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Kloosterman M, Boonstra MJ, Roudijk RW, Bourfiss M, van der Schaaf I, Velthuis BK, Eijsvogels TMH, Kirkels FP, van Dam PM, Loh P. Body surface potential mapping detects early disease onset in plakophilin-2-pathogenic variant carriers. Europace 2023; 25:euad197. [PMID: 37433034 PMCID: PMC10368448 DOI: 10.1093/europace/euad197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 07/04/2023] [Indexed: 07/13/2023] Open
Abstract
AIMS Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a progressive inherited cardiac disease. Early detection of disease and risk stratification remain challenging due to heterogeneous phenotypic expression. The standard configuration of the 12 lead electrocardiogram (ECG) might be insensitive to identify subtle ECG abnormalities. We hypothesized that body surface potential mapping (BSPM) may be more sensitive to detect subtle ECG abnormalities. METHODS AND RESULTS We obtained 67 electrode BSPM in plakophilin-2 (PKP2)-pathogenic variant carriers and control subjects. Subject-specific computed tomography/magnetic resonance imaging based models of the heart/torso and electrode positions were created. Cardiac activation and recovery patterns were visualized with QRS- and STT-isopotential map series on subject-specific geometries to relate QRS-/STT-patterns to cardiac anatomy and electrode positions. To detect early signs of functional/structural heart disease, we also obtained right ventricular (RV) echocardiographic deformation imaging. Body surface potential mapping was obtained in 25 controls and 42 PKP2-pathogenic variant carriers. We identified five distinct abnormal QRS-patterns and four distinct abnormal STT-patterns in the isopotential map series of 31/42 variant carriers. Of these 31 variant carriers, 17 showed no depolarization or repolarization abnormalities in the 12 lead ECG. Of the 19 pre-clinical variant carriers, 12 had normal RV-deformation patterns, while 7/12 showed abnormal QRS- and/or STT-patterns. CONCLUSION Assessing depolarization and repolarization by BSPM may help in the quest for early detection of disease in variant carriers since abnormal QRS- and/or STT-patterns were found in variant carriers with a normal 12 lead ECG. Because electrical abnormalities were observed in subjects with normal RV-deformation patterns, we hypothesize that electrical abnormalities develop prior to functional/structural abnormalities in ARVC.
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Affiliation(s)
- Manon Kloosterman
- Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Machteld J Boonstra
- Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Rob W Roudijk
- Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mimount Bourfiss
- Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Iris van der Schaaf
- Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Birgitta K Velthuis
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Thijs M H Eijsvogels
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Feddo P Kirkels
- Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter M van Dam
- Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
- ECG-Excellence BV, Nieuwerbrug, The Netherlands
| | - Peter Loh
- Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
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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: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Stadiotti I, Di Bona A, Pilato CA, Scalco A, Guarino A, Micheli B, Casella M, Tondo C, Rizzo S, Pilichou K, Thiene G, Frigo AC, Pompilio G, Basso C, Sommariva E, Mongillo M, Zaglia T. Neuropeptide Y promotes adipogenesis of human cardiac mesenchymal stromal cells in arrhythmogenic cardiomyopathy. Int J Cardiol 2021; 342:94-102. [PMID: 34400166 DOI: 10.1016/j.ijcard.2021.08.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/22/2021] [Accepted: 08/06/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Arrhythmogenic Cardiomyopathy (AC) is a familial cardiac disease, mainly caused by mutations in desmosomal genes. AC hearts show fibro-fatty myocardial replacement, which favors stress-related life-threatening arrhythmias, predominantly in the young and athletes. AC lacks effective therapies, as its pathogenesis is poorly understood. Recently, we showed that cardiac Mesenchymal Stromal Cells (cMSCs) contribute to adipose tissue in human AC hearts, although the underlying mechanisms are still unclear. PURPOSE We hypothesize that the sympathetic neurotransmitter, Neuropeptide Y (NPY), participates to cMSC adipogenesis in human AC. METHODS For translation of our findings, we combined in vitro cytochemical, molecular and pharmacologic assays on human cMSCs, from myocardial biopsies of healthy controls and AC patients, with the use of existing drugs to interfere with the predicted AC mechanisms. Sympathetic innervation was inspected in human autoptic heart samples, and NPY plasma levels measured in healthy and AC subjects. RESULTS AC cMSCs expressed higher levels of pro-adipogenic isotypes of NPY-receptors (i.e. Y1-R, Y5-R). Consistently, NPY enhanced adipogenesis in AC cMSCs, which was blocked by FDA-approved Y1-R and Y5-R antagonists. AC-associated PKP2 reduction directly caused NPY-dependent adipogenesis in cMSCs. In support of the involvement of sympathetic neurons (SNs) and NPY in AC myocardial remodeling, patients had elevated NPY plasma levels and, in human AC hearts, SNs accumulated in fatty areas and were close to cMSCs. CONCLUSIONS Independently from the disease origin, AC causes in cMSCs a targetable gain of responsiveness to NPY, which leads to increased adipogenesis, thus playing a role in AC myocardial remodeling.
