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Urra FA, Vivas-Ruiz DE, Sanchez EF, Araya-Maturana R. An Emergent Role for Mitochondrial Bioenergetics in the Action of Snake Venom Toxins on Cancer Cells. Front Oncol 2022; 12:938749. [PMID: 35924151 PMCID: PMC9343075 DOI: 10.3389/fonc.2022.938749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 06/14/2022] [Indexed: 01/09/2023] Open
Abstract
Beyond the role of mitochondria in apoptosis initiation/execution, some mitochondrial adaptations support the metastasis and chemoresistance of cancer cells. This highlights mitochondria as a promising target for new anticancer strategies. Emergent evidence suggests that some snake venom toxins, both proteins with enzymatic and non-enzymatic activities, act on the mitochondrial metabolism of cancer cells, exhibiting unique and novel mechanisms that are not yet fully understood. Currently, six toxin classes (L-amino acid oxidases, thrombin-like enzymes, secreted phospholipases A2, three-finger toxins, cysteine-rich secreted proteins, and snake C-type lectin) that alter the mitochondrial bioenergetics have been described. These toxins act through Complex IV activity inhibition, OXPHOS uncoupling, ROS-mediated permeabilization of inner mitochondrial membrane (IMM), IMM reorganization by cardiolipin interaction, and mitochondrial fragmentation with selective migrastatic and cytotoxic effects on cancer cells. Notably, selective internalization and direct action of snake venom toxins on tumor mitochondria can be mediated by cell surface proteins overexpressed in cancer cells (e.g. nucleolin and heparan sulfate proteoglycans) or facilitated by the elevated Δψm of cancer cells compared to that non-tumor cells. In this latter case, selective mitochondrial accumulation, in a Δψm-dependent manner, of compounds linked to cationic snake peptides may be explored as a new anti-cancer drug delivery system. This review analyzes the effect of snake venom toxins on mitochondrial bioenergetics of cancer cells, whose mechanisms of action may offer the opportunity to develop new anticancer drugs based on toxin scaffolds.
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Affiliation(s)
- Félix A. Urra
- Laboratorio de Plasticidad Metabólica y Bioenergética, Programa de Farmacología Clínica y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Network for Snake Venom Research and Drug Discovery, Santiago, Chile
- Interdisciplinary Group on Mitochondrial Targeting and Bioenergetics (MIBI), Talca, Chile
- *Correspondence: Félix A. Urra,
| | - Dan E. Vivas-Ruiz
- Network for Snake Venom Research and Drug Discovery, Santiago, Chile
- Laboratorio de Biología Molecular, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Ciudad Universitaria, Lima, Peru
| | - Eladio Flores Sanchez
- Network for Snake Venom Research and Drug Discovery, Santiago, Chile
- Laboratory of Biochemistry of Proteins from Animal Venoms, Research and Development Center, Ezequiel Dias Foundation, Belo Horizonte, Brazil
| | - Ramiro Araya-Maturana
- Network for Snake Venom Research and Drug Discovery, Santiago, Chile
- Interdisciplinary Group on Mitochondrial Targeting and Bioenergetics (MIBI), Talca, Chile
- Laboratorio de Productos Bioactivos, Instituto de Química de Recursos Naturales, Universidad de Talca, Talca, Chile
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Zhang X, Yang Y, Guo L, Zhou J, Niu J, Wang P, Qiang Y, Liu K, Wen Y, Zhang L, Wang F. GPER1 Modulates Synaptic Plasticity During the Development of Temporal Lobe Epilepsy in Rats. Neurochem Res 2021; 46:2019-2032. [PMID: 34076791 DOI: 10.1007/s11064-021-03336-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/23/2021] [Accepted: 04/27/2021] [Indexed: 11/30/2022]
Abstract
G-protein coupled estrogen receptor 1 (GPER1) is a novel type of estrogen receptor. Several studies have shown that it has an anti-inflammatory action,which plays an important role in remyelination and cognitive ability adjustment. However, whether it is involved in the development of temporal lobe epilepsy (TLE) is still unknown. The present study established a TLE model by intraperitoneal injection of lithium chloride (3 mmol/kg) and pilocarpine (50 mg/kg) in rats to study the effect of GPER1 in the synaptic plasticity during the development of temporal lobe epilepsy. A microinjection cannula was implanted into the lateral ventricle region of rats via a stereotaxic instrument. G-1 is the specific GPER1 agonist and G15 is the specific GPER1 antagonist. The G1 or G15 and Dimethyl sulfoxide were injected into the rat brains in the intervention groups and control group, respectively. After G1 intervention, the learning and memory abilities and hippocampal neuron damage in epileptic rats were significantly improved, while G15 weakened the neuroprotective effect of GPER1. Meanwhile, G1 controlled the abnormal formation of hippocampal mossy fiber sprouting caused by seizures, and participated in the regulation of synaptic plasticity by reducing the expression of Synapsin I and increasing the expression of gephyrin. Inhibitory synapse gephyrin may play a significant role in synaptic plasticity.
