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Starnes L, Hall A, Etal D, Cavallo AL, Grabowski P, Gallon J, Kha M, Hicks R, Pointon A. RYR2 deficient human model identifies calcium handling and metabolic dysfunction impacting pharmacological responses. Front Cardiovasc Med 2024; 11:1357315. [PMID: 39041002 PMCID: PMC11260679 DOI: 10.3389/fcvm.2024.1357315] [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: 12/17/2023] [Accepted: 06/18/2024] [Indexed: 07/24/2024] Open
Abstract
Creation of disease models utilizing hiPSCs in combination with CRISPR/Cas9 gene editing enable mechanistic insights into differential pharmacological responses. This allows translation of efficacy and safety findings from a healthy to a diseased state and provides a means to predict clinical outcome sooner during drug discovery. Calcium handling disturbances including reduced expression levels of the type 2 ryanodine receptor (RYR2) are linked to cardiac dysfunction; here we have created a RYR2 deficient human cardiomyocyte model that mimics some aspects of heart failure. RYR2 deficient cardiomyocytes show differential pharmacological responses to L-type channel calcium inhibitors. Phenotypic and proteomic characterization reveal novel molecular insights with altered expression of structural proteins including CSRP3, SLMAP, and metabolic changes including upregulation of the pentose phosphate pathway and increased sensitivity to redox alterations. This genetically engineered in vitro cardiovascular model of RYR2 deficiency supports the study of pharmacological responses in the context of calcium handling and metabolic dysfunction enabling translation of drug responses from healthy to perturbed cellular states.
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Affiliation(s)
- Linda Starnes
- Safety Sciences, Clinical Pharmacology & Safety Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Andrew Hall
- Safety Sciences, Clinical Pharmacology & Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | - Damla Etal
- Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | | | - Piotr Grabowski
- Imaging and Data Analytics, Clinical Pharmacology & Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | - John Gallon
- Imaging and Data Analytics, Clinical Pharmacology & Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
| | - Michelle Kha
- Safety Sciences, Clinical Pharmacology & Safety Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Ryan Hicks
- BioPharmaceuticals R&D Cell Therapy Department, Research and Early Development, Cardiovascular, Renal, and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- School of Cardiovascular and Metabolic Medicine & Sciences, King’s College London, London, United Kingdom
| | - Amy Pointon
- Safety Sciences, Clinical Pharmacology & Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom
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2
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Moore OM, Aguilar-Sanchez Y, Lahiri SK, Hulsurkar MM, Alberto Navarro-Garcia J, Word TA, Keefe JA, Barazi D, Munivez EM, Moore CT, Parthasarathy V, Davidson J, Lagor WR, Park SH, Bao G, Miyake CY, Wehrens XHT. Long-term efficacy and safety of cardiac genome editing for catecholaminergic polymorphic ventricular tachycardia. THE JOURNAL OF CARDIOVASCULAR AGING 2024; 4:8. [PMID: 38464671 PMCID: PMC10919902 DOI: 10.20517/jca.2023.42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Introduction Heterozygous autosomal-dominant single nucleotide variants in RYR2 account for 60% of cases of catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited arrhythmia disorder associated with high mortality rates. CRISPR/Cas9-mediated genome editing is a promising therapeutic approach that can permanently cure the disease by removing the mutant RYR2 allele. However, the safety and long-term efficacy of this strategy have not been established in a relevant disease model. Aim The purpose of this study was to assess whether adeno-associated virus type-9 (AAV9)-mediated somatic genome editing could prevent ventricular arrhythmias by removal of the mutant allele in mice that are heterozygous for Ryr2 variant p.Arg176Gln (R176Q/+). Methods and Results Guide RNA and SaCas9 were delivered using AAV9 vectors injected subcutaneously in 10-day-old mice. At 6 weeks after injection, R176Q/+ mice had a 100% reduction in ventricular arrhythmias compared to controls. When aged to 12 months, injected R176Q/+ mice maintained a 100% reduction in arrhythmia induction. Deep RNA sequencing revealed the formation of insertions/deletions at the target site with minimal off-target editing on the wild-type allele. Consequently, CRISPR/SaCas9 editing resulted in a 45% reduction of total Ryr2 mRNA and a 38% reduction in RyR2 protein. Genome editing was well tolerated based on serial echocardiography, revealing unaltered cardiac function and structure up to 12 months after AAV9 injection. Conclusion Taken together, AAV9-mediated CRISPR/Cas9 genome editing could efficiently disrupt the mutant Ryr2 allele, preventing lethal arrhythmias while preserving normal cardiac function in the R176Q/+ mouse model of CPVT.
