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Camargo-Ayala L, Bedoya M, Dasí A, Prüser M, Schütte S, Prent-Peñaloza L, Adasme-Carreño F, Kiper AK, Rinné S, Camargo-Ayala PA, Peña-Martínez PA, Bueno-Orovio A, Varela D, Wiedmann F, Márquez Montesinos JCE, Mazola Y, Venturini W, Zúñiga R, Zúñiga L, Schmidt C, Rodriguez B, Ravens U, Decher N, Gutiérrez M, González W. Rational design, synthesis, and evaluation of novel polypharmacological compounds targeting Na V1.5, K V1.5, and K 2P channels for atrial fibrillation. J Biol Chem 2025; 301:108387. [PMID: 40054693 DOI: 10.1016/j.jbc.2025.108387] [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: 07/20/2024] [Revised: 02/04/2025] [Accepted: 03/03/2025] [Indexed: 04/19/2025] Open
Abstract
Atrial fibrillation (AF) involves electrical remodeling of the atria, with ion channels such as NaV1.5, KV1.5, and TASK-1 playing crucial roles. This study investigates acetamide-based compounds designed as multi-target inhibitors of these ion channels to address AF. Compound 6f emerged as the most potent in the series, demonstrating a strong inhibition of TASK-1 (IC50 ∼ 0.3 μM), a moderate inhibition of NaV1.5 (IC50 ∼ 21.2 μM) and a subtle inhibition of KV1.5 (IC50 ∼ 81.5 μM), alongside unexpected activation of TASK-4 (∼ 40% at 100 μM). Functional assays on human atrial cardiomyocytes from sinus rhythm (SR) and patients with AF revealed that 6f reduced action potential amplitude in SR (indicating NaV1.5 block), while in AF it increased action potential duration (APD), reflecting high affinity for TASK-1. Additionally, 6f caused hyperpolarization of the resting membrane potential in AF cardiomyocytes, consistent with the observed TASK-4 activation. Mathematical modeling further validated its efficacy in reducing AF burden. Pharmacokinetic analyses suggest favorable absorption and low toxicity. These findings identify 6f as a promising multi-target therapeutic candidate for AF management.
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Affiliation(s)
- Lorena Camargo-Ayala
- Doctorado en Ciencias Mención I + D de Productos Bioactivos, Instituto de Química de Recursos Naturales, Laboratorio de Síntesis Orgánica, Universidad de Talca, Talca, Chile
| | - Mauricio Bedoya
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca, Chile; Laboratorio de Bioinformática y Química Computacional (LBQC), Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca, Chile
| | - Albert Dasí
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, UK
| | - Merten Prüser
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), partner site Heidelberg /Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Sven Schütte
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
| | - Luis Prent-Peñaloza
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Viña del Mar, Chile
| | - Francisco Adasme-Carreño
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca, Chile; Laboratorio de Bioinformática y Química Computacional (LBQC), Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca, Chile
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany; Institute of Physiology, University Medicine Greifswald, Greifswald, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
| | - Paola Andrea Camargo-Ayala
- Doctorado en Ciencias Biomédicas, Laboratorio de Patología Molecular, Departamento de Ciencias Básicas Biomédicas, Facultad de Ciencias de la Salud, Universidad de Talca, Talca, Chile
| | - Paula A Peña-Martínez
- Doctorado en Ciencias Agrarias, Facultad de Ciencias Agrarias, Universidad de Talca, Talca, Chile; Laboratorio de Química Enológica, Facultad de Ciencias Agrarias, Universidad de Talca, Talca, Chile
| | - Alfonso Bueno-Orovio
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, UK
| | - Diego Varela
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Santiago, Chile; Program of Physiology and Biophysics, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Felix Wiedmann
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), partner site Heidelberg /Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - José C E Márquez Montesinos
- Centro de Bioinformática, Simulación y Modelado (CBSM), Universidad de Talca, Talca, Chile; Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Talca, Chile
| | - Yuliet Mazola
- Centro de Bioinformática, Simulación y Modelado (CBSM), Universidad de Talca, Talca, Chile; Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Talca, Chile
| | - Whitney Venturini
- Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca, Chile
| | - Rafael Zúñiga
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Talca, Chile
| | - Leandro Zúñiga
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Talca, Chile
| | - Constanze Schmidt
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), partner site Heidelberg /Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Blanca Rodriguez
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, UK
| | - Ursula Ravens
- German Atrial Fibrillation Competence NETwork (AFNET), Freiburg, Germany; Institute of Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center - University of Freiburg and Faculty of Medicine, Freiburg, Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany.
| | - Margarita Gutiérrez
- Laboratorio Síntesis Orgánica y Actividad Biológica (LSO-Act-Bio), Instituto de Química de Recursos Naturales, Universidad de Talca, Talca, Chile.
| | - Wendy González
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Santiago, Chile; Centro de Bioinformática, Simulación y Modelado (CBSM), Universidad de Talca, Talca, Chile.
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Zhang Y, Li J, Pan J, Deng S. Research progress of two-pore potassium channel in myocardial ischemia-reperfusion injury. Front Physiol 2024; 15:1473501. [PMID: 39534859 PMCID: PMC11554511 DOI: 10.3389/fphys.2024.1473501] [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: 07/31/2024] [Accepted: 10/07/2024] [Indexed: 11/16/2024] Open
Abstract
Myocardial ischemia-reperfusion injury (MIRI) is a secondary injury caused by restoring blood flow after acute myocardial infarction, which may lead to serious arrhythmia and heart damage. In recent years, the role of potassium channels in MIRI has attracted much attention, especially the members of the two-pore domain potassium (K2P) channel family. K2P channel has unique structure and function, and the formation of its heterodimer increases its functional diversity. This paper reviews the structural characteristics, types, expression and physiological functions of K2P channel in the heart. In particular, we pay attention to whether members of the subfamily such as TWIK, TREK, TASK, TALK, THIK and TRESK participate in MIRI and their related mechanisms. Future research will help to reveal the molecular mechanism of K2P channel in MIRI and provide new strategies for the treatment of cardiovascular diseases.
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Affiliation(s)
| | | | | | - Shengli Deng
- Department of Anesthesiology, The Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
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3
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Müller ME, Petersenn F, Hackbarth J, Pfeiffer J, Gampp H, Frey N, Lugenbiel P, Thomas D, Rahm AK. Electrophysiological Effects of the Sodium-Glucose Co-Transporter-2 (SGLT2) Inhibitor Dapagliflozin on Human Cardiac Potassium Channels. Int J Mol Sci 2024; 25:5701. [PMID: 38891889 PMCID: PMC11172209 DOI: 10.3390/ijms25115701] [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: 04/26/2024] [Revised: 05/17/2024] [Accepted: 05/20/2024] [Indexed: 06/21/2024] Open
Abstract
The sodium-glucose co-transporter-2 (SGLT2) inhibitor dapagliflozin is increasingly used in the treatment of diabetes and heart failure. Dapagliflozin has been associated with reduced incidence of atrial fibrillation (AF) in clinical trials. We hypothesized that the favorable antiarrhythmic outcome of dapagliflozin use may be caused in part by previously unrecognized effects on atrial repolarizing potassium (K+) channels. This study was designed to assess direct pharmacological effects of dapagliflozin on cloned ion channels Kv11.1, Kv1.5, Kv4.3, Kir2.1, K2P2.1, K2P3.1, and K2P17.1, contributing to IKur, Ito, IKr, IK1, and IK2P K+ currents. Human channels coded by KCNH2, KCNA5, KCND3, KCNJ2, KCNK2, KCNK3, and KCNK17 were heterologously expressed in Xenopus laevis oocytes, and currents were recorded using the voltage clamp technique. Dapagliflozin (100 µM) reduced Kv11.1 and Kv1.5 currents, whereas Kir2.1, K2P2.1, and K2P17.1 currents were enhanced. The drug did not significantly affect peak current amplitudes of Kv4.3 or K2P3.1 K+ channels. Biophysical characterization did not reveal significant effects of dapagliflozin on current-voltage relationships of study channels. In conclusion, dapagliflozin exhibits direct functional interactions with human atrial K+ channels underlying IKur, IKr, IK1, and IK2P currents. Substantial activation of K2P2.1 and K2P17.1 currents could contribute to the beneficial antiarrhythmic outcome associated with the drug. Indirect or chronic effects remain to be investigated in vivo.
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Affiliation(s)
- Mara Elena Müller
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; (M.E.M.); (P.L.); (D.T.)
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Finn Petersenn
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; (M.E.M.); (P.L.); (D.T.)
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Juline Hackbarth
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; (M.E.M.); (P.L.); (D.T.)
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Julia Pfeiffer
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; (M.E.M.); (P.L.); (D.T.)
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Heike Gampp
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; (M.E.M.); (P.L.); (D.T.)
