1
|
Djemai M, Jalouli M, Chahine M. Impacts of DCM-linked gating pore currents on the electrophysiological characteristics of hiPSC-CM monolayers. Biochem Biophys Res Commun 2024; 723:150175. [PMID: 38820625 DOI: 10.1016/j.bbrc.2024.150175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 05/20/2024] [Accepted: 05/24/2024] [Indexed: 06/02/2024]
Abstract
BACKGROUND Variants of the SCN5A gene, which encodes the NaV1.5 cardiac sodium channel, have been linked to arrhythmic disorders associated with dilated cardiomyopathy (DCM). However, the precise pathological mechanisms remain elusive. The present study aimed to elucidate the pathophysiological consequences of the DCM-linked Nav1.5/R219H variant, which is known to generate a gating pore current, using patient-specific human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) cultured in monolayers. METHODS Ventricular- and atrial-like hiPSC-CM monolayers were generated from DCM patients carrying the R219H SCN5A variant as well as from healthy control individuals. CRISPR-corrected hiPSC-CMs served as isogenic controls. Simultaneous optical mapping of action potentials (APs) and calcium transients (CaTs) was employed to measure conduction velocities (CVs) and AP durations (APDs) and served as markers of electrical excitability. Calcium handling was evaluated by assessing CaT uptake (half-time to peak), recapture (tau of decay), and durations (TD50 and TD80). A multi-electrode array (MEA) analysis was conducted on hiPSC-CM monolayers to measure field potential (FP) parameters, including corrected Fridericia FP durations (FPDc). RESULTS Our results revealed that CVs were significantly reduced by more than 50 % in both ventricular- and atrial-like hiPSC-CM monolayers carrying the R219H variant compared to the control group. APDs were also prolonged in the R219H group compared to the control and CRISPR-corrected groups. CaT uptake, reuptake, and duration were also markedly delayed in the R219H group compared to the control and CRISPR-corrected groups in both the ventricular- and the atrial-like hiPSC-CM monolayers. Lastly, the MEA data revealed a notably prolonged FPDc in the ventricular- and atrial-like hiPSC-CMs carrying the R219H variant compared to the control and isogenic control groups. CONCLUSIONS These findings highlight the impact of the gating pore current on AP propagation and calcium homeostasis within a functional syncytium environment and offer valuable insights into the potential mechanisms underlying DCM pathophysiology.
Collapse
Affiliation(s)
| | - Maroua Jalouli
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia
| | - Mohamed Chahine
- CERVO Brain Research Centre, Quebec City, Quebec, Canada; Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada.
| |
Collapse
|
2
|
Marchal GA, Rivaud MR, Wolswinkel R, Basso C, van Veen TAB, Bezzina CR, Remme CA. Genetic background determines the severity of age-dependent cardiac structural abnormalities and arrhythmia susceptibility in Scn5a-1798insD mice. Europace 2024; 26:euae153. [PMID: 38875491 PMCID: PMC11203918 DOI: 10.1093/europace/euae153] [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: 02/09/2024] [Accepted: 05/12/2024] [Indexed: 06/16/2024] Open
Abstract
AIMS Patients with mutations in SCN5A encoding NaV1.5 often display variable severity of electrical and structural alterations, but the underlying mechanisms are not fully elucidated. We here investigate the combined modulatory effect of genetic background and age on disease severity in the Scn5a1798insD/+ mouse model. METHODS AND RESULTS In vivo electrocardiogram and echocardiograms, ex vivo electrical and optical mapping, and histological analyses were performed in adult (2-7 months) and aged (8-28 months) wild-type (WT) and Scn5a1798insD/+ (mutant, MUT) mice from the FVB/N and 129P2 inbred strains. Atrio-ventricular (AV) conduction, ventricular conduction, and ventricular repolarization are modulated by strain, genotype, and age. An aging effect was present in MUT mice, with aged MUT mice of both strains showing prolonged QRS interval and right ventricular (RV) conduction slowing. 129P2-MUT mice were severely affected, with adult and aged 129P2-MUT mice displaying AV and ventricular conduction slowing, prolonged repolarization, and spontaneous arrhythmias. In addition, the 129P2 strain appeared particularly susceptible to age-dependent electrical, functional, and structural alterations including RV conduction slowing, reduced left ventricular (LV) ejection fraction, RV dilatation, and myocardial fibrosis as compared to FVB/N mice. Overall, aged 129P2-MUT mice displayed the most severe conduction defects, RV dilatation, and myocardial fibrosis, in addition to the highest frequency of spontaneous arrhythmia and inducible arrhythmias. CONCLUSION Genetic background and age both modulate disease severity in Scn5a1798insD/+ mice and hence may explain, at least in part, the variable disease expressivity observed in patients with SCN5A mutations. Age- and genetic background-dependent development of cardiac structural alterations furthermore impacts arrhythmia risk. Our findings therefore emphasize the importance of continued assessment of cardiac structure and function in patients carrying SCN5A mutations.
Collapse
Affiliation(s)
- Gerard A Marchal
- Department of Experimental Cardiology, Heart Centre, Amsterdam UMC location University of Amsterdam, Meibergdreef 15, PO Box 22660, 1100 DD Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Meibergdreef 15, PO Box 22660, 1100 DD Amsterdam, The Netherlands
- OptoCARD Lab, Institute of Clinical Physiology (IFC-CNR), Florence, Italy
| | - Mathilde R Rivaud
- Department of Experimental Cardiology, Heart Centre, Amsterdam UMC location University of Amsterdam, Meibergdreef 15, PO Box 22660, 1100 DD Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Meibergdreef 15, PO Box 22660, 1100 DD Amsterdam, The Netherlands
| | - Rianne Wolswinkel
- Department of Experimental Cardiology, Heart Centre, Amsterdam UMC location University of Amsterdam, Meibergdreef 15, PO Box 22660, 1100 DD Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Meibergdreef 15, PO Box 22660, 1100 DD Amsterdam, The Netherlands
| | - Cristina Basso
- Department of Cardiac, Thoracic and Vascular Sciences and Public Health, University of Padova, Padua, Italy
| | - Toon A B van Veen
- Department of Medical Physiology, Division Heart & Lungs, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Connie R Bezzina
- Department of Experimental Cardiology, Heart Centre, Amsterdam UMC location University of Amsterdam, Meibergdreef 15, PO Box 22660, 1100 DD Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Meibergdreef 15, PO Box 22660, 1100 DD Amsterdam, The Netherlands
| | - Carol Ann Remme
- Department of Experimental Cardiology, Heart Centre, Amsterdam UMC location University of Amsterdam, Meibergdreef 15, PO Box 22660, 1100 DD Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Meibergdreef 15, PO Box 22660, 1100 DD Amsterdam, The Netherlands
| |
Collapse
|
3
|
Nosetti L, Zaffanello M, Lombardi C, Gerosa A, Piacentini G, Abramo M, Agosti M. Early Screening for Long QT Syndrome and Cardiac Anomalies in Infants: A Comprehensive Study. Clin Pract 2024; 14:1038-1053. [PMID: 38921260 PMCID: PMC11203353 DOI: 10.3390/clinpract14030082] [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: 02/11/2024] [Revised: 03/26/2024] [Accepted: 05/30/2024] [Indexed: 06/27/2024] Open
Abstract
(1) Background: Sudden Infant Death Syndrome (SIDS) represents sudden and unexplained deaths during the sleep of infants under one year of age, despite thorough investigation. Screening for a prolonged QTc interval, a marker for Long QT Syndrome (LQTS), should be conducted on all newborns to reduce the incidence of SIDS. Neonatal electrocardiograms (ECGs) could identify congenital heart defects (CHDs) early, especially those not detected at birth. Infants with prolonged QTc intervals typically undergo genetic analysis for Long QT Syndrome. (2) Methods: The study involved infants aged 20-40 days, born with no apparent clinical signs of heart disease, with initial ECG screening. Infants with prenatal diagnoses or signs/symptoms of CHDs identified immediately after birth, as well as infants who had previously had an ECG or echocardiogram for other medical reasons, were excluded from the study. We used statistical software (SPSS version 22.0) to analyze the data. (3) Results: Of the 42,200 infants involved, 2245 were enrolled, with 39.9% being males. Following this initial screening, 164 children (37.8% males) with prolonged QTc intervals underwent further evaluation. Out of these 164 children, 27 children were confirmed to have LQTS. However, only 18 children were finally investigated for genetic mutations, and mutations were identified in 11 tests. The most common mutations were LQT1 (54.5%), LQT2 (36.4%), and LQT3 (1 patient). Treatment options included propranolol (39.8%), nadolol (22.2%), inderal (11.1%), metoprolol (11.1%), and no treatment (16.7%). The most common abnormalities were focal right bundle branch block (54.5%), left axis deviation (9.2%), and nonspecific ventricular repolarization abnormalities (7.1%). Multiple anomalies were found in 0.47% of children with focal right bundle branch block. Structural abnormalities were associated with specific features in 267 patients (11.9%), primarily isolated patent foramen ovale (PFO) at 61.4%. (4) Conclusions: This screening approach has demonstrated effectiveness in the early identification of LQTS and other cardiac rhythm anomalies, with additional identification of mutations and/or prolonged QTc intervals in family members. Identifying other ECG abnormalities and congenital heart malformations further enhances the benefits of the screening.
