1
|
Emigh Cortez AM, DeMarco KR, Furutani K, Bekker S, Sack JT, Wulff H, Clancy CE, Vorobyov I, Yarov-Yarovoy V. Structural modeling of hERG channel-drug interactions using Rosetta. Front Pharmacol 2023; 14:1244166. [PMID: 38035013 PMCID: PMC10682396 DOI: 10.3389/fphar.2023.1244166] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 06/22/2023] [Accepted: 10/23/2023] [Indexed: 12/02/2023] Open
Abstract
The human ether-a-go-go-related gene (hERG) not only encodes a potassium-selective voltage-gated ion channel essential for normal electrical activity in the heart but is also a major drug anti-target. Genetic hERG mutations and blockage of the channel pore by drugs can cause long QT syndrome, which predisposes individuals to potentially deadly arrhythmias. However, not all hERG-blocking drugs are proarrhythmic, and their differential affinities to discrete channel conformational states have been suggested to contribute to arrhythmogenicity. We used Rosetta electron density refinement and homology modeling to build structural models of open-state hERG channel wild-type and mutant variants (Y652A, F656A, and Y652A/F656 A) and a closed-state wild-type channel based on cryo-electron microscopy structures of hERG and EAG1 channels. These models were used as protein targets for molecular docking of charged and neutral forms of amiodarone, nifekalant, dofetilide, d/l-sotalol, flecainide, and moxifloxacin. We selected these drugs based on their different arrhythmogenic potentials and abilities to facilitate hERG current. Our docking studies and clustering provided atomistic structural insights into state-dependent drug-channel interactions that play a key role in differentiating safe and harmful hERG blockers and can explain hERG channel facilitation through drug interactions with its open-state hydrophobic pockets.
Collapse
Affiliation(s)
- Aiyana M. Emigh Cortez
- Biophysics Graduate Group, University of California, Davis, Davis, CA, United States
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Kevin R. DeMarco
- Biophysics Graduate Group, University of California, Davis, Davis, CA, United States
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Kazuharu Furutani
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Pharmacology, Tokushima Bunri University, Tokushima, Japan
| | - Slava Bekker
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- American River College, Sacramento, CA, United States
| | - Jon T. Sack
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA, United States
| | - Heike Wulff
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Colleen E. Clancy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
- Center for Precision Medicine and Data Sciences, University of California, Davis, Davis, CA, United States
| | - Igor Vorobyov
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
- Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA, United States
| |
Collapse
|
2
|
Furutani K. Facilitation of hERG Activation by Its Blocker: A Mechanism to Reduce Drug-Induced Proarrhythmic Risk. Int J Mol Sci 2023; 24:16261. [PMID: 38003453 PMCID: PMC10671758 DOI: 10.3390/ijms242216261] [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: 10/24/2023] [Revised: 11/08/2023] [Accepted: 11/12/2023] [Indexed: 11/26/2023] Open
Abstract
Modulation of the human Ether-à-go-go-Related Gene (hERG) channel, a crucial voltage-gated potassium channel in the repolarization of action potentials in ventricular myocytes of the heart, has significant implications on cardiac electrophysiology and can be either antiarrhythmic or proarrhythmic. For example, hERG channel blockade is a leading cause of long QT syndrome and potentially life-threatening arrhythmias, such as torsades de pointes. Conversely, hERG channel blockade is the mechanism of action of Class III antiarrhythmic agents in terminating ventricular tachycardia and fibrillation. In recent years, it has been recognized that less proarrhythmic hERG blockers with clinical potential or Class III antiarrhythmic agents exhibit, in addition to their hERG-blocking activity, a second action that facilitates the voltage-dependent activation of the hERG channel. This facilitation is believed to reduce the proarrhythmic potential by supporting the final repolarizing of action potentials. This review covers the pharmacological characteristics of hERG blockers/facilitators, the molecular mechanisms underlying facilitation, and their clinical significance, as well as unresolved issues and requirements for research in the fields of ion channel pharmacology and drug-induced arrhythmias.
Collapse
Affiliation(s)
- Kazuharu Furutani
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Nishihama-Boji, Yamashiro-cho, Tokushima 770-8514, Japan
| |
Collapse
|
3
|
Nemati M, Hosseinzadeh Z, Nemati F, Ebrahimi B. Impact of antipsychotics and antidepressants drugs on long QT syndrome induction related to hERG channel dysfunction: A systematic review. Biochem Biophys Res Commun 2023; 681:90-96. [PMID: 37774574 DOI: 10.1016/j.bbrc.2023.09.043] [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: 07/15/2023] [Revised: 09/03/2023] [Accepted: 09/18/2023] [Indexed: 10/01/2023]
Abstract
PURPOSE QT prolongation is one of the main unwanted cardiac effects caused by drugs, such as anti-psychotics and anti-depressants, inducing mainly via hERG channel dysfunction. The precise and underlying mechanism of adverse effects on hERG channel are still indecisive, but these effects limit their use in patients with cardiac risk factors. The aim of this review was studying mechanism of Long-term QT syndrome induction via hERG channel dysfunction by these Drugs. METHOD Search was performed in PubMed, and Scopus. All human, animals, and cell lines studies, English and full text publications were included. Among 1280 papers, 23 studies were eligible for more assessments. Quality of studies cheeked by two researchers independently. KEY FINDING most of studies were done on anti-psychotic drugs, especially typical class. Most used investigated method to long-term QT induction was patch clamp. SIGNIFICANCE results suggests in susceptible cases with heart risk factors, these drugs should be taken with caution and monitored.
Collapse
Affiliation(s)
- Marzieh Nemati
- Endocrinology and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Zahra Hosseinzadeh
- Endocrinology and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fatemeh Nemati
- School of Dentistry, Shiraz University of Medical Science, Shiraz, Iran
| | - Bahareh Ebrahimi
- Geriatric Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| |
Collapse
|
4
|
Wang X, Feng Y, Liu S, Liu J, Pan S, Wei L, Ma Y, Liu Z, Xing Y, Wang J, Cui Q, Zhang Y, Wang T, Cai C. Hydroxychloroquine Attenuates hERG Channel by Promoting the Membrane Channel Degradation: Computational Simulation and Experimental Evidence for QT-Interval Prolongation with Hydroxychloroquine Treatment. Cardiology 2023; 148:310-323. [PMID: 37231805 DOI: 10.1159/000531132] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 05/11/2023] [Indexed: 05/27/2023]
Abstract
INTRODUCTION The coronavirus disease 2019 (COVID-19) pandemic has led to millions of confirmed cases and deaths worldwide and has no approved therapy. Currently, more than 700 drugs are tested in the COVID-19 clinical trials, and full evaluation of their cardiotoxicity risks is in high demand. METHODS We mainly focused on hydroxychloroquine (HCQ), one of the most concerned drugs for COVID-19 therapy, and investigated the effects and underlying mechanisms of HCQ on hERG channel via molecular docking simulations. We further applied the HEK293 cell line stably expressing hERG-wild-type channel (hERG-HEK) and HEK293 cells transiently expressing hERG-p.Y652A or hERG-p.F656A mutants to validate our predictions. Western blot analysis was used to determine the hERG channel, and the whole-cell patch clamp was utilized to record hERG current (IhERG). RESULTS HCQ reduced the mature hERG protein in a time- and concentration-dependent manner. Correspondingly, chronic and acute treatment of HCQ decreased the hERG current. Treatment with brefeldin A (BFA) and HCQ combination reduced hERG protein to a greater extent than BFA alone. Moreover, disruption of the typical hERG binding site (hERG-p.Y652A or hERG-p.F656A) rescued HCQ-mediated hERG protein and IhERG reduction. CONCLUSION HCQ can reduce the mature hERG channel expression and IhERG via enhancing channel degradation. The QT prolongation effect of HCQ is mediated by typical hERG binding sites involving residues Tyr652 and Phe656.
Collapse
Affiliation(s)
- Xiqiang Wang
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Yunfei Feng
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Senmiao Liu
- Division of Data Intelligence, Department of Computer Science, Key Laboratory of Intelligent Manufacturing Technology of Ministry of Education, College of Engineering, Shantou University, Shantou, China
| | - Jing Liu
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Shuo Pan
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Linyan Wei
- Department of General Practice, The Second Affiliated Hospital Zhejiang University School of Medicine, Hangzhou, China
| | - Yanpeng Ma
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Zhongwei Liu
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Yujie Xing
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Junkui Wang
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Qianwei Cui
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Yong Zhang
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Tingzhong Wang
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Chuipu Cai
- Division of Data Intelligence, Department of Computer Science, Key Laboratory of Intelligent Manufacturing Technology of Ministry of Education, College of Engineering, Shantou University, Shantou, China
| |
Collapse
|
5
|
Ma J, Niklewski PJ, Wang HS. Acute exposure to low-dose bisphenol A delays cardiac repolarization in female canine heart - Implication for proarrhythmic toxicity in large animals. Food Chem Toxicol 2023; 172:113589. [PMID: 36584932 PMCID: PMC9852101 DOI: 10.1016/j.fct.2022.113589] [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: 09/12/2022] [Revised: 12/12/2022] [Accepted: 12/24/2022] [Indexed: 12/29/2022]
Abstract
Bisphenol A (BPA) is a common environmental chemical with a range of potential adverse health effects. The impact of environmentally-relevant low dose of BPA on the electrical properties of the hearts of large animals (e.g., dog, human) is poorly defined. Perturbation of cardiac electrical properties is a key arrhythmogenic mechanism. In particular, delay of ventricular repolarization and prolongation of the QT interval of the electrocardiogram is a marker for the risk of malignant arrhythmias. We examined the acute effect of 10-9 M BPA on the electrical properties of female canine ventricular myocytes and tissues. BPA rapidly delayed action potential repolarization and prolonged action potential duration (APD). The dose response curve of BPA on APD was nonmonotonic. BPA rapidly inhibited the IKr K+ current and ICaL Ca2+ current. Computational modeling indicated that the effect of BPA on APD can be accounted for by its suppression of IKr. At the tissue level, BPA acutely prolonged the QT interval in 4 left ventricular wedges. ERβ signaling contributed to the acute effects of BPA on ventricular repolarization. Our results demonstrate that BPA has QT prolongation liability in female canine hearts. These findings have implication for the potential proarrhythmic cardiac toxicity of BPA in large animals.
Collapse
Affiliation(s)
- Jianyong Ma
- Department of Pharmacology and Systems Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH, USA
| | - Paul J Niklewski
- Department of Pharmacology and Systems Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH, USA
| | - Hong-Sheng Wang
- Department of Pharmacology and Systems Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH, USA.
| |
Collapse
|
6
|
Zünkler BJ, Wos-Maganga M, Bohnet S, Kleinau A, Manns D, Chatterjee S. Intracellular Binding of Terfenadine Competes with Its Access to Pancreatic ß-cell ATP-Sensitive K + Channels and Human ether-à-go-go-Related Gene Channels. J Membr Biol 2023; 256:63-77. [PMID: 35763054 PMCID: PMC9884252 DOI: 10.1007/s00232-022-00252-y] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 06/02/2022] [Indexed: 02/07/2023]
Abstract
Most blockers of both hERG (human ether-à-go-go-related gene) channels and pancreatic ß-cell ATP-sensitive K+ (KATP) channels access their binding sites from the cytoplasmic side of the plasma membrane. It is unknown whether binding to intracellular components competes with binding of these substances to K+ channels. The whole-cell configuration of the patch-clamp technique, a laser-scanning confocal microscope, and fluorescence correlation spectroscopy (FCS) were used to study hERG channels expressed in HEK (human embryonic kidney) 293 cells and KATP channels from the clonal insulinoma cell line RINm5F. When applied via the pipette solution in the whole-cell configuration, terfenadine blocked both hERG and KATP currents with much lower potency than after application via the bath solution, which was not due to P-glycoprotein-mediated efflux of terfenadine. Such a difference was not observed with dofetilide and tolbutamide. 37-68% of hERG/EGFP (enhanced green-fluorescent protein) fusion proteins expressed in HEK 293 cells were slowly diffusible as determined by laser-scanning microscopy in the whole-cell configuration and by FCS in intact cells. Bath application of a green-fluorescent sulphonylurea derivative (Bodipy-glibenclamide) induced a diffuse fluorescence in the cytosol of RINm5F cells under whole-cell patch-clamp conditions. These observations demonstrate the presence of intracellular binding sites for hERG and KATP channel blockers not dialyzable by the patch-pipette solution. Intracellular binding of terfenadine was not influenced by a mutated hERG (Y652A) channel. In conclusion, substances with high lipophilicity are not freely diffusible inside the cell but steep concentration gradients might exist within the cell and in the sub-membrane space.
