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Elhanafy E, Ahangar AA, Roth R, Gamal El-Din TM, Bankston JR, Li J. ELUCIDATING THE DIFFERENTIAL IMPACTS OF EQUIVALENT GATING-CHARGE MUTATIONS IN VOLTAGE-GATED SODIUM CHANNELS. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.09.612021. [PMID: 39314455 PMCID: PMC11419121 DOI: 10.1101/2024.09.09.612021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Voltage-gated sodium (Nav) channels are pivotal for cellular signaling and mutations in Nav channels can lead to excitability disorders in cardiac, muscular, and neural tissues. A major cluster of pathological mutations localizes in the voltage-sensing domains (VSDs), resulting in either gain-of-function (GoF), loss-of-function (LoF) effects, or both. However, the mechanism behind this functional divergence of mutations at equivalent positions remains elusive. Through hotspot analysis, we identified three gating charges (R1, R2, and R3) as major mutational hotspots in VSDs. The same amino-acid substitutions at equivalent gating-charge positions in VSDI and VSDII of the cardiac sodium channel Nav1.5 show differential gating-property impacts in electrophysiology measurements. We conducted 120 μs molecular dynamics (MD) simulations on wild-type and six mutants to elucidate the structural basis of their differential impacts. Our μs-scale MD simulations with applied external electric fields captured VSD state transitions and revealed the differential structural dynamics between equivalent R-to-Q mutants. Notably, we observed transient leaky conformations in some mutants during structural transitions, offering a detailed structural explanation for gating-pore currents. Our salt-bridge network analysis uncovered VSD-specific and state-dependent interactions among gating charges, countercharges, and lipids. This detailed analysis elucidated how mutations disrupt critical electrostatic interactions, thereby altering VSD permeability and modulating gating properties. By demonstrating the crucial importance of considering the specific structural context of each mutation, our study represents a significant leap forward in understanding structure-function relationships in Nav channels. Our work establishes a robust framework for future investigations into the molecular basis of ion channel-related disorders.
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Affiliation(s)
- Eslam Elhanafy
- Department of Biomolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS
| | - Amin Akbari Ahangar
- Department of Biomolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS
| | - Rebecca Roth
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | | | - John R Bankston
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Jing Li
- Department of Biomolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS
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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.
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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
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Eltokhi A, Lundstrom BN, Li J, Zweifel LS, Catterall WA, Gamal El-Din TM. Pathogenic gating pore current conducted by autism-related mutations in the Na V1.2 brain sodium channel. Proc Natl Acad Sci U S A 2024; 121:e2317769121. [PMID: 38564633 PMCID: PMC11009634 DOI: 10.1073/pnas.2317769121] [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: 10/23/2023] [Accepted: 02/26/2024] [Indexed: 04/04/2024] Open
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by social and communication deficits and repetitive behaviors. The genetic heterogeneity of ASD presents a challenge to the development of an effective treatment targeting the underlying molecular defects. ASD gating charge mutations in the KCNQ/KV7 potassium channel cause gating pore currents (Igp) and impair action potential (AP) firing of dopaminergic neurons in brain slices. Here, we investigated ASD gating charge mutations of the voltage-gated SCN2A/NaV1.2 brain sodium channel, which ranked high among the ion channel genes with mutations in individuals with ASD. Our results show that ASD mutations in the gating charges R2 in Domain-II (R853Q), and R1 (R1626Q) and R2 (R1629H) in Domain-IV of NaV1.2 caused Igp in the resting state of ~0.1% of the amplitude of central pore current. The R1626Q mutant also caused significant changes in the voltage dependence of fast inactivation, and the R1629H mutant conducted proton-selective Igp. These potentially pathogenic Igp were exacerbated by the absence of the extracellular Mg2+ and Ca2+. In silico simulation of the effects of these mutations in a conductance-based single-compartment cortical neuron model suggests that the inward Igp reduces the time to peak for the first AP in a train, increases AP rates during a train of stimuli, and reduces the interstimulus interval between consecutive APs, consistent with increased neural excitability and altered input/output relationships. Understanding this common pathophysiological mechanism among different voltage-gated ion channels at the circuit level will give insights into the underlying mechanisms of ASD.
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Affiliation(s)
- Ahmed Eltokhi
- Department of Pharmacology, University of Washington, Seattle, WA98195
| | - Brian Nils Lundstrom
- Department of Neurology in the Division of Epilepsy, Mayo Clinic, Rochester, MN55905
| | - Jin Li
- Department of Pharmacology, University of Washington, Seattle, WA98195
| | - Larry S. Zweifel
- Department of Pharmacology, University of Washington, Seattle, WA98195
- Department of Psychiatry & Behavioral Sciences, University of Washington, Seattle, WA98195
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Glazer AM, Yang T, Li B, Page D, Fouda M, Wada Y, Lancaster MC, O’Neill MJ, Muhammad A, Gao X, Ackerman MJ, Sanatani S, Ruben PC, Roden DM. Multifocal Ectopic Purkinje Premature Contractions due to neutralization of an SCN5A negative charge: structural insights into the gating pore hypothesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.580021. [PMID: 38405820 PMCID: PMC10888965 DOI: 10.1101/2024.02.13.580021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Background We identified a novel SCN5A variant, E171Q, in a neonate with very frequent ectopy and reduced ejection fraction which normalized after arrhythmia suppression by flecainide. This clinical picture is consistent with multifocal ectopic Purkinje-related premature contractions (MEPPC). Most previous reports of MEPPC have implicated SCN5A variants such as R222Q that neutralize positive charges in the S4 voltage sensor helix of the channel protein NaV1.5 and generate a gating pore current. Methods and Results E171 is a highly conserved negatively-charged residue located in the S2 transmembrane helix of NaV1.5 domain I. E171 is a key component of the Gating Charge Transfer Center, a region thought to be critical for normal movement of the S4 voltage sensor helix. We used heterologous expression, CRISPR-edited induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), and molecular dynamics simulations to demonstrate that E171Q generates a gating pore current, which was suppressed by a low concentration of flecainide (IC50 = 0.71±0.07 µM). R222Q shifts voltage dependence of activation and inactivation in a negative direction but we observed positive shifts with E171Q. E171Q iPSC-CMs demonstrated abnormal spontaneous activity and prolonged action potentials. Molecular dynamics simulations revealed that both R222Q and E171Q proteins generate a water-filled permeation pathway that underlies generation of the gating pore current. Conclusion Previously identified MEPPC-associated variants that create gating pore currents are located in positively-charged residues in the S4 voltage sensor and generate negative shifts in the voltage dependence of activation and inactivation. We demonstrate that neutralizing a negatively charged S2 helix residue in the Gating Charge Transfer Center generates positive shifts but also create a gating pore pathway. These findings implicate the gating pore pathway as the primary functional and structural determinant of MEPPC and widen the spectrum of variants that are associated with gating pore-related disease in voltage-gated ion channels.
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Affiliation(s)
| | - Tao Yang
- Vanderbilt University Medical Center, Nashville, TN, USA
| | - Bian Li
- Vanderbilt University Medical Center, Nashville, TN, USA
- Current address: Regeneron Pharmaceuticals Inc., Tarrytown NY, USA. Bian Li contributed to this article as an employee of Vanderbilt University Medical Center and the views expressed do not necessarily represent the views of Regeneron Pharmaceuticals Inc
| | - Dana Page
- Simon Fraser University, Burnaby, BC, Canada
| | | | - Yuko Wada
- Vanderbilt University Medical Center, Nashville, TN, USA
| | | | | | | | - Xiaozhi Gao
- Mayo Clinic College of Medicine and Science, Mayo Foundation, Rochester, MN, USA
| | - Michael J. Ackerman
- Mayo Clinic College of Medicine and Science, Mayo Foundation, Rochester, MN, USA
| | | | | | - Dan M. Roden
- Vanderbilt University Medical Center, Nashville, TN, USA
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Arcos-Hernández C, Nishigaki T. Ion currents through the voltage sensor domain of distinct families of proteins. J Biol Phys 2023; 49:393-413. [PMID: 37851173 PMCID: PMC10651576 DOI: 10.1007/s10867-023-09645-z] [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: 04/28/2023] [Accepted: 09/11/2023] [Indexed: 10/19/2023] Open
Abstract
The membrane potential of a cell (Vm) regulates several physiological processes. The voltage sensor domain (VSD) is a region that confers voltage sensitivity to different types of transmembrane proteins such as the following: voltage-gated ion channels, the voltage-sensing phosphatase (Ci-VSP), and the sperm-specific Na+/H+ exchanger (sNHE). VSDs contain four transmembrane segments (S1-S4) and several positively charged amino acids in S4, which are essential for the voltage sensitivity of the protein. Generally, in response to changes of the Vm, the positive residues of S4 displace along the plasma membrane without generating ionic currents through this domain. However, some native (e.g., Hv1 channel) and mutants of VSDs produce ionic currents. These gating pore currents are usually observed in VSDs that lack one or more of the conserved positively charged amino acids in S4. The gating pore currents can also be induced by the isolation of a VSD from the rest of the protein domains. In this review, we summarize gating pore currents from all families of proteins with VSDs with classification into three cases: (1) pathological, (2) physiological, and (3) artificial currents. We reinforce the model in which the position of S4 that lacks the positively charged amino acid determines the voltage dependency of the gating pore current of all VSDs independent of protein families.
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Affiliation(s)
- César Arcos-Hernández
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico.
| | - Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
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Catacuzzeno L, Conti F, Franciolini F. Fifty years of gating currents and channel gating. J Gen Physiol 2023; 155:e202313380. [PMID: 37410612 PMCID: PMC10324510 DOI: 10.1085/jgp.202313380] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/12/2023] [Accepted: 06/02/2023] [Indexed: 07/08/2023] Open
Abstract
We celebrate this year the 50th anniversary of the first electrophysiological recordings of the gating currents from voltage-dependent ion channels done in 1973. This retrospective tries to illustrate the context knowledge on channel gating and the impact gating-current recording had then, and how it continued to clarify concepts, elaborate new ideas, and steer the scientific debate in these 50 years. The notion of gating particles and gating currents was first put forward by Hodgkin and Huxley in 1952 as a necessary assumption for interpreting the voltage dependence of the Na and K conductances of the action potential. 20 years later, gating currents were actually recorded, and over the following decades have represented the most direct means of tracing the movement of the gating charges and gaining insights into the mechanisms of channel gating. Most work in the early years was focused on the gating currents from the Na and K channels as found in the squid giant axon. With channel cloning and expression on heterologous systems, other channels as well as voltage-dependent enzymes were investigated. Other approaches were also introduced (cysteine mutagenesis and labeling, site-directed fluorometry, cryo-EM crystallography, and molecular dynamics [MD] modeling) to provide an integrated and coherent view of voltage-dependent gating in biological macromolecules. The layout of this retrospective reflects the past 50 years of investigations on gating currents, first addressing studies done on Na and K channels and then on other voltage-gated channels and non-channel structures. The review closes with a brief overview of how the gating-charge/voltage-sensor movements are translated into pore opening and the pathologies associated with mutations targeting the structures involved with the gating currents.
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Affiliation(s)
- Luigi Catacuzzeno
- Department of Chemistry Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Franco Conti
- Department of Physics, University of Genova, Genova, Italy
| | - Fabio Franciolini
- Department of Chemistry Biology and Biotechnology, University of Perugia, Perugia, Italy
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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.