Collapse
Affiliation(s)
- Luana Nosetti
- Pediatric Sleep Disorders Center, Division of Pediatrics, “F. Del Ponte” Hospital, University of Insubria, 21100 Varese, Italy; (L.N.)
| | - Marco Zaffanello
- Department of Surgery, Dentistry, Pediatrics and Gynecology, University of Verona, 37100 Verona, Italy
| | - Carolina Lombardi
- Sleep Disorders Center, Department of Cardiology Istituto Auxologico, IRCCS, 20149 Milan, Italy
- Department of Medicine and Surgery, University of Milano-Bicocca, 20126 Milan, Italy
| | - Alessandra Gerosa
- Pediatric Sleep Disorders Center, Division of Pediatrics, “F. Del Ponte” Hospital, University of Insubria, 21100 Varese, Italy; (L.N.)
| | - Giorgio Piacentini
- Department of Surgery, Dentistry, Pediatrics and Gynecology, University of Verona, 37100 Verona, Italy
| | - Michele Abramo
- Pediatric Sleep Disorders Center, Division of Pediatrics, “F. Del Ponte” Hospital, University of Insubria, 21100 Varese, Italy; (L.N.)
| | - Massimo Agosti
- Woman and Child Department, Varese Hospital, Insubria University, Via Ravasi 2, 21100 Varese, Italy;
| |
Collapse
|
4
|
Chapotte-Baldacci CA, Pierre M, Djemai M, Pouliot V, Chahine M. Biophysical properties of Na V1.5 channels from atrial-like and ventricular-like cardiomyocytes derived from human induced pluripotent stem cells. Sci Rep 2023; 13:20685. [PMID: 38001331 PMCID: PMC10673932 DOI: 10.1038/s41598-023-47310-6] [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: 07/14/2023] [Accepted: 11/12/2023] [Indexed: 11/26/2023] Open
Abstract
Generating atrial-like cardiomyocytes derived from human induced pluripotent stem cells (hiPSCs) is crucial for modeling and treating atrial-related diseases, such as atrial arrythmias including atrial fibrillations. However, it is essential to obtain a comprehensive understanding of the electrophysiological properties of these cells. The objective of the present study was to investigate the molecular, electrical, and biophysical properties of several ion channels, especially NaV1.5 channels, in atrial hiPSC cardiomyocytes. Atrial cardiomyocytes were obtained by the differentiation of hiPSCs treated with retinoic acid (RA). The quality of the atrial specification was assessed by qPCR, immunocytofluorescence, and western blotting. The electrophysiological properties of action potentials (APs), Ca2+ dynamics, K+ and Na+ currents were investigated using patch-clamp and optical mapping approaches. We evaluated mRNA transcript and protein expressions to show that atrial cardiomyocytes expressed higher atrial- and sinoatrial-specific markers (MYL7, CACNA1D) and lower ventricular-specific markers (MYL2, CACNA1C, GJA1) than ventricular cardiomyocytes. The amplitude, duration, and steady-state phase of APs in atrial cardiomyocytes decreased, and had a shape similar to that of mature atrial cardiomyocytes. Interestingly, NaV1.5 channels in atrial cardiomyocytes exhibited lower mRNA transcripts and protein expression, which could explain the lower current densities recorded by patch-clamp. Moreover, Na+ currents exhibited differences in activation and inactivation parameters. These differences could be explained by an increase in SCN2B regulatory subunit expression and a decrease in SCN1B and SCN4B regulatory subunit expressions. Our results show that a RA treatment made it possible to obtain atrial cardiomyocytes and investigate differences in NaV1.5 channel properties between ventricular- and atrial-like cells.
Collapse
Affiliation(s)
- Charles-Albert Chapotte-Baldacci
- Department of Medicine, Laval University, Quebec City, QC, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - Marion Pierre
- Department of Medicine, Laval University, Quebec City, QC, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - Mohammed Djemai
- Department of Medicine, Laval University, Quebec City, QC, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - Valérie Pouliot
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - Mohamed Chahine
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada.
| |
Collapse
|
5
|
Calloe K, Magnusson HBD, Lildballe DL, Christiansen MK, Jensen HK. Multifocal ectopic purkinje-related premature contractions and related cardiomyopathy. Front Cardiovasc Med 2023; 10:1179018. [PMID: 37600057 PMCID: PMC10436533 DOI: 10.3389/fcvm.2023.1179018] [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: 03/03/2023] [Accepted: 07/24/2023] [Indexed: 08/22/2023] Open
Abstract
In the past 20 years, genetic variants in SCN5A encoding the cardiac voltage-gated sodium channel Nav1.5 have been linked to a range of inherited cardiac arrhythmias: variants resulting in loss-of-function of Nav1.5 have been linked to sick sinus syndrome, atrial stand still, atrial fibrillation (AF) impaired pulse generation, progressive and non-progressive conduction defects, the Brugada Syndrome (BrS), and sudden cardiac death. SCN5A variants causing increased sodium current during the plateau phase of the cardiac action potential is associated with Long QT Syndrome type 3 (LQTS3), Torsade de Pointes ventricular tachycardia and SCD. Recently, gain-of-function variants have been linked to complex electrical phenotypes, such as the Multifocal Ectopic Purkinje-related Premature Contractions (MEPPC) syndrome. MEPPC is a rare condition characterized by a high burden of premature atrial contractions (PACs) and/or premature ventricular contractions (PVCs) often accompanied by dilated cardiomyopathy (DCM). MEPPC is inherited in an autosomal dominant fashion with an almost complete penetrance. The onset is often in childhood. The link between SCN5A variants, MEPPC and DCM is currently not well understood, but amino acid substitutions resulting in gain-of-function of Nav1.5 or introduction of gating pore currents potentially play an important role. DCM patients with a MEPPC phenotype respond relatively poorly to standard heart failure medical therapy and catheter ablation as the PVCs originate from all parts of the fascicular Purkinje fiber network. Class 1c sodium channel inhibitors, notably flecainide, have a remarkable positive effect on the ectopic burden and the associated cardiomyopathy. This highlights the importance of genetic screening of DCM patients to identify patients with SCN5A variants associated with MEPPC. Here we review the MEPPC phenotype, MEPPC-SCN5A associated variants, and pathogenesis as well as treatment options.
Collapse
Affiliation(s)
- Kirstine Calloe
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Helena B. D. Magnusson
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | | | - Henrik Kjærulf Jensen
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| |
Collapse
|
6
|
Kostritskii AY, Machtens JP. Domain- and state-specific shape of the electric field tunes voltage sensing in voltage-gated sodium channels. Biophys J 2023; 122:1807-1821. [PMID: 37077046 PMCID: PMC10209041 DOI: 10.1016/j.bpj.2023.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 03/27/2023] [Accepted: 04/12/2023] [Indexed: 04/21/2023] Open
Abstract
The ability to sense transmembrane voltage underlies most physiological roles of voltage-gated sodium (Nav) channels. Whereas the key role of their voltage-sensing domains (VSDs) in channel activation is well established, the molecular underpinnings of voltage coupling remain incompletely understood. Voltage-dependent energetics of the activation process can be described in terms of the gating charge that is defined by coupling of charged residues to the external electric field. The shape of the electric field within VSDs is therefore crucial for the activation of voltage-gated ion channels. Here, we employed molecular dynamics simulations of cardiac Nav1.5 and bacterial NavAb, together with our recently developed tool g_elpot, to gain insights into the voltage-sensing mechanisms of Nav channels via high-resolution quantification of VSD electrostatics. In contrast to earlier low-resolution studies, we found that the electric field within VSDs of Nav channels has a complex isoform- and domain-specific shape, which prominently depends on the activation state of a VSD. Different VSDs vary not only in the length of the region where the electric field is focused but also differ in their overall electrostatics, with possible implications in the diverse ion selectivity of their gating pores. Due to state-dependent field reshaping, not only translocated basic but also relatively immobile acidic residues contribute significantly to the gating charge. In the case of NavAb, we found that the transition between structurally resolved activated and resting states results in a gating charge of 8e, which is noticeably lower than experimental estimates. Based on the analysis of VSD electrostatics in the two activation states, we propose that the VSD likely adopts a deeper resting state upon hyperpolarization. In conclusion, our results provide an atomic-level description of the gating charge, demonstrate diversity in VSD electrostatics, and reveal the importance of electric-field reshaping for voltage sensing in Nav channels.
