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Vuong NT, Jackson TNW, Wright CE. Role of Phospholipases A 2 in Vascular Relaxation and Sympatholytic Effects of Five Australian Brown Snake, Pseudonaja spp., Venoms in Rat Isolated Tissues. Front Pharmacol 2021; 12:754304. [PMID: 34744732 PMCID: PMC8566954 DOI: 10.3389/fphar.2021.754304] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/11/2021] [Indexed: 11/13/2022] Open
Abstract
Human envenoming by Australian brown snakes (Pseudonaja spp.) may result in potentially life-threatening hypotension and subsequent cardiovascular collapse. There have been relatively few studies of the cardiovascular and sympathetic effects of Pseudonaja spp. venoms. In this study, we have examined the effects of venom from five brown snake species-P. affinis, aspidorhyncha, inframacula, nuchalis, and textilis-on cardiac inotropic and chronotropic responses, vascular tone, and sympathetic nerve-induced vascular contractions in rat isolated tissues. The role of phospholipases A2 (PLA2s) in venom-induced effects was assessed with the sPLA2 inhibitor varespladib. In rat isolated left and right atria, there were no physiologically relevant effects of Pseudonaja venoms (0.1-30 µg/ml) on left atrial force of contraction (inotropy) or right atrial rate (chronotropy). In contrast, in isolated small mesenteric arteries precontracted with a thromboxane mimetic, each of the five brown snake venoms (at 30 µg/ml) caused marked vasorelaxation (-60 to -90% of contractile tone). Pretreatment with varespladib (1 µM) significantly inhibited the vasorelaxation caused by P. aspidorhyncha, P. nuchalis, and P. textilis venoms. Electrically induced sympathetic nerve-mediated contractions of mesenteric arteries were significantly attenuated by only P. textilis, and P. affinis venoms (30 µg/ml) and these sympatholytic effects were inhibited by varespladib (1 µM). Based on their inhibition with the sPLA2 inhibitor varespladib, we conclude that PLA2 toxins in P. aspidorhyncha, P. nuchalis, and P. textilis venoms are involved in brown snake venom-induced vasorelaxation and the sympatholytic effects of P. affinis, and P. textilis venoms. Our study supports the promising potential role of varespladib as an initial (pre-referral) and/or adjunct (in combination with antivenom) therapeutic agent for brown snake envenoming.
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Affiliation(s)
- Nhi Thuc Vuong
- Cardiovascular Therapeutics Unit, Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC, Australia
| | - Timothy N. W. Jackson
- Australian Venom Research Unit, Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC, Australia
| | - Christine E. Wright
- Cardiovascular Therapeutics Unit, Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC, Australia
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2
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Cao Y, Yu C, Huang S, Wang S, Zuo Y, Yang L. Characterization and Prediction of Presynaptic and Postsynaptic Neurotoxins Based on Reduced Amino Acids and Biological Properties. Curr Bioinform 2021. [DOI: 10.2174/1574893615999200707150512] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Presynaptic and postsynaptic neurotoxins are two important neurotoxins. Due to the important
role of presynaptic and postsynaptic neurotoxins in pharmacology and neuroscience, identification of them becomes very
important in biology.
Method:
In this study, the statistical test and F-score were used to calculate the difference between amino acids and
biological properties. The support vector machine was used to predict the presynaptic and postsynaptic neurotoxins by
using the reduced amino acid alphabet types.
Results:
By using the reduced amino acid alphabet as the input parameters of support vector machine, the overall accuracy
of our classifier had increased to 91.07%, which was the highest overall accuracy in this study. When compared with the
other published methods, better predictive results were obtained by our classifier.
Conclusion:
In summary, we analyzed the differences between two neurotoxins in amino acids and biological properties,
and constructed a classifier that could predict these two neurotoxins by using the reduced amino acid alphabet.
