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Henriquez E, Hernandez EA, Mundla SR, Wankhade DH, Saad M, Ketha SS, Penke Y, Martinez GC, Ahmed FS, Hussain MS. Catecholaminergic Polymorphic Ventricular Tachycardia and Gene Therapy: A Comprehensive Review of the Literature. Cureus 2023; 15:e47974. [PMID: 38034271 PMCID: PMC10686237 DOI: 10.7759/cureus.47974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited channelopathy. In this review, we summarize the epidemiology, pathophysiology, clinical characteristics, diagnostics, genetic mutations, standard treatment, and the emergence of potential gene therapy. This inherited cardiac arrhythmia presents in a bimodal distribution with no association between sex or ethnicity. Six different CPVT genes have been identified, however, most of the cases are related to a heterozygous, gain-of-function mutation on the ryanodine receptor-2 gene (RyR2) and calsequestrin-2 gene (CASQ2) that causes delayed after-depolarization. The diagnosis is clinically based, seen in patients presenting with syncope after exercise or stress-related emotions, as well as cardiac arrest with full recovery or even sudden cardiac death. Standard treatment relies on beta-blockers, with add-on therapy, flecainide, and cardiac sympathetic denervation as second-line treatments. An implantable cardioverter-defibrillator is indicated for patients who have suffered a cardiac arrest. Potential gene therapy has emerged in the last 20 years and accelerated because of associated viral vector application in increasing the efficiency of prolonged cardiac gene expression. Nevertheless, human trials for gene therapy for CPVT have been limited as the population is rare, and an excessive amount of funding is required.
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Affiliation(s)
- Elvis Henriquez
- Miscellaneous, Facultad de Medicina, Universidad de Ciencias Medicas, Las Tunas, CUB
| | - Edwin A Hernandez
- Miscellaneous, Faculty of Medicine, Universidad de El Salvador, San Salvador, SLV
| | - Sravya R Mundla
- Internal Medicine, Apollo Institute of Medical Sciences and Research, Hyderabad, IND
| | | | - Muhammad Saad
- Internal Medicine, Fatima Memorial College (FMH) of Medicine and Dentistry, Lahore, PAK
| | - Sagar S Ketha
- Internal Medicine, Government Medical College, Srikakulam, IND
| | - Yasaswini Penke
- Internal Medicine, Government Medical College, Srikakulam, IND
| | - Gabriela C Martinez
- Internal Medicine, Faculty of Medicine, Universidad Nacional Autonoma de Honduras, San Pedro Sula, HND
| | - Faiza S Ahmed
- Internal Medicine, Advocate Lutheran General Hospital, Park Ridge, USA
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Kurzlechner LM, Kishnani S, Chowdhury S, Atkins SL, Moya-Mendez ME, Parker LE, Rosamilia MB, Tadros HJ, Pace LA, Patel V, Chahal CAA, Landstrom AP. DiscoVari: A Web-Based Precision Medicine Tool for Predicting Variant Pathogenicity in Cardiomyopathy- and Channelopathy-Associated Genes. Circ Genom Precis Med 2023; 16:317-327. [PMID: 37409478 PMCID: PMC10527712 DOI: 10.1161/circgen.122.003911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 05/30/2023] [Indexed: 07/07/2023]
Abstract
BACKGROUND With genetic testing advancements, the burden of incidentally identified cardiac disease-associated gene variants is rising. These variants may carry a risk of sudden cardiac death, highlighting the need for accurate diagnostic interpretation. We sought to identify pathogenic hotspots in sudden cardiac death-associated genes using amino acid-level signal-to-noise (S:N) analysis and develop a web-based precision medicine tool, DiscoVari, to improve variant evaluation. METHODS The minor allele frequency of putatively pathogenic variants was derived from cohort-based cardiomyopathy and channelopathy studies in the literature. We normalized disease-associated minor allele frequencies to rare variants in an ostensibly healthy population (Genome Aggregation Database) to calculate amino acid-level S:N. Amino acids with S:N above the gene-specific threshold were defined as hotspots. DiscoVari was built using JavaScript ES6 and using open-source JavaScript library ReactJS, web development framework Next.js, and JavaScript runtime NodeJS. We validated the ability of DiscoVari to identify pathogenic variants using variants from ClinVar and individuals clinically evaluated at the Duke University Hospitals with cardiac genetic testing. RESULTS We developed DiscoVari as an internet-based tool for S:N-based variant hotspots. Upon validation, a higher proportion of ClinVar likely pathogenic/pathogenic variants localized to DiscoVari hotspots (43.1%) than likely benign/benign variants (17.8%; P<0.0001). Further, 75.3% of ClinVar variants reclassified to likely pathogenic/pathogenic were in hotspots, compared with 41.3% of those reclassified as variants of uncertain significance (P<0.0001) and 23.4% of those reclassified as likely benign/benign (P<0.0001). Of the clinical cohort variants, 73.1% of likely pathogenic/pathogenic were in hotspots, compared with 0.0% of likely benign/benign (P<0.01). CONCLUSIONS DiscoVari reliably identifies disease-susceptible amino acid residues to evaluate variants by searching amino acid-specific S:N ratios.