Collapse
Affiliation(s)
- Andrei Y Kostritskii
- Institute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Forschungszentrum Jülich, Jülich, Germany; Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany.
| | - Jan-Philipp Machtens
- Institute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Forschungszentrum Jülich, Jülich, Germany; Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany.
| |
Collapse
|
7
|
Marchal GA, Remme CA. Subcellular diversity of Nav1.5 in cardiomyocytes: distinct functions, mechanisms and targets. J Physiol 2023; 601:941-960. [PMID: 36469003 DOI: 10.1113/jp283086] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/24/2022] [Indexed: 12/11/2022] Open
Abstract
In cardiomyocytes, the rapid depolarisation of the membrane potential is mediated by the α-subunit of the cardiac voltage-gated Na+ channel (NaV 1.5), encoded by the gene SCN5A. This ion channel allows positively charged Na+ ions to enter the cardiomyocyte, resulting in the fast upstroke of the action potential and is therefore crucial for cardiac excitability and electrical propagation. This essential role is underscored by the fact that dysfunctional NaV 1.5 is associated with high risk for arrhythmias and sudden cardiac death. However, development of therapeutic interventions regulating NaV 1.5 has been limited due to the complexity of NaV 1.5 structure and function and its diverse roles within the cardiomyocyte. In particular, research from the last decade has provided us with increased knowledge on the subcellular distribution of NaV 1.5 as well as the proteins which it interacts with in distinct cardiomyocyte microdomains. We here review these insights, detailing the potential role of NaV 1.5 within subcellular domains as well as its dysfunction in the setting of arrhythmia disorders. We furthermore provide an overview of current knowledge on the pathways involved in (microdomain-specific) trafficking of NaV 1.5, and their potential as novel targets. Unravelling the complexity of NaV 1.5 (dys)function may ultimately facilitate the development of therapeutic strategies aimed at preventing lethal arrhythmias. This is not only of importance for pathophysiological conditions where sodium current is specifically decreased within certain subcellular regions, such as in arrhythmogenic cardiomyopathy and Duchenne muscular dystrophy, but also for other acquired and inherited disorders associated with NaV 1.5.
Collapse
Affiliation(s)
- Gerard A Marchal
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands.,National Institute of Optics, National Research Council (CNR-INO), Sesto Fiorentino, Florence, Italy
| | - Carol Ann Remme
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
8
|
Calloe K, Geryk M, Freude K, Treat JA, Vold VA, Frederiksen HRS, Broendberg AK, Frederiksen TC, Jensen HK, Cordeiro JM. The G213D variant in Nav1.5 alters sodium current and causes an arrhythmogenic phenotype resulting in a multifocal ectopic Purkinje-related premature contraction phenotype in human-induced pluripotent stem cell-derived cardiomyocytes. Europace 2022; 24:2015-2027. [PMID: 35726875 DOI: 10.1093/europace/euac090] [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: 12/01/2021] [Accepted: 05/12/2022] [Indexed: 12/14/2022] Open
Abstract
AIMS Variants in SCN5A encoding Nav1.5 are associated with cardiac arrhythmias. We aimed to determine the mechanism by which c.638G>A in SCNA5 resulting in p.Gly213Asp (G213D) in Nav1.5 altered Na+ channel function and how flecainide corrected the defect in a family with multifocal ectopic Purkinje-related premature contractions (MEPPC)-like syndrome. METHODS AND RESULTS Five patients carrying the G213D variant were treated with flecainide. Gating pore currents were evaluated in Xenopus laevis oocytes. The 638G>A SCN5A variant was introduced to human-induced pluripotent stem cell (hiPSC) by CRISPR-Cas9 gene editing and subsequently differentiated to cardiomyocytes (hiPSC-CM). Action potentials and sodium currents were measured in the absence and presence of flecainide. Ca2+ transients were measured by confocal microscopy. The five patients exhibited premature atrial and ventricular contractions which were suppressed by flecainide treatment. G213D induced gating pore current at potentials negative to -50 mV. Voltage-clamp analysis in hiPSC-CM revealed the activation threshold of INa was shifted in the hyperpolarizing direction resulting in a larger INa window current. The G213D hiPSC-CMs had faster beating rates compared with wild-type and frequently showed Ca2+ waves and alternans. Flecainide applied to G213D hiPSC-CMs decreased window current by shifting the steady-state inactivation curve and slowed the beating rate. CONCLUSION The G213D variant in Nav1.5 induced gating pore currents and increased window current. The changes in INa resulted in a faster beating rate and Ca2+ transient dysfunction. Flecainide decreased window current and inhibited INa, which is likely responsible for the therapeutic effectiveness of flecainide in MEPPC patients carrying the G213D variant.
Collapse
Affiliation(s)
- Kirstine Calloe
- Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlaegevej 100 DK-1870 Frederiksberg, Denmark
| | - Michelle Geryk
- Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlaegevej 100 DK-1870 Frederiksberg, Denmark
| | - Kristine Freude
- Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlaegevej 100 DK-1870 Frederiksberg, Denmark
| | - Jacqueline A Treat
- Department of Experimental Cardiology, Masonic Medical Research Institute, 2150 Bleecker Street, Utica, NY 13501, USA
| | - Victoria A Vold
- Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlaegevej 100 DK-1870 Frederiksberg, Denmark
| | - Henriette Reventlow S Frederiksen
- Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlaegevej 100 DK-1870 Frederiksberg, Denmark
| | | | - Tanja Charlotte Frederiksen
- Department of Cardiology, Aarhus University Hospital, DK-8200 Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, DK-8200 Aarhus N, Denmark
| | - Henrik K Jensen
- Department of Cardiology, Aarhus University Hospital, DK-8200 Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, DK-8200 Aarhus N, Denmark
| | - Jonathan M Cordeiro
- Department of Experimental Cardiology, Masonic Medical Research Institute, 2150 Bleecker Street, Utica, NY 13501, USA
| |
Collapse
|
9
|
Cheng J, Wei W, Fang Y, Zhou N, Wu Q, Zhao Q. Sudden cardiac death and cardiac sodium channel diseases. JOURNAL OF FORENSIC SCIENCE AND MEDICINE 2022. [DOI: 10.4103/jfsm.jfsm_123_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
|
10
|
D'Imperio S, Monasky MM, Micaglio E, Ciconte G, Anastasia L, Pappone C. Brugada Syndrome: Warning of a Systemic Condition? Front Cardiovasc Med 2021; 8:771349. [PMID: 34722688 PMCID: PMC8553994 DOI: 10.3389/fcvm.2021.771349] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 09/23/2021] [Indexed: 12/19/2022] Open
Abstract
Brugada syndrome (BrS) is a hereditary disorder, characterized by a specific electrocardiogram pattern and highly related to an increased risk of sudden cardiac death. BrS has been associated with other cardiac and non-cardiac pathologies, probably because of protein expression shared by the heart and other tissue types. In fact, the most commonly found mutated gene in BrS, SCN5A, is expressed throughout nearly the entire body. Consistent with this, large meals and alcohol consumption can trigger arrhythmic events in patients with BrS, suggesting a role for organs involved in the digestive and metabolic pathways. Ajmaline, a drug used to diagnose BrS, can have side effects on non-cardiac tissues, such as the liver, further supporting the idea of a role for organs involved in the digestive and metabolic pathways in BrS. The BrS electrocardiogram (ECG) sign has been associated with neural, digestive, and metabolic pathways, and potential biomarkers for BrS have been found in the serum or plasma. Here, we review the known associations between BrS and various organ systems, and demonstrate support for the hypothesis that BrS is not only a cardiac disorder, but rather a systemic one that affects virtually the whole body. Any time that the BrS ECG sign is found, it should be considered not a single disease, but rather the final step in any number of pathways that ultimately threaten the patient's life. A multi-omics approach would be appropriate to study this syndrome, including genetics, epigenomics, transcriptomics, proteomics, metabolomics, lipidomics, and glycomics, resulting eventually in a biomarker for BrS and the ability to diagnose this syndrome using a minimally invasive blood test, avoiding the risk associated with ajmaline testing.
