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Neurobiology and therapeutic applications of neurotoxins targeting transmitter release. Pharmacol Ther 2019; 193:135-155. [DOI: 10.1016/j.pharmthera.2018.08.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Walker AA, Robinson SD, Yeates DK, Jin J, Baumann K, Dobson J, Fry BG, King GF. Entomo-venomics: The evolution, biology and biochemistry of insect venoms. Toxicon 2018; 154:15-27. [DOI: 10.1016/j.toxicon.2018.09.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 08/23/2018] [Accepted: 09/17/2018] [Indexed: 12/27/2022]
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Ratcliffe NA, Mello CB, Garcia ES, Butt TM, Azambuja P. Insect natural products and processes: new treatments for human disease. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2011; 41:747-69. [PMID: 21658450 DOI: 10.1016/j.ibmb.2011.05.007] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 05/16/2011] [Accepted: 05/20/2011] [Indexed: 05/09/2023]
Abstract
In this overview, some of the more significant recent developments in bioengineering natural products from insects with use or potential use in modern medicine are described, as well as in utilisation of insects as models for studying essential mammalian processes such as immune responses to pathogens. To date, insects have been relatively neglected as sources of modern drugs although they have provided valuable natural products, including honey and silk, for at least 4-7000 years, and have featured in folklore medicine for thousands of years. Particular examples of Insect Folk Medicines will briefly be described which have subsequently led through the application of molecular and bioengineering techniques to the development of bioactive compounds with great potential as pharmaceuticals in modern medicine. Insect products reviewed have been derived from honey, venom, silk, cantharidin, whole insect extracts, maggots, and blood-sucking arthropods. Drug activities detected include powerful antimicrobials against antibiotic-resistant bacteria and HIV, as well as anti-cancer, anti-angiogenesis and anti-coagulant factors and wound healing agents. Finally, the many problems in developing these insect products as human therapeutic drugs are considered and the possible solutions emerging to these problems are described.
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Affiliation(s)
- Norman A Ratcliffe
- Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Avenida Brasil 4365, Rio de Janeiro, 21045-900, RJ, Brazil.
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Chen J, Lariviere WR. The nociceptive and anti-nociceptive effects of bee venom injection and therapy: a double-edged sword. Prog Neurobiol 2010; 92:151-83. [PMID: 20558236 DOI: 10.1016/j.pneurobio.2010.06.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 03/31/2010] [Accepted: 06/08/2010] [Indexed: 12/23/2022]
Abstract
Bee venom injection as a therapy, like many other complementary and alternative medicine approaches, has been used for thousands of years to attempt to alleviate a range of diseases including arthritis. More recently, additional theraupeutic goals have been added to the list of diseases making this a critical time to evaluate the evidence for the beneficial and adverse effects of bee venom injection. Although reports of pain reduction (analgesic and antinociceptive) and anti-inflammatory effects of bee venom injection are accumulating in the literature, it is common knowledge that bee venom stings are painful and produce inflammation. In addition, a significant number of studies have been performed in the past decade highlighting that injection of bee venom and components of bee venom produce significant signs of pain or nociception, inflammation and many effects at multiple levels of immediate, acute and prolonged pain processes. This report reviews the extensive new data regarding the deleterious effects of bee venom injection in people and animals, our current understanding of the responsible underlying mechanisms and critical venom components, and provides a critical evaluation of reports of the beneficial effects of bee venom injection in people and animals and the proposed underlying mechanisms. Although further studies are required to make firm conclusions, therapeutic bee venom injection may be beneficial for some patients, but may also be harmful. This report highlights key patterns of results, critical shortcomings, and essential areas requiring further study.
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Affiliation(s)
- Jun Chen
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, 1 Xinsi Road, Baqiao District, Xi'an 710038, PR China.