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Norbert Frey
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; (M.E.M.); (P.L.); (D.T.)
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Patrick Lugenbiel
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; (M.E.M.); (P.L.); (D.T.)
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Dierk Thomas
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; (M.E.M.); (P.L.); (D.T.)
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Ann-Kathrin Rahm
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; (M.E.M.); (P.L.); (D.T.)
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg University, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
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Rahm AK, Hackbarth J, Müller ME, Pfeiffer J, Gampp H, Petersenn F, Rivinius R, Frey N, Lugenbiel P, Thomas D. Differential Effects of the Betablockers Carvedilol, Metoprolol and Bisoprolol on Cardiac K v4.3 (I to) Channel Isoforms. Int J Mol Sci 2023; 24:13842. [PMID: 37762145 PMCID: PMC10530285 DOI: 10.3390/ijms241813842] [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: 07/30/2023] [Revised: 09/03/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Cardiac Kv4.3 channels contribute to the transient outward K+ current, Ito, during early repolarization of the cardiac action potential. Two different isoforms of Kv4.3 are present in the human ventricle and exhibit differential remodeling in heart failure (HF). Cardioselective betablockers are a cornerstone of HF with reduced ejection fraction therapy as well as ventricular arrhythmia treatment. In this study we examined pharmacological effects of betablockers on both Kv4.3 isoforms to explore their potential for isoform-specific therapy. Kv4.3 isoforms were expressed in Xenopus laevis oocytes and incubated with the respective betablockers. Dose-dependency and biophysical characteristics were examined. HEK 293T-cells were transfected with the two Kv4.3 isoforms and analyzed with Western blots. Carvedilol (100 µM) blocked Kv4.3 L by 77 ± 2% and Kv4.3 S by 67 ± 6%, respectively. Metoprolol (100 µM) was less effective with inhibition of 37 ± 3% (Kv4.3 L) and 35 ± 4% (Kv4.3 S). Bisoprolol showed no inhibitory effect. Current reduction was not caused by changes in Kv4.3 protein expression. Carvedilol inhibited Kv4.3 channels at physiologically relevant concentrations, affecting both isoforms. Metoprolol showed a weaker blocking effect and bisoprolol did not exert an effect on Kv4.3. Blockade of repolarizing Kv4.3 channels by carvedilol and metoprolol extend their pharmacological mechanism of action, potentially contributing beneficial antiarrhythmic effects in normal and failing hearts.
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Affiliation(s)
- Ann-Kathrin Rahm
- Heidelberg Center for Heart Rhythm Disorders, Heidelberg University Hospital, 69120 Heidelberg, Germany (M.E.M.); (R.R.); (P.L.)
- Department of Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Juline Hackbarth
- Heidelberg Center for Heart Rhythm Disorders, Heidelberg University Hospital, 69120 Heidelberg, Germany (M.E.M.); (R.R.); (P.L.)
- Department of Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Mara E. Müller
- Heidelberg Center for Heart Rhythm Disorders, Heidelberg University Hospital, 69120 Heidelberg, Germany (M.E.M.); (R.R.); (P.L.)
- Department of Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Julia Pfeiffer
- Heidelberg Center for Heart Rhythm Disorders, Heidelberg University Hospital, 69120 Heidelberg, Germany (M.E.M.); (R.R.); (P.L.)
- Department of Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Heike Gampp
- Heidelberg Center for Heart Rhythm Disorders, Heidelberg University Hospital, 69120 Heidelberg, Germany (M.E.M.); (R.R.); (P.L.)
- Department of Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Finn Petersenn
- Heidelberg Center for Heart Rhythm Disorders, Heidelberg University Hospital, 69120 Heidelberg, Germany (M.E.M.); (R.R.); (P.L.)
- Department of Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Rasmus Rivinius
- Heidelberg Center for Heart Rhythm Disorders, Heidelberg University Hospital, 69120 Heidelberg, Germany (M.E.M.); (R.R.); (P.L.)
- Department of Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Norbert Frey
- Heidelberg Center for Heart Rhythm Disorders, Heidelberg University Hospital, 69120 Heidelberg, Germany (M.E.M.); (R.R.); (P.L.)
- Department of Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Patrick Lugenbiel
- Heidelberg Center for Heart Rhythm Disorders, Heidelberg University Hospital, 69120 Heidelberg, Germany (M.E.M.); (R.R.); (P.L.)
- Department of Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Dierk Thomas
- Heidelberg Center for Heart Rhythm Disorders, Heidelberg University Hospital, 69120 Heidelberg, Germany (M.E.M.); (R.R.); (P.L.)
- Department of Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
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Song T, Hao Y, Wang M, Li T, Zhao C, Li J, Hou Y. Sophoridine manifests as a leading compound for anti-arrhythmia with multiple ion-channel blocking effects. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 112:154688. [PMID: 36738478 DOI: 10.1016/j.phymed.2023.154688] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 01/09/2023] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Sophoridine (SR) has shown the potential to be an antiarrhythmic agent. However, SR's electrophysiological properties and druggability research are relatively inadequate, which limits the development of SR as an antiarrhythmic candidate. PURPOSE To facilitate the development process of SR as an antiarrhythmic candidate, we performed integrated studies on the electrophysiological properties of SR in vitro and ex vivo to gain more comprehensive insights into the multi-ion channel blocking effects of SR, which provided the foundation for the further drugability studies in antiarrhythmic and safety studies. Firstly, SR's electrophysiological properties and antiarrhythmic potentials were recorded and assessed at the cell and tissue levels by comprehensively integrating the patch clamp with the Electrical and Optical Mapping systems. Subsequently, the antiarrhythmic effects of SR were validated by aconitine and ouabain-induced arrhythmia in vivo. Finally, the safety of SR as an antiarrhythmic candidate compound was evaluated based on the guidelines of the Comprehensive in Vitro Proarrhythmia Assay (CiPA). STUDY DESIGN The antiarrhythmic effect of SR was evaluated at the in vitro, ex vivo, and in vivo levels. METHODS Isolated primary cardiomyocytes and stable cell lines were prepared to explore the electrophysiologic properties of being a multiple ion-channel blocker in vitro by whole-cell patch clamp. Using electrical and optical mapping, the negative chronotropic effect of SR was determined in langendorff-perfused rat or guinea-pig hearts.The antiarrhythmic activity of SR was assessed by the ex vivo tachyarrhythmia models induced by left coronary artery ligation (LCAL) and isoproterenol (ISO). Canonical models of aconitine and ouabain-induced arrhythmia were used to verify the antiarrhythmic effects in vivo. Finally, the pro-arrhythmic risk of SR was detected in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes (hSCCMs) using a Microelectrode array (MEA). RESULTS Single-cell patch assay validated the multiple ion-channel blockers of SR in transient outward current potassium currents (Ito), l-type calcium currents (ICa-l), and rapid activation delayed rectifier potassium currents (IKr). SR ex vivo depressed heart rates (HR) and ventricular conduction velocity (CV) and prolonged Q-T intervals in a concentration-dependent manner. Consistent with the changes in HRs, SR extended the active time of hearts and increased the action potential duration measured at 90% repolarization (APD90). SR could also significantly lengthen the onset time and curtail the duration of spontaneous ventricular tachycardia (VT) in the ex vivo arrhythmic model induced by LCAL. Meanwhile, SR could also significantly upregulate the programmed electrical stimulation (PES) frequency after the ISO challenge in forming electrical alternans and re-entrant excitation. Furthermore, SR exerted antiarrhythmic effects in the tachyarrhythmia models induced by aconitine and ouabain in vivo. Notably, the pro-arrhythmic risk of SR was shallow for a moderate inhibition of the human ether-à-go-go-related gene (hERG) channel. Moreover, SR prolonged field potential duration (FPDc) of hSCCMs in a concentration-dependent manner without early after depolarization (EAD) and arrhythmia occurrence. CONCLUSION Our results indicated that SR manifested as a multiple ion-channel blocker in the electrophysiological properties and exerts antiarrhythmic effects ex vivo and in vivo. Meanwhile, due to the low pro-arrhythmic risk in the hERG inhibition assay and the induction of EAD, SR has great potential as a leading candidate in the treatment of ventricular tachyarrhythmia.