Collapse
Affiliation(s)
- Sara D'Imperio
- Arrhythmology Department, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy
| | - Michelle M Monasky
- Arrhythmology Department, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy
| | - Emanuele Micaglio
- Arrhythmology Department, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy
| | - Giuseppe Ciconte
- Arrhythmology Department, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy
| | - Luigi Anastasia
- Faculty of Medicine and Surgery, University of Vita-Salute San Raffaele, Milan, Italy
| | - Carlo Pappone
- Arrhythmology Department, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy.,Faculty of Medicine and Surgery, University of Vita-Salute San Raffaele, Milan, Italy
| |
Collapse
|
11
|
Machine learning-based QSAR models to predict sodium ion channel (Na v 1.5) blockers. Future Med Chem 2020; 12:1829-1843. [PMID: 33034205 DOI: 10.4155/fmc-2020-0156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Aim: Conventional experimental approaches used for the evaluation of the proarrhythmic potential of compounds in the drug discovery process are expensive and time consuming but an integral element in the safety profile required for a new drug to be approved. The voltage-gated sodium ion channel 1.5 (Nav 1.5), a target known for arrhythmic drugs, causes adverse cardiac complications when the channel is blocked. Results: Machine learning classification and regression models were built to predict the possibility of blocking these channels by small molecules. The finalized models tested with balanced accuracies of 0.88, 0.93 and 0.94 at three thresholds (1, 10 and 30 µmol, respectively). The regression model built to predict the pIC50 of compounds had q2 of 0.84 (root-mean-square error = 0.46). Conclusion: The machine learning models that have been built can act as effective filters to screen out the potentially toxic compounds in the early stages of drug discovery.
Collapse
|
12
|
Marchal GA, Verkerk AO, Mohan RA, Wolswinkel R, Boukens BJD, Remme CA. The sodium channel Na V 1.5 impacts on early murine embryonic cardiac development, structure and function in a non-electrogenic manner. Acta Physiol (Oxf) 2020; 230:e13493. [PMID: 32386467 PMCID: PMC7539970 DOI: 10.1111/apha.13493] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/15/2020] [Accepted: 05/01/2020] [Indexed: 12/19/2022]
Abstract
AIM The voltage-gated sodium channel NaV 1.5, encoded by SCN5A, is essential for cardiac excitability and ensures proper electrical conduction. Early embryonic death has been observed in several murine models carrying homozygous Scn5amutations. We investigated when sodium current (INa ) becomes functionally relevant in the murine embryonic heart and how Scn5a/NaV 1.5 dysfunction impacts on cardiac development. METHODS Involvement of NaV 1.5-generated INa in murine cardiac electrical function was assessed by optical mapping in wild type (WT) embryos (embryonic day (E)9.5 and E10.5) in the absence and presence of the sodium channel blocker tetrodotoxin (30 µmol/L). INa was assessed by patch-clamp analysis in cardiomyocytes isolated from WT embryos (E9.5-17.5). In addition, cardiac morphology and electrical function was assessed in Scn5a-1798insD-/- embryos (E9.5-10.5) and their WT littermates. RESULTS In WT embryos, tetrodotoxin did not affect cardiac activation at E9.5, but slowed activation at E10.5. Accordingly, patch-clamp measurements revealed that INa was virtually absent at E9.5 but robustly present at E10.5. Scn5a-1798insD-/- embryos died in utero around E10.5, displaying severely affected cardiac activation and morphology. Strikingly, altered ventricular activation was observed in Scn5a-1798insD-/- E9.5 embryos before the onset of INa , in addition to reduced cardiac tissue volume compared to WT littermates. CONCLUSION We here demonstrate that NaV 1.5 is involved in cardiac electrical function from E10.5 onwards. Scn5a-1798insD-/- embryos displayed cardiac structural abnormalities at E9.5, indicating that NaV 1.5 dysfunction impacts on embryonic cardiac development in a non-electrogenic manner. These findings are potentially relevant for understanding structural defects observed in relation to NaV 1.5 dysfunction.
Collapse
Affiliation(s)
- Gerard A. Marchal
- Department of Experimental Cardiology Amsterdam UMC (location Academic Medical Center) Amsterdam the Netherlands
| | - Arie O. Verkerk
- Department of Experimental Cardiology Amsterdam UMC (location Academic Medical Center) Amsterdam the Netherlands
- Department of Medical Biology Amsterdam UMC (location Academic Medical Center) Amsterdam the Netherlands
| | - Rajiv A. Mohan
- Department of Experimental Cardiology Amsterdam UMC (location Academic Medical Center) Amsterdam the Netherlands
- Department of Medical Biology Amsterdam UMC (location Academic Medical Center) Amsterdam the Netherlands
| | - Rianne Wolswinkel
- Department of Experimental Cardiology Amsterdam UMC (location Academic Medical Center) Amsterdam the Netherlands
| | - Bastiaan J. D. Boukens
- Department of Medical Biology Amsterdam UMC (location Academic Medical Center) Amsterdam the Netherlands
| | - Carol Ann Remme
- Department of Experimental Cardiology Amsterdam UMC (location Academic Medical Center) Amsterdam the Netherlands
| |
Collapse
|
13
|
Solé L, Wagnon JL, Tamkun MM. Functional analysis of three Na v1.6 mutations causing early infantile epileptic encephalopathy. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165959. [PMID: 32916281 DOI: 10.1016/j.bbadis.2020.165959] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 08/21/2020] [Accepted: 09/03/2020] [Indexed: 11/24/2022]
Abstract
The voltage-gated sodium channel Nav1.6 is associated with more than 300 cases of epileptic encephalopathy. Nav1.6 epilepsy-causing mutations are spread over the entire channel's structure and only 10% of mutations have been characterized at the molecular level, with most of them being gain of function mutations. In this study, we analyzed three previously uncharacterized Nav1.6 epilepsy-causing mutations: G214D, N215D and V216D, located within a mutation hot-spot at the S3-S4 extracellular loop of Domain1. Voltage clamp experiments showed a 6-16 mV hyperpolarizing shift in the activation mid-point for all three mutants. V216D presented the largest shift along with decreased current amplitude, enhanced inactivation and a lack of persistent current. Recordings at hyperpolarized potentials indicated that all three mutants presented gating pore currents. Furthermore, trafficking experiments performed in cultured hippocampal neurons demonstrated that the mutants trafficked properly to the cell surface, with no significant differences regarding surface expression within the axon initial segment or soma compared to wild-type. These trafficking data suggest that the disease-causing consequences are due to only changes in the biophysical properties of the channel. Interestingly, the patient carrying the V216D mutation, which is the mutant with the greatest electrophysiological changes as compared to wild-type, exhibited the most severe phenotype. These results emphasize that these mutations will mandate unique treatment approaches, for normal sodium channel blockers may not work given that the studied mutations present gating pore currents. This study emphasizes the importance of molecular characterization of disease-causing mutations in order to improve the pharmacological treatment of patients.
Collapse
Affiliation(s)
- Laura Solé
- Molecular, Cellular and Integrative Neurosciences Graduate Program, Colorado State University, Fort Collins, CO 80523, USA; Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Jacy L Wagnon
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, USA
| | - Michael M Tamkun
- Molecular, Cellular and Integrative Neurosciences Graduate Program, Colorado State University, Fort Collins, CO 80523, USA; Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA; Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA.
| |
Collapse
|
14
|
Novel SCN5A p.V1429M Variant Segregation in a Family with Brugada Syndrome. Int J Mol Sci 2020; 21:ijms21165902. [PMID: 32824506 PMCID: PMC7460631 DOI: 10.3390/ijms21165902] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 01/10/2023] Open
Abstract
Brugada syndrome (BrS) is diagnosed by the presence of an elevated ST-segment and can result in sudden cardiac death. The most commonly found mutated gene is SCN5A, which some argue is the only gene that has been definitively confirmed to cause BrS, while the potential causative effect of other genes is still under debate. While the issue of BrS genetics is currently a hot topic, current knowledge is not able to result in molecular confirmation of over half of BrS cases. Therefore, it is difficult to develop research models with wide potential. Instead, the clinical genetics first need to be better understood. In this study, we provide crucial human data on the novel heterozygous variant NM_198056.2:c.4285G>A (p.Val1429Met) in the SCN5A gene, and demonstrate its segregation with BrS, suggesting a pathogenic effect. These results provide the first disease association with this variant and are crucial clinical data to communicate to basic scientists, who could perform functional studies to better understand the molecular effects of this clinically-relevant variant in BrS.
Collapse
|
15
|
Monasky MM, Micaglio E, Giachino D, Ciconte G, Giannelli L, Locati ET, Ramondini E, Cotugno R, Vicedomini G, Borrelli V, Ghiroldi A, Anastasia L, Pappone C. Genotype-Phenotype Correlation in a Family with Brugada Syndrome Harboring the Novel p.Gln371* Nonsense Variant in the SCN5A Gene. Int J Mol Sci 2019; 20:ijms20225522. [PMID: 31698696 PMCID: PMC6888117 DOI: 10.3390/ijms20225522] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 10/31/2019] [Accepted: 11/03/2019] [Indexed: 12/30/2022] Open
Abstract
Brugada syndrome (BrS) is marked by coved ST-segment elevation and increased risk of sudden cardiac death. The genetics of this syndrome are elusive in over half of the cases. Variants in the SCN5A gene are the single most common known genetic unifier, accounting for about a third of cases. Research models, such as animal models and cell lines, are limited. In the present study, we report the novel NM_198056.2:c.1111C>T (p.Gln371*) heterozygous variant in the SCN5A gene, as well as its segregation with BrS in a large family. The results herein suggest a pathogenic effect of this variant. Functional studies are certainly warranted to characterize the molecular effects of this variant.
