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Dobson JS, Harris RJ, Zdenek CN, Huynh T, Hodgson WC, Bosmans F, Fourmy R, Violette A, Fry BG. The Dragon's Paralysing Spell: Evidence of Sodium and Calcium Ion Channel Binding Neurotoxins in Helodermatid and Varanid Lizard Venoms. Toxins (Basel) 2021; 13:toxins13080549. [PMID: 34437420 PMCID: PMC8402328 DOI: 10.3390/toxins13080549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 12/19/2022] Open
Abstract
Bites from helodermatid lizards can cause pain, paresthesia, paralysis, and tachycardia, as well as other symptoms consistent with neurotoxicity. Furthermore, in vitro studies have shown that Heloderma horridum venom inhibits ion flux and blocks the electrical stimulation of skeletal muscles. Helodermatids have long been considered the only venomous lizards, but a large body of robust evidence has demonstrated venom to be a basal trait of Anguimorpha. This clade includes varanid lizards, whose bites have been reported to cause anticoagulation, pain, and occasionally paralysis and tachycardia. Despite the evolutionary novelty of these lizard venoms, their neuromuscular targets have yet to be identified, even for the iconic helodermatid lizards. Therefore, to fill this knowledge gap, the venoms of three Heloderma species (H. exasperatum, H. horridum and H. suspectum) and two Varanus species (V. salvadorii and V. varius) were investigated using Gallus gallus chick biventer cervicis nerve–muscle preparations and biolayer interferometry assays for binding to mammalian ion channels. Incubation with Heloderma venoms caused the reduction in nerve-mediated muscle twitches post initial response of avian skeletal muscle tissue preparation assays suggesting voltage-gated sodium (NaV) channel binding. Congruent with the flaccid paralysis inducing blockage of electrical stimulation in the skeletal muscle preparations, the biolayer interferometry tests with Heloderma suspectum venom revealed binding to the S3–S4 loop within voltage-sensing domain IV of the skeletal muscle channel subtype, NaV1.4. Consistent with tachycardia reported in clinical cases, the venom also bound to voltage-sensing domain IV of the cardiac smooth muscle calcium channel, CaV1.2. While Varanus varius venom did not have discernable effects in the avian tissue preparation assay at the concentration tested, in the biointerferometry assay both V. varius and V. salvadorii bound to voltage-sensing domain IV of both NaV1.4 and CaV1.2, similar to H. suspectum venom. The ability of varanid venoms to bind to mammalian ion channels but not to the avian tissue preparation suggests prey-selective actions, as did the differential potency within the Heloderma venoms for avian versus mammalian pathophysiological targets. This study thus presents the detailed characterization of Heloderma venom ion channel neurotoxicity and offers the first evidence of varanid lizard venom neurotoxicity. In addition, the data not only provide information useful to understanding the clinical effects produced by envenomations, but also reveal their utility as physiological probes, and underscore the potential utility of neglected venomous lineages in the drug design and development pipeline.
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Affiliation(s)
- James S. Dobson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia, QLD 4072, Australia; (J.S.D.); (R.J.H.); (C.N.Z.)
| | - Richard J. Harris
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia, QLD 4072, Australia; (J.S.D.); (R.J.H.); (C.N.Z.)
| | - Christina N. Zdenek
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia, QLD 4072, Australia; (J.S.D.); (R.J.H.); (C.N.Z.)
| | - Tam Huynh
- Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (T.H.); (W.C.H.)
| | - Wayne C. Hodgson
- Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (T.H.); (W.C.H.)
| | - Frank Bosmans
- Department of Basic and Applied Medical Sciences, Ghent University, 9000 Ghent, Belgium;
| | - Rudy Fourmy
- Alphabiotoxine Laboratory sprl, Barberie 15, 7911 Montroeul-au-Bois, Belgium; (R.F.); (A.V.)
| | - Aude Violette
- Alphabiotoxine Laboratory sprl, Barberie 15, 7911 Montroeul-au-Bois, Belgium; (R.F.); (A.V.)
| | - Bryan G. Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia, QLD 4072, Australia; (J.S.D.); (R.J.H.); (C.N.Z.)
