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Palmisano VF, Anguita-Ortiz N, Faraji S, Nogueira JJ. Voltage-Gated Ion Channels: Structure, Pharmacology and Photopharmacology. Chemphyschem 2024; 25:e202400162. [PMID: 38649320 DOI: 10.1002/cphc.202400162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 04/21/2024] [Accepted: 04/22/2024] [Indexed: 04/25/2024]
Abstract
Voltage-gated ion channels are transmembrane proteins responsible for the generation and propagation of action potentials in excitable cells. Over the last decade, advancements have enabled the elucidation of crystal structures of ion channels. This progress in structural understanding, particularly in identifying the binding sites of local anesthetics, opens avenues for the design of novel compounds capable of modulating ion conduction. However, many traditional drugs lack selectivity and come with adverse side effects. The emergence of photopharmacology has provided an orthogonal way of controlling the activity of compounds, enabling the regulation of ion conduction with light. In this review, we explore the central pore region of voltage-gated sodium and potassium channels, providing insights from both structural and pharmacological perspectives. We discuss the different binding modes of synthetic compounds that can physically occlude the pore and, therefore, block ion conduction. Moreover, we examine recent advances in the photopharmacology of voltage-gated ion channels, introducing molecular approaches aimed at controlling their activity by using photosensitive drugs.
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Affiliation(s)
- Vito F Palmisano
- Department of Chemistry, Universidad Autónoma de Madrid, 28049, Madrid, Spain
- Theoretical Chemistry Group, Zernike Institute for Advanced Materials, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Nuria Anguita-Ortiz
- Department of Chemistry, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Shirin Faraji
- Theoretical Chemistry Group, Zernike Institute for Advanced Materials, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Juan J Nogueira
- Department of Chemistry, Universidad Autónoma de Madrid, 28049, Madrid, Spain
- IADCHEM, Institute for Advanced Research in Chemistry, Universidad Autónoma de Madrid, 28049, Madrid, Spain
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2
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Chida K, Kanazawa H, Kinoshita H, Roy AM, Hakamada K, Takabe K. The role of lidocaine in cancer progression and patient survival. Pharmacol Ther 2024; 259:108654. [PMID: 38701900 PMCID: PMC11162934 DOI: 10.1016/j.pharmthera.2024.108654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/17/2024] [Accepted: 04/30/2024] [Indexed: 05/05/2024]
Abstract
Since its development in 1943, lidocaine has been one of the most commonly used local anesthesia agents for surgical procedures. Lidocaine alters neuronal signal transmission by prolonging the inactivation of fast voltage-gated sodium channels in the cell membrane of neurons, which are responsible for action potential propagation. Recently, it has attracted attention due to emerging evidence suggesting its potential antitumor properties, particularly in the in vitro setting. Further, local administration of lidocaine around the tumor immediately prior to surgical removal has been shown to improve overall survival in breast cancer patients. However, the exact mechanisms driving these antitumor effects remain largely unclear. In this article, we will review the existing literature on the mechanism of lidocaine as a local anesthetic, its effects on the cancer cells and the tumor microenvironment, involved pathways, and cancer progression. Additionally, we will explore recent reports highlighting its impact on clinical outcomes in cancer patients. Taken together, there remains significant ambiguity surrounding lidocaine's functions and roles in cancer biology, particularly in perioperative setting.
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Affiliation(s)
- Kohei Chida
- Department of Surgical Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; Department of Gastroenterological Surgery, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan.
| | - Hirofumi Kanazawa
- The University of Texas Health Science Center at Tyler School of Medicine, TX, USA.
| | - Hirotaka Kinoshita
- Department of Anesthesiology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
| | - Arya Mariam Roy
- Department of Hematology and Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA.
| | - Kenichi Hakamada
- Department of Gastroenterological Surgery, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan.
| | - Kazuaki Takabe
- Department of Surgical Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan; Department of Surgery, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, The State University of New York, Buffalo, NY 14263, USA; Department of Breast Surgery and Oncology, Tokyo Medical University, Tokyo 160-8402, Japan; Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan; Department of Breast Surgery, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan; Department of Breast Surgery, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA.
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3
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Liu Y, Bassetto CAZ, Pinto BI, Bezanilla F. A mechanistic reinterpretation of fast inactivation in voltage-gated Na + channels. Nat Commun 2023; 14:5072. [PMID: 37604801 PMCID: PMC10442390 DOI: 10.1038/s41467-023-40514-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 07/25/2023] [Indexed: 08/23/2023] Open
Abstract
The hinged-lid model was long accepted as the canonical model for fast inactivation in Nav channels. It predicts that the hydrophobic IFM motif acts intracellularly as the gating particle that binds and occludes the pore during fast inactivation. However, the observation in recent high-resolution structures that the bound IFM motif is located far from the pore, contradicts this preconception. Here, we provide a mechanistic reinterpretation of fast inactivation based on structural analysis and ionic/gating current measurements. We demonstrate that in Nav1.4 the final inactivation gate is comprised of two hydrophobic rings at the bottom of S6 helices. These rings function in series and close downstream of IFM binding. Reducing the volume of the sidechain in both rings leads to a partially conductive, leaky inactivated state and decreases the selectivity for Na+ ion. Altogether, we present an alternative molecular framework to describe fast inactivation.
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Affiliation(s)
- Yichen Liu
- Department of Neurobiology, University of Chicago, Chicago, IL, USA
| | - Carlos A Z Bassetto
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Bernardo I Pinto
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Francisco Bezanilla
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA.
- Centro Interdisciplinario de Neurociencias de Valparaíso, Valparaíso, Chile.
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4
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Huang J, Fan X, Jin X, Jo S, Zhang HB, Fujita A, Bean BP, Yan N. Cannabidiol inhibits Na v channels through two distinct binding sites. Nat Commun 2023; 14:3613. [PMID: 37330538 PMCID: PMC10276812 DOI: 10.1038/s41467-023-39307-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 06/07/2023] [Indexed: 06/19/2023] Open
Abstract
Cannabidiol (CBD), a major non-psychoactive phytocannabinoid in cannabis, is an effective treatment for some forms of epilepsy and pain. At high concentrations, CBD interacts with a huge variety of proteins, but which targets are most relevant for clinical actions is still unclear. Here we show that CBD interacts with Nav1.7 channels at sub-micromolar concentrations in a state-dependent manner. Electrophysiological experiments show that CBD binds to the inactivated state of Nav1.7 channels with a dissociation constant of about 50 nM. The cryo-EM structure of CBD bound to Nav1.7 channels reveals two distinct binding sites. One is in the IV-I fenestration near the upper pore. The other binding site is directly next to the inactivated "wedged" position of the Ile/Phe/Met (IFM) motif on the short linker between repeats III and IV, which mediates fast inactivation. Consistent with producing a direct stabilization of the inactivated state, mutating residues in this binding site greatly reduced state-dependent binding of CBD. The identification of this binding site may enable design of compounds with improved properties compared to CBD itself.
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Affiliation(s)
- Jian Huang
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Xiao Fan
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Xueqin Jin
- Beijing Frontier Research Center for Biological Structures, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Sooyeon Jo
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA, 02115, USA
| | - Hanxiong Bear Zhang
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA, 02115, USA
| | - Akie Fujita
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA, 02115, USA
| | - Bruce P Bean
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA, 02115, USA.
| | - Nieng Yan
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
- Beijing Frontier Research Center for Biological Structures, State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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5
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Wu Q, Huang J, Fan X, Wang K, Jin X, Huang G, Li J, Pan X, Yan N. Structural mapping of Na v1.7 antagonists. Nat Commun 2023; 14:3224. [PMID: 37270609 DOI: 10.1038/s41467-023-38942-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 05/22/2023] [Indexed: 06/05/2023] Open
Abstract
Voltage-gated sodium (Nav) channels are targeted by a number of widely used and investigational drugs for the treatment of epilepsy, arrhythmia, pain, and other disorders. Despite recent advances in structural elucidation of Nav channels, the binding mode of most Nav-targeting drugs remains unknown. Here we report high-resolution cryo-EM structures of human Nav1.7 treated with drugs and lead compounds with representative chemical backbones at resolutions of 2.6-3.2 Å. A binding site beneath the intracellular gate (site BIG) accommodates carbamazepine, bupivacaine, and lacosamide. Unexpectedly, a second molecule of lacosamide plugs into the selectivity filter from the central cavity. Fenestrations are popular sites for various state-dependent drugs. We show that vinpocetine, a synthetic derivative of a vinca alkaloid, and hardwickiic acid, a natural product with antinociceptive effect, bind to the III-IV fenestration, while vixotrigine, an analgesic candidate, penetrates the IV-I fenestration of the pore domain. Our results permit building a 3D structural map for known drug-binding sites on Nav channels summarized from the present and previous structures.
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Affiliation(s)
- Qiurong Wu
- Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jian Huang
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
| | - Xiao Fan
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
| | - Kan Wang
- Department of Anesthesiology, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Xueqin Jin
- Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Gaoxingyu Huang
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
- Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, Zhejiang Province, China
| | - Jiaao Li
- Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xiaojing Pan
- Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
| | - Nieng Yan
- Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
- Shenzhen Medical Academy of Research and Translation, Guangming District, Shenzhen, 518107, Guangdong Province, China.
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Liu Y, Bassetto CAZ, Pinto BI, Bezanilla F. A Mechanistic Reinterpretation of Fast Inactivation in Voltage-Gated Na + Channels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.27.538555. [PMID: 37162849 PMCID: PMC10168311 DOI: 10.1101/2023.04.27.538555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Fast Inactivation in voltage-gated Na + channels plays essential roles in numerous physiological functions. The canonical hinged-lid model has long predicted that a hydrophobic motif in the DIII-DIV linker (IFM) acts as the gating particle that occludes the permeation pathway during fast inactivation. However, the fact that the IFM motif is located far from the pore in recent high-resolution structures of Nav + channels contradicts this status quo model. The precise molecular determinants of fast inactivation gate once again, become an open question. Here, we provide a mechanistic reinterpretation of fast inactivation based on ionic and gating current data. In Nav1.4 the actual inactivation gate is comprised of two hydrophobic rings at the bottom of S6. These function in series and closing once the IFM motif binds. Reducing the volume of the sidechain in both rings led to a partially conductive inactivated state. Our experiments also point to a previously overlooked coupling pathway between the bottom of S6 and the selectivity filter.
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Affiliation(s)
- Yichen Liu
- Department of Neurobiology, University of Chicago, Chicago, IL, USA
| | - Carlos A Z Bassetto
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Bernardo I Pinto
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Francisco Bezanilla
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
- Centro Interdisciplinario de Neurociencias de Valparaiso, Valparaiso, Chile
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7
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Negami T, Terada T. Calculations of the binding free energies of the Comprehensive in vitro Proarrhythmia Assay (CiPA) reference drugs to cardiac ion channels. Biophys Physicobiol 2023; 20:e200016. [PMID: 38496247 PMCID: PMC10941965 DOI: 10.2142/biophysico.bppb-v20.0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 03/24/2023] [Indexed: 03/19/2024] Open
Abstract
The evaluation of the inhibitory activities of drugs on multiple cardiac ion channels is required for the accurate assessment of proarrhythmic risks. Moreover, the in silico prediction of such inhibitory activities of drugs on cardiac channels can improve the efficiency of the drug-development process. Here, we performed molecular docking simulations to predict the complex structures of 25 reference drugs that were proposed by the Comprehensive in vitro Proarrhythmia Assay consortium using two cardiac ion channels, the human ether-a-go-go-related gene (hERG) potassium channel and human NaV1.5 (hNaV1.5) sodium channel, with experimentally available structures. The absolute binding free energy (ΔGbind) values of the predicted structures were calculated by a molecular dynamics-based method and compared with the experimental half-maximal inhibitory concentration (IC50) data. Furthermore, the regression analysis between the calculated values and negative of the common logarithm of the experimental IC50 values (pIC50) revealed that the calculated values of four and ten drugs deviated significantly from the regression lines of the hERG and hNaV1.5 channels, respectively. We reconsidered the docking poses and protonation states of the drugs based on the experimental data and recalculated their ΔGbind values. Finally, the calculated ΔGbind values of 24 and 19 drugs correlated with their experimental pIC50 values (coefficients of determination=0.791 and 0.613 for the hERG and hNaV1.5 channels, respectively). Thus, the regression analysis between the calculated ΔGbind and experimental IC50 data ensured the realization of an increased number of reliable complex structures.
