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Moreira-Junior L, Leal-Cardoso JH, Cassola AC, Carvalho-de-Souza JL. Eugenol and lidocaine inhibit voltage-gated Na + channels from dorsal root ganglion neurons with different mechanisms. Front Pharmacol 2024; 15:1354737. [PMID: 38989141 PMCID: PMC11234063 DOI: 10.3389/fphar.2024.1354737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 04/08/2024] [Indexed: 07/12/2024] Open
Abstract
Eugenol (EUG) is a bioactive monoterpenoid used as an analgesic, preservative, and flavoring agent. Our new data show EUG as a voltage-gated Na+ channel (VGSC) inhibitor, comparable but not identical to lidocaine (LID). EUG inhibits both total and only TTX-R voltage-activated Na+ currents (INa) recorded from VGSCs naturally expressed on dorsal root ganglion sensory neurons in rats. Inhibition is quick, fully reversible, and dose-dependent. Our biophysical and pharmacological analyses showed that EUG and LID inhibit VGSCs with different mechanisms. EUG inhibits VGSCs with a dose-response relationship characterized by a Hill coefficient of 2, while this parameter for the inhibition by LID is 1. Furthermore, in a different way from LID, EUG modified the voltage dependence of both the VGSC activation and inactivation processes and the recovery from fast inactivated states and the entry to slow inactivated states. In addition, we suggest that EUG, but not LID, interacts with VGSC pre-open-closed states, according to our data.
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Affiliation(s)
- Luiz Moreira-Junior
- Department of Anesthesiology, University of Arizona, Tucson, AZ, United States
| | | | - Antonio Carlos Cassola
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, São Paulo, Brazil
| | - Joao Luis Carvalho-de-Souza
- Department of Anesthesiology, University of Arizona, Tucson, AZ, United States
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, São Paulo, Brazil
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2
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Tibery DV, Nunes JAA, da Mata DO, Menezes LFS, de Souza ACB, Fernandes-Pedrosa MDF, Treptow W, Schwartz EF. Unveiling Tst3, a Multi-Target Gating Modifier Scorpion α Toxin from Tityus stigmurus Venom of Northeast Brazil: Evaluation and Comparison with Well-Studied Ts3 Toxin of Tityus serrulatus. Toxins (Basel) 2024; 16:257. [PMID: 38922152 PMCID: PMC11209618 DOI: 10.3390/toxins16060257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/27/2024] [Accepted: 05/30/2024] [Indexed: 06/27/2024] Open
Abstract
Studies on the interaction sites of peptide toxins and ion channels typically involve site-directed mutations in toxins. However, natural mutant toxins exist among them, offering insights into how the evolutionary process has conserved crucial sequences for activities and molecular target selection. In this study, we present a comparative investigation using electrophysiological approaches and computational analysis between two alpha toxins from evolutionarily close scorpion species of the genus Tityus, namely, Tst3 and Ts3 from T. stigmurus and T. serrulatus, respectively. These toxins exhibit three natural substitutions near the C-terminal region, which is directly involved in the interaction between alpha toxins and Nav channels. Additionally, we characterized the activity of the Tst3 toxin on Nav1.1-Nav1.7 channels. The three natural changes between the toxins did not alter sensitivity to Nav1.4, maintaining similar intensities regarding their ability to alter opening probabilities, delay fast inactivation, and induce persistent currents. Computational analysis demonstrated a preference for the down conformation of VSD4 and a shift in the conformational equilibrium towards this state. This illustrates that the sequence of these toxins retained the necessary information, even with alterations in the interaction site region. Through electrophysiological and computational analyses, screening of the Tst3 toxin on sodium isoform revealed its classification as a classic α-NaTx with a broad spectrum of activity. It effectively delays fast inactivation across all tested isoforms. Structural analysis of molecular energetics at the interface of the VSD4-Tst3 complex further confirmed this effect.
