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Wang D, Herzig V, Dekan Z, Rosengren KJ, Payne CD, Hasan MM, Zhuang J, Bourinet E, Ragnarsson L, Alewood PF, Lewis RJ. Novel Scorpion Toxin ω-Buthitoxin-Hf1a Selectively Inhibits Calcium Influx via Ca V3.3 and Ca V3.2 and Alleviates Allodynia in a Mouse Model of Acute Postsurgical Pain. Int J Mol Sci 2024; 25:4745. [PMID: 38731963 PMCID: PMC11084959 DOI: 10.3390/ijms25094745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
Venom peptides have evolved to target a wide range of membrane proteins through diverse mechanisms of action and structures, providing promising therapeutic leads for diseases, including pain, epilepsy, and cancer, as well as unique probes of ion channel structure-function. In this work, a high-throughput FLIPR window current screening assay on T-type CaV3.2 guided the isolation of a novel peptide named ω-Buthitoxin-Hf1a from scorpion Hottentotta franzwerneri crude venom. At only 10 amino acid residues with one disulfide bond, it is not only the smallest venom peptide known to target T-type CaVs but also the smallest structured scorpion venom peptide yet discovered. Synthetic Hf1a peptides were prepared with C-terminal amidation (Hf1a-NH2) or a free C-terminus (Hf1a-OH). Electrophysiological characterization revealed Hf1a-NH2 to be a concentration-dependent partial inhibitor of CaV3.2 (IC50 = 1.18 μM) and CaV3.3 (IC50 = 0.49 μM) depolarized currents but was ineffective at CaV3.1. Hf1a-OH did not show activity against any of the three T-type subtypes. Additionally, neither form showed activity against N-type CaV2.2 or L-type calcium channels. The three-dimensional structure of Hf1a-NH2 was determined using NMR spectroscopy and used in docking studies to predict its binding site at CaV3.2 and CaV3.3. As both CaV3.2 and CaV3.3 have been implicated in peripheral pain signaling, the analgesic potential of Hf1a-NH2 was explored in vivo in a mouse model of incision-induced acute post-surgical pain. Consistent with this role, Hf1a-NH2 produced antiallodynia in both mechanical and thermal pain.
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Affiliation(s)
- Dan Wang
- Department of Chinese Medicine and Pharmacy, School of Pharmacy, Jiangsu University, Zhenjiang 212013, China;
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia (L.R.); (P.F.A.)
| | - Volker Herzig
- Centre for Bioinnovation, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia;
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia
| | - Zoltan Dekan
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia (L.R.); (P.F.A.)
| | - K. Johan Rosengren
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; (K.J.R.); (C.D.P.)
| | - Colton D. Payne
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; (K.J.R.); (C.D.P.)
| | - Md. Mahadhi Hasan
- Pharmacy Discipline, Life Science School, Khulna University, Khulna 9208, Bangladesh;
| | - Jiajie Zhuang
- Department of Chinese Medicine and Pharmacy, School of Pharmacy, Jiangsu University, Zhenjiang 212013, China;
| | - Emmanuel Bourinet
- Institute of Functional Genomics, Montpellier University, CNRS, INSERM, 34090 Montpellier, France;
| | - Lotten Ragnarsson
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia (L.R.); (P.F.A.)
| | - Paul F. Alewood
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia (L.R.); (P.F.A.)
| | - Richard J. Lewis
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia (L.R.); (P.F.A.)
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Lanne A, E J Usselmann L, Llowarch P, Michaelides IN, Fillmore M, Holdgate GA. A perspective on the changing landscape of HTS. Drug Discov Today 2023:103670. [PMID: 37328053 DOI: 10.1016/j.drudis.2023.103670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/14/2023] [Accepted: 06/09/2023] [Indexed: 06/18/2023]
Abstract
Recently, there has been a change in the types of drug target entering early drug discovery portfolios. A significant increase in the number of challenging targets or which would have historically been classed as intractable has been observed. Such targets often have shallow or non-existent ligand-binding sites, can have disordered structures or domains or can be involved in protein-protein or protein-DNA interactions. The nature of the screens required to identify useful hits has, by necessity, also changed. The range of drug modalities explored has also increased and the chemistry required to design and optimise these molecules has adapted. In this review, we discuss this changing landscape and provide insights into the future requirements for small-molecule hit and lead generation.
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Affiliation(s)
- Alice Lanne
- High Throughput Screening, Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Alderley Park, UK
| | - Laura E J Usselmann
- High Throughput Screening, Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Alderley Park, UK
| | - Poppy Llowarch
- High Throughput Screening, Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Alderley Park, UK
| | - Iacovos N Michaelides
- Fragment Based Lead Generation, Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
| | - Martin Fillmore
- DNA Encoded Library, Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
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Udoh M, Bladen C, Heblinski M, Luo JL, Janve VS, Anderson LL, McGregor IS, Arnold JC. The anticonvulsant phytocannabinoids CBGVA and CBDVA inhibit recombinant T-type channels. Front Pharmacol 2022; 13:1048259. [PMID: 36386164 PMCID: PMC9664070 DOI: 10.3389/fphar.2022.1048259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 10/17/2022] [Indexed: 02/21/2023] Open
Abstract
Introduction: Cannabidiol (CBD) has been clinically approved for intractable epilepsies, offering hope that novel anticonvulsants in the phytocannabinoid class might be developed. Looking beyond CBD, we have recently reported that a series of biosynthetic precursor molecules found in cannabis display anticonvulsant properties. However, information on the pharmacological activities of these compounds on CNS drug targets is limited. The current study aimed to fill this knowledge gap by investigating whether anticonvulsant phytocannabinoids affect T-type calcium channels, which are known to modulate neuronal excitability, and may be relevant to the anti-seizure effects of this class of compounds. Materials and methods: A fluorescence-based assay was used to screen the ability of the phytocannabinoids to inhibit human T-type calcium channels overexpressed in HEK-293 cells. A subset of compounds was further examined using patch-clamp electrophysiology. Alphascreen technology was used to characterise selected compounds against G-protein coupled-receptor 55 (GPR55) overexpressed in HEK-293 cells, as GPR55 is another target of the phytocannabinoids. Results: A single 10 µM concentration screen in the fluorescence-based assay showed that phytocannabinoids inhibited T-type channels with substantial effects on Cav3.1 and Cav3.2 channels compared to the Cav3.3 channel. The anticonvulsant phytocannabinoids cannabigerovarinic acid (CBGVA) and cannabidivarinic acid (CBDVA) had the greatest magnitudes of effect (≥80% inhibition against Cav3.1 and Cav3.2), so were fully characterized in concentration-response studies. CBGVA and CBDVA had IC50 values of 6 μM and 2 µM on Cav3.1 channels; 2 μM and 11 µM on Cav3.2 channels, respectively. Biophysical studies at Cav3.1 showed that CBGVA caused a hyperpolarisation shift of steady-state inhibition. Both CBGVA and CBDVA had a use-dependent effect and preferentially inhibited Cav3.1 current in a slow inactivated state. CBGVA and CBDVA were also shown to antagonise GPR55. Conclusion and implications: These findings show that CBGVA and CBDVA inhibit T-type calcium channels and GPR55. These compounds should be further investigated to develop novel therapeutics for treating diseases associated with dysfunctional T-type channel activity.
