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Réant P, Bonnet G, Dubé F, Massie C, Reynaud A, Michaud M, Duchateau J, Lafitte S. Hypersynchrony in sarcomeric hypertrophic cardiomyopathy: description and mechanistic approach using multimodal electro-mechanical non-invasive cartography (HSYNC study). Front Cardiovasc Med 2024; 11:1359657. [PMID: 38911519 PMCID: PMC11193380 DOI: 10.3389/fcvm.2024.1359657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 05/27/2024] [Indexed: 06/25/2024] Open
Abstract
Background Little is known about left ventricular (LV) sequences of contraction and electrical activation in hypertrophic cardiomyopathy (HCM). A better understanding of the underlying relation between mechanical and electrical activation may allow the identification of predictive response criteria to right ventricular DDD pacing in obstructive patients. Objective To describe LV mechanical and electrical activation sequences in HCM patients compared to controls. Materials and methods We prospectively studied, in 40 HCM patients (20 obstructive and 20 non-obstructive) and 20 healthy controls: (1) mechanical activation using echocardiography at rest and cardiac magnetic resonance imaging, (2) electrical activation using 3-dimensional electrocardiographic mapping (ECM). Results In echocardiography, healthy controls had a physiological apex-to-base delay (ABD) during contraction (23.8 ± 16.2 ms). Among the 40 HCM patients, 18 HCM patients presented a loss of this ABD (<10 ms, defining hypersynchrony) more frequently than controls (45% vs. 5%, p = 0.017). These patients had a lower LV end-diastolic volume (71.4 ± 9.7 ml/m2 vs. 82.4 ± 14.8 ml/m2, p = 0.01), lower native T1 values (988 ± 32 ms vs. 1,028 ± 39 ms, p = 0.001) and tended to have lower LV mass (80.7 ± 23.7 g/m2 vs. 94.5 ± 25.3 g/m2, p = 0.08) compared with HCM patients that had a physiological contraction sequence. There was no significant relation between ABD and LV outflow tract obstruction. While HCM patients with a physiological contraction sequence presented an ECM close to those encountered in controls, patients with a loss of ABD presented a particular pattern of ECM with the first potential more frequently occurring in the postero-basal region. Conclusion The LV contraction sequence can be modified in HCM patients, with a loss of the physiological ABD, and is associated with smaller LV dimensions and a particular pattern of ECM. Further research is needed to determine whether this pattern is related to an electrical substrate or is the consequence of the hypertrophied heart's specific geometry. Clinical trial registration ClinicalTrial.gov: NCT02559726.
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Affiliation(s)
- Patricia Réant
- Cardiology Department, Bordeaux University Hospital, Bordeaux, France
- Cardiology Department, University of Bordeaux, Bordeaux, France
- Cardiology Department, IHU Lyric, Bordeaux-Pessac, France
- Cardiology Department, CIC-P 1401, Bordeaux-Pessac, France
- Cardiology Department, INSERM 1045, Bordeaux, France
| | - Guillaume Bonnet
- Cardiology Department, Bordeaux University Hospital, Bordeaux, France
- Cardiology Department, University of Bordeaux, Bordeaux, France
- Cardiology Department, IHU Lyric, Bordeaux-Pessac, France
- Cardiology Department, CIC-P 1401, Bordeaux-Pessac, France
- Cardiology Department, INSERM 1045, Bordeaux, France
| | - Frédérique Dubé
- Cardiology Department, Bordeaux University Hospital, Bordeaux, France
- Cardiology Department, University of Bordeaux, Bordeaux, France
- Cardiology Department, Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Charles Massie
- Cardiology Department, Bordeaux University Hospital, Bordeaux, France
- Cardiology Department, University of Bordeaux, Bordeaux, France
- Cardiology Department, Sacred Heart Hospital of Montreal, Montreal, QC, Canada
| | - Amélie Reynaud
- Cardiology Department, Bordeaux University Hospital, Bordeaux, France
| | - Matthieu Michaud