- Correspondence: ; Tel.: +61-7-336-58515
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op den Brouw B, Coimbra FCP, Bourke LA, Huynh TM, Vlecken DHW, Ghezellou P, Visser JC, Dobson JS, Fernandez-Rojo MA, Ikonomopoulou MP, Casewell NR, Ali SA, Fathinia B, Hodgson WC, Fry BG. Extensive Variation in the Activities of Pseudocerastes and Eristicophis Viper Venoms Suggests Divergent Envenoming Strategies Are Used for Prey Capture. Toxins (Basel) 2021; 13:112. [PMID: 33540884 PMCID: PMC7913145 DOI: 10.3390/toxins13020112] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/27/2021] [Accepted: 01/27/2021] [Indexed: 11/28/2022] Open
Abstract
Snakes of the genera Pseudocerastes and Eristicophis (Viperidae: Viperinae) are known as the desert vipers due to their association with the arid environments of the Middle East. These species have received limited research attention and little is known about their venom or ecology. In this study, a comprehensive analysis of desert viper venoms was conducted by visualising the venom proteomes via gel electrophoresis and assessing the crude venoms for their cytotoxic, haemotoxic, and neurotoxic properties. Plasmas sourced from human, toad, and chicken were used as models to assess possible prey-linked venom activity. The venoms demonstrated substantial divergence in composition and bioactivity across all experiments. Pseudocerastes urarachnoides venom activated human coagulation factors X and prothrombin and demonstrated potent procoagulant activity in human, toad, and chicken plasmas, in stark contrast to the potent neurotoxic venom of P. fieldi. The venom of E. macmahonii also induced coagulation, though this did not appear to be via the activation of factor X or prothrombin. The coagulant properties of P. fieldi and P. persicus venoms varied among plasmas, demonstrating strong anticoagulant activity in the amphibian and human plasmas but no significant effect in that of bird. This is conjectured to reflect prey-specific toxin activity, though further ecological studies are required to confirm any dietary associations. This study reinforces the notion that phylogenetic relatedness of snakes cannot readily predict venom protein composition or function. The significant venom variation between these species raises serious concerns regarding antivenom paraspecificity. Future assessment of antivenom is crucial.
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Affiliation(s)
- Bianca op den Brouw
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
| | - Francisco C. P. Coimbra
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
| | - Lachlan A. Bourke
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
| | - Tam Minh Huynh
- Monash Venom Group, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, VIC 3800, Australia; (T.M.H.); (W.C.H.)
| | - Danielle H. W. Vlecken
- Department of Animal Science and Health, Institute of Biology Leiden, 2333 BE Leiden, The Netherlands;
| | - Parviz Ghezellou
- Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, 1983969411 Tehran, Iran;
- Institute of Inorganic and Analytical Chemistry, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Jeroen C. Visser
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
| | - James S. Dobson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
| | - Manuel A. Fernandez-Rojo
- Madrid Institute for Advanced Studies in Food, E28049 Madrid, Spain; (M.A.F.-R.); (M.P.I.)
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Maria P. Ikonomopoulou
- Madrid Institute for Advanced Studies in Food, E28049 Madrid, Spain; (M.A.F.-R.); (M.P.I.)
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nicholas R. Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK;
| | - Syed A. Ali
- HEJ Research Institute of Chemistry, International Centre for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi 75270, Pakistan;
| | - Behzad Fathinia
- Department of Biology, Faculty of Science, Yasouj University, 75914 Yasouj, Iran;
| | - Wayne C. Hodgson
- Monash Venom Group, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, VIC 3800, Australia; (T.M.H.); (W.C.H.)