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Affiliation(s)
- Tao Song
- College of Integrated Chinese and Western Medicine, Hebei University of Chinese Medicine, Shijiazhuang 050035, China
| | - Yuanyuan Hao
- College of Integrated Chinese and Western Medicine, Hebei University of Chinese Medicine, Shijiazhuang 050035, China; New Drug Evaluation Center, Shijiazhuang Yiling Pharmaceutical Co., Ltd, Shijiazhuang 050035, China
| | - Mingye Wang
- College of Integrated Chinese and Western Medicine, Hebei University of Chinese Medicine, Shijiazhuang 050035, China
| | - Tongtong Li
- College of Integrated Chinese and Western Medicine, Hebei University of Chinese Medicine, Shijiazhuang 050035, China
| | - Chi Zhao
- Hebei Medical University, No. 361, East Zhongshan Road, Shijiazhuang, Hebei 050017, China
| | - Jiajia Li
- Department of Pharmacy, The Fourth Hospital of Shijiazhuang, No.16, the North of Tangu street, Shijiazhuang, Hebei 050031, China
| | - Yunlong Hou
- College of Integrated Chinese and Western Medicine, Hebei University of Chinese Medicine, Shijiazhuang 050035, China; New Drug Evaluation Center, Shijiazhuang Yiling Pharmaceutical Co., Ltd, Shijiazhuang 050035, China; Shijiazhuang Compound Traditional Chinese Medicine Technology Innovation Center, Shijiazhuang 050035, China.
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Gottlieb LA, Coronel R, Dekker LRC. Reduction in atrial and pulmonary vein stretch as a therapeutic target for prevention of atrial fibrillation. Heart Rhythm 2023; 20:291-298. [PMID: 36265692 DOI: 10.1016/j.hrthm.2022.10.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 09/21/2022] [Accepted: 10/05/2022] [Indexed: 11/04/2022]
Abstract
Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with increased mortality. Heart failure, hypertension, valvular disease, and obstructive sleep apnea are risk factors for incident AF. A common characteristic of these diseases is that they increase atrial wall stretch. Multiple experimental studies confirm a proarrhythmic effect of atrial stretch. Conversely, a reduction in stretch is antiarrhythmic. A therapeutic target for AF, therefore, lies in local reduction of atrial stretch. This review focuses on atrial stretch and its clinical associations in patients with AF and its downstream effects on electrophysiology. We discuss the possible application of targeted atrial stretch reduction in AF prevention. We conclude that a reduction in local atrial stretch should be considered an essential element in rhythm control.
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Affiliation(s)
- Lisa A Gottlieb
- Department of Cardiology, University Hospital Copenhagen - Bispebjerg, Copenhagen, Denmark; AUMC, location Academic Medical Centre, Department of Experimental Cardiology, Amsterdam, The Netherlands; IHU Liryc, Electrophysiology and Heart Modeling Institute, University of Bordeaux, Bordeaux, France
| | - Ruben Coronel
- AUMC, location Academic Medical Centre, Department of Experimental Cardiology, Amsterdam, The Netherlands; IHU Liryc, Electrophysiology and Heart Modeling Institute, University of Bordeaux, Bordeaux, France.
| | - Lukas R C Dekker
- Department of Biomedical Engineering, Eindhoven University of Technology, The Netherlands
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Xing C, Bao L, Li W, Fan H. Progress on role of ion channels of cardiac fibroblasts in fibrosis. Front Physiol 2023; 14:1138306. [PMID: 36969589 PMCID: PMC10033868 DOI: 10.3389/fphys.2023.1138306] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/27/2023] [Indexed: 03/29/2023] Open
Abstract
Cardiac fibrosis is defined as excessive deposition of extracellular matrix (ECM) in pathological conditions. Cardiac fibroblasts (CFs) activated by injury or inflammation differentiate into myofibroblasts (MFs) with secretory and contractile functions. In the fibrotic heart, MFs produce ECM which is composed mainly of collagen and is initially involved in maintaining tissue integrity. However, persistent fibrosis disrupts the coordination of excitatory contractile coupling, leading to systolic and diastolic dysfunction, and ultimately heart failure. Numerous studies have demonstrated that both voltage- and non-voltage-gated ion channels alter intracellular ion levels and cellular activity, contributing to myofibroblast proliferation, contraction, and secretory function. However, an effective treatment strategy for myocardial fibrosis has not been established. Therefore, this review describes the progress made in research related to transient receptor potential (TRP) channels, Piezo1, Ca2+ release-activated Ca2+ (CRAC) channels, voltage-gated Ca2+ channels (VGCCs), sodium channels, and potassium channels in myocardial fibroblasts with the aim of providing new ideas for treating myocardial fibrosis.
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Li XT. Beneficial effects of carvedilol modulating potassium channels on the control of glucose. Biomed Pharmacother 2022; 150:113057. [PMID: 35658228 DOI: 10.1016/j.biopha.2022.113057] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/19/2022] [Accepted: 04/26/2022] [Indexed: 11/25/2022] Open
Abstract
The increased prevalence of hypertensive patients with type 2 diabetes mellitus (T2DM) is evident worldwide, leading to a higher risk of cardiovascular disease onset, which is substantially associated with disabilities and mortality in the clinic. In order to achieve the satisfyingly clinical outcomes and prognosis, the comprehensive therapies have been conducted with a beneficial effect on both blood pressure and glucose homeostasis, and clinical trials reveal that some kind of antihypertensive drugs such as angiotensin converting enzyme inhibitors (ACE-I) may, at least in part, meet the dual requirement during the disease management. As a nonselective β-blocker, carvedilol is employed for treating many cardiovascular diseases in clinical practice, including hypertension, angina pectoris and heart failure, and also exhibit the effectiveness for glycemic control and insulin resistance. Apart from alleviating sympathetic nervous system activity, several causes, such as lowering oxygen reactive species, may contribute to the effects of carvedilol on controlling plasma glucose levels, suggesting a feature of this drug having multiple targets. Interestingly, numerous distinct K+ channels expressed in pancreatic β-cells and peripheral insulin-sensitive tissues, which play a sentential role in glucose metabolism, are subjected to extensive modulation of carvdilol, establishing a linkage between K+ channels and drug's effects on the control of glucose. A variety of evidence shows that the impact of carvedilol on different K+ channels, including Kv, KAch, KATP and K2 P, can lead to positive influences for glucose homeostasis, contributing to its clinical beneficial effectiveness in treatment of hypertensive patients with T2DM. This review focus on the control of plasma glucose conferred by carvedilol modulation on K+ channels, providing the novel mechanistic explanation for drug's actions.
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Affiliation(s)
- Xian-Tao Li
- Department of Neuroscience, South-Central University for Nationalities, Wuhan 430074, China; School of Medicine, Guizhou University, Guiyang 550025, China.
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9
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Mayar S, Memarpoor-Yazdi M, Makky A, Eslami Sarokhalil R, D'Avanzo N. Direct Regulation of Hyperpolarization-Activated Cyclic-Nucleotide Gated (HCN1) Channels by Cannabinoids. Front Mol Neurosci 2022; 15:848540. [PMID: 35465092 PMCID: PMC9019169 DOI: 10.3389/fnmol.2022.848540] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 02/21/2022] [Indexed: 11/24/2022] Open
Abstract
Cannabinoids are a broad class of molecules that act primarily on neurons, affecting pain sensation, appetite, mood, learning, and memory. In addition to interacting with specific cannabinoid receptors (CBRs), cannabinoids can directly modulate the function of various ion channels. Here, we examine whether cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), the most prevalent phytocannabinoids in Cannabis sativa, can regulate the function of hyperpolarization-activated cyclic-nucleotide-gated (HCN1) channels independently of CBRs. HCN1 channels were expressed in Xenopus oocytes since they do not express CBRs, and the effects of cannabinoid treatment on HCN1 currents were examined by a two-electrode voltage clamp. We observe opposing effects of CBD and THC on HCN1 current, with CBD acting to stimulate HCN1 function, while THC inhibited current. These effects persist in HCN1 channels lacking the cyclic-nucleotide binding domain (HCN1ΔCNBD). However, changes to membrane fluidity, examined by treating cells with TX-100, inhibited HCN1 current had more pronounced effects on the voltage-dependence and kinetics of activation than THC, suggesting this is not the primary mechanism of HCN1 regulation by cannabinoids. Our findings may contribute to the overall understanding of how cannabinoids may act as promising therapeutic molecules for the treatment of several neurological disorders in which HCN function is disturbed.
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10
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Two-Pore-Domain Potassium (K 2P-) Channels: Cardiac Expression Patterns and Disease-Specific Remodelling Processes. Cells 2021; 10:cells10112914. [PMID: 34831137 PMCID: PMC8616229 DOI: 10.3390/cells10112914] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/18/2021] [Accepted: 10/22/2021] [Indexed: 12/23/2022] Open
Abstract
Two-pore-domain potassium (K2P-) channels conduct outward K+ currents that maintain the resting membrane potential and modulate action potential repolarization. Members of the K2P channel family are widely expressed among different human cell types and organs where they were shown to regulate important physiological processes. Their functional activity is controlled by a broad variety of different stimuli, like pH level, temperature, and mechanical stress but also by the presence of lipids or pharmacological agents. In patients suffering from cardiovascular diseases, alterations in K2P-channel expression and function have been observed, suggesting functional significance and a potential therapeutic role of these ion channels. For example, upregulation of atrial specific K2P3.1 (TASK-1) currents in atrial fibrillation (AF) patients was shown to contribute to atrial action potential duration shortening, a key feature of AF-associated atrial electrical remodelling. Therefore, targeting K2P3.1 (TASK-1) channels might constitute an intriguing strategy for AF treatment. Further, mechanoactive K2P2.1 (TREK-1) currents have been implicated in the development of cardiac hypertrophy, cardiac fibrosis and heart failure. Cardiovascular expression of other K2P channels has been described, functional evidence in cardiac tissue however remains sparse. In the present review, expression, function, and regulation of cardiovascular K2P channels are summarized and compared among different species. Remodelling patterns, observed in disease models are discussed and compared to findings from clinical patients to assess the therapeutic potential of K2P channels.
