1
|
Hauwanga WN, Yau RCC, Goh KS, Castro Ceron JI, Alphonse B, Singh G, Elamin S, Jamched V, Abraham AA, Purvil J, Devan JN, Valentim G, McBenedict B, Lima Pessôa B, Mesquita ET. Management of Long QT Syndrome: A Systematic Review. Cureus 2024; 16:e62592. [PMID: 39027806 PMCID: PMC11257643 DOI: 10.7759/cureus.62592] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Accepted: 06/18/2024] [Indexed: 07/20/2024] Open
Abstract
Long QT syndrome (LQTS) is a cardiac disorder characterized by prolonged repolarization of the heart's electrical cycle, which can be observed as an extended QT interval on an electrocardiogram (ECG). The safe and effective management of LQTS often necessitates a multifaceted approach encompassing pharmacological treatment, lifestyle modifications, and, in high-risk cases, the implantation of implantable cardioverter-defibrillators (ICDs). Beta-blockers, particularly nadolol and propranolol, are foundational in treating LQTS, especially for high-risk patients, though ICDs are recommended for those with a history of cardiac arrest or recurrent arrhythmic episodes. Intermediate and low-risk patients are usually managed with medical therapy and regular monitoring. Lifestyle modifications, such as avoiding strenuous physical activities and certain medications, play a critical role. Additionally, psychological support is essential due to the anxiety and depression associated with LQTS. Left cardiac sympathetic denervation (LCSD) offers an alternative for those intolerant to beta-blockers or ICDs. For diagnosis and management, advancements in artificial intelligence (AI) are proving beneficial, enhancing early detection and risk stratification. Despite these developments, significant gaps in understanding the pathophysiology and optimal management strategies for LQTS remain. Future research should focus on refining risk stratification, developing new therapeutic approaches, and generating robust data to guide treatment decisions, ultimately aiming for a personalized medicine approach.
Collapse
Affiliation(s)
- Wilhelmina N Hauwanga
- Family Medicine, Faculty of Medicine, Federal University of the State of Rio de Janeiro, Rio de Janeiro, BRA
| | | | - Kang Suen Goh
- Internal Medicine, Monash University Malaysia, Johor Bahru, MYS
| | | | | | - Gurinder Singh
- Neurosurgery, Fluminense Federal University, Niterói, BRA
| | - Sara Elamin
- Neurosurgery, Fluminense Federal University, Niterói, BRA
| | | | | | - Joshi Purvil
- Neurosurgery, Fluminense Federal University, Niterói, BRA
| | - Jeshua N Devan
- Neurosurgery, Fluminense Federal University, Niterói, BRA
| | | | | | | | | |
Collapse
|
2
|
Sleiman Y, Reiken S, Charrabi A, Jaffré F, Sittenfeld LR, Pasquié JL, Colombani S, Lerman BB, Chen S, Marks AR, Cheung JW, Evans T, Lacampagne A, Meli AC. Personalized medicine in the dish to prevent calcium leak associated with short-coupled polymorphic ventricular tachycardia in patient-derived cardiomyocytes. Stem Cell Res Ther 2023; 14:266. [PMID: 37740238 PMCID: PMC10517551 DOI: 10.1186/s13287-023-03502-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 09/14/2023] [Indexed: 09/24/2023] Open
Abstract
BACKGROUND Polymorphic ventricular tachycardia (PMVT) is a rare genetic disease associated with structurally normal hearts which in 8% of cases can lead to sudden cardiac death, typically exercise-induced. We previously showed a link between the RyR2-H29D mutation and a clinical phenotype of short-coupled PMVT at rest using patient-specific hiPSC-derived cardiomyocytes (hiPSC-CMs). In the present study, we evaluated the effects of clinical and experimental anti-arrhythmic drugs on the intracellular Ca2+ handling, contractile and molecular properties in PMVT hiPSC-CMs in order to model a personalized medicine approach in vitro. METHODS Previously, a blood sample from a patient carrying the RyR2-H29D mutation was collected and reprogrammed into several clones of RyR2-H29D hiPSCs, and in addition we generated an isogenic control by reverting the RyR2-H29D mutation using CRIPSR/Cas9 technology. Here, we tested 4 drugs with anti-arrhythmic properties: propranolol, verapamil, flecainide, and the Rycal S107. We performed fluorescence confocal microscopy, video-image-based analyses and biochemical analyses to investigate the impact of these drugs on the functional and molecular features of the PMVT RyR2-H29D hiPSC-CMs. RESULTS The voltage-dependent Ca2+ channel inhibitor verapamil did not prevent the aberrant release of sarcoplasmic reticulum (SR) Ca2+ in the RyR2-H29D hiPSC-CMs, whereas it was prevented by S107, flecainide or propranolol. Cardiac tissue comprised of RyR2-H29D hiPSC-CMs exhibited aberrant contractile properties that were largely prevented by S107, flecainide and propranolol. These 3 drugs also recovered synchronous contraction in RyR2-H29D cardiac tissue, while verapamil did not. At the biochemical level, S107 was the only drug able to restore calstabin2 binding to RyR2 as observed in the isogenic control. CONCLUSIONS By testing 4 drugs on patient-specific PMVT hiPSC-CMs, we concluded that S107 and flecainide are the most potent molecules in terms of preventing the abnormal SR Ca2+ release and contractile properties in RyR2-H29D hiPSC-CMs, whereas the effect of propranolol is partial, and verapamil appears ineffective. In contrast with the 3 other drugs, S107 was able to prevent a major post-translational modification of RyR2-H29D mutant channels, the loss of calstabin2 binding to RyR2. Using patient-specific hiPSC and CRISPR/Cas9 technologies, we showed that S107 is the most efficient in vitro candidate for treating the short-coupled PMVT at rest.