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Affiliation(s)
- Tatsuki Negami
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tohru Terada
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
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8
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Kimball IH, Nguyen PT, Olivera BM, Sack JT, Yarov-Yarovoy V. Molecular determinants of μ-conotoxin KIIIA interaction with the human voltage-gated sodium channel Na V1.7. Front Pharmacol 2023; 14:1156855. [PMID: 37007002 PMCID: PMC10060530 DOI: 10.3389/fphar.2023.1156855] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 03/03/2023] [Indexed: 03/18/2023] Open
Abstract
The voltage-gated sodium (NaV) channel subtype NaV1.7 plays a critical role in pain signaling, making it an important drug target. Here we studied the molecular interactions between μ-Conotoxin KIIIA (KIIIA) and the human NaV1.7 channel (hNaV1.7). We developed a structural model of hNaV1.7 using Rosetta computational modeling and performed in silico docking of KIIIA using RosettaDock to predict residues forming specific pairwise contacts between KIIIA and hNaV1.7. We experimentally validated these contacts using mutant cycle analysis. Comparison between our KIIIA-hNaV1.7 model and the cryo-EM structure of KIIIA-hNaV1.2 revealed key similarities and differences between NaV channel subtypes with potential implications for the molecular mechanism of toxin block. The accuracy of our integrative approach, combining structural data with computational modeling, experimental validation, and molecular dynamics simulations, suggests that Rosetta structural predictions will be useful for rational design of novel biologics targeting specific NaV channels.
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Affiliation(s)
- Ian H. Kimball
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Phuong T. Nguyen
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | | | - Jon T. Sack
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA, United States
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA, United States
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9
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Sigler W, Oliveira A. Molecular basis of the different effects of procainamide and N-acetylprocainamide on the maximum upstroke velocity and half-decay time of the cardiac action potential in guinea pig papillary muscle. Braz J Med Biol Res 2023; 56:e12073. [PMID: 36722655 PMCID: PMC9883003 DOI: 10.1590/1414-431x2023e12073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 11/14/2022] [Indexed: 01/31/2023] Open
Abstract
Procainamide (PA) and its in vivo metabolite, N-acetylprocainamide (NAPA), display some pharmacological differences. Although it is agreed that PA is a class IA antiarrhythmic, it has been reported that NAPA is a pure class III antiarrhythmic that affects only the repolarizing phase of the cardiac action potential. This last concept, observed exclusively in dogs, gained wide acceptance, appearing in classic pharmacology textbooks. However, evidence in species such as mice and rats indicates that NAPA can affect cardiac Na+ channels, which is unexpected for a pure class III antiarrhythmic drug. To further clarify this issue, the effects of PA (used as a reference drug) and NAPA on the maximum upstroke velocity (Vmax) and half-decay time (HDT) of the cardiac action potential were examined in the isolated right papillaris magnus of the guinea pig heart. Both PA and NAPA affected Vmax at lower concentrations than required to affect HDT, and NAPA had weaker effects on both variables. Thus, NAPA displayed typical class IA antiarrhythmic behavior. Therefore, the concept that NAPA is a pure class III antiarrhythmic drug is more species-dependent than previously envisioned. In addition, we demonstrated that the differential pharmacology of PA and NAPA is explainable, in molecular terms, by steric hindrance of the effects of NAPA and the greater number of potent aromatic-aromatic and cation π interactions with Na+ or K+ cardiac channels for PA.
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Affiliation(s)
- W. Sigler
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil
- Faculdade de Ciências Farmacêuticas e Bioquímicas, Faculdades Oswaldo Cruz, São Paulo, SP, Brasil
| | - A.C. Oliveira
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil
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10
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De Bellis M, Boccanegra B, Cerchiara AG, Imbrici P, De Luca A. Blockers of Skeletal Muscle Na v1.4 Channels: From Therapy of Myotonic Syndrome to Molecular Determinants of Pharmacological Action and Back. Int J Mol Sci 2023; 24:ijms24010857. [PMID: 36614292 PMCID: PMC9821513 DOI: 10.3390/ijms24010857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/28/2022] [Accepted: 12/30/2022] [Indexed: 01/05/2023] Open
Abstract
The voltage-gated sodium channels represent an important target for drug discovery since a large number of physiological processes are regulated by these channels. In several excitability disorders, including epilepsy, cardiac arrhythmias, chronic pain, and non-dystrophic myotonia, blockers of voltage-gated sodium channels are clinically used. Myotonia is a skeletal muscle condition characterized by the over-excitability of the sarcolemma, resulting in delayed relaxation after contraction and muscle stiffness. The therapeutic management of this disorder relies on mexiletine and other sodium channel blockers, which are not selective for the Nav1.4 skeletal muscle sodium channel isoform. Hence, the importance of deepening the knowledge of molecular requirements for developing more potent and use-dependent drugs acting on Nav1.4. Here, we review the available treatment options for non-dystrophic myotonia and the structure-activity relationship studies performed in our laboratory with a focus on new compounds with potential antimyotonic activity.
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11
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Zhorov BS. Molecular Modeling of Cardiac Sodium Channel with Mexiletine. MEMBRANES 2022; 12:membranes12121252. [PMID: 36557159 PMCID: PMC9786191 DOI: 10.3390/membranes12121252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/04/2022] [Accepted: 12/06/2022] [Indexed: 05/15/2023]
Abstract
A sodium channel blocker mexiletine (MEX) is used to treat chronic pain, myotonia and some arrhythmias. Mutations in the pore domain (PD) of voltage-gated sodium channels differently affect tonic block (TB) and use-dependent block (UDB) by MEX. Previous studies identified several MEX-sensing residues in the hNav1.5 channel and demonstrated that the channel block by MEX increases with activation of the voltage-sensing domain III (VSDIII), whereas MEX stabilizes the activated state of VSDIII. Structural rationales for these observations are unclear. Here, Monte Carlo (MC) energy minimizations were used to dock MEX and its more potent analog, Thio-Me2, into the hNav1.5 cryo-EM structure with activated VSDs and presumably inactivated PD. Computations yielded two ensembles of ligand binding poses in close contacts with known MEX-sensing residues in helices S6III, S6IV and P1IV. In both ensembles, the ligand NH3 group approached the cation-attractive site between backbone carbonyls at the outer-pore bottom, while the aromatic ring protruded ether into the inner pore (putative UDB pose) or into the III/IV fenestration (putative TB pose). In silico deactivation of VSDIII shifted helices S4-S5III, S5III, S6III and S6IV and tightened the TB site. In a model with activated VSDIII and three resting VSDs, MC-minimized energy profile of MEX pulled from the TB site towards lipids shows a deep local minimum due to interactions with 11 residues in S5III, P1III, S6III and S6IV. The minimum may correspond to an interim binding site for MEX in the hydrophobic path to the TB site along the lipid-exposed sides of repeats III and IV where 15 polar and aromatic residues would attract cationic blockers. The study explains numerous experimental data and suggests the mechanism of allosteric modification of the MEX binding site by VSDIII.
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Affiliation(s)
- Boris S. Zhorov
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada;
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St. Petersburg, Russia
- Almazov National Medical Research Centre, 197341 St. Petersburg, Russia
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12
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Körner J, Albani S, Sudha Bhagavath Eswaran V, Roehl AB, Rossetti G, Lampert A. Sodium Channels and Local Anesthetics-Old Friends With New Perspectives. Front Pharmacol 2022; 13:837088. [PMID: 35418860 PMCID: PMC8996304 DOI: 10.3389/fphar.2022.837088] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/16/2022] [Indexed: 12/11/2022] Open
Abstract
The long history of local anesthetics (LAs) starts out in the late 19th century when the content of coca plant leaves was discovered to alleviate pain. Soon after, cocaine was established and headed off to an infamous career as a substance causing addiction. Today, LAs and related substances-in modified form-are indispensable in our clinical everyday life for pain relief during and after minor and major surgery, and dental practices. In this review, we elucidate on the interaction of modern LAs with their main target, the voltage-gated sodium channel (Navs), in the light of the recently published channel structures. Knowledge of the 3D interaction sites of the drug with the protein will allow to mechanistically substantiate the comprehensive data available on LA gating modification. In the 1970s it was suggested that LAs can enter the channel pore from the lipid phase, which was quite prospective at that time. Today we know from cryo-electron microscopy structures and mutagenesis experiments, that indeed Navs have side fenestrations facing the membrane, which are likely the entrance for LAs to induce tonic block. In this review, we will focus on the effects of LA binding on fast inactivation and use-dependent inhibition in the light of the proposed new allosteric mechanism of fast inactivation. We will elaborate on subtype and species specificity and provide insights into modelling approaches that will help identify the exact molecular binding orientation, access pathways and pharmacokinetics. With this comprehensive overview, we will provide new perspectives in the use of the drug, both clinically and as a tool for basic ion channel research.
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Affiliation(s)
- Jannis Körner
- Institute of Physiology, Aachen, Germany.,Clinic of Anesthesiology, Medical Faculty, Uniklinik RWTH Aachen, Aachen, Germany
| | - Simone Albani
- Institute for Neuroscience and Medicine (INM-9/IAS-5), Forschungszentrum Jülich, Jülich, Germany.,Faculty of Mathematics, Computer Science and Natural Sciences, RWTH Aachen, Aachen, Germany
| | | | - Anna B Roehl
- Clinic of Anesthesiology, Medical Faculty, Uniklinik RWTH Aachen, Aachen, Germany
| | - Giulia Rossetti
- Institute for Neuroscience and Medicine (INM-9/IAS-5), Forschungszentrum Jülich, Jülich, Germany.,Jülich Supercomputing Center (JSC), Forschungszentrum Jülich, Aachen, Germany.,Department of Neurology, University Hospital Aachen, RWTH Aachen University, Aachen, Germany
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13
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Lin YC, Lai YC, Lin TH, Yang YC, Kuo CC. Selective stabilization of the intermediate inactivated Na+ channel by the new-generation anticonvulsant rufinamide. Biochem Pharmacol 2022; 197:114928. [DOI: 10.1016/j.bcp.2022.114928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 11/27/2022]
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14
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Tao E, Corry B. Characterizing fenestration size in sodium channel subtypes and their accessibility to inhibitors. Biophys J 2022; 121:193-206. [PMID: 34958776 PMCID: PMC8790208 DOI: 10.1016/j.bpj.2021.12.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 12/07/2021] [Accepted: 12/16/2021] [Indexed: 01/21/2023] Open
Abstract
Voltage-gated sodium channels (Nav) underlie the electrical activity of nerve and muscle cells. Humans have nine different subtypes of these channels, which are the target of small-molecule inhibitors commonly used to treat a range of conditions. Structural studies have identified four lateral fenestrations within the Nav pore module that have been shown to influence Nav pore blocker access during resting-state inhibition. However, the structural differences among the nine subtypes are still unclear. In particular, the dimensions of the four individual fenestrations across the Nav subtypes and their differential accessibility to pore blockers is yet to be characterized. To address this, we applied classical molecular dynamics simulations to study the recently published structures of Nav1.1, Nav1.2, Nav1.4, Nav1.5, and Nav1.7. Although there is significant variability in the bottleneck sizes of the Nav fenestrations, the subtypes follow a common pattern, with wider DI-II and DIII-IV fenestrations, a more restricted DII-III fenestration, and the most restricted DI-IV fenestration. We further identify the key bottleneck residues in each fenestration and show that the motions of aromatic residue sidechains govern the bottleneck radii. Well-tempered metadynamics simulations of Nav1.4 and Nav1.5 in the presence of the pore blocker lidocaine also support the DI-II fenestration being the most likely access route for drugs. Our computational results provide a foundation for future in vitro experiments examining the route of drug access to sodium channels. Understanding the fenestrations and their accessibility to drugs is critical for future analyses of diseases mutations across different sodium channel subtypes, with the potential to inform pharmacological development of resting-state inhibitors and subtype-selective drug design.
