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Balla C, Margutti A, De Carolis B, Canovi L, Di Domenico A, Vivaldi I, Vitali F, De Raffele M, Malagù M, Sassone B, Biffi M, Selvatici R, Ferlini A, Gualandi F, Bertini M. Cardiac conduction disorders in young adults: Clinical characteristics and genetic background of an underestimated population. Heart Rhythm 2024; 21:1363-1369. [PMID: 38467355 DOI: 10.1016/j.hrthm.2024.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/13/2024]
Abstract
BACKGROUND Cardiac conduction disorder (CCD) in patients <50 years old is a rare and mostly unknown condition. OBJECTIVE We aimed to assess clinical characteristics and genetic background of patients <50 years old with CCD of unknown origin. METHODS We retrospectively reviewed a consecutive series of patients with a diagnosis of CCD before the age of 50 years referred to our center between January 2019 and December 2021. Patients underwent complete clinical examination and genetic evaluation. RESULTS We enrolled 39 patients with a median age of 40 years (28-47 years) at the onset of symptoms. A cardiac implantable electronic device was implanted in 69% of the patients. In 15 of 39 CCD index patients (38%), we found a total of 13 different gene variations (3 pathogenic, 6 likely pathogenic, and 4 variants of uncertain significance), mostly in 3 genes (SCN5A, TRPM4, and LMNA). In our cohort, genetic testing led to the decision to implant an implantable cardioverter-defibrillator in 2 patients for the increased risk of sudden cardiac death. CONCLUSION Patients with the occurrence of CCD before the age of 50 years present with a high rate of pathologic gene variations, mostly in 3 genes (SCN5A, TRPM4, and LMNA). The presence of pathogenic variations may add information about the prognosis and lead to an individualized therapeutic approach.
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Affiliation(s)
- Cristina Balla
- Cardiology Unit, Azienda Ospedaliero-Universitaria di Ferrara, Cona (Ferrara), Italy.
| | - Alice Margutti
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Beatrice De Carolis
- Cardiology Unit, Azienda Ospedaliero-Universitaria di Ferrara, Cona (Ferrara), Italy
| | - Luca Canovi
- Cardiology Unit, Azienda Ospedaliero-Universitaria di Ferrara, Cona (Ferrara), Italy
| | - Assunta Di Domenico
- Cardiology Unit, Azienda Ospedaliero-Universitaria di Ferrara, Cona (Ferrara), Italy
| | - Ilaria Vivaldi
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Francesco Vitali
- Cardiology Unit, Azienda Ospedaliero-Universitaria di Ferrara, Cona (Ferrara), Italy
| | - Martina De Raffele
- Cardiology Unit, Azienda Ospedaliero-Universitaria di Ferrara, Cona (Ferrara), Italy
| | - Michele Malagù
- Cardiology Unit, Azienda Ospedaliero-Universitaria di Ferrara, Cona (Ferrara), Italy
| | - Biagio Sassone
- Division of Cardiology, SS.ma Annunziata Hospital, Department of Emergency, AUSL Ferrara, Cento (Ferrara), Italy
| | - Mauro Biffi
- Cardiology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Rita Selvatici
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Alessandra Ferlini
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Francesca Gualandi
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Matteo Bertini
- Cardiology Unit, Azienda Ospedaliero-Universitaria di Ferrara, Cona (Ferrara), Italy
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2
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Kumar HN, Jeevanandham S, Ganesh MS, Sabana MA, Manivasakam P. Emerging Strategies and Effective Prevention Measures for Investigating the Association Between Stroke and Sudden Cardiac Fatality. Curr Cardiol Rev 2024; 20:35-44. [PMID: 38310557 DOI: 10.2174/011573403x259676231222053709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/19/2023] [Accepted: 11/17/2023] [Indexed: 02/06/2024] Open
Abstract
Stroke-related cardiac death is a significant concern for patients with stroke and their healthcare providers. It is a complex and multifaceted condition that requires careful management of both modifiable and non-modifiable risk factors. This review provides an overview of the pathophysiology, risk factors, and prevention strategies for stroke-related cardiac death. The review highlights the importance of identifying and managing modifiable risk factors such as hypertension, diabetes, and lifestyle factors, as well as non-modifiable risk factors such as age and genetics. Additionally, the review explores emerging strategies for prevention, including the use of wearable devices and genetic testing to identify patients at risk, stem cell therapy and gene therapy for cardiac dysfunction, and precision medicine for personalized treatment plans. Despite some limitations to this review, it provides valuable insights into the current understanding of stroke-related cardiac death and identifies important areas for future research. Ultimately, the implementation of evidence-based prevention strategies and personalized treatment plans has the potential to improve outcomes for patients with stroke and reduce the burden of stroke-related cardiac death in the population.
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Affiliation(s)
- H Nithesh Kumar
- Pharmacy Practice, JKKN College of Pharmacy, Namakkal, India
| | - S Jeevanandham
- Pharmacy Practice, JKKN College of Pharmacy, Namakkal, India
| | | | - M Ashmi Sabana
- Pharmacy Practice, JKKN College of Pharmacy, Namakkal, India
| | - P Manivasakam
- Pharmacy Practice, JKKN College of Pharmacy, Namakkal, India
- Department of Pharmaceutics, Vellalar College of Pharmacy, Erode, India
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3
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Liang J, Luo S, Huang B. Case Report: SCN5A mutations in three young patients with sick sinus syndrome. Front Cardiovasc Med 2023; 10:1294197. [PMID: 38107266 PMCID: PMC10722160 DOI: 10.3389/fcvm.2023.1294197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 11/17/2023] [Indexed: 12/19/2023] Open
Abstract
Background Sick Sinus Syndrome (SSS) is generally regarded as a degenerative disease with aging; however, genetic mutations have been confirmed to be associated with SSS. Among them, mutations in SCN5A are common in patients with SSS. We report three young SSS patients with SCN5A mutations at different sites that have not been previously reported in Asian patients. Case presentation The three patients were all young females who presented with symptoms of severe bradycardia and paroxysmal atrial flutter, for which two patients received ablation therapy. However, after ablation, Holter monitoring indicated a significant long cardiac arrest; therefore, the patients received pacemaker implantation. The three patients had familial SSS, and genetic testing was performed. Mutations were found in SCN5A at different sites in the three families. All three patients received pacemaker implantation, resulting in the symptoms of severe bradycardia disappearing. Conclusion SCN5A heterozygous mutations are common among patients clinically affected by SSS. Their causative role is confirmed by our data and by the co-occurrence of genetic arrhythmias among our patients. Genetic testing for SSS cannot be performed as a single gene panel because of feasible literature results, but in presence of familial and personal history of SSS in association with arrhythmias can provide clinically useful information.
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Affiliation(s)
| | - Suxin Luo
- Department of Cardiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Bi Huang
- Department of Cardiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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4
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Marcoux E, Sosnowski D, Ninni S, Mackasey M, Cadrin-Tourigny J, Roberts JD, Olesen MS, Fatkin D, Nattel S. Genetic Atrial Cardiomyopathies: Common Features, Specific Differences, and Broader Relevance to Understanding Atrial Cardiomyopathy. Circ Arrhythm Electrophysiol 2023; 16:675-698. [PMID: 38018478 DOI: 10.1161/circep.123.003750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
Atrial cardiomyopathy is a condition that causes electrical and contractile dysfunction of the atria, often along with structural and functional changes. Atrial cardiomyopathy most commonly occurs in conjunction with ventricular dysfunction, in which case it is difficult to discern the atrial features that are secondary to ventricular dysfunction from those that arise as a result of primary atrial abnormalities. Isolated atrial cardiomyopathy (atrial-selective cardiomyopathy [ASCM], with minimal or no ventricular function disturbance) is relatively uncommon and has most frequently been reported in association with deleterious rare genetic variants. The genes involved can affect proteins responsible for various biological functions, not necessarily limited to the heart but also involving extracardiac tissues. Atrial enlargement and atrial fibrillation are common complications of ASCM and are often the predominant clinical features. Despite progress in identifying disease-causing rare variants, an overarching understanding and approach to the molecular pathogenesis, phenotypic spectrum, and treatment of genetic ASCM is still lacking. In this review, we aim to analyze the literature relevant to genetic ASCM to understand the key features of this rather rare condition, as well as to identify distinct characteristics of ASCM and its arrhythmic complications that are related to specific genotypes. We outline the insights that have been gained using basic research models of genetic ASCM in vitro and in vivo and correlate these with patient outcomes. Finally, we provide suggestions for the future investigation of patients with genetic ASCM and improvements to basic scientific models and systems. Overall, a better understanding of the genetic underpinnings of ASCM will not only provide a better understanding of this condition but also promises to clarify our appreciation of the more commonly occurring forms of atrial cardiomyopathy associated with ventricular dysfunction.
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Affiliation(s)
- Edouard Marcoux
- Research Center, Montreal Heart Institute, Université de Montréal. (E.M., D.S., S. Ninni, M.M., S. Nattel)
- Faculty of Pharmacy, Université de Montréal. (E.M.)
| | - Deanna Sosnowski
- Research Center, Montreal Heart Institute, Université de Montréal. (E.M., D.S., S. Ninni, M.M., S. Nattel)
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada (D.S., M.M., S. Nattel)
| | - Sandro Ninni
- Research Center, Montreal Heart Institute, Université de Montréal. (E.M., D.S., S. Ninni, M.M., S. Nattel)
- Université de Lille, Inserm, CHU Lille, Institut Pasteur de Lille, France (S. Ninni)
| | - Martin Mackasey
- Research Center, Montreal Heart Institute, Université de Montréal. (E.M., D.S., S. Ninni, M.M., S. Nattel)
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada (D.S., M.M., S. Nattel)
| | - Julia Cadrin-Tourigny
- Cardiovascular Genetics Center, Montreal Heart Institute, Faculty of Medicine, Université de Montréal. (J.C.-T.)
| | - Jason D Roberts
- Population Health Research Institute, McMaster University and Hamilton Health Sciences, Canada (J.D.R.)
| | - Morten Salling Olesen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark (M.S.O.)
| | - Diane Fatkin
- Victor Chang Cardiac Research Institute, Darlinghurst (D.F.)
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Kensington (D.F.)
- Department of Cardiology, St Vincent's Hospital, Darlinghurst, NSW, Australia (D.F.)
| | - Stanley Nattel
- Research Center, Montreal Heart Institute, Université de Montréal. (E.M., D.S., S. Ninni, M.M., S. Nattel)
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal. (S. Nattel.)