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Affiliation(s)
- Ilaria Stadiotti
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Parea 4, 20138 Milano, Italy
| | - Anna Di Bona
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy; Veneto Institute of Molecular Medicine, VIMM, via Orus 2, 35129 Padova, Italy
| | - Chiara Assunta Pilato
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Parea 4, 20138 Milano, Italy; Department of Biochemical, Surgical and Dentist Sciences, University of Milano, Milano, Italy
| | - Arianna Scalco
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy; Veneto Institute of Molecular Medicine, VIMM, via Orus 2, 35129 Padova, Italy
| | - Anna Guarino
- Cardiovascular Tissue Bank, Centro Cardiologico Monzino IRCCS, Via Parea 4, 20138 Milano, Italy
| | - Barbara Micheli
- Cardiovascular Tissue Bank, Centro Cardiologico Monzino IRCCS, Via Parea 4, 20138 Milano, Italy
| | - Michela Casella
- Heart Rhythm Center, Department of Clinical Electrophysiology and Cardiac Pacing, Centro Cardiologico Monzino IRCCS, Via Parea 4, 20138 Milano, Italy
| | - Claudio Tondo
- Department of Biochemical, Surgical and Dentist Sciences, University of Milano, Milano, Italy; Heart Rhythm Center, Department of Clinical Electrophysiology and Cardiac Pacing, Centro Cardiologico Monzino IRCCS, Via Parea 4, 20138 Milano, Italy
| | - Stefania Rizzo
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy
| | - Kalliopi Pilichou
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy
| | - Gaetano Thiene
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy
| | - Anna Chiara Frigo
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy
| | - Giulio Pompilio
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Parea 4, 20138 Milano, Italy; Department of Biochemical, Surgical and Dentist Sciences, University of Milano, Milano, Italy
| | - Cristina Basso
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy
| | - Elena Sommariva
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino-IRCCS, Via Parea 4, 20138 Milano, Italy.
| | - Marco Mongillo
- Veneto Institute of Molecular Medicine, VIMM, via Orus 2, 35129 Padova, Italy; Department of Biomedical Science, University of Padova, via Ugo Bassi 58/B, 35131 Padova, Italy; CNR Institute of Neuroscience, Padova, Italy.
| | - Tania Zaglia
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, via Giustiniani 2, 35128 Padova, Italy; Veneto Institute of Molecular Medicine, VIMM, via Orus 2, 35129 Padova, Italy; Department of Biomedical Science, University of Padova, via Ugo Bassi 58/B, 35131 Padova, Italy.
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Svensson A, Platonov PG, Haugaa KH, Zareba W, Jensen HK, Bundgaard H, Gilljam T, Madsen T, Hansen J, Dejgaard LA, Karlsson LO, Gréen A, Polonsky B, Edvardsen T, Svendsen JH, Gunnarsson C. Genetic Variant Score and Arrhythmogenic Right Ventricular Cardiomyopathy Phenotype in Plakophilin-2 Mutation Carriers. Cardiology 2021; 146:763-771. [PMID: 34469894 DOI: 10.1159/000519231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 06/14/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Whether detailed genetic information contributes to risk stratification of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) remains uncertain. Pathogenic genetic variants in some genes seem to carry a higher risk for arrhythmia and earlier disease onset than others, but comparisons between variants in the same gene have not been done. Combined Annotation Dependent Depletion (CADD) score is a bioinformatics tool that measures the pathogenicity of each genetic variant. We hypothesized that a higher CADD score is associated with arrhythmic events and earlier age at ARVC manifestations in individuals carrying pathogenic or likely pathogenic genetic variants in plakophilin-2 (PKP2). METHODS CADD scores were calculated using the data from pooled Scandinavian and North American ARVC cohorts, and their association with cardiac events defined as ventricular tachycardia/ventricular fibrillation (VT/VF) or syncope and age at definite ARVC diagnosis were assessed. RESULTS In total, 33 unique genetic variants were reported in 179 patients (90 males, 71 probands, 96 with definite ARVC diagnosis at a median age of 35 years). Cardiac events were reported in 76 individuals (43%), of whom 53 had sustained VT/VF (35%). The CADD score was neither associated with age at cardiac events (HR 1.002, 95% CI: 0.953-1.054, p = 0.933) nor with age at definite ARVC diagnosis (HR 0.992, 95% CI: 0.947-1.039, p = 0.731). CONCLUSION No correlation was found between CADD scores and clinical manifestations of ARVC, indicating that the score has no additional risk stratification value among carriers of pathogenic or likely pathogenic PKP2 genetic variants.
