1
|
Chan M, Sahakyan H, Eldstrom J, Sastre D, Wang Y, Dou Y, Pourrier M, Vardanyan V, Fedida D. A generic binding pocket for small molecule IKs activators at the extracellular inter-subunit interface of KCNQ1 and KCNE1 channel complexes. eLife 2023; 12:RP87038. [PMID: 37707495 PMCID: PMC10501768 DOI: 10.7554/elife.87038] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023] Open
Abstract
The cardiac IKs ion channel comprises KCNQ1, calmodulin, and KCNE1 in a dodecameric complex which provides a repolarizing current reserve at higher heart rates and protects from arrhythmia syndromes that cause fainting and sudden death. Pharmacological activators of IKs are therefore of interest both scientifically and therapeutically for treatment of IKs loss-of-function disorders. One group of chemical activators are only active in the presence of the accessory KCNE1 subunit and here we investigate this phenomenon using molecular modeling techniques and mutagenesis scanning in mammalian cells. A generalized activator binding pocket is formed extracellularly by KCNE1, the domain-swapped S1 helices of one KCNQ1 subunit and the pore/turret region made up of two other KCNQ1 subunits. A few residues, including K41, A44 and Y46 in KCNE1, W323 in the KCNQ1 pore, and Y148 in the KCNQ1 S1 domain, appear critical for the binding of structurally diverse molecules, but in addition, molecular modeling studies suggest that induced fit by structurally different molecules underlies the generalized nature of the binding pocket. Activation of IKs is enhanced by stabilization of the KCNQ1-S1/KCNE1/pore complex, which ultimately slows deactivation of the current, and promotes outward current summation at higher pulse rates. Our results provide a mechanistic explanation of enhanced IKs currents by these activator compounds and provide a map for future design of more potent therapeutically useful molecules.
Collapse
Affiliation(s)
- Magnus Chan
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British ColumbiaVancouverCanada
| | - Harutyun Sahakyan
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular BiologyYerevanArmenia
| | - Jodene Eldstrom
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British ColumbiaVancouverCanada
| | - Daniel Sastre
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British ColumbiaVancouverCanada
| | - Yundi Wang
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British ColumbiaVancouverCanada
| | - Ying Dou
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British ColumbiaVancouverCanada
| | - Marc Pourrier
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British ColumbiaVancouverCanada
| | - Vitya Vardanyan
- Molecular Neuroscience Group, Institute of Molecular BiologyYerevanArmenia
| | - David Fedida
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British ColumbiaVancouverCanada
| |
Collapse
|
2
|
van Bavel JJA, Beekman HDM, Smoczyńska A, van der Heyden MAG, Vos MA. I Ks Activator ML277 Mildly Affects Repolarization and Arrhythmic Outcome in the CAVB Dog Model. Biomedicines 2023; 11:biomedicines11041147. [PMID: 37189765 DOI: 10.3390/biomedicines11041147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/09/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023] Open
Abstract
Long QT syndrome type 1 with affected IKs is associated with a high risk for developing Torsade de Pointes (TdP) arrhythmias and eventually sudden cardiac death. Therefore, it is of high interest to explore drugs that target IKs as antiarrhythmics. We examined the antiarrhythmic effect of IKs channel activator ML277 in the chronic atrioventricular block (CAVB) dog model. TdP arrhythmia sensitivity was tested in anesthetized mongrel dogs (n = 7) with CAVB in series: (1) induction experiment at 4 ± 2 weeks CAVB: TdP arrhythmias were induced with our standardized protocol using dofetilide (0.025 mg/kg), and (2) prevention experiment at 10 ± 2 weeks CAVB: the antiarrhythmic effect of ML277 (0.6-1.0 mg/kg) was tested by infusion for 5 min preceding dofetilide. ML277: (1) temporarily prevented repolarization prolongation induced by dofetilide (QTc: 538 ± 65 ms at induction vs. 393 ± 18 ms at prevention, p < 0.05), (2) delayed the occurrence of the first arrhythmic event upon dofetilide (from 129 ± 28 s to 180 ± 51 s, p < 0.05), and (3) decreased the arrhythmic outcome with a significant reduction in the number of TdP arrhythmias, TdP score, arrhythmia score and total arrhythmic events (from 669 ± 132 to 401 ± 228, p < 0.05). IKs channel activation by ML277 temporarily suppressed QT interval prolongation, delayed the occurrence of the first arrhythmic event and reduced the arrhythmic outcome in the CAVB dog model.