Collapse
Affiliation(s)
- Bernd J Zünkler
- Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany.
- Institute of Pharmacology, Toxicology and Clinical Pharmacy, Technische Universität Braunschweig, Mendelssohnstr. 1, 38106, Braunschweig, Germany.
| | - Maria Wos-Maganga
- Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Stefanie Bohnet
- Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Anne Kleinau
- Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Detlef Manns
- Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Shivani Chatterjee
- Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| |
Collapse
|
7
|
Morishita H, Perera LMB, Zhang X, Mizoi K, Ito MA, Yano K, Ogihara T. P-Glycoprotein-Mediated Pharmacokinetic Interactions Increase Pimozide hERG Channel Inhibition. J Pharm Sci 2022; 111:3411-3416. [PMID: 36181876 DOI: 10.1016/j.xphs.2022.09.025] [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: 05/17/2022] [Revised: 09/23/2022] [Accepted: 09/23/2022] [Indexed: 01/05/2023]
Abstract
Pimozide, an antipsychotic drug, is a potent inhibitor of the hERG channel. A case of death due to cardiac arrest has been reported in a boy who received pimozide together with sertraline and aripiprazole. In this study, we focused on drug-drug interactions and investigated the relationships between transporter-mediated intracellular accumulation and the hERG inhibitory effect of pimozide. The accumulation of pimozide in cardiomyocyte-derived AC16 cells was significantly increased by sertraline and aripiprazole, which are thought to have a P-glycoprotein (P-gp) inhibitory effect, and under P-gp siRNA conditions. These results suggest P-gp inhibition increases pimozide accumulation in AC16 cells. We introduced the hERG plasmid into AC16 cells and investigated the concentration-dependent hERG inhibitory effect of pimozide from within AC16 cells. Addition of 10 nM or more pimozide significantly inhibited the hERG current with concentration dependence. These results indicate P-gp-mediated pharmacokinetic interaction increases pimozide accumulation in AC16 cells, and the subsequent elevated pimozide levels within the cells may result in an increased risk of hERG channel inhibition. Our present study calls attention to the risks associated with the combined use of cardiotoxic P-gp substrate(s) and P-gp inhibitory medicines.
Collapse
Affiliation(s)
- Hiroki Morishita
- Department of Pharmacy, Saiseikai Maebashi Hospital, 564-1 Kamishinden-machi, Maebashi-shi, Gunma 371-0821, Japan; Laboratory of Clinical Pharmacokinetics, Graduate School of Pharmaceutical Sciences, Takasaki University of Health and Welfare, 60 Nakaorui-machi, Takasaki-shi, Gunma 370-0033, Japan.
| | - Liyanage Manosika Buddhini Perera
- Laboratory of Biopharmaceutics, Faculty of Pharmacy, Takasaki University of Health and Welfare, 60 Nakaorui-machi, Takasaki-shi, Gunma 370-0033, Japan
| | - Xieyi Zhang
- Laboratory of Biopharmaceutics, Faculty of Pharmacy, Takasaki University of Health and Welfare, 60 Nakaorui-machi, Takasaki-shi, Gunma 370-0033, Japan
| | - Kenta Mizoi
- Laboratory of Biopharmaceutics, Faculty of Pharmacy, Takasaki University of Health and Welfare, 60 Nakaorui-machi, Takasaki-shi, Gunma 370-0033, Japan
| | - Masa-Aki Ito
- Laboratory of Pharmacology, Faculty of Pharmacy, Takasaki University of Health and Welfare, 60 Nakaorui-machi, Takasaki-shi, Gunma 370-0033, Japan
| | - Kentaro Yano
- Laboratory of Drug Metabolism and Pharmacokinetics, Yokohama University of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama, Kanagawa 245-0066, Japan
| | - Takuo Ogihara
- Laboratory of Clinical Pharmacokinetics, Graduate School of Pharmaceutical Sciences, Takasaki University of Health and Welfare, 60 Nakaorui-machi, Takasaki-shi, Gunma 370-0033, Japan; Laboratory of Biopharmaceutics, Faculty of Pharmacy, Takasaki University of Health and Welfare, 60 Nakaorui-machi, Takasaki-shi, Gunma 370-0033, Japan
| |
Collapse
|
8
|
Maly J, Emigh AM, DeMarco KR, Furutani K, Sack JT, Clancy CE, Vorobyov I, Yarov-Yarovoy V. Structural modeling of the hERG potassium channel and associated drug interactions. Front Pharmacol 2022; 13:966463. [PMID: 36188564 PMCID: PMC9523588 DOI: 10.3389/fphar.2022.966463] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [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: 06/11/2022] [Accepted: 08/25/2022] [Indexed: 11/13/2022] Open
Abstract
The voltage-gated potassium channel, KV11.1, encoded by the human Ether-à-go-go-Related Gene (hERG), is expressed in cardiac myocytes, where it is crucial for the membrane repolarization of the action potential. Gating of the hERG channel is characterized by rapid, voltage-dependent, C-type inactivation, which blocks ion conduction and is suggested to involve constriction of the selectivity filter. Mutations S620T and S641A/T within the selectivity filter region of hERG have been shown to alter the voltage dependence of channel inactivation. Because hERG channel blockade is implicated in drug-induced arrhythmias associated with both the open and inactivated states, we used Rosetta to simulate the effects of hERG S620T and S641A/T mutations to elucidate conformational changes associated with hERG channel inactivation and differences in drug binding between the two states. Rosetta modeling of the S641A fast-inactivating mutation revealed a lateral shift of the F627 side chain in the selectivity filter into the central channel axis along the ion conduction pathway and the formation of four lateral fenestrations in the pore. Rosetta modeling of the non-inactivating mutations S620T and S641T suggested a potential molecular mechanism preventing F627 side chain from shifting into the ion conduction pathway during the proposed inactivation process. Furthermore, we used Rosetta docking to explore the binding mechanism of highly selective and potent hERG blockers - dofetilide, terfenadine, and E4031. Our structural modeling correlates well with much, but not all, existing experimental evidence involving interactions of hERG blockers with key residues in hERG pore and reveals potential molecular mechanisms of ligand interactions with hERG in an inactivated state.
Collapse
Affiliation(s)
- Jan Maly
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States,Biophysics Graduate Group, University of California, Davis, Davis, CA, United States
| | - Aiyana M. Emigh
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States,Biophysics Graduate Group, University of California, Davis, Davis, CA, United States
| | - Kevin R. DeMarco
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States,Biophysics Graduate Group, University of California, Davis, Davis, CA, United States
| | - Kazuharu Furutani
- Department of Pharmacology, Tokushima Bunri University, Tokushima, Japan
| | - Jon T. Sack
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States
| | - Colleen E. Clancy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States,Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Igor Vorobyov
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States,Department of Pharmacology, University of California, Davis, Davis, CA, United States,*Correspondence: Igor Vorobyov, ; Vladimir Yarov-Yarovoy,
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA, United States,*Correspondence: Igor Vorobyov, ; Vladimir Yarov-Yarovoy,
| |
Collapse
|
9
|
Goel H, Yu W, MacKerell AD. hERG Blockade Prediction by Combining Site Identification by Ligand Competitive Saturation and Physicochemical Properties. Chemistry (Basel) 2022; 4:630-646. [PMID: 36712295 PMCID: PMC9881610 DOI: 10.3390/chemistry4030045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Human ether-a-go-go-related gene (hERG) potassium channel is well-known contributor to drug-induced cardiotoxicity and therefore an extremely important target when performing safety assessments of drug candidates. Ligand-based approaches in connection with quantitative structure active relationships (QSAR) analyses have been developed to predict hERG toxicity. Availability of the recent published cryogenic electron microscopy (cryo-EM) structure for the hERG channel opened the prospect for using structure-based simulation and docking approaches for hERG drug liability predictions. In recent time, the idea of combining structure- and ligand-based approaches for modeling hERG drug liability has gained momentum offering improvements in predictability when compared to ligand-based QSAR practices alone. The present article demonstrates uniting the structure-based SILCS (site-identification by ligand competitive saturation) approach in conjunction with physicochemical properties to develop predictive models for hERG blockade. This combination leads to improved model predictability based on Pearson's R and percent correct (represents rank-ordering of ligands) metric for different validation sets of hERG blockers involving diverse chemical scaffold and wide range of pIC50 values. The inclusion of the SILCS structure-based approach allows determination of the hERG region to which compounds bind and the contribution of different chemical moieties in the compounds to blockade, thereby facilitating the rational ligand design to minimize hERG liability.
Collapse
Affiliation(s)
- Himanshu Goel
- Computer Aided Drug Design Center, Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn St. Baltimore, MD 21201, United States
| | - Wenbo Yu
- Computer Aided Drug Design Center, Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn St. Baltimore, MD 21201, United States
| | - Alexander D. MacKerell
- Computer Aided Drug Design Center, Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 Penn St. Baltimore, MD 21201, United States
| |
Collapse
|
10
|
Parker JA, Fung ES, Trejo-Martin A, Liang L, Gibbs K, Bandara S, Chen S, Sandhu R, Bercu J, Maier A. The utility of hERG channel inhibition data in the derivation of occupational exposure limits. Regul Toxicol Pharmacol 2022; 134:105224. [PMID: 35817210 DOI: 10.1016/j.yrtph.2022.105224] [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: 03/07/2022] [Revised: 05/20/2022] [Accepted: 07/06/2022] [Indexed: 11/19/2022]
Abstract
Inhibition of the human ether-à-go-go (hERG) channel may lead to QT prolongation and fatal arrhythmia. While pharmaceutical drug candidates that exhibit potent hERG channel inhibition often fail early in development, many drugs with both cardiac and non-cardiac indications proceed to market. In this study, the relationship between in vitro hERG channel inhibition and published occupational exposure limit (OEL) was evaluated. A total of 23 cardiac drugs and 44 drugs with non-cardiac indications with published hERG channel IC50 and published OELs were identified. There was an apparent relationship between hERG IC50 potency and the OEL for cardiac and non-cardiac drugs. Twenty cardiac and non-cardiac drugs were identified that had a potent hERG IC50 (≤25 μM) and a contrastingly large OEL value (≥100 μg/m3). OELs or hazard banding corresponding to ≤100 μg/m3 should be sufficiently protective of effects following occupational exposure to the majority of APIs with hERG IC50 values ≤ 100 μM. It is important to consider hERG IC50 values and possible cardiac effects when deriving OEL values for drugs, regardless of indication. These considerations may be particularly important early in the drug development process for establishing exposure control bands for drugs that do not yet have full clinical safety data.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Joel Bercu
- Gilead Sciences, Inc., Nonclinical Safety and Pathobiology, Foster City, CA, USA
| | | |
Collapse
|
11
|
Champéroux P, Fares R, Bastogne T, Richard S, Le Guennec JY, Thireau J. Contribution of hemodynamic side effects and associated autonomic reflexes to ventricular arrhythmias triggering by torsadogenic hERG blocking drugs. Br J Pharmacol 2022; 179:4549-4562. [PMID: 35751378 PMCID: PMC9543494 DOI: 10.1111/bph.15905] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 05/16/2022] [Accepted: 06/01/2022] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSES Several hERG blocking drugs known for their propensity to trigger Torsades de Pointes (TdP) were reported to induce a sympatho-vagal coactivation and to enhance High Frequency heart rate (HFHR) and QT oscillations (HFQT) from telemetric data. The present work aims to characterise the underlying mechanism(s) leading to these autonomic changes. EXPERIMENTAL APPROACH Effects of 15 torsadogenic hERG blocking drugs (astemizole, chlorpromazine, cisapride, droperidol, ibutilide, dofetilide, haloperidol, moxifloxacin, pimozide, quinidine, risperidone, sotalol, sertindole, terfenadine, thioridazine) were assessed by telemetry in beagle dogs. Hemodynamic effects on diastolic and systolic arterial pressure were analysed from the first doses causing QTc prolongation and/or HFQT oscillations enhancement. Autonomic control changes were analysed with the High Frequency Autonomic Modulation (HFAM) model. KEY RESULTS Except moxifloxacin and quinidine, all torsadogenic hERG blockers induced parasympathetic activation or sympatho-vagal coactivation combined with enhancement of HFQT oscillations. These autonomic effects result from reflex compensatory mechanisms in response to mild hemodynamic side effects. These hemodynamic mechanisms were characterised by transient HR acceleration during HF oscillations. A phenomenon of concealed QT prolongation was unmasked for several torsadogenic hERG blockers under β-adrenoceptors blockade by atenolol. Resulting enhancement of HFQT oscillations was shown to contribute directly to triggering of dofetilide induced ventricular arrhythmias. CONCLUSIONS AND IMPLICATIONS This work supports for the first time a contribution of hemodynamic side properties to ventricular arrhythmias triggering by torsadogenic hERG blocking drugs. These hemodynamic side effects may constitute a second component of their arrhythmic profile acting as a trigger alongside their intrinsic arrhythmogenic electrophysiological properties.
