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Zaytseva AK, Kulichik OE, Kostareva AA, Zhorov BS. Biophysical mechanisms of myocardium sodium channelopathies. Pflugers Arch 2024; 476:735-753. [PMID: 38424322 DOI: 10.1007/s00424-024-02930-3] [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: 09/28/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 03/02/2024]
Abstract
Genetic variants of gene SCN5A encoding the alpha-subunit of cardiac voltage-gated sodium channel Nav1.5 are associated with various diseases, including long QT syndrome (LQT3), Brugada syndrome (BrS1), and progressive cardiac conduction disease (PCCD). In the last decades, the great progress in understanding molecular and biophysical mechanisms of these diseases has been achieved. The LQT3 syndrome is associated with gain-of-function of sodium channels Nav1.5 due to impaired inactivation, enhanced activation, accelerated recovery from inactivation or the late current appearance. In contrast, BrS1 and PCCD are associated with the Nav1.5 loss-of-function, which in electrophysiological experiments can be manifested as reduced current density, enhanced fast or slow inactivation, impaired activation, or decelerated recovery from inactivation. Genetic variants associated with congenital arrhythmias can also disturb interactions of the Nav1.5 channel with different proteins or drugs and cause unexpected reactions to drug administration. Furthermore, mutations can affect post-translational modifications of the channels and their sensitivity to pH and temperature. Here we briefly review the current knowledge on biophysical mechanisms of LQT3, BrS1 and PCCD. We focus on limitations of studies that use heterologous expression systems and induced pluripotent stem cells (iPSC) derived cardiac myocytes and summarize our understanding of genotype-phenotype relations of SCN5A mutations.
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Affiliation(s)
- 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.
| | - Olga E Kulichik
- Almazov National Medical Research Centre, St. Petersburg, Russia
| | | | - 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
- McMaster University, Hamilton, Canada
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2
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Liantonio A, Bertini M, Mele A, Balla C, Dinoi G, Selvatici R, Mele M, De Luca A, Gualandi F, Imbrici P. Brugada Syndrome: More than a Monogenic Channelopathy. Biomedicines 2023; 11:2297. [PMID: 37626795 PMCID: PMC10452102 DOI: 10.3390/biomedicines11082297] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/10/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
Brugada syndrome (BrS) is an inherited cardiac channelopathy first diagnosed in 1992 but still considered a challenging disease in terms of diagnosis, arrhythmia risk prediction, pathophysiology and management. Despite about 20% of individuals carrying pathogenic variants in the SCN5A gene, the identification of a polygenic origin for BrS and the potential role of common genetic variants provide the basis for applying polygenic risk scores for individual risk prediction. The pathophysiological mechanisms are still unclear, and the initial thinking of this syndrome as a primary electrical disease is evolving towards a partly structural disease. This review focuses on the main scientific advancements in the identification of biomarkers for diagnosis, risk stratification, pathophysiology and therapy of BrS. A comprehensive model that integrates clinical and genetic factors, comorbidities, age and gender, and perhaps environmental influences may provide the opportunity to enhance patients' quality of life and improve the therapeutic approach.
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Affiliation(s)
- Antonella Liantonio
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (A.L.); (A.M.); (G.D.); (M.M.); (A.D.L.)
| | - Matteo Bertini
- Cardiological Center, Sant’Anna University Hospital of Ferrara, 44121 Ferrara, Italy; (M.B.); (C.B.)
| | - Antonietta Mele
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (A.L.); (A.M.); (G.D.); (M.M.); (A.D.L.)
| | - Cristina Balla
- Cardiological Center, Sant’Anna University Hospital of Ferrara, 44121 Ferrara, Italy; (M.B.); (C.B.)
| | - Giorgia Dinoi
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (A.L.); (A.M.); (G.D.); (M.M.); (A.D.L.)
| | - Rita Selvatici
- Medical Genetics Unit, Department of Mother and Child, Sant’Anna University Hospital of Ferrara, 44121 Ferrara, Italy;
| | - Marco Mele
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (A.L.); (A.M.); (G.D.); (M.M.); (A.D.L.)