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Affiliation(s)
- Anneli Svensson
- Department of Cardiology and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Pyotr G Platonov
- Department of Cardiology, Clinical Sciences, Lund University and Arrhythmia Clinic, Skåne University Hospital, Lund, Sweden
| | - Kristina H Haugaa
- Department of Cardiology, Centre for Cardiological Innovation, Oslo University Hospital, Oslo, Norway and University of Oslo, Oslo, Norway
| | - Wojciech Zareba
- University of Rochester Medical Center, Rochester, New York, USA
| | - Henrik Kjærulf Jensen
- Department of Cardiology, Aarhus University Hospital and Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Henning Bundgaard
- Unit for Inherited Cardiac Diseases, The Heart Center, The National University Hospital, Copenhagen, Denmark
| | - Thomas Gilljam
- Department of Cardiology, Institute of Medicine at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Trine Madsen
- Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark
| | - Jim Hansen
- Department of Cardiology, Herlev-Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Lars A Dejgaard
- Department of Cardiology, Centre for Cardiological Innovation, Oslo University Hospital, Oslo, Norway and University of Oslo, Oslo, Norway
| | - Lars O Karlsson
- Department of Cardiology and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Anna Gréen
- Department of Clinical Genetics, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | | | - Thor Edvardsen
- Department of Cardiology, Centre for Cardiological Innovation, Oslo University Hospital, Oslo, Norway and University of Oslo, Oslo, Norway
| | - Jesper Hastrup Svendsen
- Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, and Danish National Research Foundation Centre for Cardiac Arrhythmia (DARC), Copenhagen, Denmark and Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cecilia Gunnarsson
- Department of Clinical Genetics, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.,Centre for Rare Diseases in Southeast Region of Sweden, Linköping University, Linköping, Sweden
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Biernacka EK, Borowiec K, Franaszczyk M, Szperl M, Rampazzo A, Woźniak O, Roszczynko M, Śmigielski W, Lutyńska A, Hoffman P. Pathogenic variants in plakophilin-2 gene (PKP2) are associated with better survival in arrhythmogenic right ventricular cardiomyopathy. J Appl Genet 2021; 62:613-620. [PMID: 34191271 PMCID: PMC8571136 DOI: 10.1007/s13353-021-00647-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/02/2021] [Accepted: 06/07/2021] [Indexed: 11/28/2022]
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is mainly caused by mutations in genes encoding desmosomal proteins. Variants in plakophilin-2 gene (PKP2) are the most common cause of the disease, associated with conventional ARVC phenotype. The study aims to evaluate the prevalence of PKP2 variants and examine genotype-phenotype correlation in Polish ARVC cohort. All 56 ARVC patients fulfilling the current criteria were screened for genetic variants in PKP2 using denaturing high-performance liquid chromatography or next-generation sequencing. The clinical evaluation involved medical history, electrocardiogram, echocardiography, and follow-up. Ten variants (5 frameshift, 2 nonsense, 2 splicing, and 1 missense) in PKP2 were found in 28 (50%) cases. All truncating variants are classified as pathogenic/likely pathogenic, while the missense variant is classified as variant of uncertain significance. Patients carrying a PKP2 mutation were younger at diagnosis (p = 0.003), more often had negative T waves in V1-V3 (p = 0.01), had higher left ventricular ejection fraction (p = 0.04), and were less likely to present symptoms of heart failure (p = 0.01) and left ventricular damage progression (p = 0.04). Combined endpoint of death or heart transplant was more frequent in subgroup without PKP2 mutation (p = 0.03). Pathogenic variants in PKP2 are responsible for 50% of ARVC cases in the Polish population and are associated with a better prognosis. ARVC patients with PKP2 mutation are less likely to present left ventricular involvement and heart failure symptoms. Combined endpoint of death or heart transplant was less frequent in this group.