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada (D.S., M.M., S. Nattel)
- Institute of Pharmacology. West German Heart and Vascular Center, University Duisburg-Essen, Germany (S. Nattel)
- IHU LYRIC & Fondation Bordeaux Université de Bordeaux, France (S. Nattel)
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5
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Sharma AK, Singh S, Bhat M, Gill K, Zaid M, Kumar S, Shakya A, Tantray J, Jose D, Gupta R, Yangzom T, Sharma RK, Sahu SK, Rathore G, Chandolia P, Singh M, Mishra A, Raj S, Gupta A, Agarwal M, Kifayat S, Gupta A, Gupta P, Vashist A, Vaibhav P, Kathuria N, Yadav V, Singh RP, Garg A. New drug discovery of cardiac anti-arrhythmic drugs: insights in animal models. Sci Rep 2023; 13:16420. [PMID: 37775650 PMCID: PMC10541452 DOI: 10.1038/s41598-023-41942-4] [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: 04/24/2023] [Accepted: 09/04/2023] [Indexed: 10/01/2023] Open
Abstract
Cardiac rhythm regulated by micro-macroscopic structures of heart. Pacemaker abnormalities or disruptions in electrical conduction, lead to arrhythmic disorders may be benign, typical, threatening, ultimately fatal, occurs in clinical practice, patients on digitalis, anaesthesia or acute myocardial infarction. Both traditional and genetic animal models are: In-vitro: Isolated ventricular Myocytes, Guinea pig papillary muscles, Patch-Clamp Experiments, Porcine Atrial Myocytes, Guinea pig ventricular myocytes, Guinea pig papillary muscle: action potential and refractory period, Langendorff technique, Arrhythmia by acetylcholine or potassium. Acquired arrhythmia disorders: Transverse Aortic Constriction, Myocardial Ischemia, Complete Heart Block and AV Node Ablation, Chronic Tachypacing, Inflammation, Metabolic and Drug-Induced Arrhythmia. In-Vivo: Chemically induced arrhythmia: Aconitine antagonism, Digoxin-induced arrhythmia, Strophanthin/ouabain-induced arrhythmia, Adrenaline-induced arrhythmia, and Calcium-induced arrhythmia. Electrically induced arrhythmia: Ventricular fibrillation electrical threshold, Arrhythmia through programmed electrical stimulation, sudden coronary death in dogs, Exercise ventricular fibrillation. Genetic Arrhythmia: Channelopathies, Calcium Release Deficiency Syndrome, Long QT Syndrome, Short QT Syndrome, Brugada Syndrome. Genetic with Structural Heart Disease: Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia, Dilated Cardiomyopathy, Hypertrophic Cardiomyopathy, Atrial Fibrillation, Sick Sinus Syndrome, Atrioventricular Block, Preexcitation Syndrome. Arrhythmia in Pluripotent Stem Cell Cardiomyocytes. Conclusion: Both traditional and genetic, experimental models of cardiac arrhythmias' characteristics and significance help in development of new antiarrhythmic drugs.
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Affiliation(s)
- Ashish Kumar Sharma
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India.
| | - Shivam Singh
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Mehvish Bhat
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Kartik Gill
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Mohammad Zaid
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Sachin Kumar
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Anjali Shakya
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Junaid Tantray
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Divyamol Jose
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Rashmi Gupta
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Tsering Yangzom
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Rajesh Kumar Sharma
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | | | - Gulshan Rathore
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Priyanka Chandolia
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Mithilesh Singh
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Anurag Mishra
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Shobhit Raj
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Archita Gupta
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Mohit Agarwal
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Sumaiya Kifayat
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Anamika Gupta
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Prashant Gupta
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Ankit Vashist
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Parth Vaibhav
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Nancy Kathuria
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Vipin Yadav
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Ravindra Pal Singh
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Arun Garg
- MVN University, Palwal, Haryana, India
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6
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Blackwell DJ, Schmeckpeper J, Knollmann BC. Animal Models to Study Cardiac Arrhythmias. Circ Res 2022; 130:1926-1964. [PMID: 35679367 DOI: 10.1161/circresaha.122.320258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac arrhythmias are a significant cause of morbidity and mortality worldwide, accounting for 10% to 15% of all deaths. Although most arrhythmias are due to acquired heart disease, inherited channelopathies and cardiomyopathies disproportionately affect children and young adults. Arrhythmogenesis is complex, involving anatomic structure, ion channels and regulatory proteins, and the interplay between cells in the conduction system, cardiomyocytes, fibroblasts, and the immune system. Animal models of arrhythmia are powerful tools for studying not only molecular and cellular mechanism of arrhythmogenesis but also more complex mechanisms at the whole heart level, and for testing therapeutic interventions. This review summarizes basic and clinical arrhythmia mechanisms followed by an in-depth review of published animal models of genetic and acquired arrhythmia disorders.
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Affiliation(s)
- Daniel J Blackwell
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Jeffrey Schmeckpeper
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Bjorn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN
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7
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Yu G, Chakrabarti S, Tischenko M, Chen AL, Wang Z, Cho H, French BA, Naga Prasad SV, Chen Q, Wang QK. Gene therapy targeting protein trafficking regulator MOG1 in mouse models of Brugada syndrome, arrhythmias, and mild cardiomyopathy. Sci Transl Med 2022; 14:eabf3136. [PMID: 35675436 DOI: 10.1126/scitranslmed.abf3136] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Brugada syndrome (BrS) is a fatal arrhythmia that causes an estimated 4% of all sudden death in high-incidence areas. SCN5A encodes cardiac sodium channel NaV1.5 and causes 25 to 30% of BrS cases. Here, we report generation of a knock-in (KI) mouse model of BrS (Scn5aG1746R/+). Heterozygous KI mice recapitulated some of the clinical features of BrS, including an ST segment abnormality (a prominent J wave) on electrocardiograms and development of spontaneous ventricular tachyarrhythmias (VTs), seizures, and sudden death. VTs were caused by shortened cardiac action potential duration and late phase 3 early afterdepolarizations associated with reduced sodium current density (INa) and increased Kcnd3 and Cacna1c expression. We developed a gene therapy using adeno-associated virus serotype 9 (AAV9) vector-mediated MOG1 delivery for up-regulation of MOG1, a chaperone that binds to NaV1.5 and traffics it to the cell surface. MOG1 was chosen for gene therapy because the large size of the SCN5A coding sequence (6048 base pairs) exceeds the packaging capacity of AAV vectors. AAV9-MOG1 gene therapy increased cell surface expression of NaV1.5 and ventricular INa, reversed up-regulation of Kcnd3 and Cacna1c expression, normalized cardiac action potential abnormalities, abolished J waves, and blocked VT in Scn5aG1746R/+ mice. Gene therapy also rescued the phenotypes of cardiac arrhythmias and contractile dysfunction in heterozygous humanized KI mice with SCN5A mutation p.D1275N. Using a small chaperone protein may have broad implications for targeting disease-causing genes exceeding the size capacity of AAV vectors.
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Affiliation(s)
- Gang Yu
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, and Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
| | - Susmita Chakrabarti
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
| | - Miroslava Tischenko
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
| | - Ai-Lan Chen
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Department of Cardiology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 511436, P. R. China
| | - Zhijie Wang
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, and Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
| | - Hyosuk Cho
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Brent A French
- Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, VA 22903, USA
| | - Sathyamangla V Naga Prasad
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
| | - Qiuyun Chen
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
| | - Qing K Wang
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, and Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195, USA.,Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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8
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Daimi H, Lozano-Velasco E, Aranega A, Franco D. Genomic and Non-Genomic Regulatory Mechanisms of the Cardiac Sodium Channel in Cardiac Arrhythmias. Int J Mol Sci 2022; 23:1381. [PMID: 35163304 PMCID: PMC8835759 DOI: 10.3390/ijms23031381] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/30/2021] [Accepted: 01/06/2022] [Indexed: 12/19/2022] Open
Abstract
Nav1.5 is the predominant cardiac sodium channel subtype, encoded by the SCN5A gene, which is involved in the initiation and conduction of action potentials throughout the heart. Along its biosynthesis process, Nav1.5 undergoes strict genomic and non-genomic regulatory and quality control steps that allow only newly synthesized channels to reach their final membrane destination and carry out their electrophysiological role. These regulatory pathways are ensured by distinct interacting proteins that accompany the nascent Nav1.5 protein along with different subcellular organelles. Defects on a large number of these pathways have a tremendous impact on Nav1.5 functionality and are thus intimately linked to cardiac arrhythmias. In the present review, we provide current state-of-the-art information on the molecular events that regulate SCN5A/Nav1.5 and the cardiac channelopathies associated with defects in these pathways.
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Affiliation(s)
- Houria Daimi
- Biochemistry and Molecular Biology Laboratory, Faculty of Pharmacy, University of Monastir, Monastir 5000, Tunisia
| | - Estefanía Lozano-Velasco
- Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain; (E.L.-V.); (A.A.); (D.F.)
- Medina Foundation, Technology Park of Health Sciences, Av. del Conocimiento, 34, 18016 Granada, Spain
| | - Amelia Aranega
- Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain; (E.L.-V.); (A.A.); (D.F.)
- Medina Foundation, Technology Park of Health Sciences, Av. del Conocimiento, 34, 18016 Granada, Spain
| | - Diego Franco
- Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain; (E.L.-V.); (A.A.); (D.F.)
- Medina Foundation, Technology Park of Health Sciences, Av. del Conocimiento, 34, 18016 Granada, Spain
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9
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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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10
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Genetics and Epigenetics of Atrial Fibrillation. Int J Mol Sci 2020; 21:ijms21165717. [PMID: 32784971 PMCID: PMC7460853 DOI: 10.3390/ijms21165717] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 07/22/2020] [Accepted: 07/27/2020] [Indexed: 12/13/2022] Open
Abstract
Atrial fibrillation (AF) is known to be the most common supraventricular arrhythmia affecting up to 1% of the general population. Its prevalence exponentially increases with age and could reach up to 8% in the elderly population. The management of AF is a complex issue that is addressed by extensive ongoing basic and clinical research. AF centers around different types of disturbances, including ion channel dysfunction, Ca2+-handling abnormalities, and structural remodeling. Genome-wide association studies (GWAS) have uncovered over 100 genetic loci associated with AF. Most of these loci point to ion channels, distinct cardiac-enriched transcription factors, as well as to other regulatory genes. Recently, the discovery of post-transcriptional regulatory mechanisms, involving non-coding RNAs (especially microRNAs), DNA methylation, and histone modification, has allowed to decipher how a normal heart develops and which modifications are involved in reshaping the processes leading to arrhythmias. This review aims to provide a current state of the field regarding the identification and functional characterization of AF-related epigenetic regulatory networks
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11
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Huang X, Li Y, Zhang J, Wang X, Li Z, Li G. The molecular genetic basis of atrial fibrillation. Hum Genet 2020; 139:1485-1498. [PMID: 32617797 DOI: 10.1007/s00439-020-02203-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 06/26/2020] [Indexed: 12/15/2022]
Abstract
As the most common cardiac arrhythmia, atrial fibrillation (AF) is a major risk factor for stroke, heart failure, and premature death with considerable associated costs. However, no available treatment options have optimal benefit-harm profiles currently, reflecting an incomplete understanding of the biological mechanisms underlying this complex arrhythmia. Recently, molecular epidemiological studies, especially genome-wide association studies, have emphasized the substantial genetic component of AF etiology. A comprehensive mapping of the genetic underpinnings for AF can expand our knowledge of AF mechanism and further facilitate the process of locating novel therapeutics for AF. Here we provide a state-of-the-art review of the molecular genetics of AF incorporating evidence from linkage analysis and candidate gene, as well as genome-wide association studies of common variations and rare copy number variations; potential epigenetic modifications (e.g., DNA methylation, histone modification, and non-coding RNAs) are also involved. We also outline the challenges in mechanism investigation and potential future directions in this article.
