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Abstract
Calcium ions (Ca2+) are the basis of a unique and potent array of cellular responses. Calmodulin (CaM) is a small but vital protein that is able to rapidly transmit information about changes in Ca2+ concentrations to its regulatory targets. CaM plays a critical role in cellular Ca2+ signaling, and interacts with a myriad of target proteins. Ca2+-dependent modulation by CaM is a major component of a diverse array of processes, ranging from gene expression in neurons to the shaping of the cardiac action potential in heart cells. Furthermore, the protein sequence of CaM is highly evolutionarily conserved, and identical CaM proteins are encoded by three independent genes (CALM1-3) in humans. Mutations within any of these three genes may lead to severe cardiac deficits including severe long QT syndrome (LQTS) and/or catecholaminergic polymorphic ventricular tachycardia (CPVT). Research into disease-associated CaM variants has identified several proteins modulated by CaM that are likely to underlie the pathogenesis of these calmodulinopathies, including the cardiac L-type Ca2+ channel (LTCC) CaV1.2, and the sarcoplasmic reticulum Ca2+ release channel, ryanodine receptor 2 (RyR2). Here, we review the research that has been done to identify calmodulinopathic CaM mutations and evaluate the mechanisms underlying their role in disease.
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Affiliation(s)
- John W. Hussey
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Worawan B. Limpitikul
- Department of Medicine, Division of Cardiology, Massachusetts General Hospital, Boston, MA, USA
| | - Ivy E. Dick
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
- CONTACT Ivy E. Dick School of Medicine, University of Maryland, Baltimore, MD21210
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2
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Kang PW, Woodbury L, Angsutararux P, Sambare N, Shi J, Marras M, Abella C, Bedi A, Zinn D, Cui J, Silva JR. Arrhythmia-associated calmodulin variants interact with KCNQ1 to confer aberrant membrane trafficking and function. PNAS NEXUS 2023; 2:pgad335. [PMID: 37965565 PMCID: PMC10642763 DOI: 10.1093/pnasnexus/pgad335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 10/04/2023] [Indexed: 11/16/2023]
Abstract
Missense variants in calmodulin (CaM) predispose patients to arrhythmias associated with high mortality rates ("calmodulinopathy"). As CaM regulates many key cardiac ion channels, an understanding of disease mechanism associated with CaM variant arrhythmias requires elucidating individual CaM variant effects on distinct channels. One key CaM regulatory target is the KCNQ1 (KV7.1) voltage-gated potassium channel that carries the IKs current. Yet, relatively little is known as to how CaM variants interact with KCNQ1 or affect its function. Here, we take a multipronged approach employing a live-cell fluorescence resonance energy transfer binding assay, fluorescence trafficking assay, and functional electrophysiology to characterize >10 arrhythmia-associated CaM variants for effect on KCNQ1 CaM binding, membrane trafficking, and channel function. We identify one variant (G114W) that exhibits severely weakened binding to KCNQ1 but find that most other CaM variants interact with similar binding affinity to KCNQ1 when compared with CaM wild-type over physiological Ca2+ ranges. We further identify several CaM variants that affect KCNQ1 and IKs membrane trafficking and/or baseline current activation kinetics, thereby delineating KCNQ1 dysfunction in calmodulinopathy. Lastly, we identify CaM variants with no effect on KCNQ1 function. This study provides extensive functional data that reveal how CaM variants contribute to creating a proarrhythmic substrate by causing abnormal KCNQ1 membrane trafficking and current conduction. We find that CaM variant regulation of KCNQ1 is not uniform with effects varying from benign to significant loss of function, suggesting how CaM variants predispose patients to arrhythmia via the dysregulation of multiple cardiac ion channels. Classification: Biological, Health, and Medical Sciences, Physiology.
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Affiliation(s)
- Po wei Kang
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
| | - Lucy Woodbury
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
| | - Paweorn Angsutararux
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
| | - Namit Sambare
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
| | - Jingyi Shi
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
| | - Martina Marras
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
| | - Carlota Abella
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
| | - Anish Bedi
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
| | - DeShawn Zinn
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
| | - Jianmin Cui
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
| | - Jonathan R Silva
- Department of Biomedical Engineering, Washington University in St.Louis, St. Louis, MO 63130, USA
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Wren LM, DeKeyser JM, Barefield DY, Hawkins NA, McNally EM, Kearney JA, Wasserstrom JA, George AL. Sex and Gene Influence Arrhythmia Susceptibility in Murine Models of Calmodulinopathy. Circ Arrhythm Electrophysiol 2023; 16:e010891. [PMID: 37589122 PMCID: PMC10530303 DOI: 10.1161/circep.122.010891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 07/16/2023] [Indexed: 08/18/2023]
Abstract
BACKGROUND Pathogenic variants in genes encoding CaM (calmodulin) are associated with a life-threatening ventricular arrhythmia syndrome (calmodulinopathy). The in vivo consequences of CaM variants have not been studied extensively and there is incomplete understanding of the genotype-phenotype relationship for recurrent variants. We investigated effects of different factors on calmodulinopathy phenotypes using 2 mouse models with a recurrent pathogenic variant (N98S) in Calm1 or Calm2. METHODS Genetically engineered mice with heterozygous N98S pathogenic variants in Calm1 or Calm2 were generated. Differences between the sexes and affected genes were assessed using multiple physiological assays at the cellular and whole animal levels. Statistical significance among groups was evaluated using 1-way ANOVA or the Kruskal-Wallis test when data were not normally distributed. RESULTS Calm1N98S/+ (Calm1S/+) or Calm2N98S/+ (Calm2S/+) mice exhibited sinus bradycardia and were more susceptible to arrhythmias after exposure to epinephrine and caffeine. Male Calm1S/+ mice had the most severe arrhythmia phenotype with evidence of early embryonic lethality, greater susceptibility for arrhythmic events, frequent premature beats, corrected QT prolongation, and more heart rate variability after epinephrine and caffeine than females with the same genotype. Calm2 S/+ mice exhibited a less severe phenotype, with female Calm2 S/+ mice having the least severe arrhythmia susceptibility. Flecainide was not effective in preventing arrhythmias in heterozygous CaM-N98S mice. Intracellular Ca2+ transients observed in isolated ventricular cardiomyocytes from male heterozygous CaM-N98S mice had lower peak amplitudes and slower sarcoplasmic reticulum Ca2+ release following in vitro exposure to epinephrine and caffeine, which were not observed in cardiomyocytes from heterozygous female CaM-N98S mice. CONCLUSIONS We report heterogeneity in arrhythmia susceptibility and cardiomyocyte Ca2+ dynamics among male and female mice heterozygous for a recurrent pathogenic variant in Calm1 or Calm2, illustrating a complex calmodulinopathy phenotype in vivo. Further investigation of sex and genetic differences may help identify the molecular basis for this heterogeneity.
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Affiliation(s)
- Lisa M Wren
- Department of Pharmacology (L.M.W., J.-M.D., N.A.H., J.A.K., A.L.G.), The Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Jean-Marc DeKeyser
- Department of Pharmacology (L.M.W., J.-M.D., N.A.H., J.A.K., A.L.G.), The Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - David Y Barefield
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL (D.Y.B.)
| | - Nicole A Hawkins
- Department of Pharmacology (L.M.W., J.-M.D., N.A.H., J.A.K., A.L.G.), The Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Elizabeth M McNally
- Center for Genetic Medicine (E.M.M.), The Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Jennifer A Kearney
- Department of Pharmacology (L.M.W., J.-M.D., N.A.H., J.A.K., A.L.G.), The Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - J Andrew Wasserstrom
- Department of Medicine (J.A.W.), The Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Alfred L George
- Department of Pharmacology (L.M.W., J.-M.D., N.A.H., J.A.K., A.L.G.), The Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL
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McCormick L, Wadmore K, Milburn A, Gupta N, Morris R, Held M, Prakash O, Carr J, Barrett‐Jolley R, Dart C, Helassa N. Long QT syndrome-associated calmodulin variants disrupt the activity of the slowly activating delayed rectifier potassium channel. J Physiol 2023; 601:3739-3764. [PMID: 37428651 PMCID: PMC10952621 DOI: 10.1113/jp284994] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 06/21/2023] [Indexed: 07/12/2023] Open
Abstract
Calmodulin (CaM) is a highly conserved mediator of calcium (Ca2+ )-dependent signalling and modulates various cardiac ion channels. Genotyping has revealed several CaM mutations associated with long QT syndrome (LQTS). LQTS patients display prolonged ventricular recovery times (QT interval), increasing their risk of incurring life-threatening arrhythmic events. Loss-of-function mutations to Kv7.1 (which drives the slow delayed rectifier potassium current, IKs, a key ventricular repolarising current) are the largest contributor to congenital LQTS (>50% of cases). CaM modulates Kv7.1 to produce a Ca2+ -sensitive IKs, but little is known about the consequences of LQTS-associated CaM mutations on Kv7.1 function. Here, we present novel data characterising the biophysical and modulatory properties of three LQTS-associated CaM variants (D95V, N97I and D131H). We showed that mutations induced structural alterations in CaM and reduced affinity for Kv7.1, when compared with wild-type (WT). Using HEK293T cells expressing Kv7.1 channel subunits (KCNQ1/KCNE1) and patch-clamp electrophysiology, we demonstrated that LQTS-associated CaM variants reduced current density at systolic Ca2+ concentrations (1 μm), revealing a direct QT-prolonging modulatory effect. Our data highlight for the first time that LQTS-associated perturbations to CaM's structure impede complex formation with Kv7.1 and subsequently result in reduced IKs. This provides a novel mechanistic insight into how the perturbed structure-function relationship of CaM variants contributes to the LQTS phenotype. KEY POINTS: Calmodulin (CaM) is a ubiquitous, highly conserved calcium (Ca2+ ) sensor playing a key role in cardiac muscle contraction. Genotyping has revealed several CaM mutations associated with long QT syndrome (LQTS), a life-threatening cardiac arrhythmia syndrome. LQTS-associated CaM variants (D95V, N97I and D131H) induced structural alterations, altered binding to Kv7.1 and reduced IKs. Our data provide a novel mechanistic insight into how the perturbed structure-function relationship of CaM variants contributes to the LQTS phenotype.
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Affiliation(s)
- Liam McCormick
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
- Manchester Centre for Genomic Medicine, North West Genomic Laboratory HubSaint Mary's HospitalManchesterUK
| | - Kirsty Wadmore
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
| | - Amy Milburn
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
| | - Nitika Gupta
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
| | - Rachael Morris
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
| | - Marie Held
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
| | - Ohm Prakash
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
| | - Joseph Carr
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
| | - Richard Barrett‐Jolley
- Department of Musculoskeletal and Ageing Science, Institute of Life Course and Medical Sciences, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
| | - Caroline Dart
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
| | - Nordine Helassa
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life SciencesUniversity of LiverpoolLiverpoolUK
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Brohus M, Busuioc AO, Wimmer R, Nyegaard M, Overgaard MT. Calmodulin mutations affecting Gly114 impair binding to the Na V1.5 IQ-domain. Front Pharmacol 2023; 14:1210140. [PMID: 37663247 PMCID: PMC10469309 DOI: 10.3389/fphar.2023.1210140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 07/25/2023] [Indexed: 09/05/2023] Open
Abstract
Missense variants in CALM genes encoding the Ca2+-binding protein calmodulin (CaM) cause severe cardiac arrhythmias. The disease mechanisms have been attributed to dysregulation of RyR2, for Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) and/or CaV1.2, for Long-QT Syndrome (LQTS). Recently, a novel CALM2 variant, G114R, was identified in a mother and two of her four children, all of whom died suddenly while asleep at a young age. The G114R variant impairs closure of CaV1.2 and RyR2, consistent with a CPVT and/or mild LQTS phenotype. However, the children carrying the CALM2 G114R variant displayed a phenotype commonly observed with variants in NaV1.5, i.e., Brugada Syndrome (BrS) or LQT3, where death while asleep is a common feature. We therefore hypothesized that the G114R variant specifically would interfere with NaV1.5 binding. Here, we demonstrate that CaM binding to the NaV1.5 IQ-domain is severely impaired for two CaM variants G114R and G114W. The impact was most severe at low and intermediate Ca2+ concentrations (up to 4 µM) resulting in more than a 50-fold reduction in NaV1.5 binding affinity, and a smaller 1.5 to 11-fold reduction at high Ca2+ concentrations (25-400 µM). In contrast, the arrhythmogenic CaM-N98S variant only induced a 1.5-fold reduction in NaV1.5 binding and only at 4 µM Ca2+. A non-arrhythmogenic I10T variant in CaM did not impair NaV1.5 IQ binding. These data suggest that the interaction between NaV1.5 and CaM is decreased with certain CaM variants, which may alter the cardiac sodium current, INa. Overall, these results suggest that the phenotypic spectrum of calmodulinopathies may likely expand to include BrS- and/or LQT3-like traits.
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Affiliation(s)
- Malene Brohus
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Ana-Octavia Busuioc
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Reinhard Wimmer
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Mette Nyegaard
- Department of Health Science and Technology, Aalborg University, Gistrup, Denmark
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Kang PW, Woodbury L, Angsutararux P, Sambare N, Shi J, Marras M, Abella C, Bedi A, Zinn D, Cui J, Silva JR. Arrhythmia-associated Calmodulin Variants Interact with KCNQ1 to Confer Aberrant Membrane Trafficking and Function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.28.526031. [PMID: 36747728 PMCID: PMC9900995 DOI: 10.1101/2023.01.28.526031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Rationale Missense variants in calmodulin (CaM) predispose patients to arrhythmias associated with high mortality rates. As CaM regulates several key cardiac ion channels, a mechanistic understanding of CaM variant-associated arrhythmias requires elucidating individual CaM variant effect on distinct channels. One key CaM regulatory target is the KCNQ1 (K V 7.1) voltage-gated potassium channel that underlie the I Ks current. Yet, relatively little is known as to how CaM variants interact with KCNQ1 or affect its function. Objective To observe how arrhythmia-associated CaM variants affect binding to KCNQ1, channel membrane trafficking, and KCNQ1 function. Methods and Results We combine a live-cell FRET binding assay, fluorescence trafficking assay, and functional electrophysiology to characterize >10 arrhythmia-associated CaM variants effect on KCNQ1. We identify one variant (G114W) that exhibits severely weakened binding to KCNQ1 but find that most other CaM variants interact with similar binding affinity to KCNQ1 when compared to CaM wild-type over physiological Ca 2+ ranges. We further identify several CaM variants that affect KCNQ1 and I Ks membrane trafficking and/or baseline current activation kinetics, thereby contextualizing KCNQ1 dysfunction in calmodulinopathy. Lastly, we delineate CaM variants with no effect on KCNQ1 function. Conclusions This study provides comprehensive functional data that reveal how CaM variants contribute to creating a pro-arrhythmic substrate by causing abnormal KCNQ1 membrane trafficking and current conduction. We find that CaM variant regulation of KCNQ1 is not uniform with effects varying from benign to significant loss of function. This study provides a new approach to collecting details of CaM binding that are key for understanding how CaM variants predispose patients to arrhythmia via the dysregulation of multiple cardiac ion channels.