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Yamazaki Y, Fujii S, Nakamura T, Miyakawa H, Kudo Y, Kato H, Ito KI. Changes in [Ca2+](i) during adenosine triphosphate-induced synaptic plasticity in hippocampal CA1 neurons of the guinea pig. Neurosci Lett 2002; 324:65-8. [PMID: 11983296 DOI: 10.1016/s0304-3940(02)00175-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The perfusion of adenosine triphosphate (ATP) induces long-term potentiation (LTP) in CA1 synapses of hippocampal slices, whereas the perfusion of ATP plus ,-2-amino-5-phosphonovaleric acid (AP5) can result in the formation of long-term depression (LTD). To clarify the difference in change of intracellular calcium concentration ([Ca2+]i) corresponding to induction of LTP or LTD, we measured [Ca2+]i during the perfusion of ATP or ATP+AP5, while simultaneously recording evoked field potentials. In both cases, ATP (or ATP+AP5) perfusion transiently increased [Ca2+]i but the extent of increase of [Ca2+]i by ATP was larger than that caused by ATP+AP5. Thus, the larger rise in [Ca2+]i induces LTP but the smaller rise induces LTD. These results are consistent with the Ca2+ hypothesis as proposed by Lisman (Trends Neurosci. 17 (1994) 406).
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Affiliation(s)
- Yoshihiko Yamazaki
- Department of Physiology, Yamagata University School of Medicine, 2-2-2 Iida Nishi, 990-9585, Japan
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Cochran SM, Harvey AL, Pratt JA. Regionally selective alterations in local cerebral glucose utilization evoked by charybdotoxin, a blocker of central voltage-activated K+-channels. Eur J Neurosci 2001; 14:1455-63. [PMID: 11722607 DOI: 10.1046/j.0953-816x.2001.01770.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The quantitative [14C]-2-deoxyglucose autoradiographic technique was employed to investigate the effect of charybdotoxin, a blocker of certain voltage-activated K+ channels, on functional activity, as reflected by changes in local rates of cerebral glucose utilization in rat brain. Intracerebroventricular administration of charybdotoxin, at doses below those producing seizure activity, produced a heterogeneous effect on glucose utilization throughout the brain. Out of the 75 brain regions investigated, 24 displayed alterations in glucose utilization. The majority of these changes were observed with the intermediate dose of charybdotoxin administered (12.5 pmol), with the lower (6.25 pmol) and higher (25 pmol) doses of charybdotoxin producing a much more restricted pattern of change in glucose utilization. In brain regions which displayed alterations in glucose at all doses of charybdotoxin administered, no dose dependency in terms of the magnitude of change was observed. The 21 brain regions which displayed altered functional activity after administration of 12.5 pmol charybdotoxin were predominantly limited to the hippocampus, limbic and motor structures. In particular, glucose utilization was altered within three pathways implicated within learning and memory processes, the septohippocampal pathway, Schaffer collaterals within the hippocampus and the Papez circuit. The nigrostriatal pathway also displayed altered local cerebral glucose utilization. These data indicate that charybdotoxin produces alterations in functional activity within selected pathways in the brain. Furthermore the results raise the possibility that manipulation of particular subtypes of Kv1 channels in the hippocampus and related structures may be a means of altering cognitive processes without causing global changes in neural activity throughout the brain.
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Affiliation(s)
- S M Cochran
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, Glasgow G4 ONR, UK
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Kourrich S, Mourre C, Soumireu-Mourat B. Kaliotoxin, a Kv1.1 and Kv1.3 channel blocker, improves associative learning in rats. Behav Brain Res 2001; 120:35-46. [PMID: 11173083 DOI: 10.1016/s0166-4328(00)00356-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Olfactory associative learning was used to investigate the involvement of Kv channels containing Kv1.1 and Kv1.3 alpha-subunits in learning and memory. Kaliotoxin (KTX), a specific inhibitor of these Kv channels, was injected intracerebroventricularly in the rat brain, at a dose of 10 ng that did not disturb the rats' locomotor activity or drinking behaviour. In the first paradigm (odour-reward training), KTX improved learning but not information consolidation. Moreover, KTX increased the long-term retrieval of an odour-reward association tested by a reversal test 1 month after the odour-reward training. The second paradigm (successive odour-pair training) tested reference memory. The first session was an acquisition session where the rats learned a new odour-discrimination problem with the same procedure. The second was a retention session held 24 h later to test retrieval of the learned information. KTX injected before the acquisition or retention session improved performance, but no effect was found when KTX was injected immediately after acquisition. We showed that these effects were not due to the action of KTX on attention processes. Thus, these results suggest that the blockage of Kv1.1 or Kv1.3 channels by KTX facilitates cognitive processes as learning, in particular in a reference representation.
