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Kalita B, Utkin YN, Mukherjee AK. Current Insights in the Mechanisms of Cobra Venom Cytotoxins and Their Complexes in Inducing Toxicity: Implications in Antivenom Therapy. Toxins (Basel) 2022; 14:toxins14120839. [PMID: 36548736 PMCID: PMC9780984 DOI: 10.3390/toxins14120839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 12/02/2022] Open
Abstract
Cytotoxins (CTXs), an essential class of the non-enzymatic three-finger toxin family, are ubiquitously present in cobra venoms. These low-molecular-mass toxins, contributing to about 40 to 60% of the cobra venom proteome, play a significant role in cobra venom-induced toxicity, more prominently in dermonecrosis. Structurally, CTXs contain the conserved three-finger hydrophobic loops; however, they also exhibit a certain degree of structural diversity that dictates their biological activities. In their mechanism, CTXs mediate toxicity by affecting cell membrane structures and membrane-bound proteins and activating apoptotic and necrotic cell death pathways. Notably, some CTXs are also responsible for depolarizing neurons and heart muscle membranes, thereby contributing to the cardiac failure frequently observed in cobra-envenomed victims. Consequently, they are also known as cardiotoxins (CdTx). Studies have shown that cobra venom CTXs form cognate complexes with other components that potentiate the toxic effects of the venom's individual component. This review focuses on the pharmacological mechanism of cobra venom CTXs and their complexes, highlighting their significance in cobra venom-induced pathophysiology and toxicity. Furthermore, the potency of commercial antivenoms in reversing the adverse effects of cobra venom CTXs and their complexes in envenomed victims has also been discussed.
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Affiliation(s)
- Bhargab Kalita
- Amrita School of Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi 682041, India
| | - Yuri N. Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
| | - Ashis K. Mukherjee
- Institute of Advanced Study in Science and Technology, Guwahati 781035, India
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784028, India
- Correspondence:
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Averin AS, Nenov MN, Starkov VG, Tsetlin VI, Utkin YN. Effects of Cardiotoxins from Naja oxiana Cobra Venom on Rat Heart Muscle and Aorta: A Comparative Study of Toxin-Induced Contraction Mechanisms. Toxins (Basel) 2022; 14:88. [PMID: 35202116 PMCID: PMC8878657 DOI: 10.3390/toxins14020088] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/15/2022] [Accepted: 01/19/2022] [Indexed: 12/04/2022] Open
Abstract
Cardiotoxins (CaTxs) are a group of snake toxins that affect the cardiovascular system (CVS). Two types (S and P) of CaTxs are known, but the exact differences in the effects of these types on CVS have not been thoroughly studied. We investigated cellular mechanisms of action on CVS for Naja oxiana cobra CaTxs CTX-1 (S-type) and CTX-2 (P-type) focusing on the papillary muscle (PM) contractility and contraction of aortic rings (AR) supplemented by pharmacological analysis. It was found that CTX-1 and CTX-2 exerted dose-dependent effects manifested in PM contracture and AR contraction. CTX-2 impaired functions of PM and AR more strongly than CTX-1. Effects of CaTxs on PM were significantly reduced by nifedipine, an L-type Ca2+ channel blocker, and by KB-R7943, an inhibitor of reverse-mode Na+/Ca2+ exchange. Furthermore, 2-aminoethoxydiphenyl borate, an inhibitor of store-operated calcium entry, partially restored PM contractility damaged by CaTxs. The CaTx influence on AR contracture was significantly reduced by nifedipine and KB-R7943. The involvement of reverse-mode Na+/Ca2+ exchange in the effect of CaTxs on the rat aorta was shown for the first time. The results obtained indicate that CaTx effects on CVS are mainly associated with disturbance of transporting systems responsible for the Ca2+ influx.
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Affiliation(s)
- Alexey S. Averin
- Institute of Cell Biophysics of the Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center of Biological Research of the Russian Academy of Sciences”, 142290 Pushchino, Russia;
| | - Miroslav N. Nenov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, 142290 Pushchino, Russia;
| | - Vladislav G. Starkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (V.G.S.); (V.I.T.)
| | - Victor I. Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (V.G.S.); (V.I.T.)
| | - Yuri N. Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (V.G.S.); (V.I.T.)