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Affiliation(s)
- Diogo Vieira Tibery
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília (UnB), Brasília 70910-900, Distrito Federal, Brazil; (D.V.T.); (D.O.d.M.); (L.F.S.M.); (A.C.B.d.S.)
| | - João Antonio Alves Nunes
- Laboratório de Biologia Teórica e Computacional (LBTC), Departamento de Biologia Celular, Universidade de Brasília (UnB), Brasília 70910-900, Distrito Federal, Brazil; (J.A.A.N.); (W.T.)
| | - Daniel Oliveira da Mata
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília (UnB), Brasília 70910-900, Distrito Federal, Brazil; (D.V.T.); (D.O.d.M.); (L.F.S.M.); (A.C.B.d.S.)
| | - Luis Felipe Santos Menezes
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília (UnB), Brasília 70910-900, Distrito Federal, Brazil; (D.V.T.); (D.O.d.M.); (L.F.S.M.); (A.C.B.d.S.)
| | - Adolfo Carlos Barros de Souza
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília (UnB), Brasília 70910-900, Distrito Federal, Brazil; (D.V.T.); (D.O.d.M.); (L.F.S.M.); (A.C.B.d.S.)
| | - Matheus de Freitas Fernandes-Pedrosa
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Departamento de Farmácia, Universidade Federal do Rio Grande do Norte (UFRN), Natal 59012-570, Rio Grande do Norte, Brazil;
| | - Werner Treptow
- Laboratório de Biologia Teórica e Computacional (LBTC), Departamento de Biologia Celular, Universidade de Brasília (UnB), Brasília 70910-900, Distrito Federal, Brazil; (J.A.A.N.); (W.T.)
| | - Elisabeth Ferroni Schwartz
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília (UnB), Brasília 70910-900, Distrito Federal, Brazil; (D.V.T.); (D.O.d.M.); (L.F.S.M.); (A.C.B.d.S.)
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3
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Schott K, Usher SG, Serra O, Carnevale V, Pless SA, Chua HC. Unplugging lateral fenestrations of NALCN reveals a hidden drug binding site within the pore region. Proc Natl Acad Sci U S A 2024; 121:e2401591121. [PMID: 38787877 PMCID: PMC11145269 DOI: 10.1073/pnas.2401591121] [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: 01/23/2024] [Accepted: 04/09/2024] [Indexed: 05/26/2024] Open
Abstract
The sodium (Na+) leak channel (NALCN) is a member of the four-domain voltage-gated cation channel family that includes the prototypical voltage-gated sodium and calcium channels (NaVs and CaVs, respectively). Unlike NaVs and CaVs, which have four lateral fenestrations that serve as routes for lipophilic compounds to enter the central cavity to modulate channel function, NALCN has bulky residues (W311, L588, M1145, and Y1436) that block these openings. Structural data suggest that occluded fenestrations underlie the pharmacological resistance of NALCN, but functional evidence is lacking. To test this hypothesis, we unplugged the fenestrations of NALCN by substituting the four aforementioned residues with alanine (AAAA) and compared the effects of NaV, CaV, and NALCN blockers on both wild-type (WT) and AAAA channels. Most compounds behaved in a similar manner on both channels, but phenytoin and 2-aminoethoxydiphenyl borate (2-APB) elicited additional, distinct responses on AAAA channels. Further experiments using single alanine mutants revealed that phenytoin and 2-APB enter the inner cavity through distinct fenestrations, implying structural specificity to their modes of access. Using a combination of computational and functional approaches, we identified amino acid residues critical for 2-APB activity, supporting the existence of drug binding site(s) within the pore region. Intrigued by the activity of 2-APB and its analogues, we tested compounds containing the diphenylmethane/amine moiety on WT channels. We identified clinically used drugs that exhibited diverse activity, thus expanding the pharmacological toolbox for NALCN. While the low potencies of active compounds reiterate the pharmacological resistance of NALCN, our findings lay the foundation for rational drug design to develop NALCN modulators with refined properties.