- Cardiothoracic Department, Policlinico Riuniti Foggia, 71122 Foggia, Italy
| | - Annamaria De Luca
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (A.L.); (A.M.); (G.D.); (M.M.); (A.D.L.)
| | - Francesca Gualandi
- Medical Genetics Unit, Department of Mother and Child, Sant’Anna University Hospital of Ferrara, 44121 Ferrara, Italy;
| | - Paola Imbrici
- Department of Pharmacy-Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy; (A.L.); (A.M.); (G.D.); (M.M.); (A.D.L.)
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3
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Zhu J, Shen Y, Xiong H, Zha H, Zhang L, Peng H, Tian L. Identification of a novel missense SCN5A mutation in a Chinese Han family with Brugada syndrome. Biochem Biophys Res Commun 2023; 649:55-61. [PMID: 36745970 DOI: 10.1016/j.bbrc.2023.01.026] [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: 12/07/2022] [Revised: 12/16/2022] [Accepted: 01/10/2023] [Indexed: 01/13/2023]
Abstract
Brugada syndrome is an inherited cardiac arrythmia causes sudden death usually associated with loss-of-function mutations of SCN5A, a gene encodes α subunit of cardiac sodium channel Nav1.5 which plays key role in cardiac function. SCN5A mutation screen is often applied to diagnosis of Brugada syndrome, while its genetic etiology remains not fully understood. In present study, we performed sequence analysis of SCN5A gene in a Chinese Han family with Brugada syndrome, and found a novel heterozygous mutation (c.4969 C > T, p.Leu1657Phe). Functional electrophysiological study showed that the mutation reduced ∼60% sodium current density and largely reduced Nav1.5 activation (positively shifted activation curve by 13.93 mV), which are the key features for the pathogenesis of Brugada syndrome. However, the mutation enhanced Nav1.5 function as it slightly decreased inactivation (positively shifted inactivation curve by 7.4 mV) and accelerated recovery (decreased fast recovery by 1.39 ms). In addition, the mutation acts in a dominant negatively manner as it reduced ∼49% sodium current densities in heterozygous state. In conclusion, the study describes a novel SCN5A mutation of p.Leu1657Phe associated with Brugada syndrome, the mutation reduced current density in a dominant negative manner and altered gating kinetics, which will benefit early clinical diagnosis of Brugada syndrome.
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Affiliation(s)
- Jianfang Zhu
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, PR China
| | - Ya Shen
- Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430019, PR China
| | - Hongbo Xiong
- Department of Cardiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, PR China
| | - Hui Zha
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, PR China
| | - Ling Zhang
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, PR China
| | - Hua Peng
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, PR China
| | - Li Tian
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, PR China.
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Satish H, Reddy MR. Reentry in cardiac ventricular epicardial tissue due to SCN5A L812Q gene mutation: a computational study. Biomed Phys Eng Express 2022; 8. [PMID: 35320795 DOI: 10.1088/2057-1976/ac605c] [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: 11/22/2021] [Accepted: 03/23/2022] [Indexed: 11/11/2022]
Abstract
Cardiovascular diseases are the major cause of sudden death. Brugada syndrome is an inherited rare disease, that leads to death due to ventricular fibrillation (VF). Brugada Syndrome is related to mutations in the genes that encode SCN5A, a subunit of sodium ion channel (NaV). This computational study investigates the mechanism of loss of function gene mutation (SCN5A L812Q) in sodium ion channel that leads to spiral wave and further develops into VF in an epicardial tissue with homozygous condition. Study was made on wild type, L812Q heterozygous mutated and homozygous mutated ventricular tissues. Ten Tusscher human ventricular cell model (TP06) was used for the simulation study. VF is developed when a spiral wave that causes ventricular arrhythmia breaks. This leads to the formation of multiple spiral waves that are activated on different regions of the ventricles called wave break. This is observed in the epicardial tissue with homozygous condition as the effect of SCN5A L812Q gene mutation. This indicates that VF occurs in the SCN5A L812Q gene mutated homozygous ventricular epicardial tissue that may further lead to Brugada syndrome.
