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Campàs M, Reverté J, Tudó À, Alkassar M, Diogène J, Sureda FX. Automated Patch Clamp for the Detection of Tetrodotoxin in Pufferfish Samples. Mar Drugs 2024; 22:176. [PMID: 38667793 PMCID: PMC11050952 DOI: 10.3390/md22040176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/10/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Tetrodotoxin (TTX) is a marine toxin responsible for many intoxications around the world. Its presence in some pufferfish species and, as recently reported, in shellfish, poses a serious health concern. Although TTX is not routinely monitored, there is a need for fast, sensitive, reliable, and simple methods for its detection and quantification. In this work, we describe the use of an automated patch clamp (APC) system with Neuro-2a cells for the determination of TTX contents in pufferfish samples. The cells showed an IC50 of 6.4 nM for TTX and were not affected by the presence of muscle, skin, liver, and gonad tissues of a Sphoeroides pachygaster specimen (TTX-free) when analysed at 10 mg/mL. The LOD achieved with this technique was 0.05 mg TTX equiv./kg, which is far below the Japanese regulatory limit of 2 mg TTX equiv./kg. The APC system was applied to the analysis of extracts of a Lagocephalus sceleratus specimen, showing TTX contents that followed the trend of gonads > liver > skin > muscle. The APC system, providing an in vitro toxicological approach, offers the advantages of being sensitive, rapid, and reliable for the detection of TTX-like compounds in seafood.
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Affiliation(s)
- Mònica Campàs
- IRTA, Marine and Continental Waters (AMiC) Programme, Ctra. Poble Nou del Delta, km. 5.5, 43540 La Ràpita, Spain; (J.R.); (M.A.); (J.D.)
| | - Jaume Reverté
- IRTA, Marine and Continental Waters (AMiC) Programme, Ctra. Poble Nou del Delta, km. 5.5, 43540 La Ràpita, Spain; (J.R.); (M.A.); (J.D.)
- Department of Basic Medical Sciences, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain;
| | - Àngels Tudó
- Department of Basic Medical Sciences, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain;
| | - Mounira Alkassar
- IRTA, Marine and Continental Waters (AMiC) Programme, Ctra. Poble Nou del Delta, km. 5.5, 43540 La Ràpita, Spain; (J.R.); (M.A.); (J.D.)
- Department of Basic Medical Sciences, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain;
| | - Jorge Diogène
- IRTA, Marine and Continental Waters (AMiC) Programme, Ctra. Poble Nou del Delta, km. 5.5, 43540 La Ràpita, Spain; (J.R.); (M.A.); (J.D.)
| | - Francesc X. Sureda
- Department of Basic Medical Sciences, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain;
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Platonov M, Maximyuk O, Rayevsky A, Hurmach V, Iegorova O, Naumchyk V, Bulgakov E, Cherninskyi A, Ozheredov D, Ryabukhin SV, Krishtal O, Volochnyuk DM. 4-(Azolyl)-Benzamidines as a Novel Chemotype for ASIC1a Inhibitors. Int J Mol Sci 2024; 25:3584. [PMID: 38612396 PMCID: PMC11011685 DOI: 10.3390/ijms25073584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 03/03/2024] [Accepted: 03/13/2024] [Indexed: 04/14/2024] Open
Abstract
Acid-sensing ion channels (ASICs) play a key role in the perception and response to extracellular acidification changes. These proton-gated cation channels are critical for neuronal functions, like learning and memory, fear, mechanosensation and internal adjustments like synaptic plasticity. Moreover, they play a key role in neuronal degeneration, ischemic neuronal injury, seizure termination, pain-sensing, etc. Functional ASICs are homo or heterotrimers formed with (ASIC1-ASIC3) homologous subunits. ASIC1a, a major ASIC isoform in the central nervous system (CNS), possesses an acidic pocket in the extracellular region, which is a key regulator of channel gating. Growing data suggest that ASIC1a channels are a potential therapeutic target for treating a variety of neurological disorders, including stroke, epilepsy and pain. Many studies were aimed at identifying allosteric modulators of ASIC channels. However, the regulation of ASICs remains poorly understood. Using all available crystal structures, which correspond to different functional states of ASIC1, and a molecular dynamics simulation (MD) protocol, we analyzed the process of channel inactivation. Then we applied a molecular docking procedure to predict the protein conformation suitable for the amiloride binding. To confirm the effect of its sole active blocker against the ASIC1 state transition route we studied the complex with another MD simulation run. Further experiments evaluated various compounds in the Enamine library that emerge with a detectable ASIC inhibitory activity. We performed a detailed analysis of the structural basis of ASIC1a inhibition by amiloride, using a combination of in silico approaches to visualize its interaction with the ion pore in the open state. An artificial activation (otherwise, expansion of the central pore) causes a complex modification of the channel structure, namely its transmembrane domain. The output protein conformations were used as a set of docking models, suitable for a high-throughput virtual screening of the Enamine chemical library. The outcome of the virtual screening was confirmed by electrophysiological assays with the best results shown for three hit compounds.
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Affiliation(s)
- Maksym Platonov
- Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Zabolotnogo Str., 150, 03143 Kyiv, Ukraine; (M.P.); (V.H.)
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
| | - Oleksandr Maximyuk
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Str., 01024 Kyiv, Ukraine; (O.M.); (O.I.); (A.C.); (O.K.)
| | - Alexey Rayevsky
- Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Zabolotnogo Str., 150, 03143 Kyiv, Ukraine; (M.P.); (V.H.)
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
- Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Osypovskoho Str., 2A, 04123 Kyiv, Ukraine;
| | - Vasyl Hurmach
- Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Zabolotnogo Str., 150, 03143 Kyiv, Ukraine; (M.P.); (V.H.)
