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Burboa PC, Gaete PS, Shu P, Araujo PA, Beuve AV, Durán WN, Contreras JE, Lillo MA. Endothelial TRPV4/Cx43 Signaling Complex Regulates Vasomotor Tone in Resistance Arteries. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.25.604930. [PMID: 39091840 PMCID: PMC11291137 DOI: 10.1101/2024.07.25.604930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
S-nitrosylation of Cx43 gap junction channels critically regulates communication between smooth muscle cells and endothelial cells. This posttranslational modification also induces the opening of undocked Cx43 hemichannels. However, its specific impact on vasomotor regulation remains unclear. Considering the role of endothelial TRPV4 channel activation in promoting vasodilation through nitric oxide (NO) production, we investigated the direct modulation of endothelial Cx43 hemichannels by TRPV4 channel activation. Using the proximity ligation assay, we identify that Cx43 and TRPV4 are found in close proximity in the endothelium of resistance arteries. In primary endothelial cell cultures from resistance arteries (ECs), GSK-induced TRPV4 activation enhances eNOS activity, increases NO production, and opens Cx43 hemichannels via direct S-nitrosylation. Notably, the elevated intracellular Ca2+ levels caused by TRPV4 activation were reduced by blocking Cx43 hemichannels. In ex vivo mesenteric arteries, inhibiting Cx43 hemichannels reduced endothelial hyperpolarization without affecting NO production in ECs, underscoring a critical role of TRPV4/Cx43 signaling in endothelial electrical behavior. We perturbed the proximity of Cx43/TRPV4 by disrupting lipid rafts in ECs using β-cyclodextrin. Under these conditions, hemichannel activity, Ca2+ influx, and endothelial hyperpolarization were blunted upon GSK stimulation. Intravital microscopy of mesenteric arterioles in vivo further demonstrated that inhibiting Cx43 hemichannels activity, NO production and disrupting endothelial integrity reduce TRPV4-induced relaxation. These findings underscore a new pivotal role of Cx43 hemichannel associated with TRPV4 signaling pathway in modulating endothelial electrical behavior and vasomotor tone regulation.
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Affiliation(s)
- Pía C. Burboa
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ 07103, U.S.A
| | - Pablo S. Gaete
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA, U.S.A
| | - Ping Shu
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ 07103, U.S.A
| | - Priscila A. Araujo
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA, U.S.A
| | - Annie V. Beuve
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ 07103, U.S.A
| | - Walter N. Durán
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ 07103, U.S.A
| | - Jorge E. Contreras
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA, U.S.A
| | - Mauricio A. Lillo
- Department of Pharmacology, Physiology and Neuroscience, Rutgers-New Jersey Medical School, Newark, NJ 07103, U.S.A
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Zheng J, Dooge HC, Valdivia HH, Alvarado FJ. Ablation of three major phospho-sites in RyR2 preserves the global adrenergic response but creates an arrhythmogenic substrate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.08.602617. [PMID: 39026734 PMCID: PMC11257526 DOI: 10.1101/2024.07.08.602617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Background Ryanodine receptor 2 (RyR2) is one of the first substrates undergoing phosphorylation upon catecholaminergic stimulation. Yet, the role of RyR2 phosphorylation in the adrenergic response remains debated. To date, three residues in RyR2 are known to undergo phosphorylation upon adrenergic stimulation. We generated a model of RyR2 phospho-ablation of all three canonical phospho-sites (RyR2-S2031A/S2808A/S2814A, triple phospho-mutant, TPM) to elucidate the role of phosphorylation at these residues in the adrenergic response. Methods Cardiac structure and function, cellular Ca 2+ dynamics and electrophysiology, and RyR2 channel activity both under basal conditions and under isoproterenol (Iso) stimulation were systematically evaluated. We used echocardiography and electrocardiography in anesthetized mice, single-cell Ca 2+ imaging and whole-cell patch clamp in isolated adult cardiomyocytes, and biochemical assays. Results Iso stimulation produced normal chronotropic and inotropic responses in TPM mice as well as an increase in the global Ca 2+ transients in isolated cardiomyocytes. Functional studies revealed fewer Ca 2+ sparks in permeabilized TPM myocytes, and reduced RyR2-mediated Ca 2+ leak in intact myocytes under Iso stimulation, suggesting that the canonical sites may regulate RyR2-mediated Ca 2+ leak. TPM mice also displayed increased propensity for arrhythmia. TPM myocytes were prone to develop early afterdepolarizations (EADs), which were abolished by chelating intracellular Ca 2+ with EGTA, indicating that EADs require SR Ca 2+ release. EADs were also blocked by a low concentration of tetrodotoxin, further suggesting reactivation of the sodium current ( I Na ) as the underlying cause. Conclusion Phosphorylation of the three canonical residues on RyR2 may not be essential for the global adrenergic responses. However, these sites play a vital role in maintaining electrical stability during catecholamine stimulation by fine-tuning RyR2-mediated Ca 2+ leak. These findings underscore the importance of RyR2 phosphorylation and a finite diastolic Ca 2+ leak in maintaining electrical stability during catecholamine stimulation.
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3
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Vencato S, Romanato C, Rampazzo A, Calore M. Animal Models and Molecular Pathogenesis of Arrhythmogenic Cardiomyopathy Associated with Pathogenic Variants in Intercalated Disc Genes. Int J Mol Sci 2024; 25:6208. [PMID: 38892395 PMCID: PMC11172742 DOI: 10.3390/ijms25116208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 05/28/2024] [Accepted: 06/01/2024] [Indexed: 06/21/2024] Open
Abstract
Arrhythmogenic cardiomyopathy (ACM) is a rare genetic cardiac disease characterized by the progressive substitution of myocardium with fibro-fatty tissue. Clinically, ACM shows wide variability among patients; symptoms can include syncope and ventricular tachycardia but also sudden death, with the latter often being its sole manifestation. Approximately half of ACM patients have been found with variations in one or more genes encoding cardiac intercalated discs proteins; the most involved genes are plakophilin 2 (PKP2), desmoglein 2 (DSG2), and desmoplakin (DSP). Cardiac intercalated discs provide mechanical and electro-metabolic coupling among cardiomyocytes. Mechanical communication is guaranteed by the interaction of proteins of desmosomes and adheren junctions in the so-called area composita, whereas electro-metabolic coupling between adjacent cardiac cells depends on gap junctions. Although ACM has been first described almost thirty years ago, the pathogenic mechanism(s) leading to its development are still only partially known. Several studies with different animal models point to the involvement of the Wnt/β-catenin signaling in combination with the Hippo pathway. Here, we present an overview about the existing murine models of ACM harboring variants in intercalated disc components with a particular focus on the underlying pathogenic mechanisms. Prospectively, mechanistic insights into the disease pathogenesis will lead to the development of effective targeted therapies for ACM.
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Affiliation(s)
- Sara Vencato
- Department of Biology, University of Padova, Via U. Bassi 58/B, 35121 Padova, Italy; (S.V.); (C.R.); (A.R.)
| | - Chiara Romanato
- Department of Biology, University of Padova, Via U. Bassi 58/B, 35121 Padova, Italy; (S.V.); (C.R.); (A.R.)
| | - Alessandra Rampazzo
- Department of Biology, University of Padova, Via U. Bassi 58/B, 35121 Padova, Italy; (S.V.); (C.R.); (A.R.)
| | - Martina Calore
- Department of Biology, University of Padova, Via U. Bassi 58/B, 35121 Padova, Italy; (S.V.); (C.R.); (A.R.)
- Department of Molecular Genetics, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6211 LK Maastricht, The Netherlands
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4
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McNally EM. Timing and Implementation of Viral Gene Therapy for Cardiomyopathy. JACC. HEART FAILURE 2024; 12:771-775. [PMID: 38569827 DOI: 10.1016/j.jchf.2024.01.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 01/23/2024] [Indexed: 04/05/2024]
Affiliation(s)
- Elizabeth M McNally
- Center for Genetic Medicine, Bluhm Cardiovascular Institute, Northwestern University Feinberg School of Medicine, Chicago Illinois, USA.
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5
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Mesquita T, Lin YN, Chen S, Lee Y, Miguel-dos-Santos R, Atici AE, Fishbein MC, Rivas MN, Arditi M, Cingolani E. Inhibition of IL-1 Ameliorates Cardiac Dysfunction and Arrhythmias in a Murine Model of Kawasaki Disease. Arterioscler Thromb Vasc Biol 2024; 44:e117-e130. [PMID: 38385289 PMCID: PMC10978283 DOI: 10.1161/atvbaha.123.320382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/09/2024] [Indexed: 02/23/2024]
Abstract
BACKGROUND Kawasaki disease (KD) is an acute febrile illness and systemic vasculitis often associated with cardiac sequelae, including arrhythmias. Abundant evidence indicates a central role for IL (interleukin)-1 and TNFα (tumor necrosis factor-alpha) signaling in the formation of arterial lesions in KD. We aimed to investigate the mechanisms underlying the development of electrophysiological abnormalities in a murine model of KD vasculitis. METHODS Lactobacillus casei cell wall extract-induced KD vasculitis model was used to investigate the therapeutic efficacy of clinically relevant IL-1Ra (IL-1 receptor antagonist) and TNFα neutralization. Echocardiography, in vivo electrophysiology, whole-heart optical mapping, and imaging were performed. RESULTS KD vasculitis was associated with impaired ejection fraction, increased ventricular tachycardia, prolonged repolarization, and slowed conduction velocity. Since our transcriptomic analysis of human patients showed elevated levels of both IL-1β and TNFα, we asked whether either cytokine was linked to the development of myocardial dysfunction. Remarkably, only inhibition of IL-1 signaling by IL-1Ra but not TNFα neutralization was able to prevent changes in ejection fraction and arrhythmias, whereas both IL-1Ra and TNFα neutralization significantly improved vasculitis and heart vessel inflammation. The treatment of L casei cell wall extract-injected mice with IL-1Ra also restored conduction velocity and improved the organization of Cx43 (connexin 43) at the intercalated disk. In contrast, in mice with gain of function of the IL-1 signaling pathway, L casei cell wall extract induced spontaneous ventricular tachycardia and premature deaths. CONCLUSIONS Our results characterize the electrophysiological abnormalities associated with L casei cell wall extract-induced KD and show that IL-1Ra is more effective in preventing KD-induced myocardial dysfunction and arrhythmias than anti-TNFα therapy. These findings support the advancement of clinical trials using IL-1Ra in patients with KD.
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Affiliation(s)
- Thassio Mesquita
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Yen-Nien Lin
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Shuang Chen
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children’s at Cedars-Sinai Medical Center, Los Angeles, California, USA
- Infectious and Immunologic Diseases Research Center (IIDRC) and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Youngho Lee
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children’s at Cedars-Sinai Medical Center, Los Angeles, California, USA
- Infectious and Immunologic Diseases Research Center (IIDRC) and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | | | - Asli E. Atici
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children’s at Cedars-Sinai Medical Center, Los Angeles, California, USA
- Infectious and Immunologic Diseases Research Center (IIDRC) and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Michael C. Fishbein
- Department of Pathology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Magali Noval Rivas
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children’s at Cedars-Sinai Medical Center, Los Angeles, California, USA
- Infectious and Immunologic Diseases Research Center (IIDRC) and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Moshe Arditi
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children’s at Cedars-Sinai Medical Center, Los Angeles, California, USA
- Infectious and Immunologic Diseases Research Center (IIDRC) and Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Eugenio Cingolani
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
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Sommerfeld LC, Holmes AP, Yu TY, O'Shea C, Kavanagh DM, Pike JM, Wright T, Syeda F, Aljehani A, Kew T, Cardoso VR, Kabir SN, Hepburn C, Menon PR, Broadway-Stringer S, O'Reilly M, Witten A, Fortmueller L, Lutz S, Kulle A, Gkoutos GV, Pavlovic D, Arlt W, Lavery GG, Steeds R, Gehmlich K, Stoll M, Kirchhof P, Fabritz L. Reduced plakoglobin increases the risk of sodium current defects and atrial conduction abnormalities in response to androgenic anabolic steroid abuse. J Physiol 2024. [PMID: 38345865 DOI: 10.1113/jp284597] [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: 02/28/2023] [Accepted: 01/16/2024] [Indexed: 03/07/2024] Open
Abstract
Androgenic anabolic steroids (AAS) are commonly abused by young men. Male sex and increased AAS levels are associated with earlier and more severe manifestation of common cardiac conditions, such as atrial fibrillation, and rare ones, such as arrhythmogenic right ventricular cardiomyopathy (ARVC). Clinical observations suggest a potential atrial involvement in ARVC. Arrhythmogenic right ventricular cardiomyopathy is caused by desmosomal gene defects, including reduced plakoglobin expression. Here, we analysed clinical records from 146 ARVC patients to identify that ARVC is more common in males than females. Patients with ARVC also had an increased incidence of atrial arrhythmias and P wave changes. To study desmosomal vulnerability and the effects of AAS on the atria, young adult male mice, heterozygously deficient for plakoglobin (Plako+/- ), and wild type (WT) littermates were chronically exposed to 5α-dihydrotestosterone (DHT) or placebo. The DHT increased atrial expression of pro-hypertrophic, fibrotic and inflammatory transcripts. In mice with reduced plakoglobin, DHT exaggerated P wave abnormalities, atrial conduction slowing, sodium current depletion, action potential amplitude reduction and the fall in action potential depolarization rate. Super-resolution microscopy revealed a decrease in NaV 1.5 membrane clustering in Plako+/- atrial cardiomyocytes after DHT exposure. In summary, AAS combined with plakoglobin deficiency cause pathological atrial electrical remodelling in young male hearts. Male sex is likely to increase the risk of atrial arrhythmia, particularly in those with desmosomal gene variants. This risk is likely to be exaggerated further by AAS use. KEY POINTS: Androgenic male sex hormones, such as testosterone, might increase the risk of atrial fibrillation in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), which is often caused by desmosomal gene defects (e.g. reduced plakoglobin expression). In this study, we observed a significantly higher proportion of males who had ARVC compared with females, and atrial arrhythmias and P wave changes represented a common observation in advanced ARVC stages. In mice with reduced plakoglobin expression, chronic administration of 5α-dihydrotestosterone led to P wave abnormalities, atrial conduction slowing, sodium current depletion and a decrease in membrane-localized NaV 1.5 clusters. 5α-Dihydrotestosterone, therefore, represents a stimulus aggravating the pro-arrhythmic phenotype in carriers of desmosomal mutations and can affect atrial electrical function.