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11
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Wang Y, Fu Z, Ma Z, Li N, Shang H. Bepridil, a class IV antiarrhythmic agent, can block the TREK-1 potassium channel. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1123. [PMID: 34430564 PMCID: PMC8350656 DOI: 10.21037/atm-20-7971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 05/17/2021] [Indexed: 11/24/2022]
Abstract
Background The TWIK-related potassium channel (TREK-1) can be regulated by different stimuli. However, it is not clear whether some antiarrhythmics affect the activity of TREK-1. In the present study, the effect of bepridil on the TREK-1 currents is investigated. Methods In a TREK-1 stably-expressed HEK-293 cell line (HEK-TREK-1), U251MG cells, and isolated mouse ventricular myocytes, the TREK-1 current and action potentials were recorded by the patch-clamp technique. The standard voltage protocol was a 200 ms constant potential at 20 mV, followed bya 500 ms ramp from –90 to +20 mV (HEK-TREK-1) or +80 mV (U251MG cells and myocytes) every 10 s. The currents at +20 mV or +80 mV were used for analysis. The docking study of bepridil’s binding model in the TREK-1 channel was performed using the Swissdock web service. Results In HEK-TREK-1 cells, BL1249 induced a significantly large outwardly rectifying current with similar baseline TREK-1 current characteristic, with a reversal potential (−70 mV). The concentration of half-maximal activation (EC50) of BL1249 was 3.45 µM. However, bepridil decreased the baseline TREK-1 currents, with a concentration of half-maximal inhibition (IC50) 0.59 µM and a Hill coefficient of 1.1. Also, bepridil inhibited BL1249-activated TREK-1 currents, with an IC50 4.08 µM and a Hill coefficient of 3.22. The outside-out patch-clamp confirmed bepridil inhibited BL1249-activated TREK-1 currents. In U251MG cells and myocytes, BL1249 activated outwardly rectifying endogenous TREK-1 currents, which could be inhibited by bepridil. BL1249 (10 µM) could decrease the peak value and reduce the duration of the action potential. Bepridil (10 µM) prolonged the duration of action potential of myocytes. The docking study revealed that bepridil might affect the K+ pore domain and the M4 modulator pocket. Conclusions Bepridil may be a blocker for the TREK-1K+channel at a clinically therapeutic concentration, providing a new mechanism of TREK-1 regulation and bepridil's antiarrhythmic effect.
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Affiliation(s)
- Ying Wang
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Department of Cardiology, Qilu Hospital, Shandong University, Jinan, China
| | - Zhijie Fu
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Department of Cardiology, Qilu Hospital, Shandong University, Jinan, China.,Department of Otorhinolaryngology, the First Affiliated Hospital of Shandong First Medical University, Jinan, China
| | - Zhiyong Ma
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Department of Cardiology, Qilu Hospital, Shandong University, Jinan, China
| | - Na Li
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Department of Cardiology, Qilu Hospital, Shandong University, Jinan, China
| | - Hong Shang
- Key Laboratory of Cardiovascular Proteomics of Shandong Province, Department of Geriatrics, Qilu Hospital, Shandong University, Jinan, China
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12
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Mathie A, Veale EL, Golluscio A, Holden RG, Walsh Y. Pharmacological Approaches to Studying Potassium Channels. Handb Exp Pharmacol 2021; 267:83-111. [PMID: 34195873 DOI: 10.1007/164_2021_502] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this review, we consider the pharmacology of potassium channels from the perspective of these channels as therapeutic targets. Firstly, we describe the three main families of potassium channels in humans and disease states where they are implicated. Secondly, we describe the existing therapeutic agents which act on potassium channels and outline why these channels represent an under-exploited therapeutic target with potential for future drug development. Thirdly, we consider the evidence desired in order to embark on a drug discovery programme targeting a particular potassium channel. We have chosen two "case studies": activators of the two-pore domain potassium (K2P) channel TREK-2 (K2P10.1), for the treatment of pain and inhibitors of the voltage-gated potassium channel KV1.3, for use in autoimmune diseases such as multiple sclerosis. We describe the evidence base to suggest why these are viable therapeutic targets. Finally, we detail the main technical approaches available to characterise the pharmacology of potassium channels and identify novel regulatory compounds. We draw particular attention to the Comprehensive in vitro Proarrhythmia Assay initiative (CiPA, https://cipaproject.org ) project for cardiac safety, as an example of what might be both desirable and possible in the future, for ion channel regulator discovery projects.
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Affiliation(s)
- Alistair Mathie
- Medway School of Pharmacy, University of Kent, Kent, UK. .,Medway School of Pharmacy, University of Greenwich, London, UK. .,School of Engineering, Arts, Science and Technology, University of Suffolk, Ipswich, UK.
| | - Emma L Veale
- Medway School of Pharmacy, University of Kent, Kent, UK.,Medway School of Pharmacy, University of Greenwich, London, UK
| | - Alessia Golluscio
- Medway School of Pharmacy, University of Kent, Kent, UK.,Medway School of Pharmacy, University of Greenwich, London, UK
| | - Robyn G Holden
- Medway School of Pharmacy, University of Kent, Kent, UK.,Medway School of Pharmacy, University of Greenwich, London, UK
| | - Yvonne Walsh
- Medway School of Pharmacy, University of Kent, Kent, UK.,Medway School of Pharmacy, University of Greenwich, London, UK
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13
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Walsh Y, Leach M, Veale EL, Mathie A. Block of TREK and TRESK K2P channels by lamotrigine and two derivatives sipatrigine and CEN-092. Biochem Biophys Rep 2021; 26:101021. [PMID: 34041373 PMCID: PMC8144350 DOI: 10.1016/j.bbrep.2021.101021] [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: 03/26/2021] [Revised: 04/29/2021] [Accepted: 05/07/2021] [Indexed: 11/30/2022] Open
Abstract
TREK and TRESK K2P channels are widely expressed in the nervous system, particularly in sensory neurons, where they regulate neuronal excitability. In this study, using whole-cell patch-clamp electrophysiology, we characterise the inhibitory effect of the anticonvulsant lamotrigine and two derivatives, sipatrigine and 3,5-diamino-6-(3,5-bistrifluoromethylphenyl)-1,2,4-triazine (CEN-092) on these channels. Sipatrigine was found to be a more effective inhibitor than lamotrigine of TREK-1, TREK-2 and TRESK channels. Sipatrigine was slightly more potent on TREK-1 channels (EC50 = 16 μM) than TRESK (EC50 = 34 μM) whereas lamotrigine was equally effective on TREK-1 and TRESK. Sipatrigine was less effective on a short isoform of TREK-2, suggesting the N terminus of the channel is important for both inhibition and subsequent over-recovery. Inhibition of TREK-1 and TREK-2 channels by sipatrigine was reduced by mutation of a leucine residue associated with the norfluoxetine binding site on these channels (L289A and L320A on TREK-1 and TREK-2, respectively) but these did not affect inhibition by lamotrigine. Inhibition of TRESK by sipatrigine and lamotrigine was attenuated by mutation of bulky phenylalanine residues (F145A and F352A) in the inner pore helix. However, phosphorylation mutations did not alter the effect of sipatrigine. CEN-092 was a more effective inhibitor of TRESK channels than TREK-1 channels. It is concluded that lamotrigine, sipatrigine and CEN-092 are all inhibitors of TREK and TRESK channels but do not greatly discriminate between them. The actions of these compounds may contribute to their current and potential use in the treatment of pain and depression. Lamotrigine blocks TREK and TRESK potassium channels at clinical concentrations. Sipatrigine is more effective than lamotrigine at blocking TREK and TRESK channels. Mutation of norfluoxetine binding site on TREK channels attenuates sipatrigine block. Residues in the inner pore region of TRESK channels regulate sipatrigine block. The novel lamotrigine derivative, CEN-092, blocks TRESK channels.