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Affiliation(s)
- Xian Zhang
- Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
| | - Yang Yang
- Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
- School of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
| | - Li Guo
- School of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
| | - Jinyu Zhou
- School of Public Health and Management, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
| | - Jianguo Niu
- Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
- School of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
| | - Peng Wang
- Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
| | - Yuanyuan Qiang
- Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
| | - Kunmei Liu
- Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
| | - Yujun Wen
- Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
- School of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China
| | - Lianxiang Zhang
- Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China.
- School of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China.
| | - Feng Wang
- Ningxia Key Laboratory of Cerebrocranial Diseases, Incubation Base of the National Key Laboratory, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750001, Ningxia, China.
- Department of Neurosurgery, General Hospital of Ningxia Medical University, 804 Shengli Street, Yinchuan, 750001, Ningxia, China.
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3
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Negro S, Bergamin E, Rodella U, Duregotti E, Scorzeto M, Jalink K, Montecucco C, Rigoni M. ATP Released by Injured Neurons Activates Schwann Cells. Front Cell Neurosci 2016; 10:134. [PMID: 27242443 PMCID: PMC4876115 DOI: 10.3389/fncel.2016.00134] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/06/2016] [Indexed: 11/13/2022] Open
Abstract
Injured nerve terminals of neuromuscular junctions (NMJs) can regenerate. This remarkable and complex response is governed by molecular signals that are exchanged among the cellular components of this synapse: motor axon nerve terminal (MAT), perisynaptic Schwann cells (PSCs), and muscle fiber. The nature of signals that govern MAT regeneration is ill-known. In the present study the spider toxin α-latrotoxin has been used as tool to investigate the mechanisms underlying peripheral neuroregeneration. Indeed this neurotoxin induces an acute, specific, localized and fully reversible damage of the presynaptic nerve terminal, and its action mimics the cascade of events that leads to nerve terminal degeneration in injured patients and in many neurodegenerative conditions. Here we provide evidence of an early release by degenerating neurons of adenosine triphosphate as alarm messenger, that contributes to the activation of a series of intracellular pathways within Schwann cells that are crucial for nerve regeneration: Ca(2+), cAMP, ERK1/2, and CREB. These results contribute to define the cross-talk taking place among degenerating nerve terminals and PSCs, involved in the functional recovery of the NMJ.
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Affiliation(s)
- Samuele Negro
- Department of Biomedical Sciences, University of PadovaPadua, Italy
| | | | - Umberto Rodella
- Department of Biomedical Sciences, University of PadovaPadua, Italy
| | - Elisa Duregotti
- Department of Biomedical Sciences, University of PadovaPadua, Italy
| | - Michele Scorzeto
- Department of Biomedical Sciences, University of PadovaPadua, Italy
| | - Kees Jalink
- Division of Cell Biology, The Netherlands Cancer InstituteAmsterdam, Netherlands
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of PadovaPadua, Italy
- National Research Council, Institute of NeurosciencePadua, Italy
| | - Michela Rigoni
- Department of Biomedical Sciences, University of PadovaPadua, Italy
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4
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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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Abstract
Snakebite is classified by the WHO as a neglected tropical disease. Envenoming is a significant public health problem in tropical and subtropical regions. Neurotoxicity is a key feature of some envenomings, and there are many unanswered questions regarding this manifestation. Acute neuromuscular weakness with respiratory involvement is the most clinically important neurotoxic effect. Data is limited on the many other acute neurotoxic manifestations, and especially delayed neurotoxicity. Symptom evolution and recovery, patterns of weakness, respiratory involvement, and response to antivenom and acetyl cholinesterase inhibitors are variable, and seem to depend on the snake species, type of neurotoxicity, and geographical variations. Recent data have challenged the traditional concepts of neurotoxicity in snake envenoming, and highlight the rich diversity of snake neurotoxins. A uniform system of classification of the pattern of neuromuscular weakness and models for predicting type of toxicity and development of respiratory weakness are still lacking, and would greatly aid clinical decision making and future research. This review attempts to update the reader on the current state of knowledge regarding this important issue.
