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Saint-Martin Willer A, Santos-Gomes J, Adão R, Brás-Silva C, Eyries M, Pérez-Vizcaino F, Capuano V, Montani D, Antigny F. Physiological and pathophysiological roles of the KCNK3 potassium channel in the pulmonary circulation and the heart. J Physiol 2023; 601:3717-3737. [PMID: 37477289 DOI: 10.1113/jp284936] [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: 05/02/2023] [Accepted: 07/04/2023] [Indexed: 07/22/2023] Open
Abstract
Potassium channel subfamily K member 3 (KCNK3), encoded by the KCNK3 gene, is part of the two-pore domain potassium channel family, constitutively active at resting membrane potentials in excitable cells, including smooth muscle and cardiac cells. Several physiological and pharmacological mediators, such as intracellular signalling pathways, extracellular pH, hypoxia and anaesthetics, regulate KCNK3 channel function. Recent studies show that modulation of KCNK3 channel expression and function strongly influences pulmonary vascular cell and cardiomyocyte function. The altered activity of KCNK3 in pathological situations such as atrial fibrillation, pulmonary arterial hypertension and right ventricular dysfunction demonstrates the crucial role of KCNK3 in cardiovascular homeostasis. Furthermore, loss of function variants of KCNK3 have been identified in patients suffering from pulmonary arterial hypertension and atrial fibrillation. This review focuses on current knowledge of the role of the KCNK3 channel in pulmonary circulation and the heart, in healthy and pathological conditions.
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Affiliation(s)
- Anaïs Saint-Martin Willer
- Université Paris-Saclay, Faculté de Médecine, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 'Hypertension Pulmonaire: Physiopathologie et Innovation Thérapeutique', Hôpital Marie Lannelongue, Le Plessis-Robinson, France
| | - Joana Santos-Gomes
- Cardiovascular R&D Centre-UnIC@RISE, Department of Surgery and Physiology, Faculty of Medicine of the University of Porto, Porto, Portugal
| | - Rui Adão
- Cardiovascular R&D Centre-UnIC@RISE, Department of Surgery and Physiology, Faculty of Medicine of the University of Porto, Porto, Portugal
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM), Madrid, Spain
- CIBER Enfermedades Respiratorias (Ciberes), Madrid, Spain
| | - Carmen Brás-Silva
- Cardiovascular R&D Centre-UnIC@RISE, Department of Surgery and Physiology, Faculty of Medicine of the University of Porto, Porto, Portugal
| | - Mélanie Eyries
- Département de génétique, Assistance Publique-Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris, France
- INSERM UMRS1166, ICAN - Institute of CardioMetabolism and Nutrition, Sorbonne Université, Paris, France
| | - Francisco Pérez-Vizcaino
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM), Madrid, Spain
- CIBER Enfermedades Respiratorias (Ciberes), Madrid, Spain
| | - Véronique Capuano
- Université Paris-Saclay, Faculté de Médecine, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 'Hypertension Pulmonaire: Physiopathologie et Innovation Thérapeutique', Hôpital Marie Lannelongue, Le Plessis-Robinson, France
| | - David Montani
- Université Paris-Saclay, Faculté de Médecine, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 'Hypertension Pulmonaire: Physiopathologie et Innovation Thérapeutique', Hôpital Marie Lannelongue, Le Plessis-Robinson, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Pneumologie et Soins Intensifs Respiratoires, Centre de Référence de l'Hypertension Pulmonaire, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Fabrice Antigny
- Université Paris-Saclay, Faculté de Médecine, Le Kremlin-Bicêtre, France
- INSERM UMR_S 999 'Hypertension Pulmonaire: Physiopathologie et Innovation Thérapeutique', Hôpital Marie Lannelongue, Le Plessis-Robinson, France
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2
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van den Boom AJ, Zuilhof H. Sulfur-Phenolate Exchange as a Mild, Fast, and High-Yielding Method toward the Synthesis of Sulfonamides. Org Lett 2023; 25:788-793. [PMID: 36720015 PMCID: PMC9926510 DOI: 10.1021/acs.orglett.2c04292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Sulfonamides have many important biological applications, yet their synthesis often involves long reaction times under dry and non-ambient conditions. Here we report the synthesis of a large range of sulfonamides at room temperature using 4-nitrophenyl benzylsulfonate as a starting material. Sulfonamides were prepared from a wide range of aliphatic, linear, and cyclic amines, anilines, and N-methylanilines. The yields and reaction times observed here were comparable to or better than those reported previously, establishing sulfur-phenolate exchange as a viable alternative.
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Affiliation(s)
- Alyssa
F. J. van den Boom
- Laboratory
of Organic Chemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Han Zuilhof
- Laboratory
of Organic Chemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands,School
of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Tianjin 300072, China,
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3
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Fan X, Lu Y, Du G, Liu J. Advances in the Understanding of Two-Pore Domain TASK Potassium Channels and Their Potential as Therapeutic Targets. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238296. [PMID: 36500386 PMCID: PMC9736439 DOI: 10.3390/molecules27238296] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/09/2022] [Accepted: 11/15/2022] [Indexed: 11/29/2022]
Abstract
TWIK-related acid-sensitive K+ (TASK) channels, including TASK-1, TASK-3, and TASK-5, are important members of the two-pore domain potassium (K2P) channel family. TASK-5 is not functionally expressed in the recombinant system. TASK channels are very sensitive to changes in extracellular pH and are active during all membrane potential periods. They are similar to other K2P channels in that they can create and use background-leaked potassium currents to stabilize resting membrane conductance and repolarize the action potential of excitable cells. TASK channels are expressed in both the nervous system and peripheral tissues, including excitable and non-excitable cells, and are widely engaged in pathophysiological phenomena, such as respiratory stimulation, pulmonary hypertension, arrhythmia, aldosterone secretion, cancers, anesthesia, neurological disorders, glucose homeostasis, and visual sensitivity. Therefore, they are important targets for innovative drug development. In this review, we emphasized the recent advances in our understanding of the biophysical properties, gating profiles, and biological roles of TASK channels. Given the different localization ranges and biologically relevant functions of TASK-1 and TASK-3 channels, the development of compounds that selectively target TASK-1 and TASK-3 channels is also summarized based on data reported in the literature.
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Affiliation(s)
- Xueming Fan
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Department of Anesthesiology, Guizhou Provincial People’s Hospital, Guiyang 550002, China
| | - Yongzhi Lu
- Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510700, China
| | - Guizhi Du
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Correspondence: (G.D.); (J.L.)
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Correspondence: (G.D.); (J.L.)
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4
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Gancayco CA, Gerding MR, Breault DT, Beenhakker MP, Barrett PQ, Guagliardo NA. Intrinsic Adrenal TWIK-Related Acid-Sensitive TASK Channel Dysfunction Produces Spontaneous Calcium Oscillations Sufficient to Drive AngII (Angiotensin II)-Unresponsive Hyperaldosteronism. Hypertension 2022; 79:2552-2564. [PMID: 36129175 PMCID: PMC10167771 DOI: 10.1161/hypertensionaha.122.19557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
Ion channel mutations in calcium regulating genes strongly associate with AngII (angiotensin II)-independent aldosterone production. Here, we used an established mouse model of in vivo aldosterone autonomy,
Cyp11b2
-driven deletion of TWIK-related acid-sensitive potassium channels (TASK-1 and TASK-3, termed zona glomerulosa [zG]-TASK-loss-of-function), and selective pharmacological TASK channel inhibition to determine whether channel dysfunction in native, electrically excitable zG cell rosette-assemblies: (1) produces spontaneous calcium oscillatory activity and (2) is sufficient to drive substantial aldosterone autonomy.
Methods:
We imaged calcium activity in adrenal slices expressing a zG-specific calcium reporter (GCaMP3), an in vitro experimental approach that preserves the native rosette assembly and removes potentially confounding extra-adrenal contributions. In parallel experiments, we measured acute aldosterone production from adrenal slice cultures.
Results:
Absent from untreated WT slices, we find that either adrenal-specific genetic deletion or acute pharmacological TASK channel inhibition produces spontaneous oscillatory bursting behavior and steroidogenic activity (2.4-fold) that are robust, sustained, and equivalent to activities evoked by 3 nM AngII in WT slices. Moreover, spontaneous activity in zG-TASK-loss-of-function slices and inhibitor-evoked activity in WT slices are unresponsive to AngII regulation over a wide range of concentrations (50 pM to 3 µM).
Conclusions:
We provide proof of principle that spontaneous activity of zG cells within classic rosette assemblies evoked solely by a change in an intrinsic, dominant resting-state conductance can be a significant source of AngII-independent aldosterone production from native tissue.
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Affiliation(s)
| | - Molly R. Gerding
- Department of Pharmacology (M.R.G., M.P.B., P.Q.B., N.A.G.), University of Virginia, Charlottesville
| | - David T. Breault
- Division of Endocrinology, Boston Children’s Hospital, MA (D.T.B.)
- Harvard Stem Cell Institute, Cambridge, MA (D.T.B.)
| | - Mark P. Beenhakker
- Department of Pharmacology (M.R.G., M.P.B., P.Q.B., N.A.G.), University of Virginia, Charlottesville
| | - Paula Q. Barrett
- Department of Pharmacology (M.R.G., M.P.B., P.Q.B., N.A.G.), University of Virginia, Charlottesville
| | - Nick A. Guagliardo
- Department of Pharmacology (M.R.G., M.P.B., P.Q.B., N.A.G.), University of Virginia, Charlottesville
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5
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Wen X, Liao P, Luo Y, Yang L, Yang H, Liu L, Jiang R. Tandem pore domain acid-sensitive K channel 3 (TASK-3) regulates visual sensitivity in healthy and aging retina. SCIENCE ADVANCES 2022; 8:eabn8785. [PMID: 36070380 PMCID: PMC9451158 DOI: 10.1126/sciadv.abn8785] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
Retinal ganglion cells (RGCs) not only collect but also integrate visual signals and send them from the retina to the brain. The mechanisms underlying the RGC integration of synaptic activity within retinal circuits have not been fully explored. Here, we identified a pronounced expression of tandem pore domain acid-sensitive potassium channel 3 (TASK-3), a two-pore domain potassium channel (K2P), in RGCs. By using a specific antagonist and TASK-3 knockout mice, we found that TASK-3 regulates the intrinsic excitability and the light sensitivity of RGCs by sensing neuronal activity-dependent extracellular acidification. In vivo, the blockade or loss of TASK-3 dampened pupillary light reflex, visual acuity, and contrast sensitivity. Furthermore, overexpressing TASK-3 specifically in RGCs using an adeno-associated virus approach restored the visual function of TASK-3 knockout mice and aged mice where the expression and function of TASK-3 were reduced. Thus, our results provide evidence that implicates a critical role of K2P in visual processing in the retina.
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Affiliation(s)
- Xiangyi Wen
- Department of Ophthalmology, Department of Optometry and Visual Science, Laboratory of Optometry and Vision Sciences, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Ping Liao
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Yuncheng Luo
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Linghui Yang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Huaiyu Yang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Longqian Liu
- Department of Ophthalmology, Department of Optometry and Visual Science, Laboratory of Optometry and Vision Sciences, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Ruotian Jiang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
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6
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Wrzosek A, Gałecka S, Żochowska M, Olszewska A, Kulawiak B. Alternative Targets for Modulators of Mitochondrial Potassium Channels. Molecules 2022; 27:299. [PMID: 35011530 PMCID: PMC8746388 DOI: 10.3390/molecules27010299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial potassium channels control potassium influx into the mitochondrial matrix and thus regulate mitochondrial membrane potential, volume, respiration, and synthesis of reactive oxygen species (ROS). It has been found that pharmacological activation of mitochondrial potassium channels during ischemia/reperfusion (I/R) injury activates cytoprotective mechanisms resulting in increased cell survival. In cancer cells, the inhibition of these channels leads to increased cell death. Therefore, mitochondrial potassium channels are intriguing targets for the development of new pharmacological strategies. In most cases, however, the substances that modulate the mitochondrial potassium channels have a few alternative targets in the cell. This may result in unexpected or unwanted effects induced by these compounds. In our review, we briefly present the various classes of mitochondrial potassium (mitoK) channels and describe the chemical compounds that modulate their activity. We also describe examples of the multidirectional activity of the activators and inhibitors of mitochondrial potassium channels.