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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
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8
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Remme CA. SCN5A channelopathy: arrhythmia, cardiomyopathy, epilepsy and beyond. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220164. [PMID: 37122208 PMCID: PMC10150216 DOI: 10.1098/rstb.2022.0164] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 12/31/2022] [Indexed: 05/02/2023] Open
Abstract
Influx of sodium ions through voltage-gated sodium channels in cardiomyocytes is essential for proper electrical conduction within the heart. Both acquired conditions associated with sodium channel dysfunction (myocardial ischaemia, heart failure) as well as inherited disorders secondary to mutations in the gene SCN5A encoding for the cardiac sodium channel Nav1.5 are associated with life-threatening arrhythmias. Research in the last decade has uncovered the complex nature of Nav1.5 distribution, function, in particular within distinct subcellular subdomains of cardiomyocytes. Nav1.5-based channels furthermore display previously unrecognized non-electrogenic actions and may impact on cardiac structural integrity, leading to cardiomyopathy. Moreover, SCN5A and Nav1.5 are expressed in cell types other than cardiomyocytes as well as various extracardiac tissues, where their functional role in, e.g. epilepsy, gastrointestinal motility, cancer and the innate immune response is increasingly investigated and recognized. This review provides an overview of these novel insights and how they deepen our mechanistic knowledge on SCN5A channelopathies and Nav1.5 (dys)function. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Affiliation(s)
- Carol Ann Remme
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam UMC location AMC, University of Amsterdam, Amsterdam, The Netherlands
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Hu X, Kong J, Niu T, Chen L, Yang J. Single coronary artery presenting dilated cardiomyopathy and hyperlipidemia with the SCN5A and APOA5 gene mutation: A case report and review of the literature. Front Cardiovasc Med 2023; 10:1113886. [PMID: 37288251 PMCID: PMC10242075 DOI: 10.3389/fcvm.2023.1113886] [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: 12/01/2022] [Accepted: 03/23/2023] [Indexed: 06/09/2023] Open
Abstract
We present a 55-year-old man with chest tightness and dyspnoea after activity lasting for 2 months who was diagnosed with single coronary artery (SCA) and presented with dilated cardiomyopathy (DCM) with the c.1858C > T mutation in the SCN5A gene. The computed tomography coronary angiogram (CTCA) showed congenital absence of the right coronary artery (RCA), and the right heart was nourished by the left coronary artery branch with no apparent stenosis. Transthoracic echocardiography (TTE) revealed enlargement of the left heart and cardiomyopathy. Cardiac magnetic resonance imaging (CMR) revealed DCM. Genetic testing showed that the c.1858C > T variant of the SCN5A gene could lead to Brugada syndrome and DCM. SCA is a rare congenital anomaly of the coronary anatomy, and this case reported as SCA accompanied by DCM is even rarer. We present a rare case of a 55-year-old man with DCM with the c.1858C > T (p. Arg620Cys)/c.1008G > A (p.(Pro336=) variant of the SCN5A gene, congenital absence of RCA, and c.990_993delAACA (p. Asp332Valfs*5) variant of the APOA5 gene. To our knowledge, this is the first report of DCM combined with the SCN5A gene mutation in SCA after searching the PubMed, CNKI and Wanfang databases.
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Affiliation(s)
- Xiaoxia Hu
- Department of Cardiology, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Jing Kong
- Department of Cardiology, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Tingting Niu
- Department of Medical Technology, Jinan Vocational College of Nursing, Jinan, Shandong, China
| | - Liang Chen
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Jingjing Yang
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
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Hu J, Yang K, Zhao Y, Wei Z, Yang L, Gao R, Wu Y, Xu L, Xu S, Hu K, Sun A, Ge J. Association between SCN5A R225Q variant and dilated cardiomyopathy: potential role of intracellular pH and WNT/β-catenin pathway. J Med Genet 2022; 59:1139-1149. [PMID: 35701104 DOI: 10.1136/jmedgenet-2021-108396] [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: 12/21/2021] [Accepted: 05/24/2022] [Indexed: 01/12/2023]
Abstract
BACKGROUND The SCN5A variant is a common cause of familial dilated cardiomyopathy (DCM). We previously reported a SCN5A variant (c.674G>A), located in the high-risk S4 segment of domain I (DI-S4) region in patients with idiopathic DCM and R225Q knockin (p.R225Q) mice carrying the c.674G>A variant exhibited prolonged baseline PR intervals without DCM phenotypes. In this study, we explored the association and mechanism between R225Q variant and DCM phenotype. METHODS Prevalence of DI-S4 variant was compared between patients with idiopathic DCM and the control participants. R225Q knockin and wild-type (WT) mice were subjected to doxorubicin (DOX), D-galactose (D-gal) or D-gal combined with DOX. RESULTS Clinical data suggested that the prevalence of DI-S4 variant was higher in DCM group than in the control group (4/90 (4.4%) vs 3/1339 (0.2%), p<0.001). Cardiomyocytes from R225Q knockin mice treated with D-gal and DOX exhibited more significant hypertrophic phenotype and weaker contraction/dilation function and an increased level of apoptosis as compared with WT mice. Mechanistically, we found that R225Q variant could increase intracellular pH and further induce the activation of the WNT/β-catenin pathway as well as the overexpression of pro-hypertrophic and pro-apoptotic targets. WNT-C59 inhibitor improved cardiac function in the R225Q knockin mice treated with D-gal and DOX. CONCLUSION Our results suggest that R225Q variant is associated with increased susceptibility to DCM. Ageing could enhance this process via activating WNT/β-catenin signaling in response to increased intracellular pH. Antagonising the WNT/β-catenin pathway might be a potential therapeutic strategy for mitigating R225Q variant-related DCM pathogenesis.
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Affiliation(s)
- Jingjing Hu
- Cardiology Department, Zhong Shan Hospital, Shanghai, China.,Cardiology Department, The First Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, Zhejiang Province, China, China
| | - Kun Yang
- Cardiology Department, Zhong Shan Hospital, Shanghai, China
| | - Yongchao Zhao
- Cardiology Department, Zhong Shan Hospital, Shanghai, China
| | - Zilun Wei
- Cardiology Department, Zhong Shan Hospital, Shanghai, China
| | - Lebing Yang
- Wen Zhou Yi Ke Da Xue, Wenzhou, Zhejiang, China
| | - Rifeng Gao
- Cardiology Department, Zhong Shan Hospital, Shanghai, China
| | - Yonghui Wu
- Wen Zhou Yi Ke Da Xue, Wenzhou, Zhejiang, China
| | - Lei Xu
- Cardiology Department, Zhong Shan Hospital, Shanghai, China
| | - Sujuan Xu
- Cardiology Department, Zhong Shan Hospital, Shanghai, China
| | - Kai Hu
- Cardiology Department, Zhong Shan Hospital, Shanghai, China
| | - Aijun Sun
- Cardiology Department, Zhong Shan Hospital, Shanghai, China
| | - Junbo Ge
- Cardiology Department, Zhong Shan Hospital, Shanghai, China
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11
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Gualdani R, Gailly P, Yuan JH, Yerna X, Di Stefano G, Truini A, Cruccu G, Dib-Hajj SD, Waxman SG. A TRPM7 mutation linked to familial trigeminal neuralgia: Omega current and hyperexcitability of trigeminal ganglion neurons. Proc Natl Acad Sci U S A 2022; 119:e2119630119. [PMID: 36095216 PMCID: PMC9499596 DOI: 10.1073/pnas.2119630119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Trigeminal neuralgia (TN) is a unique pain disorder characterized by intense paroxysmal facial pain within areas innervated by the trigeminal nerve. Although most cases of TN are sporadic, familial clusters of TN suggest that genetic factors may contribute to this disorder. Whole-exome sequencing in patients with TN reporting positive family history demonstrated a spectrum of variants of ion channels including TRP channels. Here, we used patch-clamp analysis and Ca2+ and Na+ imaging to assess a rare variant in the TRPM7 channel, p.Ala931Thr, within transmembrane domain 3, identified in a man suffering from unilateral TN. We showed that A931T produced an abnormal inward current carried by Na+ and insensitive to the pore blocker Gd3+. Hypothesizing that replacement of the hydrophobic alanine at position 931 with the more polar threonine destabilizes a hydrophobic ring, near the voltage sensor domain, we performed alanine substitutions of F971 and W972 and obtained results suggesting a role of A931-W972 hydrophobic interaction in S3-S4 hydrophobic cleft stability. Finally, we transfected trigeminal ganglion neurons with A931T channels and observed that expression of this TRPM7 variant lowers current threshold and resting membrane potential, and increases evoked firing activity in TG neurons. Our results support the notion that the TRPM7-A931T mutation located in the S3 segment at the interface with the transmembrane region S4, generates an omega current that carries Na+ influx in physiological conditions. A931T produces hyperexcitability and a sustained Na+ influx in trigeminal ganglion neurons that may underlie pain in this kindred with trigeminal neuralgia.
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Affiliation(s)
- Roberta Gualdani
- aInstitute of Neuroscience, Université catholique de Louvain, B-1200 Brussels, Belgium
| | - Philippe Gailly
- aInstitute of Neuroscience, Université catholique de Louvain, B-1200 Brussels, Belgium
| | - Jun-Hui Yuan
- bDepartment of Neurology, Yale School of Medicine, New Haven, CT 06520
- cCenter for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT 06515
| | - Xavier Yerna
- aInstitute of Neuroscience, Université catholique de Louvain, B-1200 Brussels, Belgium
| | - Giulia Di Stefano
- dDepartment of Human Neuroscience, Sapienza University, 00185 Rome, Italy
| | - Andrea Truini
- dDepartment of Human Neuroscience, Sapienza University, 00185 Rome, Italy
| | - Giorgio Cruccu
- dDepartment of Human Neuroscience, Sapienza University, 00185 Rome, Italy
| | - Sulayman D. Dib-Hajj
- bDepartment of Neurology, Yale School of Medicine, New Haven, CT 06520
- cCenter for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT 06515
| | - Stephen G. Waxman
- bDepartment of Neurology, Yale School of Medicine, New Haven, CT 06520
- cCenter for Neuroscience and Regeneration Research, Veterans Affairs Connecticut Healthcare, West Haven, CT 06515
- 2To whom correspondence may be addressed.
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12
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Lukas Laws J, Lancaster MC, Ben Shoemaker M, Stevenson WG, Hung RR, Wells Q, Marshall Brinkley D, Hughes S, Anderson K, Roden D, Stevenson LW. Arrhythmias as Presentation of Genetic Cardiomyopathy. Circ Res 2022; 130:1698-1722. [PMID: 35617362 PMCID: PMC9205615 DOI: 10.1161/circresaha.122.319835] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
There is increasing evidence regarding the prevalence of genetic cardiomyopathies, for which arrhythmias may be the first presentation. Ventricular and atrial arrhythmias presenting in the absence of known myocardial disease are often labelled as idiopathic, or lone. While ventricular arrhythmias are well-recognized as presentation for arrhythmogenic cardiomyopathy in the right ventricle, the scope of arrhythmogenic cardiomyopathy has broadened to include those with dominant left ventricular involvement, usually with a phenotype of dilated cardiomyopathy. In addition, careful evaluation for genetic cardiomyopathy is also warranted for patients presenting with frequent premature ventricular contractions, conduction system disease, and early onset atrial fibrillation, in which most detected genes are in the cardiomyopathy panels. Sudden death can occur early in the course of these genetic cardiomyopathies, for which risk is not adequately tracked by left ventricular ejection fraction. Only a few of the cardiomyopathy genotypes implicated in early sudden death are recognized in current indications for implantable cardioverter defibrillators which otherwise rely upon a left ventricular ejection fraction ≤0.35 in dilated cardiomyopathy. The genetic diagnoses impact other aspects of clinical management such as exercise prescription and pharmacological therapy of arrhythmias, and new therapies are coming into clinical investigation for specific genetic cardiomyopathies. The expansion of available genetic information and implications raises new challenges for genetic counseling, particularly with the family member who has no evidence of a cardiomyopathy phenotype and may face a potentially negative impact of a genetic diagnosis. Discussions of risk for both probands and relatives need to be tailored to their numeric literacy during shared decision-making. For patients presenting with arrhythmias or cardiomyopathy, extension of genetic testing and its implications will enable cascade screening, intervention to change the trajectory for specific genotype-phenotype profiles, and enable further development and evaluation of emerging targeted therapies.