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
| | - Olena Iegorova
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Str., 01024 Kyiv, Ukraine; (O.M.); (O.I.); (A.C.); (O.K.)
| | - Vasyl Naumchyk
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
- Institute of High Technologies, Taras Shevchenko National University of Kyiv, Volodymyrska Street 60, 01601 Kyiv, Ukraine
| | - Elijah Bulgakov
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
- Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Osypovskoho Str., 2A, 04123 Kyiv, Ukraine;
| | - Andrii Cherninskyi
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Str., 01024 Kyiv, Ukraine; (O.M.); (O.I.); (A.C.); (O.K.)
| | - Danil Ozheredov
- Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Osypovskoho Str., 2A, 04123 Kyiv, Ukraine;
| | - Serhiy V. Ryabukhin
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
- Institute of High Technologies, Taras Shevchenko National University of Kyiv, Volodymyrska Street 60, 01601 Kyiv, Ukraine
- Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Academik Kukhar Str., 02660 Kyiv, Ukraine
| | - Oleg Krishtal
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Str., 01024 Kyiv, Ukraine; (O.M.); (O.I.); (A.C.); (O.K.)
| | - Dmytro M. Volochnyuk
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
- Institute of High Technologies, Taras Shevchenko National University of Kyiv, Volodymyrska Street 60, 01601 Kyiv, Ukraine
- Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Academik Kukhar Str., 02660 Kyiv, Ukraine
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3
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Dallas ML, Bell D. Advances in ion channel high throughput screening: where are we in 2023? Expert Opin Drug Discov 2024; 19:331-337. [PMID: 38108110 DOI: 10.1080/17460441.2023.2294948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
INTRODUCTION Automated Patch Clamp (APC) technology has become an integral element in ion channel research, drug discovery and development pipelines to overcome the use of the highly time-consuming manual patch clamp (MPC) procedures. This automated technology offers increased throughput and promises a new model in obtaining ion channel recordings, which has significant relevance to the development of novel therapies and safety profiling of candidate therapeutic compounds. AREAS COVERED This article reviews the recent innovations in APC technology, including platforms, and highlights how they have facilitated usage in both industry and academia. The review also provides an overview of the ion channel research endeavors and how APC platforms have contributed to the understanding of ion channel research, pharmacological tools and therapeutics. Furthermore, the authors provide their opinion on the challenges and goals for APC technology going forward to accelerate academic research and drug discovery across a host of therapeutic areas. EXPERT OPINION It is clear that APC technology has progressed drug discovery programs, specifically in the field of neuroscience and cardiovascular research. The challenge for the future is to keep pace with fundamental research and improve translation of the large datasets obtained.
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Affiliation(s)
- Mark L Dallas
- Reading School of Pharmacy, University of Reading, Reading, UK
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Bloothooft M, Verbruggen B, Seibertz F, van der Heyden MAG, Voigt N, de Boer TP. Recording ten-fold larger I Kr conductances with automated patch clamping using equimolar Cs + solutions. Front Physiol 2024; 15:1298340. [PMID: 38328302 PMCID: PMC10847579 DOI: 10.3389/fphys.2024.1298340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 01/09/2024] [Indexed: 02/09/2024] Open
Abstract
Background: The rapid delayed rectifier potassium current (IKr) is important for cardiac repolarization and is most often involved in drug-induced arrhythmias. However, accurately measuring this current can be challenging in human-induced pluripotent stem cell (hiPSC)-derived cardiomyocytes because of its small current density. Interestingly, the ion channel conducting IKr, hERG channel, is not only permeable to K+ ions but also to Cs+ ions when present in equimolar concentrations inside and outside of the cell. Methods: In this study, IhERG was measured from Chinese hamster ovary (CHO)-hERG cells and hiPSC-CM using either Cs+ or K+ as the charge carrier. Equimolar Cs+ has been used in the literature in manual patch-clamp experiments, and here, we apply this approach using automated patch-clamp systems. Four different (pre)clinical drugs were tested to compare their effects on Cs+- and K+-based currents. Results: Using equimolar Cs+ solutions gave rise to approximately ten-fold larger hERG conductances. Comparison of Cs+- and K+-mediated currents upon application of dofetilide, desipramine, moxifloxacin, or LUF7244 revealed many similarities in inhibition or activation properties of the drugs studied. Using equimolar Cs+ solutions gave rise to approximately ten-fold larger hERG conductances. In hiPSC-CM, the Cs+-based conductance is larger compared to the known K+-based conductance, and the Cs+ hERG conductance can be inhibited similarly to the K+-based conductance. Conclusion: Using equimolar Cs+ instead of K+ for IhERG measurements in an automated patch-clamp system gives rise to a new method by which, for example, quick scans can be performed on effects of drugs on hERG currents. This application is specifically relevant when such experiments are performed using cells which express small IKr current densities in combination with small membrane capacitances.