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Affiliation(s)
- Antoni Wrzosek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Shur Gałecka
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Monika Żochowska
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Anna Olszewska
- Department of Histology, Medical University of Gdansk, 1a Debinki, 80-211 Gdansk, Poland;
| | - Bogusz Kulawiak
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
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7
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Ramírez D, Mejia-Gutierrez M, Insuasty B, Rinné S, Kiper AK, Platzk M, Müller T, Decher N, Quiroga J, De-la-Torre P, González W. 5-(Indol-2-yl)pyrazolo[3,4- b]pyridines as a New Family of TASK-3 Channel Blockers: A Pharmacophore-Based Regioselective Synthesis. Molecules 2021; 26:molecules26133897. [PMID: 34202296 PMCID: PMC8271858 DOI: 10.3390/molecules26133897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 11/16/2022] Open
Abstract
TASK channels belong to the two-pore-domain potassium (K2P) channels subfamily. These channels modulate cellular excitability, input resistance, and response to synaptic stimulation. TASK-channel inhibition led to membrane depolarization. TASK-3 is expressed in different cancer cell types and neurons. Thus, the discovery of novel TASK-3 inhibitors makes these bioactive compounds very appealing to explore new cancer and neurological therapies. TASK-3 channel blockers are very limited to date, and only a few heterofused compounds have been reported in the literature. In this article, we combined a pharmacophore hypothesis with molecular docking to address for the first time the rational design, synthesis, and evaluation of 5-(indol-2-yl)pyrazolo[3,4-b]pyridines as a novel family of human TASK-3 channel blockers. Representative compounds of the synthesized library were assessed against TASK-3 using Fluorometric imaging plate reader-Membrane Potential assay (FMP). Inhibitory properties were validated using two-electrode voltage-clamp (TEVC) methods. We identified one active hit compound (MM-3b) with our systematic pipeline, exhibiting an IC50 ≈ 30 μM. Molecular docking models suggest that compound MM-3b binds to TASK-3 at the bottom of the selectivity filter in the central cavity, similar to other described TASK-3 blockers such as A1899 and PK-THPP. Our in silico and experimental studies provide a new tool to predict and design novel TASK-3 channel blockers.
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Affiliation(s)
- David Ramírez
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Llano Subercaseaux 2801-Piso 5, Santiago 8900000, Chile
- Correspondence: (D.R.); (P.D.-l.-T.); (W.G.)
| | - Melissa Mejia-Gutierrez
- Heterocyclic Compounds Research Group, Department of Chemistry, Universidad del Valle, A.A, Cali 760031, Colombia; (M.M.-G.); (B.I.); (J.Q.)
| | - Braulio Insuasty
- Heterocyclic Compounds Research Group, Department of Chemistry, Universidad del Valle, A.A, Cali 760031, Colombia; (M.M.-G.); (B.I.); (J.Q.)
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Center for Mind, Brain and Behavior (CMBB), Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany; (S.R.); (A.K.K.); (N.D.)
| | - Aytug K. Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Center for Mind, Brain and Behavior (CMBB), Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany; (S.R.); (A.K.K.); (N.D.)
| | - Magdalena Platzk
- Joint Pulmonary Drug Discovery Lab Bayer-MGH, Boston, MA 02114, USA;
| | - Thomas Müller
- Bayer AG, Research & Development, Pharmaceuticals, D-42096 Wuppertal, Germany;
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Center for Mind, Brain and Behavior (CMBB), Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany; (S.R.); (A.K.K.); (N.D.)
| | - Jairo Quiroga
- Heterocyclic Compounds Research Group, Department of Chemistry, Universidad del Valle, A.A, Cali 760031, Colombia; (M.M.-G.); (B.I.); (J.Q.)
| | - Pedro De-la-Torre
- Department of Otolaryngology, Harvard Medical School and Massachusetts Eye and Ear, 243 Charles St, Boston, MA 02114, USA
- Caribe Therapeutics, Vía 40 No. 69-111, Oficina 804 A, Barranquilla 080002, Colombia
- Correspondence: (D.R.); (P.D.-l.-T.); (W.G.)
| | - Wendy González
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Poniente No. 1141, Talca 3460000, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3460000, Chile
- Correspondence: (D.R.); (P.D.-l.-T.); (W.G.)
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8
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Szabo I, Zoratti M, Biasutto L. Targeting mitochondrial ion channels for cancer therapy. Redox Biol 2021; 42:101846. [PMID: 33419703 PMCID: PMC8113036 DOI: 10.1016/j.redox.2020.101846] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/19/2020] [Accepted: 12/21/2020] [Indexed: 12/12/2022] Open
Abstract
Pharmacological targeting of mitochondrial ion channels is emerging as a promising approach to eliminate cancer cells; as most of these channels are differentially expressed and/or regulated in cancer cells in comparison to healthy ones, this strategy may selectively eliminate the former. Perturbation of ion fluxes across the outer and inner membranes is linked to alterations of redox state, membrane potential and bioenergetic efficiency. This leads to indirect modulation of oxidative phosphorylation, which is/may be fundamental for both cancer and cancer stem cell survival. Furthermore, given the crucial contribution of mitochondria to intrinsic apoptosis, modulation of their ion channels leading to cytochrome c release may be of great advantage in case of resistance to drugs triggering apoptotic events upstream of the mitochondrial phase. In the present review, we give an overview of the known mitochondrial ion channels and of their modulators capable of killing cancer cells. In addition, we discuss state-of-the-art strategies using mitochondriotropic drugs or peptide-based approaches allowing a more efficient and selective targeting of mitochondrial ion channel-linked events.
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Affiliation(s)
- Ildiko Szabo
- Department of Biology, University of Padova, Italy; CNR Institute of Neurosciences, Padova, Italy.
| | | | - Lucia Biasutto
- CNR Institute of Neurosciences, Padova, Italy; Department of Biomedical Sciences, University of Padova, Italy
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9
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Checchetto V, Leanza L, De Stefani D, Rizzuto R, Gulbins E, Szabo I. Mitochondrial K + channels and their implications for disease mechanisms. Pharmacol Ther 2021; 227:107874. [PMID: 33930454 DOI: 10.1016/j.pharmthera.2021.107874] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/12/2021] [Indexed: 02/06/2023]
Abstract
The field of mitochondrial ion channels underwent a rapid development during the last decade, thanks to the molecular identification of some of the nuclear-encoded organelle channels and to advances in strategies allowing specific pharmacological targeting of these proteins. Thereby, genetic tools and specific drugs aided definition of the relevance of several mitochondrial channels both in physiological as well as pathological conditions. Unfortunately, in the case of mitochondrial K+ channels, efforts of genetic manipulation provided only limited results, due to their dual localization to mitochondria and to plasma membrane in most cases. Although the impact of mitochondrial K+ channels on human diseases is still far from being genuinely understood, pre-clinical data strongly argue for their substantial role in the context of several pathologies, including cardiovascular and neurodegenerative diseases as well as cancer. Importantly, these channels are druggable targets, and their in-depth investigation could thus pave the way to the development of innovative small molecules with huge therapeutic potential. In the present review we summarize the available experimental evidence that mechanistically link mitochondrial potassium channels to the above pathologies and underline the possibility of exploiting them for therapy.
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Affiliation(s)
| | - Luigi Leanza
- Department of Biology, University of Padova, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Italy
| | - Erich Gulbins
- Department of Molecular Biology, University of Duisburg-Essen, Germany
| | - Ildiko Szabo
- Department of Biology, University of Padova, Italy; CNR Institute of Neurosciences, Italy.
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10
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Natale AM, Deal PE, Minor DL. Structural Insights into the Mechanisms and Pharmacology of K 2P Potassium Channels. J Mol Biol 2021; 433:166995. [PMID: 33887333 PMCID: PMC8436263 DOI: 10.1016/j.jmb.2021.166995] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/08/2021] [Accepted: 04/09/2021] [Indexed: 01/10/2023]
Abstract
Leak currents, defined as voltage and time independent flows of ions across cell membranes, are central to cellular electrical excitability control. The K2P (KCNK) potassium channel class comprises an ion channel family that produces potassium leak currents that oppose excitation and stabilize the resting membrane potential in cells in the brain, cardiovascular system, immune system, and sensory organs. Due to their widespread tissue distribution, K2Ps contribute to many physiological and pathophysiological processes including anesthesia, pain, arrythmias, ischemia, hypertension, migraine, intraocular pressure regulation, and lung injury responses. Structural studies of six homomeric K2Ps have established the basic architecture of this channel family, revealed key moving parts involved in K2P function, uncovered the importance of asymmetric pinching and dilation motions in the K2P selectivity filter (SF) C-type gate, and defined two K2P structural classes based on the absence or presence of an intracellular gate. Further, a series of structures characterizing K2P:modulator interactions have revealed a striking polysite pharmacology housed within a relatively modestly sized (~70 kDa) channel. Binding sites for small molecules or lipids that control channel function are found at every layer of the channel structure, starting from its extracellular side through the portion that interacts with the membrane bilayer inner leaflet. This framework provides the basis for understanding how gating cues sensed by different channel parts control function and how small molecules and lipids modulate K2P activity. Such knowledge should catalyze development of new K2P modulators to probe function and treat a wide range of disorders.
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Affiliation(s)
- Andrew M Natale
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
| | - Parker E Deal
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
| | - Daniel L Minor
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA; Departments of Biochemistry and Biophysics, and Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, University of California, San Francisco, CA 94158, USA; Kavli Institute for Fundamental Neuroscience University of California, San Francisco, CA 94158, USA; Molecular Biophysics and Integrated Bio-imaging Division Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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11
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Bachmann M, Rossa A, Antoniazzi G, Biasutto L, Carrer A, Campagnaro M, Leanza L, Gonczi M, Csernoch L, Paradisi C, Mattarei A, Zoratti M, Szabo I. Synthesis and cellular effects of a mitochondria-targeted inhibitor of the two-pore potassium channel TASK-3. Pharmacol Res 2021; 164:105326. [PMID: 33338625 DOI: 10.1016/j.phrs.2020.105326] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 11/03/2020] [Accepted: 11/23/2020] [Indexed: 01/25/2023]
Abstract
The two-pore potassium channel TASK-3 has been shown to localize to both the plasma membrane and the mitochondrial inner membrane. TASK-3 is highly expressed in melanoma and breast cancer cells and has been proposed to promote tumor formation. Here we investigated whether pharmacological modulation of TASK-3, and specifically of mitochondrial TASK-3 (mitoTASK-3), had any effect on cancer cell survival and mitochondrial physiology. A novel, mitochondriotropic version of the specific TASK-3 inhibitor IN-THPP has been synthesized by addition of a positively charged triphenylphosphonium moiety. While IN-THPP was unable to induce apoptosis, mitoIN-THPP decreased survival of breast cancer cells and efficiently killed melanoma lines, which we show to express mitoTASK-3. Cell death was accompanied by mitochondrial membrane depolarization and fragmentation of the mitochondrial network, suggesting a role of the channel in the maintenance of the correct function of this organelle. In accordance, cells treated with mitoIN-THPP became rapidly depleted of mitochondrial ATP which resulted in activation of the AMP-dependent kinase AMPK. Importantly, cell survival was not affected in mouse embryonic fibroblasts and the effect of mitoIN-THPP was less pronounced in human melanoma cells stably knocked down for TASK-3 expression, indicating a certain degree of selectivity of the drug both for pathological cells and for the channel. In addition, mitoIN-THPP inhibited cancer cell migration to a higher extent than IN-THPP in two melanoma cell lines. In summary, our results point to the importance of mitoTASK-3 for melanoma cell survival and migration.
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Affiliation(s)
| | - Andrea Rossa
- Department of Chemical Sciences, University of Padua, Italy
| | | | - Lucia Biasutto
- CNR Institute of Neuroscience, Padua, Italy; Department of Biomedical Sciences, University of Padua, Italy
| | - Andrea Carrer
- Department of Biology, University of Padua, Italy; Department of Biomedical Sciences, University of Padua, Italy
| | | | - Luigi Leanza
- Department of Biology, University of Padua, Italy
| | - Monika Gonczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Hungary
| | - Laszlo Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Hungary
| | | | - Andrea Mattarei
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Italy
| | - Mario Zoratti
- CNR Institute of Neuroscience, Padua, Italy; Department of Biomedical Sciences, University of Padua, Italy
| | - Ildiko Szabo
- Department of Biology, University of Padua, Italy; CNR Institute of Neuroscience, Padua, Italy.