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Affiliation(s)
- Helan Satish
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - M Ramasubba Reddy
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
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Patterson Rosa L, Mallicote MF, MacKay RJ, Brooks SA. Ion Channel and Ubiquitin Differential Expression during Erythromycin-Induced Anhidrosis in Foals. Animals (Basel) 2021; 11:3379. [PMID: 34944156 PMCID: PMC8697959 DOI: 10.3390/ani11123379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 11/16/2021] [Accepted: 11/24/2021] [Indexed: 11/24/2022] Open
Abstract
Macrolide drugs are the treatment of choice for Rhodococcus equi infections, despite severe side-effects temporary anhidrosis as a. To better understand the molecular biology leading to macrolide induced anhidrosis, we performed skin biopsies and Quantitative Intradermal Terbutaline Sweat Tests (QITSTs) in six healthy pony-cross foals for three different timepoints during erythromycin administration-pre-treatment (baseline), during anhidrosis and post-recovery. RNA sequencing of biopsies followed by differential gene expression analysis compared both pre and post normal sweating timepoints to the erythromycin induced anhidrosis episode. After Bonferroni correction for multiple testing, 132 gene transcripts were significantly differentially expressed during the anhidrotic timepoint. Gene ontology analysis of the full differentially expressed gene set identified over-represented biological functions for ubiquitination and ion-channel function, both biologically relevant to sweat production. These same mechanisms were previously implicated in heritable equine idiopathic anhidrosis and sweat gland function and their involvement in macrolide-induced temporary anhidrosis warrants further investigation.
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Affiliation(s)
- Laura Patterson Rosa
- Department of Animal Sciences, UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA;
- Etalon Diagnostics, Menlo Park, CA 94025, USA
| | - Martha F. Mallicote
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32608, USA; (M.F.M.); (R.J.M.)
| | - Robert J. MacKay
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32608, USA; (M.F.M.); (R.J.M.)
| | - Samantha A. Brooks
- Department of Animal Sciences, UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA;
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Satish H, Reddy M R. A Simulation Study on Electrical Activity of Ventricular Endocardial Tissue due to SCN5A L812Q Mutation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:5543-5546. [PMID: 34892380 DOI: 10.1109/embc46164.2021.9630990] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Brugada Syndrome is a rare arrhythmia, hereditary in nature. It is caused due to mutation in genes that encodes sodium ion channels and it results sudden cardiac death in young adults. This paper aims to model a two dimensional SCN5A L812Q mutated endocardial tissue by modifying the model equations for sodium ion channel in the Ten Tusscher model for human ventricular tissue. Results show that the propagation of electrical activity in the mutated cells is slower when compared to the normal cells of the endocardial tissue. From this it is concluded that there is a large reduction of sodium current in the mutated region of the endocardial tissue. This leads to reduction in the total ionic current as well and further reduces the membrane potential. It also leads to the slower propagation of action potential in the mutated region when compared to the normal endocardial tissue.Clinical Relevance- This establishes the propagation of electrical activity in endocardial tissue for SCN5A L812Q gene mutation that results in arrhythmia called Brugada Syndrome.
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Ji X, Huang Y, Sheng J. Structural modeling of Na v1.5 pore domain in closed state. BIOPHYSICS REPORTS 2021; 7:341-354. [PMID: 37287760 PMCID: PMC10233475 DOI: 10.52601/bpr.2021.200021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 07/21/2021] [Indexed: 06/09/2023] Open
Abstract
The voltage-dependent cardiac sodium channel plays a key role in cardiac excitability and conduction and it is the drug target of medically important. However, its atomic- resolution structure is still lack. Here, we report a modeled structure of Nav1.5 pore domain in closed state. The structure was constructed by Rosetta-membrane homology modeling method based on the template of eukaryotic Nav channel NavPaS and selected by energy and direct coupling analysis (DCA). Moreover, this structure was optimized through molecular dynamical simulation in the lipid membrane bilayer. Finally, to validate the constructed model, the binding energy and binding sites of closed-state local anesthetics (LAs) in the modeled structure were computed by the MM-GBSA method and the results are in agreement with experiments. The modeled structure of Nav1.5 pore domain in closed state may be useful to explore molecular mechanism of a state-dependent drug binding and helpful for new drug development.