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Affiliation(s)
- J Lukas Laws
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Megan C Lancaster
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
| | - M Ben Shoemaker
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
| | - William G Stevenson
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Rebecca R Hung
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Quinn Wells
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
| | - D Marshall Brinkley
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Sean Hughes
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Katherine Anderson
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Dan Roden
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
| | - Lynne W Stevenson
- Division of Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, TN
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13
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Ferreira AC, Dias‐Filho CAA, Jesus Silva Soares Junior N, Dias CJ, Monteiro SCM, Andrade RM, Mostarda CT. Phenotypes of mutations related to voltage‐dependent sodium channels on children and adolescents. J Biochem Mol Toxicol 2022; 36:e22993. [DOI: 10.1002/jbt.22993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 11/30/2021] [Accepted: 01/04/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Andressa Coelho Ferreira
- Laboratory of Cardiovascular Adaptations to Exercise—LACORE, Physical Education Department University Federal of Maranhão São Luís Brazil
| | - Carlos Alberto Alves Dias‐Filho
- Laboratory of Cardiovascular Adaptations to Exercise—LACORE, Physical Education Department University Federal of Maranhão São Luís Brazil
| | - Nivaldo Jesus Silva Soares Junior
- Laboratory of Cardiovascular Adaptations to Exercise—LACORE, Physical Education Department University Federal of Maranhão São Luís Brazil
| | - Carlos José Dias
- Laboratory of Cardiovascular Adaptations to Exercise—LACORE, Physical Education Department University Federal of Maranhão São Luís Brazil
- Physical Education Department UFMA Sao Luis Brazil
| | - Sally Cristina Moutinho Monteiro
- Laboratory of Cardiovascular Adaptations to Exercise—LACORE, Physical Education Department University Federal of Maranhão São Luís Brazil
- Pharmacy Department UFMA Sao Luis Brazil
| | - Rafael Martins Andrade
- Laboratory of Cardiovascular Adaptations to Exercise—LACORE, Physical Education Department University Federal of Maranhão São Luís Brazil
| | - Cristiano Teixeira Mostarda
- Laboratory of Cardiovascular Adaptations to Exercise—LACORE, Physical Education Department University Federal of Maranhão São Luís Brazil
- Pharmacy Department UFMA Sao Luis Brazil
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14
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Peters S, Thompson BA, Perrin M, James P, Zentner D, Kalman JM, Vandenberg JI, Fatkin D. Arrhythmic Phenotypes Are a Defining Feature of Dilated Cardiomyopathy-Associated SCN5A Variants: A Systematic Review. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2022; 15:e003432. [PMID: 34949099 DOI: 10.1161/circgen.121.003432] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Variants in the SCN5A gene, that encodes the cardiac sodium channel, Nav1.5, are associated with a highly arrhythmogenic form of dilated cardiomyopathy (DCM). Our aim was to review the phenotypes, natural history, functional effects, and treatment outcomes of DCM-associated rare SCN5A variants. METHODS A systematic review of reported DCM-associated rare SCN5A variants was undertaken using PubMed and Embase. RESULTS Eighteen SCN5A rare variants in 29 families with DCM (173 affected individuals) were identified. Eleven variants had undergone experimental evaluation, with 7 of these resulting in increased sustained current flow during the action potential (eg, increased window current) and at resting membrane potentials (eg, creation of a new gating pore current). These variants were located in transmembrane voltage-sensing domains and had a consistent phenotype characterized by frequent multifocal narrow and broad complex ventricular premature beats (VPB; 72% of affected relatives), ventricular arrhythmias (33%), atrial arrhythmias (32%), sudden cardiac death (13%), and DCM (56%). This VPB-predominant phenotype was not seen with 1 variant that increased late sodium current, or with variants that reduced peak current density or had mixed effects. In the latter groups, affected individuals mainly showed sinus node dysfunction, conduction defects, and atrial arrhythmias, with infrequent VPB and ventricular arrhythmias. DCM did not occur in the absence of arrhythmias for any variant. Twelve studies (23 total patients) reported treatment success in the VPB-predominant cardiomyopathy using sodium channel-blocking drug therapy. CONCLUSIONS SCN5A variants can present with a diverse spectrum of primary arrhythmic features. A majority of DCM-associated variants cause a multifocal VPB-predominant cardiomyopathy that is reversible with sodium channel blocking drug therapy. Early recognition of the distinctive phenotype and prompt genetic testing to identify variant carriers are needed. Our findings have implications for interpretation and management of SCN5A variants found in DCM patients with and without arrhythmias.
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Affiliation(s)
- Stacey Peters
- Department of Cardiology (S.P., M.P., D.Z., J.M.K.), Royal Melbourne Hospital
- Department of Genomic Medicine (S.P., B.A.T., M.P., P.J., D.Z.), Royal Melbourne Hospital
- Department of Medicine, University of Melbourne (S.P., P.J., D.Z., J.M.K.)
| | - Bryony A Thompson
- Department of Genomic Medicine (S.P., B.A.T., M.P., P.J., D.Z.), Royal Melbourne Hospital
- Department of Pathology (B.A.T.), Royal Melbourne Hospital
| | - Mark Perrin
- Department of Genomic Medicine (S.P., B.A.T., M.P., P.J., D.Z.), Royal Melbourne Hospital
| | - Paul James
- Department of Genomic Medicine (S.P., B.A.T., M.P., P.J., D.Z.), Royal Melbourne Hospital
- Department of Medicine, University of Melbourne (S.P., P.J., D.Z., J.M.K.)
- Familial Cancer Centre, Peter MacCallum Centre, Melbourne, Victoria (P.J.)
| | - Dominica Zentner
- Department of Genomic Medicine (S.P., B.A.T., M.P., P.J., D.Z.), Royal Melbourne Hospital
- Department of Medicine, University of Melbourne (S.P., P.J., D.Z., J.M.K.)
| | - Jonathan M Kalman
- Department of Medicine, University of Melbourne (S.P., P.J., D.Z., J.M.K.)
| | - Jamie I Vandenberg
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute (J.I.V., D.F.)
- St. Vincent's Clinical School, Faculty of Medicine, UNSW Sydney (J.I.V., D.F.)
| | - Diane Fatkin
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute (J.I.V., D.F.)
- St. Vincent's Clinical School, Faculty of Medicine, UNSW Sydney (J.I.V., D.F.)
- Cardiology Department, St. Vincent's Hospital, Sydney, New South Wales, Australia (D.F.)
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15
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Camman M, Joanne P, Agbulut O, Hélary C. 3D models of dilated cardiomyopathy: Shaping the chemical, physical and topographical properties of biomaterials to mimic the cardiac extracellular matrix. Bioact Mater 2022; 7:275-291. [PMID: 34466733 PMCID: PMC8379361 DOI: 10.1016/j.bioactmat.2021.05.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/21/2021] [Accepted: 05/21/2021] [Indexed: 12/12/2022] Open
Abstract
The pathophysiology of dilated cardiomyopathy (DCM), one major cause of heart failure, is characterized by the dilation of the heart but remains poorly understood because of the lack of adequate in vitro models. Current 2D models do not allow for the 3D organotypic organization of cardiomyocytes and do not reproduce the ECM perturbations. In this review, the different strategies to mimic the chemical, physical and topographical properties of the cardiac tissue affected by DCM are presented. The advantages and drawbacks of techniques generating anisotropy required for the cardiomyocytes alignment are discussed. In addition, the different methods creating macroporosity and favoring organotypic organization are compared. Besides, the advances in the induced pluripotent stem cells technology to generate cardiac cells from healthy or DCM patients will be described. Thanks to the biomaterial design, some features of the DCM extracellular matrix such as stiffness, porosity, topography or chemical changes can impact the cardiomyocytes function in vitro and increase their maturation. By mimicking the affected heart, both at the cellular and at the tissue level, 3D models will enable a better understanding of the pathology and favor the discovery of novel therapies.
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Affiliation(s)
- Marie Camman
- Sorbonne Université, CNRS, UMR 7574, Laboratoire de Chimie de la Matière Condensée de Paris, 4 place Jussieu (case 174), F-75005, Paris, France
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, 7 quai St-Bernard (case 256), F-75005, Paris, France
| | - Pierre Joanne
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, 7 quai St-Bernard (case 256), F-75005, Paris, France
| | - Onnik Agbulut
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, 7 quai St-Bernard (case 256), F-75005, Paris, France
| | - Christophe Hélary
- Sorbonne Université, CNRS, UMR 7574, Laboratoire de Chimie de la Matière Condensée de Paris, 4 place Jussieu (case 174), F-75005, Paris, France
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16
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Sedaghat-Hamedani F, Rebs S, El-Battrawy I, Chasan S, Krause T, Haas J, Zhong R, Liao Z, Xu Q, Zhou X, Akin I, Zitron E, Frey N, Streckfuss-Bömeke K, Kayvanpour E. Identification of SCN5a p.C335R Variant in a Large Family with Dilated Cardiomyopathy and Conduction Disease. Int J Mol Sci 2021; 22:ijms222312990. [PMID: 34884792 PMCID: PMC8657717 DOI: 10.3390/ijms222312990] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/08/2021] [Accepted: 11/26/2021] [Indexed: 12/30/2022] Open
Abstract
Introduction: Familial dilated cardiomyopathy (DCM) is clinically variable and has been associated with mutations in more than 50 genes. Rapid improvements in DNA sequencing have led to the identification of diverse rare variants with unknown significance (VUS), which underlines the importance of functional analyses. In this study, by investigating human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), we evaluated the pathogenicity of the p.C335R sodium voltage-gated channel alpha subunit 5 (SCN5a) variant in a large family with familial DCM and conduction disease. Methods: A four-generation family with autosomal dominant familial DCM was investigated. Next-generation sequencing (NGS) was performed in all 16 family members. Clinical deep phenotyping, including endomyocardial biopsy, was performed. Skin biopsies from two patients and one healthy family member were used to generate human-induced pluripotent stem cells (iPSCs), which were then differentiated into cardiomyocytes. Patch-clamp analysis with Xenopus oocytes and iPSC-CMs were performed. Results: A SCN5a variant (c.1003T>C; p.C335R) could be detected in all family members with DCM or conduction disease. A novel truncating TTN variant (p.Ser24998LysfsTer28) could also be identified in two family members with DCM. Family members with the SCN5a variant (p.C335R) showed significantly longer PQ and QRS intervals and lower left ventricular ejection fractions (LV-EF). All four patients who received CRT-D were non-responders. Electrophysiological analysis with Xenopus oocytes showed a loss of function in SCN5a p.C335R. Na+ channel currents were also reduced in iPSC-CMs from DCM patients. Furthermore, iPSC-CM with compound heterozygosity (SCN5a p.C335R and TTNtv) showed significant dysregulation of sarcomere structures, which may be contributed to the severity of the disease and earlier onset of DCM. Conclusion: The SCN5a p.C335R variant is causing a loss of function of peak INa in patients with DCM and cardiac conduction disease. The co-existence of genetic variants in channels and structural genes (e.g., SCN5a p.C335R and TTNtv) increases the severity of the DCM phenotype.
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Affiliation(s)
- Farbod Sedaghat-Hamedani
- Department of Medicine III, Institute for Cardiomyopathies Heidelberg (ICH), University of Heidelberg, 69120 Heidelberg, Germany; (F.S.-H.); (S.C.); (T.K.); (J.H.); (E.Z.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Heidelberg-Mannheim, 17475 Greifswald, Germany; (I.E.-B.); (X.Z.); (I.A.)
| | - Sabine Rebs
- Clinic for Cardiology and Pneumology, Georg-August-University Göttingen, 37073 Göttingen, Germany; (S.R.); (K.S.-B.)
- DZHK (German Centre for Cardiovascular Research), 37073 Göttingen, Germany
- Institute of Pharmacology and Toxicology, University of Würzburg, 97070 Würzburg, Germany
| | - Ibrahim El-Battrawy
- DZHK (German Centre for Cardiovascular Research), Heidelberg-Mannheim, 17475 Greifswald, Germany; (I.E.-B.); (X.Z.); (I.A.)
- Department of Medicine, University Medical Centre Mannheim (UMM), 68159 Mannheim, Germany; (R.Z.); (Z.L.); (Q.X.)
| | - Safak Chasan
- Department of Medicine III, Institute for Cardiomyopathies Heidelberg (ICH), University of Heidelberg, 69120 Heidelberg, Germany; (F.S.-H.); (S.C.); (T.K.); (J.H.); (E.Z.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Heidelberg-Mannheim, 17475 Greifswald, Germany; (I.E.-B.); (X.Z.); (I.A.)
| | - Tobias Krause
- Department of Medicine III, Institute for Cardiomyopathies Heidelberg (ICH), University of Heidelberg, 69120 Heidelberg, Germany; (F.S.-H.); (S.C.); (T.K.); (J.H.); (E.Z.); (N.F.)
| | - Jan Haas
- Department of Medicine III, Institute for Cardiomyopathies Heidelberg (ICH), University of Heidelberg, 69120 Heidelberg, Germany; (F.S.-H.); (S.C.); (T.K.); (J.H.); (E.Z.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Heidelberg-Mannheim, 17475 Greifswald, Germany; (I.E.-B.); (X.Z.); (I.A.)
| | - Rujia Zhong
- Department of Medicine, University Medical Centre Mannheim (UMM), 68159 Mannheim, Germany; (R.Z.); (Z.L.); (Q.X.)
| | - Zhenxing Liao
- Department of Medicine, University Medical Centre Mannheim (UMM), 68159 Mannheim, Germany; (R.Z.); (Z.L.); (Q.X.)
| | - Qiang Xu
- Department of Medicine, University Medical Centre Mannheim (UMM), 68159 Mannheim, Germany; (R.Z.); (Z.L.); (Q.X.)
| | - Xiaobo Zhou
- DZHK (German Centre for Cardiovascular Research), Heidelberg-Mannheim, 17475 Greifswald, Germany; (I.E.-B.); (X.Z.); (I.A.)