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Affiliation(s)
- Elaine Tao
- Research School of Biology, Australian National University, Canberra, Australia
| | - Ben Corry
- Research School of Biology, Australian National University, Canberra, Australia.
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15
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Nguyen PT, Nguyen HM, Wagner KM, Stewart RG, Singh V, Thapa P, Chen YJ, Lillya MW, Ton AT, Kondo R, Ghetti A, Pennington MW, Hammock B, Griffith TN, Sack JT, Wulff H, Yarov-Yarovoy V. Computational design of peptides to target Na V1.7 channel with high potency and selectivity for the treatment of pain. eLife 2022; 11:81727. [PMID: 36576241 PMCID: PMC9831606 DOI: 10.7554/elife.81727] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022] Open
Abstract
The voltage-gated sodium NaV1.7 channel plays a key role as a mediator of action potential propagation in C-fiber nociceptors and is an established molecular target for pain therapy. ProTx-II is a potent and moderately selective peptide toxin from tarantula venom that inhibits human NaV1.7 activation. Here we used available structural and experimental data to guide Rosetta design of potent and selective ProTx-II-based peptide inhibitors of human NaV1.7 channels. Functional testing of designed peptides using electrophysiology identified the PTx2-3127 and PTx2-3258 peptides with IC50s of 7 nM and 4 nM for hNaV1.7 and more than 1000-fold selectivity over human NaV1.1, NaV1.3, NaV1.4, NaV1.5, NaV1.8, and NaV1.9 channels. PTx2-3127 inhibits NaV1.7 currents in mouse and human sensory neurons and shows efficacy in rat models of chronic and thermal pain when administered intrathecally. Rationally designed peptide inhibitors of human NaV1.7 channels have transformative potential to define a new class of biologics to treat pain.
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Affiliation(s)
- Phuong T Nguyen
- Department of Physiology and Membrane Biology, University of California DavisDavisUnited States
| | - Hai M Nguyen
- Department of Pharmacology, University of California DavisDavisUnited States
| | - Karen M Wagner
- Department of Entomology and Nematology & Comprehensive Cancer Center, University of California DavisDavisUnited States
| | - Robert G Stewart
- Department of Physiology and Membrane Biology, University of California DavisDavisUnited States
| | - Vikrant Singh
- Department of Pharmacology, University of California DavisDavisUnited States
| | - Parashar Thapa
- Department of Physiology and Membrane Biology, University of California DavisDavisUnited States
| | - Yi-Je Chen
- Department of Pharmacology, University of California DavisDavisUnited States
| | - Mark W Lillya
- Department of Physiology and Membrane Biology, University of California DavisDavisUnited States
| | | | | | | | | | - Bruce Hammock
- Department of Entomology and Nematology & Comprehensive Cancer Center, University of California DavisDavisUnited States
| | - Theanne N Griffith
- Department of Physiology and Membrane Biology, University of California DavisDavisUnited States
| | - Jon T Sack
- Department of Physiology and Membrane Biology, University of California DavisDavisUnited States,Department of Anesthesiology and Pain Medicine, University of California DavisDavisUnited States
| | - Heike Wulff
- Department of Pharmacology, University of California DavisDavisUnited States
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California DavisDavisUnited States,Department of Anesthesiology and Pain Medicine, University of California DavisDavisUnited States,Biophysics Graduate Group, University of California DavisDavisUnited States
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16
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Differences in local anaesthetic and antiepileptic binding in the inactivated state of human sodium channel Nav1.4. Biophys J 2021; 120:5553-5563. [PMID: 34774501 DOI: 10.1016/j.bpj.2021.11.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/27/2021] [Accepted: 11/05/2021] [Indexed: 11/22/2022] Open
Abstract
Voltage-gated sodium channels play a vital role in nerve and muscle cells, enabling them to encode and transmit electrical signals. Currently, there exist several classes of drugs that aim to inhibit these channels for therapeutic purposes, including local anesthetics, antiepileptics and antiarrhythmics. However, sodium-channel-inhibiting drugs lack subtype specificity; instead, they inhibit all sodium channels in the human body. Improving understanding of the mechanisms of binding of existing nonselective drugs is important in providing insight into how subtype-selective drugs could be developed. This study used molecular dynamics simulations to investigate the binding of the antiepileptics carbamazepine and lamotrigine and the local anesthetic lidocaine in neutral and charged states to the recently resolved human Nav1.4 channel. Replica exchange solute tempering was used to enable greater sampling of each compound within the pore. It was found that all four compounds show similarities in their binding sites within the pore. However, the positions of the carbamazepine and lamotrigine did not occlude the center of the pore but preferentially bound to homologous domain DII and DIII. The charged and neutral forms of lidocaine positioned themselves more centrally in the pore, with more common interactions with DIV. The best localized binding site was for charged lidocaine, whose aromatic moiety interacted with Y1593, whereas the amine projected toward the selectivity filter. Comparisons with our previous simulations and published structures highlight potential differences between tonic and use-dependent block related to conformational changes occurring in the pore.
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17
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Milani G, Cavalluzzi MM, Altamura C, Santoro A, Perrone M, Muraglia M, Colabufo NA, Corbo F, Casalino E, Franchini C, Pisano I, Desaphy J, Carrieri A, Carocci A, Lentini G. Bioisosteric Modification of To042: Synthesis and Evaluation of Promising Use-Dependent Inhibitors of Voltage-Gated Sodium Channels. ChemMedChem 2021; 16:3588-3599. [PMID: 34519427 PMCID: PMC9293070 DOI: 10.1002/cmdc.202100496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 09/01/2021] [Indexed: 11/07/2022]
Abstract
Three analogues of To042, a tocainide-related lead compound recently reported for the treatment of myotonia, were synthesized and evaluated in vitro as skeletal muscle sodium channel blockers possibly endowed with enhanced use-dependent behavior. Patch-clamp experiments on hNav1.4 expressed in HEK293 cells showed that N-[(naphthalen-1-yl)methyl]-4-[(2,6-dimethyl)phenoxy]butan-2-amine, the aryloxyalkyl bioisostere of To042, exerted a higher use-dependent block than To042 thus being able to preferentially block the channels in over-excited membranes while preserving healthy tissue function. It also showed the lowest active transport across BBB according to the results of P-glycoprotein (P-gp) interacting activity evaluation and the highest cytoprotective effect on HeLa cells. Quantum mechanical calculations and dockings gave insights on the most probable conformation of the aryloxyalkyl bioisostere of To042 in solution and the target residues involved in the binding, respectively. Both approaches indicated the conformations that might be adopted in both the unbound and bound state of the ligand. Overall, N-[(naphthalen-1-yl)methyl]-4-[(2,6-dimethyl)phenoxy]butan-2-amine exhibits an interesting toxico-pharmacological profile and deserves further investigation.
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Affiliation(s)
- Gualtiero Milani
- Department of Pharmacy – Pharmaceutical SciencesUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
| | - Maria Maddalena Cavalluzzi
- Department of Pharmacy – Pharmaceutical SciencesUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
| | - Concetta Altamura
- Department of Biomedical Sciences and Human OncologySchool of MedicineUniversity of Bari Aldo Moro PoliclinicoPiazza Giulio Cesare70124BariItaly
| | - Antonella Santoro
- Department of Bioscience, Biotechnology and BiopharmaceuticsUniversity of Bari Aldo MoroVia Orabona 470125BariItaly
| | - Mariagrazia Perrone
- Department of Pharmacy – Pharmaceutical SciencesUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
| | - Marilena Muraglia
- Department of Pharmacy – Pharmaceutical SciencesUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
| | - Nicola Antonio Colabufo
- Department of Pharmacy – Pharmaceutical SciencesUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
| | - Filomena Corbo
- Department of Pharmacy – Pharmaceutical SciencesUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
| | - Elisabetta Casalino
- Department of Veterinary MedicineUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
| | - Carlo Franchini
- Department of Pharmacy – Pharmaceutical SciencesUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
| | - Isabella Pisano
- Department of Bioscience, Biotechnology and BiopharmaceuticsUniversity of Bari Aldo MoroVia Orabona 470125BariItaly
| | - Jean‐François Desaphy
- Department of Biomedical Sciences and Human OncologySchool of MedicineUniversity of Bari Aldo Moro PoliclinicoPiazza Giulio Cesare70124BariItaly
| | - Antonio Carrieri
- Department of Pharmacy – Pharmaceutical SciencesUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
| | - Alessia Carocci
- Department of Pharmacy – Pharmaceutical SciencesUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
| | - Giovanni Lentini
- Department of Pharmacy – Pharmaceutical SciencesUniversity of Bari Aldo MoroVia E. Orabona 470125BariItaly
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18
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Angsutararux P, Kang PW, Zhu W, Silva JR. Conformations of voltage-sensing domain III differentially define NaV channel closed- and open-state inactivation. J Gen Physiol 2021; 153:212533. [PMID: 34347027 PMCID: PMC8348240 DOI: 10.1085/jgp.202112891] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/14/2021] [Indexed: 11/21/2022] Open
Abstract
Voltage-gated Na+ (NaV) channels underlie the initiation and propagation of action potentials (APs). Rapid inactivation after NaV channel opening, known as open-state inactivation, plays a critical role in limiting the AP duration. However, NaV channel inactivation can also occur before opening, namely closed-state inactivation, to tune the cellular excitability. The voltage-sensing domain (VSD) within repeat IV (VSD-IV) of the pseudotetrameric NaV channel α-subunit is known to be a critical regulator of NaV channel inactivation. Yet, the two processes of open- and closed-state inactivation predominate at different voltage ranges and feature distinct kinetics. How inactivation occurs over these different ranges to give rise to the complexity of NaV channel dynamics is unclear. Past functional studies and recent cryo-electron microscopy structures, however, reveal significant inactivation regulation from other NaV channel components. In this Hypothesis paper, we propose that the VSD of NaV repeat III (VSD-III), together with VSD-IV, orchestrates the inactivation-state occupancy of NaV channels by modulating the affinity of the intracellular binding site of the IFMT motif on the III-IV linker. We review and outline substantial evidence that VSD-III activates in two distinct steps, with the intermediate and fully activated conformation regulating closed- and open-state inactivation state occupancy by altering the formation and affinity of the IFMT crevice. A role of VSD-III in determining inactivation-state occupancy and recovery from inactivation suggests a regulatory mechanism for the state-dependent block by small-molecule anti-arrhythmic and anesthetic therapies.
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Affiliation(s)
- Paweorn Angsutararux
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO
| | - Po Wei Kang
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO
| | - Wandi Zhu
- Department of Medicine, Brigham and Women's Hospital, Boston, MA
| | - Jonathan R Silva
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO
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19
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Li Z, Jin X, Wu T, Huang G, Wu K, Lei J, Pan X, Yan N. Structural Basis for Pore Blockade of the Human Cardiac Sodium Channel Na v 1.5 by the Antiarrhythmic Drug Quinidine*. Angew Chem Int Ed Engl 2021; 60:11474-11480. [PMID: 33684260 DOI: 10.1002/anie.202102196] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Indexed: 12/19/2022]
Abstract
Nav 1.5, the primary voltage-gated Na+ (Nav ) channel in heart, is a major target for class I antiarrhythmic agents. Here we present the cryo-EM structure of full-length human Nav 1.5 bound to quinidine, a class Ia antiarrhythmic drug, at 3.3 Å resolution. Quinidine is positioned right beneath the selectivity filter in the pore domain and coordinated by residues from repeats I, III, and IV. Pore blockade by quinidine is achieved through both direct obstruction of the ion permeation path and induced rotation of an invariant Tyr residue that tightens the intracellular gate. Structural comparison with a truncated rat Nav 1.5 in the presence of flecainide, a class Ic agent, reveals distinct binding poses for the two antiarrhythmics within the pore domain. Our work reported here, along with previous studies, reveals the molecular basis for the mechanism of action of class I antiarrhythmic drugs.