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Affiliation(s)
- Xiaofeng Ji
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, Shandong, China
| | - Yanzhao Huang
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jun Sheng
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, Shandong, China
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8
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Rühlmann AH, Körner J, Hausmann R, Bebrivenski N, Neuhof C, Detro-Dassen S, Hautvast P, Benasolo CA, Meents J, Machtens JP, Schmalzing G, Lampert A. Uncoupling sodium channel dimers restores the phenotype of a pain-linked Na v 1.7 channel mutation. Br J Pharmacol 2020; 177:4481-4496. [PMID: 32663327 PMCID: PMC7484505 DOI: 10.1111/bph.15196] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 06/24/2020] [Accepted: 06/27/2020] [Indexed: 12/11/2022] Open
Abstract
Background and Purpose The voltage‐gated sodium channel Nav1.7 is essential for adequate perception of painful stimuli. Mutations in the encoding gene, SCN9A, cause various pain syndromes in humans. The hNav1.7/A1632E channel mutant causes symptoms of erythromelalgia and paroxysmal extreme pain disorder (PEPD), and its main gating change is a strongly enhanced persistent current. On the basis of recently published 3D structures of voltage‐gated sodium channels, we investigated how the inactivation particle binds to the channel, how this mechanism is altered by the hNav1.7/A1632E mutation, and how dimerization modifies function of the pain‐linked mutation. Experimental Approach We applied atomistic molecular simulations to demonstrate the effect of the mutation on channel fast inactivation. Native PAGE was used to demonstrate channel dimerization, and electrophysiological measurements in HEK cells and Xenopus laevis oocytes were used to analyze the links between functional channel dimerization and impairment of fast inactivation by the hNav1.7/A1632E mutation. Key Results Enhanced persistent current through hNav1.7/A1632E channels was caused by impaired binding of the inactivation particle, which inhibits proper functioning of the recently proposed allosteric fast inactivation mechanism. hNav1.7 channels form dimers and the disease‐associated persistent current through hNav1.7/A1632E channels depends on their functional dimerization status: Expression of the synthetic peptide difopein, a 14‐3‐3 inhibitor known to functionally uncouple dimers, decreased hNav1.7/A1632E channel‐induced persistent currents. Conclusion and Implications Functional uncoupling of mutant hNav1.7/A1632E channel dimers restored their defective allosteric fast inactivation mechanism. Our findings support the concept of sodium channel dimerization and reveal its potential relevance for human pain syndromes.
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Affiliation(s)
- Annika H Rühlmann
- Institute of Physiology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany
| | - Jannis Körner
- Institute of Physiology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany.,Department of Anaesthesiology, Medical Faculty, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany
| | - Ralf Hausmann
- Institute of Clinical Pharmacology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany
| | - Nikolay Bebrivenski
- Institute of Clinical Pharmacology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany
| | - Christian Neuhof
- Institute of Clinical Pharmacology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany
| | - Silvia Detro-Dassen
- Institute of Clinical Pharmacology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany
| | - Petra Hautvast
- Institute of Physiology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany
| | - Carène A Benasolo
- Institute of Clinical Pharmacology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany.,Forschungszentrum Jülich, Institute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Jülich, Germany
| | - Jannis Meents
- Institute of Physiology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany
| | - Jan-Philipp Machtens
- Institute of Clinical Pharmacology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany.,Forschungszentrum Jülich, Institute of Biological Information Processing (IBI-1), Molekular- und Zellphysiologie, and JARA-HPC, Jülich, Germany
| | - Günther Schmalzing
- Institute of Clinical Pharmacology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany
| | - Angelika Lampert
- Institute of Physiology, Uniklinik RWTH Aachen University, Pauwelsstrasse 30, Aachen, Deutschland, 52074, Germany
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Zhang W, Zhu B, Ren J, Lu F, Qi Y, Weng W, Gao R. Two methods for modeling of sick sinus syndrome in rats: Ischemia reperfusion and sodium hydroxide induced injury. Biomed Pharmacother 2019; 111:778-784. [PMID: 30612002 DOI: 10.1016/j.biopha.2018.11.091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 11/13/2018] [Accepted: 11/25/2018] [Indexed: 01/23/2023] Open