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Affiliation(s)
- Oliver M. Moore
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yuriana Aguilar-Sanchez
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Satadru K. Lahiri
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mohit M. Hulsurkar
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - J. Alberto Navarro-Garcia
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Tarah A. Word
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Joshua A. Keefe
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Dean Barazi
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Elda M. Munivez
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Charles T. Moore
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Vaidya Parthasarathy
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jaysón Davidson
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - William R. Lagor
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - So Hyun Park
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Gang Bao
- Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Christina Y. Miyake
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
| | - Xander H. T. Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
- Department of Medicine (Cardiology), Baylor College of Medicine, Houston, TX 77030, USA
- Center for Space Medicine, Baylor College of Medicine, Houston, TX 77030, USA
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3
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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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Tian S, Zhong X, Wang H, Wei J, Guo W, Wang R, Paul Estillore J, Napolitano C, Duff HH, Ilhan E, Knight LM, Lloyd MS, Roberts JD, Priori SG, Chen SRW. RyR2 C-terminal truncating variants identified in patients with arrhythmic phenotypes exert a dominant negative effect through formation of wildtype-truncation heteromers. Biochem J 2023; 480:1379-1395. [PMID: 37492947 DOI: 10.1042/bcj20230254] [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: 06/19/2023] [Revised: 07/19/2023] [Accepted: 07/25/2023] [Indexed: 07/27/2023]
Abstract
Gain-of-function missense variants in the cardiac ryanodine receptor (RyR2) are linked to catecholaminergic polymorphic ventricular tachycardia (CPVT), whereas RyR2 loss-of-function missense variants cause Ca2+ release deficiency syndrome (CRDS). Recently, truncating variants in RyR2 have also been associated with ventricular arrhythmias (VAs) and sudden cardiac death. However, there are limited insights into the potential clinical relevance and in vitro functional impact of RyR2 truncating variants. We performed genetic screening of patients presenting with syncope, VAs, or unexplained sudden death and in vitro characterization of the expression and function of RyR2 truncating variants in HEK293 cells. We identified two previously unknown RyR2 truncating variants (Y4591Ter and R4663Ter) and one splice site variant predicted to result in a frameshift and premature termination (N4717 + 15Ter). These 3 new RyR2 truncating variants and a recently reported RyR2 truncating variant, R4790Ter, were generated and functionally characterized in vitro. Immunoprecipitation and immunoblotting analyses showed that all 4 RyR2 truncating variants formed heteromers with the RyR2-wildtype (WT) protein. Each of these C-terminal RyR2 truncations was non-functional and suppressed [3H]ryanodine binding to RyR2-WT and RyR2-WT mediated store overload induced spontaneous Ca2+ release activity in HEK293 cells. The expression of these RyR2 truncating variants in HEK293 cells was markedly reduced compared with that of the full-length RyR2 WT protein. Our data indicate that C-terminal RyR2 truncating variants are non-functional and can exert a dominant negative impact on the function of the RyR2 WT protein through formation of heteromeric WT/truncation complex.
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Affiliation(s)
- Shanshan Tian
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Xiaowei Zhong
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Hui Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
- School of Medicine, Northwest University, Xi'an 710069, China
| | - Wenting Guo
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Carlo Napolitano
- European Reference Network 'ERN GUARD-Heart', Amsterdam, Netherlands
- Division of Cardiology and Molecular Cardiology, IRCCS Maugeri Foundation-University of Pavia, 27100 Pavia, Italy
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Henry H Duff
- Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Erkan Ilhan
- Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Linda M Knight
- Children's Healthcare of Atlanta Cardiology, Atlanta, Georgia, U.S.A
| | - Michael S Lloyd
- Emory University School of Medicine, Atlanta, Georgia, U.S.A
| | - Jason D Roberts
- Population Health Research Institute, McMaster University, and Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Silvia G Priori
- European Reference Network 'ERN GUARD-Heart', Amsterdam, Netherlands
- Division of Cardiology and Molecular Cardiology, IRCCS Maugeri Foundation-University of Pavia, 27100 Pavia, Italy
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Molecular Cardiology Laboratory, Centro de Investigaciones Cardiovasculares Carlos III, 28029 Madrid, Spain
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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5
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Djemai M, Cupelli M, Boutjdir M, Chahine M. Optical Mapping of Cardiomyocytes in Monolayer Derived from Induced Pluripotent Stem Cells. Cells 2023; 12:2168. [PMID: 37681899 PMCID: PMC10487143 DOI: 10.3390/cells12172168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/21/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Optical mapping is a powerful imaging technique widely adopted to measure membrane potential changes and intracellular Ca2+ variations in excitable tissues using voltage-sensitive dyes and Ca2+ indicators, respectively. This powerful tool has rapidly become indispensable in the field of cardiac electrophysiology for studying depolarization wave propagation, estimating the conduction velocity of electrical impulses, and measuring Ca2+ dynamics in cardiac cells and tissues. In addition, mapping these electrophysiological parameters is important for understanding cardiac arrhythmia mechanisms. In this review, we delve into the fundamentals of cardiac optical mapping technology and its applications when applied to hiPSC-derived cardiomyocytes and discuss related advantages and challenges. We also provide a detailed description of the processing and analysis of optical mapping data, which is a crucial step in the study of cardiac diseases and arrhythmia mechanisms for extracting and comparing relevant electrophysiological parameters.