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Affiliation(s)
- Xin Huang
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, 466 Newport Middle Road, Haizhu District, Guangzhou, 510317, Guangdong, China
| | - Yuhui Li
- Department of Cardiology, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Junguo Zhang
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, 466 Newport Middle Road, Haizhu District, Guangzhou, 510317, Guangdong, China
| | - Xiaojie Wang
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, 466 Newport Middle Road, Haizhu District, Guangzhou, 510317, Guangdong, China
| | - Ziyi Li
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, 466 Newport Middle Road, Haizhu District, Guangzhou, 510317, Guangdong, China
| | - Guowei Li
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, 466 Newport Middle Road, Haizhu District, Guangzhou, 510317, Guangdong, China. .,Department of Health Research Methods, Evidence, and Impact (HEI), McMaster University Hamilton, 1280 Main St West, Hamilton, ON, L8S 4L8, Canada.
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12
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Reevaluating the Mutation Classification in Genetic Studies of Bradycardia Using ACMG/AMP Variant Classification Framework. Int J Genomics 2020; 2020:2415850. [PMID: 32211440 PMCID: PMC7061116 DOI: 10.1155/2020/2415850] [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: 10/07/2019] [Accepted: 02/08/2020] [Indexed: 11/17/2022] Open
Abstract
PURPOSE Next-generation sequencing (NGS) has become more accessible, leading to an increasing number of genetic studies of familial bradycardia being reported. However, most of the variants lack full evaluation. The relationship between genetic factors and bradycardia should be summarized and reevaluated. METHODS We summarized genetic studies published in the PubMed database from 2008/1/1 to 2019/9/1 and used the ACMG/AMP classification framework to analyze related sequence variants. RESULTS We identified 88 articles, 99 sequence variants, and 34 genes after searching the PubMed database and classified ABCC9, ACTN2, CACNA1C, DES, HCN4, KCNQ1, KCNH2, LMNA, MECP2, LAMP2, NPPA, SCN5A, and TRPM4 as high-priority genes causing familial bradycardia. Most mutated genes have been reported as having multiple clinical manifestations. CONCLUSIONS For patients with familial CCD, 13 high-priority genes are recommended for evaluation. For genetic studies, variants should be carefully evaluated using the ACMG/AMP variant classification framework before publication.
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13
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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: 12] [Impact Index Per Article: 2.4] [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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14
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Asatryan B, Medeiros-Domingo A. Molecular and genetic insights into progressive cardiac conduction disease. Europace 2019; 21:1145-1158. [DOI: 10.1093/europace/euz109] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/27/2019] [Indexed: 12/14/2022] Open
Abstract
Abstract
Progressive cardiac conduction disease (PCCD) is often a primarily genetic disorder, with clinical and genetic overlaps with other inherited cardiac and metabolic diseases. A number of genes have been implicated in PCCD pathogenesis with or without structural heart disease or systemic manifestations. Precise genetic diagnosis contributes to risk stratification, better selection of specific therapy and allows familiar cascade screening. Cardiologists should be aware of the different phenotypes emerging from different gene-mutations and the potential risk of sudden cardiac death. Genetic forms of PCCD often overlap or coexist with other inherited heart diseases or manifest in the context of multisystem syndromes. Despite the significant advances in the knowledge of the genetic architecture of PCCD and overlapping diseases, in a measurable fraction of PCCD cases, including in familial clustering of disease, investigations of known cardiac disease-associated genes fail to reveal the underlying substrate, suggesting that new causal genes are yet to be discovered. Here, we provide insight into genetics and molecular mechanisms of PCCD and related diseases. We also highlight the phenotypic overlaps of PCCD with other inherited cardiac and metabolic diseases, present unmet challenges in clinical practice, and summarize the available therapeutic options for affected patients.
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Affiliation(s)
- Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, Freiburgstrasse 8, Bern, Switzerland
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15
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Lozano-Velasco E, Garcia-Padilla C, Aránega AE, Franco D. Genetics of Atrial Fibrilation: In Search of Novel Therapeutic Targets. Cardiovasc Hematol Disord Drug Targets 2019; 19:183-194. [PMID: 30727926 DOI: 10.2174/1871529x19666190206150349] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 01/16/2019] [Accepted: 01/23/2019] [Indexed: 06/09/2023]
Abstract
Atrial fibrillation (AF) is the most frequent arrhythmogenic disease in humans, ranging from 2% in the general population and rising up to 10-12% in 80+ years. Genetic analyses of AF familiar cases have identified a series of point mutations in distinct ion channels, supporting a causative link. However, these genetic defects only explain a minority of AF patients. Genomewide association studies identified single nucleotide polymorphisms (SNPs), close to PITX2 on 4q25 chromosome, that are highly associated to AF. Subsequent GWAS studies have identified several new loci, involving additional transcription and growth factors. Furthermore, these risk 4q25 SNPs serve as surrogate biomarkers to identify AF recurrence in distinct surgical and pharmacological interventions. Experimental studies have demonstrated an intricate signalling pathway supporting a key role of the homeobox transcription factor PITX2 as a transcriptional regulator. Furthermore, cardiovascular risk factors such as hyperthyroidism, hypertension and redox homeostasis have been identified to modulate PITX2 driven gene regulatory networks. We provide herein a state-of-the-art review of the genetic bases of atrial fibrillation, our current understanding of the genetic regulatory networks involved in AF and its plausible usage for searching novel therapeutic targets.
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Affiliation(s)
- Estefanía Lozano-Velasco
- Cardiovascular Development Group, Department of Experimental Biology, University of Jaen, Jaen, Spain
| | - Carlos Garcia-Padilla
- Cardiovascular Development Group, Department of Experimental Biology, University of Jaen, Jaen, Spain
| | - Amelia E Aránega
- Cardiovascular Development Group, Department of Experimental Biology, University of Jaen, Jaen, Spain
| | - Diego Franco
- Cardiovascular Development Group, Department of Experimental Biology, University of Jaen, Jaen, Spain
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16
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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: 16] [Impact Index Per Article: 2.7] [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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17
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Elston S, Kaski J, Starling L. Long QT syndrome with a functional 2:1 block and multilevel conduction disease. PROGRESS IN PEDIATRIC CARDIOLOGY 2018. [DOI: 10.1016/j.ppedcard.2018.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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18
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Translating emerging molecular genetic insights into clinical practice in inherited cardiomyopathies. J Mol Med (Berl) 2018; 96:993-1024. [PMID: 30128729 DOI: 10.1007/s00109-018-1685-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 07/22/2018] [Accepted: 08/08/2018] [Indexed: 12/19/2022]
Abstract
Cardiomyopathies are primarily genetic disorders of the myocardium associated with higher risk of life-threatening cardiac arrhythmias, heart failure, and sudden cardiac death. The evolving knowledge in genomic medicine during the last decade has reshaped our understanding of cardiomyopathies as diseases of multifactorial nature and complex pathophysiology. Genetic testing in cardiomyopathies has subsequently grown from primarily a research tool into an essential clinical evaluation piece with important clinical implications for patients and their families. The purpose of this review is to provide with a contemporary insight into the implications of genetic testing in diagnosis, therapy, and prognosis of patients with inherited cardiomyopathies. Here, we summarize the contemporary knowledge on genotype-phenotype correlations in inherited cardiomyopathies and highlight the recent significant achievements in the field of translational cardiovascular genetics.
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19
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Zhang X, Yoon JY, Morley M, McLendon JM, Mapuskar KA, Gutmann R, Mehdi H, Bloom HL, Dudley SC, Ellinor PT, Shalaby AA, Weiss R, Tang WHW, Moravec CS, Singh M, Taylor AL, Yancy CW, Feldman AM, McNamara DM, Irani K, Spitz DR, Breheny P, Margulies KB, London B, Boudreau RL. A common variant alters SCN5A-miR-24 interaction and associates with heart failure mortality. J Clin Invest 2018; 128:1154-1163. [PMID: 29457789 DOI: 10.1172/jci95710] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 12/12/2017] [Indexed: 12/19/2022] Open
Abstract
SCN5A encodes the voltage-gated Na+ channel NaV1.5 that is responsible for depolarization of the cardiac action potential and rapid intercellular conduction. Mutations disrupting the SCN5A coding sequence cause inherited arrhythmias and cardiomyopathy, and single-nucleotide polymorphisms (SNPs) linked to SCN5A splicing, localization, and function associate with heart failure-related sudden cardiac death. However, the clinical relevance of SNPs that modulate SCN5A expression levels remains understudied. We recently generated a transcriptome-wide map of microRNA (miR) binding sites in human heart, evaluated their overlap with common SNPs, and identified a synonymous SNP (rs1805126) adjacent to a miR-24 site within the SCN5A coding sequence. This SNP was previously shown to reproducibly associate with cardiac electrophysiological parameters, but was not considered to be causal. Here, we show that miR-24 potently suppresses SCN5A expression and that rs1805126 modulates this regulation. We found that the rs1805126 minor allele associates with decreased cardiac SCN5A expression and that heart failure subjects homozygous for the minor allele have decreased ejection fraction and increased mortality, but not increased ventricular tachyarrhythmias. In mice, we identified a potential basis for this in discovering that decreased Scn5a expression leads to accumulation of myocardial reactive oxygen species. Together, these data reiterate the importance of considering the mechanistic significance of synonymous SNPs as they relate to miRs and disease, and highlight a surprising link between SCN5A expression and nonarrhythmic death in heart failure.