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Affiliation(s)
- Meye Bloothooft
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Bente Verbruggen
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Fitzwilliam Seibertz
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Georg-August University Göttingen, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
- Nanion Technologies GmbH, Munich, Germany
| | - Marcel A. G. van der Heyden
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Niels Voigt
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Georg-August University Göttingen, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), University of Göttingen, Göttingen, Germany
| | - Teun P. de Boer
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
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Frosio A, Micaglio E, Polsinelli I, Calamaio S, Melgari D, Prevostini R, Ghiroldi A, Binda A, Carrera P, Villa M, Mastrocinque F, Presi S, Salerno R, Boccellino A, Anastasia L, Ciconte G, Ricagno S, Pappone C, Rivolta I. Unravelling Novel SCN5A Mutations Linked to Brugada Syndrome: Functional, Structural, and Genetic Insights. Int J Mol Sci 2023; 24:15089. [PMID: 37894777 PMCID: PMC10606416 DOI: 10.3390/ijms242015089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/08/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023] Open
Abstract
Brugada Syndrome (BrS) is a rare inherited cardiac arrhythmia causing potentially fatal ventricular tachycardia or fibrillation, mainly occurring during rest or sleep in young individuals without heart structural issues. It increases the risk of sudden cardiac death, and its characteristic feature is an abnormal ST segment elevation on the ECG. While BrS has diverse genetic origins, a subset of cases can be conducted to mutations in the SCN5A gene, which encodes for the Nav1.5 sodium channel. Our study focused on three novel SCN5A mutations (p.A344S, p.N347K, and p.D349N) found in unrelated BrS families. Using patch clamp experiments, we found that these mutations disrupted sodium currents: p.A344S reduced current density, while p.N347K and p.D349N completely abolished it, leading to altered voltage dependence and inactivation kinetics when co-expressed with normal channels. We also explored the effects of mexiletine treatment, which can modulate ion channel function. Interestingly, the p.N347K and p.D349N mutations responded well to the treatment, rescuing the current density, while p.A344S showed a limited response. Structural analysis revealed these mutations were positioned in key regions of the channel, impacting its stability and function. This research deepens our understanding of BrS by uncovering the complex relationship between genetic mutations, ion channel behavior, and potential therapeutic interventions.
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Affiliation(s)
- Anthony Frosio
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
| | - Emanuele Micaglio
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
- Arrhythmia and Electrophysiology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (F.M.); (A.B.)
| | - Ivan Polsinelli
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
| | - Serena Calamaio
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
| | - Dario Melgari
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
| | - Rachele Prevostini
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
| | - Andrea Ghiroldi
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
- Laboratory of Stem Cells for Tissue Engineering, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy
| | - Anna Binda
- School of Medicine and Surgery, University of Milano-Bicocca, Via Cadore, 48, 20900 Monza, Italy;
| | - Paola Carrera
- Laboratory of Clinical Molecular Genetics and Cytogenetics, Unit of Genomics for Diagnosis of Human Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; (P.C.); (S.P.)
| | - Marco Villa
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
| | - Flavio Mastrocinque
- Arrhythmia and Electrophysiology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (F.M.); (A.B.)
| | - Silvia Presi
- Laboratory of Clinical Molecular Genetics and Cytogenetics, Unit of Genomics for Diagnosis of Human Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; (P.C.); (S.P.)
| | - Raffaele Salerno
- Faculty of Medicine and Surgery, Vita-Salute San Raffaele University, Via Olgettina, 58, 20132 Milan, Italy;
| | - Antonio Boccellino
- Arrhythmia and Electrophysiology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (F.M.); (A.B.)
| | - Luigi Anastasia
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
- Laboratory of Stem Cells for Tissue Engineering, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy
- Faculty of Medicine and Surgery, Vita-Salute San Raffaele University, Via Olgettina, 58, 20132 Milan, Italy;
| | - Giuseppe Ciconte
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
- Arrhythmia and Electrophysiology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (F.M.); (A.B.)
- Faculty of Medicine and Surgery, Vita-Salute San Raffaele University, Via Olgettina, 58, 20132 Milan, Italy;
| | - Stefano Ricagno
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
- Department of Biosciences, Università degli Studi di Milano, Via Celoria, 26, 20133 Milan, Italy
| | - Carlo Pappone
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
- Arrhythmia and Electrophysiology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (F.M.); (A.B.)
- Faculty of Medicine and Surgery, Vita-Salute San Raffaele University, Via Olgettina, 58, 20132 Milan, Italy;
| | - Ilaria Rivolta
- Institute of Molecular and Translational Cardiology (IMTC), IRCCS Policlinico San Donato, 20097 San Donato Milanese, Italy; (A.F.); (E.M.); (I.P.); (S.C.); (D.M.); (R.P.); (A.G.); (M.V.); (L.A.); (G.C.); (S.R.); (C.P.)
- School of Medicine and Surgery, University of Milano-Bicocca, Via Cadore, 48, 20900 Monza, Italy;
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6
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Ismaili D, Schulz C, Horváth A, Koivumäki JT, Mika D, Hansen A, Eschenhagen T, Christ T. Human induced pluripotent stem cell-derived cardiomyocytes as an electrophysiological model: Opportunities and challenges-The Hamburg perspective. Front Physiol 2023; 14:1132165. [PMID: 36875015 PMCID: PMC9978010 DOI: 10.3389/fphys.2023.1132165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 02/06/2023] [Indexed: 02/18/2023] Open
Abstract
Models based on human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are proposed in almost any field of physiology and pharmacology. The development of human induced pluripotent stem cell-derived cardiomyocytes is expected to become a step forward to increase the translational power of cardiovascular research. Importantly they should allow to study genetic effects on an electrophysiological background close to the human situation. However, biological and methodological issues revealed when human induced pluripotent stem cell-derived cardiomyocytes were used in experimental electrophysiology. We will discuss some of the challenges that should be considered when human induced pluripotent stem cell-derived cardiomyocytes will be used as a physiological model.
