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Bourne Y, Sulzenbacher G, Chabaud L, Aráoz R, Radić Z, Conrod S, Taylor P, Guillou C, Molgó J, Marchot P. The Cyclic Imine Core Common to the Marine Macrocyclic Toxins Is Sufficient to Dictate Nicotinic Acetylcholine Receptor Antagonism. Mar Drugs 2024; 22:149. [PMID: 38667766 PMCID: PMC11050823 DOI: 10.3390/md22040149] [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: 02/13/2024] [Revised: 03/22/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024] Open
Abstract
Macrocyclic imine phycotoxins are an emerging class of chemical compounds associated with harmful algal blooms and shellfish toxicity. Earlier binding and electrophysiology experiments on nAChR subtypes and their soluble AChBP surrogates evidenced common trends for substantial antagonism, binding affinities, and receptor-subtype selectivity. Earlier, complementary crystal structures of AChBP complexes showed that common determinants within the binding nest at each subunit interface confer high-affinity toxin binding, while distinctive determinants from the flexible loop C, and either capping the nest or extending toward peripheral subsites, dictate broad versus narrow receptor subtype selectivity. From these data, small spiroimine enantiomers mimicking the functional core motif of phycotoxins were chemically synthesized and characterized. Voltage-clamp analyses involving three nAChR subtypes revealed preserved antagonism for both enantiomers, despite lower subtype specificity and binding affinities associated with faster reversibility compared with their macrocyclic relatives. Binding and structural analyses involving two AChBPs pointed to modest affinities and positional variability of the spiroimines, along with a range of AChBP loop-C conformations denoting a prevalence of antagonistic properties. These data highlight the major contribution of the spiroimine core to binding within the nAChR nest and confirm the need for an extended interaction network as established by the macrocyclic toxins to define high affinities and marked subtype specificity. This study identifies a minimal set of functional pharmacophores and binding determinants as templates for designing new antagonists targeting disease-associated nAChR subtypes.
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Affiliation(s)
- Yves Bourne
- Lab “Architecture et Fonction des Macromolécules Biologiques” (AFMB), Aix-Marseille Univ, CNRS, Faculté des Sciences Campus Luminy, 13288 Marseille cedex 09, France; (Y.B.); (G.S.)
| | - Gerlind Sulzenbacher
- Lab “Architecture et Fonction des Macromolécules Biologiques” (AFMB), Aix-Marseille Univ, CNRS, Faculté des Sciences Campus Luminy, 13288 Marseille cedex 09, France; (Y.B.); (G.S.)
| | - Laurent Chabaud
- Institut de Chimie des Substances Naturelles (ICSN), Univ Paris-Saclay, CNRS, 91198 Gif-sur-Yvette, France; (L.C.); (C.G.)
| | - Rómulo Aráoz
- Service d’Ingénierie Moléculaire pour la Santé (SIMoS) EMR CNRS 9004, Département Médicaments et Technologies pour la Santé, Institut des Sciences du Vivant Frédéric Joliot, CEA, INRAE, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; (R.A.); (J.M.)
| | - Zoran Radić
- Skaggs School of Pharmacy and Pharmaceutical Sciences (SSPPS), University of California San Diego, La Jolla, CA 92093-0751, USA; (Z.R.); (P.T.)
| | - Sandrine Conrod
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M), Aix Marseille Univ, CNRS, 13344 Marseille, France;
| | - Palmer Taylor
- Skaggs School of Pharmacy and Pharmaceutical Sciences (SSPPS), University of California San Diego, La Jolla, CA 92093-0751, USA; (Z.R.); (P.T.)
| | - Catherine Guillou
- Institut de Chimie des Substances Naturelles (ICSN), Univ Paris-Saclay, CNRS, 91198 Gif-sur-Yvette, France; (L.C.); (C.G.)
| | - Jordi Molgó
- Service d’Ingénierie Moléculaire pour la Santé (SIMoS) EMR CNRS 9004, Département Médicaments et Technologies pour la Santé, Institut des Sciences du Vivant Frédéric Joliot, CEA, INRAE, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; (R.A.); (J.M.)
| | - Pascale Marchot
- Lab “Architecture et Fonction des Macromolécules Biologiques” (AFMB), Aix-Marseille Univ, CNRS, Faculté des Sciences Campus Luminy, 13288 Marseille cedex 09, France; (Y.B.); (G.S.)
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille (CRN2M), Aix Marseille Univ, CNRS, 13344 Marseille, France;
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Ishihara J. Progress in Lewis-Acid-Templated Diels-Alder Reactions. Molecules 2024; 29:1187. [PMID: 38474699 DOI: 10.3390/molecules29051187] [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: 12/30/2023] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/14/2024] Open
Abstract
The synthesis of natural products with complicated architectures often requires the use of segments with functional groups that can be structurally transformed with the desired stereogenic centers. Bicyclic 𝛾-lactones have great potential as a suitable segment for natural product synthesis. However, the stereoselective construction of such functionalized bicyclic 𝛾-lactones is not as straightforward as one might expect. The template-mediated Diels-Alder reaction is one of the most powerful and versatile methods for providing bicyclic 𝛾-lactones with high regioselectivity and stereoselectivity. In this reaction, the diene is linked to the dienophile by a temporary tether, allowing the reaction to proceed efficiently, yielding a product that can be used for natural product synthesis. This review describes some important instances of the template-mediated Diels-Alder reaction and its application to the synthesis of biologically active compounds.
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Affiliation(s)
- Jun Ishihara
- Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 853-8521, Japan
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3
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Wang G, Qiu J, Li A, Ji Y, Zhang J. Apoptosis and oxidative stress of mouse breast carcinoma 4T1 and human intestinal epithelial Caco-2 cell lines caused by the phycotoxin gymnodimine-A. Chem Biol Interact 2023; 384:110727. [PMID: 37739050 DOI: 10.1016/j.cbi.2023.110727] [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: 04/10/2023] [Revised: 09/11/2023] [Accepted: 09/20/2023] [Indexed: 09/24/2023]
Abstract
Gymnodimine-A (GYM-A) is a cyclic imine phycotoxin produced by some marine dinoflagellates. It can cause rapid death of mice via intraperitoneal administration and frequently accumulate in shellfish potentially threatening human health. In this study, four different cell lines were exposed to GYM-A for the viability assessment. Results showed that GYM-A was cytotoxic with concentration-dependent pattern to each cell type, with mean IC50 values ranging from 1.39 to 2.79 μmol L-1. Results suggested that the loss of cell viability of 4T1 and Caco-2 cells was attributed to apoptosis. Furthermore, the collapse of mitochondrial membrane potential and caspases activation were observed in the GYM-A-treated cells. Reactive oxygen species (ROS) and lipid peroxides (LPO) levels were markedly increased in 4T1 and Caco-2 cells exposed to GYM-A at 2 μmol L-1, and the oxidative stress in 4T1 cells was more obvious than that in Caco-2 cells. Additionally, unusual ultrastructure impairment on mitochondria and mitophagosomes occurred in the GYM-A-treated cells. These results suggested that an ROS-mediated mitochondrial pathway for apoptosis and mitophagy was implicated in the cytotoxic effects induced by GYM-A. This is the first report to explore the cytotoxic mechanisms of GYM-A through apoptosis and oxidative stress, and it will provide theoretical foundations for the potential therapeutic applications of GYM-A.
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Affiliation(s)
- Guixiang Wang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Jiangbing Qiu
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao, 266100, China
| | - Aifeng Li
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao, 266100, China.
| | - Ying Ji
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Jingrui Zhang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
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Pedroni L, Dorne JLCM, Dall'Asta C, Dellafiora L. An in silico insight on the mechanistic aspects of gelsenicine toxicity: A reverse screening study pointing to the possible involvement of acetylcholine binding receptor. Toxicol Lett 2023; 386:1-8. [PMID: 37683806 DOI: 10.1016/j.toxlet.2023.09.003] [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: 02/21/2023] [Revised: 08/28/2023] [Accepted: 09/05/2023] [Indexed: 09/10/2023]
Abstract
Gelsedine-type alkaloids are highly toxic plant secondary metabolites produced by shrubs belonging to the Gelsemium genus. Gelsenicine is one of the most concerning gelsedine-type alkaloids with a lethal dose lower than 1 mg/Kg in mice. Several reported episodes of poisoning in livestock and fatality cases in humans due to the usage of Gelsemium plants extracts were reported. Also, gelsedine-type alkaloids were found in honey constituting a potential food safety issue. However, their toxicological understanding is scarce and the molecular mechanism underpinning their toxicity needs further investigations. In this context, an in silico approach based on reverse screening, docking and molecular dynamics successfully identified a possible gelsenicine biological target shedding light on its toxicodynamics. In line with the available crystallographic data, it emerged gelsenicine could target the acetylcholine binding protein possibly acting as a partial agonist against α7 nicotinic acetylcholine receptor (AChR). Overall, these results agreed with evidence previously reported and prioritized AChR for further dedicated analysis.
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Affiliation(s)
- Lorenzo Pedroni
- Department of Food and Drug, University of Parma, Parco Area delle Scienze 27/A, 43124 Parma, Italy
| | - Jean Lou C M Dorne
- Scientific Committee and Emerging Risks Unit, European Food Safety Authority, Via Carlo Magno 1A, Parma 43124, Italy
| | - Chiara Dall'Asta
- Department of Food and Drug, University of Parma, Parco Area delle Scienze 27/A, 43124 Parma, Italy
| | - Luca Dellafiora
- Department of Food and Drug, University of Parma, Parco Area delle Scienze 27/A, 43124 Parma, Italy.
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Earl ADW, Li FF, Ma C, Furkert DP, Brimble MA. Stereoselective synthesis of the spirocyclic core of 13-desmethyl spirolide C using an aza-Claisen rearrangement and an exo-selective Diels-Alder cycloaddition. Org Biomol Chem 2023; 21:1222-1234. [PMID: 36633001 DOI: 10.1039/d2ob01992b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
13-Desmethyl spirolide C is a marine natural product of the cyclic imine class that demonstrates remarkable bioactivity against several biomarkers of Alzheimer's Disease, which renders its [7,6]-spirocyclic imine pharmacophore of significant synthetic interest. This work describes a facile and efficient synthesis of the [7,6]-spirocyclic core of 13-desmethyl spirolide C from inexpensive starting materials, featuring an aza-Claisen rearrangement to simultaneously set both stereocentres of the dimethyl moiety with complete atom economy, and a highly exo-selective Diels-Alder cycloaddition to construct the challenging contiguous tertiary and quaternary stereocentres of the spirocyclic core of 13-desmethyl spirolide C. A comprehensive study of the key Diels-Alder reaction was also performed to evaluate the stereoselectivity and reactivity of various functionalised dienes and protected lactam dienophiles, wherein the first successful exo-selective Diels-Alder cycloaddition to construct spirocyclic structures using a bromodiene and α-exo-methylene dienophiles is reported. This strategy not only establishes a more efficient stereoselective access to the spirocyclic core that can be used for the total synthesis of 13-desmethyl spirolide C, but also serves as a sound platform for convenient preparations of a range of spirocyclic analogues required for a comprehensive biological evaluation of this desirable pharmacophore.