- Cardiology Department, Bordeaux University Hospital, Bordeaux, France
- Cardiology Department, University of Bordeaux, Bordeaux, France
- Cardiology Department, CIC-P 1401, Bordeaux-Pessac, France
| | - Josselin Duchateau
- Cardiology Department, Bordeaux University Hospital, Bordeaux, France
- Cardiology Department, University of Bordeaux, Bordeaux, France
- Cardiology Department, IHU Lyric, Bordeaux-Pessac, France
| | - Stéphane Lafitte
- Cardiology Department, Bordeaux University Hospital, Bordeaux, France
- Cardiology Department, University of Bordeaux, Bordeaux, France
- Cardiology Department, IHU Lyric, Bordeaux-Pessac, France
- Cardiology Department, CIC-P 1401, Bordeaux-Pessac, France
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2
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Federspiel JM, Reil JC, Xu A, Scholtz S, Batzner A, Maack C, Sequeira V. Retrofitting the Heart: Explaining the Enigmatic Septal Thickening in Hypertrophic Cardiomyopathy. Circ Heart Fail 2024; 17:e011435. [PMID: 38695186 DOI: 10.1161/circheartfailure.123.011435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/26/2024] [Indexed: 05/23/2024]
Abstract
Hypertrophic cardiomyopathy is the most common genetic cardiac disease and is characterized by left ventricular hypertrophy. Although this hypertrophy often associates with sarcomeric gene mutations, nongenetic factors also contribute to the disease, leading to diastolic dysfunction. Notably, this dysfunction manifests before hypertrophy and is linked to hypercontractility, as well as nonuniform contraction and relaxation (myofibril asynchrony) of the myocardium. Although the distribution of hypertrophy in hypertrophic cardiomyopathy can vary both between and within individuals, in most cases, it is primarily confined to the interventricular septum. The reasons for septal thickening remain largely unknown. In this article, we propose that alterations in muscle fiber geometry, present from birth, dictate the septal shape. When combined with hypercontractility and exacerbated by left ventricular outflow tract obstruction, these factors predispose the septum to an isometric type of contraction during systole, consequently constraining its mobility. This contraction, or more accurately, this focal increase in biomechanical stress, prompts the septum to adapt and undergo remodeling. Drawing a parallel, this is reminiscent of how earthquake-resistant buildings are retrofitted with vibration dampers to absorb the majority of the shock motion and load. Similarly, the heart adapts by synthesizing viscoelastic elements such as microtubules, titin, desmin, collagen, and intercalated disc components. This pronounced remodeling in the cytoskeletal structure leads to noticeable septal hypertrophy. This structural adaptation acts as a protective measure against damage by attenuating myofibril shortening while reducing cavity tension according to Laplace Law. By examining these events, we provide a coherent explanation for the septum's predisposition toward hypertrophy.
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Affiliation(s)
- Jan M Federspiel
- Comprehensive Heart Failure Center, Department of Translational Science University Clinic Würzburg, Germany (J.M.F., A.X., A.B., C.M., V.S.)
- Saarland University, Faculty of Medicine, Institute for Legal Medicine, Homburg (Saar), Germany (J.M.F.)
| | - Jan-Christian Reil
- Klinik für allgemeine und interventionelle Kardiologie, Herz- und Diabetes-Zentrum Nordrhein-Westphalen, Germany (J.-C.R., S.S.)
| | - Anton Xu
- Comprehensive Heart Failure Center, Department of Translational Science University Clinic Würzburg, Germany (J.M.F., A.X., A.B., C.M., V.S.)
| | - Smita Scholtz
- Klinik für allgemeine und interventionelle Kardiologie, Herz- und Diabetes-Zentrum Nordrhein-Westphalen, Germany (J.-C.R., S.S.)
| | - Angelika Batzner
- Comprehensive Heart Failure Center, Department of Translational Science University Clinic Würzburg, Germany (J.M.F., A.X., A.B., C.M., V.S.)