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Averin AS, Utkin YN. Cardiovascular Effects of Snake Toxins: Cardiotoxicity and Cardioprotection. Acta Naturae 2021; 13:4-14. [PMID: 34707893 PMCID: PMC8526186 DOI: 10.32607/actanaturae.11375] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/13/2021] [Indexed: 12/11/2022] Open
Abstract
Snake venoms, as complex mixtures of peptides and proteins, affect various vital systems of the organism. One of the main targets of the toxic components from snake venoms is the cardiovascular system. Venom proteins and peptides can act in different ways, exhibiting either cardiotoxic or cardioprotective effects. The principal classes of these compounds are cobra cardiotoxins, phospholipases A2, and natriuretic, as well as bradykinin-potentiating peptides. There is another group of proteins capable of enhancing angiogenesis, which include, e.g., vascular endothelial growth factors possessing hypotensive and cardioprotective activities. Venom proteins and peptides exhibiting cardiotropic and vasoactive effects are promising candidates for the design of new drugs capable of preventing or constricting the development of pathological processes in cardiovascular diseases, which are currently the leading cause of death worldwide. For example, a bradykinin-potentiating peptide from Bothrops jararaca snake venom was the first snake venom compound used to create the widely used antihypertensive drugs captopril and enalapril. In this paper, we review the current state of research on snake venom components affecting the cardiovascular system and analyse the mechanisms of physiological action of these toxins and the prospects for their medical application.
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Affiliation(s)
- A. S. Averin
- Institute of Cell Biophysics of the Russian Academy of Sciences PSCBR RAS, Pushchino, Moscow region, 142290 Russia
| | - Yu. N. Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997 Russia
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Wong KY, Tan KY, Tan NH, Tan CH. A Neurotoxic Snake Venom without Phospholipase A 2: Proteomics and Cross-Neutralization of the Venom from Senegalese Cobra, Naja senegalensis (Subgenus: Uraeus). Toxins (Basel) 2021; 13:toxins13010060. [PMID: 33466660 PMCID: PMC7828783 DOI: 10.3390/toxins13010060] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/22/2020] [Accepted: 01/07/2021] [Indexed: 11/16/2022] Open
Abstract
The Senegalese cobra, Naja senegalensis, is a non-spitting cobra species newly erected from the Naja haje complex. Naja senegalensis causes neurotoxic envenomation in Western Africa but its venom properties remain underexplored. Applying a protein decomplexation proteomic approach, this study unveiled the unique complexity of the venom composition. Three-finger toxins constituted the major component, accounting for 75.91% of total venom proteins. Of these, cardiotoxin/cytotoxin (~53%) and alpha-neurotoxins (~23%) predominated in the venom proteome. Phospholipase A2, however, was not present in the venom, suggesting a unique snake venom phenotype found in this species. The venom, despite the absence of PLA2, is highly lethal with an intravenous LD50 of 0.39 µg/g in mice, consistent with the high abundance of alpha-neurotoxins (predominating long neurotoxins) in the venom. The hetero-specific VINS African Polyvalent Antivenom (VAPAV) was immunoreactive to the venom, implying conserved protein antigenicity in the venoms of N. senegalensis and N. haje. Furthermore, VAPAV was able to cross-neutralize the lethal effect of N. senegalensis venom but the potency was limited (0.59 mg venom completely neutralized per mL antivenom, or ~82 LD50 per ml of antivenom). The efficacy of antivenom should be further improved to optimize the treatment of cobra bite envenomation in Africa.
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Affiliation(s)
- Kin Ying Wong
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
| | - Kae Yi Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; (K.Y.T.); (N.H.T.)
| | - Nget Hong Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; (K.Y.T.); (N.H.T.)
| | - Choo Hock Tan
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia;
- Correspondence: ; Tel.: +60-3-7967-6685
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Averin AS, Astashev ME, Andreeva TV, Tsetlin VI, Utkin YN. Cardiotoxins from Cobra Naja oxiana Change the Force of Contraction and the Character of Rhythmoinotropic Phenomena in the Rat Myocardium. DOKL BIOCHEM BIOPHYS 2019; 487:282-286. [PMID: 31559598 DOI: 10.1134/s1607672919040094] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Indexed: 01/03/2023]
Abstract
The study of the influence of cobra Naja oxiana cardiotoxins on the contractility of the rat papillary muscles and its rhythmoinotropic characteristics has shown that the presence of toxins induces a slight contractility decrease in the stimulation frequency range up to 0.1 Hz. In the stimulation frequency range from 0.1 to 0.5 Hz, a positive inotropic effect is found. However, the positive inotropic effect is replaced by a negative one with further increase in the frequency up to 3 Hz. In the presence of cardiotoxins, the positive force-frequency relationship in the region of 1-3 Hz, characteristic of healthy rat myocardium, disappears and the relationship becomes completely negative. L-type calcium channel blocker nifedipine does not affect the changes induced by toxins, while a high concentration (10 mM) of calcium prevents the effects of cardiotoxins on the muscle. The results obtained show that the impairment of the force-frequency relationship occurs long before the development of irreversible damage in the myocardium and may be the first sign of the pathological action of cardiotoxins.