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Affiliation(s)
- Elżbieta K Biernacka
- Department of Congenital Heart Diseases, National Institute of Cardiology, Alpejska 42, 04-628, Warsaw, Poland
| | - Karolina Borowiec
- Department of Congenital Heart Diseases, National Institute of Cardiology, Alpejska 42, 04-628, Warsaw, Poland.
| | - Maria Franaszczyk
- Molecular Biology Laboratory, Department of Medical Biology, National Institute of Cardiology, Warsaw, Poland
| | - Małgorzata Szperl
- Molecular Biology Laboratory, Department of Medical Biology, National Institute of Cardiology, Warsaw, Poland
| | | | - Olgierd Woźniak
- Department of Congenital Heart Diseases, National Institute of Cardiology, Alpejska 42, 04-628, Warsaw, Poland
| | - Marta Roszczynko
- Molecular Biology Laboratory, Department of Medical Biology, National Institute of Cardiology, Warsaw, Poland
| | | | - Anna Lutyńska
- Department of Medical Biology, National Institute of Cardiology, Warsaw, Poland
| | - Piotr Hoffman
- Department of Congenital Heart Diseases, National Institute of Cardiology, Alpejska 42, 04-628, Warsaw, Poland
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Yokobori K, Miyauchi Y, Williams JG, Negishi M. Phosphorylation of vaccinia-related kinase 1 at threonine 386 transduces glucose stress signal in human liver cells. Biosci Rep 2020; 40:BSR20200498. [PMID: 32266931 DOI: 10.1042/BSR20200498] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 12/12/2022] Open
Abstract
Vaccinia-related kinase 1 (VRK1) is a chromatin-associated Ser-Thr kinase that regulates numerous downstream factors including DNA repair as well as stress factors c-Jun and p53. Both c-Jun and p53 are phosphorylated at Ser63 and Thr18, respectively, in response to low glucose (40 mg/dl of medium) but not high glucose (140 mg/dl of medium) in human hepatoma-derived Huh-7 cells. Here, we have determined the molecular mechanism by which VRK1 phosphorylates these residues in response to glucose in Huh-7 cells. Human VRK1 auto-phosphorylates Ser376 and Thr386 in in vitro kinase assays. In Huh-7 cells, this auto-phosphorylation activity is regulated by glucose signaling; Thr386 is auto-phosphorylated only in low glucose medium, while Ser376 is not phosphorylated in either medium. A correlation of this low glucose response phosphorylation of Thr386 with the phosphorylation of c-Jun and p53 suggests that VRK1 phosphorylated at Thr386 catalyzes this phosphorylation. In fact, VRK1 knockdown by siRNA decreases and over-expression of VRK1 T386D increases phosphorylated c-Jun and p53 in Huh-7 cells. Phosphorylation by VRK1 of c-Jun but not p53 is regulated by cadherin Plakophilin-2 (PKP2). The PKP2 is purified from whole extracts of Huh-7 cells cultured in low glucose medium and is characterized to bind a C-terminal peptide of the VRK1 molecules to regulate its substrate specificity toward c-Jun. siRNA knockdowns show that PKP2 transduces low glucose signaling to VRK1 only to phosphorylate c-Jun, establishing the low glucose-PKP2-VRK1-c-Jun pathway as a glucose stress signaling pathway.
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Costa S, Cerrone M, Saguner AM, Brunckhorst C, Delmar M, Duru F. Arrhythmogenic cardiomyopathy: An in-depth look at molecular mechanisms and clinical correlates. Trends Cardiovasc Med 2020:S1050-1738(20)30103-1. [PMID: 32738304 DOI: 10.1016/j.tcm.2020.07.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 02/02/2023]
Abstract
Arrhythmogenic cardiomyopathy (ACM) is a familial disease, with approximately 60% of patients displaying a pathogenic variant. The majority of genes linked to ACM code for components of the desmosome: plakophilin-2 (PKP2), desmoglein-2 (DSG2) and desmocollin-2 (DSC2), plakoglobin (JUP) and desmoplakin (DSP). Genetic variants involving the desmosomes are known to cause dysfunction of cell-to-cell adhesions and intercellular gap junctions. In turn, this may result in failure to mechanically hold together the cardiomyocytes, fibrofatty myocardial replacement, cardiac conduction delay and ventricular arrhythmias. It is becoming clearer that pathogenic variants in desmosomal genes such as PKP2 are not only responsible for a mechanical dysfunction of the intercalated disc (ID), but are also the cause of various pro-arrhythmic mechanisms. In this review, we discuss in detail the different molecular interactions associated with desmosomal pathogenic variants, and their contribution to various ACM phenotypes.