Collapse
Affiliation(s)
- Michelle M. Monasky
- Arrhythmology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (M.M.M.); (E.M.); (G.C.); (L.G.); (E.T.L.); (E.R.); (R.C.); (G.V.); (V.B.)
| | - Emanuele Micaglio
- Arrhythmology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (M.M.M.); (E.M.); (G.C.); (L.G.); (E.T.L.); (E.R.); (R.C.); (G.V.); (V.B.)
| | - Daniela Giachino
- Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano (TO), Italy;
| | - Giuseppe Ciconte
- Arrhythmology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (M.M.M.); (E.M.); (G.C.); (L.G.); (E.T.L.); (E.R.); (R.C.); (G.V.); (V.B.)
| | - Luigi Giannelli
- Arrhythmology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (M.M.M.); (E.M.); (G.C.); (L.G.); (E.T.L.); (E.R.); (R.C.); (G.V.); (V.B.)
| | - Emanuela T. Locati
- Arrhythmology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (M.M.M.); (E.M.); (G.C.); (L.G.); (E.T.L.); (E.R.); (R.C.); (G.V.); (V.B.)
| | - Elisa Ramondini
- Arrhythmology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (M.M.M.); (E.M.); (G.C.); (L.G.); (E.T.L.); (E.R.); (R.C.); (G.V.); (V.B.)
| | - Roberta Cotugno
- Arrhythmology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (M.M.M.); (E.M.); (G.C.); (L.G.); (E.T.L.); (E.R.); (R.C.); (G.V.); (V.B.)
| | - Gabriele Vicedomini
- Arrhythmology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (M.M.M.); (E.M.); (G.C.); (L.G.); (E.T.L.); (E.R.); (R.C.); (G.V.); (V.B.)
| | - Valeria Borrelli
- Arrhythmology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (M.M.M.); (E.M.); (G.C.); (L.G.); (E.T.L.); (E.R.); (R.C.); (G.V.); (V.B.)
| | - Andrea Ghiroldi
- Stem Cells for Tissue Engineering Laboratory, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (A.G.); (L.A.)
| | - Luigi Anastasia
- Stem Cells for Tissue Engineering Laboratory, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (A.G.); (L.A.)
- Department of Biomedical Sciences for Health, University of Milan, 20133 Milan, Italy
| | - Carlo Pappone
- Arrhythmology Department, IRCCS Policlinico San Donato, 20097 San Donato Milanese (MI), Italy; (M.M.M.); (E.M.); (G.C.); (L.G.); (E.T.L.); (E.R.); (R.C.); (G.V.); (V.B.)
- Correspondence: ; Tel./Fax: +39-0252774260/4306
| |
Collapse
|
16
|
Micaglio E, Monasky MM, Resta N, Bagnulo R, Ciconte G, Gianelli L, Locati ET, Vicedomini G, Borrelli V, Ghiroldi A, Anastasia L, Benedetti S, Di Resta C, Ferrari M, Pappone C. Novel SCN5A p.W697X Nonsense Mutation Segregation in a Family with Brugada Syndrome. Int J Mol Sci 2019; 20:ijms20194920. [PMID: 31590245 PMCID: PMC6801452 DOI: 10.3390/ijms20194920] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 09/25/2019] [Accepted: 09/26/2019] [Indexed: 01/05/2023] Open
Abstract
Brugada syndrome (BrS) is marked by an elevated ST-segment elevation and increased risk of sudden cardiac death. Variants in the SCN5A gene are considered to be molecular confirmation of the syndrome in about one third of cases, while the genetics remain a mystery in about half of the cases, with the remaining cases being attributed to variants in any of a number of genes. Before research models can be developed, it is imperative to understand the genetics in patients. Even data from humans is complicated, since variants in the most common gene in BrS, SCN5A, are associated with a number of pathologies, or could even be considered benign, depending on the variant. Here, we provide crucial human data on a novel NM_198056.2:c.2091G>A (p.Trp697X) point-nonsense heterozygous variant in the SCN5A gene, as well as its segregation with BrS. The results herein suggest a pathogenic effect of this variant. These results could be used as a stepping stone for functional studies to better understand the molecular effects of this variant in BrS.
Collapse
Affiliation(s)
- Emanuele Micaglio
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy (M.M.M.); (G.C.); (L.G.); (E.T.L.); (G.V.); (V.B.)
| | - Michelle M. Monasky
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy (M.M.M.); (G.C.); (L.G.); (E.T.L.); (G.V.); (V.B.)
| | - Nicoletta Resta
- Medical Genetics Unit, Department of Biomedical Sciences and Human Oncology, “Aldo Moro” University of Bari, Policlinico Hospital, 70121 Bari, Italy; (N.R.); (R.B.)
| | - Rosanna Bagnulo
- Medical Genetics Unit, Department of Biomedical Sciences and Human Oncology, “Aldo Moro” University of Bari, Policlinico Hospital, 70121 Bari, Italy; (N.R.); (R.B.)
| | - Giuseppe Ciconte
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy (M.M.M.); (G.C.); (L.G.); (E.T.L.); (G.V.); (V.B.)
| | - Luigi Gianelli
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy (M.M.M.); (G.C.); (L.G.); (E.T.L.); (G.V.); (V.B.)
| | - Emanuela T. Locati
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy (M.M.M.); (G.C.); (L.G.); (E.T.L.); (G.V.); (V.B.)
| | - Gabriele Vicedomini
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy (M.M.M.); (G.C.); (L.G.); (E.T.L.); (G.V.); (V.B.)
| | - Valeria Borrelli
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy (M.M.M.); (G.C.); (L.G.); (E.T.L.); (G.V.); (V.B.)
| | - Andrea Ghiroldi
- Stem Cells for Tissue Engineering Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy; (A.G.); (L.A.)
| | - Luigi Anastasia
- Stem Cells for Tissue Engineering Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy; (A.G.); (L.A.)
- Department of Biomedical Sciences for Health, University of Milan, 20122 Milan, Italy
| | - Sara Benedetti
- Laboratory of Clinical Molecular Biology and Cytogenetics, Division of Genetics and Cellular Biology, IRCCS San Raffaele Hospital, 20132 Milan, Italy; (S.B.); (M.F.)
| | - Chiara Di Resta
- Genomic Unit for the Diagnosis of Human Pathologies, Division of Genetics and Cellular Biology, IRCCS San Raffaele Hospital, 20132 Milan, Italy;
- Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Maurizio Ferrari
- Laboratory of Clinical Molecular Biology and Cytogenetics, Division of Genetics and Cellular Biology, IRCCS San Raffaele Hospital, 20132 Milan, Italy; (S.B.); (M.F.)
- Genomic Unit for the Diagnosis of Human Pathologies, Division of Genetics and Cellular Biology, IRCCS San Raffaele Hospital, 20132 Milan, Italy;
- Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Carlo Pappone
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy (M.M.M.); (G.C.); (L.G.); (E.T.L.); (G.V.); (V.B.)
- Correspondence: ; Tel.: +39-0252774260
| |
Collapse
|
17
|
Monasky MM, Micaglio E, Ciconte G, Benedetti S, Di Resta C, Vicedomini G, Borrelli V, Ghiroldi A, Piccoli M, Anastasia L, Santinelli V, Ferrari M, Pappone C. Genotype/Phenotype Relationship in a Consanguineal Family With Brugada Syndrome Harboring the R1632C Missense Variant in the SCN5A Gene. Front Physiol 2019; 10:666. [PMID: 31191357 PMCID: PMC6546918 DOI: 10.3389/fphys.2019.00666] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 05/09/2019] [Indexed: 12/19/2022] Open
Abstract
Brugada syndrome (BrS) is a known cause of sudden cardiac death. The genetic basis of BrS is not well understood, and no one single gene is linked to even a majority of BrS cases. However, mutations in the gene SCN5A are the most common, although the high amount of phenotypic variability prevents a clear correlation between genotype and phenotype. Research techniques are limited, as most BrS cases still remain without a genetic diagnosis, thus impairing the implementation of experimental models representative of a general pathogenetic mechanism. In the present study, we report the largest family to-date with the segregation of the heterozygous variant NM_198056:c.4894C>T (p.Arg1632Cys) in the SCN5A gene. The genotype-phenotype relationship observed suggests a likely pathogenic effect of this variant. Functional studies to better understand the molecular effects of this variant are warranted.