| | - Bryan G. Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
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Chowdhury A, Zdenek CN, Dobson JS, Bourke LA, Soria R, Fry BG. Clinical implications of differential procoagulant toxicity of the palearctic viperid genus Macrovipera, and the relative neutralization efficacy of antivenoms and enzyme inhibitors. Toxicol Lett 2021; 340:77-88. [PMID: 33412251 DOI: 10.1016/j.toxlet.2020.12.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/22/2020] [Accepted: 12/29/2020] [Indexed: 12/20/2022]
Abstract
Species within the viperid genus Macrovipera are some of the most dangerous snakes in the Eurasian region, injecting copious amounts of potent venom. Despite their medical importance, the pathophysiological actions of their venoms have been neglected. Particularly poorly known are the coagulotoxic effects and thus the underlying mechanisms of lethal coagulopathy. In order to fill this knowledge gap, we ascertained the effects of venom upon human plasma for Macrovipera lebetina cernovi, M. l. lebetina, M. l. obtusa, M. l. turanica, and M. schweizeri using diverse coagulation analysing protocols. All five were extremely potent in their ability to promote clotting but varied in their relative activation of Factor X, being equipotent in this study to the venom of the better studied, and lethal, species Daboia russelii. The Insoserp European viper antivenom was shown to be highly effective against all the Macrovipera venoms, but performed poorly against the D. russelii venom. Reciprocally, while Daboia antivenoms performed well against D. russelii venom, they failed against Macrovipera venom. Thus despite the two genera sharing a venom phenotype (Factor X activation) driven by the same toxin type (P-IIId snake venom metalloproteases), the surface biochemistries of the toxins differed significantly enough to impede antivenom cross- neutralization. The differences in venom biochemistry were reflected in coagulation co-factor dependence. While both genera were absolutely dependent upon calcium for the activation of Factor X, dependence upon phospholipid varied. The Macrovipera venoms had low levels of dependence upon phospholipid while the Daboia venom was three times more dependent upon phospholipid for the activation of Factor X. This suggests that the sites on the molecular surface responsible for phospholipid dependence, are the same differential sites that prevent inter-genera antivenom cross- neutralization. Due to cold-chain requirements, antivenoms may not be stocked in rural settings where the need is at the greatest. Thus we tested the efficacy of enzyme inhibitor Prinomastat as a field-deployable treatment to stabilise patients while being transported to antivenom stocks, and showed that it was extremely effective in blocking the Factor X activating pathophysiological actions. Marimastat however was less effective. These results thus not only shed light on the coagulopathic mechanisms of Macrovipera venoms, but also provide data critical for evidence-based design of snakebite management strategies.
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Affiliation(s)
- Abhinandan Chowdhury
- Toxin Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, 4072, Australia; Department of Biochemistry & Microbiology, North South University, Dhaka, 1229, Bangladesh
| | - Christina N Zdenek
- Toxin Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - James S Dobson
- Toxin Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Lachlan A Bourke
- Toxin Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Raul Soria
- Inosan Biopharma, S.A. Arbea Campus Empresarial, Edificio 2, Planta 2, Carretera Fuencarral a Alcobendas, Km 3.8, 28108, Madrid, Spain
| | - Bryan G Fry
- Toxin Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD, 4072, Australia.
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Grashof D, Zdenek CN, Dobson JS, Youngman NJ, Coimbra F, Benard-Valle M, Alagon A, Fry BG. A Web of Coagulotoxicity: Failure of Antivenom to Neutralize the Destructive (Non-Clotting) Fibrinogenolytic Activity of Loxosceles and Sicarius Spider Venoms. Toxins (Basel) 2020; 12:toxins12020091. [PMID: 32019058 PMCID: PMC7076800 DOI: 10.3390/toxins12020091] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/14/2020] [Accepted: 01/22/2020] [Indexed: 12/14/2022] Open
Abstract
Envenomations are complex medical emergencies that can have a range of symptoms and sequelae. The only specific, scientifically-validated treatment for envenomation is antivenom administration, which is designed to alleviate venom effects. A paucity of efficacy testing exists for numerous antivenoms worldwide, and understanding venom effects and venom potency can help identify antivenom improvement options. Some spider venoms can produce debilitating injuries or even death, yet have been largely neglected in venom and antivenom studies because of the low venom yields. Coagulation disturbances have been particularly under studied due to difficulties in working with blood and the coagulation cascade. These circumstances have resulted in suboptimal spider bite treatment for medically significant spider genera such as Loxosceles and Sicarius. This study identifies and quantifies the anticoagulant effects produced by venoms of three Loxoscles species (L. reclusa, L. boneti, and L. laeta) and that of Sicarius terrosus. We showed that the venoms of all studied species are able to cleave the fibrinogen Aα-chain with varying degrees of potency, with L. reclusa and S. terrosus venom cleaving the Aα-chain most rapidly. Thromboelastography analysis revealed that only L. reclusa venom is able to reduce clot strength, thereby presumably causing anticoagulant effects in the patient. Using the same thromboelastography assays, antivenom efficacy tests revealed that the commonly used Loxoscles-specific SMase D recombinant based antivenom failed to neutralize the anticoagulant effects produced by Loxosceles venom. This study demonstrates the fibrinogenolytic activity of Loxosceles and Sicarius venom and the neutralization failure of Loxosceles antivenom, thus providing impetus for antivenom improvement.
