1
|
Chang G, Aroge FA, Venkateshappa R, Claydon TW, Sun B. Development of an Absolute Quantification Method for hERG Using PRM with Single Isotopologue in-Sample Calibration. ACS OMEGA 2024; 9:33972-33982. [PMID: 39130540 PMCID: PMC11308013 DOI: 10.1021/acsomega.4c04541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 08/13/2024]
Abstract
The human ether-à-go-go-related gene (KCNH2)-encoded protein hERG constitutes the α subunit of the Kv11.1 channel and contributes to the I kr current, which plays an important role in the cardiac action potential. Genetically and xenobiotically triggered malfunctions of hERG can cause arrhythmia. The expression of hERG in various study systems was assessed mainly as the fold change relative to the corresponding control. Here, we developed a simple and sensitive quantitation method using targeted mass spectrometry, i.e., the parallel reaction monitoring approach, to measure the absolute quantity of hERG in copy number. Such measurements do not require controls, and the obtained values can be compared with similar results for any other protein. To effectively avoid matrix effects, we used the heavy-match-light (HML) in-sample calibration approach that requires only a single isotopologue to achieve copy-number quantitation. No significant difference was observed in the results obtained by HML and by the classic standard addition in-sample calibration approach. Using four proteotypic peptides, we quantified the average number of copies of hERG in the HEK293T heterologous expression system as 3.6 ± 0.5 × 106 copies/cell, i.e., 1 million copies/cell for the fully assembled Kv11.1 channel.
Collapse
Affiliation(s)
- Ge Chang
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A1S6, Canada
| | - Fabusuyi A. Aroge
- School
of Mechatronic Systems Engineering, Simon
Fraser University, Surrey, British Columbia V3T0A3, Canada
| | - Ravichandra Venkateshappa
- Department
of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia V5A1S6, Canada
| | - Tom W. Claydon
- Department
of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia V5A1S6, Canada
| | - Bingyun Sun
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A1S6, Canada
| |
Collapse
|
2
|
Zhao Z, Zang X, Niu K, Song W, Wang X, Mügge A, Aweimer A, Hamdani N, Zhou X, Zhao Y, Akin I, El-Battrawy I. Impacts of gene variants on drug effects-the foundation of genotype-guided pharmacologic therapy for long QT syndrome and short QT syndrome. EBioMedicine 2024; 103:105108. [PMID: 38653189 PMCID: PMC11041837 DOI: 10.1016/j.ebiom.2024.105108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 03/20/2024] [Accepted: 03/24/2024] [Indexed: 04/25/2024] Open
Abstract
The clinical significance of optimal pharmacotherapy for inherited arrhythmias such as short QT syndrome (SQTS) and long QT syndrome (LQTS) has been increasingly recognised. The advancement of gene technology has opened up new possibilities for identifying genetic variations and investigating the pathophysiological roles and mechanisms of genetic arrhythmias. Numerous variants in various genes have been proven to be causative in genetic arrhythmias. Studies have demonstrated that the effectiveness of certain drugs is specific to the patient or genotype, indicating the important role of gene-variants in drug response. This review aims to summarize the reported data on the impact of different gene-variants on drug response in SQTS and LQTS, as well as discuss the potential mechanisms by which gene-variants alter drug response. These findings may provide valuable information for future studies on the influence of gene variants on drug efficacy and the development of genotype-guided or precision treatment for these diseases.