Abstract
The Sick Sinus Syndrome (SSS) is a serious life-threatening heart disease. It is important to establish a credible and stable sinus node damage model. In this study, we use two methods to construct an SSS damage model in rats. One is to inject sodium hydroxide to the SSS area through internal jugular vein. Another is to cause ischemia-reperfusion injury on the SSS area. 43 healthy SD rats were randomly divided into 4 groups, namely ischemia-reperfusion injury group (IRIG), inject sodium hydroxide group (ISHG), and propranolol group (PG) and the control group (CG). The achievement ratio of modeling was 67% in the IRIG and 83% in the ISHG. The HR significantly decreased after operation in the IRIG and ISHG compared with pre-operation (P<0.01). The HR was reduced by above 30% in these 2 groups after modeling, while the reduction was better maintained in IRIG. Additionally, the sinoatrial node recovery time (SNRT) and sinoatrial conduction time (SACT) were significantly prolonged compared with pre-modeling in 2 groups (P < 0.01). Morphology results showed blurry in structure and boundaries with pale cytoplasm. It is speculated that IRIG and ISHG modeling might influence the calcium concentration and damage the sinus node function by decrease the expression of HCN4 and SCN5A, which impaired the driving ability of sinus node and leading to apoptosis. Ischemia reperfusion injury and sodium hydroxide injury could construct stable SSS models which could represent clinic pathological damage. Thus, both methods could be used for further studies of the SSS mechanisms and drugs.
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Affiliation(s)
- Wantong Zhang
- China Academy of Chinese Medicine Sciences, Xiyuan hospital, 100091, China
| | - Baochen Zhu
- Beijing University of Chinese Medicine, 100029, China
| | - Jianxun Ren
- China Academy of Chinese Medicine Sciences, Xiyuan hospital, 100091, China
| | - Fang Lu
- China Academy of Chinese Medicine Sciences, Xiyuan hospital, 100091, China
| | - Yi Qi
- China Academy of Chinese Medicine Sciences, Xiyuan hospital, 100091, China
| | - Weiliang Weng
- China Academy of Chinese Medicine Sciences, Xiyuan hospital, 100091, China
| | - Rui Gao
- China Academy of Chinese Medicine Sciences, Xiyuan hospital, 100091, China.
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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: 76] [Impact Index Per Article: 12.7] [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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11
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Han D, Tan H, Sun C, Li G. Dysfunctional Nav1.5 channels due to SCN5A mutations. Exp Biol Med (Maywood) 2018; 243:852-863. [PMID: 29806494 DOI: 10.1177/1535370218777972] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The voltage-gated sodium channel 1.5 (Nav1.5), encoded by the SCN5A gene, is responsible for the rising phase of the action potential of cardiomyocytes. The sodium current mediated by Nav1.5 consists of peak and late components (INa-P and INa-L). Mutant Nav1.5 causes alterations in the peak and late sodium current and is associated with an increasingly wide range of congenital arrhythmias. More than 400 mutations have been identified in the SCN5A gene. Although the mechanisms of SCN5A mutations leading to a variety of arrhythmias can be classified according to the alteration of INa-P and INa-L as gain-of-function, loss-of-function and both, few researchers have summarized the mechanisms in this way before. In this review article, we aim to review the mechanisms underlying dysfunctional Nav1.5 due to SCN5A mutations and to provide some new insights into further approaches in the treatment of arrhythmias. Impact statement The field of ion channelopathy caused by dysfunctional Nav1.5 due to SCN5A mutations is rapidly evolving as novel technologies of electrophysiology are introduced and our understanding of the mechanisms of various arrhythmias develops. In this review, we focus on the dysfunctional Nav1.5 related to arrhythmias and the underlying mechanisms. We update SCN5A mutations in a precise way since 2013 and presents novel classifications of SCN5A mutations responsible for the dysfunction of the peak (INa-P) and late (INa-L) sodium channels based on their phenotypes, including loss-, gain-, and coexistence of gain- and loss-of function mutations in INa-P, INa-L, respectively. We hope this review will provide a new comprehensive way to better understand the electrophysiological mechanisms underlying arrhythmias from cell to bedside, promoting the management of various arrhythmias in practice.