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Affiliation(s)
- Michael Udoh
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia,Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia,Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | - Chris Bladen
- Macquarie Medical School, Macquarie University, Sydney, NSW, Australia,*Correspondence: Chris Bladen, ; Jonathon C. Arnold,
| | - Marika Heblinski
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia,Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia,Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | - Jia Lin Luo
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia,Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia,School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Vaishali S. Janve
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia,Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia,Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | - Lyndsey L. Anderson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia,Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia,Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| | - Iain S. McGregor
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia,Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia,School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Jonathon C. Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW, Australia,Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia,Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia,*Correspondence: Chris Bladen, ; Jonathon C. Arnold,
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Kamau PM, Li H, Yao Z, Han Y, Luo A, Zhang H, Boonyarat C, Yenjai C, Mwangi J, Zeng L, Yang S, Lai R, Luo L. Potent Ca V3.2 channel inhibitors exert analgesic effects in acute and chronic pain models. Biomed Pharmacother 2022; 153:113310. [PMID: 35728351 DOI: 10.1016/j.biopha.2022.113310] [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: 05/15/2022] [Revised: 06/08/2022] [Accepted: 06/14/2022] [Indexed: 11/02/2022] Open
Abstract
Pain is the most common presenting physical symptom and a primary reason for seeking medical care, which chronically affects people's mental health and social life. CaV3.2 channel plays an essential role in the peripheral processing maintenance of pain states. This study was designed to identify novel drug candidates targeting the CaV3.2 channel. Whole-cell patch-clamp, cellular thermal shift assay, FlexStation, in vivo and in vitro CaV3.2 knock-down, site-directed mutagenesis, and double-mutant cycle analysis were employed to explore the pain-related receptors and ligand-receptor direct interaction. We found that toddaculin efficiently inhibits the CaV3.2 channel and significantly reduced the excitability of dorsal root ganglion neurons and pain behaviors. The Carbonyl group of coumarins directly interacts with the pore domain of CaV3.2 via van der Waals (VDW) force. Docking with binding pockets further led us to identify glycycoumarin, which exhibited more potent inhibition on the CaV3.2 channel and better analgesic activity than the parent compound. Toddaculin and its analog showed beneficial therapeutic effects in pain models. Toddaculin binding pocket on CaV3.2 might be a promising docking site for the design of drugs.
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Affiliation(s)
- Peter Muiruri Kamau
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center, and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, Yunnan, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center, and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, Yunnan, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhihao Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center, and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, Yunnan, China; College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Yalan Han
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center, and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, Yunnan, China
| | - Anna Luo
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center, and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, Yunnan, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center, and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, Yunnan, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chantana Boonyarat
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Chavi Yenjai
- Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - James Mwangi
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center, and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, Yunnan, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lin Zeng
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center, and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, Yunnan, China
| | - Shilong Yang
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Ren Lai
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center, and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, Yunnan, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Lei Luo
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, National Resource Center for Non-Human Primates, Kunming Primate Research Center, National Research Facility for Phenotypic & Genetic Analysis of Model Animals (Primate Facility), Sino-African Joint Research Center, and Engineering Laboratory of Peptides, Kunming Institute of Zoology, Kunming 650107, Yunnan, China.
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5
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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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Bell DC, Dallas ML. Advancing Ion Channel Research with Automated Patch Clamp (APC) Electrophysiology Platforms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:21-32. [DOI: 10.1007/978-981-16-4254-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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8
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Wang D, Neupane P, Ragnarsson L, Capon RJ, Lewis RJ. Synthesis of Pseudellone Analogs and Characterization as Novel T-type Calcium Channel Blockers. Mar Drugs 2018; 16:md16120475. [PMID: 30487473 PMCID: PMC6315694 DOI: 10.3390/md16120475] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 11/21/2018] [Accepted: 11/26/2018] [Indexed: 11/16/2022] Open
Abstract
T-type calcium channel (CaV3.x) blockers are receiving increasing attention as potential therapeutics for the treatment of pathophysiological disorders and diseases, including absence epilepsy, Parkinson's disease (PD), hypertension, cardiovascular diseases, cancers, and pain. However, few clinically approved CaV3.x blockers are available, and selective pharmacological tools are needed to further unravel the roles of individual CaV3.x subtypes. In this work, through an efficient synthetic route to the marine fungal product pseudellone C, we obtained bisindole alkaloid analogs of pseudellone C with a modified tryptophan moiety and identified two CaV3.2 (2, IC50 = 18.24 µM; 3, IC50 = 6.59 µM) and CaV3.3 (2, IC50 = 7.71 µM; 3, IC50 = 3.81 µM) selective blockers using a FLIPR cell-based assay measuring CaV3.x window currents. Further characterization by whole-cell patch-clamp revealed a preferential block of CaV3.1 activated current (2, IC50 = 5.60 µM; 3, IC50 = 9.91 µM), suggesting their state-dependent block is subtype specific.
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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.
| | - Pratik Neupane
- 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.
| | - Robert J Capon
- 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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Abstract
INTRODUCTION T-type calcium channels are attractive targets for potential treatment of epilepsy inflammatory or neuropathic pain, insomnia, Parkinson's disease, and cancer. Three isoforms having different biophysical functions are expressed in peripheral and central nerve. Since the withdrawal of mibefradil, the first compound marketed for selective T-type calcium channel blockade, extensive efforts have been made to identify more selective T-type calcium channel blockers. AREAS COVERED This review covers the 43 patents describing 'organic small molecules as T-type calcium channel blockers'-published since 2012. The most recent similar patent review was published in 2011. Information from a recent review article and relevant research papers has been included, as well as biological data and clinical trial results where available. EXPERT OPINION Triazinone derivatives, carbazole compounds, and aryl triazole/imidazole amide derivatives display potent blockade activity α1H, α1G, and pan T-type calcium channel subtypes, respectively, though the specificity of the letter is still unsatisfactory. Nonetheless, improvements seen in the efficacy of compounds targeting α1H T-type calcium channels indicate significant progress. Ongoing clinical trials are for the candidates Z944 (Phase II) and ACT-709478 (Phase II) appear promising. These studies may lead to a new generation of inhibitors with higher selectivity, improved physicochemical properties, and reduced side effects.