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Affiliation(s)
- Yvonne Walsh
- Medway School of Pharmacy, University of Kent and University of Greenwich, Central Avenue, Chatham Maritime, ME4 4TB, UK
- University of Greenwich, Central Avenue, Chatham Maritime, ME4 4TB, UK
| | - Michael Leach
- University of Greenwich, Central Avenue, Chatham Maritime, ME4 4TB, UK
| | - Emma L. Veale
- Medway School of Pharmacy, University of Kent and University of Greenwich, Central Avenue, Chatham Maritime, ME4 4TB, UK
| | - Alistair Mathie
- Medway School of Pharmacy, University of Kent and University of Greenwich, Central Avenue, Chatham Maritime, ME4 4TB, UK
- School of Engineering, Arts, Science and Technology, University of Suffolk, Waterfront Building, Neptune Quay, Ipswich, IP4 1QJ, UK
- Corresponding author.Medway School of Pharmacy, University of Kent and University of Greenwich, Central Avenue, Chatham Maritime, ME4 4TB, UK.
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14
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Mukherjee S, Sikdar SK. Intracellular activation of full-length human TREK-1 channel by hypoxia, high lactate, and low pH denotes polymodal integration by ischemic factors. Pflugers Arch 2020; 473:167-183. [PMID: 33025137 DOI: 10.1007/s00424-020-02471-5] [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: 09/01/2020] [Revised: 09/18/2020] [Accepted: 09/30/2020] [Indexed: 10/23/2022]
Abstract
TREK-1, a two-pore domain potassium channel, responds to ischemic levels of intracellular lactate and acidic pH to provide neuroprotection. There are two splice variants of hTREK1: the shorter splice variant having a shorter N-terminus compared with the full-length hTREK1 with similar C-terminus sequence that is widely expressed in the brain. The shorter variant was reported to be irresponsive to hypoxia-a condition attributed to ischemia, which has put the neuroprotective role of hTREK-1 channel into question. Since interaction between N- and C-terminus of different ion channels shapes their gating, we re-examined the sensitivity of the full-length as well as the shorter hTREK-1 channel to intracellular hypoxia along with lactate. Single-channel data obtained from the excised inside-out patches of the full-length channel expressed in HEK293 cells indicated an increase in activity as opposed to a decrease in activity in the shorter isoform. However, both the isoforms showed an increase in activity under combined hypoxia, 20mM lactate, and low pH 6 condition, albeit with subtle differences in their individual actions, confirming the neuroprotective role played by hTREK-1 irrespective of the differences in the N-terminus among the splice variants. Furthermore, E321A mutant that disrupts the interaction of the C-terminus with the membrane showed a decrease in activity with hypoxia indicating the importance of the C-terminus in the hypoxic response of the full-length hTREK-1. We propose an increase in activity of both the splice variants of hTREK-1 in combined hypoxia, high lactate, and low pH conditions typically associated with ischemia provides neuroprotection.
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Affiliation(s)
- Sourajit Mukherjee
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, 560012, India
| | - Sujit Kumar Sikdar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, 560012, India.
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15
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Mathie A, Veale EL, Cunningham KP, Holden RG, Wright PD. Two-Pore Domain Potassium Channels as Drug Targets: Anesthesia and Beyond. Annu Rev Pharmacol Toxicol 2020; 61:401-420. [PMID: 32679007 DOI: 10.1146/annurev-pharmtox-030920-111536] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Two-pore domain potassium (K2P) channels stabilize the resting membrane potential of both excitable and nonexcitable cells and, as such, are important regulators of cell activity. There are many conditions where pharmacological regulation of K2P channel activity would be of therapeutic benefit, including, but not limited to, atrial fibrillation, respiratory depression, pulmonary hypertension, neuropathic pain, migraine, depression, and some forms of cancer. Up until now, few if any selective pharmacological regulators of K2P channels have been available. However, recent publications of solved structures with small-molecule activators and inhibitors bound to TREK-1, TREK-2, and TASK-1 K2P channels have given insight into the pharmacophore requirements for compound binding to these sites. Together with the increasing availability of a number of novel, active, small-molecule compounds from K2P channel screening programs, these advances have opened up the possibility of rational activator and inhibitor design to selectively target K2P channels.
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Affiliation(s)
- Alistair Mathie
- Medway School of Pharmacy, University of Greenwich and University of Kent, Kent ME4 4TB, United Kingdom;
| | - Emma L Veale
- Medway School of Pharmacy, University of Greenwich and University of Kent, Kent ME4 4TB, United Kingdom;
| | - Kevin P Cunningham
- Wolfson Centre for Age-Related Diseases, King's College London, London SE1 1UL, United Kingdom
| | - Robyn G Holden
- Medway School of Pharmacy, University of Greenwich and University of Kent, Kent ME4 4TB, United Kingdom;
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16
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Wiedmann F, Rinné S, Donner B, Decher N, Katus HA, Schmidt C. Mechanosensitive TREK-1 two-pore-domain potassium (K 2P) channels in the cardiovascular system. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 159:126-135. [PMID: 32553901 DOI: 10.1016/j.pbiomolbio.2020.05.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/01/2020] [Accepted: 05/11/2020] [Indexed: 12/12/2022]
Abstract
TWIK-related K+ channel (TREK-1) two-pore-domain potassium (K2P) channels mediate background potassium currents and regulate cellular excitability in many different types of cells. Their functional activity is controlled by a broad variety of different physiological stimuli, such as temperature, extracellular or intracellular pH, lipids and mechanical stress. By linking cellular excitability to mechanical stress, TREK-1 currents might be important to mediate parts of the mechanoelectrical feedback described in the heart. Furthermore, TREK-1 currents might contribute to the dysregulation of excitability in the heart in pathophysiological situations, such as those caused by abnormal stretch or ischaemia-associated cell swelling, thereby contributing to arrhythmogenesis. In this review, we focus on the functional role of TREK-1 in the heart and its putative contribution to cardiac mechanoelectrical coupling. Its cardiac expression among different species is discussed, alongside with functional evidence for TREK-1 currents in cardiomyocytes. In addition, evidence for the involvement of TREK-1 currents in different cardiac arrhythmias, such as atrial fibrillation or ventricular tachycardia, is summarized. Furthermore, the role of TREK-1 and its interaction partners in the regulation of the cardiac heart rate is reviewed. Finally, we focus on the significance of TREK-1 in the development of cardiac hypertrophy, cardiac fibrosis and heart failure.
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Affiliation(s)
- Felix Wiedmann
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - Philipps-University Marburg, Marburg, Germany
| | - Birgit Donner
- Pediatric Cardiology, University Children's Hospital Basel (UKBB), University of Basel, Basel, Switzerland
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - Philipps-University Marburg, Marburg, Germany
| | - Hugo A Katus
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany
| | - Constanze Schmidt
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany.
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17
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Translating Translation to Mechanisms of Cardiac Hypertrophy. J Cardiovasc Dev Dis 2020; 7:jcdd7010009. [PMID: 32164190 PMCID: PMC7151157 DOI: 10.3390/jcdd7010009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 03/02/2020] [Accepted: 03/05/2020] [Indexed: 12/18/2022] Open
Abstract
Cardiac hypertrophy in response to chronic pathological stress is a common feature occurring with many forms of heart disease. This pathological hypertrophic growth increases the risk for arrhythmias and subsequent heart failure. While several factors promoting cardiac hypertrophy are known, the molecular mechanisms governing the progression to heart failure are incompletely understood. Recent studies on altered translational regulation during pathological cardiac hypertrophy are contributing to our understanding of disease progression. In this brief review, we describe how the translational machinery is modulated for enhanced global and transcript selective protein synthesis, and how alternative modes of translation contribute to the disease state. Attempts at controlling translational output through targeting of mTOR and its regulatory components are detailed, as well as recently emerging targets for pre-clinical investigation.
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18
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Wright PD, McCoull D, Walsh Y, Large JM, Hadrys BW, Gaurilcikaite E, Byrom L, Veale EL, Jerman J, Mathie A. Pranlukast is a novel small molecule activator of the two-pore domain potassium channel TREK2. Biochem Biophys Res Commun 2019; 520:35-40. [DOI: 10.1016/j.bbrc.2019.09.093] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 09/21/2019] [Indexed: 11/29/2022]
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19
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N-Glycosylation of TREK-1/hK 2P2.1 Two-Pore-Domain Potassium (K 2P) Channels. Int J Mol Sci 2019; 20:ijms20205193. [PMID: 31635148 PMCID: PMC6829520 DOI: 10.3390/ijms20205193] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 10/15/2019] [Accepted: 10/18/2019] [Indexed: 01/11/2023] Open
Abstract
Mechanosensitive hTREK-1 two-pore-domain potassium (hK2P2.1) channels give rise to background currents that control cellular excitability. Recently, TREK-1 currents have been linked to the regulation of cardiac rhythm as well as to hypertrophy and fibrosis. Even though the pharmacological and biophysical characteristics of hTREK-1 channels have been widely studied, relatively little is known about their posttranslational modifications. This study aimed to evaluate whether hTREK-1 channels are N-glycosylated and whether glycosylation may affect channel functionality. Following pharmacological inhibition of N-glycosylation, enzymatic digestion or mutagenesis, immunoblots of Xenopus laevis oocytes and HEK-293T cell lysates were used to assess electrophoretic mobility. Two-electrode voltage clamp measurements were employed to study channel function. TREK-1 channel subunits undergo N-glycosylation at asparagine residues 110 and 134. The presence of sugar moieties at these two sites increases channel function. Detection of glycosylation-deficient mutant channels in surface fractions and recordings of macroscopic potassium currents mediated by these subunits demonstrated that nonglycosylated hTREK-1 channel subunits are able to reach the cell surface in general but with seemingly reduced efficiency compared to glycosylated subunits. These findings extend our understanding of the regulation of hTREK-1 currents by posttranslational modifications and provide novel insights into how altered ion channel glycosylation may promote arrhythmogenesis.