Collapse
Affiliation(s)
| | - Raafat Fares
- ERBC France, Chemin de Montifault, Baugy, France
| | - Thierry Bastogne
- CRAN CNRS UMR 7039, Université de Lorraine, Vandœuvre-lès-Nancy, France
| | | | - Jean-Yves Le Guennec
- Laboratoire PHYMEDEXP, Université de Montpellier, INSERM, CNRS, Montpellier cedex, France
| | - Jérôme Thireau
- Laboratoire PHYMEDEXP, Université de Montpellier, INSERM, CNRS, Montpellier cedex, France
| |
Collapse
|
12
|
Yoon KS, Cha HJ, Choi SO, Lee JM. 2-((2-(4-Iodo-2,5-dimethoxyphenyl)ethylamino)methyl)phenol (25I-NBOH) and 2-(((2-(4-chloro-2,5-dimethoxyphenyl)ethyl)amino)methyl)phenol (25C-NBOH) induce adverse effects on the cardiovascular system. Toxicol Lett 2022; 355:160-169. [PMID: 34843874 DOI: 10.1016/j.toxlet.2021.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 08/04/2021] [Revised: 10/30/2021] [Accepted: 11/24/2021] [Indexed: 12/14/2022]
Abstract
Two new psychoactive substances (NPSs) classified as phenethylamines, namely 2-((2-(4-Iodo-2,5-dimethoxyphenyl)ethylamino)methyl)phenol (25I-NBOH) and 2-(((2-(4-chloro-2,5-dimethoxyphenyl)ethyl)amino)methyl)phenol (25C-NBOH), are being abused by people seeking recreational hallucinogens. These NPSs may cause serious health problems as their adverse effects are not known in most cases. Therefore, in the present study, we evaluated the cardiotoxicity of 25I-NBOH and 25C-NBOH using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, rat electrocardiography (ECG), Langendorff test, and human ether-a-go-go-related gene (hERG) assay. Furthermore, we analyzed the expression levels of p21 CDC42/RAC1-activated kinase 1 (PAK1), which is known to play various roles in the cardiovascular system. In the MTT assay, treatment with 25I-NBOH or 25C-NBOH dramatically decreased viability of H9c2 cardiomyocytes. Meanwhile, these two compounds significantly increased QT intervals and RR intervals in the rat ECG measurement. 25I-NBOH down-regulated the PAK1 protein expression in rat primary cardiomyocytes as well as H9c2 cells. However, 25C-NBOH had no effect on the PAK1 expression in H9c2 cells. In an in-depth study, 25I-NBOH inhibited potassium channels in the hERG assay, but in ex vivo test, the substance did not affect the left ventricular developed pressure (LVDP) and heart rate of the isolated rat hearts. Taken together, these results suggest that both 25I-NBOH and 25C-NBOH may have adverse cardiovascular effect. Further investigation would be needed to determine which factors mainly influence the relationship between PAK1 expression and cardiotoxicity.
Collapse
Affiliation(s)
- Kyung Sik Yoon
- National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Hye Jin Cha
- National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Sun Ok Choi
- National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Jin-Moo Lee
- National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| |
Collapse
|
13
|
Krantz MJ, Palmer RB, Haigney MCP. Cardiovascular Complications of Opioid Use: JACC State-of-the-Art Review. J Am Coll Cardiol 2021; 77:205-23. [PMID: 33446314 DOI: 10.1016/j.jacc.2020.11.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 12/29/2022]
Abstract
Opioids are the most potent of all analgesics. Although traditionally used solely for acute self-limited conditions and palliation of severe cancer-associated pain, a movement to promote subjective pain (scale, 0 to 10) to the status of a "fifth vital sign" bolstered widespread prescribing for chronic, noncancer pain. This, coupled with rising misuse, initiated a surge in unintentional deaths, increased drug-associated acute coronary syndrome, and endocarditis. In response, the American College of Cardiology issued a call to action for cardiovascular care teams. Opioid toxicity is primarily mediated via potent μ-receptor agonism resulting in ventilatory depression. However, both overdose and opioid withdrawal can trigger major adverse cardiovascular events resulting from hemodynamic, vascular, and proarrhythmic/electrophysiological consequences. Although natural opioid analogues are devoid of repolarization effects, synthetic agents may be proarrhythmic. This perspective explores cardiovascular consequences of opioids, the contributions of off-target electrophysiologic properties to mortality, and provides practical safety recommendations.
Collapse
|
14
|
Jenewein T, Kanner SA, Bauer D, Hertel B, Colecraft HM, Moroni A, Thiel G, Kauferstein S. The mutation L69P in the PAS domain of the hERG potassium channel results in LQTS by trafficking deficiency. Channels (Austin) 2021; 14:163-174. [PMID: 32253972 PMCID: PMC7188350 DOI: 10.1080/19336950.2020.1751522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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] [Indexed: 02/06/2023] Open
Abstract
The congenital long QT syndrome (LQTS) is a cardiac disorder characterized by a prolonged QT interval on the electrocardiogram and an increased susceptibility to ventricular arrhythmias and sudden cardiac death. A frequent cause for LQTS is mutations in the KCNH2 gene (also known as the human ether-a-go-go-related gene or hERG), which reduce or modulate the potassium current IKr and hence alter cardiac repolarization. In a patient with a clinically diagnosed LQTS, we identified the mutation L69P in the N-terminal PAS (Per-Arnt-Sim) domain of hERG. Functional expression in HEK293 cells shows that a homotetrameric hERG channel reconstituted with only mutant subunits exhibits a drastically reduced surface expression of the channel protein thus leading to a diminished hERG current. Unlike many other mutations in the hERG-PAS domain the negative impact of the L69P substitution cannot be rescued by facilitated protein folding at a lower incubation temperature. Further, co-expression of wt and mutant monomers does not restore either wt like surface expression or the full hERG current. These results indicate L69P is a dominant negative mutation, with deficits which most likely occurs at the level of protein folding and subsequently inhibits trafficking to the plasma membrane. The functional deficits of the mutant channel support the clinical diagnosis of a LQTS.
Collapse
Affiliation(s)
- Tina Jenewein
- Institute of Legal Medicine, University of Frankfurt, Frankfurt Am Main, Germany
| | - Scott A Kanner
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Daniel Bauer
- Computational Biology and Simulation Group, Department of Biology, Technische Universita ̈t Darmstadt, Darmstadt, Germany
| | - Brigitte Hertel
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Henry M Colecraft
- Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Anna Moroni
- Department of Biosciences and CNR IBF-Mi, University of Milano, Milano, Italy
| | - Gerhard Thiel
- Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Silke Kauferstein
- Institute of Legal Medicine, University of Frankfurt, Frankfurt Am Main, Germany
| |
Collapse
|
15
|
Affiliation(s)
| | - Deborah C Mash
- University of Miami School of Medicine, Neurology & Pharmacology, University of Miami Life Science Bldg., Florida, USA
| |
Collapse
|
16
|
Huang M, Liao Z, Li X, Yang Z, Fan X, Li Y, Zhao Z, Lang S, Cyganek L, Zhou X, Akin I, Borggrefe M, El-Battrawy I. Effects of Antiarrhythmic Drugs on hERG Gating in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes From a Patient With Short QT Syndrome Type 1. Front Pharmacol 2021; 12:675003. [PMID: 34025432 PMCID: PMC8138577 DOI: 10.3389/fphar.2021.675003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 03/02/2021] [Accepted: 04/26/2021] [Indexed: 12/17/2022] Open
Abstract
Aims: The short QT syndrome type 1 (SQT1) is linked to hERG channel mutations (e.g., N588K). Drug effects on hERG channel gating kinetics in SQT1-cells have not been investigated. Methods: This study used hiPSC-CMs of a healthy donor and a SQT1-patient carrying the N588K mutation and patch clamp to examine the drug effects on hERG channel gating kinetics. Results: Ajmaline, amiodarone, ivabradine, flecainide, quinidine, mexiletine and ranolazine inhibited the hERG channel current (IKr) less strongly in hiPSC-CMs from the SQTS1-patient (SQT1-hiPSC-CMs) comparing with cells from the healthy donor (donor-hiPSC-CMs). Quinidine and mexiletine reduced, but ajmaline, amiodarone, ivabradine and ranolazine increased the time to peak of IKr similarly in SQT1-hiPSC-CMs and donor-hiPSC-CMs. Although regarding the shift of activation and inactivation curves, tested drugs showed differential effects in donor- and SQT1-hiPSC-CMs, quinidine, ajmaline, ivabradine and mexiletine but not amiodarone, flecainide and ranolazine reduced the window current in SQT1-hiPSC-CMs. Quinidine, ajmaline, ivabradine and mexiletine differentially changed the time constant of recovery from inactivation, but all of them increased the time constant of deactivation in SQT1-hiPSC-CMs. Conclusion: The window current-reducing and deactivation-slowing effects may be important for the antiarrhythmic effect of ajmaline, ivabradine, quinidine and mexiletine in SQT1-cells. This information may be helpful for selecting drugs for treating SQT1-patients with hERG channel mutation.
Collapse
Affiliation(s)
- Mengying Huang
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Zhenxing Liao
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany.,North Sichuan Medical College, Nanchong, China
| | - Xin Li
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany.,College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Zhen Yang
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany.,North Sichuan Medical College, Nanchong, China
| | - Xuehui Fan
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany.,Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Yingrui Li
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Zhihan Zhao
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Siegfried Lang
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany.,DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Lukas Cyganek
- DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany.,Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - Xiaobo Zhou
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany.,Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China.,DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Ibrahim Akin
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany.,DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Martin Borggrefe
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany.,DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| | - Ibrahim El-Battrawy
- First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany.,DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen, Mannheim, Germany
| |
Collapse
|
17
|
Saponara S, Fusi F, Iovinelli D, Ahmed A, Trezza A, Spiga O, Sgaragli G, Valoti M. Flavonoids and hERG channels: Friends or foes? Eur J Pharmacol 2021; 899:174030. [PMID: 33727059 DOI: 10.1016/j.ejphar.2021.174030] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 10/08/2020] [Revised: 02/28/2021] [Accepted: 03/11/2021] [Indexed: 01/24/2023]
Abstract
The cardiac action potential is regulated by several ion channels. Drugs capable to block these channels, in particular the human ether-à-go-go-related gene (hERG) channel, also known as KV11.1 channel, may lead to a potentially lethal ventricular tachyarrhythmia called "Torsades de Pointes". Thus, evaluation of the hERG channel off-target activity of novel chemical entities is nowadays required to safeguard patients as well as to avoid attrition in drug development. Flavonoids, a large class of natural compounds abundantly present in food, beverages, herbal medicines, and dietary food supplements, generally escape this assessment, though consumed in consistent amounts. Continuously growing evidence indicates that these compounds may interact with the hERG channel and block it. The present review, by examining numerous studies, summarizes the state-of-the-art in this field, describing the most significant examples of direct and indirect inhibition of the hERG channel current operated by flavonoids. A description of the molecular interactions between a few of these natural molecules and the Rattus norvegicus channel protein, achieved by an in silico approach, is also presented.