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Affiliation(s)
- Laura C Sommerfeld
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- University Center of Cardiovascular Science, University Heart and Vascular Center, UKE Hamburg, Hamburg, Germany
- German Center for Cardiovascular Research (DZHK), Standort Hamburg/Kiel/Lübeck, Germany
| | - Andrew P Holmes
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Ting Y Yu
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Research and Training Centre in Physical Sciences for Health, Birmingham, UK
| | - Christopher O'Shea
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Research and Training Centre in Physical Sciences for Health, Birmingham, UK
| | - Deirdre M Kavanagh
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Jeremy M Pike
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | - Thomas Wright
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Fahima Syeda
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Areej Aljehani
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Tania Kew
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Victor R Cardoso
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - S Nashitha Kabir
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Claire Hepburn
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Priyanka R Menon
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | | | - Molly O'Reilly
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Anika Witten
- Genetic Epidemiology, Institute for Human Genetics, University of Münster, Münster, Germany
- Core Facility Genomics of the Medical Faculty, University of Münster, Münster, Germany
| | - Lisa Fortmueller
- University Center of Cardiovascular Science, University Heart and Vascular Center, UKE Hamburg, Hamburg, Germany
- German Center for Cardiovascular Research (DZHK), Standort Hamburg/Kiel/Lübeck, Germany
- Genetic Epidemiology, Institute for Human Genetics, University of Münster, Münster, Germany
| | - Susanne Lutz
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen, Germany
| | - Alexandra Kulle
- Division of Paediatric Endocrinology and Diabetes, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Georgios V Gkoutos
- University Center of Cardiovascular Science, University Heart and Vascular Center, UKE Hamburg, Hamburg, Germany
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
- Institute of Translational Medicine, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- MRC Health Data Research UK (HDR), Midlands Site, UK
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Wiebke Arlt
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism (CEDAM), Birmingham Health Partners, Birmingham, UK
- Medical Research Council London Institute of Medical Sciences, London UK & Institute of Clinical Sciences, Faculty of Medicine, Imperial College, London, UK
| | - Gareth G Lavery
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism (CEDAM), Birmingham Health Partners, Birmingham, UK
| | - Richard Steeds
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Department of Cardiology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Katja Gehmlich
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Monika Stoll
- Genetic Epidemiology, Institute for Human Genetics, University of Münster, Münster, Germany
- Core Facility Genomics of the Medical Faculty, University of Münster, Münster, Germany
- Cardiovascular Research Institute Maastricht, Department of Biochemistry, Maastricht University, Maastricht, The Netherlands
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- German Center for Cardiovascular Research (DZHK), Standort Hamburg/Kiel/Lübeck, Germany
- Department of Cardiology, University Heart & Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- University Center of Cardiovascular Science, University Heart and Vascular Center, UKE Hamburg, Hamburg, Germany
- German Center for Cardiovascular Research (DZHK), Standort Hamburg/Kiel/Lübeck, Germany
- Department of Cardiology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- Department of Cardiology, University Heart & Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Jin Q, Lee KY, Selimi Z, Shimura D, Wang E, Zimmerman JF, Shaw RM, Kucera JP, Parker KK, Saffitz JE, Kleber AG. Determinants of electrical propagation and propagation block in Arrhythmogenic Cardiomyopathy. J Mol Cell Cardiol 2024; 186:71-80. [PMID: 37956903 PMCID: PMC10872523 DOI: 10.1016/j.yjmcc.2023.11.003] [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: 06/06/2023] [Revised: 10/27/2023] [Accepted: 11/06/2023] [Indexed: 11/21/2023]
Abstract
Gap junction and ion channel remodeling occur early in Arrhythmogenic Cardiomyopathy (ACM), but their pathogenic consequences have not been elucidated. Here, we identified the arrhythmogenic substrate, consisting of propagation slowing and conduction block, in ACM models expressing two different desmosomal gene variants. Neonatal rat ventricular myocytes were transduced to express variants in genes encoding desmosomal proteins plakoglobin or plakophilin-2. Studies were performed in engineered cells and anisotropic tissues to quantify changes in conduction velocity, formation of unidirectional propagation, cell-cell electrical coupling, and ion currents. Conduction velocity decreased by 71% and 63% in the two ACM models. SB216763, an inhibitor of glycogen synthase kinase-3 beta, restored conduction velocity to near normal levels. Compared to control, both ACM models showed greater propensity for unidirectional conduction block, which increased further at greater stimulation frequencies. Cell-cell electrical conductance measured in cell pairs was reduced by 86% and 87% in the two ACM models. Computer modeling showed close correspondence between simulated and experimentally determined changes in conduction velocity. The simulation identified that reduced cell-cell electrical coupling was the dominant factor leading to slow conduction, while the combination of reduced cell-cell electrical coupling, reduced sodium current and inward rectifier potassium current explained the development of unidirectional block. Expression of two different ACM variants markedly reduced cell-cell electrical coupling and conduction velocity, and greatly increased the likelihood of developing unidirectional block - both key features of arrhythmogenesis. This study provides the first quantitative analysis of cellular electrophysiological changes leading to the substrate of reentrant arrhythmias in early stage ACM.
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Affiliation(s)
- Qianru Jin
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - Keel Yong Lee
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - Zoja Selimi
- Department of Physiology, University of Bern, Bern, Switzerland
| | - Daisuke Shimura
- Nora Eccles Harrison Cardiovascular Research and Training Institute, Salt Lake City, UT, USA; Department of Surgery, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Ethan Wang
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - John F Zimmerman
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - Robin M Shaw
- Nora Eccles Harrison Cardiovascular Research and Training Institute, Salt Lake City, UT, USA
| | - Jan P Kucera
- Department of Physiology, University of Bern, Bern, Switzerland
| | - Kevin Kit Parker
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
| | - Jeffrey E Saffitz
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Andre G Kleber
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA; Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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8
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Stevens TL, Coles S, Sturm AC, Hoover CA, Borzok MA, Mohler PJ, El Refaey M. Molecular Pathways and Animal Models of Arrhythmias. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1441:1057-1090. [PMID: 38884769 DOI: 10.1007/978-3-031-44087-8_67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Arrhythmias account for over 300,000 annual deaths in the United States, and approximately half of all deaths are associated with heart disease. Mechanisms underlying arrhythmia risk are complex; however, work in humans and animal models over the past 25 years has identified a host of molecular pathways linked with both arrhythmia substrates and triggers. This chapter will focus on select arrhythmia pathways solved by linking human clinical and genetic data with animal models.
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Affiliation(s)
- Tyler L Stevens
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Sara Coles
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Amy C Sturm
- Genomic Medicine Institute, 23andMe, Sunnyvale, CA, USA
| | - Catherine A Hoover
- Department of Biochemistry, Chemistry, Engineering and Physics, Commonwealth University of Pennsylvania, Mansfield, PA, USA
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Maegen A Borzok
- Department of Biochemistry, Chemistry, Engineering and Physics, Commonwealth University of Pennsylvania, Mansfield, PA, USA
| | - Peter J Mohler
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Mona El Refaey
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
- Department of Surgery, Division of Cardiac Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
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9
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Atici AE, Crother TR, Noval Rivas M. Mitochondrial quality control in health and cardiovascular diseases. Front Cell Dev Biol 2023; 11:1290046. [PMID: 38020895 PMCID: PMC10657886 DOI: 10.3389/fcell.2023.1290046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Cardiovascular diseases (CVDs) are one of the primary causes of mortality worldwide. An optimal mitochondrial function is central to supplying tissues with high energy demand, such as the cardiovascular system. In addition to producing ATP as a power source, mitochondria are also heavily involved in adaptation to environmental stress and fine-tuning tissue functions. Mitochondrial quality control (MQC) through fission, fusion, mitophagy, and biogenesis ensures the clearance of dysfunctional mitochondria and preserves mitochondrial homeostasis in cardiovascular tissues. Furthermore, mitochondria generate reactive oxygen species (ROS), which trigger the production of pro-inflammatory cytokines and regulate cell survival. Mitochondrial dysfunction has been implicated in multiple CVDs, including ischemia-reperfusion (I/R), atherosclerosis, heart failure, cardiac hypertrophy, hypertension, diabetic and genetic cardiomyopathies, and Kawasaki Disease (KD). Thus, MQC is pivotal in promoting cardiovascular health. Here, we outline the mechanisms of MQC and discuss the current literature on mitochondrial adaptation in CVDs.
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Affiliation(s)
- Asli E. Atici
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children’s at Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Infectious and Immunologic Diseases Research Center (IIDRC), Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Timothy R. Crother
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children’s at Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Infectious and Immunologic Diseases Research Center (IIDRC), Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Magali Noval Rivas
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Guerin Children’s at Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Infectious and Immunologic Diseases Research Center (IIDRC), Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
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10
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Fan X, Yang G, Duru F, Grilli M, Akin I, Zhou X, Saguner AM, Ei-Battrawy I. Arrhythmogenic Cardiomyopathy: from Preclinical Models to Genotype-phenotype Correlation and Pathophysiology. Stem Cell Rev Rep 2023; 19:2683-2708. [PMID: 37731079 PMCID: PMC10661732 DOI: 10.1007/s12015-023-10615-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2023] [Indexed: 09/22/2023]
Abstract
Arrhythmogenic cardiomyopathy (ACM) is a hereditary myocardial disease characterized by the replacement of the ventricular myocardium with fibrous fatty deposits. ACM is usually inherited in an autosomal dominant pattern with variable penetrance and expressivity, which is mainly related to ventricular tachyarrhythmia and sudden cardiac death (SCD). Importantly, significant progress has been made in determining the genetic background of ACM due to the development of new techniques for genetic analysis. The exact molecular pathomechanism of ACM, however, is not completely clear and the genotype-phenotype correlations have not been fully elucidated, which are useful to predict the prognosis and treatment of ACM patients. Different gene-targeted and transgenic animal models, human-induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) models, and heterologous expression systems have been developed. Here, this review aims to summarize preclinical ACM models and platforms promoting our understanding of the pathogenesis of ACM and assess their value in elucidating the ACM genotype-phenotype relationship.
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Affiliation(s)
- Xuehui Fan
- Key Laboratory of Medical Electrophysiology, Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Collaborative Innovation Center for Prevention of Cardiovascular Diseases, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China
- Cardiology, Angiology, Haemostaseology, and Medical Intensive Care, Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
- European Center for AngioScience (ECAS), German Center for Cardiovascular Research (DZHK) Partner Site Heidelberg/ Mannheim, and Centre for Cardiovascular Acute Medicine Mannheim (ZKAM), Medical Centre Mannheim, Heidelberg University, Partner Site, Heidelberg-Mannheim, Germany
| | - Guoqiang Yang
- Cardiology, Angiology, Haemostaseology, and Medical Intensive Care, Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
- Department of Acupuncture and Rehabilitation, the Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China
- Research Unit of Molecular Imaging Probes, Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Firat Duru
- Department of Cardiology, University Heart Centre, University Hospital Zurich, Zurich, Switzerland
| | - Maurizio Grilli
- Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Ibrahim Akin
- Cardiology, Angiology, Haemostaseology, and Medical Intensive Care, Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
- European Center for AngioScience (ECAS), German Center for Cardiovascular Research (DZHK) Partner Site Heidelberg/ Mannheim, and Centre for Cardiovascular Acute Medicine Mannheim (ZKAM), Medical Centre Mannheim, Heidelberg University, Partner Site, Heidelberg-Mannheim, Germany
| | - Xiaobo Zhou
- Key Laboratory of Medical Electrophysiology, Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Collaborative Innovation Center for Prevention of Cardiovascular Diseases, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China.
- Cardiology, Angiology, Haemostaseology, and Medical Intensive Care, Medical Centre Mannheim, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany.
- European Center for AngioScience (ECAS), German Center for Cardiovascular Research (DZHK) Partner Site Heidelberg/ Mannheim, and Centre for Cardiovascular Acute Medicine Mannheim (ZKAM), Medical Centre Mannheim, Heidelberg University, Partner Site, Heidelberg-Mannheim, Germany.
- First Department of Medicine, University Medical Centre Mannheim, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
| | - Ardan Muammer Saguner
- Department of Cardiology, University Heart Centre, University Hospital Zurich, Zurich, Switzerland
| | - Ibrahim Ei-Battrawy
- European Center for AngioScience (ECAS), German Center for Cardiovascular Research (DZHK) Partner Site Heidelberg/ Mannheim, and Centre for Cardiovascular Acute Medicine Mannheim (ZKAM), Medical Centre Mannheim, Heidelberg University, Partner Site, Heidelberg-Mannheim, Germany.
- Department of Cardiology and Angiology, Ruhr University, Bochum, Germany; Institute of Physiology, Department of Cellular and Translational Physiology and Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr- University Bochum, Bochum, Germany.
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11
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Zhang Y, Zhang K, Prakosa A, James C, Zimmerman SL, Carrick R, Sung E, Gasperetti A, Tichnell C, Murray B, Calkins H, Trayanova NA. Predicting ventricular tachycardia circuits in patients with arrhythmogenic right ventricular cardiomyopathy using genotype-specific heart digital twins. eLife 2023; 12:RP88865. [PMID: 37851708 PMCID: PMC10584370 DOI: 10.7554/elife.88865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023] Open
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic cardiac disease that leads to ventricular tachycardia (VT), a life-threatening heart rhythm disorder. Treating ARVC remains challenging due to the complex underlying arrhythmogenic mechanisms, which involve structural and electrophysiological (EP) remodeling. Here, we developed a novel genotype-specific heart digital twin (Geno-DT) approach to investigate the role of pathophysiological remodeling in sustaining VT reentrant circuits and to predict the VT circuits in ARVC patients of different genotypes. This approach integrates the patient's disease-induced structural remodeling reconstructed from contrast-enhanced magnetic-resonance imaging and genotype-specific cellular EP properties. In our retrospective study of 16 ARVC patients with two genotypes: plakophilin-2 (PKP2, n = 8) and gene-elusive (GE, n = 8), we found that Geno-DT accurately and non-invasively predicted the VT circuit locations for both genotypes (with 100%, 94%, 96% sensitivity, specificity, and accuracy for GE patient group, and 86%, 90%, 89% sensitivity, specificity, and accuracy for PKP2 patient group), when compared to VT circuit locations identified during clinical EP studies. Moreover, our results revealed that the underlying VT mechanisms differ among ARVC genotypes. We determined that in GE patients, fibrotic remodeling is the primary contributor to VT circuits, while in PKP2 patients, slowed conduction velocity and altered restitution properties of cardiac tissue, in addition to the structural substrate, are directly responsible for the formation of VT circuits. Our novel Geno-DT approach has the potential to augment therapeutic precision in the clinical setting and lead to more personalized treatment strategies in ARVC.
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Affiliation(s)
- Yingnan Zhang
- Department of Biomedical Engineering, Johns Hopkins UniversityBaltimoreUnited States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins UniversityBaltimoreUnited States
| | - Kelly Zhang
- Department of Biomedical Engineering, Johns Hopkins UniversityBaltimoreUnited States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins UniversityBaltimoreUnited States
| | - Adityo Prakosa
- Department of Biomedical Engineering, Johns Hopkins UniversityBaltimoreUnited States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins UniversityBaltimoreUnited States
| | - Cynthia James
- Division of Cardiology, Department of Medicine, Johns Hopkins HospitalBaltimoreUnited States
| | | | - Richard Carrick
- Division of Cardiology, Department of Medicine, Johns Hopkins HospitalBaltimoreUnited States
| | - Eric Sung
- Department of Biomedical Engineering, Johns Hopkins UniversityBaltimoreUnited States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins UniversityBaltimoreUnited States
| | - Alessio Gasperetti
- Division of Cardiology, Department of Medicine, Johns Hopkins HospitalBaltimoreUnited States
| | - Crystal Tichnell
- Division of Cardiology, Department of Medicine, Johns Hopkins HospitalBaltimoreUnited States
| | - Brittney Murray
- Division of Cardiology, Department of Medicine, Johns Hopkins HospitalBaltimoreUnited States
| | - Hugh Calkins
- Division of Cardiology, Department of Medicine, Johns Hopkins HospitalBaltimoreUnited States
| | - Natalia A Trayanova
- Department of Biomedical Engineering, Johns Hopkins UniversityBaltimoreUnited States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins UniversityBaltimoreUnited States
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12
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Moccia F, Brunetti V, Soda T, Faris P, Scarpellino G, Berra-Romani R. Store-Operated Ca 2+ Entry as a Putative Target of Flecainide for the Treatment of Arrhythmogenic Cardiomyopathy. J Clin Med 2023; 12:5295. [PMID: 37629337 PMCID: PMC10455538 DOI: 10.3390/jcm12165295] [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: 06/23/2023] [Revised: 08/04/2023] [Accepted: 08/12/2023] [Indexed: 08/27/2023] Open
Abstract
Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder that may lead patients to sudden cell death through the occurrence of ventricular arrhythmias. ACM is characterised by the progressive substitution of cardiomyocytes with fibrofatty scar tissue that predisposes the heart to life-threatening arrhythmic events. Cardiac mesenchymal stromal cells (C-MSCs) contribute to the ACM by differentiating into fibroblasts and adipocytes, thereby supporting aberrant remodelling of the cardiac structure. Flecainide is an Ic antiarrhythmic drug that can be administered in combination with β-adrenergic blockers to treat ACM due to its ability to target both Nav1.5 and type 2 ryanodine receptors (RyR2). However, a recent study showed that flecainide may also prevent fibro-adipogenic differentiation by inhibiting store-operated Ca2+ entry (SOCE) and thereby suppressing spontaneous Ca2+ oscillations in C-MSCs isolated from human ACM patients (ACM C-hMSCs). Herein, we briefly survey ACM pathogenesis and therapies and then recapitulate the main molecular mechanisms targeted by flecainide to mitigate arrhythmic events, including Nav1.5 and RyR2. Subsequently, we describe the role of spontaneous Ca2+ oscillations in determining MSC fate. Next, we discuss recent work showing that spontaneous Ca2+ oscillations in ACM C-hMSCs are accelerated to stimulate their fibro-adipogenic differentiation. Finally, we describe the evidence that flecainide suppresses spontaneous Ca2+ oscillations and fibro-adipogenic differentiation in ACM C-hMSCs by inhibiting constitutive SOCE.