- Department of Internal Medicine I, University Hospital Würzburg, Germany (A.B.)
| | - Christoph Maack
- Comprehensive Heart Failure Center, Department of Translational Science University Clinic Würzburg, Germany (J.M.F., A.X., A.B., C.M., V.S.)
| | - Vasco Sequeira
- Comprehensive Heart Failure Center, Department of Translational Science University Clinic Würzburg, Germany (J.M.F., A.X., A.B., C.M., V.S.)
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3
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Okolo CA, Maran JJ, Watts A, Maripillan J, Harkiolaki M, Martínez AD, Green CR, Mugisho OO. Correlative light and X-ray tomography jointly unveil the critical role of connexin43 channels on inflammation-induced cellular ultrastructural alterations. Heliyon 2024; 10:e27888. [PMID: 38560181 PMCID: PMC10979075 DOI: 10.1016/j.heliyon.2024.e27888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 04/04/2024] Open
Abstract
Non-junctional connexin43 (Cx43) plasma membrane hemichannels have been implicated in several inflammatory diseases, particularly playing a role in ATP release that triggers activation of the inflammasome. Therapies targeting the blocking of the hemichannels to prevent the pathological release or uptake of ions and signalling molecules through its pores are of therapeutic interest. To date, there is no close-to-native, high-definition documentation of the impact of Cx43 hemichannel-mediated inflammation on cellular ultrastructure, neither is there a robust account of the ultrastructural changes that occur following treatment with selective Cx43 hemichannel blockers such as Xentry-Gap19 (XG19). A combination of same-sample correlative high-resolution three-dimensional fluorescence microscopy and soft X-ray tomography at cryogenic temperatures, enabled in the identification of novel 3D molecular interactions within the cellular milieu when comparing behaviour in healthy states and during the early onset or late stages under inflammatory conditions. Notably, our findings suggest that XG19 blockage of connexin hemichannels under pro-inflammatory conditions may be crucial in preventing the direct degradation of connexosomes by lysosomes, without affecting connexin protein translation and trafficking. We also delineated fine and gross cellular phenotypes, characteristic of inflammatory insult or road-to-recovery from inflammation, where XG19 could indirectly prevent and reverse inflammatory cytokine-induced mitochondrial swelling and cellular hypertrophy through its action on Cx43 hemichannels. Our findings suggest that XG19 might have prophylactic and therapeutic effects on the inflammatory response, in line with functional studies.
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Affiliation(s)
- Chidinma Adanna Okolo
- Beamline B24, Life Sciences Division, Diamond Light Source, Didcot, Oxfordshire, United Kingdom
| | - Jack Jonathan Maran
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Amy Watts
- Beamline B24, Life Sciences Division, Diamond Light Source, Didcot, Oxfordshire, United Kingdom
| | - Jaime Maripillan
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Universidad de Valparaíso, Valparaíso, Chile
| | - Maria Harkiolaki
- Beamline B24, Life Sciences Division, Diamond Light Source, Didcot, Oxfordshire, United Kingdom
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Universidad de Valparaíso, Valparaíso, Chile
| | - Colin R. Green
- Department of Ophthalmology, University of Auckland, New Zealand
| | - Odunayo Omolola Mugisho
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, New Zealand
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4
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Cianci V, Forzese E, Sapienza D, Cardia L, Cianci A, Germanà A, Tornese L, Ieni A, Gualniera P, Asmundo A, Mondello C. Morphological and Genetic Aspects for Post-Mortem Diagnosis of Hypertrophic Cardiomyopathy: A Systematic Review. Int J Mol Sci 2024; 25:1275. [PMID: 38279275 PMCID: PMC10816624 DOI: 10.3390/ijms25021275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiovascular diseases, and it shows an autosomal dominant pattern of inheritance. HCM can be clinically silent, and sudden unexpected death due to malignant arrhythmias may be the first manifestation. Thus, the HCM diagnosis could be performed at a clinical and judicial autopsy and offer useful findings on morphological features; moreover, it could integrate the knowledge on the genetic aspect of the disease. This review aims to systematically analyze the literature on the main post-mortem investigations and the related findings of HCM to reach a well-characterized and stringent diagnosis; the review was performed using PubMed and Scopus databases. The articles on the post-mortem evaluation of HCM by gross and microscopic evaluation, imaging, and genetic test were selected; a total of 36 studies were included. HCM was described with a wide range of gross findings, and there were cases without morphological alterations. Myocyte hypertrophy, disarray, fibrosis, and small vessel disease were the main histological findings. The post-mortem genetic tests allowed the diagnosis to be reached in cases without morpho-structural abnormalities; clinical and forensic pathologists have a pivotal role in HCM diagnosis; they contribute to a better definition of the disease and also provide data on the genotype-phenotype correlation, which is useful for clinical research.