Collapse
Affiliation(s)
- Zhihan Zhao
- Heart Center of Henan Provincial People's Hospital, Central China Fuwai Hospital, Central China Fuwai Hospital of Zhengzhou University, Zhengzhou, Henan, 450003, China
| | - Xiaobiao Zang
- Heart Center of Henan Provincial People's Hospital, Central China Fuwai Hospital, Central China Fuwai Hospital of Zhengzhou University, Zhengzhou, Henan, 450003, China
| | - Kerun Niu
- Department of Orthopaedic, Henan Provincial People's Hospital; Zhengzhou University People's Hospital, Zhengzhou, Henan, 450003, China
| | - Weifeng Song
- Heart Center of Henan Provincial People's Hospital, Central China Fuwai Hospital, Central China Fuwai Hospital of Zhengzhou University, Zhengzhou, Henan, 450003, China
| | - Xianqing Wang
- Heart Center of Henan Provincial People's Hospital, Central China Fuwai Hospital, Central China Fuwai Hospital of Zhengzhou University, Zhengzhou, Henan, 450003, China
| | - Andreas Mügge
- Department of Cardiology and Angiology, Bergmannsheil University Hospitals, Ruhr University of Bochum, 44789, Bochum, Germany
| | - Assem Aweimer
- Institute of Physiology, Department of Cellular and Translational Physiology, Medical Faculty and Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany
| | - Nazha Hamdani
- Institute of Physiology, Department of Cellular and Translational Physiology, Medical Faculty and Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany
- HCEMM-Cardiovascular Research Group, Department of Pharmacology and Pharmacotherapy, University of Budapest, Budapest, Hungary
- Department of Physiology, Cardiovascular Research Institute Maastricht University Maastricht, Maastricht, the Netherlands
| | - Xiaobo Zhou
- Cardiology, Angiology, Haemostaseology, and Medical Intensive Care, Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany
- German Center for Cardiovascular Research (DZHK) Partner Site Heidelberg/Mannheim, Medical Centre Mannheim, Heidelberg University, 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, Sichuan, China
| | - Yonghui Zhao
- Heart Center of Henan Provincial People's Hospital, Central China Fuwai Hospital, Central China Fuwai Hospital of Zhengzhou University, Zhengzhou, Henan, 450003, China
| | - Ibrahim Akin
- Cardiology, Angiology, Haemostaseology, and Medical Intensive Care, Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Germany
- German Center for Cardiovascular Research (DZHK) Partner Site Heidelberg/Mannheim, Medical Centre Mannheim, Heidelberg University, Germany
| | - Ibrahim El-Battrawy
- Department of Cardiology and Angiology, Bergmannsheil University Hospitals, Ruhr University of Bochum, 44789, Bochum, Germany
- Institute of Physiology, Department of Cellular and Translational Physiology, Medical Faculty and Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany
| |
Collapse
|
3
|
Yu R, Li P. Computational and experimental studies on the inhibitory mechanism of hydroxychloroquine on hERG. Toxicology 2021; 458:152822. [PMID: 34058295 PMCID: PMC8161735 DOI: 10.1016/j.tox.2021.152822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 05/08/2021] [Accepted: 05/24/2021] [Indexed: 12/26/2022]
Abstract
Hydroxychloroquine (HCQ) was noted to produce severe cardiac arrhythmia, an adverse effect as its use against severe acute respiratory syndrome caused by coronavirus 2 (SAES-CoV-2). HCQ is an antimalarial drug with quinoline structure. Some other quinoline compounds, such as fluoroquinolone antibiotics (FQs), also lead to arrhythmias characterized by QT prolongation. QT prolongation is usually related to the human ether-a-go-go-related gene (hERG) potassium channel inhibitory activity of most drugs. In this research, molecular docking was used to study the potential inhibitory activities of HCQ as well as other quinolines derivatives and hERG potassium channel protein. The possible causes of these QT prolongation effects were revealed. Molecular docking and patch clamp experiments showed that HCQ could bind to hERG and inhibit the efflux of potassium ion preferentially in the repolarization stage. The IC50 of HCQ was 8.6 μM ± 0.8 μM. FQs, which are quinoline derivatives, could also bind to hERG molecules. The binding energies of FQs varied according to their molecular polarity. It was found that drugs with a quinoline structure, particularly with high molecular polarity, can exert a significant potential hERG inhibitory activity. The potential side effects of QT prolongation during the development and use of quinolines should be carefully considered.
Collapse
Affiliation(s)
- Ran Yu
- Department of Bioengineering, Beijing Polytechnic, Daxing District, Beijing, 100176, China.
| | - Peng Li
- SDIC Xinkai Water Environment Investment Co., Ltd, Tongzhou District, Beijing, 101101, China
| |
Collapse
|
4
|