Collapse
Affiliation(s)
- Simona Saponara
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | - Fabio Fusi
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy.
| | - Daniele Iovinelli
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | - Amer Ahmed
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | - Alfonso Trezza
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | - Ottavia Spiga
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | - Giampietro Sgaragli
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy; Accademia Italiana della Vite e del Vino, via Logge degli Uffizi Corti 1, 50122, Florence, Italy
| | - Massimo Valoti
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| |
Collapse
|
18
|
Gu K, Qian D, Qin H, Cui C, Fernando WCHA, Wang D, Wang J, Cao K, Chen M. A novel mutation in KCNH2 yields loss-of-function of hERG potassium channel in long QT syndrome 2. Pflugers Arch 2021; 473:219-229. [PMID: 33449212 DOI: 10.1007/s00424-021-02518-1] [Citation(s) in RCA: 2] [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] [Received: 01/31/2020] [Revised: 12/24/2020] [Accepted: 01/07/2021] [Indexed: 12/16/2022]
Abstract
Mutations in hERG (human ether-à-go-go-related gene) potassium channel are closely associated with long QT syndromes. By direct Sanger sequencing, we identified a novel KCNH2 mutation W410R in the patient with long QT syndrome 2 (LQT2). However, the electrophysiological functions of this mutation remain unknown. In comparison to hERGWT channels, hERGW410R channels have markedly decreased total and surface expressions. W410R mutation dramatically reduces hERG channel currents (IKr) and shifts its steady-state activation curve to depolarization. Moreover, hERGW410R channels make dominant-negative effects on hERGWT channels. Significantly, we find hERG channel blocker E-4031 could partially rescue the function of hERGW410R channels by increasing the membrane expression. By using in silico model, we reveal that hERGW410R channels obviously elongate the repolarization of human ventricular myocyte action potentials. Collectively, W410R mutation decreases the currents of hERG channel, because of diminished membrane expression of mutant channels, that subsequently leads to elongated repolarization of cardiomyocyte, which might induce the pathogenesis of LQT2. Furthermore, E-4031 could partially rescue the decreased activity of hERGW410R channels. Thus, our work identifies a novel loss-of-function mutation in KCNH2 gene, which might provide a rational basis for the management of LQT2.
Collapse
Affiliation(s)
- Kai Gu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China
| | - Duoduo Qian
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China
| | - Huiyuan Qin
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China
| | - Chang Cui
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China
| | - W C Hewith A Fernando
- Department of Physiology, Nanjing Medical University, 101 Longmian Ave, Nanjing, 211166, China
| | - Daowu Wang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China.,State Key Laboratory of Reproductive Medicine, the Centre for Clinical Reproductive Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Juejin Wang
- Department of Physiology, Nanjing Medical University, 101 Longmian Ave, Nanjing, 211166, China.
| | - Kejiang Cao
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China.
| | - Minglong Chen
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China.
| |
Collapse
|
19
|
Fernández-Villabrille S, Álvarez-González E, Barros F, de la Peña P, Sierra LM. Influence of Kv11.1 (hERG1) K + channel expression on DNA damage induced by the genotoxic agent methyl methanesulfonate. Pflugers Arch 2021; 473:197-217. [PMID: 33452554 DOI: 10.1007/s00424-021-02517-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 12/22/2020] [Accepted: 01/05/2021] [Indexed: 10/22/2022]
Abstract
Besides their crucial role in cell electrogenesis and maintenance of basal membrane potential, the voltage-dependent K+ channel Kv11.1/hERG1 shows an essential impact in cell proliferation and other processes linked to the maintenance of tumour phenotype. To check the possible influence of channel expression on DNA damage responses, HEK293 cells, treated with the genotoxic agent methyl methanesulfonate (MMS), were compared with those of a HEK-derived cell line (H36), permanently transfected with the Kv11.1-encoding gene, and with a third cell line (T2) obtained under identical conditions as H36, by permanent transfection of another unrelated plasma membrane protein encoding gene. In addition, to gain some insights about the canonical/conduction-dependent channel mechanisms that might be involved, the specific erg channel inhibitor E4031 was used as a tool. Our results indicate that the expression of Kv11.1 does not influence MMS-induced changes in cell cycle progression, because no differences were found between H36 and T2 cells. However, the canonical ion conduction function of the channel appeared to be associated with decreased cell viability at low/medium MMS concentrations. Moreover, direct DNA damage measurements, using the comet assay, demonstrated for the first time that Kv11.1 conduction activity was able to modify MMS-induced DNA damage, decreasing it particularly at high MMS concentration, in a way related to PARP1 gene expression. Finally, our data suggest that the canonical Kv11.1 effects may be relevant for tumour cell responses to anti-tumour therapies.
Collapse
|
20
|
Asai T, Adachi N, Moriya T, Oki H, Maru T, Kawasaki M, Suzuki K, Chen S, Ishii R, Yonemori K, Igaki S, Yasuda S, Ogasawara S, Senda T, Murata T. Cryo-EM Structure of K +-Bound hERG Channel Complexed with the Blocker Astemizole. Structure 2021; 29:203-212.e4. [PMID: 33450182 DOI: 10.1016/j.str.2020.12.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/25/2020] [Accepted: 12/10/2020] [Indexed: 12/11/2022]
Abstract
The hERG channel is a voltage-gated potassium channel involved in cardiac repolarization. Off-target hERG inhibition by drugs has become a critical issue in the pharmaceutical industry. The three-dimensional structure of the hERG channel was recently reported at 3.8-Å resolution using cryogenic electron microscopy (cryo-EM). However, the drug inhibition mechanism remains unclear because of the scarce structural information regarding the drug- and potassium-bound hERG channels. In this study, we obtained the cryo-EM density map of potassium-bound hERG channel complexed with astemizole, a well-known hERG inhibitor that increases risk of potentially fatal arrhythmia, at 3.5-Å resolution. The structure suggested that astemizole inhibits potassium conduction by binding directly below the selectivity filter. Furthermore, we propose a possible binding model of astemizole to the hERG channel and provide insights into the unusual sensitivity of hERG to several drugs.
Collapse
Affiliation(s)
- Tatsuki Asai
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Naruhiko Adachi
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1, Oho, Tsukuba 305-0801, Japan
| | - Toshio Moriya
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1, Oho, Tsukuba 305-0801, Japan
| | - Hideyuki Oki
- Axcelead Drug Discovery Partners, Inc., 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-0012, Japan
| | - Takamitsu Maru
- Axcelead Drug Discovery Partners, Inc., 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-0012, Japan
| | - Masato Kawasaki
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1, Oho, Tsukuba 305-0801, Japan
| | - Kano Suzuki
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Sisi Chen
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Ryohei Ishii
- Structure-Based Drug Design Group, Organic Synthesis Department, Daiichi Sankyo RD Novare Co., Ltd, 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan
| | - Kazuko Yonemori
- Drug Safety Research and Evaluation, Research, Takeda Pharmaceutical Company Limited, 26-1 Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Shigeru Igaki
- Drug Safety Research and Evaluation, Research, Takeda Pharmaceutical Company Limited, 26-1 Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Satoshi Yasuda
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan; Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Satoshi Ogasawara
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan; Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Toshiya Senda
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1, Oho, Tsukuba 305-0801, Japan
| | - Takeshi Murata
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan; Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan.
| |
Collapse
|
21
|
Zequn Z, Yujia W, Dingding Q, Jiangfang L. Off-label use of chloroquine, hydroxychloroquine, azithromycin and lopinavir/ritonavir in COVID-19 risks prolonging the QT interval by targeting the hERG channel. Eur J Pharmacol 2020; 893:173813. [PMID: 33345848 PMCID: PMC7746509 DOI: 10.1016/j.ejphar.2020.173813] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [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: 08/01/2020] [Revised: 11/29/2020] [Accepted: 12/11/2020] [Indexed: 12/20/2022]
Abstract
Coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses an enormous challenge to the medical system, especially the lack of safe and effective COVID-19 treatment methods, forcing people to look for drugs that may have therapeutic effects as soon as possible. Some old drugs have shown clinical benefits after a few small clinical trials that attracted great attention. Clinically, however, many drugs, including those currently used in COVID-19, such as chloroquine, hydroxychloroquine, azithromycin, and lopinavir/ritonavir, may cause cardiotoxicity by acting on cardiac potassium channels, especially hERG channel through their off-target effects. The blocking of the hERG channel prolongs QT intervals on electrocardiograms; thus, it might induce severe ventricular arrhythmias and even sudden cardiac death. Therefore, while focusing on the efficacy of COVID-19 drugs, the fact that they block hERG channels to cause arrhythmias cannot be ignored. To develop safer and more effective drugs, it is necessary to understand the interactions between drugs and the hERG channel and the molecular mechanism behind this high affinity. In this review, we focus on the biochemical and molecular mechanistic aspects of drug-related blockade of the hERG channel to provide insights into QT prolongation caused by off-label use of related drugs in COVID-19, and hope to weigh the risks and benefits when using these drugs.
Collapse
Affiliation(s)
- Zheng Zequn
- Medical College, Ningbo University, Ningbo, Zhejiang, 315000, China
| | - Wu Yujia
- Medical College, Ningbo University, Ningbo, Zhejiang, 315000, China
| | - Qian Dingding
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo, Zhejiang, 315211, China
| | - Lian Jiangfang
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo, Zhejiang, 315211, China.
| |
Collapse
|
22
|
Wang Y, Luo Z, Lei S, Li S, Li X, Yuan C. Effects and mechanism of gating modifier spider toxins on the hERG channel. Toxicon 2020; 189:56-64. [PMID: 33212100 DOI: 10.1016/j.toxicon.2020.11.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 08/04/2020] [Revised: 11/11/2020] [Accepted: 11/15/2020] [Indexed: 10/23/2022]
Abstract
Jingzhaotoxin-I, -III, -IV, -XIII, and -35 (JZTX-I, -III, -IV, -XIII, and -35), gating modifier toxins isolated from the venom of the Chinese tarantula Chilobrachys Jingzhao, were reported to act on cardiac sodium channels and Kv channels. JZTX-I and JZTX-XIII inhibited the hERG channel with the IC50 value of 626.9 nM and 612.6 nM, respectively. JZTX-III, -IV, and -35 share high sequence similarity with JZTX-I and JZTX-XIII, but they showed much lower affinity on the hERG channel compared with JZTX-I and JZTX-XIII. The inhibitory potency of the above five toxins on the hERG channel was not in accordance with their affinity on the Nav1.5 and Kv2.1 channels, indicating that the bioactive surfaces of the five toxins interacting with hERG, Nav1.5 and Kv2.1 are at least in part different. Structure-function analysis of the gating modifier toxins suggested that the functional bioactive surface binding to the hERG channel consists of a conserved hydrophobic patch, surrounding acidic residues (Glu10 in JZTX-XIII, Glu11 in JZTX-I), and basic residues which may be different from residues binding to the Kv2.1 channel.