Collapse
Affiliation(s)
- Michelle M Monasky
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Emanuele Micaglio
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Giuseppe Ciconte
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Sara Benedetti
- Laboratory of Clinical Molecular Biology and Cytogenetics, IRCCS San Raffaele Hospital, Milan, Italy
| | - Chiara Di Resta
- Genomic Unit for the Diagnosis of Human Pathologies, Division of Genetics and Cellular Biology, IRCCS San Raffaele Hospital, Milan, Italy.,Vita-Salute San Raffaele University, Milan, Italy
| | - Gabriele Vicedomini
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Valeria Borrelli
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Andrea Ghiroldi
- Stem Cells for Tissue Engineering Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Marco Piccoli
- Stem Cells for Tissue Engineering Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Luigi Anastasia
- Stem Cells for Tissue Engineering Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy.,Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Vincenzo Santinelli
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Maurizio Ferrari
- Laboratory of Clinical Molecular Biology and Cytogenetics, IRCCS San Raffaele Hospital, Milan, Italy.,Genomic Unit for the Diagnosis of Human Pathologies, Division of Genetics and Cellular Biology, IRCCS San Raffaele Hospital, Milan, Italy.,Vita-Salute San Raffaele University, Milan, Italy
| | - Carlo Pappone
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy
| |
Collapse
|
18
|
Reduced hybrid/complex N-glycosylation disrupts cardiac electrical signaling and calcium handling in a model of dilated cardiomyopathy. J Mol Cell Cardiol 2019; 132:13-23. [PMID: 31071333 DOI: 10.1016/j.yjmcc.2019.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/12/2019] [Accepted: 05/01/2019] [Indexed: 12/19/2022]
Abstract
Dilated cardiomyopathy (DCM) is the third most common cause of heart failure, with ~70% of DCM cases considered idiopathic. We showed recently, through genetic ablation of the MGAT1 gene, which encodes an essential glycosyltransferase (GlcNAcT1), that prevention of cardiomyocyte hybrid/complex N-glycosylation was sufficient to cause DCM that led to heart failure and early death. Our findings are consistent with increasing evidence suggesting a link between aberrant glycosylation and heart diseases of acquired and congenital etiologies. However, the mechanisms by which changes in glycosylation contribute to disease onset and progression remain largely unknown. Activity and gating of voltage-gated Na+ and K+ channels (Nav and Kv respectively) play pivotal roles in the initiation, shaping and conduction of cardiomyocyte action potentials (APs) and aberrant channel activity was shown to contribute to cardiac disease. We and others showed that glycosylation can impact Nav and Kv function; therefore, here, we investigated the effects of reduced cardiomyocyte hybrid/complex N-glycosylation on channel activity to investigate whether chronic aberrant channel function can contribute to DCM. Ventricular cardiomyocytes from MGAT1 deficient (MGAT1KO) mice display prolonged APs and pacing-induced aberrant early re-activation that can be attributed to, at least in part, a significant reduction in Kv expression and activity that worsens over time suggesting heart disease-related remodeling. MGAT1KO Nav demonstrate no change in expression or maximal conductance but show depolarizing shifts in voltage-dependent gating. Together, the changes in MGAT1KO Nav and Kv function likely contribute to observed anomalous electrocardiograms and Ca2+ handling. These findings provide insight into mechanisms by which altered glycosylation contributes to DCM through changes in Nav and Kv activity that impact conduction, Ca2+ handling and contraction. The MGAT1KO can also serve as a useful model to study the effects of aberrant electrical signaling on cardiac function and the remodeling events that can occur with heart disease progression.
Collapse
|
19
|
Nastou KC, Batskinis MA, Litou ZI, Hamodrakas SJ, Iconomidou VA. Analysis of Single-Nucleotide Polymorphisms in Human Voltage-Gated Ion Channels. J Proteome Res 2019; 18:2310-2320. [DOI: 10.1021/acs.jproteome.9b00121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Katerina C. Nastou
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15701, Greece
| | - Michail A. Batskinis
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15701, Greece
| | - Zoi I. Litou
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15701, Greece
| | - Stavros J. Hamodrakas
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15701, Greece
| | - Vassiliki A. Iconomidou
- Section of Cell Biology and Biophysics, Department of Biology, School of Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15701, Greece
| |
Collapse
|
20
|
A leaky voltage sensor domain of cardiac sodium channels causes arrhythmias associated with dilated cardiomyopathy. Sci Rep 2018; 8:13804. [PMID: 30218094 PMCID: PMC6138662 DOI: 10.1038/s41598-018-31772-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 08/21/2018] [Indexed: 11/18/2022] Open
Abstract
Dilated cardiomyopathy (DCM) is a structural heart disease that causes dilatation of cardiac chambers and impairs cardiac contractility. The SCN5A gene encodes Nav1.5, the predominant cardiac sodium channel alpha subunit. SCN5A mutations have been identified in patients with arrhythmic disorders associated with DCM. The characterization of Nav1.5 mutations located in the voltage sensor domain (VSD) and associated with DCM revealed divergent biophysical defects that do not fully explain the pathologies observed in these patients. The purpose of this study was to characterize the pathological consequences of a gating pore in the heart arising from the Nav1.5/R219H mutation in a patient with complex cardiac arrhythmias and DCM. We report its properties using cardiomyocytes derived from patient-specific human induced pluripotent stem cells. We showed that this mutation generates a proton leak (called gating pore current). We also described disrupted ionic homeostasis, altered cellular morphology, electrical properties, and contractile function, most probably linked to the proton leak. We thus propose a novel link between SCN5A mutation and the complex pathogenesis of cardiac arrhythmias and DCM. Furthermore, we suggest that leaky channels would constitute a common pathological mechanism underlying several neuronal, neuromuscular, and cardiac pathologies.
Collapse
|
21
|
Monasky MM, Pappone C, Piccoli M, Ghiroldi A, Micaglio E, Anastasia L. Calcium in Brugada Syndrome: Questions for Future Research. Front Physiol 2018; 9:1088. [PMID: 30147658 PMCID: PMC6095984 DOI: 10.3389/fphys.2018.01088] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/23/2018] [Indexed: 12/11/2022] Open
Abstract
The Brugada syndrome (BrS) is characterized by coved-type ST-segment elevation in the right precordial leads on the electrocardiogram (ECG) and increased risk of sudden cardiac death (SCD). While it is an inheritable disease, determining the true prevalence is a challenge, since patients may report no known family history of the syndrome, present with a normal spontaneous ECG pattern at the time of examination, and test negative for all known BrS-causative genes. In fact, SCD is often the first indication that a person is affected by the syndrome. Men are more likely to be symptomatic than women. Abnormal, low-voltage, fractionated electrograms have been found in the epicardium of the right ventricular outflow tract (RVOT). Ablation of this area abolishes the abnormal electrograms and helps to prevent arrhythmic recurrences. BrS patients are more likely to experience ventricular tachycardia/fibrillation (VT/VF) during fever or during an increase in vagal tone. Isoproterenol helps to reverse the ECG BrS phenotype. In this review, we discuss roles of calcium in various conditions that are relevant to BrS, such as changes in temperature, heart rate, and vagal tone, and the effects of gender and isoproterenol on calcium handling. Studies are warranted to further investigate these mechanisms in models of BrS.
Collapse
Affiliation(s)
| | - Carlo Pappone
- Arrhythmology Department, IRCCS Policlinico San Donato, Milan, Italy
| | - Marco Piccoli
- Stem Cells for Tissue Engineering Lab, IRCCS Policlinico San Donato, Milan, Italy
| | - Andrea Ghiroldi
- Stem Cells for Tissue Engineering Lab, IRCCS Policlinico San Donato, Milan, Italy
| | - Emanuele Micaglio
- Arrhythmology Department, IRCCS Policlinico San Donato, Milan, Italy
| | - Luigi Anastasia
- Stem Cells for Tissue Engineering Lab, IRCCS Policlinico San Donato, Milan, Italy.,Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| |
Collapse
|
22
|
Abstract
Voltage-gated sodium channels belong to the superfamily of voltage-gated cation channels. Their structure is based on domains comprising a voltage sensor domain (S1-S4 segments) and a pore domain (S5-S6 segments). Mutations in positively charged residues of the S4 segments may allow protons or cations to pass directly through the gating pore constriction of the voltage sensor domain; these anomalous currents are referred to as gating pore or omega (ω) currents. In the skeletal muscle disorder hypokalemic periodic paralysis, and in arrhythmic dilated cardiomyopathy, inherited mutations of S4 arginine residues promote omega currents that have been shown to be a contributing factor in the pathogenesis of these sodium channel disorders. Characterization of gating pore currents in these channelopathies and with artificial mutations has been possible by measuring the voltage-dependence and selectivity of these leak currents. The basis of gating pore currents and the structural basis of S4 movement through the gating pore has also been studied extensively with molecular dynamics. These simulations have provided valuable insight into the nature of S4 translocation and the physical basis for the effects of mutations that promote permeation of protons or cations through the gating pore.