- Department of Medicine, University Medical Centre Mannheim (UMM), 68159 Mannheim, Germany; (R.Z.); (Z.L.); (Q.X.)
| | - Ibrahim Akin
- DZHK (German Centre for Cardiovascular Research), Heidelberg-Mannheim, 17475 Greifswald, Germany; (I.E.-B.); (X.Z.); (I.A.)
- Department of Medicine, University Medical Centre Mannheim (UMM), 68159 Mannheim, Germany; (R.Z.); (Z.L.); (Q.X.)
| | - Edgar Zitron
- Department of Medicine III, Institute for Cardiomyopathies Heidelberg (ICH), University of Heidelberg, 69120 Heidelberg, Germany; (F.S.-H.); (S.C.); (T.K.); (J.H.); (E.Z.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Heidelberg-Mannheim, 17475 Greifswald, Germany; (I.E.-B.); (X.Z.); (I.A.)
| | - Norbert Frey
- Department of Medicine III, Institute for Cardiomyopathies Heidelberg (ICH), University of Heidelberg, 69120 Heidelberg, Germany; (F.S.-H.); (S.C.); (T.K.); (J.H.); (E.Z.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Heidelberg-Mannheim, 17475 Greifswald, Germany; (I.E.-B.); (X.Z.); (I.A.)
| | - Katrin Streckfuss-Bömeke
- Clinic for Cardiology and Pneumology, Georg-August-University Göttingen, 37073 Göttingen, Germany; (S.R.); (K.S.-B.)
- DZHK (German Centre for Cardiovascular Research), 37073 Göttingen, Germany
- Institute of Pharmacology and Toxicology, University of Würzburg, 97070 Würzburg, Germany
| | - Elham Kayvanpour
- Department of Medicine III, Institute for Cardiomyopathies Heidelberg (ICH), University of Heidelberg, 69120 Heidelberg, Germany; (F.S.-H.); (S.C.); (T.K.); (J.H.); (E.Z.); (N.F.)
- DZHK (German Centre for Cardiovascular Research), Heidelberg-Mannheim, 17475 Greifswald, Germany; (I.E.-B.); (X.Z.); (I.A.)
- Correspondence:
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17
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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.
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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
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18
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Rivaud MR, Delmar M, Remme CA. Heritable arrhythmia syndromes associated with abnormal cardiac sodium channel function: ionic and non-ionic mechanisms. Cardiovasc Res 2021; 116:1557-1570. [PMID: 32251506 PMCID: PMC7341171 DOI: 10.1093/cvr/cvaa082] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/01/2020] [Accepted: 04/01/2020] [Indexed: 12/19/2022] Open
Abstract
The cardiac sodium channel NaV1.5, encoded by the SCN5A gene, is responsible for the fast upstroke of the action potential. Mutations in SCN5A may cause sodium channel dysfunction by decreasing peak sodium current, which slows conduction and facilitates reentry-based arrhythmias, and by enhancing late sodium current, which prolongs the action potential and sets the stage for early afterdepolarization and arrhythmias. Yet, some NaV1.5-related disorders, in particular structural abnormalities, cannot be directly or solely explained on the basis of defective NaV1.5 expression or biophysics. An emerging concept that may explain the large disease spectrum associated with SCN5A mutations centres around the multifunctionality of the NaV1.5 complex. In this alternative view, alterations in NaV1.5 affect processes that are independent of its canonical ion-conducting role. We here propose a novel classification of NaV1.5 (dys)function, categorized into (i) direct ionic effects of sodium influx through NaV1.5 on membrane potential and consequent action potential generation, (ii) indirect ionic effects of sodium influx on intracellular homeostasis and signalling, and (iii) non-ionic effects of NaV1.5, independent of sodium influx, through interactions with macromolecular complexes within the different microdomains of the cardiomyocyte. These indirect ionic and non-ionic processes may, acting alone or in concert, contribute significantly to arrhythmogenesis. Hence, further exploration of these multifunctional effects of NaV1.5 is essential for the development of novel preventive and therapeutic strategies.
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Affiliation(s)
- Mathilde R Rivaud
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam UMC (location AMC), University of Amsterdam, Amsterdam Cardiovascular Sciences, Meigberdreef 15, 1105AZ Amsterdam, The Netherlands
| | - Mario Delmar
- The Leon H. Charney Division of Cardiology, New York University School of Medicine, 435 E 30th St, NSB 707, New York, NY 10016, USA
| | - Carol Ann Remme
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam UMC (location AMC), University of Amsterdam, Amsterdam Cardiovascular Sciences, Meigberdreef 15, 1105AZ Amsterdam, The Netherlands
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19
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Marian AJ, Asatryan B, Wehrens XHT. Genetic basis and molecular biology of cardiac arrhythmias in cardiomyopathies. Cardiovasc Res 2021; 116:1600-1619. [PMID: 32348453 DOI: 10.1093/cvr/cvaa116] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/09/2020] [Accepted: 04/21/2020] [Indexed: 12/19/2022] Open
Abstract
Cardiac arrhythmias are common, often the first, and sometimes the life-threatening manifestations of hereditary cardiomyopathies. Pathogenic variants in several genes known to cause hereditary cardiac arrhythmias have also been identified in the sporadic cases and small families with cardiomyopathies. These findings suggest a shared genetic aetiology of a subset of hereditary cardiomyopathies and cardiac arrhythmias. The concept of a shared genetic aetiology is in accord with the complex and exquisite interplays that exist between the ion currents and cardiac mechanical function. However, neither the causal role of cardiac arrhythmias genes in cardiomyopathies is well established nor the causal role of cardiomyopathy genes in arrhythmias. On the contrary, secondary changes in ion currents, such as post-translational modifications, are common and contributors to the pathogenesis of arrhythmias in cardiomyopathies through altering biophysical and functional properties of the ion channels. Moreover, structural changes, such as cardiac hypertrophy, dilatation, and fibrosis provide a pro-arrhythmic substrate in hereditary cardiomyopathies. Genetic basis and molecular biology of cardiac arrhythmias in hereditary cardiomyopathies are discussed.
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Affiliation(s)
- Ali J Marian
- Department of Medicine, Center for Cardiovascular Genetics, Institute of Molecular Medicine, University of Texas Health Sciences Center at Houston, 6770 Bertner Street, Suite C900A, Houston, TX 77030, USA
| | - Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Xander H T Wehrens
- Department of Biophysics and Molecular Physiology, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
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20
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Plumereau Q, Theriault O, Pouliot V, Moreau A, Morel E, Fressart V, Denjoy I, Delinière A, Bessière F, Chevalier P, Gamal El-Din TM, Chahine M. Novel G1481V and Q1491H SCN5A Mutations Linked to Long QT Syndrome Destabilize the Nav1.5 Inactivation State. CJC Open 2021; 3:256-266. [PMID: 33778442 PMCID: PMC7984979 DOI: 10.1016/j.cjco.2020.09.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 09/27/2020] [Indexed: 12/02/2022] Open
Abstract
Background Nav1.5, which is encoded by the SCN5A gene, is the predominant voltage-gated Na+ channel in the heart. Several mutations of this gene have been identified and reported to be involved in several cardiac rhythm disorders, including type 3 long QT interval syndrome, that can cause sudden cardiac death. We analyzed the biophysical properties of 2 novel variants of the Nav1.5 channel (Q1491H and G1481V) detected in 5- and 12-week-old infants diagnosed with a prolonged QT interval. Methods The Nav1.5 wild-type and the Q1491H and G1481V mutant channels were reproduced in vitro. Wild-type or mutant channels were cotransfected in human embryonic kidney (HEK) 293 cells with the beta 1 regulatory subunit. Na+ currents were recorded using the whole-cell configuration of the patch-clamp technique. Results The Q1491H mutant channel exhibited a lower current density, a persistent Na+ current, an enhanced window current due to a +20-mV shift of steady-state inactivation, a +10-mV shift of steady-state activation, a faster onset of slow inactivation, and a recovery from fast inactivation with fast and slow time constants of recovery. The G1481V mutant channel exhibited an increase in current density and a +7-mV shift of steady-state inactivation. The observed defects are characteristic of gain-of-function mutations typical of type 3 long QT interval syndrome. Conclusions The 5- and 12-week-old infants displayed prolonged QT intervals. Our analyses of the Q1491H and G1481V mutations correlated with the clinical diagnosis. The observed biophysical dysfunctions associated with both mutations were most likely responsible for the sudden deaths of the 2 infants.
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Affiliation(s)
| | | | | | - Adrien Moreau
- Inserm U1046, CNRS UMR 9214, Université de Montpellier, Montpellier, France
| | - Elodie Morel
- Lyon Reference Center for Inherited Arrhythmias, Louis Pradel Cardiovascular Hospital, Bron, France
| | - Véronique Fressart
- Centre de Génétique Moléculaire et Chromosomique, Hôpital Pitié-Salpêtrière, Paris, France
| | | | - Antoine Delinière
- Lyon Reference Center for Inherited Arrhythmias, Louis Pradel Cardiovascular Hospital, Bron, France
| | - Francis Bessière
- Lyon Reference Center for Inherited Arrhythmias, Louis Pradel Cardiovascular Hospital, Bron, France
| | - Philippe Chevalier
- Lyon Reference Center for Inherited Arrhythmias, Louis Pradel Cardiovascular Hospital, Bron, France.,Department of Rhythmology, Louis Pradel Cardiovascular Hospital, Lyon, France.,Université de Lyon, Lyon, France
| | | | - Mohamed Chahine
- CERVO Brain Research Center, Quebec City, Quebec, Canada.,Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, Quebec, Canada
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21
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iPSC-derived cardiomyocytes from patients with myotonic dystrophy type 1 have abnormal ion channel functions and slower conduction velocities. Sci Rep 2021; 11:2500. [PMID: 33510259 PMCID: PMC7844414 DOI: 10.1038/s41598-021-82007-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 10/21/2020] [Indexed: 02/07/2023] Open
Abstract
Cardiac complications such as electrical abnormalities including conduction delays and arrhythmias are the main cause of death in individuals with Myotonic Dystrophy type 1 (DM1). We developed a disease model using iPSC-derived cardiomyocytes (iPSC-CMs) from a healthy individual and two DM1 patients with different CTG repeats lengths and clinical history (DM1-1300 and DM1-300). We confirmed the presence of toxic RNA foci and mis-spliced MBNL1/2 transcripts in DM1 iPSC-CMs. In DM1-1300, we identified a switch in the cardiac sodium channel SCN5A from the adult to the neonatal isoform. The down-regulation of adult SCN5A isoforms is consistent with a shift in the sodium current activation to depolarized potentials observed in DM1-1300. L-type calcium current density was higher in iPSC-CMs from DM1-1300, which is correlated with the overexpression of the CaV1.2 transcript and proteins. Importantly, INa and ICaL dysfunctions resulted in prolonged action potentials duration, slower velocities, and decreased overshoots. Optical mapping analysis revealed a slower conduction velocity in DM1-1300 iPSC-CM monolayers. In conclusion, our data revealed two distinct ions channels perturbations in DM1 iPSC-CM from the patient with cardiac dysfunction, one affecting Na+ channels and one affecting Ca2+ channels. Both have an impact on cardiac APs and ultimately on heart conduction.
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22
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Blasco RL, Strauss M, Velázquez López DA, Tabares S, Sembaj A, Rivarola HW, Paglini PA, Lo Presti MS. SCN5A gene variants as potential markers of the progression of chronic chagasic cardiac alterations. Parasitol Int 2020; 80:102213. [PMID: 33137501 DOI: 10.1016/j.parint.2020.102213] [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: 04/13/2020] [Revised: 08/03/2020] [Accepted: 08/10/2020] [Indexed: 11/19/2022]
Abstract
Host genetic factors have been proposed as determinants of the variable progression of Chagas disease (ChD). Two polymorphisms, H558R and A572D, of the voltage-gated sodium channel α-subunit SCN5A gene were studied in chagasic patients in order to determine their contribution to the susceptibility to the development and/or to the progression of the cardiovascular disease. A total of 104 patients were classified as seronegative or seropositive for Trypanosoma cruzi antibodies. Clinical evaluation, electrocardiograms (ECG) and echocardiograms (Echo) were performed to detect any conduction and/or structural alteration. Patients were classified into: G1: without ECG and/or Echo alterations, G2: with ECG alterations and G3: with ECG and Echo alterations. H558R and A572D polymorphisms were detected by PCR. Cardiac alterations were more frequent in G2 + G3 seropositive patients. For H558R polymorphism, the C allele was significantly increased in seropositive G2 + G3 patients (P = 0.049. OR = 2.08; 95% CI = 1.12-4.33). When comparing the disease cardiac progression (G2 vs G3), the genotypes from the H558R polymorphism were associated to more intense cardiac alterations (P = 0.018). For A572D polymorphism, no associations were found. The results suggest a possible involvement of SCN5A polymorphisms in the susceptibility to chronic ChD and the disease progression, contributing to the elucidation of the molecular mechanism underlying this complex myocardiopathy. In this regard, this is the first work that studies this gene in the context of chagasic cardiomyopathy.