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Affiliation(s)
- Dwin Grashof
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (D.G.); (C.N.Z.); (J.S.D.); (N.J.Y.); (F.C.)
| | - Christina N. Zdenek
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (D.G.); (C.N.Z.); (J.S.D.); (N.J.Y.); (F.C.)
| | - James S. Dobson
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (D.G.); (C.N.Z.); (J.S.D.); (N.J.Y.); (F.C.)
| | - Nicholas J. Youngman
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (D.G.); (C.N.Z.); (J.S.D.); (N.J.Y.); (F.C.)
| | - Francisco Coimbra
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (D.G.); (C.N.Z.); (J.S.D.); (N.J.Y.); (F.C.)
| | - Melisa Benard-Valle
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, Mexico; (M.B.-V.); (A.A.)
| | - Alejandro Alagon
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, Mexico; (M.B.-V.); (A.A.)
| | - Bryan G. Fry
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (D.G.); (C.N.Z.); (J.S.D.); (N.J.Y.); (F.C.)
- Correspondence:
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Scheib H, Nekaris KAI, Rode-Margono J, Ragnarsson L, Baumann K, Dobson JS, Wirdateti W, Nouwens A, Nijman V, Martelli P, Ma R, Lewis RJ, Kwok HF, Fry BG. The Toxicological Intersection between Allergen and Toxin: A Structural Comparison of the Cat Dander Allergenic Protein Fel d1 and the Slow Loris Brachial Gland Secretion Protein. Toxins (Basel) 2020; 12:toxins12020086. [PMID: 32012831 PMCID: PMC7076782 DOI: 10.3390/toxins12020086] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/22/2020] [Accepted: 01/23/2020] [Indexed: 12/27/2022] Open
Abstract
Slow lorises are enigmatic animal that represent the only venomous primate lineage. Their defensive secretions have received little attention. In this study we determined the full length sequence of the protein secreted by their unique brachial glands. The full length sequences displayed homology to the main allergenic protein present in cat dander. We thus compared the molecular features of the slow loris brachial gland protein and the cat dander allergen protein, showing remarkable similarities between them. Thus we postulate that allergenic proteins play a role in the slow loris defensive arsenal. These results shed light on these neglected, novel animals.
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Affiliation(s)
- Holger Scheib
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia; (H.S.); (K.B.); (J.S.D.)
| | - K. Anne-Isola Nekaris
- Nocturnal Primate Research Group, Department of Social Sciences, Oxford Brookes University, Oxford OX3 0BP, UK; (K.A.-I.N.); (J.R.-M.); (V.N.)
- Centre for Functional Genomics, Department of Health and Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Johanna Rode-Margono
- Nocturnal Primate Research Group, Department of Social Sciences, Oxford Brookes University, Oxford OX3 0BP, UK; (K.A.-I.N.); (J.R.-M.); (V.N.)
- The North of England Zoological Society / Chester Zoo, Chester CH2 1LH, UK
| | - Lotten Ragnarsson
- Institute for Molecular Biosciences, University of Queensland, St Lucia QLD 4072, Australia; (L.R.)
| | - Kate Baumann
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia; (H.S.); (K.B.); (J.S.D.)
| | - James S. Dobson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia; (H.S.); (K.B.); (J.S.D.)
| | | | - Amanda Nouwens
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Qld 4072, Australia;
| | - Vincent Nijman
- Nocturnal Primate Research Group, Department of Social Sciences, Oxford Brookes University, Oxford OX3 0BP, UK; (K.A.-I.N.); (J.R.-M.); (V.N.)
- Centre for Functional Genomics, Department of Health and Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | | | - Rui Ma
- Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Avenida de Universidade, Taipa, Macau SAR;
| | - Richard J. Lewis
- Institute for Molecular Biosciences, University of Queensland, St Lucia QLD 4072, Australia; (L.R.)
| | - Hang Fai Kwok
- Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Avenida de Universidade, Taipa, Macau SAR;
- Correspondence: (H.F.K.); (B.G.F.)
| | - Bryan Grieg Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia; (H.S.); (K.B.); (J.S.D.)
- Correspondence: (H.F.K.); (B.G.F.)