Mousaei M, Kudaibergenova M, MacKerell AD, Noskov S. Assessing hERG1 Blockade from Bayesian Machine-Learning-Optimized Site Identification by Ligand Competitive Saturation Simulations. J Chem Inf Model 2020; 60:6489-6501. [PMID: 33196188 PMCID: PMC7839320 DOI: 10.1021/acs.jcim.0c01065] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Drug-induced cardiotoxicity is a potentially lethal and yet one of the most common side effects with the drugs in clinical use. Most of the drug-induced cardiotoxicity is associated with an off-target pharmacological blockade of K+ currents carried out by the cardiac Human-Ether-a-go-go-Related (hERG1) potassium channel. There is a compulsory preclinical stage safety assessment for the hERG1 blockade for all classes of drugs, which adds substantially to the cost of drug development. The availability of a high-resolution cryogenic electron microscopy (cryo-EM) structure for the channel in its open/depolarized state solved in 2017 enabled the application of molecular modeling for rapid assessment of drug blockade by molecular docking and simulation techniques. More importantly, if successful, in silico methods may allow a path to lead-compound salvaging by mapping out key block determinants. Here, we report the blind application of the site identification by the ligand competitive saturation (SILCS) protocol to map out druggable/regulatory hotspots in the hERG1 channel available for blockers and activators. The SILCS simulations use small solutes representative of common functional groups to sample the chemical space for the entire protein and its environment using all-atom simulations. The resulting chemical maps, FragMaps, explicitly account for receptor flexibility, protein-fragment interactions, and fragment desolvation penalty allowing for rapid ranking of potential ligands as blockers or nonblockers of hERG1. To illustrate the power of the approach, SILCS was applied to a test set of 55 blockers with diverse chemical scaffolds and pIC50 values measured under uniform conditions. The original SILCS model was based on the all-atom modeling of the hERG1 channel in an explicit lipid bilayer and was further augmented with a Bayesian-optimization/machine-learning (BML) stage employing an independent literature-derived training set of 163 molecules. BML approach was used to determine weighting factors for the FragMaps contributions to the scoring function. pIC50 predictions from the combined SILCS/BML approach to the 55 blockers showed a Pearson correlation (PC) coefficient of >0.535 relative to the experimental data. SILCS/BML model was shown to yield substantially improved performance as compared to commonly used rigid and flexible molecular docking methods for a well-established cohort of hERG1 blockers, where no correlation with experimental data was recorded. SILCS/BML results also suggest that a proper weighting of protonation states of common blockers present at physiological pH is essential for accurate predictions of blocker potency. The precalculated and optimized SILCS FragMaps can now be used for the rapid screening of small molecules for their cardiotoxic potential as well as for exploring alternative binding pockets in the hERG1 channel with applications to the rational design of activators.
Collapse
Affiliation(s)
- Mahdi Mousaei
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Meruyert Kudaibergenova
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Alexander D. MacKerell
- Computer-Aided Drug Design Center, Department of Pharmaceutical Science, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - Sergei Noskov
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| |
Collapse
|
5
|
Zhang Y, Dempsey CE, Hancox JC. Electrophysiological characterization of the modified hERG T potassium channel used to obtain the first cryo-EM hERG structure. Physiol Rep 2020; 8:e14568. [PMID: 33091232 PMCID: PMC7580876 DOI: 10.14814/phy2.14568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 01/02/2023] Open
Abstract
The voltage-gated hERG (human-Ether-à-go-go Related Gene) K+ channel plays a fundamental role in cardiac action potential repolarization. Loss-of-function mutations or pharmacological inhibition of hERG leads to long QT syndrome, whilst gain-of-function mutations lead to short QT syndrome. A recent open channel cryo-EM structure of hERG represents a significant advance in the ability to interrogate hERG channel structure-function. In order to suppress protein aggregation, a truncated channel construct of hERG (hERGT ) was used to obtain this structure. In hERGT cytoplasmic domain residues 141 to 350 and 871 to 1,005 were removed from the full-length channel protein. There are limited data on the electrophysiological properties of hERGT channels. Therefore, this study was undertaken to determine how hERGT influences channel function at physiological temperature. Whole-cell measurements of hERG current (IhERG ) were made at 37°C from HEK 293 cells expressing wild-type (WT) or hERGT channels. With a standard +20 mV activating command protocol, neither end-pulse nor tail IhERG density significantly differed between WT and hERGT . However, the IhERG deactivation rate was significantly slower for hERGT . Half-maximal activation voltage (V0.5 ) was positively shifted for hERGT by ~+8 mV (p < .05 versus WT), without significant change to the activation relation slope factor. Neither the voltage dependence of inactivation, nor time course of development of inactivation significantly differed between WT and hERGT , but recovery of IhERG from inactivation was accelerated for hERGT (p < .05 versus WT). Steady-state "window" current was positively shifted for hERGT with a modest increase in the window current peak. Under action potential (AP) voltage clamp, hERGT IhERG showed modestly increased current throughout the AP plateau phase with a significant increase in current integral during the AP. The observed consequences for hERGT IhERG of deletion of the two cytoplasmic regions may reflect changes to electrostatic interactions influencing the voltage sensor domain.