Collapse
Affiliation(s)
- Yingyi Wang
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Zhengyi Luo
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Sheng Lei
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Shuji Li
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Xiaowen Li
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
| | - Chunhua Yuan
- Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
| |
Collapse
|
23
|
Yoon KS, Lee JM, Kim YH, Suh SK, Cha HJ. Cardiotoxic effects of [3-[2-(diethylamino)ethyl]-1H-indol-4-yl] acetate and 3-[2-[ethyl(methyl)amino]ethyl]-1H-indol-4-ol. Toxicol Lett 2019; 319:40-48. [PMID: 31706004 DOI: 10.1016/j.toxlet.2019.10.022] [Citation(s) in RCA: 5] [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] [Received: 07/05/2019] [Revised: 10/06/2019] [Accepted: 10/27/2019] [Indexed: 12/28/2022]
Abstract
Two synthetic tryptamines, namely [3-[2-(diethylamino)ethyl]-1H-indol-4-yl] acetate (4-AcO-DET) and 3-[2-[ethyl(methyl)amino]ethyl]-1H-indol-4-ol (4-HO-MET), are abused by individuals seeking recreational hallucinogens. These new psychoactive substances (NPSs) can cause serious health problems because their adverse effects are mostly unknown. In the present study, we evaluated the cardiotoxicity of 4-AcO-DET and 4-HO-MET using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, electrocardiography (ECG), and the human ether-a-go-go-related gene (hERG) assay. In addition, we analyzed the expression level of p21 (CDC42/RAC)-activated kinase 1 (PAK1), which is known to play various roles in the cardiovascular system. In the MTT assay, 4-AcO-DET- and 4-HO-MET-treated H9c2 cells proliferated in a concentration-dependent manner. Moreover, both substances increased QT intervals (as determined using ECG) in Sprague-Dawley rats and inhibited potassium channels (as verified by the hERG assay) in Chinese hamster ovary cells. However, there was no change in PAK1 expression. Collectively, the results indicated that 4-AcO-DET and 4-HO-MET might cause adverse effects on the cardiovascular system. Further studies are required to confirm the relationship between PAK1 expression and cardiotoxicity. The findings of the present study would provide science-based evidence for scheduling the two NPSs.
Collapse
Affiliation(s)
- Kyung Sik Yoon
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Jin-Moo Lee
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Young-Hoon Kim
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Soo Kyung Suh
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Hye Jin Cha
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| |
Collapse
|
24
|
Gualdani R, Guerrini A, Fantechi E, Tadini-Buoninsegni F, Moncelli MR, Sangregorio C. Superparamagnetic iron oxide nanoparticles (SPIONs) modulate hERG ion channel activity. Nanotoxicology 2019; 13:1197-1209. [PMID: 31437063 DOI: 10.1080/17435390.2019.1650969] [Citation(s) in RCA: 5] [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: 12/18/2022]
Abstract
Superparamagnetic iron oxide nanoparticles (SPIONs) are widely used in various biomedical applications, such as diagnostic agents in magnetic resonance imaging (MRI), for drug delivery vehicles and in hyperthermia treatment of tumors. Although the potential benefits of SPIONs are considerable, there is a distinct need to identify any potential cellular damage associated with their use. Since human ether à go-go-related gene (hERG) channel, a protein involved in the repolarization phase of cardiac action potential, is considered one of the main targets in the drug discovery process, we decided to evaluate the effects of SPIONs on hERG channel activity and to determine whether the oxidation state, the dimensions and the coating of nanoparticles (NPs) can influence the interaction with hERG channel. Using patch clamp recordings, we found that SPIONs inhibit hERG current and this effect depends on the coating of NPs. In particular, SPIONs with covalent coating aminopropylphosphonic acid (APPA) have a milder effect on hERG activity. We observed that the time-course of hERG channel modulation by SPIONs is biphasic, with a transient increase (∼20% of the amplitude) occurring within the first 1-3 min of perfusion of NPs, followed by a slower inhibition. Moreover, in the presence of SPIONs, deactivation kinetics accelerated and the activation and inactivation I-V curves were right-shifted, similarly to the effect described for the binding of other divalent metal ions (e.g. Cd2+ and Zn2+). Finally, our data show that a bigger size and the complete oxidation of SPIONs can significantly decrease hERG channel inhibition. Taken together, these results support the view that Fe2+ ions released from magnetite NPs may represent a cardiac risk factor, since they alter hERG gating and these alterations could compromise the cardiac action potential.
Collapse
Affiliation(s)
- Roberta Gualdani
- Dipartimento di Chimica "Ugo Schiff", Università di Firenze , Sesto Fiorentino , Italy.,Institute of Neuroscience, Laboratory of Cell Physiology, Université Catholique de Louvain , Brussels , Belgium
| | - Andrea Guerrini
- Dipartimento di Chimica "Ugo Schiff", Università di Firenze , Sesto Fiorentino , Italy
| | - Elvira Fantechi
- Dipartimento di Chimica "Ugo Schiff", Università di Firenze , Sesto Fiorentino , Italy
| | | | - Maria Rosa Moncelli
- Dipartimento di Chimica "Ugo Schiff", Università di Firenze , Sesto Fiorentino , Italy
| | - Claudio Sangregorio
- Dipartimento di Chimica "Ugo Schiff", Università di Firenze , Sesto Fiorentino , Italy.,ICCOM-CNR and INSTM , Sesto Fiorentino , Italy
| |
Collapse
|
25
|
Abstract
Based on the scaffold of astemizole and E-4031, four AIE light-up probes (L1-L4) for Human Ether-a-go-go-Related Gene (hERG) potassium channel were developed herein using AIE fluorogen(TPE). These probes showing advantages such as low background interference, superior photostability, acceptable cell toxicity, and potent inhibitory activity, which could be used to image hERG channels at the nanomolar level. These AIE light-up probes hoped to provide guidelines for the design of more advanced AIE sensing and imaging hERG channels to a broad range of applications.
Collapse
Affiliation(s)
- Xiaomeng Zhang
- Key Laboratory of Chemical Biology (MOE), Department of Medicinal Chemistry, School of Pharmacy, Shandong University, Jinan, China
| | - Tingting Liu
- Key Laboratory of Chemical Biology (MOE), Department of Medicinal Chemistry, School of Pharmacy, Shandong University, Jinan, China
| | - Qi Li
- Key Laboratory of Chemical Biology (MOE), Department of Medicinal Chemistry, School of Pharmacy, Shandong University, Jinan, China
| | - Minyong Li
- Key Laboratory of Chemical Biology (MOE), Department of Medicinal Chemistry, School of Pharmacy, Shandong University, Jinan, China
| | - Lupei Du
- Key Laboratory of Chemical Biology (MOE), Department of Medicinal Chemistry, School of Pharmacy, Shandong University, Jinan, China
| |
Collapse
|
26
|
Yoon KS, Yun J, Kim YH, Shin J, Kim SJ, Seo JW, Hyun SA, Suh SK, Cha HJ. 2-(2,5-Dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)ethanamine (25D-NBOMe) and N-(2-methoxybenzyl)-2,5-dimethoxy-4-chlorophenethylamine (25C-NBOMe) induce adverse cardiac effects in vitro and in vivo. Toxicol Lett 2019; 304:50-57. [PMID: 30658151 DOI: 10.1016/j.toxlet.2019.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [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: 08/17/2018] [Revised: 11/21/2018] [Accepted: 01/13/2019] [Indexed: 01/08/2023]
Abstract
Two emerging psychoactive substances, 2-(2,5-dimethoxy-4-methylphenyl)-N-(2-methoxybenzyl)ethanamine (25D-NBOMe) and N-(2-methoxybenzyl)-2,5-dimethoxy-4-chlorophenethylamine (25C-NBOMe), are being abused, leading to fatal and non-fatal intoxications. However, most of their adverse effects have been reported anecdotally. In the present study, cardiotoxicity was evaluated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, rat electrocardiography (ECG), and human ether-a-go-go-related gene (hERG) assay. Expression levels of p21 (CDC42/RAC)-activated kinase 1 (PAK1), one of known biomarkers for cardiotoxicity, were also analyzed. Both 25D-NBOMe and 25C-NBOMe at 100 μM reduced cell viability in MTT assay. At 2.0 mg/kg and 0.75 mg/kg, they prolonged QT intervals in rat ECG. PAK1 was down-regulated by treatment with these two test compounds. Furthermore, potassium channels were inhibited by 25D-NBOMe treatment in hERG assay. Taken together, these results suggest that both 25D-NBOMe and 25C-NBOMe have potential cardiotoxicity, especially regarding cardiac rhythm. Further studies are needed to confirm the relationship between PAK1 down-regulation and cardiotoxicity.
Collapse
Affiliation(s)
- Kyung Sik Yoon
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Jaesuk Yun
- College of Pharmacy, Chungbuk National University, Chungju, Republic of Korea.
| | - Young-Hoon Kim
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Jisoon Shin
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Sung Jin Kim
- Cosmetics Policy Division, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Jung-Wook Seo
- Research Group for Safety Pharmacology, Korea Institute of Toxicology, KRICT, Daejeon, Republic of Korea.
| | - Sung-Ae Hyun
- Research Group for Safety Pharmacology, Korea Institute of Toxicology, KRICT, Daejeon, Republic of Korea.
| | - Soo Kyung Suh
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| | - Hye Jin Cha
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong, Cheongju, Republic of Korea.
| |
Collapse
|
27
|
Thamban Chandrika N, Dennis EK, Shrestha SK, Ngo HX, Green KD, Kwiatkowski S, Deaciuc AG, Dwoskin LP, Watt DS, Garneau-Tsodikova S. N,N'-diaryl-bishydrazones in a biphenyl platform: Broad spectrum antifungal agents. Eur J Med Chem 2018; 164:273-281. [PMID: 30597328 DOI: 10.1016/j.ejmech.2018.12.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [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: 05/11/2018] [Revised: 11/11/2018] [Accepted: 12/17/2018] [Indexed: 11/18/2022]
Abstract
N,N'-Diaryl-bishydrazones of [1,1'-biphenyl]-3,4'-dicarboxaldehyde, [1,1'-biphenyl]-4,4'-dicarboxaldehyde, and 4,4'-bisacetyl-1,1-biphenyl exhibited excellent antifungal activity against a broad spectrum of filamentous and non-filamentous fungi. These N,N'-diaryl-bishydrazones displayed no antibacterial activity in contrast to previously reported N,N'-diamidino-bishydrazones and N-amidino-N'-aryl-bishydrazones. The leading candidate, 4,4'-bis((E)-1-(2-(4-fluorophenyl)hydrazono)ethyl)-1,1'-biphenyl, displayed less hemolysis of murine red blood cells at concentrations at or below that of a control antifungal agent (voriconazole), was fungistatic in a time-kill study, and possessed no mammalian cytotoxicity and no toxicity with respect to hERG inhibition.
Collapse
Affiliation(s)
- Nishad Thamban Chandrika
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA
| | - Emily K Dennis
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA
| | - Sanjib K Shrestha
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA
| | - Huy X Ngo
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA
| | - Keith D Green
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA
| | - Stefan Kwiatkowski
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA; Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA
| | - Agripina Gabriela Deaciuc
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA
| | - Linda P Dwoskin
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA
| | - David S Watt
- Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA; Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, 40536-0509, USA; Lucille Parker Markey Cancer Center, University of Kentucky, Lexington, KY, 40536-0093, USA.
| | - Sylvie Garneau-Tsodikova
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536-0596, USA.
| |
Collapse
|
28
|
Yuan C, Luo Z, Zhou Y, Lei S, Xu C, Peng C, Li S, Li X, Zhu X, Gao T. Removal of hERG potassium channel affinity through introduction of an oxygen atom: Molecular insights from structure-activity relationships of strychnine and its analogs. Toxicol Appl Pharmacol 2018; 360:109-119. [PMID: 30282042 DOI: 10.1016/j.taap.2018.09.042] [Citation(s) in RCA: 4] [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] [Received: 06/07/2018] [Revised: 09/27/2018] [Accepted: 09/27/2018] [Indexed: 11/24/2022]
Abstract
Nux vomica has been effectively used in Traditional Chinese Medicine. The processing of Nux vomica is necessary to reduce toxicity before it can be used in clinical practice. However, the mechanism for processing detoxification is unclear. hERG channels have been subjected to a routine test for compound cardiac toxicity in the drug development process. Therefore, we examined the effects and mechanisms of strychnine and brucine, two main ingredients of Nux vomica, and their N-oxides on hERG channels. Strychnine and brucine exhibited concentration-dependent inhibition of hERG channels with IC50 values of 25.9 μM and 44.18 μM, respectively. However, their nitrogen oxidative derivatives produced by processing of Nux vomica, strychnine N-oxide and brucine N-oxide, lost their activity on hERG channels. Compared to their parent compounds, only an oxygen atom was introduced in the nitrogen oxidative isoforms to compensate for the N+ - charge, suggesting that the protonated nitrogen is the key group for strychnine and brucine binding to hERG channel. Alanine-mutagenesis identified Y652 is the most important residue for strychnine and brucine binding to hERG channel. Y652A mutation increased the IC50 for strychnine and brucine by 21.64-fold and 29.78-fold that of WT IhERG, respectively. Docking simulations suggested that the protonated nitrogen of strychnine and brucine formed a cation-π interaction with the aromatic ring of Y652. This study suggests that introduction of an oxygen to compensate for the N+ - charge could be a useful strategy for reducing hERG potency and increasing the safety margin of alkaloid-type compounds in drug development.