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Affiliation(s)
- Zhangqiang Li
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xueqin Jin
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Tong Wu
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Gaoxingyu Huang
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, Hangzhou, 310024, Zhejiang Province, China
| | - Kun Wu
- Medical Research Center, Beijing Key Laboratory of Cardiopulmonary Cerebral Resuscitation, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China
| | - Jianlin Lei
- Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xiaojing Pan
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Nieng Yan
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
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20
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Li Z, Jin X, Wu T, Huang G, Wu K, Lei J, Pan X, Yan N. Structural Basis for Pore Blockade of the Human Cardiac Sodium Channel Na
v
1.5 by the Antiarrhythmic Drug Quinidine**. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102196] [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]
Affiliation(s)
- Zhangqiang Li
- State Key Laboratory of Membrane Biology Beijing Advanced Innovation Center for Structural Biology Tsinghua-Peking Joint Center for Life Science School of Life Sciences Tsinghua University Beijing 100084 China
| | - Xueqin Jin
- State Key Laboratory of Membrane Biology Beijing Advanced Innovation Center for Structural Biology Tsinghua-Peking Joint Center for Life Science School of Life Sciences Tsinghua University Beijing 100084 China
| | - Tong Wu
- State Key Laboratory of Membrane Biology Beijing Advanced Innovation Center for Structural Biology Tsinghua-Peking Joint Center for Life Science School of Life Sciences Tsinghua University Beijing 100084 China
| | - Gaoxingyu Huang
- Key Laboratory of Structural Biology of Zhejiang Province Institute of Biology, Westlake Institute for Advanced Study School of Life Sciences Westlake University Hangzhou 310024 Zhejiang Province China
| | - Kun Wu
- Medical Research Center Beijing Key Laboratory of Cardiopulmonary Cerebral Resuscitation Beijing Chao-Yang Hospital Capital Medical University Beijing 100020 China
| | - Jianlin Lei
- Technology Center for Protein Sciences Ministry of Education Key Laboratory of Protein Sciences School of Life Sciences Tsinghua University Beijing 100084 China
| | - Xiaojing Pan
- State Key Laboratory of Membrane Biology Beijing Advanced Innovation Center for Structural Biology Tsinghua-Peking Joint Center for Life Science School of Life Sciences Tsinghua University Beijing 100084 China
| | - Nieng Yan
- Department of Molecular Biology Princeton University Princeton NJ 08544 USA
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21
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Zhorov BS. Structure of Sodium and Calcium Channels
with Ligands. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021020150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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22
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Gambeta E, Chichorro JG, Zamponi GW. Trigeminal neuralgia: An overview from pathophysiology to pharmacological treatments. Mol Pain 2021; 16:1744806920901890. [PMID: 31908187 PMCID: PMC6985973 DOI: 10.1177/1744806920901890] [Citation(s) in RCA: 129] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The trigeminal nerve (V) is the fifth and largest of all cranial nerves, and it is responsible for detecting sensory stimuli that arise from the craniofacial area. The nerve is divided into three branches: ophthalmic (V1), maxillary (V2), and mandibular (V3); their cell bodies are located in the trigeminal ganglia and they make connections with second-order neurons in the trigeminal brainstem sensory nuclear complex. Ascending projections via the trigeminothalamic tract transmit information to the thalamus and other brain regions responsible for interpreting sensory information. One of the most common forms of craniofacial pain is trigeminal neuralgia. Trigeminal neuralgia is characterized by sudden, brief, and excruciating facial pain attacks in one or more of the V branches, leading to a severe reduction in the quality of life of affected patients. Trigeminal neuralgia etiology can be classified into idiopathic, classic, and secondary. Classic trigeminal neuralgia is associated with neurovascular compression in the trigeminal root entry zone, which can lead to demyelination and a dysregulation of voltage-gated sodium channel expression in the membrane. These alterations may be responsible for pain attacks in trigeminal neuralgia patients. The antiepileptic drugs carbamazepine and oxcarbazepine are the first-line pharmacological treatment for trigeminal neuralgia. Their mechanism of action is a modulation of voltage-gated sodium channels, leading to a decrease in neuronal activity. Although carbamazepine and oxcarbazepine are the first-line treatment, other drugs may be useful for pain control in trigeminal neuralgia. Among them, the anticonvulsants gabapentin, pregabalin, lamotrigine and phenytoin, baclofen, and botulinum toxin type A can be coadministered with carbamazepine or oxcarbazepine for a synergistic approach. New pharmacological alternatives are being explored such as the active metabolite of oxcarbazepine, eslicarbazepine, and the new Nav1.7 blocker vixotrigine. The pharmacological profiles of these drugs are addressed in this review.
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Affiliation(s)
- Eder Gambeta
- Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Juliana G Chichorro
- Department of Pharmacology, Biological Sciences Sector, Federal University of Parana, Curitiba, Brazil
| | - Gerald W. Zamponi
- Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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23
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Nakajima T, Dharmawan T, Kawabata-Iwakawa R, Tamura S, Hasegawa H, Kobari T, Ota M, Tange S, Nishiyama M, Kaneko Y, Kurabayashi M. Reduced current density, partially rescued by mexiletine, and depolarizing shift in activation of SCN5A W374G channels as a cause of severe form of Brugada syndrome. Ann Noninvasive Electrocardiol 2021; 26:e12828. [PMID: 33463855 PMCID: PMC8164156 DOI: 10.1111/anec.12828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/14/2020] [Accepted: 01/04/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND SCN5A-related Brugada syndrome (BrS) can be caused by multiple mechanisms including trafficking defects and altered channel gating properties. Most SCN5A mutations at pore region cause trafficking defects, and some of them can be rescued by mexiletine (MEX). OBJECTIVE We recently encountered symptomatic siblings with BrS and sought to identify a responsible mutation and reveal its biophysical defects. METHODS Target panel sequencing was performed. Wild-type (WT) or identified mutant SCN5A was transfected into tsA201 cells. After incubation of transfected cells with or without 0.1 mM MEX for 24-36 hr, whole-cell sodium currents (INa ) were recorded using patch-clamp techniques. RESULTS The proband was 29-year-old male who experienced cardiopulmonary arrest. Later, his 36-year-old sister, who had been suffering from recurrent episodes of syncope since 12 years, was diagnosed with BrS. An SCN5A W374G mutation, located at pore region of domain 1 (D1 pore), was identified in both. The peak density of W374G-INa was markedly reduced (WT: 521 ± 38 pA/pF, W374G: 60 ± 10 pA/pF, p < .01), and steady-state activation (SSA) was shifted to depolarizing potentials compared with WT-INa (V1/2 -WT: -39.1 ± 0.8 mV, W374G: -30.9 ± 1.1 mV, p < .01). Incubation of W374G-transfected cells with MEX (W374G-MEX) increased INa density, but it was still reduced compared with WT-INa (W374G-MEX: 174 ± 19 pA/pF, p < .01 versus W374G, p < .01 versus WT). The SSA of W374G-MEX-INa was comparable to W374G-INa (V1/2 -W374G-MEX: -31.6 ± 0.7 mV, P = NS). CONCLUSIONS Reduced current density, possibly due to a trafficking defect, and depolarizing shift in activation of SCN5A W374G are underlying biophysical defects in this severe form of BrS. Trafficking defects of SCN5A mutations at D1 pore may be commonly rescued by MEX.
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Affiliation(s)
- Tadashi Nakajima
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Tommy Dharmawan
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Reika Kawabata-Iwakawa
- Division of Integrated Oncology Research, Gunma University Initiative for Advanced Research, Maebashi, Japan
| | - Shuntaro Tamura
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hiroshi Hasegawa
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Takashi Kobari
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Masaki Ota
- Department of Cardiovascular Medicine, National Hospital Organization Takasaki General Medical Center, Takasaki, Japan
| | - Shoichi Tange
- Department of Cardiovascular Medicine, Japanese Red Cross Maebashi Hospital, Maebashi, Japan
| | | | - Yoshiaki Kaneko
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Masahiko Kurabayashi
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
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24
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Peng YS, Wu HT, Lai YC, Chen JL, Yang YC, Kuo CC. Inhibition of neuronal Na+ currents by lacosamide: Differential binding affinity and kinetics to different inactivated states. Neuropharmacology 2020; 179:108266. [DOI: 10.1016/j.neuropharm.2020.108266] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 07/06/2020] [Accepted: 07/28/2020] [Indexed: 10/23/2022]
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25
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Labau JIR, Estacion M, Tanaka BS, de Greef BTA, Hoeijmakers JGJ, Geerts M, Gerrits MM, Smeets HJM, Faber CG, Merkies ISJ, Lauria G, Dib-Hajj SD, Waxman SG. Differential effect of lacosamide on Nav1.7 variants from responsive and non-responsive patients with small fibre neuropathy. Brain 2020; 143:771-782. [PMID: 32011655 PMCID: PMC7089662 DOI: 10.1093/brain/awaa016] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/13/2019] [Accepted: 12/06/2019] [Indexed: 12/20/2022] Open
Abstract
Small fibre neuropathy is a common pain disorder, which in many cases fails to respond to treatment with existing medications. Gain-of-function mutations of voltage-gated sodium channel Nav1.7 underlie dorsal root ganglion neuronal hyperexcitability and pain in a subset of patients with small fibre neuropathy. Recent clinical studies have demonstrated that lacosamide, which blocks sodium channels in a use-dependent manner, attenuates pain in some patients with Nav1.7 mutations; however, only a subgroup of these patients responded to the drug. Here, we used voltage-clamp recordings to evaluate the effects of lacosamide on five Nav1.7 variants from patients who were responsive or non-responsive to treatment. We show that, at the clinically achievable concentration of 30 μM, lacosamide acts as a potent sodium channel inhibitor of Nav1.7 variants carried by responsive patients, via a hyperpolarizing shift of voltage-dependence of both fast and slow inactivation and enhancement of use-dependent inhibition. By contrast, the effects of lacosamide on slow inactivation and use-dependence in Nav1.7 variants from non-responsive patients were less robust. Importantly, we found that lacosamide selectively enhances fast inactivation only in variants from responders. Taken together, these findings begin to unravel biophysical underpinnings that contribute to responsiveness to lacosamide in patients with small fibre neuropathy carrying select Nav1.7 variants.