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12
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Liao P, Qiu Y, Mo Y, Fu J, Song Z, Huang L, Bai S, Wang Y, Zhu JJ, Tian F, Chen Z, Pan N, Sun EY, Yang L, Lan X, Chen Y, Huang D, Sun P, Zhao L, Yang D, Lu W, Yang T, Xiao J, Li WG, Gao Z, Shen B, Zhang Q, Liu J, Jiang H, Jiang R, Yang H. Selective activation of TWIK-related acid-sensitive K + 3 subunit-containing channels is analgesic in rodent models. Sci Transl Med 2020; 11:11/519/eaaw8434. [PMID: 31748231 DOI: 10.1126/scitranslmed.aaw8434] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 06/27/2019] [Accepted: 09/19/2019] [Indexed: 02/05/2023]
Abstract
The paucity of selective agonists for TWIK-related acid-sensitive K+ 3 (TASK-3) channel, a member of two-pore domain K+ (K2P) channels, has contributed to our limited understanding of its biological functions. By targeting a druggable transmembrane cavity using a structure-based drug design approach, we discovered a biguanide compound, CHET3, as a highly selective allosteric activator for TASK-3-containing K2P channels, including TASK-3 homomers and TASK-3/TASK-1 heteromers. CHET3 displayed potent analgesic effects in vivo in a variety of acute and chronic pain models in rodents that could be abolished pharmacologically or by genetic ablation of TASK-3. We further found that TASK-3-containing channels anatomically define a unique population of small-sized, transient receptor potential cation channel subfamily M member 8 (TRPM8)-, transient receptor potential cation channel subfamily V member 1 (TRPV1)-, or tyrosine hydroxylase (TH)-positive nociceptive sensory neurons and functionally regulate their membrane excitability, supporting CHET3 analgesic effects in thermal hyperalgesia and mechanical allodynia under chronic pain. Overall, our proof-of-concept study reveals TASK-3-containing K2P channels as a druggable target for treating pain.
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Affiliation(s)
- Ping Liao
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Yunguang Qiu
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiqing Mo
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Jie Fu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Zhenpeng Song
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Lu Huang
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Suwen Bai
- Department of Physiology, Anhui Medical University, Hefei, Anhui 230032, China
| | - Yang Wang
- Department of Physiology, Anhui Medical University, Hefei, Anhui 230032, China
| | - Jia-Jie Zhu
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Fuyun Tian
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Zhuo Chen
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Nanfang Pan
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Er-Yi Sun
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Linghui Yang
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Xi Lan
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yinbin Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Dongping Huang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Peihua Sun
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Lifen Zhao
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Dehua Yang
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Weiqiang Lu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Tingting Yang
- Cardiac Regeneration and Ageing Lab, School of Life Science, Shanghai University, Shanghai 200444, China
| | - Junjie Xiao
- Cardiac Regeneration and Ageing Lab, School of Life Science, Shanghai University, Shanghai 200444, China
| | - Wei-Guang Li
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Zhaobing Gao
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Bing Shen
- Department of Physiology, Anhui Medical University, Hefei, Anhui 230032, China
| | - Qiansen Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Hualiang Jiang
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ruotian Jiang
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China.
| | - Huaiyu Yang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China.
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13
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Withaferin A suppresses breast cancer cell proliferation by inhibition of the two-pore domain potassium (K2P9) channel TASK-3. Biomed Pharmacother 2020; 129:110383. [PMID: 32563149 DOI: 10.1016/j.biopha.2020.110383] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/26/2020] [Accepted: 06/07/2020] [Indexed: 12/30/2022] Open
Abstract
Withaferin A (WFA), a C5,C6-epoxy steroidal lactone isolated from the medicinal plant Withania somnifera (L.) Dunal, inhibits growth of tumor cells in different cancer types. However, the mechanisms underlying the effect of WFA on tumor cells are not fully understood. In the present study, we evaluated the blockade of TASK-3 channels by WFA in TASK-3-expressing HEK-293 cells. Explore if the WFA-mediated TASK-3 blockade can be used as a pharmacological tool to decrease the cell viability in cancer cells. A combination of functional experiments (patch-clamp, gene downregulation, overexpression and pharmacological inhibition) and molecular docking analysis were used to get insights into the mechanism by which the inhibition of TASK-3 by WFA affects the growth and viability of cancer cells. Withaferin A was found to inhibit the activity of TASK-3 channels. The inhibitory effect of Withaferin A on TASK-3 potassium currents was dose-dependent and independent of voltage. Molecular modeling studies identified putative WFA-binding sites in TASK-3 channel involved the channel blockade. In agreements with the molecular modeling predictions, mutation of residues F125 to A (F125A), L197 to V (L197 V) and the double mutant F125A-L197 V markedly decreased the WFA-induced inhibition of TASK-3. Finally, the cytotoxic effect of WFA was tested in MDA-MB-231 human breast cancer cells transfected with TASK-3 or shRNA that decreases TASK-3 expression. Together, our results show that the cytotoxic effect of WFA on fully transformed MDA-MB-231 cells depends on the expression of TASK-3. Herein, we also provide insights into the mechanism of TASK-3 inhibition by WFA.
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14
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García G, Noriega-Navarro R, Martínez-Rojas VA, Gutiérrez-Lara EJ, Oviedo N, Murbartián J. Spinal TASK-1 and TASK-3 modulate inflammatory and neuropathic pain. Eur J Pharmacol 2019; 862:172631. [DOI: 10.1016/j.ejphar.2019.172631] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/09/2019] [Accepted: 08/27/2019] [Indexed: 12/13/2022]
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15
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Discovery of Novel TASK-3 Channel Blockers Using a Pharmacophore-Based Virtual Screening. Int J Mol Sci 2019; 20:ijms20164014. [PMID: 31426491 PMCID: PMC6720600 DOI: 10.3390/ijms20164014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/06/2019] [Accepted: 08/13/2019] [Indexed: 02/06/2023] Open
Abstract
TASK-3 is a two-pore domain potassium (K2P) channel highly expressed in the hippocampus, cerebellum, and cortex. TASK-3 has been identified as an oncogenic potassium channel and it is overexpressed in different cancer types. For this reason, the development of new TASK-3 blockers could influence the pharmacological treatment of cancer and several neurological conditions. In the present work, we searched for novel TASK-3 blockers by using a virtual screening protocol that includes pharmacophore modeling, molecular docking, and free energy calculations. With this protocol, 19 potential TASK-3 blockers were identified. These molecules were tested in TASK-3 using patch clamp, and one blocker (DR16) was identified with an IC50 = 56.8 ± 3.9 μM. Using DR16 as a scaffold, we designed DR16.1, a novel TASK-3 inhibitor, with an IC50 = 14.2 ± 3.4 μM. Our finding takes on greater relevance considering that not many inhibitory TASK-3 modulators have been reported in the scientific literature until today. These two novel TASK-3 channel inhibitors (DR16 and DR16.1) are the first compounds found using a pharmacophore-based virtual screening and rational drug design protocol.
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16
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Riedelsberger J, Obando PA, Gonzalez W. Yeast strain Saccharomyces cerevisiae BYT45 lacking the cation extrusion systems ENA1-5 and NHA1 is suitable for the characterization of TASK-3 potassium channel antagonists. FEMS Yeast Res 2019; 19:5524363. [PMID: 31247642 DOI: 10.1093/femsyr/foz044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 06/24/2019] [Indexed: 11/13/2022] Open
Abstract
Finding new potential antagonists of potassium channels is a continuing task. TASK potassium channels operate over a large physiological range of membrane voltages, why they are thought to contribute to the excitability and resting potential of mammalian membrane potentials. Additionally, they are regulated by extracellular stimuli like changes in pH and K+ concentrations. TASK malfunctions are associated with diseases, which makes them popular targets for the search of new antagonists. Identification of channel inhibitors can be a time-consuming and expensive project. Here, we present an easy-to-use and inexpensive yeast system for the expression of the two-pore domain K+ channel TASK-3, and for the characterization of TASK-3 antagonists. The Saccharomyces cerevisiae strain BYT45 was used to express guinea pig TASK-3. The system allowed the expression and characterization of TASK-3 at variable pH values and K+ concentrations. Three known TASK-3 antagonists have been tested in the BYT45 yeast system: PK-THPP, ZnCl2 and Bupivacaine. Their inhibitory effect on TASK-3 was tested in solid and liquid media assays, and half maximal inhibitory concentrations were estimated. Although the system is less sensitive than more refined systems, the antagonistic activity could be confirmed for all three inhibitors.
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Affiliation(s)
- Janin Riedelsberger
- Centro de Bioinformática y Simulación Molecular, Facultad de Ingeniería, Universidad de Talca, 3460000 Talca, Chile
| | - Patricia A Obando
- Centro de Bioinformática y Simulación Molecular, Facultad de Ingeniería, Universidad de Talca, 3460000 Talca, Chile
| | - Wendy Gonzalez
- Centro de Bioinformática y Simulación Molecular, Facultad de Ingeniería, Universidad de Talca, 3460000 Talca, Chile.,Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Centro de Bioinformática y Simulación Molecular, Universidad de Talca, 2 Norte 685, 3460000 Talca, Chile
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17
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Bedoya M, Rinné S, Kiper AK, Decher N, González W, Ramírez D. TASK Channels Pharmacology: New Challenges in Drug Design. J Med Chem 2019; 62:10044-10058. [PMID: 31260312 DOI: 10.1021/acs.jmedchem.9b00248] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Rational drug design targeting ion channels is an exciting and always evolving research field. New medicinal chemistry strategies are being implemented to explore the wild chemical space and unravel the molecular basis of the ion channels modulators binding mechanisms. TASK channels belong to the two-pore domain potassium channel family and are modulated by extracellular acidosis. They are extensively distributed along the cardiovascular and central nervous systems, and their expression is up- and downregulated in different cancer types, which makes them an attractive therapeutic target. However, TASK channels remain unexplored, and drugs designed to target these channels are poorly selective. Here, we review TASK channels properties and their known blockers and activators, considering the new challenges in ion channels drug design and focusing on the implementation of computational methodologies in the drug discovery process.
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Affiliation(s)
- Mauricio Bedoya
- Centro de Bioinformática y Simulación Molecular (CBSM) , Universidad de Talca , 1 Poniente No. 1141 , 3460000 Talca , Chile
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior, MCMBB , Philipps-University of Marburg , Deutschhausstraße 2 , Marburg 35037 , Germany
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior, MCMBB , Philipps-University of Marburg , Deutschhausstraße 2 , Marburg 35037 , Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior, MCMBB , Philipps-University of Marburg , Deutschhausstraße 2 , Marburg 35037 , Germany
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular (CBSM) , Universidad de Talca , 1 Poniente No. 1141 , 3460000 Talca , Chile.,Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD) , Universidad de Talca , 1 Poniente No. 1141 , 3460000 Talca , Chile
| | - David Ramírez
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud , Universidad Autónoma de Chile , El Llano Subercaseaux 2801, Piso 6 , 8900000 Santiago , Chile
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18
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Ramírez D, Bedoya M, Kiper AK, Rinné S, Morales-Navarro S, Hernández-Rodríguez EW, Sepúlveda FV, Decher N, González W. Structure/Activity Analysis of TASK-3 Channel Antagonists Based on a 5,6,7,8 tetrahydropyrido[4,3-d]pyrimidine. Int J Mol Sci 2019; 20:ijms20092252. [PMID: 31067753 PMCID: PMC6539479 DOI: 10.3390/ijms20092252] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/18/2019] [Accepted: 04/20/2019] [Indexed: 11/16/2022] Open
Abstract
TASK-3 potassium (K+) channels are highly expressed in the central nervous system, regulating the membrane potential of excitable cells. TASK-3 is involved in neurotransmitter action and has been identified as an oncogenic K+ channel. For this reason, the understanding of the action mechanism of pharmacological modulators of these channels is essential to obtain new therapeutic strategies. In this study we describe the binding mode of the potent antagonist PK-THPP into the TASK-3 channel. PK-THPP blocks TASK-1, the closest relative channel of TASK-3, with almost nine-times less potency. Our results confirm that the binding is influenced by the fenestrations state of TASK-3 channels and occurs when they are open. The binding is mainly governed by hydrophobic contacts between the blocker and the residues of the binding site. These interactions occur not only for PK-THPP, but also for the antagonist series based on 5,6,7,8 tetrahydropyrido[4,3-d]pyrimidine scaffold (THPP series). However, the marked difference in the potency of THPP series compounds such as 20b, 21, 22 and 23 (PK-THPP) respect to compounds such as 17b, inhibiting TASK-3 channels in the micromolar range is due to the presence of a hydrogen bond acceptor group that can establish interactions with the threonines of the selectivity filter.