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Zhang Z, Fang Q, Du T, Chen G, Wang Y, Wang DW. Cardiac-Specific Caveolin-3 Overexpression Prevents Post-Myocardial Infarction Ventricular Arrhythmias by Inhibiting Ryanodine Receptor-2 Hyperphosphorylation. Cardiology 2020; 145:136-147. [PMID: 32007997 DOI: 10.1159/000505316] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/05/2019] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Ventricular arrhythmia is the most important risk factor for sudden cardiac death (SCD) after acute myocardial infarction (MI) worldwide. However, the molecular mechanisms underlying these arrhythmias are complex and not completely understood. OBJECTIVE Here, we evaluated whether caveolin-3 (Cav3), the structural protein of caveolae, plays an important role in the therapeutic strategy for ventricular arrhythmias. METHODS A model of cardiac-specific overexpression of Cav3 was established to evaluate the incidence of ventricular arrhythmias after MI in mice. Ca2+ imaging was employed to detect the propensity of adult murine cardiomyocytes to generate arrhythmias, and immunoprecipitation and immunofluorescence were used to determine the relationship of proteins. Additionally, qRT-PCR and western blotting were used to detect the mRNA and protein expression. RESULTS We found that cardiac-specific overexpression of Cav3 delivered by a recombinant adeno-associated viral vector reduced the incidence of ventricular arrhythmias and SCD after MI in mice. Ca2+ imaging and western blotting revealed that overexpression of Cav3 reduced diastolic spontaneous Ca2+ waves by inhibiting the hyperphosphorylation of ryanodine receptor-2 (RyR2) at Ser2814, rather than at Ser2808, compared to in rAAV-red fluorescent protein control mice. Furthermore, we demonstrated that Cav3-regulated RYR2 hyperphosphorylation relied on plakophilin-2 in hypoxia-stimulated cultured cardiomyocytes by western blotting, immunoprecipitation, and immunofluorescence in vitro. CONCLUSIONS Our results suggested a novel role for Cav3 in the prevention of ventricular arrhythmias, thereby identifying a new target for preventing SCD after MI.
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Affiliation(s)
- Zhihao Zhang
- Division of Cardiology, Departments of Internal Medicine and Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qin Fang
- Division of Cardiology, Departments of Internal Medicine and Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Tingyi Du
- Division of Cardiology, Departments of Internal Medicine and Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guangzhi Chen
- Division of Cardiology, Departments of Internal Medicine and Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China,
| | - Yan Wang
- Division of Cardiology, Departments of Internal Medicine and Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dao Wen Wang
- Division of Cardiology, Departments of Internal Medicine and Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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9
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Hermida A, Fressart V, Hidden-Lucet F, Donal E, Probst V, Deharo JC, Chevalier P, Klug D, Mansencal N, Delacretaz E, Cosnay P, Scanu P, Extramiana F, Keller DI, Rouanet S, Charron P, Gandjbakhch E. High risk of heart failure associated with desmoglein-2 mutations compared to plakophilin-2 mutations in arrhythmogenic right ventricular cardiomyopathy/dysplasia. Eur J Heart Fail 2019; 21:792-800. [PMID: 30790397 DOI: 10.1002/ejhf.1423] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/21/2018] [Accepted: 12/23/2018] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Previous studies suggested that genetic status affects the clinical course of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) patients. The aim of this study was to compare the outcome of desmoglein-2 (DSG2) mutation carriers to those who carry the plakophilin-2 (PKP2) mutation, the most common ARVC/D-associated gene. METHODS AND RESULTS Consecutive ARVC/D patients carrying a pathogenic mutation in PKP2 or DSG2 were selected from a national ARVC/D registry. The cumulative freedom from sustained ventricular arrhythmia and cardiac transplantation/death from heart failure (HF) during follow-up was assessed, compared between PKP2 and DSG2, and predictors for ventricular arrhythmia and HF events determined. Overall, 118 patients from 78 families were included: 27 (23%) carried a DSG2 mutation and 91 (77%) a PKP2 mutation. There were no significant differences between DSG2 and PKP2 mutation carriers concerning gender, proband status, age at diagnosis, T-wave inversion, or right ventricular dysfunction at baseline. DSG2 patients displayed more frequent epsilon wave (37% vs. 17%, P = 0.048) and left ventricular dysfunction at diagnosis (54% vs. 10%, P < 0.001). During a median follow-up of 5.6 years (2.5-16), DSG2 and PKP2 mutation carriers displayed a similar risk of sustained ventricular arrhythmia (log-rank P = 0.20), but DSG2 mutation carriers were at higher risk of transplantation/HF-related death (log-rank P < 0.001). The presence of a DSG2 mutation vs. PKP2 mutation was a predictor of transplantation/HF-related death in univariate Cox analysis (P = 0.0005). CONCLUSIONS In this multicentre cohort, DSG2 mutation carriers were found to be at high risk of end-stage HF compared to PKP2 mutation carriers, supporting careful haemodynamic monitoring of these patients. The benefit of early HF treatment needs to be assessed in DSG2 carriers.