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McCoy MD, Ullah A, Lederer WJ, Jafri MS. Understanding Calmodulin Variants Affecting Calcium-Dependent Inactivation of L-Type Calcium Channels through Whole-Cell Simulation of the Cardiac Ventricular Myocyte. Biomolecules 2022; 13:72. [PMID: 36671457 PMCID: PMC9855640 DOI: 10.3390/biom13010072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 12/31/2022] Open
Abstract
Mutations in the calcium-sensing protein calmodulin (CaM) have been linked to two cardiac arrhythmia diseases, Long QT Syndrome 14 (LQT14) and Catecholaminergic Polymorphic Ventricular Tachycardia Type 4 (CPVT4), with varying degrees of severity. Functional characterization of the CaM mutants most strongly associated with LQT14 show a clear disruption of the calcium-dependent inactivation (CDI) of the L-Type calcium channel (LCC). CPVT4 mutants on the other hand are associated with changes in their affinity to the ryanodine receptor. In clinical studies, some variants have been associated with both CPVT4 and LQT15. This study uses simulations in a model for excitation-contraction coupling in the rat ventricular myocytes to understand how LQT14 variant might give the functional phenotype similar to CPVT4. Changing the CaM-dependent transition rate by a factor of 0.75 corresponding to the D96V variant and by a factor of 0.90 corresponding to the F142L or N98S variants, in a physiologically based stochastic model of the LCC prolonger, the action potential duration changed by a small amount in a cardiac myocyte but did not disrupt CICR at 1, 2, and 4 Hz. Under beta-adrenergic simulation abnormal excitation-contraction coupling was observed above 2 Hz pacing for the mutant CaM. The same conditions applied under beta-adrenergic stimulation led to the rapid onset of arrhythmia in the mutant CaM simulations. Simulations with the LQT14 mutations under the conditions of rapid pacing with beta-adrenergic stimulation drives the cardiac myocyte toward an arrhythmic state known as Ca2+ overload. These simulations provide a mechanistic link to a disease state for LQT14-associated mutations in CaM to yield a CPVT4 phenotype. The results show that small changes to the CaM-regulated inactivation of LCC promote arrhythmia and underscore the significance of CDI in proper heart function.
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Affiliation(s)
- Matthew D. McCoy
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
- Innovation Center for Biomedical Informatics, Department of Oncology, Georgetown University Medical Center, Georgetown University, Washington, DC 20057, USA
| | - Aman Ullah
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
| | - W. Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - M. Saleet Jafri
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 20201, USA
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Cumberland MJ, Riebel LL, Roy A, O’Shea C, Holmes AP, Denning C, Kirchhof P, Rodriguez B, Gehmlich K. Basic Research Approaches to Evaluate Cardiac Arrhythmia in Heart Failure and Beyond. Front Physiol 2022; 13:806366. [PMID: 35197863 PMCID: PMC8859441 DOI: 10.3389/fphys.2022.806366] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 01/10/2022] [Indexed: 12/20/2022] Open
Abstract
Patients with heart failure often develop cardiac arrhythmias. The mechanisms and interrelations linking heart failure and arrhythmias are not fully understood. Historically, research into arrhythmias has been performed on affected individuals or in vivo (animal) models. The latter however is constrained by interspecies variation, demands to reduce animal experiments and cost. Recent developments in in vitro induced pluripotent stem cell technology and in silico modelling have expanded the number of models available for the evaluation of heart failure and arrhythmia. An agnostic approach, combining the modalities discussed here, has the potential to improve our understanding for appraising the pathology and interactions between heart failure and arrhythmia and can provide robust and validated outcomes in a variety of research settings. This review discusses the state of the art models, methodologies and techniques used in the evaluation of heart failure and arrhythmia and will highlight the benefits of using them in combination. Special consideration is paid to assessing the pivotal role calcium handling has in the development of heart failure and arrhythmia.
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Affiliation(s)
- Max J. Cumberland
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Leto L. Riebel
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Ashwin Roy
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Christopher O’Shea
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Andrew P. Holmes
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Chris Denning
- Stem Cell Biology Unit, Biodiscovery Institute, British Heart Foundation Centre for Regenerative Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- University Heart and Vascular Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Blanca Rodriguez
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Katja Gehmlich
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford and British Heart Foundation Centre of Research Excellence Oxford, Oxford, United Kingdom
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Tang JKK, Rabkin SW. Hypocalcemia-Induced QT Interval Prolongation. Cardiology 2022; 147:191-195. [PMID: 35078204 DOI: 10.1159/000515985] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 03/10/2021] [Indexed: 11/19/2022]
Abstract
An 87-year-old man with a history of transcatheter aortic valve replacement, pulmonary hypertension, diastolic dysfunction with preserved systolic function, and myelofibrosis had a 12-lead ECG showed a prolonged QT interval of 508 ms with heart-rate correction placing it in the 99th percentile of the population. Reduction in the dose of furosemide and calcium supplementation increased serum calcium and shortened the QT interval. This case provides an opportunity to examine newer concepts for the understanding of the mechanisms by which hypocalcemia might induce QT prolongation. Hypocalcemia likely produces corrected QT interval prolongation primarily through a calcium-dependent inactivation (CDI) mechanism on the L-type calcium channel (LTCC). Lower extracellular calcium leads to a decreased ICaL, subsequently causing intracellular calcium to take longer to reach the critical threshold to induce CDI of the LTCC. The resulting prolonged repolarization of the ventricular myocyte can lead to early after-depolarizations and ensuing life-threatening ventricular arrhythmias. Genetic polymorphisms in Ca2+-binding protein calmodulin which can prolong QT, underscore the role for disturbances of intracellular myocardial calcium handling in arrhythmogenesis. Hypocalcemia is an under-recognized cause of QT prolongation and should be taken into careful consideration in patients presenting with incidental findings of a prolonged QT interval.
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Affiliation(s)
- Jacky K K Tang
- Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Simon W Rabkin
- Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
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Mahling R, Hovey L, Isbell HM, Marx DC, Miller MS, Kilpatrick AM, Weaver LD, Yoder JB, Kim EH, Andresen CNJ, Li S, Shea MA. Na V1.2 EFL domain allosterically enhances Ca 2+ binding to sites I and II of WT and pathogenic calmodulin mutants bound to the channel CTD. Structure 2021; 29:1339-1356.e7. [PMID: 33770503 PMCID: PMC8458505 DOI: 10.1016/j.str.2021.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 12/23/2020] [Accepted: 03/03/2021] [Indexed: 11/23/2022]
Abstract
Neuronal voltage-gated sodium channel NaV1.2 C-terminal domain (CTD) binds calmodulin (CaM) constitutively at its IQ motif. A solution structure (6BUT) and other NMR evidence showed that the CaM N domain (CaMN) is structurally independent of the C-domain (CaMC) whether CaM is bound to the NaV1.2IQp (1,901-1,927) or NaV1.2CTD (1,777-1,937) with or without calcium. However, in the CaM + NaV1.2CTD complex, the Ca2+ affinity of CaMN was more favorable than in free CaM, while Ca2+ affinity for CaMC was weaker than in the CaM + NaV1.2IQp complex. The CTD EF-like (EFL) domain allosterically widened the energetic gap between CaM domains. Cardiomyopathy-associated CaM mutants (N53I(N54I), D95V(D96V), A102V(A103V), E104A(E105A), D129G(D130G), and F141L(F142L)) all bound the NaV1.2 IQ motif favorably under resting (apo) conditions and bound calcium normally at CaMN sites. However, only N53I and A102V bound calcium at CaMC sites at [Ca2+] < 100 μM. Thus, they are expected to respond like wild-type CaM to Ca2+ spikes in excitable cells.
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Affiliation(s)
- Ryan Mahling
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Liam Hovey
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Holly M Isbell
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Dagan C Marx
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Mark S Miller
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Adina M Kilpatrick
- Department of Physics and Astronomy, Drake University, Des Moines, IA 50311-4516, USA
| | - Lisa D Weaver
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Jesse B Yoder
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Elaine H Kim
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Corinne N J Andresen
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Shuxiang Li
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Madeline A Shea
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242-1109, USA.
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11
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Tsai WC, Chen PS, Rubart M. Calmodulinopathy in inherited arrhythmia syndromes. Tzu Chi Med J 2021; 33:339-344. [PMID: 34760628 PMCID: PMC8532581 DOI: 10.4103/tcmj.tcmj_182_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/02/2020] [Accepted: 10/07/2020] [Indexed: 11/04/2022] Open
Abstract
Calmodulin (CaM) is a ubiquitous intracellular calcium sensor that controls and regulates key cellular functions. In all vertebrates, three CaM genes located on separate chromosomes encode an identical 149 amino acid protein, implying an extraordinarily high level of evolutionary importance and suggesting that CaM mutations would be possibly fatal. Inherited arrhythmia syndromes comprise a spectrum of primary electrical disorders caused by mutations in genes encoding ion channels or associated proteins leading to various cardiac arrhythmias, unexplained syncope, and sudden cardiac death. CaM mutations have emerged as an independent entity among inherited arrhythmia syndromes, referred to as calmodulinopathies. The most common clinical presentation associated with calmodulinopathy is congenital long QT syndrome, followed by catecholaminergic polymorphic ventricular tachycardia, both of which significantly increase the possibility of repeated syncope, lethal arrhythmic events, and sudden cardiac death, especially in young individuals. Here, we aim to give an overview of biochemical and structural characteristics of CaM and progress toward updating current known CaM mutations and associated clinical phenotypes. We also review the possible mechanisms underlying calmodulinopathy, based on several key in vitro studies. We expect that further experimental studies are needed to explore the complexity of calmodulinopathy.
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Affiliation(s)
- Wen-Chin Tsai
- Department of Cardiology, Cardiovascular Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, and Tzu Chi University, Hualien, Taiwan
| | - Peng-Sheng Chen
- Department of Cardiology, Cedar-Sinai Medical Center, Los Angeles, CA, USA.,Krannert Institute of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Michael Rubart
- Krannert Institute of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Pediatrics, Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
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12
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Berchtold MW, Munk M, Kulej K, Porth I, Lorentzen L, Panina S, Zacharias T, Larsen MR, la Cour JM. The heart arrhythmia-linked D130G calmodulin mutation causes premature inhibitory autophosphorylation of CaMKII. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119119. [PMID: 34391760 DOI: 10.1016/j.bbamcr.2021.119119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 10/20/2022]
Abstract
The Ca2+/calmodulin (CaM)-dependent kinase II (CaMKII) is well known for transmitting Ca2+-signals, which leads to a multitude of physiological responses. Its functionality is believed to involve CaMKII holoenzyme dynamics where trans-autophosphorylation of the crucial phosphorylation site, T286 occurs. Phosphorylation of this site does not occur when stimulated exclusively with the arrhythmia associated D130G mutant form of CaM in vitro. Here, we present evidence that the loss-of-CaMKII function correlates with premature phosphorylation of its inhibitory phosphosite T306 in CaMKIIα and T307 in CaMKIIδ as this site was up to 20-fold more phosphorylated in the presence of D130G CaM compared to wildtype CaM. Indeed, changing this phosphosite to a non-phosphorylatable alanine reversed the inhibitory effect of D130G both in vitro and in live cell experiments. In addition, several phosphosites with so far undescribed functions directing the Ca2+-sensitivity of the CaMKII sensor were also affected by the presence of the D130G mutation implicating a role of several additional autophosphosites (besides T286 and T306/T307) so far not known to regulate CaMKII Ca2+ sensitivity. Furthermore, we show that introducing a D130G mutation in the CALM2 gene of the P19CL6 pluripotent mouse embryonic carcinoma cell line using CRISPR/Cas9 decreased the spontaneous beat frequency compared to wildtype cells when differentiated into cardiomyocytes supporting an alteration of cardiomyocyte physiology caused by this point mutation. In conclusion, our observations shed for the first time light on how the D130G CaM mutation interferes with the function of CaMKII and how it affects the beating frequency of cardiomyocyte-like cells.