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Affiliation(s)
| | - Sujata Kishnani
- Dept of Pediatrics, Division of Pediatric Cardiology, Durham, NC
| | - Shawon Chowdhury
- Dept of Pediatrics, Division of Pediatric Cardiology, Durham, NC
| | - Sage L. Atkins
- Dept of Pediatrics, Division of Pediatric Cardiology, Durham, NC
| | | | - Lauren E. Parker
- Dept of Pediatrics, Division of Pediatric Cardiology, Durham, NC
| | | | - Hanna J. Tadros
- Dept of Pediatrics, Section of Pediatric Cardiology, Baylor College of Medicine, Houston, TX
| | - Leslie A. Pace
- Dept of Pediatrics, Division of Pediatric Cardiology, Durham, NC
| | - Viraj Patel
- North West Thames Regional Genetics Service, St Mark’s Hospital, London, United Kingdom
| | - C. Anwar A. Chahal
- Center for Inherited Cardiovascular Diseases, WellSpan Health, Lancaster, PA
- Barts Heart Centre, St Bartholomew’s Hospital, Barts Health NHS Trust, London, United Kingdom
- Cardiac Electrophysiology, Cardiovascular Division, Hospital of the Univ of Pennsylvania, Philadelphia, PA
- Dept of Cardiovascular Medicine, Mayo Clinic, Rochester, MN
| | - Andrew P. Landstrom
- Dept of Pediatrics, Division of Pediatric Cardiology, Durham, NC
- Dept of Cell Biology, Duke Univ School of Medicine, Durham, NC
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Wei J, Guo W, Wang R, Paul Estillore J, Belke D, Chen YX, Vallmitjana A, Benitez R, Hove-Madsen L, Chen SRW. RyR2 Serine-2030 PKA Site Governs Ca 2+ Release Termination and Ca 2+ Alternans. Circ Res 2023; 132:e59-e77. [PMID: 36583384 DOI: 10.1161/circresaha.122.321177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND PKA (protein kinase A)-mediated phosphorylation of cardiac RyR2 (ryanodine receptor 2) has been extensively studied for decades, but the physiological significance of PKA phosphorylation of RyR2 remains poorly understood. Recent determination of high-resolution 3-dimensional structure of RyR2 in complex with CaM (calmodulin) reveals that the major PKA phosphorylation site in RyR2, serine-2030 (S2030), is located within a structural pathway of CaM-dependent inactivation of RyR2. This novel structural insight points to a possible role of PKA phosphorylation of RyR2 in CaM-dependent inactivation of RyR2, which underlies the termination of Ca2+ release and induction of cardiac Ca2+ alternans. METHODS We performed single-cell endoplasmic reticulum Ca2+ imaging to assess the impact of S2030 mutations on Ca2+ release termination in human embryonic kidney 293 cells. Here we determined the role of the PKA site RyR2-S2030 in a physiological setting, we generated a novel mouse model harboring the S2030L mutation and carried out confocal Ca2+ imaging. RESULTS We found that mutations, S2030D, S2030G, S2030L, S2030V, and S2030W reduced the endoplasmic reticulum luminal Ca2+ level at which Ca2+ release terminates (the termination threshold), whereas S2030P and S2030R increased the termination threshold. S2030A and S2030T had no significant impact on release termination. Furthermore, CaM-wild-type increased, whereas Ca2+ binding deficient CaM mutant (CaM-M [a loss-of-function CaM mutation with all 4 EF-hand motifs mutated]), PKA, and Ca2+/CaMKII (CaM-dependent protein kinase II) reduced the termination threshold. The S2030L mutation abolished the actions of CaM-wild-type, CaM-M, and PKA, but not CaMKII, in Ca2+ release termination. Moreover, we showed that isoproterenol and CaM-M suppressed pacing-induced Ca2+ alternans and accelerated Ca2+ transient recovery in intact working hearts, whereas CaM-wild-type exerted an opposite effect. The impact of isoproterenol was partially and fully reversed by the PKA inhibitor N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide and the CaMKII inhibitor N-[2-[N-(4-chlorocinnamyl)-N-methylaminomethyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide individually and together, respectively. S2030L abolished the impact of CaM-wild-type, CaM-M, and N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide-sensitive component, but not the N-[2-[N-(4-chlorocinnamyl)-N-methylaminomethyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide-sensitive component, of isoproterenol.
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Affiliation(s)
- Jinhong Wei
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.).,School of Medicine, Northwest University, Xi 'an, China (J.W.)
| | - Wenting Guo
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - John Paul Estillore
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - Darrell Belke
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - Yong-Xiang Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | | | - Raul Benitez
- Department of Automatic Control, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain (A.V., R.B.)
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona IIBB-CSIC, IIB Sant Pau and CIBERCV, Hospital de Sant Pau, 08025, Barcelona, Spain (L.H.-M.)
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
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Li S, Lv T, Yang J, Li K, Yang Y, Zhang P. A gain of function ryanodine receptor 2 mutation (R1760W-RyR2) in catecholaminergic polymorphic ventricular tachycardia. Clin Exp Pharmacol Physiol 2023; 50:39-49. [PMID: 36082968 DOI: 10.1111/1440-1681.13722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/28/2022] [Accepted: 09/07/2022] [Indexed: 12/13/2022]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome associated with Ca2+ leak predominantly caused by ryanodine receptor 2 (RyR2) mutations. We identified a R1760W-RyR2 mutation located between the N-terminal domain and the central domain of RyR2 in a CPVT patient by DNA sequencing. Recombinant mutant RyR2-2801mcherry plasmid generated by the overlap extension polymerase chain reaction and seamless cloning was transfected in HEK293 cells for the cell model. Single-cell luminal and cytosolic Ca2+ imaging was measured by endoplasmic reticulum (ER) luminal Ca2+ -sensitive protein D1ER and Fura-2 AM on a confocal laser scanning microscope, respectively. We found that in RyR2 mutant cells, the propensity for store-overload-induced Ca2+ release (SOICR) was enhanced representing increased Ca2+ oscillations, reduced activation and termination thresholds of spontaneous Ca2+ release; and the sensitivity to cytosolic Ca2+ activation was increased manifesting reduced steady state ER Ca2+ levels. Our results indicated that R1760W-RyR2 mutation induced calcium leak, representing a gain of function. Further, antiarrhythmic drugs propafenone and flecainide significantly suppressed SOICR caused by the R1760W-RyR2 mutation at a concentration of 20 μM, which was lower than the concentration at which carvedilol suppressed SOICR.
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Affiliation(s)
- Siyuan Li
- Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
| | - Tingting Lv
- Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
| | - Jing Yang
- Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
| | - Kun Li
- Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
| | - Ying Yang
- Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
| | - Ping Zhang
- Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
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Fowler ED, Zissimopoulos S. Molecular, Subcellular, and Arrhythmogenic Mechanisms in Genetic RyR2 Disease. Biomolecules 2022; 12:1030. [PMID: 35892340 DOI: 10.3390/biom12081030] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/22/2022] [Accepted: 07/24/2022] [Indexed: 11/17/2022] Open
Abstract
The ryanodine receptor (RyR2) has a critical role in controlling Ca2+ release from the sarcoplasmic reticulum (SR) throughout the cardiac cycle. RyR2 protein has multiple functional domains with specific roles, and four of these RyR2 protomers are required to form the quaternary structure that comprises the functional channel. Numerous mutations in the gene encoding RyR2 protein have been identified and many are linked to a wide spectrum of arrhythmic heart disease. Gain of function mutations (GoF) result in a hyperactive channel that causes excessive spontaneous SR Ca2+ release. This is the predominant cause of the inherited syndrome catecholaminergic polymorphic ventricular tachycardia (CPVT). Recently, rare hypoactive loss of function (LoF) mutations have been identified that produce atypical effects on cardiac Ca2+ handling that has been termed calcium release deficiency syndrome (CRDS). Aberrant Ca2+ release resulting from both GoF and LoF mutations can result in arrhythmias through the Na+/Ca2+ exchange mechanism. This mini-review discusses recent findings regarding the role of RyR2 domains and endogenous regulators that influence RyR2 gating normally and with GoF/LoF mutations. The arrhythmogenic consequences of GoF/LoF mutations will then be discussed at the macromolecular and cellular level.