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Affiliation(s)
- Julie I R Labau
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06510, USA.,Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT 06510, USA.,Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516, USA.,Department of Neurology, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Genetics and Cell Biology, Clinical Genomics Unit, Maastricht University, Maastricht, The Netherlands
| | - Mark Estacion
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06510, USA.,Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT 06510, USA.,Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516, USA
| | - Brian S Tanaka
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06510, USA.,Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT 06510, USA.,Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516, USA
| | - Bianca T A de Greef
- Department of Neurology, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Clinical Epidemiology and Medical Technology Assessment (KEMTA), Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Janneke G J Hoeijmakers
- Department of Neurology, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Margot Geerts
- Department of Neurology, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Monique M Gerrits
- Department of Clinical Genetics, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Hubert J M Smeets
- Department of Genetics and Cell Biology, Clinical Genomics Unit, Maastricht University, Maastricht, The Netherlands
| | - Catharina G Faber
- Department of Neurology, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Ingemar S J Merkies
- Department of Neurology, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Neurology, St. Elisabeth Hospital, Willemstad, Curaçao
| | - Giuseppe Lauria
- Neuroalgology Unit, IRCCS Foundation, "Carlo Besta" Neurological Institute, Milan, Italy.,Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Italy
| | - Sulayman D Dib-Hajj
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06510, USA.,Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT 06510, USA.,Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516, USA
| | - Stephen G Waxman
- Department of Neurology, Yale University School of Medicine, New Haven, CT 06510, USA.,Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT 06510, USA.,Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516, USA
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26
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Xenakis MN, Kapetis D, Yang Y, Heijman J, Waxman SG, Lauria G, Faber CG, Smeets HJ, Westra RL, Lindsey PJ. Cumulative hydropathic topology of a voltage-gated sodium channel at atomic resolution. Proteins 2020; 88:1319-1328. [PMID: 32447794 DOI: 10.1002/prot.25951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 03/11/2020] [Accepted: 05/14/2020] [Indexed: 11/10/2022]
Abstract
Voltage-gated sodium channels (NavChs) are biological pores that control the flow of sodium ions through the cell membrane. In humans, mutations in genes encoding NavChs can disrupt physiological cellular activity thus leading to a wide spectrum of diseases. Here, we present a topological connection between the functional architecture of a NavAb bacterial channel and accumulation of atomic hydropathicity around its pore. This connection is established via a scaling analysis methodology that elucidates how intrachannel hydropathic density variations translate into hydropathic dipole field configurations along the pore. Our findings suggest the existence of a nonrandom cumulative hydropathic topology that is organized parallel to the membrane surface so that pore's stability, as well as, gating behavior are guaranteed. Given the biophysical significance of the hydropathic effect, our study seeks to provide a computational framework for studying cumulative hydropathic topological properties of NavChs and pore-forming proteins in general.
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Affiliation(s)
- Markos N Xenakis
- Department of Genetics and Cell Biology, Section Clinical Genomics, Maastricht University, Maastricht, the Netherlands.,School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, the Netherlands
| | - Dimos Kapetis
- Neuroalgology Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Yang Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University College of Pharmacy, West Lafayette, Indiana, USA.,Purdue Institute for Integrative Neuroscience, West Lafayette, Indiana, USA
| | - Jordi Heijman
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, the Netherlands
| | - Stephen G Waxman
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut, USA.,Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, USA
| | - Giuseppe Lauria
- Neuroalgology Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy.,Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy
| | - Catharina G Faber
- Department of Neurology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Hubert J Smeets
- Department of Genetics and Cell Biology, Section Clinical Genomics, Maastricht University, Maastricht, the Netherlands.,School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, the Netherlands
| | - Ronald L Westra
- Department of Data Science and Knowledge Engineering, Maastricht University, Maastricht, the Netherlands
| | - Patrick J Lindsey
- Department of Genetics and Cell Biology, Section Clinical Genomics, Maastricht University, Maastricht, the Netherlands.,School for Oncology and Developmental Biology (GROW), Maastricht University, Maastricht, the Netherlands
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27
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Van Theemsche KM, Van de Sande DV, Snyders DJ, Labro AJ. Hydrophobic Drug/Toxin Binding Sites in Voltage-Dependent K + and Na + Channels. Front Pharmacol 2020; 11:735. [PMID: 32499709 PMCID: PMC7243439 DOI: 10.3389/fphar.2020.00735] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 05/04/2020] [Indexed: 12/26/2022] Open
Abstract
In the Nav channel family the lipophilic drugs/toxins binding sites and the presence of fenestrations in the channel pore wall are well defined and categorized. No such classification exists in the much larger Kv channel family, although certain lipophilic compounds seem to deviate from binding to well-known hydrophilic binding sites. By mapping different compound binding sites onto 3D structures of Kv channels, there appear to be three distinct lipid-exposed binding sites preserved in Kv channels: the front and back side of the pore domain, and S2-S3/S3-S4 clefts. One or a combination of these sites is most likely the orthologous equivalent of neurotoxin site 5 in Nav channels. This review describes the different lipophilic binding sites and location of pore wall fenestrations within the Kv channel family and compares it to the knowledge of Nav channels.
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Affiliation(s)
- Kenny M Van Theemsche
- Laboratory of Molecular, Cellular, and Network Excitability, University of Antwerp, Antwerp, Belgium
| | - Dieter V Van de Sande
- Laboratory of Molecular, Cellular, and Network Excitability, University of Antwerp, Antwerp, Belgium
| | - Dirk J Snyders
- Laboratory of Molecular, Cellular, and Network Excitability, University of Antwerp, Antwerp, Belgium
| | - Alain J Labro
- Laboratory of Molecular, Cellular, and Network Excitability, University of Antwerp, Antwerp, Belgium
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28
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Brewer KR, Kuenze G, Vanoye CG, George AL, Meiler J, Sanders CR. Structures Illuminate Cardiac Ion Channel Functions in Health and in Long QT Syndrome. Front Pharmacol 2020; 11:550. [PMID: 32431610 PMCID: PMC7212895 DOI: 10.3389/fphar.2020.00550] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/09/2020] [Indexed: 12/13/2022] Open
Abstract
The cardiac action potential is critical to the production of a synchronized heartbeat. This electrical impulse is governed by the intricate activity of cardiac ion channels, among them the cardiac voltage-gated potassium (Kv) channels KCNQ1 and hERG as well as the voltage-gated sodium (Nav) channel encoded by SCN5A. Each channel performs a highly distinct function, despite sharing a common topology and structural components. These three channels are also the primary proteins mutated in congenital long QT syndrome (LQTS), a genetic condition that predisposes to cardiac arrhythmia and sudden cardiac death due to impaired repolarization of the action potential and has a particular proclivity for reentrant ventricular arrhythmias. Recent cryo-electron microscopy structures of human KCNQ1 and hERG, along with the rat homolog of SCN5A and other mammalian sodium channels, provide atomic-level insight into the structure and function of these proteins that advance our understanding of their distinct functions in the cardiac action potential, as well as the molecular basis of LQTS. In this review, the gating, regulation, LQTS mechanisms, and pharmacological properties of KCNQ1, hERG, and SCN5A are discussed in light of these recent structural findings.
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Affiliation(s)
- Kathryn R. Brewer
- Center for Structural Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, United States
- Department of Biochemistry, Vanderbilt University, Nashville, TN, United States
| | - Georg Kuenze
- Center for Structural Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, United States
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Carlos G. Vanoye
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Alfred L. George
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, United States
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Department of Pharmacology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, United States
- Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
| | - Charles R. Sanders
- Center for Structural Biology, Vanderbilt University School of Medicine Basic Sciences, Nashville, TN, United States
- Department of Biochemistry, Vanderbilt University, Nashville, TN, United States
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29
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Jo S, Bean BP. Lidocaine Binding Enhances Inhibition of Nav1.7 Channels by the Sulfonamide PF-05089771. Mol Pharmacol 2020; 97:377-383. [PMID: 32193331 DOI: 10.1124/mol.119.118380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/27/2020] [Indexed: 11/22/2022] Open
Abstract
PF-05089771 is an aryl sulfonamide Nav1.7 channel blocker that binds to the inactivated state of Nav1.7 channels with high affinity but binds only weakly to channels in the resting state. Such aryl sulfonamide Nav1.7 channel blockers bind to the extracellular surface of the S1-S4 voltage-sensor segment of homologous Domain 4, whose movement is associated with inactivation. This binding site is different from that of classic sodium channel inhibitors like lidocaine, which also bind with higher affinity to the inactivated state than the resting state but bind at a site within the pore of the channel. The common dependence on gating state with distinct binding sites raises the possibility that inhibition by aryl sulfonamides and by classic local anesthetics might show an interaction mediated by their mutual state dependence. We tested this possibility by examining the state-dependent inhibition by PF-05089771 and lidocaine of human Nav1.7 channels expressed in human embryonic kidney 293 cells. At -80 mV, where a small fraction of channels are in an inactivated state under drug-free conditions, inhibition by PF-05089771 was both enhanced and speeded in the presence of lidocaine. The results suggest that lidocaine binding to the channel enhances PF-05089771 inhibition by altering the equilibrium between resting states (with D4S4 in the inner position) and inactivated states (with D4S4 in the outer position). The gating state-mediated interaction between the compounds illustrates a principle applicable to many state-dependent agents. SIGNIFICANCE STATEMENT: The results show that lidocaine enhances the degree and rate of inhibition of Nav1.7 channels by the aryl sulfonamide compound PF-05089771, consistent with state-dependent binding by lidocaine increasing the fraction of channels presenting a high-affinity binding site for PF-05089771 and suggesting that combinations of agents targeted to the pore-region binding site of lidocaine and the external binding site of aryl sulfonamides may have synergistic actions.
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Affiliation(s)
- Sooyeon Jo
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts
| | - Bruce P Bean
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts
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30
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Craig RA, Garrison CE, Nguyen PT, Yarov-Yarovoy V, Du Bois J. Veratridine: A Janus-Faced Modulator of Voltage-Gated Sodium Ion Channels. ACS Chem Neurosci 2020; 11:418-426. [PMID: 31951114 DOI: 10.1021/acschemneuro.9b00621] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Voltage-gated sodium ion channels (NaVs) are integral to both neuronal and muscular signaling and are a primary target for a number of proteinaceous and small molecule toxins. Included among these neurotoxins is veratridine (VTD), a C-nor-D homosteroidal alkaloid from the seeds of members of the Veratrum genus. VTD binds to NaV within the pore region, causing a hyperpolarizing shift in the activation threshold in addition to reducing peak current. We have characterized the activity of VTD against heterologously expressed rat NaV1.4 and have demonstrated that VTD acts on the channel as either an agonist or antagonist depending on the nature of the electrophysiological stimulation protocol. Structure-activity studies with VTD and VTD derivatives against NaV mutants show that the functional duality of VTD can be decoupled. These findings suggest that the dichotomous activity of VTD may derive from two distinct, use-dependent binding orientations of the toxin.
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Affiliation(s)
- Robert A. Craig
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Catherine E. Garrison
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Phuong T. Nguyen
- Department of Physiology and Membrane Biology, University of California, Davis, California 95616, United States
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, California 95616, United States
| | - J. Du Bois
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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31
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Beard JM, Shockett PE, O'Reilly JP. Substituted cysteine scanning in D1-S6 of the sodium channel hNav1.4 alters kinetics and structural interactions of slow inactivation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183129. [PMID: 31738900 DOI: 10.1016/j.bbamem.2019.183129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 10/25/2019] [Accepted: 11/08/2019] [Indexed: 10/25/2022]
Abstract
Slow inactivation in voltage-gated Na+ channels (Navs) plays an important physiological role in excitable tissues (muscle, heart, nerves) and mutations that disrupt Nav slow inactivation can result in pathophysiologies (myotonia, arrhythmias, epilepsy). While the molecular mechanisms responsible for slow inactivation remain elusive, previous studies have suggested a role for the pore-lining D1-S6 helix. The goals of this research were to determine if (1) cysteine substitutions in D1-S6 affect gating kinetics and (2) methanethiosulfonate ethylammonium (MTSEA) accessibility changes in different kinetic states. Site-directed mutagenesis in the human skeletal muscle isoform hNav1.4 was used to substitute cysteine for eleven amino acids in D1-S6 from L433 to L443. Mutants were expressed in HEK cells and recorded from with whole-cell patch clamp. All mutations affected one or more baseline kinetics of the sodium channel, including activation, fast inactivation, and slow inactivation. Substitution of cysteine (for nonpolar residues) adjacent to polar residues destabilized slow inactivation in G434C, F436C, I439C, and L441C. Cysteine substitution without adjacent polar residues enhanced slow inactivation in L438C and N440C, and disrupted possible H-bonds involving Y437:D4 S4-S5 and N440:D4-S6. MTSEA exposure in closed, fast-inactivated, or slow-inactivated states in most mutants had little-to-no effect. In I439C, MTSEA application in closed, fast-inactivated, and slow-inactivated states produced irreversible reduction in current, suggesting I439C accessibility to MTSEA in all three kinetic states. D1-S6 is important for Nav gating kinetics, stability of slow-inactivated state, structural contacts, and state-dependent positioning. However, prominent reconfiguration of D1-S6 may not occur in slow inactivation.