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Affiliation(s)
| | - Mads Munk
- Department of Biology, University of Copenhagen, Denmark
| | - Katarzyna Kulej
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark; Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, USA
| | - Isabel Porth
- Department of Biology, University of Copenhagen, Denmark
| | - Lasse Lorentzen
- Department of Biology, University of Copenhagen, Denmark; Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Svetlana Panina
- Department of Biology, University of Copenhagen, Denmark; MonTa Biosciences ApS, Diplomvej 381, 2800 kgs Lyngby, Denmark
| | | | - Martin R Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark
| | - Jonas M la Cour
- Department of Biology, University of Copenhagen, Denmark; ChemoMetec A/S, Gydevang 43, 3450 Lillerød, Denmark
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13
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Woll KA, Van Petegem F. Calcium Release Channels: Structure and Function of IP3 Receptors and Ryanodine Receptors. Physiol Rev 2021; 102:209-268. [PMID: 34280054 DOI: 10.1152/physrev.00033.2020] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Ca2+-release channels are giant membrane proteins that control the release of Ca2+ from the endoplasmic and sarcoplasmic reticulum. The two members, ryanodine receptors (RyRs) and inositol-1,4,5-trisphosphate Receptors (IP3Rs), are evolutionarily related and are both activated by cytosolic Ca2+. They share a common architecture, but RyRs have evolved additional modules in the cytosolic region. Their massive size allows for the regulation by tens of proteins and small molecules, which can affect the opening and closing of the channels. In addition to Ca2+, other major triggers include IP3 for the IP3Rs, and depolarization of the plasma membrane for a particular RyR subtype. Their size has made them popular targets for study via electron microscopic methods, with current structures culminating near 3Å. The available structures have provided many new mechanistic insights int the binding of auxiliary proteins and small molecules, how these can regulate channel opening, and the mechanisms of disease-associated mutations. They also help scrutinize previously proposed binding sites, as some of these are now incompatible with the structures. Many questions remain around the structural effects of post-translational modifications, additional binding partners, and the higher-order complexes these channels can make in situ. This review summarizes our current knowledge about the structures of Ca2+-release channels and how this informs on their function.
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Affiliation(s)
- Kellie A Woll
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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14
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Mechanisms underlying pathological Ca 2+ handling in diseases of the heart. Pflugers Arch 2021; 473:331-347. [PMID: 33399957 PMCID: PMC10070045 DOI: 10.1007/s00424-020-02504-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/01/2020] [Accepted: 12/09/2020] [Indexed: 02/07/2023]
Abstract
Cardiomyocyte contraction relies on precisely regulated intracellular Ca2+ signaling through various Ca2+ channels and transporters. In this article, we will review the physiological regulation of Ca2+ handling and its role in maintaining normal cardiac rhythm and contractility. We discuss how inherited variants or acquired defects in Ca2+ channel subunits contribute to the development or progression of diseases of the heart. Moreover, we highlight recent insights into the role of protein phosphatase subunits and striated muscle preferentially expressed protein kinase (SPEG) in atrial fibrillation, heart failure, and cardiomyopathies. Finally, this review summarizes current drug therapies and new advances in genome editing as therapeutic strategies for the cardiac diseases caused by aberrant intracellular Ca2+ signaling.
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15
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McCoy MD, Hamre J, Klimov DK, Jafri MS. Predicting Genetic Variation Severity Using Machine Learning to Interpret Molecular Simulations. Biophys J 2020; 120:189-204. [PMID: 33333034 DOI: 10.1016/j.bpj.2020.12.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 11/20/2020] [Accepted: 12/08/2020] [Indexed: 02/08/2023] Open
Abstract
Distinct missense mutations in a specific gene have been associated with different diseases as well as differing severity of a disease. Current computational methods predict the potential pathogenicity of a missense variant but fail to differentiate between separate disease or severity phenotypes. We have developed a method to overcome this limitation by applying machine learning to features extracted from molecular dynamics simulations, creating a way to predict the effect of novel genetic variants in causing a disease, drug resistance, or another specific trait. As an example, we have applied this novel approach to variants in calmodulin associated with two distinct arrhythmias as well as two different neurodegenerative diseases caused by variants in amyloid-β peptide. The new method successfully predicts the specific disease caused by a gene variant and ranks its severity with more accuracy than existing methods. We call this method molecular dynamics phenotype prediction model.
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Affiliation(s)
- Matthew D McCoy
- Innovation Center for Biomedical Informatics, Department of Oncology, Georgetown University Medical Center, Georgetown University, Washington DC; School of Systems Biology, George Mason University, Manassas, Virginia.
| | - John Hamre
- School of Systems Biology, George Mason University, Manassas, Virginia
| | - Dmitri K Klimov
- School of Systems Biology, George Mason University, Manassas, Virginia
| | - M Saleet Jafri
- School of Systems Biology, George Mason University, Manassas, Virginia; Krasnow Institute for Advanced Study, Interdisciplinary Program in Neuroscience, School of Systems Biology, George Mason University, Fairfax, Virginia.
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16
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Crotti L, Spazzolini C, Tester DJ, Ghidoni A, Baruteau AE, Beckmann BM, Behr ER, Bennett JS, Bezzina CR, Bhuiyan ZA, Celiker A, Cerrone M, Dagradi F, De Ferrari GM, Etheridge SP, Fatah M, Garcia-Pavia P, Al-Ghamdi S, Hamilton RM, Al-Hassnan ZN, Horie M, Jimenez-Jaimez J, Kanter RJ, Kaski JP, Kotta MC, Lahrouchi N, Makita N, Norrish G, Odland HH, Ohno S, Papagiannis J, Parati G, Sekarski N, Tveten K, Vatta M, Webster G, Wilde AAM, Wojciak J, George AL, Ackerman MJ, Schwartz PJ. Calmodulin mutations and life-threatening cardiac arrhythmias: insights from the International Calmodulinopathy Registry. Eur Heart J 2020; 40:2964-2975. [PMID: 31170290 DOI: 10.1093/eurheartj/ehz311] [Citation(s) in RCA: 103] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 02/06/2019] [Accepted: 04/29/2019] [Indexed: 12/12/2022] Open
Abstract
AIMS Calmodulinopathies are rare life-threatening arrhythmia syndromes which affect mostly young individuals and are, caused by mutations in any of the three genes (CALM 1-3) that encode identical calmodulin proteins. We established the International Calmodulinopathy Registry (ICalmR) to understand the natural history, clinical features, and response to therapy of patients with a CALM-mediated arrhythmia syndrome. METHODS AND RESULTS A dedicated Case Report File was created to collect demographic, clinical, and genetic information. ICalmR has enrolled 74 subjects, with a variant in the CALM1 (n = 36), CALM2 (n = 23), or CALM3 (n = 15) genes. Sixty-four (86.5%) were symptomatic and the 10-year cumulative mortality was 27%. The two prevalent phenotypes are long QT syndrome (LQTS; CALM-LQTS, n = 36, 49%) and catecholaminergic polymorphic ventricular tachycardia (CPVT; CALM-CPVT, n = 21, 28%). CALM-LQTS patients have extremely prolonged QTc intervals (594 ± 73 ms), high prevalence (78%) of life-threatening arrhythmias with median age at onset of 1.5 years [interquartile range (IQR) 0.1-5.5 years] and poor response to therapies. Most electrocardiograms (ECGs) show late onset peaked T waves. All CALM-CPVT patients were symptomatic with median age of onset of 6.0 years (IQR 3.0-8.5 years). Basal ECG frequently shows prominent U waves. Other CALM-related phenotypes are idiopathic ventricular fibrillation (IVF, n = 7), sudden unexplained death (SUD, n = 4), overlapping features of CPVT/LQTS (n = 3), and predominant neurological phenotype (n = 1). Cardiac structural abnormalities and neurological features were present in 18 and 13 patients, respectively. CONCLUSION Calmodulinopathies are largely characterized by adrenergically-induced life-threatening arrhythmias. Available therapies are disquietingly insufficient, especially in CALM-LQTS. Combination therapy with drugs, sympathectomy, and devices should be considered.
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Affiliation(s)
- Lia Crotti
- Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin, Milan, Italy.,Istituto Auxologico Italiano, IRCCS, Laboratory of Cardiovascular Genetics, Milan, Italy.,Istituto Auxologico Italiano, IRCCS, Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy.,Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy.,Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart
| | - Carla Spazzolini
- Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin, Milan, Italy.,Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart
| | - David J Tester
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA.,Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN, USA.,Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic, Rochester, MN, USA
| | - Alice Ghidoni
- Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin, Milan, Italy.,Istituto Auxologico Italiano, IRCCS, Laboratory of Cardiovascular Genetics, Milan, Italy.,Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart
| | - Alban-Elouen Baruteau
- Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart.,L'Institut du Thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France.,Cardiology Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK
| | - Britt-Maria Beckmann
- Department of Medicine I, Klinikum Grosshadern, Ludwig-Maximilians University, Munich, Germany
| | - Elijah R Behr
- Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart.,Cardiology Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St George's University of London, London, UK
| | | | - Connie R Bezzina
- Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart.,Amsterdam UMC, University of Amsterdam, Heart Center; Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Zahurul A Bhuiyan
- Unité de Recherche Cardiogénétique, Service de Médecine Génétique, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Alpay Celiker
- Department of Pediatric Cardiology, Koc University School of Medicine, Istanbul, Turkey
| | - Marina Cerrone
- Cardiovascular Genetics Program, Leon H. Charney Division of Cardiology, New York University School of Medicine, New York, NY, USA
| | - Federica Dagradi
- Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin, Milan, Italy.,Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart
| | - Gaetano M De Ferrari
- Division of Cardiology, "Città della Salute e della Scienza di Torino" Hospital, Department of Medical Sciences, University of Turin, Italy.,PhD Program in Translational Medicine, Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Susan P Etheridge
- Division of Pediatric Cardiology, Department of Pediatrics, University of Utah and Primary Children's Hospital, Salt Lake City, UT, USA
| | - Meena Fatah
- The Labatt Family Heart Centre and Pediatrics (Cardiology), The Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada
| | - Pablo Garcia-Pavia
- Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart.,Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de Hierro, CIBERCV, Madrid, Spain.,University Francisco de Vitoria (UFV), Pozuelo de Alarcon, Spain
| | - Saleh Al-Ghamdi
- Cardiac Sciences Department, Section of Pediatric Cardiology, King Abdulaziz Cardiac Center, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Robert M Hamilton
- The Labatt Family Heart Centre and Pediatrics (Cardiology), The Hospital for Sick Children and University of Toronto, Toronto, Ontario, Canada
| | - Zuhair N Al-Hassnan
- Cardiovascular Genetic Program, Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan
| | - Juan Jimenez-Jaimez
- Cardiology Department, Virgen de las Nieves University Hospital, Granada, Spain
| | | | - Juan P Kaski
- Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart.,Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, UK.,Institute of Cardiovascular Science, University College London, London, UK
| | - Maria-Christina Kotta
- Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin, Milan, Italy.,Istituto Auxologico Italiano, IRCCS, Laboratory of Cardiovascular Genetics, Milan, Italy.,Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart
| | - Najim Lahrouchi
- Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart.,Amsterdam UMC, University of Amsterdam, Heart Center; Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Naomasa Makita
- National Cerebral and Cardiovascular Center, Research Institute and Omics Research Center, Osaka, Japan
| | - Gabrielle Norrish
- Centre for Inherited Cardiovascular Diseases, Great Ormond Street Hospital, London, UK.,Institute of Cardiovascular Science, University College London, London, UK
| | - Hans H Odland
- Department of Pediatric Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Seiko Ohno
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan.,Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - John Papagiannis
- Division of Cardiology, Children's Mercy Hospital, Kansas City, MO, USA
| | - Gianfranco Parati
- Istituto Auxologico Italiano, IRCCS, Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy.,Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
| | - Nicole Sekarski
- Paediatric Cardiology Unit, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Kristian Tveten
- Department of Medical Genetics, Telemark Hospital Trust, Skien, Norway
| | - Matteo Vatta
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.,Invitae Corporation, San Francisco, CA, USA
| | - Gregory Webster
- Division of Cardiology, Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Arthur A M Wilde
- Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart.,Amsterdam UMC, University of Amsterdam, Heart Center; Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Julianne Wojciak
- Department of Genomic Medicine, University of California San Francisco (UCSF), San Francisco, CA, USA
| | - Alfred L George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Michael J Ackerman
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Peter J Schwartz
- Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin, Milan, Italy.,Istituto Auxologico Italiano, IRCCS, Laboratory of Cardiovascular Genetics, Milan, Italy.,Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart-ERN GUARD-Heart
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17
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Abrams J, Roybal D, Chakouri N, Katchman AN, Weinberg R, Yang L, Chen BX, Zakharov SI, Hennessey JA, Avula UMR, Diaz J, Wang C, Wan EY, Pitt GS, Ben-Johny M, Marx SO. Fibroblast growth factor homologous factors tune arrhythmogenic late NaV1.5 current in calmodulin binding-deficient channels. JCI Insight 2020; 5:141736. [PMID: 32870823 PMCID: PMC7566708 DOI: 10.1172/jci.insight.141736] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 08/26/2020] [Indexed: 12/19/2022] Open
Abstract
The Ca2+-binding protein calmodulin has emerged as a pivotal player in tuning Na+ channel function, although its impact in vivo remains to be resolved. Here, we identify the role of calmodulin and the NaV1.5 interactome in regulating late Na+ current in cardiomyocytes. We created transgenic mice with cardiac-specific expression of human NaV1.5 channels with alanine substitutions for the IQ motif (IQ/AA). The mutations rendered the channels incapable of binding calmodulin to the C-terminus. The IQ/AA transgenic mice exhibited normal ventricular repolarization without arrhythmias and an absence of increased late Na+ current. In comparison, transgenic mice expressing a lidocaine-resistant (F1759A) human NaV1.5 demonstrated increased late Na+ current and prolonged repolarization in cardiomyocytes, with spontaneous arrhythmias. To determine regulatory factors that prevent late Na+ current for the IQ/AA mutant channel, we considered fibroblast growth factor homologous factors (FHFs), which are within the NaV1.5 proteomic subdomain shown by proximity labeling in transgenic mice expressing NaV1.5 conjugated to ascorbate peroxidase. We found that FGF13 diminished late current of the IQ/AA but not F1759A mutant cardiomyocytes, suggesting that endogenous FHFs may serve to prevent late Na+ current in mouse cardiomyocytes. Leveraging endogenous mechanisms may furnish an alternative avenue for developing novel pharmacology that selectively blunts late Na+ current.