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Kurebayashi N, Murayama T, Ota R, Suzuki J, Kanemaru K, Kobayashi T, Ohno S, Horie M, Iino M, Yamashita F, Sakurai T. Cytosolic Ca2+-dependent Ca2+ release activity primarily determines the ER Ca2+ level in cells expressing the CPVT-linked mutant RYR2. J Gen Physiol 2022; 154:213175. [PMID: 35446340 PMCID: PMC9037340 DOI: 10.1085/jgp.202112869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 11/28/2021] [Accepted: 04/04/2022] [Indexed: 12/16/2022] Open
Abstract
Type 2 ryanodine receptor (RYR2) is a cardiac Ca2+ release channel in the ER. Mutations in RYR2 are linked to catecholaminergic polymorphic ventricular tachycardia (CPVT). CPVT is associated with enhanced spontaneous Ca2+ release, which tends to occur when [Ca2+]ER reaches a threshold. Mutations lower the threshold [Ca2+]ER by increasing luminal Ca2+ sensitivity or enhancing cytosolic [Ca2+] ([Ca2+]cyt)-dependent activity. Here, to establish the mechanism relating the change in [Ca2+]cyt-dependent activity of RYR2 and the threshold [Ca2+]ER, we carried out cell-based experiments and in silico simulations. We expressed WT and CPVT-linked mutant RYR2s in HEK293 cells and measured [Ca2+]cyt and [Ca2+]ER using fluorescent Ca2+ indicators. CPVT RYR2 cells showed higher oscillation frequency and lower threshold [Ca2+]ER than WT cells. The [Ca2+]cyt-dependent activity at resting [Ca2+]cyt, Arest, was greater in CPVT mutants than in WT, and we found an inverse correlation between threshold [Ca2+]ER and Arest. In addition, lowering RYR2 expression increased the threshold [Ca2+]ER and a product of Arest, and the relative expression level for each mutant correlated with threshold [Ca2+]ER, suggesting that the threshold [Ca2+]ER depends on the net Ca2+ release rate via RYR2. Modeling reproduced Ca2+ oscillations with [Ca2+]cyt and [Ca2+]ER changes in WT and CPVT cells. Interestingly, the [Ca2+]cyt-dependent activity of specific mutations correlated with the age of disease onset in patients carrying them. Our data suggest that the reduction in threshold [Ca2+]ER for spontaneous Ca2+ release by CPVT mutation is explained by enhanced [Ca2+]cyt-dependent activity without requiring modulation of the [Ca2+]ER sensitivity of RYR2.
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Affiliation(s)
- Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan,Correspondence to Nagomi Kurebayashi:
| | - Takashi Murayama
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Ryosaku Ota
- Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Junji Suzuki
- Department of Physiology, University of California San Francisco, San Francisco, CA
| | - Kazunori Kanemaru
- Department of Physiology, Nihon University School of Medicine, Tokyo, Japan
| | - Takuya Kobayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Seiko Ohno
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Minoru Horie
- Department of Cardiovascular Medicine, Shiga University of Medical Science, Shiga, Japan
| | - Masamitsu Iino
- Department of Physiology, Nihon University School of Medicine, Tokyo, Japan
| | - Fumiyoshi Yamashita
- Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan,Fumiyoshi Yamashita:
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
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Cimarosti B, Canac R, De Waard S, Girardeau A, Gaignerie A, Derevier A, Forest V, Ronjat M, Le Marec H, Gourraud JB, Lemarchand P, De Waard M, Lamirault G, Gaborit N. Generation of human induced pluripotent stem cell lines from three patients affected by Catecholaminergic Polymorphic ventricular tachycardia (CPVT) carrying heterozygous mutations in RYR2 gene. Stem Cell Res 2022; 60:102688. [DOI: 10.1016/j.scr.2022.102688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/18/2022] [Accepted: 01/23/2022] [Indexed: 10/19/2022] Open
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Wilson AD, Hu J, Sigalas C, Venturi E, Valdivia HH, Valdivia CR, Lei M, Musgaard M, Sitsapesan R. The V2475F CPVT1 mutation yields distinct RyR2 channel populations that differ in their responses to cytosolic Ca 2+ and Mg 2. J Physiol 2021; 599:5179-5201. [PMID: 34676560 DOI: 10.1113/jp281707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 09/30/2021] [Indexed: 11/08/2022] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1) is a lethal genetic disease causing arrhythmias and sudden cardiac death in children and young adults and is linked to mutations in the cardiac ryanodine receptor (RyR2). The effects of CPVT1 mutations on RyR2 ion-channel function are often investigated using purified recombinant RyR2 channels homozygous for the mutation. However, CPVT1 patients are heterozygous for the disease, so this approach does not reveal the true changes to RyR2 function across the entire RyR2 population of channels in the heart. We therefore investigated the native cardiac RyR2 single-channel abnormalities in mice heterozygous for the CPVT1 mutation, V2475F(+/-)-RyR2, and applied molecular modelling techniques to investigate the possible structural changes that could initiate any altered function. We observed that increased sensitivity of cardiac V2475F(+/-)-RyR2 channels to both activating and inactivating levels of cytosolic Ca2+ , plus attenuation of Mg2+ inhibition, were the most marked changes. Severity of abnormality was not uniform across all channels, giving rise to multiple sub-populations with differing functional characteristics. For example, 46% of V2475F(+/-)-RyR2 channels exhibited reduced Mg2+ inhibition and 23% were actually activated by Mg2+ . Using homology modelling, we discovered that V2475 is situated at a hinge between two regions of the RyR2 helical domain 1 (HD1). Our model proposes that detrimental functional changes to RyR2 arise because mutation at this critical site reduces the angle between these regions. Our results demonstrate the necessity of characterising the total heterozygous population of CPVT1-mutated channels in order to understand CPVT1 phenotypes in patients. KEY POINTS: RyR2 mutations can cause type-1 catecholaminergic polymorphic ventricular tachycardia (CPVT1), a lethal, autosomal-dominant arrhythmic disease. However, the changes in RyR2 ion-channel function that result from the many different patient mutations are rarely investigated in detail and often only recombinant RyR2, homozygous for the mutation, is studied. As CPVT1 is a heterozygous disease and the tetrameric RyR2 channels expressed in the heart will contain varying numbers of mutated monomers, we have investigated the range of RyR2 single-channel abnormalities found in the hearts of mice heterozygous for the CPVT1 mutation, V2475F(+/-)-RyR2. Specific alterations to ligand regulation of V2475F(+/-)-RyR2 were observed. Multiple sub-populations of channels exhibited varying degrees of abnormality. In particular, an increased sensitivity to activating and inactivating cytosolic [Ca2+ ], and reduced sensitivity to Mg2+ inhibition were evident. Our results provide mechanistic insight into the changes to RyR2 gating that destabilise sarcoplasmic reticulum Ca2+ -release causing life-threatening arrhythmias in V2475F(+/-)-CPVT1 patients.
