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Xi C, Shi X, Wang Y, He J, Jiang S, Niu B, Chen Y, Zhao F, Cao Z. Influence of bifenthrin exposure at different gestational stages on the neural development. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 263:115365. [PMID: 37597292 DOI: 10.1016/j.ecoenv.2023.115365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/28/2023] [Accepted: 08/10/2023] [Indexed: 08/21/2023]
Abstract
Perinatal exposure to bifenthrin (BF) alters neurodevelopment. However, the most susceptible time period to BF exposure and the possible mechanisms are not clear. In the current study, pregnant female mice were treated with BF (0.5 mg/kg/d) at three different stages [gestational day (GD) 0-5, 6-15 and 16-birth (B)] and neurologic deficits were evaluated in offspring mice. BF exposure at GD 16-B significantly altered the locomotor activity and caused learning and memory impairments in 6-week-old offspring. Gestational BF exposure also caused neuronal loss in the region of cornu ammonis of hippocampi of 6-week-old offspring. Interestingly, neurobehavioral impairments and neuronal loss were not observed in offspring at 10-week-old. BF exposure at GD 16-B also decreased protein levels of VGluT1, NR1 and NR2A while increased the protein levels of NR2B and VGAT1, as well as the gene levels of Il-1β, Il-6 and Tnf-α in hippocampi of 6-week-old offspring. Collectively, these data demonstrate that gestational exposure to a low dose BF causes neurodevelopmental deficits that remit with the age and the late-stage of pregnancy is the most susceptible time window to BF exposure. Imbalance in excitatory/inhibitory neuronal transmission, altered expression levels of NMDA receptors and increased neural inflammation may be associated with BF prenatal exposure-triggered neurobehavioral impairments.
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Affiliation(s)
- Chuchu Xi
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China
| | - Xiaoqian Shi
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China
| | - Yujing Wang
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China
| | - Jing He
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China
| | - Shan Jiang
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China
| | - Bo Niu
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China
| | - Ying Chen
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China
| | - Fang Zhao
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China.
| | - Zhengyu Cao
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China.
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Mehrotra S, Pierce ML, Dravid SM, Murray TF. Stimulation of Neurite Outgrowth in Cerebrocortical Neurons by Sodium Channel Activator Brevetoxin-2 Requires Both N-Methyl-D-aspartate Receptor 2B (GluN2B) and p21 Protein (Cdc42/Rac)-Activated Kinase 1 (PAK1). Mar Drugs 2022; 20:559. [PMID: 36135748 PMCID: PMC9504648 DOI: 10.3390/md20090559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/25/2022] [Accepted: 08/28/2022] [Indexed: 12/05/2022] Open
Abstract
N-methyl-D-aspartate (NMDA) receptors play a critical role in activity-dependent dendritic arborization, spinogenesis, and synapse formation by stimulating calcium-dependent signaling pathways. Previously, we have shown that brevetoxin 2 (PbTx-2), a voltage-gated sodium channel (VGSC) activator, produces a concentration-dependent increase in intracellular sodium [Na+]I and increases NMDA receptor (NMDAR) open probabilities and NMDA-induced calcium (Ca2+) influxes. The objective of this study is to elucidate the downstream signaling mechanisms by which the sodium channel activator PbTx-2 influences neuronal morphology in murine cerebrocortical neurons. PbTx-2 and NMDA triggered distinct Ca2+-influx pathways, both of which involved the NMDA receptor 2B (GluN2B). PbTx-2-induced neurite outgrowth in day in vitro 1 (DIV-1) neurons required the small Rho GTPase Rac1 and was inhibited by both a PAK1 inhibitor and a PAK1 siRNA. PbTx-2 exposure increased the phosphorylation of PAK1 at Thr-212. At DIV-5, PbTx-2 induced increases in dendritic protrusion density, p-cofilin levels, and F-actin throughout the dendritic arbor and soma. Moreover, PbTx-2 increased miniature excitatory post-synaptic currents (mEPSCs). These data suggest that the stimulation of neurite outgrowth, spinogenesis, and synapse formation produced by PbTx-2 are mediated by GluN2B and PAK1 signaling.
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Affiliation(s)
- Suneet Mehrotra
- Department of Pharmacology and Neuroscience, School of Medicine, Creighton University, Omaha, NE 68178, USA
- Omeros, Seattle, WA 98119, USA
| | - Marsha L. Pierce
- Department of Pharmacology and Neuroscience, School of Medicine, Creighton University, Omaha, NE 68178, USA
- Department of Pharmacology, College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA
| | - Shashank M. Dravid
- Department of Pharmacology and Neuroscience, School of Medicine, Creighton University, Omaha, NE 68178, USA
| | - Thomas F. Murray
- Department of Pharmacology and Neuroscience, School of Medicine, Creighton University, Omaha, NE 68178, USA
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Xi C, Yang Z, Yu Y, Li S, He J, El-Aziz TMA, Zhao F, Cao Z. Influence of perinatal deltamethrin exposure at distinct developmental stages on motor activity, learning and memory. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 236:113460. [PMID: 35378399 DOI: 10.1016/j.ecoenv.2022.113460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/12/2022] [Accepted: 03/25/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Perinatal exposure to deltamethrin (DM) causes attention-deficit/ hyperactivity disorder-like behaviors. However, the vulnerable time window to DM exposure and the possible mechanism are obscure. We aimed to identify the critical window(s) at perinatal stages for DM exposure and the possible mechanism. METHOD Pregnant mice were exposed to DM (0.5 mg/kg) at three different prenatal stages [gestational day (GD) 0-5, 6-15 and 16-birth (16-B)] and early postnatal stage (PD 0-10). Locomotor activity, learning and memory were evaluated using open field and Y-maze test, respectively. Nissl staining and western blots were used to examine the neuronal loss and the protein expression, respectively. RESULTS Perinatal exposures to DM had no effect on reproductive and growth index of offspring. However, mice receiving DM exposure during GD 16-B displayed significantly higher mortality suggesting GD 16-B is the most vulnerable time window to DM exposure. Prenatal but not early postnatal DM exposure impaired locomotor activity, learning and memory, and caused neuron loss in the dentate gyrus of male offspring. However, neither prenatal nor postnatal DM exposure affected mouse behavior of female offspring. Prenatal DM exposures decreased the protein levels of NR2A and NR2B in both hippocampi and cerebral cortices of male offspring. However, female mice receiving DM exposure at GD 16-B but not other stages displayed increased expression levels of NR2A and NR2B in hippocampi. CONCLUSION Prenatal but not early postnatal DM exposure impairs the neuron development in male but not female mice. Altered NMDA receptor expression may correlate to DM-induced behavioral deficits.
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Affiliation(s)
- Chuchu Xi
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China.
| | - Zhao Yang
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China.
| | - Yiyi Yu
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China.
| | - Shaoheng Li
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China.
| | - Jing He
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China.
| | - Tarek Mohamed Abd El-Aziz
- Zoology Department, Faculty of Science, Minia University, El-Minia 61519, Egypt; Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA.
| | - Fang Zhao
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China.
| | - Zhengyu Cao
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu 211198, PR China.
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Mehrotra S, Pierce ML, Cao Z, Jabba SV, Gerwick WH, Murray TF. Antillatoxin-Stimulated Neurite Outgrowth Involves the Brain-Derived Neurotrophic Factor (BDNF) - Tropomyosin Related Kinase B (TrkB) Signaling Pathway. JOURNAL OF NATURAL PRODUCTS 2022; 85:562-571. [PMID: 35239341 PMCID: PMC9245549 DOI: 10.1021/acs.jnatprod.1c01001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Voltage-gated sodium channel (VGSC) activators promote neurite outgrowth by augmenting intracellular Na+ concentration ([Na+]i) and upregulating N-methyl-d-aspartate receptor (NMDAR) function. NMDAR activation stimulates calcium (Ca2+) influx and increases brain-derived neurotrophic factor (BDNF) release and activation of tropomyosin receptor kinase B (TrkB) signaling. The BDNF-TrkB pathway has been implicated in activity-dependent neuronal development. We have previously shown that antillatoxin (ATX), a novel lipopeptide isolated from the cyanobacterium Moorea producens, is a VGSC activator that produces an elevation of [Na+]i. Here we address the effect of ATX on the synthesis and release of BDNF and determine the signaling mechanisms by which ATX enhances neurite outgrowth in immature cerebrocortical neurons. ATX treatment produced a concentration-dependent release of BDNF. Acute treatment with ATX also resulted in increased synthesis of BDNF. ATX stimulation of neurite outgrowth was prevented by pretreatment with a TrkB inhibitor or transfection with a dominant-negative Trk-B. The ATX activation of TrkB and Akt was blocked by both a NMDAR antagonist (MK-801) and a VGSC blocker (tetrodotoxin). These results suggest that VGSC activators such as the structurally novel ATX may represent a new pharmacological strategy to promote neuronal plasticity through a NMDAR-BDNF-TrkB-dependent mechanism.