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Zdenek CN, Harris RJ, Kuruppu S, Youngman NJ, Dobson JS, Debono J, Khan M, Smith I, Yarski M, Harrich D, Sweeney C, Dunstan N, Allen L, Fry BG. A Taxon-Specific and High-Throughput Method for Measuring Ligand Binding to Nicotinic Acetylcholine Receptors. Toxins (Basel) 2019; 11:toxins11100600. [PMID: 31623073 PMCID: PMC6832995 DOI: 10.3390/toxins11100600] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 09/29/2019] [Accepted: 10/01/2019] [Indexed: 02/07/2023] Open
Abstract
The binding of compounds to nicotinic acetylcholine receptors is of great interest in biomedical research. However, progress in this area is hampered by the lack of a high-throughput, cost-effective, and taxonomically flexible platform. Current methods are low-throughput, consume large quantities of sample, or are taxonomically limited in which targets can be tested. We describe a novel assay which utilizes a label-free bio-layer interferometry technology, in combination with adapted mimotope peptides, in order to measure ligand binding to the orthosteric site of nicotinic acetylcholine receptor alpha-subunits of diverse organisms. We validated the method by testing the evolutionary patterns of a generalist feeding species (Acanthophis antarcticus), a fish specialist species (Aipysurus laevis), and a snake specialist species (Ophiophagus hannah) for comparative binding to the orthosteric site of fish, amphibian, lizard, snake, bird, marsupial, and rodent alpha-1 nicotinic acetylcholine receptors. Binding patterns corresponded with diet, with the Acanthophis antarcticus not showing bias towards any particular lineage, while Aipysurus laevis showed selectivity for fish, and Ophiophagus hannah a selectivity for snake. To validate the biodiscovery potential of this method, we screened Acanthophis antarcticus and Tropidolaemus wagleri venom for binding to human alpha-1, alpha-2, alpha-3, alpha-4, alpha-5, alpha-6, alpha-7, alpha-9, and alpha-10. While A. antarcticus was broadly potent, T. wagleri showed very strong but selective binding, specifically to the alpha-1 target which would be evolutionarily selected for, as well as the alpha-5 target which is of major interest for drug design and development. Thus, we have shown that our novel method is broadly applicable for studies including evolutionary patterns of venom diversification, predicting potential neurotoxic effects in human envenomed patients, and searches for novel ligands of interest for laboratory tools and in drug design and development.
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Affiliation(s)
- Christina N. Zdenek
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.N.Z.); (R.J.H.); (N.J.Y.); (J.S.D.); (J.D.)
| | - Richard J. Harris
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.N.Z.); (R.J.H.); (N.J.Y.); (J.S.D.); (J.D.)
| | - Sanjaya Kuruppu
- Department of Biochemistry & Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (S.K.); (I.S.)
| | - Nicholas J. Youngman
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.N.Z.); (R.J.H.); (N.J.Y.); (J.S.D.); (J.D.)
| | - James S. Dobson
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.N.Z.); (R.J.H.); (N.J.Y.); (J.S.D.); (J.D.)
| | - Jordan Debono
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.N.Z.); (R.J.H.); (N.J.Y.); (J.S.D.); (J.D.)
| | - Muzaffar Khan
- Institute of Biology, Leiden University (IBL), Sylvius Laboratory, Sylviusweg 72, 2333 BE Leiden, The Netherlands;
| | - Ian Smith
- Department of Biochemistry & Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (S.K.); (I.S.)
| | - Mike Yarski
- Millennium Science, 4 Miles Street Mulgrave, VIC 3170, Australia;
| | - David Harrich
- QIMR Berghofer, Royal Brisbane Hospital QLD 4029, Australia;
| | - Charlotte Sweeney
- Translational Research Institute, University of Queensland, QLD 4072, Australia;
| | - Nathan Dunstan
- Venom Supplies Pty Ltd., Stonewell Rd, Tanunda, SA 5352, (L.A.)
| | - Luke Allen
- Venom Supplies Pty Ltd., Stonewell Rd, Tanunda, SA 5352, (L.A.)
| | - Bryan G. Fry
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.N.Z.); (R.J.H.); (N.J.Y.); (J.S.D.); (J.D.)