Collapse
Affiliation(s)
- J R Groome
- Department of Biological Sciences, Idaho State University, Pocatello, ID, 83209, USA.
| | - A Moreau
- Institut NeuroMyogene, ENS de Lyon, Site MONOD, Lyon, France
| | - L Delemotte
- Science for Life Laboratory, Department of Physics, KTH Royal Institute of Technology, Box 1031, 171 21, Solna, Sweden
| |
Collapse
|
23
|
Genetic basis of dilated cardiomyopathy. Int J Cardiol 2016; 224:461-472. [PMID: 27736720 DOI: 10.1016/j.ijcard.2016.09.068] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 09/15/2016] [Accepted: 09/17/2016] [Indexed: 01/19/2023]
|
24
|
Priganc M, Zigová M, Boroňová I, Bernasovská J, Dojčáková D, Szabadosová V, Mydlárová Blaščáková M, Tóthová I, Kmec J, Bernasovský I. Analysis of SCN5A Gene Variants in East Slovak Patients with Cardiomyopathy. J Clin Lab Anal 2016; 31. [PMID: 27554632 DOI: 10.1002/jcla.22037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/13/2016] [Indexed: 01/23/2023] Open
Abstract
OBJECTIVE Mutations in ion channels genes are potential cause of cardiomyopathy. The SCN5A gene (sodium channel, voltage gated, type V alpha subunit gene; 3p21) belongs to the family of cardiac sodium channel genes. Mutations in SCN5A gene lead to decreased Na+ current and ion unbalance. The SCN5A gene mutations are found in approximately 2% of patients with dilated cardiomyopathy (DCM), and they may be potential phenotype modifiers in hypertrophic cardiomyopathy (HCM). The role of SCN5A gene mutations in cardiomyopathy is not fully elucidated. METHODS Three selected exons (12, 20, and 21) of the SCN5A gene in the cohort of 58 East Slovak patients with dilated and HCM were analyzed by the Sanger sequencing method in order to detect etiopathogenic mutations associated with dilated and HCM. RESULTS The mutation screening of three selected exons of SCN5A gene in the cohort of 27 DCM, 12 HCM patients, and 16 controls identified 10 missense genetic variants. Three of them (T1247I, A1260D, and G1262S), all in exon 21 of the SCN5A gene, were potentially damaging and disease-causing variants. CONCLUSION Data from this study demonstrate that SCN5A gene variants have important role in the etiopathogenesis of dilated and HCM.
Collapse
Affiliation(s)
- Mariana Priganc
- Department of Biology, Faculty of Humanities and Natural Sciences, University of Prešov, Prešov, Slovak Republic
| | - Michaela Zigová
- Department of Biology, Faculty of Humanities and Natural Sciences, University of Prešov, Prešov, Slovak Republic
| | - Iveta Boroňová
- Department of Biology, Faculty of Humanities and Natural Sciences, University of Prešov, Prešov, Slovak Republic
| | - Jarmila Bernasovská
- Department of Biology, Faculty of Humanities and Natural Sciences, University of Prešov, Prešov, Slovak Republic
| | - Dana Dojčáková
- Department of Biology, Faculty of Humanities and Natural Sciences, University of Prešov, Prešov, Slovak Republic
| | - Viktória Szabadosová
- Department of Biology, Faculty of Humanities and Natural Sciences, University of Prešov, Prešov, Slovak Republic
| | - Marta Mydlárová Blaščáková
- Department of Biology, Faculty of Humanities and Natural Sciences, University of Prešov, Prešov, Slovak Republic
| | - Iveta Tóthová
- Department of Biology, Faculty of Humanities and Natural Sciences, University of Prešov, Prešov, Slovak Republic
| | - Ján Kmec
- Cardiocentre, Faculty Hospital of J.A. Rayman, Prešov, Slovak Republic.,Department of Urgent Health Care, Faculty of Health Care, University of Prešov, Prešov, Slovak Republic
| | - Ivan Bernasovský
- Center of Languages and Cultures of National Minorities, University of Prešov, Prešov, Slovak Republic
| |
Collapse
|
25
|
Moreau A, Gosselin-Badaroudine P, Chahine M. Gating pore currents, a new pathological mechanism underlying cardiac arrhythmias associated with dilated cardiomyopathy. Channels (Austin) 2016; 9:139-44. [PMID: 26046592 PMCID: PMC4594536 DOI: 10.1080/19336950.2015.1031937] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Voltage-gated ion channels (VGIC) are transmembrane proteins responsible for the generation of electrical signals in excitable cells. VGIC were first described in 1952 by Hodgkin and Huxley,1 and have since been associated with various physiological functions such as propagating nerve impulses, locomotion, and cardiac excitability. VGIC include channels specialized in the selective passage of K+, Ca2+ Na+, or H+. They are composed of 2 main structures: the pore domain (PD) and the voltage sensor domain (VSD). The PD ensures the physiological flow of ions and is typically composed of 8 transmembrane segments (TM). The VSD detects voltage variations and is composed of 4 TM (S1-S4). Given their crucial physiological role, VGIC dysfunctions are associated with diverse pathologies known as ion channelopathies. These dysfunctions usually affect the membrane expression of ion channels or voltage-dependent conformational changes of the pore. However, an increasing number of ion channelopathies, including periodic paralysis, dilated cardiomyopathy (DCM) associated with cardiac arrhythmias, and peripheral nerve hyperexcitability (PNH), have been linked to the appearance of a new pathological mechanism involving the creation of an alternative permeation pathway through the normally non-conductive VSD of VGIC. This permeation pathway is called the gating pore or omega pore.
Collapse
Affiliation(s)
- Adrien Moreau
- a Centre de Recherche ; Institut Universitaire en Santé Mentale de Québec ; Quebec City , QC Canada
| | | | | |
Collapse
|
26
|
Zaklyazminskaya E, Dzemeshkevich S. The role of mutations in the SCN5A gene in cardiomyopathies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1799-805. [PMID: 26916278 DOI: 10.1016/j.bbamcr.2016.02.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Revised: 02/17/2016] [Accepted: 02/19/2016] [Indexed: 12/18/2022]
Abstract
The SCN5A gene encodes the alpha-subunit of the Nav1.5 ion channel protein, which is responsible for the sodium inward current (INa). Since 1995 several hundred mutations in this gene have been found to be causative for inherited arrhythmias including Long QT syndrome, Brugada syndrome, cardiac conduction disease, sudden infant death syndrome, etc. As expected these syndromes are primarily electrical heart diseases leading to life-threatening arrhythmias with an "apparently normal heart". In 2003 a new form of dilated cardiomyopathy was identified associated with mutations in the SCN5A gene. Recently mutations have been also found in patients with arrhythmogenic right ventricular cardiomyopathy and atrial standstill. The purpose of this review is to outline and analyze the following four topics: 1) SCN5A genetic variants linked to different cardiomyopathies; 2) clinical manifestations of the known mutations; 3) possible molecular mechanisms of myocardial remodeling; and 4) the potential implications of gene-specific treatment for those disorders. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
Collapse
Affiliation(s)
- Elena Zaklyazminskaya
- Petrovsky Russian Research Centre of Surgery, Abricosovsky pereulok, 119991 Moscow, Russia; Department of Molecular and Cellular Genetics, Pirogov Russian National Research Medical University, Ostrovityanova str. 1, Moscow 117997, Russia.
| | - Sergei Dzemeshkevich
- Petrovsky Russian Research Centre of Surgery, Abricosovsky pereulok, 119991 Moscow, Russia.
| |
Collapse
|
27
|
Held K, Voets T, Vriens J. Signature and Pathophysiology of Non-canonical Pores in Voltage-Dependent Cation Channels. Rev Physiol Biochem Pharmacol 2016; 170:67-99. [DOI: 10.1007/112_2015_5003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
28
|
Moreau A, Gosselin-Badaroudine P, Boutjdir M, Chahine M. Mutations in the Voltage Sensors of Domains I and II of Nav1.5 that are Associated with Arrhythmias and Dilated Cardiomyopathy Generate Gating Pore Currents. Front Pharmacol 2015; 6:301. [PMID: 26733869 PMCID: PMC4689871 DOI: 10.3389/fphar.2015.00301] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 12/09/2015] [Indexed: 12/19/2022] Open
Abstract
Voltage gated sodium channels (Nav) are transmembrane proteins responsible for action potential initiation. Mutations mainly located in the voltage sensor domain (VSD) of Nav1.5, the cardiac sodium channel, have been associated with the development of arrhythmias combined with dilated cardiomyopathy. Gating pore currents have been observed with three unrelated mutations associated with similar clinical phenotypes. However, gating pores have never been associated with mutations outside the first domain of Nav1.5. The aim of this study was to explore the possibility that gating pore currents might be caused by the Nav1.5 R225P and R814W mutations (R3, S4 in DI and DII, respectively), which are associated with rhythm disturbances and dilated cardiomyopathy. Nav1.5 WT and mutant channels were transiently expressed in tsA201 cells. The biophysical properties of the alpha pore currents and the presence of gating pore currents were investigated using the patch-clamp technique. We confirmed the previously reported gain of function of the alpha pores of the mutant channels, which mainly consisted of increased window currents mostly caused by shifts in the voltage dependence of activation. We also observed gating pore currents associated with the R225P and R814W mutations. This novel permeation pathway was open under depolarized conditions and remained temporarily open at hyperpolarized potentials after depolarization periods. Gating pore currents could represent a molecular basis for the development of uncommon electrical abnormalities and changes in cardiac morphology. We propose that this biophysical defect be routinely evaluated in the case of Nav1.5 mutations on the VSD.