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Affiliation(s)
- Udaya K. Ranawaka
- Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka
- * E-mail:
| | - David G. Lalloo
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Duregotti E, Tedesco E, Montecucco C, Rigoni M. Calpains participate in nerve terminal degeneration induced by spider and snake presynaptic neurotoxins. Toxicon 2012; 64:20-8. [PMID: 23266309 DOI: 10.1016/j.toxicon.2012.12.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 11/13/2012] [Accepted: 12/13/2012] [Indexed: 11/19/2022]
Abstract
α-latrotoxin and snake presynaptic phospholipases A2 neurotoxins target the presynaptic membrane of axon terminals of the neuromuscular junction causing paralysis. These neurotoxins display different biochemical activities, but similarly alter the presynaptic membrane permeability causing Ca(2+) overload within the nerve terminals, which in turn induces nerve degeneration. Using different methods, here we show that the calcium-activated proteases calpains are involved in the cytoskeletal rearrangements that we have previously documented in neurons exposed to α-latrotoxin or to snake presynaptic phospholipases A2 neurotoxins. These results indicate that calpains, activated by the massive calcium influx from the extracellular medium, target fundamental components of neuronal cytoskeleton such as spectrin and neurofilaments, whose cleavage is functional to the ensuing nerve terminal fragmentation.
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Affiliation(s)
- Elisa Duregotti
- Department of Biomedical Sciences, CNR Institute of Neuroscience, University of Padova, Italy
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Treppmann P, Brunk I, Afube T, Richter K, Ahnert-Hilger G. Neurotoxic phospholipases directly affect synaptic vesicle function. J Neurochem 2011; 117:757-64. [PMID: 21401596 DOI: 10.1111/j.1471-4159.2011.07247.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Snake neurotoxic phospholipases (SPAN) exclusively affect pre-synaptic nerve terminals where they lead to a block of neurotransmission by not fully understood mechanisms. Here, we report that the SPANs, taipoxin and paradoxin, in nanomolar concentrations directly dissociate the synaptophysin/synaptobrevin (Syp/Syb) complex on isolated synaptic vesicles in the presence of synaptosomal cytosol. The phospholipase activity of SPANs depends on Ca(2+) but the dissociation of the Syp/Syb complex does not require Ca(2+). Ca(2+) (100 μM free) alone also dissociates the Syp/Syb complex in the presence of cytosol. Treatment with SPANs disturbs the lipid raft association of synaptophysin and synaptobrevin comparable to cholesterol depletion by β-methyl-cyclodextrin while Ca(2+) alone has no effect. SPANs but not Ca(2+) directly inhibit vesicular uptake of serotonin and glutamate. It is concluded that SPANs directly affect vesicular properties independent from their Ca(2+) -dependent phospholipase activity. SPANs and Ca(2+) dissociate the Syp/Syb complex as a prerequisite for exocytosis. SPANs also prevent the filling of synaptic vesicles thereby adding to the inhibition of neurotransmission.
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Affiliation(s)
- Philipp Treppmann
- AG Funktionelle Zellbiologie, Institut für Integrative Neuroanatomie, Charité Centrum 2 für Grundlagenmedizin, Berlin, Germany
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Silva-Cardoso L, Caccin P, Magnabosco A, Patrón M, Targino M, Fuly A, Oliveira GA, Pereira MH, do Carmo MDGT, Souza AS, Silva-Neto MAC, Montecucco C, Atella GC. Paralytic activity of lysophosphatidylcholine from saliva of the waterbug Belostoma anurum. J Exp Biol 2010; 213:3305-10. [DOI: 10.1242/jeb.041954] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Lysophosphatidylcholine (LPC) is a major bioactive lipid that is enzymatically generated by phospholipase A2 (PLA2). Previously, we showed that LPC is present in the saliva of the blood-sucking hemipteran Rhodnius prolixus and modulates cell-signaling pathways involved in vascular biology, which aids blood feeding. Here, we show that the saliva of the predator insect Belostoma anurum contains a large number of lipids with LPC accounting for 25% of the total phospholipids. A PLA2 enzyme likely to be involved in LPC generation was characterized. The activity of this enzyme is 5-fold higher in Belostoma saliva than in other studied hemipterans, suggesting a close association with the predator feeding habits of this insect. Belostoma employs extra-oral digestion, which allows for ingestion of larger prey than itself, including small vertebrates such as amphibians and fish. Therefore, prey immobilization during digestion is essential, and we show here that Belostoma saliva and B. anurum saliva purified LPC have paralytic activity in zebrafish. This is the first evidence that lysophospholipids might play an important role in prey immobilization, in addition to contributing to blood feeding, and might have been an evolutionary acquisition that occurred long before the appearance of hematophagy in this animal group.