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Affiliation(s)
- Francesco Moccia
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.B.); (G.S.)
| | - Valentina Brunetti
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.B.); (G.S.)
| | - Teresa Soda
- Department of Health Sciences, University of Magna Graecia, 88100 Catanzaro, Italy;
| | - Pawan Faris
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
| | - Giorgia Scarpellino
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.B.); (G.S.)
| | - Roberto Berra-Romani
- Department of Biomedicine, School of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico;
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13
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Vielmuth F, Radeva MY, Yeruva S, Sigmund AM, Waschke J. cAMP: A master regulator of cadherin-mediated binding in endothelium, epithelium and myocardium. Acta Physiol (Oxf) 2023; 238:e14006. [PMID: 37243909 DOI: 10.1111/apha.14006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/05/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Regulation of cadherin-mediated cell adhesion is crucial not only for maintaining tissue integrity and barrier function in the endothelium and epithelium but also for electromechanical coupling within the myocardium. Therefore, loss of cadherin-mediated adhesion causes various disorders, including vascular inflammation and desmosome-related diseases such as the autoimmune blistering skin dermatosis pemphigus and arrhythmogenic cardiomyopathy. Mechanisms regulating cadherin-mediated binding contribute to the pathogenesis of diseases and may also be used as therapeutic targets. Over the last 30 years, cyclic adenosine 3',5'-monophosphate (cAMP) has emerged as one of the master regulators of cell adhesion in endothelium and, more recently, also in epithelial cells as well as in cardiomyocytes. A broad spectrum of experimental models from vascular physiology and cell biology applied by different generations of researchers provided evidence that not only cadherins of endothelial adherens junctions (AJ) but also desmosomal contacts in keratinocytes and the cardiomyocyte intercalated discs are central targets in this scenario. The molecular mechanisms involve protein kinase A- and exchange protein directly activated by cAMP-mediated regulation of Rho family GTPases and S665 phosphorylation of the AJ and desmosome adaptor protein plakoglobin. In line with this, phosphodiesterase 4 inhibitors such as apremilast have been proposed as a therapeutic strategy to stabilize cadherin-mediated adhesion in pemphigus and may also be effective to treat other disorders where cadherin-mediated binding is compromised.
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Affiliation(s)
- Franziska Vielmuth
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Mariya Y Radeva
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Sunil Yeruva
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Anna M Sigmund
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Jens Waschke
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, Munich, Germany
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14
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Zhang Y, Zhang K, Prakosa A, James C, Zimmerman SL, Carrick R, Sung E, Gasperetti A, Tichnell C, Murray B, Calkins H, Trayanova N. Predicting Ventricular Tachycardia Circuits in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy using Genotype-specific Heart Digital Twins. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.05.31.23290587. [PMID: 37398074 PMCID: PMC10312861 DOI: 10.1101/2023.05.31.23290587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic cardiac disease that leads to ventricular tachycardia (VT), a life-threatening heart rhythm disorder. Treating ARVC remains challenging due to the complex underlying arrhythmogenic mechanisms, which involve structural and electrophysiological (EP) remodeling. Here, we developed a novel genotype-specific heart digital twin (Geno-DT) approach to investigate the role of pathophysiological remodeling in sustaining VT reentrant circuits and to predict the VT circuits in ARVC patients of different genotypes. This approach integrates the patient's disease-induced structural remodeling reconstructed from contrast-enhanced magnetic-resonance imaging and genotype-specific cellular EP properties. In our retrospective study of 16 ARVC patients with two genotypes: plakophilin-2 (PKP2, n = 8) and gene-elusive (GE, n = 8), we found that Geno-DT accurately and non-invasively predicted the VT circuit locations for both genotypes (with 100%, 94%, 96% sensitivity, specificity, and accuracy for GE patient group, and 86%, 90%, 89% sensitivity, specificity, and accuracy for PKP2 patient group), when compared to VT circuit locations identified during clinical EP studies. Moreover, our results revealed that the underlying VT mechanisms differ among ARVC genotypes. We determined that in GE patients, fibrotic remodeling is the primary contributor to VT circuits, while in PKP2 patients, slowed conduction velocity and altered restitution properties of cardiac tissue, in addition to the structural substrate, are directly responsible for the formation of VT circuits. Our novel Geno-DT approach has the potential to augment therapeutic precision in the clinical setting and lead to more personalized treatment strategies in ARVC.
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Affiliation(s)
- Yingnan Zhang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, USA
| | - Kelly Zhang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, USA
| | - Adityo Prakosa
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, USA
| | - Cynthia James
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Stefan L Zimmerman
- Department of Radiology and Radiological Science, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Richard Carrick
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Eric Sung
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, USA
| | - Alessio Gasperetti
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Crystal Tichnell
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Brittney Murray
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Hugh Calkins
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Natalia Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, USA
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15
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Lillo MA, Muñoz M, Rhana P, Gaul-Muller K, Quan J, Shirokova N, Xie LH, Santana LF, Fraidenraich D, Contreras JE. Remodeled connexin 43 hemichannels alter cardiac excitability and promote arrhythmias. J Gen Physiol 2023; 155:e202213150. [PMID: 37191672 PMCID: PMC10192603 DOI: 10.1085/jgp.202213150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 01/25/2023] [Accepted: 04/24/2023] [Indexed: 05/17/2023] Open
Abstract
Connexin-43 (Cx43) is the most abundant protein forming gap junction channels (GJCs) in cardiac ventricles. In multiple cardiac pathologies, including hypertrophy and heart failure, Cx43 is found remodeled at the lateral side of the intercalated discs of ventricular cardiomyocytes. Remodeling of Cx43 has been long linked to spontaneous ventricular arrhythmia, yet the mechanisms by which arrhythmias develop are still debated. Using a model of dystrophic cardiomyopathy, we previously showed that remodeled Cx43 function as aberrant hemichannels (non-forming GJCs) that alter cardiomyocyte excitability and, consequently, promote arrhythmias. Here, we aim to evaluate if opening of remodeled Cx43 can serve as a general mechanism to alter cardiac excitability independent of cellular dysfunction associated with a particular cardiomyopathy. To address this issue, we used a genetically modified Cx43 knock-in mouse (S3A) that promotes cardiac remodeling of Cx43 protein without apparent cardiac dysfunction. Importantly, when S3A mice were subjected to cardiac stress using the β-adrenergic agonist isoproterenol (Iso), they displayed acute and severe arrhythmias, which were not observed in WT mice. Pretreatment of S3A mice with the Cx43 hemichannel blocker, Gap19, prevented Iso-induced abnormal electrocardiographic behavior. At the cellular level, when compared with WT, Iso-treated S3A cardiomyocytes showed increased membrane permeability, greater plasma membrane depolarization, and Ca2+ overload, which likely caused prolonged action potentials, delayed after depolarizations, and triggered activity. All these cellular dysfunctions were also prevented by Cx43 hemichannel blockers. Our results support the notion that opening of remodeled Cx43 hemichannels, regardless of the type of cardiomyopathy, is sufficient to mediate cardiac-stress-induced arrhythmogenicity.
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Affiliation(s)
- Mauricio A. Lillo
- Department of Pharmacology, Physiology and Neuroscience, Rutgers University, New Jersey Medical School, Newark, NJ, USA
| | - Manuel Muñoz
- Department of Physiology and Membrane Biology, University of California, Davis. Davis, CA, USA
| | - Paula Rhana
- Department of Physiology and Membrane Biology, University of California, Davis. Davis, CA, USA
| | - Kelli Gaul-Muller
- Department of Pharmacology, Physiology and Neuroscience, Rutgers University, New Jersey Medical School, Newark, NJ, USA
| | - Jonathan Quan
- Department of Physiology and Membrane Biology, University of California, Davis. Davis, CA, USA
| | - Natalia Shirokova
- Department of Pharmacology, Physiology and Neuroscience, Rutgers University, New Jersey Medical School, Newark, NJ, USA
| | - Lai-Hua Xie
- Department of Cell Biology and Molecular Medicine, Rutgers University, New Jersey Medical School, Newark, NJ, USA
| | - Luis Fernando Santana
- Department of Physiology and Membrane Biology, University of California, Davis. Davis, CA, USA
| | - Diego Fraidenraich
- Department of Cell Biology and Molecular Medicine, Rutgers University, New Jersey Medical School, Newark, NJ, USA
| | - Jorge E. Contreras
- Department of Pharmacology, Physiology and Neuroscience, Rutgers University, New Jersey Medical School, Newark, NJ, USA
- Department of Physiology and Membrane Biology, University of California, Davis. Davis, CA, USA
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16
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Nielsen MS, van Opbergen CJM, van Veen TAB, Delmar M. The intercalated disc: a unique organelle for electromechanical synchrony in cardiomyocytes. Physiol Rev 2023; 103:2271-2319. [PMID: 36731030 PMCID: PMC10191137 DOI: 10.1152/physrev.00021.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
The intercalated disc (ID) is a highly specialized structure that connects cardiomyocytes via mechanical and electrical junctions. Although described in some detail by light microscopy in the 19th century, it was in 1966 that electron microscopy images showed that the ID represented apposing cell borders and provided detailed insight into the complex ID nanostructure. Since then, much has been learned about the ID and its molecular composition, and it has become evident that a large number of proteins, not all of them involved in direct cell-to-cell coupling via mechanical or gap junctions, reside at the ID. Furthermore, an increasing number of functional interactions between ID components are emerging, leading to the concept that the ID is not the sum of isolated molecular silos but an interacting molecular complex, an "organelle" where components work in concert to bring about electrical and mechanical synchrony. The aim of the present review is to give a short historical account of the ID's discovery and an updated overview of its composition and organization, followed by a discussion of the physiological implications of the ID architecture and the local intermolecular interactions. The latter will focus on both the importance of normal conduction of cardiac action potentials as well as the impact on the pathophysiology of arrhythmias.
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Affiliation(s)
- Morten S Nielsen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chantal J M van Opbergen
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
| | - Toon A B van Veen
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mario Delmar
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
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17
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Miles C, Boukens BJ, Scrocco C, Wilde AA, Nademanee K, Haissaguerre M, Coronel R, Behr ER. Subepicardial Cardiomyopathy: A Disease Underlying J-Wave Syndromes and Idiopathic Ventricular Fibrillation. Circulation 2023; 147:1622-1633. [PMID: 37216437 PMCID: PMC11073566 DOI: 10.1161/circulationaha.122.061924] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 03/27/2023] [Indexed: 05/24/2023]
Abstract
Brugada syndrome (BrS), early repolarization syndrome (ERS), and idiopathic ventricular fibrillation (iVF) have long been considered primary electrical disorders associated with malignant ventricular arrhythmia and sudden cardiac death. However, recent studies have revealed the presence of subtle microstructural abnormalities of the extracellular matrix in some cases of BrS, ERS, and iVF, particularly within right ventricular subepicardial myocardium. Substrate-based ablation within this region has been shown to ameliorate the electrocardiographic phenotype and to reduce arrhythmia frequency in BrS. Patients with ERS and iVF may also exhibit low-voltage and fractionated electrograms in the ventricular subepicardial myocardium, which can be treated with ablation. A significant proportion of patients with BrS and ERS, as well as some iVF survivors, harbor pathogenic variants in the voltage-gated sodium channel gene, SCN5A, but the majority of genetic susceptibility of these disorders is likely to be polygenic. Here, we postulate that BrS, ERS, and iVF may form part of a spectrum of subtle subepicardial cardiomyopathy. We propose that impaired sodium current, along with genetic and environmental susceptibility, precipitates a reduction in epicardial conduction reserve, facilitating current-to-load mismatch at sites of structural discontinuity, giving rise to electrocardiographic changes and the arrhythmogenic substrate.
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Affiliation(s)
- Chris Miles
- Cardiovascular Clinical Academic Group, St. George’s University Hospitals’ NHS Foundation Trust and Molecular and Clinical Sciences Institute, St. George’s, University of London, UK (C.M., C.S., E.R.B.)
| | - Bastiaan J. Boukens
- Department of Medical Biology, University of Amsterdam, the Netherlands (B.J.B.)
- University of Maastricht, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, the Netherlands (B.J.B.)
| | - Chiara Scrocco
- Cardiovascular Clinical Academic Group, St. George’s University Hospitals’ NHS Foundation Trust and Molecular and Clinical Sciences Institute, St. George’s, University of London, UK (C.M., C.S., E.R.B.)
| | - Arthur A.M. Wilde
- Amsterdam UMC, University of Amsterdam, Department of Cardiology, the Netherlands (A.A.M.W.)
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, the Netherlands (A.A.M.W.)
- European Reference Network for rare, low-prevalence, and complex diseases of the heart: ERN GUARD-Heart (A.A.M.W., M.H.)
| | - Koonlawee Nademanee
- Center of Excellence in Arrhythmia Research Chulalongkorn University, Department of Medicine, Chulalongkorn University, Thailand (K.N.)
- Pacific Rim Electrophysiology Research Institute, Bumrungrad Hospital, Bangkok, Thailand (K.N.)
| | - Michel Haissaguerre
- European Reference Network for rare, low-prevalence, and complex diseases of the heart: ERN GUARD-Heart (A.A.M.W., M.H.)
- Institut Hospitalo-Universitaire Liryc, Electrophysiology and Heart Modeling Institute, Pessac, France (M.H.)
- Department of Electrophysiology and Cardiac Stimulation, Centre Hospitalier Universitaire de Bordeaux, France (M.H.)
| | - Ruben Coronel
- Department of Experimental Cardiology, Amsterdam University Medical Centers, Cardiovascular Science, the Netherlands (R.C.)
| | - Elijah R. Behr
- Cardiovascular Clinical Academic Group, St. George’s University Hospitals’ NHS Foundation Trust and Molecular and Clinical Sciences Institute, St. George’s, University of London, UK (C.M., C.S., E.R.B.)
- Mayo Clinic Healthcare, London, UK (E.R.B.)
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18
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Liang FX, Sall J, Petzold C, van Opbergen CJM, Liang X, Delmar M. Nanogold based protein localization enables subcellular visualization of cell junction protein by SBF-SEM. Methods Cell Biol 2023; 177:55-81. [PMID: 37451776 PMCID: PMC10612668 DOI: 10.1016/bs.mcb.2022.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Recent advances in volume electron microscopy (vEM) allow unprecedented visualization of the electron-dense structures of cells, tissues and model organisms at nanometric resolution in three dimensions (3D). Light-based microscopy has been widely used for specific localization of proteins; however, it is restricted by the diffraction limit of light, and lacks the ability to identify underlying structures. Here, we describe a protocol for ultrastructural detection, in three dimensions, of a protein (Connexin 43) expressed in the intercalated disc region of adult murine heart. Our protocol does not rest on the expression of genetically encoded proteins and it overcomes hurdles related to pre-embedding and immunolabeling, such as the penetration of the label and the preservation of the tissue. The pre-embedding volumetric immuno-electron microscopy (pre-embedding vIEM) protocol presented here combines several practical strategies to balance sample fixation with antigen and ultrastructural preservation, and penetration of labeling with blocking of non-specific antigen binding sites. The small 1.4 nm gold along with surrounded silver used as a detection marker buried in the sample also serves as a functional conductive resin that significantly reduces the charging of samples. Our protocol also presents strategies for facilitating the successful cutting of the samples during serial block-face scanning electron microscopy (SBF-SEM) imaging. Our results suggest that the small gold-based pre-embedding vIEM is an ideal labeling method for molecular localization throughout the depth of the sample at subcellular compartments and membrane microdomains.