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Affiliation(s)
- Suneet Mehrotra
- Omeros, 201 Elliott Ave. West, Seattle, Washington 98119, United States
| | - Marsha L Pierce
- Department of Pharmacology, College of Graduate Studies, Midwestern University, Downers Grove, Illinois 60515, United States
| | - Zhengyu Cao
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China
| | - Sairam V Jabba
- Department of Anesthesiology, Duke University School of Medicine, Durham, North Carolina 27710, United States
| | - William H Gerwick
- Center for Marine Biotech and Biomedicine, Scripps Institute of Oceanography, University of California at San Diego, San Diego, California 92093-0212, United States
| | - Thomas F Murray
- Department of Pharmacology and Neuroscience, School of Medicine, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
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Voltage-Gated Sodium Channels: A Prominent Target of Marine Toxins. Mar Drugs 2021; 19:md19100562. [PMID: 34677461 PMCID: PMC8537899 DOI: 10.3390/md19100562] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 09/29/2021] [Accepted: 10/02/2021] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs) are considered to be one of the most important ion channels given their remarkable physiological role. VGSCs constitute a family of large transmembrane proteins that allow transmission, generation, and propagation of action potentials. This occurs by conducting Na+ ions through the membrane, supporting cell excitability and communication signals in various systems. As a result, a wide range of coordination and physiological functions, from locomotion to cognition, can be accomplished. Drugs that target and alter the molecular mechanism of VGSCs’ function have highly contributed to the discovery and perception of the function and the structure of this channel. Among those drugs are various marine toxins produced by harmful microorganisms or venomous animals. These toxins have played a key role in understanding the mode of action of VGSCs and in mapping their various allosteric binding sites. Furthermore, marine toxins appear to be an emerging source of therapeutic tools that can relieve pain or treat VGSC-related human channelopathies. Several studies documented the effect of marine toxins on VGSCs as well as their pharmaceutical applications, but none of them underlined the principal marine toxins and their effect on VGSCs. Therefore, this review aims to highlight the neurotoxins produced by marine animals such as pufferfish, shellfish, sea anemone, and cone snail that are active on VGSCs and discuss their pharmaceutical values.
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Li Y, Yu HB, Zhang Y, Leao T, Glukhov E, Pierce ML, Zhang C, Kim H, Mao HH, Fang F, Cottrell GW, Murray TF, Gerwick L, Guan H, Gerwick WH. Pagoamide A, a Cyclic Depsipeptide Isolated from a Cultured Marine Chlorophyte, Derbesia sp., Using MS/MS-Based Molecular Networking. JOURNAL OF NATURAL PRODUCTS 2020; 83:617-625. [PMID: 31916778 PMCID: PMC7210564 DOI: 10.1021/acs.jnatprod.9b01019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A thiazole-containing cyclic depsipeptide with 11 amino acid residues, named pagoamide A (1), was isolated from laboratory cultures of a marine Chlorophyte, Derbesia sp. This green algal sample was collected from America Samoa, and pagoamide A was isolated using guidance by MS/MS-based molecular networking. Cultures were grown in a light- and temperature-controlled environment and harvested after several months of growth. The planar structure of pagoamide A (1) was characterized by detailed 1D and 2D NMR experiments along with MS and UV analysis. The absolute configurations of its amino acid residues were determined by advanced Marfey's analysis following chemical hydrolysis and hydrazinolysis reactions. Two of the residues in pagoamide A (1), phenylalanine and serine, each occurred twice in the molecule, once in the d- and once in the l-configuration. The biosynthetic origin of pagoamide A (1) was considered in light of other natural products investigations with coenocytic green algae.
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Affiliation(s)
- Yueying Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, People’s Republic of China
- University of California, San Diego, La Jolla, California 92093, United States
| | - Hao-Bing Yu
- University of California, San Diego, La Jolla, California 92093, United States
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Second Military Medical University, Shanghai 200433, People’s Republic of China
| | - Yi Zhang
- University of California, San Diego, La Jolla, California 92093, United States
- College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, People’s Republic of China
| | - Tiago Leao
- University of California, San Diego, La Jolla, California 92093, United States
| | - Evgenia Glukhov
- University of California, San Diego, La Jolla, California 92093, United States
| | - Marsha L. Pierce
- Department of Pharmacology, School of Medicine, Creighton University, Omaha, Nebraska 68178, United States
| | - Chen Zhang
- University of California, San Diego, La Jolla, California 92093, United States
- Department of Computer Sciences and Engineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Hyunwoo Kim
- University of California, San Diego, La Jolla, California 92093, United States
| | - Huanru Henry Mao
- Department of Computer Sciences and Engineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Fang Fang
- University of California, San Diego, La Jolla, California 92093, United States
| | - Garrison W. Cottrell
- Department of Computer Sciences and Engineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Thomas F. Murray
- Department of Pharmacology, School of Medicine, Creighton University, Omaha, Nebraska 68178, United States
| | - Lena Gerwick
- University of California, San Diego, La Jolla, California 92093, United States
| | - Huashi Guan
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, People’s Republic of China
| | - William H. Gerwick
- University of California, San Diego, La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
- To whom correspondence should be addressed. Tel: (858)-534-0578.
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Ayvazyan NM, O'Leary VB, Dolly JO, Ovsepian SV. Neurobiology and therapeutic utility of neurotoxins targeting postsynaptic mechanisms of neuromuscular transmission. Drug Discov Today 2019; 24:1968-1984. [PMID: 31247153 DOI: 10.1016/j.drudis.2019.06.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 05/15/2019] [Accepted: 06/17/2019] [Indexed: 11/28/2022]
Abstract
The neuromuscular junction (NMJ) is the principal site for the translation of motor neurochemical signals to muscle activity. Therefore, the release and sensing machinery of acetylcholine (ACh) along with muscle contraction are two of the main targets of natural toxins and pathogens, causing paralysis. Given pharmacology and medical advances, the active ingredients of toxins that target postsynaptic mechanisms have become of major interest, showing promise as drug leads. Herein, we review key facets of prevalent toxins modulating the mechanisms of ACh sensing and generation of the postsynaptic response, with muscle contraction. We consider the correlation between their outstanding selectivity and potency plus effects on motor function, and discuss emerging data advocating their usage for the development of therapies alleviating neuromuscular dysfunction.
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Affiliation(s)
- Naira M Ayvazyan
- Orbeli Institute of Physiology, National Academy of Sciences of the Republic of Armenia, Yerevan, Armenia.
| | - Valerie B O'Leary
- Department of Medical Genetics, Third Faculty of Medicine, Charles University, Ruská 87, 100 00, Praha 10, Czech Republic
| | - J Oliver Dolly
- International Centre for Neurotherapeutics, Dublin City University, Dublin, Ireland
| | - Saak V Ovsepian
- International Centre for Neurotherapeutics, Dublin City University, Dublin, Ireland; The National Institute of Mental Health, Topolová 748, Klecany, Czech Republic; Department of Psychiatry and Medical Psychology, Third Faculty of Medicine, Charles University, Ruská 87, 100 00, Praha 10, Czech Republic.
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Shen L, Yang Q, He Y, Zou X, Cao Z. BmK NT1-induced neurotoxicity is mediated by PKC/CaMKⅡ-dependent ERK1/2 and p38 activation in primary cultured cerebellar granule cells. Toxicology 2019; 421:22-29. [PMID: 30940546 DOI: 10.1016/j.tox.2019.03.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 03/01/2019] [Accepted: 03/28/2019] [Indexed: 01/08/2023]
Abstract
Voltage-gated sodium channels (VGSCs) represent molecular targets for a number of potent neurotoxins that affect the ion permeation or gating kinetics. BmK NT1, an α-scorpion toxin purified from Buthus martensii Karch (BMK), induces excitatory neurotoxicity by activation of VGSCs with subsequent overloading of intracellular Ca2+ in cerebellar granule cells (CGCs). In the current study, we further investigated signaling pathways responsible for BmK NT1-induced neurotoxicity in CGCs. BmK NT1 exposure induced neuronal death in different development stages of CGCs with similar potencies ranging from 0.21-0.48 μM. The maximal neuronal death induced by BmK NT1 gradually increased from 25.6% at 7 days in vitro (DIVs) to 42.1%, 47.8%, and 67.2% at 10, 13, and 16 DIVs, respectively, suggesting that mature CGCs are more vulnerable to BmK NT1 exposure. Application of Ca2+/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) inhibitors, KN-62 or KN-93, but not Ca2+/calmodulin-dependent protein kinase kinase (CaMKK) inhibitor, STO-609, completely abolished BmK NT1-induced neuronal death. Moreover, BmK NT1 exposure stimulated CaMKⅡ phosphorylation. BmK NT1 also stimulated extracellular regulated protein kinases 1/2 (ERK1/2) and p38 phosphorylation which was abolished by tetrodotoxin demonstrating the role of VGSCs on BmK NT1-induced ERK1/2 and p38 phosphorylation. However, BmK NT1 didn't affect c-Jun N-terminal kinase (JNK) phosphorylation. In addition, both ERK1/2 inhibitor, U0126 and p38 inhibitor, SB203580 attenuated BmK NT1-induced neuronal death. Both PKC inhibitor, Gö 6983 and CaMKⅡ inhibitor, KN-62 abolished BmK NT1-induced ERK1/2 and p38 phosphorylation. Considered together, these data demonstrate that BmK NT1-induced neurotoxicity is through PKC/CaMKⅡ mediated ERK1/2 and p38 activation.