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Staudacher I, Seehausen S, Illg C, Lugenbiel P, Schweizer PA, Katus HA, Thomas D. Cardiac K2P13.1 (THIK-1) two-pore-domain K+ channels: Pharmacological regulation and remodeling in atrial fibrillation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 144:128-138. [DOI: 10.1016/j.pbiomolbio.2018.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/28/2018] [Accepted: 06/25/2018] [Indexed: 01/30/2023]
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21
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Staudacher I, Illg C, Gierten J, Seehausen S, Schweizer PA, Katus HA, Thomas D. Identification and functional characterization of zebrafish K 2P 17.1 (TASK-4, TALK-2) two-pore-domain K + channels. Eur J Pharmacol 2018; 831:94-102. [DOI: 10.1016/j.ejphar.2018.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/04/2018] [Accepted: 05/08/2018] [Indexed: 12/12/2022]
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22
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Schmidt C, Wiedmann F, Gaubatz AR, Ratte A, Katus HA, Thomas D. New Targets for Old Drugs: Cardiac Glycosides Inhibit Atrial-Specific K 2P3.1 (TASK-1) Channels. J Pharmacol Exp Ther 2018; 365:614-623. [PMID: 29643254 DOI: 10.1124/jpet.118.247692] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/04/2018] [Indexed: 02/06/2023] Open
Abstract
Cardiac glycosides have been used in the treatment of arrhythmias for more than 200 years. Two-pore-domain (K2P) potassium channels regulate cardiac action potential repolarization. Recently, K2P3.1 [tandem of P domains in a weak inward rectifying K+ channel (TWIK)-related acid-sensitive K+ channel (TASK)-1] has been implicated in atrial fibrillation pathophysiology and was suggested as an atrial-selective antiarrhythmic drug target. We hypothesized that blockade of cardiac K2P channels contributes to the mechanism of action of digitoxin and digoxin. All functional human K2P channels were screened for interactions with cardiac glycosides. Human K2P channel subunits were expressed in Xenopus laevis oocytes, and voltage clamp electrophysiology was used to record K+ currents. Digitoxin significantly inhibited K2P3.1 and K2P16.1 channels. By contrast, digoxin displayed isolated inhibitory effects on K2P3.1. K2P3.1 outward currents were reduced by 80% (digitoxin, 1 Hz) and 78% (digoxin, 1 Hz). Digitoxin inhibited K2P3.1 currents with an IC50 value of 7.4 µM. Outward rectification properties of the channel were not affected. Mutagenesis studies revealed that amino acid residues located at the cytoplasmic site of the K2P3.1 channel pore form parts of a molecular binding site for cardiac glycosides. In conclusion, cardiac glycosides target human K2P channels. The antiarrhythmic significance of repolarizing atrial K2P3.1 current block by digoxin and digitoxin requires validation in translational and clinical studies.
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Affiliation(s)
- Constanze Schmidt
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| | - Felix Wiedmann
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| | - Anne-Rike Gaubatz
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| | - Antonius Ratte
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| | - Hugo A Katus
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| | - Dierk Thomas
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
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23
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Täger J, Kohl S, Birch DG, Wheaton DKH, Wissinger B, Reuter P. An early nonsense mutation facilitates the expression of a short isoform of CNGA3 by alternative translation initiation. Exp Eye Res 2018; 171:48-53. [PMID: 29499183 DOI: 10.1016/j.exer.2018.02.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 02/26/2018] [Accepted: 02/26/2018] [Indexed: 11/24/2022]
Abstract
The cyclic nucleotide-gated (CNG) channel - composed of CNGA3 and CNGB3 subunits - mediates the influx of cations in cone photoreceptors after light stimulation and thus is a key element in cone phototransduction. Mutations in CNGA3 and CNGB3 are associated with achromatopsia, a rare autosomal recessive retinal disorder. Here, we demonstrate that the presence of an early nonsense mutation in CNGA3 induces the usage of a downstream alternative translation initiation site giving rise to a short CNGA3 isoform. The expression of this short isoform was verified by Western blot analysis and DAB staining of HEK293 cells and cone photoreceptor-like 661W cells expressing CNGA3-GST fusion constructs. Functionality of the short isoform was confirmed by a cellular calcium influx assay. Furthermore, patients carrying an early nonsense mutation were analyzed for residual cone photoreceptor function in order to identify a potential role of the short isoform to modify the clinical outcome in achromatopsia patients. Yet the results suggest that the short isoform is not able to compensate for the loss of the long isoform leaving the biological role of this variant unclear.
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Affiliation(s)
- Joachim Täger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Graduate School of Cellular and Molecular Neuroscience, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | | | | | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
| | - Peggy Reuter
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
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24
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Just S, Chenard BL, Ceci A, Strassmaier T, Chong JA, Blair NT, Gallaschun RJ, del Camino D, Cantin S, D’Amours M, Eickmeier C, Fanger CM, Hecker C, Hessler DP, Hengerer B, Kroker KS, Malekiani S, Mihalek R, McLaughlin J, Rast G, Witek J, Sauer A, Pryce CR, Moran MM. Treatment with HC-070, a potent inhibitor of TRPC4 and TRPC5, leads to anxiolytic and antidepressant effects in mice. PLoS One 2018; 13:e0191225. [PMID: 29385160 PMCID: PMC5791972 DOI: 10.1371/journal.pone.0191225] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 12/30/2017] [Indexed: 12/28/2022] Open
Abstract
Background Forty million adults in the US suffer from anxiety disorders, making these the most common forms of mental illness. Transient receptor potential channel canonical subfamily (TRPC) members 4 and 5 are non-selective cation channels highly expressed in regions of the cortex and amygdala, areas thought to be important in regulating anxiety. Previous work with null mice suggests that inhibition of TRPC4 and TRPC5 may have anxiolytic effects. HC-070 in vitro To assess the potential of TRPC4/5 inhibitors as an avenue for treatment, we invented a highly potent, small molecule antagonist of TRPC4 and TRPC5 which we call HC-070. HC-070 inhibits recombinant TRPC4 and TRPC5 homomultimers in heterologous expression systems with nanomolar potency. It also inhibits TRPC1/5 and TRPC1/4 heteromultimers with similar potency and reduces responses evoked by cholecystokinin tetrapeptide (CCK-4) in the amygdala. The compound is >400-fold selective over a wide range of molecular targets including ion channels, receptors, and kinases. HC-070 in vivo Upon oral dosing in mice, HC-070 achieves exposure levels in the brain and plasma deemed sufficient to test behavioral activity. Treatment with HC-070 attenuates the anxiogenic effect of CCK-4 in the elevated plus maze (EPM). The compound recapitulates the phenotype observed in both null TRPC4 and TRPC5 mice in a standard EPM. Anxiolytic and anti-depressant effects of HC-070 are also observed in pharmacological in vivo tests including marble burying, tail suspension and forced swim. Furthermore, HC-070 ameliorates the increased fear memory induced by chronic social stress. A careful evaluation of the pharmacokinetic-pharmacodynamic relationship reveals that substantial efficacy is observed at unbound brain levels similar to, or even lower than, the 50% inhibitory concentration (IC50) recorded in vitro, increasing confidence that the observed effects are indeed mediated by TRPC4 and/or TRPC5 inhibition. Together, this experimental data set introduces a novel, high quality, small molecule antagonist of TRPC4 and TRPC5 containing channels and supports the targeting of TRPC4 and TRPC5 channels as a new mechanism of action for the treatment of psychiatric symptoms.