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Affiliation(s)
- Yiyin Cao
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin 150081, China
| | - Chunlu Yu
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin 150081, China
| | - Shenghui Huang
- The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, College of Life Sciences, Inner Mongolia University, Hohhot, 010070, China
| | - Shiyuan Wang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin 150081, China
| | - Yongchun Zuo
- The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, College of Life Sciences, Inner Mongolia University, Hohhot, 010070, China
| | - Lei Yang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin 150081, China
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3
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Gutiérrez JM, Vargas M, Segura Á, Herrera M, Villalta M, Solano G, Sánchez A, Herrera C, León G. In Vitro Tests for Assessing the Neutralizing Ability of Snake Antivenoms: Toward the 3Rs Principles. Front Immunol 2021; 11:617429. [PMID: 33505403 PMCID: PMC7829219 DOI: 10.3389/fimmu.2020.617429] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/23/2020] [Indexed: 12/24/2022] Open
Abstract
There is an urgent need to strengthen the implementation of the 3Rs principle (Replacement, Reduction and Refinement) in the use of experimental animals in toxinological research and in the assessment of the neutralizing efficacy of snake antivenoms. This is a challenging task owing to the inherent complexity of snake venoms. The state of the art on this topic is hereby reviewed, with emphasis on the studies in which a correlation has been observed between in vivo toxicity tests and in vitro surrogate assays, particularly in the study of lethal activity of venoms and its neutralization. Correlations have been described with some venoms-antivenoms when using: (a) enzyme immunoassays, (b) hemagglutination, (c) enzyme assays (proteinase, phospholipase A2), (d) in vitro coagulant effect on plasma, (e) cell culture assays for cytotoxicity, (f) functional assays for assessing neurotoxicity in vitro, (g) use of hens' eggs, and (h) antivenomics. Additionally, the routine introduction of analgesia in these assays and the design of more 'humane' protocols for the lethality test are being pursued. It is expected that the next years will witness a growing awareness of the relevance of the 3Rs principles in antivenom testing, and that new in vitro alternatives and more 'humane' experimental designs will emerge in this field.
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Affiliation(s)
| | - Mariángela Vargas
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
| | - Álvaro Segura
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
| | - María Herrera
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
| | - Mauren Villalta
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
| | - Gabriela Solano
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
| | - Andrés Sánchez
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
| | - Cristina Herrera
- Facultad de Farmacia, Universidad de Costa Rica, San José, Costa Rica
| | - Guillermo León
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
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4
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Antibiofilm Activity of Acidic Phospholipase Isoform Isolated from Bothrops erythromelas Snake Venom. Toxins (Basel) 2020; 12:toxins12090606. [PMID: 32962193 PMCID: PMC7551604 DOI: 10.3390/toxins12090606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/27/2020] [Accepted: 08/07/2020] [Indexed: 11/22/2022] Open
Abstract
Introduction: Bacterial resistance is a worldwide public health problem, requiring new therapeutic options. An alternative approach to this problem is the use of animal toxins isolated from snake venom, such as phospholipases A2 (PLA2), which have important antimicrobial activities. Bothropserythromelas is one of the snake species in the northeast of Brazil that attracts great medical-scientific interest. Here, we aimed to purify and characterize a PLA2 from B. erythromelas, searching for heterologous activities against bacterial biofilms. Methods: Venom extraction and quantification were followed by reverse-phase high-performance liquid chromatography (RP-HPLC) in C18 column, matrix-assisted ionization time-of-flight (MALDI-ToF) mass spectrometry, and sequencing by Edman degradation. All experiments were monitored by specific activity using a 4-nitro-3-(octanoyloxy) benzoic acid (4N3OBA) substrate. In addition, hemolytic tests and antibacterial tests including action against Escherichiacoli, Staphylococcusaureus, and Acinetobacterbaumannii were carried out. Moreover, tests of antibiofilm action against A. baumannii were also performed. Results: PLA2, after one purification step, presented 31 N-terminal amino acid residues and a molecular weight of 13.6564 Da, with enzymatic activity confirmed in 0.06 µM concentration. Antibacterial activity against S. aureus (IC50 = 30.2 µM) and antibiofilm activity against A. baumannii (IC50 = 1.1 µM) were observed. Conclusions: This is the first time that PLA2 purified from B. erythromelas venom has appeared as an alternative candidate in studies of new antibacterial medicines.
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Fontana Oliveira IC, Gutiérrez JM, Lewin MR, Oshima-Franco Y. Varespladib (LY315920) inhibits neuromuscular blockade induced by Oxyuranus scutellatus venom in a nerve-muscle preparation. Toxicon 2020; 187:101-104. [PMID: 32889027 DOI: 10.1016/j.toxicon.2020.08.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/08/2020] [Accepted: 08/30/2020] [Indexed: 11/28/2022]
Abstract
The phospholipase A2 (PLA2) inhibitors varespladib (LY315920) and its orally available derivative methyl-varespladib (LY333013) have been proposed as potential therapies for the treatment of snakebite envenomings in which toxicity depends on the action of PLA2s. In this study, the ability of LY315920 to abrogate the effect of the potent neurotoxic venom of Oxyuranus scutellatus (taipan) was assessed using the mouse phrenic nerve-diaphragm preparation. LY315920 inhibited the venom when (a) incubated with venom before addition to the medium; (b) added to the medium before addition of venom, and; (c) added to the medium within 30 min after addition of venom, and even after the onset of decline in twitch response. This contrasts with previous results with antivenom using the same experimental model, in which the window of time when antibodies are effective is shorter than 10 min. It is proposed that such differences may depend either on the higher affinity of the inhibitor for PLA2s or on the possibility that LY315920 reaches the cytosol of the nerve terminals, inhibiting neurotoxins that have been internalized. Our findings bear implications on the therapeutic potential of varespladib in neurotoxic snakebite envenomings mediated by presynaptically-acting PLA2s.