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Affiliation(s)
| | | | - Nourdine Chakouri
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | | | | | - Lin Yang
- Division of Cardiology, Department of Medicine
| | | | | | | | | | - Johanna Diaz
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Chaojian Wang
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | | | - Geoffrey S. Pitt
- Cardiovascular Research Institute, Weill Cornell Medical College, New York, New York, USA
| | - Manu Ben-Johny
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Steven O. Marx
- Division of Cardiology, Department of Medicine
- Department of Pharmacology, and
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18
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Tsai WC, Guo S, Olaopa MA, Field LJ, Yang J, Shen C, Chang CP, Chen PS, Rubart M. Complex Arrhythmia Syndrome in a Knock-In Mouse Model Carrier of the N98S Calm1 Mutation. Circulation 2020; 142:1937-1955. [PMID: 32929985 DOI: 10.1161/circulationaha.120.046450] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Calmodulin mutations are associated with arrhythmia syndromes in humans. Exome sequencing previously identified a de novo mutation in CALM1 resulting in a p.N98S substitution in a patient with sinus bradycardia and stress-induced bidirectional ventricular ectopy. The objectives of the present study were to determine if mice carrying the N98S mutation knocked into Calm1 replicate the human arrhythmia phenotype and to examine arrhythmia mechanisms. METHODS Mouse lines heterozygous for the Calm1N98S allele (Calm1N98S/+) were generated using CRISPR/Cas9 technology. Adult mutant mice and their wildtype littermates (Calm1+/+) underwent electrocardiographic monitoring. Ventricular de- and repolarization was assessed in isolated hearts using optical voltage mapping. Action potentials and whole-cell currents and [Ca2+]i, as well, were measured in single ventricular myocytes using the patch-clamp technique and fluorescence microscopy, respectively. The microelectrode technique was used for in situ membrane voltage monitoring of ventricular conduction fibers. RESULTS Two biologically independent knock-in mouse lines heterozygous for the Calm1N98S allele were generated. Calm1N98S/+ mice of either sex and line exhibited sinus bradycardia, QTc interval prolongation, and catecholaminergic bidirectional ventricular tachycardia. Male mutant mice also showed QRS widening. Pharmacological blockade and activation of β-adrenergic receptors rescued and exacerbated, respectively, the long-QT phenotype of Calm1N98S/+ mice. Optical and electric assessment of membrane potential in isolated hearts and single left ventricular myocytes, respectively, revealed β-adrenergically induced delay of repolarization. β-Adrenergic stimulation increased peak density, slowed inactivation, and left-shifted the activation curve of ICa.L significantly more in Calm1N98S/+ versus Calm1+/+ ventricular myocytes, increasing late ICa.L in the former. Rapidly paced Calm1N98S/+ ventricular myocytes showed increased propensity to delayed afterdepolarization-induced triggered activity, whereas in situ His-Purkinje fibers exhibited increased susceptibility for pause-dependent early afterdepolarizations. Epicardial mapping of Calm1N98S/+ hearts showed that both reentry and focal mechanisms contribute to arrhythmogenesis. CONCLUSIONS Heterozygosity for the Calm1N98S mutation is causative of an arrhythmia syndrome characterized by sinus bradycardia, QRS widening, adrenergically mediated QTc interval prolongation, and bidirectional ventricular tachycardia. β-Adrenergically induced ICa.L dysregulation contributes to the long-QT phenotype. Pause-dependent early afterdepolarizations and tachycardia-induced delayed afterdepolarizations originating in the His-Purkinje network and ventricular myocytes, respectively, constitute potential sources of arrhythmia in Calm1N98S/+ hearts.
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Affiliation(s)
- Wen-Chin Tsai
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine (W.-C.T., S.G., M.A.O., J.Y., C.-P.C. P.-S.C., M.R.), Indiana University School of Medicine, Indianapolis.,Department of Cardiology, Cardiovascular Research Center, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan (W.-C.T.)
| | - Shuai Guo
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine (W.-C.T., S.G., M.A.O., J.Y., C.-P.C. P.-S.C., M.R.), Indiana University School of Medicine, Indianapolis.,Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, Harbin, China (S.G.)
| | - Michael A Olaopa
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine (W.-C.T., S.G., M.A.O., J.Y., C.-P.C. P.-S.C., M.R.), Indiana University School of Medicine, Indianapolis
| | - Loren J Field
- Wells Center for Pediatric Research, Department of Pediatrics (L.J.F., M.R.), Indiana University School of Medicine, Indianapolis
| | - Jin Yang
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine (W.-C.T., S.G., M.A.O., J.Y., C.-P.C. P.-S.C., M.R.), Indiana University School of Medicine, Indianapolis
| | - Changyu Shen
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (C.S.)
| | - Ching-Pin Chang
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine (W.-C.T., S.G., M.A.O., J.Y., C.-P.C. P.-S.C., M.R.), Indiana University School of Medicine, Indianapolis
| | - Peng-Sheng Chen
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine (W.-C.T., S.G., M.A.O., J.Y., C.-P.C. P.-S.C., M.R.), Indiana University School of Medicine, Indianapolis
| | - Michael Rubart
- The Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine (W.-C.T., S.G., M.A.O., J.Y., C.-P.C. P.-S.C., M.R.), Indiana University School of Medicine, Indianapolis.,Wells Center for Pediatric Research, Department of Pediatrics (L.J.F., M.R.), Indiana University School of Medicine, Indianapolis
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19
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Saljic A, Muthukumarasamy KM, la Cour JM, Boddum K, Grunnet M, Berchtold MW, Jespersen T. Impact of arrhythmogenic calmodulin variants on small conductance Ca 2+ -activated K + (SK3) channels. Physiol Rep 2020; 7:e14210. [PMID: 31587513 PMCID: PMC6778599 DOI: 10.14814/phy2.14210] [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: 07/26/2019] [Accepted: 07/31/2019] [Indexed: 02/07/2023] Open
Abstract
Calmodulin (CaM) is a ubiquitous Ca2+‐sensing protein regulating many important cellular processes. Several CaM‐associated variants have been identified in a small group of patients with cardiac arrhythmias. The mechanism remains largely unknown, even though a number of ion channels, including the ryanodine receptors and the L‐type calcium channels have been shown to be functionally affected by the presence of mutant CaM. CaM is constitutively bound to the SK channel, which underlies the calcium‐gated ISK contributing to cardiac repolarization. The CaM binding to SK channels is essential for gating, correct assembly, and membrane expression. To elucidate the effect of nine different arrhythmogenic CaM variants on SK3 channel function, HEK293 cells stably expressing SK3 were transiently co‐transfected with CaMWT or variant and whole‐cell patch‐clamp recordings were performed with a calculated free Ca2+ concentration of 400 nmol/L. MDCK cells were transiently transfected with SK3 and/or CaMWT or variant to address SK3 and CaM localization by immunocytochemistry. The LQTS‐associated variants CaMD96V, CaMD130G, and CaMF142L reduced ISK,Ca compared with CaMWT (P < 0.01, P < 0.001, and P < 0.05, respectively). The CPVT associated variant CaMN54I also reduced the ISK,Ca (P < 0.05), which was linked to an accumulation of SK3/CaMN54I channel complexes in intracellular compartments (P < 0.05). The CPVT associated variants, CaMA103V and CaMD132E only revealed a tendency toward reduced current, while the variants CaMF90L and CaMN98S, causing LQTS syndrome, did not have any impact on ISK,Ca. In conclusion, we found that the arrhythmogenic CaM variants CaMN54I, CaMD96V, CaMD130G, and CaMF142L significantly down‐regulate the SK3 channel current, but with distinct mechanism.
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Affiliation(s)
- Arnela Saljic
- Laboratory of Cardiac Physiology, Faculty of Health and Medical Sciences, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kalai Mangai Muthukumarasamy
- Laboratory of Cardiac Physiology, Faculty of Health and Medical Sciences, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jonas Marstrand la Cour
- Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Kim Boddum
- Laboratory of Cardiac Physiology, Faculty of Health and Medical Sciences, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Martin Werner Berchtold
- Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Jespersen
- Laboratory of Cardiac Physiology, Faculty of Health and Medical Sciences, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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20
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Llongueras JP, Das S, De Waele J, Capulzini L, Sorgente A, Van Petegem F, Bosmans F. Biophysical Investigation of Sodium Channel Interaction with β-Subunit Variants Associated with Arrhythmias. Bioelectricity 2020; 2:269-278. [PMID: 34476357 DOI: 10.1089/bioe.2020.0030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background: Voltage-gated sodium (NaV) channels help regulate electrical activity of the plasma membrane. Mutations in associated subunits can result in pathological outcomes. Here we examined the interaction of NaV channels with cardiac arrhythmia-linked mutations in SCN2B and SCN4B, two genes that encode auxiliary β-subunits. Materials and Methods: To investigate changes in SCN2B R137H and SCN4B I80T function, we combined three-dimensional X-ray crystallography with electrophysiological measurements on NaV1.5, the dominant subtype in the heart. Results: SCN4B I80T alters channel activity, whereas SCN2B R137H does not have an apparent effect. Structurally, the SCN4B I80T perturbation alters hydrophobic packing of the subunit with major structural changes and causes a thermal destabilization of the folding. In contrast, SCN2B R137H leads to structural changes but overall protein stability is unaffected. Conclusion: SCN4B I80T data suggest a functionally important region in the interaction between NaV1.5 and β4 that, when disrupted, could lead to channel dysfunction. A lack of apparent functional effects of SCN2B R137H on NaV1.5 suggests an alternative working mechanism, possibly through other NaV channel subtypes present in heart tissue. Indeed, mapping the structural variations of SCN2B R137H onto neuronal NaV channel structures suggests altered interaction patterns.
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Affiliation(s)
- José P Llongueras
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Samir Das
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada.,Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Jolien De Waele
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Lucio Capulzini
- Arrhythmia and Electrophysiology Center, Department of Cardiology, Epicura Hospitalier Center, Hornu, Belgium
| | - Antonio Sorgente
- Arrhythmia and Electrophysiology Center, Department of Cardiology, Epicura Hospitalier Center, Hornu, Belgium
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada.,Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Frank Bosmans
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
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21
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Wleklinski MJ, Kannankeril PJ, Knollmann BC. Molecular and tissue mechanisms of catecholaminergic polymorphic ventricular tachycardia. J Physiol 2020; 598:2817-2834. [PMID: 32115705 PMCID: PMC7699301 DOI: 10.1113/jp276757] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/03/2020] [Indexed: 12/21/2022] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a stress-induced cardiac channelopathy that has a high mortality in untreated patients. Our understanding has grown tremendously since CPVT was first described as a clinical syndrome in 1995. It is now established that the deadly arrhythmias are caused by unregulated 'pathological' calcium release from the sarcoplasmic reticulum (SR), the major calcium storage organelle in striated muscle. Important questions remain regarding the molecular mechanisms that are responsible for the pathological calcium release, regarding the tissue origin of the arrhythmic beats that initiate ventricular tachycardia, and regarding optimal therapeutic approaches. At present, mutations in six genes involved in SR calcium release have been identified as the genetic cause of CPVT: RYR2 (encoding ryanodine receptor calcium release channel), CASQ2 (encoding cardiac calsequestrin), TRDN (encoding triadin), CALM1, CALM2 and CALM3 (encoding identical calmodulin protein). Here, we review each CPVT subtype and how CPVT mutations alter protein function, RyR2 calcium release channel regulation, and cellular calcium handling. We then discuss research and hypotheses surrounding the tissue mechanisms underlying CPVT, such as the pathophysiological role of sinus node dysfunction in CPVT, and whether the arrhythmogenic beats originate from the conduction system or the ventricular working myocardium. Finally, we review the treatments that are available for patients with CPVT, their efficacy, and how therapy could be improved in the future.
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Affiliation(s)
- Matthew J Wleklinski
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Prince J Kannankeril
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Bjӧrn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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22
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Sigalas C, Cremer M, Winbo A, Bose SJ, Ashton JL, Bub G, Montgomery JM, Burton RAB. Combining tissue engineering and optical imaging approaches to explore interactions along the neuro-cardiac axis. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200265. [PMID: 32742694 PMCID: PMC7353978 DOI: 10.1098/rsos.200265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 05/27/2020] [Indexed: 05/05/2023]
Abstract
Interactions along the neuro-cardiac axis are being explored with regard to their involvement in cardiac diseases, including catecholaminergic polymorphic ventricular tachycardia, hypertension, atrial fibrillation, long QT syndrome and sudden death in epilepsy. Interrogation of the pathophysiology and pathogenesis of neuro-cardiac diseases in animal models present challenges resulting from species differences, phenotypic variation, developmental effects and limited availability of data relevant at both the tissue and cellular level. By contrast, tissue-engineered models containing cardiomyocytes and peripheral sympathetic and parasympathetic neurons afford characterization of cellular- and tissue-level behaviours while maintaining precise control over developmental conditions, cellular genotype and phenotype. Such approaches are uniquely suited to long-term, high-throughput characterization using optical recording techniques with the potential for increased translational benefit compared to more established techniques. Furthermore, tissue-engineered constructs provide an intermediary between whole animal/tissue experiments and in silico models. This paper reviews the advantages of tissue engineering methods of multiple cell types and optical imaging techniques for the characterization of neuro-cardiac diseases.