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Affiliation(s)
- Romina Laura Blasco
- Instituto de Investigaciones en Ciencias de la Salud (INICSA) UNC - CONICET, Centro de Estudios e Investigación de la Enfermedad de Chagas y Leishmaniasis, Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Argentina
| | - Mariana Strauss
- Instituto de Investigaciones en Ciencias de la Salud (INICSA) UNC - CONICET, Centro de Estudios e Investigación de la Enfermedad de Chagas y Leishmaniasis, Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Argentina.
| | - Daniela Alejandra Velázquez López
- Instituto de Investigaciones en Ciencias de la Salud (INICSA) UNC - CONICET, Centro de Estudios e Investigación de la Enfermedad de Chagas y Leishmaniasis, Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Argentina
| | - Sandra Tabares
- Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Argentina
| | - Adela Sembaj
- Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Argentina
| | - Héctor Walter Rivarola
- Instituto de Investigaciones en Ciencias de la Salud (INICSA) UNC - CONICET, Centro de Estudios e Investigación de la Enfermedad de Chagas y Leishmaniasis, Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Argentina
| | - Patricia Adriana Paglini
- Instituto de Investigaciones en Ciencias de la Salud (INICSA) UNC - CONICET, Centro de Estudios e Investigación de la Enfermedad de Chagas y Leishmaniasis, Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Argentina
| | - María Silvina Lo Presti
- Instituto de Investigaciones en Ciencias de la Salud (INICSA) UNC - CONICET, Centro de Estudios e Investigación de la Enfermedad de Chagas y Leishmaniasis, Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Argentina.
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23
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Nakajima T, Kaneko Y, Dharmawan T, Kurabayashi M. Role of the voltage sensor module in Na v domain IV on fast inactivation in sodium channelopathies: The implication of closed-state inactivation. Channels (Austin) 2020; 13:331-343. [PMID: 31357904 PMCID: PMC6713248 DOI: 10.1080/19336950.2019.1649521] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The segment 4 (S4) voltage sensor in voltage-gated sodium channels (Navs) have domain-specific functions, and the S4 segment in domain DIV (DIVS4) plays a key role in the activation and fast inactivation processes through the coupling of arginine residues in DIVS4 with residues of putative gating charge transfer center (pGCTC) in DIVS1-3. In addition, the first four arginine residues (R1-R4) in Nav DIVS4 have position-specific functions in the fast inactivation process, and mutations in these residues are associated with diverse phenotypes of Nav-related diseases (sodium channelopathies). R1 and R2 mutations commonly display a delayed fast inactivation, causing a gain-of-function, whereas R3 and R4 mutations commonly display a delayed recovery from inactivation and profound use-dependent current attenuation, causing a severe loss-of-function. In contrast, mutations of residues of pGCTC in Nav DIVS1-3 can also alter fast inactivation. Such alterations in fast inactivation may be caused by disrupted interactions of DIVS4 with DIVS1-3. Despite fast inactivation of Navs occurs from both the open-state (open-state inactivation; OSI) and closed state (closed-state inactivation; CSI), changes in CSI have received considerably less attention than those in OSI in the pathophysiology of sodium channelopathies. CSI can be altered by mutations of arginine residues in DIVS4 and residues of pGCTC in Navs, and altered CSI can be an underlying primary biophysical defect of sodium channelopathies. Therefore, CSI should receive focus in order to clarify the pathophysiology of sodium channelopathies.
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Affiliation(s)
- Tadashi Nakajima
- a Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine , Maebashi , Gunma , Japan
| | - Yoshiaki Kaneko
- a Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine , Maebashi , Gunma , Japan
| | - Tommy Dharmawan
- a Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine , Maebashi , Gunma , Japan
| | - Masahiko Kurabayashi
- a Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine , Maebashi , Gunma , Japan
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24
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Morales A, Kinnamon DD, Jordan E, Platt J, Vatta M, Dorschner MO, Starkey CA, Mead JO, Ai T, Burke W, Gastier-Foster J, Jarvik GP, Rehm HL, Nickerson DA, Hershberger RE. Variant Interpretation for Dilated Cardiomyopathy: Refinement of the American College of Medical Genetics and Genomics/ClinGen Guidelines for the DCM Precision Medicine Study. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2020; 13:e002480. [PMID: 32160020 DOI: 10.1161/circgen.119.002480] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND The hypothesis of the Dilated Cardiomyopathy Precision Medicine Study is that most dilated cardiomyopathy has a genetic basis. The study returns results to probands and, when indicated, to relatives. While both the American College of Medical Genetics and Genomics/Association for Molecular Pathology and ClinGen's MYH7-cardiomyopathy specifications provide relevant guidance for variant interpretation, further gene- and disease-specific considerations were required for dilated cardiomyopathy. To this end, we tailored the ClinGen MYH7-cardiomyopathy variant interpretation framework; the specifications implemented for the study are presented here. METHODS Modifications were created and approved by an external Variant Adjudication Oversight Committee. After a pilot using 81 probands, further adjustments were made, resulting in 27 criteria (9 modifications of the ClinGen MYH7 framework and reintroduction of 2 American College of Medical Genetics and Genomics/Association of Molecular Pathology criteria that were deemed not applicable by the ClinGen MYH7 working group). RESULTS These criteria were applied to 2059 variants in a test set of 97 probands. Variants were classified as benign (n=1702), likely benign (n=33), uncertain significance (n=71), likely pathogenic (likely pathogenic; n=12), and pathogenic (P; n=3). Only 2/15 likely pathogenic/P variants were identified in Non-Hispanic African ancestry probands. CONCLUSIONS We tailored the ClinGen MYH7 criteria for our study. Our preliminary data show that 15/97 (15.5%) probands have likely pathogenic/P variants, most of which were identified in probands of Non-Hispanic European ancestry. We anticipate continued evolution of our approach, one that will be informed by new insights on variant interpretation and a greater understanding of the genetic architecture of dilated cardiomyopathy. CLINICAL TRIAL REGISTRATION URL: https://www.clinicaltrials.gov; Unique identifier: NCT03037632.
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Affiliation(s)
- Ana Morales
- Division of Human Genetics, Department of Internal Medicine (A.M., D.D.K., E.J., C.S., J.M., T.A., R.E.H.), The Ohio State University, Columbus
| | - Daniel D Kinnamon
- Division of Human Genetics, Department of Internal Medicine (A.M., D.D.K., E.J., C.S., J.M., T.A., R.E.H.), The Ohio State University, Columbus
| | - Elizabeth Jordan
- Division of Human Genetics, Department of Internal Medicine (A.M., D.D.K., E.J., C.S., J.M., T.A., R.E.H.), The Ohio State University, Columbus
| | - Julia Platt
- Stanford Center for Inherited Cardiovascular Disease, Stanford University, Palo Alto, CA (J.P.)
| | - Matteo Vatta
- Department of Medical and Molecular Genetics, Indiana University, Indianapolis (M.V.).,Invitae, San Francisco, CA (M.V.)
| | | | - Carl A Starkey
- Division of Human Genetics, Department of Internal Medicine (A.M., D.D.K., E.J., C.S., J.M., T.A., R.E.H.), The Ohio State University, Columbus
| | - Jonathan O Mead
- Division of Human Genetics, Department of Internal Medicine (A.M., D.D.K., E.J., C.S., J.M., T.A., R.E.H.), The Ohio State University, Columbus
| | - Tomohiko Ai
- Division of Human Genetics, Department of Internal Medicine (A.M., D.D.K., E.J., C.S., J.M., T.A., R.E.H.), The Ohio State University, Columbus
| | - Wylie Burke
- Department of Bioethics and Humanities (W.B.), University of Washington, SA
| | - Julie Gastier-Foster
- Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH (J.G.-F.)
| | - Gail P Jarvik
- Division of Medical Genetics, Department of Medicine (G.P.J.), University of Washington, SA.,Department of Genome Sciences (G.P.J.), University of Washington, SA
| | - Heidi L Rehm
- Center for Genomic Medicine, Massachusetts General Hospital, Boston (H.L.R.).,Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (H.L.R.)
| | | | - Ray E Hershberger
- Division of Human Genetics, Department of Internal Medicine (A.M., D.D.K., E.J., C.S., J.M., T.A., R.E.H.), The Ohio State University, Columbus.,Division of Cardiovascular Medicine, Department of Internal Medicine (R.E.H.), The Ohio State University, Columbus
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25
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Abstract
Dilated cardiomyopathy (DCM) represents one of the primary cardiomyopathies and may lead to heart failure and sudden death. Until recently, ventricular arrhythmias were considered to be a direct consequence of the systolic dysfunction of the left ventricle (LV) and guidelines for implantable cardioverter defibrillator implantation were established on this basis. However, the identification of heritable dilated cardiomyopathy phenotypes that presented with mildly impaired or moderate LV dysfunction, with or without chamber dilatation, and ventricular arrhythmias exceeding the degree of the underlying morphological abnormalities lead to the identification of the arrhythmogenic phenotypes and genotypes of DCM. This subset of DCM patients presents phenotypic and in many cases genotypic overlaps with left dominant arrhythmogenic cardiomyopathy (LDAC). LMNA, SCN5A, FLNC, TTN, and RBM20 are the main genes responsible for arrhythmogenic DCM. Moreover, desmosomal genes such as DSP and other non-desmosomal such as DES and PLN have been associated with both LDAC and arrhythmogenic DCM. The aim of this review is to highlight the importance of genetic profiling among DCM patients with disproportionate arrhythmic burden and the significance of the electrocardiogram, cardiac magnetic resonance, Holter monitoring, detailed family history, and other assays in order to identify red flags for arrhythmogenic DCM and proceed to an early preventive approach for sudden cardiac death. A special consideration was given to the phenotypic and genotypic overlap with LDAC. The role of myocarditis as a common disease expression of LDAC and arrhythmogenic DCM is also analyzed supporting the premise of their phenotypic overlap.
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Affiliation(s)
- Thomas Zegkos
- 1st Cardiology Department, AHEPA University Hospital, Thessaloniki, Greece.
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26
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Mason ER, Wu F, Patel RR, Xiao Y, Cannon SC, Cummins TR. Resurgent and Gating Pore Currents Induced by De Novo SCN2A Epilepsy Mutations. eNeuro 2019; 6:ENEURO.0141-19.2019. [PMID: 31558572 PMCID: PMC6795554 DOI: 10.1523/eneuro.0141-19.2019] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 09/12/2019] [Accepted: 09/16/2019] [Indexed: 12/31/2022] Open
Abstract
Over 150 mutations in the SCN2A gene, which encodes the neuronal Nav1.2 protein, have been implicated in human epilepsy cases. Of these, R1882Q and R853Q are two of the most commonly reported mutations. This study utilized voltage-clamp electrophysiology to characterize the biophysical effects of the R1882Q and R853Q mutations on the hNav1.2 channel, including their effects on resurgent current and gating pore current, which are not typically investigated in the study of Nav1.2 channel mutations. HEK cells transiently transfected with DNA encoding either wild-type (WT) or mutant hNav1.2 revealed that the R1882Q mutation induced a gain-of-function phenotype, including slowed fast inactivation, depolarization of the voltage dependence of inactivation, and increased persistent current. In this model system, the R853Q mutation primarily produced loss-of-function effects, including reduced transient current amplitude and density, hyperpolarization of the voltage dependence of inactivation, and decreased persistent current. The presence of a Navβ4 peptide (KKLITFILKKTREK-OH) in the pipette solution induced resurgent currents, which were increased by the R1882Q mutation and decreased by the R853Q mutation. Further study of the R853Q mutation in Xenopus oocytes indicated a reduced surface expression and revealed a robust gating pore current at negative membrane potentials, a function absent in the WT channel. This not only shows that different epileptogenic point mutations in hNav1.2 have distinct biophysical effects on the channel, but also illustrates that individual mutations can have complex consequences that are difficult to identify using conventional analyses. Distinct mutations may, therefore, require tailored pharmacotherapies in order to eliminate seizures.