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Affiliation(s)
- David Ramírez
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile. El Llano Subercaseaux 2801-Piso 6, 7500912 Santiago, Chile.
| | - Mauricio Bedoya
- Centro de Bioinformática y Simulación Molecular (CBSM), Universidad de Talca. 1 Poniente No. 1141, 3460000 Talca, Chile.
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany.
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany.
| | - Samuel Morales-Navarro
- Bachillerato en Ciencias, Facultad de Ciencias, Universidad Santo Tomás, Av. Circunvalación Poniente #1855, 3460000 Talca, Chile.
| | - Erix W Hernández-Rodríguez
- Centro de Bioinformática y Simulación Molecular (CBSM), Universidad de Talca. 1 Poniente No. 1141, 3460000 Talca, Chile.
- Escuela de Química y Farmacia. Facultad de Medicina. Universidad Católica del Maule, 3460000 Talca, Chile.
| | | | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany.
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular (CBSM), Universidad de Talca. 1 Poniente No. 1141, 3460000 Talca, Chile.
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, 3460000 Talca, Chile.
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19
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Kawasaki K, Suzuki Y, Yamamura H, Imaizumi Y. Development of a Novel Cell-Based Assay System for High-Throughput Screening of Compounds Acting on Background Two-Pore Domain K + Channels. SLAS DISCOVERY 2019; 24:641-652. [PMID: 30802418 DOI: 10.1177/2472555219829745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Two-pore domain K+ (K2P) channels are thought to be druggable targets. However, only a few agents specific for K2P channels have been identified, presumably due to the lack of an efficient screening system. To develop a new high-throughput screening (HTS) system targeting these channels, we have established a HEK293-based "test cell" expressing a mutated Na+ channel (Nav1.5) with markedly slowed inactivation, as well as a K+ channel (Kir2.1) that sets the membrane potential quite negative, close to K+ equilibrium potential. We found in this system that Kir2.1 block by 100 μM Ba2+ application consistently elicited a large depolarization like a long-lasting action potential. This maneuver resulted in cell death, presumably due to the sustained Na+ influx. When either the TWIK-related acid-sensitive K+ (TASK)-1 or TASK-3 channel was expressed in the test cells, Ba2+-induced cell death was markedly weakened. Stronger activation of TASK-1 by extracellular acidification further decreased the cell death. In contrast, the presence of K2P channel blockers enhanced cell death. IC50 values for TASK-1 and/or TASK-3 blockers acquired by measurements of relative cell viability were comparable to those obtained using patch-clamp recordings. Both blockers and openers of K2P channels can be accurately assessed with high efficiency and throughput by this novel HTS system.
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Affiliation(s)
- Keisuke Kawasaki
- 1 Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Yoshiaki Suzuki
- 1 Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Hisao Yamamura
- 1 Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Yuji Imaizumi
- 1 Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan.,2 Department of Research and Development, ChanneloSearch Technology Co., Ltd., Nagoya, Japan
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20
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Pope L, Arrigoni C, Lou H, Bryant C, Gallardo-Godoy A, Renslo AR, Minor DL. Protein and Chemical Determinants of BL-1249 Action and Selectivity for K 2P Channels. ACS Chem Neurosci 2018; 9:3153-3165. [PMID: 30089357 PMCID: PMC6302903 DOI: 10.1021/acschemneuro.8b00337] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
K2P potassium channels generate leak currents that stabilize the resting membrane potential of excitable cells. Various K2P channels are implicated in pain, ischemia, depression, migraine, and anesthetic responses, making this family an attractive target for small molecule modulator development efforts. BL-1249, a compound from the fenamate class of nonsteroidal anti-inflammatory drugs is known to activate K2P2.1(TREK-1), the founding member of the thermo- and mechanosensitive TREK subfamily; however, its mechanism of action and effects on other K2P channels are not well-defined. Here, we demonstrate that BL-1249 extracellular application activates all TREK subfamily members but has no effect on other K2P subfamilies. Patch clamp experiments demonstrate that, similar to the diverse range of other chemical and physical TREK subfamily gating cues, BL-1249 stimulates the selectivity filter "C-type" gate that controls K2P function. BL-1249 displays selectivity among the TREK subfamily, activating K2P2.1(TREK-1) and K2P10.1(TREK-2) ∼10-fold more potently than K2P4.1(TRAAK). Investigation of mutants and K2P2.1(TREK-1)/K2P4.1(TRAAK) chimeras highlight the key roles of the C-terminal tail in BL-1249 action and identify the M2/M3 transmembrane helix interface as a key site of BL-1249 selectivity. Synthesis and characterization of a set of BL-1249 analogs demonstrates that both the tetrazole and opposing tetralin moieties are critical for function, whereas the conformational mobility between the two ring systems impacts selectivity. Together, our findings underscore the landscape of modes by which small molecules can affect K2P channels and provide crucial information for the development of better and more selective K2P modulators of the TREK subfamily.
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Affiliation(s)
| | | | | | | | | | | | - Daniel L. Minor
- Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 United States
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21
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Neurokinin-3 receptor activation selectively prolongs atrial refractoriness by inhibition of a background K + channel. Nat Commun 2018; 9:4357. [PMID: 30341287 PMCID: PMC6195571 DOI: 10.1038/s41467-018-06530-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 09/07/2018] [Indexed: 11/29/2022] Open
Abstract
The cardiac autonomic nervous system (ANS) controls normal atrial electrical function. The cardiac ANS produces various neuropeptides, among which the neurokinins, whose actions on atrial electrophysiology are largely unknown. We here demonstrate that the neurokinin substance-P (Sub-P) activates a neurokinin-3 receptor (NK-3R) in rabbit, prolonging action potential (AP) duration through inhibition of a background potassium current. In contrast, ventricular AP duration was unaffected by NK-3R activation. NK-3R stimulation lengthened atrial repolarization in intact rabbit hearts and consequently suppressed arrhythmia duration and occurrence in a rabbit isolated heart model of atrial fibrillation (AF). In human atrial appendages, the phenomenon of NK-3R mediated lengthening of atrial repolarization was also observed. Our findings thus uncover a pathway to selectively modulate atrial AP duration by activation of a hitherto unidentified neurokinin-3 receptor in the membrane of atrial myocytes. NK-3R stimulation may therefore represent an anti-arrhythmic concept to suppress re-entry-based atrial tachyarrhythmias, including AF. The cardiac autonomic nervous system produces various neuropeptides, such as neurokinin substance-P (Sub-P), whose function remains largely unclear. Here, authors show that Sub-P causes a receptor-mediated prolongation of the atrial action potential through a reduced background potassium current, and prevents atrial fibrillation.
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22
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O'Donohoe PB, Huskens N, Turner PJ, Pandit JJ, Buckler KJ. A1899, PK-THPP, ML365, and Doxapram inhibit endogenous TASK channels and excite calcium signaling in carotid body type-1 cells. Physiol Rep 2018; 6:e13876. [PMID: 30284397 PMCID: PMC6170881 DOI: 10.14814/phy2.13876] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 08/24/2018] [Indexed: 01/10/2023] Open
Abstract
Sensing of hypoxia and acidosis in arterial chemoreceptors is thought to be mediated through the inhibition of TASK and possibly other (e.g., BKCa ) potassium channels which leads to membrane depolarization, voltage-gated Ca-entry, and neurosecretion. Here, we investigate the effects of pharmacological inhibitors on TASK channel activity and [Ca2+ ]i -signaling in isolated neonatal rat type-1 cells. PK-THPP inhibited TASK channel activity in cell attached patches by up to 90% (at 400 nmol/L). A1899 inhibited TASK channel activity by 35% at 400 nmol/L. PK-THPP, A1899 and Ml 365 all evoked a rapid increase in type-1 cell [Ca2+ ]i . These [Ca2+ ]i responses were abolished in Ca2+ -free solution and greatly attenuated by Ni2+ (2 mM) suggesting that depolarization and voltage-gated Ca2+ -entry mediated the rise in [Ca2+ ]i. Doxapram (50 μmol/L), a respiratory stimulant, also inhibited type-1 cell TASK channel activity and increased [Ca2+ ]i. . We also tested the effects of combined inhibition of BKCa and TASK channels. TEA (5 mmol/L) slightly increased [Ca2+ ]i in the presence of PK-THPP and A1899. Paxilline (300 nM) and iberiotoxin (50 nmol/L) also slightly increased [Ca2+ ]i in the presence of A1899 but not in the presence of PK-THPP. In general [Ca2+ ]i responses to TASK inhibitors, alone or in combination with BKCa inhibitors, were smaller than the [Ca2+ ]i responses evoked by hypoxia. These data confirm that TASK channel inhibition is capable of evoking membrane depolarization and robust voltage-gated Ca2+ -entry but suggest that this, even with concomitant inhibition of BKCa channels, may be insufficient to account fully for the [Ca2+ ]i -response to hypoxia.
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Affiliation(s)
- Peadar B. O'Donohoe
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
- Nuffield Department of AnaestheticsOxford University HospitalsOxfordUnited Kingdom
| | - Nicky Huskens
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
| | - Philip J. Turner
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
| | - Jaideep J. Pandit
- Nuffield Department of AnaestheticsOxford University HospitalsOxfordUnited Kingdom
| | - Keith J. Buckler
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
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23
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HCN Channels: New Therapeutic Targets for Pain Treatment. Molecules 2018; 23:molecules23092094. [PMID: 30134541 PMCID: PMC6225464 DOI: 10.3390/molecules23092094] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/17/2018] [Accepted: 08/18/2018] [Indexed: 12/28/2022] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are highly regulated proteins which respond to different cellular stimuli. The HCN currents (Ih) mediated by HCN1 and HCN2 drive the repetitive firing in nociceptive neurons. The role of HCN channels in pain has been widely investigated as targets for the development of new therapeutic drugs, but the comprehensive design of HCN channel modulators has been restricted due to the lack of crystallographic data. The three-dimensional structure of the human HCN1 channel was recently reported, opening new possibilities for the rational design of highly-selective HCN modulators. In this review, we discuss the structural and functional properties of HCN channels, their pharmacological inhibitors, and the potential strategies for designing new drugs to block the HCN channel function associated with pain perception.
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24
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Fullana MN, Ferrés-Coy A, Ortega JE, Ruiz-Bronchal E, Paz V, Meana JJ, Artigas F, Bortolozzi A. Selective Knockdown of TASK3 Potassium Channel in Monoamine Neurons: a New Therapeutic Approach for Depression. Mol Neurobiol 2018; 56:3038-3052. [PMID: 30088175 DOI: 10.1007/s12035-018-1288-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/30/2018] [Indexed: 12/25/2022]
Abstract
Current pharmacological treatments for major depressive disorder (MDD) are severely compromised by both slow action and limited efficacy. RNAi strategies have been used to evoke antidepressant-like effects faster than classical drugs. Using small interfering RNA (siRNA), we herein show that TASK3 potassium channel knockdown in monoamine neurons induces antidepressant-like responses in mice. TASK3-siRNAs were conjugated to cell-specific ligands, sertraline (Ser) or reboxetine (Reb), to promote their selective accumulation in serotonin (5-HT) and norepinephrine (NE) neurons, respectively, after intranasal delivery. Following neuronal internalization of conjugated TASK3-siRNAs, reduced TASK3 mRNA and protein levels were found in the brainstem 5-HT and NE cell groups. Moreover, Ser-TASK3-siRNA induced robust antidepressant-like behaviors, enhanced the hippocampal plasticity, and potentiated the fluoxetine-induced increase on extracellular 5-HT. Similar responses, yet of lower magnitude, were detected for Reb-TASK3-siRNA. These findings provide substantial support for TASK3 as a potential target, and RNAi-based strategies as a novel therapeutic approach to treat MDD.