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Affiliation(s)
- Andrew D W Earl
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand.
| | - Freda F Li
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - Chao Ma
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand.
| | - Daniel P Furkert
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - Margaret A Brimble
- School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
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Stability and Chemical Conversion of the Purified Reference Material of Gymnodimine-A under Different Temperature and pH Conditions. Toxins (Basel) 2022; 14:toxins14110744. [PMID: 36355994 PMCID: PMC9695126 DOI: 10.3390/toxins14110744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 01/26/2023] Open
Abstract
Gymnodimines (GYMs) are a group of fast-acting phycotoxins and their toxicological effects on human beings are still unclear due to the lack of sufficiently well-characterized large quantities of purified toxins for toxicology studies. In this study, a certified reference material (CRM) of GYM-A was prepared from the dinoflagellate Karenia selliformis, followed by multi-step chromatography separation and purification. Subsequently, the stability of GYM-A in methanolic media was evaluated at different temperature (-20, 4, and 20 °C) and pH (3, 5, and 7) conditions for 8 months, and the conversion products of GYM-A were explored by liquid chromatography-high resolution mass spectrometry (LC-HRMS). The results show that the stability of GYM-A decreased with increasing temperature and pH values. The GYM-A was stable during storage at -20 °C regardless of pH, but it decreased rapidly (81.8% ± 9.3%) at 20 °C in pH 7 solution after 8 months. Moreover, the concentrations of GYM-A did not significantly change at all temperatures in solutions with pH 3 (p > 0.05). It is recommended that GYM-A should be stored at low temperature (≤-20 °C) and pH (≤3) conditions for long-term storage in aqueous methanolic media. In addition, two conversion products of GYM-A, tentatively named as GYM-K (m/z 540) and GYM-L (m/z 524), were identified in the samples stored at high levels of pH and temperature. Based on the LC-HRMS data, the hypothetical chemical structures of both converting derivatives were proposed. A useful strategy for long-term storage of GYM-A CRM in aqueous methanolic media was suggested and two hypothesized conversion products of GYM-A were discovered in this study.
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Alzheimer’s Disease and Toxins Produced by Marine Dinoflagellates: An Issue to Explore. Mar Drugs 2022; 20:md20040253. [PMID: 35447926 PMCID: PMC9029327 DOI: 10.3390/md20040253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/21/2022] [Accepted: 03/30/2022] [Indexed: 12/10/2022] Open
Abstract
This paper examined the toxins naturally produced by marine dinoflagellates and their effects on increases in β-amyloid plaques along with tau protein hyperphosphorylation, both major drivers of Alzheimer’s disease (AD). This approach is in line with the demand for certain natural compounds, namely those produced by marine invertebrates that have the potential to be used in the treatment of AD. Current advances in AD treatment are discussed as well as the main factors that potentially affect the puzzling global AD pattern. This study focused on yessotoxins (YTXs), gymnodimine (GYM), spirolides (SPXs), and gambierol, all toxins that have been shown to reduce β-amyloid plaques and tau hyperphosphorylation, thus preventing the neuronal or synaptic dysfunction that ultimately causes the cell death associated with AD (or other neurodegenerative diseases). Another group of toxins described, okadaic acid (OA) and its derivatives, inhibit protein phosphatase activity, which facilitates the presence of phosphorylated tau proteins. A few studies have used OA to trigger AD in zebrafish, providing an opportunity to test in vivo the effectiveness of new drugs in treating or attenuating AD. Constraints on the production of marine toxins for use in these tests have been considered. Different lines of research are anticipated regarding the action of the two groups of toxins.
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Zhang X, Gao Y, Deng B, Hu B, Zhao L, Guo H, Yang C, Ma Z, Sun M, Jiao B, Wang L. Selection, Characterization, and Optimization of DNA Aptamers against Challenging Marine Biotoxin Gymnodimine-A for Biosensing Application. Toxins (Basel) 2022; 14:195. [PMID: 35324692 PMCID: PMC8949142 DOI: 10.3390/toxins14030195] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 02/28/2022] [Accepted: 03/02/2022] [Indexed: 11/17/2022] Open
Abstract
Gymnodimines (GYMs), belonging to cyclic imines (CIs), are characterized as fast-acting toxins, and may pose potential risks to human health and the aquaculture industry through the contamination of sea food. The existing detection methods of GYMs have certain defects in practice, such as ethical problems or the requirement of complicated equipment. As novel molecular recognition elements, aptamers have been applied in many areas, including the detection of marine biotoxins. However, GYMs are liposoluble molecules with low molecular weight and limited numbers of chemical groups, which are considered as "challenging" targets for aptamers selection. In this study, Capture-SELEX was used as the main strategy in screening aptamers targeting gymnodimine-A (GYM-A), and an aptamer named G48nop, with the highest KD value of 95.30 nM, was successfully obtained by screening and optimization. G48nop showed high specificity towards GYM-A. Based on this, a novel aptasensor based on biolayer interferometry (BLI) technology was established in detecting GYM-A. This aptasensor showed a detection range from 55 to 1400 nM (linear range from 55 to 875 nM) and a limit of detection (LOD) of 6.21 nM. Spiking experiments in real samples indicated the recovery rate of this aptasensor, ranging from 96.65% to 109.67%. This is the first study to report an aptamer with high affinity and specificity for the challenging marine biotoxin GYM-A, and the new established aptasensor may be used as a reliable and efficient tool for the detection and monitoring of GYMs in the future.
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Affiliation(s)
- Xiaojuan Zhang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Navy Medical University, Shanghai 200433, China; (X.Z.); (Y.G.); (B.D.); (L.Z.); (H.G.); (C.Y.); (Z.M.); (M.S.)
- College of Medicine, Shaoxing University, 900th Chengnan Avenue, Shaoxing 312000, China
| | - Yun Gao
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Navy Medical University, Shanghai 200433, China; (X.Z.); (Y.G.); (B.D.); (L.Z.); (H.G.); (C.Y.); (Z.M.); (M.S.)
| | - Bowen Deng
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Navy Medical University, Shanghai 200433, China; (X.Z.); (Y.G.); (B.D.); (L.Z.); (H.G.); (C.Y.); (Z.M.); (M.S.)
| | - Bo Hu
- Department of Marine Biomedicine and Polar Medicine, Naval Medical Center of PLA, Navy Medical University, Shanghai 200433, China;
| | - Luming Zhao
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Navy Medical University, Shanghai 200433, China; (X.Z.); (Y.G.); (B.D.); (L.Z.); (H.G.); (C.Y.); (Z.M.); (M.S.)
| | - Han Guo
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Navy Medical University, Shanghai 200433, China; (X.Z.); (Y.G.); (B.D.); (L.Z.); (H.G.); (C.Y.); (Z.M.); (M.S.)
| | - Chengfang Yang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Navy Medical University, Shanghai 200433, China; (X.Z.); (Y.G.); (B.D.); (L.Z.); (H.G.); (C.Y.); (Z.M.); (M.S.)
| | - Zhenxia Ma
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Navy Medical University, Shanghai 200433, China; (X.Z.); (Y.G.); (B.D.); (L.Z.); (H.G.); (C.Y.); (Z.M.); (M.S.)
| | - Mingjuan Sun
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Navy Medical University, Shanghai 200433, China; (X.Z.); (Y.G.); (B.D.); (L.Z.); (H.G.); (C.Y.); (Z.M.); (M.S.)
| | - Binghua Jiao
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Navy Medical University, Shanghai 200433, China; (X.Z.); (Y.G.); (B.D.); (L.Z.); (H.G.); (C.Y.); (Z.M.); (M.S.)
| | - Lianghua Wang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Navy Medical University, Shanghai 200433, China; (X.Z.); (Y.G.); (B.D.); (L.Z.); (H.G.); (C.Y.); (Z.M.); (M.S.)
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Long M, Krock B, Castrec J, Tillmann U. Unknown Extracellular and Bioactive Metabolites of the Genus Alexandrium: A Review of Overlooked Toxins. Toxins (Basel) 2021; 13:905. [PMID: 34941742 PMCID: PMC8703713 DOI: 10.3390/toxins13120905] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/08/2021] [Accepted: 12/14/2021] [Indexed: 12/04/2022] Open
Abstract
Various species of Alexandrium can produce a number of bioactive compounds, e.g., paralytic shellfish toxins (PSTs), spirolides, gymnodimines, goniodomins, and also uncharacterised bioactive extracellular compounds (BECs). The latter metabolites are released into the environment and affect a large range of organisms (from protists to fishes and mammalian cell lines). These compounds mediate allelochemical interactions, have anti-grazing and anti-parasitic activities, and have a potentially strong structuring role for the dynamic of Alexandrium blooms. In many studies evaluating the effects of Alexandrium on marine organisms, only the classical toxins were reported and the involvement of BECs was not considered. A lack of information on the presence/absence of BECs in experimental strains is likely the cause of contrasting results in the literature that render impossible a distinction between PSTs and BECs effects. We review the knowledge on Alexandrium BEC, (i.e., producing species, target cells, physiological effects, detection methods and molecular candidates). Overall, we highlight the need to identify the nature of Alexandrium BECs and urge further research on the chemical interactions according to their ecological importance in the planktonic chemical warfare and due to their potential collateral damage to a wide range of organisms.