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Affiliation(s)
- Liping Shen
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Qundi Yang
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Yuwei He
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Xiaohan Zou
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China.
| | - Zhengyu Cao
- State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China.
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9
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Yang F, Liu S, Zhang Y, Qin C, Xu L, Li W, Cao Z, Li W, Wu Y. Expression of recombinant α-toxin BmKM9 from scorpion Buthus martensii Karsch and its functional characterization on sodium channels. Peptides 2018; 99:153-160. [PMID: 28986244 DOI: 10.1016/j.peptides.2017.09.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 09/15/2017] [Accepted: 09/27/2017] [Indexed: 12/19/2022]
Abstract
Scorpion toxins are invaluable pharmacological tools for studying ion channels and potential drugs for channelopathies. The long-chain toxins from scorpion venom with four disulfide bridges exhibit their unusual bioactivity or biotoxicity by acting on the sodium channels. However, the functional properties of most toxins are still unclear due to their tiny amounts in crude venom and their challenging production by chemical and gene engineering techniques. Here, we expressed one of the long-chain α-toxins, BmKM9, found in the venom of the scorpion Buthus martensii Karsch and characterized its pharmacological properties on sodium channels. Unlike previous toxin production, the recombinant BmKM9 (rBmKM9) possessed no additional amino acid residues such as the His-tag and thrombin cleavage site. The refolded toxin could inhibit the inactivation of rNav1.4, hNav1.5 and hNav1.7 sodium channels. Dose-response experiments were further conducted on these channels. The calculated EC50 values were 131.7±6.6nM for rNav1.4, 454.2±50.1nM for hNav1.5 and 30.9±10.3μM for hNav1.7. The channel activation experiments indicated that the rBmKM9 toxin could shift the activation curves of rNav1.4 and hNav1.5 channels toward a more negative direction and present the typical features of a β-toxin. However, instead of the same activation property on sodium channels, the rBmKM9 toxin could result in different inactivation shift capabilities on rNav1.4 and hNav1.5 channels. The V1/2 values of the steady-state inactivation were altered to be more positive for rNav1.4 and more negative for hNav1.5. Moreover, the recovery of the hNav1.5 channel from inactivation was more significantly delayed than that of the rNav1.4 channel by exposure to rBmKM9. Together, these findings highlighted that the rBmKM9 toxin presents the pharmacological properties of both α- and β-toxins, which would increase the challenge to the classical classification of scorpion toxins. Furthermore, the expression method and functional information on sodium channels would promote the potential application of toxins and contribute to further channel structural and functional studies.
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Affiliation(s)
- Fan Yang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Shuang Liu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yaoyun Zhang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Chenhu Qin
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Lingna Xu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Wenhua Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Biodrug Research Center, Wuhan University, Wuhan 430072, China
| | - Zhijian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Biodrug Research Center, Wuhan University, Wuhan 430072, China
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Biodrug Research Center, Wuhan University, Wuhan 430072, China.
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Biodrug Research Center, Wuhan University, Wuhan 430072, China.
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Abstract
Voltage-gated sodium channels (VGSCs) are critical in generation and conduction of electrical signals in multiple excitable tissues. Natural toxins, produced by animal, plant, and microorganisms, target VGSCs through diverse strategies developed over millions of years of evolutions. Studying of the diverse interaction between VGSC and VGSC-targeting toxins has been contributing to the increasing understanding of molecular structure and function, pharmacology, and drug development potential of VGSCs. This chapter aims to summarize some of the current views on the VGSC-toxin interaction based on the established receptor sites of VGSC for natural toxins.
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Affiliation(s)
- Yonghua Ji
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai, China.
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Assunção J, Guedes AC, Malcata FX. Biotechnological and Pharmacological Applications of Biotoxins and Other Bioactive Molecules from Dinoflagellates. Mar Drugs 2017; 15:E393. [PMID: 29261163 PMCID: PMC5742853 DOI: 10.3390/md15120393] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/12/2017] [Accepted: 12/15/2017] [Indexed: 12/26/2022] Open
Abstract
The long-lasting interest in bioactive molecules (namely toxins) produced by (microalga) dinoflagellates has risen in recent years. Exhibiting wide diversity and complexity, said compounds are well-recognized for their biological features, with great potential for use as pharmaceutical therapies and biological research probes. Unfortunately, provision of those compounds is still far from sufficient, especially in view of an increasing demand for preclinical testing. Despite the difficulties to establish dinoflagellate cultures and obtain reasonable productivities of such compounds, intensive research has permitted a number of advances in the field. This paper accordingly reviews the characteristics of some of the most important biotoxins (and other bioactive substances) produced by dinoflagellates. It also presents and discusses (to some length) the main advances pertaining to dinoflagellate production, from bench to large scale-with an emphasis on material published since the latest review available on the subject. Such advances encompass improvements in nutrient formulation and light supply as major operational conditions; they have permitted adaptation of classical designs, and aided the development of novel configurations for dinoflagellate growth-even though shearing-related issues remain a major challenge.
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Affiliation(s)
- Joana Assunção
- LEPABE-Laboratory of Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
| | - A Catarina Guedes
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, s/n, P-4450-208 Matosinhos, Portugal.
| | - F Xavier Malcata
- LEPABE-Laboratory of Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
- Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
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12
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Naman CB, Almaliti J, Armstrong L, Caro-Díaz EJ, Pierce ML, Glukhov E, Fenner A, Spadafora C, Debonsi HM, Dorrestein PC, Murray TF, Gerwick WH. Discovery and Synthesis of Caracolamide A, an Ion Channel Modulating Dichlorovinylidene Containing Phenethylamide from a Panamanian Marine Cyanobacterium cf. Symploca Species. JOURNAL OF NATURAL PRODUCTS 2017; 80:2328-2334. [PMID: 28783331 DOI: 10.1021/acs.jnatprod.7b00367] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A recent untargeted metabolomics investigation into the chemical profile of 10 organic extracts from cf. Symploca spp. revealed several interesting chemical leads for further natural product drug discovery. Subsequent target-directed isolation efforts with one of these, a Panamanian marine cyanobacterium cf. Symploca sp., yielded a phenethylamide metabolite that terminates in a relatively rare gem-dichlorovinylidene moiety, caracolamide A (1), along with a known isotactic polymethoxy-1-alkene (2). Detailed NMR and HRESIMS analyses were used to determine the structures of these molecules, and compound 1 was confirmed by a three-step synthesis. Pure compound 1 was shown to have in vitro calcium influx and calcium channel oscillation modulatory activity when tested as low as 10 pM using cultured murine cortical neurons, but was not cytotoxic to NCI-H460 human non-small-cell lung cancer cells in vitro (IC50 > 10 μM).
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Affiliation(s)
- C Benjamin Naman
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego , La Jolla, California 92093, United States
| | - Jehad Almaliti
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego , La Jolla, California 92093, United States
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, The University of Jordan , Amman, 11942, Jordan
| | - Lorene Armstrong
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego , La Jolla, California 92093, United States
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo , Avenida Do Café, s/n, Campus Universitário, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Eduardo J Caro-Díaz
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego , La Jolla, California 92093, United States
| | - Marsha L Pierce
- Department of Pharmacology, Creighton University School of Medicine , 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Evgenia Glukhov
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego , La Jolla, California 92093, United States
| | - Amanda Fenner
- Center of Cellular and Molecular Biology of Diseases, City of Knowledge, Instituto de Investigaciones Científicas y Sevicios de Alta Tecnología , Bldg. 219, P.O. Box 7250, Panama 5, Republic of Panama
| | - Carmenza Spadafora
- Center of Cellular and Molecular Biology of Diseases, City of Knowledge, Instituto de Investigaciones Científicas y Sevicios de Alta Tecnología , Bldg. 219, P.O. Box 7250, Panama 5, Republic of Panama
| | - Hosana M Debonsi
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo , Avenida Do Café, s/n, Campus Universitário, CEP 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Pieter C Dorrestein
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego , La Jolla, California 92093, United States
| | - Thomas F Murray
- Department of Pharmacology, Creighton University School of Medicine , 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - William H Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego , La Jolla, California 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego , La Jolla, California 92093, United States
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13
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Veratridine produces distinct calcium response profiles in mouse Dorsal Root Ganglia neurons. Sci Rep 2017; 7:45221. [PMID: 28338073 PMCID: PMC5364547 DOI: 10.1038/srep45221] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/20/2017] [Indexed: 12/21/2022] Open
Abstract
Nociceptors are a subpopulation of dorsal root ganglia (DRG) neurons that detect noxious stimuli and signal pain. Veratridine (VTD) is a voltage-gated sodium channel (VGSC) modifier that is used as an "agonist" in functional screens for VGSC blockers. However, there is very little information on VTD response profiles in DRG neurons and how they relate to neuronal subtypes. Here we characterised VTD-induced calcium responses in cultured mouse DRG neurons. Our data shows that the heterogeneity of VTD responses reflects distinct subpopulations of sensory neurons. About 70% of DRG neurons respond to 30-100 μM VTD. We classified VTD responses into four profiles based upon their response shape. VTD response profiles differed in their frequency of occurrence and correlated with neuronal size. Furthermore, VTD response profiles correlated with responses to the algesic markers capsaicin, AITC and α, β-methylene ATP. Since VTD response profiles integrate the action of several classes of ion channels and exchangers, they could act as functional "reporters" for the constellation of ion channels/exchangers expressed in each sensory neuron. Therefore our findings are relevant to studies and screens using VTD to activate DRG neurons.