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Affiliation(s)
- Mohammed Djemai
- CERVO Brain Research Center, Institut Universitaire en Santé Mentale de Québec, Quebec City, QC G1J 2G3, Canada
| | - Michael Cupelli
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY 11209, USA
- Department of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Health Sciences University, New York, NY 11203, USA
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY 11209, USA
- Department of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Health Sciences University, New York, NY 11203, USA
- Department of Medicine, NYU School of Medicine, New York, NY 10016, USA
| | - Mohamed Chahine
- CERVO Brain Research Center, Institut Universitaire en Santé Mentale de Québec, Quebec City, QC G1J 2G3, Canada
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC G1V 0A6, Canada
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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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Matos-Nieves A, Manivannan S, Majumdar U, McBride KL, White P, Garg V. A Multi-Omics Approach Using a Mouse Model of Cardiac Malformations for Prioritization of Human Congenital Heart Disease Contributing Genes. Front Cardiovasc Med 2021; 8:683074. [PMID: 34504875 PMCID: PMC8421733 DOI: 10.3389/fcvm.2021.683074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 07/22/2021] [Indexed: 01/22/2023] Open
Abstract
Congenital heart disease (CHD) is the most common type of birth defect, affecting ~1% of all live births. Malformations of the cardiac outflow tract (OFT) account for ~30% of all CHD and include a range of CHDs from bicuspid aortic valve (BAV) to tetralogy of Fallot (TOF). We hypothesized that transcriptomic profiling of a mouse model of CHD would highlight disease-contributing genes implicated in congenital cardiac malformations in humans. To test this hypothesis, we utilized global transcriptional profiling differences from a mouse model of OFT malformations to prioritize damaging, de novo variants identified from exome sequencing datasets from published cohorts of CHD patients. Notch1 +/- ; Nos3 -/- mice display a spectrum of cardiac OFT malformations ranging from BAV, semilunar valve (SLV) stenosis to TOF. Global transcriptional profiling of the E13.5 Notch1 +/- ; Nos3 -/- mutant mouse OFTs and wildtype controls was performed by RNA sequencing (RNA-Seq). Analysis of the RNA-Seq dataset demonstrated genes belonging to the Hif1α, Tgf-β, Hippo, and Wnt signaling pathways were differentially expressed in the mutant OFT. Mouse to human comparative analysis was then performed to determine if patients with TOF and SLV stenosis display an increased burden of damaging, genetic variants in gene homologs that were dysregulated in Notch1 +/- ; Nos3 -/- OFT. We found an enrichment of de novo variants in the TOF population among the 1,352 significantly differentially expressed genes in Notch1 +/- ; Nos3 -/- mouse OFT but not the SLV population. This association was not significant when comparing only highly expressed genes in the murine OFT to de novo variants in the TOF population. These results suggest that transcriptomic datasets generated from the appropriate temporal, anatomic and cellular tissues from murine models of CHD may provide a novel approach for the prioritization of disease-contributing genes in patients with CHD.
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Affiliation(s)
- Adrianna Matos-Nieves
- Center for Cardiovascular Research and Heart Center, Nationwide Children's Hospital, Columbus, OH, United States
| | - Sathiyanarayanan Manivannan
- Center for Cardiovascular Research and Heart Center, Nationwide Children's Hospital, Columbus, OH, United States
| | - Uddalak Majumdar
- Center for Cardiovascular Research and Heart Center, Nationwide Children's Hospital, Columbus, OH, United States
| | - Kim L. McBride
- Center for Cardiovascular Research and Heart Center, Nationwide Children's Hospital, Columbus, OH, United States
- Department of Pediatrics, Ohio State University, Columbus, OH, United States
| | - Peter White
- Department of Pediatrics, Ohio State University, Columbus, OH, United States
- The Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, United States
| | - Vidu Garg
- Center for Cardiovascular Research and Heart Center, Nationwide Children's Hospital, Columbus, OH, United States
- Department of Pediatrics, Ohio State University, Columbus, OH, United States
- Department of Molecular Genetics, Ohio State University, Columbus, OH, United States
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8
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Ma MG, Liu XR, Wu Y, Wang J, Li BM, Shi YW, Su T, Li B, Liu DT, Yi YH, Liao WP. RYR2 Mutations Are Associated With Benign Epilepsy of Childhood With Centrotemporal Spikes With or Without Arrhythmia. Front Neurosci 2021; 15:629610. [PMID: 33897349 PMCID: PMC8058200 DOI: 10.3389/fnins.2021.629610] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 02/19/2021] [Indexed: 11/13/2022] Open
Abstract
RYR2 encodes ryanodine receptor 2 protein (RYR-2) that is mainly located on endoplasmic reticulum membrane and regulates intracellular calcium concentration. The RYR-2 protein is ubiquitously distributed and highly expressed in the heart and brain. Previous studies have identified the RYR2 mutations in the etiology of arrhythmogenic right ventricular dysplasia 2 and catecholaminergic polymorphic ventricular tachycardia. However, the relationship between RYR2 gene and epilepsy is not determined. In this study, we screened for novel genetic variants in a group of 292 cases (families) with benign epilepsy of childhood with centrotemporal spikes (BECTS) by trio-based whole-exome sequencing. RYR2 mutations were identified in five cases with BECTS, including one heterozygous frameshift mutation (c.14361dup/p.Arg4790Pro fs∗6), two heterozygous missense mutations (c.2353G > A/p.Asp785Asn and c.8574G > A/p.Met2858Ile), and two pairs of compound heterozygous mutations (c.4652A > G/p.Asn1551Ser and c.11693T > C/p.Ile3898Thr, c.7469T > C/p.Val2490Ala and c.12770G > A/p.Arg4257Gln, respectively). Asp785Asn was a de novo missense mutation. All the missense mutations were suggested to be damaging by at least three web-based prediction tools. These mutations do not present or at low minor allele frequency in gnomAD database and present statistically higher frequency in the cohort of BECTS than in the control populations of gnomAD. Asp785Asn, Asn1551Ser, and Ile3898Thr were predicted to affect hydrogen bonds with surrounding amino acids. Three affected individuals had arrhythmia (sinus arrhythmia and occasional atrial premature). The two probands with compound heterozygous missense mutations presented mild cardiac structural abnormalities. Strong evidence from ClinGen Clinical Validity Framework suggested an association between RYR2 variants and epilepsy. This study suggests that RYR2 gene is potentially a candidate pathogenic gene of BECTS. More attention should be paid to epilepsy patients with RYR2 mutations, which were associated with arrhythmia and sudden unexpected death in previous reports.
