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Mirlohi S, Bladen C, Santiago MJ, Arnold JC, McGregor I, Connor M. Inhibition of human recombinant T-type calcium channels by phytocannabinoids in vitro. Br J Pharmacol 2022; 179:4031-4043. [PMID: 35342937 DOI: 10.1111/bph.15842] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/07/2022] [Accepted: 03/09/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE T-type Ca channels (ICa ) regulate neuronal excitability and contribute to neurotransmitter release. The phytocannabinoids Δ9 -tetrahydrocannabinol and cannabidiol effectively modulate T-type ICa , but effects of other biologically active phytocannabinoids on these channels are unknown. We thus investigated the modulation of T-type ICa by low abundance phytocannabinoids. EXPERIMENTAL APPROACH A fluorometric (FLIPR) assay was used to investigate modulation of human T-type ICa (CaV 3.1, 3.2 and 3.3) stably expressed in FlpIn-TREx HEK293 cells. The biophysical effects of some compounds were examined using whole-cell patch clamp recordings from the same cells. KEY RESULTS In the FLIPR assay, all eleven phytocannabinoids tested modulated T-type ICa , with most inhibiting CaV 3.1 and CaV 3.2 more effectively than CaV 3.3. Cannabigerolic acid was the most potent inhibitor of CaV 3.1 (pIC50 6.1 ± 0.6) and CaV 3.2 (pIC50 6.4 ± 0.4); in all cases phytocannabinoid acids were more potent than their corresponding neutral forms. In patch clamp recordings, cannabigerolic acid inhibited CaV 3.1 and 3.2 with similar potency to the FLIPR assay, the inhibition was associated with significant hyperpolarizing shift in activation and steady state inactivation of these channels. In contrast, cannabidiol, cannabidivarin and cannabigerol only affected channel inactivation. CONCLUSION AND IMPLICATIONS Modulation of T-type calcium channels is a common property of phytocannabinoids, which all increase steady state inactivation at physiological membrane potentials, with some also affecting channel activation. Thus, T-type ICa may be a common site of action for phytocannabinoids, and the diverse actions of phytocannabinoids on channel gating may provide insight into structural requirement for selective T-type ICa modulators.
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Affiliation(s)
- Somayeh Mirlohi
- Department of Biomedical Sciences, Faculty of Medicine Health and Human Sciences, Macquarie University, Sydney
| | - Chris Bladen
- Department of Biomedical Sciences, Faculty of Medicine Health and Human Sciences, Macquarie University, Sydney
| | - Marina J Santiago
- Department of Biomedical Sciences, Faculty of Medicine Health and Human Sciences, Macquarie University, Sydney
| | - Jonathon C Arnold
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.,Discipline of Pharmacology, Sydney Pharmacy School, The University of Sydney, Sydney, New South Wales, Australia
| | - Ian McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia
| | - Mark Connor
- Department of Biomedical Sciences, Faculty of Medicine Health and Human Sciences, Macquarie University, Sydney
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Zhang YL, Moran SP, Allen A, Baez-Nieto D, Xu Q, Wang LA, Martenis WE, Sacher JR, Gale JP, Weïwer M, Wagner FF, Pan JQ. Novel Fluorescence-Based High-Throughput FLIPR Assay Utilizing Membrane-Tethered Genetic Calcium Sensors to Identify T-Type Calcium Channel Modulators. ACS Pharmacol Transl Sci 2022; 5:156-168. [PMID: 35311021 PMCID: PMC8923061 DOI: 10.1021/acsptsci.1c00233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Indexed: 11/28/2022]
Abstract
T-type voltage-gated Ca2+ channels have been implicated in many human disorders, and there has been increasing interest in developing highly selective and potent T-type Ca2+ channel modulators for potential clinical use. However, the unique biophysical properties of T-type Ca2+ channels are not conducive for developing high-throughput screening (HTS) assays to identify modulators, particularly potentiators. To illustrate, T-type Ca2+ channels are largely inactivated and unable to open to allow Ca2+ influx at -25 mV, the typical resting membrane potential of the cell lines commonly used in cellular screening assays. To address this issue, we developed cell lines that express Kir2.3 channels to hyperpolarize the membrane potential to -70 mV, thus allowing T-type channels to return to their resting state where they can be subsequently activated by membrane depolarization in the presence of extracellular KCl. Furthermore, to simplify the HTS assay and to reduce reagent cost, we stably expressed a membrane-tethered genetic calcium sensor, GCaMP6s-CAAX, that displays superior signal to the background compared to the untethered GCaMP6s or the synthetic Ca2+ sensor Fluo-4AM. Here, we describe a novel GCaMP6s-CAAX-based calcium assay utilizing a high-throughput fluorometric imaging plate reader (Molecular Devices, Sunnyvale, CA) format that can identify both activators and inhibitors of T-type Ca2+ channels. Lastly, we demonstrate the utility of this novel fluorescence-based assay to evaluate the activities of two distinct G-protein-coupled receptors, thus expanding the use of GCaMP6s-CAAX to a wide range of applications relevant for developing cellular assays in drug discovery.