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Affiliation(s)
- M Neus Fullana
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Department of Neurochemistry and Neuropharmacology, IIBB-CSIC (Consejo Superior de Investigaciones Científicas), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | - Albert Ferrés-Coy
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Department of Neurochemistry and Neuropharmacology, IIBB-CSIC (Consejo Superior de Investigaciones Científicas), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | - Jorge E Ortega
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain.,Department of Pharmacology, University of Basque Country UPV/EHU and BioCruces Health Research Institute, Bizkaia, Spain
| | - Esther Ruiz-Bronchal
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Department of Neurochemistry and Neuropharmacology, IIBB-CSIC (Consejo Superior de Investigaciones Científicas), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | - Verónica Paz
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Department of Neurochemistry and Neuropharmacology, IIBB-CSIC (Consejo Superior de Investigaciones Científicas), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | - J Javier Meana
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain.,Department of Pharmacology, University of Basque Country UPV/EHU and BioCruces Health Research Institute, Bizkaia, Spain
| | - Francesc Artigas
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Department of Neurochemistry and Neuropharmacology, IIBB-CSIC (Consejo Superior de Investigaciones Científicas), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain
| | - Analia Bortolozzi
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain. .,Department of Neurochemistry and Neuropharmacology, IIBB-CSIC (Consejo Superior de Investigaciones Científicas), Barcelona, Spain. .,Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), ISCIII, Madrid, Spain.
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25
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Srisomboon Y, Zaidman NA, Maniak PJ, Deachapunya C, O'Grady SM. P2Y receptor regulation of K2P channels that facilitate K + secretion by human mammary epithelial cells. Am J Physiol Cell Physiol 2018; 314:C627-C639. [PMID: 29365273 PMCID: PMC6008065 DOI: 10.1152/ajpcell.00342.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/17/2018] [Accepted: 01/17/2018] [Indexed: 02/07/2023]
Abstract
The objective of this study was to determine the molecular identity of ion channels involved in K+ secretion by the mammary epithelium and to examine their regulation by purinoceptor agonists. Apical membrane voltage-clamp experiments were performed on human mammary epithelial cells where the basolateral membrane was exposed to the pore-forming antibiotic amphotericin B dissolved in a solution with intracellular-like ionic composition. Addition of the Na+ channel inhibitor benzamil reduced the basal current, consistent with inhibition of Na+ uptake across the apical membrane, whereas the KCa3.1 channel blocker TRAM-34 produced an increase in current resulting from inhibition of basal K+ efflux. Treatment with two-pore potassium (K2P) channel blockers quinidine, bupivacaine and a selective TASK1/TASK3 inhibitor (PK-THPP) all produced concentration-dependent inhibition of apical K+ efflux. qRT-PCR experiments detected mRNA expression for nine K2P channel subtypes. Western blot analysis of biotinylated apical membranes and confocal immunocytochemistry revealed that at least five K2P subtypes (TWIK1, TREK1, TREK2, TASK1, and TASK3) are expressed in the apical membrane. Apical UTP also increased the current, but pretreatment with the PKC inhibitor GF109203X blocked the response. Similarly, direct activation of PKC with phorbol 12-myristate 13-acetate produced a similar increase in current as observed with UTP. These results support the conclusion that the basal level of K+ secretion involves constitutive activity of apical KCa3.1 channels and multiple K2P channel subtypes. Apical UTP evoked a transient increase in KCa3.1 channel activity, but over time caused persistent inhibition of K2P channel function leading to an overall decrease in K+ secretion.
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Affiliation(s)
| | - Nathan A Zaidman
- Departments of Animal Science, Integrative Biology, and Physiology, University of Minnesota , St. Paul, Minnesota
| | - Peter J Maniak
- Departments of Animal Science, Integrative Biology, and Physiology, University of Minnesota , St. Paul, Minnesota
| | | | - Scott M O'Grady
- Departments of Animal Science, Integrative Biology, and Physiology, University of Minnesota , St. Paul, Minnesota
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26
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Wright PD, Veale EL, McCoull D, Tickle DC, Large JM, Ococks E, Gothard G, Kettleborough C, Mathie A, Jerman J. Terbinafine is a novel and selective activator of the two-pore domain potassium channel TASK3. Biochem Biophys Res Commun 2017; 493:444-450. [DOI: 10.1016/j.bbrc.2017.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 09/01/2017] [Indexed: 12/12/2022]
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27
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Leist M, Rinné S, Datunashvili M, Aissaoui A, Pape HC, Decher N, Meuth SG, Budde T. Acetylcholine-dependent upregulation of TASK-1 channels in thalamic interneurons by a smooth muscle-like signalling pathway. J Physiol 2017; 595:5875-5893. [PMID: 28714121 DOI: 10.1113/jp274527] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/10/2017] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS The ascending brainstem transmitter acetylcholine depolarizes thalamocortical relay neurons while it induces hyperpolarization in local circuit inhibitory interneurons. Sustained K+ currents are modulated in thalamic neurons to control their activity modes; for the interneurons the molecular nature of the underlying ion channels is as yet unknown. Activation of TASK-1 K+ channels results in hyperpolarization of interneurons and suppression of their action potential firing. The modulation cascade involves a non-receptor tyrosine kinase, c-Src. The present study identifies a novel pathway for the activation of TASK-1 channels in CNS neurons that resembles cholinergic signalling and TASK-1 current modulation during hypoxia in smooth muscle cells. ABSTRACT The dorsal part of the lateral geniculate nucleus (dLGN) is the main thalamic site for state-dependent transmission of visual information. Non-retinal inputs from the ascending arousal system and inhibition provided by γ-aminobutyric acid (GABA)ergic local circuit interneurons (INs) control neuronal activity within the dLGN. In particular, acetylcholine (ACh) depolarizes thalamocortical relay neurons by inhibiting two-pore domain potassium (K2P ) channels. Conversely, ACh also hyperpolarizes INs via an as-yet-unknown mechanism. By using whole cell patch-clamp recordings in brain slices and appropriate pharmacological tools we here report that stimulation of type 2 muscarinic ACh receptors induces IN hyperpolarization by recruiting the G-protein βγ subunit (Gβγ), class-1A phosphatidylinositol-4,5-bisphosphate 3-kinase, and cellular and sarcoma (c-Src) tyrosine kinase, leading to activation of two-pore domain weakly inwardly rectifying K+ channel (TWIK)-related acid-sensitive K+ (TASK)-1 channels. The latter was confirmed by the use of TASK-1-deficient mice. Furthermore inhibition of phospholipase Cβ as well as an increase in the intracellular level of phosphatidylinositol-3,4,5-trisphosphate facilitated the muscarinic effect. Our results have uncovered a previously unknown role of c-Src tyrosine kinase in regulating IN function in the brain and identified a novel mechanism by which TASK-1 channels are activated in neurons.
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Affiliation(s)
- Michael Leist
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Susanne Rinné
- Institut für Physiologie und Pathophysiologie, AG Vegetative Physiologie, Philipps-Universität, Deutschhausstraße 1-2, D-35037, Marburg, Germany
| | - Maia Datunashvili
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Ania Aissaoui
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Hans-Christian Pape
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Niels Decher
- Institut für Physiologie und Pathophysiologie, AG Vegetative Physiologie, Philipps-Universität, Deutschhausstraße 1-2, D-35037, Marburg, Germany
| | - Sven G Meuth
- Department of Neurology, Westfälische Wilhelms-Universität, Albert-Schweitzer-Campus 1, D-48149, Münster, Germany
| | - Thomas Budde
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
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28
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Yao J, McHedlishvili D, McIntire WE, Guagliardo NA, Erisir A, Coburn CA, Santarelli VP, Bayliss DA, Barrett PQ. Functional TASK-3-Like Channels in Mitochondria of Aldosterone-Producing Zona Glomerulosa Cells. Hypertension 2017. [PMID: 28630209 DOI: 10.1161/hypertensionaha.116.08871] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ca2+ drives aldosterone synthesis in the cytosolic and mitochondrial compartments of the adrenal zona glomerulosa cell. Membrane potential across each of these compartments regulates the amplitude of the Ca2+ signal; yet, only plasma membrane ion channels and their role in regulating cell membrane potential have garnered investigative attention as pathological causes of human hyperaldosteronism. Previously, we reported that genetic deletion of TASK-3 channels (tandem pore domain acid-sensitive K+ channels) from mice produces aldosterone excess in the absence of a change in the cell membrane potential of zona glomerulosa cells. Here, we report using yeast 2-hybrid, immunoprecipitation, and electron microscopic analyses that TASK-3 channels are resident in mitochondria, where they regulate mitochondrial morphology, mitochondrial membrane potential, and aldosterone production. This study provides proof of principle that mitochondrial K+ channels, by modulating inner mitochondrial membrane morphology and mitochondrial membrane potential, have the ability to play a pathological role in aldosterone dysregulation in steroidogenic cells.
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Affiliation(s)
- Junlan Yao
- From the Departments of Pharmacology (J.Y., D.M., W.E.M., N.A.G., D.A.B., P.Q.B.) and Psychology (A.E.), University of Virginia School of Medicine, Charlottesville; Silverback Therapeutics, Inc, Seattle, WA (C.A.C.); and Department of Neuroscience, Merck & Co, Inc, West point, PA (V.P.S.)
| | - David McHedlishvili
- From the Departments of Pharmacology (J.Y., D.M., W.E.M., N.A.G., D.A.B., P.Q.B.) and Psychology (A.E.), University of Virginia School of Medicine, Charlottesville; Silverback Therapeutics, Inc, Seattle, WA (C.A.C.); and Department of Neuroscience, Merck & Co, Inc, West point, PA (V.P.S.)
| | - William E McIntire
- From the Departments of Pharmacology (J.Y., D.M., W.E.M., N.A.G., D.A.B., P.Q.B.) and Psychology (A.E.), University of Virginia School of Medicine, Charlottesville; Silverback Therapeutics, Inc, Seattle, WA (C.A.C.); and Department of Neuroscience, Merck & Co, Inc, West point, PA (V.P.S.)
| | - Nick A Guagliardo
- From the Departments of Pharmacology (J.Y., D.M., W.E.M., N.A.G., D.A.B., P.Q.B.) and Psychology (A.E.), University of Virginia School of Medicine, Charlottesville; Silverback Therapeutics, Inc, Seattle, WA (C.A.C.); and Department of Neuroscience, Merck & Co, Inc, West point, PA (V.P.S.)
| | - Alev Erisir
- From the Departments of Pharmacology (J.Y., D.M., W.E.M., N.A.G., D.A.B., P.Q.B.) and Psychology (A.E.), University of Virginia School of Medicine, Charlottesville; Silverback Therapeutics, Inc, Seattle, WA (C.A.C.); and Department of Neuroscience, Merck & Co, Inc, West point, PA (V.P.S.)
| | - Craig A Coburn
- From the Departments of Pharmacology (J.Y., D.M., W.E.M., N.A.G., D.A.B., P.Q.B.) and Psychology (A.E.), University of Virginia School of Medicine, Charlottesville; Silverback Therapeutics, Inc, Seattle, WA (C.A.C.); and Department of Neuroscience, Merck & Co, Inc, West point, PA (V.P.S.)
| | - Vincent P Santarelli
- From the Departments of Pharmacology (J.Y., D.M., W.E.M., N.A.G., D.A.B., P.Q.B.) and Psychology (A.E.), University of Virginia School of Medicine, Charlottesville; Silverback Therapeutics, Inc, Seattle, WA (C.A.C.); and Department of Neuroscience, Merck & Co, Inc, West point, PA (V.P.S.)
| | - Douglas A Bayliss
- From the Departments of Pharmacology (J.Y., D.M., W.E.M., N.A.G., D.A.B., P.Q.B.) and Psychology (A.E.), University of Virginia School of Medicine, Charlottesville; Silverback Therapeutics, Inc, Seattle, WA (C.A.C.); and Department of Neuroscience, Merck & Co, Inc, West point, PA (V.P.S.)
| | - Paula Q Barrett
- From the Departments of Pharmacology (J.Y., D.M., W.E.M., N.A.G., D.A.B., P.Q.B.) and Psychology (A.E.), University of Virginia School of Medicine, Charlottesville; Silverback Therapeutics, Inc, Seattle, WA (C.A.C.); and Department of Neuroscience, Merck & Co, Inc, West point, PA (V.P.S.).
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29
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Ramírez D, Arévalo B, Martínez G, Rinné S, Sepúlveda FV, Decher N, González W. Side Fenestrations Provide an "Anchor" for a Stable Binding of A1899 to the Pore of TASK-1 Potassium Channels. Mol Pharm 2017; 14:2197-2208. [PMID: 28494157 DOI: 10.1021/acs.molpharmaceut.7b00005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A1899 is a potent and selective inhibitor of the two-pore domain potassium (K2P) channel TASK-1. It was previously reported that A1899 acts as an open-channel blocker and binds to residues of the P1 and P2 regions, the M2 and M4 segments, and the halothane response element. The recently described crystal structures of K2P channels together with the newly identified side fenestrations indicate that residues relevant for TASK-1 inhibition are not purely facing the central cavity as initially proposed. Accordingly, the TASK-1 binding site and the mechanism of inhibition might need a re-evaluation. We have used TASK-1 homology models based on recently crystallized K2P channels and molecular dynamics simulation to demonstrate that the highly potent TASK-1 blocker A1899 requires binding to residues located in the side fenestrations. Unexpectedly, most of the previously described residues that interfere with TASK-1 blockade by A1899 project their side chains toward the fenestration lumina, underlining the relevance of these structures for drug binding in K2P channels. Despite its hydrophobicity, A1899 does not seem to use the fenestrations to gain access to the central cavity from the lipid bilayer. In contrast, binding of A1899 to residues of the side fenestrations might provide a physical "anchor", reflecting an energetically favorable binding mode that after pore occlusion stabilizes the closed state of the channels.