Collapse
Affiliation(s)
- Joanne J A van Bavel
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, 3584 Utrecht, The Netherlands
| | - Henriëtte D M Beekman
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, 3584 Utrecht, The Netherlands
| | - Agnieszka Smoczyńska
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, 3584 Utrecht, The Netherlands
| | - Marcel A G van der Heyden
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, 3584 Utrecht, The Netherlands
| | - Marc A Vos
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, 3584 Utrecht, The Netherlands
| |
Collapse
|
3
|
Schroeter CB, Nelke C, Schewe M, Spohler L, Herrmann AM, Müntefering T, Huntemann N, Kuzikov M, Gribbon P, Albrecht S, Bock S, Hundehege P, Neelsen LC, Baukrowitz T, Seebohm G, Wünsch B, Bittner S, Ruck T, Budde T, Meuth SG. Validation of TREK1 ion channel activators as an immunomodulatory and neuroprotective strategy in neuroinflammation. Biol Chem 2023; 404:355-375. [PMID: 36774650 DOI: 10.1515/hsz-2022-0266] [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: 08/30/2022] [Accepted: 01/16/2023] [Indexed: 02/13/2023]
Abstract
Modulation of two-pore domain potassium (K2P) channels has emerged as a novel field of therapeutic strategies as they may regulate immune cell activation and metabolism, inflammatory signals, or barrier integrity. One of these ion channels is the TWIK-related potassium channel 1 (TREK1). In the current study, we report the identification and validation of new TREK1 activators. Firstly, we used a modified potassium ion channel assay to perform high-throughput-screening of new TREK1 activators. Dose-response studies helped to identify compounds with a high separation between effectiveness and toxicity. Inside-out patch-clamp measurements of Xenopus laevis oocytes expressing TREK1 were used for further validation of these activators regarding specificity and activity. These approaches yielded three substances, E1, B3 and A2 that robustly activate TREK1. Functionally, we demonstrated that these compounds reduce levels of adhesion molecules on primary human brain and muscle endothelial cells without affecting cell viability. Finally, we studied compound A2 via voltage-clamp recordings as this activator displayed the strongest effect on adhesion molecules. Interestingly, A2 lacked TREK1 activation in the tested neuronal cell type. Taken together, this study provides data on novel TREK1 activators that might be employed to pharmacologically modulate TREK1 activity.
Collapse
Affiliation(s)
- Christina B Schroeter
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Christopher Nelke
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Marcus Schewe
- Institute of Physiology, Christian-Albrechts University Kiel, Hermann-Rodewald-Straße 5, 24118 Kiel, Germany
| | - Lucas Spohler
- Department of Neurology with Institute for Translational Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
| | - Alexander M Herrmann
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Thomas Müntefering
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Niklas Huntemann
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Maria Kuzikov
- Fraunhofer Institute for Translational Medicine and Pharmacology (ITMP), Schnackenburgallee 114, D-22525 Hamburg, Germany
- Fraunhofer Cluster of Excellence for Immune mediated diseases (CIMD), Theodor-Stern-Kai 7, D-60596 Frankfurt, Germany
| | - Philip Gribbon
- Fraunhofer Institute for Translational Medicine and Pharmacology (ITMP), Schnackenburgallee 114, D-22525 Hamburg, Germany
- Fraunhofer Cluster of Excellence for Immune mediated diseases (CIMD), Theodor-Stern-Kai 7, D-60596 Frankfurt, Germany
| | - Sarah Albrecht
- Department of Neurology with Institute for Translational Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
| | - Stefanie Bock
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Petra Hundehege
- Department of Neurology with Institute for Translational Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
| | - Lea Christine Neelsen
- Institute of Physiology, Christian-Albrechts University Kiel, Hermann-Rodewald-Straße 5, 24118 Kiel, Germany
| | - Thomas Baukrowitz
- Institute of Physiology, Christian-Albrechts University Kiel, Hermann-Rodewald-Straße 5, 24118 Kiel, Germany
| | - Guiscard Seebohm
- IfGH-Cellular Electrophysiology, Department of Cardiology and Angiology, University Hospital of Münster, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
| | - Bernhard Wünsch
- Institute for Pharmaceutical and Medicinal Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstraße 48, D-48149 Münster, Germany