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Affiliation(s)
- Lívia Silva-Cardoso
- Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Università di Padova, Padova, Italy
| | - Paola Caccin
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy
| | - Anna Magnabosco
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy
| | - Maria Patrón
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy
| | - Mariane Targino
- Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil
| | - André Fuly
- Universidade Federal Fluminense, UFF, Niterói, Rio de Janeiro, Brazil
| | - Giselle A. Oliveira
- Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil
| | - Marcos H. Pereira
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Università di Padova, Padova, Italy
- Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Minas Gerais, Brazil
| | | | - Amanda S. Souza
- Instituto de Nutrição, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Brazil
| | - Mário A. C. Silva-Neto
- Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Università di Padova, Padova, Italy
| | - Cesare Montecucco
- Dipartimento di Scienze Biomediche, Università di Padova, Padova, Italy
| | - Georgia C. Atella
- Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Università di Padova, Padova, Italy
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9
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Honoré B. The rapidly expanding CREC protein family: members, localization, function, and role in disease. Bioessays 2009; 31:262-77. [PMID: 19260022 DOI: 10.1002/bies.200800186] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although many aspects of the physiological and pathophysiological mechanisms remain unknown, recent advances in our knowledge suggest that the CREC proteins are promising disease biomarkers or targets for therapeutic intervention in a variety of diseases. The CREC family of low affinity, Ca2+-binding, multiple EF-hand proteins are encoded by five genes, RCN1, RCN2, RCN3, SDF4, and CALU, resulting in reticulocalbin, ER Ca2+-binding protein of 55 kDa (ERC-55), reticulocalbin-3, Ca2+-binding protein of 45 kDa (Cab45), and calumenin. Alternative splicing increases the number of gene products. The proteins are localized in the cytosol, in various parts of the secretory pathway, secreted to the extracellular space or localized on the cell surface. The emerging functions appear to be highly diverse. The proteins interact with several different ligands. Rather well-described functions are attached to calumenin with the inhibition of several proteins in the endoplasmic or sarcoplasmic reticulum membrane, the vitamin K(1) 2,3-epoxide reductase, the gamma-carboxylase, the ryanodine receptor, and the Ca2+-transporting ATPase. Other functions concern participation in the secretory process, chaperone activity, signal transduction as well as participation in a large variety of disease processes.
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Affiliation(s)
- Bent Honoré
- Department of Medical Biochemistry, Aarhus University, Aarhus C, Denmark.
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Tedesco E, Rigoni M, Caccin P, Grishin E, Rossetto O, Montecucco C. Calcium overload in nerve terminals of cultured neurons intoxicated by alpha-latrotoxin and snake PLA2 neurotoxins. Toxicon 2009; 54:138-44. [DOI: 10.1016/j.toxicon.2009.03.025] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 03/12/2009] [Accepted: 03/23/2009] [Indexed: 10/20/2022]
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11
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Ito H, Atsuzawa K, Morishita R, Usuda N, Sudo K, Iwamoto I, Mizutani K, Katoh-Semba R, Nozawa Y, Asano T, Nagata KI. Sept8 controls the binding of vesicle-associated membrane protein 2 to synaptophysin. J Neurochem 2009; 108:867-80. [PMID: 19196426 DOI: 10.1111/j.1471-4159.2008.05849.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Septins, a conserved family of GTP/GDP-binding proteins, are present in organisms as diverse as yeast and mammals. We analyzed the distribution of five septins, Sept6, Sept7, Sept8, Sept9 and Sept11, in various rat tissues by western blot analyses and found all septins to be expressed in brain. We also examined the developmental changes of expression of these septins in the rat brain and found that the level of Sept8 increased during post-natal development. Morphological analyses revealed that Sept8 is enriched at pre-synapses. Using yeast two-hybrid screening, we identified vesicle-associated membrane protein 2 (VAMP2), a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE), as an interacting protein for Sept8. Synaptophysin is reported to associate with and recruit VAMP2 to synaptic vesicles and dissociate prior to forming the SNARE complex consisting of VAMP2, syntaxin and synaptosome-associated protein of 25 kDa. We showed that Sept8 suppresses the interaction between VAMP2 and synaptophysin through binding to VAMP2. In addition, we found that Sept8 forms a complex with syntaxin1A, and the Sept8-VAMP2 interaction is disrupted by synaptosome-associated protein of 25 kDa. These results suggest that Sept8 may participate in the process of the SNARE complex formation and subsequent neurotransmitter release.