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Affiliation(s)
- Katharina Schott
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
| | - Samuel George Usher
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
| | - Oscar Serra
- Department of Biology, Temple University, Philadelphia, PA19122
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA19122
- Institute of Computational Molecular Science, Temple University, Philadelphia, PA19122
| | - Vincenzo Carnevale
- Department of Biology, Temple University, Philadelphia, PA19122
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA19122
- Institute of Computational Molecular Science, Temple University, Philadelphia, PA19122
| | - Stephan Alexander Pless
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
| | - Han Chow Chua
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
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4
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Chen H, Xia Z, Dong J, Huang B, Zhang J, Zhou F, Yan R, Shi Y, Gong J, Jiang J, Huang Z, Jiang D. Structural mechanism of voltage-gated sodium channel slow inactivation. Nat Commun 2024; 15:3691. [PMID: 38693179 PMCID: PMC11063143 DOI: 10.1038/s41467-024-48125-3] [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: 07/07/2023] [Accepted: 04/17/2024] [Indexed: 05/03/2024] Open
Abstract
Voltage-gated sodium (NaV) channels mediate a plethora of electrical activities. NaV channels govern cellular excitability in response to depolarizing stimuli. Inactivation is an intrinsic property of NaV channels that regulates cellular excitability by controlling the channel availability. The fast inactivation, mediated by the Ile-Phe-Met (IFM) motif and the N-terminal helix (N-helix), has been well-characterized. However, the molecular mechanism underlying NaV channel slow inactivation remains elusive. Here, we demonstrate that the removal of the N-helix of NaVEh (NaVEhΔN) results in a slow-inactivated channel, and present cryo-EM structure of NaVEhΔN in a potential slow-inactivated state. The structure features a closed activation gate and a dilated selectivity filter (SF), indicating that the upper SF and the inner gate could serve as a gate for slow inactivation. In comparison to the NaVEh structure, NaVEhΔN undergoes marked conformational shifts on the intracellular side. Together, our results provide important mechanistic insights into NaV channel slow inactivation.
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Affiliation(s)
- Huiwen Chen
- Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Road, Xiangfang District, Harbin, 150030, China
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Zhanyi Xia
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Jie Dong
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Bo Huang
- Beijing StoneWise Technology Co Ltd., 15 Haidian street, Haidian district, Beijing, China
| | - Jiangtao Zhang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Feng Zhou
- Beijing StoneWise Technology Co Ltd., 15 Haidian street, Haidian district, Beijing, China
| | - Rui Yan
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yiqiang Shi
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Jianke Gong
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Juquan Jiang
- Department of Microbiology and Biotechnology, College of Life Sciences, Northeast Agricultural University, No. 600 Changjiang Road, Xiangfang District, Harbin, 150030, China.
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China.
| | - Daohua Jiang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China.
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5
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Tonggu L, Wisedchaisri G, Gamal El-Din TM, Lenaeus MJ, Logan MM, Toma T, Du Bois J, Zheng N, Catterall WA. Dual receptor-sites reveal the structural basis for hyperactivation of sodium channels by poison-dart toxin batrachotoxin. Nat Commun 2024; 15:2306. [PMID: 38485923 PMCID: PMC10940626 DOI: 10.1038/s41467-024-45958-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 02/08/2024] [Indexed: 03/18/2024] Open
Abstract
The poison dart toxin batrachotoxin is exceptional for its high potency and toxicity, and for its multifaceted modification of the function of voltage-gated sodium channels. By using cryogenic electron microscopy, we identify two homologous, but nonidentical receptor sites that simultaneously bind two molecules of toxin, one at the interface between Domains I and IV, and the other at the interface between Domains III and IV of the cardiac sodium channel. Together, these two bound toxin molecules stabilize α/π helical conformation in the S6 segments that gate the pore, and one of the bound BTX-B molecules interacts with the crucial Lys1421 residue that is essential for sodium conductance and selectivity via an apparent water-bridged hydrogen bond. Overall, our structure provides insight into batrachotoxin's potency, efficacy, and multifaceted functional effects on voltage-gated sodium channels via a dual receptor site mechanism.
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Affiliation(s)
- Lige Tonggu
- Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | | | | | - Michael J Lenaeus
- Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Matthew M Logan
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
- Vividion Therapeutics, Inc., 5820 Nancy Ridge Dr., San Diego, CA, 92121, USA
| | - Tatsuya Toma
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
- PRISM BioLab Co., Ltd., 2-26-1 Muraokahigashi, Fujisawa-shi, Kanagawa, 251-8555, Japan
| | - Justin Du Bois
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA.
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA.
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA.