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Affiliation(s)
- Mei-Gang Ma
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China.,Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Xiao-Rong Liu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yuan Wu
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jie Wang
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Bing-Mei Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yi-Wu Shi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Tao Su
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Bin Li
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - De-Tian Liu
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yong-Hong Yi
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Wei-Ping Liao
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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9
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Zhou X, Li A, Lin PH, Zhou J, Ma J. TRIC-A regulates intracellular Ca 2+ homeostasis in cardiomyocytes. Pflugers Arch 2021; 473:547-556. [PMID: 33474637 PMCID: PMC7940156 DOI: 10.1007/s00424-021-02513-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/14/2020] [Accepted: 01/04/2021] [Indexed: 01/26/2023]
Abstract
Trimeric intracellular cation (TRIC) channels have been identified as monovalent cation channels that are located in the ER/SR membrane. Two isoforms discovered in mammals are TRIC-A (TMEM38a) and TRIC-B (TMEM38b). TRIC-B ubiquitously expresses in all tissues, and TRIC-B-/- mice is lethal at the neonatal stage. TRIC-A mainly expresses in excitable cells. TRIC-A-/- mice survive normally but show abnormal SR Ca2+ handling in both skeletal and cardiac muscle cells. Importantly, TRIC-A mutations have been identified in human patients with stress-induced arrhythmia. In the past decade, important discoveries have been made to understand the structure and function of TRIC channels, especially its role in regulating intracellular Ca2+ homeostasis. In this review article, we focus on the potential roles of TRIC-A in regulating cardiac function, particularly its effects on intracellular Ca2+ signaling of cardiomyocytes and discuss the current knowledge gaps.
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Affiliation(s)
- Xinyu Zhou
- Department of Surgery, The Ohio State University Columbus, Columbus, OH, 43210, USA
| | - Ang Li
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, 76019, USA
| | - Pei-Hui Lin
- Department of Surgery, The Ohio State University Columbus, Columbus, OH, 43210, USA
| | - Jingsong Zhou
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, 76019, USA
| | - Jianjie Ma
- Department of Surgery, The Ohio State University Columbus, Columbus, OH, 43210, USA.
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10
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Tester DJ, Bombei HM, Fitzgerald KK, Giudicessi JR, Pitel BA, Thorland EC, Russell BG, Hamrick SK, Kim CSJ, Haglund-Turnquist CM, Johnsrude CL, Atkins DL, Ochoa Nunez LA, Law I, Temple J, Ackerman MJ. Identification of a Novel Homozygous Multi-Exon Duplication in RYR2 Among Children With Exertion-Related Unexplained Sudden Deaths in the Amish Community. JAMA Cardiol 2021; 5:13-18. [PMID: 31913406 DOI: 10.1001/jamacardio.2019.5400] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance The exome molecular autopsy may elucidate a pathogenic substrate for sudden unexplained death. Objective To investigate the underlying cause of multiple sudden deaths in young individuals and sudden cardiac arrests that occurred in 2 large Amish families. Design, Setting, and Participants Two large extended Amish families with multiple sudden deaths in young individuals and sudden cardiac arrests were included in the study. A recessive inheritance pattern was suggested based on an extended family history of sudden deaths in young individuals and sudden cardiac arrests, despite unaffected parents. A family with exercise-associated sudden deaths in young individuals occurring in 4 siblings was referred for postmortem genetic testing using an exome molecular autopsy. Copy number variant (CNV) analysis was performed on exome data using PatternCNV. Chromosomal microarray validated the CNV identified. The nucleotide break points of the CNV were determined by mate-pair sequencing. Samples were collected for this study between November 2004 and June 2019. Main Outcomes and Measures The identification of an underlying genetic cause for sudden deaths in young individuals and sudden cardiac arrests consistent with the recessive inheritance pattern observed in the families. Results A homozygous duplication, involving approximately 26 000 base pairs of intergenic sequence, RYR2's 5'UTR/promoter region, and exons 1 through 4 of RYR2, was identified in all 4 siblings of a family. Multiple distantly related relatives experiencing exertion-related sudden cardiac arrest also had the identical RYR2 homozygous duplication. A second, unrelated family with multiple exertion-related sudden deaths and sudden cardiac arrests in young individuals, with the same homozygous duplication, was identified. Several living, homozygous duplication-positive symptomatic patients from both families had nondiagnostic cardiologic testing, with only occasional ventricular ectopy occurring during exercise stress tests. Conclusions and Relevance In this analysis, we identified a novel, highly penetrant, homozygous multiexon duplication in RYR2 among Amish youths with exertion-related sudden death and sudden cardiac arrest but without an overt phenotype that is distinct from RYR2-mediated catecholaminergic polymorphic ventricular tachycardia. Considering that no cardiac tests reliably identify at-risk individuals and given the high rate of consanguinity in Amish families, identification of unaffected heterozygous carriers may provide potentially lifesaving premarital counseling and reproductive planning.