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Affiliation(s)
- Ghilsoo Nam
- a Center for Neuro-Medicine , Brain Science Institute, Korea Institutes of Science and Technology (KIST) , Seoul , Republic of Korea.,b Division of Bio-Medical Science, KIST School , Korea University of Science and Technology Seoul , Seoul , Republic of Korea
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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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11
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Annecchino LA, Schultz SR. Progress in automating patch clamp cellular physiology. Brain Neurosci Adv 2018; 2:2398212818776561. [PMID: 32166142 PMCID: PMC7058203 DOI: 10.1177/2398212818776561] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/19/2018] [Indexed: 12/30/2022] Open
Abstract
Patch clamp electrophysiology has transformed research in the life sciences over the last few decades. Since their inception, automatic patch clamp platforms have evolved considerably, demonstrating the capability to address both voltage- and ligand-gated channels, and showing the potential to play a pivotal role in drug discovery and biomedical research. Unfortunately, the cell suspension assays to which early systems were limited cannot recreate biologically relevant cellular environments, or capture higher order aspects of synaptic physiology and network dynamics. In vivo patch clamp electrophysiology has the potential to yield more biologically complex information and be especially useful in reverse engineering the molecular and cellular mechanisms of single-cell and network neuronal computation, while capturing important aspects of human disease mechanisms and possible therapeutic strategies. Unfortunately, it is a difficult procedure with a steep learning curve, which has restricted dissemination of the technique. Luckily, in vivo patch clamp electrophysiology seems particularly amenable to robotic automation. In this review, we document the development of automated patch clamp technology, from early systems based on multi-well plates through to automated planar-array platforms, and modern robotic platforms capable of performing two-photon targeted whole-cell electrophysiological recordings in vivo.
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Affiliation(s)
- Luca A. Annecchino
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, UK
| | - Simon R. Schultz
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, UK
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12
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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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13
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Bell DC, Dallas ML. Using automated patch clamp electrophysiology platforms in pain-related ion channel research: insights from industry and academia. Br J Pharmacol 2017. [PMID: 28622411 DOI: 10.1111/bph.13916] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Automated patch clamp (APC) technology was first developed at the turn of the millennium. The increased throughput it afforded promised a new paradigm in ion channel recordings, offering the potential to overcome the time-consuming, low-throughput bottleneck, arising from manual patch clamp investigations. This has relevance to the fast-paced development of novel therapies for chronic pain. This review highlights the advances in technology, using select examples that have facilitated APC usage in both industry and academia. It covers both first generation and the latest developments in second-generation platforms. In addition, it also provides an overview of the pain research field and how APC platforms have furthered our understanding of ion channel research and the development of pharmacological tools and therapeutics. APC platforms have much to offer to the ion channel research community, and this review highlights areas of best practice for both academia and industry. The impact of APC platforms and the prospects of ion channel research and improved therapeutics for chronic pain will be evaluated. LINKED ARTICLES This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc.
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Affiliation(s)
| | - Mark L Dallas
- School of Pharmacy, University of Reading, Reading, UK
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14
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Siegrist R, Pozzi D, Jacob G, Torrisi C, Colas K, Braibant B, Mawet J, Pfeifer T, de Kanter R, Roch C, Kessler M, Corminboeuf O, Bezençon O. Structure–Activity Relationship, Drug Metabolism and Pharmacokinetics Properties Optimization, and in Vivo Studies of New Brain Penetrant Triple T-Type Calcium Channel Blockers. J Med Chem 2016; 59:10661-10675. [DOI: 10.1021/acs.jmedchem.6b01356] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Romain Siegrist
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Davide Pozzi
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Gaël Jacob
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Caterina Torrisi
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Kilian Colas
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Bertrand Braibant
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Jacques Mawet
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Thomas Pfeifer
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Ruben de Kanter
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Catherine Roch
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Melanie Kessler
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Olivier Corminboeuf
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
| | - Olivier Bezençon
- Drug Discovery Chemistry,
Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse
16, CH-4123 Allschwil, Switzerland
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15
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Remen L, Bezençon O, Simons L, Gaston R, Downing D, Gatfield J, Roch C, Kessler M, Mosbacher J, Pfeifer T, Grisostomi C, Rey M, Ertel EA, Moon R. Preparation, Antiepileptic Activity, and Cardiovascular Safety of Dihydropyrazoles as Brain-Penetrant T-Type Calcium Channel Blockers. J Med Chem 2016; 59:8398-411. [DOI: 10.1021/acs.jmedchem.6b00756] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Lubos Remen
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Olivier Bezençon
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Lloyd Simons
- Kalexsyn, Inc., 4502 Campus Drive, Kalamazoo, Michigan 49008, United States
| | - Rick Gaston
- Kalexsyn, Inc., 4502 Campus Drive, Kalamazoo, Michigan 49008, United States
| | - Dennis Downing
- Kalexsyn, Inc., 4502 Campus Drive, Kalamazoo, Michigan 49008, United States
| | - John Gatfield
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Catherine Roch
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Melanie Kessler
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Johannes Mosbacher
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Thomas Pfeifer
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Corinna Grisostomi
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Markus Rey
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Eric A. Ertel
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
| | - Richard Moon
- Drug
Discovery Chemistry, Biology and Pharmacology, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
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16
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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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17
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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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18
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Du Y, Days E, Romaine I, Abney KK, Kaufmann K, Sulikowski G, Stauffer S, Lindsley CW, Weaver CD. Development and validation of a thallium flux-based functional assay for the sodium channel NaV1.7 and its utility for lead discovery and compound profiling. ACS Chem Neurosci 2015; 6:871-8. [PMID: 25879403 DOI: 10.1021/acschemneuro.5b00004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Ion channels are critical for life, and they are targets of numerous drugs. The sequencing of the human genome has revealed the existence of hundreds of different ion channel subunits capable of forming thousands of ion channels. In the face of this diversity, we only have a few selective small-molecule tools to aid in our understanding of the role specific ion channels in physiology which may in turn help illuminate their therapeutic potential. Although the advent of automated electrophysiology has increased the rate at which we can screen for and characterize ion channel modulators, the technique's high per-measurement cost and moderate throughput compared to other high-throughput screening approaches limit its utility for large-scale high-throughput screening. Therefore, lower cost, more rapid techniques are needed. While ion channel types capable of fluxing calcium are well-served by low cost, very high-throughput fluorescence-based assays, other channel types such as sodium channels remain underserved by present functional assay techniques. In order to address this shortcoming, we have developed a thallium flux-based assay for sodium channels using the NaV1.7 channel as a model target. We show that the assay is able to rapidly and cost-effectively identify NaV1.7 inhibitors thus providing a new method useful for the discovery and profiling of sodium channel modulators.