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Affiliation(s)
| | - Jianshu Hu
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | - Elisa Venturi
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Héctor H Valdivia
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Carmen R Valdivia
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin School of Medicine and Public Health, Madison, USA
| | - Ming Lei
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Maria Musgaard
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
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Ng YH, Okolo CA, Erickson JR, Baldi JC, Jones PP. Protein O-GlcNAcylation in the heart. Acta Physiol (Oxf) 2021; 233:e13696. [PMID: 34057811 DOI: 10.1111/apha.13696] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/25/2021] [Accepted: 05/27/2021] [Indexed: 12/30/2022]
Abstract
O-GlcNAcylation is a ubiquitous post-translational modification that is extremely labile and plays a significant role in physiology, including the heart. Sustained activation of cardiac O-GlcNAcylation is frequently associated with alterations in cellular metabolism, leading to detrimental effects on cardiovascular function. This is particularly true during conditions such as diabetes, hypertension, cardiac remodelling, heart failure and arrhythmogenesis. Paradoxically, transient elevation of cardiac protein O-GlcNAcylation can also exert beneficial effects in the heart. There is compelling evidence to suggest that a complex interaction between O-GlcNAcylation and phosphorylation also exists in the heart. Beyond direct functional consequences on cardiomyocytes, O-GlcNAcylation also acts indirectly by altering the function of transcription factors that affect downstream signalling. This review focuses on the potential cardioprotective role of protein O-GlcNAcylation during ischaemia-reperfusion injury, the deleterious consequences of chronically elevated O-GlcNAc levels, the interplay between O-GlcNAcylation and phosphorylation in the cardiomyocytes and the effects of O-GlcNAcylation on other major non-myocyte cell types in the heart.
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Affiliation(s)
- Yann Huey Ng
- Department of Medicine and HeartOtago University of Otago Dunedin New Zealand
| | - Chidinma A. Okolo
- Department of Physiology and HeartOtago University of Otago Dunedin New Zealand
- Life Sciences Division Diamond Light Source LtdHarwell Science and Innovation Campus Didcot UK
| | - Jeffrey R. Erickson
- Department of Physiology and HeartOtago University of Otago Dunedin New Zealand
| | - James C. Baldi
- Department of Medicine and HeartOtago University of Otago Dunedin New Zealand
| | - Peter P. Jones
- Department of Physiology and HeartOtago University of Otago Dunedin New Zealand
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Sadredini M, Haugsten Hansen M, Frisk M, Louch WE, Lehnart SE, Sjaastad I, Stokke MK. CaMKII inhibition has dual effects on spontaneous Ca 2+ release and Ca 2+ alternans in ventricular cardiomyocytes from mice with a gain-of-function RyR2 mutation. Am J Physiol Heart Circ Physiol 2021; 321:H446-H460. [PMID: 34270372 DOI: 10.1152/ajpheart.00011.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In conditions with abnormally increased activity of the cardiac ryanodine receptor (RyR2), Ca2+/calmodulin-dependent protein kinase II (CaMKII) can contribute to a further destabilization of RyR2 that results in triggered arrhythmias. Therefore, inhibition of CaMKII in such conditions has been suggested as a strategy to suppress RyR2 activity and arrhythmias. However, suppression of RyR2 activity can lead to the development of arrhythmogenic Ca2+ alternans. The aim of this study was to test whether the suppression of RyR2 activity caused by inhibition of CaMKII increases propensity for Ca2+ alternans. We studied spontaneous Ca2+ release events and Ca2+ alternans in isolated left ventricular cardiomyocytes from mice carrying the gain-of-function RyR2 mutation RyR2-R2474S and from wild-type mice. CaMKII inhibition by KN-93 effectively decreased the frequency of spontaneous Ca2+ release events in RyR2-R2474S cardiomyocytes exposed to the β-adrenoceptor agonist isoprenaline. However, KN-93-treated RyR2-R2474S cardiomyocytes also showed increased propensity for Ca2+ alternans and increased Ca2+ alternans ratio compared with both an inactive analog of KN-93 and with vehicle-treated controls. This increased propensity for Ca2+ alternans was explained by prolongation of Ca2+ release refractoriness. Importantly, the increased propensity for Ca2+ alternans in KN-93-treated RyR2-R2474S cardiomyocytes did not surpass that of wild type. In conclusion, inhibition of CaMKII efficiently reduces spontaneous Ca2+ release but promotes Ca2+ alternans in RyR2-R2474S cardiomyocytes with a gain-of-function RyR2 mutation. The dominant effect in RyR2-R2474S is to reduce spontaneous Ca2+ release, which supports this intervention as a therapeutic strategy in this specific condition. However, future studies on CaMKII inhibition in conditions with increased propensity for Ca2+ alternans should include investigation of both phenomena.NEW & NOTEWORTHY Genetically increased RyR2 activity promotes arrhythmogenic Ca2+ release. Inhibition of CaMKII suppresses RyR2 activity and arrhythmogenic Ca2+ release. Suppression of RyR2 activity prolongs refractoriness of Ca2+ release. Prolonged refractoriness of Ca2+ release leads to arrhythmogenic Ca2+ alternans. CaMKII inhibition promotes Ca2+ alternans by prolonging Ca2+ release refractoriness.