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Affiliation(s)
- Emily R Mason
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Fenfen Wu
- Department of Physiology, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, CA 90095-1751
| | - Reesha R Patel
- Program in Medical Neuroscience, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Yucheng Xiao
- School of Science, Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202
| | - Stephen C Cannon
- Department of Physiology, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, CA 90095-1751
| | - Theodore R Cummins
- School of Science, Biology Department Chair, Indiana University-Purdue University of Indianapolis, Indianapolis, IN 46202
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27
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Asatryan B. Cardiac Sodium Channel Dysfunction and Dilated Cardiomyopathy: A Contemporary Reappraisal of Pathophysiological Concepts. J Clin Med 2019; 8:jcm8071029. [PMID: 31336969 PMCID: PMC6678327 DOI: 10.3390/jcm8071029] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/07/2019] [Accepted: 07/09/2019] [Indexed: 12/19/2022] Open
Abstract
A key emerging theme in translational cardiovascular medicine is the need to identify specific causes of arrhythmias and heart failure, defined by phenotype and/or genotype that will respond to a particular intervention. Unlike other genes implicated in hereditary arrhythmias and cardiomyopathies, pathogenic/likely pathogenic variants in the cardiac sodium channel alpha subunit gene (SCN5A) produce a remarkably diverse set of electrical and structural phenotypes, one of them being dilated cardiomyopathy. There has been debate about whether left ventricular remodeling is a bona fide phenotypic feature of cardiac sodium channel dysfunction, or a consequence of tachyarrhythmias or conduction disturbances. In light of recent findings, a critical digest of the available experimental and medical literature is necessary. This paper provides a critical appraisal of the evidence linking a dysfunctional cardiac sodium channel to ventricular dysfunction, and discusses the potential mechanisms involved in shaping this phenotype along with implications for precision therapy.
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Affiliation(s)
- Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, Freiburgstrasse 10, 3010 Bern, Switzerland.
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28
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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
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29
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Mazzaccara C, Limongelli G, Petretta M, Vastarella R, Pacileo G, Bonaduce D, Salvatore F, Frisso G. A common polymorphism in the SCN5A gene is associated with dilated cardiomyopathy. J Cardiovasc Med (Hagerstown) 2019; 19:344-350. [PMID: 29782370 PMCID: PMC6012048 DOI: 10.2459/jcm.0000000000000670] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Aims SCN5A is a disease-causing gene associated with familial dilated cardiomyopathy (FDC). We examined the possible association between a common polymorphism in the SCN5A gene (c.1673A>G-p.H558R; rs1805124) and the risk of dilated cardiomyopathy (DCM) occurrence. Methods We genotyped 185 DCM cases (familial DCM, idiopathic DCM and postischemic DCM) and 251 controls for the p.H558R polymorphism in the SCN5A gene, to test the association of the molecular epidemiology of the individuals with the presence/absence of various types of DCM. Results Our results showed that the rs1805124 polymorphism was significantly associated with DCM, and the association was more significant in patients with FDC; furthermore, in these individuals, the less frequent GG genotype was associated with a 7.39-fold increased risk of disease [95% confidence interval (95% CI) = 2.88–18.96; P < 0.0001] compared with the AA genotype. Moreover, logistic regression analysis showed that GG carriers had a higher risk of DCM than AA + AG carriers (odds ratio = 5.45, 95% CI = 2.23–13.35; P < 0.001). No association was observed between the rs1805124 and DCM risk in postischemic DCM patients. Conclusion Our study demonstrates an association between familial DCM and the rs1805124 polymorphism in the SCN5A gene, which may unravel additional genetic predisposition to the development of a multifactorial disease as DCM.
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Affiliation(s)
- Cristina Mazzaccara
- CEINGE-Biotecnologie Avanzate s.c.a r.l.,Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli 'Federico II'
| | - Giuseppe Limongelli
- Dipartimento di Scienze Cardiotoraciche e Respiratorie, Università degli Studi della Campania 'Luigi Vanvitelli', A.O. Monaldi, Azienda dei Colli
| | - Mario Petretta
- Dipartimento di Scienze Mediche Traslazionali, Università di Napoli 'Federico II'
| | - Rossella Vastarella
- Dipartimento di Scienze Cardiotoraciche e Respiratorie, Università degli Studi della Campania 'Luigi Vanvitelli', A.O. Monaldi, Azienda dei Colli
| | - Giuseppe Pacileo
- Dipartimento di Scienze Cardiotoraciche e Respiratorie, Università degli Studi della Campania 'Luigi Vanvitelli', A.O. Monaldi, Azienda dei Colli
| | - Domenico Bonaduce
- Dipartimento di Scienze Mediche Traslazionali, Università di Napoli 'Federico II'
| | - Francesco Salvatore
- CEINGE-Biotecnologie Avanzate s.c.a r.l.,IRCCS-Fondazione SDN, Napoli, Italy
| | - Giulia Frisso
- CEINGE-Biotecnologie Avanzate s.c.a r.l.,Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli 'Federico II'
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Li W, Yin L, Shen C, Hu K, Ge J, Sun A. SCN5A Variants: Association With Cardiac Disorders. Front Physiol 2018; 9:1372. [PMID: 30364184 PMCID: PMC6191725 DOI: 10.3389/fphys.2018.01372] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 09/10/2018] [Indexed: 12/19/2022] Open
Abstract
The SCN5A gene encodes the alpha subunit of the main cardiac sodium channel Nav1.5. This channel predominates inward sodium current (INa) and plays a critical role in regulation of cardiac electrophysiological function. Since 1995, SCN5A variants have been found to be causatively associated with Brugada syndrome, long QT syndrome, cardiac conduction system dysfunction, dilated cardiomyopathy, etc. Previous genetic, electrophysiological, and molecular studies have identified the arrhythmic and cardiac structural characteristics induced by SCN5A variants. However, due to the variation of disease manifestations and genetic background, impact of environmental factors, as well as the presence of mixed phenotypes, the detailed and individualized physiological mechanisms in various SCN5A-related syndromes are not fully elucidated. This review summarizes the current knowledge of SCN5A genetic variations in different SCN5A-related cardiac disorders and the newly developed therapy strategies potentially useful to prevent and treat these disorders in clinical setting.
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Affiliation(s)
- Wenjia Li
- Department of Cardiology, Shanghai Institute of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Lei Yin
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University, Shanghai, China
| | - Cheng Shen
- Department of Cardiology, The Affiliated Hospital of Jining Medical University, Jining, China
| | - Kai Hu
- Department of Cardiology, Shanghai Institute of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Junbo Ge
- Department of Cardiology, Shanghai Institute of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai, China.,Department of Cardiology, Institute of Biomedical Science, Fudan University, Shanghai, China
| | - Aijun Sun
- Department of Cardiology, Shanghai Institute of Cardiovascular Disease, Zhongshan Hospital, Fudan University, Shanghai, China.,Department of Cardiology, Institute of Biomedical Science, Fudan University, Shanghai, China
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Moreau A, Chahine M. A New Cardiac Channelopathy: From Clinical Phenotypes to Molecular Mechanisms Associated With Na v1.5 Gating Pores. Front Cardiovasc Med 2018; 5:139. [PMID: 30356750 PMCID: PMC6189448 DOI: 10.3389/fcvm.2018.00139] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/19/2018] [Indexed: 12/19/2022] Open
Abstract
Voltage gated sodium channels (NaV) are broadly expressed in the human body. They are responsible for the initiation of action potentials in excitable cells. They also underlie several physiological processes such as cognitive, sensitive, motor, and cardiac functions. The NaV1.5 channel is the main NaV expressed in the heart. A dysfunction of this channel is usually associated with the development of pure electrical disorders such as long QT syndrome, Brugada syndrome, sinus node dysfunction, atrial fibrillation, and cardiac conduction disorders. However, mutations of Nav1.5 have recently been linked to the development of an atypical clinical entity combining complex arrhythmias and dilated cardiomyopathy. Although several Nav1.5 mutations have been linked to dilated cardiomyopathy phenotypes, their pathogenic mechanisms remain to be elucidated. The gating pore may constitute a common biophysical defect for all NaV1.5 mutations located in the channel's VSDs. The creation of such a gating pore may disrupt the ionic homeostasis of cardiomyocytes, affecting electrical signals, cell morphology, and cardiac myocyte function. The main objective of this article is to review the concept of gating pores and their role in structural heart diseases and to discuss potential pharmacological treatments.
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Affiliation(s)
- Adrien Moreau
- PhyMedExp, Université de Montpellier, INSERM, CNRS, Montpellier, France
| | - Mohamed Chahine
- CERVO Research Centre, Institut Universitaire en Santé Mentale de Québec, Quebec City, QC, Canada.,Department of Medicine, Université Laval, Quebec City, QC, Canada
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32
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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.
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Zakrzewska-Koperska J, Franaszczyk M, Bilińska Z, Truszkowska G, Karczmarz M, Szumowski Ł, Zieliński T, Płoski R, Bilińska M. Rapid and effective response of the R222Q SCN5A to quinidine treatment in a patient with Purkinje-related ventricular arrhythmia and familial dilated cardiomyopathy: a case report. BMC MEDICAL GENETICS 2018; 19:94. [PMID: 29871609 PMCID: PMC5989373 DOI: 10.1186/s12881-018-0599-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 05/01/2018] [Indexed: 11/13/2022]
Abstract
Background Mutations of the SCN5A gene are reported in 2-4% of patients with dilated cardiomyopathy (DCM). In such cases, DCM is associated with different rhythm disturbances such as the multifocal ectopic Purkinje-related premature contractions and atrial fibrillation. Arrhythmia often occurs at a young age and is the first symptom of heart disease. Case presentation We present the case of 55-year old male with a 30-year history of heart failure (HF) in the course of familial DCM and complex ventricular tachyarrhythmias, which constituted 50-80% of the whole rhythm. The patient was qualified for heart transplantation because of the increasing symptoms of HF. We revealed the heterozygotic R222Q mutation in SCN5A by means of whole exome sequencing. After the quinidine treatment, a rapid and significant reduction of ventricular tachyarrhythmias and an improvement in the myocardial function were observed and this effect remained constant in the 2.5-year follow-up. This effect was observed even in the presence of concomitant coronary artery disease. Conclusions Patients with familial DCM and Purkinje-related ventricular arrhythmias should be offered genetic screening. The quinidine treatment for the SCN5A R222Q mutation can be life saving for patients.
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Affiliation(s)
| | - Maria Franaszczyk
- Molecular Biology Laboratory, Department of Medical Biology, Institute of Cardiology, ul. Alpejska 42, 04-628, Warszawa, Poland
| | - Zofia Bilińska
- Unit for Screening Studies in Inherited Cardiovascular Diseases, Institute of Cardiology, ul. Alpejska 42, 04-628, Warszawa, Poland.
| | - Grażyna Truszkowska
- Molecular Biology Laboratory, Department of Medical Biology, Institute of Cardiology, ul. Alpejska 42, 04-628, Warszawa, Poland
| | - Małgorzata Karczmarz
- Department of Heart Failure and Transplantology, Institute of Cardiology, ul. Alpejska 42, 04-628, Warszawa, Poland
| | - Łukasz Szumowski
- Department of Arrhythmia, Institute of Cardiology, ul. Alpejska 42, 04-628, Warszawa, Poland
| | - Tomasz Zieliński
- Department of Heart Failure and Transplantology, Institute of Cardiology, ul. Alpejska 42, 04-628, Warszawa, Poland
| | - Rafał Płoski
- Department of Medical Genetics, Medical University of Warsaw, ul. Pawinskiego 3c, 02-106, Warszawa, Poland.
| | - Maria Bilińska
- Department of Arrhythmia, Institute of Cardiology, ul. Alpejska 42, 04-628, Warszawa, Poland
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Held K, Gruss F, Aloi VD, Janssens A, Ulens C, Voets T, Vriens J. Mutations in the voltage-sensing domain affect the alternative ion permeation pathway in the TRPM3 channel. J Physiol 2018; 596:2413-2432. [PMID: 29604058 PMCID: PMC6002228 DOI: 10.1113/jp274124] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 03/19/2018] [Indexed: 01/23/2023] Open
Abstract
Key points Mutagenesis at positively charged amino acids (arginines and lysines) (R1–R4) in the voltage‐sensor domain (transmembrane segment (S) 4) of voltage‐gated Na+, K+ and Ca2+ channels can lead to an alternative ion permeation pathway distinct from the central pore. Recently, a non‐canonical ion permeation pathway was described in TRPM3, a member of the transient receptor potential (TRP) superfamily. The non‐canonical pore exists in the native TRPM3 channel and can be activated by co‐stimulation of the endogenous agonist pregnenolone sulphate and the antifungal drug clotrimazole or by stimulation of the synthetic agonist CIM0216. Alignment of the voltage sensor of Shaker K+ channels with the entire TRPM3 sequence revealed the highest degree of similarity in the putative S4 region of TRPM3, and suggested that only one single gating charge arginine (R2) in the putative S4 region is conserved. Mutagenesis studies in the voltage‐sensing domain of TRPM3 revealed several residues in the voltage sensor (S4) as well as in S1 and S3 that are crucial for the occurrence of the non‐canonical inward currents. In conclusion, this study provides evidence for the involvement of the voltage‐sensing domain of TRPM3 in the formation of an alternative ion permeation pathway.