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14
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Philkhana SC, Mehrotra S, Murray TF, Reddy DS. Synthesis and biological evaluation of palmyrolide A macrocycles as sodium channel blockers towards neuroprotection. Org Biomol Chem 2016; 14:8457-73. [PMID: 27536802 DOI: 10.1039/c6ob01372d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Palmyrolide A is a neuroprotective macrolide isolated by Gerwick and coworkers in 2010. This natural product is known to suppress neuronal spontaneous calcium ion oscillations through its voltage-gated sodium channel blocking ability which is of significant interest in CNS drug discovery. Herein, we give a detailed account on total synthesis of (+)-palmyrolide A and synthesis of a focused library of macrocycles around the scaffold, followed by their biological evaluation. Use of the chiral pool approach, Zhu's oxidative homologation, access to unnatural cis-palmyrolide A, preparation of 18 new analogues and identification of macrolides with improved sodium channel blocking activity are the important features of the present paper. As a measure of potency as voltage-gated sodium channel blockers, all the synthesized analogues were profiled for their ability to inhibit the veratridine-stimulated Na(+) influx in murine primary neuronal cultures. Four macrocycles were found to be more potent or comparable to that of the natural product (-)-palmyrolide A. The most potent compound from this series 20 was structurally simplified and readily accessible in good quantities for further biological profiling.
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15
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He Y, Zou X, Li X, Chen J, Jin L, Zhang F, Yu B, Cao Z. Activation of sodium channels by α-scorpion toxin, BmK NT1, produced neurotoxicity in cerebellar granule cells: an association with intracellular Ca 2+ overloading. Arch Toxicol 2016; 91:935-948. [PMID: 27318804 DOI: 10.1007/s00204-016-1755-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 06/08/2016] [Indexed: 12/13/2022]
Abstract
Voltage-gated sodium channels (VGSCs) are responsible for the action potential generation in excitable cells including neurons and involved in many physiological and pathological processes. Scorpion toxins are invaluable tools to explore the structure and function of ion channels. BmK NT1, a scorpion toxin from Buthus martensii Karsch, stimulates sodium influx in cerebellar granule cells (CGCs). In this study, we characterized the mode of action of BmK NT1 on the VGSCs and explored the cellular response in CGC cultures. BmK NT1 delayed the fast inactivation of VGSCs, increased the Na+ currents, and shifted the steady-state activation and inactivation to more hyperpolarized membrane potential, which was similar to the mode of action of α-scorpion toxins. BmK NT1 stimulated neuron death (EC50 = 0.68 µM) and produced massive intracellular Ca2+ overloading (EC50 = 0.98 µM). TTX abrogated these responses, suggesting that both responses were subsequent to the activation of VGSCs. The Ca2+ response of BmK NT1 was primary through extracellular Ca2+ influx since reducing the extracellular Ca2+ concentration suppressed the Ca2+ response. Further pharmacological evaluation demonstrated that BmK NT1-induced Ca2+ influx and neurotoxicity were partially blocked either by MK-801, an NMDA receptor blocker, or by KB-R7943, an inhibitor of Na+/Ca2+ exchangers. Nifedipine, an L-type Ca2+ channel inhibitor, slightly suppressed both Ca2+ response and neurotoxicity. A combination of these three inhibitors abrogated both responses. Considered together, these data ambiguously demonstrated that activation of VGSCs by an α-scorpion toxin was sufficient to produce neurotoxicity which was associated with intracellular Ca2+ overloading through both NMDA receptor- and Na+/Ca2+ exchanger-mediated Ca2+ influx.
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Affiliation(s)
- Yuwei He
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China.,Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China
| | - Xiaohan Zou
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China.,Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China
| | - Xichun Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China.,Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China
| | - Juan Chen
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China.,Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China
| | - Liang Jin
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China.,School of Biological Pharmaceutics, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China
| | - Fan Zhang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China. .,Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China.
| | - Boyang Yu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China.,Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China
| | - Zhengyu Cao
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China. .,Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, 211198, Jiangsu, People's Republic of China.
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16
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Zhao F, Li X, Jin L, Zhang F, Inoue M, Yu B, Cao Z. Development of a Rapid Throughput Assay for Identification of hNav1.7 Antagonist Using Unique Efficacious Sodium Channel Agonist, Antillatoxin. Mar Drugs 2016; 14:md14020036. [PMID: 26891306 PMCID: PMC4771989 DOI: 10.3390/md14020036] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 01/21/2016] [Accepted: 01/26/2016] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs) are responsible for the generation of the action potential. Among nine classified VGSC subtypes (Nav1.1–Nav1.9), Nav1.7 is primarily expressed in the sensory neurons, contributing to the nociception transmission. Therefore Nav1.7 becomes a promising target for analgesic drug development. In this study, we compared the influence of an array of VGSC agonists including veratridine, BmK NT1, brevetoxin-2, deltamethrin and antillatoxin (ATX) on membrane depolarization which was detected by Fluorescence Imaging Plate Reader (FLIPR) membrane potential (FMP) blue dye. In HEK-293 cells heterologously expressing hNav1.7 α-subunit, ATX produced a robust membrane depolarization with an EC50 value of 7.8 ± 2.9 nM whereas veratridine, BmK NT1, and deltamethrin produced marginal response. Brevetoxin-2 was without effect on membrane potential change. The ATX response was completely inhibited by tetrodotoxin suggesting that the ATX response was solely derived from hNav1.7 activation, which was consistent with the results where ATX produced a negligible response in null HEK-293 cells. Six VGSC antagonists including lidocaine, lamotrigine, phenytoin, carbamazepine, riluzole, and 2-amino-6-trifluoromethylthiobenzothiazole all concentration-dependently inhibited ATX response with IC50 values comparable to that reported from patch-clamp experiments. Considered together, we demonstrate that ATX is a unique efficacious hNav1.7 activator which offers a useful probe to develop a rapid throughput screening assay to identify hNav1.7 antagonists.
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Affiliation(s)
- Fang Zhao
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China.
- Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China.
| | - Xichun Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China.
- Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China.
| | - Liang Jin
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China.
- School of Life Science and Technology, China Pharmaceutical University, Nanjing 211198, China.
| | - Fan Zhang
- Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China.
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
| | - Boyang Yu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China.
- Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China.
| | - Zhengyu Cao
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China.
- Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China.
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17
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Zou X, He Y, Qiao J, Zhang C, Cao Z. The natural scorpion peptide, BmK NT1 activates voltage-gated sodium channels and produces neurotoxicity in primary cultured cerebellar granule cells. Toxicon 2016; 109:33-41. [DOI: 10.1016/j.toxicon.2015.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 09/15/2015] [Accepted: 11/05/2015] [Indexed: 11/26/2022]
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18
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Boudreau PD, Monroe EA, Mehrotra S, Desfor S, Korobeynikov A, Sherman DH, Murray TF, Gerwick L, Dorrestein PC, Gerwick WH. Expanding the Described Metabolome of the Marine Cyanobacterium Moorea producens JHB through Orthogonal Natural Products Workflows. PLoS One 2015. [PMID: 26222584 PMCID: PMC4519256 DOI: 10.1371/journal.pone.0133297] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Moorea producens JHB, a Jamaican strain of tropical filamentous marine cyanobacteria, has been extensively studied by traditional natural products techniques. These previous bioassay and structure guided isolations led to the discovery of two exciting classes of natural products, hectochlorin (1) and jamaicamides A (2) and B (3). In the current study, mass spectrometry-based 'molecular networking' was used to visualize the metabolome of Moorea producens JHB, and both guided and enhanced the isolation workflow, revealing additional metabolites in these compound classes. Further, we developed additional insight into the metabolic capabilities of this strain by genome sequencing analysis, which subsequently led to the isolation of a compound unrelated to the jamaicamide and hectochlorin families. Another approach involved stimulation of the biosynthesis of a minor jamaicamide metabolite by cultivation in modified media, and provided insights about the underlying biosynthetic machinery as well as preliminary structure-activity information within this structure class. This study demonstrated that these orthogonal approaches are complementary and enrich secondary metabolomic coverage even in an extensively studied bacterial strain.