Collapse
Affiliation(s)
- Adrien Moreau
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec City QC, Canada
| | | | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn NY, USA
| | - Mohamed Chahine
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec CityQC, Canada; Department of Medicine, Université Laval, Quebec CityQC, Canada
| |
Collapse
|
29
|
Abstract
The zebrafish (Danio rerio) has become a popular model for human cardiac diseases and pharmacology including cardiac arrhythmias and its electrophysiological basis. Notably, the phenotype of zebrafish cardiac action potential is similar to the human cardiac action potential in that both have a long plateau phase. Also the major inward and outward current systems are qualitatively similar in zebrafish and human hearts. However, there are also significant differences in ionic current composition between human and zebrafish hearts, and the molecular basis and pharmacological properties of human and zebrafish cardiac ionic currents differ in several ways. Cardiac ionic currents may be produced by non-orthologous genes in zebrafish and humans, and paralogous gene products of some ion channels are expressed in the zebrafish heart. More research on molecular basis of cardiac ion channels, and regulation and drug sensitivity of the cardiac ionic currents are needed to enable rational use of the zebrafish heart as an electrophysiological model for the human heart.
Collapse
Affiliation(s)
- Matti Vornanen
- a Department of Biology , University of Eastern Finland , Joensuu , Finland
| | - Minna Hassinen
- a Department of Biology , University of Eastern Finland , Joensuu , Finland
| |
Collapse
|
30
|
Moreau A, Gosselin-Badaroudine P, Delemotte L, Klein ML, Chahine M. Gating pore currents are defects in common with two Nav1.5 mutations in patients with mixed arrhythmias and dilated cardiomyopathy. ACTA ACUST UNITED AC 2015; 145:93-106. [PMID: 25624448 PMCID: PMC4306709 DOI: 10.1085/jgp.201411304] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nav1.5 channels bearing voltage-sensor domain mutations associated with atypical cardiac arrhythmias and dilated cardiomyopathy generate gating pore currents. The gating pore current, also called omega current, consists of a cation leak through the typically nonconductive voltage-sensor domain (VSD) of voltage-gated ion channels. Although the study of gating pore currents has refined our knowledge of the structure and the function of voltage-gated ion channels, their implication in cardiac disorders has not been established. Two Nav1.5 mutations (R222Q and R225W) located in the VSD are associated with atypical clinical phenotypes involving complex arrhythmias and dilated cardiomyopathy. Using the patch-clamp technique, in silico mutagenesis, and molecular dynamic simulations, we tested the hypothesis that these two mutations may generate gating pore currents, potentially accounting for their clinical phenotypes. Our findings suggest that the gating pore current generated by the R222Q and R225W mutations could constitute the underlying pathological mechanism that links Nav1.5 VSD mutations with human cardiac arrhythmias and dilatation of cardiac chambers.
Collapse
Affiliation(s)
- Adrien Moreau
- Centre de Recherche de L'Institut Universitaire en Santé Mentale de Québec, Québec City, Québec G1J 2G3, Canada
| | - Pascal Gosselin-Badaroudine
- Centre de Recherche de L'Institut Universitaire en Santé Mentale de Québec, Québec City, Québec G1J 2G3, Canada
| | - Lucie Delemotte
- Institute of Computational Molecular Science, Temple University, Philadelphia, PA 19122
| | - Michael L Klein
- Institute of Computational Molecular Science, Temple University, Philadelphia, PA 19122
| | - Mohamed Chahine
- Centre de Recherche de L'Institut Universitaire en Santé Mentale de Québec, Québec City, Québec G1J 2G3, Canada Department of Medicine, Université Laval, Québec City, Québec G1K 7P4, Canada
| |
Collapse
|
31
|
Moreau A, Chahine M. [Omega pore, an alternative ion channel permeation pathway involved in the development of several channelopathies]. Med Sci (Paris) 2015; 31:735-41. [PMID: 26340832 DOI: 10.1051/medsci/20153108011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Voltage gated ion channels (VGIC) constitute a large family of ion channels. VGIC are responsible for ions to cross the membrane. They are composed of a pore domain associated to voltage sensor domains (VSD), which regulate the function of the pore. The VSD has been recognized as the unit responsible for sensing electrical signals of all VGIC. Recently, mutations within the VSD have been studied and revealed the creation of a new permeation pathway directly through the usually non-conductive VSD. This new permeation pathway has been called omega pore or gating pore. Given the number, the diversity and the large roles of VSD, gating pores might become an important pathological defect. Indeed, several mutations have been associated to the development of several pathologies such as periodic paralysis, arrhythmias and cardiac dilatation or also the peripheral nerve hyperexcitability.
Collapse
Affiliation(s)
- Adrien Moreau
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, 2601 chemin de la Canardière, Québec, QC, G1J 2G3 Canada
| | - Mohamed Chahine
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, 2601 chemin de la Canardière, Québec, QC, G1J 2G3 Canada - Département de médecine, université Laval, Québec, QC, G1K 7P4 Canada
| |
Collapse
|
32
|
Chahine M. Gating pore current is a novel biophysical defect of Nav1.5 mutations associated with unusual cardiac arrhythmias and dilation. Future Cardiol 2015; 11:287-91. [PMID: 26021634 DOI: 10.2217/fca.15.23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
33
|
Moreau A, Gosselin-Badaroudine P, Chahine M. Biophysics, pathophysiology, and pharmacology of ion channel gating pores. Front Pharmacol 2014; 5:53. [PMID: 24772081 PMCID: PMC3982104 DOI: 10.3389/fphar.2014.00053] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 03/12/2014] [Indexed: 12/19/2022] Open
Abstract
Voltage sensor domains (VSDs) are a feature of voltage gated ion channels (VGICs) and voltage sensitive proteins. They are composed of four transmembrane (TM) segments (S1–S4). Currents leaking through VSDs are called omega or gating pore currents. Gating pores are caused by mutations of the highly conserved positively charged amino acids in the S4 segment that disrupt interactions between the S4 segment and the gating charge transfer center (GCTC). The GCTC separates the intracellular and extracellular water crevices. The disruption of S4–GCTC interactions allows these crevices to communicate and create a fast activating and non-inactivating alternative cation-selective permeation pathway of low conductance, or a gating pore. Gating pore currents have recently been shown to cause periodic paralysis phenotypes. There is also increasing evidence that gating pores are linked to several other familial diseases. For example, gating pores in Nav1.5 and Kv7.2 channels may underlie mixed arrhythmias associated with dilated cardiomyopathy (DCM) phenotypes and peripheral nerve hyperexcitability (PNH), respectively. There is little evidence for the existence of gating pore blockers. Moreover, it is known that a number of toxins bind to the VSD of a specific domain of Na+ channels. These toxins may thus modulate gating pore currents. This focus on the VSD motif opens up a new area of research centered on developing molecules to treat a number of cell excitability disorders such as epilepsy, cardiac arrhythmias, and pain. The purpose of the present review is to summarize existing knowledge of the pathophysiology, biophysics, and pharmacology of gating pore currents and to serve as a guide for future studies aimed at improving our understanding of gating pores and their pathophysiological roles.
Collapse
Affiliation(s)
- Adrien Moreau
- Centre de Recherche de L'Institut Universitaire en Santé Mentale de Québec Quebec City, QC, Canada
| | | | - Mohamed Chahine
- Centre de Recherche de L'Institut Universitaire en Santé Mentale de Québec Quebec City, QC, Canada ; Department of Medicine, Université Laval Quebec City, QC, Canada
| |
Collapse
|