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Affiliation(s)
- Djemail Ismaili
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Cardiology, University Heart and Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Carl Schulz
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - András Horváth
- Translational Cardiology, Department of Cardiology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Jussi T Koivumäki
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Delphine Mika
- Inserm, UMR-S 1180, Université Paris-Saclay, Orsay, France
| | - Arne Hansen
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Thomas Eschenhagen
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Torsten Christ
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
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7
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Jahanfar F, Sadofsky L, Morice A, D’Amico M. Nebivolol as a Potent TRPM8 Channel Blocker: A Drug-Screening Approach through Automated Patch Clamping and Ligand-Based Virtual Screening. Membranes (Basel) 2022; 12:954. [PMID: 36295712 PMCID: PMC9609861 DOI: 10.3390/membranes12100954] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 09/19/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
Transient Receptor Potential Melastatin 8 (TRPM8) from the melastatin TRP channel subfamily is a non-selective Ca2+-permeable ion channel with multimodal gating which can be activated by low temperatures and cooling compounds, such as menthol and icilin. Different conditions such as neuropathic pain, cancer, overactive bladder syndrome, migraine, and chronic cough have been linked to the TRPM8 mode of action. Despite the several potent natural and synthetic inhibitors of TRPM8 that have been identified, none of them have been approved for clinical use. The aim of this study was to discover novel blocking TRPM8 agents using automated patch clamp electrophysiology combined with a ligand-based virtual screening based on the SwissSimilarity platform. Among the compounds we have tested, nebivolol and carvedilol exhibited the greatest inhibitory effect, with an IC50 of 0.97 ± 0.15 µM and 9.1 ± 0.6 µM, respectively. This study therefore provides possible candidates for future drug repurposing and suggests promising lead compounds for further optimization as inhibitors of the TRPM8 ion channel.
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Affiliation(s)
- Farhad Jahanfar
- Di.V.A.L. Toscana S.r.l., Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy
| | - Laura Sadofsky
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, UK
| | - Alyn Morice
- Respiratory Research Group, Hull York Medical School, Castle Hill Hospital, Cottingham HU16 5JQ, UK
| | - Massimo D’Amico
- Di.V.A.L. Toscana S.r.l., Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
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8
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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] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [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,*Correspondence: John L. Spudich,
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9
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Ng CA, Ullah R, Farr J, Hill AP, Kozek KA, Vanags LR, Mitchell DW, Kroncke BM, Vandenberg JI. A massively parallel assay accurately discriminates between functionally normal and abnormal variants in a hotspot domain of KCNH2. Am J Hum Genet 2022; 109:1208-1216. [PMID: 35688148 PMCID: PMC9300756 DOI: 10.1016/j.ajhg.2022.05.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 05/03/2022] [Indexed: 01/09/2023] Open
Abstract
Many genes, including KCNH2, contain "hotspot" domains associated with a high density of variants associated with disease. This has led to the suggestion that variant location can be used as evidence supporting classification of clinical variants. However, it is not known what proportion of all potential variants in hotspot domains cause loss of function. Here, we have used a massively parallel trafficking assay to characterize all single-nucleotide variants in exon 2 of KCNH2, a known hotspot for variants that cause long QT syndrome type 2 and an increased risk of sudden cardiac death. Forty-two percent of KCNH2 exon 2 variants caused at least 50% reduction in protein trafficking, and 65% of these trafficking-defective variants exerted a dominant-negative effect when co-expressed with a WT KCNH2 allele as assessed using a calibrated patch-clamp electrophysiology assay. The massively parallel trafficking assay was more accurate (AUC of 0.94) than bioinformatic prediction tools (REVEL and CardioBoost, AUC of 0.81) in discriminating between functionally normal and abnormal variants. Interestingly, over half of variants in exon 2 were found to be functionally normal, suggesting a nuanced interpretation of variants in this "hotspot" domain is necessary. Our massively parallel trafficking assay can provide this information prospectively.
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Affiliation(s)
- Chai-Ann Ng
- Mark Cowley Lidwill Research Program in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; School of Clinical Medicine, UNSW Sydney, Darlinghurst, NSW, Australia
| | - Rizwan Ullah
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Jessica Farr
- Mark Cowley Lidwill Research Program in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; School of Computer Science and Engineering, UNSW Sydney, Kensington, NSW, Australia
| | - Adam P Hill
- Mark Cowley Lidwill Research Program in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; School of Clinical Medicine, UNSW Sydney, Darlinghurst, NSW, Australia
| | - Krystian A Kozek
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Loren R Vanags
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Devyn W Mitchell
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Brett M Kroncke
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
| | - Jamie I Vandenberg
- Mark Cowley Lidwill Research Program in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; School of Clinical Medicine, UNSW Sydney, Darlinghurst, NSW, Australia.
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10
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Ridley J, Manyweathers S, Tang R, Goetze T, Becker N, Rinke-Weiß I, Kirby R, Obergrussberger A, Rogers M. Development of ASIC1a ligand-gated ion channel drug screening assays across multiple automated patch clamp platforms. Front Mol Neurosci 2022; 15:982689. [PMID: 36340694 PMCID: PMC9629855 DOI: 10.3389/fnmol.2022.982689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/12/2022] [Indexed: 02/05/2023] Open
Abstract
Human acid-sensing ion channels (ASIC) are ligand-gated ionotropic receptors expressed widely in peripheral tissues as well as sensory and central neurons and implicated in detection of inflammation, tissue injury, and hypoxia-induced acidosis. This makes ASIC channels promising targets for drug discovery in oncology, pain and ischemia, and several modulators have progressed into clinical trials. We describe the use of hASIC1a as a case study for the development and validation of low, medium and high throughput automated patch clamp (APC) assays suitable for the screening and mechanistic profiling of new ligands for this important class of ligand-gated ion channel. Initial efforts to expand on previous manual patch work describing an endogenous hASIC1a response in HEK cells were thwarted by low current expression and unusual pharmacology, so subsequent work utilized stable hASIC1a CHO cell lines. Ligand-gated application protocols and screening assays on the Patchliner, QPatch 48, and SyncroPatch 384 were optimized and validated based on pH activation and nM-μM potency of reference antagonists (e.g., Amiloride, Benzamil, Memantine, Mambalgin-3, A-317567, PcTx1). By optimizing single and stacked pipette tip applications available on each APC platform, stable pH-evoked currents during multiple ligand applications enabled cumulative EC50 and IC50 determinations with minimized receptor desensitization. Finally, we successfully demonstrated for the first time on an APC platform the ability to use current clamp to implement the historical technique of input resistance tracking to measure ligand-gated changes in membrane conductance on the Patchliner platform.