| | - Stefan Bittner
- Department of Neurology, University Medical Center Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany
| | - Tobias Ruck
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Thomas Budde
- Institute of Physiology I, University of Münster, Robert-Koch-Straße 27A, D-48149 Münster, Germany
| | - Sven G Meuth
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| |
Collapse
|
4
|
Liu LX, Gu RR, Jin Y, Chen XQ, Li XW, Zheng YM, Gao ZB, Guo YW. Diversity-oriented synthesis of marine polybrominated diphenyl ethers as potential KCNQ potassium channel activators. Bioorg Chem 2022; 126:105909. [DOI: 10.1016/j.bioorg.2022.105909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/03/2022] [Accepted: 05/22/2022] [Indexed: 01/10/2023]
|
5
|
Willegems K, Eldstrom J, Kyriakis E, Ataei F, Sahakyan H, Dou Y, Russo S, Van Petegem F, Fedida D. Structural and electrophysiological basis for the modulation of KCNQ1 channel currents by ML277. Nat Commun 2022; 13:3760. [PMID: 35768468 PMCID: PMC9243137 DOI: 10.1038/s41467-022-31526-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 06/17/2022] [Indexed: 01/10/2023] Open
Abstract
The KCNQ1 ion channel plays critical physiological roles in electrical excitability and K+ recycling in organs including the heart, brain, and gut. Loss of function is relatively common and can cause sudden arrhythmic death, sudden infant death, epilepsy and deafness. Here, we report cryogenic electron microscopic (cryo-EM) structures of Xenopus KCNQ1 bound to Ca2+/Calmodulin, with and without the KCNQ1 channel activator, ML277. A single binding site for ML277 was identified, localized to a pocket lined by the S4-S5 linker, S5 and S6 helices of two separate subunits. Several pocket residues are not conserved in other KCNQ isoforms, explaining specificity. MD simulations and point mutations support this binding location for ML277 in open and closed channels and reveal that prevention of inactivation is an important component of the activator effect. Our work provides direction for therapeutic intervention targeting KCNQ1 loss of function pathologies including long QT interval syndrome and seizures. KCNQ1 channels are active in heart, brain and gut. Functional loss causes epilepsy and sudden arrhythmic death. Here, authors describe a key activator drug binding site, explaining isoform and drug selectivity, and point the way for new drug design.
Collapse
Affiliation(s)
- Katrien Willegems
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada.,Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Jodene Eldstrom
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Efthimios Kyriakis
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Fariba Ataei
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Harutyun Sahakyan
- National Center for Biotechnology Information, National Library of Medicine, National Institutes for Health, Bethesda, MD, USA
| | - Ying Dou
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Sophia Russo
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada.
| | - David Fedida
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada.
| |
Collapse
|
6
|
Triclosan is a KCNQ3 potassium channel activator. Pflugers Arch 2022; 474:721-732. [PMID: 35459955 DOI: 10.1007/s00424-022-02692-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/24/2022] [Accepted: 04/13/2022] [Indexed: 01/10/2023]
Abstract
KCNQ channels participate in the physiology of several cell types. In neurons of the central nervous system, the primary subunits are KCNQ2, 3, and 5. Activation of these channels silence the neurons, limiting action potential duration and preventing high-frequency action potential burst. Loss-of-function mutations of the KCNQ channels are associated with a wide spectrum of phenotypes characterized by hyperexcitability. Hence, pharmacological activation of these channels is an attractive strategy to treat epilepsy and other hyperexcitability conditions as are the evolution of stroke and traumatic brain injury. In this work we show that triclosan, a bactericide widely used in personal care products, activates the KCNQ3 channels but not the KCNQ2. Triclosan induces a voltage shift in the activation, increases the conductance, and slows the closing of the channel. The response is independent of PIP2. Molecular docking simulations together with site-directed mutagenesis suggest that the putative binding site is in the voltage sensor domain. Our results indicate that triclosan is a new activator for KCNQ channels.