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Affiliation(s)
- Alexis Hermida
- Centre de Référence Pour les Maladies Cardiaques Héréditaires, APHP, Hôpital de la Pitié Salpêtrière, Paris, France.,Sorbonne Universités, UPMC Université Paris 6, Assistance Publique-Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, ICAN, Département de Cardiologie, Paris, France.,Service de Rythmologie, Centre Hospitalo-Universitaire, Amiens, France
| | - Véronique Fressart
- Centre de Référence Pour les Maladies Cardiaques Héréditaires, APHP, Hôpital de la Pitié Salpêtrière, Paris, France.,Sorbonne Universités, UPMC Université Paris 6, Assistance Publique-Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, ICAN, Département de Cardiologie, Paris, France
| | - Francoise Hidden-Lucet
- Centre de Référence Pour les Maladies Cardiaques Héréditaires, APHP, Hôpital de la Pitié Salpêtrière, Paris, France.,Sorbonne Universités, UPMC Université Paris 6, Assistance Publique-Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, ICAN, Département de Cardiologie, Paris, France
| | - Erwan Donal
- Département de Cardiologie, Hôpital Pontchaillou, Rennes, France
| | - Vincent Probst
- Institut du Thorax, Centre Hospitalo-Universitaire, Nantes, France
| | - Jean-Claude Deharo
- Département de Cardiologie, Centre Hospitalo-Universitaire, Marseille, France
| | - Philippe Chevalier
- Département de Cardiologie, Centre Hospitalo-Universitaire, Lyon, France
| | - Didier Klug
- Département de Cardiologie, Centre Hospitalo-Universitaire, Lille, France
| | - Nicolas Mansencal
- AP-HP, Groupe Hospitalier Ambroise Paré, UVSQ, INSERM U1018, CESP, Boulogne, France
| | | | - Pierre Cosnay
- Département de Cardiologie, Centre Hospitalo-Universitaire, Tours, France
| | - Patrice Scanu
- Département de Cardiologie, Centre Hospitalo-Universitaire, Caen, France
| | - Fabrice Extramiana
- Centre de Référence Pour les Maladies Cardiaques Héréditaires, APHP, Hôpital de la Pitié Salpêtrière, Paris, France.,Département de Cardiologie, Centre Hospitalo-Universitaire Bichat-Claude-Bernard, Paris, France
| | - Dagmar I Keller
- Emergency Department, University Hospital Zurich, Zurich, Switzerland
| | | | - Philippe Charron
- Centre de Référence Pour les Maladies Cardiaques Héréditaires, APHP, Hôpital de la Pitié Salpêtrière, Paris, France.,AP-HP, Groupe Hospitalier Ambroise Paré, UVSQ, INSERM U1018, CESP, Boulogne, France
| | - Estelle Gandjbakhch
- Centre de Référence Pour les Maladies Cardiaques Héréditaires, APHP, Hôpital de la Pitié Salpêtrière, Paris, France.,Sorbonne Universités, UPMC Université Paris 6, Assistance Publique-Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, ICAN, Département de Cardiologie, Paris, France
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10
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Soveizi M, Rabbani B, Rezaei Y, Saedi S, Najafi N, Maleki M, Mahdieh N. Autosomal Recessive Nonsyndromic Arrhythmogenic Right Ventricular Cardiomyopathy without Cutaneous Involvements: A Novel Mutation. Ann Hum Genet 2017; 81:135-140. [PMID: 28523642 DOI: 10.1111/ahg.12193] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/20/2017] [Accepted: 03/21/2017] [Indexed: 11/26/2022]
Abstract
The arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a genetic disease frequently associated with desmosomal mutations, mainly attributed to dominant mutations in the Plakophilin-2 (PKP2) gene. Naxos and Carvajal are the syndromic forms of ARVD/C due to recessive mutations. Herein, we report an autosomal recessive form of nonsyndromic ARVD/C caused by a mutation in the PKP2 gene. After examination and implementation of diagnostic modalities, the definite diagnosis of ARVD/C was confirmed by detection of ventricular tachycardia with a left bundle branch configuration and a superior axis, T-wave inversion in right precordial leads (i.e., V1-V3) in a 12-lead electrocardiogram, and a right ventricle outflow tract dilatation. Neither cutaneous involvement nor other abnormalities were observed. Genetic testing was performed during which an intronic mutation of c.2577+1G>T in the PKP2 gene was observed homozygously. The c.2577+1G>T disrupts PKP2 mRNA splicing and causes a nonsyndromic form of ARVD/C.