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Affiliation(s)
- Xiaoming Zhang
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Jin-Young Yoon
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Michael Morley
- Department of Internal Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jared M McLendon
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Kranti A Mapuskar
- Department of Radiation Oncology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Rebecca Gutmann
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Haider Mehdi
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Heather L Bloom
- Department of Medicine, Emory University Medical Center, Atlanta, Georgia, USA
| | - Samuel C Dudley
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Patrick T Ellinor
- Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Alaa A Shalaby
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Raul Weiss
- Department of Internal Medicine, The Ohio State University Medical Center, Columbus, Ohio, USA
| | - W H Wilson Tang
- Department of Cardiovascular Medicine, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, USA
| | - Christine S Moravec
- Department of Molecular Cardiology, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, USA
| | - Madhurmeet Singh
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Anne L Taylor
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Clyde W Yancy
- Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Arthur M Feldman
- Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Dennis M McNamara
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Kaikobad Irani
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Douglas R Spitz
- Department of Radiation Oncology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Patrick Breheny
- Department of Biostatistics, University of Iowa College of Public Heath, Iowa City, Iowa, USA
| | - Kenneth B Margulies
- Department of Internal Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Barry London
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Ryan L Boudreau
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
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Savio-Galimberti E, Argenziano M, Antzelevitch C. Cardiac Arrhythmias Related to Sodium Channel Dysfunction. Handb Exp Pharmacol 2018; 246:331-354. [PMID: 28965168 DOI: 10.1007/164_2017_43] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The voltage-gated cardiac sodium channel (Nav1.5) is a mega-complex comprised of a pore-forming α subunit and 4 ancillary β-subunits together with numerous protein partners. Genetic defects in the form of rare variants in one or more sodium channel-related genes can cause a loss- or gain-of-function of sodium channel current (INa) leading to the manifestation of various disease phenotypes, including Brugada syndrome, long QT syndrome, progressive cardiac conduction disease, sick sinus syndrome, multifocal ectopic Purkinje-related premature contractions, and atrial fibrillation. Some sodium channelopathies have also been shown to be responsible for sudden infant death syndrome (SIDS). Although these genetic defects often present as pure electrical diseases, recent studies point to a contribution of structural abnormalities to the electrocardiographic and arrhythmic manifestation in some cases, such as dilated cardiomyopathy. The same rare variants in SCN5A or related genes may present with different clinical phenotypes in different individuals and sometimes in members of the same family. Genetic background and epigenetic and environmental factors contribute to the expression of these overlap syndromes. Our goal in this chapter is to review and discuss what is known about the clinical phenotype and genotype of each cardiac sodium channelopathy, and to briefly discuss the underlying mechanisms.
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Affiliation(s)
| | - Mariana Argenziano
- Lankenau Institute for Medical Research, 100 E. Lancaster Avenue, Wynnewood, PA, 19096, USA
| | - Charles Antzelevitch
- Lankenau Institute for Medical Research, 100 E. Lancaster Avenue, Wynnewood, PA, 19096, USA.
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21
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Vanninen SUM, Nikus K, Aalto-Setälä K. Electrocardiogram changes and atrial arrhythmias in individuals carrying sodium channel SCN5A D1275N mutation. Ann Med 2017; 49:496-503. [PMID: 28294644 DOI: 10.1080/07853890.2017.1307515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
INTRODUCTION The cardiac sodium channel SCN5A regulates atrioventricular and ventricular depolarization as well as cardiac conduction. Patients with cardiac electrical abnormalities have an increased risk of sudden cardiac death (SCD) and cardio-embolic stroke. Optimal management of cardiac disease includes the understanding of association between the causative mutations and the clinical phenotype. A 12-lead electrocardiogram (ECG) is an easy and inexpensive tool for finding risk patients. MATERIALS AND METHODS A blood sample for DNA extraction was obtained in a Finnish family with 43 members; systematic 12-lead ECG analysis was performed in 13 of the family members carrying an SCN5A D1275N mutation. Conduction defects and supraventricular arrhythmias, including atrial fibrillation/flutter, atrioventricular nodal re-entry tachycardia (AVNRT) and junctional rhythm were searched for. RESULTS Five (38%) mutation carriers had fascicular or bundle branch block, 10 had atrial arrhythmias; no ventricular arrhythmias were found. Notching of the R- and S waves - including initial QRS fragmentation - and prolonged S-wave upstroke were present in all the affected family members. Notably, four (31%) affected family members had a stroke before the age of 31 and two experienced premature death. CONCLUSIONS A 12-lead ECG can be used to predict arrhythmias in SCN5A D1275N mutation carriers. Key messages The 12-lead ECG may reveal cardiac abnormalities even before clinical symptoms occur. Specific ECG findings - initial QRS fragmentation, prolonged S-wave upstroke as well as supraventricular arrhythmias - were frequently encountered in all SCN5A D1257N mutation carriers. ECG follow-up is recommended for all SCN5A D1275N mutation carriers.
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Affiliation(s)
| | - Kjell Nikus
- a Heart Center, Tampere University Hospital , Tampere , Finland.,b Faculty of Medicine and Life Sciences , University of Tampere , Tampere , Finland
| | - Katriina Aalto-Setälä
- a Heart Center, Tampere University Hospital , Tampere , Finland.,b Faculty of Medicine and Life Sciences , University of Tampere , Tampere , Finland.,c BioMediTech, University of Tampere , Tampere , Finland
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22
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Abstract
Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias.
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Affiliation(s)
- Christopher L-H Huang
- Physiological Laboratory and the Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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The Role of Pharmacogenetics in Atrial Fibrillation Therapeutics: Is Personalized Therapy in Sight? J Cardiovasc Pharmacol 2016; 67:9-18. [PMID: 25970841 DOI: 10.1097/fjc.0000000000000280] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia worldwide requiring therapy. Despite recent advances in catheter-based and surgical therapy, antiarrhythmic drugs (AADs) remain the mainstay of treatment for symptomatic AF. However, response in individual patients is highly variable with over half the patients treated with rhythm control therapy experiencing recurrence of AF within a year. Contemporary AADs used to suppress AF are incompletely and unpredictably effective and associated with significant risks of proarrhythmia and noncardiac toxicities. Furthermore, this "one-size" fits all strategy for selecting antiarrhythmics is based largely on minimizing risk of adverse effects rather than on the likelihood of suppressing AF. The limited success of rhythm control therapy is in part due to heterogeneity of the underlying substrate, interindividual differences in disease mechanisms, and our inability to predict response to AADs in individual patients. Genetic studies of AF over the past decade have revealed that susceptibility to and response to therapy for AF is modulated by the underlying genetic substrate. However, the bedside application of these new discoveries to the management of AF patients has thus far been disappointing. This may in part be related to our limited understanding about genetic predictors of drug response in general, the challenges associated with determining efficacy of response to AADs, and lack of randomized genotype-directed clinical trials. Nonetheless, recent studies have shown that common AF susceptibility risk alleles at the chromosome 4q25 locus modulated response to AADs, electrical cardioversion, and ablation therapy. This monograph discusses how genetic approaches to AF have not only provided important insights into underlying mechanisms but also identified AF subtypes that can be better targeted with more mechanism-based "personalized" therapy.
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Veerman CC, Wilde AAM, Lodder EM. The cardiac sodium channel gene SCN5A and its gene product NaV1.5: Role in physiology and pathophysiology. Gene 2015; 573:177-87. [PMID: 26361848 DOI: 10.1016/j.gene.2015.08.062] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 07/31/2015] [Accepted: 08/27/2015] [Indexed: 12/18/2022]
Abstract
The gene SCN5A encodes the main cardiac sodium channel NaV1.5. This channel predominates the cardiac sodium current, INa, which underlies the fast upstroke of the cardiac action potential. As such, it plays a crucial role in cardiac electrophysiology. Over the last 60years a tremendous amount of knowledge regarding its function at the electrophysiological and molecular level has been acquired. Furthermore, genetic studies have shown that mutations in SCN5A are associated with multiple cardiac diseases (e.g. Brugada syndrome, Long QT syndrome, conduction disease and cardiomyopathy), while genetic variation in the general population has been associated with differences in cardiac conduction and risk of arrhythmia through genome wide association studies. In this review we aim to give an overview of the current knowledge (and the gaps therein) on SCN5A and NaV1.5.
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Affiliation(s)
- Christiaan C Veerman
- Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
| | - Elisabeth M Lodder
- Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
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Chiang DY, Kim JJ, Valdes SO, de la Uz C, Fan Y, Orcutt J, Domino M, Smith M, Wehrens XHT, Miyake CY. Loss-of-Function SCN5A Mutations Associated With Sinus Node Dysfunction, Atrial Arrhythmias, and Poor Pacemaker Capture. Circ Arrhythm Electrophysiol 2015; 8:1105-12. [PMID: 26111534 DOI: 10.1161/circep.115.003098] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 06/22/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND Cardiac device implantation can be complicated by inability to adequately place leads because of significant lead capture issues. This study sought to determine whether there are genetic bases that underlie poor lead capture. METHODS AND RESULTS Retrospective review of all patients with structurally normal hearts who underwent new device implantation at Texas Children's Hospital between 2009 and 2014 was performed. Patients with inability to capture at 10 V or a final capture threshold ≥3 V at 0.4 ms during implant were analyzed. Among a total of 136 patients (median age, 13 years; range, 3 days to 46 years), 11 patients (8.1%) who underwent dual chamber device implantation had elevated thresholds in the atria (4), ventricle (3), or both chambers (4; atrial-lead threshold, 4.7±4.3 versus 0.7±0.3 V; ventricular-lead, 3.0±3.3 versus 0.7±0.3 V). All 11 patients presented with sinus node dysfunction and 10 had atrial arrhythmias. At implant, inability to find atrial capture was seen in 4 patients. Three demonstrated intermittent complete loss of ventricular capture after implantation: 1 has recurrent syncope, 2 eventually died. Genetic testing performed in 10 demonstrated 7 patients with 6 distinct SCN5A mutations, all predicted to be severe loss-of-function mutations by bioinformatic analyses. In the remaining patients, although putative pathogenic mutations were not found, multiple SCN5A polymorphisms were identified in 2 and a desmin mutation in 1. CONCLUSIONS This study suggests that significant capture issues at implant may be because of loss-of-function SCN5A mutations, providing new insights into SCN5A function. Recognition of this association may be critical for planning device implantation strategies and patient follow-up.
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Affiliation(s)
- David Y Chiang
- From the Cardiovascular Research Institute (D.Y.C., X.H.T.W., C.Y.M.), Medical Scientist Training Program (D.Y.C.), John Welsh Cardiovascular Diagnostic Laboratory (Y.F.), and Department of Molecular Physiology and Biophysics (X.H.T.W., C.Y.M.), Baylor College of Medicine, Houston, TX; and Section of Pediatric Cardiology, Texas Children's Hospital, Houston (J.J.K., S.O.V., C.d.l.U., J.O., M.D., M.S., C.Y.M.)
| | - Jeffrey J Kim
- From the Cardiovascular Research Institute (D.Y.C., X.H.T.W., C.Y.M.), Medical Scientist Training Program (D.Y.C.), John Welsh Cardiovascular Diagnostic Laboratory (Y.F.), and Department of Molecular Physiology and Biophysics (X.H.T.W., C.Y.M.), Baylor College of Medicine, Houston, TX; and Section of Pediatric Cardiology, Texas Children's Hospital, Houston (J.J.K., S.O.V., C.d.l.U., J.O., M.D., M.S., C.Y.M.)
| | - Santiago O Valdes
- From the Cardiovascular Research Institute (D.Y.C., X.H.T.W., C.Y.M.), Medical Scientist Training Program (D.Y.C.), John Welsh Cardiovascular Diagnostic Laboratory (Y.F.), and Department of Molecular Physiology and Biophysics (X.H.T.W., C.Y.M.), Baylor College of Medicine, Houston, TX; and Section of Pediatric Cardiology, Texas Children's Hospital, Houston (J.J.K., S.O.V., C.d.l.U., J.O., M.D., M.S., C.Y.M.)