Collapse
Affiliation(s)
- Chunhua Yuan
- Key Laboratory of Mental Health of the Ministry of Education, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Zhengyi Luo
- Key Laboratory of Mental Health of the Ministry of Education, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Ying Zhou
- Key Laboratory of Mental Health of the Ministry of Education, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Sheng Lei
- Key Laboratory of Mental Health of the Ministry of Education, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Changxi Xu
- Key Laboratory of Mental Health of the Ministry of Education, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Chao Peng
- Key Laboratory of Mental Health of the Ministry of Education, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Shuji Li
- Key Laboratory of Mental Health of the Ministry of Education, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Xiaowen Li
- Key Laboratory of Mental Health of the Ministry of Education, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Xinhong Zhu
- Key Laboratory of Mental Health of the Ministry of Education, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
| | - Tianming Gao
- Key Laboratory of Mental Health of the Ministry of Education, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China.
| |
Collapse
|
29
|
Kume S, Shimomura T, Tateyama M, Kubo Y. Two mutations at different positions in the CNBH domain of the hERG channel accelerate deactivation and impair the interaction with the EAG domain. J Physiol 2018; 596:4629-4650. [PMID: 30086184 DOI: 10.1113/jp276208] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [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: 06/19/2018] [Accepted: 08/06/2018] [Indexed: 12/24/2022] Open
Abstract
KEY POINTS In the human ether-a-go-go related gene (hERG) channel, both the ether-a-go-go (EAG) domain in the N-terminal and the cyclic nucleotide (CN) binding homology (CNBH) domain in the C-terminal cytoplasmic region are known to contribute to the characteristic slow deactivation. Mutations of Phe860 in the CNBH domain, reported to fill the CN binding pocket, accelerate the deactivation and decrease the fluorescence resonance energy transfer (FRET) efficiencies between the EAG and CNBH domains. An electrostatic interaction between Arg696 and Asp727 in the C-linker domain, critical for HCN and CNG channels, is not formed in the hERG channel. Mutations of newly identified electrostatically interacting pair, Asp727 in the C-linker and Arg752 in the CNBH domains, accelerate the deactivation and decrease FRET efficiency. Voltage-dependent changes in FRET efficiency were not detected. These results suggest that the acceleration of the deactivation by mutations of C-terminal domains is a result of the lack of interaction between the EAG and CNBH domains. ABSTRACT The human ether-a-go-go related gene (hERG) channel shows characteristic slow deactivation, and the contribution of both of the N-terminal cytoplasmic ether-a-go-go (EAG) domain and the C-terminal cytoplasmic cyclic nucleotide (CN) binding homology (CNBH) domain is well known. The interaction between these domains is known to be critical for slow deactivation. We analysed the effects of mutations in the CNBH domain and its upstream C-linker domain on slow deactivation and the interaction between the EAG and CNBH domains by electrophysiological and fluorescence resonance energy transfer (FRET) analyses using Xenopus oocyte and HEK293T cell expression systems. We first observed that mutations of Phe860 in the CNBH domain, which is reported to fill the CN binding pocket as an intrinsic ligand, accelerate deactivation and eliminate the inter-domain interaction. Next, we observed that the salt bridge between Arg696 and Asp727 in the C-linker domain, which is reported to be critical for the function of CN-regulated channels, is not formed. We newly identified an electrostatically interacting pair critical for slow deactivation: Asp727 and Arg752 in the CNBH domain. Their mutations also impaired the inter-domain interaction. Taking these results together, both mutations of the intrinsic ligand (Phe860) and a newly identified salt bridge pair (Asp727 and Arg752) in the hERG channel accelerated deactivation and also decreased the interaction between the EAG and CNBH domains. Voltage-dependent changes in FRET efficiency between the two domains were not detected. The results suggest that the CNBH domain contributes to slow deactivation of the hERG channel by a mechanism involving the EAG domain.
Collapse
Affiliation(s)
- Shinichiro Kume
- Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI, Hayama, Japan.,Present address: Department of Pathophysiology, Oita University School of Medicine, Yufu, Oita, Japan
| | - Takushi Shimomura
- Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI, Hayama, Japan
| | - Michihiro Tateyama
- Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI, Hayama, Japan
| | - Yoshihiro Kubo
- Division of Biophysics and Neurobiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI, Hayama, Japan
| |
Collapse
|
30
|
Choi SW, Choi SW, Jeon YK, Moon SH, Zhang YH, Kim SJ. Suppression of hERG K + current and cardiac action potential prolongation by 4-hydroxynonenal via dual mechanisms. Redox Biol 2018; 19:190-199. [PMID: 30172983 PMCID: PMC6122396 DOI: 10.1016/j.redox.2018.08.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 08/20/2018] [Accepted: 08/23/2018] [Indexed: 01/08/2023] Open
Abstract
Oxidative stress under pathological conditions, such as ischemia/reperfusion and inflammation, results in the production of various reactive chemicals. Of these chemicals, 4-hydroxynonenal (4-HNE), a peroxidation product of ω6-polyunsaturated fatty acid, has garnered significant attention. However, the effect of 4-HNE on cardiac electrophysiology has not yet been reported. In the present study, we investigated the effects of 4-HNE on several cardiac ion channels, including human ether-a-go-go-related (hERG) channels, using the whole-cell patch clamp technique. Short-term exposure to 100 μM 4-HNE (4-HNE100S), which mimics local levels under oxidative stress, decreased the amplitudes of rapidly activating delayed rectifier K+ current (IKr) in guinea pig ventricular myocytes (GPVMs) and HEK293T cells overexpressing hERG (IhERG). MS analysis revealed the formation of 4-HNE-hERG adduct on specific amino acid residues, including C276, K595, H70, and H687. Long-term treatment (1–3 h) with 10 μM 4-HNE (4-HNE10L), suppressed IKr and IhERG, but not IKs and ICa,L. Action potential duration (APD) of GPVMs was prolonged by 37% and 64% by 4-HNE100S and 4-HNE10L, respectively. Western blot analysis using surface biotinylation revealed a reduction in mature membrane hERG protein after treatment with 4-HNE10L. Proteasomal degradation inhibitors, such as bortezomib, prevented the 4-HNE10L-induced decrease in mature hERG, suggesting a retrograde degradation of membrane hERG due to 4-HNE. Taken together, 4-HNE100S and 4-HNE10L suppressed IhERG via functional inhibition and downregulation of membrane expression of hERG, respectively. The exposure of 4-HNE under pathological oxidative stress may increase the risk of proarrhythmic events via APD prolongation. 4-HNE-mediated hERG channel modification causes cardiac action potential prolongation. 4-HNE inhibits hERG channel by post-translational modification at Cys276, Lys595, His70, and His687. Long-term exposure to 4-HNE decreases membrane hERG channel expression.
Collapse
Affiliation(s)
- Seong Woo Choi
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Stem Cell Biology, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Si Won Choi
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Young Keul Jeon
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sung-Hwan Moon
- Department of Stem Cell Biology, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Yin-Hua Zhang
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea.
| |
Collapse
|
31
|
Abstract
Clenbuterol, a β2-selective adrenergic receptor agonist, is illicitly used in weight loss and performance enhancement and animal production. Increasing evidence demonstrates that clenbuterol induces various kinds of arrhythmias and QTc interval prolongation. However, little is known about the underlying mechanism. Most drugs are associated with QTc prolongation through interfering with human ether-a-go-go-related gene (hERG) K+ channels. The present study aims to investigate the effects and underlying mechanisms of clenbuterol on the hERG channel. HEK 293 cells were transfected with wild type and Y652A or F656A mutants of the hERG channel and treated with clenbuterol. The hERG current was recorded using whole-cell patch-clamp technique, and protein level was evaluated by Western blot. We found that clenbuterol decreases the mature form of the hERG protein at the cell membrane in a concentration- and time-dependent manner, without affecting the immature form. Correspondingly, clenbuterol chronic treatment reduced hERG current to a greater extent compared to acute treatment. In the presence of Brefeldin A (BFA), which was used to block hERG channel trafficking to cell membrane, clenbuterol reduced hERG on plasma membrane to a greater extent than BFA alone. In addition, the hERG channel's drug binding sites mutant Y652A and F656A abolished clenbuterol-mediated hERG reduction and current blockade. In conclusion, clenbuterol reduces hERG channel expression and current by promoting the channel degradation. The effect of clenbuterol on the hERG channel is related to the drug-binding sites, Tyr-652 and Phe-656, located on the S6 domain. This biophysical mechanism may underlie clenbuterol-induced QTc prolongation or arrhythmia.
Collapse
Affiliation(s)
- Ling Luo
- 1 Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Peijing Hu
- 1 Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Changqing Miao
- 1 Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Aiqun Ma
- 1 Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.,2 Key Laboratory of Molecular Cardiology, Shaanxi, China.,3 Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, Shaanxi, China
| | - Tingzhong Wang
- 1 Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.,2 Key Laboratory of Molecular Cardiology, Shaanxi, China.,3 Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, Shaanxi, China
| |
Collapse
|
32
|
Goineau S, Castagné V. Proarrhythmic risk assessment using conventional and new in vitro assays. Regul Toxicol Pharmacol 2017; 88:1-11. [PMID: 28506844 DOI: 10.1016/j.yrtph.2017.05.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 12/01/2016] [Revised: 03/29/2017] [Accepted: 05/11/2017] [Indexed: 11/18/2022]
Abstract
Drug-induced QT prolongation is a major safety issue in the drug discovery process. This study was conducted to assess the electrophysiological responses of four substances using established preclinical assays usually used in regulatory studies (hERG channel or Purkinje fiber action potential) and a new assay (human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs)-field potential). After acute exposure, moxifloxacin and dofetilide concentration-dependently decreased IKr amplitude (IC50 values: 102 μM and 40 nM, respectively) and lengthened action potential (100 μM moxifloxacin: +23% and 10 nM dofetilide: +18%) and field potential (300 μM moxifloxacin: +76% and 10 nM dofetilide: +38%) durations. Dofetilide starting from 30 nM induced arrhythmia in hiPSC-CMs. Overnight application of pentamidine (10 and 100 μM) and arsenic (1 and 10 μM) decreased IKr, whereas they were devoid of effects after acute application. Long-term pentamidine incubation showed a time- and concentration-dependent effect on field potential duration. In conclusion, our data suggest that hiPSC-CMs represent a fully functional cellular electrophysiology model which may significantly improve the predictive validity of in vitro safety studies. Thereafter, lead candidates may be further investigated in patch-clamp assays for mechanistic studies on individual ionic channels or in a multicellular Purkinje fiber preparation for confirmatory studies on cardiac conduction.