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Affiliation(s)
- David J Tester
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota
| | - Hannah M Bombei
- Stead Family Children's Hospital, Division of Pediatric Cardiology, University of Iowa, Iowa City
| | - Kristi K Fitzgerald
- Nemours Cardiac Center, Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | - John R Giudicessi
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota
| | - Beth A Pitel
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota.,Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Erik C Thorland
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota.,Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Barbara G Russell
- Division of Pediatric Cardiology, University of Louisville, Louisville, Kentucky
| | - Samantha K Hamrick
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota
| | - C S John Kim
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota
| | - Carla M Haglund-Turnquist
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota
| | | | - Dianne L Atkins
- Stead Family Children's Hospital, Division of Pediatric Cardiology, University of Iowa, Iowa City
| | - Luis A Ochoa Nunez
- Stead Family Children's Hospital, Division of Pediatric Cardiology, University of Iowa, Iowa City
| | - Ian Law
- Stead Family Children's Hospital, Division of Pediatric Cardiology, University of Iowa, Iowa City
| | - Joel Temple
- Nemours Cardiac Center, Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | - Michael J Ackerman
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.,Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota
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11
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Luo X, Li W, Künzel K, Henze S, Cyganek L, Strano A, Poetsch MS, Schubert M, Guan K. IP3R-Mediated Compensatory Mechanism for Calcium Handling in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes With Cardiac Ryanodine Receptor Deficiency. Front Cell Dev Biol 2020; 8:772. [PMID: 32903370 PMCID: PMC7434870 DOI: 10.3389/fcell.2020.00772] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 07/22/2020] [Indexed: 02/03/2023] Open
Abstract
In adult cardiomyocytes (CMs), the type 2 ryanodine receptor (RYR2) is an indispensable Ca2+ release channel that ensures the integrity of excitation-contraction coupling, which is fundamental for every heartbeat. However, the role and importance of RYR2 during human embryonic cardiac development are still poorly understood. Here, we generated two human induced pluripotent stem cell (iPSC)-based RYR2 knockout (RYR2–/–) lines using the CRISPR/Cas9 gene editing technology. We found that RYR2–/–-iPSCs could differentiate into CMs with the efficiency similar to control-iPSCs (Ctrl-iPSCs); however, the survival of iPSC-CMs was markedly affected by the lack of functional RYR2. While Ctrl-iPSC-CMs exhibited regular Ca2+ handling, we observed significantly reduced frequency and intense abnormalities of Ca2+ transients in RYR2–/–-iPSC-CMs. Ctrl-iPSC-CMs displayed sensitivity to extracellular Ca2+ ([Ca2+ ]o) and caffeine in a concentration-dependent manner, while RYR2–/–-iPSC-CMs showed inconsistent reactions to [Ca2+ ]o and were insensitive to caffeine, indicating there is no RYR2-mediated Ca2+ release from the sarcoplasmic reticulum (SR). Instead, compensatory mechanism for calcium handling in RYR2–/–-iPSC-CMs is partially mediated by the inositol 1,4,5-trisphosphate receptor (IP3R). Similar to Ctrl-iPSC-CMs, SR Ca2+ refilling in RYR2–/–-iPSC-CMs is mediated by SERCA. Additionally, RYR2–/–-iPSC-CMs showed a decreased beating rate and a reduced peak amplitude of L-type Ca2+ current. These findings demonstrate that RYR2 is not required for CM lineage commitment but is important for CM survival and contractile function. IP3R-mediated Ca2+ release is one of the major compensatory mechanisms for Ca2+ cycling in human CMs with the RYR2 deficiency.
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Affiliation(s)
- Xiaojing Luo
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Wener Li
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Karolina Künzel
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Sarah Henze
- Clinic for Cardiology and Pneumology, Universitätsmedizin Göttingen, Göttingen, Germany
| | - Lukas Cyganek
- Clinic for Cardiology and Pneumology, Universitätsmedizin Göttingen, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Anna Strano
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Mareike S Poetsch
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Mario Schubert
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Kaomei Guan
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany.,Clinic for Cardiology and Pneumology, Universitätsmedizin Göttingen, Göttingen, Germany
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12
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Tester DJ, Kim CSJ, Hamrick SK, Ye D, O'Hare BJ, Bombei HM, Fitzgerald KK, Haglund-Turnquist CM, Atkins DL, Nunez LAO, Law I, Temple J, Ackerman MJ. Molecular characterization of the calcium release channel deficiency syndrome. JCI Insight 2020; 5:135952. [PMID: 32663189 PMCID: PMC7455073 DOI: 10.1172/jci.insight.135952] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 07/01/2020] [Indexed: 11/26/2022] Open
Abstract
We identified a potentially novel homozygous duplication involving the promoter region and exons 1–4 of the gene encoding type 2 cardiac ryanodine receptor (RYR2) that is responsible for highly penetrant, exertion-related sudden deaths/cardiac arrests in the Amish community without an overt phenotype to suggest RYR2-mediated catecholaminergic polymorphic ventricular tachycardia (CPVT). Homozygous RYR2 duplication (RYR2-DUP) induced pluripotent stem cell cardiomyocytes (iPSC-CMs) were generated from 2 unrelated patients. There was no difference in baseline Ca2+ handling measurements between WT-iPSC-CM and RYR2-DUP-iPSC-CM lines. However, compared with WT-iPSC-CMs, both patient lines demonstrated a dramatic reduction in caffeine-stimulated and isoproterenol-stimulated (ISO-stimulated) Ca2+ transient amplitude, suggesting RyR2 loss of function. There was a greater than 50% reduction in RYR2 transcript/RyR2 protein expression in both patient iPSC-CMs compared with WT. Delayed afterdepolarization was observed in the RYR2-DUP-iPSC-CMs but not in the WT-iPSC-CMs. Compared with WT-iPSC-CMs, there was significantly elevated arrhythmic activity in the RYR2-DUP-iPSC-CMs in response to ISO. Nadolol, propranolol, and flecainide reduced erratic activity by 8.5-fold, 6.8-fold, and 2.4-fold, respectively, from ISO challenge. Unlike the gain-of-function mechanism observed in RYR2-mediated CPVT, the homozygous multiexon duplication precipitated a dramatic reduction in RYR2 transcription and RyR2 protein translation, a loss of function in calcium handling, and a calcium-induced calcium release apparatus that is insensitive to catecholamines and caffeine. Molecular and functional characterization of the calcium release channel deficiency syndrome in patient-specific induced pluripotent stem cell-cardiomyocytes.