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6
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Paasche A, Wiedmann F, Kraft M, Seibertz F, Herlt V, Blochberger PL, Jávorszky N, Beck M, Weirauch L, Seeger T, Blank A, Haefeli WE, Arif R, Meyer AL, Warnecke G, Karck M, Voigt N, Frey N, Schmidt C. Acute antiarrhythmic effects of SGLT2 inhibitors-dapagliflozin lowers the excitability of atrial cardiomyocytes. Basic Res Cardiol 2024; 119:93-112. [PMID: 38170280 PMCID: PMC10837223 DOI: 10.1007/s00395-023-01022-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 11/08/2023] [Accepted: 11/24/2023] [Indexed: 01/05/2024]
Abstract
In recent years, SGLT2 inhibitors have become an integral part of heart failure therapy, and several mechanisms contributing to cardiorenal protection have been identified. In this study, we place special emphasis on the atria and investigate acute electrophysiological effects of dapagliflozin to assess the antiarrhythmic potential of SGLT2 inhibitors. Direct electrophysiological effects of dapagliflozin were investigated in patch clamp experiments on isolated atrial cardiomyocytes. Acute treatment with elevated-dose dapagliflozin caused a significant reduction of the action potential inducibility, the amplitude and maximum upstroke velocity. The inhibitory effects were reproduced in human induced pluripotent stem cell-derived cardiomyocytes, and were more pronounced in atrial compared to ventricular cells. Hypothesizing that dapagliflozin directly affects the depolarization phase of atrial action potentials, we examined fast inward sodium currents in human atrial cardiomyocytes and found a significant decrease of peak sodium current densities by dapagliflozin, accompanied by a moderate inhibition of the transient outward potassium current. Translating these findings into a porcine large animal model, acute elevated-dose dapagliflozin treatment caused an atrial-dominant reduction of myocardial conduction velocity in vivo. This could be utilized for both, acute cardioversion of paroxysmal atrial fibrillation episodes and rhythm control of persistent atrial fibrillation. In this study, we show that dapagliflozin alters the excitability of atrial cardiomyocytes by direct inhibition of peak sodium currents. In vivo, dapagliflozin exerts antiarrhythmic effects, revealing a potential new additional role of SGLT2 inhibitors in the treatment of atrial arrhythmias.
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Affiliation(s)
- Amelie Paasche
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Felix Wiedmann
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Manuel Kraft
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Fitzwilliam Seibertz
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Robert Koch Strasse 42a, 37075, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research) Partner Site Göttingen, Robert Koch Strasse 42a, 37075, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Robert Koch Strasse 40, 37075, Göttingen, Germany
| | - Valerie Herlt
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Pablo L Blochberger
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Natasa Jávorszky
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Moritz Beck
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Leo Weirauch
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Timon Seeger
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
| | - Antje Blank
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Walter E Haefeli
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Rawa Arif
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Anna L Meyer
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Gregor Warnecke
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Matthias Karck
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Niels Voigt
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Robert Koch Strasse 42a, 37075, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research) Partner Site Göttingen, Robert Koch Strasse 42a, 37075, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Robert Koch Strasse 40, 37075, Göttingen, Germany
| | - Norbert Frey
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Constanze Schmidt
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany.
- HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
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Schott K, Usher SG, Serra O, Carnevale V, Pless SA, Chua HC. Unplugging lateral fenestrations of NALCN reveals a hidden drug binding site within the pore module. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.12.536537. [PMID: 38328210 PMCID: PMC10849497 DOI: 10.1101/2023.04.12.536537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The sodium (Na + ) leak channel (NALCN) is a member of the four-domain voltage-gated cation channel family that includes the prototypical voltage-gated sodium and calcium channels (Na V s and Ca V s, respectively). Unlike Na V s and Ca V s, which have four lateral fenestrations that serve as routes for lipophilic compounds to enter the central cavity to modulate channel function, NALCN has bulky residues (W311, L588, M1145 and Y1436) that block these openings. Structural data suggest that oc-cluded lateral fenestrations underlie the pharmacological resistance of NALCN to lipophilic compounds, but functional evidence is lacking. To test this hypothesis, we unplugged the fenestrations of NALCN by substituting the four aforementioned resi-dues with alanine (AAAA) and compared the effects of Na V , Ca V and NALCN block-ers on both wild-type (WT) and AAAA channels. Most compounds behaved in a simi-lar manner on both channels, but phenytoin and 2-aminoethoxydiphenyl borate (2-APB) elicited additional, distinct responses on AAAA channels. Further experiments using single alanine mutants revealed that phenytoin and 2-APB enter the inner cav-ity through distinct fenestrations, implying structural specificity to their modes of ac-cess. Using a combination of computational and functional approaches, we identified amino acid residues critical for 2-APB activity, supporting the existence of drug bind-ing site(s) within the pore region. Intrigued by the activity of 2-APB and its ana-logues, we tested additional compounds containing the diphenylmethane/amine moiety on WT channels. We identified compounds from existing clinically used drugs that exhibited diverse activity, thus expanding the pharmacological toolbox for NALCN. While the low potencies of active compounds reiterate the resistance of NALCN to pharmacological targeting, our findings lay the foundation for rational drug design to develop NALCN modulators with refined properties. Significance statement The sodium leak channel (NALCN) is essential for survival: mutations cause life-threatening developmental disorders in humans. However, no treatment is currently available due to the resistance of NALCN to pharmacological targeting. One likely reason is that the lateral fenestrations, a common route for clinically used drugs to enter and block related ion channels, are occluded in NALCN. Using a combination of computational and functional approaches, we unplugged the fenestrations of NALCN which led us to the first molecularly defined drug binding site within the pore region. Besides that, we also identified additional NALCN modulators from existing clinically used therapeutics, thus expanding the pharmacological toolbox for this leak channel.