Collapse
|
7
|
von Hellfeld R, Pannetier P, Braunbeck T. Specificity of time- and dose-dependent morphological endpoints in the fish embryo acute toxicity (FET) test for substances with diverse modes of action: the search for a "fingerprint". ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:16176-16192. [PMID: 34643865 PMCID: PMC8827326 DOI: 10.1007/s11356-021-16354-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
The fish embryo acute toxicity (FET) test with the zebrafish (Danio rerio) embryo according to OECD TG 236 was originally developed as an alternative test method for acute fish toxicity testing according to, e.g., OECD TG 203. Given the versatility of the protocol, however, the FET test has found application beyond acute toxicity testing as a common tool in environmental hazard and risk assessment. Whereas the standard OECD guideline is restricted to four core endpoints (coagulation as well as lack of somite formation, heartbeat, and tail detachment) for simple, rapid assessment of acute toxicity, further endpoints can easily be integrated into the FET test protocol. This has led to the hypothesis that an extended FET test might allow for the identification of different classes of toxicants via a "fingerprint" of morphological observations. To test this hypothesis, the present study investigated a set of 18 compounds with highly diverse modes of action with respect to acute and sublethal endpoints. Especially at higher concentrations, most observations proved toxicant-unspecific. With decreasing concentrations, however, observations declined in number, but gained in specificity. Specific observations may at best be made at test concentrations ≤ EC10. The existence of a "fingerprint" based on morphological observations in the FET is, therefore, highly unlikely in the range of acute toxicity, but cannot be excluded for experiments at sublethal concentrations.
Collapse
Affiliation(s)
- Rebecca von Hellfeld
- Center for Organismal Studies, Aquatic Ecology and Toxicology Section, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
- University of Aberdeen, Institute of Biological and Environmental Science, 23 St Machar Drive, AB24 3UU, Aberdeen, UK.
| | - Pauline Pannetier
- Center for Organismal Studies, Aquatic Ecology and Toxicology Section, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany
| | - Thomas Braunbeck
- Center for Organismal Studies, Aquatic Ecology and Toxicology Section, University of Heidelberg, Im Neuenheimer Feld 504, 69120, Heidelberg, Germany.
| |
Collapse
|
8
|
Eldstrom J, McAfee DA, Dou Y, Wang Y, Fedida D. ML277 regulates KCNQ1 single-channel amplitudes and kinetics, modified by voltage sensor state. J Gen Physiol 2021; 153:212696. [PMID: 34636894 PMCID: PMC8515649 DOI: 10.1085/jgp.202112969] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/16/2021] [Accepted: 09/15/2021] [Indexed: 11/25/2022] Open
Abstract
KCNQ1 is a pore-forming K+ channel subunit critically important to cardiac repolarization at high heart rates. (2R)-N-[4-(4-methoxyphenyl)-2-thiazolyl]-1-[(4-methylphenyl)sulfonyl]-2 piperidinecarboxamide, or ML277, is an activator of this channel that rescues function of pathophysiologically important mutant channel complexes in human induced pluripotent stem cell–derived cardiomyocytes, and that therefore may have therapeutic potential. Here we extend our understanding of ML277 actions through cell-attached single-channel recordings of wild-type and mutant KCNQ1 channels with voltage sensor domains fixed in resting, intermediate, and activated states. ML277 has profound effects on KCNQ1 single-channel kinetics, eliminating the flickering nature of the openings, converting them to discrete opening bursts, and increasing their amplitudes approximately threefold. KCNQ1 single-channel behavior after ML277 treatment most resembles IO state-locked channels (E160R/R231E) rather than AO state channels (E160R/R237E), suggesting that at least during ML277 treatment, KCNQ1 does not frequently visit the AO state. Introduction of KCNE1 subunits reduces the effectiveness of ML277, but some enhancement of single-channel openings is still observed.