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Affiliation(s)
- Feng-Xia Liang
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, United States; Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, United States.
| | - Joseph Sall
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, United States
| | - Chris Petzold
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, United States
| | - Chantal J M van Opbergen
- Leon H Charney Division of Cardiology, Department of Medicine, New York University Grossman School of Medicine, New York, NY, United States
| | - Xiangxi Liang
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, United States
| | - Mario Delmar
- Leon H Charney Division of Cardiology, Department of Medicine, New York University Grossman School of Medicine, New York, NY, United States
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19
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Mitochondrial connexin43 and mitochondrial K ATP channels modulate triggered arrhythmias in mouse ventricular muscle. Pflugers Arch 2023; 475:477-488. [PMID: 36707457 DOI: 10.1007/s00424-023-02789-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/21/2022] [Accepted: 01/18/2023] [Indexed: 01/29/2023]
Abstract
Connexin43 (Cx43) exits as hemichannels in the inner mitochondrial membrane. We examined how mitochondrial Cx43 and mitochondrial KATP channels affect the occurrence of triggered arrhythmias. To generate cardiac-specific Cx43-deficient (cCx43-/-) mice, Cx43flox/flox mice were crossed with α-MHC (Myh6)-cre+/- mice. The resulting offspring, Cx43flox/flox/Myh6-cre+/- mice (cCx43-/- mice) and their littermates (cCx43+/+ mice), were used. Trabeculae were dissected from the right ventricles of mouse hearts. Cardiomyocytes were enzymatically isolated from the ventricles of mouse hearts. Force was measured with a strain gauge in trabeculae (22°C). To assess arrhythmia susceptibility, the minimal extracellular Ca2+ concentration ([Ca2+]o,min), at which arrhythmias were induced by electrical stimulation, was determined in trabeculae. ROS production was estimated with 2',7'-dichlorofluorescein (DCF), mitochondrial membrane potential with tetramethylrhodamine methyl ester (TMRM), and Ca2+ spark frequency with fluo-4 and confocal microscopy in cardiomyocytes. ROS production within the mitochondria was estimated with MitoSoxRed and mitochondrial Ca2+ with rhod-2 in trabeculae. Diazoxide was used to activate mitochondrial KATP. Most of cCx43-/- mice died suddenly within 8 weeks. Cx43 was present in the inner mitochondrial membrane in cCx43+/+ mice but not in cCx43-/- mice. In cCx43-/- mice, the [Ca2+]o,min was lower, and Ca2+ spark frequency, the slope of DCF fluorescence intensity, MitoSoxRed fluorescence, and rhod-2 fluorescence were higher. TMRM fluorescence was more decreased in cCx43-/- mice. Most of these changes were suppressed by diazoxide. In addition, in cCx43-/- mice, antioxidant peptide SS-31 and N-acetyl-L-cysteine increased the [Ca2+]o,min. These results suggest that Cx43 deficiency activates Ca2+ leak from the SR, probably due to depolarization of mitochondrial membrane potential, an increase in mitochondrial Ca2+, and an increase in ROS production, thereby causing triggered arrhythmias, and that Cx43 hemichannel deficiency may be compensated by activation of mitochondrial KATP channels in mouse hearts.
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20
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Tsui H, van Kampen SJ, Han SJ, Meraviglia V, van Ham WB, Casini S, van der Kraak P, Vink A, Yin X, Mayr M, Bossu A, Marchal GA, Monshouwer-Kloots J, Eding J, Versteeg D, de Ruiter H, Bezstarosti K, Groeneweg J, Klaasen SJ, van Laake LW, Demmers JAA, Kops GJPL, Mummery CL, van Veen TAB, Remme CA, Bellin M, van Rooij E. Desmosomal protein degradation as an underlying cause of arrhythmogenic cardiomyopathy. Sci Transl Med 2023; 15:eadd4248. [PMID: 36947592 DOI: 10.1126/scitranslmed.add4248] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 03/01/2023] [Indexed: 03/24/2023]
Abstract
Arrhythmogenic cardiomyopathy (ACM) is an inherited progressive cardiac disease. Many patients with ACM harbor mutations in desmosomal genes, predominantly in plakophilin-2 (PKP2). Although the genetic basis of ACM is well characterized, the underlying disease-driving mechanisms remain unresolved. Explanted hearts from patients with ACM had less PKP2 compared with healthy hearts, which correlated with reduced expression of desmosomal and adherens junction (AJ) proteins. These proteins were also disorganized in areas of fibrotic remodeling. In vitro data from human-induced pluripotent stem cell-derived cardiomyocytes and microtissues carrying the heterozygous PKP2 c.2013delC pathogenic mutation also displayed impaired contractility. Knockin mice carrying the equivalent heterozygous Pkp2 c.1755delA mutation recapitulated changes in desmosomal and AJ proteins and displayed cardiac dysfunction and fibrosis with age. Global proteomics analysis of 4-month-old heterozygous Pkp2 c.1755delA hearts indicated involvement of the ubiquitin-proteasome system (UPS) in ACM pathogenesis. Inhibition of the UPS in mutant mice increased area composita proteins and improved calcium dynamics in isolated cardiomyocytes. Additional proteomics analyses identified lysine ubiquitination sites on the desmosomal proteins, which were more ubiquitinated in mutant mice. In summary, we show that a plakophilin-2 mutation can lead to decreased desmosomal and AJ protein expression through a UPS-dependent mechanism, which preceded cardiac remodeling. These findings suggest that targeting protein degradation and improving desmosomal protein stability may be a potential therapeutic strategy for the treatment of ACM.
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Affiliation(s)
- Hoyee Tsui
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584 CT, Netherlands
| | - Sebastiaan Johannes van Kampen
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584 CT, Netherlands
| | - Su Ji Han
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584 CT, Netherlands
| | - Viviana Meraviglia
- Department of Anatomy and Embryology, University Medical Center, Leiden, 2333 ZA, Netherlands
| | - Willem B van Ham
- Department of Medical Physiology, University Medical Center Utrecht, 3584 CM, Netherlands
| | - Simona Casini
- Department of Clinical and Experimental Cardiology, University Medical Center Amsterdam, 1105 AZ, Netherlands
| | - Petra van der Kraak
- Department of Pathology, University Medical Center Utrecht, 3584 CX, Netherlands
| | - Aryan Vink
- Department of Pathology, University Medical Center Utrecht, 3584 CX, Netherlands
| | - Xiaoke Yin
- James Black Centre, King's College, University of London, WC2R 2LS London, UK
| | - Manuel Mayr
- James Black Centre, King's College, University of London, WC2R 2LS London, UK
| | - Alexandre Bossu
- Department of Medical Physiology, University Medical Center Utrecht, 3584 CM, Netherlands
| | - Gerard A Marchal
- Department of Clinical and Experimental Cardiology, University Medical Center Amsterdam, 1105 AZ, Netherlands
| | - Jantine Monshouwer-Kloots
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584 CT, Netherlands
| | - Joep Eding
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584 CT, Netherlands
| | - Danielle Versteeg
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584 CT, Netherlands
| | - Hesther de Ruiter
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584 CT, Netherlands
| | - Karel Bezstarosti
- Proteomics Center, Erasmus Medical Center Rotterdam, 3015 CN, Netherlands
| | - Judith Groeneweg
- Department of Cardiology, University Medical Center Utrecht, 3584 CX, Netherlands
| | - Sjoerd J Klaasen
- Oncode Institute, Hubrecht Institute, Royal Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584 CT, Netherlands
| | - Linda W van Laake
- Department of Cardiology, University Medical Center Utrecht, 3584 CX, Netherlands
| | - Jeroen A A Demmers
- Proteomics Center, Erasmus Medical Center Rotterdam, 3015 CN, Netherlands
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute, Royal Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584 CT, Netherlands
| | - Christine L Mummery
- Department of Anatomy and Embryology, University Medical Center, Leiden, 2333 ZA, Netherlands
| | - Toon A B van Veen
- Department of Medical Physiology, University Medical Center Utrecht, 3584 CM, Netherlands
| | - Carol Ann Remme
- Department of Clinical and Experimental Cardiology, University Medical Center Amsterdam, 1105 AZ, Netherlands
| | - Milena Bellin
- Department of Anatomy and Embryology, University Medical Center, Leiden, 2333 ZA, Netherlands
| | - Eva van Rooij
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3584 CT, Netherlands
- Department of Cardiology, University Medical Center Utrecht, 3584 CX, Netherlands
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21
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Leybaert L, De Smet MA, Lissoni A, Allewaert R, Roderick HL, Bultynck G, Delmar M, Sipido KR, Witschas K. Connexin hemichannels as candidate targets for cardioprotective and anti-arrhythmic treatments. J Clin Invest 2023; 133:168117. [PMID: 36919695 PMCID: PMC10014111 DOI: 10.1172/jci168117] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023] Open
Abstract
Connexins are crucial cardiac proteins that form hemichannels and gap junctions. Gap junctions are responsible for the propagation of electrical and chemical signals between myocardial cells and cells of the specialized conduction system in order to synchronize the cardiac cycle and steer cardiac pump function. Gap junctions are normally open, while hemichannels are closed, but pathological circumstances may close gap junctions and open hemichannels, thereby perturbing cardiac function and homeostasis. Current evidence demonstrates an emerging role of hemichannels in myocardial ischemia and arrhythmia, and tools are now available to selectively inhibit hemichannels without inhibiting gap junctions as well as to stimulate hemichannel incorporation into gap junctions. We review available experimental evidence for hemichannel contributions to cellular pro-arrhythmic events in ventricular and atrial cardiomyocytes, and link these to insights at the level of molecular control of connexin-43-based hemichannel opening. We conclude that a double-edged approach of both preventing hemichannel opening and preserving gap junctional function will be key for further research and development of new connexin-based experimental approaches for treating heart disease.
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Affiliation(s)
- Luc Leybaert
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Maarten Aj De Smet
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Alessio Lissoni
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Rosalie Allewaert
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - H Llewelyn Roderick
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, and
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Mario Delmar
- Leon H. Charney Division of Cardiology, School of Medicine, New York University, New York, USA
| | - Karin R Sipido
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, and
| | - Katja Witschas
- Physiology Group, Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
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22
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Vallverdú-Prats M, Carreras D, Pérez GJ, Campuzano O, Brugada R, Alcalde M. Alterations in Calcium Handling Are a Common Feature in an Arrhythmogenic Cardiomyopathy Cell Model Triggered by Desmosome Genes Loss. Int J Mol Sci 2023; 24:ijms24032109. [PMID: 36768439 PMCID: PMC9917020 DOI: 10.3390/ijms24032109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/11/2023] [Accepted: 01/13/2023] [Indexed: 01/25/2023] Open
Abstract
Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiac disease characterized by fibrofatty replacement of the myocardium. Deleterious variants in desmosomal genes are the main cause of ACM and lead to common and gene-specific molecular alterations, which are not yet fully understood. This article presents the first systematic in vitro study describing gene and protein expression alterations in desmosomes, electrical conduction-related genes, and genes involved in fibrosis and adipogenesis. Moreover, molecular and functional alterations in calcium handling were also characterized. This study was performed d with HL1 cells with homozygous knockouts of three of the most frequently mutated desmosomal genes in ACM: PKP2, DSG2, and DSC2 (generated by CRISPR/Cas9). Moreover, knockout and N-truncated clones of DSP were also included. Our results showed functional alterations in calcium handling, a slower calcium re-uptake was observed in the absence of PKP2, DSG2, and DSC2, and the DSP knockout clone showed a more rapid re-uptake. We propose that the described functional alterations of the calcium handling genes may be explained by mRNA expression levels of ANK2, CASQ2, ATP2A2, RYR2, and PLN. In conclusion, the loss of desmosomal genes provokes alterations in calcium handling, potentially contributing to the development of arrhythmogenic events in ACM.
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Affiliation(s)
- Marta Vallverdú-Prats
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, 17190 Salt, Spain
| | - David Carreras
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, 17190 Salt, Spain
| | - Guillermo J. Pérez
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, 17190 Salt, Spain
- Department of Medical Sciences, Universitat de Girona, 17003 Girona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 21005 Madrid, Spain
| | - Oscar Campuzano
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, 17190 Salt, Spain
- Department of Medical Sciences, Universitat de Girona, 17003 Girona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 21005 Madrid, Spain
| | - Ramon Brugada
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, 17190 Salt, Spain
- Department of Medical Sciences, Universitat de Girona, 17003 Girona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 21005 Madrid, Spain
- Hospital Josep Trueta, 17007 Girona, Spain
| | - Mireia Alcalde
- Cardiovascular Genetics Center, Biomedical Research Institute of Girona, 17190 Salt, Spain
- Correspondence: ; Tel.: +872-98-70-87
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23
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Pun R, Kim MH, North BJ. Role of Connexin 43 phosphorylation on Serine-368 by PKC in cardiac function and disease. Front Cardiovasc Med 2023; 9:1080131. [PMID: 36712244 PMCID: PMC9877470 DOI: 10.3389/fcvm.2022.1080131] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/19/2022] [Indexed: 01/13/2023] Open
Abstract
Intercellular communication mediated by gap junction channels and hemichannels composed of Connexin 43 (Cx43) is vital for the propagation of electrical impulses through cardiomyocytes. The carboxyl terminal tail of Cx43 undergoes various post-translational modifications including phosphorylation of its Serine-368 (S368) residue. Protein Kinase C isozymes directly phosphorylate S368 to alter Cx43 function and stability through inducing conformational changes affecting channel permeability or promoting internalization and degradation to reduce intercellular communication between cardiomyocytes. Recent studies have implicated this PKC/Cx43-pS368 circuit in several cardiac-associated diseases. In this review, we describe the molecular and cellular basis of PKC-mediated Cx43 phosphorylation and discuss the implications of Cx43 S368 phosphorylation in the context of various cardiac diseases, such as cardiomyopathy, as well as the therapeutic potential of targeting this pathway.
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Affiliation(s)
- Renju Pun
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States
| | - Michael H. Kim
- CHI Health Heart Institute, School of Medicine, Creighton University, Omaha, NE, United States
| | - Brian J. North
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States,*Correspondence: Brian J. North,
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24
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Hypertensive Nephropathy: Unveiling the Possible Involvement of Hemichannels and Pannexons. Int J Mol Sci 2022; 23:ijms232415936. [PMID: 36555574 PMCID: PMC9785367 DOI: 10.3390/ijms232415936] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Hypertension is one of the most common risk factors for developing chronic cardiovascular diseases, including hypertensive nephropathy. Within the glomerulus, hypertension causes damage and activation of mesangial cells (MCs), eliciting the production of large amounts of vasoactive and proinflammatory agents. Accordingly, the activation of AT1 receptors by the vasoactive molecule angiotensin II (AngII) contributes to the pathogenesis of renal damage, which is mediated mostly by the dysfunction of intracellular Ca2+ ([Ca2+]i) signaling. Similarly, inflammation entails complex processes, where [Ca2+]i also play crucial roles. Deregulation of this second messenger increases cell damage and promotes fibrosis, reduces renal blood flow, and impairs the glomerular filtration barrier. In vertebrates, [Ca2+]i signaling depends, in part, on the activity of two families of large-pore channels: hemichannels and pannexons. Interestingly, the opening of these channels depends on [Ca2+]i signaling. In this review, we propose that the opening of channels formed by connexins and/or pannexins mediated by AngII induces the ATP release to the extracellular media, with the subsequent activation of purinergic receptors. This process could elicit Ca2+ overload and constitute a feed-forward mechanism, leading to kidney damage.
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25
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Maione AS, Faris P, Iengo L, Catto V, Bisonni L, Lodola F, Negri S, Casella M, Guarino A, Polvani G, Cerrone M, Tondo C, Pompilio G, Sommariva E, Moccia F. Ca2+ dysregulation in cardiac stromal cells sustains fibro-adipose remodeling in Arrhythmogenic Cardiomyopathy and can be modulated by flecainide. J Transl Med 2022; 20:522. [DOI: 10.1186/s12967-022-03742-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/30/2022] [Indexed: 11/15/2022] Open
Abstract
Abstract
Background
Cardiac mesenchymal stromal cells (C-MSC) were recently shown to differentiate into adipocytes and myofibroblasts to promote the aberrant remodeling of cardiac tissue that characterizes arrhythmogenic cardiomyopathy (ACM). A calcium (Ca2+) signaling dysfunction, mainly demonstrated in mouse models, is recognized as a mechanism impacting arrhythmic risk in ACM cardiomyocytes. Whether similar mechanisms influence ACM C-MSC fate is still unknown.
Thus, we aim to ascertain whether intracellular Ca2+ oscillations and the Ca2+ toolkit are altered in human C-MSC obtained from ACM patients, and to assess their link with C-MSC-specific ACM phenotypes.
Methods and results
ACM C-MSC show enhanced spontaneous Ca2+ oscillations and concomitant increased Ca2+/Calmodulin dependent kinase II (CaMKII) activation compared to control cells. This is manly linked to a constitutive activation of Store-Operated Ca2+ Entry (SOCE), which leads to enhanced Ca2+ release from the endoplasmic reticulum through inositol-1,4,5-trisphosphate receptors. By targeting the Ca2+ handling machinery or CaMKII activity, we demonstrated a causative link between Ca2+ oscillations and fibro-adipogenic differentiation of ACM C-MSC. Genetic silencing of the desmosomal gene PKP2 mimics the remodelling of the Ca2+ signalling machinery occurring in ACM C-MSC. The anti-arrhythmic drug flecainide inhibits intracellular Ca2+ oscillations and fibro-adipogenic differentiation by selectively targeting SOCE.
Conclusions
Altogether, our results extend the knowledge of Ca2+ dysregulation in ACM to the stromal compartment, as an etiologic mechanism of C-MSC-related ACM phenotypes. A new mode of action of flecainide on a novel mechanistic target is unveiled against the fibro-adipose accumulation in ACM.