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Affiliation(s)
| | | | | | - Kris K. Abney
- Meharry Medical
College Program in Pharmacology, Nashville, Tennessee 37208, United States
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19
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Jarvis MF, Scott VE, McGaraughty S, Chu KL, Xu J, Niforatos W, Milicic I, Joshi S, Zhang Q, Xia Z. A peripherally acting, selective T-type calcium channel blocker, ABT-639, effectively reduces nociceptive and neuropathic pain in rats. Biochem Pharmacol 2014; 89:536-44. [DOI: 10.1016/j.bcp.2014.03.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 03/25/2014] [Accepted: 03/26/2014] [Indexed: 01/03/2023]
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20
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Zipprer EM, Neggers M, Kushwaha A, Rayavara K, Desai SA. A kinetic fluorescence assay reveals unusual features of Ca⁺⁺ uptake in Plasmodium falciparum-infected erythrocytes. Malar J 2014; 13:184. [PMID: 24885754 PMCID: PMC4078004 DOI: 10.1186/1475-2875-13-184] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 05/11/2014] [Indexed: 11/13/2022] Open
Abstract
Background To facilitate development within erythrocytes, malaria parasites increase their host cell uptake of diverse solutes including Ca++. The mechanism and molecular basis of increased Ca++ permeability remains less well studied than that of other solutes. Methods Based on an appropriate Ca++ affinity and its greater brightness than related fluorophores, Fluo-8 was selected and used to develop a robust fluorescence-based assay for Ca++ uptake by human erythrocytes infected with Plasmodium falciparum. Results Both uninfected and infected cells exhibited a large Ca++-dependent fluorescence signal after loading with the Fluo-8 dye. Probenecid, an inhibitor of erythrocyte organic anion transporters, abolished the fluorescence signal in uninfected cells; in infected cells, this agent increased fluorescence via mechanisms that depend on parasite genotype. Kinetic fluorescence measurements in 384-well microplates revealed that the infected cell Ca++ uptake is not mediated by the plasmodial surface anion channel (PSAC), a parasite nutrient channel at the host membrane; it also appears to be distinct from mammalian Ca++ channels. Imaging studies confirmed a low intracellular Ca++ in uninfected cells and higher levels in both the host and parasite compartments of infected cells. Parasite growth inhibition studies revealed a conserved requirement for extracellular Ca++. Conclusions Nondestructive loading of Fluo-8 into human erythrocytes permits measurement of Ca++ uptake kinetics. The greater Ca++ permeability of cells infected with malaria parasites is apparent when probenecid is used to inhibit Fluo-8 efflux at the host membrane. This permeability is mediated by a distinct pathway and may be essential for intracellular parasite development. The miniaturized assay presented here should help clarify the precise transport mechanism and may identify inhibitors suitable for antimalarial drug development.
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Affiliation(s)
| | | | | | | | - Sanjay A Desai
- The Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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21
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Cav3.2 T-type calcium channel is required for the NFAT-dependent Sox9 expression in tracheal cartilage. Proc Natl Acad Sci U S A 2014; 111:E1990-8. [PMID: 24778262 DOI: 10.1073/pnas.1323112111] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Intracellular Ca(2+) transient is crucial in initiating the differentiation of mesenchymal cells into chondrocytes, but whether voltage-gated Ca(2+) channels are involved remains uncertain. Here, we show that the T-type voltage-gated Ca(2+) channel Cav3.2 is essential for tracheal chondrogenesis. Mice lacking this channel (Cav3.2(-/-)) show congenital tracheal stenosis because of incomplete formation of cartilaginous tracheal support. Conversely, Cav3.2 overexpression in ATDC5 cells enhances chondrogenesis, which could be blunted by both blocking T-type Ca(2+) channels and inhibiting calcineurin and suggests that Cav3.2 is responsible for Ca(2+) influx during chondrogenesis. Finally, the expression of sex determination region of Y chromosome (SRY)-related high-mobility group-Box gene 9 (Sox9), one of the earliest markers of committed chondrogenic cells, is reduced in Cav3.2(-/-) tracheas. Mechanistically, Ca(2+) influx via Cav3.2 activates the calcineurin/nuclear factor of the activated T-cell (NFAT) signaling pathway, and a previously unidentified NFAT binding site is identified within the mouse Sox9 promoter using a luciferase reporter assay and gel shift and ChIP studies. Our findings define a previously unidentified mechanism that Ca(2+) influx via the Cav3.2 T-type Ca(2+) channel regulates Sox9 expression through the calcineurin/NFAT signaling pathway during tracheal chondrogenesis.