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Affiliation(s)
| | - Maegan Cremer
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Annika Winbo
- Department of Physiology, University of Auckland, Auckland, New Zealand
- Department of Paediatric and Congenital Cardiac Services, Starship Children's Hospital, Auckland, New Zealand
| | - Samuel J. Bose
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Jesse L. Ashton
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Gil Bub
- Department of Physiology, McGill University, Montreal, Canada
| | | | - Rebecca A. B. Burton
- Department of Pharmacology, University of Oxford, Oxford, UK
- Author for correspondence: Rebecca A. B. Burton e-mail:
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23
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Holt C, Hamborg L, Lau K, Brohus M, Sørensen AB, Larsen KT, Sommer C, Van Petegem F, Overgaard MT, Wimmer R. The arrhythmogenic N53I variant subtly changes the structure and dynamics in the calmodulin N-terminal domain, altering its interaction with the cardiac ryanodine receptor. J Biol Chem 2020; 295:7620-7634. [PMID: 32317284 DOI: 10.1074/jbc.ra120.013430] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/18/2020] [Indexed: 12/11/2022] Open
Abstract
Mutations in the genes encoding the highly conserved Ca2+-sensing protein calmodulin (CaM) cause severe cardiac arrhythmias, including catecholaminergic polymorphic ventricular tachycardia or long QT syndrome and sudden cardiac death. Most of the identified arrhythmogenic mutations reside in the C-terminal domain of CaM and mostly affect Ca2+-coordinating residues. One exception is the catecholaminergic polymorphic ventricular tachycardia-causing N53I substitution, which resides in the N-terminal domain (N-domain). It does not affect Ca2+ coordination and has only a minor impact on binding affinity toward Ca2+ and on other biophysical properties. Nevertheless, the N53I substitution dramatically affects CaM's ability to reduce the open probability of the cardiac ryanodine receptor (RyR2) while having no effect on the regulation of the plasmalemmal voltage-gated Ca2+ channel, Cav1.2. To gain more insight into the molecular disease mechanism of this mutant, we used NMR to investigate the structures and dynamics of both apo- and Ca2+-bound CaM-N53I in solution. We also solved the crystal structures of WT and N53I CaM in complex with the primary calmodulin-binding domain (CaMBD2) from RyR2 at 1.84-2.13 Å resolutions. We found that all structures of the arrhythmogenic CaM-N53I variant are highly similar to those of WT CaM. However, we noted that the N53I substitution exposes an additional hydrophobic surface and that the intramolecular dynamics of the protein are significantly altered such that they destabilize the CaM N-domain. We conclude that the N53I-induced changes alter the interaction of the CaM N-domain with RyR2 and thereby likely cause the arrhythmogenic phenotype of this mutation.
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Affiliation(s)
- Christian Holt
- Aalborg University, Department of Chemistry and Bioscience, 9220 Aalborg, Denmark
| | - Louise Hamborg
- Aalborg University, Department of Chemistry and Bioscience, 9220 Aalborg, Denmark
| | - Kelvin Lau
- University of British Columbia, Department of Biochemistry and Molecular Biology, V6T 1Z3 Vancouver, British Columbia, Canada
| | - Malene Brohus
- Aalborg University, Department of Chemistry and Bioscience, 9220 Aalborg, Denmark
| | | | | | - Cordula Sommer
- Aalborg University, Department of Chemistry and Bioscience, 9220 Aalborg, Denmark
| | - Filip Van Petegem
- University of British Columbia, Department of Biochemistry and Molecular Biology, V6T 1Z3 Vancouver, British Columbia, Canada
| | | | - Reinhard Wimmer
- Aalborg University, Department of Chemistry and Bioscience, 9220 Aalborg, Denmark
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24
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Wang K, Brohus M, Holt C, Overgaard MT, Wimmer R, Van Petegem F. Arrhythmia mutations in calmodulin can disrupt cooperativity of Ca 2+ binding and cause misfolding. J Physiol 2020; 598:1169-1186. [PMID: 32012279 DOI: 10.1113/jp279307] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 01/28/2020] [Indexed: 01/09/2023] Open
Abstract
KEY POINTS Mutations in the calmodulin protein (CaM) are associated with arrhythmia syndromes. This study focuses on understanding the structural characteristics of CaM disease mutants and their interactions with the voltage-gated calcium channel CaV 1.2. Arrhythmia mutations in CaM can lead to loss of Ca2+ binding, uncoupling of Ca2+ binding cooperativity, misfolding of the EF-hands and altered affinity for the calcium channel. These results help us to understand how different CaM mutants have distinct effects on structure and interactions with protein targets to cause disease. ABSTRACT Calmodulinopathies are life-threatening arrhythmia syndromes that arise from mutations in calmodulin (CaM), a calcium sensing protein whose sequence is completely conserved across all vertebrates. These mutations have been shown to interfere with the function of cardiac ion channels, including the voltage-gated Ca2+ channel CaV 1.2 and the ryanodine receptor (RyR2), in a mutation-specific manner. The ability of different CaM disease mutations to discriminate between these channels has been enigmatic. We present crystal structures of several C-terminal lobe mutants and an N-terminal lobe mutant in complex with the CaV 1.2 IQ domain, in conjunction with binding assays and complementary structural biology techniques. One mutation (D130G) causes a pathological conformation, with complete separation of EF-hands within the C-lobe and loss of Ca2+ binding in EF-hand 4. Another variant (Q136P) has severely reduced affinity for the IQ domain, and shows changes in the CD spectra under Ca2+ -saturating conditions when unbound to the IQ domain. Ca2+ binding to a pair of EF-hands normally proceeds with very high cooperativity, but we found that N98S CaM can adopt different conformations with either one or two Ca2+ ions bound to the C-lobe, possibly disrupting the cooperativity. An N-lobe variant (N54I), which causes severe stress-induced arrhythmia, does not show any major changes in complex with the IQ domain, providing a structural basis for why this mutant does not affect function of CaV 1.2. These findings show that different CaM mutants have distinct effects on both the CaM structure and interactions with protein targets, and act via distinct pathological mechanisms to cause disease.
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Affiliation(s)
- Kaiqian Wang
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, V6T 1Z3 Vancouver, BC, Canada
| | - Malene Brohus
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Christian Holt
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | | | - Reinhard Wimmer
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, V6T 1Z3 Vancouver, BC, Canada
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25
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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] [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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26
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Wren LM, Jiménez-Jáimez J, Al-Ghamdi S, Al-Aama JY, Bdeir A, Al-Hassnan ZN, Kuan JL, Foo RY, Potet F, Johnson CN, Aziz MC, Carvill GL, Kaski JP, Crotti L, Perin F, Monserrat L, Burridge PW, Schwartz PJ, Chazin WJ, Bhuiyan ZA, George AL. Genetic Mosaicism in Calmodulinopathy. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2019; 12:375-385. [PMID: 31454269 DOI: 10.1161/circgen.119.002581] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND CaM (calmodulin) mutations are associated with congenital arrhythmia susceptibility (calmodulinopathy) and are most often de novo. In this report, we sought to broaden the genotype-phenotype spectrum of calmodulinopathies with 2 novel calmodulin mutations and to investigate mosaicism in 2 affected families. METHODS CaM mutations were identified in 4 independent cases by DNA sequencing. Biochemical and electrophysiological studies were performed to determine functional consequences of each mutation. RESULTS Genetic studies identified 2 novel CaM variants (CALM3-E141K in 2 cases; CALM1-E141V) and one previously reported CaM pathogenic variant (CALM3-D130G) among 4 probands with shared clinical features of prolonged QTc interval (range 505-725 ms) and documented ventricular arrhythmia. A fatal outcome occurred for 2 of the cases. The parents of all probands were asymptomatic with normal QTc duration. However, 2 of the families had multiple affected offspring or multiple occurrences of intrauterine fetal demise. The mother from the family with recurrent intrauterine fetal demise exhibited the CALM3-E141K mutant allele in 25% of next-generation sequencing reads indicating somatic mosaicism, whereas CALM3-D130G was present in 6% of captured molecules of the paternal DNA sample, also indicating mosaicism. Two novel mutations (E141K and E141V) impaired Ca2+ binding affinity to the C-domain of CaM. Human-induced pluripotent stem cell-derived cardiomyocytes overexpressing mutant or wild-type CaM showed that both mutants impaired Ca2+-dependent inactivation of L-type Ca2+ channels and prolonged action potential duration. CONCLUSIONS We report 2 families with somatic mosaicism associated with arrhythmogenic calmodulinopathy, and demonstrate dysregulation of L-type Ca2+ channels by 2 novel CaM mutations affecting the same residue. Parental mosaicism should be suspected in families with unexplained fetal arrhythmia or fetal demise combined with a documented CaM mutation.
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Affiliation(s)
- Lisa M Wren
- From the Department of Pharmacology (L.M.W., F.P., P.W.B., A.L.G.), Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Juan Jiménez-Jáimez
- Cardiology Department (J.J.-J.), Virgen de las Nieves Hospital, Granada, Spain
| | - Saleh Al-Ghamdi
- Cardiac Sciences Department, Section of Pediatric Cardiology, King Abdulaziz Cardiac Center, Ministry of National Guard Health Affairs, Riyadh (S.A.-G.)
| | - Jumana Y Al-Aama
- Department of Genetic Medicine, Faculty of Medicine (J.Y.A.-A.), King Abdulaziz University, Jeddah.,Princess Al Jawhara Albrahim Center of Excellence in Research of Hereditary Disorders (J.Y.A.-A., A.B.), King Abdulaziz University, Jeddah
| | - Amnah Bdeir
- Princess Al Jawhara Albrahim Center of Excellence in Research of Hereditary Disorders (J.Y.A.-A., A.B.), King Abdulaziz University, Jeddah
| | - Zuhair N Al-Hassnan
- The Cardiovascular Genetics Program, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia (Z.N.A.-H.)
| | - Jyn L Kuan
- Department of Cardiology, National University Heart Center and Cardiovascular Research Institute, National University of Singapore (J.L.K., R.Y.F.)
| | - Roger Y Foo
- Department of Cardiology, National University Heart Center and Cardiovascular Research Institute, National University of Singapore (J.L.K., R.Y.F.)
| | - Franck Potet
- From the Department of Pharmacology (L.M.W., F.P., P.W.B., A.L.G.), Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Christopher N Johnson
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN (C.N.J., W.J.C.)
| | - Miriam C Aziz
- Department of Neurology (M.C.A., G.L.C.), Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Gemma L Carvill
- Department of Neurology (M.C.A., G.L.C.), Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Juan-Pablo Kaski
- Institute of Cardiovascular Science, University College London, United Kingdom (J.-P.K.)
| | - Lia Crotti
- Department of Medicine and Surgery, University of Milano-Bicocca (L.C.).,IRCCS Istituto Auxologico Italiano, Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Milan, Italy (L.C., P.J.S.).,Cardiology Department, Health in Code SL, A Coruña, Spain (L.M.)
| | - Francesca Perin
- Pediatric Cardiology Division (F.P.), Virgen de las Nieves Hospital, Granada, Spain
| | | | - Paul W Burridge
- From the Department of Pharmacology (L.M.W., F.P., P.W.B., A.L.G.), Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Peter J Schwartz
- IRCCS Istituto Auxologico Italiano, Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Milan, Italy (L.C., P.J.S.)
| | - Walter J Chazin
- Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN (C.N.J., W.J.C.)
| | - Zahurul A Bhuiyan
- Unité de Recherche Cardiogénétique, Service de Médecine Génétique, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland (Z.A.B.)
| | - Alfred L George
- From the Department of Pharmacology (L.M.W., F.P., P.W.B., A.L.G.), Northwestern University Feinberg School of Medicine, Chicago, IL
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27
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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: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [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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Gomez-Hurtado N, Blackwell DJ, Knollmann BC. Modelling human calmodulinopathies with induced pluripotent stem cells: progress and challenges. Cardiovasc Res 2019; 113:437-439. [PMID: 28384370 DOI: 10.1093/cvr/cvx041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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Crystal structures of Ca 2+-calmodulin bound to Na V C-terminal regions suggest role for EF-hand domain in binding and inactivation. Proc Natl Acad Sci U S A 2019; 116:10763-10772. [PMID: 31072926 DOI: 10.1073/pnas.1818618116] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Voltage-gated sodium (NaV) and calcium channels (CaV) form targets for calmodulin (CaM), which affects channel inactivation properties. A major interaction site for CaM resides in the C-terminal (CT) region, consisting of an IQ domain downstream of an EF-hand domain. We present a crystal structure of fully Ca2+-occupied CaM, bound to the CT of NaV1.5. The structure shows that the C-terminal lobe binds to a site ∼90° rotated relative to a previous site reported for an apoCaM complex with the NaV1.5 CT and for ternary complexes containing fibroblast growth factor homologous factors (FHF). We show that the binding of FHFs forces the EF-hand domain in a conformation that does not allow binding of the Ca2+-occupied C-lobe of CaM. These observations highlight the central role of the EF-hand domain in modulating the binding mode of CaM. The binding sites for Ca2+-free and Ca2+-occupied CaM contain targets for mutations linked to long-QT syndrome, a type of inherited arrhythmia. The related NaV1.4 channel has been shown to undergo Ca2+-dependent inactivation (CDI) akin to CaVs. We present a crystal structure of Ca2+/CaM bound to the NaV1.4 IQ domain, which shows a binding mode that would clash with the EF-hand domain. We postulate the relative reorientation of the EF-hand domain and the IQ domain as a possible conformational switch that underlies CDI.
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Burgoyne RD, Helassa N, McCue HV, Haynes LP. Calcium Sensors in Neuronal Function and Dysfunction. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a035154. [PMID: 30833454 DOI: 10.1101/cshperspect.a035154] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Calcium signaling in neurons as in other cell types can lead to varied changes in cellular function. Neuronal Ca2+ signaling processes have also become adapted to modulate the function of specific pathways over a wide variety of time domains and these can have effects on, for example, axon outgrowth, neuronal survival, and changes in synaptic strength. Ca2+ also plays a key role in synapses as the trigger for fast neurotransmitter release. Given its physiological importance, abnormalities in neuronal Ca2+ signaling potentially underlie many different neurological and neurodegenerative diseases. The mechanisms by which changes in intracellular Ca2+ concentration in neurons can bring about diverse responses is underpinned by the roles of ubiquitous or specialized neuronal Ca2+ sensors. It has been established that synaptotagmins have key functions in neurotransmitter release, and, in addition to calmodulin, other families of EF-hand-containing neuronal Ca2+ sensors, including the neuronal calcium sensor (NCS) and the calcium-binding protein (CaBP) families, play important physiological roles in neuronal Ca2+ signaling. It has become increasingly apparent that these various Ca2+ sensors may also be crucial for aspects of neuronal dysfunction and disease either indirectly or directly as a direct consequence of genetic variation or mutations. An understanding of the molecular basis for the regulation of the targets of the Ca2+ sensors and the physiological roles of each protein in identified neurons may contribute to future approaches to the development of treatments for a variety of human neuronal disorders.