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Affiliation(s)
- Paul D. Boudreau
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, United States
| | - Emily A. Monroe
- Department of Biology, William Paterson University, Wayne, New Jersey, 07470, United States of America
| | - Suneet Mehrotra
- Department of Pharmacology, Creighton University School of Medicine, Omaha, Nebraska, 68178, United States of America
| | - Shane Desfor
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, United States
- Department of Biology, California State University San Marcos, San Marcos, California, 92078, United States of America
| | - Anton Korobeynikov
- Algorithmic Biology Laboratory, St. Petersburg Academic University, Russian Academy of Sciences, St. Petersburg, 194021, Russia
- Department of Mathematics and Mechanics, St. Petersburg State University, St. Petersburg, 194021, Russia
- Center for Algorithmic Biotechnology, St. Petersburg State University, St. Petersburg, 194021, Russia
| | - David H. Sherman
- Life Sciences Institute and Department of Medical Chemistry, University of Michigan, Ann Arbor, Michigan, 48109, United States of America
| | - Thomas F. Murray
- Department of Pharmacology, Creighton University School of Medicine, Omaha, Nebraska, 68178, United States of America
| | - Lena Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, United States
| | - Pieter C. Dorrestein
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, 92093, United States of America
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, 92093, United States of America
| | - William H. Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, United States
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, 92093, United States of America
- * E-mail:
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19
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Meng X, Xu Y, Zhao M, Wang F, Ma Y, Jin Y, Liu Y, Song Y, Zhang J. The Functional Property Changes of Muscular Nav1.4 and Cardiac Nav1.5 Induced by Scorpion Toxin BmK AGP-SYPU1 Mutants Y42F and Y5F. Biochemistry 2015; 54:2988-96. [DOI: 10.1021/acs.biochem.5b00067] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Xiangxue Meng
- School of Life Sciences & Biopharmaceutical Science, Shenyang Pharmaceutical University, 103 Wenhua Road, 110016 Shenyang, PR China
- Benxi
Medicine Institute, Shenyang Pharmaceutical University, Shiqiaozi, 177005 Benxi, PR China
| | - Yijia Xu
- School of Life Sciences & Biopharmaceutical Science, Shenyang Pharmaceutical University, 103 Wenhua Road, 110016 Shenyang, PR China
| | - Mingyi Zhao
- School of Life Sciences & Biopharmaceutical Science, Shenyang Pharmaceutical University, 103 Wenhua Road, 110016 Shenyang, PR China
| | - Fangyang Wang
- School of Life Sciences & Biopharmaceutical Science, Shenyang Pharmaceutical University, 103 Wenhua Road, 110016 Shenyang, PR China
| | - Yuanyuan Ma
- School of Life Sciences & Biopharmaceutical Science, Shenyang Pharmaceutical University, 103 Wenhua Road, 110016 Shenyang, PR China
| | - Yao Jin
- School of Life Sciences & Biopharmaceutical Science, Shenyang Pharmaceutical University, 103 Wenhua Road, 110016 Shenyang, PR China
| | - Yanfeng Liu
- School of Life Sciences & Biopharmaceutical Science, Shenyang Pharmaceutical University, 103 Wenhua Road, 110016 Shenyang, PR China
| | - Yongbo Song
- School of Life Sciences & Biopharmaceutical Science, Shenyang Pharmaceutical University, 103 Wenhua Road, 110016 Shenyang, PR China
| | - Jinghai Zhang
- School of Life Sciences & Biopharmaceutical Science, Shenyang Pharmaceutical University, 103 Wenhua Road, 110016 Shenyang, PR China
- School
of Medical Devices, Shenyang Pharmaceutical University, 103 Wenhua
Road, 110016 Shenyang, PR China
- Benxi
Medicine Institute, Shenyang Pharmaceutical University, Shiqiaozi, 177005 Benxi, PR China
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20
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Mehrotra S, Duggan BM, Tello-Aburto R, Newar TD, Gerwick W, Murray TF, Maio WA. Detailed analysis of (-)-palmyrolide a and some synthetic derivatives as voltage-gated sodium channel antagonists. JOURNAL OF NATURAL PRODUCTS 2014; 77:2553-2560. [PMID: 25343669 PMCID: PMC4251536 DOI: 10.1021/np500644k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Indexed: 06/04/2023]
Abstract
A small library of synthetic (-)-palmyrolide A diastereomers, analogues, and acyclic precursors have been examined with respect to their interaction with voltage-gated sodium channels (VGSCs). Toward this goal, the ability of (-)-palmyrolide A and analogues to antagonize veratridine-stimulated Na(+) influx in primary cultures of mouse cerebrocortical neurons was assessed. We found that synthetic (-)-palmyrolide A and its enantiomer functioned as VGSC antagonists to block veratridine-induced sodium influx. A detailed NMR and computational analysis of four diastereomers revealed that none had the same combination of shape and electrostatic potential as exhibited by natural (-)-palmyrolide A. These data indicate that the relative configuration about the tert-butyl and methyl substituents appears to be a prerequisite for biological function. Additional testing revealed that the enamide double bond was not necessary for blocking veratridine-induced sodium influx, whereas the acyclic analogues and other macrolide diastereomers tested were inactive as inhibitors of VGSCs, suggesting that the intact macrolide was required.
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Affiliation(s)
- Suneet Mehrotra
- Department
of Pharmacology, Creighton University School
of Medicine, Omaha, Nebraska 68178, United
States
| | - Brendan M. Duggan
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography
and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92037, United States
| | - Rodolfo Tello-Aburto
- Department
of Chemistry and Biochemistry, New Mexico
State University, Las Cruces, New Mexico 88003, United States
| | - Tara D. Newar
- Department
of Chemistry and Biochemistry, New Mexico
State University, Las Cruces, New Mexico 88003, United States
| | - William
H. Gerwick
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography
and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92037, United States
| | - Thomas F. Murray
- Department
of Pharmacology, Creighton University School
of Medicine, Omaha, Nebraska 68178, United
States
| | - William A. Maio
- Department
of Chemistry and Biochemistry, New Mexico
State University, Las Cruces, New Mexico 88003, United States
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21
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Cao Z, Cui Y, Busse E, Mehrotra S, Rainier JD, Murray TF. Gambierol inhibition of voltage-gated potassium channels augments spontaneous Ca2+ oscillations in cerebrocortical neurons. J Pharmacol Exp Ther 2014; 350:615-23. [PMID: 24957609 DOI: 10.1124/jpet.114.215319] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Gambierol is a marine polycyclic ether toxin produced by the marine dinoflagellate Gambierdiscus toxicus and is a member of the ciguatoxin toxin family. Gambierol has been demonstrated to be either a low-efficacy partial agonist/antagonist of voltage-gated sodium channels or a potent blocker of voltage-gated potassium channels (Kvs). Here we examined the influence of gambierol on intact cerebrocortical neurons. We found that gambierol produced both a concentration-dependent augmentation of spontaneous Ca(2+) oscillations, and an inhibition of Kv channel function with similar potencies. In addition, an array of selective as well as universal Kv channel inhibitors mimicked gambierol in augmenting spontaneous Ca(2+) oscillations in cerebrocortical neurons. These data are consistent with a gambierol blockade of Kv channels underlying the observed increase in spontaneous Ca(2+) oscillation frequency. We also found that gambierol produced a robust stimulation of phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2). Gambierol-stimulated ERK1/2 activation was dependent on both inotropic [N-methyl-d-aspartate (NMDA)] and type I metabotropic glutamate receptors (mGluRs) inasmuch as MK-801 [NMDA receptor inhibitor; (5S,10R)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate], S-(4)-CGP [S-(4)-carboxyphenylglycine], and MTEP [type I mGluR inhibitors; 3-((2-methyl-4-thiazolyl)ethynyl) pyridine] attenuated the response. In addition, 2-aminoethoxydiphenylborane, an inositol 1,4,5-trisphosphate receptor inhibitor, and U73122 (1-[6-[[(17b)-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione), a phospholipase C inhibitor, both suppressed gambierol-induced ERK1/2 activation, further confirming the role of type I mGluR-mediated signaling in the observed ERK1/2 activation. Finally, we found that gambierol produced a concentration-dependent stimulation of neurite outgrowth that was mimicked by 4-aminopyridine, a universal potassium channel inhibitor. Considered together, these data demonstrate that gambierol alters both Ca(2+) signaling and neurite outgrowth in cerebrocortical neurons as a consequence of blockade of Kv channels.
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Affiliation(s)
- Zhengyu Cao
- State Key Laboratory of Natural Medicines, Department of Complex Prescription of Traditional Chinese Medicine, China Pharmaceutical University, Nanjing, People's Republic of China (Z.C.); Department of Pharmacology, School of Medicine, Creighton University, Omaha, Nebraska (Z.C., Y.C., E.B., S.M., T.F.M.); and Department of Chemistry, University of Utah, Salt Lake City, Utah (J.D.R.)
| | - Yanjun Cui
- State Key Laboratory of Natural Medicines, Department of Complex Prescription of Traditional Chinese Medicine, China Pharmaceutical University, Nanjing, People's Republic of China (Z.C.); Department of Pharmacology, School of Medicine, Creighton University, Omaha, Nebraska (Z.C., Y.C., E.B., S.M., T.F.M.); and Department of Chemistry, University of Utah, Salt Lake City, Utah (J.D.R.)
| | - Eric Busse
- State Key Laboratory of Natural Medicines, Department of Complex Prescription of Traditional Chinese Medicine, China Pharmaceutical University, Nanjing, People's Republic of China (Z.C.); Department of Pharmacology, School of Medicine, Creighton University, Omaha, Nebraska (Z.C., Y.C., E.B., S.M., T.F.M.); and Department of Chemistry, University of Utah, Salt Lake City, Utah (J.D.R.)
| | - Suneet Mehrotra
- State Key Laboratory of Natural Medicines, Department of Complex Prescription of Traditional Chinese Medicine, China Pharmaceutical University, Nanjing, People's Republic of China (Z.C.); Department of Pharmacology, School of Medicine, Creighton University, Omaha, Nebraska (Z.C., Y.C., E.B., S.M., T.F.M.); and Department of Chemistry, University of Utah, Salt Lake City, Utah (J.D.R.)
| | - Jon D Rainier
- State Key Laboratory of Natural Medicines, Department of Complex Prescription of Traditional Chinese Medicine, China Pharmaceutical University, Nanjing, People's Republic of China (Z.C.); Department of Pharmacology, School of Medicine, Creighton University, Omaha, Nebraska (Z.C., Y.C., E.B., S.M., T.F.M.); and Department of Chemistry, University of Utah, Salt Lake City, Utah (J.D.R.)
| | - Thomas F Murray
- State Key Laboratory of Natural Medicines, Department of Complex Prescription of Traditional Chinese Medicine, China Pharmaceutical University, Nanjing, People's Republic of China (Z.C.); Department of Pharmacology, School of Medicine, Creighton University, Omaha, Nebraska (Z.C., Y.C., E.B., S.M., T.F.M.); and Department of Chemistry, University of Utah, Salt Lake City, Utah (J.D.R.)