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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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23
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Cazade M, Nuss CE, Bidaud I, Renger JJ, Uebele VN, Lory P, Chemin J. Cross-modulation and molecular interaction at the Cav3.3 protein between the endogenous lipids and the T-type calcium channel antagonist TTA-A2. Mol Pharmacol 2013; 85:218-25. [PMID: 24214826 DOI: 10.1124/mol.113.089581] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
T-type calcium channels (T/Ca(v)3-channels) are implicated in various physiologic and pathophysiologic processes such as epilepsy, sleep disorders, hypertension, and cancer. T-channels are the target of endogenous signaling lipids including the endocannabinoid anandamide, the ω3-fatty acids, and the lipoamino-acids. However, the precise molecular mechanism by which these molecules inhibit T-current is unknown. In this study, we provided a detailed electrophysiologic and pharmacologic analysis indicating that the effects of the major N-acyl derivatives on the Ca(v)3.3 current share many similarities with those of TTA-A2 [(R)-2-(4-cyclopropylphenyl)-N-(1-(5-(2,2,2-trifluoroethoxy)pyridin-2-yl)ethyl)acetamide], a synthetic T-channel inhibitor. Using radioactive binding assays with the TTA-A2 derivative [(3)H]TTA-A1 [(R)-2-(4-(tert-butyl)phenyl)-N-(1-(5-methoxypyridin-2-yl)ethyl)acetamide], we demonstrated that polyunsaturated lipids, which inhibit the Ca(v)3.3 current, as NAGly (N-arachidonoyl glycine), NASer (N-arachidonoyl-l-serine), anandamide, NADA (N-arachidonoyl dopamine), NATau (N-arachidonoyl taurine), and NA-5HT (N-arachidonoyl serotonin), all displaced [(3)H]TTA-A1 binding to membranes prepared from cells expressing Ca(v)3.3, with Ki in a micromolar or submicromolar range. In contrast, lipids with a saturated alkyl chain, as N-arachidoyl glycine and N-arachidoyl ethanolamine, which did not inhibit the Ca(v)3.3 current, had no effect on [(3)H]TTA-A1 binding. Accordingly, bio-active lipids occluded TTA-A2 effect on Ca(v)3.3 current. In addition, TTA-Q4 [(S)-4-(6-chloro-4-cyclopropyl-3-(2,2-difluoroethyl)-2-oxo-1,2,3,4-tetrahydroquinazolin-4-yl)benzonitrile], a positive allosteric modulator of [(3)H]TTA-A1 binding and TTA-A2 functional inhibition, acted in a synergistic manner to increase lipid-induced inhibition of the Ca(v)3.3 current. Overall, our results demonstrate a common molecular mechanism for the synthetic T-channel inhibitors and the endogenous lipids, and indicate that TTA-A2 and TTA-Q4 could be important pharmacologic tools to dissect the involvement of T-current in the physiologic effects of endogenous lipids.
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Affiliation(s)
- Magali Cazade
- Institut de Génomique Fonctionnelle, Universités Montpellier 1 and 2, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5203, Institut National de la Santé et de la Recherche Médicale U661, LabEx Ion Channel Science and Therapeutics, Montpellier, France (M.C., I.B., P.L., J.C.); and Department of Neuroscience, Merck Research Laboratories, West Point, Pennsylvania (C.E.N., J.J.R., V.N.U.)
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24
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Gackière F, Warnier M, Katsogiannou M, Derouiche S, Delcourt P, Dewailly E, Slomianny C, Humez S, Prevarskaya N, Roudbaraki M, Mariot P. Functional coupling between large-conductance potassium channels and Cav3.2 voltage-dependent calcium channels participates in prostate cancer cell growth. Biol Open 2013; 2:941-51. [PMID: 24143281 PMCID: PMC3773341 DOI: 10.1242/bio.20135215] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 06/26/2013] [Indexed: 12/11/2022] Open
Abstract
It is strongly suspected that potassium (K+) channels are involved in various aspects of prostate cancer development, such as cell growth. However, the molecular nature of those K+ channels implicated in prostate cancer cell proliferation and the mechanisms through which they control proliferation are still unknown. This study uses pharmacological, biophysical and molecular approaches to show that the main voltage-dependent K+ current in prostate cancer LNCaP cells is carried by large-conductance BK channels. Indeed, most of the voltage-dependent current was inhibited by inhibitors of BK channels (paxillin and iberiotoxin) and by siRNA targeting BK channels. In addition, we reveal that BK channels constitute the main K+ channel family involved in setting the resting membrane potential in LNCaP cells at around −40 mV. This consequently promotes a constitutive calcium entry through T-type Cav3.2 calcium channels. We demonstrate, using single-channel recording, confocal imaging and co-immunoprecipitation approaches, that both channels form macromolecular complexes. Finally, using flow cytometry cell cycle measurements, cell survival assays and Ki67 immunofluorescent staining, we show that both BK and Cav3.2 channels participate in the proliferation of prostate cancer cells.
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Affiliation(s)
- Florian Gackière
- Laboratoire de Physiologie Cellulaire, INSERM U1003, Bâtiment SN3, Université Lille 1 , 59655 Villeneuve d'Ascq Cédex , France
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25
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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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26
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Expression and pharmacology of endogenous Cav channels in SH-SY5Y human neuroblastoma cells. PLoS One 2013; 8:e59293. [PMID: 23536870 PMCID: PMC3607609 DOI: 10.1371/journal.pone.0059293] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Accepted: 02/13/2013] [Indexed: 12/24/2022] Open
Abstract
SH-SY5Y human neuroblastoma cells provide a useful in vitro model to study the mechanisms underlying neurotransmission and nociception. These cells are derived from human sympathetic neuronal tissue and thus, express a number of the Cav channel subtypes essential for regulation of important physiological functions, such as heart contraction and nociception, including the clinically validated pain target Cav2.2. We have detected mRNA transcripts for a range of endogenous expressed subtypes Cav1.3, Cav2.2 (including two Cav1.3, and three Cav2.2 splice variant isoforms) and Cav3.1 in SH-SY5Y cells; as well as Cav auxiliary subunits α2δ1–3, β1, β3, β4, γ1, γ4–5, and γ7. Both high- and low-voltage activated Cav channels generated calcium signals in SH-SY5Y cells. Pharmacological characterisation using ω-conotoxins CVID and MVIIA revealed significantly (∼ 10-fold) higher affinity at human versus rat Cav2.2, while GVIA, which interacts with Cav2.2 through a distinct pharmacophore had similar affinity for both species. CVID, GVIA and MVIIA affinity was higher for SH-SY5Y membranes vs whole cells in the binding assays and functional assays, suggesting auxiliary subunits expressed endogenously in native systems can strongly influence Cav2.2 channels pharmacology. These results may have implications for strategies used to identify therapeutic leads at Cav2.2 channels.