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Affiliation(s)
- Hidenori Ito
- Institute for Developmental Research, Aichi Human Service Center, Kasugai, Japan
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12
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Rigoni M, Paoli M, Milanesi E, Caccin P, Rasola A, Bernardi P, Montecucco C. Snake phospholipase A2 neurotoxins enter neurons, bind specifically to mitochondria, and open their transition pores. J Biol Chem 2008; 283:34013-20. [PMID: 18809685 DOI: 10.1074/jbc.m803243200] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Snake presynaptic neurotoxins with phospholipase A(2) activity are potent inducers of paralysis through inhibition of the neuromuscular junction. These neurotoxins were recently shown to induce exocytosis of synaptic vesicles following the production of lysophospholipids and fatty acids and a sustained influx of Ca(2+) from the medium. Here, we show that these toxins are able to penetrate spinal cord motor neurons and cerebellar granule neurons and selectively bind to mitochondria. As a result of this interaction, mitochondria depolarize and undergo a profound shape change from elongated and spaghetti-like to round and swollen. We show that snake presynaptic phospholipase A(2) neurotoxins facilitate opening of the mitochondrial permeability transition pore, an inner membrane high-conductance channel. The relative potency of the snake neurotoxins was similar for the permeability transition pore opening and for the phospholipid hydrolysis activities, suggesting a causal relationship, which is also supported by the effect of phospholipid hydrolysis products, lysophospholipids and fatty acids, on mitochondrial pore opening. These findings contribute to define the cellular events that lead to intoxication of nerve terminals by these snake neurotoxins and suggest that mitochondrial impairment is an important determinant of their toxicity.
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Affiliation(s)
- Michela Rigoni
- Dipartimento di Scienze Biomediche Sperimentali, Università di Padova and Istituto di Neuroscienze del Consiglio Nazionale delle Ricerche, Viale Giuseppe Colombo 3, I-35121 Padova, Italy
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13
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14
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Oliveira D, Harasawa C, Seibert C, Casais e Silva L, Pimenta D, Lebrun I, Sandoval M. Phospholipases A2 isolated from Micrurus lemniscatus coral snake venom: Behavioral, electroencephalographic, and neuropathological aspects. Brain Res Bull 2008; 75:629-39. [DOI: 10.1016/j.brainresbull.2007.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 10/10/2007] [Accepted: 10/17/2007] [Indexed: 01/25/2023]
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15
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Abstract
Toxins that alter neurotransmitter release from nerve terminals are of considerable scientific and clinical importance. Many advances were recently made in the understanding of their molecular mechanisms of action and use in human therapy. Here, we focus on presynaptic neurotoxins, which are very potent inhibitors of the neurotransmitter release because they are endowed with specific enzymatic activities: (1) clostridial neurotoxins with a metallo-proteolytic activity and (2) snake presynaptic neurotoxins with a phospholipase A2 activity.
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Affiliation(s)
- Ornella Rossetto
- Departimento de Scienze Biomediche and Istituto CNR di Neuroscienze, Universita di Padova, Viale G. Colombo 3, 35121, Padova, Italy
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16
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Pungercar J, Krizaj I. Understanding the molecular mechanism underlying the presynaptic toxicity of secreted phospholipases A2. Toxicon 2007; 50:871-92. [PMID: 17905401 DOI: 10.1016/j.toxicon.2007.07.025] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 07/13/2007] [Accepted: 07/20/2007] [Indexed: 11/24/2022]
Abstract
An important group of toxins, whose action at the molecular level is still a matter of debate, is secreted phospholipases A(2) (sPLA(2)s) endowed with presynaptic or beta-neurotoxicity. The current belief is that these beta-neurotoxins (beta-ntxs) exert their toxicity primarily due to their extracellular enzymatic action on the plasma membrane of motoneurons at the neuromuscular junction. However, the discovery of several extra- and intracellular proteins, with high binding affinity for snake venom beta-ntxs, has raised the question as to whether this explanation is adequate to account for all the observed phenomena in the process of presynaptic toxicity. The purpose of this review is to critically examine the various published studies, including the most recent results on internalization of a beta-ntx into motor nerve terminals, in order to contribute to a better understanding of the molecular mechanism of beta-neurotoxicity. As a result, we propose that presynaptic neurotoxicity of sPLA(2)s is a result of both extra- and intracellular actions of beta-ntxs, involving enzymatic activity as well as interaction of the toxins with intracellular proteins affecting the cycling of synaptic vesicles in the axon terminals of vertebrate motoneurons.