Collapse
Affiliation(s)
- Yvonne Sleiman
- PhyMedExp, University of Montpellier, CNRS, INSERM, Montpellier , France
| | - Steven Reiken
- Department of Physiology and Cellular Biophysics, Clyde and Helen Wu Center for Molecular Cardiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Azzouz Charrabi
- PhyMedExp, University of Montpellier, CNRS, INSERM, Montpellier , France
| | - Fabrice Jaffré
- Department of Surgery, Weill Cornell Medical College, New York, NY, USA
| | - Leah R Sittenfeld
- Department of Physiology and Cellular Biophysics, Clyde and Helen Wu Center for Molecular Cardiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Jean-Luc Pasquié
- PhyMedExp, University of Montpellier, CNRS, INSERM, Montpellier , France
- Department of Cardiology, CHRU of Montpellier, Montpellier, France
| | - Sarah Colombani
- PhyMedExp, University of Montpellier, CNRS, INSERM, Montpellier , France
| | - Bruce B Lerman
- Division of Cardiology, Weill Cornell Medical College, New York, NY, USA
| | - Shuibing Chen
- Department of Surgery, Weill Cornell Medical College, New York, NY, USA
| | - Andrew R Marks
- Department of Physiology and Cellular Biophysics, Clyde and Helen Wu Center for Molecular Cardiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Jim W Cheung
- Division of Cardiology, Weill Cornell Medical College, New York, NY, USA
| | - Todd Evans
- Department of Surgery, Weill Cornell Medical College, New York, NY, USA
| | - Alain Lacampagne
- PhyMedExp, University of Montpellier, CNRS, INSERM, Montpellier , France
| | - Albano C Meli
- PhyMedExp, University of Montpellier, CNRS, INSERM, Montpellier , France.
- CNRS, INSERM, Montpellier Organoid Platform, Biocampus, University of Montpellier, Montpellier, France.