Collapse
Affiliation(s)
- Sonia Goineau
- Porsolt, Z.A. de Glatigné, 53940 Le Genest-Saint-Isle, France.
| | | |
Collapse
|
33
|
Chiamvimonvat N, Chen-Izu Y, Clancy CE, Deschenes I, Dobrev D, Heijman J, Izu L, Qu Z, Ripplinger CM, Vandenberg JI, Weiss JN, Koren G, Banyasz T, Grandi E, Sanguinetti MC, Bers DM, Nerbonne JM. Potassium currents in the heart: functional roles in repolarization, arrhythmia and therapeutics. J Physiol 2017; 595:2229-2252. [PMID: 27808412 DOI: 10.1113/jp272883] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [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: 06/15/2016] [Accepted: 10/11/2016] [Indexed: 12/19/2022] Open
Abstract
This is the second of the two White Papers from the fourth UC Davis Cardiovascular Symposium Systems Approach to Understanding Cardiac Excitation-Contraction Coupling and Arrhythmias (3-4 March 2016), a biennial event that brings together leading experts in different fields of cardiovascular research. The theme of the 2016 symposium was 'K+ channels and regulation', and the objectives of the conference were severalfold: (1) to identify current knowledge gaps; (2) to understand what may go wrong in the diseased heart and why; (3) to identify possible novel therapeutic targets; and (4) to further the development of systems biology approaches to decipher the molecular mechanisms and treatment of cardiac arrhythmias. The sessions of the Symposium focusing on the functional roles of the cardiac K+ channel in health and disease, as well as K+ channels as therapeutic targets, were contributed by Ye Chen-Izu, Gideon Koren, James Weiss, David Paterson, David Christini, Dobromir Dobrev, Jordi Heijman, Thomas O'Hara, Crystal Ripplinger, Zhilin Qu, Jamie Vandenberg, Colleen Clancy, Isabelle Deschenes, Leighton Izu, Tamas Banyasz, Andras Varro, Heike Wulff, Eleonora Grandi, Michael Sanguinetti, Donald Bers, Jeanne Nerbonne and Nipavan Chiamvimonvat as speakers and panel discussants. This article summarizes state-of-the-art knowledge and controversies on the functional roles of cardiac K+ channels in normal and diseased heart. We endeavour to integrate current knowledge at multiple scales, from the single cell to the whole organ levels, and from both experimental and computational studies.
Collapse
Affiliation(s)
- Nipavan Chiamvimonvat
- Department of Internal Medicine, University of California, Davis, Genome and Biomedical Science Facility, Rm 6315, Davis, CA, 95616, USA.,Department of Veterans Affairs, Northern California Health Care System, Mather, CA, 95655, USA
| | - Ye Chen-Izu
- Department of Internal Medicine, University of California, Davis, Genome and Biomedical Science Facility, Rm 6315, Davis, CA, 95616, USA.,Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA.,Department of Biomedical Engineering, University of California, Davis, Genome and Biomedical Science Facility, Rm 2303, Davis, CA, 95616, USA
| | - Colleen E Clancy
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Isabelle Deschenes
- Department of Physiology and Biophysics, and Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44109, USA.,Heart and Vascular Research Center, MetroHealth Medical Center, Cleveland, OH, 44109, USA
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Hufelandstrasse 55, 45122, Essen, Germany
| | - Jordi Heijman
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Leighton Izu
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Zhilin Qu
- Division of Cardiology, Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, 3645 MRL, Los Angeles, CA, 90095, USA
| | - Crystal M Ripplinger
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Jamie I Vandenberg
- Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, NSW, 2010, Australia
| | - James N Weiss
- Division of Cardiology, Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, 3645 MRL, Los Angeles, CA, 90095, USA
| | - Gideon Koren
- Cardiovascular Research Center, Rhode Island Hospital and the Cardiovascular Institute, The Warren Alpert Medical School of Brown University, Providence, RI, 02903, USA
| | - Tamas Banyasz
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Eleonora Grandi
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Michael C Sanguinetti
- Department of Internal Medicine, University of Utah, Nora Eccles Harrison Cardiovascular Research & Training Institute, Salt Lake City, UT, 84112, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Jeanne M Nerbonne
- Departments of Developmental Biology and Internal Medicine, Cardiovascular Division, Washington University Medical School, St Louis, MO, 63110, USA
| |
Collapse
|
34
|
Shrestha SK, Kril LM, Green KD, Kwiatkowski S, Sviripa VM, Nickell JR, Dwoskin LP, Watt DS, Garneau-Tsodikova S. Bis(N-amidinohydrazones) and N-(amidino)-N'-aryl-bishydrazones: New classes of antibacterial/antifungal agents. Bioorg Med Chem 2016; 25:58-66. [PMID: 27769670 DOI: 10.1016/j.bmc.2016.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [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: 09/13/2016] [Revised: 10/06/2016] [Accepted: 10/07/2016] [Indexed: 11/18/2022]
Abstract
The emergence of multidrug-resistant bacterial and fungal strains poses a threat to human health that requires the design and synthesis of new classes of antimicrobial agents. We evaluated bis(N-amidinohydrazones) and N-(amidino)-N'-aryl-bishydrazones for their antibacterial and antifungal activities against panels of Gram-positive/Gram-negative bacteria as well as fungi. We investigated their potential to develop resistance against both bacteria and fungi by a multi-step resistance-selection method, explored their potential to induce the production of reactive oxygen species, and assessed their toxicity. In summary, we found that these compounds exhibited broad-spectrum antibacterial and antifungal activities against most of the tested strains with minimum inhibitory concentration (MIC) values ranging from <0.5 to >500μM against bacteria and 1.0 to >31.3μg/mL against fungi; and in most cases, they exhibited either superior or similar antimicrobial activity compared to those of the standard drugs used in the clinic. We also observed minimal emergence of drug resistance to these newly synthesized compounds by bacteria and fungi even after 15 passages, and we found weak to moderate inhibition of the human Ether-à-go-go-related gene (hERG) channel with acceptable IC50 values ranging from 1.12 to 3.29μM. Overall, these studies show that bis(N-amidinohydrazones) and N-(amidino)-N'-aryl-bishydrazones are potentially promising scaffolds for the discovery of novel antibacterial and antifungal agents.
Collapse
Affiliation(s)
- Sanjib K Shrestha
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536-0596, USA
| | - Liliia M Kril
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536-0596, USA; Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA
| | - Keith D Green
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536-0596, USA
| | - Stefan Kwiatkowski
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA; Lucille Parker Markey Cancer Center, University of Kentucky, Lexington, KY 40536-0093, USA
| | - Vitaliy M Sviripa
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA; Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington, KY 40536-0596, USA
| | - Justin R Nickell
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536-0596, USA
| | - Linda P Dwoskin
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536-0596, USA
| | - David S Watt
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA; Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington, KY 40536-0596, USA; Lucille Parker Markey Cancer Center, University of Kentucky, Lexington, KY 40536-0093, USA.
| | - Sylvie Garneau-Tsodikova
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY 40536-0596, USA.
| |
Collapse
|
35
|
Kanters JK, Skibsbye L, Hedley PL, Dembic M, Liang B, Hagen CM, Eschen O, Grunnet M, Christiansen M, Jespersen T. Combined gating and trafficking defect in Kv11.1 manifests as a malignant long QT syndrome phenotype in a large Danish p.F29L founder family. Scand J Clin Lab Invest 2015; 75:699-709. [PMID: 26403377 DOI: 10.3109/00365513.2015.1091090] [Citation(s) in RCA: 6] [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] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Congenital long QT syndrome (LQTS) is a hereditary cardiac channelopathy characterized by delayed ventricular repolarization, syncope, torsades de pointes and sudden cardiac death. Thirty-three members of five apparently 'unrelated' Danish families carry the KCNH2:c.87C> A; p.F29L founder mutation. METHODS AND RESULTS Linkage disequilibrium mapping with microsatellites around KCNH2 enabled us to estimate the age of the founder mutation to be approximately 22 generations, corresponding to around 550 years. Neighbouring-Joining analysis disclosed one early and three later nodes. The median QTc time of the carriers was 490 ms (range: 415-589 ms) and no difference was seen between the different branches of the family. The mutation is malignant with a penetrance of 73%. Ten F29L carriers received implantable defibrillators (ICDs) (median age at implant 20 years), and of those four individuals experienced eight appropriate shocks. Patch-clamp analysis in HEK 293 cells, performed at 34°C disclosed a loss-of-function phenotype with fast deactivation, reduced steady-state inactivation current density and a positive voltage shift in inactivation. Western blotting of HEK 293 cells transfected with KCNH2:WT and KCNH2:c.87C> A revealed a reduced fraction of fully glycosylated hERG:p.F29L suggesting that this mutation results in defective trafficking. CONCLUSION The altered channel gating kinetics in combination with defective trafficking of mutated channels is expected to result in reduced repolarizing current density and, thus, a LQTS phenotype.
Collapse
Affiliation(s)
- Jørgen K Kanters
- a Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Biomedical Sciences , University of Copenhagen , Denmark.,b Department of Cardiology , Herlev and Gentofte Hospitals , Denmark
| | - Lasse Skibsbye
- a Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Biomedical Sciences , University of Copenhagen , Denmark
| | - Paula L Hedley
- c Department for Congenital Disorders , Statens Serum Institut , Denmark.,d MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University , Aarhus , Denmark
| | - Maja Dembic
- a Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Biomedical Sciences , University of Copenhagen , Denmark.,c Department for Congenital Disorders , Statens Serum Institut , Denmark
| | - Bo Liang
- a Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Biomedical Sciences , University of Copenhagen , Denmark
| | - Christian M Hagen
- a Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Biomedical Sciences , University of Copenhagen , Denmark.,c Department for Congenital Disorders , Statens Serum Institut , Denmark
| | - Ole Eschen
- e Department of Cardiology , Center for Cardiovascular Research, Aalborg Sygehus, Aarhus University Hospital , Aarhus , Denmark
| | - Morten Grunnet
- a Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Biomedical Sciences , University of Copenhagen , Denmark
| | - Michael Christiansen
- a Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Biomedical Sciences , University of Copenhagen , Denmark.,c Department for Congenital Disorders , Statens Serum Institut , Denmark
| | - Thomas Jespersen
- a Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Biomedical Sciences , University of Copenhagen , Denmark
| |
Collapse
|
36
|
Gualdani R, Tadini-Buoninsegni F, Roselli M, Defrenza I, Contino M, Colabufo NA, Lentini G. Inhibition of hERG potassium channel by the antiarrhythmic agent mexiletine and its metabolite m-hydroxymexiletine. Pharmacol Res Perspect 2015; 3:e00160. [PMID: 26516576 PMCID: PMC4618635 DOI: 10.1002/prp2.160] [Citation(s) in RCA: 26] [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: 05/27/2015] [Accepted: 06/04/2015] [Indexed: 02/05/2023] Open
Abstract
Mexiletine is a sodium channel blocker, primarily used in the treatment of ventricular arrhythmias. Moreover, recent studies have demonstrated its therapeutic value to treat myotonic syndromes and to relieve neuropathic pain. The present study aims at investigating the direct blockade of hERG potassium channel by mexiletine and its metabolite m-hydroxymexiletine (MHM). Our data show that mexiletine inhibits hERG in a time- and voltage-dependent manner, with an IC50 of 3.7 ± 0.7 μmol/L. Analysis of the initial onset of current inhibition during a depolarizing test pulse indicates mexiletine binds preferentially to the open state of the hERG channel. Looking for a possible mexiletine alternative, we show that m-hydroxymexiletine (MHM), a minor mexiletine metabolite recently reported to be as active as the parent compound in an arrhythmia animal model, is a weaker hERG channel blocker, compared to mexiletine (IC50 = 22.4 ± 1.2 μmol/L). The hERG aromatic residues located in the S6 helix (Tyr652 and Phe656) are crucial in the binding of mexiletine and the different affinities of mexiletine and MHM with hERG channel are interpreted by modeling their corresponding binding interactions through ab initio calculations. The simulations demonstrate that the introduction of a hydroxyl group on the meta-position of the aromatic portion of mexiletine weakens the interaction of the drug xylyloxy moiety with Tyr652. These results provide further insights into the molecular basis of drug/hERG interactions and, in agreement with previously reported results on clofilium and ibutilide analogs, support the possibility of reducing hERG potency and related toxicity by modifying the aromatic pattern of substitution of clinically relevant compounds.