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Affiliation(s)
- Dan Han
- 1 Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China
| | - Hui Tan
- 2 Department of Respiratory Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China
| | - Chaofeng Sun
- 1 Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China
| | - Guoliang Li
- 1 Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China
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McMillan B, Gavaghan DJ, Mirams GR. Early afterdepolarisation tendency as a simulated pro-arrhythmic risk indicator. Toxicol Res (Camb) 2017; 6:912-921. [PMID: 29456831 PMCID: PMC5779076 DOI: 10.1039/c7tx00141j] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 09/12/2017] [Indexed: 12/19/2022] Open
Abstract
Drug-induced Torsades de Pointes (TdP) arrhythmia is of major interest in predictive toxicology. Drugs which cause TdP block the hERG cardiac potassium channel. However, not all drugs that block hERG cause TdP. As such, further understanding of the mechanistic route to TdP is needed. Early afterdepolarisations (EADs) are a cell-level phenomenon in which the membrane of a cardiac cell depolarises a second time before repolarisation, and EADs are seen in hearts during TdP. Therefore, we propose a method of predicting TdP using induced EADs combined with multiple ion channel block in simulations using biophysically-based mathematical models of human ventricular cell electrophysiology. EADs were induced in cardiac action potential models using interventions based on diseases that are known to cause EADs, including: increasing the conduction of the L-type calcium channel, decreasing the conduction of the hERG channel, and shifting the inactivation curve of the fast sodium channel. The threshold of intervention that was required to cause an EAD was used to classify drugs into clinical risk categories. The metric that used L-type calcium induced EADs was the most accurate of the EAD metrics at classifying drugs into the correct risk categories, and increased in accuracy when combined with action potential duration measurements. The EAD metrics were all more accurate than hERG block alone, but not as predictive as simpler measures such as simulated action potential duration. This may be because different routes to EADs represent risk well for different patient subgroups, something that is difficult to assess at present.
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Affiliation(s)
- Beth McMillan
- Computational Biology , Dept. of Computer Science , University of Oxford , Oxford , OX1 3QD , UK . ; ; Tel: +44 (0)1865 273838
| | - David J Gavaghan
- Computational Biology , Dept. of Computer Science , University of Oxford , Oxford , OX1 3QD , UK . ; ; Tel: +44 (0)1865 273838
| | - Gary R Mirams
- Centre for Mathematical Biology , School of Mathematical Sciences , University of Nottingham , Nottingham , NG7 2RD , UK
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Ahmed M, Jalily Hasani H, Ganesan A, Houghton M, Barakat K. Modeling the human Na v1.5 sodium channel: structural and mechanistic insights of ion permeation and drug blockade. Drug Des Devel Ther 2017; 11:2301-2324. [PMID: 28831242 PMCID: PMC5552146 DOI: 10.2147/dddt.s133944] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Abnormalities in the human Nav1.5 (hNav1.5) voltage-gated sodium ion channel (VGSC) are associated with a wide range of cardiac problems and diseases in humans. Current structural models of hNav1.5 are still far from complete and, consequently, their ability to study atomistic interactions of this channel is very limited. Here, we report a comprehensive atomistic model of the hNav1.5 ion channel, constructed using homology modeling technique and refined through long molecular dynamics simulations (680 ns) in the lipid membrane bilayer. Our model was comprehensively validated by using reported mutagenesis data, comparisons with previous models, and binding to a panel of known hNav1.5 blockers. The relatively long classical MD simulation was sufficient to observe a natural sodium permeation event across the channel's selectivity filters to reach the channel's central cavity, together with the identification of a unique role of the lysine residue. Electrostatic potential calculations revealed the existence of two potential binding sites for the sodium ion at the outer selectivity filters. To obtain further mechanistic insight into the permeation event from the central cavity to the intracellular region of the channel, we further employed "state-of-the-art" steered molecular dynamics (SMD) simulations. Our SMD simulations revealed two different pathways through which a sodium ion can be expelled from the channel. Further, the SMD simulations identified the key residues that are likely to control these processes. Finally, we discuss the potential binding modes of a panel of known hNav1.5 blockers to our structural model of hNav1.5. We believe that the data presented here will enhance our understanding of the structure-property relationships of the hNav1.5 ion channel and the underlying molecular mechanisms in sodium ion permeation and drug interactions. The results presented here could be useful for designing safer drugs that do not block the hNav1.5 channel.