| |
Collapse
|
3
|
Campostrini G, Kosmidis G, Ward-van Oostwaard D, Davis RP, Yiangou L, Ottaviani D, Veerman CC, Mei H, Orlova VV, Wilde AAM, Bezzina CR, Verkerk AO, Mummery CL, Bellin M. Maturation of hiPSC-derived cardiomyocytes promotes adult alternative splicing of SCN5A and reveals changes in sodium current associated with cardiac arrhythmia. Cardiovasc Res 2023; 119:167-182. [PMID: 35394010 PMCID: PMC10022870 DOI: 10.1093/cvr/cvac059] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 02/07/2022] [Accepted: 03/23/2022] [Indexed: 11/13/2022] Open
Abstract
AIMS Human-induced pluripotent stem cell-cardiomyocytes (hiPSC-CMs) are widely used to study arrhythmia-associated mutations in ion channels. Among these, the cardiac sodium channel SCN5A undergoes foetal-to-adult isoform switching around birth. Conventional hiPSC-CM cultures, which are phenotypically foetal, have thus far been unable to capture mutations in adult gene isoforms. Here, we investigated whether tri-cellular cross-talk in a three-dimensional (3D) cardiac microtissue (MT) promoted post-natal SCN5A maturation in hiPSC-CMs. METHODS AND RESULTS We derived patient hiPSC-CMs carrying compound mutations in the adult SCN5A exon 6B and exon 4. Electrophysiological properties of patient hiPSC-CMs in monolayer were not altered by the exon 6B mutation compared with isogenic controls since it is not expressed; further, CRISPR/Cas9-mediated excision of the foetal exon 6A did not promote adult SCN5A expression. However, when hiPSC-CMs were matured in 3D cardiac MTs, SCN5A underwent isoform switch and the functional consequences of the mutation located in exon 6B were revealed. Up-regulation of the splicing factor muscleblind-like protein 1 (MBNL1) drove SCN5A post-natal maturation in microtissues since its overexpression in hiPSC-CMs was sufficient to promote exon 6B inclusion, whilst knocking-out MBNL1 failed to foster isoform switch. CONCLUSIONS Our study shows that (i) the tri-cellular cardiac microtissues promote post-natal SCN5A isoform switch in hiPSC-CMs, (ii) adult splicing of SCN5A is driven by MBNL1 in these tissues, and (iii) this model can be used for examining post-natal cardiac arrhythmias due to mutations in the exon 6B. TRANSLATIONAL PERSPECTIVE The cardiac sodium channel is essential for conducting the electrical impulse in the heart. Postnatal alternative splicing regulation causes mutual exclusive inclusion of fetal or adult exons of the corresponding gene, SCN5A. Typically, immature hiPSCCMs fall short in studying the effect of mutations located in the adult exon. We describe here that an innovative tri-cellular three-dimensional cardiac microtissue culture promotes hiPSC-CMs maturation through upregulation of MBNL1, thus revealing the effect of a pathogenic genetic variant located in the SCN5A adult exon. These results help advancing the use of hiPSC-CMs in studying adult heart disease and for developing personalized medicine applications.
Collapse
Affiliation(s)
- Giulia Campostrini
- Department of Anatomy and Embryology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, The Netherlands
| | - Georgios Kosmidis
- Department of Anatomy and Embryology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, The Netherlands
| | - Dorien Ward-van Oostwaard
- Department of Anatomy and Embryology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, The Netherlands
| | - Richard Paul Davis
- Department of Anatomy and Embryology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, The Netherlands
| | - Loukia Yiangou
- Department of Anatomy and Embryology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, The Netherlands
| | - Daniele Ottaviani
- Department of Biology, University of Padua, 35121 Padua, Italy
- Veneto Institute of Molecular Medicine, 35129 Padua, Italy
| | - Christiaan Cornelis Veerman
- Department of Clinical and Experimental Cardiology, Heart Centre, Amsterdam University Medical Centre, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Hailiang Mei
- Sequencing Analysis Support Core, Leiden University Medical Center, 2333 Leiden, The Netherlands
| | - Valeria Viktorovna Orlova
- Department of Anatomy and Embryology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, The Netherlands
| | - Arthur Arnold Maria Wilde
- Department of Clinical and Experimental Cardiology, Heart Centre, Amsterdam University Medical Centre, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Connie Rose Bezzina
- Department of Clinical and Experimental Cardiology, Heart Centre, Amsterdam University Medical Centre, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Arie Otto Verkerk
- Department of Clinical and Experimental Cardiology, Heart Centre, Amsterdam University Medical Centre, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Christine Lindsay Mummery
- Department of Anatomy and Embryology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, The Netherlands
- Department of Applied Stem Cell Technologies, University of Twente, 7500 AE, Enschede, The Netherlands
| | | |
Collapse
|
4
|
Comollo TW, Zou X, Zhang C, Kesters D, Hof T, Sampson KJ, Kass RS. Exploring mutation specific beta blocker pharmacology of the pathogenic late sodium channel current from patient-specific pluripotent stem cell myocytes derived from long QT syndrome mutation carriers. Channels (Austin) 2022; 16:173-184. [PMID: 35949058 PMCID: PMC9373745 DOI: 10.1080/19336950.2022.2106025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The congenital long QT syndrome (LQTS), one of the most common cardiac channelopathies, is characterized by delayed ventricular repolarization underlying prolongation of the QT interval of the surface electrocardiogram. LQTS is caused by mutations in genes coding for cardiac ion channels or ion channel-associated proteins. The major therapeutic approach to LQTS management is beta blocker therapy which has been shown to be effective in treatment of LQTS variants caused by mutations in K+ channels. However, this approach has been questioned in the treatment of patients identified as LQTS variant 3(LQT3) patients who carry mutations in SCN5A, the gene coding for the principal cardiac Na+ channel. LQT3 mutations are gain of function mutations that disrupt spontaneous Na+ channel inactivation and promote persistent or late Na+ channel current (INaL) that delays repolarization and underlies QT prolongation. Clinical investigation of patients with the two most common LQT3 mutations, the ΔKPQ and the E1784K mutations, found beta blocker treatment a useful therapeutic approach for managing arrhythmias in this patient population. However, there is little experimental data that reveals the mechanisms underlying these antiarrhythmic actions. Here, we have investigated the effects of the beta blocker propranolol on INaL expressed by ΔKPQ and E1784K channels in induced pluripotent stem cells derived from patients carrying these mutations. Our results indicate that propranolol preferentially inhibits INaL expressed by these channels suggesting that the protective effects of propranolol in treating LQT3 patients is due in part to modulation of INaL.
