Trieste, Via A. Valerio 6, 34127 Trieste, Italy; (M.P.); (F.C.); (A.T.)
| | - Fabienne Hervé
- Ifremer, Laboratoire Phycotoxines, Centre Atlantique, 44311 Nantes CEDEX, France; (F.H.); (P.H.)
| | - Philipp Hess
- Ifremer, Laboratoire Phycotoxines, Centre Atlantique, 44311 Nantes CEDEX, France; (F.H.); (P.H.)
| | - Aurelia Tubaro
- Department of Life Sciences, University of Trieste, Via A. Valerio 6, 34127 Trieste, Italy; (M.P.); (F.C.); (A.T.)
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Delcourt N, Lagrange E, Abadie E, Fessard V, Frémy JM, Vernoux JP, Peyrat MB, Maignien T, Arnich N, Molgó J, Mattei C. Pinnatoxins' Deleterious Effects on Cholinergic Networks: From Experimental Models to Human Health. Mar Drugs 2019; 17:md17070425. [PMID: 31330850 PMCID: PMC6669724 DOI: 10.3390/md17070425] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/17/2019] [Accepted: 07/17/2019] [Indexed: 12/24/2022] Open
Abstract
Pinnatoxins (PnTXs) are emerging neurotoxins that were discovered about 30 years ago. They are solely produced by the marine dinoflagellate Vulcanodinium rugosum, and may be transferred into the food chain, as they have been found in various marine invertebrates, including bivalves. No human intoxication has been reported to date although acute toxicity was induced by PnTxs in rodents. LD50 values have been estimated for the different PnTXs through the oral route. At sublethal doses, all symptoms are reversible, and no neurological sequelae are visible. These symptoms are consistent with impairment of central and peripheral cholinergic network functions. In fact, PnTXs are high-affinity competitive antagonists of nicotinic acetylcholine receptors (nAChRs). Moreover, their lethal effects are consistent with the inhibition of muscle nAChRs, inducing respiratory distress and paralysis. Human intoxication by ingestion of PnTXs could result in various symptoms observed in episodes of poisoning with natural nAChR antagonists. This review updates the available data on PnTX toxicity with a focus on their mode of action on cholinergic networks and suggests the effects that could be extrapolated on human physiology.
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Affiliation(s)
- Nicolas Delcourt
- Poison Control Centre, Toulouse-Purpan University Hospital and Toulouse NeuroImaging Centre (ToNIC), INSERM1214, Toulouse-Purpan University Hospital, 31059 Toulouse, France
| | - Emmeline Lagrange
- Department of Neurology, Reference Center of Neuromuscular Disease, Grenoble University Hospital, 38000 Grenoble, France
| | - Eric Abadie
- Laboratoire Environnement Ressources du Languedoc-Roussillon, Centre for Marine Biodiversity, Exploitation and Conservation (MARBEC), IRD, Institut Français de Recherche pour l'Exploitation de la Mer (Ifremer), CNRS, Université de Montpellier, CS30171, 34200 Sete Cedex 03, France
| | - Valérie Fessard
- Toxicology of Contaminants Unit, ANSES-French Agency for Food, Environmental and Occupational Health & Safety, 35306 Fougères, France
| | - Jean-Marc Frémy
- Retired from ANSES-French Agency for Food, Environmental and Occupational Health & Safety, 94701 Maisons-Alfort, France
| | - Jean-Paul Vernoux
- Research Unit EA 4651 Aliments Bioprocédés Toxicologie Environnements (ABTE), Normandie University, 14000 Caen, France
| | - Marie-Bénédicte Peyrat
- Risk Assessment Department, ANSES-French Agency for Food, Environmental and Occupational Health & Safety, 94701 Maisons-Alfort, France
| | - Thomas Maignien
- Risk Assessment Department, ANSES-French Agency for Food, Environmental and Occupational Health & Safety, 94701 Maisons-Alfort, France
| | - Nathalie Arnich
- Risk Assessment Department, ANSES-French Agency for Food, Environmental and Occupational Health & Safety, 94701 Maisons-Alfort, France
| | - Jordi Molgó
- Institut des Sciences du Vivant Frédéric Joliot, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), Commissariat à l'Energie Atomique et aux énergies alternatives (CEA) Saclay, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.