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Affiliation(s)
- S Kourrich
- Laboratoire de Neurobiologie des Comportements, UMR 6562, CNRS-Université de Provence, IBHOP, Traverse Susini, 13388 Cedex 13, Marseille, France
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Abstract
Dendrotoxins are small proteins that were isolated 20 years ago from mamba (Dendroaspis) snake venoms (Harvey, A.L., Karlsson, E., 1980. Dendrotoxin from the venom of the green mamba, Dendroaspis angusticeps: a neurotoxin that enhances acetylcholine release at neuromuscular junctions. Naunyn-Schmiedebergs Arch. Pharmacol. 312, 1-6.). Subsequently, a family of related proteins was found in mamba venoms and shown to be homologous to Kunitz-type serine protease inhibitors, such as aprotinin. The dendrotoxins contain 57-60 amino acid residues cross-linked by three disulphide bridges. The dendrotoxins have little or no anti-protease activity, but they were demonstrated to block particular subtypes of voltage-dependent potassium channels in neurons. Studies with cloned K(+) channels indicate that alpha-dendrotoxin from green mamba Dendroaspis angusticeps blocks Kv1.1, Kv1.2 and Kv1.6 channels in the nanomolar range, whereas toxin K from the black mamba Dendroaspis polylepis preferentially blocks Kv1.1 channels. Structural analogues of dendrotoxins have helped to define the molecular recognition properties of different types of K(+) channels, and radiolabelled dendrotoxins have also been useful in helping to discover toxins from other sources that bind to K(+) channels. Because dendrotoxins are useful markers of subtypes of K(+) channels in vivo, dendrotoxins have become widely used as probes for studying the function of K(+) channels in physiology and pathophysiology.
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Affiliation(s)
- A L Harvey
- Department of Physiology and Pharmacology, University of Strathclyde, Glasgow G4 ONR, UK
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Behnisch T, Reymann KG. Inhibition of apamin-sensitive calcium dependent potassium channels facilitate the induction of long-term potentiation in the CA1 region of rat hippocampus in vitro. Neurosci Lett 1998; 253:91-4. [PMID: 9774157 DOI: 10.1016/s0304-3940(98)00612-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Using field potential recording in the CA1-region of rat hippocampal slices we investigated the effect of apamin; a specific antagonist of small conductive calcium activated potassium channels on long-term potentiation (LTP). The experiments revealed that LTP of excitatory postsynaptic potentials induced by a single 100 Hz tetanization was intensified by extracellular application of apamin in a concentration range of 1-200 nM. No effects of apamin on LTP induced by triple 100 Hz tetanization were seen. We conclude that the positive modulation of LTP by apamin is effective in a nanomolar concentration range and dependent upon the employed tetanization. Because it has been shown that apamin-binding sites are affected by learning disorders including Alzheimer's disease, our finding suggests that changes in the sensitivity to apamin may result in memory disorders.
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Affiliation(s)
- T Behnisch
- Leibniz Institute for Neurobiology, Project Group Neuropharmacology, Magdeburg, Germany.