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Affiliation(s)
- Marc Long
- IFREMER, Centre de Brest, DYNECO Pelagos, 29280 Plouzané, France;
| | - Bernd Krock
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany;
| | - Justine Castrec
- University Brest, CNRS, IRD, Ifremer, LEMAR, 29280 Plouzané, France;
- Station de Recherches Sous-Marines et Océanographiques (STARESO), Punta Revellata, BP33, 20260 Calvi, France
| | - Urban Tillmann
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany;
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Ho TNT, Lee HS, Swaminathan S, Goodwin L, Rai N, Ushay B, Lewis RJ, Rosengren KJ, Conibear AC. Posttranslational modifications of α-conotoxins: sulfotyrosine and C-terminal amidation stabilise structures and increase acetylcholine receptor binding. RSC Med Chem 2021; 12:1574-1584. [PMID: 34671739 PMCID: PMC8459321 DOI: 10.1039/d1md00182e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 07/21/2021] [Indexed: 11/21/2022] Open
Abstract
Conotoxins are peptides found in the venoms of marine cone snails. They are typically highly structured and stable and have potent activities at nicotinic acetylcholine receptors, which make them valuable research tools and promising lead molecules for drug development. Many conotoxins are also highly modified with posttranslational modifications such as proline hydroxylation, glutamic acid gamma-carboxylation, tyrosine sulfation and C-terminal amidation, amongst others. The role of these posttranslational modifications is poorly understood, and it is unclear whether the modifications interact directly with the binding site, alter conotoxin structure, or both. Here we synthesised a set of twelve conotoxin variants bearing posttranslational modifications in the form of native sulfotyrosine and C-terminal amidation and show that these two modifications in combination increase their activity at nicotinic acetylcholine receptors and binding to soluble acetylcholine binding proteins, respectively. We then rationalise how these functional differences between variants might arise from stabilization of the three-dimensional structures and interactions with the binding sites, using high-resolution nuclear magnetic resonance data. This study demonstrates that posttranslational modifications can modulate interactions between a ligand and receptor by a combination of structural and binding alterations. A deeper mechanistic understanding of the role of posttranslational modifications in structure-activity relationships is essential for understanding receptor biology and could help to guide structure-based drug design.
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Affiliation(s)
- Thao N T Ho
- Institute for Molecular Bioscience, The University of Queensland St Lucia 4072 Brisbane Australia
| | - Han Siean Lee
- School of Biomedical Sciences, The University of Queensland St Lucia 4072 Brisbane Australia +61 7 3365 1738
| | - Shilpa Swaminathan
- School of Biomedical Sciences, The University of Queensland St Lucia 4072 Brisbane Australia +61 7 3365 1738
| | - Lewis Goodwin
- School of Biomedical Sciences, The University of Queensland St Lucia 4072 Brisbane Australia +61 7 3365 1738
| | - Nishant Rai
- School of Biomedical Sciences, The University of Queensland St Lucia 4072 Brisbane Australia +61 7 3365 1738
| | - Brianna Ushay
- School of Biomedical Sciences, The University of Queensland St Lucia 4072 Brisbane Australia +61 7 3365 1738
| | - Richard J Lewis
- Institute for Molecular Bioscience, The University of Queensland St Lucia 4072 Brisbane Australia
| | - K Johan Rosengren
- School of Biomedical Sciences, The University of Queensland St Lucia 4072 Brisbane Australia +61 7 3365 1738
| | - Anne C Conibear
- School of Biomedical Sciences, The University of Queensland St Lucia 4072 Brisbane Australia +61 7 3365 1738
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Lamas JP, Arévalo F, Moroño Á, Correa J, Rossignoli AE, Blanco J. Gymnodimine A in mollusks from the north Atlantic Coast of Spain: Prevalence, concentration, and relationship with spirolides. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 279:116919. [PMID: 33744630 DOI: 10.1016/j.envpol.2021.116919] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/28/2021] [Accepted: 03/06/2021] [Indexed: 06/12/2023]
Abstract
Gymnodimine A has been found in mollusks obtained along the whole northern coast of Spain from April 2017 to December 2019. This is the first time that this toxin is detected in mollusks from the Atlantic coast of Europe. The prevalence of the toxin was, in general, low, being detected on average in approximately 6% of the obtained samples (122 out of 1900). The concentrations recorded were also, in general, low, with a median of 1.3 μg kg-1, and a maximum value of 23.93 μg kg-1. The maxima of prevalence and concentration were not geographically coincident, taking place the first at the easternmost part of the sampled area and the second at the westernmost part. In most cases (>94%), gymnodimine A and 13-desmethyl spirolide C were concurrently detected, suggesting that Alexandrium ostenfeldii could be the responsible producer species. The existence of cases in which gymnodimine A was detected alone suggests also that a Karenia species could also be involved. The geographical heterogeneity of the distribution suggests that blooms of the producer species are mostly local. Not all bivalves are equally affected, clams being less affected than mussels, oysters, and razor clams. Due to their relatively low toxicity, and their low prevalence and concentration, it seems that these toxins do not pose an important risk for the mollusk consumers in the area.
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Affiliation(s)
- J Pablo Lamas
- Intecmar (Instituto Tecnolóxico para o Control Do Medio Mariño de Galicia), Peirao de Vilaxoán S/n, Vilagarcía de Arousa, 36611, Pontevedra, Spain
| | - Fabiola Arévalo
- Intecmar (Instituto Tecnolóxico para o Control Do Medio Mariño de Galicia), Peirao de Vilaxoán S/n, Vilagarcía de Arousa, 36611, Pontevedra, Spain.
| | - Ángeles Moroño
- Intecmar (Instituto Tecnolóxico para o Control Do Medio Mariño de Galicia), Peirao de Vilaxoán S/n, Vilagarcía de Arousa, 36611, Pontevedra, Spain.
| | - Jorge Correa
- Intecmar (Instituto Tecnolóxico para o Control Do Medio Mariño de Galicia), Peirao de Vilaxoán S/n, Vilagarcía de Arousa, 36611, Pontevedra, Spain.
| | - Araceli E Rossignoli
- Centro de Investigacións Mariñas (CIMA), Pedras de Corón S/n, 36620, Vilanova de Arousa, Spain.
| | - Juan Blanco
- Centro de Investigacións Mariñas (CIMA), Pedras de Corón S/n, 36620, Vilanova de Arousa, Spain.
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12
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Silva M, Rodríguez I, Barreiro A, Kaufmann M, Neto AI, Hassouani M, Sabour B, Alfonso A, Botana LM, Vasconcelos V. Lipophilic toxins occurrence in non-traditional invertebrate vectors from North Atlantic Waters (Azores, Madeira, and Morocco): Update on geographical tendencies and new challenges for monitoring routines. MARINE POLLUTION BULLETIN 2020; 161:111725. [PMID: 33080436 DOI: 10.1016/j.marpolbul.2020.111725] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 06/15/2020] [Accepted: 09/26/2020] [Indexed: 06/11/2023]
Abstract
In the last decades, due to monitoring programs and strict legislation poisoning incidents occurrence provoked by ingestion of naturally contaminated marine organisms has decreased. However, climate change and anthropogenic interference contributed to the expansion and establishment of toxic alien species to more temperate ecosystems. In this work, the coasts of Madeira, São Miguel islands and the northwestern Moroccan coast were surveyed for four groups of lipophilic toxins (yessotoxins, azaspiracids, pectenotoxins, and spirolides), searching for new vectors and geographical tendencies. Twenty-four species benthic organisms were screened using UHPLC-MS/MS technique. We report 19 new vectors for these toxins, six of them with commercial interest (P. aspera, P. ordinaria, C. lampas, P. pollicipes, H. tuberculata and P. lividus). Regarding toxin uptake a south-north gradient was detected. This study contributes to the update of monitoring routines and legislation policies, comprising a wider range of vectors, to better serve consumers and ecosystems preservation.
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Affiliation(s)
- Marisa Silva
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4619-007, Portugal; Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, 4450-208 S/N Matosinhos, Portugal.
| | - Inés Rodríguez
- Laboratorio CIFGA S.A., Avda. Benigno Rivera no. 56, 27003 Lugo, Spain; Department of Pharmacology, Faculty of Veterinary, University of Santiago of Compostela, 27002 Lugo, Spain.
| | - Aldo Barreiro
- Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, 4450-208 S/N Matosinhos, Portugal
| | - Manfred Kaufmann
- Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, 4450-208 S/N Matosinhos, Portugal; University of Madeira, Faculty of Life Sciences, Marine Biology Station of Funchal, 9000-107 Funchal, Portugal; Center of Interdisciplinary Marine and Environmental Research of Madeira-CIIMAR-Madeira, Edif. Madeira Tecnopolo, Caminho da Penteada, 9020-105 Funchal, Portugal.
| | - Ana Isabel Neto
- Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, 4450-208 S/N Matosinhos, Portugal; cE3c/GBA-Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group, Department of Biology, Faculty of Sciences and Technology, University of Azores, 9501-801 Ponta Delgada, São Miguel, Azores, Portugal.
| | - Meryem Hassouani
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4619-007, Portugal; Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, 4450-208 S/N Matosinhos, Portugal
| | - Brahim Sabour
- Phycology Research Unit-Biotechnology, Ecosystems Ecology and Valorization Laboratory, Faculty of Sciences El Jadida, University Chouaib Doukkali, BP20 El Jadida, Morocco.
| | - Amparo Alfonso
- Department of Pharmacology, Faculty of Veterinary, University of Santiago of Compostela, 27002 Lugo, Spain.
| | - Luis M Botana
- Department of Pharmacology, Faculty of Veterinary, University of Santiago of Compostela, 27002 Lugo, Spain.
| | - Vitor Vasconcelos
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4619-007, Portugal; Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, 4450-208 S/N Matosinhos, Portugal.
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13
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Nieva JA, Krock B, Tillmann U, Tebben J, Zurhelle C, Bickmeyer U. Gymnodimine A and 13-desMethyl Spirolide C Alter Intracellular Calcium Levels via Acetylcholine Receptors. Toxins (Basel) 2020; 12:toxins12120751. [PMID: 33261221 PMCID: PMC7760841 DOI: 10.3390/toxins12120751] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 11/23/2020] [Accepted: 11/26/2020] [Indexed: 11/18/2022] Open
Abstract
Gymnodimines and spirolides are cyclic imine phycotoxins and known antagonists of nicotinic acetylcholine receptors (nAChRs). We investigated the effect of gymnodimine A (GYM A) and 13-desmethyl spirolide C (SPX 1) from Alexandrium ostenfeldii on rat pheochromocytoma (PC12) cells by monitoring intracellular calcium levels ([Ca]i). Using whole cells, the presence of 0.5 µM of GYM A or SPX 1 induced an increase in [Ca]i mediated by acetylcholine receptors (AChRs) and inhibited further activation of AChRs by acetylcholine (ACh). To differentiate the effects of GYM A or SPX 1, the toxins were applied to cells with pharmacologically isolated nAChRs and muscarinic AChRs (mAChRs) as mediated by the addition of atropine and tubocurarine, respectively. GYM A and SPX 1 activated nAChRs and inhibited the further activation of nAChRs by ACh, indicating that both toxins mimicked the activity of ACh. Regarding mAChRs, a differential response was observed between the two toxins. Only GYM A activated mAChRs, resulting in elevated [Ca]i, but both toxins prevented a subsequent activation by ACh. The absence of the triketal ring system in GYM A may provide the basis for a selective activation of mAChRs. GYM A and SPX 1 induced no changes in [Ca]i when nAChRs and mAChRs were inhibited simultaneously, indicating that both toxins target AChRs.