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8
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Finkelstein DS, Du Bois J. Trifunctional Saxitoxin Conjugates for Covalent Labeling of Voltage-Gated Sodium Channels. Chembiochem 2023; 24:e202300493. [PMID: 37746898 PMCID: PMC10863845 DOI: 10.1002/cbic.202300493] [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: 07/04/2023] [Revised: 08/24/2023] [Indexed: 09/26/2023]
Abstract
Voltage-gated sodium ion channels (NaV s) are integral membrane protein complexes responsible for electrical signal conduction in excitable cells. Methods that enable selective labeling of NaV s hold potential value for understanding how channel regulation and post-translational modification are influenced during development and in response to diseases and disorders of the nervous system. We have developed chemical reagents patterned after (+)-saxitoxin (STX) - a potent and reversible inhibitor of multiple NaV isoforms - and affixed with a reactive electrophile and either a biotin cofactor, fluorophore, or 'click' functional group for labeling wild-type channels. Our studies reveal enigmatic structural effects of the probes on the potency and efficiency of covalent protein modification. Among the compounds analyzed, a STX-maleimide-coumarin derivative is most effective at irreversibly blocking Na+ conductance when applied to recombinant NaV s and endogenous channels expressed in hippocampal neurons. Mechanistic analysis supports the conclusion that high-affinity toxin binding is a prerequisite for covalent protein modification. Results from these studies are guiding the development of next-generation tool compounds for selective modification of NaV s expressed in the plasma membranes of cells.
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Affiliation(s)
- Darren S Finkelstein
- Department of Chemistry, Stanford University, 337 Campus Dr., Stanford, CA 94305, USA
- Present address: Pliant Therapeutics, 260 Littlefield Avenue, South San Francisco, CA 94080, USA
| | - J Du Bois
- Department of Chemistry, Stanford University, 337 Campus Dr., Stanford, CA 94305, USA
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9
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Hu Y, Cang J, Hiraishi K, Fujita T, Inoue R. The Role of TRPM4 in Cardiac Electrophysiology and Arrhythmogenesis. Int J Mol Sci 2023; 24:11798. [PMID: 37511555 PMCID: PMC10380800 DOI: 10.3390/ijms241411798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/20/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
The transient receptor potential melastatin 4 (TRPM4) channel is a non-selective cation channel that activates in response to increased intracellular Ca2+ levels but does not allow Ca2+ to pass through directly. It plays a crucial role in regulating diverse cellular functions associated with intracellular Ca2+ homeostasis/dynamics. TRPM4 is widely expressed in the heart and is involved in various physiological and pathological processes therein. Specifically, it has a significant impact on the electrical activity of cardiomyocytes by depolarizing the membrane, presumably via Na+ loading. The TRPM4 channel likely contributes to the development of cardiac arrhythmias associated with specific genetic backgrounds and cardiac remodeling. This short review aims to overview what is known so far about the TRPM4 channel in cardiac electrophysiology and arrhythmogenesis, highlighting its potential as a novel therapeutic target to effectively prevent and treat cardiac arrhythmias.