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Affiliation(s)
- Mahdieh Soveizi
- Cardiogenetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Bahareh Rabbani
- Cardiogenetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Yousef Rezaei
- Cardiogenetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.,Heart Valve Disease Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sedigheh Saedi
- Cardiogenetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Nasim Najafi
- Cardiogenetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Majid Maleki
- Cardiogenetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Nejat Mahdieh
- Cardiogenetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
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11
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Peters S. Electrocardiographic differences in desmosomal and non-desmosomal arrhythmogenic cardiomyopathy. Int J Cardiol 2016; 203:1005-6. [PMID: 26625331 DOI: 10.1016/j.ijcard.2015.11.089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 11/16/2015] [Indexed: 11/19/2022]
Affiliation(s)
- Stefan Peters
- St. Elisabeth Hospital gGmbH Salzgitter, Liebenhaller Str. 20, 38259 Salzgitter, Germany.
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12
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Leo-Macías A, Liang FX, Delmar M. Ultrastructure of the intercellular space in adult murine ventricle revealed by quantitative tomographic electron microscopy. Cardiovasc Res 2015; 107:442-52. [PMID: 26113266 DOI: 10.1093/cvr/cvv182] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 06/17/2015] [Indexed: 11/13/2022] Open
Abstract
AIMS Progress in tissue preservation (high-pressure freezing), data acquisition (tomographic electron microscopy, TEM), and analysis (image segmentation and quantification) have greatly improved the level of information extracted from ultrastructural images. Here, we combined these methods and developed analytical tools to provide an in-depth morphometric description of the intercalated disc (ID) in adult murine ventricle. As a point of comparison, we characterized the ultrastructure of the ID in mice heterozygous-null for the desmosomal gene plakophilin-2 (PKP2; mice dubbed PKP2-Hz). METHODS AND RESULTS Tomographic EM images of thin sections of adult mouse ventricular tissue were processed by image segmentation analysis. Novel morphometric routines allowed us to generate the first quantitative description of the ID intercellular space based on three-dimensional data. We show that complex invaginations of the cell membrane significantly increased the total ID surface area. In addition, PKP2-Hz samples showed increased average intercellular spacing, ID surface area, and membrane tortuosity, as well as reduced number and length of mechanical junctions compared with control. Finally, we observed membranous structures reminiscent of junctional sarcoplasmic reticulum at the ID, which were significantly more abundant in PKP2-Hz hearts. CONCLUSION We have developed a systematic method to characterize the ultrastructure of the intercellular space in the adult murine ventricle and have provided a quantitative description of the structure of the intercellular membranes and of the intercellular space. We further show that PKP2 deficiency associates with ultrastructural defects. The possible importance of the intercellular space in cardiac behaviour is discussed.
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Affiliation(s)
- Alejandra Leo-Macías
- Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Feng-Xia Liang
- Microscopy Core, New York University School of Medicine, New York, NY, USA
| | - Mario Delmar
- Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First Avenue, Smilow 805, New York, NY 10016, USA
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13
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Affiliation(s)
- Brenda Gerull
- From the Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
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14
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Affiliation(s)
- S Peters
- St. Elisabeth Hospital Salzgitter, Germany.
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15
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Peters S. Arrhythmogenic cardiomyopathy and provocable Brugada ECG in a patient caused by missense mutation in plakophilin-2. Int J Cardiol 2014; 173:317-8. [PMID: 24681023 DOI: 10.1016/j.ijcard.2014.03.071] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 03/09/2014] [Indexed: 11/15/2022]
Affiliation(s)
- Stefan Peters
- St. Elisabeth Hospital gGmbH Salzgitter, Liebenhaller Str. 20, 38259 Salzgitter, Germany.
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16
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Agullo-Pascual E, Cerrone M, Delmar M. Arrhythmogenic cardiomyopathy and Brugada syndrome: diseases of the connexome. FEBS Lett 2014; 588:1322-30. [PMID: 24548564 DOI: 10.1016/j.febslet.2014.02.008] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 02/06/2014] [Accepted: 02/06/2014] [Indexed: 11/30/2022]
Abstract
This review summarizes data in support of the notion that the cardiac intercalated disc is the host of a protein interacting network, called "the connexome", where molecules classically defined as belonging to one particular structure (e.g., desmosomes, gap junctions, sodium channel complex) actually interact with others, and together, control excitability, electrical coupling and intercellular adhesion in the heart. The concept of the connexome is then translated into the understanding of the mechanisms leading to two inherited arrhythmia diseases: arrhythmogenic cardiomyopathy, and Brugada syndrome. The cross-over points in these two diseases are addressed to then suggest that, though separate identifiable clinical entities, they represent "bookends" of a spectrum of manifestations that vary depending on the effect that a particular mutation has on the connexome as a whole.