- Correspondence: ; Tel.: +61-7-336-58515
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Bittenbinder MA, Dobson JS, Zdenek CN, op den Brouw B, Naude A, Vonk FJ, Fry BG. Differential destructive (non-clotting) fibrinogenolytic activity in Afro-Asian elapid snake venoms and the links to defensive hooding behavior. Toxicol In Vitro 2019; 60:330-335. [DOI: 10.1016/j.tiv.2019.05.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 05/29/2019] [Accepted: 05/30/2019] [Indexed: 12/23/2022]
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Dobson JS, Zdenek CN, Hay C, Violette A, Fourmy R, Cochran C, Fry BG. Varanid Lizard Venoms Disrupt the Clotting Ability of Human Fibrinogen through Destructive Cleavage. Toxins (Basel) 2019; 11:E255. [PMID: 31067768 PMCID: PMC6563220 DOI: 10.3390/toxins11050255] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/30/2019] [Accepted: 05/01/2019] [Indexed: 02/06/2023] Open
Abstract
The functional activities of Anguimorpha lizard venoms have received less attention compared to serpent lineages. Bite victims of varanid lizards often report persistent bleeding exceeding that expected for the mechanical damage of the bite. Research to date has identified the blockage of platelet aggregation as one bleeding-inducing activity, and destructive cleavage of fibrinogen as another. However, the ability of the venoms to prevent clot formation has not been directly investigated. Using a thromboelastograph (TEG5000), clot strength was measured after incubating human fibrinogen with Heloderma and Varanus lizard venoms. Clot strengths were found to be highly variable, with the most potent effects produced by incubation with Varanus venoms from the Odatria and Euprepriosaurus clades. The most fibrinogenolytically active venoms belonged to arboreal species and therefore prey escape potential is likely a strong evolutionary selection pressure. The results are also consistent with reports of profusive bleeding from bites from other notably fibrinogenolytic species, such as V. giganteus. Our results provide evidence in favour of the predatory role of venom in varanid lizards, thus shedding light on the evolution of venom in reptiles and revealing potential new sources of bioactive molecules useful as lead compounds in drug design and development.
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Affiliation(s)
- James S Dobson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Christina N Zdenek
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Chris Hay
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Aude Violette
- Alphabiotoxine Laboratory sprl, Barberie 15, 7911 Montroeul-au-bois, Belgium.
| | - Rudy Fourmy
- Alphabiotoxine Laboratory sprl, Barberie 15, 7911 Montroeul-au-bois, Belgium.
| | - Chip Cochran
- Department of Earth and Biological Sciences, Loma Linda University, Loma Linda, CA 92350, USA.
| | - Bryan G Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
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Bittenbinder MA, Zdenek CN, Op den Brouw B, Youngman NJ, Dobson JS, Naude A, Vonk FJ, Fry BG. Coagulotoxic Cobras: Clinical Implications of Strong Anticoagulant Actions of African Spitting Naja Venoms That Are Not Neutralised by Antivenom but Are by LY315920 (Varespladib). Toxins (Basel) 2018; 10:toxins10120516. [PMID: 30518149 PMCID: PMC6316626 DOI: 10.3390/toxins10120516] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/27/2018] [Accepted: 12/01/2018] [Indexed: 01/15/2023] Open
Abstract
Snakebite is a global tropical disease that has long had huge implications for human health and well-being. Despite its long-standing medical importance, it has been the most neglected of tropical diseases. Reflective of this is that many aspects of the pathology have been underinvestigated. Snakebite by species in the Elapidae family is typically characterised by neurotoxic effects that result in flaccid paralysis. Thus, while clinically significant disturbances to the coagulation cascade have been reported, the bulk of the research to date has focused upon neurotoxins. In order to fill the knowledge gap regarding the coagulotoxic effects of elapid snake venoms, we screened 30 African and Asian venoms across eight genera using in vitro anticoagulant assays to determine the relative inhibition of the coagulation function of thrombin and the inhibition of the formation of the prothrombinase complex through competitive binding to a nonenzymatic site on Factor Xa (FXa), thereby preventing FXa from binding to Factor Va (FVa). It was revealed that African spitting cobras were the only species that were potent inhibitors of either clotting factor, but with Factor Xa inhibited at 12 times the levels of thrombin inhibition. This is consistent with at least one death on record due to hemorrhage following African spitting cobra envenomation. To determine the efficacy of antivenom in neutralising the anticoagulant venom effects, for the African spitting cobras we repeated the same 8-point dilution series with the addition of antivenom and observed the shift in the area under the curve, which revealed that the antivenom performed extremely poorly against the coagulotoxic venom effects of all species. However, additional tests with the phospholipase A2 inhibitor LY315920 (trade name: varespladib) demonstrated a powerful neutralisation action against the coagulotoxic actions of the African spitting cobra venoms. Our research has important implications for the clinical treatment of cobra snakebites and also sheds light on the molecular mechanisms involved in coagulotoxicity within Naja. As the most coagulotoxic species are also those that produce characteristic extreme local tissue damage, future research should investigate potential synergistic actions between anticoagulant toxins and cytotoxins.