| | - Caridad de la Uz
- From the Cardiovascular Research Institute (D.Y.C., X.H.T.W., C.Y.M.), Medical Scientist Training Program (D.Y.C.), John Welsh Cardiovascular Diagnostic Laboratory (Y.F.), and Department of Molecular Physiology and Biophysics (X.H.T.W., C.Y.M.), Baylor College of Medicine, Houston, TX; and Section of Pediatric Cardiology, Texas Children's Hospital, Houston (J.J.K., S.O.V., C.d.l.U., J.O., M.D., M.S., C.Y.M.)
| | - Yuxin Fan
- From the Cardiovascular Research Institute (D.Y.C., X.H.T.W., C.Y.M.), Medical Scientist Training Program (D.Y.C.), John Welsh Cardiovascular Diagnostic Laboratory (Y.F.), and Department of Molecular Physiology and Biophysics (X.H.T.W., C.Y.M.), Baylor College of Medicine, Houston, TX; and Section of Pediatric Cardiology, Texas Children's Hospital, Houston (J.J.K., S.O.V., C.d.l.U., J.O., M.D., M.S., C.Y.M.)
| | - Jeffrey Orcutt
- From the Cardiovascular Research Institute (D.Y.C., X.H.T.W., C.Y.M.), Medical Scientist Training Program (D.Y.C.), John Welsh Cardiovascular Diagnostic Laboratory (Y.F.), and Department of Molecular Physiology and Biophysics (X.H.T.W., C.Y.M.), Baylor College of Medicine, Houston, TX; and Section of Pediatric Cardiology, Texas Children's Hospital, Houston (J.J.K., S.O.V., C.d.l.U., J.O., M.D., M.S., C.Y.M.)
| | - Melissa Domino
- From the Cardiovascular Research Institute (D.Y.C., X.H.T.W., C.Y.M.), Medical Scientist Training Program (D.Y.C.), John Welsh Cardiovascular Diagnostic Laboratory (Y.F.), and Department of Molecular Physiology and Biophysics (X.H.T.W., C.Y.M.), Baylor College of Medicine, Houston, TX; and Section of Pediatric Cardiology, Texas Children's Hospital, Houston (J.J.K., S.O.V., C.d.l.U., J.O., M.D., M.S., C.Y.M.)
| | - Melissa Smith
- From the Cardiovascular Research Institute (D.Y.C., X.H.T.W., C.Y.M.), Medical Scientist Training Program (D.Y.C.), John Welsh Cardiovascular Diagnostic Laboratory (Y.F.), and Department of Molecular Physiology and Biophysics (X.H.T.W., C.Y.M.), Baylor College of Medicine, Houston, TX; and Section of Pediatric Cardiology, Texas Children's Hospital, Houston (J.J.K., S.O.V., C.d.l.U., J.O., M.D., M.S., C.Y.M.)
| | - Xander H T Wehrens
- From the Cardiovascular Research Institute (D.Y.C., X.H.T.W., C.Y.M.), Medical Scientist Training Program (D.Y.C.), John Welsh Cardiovascular Diagnostic Laboratory (Y.F.), and Department of Molecular Physiology and Biophysics (X.H.T.W., C.Y.M.), Baylor College of Medicine, Houston, TX; and Section of Pediatric Cardiology, Texas Children's Hospital, Houston (J.J.K., S.O.V., C.d.l.U., J.O., M.D., M.S., C.Y.M.)
| | - Christina Y Miyake
- From the Cardiovascular Research Institute (D.Y.C., X.H.T.W., C.Y.M.), Medical Scientist Training Program (D.Y.C.), John Welsh Cardiovascular Diagnostic Laboratory (Y.F.), and Department of Molecular Physiology and Biophysics (X.H.T.W., C.Y.M.), Baylor College of Medicine, Houston, TX; and Section of Pediatric Cardiology, Texas Children's Hospital, Houston (J.J.K., S.O.V., C.d.l.U., J.O., M.D., M.S., C.Y.M.).
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Christophersen IE, Ellinor PT. Genetics of atrial fibrillation: from families to genomes. J Hum Genet 2015; 61:61-70. [DOI: 10.1038/jhg.2015.44] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 03/27/2015] [Accepted: 04/07/2015] [Indexed: 12/19/2022]
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Nikulina SY, Chernova AA, Shulman VA, Maksimov VN, Gavrilyuk OA, Tretyakova SS, Marilovceva OV. An investigation of the association of the H558R polymorphism of the SCN5A gene with idiopathic cardiac conduction disorders. Genet Test Mol Biomarkers 2015; 19:288-94. [PMID: 25871451 DOI: 10.1089/gtmb.2015.0012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIM The aim of this study was to investigate the predictive value of the rs1805124 polymorphism of the SCN5A gene with regard to idiopathic cardiac conduction disorders. RESULTS The AG genotype frequency was significantly higher in patients with an atrioventricular block (61,2%±6,0%) compared with healthy control subjects (34,8%±2,3%), p<0.0001. The AG genotype frequencies among patients with only idiopathic complete right bundle-branch block (CRBBB) (54,2%±5,5%) and those with both CLBBB and LAH (50%±5,1) were significantly higher than in the control group (34,8%±2,3%), p<0.005. CONCLUSIONS The AG genotype of the H558R (rs1805124) polymorphism of the SCN5A gene is a genetic predictor of idiopathic disorders of atrioventricular and intraventricular conduction.
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Affiliation(s)
- Svetlana Y Nikulina
- 1 Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky of the Ministry of Healthcare of the Russian Federation , Krasnoyarsk, Russian Federation
| | - Anna A Chernova
- 1 Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky of the Ministry of Healthcare of the Russian Federation , Krasnoyarsk, Russian Federation
| | - Vladimir A Shulman
- 1 Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky of the Ministry of Healthcare of the Russian Federation , Krasnoyarsk, Russian Federation
| | - Vladimir N Maksimov
- 2 Therapy and Preventive Medicine Research Institute of the Siberian Branch of the Russian Academy of Medical Sciences , Novosibirsk, Russian Federation
| | - Oksana A Gavrilyuk
- 1 Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky of the Ministry of Healthcare of the Russian Federation , Krasnoyarsk, Russian Federation
| | - Svetlana S Tretyakova
- 1 Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky of the Ministry of Healthcare of the Russian Federation , Krasnoyarsk, Russian Federation
| | - Olga V Marilovceva
- 3 Krasnoyarsk Interdistrict Clinical Hospital No. 20 named after I.S. Berzon , Krasnoyarsk, Russian Federation
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Zhao Z, Li W, Wang X, Chen Y, Li J, Yang W, Cheng L, Liu E, Liu T, Li G. Cilostazol ameliorates atrial ionic remodeling in long-term rapid atrial pacing dogs. Anatol J Cardiol 2014; 15:963-9. [PMID: 25880049 PMCID: PMC5368467 DOI: 10.5152/akd.2014.5962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Objective: Ionic remodeling has a close correlation with the occurrence of atrial fibrillation (AF). Atrial tachypacing remodeling is associated with characteristic ionic remodeling. The purpose of this study was to assess the efficacy of cilostazol, an oral phosphodiesterase 3 inhibitor, for preventing atrial ionic remodeling in long-term rapid atrial pacing (RAP) dogs. Methods: We use the methods of patch-clamp and molecular biology to investigate the effect of cilostazol on ion channel and channel gene expression in long-term RAP dogs. Twenty-one dogs were randomly assigned to sham, control paced, and paced+cilostazol (5 mg/kg/d, cilo) groups, with 7 dogs in each group. The sham group was instrumented with a pacemaker but without pacing. RAP at 500 beats/min was maintained for 2 weeks in the paced and cilo groups. During the pacing, cilostazol was given orally in the cilo group. Whole-cell patch-clamp technique was used to record atrial L-type Ca2+ (ICaL) and fast sodium channel (INa) ionic currents. Western blot and RT-PCR were applied to estimate the gene expression of the ICaLa) 1C (Cav1.2) and INav1.5a) Nav1.5a) subunits. Statistical analysis was performed using SPSS 13.0. Results: The density of ICaL and INa currents (pA/pF) was significantly reduced in the paced group (ICaL: -6.55±1.42 vs. -4.46±0.59 pA/pF; INa: -48.24±10.54 vs. -30.48±5.20 pA/pF, p<0.01). The paced+cilo group could not increase the density of ICaL currents (ICaL: -4.37±1.25 pA/pF, p>0.05], while the INa currents were recovered (-44.54±12.65 pA/pF, p<0.01) compared with the paced group. The mRNA and protein expression levels of Cav1.2 and Nav1.5a were apparently down-regulated in the paced group (p<0.01), but after cilostazol treatment, both of these subunits were up-regulated significantly (p<0.01). Conclusion: Cilostazol may have protective effects on RAP-induced atrial ionic remodeling.
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Affiliation(s)
- Zhiqiang Zhao
- Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University; Tianjin-Republic of China.
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Zhang H, Ji H, Liu Z, Ji Y, You X, Ding G, Cheng Z. Voltage-dependent blockade by bupivacaine of cardiac sodium channels expressed in Xenopus oocytes. Neurosci Bull 2014; 30:697-710. [PMID: 25008571 DOI: 10.1007/s12264-013-1449-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 03/24/2014] [Indexed: 11/29/2022] Open
Abstract
Bupivacaine ranks as the most potent and efficient drug among class I local anesthetics, but its high potential for toxic reactions severely limits its clinical use. Although bupivacaine-induced toxicity is mainly caused by substantial blockade of voltage-gated sodium channels (VGSCs), how these hydrophobic molecules interact with the receptor sites to which they bind remains unclear. Nav1.5 is the dominant isoform of VGSCs expressed in cardiac myocytes, and its dysfunction may be the cause of bupivacaine-triggered arrhythmia. Here, we investigated the effect of bupivacaine on Nav1.5 within the clinical concentration range. The electrophysiological measurements on Nav1.5 expressed in Xenopus oocytes showed that bupivacaine induced a voltage- and concentration-dependent blockade on the peak of I Na and the half-maximal inhibitory dose was 4.51 μmol/L. Consistent with other local anesthetics, bupivacaine also induced a use-dependent blockade on Nav1.5 currents. The underlying mechanisms of this blockade may contribute to the fact that bupivacaine not only dose-dependently affected the gating kinetics of Nav1.5 but also accelerated the development of its open-state slow inactivation. These results extend our knowledge of the action of bupivacaine on cardiac sodium channels, and therefore contribute to the safer and more efficient clinical use of bupivacaine.
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Affiliation(s)
- Heng Zhang
- Lab of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai, 200444, China
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Abstract
Atrial fibrillation (AF) is the most common arrhythmia and is associated with increased morbidity. As the population ages and the prevalence of AF continues to rise, the socioeconomic consequences of AF will become increasingly burdensome. Although there are well-defined clinical risk factors for AF, a significant heritable component is also recognized. To identify the molecular basis for the heritability of AF, investigators have used a combination of classical Mendelian genetics, candidate gene screening, and genome-wide association studies. However, these avenues have, as yet, failed to define the majority of the heritability of AF. The goal of this review is to describe the results from both candidate gene and genome-wide studies, as well as to outline potential future avenues for creating a more complete understanding of AF genetics. Ultimately, a more comprehensive view of the genetic underpinnings for AF will lead to the identification of novel molecular pathways and improved risk prediction of this complex arrhythmia.