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14
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Ho TNT, Abraham N, Lewis RJ. Structure-Function of Neuronal Nicotinic Acetylcholine Receptor Inhibitors Derived From Natural Toxins. Front Neurosci 2020; 14:609005. [PMID: 33324158 PMCID: PMC7723979 DOI: 10.3389/fnins.2020.609005] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 10/30/2020] [Indexed: 12/19/2022] Open
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are prototypical cation-selective, ligand-gated ion channels that mediate fast neurotransmission in the central and peripheral nervous systems. nAChRs are involved in a range of physiological and pathological functions and hence are important therapeutic targets. Their subunit homology and diverse pentameric assembly contribute to their challenging pharmacology and limit their drug development potential. Toxins produced by an extensive range of algae, plants and animals target nAChRs, with many proving pivotal in elucidating receptor pharmacology and biochemistry, as well as providing templates for structure-based drug design. The crystal structures of these toxins with diverse chemical profiles in complex with acetylcholine binding protein (AChBP), a soluble homolog of the extracellular ligand-binding domain of the nAChRs and more recently the extracellular domain of human α9 nAChRs, have been reported. These studies have shed light on the diverse molecular mechanisms of ligand-binding at neuronal nAChR subtypes and uncovered critical insights useful for rational drug design. This review provides a comprehensive overview and perspectives obtained from structure and function studies of diverse plant and animal toxins and their associated inhibitory mechanisms at neuronal nAChRs.
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Affiliation(s)
| | | | - Richard J. Lewis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
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15
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Camacho-Hernandez GA, Taylor P. Lessons from nature: Structural studies and drug design driven by a homologous surrogate from invertebrates, AChBP. Neuropharmacology 2020; 179:108108. [DOI: 10.1016/j.neuropharm.2020.108108] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/08/2020] [Accepted: 04/12/2020] [Indexed: 02/07/2023]
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16
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Zurhelle C, Harder T, Tillmann U, Tebben J. In Silico Modeling of Spirolides and Gymnodimines: Determination of S Configuration at Butenolide Ring Carbon C-4. Toxins (Basel) 2020; 12:toxins12110685. [PMID: 33138275 PMCID: PMC7692061 DOI: 10.3390/toxins12110685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 11/16/2022] Open
Abstract
Only few naturally occurring cyclic imines have been fully structurally elucidated or synthesized to date. The configuration at the C-4 carbon plays a pivotal role in the neurotoxicity of many of these metabolites, for example, gymnodomines (GYMs) and spirolides (SPXs). However, the stereochemistry at this position is not accessible by nuclear Overhauser effect-nuclear magnetic resonance spectroscopy (NOE-NMR) due to unconstrained rotation of the single carbon bond between C-4 and C-5. Consequently, the relative configuration of GYMs and SPXs at C-4 and its role in protein binding remains elusive. Here, we determined the stereochemical configuration at carbon C-4 in the butenolide ring of spirolide- and gymnodimine-phycotoxins by comparison of measured 13C NMR shifts with values obtained in silico using force field, semiempirical and density functional theory methods. This comparison demonstrated that modeled data support S configuration at C-4 for all studied SPXs and GYMs, suggesting a biosynthetically conserved relative configuration at carbon C-4 among these toxins.
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Affiliation(s)
- Christian Zurhelle
- Department of Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany; (C.Z.); (T.H.); (U.T.)
| | - Tilmann Harder
- Department of Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany; (C.Z.); (T.H.); (U.T.)
- Faculty of Biology and Chemistry, University of Bremen, Leobener Straße 6, 28359 Bremen, Germany
| | - Urban Tillmann
- Department of Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany; (C.Z.); (T.H.); (U.T.)
| | - Jan Tebben
- Department of Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany; (C.Z.); (T.H.); (U.T.)
- Correspondence: ; Tel.: +49-471-4831-1086
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17
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Aráoz R, Barnes P, Séchet V, Delepierre M, Zinn-Justin S, Molgó J, Zakarian A, Hess P, Servent D. Cyclic imine toxins survey in coastal european shellfish samples: Bioaccumulation and mode of action of 28-O-palmitoyl ester of pinnatoxin-G. first report of portimine-A bioaccumulation. HARMFUL ALGAE 2020; 98:101887. [PMID: 33129465 PMCID: PMC7657664 DOI: 10.1016/j.hal.2020.101887] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/11/2020] [Accepted: 07/24/2020] [Indexed: 05/12/2023]
Abstract
Cyclic imine toxins exhibit fast acting neurotoxicity and lethality by respiratory arrest in mice explained by their potent antagonistic activity against muscular nicotinic acetylcholine receptors. We performed a survey of gymnodimine-A, 13-desmethyl spirolide-C, 13,19-didesmethyl spirolide-C, 20-methyl spirolide-G, pinnatoxin-A, pinnatoxin-G, portimine-A and 28-O-palmitoyl ester of pinnatoxin-G in 36 shellfish samples collected in coastal areas of 8 European countries using a microplate receptor binding assay and UPLC-MS/MS for toxin identification and quantification. The major toxins found in these samples were pinnatoxin-G, 20-methyl spirolide-G, 13-desmethyl spirolide-C, gymnodimine-A and portimine-A. Traces of 13,19-didesmethyl spirolide-C, pinnatoxin-A and 28-O-palmitoyl ester of pinnatoxin-G were also detected. The rapid death of mice was correlated with higher pinnatoxin-G concentrations in mussel digestive gland extracts injected intraperitoneally. Our survey included nontoxic control samples that were found to contain moderate to trace amounts of several cyclic imine toxins. Shellfish may bioaccumulate not only cyclic imine toxins but also a large number of acyl derivatives as a product of metabolic transformation of these neurotoxins. This is the first report in which portimine-A and 28-O-palmitoyl ester of pinnatoxin-G were detected in shellfish extracts from digestive glands of mussels collected in Ingril lagoon. The bioaccumulation of portimine-A is particularly of concern because it is cytotoxic and is able to induce apotosis. The mode of action of 28-O-palmitoyl ester of pinnatoxin-G was studied by receptor binding-assay and by two-electrode voltage clamp electrophysiology. The antagonistic behavior of the acylated pinnatoxin-G towards nicotinic acetylcholine receptor of muscle type is shown here for the first time. Since cyclic imine toxins are not regulated further monitoring of these emerging toxins is needed to improve evidence gathering of their occurrence in shellfish commercialized for human consumption in Europe given their potent antagonism against muscle and neuronal nicotinic acetylcholine receptors.
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Affiliation(s)
- Rómulo Aráoz
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, 91191 Gif-sur-Yvette, France; CNRS, ERL9004, 91191, Gif-sur-Yvette, France.
| | - Paul Barnes
- Agri-food and Biosciences Institute, Veterinary Science Division, Stoney Road, Belfast BT4 3SD, Northern Ireland, United Kingdom
| | - Véronique Séchet
- Ifremer, Centre Atlantique, Laboratoire Phycotoxines, 44311 Nantes Cedex, France
| | - Muriel Delepierre
- Institut Pasteur, Department of Structural Biology and Chemistry CNRS, UMR3528, Paris France
| | - Sophie Zinn-Justin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, Gif- sur -Yvette Cedex, France
| | - Jordi Molgó
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, 91191 Gif-sur-Yvette, France; CNRS, ERL9004, 91191, Gif-sur-Yvette, France
| | - Armen Zakarian
- University California Santa Barbara, Dept Chem & Biochem, Santa Barbara, CA 93106 United States
| | - Philipp Hess
- Ifremer, Centre Atlantique, Laboratoire Phycotoxines, 44311 Nantes Cedex, France
| | - Denis Servent
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SIMoS, 91191 Gif-sur-Yvette, France; CNRS, ERL9004, 91191, Gif-sur-Yvette, France
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18
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Ishihara J. Chiral Lewis Acid-template Diels-Alder Reaction and the Application of Natural Product Synthesis. J SYN ORG CHEM JPN 2020. [DOI: 10.5059/yukigoseikyokaishi.78.204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Jun Ishihara
- Graduate School of Biomedical Sciences, Nagasaki University
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19
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Minamino K, Murata M, Tsuchikawa H. Synthesis of 7,6-Spirocyclic Imine with Butenolide Ring Provides Evidence for the Relative Configuration of Marine Toxin 13-desMe Spirolide C. Org Lett 2019; 21:8970-8975. [DOI: 10.1021/acs.orglett.9b03373] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Kou Minamino
- Department of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Michio Murata
- Department of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Hiroshi Tsuchikawa
- Department of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
- Research Promotion Institute, Oita University, 1-1 Idaigaoka, Hasama, Yufu, Oita 879-5593, Japan
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20
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Hermawan I, Higa M, Hutabarat PUB, Fujiwara T, Akiyama K, Kanamoto A, Haruyama T, Kobayashi N, Higashi M, Suda S, Tanaka J. Kabirimine, a New Cyclic Imine from an Okinawan Dinoflagellate. Mar Drugs 2019; 17:E353. [PMID: 31200525 PMCID: PMC6627061 DOI: 10.3390/md17060353] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/10/2019] [Accepted: 06/11/2019] [Indexed: 01/30/2023] Open
Abstract
On our quest for new bioactive molecules from marine sources, two cyclic imines (1, 2) were isolated from a dinoflagellate extract, inhibiting the growth of the respiratory syncytial virus (RSV). Compound 1 was identified as a known molecule portimine, while 2 was elucidated to be a new cyclic imine, named kabirimine. The absolute stereochemistry of 1 was determined by crystallographic work and chiral derivatization, whereas the structure of 2 was elucidated by means of spectroscopic analysis and computational study on all the possible isomers. Compound 1 showed potent cytotoxicity (CC50 < 0.097 µM) against HEp2 cells, while 2 exhibited moderate antiviral activity against RSV with IC50 = 4.20 µM (95% CI 3.31-5.33).
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Affiliation(s)
- Idam Hermawan
- Graduate School of Engineering and Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan.
| | - Mikako Higa
- Graduate School of Engineering and Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan.
| | - Philipus Uli Basa Hutabarat
- Graduate School of Engineering and Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan.
| | - Takeshi Fujiwara
- OP Bio Factory Co., Ltd., Okinawa Life Science Center 107, 5-8 Suzaki, Uruma, Okinawa 904-02234, Japan.
| | - Kiyotaka Akiyama
- OP Bio Factory Co., Ltd., Okinawa Life Science Center 107, 5-8 Suzaki, Uruma, Okinawa 904-02234, Japan.
| | - Akihiko Kanamoto
- OP Bio Factory Co., Ltd., Okinawa Life Science Center 107, 5-8 Suzaki, Uruma, Okinawa 904-02234, Japan.
| | - Takahiro Haruyama
- Central Research Center, AVSS Corporation, Nagasaki 852-8137, Japan.
| | | | - Masahiro Higashi
- Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan.
| | - Shoichiro Suda
- Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan.
| | - Junichi Tanaka
- Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan.