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Affiliation(s)
- Joze Pungercar
- Department of Molecular and Biomedical Sciences, Jozef Stefan Institute, SI-1000 Ljubljana, Slovenia
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Bonanomi D, Rusconi L, Colombo C, Benfenati F, Valtorta F. Synaptophysin I selectively specifies the exocytic pathway of synaptobrevin 2/VAMP2. Biochem J 2007; 404:525-34. [PMID: 17331077 PMCID: PMC1896278 DOI: 10.1042/bj20061907] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Biogenesis and recycling of synaptic vesicles are accompanied by sorting processes that preserve the molecular composition of the compartments involved. In the present study, we have addressed the targeting of synaptobrevin 2/VAMP2 (vesicle-associated membrane protein 2), a critical component of the synaptic vesicle--fusion machinery, in a heterotypic context where its sorting is not confounded by the presence of other neuron-specific molecules. Ectopically expressed synaptophysin I interacts with VAMP2 and alters its default surface targeting to a prominent vesicular distribution, with no effect on the targeting of other membrane proteins. Protein-protein interaction is not sufficient for the control of VAMP2 sorting, which is mediated by the C-terminal domain of synaptophysin I. Synaptophysin I directs the sorting of VAMP2 to vesicles before surface delivery, without influencing VAMP2 endocytosis. Consistent with this, dynamin and alpha-SNAP (soluble N-ethylmaleimide-sensitive fusion protein-attachment protein) mutants which block trafficking at the plasma membrane do not abrogate the effect of synaptophysin I on VAMP2 sorting. These results indicate that the sorting determinants of synaptic vesicle proteins can operate independently of a neuronal context and implicate the association of VAMP2 with synaptophysin I in the specification of the pathway of synaptic vesicle biogenesis.
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Affiliation(s)
- Dario Bonanomi
- *San Raffaele Scientific Institute and “Vita-Salute” University, Via Olgettina 58, 20132 Milan, Italy
| | - Laura Rusconi
- *San Raffaele Scientific Institute and “Vita-Salute” University, Via Olgettina 58, 20132 Milan, Italy
| | - Chiara Agnese Colombo
- *San Raffaele Scientific Institute and “Vita-Salute” University, Via Olgettina 58, 20132 Milan, Italy
| | - Fabio Benfenati
- †Department of Neuroscience, The Italian Institute of Technology, Genova, Italy
- ‡Department of Experimental Medicine, University of Genova, Via Benedetto XV 3, 16132 Genova, Italy
| | - Flavia Valtorta
- *San Raffaele Scientific Institute and “Vita-Salute” University, Via Olgettina 58, 20132 Milan, Italy
- §The Italian Institute of Technology, Research Unit of Molecular Neuroscience, via Olgettina 58, 20132 Milan, Italy
- To whom correspondence should be addressed (email )
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Giner D, López I, Neco P, Rossetto O, Montecucco C, Gutiérrez LM. Glycogen synthase kinase 3 activation is essential for the snake phospholipase A2 neurotoxin-induced secretion in chromaffin cells. Eur J Neurosci 2007; 25:2341-8. [PMID: 17445232 DOI: 10.1111/j.1460-9568.2007.05497.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Neuroendocrine chromaffin cells were used to study the mechanism of the snake phospholipase A2 (PLA2) neurotoxin enhancement of exocytosis. Notexin, beta-bungarotoxin, taipoxin or textilotoxin enhanced the fast release of catecholamines elicited by flash photolysis of cytosolic caged calcium. Such an increase correlates with the capacity of these neurotoxins to cause fragmentation of the F-actin cortical barrier with subsequent accumulation of vesicles in the proximity of the plasma membrane. These PLA2 neurotoxins do not act via protein kinase C activation, which is known to promote F-actin fragmentation. Lithium, RO31-8220 and SB216763, three inhibitors of the glycogen synthase kinase 3, prevent both the alteration of the F-actin peripheral cortex and the enhancement of fast release elicited by these neurotoxins. In addition, glycogen synthase kinase 3 has been detected by immunolocalization in a membranous compartment of the chromaffin cell endoplasmic reticulum (ER). These results suggest that the activation of this enzyme plays a major role in the enhancement of exocytosis of the readily releasable granules caused by PLA2 neurotoxins in neuroendocrine chromaffin cells.
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Affiliation(s)
- Daniel Giner
- Instituto de Neurociencias, Centro Mixto CSIC-Universidad Miguel Hernández, Campus de San Juan, 03550 Alicante, Spain
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Rigoni M, Pizzo P, Schiavo G, Weston AE, Zatti G, Caccin P, Rossetto O, Pozzan T, Montecucco C. Calcium Influx and Mitochondrial Alterations at Synapses Exposed to Snake Neurotoxins or Their Phospholipid Hydrolysis Products. J Biol Chem 2007; 282:11238-45. [PMID: 17311918 DOI: 10.1074/jbc.m610176200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Snake presynaptic phospholipase A2 neurotoxins (SPANs) bind to the presynaptic membrane and hydrolyze phosphatidylcholine with generation of lysophosphatidylcholine (LysoPC) and fatty acid (FA). The LysoPC+FA mixture promotes membrane fusion, inducing the exocytosis of the ready-to-release synaptic vesicles. However, also the reserve pool of synaptic vesicles disappears from nerve terminals intoxicated with SPAN or LysoPC+FA. Here, we show that LysoPC+FA and SPANs cause a large influx of extracellular calcium into swollen nerve terminals, which accounts for the extensive synaptic vesicle release. This is paralleled by the change of morphology and the collapse of membrane potential of mitochondria within nerve bulges. These results complete the picture of events occurring at nerve terminals intoxicated by SPANs and define the LysoPC+FA lipid mixture as a novel and effective agonist of synaptic vesicle release.