Abstract Transient receptor potential (TRP) channels are cationic channels involved in a broad array of functions, including homeostasis, motility and sensory functions. TRP channel subunits consist of six transmembrane segments (S1–S6), and form tetrameric channels with a central pore formed by the region encompassing S5 and S6. Recently, evidence was provided for the existence of an alternative ion permeation pathway in TRPM3, which allows large inward currents upon hyperpolarization independently of the central pore. However, very little knowledge is available concerning the localization of this alternative pathway in the native TRPM3 channel protein. Guided by sequence homology with Shaker K+ channels, in which mutations in S4 can create an analogous ‘omega’ pore, we performed site‐directed mutagenesis studies and patch clamp experiments to identify amino acid residues involved in the formation of the non‐canonical pore in TRPM3. Based on our results, we pinpoint four residues in S4 (W982, R985, D988 and G991) as crucial determinants of the properties of the alternative ion permeation pathway. Mutagenesis at positively charged amino acids (arginines and lysines) (R1–R4) in the voltage‐sensor domain (transmembrane segment (S) 4) of voltage‐gated Na+, K+ and Ca2+ channels can lead to an alternative ion permeation pathway distinct from the central pore. Recently, a non‐canonical ion permeation pathway was described in TRPM3, a member of the transient receptor potential (TRP) superfamily. The non‐canonical pore exists in the native TRPM3 channel and can be activated by co‐stimulation of the endogenous agonist pregnenolone sulphate and the antifungal drug clotrimazole or by stimulation of the synthetic agonist CIM0216. Alignment of the voltage sensor of Shaker K+ channels with the entire TRPM3 sequence revealed the highest degree of similarity in the putative S4 region of TRPM3, and suggested that only one single gating charge arginine (R2) in the putative S4 region is conserved. Mutagenesis studies in the voltage‐sensing domain of TRPM3 revealed several residues in the voltage sensor (S4) as well as in S1 and S3 that are crucial for the occurrence of the non‐canonical inward currents. In conclusion, this study provides evidence for the involvement of the voltage‐sensing domain of TRPM3 in the formation of an alternative ion permeation pathway.
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Affiliation(s)
- Katharina Held
- Laboratory of Experimental Gynecology and G-PURE, KU Leuven, Department of Development and Regeneration, Herestraat 49 box 611, B-3000, Leuven, Belgium.,Laboratory of Ion Channel Research and TRP Research Platform Leuven (TRPLe), KU Leuven, Department of Cellular and Molecular Medicine, Herestraat 49 box 802, B-3000, Leuven, Belgium.,VIB Center for Brain & Disease Research, B-3000, Leuven, Belgium
| | - Fabian Gruss
- Laboratory of Structural Neurobiology and TRP Research Platform Leuven (TRPLe), KU Leuven, Department of Cellular and Molecular Medicine, Herestraat 49 box 601, B-3000, Leuven, Belgium
| | - Vincenzo Davide Aloi
- Laboratory of Experimental Gynecology and G-PURE, KU Leuven, Department of Development and Regeneration, Herestraat 49 box 611, B-3000, Leuven, Belgium.,Laboratory of Ion Channel Research and TRP Research Platform Leuven (TRPLe), KU Leuven, Department of Cellular and Molecular Medicine, Herestraat 49 box 802, B-3000, Leuven, Belgium.,VIB Center for Brain & Disease Research, B-3000, Leuven, Belgium
| | - Annelies Janssens
- Laboratory of Ion Channel Research and TRP Research Platform Leuven (TRPLe), KU Leuven, Department of Cellular and Molecular Medicine, Herestraat 49 box 802, B-3000, Leuven, Belgium.,VIB Center for Brain & Disease Research, B-3000, Leuven, Belgium
| | - Chris Ulens
- Laboratory of Structural Neurobiology and TRP Research Platform Leuven (TRPLe), KU Leuven, Department of Cellular and Molecular Medicine, Herestraat 49 box 601, B-3000, Leuven, Belgium
| | - Thomas Voets
- Laboratory of Ion Channel Research and TRP Research Platform Leuven (TRPLe), KU Leuven, Department of Cellular and Molecular Medicine, Herestraat 49 box 802, B-3000, Leuven, Belgium.,VIB Center for Brain & Disease Research, B-3000, Leuven, Belgium
| | - Joris Vriens
- Laboratory of Experimental Gynecology and G-PURE, KU Leuven, Department of Development and Regeneration, Herestraat 49 box 611, B-3000, Leuven, Belgium
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Multifocal ectopic Purkinje-related premature contractions: Sorting the wheat from the chaff. Int J Cardiol 2018; 257:218-219. [DOI: 10.1016/j.ijcard.2018.01.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 01/10/2018] [Indexed: 11/21/2022]
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36
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Chahine M. Improving the characterization of calcium channel gating pore currents with Stac3. J Gen Physiol 2018; 150:375-378. [PMID: 29467165 PMCID: PMC5839726 DOI: 10.1085/jgp.201711984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Chahine highlights new work that exploits the increased expression of human CaV1.1 at the plasma membrane after coexpression with Stac3.
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37
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Wu F, Quinonez M, DiFranco M, Cannon SC. Stac3 enhances expression of human Ca V1.1 in Xenopus oocytes and reveals gating pore currents in HypoPP mutant channels. J Gen Physiol 2018; 150:475-489. [PMID: 29386226 PMCID: PMC5839724 DOI: 10.1085/jgp.201711962] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 01/03/2018] [Indexed: 01/24/2023] Open
Abstract
Hypokalemic periodic paralysis (HypoPP) is thought to be caused by an aberrant inward current through the voltage sensors of mutant Na+ or Ca2+ channels. Wu et al. use Stac3 to enhance the membrane expression of two HypoPP CaV1.1 mutants in oocytes and find that both support gating pore currents. Mutations of CaV1.1, the pore-forming subunit of the L-type Ca2+ channel in skeletal muscle, are an established cause of hypokalemic periodic paralysis (HypoPP). However, functional assessment of HypoPP mutant channels has been hampered by difficulties in achieving sufficient plasma membrane expression in cells that are not of muscle origin. In this study, we show that coexpression of Stac3 dramatically increases the expression of human CaV1.1 (plus α2-δ1b and β1a subunits) at the plasma membrane of Xenopus laevis oocytes. In voltage-clamp studies with the cut-open oocyte clamp, we observe ionic currents on the order of 1 μA and gating charge displacements of ∼0.5–1 nC. Importantly, this high expression level is sufficient to ascertain whether HypoPP mutant channels are leaky because of missense mutations at arginine residues in S4 segments of the voltage sensor domains. We show that R528H and R528G in S4 of domain II both support gating pore currents, but unlike other R/H HypoPP mutations, R528H does not conduct protons. Stac3-enhanced membrane expression of CaV1.1 in oocytes increases the throughput for functional studies of disease-associated mutations and is a new platform for investigating the voltage-dependent properties of CaV1.1 without the complexity of the transverse tubule network in skeletal muscle.
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Affiliation(s)
- Fenfen Wu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Marbella Quinonez
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Marino DiFranco
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Stephen C Cannon
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
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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.
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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
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39
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Animal toxins for channelopathy treatment. Neuropharmacology 2017; 132:83-97. [PMID: 29080794 DOI: 10.1016/j.neuropharm.2017.10.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 10/09/2017] [Accepted: 10/24/2017] [Indexed: 12/18/2022]
Abstract
Ion channels are transmembrane proteins that allow passive flow of ions inside and/or outside of cells or cell organelles. Except mutations lead to nonfunctional protein production or abolished receptor entrance on the membrane surface an altered channel may have two principal conditions that can be corrected. The channel may conduct fewer ions through (loss-of-function mutations) or too many ions (gain-of-function mutations) compared to a normal channel. Toxins from animal venoms are specialised molecules that are generally oriented toward interactions with ion channels. This is a result of long coevolution between predators and their prey. On the molecular level, toxins activate or inhibit ion channels, so they are ideal molecules for restoring conductance in mutated channels. Another aspect of this long coevolution is that a broad variety of toxins have been fine tuned to recognize the channels of different species, keeping many amino acids substitution among sequences. Many peptide ligands with high selectivity to specific receptor subtypes have been isolated from animal venoms, some of which are absolutely non-toxic to humans and mammalians. It is expected that molecules that are selective to each known receptor can be found in animal venoms, but the pool of toxins currently does not override all receptors described as being involved in channelopathies. Modern investigating methods have enhanced the search process for selective ligands. One prominent method is a site-directed mutagenesis of existing toxins to change the selectivity or/and affinity to the selected receptor, which has shown positive results. This article is part of the Special Issue entitled 'Channelopathies.'
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40
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Roston TM, Cunningham T, Lehman A, Laksman ZW, Krahn AD, Sanatani S. Beyond the Electrocardiogram: Mutations in Cardiac Ion Channel Genes Underlie Nonarrhythmic Phenotypes. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2017; 11:1179546817698134. [PMID: 28469493 PMCID: PMC5392026 DOI: 10.1177/1179546817698134] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 02/01/2017] [Indexed: 12/19/2022]
Abstract
Cardiac ion channelopathies are an important cause of sudden death in the young and include long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, idiopathic ventricular fibrillation, and short QT syndrome. Genes that encode ion channels have been implicated in all of these conditions, leading to the widespread implementation of genetic testing for suspected channelopathies. Over the past half-century, researchers have also identified systemic pathologies that extend beyond the arrhythmic phenotype in patients with ion channel gene mutations, including deafness, epilepsy, cardiomyopathy, periodic paralysis, and congenital heart disease. A coexisting phenotype, such as cardiomyopathy, can influence evaluation and management. However, prior to recent molecular advances, our understanding and recognition of these overlapping phenotypes were poor. This review highlights the systemic and structural heart manifestations of the cardiac ion channelopathies, including their phenotypic spectrum and molecular basis.
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Affiliation(s)
- Thomas M Roston
- British Columbia Inherited Arrhythmia Program and University of British Columbia, Vancouver, BC, Canada
| | - Taylor Cunningham
- British Columbia Inherited Arrhythmia Program and University of British Columbia, Vancouver, BC, Canada
| | - Anna Lehman
- British Columbia Inherited Arrhythmia Program and University of British Columbia, Vancouver, BC, Canada
| | - Zachary W Laksman
- British Columbia Inherited Arrhythmia Program and University of British Columbia, Vancouver, BC, Canada
| | - Andrew D Krahn
- British Columbia Inherited Arrhythmia Program and University of British Columbia, Vancouver, BC, Canada
| | - Shubhayan Sanatani
- British Columbia Inherited Arrhythmia Program and University of British Columbia, Vancouver, BC, Canada.,Children's Heart Centre, BC Children's Hospital, Vancouver, BC, Canada
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41
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Moreau A, Mercier A, Thériault O, Boutjdir M, Burger B, Keller DI, Chahine M. Biophysical, Molecular, and Pharmacological Characterization of Voltage-Dependent Sodium Channels From Induced Pluripotent Stem Cell-Derived Cardiomyocytes. Can J Cardiol 2017; 33:269-278. [DOI: 10.1016/j.cjca.2016.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 10/03/2016] [Accepted: 10/05/2016] [Indexed: 12/16/2022] Open
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42
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Wood ML, Freites JA, Tombola F, Tobias DJ. Atomistic Modeling of Ion Conduction through the Voltage-Sensing Domain of the Shaker K + Ion Channel. J Phys Chem B 2017; 121:3804-3812. [PMID: 28074656 DOI: 10.1021/acs.jpcb.6b12639] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Voltage-sensing domains (VSDs) sense changes in the membrane electrostatic potential and, through conformational changes, regulate a specific function. The VSDs of wild-type voltage-dependent K+, Na+, and Ca2+ channels do not conduct ions, but they can become ion-permeable through pathological mutations in the VSD. Relatively little is known about the underlying mechanisms of conduction through VSDs. The most detailed studies have been performed on Shaker K+ channel variants in which ion conduction through the VSD is manifested in electrophysiology experiments as a voltage-dependent inward current, the so-called omega current, which appears when the VSDs are in their resting state conformation. Only monovalent cations appear to permeate the Shaker VSD via a pathway that is believed to be, at least in part, the same as that followed by the S4 basic side chains during voltage-dependent activation. We performed μs-time scale atomistic molecular dynamics simulations of a cation-conducting variant of the Shaker VSD under applied electric fields in an experimentally validated resting-state conformation, embedded in a lipid bilayer surrounded by solutions containing guanidinium chloride or potassium chloride. Our simulations provide insights into the Shaker VSD permeation pathway, the protein-ion interactions that control permeation kinetics, and the mechanism of voltage-dependent activation of voltage-gated ion channels.