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Affiliation(s)
- Mátyás A Bittenbinder
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
- Institute of Biology, Leiden University, 2300 RA Leiden, The Netherlands.
| | - Christina N Zdenek
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Bianca Op den Brouw
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Nicholas J Youngman
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| | - James S Dobson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Arno Naude
- Snakebite Assist, Pretoria ZA-0001, South Africa.
| | - Freek J Vonk
- Naturalis Biodiversity Center, 2333 CR Leiden, The Netherlands.
| | - Bryan G Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
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Abstract
Zika virus (ZV) is an important emerging infection. Rash is a key feature, but the summative literature lacks description of the rash beyond 'maculopapular'. Our aim was to identify the cutaneous features described in the published literature. A literature search using defined terms for ZV cases reports and series was performed on the OVID, Clinical Key and University of Dundee's e-library journals databases in December 2016; a later case report was included while the paper was under review. Diagnosis in all cases was via PCR. Exclusion criteria were Zika cases without rash or omitting any description of the rash. Ocular features (conjunctivitis) were not included. In total, 42 publications with 66 cases met the criteria. The most frequent descriptive features included maculopapular (59%), lower limb petechial purpura (11%) and erythematous/red (9%). Pruritus was described in 44% and tenderness in 3%. Lesions were located on the trunk (29%), limbs (5% arms, 11% both arms and legs), face (17%) and extremities (14%) or were diffuse/generalized (12%). There was facial sparing in 3%. Other features were centrifugal spread (6%), palmar and/or plantar involvement (6%), palmoplantar desquamation (2%) and malar erythema with oedema (2%). Mucosal features included gingival bleeding (11%), oral haemorrhagic blisters (8%) and painful blisters/vesicles (4%). Oedema/swelling was described in the upper limbs (5%), lower limbs (5%) and both (3%). Mean rash duration was 6 days (range 3-11 days). The ZV exanthema is most frequently maculopapular, pruritic, sometimes with centrifugal spread from the trunk to extremities. This may include lower limb petechial purpura, palmoplantar lesions, oedema of limb extremities, and gingival bleeding or painful oral bullae. As ZV becomes more prevalent, recognition of the clinical features will enable earlier diagnosis and appropriate testing.
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Affiliation(s)
- J S Dobson
- Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK
| | - N J Levell
- Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK
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Oulion B, Dobson JS, Zdenek CN, Arbuckle K, Lister C, Coimbra FCP, Op den Brouw B, Debono J, Rogalski A, Violette A, Fourmy R, Frank N, Fry BG. Factor X activating Atractaspis snake venoms and the relative coagulotoxicity neutralising efficacy of African antivenoms. Toxicol Lett 2018; 288:119-128. [PMID: 29462691 DOI: 10.1016/j.toxlet.2018.02.020] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 02/08/2018] [Accepted: 02/13/2018] [Indexed: 12/19/2022]
Abstract
Atractaspis snake species are enigmatic in their natural history, and venom effects are correspondingly poorly described. Clinical reports are scarce but bites have been described as causing severe hypertension, profound local tissue damage leading to amputation, and deaths are on record. Clinical descriptions have largely concentrated upon tissue effects, and research efforts have focused upon the blood-pressure affecting sarafotoxins. However, coagulation disturbances suggestive of procoagulant functions have been reported in some clinical cases, yet this aspect has been uninvestigated. We used a suite of assays to investigate the coagulotoxic effects of venoms from six different Atractaspis specimens from central Africa. The procoagulant function of factor X activation was revealed, as was the pseudo-procoagulant function of direct cleavage of fibrinogen into weak clots. The relative neutralization efficacy of South African Antivenom Producer's antivenoms on Atractaspis venoms was boomslang>>>polyvalent>saw-scaled viper. While the boomslang antivenom was the most effective on Atractaspis venoms, the ability to neutralize the most potent Atractaspis species in this study was up to 4-6 times less effective than boomslang antivenom neutralizes boomslang venom. Therefore, while these results suggest cross-reactivity of boomslang antivenom with the unexpectedly potent coagulotoxic effects of Atractaspis venoms, a considerable amount of this rare antivenom may be needed. This report thus reveals potent venom actions upon blood coagulation that may lead to severe clinical effects with limited management strategies.