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26
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Zhang B, Zhou C, Liu J, Zhang J, Jiang C, Tang M, Xie J, Wu Y, Xie X, Li X, Yu J, Wang X, Cheng D, Zhou J, Chen Z, Fan F, Zhou X, Tao A, Yang B. Impaired heart rate variability in patients with arrhythmogenic cardiomyopathy: A multicenter retrospective study in China. Front Cardiovasc Med 2022; 9:1044797. [PMID: 36386351 PMCID: PMC9659603 DOI: 10.3389/fcvm.2022.1044797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/10/2022] [Indexed: 10/21/2023] Open
Abstract
BACKGROUND Cardiac sympathetic nerve system (SNS) might play an important role in arrhythmogenesis of arrhythmogenic cardiomyopathy (ACM). This study aims to assess the activity of cardiac SNS in ACM patients by heart rate variability (HRV), and to investigate its predictive value for sustained ventricular tachycardia (sVT). METHODS A total of 88 ACM patients and 65 sex- and age- matched healthy participants were enrolled. The time domain measures were used to evaluate the activity of cardiac SNS. An independent cohort with 48 ACM patients was as the validation cohort. RESULTS ACM patients had lower levels of standard deviation of all NN intervals (SDNN) [118.0 (90.3, 136.8) vs. 152.0 (132.5, 174.5) ms, p < 0.001] compared with healthy participants. Further analysis showed ACM patients with sVT had lower levels of SDNN than those without sVT (105.0 ± 28.1 vs. 131.8 ± 33.1 ms, p < 0.001). Multivariate logistic regression analysis showed SDNN was independently associated with sVT in ACM patients [odds ratio (OR) 0.59, 95% confidence interval (CI) (0.45-0.78), p < 0.001]. Receiver operating characteristics curve demonstrated SDNN had clinical values in predicting sVT in ACM patients [area under the curve (AUC) = 0.73, 95% CI (0.63-0.84), p < 0.001], which was verified in the validation cohort. CONCLUSION The present study suggests that HRV is impaired in patients with ACM, and the SDNN level has a moderate value in risk stratification for sVT in ACM patients. In addition, the finding might provide new target for the further management of ACM with integrated traditional Chinese and western medicine.
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Affiliation(s)
- Baowei Zhang
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Chunjiang Zhou
- Center of Cardiology, Shanghai East Hospital, Nanjing Medical University, Shanghai, China
| | - Jinqiu Liu
- Department of Cardiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Jinlin Zhang
- Department of Cardiology, Wuhan Asia Heart Hospital, Wuhan, China
| | - Chenyang Jiang
- Department of Cardiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Min Tang
- Department of Cardiology, State Key Laboratory of Cardiovascular Disease, Cardiovascular Institute, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jiaxi Xie
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yizhang Wu
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xin Xie
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xiaorong Li
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jinbo Yu
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xuecheng Wang
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Dian Cheng
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jian Zhou
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Zijun Chen
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Fenghua Fan
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xiujuan Zhou
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Aibin Tao
- Department of Cardiology, The Affiliated People’s Hospital of Jiangsu University, Zhenjiang, China
| | - Bing Yang
- Center of Cardiology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
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27
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Vasireddi SK, Sattayaprasert P, Yang D, Dennis AT, Bektik E, Fu JD, Mackall JA, Laurita KR. Adipogenic Signaling Promotes Arrhythmia Substrates before Structural Abnormalities in TMEM43 ARVC. J Pers Med 2022; 12:1680. [PMID: 36294819 PMCID: PMC9604824 DOI: 10.3390/jpm12101680] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/26/2022] [Accepted: 09/29/2022] [Indexed: 11/06/2022] Open
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder of desmosomal and structural proteins that is characterized by fibro-fatty infiltrate in the ventricles and fatal arrhythmia that can occur early before significant structural abnormalities. Most ARVC mutations interfere with β-catenin-dependent transcription that enhances adipogenesis; however, the mechanistic pathway to arrhythmogenesis is not clear. We hypothesized that adipogenic conditions play an important role in the formation of arrhythmia substrates in ARVC. Cardiac myocyte monolayers co-cultured for 2-4 days with mesenchymal stem cells (MSC) were derived from human-induced pluripotent stem cells with the ARVC5 TMEM43 p.Ser358Leu mutation. The TMEM43 mutation in myocyte co-cultures alone had no significant effect on impulse conduction velocity (CV) or APD. In contrast, when co-cultures were exposed to pro-adipogenic factors for 2-4 days, CV and APD were significantly reduced compared to controls by 49% and 31%, respectively without evidence of adipogenesis. Additionally, these arrhythmia substrates coincided with a significant reduction in IGF-1 expression in MSCs and were mitigated by IGF-1 treatment. These findings suggest that the onset of enhanced adipogenic signaling may be a mechanism of early arrhythmogenesis, which could lead to personalized treatment for arrhythmias associated with TMEM43 and other ARVC mutations.
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Affiliation(s)
- Sunil K. Vasireddi
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, OH 44106, USA
- Stanford Cardiovascular Institute, Department of Medicine, Stanford University, Palo Alto, CA 94305, USA
| | | | - Dandan Yang
- The Dorothy M. Davis Heart and Lung Research Institute, Frick Center for Heart Failure and Arrhythmia, Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Adrienne T. Dennis
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Emre Bektik
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Ji-dong Fu
- The Dorothy M. Davis Heart and Lung Research Institute, Frick Center for Heart Failure and Arrhythmia, Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Judith A. Mackall
- Harrington Heart and Vascular Institute, University Hospitals Cleveland Medical Center, Cleveland, OH 44106, USA
| | - Kenneth R. Laurita
- Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, OH 44106, USA
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Laurita KR, Vasireddi SK, Mackall JA. Elucidating arrhythmogenic right ventricular cardiomyopathy with stem cells. Birth Defects Res 2022; 114:948-958. [PMID: 35396927 PMCID: PMC9790231 DOI: 10.1002/bdr2.2010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 03/17/2022] [Accepted: 03/23/2022] [Indexed: 12/31/2022]
Abstract
Human stems cells have sparked many novel strategies for treating heart disease and for elucidating their underlying mechanisms. For example, arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle disorder that is associated with fatal arrhythmias often occurring in healthy young adults. Fibro-fatty infiltrate, a clinical hallmark, progresses with the disease and can develop across both ventricles. Pathogenic variants in genes have been identified, with most being responsible for encoding cardiac desmosome proteins that reside at myocyte boundaries that are critical for cell-to-cell coupling. Despite some understanding of the molecular signaling mechanisms associated with ARVC mutations, their relationship with arrhythmogenesis is complex and not well understood for a monogenetic disorder. This review article focuses on arrhythmia mechanisms in ARVC based on clinical and animal studies and their relationship with disease causing variants. We also discuss the ways in which stem cells can be leveraged to improve our understanding of the role cardiac myocytes, nonmyocytes, metabolic signals, and inflammatory mediators play in an early onset disease such as ARVC.
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Affiliation(s)
- Kenneth R. Laurita
- Heart and Vascular Research CenterMetroHealth Campus, Case Western Reserve UniversityClevelandOhioUSA
| | - Sunil K. Vasireddi
- Stanford Cardiovascular Institute, Department of MedicineStanford UniversityCaliforniaUSA
| | - Judith A. Mackall
- Harrington Heart and Vascular InstituteUniversity Hospitals Cleveland Medical Center, Case Western Reserve UniversityClevelandOhioUSA
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Stevens TL, Manring HR, Wallace MJ, Argall A, Dew T, Papaioannou P, Antwi-Boasiako S, Xu X, Campbell SG, Akar FG, Borzok MA, Hund TJ, Mohler PJ, Koenig SN, El Refaey M. Humanized Dsp ACM Mouse Model Displays Stress-Induced Cardiac Electrical and Structural Phenotypes. Cells 2022; 11:3049. [PMID: 36231013 PMCID: PMC9562631 DOI: 10.3390/cells11193049] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/17/2022] [Accepted: 09/22/2022] [Indexed: 11/16/2022] Open
Abstract
Arrhythmogenic cardiomyopathy (ACM) is an inherited disorder characterized by fibro-fatty infiltration with an increased propensity for ventricular arrhythmias and sudden death. Genetic variants in desmosomal genes are associated with ACM. Incomplete penetrance is a common feature in ACM families, complicating the understanding of how external stressors contribute towards disease development. To analyze the dual role of genetics and external stressors on ACM progression, we developed one of the first mouse models of ACM that recapitulates a human variant by introducing the murine equivalent of the human R451G variant into endogenous desmoplakin (DspR451G/+). Mice homozygous for this variant displayed embryonic lethality. While DspR451G/+ mice were viable with reduced expression of DSP, no presentable arrhythmogenic or structural phenotypes were identified at baseline. However, increased afterload resulted in reduced cardiac performance, increased chamber dilation, and accelerated progression to heart failure. In addition, following catecholaminergic challenge, DspR451G/+ mice displayed frequent and prolonged arrhythmic events. Finally, aberrant localization of connexin-43 was noted in the DspR451G/+ mice at baseline, becoming more apparent following cardiac stress via pressure overload. In summary, cardiovascular stress is a key trigger for unmasking both electrical and structural phenotypes in one of the first humanized ACM mouse models.
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Affiliation(s)
- Tyler L. Stevens
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
- Department of Physiology and Cellular Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
| | - Heather R. Manring
- Comprehensive Cancer Center, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
| | - Michael J. Wallace
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
- Department of Physiology and Cellular Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
| | - Aaron Argall
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
- Department of Physiology and Cellular Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
| | - Trevor Dew
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
- Department of Physiology and Cellular Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
| | - Peter Papaioannou
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
- Department of Surgery, Division of Cardiac Surgery, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
| | - Steve Antwi-Boasiako
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Xianyao Xu
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Stuart G. Campbell
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Fadi G. Akar
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
- Department of Internal Medicine, Section of Cardiovascular Medicine, Yale School of Medicine, New Haven, CT 06520, USA
| | - Maegen A. Borzok
- Biochemistry, Chemistry, Engineering, and Physics Department, Commonwealth University of Pennsylvania, Mansfield, PA 16933, USA
| | - Thomas J. Hund
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH 43210, USA
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
| | - Peter J. Mohler
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
- Department of Physiology and Cellular Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
| | - Sara N. Koenig
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
| | - Mona El Refaey
- Frick Center for Heart Failure and Arrhythmia Research, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
- Department of Surgery, Division of Cardiac Surgery, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH 43210, USA
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Pérez-Hernández M, van Opbergen CJM, Bagwan N, Vissing CR, Marrón-Liñares GM, Zhang M, Torres Vega E, Sorrentino A, Drici L, Sulek K, Zhai R, Hansen FB, Christensen AH, Boesgaard S, Gustafsson F, Rossing K, Small EM, Davies MJ, Rothenberg E, Sato PY, Cerrone M, Jensen THL, Qvortrup K, Bundgaard H, Delmar M, Lundby A. Loss of Nuclear Envelope Integrity and Increased Oxidant Production Cause DNA Damage in Adult Hearts Deficient in PKP2: A Molecular Substrate of ARVC. Circulation 2022; 146:851-867. [PMID: 35959657 PMCID: PMC9474627 DOI: 10.1161/circulationaha.122.060454] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 06/30/2022] [Indexed: 01/24/2023]
Abstract
BACKGROUND Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by high propensity to life-threatening arrhythmias and progressive loss of heart muscle. More than 40% of reported genetic variants linked to ARVC reside in the PKP2 gene, which encodes the PKP2 protein (plakophilin-2). METHODS We describe a comprehensive characterization of the ARVC molecular landscape as determined by high-resolution mass spectrometry, RNA sequencing, and transmission electron microscopy of right ventricular biopsy samples obtained from patients with ARVC with PKP2 mutations and left ventricular ejection fraction >45%. Samples from healthy relatives served as controls. The observations led to experimental work using multiple imaging and biochemical techniques in mice with a cardiac-specific deletion of Pkp2 studied at a time of preserved left ventricular ejection fraction and in human induced pluripotent stem cell-derived PKP2-deficient myocytes. RESULTS Samples from patients with ARVC present a loss of nuclear envelope integrity, molecular signatures indicative of increased DNA damage, and a deficit in transcripts coding for proteins in the electron transport chain. Mice with a cardiac-specific deletion of Pkp2 also present a loss of nuclear envelope integrity, which leads to DNA damage and subsequent excess oxidant production (O2.- and H2O2), the latter increased further under mechanical stress (isoproterenol or exercise). Increased oxidant production and DNA damage is recapitulated in human induced pluripotent stem cell-derived PKP2-deficient myocytes. Furthermore, PKP2-deficient cells release H2O2 into the extracellular environment, causing DNA damage and increased oxidant production in neighboring myocytes in a paracrine manner. Treatment with honokiol increases SIRT3 (mitochondrial nicotinamide adenine dinucleotide-dependent protein deacetylase sirtuin-3) activity, reduces oxidant levels and DNA damage in vitro and in vivo, reduces collagen abundance in the right ventricular free wall, and has a protective effect on right ventricular function. CONCLUSIONS Loss of nuclear envelope integrity and subsequent DNA damage is a key substrate in the molecular pathology of ARVC. We show transcriptional downregulation of proteins of the electron transcript chain as an early event in the molecular pathophysiology of the disease (before loss of left ventricular ejection fraction <45%), which associates with increased oxidant production (O2.- and H2O2). We propose therapies that limit oxidant formation as a possible intervention to restrict DNA damage in ARVC.
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Affiliation(s)
- Marta Pérez-Hernández
- The Leon H. Charney Division of Cardiology, NYU-Grossman School of Medicine, New York (M.P.-H., C.J.M.v.O., G.M.M.-L., M.Z., M.C., M.D.)
| | - Chantal J M van Opbergen
- The Leon H. Charney Division of Cardiology, NYU-Grossman School of Medicine, New York (M.P.-H., C.J.M.v.O., G.M.M.-L., M.Z., M.C., M.D.)
| | - Navratan Bagwan
- Department of Biomedical Sciences (N.B., E.T.V., A.S., F.B.H., M.J.D., K.Q., A.L.), University of Copenhagen, Denmark
| | - Christoffer Rasmus Vissing
- Faculty of Health and Medical Sciences, and Department of Clinical Medicine (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.), University of Copenhagen, Denmark
- Department of Cardiology, The Heart Centre, Rigshospitalet, Copenhagen, Denmark (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.)
| | - Grecia M Marrón-Liñares
- The Leon H. Charney Division of Cardiology, NYU-Grossman School of Medicine, New York (M.P.-H., C.J.M.v.O., G.M.M.-L., M.Z., M.C., M.D.)
| | - Mingliang Zhang
- The Leon H. Charney Division of Cardiology, NYU-Grossman School of Medicine, New York (M.P.-H., C.J.M.v.O., G.M.M.-L., M.Z., M.C., M.D.)
| | - Estefania Torres Vega
- Department of Biomedical Sciences (N.B., E.T.V., A.S., F.B.H., M.J.D., K.Q., A.L.), University of Copenhagen, Denmark
| | - Andrea Sorrentino
- Department of Biomedical Sciences (N.B., E.T.V., A.S., F.B.H., M.J.D., K.Q., A.L.), University of Copenhagen, Denmark
| | - Lylia Drici
- The Novo Nordisk Foundation Center for Protein Research (L.D., K.S.), University of Copenhagen, Denmark
| | - Karolina Sulek
- The Novo Nordisk Foundation Center for Protein Research (L.D., K.S.), University of Copenhagen, Denmark
| | - Ruxu Zhai
- College of Medicine, Drexel University, Philadelphia, PA (R.Z., P.Y.S.)
| | - Finn B Hansen
- Department of Biomedical Sciences (N.B., E.T.V., A.S., F.B.H., M.J.D., K.Q., A.L.), University of Copenhagen, Denmark
| | - Alex H Christensen
- Faculty of Health and Medical Sciences, and Department of Clinical Medicine (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.), University of Copenhagen, Denmark
- Department of Cardiology, The Heart Centre, Rigshospitalet, Copenhagen, Denmark (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.)
- Department of Cardiology, Copenhagen University Hospital-Herlev-Gentofte Hospital, Denmark (A.H.C.)
| | - Søren Boesgaard
- Department of Cardiology, The Heart Centre, Rigshospitalet, Copenhagen, Denmark (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.)