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Nagayama T, Masada K, Yoshida M, Suzuki-Kusaba M, Hisa H, Kimura T, Satoh S. Role of K+ channels in adrenal catecholamine secretion in anesthetized dogs. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 274:R1125-30. [PMID: 9575978 DOI: 10.1152/ajpregu.1998.274.4.r1125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We examined the role of K+ channels in the secretion of adrenal catecholamine (CA) in response to splanchnic nerve stimulation (SNS), acetylcholine (ACh), 1,1-dimethyl-4-phenyl-piperazinium (DMPP), and muscarine in anesthetized dogs. K+ channel blockers and the cholinergic agonists were infused and injected, respectively, into the adrenal gland. The voltage-dependent K+ channel (KA type) blocker mast cell degranulating (MCD) peptide infusion (10-100 ng/min) enhanced increases in CA output induced by SNS (1-3 Hz), but it did not affect increases in CA output induced by ACh (0.75-3 micrograms), DMPP (0.1-0.4 microgram), or muscarine (0.5-2 micrograms). The small-conductance Ca(2+)-activated K+ (SKCa) channel blocker scyllatoxin infusion (10-100 ng/min) enhanced the ACh-, DMPP-, and muscarine-induced increases in CA output, but it did not affect the SNS-induced increases in CA output. These results suggest that KA channels may play an inhibitory role in the regulation of adrenal CA secretion in response to SNS and that SKCa channels may play the same role in the secretion in response to exogenously applied cholinergic agonists.
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Affiliation(s)
- T Nagayama
- Department of Pharmacology, Tohoku University, Sendai, Japan
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Abstract
1. Dendrotoxins are small proteins isolated from mamba (Dendroaspis) snake venoms. They block some subtypes of voltage-dependent potassium channels in neurons. 2. Dendrotoxins contain 57-60 amino acid residues crosslinked by three disulfide bridges. They are homologous to Kunitz-type serine protease inhibitors, such as aprotinin, although they have little or no antiprotease activity. 3. Dendrotoxins act mainly on neuronal K+ channels. Studies with cloned K+ channels indicate that alpha-dendrotoxin from green mamba Dendroaspis angusticeps blocks Kv1.1 and Kv1.2 channels in the nanomolar range. In native cells, dendrotoxin appears preferentially to block inactivating forms of K+ current. 4. Dendrotoxins can induce repetitive firing in neurons and facilitate transmitter release. On direct injection to the CNS, dendrotoxins can induce epileptiform activity. 5. Radiolabeled dendrotoxins are useful markers of subtypes of K+ channels in vivo, and structural analogs help to define the molecular recognition properties of different types of K+ channels.
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Affiliation(s)
- A L Harvey
- Department of Physiology and Pharmacology, University of Strathclyde, Glasgow, UK
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Fujimoto I, Oiki S, Kondo T, Katada T, Kato H, Taguchi T, Kasai M, Okada Y, Mikoshiba K, Ikenaka K. GTP-binding protein activation underlies LTP induction by mast cell degranulating peptide. Neurosci Res 1996; 25:229-37. [PMID: 8856719 DOI: 10.1016/0168-0102(96)01047-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mast cell degranulating peptide (MCD) induces long-term potentiation (LTP) in the CA1 region of the hippocampus. MCD has been shown to bind to a voltage-dependent A-type potassium channel with high-affinity (less than 1 nM). However, the concentration necessary to induce LTP is more than 500 nM, suggesting that some other functions of MCD are also fundamental to LTP induction. The concentration of MCD required for LTP induction was greatly reduced by preactivating G proteins. This fact suggests that G protein activation by MCD also plays an important role in LTP induction. MCD-binding proteins were purified from rat brain. G proteins were found to exist in a non-denatured state in this affinity-purified fraction. When reconstituted into a planar lipid bilayer membrane, a potassium-selective and voltage-dependent current could be observed. This channel was blocked by MCD at a high concentration equal to the effective concentration for G protein activation. Addition of GTP-gamma-S significantly blocked the reconstituted current. Thus, we identified a pathway for LTP induction by MCD in which high concentrations of MCD activate G protein which in turns leads to blocking of a potassium channel.