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Affiliation(s)
- Brice Oulion
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - James S Dobson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Christina N Zdenek
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Kevin Arbuckle
- Department of Biosciences, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - Callum Lister
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Francisco C P Coimbra
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Bianca Op den Brouw
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Jordan Debono
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Aymeric Rogalski
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Aude Violette
- Alphabiotoxine Laboratory sprl, Barberie 15, 7911 Montroeul-au-bois, Belgium
| | - Rudy Fourmy
- Alphabiotoxine Laboratory sprl, Barberie 15, 7911 Montroeul-au-bois, Belgium
| | | | - Bryan G Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
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Dobson JS, Phillips R, Millington GWM. Oxford Handbook of Medical Dermatology, second edition, 2016. Clin Exp Dermatol 2017; 42:474-475. [PMID: 30917214 DOI: 10.1111/ced.13140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J S Dobson
- Department of Dermatology, Norfolk and Norwich University Hospital, Norwich Research Park, Norwich, NR4 7UY, UK
| | - R Phillips
- Department of Dermatology, Norfolk and Norwich University Hospital, Norwich Research Park, Norwich, NR4 7UY, UK
| | - G W M Millington
- Department of Dermatology, Norfolk and Norwich University Hospital, Norwich Research Park, Norwich, NR4 7UY, UK
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Baumann K, Casewell NR, Ali SA, Jackson TNW, Vetter I, Dobson JS, Cutmore SC, Nouwens A, Lavergne V, Fry BG. A ray of venom: Combined proteomic and transcriptomic investigation of fish venom composition using barb tissue from the blue-spotted stingray (Neotrygon kuhlii). J Proteomics 2014; 109:188-98. [PMID: 24946716 DOI: 10.1016/j.jprot.2014.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 06/05/2014] [Accepted: 06/09/2014] [Indexed: 11/18/2022]
Abstract
UNLABELLED Fish venoms remain almost completely unstudied despite the large number of species. In part this is due to the inherent nature of fish venoms, in that they are highly sensitive to heat, pH, lyophilisation, storage and repeated freeze-thawing. They are also heavily contaminated with mucus, which makes proteomic study difficult. Here we describe a novel protein-handling protocol to remove mucus contamination, utilising ammonium sulphate and acetone precipitation. We validated this approach using barb venom gland tissue protein extract from the blue-spotted stingray Neotrygon kuhlii. We analysed the protein extract using 1D and 2D gels with LC-MS/MS sequencing. Protein annotation was underpinned by a venom gland transcriptome. The composition of our N. kuhlii venom sample revealed a variety of protein types that are completely novel to animal venom systems. Notably, none of the detected proteins exhibited similarity to the few toxin components previously characterised from fish venoms, including those found in other stingrays. Putative venom toxins identified here included cystatin, peroxiredoxin and galectin. Our study represents the first combined survey of gene and protein composition from the venom apparatus of any fish and our novel protein handling method will aid the future characterisation of toxins from other unstudied venomous fish lineages. BIOLOGICAL SIGNIFICANCE These results show an efficient manner for removing mucus from fish venoms. These results are the first insights into the evolution of proteins present on stingrayvenom barbs.
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Affiliation(s)
- Kate Baumann
- Venom Evolution Laboratory, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia
| | - Nicholas R Casewell
- Venom Evolution Laboratory, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia; Alistair Reid Venom Research Unit, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; Molecular Ecology and Evolution Group, School of Biological Sciences, Bangor University, Bangor LL57 2UW, UK
| | - Syed A Ali
- Venom Evolution Laboratory, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia; HRJ Research Institute of Chemistry, International Centre for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi 75270, Pakistan
| | - Timothy N W Jackson
- Venom Evolution Laboratory, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia; Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia; School of Pharmacy, University of Queensland, St Lucia, Queensland 4072, Australia
| | - James S Dobson
- Venom Evolution Laboratory, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia
| | - Scott C Cutmore
- Venom Evolution Laboratory, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia
| | - Amanda Nouwens
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Qld 4072, Australia
| | - Vincent Lavergne
- Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Bryan G Fry
- Venom Evolution Laboratory, School of Biological Sciences, University of Queensland, St Lucia, Qld 4072, Australia; School of Pharmacy, University of Queensland, St Lucia, Queensland 4072, Australia
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Dobson JS, Davison PA. A new rapid test of contrast sensitivity function utilizing spatial bandwidth equalization. Invest Ophthalmol Vis Sci 1980; 19:213-7. [PMID: 7351356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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