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INOUE M. Chemical construction and structural permutation of neurotoxic natural product, antillatoxin: importance of the three-dimensional structure of the bulky side chain. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2014; 90:56-66. [PMID: 24522155 PMCID: PMC3948940 DOI: 10.2183/pjab.90.56] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 11/29/2013] [Indexed: 06/03/2023]
Abstract
Antillatoxin 1 is a unique natural product that displays potent neurotoxic and neuritogenic activities through activation of voltage-gated sodium channels. The peptidic macrocycle of 1 was attached to a side chain with an exceptionally high degree of methylation. In this review, we discuss the total synthesis and biological evaluation of 1 and its analogues. First we describe an efficient synthetic route to 1. This strategy enabled the unified preparation of nine side chain analogues. Structure-activity relationship studies of these analogues revealed that subtle side chain modification leads to dramatic changes in activity, and detailed structural analyses indicated the importance of the overall size and three dimensional shape of the side chain. Based on these data, we designed and synthesized a photoresponsive analogue, proving that the activity of 1 was modulated via a photochemical reaction. The knowledge accumulated through these studies will be useful for the rational design of new tailor-made molecules to control the function and behavior of ion channels.
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Affiliation(s)
- Masayuki INOUE
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
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Katoh D, Hongo K, Ito K, Yoshino T, Kayama Y, Komukai K, Kawai M, Date T, Yoshimura M. A technique for quantifying intracellular free sodium ion using a microplate reader in combination with sodium-binding benzofuran isophthalate and probenecid in cultured neonatal rat cardiomyocytes. BMC Res Notes 2013; 6:556. [PMID: 24369990 PMCID: PMC3879185 DOI: 10.1186/1756-0500-6-556] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 12/18/2013] [Indexed: 11/16/2022] Open
Abstract
Background Intracellular sodium ([Na+]i) kinetics are involved in cardiac diseases including ischemia, heart failure, and hypertrophy. Because [Na+]i plays a crucial role in modulating the electrical and contractile activity in the heart, quantifying [Na+]i is of great interest. Using fluorescent microscopy with sodium-binding benzofuran isophthalate (SBFI) is the most commonly used method for measuring [Na+]i. However, one limitation associated with this technique is that the test cannot simultaneously evaluate the effects of several types or various concentrations of compounds on [Na+]i. Moreover, there are few reports on the long-term effects of compounds on [Na+]i in cultured cells, although rapid changes in [Na+]i during a period of seconds or several minutes have been widely discussed. Findings We established a novel technique for quantifying [Na+]i in cultured neonatal rat cardiomyocytes attached to a 96-well plate using a microplate reader in combination with SBFI and probenecid. We showed that probenecid is indispensable for the accurate measurement because it prevents dye leakage from the cells. We further confirmed the reliability of this system by quantifying the effects of ouabain, which is known to transiently alter [Na+]i. To illustrate the utility of the new method, we also examined the chronic effects of aldosterone on [Na+]i in cultured cardiomyocytes. Conclusions Our technique can rapidly measure [Na+]i with accuracy and sensitivity comparable to the traditional microscopy based method. The results demonstrated that this 96-well plate based measurement has merits, especially for screening test of compounds regulating [Na+]i, and is useful to elucidate the mechanisms and consequences of altered [Na+]i handling in cardiomyocytes.
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Affiliation(s)
- Daisuke Katoh
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan.
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Zhang F, Xu X, Li T, Liu Z. Shellfish toxins targeting voltage-gated sodium channels. Mar Drugs 2013; 11:4698-723. [PMID: 24287955 PMCID: PMC3877881 DOI: 10.3390/md11124698] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 11/10/2013] [Accepted: 11/12/2013] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs) play a central role in the generation and propagation of action potentials in excitable neurons and other cells and are targeted by commonly used local anesthetics, antiarrhythmics, and anticonvulsants. They are also common targets of neurotoxins including shellfish toxins. Shellfish toxins are a variety of toxic secondary metabolites produced by prokaryotic cyanobacteria and eukaryotic dinoflagellates in both marine and fresh water systems, which can accumulate in marine animals via the food chain. Consumption of shellfish toxin-contaminated seafood may result in potentially fatal human shellfish poisoning. This article provides an overview of the structure, bioactivity, and pharmacology of shellfish toxins that act on VGSCs, along with a brief discussion on their pharmaceutical potential for pain management.
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Affiliation(s)
- Fan Zhang
- Cooperative Innovation Center of Engineering and New Products for Developmental Biology, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China.
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Okura K, Matsuoka S, Inoue M. The bulky side chain of antillatoxin is important for potent toxicity: rational design of photoresponsive cytotoxins based on SAR studies. Chem Commun (Camb) 2013; 49:8024-6. [PMID: 23903352 DOI: 10.1039/c3cc44066d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Antillatoxin is a cyclic peptide with potent neurotoxic and neuritogenic activities. We designed and synthesized six analogues that have photocleavable protecting groups at the terminus of the side chain. Among these compounds, the bis-o-nitrobenzyl acetal derivative was found to exhibit high toxicity and was effectively deactivated by photochemical removal, proving that the biological activity of antillatoxin was modulated by altering the size of the terminal group.
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Affiliation(s)
- Ken Okura
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Okura K, Inoue M. The Orientation of the TerminaltBu Group of Antillatoxin is Important for Potent Toxicity: Design, Synthesis and Biological Evaluation of Conformationally Restricted Analogues of Antillatoxin. ASIAN J ORG CHEM 2013. [DOI: 10.1002/ajoc.201300111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Reith MEA, Ali S, Hashim A, Sheikh IS, Theddu N, Gaddiraju NV, Mehrotra S, Schmitt KC, Murray TF, Sershen H, Unterwald EM, Davis FA. Novel C-1 substituted cocaine analogs unlike cocaine or benztropine. J Pharmacol Exp Ther 2012; 343:413-25. [PMID: 22895898 DOI: 10.1124/jpet.112.193771] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Despite a wealth of information on cocaine-like compounds, there is no information on cocaine analogs with substitutions at C-1. Here, we report on (R)-(-)-cocaine analogs with various C-1 substituents: methyl (2), ethyl (3), n-propyl (4), n-pentyl (5), and phenyl (6). Analog 2 was equipotent to cocaine as an inhibitor of the dopamine transporter (DAT), whereas 3 and 6 were 3- and 10-fold more potent, respectively. None of the analogs, however, stimulated mouse locomotor activity, in contrast to cocaine. Pharmacokinetic assays showed compound 2 occupied mouse brain rapidly, as cocaine itself; moreover, 2 and 6 were behaviorally active in mice in the forced-swim test model of depression and the conditioned place preference test. Analog 2 was a weaker inhibitor of voltage-dependent Na+ channels than cocaine, although 6 was more potent than cocaine, highlighting the need to assay future C-1 analogs for this activity. Receptorome screening indicated few significant binding targets other than the monoamine transporters. Benztropine-like "atypical" DAT inhibitors are known to display reduced cocaine-like locomotor stimulation, presumably by their propensity to interact with an inward-facing transporter conformation. However, 2 and 6, like cocaine, but unlike benztropine, exhibited preferential interaction with an outward-facing conformation upon docking in our DAT homology model. In summary, C-1 cocaine analogs are not cocaine-like in that they are not stimulatory in vivo. However, they are not benztropine-like in binding mechanism and seem to interact with the DAT similarly to cocaine. The present data warrant further consideration of these novel cocaine analogs for antidepressant or cocaine substitution potential.
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Affiliation(s)
- Maarten E A Reith
- Department of Psychiatry, New York University School of Medicine, 450 E 29th Street, Alexandria Building Room 803, New York, NY 10016, USA.