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Affiliation(s)
- Jonathan M Beard
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA, USA.
| | - Penny E Shockett
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA, USA.
| | - John P O'Reilly
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA, USA.
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32
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Catterall WA, Lenaeus MJ, Gamal El-Din TM. Structure and Pharmacology of Voltage-Gated Sodium and Calcium Channels. Annu Rev Pharmacol Toxicol 2020; 60:133-154. [PMID: 31537174 DOI: 10.1146/annurev-pharmtox-010818-021757] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Voltage-gated sodium and calcium channels are evolutionarily related transmembrane signaling proteins that initiate action potentials, neurotransmission, excitation-contraction coupling, and other physiological processes. Genetic or acquired dysfunction of these proteins causes numerous diseases, termed channelopathies, and sodium and calcium channels are the molecular targets for several major classes of drugs. Recent advances in the structural biology of these proteins using X-ray crystallography and cryo-electron microscopy have given new insights into the molecular basis for their function and pharmacology. Here we review this recent literature and integrate findings on sodium and calcium channels to reveal the structural basis for their voltage-dependent activation, fast and slow inactivation, ion conductance and selectivity, and complex pharmacology at the atomic level. We conclude with the theme that new understanding of the diseases and therapeutics of these channels will be derived from application of the emerging structural principles from these recent structural analyses.
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Affiliation(s)
- William A Catterall
- Department of Pharmacology and Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, Washington 98195, USA;
| | - Michael J Lenaeus
- Department of Pharmacology and Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, Washington 98195, USA;
| | - Tamer M Gamal El-Din
- Department of Pharmacology and Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, Washington 98195, USA;
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33
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Konoki K, Baden DG, Scheuer T, Catterall WA. Molecular Determinants of Brevetoxin Binding to Voltage-Gated Sodium Channels. Toxins (Basel) 2019; 11:toxins11090513. [PMID: 31484365 PMCID: PMC6784055 DOI: 10.3390/toxins11090513] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/30/2019] [Accepted: 08/30/2019] [Indexed: 12/19/2022] Open
Abstract
Brevetoxins are produced by dinoflagellates such as Karenia brevis in warm-water red tides and cause neurotoxic shellfish poisoning. They bind to voltage-gated sodium channels at neurotoxin receptor 5, making the channels more active by shifting the voltage-dependence of activation to more negative potentials and by slowing the inactivation process. Previous work using photoaffinity labeling identified binding to the IS6 and IVS5 transmembrane segments of the channel α subunit. We used alanine-scanning mutagenesis to identify molecular determinants for brevetoxin binding in these regions as well as adjacent regions IVS5-SS1 and IVS6. Most of the mutant channels containing single alanine substitutions expressed functional protein in tsA-201 cells and bound to the radioligand [42-3H]-PbTx3. Binding affinity for the great majority of mutant channels was indistinguishable from wild type. However, transmembrane segments IS6, IVS5 and IVS6 each contained 2 to 4 amino acid positions where alanine substitution resulted in a 2–3-fold reduction in brevetoxin affinity, and additional mutations caused a similar increase in brevetoxin affinity. These findings are consistent with a model in which brevetoxin binds to a protein cleft comprising transmembrane segments IS6, IVS5 and IVS6 and makes multiple distributed interactions with these α helices. Determination of brevetoxin affinity for Nav1.2, Nav1.4 and Nav1.5 channels showed that Nav1.5 channels had a characteristic 5-fold reduction in affinity for brevetoxin relative to the other channel isoforms, suggesting the interaction with sodium channels is specific despite the distributed binding determinants.
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Affiliation(s)
- Keiichi Konoki
- Department of Pharmacology, Box 357280, University of Washington, Seattle, WA 98195-7280, USA.
| | - Daniel G Baden
- Center for Marine Science, University of North Carolina, Wilmington, NC 28409, USA
| | - Todd Scheuer
- Department of Pharmacology, Box 357280, University of Washington, Seattle, WA 98195-7280, USA
| | - William A Catterall
- Department of Pharmacology, Box 357280, University of Washington, Seattle, WA 98195-7280, USA.
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34
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Flood E, Boiteux C, Lev B, Vorobyov I, Allen TW. Atomistic Simulations of Membrane Ion Channel Conduction, Gating, and Modulation. Chem Rev 2019; 119:7737-7832. [DOI: 10.1021/acs.chemrev.8b00630] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Emelie Flood
- School of Science, RMIT University, Melbourne, Victoria 3000, Australia
| | - Céline Boiteux
- School of Science, RMIT University, Melbourne, Victoria 3000, Australia
| | - Bogdan Lev
- School of Science, RMIT University, Melbourne, Victoria 3000, Australia
| | - Igor Vorobyov
- Department of Physiology & Membrane Biology/Department of Pharmacology, University of California, Davis, 95616, United States
| | - Toby W. Allen
- School of Science, RMIT University, Melbourne, Victoria 3000, Australia
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35
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León I, Lesarri A, Fernández JA. Evaluation of the aggregation process in a mixture of propofol and benzocaine. Phys Chem Chem Phys 2019; 21:3537-3544. [PMID: 30137107 DOI: 10.1039/c8cp04386h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report on a mass-resolved IR spectrosopic study on propofol-benzocaine aggregates. This is a complex system due to the several conformational isomers that both monomers may adopt and to the combination of functional groups they present, which allow the molecules to interact in many possible ways. However, our results demonstrate that a single conformation is favored for each stoichiometry. In the heterodimer, propofol acts as a proton donor to the ester group of benzocaine, while the whole cluster is stabilized by dispersive forces. These dispersive forces account for an important part of the system's stabilization energy as the calculations suggest. Propofol does not show any affinity for the amino group of benzocaine, even when a second molecule of propofol is introduced. These results demonstrate the difficulty in anticipating the aggregation preferences of even small organic molecules.
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Affiliation(s)
- I León
- Department of Physical Chemistry, Faculty of Science and Technology, University of the Basque Country, Barrio Sarriena s/n, 48940 Leioa, Spain.
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36
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Structural basis for antiarrhythmic drug interactions with the human cardiac sodium channel. Proc Natl Acad Sci U S A 2019; 116:2945-2954. [PMID: 30728299 PMCID: PMC6386684 DOI: 10.1073/pnas.1817446116] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Voltage-gated sodium channels play a central role in cellular excitability and are key targets for drug development. Recent breakthroughs in high-resolution cryo-electron microscopy protein structure determination, Rosetta computational protein structure modeling, and multimicrosecond molecular dynamics simulations are empowering advances in structural biology to study the atomistic details of channel−drug interactions. We used Rosetta structural computational modeling and molecular dynamics simulations to study the interactions of antiarrhythmic and local anesthetic drugs with cardiac sodium channel. Our results provide crucial atomic-scale mechanistic insights into the channel–drug interactions, necessary for the rational design of novel modulators of the human cardiac sodium channel to be used for the treatment of cardiac arrhythmias. The human voltage-gated sodium channel, hNaV1.5, is responsible for the rapid upstroke of the cardiac action potential and is target for antiarrhythmic therapy. Despite the clinical relevance of hNaV1.5-targeting drugs, structure-based molecular mechanisms of promising or problematic drugs have not been investigated at atomic scale to inform drug design. Here, we used Rosetta structural modeling and docking as well as molecular dynamics simulations to study the interactions of antiarrhythmic and local anesthetic drugs with hNaV1.5. These calculations revealed several key drug binding sites formed within the pore lumen that can simultaneously accommodate up to two drug molecules. Molecular dynamics simulations identified a hydrophilic access pathway through the intracellular gate and a hydrophobic access pathway through a fenestration between DIII and DIV. Our results advance the understanding of molecular mechanisms of antiarrhythmic and local anesthetic drug interactions with hNaV1.5 and will be useful for rational design of novel therapeutics.
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37
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Nakagawa H, Munakata T, Sunami A. Mexiletine Block of Voltage-Gated Sodium Channels: Isoform- and State-Dependent Drug-Pore Interactions. Mol Pharmacol 2018; 95:236-244. [PMID: 30593458 DOI: 10.1124/mol.118.114025] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 12/19/2018] [Indexed: 12/24/2022] Open
Abstract
Mexiletine is a class Ib antiarrhythmic drug and is also used clinically to reduce or prevent myotonia. In addition, mexiletine has neuroprotective effects in models of brain ischemia. We compared state-dependent affinities of mexiletine for Nav1.2, Nav1.4, and Nav1.5 and examined the effects of mutations of transmembrane segment S6 residues on mexiletine block of Nav1.5. Three channel isoforms had similar affinities of mexiletine for the rested state, and Nav1.4 and Nav1.5 had similar affinities for the open and inactivated states, while Nav1.2 had lower affinity for these states than Nav1.4 and Nav1.5. Mutational studies revealed that the largest affinity change was observed for an Ala substitution of Phe in domain IV S6. In our homology modeling based on the bacterial Na+ channel, mexiletine changed its location and orientation in the pore depending on the state of the channel, irrespective of the channel isoform. Mexiletine occurred in the upper part in the pore in the open state and lower in the closed state. High-affinity binding of mexiletine in the open states of Nav1.4 and Nav1.5 was caused by a π-π interaction with Phe, whereas mexiletine was located away from Phe in the open state of Nav1.2. These results provide crucial information on the mechanism of isoform differences in state-dependent block by local anesthetics and related drugs. Mexiletine at upper locations in the open state may effectively cause an electrostatic mechanism of block.
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Affiliation(s)
- Hiroki Nakagawa
- Department of Pharmaceutical Sciences, International University of Health and Welfare, Tochigi, Japan
| | - Tatsuo Munakata
- Department of Pharmaceutical Sciences, International University of Health and Welfare, Tochigi, Japan
| | - Akihiko Sunami
- Department of Pharmaceutical Sciences, International University of Health and Welfare, Tochigi, Japan
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38
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Fenestrations control resting-state block of a voltage-gated sodium channel. Proc Natl Acad Sci U S A 2018; 115:13111-13116. [PMID: 30518562 DOI: 10.1073/pnas.1814928115] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Potency of drug action is usually determined by binding to a specific receptor site on target proteins. In contrast to this conventional paradigm, we show here that potency of local anesthetics (LAs) and antiarrhythmic drugs (AADs) that block sodium channels is controlled by fenestrations that allow drug access to the receptor site directly from the membrane phase. Voltage-gated sodium channels initiate action potentials in nerve and cardiac muscle, where their hyperactivity causes pain and cardiac arrhythmia, respectively. LAs and AADs selectively block sodium channels in rapidly firing nerve and muscle cells to relieve these conditions. The structure of the ancestral bacterial sodium channel NaVAb, which is also blocked by LAs and AADs, revealed fenestrations connecting the lipid phase of the membrane to the central cavity of the pore. We cocrystallized lidocaine and flecainide with NavAb, which revealed strong drug-dependent electron density in the central cavity of the pore. Mutation of the contact residue T206 greatly reduced drug potency, confirming this site as the receptor for LAs and AADs. Strikingly, mutations of the fenestration cap residue F203 changed fenestration size and had graded effects on resting-state block by flecainide, lidocaine, and benzocaine, the potencies of which were altered from 51- to 2.6-fold in order of their molecular size. These results show that conserved fenestrations in the pores of sodium channels are crucial pharmacologically and determine the level of resting-state block by widely used drugs. Fine-tuning drug access through fenestrations provides an unexpected avenue for structure-based design of ion-channel-blocking drugs.