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Affiliation(s)
- Nathan R Tucker
- From the Cardiovascular Research Center, Massachusetts General Hospital, Boston
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Andrade J, Khairy P, Dobrev D, Nattel S. The clinical profile and pathophysiology of atrial fibrillation: relationships among clinical features, epidemiology, and mechanisms. Circ Res 2014; 114:1453-68. [PMID: 24763464 DOI: 10.1161/circresaha.114.303211] [Citation(s) in RCA: 810] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Atrial fibrillation (AF) is the most common arrhythmia (estimated lifetime risk, 22%-26%). The aim of this article is to review the clinical epidemiological features of AF and to relate them to underlying mechanisms. Long-established risk factors for AF include aging, male sex, hypertension, valve disease, left ventricular dysfunction, obesity, and alcohol consumption. Emerging risk factors include prehypertension, increased pulse pressure, obstructive sleep apnea, high-level physical training, diastolic dysfunction, predisposing gene variants, hypertrophic cardiomyopathy, and congenital heart disease. Potential risk factors are coronary artery disease, kidney disease, systemic inflammation, pericardial fat, and tobacco use. AF has substantial population health consequences, including impaired quality of life, increased hospitalization rates, stroke occurrence, and increased medical costs. The pathophysiology of AF centers around 4 general types of disturbances that promote ectopic firing and reentrant mechanisms, and include the following: (1) ion channel dysfunction, (2) Ca(2+)-handling abnormalities, (3) structural remodeling, and (4) autonomic neural dysregulation. Aging, hypertension, valve disease, heart failure, myocardial infarction, obesity, smoking, diabetes mellitus, thyroid dysfunction, and endurance exercise training all cause structural remodeling. Heart failure and prior atrial infarction also cause Ca(2+)-handling abnormalities that lead to focal ectopic firing via delayed afterdepolarizations/triggered activity. Neural dysregulation is central to atrial arrhythmogenesis associated with endurance exercise training and occlusive coronary artery disease. Monogenic causes of AF typically promote the arrhythmia via ion channel dysfunction, but the mechanisms of the more common polygenic risk factors are still poorly understood and under intense investigation. Better recognition of the clinical epidemiology of AF, as well as an improved appreciation of the underlying mechanisms, is needed to develop improved methods for AF prevention and management.
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Affiliation(s)
- Jason Andrade
- From Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada (J.A., P.K., S.N.); Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada (J.A.); and Faculty of Medicine, Institute of Pharmacology, University Duisburg-Essen, Essen, Germany (D.D.)
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Moreau A, Gosselin-Badaroudine P, Chahine M. Biophysics, pathophysiology, and pharmacology of ion channel gating pores. Front Pharmacol 2014; 5:53. [PMID: 24772081 PMCID: PMC3982104 DOI: 10.3389/fphar.2014.00053] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 03/12/2014] [Indexed: 12/19/2022] Open
Abstract
Voltage sensor domains (VSDs) are a feature of voltage gated ion channels (VGICs) and voltage sensitive proteins. They are composed of four transmembrane (TM) segments (S1–S4). Currents leaking through VSDs are called omega or gating pore currents. Gating pores are caused by mutations of the highly conserved positively charged amino acids in the S4 segment that disrupt interactions between the S4 segment and the gating charge transfer center (GCTC). The GCTC separates the intracellular and extracellular water crevices. The disruption of S4–GCTC interactions allows these crevices to communicate and create a fast activating and non-inactivating alternative cation-selective permeation pathway of low conductance, or a gating pore. Gating pore currents have recently been shown to cause periodic paralysis phenotypes. There is also increasing evidence that gating pores are linked to several other familial diseases. For example, gating pores in Nav1.5 and Kv7.2 channels may underlie mixed arrhythmias associated with dilated cardiomyopathy (DCM) phenotypes and peripheral nerve hyperexcitability (PNH), respectively. There is little evidence for the existence of gating pore blockers. Moreover, it is known that a number of toxins bind to the VSD of a specific domain of Na+ channels. These toxins may thus modulate gating pore currents. This focus on the VSD motif opens up a new area of research centered on developing molecules to treat a number of cell excitability disorders such as epilepsy, cardiac arrhythmias, and pain. The purpose of the present review is to summarize existing knowledge of the pathophysiology, biophysics, and pharmacology of gating pore currents and to serve as a guide for future studies aimed at improving our understanding of gating pores and their pathophysiological roles.
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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 Chahine
- Centre de Recherche de L'Institut Universitaire en Santé Mentale de Québec Quebec City, QC, Canada ; Department of Medicine, Université Laval Quebec City, QC, Canada
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Gosselin-Badaroudine P, Moreau A, Chahine M. Nav 1.5 mutations linked to dilated cardiomyopathy phenotypes: Is the gating pore current the missing link? Channels (Austin) 2013; 8:90-4. [PMID: 24300601 DOI: 10.4161/chan.27179] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Nav 1.5 dysfunctions are commonly linked to rhythms disturbances that include type 3 long QT syndrome (LQT3), Brugada syndrome (BrS), sick sinus syndrome (SSS) and conduction defects. Recently, this channel protein has been also linked to structural heart diseases such as dilated cardiomyopathy (DCM).
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Affiliation(s)
| | - Adrien Moreau
- Centre de recherche; Institut universitaire en santé mentale de Québec; Quebec City, QC Canada
| | - Mohamed Chahine
- Centre de recherche; Institut universitaire en santé mentale de Québec; Quebec City, QC Canada; Department of Medicine; Université Laval; Quebec City, QC Canada
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Zumhagen S, Veldkamp MW, Stallmeyer B, Baartscheer A, Eckardt L, Paul M, Remme CA, Bhuiyan ZA, Bezzina CR, Schulze-Bahr E. A heterozygous deletion mutation in the cardiac sodium channel gene SCN5A with loss- and gain-of-function characteristics manifests as isolated conduction disease, without signs of Brugada or long QT syndrome. PLoS One 2013; 8:e67963. [PMID: 23840796 PMCID: PMC3695936 DOI: 10.1371/journal.pone.0067963] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/23/2013] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The SCN5A gene encodes for the α-subunit of the cardiac sodium channel NaV1.5, which is responsible for the rapid upstroke of the cardiac action potential. Mutations in this gene may lead to multiple life-threatening disorders of cardiac rhythm or are linked to structural cardiac defects. Here, we characterized a large family with a mutation in SCN5A presenting with an atrioventricular conduction disease and absence of Brugada syndrome. METHOD AND RESULTS In a large family with a high incidence of sudden cardiac deaths, a heterozygous SCN5A mutation (p.1493delK) with an autosomal dominant inheritance has been identified. Mutation carriers were devoid of any cardiac structural changes. Typical ECG findings were an increased P-wave duration, an AV-block I° and a prolonged QRS duration with an intraventricular conduction delay and no signs for Brugada syndrome. HEK293 cells transfected with 1493delK showed strongly (5-fold) reduced Na(+) currents with altered inactivation kinetics compared to wild-type channels. Immunocytochemical staining demonstrated strongly decreased expression of SCN5A 1493delK in the sarcolemma consistent with an intracellular trafficking defect and thereby a loss-of-function. In addition, SCN5A 1493delK channels that reached cell membrane showed gain-of-function aspects (slowing of the fast inactivation, reduction in the relative fraction of channels that fast inactivate, hastening of the recovery from inactivation). CONCLUSION In a large family, congregation of a heterozygous SCN5A gene mutation (p.1493delK) predisposes for conduction slowing without evidence for Brugada syndrome due to a predominantly trafficking defect that reduces Na(+) current and depolarization force.
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Affiliation(s)
- Sven Zumhagen
- Institute for Genetics of Heart Diseases, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany.
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King JH, Huang CLH, Fraser JA. Determinants of myocardial conduction velocity: implications for arrhythmogenesis. Front Physiol 2013; 4:154. [PMID: 23825462 PMCID: PMC3695374 DOI: 10.3389/fphys.2013.00154] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/10/2013] [Indexed: 12/19/2022] Open
Abstract
Slowed myocardial conduction velocity (θ) is associated with an increased risk of re-entrant excitation, predisposing to cardiac arrhythmia. θ is determined by the ion channel and physical properties of cardiac myocytes and by their interconnections. Thus, θ is closely related to the maximum rate of action potential (AP) depolarization [(dV/dt)max], as determined by the fast Na+ current (INa); the axial resistance (ra) to local circuit current flow between cells; their membrane capacitances (cm); and to the geometrical relationship between successive myocytes within cardiac tissue. These determinants are altered by a wide range of pathophysiological conditions. Firstly, INa is reduced by the impaired Na+ channel function that arises clinically during heart failure, ischemia, tachycardia, and following treatment with class I antiarrhythmic drugs. Such reductions also arise as a consequence of mutations in SCN5A such as those occurring in Lenègre disease, Brugada syndrome (BrS), sick sinus syndrome, and atrial fibrillation (AF). Secondly, ra, may be increased due to gap junction decoupling following ischemia, ventricular hypertrophy, and heart failure, or as a result of mutations in CJA5 found in idiopathic AF and atrial standstill. Finally, either ra or cm could potentially be altered by fibrotic change through the resultant decoupling of myocyte–myocyte connections and coupling of myocytes with fibroblasts. Such changes are observed in myocardial infarction and cardiomyopathy or following mutations in MHC403 and SCN5A resulting in hypertrophic cardiomyopathy (HCM) or Lenègre disease, respectively. This review defines and quantifies the determinants of θ and summarizes experimental evidence that links changes in these determinants with reduced myocardial θ and arrhythmogenesis. It thereby identifies the diverse pathophysiological conditions in which abnormal θ may contribute to arrhythmia.
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Affiliation(s)
- James H King
- Physiological Laboratory, Department of Physiology, Development and Neuroscience, University of Cambridge Cambridge, UK
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Woods JO, Singh-Blom UM, Laurent JM, McGary KL, Marcotte EM. Prediction of gene-phenotype associations in humans, mice, and plants using phenologs. BMC Bioinformatics 2013; 14:203. [PMID: 23800157 PMCID: PMC3704650 DOI: 10.1186/1471-2105-14-203] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 05/24/2013] [Indexed: 12/19/2022] Open
Abstract
Background Phenotypes and diseases may be related to seemingly dissimilar phenotypes in other species by means of the orthology of underlying genes. Such “orthologous phenotypes,” or “phenologs,” are examples of deep homology, and may be used to predict additional candidate disease genes. Results In this work, we develop an unsupervised algorithm for ranking phenolog-based candidate disease genes through the integration of predictions from the k nearest neighbor phenologs, comparing classifiers and weighting functions by cross-validation. We also improve upon the original method by extending the theory to paralogous phenotypes. Our algorithm makes use of additional phenotype data — from chicken, zebrafish, and E. coli, as well as new datasets for C. elegans — establishing that several types of annotations may be treated as phenotypes. We demonstrate the use of our algorithm to predict novel candidate genes for human atrial fibrillation (such as HRH2, ATP4A, ATP4B, and HOPX) and epilepsy (e.g., PAX6 and NKX2-1). We suggest gene candidates for pharmacologically-induced seizures in mouse, solely based on orthologous phenotypes from E. coli. We also explore the prediction of plant gene–phenotype associations, as for the Arabidopsis response to vernalization phenotype. Conclusions We are able to rank gene predictions for a significant portion of the diseases in the Online Mendelian Inheritance in Man database. Additionally, our method suggests candidate genes for mammalian seizures based only on bacterial phenotypes and gene orthology. We demonstrate that phenotype information may come from diverse sources, including drug sensitivities, gene ontology biological processes, and in situ hybridization annotations. Finally, we offer testable candidates for a variety of human diseases, plant traits, and other classes of phenotypes across a wide array of species.