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Affiliation(s)
- Isadora Caruso Fontana Oliveira
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Rodovia Raposo Tavares Km 92.5, 18023-000, Sorocaba, SP, Brazil
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Matthew R Lewin
- California Academy of Sciences, San Francisco, CA, 94118, USA; Ophirex, Inc., Corte Madera, CA, 94925, USA
| | - Yoko Oshima-Franco
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Rodovia Raposo Tavares Km 92.5, 18023-000, Sorocaba, SP, Brazil.
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6
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Vindas J, Carrera Y, Lomonte B, Gutiérrez JM, Calvete JJ, Sanz L, Fernández J. A novel pentameric phospholipase A2 myotoxin (PophPLA2) from the venom of the pit viper Porthidium ophryomegas. Int J Biol Macromol 2018; 118:1-8. [DOI: 10.1016/j.ijbiomac.2018.06.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 06/03/2018] [Accepted: 06/06/2018] [Indexed: 01/07/2023]
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7
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Vulfius CA, Kasheverov IE, Kryukova EV, Spirova EN, Shelukhina IV, Starkov VG, Andreeva TV, Faure G, Zouridakis M, Tsetlin VI, Utkin YN. Pancreatic and snake venom presynaptically active phospholipases A2 inhibit nicotinic acetylcholine receptors. PLoS One 2017; 12:e0186206. [PMID: 29023569 PMCID: PMC5638340 DOI: 10.1371/journal.pone.0186206] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 09/27/2017] [Indexed: 01/08/2023] Open
Abstract
Phospholipases A2 (PLA2s) are enzymes found throughout the animal kingdom. They hydrolyze phospholipids in the sn-2 position producing lysophospholipids and unsaturated fatty acids, agents that can damage membranes. PLA2s from snake venoms have numerous toxic effects, not all of which can be explained by phospholipid hydrolysis, and each enzyme has a specific effect. We have earlier demonstrated the capability of several snake venom PLA2s with different enzymatic, cytotoxic, anticoagulant and antiproliferative properties, to decrease acetylcholine-induced currents in Lymnaea stagnalis neurons, and to compete with α-bungarotoxin for binding to nicotinic acetylcholine receptors (nAChRs) and acetylcholine binding protein. Since nAChRs are implicated in postsynaptic and presynaptic activities, in this work we probe those PLA2s known to have strong presynaptic effects, namely β-bungarotoxin from Bungarus multicinctus and crotoxin from Crotalus durissus terrificus. We also wished to explore whether mammalian PLA2s interact with nAChRs, and have examined non-toxic PLA2 from porcine pancreas. It was found that porcine pancreatic PLA2 and presynaptic β-bungarotoxin blocked currents mediated by nAChRs in Lymnaea neurons with IC50s of 2.5 and 4.8 μM, respectively. Crotoxin competed with radioactive α-bungarotoxin for binding to Torpedo and human α7 nAChRs and to the acetylcholine binding protein. Pancreatic PLA2 interacted similarly with these targets; moreover, it inhibited radioactive α-bungarotoxin binding to the water-soluble extracellular domain of human α9 nAChR, and blocked acetylcholine induced currents in human α9α10 nAChRs heterologously expressed in Xenopus oocytes. These and our earlier results show that all snake PLA2s, including presynaptically active crotoxin and β-bungarotoxin, as well as mammalian pancreatic PLA2, interact with nAChRs. The data obtained suggest that this interaction may be a general property of all PLA2s, which should be proved by further experiments.