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Du Y, Tikhonov DB, Nomura Y, Dong K, Zhorov BS. Mutational analysis of state-dependent contacts in the pore module of eukaryotic sodium channels. Arch Biochem Biophys 2018; 652:59-70. [PMID: 29936083 DOI: 10.1016/j.abb.2018.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/06/2018] [Accepted: 06/20/2018] [Indexed: 02/04/2023]
Abstract
Voltage-gated sodium channels have residues that change or may change contacts upon gating. Contributions of individual contacts in stability of different states are incompletely understood. Pore-lining inner helices contain exceptionally conserved asparagines in positions i20. Here we explored how mutations in positions i20 and i29 affect electrophysiological properties of insect sodium channels. In repeat interfaces I/IV, III/II and IV/III, alanine substitutions caused positive activation shifts in positions i20 and i29, negative shifts of slow inactivation in positions i20 and positive shifts of slow inactivation in positions i29. The results support the hypothesis on open state inter-repeat H-bonding of residues i20 and i29. The shift magnitudes vary between interfaces, reflecting structural asymmetry of the channels. Mutations in positions i20 of repeats III and IV caused much longer recovery delay from the slow and fast inactivation than other mutations. In repeat IV, alanine substitution of tyrosine i30 rescued positive activation shift of mutation in position i29. Our data suggest that polar residues in positions i29 are involved in stabilization of both the open and slow-inactivated states. Transition between the states may involve switching of H-bonding partners of residues i29 from the conserved asparagines to currently unknown residues.
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Affiliation(s)
- Yuzhe Du
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, MI 48824, USA
| | - Denis B Tikhonov
- Sechenov Institute of Evolutionary Physiology & Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Yoshiko Nomura
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, MI 48824, USA
| | - Ke Dong
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, MI 48824, USA
| | - Boris S Zhorov
- Sechenov Institute of Evolutionary Physiology & Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia; Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
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Polyamine Modulation of Anticonvulsant Drug Response: A Potential Mechanism Contributing to Pharmacoresistance in Chronic Epilepsy. J Neurosci 2018; 38:5596-5605. [PMID: 29789377 DOI: 10.1523/jneurosci.0640-18.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/07/2018] [Accepted: 05/12/2018] [Indexed: 11/21/2022] Open
Abstract
Despite the development of numerous novel anticonvulsant drugs, ∼30% of epilepsy patients remain refractory to antiepileptic drugs (AEDs). Many established and novel AEDs reduce hyperexcitability via voltage- and use-dependent inhibition of voltage-gated Na+ channels. For the widely used anticonvulsant carbamazepine (CBZ), use-dependent block of Na+ channels is significantly reduced both in experimental and human epilepsy. However, the molecular underpinnings of this potential cellular mechanism for pharmacoresistance have remained enigmatic.Here, we describe the mechanism that leads to the emergence of CBZ-resistant Na+ channels. We focused on the endogenous polyamine system, which powerfully modulates Na+ channels in a use-dependent manner. We had shown previously that the intracellular polyamine spermine is reduced in chronic epilepsy, resulting in increased persistent Na+ currents. Because spermine and CBZ both bind use-dependently in spatial proximity within the Na+ channel pore, we hypothesized that spermine loss might also be related to diminished CBZ response. Using the pilocarpine model of refractory epilepsy in male rats and whole-cell patch-clamp recordings, we first replicated the reduction of use-dependent block by CBZ in chronically epileptic animals. We then substituted intracellular spermine via the patch pipette in different concentrations. Under these conditions, we found that exogenous spermine significantly rescues use-dependent block of Na+ channels by CBZ. These findings indicate that an unexpected modulatory mechanism, depletion of intracellular polyamines, leads both to increased persistent Na+ currents and to diminished CBZ sensitivity of Na+ channels. These findings could lead to novel strategies for overcoming pharmacoresistant epilepsy that target the polyamine system.SIGNIFICANCE STATEMENT Pharmacoresistant epilepsy affects ∼18 million people worldwide, and intense efforts have therefore been undertaken to uncover the underlying molecular and cellular mechanisms. One of the key known candidate mechanisms of pharmacoresistance has been a loss of use-dependent Na+ channel block by the anticonvulsant carbamazepine (CBZ), both in human and experimental epilepsies. Despite intense scrutiny, the molecular mechanisms underlying this phenomenon have not been elucidated. We now show that a loss of intracellular spermine in chronic epilepsy is a major causative factor leading to the development of CBZ-resistant Na+ currents. This finding can be exploited both for the screening of anticonvulsants in expression systems, and for novel strategies to overcome pharmacoresistance that target the polyamine system.
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Salvage SC, Chandrasekharan KH, Jeevaratnam K, Dulhunty AF, Thompson AJ, Jackson AP, Huang CL. Multiple targets for flecainide action: implications for cardiac arrhythmogenesis. Br J Pharmacol 2018; 175:1260-1278. [PMID: 28369767 PMCID: PMC5866987 DOI: 10.1111/bph.13807] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 03/27/2017] [Accepted: 03/29/2017] [Indexed: 12/19/2022] Open
Abstract
Flecainide suppresses cardiac tachyarrhythmias including paroxysmal atrial fibrillation, supraventricular tachycardia and arrhythmic long QT syndromes (LQTS), as well as the Ca2+ -mediated, catecholaminergic polymorphic ventricular tachycardia (CPVT). However, flecainide can also exert pro-arrhythmic effects most notably following myocardial infarction and when used to diagnose Brugada syndrome (BrS). These divergent actions result from its physiological and pharmacological actions at multiple, interacting levels of cellular organization. These were studied in murine genetic models with modified Nav channel or intracellular ryanodine receptor (RyR2)-Ca2+ channel function. Flecainide accesses its transmembrane Nav 1.5 channel binding site during activated, open, states producing a use-dependent antagonism. Closing either activation or inactivation gates traps flecainide within the pore. An early peak INa related to activation of Nav channels followed by rapid de-activation, drives action potential (AP) upstrokes and their propagation. This is diminished in pro-arrhythmic conditions reflecting loss of function of Nav 1.5 channels, such as BrS, accordingly exacerbated by flecainide challenge. Contrastingly, pro-arrhythmic effects attributed to prolonged AP recovery by abnormal late INaL following gain-of-function modifications of Nav 1.5 channels in LQTS3 are reduced by flecainide. Anti-arrhythmic effects of flecainide that reduce triggering in CPVT models mediated by sarcoplasmic reticular Ca2+ release could arise from its primary actions on Nav channels indirectly decreasing [Ca2+ ]i through a reduced [Na+ ]i and/or direct open-state RyR2-Ca2+ channel antagonism. The consequent [Ca2+ ]i alterations could also modify AP propagation velocity and therefore arrhythmic substrate through its actions on Nav 1.5 channel function. This is consistent with the paradoxical differences between flecainide actions upon Na+ currents, AP conduction and arrhythmogenesis under circumstances of normal and increased RyR2 function. LINKED ARTICLES This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc.
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Affiliation(s)
- Samantha C Salvage
- Department of BiochemistryUniversity of CambridgeCambridgeUK
- Physiological LaboratoryUniversity of CambridgeCambridgeUK
| | | | - Kamalan Jeevaratnam
- Faculty of Health and Medical SciencesUniversity of SurreyGuildfordUK
- School of MedicinePerdana University – Royal College of Surgeons IrelandSerdangSelangor Darul EhsanMalaysia
| | - Angela F Dulhunty
- Muscle Research Group, Eccles Institute of Neuroscience, John Curtin School of Medical ResearchAustralian National UniversityActonAustralia
| | | | | | - Christopher L‐H Huang
- Department of BiochemistryUniversity of CambridgeCambridgeUK
- Physiological LaboratoryUniversity of CambridgeCambridgeUK
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Yuan ML, Wang IJ. Sodium ion channel alkaloid resistance does not vary with toxicity in aposematic Dendrobates poison frogs: An examination of correlated trait evolution. PLoS One 2018. [PMID: 29534110 PMCID: PMC5849323 DOI: 10.1371/journal.pone.0194265] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spatial heterogeneity in the strength or agents of selection can lead to geographic variation in ecologically important phenotypes. Many dendrobatid frogs sequester alkaloid toxins from their diets and often exhibit fixed mutations at NaV1.4, a voltage-gated sodium ion channel associated with alkaloid toxin resistance. Yet previous studies have noted an absence of resistance mutations in individuals from several species known to sequester alkaloid toxins, suggesting possible intraspecific variation for alkaloid resistance in these species. Toxicity and alkaloid profiles vary substantially between populations in several poison frog species (genus Dendrobates) and are correlated with variation in a suite of related traits such as aposematic coloration. If resistance mutations are costly, due to alterations of channel gating properties, we expect that low toxicity populations will have reduced frequencies and potentially even the loss of resistance alleles. Here, we examine whether intraspecific variation in toxicity in three dendrobatid frogs is associated with intraspecific variation in alleles conferring toxin resistance. Specifically, we examine two species that display marked variation in toxicity throughout their native ranges (Dendrobates pumilio and D. granuliferus) and one species with reduced toxicity in its introduced range (D. auratus). However, we find no evidence for population-level variation in alkaloid resistance at NaV1.4. In fact, contrary to previous studies, we found that alkaloid resistance alleles were not absent in any populations of these species. All three species exhibit fixed alkaloid resistance mutations throughout their ranges, suggesting that these mutations are maintained even when alkaloid sequestration is substantially reduced.
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Affiliation(s)
- Michael L. Yuan
- Department of Environmental Science, Policy, and Management, College of Natural Resources, University of California, Berkeley, California, United States of America
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- * E-mail:
| | - Ian J. Wang
- Department of Environmental Science, Policy, and Management, College of Natural Resources, University of California, Berkeley, California, United States of America
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
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Distinct modulation of inactivation by a residue in the pore domain of voltage-gated Na + channels: mechanistic insights from recent crystal structures. Sci Rep 2018; 8:631. [PMID: 29330525 PMCID: PMC5766632 DOI: 10.1038/s41598-017-18919-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 12/18/2017] [Indexed: 12/19/2022] Open
Abstract
Inactivation of voltage-gated Na+ channels (VGSC) is essential for the regulation of cellular excitability. The molecular rearrangement underlying inactivation is thought to involve the intracellular linker between domains III and IV serving as inactivation lid, the receptor for the lid (domain III S4-S5 linker) and the pore-lining S6 segements. To better understand the role of the domain IV S6 segment in inactivation we performed a cysteine scanning mutagenesis of this region in rNav 1.4 channels and screened the constructs for perturbations in the voltage-dependence of steady state inactivation. This screen was performed in the background of wild-type channels and in channels carrying the mutation K1237E, which profoundly alters both permeation and gating-properties. Of all tested constructs the mutation I1581C was unique in that the mutation-induced gating changes were strongly influenced by the mutational background. This suggests that I1581 is involved in specific short-range interactions during inactivation. In recently published crystal structures VGSCs the respective amino acids homologous to I1581 appear to control a bend of the S6 segment which is critical to the gating process. Furthermore, I1581 may be involved in the transmission of the movement of the DIII voltage-sensor to the domain IV S6 segment.
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Abstract
Voltage-gated sodium (Na+) channels are expressed in virtually all electrically excitable tissues and are essential for muscle contraction and the conduction of impulses within the peripheral and central nervous systems. Genetic disorders that disrupt the function of these channels produce an array of Na+ channelopathies resulting in neuronal impairment, chronic pain, neuromuscular pathologies, and cardiac arrhythmias. Because of their importance to the conduction of electrical signals, Na+ channels are the target of a wide variety of local anesthetic, antiarrhythmic, anticonvulsant, and antidepressant drugs. The voltage-gated family of Na+ channels is composed of α-subunits that encode for the voltage sensor domains and the Na+-selective permeation pore. In vivo, Na+ channel α-subunits are associated with one or more accessory β-subunits (β1-β4) that regulate gating properties, trafficking, and cell-surface expression of the channels. The permeation pore of Na+ channels is divided in two parts: the outer mouth of the pore is the site of the ion selectivity filter, while the inner cytoplasmic pore serves as the channel activation gate. The cytoplasmic lining of the permeation pore is formed by the S6 segments that include highly conserved aromatic amino acids important for drug binding. These residues are believed to undergo voltage-dependent conformational changes that alter drug binding as the channels cycle through the closed, open, and inactivated states. The purpose of this chapter is to broadly review the mechanisms of Na+ channel gating and the models used to describe drug binding and Na+ channel inhibition.