Collapse
Affiliation(s)
- Roberta Gualdani
- Dipartimento di Chimica "Ugo Schiff", Università di Firenze via della Lastruccia 3, Sesto Fiorentino, FI, 50019, Italy
| | - Francesco Tadini-Buoninsegni
- Dipartimento di Chimica "Ugo Schiff", Università di Firenze via della Lastruccia 3, Sesto Fiorentino, FI, 50019, Italy
| | - Mariagrazia Roselli
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari "A. Moro" via Orabona 4, Bari, 70125, Italy
| | - Ivana Defrenza
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari "A. Moro" via Orabona 4, Bari, 70125, Italy
| | - Marialessandra Contino
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari "A. Moro" via Orabona 4, Bari, 70125, Italy
| | - Nicola Antonio Colabufo
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari "A. Moro" via Orabona 4, Bari, 70125, Italy
| | - Giovanni Lentini
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari "A. Moro" via Orabona 4, Bari, 70125, Italy
| |
Collapse
|
37
|
Chae YJ, Lee KJ, Lee HJ, Sung KW, Choi JS, Lee EH, Hahn SJ. Endoxifen, the active metabolite of tamoxifen, inhibits cloned hERG potassium channels. Eur J Pharmacol 2015; 752:1-7. [PMID: 25680947 DOI: 10.1016/j.ejphar.2015.01.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [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: 09/13/2014] [Revised: 01/15/2015] [Accepted: 01/19/2015] [Indexed: 11/27/2022]
Abstract
The effects of tamoxifen, and its active metabolite endoxifen (4-hydroxy-N-desmethyl-tamoxifen), on hERG currents stably expressed in HEK cells were investigated using the whole-cell patch-clamp technique and an immunoblot assay. Tamoxifen and endoxifen inhibited hERG tail currents at -50mV in a concentration-dependent manner with IC50 values of 1.2 and 1.6μM, respectively. The steady-state activation curve of the hERG currents was shifted to the hyperpolarizing direction in the presence of endoxifen. The voltage-dependent inhibition of hERG currents by endoxifen increased steeply in the voltage range of channel activation. The inhibition by endoxifen displayed a shallow voltage dependence (δ=0.18) in the full activation voltage range. A fast application of endoxifen induced a reversible block of hERG tail currents during repolarization in a concentration-dependent manner, which suggested an interaction with the open state of the channel. Endoxifen also decreased the hERG current elicited by a 5s depolarizing pulse to +60mV to inactivate the hERG currents, suggesting an interaction with the activated (open and/or inactivated) states of the channels. Tamoxifen and endoxifen inhibited the hERG channel protein trafficking to the plasma membrane in a concentration-dependent manner with endoxifen being more potent than tamoxifen. These results indicated that tamoxifen and endoxifen inhibited the hERG current by direct channel blockage and by the disruption of channel trafficking to the plasma membrane in a concentration-dependent manner. A therapeutic concentration of endoxifen inhibited the hERG current by preferentially interacting with the activated (open and/or inactivated) states of the channel.
Collapse
Affiliation(s)
- Yun Ju Chae
- Department of Physiology, The Catholic University of Korea, Seoul 137-701, Republic of Korea
| | - Keon Jin Lee
- Department of Physiology, The Catholic University of Korea, Seoul 137-701, Republic of Korea
| | - Hong Joon Lee
- Pharmacology, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea
| | - Ki-Wug Sung
- Pharmacology, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea
| | - Jin-Sung Choi
- College of Pharmacy, Integrated Research Institute of Pharmaceutical, The Catholic University of Korea, Gyeonggi-do, Republic of Korea
| | - Eun Hui Lee
- Department of Physiology, The Catholic University of Korea, Seoul 137-701, Republic of Korea
| | - Sang June Hahn
- Department of Physiology, The Catholic University of Korea, Seoul 137-701, Republic of Korea.
| |
Collapse
|
38
|
He S, Lai Z, Ye Z, Dobbelaar PH, Shah SK, Truong Q, Du W, Guo L, Liu J, Jian T, Qi H, Bakshi RK, Hong Q, Dellureficio J, Reibarkh M, Samuel K, Reddy VB, Mitelman S, Tong SX, Chicchi GG, Tsao KL, Trusca D, Wu M, Shao Q, Trujillo ME, Fernandez G, Nelson D, Bunting P, Kerr J, Fitzgerald P, Morissette P, Volksdorf S, Eiermann GJ, Li C, Zhang B, Howard AD, Zhou YP, Nargund RP, Hagmann WK. Investigation of Cardiovascular Effects of Tetrahydro-β-carboline sstr3 antagonists. ACS Med Chem Lett 2014; 5:748-53. [PMID: 25050159 DOI: 10.1021/ml500028c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [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: 01/22/2014] [Accepted: 04/21/2014] [Indexed: 11/30/2022] Open
Abstract
Antagonism of somatostatin subtype receptor 3 (sstr3) has emerged as a potential treatment of Type 2 diabetes. Unfortunately, the development of our first preclinical candidate, MK-4256, was discontinued due to a dose-dependent QTc (QT interval corrected for heart rate) prolongation observed in a conscious cardiovascular (CV) dog model. As the fate of the entire program rested on resolving this issue, it was imperative to determine whether the observed QTc prolongation was associated with hERG channel (the protein encoded by the human Ether-à-go-go-Related Gene) binding or was mechanism-based as a result of antagonizing sstr3. We investigated a structural series containing carboxylic acids to reduce the putative hERG off-target activity. A key tool compound, 3A, was identified from this SAR effort. As a potent sstr3 antagonist, 3A was shown to reduce glucose excursion in a mouse oGTT assay. Consistent with its minimal hERG activity from in vitro assays, 3A elicited little to no effect in an anesthetized, vagus-intact CV dog model at high plasma drug levels. These results afforded the critical conclusion that sstr3 antagonism is not responsible for the QTc effects and therefore cleared a path for the program to progress.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Guillermo Fernandez
- Department
of Safety Assessment, 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Donald Nelson
- Department
of Safety Assessment, 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Patricia Bunting
- Department
of Safety Assessment, 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Janet Kerr
- Department
of Safety Assessment, 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Patrick Fitzgerald
- Department
of Safety Assessment, 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Pierre Morissette
- Department
of Safety Assessment, 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Sylvia Volksdorf
- Department
of Safety Assessment, 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Hu YT, Hu J, Li T, Wei JJ, Feng J, Du YM, Cao ZJ, Li WX, Wu YL. Open conformation of hERG channel turrets revealed by a specific scorpion toxin BmKKx2. Cell Biosci 2014; 4:18. [PMID: 24725272 PMCID: PMC4108063 DOI: 10.1186/2045-3701-4-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [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: 01/03/2014] [Accepted: 02/11/2014] [Indexed: 11/23/2022] Open
Abstract
Background The human ether-a-go-go-related gene potassium channel (hERG) has an unusual long turret, whose role in recognizing scorpion toxins remains controversial. Here, BmKKx2, the first specific blocker of hERG channel derived from scorpion Mesobuthus martensii, was identified and the turret role of hERG channel was re-investigated using BmKKx2 as a molecular probe. Results BmKKx2 was found to block hERG channel with an IC50 of 6.7 ± 1.7 nM and share similar functional surface with the known hERG channel inhibitor BeKm-1. The alanine-scanning mutagenesis data indicate that different residue substitutions on hERG channel by alanine decreased the affinities of toxin BmKKx2 by about 10-fold compared with that of wild-type hERG channel, which reveals that channel turrets play a secondary role in toxin binding. Different from channel turret, the pore region of hERG channel was found to exert the conserved and essential function for toxin binding because the mutant hERG-S631A channel remarkably decreased toxin BmKKx2 affinity by about 104-fold. Conclusions Our results not only revealed that channel turrets of hERG channel formed an open conformation in scorpion toxin binding, but also enriched the diversity of structure-function relationships among the different potassium channel turrets.
Collapse
Affiliation(s)
- You-Tian Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jun Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Tian Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jing-Jing Wei
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jing Feng
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yi-Mei Du
- Research Center of Ion Channelopathy, Institute of Cardiovascular Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Zhi-Jian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Wen-Xin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Ying-Liang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| |
Collapse
|
40
|
Kim TW, Kim KS, Seo JW, Park SY, Henry SP. Antisense oligonucleotides on neurobehavior, respiratory, and cardiovascular function, and hERG channel current studies. J Pharmacol Toxicol Methods 2013; 69:49-60. [PMID: 24211663 DOI: 10.1016/j.vascn.2013.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/07/2013] [Accepted: 10/31/2013] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Safety Pharmacology studies were conducted in mouse, rat, and non-human primate to determine in vivo effects of antisense oligonucleotides (ASOs) on the central nervous system, respiratory system, and cardiovascular system. Effects on the hERG potassium channel current was evaluated in vitro. METHODS ASOs contained terminal 2'-O-methoxyethyl nucleotides, central deoxy nucleotides, and a phosphorothioate backbone. Neurobehavior was evaluated by Functional Observatory Battery in rodents. Respiratory function was directly measured in rodents by plethysmograph; respiratory rate and blood gases were measured in monkey. Basic cardiovascular endpoints were measured in rat; cardiovascular evaluation in monkey involved implanted telemetry units. In single and repeat dose studies ASOs were administered by subcutaneous injection at up to 300 mg/kg, 250 mg/kg, and 40 mg/kg in mouse, rat, or monkey, respectively. Assays were performed in HEK293 or CHO-K1 cells, stably transfected with hERG cDNA, at ASO concentrations of up to 300 μM. RESULTS No apparent effects were noted for respiratory or CNS function. Continuous monitoring of the cardiovascular system in monkey demonstrated no ASO-related changes in blood pressures, heart rate, or ECG and associated parameters (i.e., QRS duration). Specific assessment of the hERG potassium channel indicated no potential for actions on ventricular repolarization or modest effects only at excessive concentrations. DISCUSSION The absence of direct actions on neurobehavior and respiratory function associated with the administration of ASOs in safety pharmacology core battery studies is consistent with published toxicology studies. The combination of in vitro hERG studies and in vivo studies in rat and monkey are consistent with no direct actions by ASOs on cardiac cell function or electrical conduction at relevant concentrations and dose levels. Taken as a whole, dedicated studies focused on the safety pharmacology of specific organ systems do not appear to add significant data for interpretation of potential adverse effects. The need for dedicated studies for future ASOs in the same class is questionable, as a more encompassing data set can be collected in repeat dose and longer-term toxicology studies.
Collapse
Affiliation(s)
- Tae-Won Kim
- Isis Pharmaceuticals, Inc., 2855 Gazelle Ct., Carlsbad, CA 92010, USA.
| | - Ki-Suk Kim
- Korea Institute of Toxicology, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600, Republic of Korea
| | - Joung-Wook Seo
- Korea Institute of Toxicology, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600, Republic of Korea
| | - Shin-Young Park
- Korea Institute of Toxicology, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 305-600, Republic of Korea
| | - Scott P Henry
- Isis Pharmaceuticals, Inc., 2855 Gazelle Ct., Carlsbad, CA 92010, USA
| |
Collapse
|
41
|
Jo SH, Lee SY. Response of i(kr) and HERG currents to the antipsychotics tiapride and sulpiride. Korean J Physiol Pharmacol 2010; 14:305-10. [PMID: 21165329 DOI: 10.4196/kjpp.2010.14.5.305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 09/07/2010] [Accepted: 09/14/2010] [Indexed: 11/15/2022]
Abstract
The human ether-a-go-go-related gene (hERG) channel is important for repolarization in human myocardium and is a common target for drugs that prolong the QT interval. We studied the effects of two antipsychotics, tiapride and sulpiride, on hERG channels expressed in Xenopus oocytes and also on delayed rectifier K(+) currents in guinea pig cardiomyocytes. Neither the amplitude of the hERG outward currents measured at the end of the voltage pulse, nor the amplitude of hERG tail currents, showed any concentration-dependent changes with either tiapride or sulpiride (3~300 µM). However, our findings did show that tiapride increased the potential for half-maximal activation (V(1/2)) of HERG at 10~300 µM, whereas sulpiride increased the maximum conductance (G(max)) at 3, 10 and 100 µM. In guinea pig ventricular myocytes, bath applications of 100 and 500 µM tiapride at 36℃ blocked rapidly activating delayed rectifier K(+) current (I(Kr)) by 40.3% and 70.0%, respectively. Also, sulpiride at 100 and 500 µM blocked I(Kr) by 38.9% and 76.5%, respectively. However, neither tiapride nor sulpiride significantly affected the slowly activating delayed rectifier K(+) current (I(Ks)) at the same concentrations. Our findings suggest that the concentrations of the antipsychotics required to evoke a 50% inhibition of I(Kr) are well above the reported therapeutic plasma concentrations of free and total compound.
Collapse
Affiliation(s)
- Su-Hyun Jo
- Department of Physiology, Institute of Bioscience and Biotechnology, Kangwon National University School of Medicine, Chuncheon 200-701, Korea
| | | |
Collapse
|