Collapse
Affiliation(s)
- Jodene Eldstrom
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Donald A McAfee
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Ying Dou
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Yundi Wang
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, Canada
| | - David Fedida
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, Canada
| |
Collapse
|
9
|
Borgini M, Mondal P, Liu R, Wipf P. Chemical modulation of Kv7 potassium channels. RSC Med Chem 2021; 12:483-537. [PMID: 34046626 PMCID: PMC8128042 DOI: 10.1039/d0md00328j] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/01/2020] [Indexed: 01/10/2023] Open
Abstract
The rising interest in Kv7 modulators originates from their ability to evoke fundamental electrophysiological perturbations in a tissue-specific manner. A large number of therapeutic applications are, in part, based on the clinical experience with two broad-spectrum Kv7 agonists, flupirtine and retigabine. Since precise molecular structures of human Kv7 channel subtypes in closed and open states have only very recently started to emerge, computational studies have traditionally been used to analyze binding modes and direct the development of more potent and selective Kv7 modulators with improved safety profiles. Herein, the synthetic and medicinal chemistry of small molecule modulators and the representative biological properties are summarized. Furthermore, new therapeutic applications supported by in vitro and in vivo assay data are suggested.
Collapse
Affiliation(s)
- Matteo Borgini
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Pravat Mondal
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Ruiting Liu
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| |
Collapse
|
10
|
Lübke M, Schreiber JA, Le Quoc T, Körber F, Müller J, Sivanathan S, Matschke V, Schubert J, Strutz-Seebohm N, Seebohm G, Scherkenbeck J. Rottlerin: Structure Modifications and KCNQ1/KCNE1 Ion Channel Activity. ChemMedChem 2020; 15:1078-1088. [PMID: 32338831 PMCID: PMC7318133 DOI: 10.1002/cmdc.202000083] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/20/2020] [Indexed: 11/10/2022]
Abstract
The slow delayed rectifier potassium current (IKs ) is formed by the KCNQ1 (Kv 7.1) channel, an ion channel of four α-subunits that modulates KCNE1 β-subunits. IKs is central to the repolarization of the cardiac action potential. Loss of function mutation reducing ventricular cardiac IKs cause the long-QT syndrome (LQTS), a disorder that predisposes patients to arrhythmia and sudden death. Current therapy for LQTS is inadequate. Rottlerin, a natural product of the kamala tree, activates IKs and has the potential to provide a new strategy for rational drug therapy. In this study, we show that simple modifications such as penta-acetylation or penta-methylation of rottlerin blunts activation activity. Total synthesis was used to prepare side-chain-modified derivatives that slowed down KCNQ1/KCNE1 channel deactivation to different degrees. A binding hypothesis of rottlerin is provided that opens the way to improved IKs activators as novel therapeutics for the treatment of LQTS.
Collapse
Affiliation(s)
- Marco Lübke
- Faculty of Mathematics and Natural Sciences, University Wuppertal, 42119, Wuppertal, Germany
| | - Julian A Schreiber
- Institut für Genetik von Herzerkrankungen, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany
| | - Thang Le Quoc
- Department of Chemistry, Hue University, 34 Le Loi St., Hue City, Vietnam
| | - Florian Körber
- Faculty of Mathematics and Natural Sciences, University Wuppertal, 42119, Wuppertal, Germany
| | - Jasmin Müller
- Faculty of Mathematics and Natural Sciences, University Wuppertal, 42119, Wuppertal, Germany
| | | | - Veronika Matschke
- Medical Faculty, Institute of Anatomy Department of Cytology, Ruhr University Bochum, 44801, Bochum, Germany
| | - Janina Schubert
- Institut für Genetik von Herzerkrankungen, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany
| | - Nathalie Strutz-Seebohm
- Institut für Genetik von Herzerkrankungen, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany
| | - Guiscard Seebohm
- Institut für Genetik von Herzerkrankungen, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149, Münster, Germany
| | - Jürgen Scherkenbeck
- Faculty of Mathematics and Natural Sciences, University Wuppertal, 42119, Wuppertal, Germany