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Affiliation(s)
- David Ramírez
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca , 1 poniente No. 1141, 3460000 Talca, Chile.,Instituto de Ciencias Biomédicas, Universidad Autonoma de Chile , 5 Poniente No. 1670, 3460000 Talca, Chile
| | - Bárbara Arévalo
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca , 1 poniente No. 1141, 3460000 Talca, Chile
| | - Gonzalo Martínez
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca , 1 poniente No. 1141, 3460000 Talca, Chile
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology Group, University of Marburg , 35037 Marburg, Germany
| | | | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology Group, University of Marburg , 35037 Marburg, Germany
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca , 1 poniente No. 1141, 3460000 Talca, Chile
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30
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Guarina L, Vandael DHF, Carabelli V, Carbone E. Low pH o boosts burst firing and catecholamine release by blocking TASK-1 and BK channels while preserving Cav1 channels in mouse chromaffin cells. J Physiol 2017; 595:2587-2609. [PMID: 28026020 DOI: 10.1113/jp273735] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 12/07/2016] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS Mouse chromaffin cells (MCCs) generate spontaneous burst-firing that causes large increases of Ca2+ -dependent catecholamine release, and is thus a key mechanism for regulating the functions of MCCs. With the aim to uncover a physiological role for burst-firing we investigated the effects of acidosis on MCC activity. Lowering the extracellular pH (pHo ) from 7.4 to 6.6 induces cell depolarizations of 10-15 mV that generate bursts of ∼330 ms at 1-2 Hz and a 7.4-fold increase of cumulative catecholamine-release. Burst-firing originates from the inhibition of the pH-sensitive TASK-1-channels and a 60% reduction of BK-channel conductance at pHo 6.6. Blockers of the two channels (A1899 and paxilline) mimic the effects of pHo 6.6, and this is reverted by the Cav1 channel blocker nifedipine. MCCs act as pH-sensors. At low pHo , they depolarize, undergo burst-firing and increase catecholamine-secretion, generating an effective physiological response that may compensate for the acute acidosis and hyperkalaemia generated during heavy exercise and muscle fatigue. ABSTRACT Mouse chromaffin cells (MCCs) generate action potential (AP) firing that regulates the Ca2+ -dependent release of catecholamines (CAs). Recent findings indicate that MCCs possess a variety of spontaneous firing modes that span from the common 'tonic-irregular' to the less frequent 'burst' firing. This latter is evident in a small fraction of MCCs but occurs regularly when Nav1.3/1.7 channels are made less available or when the Slo1β2-subunit responsible for BK channel inactivation is deleted. Burst firing causes large increases of Ca2+ -entry and potentiates CA release by ∼3.5-fold and thus may be a key mechanism for regulating MCC function. With the aim to uncover a physiological role for burst-firing we investigated the effects of acidosis on MCC activity. Lowering the extracellular pH (pHo ) from 7.4 to 7.0 and 6.6 induces cell depolarizations of 10-15 mV that generate repeated bursts. Bursts at pHo 6.6 lasted ∼330 ms, occurred at 1-2 Hz and caused an ∼7-fold increase of CA cumulative release. Burst firing originates from the inhibition of the pH-sensitive TASK-1/TASK-3 channels and from a 40% BK channel conductance reduction at pHo 7.0. The same pHo had little or no effect on Nav, Cav, Kv and SK channels that support AP firing in MCCs. Burst firing of pHo 6.6 could be mimicked by mixtures of the TASK-1 blocker A1899 (300 nm) and BK blocker paxilline (300 nm) and could be prevented by blocking L-type channels by adding 3 μm nifedipine. Mixtures of the two blockers raised cumulative CA-secretion even more than low pHo (∼12-fold), showing that the action of protons on vesicle release is mainly a result of the ionic conductance changes that increase Ca2+ -entry during bursts. Our data provide direct evidence suggesting that MCCs respond to low pHo with sustained depolarization, burst firing and enhanced CA-secretion, thus mimicking the physiological response of CCs to acute acidosis and hyperkalaemia generated during heavy exercise and muscle fatigue.
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Affiliation(s)
- Laura Guarina
- Department of Drug Science, Laboratory of Cellular and Molecular Neuroscience, NIS Centre, CNISM Unit, Torino, Italy
| | - David H F Vandael
- Department of Drug Science, Laboratory of Cellular and Molecular Neuroscience, NIS Centre, CNISM Unit, Torino, Italy.,Present address: Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg, Austria
| | - Valentina Carabelli
- Department of Drug Science, Laboratory of Cellular and Molecular Neuroscience, NIS Centre, CNISM Unit, Torino, Italy
| | - Emilio Carbone
- Department of Drug Science, Laboratory of Cellular and Molecular Neuroscience, NIS Centre, CNISM Unit, Torino, Italy
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Abstract
Despite the epidemiological scale of atrial fibrillation, current treatment strategies are of limited efficacy and safety. Ideally, novel drugs should specifically correct the pathophysiological mechanisms responsible for atrial fibrillation with no other cardiac or extracardiac actions. Atrial-selective drugs are directed toward cellular targets with sufficiently different characteristics in atria and ventricles to modify only atrial function. Several potassium (K+) channels with either predominant expression in atria or distinct electrophysiological properties in atria and ventricles can serve as atrial-selective drug targets. These channels include the ultra-rapidly activating, delayed outward-rectifying Kv1.5 channel conducting IKur, the acetylcholine-activated inward-rectifying Kir3.1/Kir3.4 channel conducting IK,ACh, the Ca2+-activated K+ channels of small conductance (SK) conducting ISK, and the two pore domain K+ (K2P) channels TWIK-1, TASK-1 and TASK-3 that are responsible for voltage-independent background currents ITWIK-1, ITASK-1, and ITASK-3. Here, we briefly review the characteristics of these K+ channels and their roles in atrial fibrillation. The antiarrhythmic potential of drugs targeting the described channels is discussed as well as their putative value in treatment of atrial fibrillation.
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Affiliation(s)
- Ursula Ravens
- Institute of Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany; Department of Cardiology and Angiology I, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany; Department of Physiology, Medical Faculty Carl-Gustav-Carus, TU Dresden, Dresden, Germany.
| | - Katja E Odening
- Institute of Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany; Department of Cardiology and Angiology I, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany
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32
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Ramírez D. Computational Methods Applied to Rational Drug Design. THE OPEN MEDICINAL CHEMISTRY JOURNAL 2016; 10:7-20. [PMID: 27708723 PMCID: PMC5039900 DOI: 10.2174/1874104501610010007] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 01/27/2016] [Accepted: 01/28/2016] [Indexed: 11/22/2022]
Abstract
Due
to the synergic relationship between medical chemistry, bioinformatics and
molecular simulation, the development of new accurate computational tools for
small molecules drug design has been rising over the last years. The main result
is the increased number of publications where computational techniques such as
molecular docking, de novo design as well as virtual screening have been
used to estimate the binding mode, site and energy of novel small molecules. In
this work I review some tools, which enable the study of biological systems at
the atomistic level, providing relevant information and thereby, enhancing the
process of rational drug design.
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Affiliation(s)
- David Ramírez
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, 2 Norte 685, Casilla, Talca, Chile
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33
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Abstract
Atrial fibrillation (AF) is associated with increased morbidity and mortality. Atrial-selective potassium (K(+)) channel blockers may represent a novel therapeutic target. The best validated atrial-specific ion currents are the acetylcholine-activated inward-rectifier K(+) current IK,ACh and ultrarapidly activating delayed-rectifier K(+) current IKur. Two-pore domain and small-conductance Ca(2+)-activated K(+) channels and Kv1.1 channels may also contribute to the atrial repolarization. We review the molecular and electrophysiologic characteristics of atrial-selective K(+) channels and their potential pathophysiologic role in AF. We summarize currently available K(+) channel blockers focusing on the most important compounds.
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Affiliation(s)
- Niels Voigt
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Hufelandstr. 55, Essen 45122, Germany
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Hufelandstr. 55, Essen 45122, Germany.
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34
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Chokshi RH, Larsen AT, Bhayana B, Cotten JF. Breathing Stimulant Compounds Inhibit TASK-3 Potassium Channel Function Likely by Binding at a Common Site in the Channel Pore. Mol Pharmacol 2015; 88:926-34. [PMID: 26268529 DOI: 10.1124/mol.115.100107] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 08/11/2015] [Indexed: 11/22/2022] Open
Abstract
Compounds PKTHPP (1-{1-[6-(biphenyl-4-ylcarbonyl)-5,6,7,8-tetrahydropyrido[4,3-d]-pyrimidin-4-yl]piperidin-4-yl}propan-1-one), A1899 (2''-[(4-methoxybenzoylamino)methyl]biphenyl-2-carboxylic acid 2,4-difluorobenzylamide), and doxapram inhibit TASK-1 (KCNK3) and TASK-3 (KCNK9) tandem pore (K2P) potassium channel function and stimulate breathing. To better understand the molecular mechanism(s) of action of these drugs, we undertook studies to identify amino acid residues in the TASK-3 protein that mediate this inhibition. Guided by homology modeling and molecular docking, we hypothesized that PKTHPP and A1899 bind in the TASK-3 intracellular pore. To test our hypothesis, we mutated each residue in or near the predicted PKTHPP and A1899 binding site (residues 118-128 and 228-248), individually, to a negatively charged aspartate. We quantified each mutation's effect on TASK-3 potassium channel concentration response to PKTHPP. Studies were conducted on TASK-3 transiently expressed in Fischer rat thyroid epithelial monolayers; channel function was measured in an Ussing chamber. TASK-3 pore mutations at residues 122 (L122D, E, or K) and 236 (G236D) caused the IC50 of PKTHPP to increase more than 1000-fold. TASK-3 mutants L122D, G236D, L239D, and V242D were resistant to block by PKTHPP, A1899, and doxapram. Our data are consistent with a model in which breathing stimulant compounds PKTHPP, A1899, and doxapram inhibit TASK-3 function by binding at a common site within the channel intracellular pore region, although binding outside the channel pore cannot yet be excluded.