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Affiliation(s)
- Yaopeng Hu
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
| | - Jiehui Cang
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
| | - Keizo Hiraishi
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
| | - Takayuki Fujita
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
| | - Ryuji Inoue
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
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10
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Sanchez-Sandoval AL, Hernández-Plata E, Gomora JC. Voltage-gated sodium channels: from roles and mechanisms in the metastatic cell behavior to clinical potential as therapeutic targets. Front Pharmacol 2023; 14:1206136. [PMID: 37456756 PMCID: PMC10348687 DOI: 10.3389/fphar.2023.1206136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 06/21/2023] [Indexed: 07/18/2023] Open
Abstract
During the second half of the last century, the prevalent knowledge recognized the voltage-gated sodium channels (VGSCs) as the proteins responsible for the generation and propagation of action potentials in excitable cells. However, over the last 25 years, new non-canonical roles of VGSCs in cancer hallmarks have been uncovered. Their dysregulated expression and activity have been associated with aggressive features and cancer progression towards metastatic stages, suggesting the potential use of VGSCs as cancer markers and prognostic factors. Recent work has elicited essential information about the signalling pathways modulated by these channels: coupling membrane activity to transcriptional regulation pathways, intracellular and extracellular pH regulation, invadopodia maturation, and proteolytic activity. In a promising scenario, the inhibition of VGSCs with FDA-approved drugs as well as with new synthetic compounds, reduces cancer cell invasion in vitro and cancer progression in vivo. The purpose of this review is to present an update regarding recent advances and ongoing efforts to have a better understanding of molecular and cellular mechanisms on the involvement of both pore-forming α and auxiliary β subunits of VGSCs in the metastatic processes, with the aim at proposing VGSCs as new oncological markers and targets for anticancer treatments.
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Affiliation(s)
- Ana Laura Sanchez-Sandoval
- Departamento de Neuropatología Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Medicina Genómica, Hospital General de México “Dr Eduardo Liceaga”, Mexico City, Mexico
| | - Everardo Hernández-Plata
- Consejo Nacional de Humanidades, Ciencias y Tecnologías and Instituto Nacional de Medicina Genómica, Mexico City, Mexico
| | - Juan Carlos Gomora
- Departamento de Neuropatología Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
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11
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Niklas B, Rydzewski J, Lapied B, Nowak W. Toward Overcoming Pyrethroid Resistance in Mosquito Control: The Role of Sodium Channel Blocker Insecticides. Int J Mol Sci 2023; 24:10334. [PMID: 37373481 DOI: 10.3390/ijms241210334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/14/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Diseases spread by mosquitoes lead to the death of 700,000 people each year. The main way to reduce transmission is vector control by biting prevention with chemicals. However, the most commonly used insecticides lose efficacy due to the growing resistance. Voltage-gated sodium channels (VGSCs), membrane proteins responsible for the depolarizing phase of an action potential, are targeted by a broad range of neurotoxins, including pyrethroids and sodium channel blocker insecticides (SCBIs). Reduced sensitivity of the target protein due to the point mutations threatened malaria control with pyrethroids. Although SCBIs-indoxacarb (a pre-insecticide bioactivated to DCJW in insects) and metaflumizone-are used in agriculture only, they emerge as promising candidates in mosquito control. Therefore, a thorough understanding of molecular mechanisms of SCBIs action is urgently needed to break the resistance and stop disease transmission. In this study, by performing an extensive combination of equilibrium and enhanced sampling molecular dynamics simulations (3.2 μs in total), we found the DIII-DIV fenestration to be the most probable entry route of DCJW to the central cavity of mosquito VGSC. Our study revealed that F1852 is crucial in limiting SCBI access to their binding site. Our results explain the role of the F1852T mutation found in resistant insects and the increased toxicity of DCJW compared to its bulkier parent compound, indoxacarb. We also delineated residues that contribute to both SCBIs and non-ester pyrethroid etofenprox binding and thus could be involved in the target site cross-resistance.