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Affiliation(s)
- John O Woods
- Center for Systems & Synthetic Biology, Institute for Cellular & Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA
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Huttner IG, Trivedi G, Jacoby A, Mann SA, Vandenberg JI, Fatkin D. A transgenic zebrafish model of a human cardiac sodium channel mutation exhibits bradycardia, conduction-system abnormalities and early death. J Mol Cell Cardiol 2013; 61:123-32. [PMID: 23791817 DOI: 10.1016/j.yjmcc.2013.06.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 06/05/2013] [Accepted: 06/11/2013] [Indexed: 12/11/2022]
Abstract
The recent exponential increase in human genetic studies due to the advances of next generation sequencing has generated unprecedented numbers of new gene variants. Determining which of these are causative of human disease is a major challenge. In-vitro studies and murine models have been used to study inherited cardiac arrhythmias but have several limitations. Zebrafish models provide an attractive alternative for modeling human heart disease due to similarities in cardiac electrophysiology and contraction, together with ease of genetic manipulation, external development and optical transparency. Although zebrafish cardiac mutants and morphants have been widely used to study loss and knockdown of zebrafish gene function, the phenotypic effects of human dominant-negative gene mutations expressed in transgenic zebrafish have not been evaluated. The aim of this study was to generate and characterize a transgenic zebrafish arrhythmia model harboring the pathogenic human cardiac sodium channel mutation SCN5A-D1275N, that has been robustly associated with a range of cardiac phenotypes, including conduction disease, sinus node dysfunction, atrial and ventricular arrhythmias, and dilated cardiomyopathy in humans and in mice. Stable transgenic fish with cardiac expression of human SCN5A were generated using Tol2-mediated transgenesis and cardiac phenotypes were analyzed using video microscopy and ECG. Here we show that transgenic zebrafish expressing the SCN5A-D1275N mutation, but not wild-type SCN5A, exhibit bradycardia, conduction-system abnormalities and premature death. We furthermore show that SCN5A-WT, and to a lesser degree SCN5A-D1275N, are able to compensate the loss of endogenous zebrafish cardiac sodium channels, indicating that the basic pathways, through which SCN5A acts, are conserved in teleosts. This proof-of-principle study suggests that zebrafish may be highly useful in vivo models to differentiate functional from benign human genetic variants in cardiac ion channel genes in a time- and cost-efficient manner. This article is part of a Special Issue entitled "Na(+) Regulation in Cardiac Myocytes".
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Affiliation(s)
- Inken G Huttner
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
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Abstract
Atrial fibrillation (AF) is the most-common sustained arrhythmia observed in clinical practice, but response to therapy is highly variable between patients. Current drug therapies to suppress AF are incompletely and unpredictably effective and carry substantial risk of proarrhythmia and noncardiac toxicities. The limited success of therapy for AF is partially the result of heterogeneity of the underlying substrate, interindividual differences in disease mechanisms, and our inability to predict response to therapies in individual patients. In this Review, we discuss the evidence that variability in response to drug therapy is also conditioned by the underlying genetic substrate for AF. Increased susceptibility to AF is mediated through diverse genetic mechanisms, including modulation of the atrial action-potential duration, conduction slowing, and impaired cell-to-cell communication, as well as novel mechanisms, such as regulation of signalling proteins important in the pathogenesis of AF. However, the translation of genetic data to the care of the patients with AF has been limited because of poor understanding of the underlying mechanisms associated with common AF-susceptibility loci, a dearth of prospective, adequately powered studies, and the challenges associated with determining efficacy of antiarrhythmic drugs. What is apparent, however, is the need for appropriately designed, genotype-directed clinical trials.
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Affiliation(s)
- Dawood Darbar
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, 2215B Garland Avenue, Nashville, TN 37323-6602, USA.
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Lubitz SA, Ellinor PT. Personalized medicine and atrial fibrillation: will it ever happen? BMC Med 2012; 10:155. [PMID: 23210687 PMCID: PMC3568716 DOI: 10.1186/1741-7015-10-155] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 12/04/2012] [Indexed: 12/18/2022] Open
Abstract
Atrial fibrillation (AF) is a common arrhythmia of substantial public health importance. Recent evidence demonstrates a heritable component underlying AF, and genetic discoveries have identified common variants associated with the arrhythmia. Ultimately one hopes that the consideration of genetic variation in clinical practice may enhance care and improve health outcomes. In this review we explore areas of potential clinical utility in AF management including those relating to pharmacogenetics and risk prediction.
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Affiliation(s)
- Steven A Lubitz
- Cardiovascular Research Center and Cardiac Arrhythmia Service, Massachusetts General Hospital, 149 13th Street, 4th Floor, Charlestown, MA 02129, USA.
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Derangeon M, Montnach J, Baró I, Charpentier F. Mouse Models of SCN5A-Related Cardiac Arrhythmias. Front Physiol 2012; 3:210. [PMID: 22737129 PMCID: PMC3381239 DOI: 10.3389/fphys.2012.00210] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 05/29/2012] [Indexed: 12/19/2022] Open
Abstract
Mutations of SCN5A gene, which encodes the α-subunit of the voltage-gated Na+ channel NaV1.5, underlie hereditary cardiac arrhythmic syndromes such as the type 3 long QT syndrome, cardiac conduction diseases, the Brugada syndrome, the sick sinus syndrome, a trial standstill, and numerous overlap syndromes. Patch-clamp studies in heterologous expression systems have provided important information to understand the genotype-phenotype relationships of these diseases. However, they could not clarify how SCN5A mutations can be responsible for such a large spectrum of diseases, for the late age of onset or the progressiveness of some of these diseases and for the overlapping syndromes. Genetically modified mice rapidly appeared as promising tools for understanding the pathophysiological mechanisms of cardiac SCN5A-related arrhythmic syndromes and several mouse models have been established. This review presents the results obtained on these models that, for most of them, recapitulate the clinical phenotypes of the patients. This includes two models knocked out for Nav1.5 β1 and β3 auxiliary subunits that are also discussed. Despite their own limitations that we point out, the mouse models still appear as powerful tools to elucidate the pathophysiological mechanisms of SCN5A-related diseases and offer the opportunity to investigate the secondary cellular consequences of SCN5A mutations such as the expression remodeling of other genes. This points out the potential role of these genes in the overall human phenotype. Finally, they constitute useful tools for addressing the role of genetic and environmental modifiers on cardiac electrical activity.
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Chen L, Zhang W, Fang C, Jiang S, Shu C, Cheng H, Li F, Li H. Polymorphism H558R in the Human Cardiac Sodium Channel SCN5A Gene is Associated with Atrial Fibrillation. J Int Med Res 2011; 39:1908-16. [DOI: 10.1177/147323001103900535] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) is one of the most common sustained cardiac arrhythmias and its prevalence is increasing worldwide in line with the growing elderly population. Many single nucleotide polymorphisms and mutations are associated with AF, including the common loss-of-function histidine-558-to-arginine (H558R) polymorphism of the human cardiac sodium channel, voltage-gated, type V, α subunit (encoded by the SCN5A gene). The H558R polymorphism results from the T-C transition in the SCN5A gene. This study recruited 135 patients with AF and 296 healthy controls to scan for and perform targeted genotyping of the H558R polymorphism of the SCN5A gene. Logistic regression analysis showed that the TC and CC genotypes (i.e. genotypes that result in the R558 polymorphism) were significantly associated with an increased risk of developing AF. The R558 polymorphism conferred an odds ratio for AF of 3.451 (95% confidence interval 1.718, 6.931). In conclusion, this study provided evidence for the role of the H558R polymorphism of the SCN5A gene in increasing the susceptibility to AF.
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Affiliation(s)
- L Chen
- Department of Biochemistry and Molecular Biology, Basic Medical Science College, Harbin Medical University, Harbin, China
- Department of Clinical Laboratory, Harbin Red Cross Central Hospital, Harbin, China
| | - W Zhang
- Department of Biochemistry and Molecular Biology, Basic Medical Science College, Harbin Medical University, Harbin, China
| | - C Fang
- Department of Biochemistry and Molecular Biology, Basic Medical Science College, Harbin Medical University, Harbin, China
| | - S Jiang
- Department of Biochemistry and Molecular Biology, Basic Medical Science College, Harbin Medical University, Harbin, China
| | - C Shu
- Department of Biochemistry and Molecular Biology, Basic Medical Science College, Harbin Medical University, Harbin, China
| | - H Cheng
- Department of Biochemistry and Molecular Biology, Basic Medical Science College, Harbin Medical University, Harbin, China
| | - F Li
- Department of Biochemistry and Molecular Biology, Basic Medical Science College, Harbin Medical University, Harbin, China
| | - H Li
- Department of Biochemistry and Molecular Biology, Basic Medical Science College, Harbin Medical University, Harbin, China
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Watanabe H, Yang T, Stroud DM, Lowe JS, Harris L, Atack TC, Wang DW, Hipkens SB, Leake B, Hall L, Kupershmidt S, Chopra N, Magnuson MA, Tanabe N, Knollmann BC, George AL, Roden DM. Striking In vivo phenotype of a disease-associated human SCN5A mutation producing minimal changes in vitro. Circulation 2011; 124:1001-11. [PMID: 21824921 DOI: 10.1161/circulationaha.110.987248] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND The D1275N SCN5A mutation has been associated with a range of unusual phenotypes, including conduction disease and dilated cardiomyopathy, as well as atrial and ventricular tachyarrhythmias. However, when D1275N is studied in heterologous expression systems, most studies show near-normal sodium channel function. Thus, the relationship of the variant to the clinical phenotypes remains uncertain. METHODS AND RESULTS We identified D1275N in a patient with atrial flutter, atrial standstill, conduction disease, and sinus node dysfunction. There was no major difference in biophysical properties between wild-type and D1275N channels expressed in Chinese hamster ovary cells or tsA201 cells in the absence or presence of β1 subunits. To determine D1275N function in vivo, the Scn5a locus was modified to knock out the mouse gene, and the full-length wild-type (H) or D1275N (DN) human SCN5A cDNAs were then inserted at the modified locus by recombinase mediated cassette exchange. Mice carrying the DN allele displayed slow conduction, heart block, atrial fibrillation, ventricular tachycardia, and a dilated cardiomyopathy phenotype, with no significant fibrosis or myocyte disarray on histological examination. The DN allele conferred gene-dose-dependent increases in SCN5A mRNA abundance but reduced sodium channel protein abundance and peak sodium current amplitudes (H/H, 41.0±2.9 pA/pF at -30 mV; DN/H, 19.2±3.1 pA/pF, P<0.001 vs. H/H; DN/DN, 9.3±1.1 pA/pF, P<0.001 versus H/H). CONCLUSIONS Although D1275N produces near-normal currents in multiple heterologous expression experiments, our data establish this variant as a pathological mutation that generates conduction slowing, arrhythmias, and a dilated cardiomyopathy phenotype by reducing cardiac sodium current.