| |
Collapse
|
11
|
Wang Y, Eldstrom J, Fedida D. The I Ks Ion Channel Activator Mefenamic Acid Requires KCNE1 and Modulates Channel Gating in a Subunit-Dependent Manner. Mol Pharmacol 2019; 97:132-144. [PMID: 31722973 DOI: 10.1124/mol.119.117952] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 11/04/2019] [Indexed: 01/05/2023] Open
Abstract
The pairing of KCNQ1 and KCNE1 subunits together mediates the cardiac slow delayed rectifier current (I Ks ), which is partly responsible for cardiomyocyte repolarization and physiologic shortening of the cardiac action potential. Mefenamic acid, a nonsteroidal anti-inflammatory drug, has been identified as an I Ks activator. Here, we provide a biophysical and pharmacological characterization of mefenamic acid's effect on I Ks Using whole-cell patch clamp, we show that mefenamic acid enhances I Ks activity in both a dose- and stoichiometry-dependent fashion by changing the slowly activating and deactivating I Ks current into an almost linear current with instantaneous onset and slowed tail current decay, sensitive to the I Ks blocker (3R,4S)-(+)-N-[3-hydroxy-2,2-dimethyl-6-(4,4,4-trifluorobutoxy) chroman-4-yl]-N-methylmethanesulfonamide (HMR1556). Both single channels, which reveal no change in the maximum conductance, and whole-cell studies, which reveal a dramatically altered conductance-voltage relationship despite increasingly longer interpulse intervals, suggest mefenamic acid decreases the voltage sensitivity of the I Ks channel and shifts channel gating kinetics toward more negative potentials. Modeling studies revealed that changes in voltage sensor activation kinetics are sufficient to reproduce the dose and frequency dependence of mefenamic acid action on I Ks channels. Mutational analysis showed that mefenamic acid's effect on I Ks required residue K41 and potentially other surrounding residues on the extracellular surface of KCNE1, and explains why the KCNQ1 channel alone is insensitive to up to 1 mM mefenamic acid. Given that mefenamic acid can enhance all I Ks channel complexes containing different ratios of KCNQ1 to KCNE1, it may provide a promising therapeutic approach to treating life-threatening cardiac arrhythmia syndromes. SIGNIFICANCE STATEMENT: The channels which generate the cardiac slow delayed rectifier K+ current (I Ks ) are composed of KCNQ1 and KCNE1 subunits. Due to the critical role played by I Ks in heartbeat regulation, enhancing I Ks current has been identified as a promising therapeutic strategy to treat various heart rhythm diseases. Most I Ks activators, unfortunately, only work on KCNQ1 alone and not the physiologically relevant I Ks channel. We have demonstrated that mefenamic acid can enhance I Ks in a dose- and stoichiometry-dependent fashion, regulated by its interactions with KCNE1.
Collapse
Affiliation(s)
- Yundi Wang
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jodene Eldstrom
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - David Fedida
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
12
|
Hou P, Shi J, White KM, Gao Y, Cui J. ML277 specifically enhances the fully activated open state of KCNQ1 by modulating VSD-pore coupling. eLife 2019; 8:e48576. [PMID: 31329101 PMCID: PMC6684268 DOI: 10.7554/elife.48576] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/22/2019] [Indexed: 12/16/2022] Open
Abstract
Upon membrane depolarization, the KCNQ1 potassium channel opens at the intermediate (IO) and activated (AO) states of the stepwise voltage-sensing domain (VSD) activation. In the heart, KCNQ1 associates with KCNE1 subunits to form IKs channels that regulate heart rhythm. KCNE1 suppresses the IO state so that the IKs channel opens only to the AO state. Here, we tested modulations of human KCNQ1 channels by an activator ML277 in Xenopus oocytes. It exclusively changes the pore opening properties of the AO state without altering the IO state, but does not affect VSD activation. These observations support a distinctive mechanism responsible for the VSD-pore coupling at the AO state that is sensitive to ML277 modulation. ML277 provides insights and a tool to investigate the gating mechanism of KCNQ1 channels, and our study reveals a new strategy for treating long QT syndrome by specifically enhancing the AO state of native IKs currents.