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Affiliation(s)
- Mani Sadredini
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway
| | - Marie Haugsten Hansen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway
| | - Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway
| | - Stephan E Lehnart
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), Göttingen, Germany
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway
| | - Mathis Korseberg Stokke
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Cardiac Research Centre, University of Oslo, Oslo, Norway.,Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
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11
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Guo W, Wei J, Estillore JP, Zhang L, Wang R, Sun B, Chen SRW. RyR2 disease mutations at the C-terminal domain intersubunit interface alter closed-state stability and channel activation. J Biol Chem 2021; 297:100808. [PMID: 34022226 PMCID: PMC8214192 DOI: 10.1016/j.jbc.2021.100808] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 11/19/2022] Open
Abstract
Ryanodine receptors (RyRs) are ion channels that mediate the release of Ca2+ from the sarcoplasmic reticulum/endoplasmic reticulum, mutations of which are implicated in a number of human diseases. The adjacent C-terminal domains (CTDs) of cardiac RyR (RyR2) interact with each other to form a ring-like tetrameric structure with the intersubunit interface undergoing dynamic changes during channel gating. This mobile CTD intersubunit interface harbors many disease-associated mutations. However, the mechanisms of action of these mutations and the role of CTD in channel function are not well understood. Here, we assessed the impact of CTD disease-associated mutations P4902S, P4902L, E4950K, and G4955E on Ca2+− and caffeine-mediated activation of RyR2. The G4955E mutation dramatically increased both the Ca2+-independent basal activity and Ca2+-dependent activation of [3H]ryanodine binding to RyR2. The P4902S and E4950K mutations also increased Ca2+ activation but had no effect on the basal activity of RyR2. All four disease mutations increased caffeine-mediated activation of RyR2 and reduced the threshold for activation and termination of spontaneous Ca2+ release. G4955D dramatically increased the basal activity of RyR2, whereas G4955K mutation markedly suppressed channel activity. Similarly, substitution of P4902 with a negatively charged residue (P4902D), but not a positively charged residue (P4902K), also dramatically increased the basal activity of RyR2. These data suggest that electrostatic interactions are involved in stabilizing the CTD intersubunit interface and that the G4955E disease mutation disrupts this interface, and thus the stability of the closed state. Our studies shed new insights into the mechanisms of action of RyR2 CTD disease mutations.
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Affiliation(s)
- Wenting Guo
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Lin Zhang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Bo Sun
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada; Medical School, Kunming University of Science and Technology, Kunming, China.
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.
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12
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Zhong X, Guo W, Wei J, Tang Y, Liu Y, Zhang JZ, Tan VH, Zhang L, Wang R, Jones PP, Napolitano C, Priori SG, Chen SRW. Identification of loss-of-function RyR2 mutations associated with idiopathic ventricular fibrillation and sudden death. Biosci Rep 2021; 41:BSR20210209. [PMID: 33825858 DOI: 10.1042/BSR20210209] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 03/24/2021] [Accepted: 04/06/2021] [Indexed: 11/23/2022] Open
Abstract
Mutations in cardiac ryanodine receptor (RyR2) are linked to catecholaminergic polymorphic ventricular tachycardia (CPVT). Most CPVT RyR2 mutations characterized are gain-of-function (GOF), indicating enhanced RyR2 function as a major cause of CPVT. Loss-of-function (LOF) RyR2 mutations have also been identified and are linked to a distinct entity of cardiac arrhythmia termed RyR2 Ca2+ release deficiency syndrome (CRDS). Exercise stress testing (EST) is routinely used to diagnose CPVT, but it is ineffective for CRDS. There is currently no effective diagnostic tool for CRDS in humans. An alternative strategy to assess the risk for CRDS is to directly determine the functional impact of the associated RyR2 mutations. To this end, we have functionally screened 18 RyR2 mutations that are associated with idiopathic ventricular fibrillation (IVF) or sudden death. We found two additional RyR2 LOF mutations E4146K and G4935R. The E4146K mutation markedly suppressed caffeine activation of RyR2 and abolished store overload induced Ca2+ release (SOICR) in human embryonic kidney 293 (HEK293) cells. E4146K also severely reduced cytosolic Ca2+ activation and abolished luminal Ca2+ activation of single RyR2 channels. The G4935R mutation completely abolished caffeine activation of and [3H]ryanodine binding to RyR2. Co-expression studies showed that the G4935R mutation exerted dominant negative impact on the RyR2 wildtype (WT) channel. Interestingly, the RyR2-G4935R mutant carrier had a negative EST, and the E4146K carrier had a family history of sudden death during sleep, which are different from phenotypes of typical CPVT. Thus, our data further support the link between RyR2 LOF and a new entity of cardiac arrhythmias distinct from CPVT.
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13
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Zhang XH, Wei H, Xia Y, Morad M. Calcium signaling consequences of RyR2 mutations associated with CPVT1 introduced via CRISPR/Cas9 gene editing in human-induced pluripotent stem cell-derived cardiomyocytes: Comparison of RyR2-R420Q, F2483I, and Q4201R. Heart Rhythm. 2021;18:250-260. [PMID: 32931925 DOI: 10.1016/j.hrthm.2020.09.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 09/02/2020] [Accepted: 09/08/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) created from patients with catecholaminergic polymorphic ventricular tachycardia 1 (CPVT1) have been used to study CPVT1 arrhythmia. OBJECTIVE The purpose of this study was to evaluate the Ca2+ signaling aberrancies and pharmacological sensitivities of 3 CRISPR/Cas9-introduced CPVT1 mutations located in different molecular domains of ryanodine receptor 2 (RyR2). METHODS CRISPR/Cas9-engineered hiPSC-CMs carrying RyR2 mutations-R420Q, Q4201R, and F2483I-were voltage clamped, and their electrophysiology, pharmacology, and Ca2+ signaling phenotypes measured using total internal reflection fluorescence microscopy. RESULTS R420Q and Q4201R mutant hiPSC-CMs exhibit irregular, long-lasting, spatially wandering Ca2+ sparks and aberrant Ca2+ releases similar to F2483I unlike the wild-type myocytes. Large sarcoplasmic reticulum (SR) Ca2+ leaks and smaller SR Ca2+ contents were detected in cells expressing Q4201R and F2483I, but not R420Q. Fractional Ca2+ release and calcium-induced calcium release gain were higher in Q4201R than in R420Q and F2483I hiPSC-CMs. JTV519 was equally effective in suppressing Ca2+ sparks, waves, and SR Ca2+ leaks in hiPSC-CMs derived from all 3 mutant lines. Flecainide and dantrolene similarly suppressed SR Ca2+ leaks, but were less effective in decreasing spark frequency and durations. CONCLUSION CRISPR/Cas9 gene editing of hiPSCs provides a novel approach in studying CPVT1-associated RyR2 mutations and suggests that Ca2+-signaling aberrancies and drug sensitivities may vary depending on the mutation site.