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27
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Xiang Z, Thompson AD, Brogan JT, Schulte ML, Melancon BJ, Mi D, Lewis LM, Zou B, Yang L, Morrison R, Santomango T, Byers F, Brewer K, Aldrich JS, Yu H, Dawson ES, Li M, McManus O, Jones CK, Daniels JS, Hopkins CR, Xie XS, Conn PJ, Weaver CD, Lindsley CW. The Discovery and Characterization of ML218: A Novel, Centrally Active T-Type Calcium Channel Inhibitor with Robust Effects in STN Neurons and in a Rodent Model of Parkinson's Disease. ACS Chem Neurosci 2011; 2:730-742. [PMID: 22368764 DOI: 10.1021/cn200090z] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
T-type Ca(2+) channel inhibitors hold tremendous therapeutic potential for the treatment of pain, epilepsy, sleep disorders, essential tremor and other neurological disorders; however, a lack of truly selective tools has hindered basic research, and selective tools from the pharmaceutical industry are potentially burdened with intellectual property (IP) constraints. Thus, an MLPCN high-throughput screen (HTS) was conducted to identify novel T-type Ca(2+) channel inhibitors free from IP constraints, and freely available through the MLPCN, for use by the biomedical community to study T-type Ca(2+) channels. While the HTS provided numerous hits, these compounds could not be optimized to the required level of potency to be appropriate tool compounds. Therefore, a scaffold hopping approach, guided by SurflexSim, ultimately afforded ML218 (CID 45115620) a selective T-Type Ca(2+) (Ca(v)3.1, Ca(v)3.2, Ca(v)3.3) inhibitor (Ca(v)3.2, IC(50) = 150 nM in Ca(2+) flux; Ca(v)3.2 IC(50) = 310 nM and Ca(v)3.3 IC(50) = 270 nM, respectively in patch clamp electrophysiology) with good DMPK properties, acceptable in vivo rat PK and excellent brain levels. Electrophysiology studies in subthalamic nucleus (STN) neurons demonstrated robust effects of ML218 on the inhibition of T-Type calcium current, inhibition of low threshold spike and rebound burst activity. Based on the basal ganglia circuitry in Parkinson's disease (PD), the effects of ML218 in STN neurons suggest a therapeutic role for T-type Ca(2+) channel inhibitors, and ML218 was found to be orally efficacious in haloperidol-induced catalepsy, a preclinical PD model, with comparable efficacy to an A(2A) antagonist, a clinically validated PD target. ML218 proves to be a powerful new probe to study T-Type Ca(2+) function in vitro and in vivo, and freely available.
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Affiliation(s)
| | | | | | | | | | | | | | - Bende Zou
- AfaSci Research Laboratory, AfaSci, Inc., Redwood, California 94063, United States
| | - Liya Yang
- AfaSci Research Laboratory, AfaSci, Inc., Redwood, California 94063, United States
| | | | | | | | | | | | | | | | | | | | | | | | | | - Ximin Simon Xie
- AfaSci Research Laboratory, AfaSci, Inc., Redwood, California 94063, United States
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28
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A-1048400 is a novel, orally active, state-dependent neuronal calcium channel blocker that produces dose-dependent antinociception without altering hemodynamic function in rats. Biochem Pharmacol 2011; 83:406-18. [PMID: 22153861 DOI: 10.1016/j.bcp.2011.10.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 10/31/2011] [Accepted: 10/31/2011] [Indexed: 11/21/2022]
Abstract
Blockade of voltage-gated Ca²⁺ channels on sensory nerves attenuates neurotransmitter release and membrane hyperexcitability associated with chronic pain states. Identification of small molecule Ca²⁺ channel blockers that produce significant antinociception in the absence of deleterious hemodynamic effects has been challenging. In this report, two novel structurally related compounds, A-686085 and A-1048400, were identified that potently block N-type (IC₅₀=0.8 μM and 1.4 μM, respectively) and T-type (IC₅₀=4.6 μM and 1.2 μM, respectively) Ca²⁺ channels in FLIPR based Ca²⁺ flux assays. A-686085 also potently blocked L-type Ca²⁺ channels (EC₅₀=0.6 μM), however, A-1048400 was much less active in blocking this channel (EC₅₀=28 μM). Both compounds dose-dependently reversed tactile allodynia in a model of capsaicin-induced secondary hypersensitivity with similar potencies (EC₅₀=300-365 ng/ml). However, A-686085 produced dose-related decreases in mean arterial pressure at antinociceptive plasma concentrations in the rat, while A-1048400 did not significantly alter hemodynamic function at supra-efficacious plasma concentrations. Electrophysiological studies demonstrated that A-1048400 blocks native N- and T-type Ca²⁺ currents in rat dorsal root ganglion neurons (IC₅₀=3.0 μM and 1.6 μM, respectively) in a voltage-dependent fashion. In other experimental pain models, A-1048400 dose-dependently attenuated nociceptive, neuropathic and inflammatory pain at doses that did not alter psychomotor or hemodynamic function. The identification of A-1048400 provides further evidence that voltage-dependent inhibition of neuronal Ca²⁺ channels coupled with pharmacological selectivity vs. L-type Ca²⁺ channels can provide robust antinociception in the absence of deleterious effects on hemodynamic or psychomotor function.
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29
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Luo J, Zhu Y, Zhu MX, Hu H. Cell-based calcium assay for medium to high throughput screening of TRP channel functions using FlexStation 3. J Vis Exp 2011:3149. [PMID: 21876521 DOI: 10.3791/3149] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The Molecular Devices' FlexStation 3 is a benchtop multi-mode microplate reader capable of automated fluorescence measurement in multi-well plates. It is ideal for medium- to high-throughput screens in academic settings. It has an integrated fluid transfer module equipped with a multi-channel pipetter and the machine reads one column at a time to monitor fluorescence changes of a variety of fluorescent reagents. For example, FlexStation 3 has been used to study the function of Ca(2+)-permeable ion channels and G-protein coupled receptors by measuring the changes of intracellular free Ca(2+) levels. Transient receptor potential (TRP) channels are a large family of nonselective cation channels that play important roles in many physiological and pathophysiological functions. Most of the TRP channels are calcium permeable and induce calcium influx upon activation. In this video, we demonstrate the application of FlexStation 3 to study the pharmacological profile of the TRPA1 channel, a molecular sensor for numerous noxious stimuli. HEK293 cells transiently or stably expressing human TRPA1 channels, grown in 96-well plates, are loaded with a Ca(2+)-sensitive fluorescent dye, Fluo-4, and real-time fluorescence changes in these cells are measured before and during the application of a TRPA1 agonist using the FLEX mode of the FlexStation 3. The effect of a putative TRPA1 antagonist was also examined. Data are transferred from the SoftMax Pro software to construct concentration-response relationships of TRPA1 activators and inhibitors.