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Affiliation(s)
- David J Tester
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics; Division of Heart Rhythm Services, Department of Cardiovascular Medicine; and Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - C S John Kim
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics; Division of Heart Rhythm Services, Department of Cardiovascular Medicine; and Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Samantha K Hamrick
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics; Division of Heart Rhythm Services, Department of Cardiovascular Medicine; and Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Dan Ye
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics; Division of Heart Rhythm Services, Department of Cardiovascular Medicine; and Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Bailey J O'Hare
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics; Division of Heart Rhythm Services, Department of Cardiovascular Medicine; and Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Hannah M Bombei
- Division of Cardiology, University of Iowa Stead Family Children's Hospital, Iowa City, Iowa, USA
| | - Kristi K Fitzgerald
- Nemours Cardiac Center, Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware, USA
| | - Carla M Haglund-Turnquist
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics; Division of Heart Rhythm Services, Department of Cardiovascular Medicine; and Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Dianne L Atkins
- Division of Cardiology, University of Iowa Stead Family Children's Hospital, Iowa City, Iowa, USA
| | - Luis A Ochoa Nunez
- Division of Cardiology, University of Iowa Stead Family Children's Hospital, Iowa City, Iowa, USA
| | - Ian Law
- Division of Cardiology, University of Iowa Stead Family Children's Hospital, Iowa City, Iowa, USA
| | - Joel Temple
- Nemours Cardiac Center, Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware, USA
| | - Michael J Ackerman
- Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics; Division of Heart Rhythm Services, Department of Cardiovascular Medicine; and Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA
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13
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Bezzerides VJ, Prondzynski M, Carrier L, Pu WT. Gene therapy for inherited arrhythmias. Cardiovasc Res 2020; 116:1635-1650. [PMID: 32321160 PMCID: PMC7341167 DOI: 10.1093/cvr/cvaa107] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/13/2020] [Accepted: 04/15/2020] [Indexed: 01/16/2023] Open
Abstract
Inherited arrhythmias are disorders caused by one or more genetic mutations that increase the risk of arrhythmia, which result in life-long risk of sudden death. These mutations either primarily perturb electrophysiological homeostasis (e.g. long QT syndrome and catecholaminergic polymorphic ventricular tachycardia), cause structural disease that is closely associated with severe arrhythmias (e.g. hypertrophic cardiomyopathy), or cause a high propensity for arrhythmia in combination with altered myocardial structure and function (e.g. arrhythmogenic cardiomyopathy). Currently available therapies offer incomplete protection from arrhythmia and fail to alter disease progression. Recent studies suggest that gene therapies may provide potent, molecularly targeted options for at least a subset of inherited arrhythmias. Here, we provide an overview of gene therapy strategies, and review recent studies on gene therapies for catecholaminergic polymorphic ventricular tachycardia and hypertrophic cardiomyopathy caused by MYBPC3 mutations.
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Affiliation(s)
- Vassilios J Bezzerides
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Maksymilian Prondzynski
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Lucie Carrier
- Institute of Experimental and Clinical Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site, Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - William T Pu
- Department of Cardiology, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, USA
- Harvard Stem Cell Institute, 7 Divinity Avenue, Cambridge, MA 02138, USA
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14
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Nozaki Y, Kato Y, Uike K, Yamamura K, Kikuchi M, Yasuda M, Ohno S, Horie M, Murayama T, Kurebayashi N, Horigome H. Co-Phenotype of Left Ventricular Non-Compaction Cardiomyopathy and Atypical Catecholaminergic Polymorphic Ventricular Tachycardia in Association With R169Q, a Ryanodine Receptor Type 2 Missense Mutation. Circ J 2020; 84:226-234. [DOI: 10.1253/circj.cj-19-0720] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yoshihiro Nozaki
- Department of Child Health, Faculty of Medicine, University of Tsukuba
| | - Yoshiaki Kato
- Department of Child Health, Faculty of Medicine, University of Tsukuba
| | - Kiyoshi Uike
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University
| | - Kenichiro Yamamura
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University
| | | | - Maki Yasuda
- Department of Pediatrics, Hitachi General Hospital
| | - Seiko Ohno
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science
| | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science
| | - Takashi Murayama
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine
| | - Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine
| | - Hitoshi Horigome
- Department of Child Health, Faculty of Medicine, University of Tsukuba
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15
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Zhou X, Park KH, Yamazaki D, Lin PH, Nishi M, Ma Z, Qiu L, Murayama T, Zou X, Takeshima H, Zhou J, Ma J. TRIC-A Channel Maintains Store Calcium Handling by Interacting With Type 2 Ryanodine Receptor in Cardiac Muscle. Circ Res 2019; 126:417-435. [PMID: 31805819 DOI: 10.1161/circresaha.119.316241] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
RATIONALE Trimeric intracellular cation (TRIC)-A and B are distributed to endoplasmic reticulum/sarcoplasmic reticulum intracellular Ca2+ stores. The crystal structure of TRIC has been determined, confirming the homotrimeric structure of a potassium channel. While the pore architectures of TRIC-A and TRIC-B are conserved, the carboxyl-terminal tail (CTT) domains of TRIC-A and TRIC-B are different from each other. Aside from its recognized role as a counterion channel that participates in excitation-contraction coupling of striated muscles, the physiological function of TRIC-A in heart physiology and disease has remained largely unexplored. OBJECTIVE In cardiomyocytes, spontaneous Ca2+ waves, triggered by store overload-induced Ca2+ release mediated by the RyR2 (type 2 ryanodine receptor), develop extrasystolic contractions often associated with arrhythmic events. Here, we test the hypothesis that TRIC-A is a physiological component of RyR2-mediated Ca2+ release machinery that directly modulates store overload-induced Ca2+ release activity via CTT. METHODS AND RESULTS We show that cardiomyocytes derived from the TRIC-A-/- (TRIC-A knockout) mice display dysregulated Ca2+ movement across sarcoplasmic reticulum. Biochemical studies demonstrate a direct interaction between CTT-A and RyR2. Modeling and docking studies reveal potential sites on RyR2 that show differential interactions with CTT-A and CTT-B. In HEK293 (human embryonic kidney) cells with stable expression of RyR2, transient expression of TRIC-A, but not TRIC-B, leads to apparent suppression of spontaneous Ca2+ oscillations. Ca2+ measurements using the cytosolic indicator Fura-2 and the endoplasmic reticulum luminal store indicator D1ER suggest that TRIC-A enhances Ca2+ leak across the endoplasmic reticulum by directly targeting RyR2 to modulate store overload-induced Ca2+ release. Moreover, synthetic CTT-A peptide facilitates RyR2 activity in lipid bilayer reconstitution system, enhances Ca2+ sparks in permeabilized TRIC-A-/- cardiomyocytes, and induces intracellular Ca2+ release after microinjection into isolated cardiomyocytes, whereas such effects were not observed with the CTT-B peptide. In response to isoproterenol stimulation, the TRIC-A-/- mice display irregular ECG and develop more fibrosis than the WT (wild type) littermates. CONCLUSIONS In addition to the ion-conducting function, TRIC-A functions as an accessory protein of RyR2 to modulate sarcoplasmic reticulum Ca2+ handling in cardiac muscle.