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14
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Guo W, Sun B, Estillore JP, Wang R, Chen SRW. The central domain of cardiac ryanodine receptor governs channel activation, regulation, and stability. J Biol Chem 2020; 295:15622-15635. [PMID: 32878990 DOI: 10.1074/jbc.ra120.013512] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 08/25/2020] [Indexed: 11/06/2022] Open
Abstract
Structural analyses identified the central domain of ryanodine receptor (RyR) as a transducer converting conformational changes in the cytoplasmic platform to the RyR gate. The central domain is also a regulatory hub encompassing the Ca2+-, ATP-, and caffeine-binding sites. However, the role of the central domain in RyR activation and regulation has yet to be defined. Here, we mutated five residues that form the Ca2+ activation site and 10 residues with negatively charged or oxygen-containing side chains near the Ca2+ activation site. We also generated eight disease-associated mutations within the central domain of RyR2. We determined the effect of these mutations on Ca2+, ATP, and caffeine activation and Mg2+ inhibition of RyR2. Mutating the Ca2+ activation site markedly reduced the sensitivity of RyR2 to Ca2+ and caffeine activation. Unexpectedly, Ca2+ activation site mutation E3848A substantially enhanced the Ca2+-independent basal activity of RyR2, suggesting that E3848A may also affect the stability of the closed state of RyR2. Mutations in the Ca2+ activation site also abolished the effect of ATP/caffeine on the Ca2+-independent basal activity, suggesting that the Ca2+ activation site is also a critical determinant of ATP/caffeine action. Mutating residues with negatively charged or oxygen-containing side chains near the Ca2+ activation site significantly altered Ca2+ and caffeine activation and reduced Mg2+ inhibition. Furthermore, disease-associated RyR2 mutations within the central domain significantly enhanced Ca2+ and caffeine activation and reduced Mg2+ inhibition. Our data demonstrate that the central domain plays an important role in channel activation, channel regulation, and closed state stability.
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Affiliation(s)
- Wenting Guo
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - Bo Sun
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Medical School, Kunming University of Science and Technology, Kunming, China
| | - John Paul Estillore
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada.
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15
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Saadeh K, Achercouk Z, Fazmin IT, Nantha Kumar N, Salvage SC, Edling CE, Huang CLH, Jeevaratnam K. Protein expression profiles in murine ventricles modeling catecholaminergic polymorphic ventricular tachycardia: effects of genotype and sex. Ann N Y Acad Sci 2020; 1478:63-74. [PMID: 32713021 DOI: 10.1111/nyas.14426] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/27/2020] [Accepted: 06/15/2020] [Indexed: 12/12/2022]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is associated with mutations in the cardiac ryanodine receptor (RyR2). These result in stress-induced ventricular arrhythmic episodes, with clinical symptoms and prognosis reported more severe in male than female patients. Murine homozygotic RyR2-P2328S (RyR2S/S ) hearts replicate the proarrhythmic CPVT phenotype of abnormal sarcoplasmic reticular Ca2+ leak and disrupted Ca2+ homeostasis. In addition, RyR2S/S hearts show decreased myocardial action potential conduction velocities (CV), all features implicated in arrhythmic trigger and substrate. The present studies explored for independent and interacting effects of RyR2S/S genotype and sex on expression levels of molecular determinants of Ca2+ homeostasis (CASQ2, FKBP12, SERCA2a, NCX1, and CaV 1.2) and CV (NaV 1.5, Connexin (Cx)-43, phosphorylated-Cx43, and TGF-β1) in mice. Expression levels of Ca2+ homeostasis proteins were not altered, hence implicating abnormal RyR2 function alone in disrupted cytosolic Ca2+ homeostasis. Furthermore, altered NaV 1.5, phosphorylated Cx43, and TGF-β1 expression were not implicated in the development of slowed CV. By contrast, decreased Cx43 expression correlated with slowed CV, in female, but not male, RyR2S/S mice. The CV changes may reflect acute actions of the increased cytosolic Ca2+ on NaV 1.5 and Cx43 function.
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Affiliation(s)
- Khalil Saadeh
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Zakaria Achercouk
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Ibrahim T Fazmin
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom
| | - Nakulan Nantha Kumar
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Samantha C Salvage
- Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom.,Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Charlotte E Edling
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Christopher L-H Huang
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom.,Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom
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16
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Søndergaard MT, Liu Y, Guo W, Wei J, Wang R, Brohus M, Overgaard MT, Chen SRW. Role of cardiac ryanodine receptor calmodulin-binding domains in mediating the action of arrhythmogenic calmodulin N-domain mutation N54I. FEBS J 2019; 287:2256-2280. [PMID: 31763755 DOI: 10.1111/febs.15147] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 09/12/2019] [Accepted: 11/19/2019] [Indexed: 11/27/2022]
Abstract
The Ca2+ -sensing protein calmodulin (CaM) inhibits cardiac ryanodine receptor (RyR2)-mediated Ca2+ release. CaM mutations associated with arrhythmias and sudden cardiac death have been shown to diminish CaM-dependent inhibition of RyR2, but the underlying mechanisms are not well understood. Nearly all arrhythmogenic CaM mutations identified are located in the C-domain of CaM and exert marked effects on Ca2+ binding to CaM and on the CaM C-domain interaction with the CaM-binding domain 2 (CaMBD2) in RyR2. Interestingly, the arrhythmogenic N-domain mutation CaM-N54I has little or no effect on Ca2+ binding to CaM or the CaM C-domain-RyR2 CaMBD2 interaction, unlike all CaM C-domain mutations. This suggests that CaM-N54I may diminish CaM-dependent RyR2 inhibition by affecting CaM N-domain interactions with RyR2 CaMBDs other than CaMBD2. To explore this possibility, we assessed the effects of deleting each of the four known CaMBDs in RyR2 (CaMBD1a, -1b, -2, or -3) on the CaM-dependent inhibition of RyR2-mediated Ca2+ release in HEK293 cells. We found that removing CaMBD1a, CaMBD1b, or CaMBD3 did not alter the effects of CaM-N54I or CaM-WT on RyR2 inhibition. On the other hand, deleting RyR2-CaMBD2 abolished the effects of both CaM-N54I and CaM-WT. Our results support that CaM-N54I causes aberrant RyR2 regulation via an uncharacterized CaMBD or less likely CaMBD2, and that RyR2 CaMBD2 is required for the actions of both N- and C-domain CaM mutations. Moreover, our results show that CaMBD1a is central to RyR2 regulation, but CaMBD1a, CaMBD1b, and CaMBD3 are not required for CaM-dependent inhibition of RyR2 in HEK293 cells.