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Affiliation(s)
- Beata Niklas
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun, Poland
| | - Jakub Rydzewski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun, Poland
| | - Bruno Lapied
- University Angers, INRAE, SIFCIR, SFR QUASAV, F-49045 Angers, France
| | - Wieslaw Nowak
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun, Poland
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12
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Ishikawa T, Aoki H. Letter regarding "SCN9A variant in a family of mixed breed dogs with congenital insensitivity to pain"-Navigating the pathogenicity of candidate gene mutations: Spotlight on paralog Nav genes. J Vet Intern Med 2023; 37:791-792. [PMID: 37083183 DOI: 10.1111/jvim.16708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 03/31/2023] [Indexed: 04/22/2023] Open
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13
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Li K, Jiang Y, Zeng Y, Zhou Y. Advances in Ion Channel, Non-Desmosomal Variants and Autophagic Mechanisms Implicated in Arrhythmogenic Cardiomyopathy. Curr Issues Mol Biol 2023; 45:2186-2200. [PMID: 36975511 PMCID: PMC10047275 DOI: 10.3390/cimb45030141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023] Open
Abstract
Arrhythmogenic cardiomyopathy (ACM) is a heterogeneous disorder characterized by the replacement of cardiac myocytes with fibro-fatty tissues, leading to abnormal excitation-contraction (EC) coupling and a range of malignant events, such as ventricular tachycardia (VT), sudden cardiac death/arrest (SCD/A) and heart failure (HF). The concept of ACM has recently been ex-tended to include right ventricular cardiomyopathy (ARVC), left ventricular cardiomyopathy (ALVC) and biventricular cardiomyopathy. ARVC is generally seen as the most common type of ACM. The pathogenesis of ACM involves mutation variants in desmosomal or non-desmosomal gene loci, as well as various external factors, such as intense exercise, stress and infections. Ion channel alterations, autophagy and non-desmosomal variants are also important components in the development of ACM. As clinical practice enters the era of precision therapy, it is important to review recent studies on these topics to better diagnose and treat the molecular phase of ACM.
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Affiliation(s)
- Kexin Li
- Department of Cardiology, Dushu Lake Hospital Affiliated to Soochow University, Suzhou 215000, China
- Institution for Hypertension of Soochow University, Suzhou 215000, China
| | - Yufeng Jiang
- Department of Cardiology, Dushu Lake Hospital Affiliated to Soochow University, Suzhou 215000, China
- Institution for Hypertension of Soochow University, Suzhou 215000, China
| | - Yiyao Zeng
- Department of Cardiology, Dushu Lake Hospital Affiliated to Soochow University, Suzhou 215000, China
- Institution for Hypertension of Soochow University, Suzhou 215000, China
| | - Yafeng Zhou
- Department of Cardiology, Dushu Lake Hospital Affiliated to Soochow University, Suzhou 215000, China
- Institution for Hypertension of Soochow University, Suzhou 215000, China
- Correspondence: ; Tel.: +86-512-65955026
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14
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Inhibition of Voltage-Gated Na + Currents Exerted by KB-R7943 (2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl]isothiourea), an Inhibitor of Na +-Ca 2+ Exchanging Process. Int J Mol Sci 2023; 24:ijms24021805. [PMID: 36675319 PMCID: PMC9864174 DOI: 10.3390/ijms24021805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/21/2022] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
KB-R7943, an isothiourea derivative, has been recognized as an inhibitor in the reverse mode of the Na+-Ca2+ exchanging process. This compound was demonstrated to prevent intracellular Na+-dependent Ca2+ uptake in intact cells; however, it is much less effective at preventing extracellular Na+-dependent Ca2+ efflux. Therefore, whether or how this compound may produce any perturbations on other types of ionic currents, particularly on voltage-gated Na+ current (INa), needs to be further studied. In this study, the whole-cell current recordings demonstrated that upon abrupt depolarization in pituitary GH3 cells, the exposure to KB-R7943 concentration-dependently depressed the transient (INa(T)) or late component (INa(L)) of INa with an IC50 value of 11 or 0.9 μM, respectively. Likewise, the dissociation constant for the KB-R7943-mediated block of INa on the basis of a minimum reaction scheme was estimated to be 0.97 μM. The presence of benzamil or amiloride could suppress the INa(L) magnitude. The instantaneous window Na+ current (INa(W)) activated by abrupt ascending ramp voltage (Vramp) was suppressed by adding KB-R7943; however, subsequent addition of deltamethrin or tefluthrin (Tef) effectively reversed KB-R7943-inhibted INa(W). With prolonged duration of depolarizing pulses, the INa(L) amplitude became exponentially decreased; moreover, KB-R7943 diminished INa(L) magnitude. The resurgent Na+ current (INa(R)) evoked by a repolarizing Vramp was also suppressed by adding this compound; moreover, subsequent addition of ranolazine or Tef further diminished or reversed, respectively, its reduction in INa(R) magnitude. The persistent Na+ current (INa(P)) activated by sinusoidal voltage waveform became enhanced by Tef; however, subsequent application of KB-R7943 counteracted Tef-stimulated INa(P). The docking prediction reflected that there seem to be molecular interactions of this molecule with the hNaV1.2 or hNaV1.7 channels. Collectively, this study highlights evidence showing that KB-R7943 has the propensity to perturb the magnitude and gating kinetics of INa (e.g., INa(T), INa(L), INa(W), INa(R), and INa(P)) and that the NaV channels appear to be important targets for the in vivo actions of KB-R7943 or other relevant compounds.