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21
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Alarcan J, Dubreil E, Huguet A, Aráoz R, Brée F, Bouaita B, Hurtaud-Pessel D, Braeuning A, Hessel-Pras S, Lampen A, Le Hégarat L, Fessard V. Metabolism of the lipophilic phycotoxin 13-Desmethylspirolide C using human and rat in vitro liver models. Toxicol Lett 2019; 307:17-25. [PMID: 30825503 DOI: 10.1016/j.toxlet.2019.02.012] [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: 12/05/2018] [Revised: 02/14/2019] [Accepted: 02/23/2019] [Indexed: 10/27/2022]
Abstract
13-Desmethylspirolide C (13-SPX-C) is a phycotoxin produced by dinoflagellates which can accumulate in shellfish. 13-SPX-C induces neurotoxic effects in rodents through blockade of nicotinic acetylcholine receptors. As no human intoxication has been to date attributed to the consumption of 13-SPX-C-contaminated seafood, this toxin is not regulated according to the Codex Alimentarius. Nevertheless, shellfish consumers can be exposed to 13-SPX-C via shellfish consumption. In order to follow the fate of the toxin after ingestion and to verify whether metabolic detoxification could explain the lack of human intoxications, we assessed the metabolism of 13-SPX-C using several in vitro liver systems. First, both phase I and II reactions occurring with rat and human liver S9 fractions were screened. Our results indicated that 13-SPX-C was almost completely metabolized with both rat and human liver S9. Using a receptor binding assay towards nicotinic acetylcholine receptors we demonstrated that the resulting metabolites showed less affinity towards nicotinic acetylcholine receptors than 13-SPX-C. Finally, we showed that 13-SPX-C induced a pronounced increase of gene expression of the drug-metabolizing enzyme cytochrome P450 (CYP) CYP1A2. The role of this CYP in 13-SPX-C metabolism was clarified using an innovative in vitro tool, CYP1A2-Silensomes™. In summary, this study highlights that liver first-pass metabolism can contribute to the detoxification of 13-SPX-C.
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Affiliation(s)
- Jimmy Alarcan
- Toxicology of Contaminants Unit, French Agency for Food, Environmental and Occupational Health & Safety, ANSES, Fougères, 35306, France; BfR, German Federal Institute for Risk Assessment, Department of Food Safety, Max Dohrn Strasse 8-10, 10589, Berlin, Germany.
| | - Estelle Dubreil
- Analysis of Residues and Contaminants Unit, French Agency for Food, Environmental and Occupational Health & Safety, ANSES, Fougères, 35306, France.
| | - Antoine Huguet
- Toxicology of Contaminants Unit, French Agency for Food, Environmental and Occupational Health & Safety, ANSES, Fougères, 35306, France.
| | - Romulo Aráoz
- CNRS, Institut de Neurosciences (Neuro-PSI), UMR9197, 91191, Gif sur Yvette, France; CEA/DRF/JOLIOT/SIMOPRO, Université Paris-Saclay, 91191, Gif sur Yvette, France.
| | - Françoise Brée
- Eurosafe, Parc d'Affaires La Bretêche, 35760, Saint Grégoire, France.
| | - Belkacem Bouaita
- Biopredic International, Parc d'Affaires La Bretêche, 35760, Saint Grégoire, France.
| | - Dominique Hurtaud-Pessel
- Analysis of Residues and Contaminants Unit, French Agency for Food, Environmental and Occupational Health & Safety, ANSES, Fougères, 35306, France.
| | - Albert Braeuning
- BfR, German Federal Institute for Risk Assessment, Department of Food Safety, Max Dohrn Strasse 8-10, 10589, Berlin, Germany.
| | - Stefanie Hessel-Pras
- BfR, German Federal Institute for Risk Assessment, Department of Food Safety, Max Dohrn Strasse 8-10, 10589, Berlin, Germany.
| | - Alfonso Lampen
- BfR, German Federal Institute for Risk Assessment, Department of Food Safety, Max Dohrn Strasse 8-10, 10589, Berlin, Germany.
| | - Ludovic Le Hégarat
- Toxicology of Contaminants Unit, French Agency for Food, Environmental and Occupational Health & Safety, ANSES, Fougères, 35306, France.
| | - Valérie Fessard
- Toxicology of Contaminants Unit, French Agency for Food, Environmental and Occupational Health & Safety, ANSES, Fougères, 35306, France.
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22
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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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23
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Gao G, Fu Q, Beardall J, Wu M, Xu J. Combination of ocean acidification and warming enhances the competitive advantage of Skeletonema costatum over a green tide alga, Ulva linza. HARMFUL ALGAE 2019; 85:101698. [PMID: 31810528 DOI: 10.1016/j.hal.2019.101698] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 06/10/2023]
Abstract
Red tide and green tide are two common algal blooms that frequently occur in many areas in the global oceans. The algae causing red tide and green tide often interact with each other in costal ecosystems. However, little is known on how future CO2-induced ocean acidification combined with temperature variation would affect the interaction of red and green tides. In this study, we cultured the red tide alga Skeletonema costatum and the green tide alga Ulva linza under ambient (400 ppm) and future CO2 (1000 ppm) levels and three temperatures (12, 18, 24 °C) in both monoculture and coculture systems. Coculture did not affect the growth rate of U. linza but significantly decreased it for S. costatum. Elevated CO2 relieved the inhibitory effect of U. linza on the growth of S. costatum, particularly for higher temperatures. At elevated CO2, higher temperature increased the growth rate of S. costatum but reduced it for U. linza. Coculture with U. linza reduced the net photosynthetic rate of S. costatum, which was relieved by elevated CO2. This pattern was also found in Chl a content, indicating that U. linza may inhibit growth of S. costatum via harming pigment synthesis and thus photosynthesis. In monoculture, higher temperature did not affect respiration rate of S. costatum but increased it in U. linza. Coculture did not affect respiration of U. linza but stimulated it for S. costatum, which was a signal of responding to biotic and/abiotic stress. The increased growth of S. costatum at higher temperature and decreased inhibition of U. linza on S. costatum at elevated CO2 suggest that red tides may have more advantages over green tides in future warmer and CO2-enriched oceans.
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Affiliation(s)
- Guang Gao
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, China
| | - Qianqian Fu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Min Wu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Juntian Xu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang, 222005, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Lianyungang 222005, China; Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China.
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24
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Freeman JL, Brimble MA, Furkert DP. Convenient access to 5-membered cyclic iminium ions: evidence for a stepwise [4 + 2] cycloaddition mechanism. Org Biomol Chem 2019; 17:2705-2714. [PMID: 30768089 DOI: 10.1039/c9ob00262f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In situ generation and reaction of novel 5-membered N-tosyl cyclic α,β-unsaturated iminium ions from readily prepared stable precursors is demonstrated. Formal iminium Diels-Alder cycloaddition proceeded in good yield via a stepwise rather than concerted cycloaddition process, confirmed through the isolation of a Mukaiyama-Michael type intermediate. Relative stereochemistry was determined upon subsequent intramolecular cyclisation under Lewis acid catalysis to afford formal endo 5,6-spirobicyclic adducts, as confirmed by crystallography. Further synthetic elaboration towards complex molecular scaffolds based on the dinoflagellate metabolite portimine, a potent apoptosis inducer, were also developed.
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Affiliation(s)
- Jared L Freeman
- School of Chemical Sciences, The University of Auckland, Symonds Street, Auckland 1010, New Zealand.
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25
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Guthertz A, Lusseau J, Desvergnes V, Massip S, Landais Y. An Approach towards the Synthesis of the Spiroimine Fragment of 13-Desmethylspirolide C and Gymnodimine A. Chemistry 2019; 25:1553-1560. [DOI: 10.1002/chem.201804972] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Alexandre Guthertz
- Institute of Molecular Sciences (ISM), UMR-CNRS 5255; University of Bordeaux; 351 Cours de la libération 33405 Talence cedex France
| | - Jonathan Lusseau
- Institute of Molecular Sciences (ISM), UMR-CNRS 5255; University of Bordeaux; 351 Cours de la libération 33405 Talence cedex France
| | - Valérie Desvergnes
- Institute of Molecular Sciences (ISM), UMR-CNRS 5255; University of Bordeaux; 351 Cours de la libération 33405 Talence cedex France
| | - Stéphane Massip
- European Institute of Chemistry and Biology (IECB); University of Bordeaux; 2 Rue Robert Escarpit 33600 Pessac France
| | - Yannick Landais
- Institute of Molecular Sciences (ISM), UMR-CNRS 5255; University of Bordeaux; 351 Cours de la libération 33405 Talence cedex France
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26
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Ishihara J, Usui F, Kurose T, Baba T, Kawaguchi Y, Watanabe Y, Hatakeyama S. Synthetic Studies on Spirolides A and B: Formation of the Upper Carbon Framework Based on a Lewis Acid Template-Catalyzed Diels-Alder Reaction. Chemistry 2018; 25:1543-1552. [DOI: 10.1002/chem.201804977] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Jun Ishihara
- Graduate School of Biomedical Sciences; Nagasaki University; 1-14, Bunkyo-machi Nagasaki 852-8521 Japan
| | - Fuma Usui
- Graduate School of Biomedical Sciences; Nagasaki University; 1-14, Bunkyo-machi Nagasaki 852-8521 Japan
| | - Tomohiro Kurose
- Graduate School of Biomedical Sciences; Nagasaki University; 1-14, Bunkyo-machi Nagasaki 852-8521 Japan
| | - Tomohiro Baba
- Graduate School of Biomedical Sciences; Nagasaki University; 1-14, Bunkyo-machi Nagasaki 852-8521 Japan
| | - Yasunori Kawaguchi
- Graduate School of Biomedical Sciences; Nagasaki University; 1-14, Bunkyo-machi Nagasaki 852-8521 Japan
| | - Yuki Watanabe
- Graduate School of Biomedical Sciences; Nagasaki University; 1-14, Bunkyo-machi Nagasaki 852-8521 Japan
| | - Susumi Hatakeyama
- Medical Innovation Center; Nagasaki University; 1-14, Bunkyo-machi Nagasaki 852-8521 Japan
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27
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Discovery, cocrystallization and biological evaluation of novel piperidine derivatives as high affinity Ls-AChBP ligands possessing α7 nAChR activities. Eur J Med Chem 2018; 160:37-48. [PMID: 30317024 DOI: 10.1016/j.ejmech.2018.09.073] [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: 05/28/2018] [Revised: 09/05/2018] [Accepted: 09/30/2018] [Indexed: 11/23/2022]
Abstract
A series of novel pyridine-substituted piperidine derivatives were discovered as low nanomolar Ls-AChBP ligands with α7 nAChR partial agonism or antagonism activities. A high-resolution antagonist-bound Ls-AChBP complex was successfully resolved with a classic Loop C opening phenomenon and unique sulfur-π interactions which deviated from our previous docking mode to a large extent. With the knowledge of the co-complex, 27 novel piperidine derivatives were designed and synthesized. The structure-activity relationships (SARs) of the aromatic and pyridine regions were well established and binding modes were illustrated with the help of molecular docking which indicated that interactions with Trp 143 and the "water bridge" are essential for the high binding affinities. Halogen bonding as well as the space around 5'- or 6'- position of the pyridine ring was also proposed to influence the binding conformation of the compounds. Notably, two enantiomers of compound 2 showed opposite functions toward α7 nAChR and compound (S)-2 showed sub-nanomolar affinity (Ki = 0.86 nM) on Ls-AChBP and partial agonism (pEC50 = 4.69 ± 0.11,Emax = 36.1%) on α7 nAChR with reasonable pharmacokinetics (PK) properties and fine ability of blood-brain-barrier (BBB) penetration. This study provided promising hits to develop candidates targeting nAChR-related CNS diseases.