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Affiliation(s)
- Mads T Søndergaard
- Department of Chemistry and Bioscience, Aalborg University, Denmark.,Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Yingjie Liu
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Malene Brohus
- Department of Chemistry and Bioscience, Aalborg University, Denmark
| | | | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
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17
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Pölönen RP, Swan H, Aalto-Setälä K. Mutation-specific differences in arrhythmias and drug responses in CPVT patients: simultaneous patch clamp and video imaging of iPSC derived cardiomyocytes. Mol Biol Rep 2019; 47:1067-1077. [PMID: 31786768 DOI: 10.1007/s11033-019-05201-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 11/21/2019] [Indexed: 12/26/2022]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited cardiac disease characterized by arrhythmias under adrenergic stress. Mutations in the cardiac ryanodine receptor (RYR2) are the leading cause for CPVT. We characterized electrophysiological properties of CPVT patient-specific induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) carrying different mutations in RYR2 and evaluated effects of carvedilol and flecainide on action potential (AP) and contractile properties of hiPSC-CMs. iPSC-CMs were generated from skin biopsies of CPVT patients carrying exon 3 deletion (E3D) and L4115F mutation in RYR2. APs and contractile movement were recorded simultaneously from the same hiPSC-CMs. Differences in AP properties of ventricular like CMs were seen in CPVT and control CMs: APD90 of both E3D (n = 20) and L4115F (n = 25) CPVT CMs was shorter than in control CMs (n = 15). E3D-CPVT CMs had shortest AP duration, lowest AP amplitude, upstroke velocity and more depolarized diastolic potential than controls. Adrenaline had positive and carvedilol and flecainide negative chronotropic effect in all hiPSC CMs. CPVT CMs had increased amount of delayed after depolarizations (DADs) and early after depolarizations (EADs) after adrenaline exposure. E3D CPVT CMs had the most DADs, EADs, and tachyarrhythmia. Discordant negatively coupled alternans was seen in L4115F CPVT CMs. Carvedilol cured almost all arrhythmias in L4115F CPVT CMs. Both drugs decreased contraction amplitude in all hiPSC CMs. E3D CPVT CMs have electrophysiological properties, which render them more prone to arrhythmias. iPSC-CMs provide a unique platform for disease modeling and drug screening for CPVT. Combining electrophysiological measurements, we can gain deeper insight into mechanisms of arrhythmias.
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Affiliation(s)
- R P Pölönen
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Arvo2 D441, 33520, Tampere, Finland.
| | - H Swan
- Helsinki University Hospital and Helsinki University, PO Box 340, 00029, Helsinki, Finland
| | - K Aalto-Setälä
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Arvo2 D441, 33520, Tampere, Finland
- Heart Center, Tampere University Hospital, Arvo Ylpön katu 34, Arvo2 D437, 33520, Tampere, Finland
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18
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Søndergaard MT, Liu Y, Brohus M, Guo W, Nani A, Carvajal C, Fill M, Overgaard MT, Chen SRW. Diminished inhibition and facilitated activation of RyR2-mediated Ca 2+ release is a common defect of arrhythmogenic calmodulin mutations. FEBS J 2019; 286:4554-4578. [PMID: 31230402 DOI: 10.1111/febs.14969] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/23/2019] [Accepted: 06/20/2019] [Indexed: 02/06/2023]
Abstract
A number of calmodulin (CaM) mutations cause severe cardiac arrhythmias, but their arrhythmogenic mechanisms are unclear. While some of the arrhythmogenic CaM mutations have been shown to impair CaM-dependent inhibition of intracellular Ca2+ release through the ryanodine receptor type 2 (RyR2), the impact of a majority of these mutations on RyR2 function is unknown. Here, we investigated the effect of 14 arrhythmogenic CaM mutations on the CaM-dependent RyR2 inhibition. We found that all the arrhythmogenic CaM mutations tested diminished CaM-dependent inhibition of RyR2-mediated Ca2+ release and increased store-overload induced Ca2+ release (SOICR) in HEK293 cells. Moreover, all the arrhythmogenic CaM mutations tested either failed to inhibit or even promoted RyR2-mediated Ca2+ release in permeabilized HEK293 cells with elevated cytosolic Ca2+ , which was markedly different from the inhibitory action of CaM wild-type. The CaM mutations also altered the Ca2+ -dependency of CaM binding to the RyR2 CaM-binding domain. These results demonstrate that diminished inhibition, and even facilitated activation, of RyR2-mediated Ca2+ release is a common defect of arrhythmogenic CaM mutations.