- Institut des Neurosciences Paris-Saclay, Centre National de la Recherche Scientifique (CNRS), UMR 9197 CNRS/Université Paris-Sud, F-91198 Gif-sur-Yvette, France.
| | - César Mattei
- Mitochondrial and Cardiovascular Pathophysiology (MITOVASC), Cardiovascular Mechanotransduction, UMR CNRS 6015, INSERM U1083, Angers University, 49045 Angers, France.
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Benoit E, Couesnon A, Lindovsky J, Iorga BI, Aráoz R, Servent D, Zakarian A, Molgó J. Synthetic Pinnatoxins A and G Reversibly Block Mouse Skeletal Neuromuscular Transmission In Vivo and In Vitro. Mar Drugs 2019; 17:md17050306. [PMID: 31137661 PMCID: PMC6562580 DOI: 10.3390/md17050306] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 05/17/2019] [Accepted: 05/21/2019] [Indexed: 12/14/2022] Open
Abstract
Pinnatoxins (PnTXs) A-H constitute an emerging family belonging to the cyclic imine group of phycotoxins. Interest has been focused on these fast-acting and highly-potent toxins because they are widely found in contaminated shellfish. Despite their highly complex molecular structure, PnTXs have been chemically synthetized and demonstrated to act on various nicotinic acetylcholine receptor (nAChR) subtypes. In the present work, PnTX-A, PnTX-G and analogue, obtained by chemical synthesis with a high degree of purity (>98%), have been studied in vivo and in vitro on adult mouse and isolated nerve-muscle preparations expressing the mature muscle-type (α1)2β1δε nAChR. The results show that PnTX-A and G acted on the neuromuscular system of anesthetized mice and blocked the compound muscle action potential (CMAP) in a dose- and time-dependent manner, using a minimally invasive electrophysiological method. The CMAP block produced by both toxins in vivo was reversible within 6–8 h. PnTX-A and G, applied to isolated extensor digitorum longus nerve-muscle preparations, blocked reversibly isometric twitches evoked by nerve stimulation. The action of PnTX-A was reversed by 3,4-diaminopyridine. Both toxins exerted no direct action on muscle fibers, as revealed by direct muscle stimulation. PnTX-A and G blocked synaptic transmission at mouse neuromuscular junctions and PnTX-A amino ketone analogue (containing an open form of the imine ring) had no effect on neuromuscular transmission. These results indicate the importance of the cyclic imine for interacting with the adult mammalian muscle-type nAChR. Modeling and docking studies revealed molecular determinants responsible for the interaction of PnTXs with the muscle-type nAChR.
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Affiliation(s)
- Evelyne Benoit
- Commissariat à l'Energie Atomique et aux énergies Alternatives (CEA), Institut des Sciences du Vivant Frédéric Joliot, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), CEA de Saclay, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.
- Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences Paris-Saclay (Neuro-PSI), UMR 9197 CNRS/Université Paris-Sud, F-91198 Gif-sur-Yvette, France.
| | - Aurélie Couesnon
- Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences Paris-Saclay (Neuro-PSI), UMR 9197 CNRS/Université Paris-Sud, F-91198 Gif-sur-Yvette, France.
| | - Jiri Lindovsky
- Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences Paris-Saclay (Neuro-PSI), UMR 9197 CNRS/Université Paris-Sud, F-91198 Gif-sur-Yvette, France.
| | - Bogdan I Iorga
- Centre National de la Recherche Scientifique (CNRS), Institut de Chimie des Substances Naturelles, UPR 2301, Labex LERMIT, F-91198 Gif-sur-Yvette, France.
| | - Rómulo Aráoz
- Commissariat à l'Energie Atomique et aux énergies Alternatives (CEA), Institut des Sciences du Vivant Frédéric Joliot, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), CEA de Saclay, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.
- Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences Paris-Saclay (Neuro-PSI), UMR 9197 CNRS/Université Paris-Sud, F-91198 Gif-sur-Yvette, France.
| | - Denis Servent
- Commissariat à l'Energie Atomique et aux énergies Alternatives (CEA), Institut des Sciences du Vivant Frédéric Joliot, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), CEA de Saclay, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.
| | - Armen Zakarian
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA.
| | - Jordi Molgó
- Commissariat à l'Energie Atomique et aux énergies Alternatives (CEA), Institut des Sciences du Vivant Frédéric Joliot, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), CEA de Saclay, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.
- Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences Paris-Saclay (Neuro-PSI), UMR 9197 CNRS/Université Paris-Sud, F-91198 Gif-sur-Yvette, France.
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Zendong Z, Sibat M, Herrenknecht C, Hess P, McCarron P. Relative molar response of lipophilic marine algal toxins in liquid chromatography/electrospray ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:1453-1461. [PMID: 28582796 DOI: 10.1002/rcm.7918] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/01/2017] [Accepted: 06/01/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Accurate quantitative analysis of lipophilic toxins by liquid chromatography/mass spectrometry (LC/MS) requires calibration solution reference materials (RMs) for individual toxin analogs. Untargeted analysis is aimed at identifying a vast number of compounds and thus validation of fully quantitative untargeted methods is not feasible. However, a semi-quantitative approach allowing for profiling is still required and will be strengthened by knowledge of the relative molar response (RMR) of analogs in LC/MS with electrospray ionization (ESI). METHODS RMR factors were evaluated for toxins from the okadaic acid (OA/DTXs), yessotoxin (YTX), pectenotoxin (PTX), azaspiracid (AZA) and cyclic imine (CI) toxin groups, in both solvent standards and environmental sample extracts. Since compound ionization and fragmentation influences the MS response of toxins, RMRs were assessed under different chromatographic conditions (gradient, isocratic) and MS acquisition modes (SIM, SRM, All-ion, target MS/MS) on low- and high-resolution mass spectrometers. RESULTS In general, RMRs were not significantly impacted by chromatographic conditions (isocratic vs gradient), with the exception of DTX1. MS acquisition modes had a more significant impact, with PnTX-G and SPX differing notably. For a given toxin group, response factors were generally in the range of 0.5 to 2. The cyclic imines were an exception. CONCLUSIONS Differences in RMRs between toxins of a same chemical base structure were not significant enough to indicate major issues for non-targeted semi-quantitative analysis, where there is limited or no availability of standards for many compounds, and where high degrees of accuracy are not required. Differences in RMRs should be considered when developing methods that use a standard of a single analogue to quantitate other toxins from the same group.