Collapse
Affiliation(s)
- Yihong Zhang
- School of Physiology and Pharmacology and NeuroscienceBiomedical Sciences BuildingThe University of BristolUniversity WalkBristolUK
| | - Christopher E. Dempsey
- School of BiochemistryBiomedical Sciences BuildingThe University of BristolUniversity WalkBristolUK
| | - Jules C. Hancox
- School of Physiology and Pharmacology and NeuroscienceBiomedical Sciences BuildingThe University of BristolUniversity WalkBristolUK
| |
Collapse
|
6
|
Butler A, Helliwell MV, Zhang Y, Hancox JC, Dempsey CE. An Update on the Structure of hERG. Front Pharmacol 2020; 10:1572. [PMID: 32038248 PMCID: PMC6992539 DOI: 10.3389/fphar.2019.01572] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 12/04/2019] [Indexed: 01/22/2023] Open
Abstract
The human voltage-sensitive K+ channel hERG plays a fundamental role in cardiac action potential repolarization, effectively controlling the QT interval of the electrocardiogram. Inherited loss- or gain-of-function mutations in hERG can result in dangerous “long” (LQTS) or “short” QT syndromes (SQTS), respectively, and the anomalous susceptibility of hERG to block by a diverse range of drugs underlies an acquired LQTS. A recent open channel cryo-EM structure of hERG should greatly advance understanding of the molecular basis of hERG channelopathies and drug-induced LQTS. Here we describe an update of recent research that addresses the nature of the particular gated state of hERG captured in the new structure, and the insight afforded by the structure into the molecular basis for high affinity drug block of hERG, the binding of hERG activators and the molecular basis of hERG's peculiar gating properties. Interpretation of the pharmacology of natural SQTS mutants in the context of the structure is a promising approach to understanding the molecular basis of hERG inactivation, and the structure suggests how voltage-dependent changes in the membrane domain may be transmitted to an extracellular “turret” to effect inactivation through aromatic side chain motifs that are conserved throughout the KCNH family of channels.
Collapse
Affiliation(s)
- Andrew Butler
- School of Physiology, Pharmacology and Neuroscience, Medical Sciences Building, Bristol, United Kingdom
| | - Matthew V Helliwell
- School of Physiology, Pharmacology and Neuroscience, Medical Sciences Building, Bristol, United Kingdom
| | - Yihong Zhang
- School of Physiology, Pharmacology and Neuroscience, Medical Sciences Building, Bristol, United Kingdom
| | - Jules C Hancox
- School of Physiology, Pharmacology and Neuroscience, Medical Sciences Building, Bristol, United Kingdom
| | | |
Collapse
|
7
|
Campuzano O, Fernandez-Falgueras A, Lemus X, Sarquella-Brugada G, Cesar S, Coll M, Mates J, Arbelo E, Jordà P, Perez-Serra A, Del Olmo B, Ferrer-Costa C, Iglesias A, Fiol V, Puigmulé M, Lopez L, Pico F, Brugada J, Brugada R. Short QT Syndrome: A Comprehensive Genetic Interpretation and Clinical Translation of Rare Variants. J Clin Med 2019; 8:jcm8071035. [PMID: 31315195 PMCID: PMC6678338 DOI: 10.3390/jcm8071035] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 07/08/2019] [Accepted: 07/11/2019] [Indexed: 12/14/2022] Open
Abstract
Short QT syndrome, one of the most lethal entities associated with sudden cardiac death, is a rare genetic disease characterized by short QT intervals detected by electrocardiogram. Several genetic variants are causally linked to the disease, but there has yet to be a comprehensive analysis of variants among patients with short QT syndrome. To fill this gap, we performed an exhaustive study of variants currently catalogued as deleterious in short QT syndrome according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Analysis of the 32 variants described in the literature determined that only nine (28.12%) have a conclusive pathogenic role. All definitively pathogenic variants are located in KCNQ1, KCNH2, or KCNJ2; three genes encoding potassium channels. Other variants located in genes encoding calcium or sodium channels are associated with electrical alterations concomitant with shortened QT intervals but do not guarantee a diagnosis of short QT syndrome. We recommend caution regarding previously reported variants classified as pathogenic. An exhaustive re-analysis is necessary to clarify the role of each variant before routinely translating genetic findings to the clinical setting.
Collapse
Affiliation(s)
- Oscar Campuzano
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain.
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain.
- Medical Science Department, School of Medicine, University of Girona, 17071 Girona, Spain.
- Biochemistry and Molecular Genetics Department, Hospital Clinic, IDIBAPS, 08036 Barcelona, Spain.
| | | | - Ximena Lemus
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Georgia Sarquella-Brugada
- Medical Science Department, School of Medicine, University of Girona, 17071 Girona, Spain
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
| | - Sergi Cesar
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
| | - Monica Coll
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Jesus Mates
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Elena Arbelo
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | - Paloma Jordà
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | | | - Bernat Del Olmo
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Carles Ferrer-Costa
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Anna Iglesias
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Victoria Fiol
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
| | - Marta Puigmulé
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Laura Lopez
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Ferran Pico
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Josep Brugada
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08950 Barcelona, Spain
- Arrhythmias Unit, Hospital Clinic, University of Barcelona, 08036 Barcelona, Spain
| | - Ramon Brugada
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain.
- Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain.
- Medical Science Department, School of Medicine, University of Girona, 17071 Girona, Spain.
- Cardiology Service, Hospital Josep Trueta, University of Girona, 17007 Girona, Spain.
| |
Collapse
|