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Affiliation(s)
- Robert D Burgoyne
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Nordine Helassa
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Hannah V McCue
- Centre for Genomic Research, University of Liverpool, Liverpool, United Kingdom
| | - Lee P Haynes
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
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31
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Da'as SI, Thanassoulas A, Calver BL, Beck K, Salem R, Saleh A, Kontogianni I, Al-Maraghi A, Nasrallah GK, Safieh-Garabedian B, Toft E, Nounesis G, Lai FA, Nomikos M. Arrhythmogenic calmodulin E105A mutation alters cardiac RyR2 regulation leading to cardiac dysfunction in zebrafish. Ann N Y Acad Sci 2019; 1448:19-29. [PMID: 30937913 DOI: 10.1111/nyas.14033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 01/03/2023]
Abstract
Calmodulin (CaM) is a universal calcium (Ca2+ )-binding messenger that regulates many vital cellular events. In cardiac muscle, CaM associates with ryanodine receptor 2 (RyR2) and regulates excitation-contraction coupling. Mutations in human genes CALM1, CALM2, and CALM3 have been associated with life-threatening heart disorders, such as long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia. A novel de novo LQTS-associated missense CaM mutation (E105A) was recently identified in a 6-year-old boy, who experienced an aborted first episode of cardiac arrest. Herein, we report the first molecular characterization of the CaM E105A mutation. Expression of the CaM E105A mutant in zebrafish embryos resulted in cardiac arrhythmia and increased heart rate, suggestive of ventricular tachycardia. In vitro biophysical and biochemical analysis revealed that E105A confers a deleterious effect on protein stability and a reduced Ca2+ -binding affinity due to loss of cooperativity. Finally, the CaM E105A mutation resulted in reduced CaM-RyR2 interaction and defective modulation of ryanodine binding. Our findings suggest that the CaM E105A mutation dysregulates normal cardiac function by a complex mechanism involving alterations in both CaM-Ca2+ and CaM-RyR2 interactions.
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Affiliation(s)
- Sahar I Da'as
- Translational Medicine, Sidra Medicine, Doha, Qatar.,College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | | | - Brian L Calver
- College of Biomedical and Life Sciences, Cardiff University, Cardiff, UK
| | - Konrad Beck
- College of Biomedical and Life Sciences, Cardiff University, Cardiff, UK
| | - Rola Salem
- College of Medicine, Member of QU Health, Qatar University, Doha, Qatar
| | - Alaaeldin Saleh
- College of Medicine, Member of QU Health, Qatar University, Doha, Qatar
| | - Iris Kontogianni
- National Center for Scientific Research "Demokritos,", Aghia Paraskevi, Greece
| | - Ali Al-Maraghi
- College of Medicine, Member of QU Health, Qatar University, Doha, Qatar
| | - Gheyath K Nasrallah
- Biomedical Research Center, Qatar University, Doha, Qatar.,Department of Biomedical Sciences, College of Health Science, Qatar University, Doha, Qatar
| | | | - Egon Toft
- College of Medicine, Member of QU Health, Qatar University, Doha, Qatar
| | - George Nounesis
- National Center for Scientific Research "Demokritos,", Aghia Paraskevi, Greece
| | - F Anthony Lai
- College of Biomedical and Life Sciences, Cardiff University, Cardiff, UK.,College of Medicine, Member of QU Health, Qatar University, Doha, Qatar.,Biomedical Research Center, Qatar University, Doha, Qatar
| | - Michail Nomikos
- College of Medicine, Member of QU Health, Qatar University, Doha, Qatar
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Tyan L, Foell JD, Vincent KP, Woon MT, Mesquitta WT, Lang D, Best JM, Ackerman MJ, McCulloch AD, Glukhov AV, Balijepalli RC, Kamp TJ. Long QT syndrome caveolin-3 mutations differentially modulate K v 4 and Ca v 1.2 channels to contribute to action potential prolongation. J Physiol 2019; 597:1531-1551. [PMID: 30588629 DOI: 10.1113/jp276014] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 12/14/2018] [Indexed: 01/09/2023] Open
Abstract
KEY POINTS Mutations in the caveolae scaffolding protein, caveolin-3 (Cav3), have been linked to the long QT type 9 inherited arrhythmia syndrome (LQT9) and the cause of underlying action potential duration prolongation is incompletely understood. In the present study, we show that LQT9 Cav3 mutations, F97C and S141R, cause mutation-specific gain of function effects on Cav 1.2-encoded L-type Ca2+ channels responsible for ICa,L and also cause loss of function effects on heterologously expressed Kv 4.2 and Kv 4.3 channels responsible for Ito . A computational model of the human ventricular myocyte action potential suggests that the major ionic current change causing action potential duration prolongation in the presence of Cav3-F97C is the slowly inactivating ICa,L but, for Cav3-S141R, both increased ICa,L and increased late Na+ current contribute equally to action potential duration prolongation. Overall, the LQT9 Cav3-F97C and Cav3-S141R mutations differentially impact multiple ionic currents, highlighting the complexity of Cav3 regulation of cardiac excitability and suggesting mutation-specific therapeutic approaches. ABSTRACT Mutations in the CAV3 gene encoding caveolin-3 (Cav3), a scaffolding protein integral to caveolae in cardiomyocytes, have been associated with the congenital long-QT syndrome (LQT9). Initial studies demonstrated that LQT9-associated Cav3 mutations, F97C and S141R, increase late sodium current as a potential mechanism to prolong action potential duration (APD) and cause LQT9. Whether these Cav3 LQT9 mutations impact other caveolae related ion channels remains unknown. We used the whole-cell, patch clamp technique to characterize the effect of Cav3-F97C and Cav3-S141R mutations on heterologously expressed Cav 1.2+Cav β2cN4 channels, as well as Kv 4.2 and Kv 4.3 channels, in HEK 293 cells. Expression of Cav3-S141R increased ICa,L density without changes in gating properties, whereas expression of Cav3-F97C reduced Ca2+ -dependent inactivation of ICa,L without changing current density. The Cav3-F97C mutation reduced current density and altered the kinetics of IKv4.2 and IKv4.3 and also slowed recovery from inactivation. Cav3-S141R decreased current density and also slowed activation kinetics and recovery from inactivation of IKv4.2 but had no effect on IKv4.3 . Using the O'Hara-Rudy computational model of the human ventricular myocyte action potential, the Cav3 mutation-induced changes in Ito are predicted to have negligible effect on APD, whereas blunted Ca2+ -dependent inactivation of ICa,L by Cav3-F97C is predicted to be primarily responsible for APD prolongation, although increased ICa,L and late INa by Cav3-S141R contribute equally to APD prolongation. Thus, LQT9 Cav3-associated mutations, F97C and S141R, produce mutation-specific changes in multiple ionic currents leading to different primary causes of APD prolongation, which suggests the use of mutation-specific therapeutic approaches in the future.
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Affiliation(s)
- Leonid Tyan
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Jason D Foell
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Kevin P Vincent
- Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Marites T Woon
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Walatta T Mesquitta
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Di Lang
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Jabe M Best
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Michael J Ackerman
- Departments of Cardiovascular Medicine, Pediatric and Adolescent Medicine and Molecular Pharmacology & Experimental Therapeutics, Divisions of Heart Rhythm Services and Pediatric Cardiology, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Andrew D McCulloch
- Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, USA.,Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Alexey V Glukhov
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Ravi C Balijepalli
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Timothy J Kamp
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
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Crotti L, Ghidoni A, Dagradi F. Genetics of Adult and Fetal Forms of Long QT Syndrome. GENETIC CAUSES OF CARDIAC DISEASE 2019. [DOI: 10.1007/978-3-030-27371-2_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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35
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The multifunctional role of phospho-calmodulin in pathophysiological processes. Biochem J 2018; 475:4011-4023. [PMID: 30578290 PMCID: PMC6305829 DOI: 10.1042/bcj20180755] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 11/23/2018] [Accepted: 11/30/2018] [Indexed: 02/06/2023]
Abstract
Calmodulin (CaM) is a versatile Ca2+-sensor/transducer protein that modulates hundreds of enzymes, channels, transport systems, transcription factors, adaptors and other structural proteins, controlling in this manner multiple cellular functions. In addition to its capacity to regulate target proteins in a Ca2+-dependent and Ca2+-independent manner, the posttranslational phosphorylation of CaM by diverse Ser/Thr- and Tyr-protein kinases has been recognized as an important additional manner to regulate this protein by fine-tuning its functionality. In this review, we shall cover developments done in recent years in which phospho-CaM has been implicated in signalling pathways that are relevant for the onset and progression of diverse pathophysiological processes. These include diverse systems playing a major role in carcinogenesis and tumour development, prion-induced encephalopathies and brain hypoxia, melatonin-regulated neuroendocrine disorders, hypertension, and heavy metal-induced cell toxicity.
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36
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Kotta MC, Sala L, Ghidoni A, Badone B, Ronchi C, Parati G, Zaza A, Crotti L. Calmodulinopathy: A Novel, Life-Threatening Clinical Entity Affecting the Young. Front Cardiovasc Med 2018; 5:175. [PMID: 30574507 PMCID: PMC6291462 DOI: 10.3389/fcvm.2018.00175] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/22/2018] [Indexed: 01/31/2023] Open
Abstract
Sudden cardiac death (SCD) in the young may often be the first manifestation of a genetic arrythmogenic disease that had remained undiagnosed. Despite the significant discoveries of the genetic bases of inherited arrhythmia syndromes, there remains a measurable fraction of cases where in-depth clinical and genetic investigations fail to identify the underlying SCD etiology. A few years ago, 2 cases of infants with recurrent cardiac arrest episodes, due to what appeared to be as a severe form of long QT syndrome (LQTS), came to our attention. These prompted a number of clinical and genetic research investigations that allowed us to identify a novel, closely associated to LQTS but nevertheless distinct, clinical entity that is now known as calmodulinopathy. Calmodulinopathy is a life-threatening arrhythmia syndrome, affecting mostly young individuals, caused by mutations in any of the 3 genes encoding calmodulin (CaM). Calmodulin is a ubiquitously expressed Ca2+ signaling protein that, in the heart, modulates several ion channels and participates in a plethora of cellular processes. We will hereby provide an overview of CaM's structure and function under normal and disease states, highlighting the genetic etiology of calmodulinopathy and the related disease mechanisms. We will also discuss the phenotypic spectrum of patients with calmodulinopathy and present state-of-the art approaches with patient-derived induced pluripotent stem cells that have been thus far adopted in order to accurately model calmodulinopathy in vitro, decipher disease mechanisms and identify novel therapies.
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Affiliation(s)
- Maria-Christina Kotta
- Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Milan, Italy
| | - Luca Sala
- Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Milan, Italy
| | - Alice Ghidoni
- Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Milan, Italy
| | - Beatrice Badone
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Carlotta Ronchi
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Gianfranco Parati
- Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy.,Istituto Auxologico Italiano, IRCCS, Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy
| | - Antonio Zaza
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Lia Crotti
- Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Milan, Italy.,Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy.,Istituto Auxologico Italiano, IRCCS, Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy
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Limpitikul WB, Greenstein JL, Yue DT, Dick IE, Winslow RL. A bilobal model of Ca 2+-dependent inactivation to probe the physiology of L-type Ca 2+ channels. J Gen Physiol 2018; 150:1688-1701. [PMID: 30470716 PMCID: PMC6279366 DOI: 10.1085/jgp.201812115] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 08/01/2018] [Accepted: 10/26/2018] [Indexed: 12/20/2022] Open
Abstract
L-type calcium channels undergo Ca2+-dependent inactivation (CDI) in order to precisely control the entry of Ca2+ into cells such as cardiomyocytes. Limpitikul et al. develop a bilobal model of CDI and use it to understand the pathogenesis of arrhythmias associated with mutations in CaM. L-type calcium channels (LTCCs) are critical elements of normal cardiac function, playing a major role in orchestrating cardiac electrical activity and initiating downstream signaling processes. LTCCs thus use feedback mechanisms to precisely control calcium (Ca2+) entry into cells. Of these, Ca2+-dependent inactivation (CDI) is significant because it shapes cardiac action potential duration and is essential for normal cardiac rhythm. This important form of regulation is mediated by a resident Ca2+ sensor, calmodulin (CaM), which is comprised of two lobes that are each capable of responding to spatially distinct Ca2+ sources. Disruption of CaM-mediated CDI leads to severe forms of long-QT syndrome (LQTS) and life-threatening arrhythmias. Thus, a model capable of capturing the nuances of CaM-mediated CDI would facilitate increased understanding of cardiac (patho)physiology. However, one critical barrier to achieving a detailed kinetic model of CDI has been the lack of quantitative data characterizing CDI as a function of Ca2+. This data deficit stems from the experimental challenge of uncoupling the effect of channel gating on Ca2+ entry. To overcome this obstacle, we use photo-uncaging of Ca2+ to deliver a measurable Ca2+ input to CaM/LTCCs, while simultaneously recording CDI. Moreover, we use engineered CaMs with Ca2+ binding restricted to a single lobe, to isolate the kinetic response of each lobe. These high-resolution measurements enable us to build mathematical models for each lobe of CaM, which we use as building blocks for a full-scale bilobal model of CDI. Finally, we use this model to probe the pathogenesis of LQTS associated with mutations in CaM (calmodulinopathies). Each of these models accurately recapitulates the kinetics and steady-state properties of CDI in both physiological and pathological states, thus offering powerful new insights into the mechanistic alterations underlying cardiac arrhythmias.
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Affiliation(s)
- Worawan B Limpitikul
- Calcium Signals Laboratory, Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Joseph L Greenstein
- Institute for Computational Medicine, Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD
| | - David T Yue
- Calcium Signals Laboratory, Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Ivy E Dick
- Calcium Signals Laboratory, Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD .,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD
| | - Raimond L Winslow
- Institute for Computational Medicine, Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD
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38
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Affiliation(s)
- Donald M Bers
- From the Department of Pharmacology, University of California, Davis.