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Affiliation(s)
- Esperanza Agullo-Pascual
- Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First avenue, Smilow 805, New York, NY 10016, United States
| | - Marina Cerrone
- Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First avenue, Smilow 805, New York, NY 10016, United States
| | - Mario Delmar
- Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First avenue, Smilow 805, New York, NY 10016, United States.
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17
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Agullo-Pascual E, Reid DA, Keegan S, Sidhu M, Fenyö D, Rothenberg E, Delmar M. Super-resolution fluorescence microscopy of the cardiac connexome reveals plakophilin-2 inside the connexin43 plaque. Cardiovasc Res 2013; 100:231-40. [PMID: 23929525 DOI: 10.1093/cvr/cvt191] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Cell function requires formation of molecular clusters localized to discrete subdomains. The composition of these interactomes, and their spatial organization, cannot be discerned by conventional microscopy given the resolution constraints imposed by the diffraction limit of light (∼200-300 nm). Our aims were (i) Implement single-molecule imaging and analysis tools to resolve the nano-scale architecture of cardiac myocytes. (ii) Using these tools, to map two molecules classically defined as components 'of the desmosome' and 'of the gap junction', and defined their spatial organization. METHODS AND RESULTS We built a set-up on a conventional inverted microscope using commercially available optics. Laser illumination, reducing, and oxygen scavenging conditions were used to manipulate the blinking behaviour of individual fluorescent reporters. Movies of blinking fluorophores were reconstructed to generate subdiffraction images at ∼20 nm resolution. With this method, we characterized clusters of connexin43 (Cx43) and of 'the desmosomal protein' plakophilin-2 (PKP2). In about half of Cx43 clusters, we observed overlay of Cx43 and PKP2 at the Cx43 plaque edge. SiRNA-mediated loss of Ankyrin-G expression yielded larger Cx43 clusters, of less regular shape, and larger Cx43-PKP2 subdomains. The Cx43-PKP2 subdomain was validated by a proximity ligation assay (PLA) and by Monte-Carlo simulations indicating an attraction between PKP2 and Cx43. CONCLUSIONS (i) Super-resolution fluorescence microscopy, complemented with Monte-Carlo simulations and PLAs, allows the study of the nanoscale organization of an interactome in cardiomyocytes. (ii) PKP2 and Cx43 share a common hub that permits direct physical interaction. Its relevance to excitability, electrical coupling, and arrhythmogenic right ventricular cardiomyopathy, is discussed.
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Affiliation(s)
- Esperanza Agullo-Pascual
- The Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First Avenue, Smilow 805, New York, NY 10016, USA
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18
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te Riele AS, James CA, Bhonsale A, Groeneweg JA, Camm CF, Murray B, Tichnell C, van der Heijden JF, Dooijes D, Judge DP. Malignant arrhythmogenic right ventricular dysplasia/cardiomyopathy with a normal 12-lead electrocardiogram: a rare but underrecognized clinical entity. Heart Rhythm. 2013;10:1484-1491. [PMID: 23816439 DOI: 10.1016/j.hrthm.2013.06.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Indexed: 12/25/2022]
Abstract
BACKGROUND In Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C), a normal electrocardiogram (ECG) is considered reassuring. However, some patients with ARVD/C experiencing ventricular arrhythmias have a normal ECG. OBJECTIVES To estimate how often patients with ARVD/C experiencing ventricular arrhythmias have a normal ECG during sinus rhythm, and to provide a clinical profile of these patients. METHODS We included 145 patients with ARVD/C experiencing a documented sustained ventricular arrhythmia. Conventional 12-lead sinus rhythm ECGs within 6 months of the event were reviewed for diagnostic Task Force Criteria (TFC). ECGs were classified as abnormal (≥1 TFC), nonspecific (abnormal, no TFC), or normal. Cardiologic investigations within 6 months of the event were evaluated as per TFC in those with a nonspecific or normal ECG. RESULTS The ECG was nonspecific or normal in 17 of 145 (12%) subjects. Mean age of these patients was 41.3 ± 12.4 years and 14 (82%) were men, comparable to those with an abnormal ECG. Most patients with a nonspecific or normal ECG showed ≥1 TFC on Holter monitoring (n = 9 of 10) and signal-averaged ECG (n = 4 of 5), and all had nonsustained ventricular tachycardia recorded. Among 15 patients who underwent structural evaluation, 11 (73%) showed structural TFC (9 major and 2 minor). CONCLUSIONS Although most patients with ARVD/C experiencing arrhythmias have an abnormal ECG, a nonspecific or normal ECG does not preclude ARVD/C diagnosis. All patients with a nonspecific or normal ECG had alternative evidence of disease expression. These results alert the physician not to rely exclusively on ECG in ARVD/C, but to assess arrhythmic risk by comprehensive clinical evaluation.
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