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Affiliation(s)
- Xinyu Zhou
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| | - Ki Ho Park
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| | - Daiju Yamazaki
- Department of Biological Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Japan (D.Y., M.N., H.T.)
| | - Pei-Hui Lin
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| | - Miyuki Nishi
- Department of Biological Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Japan (D.Y., M.N., H.T.)
| | - Zhiwei Ma
- Department of Physics and Astronomy, Dalton Cardiovascular Research Center (Z.M., L.Q., X. Zou), University of Missouri, Columbia.,Department of Biochemistry (Z.M., L.Q., X. Zou), University of Missouri, Columbia
| | - Liming Qiu
- Department of Physics and Astronomy, Dalton Cardiovascular Research Center (Z.M., L.Q., X. Zou), University of Missouri, Columbia.,Department of Biochemistry (Z.M., L.Q., X. Zou), University of Missouri, Columbia
| | - Takashi Murayama
- Department of Pharmacology, Juntendo University School of Medicine, Tokyo, Japan (T.M.)
| | - Xiaoqin Zou
- Department of Physics and Astronomy, Dalton Cardiovascular Research Center (Z.M., L.Q., X. Zou), University of Missouri, Columbia.,Department of Biochemistry (Z.M., L.Q., X. Zou), University of Missouri, Columbia
| | - Hiroshi Takeshima
- Department of Biological Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Japan (D.Y., M.N., H.T.)
| | - Jingsong Zhou
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington (J.Z.)
| | - Jianjie Ma
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
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16
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Kohli U, Aziz Z, Beaser AD, Nayak HM. A large deletion in
RYR2
exon 3 is associated with nadolol and flecainide refractory catecholaminergic polymorphic ventricular tachycardia. Pacing Clin Electrophysiol 2019; 42:1146-1154. [DOI: 10.1111/pace.13668] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 03/19/2019] [Accepted: 03/20/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Utkarsh Kohli
- Division of Pediatric Cardiology, Department of PediatricsPritzker School of Medicine of the University of ChicagoChicago Illinois
| | - Zaid Aziz
- Center for Arrhythmia Care, Heart & Vascular CenterPritzker School of Medicine of the University of Chicago Chicago Illinois
| | - Andrew D. Beaser
- Center for Arrhythmia Care, Heart & Vascular CenterPritzker School of Medicine of the University of Chicago Chicago Illinois
| | - Hemal M. Nayak
- Center for Arrhythmia Care, Heart & Vascular CenterPritzker School of Medicine of the University of Chicago Chicago Illinois
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17
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Hylind RJ, Chandler SF, Skinner JR, Abrams DJ. Genetic Testing for Inherited Cardiac Arrhythmias: Current State-of-the-Art and Future Avenues. J Innov Card Rhythm Manag 2018; 9:3406-3416. [PMID: 32494476 PMCID: PMC7252877 DOI: 10.19102/icrm.2018.091102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 03/14/2018] [Indexed: 12/24/2022] Open
Abstract
The seminal discovery that sequence variation in genes encoding cardiac ion channels was behind the inherited cardiac arrhythmic syndromes has led to major advances in understanding the functional biological mechanisms of cardiomyocyte depolarization and repolarization. The cost and speed with which these genes can now be sequenced have allowed for genetic testing to become a major component of clinical care and have led to important ramifications, yet interpretation of specific variants needs to be performed within the context of the clinical findings in the proband and extended family. As technology continues to advance, the promise of therapeutic manipulation of certain genetic pathways grows ever more real.
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Affiliation(s)
- Robyn J. Hylind
- Inherited Cardiac Arrhythmia Program, Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Stephanie F. Chandler
- Inherited Cardiac Arrhythmia Program, Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Jonathan R. Skinner
- Green Lane Paediatric and Congenital Cardiac Services, Starship Children’s Hospital, Auckland, New Zealand
- Department of Paediatrics, Child and Youth Health, The University of Auckland, Auckland, New Zealand
| | - Dominic J. Abrams
- Inherited Cardiac Arrhythmia Program, Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
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18
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Reduced expression of cardiac ryanodine receptor protects against stress-induced ventricular tachyarrhythmia, but increases the susceptibility to cardiac alternans. Biochem J 2018; 475:169-183. [PMID: 29170159 DOI: 10.1042/bcj20170631] [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: 08/10/2017] [Revised: 11/08/2017] [Accepted: 11/22/2017] [Indexed: 01/30/2023]
Abstract
Reduced protein expression of the cardiac ryanodine receptor type 2 (RyR2) is thought to affect the susceptibility to stress-induced ventricular tachyarrhythmia (VT) and cardiac alternans, but direct evidence for the role of RyR2 protein expression in VT and cardiac alternans is lacking. Here, we used a mouse model (crrm1) that expresses a reduced level of the RyR2 protein to determine the impact of reduced RyR2 protein expression on the susceptibility to VT, cardiac alternans, cardiac hypertrophy, and sudden death. Electrocardiographic analysis revealed that after the injection of relatively high doses of caffeine and epinephrine (agents commonly used for stress test), wild-type (WT) mice displayed long-lasting VTs, whereas the crrm1 mutant mice exhibited no VTs at all, indicating that the crrm1 mutant mice are resistant to stress-induced VTs. Intact heart Ca2+ imaging and action potential (AP) recordings showed that the crrm1 mutant mice are more susceptible to fast-pacing induced Ca2+ alternans and AP duration alternans compared with WT mice. The crrm1 mutant mice also showed an increased heart-to-body-weight ratio and incidence of sudden death at young ages. Furthermore, the crrm1 mutant hearts displayed altered Ca2+ transients with increased time-to-peak and decay time (T50), increased ventricular wall thickness and ventricular cell area compared with WT hearts. These results indicate that reduced RyR2 protein expression suppresses stress-induced VTs, but enhances the susceptibility to cardiac alternans, hypertrophy, and sudden death.