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High-Throughput Fluorescence Assays for Ion Channels and GPCRs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:27-72. [DOI: 10.1007/978-3-030-12457-1_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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4
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Wang D, Ragnarsson L, Lewis RJ. T-type Calcium Channels in Health and Disease. Curr Med Chem 2018; 27:3098-3122. [PMID: 30277145 DOI: 10.2174/0929867325666181001112821] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/28/2018] [Accepted: 08/30/2018] [Indexed: 12/12/2022]
Abstract
Low Voltage-Activated (LVA) T-type calcium channels are characterized by transient current and Low Threshold Spikes (LTS) that trigger neuronal firing and oscillatory behavior. Combined with their preferential localization in dendrites and their specific "window current", T-type calcium channels are considered to be key players in signal amplification and synaptic integration. Assisted by the emerging pharmacological tools, the structural determinants of channel gating and kinetics, as well as novel physiological and pathological functions of T-type calcium channels, are being uncovered. In this review, we provide an overview of structural determinants in T-type calcium channels, their involvement in disorders and diseases, the development of novel channel modulators, as well as Structure-Activity Relationship (SAR) studies that lead to rational drug design.
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Affiliation(s)
- Dan Wang
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, the University of Queensland, Brisbane Qld 4072, Australia
| | - Lotten Ragnarsson
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, the University of Queensland, Brisbane Qld 4072, Australia
| | - Richard J Lewis
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, the University of Queensland, Brisbane Qld 4072, Australia
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5
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Bezençon O, Heidmann B, Siegrist R, Stamm S, Richard S, Pozzi D, Corminboeuf O, Roch C, Kessler M, Ertel EA, Reymond I, Pfeifer T, de Kanter R, Toeroek-Schafroth M, Moccia LG, Mawet J, Moon R, Rey M, Capeleto B, Fournier E. Discovery of a Potent, Selective T-type Calcium Channel Blocker as a Drug Candidate for the Treatment of Generalized Epilepsies. J Med Chem 2017; 60:9769-9789. [PMID: 29116786 DOI: 10.1021/acs.jmedchem.7b01236] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We report here the discovery and pharmacological characterization of N-(1-benzyl-1H-pyrazol-3-yl)-2-phenylacetamide derivatives as potent, selective, brain-penetrating T-type calcium channel blockers. Optimization focused mainly on solubility, brain penetration, and the search for an aminopyrazole metabolite that would be negative in an Ames test. This resulted in the preparation and complete characterization of compound 66b (ACT-709478), which has been selected as a clinical candidate.