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Affiliation(s)
- Catherine A. Vulfius
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Igor E. Kasheverov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Elena V. Kryukova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Ekaterina N. Spirova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Irina V. Shelukhina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Vladislav G. Starkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Tatyana V. Andreeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Grazyna Faure
- Unité Récepteurs-Canaux, Institut Pasteur, Paris, France
| | | | - Victor I. Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Yuri N. Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- * E-mail:
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8
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Huo H, Li T, Wang S, Lv Y, Zuo Y, Yang L. Prediction of presynaptic and postsynaptic neurotoxins by combining various Chou's pseudo components. Sci Rep 2017; 7:5827. [PMID: 28724993 PMCID: PMC5517432 DOI: 10.1038/s41598-017-06195-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 06/08/2017] [Indexed: 11/09/2022] Open
Abstract
Presynaptic and postsynaptic neurotoxins are two groups of neurotoxins. Identification of presynaptic and postsynaptic neurotoxins is an important work for numerous newly found toxins. It is both costly and time consuming to determine these two neurotoxins by experimental methods. As a complement, using computational methods for predicting presynaptic and postsynaptic neurotoxins could provide some useful information in a timely manner. In this study, we described four algorithms for predicting presynaptic and postsynaptic neurotoxins from sequence driven features by using Increment of Diversity (ID), Multinomial Naive Bayes Classifier (MNBC), Random Forest (RF), and K-nearest Neighbours Classifier (IBK). Each protein sequence was encoded by pseudo amino acid (PseAA) compositions and three biological motif features, including MEME, Prosite and InterPro motif features. The Maximum Relevance Minimum Redundancy (MRMR) feature selection method was used to rank the PseAA compositions and the 50 top ranked features were selected to improve the prediction accuracy. The PseAA compositions and three kinds of biological motif features were combined and 12 different parameters that defined as P1-P12 were selected as the input parameters of ID, MNBC, RF, and IBK. The prediction results obtained in this study were significantly better than those of previously developed methods.
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Affiliation(s)
- Haiyan Huo
- Department of Environmental Engineering, Hohhot University for Nationalities, Hohhot, 010051, China
| | - Tao Li
- College of Life Science, Inner Mongolia Agricultural University, Hohhot, 010018, China
| | - Shiyuan Wang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, 150081, China
| | - Yingli Lv
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, 150081, China
| | - Yongchun Zuo
- The Key Laboratory of Mammalian Reproductive Biology and Biotechnology of the Ministry of Education, Inner Mongolia University, Hohhot, 010021, China.
| | - Lei Yang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, 150081, China.
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9
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Šribar J, Oberčkal J, Križaj I. Understanding the molecular mechanism underlying the presynaptic toxicity of secreted phospholipases A2: An update. Toxicon 2014; 89:9-16. [DOI: 10.1016/j.toxicon.2014.06.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 06/19/2014] [Accepted: 06/24/2014] [Indexed: 11/16/2022]
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10
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Schurch B, Carda S. OnabotulinumtoxinA and multiple sclerosis. Ann Phys Rehabil Med 2014; 57:302-314. [PMID: 24953702 DOI: 10.1016/j.rehab.2014.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 05/19/2014] [Indexed: 10/25/2022]
Abstract
Lower urinary tract dysfunction is present in two of three patients with multiple sclerosis five years after the diagnosis. Most frequent symptoms are related to neurogenic detrusor overactivity, often associated with detrusor-sphincter dyssynergia. From the end of the 1990s, there is growing evidence that neurogenic detrusor overactivity can be effectively managed by intradetrusorial injections of botulinum toxin type A. This treatment has shown, in different randomised placebo-controlled trials, to be safe and effective on clinical and urodynamic parameters with significant improvement in quality of life. The median duration of effect is in mean nine months. The vast majority of studies have been conducted with onabotulinumtoxinA. The dose of onabotulinumtoxinA commonly used to treat neurogenic detrusor overactivity in patients with multiple sclerosis is 200 UI, even if in selected patients lower doses can be preferred. To be considered eligible for treatment, all patients should accept and be instructed to perform clean intermittent self-catheterisation, since the risk of increased post-void residual volume and/or urinary retention after injection is high, especially with 200 UI of onabotulinumtoxinA. However, quality of life and patient satisfaction seem not to be affected by the need of intermittent catheterisation. The risk of urinary infection after the procedure is to be kept in mind, mainly in patients with multiple sclerosis, so that adequate antibiotic prophylaxis is highly recommended.
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Affiliation(s)
- B Schurch
- Neurourology, Service of Physical Medicine and Neurorehabilitation, CHU Vaudois, 5, avenue Pierre-Decker, 1011 Lausanne, Switzerland
| | - S Carda
- Neurourology, Service of Physical Medicine and Neurorehabilitation, CHU Vaudois, 5, avenue Pierre-Decker, 1011 Lausanne, Switzerland.