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19
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Fischer E, Gottschalk A, Schüler C. An optogenetic arrhythmia model to study catecholaminergic polymorphic ventricular tachycardia mutations. Sci Rep 2017; 7:17514. [PMID: 29235522 PMCID: PMC5727474 DOI: 10.1038/s41598-017-17819-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/01/2017] [Indexed: 11/08/2022] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a condition of abnormal heart rhythm (arrhythmia), induced by physical activity or stress. Mutations in ryanodine receptor 2 (RyR2), a Ca2+ release channel located in the sarcoplasmic reticulum (SR), or calsequestrin 2 (CASQ2), a SR Ca2+ binding protein, are linked to CPVT. For specific drug development and to study distinct arrhythmias, simple models are required to implement and analyze such mutations. Here, we introduced CPVT inducing mutations into the pharynx of Caenorhabditis elegans, which we previously established as an optogenetically paced heart model. By electrophysiology and video-microscopy, we characterized mutations in csq-1 (CASQ2 homologue) and unc-68 (RyR2 homologue). csq-1 deletion impaired pharynx function and caused missed pumps during 3.7 Hz pacing. Deletion mutants of unc-68, and in particular the point mutant UNC-68(R4743C), analogous to the established human CPVT mutant RyR2(R4497C), were unable to follow 3.7 Hz pacing, with progressive defects during long stimulus trains. The pharynx either locked in pumping at half the pacing frequency or stopped pumping altogether, possibly due to UNC-68 leakiness and/or malfunctional SR Ca2+ homeostasis. Last, we could reverse this 'worm arrhythmia' by the benzothiazepine S107, establishing the nematode pharynx for studying specific CPVT mutations and for drug screening.
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Affiliation(s)
- Elisabeth Fischer
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany
- University of Edinburgh, Centre for Integrative Physiology, Hugh Robson Building, George Square, Edinburgh, EH8 9XE, UK
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany.
- Institute of Biophysical Chemistry, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany.
- Cluster of Excellence Frankfurt - Macromolecular Complexes, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany.
| | - Christina Schüler
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany.
- Institute of Biophysical Chemistry, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany.
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20
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Choy L, Yeo JM, Tse V, Chan SP, Tse G. Cardiac disease and arrhythmogenesis: Mechanistic insights from mouse models. IJC HEART & VASCULATURE 2016; 12:1-10. [PMID: 27766308 PMCID: PMC5064289 DOI: 10.1016/j.ijcha.2016.05.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 05/02/2016] [Indexed: 12/19/2022]
Abstract
The mouse is the second mammalian species, after the human, in which substantial amount of the genomic information has been analyzed. With advances in transgenic technology, mutagenesis is now much easier to carry out in mice. Consequently, an increasing number of transgenic mouse systems have been generated for the study of cardiac arrhythmias in ion channelopathies and cardiomyopathies. Mouse hearts are also amenable to physical manipulation such as coronary artery ligation and transverse aortic constriction to induce heart failure, radiofrequency ablation of the AV node to model complete AV block and even implantation of a miniature pacemaker to induce cardiac dyssynchrony. Last but not least, pharmacological models, despite being simplistic, have enabled us to understand the physiological mechanisms of arrhythmias and evaluate the anti-arrhythmic properties of experimental agents, such as gap junction modulators, that may be exert therapeutic effects in other cardiac diseases. In this article, we examine these in turn, demonstrating that primary inherited arrhythmic syndromes are now recognized to be more complex than abnormality in a particular ion channel, involving alterations in gene expression and structural remodelling. Conversely, in cardiomyopathies and heart failure, mutations in ion channels and proteins have been identified as underlying causes, and electrophysiological remodelling are recognized pathological features. Transgenic techniques causing mutagenesis in mice are extremely powerful in dissecting the relative contributions of different genes play in producing disease phenotypes. Mouse models can serve as useful systems in which to explore how protein defects contribute to arrhythmias and direct future therapy.
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Affiliation(s)
- Lois Choy
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Jie Ming Yeo
- School of Medicine, Imperial College London, SW7 2AZ, UK
| | - Vivian Tse
- Department of Physiology, McGill University, Canada
| | - Shing Po Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Gary Tse
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
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21
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A knock-in mouse model of N-terminal R420W mutation of cardiac ryanodine receptor exhibits arrhythmogenesis with abnormal calcium dynamics in cardiomyocytes. Biochem Biophys Res Commun 2014; 452:665-8. [DOI: 10.1016/j.bbrc.2014.08.132] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 08/25/2014] [Indexed: 11/22/2022]
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