- College of Medicine, Drexel University, Philadelphia, PA (R.Z., P.Y.S.)
| | - Finn Gustafsson
- Faculty of Health and Medical Sciences, and Department of Clinical Medicine (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.), University of Copenhagen, Denmark
- Department of Cardiology, The Heart Centre, Rigshospitalet, Copenhagen, Denmark (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.)
| | - Kasper Rossing
- Faculty of Health and Medical Sciences, and Department of Clinical Medicine (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.), University of Copenhagen, Denmark
- Department of Cardiology, The Heart Centre, Rigshospitalet, Copenhagen, Denmark (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.)
| | - Eric M Small
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, NY (E.M.S.)
| | - Michael J Davies
- Department of Biomedical Sciences (N.B., E.T.V., A.S., F.B.H., M.J.D., K.Q., A.L.), University of Copenhagen, Denmark
| | - Eli Rothenberg
- Division of Pharmacology, NYU School of Medicine, New York (E.R.)
| | - Priscila Y Sato
- College of Medicine, Drexel University, Philadelphia, PA (R.Z., P.Y.S.)
| | - Marina Cerrone
- The Leon H. Charney Division of Cardiology, NYU-Grossman School of Medicine, New York (M.P.-H., C.J.M.v.O., G.M.M.-L., M.Z., M.C., M.D.)
| | - Thomas Hartvig Lindkær Jensen
- Faculty of Health and Medical Sciences, and Department of Clinical Medicine (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.), University of Copenhagen, Denmark
- Department of Cardiology, The Heart Centre, Rigshospitalet, Copenhagen, Denmark (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.)
| | - Klaus Qvortrup
- Department of Biomedical Sciences (N.B., E.T.V., A.S., F.B.H., M.J.D., K.Q., A.L.), University of Copenhagen, Denmark
| | - Henning Bundgaard
- Faculty of Health and Medical Sciences, and Department of Clinical Medicine (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.), University of Copenhagen, Denmark
- Department of Cardiology, The Heart Centre, Rigshospitalet, Copenhagen, Denmark (C.R.V., A.H.C., S.B., F.G., K.R., T.H.L.J., H.B.)
| | - Mario Delmar
- The Leon H. Charney Division of Cardiology, NYU-Grossman School of Medicine, New York (M.P.-H., C.J.M.v.O., G.M.M.-L., M.Z., M.C., M.D.)
| | - Alicia Lundby
- Department of Biomedical Sciences (N.B., E.T.V., A.S., F.B.H., M.J.D., K.Q., A.L.), University of Copenhagen, Denmark
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31
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Boengler K, Leybaert L, Ruiz-Meana M, Schulz R. Connexin 43 in Mitochondria: What Do We Really Know About Its Function? Front Physiol 2022; 13:928934. [PMID: 35860665 PMCID: PMC9289461 DOI: 10.3389/fphys.2022.928934] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/26/2022] [Indexed: 01/04/2023] Open
Abstract
Connexins are known for their ability to mediate cell-cell communication via gap junctions and also form hemichannels that pass ions and molecules over the plasma membrane when open. Connexins have also been detected within mitochondria, with mitochondrial connexin 43 (Cx43) being the best studied to date. In this review, we discuss evidence for Cx43 presence in mitochondria of cell lines, primary cells and organs and summarize data on its localization, import and phosphorylation status. We further highlight the influence of Cx43 on mitochondrial function in terms of respiration, opening of the mitochondrial permeability transition pore and formation of reactive oxygen species, and also address the presence of a truncated form of Cx43 termed Gja1-20k. Finally, the role of mitochondrial Cx43 in pathological conditions, particularly in the heart, is discussed.
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Affiliation(s)
- Kerstin Boengler
- Institute of Physiology, Justus-Liebig University, Giessen, Germany
| | - Luc Leybaert
- Department of Basic and Applied Medical Sciences—Physiology Group, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Marisol Ruiz-Meana
- Cardiovascular Diseases Research Group, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Barcelona, Spain
| | - Rainer Schulz
- Institute of Physiology, Justus-Liebig University, Giessen, Germany
- *Correspondence: Rainer Schulz,
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Burboa PC, Puebla M, Gaete PS, Durán WN, Lillo MA. Connexin and Pannexin Large-Pore Channels in Microcirculation and Neurovascular Coupling Function. Int J Mol Sci 2022; 23:ijms23137303. [PMID: 35806312 PMCID: PMC9266979 DOI: 10.3390/ijms23137303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 01/27/2023] Open
Abstract
Microcirculation homeostasis depends on several channels permeable to ions and/or small molecules that facilitate the regulation of the vasomotor tone, hyperpermeability, the blood–brain barrier, and the neurovascular coupling function. Connexin (Cxs) and Pannexin (Panxs) large-pore channel proteins are implicated in several aspects of vascular physiology. The permeation of ions (i.e., Ca2+) and key metabolites (ATP, prostaglandins, D-serine, etc.) through Cxs (i.e., gap junction channels or hemichannels) and Panxs proteins plays a vital role in intercellular communication and maintaining vascular homeostasis. Therefore, dysregulation or genetic pathologies associated with these channels promote deleterious tissue consequences. This review provides an overview of current knowledge concerning the physiological role of these large-pore molecule channels in microcirculation (arterioles, capillaries, venules) and in the neurovascular coupling function.
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Affiliation(s)
- Pía C. Burboa
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, 185 South Orange Avenue, Newark, NJ 07103, USA; (P.C.B.); (W.N.D.)
- Departamento de Morfología y Función, Facultad de Salud y Ciencias Sociales, Sede Santiago Centro, Universidad de las Américas, Avenue República 71, Santiago 8370040, Chile;
| | - Mariela Puebla
- Departamento de Morfología y Función, Facultad de Salud y Ciencias Sociales, Sede Santiago Centro, Universidad de las Américas, Avenue República 71, Santiago 8370040, Chile;
| | - Pablo S. Gaete
- Department of Physiology and Membrane Biology, University of California at Davis, Davis, CA 95616, USA;
| | - Walter N. Durán
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, 185 South Orange Avenue, Newark, NJ 07103, USA; (P.C.B.); (W.N.D.)
- Rutgers School of Graduate Studies, 185 South Orange Avenue, Newark, NJ 07103, USA
| | - Mauricio A. Lillo
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, 185 South Orange Avenue, Newark, NJ 07103, USA; (P.C.B.); (W.N.D.)
- Correspondence:
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33
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van Opbergen CJM, Sall J, Petzold C, Dancel-Manning K, Delmar M, Liang FX. "Orphan" Connexin43 in Plakophilin-2 Deficient Hearts Revealed by Volume Electron Microscopy. Front Cell Dev Biol 2022; 10:843687. [PMID: 35663385 PMCID: PMC9159532 DOI: 10.3389/fcell.2022.843687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Previous studies revealed an abundance of functional Connexin43 (Cx43) hemichannels consequent to loss of plakophilin-2 (PKP2) expression in adult murine hearts. The increased Cx43-mediated membrane permeability is likely responsible for excess entry of calcium into the cells, leading to an arrhythmogenic/cardiomyopathic phenotype. The latter has translational implications to the molecular mechanisms of inheritable arrhythmogenic right ventricular cardiomyopathy (ARVC). Despite functional evidence, visualization of these "orphan" (i.e., non-paired in a gap junction configuration) Cx43 hemichannels remains lacking. Immuno-electron microscopy (IEM) remains an extremely powerful tool to localize, with nanometric resolution, a protein within its native structural landscape. Yet, challenges for IEM are to preserve the antigenicity of the molecular target and to provide access for antibodies to reach their target, while maintaining the cellular/tissue ultrastructure. Fixation is important for maintaining cell structure, but strong fixation and vigorous dehydration (as it is routine for EM) can alter protein structure, thus impairing antigen-antibody binding. Here, we implemented a method to combine pre-embedding immunolabeling (pre-embedding) with serial block-face scanning electron microscopy (SBF-SEM). We utilized a murine model of cardiomyocyte-specific, Tamoxifen (TAM) activated knockout of PKP2. Adult hearts were harvested 14 days post-TAM, at this time hearts present a phenotype of concealed ARVC (i.e., an arrhythmogenic phenotype but no overt structural disease). Thick (200 µm) vibratome slices were immunolabelled for Cx43 and treated with nanogold or FluoroNanogold, coupled with a silver enhancement. Left or right ventricular free walls were dissected and three-dimensional (3D) localization of Cx43 in cardiac muscle was performed using SBF-SEM. Reconstructed images allowed us to visualize the entire length of gap junction plaques, seen as two parallel, closely packed strings of Cx43-immunoreactive beads at the intercalated disc. In contrast, in PKP2-deficient hearts we observed bulging of the intercellular space, and entire areas where only one of the two strings could be observed, indicating the presence of orphan Cx43. We conclude that pre-embedding and SBF-SEM allowed visualization of cardiac Cx43 plaques in their native environment, providing for the first time a visual complement of functional data indicating the presence of orphan Cx43 hemichannels resulting from loss of desmosomal integrity in the heart.
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Affiliation(s)
- Chantal J M van Opbergen
- The Leon H. Charney Division of Cardiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Joseph Sall
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, United States
| | - Chris Petzold
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, United States
| | - Kristen Dancel-Manning
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, United States
| | - Mario Delmar
- The Leon H. Charney Division of Cardiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Feng-Xia Liang
- Microscopy Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, United States
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Zheng J, Dooge HC, Pérez-Hernández M, Zhao YT, Chen X, Hernandez JJ, Valdivia CR, Palomeque J, Rothenberg E, Delmar M, Valdivia HH, Alvarado FJ. Preserved cardiac performance and adrenergic response in a rabbit model with decreased ryanodine receptor 2 expression. J Mol Cell Cardiol 2022; 167:118-128. [PMID: 35413295 PMCID: PMC9610860 DOI: 10.1016/j.yjmcc.2022.04.004] [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: 10/20/2021] [Revised: 03/11/2022] [Accepted: 04/06/2022] [Indexed: 11/19/2022]
Abstract
Ryanodine receptor 2 (RyR2) is an ion channel in the heart responsible for releasing into the cytosol most of the Ca2+ required for contraction. Proper regulation of RyR2 is critical, as highlighted by the association between channel dysfunction and cardiac arrhythmia. Lower RyR2 expression is also observed in some forms of heart disease; however, there is limited information on the impact of this change on excitation-contraction (e-c) coupling, Ca2+-dependent arrhythmias, and cardiac performance. We used a constitutive knock-out of RyR2 in rabbits (RyR2-KO) to assess the extent to which a stable decrease in RyR2 expression modulates Ca2+ handling in the heart. We found that homozygous knock-out of RyR2 in rabbits is embryonic lethal. Remarkably, heterozygotes (KO+/-) show ~50% loss of RyR2 protein without developing an overt phenotype at the intact animal and whole heart levels. Instead, we found that KO+/- myocytes show (1) remodeling of RyR2 clusters, favoring smaller groups in which channels are more densely arranged; (2) lower Ca2+ spark frequency and amplitude; (3) slower rate of Ca2+ release and mild but significant desynchronization of the Ca2+ transient; and (4) a significant decrease in the basal phosphorylation of S2031, likely due to increased association between RyR2 and PP2A. Our data show that RyR2 deficiency, although remarkable at the molecular and subcellular level, has only a modest impact on global Ca2+ release and is fully compensated at the whole-heart level. This highlights the redundancy of RyR2 protein expression and the plasticity of the e-c coupling apparatus.
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Affiliation(s)
- Jingjing Zheng
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA; Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Holly C Dooge
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Marta Pérez-Hernández
- Leon H Charney Division of Cardiology, New York University Grossman School of Medicine,. New York, NY, United States of America
| | - Yan-Ting Zhao
- Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, United States of America
| | - Xi Chen
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States of America
| | - Jonathan J Hernandez
- Department of Pediatrics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, United States of America
| | - Carmen R Valdivia
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Julieta Palomeque
- Centro de Investigaciones Cardiovasculares, CCT-La Plata-CONICET, Facultad de Ciencias Médicas, UNLP, La Plata, Argentina
| | - Eli Rothenberg
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, United States of America
| | - Mario Delmar
- Leon H Charney Division of Cardiology, New York University Grossman School of Medicine,. New York, NY, United States of America
| | - Héctor H Valdivia
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Francisco J Alvarado
- Department of Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
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Sarcoplasmic Reticulum Ca2+ Dysregulation in the Pathophysiology of Inherited Arrhythmia: An Update. Biochem Pharmacol 2022; 200:115059. [DOI: 10.1016/j.bcp.2022.115059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 11/19/2022]
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van Opbergen CJM, Bagwan N, Maurya SR, Kim JC, Smith AN, Blackwell DJ, Johnston JN, Knollmann BC, Cerrone M, Lundby A, Delmar M. Exercise Causes Arrhythmogenic Remodeling of Intracellular Calcium Dynamics in Plakophilin-2-Deficient Hearts. Circulation 2022; 145:1480-1496. [PMID: 35491884 PMCID: PMC9086182 DOI: 10.1161/circulationaha.121.057757] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Exercise training, and catecholaminergic stimulation, increase the incidence of arrhythmic events in patients affected with arrhythmogenic right ventricular cardiomyopathy correlated with plakophilin-2 (PKP2) mutations. Separate data show that reduced abundance of PKP2 leads to dysregulation of intracellular Ca2+ (Ca2+i) homeostasis. Here, we study the relation between excercise, catecholaminergic stimulation, Ca2+i homeostasis, and arrhythmogenesis in PKP2-deficient murine hearts. METHODS Experiments were performed in myocytes from a cardiomyocyte-specific, tamoxifen-activated, PKP2 knockout murine line (PKP2cKO). For training, mice underwent 75 minutes of treadmill running once per day, 5 days each week for 6 weeks. We used multiple approaches including imaging, high-resolution mass spectrometry, electrocardiography, and pharmacological challenges to study the functional properties of cells/hearts in vitro and in vivo. RESULTS In myocytes from PKP2cKO animals, training increased sarcoplasmic reticulum Ca2+ load, increased the frequency and amplitude of spontaneous ryanodine receptor (ryanodine receptor 2)-mediated Ca2+ release events (sparks), and changed the time course of sarcomeric shortening. Phosphoproteomics analysis revealed that training led to hyperphosphorylation of phospholamban in residues 16 and 17, suggesting a catecholaminergic component. Isoproterenol-induced increase in Ca2+i transient amplitude showed a differential response to β-adrenergic blockade that depended on the purported ability of the blockers to reach intracellular receptors. Additional experiments showed significant reduction of isoproterenol-induced Ca2+i sparks and ventricular arrhythmias in PKP2cKO hearts exposed to an experimental blocker of ryanodine receptor 2 channels. CONCLUSIONS Exercise disproportionately affects Ca2+i homeostasis in PKP2-deficient hearts in a manner facilitated by stimulation of intracellular β-adrenergic receptors and hyperphosphorylation of phospholamban. These cellular changes create a proarrhythmogenic state that can be mitigated by ryanodine receptor 2 blockade. Our data unveil an arrhythmogenic mechanism for exercise-induced or catecholaminergic life-threatening arrhythmias in the setting of PKP2 deficit. We suggest that membrane-permeable β-blockers are potentially more efficient for patients with arrhythmogenic right ventricular cardiomyopathy, highlight the potential for ryanodine receptor 2 channel blockers as treatment for the control of heart rhythm in the population at risk, and propose that PKP2-dependent and phospholamban-dependent arrhythmogenic right ventricular cardiomyopathy-related arrhythmias have a common mechanism.