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39
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Jensen HH, Brohus M, Nyegaard M, Overgaard MT. Human Calmodulin Mutations. Front Mol Neurosci 2018; 11:396. [PMID: 30483049 PMCID: PMC6243062 DOI: 10.3389/fnmol.2018.00396] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 10/11/2018] [Indexed: 01/18/2023] Open
Abstract
Fluxes of calcium (Ca2+) across cell membranes enable fast cellular responses. Calmodulin (CaM) senses local changes in Ca2+ concentration and relays the information to numerous interaction partners. The critical role of accurate Ca2+ signaling on cellular function is underscored by the fact that there are three independent CaM genes (CALM1-3) in the human genome. All three genes are functional and encode the exact same CaM protein. Moreover, CaM has a completely conserved amino acid sequence across all vertebrates. Given this degree of conservation, it was long thought that mutations in CaM were incompatible with life. It was therefore a big surprise when the first CaM mutations in humans were identified six years ago. Today, more than a dozen human CaM missense mutations have been described, all found in patients with severe cardiac arrhythmias. Biochemical studies have demonstrated differential effects on Ca2+ binding affinities for these CaM variants. Moreover, CaM regulation of central cardiac ion channels is impaired, including the voltage-gated Ca2+ channel, CaV1.2, and the sarcoplasmic reticulum Ca2+ release channel, ryanodine receptor isoform 2, RyR2. Currently, no non-cardiac phenotypes have been described for CaM variant carriers. However, sequencing of large human cohorts reveals a cumulative frequency of additional rare CaM mutations that raise the possibility of CaM variants not exclusively causing severe cardiac arrhythmias. Here, we provide an overview of the identified CaM variants and their known consequences for target regulation and cardiac disease phenotype. We discuss experimental data, patient genotypes and phenotypes as well as which questions remain open to understand this complexity.
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Affiliation(s)
- Helene H Jensen
- Section for Biotechnology, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Malene Brohus
- Section for Biotechnology, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Mette Nyegaard
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Michael T Overgaard
- Section for Biotechnology, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
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40
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Giudicessi JR, Ackerman MJ. Calcium Revisited: New Insights Into the Molecular Basis of Long-QT Syndrome. Circ Arrhythm Electrophysiol 2018; 9:CIRCEP.116.002480. [PMID: 27390209 DOI: 10.1161/circep.116.002480] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/27/2016] [Indexed: 12/12/2022]
Affiliation(s)
- John R Giudicessi
- From the Internal Medicine Residency and Clinician-Investigator Programs, Department of Medicine (J.R.G.) and Departments of Cardiovascular Diseases, Pediatrics (Division of Pediatric Cardiology), and Molecular Pharmacology & Experimental Therapeutics (M.J.A.), Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | - Michael J Ackerman
- From the Internal Medicine Residency and Clinician-Investigator Programs, Department of Medicine (J.R.G.) and Departments of Cardiovascular Diseases, Pediatrics (Division of Pediatric Cardiology), and Molecular Pharmacology & Experimental Therapeutics (M.J.A.), Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN.
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Shaik NA, Awan ZA, Verma PK, Elango R, Banaganapalli B. Protein phenotype diagnosis of autosomal dominant calmodulin mutations causing irregular heart rhythms. J Cell Biochem 2018; 119:8233-8248. [PMID: 29932249 DOI: 10.1002/jcb.26834] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 03/09/2018] [Indexed: 12/21/2022]
Abstract
The life-threatening group of irregular cardiac rhythmic disorders also known as Cardiac Arrhythmias (CA) are caused by mutations in highly conserved Calmodulin (CALM/CaM) genes. Herein, we present a multidimensional approach to diagnose changes in phenotypic, stability, and Ca2+ ion binding properties of CA-causing mutations. Mutation pathogenicity was determined by diverse computational machine learning approaches. We further modeled the mutations in 3D protein structure and analyzed residue level phenotype plasticity. We have also examined the influence of torsion angles, number of H-bonds, and free energy dynamics on the stability, near-native simulation dynamic potential of residue fluctuations in protein structures, Ca2+ ion binding potentials, of CaM mutants. Our study recomends to use M-CAP method for measuring the pathogenicity of CA causing CaM variants. Interestingly, most CA-causing variants we analyzed, exists in either third (V/H-96, S/I-98, V-103) or fourth (G/V-130, V/E/H-132, H-134, P-136, G-141, and L-142) EF-hands located in carboxyl domains of the CaM molecule. We observed that the minor structural fluctuations caused by these variants are likely tolerable owing to the highly flexible nature of calmodulin's globular domains. However, our molecular docking results supports that these variants disturb the affinity of CaM toward Ca2+ ions and corroborate previous findings from functional studies. Taken together, these computational findings can explain the molecular reasons for subtle changes in structure, flexibility, and stability aspects of mutant CaM molecule. Our comprehensive molecular scanning approach demonstrates the utility of computational methods in quick preliminary screening of CA- CaM mutations before undertaking time consuming and complicated functional laboratory assays.
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Affiliation(s)
- Noor A Shaik
- Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.,Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders (PACER-HD), King Abdulaziz University, Jeddah, Saudi Arabia
| | - Zuhier A Awan
- Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Prashant K Verma
- Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ramu Elango
- Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.,Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders (PACER-HD), King Abdulaziz University, Jeddah, Saudi Arabia
| | - Babajan Banaganapalli
- Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.,Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders (PACER-HD), King Abdulaziz University, Jeddah, Saudi Arabia
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Limpitikul WB, Viswanathan MC, O'Rourke B, Yue DT, Cammarato A. Conservation of cardiac L-type Ca 2+ channels and their regulation in Drosophila: A novel genetically-pliable channelopathic model. J Mol Cell Cardiol 2018; 119:64-74. [PMID: 29684406 PMCID: PMC6154789 DOI: 10.1016/j.yjmcc.2018.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 04/08/2018] [Accepted: 04/11/2018] [Indexed: 01/28/2023]
Abstract
Dysregulation of L-type Ca2+ channels (LTCCs) underlies numerous cardiac pathologies. Understanding their modulation with high fidelity relies on investigating LTCCs in their native environment with intact interacting proteins. Such studies benefit from genetic manipulation of endogenous channels in cardiomyocytes, which often proves cumbersome in mammalian models. Drosophila melanogaster, however, offers a potentially efficient alternative as it possesses a relatively simple heart, is genetically pliable, and expresses well-conserved genes. Fluorescence in situ hybridization confirmed an abundance of Ca-α1D and Ca-α1T mRNA in fly myocardium, which encode subunits that specify hetero-oligomeric channels homologous to mammalian LTCCs and T-type Ca2+ channels, respectively. Cardiac-specific knockdown of Ca-α1D via interfering RNA abolished cardiac contraction, suggesting Ca-α1D (i.e. A1D) represents the primary functioning Ca2+ channel in Drosophila hearts. Moreover, we successfully isolated viable single cardiomyocytes and recorded Ca2+ currents via patch clamping, a feat never before accomplished with the fly model. The profile of Ca2+ currents recorded in individual cells when Ca2+ channels were hypomorphic, absent, or under selective LTCC blockage by nifedipine, additionally confirmed the predominance of A1D current across all activation voltages. T-type current, activated at more negative voltages, was also detected. Lastly, A1D channels displayed Ca2+-dependent inactivation, a critical negative feedback mechanism of LTCCs, and the current through them was augmented by forskolin, an activator of the protein kinase A pathway. In sum, the Drosophila heart possesses a conserved compendium of Ca2+ channels, suggesting that the fly may serve as a robust and effective platform for studying cardiac channelopathies.
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Affiliation(s)
- Worawan B Limpitikul
- Calcium Signals Laboratory, Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States
| | - Meera C Viswanathan
- Institute of CardioScience, Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States
| | - Brian O'Rourke
- Institute of CardioScience, Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States
| | - David T Yue
- Calcium Signals Laboratory, Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States
| | - Anthony Cammarato
- Institute of CardioScience, Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States; Department of Physiology, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, United States.
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43
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Gu M, Zhu Y, Yin X, Zhang DM. Small-conductance Ca 2+-activated K + channels: insights into their roles in cardiovascular disease. Exp Mol Med 2018; 50:1-7. [PMID: 29651007 PMCID: PMC5938042 DOI: 10.1038/s12276-018-0043-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 12/11/2017] [Accepted: 12/12/2017] [Indexed: 12/13/2022] Open
Abstract
Life-threatening malignant arrhythmias in pathophysiological conditions can increase the mortality and morbidity of patients with cardiovascular diseases. Cardiac electrical activity depends on the coordinated propagation of excitatory stimuli and the generation of action potentials in cardiomyocytes. Action potential formation results from the opening and closing of ion channels. Recent studies have indicated that small-conductance calcium-activated potassium (SK) channels play a critical role in cardiac repolarization in pathophysiological but not normal physiological conditions. The aim of this review is to describe the role of SK channels in healthy and diseased hearts, to suggest cardiovascular pathophysiologic targets for intervention, and to discuss studies of agents that target SK channels for the treatment of cardiovascular diseases.
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Affiliation(s)
- Mingxia Gu
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Jiangsu, 210006, Nanjing, China
- Department of Cardiology, Nanjing Central Hospital, Jiangsu, 210018, Nanjing, China
| | - Yanrong Zhu
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Jiangsu, 210006, Nanjing, China
| | - Xiaorong Yin
- Department of Cardiology, Nanjing Central Hospital, Jiangsu, 210018, Nanjing, China
| | - Dai-Min Zhang
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Jiangsu, 210006, Nanjing, China.
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Dainis AM, Ashley EA. Cardiovascular Precision Medicine in the Genomics Era. JACC Basic Transl Sci 2018; 3:313-326. [PMID: 30062216 PMCID: PMC6059349 DOI: 10.1016/j.jacbts.2018.01.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/31/2017] [Accepted: 01/02/2018] [Indexed: 12/20/2022]
Abstract
Precision medicine strives to delineate disease using multiple data sources-from genomics to digital health metrics-in order to be more precise and accurate in our diagnoses, definitions, and treatments of disease subtypes. By defining disease at a deeper level, we can treat patients based on an understanding of the molecular underpinnings of their presentations, rather than grouping patients into broad categories with one-size-fits-all treatments. In this review, the authors examine how precision medicine, specifically that surrounding genetic testing and genetic therapeutics, has begun to make strides in both common and rare cardiovascular diseases in the clinic and the laboratory, and how these advances are beginning to enable us to more effectively define risk, diagnose disease, and deliver therapeutics for each individual patient.
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Key Words
- CAD, coronary artery disease
- CF, cystic fibrosis
- CHD, coronary heart disease
- CML, chronic myelogenous leukemia
- CRS, conventional risk score
- CVD, cardiovascular disease
- CaM, calmodulin
- DCM, dilated cardiomyopathy
- DMD, Duchenne muscular dystrophy
- FH, familial hypercholesterolemia
- GRS, genomic risk score
- HCM, hypertrophic cardiomyopathy
- HDR, homology directed repair
- IVF, in vitro fertilization
- LDL-C, low-density lipoprotein cholesterol
- LQTS, long QT syndrome
- NGS, next-generation sequencing
- PGD, preimplantation genetic diagnosis
- SNP, single nucleotide polymorphism
- genome sequencing
- genomics
- iPSC, induced pluripotent stem cells
- precision medicine
- ssODN, single-stranded oligodeoxynucleotide
- targeted therapeutics
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Affiliation(s)
| | - Euan A. Ashley
- Department of Genetics, Stanford University, Stanford, California
- Department of Medicine, Stanford University, Stanford, California
- Stanford Center for Inherited Cardiovascular Disease, Stanford University, Stanford, California
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45
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Cao ZZ, Tian YJ, Hao J, Zhang PH, Liu ZP, Jiang WZ, Zeng ML, Zhang PP, Ma JH. Barbaloin inhibits ventricular arrhythmias in rabbits by modulating voltage-gated ion channels. Acta Pharmacol Sin 2018; 39:357-370. [PMID: 29072259 DOI: 10.1038/aps.2017.93] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/17/2017] [Indexed: 12/15/2022] Open
Abstract
Barbaloin (10-β-D-glucopyranosyl-1,8-dihydroxy-3-(hydroxymethyl)-9(10H)-anthracenone) is extracted from the aloe plant and has been reported to have anti-inflammatory, antitumor, antibacterial, and other biological activities. Here, we investigated the effects of barbaloin on cardiac electrophysiology, which has not been reported thus far. Cardiac action potentials (APs) and ionic currents were recorded in isolated rabbit ventricular myocytes using whole-cell patch-clamp technique. Additionally, the antiarrhythmic effect of barbaloin was examined in Langendorff-perfused rabbit hearts. In current-clamp recording, application of barbaloin (100 and 200 μmol/L) dose-dependently reduced the action potential duration (APD) and the maximum depolarization velocity (Vmax), and attenuated APD reverse-rate dependence (RRD) in ventricular myocytes. Furthermore, barbaloin (100 and 200 μmol/L) effectively eliminated ATX II-induced early afterdepolarizations (EADs) and Ca2+-induced delayed afterdepolarizations (DADs) in ventricular myocytes. In voltage-clamp recording, barbaloin (10-200 μmol/L) dose-dependently inhibited L-type calcium current (ICa.L) and peak sodium current (INa.P) with IC50 values of 137.06 and 559.80 μmol/L, respectively. Application of barbaloin (100, 200 μmol/L) decreased ATX II-enhanced late sodium current (INa.L) by 36.6%±3.3% and 71.8%±6.5%, respectively. However, barbaloin up to 800 μmol/L did not affect the inward rectifier potassium current (IK1) or the rapidly activated delayed rectifier potassium current (IKr) in ventricular myocytes. In Langendorff-perfused rabbit hearts, barbaloin (200 μmol/L) significantly inhibited aconitine-induced ventricular arrhythmias. These results demonstrate that barbaloin has potential as an antiarrhythmic drug.