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Affiliation(s)
- Zita Zendong
- Ifremer, Laboratoire Phycotoxines, Nantes, France
| | | | | | - Philipp Hess
- Ifremer, Laboratoire Phycotoxines, Nantes, France
| | - Pearse McCarron
- Measurement Science and Standards, National Research Council Canada, Halifax, NS, Canada
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Molgó J, Marchot P, Aráoz R, Benoit E, Iorga BI, Zakarian A, Taylor P, Bourne Y, Servent D. Cyclic imine toxins from dinoflagellates: a growing family of potent antagonists of the nicotinic acetylcholine receptors. J Neurochem 2017; 142 Suppl 2:41-51. [PMID: 28326551 DOI: 10.1111/jnc.13995] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/13/2017] [Accepted: 02/15/2017] [Indexed: 12/24/2022]
Abstract
We present an overview of the toxicological profile of the fast-acting, lipophilic macrocyclic imine toxins, an emerging family of organic compounds associated with algal blooms, shellfish contamination and neurotoxicity. Worldwide, shellfish contamination incidents are expanding; therefore, the significance of these toxins for the shellfish food industry deserves further study. Emphasis is directed to the dinoflagellate species involved in their production, their chemical structures, and their specific mode of interaction with their principal natural molecular targets, the nicotinic acetylcholine receptors, or with the soluble acetylcholine-binding protein, used as a surrogate receptor model. The dinoflagellates Karenia selliformis and Alexandrium ostenfeldii / A. peruvianum have been implicated in the biosynthesis of gymnodimines and spirolides, while Vulcanodinium rugosum is the producer of pinnatoxins and portimine. The cyclic imine toxins are characterized by a macrocyclic skeleton comprising 14-27 carbon atoms, flanked by two conserved moieties, the cyclic imine and the spiroketal ring system. These phycotoxins generally display high affinity and broad specificity for the muscle type and neuronal nicotinic acetylcholine receptors, a feature consistent with their binding site at the receptor subunit interfaces, composed of residues highly conserved among all nAChRs, and explaining the diverse toxicity among animal species. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
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Affiliation(s)
- Jordi Molgó
- Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette, France.,Institut des Neurosciences Paris-Saclay, UMR 9197, Centre National de la Recherche Scientifique (CNRS)/Université Paris-Sud, Gif-sur-Yvette Cedex, France
| | - Pascale Marchot
- Aix-Marseille Université / Centre National de la Recherche Scientifique, Architecture et Fonction des Macromolécules Biologiques laboratory, Marseille, France
| | - Rómulo Aráoz
- Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette, France.,Institut des Neurosciences Paris-Saclay, UMR 9197, Centre National de la Recherche Scientifique (CNRS)/Université Paris-Sud, Gif-sur-Yvette Cedex, France
| | - Evelyne Benoit
- Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette, France.,Institut des Neurosciences Paris-Saclay, UMR 9197, Centre National de la Recherche Scientifique (CNRS)/Université Paris-Sud, Gif-sur-Yvette Cedex, France
| | - Bogdan I Iorga
- Centre National de la Recherche Scientifique (CNRS), Institut de Chimie des Substances Naturelles, UPR 2301, Labex LERMIT, Gif-sur-Yvette, France
| | - Armen Zakarian
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California, USA
| | - Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Yves Bourne
- Aix-Marseille Université / Centre National de la Recherche Scientifique, Architecture et Fonction des Macromolécules Biologiques laboratory, Marseille, France
| | - Denis Servent
- Commissariat à l'Energie Atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette, France
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Couesnon A, Aráoz R, Iorga BI, Benoit E, Reynaud M, Servent D, Molgó J. The Dinoflagellate Toxin 20-Methyl Spirolide-G Potently Blocks Skeletal Muscle and Neuronal Nicotinic Acetylcholine Receptors. Toxins (Basel) 2016; 8:E249. [PMID: 27563924 PMCID: PMC5037475 DOI: 10.3390/toxins8090249] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/06/2016] [Accepted: 08/12/2016] [Indexed: 11/16/2022] Open
Abstract
The cyclic imine toxin 20-methyl spirolide G (20-meSPX-G), produced by the toxigenic dinoflagellate Alexandrium ostenfeldii/Alexandrium peruvianum, has been previously reported to contaminate shellfish in various European coastal locations, as revealed by mouse toxicity bioassay. The aim of the present study was to determine its toxicological profile and its molecular target selectivity. 20-meSPX-G blocked nerve-evoked isometric contractions in isolated mouse neuromuscular preparations, while it had no action on contractions elicited by direct electrical stimulation, and reduced reversibly nerve-evoked compound muscle action potential amplitudes in anesthetized mice. Voltage-clamp recordings in Xenopus oocytes revealed that 20-meSPX-G potently inhibited currents evoked by ACh on Torpedo muscle-type and human α7 nicotinic acetylcholine receptors (nAChR), whereas lower potency was observed in human α4β2 nAChR. Competition-binding assays showed that 20-meSPX-G fully displaced [³H]epibatidine binding to HEK-293 cells expressing the human α3β2 (Ki = 0.040 nM), whereas a 90-fold lower affinity was detected in human α4β2 nAChR. The spirolide displaced [(125)I]α-bungarotoxin binding to Torpedo membranes (Ki = 0.028 nM) and in HEK-293 cells expressing chick chimeric α7-5HT₃ nAChR (Ki = 0.11 nM). In conclusion, this is the first study to demonstrate that 20-meSPX-G is a potent antagonist of nAChRs, and its subtype selectivity is discussed on the basis of molecular docking models.