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Affiliation(s)
- Hiroshi Watanabe
- Department of Medicine, Vanderbilt University School of Medicine, 2215B Garland Ave, 1285 MRBIV Light Hall, Nashville, TN 37232-0575, USA
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Walzik S, Schroeter A, Benndorf K, Zimmer T. Alternative splicing of the cardiac sodium channel creates multiple variants of mutant T1620K channels. PLoS One 2011; 6:e19188. [PMID: 21552533 PMCID: PMC3084281 DOI: 10.1371/journal.pone.0019188] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 03/22/2011] [Indexed: 12/19/2022] Open
Abstract
Alternative splicing creates several Nav1.5 transcripts in the mammalian myocardium and in various other tissues including brain, dorsal root ganglia, breast cancer cells as well as neuronal stem cell lines. In total nine Nav1.5 splice variants have been discovered. Four of them, namely Nav1.5a, Nav1.5c, Nav1.5d, and Nav1.5e, generate functional channels in heterologous expression systems. The significance of alternatively spliced transcripts for cardiac excitation, in particular their role in SCN5A channelopathies, is less well understood. In the present study, we systematically investigated electrophysiological properties of mutant T1620K channels in the background of all known functional Nav1.5 splice variants in HEK293 cells. This mutation has been previously associated with two distinct cardiac excitation disorders: with long QT syndrome type 3 (LQT3) and isolated cardiac conduction disease (CCD). When investigating the effect of the T1620K mutation, we noticed similar channel defects in the background of hNav1.5, hNav1.5a, and hNav1.5c. In contrast, the hNav1.5d background produced differential effects: In the mutant channel, some gain-of-function features did not emerge, whereas loss-of-function became more pronounced. In case of hNav1.5e, the neonatal variant of hNav1.5, both the splice variant itself as well as the corresponding mutant channel showed electrophysiological properties that were distinct from the wild-type and mutant reference channels, hNav1.5 and T1620K, respectively. In conclusion, our data show that alternative splicing is a mechanism capable of generating a variety of functionally distinct wild-type and mutant hNav1.5 channels. Thus, the cellular splicing machinery is a potential player affecting genotype-phenotype correlations in SCN5A channelopathies.
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Affiliation(s)
- Stefan Walzik
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - Annett Schroeter
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - Klaus Benndorf
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - Thomas Zimmer
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University, Jena, Germany
- * E-mail:
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Capulzini L, Brugada P, Brugada J, Brugada R. Arrhythmia and right heart disease: from genetic basis to clinical practice. Rev Esp Cardiol 2011; 63:963-83. [PMID: 20738941 DOI: 10.1016/s1885-5857(10)70190-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Historically, left ventricular cardiomyopathy and coronary heart disease have been regarded as the main causes of ventricular arrhythmia and sudden cardiac death. However, within last two decades, arrhythmias originating from the right ventricle have begun to attract the attention of the scientific world for a number of reasons. Ventricular arrhythmias originating from the right ventricle usually affect younger patients and can lead to sudden cardiac death. The pathophysiologic mechanism of these arrhythmias is not fully understood, which can leave room for a range of different interpretations. Moreover, the intriguing world of genetics is increasingly being drawn into the pathogenesis, diagnosis and prognosis of some of these arrhythmias. This review considers the pathogenesis, diagnosis and treatment of arrhythmogenic right ventricular cardiomyopathy or dysplasia (ARVD), Brugada syndrome, right ventricular outflow tract ventricular tachycardia, and arrhythmias in the right side of the heart due to congenital heart disease. In addition, because ventricular arrhythmias associated with right ventricular heart diseases such as Brugada syndrome and ARVD can explain up to 10-30% of sudden cardiac deaths in young adults in the general population and an even greater percentage in young athletes, this article contains a brief analysis of screening tests used before participation in sports, life-style modification, and treatment options for athletes affected by these conduction disorders.
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Affiliation(s)
- Lucio Capulzini
- Heart Rhythm Management Centre, UZ-Brussels-VUB, Bruselas, Bélgica.
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Abstract
Progressive cardiac conduction disease (PCCD), a source of considerable morbidity, comprises a heterogeneous group of conditions resulting from genetic predisposition, environmental modifiers, and other physiologic determinants, including aging. The genetic factors include numerous mutations and variants within the cardiac sodium channel gene, SCN5A. The electrocardiographic phenotype has variable penetrance and is associated with appearances ranging from an isolated conduction disorder to an association with tachyarrhythmias and clinically significant cardiomyopathy. A heterozygotic Scn5a mouse model provides evidence that PCCD may lead to cardiac remodeling consistent with clinical observations in addition to slowing of intracardiac conduction. PCCD has also been associated with the altered expression of genes encoding other proteins involved in impulse propagation, including those responsible for Ca2+- activated ion channels and cytoskeletal components, both in the presence or absence of structural abnormalities.
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Affiliation(s)
- Claire A Martin
- The Physiology Department, University of Cambridge, Downing Site, Cambridge CB2 3EG, UK
| | - Christopher L-H Huang
- The Physiology Department, University of Cambridge, Downing Site, Cambridge CB2 3EG, UK
| | - Andrew A Grace
- Department of Biochemistry, University of Cambridge, Downing Site, CB2 1QW, UK; Department of Cardiology, Papworth Hospital, Cambridge CB23 3RE, UK
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Lopez KN, Decker JA, Friedman RA, Kim JJ. Homozygous mutation in SCN5A associated with atrial quiescence, recalcitrant arrhythmias, and poor capture thresholds. Heart Rhythm 2010; 8:471-3. [PMID: 20950709 DOI: 10.1016/j.hrthm.2010.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 10/10/2010] [Indexed: 11/17/2022]
Affiliation(s)
- Keila N Lopez
- Section of Pediatric Cardiology, Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, Texas 77030, USA.
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Strieper MJ, Frias P, Fischbach P, Costello L, Campbell RM. Catheter Ablation of Primary Supraventricular Tachycardia Substrate Presenting as Atrial Fibrillation in Adolescents. CONGENIT HEART DIS 2010; 5:465-9. [DOI: 10.1111/j.1747-0803.2009.00368.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Capulzini L, Brugada P, Brugada J, Brugada R. Arritmias y enfermedades del corazón derecho: de las bases genéticas a la clínica. Rev Esp Cardiol 2010. [DOI: 10.1016/s0300-8932(10)70208-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Multiple loss-of-function mechanisms contribute to SCN5A-related familial sick sinus syndrome. PLoS One 2010; 5:e10985. [PMID: 20539757 PMCID: PMC2881866 DOI: 10.1371/journal.pone.0010985] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Accepted: 04/26/2010] [Indexed: 12/11/2022] Open
Abstract
Background To identify molecular mechanisms underlying SCN5A-related sick sinus syndrome (SSS), a rare type of SSS, in parallel experiments we elucidated the electrophysiological properties and the cell surface localization of thirteen human Nav1.5 (hNav1.5) mutant channels previously linked to this disease. Methodology/Principal Findings Mutant hNav1.5 channels expressed by HEK293 cells and Xenopus oocytes were investigated by whole-cell patch clamp and two-microelectrode voltage clamp, respectively. HEK293 cell surface biotinylation experiments quantified the fraction of correctly targeted channel proteins. Our data suggested three distinct mutant channel subtypes: Group 1 mutants (L212P, P1298L, DelF1617, R1632H) gave peak current densities and cell surface targeting indistinguishable from wild-type hNav1.5. Loss-of-function of these mutants resulted from altered channel kinetics, including a negative shift of steady-state inactivation and a reduced voltage dependency of open-state inactivation. Group 2 mutants (E161K, T220I, D1275N) gave significantly reduced whole-cell currents due to impaired cell surface localization (D1275N), altered channel properties at unchanged cell surface localization (T220I), or a combination of both (E161K). Group 3 mutant channels were non-functional, due to an almost complete lack of protein at the plasma membrane (T187I, W1421X, K1578fs/52, R1623X) or a probable gating/permeation defect with normal surface localisation (R878C, G1408R). Conclusions/Significance This study indicates that multiple molecular mechanisms, including gating abnormalities, trafficking defects, or a combination of both, are responsible for SCN5A-related familial SSS.
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Gui J, Wang T, Trump D, Zimmer T, Lei M. Mutation-specific effects of polymorphism H558R in SCN5A-related sick sinus syndrome. J Cardiovasc Electrophysiol 2010; 21:564-73. [PMID: 20384651 DOI: 10.1111/j.1540-8167.2010.01762.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Mutations in SCN5A, the gene encoding alpha subunit of cardiac type sodium channel, Na(v)1.5, lead to familial sick sinus syndrome (SSS). Although several molecular mechanisms for this genetic condition have been explored, the underlying mechanisms for the variable genotype-phenotype relationships have not been well addressed. One of the important contributors to such relationships is the genetic background such as single-nucleotide polymorphisms. METHODS AND RESULTS To clarify the effects of a common polymorphism in SCN5A gene, H558R, on SCN5A-related SSS phenotype, we investigated the electrophysiological properties of all of the 13 known SSS-related hNa(v)1.5 mutant channels on both H558 and R558 background. Electrophysiological properties of hNa(v)1.5 mutant channels were investigated by the whole-cell patch clamp technique in HEK293 cells. When peak currents were affected by the mutation, cell surface biotinylation was performed to quantify the fraction of correctly cell membrane-targeted mutant channels. Loss-of-function defect of D1275N in SCN5A was rescued by R558 through enhancing cell surface targeting and improving steady-state activation of the mutant channels. In contrast, the defects of mutants E161K, P1298L, and R1632H were aggravated in the R558 background, mainly due to the reduced steady-state availability of mutant channels. The electrophysiological properties of the remaining SSS-related hNa(v)1.5 mutants including the missense mutants (L212P, T220I, DelF1617, T187I, R878C, G1408R), and the truncated mutants (W1421X, K1578fs/52, R1623X) were not significantly affected by H558R. CONCLUSION We conclude that polymorphism H558R has mutation-specific effects on SCN5A-related SSS. Our data highlight the importance of common genetic variants in modulating phenotypes of genetic diseases.
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Affiliation(s)
- Junhong Gui
- Cardiovascular Research Group, School of Clinical and Laboratory Sciences, University of Manchester, Manchester, UK
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