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Gu Y, Wang J, Li M, Zhong F, Xiang J, Xu Z. Inhibitory Effects of Nobiletin on Voltage-Gated Na + Channel in Rat Ventricular Myocytes Based on Electrophysiological Analysis and Molecular Docking Method. Int J Mol Sci 2022; 23:ijms232315175. [PMID: 36499507 PMCID: PMC9736168 DOI: 10.3390/ijms232315175] [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: 11/03/2022] [Revised: 11/27/2022] [Accepted: 11/30/2022] [Indexed: 12/07/2022] Open
Abstract
Nobiletin (NOB) has attracted much attention owing to its outstanding bioactivities. This study aimed to investigate its anti-arrhythmic effect through electrophysiological and molecular docking studies. We assessed the anti-arrhythmic effects of NOB using aconitine-induced ventricular arrhythmia in a rat model and the electrophysiological effects of NOB on rat cardiomyocytes utilizing whole-cell patch-clamp techniques. Moreover, we investigated the binding characters of NOB with rNav1.5, rNav1.5/QQQ, and hNaV1.5 via docking analysis, comparing them with amiodarone and aconitine. NOB pretreatment delayed susceptibility to ventricular premature and ventricular tachycardia and decreased the incidence of fatal ventricular fibrillation. Whole-cell patch-clamp assays demonstrated that the peak current density of the voltage-gated Na+ channel current was reversibly reduced by NOB in a concentration-dependent manner. The steady-state activation and recovery curves were shifted in the positive direction along the voltage axis, and the steady-state inactivation curve was shifted in the negative direction along the voltage axis, as shown by gating kinetics. The molecular docking study showed NOB formed a π-π stacking interaction with rNav1.5 and rNav1.5/QQQ upon Phe-1762, which is the homolog to Phe-1760 in hNaV1.5 and plays an important role in antiarrhythmic action This study reveals that NOB may act as a class I sodium channel anti-arrhythmia agent.
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Affiliation(s)
- Youwei Gu
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou 225009, China
| | - Jieru Wang
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou 225009, China
| | - Mengting Li
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou 225009, China
| | - Fei Zhong
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou 225009, China
| | - Jie Xiang
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou 225009, China
- Correspondence: (Z.X.); (J.X.)
| | - Zhengxin Xu
- Department of Pharmacology, School of Medicine, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- Jingsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou 225001, China
- Jiangsu Key Laboratory of Experimental & Translational Non-Coding RNA Research, Yangzhou 225009, China
- Yeda Institute of Gene and Cell Therapy, Taizhou 318000, China
- Correspondence: (Z.X.); (J.X.)
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Geffeney SL, Cordingley JA, Mitchell K, Hanifin CT. In Silico Analysis of Tetrodotoxin Binding in Voltage-Gated Sodium Ion Channels from Toxin-Resistant Animal Lineages. Mar Drugs 2022; 20:md20110723. [PMID: 36422001 PMCID: PMC9698786 DOI: 10.3390/md20110723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 11/11/2022] [Accepted: 11/15/2022] [Indexed: 11/21/2022] Open
Abstract
Multiple animal species have evolved resistance to the neurotoxin tetrodotoxin (TTX) through changes in voltage-gated sodium ion channels (VGSCs). Amino acid substitutions in TTX-resistant lineages appear to be positionally convergent with changes in homologous residues associated with reductions in TTX block. We used homology modeling coupled with docking simulations to test whether positionally convergent substitutions generate functional convergence at the level of TTX–channel interactions. We found little evidence that amino acids at convergent positions generated similar patterns among TTX-resistant animal lineages across several metrics, including number of polar contacts, polar contact position, and estimates of binding energy. Though binding energy values calculated for TTX docking were reduced for some TTX-resistant channels, not all TTX-resistant channels and not all of our analyses returned reduced binding energy values for TTX-resistant channels. Our results do not support a simple model of toxin resistance where a reduced number of bonds between TTX and the channel protein prevents blocking. Rather models that incorporate flexibility and movement of the protein overall may better describe how homologous substitutions in the channel cause changes in TTX block.
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