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MESH Headings
- Action Potentials
- Animals
- Binding Sites
- Binding, Competitive
- Bridged Bicyclo Compounds, Heterocyclic/metabolism
- Chickens
- Cholinergic Fibers/drug effects
- Cholinergic Fibers/metabolism
- Dose-Response Relationship, Drug
- Electric Stimulation
- Female
- HEK293 Cells
- Humans
- In Vitro Techniques
- Isometric Contraction/drug effects
- Mice
- Molecular Docking Simulation
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/innervation
- Muscle, Skeletal/metabolism
- Neuromuscular Junction/drug effects
- Neuromuscular Junction/metabolism
- Nicotinic Antagonists/chemistry
- Nicotinic Antagonists/metabolism
- Nicotinic Antagonists/toxicity
- Protein Binding
- Protein Conformation
- Pyridines/metabolism
- Receptors, Nicotinic/chemistry
- Receptors, Nicotinic/drug effects
- Receptors, Nicotinic/genetics
- Receptors, Nicotinic/metabolism
- Spiro Compounds/chemistry
- Spiro Compounds/metabolism
- Spiro Compounds/toxicity
- Structure-Activity Relationship
- Torpedo
- Transfection
- Xenopus laevis
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Affiliation(s)
- Aurélie Couesnon
- Institut des Neurosciences Paris-Saclay, UMR 9197 CNRS/Université Paris-Sud, F-91190 Gif-sur-Yvette, France.
| | - Rómulo Aráoz
- Institut des Neurosciences Paris-Saclay, UMR 9197 CNRS/Université Paris-Sud, F-91190 Gif-sur-Yvette, France.
- Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, bâtiment 152, F-91191 Gif-sur-Yvette, France.
| | - Bogdan I Iorga
- Centre National de la Recherche Scientifique (CNRS), Institut de Chimie des Substances Naturelles, UPR 2301, Labex LERMIT, F-91198 Gif-sur-Yvette, France.
| | - Evelyne Benoit
- Institut des Neurosciences Paris-Saclay, UMR 9197 CNRS/Université Paris-Sud, F-91190 Gif-sur-Yvette, France.
- Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, bâtiment 152, F-91191 Gif-sur-Yvette, France.
| | - Morgane Reynaud
- Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, bâtiment 152, F-91191 Gif-sur-Yvette, France.
| | - Denis Servent
- Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, bâtiment 152, F-91191 Gif-sur-Yvette, France.
| | - Jordi Molgó
- Institut des Neurosciences Paris-Saclay, UMR 9197 CNRS/Université Paris-Sud, F-91190 Gif-sur-Yvette, France.
- Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Biologie et Technologies de Saclay (IBITECS), Université Paris-Saclay, Service d'Ingénierie Moléculaire des Protéines, bâtiment 152, F-91191 Gif-sur-Yvette, France.