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28
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Boente-Juncal A, Méndez AG, Vale C, Vieytes MR, Botana LM. In Vitro Effects of Chronic Spirolide Treatment on Human Neuronal Stem Cell Differentiation and Cholinergic System Development. ACS Chem Neurosci 2018. [PMID: 29518322 DOI: 10.1021/acschemneuro.8b00036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Spirolides (SPX) are marine toxins, produced by dinoflagellates that act as potent antagonists of nicotinic acetylcholine receptors. These compounds are not toxic for humans, and since there are no reports of human intoxications caused by this group of toxins they are not yet currently regulated in Europe. Currently 13-desmethyl spirolide C, 13,19-didesmethyl spirolide C, and 20-methyl spirolide G are commercially available as reference materials. Previous work in our laboratory has demonstrated that after 4 days of treatment of primary mice cortical neurons with 13-desmethyl spirolide C, the compound ameliorated the glutamate induced toxicity and increased acetylcholine levels and the expression of the acetylcholine synthesizing enzyme being useful both in vitro and in vivo to decrease the brain pathology associated with Alzheimer's disease. In this work, we aimed to extend the study of the neuronal effects of spirolides in human neuronal cells. To this end, human neuronal progenitor cells CTX0E16 were employed to evaluate the in vitro effect of spirolides on neuronal development. The results presented here indicate that long-term exposure (30 days) of human neuronal stem cells to SPX compounds, at concentrations up to 50 nM, ameliorated the MPP+-induced neurotoxicity and increased the expression of neuritic and dendritic markers, the levels of the choline acetyltransferase enzyme and the protein levels of the α7 subunit of nicotinic acetylcholine receptors. These effects are presumably due to the previously described interaction of these compounds with nicotinic receptors containing both α7 and α4 subunits. All together, these data emphasize the idea that SPX could be attractive lead molecules against neurodegenerative disorders.
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Affiliation(s)
- Andrea Boente-Juncal
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27001 Lugo, Spain
| | - Aida G. Méndez
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27001 Lugo, Spain
| | - Carmen Vale
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27001 Lugo, Spain
| | - Mercedes R. Vieytes
- Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27001 Lugo, Spain
| | - Luis M. Botana
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27001 Lugo, Spain
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29
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Farabegoli F, Blanco L, Rodríguez LP, Vieites JM, Cabado AG. Phycotoxins in Marine Shellfish: Origin, Occurrence and Effects on Humans. Mar Drugs 2018; 16:E188. [PMID: 29844286 PMCID: PMC6025170 DOI: 10.3390/md16060188] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/18/2018] [Accepted: 05/25/2018] [Indexed: 02/07/2023] Open
Abstract
Massive phytoplankton proliferation, and the consequent release of toxic metabolites, can be responsible for seafood poisoning outbreaks: filter-feeding mollusks, such as shellfish, mussels, oysters or clams, can accumulate these toxins throughout the food chain and present a threat for consumers' health. Particular environmental and climatic conditions favor this natural phenomenon, called harmful algal blooms (HABs); the phytoplankton species mostly involved in these toxic events are dinoflagellates or diatoms belonging to the genera Alexandrium, Gymnodinium, Dinophysis, and Pseudo-nitzschia. Substantial economic losses ensue after HABs occurrence: the sectors mainly affected include commercial fisheries, tourism, recreational activities, and public health monitoring and management. A wide range of symptoms, from digestive to nervous, are associated to human intoxication by biotoxins, characterizing different and specific syndromes, called paralytic shellfish poisoning, amnesic shellfish poisoning, diarrhetic shellfish poisoning, and neurotoxic shellfish poisoning. This review provides a complete and updated survey of phycotoxins usually found in marine invertebrate organisms and their relevant properties, gathering information about the origin, the species where they were found, as well as their mechanism of action and main effects on humans.
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Affiliation(s)
- Federica Farabegoli
- Food Safety and Industrial Hygiene Division, ANFACO-CECOPESCA. 16, Crta. Colexio Universitario, 36310 Vigo (Pontevedra), Spain.
| | - Lucía Blanco
- Food Safety and Industrial Hygiene Division, ANFACO-CECOPESCA. 16, Crta. Colexio Universitario, 36310 Vigo (Pontevedra), Spain.
| | - Laura P Rodríguez
- Food Safety and Industrial Hygiene Division, ANFACO-CECOPESCA. 16, Crta. Colexio Universitario, 36310 Vigo (Pontevedra), Spain.
| | - Juan Manuel Vieites
- Food Safety and Industrial Hygiene Division, ANFACO-CECOPESCA. 16, Crta. Colexio Universitario, 36310 Vigo (Pontevedra), Spain.
| | - Ana García Cabado
- Food Safety and Industrial Hygiene Division, ANFACO-CECOPESCA. 16, Crta. Colexio Universitario, 36310 Vigo (Pontevedra), Spain.
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30
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Yasukawa Y, Tsuchikawa H, Todokoro Y, Murata M. Stereoselective Construction of Cisoidal Bisspiroacetal Frameworks through Magnesium Coordination of the Bilateral Acetal Oxygen Atoms. ASIAN J ORG CHEM 2018. [DOI: 10.1002/ajoc.201800074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yoshifumi Yasukawa
- Department of Chemistry, Graduate School of Science; Osaka University; 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
| | - Hiroshi Tsuchikawa
- Department of Chemistry, Graduate School of Science; Osaka University; 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
| | - Yasuto Todokoro
- Department of Chemistry, Graduate School of Science; Osaka University; 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
| | - Michio Murata
- Department of Chemistry, Graduate School of Science; Osaka University; 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
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31
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Prorocentrolide-A from Cultured Prorocentrum lima Dinoflagellates Collected in Japan Blocks Sub-Types of Nicotinic Acetylcholine Receptors. Toxins (Basel) 2018; 10:toxins10030097. [PMID: 29495549 PMCID: PMC5869385 DOI: 10.3390/toxins10030097] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 02/19/2018] [Accepted: 02/23/2018] [Indexed: 01/19/2023] Open
Abstract
Prorocentrolides are members of the cyclic imine phycotoxins family. Their chemical structure includes a 26-membered carbo-macrocycle and a 28-membered macrocyclic lactone arranged around a hexahydroisoquinoline that incorporates the characteristic cyclic imine group. Six prorocentrolides are already known. However, their mode of action remains undetermined. The aim of the present work was to explore whether prorocentrolide-A acts on nicotinic acetylcholine receptors (nAChRs), using competition-binding assays and electrophysiological techniques. Prorocentrolide-A displaced [125I]α-bungarotoxin binding to Torpedo membranes, expressing the muscle-type (α12β1γδ) nAChR, and in HEK-293 cells, expressing the chimeric chick neuronal α7-5HT3 nAChR. Functional studies revealed that prorocentrolide-A had no agonist action on nAChRs, but inhibited ACh-induced currents in Xenopus oocytes that had incorporated the muscle-type α12β1γδ nAChR to their membranes, or that expressed the human α7 nAChR, as revealed by voltage-clamp recordings. Molecular docking calculations showed the absence of the characteristic hydrogen bond between the iminium group of prorocentrolide-A and the backbone carbonyl group of Trp147 in the receptor, explaining its weaker affinity as compared to all other cyclic imine toxins. In conclusion, this is the first study to show that prorocentrolide-A acts on both muscle and neuronal nAChRs, but with higher affinity on the muscle-type nAChR.
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32
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Nemecz Á, Prevost MS, Menny A, Corringer PJ. Emerging Molecular Mechanisms of Signal Transduction in Pentameric Ligand-Gated Ion Channels. Neuron 2017; 90:452-70. [PMID: 27151638 DOI: 10.1016/j.neuron.2016.03.032] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 01/07/2016] [Accepted: 03/24/2016] [Indexed: 10/21/2022]
Abstract
Nicotinic acetylcholine, serotonin type 3, γ-amminobutyric acid type A, and glycine receptors are major players of human neuronal communication. They belong to the family of pentameric ligand-gated ion channels, sharing a highly conserved modular 3D structure. Recently, high-resolution structures of both open- and closed-pore conformations have been solved for a bacterial, an invertebrate, and a vertebrate receptor in this family. These data suggest that a common gating mechanism occurs, coupling neurotransmitter binding to pore opening, but they also pinpoint significant differences among subtypes. In this Review, we summarize the structural and functional data in light of these gating models and speculate about their mechanistic consequences on ion permeation, pathological mutations, as well as functional regulation by orthosteric and allosteric effectors.
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Affiliation(s)
- Ákos Nemecz
- Channel-Receptors Unit, Institut Pasteur, 75015 Paris, France; CNRS UMR 3571, 75015 Paris, France
| | - Marie S Prevost
- Institute of Structural and Molecular Biology, University College London and Birkbeck, Malet Street, London WC1E 7HX, UK
| | - Anaïs Menny
- Channel-Receptors Unit, Institut Pasteur, 75015 Paris, France; CNRS UMR 3571, 75015 Paris, France; Université Pierre et Marie Curie (UPMC), Cellule Pasteur, 75005 Paris, France
| | - Pierre-Jean Corringer
- Channel-Receptors Unit, Institut Pasteur, 75015 Paris, France; CNRS UMR 3571, 75015 Paris, France.