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Affiliation(s)
- Jialie Luo
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, TX, USA
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30
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Inayoshi A, Sugimoto Y, Funahashi J, Takahashi S, Matsubara M, Kusaka H. Mechanism underlying the block of human Cav3.2 T-type Ca2+ channels by benidipine, a dihydropyridine Ca2+ channel blocker. Life Sci 2011; 88:898-907. [PMID: 21466810 DOI: 10.1016/j.lfs.2011.03.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 03/05/2011] [Accepted: 03/26/2011] [Indexed: 11/18/2022]
Abstract
AIMS Benidipine, a dihydropyridine Ca(2+) channel blocker, has been reported to block T-type Ca(2+) channels; however, the mechanism underlying this effect was unclear. In this study, we characterized the mechanism responsible for this blocking activity. Furthermore, the blocking activity was compared between two enantiomers of benidipine, (S, S)- and (R, R)-benidipine. MAIN METHODS Human Ca(v)3.2 (hCa(v)3.2) T-type Ca(2+) channels stably expressed in the human embryonic kidney cell line, HEK-293, were studied in whole-cell patch-clamp recordings and Ca(2+) mobilization assay. KEY FINDINGS In whole-cell patch-clamp recordings, benidipine blocked hCa(v)3.2 T-type Ca(2+) currents elicited by depolarization to a comparable extent as efonidipine. The block was dependent on stimulation frequency and holding potential, but not test potential. Benidipine significantly shifted the steady-state inactivation curve to the hyperpolarizing direction, but had no effect on the activation curve. Benidipine prolonged the recovery from inactivation of hCa(v)3.2 T-type Ca(2+) channels without any effect on the kinetics of activation, inactivation, or deactivation. In the Ca(2+) mobilization assay, benidipine was more potent than efonidipine in blocking Ca(2+) influx through hCa(v)3.2 T-type Ca(2+) channels. (S, S)-Benidipine was more potent than (R, R)-benidipine in blocking hCa(v)3.2 T-type Ca(2+) currents, but there was no difference in blocking the Ca(2+) influx. SIGNIFICANCE We have characterized the blocking activity of benidipine against hCa(v)3.2 Ca(2+) channels and revealed the difference between the two enantiomers of benidipine. The blocking action of benidipine could be mediated by stabilizing hCa(v)3.2 Ca(2+) channels in an inactivated state.
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Affiliation(s)
- Atsushi Inayoshi
- Toxicological Research Laboratories, Research Division, Kyowa Hakko Kirin Co., Ltd., Shizuoka 411-8731, Japan.
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31
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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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32
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Zhou W, Madrid P, Fluitt A, Stahl A, Xie XS. Development and validation of a high-throughput screening assay for human long-chain fatty acid transport proteins 4 and 5. ACTA ACUST UNITED AC 2010; 15:488-97. [PMID: 20448275 DOI: 10.1177/1087057110369700] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Dietary long-chain fatty acid (LCFA) uptake across cell membranes is mediated principally by fatty acid transport proteins (FATPs). Six subtypes of this transporter are differentially expressed throughout the human and rodent body. To facilitate drugs discovery against FATP subtypes, the authors used mammalian cell lines stably expressing the recombinant human FATP4 and 5 and developed a high-throughput screening (HTS) assay using a 96-well fluorometric imaging plate reader (FLIPR). LCFA uptake signal-to-background ratios were between 3- and 5-fold. Two 4-aryl-dihydropyrimidinones, j3 and j5, produced inhibition of FATP4 with a half-maximal inhibitory concentration (IC(50)) of 0.21 and 0.63 microM, respectively, and displayed approximately 100-fold selectivity over FATP5. The US Drug Collection library was screened against the FATP5. A hit rate of around 0.4% was observed with a Z' factor of 0.6 +/- 0.2. Two confirmed hits are bile acids, chenodiol and ursodiol with an IC(50) of 2.4 and 0.22 microM, respectively. To increase throughput, a single time point measurement in a 384-well format was developed using the Analyst HT, and the results are comparable with the 96-well format. In conclusion, the FATP4 and 5 cell-based fluorescence assays are suitable for a primary drug screen, whereas differentiated cell lines are useful for a secondary drug screen.
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Affiliation(s)
- Wei Zhou
- Biosciences Division, SRI International, Menlo Park, CA 94063, USA
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33
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Abstract
For every movement, heartbeat and thought, ion channels need to open and close. It is therefore not surprising that their malfunctioning leads to serious diseases. Currently, only approximately 10% of drugs, with a market value in excess of US$10 billion, act on ion channels. The systematic exploitation of this target class has started, enabled by novel assay technologies and fundamental advances of the structural and mechanistic understanding of channel function. The latter, which was rewarded with the Nobel Prize in 2003, has opened up an avenue for rational drug design. In this review we provide an overview of the current repertoire of screening technologies that has evolved to drive ion channel-targeted drug discovery towards new medicines of the future.
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34
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Abstract
T-type voltage-dependent calcium channels may play an important role in synaptic plasticity, but lack of specific antagonists has hampered investigation into this possible function. We investigated the role of the T-type channel in a canonical model of in-vivo cortical plasticity triggered by monocular deprivation. We identified a compound (TTA-I1) with subnanomolar potency in standard voltage clamp assays and high selectivity for the T-type channel. When infused intracortically, TTA-I1 reduced cortical plasticity triggered by monocular deprivation while preserving normal visual response properties. These results show that the T-type calcium channel plays a central role in cortical plasticity.