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Affiliation(s)
- Stefan Just
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | | | - Angelo Ceci
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | | | - Jayhong A. Chong
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | | | | | - Donato del Camino
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Susan Cantin
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Marc D’Amours
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | | | | | - Carsten Hecker
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - David P. Hessler
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Bastian Hengerer
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Katja S. Kroker
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Sam Malekiani
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Robert Mihalek
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Joseph McLaughlin
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Georg Rast
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - JoAnn Witek
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Achim Sauer
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Christopher R. Pryce
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy & Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Magdalene M. Moran
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
- * E-mail:
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25
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Leithe E, Mesnil M, Aasen T. The connexin 43 C-terminus: A tail of many tales. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:48-64. [PMID: 28526583 DOI: 10.1016/j.bbamem.2017.05.008] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/10/2017] [Accepted: 05/12/2017] [Indexed: 10/19/2022]
Abstract
Connexins are chordate gap junction channel proteins that, by enabling direct communication between the cytosols of adjacent cells, create a unique cell signalling network. Gap junctional intercellular communication (GJIC) has important roles in controlling cell growth and differentiation and in tissue development and homeostasis. Moreover, several non-canonical connexin functions unrelated to GJIC have been discovered. Of the 21 members of the human connexin family, connexin 43 (Cx43) is the most widely expressed and studied. The long cytosolic C-terminus (CT) of Cx43 is subject to extensive post-translational modifications that modulate its intracellular trafficking and gap junction channel gating. Moreover, the Cx43 CT contains multiple domains involved in protein interactions that permit crosstalk between Cx43 and cytoskeletal and regulatory proteins. These domains endow Cx43 with the capacity to affect cell growth and differentiation independently of GJIC. Here, we review the current understanding of the regulation and unique functions of the Cx43 CT, both as an essential component of full-length Cx43 and as an independent signalling hub. We highlight the complex regulatory and signalling networks controlled by the Cx43 CT, including the extensive protein interactome that underlies both gap junction channel-dependent and -independent functions. We discuss these data in relation to the recent discovery of the direct translation of specific truncated forms of Cx43. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Edward Leithe
- Department of Molecular Oncology, Institute for Cancer Research, University of Oslo, NO-0424 Oslo, Norway; Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, NO-0424 Oslo, Norway
| | - Marc Mesnil
- STIM Laboratory ERL 7368 CNRS - Faculté des Sciences Fondamentales et Appliquées, Université de Poitiers, Poitiers 86073, France
| | - Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, 08035 Barcelona, Spain.
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26
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Schmidt C, Wiedmann F, Kallenberger SM, Ratte A, Schulte JS, Scholz B, Müller FU, Voigt N, Zafeiriou MP, Ehrlich JR, Tochtermann U, Veres G, Ruhparwar A, Karck M, Katus HA, Thomas D. Stretch-activated two-pore-domain (K 2P) potassium channels in the heart: Focus on atrial fibrillation and heart failure. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 130:233-243. [PMID: 28526353 DOI: 10.1016/j.pbiomolbio.2017.05.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/11/2017] [Accepted: 05/15/2017] [Indexed: 12/18/2022]
Abstract
Two-pore-domain potassium (K2P) channels modulate cellular excitability. The significance of stretch-activated cardiac K2P channels (K2P2.1, TREK-1, KCNK2; K2P4.1, TRAAK, KCNK4; K2P10.1, TREK-2, KCNK10) in heart disease has not been elucidated in detail. The aim of this work was to assess expression and remodeling of mechanosensitive K2P channels in atrial fibrillation (AF) and heart failure (HF) patients in comparison to murine models. Cardiac K2P channel levels were quantified in atrial (A) and ventricular (V) tissue obtained from patients undergoing open heart surgery. In addition, control mice and mouse models of AF (cAMP-response element modulator (CREM)-IbΔC-X transgenic animals) or HF (cardiac dysfunction induced by transverse aortic constriction, TAC) were employed. Human and murine KCNK2 displayed highest mRNA abundance among mechanosensitive members of the K2P channel family (V > A). Disease-associated K2P2.1 remodeling was studied in detail. In patients with impaired left ventricular function, atrial KCNK2 (K2P2.1) mRNA and protein expression was significantly reduced. In AF subjects, downregulation of atrial and ventricular KCNK2 (K2P2.1) mRNA and protein levels was observed. AF-associated suppression of atrial Kcnk2 (K2P2.1) mRNA and protein was recapitulated in CREM-transgenic mice. Ventricular Kcnk2 expression was not significantly altered in mouse models of disease. In conclusion, mechanosensitive K2P2.1 and K2P10.1 K+ channels are expressed throughout the heart. HF- and AF-associated downregulation of KCNK2 (K2P2.1) mRNA and protein levels suggest a mechanistic contribution to cardiac arrhythmogenesis.
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Affiliation(s)
- Constanze Schmidt
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg / Mannheim, University of Heidelberg, Germany
| | - Felix Wiedmann
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg / Mannheim, University of Heidelberg, Germany
| | - Stefan M Kallenberger
- Department for Bioinformatics and Functional Genomics, Division of Theoretical Bioinformatics, German Cancer Research Center (DKFZ), Institute for Pharmacy and Molecular Biotechnology (IPMB) and BioQuant, Heidelberg University, Heidelberg, Germany
| | - Antonius Ratte
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Jan S Schulte
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Beatrix Scholz
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Frank Ulrich Müller
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Niels Voigt
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Georg-August University Göttingen, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Germany
| | - Maria-Patapia Zafeiriou
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Georg-August University Göttingen, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Germany
| | - Joachim R Ehrlich
- Department of Cardiology, Internal Medicine III, Goethe University, Frankfurt, Germany; Department of Cardiology, St. Josefs-Hospital, Wiesbaden, Germany
| | - Ursula Tochtermann
- Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany
| | - Gábor Veres
- Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany
| | - Arjang Ruhparwar
- Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany
| | - Matthias Karck
- Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg / Mannheim, University of Heidelberg, Germany
| | - Dierk Thomas
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg / Mannheim, University of Heidelberg, Germany.
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27
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TREK-1 (K2P2.1) K+ channels are suppressed in patients with atrial fibrillation and heart failure and provide therapeutic targets for rhythm control. Basic Res Cardiol 2016; 112:8. [DOI: 10.1007/s00395-016-0597-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 12/12/2016] [Indexed: 12/16/2022]
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28
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Therapeutic targeting of two-pore-domain potassium (K(2P)) channels in the cardiovascular system. Clin Sci (Lond) 2016; 130:643-50. [PMID: 26993052 DOI: 10.1042/cs20150533] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The improvement of treatment strategies in cardiovascular medicine is an ongoing process that requires constant optimization. The ability of a therapeutic intervention to prevent cardiovascular pathology largely depends on its capacity to suppress the underlying mechanisms. Attenuation or reversal of disease-specific pathways has emerged as a promising paradigm, providing a mechanistic rationale for patient-tailored therapy. Two-pore-domain K(+) (K(2P)) channels conduct outward K(+) currents that stabilize the resting membrane potential and facilitate action potential repolarization. K(2P) expression in the cardiovascular system and polymodal K2P current regulation suggest functional significance and potential therapeutic roles of the channels. Recent work has focused primarily on K(2P)1.1 [tandem of pore domains in a weak inwardly rectifying K(+) channel (TWIK)-1], K(2P)2.1 [TWIK-related K(+) channel (TREK)-1], and K(2P)3.1 [TWIK-related acid-sensitive K(+) channel (TASK)-1] channels and their role in heart and vessels. K(2P) currents have been implicated in atrial and ventricular arrhythmogenesis and in setting the vascular tone. Furthermore, the association of genetic alterations in K(2P)3.1 channels with atrial fibrillation, cardiac conduction disorders and pulmonary arterial hypertension demonstrates the relevance of the channels in cardiovascular disease. The function, regulation and clinical significance of cardiovascular K(2P) channels are summarized in the present review, and therapeutic options are emphasized.