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33
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Ma Q, Tae HS, Wu G, Jiang T, Yu R. Exploring the Relationship between Nicotinic Acetylcholine Receptor Ligand Size, Efficiency, Efficacy, and C-Loop Opening. J Chem Inf Model 2017; 57:1947-1956. [PMID: 28718646 DOI: 10.1021/acs.jcim.7b00152] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels mediating fundamental physiological activities in the nervous system and have become important targets for drug design. For a long time, the acetylcholine binding protein (AChBP) has been used as a surrogate to study the nAChR structure-function. Taking advantage of more than 100 AChBP crystal structures in the Protein DataBank (PDB), we explored the relationship between the size, efficiency, and efficacy of nAChR ligands and the C-loop movement. We found that the size of the ligand is correlated with the opening of the C-loop, which can be used in selecting AChBP crystal structures with appropriate C-loop opening to be used for nAChR ligand docking. Ligand size and C-loop opening are reversely correlated with the ligand efficiency rather than the binding affinity. Ligand efficiency could be accurately predicted using simple computational docking, giving a correlation coefficients (R2) up to 0.73. The efficacy of nAChR ligands might be related to ligand size, C-loop opening, and ligand efficiency. Results from this study are useful for engineering the binding affinity and efficacy of nAChR ligands.
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Affiliation(s)
- Qianyun Ma
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China , Qingdao 266003, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology , Qingdao 266003, China
| | - Han-Shen Tae
- Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong , Wollongong, New South Wales 2522, Australia
| | - Guanzhao Wu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China , Qingdao 266003, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology , Qingdao 266003, China
| | - Tao Jiang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China , Qingdao 266003, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology , Qingdao 266003, China
| | - Rilei Yu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China , Qingdao 266003, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology , Qingdao 266003, China
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34
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Shmukler YB, Nikishin DA. Ladder-Shaped Ion Channel Ligands: Current State of Knowledge. Mar Drugs 2017; 15:E232. [PMID: 28726749 PMCID: PMC5532674 DOI: 10.3390/md15070232] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 07/07/2017] [Accepted: 07/14/2017] [Indexed: 12/20/2022] Open
Abstract
Ciguatoxins (CTX) and brevetoxins (BTX) are polycyclic ethereal compounds biosynthesized by the worldwide distributed planktonic and epibenthic dinoflagellates of Gambierdiscus and Karenia genera, correspondingly. Ciguatera, evoked by CTXs, is a type of ichthyosarcotoxism, which involves a variety of gastrointestinal and neurological symptoms, while BTXs cause so-called neurotoxic shellfish poisoning. Both types of toxins are reviewed together because of similar mechanisms of their action. These are the only molecules known to activate voltage-sensitive Na⁺-channels in mammals through a specific interaction with site 5 of its α-subunit and may compete for it, which results in an increase in neuronal excitability, neurotransmitter release and impairment of synaptic vesicle recycling. Most marine ciguatoxins potentiate Nav channels, but a considerable number of them, such as gambierol and maitotoxin, have been shown to affect another ion channel. Although the extrinsic function of these toxins is probably associated with the function of a feeding deterrent, it was suggested that their intrinsic function is coupled with the regulation of photosynthesis via light-harvesting complex II and thioredoxin. Antagonistic effects of BTXs and brevenal may provide evidence of their participation as positive and negative regulators of this mechanism.
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Affiliation(s)
- Yuri B Shmukler
- Group of Embryophysiology, N.K. Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26, Vavilov st, 119334 Moscow, Russia.
| | - Denis A Nikishin
- Group of Embryophysiology, N.K. Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26, Vavilov st, 119334 Moscow, Russia.
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Tsuchikawa H, Minamino K, Hayashi S, Murata M. Efficient Access to the Functionalized Bicyclic Pharmacophore of Spirolide C by Using a Selective Diels–Alder Reaction. ASIAN J ORG CHEM 2017. [DOI: 10.1002/ajoc.201700164] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Hiroshi Tsuchikawa
- Graduate School of Science Osaka University 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
| | - Kou Minamino
- Graduate School of Science Osaka University 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
| | - Sho Hayashi
- Graduate School of Science Osaka University 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
| | - Michio Murata
- Graduate School of Science Osaka University 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
- ERATO Lipid Active Structure Project Science and Technology Agency 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
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36
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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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37
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Al Muftah A, Selwood AI, Foss AJ, Al-Jabri HMS, Potts M, Yilmaz M. Algal toxins and producers in the marine waters of Qatar, Arabian Gulf. Toxicon 2016; 122:54-66. [DOI: 10.1016/j.toxicon.2016.09.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 09/18/2016] [Accepted: 09/20/2016] [Indexed: 10/21/2022]
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Coutsias EA, Lexa KW, Wester MJ, Pollock SN, Jacobson MP. Exhaustive Conformational Sampling of Complex Fused Ring Macrocycles Using Inverse Kinematics. J Chem Theory Comput 2016; 12:4674-87. [PMID: 27447193 PMCID: PMC5465426 DOI: 10.1021/acs.jctc.6b00250] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Natural product and synthetic macrocycles are chemically and topologically diverse. An efficient, accurate, and general method for generating macrocycle conformations would enable structure-based design of macrocycle drugs or host-guest complexes. Computational sampling also provides insight into transiently populated states, complementing crystallographic and NMR data. Here, we report a new algorithm, BRIKARD, that addresses this challenge through computational algebraic geometry and inverse kinematics together with local energy minimization. BRIKARD is demonstrated on 67 diverse macrocycles with structural data, encompassing various ring topologies. We find this approach enumerates diverse structures with macrocyclic RMSD < 1.0 Å to the experimental conformation for 85% of our data set in contrast to success rates of 67-75% with other approaches, while for the subset of 21 more challenging compounds in the data set, these rates are 57% and 10-29%, respectively. Because the algorithm can be efficiently run in parallel on many processors, exhaustive conformational sampling of complex cycles can be obtained in minutes rather than hours: with a 40 processor implementation protocol, BRIKARD samples the conformational diversity of a potential energy landscape in a median of 1.3 minutes of wallclock time, much faster than 3.1-10.3 hours necessary with current programs. By rigorously testing BRIKARD on a broad range of scaffolds with highly complex ring systems, we push the frontiers of macrocycle sampling to encompass multiring compounds, including those with more than 50 ring atoms and up to seven interlaced flexible rings.
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Affiliation(s)
- Evangelos A. Coutsias
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York 11794, United States
| | - Katrina W. Lexa
- Department of Pharmaceutical Chemistry, University of California in San Francisco, San Francisco, California 94107, United States
| | - Michael J. Wester
- New Mexico Center for Spatiotemporal Modeling of Cell Signaling, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Sara N. Pollock
- Department of Mathematics, Texas A&M University, College Station, Texas 77843, United States
| | - Matthew P. Jacobson
- Department of Pharmaceutical Chemistry, University of California in San Francisco, San Francisco, California 94107, United States
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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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40
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Remya C, Dileep KV, Variayr EJ, Sadasivan C. An in silico guided identification of nAChR agonists from Withania somnifera. FRONTIERS IN LIFE SCIENCE 2016. [DOI: 10.1080/21553769.2016.1207569] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- C. Remya
- Department of Biotechnology and Microbiology and Inter-University Centre for Bioscience, Kannur University, Palayad, India
| | - K. V. Dileep
- School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - E. J. Variayr
- Department of Biotechnology and Microbiology and Inter-University Centre for Bioscience, Kannur University, Palayad, India
| | - C. Sadasivan
- Department of Biotechnology and Microbiology and Inter-University Centre for Bioscience, Kannur University, Palayad, India
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41
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Anttila M, Strangman W, York R, Tomas C, Wright JLC. Biosynthetic Studies of 13-Desmethylspirolide C Produced by Alexandrium ostenfeldii (= A. peruvianum): Rationalization of the Biosynthetic Pathway Following Incorporation of (13)C-Labeled Methionine and Application of the Odd-Even Rule of Methylation. JOURNAL OF NATURAL PRODUCTS 2016; 79:484-489. [PMID: 26641306 DOI: 10.1021/acs.jnatprod.5b00869] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Understanding the biosynthesis of dinoflagellate polyketides presents many unique challenges. Because of the remaining hurdles to dinoflagellate genome sequencing, precursor labeling studies remain the only viable way to investigate dinoflagellate biosynthesis. However, prior studies have shown that polyketide chain assembly does not follow any of the established processes. Additionally, acetate, the common precursor for polyketides, is frequently scrambled, thus compromising interpretation. These factors are further compounded by low production yields of the compounds of interest. A recent report on the biosynthesis of spirolides, a group belonging to the growing class of toxic spiroimines, provided some insight into the polyketide assembly process based on acetate labeling studies, but many details were left uncertain. By feeding (13)C methyl-labeled methionine to cultures of Alexandrium ostenfeldii, the producing organism of 13-desmethylspirolide C, and application of the odd-even methylation rule, the complete biosynthetic pathway has been established.
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Affiliation(s)
- Matthew Anttila
- UNCW Center for Marine Science , 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, United States
| | - Wendy Strangman
- UNCW Center for Marine Science , 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, United States
| | - Robert York
- UNCW Center for Marine Science , 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, United States
| | - Carmelo Tomas
- UNCW Center for Marine Science , 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, United States
| | - Jeffrey L C Wright
- UNCW Center for Marine Science , 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, United States
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42
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Bourne Y, Sharpless KB, Taylor P, Marchot P. Steric and Dynamic Parameters Influencing In Situ Cycloadditions to Form Triazole Inhibitors with Crystalline Acetylcholinesterase. J Am Chem Soc 2016; 138:1611-21. [PMID: 26731630 DOI: 10.1021/jacs.5b11384] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ligand binding sites on acetylcholinesterase (AChE) comprise an active center, at the base of a deep and narrow gorge lined by aromatic residues, and a peripheral site at the gorge entry. These features launched AChE as a reaction vessel for in situ click-chemistry synthesis of high-affinity TZ2PA6 and TZ2PA5 inhibitors, forming a syn-triazole upon cycloaddition within the gorge from alkyne and azide reactants bound at the two sites, respectively. Subsequent crystallographic analyses of AChE complexes with the TZ2PA6 regioisomers demonstrated that syn product association is accompanied by side chain reorganization within the gorge, freezing-in-frame a conformation distinct from an unbound state or anti complex. To correlate inhibitor dimensions with reactivity and explore whether in situ cycloaddition could be accelerated in a concentrated, crystalline template, we developed crystal-soaking procedures and solved structures of AChE complexes with the TZ2PA5 regioisomers and their TZ2/PA5 precursors (2.1-2.7 Å resolution). The structures reveal motions of residue His447 in the active site and, unprecedentedly, residue Tyr341 at the gorge mouth, associated with TZ2 binding and coordinated with other side chain motions in the gorge that may guide AChE toward a transient state favoring syn-triazole formation. Despite precursor binding to crystalline AChE, coupling of rapid electric field fluctuations in the gorge with proper alignments of the azide and alkyne reactants to form the triazole remains a likely limiting step. These observations point to a prime requirement for AChE to interconvert dynamically between sequential conformations to promote favorable electrostatic factors enabling a productive apposition of the reactants for reactivity.