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Affiliation(s)
- John Ridley
- Metrion Biosciences Ltd., Cambridge, United Kingdom
| | | | - Raymond Tang
- Metrion Biosciences Ltd., Cambridge, United Kingdom
| | - Tom Goetze
- Nanion Technologies GmbH, Munich, Germany
| | | | | | - Robert Kirby
- Metrion Biosciences Ltd., Cambridge, United Kingdom
| | | | - Marc Rogers
- Metrion Biosciences Ltd., Cambridge, United Kingdom
- *Correspondence: Marc Rogers,
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11
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Obergrussberger A, Rinke-Weiß I, Goetze TA, Rapedius M, Brinkwirth N, Becker N, Rotordam MG, Hutchison L, Madau P, Pau D, Dalrymple D, Braun N, Friis S, Pless SA, Fertig N. The suitability of high throughput automated patch clamp for physiological applications. J Physiol 2021; 600:277-297. [PMID: 34555195 DOI: 10.1113/jp282107] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 09/16/2021] [Indexed: 01/18/2023] Open
Abstract
Although automated patch clamp (APC) devices have been around for many years and have become an integral part of many aspects of drug discovery, high throughput instruments with gigaohm seal data quality are relatively new. Experiments where a large number of compounds are screened against ion channels are ideally suited to high throughput APC, particularly when the amount of compound available is low. Here we evaluate different APC approaches using a variety of ion channels and screening settings. We have performed a screen of 1920 compounds on GluN1/GluN2A NMDA receptors for negative allosteric modulation using both the SyncroPatch 384 and FLIPR. Additionally, we tested the effect of 36 arthropod venoms on NaV 1.9 using a single 384-well plate on the SyncroPatch 384. As an example for mutant screening, a range of acid-sensing ion channel variants were tested and the success rate increased through fluorescence-activated cell sorting (FACS) prior to APC experiments. Gigaohm seal data quality makes the 384-format accessible to recording of primary and stem cell-derived cells on the SyncroPatch 384. We show recordings in voltage and current clamp modes of stem cell-derived cardiomyocytes. In addition, the option of intracellular solution exchange enabled investigations into the effects of intracellular Ca2+ and cAMP on TRPC5 and HCN2 currents, respectively. Together, these data highlight the broad applicability and versatility of APC platforms and also outlines some limitations of the approach. KEY POINTS: High throughput automated patch clamp (APC) can be used for a variety of applications involving ion channels. Lower false positive rates were achieved using automated patch clamp versus a fluorometric imaging plate reader (FLIPR) in a high throughput compound screen against NMDA receptors. Genetic variants and mutations can be screened on a single 384-well plate to reduce variability of experimental parameters. Intracellular solution can be perfused to investigate effects of ions and second messenger systems without the need for excised patches. Primary cells and stem cell-derived cells can be used on high throughput APC with reasonable success rates for cell capture, voltage clamp measurements and action potential recordings in current clamp mode.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Nina Braun
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
| | | | - Stephan A Pless
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
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12
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Yehia A, Wei H. Studying Nicotinic Acetylcholine Receptors Using the IonFlux™ Microfluidic-Based Automated Patch-Clamp System with Continuous Perfusion and Fast Solution Exchange. ACTA ACUST UNITED AC 2021; 88:e73. [PMID: 32068960 DOI: 10.1002/cpph.73] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Automated patch-clamp (APC) systems have become indispensable tools of drug-discovery programs by allowing high-throughput electrophysiology-based screening of ion channel compounds. The recent development and introduction of microfluidics-based APC systems have made it possible to study the interactions of ligand-gated ion channels with pharmacological reagents, such as agonists, antagonists, or positive allosteric modulators (PAMs), with reliable pharmacological results comparable to those of the gold-standard manual patch-clamp technique while maintaining high-throughput capacity. Many ligand-gated ion channels exhibit rapid desensitization upon repetitive introduction of ligands; this loss of channel activity in the absence of pharmacological interaction poses a challenge for developing accurate, precise, and robust assays with high success rate, low run-down, and reliable pharmacological results. Here we present procedures to study nicotinic acetylcholine receptors (nAChRs) with the IonFlux™, an automated patch-clamp system with continuous flow and precise fluidic exchange; these procedures can also be generalized to the study of other ligand-gated ion channels. We present protocols to study agonist, antagonist, and PAM activities on nAChRs, particularly the rapidly desensitizing nAChR α7 receptors. The data demonstrate that the IonFlux™ system is a fast, robust, and reliable platform for the study of nAChRs and other ligand-gated ion channels, generating data that closely mimic those from manual patch-clamp conditions. © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Measuring agonist concentration-dependent response Basic Protocol 2: Measuring antagonist concentration-dependent response Basic Protocol 3: Measuring positive allosteric modulator (PAM) concentration-dependent response Support Protocol 1: Basic IonFlux system operation Support Protocol 2: Plate care and filling Support Protocol 3: Plate preparation for water rinsing Support Protocol 4: Water rinsing of plates Support Protocol 5: Plate priming Support Protocol 6: General assay Support Protocol 7: Editing the compound addition sequence (compound list) Support Protocol 8: Creating compound list for agonist concentration-dependent response Support Protocol 9: Creating compound list for antagonist or PAM concentration-dependent response Support Protocol 10: Defining the different compounds used or compound list Support Protocol 11: Maintenance Support Protocol 12: Data analysis Support Protocol 13: Cell culture.