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Affiliation(s)
- Michela Rigoni
- Department of Biomedical Sciences and Consiglio Nazionale Ricerche Institute of Neuroscience, University of Padova, 35121 Padova, Italy
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Megighian A, Rigoni M, Caccin P, Zordan MA, Montecucco C. A lysolecithin/fatty acid mixture promotes and then blocks neurotransmitter release at the Drosophila melanogaster larval neuromuscular junction. Neurosci Lett 2007; 416:6-11. [PMID: 17293048 DOI: 10.1016/j.neulet.2007.01.040] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 01/15/2007] [Accepted: 01/19/2007] [Indexed: 11/17/2022]
Abstract
The study of the effect of snake presynaptic neurotoxins with phospholipase A2 activity on nerve terminals has recently unveiled the inhibitory action of a lysophosphatidylcholine (LysoPC)/fatty acid mixture. We report here that these neurotoxins have no activity on Drosophila melanogaster nerve terminals. However, a 1:1 mixture of LysoPC and oleic acid induces an early increase, followed by an inhibition of both evoked and spontaneous neurotransmitter release. This effect is also induced by LysoPC alone. The present findings provide an indirect evidence that the lipid hemifusion-to-pore transition is a key event in neuroexocytosis in Drosophila. Moreover, these findings substantiate the use of LysoPC as a general agonist of membrane fusion at nerve terminals. This novel tool could contribute to the unraveling of the molecular steps involved in neuroexocytosis, particularly in Drosophila, where it is straightforward to combine it with electrophysiology and genetics.
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Affiliation(s)
- Aram Megighian
- Department of Human Anatomy and Physiology, Section of Physiology, University of Padova, Via Marzolo 3, Padova, Italy.
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Chang Y, Li Y, Bao Y, An L. Neurotoxic activity of Gln49 phospholipase A2 fromGloydius ussuriensis snake venom. J Appl Toxicol 2007; 27:447-52. [PMID: 17299814 DOI: 10.1002/jat.1222] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A novel neurotoxic protein phospholipase A(2) (PLA(2)), molecular weight 13 881.83 Da, has been isolated from snake venom of Gloydius ussuriensis, named as Gln49-PLA(2), which shows weak lethal toxic, myotoxic and apparent anticoagulant activity, but lacks phospholipase activity. The Gln49-PLA(2) obviously induced an increase of the pain threshold in intoxicated 615 mice compared with the control group, suggesting it is a neurotoxin. Hot-plate tests also showed that its analgesic activity was dose-dependent, and naloxone antagonized the analgesic effect, implying the mechanism of action of Gln49-sPLA(2) is correlated with opioid receptors. Electrophysiology studies revealed decreases in the action potential and the nerve conduction velocity in isolated hoptoad (Bufo bufo gargarizans Cantor) sciatic nerve, indicating Gln49-PLA(2) most probably had effects on ion channels.
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Affiliation(s)
- Yan Chang
- Department of Bioscience and Biotechnology, Dalian University of Technology, 2 Linggong road, Dalian 116024, P. R. China
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Bonanomi D, Benfenati F, Valtorta F. Protein sorting in the synaptic vesicle life cycle. Prog Neurobiol 2006; 80:177-217. [PMID: 17074429 DOI: 10.1016/j.pneurobio.2006.09.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 09/14/2006] [Accepted: 09/18/2006] [Indexed: 01/06/2023]
Abstract
At early stages of differentiation neurons already contain many of the components necessary for synaptic transmission. However, in order to establish fully functional synapses, both the pre- and postsynaptic partners must undergo a process of maturation. At the presynaptic level, synaptic vesicles (SVs) must acquire the highly specialized complement of proteins, which make them competent for efficient neurotransmitter release. Although several of these proteins have been characterized and linked to precise functions in the regulation of the SV life cycle, a systematic and unifying view of the mechanisms underlying selective protein sorting during SV biogenesis remains elusive. Since SV components do not share common sorting motifs, their targeting to SVs likely relies on a complex network of protein-protein and protein-lipid interactions, as well as on post-translational modifications. Pleiomorphic carriers containing SV proteins travel and recycle along the axon in developing neurons. Nevertheless, SV components appear to eventually undertake separate trafficking routes including recycling through the neuronal endomembrane system and the plasmalemma. Importantly, SV biogenesis does not appear to be limited to a precise stage during neuronal differentiation, but it rather continues throughout the entire neuronal lifespan and within synapses. At nerve terminals, remodeling of the SV membrane results from the use of alternative exocytotic pathways and possible passage through as yet poorly characterized vacuolar/endosomal compartments. As a result of both processes, SVs with heterogeneous molecular make-up, and hence displaying variable competence for exocytosis, may be generated and coexist within the same nerve terminal.