Collapse
Affiliation(s)
- Thomas W. Comollo
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Xinle Zou
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Chuangeng Zhang
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Divya Kesters
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Thomas Hof
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Kevin J. Sampson
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Robert S. Kass
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA,CONTACT Robert S. Kass
| |
Collapse
|
5
|
Song Y, Zheng Z, Lian J. Deciphering Common Long QT Syndrome Using CRISPR/Cas9 in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes. Front Cardiovasc Med 2022; 9:889519. [PMID: 35647048 PMCID: PMC9136094 DOI: 10.3389/fcvm.2022.889519] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 04/22/2022] [Indexed: 11/13/2022] Open
Abstract
From carrying potentially pathogenic genes to severe clinical phenotypes, the basic research in the inherited cardiac ion channel disease such as long QT syndrome (LQTS) has been a significant challenge in explaining gene-phenotype heterogeneity. These have opened up new pathways following the parallel development and successful application of stem cell and genome editing technologies. Stem cell-derived cardiomyocytes and subsequent genome editing have allowed researchers to introduce desired genes into cells in a dish to replicate the disease features of LQTS or replace causative genes to normalize the cellular phenotype. Importantly, this has made it possible to elucidate potential genetic modifiers contributing to clinical heterogeneity and hierarchically manage newly identified variants of uncertain significance (VUS) and more therapeutic options to be tested in vitro. In this paper, we focus on and summarize the recent advanced application of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) combined with clustered regularly interspaced short palindromic repeats/CRISPR-associated system 9 (CRISPR/Cas9) in the interpretation for the gene-phenotype relationship of the common LQTS and presence challenges, increasing our understanding of the effects of mutations and the physiopathological mechanisms in the field of cardiac arrhythmias.
Collapse
Affiliation(s)
- Yongfei Song
- Department of Cardiovascular, Ningbo Institute of Innovation for Combined Medicine and Engineering, Ningbo, China
- Yongfei Song
| | - Zequn Zheng
- Department of Cardiovascular, Medical College, Ningbo University, Ningbo, China
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo, China
| | - Jiangfang Lian
- Department of Cardiovascular, Ningbo Institute of Innovation for Combined Medicine and Engineering, Ningbo, China
- Department of Cardiovascular, Medical College, Ningbo University, Ningbo, China
- Department of Cardiovascular, Lihuili Hospital Affiliated to Ningbo University, Ningbo, China
- *Correspondence: Jiangfang Lian
| |
Collapse
|
6
|
Korkosh VS, Zaytseva AK, Kostareva AA, Zhorov BS. Intersegment Contacts of Potentially Damaging Variants of Cardiac Sodium Channel. Front Pharmacol 2021; 12:756415. [PMID: 34803699 PMCID: PMC8600069 DOI: 10.3389/fphar.2021.756415] [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: 08/10/2021] [Accepted: 10/18/2021] [Indexed: 11/30/2022] Open
Abstract
Over 1,500 missense variants of sodium channel hNav1.5, which are reported in the ClinVar database, are associated with cardiac diseases. For most of the variants, the clinical significance is uncertain (VUS), not provided (NP), or has conflicting interpretations of pathogenicity (CIP). Reclassifying these variants as pathogenic/likely pathogenic (P/LP) variants is important for diagnosing genotyped patients. In our earlier work, several bioinformatics tools and paralogue annotation method consensually predicted that 74 VUS/NP/CIP variants of 54 wild type residues (set w54) are potentially damaging variants (PDVs). Atomic mechanisms underlying dysfunction of the PDVs are unknown. Here we employed a recent cryo-EM structure of the hNav1.5 channel with likely inactivated pore domain (PD) and activated voltage-sensing domains (VSDs), and ad hoc models of the closed and open PD and resting VSDs to explore intersegment contacts of w54 residues. We found that 44 residues from set w54 contact 84 residues with 118 disease missense variants. These include 104 VUS/NP/CIP variants, most of which are associated with the loss-of-function Brugada syndrome (BrS1) or gain-of-function long QT syndrome (LQT3). Matrix representation of the PDVs and their contact variants facilitated recognition of coupled mutations associated with the same disease. In particular, BrS1-associated coupled mutations, which disturb the P-loops region with the selectivity filter slow inactivation gate, would cause the channel dysfunction. Other likely causes of the channel dysfunction include coupled BrS1-associated variants within VSDs that would destabilize their activated states and coupled LQT3-associated variants, which would stabilize the open PD or activated VSDs. Our study proposes mechanisms of channel dysfunction for scores of BrS1- and LQT3-associated variants, confirms status for 82% of PDVs, and suggests damaging status for their contact variants, which are currently categorized as VUS/NP/CIP variants.