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Affiliation(s)
- Olivier Bezençon
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Bibia Heidmann
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Romain Siegrist
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Simon Stamm
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Sylvia Richard
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Davide Pozzi
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Olivier Corminboeuf
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Catherine Roch
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Melanie Kessler
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Eric A Ertel
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Isabelle Reymond
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Thomas Pfeifer
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Ruben de Kanter
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Michael Toeroek-Schafroth
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Luca G Moccia
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Jacques Mawet
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Richard Moon
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Markus Rey
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Bruno Capeleto
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
| | - Elvire Fournier
- Chemistry, Biology and Pharmacology & Pre-clinical Development, Drug Discovery, Idorsia Pharmaceuticals Ltd. , Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
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6
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Cain SM, Garcia E, Waheed Z, Jones KL, Bushell TJ, Snutch TP. GABA B receptors suppress burst-firing in reticular thalamic neurons. Channels (Austin) 2017; 11:574-586. [PMID: 28742985 DOI: 10.1080/19336950.2017.1358836] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Burst-firing in thalamic neurons is known to play a key role in mediating thalamocortical (TC) oscillations that are associated with non-REM sleep and some types of epileptic seizure. Within the TC system the primary output of GABAergic neurons in the reticular thalamic nucleus (RTN) is thought to induce the de-inactivation of T-type calcium channels in thalamic relay (TR) neurons, promoting burst-firing drive to the cortex and the propagation of TC network activity. However, RTN neurons also project back onto other neurons within the RTN. The role of this putative negative feedback upon the RTN itself is less well understood, although is hypothesized to induce de-synchronization of RTN neuron firing leading to the suppression of TC oscillations. Here we tested two hypotheses concerning possible mechanisms underlying TC oscillation modulation. Firstly, we assessed the burst-firing behavior of RTN neurons in response to GABAB receptor activation using acute brain slices. The selective GABAB receptor agonist baclofen was found to induce suppression of burst-firing concurrent with effects on membrane input resistance. Secondly, RTN neurons express CaV3.2 and CaV3.3 T-type calcium channel isoforms known to contribute toward TC burst-firing and we examined the modulation of these channels by GABAB receptor activation. Utilizing exogenously expressed T-type channels we assessed whether GABAB receptor activation could directly alter T-type calcium channel properties. Overall, GABAB receptor activation had only modest effects on CaV3.2 and CaV3.3 isoforms. The only effect that could be predicted to suppress burst-firing was a hyperpolarized shift in the voltage-dependence of inactivation, potentially causing lower channel availability at membrane potentials critical for burst-firing. Conversely, other effects observed such as a hyperpolarized shift in the voltage-dependence of activation of both CaV3.2 and CaV3.3 as well as increased time constant of activation of the CaV3.3 isoform would be expected to enhance burst-firing. Together, we hypothesize that GABAB receptor activation mediates multiple downstream effectors that combined act to suppress burst-firing within the RTN. It appears unlikely that direct GABAB receptor-mediated modulation of T-type calcium channels is the major mechanistic contributor to this suppression.
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Affiliation(s)
- Stuart M Cain
- a Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health , University of British Columbia , Vancouver , Canada
| | - Esperanza Garcia
- a Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health , University of British Columbia , Vancouver , Canada
| | - Zeina Waheed
- a Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health , University of British Columbia , Vancouver , Canada
| | - Karen L Jones
- a Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health , University of British Columbia , Vancouver , Canada
| | - Trevor J Bushell
- b Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde , Glasgow , UK
| | - Terrance P Snutch
- a Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health , University of British Columbia , Vancouver , Canada
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7
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Bertrand D, Biton B, Licher T, Chambard JM, Lanneau C, Partiseti M, Lefevre IA. Functional Studies of Sodium Channels: From Target to Compound Identification. ACTA ACUST UNITED AC 2016; 75:9.21.1-9.21.35. [PMID: 27960031 DOI: 10.1002/cpph.14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Over the last six decades, voltage-gated sodium (Nav ) channels have attracted a great deal of scientific and pharmaceutical interest, driving fundamental advances in both biology and technology. The structure and physiological function of these channels have been extensively studied; clinical and genetic data have uncovered their implication in diseases such as epilepsy, arrhythmias, and pain, bringing them into focus as current and future drug targets. While different techniques have been established to record the activity of Nav channels, proper determination of their properties still presents serious challenges, depending upon the experimental conditions and the desired subtype of channel to be characterized. The aim of this unit is to review the characteristics of Nav channels, their properties, the cells in which they can be studied, and the currently available techniques. Topics covered include the determination of Nav -channel biophysical properties as well as the use of toxins to discriminate between subtypes using electrophysiological or optical methods. Perspectives on the development of high-throughput screening assays with their advantages and limitations are also discussed to allow a better understanding of the challenges encountered in voltage-gated sodium channel preclinical drug discovery. © 2016 by John Wiley & Sons, Inc.