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Affiliation(s)
- Dario Bonanomi
- Department of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
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Caccin P, Rigoni M, Bisceglie A, Rossetto O, Montecucco C. Reversible skeletal neuromuscular paralysis induced by different lysophospholipids. FEBS Lett 2006; 580:6317-21. [PMID: 17083939 DOI: 10.1016/j.febslet.2006.10.039] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Revised: 10/17/2006] [Accepted: 10/18/2006] [Indexed: 11/25/2022]
Abstract
Lysophosphatidylcholine rapidly paralyses the neuromuscular junction (NMJ), similarly to snake phospholipase A2 neurotoxins, implicating a lipid hemifusion-pore transition in neuroexocytosis. The mode and kinetics of NMJ paralysis of different lysophospholipids (lysoPLs) in high or low [Mg2+] was investigated. The following order of potency was found: lysophosphatidylcholine>lysophosphatidylethanolamine>lysophosphatidic acid>lysophosphatidylserine>lysophosphatidylglycerol. The latter two lysoPLs closely mimic the profile of paralysis caused by the toxins in high [Mg2+]. This paralysis is fully reversed by albumin washing. These findings provide novel insights on the mode of action of snake neurotoxins and qualify lysoPLs as novel agents to study neuroexocytosis.
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Affiliation(s)
- Paola Caccin
- Dipartimento di Scienze Biomediche, Istituto C.N.R. Neuroscienze, Università di Padova, Viale G. Colombo n. 3, 35121 Padova, Italy
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Abstract
Botulinum neurotoxins produced by anaerobic bacteria of the genus Clostridium are the most toxic proteins known, with mouse LD50 values in the 1-5 ng/kg range, and are solely responsible for the pathophysiology of botulism. These metalloproteinases enter peripheral cholinergic nerve terminals and cleave proteins of the neuroexocytosis apparatus, causing a persistent, but reversible, inhibition of neurotransmitter release. They are used in the therapy of many human syndromes caused by hyperactive nerve terminals. Snake presynaptic PLA2 neurotoxins block nerve terminals by binding to the nerve membrane and catalyzing phospholipid hydrolysis with production of lysophospholipids and fatty acids. These compounds change the membrane conformation, causing enhanced fusion of synaptic vesicle via hemifusion intermediate with release of neurotransmitter and, at the same time, inhibition of vesicle fission and recycling. It is possible to envisage clinical applications of the lysophospholipid/fatty acid mixture to inhibit hyperactive superficial nerve terminals.
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Affiliation(s)
- Ornella Rossetto
- Dipartimento di Scienze Biomediche and Istituto CNR di Neuroscienze, Università di Padova, Padova, Italy.
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Rigoni M, Caccin P, Gschmeissner S, Koster G, Postle AD, Rossetto O, Schiavo G, Montecucco C. Equivalent Effects of Snake PLA2 Neurotoxins and Lysophospholipid-Fatty Acid Mixtures. Science 2005; 310:1678-80. [PMID: 16339444 DOI: 10.1126/science.1120640] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Snake presynaptic phospholipase A2 neurotoxins (SPANs) paralyze the neuromuscular junction (NMJ). Upon intoxication, the NMJ enlarges and has a reduced content of synaptic vesicles, and primary neuronal cultures show synaptic swelling with surface exposure of the lumenal domain of the synaptic vesicle protein synaptotagmin I. Concomitantly, these neurotoxins induce exocytosis of neurotransmitters. We found that an equimolar mixture of lysophospholipids and fatty acids closely mimics all of the biological effects of SPANs. These results draw attention to the possible role of local lipid changes in synaptic vesicle release and provide new tools for the study of exocytosis.
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Affiliation(s)
- Michela Rigoni
- Department of Biomedical Sciences and Consiglio Nazionale Ricerche Institute of Neuroscience, University of Padova, Italy
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