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Affiliation(s)
- I Fujimoto
- Department of Physiology, Nagoya City University Medical School, Japan
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Rison RA, Stanton PK. Long-term potentiation and N-methyl-D-aspartate receptors: foundations of memory and neurologic disease? Neurosci Biobehav Rev 1995; 19:533-52. [PMID: 8684715 DOI: 10.1016/0149-7634(95)00017-8] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Understanding the physiology of learning and memory is one of the great challenges of neuroscience. The discovery in recent years of long-term potentiation (LTP) of synaptic transmission and the elaboration of the mechanisms involved, in particular the NMDA receptor, offers the prospect not only of improving our understanding of normal memory storage and retrieval, but may also yield insights about various neurological and psychiatric clinical disorders. In this review, we begin by examining the different forms, properties, and methods of inducing LTP, followed by a description of molecular mechanisms thought to underlie the phenomenon. Molecular structure of the receptor is discussed, along with the roles of Ca2+ second messenger systems, synaptic morphology changes, and retrograde messengers in LTP. Finally, implications of the NMDA receptor and LTP in learning, memory, and certain clinical conditions such as epilepsy, Alzheimer's disease, and schizophrenia are discussed.
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Toral J, Hu W, Critchett D, Solomon AJ, Barrett JE, Sokol PT, Ziai MR. 5-HT3 receptor-independent inhibition of the depolarization-induced 86Rb efflux from human neuroblastoma cells, TE671, by ondansetron. J Pharm Pharmacol 1995; 47:618-22. [PMID: 8568632 DOI: 10.1111/j.2042-7158.1995.tb06725.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The 5-HT3-receptor antagonist, ondansetron, has been shown to have positive effects in selected in-vivo models of memory impairment and anxiety. The exact mechanisms underlying such bioactivities are unknown. In the present work, an 86Rb efflux bioassay was used to show that ondansetron has a unique ability to block voltage-gated potassium channels in TE671 human neuroblastoma cells. This intrinsic potassium-channel-blocking (KCB) property is relatively weak (IC50 20 microM), but is not shared by other 5-HT3-receptor ligands including zatosetron, MDL 72222, LY 278, 584, zacopride, 1-phenylbiguanide, and ICS 205-930 (tropisetron). Pre-incubation of the target neuroblastoma cells with several 5-HT-receptor ligands including 5-hydroxytryptamine, 8-OH-DPAT, ketanserin, 2-methyl-5-HT, as well as a number of potent 5-HT3 agonists and antagonists and two selective neurotoxins, failed to abolish the KCB action of ondansetron. A preliminary structure-activity relationship analysis indicates that the KCB activity of ondansetron is almost entirely attributable to its structural nucleus, 2,3-dihyro-9-methyl-4(1H)-carbazolone. It is hypothesized that the KCB action of ondansetron is mediated through receptors other than 5-HT3 receptors. The KCB activity of ondansetron may be a significant factor in the in-vivo cognition-enhancing activities of this compound, conceivably due to depolarization of the hippocampal synaptic membranes and a consequent augmentation of neurotransmission.
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Affiliation(s)
- J Toral
- CV/CNS Research Section, American Cyanamid Company, Lederle Laboratories, Pearl River, New York 10965, USA
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Murakami N, Sakai N, Nei K, Matsuyama S, Saito N, Tanaka C. Potassium and calcium channel involvement in induction of long-lasting synaptic enhancement by calyculin A, a protein phosphatase inhibitor, in rat hippocampal CA1 region. Neurosci Lett 1994; 176:181-4. [PMID: 7830942 DOI: 10.1016/0304-3940(94)90077-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In the Schaffer collateral-CA1 pathway in rat hippocampal slices, exposure to calyculin A induced a long-lasting potentiation of the extracellular field potentials with a transient increase in glutamate release. The synaptic enhancement produced by calyculin A was blocked by staurosporine and nicardipine, but not by D,L-2-amino-5-phosphonovalerate. In dissociated CA1 pyramidal cells, calyculin A blocked the action-potential repolarization and fast after-hyperpolarization, and increased spike frequency. These results suggest that calyculin A-induced long-lasting potentiation is triggered by the blockade of Ca(2+)-activated K+ channels, the transient increase of glutamate release and the consequent activation of voltage-gated Ca2+ channels, and is maintained by increases in protein kinases activities.
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Affiliation(s)
- N Murakami
- Department of Pharmacology, Kobe University School of Medicine, Japan
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