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10
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Visciano P, Schirone M, Berti M, Milandri A, Tofalo R, Suzzi G. Marine Biotoxins: Occurrence, Toxicity, Regulatory Limits and Reference Methods. Front Microbiol 2016; 7:1051. [PMID: 27458445 PMCID: PMC4933704 DOI: 10.3389/fmicb.2016.01051] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 06/23/2016] [Indexed: 01/08/2023] Open
Abstract
Harmful algal blooms are natural phenomena caused by the massive growth of phytoplankton that may contain highly toxic chemicals, the so-called marine biotoxins causing illness and even death to both aquatic organisms and humans. Their occurrence has been increased in frequency and severity, suggesting a worldwide public health risk. Marine biotoxins can accumulate in bivalve molluscs and regulatory limits have been set for some classes according to European Union legislation. These compounds can be distinguished in water- and fat-soluble molecules. The first group involves those of Paralytic Shellfish Poisoning and Amnesic Shellfish Poisoning, whereas the toxins soluble in fat can cause Diarrheic Shellfish Poisoning and Neurotoxic Shellfish Poisoning. Due to the lack of long-term toxicity studies, establishing tolerable daily intakes for any of these marine biotoxins was not possible, but an acute reference dose can be considered more appropriate, because these molecules show an acute toxicity. Dietary exposure assessment is linked both to the levels of marine biotoxins present in bivalve molluscs and the portion that could be eaten by consumers. Symptoms may vary from a severe gastrointestinal intoxication with diarrhea, nausea, vomiting, and abdominal cramps to neurological disorders such as ataxia, dizziness, partial paralysis, and respiratory distress. The official method for the detection of marine biotoxins is the mouse bioassay (MBA) showing some limits due to ethical restrictions and insufficient specificity. For this reason, the liquid chromatography-mass spectrometry method has replaced MBA as the reference technique. However, the monitoring of algal blooms producing marine biotoxins should be regularly assessed in order to obtain more reliable, accurate estimates of bloom toxicity and their potential impacts.
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Affiliation(s)
- Pierina Visciano
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo Teramo, Italy
| | - Maria Schirone
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo Teramo, Italy
| | - Miriam Berti
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale" Teramo, Italy
| | - Anna Milandri
- National Reference Laboratory for Marine Biotoxins, Fondazione Centro Ricerche Marine Cesenatico, Italy
| | - Rosanna Tofalo
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo Teramo, Italy
| | - Giovanna Suzzi
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo Teramo, Italy
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Hellyer SD, Indurthi D, Balle T, Runder-Varga V, Selwood AI, Tyndall JD, Chebib M, Rhodes L, Kerr DS. Pinnatoxins E, F and G target multiple nicotinic receptor subtypes. J Neurochem 2015; 135:479-91. [DOI: 10.1111/jnc.13245] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 06/16/2015] [Accepted: 06/24/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Shane D. Hellyer
- Department of Pharmacology and Toxicology; University of Otago School of Medical Sciences; Dunedin New Zealand
| | - Dinesh Indurthi
- Faculty of Pharmacy; University of Sydney; Sydney NSW Australia
| | - Thomas Balle
- Faculty of Pharmacy; University of Sydney; Sydney NSW Australia
| | | | | | - Joel D.A. Tyndall
- New Zealand's National School of Pharmacy; University of Otago; Dunedin New Zealand
| | - Mary Chebib
- Faculty of Pharmacy; University of Sydney; Sydney NSW Australia
| | | | - D. Steven Kerr
- Department of Pharmacology and Toxicology; University of Otago School of Medical Sciences; Dunedin New Zealand
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12
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Hellyer SD, Selwood AI, van Ginkel R, Munday R, Sheard P, Miles CO, Rhodes L, Kerr DS. In vitro labelling of muscle type nicotinic receptors using a fluorophore-conjugated pinnatoxin F derivative. Toxicon 2014; 87:17-25. [DOI: 10.1016/j.toxicon.2014.05.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 05/02/2014] [Accepted: 05/07/2014] [Indexed: 11/30/2022]
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