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Rogers M, Obergrussberger A, Kondratskyi A, Fertig N. Using automated patch clamp electrophysiology platforms in ion channel drug discovery: an industry perspective. Expert Opin Drug Discov 2024; 19:523-535. [PMID: 38481119 DOI: 10.1080/17460441.2024.2329104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/06/2024] [Indexed: 04/25/2024]
Abstract
INTRODUCTION Automated patch clamp (APC) is now well established as a mature technology for ion channel drug discovery in academia, biotech and pharma companies, and in contract research organizations (CRO), for a variety of applications including channelopathy research, compound screening, target validation and cardiac safety testing. AREAS COVERED Ion channels are an important class of drugged and approved drug targets. The authors present a review of the current state of ion channel drug discovery along with new and exciting developments in ion channel research involving APC. This includes topics such as native and iPSC-derived cells in ion channel drug discovery, channelopathy research, organellar and biologics in ion channel drug discovery. EXPERT OPINION It is our belief that APC will continue to play a critical role in ion channel drug discovery, not only in 'classical' hit screening, target validation and cardiac safety testing, but extending these applications to include high throughput organellar recordings and optogenetics. In this way, with advancements in APC capabilities and applications, together with high resolution cryo-EM structures, ion channel drug discovery will be re-invigorated, leading to a growing list of ion channel ligands in clinical development.
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Affiliation(s)
- Marc Rogers
- Albion Drug Discovery Services Ltd, Cambridge, UK
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Nasilli G, Yiangou L, Palandri C, Cerbai E, Davis RP, Verkerk AO, Casini S, Remme CA. Beneficial effects of chronic mexiletine treatment in a human model of SCN5A overlap syndrome. Europace 2023; 25:euad154. [PMID: 37369559 PMCID: PMC10299896 DOI: 10.1093/europace/euad154] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023] Open
Abstract
AIMS SCN5A mutations are associated with various cardiac phenotypes, including long QT syndrome type 3 (LQT3), Brugada syndrome (BrS), and cardiac conduction disease (CCD). Certain mutations, such as SCN5A-1795insD, lead to an overlap syndrome, with patients exhibiting both features of BrS/CCD [decreased sodium current (INa)] and LQT3 (increased late INa). The sodium channel blocker mexiletine may acutely decrease LQT3-associated late INa and chronically increase peak INa associated with SCN5A loss-of-function mutations. However, most studies have so far employed heterologous expression systems and high mexiletine concentrations. We here investigated the effects of a therapeutic dose of mexiletine on the mixed phenotype associated with the SCN5A-1795insD mutation in HEK293A cells and human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). METHODS AND RESULTS To assess only the chronic effects on trafficking, HEK293A cells transfected with wild-type (WT) SCN5A or SCN5A-1795insD were incubated for 48 h with 10 µm mexiletine followed by wash-out, which resulted in an increased peak INa for both SCN5A-WT and SCN5A-1795insD and an increased late INa for SCN5A-1795insD. Acute re-exposure of HEK293A cells to 10 µm mexiletine did not impact on peak INa but significantly decreased SCN5A-1795insD late INa. Chronic incubation of SCN5A-1795insD hiPSC-CMs with mexiletine followed by wash-out increased peak INa, action potential (AP) upstroke velocity, and AP duration. Acute re-exposure did not impact on peak INa or AP upstroke velocity, but significantly decreased AP duration. CONCLUSION These findings demonstrate for the first time the therapeutic benefit of mexiletine in a human cardiomyocyte model of SCN5A overlap syndrome.