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Affiliation(s)
- Mona L Wood
- Department of Chemistry, University of California Irvine , Irvine, California 92697-2025, United States
| | - J Alfredo Freites
- Department of Chemistry, University of California Irvine , Irvine, California 92697-2025, United States
| | - Francesco Tombola
- Department of Physiology and Biophysics, University of California Irvine , Irvine, California 92697-4560, United States
| | - Douglas J Tobias
- Department of Chemistry, University of California Irvine , Irvine, California 92697-2025, United States
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Exome Sequencing Identifies Compound Heterozygous Mutations in SCN5A Associated with Congenital Complete Heart Block in the Thai Population. DISEASE MARKERS 2016; 2016:3684965. [PMID: 28018021 PMCID: PMC5149683 DOI: 10.1155/2016/3684965] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/18/2016] [Indexed: 12/19/2022]
Abstract
Background. Congenital heart block is characterized by blockage of electrical impulses from the atrioventricular node (AV node) to the ventricles. This blockage can be caused by ion channel impairment that is the result of genetic variation. This study aimed to investigate the possible causative variants in a Thai family with complete heart block by using whole exome sequencing. Methods. Genomic DNA was collected from a family consisting of five family members in three generations in which one of three children in generation III had complete heart block. Whole exome sequencing was performed on one complete heart block affected child and one unaffected sibling. Bioinformatics was used to identify annotated and filtered variants. Candidate variants were validated and the segregation analysis of other family members was performed. Results. This study identified compound heterozygous variants, c.101G>A and c.3832G>A, in the SCN5A gene and c.28730C>T in the TTN gene. Conclusions. Compound heterozygous variants in the SCN5A gene were found in the complete heart block affected child but these two variants were found only in the this affected sibling and were not found in other unaffected family members. Hence, these variants in the SCN5A gene were the most possible disease-causing variants in this family.
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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.
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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
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Zou M, Wang F, Gao R, Wu J, Ou Y, Chen X, Wang T, Zhou X, Zhu W, Li P, Qi LW, Jiang T, Wang W, Li C, Chen J, He Q, Chen Y. Autophagy inhibition of hsa-miR-19a-3p/19b-3p by targeting TGF-β R II during TGF-β1-induced fibrogenesis in human cardiac fibroblasts. Sci Rep 2016; 6:24747. [PMID: 27098600 PMCID: PMC4838850 DOI: 10.1038/srep24747] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 03/31/2016] [Indexed: 02/08/2023] Open
Abstract
Transforming growth factor-β1 (TGF-β1) plays an important role on fibrogenesis in heart disease. MicroRNAs have exhibited as crucial regulators of cardiac homeostasis and remodeling in various heart diseases. MiR-19a-3p/19b-3p expresses with low levels in the plasma of heart failure patients. The purpose of our study is to determine the role of MiR-19a-3p/19b-3p in regulating autophagy-mediated fibrosis of human cardiac fibroblasts. We elucidate our hypothesis in clinical samples and human cardiac fibroblasts (HCF) to provide valuable basic information. TGF-β1 promotes collagen I α2 and fibronectin synthesis in HCF and that is paralleled by autophagic activation in these cells. Pharmacological inhibition of autophagy by 3-methyladenine decreases the fibrotic response, while autophagy induction of rapamycin increases the response. BECN1 knockdown and Atg5 over-expression either inhibits or enhances the fibrotic effect of TGF-β1 in experimental HCF. Furthermore, miR-19a-3p/19b-3p mimics inhibit epithelial mesenchymal transition (EMT) and extracellular matrix (ECM) prodution and invasion of HCF. Functional studies suggest that miR-19a-3p/19b-3p inhibits autophagy of HCF through targeting TGF-β R II mRNA. Moreover, enhancement of autophagy rescues inhibition effect of miR-19a-3p/19b-3p on Smad 2 and Akt phosphorylation through TGF-β R II signaling. Our study uncovers a novel mechanism that miR-19a-3p/19b-3p inhibits autophagy-mediated fibrogenesis by targeting TGF-β R II.
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Affiliation(s)
- Meijuan Zou
- Department of Pharmacology, School of Basic Medical Sciences, Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029, P.R. China
| | - Fang Wang
- Department of Cardiology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
| | - Rui Gao
- Department of Pharmacology, School of Basic Medical Sciences, Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029, P.R. China
| | - Jingjing Wu
- Department Of Nephrology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
| | - Yingwei Ou
- Department of Pharmacology, School of Basic Medical Sciences, Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029, P.R. China
| | - Xuguan Chen
- Department of Pharmacology, School of Basic Medical Sciences, Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029, P.R. China
| | - Tongshan Wang
- Department of Oncology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
| | - Xin Zhou
- Department of Oncology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
| | - Wei Zhu
- Department of Oncology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
| | - Ping Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Lian-Wen Qi
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Ting Jiang
- Emergency Center, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
| | - Weiwei Wang
- Emergency Center, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
| | - Chunyu Li
- Emergency Center, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
| | - Jun Chen
- Emergency Center, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
| | - Qifang He
- Emergency Center, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
| | - Yan Chen
- Emergency Center, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, P.R. China
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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.
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Affiliation(s)
- Adrien Moreau
- a Centre de Recherche ; Institut Universitaire en Santé Mentale de Québec ; Quebec City , QC Canada
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Wang HG, Zhu W, Kanter RJ, Silva JR, Honeywell C, Gow RM, Pitt GS. A novel NaV1.5 voltage sensor mutation associated with severe atrial and ventricular arrhythmias. J Mol Cell Cardiol 2016; 92:52-62. [PMID: 26801742 PMCID: PMC4789166 DOI: 10.1016/j.yjmcc.2016.01.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 01/12/2016] [Accepted: 01/13/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND Inherited autosomal dominant mutations in cardiac sodium channels (NaV1.5) cause various arrhythmias, such as long QT syndrome and Brugada syndrome. Although dozens of mutations throughout the protein have been reported, there are few reported mutations within a voltage sensor S4 transmembrane segment and few that are homozygous. Here we report analysis of a novel lidocaine-sensitive recessive mutation, p.R1309H, in the NaV1.5 DIII/S4 voltage sensor in a patient with a complex arrhythmia syndrome. METHODS AND RESULTS We expressed the wild type or mutant NaV1.5 heterologously for analysis with the patch-clamp and voltage clamp fluorometry (VCF) techniques. p.R1309H depolarized the voltage-dependence of activation, hyperpolarized the voltage-dependence of inactivation, and slowed recovery from inactivation, thereby reducing the channel availability at physiologic membrane potentials. Additionally, p.R1309H increased the "late" Na(+) current. The location of the mutation in DIIIS4 prompted testing for a gating pore current. We observed an inward current at hyperpolarizing voltages that likely exacerbates the loss-of-function defects at resting membrane potentials. Lidocaine reduced the gating pore current. CONCLUSIONS The p.R1309H homozygous NaV1.5 mutation conferred both gain-of-function and loss-of-function effects on NaV1.5 channel activity. Reduction of a mutation-induced gating pore current by lidocaine suggested a therapeutic mechanism.
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Affiliation(s)
- Hong-Gang Wang
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC, United States; Ion Channel Research Unit, Duke University Medical Center, Durham, NC, United States
| | - Wandi Zhu
- Department of Biomedical Engineering, Washington University in St. Louis, United States
| | - Ronald J Kanter
- Division of Cardiology, Nicklaus Children's Hospital, Miami, FL, United States
| | - Jonathan R Silva
- Department of Biomedical Engineering, Washington University in St. Louis, United States
| | - Christina Honeywell
- Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Canada
| | - Robert M Gow
- Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Canada
| | - Geoffrey S Pitt
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC, United States; Ion Channel Research Unit, Duke University Medical Center, Durham, NC, United States; Department of Neurobiology, Duke University Medical Center, Durham, NC, United States.
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Loussouarn G, Sternberg D, Nicole S, Marionneau C, Le Bouffant F, Toumaniantz G, Barc J, Malak OA, Fressart V, Péréon Y, Baró I, Charpentier F. Physiological and Pathophysiological Insights of Nav1.4 and Nav1.5 Comparison. Front Pharmacol 2016; 6:314. [PMID: 26834636 PMCID: PMC4712308 DOI: 10.3389/fphar.2015.00314] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 12/21/2015] [Indexed: 12/19/2022] Open
Abstract
Mutations in Nav1.4 and Nav1.5 α-subunits have been associated with muscular and cardiac channelopathies, respectively. Despite intense research on the structure and function of these channels, a lot of information is still missing to delineate the various physiological and pathophysiological processes underlying their activity at the molecular level. Nav1.4 and Nav1.5 sequences are similar, suggesting structural and functional homologies between the two orthologous channels. This also suggests that any characteristics described for one channel subunit may shed light on the properties of the counterpart channel subunit. In this review article, after a brief clinical description of the muscular and cardiac channelopathies related to Nav1.4 and Nav1.5 mutations, respectively, we compare the knowledge accumulated in different aspects of the expression and function of Nav1.4 and Nav1.5 α-subunits: the regulation of the two encoding genes (SCN4A and SCN5A), the associated/regulatory proteins and at last, the functional effect of the same missense mutations detected in Nav1.4 and Nav1.5. First, it appears that more is known on Nav1.5 expression and accessory proteins. Because of the high homologies of Nav1.5 binding sites and equivalent Nav1.4 sites, Nav1.5-related results may guide future investigations on Nav1.4. Second, the analysis of the same missense mutations in Nav1.4 and Nav1.5 revealed intriguing similarities regarding their effects on membrane excitability and alteration in channel biophysics. We believe that such comparison may bring new cues to the physiopathology of cardiac and muscular diseases.
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Affiliation(s)
- Gildas Loussouarn
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Damien Sternberg
- Institut National de la Santé et de la Recherche Médicale, U1127Paris, France; Sorbonne Universités, Université Pierre-et-Marie-Curie, UMR S1127Paris, France; Centre National de la Recherche Scientifique, UMR 7225Paris, France; Institut du Cerveau et de la Moelle Épinière, ICMParis, France; Assistance Publique - Hôpitaux de Paris (AP-HP), Centres de Référence des Canalopathies Musculaires et des Maladies Neuro-musculaires Paris-EstParis, France; Assistance Publique - Hôpitaux de Paris (AP-HP), Hôpital de la Pitié Salpêtrière, Service de Biochimie Métabolique, Unité de Cardiogénétique et MyogénétiqueParis, France
| | - Sophie Nicole
- Institut National de la Santé et de la Recherche Médicale, U1127Paris, France; Sorbonne Universités, Université Pierre-et-Marie-Curie, UMR S1127Paris, France; Centre National de la Recherche Scientifique, UMR 7225Paris, France; Institut du Cerveau et de la Moelle Épinière, ICMParis, France
| | - Céline Marionneau
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Francoise Le Bouffant
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Gilles Toumaniantz
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Julien Barc
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Olfat A Malak
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Véronique Fressart
- Assistance Publique - Hôpitaux de Paris (AP-HP), Hôpital de la Pitié Salpêtrière, Service de Biochimie Métabolique, Unité de Cardiogénétique et Myogénétique Paris, France
| | - Yann Péréon
- Centre Hospitalier Universitaire de Nantes, Centre de Référence Maladies Neuromusculaires Nantes-AngersNantes, France; Atlantic Gene Therapies - Biotherapy Institute for Rare DiseasesNantes, France
| | - Isabelle Baró
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Flavien Charpentier
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France; Centre Hospitalier Universitaire de Nantes, l'Institut du ThoraxNantes, France
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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]
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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.
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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
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