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35
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Uebele VN, Nuss CE, Fox SV, Garson SL, Cristescu R, Doran SM, Kraus RL, Santarelli VP, Li Y, Barrow JC, Yang ZQ, Schlegel KAS, Rittle KE, Reger TS, Bednar RA, Lemaire W, Mullen FA, Ballard JE, Tang C, Dai G, McManus OB, Koblan KS, Renger JJ. Positive Allosteric Interaction of Structurally Diverse T-Type Calcium Channel Antagonists. Cell Biochem Biophys 2009; 55:81-93. [DOI: 10.1007/s12013-009-9057-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 06/23/2009] [Indexed: 01/16/2023]
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36
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Belardetti F, Tringham E, Eduljee C, Jiang X, Dong H, Hendricson A, Shimizu Y, Janke DL, Parker D, Mezeyova J, Khawaja A, Pajouhesh H, Fraser RA, Arneric SP, Snutch TP. A Fluorescence-Based High-Throughput Screening Assay for the Identification of T-Type Calcium Channel Blockers. Assay Drug Dev Technol 2009; 7:266-80. [DOI: 10.1089/adt.2009.191] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Francesco Belardetti
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada. Present address: Panora Pharmaceuticals Inc., Vancouver, British Columbia, Canada
| | | | - Cyrus Eduljee
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada
| | - Xinpo Jiang
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada
| | - Haiheng Dong
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada. Present address: WuXi Pharmatech, Shanghai, China
| | - Adam Hendricson
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada. Present address: Bristol-Myers Squibb, Wallingford, Connecticut
| | - Yoko Shimizu
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada. Present address: Centre for Drug Research and Development, University of British Columbia, Vancouver, British Columbia, Canada
| | - Diana L. Janke
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada. Present address: WorkSafeBC, Burnaby, British Columbia, Canada
| | - David Parker
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada
| | - Janette Mezeyova
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada
| | - Afsheen Khawaja
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada
| | - Hassan Pajouhesh
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada
| | - Robert A. Fraser
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada. Present address: Centre for Drug Research and Development, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stephen P. Arneric
- Neuromed Pharmaceuticals Ltd., Vancouver, British Columbia, Canada. Present address: Eli Lilly & Company, Indianapolis, Indiana
| | - Terrance P. Snutch
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
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37
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Chiang CS, Huang CH, Chieng H, Chang YT, Chang D, Chen JJ, Chen YC, Chen YH, Shin HS, Campbell KP, Chen CC. The Ca
V
3.2 T-Type Ca
2+
Channel Is Required for Pressure Overload–Induced Cardiac Hypertrophy in Mice. Circ Res 2009; 104:522-30. [DOI: 10.1161/circresaha.108.184051] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Voltage-gated T-type Ca
2+
channels (T-channels) are normally expressed during embryonic development in ventricular myocytes but are undetectable in adult ventricular myocytes. Interestingly, T-channels are reexpressed in hypertrophied or failing hearts. It is unclear whether T-channels play a role in the pathogenesis of cardiomyopathy and what the mechanism might be. Here we show that the α
1H
voltage-gated T-type Ca
2+
channel (Ca
v
3.2) is involved in the pathogenesis of cardiac hypertrophy via the activation of calcineurin/nuclear factor of activated T cells (NFAT) pathway. Specifically, pressure overload–induced hypertrophy was severely suppressed in mice deficient for Ca
v
3.2 (Ca
v
3.2
−/−
) but not in mice deficient for Ca
v
3.1 (Ca
v
3.1
−/−
). Angiotensin II–induced cardiac hypertrophy was also suppressed in Ca
v
3.2
−/−
mice. Consistent with these findings, cultured neonatal myocytes isolated from Ca
v
3.2
−/−
mice fail to respond hypertrophic stimulation by treatment with angiotensin II. Together, these results demonstrate the importance of Ca
v
3.2 in the development of cardiac hypertrophy both in vitro and in vivo. To test whether Ca
v
3.2 mediates the hypertrophic response through the calcineurin/NFAT pathway, we generated Ca
v
3.2
−/−
, NFAT-luciferase reporter mice and showed that NFAT-luciferase reporter activity failed to increase after pressure overload in the Ca
v
3.2
−/−
/NFAT-Luc mice. Our results provide strong genetic evidence that Ca
v
3.2 indeed plays a pivotal role in the induction of calcineurin/NFAT hypertrophic signaling and is crucial for the activation of pathological cardiac hypertrophy.
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Affiliation(s)
- Chien-Sung Chiang
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
| | - Ching-Hui Huang
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
| | - Hockling Chieng
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
| | - Ya-Ting Chang
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
| | - Dory Chang
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
| | - Ji-Jr Chen
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
| | - Yong-Cyuan Chen
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
| | - Yen-Hui Chen
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
| | - Hee-Sup Shin
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
| | - Kevin P. Campbell
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
| | - Chien-Chang Chen
- From the Institute of Biomedical Sciences (C.-S.C., C.-H.H., H.C., Y.-T.C., D.C., J.-J.C., Y.-C.C.,Y.-H.C., C.-C.C.), Academia Sinica, Taipei, Taiwan; Graduate Institute of Life Sciences (C.-H.H., C.-C.C.), National Defense Medical Center, Taipei, Taiwan; Center for Neural Science (H.-S.S.), Korea Institute of Science and Technology, Seoul, Korea; and Department of Physiology and Biophysics and Department of Neurology (K.P.C.), Howard Hughes Medical Institute, University of Iowa, Iowa City
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38
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Perez-Reyes E, Van Deusen AL, Vitko I. Molecular pharmacology of human Cav3.2 T-type Ca2+ channels: block by antihypertensives, antiarrhythmics, and their analogs. J Pharmacol Exp Ther 2008; 328:621-7. [PMID: 18974361 DOI: 10.1124/jpet.108.145672] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Antihypertensive drugs of the "calcium channel blocker" or "calcium antagonist" class have been used to establish the physiological role of L-type Ca(2+) channels in vascular smooth muscle. In contrast, there has been limited progress on the pharmacology T-type Ca(2+) channels. T-type channels play a role in cardiac pacemaking, aldosterone secretion, and renal hemodynamics, leading to the hypothesis that mixed T- and L-type blockers may have therapeutic advantages over selective L-type blockers. The goal of this study was to identify compounds that block the Ca(v)3.2 T-type channel with high affinity, focusing on two classes of compounds: phenylalkylamines (e.g., mibefradil) and dihydropyridines (e.g., efonidipine). Compounds were tested using a validated Ca(2+) influx assay into a cell line expressing recombinant Ca(v)3.2 channels. This study identified four clinically approved antihypertensive drugs (efonidipine, felodipine, isradipine, and nitrendipine) as potent T-channel blockers (IC(50) < 3 microM). In contrast, other widely prescribed dihydropyridines, such as amlodipine and nifedipine, were 10-fold less potent, making them a more appropriate choice in research studies on the role of L-type currents. In summary, the present results support the notion that many available antihypertensive drugs block a substantial fraction of T-current at therapeutically relevant concentrations, contributing to their mechanism of action.
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Affiliation(s)
- Edward Perez-Reyes
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA.
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Dai G, Haedo RJ, Warren VA, Ratliff KS, Bugianesi RM, Rush A, Williams ME, Herrington J, Smith MM, McManus OB, Swensen AM. A High-Throughput Assay for Evaluating State Dependence and Subtype Selectivity of Cav2 Calcium Channel Inhibitors. Assay Drug Dev Technol 2008; 6:195-212. [DOI: 10.1089/adt.2008.136] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Affiliation(s)
- Ge Dai
- Merck Research Laboratories, Rahway, NJ
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