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Affiliation(s)
- Ali Yehia
- Fluxion Biosciences, Alameda, California
| | - Haiyang Wei
- Eurofins Discovery, Eurofins Panlabs, Inc., St. Charles, Missouri
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13
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Ng CA, Farr J, Young P, Windley MJ, Perry MD, Hill AP, Vandenberg JI. Heterozygous KCNH2 variant phenotyping using Flp-In HEK293 and high-throughput automated patch clamp electrophysiology. Biol Methods Protoc 2021; 6:bpab003. [PMID: 33884304 PMCID: PMC8046900 DOI: 10.1093/biomethods/bpab003] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/10/2021] [Accepted: 03/16/2021] [Indexed: 11/13/2022] Open
Abstract
KCNH2 is one of the 59 medically actionable genes recommended by the American College of Medical Genetics for reporting of incidental findings from clinical genomic sequencing. However, half of the reported KCNH2 variants in the ClinVar database are classified as variants of uncertain significance. In the absence of strong clinical phenotypes, there is a need for functional phenotyping to help decipher the significance of variants identified incidentally. Here, we report detailed methods for assessing the molecular phenotype of any KCNH2 missense variant. The key components of the assay include quick and cost-effective generation of a bi-cistronic vector to co-express Wild-type (WT) and any KCNH2 variant allele, generation of stable Flp-In HEK293 cell lines and high-throughput automated patch clamp electrophysiology analysis of channel function. Stable cell lines take 3–4 weeks to produce and can be generated in bulk, which will then allow up to 30 variants to be phenotyped per week after 48 h of channel expression. This high-throughput functional genomics assay will enable a much more rapid assessment of the extent of loss of function of any KCNH2 variant.
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Affiliation(s)
- Chai-Ann Ng
- Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, New South Wales 2010, Australia.,St Vincent's Clinical School, UNSW Sydney, Darlinghurst, New South Wales 2010, Australia
| | - Jessica Farr
- Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, New South Wales 2010, Australia.,School of Computer Science and Engineering, UNSW Sydney, Kensington, New South Wales 2052, Australia
| | - Paul Young
- Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, New South Wales 2010, Australia
| | - Monique J Windley
- Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, New South Wales 2010, Australia
| | - Matthew D Perry
- Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, New South Wales 2010, Australia.,St Vincent's Clinical School, UNSW Sydney, Darlinghurst, New South Wales 2010, Australia
| | - Adam P Hill
- Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, New South Wales 2010, Australia.,St Vincent's Clinical School, UNSW Sydney, Darlinghurst, New South Wales 2010, Australia
| | - Jamie I Vandenberg
- Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, New South Wales 2010, Australia.,St Vincent's Clinical School, UNSW Sydney, Darlinghurst, New South Wales 2010, Australia
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14
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Ranjan R, Logette E, Marani M, Herzog M, Tâche V, Scantamburlo E, Buchillier V, Markram H. A Kinetic Map of the Homomeric Voltage-Gated Potassium Channel (Kv) Family. Front Cell Neurosci 2019; 13:358. [PMID: 31481875 PMCID: PMC6710402 DOI: 10.3389/fncel.2019.00358] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 07/19/2019] [Indexed: 11/13/2022] Open
Abstract
The voltage-gated potassium (Kv) channels, encoded by 40 genes, repolarize all electrically excitable cells, including plant, cardiac, and neuronal cells. Although these genes were fully sequenced decades ago, a comprehensive kinetic characterization of all Kv channels is still missing, especially near physiological temperature. Here, we present a standardized kinetic map of the 40 homomeric Kv channels systematically characterized at 15, 25, and 35°C. Importantly, the Kv kinetics at 35°C differ significantly from commonly reported kinetics, usually performed at room temperature. We observed voltage-dependent Q10 for all active Kv channels and inherent heterogeneity in kinetics for some of them. Kinetic properties are consistent across different host cell lines and conserved across mouse, rat, and human. All electrophysiology data from all Kv channels are made available through a public website (Channelpedia). This dataset provides a solid foundation for exploring kinetics of heteromeric channels, roles of auxiliary subunits, kinetic modulation, and for building accurate Kv models.
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Affiliation(s)
- Rajnish Ranjan
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Emmanuelle Logette
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland.,Laboratory of Neural Microcircuitry, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Michela Marani
- Laboratory of Neural Microcircuitry, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Mirjia Herzog
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland.,Laboratory of Neural Microcircuitry, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Valérie Tâche
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Enrico Scantamburlo
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Valérie Buchillier
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Henry Markram
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland.,Laboratory of Neural Microcircuitry, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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15
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Billet A, Froux L, Hanrahan JW, Becq F. Development of Automated Patch Clamp Technique to Investigate CFTR Chloride Channel Function. Front Pharmacol 2017; 8:195. [PMID: 28439239 PMCID: PMC5383655 DOI: 10.3389/fphar.2017.00195] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 03/24/2017] [Indexed: 11/13/2022] Open
Abstract
The chloride (Cl-) channel cystic fibrosis transmembrane conductance regulator (CFTR) is defective in cystic fibrosis (CF), and mutation of its encoding gene leads to various defects such as retention of the misfolded protein in the endoplasmic reticulum, reduced stability at the plasma membrane, abnormal channel gating with low open probability, and thermal instability, which leads to inactivation of the channel at physiological temperature. Pharmacotherapy is one major therapeutic approach in the CF field and needs sensible and fast tools to identify promising compounds. The high throughput screening assays available are often fast and sensible techniques but with lack of specificity. Few works used automated patch clamp (APC) for CFTR recording, and none have compared conventional and planar techniques and demonstrated their capabilities for different types of experiments. In this study, we evaluated the use of planar parallel APC technique for pharmacological search of CFTR-trafficking correctors and CFTR function modulators. Using optimized conditions, we recorded both wt- and corrected F508del-CFTR Cl- currents with automated whole-cell patch clamp and compared the data to results obtained with conventional manual whole-cell patch clamp. We found no significant difference in patch clamp parameters such as cell capacitance and series resistance between automated and manual patch clamp. Also, the results showed good similarities of CFTR currents recording between the two methods. We showed that similar stimulation protocols could be used in both manual and automatic techniques allowing precise control of temperature, classic I/V relationship, and monitoring of current stability in time. In conclusion, parallel patch-clamp recording allows rapid and efficient investigation of CFTR currents with a variety of tests available and could be considered as new tool for medium throughput screening in CF pharmacotherapy.