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Affiliation(s)
| | | | | | - Michael Houghton
- Li Ka Shing Institute of Virology
- Li Ka Shing Applied Virology Institute
- Department of Medical Microbiology and Immunology, Katz Centre for Health Research, University of Alberta, Edmonton, AB, Canada
| | - Khaled Barakat
- Faculty of Pharmacy and Pharmaceutical Sciences
- Li Ka Shing Institute of Virology
- Li Ka Shing Applied Virology Institute
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Bhandare AM, Kapoor K, Farnham MM, Pilowsky PM. Microglia PACAP and glutamate: Friends or foes in seizure-induced autonomic dysfunction and SUDEP? Respir Physiol Neurobiol 2016; 226:39-50. [DOI: 10.1016/j.resp.2016.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 01/18/2016] [Accepted: 01/21/2016] [Indexed: 12/18/2022]
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陈 燕, 刘 深, 谢 亮, 朱 庭, 陈 益, 邓 晓, 孟 素, 彭 健. [Functional analysis of a novel SCN5A mutation G1712C identified in Brugada syndrome]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2016; 37:256-260. [PMID: 28219873 PMCID: PMC6779663 DOI: 10.3969/j.issn.1673-4254.2017.02.19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To elucidate the molecular and electrophysiological mechanisms of Brugada syndrome through functional analysis of a novel SCN5A gene mutation G1712C. METHODS A recombinant plasmid pRc<CMV-hH1 containing the mutant human cardiac sodium channel α subunit (hH1) cDNA was constructed using in vitro PCR-based site-directed mutagenesis technique. LipofectamineTM 3000 was used to transfect the plasmid DNA into HEK293 cell line to induce stable expression of Na+ channel β1-subunit, and the positive colonies were selected by screening with G418.The standard liposome method was used to transiently transfect HEK293 cells with either the wild-type or mutant Na+ channel subunits (hH1 and mhH1, respectively), and the macroscopic Na+ currents were recorded using whole-cell patch-clamp technique. Data acquisition and analysis, generation of voltage commands and curve fitting were accomplished with EPC-10, PatchMaster and IGOR Pro 6.0. RESULTS An HEK293 cell line that stably expressed Na+ channel β1-subunit was successfully established. After transient transfection with the WT subunit, large Na+ currents were recorded from the stable β1-cell line. Transient transfection with the G1712C subunit, however, did not elicit a Na+ current in the cells. CONCLUSION Compared with normal Na+ channel, the wild-type channel exhibits a similar sodium current. The characteristic kinetics of sodium channel of WT-hH1 was identical to that in normal cardiac muscle cell, and the missense mutation (G1712C) in the P-loop region of the domain IV may have caused the failure of sodium channel expression.
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Affiliation(s)
- 燕玉 陈
- />南方医科大学南方医院心内科,广东 广州510515Department of Cardiology, Southern Medical University, Nanfang Hospital, Guangzhou 510515, China
| | - 深荣 刘
- />南方医科大学南方医院心内科,广东 广州510515Department of Cardiology, Southern Medical University, Nanfang Hospital, Guangzhou 510515, China
| | - 亮真 谢
- />南方医科大学南方医院心内科,广东 广州510515Department of Cardiology, Southern Medical University, Nanfang Hospital, Guangzhou 510515, China
| | - 庭延 朱
- />南方医科大学南方医院心内科,广东 广州510515Department of Cardiology, Southern Medical University, Nanfang Hospital, Guangzhou 510515, China
| | - 益臻 陈
- />南方医科大学南方医院心内科,广东 广州510515Department of Cardiology, Southern Medical University, Nanfang Hospital, Guangzhou 510515, China
| | - 晓江 邓
- />南方医科大学南方医院心内科,广东 广州510515Department of Cardiology, Southern Medical University, Nanfang Hospital, Guangzhou 510515, China
| | - 素荣 孟
- />南方医科大学南方医院心内科,广东 广州510515Department of Cardiology, Southern Medical University, Nanfang Hospital, Guangzhou 510515, China
| | - 健 彭
- />南方医科大学南方医院心内科,广东 广州510515Department of Cardiology, Southern Medical University, Nanfang Hospital, Guangzhou 510515, China
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