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Affiliation(s)
- Mads T Søndergaard
- Department of Chemistry and Bioscience, Aalborg University, Denmark.,Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada
| | - Yingjie Liu
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada
| | - Malene Brohus
- Department of Chemistry and Bioscience, Aalborg University, Denmark
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada
| | - Alma Nani
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL, USA
| | - Catherine Carvajal
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL, USA
| | - Michael Fill
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL, USA
| | | | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada.,Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL, USA
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19
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Salvage SC, Gallant EM, Beard NA, Ahmad S, Valli H, Fraser JA, Huang CLH, Dulhunty AF. Ion channel gating in cardiac ryanodine receptors from the arrhythmic RyR2-P2328S mouse. J Cell Sci 2019; 132:jcs.229039. [PMID: 31028179 PMCID: PMC6550012 DOI: 10.1242/jcs.229039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 04/16/2019] [Indexed: 12/20/2022] Open
Abstract
Mutations in the cardiac ryanodine receptor Ca2+ release channel (RyR2) can cause deadly ventricular arrhythmias and atrial fibrillation (AF). The RyR2-P2328S mutation produces catecholaminergic polymorphic ventricular tachycardia (CPVT) and AF in hearts from homozygous RyR2P2328S/P2328S (denoted RyR2S/S) mice. We have now examined P2328S RyR2 channels from RyR2S/S hearts. The activity of wild-type (WT) and P2328S RyR2 channels was similar at a cytoplasmic [Ca2+] of 1 mM, but P2328S RyR2 was significantly more active than WT at a cytoplasmic [Ca2+] of 1 µM. This was associated with a >10-fold shift in the half maximal activation concentration (AC50) for Ca2+ activation, from ∼3.5 µM Ca2+ in WT RyR2 to ∼320 nM in P2328S channels and an unexpected >1000-fold shift in the half maximal inhibitory concentration (IC50) for inactivation from ∼50 mM in WT channels to ≤7 μM in P2328S channels, which is into systolic [Ca2+] levels. Unexpectedly, the shift in Ca2+ activation was not associated with changes in sub-conductance activity, S2806 or S2814 phosphorylation or the level of FKBP12 (also known as FKBP1A) bound to the channels. The changes in channel activity seen with the P2328S mutation correlate with altered Ca2+ homeostasis in myocytes from RyR2S/S mice and the CPVT and AF phenotypes.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Samantha C Salvage
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK.,Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Esther M Gallant
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, 131 Garran Road, Acton ACT 2601, Australia
| | - Nicole A Beard
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Bruce, ACT 2617, Australia
| | - Shiraz Ahmad
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - Haseeb Valli
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - James A Fraser
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - Christopher L-H Huang
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK.,Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Angela F Dulhunty
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, 131 Garran Road, Acton ACT 2601, Australia
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Lieve KVV, Verhagen JMA, Wei J, Bos JM, van der Werf C, Rosés I Noguer F, Mancini GMS, Guo W, Wang R, van den Heuvel F, Frohn-Mulder IME, Shimizu W, Nogami A, Horigome H, Roberts JD, Leenhardt A, Crijns HJG, Blank AC, Aiba T, Wiesfeld ACP, Blom NA, Sumitomo N, Till J, Ackerman MJ, Chen SRW, van de Laar IMBH, Wilde AAM. Linking the heart and the brain: Neurodevelopmental disorders in patients with catecholaminergic polymorphic ventricular tachycardia. Heart Rhythm 2018; 16:220-228. [PMID: 30170228 DOI: 10.1016/j.hrthm.2018.08.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Indexed: 11/25/2022]
Abstract
BACKGROUND Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an uncommon inherited arrhythmia disorder characterized by adrenergically evoked ventricular arrhythmias. Mutations in the cardiac calcium release channel/ryanodine receptor gene (RYR2) are identified in the majority of patients with CPVT. RyR2 is also the major RyR isoform expressed in the brain. OBJECTIVE The purpose of this study was to estimate the prevalence of intellectual disability (ID) and other neurodevelopmental disorders (NDDs) in RYR2-associated CPVT (CPVT1) and to study the characteristics of these patients. METHODS We reviewed the medical records of all CPVT1 patients from 12 international centers and analyzed the characteristics of all CPVT1 patients with concomitant NDDs. We functionally characterized the mutations to assess their response to caffeine activation. We did not correct for potential confounders. RESULTS Among 421 CPVT1 patients, we identified 34 patients with ID (8%; 95% confidence interval 6%-11%). Median age at diagnosis was 9.3 years (interquartile range 7.0-14.5). Parents for 24 of 34 patients were available for genetic testing, and 13 of 24 (54%) had a de novo mutation. Severity of ID ranged from mild to severe and was accompanied by other NDDs in 9 patients (26%). Functionally, the ID-associated mutations showed a markedly enhanced response of RyR2 to activation by caffeine. Seventeen patients (50%) also had supraventricular arrhythmias. During median follow-up of 8.4 years (interquartile range 1.8-12.4), 15 patients (45%) experienced an arrhythmic event despite adequate therapy. CONCLUSION Our study indicates that ID is more prevalent among CPVT1 patients (8%) than in the general population (1%-3%). This subgroup of CPVT1 patients reveals a malignant cardiac phenotype with marked supraventricular and ventricular arrhythmias.
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Affiliation(s)
- Krystien V V Lieve
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Judith M A Verhagen
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jinhong Wei
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - J Martijn Bos
- Department of Cardiovascular Diseases, Division of Heart Rhythm Services, Mayo Clinic, Rochester, Minnesota, Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota, and Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Christian van der Werf
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | | | - Grazia M S Mancini
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Wenting Guo
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Ruiwu Wang
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Freek van den Heuvel
- Department of Pediatric Cardiology, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, The Netherlands
| | - Ingrid M E Frohn-Mulder
- Department of Pediatric Cardiology, Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan; Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Akihiko Nogami
- Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Hitoshi Horigome
- Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Jason D Roberts
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
| | - Antoine Leenhardt
- CNMR Maladies Cardiaques Héréditaires Rares, Hôpital Bichat, Université Paris Diderot, Sorbonne Paris Cité, Paris, France, and AP-HP, Service de Cardiologie, Hôpital Bichat, Paris, France
| | - Harry J G Crijns
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Faculty of Health, Medicine, and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Andreas C Blank
- Department of Pediatric Cardiology, Wilhelmina Children's Hospital, University Medical Center, Utrecht, The Netherlands
| | - Takeshi Aiba
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Ans C P Wiesfeld
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Nico A Blom
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands; Department of Pediatric Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Naokata Sumitomo
- Department of Pediatric Cardiology, Saitama Medical University International Medical Center, Saitama, Japan
| | - Jan Till
- Department of Cardiology, Royal Brompton Hospital, London, United Kingdom
| | - Michael J Ackerman
- Department of Cardiovascular Diseases, Division of Heart Rhythm Services, Mayo Clinic, Rochester, Minnesota, Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota, and Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - S R Wayne Chen
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Ingrid M B H van de Laar
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Arthur A M Wilde
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands; Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Kingdom of Saudi Arabia.
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