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8
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Therapeutic potential of RQ-00311651, a novel T-type Ca2+ channel blocker, in distinct rodent models for neuropathic and visceral pain. Pain 2016; 157:1655-1665. [DOI: 10.1097/j.pain.0000000000000565] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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9
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High throughput screening technologies for ion channels. Acta Pharmacol Sin 2016; 37:34-43. [PMID: 26657056 DOI: 10.1038/aps.2015.108] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 10/12/2015] [Indexed: 11/08/2022] Open
Abstract
Ion channels are involved in a variety of fundamental physiological processes, and their malfunction causes numerous human diseases. Therefore, ion channels represent a class of attractive drug targets and a class of important off-targets for in vitro pharmacological profiling. In the past decades, the rapid progress in developing functional assays and instrumentation has enabled high throughput screening (HTS) campaigns on an expanding list of channel types. Chronologically, HTS methods for ion channels include the ligand binding assay, flux-based assay, fluorescence-based assay, and automated electrophysiological assay. In this review we summarize the current HTS technologies for different ion channel classes and their applications.
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10
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Zamponi GW. Targeting voltage-gated calcium channels in neurological and psychiatric diseases. Nat Rev Drug Discov 2015; 15:19-34. [DOI: 10.1038/nrd.2015.5] [Citation(s) in RCA: 254] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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11
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Zhang H, Zou B, Du F, Xu K, Li M. Reporting sodium channel activity using calcium flux: pharmacological promiscuity of cardiac Nav1.5. Mol Pharmacol 2014; 87:207-17. [PMID: 25422141 DOI: 10.1124/mol.114.094789] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Voltage-gated sodium (Nav) channels are essential for membrane excitability and represent therapeutic targets for treating human diseases. Recent reports suggest that these channels, e.g., Nav1.3 and Nav1.5, are inhibited by multiple structurally distinctive small molecule drugs. These studies give reason to wonder whether these drugs collectively target a single site or multiple sites in manifesting such pharmacological promiscuity. We thus investigate the pharmacological profile of Nav1.5 through systemic analysis of its sensitivity to diverse compound collections. Here, we report a dual-color fluorescent method that exploits a customized Nav1.5 [calcium permeable Nav channel, subtype 5 (SoCal5)] with engineered-enhanced calcium permeability. SoCal5 retains wild-type (WT) Nav1.5 pharmacological profiles. WT SoCal5 and SoCal5 with the local anesthetics binding site mutated (F1760A) could be expressed in separate cells, each with a different-colored genetically encoded calcium sensor, which allows a simultaneous report of compound activity and site dependence. The pharmacological profile of SoCal5 reveals a hit rate (>50% inhibition) of around 13% at 10 μM, comparable to that of hERG. The channel activity is susceptible to blockage by known drugs and structurally diverse compounds. The broad inhibition profile is highly dependent on the F1760 residue in the inner cavity, which is a residue conserved among all nine subtypes of Nav channels. Both promiscuity and dependence on F1760 seen in Nav1.5 were replicated in Nav1.4. Our evidence of a broad inhibition profile of Nav channels suggests a need to consider off-target effects on Nav channels. The site-dependent promiscuity forms a foundation to better understand Nav channels and compound interactions.
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Affiliation(s)
- Hongkang Zhang
- The Solomon H. Snyder Department of Neuroscience, High Throughput Biology Center (H.Z., B.Z., F.D., K.X., M.L.); Johns Hopkins Ion Channel Center (H.Z., B.Z., F.D., K.X., M.L.), Johns Hopkins University, Baltimore, Maryland; and GlaxoSmithKline, King of Prussia, Pennsylvania (M.L.)
| | - Beiyan Zou
- The Solomon H. Snyder Department of Neuroscience, High Throughput Biology Center (H.Z., B.Z., F.D., K.X., M.L.); Johns Hopkins Ion Channel Center (H.Z., B.Z., F.D., K.X., M.L.), Johns Hopkins University, Baltimore, Maryland; and GlaxoSmithKline, King of Prussia, Pennsylvania (M.L.)