Collapse
Affiliation(s)
- Panpan Hou
- Department of Biomedical EngineeringWashington UniversitySt. LouisUnited States
- Center for the Investigation of Membrane Excitability DisordersWashington UniversitySt. LouisUnited States
- Cardiac Bioelectricity and Arrhythmia CenterWashington UniversitySt. LouisUnited States
| | - Jingyi Shi
- Department of Biomedical EngineeringWashington UniversitySt. LouisUnited States
- Center for the Investigation of Membrane Excitability DisordersWashington UniversitySt. LouisUnited States
- Cardiac Bioelectricity and Arrhythmia CenterWashington UniversitySt. LouisUnited States
| | - Kelli McFarland White
- Department of Biomedical EngineeringWashington UniversitySt. LouisUnited States
- Center for the Investigation of Membrane Excitability DisordersWashington UniversitySt. LouisUnited States
- Cardiac Bioelectricity and Arrhythmia CenterWashington UniversitySt. LouisUnited States
| | | | - Jianmin Cui
- Department of Biomedical EngineeringWashington UniversitySt. LouisUnited States
- Center for the Investigation of Membrane Excitability DisordersWashington UniversitySt. LouisUnited States
- Cardiac Bioelectricity and Arrhythmia CenterWashington UniversitySt. LouisUnited States
| |
Collapse
|
13
|
Ramu J, Konak T, Paule MG, Hanig JP, Liachenko S. Longitudinal diffusion tensor imaging of the rat brain after hexachlorophene exposure. Neurotoxicology 2016; 56:225-232. [PMID: 27555423 DOI: 10.1016/j.neuro.2016.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 08/17/2016] [Accepted: 08/17/2016] [Indexed: 12/28/2022]
Abstract
Longitudinal MRI employing diffusion tensor imaging and T2 mapping approaches has been applied to investigate the mechanisms of white matter damage caused by acute hexachlorophene neurotoxicity in rats in vivo. Male Sprague-Dawley rats were administered hexachlorophene orally once a day for five consecutive days at a dose of 30mg/kg and were monitored in 7T MRI scanner at days 0 (baseline), 3, 6, 13, and 20 following the first hexachlorophene dose. Quantitative T2 maps as well as a number of diffusion tensor parameters (fractional anisotropy, radial and axial diffusivity, apparent diffusion coefficient, and trace) were calculated from corresponding MR images. T2, as well as all diffusion tensor derived parameters (except fractional anisotropy) showed significant changes during the course of neurotoxicity development. These changes peaked at 6days after the first dose of hexachlorophene (one day after the last dose) and recovered to practically baseline levels at the end of observation (20days from the first dose). While such changes in diffusivity and T2 relaxation clearly demonstrate myelin perturbations consistent with edema, the lack of changes of fractional anisotropy suggests that the structure of the myelin sheath was not disrupted significantly by hexachlorophene in this study. This is also confirmed by the rapid recovery of all observed MRI parameters after cessation of hexachlorophene exposure.
Collapse
Affiliation(s)
- Jaivijay Ramu
- Division of Neurotoxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, United States.
| | - Tetyana Konak
- Division of Neurotoxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, United States.
| | - Merle G Paule
- Division of Neurotoxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, United States.
| | - Joseph P Hanig
- Center for Drug Evaluation and Research, Food and Drug Administration, White Oak, MD, United States.
| | - Serguei Liachenko
- Division of Neurotoxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, United States.
| |
Collapse
|
14
|
Wu W, Sanguinetti MC. Molecular Basis of Cardiac Delayed Rectifier Potassium Channel Function and Pharmacology. Card Electrophysiol Clin 2016; 8:275-84. [PMID: 27261821 DOI: 10.1016/j.ccep.2016.01.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Human cardiomyocytes express 3 distinct types of delayed rectifier potassium channels. Human ether-a-go-go-related gene (hERG) channels conduct the rapidly activating current IKr; KCNQ1/KCNE1 channels conduct the slowly activating current IKs; and Kv1.5 channels conduct an ultrarapid activating current IKur. Here the authors provide a general overview of the mechanistic and structural basis of ion selectivity, gating, and pharmacology of the 3 types of cardiac delayed rectifier potassium ion channels. Most blockers bind to S6 residues that line the central cavity of the channel, whereas activators interact with the channel at 4 symmetric binding sites outside the cavity.