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Affiliation(s)
- Arnaud Billet
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers - ERL7368, Centre National de la Recherche ScientifiquePoitiers, France
| | - Lionel Froux
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers - ERL7368, Centre National de la Recherche ScientifiquePoitiers, France
| | - John W Hanrahan
- Department of Physiology, McGill University, MontrealQC, Canada.,McGill Cystic Fibrosis Translational Research Centre, MontrealQC, Canada.,The Research Institute of the McGill University Health Centre, MontrealQC, Canada
| | - Frederic Becq
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers - ERL7368, Centre National de la Recherche ScientifiquePoitiers, France
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16
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Armstrong LC, Kirsch GE, Fedorov NB, Wu C, Kuryshev YA, Sewell AL, Liu Z, Motter AL, Leggett CS, Orr MS. High-Throughput Patch Clamp Screening in Human α6-Containing Nicotinic Acetylcholine Receptors. SLAS Discov 2017; 22:686-695. [PMID: 28298165 PMCID: PMC5480602 DOI: 10.1177/2472555217696794] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Nicotine, the addictive component of tobacco products, is an agonist at nicotinic acetylcholine receptors (nAChRs) in the brain. The subtypes of nAChR are defined by their α- and β-subunit composition. The α6β2β3 nAChR subtype is expressed in terminals of dopaminergic neurons that project to the nucleus accumbens and striatum and modulate dopamine release in brain regions involved in nicotine addiction. Although subtype-dependent selectivity of nicotine is well documented, subtype-selective profiles of other tobacco product constituents are largely unknown and could be essential for understanding the addiction-related neurological effects of tobacco products. We describe the development and validation of a recombinant cell line expressing human α6/3β2β3V273S nAChR for screening and profiling assays in an automated patch clamp platform (IonWorks Barracuda). The cell line was pharmacologically characterized by subtype-selective and nonselective reference agonists, pore blockers, and competitive antagonists. Agonist and antagonist effects detected by the automated patch clamp approach were comparable to those obtained by conventional electrophysiological assays. A pilot screen of a library of Food and Drug Administration–approved drugs identified compounds, previously not known to modulate nAChRs, which selectively inhibited the α6/3β2β3V273S subtype. These assays provide new tools for screening and subtype-selective profiling of compounds that act at α6β2β3 nicotinic receptors.
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Affiliation(s)
| | | | | | - Caiyun Wu
- 1 Charles River Discovery, Cleveland, OH, USA
| | | | | | - Zhiqi Liu
- 1 Charles River Discovery, Cleveland, OH, USA
| | - Arianne L Motter
- 2 U.S. Food and Drug Administration/Center for Tobacco Products, Silver Spring, MD, USA
| | - Carmine S Leggett
- 2 U.S. Food and Drug Administration/Center for Tobacco Products, Silver Spring, MD, USA
| | - Michael S Orr
- 2 U.S. Food and Drug Administration/Center for Tobacco Products, Silver Spring, MD, USA.,PAREXEL International, Bethesda, MD, USA
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17
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Danker T, Möller C. Early identification of hERG liability in drug discovery programs by automated patch clamp. Front Pharmacol 2014; 5:203. [PMID: 25228880 PMCID: PMC4151236 DOI: 10.3389/fphar.2014.00203] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 08/14/2014] [Indexed: 12/26/2022] Open
Abstract
Blockade of the cardiac ion channel coded by human ether-à-gogo-related gene (hERG) can lead to cardiac arrhythmia, which has become a major concern in drug discovery and development. Automated electrophysiological patch clamp allows assessment of hERG channel effects early in drug development to aid medicinal chemistry programs and has become routine in pharmaceutical companies. However, a number of potential sources of errors in setting up hERG channel assays by automated patch clamp can lead to misinterpretation of data or false effects being reported. This article describes protocols for automated electrophysiology screening of compound effects on the hERG channel current. Protocol details and the translation of criteria known from manual patch clamp experiments to automated patch clamp experiments to achieve good quality data are emphasized. Typical pitfalls and artifacts that may lead to misinterpretation of data are discussed. While this article focuses on hERG channel recordings using the QPatch (Sophion A/S, Copenhagen, Denmark) technology, many of the assay and protocol details given in this article can be transferred for setting up different ion channel assays by automated patch clamp and are similar on other planar patch clamp platforms.