| | - Fang Du
- The Solomon H. Snyder Department of Neuroscience, High Throughput Biology Center (H.Z., B.Z., F.D., K.X., M.L.); Johns Hopkins Ion Channel Center (H.Z., B.Z., F.D., K.X., M.L.), Johns Hopkins University, Baltimore, Maryland; and GlaxoSmithKline, King of Prussia, Pennsylvania (M.L.)
| | - Kaiping Xu
- The Solomon H. Snyder Department of Neuroscience, High Throughput Biology Center (H.Z., B.Z., F.D., K.X., M.L.); Johns Hopkins Ion Channel Center (H.Z., B.Z., F.D., K.X., M.L.), Johns Hopkins University, Baltimore, Maryland; and GlaxoSmithKline, King of Prussia, Pennsylvania (M.L.)
| | - Min Li
- The Solomon H. Snyder Department of Neuroscience, High Throughput Biology Center (H.Z., B.Z., F.D., K.X., M.L.); Johns Hopkins Ion Channel Center (H.Z., B.Z., F.D., K.X., M.L.), Johns Hopkins University, Baltimore, Maryland; and GlaxoSmithKline, King of Prussia, Pennsylvania (M.L.).
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12
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Ranzato E, Magnelli V, Martinotti S, Waheed Z, Cain SM, Snutch TP, Marchetti C, Burlando B. Epigallocatechin-3-gallate elicits Ca2+ spike in MCF-7 breast cancer cells: essential role of Cav3.2 channels. Cell Calcium 2014; 56:285-95. [PMID: 25260713 DOI: 10.1016/j.ceca.2014.09.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 05/29/2014] [Accepted: 09/01/2014] [Indexed: 12/26/2022]
Abstract
We used MCF-7 human breast cancer cells that endogenously express Cav3.1 and Cav3.2 T-type Ca(2+) channels toward a mechanistic study on the effect of EGCG on [Ca(2+)]i. Confocal Ca(2+) imaging showed that EGCG induces a [Ca(2+)]i spike which is due to extracellular Ca(2+) entry and is sensitive to catalase and to low-specificity (mibefradil) and high-specificity (Z944) T-type Ca(2+)channel blockers. siRNA knockdown of T-type Ca(2+) channels indicated the involvement of Cav3.2 but not Cav3.1. Application of EGCG to HEK cells expressing either Cav3.2 or Cav3.1 induced enhancement of Cav3.2 and inhibition of Cav3.1 channel activity. Measurements of K(+) currents in MCF-7 cells showed a reversible, catalase-sensitive inhibitory effect of EGCG, while siRNA for the Kv1.1 K(+) channel induced a reduction of the EGCG [Ca(2+)]i spike. siRNA for Cav3.2 reduced EGCG cytotoxicity to MCF-7 cells, as measured by calcein viability assay. Together, data suggest that EGCG promotes the activation of Cav3.2 channels through K(+) current inhibition leading to membrane depolarization, and in addition increases Cav3.2 currents. Cav3.2 channels are in part responsible for EGCG inhibition of MCF-7 viability, suggesting that deregulation of [Ca(2+)]i by EGCG may be relevant in breast cancer treatment.