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Affiliation(s)
- Yves Bourne
- Aix-Marseille Université, laboratory Architecture et Fonction des Macromolécules Biologiques, Faculté des Sciences de Luminy , 13288 Marseille cedex 09, France.,Centre National de la Recherche Scientifique, laboratory Architecture et Fonction des Macromolécules Biologiques, Faculté des Sciences de Luminy , 13288 Marseille cedex 09, France
| | - K Barry Sharpless
- Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute , La Jolla, California 92037, United States
| | - Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego , La Jolla, California 92093-0650, United States
| | - Pascale Marchot
- Aix-Marseille Université, laboratory Architecture et Fonction des Macromolécules Biologiques, Faculté des Sciences de Luminy , 13288 Marseille cedex 09, France.,Centre National de la Recherche Scientifique, laboratory Architecture et Fonction des Macromolécules Biologiques, Faculté des Sciences de Luminy , 13288 Marseille cedex 09, France
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43
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Shahsavar A, Gajhede M, Kastrup JS, Balle T. Structural Studies of Nicotinic Acetylcholine Receptors: Using Acetylcholine-Binding Protein as a Structural Surrogate. Basic Clin Pharmacol Toxicol 2016; 118:399-407. [DOI: 10.1111/bcpt.12528] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/02/2015] [Indexed: 01/09/2023]
Affiliation(s)
- Azadeh Shahsavar
- Department of Molecular Biology and Genetics; Danish Research Institute of Translational Neuroscience - DANDRITE; Aarhus University; Aarhus Denmark
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - Michael Gajhede
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - Jette S. Kastrup
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; University of Copenhagen; Copenhagen Denmark
| | - Thomas Balle
- Faculty of Pharmacy; The University of Sydney; Sydney NSW Australia
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44
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Davidson K, Baker C, Higgins C, Higman W, Swan S, Veszelovszki A, Turner AD. Potential Threats Posed by New or Emerging Marine Biotoxins in UK Waters and Examination of Detection Methodologies Used for Their Control: Cyclic Imines. Mar Drugs 2015; 13:7087-112. [PMID: 26703628 PMCID: PMC4699231 DOI: 10.3390/md13127057] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 10/28/2015] [Accepted: 11/03/2015] [Indexed: 11/16/2022] Open
Abstract
Cyclic imines (CIs) are a group of phytoplankton produced toxins related to shellfish food products, some of which are already present in UK and European waters. Their risk to shellfish consumers is poorly understood, as while no human intoxication has been definitively related to this group, their fast acting toxicity following intraperitoneal injection in mice has led to concern over their human health implications. A request was therefore made by UK food safety authorities to examine these toxins more closely to aid possible management strategies. Of the CI producers only the spirolide producer Alexandrium ostenfeldii is known to exist in UK waters at present but trends in climate change may lead to increased risk from other organisms/CI toxins currently present elsewhere in Europe and in similar environments worldwide. This paper reviews evidence concerning the prevalence of CIs and CI-producing phytoplankton, together with testing methodologies. Chemical, biological and biomolecular methods are reviewed, including recommendations for further work to enable effective testing. Although the focus here is on the UK, from a strategic standpoint many of the topics discussed will also be of interest in other parts of the world since new and emerging marine biotoxins are of global concern.
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Affiliation(s)
- Keith Davidson
- Scottish Association for Marine Science, Scottish Marine Institute, Oban PA37 1QA, Scotland, UK.
| | - Clothilde Baker
- Centre for Environment Fisheries and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, UK.
| | - Cowan Higgins
- Agri-food and Biosciences Institute (AFBI), Newforge Lane, Belfast BT9 5PX, Northern Ireland, UK.
| | - Wendy Higman
- Centre for Environment Fisheries and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, UK.
| | - Sarah Swan
- Scottish Association for Marine Science, Scottish Marine Institute, Oban PA37 1QA, Scotland, UK.
| | - Andrea Veszelovszki
- Scottish Association for Marine Science, Scottish Marine Institute, Oban PA37 1QA, Scotland, UK.
| | - Andrew D Turner
- Centre for Environment Fisheries and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, UK.
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45
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Bertrand D, Lee CHL, Flood D, Marger F, Donnelly-Roberts D. Therapeutic Potential of α7 Nicotinic Acetylcholine Receptors. Pharmacol Rev 2015; 67:1025-73. [DOI: 10.1124/pr.113.008581] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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46
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Stivala CE, Benoit E, Aráoz R, Servent D, Novikov A, Molgó J, Zakarian A. Synthesis and biology of cyclic imine toxins, an emerging class of potent, globally distributed marine toxins. Nat Prod Rep 2015; 32:411-35. [PMID: 25338021 DOI: 10.1039/c4np00089g] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
From a small group of exotic compounds isolated only two decades ago, Cyclic Imine (CI) toxins have become a major class of marine toxins with global distribution. Their distinct chemical structure, biological mechanism of action, and intricate chemistry ensures that CI toxins will continue to be the subject of fascinating fundamental studies in the broad fields of chemistry, chemical biology, and toxicology. The worldwide occurrence of potent CI toxins in marine environments, their accumulation in shellfish, and chemical stability are important considerations in assessing risk factors for human health. This review article aims to provide an account of chemistry, biology, and toxicology of CI toxins from their discovery to the present day.
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Affiliation(s)
- Craig E Stivala
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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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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Chiodo L, Malliavin TE, Maragliano L, Cottone G, Ciccotti G. A Structural Model of the Human α7 Nicotinic Receptor in an Open Conformation. PLoS One 2015; 10:e0133011. [PMID: 26208301 PMCID: PMC4514475 DOI: 10.1371/journal.pone.0133011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 06/22/2015] [Indexed: 11/20/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAchRs) are ligand-gated ion channels that regulate chemical transmission at the neuromuscular junction. Structural information is available at low resolution from open and closed forms of an eukaryotic receptor, and at high resolution from other members of the same structural family, two prokaryotic orthologs and an eukaryotic GluCl channel. Structures of human channels however are still lacking. Homology modeling and Molecular Dynamics simulations are valuable tools to predict structures of unknown proteins, however, for the case of human nAchRs, they have been unsuccessful in providing a stable open structure so far. This is due to different problems with the template structures: on one side the homology with prokaryotic species is too low, while on the other the open eukaryotic GluCl proved itself unstable in several MD studies and collapsed to a dehydrated, non-conductive conformation, even when bound to an agonist. Aim of this work is to obtain, by a mixing of state-of-the-art homology and simulation techniques, a plausible prediction of the structure (still unknown) of the open state of human α7 nAChR complexed with epibatidine, from which it is possible to start structural and functional test studies. To prevent channel closure we employ a restraint that keeps the transmembrane pore open, and obtain in this way a stable, hydrated conformation. To further validate this conformation, we run four long, unbiased simulations starting from configurations chosen at random along the restrained trajectory. The channel remains stable and hydrated over the whole runs. This allows to assess the stability of the putative open conformation over a cumulative time of 1 μs, 800 ns of which are of unbiased simulation. Mostly based on the analysis of pore hydration and size, we suggest that the obtained structure has reasonable chances to be (at least one of the possible) structures of the channel in the open conformation.
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Affiliation(s)
- Letizia Chiodo
- Center for Life Nano Science @Sapienza, Istituto Italiano di Tecnologia, Rome, Italy
| | - Thérèse E. Malliavin
- Institut Pasteur and CNRS UMR 3528, Unité de Bioinformatique Structurale, Paris, France
| | - Luca Maragliano
- Center for Synaptic Neuroscience, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Grazia Cottone
- Department of Physics and Chemistry, University of Palermo, Palermo, Italy
- School of Physics, University College Dublin, Dublin, Ireland
| | - Giovanni Ciccotti
- School of Physics, University College Dublin, Dublin, Ireland
- Department of Physics, University of Roma “La Sapienza”, Rome, Italy
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Aráoz R, Ouanounou G, Iorga BI, Goudet A, Alili D, Amar M, Benoit E, Molgó J, Servent D. The Neurotoxic Effect of 13,19-Didesmethyl and 13-Desmethyl Spirolide C Phycotoxins Is Mainly Mediated by Nicotinic Rather Than Muscarinic Acetylcholine Receptors. Toxicol Sci 2015; 147:156-67. [DOI: 10.1093/toxsci/kfv119] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Bourne Y, Sulzenbacher G, Radić Z, Aráoz R, Reynaud M, Benoit E, Zakarian A, Servent D, Molgó J, Taylor P, Marchot P. Marine Macrocyclic Imines, Pinnatoxins A and G: Structural Determinants and Functional Properties to Distinguish Neuronal α7 from Muscle α1(2)βγδ nAChRs. Structure 2015; 23:1106-15. [PMID: 26004441 DOI: 10.1016/j.str.2015.04.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 04/03/2015] [Accepted: 04/04/2015] [Indexed: 10/23/2022]
Abstract
Pinnatoxins are macrocyclic imine phycotoxins associated with algal blooms and shellfish toxicity. Functional analysis of pinnatoxin A and pinnatoxin G by binding and voltage-clamp electrophysiology on membrane-embedded neuronal α7, α4β2, α3β2, and muscle-type α12βγδ nicotinic acetylcholine receptors (nAChRs) reveals high-affinity binding and potent antagonism for the α7 and α12βγδ subtypes. The toxins also bind to the nAChR surrogate, acetylcholine-binding protein (AChBP), with low Kd values reflecting slow dissociation. Crystal structures of pinnatoxin-AChBP complexes (1.9-2.2 Å resolution) show the multiple anchoring points of the hydrophobic portion, the cyclic imine, and the substituted bis-spiroketal and cyclohexene ring systems of the pinnatoxins that dictate tight binding between the opposing loops C and F at the receptor subunit interface, as observed for the 13-desmethyl-spirolide C and gymnodimine A congeners. Uniquely, however, the bulky bridged EF-ketal ring specific to the pinnatoxins extends radially from the interfacial-binding pocket to interact with the sequence-variable loop F and govern nAChR subtype selectivity and central neurotoxicity.
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Affiliation(s)
- Yves Bourne
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France; Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France.
| | - Gerlind Sulzenbacher
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France; Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France
| | - Zoran Radić
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093-0650, USA
| | - Rómulo Aráoz
- Institut des Neurosciences Paris-Saclay, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Morgane Reynaud
- Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Evelyne Benoit
- Institut des Neurosciences Paris-Saclay, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Armen Zakarian
- Department of Chemistry and Biochemistry, University of California Santa Barbara, CA 93106-9510, USA
| | - Denis Servent
- Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Jordi Molgó
- Institut des Neurosciences Paris-Saclay, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France; Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Palmer Taylor
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093-0650, USA
| | - Pascale Marchot
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France; Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, Campus Luminy, 13288 Marseille cedex 9, France.
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