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Affiliation(s)
- Giovanna Nasilli
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Heart Centre, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, The Netherlands
| | - Loukia Yiangou
- Department of Anatomy and Embryology, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Chiara Palandri
- Department NeuroFarBa, University of Florence, Viale Gaetano Pieraccini 6, 50139, Florence, Italy
| | - Elisabetta Cerbai
- Department NeuroFarBa, University of Florence, Viale Gaetano Pieraccini 6, 50139, Florence, Italy
| | - Richard P Davis
- Department of Anatomy and Embryology, Leiden University Medical Center, Albinusdreef 2, 2300 RC, Leiden, The Netherlands
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), Albinusdreef 2, 2300 RC, Leiden, The Netherlands
| | - Arie O Verkerk
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Heart Centre, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, The Netherlands
- Department of Medical Biology, Amsterdam University Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Simona Casini
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Heart Centre, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, The Netherlands
| | - Carol Ann Remme
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Heart Centre, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam, The Netherlands
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Rapedius M, Obergrussberger A, Humphries ESA, Scholz S, Rinke-Weiss I, Goetze TA, Brinkwirth N, Rotordam MG, Strassmaier T, Randolph A, Friis S, Liutkute A, Seibertz F, Voigt N, Fertig N. There is no F in APC: Using physiological fluoride-free solutions for high throughput automated patch clamp experiments. Front Mol Neurosci 2022; 15:982316. [PMID: 36072300 PMCID: PMC9443850 DOI: 10.3389/fnmol.2022.982316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 07/26/2022] [Indexed: 11/13/2022] Open
Abstract
Fluoride has been used in the internal recording solution for manual and automated patch clamp experiments for decades because it helps to improve the seal resistance and promotes longer lasting recordings. In manual patch clamp, fluoride has been used to record voltage-gated Na (NaV) channels where seal resistance and access resistance are critical for good voltage control. In automated patch clamp, suction is applied from underneath the patch clamp chip to attract a cell to the hole and obtain a good seal. Since the patch clamp aperture cannot be moved to improve the seal like the patch clamp pipette in manual patch clamp, automated patch clamp manufacturers use internal fluoride to improve the success rate for obtaining GΩ seals. However, internal fluoride can affect voltage-dependence of activation and inactivation, as well as affecting internal second messenger systems and therefore, it is desirable to have the option to perform experiments using physiological, fluoride-free internal solution. We have developed an approach for high throughput fluoride-free recordings on a 384-well based automated patch clamp system with success rates >40% for GΩ seals. We demonstrate this method using hERG expressed in HEK cells, as well as NaV1.5, NaV1.7, and KCa3.1 expressed in CHO cells. We describe the advantages and disadvantages of using fluoride and provide examples of where fluoride can be used, where caution should be exerted and where fluoride-free solutions provide an advantage over fluoride-containing solutions.
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Affiliation(s)
- Markus Rapedius
- Nanion Technologies GmbH, Munich, Germany
- *Correspondence: Markus Rapedius,
| | | | | | | | | | | | | | | | | | | | | | - Aiste Liutkute
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
- German Center for Cardiovascular Research, Partner Site Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells”, University of Göttingen, Göttingen, Germany
| | - Fitzwilliam Seibertz
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
- German Center for Cardiovascular Research, Partner Site Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells”, University of Göttingen, Göttingen, Germany
| | - Niels Voigt
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
- German Center for Cardiovascular Research, Partner Site Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells”, University of Göttingen, Göttingen, Germany
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Govorunova EG, Sineshchekov OA, Brown LS, Spudich JL. Biophysical characterization of light-gated ion channels using planar automated patch clamp. Front Mol Neurosci 2022; 15:976910. [PMID: 36017077 PMCID: PMC9396214 DOI: 10.3389/fnmol.2022.976910] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 07/21/2022] [Indexed: 01/09/2023] Open
Abstract
Channelrhodopsins (ChRs) are proteins that guide phototaxis in protists and exhibit light-gated channel conductance when their genes are heterologously expressed in mammalian cells. ChRs are widely used as molecular tools to control neurons and cardiomyocytes with light (optogenetics). Cation- and anion-selective ChRs (CCRs and ACRs, respectively) enable stimulation and inhibition of neuronal activity by depolarization and hyperpolarization of the membrane, respectively. More than 400 natural ChR variants have been identified so far, and high-throughput polynucleotide sequencing projects add many more each year. However, electrophysiological characterization of new ChRs lags behind because it is mostly done by time-consuming manual patch clamp (MPC). Here we report using a high-throughput automated patch clamp (APC) platform, SyncroPatch 384i from Nanion Technologies, for ChR research. We find that this instrument can be used for determination of the light intensity dependence and current-voltage relationships in ChRs and discuss its advantages and limitations.