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29
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Hancox JC, James AF, Marrion NV, Zhang H, Thomas D. Novel ion channel targets in atrial fibrillation. Expert Opin Ther Targets 2016; 20:947-58. [DOI: 10.1517/14728222.2016.1159300] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Jules C. Hancox
- School of Physiology, Pharmacology and Neuroscience, University Walk, Bristol, UK
| | - Andrew F. James
- School of Physiology, Pharmacology and Neuroscience, University Walk, Bristol, UK
| | - Neil V. Marrion
- School of Physiology, Pharmacology and Neuroscience, University Walk, Bristol, UK
| | - Henggui Zhang
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom
| | - Dierk Thomas
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
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30
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Ohya S, Kito H, Hatano N, Muraki K. Recent advances in therapeutic strategies that focus on the regulation of ion channel expression. Pharmacol Ther 2016; 160:11-43. [PMID: 26896566 DOI: 10.1016/j.pharmthera.2016.02.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A number of different ion channel types are involved in cell signaling networks, and homeostatic regulatory mechanisms contribute to the control of ion channel expression. Profiling of global gene expression using microarray technology has recently provided novel insights into the molecular mechanisms underlying the homeostatic and pathological control of ion channel expression. It has demonstrated that the dysregulation of ion channel expression is associated with the pathogenesis of neural, cardiovascular, and immune diseases as well as cancers. In addition to the transcriptional, translational, and post-translational regulation of ion channels, potentially important evidence on the mechanisms controlling ion channel expression has recently been accumulated. The regulation of alternative pre-mRNA splicing is therefore a novel therapeutic strategy for the treatment of dominant-negative splicing disorders. Epigenetic modification plays a key role in various pathological conditions through the regulation of pluripotency genes. Inhibitors of pre-mRNA splicing and histone deacetyalase/methyltransferase have potential as potent therapeutic drugs for cancers and autoimmune and inflammatory diseases. Moreover, membrane-anchoring proteins, lysosomal and proteasomal degradation-related molecules, auxiliary subunits, and pharmacological agents alter the protein folding, membrane trafficking, and post-translational modifications of ion channels, and are linked to expression-defect channelopathies. In this review, we focused on recent insights into the transcriptional, spliceosomal, epigenetic, and proteasomal regulation of ion channel expression: Ca(2+) channels (TRPC/TRPV/TRPM/TRPA/Orai), K(+) channels (voltage-gated, KV/Ca(2+)-activated, KCa/two-pore domain, K2P/inward-rectifier, Kir), and Ca(2+)-activated Cl(-) channels (TMEM16A/TMEM16B). Furthermore, this review highlights expression of these ion channels in expression-defect channelopathies.
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Affiliation(s)
- Susumu Ohya
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Hiroaki Kito
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Noriyuki Hatano
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan
| | - Katsuhiko Muraki
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan.
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31
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Vivier D, Bennis K, Lesage F, Ducki S. Perspectives on the Two-Pore Domain Potassium Channel TREK-1 (TWIK-Related K(+) Channel 1). A Novel Therapeutic Target? J Med Chem 2015; 59:5149-57. [PMID: 26588045 DOI: 10.1021/acs.jmedchem.5b00671] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Potassium (K(+)) channels are membrane proteins expressed in most living cells that selectively control the flow of K(+) ions. More than 80 genes encode the K(+) channel subunits in the human genome. The TWIK-related K(+) channel (TREK-1) belongs to the two-pore domain K(+) channels (K2P) and displays various properties including sensitivity to physical (membrane stretch, acidosis, temperature) and chemical stimuli (signaling lipids, volatile anesthetics). The distribution of TREK-1 in the central nervous system, coupled with the physiological consequences of its opening and closing, leads to the emergence of this channel as an attractive therapeutic target. We review the TREK-1 channel, its structural and functional properties, and the pharmacological agents (agonists and antagonists) able to modulate its gating.
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Affiliation(s)
- Delphine Vivier
- Université Clermont Auvergne, ENSCCF, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand, France.,CNRS, UMR6296, ICCF, F-63171 Aubiere, France
| | - Khalil Bennis
- Université Clermont Auvergne, ENSCCF, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand, France.,CNRS, UMR6296, ICCF, F-63171 Aubiere, France
| | - Florian Lesage
- Labex ICST, Institut de Pharmacologie Moléculaire et Cellulaire, UMR CNRS 7275, Université de Nice Sophia Antipolis, F-06560 Valbonne, France
| | - Sylvie Ducki
- Université Clermont Auvergne, ENSCCF, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand, France.,CNRS, UMR6296, ICCF, F-63171 Aubiere, France
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32
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Endo K, Kurokawa N, Kito H, Nakakura S, Fujii M, Ohya S. Molecular identification of the dominant-negative, splicing isoform of the two-pore domain K(+) channel K(2P)5.1 in lymphoid cells and enhancement of its expression by splicing inhibition. Biochem Pharmacol 2015; 98:440-52. [PMID: 26475531 DOI: 10.1016/j.bcp.2015.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/01/2015] [Indexed: 12/20/2022]
Abstract
The two-pore domain background K(+) channel K2P5.1 is expected as a possible therapeutic target for autoimmune and inflammatory disorders and cancers because it plays an important role in maintaining the resting membrane potential and regulation of Ca(2+) signaling in T lymphocytes and cancer cells. However, the lack of selective K2P5.1 blockers has led to difficulties conducting experimental studies on this K(+) channel. We identified a novel splicing isoform of K2P5.1, K2P5.1B from the mammalian spleen, which lacked the N-terminus of full-length K2P5.1A. A co-immunoprecipitation assay using mice spleen lysates revealed an interaction between K2P5.1A and K2P5.1B in the cytoplasmic C-terminal domain. In a heterologous HEK293 expression system, K2P5.1B inhibited the trafficking of K2P5.1A to the plasma membrane. The alkaline pHe-induced hyperpolarizing response was significantly suppressed in K2P5.1B-transfected human leukemia K562 cells. Enhancement in cell proliferation by the overexpression of K2P5.1A in K562 was significantly prevented by the transfection of K2P5.1B. The spliceosome inhibitor pladienolide B significantly enhanced the relative expression of K2P5.1B in K562, resulting in decreases in the activity of K2P5.1A. K2P5.1B suppresses the function of the K2P5.1 K(+) channel in a dominant-negative manner, suggesting that the mRNA splicing mechanisms underlying the transcriptional regulation of K2P5.1B may be a new therapeutic strategy for autoimmune and inflammatory disorders and cancers.
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Affiliation(s)
- Kyoko Endo
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Natsumi Kurokawa
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Hiroaki Kito
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Sawa Nakakura
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Masanori Fujii
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Susumu Ohya
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
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33
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Abbott GW. Pharmacogenetic diversification by alternative translation initiation: background channels to the fore: Commentary on Kisselbach et al., Br J Pharmacol 171: 5182-5194. Br J Pharmacol 2015; 172:4591-4593. [DOI: 10.1111/bph.12630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 02/06/2014] [Indexed: 11/27/2022] Open
Affiliation(s)
- G W Abbott
- Bioelectricity Laboratory; Departments of Pharmacology and Physiology and Biophysics; School of Medicine; University of California; Irvine CA USA
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34
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Inhibition of cardiac two-pore-domain K+ (K2P) channels – an emerging antiarrhythmic concept. Eur J Pharmacol 2014; 738:250-5. [DOI: 10.1016/j.ejphar.2014.05.056] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 05/28/2014] [Indexed: 12/13/2022]
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35
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Seyler C, Schweizer PA, Zitron E, Katus HA, Thomas D. Vernakalant activates human cardiac K(2P)17.1 background K(+) channels. Biochem Biophys Res Commun 2014; 451:415-20. [PMID: 25108155 DOI: 10.1016/j.bbrc.2014.07.133] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 07/30/2014] [Indexed: 01/12/2023]
Abstract
Atrial fibrillation (AF) contributes significantly to cardiovascular morbidity and mortality. The growing epidemic is associated with cardiac repolarization abnormalities and requires the development of more effective antiarrhythmic strategies. Two-pore-domain K(+) channels stabilize the resting membrane potential and repolarize action potentials. Recently discovered K2P17.1 channels are expressed in human atrium and represent potential targets for AF therapy. However, cardiac electropharmacology of K2P17.1 channels remains to be investigated. This study was designed to elucidate human K2P17.1 regulation by antiarrhythmic drugs. Two-electrode voltage clamp and whole-cell patch clamp electrophysiology was used to record K2P currents from Xenopus oocytes and Chinese hamster ovary (CHO) cells. The class III antiarrhythmic compound vernakalant activated K2P17.1 currents in oocytes an in mammalian cells (EC50,CHO=40 μM) in frequency-dependent manner. K2P17.1 channel activation by vernakalant was specific among K2P channel family members. By contrast, vernakalant reduced K2P4.1 and K2P10.1 currents, in line with K2P2.1 blockade reported earlier. K2P17.1 open rectification characteristics and current-voltage relationships were not affected by vernakalant. The class I drug flecainide did not significantly modulate K2P currents. In conclusion, vernakalant activates K2P17.1 background potassium channels. Pharmacologic K2P channel activation by cardiovascular drugs has not been reported previously and may be employed for personalized rhythm control in patients with AF-associated reduction of K(+) channel function.
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Affiliation(s)
- Claudia Seyler
- Department of Cardiology, Medical University Hospital, Heidelberg, Im Neuenheimer Feld 410, D-69120 Heidelberg, Germany
| | - Patrick A Schweizer
- Department of Cardiology, Medical University Hospital, Heidelberg, Im Neuenheimer Feld 410, D-69120 Heidelberg, Germany
| | - Edgar Zitron
- Department of Cardiology, Medical University Hospital, Heidelberg, Im Neuenheimer Feld 410, D-69120 Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, Medical University Hospital, Heidelberg, Im Neuenheimer Feld 410, D-69120 Heidelberg, Germany
| | - Dierk Thomas
- Department of Cardiology, Medical University Hospital, Heidelberg, Im Neuenheimer Feld 410, D-69120 Heidelberg, Germany.
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