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Affiliation(s)
- Rikki H Chokshi
- Department of Anesthesia, Critical Care, and Pain Medicine (R.H.C., J.F.C.), Center for Computational and Integrative Biology, and Department of Molecular Biology (A.T.L.), and Department of Dermatology (B.B.), Massachusetts General Hospital, Boston, Massachusetts
| | - Aaron T Larsen
- Department of Anesthesia, Critical Care, and Pain Medicine (R.H.C., J.F.C.), Center for Computational and Integrative Biology, and Department of Molecular Biology (A.T.L.), and Department of Dermatology (B.B.), Massachusetts General Hospital, Boston, Massachusetts
| | - Brijesh Bhayana
- Department of Anesthesia, Critical Care, and Pain Medicine (R.H.C., J.F.C.), Center for Computational and Integrative Biology, and Department of Molecular Biology (A.T.L.), and Department of Dermatology (B.B.), Massachusetts General Hospital, Boston, Massachusetts
| | - Joseph F Cotten
- Department of Anesthesia, Critical Care, and Pain Medicine (R.H.C., J.F.C.), Center for Computational and Integrative Biology, and Department of Molecular Biology (A.T.L.), and Department of Dermatology (B.B.), Massachusetts General Hospital, Boston, Massachusetts
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35
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Zhang Y, Zhang K, Zhao M, Zhang L, Qin M, Guo S, Zhao Y, Gong P. Discovery of a novel class anti-proliferative agents and potential inhibitors of EGFR tyrosine kinases based on 4-anilinotetrahydropyrido[4,3-d]pyrimidine scaffold: Design, synthesis and biological evaluations. Bioorg Med Chem 2015; 23:4591-4607. [DOI: 10.1016/j.bmc.2015.05.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 05/29/2015] [Accepted: 05/30/2015] [Indexed: 10/23/2022]
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36
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Fluoxetine prevents respiratory arrest without enhancing ventilation in DBA/1 mice. Epilepsy Behav 2015; 45:1-7. [PMID: 25771493 PMCID: PMC4424071 DOI: 10.1016/j.yebeh.2015.02.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 02/03/2015] [Accepted: 02/04/2015] [Indexed: 11/21/2022]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is a fatal epileptic event. DBA/1 mice are a relevant animal model for the study of SUDEP, as these mice exhibit seizure-induced respiratory arrest (S-IRA) leading to death, which has been observed in patients with witnessed SUDEP. Fluoxetine, a selective serotonin (5-hydroxytryptamine or 5-HT) reuptake inhibitor (SSRI), reduces S-IRA in DBA/1 mice. Given that DBA/1 mice with S-IRA can be resuscitated using a ventilator, we hypothesized that breathing stimulants can prevent S-IRA and that fluoxetine prevents S-IRA by enhancing ventilation in these mice. Spontaneous respiratory function in anesthetized or awake DBA/1 mice was examined using noninvasive plethysmography before and after administering fluoxetine or breathing stimulants, doxapram, and 5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (PK-THPP). The effects of these drugs on S-IRA in DBA/1 mice were tested. As reported previously, systemic administration of fluoxetine reduced S-IRA in awake DBA/1 mice, but fluoxetine in anesthetized and awake DBA/1 mice did not increase basal ventilation or the ventilatory response to 7% CO2. Both doxapram and PK-THPP increased ventilation in room air and in air+7% CO2 in anesthetized DBA/1 mice. However, neither of the breathing stimulants reduced the incidence of S-IRA. Our studies confirm that fluoxetine reduces S-IRA in DBA/1 mice without enhancing basal ventilation in the absence of seizures. Although breathing stimulants increased ventilation in the absence of seizures, they were ineffective in reducing S-IRA, indicating that drug-induced increases in ventilation are insufficient to compensate for S-IRA in DBA/1 mice.
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37
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Renigunta V, Schlichthörl G, Daut J. Much more than a leak: structure and function of K₂p-channels. Pflugers Arch 2015; 467:867-94. [PMID: 25791628 DOI: 10.1007/s00424-015-1703-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 11/27/2022]
Abstract
Over the last decade, we have seen an enormous increase in the number of experimental studies on two-pore-domain potassium channels (K2P-channels). The collection of reviews and original articles compiled for this special issue of Pflügers Archiv aims to give an up-to-date summary of what is known about the physiology and pathophysiology of K2P-channels. This introductory overview briefly describes the structure of K2P-channels and their function in different organs. Its main aim is to provide some background information for the 19 reviews and original articles of this special issue of Pflügers Archiv. It is not intended to be a comprehensive review; instead, this introductory overview focuses on some unresolved questions and controversial issues, such as: Do K2P-channels display voltage-dependent gating? Do K2P-channels contribute to the generation of action potentials? What is the functional role of alternative translation initiation? Do K2P-channels have one or two or more gates? We come to the conclusion that we are just beginning to understand the extremely complex regulation of these fascinating channels, which are often inadequately described as 'leak channels'.
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Affiliation(s)
- Vijay Renigunta
- Institute of Physiology and Pathophysiology, Marburg University, 35037, Marburg, Germany
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38
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Effects of fluoxetine on protein expression of potassium ion channels in the brain of chronic mild stress rats. Acta Pharm Sin B 2015; 5:55-61. [PMID: 26579425 PMCID: PMC4629207 DOI: 10.1016/j.apsb.2014.12.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 12/05/2014] [Accepted: 12/09/2014] [Indexed: 11/23/2022] Open
Abstract
The purpose of this study is to investigate the expression of major potassium channel subtypes in the brain of chronical mild stress (CMS) rats and reveal the effects of fluoxetine on the expression of these channels. Rats were exposed to a variety of unpredictable stress for three weeks and induced anhedonia, lower sucrose preference, locomotor activity and lower body weight. The protein expressions were determined by Western blot. CMS significantly increased the expression of Kv2.1 channel in frontal cortex but not in hippocampus, and the expression level was normalized after fluoxetine treatment. The expression of TREK-1 channel was also obviously increased in frontal cortex in CMS rats. Fluoxetine treatment might prevent this increase. However, the expression of Kv3.1 and Kv4.2 channels was considerably decreased in hippocampus after CMS, and was not affected by fluoxetine. These results suggest that different subtypes of potassium channels are associated with the pathophysiology of depression and that the therapeutical effects of fluoxetine may relate to Kv2.1 and TREK-1 potassium channels.
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39
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The role of K₂p channels in anaesthesia and sleep. Pflugers Arch 2014; 467:907-16. [PMID: 25482669 PMCID: PMC4428837 DOI: 10.1007/s00424-014-1654-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/11/2014] [Accepted: 11/12/2014] [Indexed: 12/20/2022]
Abstract
Tandem two-pore potassium channels (K2Ps) have widespread expression in the central nervous system and periphery where they contribute to background membrane conductance. Some general anaesthetics promote the opening of some of these channels, enhancing potassium currents and thus producing a reduction in neuronal excitability that contributes to the transition to unconsciousness. Similarly, these channels may be recruited during the normal sleep-wake cycle as downstream effectors of wake-promoting neurotransmitters such as noradrenaline, histamine and acetylcholine. These transmitters promote K2P channel closure and thus an increase in neuronal excitability. Our understanding of the roles of these channels in sleep and anaesthesia has been largely informed by the study of mouse K2P knockout lines and what is currently predicted by in vitro electrophysiology and channel structure and gating.
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40
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Borsotto M, Veyssiere J, Moha Ou Maati H, Devader C, Mazella J, Heurteaux C. Targeting two-pore domain K(+) channels TREK-1 and TASK-3 for the treatment of depression: a new therapeutic concept. Br J Pharmacol 2014; 172:771-84. [PMID: 25263033 DOI: 10.1111/bph.12953] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/20/2014] [Accepted: 09/22/2014] [Indexed: 12/17/2022] Open
Abstract
Depression is a disease that is particularly frequent, affecting up to 20% of the population in Western countries. The origins of this pathology involve multiple genes as well as environmental and developmental factors leading to a disorder that remains difficult to treat. Several therapies for depression have been developed and these mainly target monoamine neurotransmitters. However, these treatments are not only associated with numerous adverse effects, but they are also ineffective for more than one-third of patients. Therefore, the need to develop new concepts to treat depression is crucial. Recently, studies using knockout mouse models have provided evidence for a crucial role of two members of the two-pore domain potassium channel (K2P ) family, tandem P-domain weak inward rectifying K(+) (TWIK)-related K(+) channel 1 (TREK-1) and TWIK-related acid-sensitive K(+) channel 3 (TASK-3) in the pathophysiology of depression. It is believed that TREK-1 and TASK-3 antagonists could lead to the development of new antidepressants. Herein, we describe the discovery of spadin, a natural peptide released from the maturation of the neurotensin receptor-3 (also known as sortilin), which specifically blocks the activity of the TREK-1 channel and displays particular antidepressant properties, with a rapid onset of action and the absence of adverse effects. The development of such molecules may open a new era in the field of psychiatry.
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Affiliation(s)
- M Borsotto
- Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique (CNRS) UMR 7275, Université Nice Sophia Antipolis, Valbonne, France
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41
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Nagy D, Gönczi M, Dienes B, Szöőr Á, Fodor J, Nagy Z, Tóth A, Fodor T, Bai P, Szücs G, Rusznák Z, Csernoch L. Silencing the KCNK9 potassium channel (TASK-3) gene disturbs mitochondrial function, causes mitochondrial depolarization, and induces apoptosis of human melanoma cells. Arch Dermatol Res 2014; 306:885-902. [PMID: 25318378 DOI: 10.1007/s00403-014-1511-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 07/24/2014] [Accepted: 09/29/2014] [Indexed: 01/12/2023]
Abstract
TASK-3 (KCNK9 or K2P9.1) channels are thought to promote proliferation and/or survival of malignantly transformed cells, most likely by increasing their hypoxia tolerance. Based on our previous results that suggested mitochondrial expression of TASK-3 channels, we hypothesized that TASK-3 channels have roles in maintaining mitochondrial activity. In the present work we studied the effect of reduced TASK-3 expression on the mitochondrial function and survival of WM35 and A2058 melanoma cells. TASK-3 knockdown cells had depolarized mitochondrial membrane potential and contained a reduced amount of mitochondrial DNA. Compared to their scrambled shRNA-transfected counterparts, they demonstrated diminished responsiveness to the application of the mitochondrial uncoupler [(3-chlorophenyl)hydrazono]malononitrile (CCCP). These observations indicate impaired mitochondrial function. Further, TASK-3 knockdown cells presented reduced viability, decreased total DNA content, altered cell morphology, and reduced surface area. In contrast to non- and scrambled shRNA-transfected melanoma cell lines, which did not present noteworthy apoptotic activity, almost 50 % of the TASK-3 knockdown cells exhibited strong Annexin-V-specific immunofluorescence signal. Sequestration of cytochrome c from the mitochondria to the cytosol, increased caspase 3 activity, and translocation of the apoptosis-inducing factor from mitochondria to cell nuclei were also demonstrated in TASK-3 knockdown cells. Interference with TASK-3 channel expression, therefore, induces caspase-dependent and -independent apoptosis of melanoma cells, most likely via causing mitochondrial depolarization. Consequently, TASK-3 channels may be legitimate targets of future melanoma therapies.
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Affiliation(s)
- Dénes Nagy
- Department of Physiology, Faculty of General Medicine, University of Debrecen, Nagyerdei krt 98, PO Box 22, 4012, Debrecen, Hungary
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42
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Morenilla-Palao C, Luis E, Fernández-Peña C, Quintero E, Weaver JL, Bayliss DA, Viana F. Ion channel profile of TRPM8 cold receptors reveals a role of TASK-3 potassium channels in thermosensation. Cell Rep 2014; 8:1571-82. [PMID: 25199828 DOI: 10.1016/j.celrep.2014.08.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 06/09/2014] [Accepted: 08/01/2014] [Indexed: 10/24/2022] Open
Abstract
Animals sense cold ambient temperatures through the activation of peripheral thermoreceptors that express TRPM8, a cold- and menthol-activated ion channel. These receptors can discriminate a very wide range of temperatures from innocuous to noxious. The molecular mechanism responsible for the variable sensitivity of individual cold receptors to temperature is unclear. To address this question, we performed a detailed ion channel expression analysis of cold-sensitive neurons, combining bacterial artificial chromosome (BAC) transgenesis with a molecular-profiling approach in fluorescence-activated cell sorting (FACS)-purified TRPM8 neurons. We found that TASK-3 leak potassium channels are highly enriched in a subpopulation of these sensory neurons. The thermal threshold of TRPM8 cold neurons is decreased during TASK-3 blockade and in mice lacking TASK-3, and, most importantly, these mice display hypersensitivity to cold. Our results demonstrate a role of TASK-3 channels in thermosensation, showing that a channel-based combinatorial strategy in TRPM8 cold thermoreceptors leads to molecular specialization and functional diversity.
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Affiliation(s)
- Cruz Morenilla-Palao
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 San Juan de Alicante, Spain.
| | - Enoch Luis
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 San Juan de Alicante, Spain
| | - Carlos Fernández-Peña
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 San Juan de Alicante, Spain
| | - Eva Quintero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 San Juan de Alicante, Spain
| | - Janelle L Weaver
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Félix Viana
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 San Juan de Alicante, Spain.
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43
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Potent and selective inhibitors of the TASK-1 potassium channel through chemical optimization of a bis-amide scaffold. Bioorg Med Chem Lett 2014; 24:3968-73. [PMID: 25017033 DOI: 10.1016/j.bmcl.2014.06.032] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 06/09/2014] [Accepted: 06/11/2014] [Indexed: 01/10/2023]
Abstract
TASK-1 is a two-pore domain potassium channel that is important to modulating cell excitability, most notably in the context of neuronal pathways. In order to leverage TASK-1 for therapeutic benefit, its physiological role needs better characterization; however, designing selective inhibitors that avoid the closely related TASK-3 channel has been challenging. In this study, a series of bis-amide derived compounds were found to demonstrate improved TASK-1 selectivity over TASK-3 compared to reported inhibitors. Optimization of a marginally selective hit led to analog 35 which displays a TASK-1 IC50=16 nM with 62-fold selectivity over TASK-3 in an orthogonal electrophysiology assay.