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11
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Kuruppu S, Chaisakul J, Smith AI, Hodgson WC. Inhibition of presynaptic neurotoxins in taipan venom by suramin. Neurotox Res 2013; 25:305-10. [PMID: 24129771 DOI: 10.1007/s12640-013-9426-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 09/18/2013] [Accepted: 09/23/2013] [Indexed: 11/30/2022]
Abstract
Taipans are amongst the most venomous snakes in the world, and neurotoxicity is a major life-threatening symptom of envenoming by these snakes. Three species of taipans exist, and the venom from each species contains a presynaptic neurotoxin which accounts for much of the neurotoxicity observed following human envenoming. The high cost of antivenom used to treat neurotoxicity has resulted in the need to develop alternative but effective therapies. Therefore, in this study, we examined the ability of the P2Y receptor antagonist suramin to prevent the in vitro neurotoxic effects of the three presynaptic neurotoxins in taipan venoms: taipoxin, paradoxin and cannitoxin. Toxins were purchased from commercial sources or purified in house, using multiple steps of gel filtration chromatography. All three toxins (11 nM) inhibited nerve-mediated twitches in the chick biventer cervicis nerve-muscle preparation within 300 min. The presence of suramin (0.3 mM) completely blocked the taipoxin and cannitoxin-mediated inhibition of nerve-mediated twitches within the course of the experiment (P < 0.0001). However, paradoxin induced a 32 % decrease in twitch height even in the presence of suramin within 360 min. This was significantly different compared to toxin alone (P < 0.0001). We also examined the effect of suramin on the neurotoxic effects of textilotoxin and the products of phospholipase A2 action. Each toxin alone or in the presence of suramin failed to inhibit the responses to exogenous agonists ACh, CCh or KCl. Our results warrant clinical studies aimed determining the efficacy of suramin in preventing the onset of neurotoxicity following taipan envenoming.
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Affiliation(s)
- Sanjaya Kuruppu
- Department of Biochemistry & Molecular Biology, Monash University, Building 77, Clayton, VIC, 3800, Australia,
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12
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Proteomic characterisation of toxins isolated from nematocysts of the South Atlantic jellyfish Olindias sambaquiensis. Toxicon 2013; 71:11-7. [PMID: 23688393 DOI: 10.1016/j.toxicon.2013.05.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/24/2013] [Accepted: 05/01/2013] [Indexed: 11/21/2022]
Abstract
Surprisingly little is known of the toxic arsenal of cnidarian nematocysts compared to other venomous animals. Here we investigate the toxins of nematocysts isolated from the jellyfish Olindias sambaquiensis. A total of 29 unique ms/ms events were annotated as potential toxins homologous to the toxic proteins from diverse animal phyla, including cone-snails, snakes, spiders, scorpions, wasp, bee, parasitic worm and other Cnidaria. Biological activities of these potential toxins include cytolysins, neurotoxins, phospholipases and toxic peptidases. The presence of several toxic enzymes is intriguing, such as sphingomyelin phosphodiesterase B (SMase B) that has only been described in certain spider venoms, and a prepro-haystatin P-IIId snake venom metalloproteinase (SVMP) that activates coagulation factor X, which is very rare even in snake venoms. Our annotation reveals sequence orthologs to many representatives of the most important superfamilies of peptide venoms suggesting that their origins in higher organisms arise from deep eumetazoan innovations. Accordingly, cnidarian venoms may possess unique biological properties that might generate new leads in the discovery of novel pharmacologically active drugs.
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13
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Torres MCM, das Chagas L Pinto F, Braz-Filho R, Silveira ER, Pessoa ODL, Jorge RJB, Ximenes RM, Monteiro HSA, Monteiro Evangelista JSA, Diz-Filho EBS, Toyama MH. Antiophidic solanidane steroidal alkaloids from Solanum campaniforme. JOURNAL OF NATURAL PRODUCTS 2011; 74:2168-2173. [PMID: 21962208 DOI: 10.1021/np200479a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Three new solanidane alkaloids bearing a 22,23-epoxy ring (1-3) and four known compounds were isolated from leaves of Solanum campaniforme. The structures were determined using spectroscopic techniques, including 1D and 2D NMR, and HRESIMS experiments. The antiophidic activity of the alkaloids was tested against Bothrops pauloensis venom. Compounds 1-3 completely inhibited myotoxicity without inhibiting phospholipase A2 activity of the venom, while hemorrhage and skin necrosis were significantly reduced in the presence of alkaloids 1 and 2.