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Inoue M. Total synthesis and functional analysis of non-ribosomal peptides. CHEM REC 2011; 11:284-94. [DOI: 10.1002/tcr.201100014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Indexed: 11/07/2022]
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Cao Z, Shafer TJ, Crofton KM, Gennings C, Murray TF. Additivity of pyrethroid actions on sodium influx in cerebrocortical neurons in primary culture. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:1239-46. [PMID: 21665567 PMCID: PMC3230403 DOI: 10.1289/ehp.1003394] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Accepted: 06/10/2011] [Indexed: 05/06/2023]
Abstract
BACKGROUND Pyrethroid insecticides bind to voltage-gated sodium channels and modify their gating kinetics, thereby disrupting neuronal function. Although previous work has tested the additivity of pyrethroids in vivo, this has not been assessed directly at the primary molecular target using a functional measure. OBJECTIVES We investigated the potency and efficacy of 11 structurally diverse food-use pyrethroids to evoke sodium (Na+) influx in neurons and tested the hypothesis of dose additivity for a mixture of these same 11 compounds. METHODS We determined pyrethroid-induced increases in Na+ influx in primary cultures of cerebrocortical neurons using the Na+-sensitive dye sodium-binding benzofuran isophthalate (SBFI). Concentration-dependent responses for 11 pyrethroids were determined, and the response to dilutions of a mixture of all 11 compounds at an equimolar mixing ratio was assessed. Additivity was tested assuming a dose-additive model. RESULTS Seven pyrethroids produced concentration-dependent, tetrodotoxin-sensitive Na+ influx. The rank order of potency was deltamethrin > S-bioallethrin > β-cyfluthrin > λ-cyhalothrin > esfenvalerate > tefluthrin > fenpropathrin. Cypermethrin and bifenthrin produced modest increases in Na+ influx, whereas permethrin and resmethrin were inactive. When all 11 pyrethroids were present at an equimolar mixing ratio, their actions on Na+ influx were consistent with a dose-additive model. CONCLUSIONS These data provide in vitro relative potency and efficacy measurements for 7 pyrethroid compounds in intact mammalian neurons. Despite differences in individual compound potencies, we found the action of a mixture of all 11 pyrethroids to be additive when we used an appropriate statistical model. These results are consistent with a previous report of the additivity of pyrethroids in vivo.
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Affiliation(s)
- Zhengyu Cao
- Creighton University, School of Medicine, Department of Pharmacology, Omaha, Nebraska 68178, USA
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Hossain MM, Richardson JR. Mechanism of pyrethroid pesticide-induced apoptosis: role of calpain and the ER stress pathway. Toxicol Sci 2011; 122:512-25. [PMID: 21555338 DOI: 10.1093/toxsci/kfr111] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Exposure to the pyrethroid pesticide deltamethrin has been demonstrated to cause apoptosis both in vitro and in vivo. However, the molecular pathways leading to deltamethrin-induced apoptosis have not been established. To identify these pathways, SK-N-AS neuroblastoma cells were exposed to deltamethrin (100 nM-5 μM) for 24-48 h. Deltamethrin produced a time- and dose-dependent increase (21-300%) in DNA fragmentation, an indicator of apoptosis. Data demonstrate that the initiation of DNA fragmentation resulted from interaction of deltamethrin with Na⁺ channels and consequent calcium influx, as tetrodotoxin and the intracellular Ca²⁺ chelator BAPTA-AM completely prevented apoptosis. DNA fragmentation was accompanied by increased caspase-9 and -3 activities and was abolished by specific caspase-9 and -3 inhibitors. However, deltamethrin did not increase cytosolic cytochrome c levels, indicating that the mitochondrial pathway was likely not involved. Additional studies demonstrated that deltamethrin exposure activated caspase-12 activity and that pharmacological inhibition and siRNA knockdown of calpain prevented deltamethrin-induced DNA fragmentation, thus indicating a role for the endoplasmic reticulum (ER) stress pathway. This was confirmed by the observation that inhibition of eIF2α abolished deltamethrin-induced DNA fragmentation. Together, these data demonstrate that deltamethrin causes apoptosis through its interaction with Na⁺ channels, leading to calcium overload and activation of the ER stress pathway. Because ER stress and the subsequent unfolded protein response have been observed in a number of neurodegenerative diseases, these data provide mechanistic information by which high-level exposure to pyrethroids may contribute to neurodegeneration.
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Affiliation(s)
- Muhammad M Hossain
- Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
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Cagide E, Louzao MC, Espiña B, Ares IR, Vieytes MR, Sasaki M, Fuwa H, Tsukano C, Konno Y, Yotsu-Yamashita M, Paquette LA, Yasumoto T, Botana LM. Comparative cytotoxicity of gambierol versus other marine neurotoxins. Chem Res Toxicol 2011; 24:835-42. [PMID: 21517028 DOI: 10.1021/tx200038j] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many microalgae produce compounds that exhibit potent biological activities. Ingestion of marine organisms contaminated with those toxins results in seafood poisonings. In many cases, the lack of toxic material turns out to be an obstacle to make the toxicological investigations needed. In this study, we evaluate the cytotoxicity of several marine toxins on neuroblastoma cells, focusing on gambierol and its effect on cytosolic calcium levels. In addition, we compared the effects of this toxin with ciguatoxin, brevetoxin, and gymnocin-A, with which gambierol shares a similar ladder-like backbone, as well as with polycavernoside A analogue 5, a glycosidic macrolide toxin. For this purpose, different fluorescent dyes were used: Fura-2 to monitor variations in cytosolic calcium levels, Alamar Blue to detect cytotoxicity, and Oregon Green 514 Phalloidin to quantify and visualize modifications in the actin cytoskeleton. Data showed that, while gambierol and ciguatoxin were successful in producing a calcium influx in neuroblastoma cells, gymnocin-A was unable to modify this parameter. Nevertheless, none of the toxins induced morphological changes or alterations in the actin assembly. Although polycavernoside A analogue 5 evoked a sharp reduction of the cellular metabolism of neuroblastoma cells, gambierol scarcely reduced it, and ciguatoxin, brevetoxin, and gymnocin-A failed to produce any signs of cytotoxicity. According to this, sharing a similar polycyclic ether backbone is not enough to produce the same effects on neuroblastoma cells; therefore, more studies should be carried out with these toxins, whose effects may be being underestimated.
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Affiliation(s)
- E Cagide
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo, Spain
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Abstract
This Article describes the total synthesis of the marine ladder toxin brevenal utilizing a convergent synthetic strategy. Critical to the success of this work was the use of olefinic-ester cyclization reactions and the utilization of glycal epoxides as precursors to C-C and C-H bonds.
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Affiliation(s)
- Yuan Zhang
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA
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Fuwa H. Total Synthesis of Structurally Complex Marine Oxacyclic Natural Products. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2010. [DOI: 10.1246/bcsj.20100209] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Antillatoxin is a sodium channel activator that displays unique efficacy in heterologously expressed rNav1.2, rNav1.4 and rNav1.5 α subunits. BMC Neurosci 2010; 11:154. [PMID: 21156065 PMCID: PMC3009643 DOI: 10.1186/1471-2202-11-154] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 12/14/2010] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Antillatoxin (ATX) is a structurally unique lipopeptide produced by the marine cyanobacterium Lyngbya majuscula. ATX activates voltage-gated sodium channel α-subunits at an undefined recognition site and stimulates sodium influx in neurons. However, the pharmacological properties and selectivity of ATX on the sodium channel α-subunits were not fully characterized. RESULTS In this study, we characterized the pharmacological properties and selectivity of ATX in cells heterologously expressing rNa(v)1.2, rNa(v)1.4 or rNa(v)1.5 α-subunits by using the Na(+) selective fluorescent dye, sodium-binding benzofuran isophthalate. ATX produced sodium influx in cells expressing each sodium channel α-subunit, whereas two other sodium channel activators, veratridine and brevetoxin-2, were without effect. The ATX potency at rNa(v)1.2, rNa(v)1.4 and rNa(v)1.5 did not differ significantly. Similarly, there were no significant differences in the efficacy for ATX-induced sodium influx between rNa(v)1.2, rNa(v)1.4 and rNa(v)1.5 α-subunits. ATX also produced robust Ca²(+) influx relative to other sodium channel activators in the calcium-permeable DEAA mutant of rNa(v)1.4 α-subunit. Finally, we demonstrated that the 8-demethyl-8,9-dihydro-antillatoxin analog was less efficacious and less potent in stimulating sodium influx. CONCLUSIONS ATX displayed a unique efficacy with respect to stimulation of sodium influx in cells expressing rNa(v)1.2, rNa(v)1.4 and rNa(v)1.5 α-subunits. The efficacy of ATX was distinctive inasmuch as it was not shared by activators of neurotoxin sites 2 and 5 on VGSC α-subunits. Given the unique pharmacological properties of ATX interaction with sodium channel α-subunits, decoding the molecular determinants and mechanism of action of antillatoxin may provide further insight into sodium channel gating mechanisms.