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46
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Yamamoto Y, Makiyama T, Harita T, Sasaki K, Wuriyanghai Y, Hayano M, Nishiuchi S, Kohjitani H, Hirose S, Chen J, Yokoi F, Ishikawa T, Ohno S, Chonabayashi K, Motomura H, Yoshida Y, Horie M, Makita N, Kimura T. Allele-specific ablation rescues electrophysiological abnormalities in a human iPS cell model of long-QT syndrome with a CALM2 mutation. Hum Mol Genet 2017; 26:1670-1677. [PMID: 28335032 DOI: 10.1093/hmg/ddx073] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/22/2017] [Indexed: 12/14/2022] Open
Abstract
Calmodulin is a ubiquitous Ca2+ sensor molecule encoded by three distinct calmodulin genes, CALM1-3. Recently, mutations in CALM1-3 have been reported to be associated with severe early-onset long-QT syndrome (LQTS). However, the underlying mechanism through which heterozygous calmodulin mutations lead to severe LQTS remains unknown, particularly in human cardiomyocytes. We aimed to establish an LQTS disease model associated with a CALM2 mutation (LQT15) using human induced pluripotent stem cells (hiPSCs) and to assess mutant allele-specific ablation by genome editing for the treatment of LQT15. We generated LQT15-hiPSCs from a 12-year-old boy with LQTS carrying a CALM2-N98S mutation and differentiated these hiPSCs into cardiomyocytes (LQT15-hiPSC-CMs). Action potentials (APs) and L-type Ca2+ channel (LTCC) currents in hiPSC-CMs were analyzed by the patch-clamp technique and compared with those of healthy controls. Furthermore, we performed mutant allele-specific knockout using a CRISPR-Cas9 system and analyzed electrophysiological properties. Electrophysiological analyses revealed that LQT15-hiPSC-CMs exhibited significantly lower beating rates, prolonged AP durations, and impaired inactivation of LTCC currents compared with control cells, consistent with clinical phenotypes. Notably, ablation of the mutant allele rescued the electrophysiological abnormalities of LQT15-hiPSC-CMs, indicating that the mutant allele caused dominant-negative suppression of LTCC inactivation, resulting in prolonged AP duration. We successfully recapitulated the disease phenotypes of LQT15 and revealed that inactivation of LTCC currents was impaired in CALM2-N98S hiPSC model. Additionally, allele-specific ablation using the latest genome-editing technology provided important insights into a promising therapeutic approach for inherited cardiac diseases.
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Affiliation(s)
- Yuta Yamamoto
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
| | - Takeru Makiyama
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
| | - Takeshi Harita
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
| | - Kenichi Sasaki
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
| | - Yimin Wuriyanghai
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan.,Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Seta-Tsukinowa, Otsu 520-2192, Japan
| | - Mamoru Hayano
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
| | - Suguru Nishiuchi
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
| | - Hirohiko Kohjitani
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
| | - Sayako Hirose
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
| | - Jiarong Chen
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
| | - Fumika Yokoi
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
| | - Taisuke Ishikawa
- Department of Molecular Physiology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8523, Japan
| | - Seiko Ohno
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Seta-Tsukinowa, Otsu 520-2192, Japan
| | - Kazuhisa Chonabayashi
- Department of Life Science Frontiers, Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Hideki Motomura
- Department of Pediatrics, Nagasaki University Hospital, Nagasaki 852-8501, Japan
| | - Yoshinori Yoshida
- Department of Life Science Frontiers, Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Seta-Tsukinowa, Otsu 520-2192, Japan
| | - Naomasa Makita
- Department of Molecular Physiology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8523, Japan
| | - Takeshi Kimura
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
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47
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Rocchetti M, Sala L, Dreizehnter L, Crotti L, Sinnecker D, Mura M, Pane LS, Altomare C, Torre E, Mostacciuolo G, Severi S, Porta A, De Ferrari GM, George AL, Schwartz PJ, Gnecchi M, Moretti A, Zaza A. Elucidating arrhythmogenic mechanisms of long-QT syndrome CALM1-F142L mutation in patient-specific induced pluripotent stem cell-derived cardiomyocytes. Cardiovasc Res 2017; 113:531-541. [PMID: 28158429 DOI: 10.1093/cvr/cvx006] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 01/15/2017] [Indexed: 12/29/2022] Open
Abstract
Aims Calmodulin (CaM) is a small protein, encoded by three genes (CALM1-3), exerting multiple Ca2+-dependent modulatory roles. A mutation (F142L) affecting only one of the six CALM alleles is associated with long QT syndrome (LQTS) characterized by recurrent cardiac arrests. This phenotypic severity is unexpected from the predicted allelic balance. In this work, the effects of heterozygous CALM1-F142L have been investigated in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) obtained from a LQTS patient carrying the F142L mutation, i.e. in the context of native allelic ratio and potential gene modifiers. Methods and Results Skin fibroblasts of the mutation carrier and two unrelated healthy subjects (controls) were reprogrammed to hiPSC and differentiated into hiPSC-CMs. Scanty IK1 expression, an hiPSC-CMs feature potentially biasing repolarization, was corrected by addition of simulated IK1 (Dynamic-Clamp). Abnormalities in repolarization rate-dependency (in single cells and cell aggregates), membrane currents and intracellular Ca2+ dynamics were evaluated as putative arrhythmogenic factors. CALM1-F142L prolonged repolarization, altered its rate-dependency and its response to isoproterenol. This was associated with severe impairment of Ca2+-dependent inactivation (CDI) of ICaL, resulting in augmented inward current during the plateau phase. As a result, the repolarization of mutant cells failed to adapt to high pacing rates, a finding well reproduced by using a recent hiPSC-CM action potential model. The mutation failed to affect IKs and INaL and changed If only marginally. Intracellular Ca2+ dynamics and Ca2+ store stability were not significantly modified. Mutation-induced repolarization abnormalities were reversed by verapamil. Conclusion The main functional derangement in CALM1-F142L was prolonged repolarization with altered rate-dependency and sensitivity to β-adrenergic stimulation. Impaired CDI of ICaL underlined the electrical abnormality, which was sensitive to ICaL blockade. High mutation penetrance was confirmed in the presence of the native genotype, implying strong dominance of effects.
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Affiliation(s)
- Marcella Rocchetti
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Luca Sala
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy.,Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Lisa Dreizehnter
- I. Medical Department - Cardiology, Klinikum Rechts der Isar- Technische Universität München, Munich, Germany
| | - Lia Crotti
- Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy.,Department of Molecular Medicine - Unit of Cardiology, University of Pavia, Pavia, Italy
| | - Daniel Sinnecker
- I. Medical Department - Cardiology, Klinikum Rechts der Isar- Technische Universität München, Munich, Germany
| | - Manuela Mura
- Department of Molecular Medicine - Unit of Cardiology, University of Pavia, Pavia, Italy.,Department of Cardiothoracic and Vascular Sciences - Coronary Care Unit and Laboratory of Clinical and Experimental Cardiology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Luna Simona Pane
- I. Medical Department - Cardiology, Klinikum Rechts der Isar- Technische Universität München, Munich, Germany
| | - Claudia Altomare
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Eleonora Torre
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Gaspare Mostacciuolo
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Stefano Severi
- Biomedical Engineering Laboratory D.E.I, University of Bologna, Cesena, Italy
| | - Alberto Porta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.,Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
| | - Gaetano M De Ferrari
- Department of Molecular Medicine - Unit of Cardiology, University of Pavia, Pavia, Italy.,Department of Cardiothoracic and Vascular Sciences - Coronary Care Unit and Laboratory of Clinical and Experimental Cardiology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Alfred L George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Peter J Schwartz
- Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Massimiliano Gnecchi
- Department of Molecular Medicine - Unit of Cardiology, University of Pavia, Pavia, Italy.,Department of Cardiothoracic and Vascular Sciences - Coronary Care Unit and Laboratory of Clinical and Experimental Cardiology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.,Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Alessandra Moretti
- I. Medical Department - Cardiology, Klinikum Rechts der Isar- Technische Universität München, Munich, Germany.,DZHK (German Centre for Cardiovascular Research) - Partner Site Munich Heart Alliance, Munich, Germany
| | - Antonio Zaza
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
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48
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Zhao R, Xie P, Zhang K, Tang Z, Chen X, Zhu X, Fan Y, Yang X, Zhang X. Selective effect of hydroxyapatite nanoparticles on osteoporotic and healthy bone formation correlates with intracellular calcium homeostasis regulation. Acta Biomater 2017; 59:338-350. [PMID: 28698163 DOI: 10.1016/j.actbio.2017.07.009] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/20/2017] [Accepted: 07/05/2017] [Indexed: 01/21/2023]
Abstract
Adequate bone substitutes osseointegration has been difficult to achieve in osteoporosis. Hydroxyapatite of the osteoporotic bone, secreted by pathologic osteoblasts, had a smaller crystal size and lower crystallinity than that of the normal. To date, little is known regarding the interaction of synthetic hydroxyapatite nanoparticles (HANPs) with osteoblasts born in bone rarefaction. The present study investigated the biological effects of HANPs on osteoblastic cells derived from osteoporotic rat bone (OVX-OB), in comparison with the healthy ones (SHM-OB). A selective effect of different concentrations of HANPs on the two cell lines was observed that the osteoporotic osteoblasts had a higher tolerance. Reductions in cell proliferation, ALP activity, collagen secretion and osteoblastic gene expressions were found in the SHM-OB when administered with HANPs concentration higher than 25µg/ml. In contrast, those of the OVX-OB suffered no depression but benefited from 25 to 250µg/ml HANPs in a dose-dependent manner. We demonstrated that the different effects of HANPs on osteoblasts were associated with the intracellular calcium influx into the endoplasmic reticulum. The in vivo bone defect model further confirmed that, with a critical HANPs concentration administration, the osteoporotic rats had more and mechanically matured new bone formation than the non-treated ones, whilst the sham rats healed no better than the natural healing control. Collectively, the observed epigenetic regulation of osteoblastic cell function by HANPs has significant implication on defining design parameters for a potential therapeutic use of nanomaterials. STATEMENT OF SIGNIFICANCE In this study, we investigated the biological effects of hydroxyapatite nanoparticles (HANPs) on osteoporotic rat bone and the derived osteoblast. Our findings revealed a previously unrecognized phenomenon that the osteoporotic individuals could benefit from higher concentrations of HANPs, as compared with the healthy individuals. The in vivo bone defect model confirmed that, with a critical HANPs concentration administration, the osteoporotic rats had more mechanically matured new bone formation than the non-treated ones, whilst the sham rats healed no better than the natural healing control. The selective effect of HANPs might be associated with the intracellular calcium influx into the endoplasmic reticulum. Collectively, the observed epigenetic regulation by HANPs has significant implication on defining design parameters for a potential therapeutic use of nanomaterials in a pathological condition.
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Affiliation(s)
- Rui Zhao
- National Engineering Research Center for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China
| | - Pengfei Xie
- National Engineering Research Center for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China
| | - Kun Zhang
- National Engineering Research Center for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China
| | - Zhurong Tang
- National Engineering Research Center for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China
| | - Xuening Chen
- National Engineering Research Center for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China
| | - Xiangdong Zhu
- National Engineering Research Center for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China
| | - Yujiang Fan
- National Engineering Research Center for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China
| | - Xiao Yang
- National Engineering Research Center for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China.
| | - Xingdong Zhang
- National Engineering Research Center for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China.
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49
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Webster G, Schoppen ZJ, George AL. Treatment of calmodulinopathy with verapamil. BMJ Case Rep 2017; 2017:bcr-2017-220568. [PMID: 28784889 DOI: 10.1136/bcr-2017-220568] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Pathological variants in genes encoding calmodulin are associated with severe clinical presentations, including recurrent ventricular fibrillation and sudden death. Beta-receptor antagonists (beta-blockers) and sodium-channel antagonists have been reported as pharmacotherapies in these disorders; however, recent data have demonstrated the importance of derangements in calcium channel inactivation. We report a sustained attempt to use calcium-channel antagonists to treat calmodulinopathy and review the treatment strategies reported in the literature to date.
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Affiliation(s)
- Gregory Webster
- Division of Cardiology, Ann and Robert H Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - Zachary J Schoppen
- Division of Cardiology, Ann and Robert H Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - Alfred L George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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50
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Wei XH, Yu SD, Ren L, Huang SH, Yang QM, Wang P, Chu YP, Yang W, Ding YS, Huo Y, Wu L. Inhibition of late sodium current suppresses calcium-related ventricular arrhythmias by reducing the phosphorylation of CaMK-II and sodium channel expressions. Sci Rep 2017; 7:981. [PMID: 28428622 PMCID: PMC5430524 DOI: 10.1038/s41598-017-01056-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 03/20/2017] [Indexed: 12/19/2022] Open
Abstract
Cardiac arrhythmias associated with intracellular calcium inhomeostasis are refractory to antiarrhythmic therapy. We hypothesized that late sodium current (I Na) contributed to the calcium-related arrhythmias. Monophasic action potential duration at 90% completion of repolarization (MAPD90) was significantly increased and ventricular arrhythmias were observed in hearts with increased intracellular calcium concentration ([Ca2+]i) by using Bay K 8644, and the increase became greater in hearts treated with a combination of ATX-II and Bay K 8644 compared to Bay K 8644 alone. The prolongations caused by Bay K 8644 and frequent episodes of ventricular tachycardias, both in absence and presence of ATX-II, were significantly attenuated or abolished by late I Na inhibitors TTX and eleclazine. In rabbit ventricular myocytes, Bay K 8644 increased I CaL density, calcium transient and myocyte contraction. TTX and eleclazine decreased the amplitude of late I Na, the reverse use dependence of MAPD90 at slower heart rate, and attenuated the increase of intracellular calcium transient and myocyte contraction. TTX diminished the phosphorylation of CaMKII-δ and Nav 1.5 in hearts treated with Bay K 8644 and ATX-II. In conclusion, late I Na contributes to ventricular arrhythmias and its inhibition is plausible to treat arrhythmias in hearts with increased [Ca2+]i.
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Affiliation(s)
- Xiao-Hong Wei
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Shan-Dong Yu
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Lu Ren
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Si-Hui Huang
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Qiao-Mei Yang
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Ping Wang
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China
| | - Yan-Peng Chu
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Wei Yang
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Yan-Sheng Ding
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Yong Huo
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China. .,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China.
| | - Lin Wu
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China. .,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China.
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