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Affiliation(s)
- Maria Conceição M Torres
- Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, 12.200, Fortaleza-CE, 60.021-970, Brazil
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14
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Dolly JO, Wang J, Zurawski TH, Meng J. Novel therapeutics based on recombinant botulinum neurotoxins to normalize the release of transmitters and pain mediators. FEBS J 2011; 278:4454-66. [DOI: 10.1111/j.1742-4658.2011.08205.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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SNARE tagging allows stepwise assembly of a multimodular medicinal toxin. Proc Natl Acad Sci U S A 2010; 107:18197-201. [PMID: 20921391 DOI: 10.1073/pnas.1007125107] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Generation of supramolecular architectures through controlled linking of suitable building blocks can offer new perspectives to medicine and applied technologies. Current linking strategies often rely on chemical methods that have limitations and cannot take full advantage of the recombinant technologies. Here we used SNARE proteins, namely, syntaxin, SNAP25, and synaptobrevin, which form stable tetrahelical complexes that drive fusion of intracellular membranes, as versatile tags for irreversible linking of recombinant and synthetic functional units. We show that SNARE tagging allows stepwise production of a functional modular medicinal toxin, namely, botulinum neurotoxin type A, commonly known as BOTOX. This toxin consists of three structurally independent units: Receptor-binding domain (Rbd), Translocation domain (Td), and the Light chain (Lc), the last being a proteolytic enzyme. Fusing the receptor-binding domain with synaptobrevin SNARE motif allowed delivery of the active part of botulinum neurotoxin (Lc-Td), tagged with SNAP25, into neurons. Our data show that SNARE-tagged toxin was able to cleave its intraneuronal molecular target and to inhibit release of neurotransmitters. The reassembled toxin provides a safer alternative to existing botulinum neurotoxin and may offer wider use of this popular research and medical tool. Finally, SNARE tagging allowed the Rbd portion of the toxin to be used to deliver quantum dots and other fluorescent markers into neurons, showing versatility of this unique tagging and self-assembly technique. Together, these results demonstrate that the SNARE tetrahelical coiled-coil allows controlled linking of various building blocks into multifunctional assemblies.
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Characterisation of the heterotrimeric presynaptic phospholipase A(2) neurotoxin complex from the venom of the common death adder (Acanthophis antarcticus). Biochem Pharmacol 2010; 80:277-87. [PMID: 20361942 DOI: 10.1016/j.bcp.2010.03.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 03/16/2010] [Accepted: 03/24/2010] [Indexed: 11/23/2022]
Abstract
While Australo-Papuan death adder neurotoxicity is generally considered to be due to the actions of reversible competitive postsynaptic alpha-neurotoxins, the neurotoxic effects are often poorly reversed by antivenom or anticholinesterases. This suggests that the venom may contain a snake presynaptic phospholipase A(2) (PLA(2)) neurotoxin (SPAN) that binds irreversibly to motor nerve terminals to inhibit neurotransmitter release. Using size-exclusion liquid chromatography under non-reducing conditions, we report the isolation and characterisation of a high molecular mass SPAN complex, P-elapitoxin-Aa1a (P-EPTX-Aa1a), from the venom of the common death adder Acanthophis antarcticus. Using the chick biventer-cervicis nerve-muscle preparation, P-EPTX-Aa1a (44,698Da) caused inhibition of nerve-evoked twitch contractions while responses to cholinergic agonists and KCl remained unaffected. P-EPTX-Aa1a also produced significant fade in tetanic contractions and a triphasic timecourse of neuromuscular blockade. These actions are consistent with other SPANs that inhibit acetylcholine release. P-EPTX-Aa1a was found to be a heterotrimeric complex composed of alpha, beta and gamma-subunits in a 1:1:1 stoichiometry with each subunit showing significant N-terminal sequence homology to the subunits of taipoxin, a SPAN from Oxyuranus s. scutellatus. Like taipoxin, only the alpha-chain produced any signs of neurotoxicity or displayed significant PLA(2) enzymatic activity. Preincubation with monovalent death adder antivenom or suramin, or inhibition of PLA(2) activity by incubation with 4-bromophenacyl bromide, either prevented or significantly delayed the onset of toxicity by P-EPTX-Aa1a. However, antivenom failed to reverse neurotoxicity. Early intervention with antivenom may therefore be important in severe cases of envenomation by A. antarcticus, given the presence of potent irreversible presynaptic neurotoxins.
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