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Neurotoxic cyanobacterial toxins. Toxicon 2010; 56:813-28. [DOI: 10.1016/j.toxicon.2009.07.036] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 07/27/2009] [Accepted: 07/30/2009] [Indexed: 11/19/2022]
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Okura K, Matsuoka S, Goto R, Inoue M. The Twisted Side Chain of Antillatoxin is Important for Potent Toxicity: Total Synthesis and Biological Evaluation of Antillatoxin and Analogues. Angew Chem Int Ed Engl 2010; 49:329-32. [DOI: 10.1002/anie.200905892] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ken Okura
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo‐ku, Tokyo 113‐0033 (Japan), Fax: (+81) 3‐3395‐5214
| | - Shigeru Matsuoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo‐ku, Tokyo 113‐0033 (Japan), Fax: (+81) 3‐3395‐5214
| | - Ryosuke Goto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo‐ku, Tokyo 113‐0033 (Japan), Fax: (+81) 3‐3395‐5214
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo‐ku, Tokyo 113‐0033 (Japan), Fax: (+81) 3‐3395‐5214
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Okura K, Matsuoka S, Goto R, Inoue M. The Twisted Side Chain of Antillatoxin is Important for Potent Toxicity: Total Synthesis and Biological Evaluation of Antillatoxin and Analogues. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200905892] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ken Okura
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo‐ku, Tokyo 113‐0033 (Japan), Fax: (+81) 3‐3395‐5214
| | - Shigeru Matsuoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo‐ku, Tokyo 113‐0033 (Japan), Fax: (+81) 3‐3395‐5214
| | - Ryosuke Goto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo‐ku, Tokyo 113‐0033 (Japan), Fax: (+81) 3‐3395‐5214
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo‐ku, Tokyo 113‐0033 (Japan), Fax: (+81) 3‐3395‐5214
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Pereira A, Cao Z, Murray TF, Gerwick WH. Hoiamide a, a sodium channel activator of unusual architecture from a consortium of two papua new Guinea cyanobacteria. ACTA ACUST UNITED AC 2009; 16:893-906. [PMID: 19716479 DOI: 10.1016/j.chembiol.2009.06.012] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 06/23/2009] [Accepted: 06/26/2009] [Indexed: 11/30/2022]
Abstract
Hoiamide A, a novel bioactive cyclic depsipeptide, was isolated from an environmental assemblage of the marine cyanobacteria Lyngbya majuscula and Phormidium gracile collected in Papua New Guinea. This stereochemically complex metabolite possesses a highly unusual structure, which likely derives from a mixed peptide-polyketide biogenetic origin, and includes a peptidic section featuring an acetate extended and S-adenosyl methionine modified isoleucine moiety, a triheterocyclic fragment bearing two alpha-methylated thiazolines and one thiazole, and a highly oxygenated and methylated C15-polyketide substructure. Pure hoiamide A potently inhibited [(3)H]batrachotoxin binding to voltage-gated sodium channels (IC(50) = 92.8 nM), activated sodium influx (EC(50) = 2.31 microM) in mouse neocortical neurons, and exhibited modest cytotoxicity to cancer cells. Further investigation revealed that hoiamide A is a partial agonist of site 2 on the voltage-gated sodium channel.
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Affiliation(s)
- Alban Pereira
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, 92093, USA
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Jabba SV, Prakash A, Dravid SM, Gerwick WH, Murray TF. Antillatoxin, a novel lipopeptide, enhances neurite outgrowth in immature cerebrocortical neurons through activation of voltage-gated sodium channels. J Pharmacol Exp Ther 2009; 332:698-709. [PMID: 20026674 DOI: 10.1124/jpet.109.161802] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Antillatoxin (ATX) is a structurally novel lipopeptide that activates voltage-gated sodium channels (VGSC) leading to sodium influx in cerebellar granule neurons and cerebrocortical neurons 8 to 9 days in vitro (Li et al., 2001; Cao et al., 2008). However, the precise recognition site for ATX on the VGSC remains to be defined. Inasmuch as elevation of intracellular sodium ([Na(+)](i)) may increase N-methyl-d-aspartate receptor (NMDAR)-mediated Ca(2+) influx, Na(+) may function as a signaling molecule. We hypothesized that ATX may enhance neurite outgrowth in cerebrocortical neurons by elevating [Na(+)](i) and augmenting NMDAR function. ATX (30-100 nM) robustly stimulated neurite outgrowth, and this enhancement was sensitive to the VGSC antagonist, tetrodotoxin. To unambiguously demonstrate the enhancement of NMDA receptor function by ATX, we recorded single-channel currents from cell-attached patches. ATX was found to increase the open probability of NMDA receptors. Na(+)-dependent up-regulation of NMDAR function has been shown to be regulated by Src family kinase (SFK) (Yu and Salter, 1998). The Src kinase inhibitor PP2 abrogated ATX-enhanced neurite outgrowth, suggesting a SFK involvement in this response. ATX-enhanced neurite outgrowth was also inhibited by the NMDAR antagonist, (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine hydrogen maleate (MK-801), and the calmodulin-dependent kinase kinase (CaMKK) inhibitor, 1,8-naphthoylene benzimidazole-3-carboxylic acid (STO-609), demonstrating the requirement for NMDAR activation with subsequent downstream engagement of the Ca(2+)-dependent CaMKK pathway. These results with the structurally and mechanistically novel natural product, ATX, confirm and generalize our earlier results with a neurotoxin site 5 ligand. These data suggest that VGSC activators may represent a novel pharmacological strategy to regulate neuronal plasticity through NMDAR-dependent mechanisms.
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Affiliation(s)
- S V Jabba
- Creighton University School of Medicine, Department of Pharmacology, Omaha, NE 68178, USA
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Errera RM, Bourdelais A, Drennan MA, Dodd EB, Henrichs DW, Campbell L. Variation in brevetoxin and brevenal content among clonal cultures of Karenia brevis may influence bloom toxicity. Toxicon 2009; 55:195-203. [PMID: 19631681 DOI: 10.1016/j.toxicon.2009.07.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 07/14/2009] [Accepted: 07/16/2009] [Indexed: 10/20/2022]
Abstract
Karenia brevis, the major harmful algal (HA) species in the Gulf of Mexico, produces a suite of brevetoxins and brevenal, a nontoxic brevetoxin antagonist. K. brevis growth is reported to be optimum at oceanic conditions, yet blooms are most problematic in coastal waters. Differences in growth rate, total brevetoxin production, brevetoxin profiles and brevenal production were evaluated among eight K. brevis clones grown at salinities of 35 and 27, but otherwise identical conditions. All measured parameters varied significantly among clones and the individual responses to decreased salinity varied as well. At 27, growth rates of four clones increased (Wilson, TXB3, SP1 and SP2), but decreased in three others (TXB4, SP3 and NBK) as compared to 35. Total brevetoxin cellular concentration varied up to approximately ten-fold among clones. For most clones (5 of 8), no significant difference in total toxin production between salinity treatments was observed; however, there was a shift in brevetoxin profiles to a higher proportion of PbTx-1 vs. PbTx-2 (in 7 of 8 clones). Brevenal production decreased in the majority of the clones (6 of 8) when grown at a salinity of 27. Results suggest that K. brevis produces more PbTx-1 and less brevenal in lower salinity waters.
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Affiliation(s)
- Reagan M Errera
- Department of Oceanography, 3146 TAMU, Texas A&M University, College Station, TX 77843, USA
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Sodium channel activation augments NMDA receptor function and promotes neurite outgrowth in immature cerebrocortical neurons. J Neurosci 2009; 29:3288-301. [PMID: 19279266 DOI: 10.1523/jneurosci.6104-08.2009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
A range of extrinsic signals, including afferent activity, affect neuronal growth and plasticity. Neuronal activity regulates intracellular Ca(2+), and activity-dependent calcium signaling has been shown to regulate dendritic growth and branching (Konur and Ghosh, 2005). NMDA receptor (NMDAR) stimulation of Ca(2+)/calmodulin-dependent protein kinase signaling cascades has, moreover, been demonstrated to regulate neurite/axonal outgrowth (Wayman et al., 2004). We used a sodium channel activator, brevetoxin (PbTx-2), to explore the relationship between intracellular [Na(+)] and NMDAR-dependent development. PbTx-2 alone, at a concentration of 30 nM, did not affect Ca(2+) dynamics in 2 d in vitro cerebrocortical neurons; however, this treatment robustly potentiated NMDA-induced Ca(2+) influx. The 30 nM PbTx-2 treatment produced a maximum [Na(+)](i) of 16.9 +/- 1.5 mM, representing an increment of 8.8 +/- 1.8 mM over basal. The corresponding membrane potential change produced by 30 nM PbTx-2 was modest and, therefore, insufficient to relieve the voltage-dependent Mg(2+) block of NMDARs. To unambiguously demonstrate the enhancement of NMDA receptor function by PbTx-2, we recorded single-channel currents from cell-attached patches. PbTx-2 treatment was found to increase both the mean open time and open probability of NMDA receptors. These effects of PbTx-2 on NMDA receptor function were dependent on extracellular Na(+) and activation of Src kinase. The functional consequences of PbTx-2-induced enhancement of NMDAR function were evaluated in immature cerebrocortical neurons. PbTx-2 concentrations between 3 and 300 nM enhanced neurite outgrowth. Voltage-gated sodium channel activators may accordingly represent a novel pharmacologic strategy to regulate neuronal plasticity through an NMDA receptor and Src family kinase-dependent mechanism.
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Osei Akoto C, Rainier J. Harnessing Glycal-Epoxide Rearrangements: The Generation of the AB, EF, and IJ Rings of Adriatoxin. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200803791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Akoto CO, Rainier JD. Harnessing glycal-epoxide rearrangements: the generation of the AB, EF, and IJ rings of adriatoxin. Angew Chem Int Ed Engl 2008; 47:8055-8. [PMID: 18785198 PMCID: PMC2597071 DOI: 10.1002/anie.200803791] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Clement Osei Akoto
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, UT 84112, USA
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