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44
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Grace KP, Hughes SW, Horner RL. Identification of a pharmacological target for genioglossus reactivation throughout sleep. Sleep 2014; 37:41-50. [PMID: 24470694 DOI: 10.5665/sleep.3304] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Obstructive sleep apnea (OSA) is a significant public health problem caused by repeated episodes of upper airway closure that occur only during sleep. Attempts to treat OSA pharmacologically have been unsuccessful because there has not been identification of a target operating at cranial motor nuclei, blockade of which can reactivate pharyngeal muscle activity throughout sleep. Increasing potassium conductance is a common mechanism by which state-dependent neuromodulators reduce motoneuron excitability. Therefore, we aimed to determine if potassium channel blockade is an effective strategy to reactivate the pharyngeal musculature throughout sleep. DESIGN PARTICIPANTS AND INTERVENTIONS In rats chronically instrumented for recording sleep-wake states and respiratory motor activities, we locally microperfused pharmacological agents into the hypoglossal motor pool to modulate potassium channels of three major classes: inwardly rectifying, two-pore domain, and voltage-gated. MEASUREMENTS AND RESULTS Microperfusion of the inwardly rectifying potassium channel blocker, barium, as well as the voltage-gated potassium channel blockers, tetraethylammonium and 4-aminopyridine, increased tonic and respiratory-related genioglossus activities throughout nonrapid eye movement (non-REM) and rapid eye movement (REM) sleep to 133-300% of levels present during baseline wakefulness. In contrast, microperfusion of methanandamide (TWIK-related acid-sensitive potassium [TASK] channel blocker/cannabinoid receptor agonist) activated genioglossus in wakefulness but not in sleep. CONCLUSIONS These findings establish proof-of-principle that targeted blockade of certain potassium channels at the hypoglossal motor pool is an effective strategy for reversing upper airway hypotonia and causing sustained reactivation of genioglossus throughout nonrapid eye movement and rapid eye movement sleep. These findings identify an important new direction for translational approaches to the pharmacological treatment of obstructive sleep apnea.
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Affiliation(s)
- Kevin P Grace
- Department of Medicine, University of Toronto, Toronto, Canada
| | - Stuart W Hughes
- Eli Lilly, Erl Wood Manor, Windlesham, Surrey, United Kingdom
| | - Richard L Horner
- Department of Medicine, University of Toronto, Toronto, Canada ; Department of Physiology, University of Toronto, Toronto, Canada
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45
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Noriega-Navarro R, Lopez-Charcas O, Hernández-Enríquez B, Reyes-Gutiérrez PE, Martínez R, Landa A, Morán J, Gomora JC, Garcia-Valdes J. Novel TASK channels inhibitors derived from dihydropyrrolo[2,1-a]isoquinoline. Neuropharmacology 2013; 79:28-36. [PMID: 24212057 DOI: 10.1016/j.neuropharm.2013.10.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 10/22/2013] [Accepted: 10/27/2013] [Indexed: 01/12/2023]
Abstract
TASK channels belong to the family of K(+) channels with 4 transmembrane segments and 2 pore domains (4TM/2P) per subunit. These channels have been related to apoptosis in cerebellar granule neurons (CGN), as well as cancer in other tissues. TASK current is regulated by hormones, neurotransmitters, anesthetics and divalent cations, which are not selective. Recently, there has been found some organic compounds that inhibit TASK current selectively. In order to find other modulators, we report here a group of five dihydropyrrolo[2,1-a]isoquinolines (DPIs), four of them with putative anticancer activity, that were evaluated on TASK-1 and TASK-3 channels. The compounds 1, 2 and 3 showed IC50 < 320 μM on TASK-1 and TASK-3, intermediate activity on TASK-1/TASK-3 heterodimer, moderate effect over hslo and TREK-1 (500 μM), and practically not inhibition on Shaker-IR, herg and IRK2.1 potassium channels, when they were expressed heterologously in Xenopus laevis oocytes. In rat CGN, 500 μM of these three compounds induced a decrement by >39% of the TASK-carried leak current. Finally, only compound 1 showed significant protection (∼36%) against apoptotic death of CGN induced by K(+) deprivation. These results suggest that DPI compounds could be potential candidates for designing new selective inhibitors of TASK channels.
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Affiliation(s)
- R Noriega-Navarro
- Departamento de Química Analítica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - O Lopez-Charcas
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - B Hernández-Enríquez
- Departamento de Neurodesarrollo y Fisiología, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - P E Reyes-Gutiérrez
- Departamento de Química Orgánica, Instituto de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - R Martínez
- Departamento de Química Orgánica, Instituto de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - A Landa
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - J Morán
- Departamento de Neurodesarrollo y Fisiología, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - J C Gomora
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - J Garcia-Valdes
- Departamento de Química Analítica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico.
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Robinson RP, Casimiro-Garcia A, Liang S, Anderson DP, Flick AC. A tandem hetero Diels–Alder/Mannich approach for the synthesis of a versatile hexahydro-2H-pyrano[3,2-c]pyridin-4(3H)-one core. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.08.105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Grace KP, Hughes SW, Shahabi S, Horner RL. K+ channel modulation causes genioglossus inhibition in REM sleep and is a strategy for reactivation. Respir Physiol Neurobiol 2013; 188:277-88. [PMID: 23872455 DOI: 10.1016/j.resp.2013.07.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 07/10/2013] [Accepted: 07/11/2013] [Indexed: 12/23/2022]
Abstract
Rapid eye movement (REM) sleep is accompanied by periods of upper airway motor suppression that cause hypoventilation and obstructive apneas in susceptible individuals. A common idea has been that upper airway motor suppression in REM sleep is caused by the neurotransmitters glycine and γ-amino butyric acid (GABA) acting at pharyngeal motor pools to inhibit motoneuron activity. Data refute this as a workable explanation because blockade of this putative glycine/GABAergic mechanism releases pharyngeal motor activity in all states, and least of all in REM sleep. Here we summarize a novel motor-inhibitory mechanism that suppresses hypoglossal motor activity largely in REM sleep, this being a muscarinic receptor mechanism linked to G-protein-coupled inwardly rectifying potassium (GIRK) channels. We then outline how this discovery informs efforts to pursue therapeutic targets to reactivate hypoglossal motor activity throughout sleep via potassium channel modulation. One such target is the inwardly rectifying potassium channel Kir2.4 whose expression in the brain is almost exclusive to cranial motor nuclei.
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Affiliation(s)
- Kevin P Grace
- Departments of Medicine, University of Toronto, Toronto, ON, Canada M5S 1A8
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Inside job: ligand-receptor pharmacology beneath the plasma membrane. Acta Pharmacol Sin 2013; 34:859-69. [PMID: 23685953 PMCID: PMC3703709 DOI: 10.1038/aps.2013.51] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 04/07/2013] [Indexed: 12/24/2022] Open
Abstract
Most drugs acting on the cell surface receptors are membrane permeable and thus able to engage their target proteins in different subcellular compartments. However, these drugs' effects on cell surface receptors have historically been studied on the plasma membrane alone. Increasing evidence suggests that small molecules may also modulate their targeted receptors through membrane trafficking or organelle-localized signaling inside the cell. These additional modes of interaction have been reported for functionally diverse ligands of GPCRs, ion channels, and transporters. Such intracellular drug-target engagements affect cell surface expression. Concurrent intracellular and cell surface signaling may also increase the complexity and therapeutic opportunities of small molecule modulation. Here we discuss examples of ligand-receptor interactions that are present in both intra- and extracellular sites, and the potential therapeutic opportunities presented by this phenomenon.
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TASK-1 (KCNK3) and TASK-3 (KCNK9) tandem pore potassium channel antagonists stimulate breathing in isoflurane-anesthetized rats. Anesth Analg 2013; 116:810-6. [PMID: 23460565 DOI: 10.1213/ane.0b013e318284469d] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND TASK-1 and TASK-3 tandem pore potassium channel subunits provide a constitutive acidic pH- and hypoxia-inhibited potassium conductance. TASK channels are expressed in a number of tissues involved in regulation of breathing, and the TASK-1/TASK-3 heterodimer provides the predominant hypoxia-sensitive potassium conductance in carotid body type 1 glomus chemosensing cells. The carotid bodies have an important role in regulation of breathing. Doxapram is a potent TASK-1 and TASK-3 potassium channel antagonist and a carotid body and breathing stimulant. PK-THPP and A1899 are potent and selective TASK-1 and TASK-3 antagonists. I hypothesized PK-THPP and A1899 are, like doxapram, breathing stimulants. METHODS I studied rat TASK-3 potassium channel function by Ussing chamber using Fischer rat thyroid monolayers. To quantify breathing effects, I studied male Sprague-Dawley rats spontaneously breathing 1.5% isoflurane in room air by noninvasive plethysmography and by arterial blood gas analysis. RESULTS PK-THPP, A1899, and doxapram inhibit rat TASK-3 potassium channel function with IC50s of 42 nM (33-52), 1.6 μM (0.8-3.3), and 22 μM (18-28) (n = 4-6; 95% confidence limits). IV PK-THPP, A1899, and doxapram stimulated breathing by plethysmography with a peak change in minute ventilation relative to baseline of 84% ± 19% and 226% ± 56% (for PK-THPP at 0.5 and 5 mg/kg; mean ± SEM; n = 3-4; P < 0.05 and P < 0.001, respectively, relative to vehicle); 46% ± 2% and 236% ± 48% (for A1899 at 5 and 25 mg/kg; n = 3-4; P > 0.05 and P < 0.001, respectively); 103% ± 20% (for doxapram at 25 mg/kg; n = 4), and 33% ± 9% (for dimethylsulfoxide vehicle at 1 mL/kg; n = 4). PK-THPP and A1899, unlike doxapram, induced a profound and lasting respiratory alkalosis by arterial blood gas analysis. Thirty minutes after IV drug administration, I observed an arterial pH and carbon dioxide partial pressure of 7.62 ± 0.02 and 23 ± 0.8 mm Hg (for PK-THPP after 5 mg/kg; n = 4; P < 0.001 for both relative to vehicle), 7.49 ± 0.02 and 31 ± 2 mm Hg (for A1899 at 25 mg/kg; n = 6; P < 0.05 and 0.001, respectively), 7.43 ± 0.03 and 39 ± 4 mm Hg (for doxapram after 25 mg/kg; n = 4; P > 0.05 for both), and 7.38 ± 0.03 and 48 ± 4 mm Hg (for dimethylsulfoxide vehicle after 1 mL/kg; n = 3). CONCLUSIONS PK-THPP and A1899 are potent rat TASK-3 antagonists and effective breathing stimulants. PK-THPP and A1899 effects on breathing were of greater magnitude and/or duration relative to that of doxapram. PK-THPP and A1899 or related compounds may have therapeutic potential for treating breathing disorders.
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Bagal SK, Brown AD, Cox PJ, Omoto K, Owen RM, Pryde DC, Sidders B, Skerratt SE, Stevens EB, Storer RI, Swain NA. Ion Channels as Therapeutic Targets: A Drug Discovery Perspective. J Med Chem 2012; 56:593-624. [DOI: 10.1021/jm3011433] [Citation(s) in RCA: 198] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sharan K. Bagal
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park,
Great Abington, Cambridge, CB21 6GS, U.K
| | - Alan D. Brown
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park,
Great Abington, Cambridge, CB21 6GS, U.K
| | - Peter J. Cox
- Pfizer Neusentis, The
Portway Building, Granta Park, Great Abington, Cambridge, CB21
6GS, U.K
| | - Kiyoyuki Omoto
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park,
Great Abington, Cambridge, CB21 6GS, U.K
| | - Robert M. Owen
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park,
Great Abington, Cambridge, CB21 6GS, U.K
| | - David C. Pryde
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park,
Great Abington, Cambridge, CB21 6GS, U.K
| | - Benjamin Sidders
- Pfizer Neusentis, The
Portway Building, Granta Park, Great Abington, Cambridge, CB21
6GS, U.K
| | - Sarah E. Skerratt
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park,
Great Abington, Cambridge, CB21 6GS, U.K
| | - Edward B. Stevens
- Pfizer Neusentis, The
Portway Building, Granta Park, Great Abington, Cambridge, CB21
6GS, U.K
| | - R. Ian Storer
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park,
Great Abington, Cambridge, CB21 6GS, U.K
| | - Nigel A. Swain
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park,
Great Abington, Cambridge, CB21 6GS, U.K
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