Collapse
Affiliation(s)
- Vyacheslav S Korkosh
- Almazov National Medical Research Centre, St. Petersburg, Russia.,Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Anastasia K Zaytseva
- Almazov National Medical Research Centre, St. Petersburg, Russia.,Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Anna A Kostareva
- Almazov National Medical Research Centre, St. Petersburg, Russia.,Department of Women's and Children's Health, Karolinska Institute, Solna, Sweden
| | - Boris S Zhorov
- Almazov National Medical Research Centre, St. Petersburg, Russia.,Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| |
Collapse
|
7
|
Hayama E, Furutani Y, Kawaguchi N, Seki A, Nagashima Y, Okita K, Takeuchi D, Matsuoka R, Inai K, Hagiwara N, Nakanishi T. Induced Pluripotent Stem Cell-Derived Cardiomyocytes with SCN5A R1623Q Mutation Associated with Severe Long QT Syndrome in Fetuses and Neonates Recapitulates Pathophysiological Phenotypes. BIOLOGY 2021; 10:biology10101062. [PMID: 34681161 PMCID: PMC8533193 DOI: 10.3390/biology10101062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/08/2021] [Accepted: 10/13/2021] [Indexed: 12/19/2022]
Abstract
Simple Summary In this study, the induced pluripotent stem cell-derived cardiomyocyte model from a patient with long QT syndrome harboring a heterozygous Nav1.5 R1623Q mutation exhibited prolonged field potential duration corrected by Fridericia’s formula (FPDcF, analogous to QTcF). FPDcF was shortened with mexiletine treatment and increased the frequency of arrhythmia-like EAD events following E4031, an Ikr blocker, administration. These characteristics partly reflect the patient phenotypes. As the R1623Q mutation is related to severe congenital LQT syndrome in fetuses and neonates, the effect of the neonatal variants on the electrophysiological properties of the R1623Q mutant was examined using an automated patch-clamp system. Our results demonstrated that both R1623Q and neonatal R1623Q delayed inactivation of INa and increased late Na current. We speculated that neonatal Nav1.5 ameliorates QTc prolongation. Developmental switching of neonatal/adult Nav1.5 isoforms might play a role in the mechanisms underlying severe long QT syndrome in fetuses and neonates. Abstract The SCN5A R1623Q mutation is one of the most common genetic variants associated with severe congenital long QT syndrome 3 (LQT3) in fetal and neonatal patients. To investigate the properties of the R1623Q mutation, we established an induced pluripotent stem cell (iPSC) cardiomyocyte (CM) model from a patient with LQTS harboring a heterozygous R1623Q mutation. The properties and pharmacological responses of iPSC-CMs were characterized using a multi-electrode array system. The biophysical characteristic analysis revealed that R1623Q increased open probability and persistent currents of sodium channel, indicating a gain-of-function mutation. In the pharmacological study, mexiletine shortened FPDcF in R1623Q-iPSC-CMs, which exhibited prolonged field potential duration corrected by Fridericia’s formula (FPDcF, analogous to QTcF). Meanwhile, E4031, a specific inhibitor of human ether-a-go-go-related gene (hERG) channel, significantly increased the frequency of arrhythmia-like early after depolarization (EAD) events. These characteristics partly reflect the patient phenotypes. To further analyze the effect of neonatal isoform, which is predominantly expressed in the fetal period, on the R1623Q mutant properties, we transfected adult form and neonatal isoform SCN5A of control and R1623Q mutant SCN5A genes to 293T cells. Whole-cell automated patch-clamp recordings revealed that R1623Q increased persistent Na+ currents, indicating a gain-of-function mutation. Our findings demonstrate the utility of LQT3-associated R1623Q mutation-harboring iPSC-CMs for assessing pharmacological responses to therapeutic drugs and improving treatment efficacy. Furthermore, developmental switching of neonatal/adult Nav1.5 isoforms may be involved in the pathological mechanisms underlying severe long QT syndrome in fetuses and neonates.