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Affiliation(s)
- Chantal JM van Opbergen
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, NY, USA
| | - Navratan Bagwan
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Svetlana R Maurya
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Joon-Chul Kim
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, NY, USA
| | - Abigail N Smith
- Department of Chemistry & Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
| | - Daniel J Blackwell
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jeffrey N Johnston
- Department of Chemistry & Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
| | - Björn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Marina Cerrone
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, NY, USA
| | - Alicia Lundby
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mario Delmar
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, NY, USA
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Camors EM, Roth AH, Alef JR, Sullivan RD, Johnson JN, Purevjav E, Towbin JA. Progressive Reduction in Right Ventricular Contractile Function Due to Altered Actin Expression in an Aging Mouse Model of Arrhythmogenic Cardiomyopathy. Circulation 2022; 145:1609-1624. [PMID: 35437032 DOI: 10.1161/circulationaha.120.049261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Arrhythmogenic cardiomyopathy (ACM) is an inherited genetic disorder of desmosomal dysfunction, and plakophilin-2 (PKP2) has been reported to be the most common disease-causing gene when mutation-positive. In the early "concealed" phase, the ACM heart is at high risk of sudden cardiac death before cardiac remodeling occurs due to mistargeted ion channels and altered Ca2+ handling. However, the results of pathogenic PKP2 variants on myocyte contraction in ACM pathogenesis remain unknown. METHODS We studied the outcomes of a human truncating variant of PKP2 on myocyte contraction using a novel knock-in mouse model with insertion of thymidine in exon 5 of Pkp2, which mimics a familial case of ACM (PKP2-L404fsX5). We used serial echocardiography, electrocardiography, blood pressure measurements, histology, cardiomyocyte contraction, intracellular calcium measurements, and gene and protein expression studies. RESULTS Serial echocardiography of Pkp2 heterozygous (Pkp2-Het) mice revealed progressive failure of the right ventricle (RV) in animals older than three months of age. By contrast, left ventricular (LV) function remained normal. Electrocardiograms of six-month-old anesthetized Pkp2-Het mice showed normal baseline heart rates and QRS complexes. Cardiac responses to β-adrenergic agonist isoproterenol (2 mg.kg-1) plus caffeine (120 mg.kg-1) were also normal. However, adrenergic stimulation enhanced the susceptibility of Pkp2-Het hearts to tachyarrhythmia and sudden cardiac death. Histologic staining showed no significant fibrosis or adipocyte infiltration in the RVs and LVs of six- and twelve-month-old Pkp2-Het hearts. Contractility assessment of isolated myocytes demonstrated progressively reduced Pkp2-Het RV cardiomyocyte function consistent with RV failure measured by echocardiography. However, aging Pkp2-Het and control RV myocytes loaded with intracellular Ca2+ indicator Fura-2 showed comparable Ca2+ transients. Western blotting of Pkp2-RV homogenates revealed a 40% decrease in actin, while actin immunoprecipitation followed by a 2, 4-dinitrophenylhydrazine staining showed doubled oxidation level. This correlated with a 39% increase in troponin-I phosphorylation. In contrast, Pkp2-Het LV myocytes had normal contraction, actin expression and oxidation, and troponin-I phosphorylation. Finally, Western blotting of cardiac biopsies revealed actin expression was 40% decreased in RVs of end-stage ACM patients. CONCLUSIONS During the early "concealed" phase of ACM, reduced actin expression drives loss of RV myocyte contraction, contributing to progressive RV dysfunction.
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Affiliation(s)
- Emmanuel M Camors
- Heart Institute, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN; Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN
| | - Alyson H Roth
- Heart Institute, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN; Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN
| | - Joseph R Alef
- Heart Institute, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN; Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN
| | - Ryan D Sullivan
- Department of Internal Medicine, University of Arizona College of Medicine, Phoenix, AR
| | - Jason N Johnson
- Heart Institute, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN; Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN; Pediatric Cardiology, St. Jude Children's Research Hospital, Memphis, TN
| | - Enkhsaikhan Purevjav
- Heart Institute, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN; Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN
| | - Jeffrey A Towbin
- Heart Institute, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN; Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN; Pediatric Cardiology, St. Jude Children's Research Hospital, Memphis, TN
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Arrhythmogenic Right Ventricular Cardiomyopathy. JACC Clin Electrophysiol 2022; 8:533-553. [PMID: 35450611 DOI: 10.1016/j.jacep.2021.12.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/09/2021] [Accepted: 12/14/2021] [Indexed: 01/21/2023]
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) encompasses a group of conditions characterized by right ventricular fibrofatty infiltration, with a predominant arrhythmic presentation. First described in the late 1970s and early 1980s, it is now frequently recognized to have biventricular involvement. The prevalence is ∼1:2,000 to 1:5,000, depending on geographic location, and it has a slight male predominance. The diagnosis of ARVC is determined on the basis of fulfillment of task force criteria incorporating electrophysiological parameters, cardiac imaging findings, genetic factors, and histopathologic features. Risk stratification of patients with ARVC aims to identify those who are at increased risk of sudden cardiac death or sustained ventricular tachycardia. Factors including age, sex, electrophysiological features, and cardiac imaging investigations all contribute to risk stratification. The current management of ARVC includes exercise restriction, β-blocker therapy, consideration for implantable cardioverter-defibrillator insertion, and catheter ablation. This review summarizes our current understanding of ARVC and provides clinicians with a practical approach to diagnosis and management.
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Cerrone M, Marrón-Liñares GM, van Opbergen CJM, Costa S, Bourfiss M, Pérez-Hernández M, Schlamp F, Sanchis-Gomar F, Malkani K, Drenkova K, Zhang M, Lin X, Heguy A, Velthuis BK, Prakken NHJ, LaGerche A, Calkins H, James CA, Te Riele ASJM, Delmar M. Role of plakophilin-2 expression on exercise-related progression of arrhythmogenic right ventricular cardiomyopathy: a translational study. Eur Heart J 2022; 43:1251-1264. [PMID: 34932122 PMCID: PMC8934688 DOI: 10.1093/eurheartj/ehab772] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/28/2021] [Accepted: 10/29/2021] [Indexed: 08/11/2023] Open
Abstract
AIMS Exercise increases arrhythmia risk and cardiomyopathy progression in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients, but the mechanisms remain unknown. We investigated transcriptomic changes caused by endurance training in mice deficient in plakophilin-2 (PKP2cKO), a desmosomal protein important for intercalated disc formation, commonly mutated in ARVC and controls. METHODS AND RESULTS Exercise alone caused transcriptional downregulation of genes coding intercalated disk proteins. The changes converged with those in sedentary and in exercised PKP2cKO mice. PKP2 loss caused cardiac contractile deficit, decreased muscle mass and increased functional/transcriptomic signatures of apoptosis, despite increased fractional shortening and calcium transient amplitude in single myocytes. Exercise accelerated cardiac dysfunction, an effect dampened by pre-training animals prior to PKP2-KO. Consistent with PKP2-dependent muscle mass deficit, cardiac dimensions in human athletes carrying PKP2 mutations were reduced, compared to matched controls. CONCLUSIONS We speculate that exercise challenges a cardiomyocyte "desmosomal reserve" which, if impaired genetically (e.g., PKP2 loss), accelerates progression of cardiomyopathy.
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Affiliation(s)
- Marina Cerrone
- The ‘Leon Charney’ Division of Cardiology, New York University Grossmann School of Medicine, 435 East 30th Street, NSB 707, New York, NY 10016, USA
| | - Grecia M Marrón-Liñares
- The ‘Leon Charney’ Division of Cardiology, New York University Grossmann School of Medicine, 435 East 30th Street, NSB 707, New York, NY 10016, USA
| | - Chantal J M van Opbergen
- The ‘Leon Charney’ Division of Cardiology, New York University Grossmann School of Medicine, 435 East 30th Street, NSB 707, New York, NY 10016, USA
| | - Sarah Costa
- Division of Cardiology, University Heart Center Zurich, Rämistrasse 100, Zurich CH-8091, Switzerland
| | - Mimount Bourfiss
- Department of Cardiology, Division of Heart and Lungs, University Medical Center Utrecht and The Netherlands Heart Institute, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Marta Pérez-Hernández
- The ‘Leon Charney’ Division of Cardiology, New York University Grossmann School of Medicine, 435 East 30th Street, NSB 707, New York, NY 10016, USA
| | - Florencia Schlamp
- The ‘Leon Charney’ Division of Cardiology, New York University Grossmann School of Medicine, 435 East 30th Street, NSB 707, New York, NY 10016, USA
| | - Fabian Sanchis-Gomar
- Department of Physiology, Faculty of Medicine, University of Valencia and INCLIVA Biomedical Research Institute, C. de Menéndez y Pelayo, 4, 46010 Valencia, Spain
| | - Kabir Malkani
- The ‘Leon Charney’ Division of Cardiology, New York University Grossmann School of Medicine, 435 East 30th Street, NSB 707, New York, NY 10016, USA
| | - Kamelia Drenkova
- The ‘Leon Charney’ Division of Cardiology, New York University Grossmann School of Medicine, 435 East 30th Street, NSB 707, New York, NY 10016, USA
| | - Mingliang Zhang
- The ‘Leon Charney’ Division of Cardiology, New York University Grossmann School of Medicine, 435 East 30th Street, NSB 707, New York, NY 10016, USA
| | - Xianming Lin
- The ‘Leon Charney’ Division of Cardiology, New York University Grossmann School of Medicine, 435 East 30th Street, NSB 707, New York, NY 10016, USA
| | - Adriana Heguy
- Genome Technology Center, Department of Pathology, New York University Grossmann School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Birgitta K Velthuis
- Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, the Netherlands
| | - Niek H J Prakken
- Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Andre LaGerche
- Clinical Research Domain, Baker Heart and Diabetes Institute, 75 Commercial Rd, Melbourne VIC 3004, Australia and National Centre for Sports Cardiology, St Vincent's Hospital Melbourne, Building C, 41 Victoria Parade, Fitzroy VIC 3065, Australia
| | - Hugh Calkins
- Division of Cardiology, Johns Hopkins Hospital, 1800 Orleans St, Baltimore, MD 21287, USA
| | - Cynthia A James
- Division of Cardiology, Johns Hopkins Hospital, 1800 Orleans St, Baltimore, MD 21287, USA
| | - Anneline S J M Te Riele
- Department of Cardiology, Division of Heart and Lungs, University Medical Center Utrecht and The Netherlands Heart Institute, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Mario Delmar
- The ‘Leon Charney’ Division of Cardiology, New York University Grossmann School of Medicine, 435 East 30th Street, NSB 707, New York, NY 10016, USA
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Sorrentino A, Bagwan N, Linscheid N, Poulsen PC, Kahnert K, Thomsen MB, Delmar M, Lundby A. Beta-blocker/ACE inhibitor therapy differentially impacts the steady state signaling landscape of failing and non-failing hearts. Sci Rep 2022; 12:4760. [PMID: 35306519 PMCID: PMC8934364 DOI: 10.1038/s41598-022-08534-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 03/09/2022] [Indexed: 11/25/2022] Open
Abstract
Heart failure is a multifactorial disease that affects an estimated 38 million people worldwide. Current pharmacotherapy of heart failure with reduced ejection fraction (HFrEF) includes combination therapy with angiotensin-converting enzyme inhibitors (ACEi) and β-adrenergic receptor blockers (β-AR blockers), a therapy also used as treatment for non-cardiac conditions. Our knowledge of the molecular changes accompanying treatment with ACEi and β-AR blockers is limited. Here, we applied proteomics and phosphoproteomics approaches to profile the global changes in protein abundance and phosphorylation state in cardiac left ventricles consequent to combination therapy of β-AR blocker and ACE inhibitor in HFrEF and control hearts. The phosphorylation changes induced by treatment were profoundly different for failing than for non-failing hearts. HFrEF was characterized by profound downregulation of mitochondrial proteins coupled with derangement of β-adrenergic and pyruvate dehydrogenase signaling. Upon treatment, phosphorylation changes consequent to HFrEF were reversed. In control hearts, treatment mainly led to downregulation of canonical PKA signaling. The observation of divergent signaling outcomes depending on disease state underscores the importance of evaluating drug effects within the context of the specific conditions present in the recipient heart.
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Wei X, Chang ACH, Chang H, Xu S, Xue Y, Zhang Y, Lei M, Chang ACY, Zhang Q. Hypoglycemia-Exacerbated Mitochondrial Connexin 43 Accumulation Aggravates Cardiac Dysfunction in Diabetic Cardiomyopathy. Front Cardiovasc Med 2022; 9:800185. [PMID: 35369285 PMCID: PMC8967291 DOI: 10.3389/fcvm.2022.800185] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 02/10/2022] [Indexed: 11/29/2022] Open
Abstract
Background Diabetic cardiomyopathy (DCM) is a complex multifaceted disease responsible for elevated heart failure (HF) morbidity and mortality in patients with diabetes mellitus (DM). Patients with DCM exhibit subclinical diastolic dysfunction, progression toward systolic impairment, and abnormal electrophysiology. Hypoglycemia events that occur spontaneously or due to excess insulin administration threaten the lives of patients with DM—with the increased risk of sudden death. However, the molecular underpinnings of this fatal disease remain to be elucidated. Methods and Results Here, we used the established streptozotocin-induced DCM murine model to investigate how hypoglycemia aggravates DCM progression. We confirmed connexin 43 (Cx43) dissociation from cell–cell interaction and accumulation at mitochondrial inner membrane both in the cardiomyocytes of patients with DM and DCM murine. Here, we observed that cardiac diastolic function, induced by chronic hyperglycemia, was further aggravated upon hypoglycemia challenge. Similar contractile defects were recapitulated using neonatal mouse ventricular myocytes (NMVMs) under glucose fluctuation challenges. Using immunoprecipitation mass spectrometry, we identified and validated that hypoglycemia challenge activates the mitogen-activated protein kinase kinase (MAPK kinase) (MEK)/extracellular regulated protein kinase (ERK) and inhibits phosphoinositide 3-kinase (PI3K)/Akt pathways, which results in Cx43 phosphorylation by Src protein and translocation to mitochondria in cardiomyocytes. To determine causality, we overexpressed a mitochondrial targeting Cx43 (mtCx43) using adeno-associated virus serotype 2 (AAV2)/9. At normal blood glucose levels, mtCx43 overexpression recapitulated cardiac diastolic dysfunction as well as aberrant electrophysiology in vivo. Our findings give support for therapeutic targeting of MEK/ERK/Src and PI3K/Akt/Src pathways to prevent mtCx43-driven DCM. Conclusion DCM presents compensatory adaptation of mild mtCx43 accumulation, yet acute hypoglycemia challenges result in further accumulation of mtCx43 through the MEK/ERK/Src and PI3K/Akt/Src pathways. We provide evidence that Cx43 mislocalization is present in hearts of patients with DM hearts, STZ-induced DCM murine model, and glucose fluctuation challenged NMVMs. Mechanistically, we demonstrated that mtCx43 is responsible for inducing aberrant contraction and disrupts electrophysiology in cardiomyocytes and our results support targeting of mtCx43 in treating DCM.
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Affiliation(s)
- Xing Wei
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Andrew Chia Hao Chang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haishuang Chang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shan Xu
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yilin Xue
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuanxin Zhang
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ming Lei
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Alex Chia Yu Chang
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- *Correspondence: Alex Chia Yu Chang
| | - Qingyong Zhang
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Qingyong Zhang
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van Opbergen CJ, Pérez-Hernández M, Delmar M. Luminal Oxidative Regulation of the Ryanodine Receptor: More Sides to the Story? Circ Res 2022; 130:725-727. [PMID: 35239403 PMCID: PMC8909915 DOI: 10.1161/circresaha.122.320798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Chantal J.M. van Opbergen
- Leon H Charney Division of Cardiology, Department of Medicine, NYU-Grossman School of Medicine, New York, USA
| | - Marta Pérez-Hernández
- Leon H Charney Division of Cardiology, Department of Medicine, NYU-Grossman School of Medicine, New York, USA
| | - Mario Delmar
- Leon H Charney Division of Cardiology, Department of Medicine, NYU-Grossman School of Medicine, New York, USA
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Mellor GJ, Tadros R, Krahn AD. Cardiomyopathy Genes and Idiopathic VF: A Known Unknown? Circ Genom Precis Med 2022; 15:e003680. [DOI: 10.1161/circgen.122.003680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Greg J. Mellor
- Cardiology Department, Royal Papworth Hospital, Cambridge, United Kingdom (G.J.M.)
| | - Rafik Tadros
- Cardiovascular Genetics Center, Montreal Heart Institute and Faculty of Medicine, Université de Montréal, QC, Canada (R.T.)
| | - Andrew D. Krahn
- Division of Cardiology, Center for Cardiovascular Innovation, University of British Columbia, Vancouver, Canada (A.D.K.)