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Affiliation(s)
- Elia Ranzato
- Dipartimento di Scienze e Innovazione Tecnologica, DiSIT, Università del Piemonte Orientale, viale T. Michel 11, 15121 Alessandria, Italy
| | - Valeria Magnelli
- Dipartimento di Scienze e Innovazione Tecnologica, DiSIT, Università del Piemonte Orientale, viale T. Michel 11, 15121 Alessandria, Italy
| | - Simona Martinotti
- Dipartimento di Scienze e Innovazione Tecnologica, DiSIT, Università del Piemonte Orientale, viale T. Michel 11, 15121 Alessandria, Italy
| | - Zeina Waheed
- Michael Smith Laboratories, University of British Columbia, Rm 219 - 2185 East Mall, Vancouver, BC, Canada V6T 1Z4
| | - Stuart M Cain
- Michael Smith Laboratories, University of British Columbia, Rm 219 - 2185 East Mall, Vancouver, BC, Canada V6T 1Z4
| | - Terrance P Snutch
- Michael Smith Laboratories, University of British Columbia, Rm 219 - 2185 East Mall, Vancouver, BC, Canada V6T 1Z4
| | - Carla Marchetti
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, via De Marini 6, 16149 Genova, Italy
| | - Bruno Burlando
- Dipartimento di Scienze e Innovazione Tecnologica, DiSIT, Università del Piemonte Orientale, viale T. Michel 11, 15121 Alessandria, Italy; Istituto di Biofisica, Consiglio Nazionale delle Ricerche, via De Marini 6, 16149 Genova, Italy.
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13
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Abstract
Chronic pain is a major therapeutic problem as the current treatment options are unsatisfactory with low efficacy and deleterious side effects. Voltage-gated Ca2+ channels (VGCCs), which are multi-complex proteins consisting of α1, β, γ, and α2δ subunits, play an important role in pain signaling. These channels are involved in neurogenic inflammation, excitability, and neurotransmitter release in nociceptors. It has been previously shown that N-type VGCCs (Cav2.2) are a major pain target. U.S. FDA approval of three Cav2.2 antagonists, gabapentin, pregabalin, and ziconotide, for chronic pain underlies the importance of this channel subtype. Also, there has been increasing evidence that L-type (Cav1.2) or T-type (Cav3.2) VGCCs may be involved in pain signaling and chronic pain. In order to develop novel pain therapeutics and to understand the role of VGCC subtypes, discovering subtype selective VGCC inhibitors or methods that selectively target the inhibitor into nociceptors would be essential. This review describes the various VGCC subtype inhibitors and the potential of utilizing VGCC subtypes as targets of chronic pain. Development of VGCC subtype inhibitors and targeting them into nociceptors will contribute to a better understanding of the roles of VGCC subtypes in pain at a spinal level as well as development of a novel class of analgesics for chronic pain.
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Affiliation(s)
- Seungkyu Lee
- F. M. Kirby Neurobiology Center, Children's Hospital Boston, Boston MA 02115 USA; ; Department of Neurobiology, Harvard Medical School, Boston MA 02115 USA
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14
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Choi KH. The design and discovery of T-type calcium channel inhibitors for the treatment of central nervous system disorders. Expert Opin Drug Discov 2013; 8:919-31. [DOI: 10.1517/17460441.2013.796926] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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15
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Borzenko A, Pajouhesh H, Morrison JL, Tringham E, Snutch TP, Schafer LL. Modular, efficient synthesis of asymmetrically substituted piperazine scaffolds as potent calcium channel blockers. Bioorg Med Chem Lett 2013; 23:3257-61. [PMID: 23639535 DOI: 10.1016/j.bmcl.2013.03.114] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 03/23/2013] [Accepted: 03/27/2013] [Indexed: 11/28/2022]
Abstract
A novel approach to the synthesis of substituted piperazines and their investigation as N-type calcium channel blockers is presented. A common scaffold exhibiting high activity as N-type blockers is N-substituted piperazine. Using recently developed titanium and zirconium catalysts, we describe the efficient and modular synthesis of 2,5-asymmetrically disubstituted piperazines from simple amines and alkynes. The method requires only three isolation/purification protocols and no protection/deprotection steps for the diastereoselective synthesis of 2,5-dialkylated piperazines in moderate to high yield. Screening of the synthesized piperazines for N-type channel blocking activity and selectivity shows the highest activity for a compound with a benzhydryl group on the nitrogen (position 1) and an unprotected alcohol-functionalized side chain.