Collapse
Affiliation(s)
- Wei Wu
- Department of Medicine, Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 South 2000 East, Salt Lake City, UT 84112, USA
| | - Michael C Sanguinetti
- Department of Medicine, Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 South 2000 East, Salt Lake City, UT 84112, USA.
| |
Collapse
|
15
|
Abstract
Supplemental Digital Content is Available in the Text. Combining electrophysiology and in vivo pain models, the concept that activation of peripheral KCNQ channels relieves the gout pain is demonstrated. Intense inflammatory pain caused by urate crystals in joints and other tissues is a major symptom of gout. Among therapy drugs that lower urate, benzbromarone (BBR), an inhibitor of urate transporters, is widely used because it is well tolerated and highly effective. We demonstrate that BBR is also an activator of voltage-gated KCNQ potassium channels. In cultured recombinant cells, BBR exhibited significant potentiation effects on KCNQ channels comparable to previously reported classical activators. In native dorsal root ganglion neurons, BBR effectively overcame the suppression of KCNQ currents, and the resultant neuronal hyperexcitability caused by inflammatory mediators, such as bradykinin (BK). Benzbromarone consistently attenuates BK-, formalin-, or monosodium urate–induced inflammatory pain in rat and mouse models. Notably, the analgesic effects of BBR are largely mediated through peripheral and not through central KCNQ channels, an observation supported both by pharmacokinetic studies and in vivo experiments. Moreover, multiple residues in the superficial part of the voltage sensing domain of KCNQ channels were identified critical for the potentiation activity of BBR by a molecular determinant investigation. Our data indicate that activation of peripheral KCNQ channels mediates the pain relief effects of BBR, potentially providing a new strategy for the development of more effective therapies for gout.
Collapse
|
16
|
Li P, Zhu J, Kong Q, Jiang B, Wan X, Yue J, Li M, Jiang H, Li J, Gao Z. The ethylene bis-dithiocarbamate fungicide Mancozeb activates voltage-gated KCNQ2 potassium channel. Toxicol Lett 2013; 219:211-7. [DOI: 10.1016/j.toxlet.2013.03.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 03/15/2013] [Accepted: 03/20/2013] [Indexed: 10/27/2022]
|
17
|
Dynamic subunit stoichiometry confers a progressive continuum of pharmacological sensitivity by KCNQ potassium channels. Proc Natl Acad Sci U S A 2013; 110:8732-7. [PMID: 23650380 DOI: 10.1073/pnas.1300684110] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Voltage-gated KCNQ1 (Kv7.1) potassium channels are expressed abundantly in heart but they are also found in multiple other tissues. Differential coassembly with single transmembrane KCNE beta subunits in different cell types gives rise to a variety of biophysical properties, hence endowing distinct physiological roles for KCNQ1-KCNEx complexes. Mutations in either KCNQ1 or KCNE1 genes result in diseases in brain, heart, and the respiratory system. In addition to complexities arising from existence of five KCNE subunits, KCNE1 to KCNE5, recent studies in heterologous systems suggest unorthodox stoichiometric dynamics in subunit assembly is dependent on KCNE expression levels. The resultant KCNQ1-KCNE channel complexes may have a range of zero to two or even up to four KCNE subunits coassembling per KCNQ1 tetramer. These findings underscore the need to assess the selectivity of small-molecule KCNQ1 modulators on these different assemblies. Here we report a unique small-molecule gating modulator, ML277, that potentiates both homomultimeric KCNQ1 channels and unsaturated heteromultimeric (KCNQ1)4(KCNE1)n (n < 4) channels. Progressive increase of KCNE1 or KCNE3 expression reduces efficacy of ML277 and eventually abolishes ML277-mediated augmentation. In cardiomyocytes, the slowly activating delayed rectifier potassium current, or IKs, is believed to be a heteromultimeric combination of KCNQ1 and KCNE1, but it is not entirely clear whether IKs is mediated by KCNE-saturated KCNQ1 channels or by channels with intermediate stoichiometries. We found ML277 effectively augments IKs current of cultured human cardiomyocytes and shortens action potential duration. These data indicate that unsaturated heteromultimeric (KCNQ1)4(KCNE1)n channels are present as components of IKs and are pharmacologically distinct from KCNE-saturated KCNQ1-KCNE1 channels.
Collapse
|