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Boogerd CJ, Lacraz GPA, Vértesy Á, van Kampen SJ, Perini I, de Ruiter H, Versteeg D, Brodehl A, van der Kraak P, Giacca M, de Jonge N, Junker JP, van Oudenaarden A, Vink A, van Rooij E. OUP accepted manuscript. Cardiovasc Res 2022; 119:477-491. [PMID: 35576477 PMCID: PMC10064846 DOI: 10.1093/cvr/cvac072] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 04/12/2022] [Accepted: 04/20/2022] [Indexed: 11/13/2022] Open
Abstract
AIMS Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiac disorder that is characterized by progressive loss of myocardium that is replaced by fibro-fatty cells, arrhythmias, and sudden cardiac death. While myocardial degeneration and fibro-fatty replacement occur in specific locations, the underlying molecular changes remain poorly characterized. Here, we aim to delineate local changes in gene expression to identify new genes and pathways that are relevant for specific remodelling processes occurring during ACM. METHODS AND RESULTS Using Tomo-Seq, genome-wide transcriptional profiling with high spatial resolution, we created transmural epicardial-to-endocardial gene expression atlases of explanted ACM hearts to gain molecular insights into disease-driving processes. This enabled us to link gene expression profiles to the different regional remodelling responses and allowed us to identify genes that are potentially relevant for disease progression. In doing so, we identified distinct gene expression profiles marking regions of cardiomyocyte degeneration and fibro-fatty remodelling and revealed Zinc finger and BTB domain-containing protein 11 (ZBTB11) to be specifically enriched at sites of active fibro-fatty replacement of myocardium. Immunohistochemistry indicated ZBTB11 to be induced in cardiomyocytes flanking fibro-fatty areas, which could be confirmed in multiple cardiomyopathy patients. Forced overexpression of ZBTB11 induced autophagy and cell death-related gene programmes in human cardiomyocytes, leading to increased apoptosis. CONCLUSION Our study shows the power of Tomo-Seq to unveil new molecular mechanisms in human cardiomyopathy and uncovers ZBTB11 as a novel driver of cardiomyocyte loss.
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Affiliation(s)
| | | | | | - Sebastiaan J van Kampen
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ilaria Perini
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, Utrecht, The Netherlands
| | - Hesther de Ruiter
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, Utrecht, The Netherlands
| | - Danielle Versteeg
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, Utrecht, The Netherlands
| | - Andreas Brodehl
- Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Bad Oeynhausen, Germany
| | - Petra van der Kraak
- Department of Pathology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Mauro Giacca
- School of Cardiovascular Medicine and Sciences, King’s College London British Heart Foundation Centre, London, UK
| | - Nicolaas de Jonge
- Department of Cardiology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Jan Philipp Junker
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Alexander van Oudenaarden
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, Utrecht, The Netherlands
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Pitsch M, Kant S, Mytzka C, Leube RE, Krusche CA. Autophagy and Endoplasmic Reticulum Stress during Onset and Progression of Arrhythmogenic Cardiomyopathy. Cells 2021; 11:96. [PMID: 35011658 PMCID: PMC8750195 DOI: 10.3390/cells11010096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/20/2021] [Accepted: 12/23/2021] [Indexed: 11/16/2022] Open
Abstract
Arrhythmogenic cardiomyopathy (AC) is a heritable, potentially lethal disease without a causal therapy. AC is characterized by focal cardiomyocyte death followed by inflammation and progressive formation of connective tissue. The pathomechanisms leading to structural disease onset and progression, however, are not fully elucidated. Recent studies revealed that dysregulation of autophagy and endoplasmic/sarcoplasmic reticulum (ER/SR) stress plays an important role in cardiac pathophysiology. We therefore examined the temporal and spatial expression patterns of autophagy and ER/SR stress indicators in murine AC models by qRT-PCR, immunohistochemistry, in situ hybridization and electron microscopy. Cardiomyocytes overexpressing the autophagy markers LC3 and SQSTM1/p62 and containing prominent autophagic vacuoles were detected next to regions of inflammation and fibrosis during onset and chronic disease progression. mRNAs of the ER stress markers Chop and sXbp1 were elevated in both ventricles at disease onset. During chronic disease progression Chop mRNA was upregulated in right ventricles. In addition, reduced Ryr2 mRNA expression together with often drastically enlarged ER/SR cisternae further indicated SR dysfunction during this disease phase. Our observations support the hypothesis that locally altered autophagy and enhanced ER/SR stress play a role in AC pathogenesis both at the onset and during chronic progression.
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Affiliation(s)
| | | | | | - Rudolf E. Leube
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany; (M.P.); (S.K.); (C.M.)
| | - Claudia A. Krusche
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany; (M.P.); (S.K.); (C.M.)
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Morningstar JE, Gensemer C, Moore R, Fulmer D, Beck TC, Wang C, Moore K, Guo L, Sieg F, Nagata Y, Bertrand P, Spampinato RA, Glover J, Poelzing S, Gourdie RG, Watts K, Richardson WJ, Levine RA, Borger MA, Norris RA. Mitral Valve Prolapse Induces Regionalized Myocardial Fibrosis. J Am Heart Assoc 2021; 10:e022332. [PMID: 34873924 PMCID: PMC9075228 DOI: 10.1161/jaha.121.022332] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 10/13/2021] [Indexed: 02/06/2023]
Abstract
Background Mitral valve prolapse (MVP) is one of the most common forms of cardiac valve disease and affects 2% to 3% of the population. Previous imaging reports have indicated that myocardial fibrosis is common in MVP and described its association with sudden cardiac death. These data combined with evidence for postrepair ventricular dysfunction in surgical patients with MVP support a link between fibrosis and MVP. Methods and Results We performed histopathologic analysis of left ventricular (LV) biopsies from peripapillary regions, inferobasal LV wall and apex on surgical patients with MVP, as well as in a mouse model of human MVP (Dzip1S14R/+). Tension-dependent molecular pathways were subsequently assessed using both computational modeling and cyclical stretch of primary human cardiac fibroblasts in vitro. Histopathology of LV biopsies revealed regionalized fibrosis in the peripapillary myocardium that correlated with increased macrophages and myofibroblasts. The MVP mouse model exhibited similar regional increases in collagen deposition that progress over time. As observed in the patient biopsies, increased macrophages and myofibroblasts were observed in fibrotic areas within the murine heart. Computational modeling revealed tension-dependent profibrotic cellular and molecular responses consistent with fibrosis locations related to valve-induced stress. These simulations also identified mechanosensing primary cilia as involved in profibrotic pathways, which was validated in vitro and in human biopsies. Finally, in vitro stretching of primary human cardiac fibroblasts showed that stretch directly activates profibrotic pathways and increases extracellular matrix protein production. Conclusions The presence of prominent regional LV fibrosis in patients and mice with MVP supports a relationship between MVP and progressive damaging effects on LV structure before overt alterations in cardiac function. The regionalized molecular and cellular changes suggest a reactive response of the papillary and inferobasal myocardium to increased chordal tension from a prolapsing valve. These studies raise the question whether surgical intervention on patients with MVP should occur earlier than indicated by current guidelines to prevent advanced LV fibrosis and potentially reduce residual risk of LV dysfunction and sudden cardiac death.
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Affiliation(s)
| | | | - Reece Moore
- Medical University of South CarolinaCharlestonSC
| | - Diana Fulmer
- Medical University of South CarolinaCharlestonSC
| | | | | | - Kelsey Moore
- Medical University of South CarolinaCharlestonSC
| | - Lilong Guo
- Medical University of South CarolinaCharlestonSC
| | - Franz Sieg
- Leipzig Heart InstituteUniversity of LeipzigGermany
| | - Yasufumi Nagata
- Cardiac Ultrasound LaboratoryCardiology DivisionMassachusetts General HospitalBostonMA
| | - Philippe Bertrand
- Cardiac Ultrasound LaboratoryCardiology DivisionMassachusetts General HospitalBostonMA
| | | | | | - Stephen Poelzing
- Center for Heart and Reparative Medicine ResearchFralin Biomedical Research InstituteVirginia TechRoanokeVA
| | - Robert G. Gourdie
- Center for Heart and Reparative Medicine ResearchFralin Biomedical Research InstituteVirginia TechRoanokeVA
| | - Kelsey Watts
- Biomedical Data Science and Informatics ProgramDepartment of BioengineeringClemson UniversityClemsonSC
| | - William J. Richardson
- Biomedical Data Science and Informatics ProgramDepartment of BioengineeringClemson UniversityClemsonSC
| | - Robert A. Levine
- Cardiac Ultrasound LaboratoryCardiology DivisionMassachusetts General HospitalBostonMA
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Zhang K, Cloonan PE, Sundaram S, Liu F, Das SL, Ewoldt JK, Bays JL, Tomp S, Toepfer CN, Marsiglia JDC, Gorham J, Reichart D, Eyckmans J, Seidman JG, Seidman CE, Chen CS. Plakophilin-2 truncating variants impair cardiac contractility by disrupting sarcomere stability and organization. SCIENCE ADVANCES 2021; 7:eabh3995. [PMID: 34652945 PMCID: PMC8519574 DOI: 10.1126/sciadv.abh3995] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 08/25/2021] [Indexed: 05/10/2023]
Abstract
Progressive loss of cardiac systolic function in arrhythmogenic cardiomyopathy (ACM) has recently gained attention as an important clinical consideration in managing the disease. However, the mechanisms leading to reduction in cardiac contractility are poorly defined. Here, we use CRISPR gene editing to generate human induced pluripotent stem cells (iPSCs) that harbor plakophilin-2 truncating variants (PKP2tv), the most prevalent ACM-linked mutations. The PKP2tv iPSC–derived cardiomyocytes are shown to have aberrant action potentials and reduced systolic function in cardiac microtissues, recapitulating both the electrical and mechanical pathologies reported in ACM. By combining cell micropatterning with traction force microscopy and live imaging, we found that PKP2tvs impair cardiac tissue contractility by destabilizing cell-cell junctions and in turn disrupting sarcomere stability and organization. These findings highlight the interplay between cell-cell adhesions and sarcomeres required for stabilizing cardiomyocyte structure and function and suggest fundamental pathogenic mechanisms that may be shared among different types of cardiomyopathies.
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Affiliation(s)
- Kehan Zhang
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Paige E. Cloonan
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Subramanian Sundaram
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Feng Liu
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shoshana L. Das
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
- Harvard-MIT Program in Health Sciences and Technology, Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jourdan K. Ewoldt
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Jennifer L. Bays
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Samuel Tomp
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Christopher N. Toepfer
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | | | - Joshua Gorham
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Daniel Reichart
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Jeroen Eyckmans
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | | | - Christine E. Seidman
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Christopher S. Chen
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
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Lyon A, van Opbergen CJM, Delmar M, Heijman J, van Veen TAB. In silico Identification of Disrupted Myocardial Calcium Homeostasis as Proarrhythmic Trigger in Arrhythmogenic Cardiomyopathy. Front Physiol 2021; 12:732573. [PMID: 34630150 PMCID: PMC8497808 DOI: 10.3389/fphys.2021.732573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/27/2021] [Indexed: 11/30/2022] Open
Abstract
Background: Patients with arrhythmogenic cardiomyopathy may suffer from lethal ventricular arrhythmias. Arrhythmogenic cardiomyopathy is predominantly triggered by mutations in plakophilin-2, a key component of cell-to-cell adhesion and calcium cycling regulation in cardiomyocytes. Calcium dysregulation due to plakophilin-2 mutations may lead to arrhythmias but the underlying pro-arrhythmic mechanisms remain unclear. Aim: To unravel the mechanisms by which calcium-handling abnormalities in plakophilin-2 loss-of-function may contribute to proarrhythmic events in arrhythmogenic cardiomyopathy. Methods: We adapted a computer model of mouse ventricular electrophysiology using recent experimental calcium-handling data from plakophilin-2 conditional knock-out (PKP2-cKO) mice. We simulated individual effects of beta-adrenergic stimulation, modifications in connexin43-mediated calcium entry, sodium-calcium exchanger (NCX) activity and ryanodine-receptor 2 (RyR2) calcium affinity on cellular electrophysiology and occurrence of arrhythmogenic events (delayed-afterdepolarizations). A population-of-models approach was used to investigate the generalizability of our findings. Finally, we assessed the potential translation of proposed mechanisms to humans, using a human ventricular cardiomyocyte computational model. Results: The model robustly reproduced the experimental calcium-handling changes in PKP2-cKO cardiomyocytes: an increased calcium transient amplitude (562 vs. 383 nM), increased diastolic calcium (120 vs. 91 nM), reduced L-type calcium current (15.0 vs. 21.4 pA/pF) and an increased free SR calcium (0.69 vs. 0.50 mM). Under beta-adrenergic stimulation, PKP2-cKO models from the population of models (n = 61) showed a higher susceptibility to delayed-afterdepolarizations compared to control (41 vs. 3.3%). Increased connexin43-mediated calcium entry further elevated the number of delayed-afterdepolarizations (78.7%, 2.5-fold increase in background calcium influx). Elevated diastolic cleft calcium appeared responsible for the increased RyR2-mediated calcium leak, promoting delayed-afterdepolarizations occurrence. A reduction in RyR2 calcium affinity prevented delayed-afterdepolarizations in PKP2-cKO models (24.6 vs. 41%). An additional increase in INCX strongly reduced delayed-afterdepolarizations occurrence, by lowering diastolic cleft calcium levels. The human model showed similar outcomes, suggesting a potential translational value of these findings. Conclusion: Beta-adrenergic stimulation and connexin43-mediated calcium entry upon loss of plakophilin-2 function contribute to generation of delayed-afterdepolarizations. RyR2 and NCX dysregulation play a key role in modulating these proarrhythmic events. This work provides insights into potential future antiarrhythmic strategies in arrhythmogenic cardiomyopathy due to plakophilin-2 loss-of-function.
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Affiliation(s)
- Aurore Lyon
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Chantal J M van Opbergen
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, NY, United States
| | - Mario Delmar
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, NY, United States
| | - Jordi Heijman
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands
| | - Toon A B van Veen
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht, Utrecht, Netherlands
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Zhang J, Liang Y, Bradford WH, Sheikh F. Desmosomes: emerging pathways and non-canonical functions in cardiac arrhythmias and disease. Biophys Rev 2021; 13:697-706. [PMID: 34765046 PMCID: PMC8555023 DOI: 10.1007/s12551-021-00829-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/12/2021] [Indexed: 12/14/2022] Open
Abstract
Desmosomes are critical adhesion structures in cardiomyocytes, with mutation/loss linked to the heritable cardiac disease, arrhythmogenic right ventricular cardiomyopathy (ARVC). Early studies revealed the ability of desmosomal protein loss to trigger ARVC disease features including structural remodeling, arrhythmias, and inflammation; however, the precise mechanisms contributing to diverse disease presentations are not fully understood. Recent mechanistic studies demonstrated the protein degradation component CSN6 is a resident cardiac desmosomal protein which selectively restricts cardiomyocyte desmosomal degradation and disease. This suggests defects in protein degradation can trigger the structural remodeling underlying ARVC. Additionally, a subset of ARVC-related mutations show enhanced vulnerability to calpain-mediated degradation, further supporting the relevance of these mechanisms in disease. Desmosomal gene mutations/loss has been shown to impact arrhythmogenic pathways in the absence of structural disease within ARVC patients and model systems. Studies have shown the involvement of connexins, calcium handling machinery, and sodium channels as early drivers of arrhythmias, suggesting these may be distinct pathways regulating electrical function from the desmosome. Emerging evidence has suggested inflammation may be an early mechanism in disease pathogenesis, as clinical reports have shown an overlap between myocarditis and ARVC. Recent studies focus on the association between desmosomal mutations/loss and inflammatory processes including autoantibodies and signaling pathways as a way to understand the involvement of inflammation in ARVC pathogenesis. A specific focus will be to dissect ongoing fields of investigation to highlight diverse pathogenic pathways associated with desmosomal mutations/loss.
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Affiliation(s)
- Jing Zhang
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Yan Liang
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - William H. Bradford
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Farah Sheikh
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
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50
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Ai X, Yan J, Pogwizd SM. Serine-threonine protein phosphatase regulation of Cx43 dephosphorylation in arrhythmogenic disorders. Cell Signal 2021; 86:110070. [PMID: 34217833 PMCID: PMC8963383 DOI: 10.1016/j.cellsig.2021.110070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/11/2021] [Accepted: 06/29/2021] [Indexed: 12/11/2022]
Abstract
Regulation of cell-to-cell communication in the heart by the gap junction protein Connexin43 (Cx43) involves modulation of Cx43 phosphorylation state by protein kinases, and dephosphorylation by protein phosphatases. Dephosphorylation of Cx43 has been associated with impaired intercellular coupling and enhanced arrhythmogenesis in various pathologic states. While there has been extensive study of the protein kinases acting on Cx43, there has been limited studies of the protein phosphatases that may underlie Cx43 dephosphorylation. The focus of this review is to introduce serine-threonine protein phosphatase regulation of Cx43 phosphorylation state and cell-to-cell communication, and its impact on arrhythmogenesis in the setting of chronic heart failure and myocardial ischemia, as well as on atrial fibrillation. We also discuss the therapeutic potential of modulating protein phosphatases to treat arrhythmias in these clinical settings.
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Affiliation(s)
- Xun Ai
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Jiajie Yan
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Steven M Pogwizd
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States of America.
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