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Affiliation(s)
- Andrey Borzenko
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
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Wu ZZ, Wang ZW, Zhang LG, An ZX, Zhong DH, Huang QP, Luo MR, Liao YJ, Jin L, Li CZ, Kisaalita WS. Responsiveness of voltage-gated calcium channels in SH-SY5Y human neuroblastoma cells on quasi-three-dimensional micropatterns formed with poly (l-lactic acid). Int J Nanomedicine 2013; 8:93-107. [PMID: 23319861 PMCID: PMC3540970 DOI: 10.2147/ijn.s38362] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Introduction In this study, quasi-three-dimensional (3D) microwell patterns were fabricated with poly (l-lactic acid) for the development of cell-based assays, targeting voltage-gated calcium channels (VGCCs). Methods and materials SH-SY5Y human neuroblastoma cells were interfaced with the microwell patterns and found to grow as two dimensional (2D), 3D, and near two dimensional (N2D), categorized on the basis of the cells’ location in the pattern. The capability of the microwell patterns to support 3D cell growth was evaluated in terms of the percentage of the cells in each growth category. Cell spreading was analyzed in terms of projection areas under light microscopy. SH-SY5Y cells’ VGCC responsiveness was evaluated with confocal microscopy and a calcium fluorescent indicator, Calcium Green™-1. The expression of L-type calcium channels was evaluated using immunofluorescence staining with DM-BODIPY. Results It was found that cells within the microwells, either N2D or 3D, showed more rounded shapes and less projection areas than 2D cells on flat poly (l-lactic acid) substrates. Also, cells in microwells showed a significantly lower VGCC responsiveness than cells on flat substrates, in terms of both response magnitudes and percentages of responsive cells, upon depolarization with 50 mM K+. This lower VGCC responsiveness could not be explained by the difference in L-type calcium channel expression. For the two patterns addressed in this study, N2D cells consistently exhibited an intermediate value of either projection areas or VGCC responsiveness between those for 2D and 3D cells, suggesting a correlative relation between cell morphology and VGCC responsiveness. Conclusion These results suggest that the pattern structure and therefore the cell growth characteristics were critical factors in determining cell VGCC responsiveness and thus provide an approach for engineering cell functionality in cell-based assay systems and tissue engineering scaffolds.
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Affiliation(s)
- Ze-Zhi Wu
- Key Laboratory of Biorheological Science and Technology of the State Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, People's Republic of China.
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Vetter I. Development and optimization of FLIPR high throughput calcium assays for ion channels and GPCRs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:45-82. [PMID: 22453938 DOI: 10.1007/978-94-007-2888-2_3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Ca(2+) permeable ion channels and GPCRs linked to Ca(2+) release are important drug targets, with modulation of Ca(2+) signaling increasingly recognized as a valid therapeutic strategy in a range of diseases. The FLIPR is a high throughput imaging plate reader that has contributed substantially to drug discovery efforts and pharmacological characterization of receptors and ion channels coupled to Ca(2+). Now in its fourth generation, the FLIPR(TETRA) is an industry standard for high throughput Ca(2+) assays. With an increasing number of excitation LED banks and emission filter sets available; FLIPR Ca(2+) assays are becoming more versatile. This chapter describes general methods for establishing robust FLIPR Ca(2+) assays, incorporating practical aspects as well as suggestions for assay optimization, to guide the reader in the development and optimization of high throughput FLIPR assays for ion channels and GPCRs.
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Affiliation(s)
- Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia.
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Pexton T, Moeller-Bertram T, Schilling JM, Wallace MS. Targeting voltage-gated calcium channels for the treatment of neuropathic pain: a review of drug development. Expert Opin Investig Drugs 2011; 20:1277-84. [DOI: 10.1517/13543784.2011.600686] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Vortherms TA, Swensen AM, Niforatos W, Limberis JT, Neelands TR, Janis RS, Thimmapaya R, Donnelly-Roberts DL, Namovic MT, Zhang D, Brent Putman C, Martin RL, Surowy CS, Jarvis MF, Scott VE. Comparative analysis of inactivated-state block of N-type (Cav2.2) calcium channels. Inflamm Res 2011; 60:683-93. [DOI: 10.1007/s00011-011-0322-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 02/18/2011] [Accepted: 02/21/2011] [Indexed: 12/01/2022] Open
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Pubill D, Gandía L. Response to Letter to the Editor from Westerink and Hondebrink. Toxicol Appl Pharmacol 2010. [DOI: 10.1016/j.taap.2010.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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