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Affiliation(s)
| | - Clemens Möller
- Life Sciences Faculty, Albstadt-Sigmaringen University of Applied Sciences Sigmaringen, Germany
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18
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Abstract
INTRODUCTION From a drug discovery point of view, ion channels are very interesting and challenging targets. Over the past decade, great efforts have been made in developing platforms for patch clamp-based high-quality screening of ion channels in discovering new drug candidates as well for evaluating their safety profiles. Indeed, the automated patch clamp (APC) has recently reached the data throughput requirements of high-throughput screening (HTS) allowing for new screening strategies with ion channel active compounds. AREAS COVERED This editorial article comments on the past and present developments of APC-based drug screening. Furthermore, it also looks at the implications of APC technology meeting HTS-standards as well as its use in compound safety evaluation. EXPERT OPINION In the imminent future, we will see a paradigm shift in ion channel drug screening toward using APC-based platforms for primary drug library screens. This way, the redundancy of the drug discovery process and the risk of false-negatives could be drastically reduced. Furthermore, cardiac safety can be addressed early, avoiding late-phase withdrawals with promising drug candidates. It is our firm belief that APC-based ion channel HTS will facilitate the discovery of candidates, which otherwise would have not been found, and shorten the drug development cycle, saving time and cost.
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Affiliation(s)
- Cecilia Farre
- Nanion Technologies , Gabrirelenstrasse 9, 80636 München , Germany
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19
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Zicha S, Radresa O, Laplante P, Morton M, Jones K, Main M, Trivedi S, Julien RP, Griffin A, Labrecque J, Ahmad S, Brown W. Novel methodology to identify TRPV1 antagonists independent of capsaicin activation. ACTA ACUST UNITED AC 2012; 18:544-55. [PMID: 23264449 DOI: 10.1177/1087057112470563] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
TRPV1 was originally characterized as an integrator of various noxious stimuli such as capsaicin, heat, and protons. TRPV1-null mice exhibit a deficiency in sensing noxious heat stimuli, suggesting that TRPV1 is one of the main heat sensors on nociceptive primary afferent neurons and a candidate target for heat hypersensitivity in chronic pain. Several different potent and selective TRPV1 antagonists have been developed by more than 50 companies since the characterization of the receptor in 1997. A consequence of this competitive interest is the crowding of patentable chemical space, because very similar in vitro screening assays are used. To circumvent this issue and to expand our understanding of TRPV1 biology, we sought to take advantage of recent advancements in automated patch-clamp technology to design a novel screening cascade. This SAR-driving assay identified novel modulators that blocked the depolarization-induced activation of outwardly-rectifying TRPV1 currents independent of agonist stimulation, and we correlated the pharmacology to three other innovative assays for higher-throughput screening. Ultimately, we have identified a screening paradigm that would have good predictive value for future TRPV1 drug discovery projects and novel chemical space with a higher probability of gaining intellectual property coverage.
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Polonchuk L. Toward a New Gold Standard for Early Safety: Automated Temperature-Controlled hERG Test on the PatchLiner. Front Pharmacol 2012; 3:3. [PMID: 22303293 PMCID: PMC3266667 DOI: 10.3389/fphar.2012.00003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 01/06/2012] [Indexed: 11/13/2022] Open
Abstract
The Patchliner® temperature-controlled automated patch clamp system was evaluated for testing drug effects on potassium currents through human ether-à-go-go related gene (hERG) channels expressed in Chinese hamster ovary cells at 35-37°C. IC(50) values for a set of reference drugs were compared with those obtained using the conventional voltage clamp technique. The results showed good correlation between the data obtained using automated and conventional electrophysiology. Based on these results, the Patchliner(®) represents an innovative automated electrophysiology platform for conducting the hERG assay that substantially increases throughput and has the advantage of operating at physiological temperature. It allows fast, accurate, and direct assessment of channel function to identify potential proarrhythmic side effects and sets a new standard in ion channel research for drug safety testing.
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Affiliation(s)
- Liudmila Polonchuk
- Non-Clinical Safety, Pharma Research, F. Hoffmann-La Roche Ltd. Basel, Switzerland
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Stoelzle S, Obergrussberger A, Brüggemann A, Haarmann C, George M, Kettenhofen R, Fertig N. State-of-the-Art Automated Patch Clamp Devices: Heat Activation, Action Potentials, and High Throughput in Ion Channel Screening. Front Pharmacol 2011; 2:76. [PMID: 22131976 PMCID: PMC3223389 DOI: 10.3389/fphar.2011.00076] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 11/07/2011] [Indexed: 12/19/2022] Open
Abstract
Ion channels are essential in a wide range of cellular functions and their malfunction underlies many disease states making them important targets in drug discovery. The availability of standardized cell lines expressing ion channels of interest lead to the development of diverse automated patch clamp (APC) systems with high-throughput capabilities. These systems are now available for drug screening, but there are limitations in the application range. However, further development of existing devices and introduction of new systems widen the range of possible experiments and increase throughput. The addition of well controlled and fast solution exchange, temperature control and the availability of the current clamp mode are required to analyze standard cell lines and excitable cells such as stem cell-derived cardiomyocytes in a more physiologically relevant environment. Here we describe two systems with different areas of applications that meet the needs of drug discovery researchers and basic researchers alike. The here utilized medium throughput APC device is a planar patch clamp system capable of recording up to eight cells simultaneously. Features such as temperature control and recordings in the current clamp mode are described here. Standard cell lines and excitable cells such as stem cell-derived cardiomyocytes have been used in the voltage clamp and current clamp modes with the view to finding new drug candidates and safety testing methods in a more physiologically relevant environment. The high-throughput system used here is a planar patch clamp screening platform capable of recording from 96 cells in parallel and offers a throughput of 5000 data points per day. Full dose response curves can be acquired from individual cells reducing the cost per data point. The data provided reveals the suitability and relevance of both APC platforms for drug discovery, ion channel research, and safety testing.
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