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Affiliation(s)
- Elena G. Govorunova
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, The University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, United States
| | - Oleg A. Sineshchekov
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, The University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, United States
| | - Leonid S. Brown
- Biophysics Interdepartmental Group, Department of Physics, University of Guelph, Guelph, ON, Canada
| | - John L. Spudich
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, The University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, United States
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Ingleby-Talecki L, van Dijkman SC, Oosterholt SP, Della Pasqua O, Winter C, Cunnington M, Rebar L, Forero-Schwanhaeuser S, Patel V, Cooper JA, Bahinski A, Chaudhary KW. Cardiac sodium channel inhibition by lamotrigine: in vitro characterization and clinical implications. Clin Transl Sci 2022; 15:1978-1989. [PMID: 35579204 PMCID: PMC9372421 DOI: 10.1111/cts.13311] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 04/26/2022] [Accepted: 05/02/2022] [Indexed: 11/26/2022] Open
Abstract
Lamotrigine, approved for use as an antiseizure medication as well as the treatment of bipolar disorder, inhibits sodium channels in the brain to reduce repetitive neuronal firing and pathological release of glutamate. The shared homology of sodium channels and lack of selectivity associated with channel blocking agents can cause slowing of cardiac conduction and increased proarrhythmic potential. The Vaughan‐Williams classification system differentiates sodium channel blockers using biophysical properties of binding. As such, Class Ib inhibitors, including mexiletine, do not slow cardiac conduction as measured by the electrocardiogram, at therapeutically relevant exposure. Our goal was to characterize the biophysical properties of NaV1.5 block and to support the observed clinical safety of lamotrigine. We used HEK‐293 cells stably expressing the hNaV1.5 channel and voltage clamp electrophysiology to quantify the potency (half‐maximal inhibitory concentration) against peak and late channel current, on‐/off‐rate binding kinetics, voltage‐dependence, and tonic block of the cardiac sodium channel by lamotrigine; and compared to clinically relevant Class Ia (quinidine), Ib (mexiletine), and Ic (flecainide) inhibitors. Lamotrigine blocked peak and late NaV1.5 current at therapeutically relevant exposure, with rapid kinetics and biophysical properties similar to the class Ib inhibitor mexiletine. However, no clinically meaningful prolongation in QRS or PR interval was observed in healthy subjects in a new analysis of a previously reported thorough QT clinical trial (SCA104648). In conclusion, the weak NaV1.5 block and rapid kinetics do not translate into clinically relevant conduction slowing at therapeutic exposure and support the clinical safety of lamotrigine in patients suffering from epilepsy and bipolar disorder.
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Affiliation(s)
| | | | | | | | | | | | - Linda Rebar
- GSK US Regulatory Affairs, Collegeville, PA 19426, USA
| | | | - Vickas Patel
- Former GSK Employee, Collegeville, PA 19426, USA
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Safety pharmacology during the COVID pandemic. J Pharmacol Toxicol Methods 2021; 111:107089. [PMID: 34182120 PMCID: PMC8233455 DOI: 10.1016/j.vascn.2021.107089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 06/18/2021] [Indexed: 11/22/2022]
Abstract
This editorial summarizes the content of the current themed issue of J Pharmacol Toxicol Methods derived from the 2020 Annual Safety Pharmacology Society (SPS) meeting that was held virtually September 14–17, 2020 due to the ongoing COVID-19 global pandemic. A selection of articles arising from the virtual meeting is summarized. Like previous years they continue to reflect current areas of innovation in SP including new methodologies to predict human safety, best practices for IKr current measurement, and best practice considerations for the conduct of in vivo nonclinical QT studies. The meeting included scientific content from 94 abstracts (reproduced in the current volume of J Pharmacol Toxicol Methods). This continued innovation reflects a rubric in SP that identifies problems, seeks solutions and, importantly, validates the solutions.
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