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Affiliation(s)
- A S Averin
- Institute of Cell Biophysics, Federal Research Center "Pushchino Scientific Center of Biological Research," Pushchino Branch, Russian Academy of Sciences, 142290, Pushchino, Moscow oblast, Russia.
| | - M E Astashev
- Institute of Cell Biophysics, Federal Research Center "Pushchino Scientific Center of Biological Research," Pushchino Branch, Russian Academy of Sciences, 142290, Pushchino, Moscow oblast, Russia
| | - T V Andreeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997, Moscow, Russia
| | - V I Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997, Moscow, Russia
| | - Yu N Utkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997, Moscow, Russia.
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Nguyen TTN, Folch B, Létourneau M, Vaudry D, Truong NH, Doucet N, Chatenet D, Fournier A. Cardiotoxin-I: an unexpectedly potent insulinotropic agent. Chembiochem 2012; 13:1805-12. [PMID: 22807058 DOI: 10.1002/cbic.201200081] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Indexed: 12/17/2022]
Abstract
Insulin secretion from pancreatic β-cells is a complex process, involving the integration and interaction of multiple external and internal stimuli, in which glucose plays a major role. Understanding the physiology leading to insulin release is a crucial step toward the identification of new targets. In this study, we evaluated the presence of insulinotropic metabolites in Naja kaouthia snake venom. Only one fraction, identified as cardiotoxin-I (CTX-I) was able to induce insulin secretion from INS-1E cells without affecting cell viability and integrity, as assessed by MTT and LDH assays. Interestingly, CTX-I was also able to stimulate insulin secretion from INS-1E cells even in the absence of glucose. Although cardiotoxins have been characterized as potent hemolytic agents and vasoconstrictors, CTX-I was unable to induce direct hemolysis of human erythrocytes or to induce potent vasoconstriction. As such, this newly identified insulin-releasing toxin will surely enrich the pool of existing tools to study β-cell physiology or even open a new therapeutic avenue.
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Affiliation(s)
- Thi Tuyet Nhung Nguyen
- INRS-Institut Armand-Frappier, Université du Québec, 531 Boulevard des Prairies, Ville de Laval, Québec H7V 1B7, Canada
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Lin YL, Lin SR, Wu TT, Chang LS. Evidence showing an intermolecular interaction between KChIP proteins and Taiwan cobra cardiotoxins. Biochem Biophys Res Commun 2004; 319:720-4. [PMID: 15184042 DOI: 10.1016/j.bbrc.2004.05.064] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2004] [Indexed: 10/26/2022]
Abstract
Direct protein-protein interaction between Taiwan cobra cardiotoxin3 (CTX3) and potassium channel-interacting proteins (KChIPs) was investigated in the present study. It was found that KChIPs bound with CTX3, in which KChIP and CTX3 formed a 1:1 complex as evidenced by the results of chemical cross-linking. Pull-down assay revealed that the intact EF-hands 3 and 4 of KChIP1 were critical for CTX3-binding. Likewise, removal of EF-hands 3 and 4 distorted the ability of KChIP1 to bind with Kv4.2 N-terminal fragment (KvN) as well as fluorescent probe 8-anilinonaphthalene-1-sulfonate (ANS). In contrast to the interaction between KChIP1 and KvN, the binding of CTX3 to KChIP1 showed a Ca(2+)-independent manner. Fluorescence measurement revealed that CTX3 affected the binding of ANS to Ca(2+)-bound KChIP1, but not Ca(2+)-free KChIP1. Alternatively, KChIP1 simultaneously bound with KvN and CTX3, and the interaction between KChIP1 and KvN was enhanced by CTX3. In terms of the fact that KChIPs regulate the electrophysiological properties of Kv K(+) channel, the potentiality of CTX for this biomedical application could be considered.
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Affiliation(s)
- Ya-Ling Lin
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, ROC
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Kwan VSY, John OP, Kenny DA, Bond MH, Robins RW. Reconceptualizing Individual Differences in Self-Enhancement Bias: An Interpersonal Approach. Psychol Rev 2004; 111:94-110. [PMID: 14756588 DOI: 10.1037/0033-295x.111.1.94] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Self-enhancement bias has been studied from 2 perspectives: L. Festinger's (1954) social comparison theory (self-enhancers perceive themselves more positively than they perceive others) and G. W. Allport's (1937) self-insight theory (self-enhancers perceive themselves more positively than they are perceived by others). These 2 perspectives are theoretically and empirically distinct, and the failure to recognize their differences has led to a protracted debate. A new interpersonal approach to self-enhancement decomposes self-perception into 3 components: perceiver effect, target effect, and unique self-perception. Both theoretical derivations and an illustrative study suggest that this resulting measure of self-enhancement is less confounded by unwanted components of interpersonal perception than previous social comparison and self-insight measures. Findings help reconcile conflicting views about whether self-enhancement is adaptive or maladaptive.
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Affiliation(s)
- Virginia S Y Kwan
- Department of Psychology, Princeton University, Princeton, NJ 08544-1010, USA.
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