Collapse
Affiliation(s)
- Emiko Hayama
- Department of Pediatric Cardiology and Adult Congenital Cardiology, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan; (Y.F.); (N.K.); (D.T.); (K.I.); (T.N.)
- Correspondence:
| | - Yoshiyuki Furutani
- Department of Pediatric Cardiology and Adult Congenital Cardiology, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan; (Y.F.); (N.K.); (D.T.); (K.I.); (T.N.)
| | - Nanako Kawaguchi
- Department of Pediatric Cardiology and Adult Congenital Cardiology, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan; (Y.F.); (N.K.); (D.T.); (K.I.); (T.N.)
| | - Akiko Seki
- Department of Preventive Medicine, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan;
- Department of General Medicine, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
- Department of Cardiology, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan;
| | - Yoji Nagashima
- Department of Surgical Pathology, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan;
| | - Keisuke Okita
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto 606-8507, Japan;
| | - Daiji Takeuchi
- Department of Pediatric Cardiology and Adult Congenital Cardiology, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan; (Y.F.); (N.K.); (D.T.); (K.I.); (T.N.)
| | - Rumiko Matsuoka
- Wakamatsukawada Clinic, 10-7 Kawada-cho, Shinjuku-ku, Tokyo 162-0054, Japan;
| | - Kei Inai
- Department of Pediatric Cardiology and Adult Congenital Cardiology, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan; (Y.F.); (N.K.); (D.T.); (K.I.); (T.N.)
| | - Nobuhisa Hagiwara
- Department of Cardiology, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan;
| | - Toshio Nakanishi
- Department of Pediatric Cardiology and Adult Congenital Cardiology, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan; (Y.F.); (N.K.); (D.T.); (K.I.); (T.N.)
| |
Collapse
|
8
|
Nakajima T, Tamura S, Kurabayashi M, Kaneko Y. Towards Mutation-Specific Precision Medicine in Atypical Clinical Phenotypes of Inherited Arrhythmia Syndromes. Int J Mol Sci 2021; 22:ijms22083930. [PMID: 33920294 PMCID: PMC8069124 DOI: 10.3390/ijms22083930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 04/08/2021] [Indexed: 12/19/2022] Open
Abstract
Most causal genes for inherited arrhythmia syndromes (IASs) encode cardiac ion channel-related proteins. Genotype-phenotype studies and functional analyses of mutant genes, using heterologous expression systems and animal models, have revealed the pathophysiology of IASs and enabled, in part, the establishment of causal gene-specific precision medicine. Additionally, the utilization of induced pluripotent stem cell (iPSC) technology have provided further insights into the pathophysiology of IASs and novel promising therapeutic strategies, especially in long QT syndrome. It is now known that there are atypical clinical phenotypes of IASs associated with specific mutations that have unique electrophysiological properties, which raises a possibility of mutation-specific precision medicine. In particular, patients with Brugada syndrome harboring an SCN5A R1632C mutation exhibit exercise-induced cardiac events, which may be caused by a marked activity-dependent loss of R1632C-Nav1.5 availability due to a marked delay of recovery from inactivation. This suggests that the use of isoproterenol should be avoided. Conversely, the efficacy of β-blocker needs to be examined. Patients harboring a KCND3 V392I mutation exhibit both cardiac (early repolarization syndrome and paroxysmal atrial fibrillation) and cerebral (epilepsy) phenotypes, which may be associated with a unique mixed electrophysiological property of V392I-Kv4.3. Since the epileptic phenotype appears to manifest prior to cardiac events in this mutation carrier, identifying KCND3 mutations in patients with epilepsy and providing optimal therapy will help prevent sudden unexpected death in epilepsy. Further studies using the iPSC technology may provide novel insights into the pathophysiology of atypical clinical phenotypes of IASs and the development of mutation-specific precision medicine.
Collapse
|