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Affiliation(s)
- M E O'Leary
- Cooper Medical School of Rowan University, Camden, NJ, USA
| | - M Chahine
- CERVO Brain Research Center, Institut universitaire en santé mentale de Québec, Quebec City, QC, Canada.
- Department of Medicine, Université Laval, Quebec City, QC, Canada.
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Mangold KE, Brumback BD, Angsutararux P, Voelker TL, Zhu W, Kang PW, Moreno JD, Silva JR. Mechanisms and models of cardiac sodium channel inactivation. Channels (Austin) 2017; 11:517-533. [PMID: 28837385 PMCID: PMC5786193 DOI: 10.1080/19336950.2017.1369637] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 08/14/2017] [Accepted: 08/15/2017] [Indexed: 12/19/2022] Open
Abstract
Shortly after cardiac Na+ channels activate and initiate the action potential, inactivation ensues within milliseconds, attenuating the peak Na+ current, INa, and allowing the cell membrane to repolarize. A very limited number of Na+ channels that do not inactivate carry a persistent INa, or late INa. While late INa is only a small fraction of peak magnitude, it significantly prolongs ventricular action potential duration, which predisposes patients to arrhythmia. Here, we review our current understanding of inactivation mechanisms, their regulation, and how they have been modeled computationally. Based on this body of work, we conclude that inactivation and its connection to late INa would be best modeled with a "feet-on-the-door" approach where multiple channel components participate in determining inactivation and late INa. This model reflects experimental findings showing that perturbation of many channel locations can destabilize inactivation and cause pathological late INa.
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Affiliation(s)
- Kathryn E. Mangold
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Brittany D. Brumback
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Paweorn Angsutararux
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Taylor L. Voelker
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Wandi Zhu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Po Wei Kang
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jonathan D. Moreno
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jonathan R. Silva
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
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Single rat muscle Na + channel mutation confers batrachotoxin autoresistance found in poison-dart frog Phyllobates terribilis. Proc Natl Acad Sci U S A 2017; 114:10491-10496. [PMID: 28874544 DOI: 10.1073/pnas.1707873114] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Poison-dart Phyllobates terribilis frogs sequester lethal amounts of steroidal alkaloid batrachotoxin (BTX) in their skin as a defense mechanism against predators. BTX targets voltage-gated Na+ channels and enables them to open persistently. How BTX autoresistance arises in such frogs remains a mystery. The BTX receptor has been delineated along the Na+ channel inner cavity, which is formed jointly by four S6 transmembrane segments from domains D1 to D4. Within the P. terribilis muscle Na+ channel, five amino acid (AA) substitutions have been identified at D1/S6 and D4/S6. We therefore investigated the role of these naturally occurring substitutions in BTX autoresistance by introducing them into rat Nav1.4 muscle Na+ channel, both individually and in combination. Our results showed that combination mutants containing an N1584T substitution all conferred a complete BTX-resistant phenotype when expressed in mammalian HEK293t cells. The single N1584T mutant also retained its functional integrity and became exceptionally resistant to 5 µM BTX, aside from a small residual BTX effect. Single and combination mutants with the other four S6 residues (S429A, I433V, A445D, and V1583I) all remained highly BTX sensitive. These findings, along with diverse BTX phenotypes of N1584K/A/D/T mutant channels, led us to conclude that the conserved N1584 residue is indispensable for BTX actions, probably functioning as an integral part of the BTX receptor. Thus, complete BTX autoresistance found in P. terribilis muscle Na+ channels could emerge primarily from a single AA substitution (asparagine→threonine) via a single nucleotide mutation (AAC→ACC).
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Catterall WA. Forty Years of Sodium Channels: Structure, Function, Pharmacology, and Epilepsy. Neurochem Res 2017; 42:2495-2504. [PMID: 28589518 PMCID: PMC5693772 DOI: 10.1007/s11064-017-2314-9] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 05/19/2017] [Accepted: 05/26/2017] [Indexed: 11/24/2022]
Abstract
Voltage-gated sodium channels initiate action potentials in brain neurons. In the 1970s, much was known about the function of sodium channels from measurements of ionic currents using the voltage clamp method, but there was no information about the sodium channel molecules themselves. As a postdoctoral fellow and staff scientist at the National Institutes of Health, I developed neurotoxins as molecular probes of sodium channels in cultured neuroblastoma cells. During those years, Bruce Ransom and I crossed paths as members of the laboratories of Marshall Nirenberg and Philip Nelson and shared insights about sodium channels in neuroblastoma cells from my work and electrical excitability and synaptic transmission in cultured spinal cord neurons from Bruce's pioneering electrophysiological studies. When I established my laboratory at the University of Washington in 1977, my colleagues and I used those neurotoxins to identify the protein subunits of sodium channels, purify them, and reconstitute their ion conductance activity in pure form. Subsequent studies identified the molecular basis for the main functions of sodium channels-voltage-dependent activation, rapid and selective ion conductance, and fast inactivation. Bruce Ransom and I re-connected in the 1990s, as ski buddies at the Winter Conference on Brain Research and as faculty colleagues at the University of Washington when Bruce became our founding Chair of Neurology and provided visionary leadership of that department. In the past decade my work on sodium channels has evolved into structural biology. Molecular modeling and X-ray crystallographic studies have given new views of sodium channel function at atomic resolution. Sodium channels are also the molecular targets for genetic diseases, including Dravet Syndrome, an intractable pediatric epilepsy disorder with major co-morbidities of cognitive deficit, autistic-like behaviors, and premature death that is caused by loss-of-function mutations in the brain sodium channel NaV1.1. Our work on a mouse genetic model of this disease has shown that its multi-faceted pathophysiology and co-morbidities derive from selective loss of electrical excitability and action potential firing in GABAergic inhibitory neurons, which disinhibits neural circuits throughout the brain and leads directly to the epilepsy, premature death and complex co-morbidities of this disease. It has been rewarding for me to use our developing knowledge of sodium channels to help understand the pathophysiology and to suggest potential therapeutic approaches for this devastating childhood disease.
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Affiliation(s)
- William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA, 98195-7280, USA.
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48
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Mutagenesis of the NaChBac sodium channel discloses a functional role for a conserved S6 asparagine. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2017; 46:665-674. [PMID: 28825121 PMCID: PMC5599482 DOI: 10.1007/s00249-017-1246-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 07/21/2017] [Accepted: 07/29/2017] [Indexed: 12/11/2022]
Abstract
Asparagine is conserved in the S6 transmembrane segments of all voltage-gated sodium, calcium, and TRP channels identified to date. A broad spectrum of channelopathies including cardiac arrhythmias, epilepsy, muscle diseases, and pain disorders is associated with its mutation. To investigate its effects on sodium channel functional properties, we mutated the simple prokaryotic sodium channel NaChBac. Electrophysiological characterization of the N225D mutant reveals that this conservative substitution shifts the voltage-dependence of inactivation by 25 mV to more hyperpolarized potentials. The mutant also displays greater thermostability, as determined by synchrotron radiation circular dichroism spectroscopy studies of purified channels. Based on our analyses of high-resolution structures of NaChBac homologues, we suggest that the side-chain amine group of asparagine 225 forms one or more hydrogen bonds with different channel elements and that these interactions are important for normal channel function. The N225D mutation eliminates these hydrogen bonds and the structural consequences involve an enhanced channel inactivation.
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Yan Z, Zhou Q, Wang L, Wu J, Zhao Y, Huang G, Peng W, Shen H, Lei J, Yan N. Structure of the Na v1.4-β1 Complex from Electric Eel. Cell 2017; 170:470-482.e11. [PMID: 28735751 DOI: 10.1016/j.cell.2017.06.039] [Citation(s) in RCA: 222] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/26/2017] [Accepted: 06/23/2017] [Indexed: 02/07/2023]
Abstract
Voltage-gated sodium (Nav) channels initiate and propagate action potentials. Here, we present the cryo-EM structure of EeNav1.4, the Nav channel from electric eel, in complex with the β1 subunit at 4.0 Å resolution. The immunoglobulin domain of β1 docks onto the extracellular L5I and L6IV loops of EeNav1.4 via extensive polar interactions, and the single transmembrane helix interacts with the third voltage-sensing domain (VSDIII). The VSDs exhibit "up" conformations, while the intracellular gate of the pore domain is kept open by a digitonin-like molecule. Structural comparison with closed NavPaS shows that the outward transfer of gating charges is coupled to the iris-like pore domain dilation through intricate force transmissions involving multiple channel segments. The IFM fast inactivation motif on the III-IV linker is plugged into the corner enclosed by the outer S4-S5 and inner S6 segments in repeats III and IV, suggesting a potential allosteric blocking mechanism for fast inactivation.
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Affiliation(s)
- Zhen Yan
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, China; Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Qiang Zhou
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, China; Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Lin Wang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, China; Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jianping Wu
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, China; Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yanyu Zhao
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Gaoxingyu Huang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, China; Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Wei Peng
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Huaizong Shen
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jianlin Lei
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China; Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Nieng Yan
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing, China; Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.
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50
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James TF, Nenov MN, Tapia CM, Lecchi M, Koshy S, Green TA, Laezza F. Consequences of acute Na v1.1 exposure to deltamethrin. Neurotoxicology 2017; 60:150-160. [PMID: 28007400 PMCID: PMC5447465 DOI: 10.1016/j.neuro.2016.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 12/02/2016] [Accepted: 12/14/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND Pyrethroid insecticides are the most popular class of insecticides in the world, despite their near-ubiquity, their effects of delaying the onset of inactivation of voltage-gated sodium (Nav) channels have not been well-evaluated in all the mammalian Nav isoforms. OBJECTIVE Here we compare the well-studied Nav1.6 isoforms to the less-understood Nav1.1 in their responses to acute deltamethrin exposure. METHODS We used patch-clamp electrophysiology to record sodium currents encoded by either Nav1.1 or Nav1.6 channels stably expressed in HEK293 cells. Protocols evaluating both resting and use-dependent modification were employed. RESULTS We found that exposure of both isoforms to 10μM deltamethrin significantly potentiated persistent and tail current densities without affecting peak transient current densities, and only Nav1.1 maintained these significant effects at 1μM deltamethrin. Window currents increased for both as well, and while only Nav1.6 displayed changes in activation slope and V1/2 of steady-state inactivation for peak currents, V1/2 of persistent current activation was hyperpolarized of ∼10mV by deltamethrin in Nav1.1 cells. Evaluating use-dependence, we found that deltamethrin again potentiated persistent and tail current densities in both isoforms, but only Nav1.6 demonstrated use-dependent enhancement, indicating the primary deltamethrin-induced effects on Nav1.1 channels are not use-dependent. CONCLUSION Collectively, these data provide evidence that Nav1.1 is indeed vulnerable to deltamethrin modification at lower concentrations than Nav1.6, and this effect is primarily mediated during the resting state. GENERAL SIGNIFICANCE These findings identify Nav1.1 as a novel target of pyrethroid exposure, which has major implications for the etiology of neuropsychiatric disorders associated with loss of Nav1.1-expressing inhibitory neurons.
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Affiliation(s)
- T F James
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, USA; Neuroscience Graduate Program, University of Texas Medical Branch, USA
| | - Miroslav N Nenov
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, USA
| | - Cynthia M Tapia
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, USA
| | - Marzia Lecchi
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Italy
| | - Shyny Koshy
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, USA; Center for Addiction Research, University of Texas Medical Branch, USA
| | - Thomas A Green
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, USA; Center for Addiction Research, University of Texas Medical Branch, USA
| | - Fernanda Laezza
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, USA; Mitchell Center for Neurodegenerative Diseases, USA; Center for Environmental Toxicology, University of Texas Medical Branch, USA; Center for Addiction Research, University of Texas Medical Branch, USA.
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