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Affiliation(s)
- Vincenzo Cianci
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Elena Forzese
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Daniela Sapienza
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Luigi Cardia
- Department of Human Pathology of Adult and Childhood “Gaetano Barresi”, University of Messina, Via C. Valeria 1, 98125 Messina, Italy; (L.C.); (A.I.)
| | - Alessio Cianci
- Department of Cardiovascular Medicine, Fondazione Policlinico Universitario A. Gemelli-IRCCS, Largo A. Gemelli 8, 00168 Rome, Italy;
| | - Antonino Germanà
- Zebrafish Neuromorphology Laboratory, Department of Veterinary Sciences, University of Messina, Via Palatucci snc, 98168 Messina, Italy;
| | - Lorenzo Tornese
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Antonio Ieni
- Department of Human Pathology of Adult and Childhood “Gaetano Barresi”, University of Messina, Via C. Valeria 1, 98125 Messina, Italy; (L.C.); (A.I.)
| | - Patrizia Gualniera
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Alessio Asmundo
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
| | - Cristina Mondello
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Via Consolare Valeria 1, 98125 Messina, Italy; (V.C.); (E.F.); (D.S.); (L.T.); (P.G.)
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5
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Santoro F, Mango F, Mallardi A, D'Alessandro D, Casavecchia G, Gravina M, Correale M, Brunetti ND. Arrhythmic Risk Stratification among Patients with Hypertrophic Cardiomyopathy. J Clin Med 2023; 12:jcm12103397. [PMID: 37240503 DOI: 10.3390/jcm12103397] [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: 02/16/2023] [Revised: 05/07/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a cardiac muscle disorder characterized by generally asymmetric abnormal hypertrophy of the left ventricle without abnormal loading conditions (such as hypertension or valvular heart disease) accounting for the left ventricular wall thickness or mass. The incidence of sudden cardiac death (SCD) in HCM patients is about 1% yearly in adults, but it is far higher in adolescence. HCM is the most frequent cause of death in athletes in the Unites States of America. HCM is an autosomal-dominant genetic cardiomyopathy, and mutations in the genes encoding sarcomeric proteins are identified in 30-60% of cases. The presence of this genetic mutation carries more than 2-fold increased risk for all outcomes, including ventricular arrhythmias. Genetic and myocardial substrate, including fibrosis and intraventricular dispersion of conduction, ventricular hypertrophy and microvascular ischemia, increased myofilament calcium sensitivity and abnormal calcium handling, all play a role as arrhythmogenic determinants. Cardiac imaging studies provide important information for risk stratification. Transthoracic echocardiography can be helpful to evaluate left ventricular (LV) wall thickness, LV outflow-tract gradient and left atrial size. Additionally, cardiac magnetic resonance can evaluate the prevalence of late gadolinium enhancement, which when higher than 15% of LV mass is a prognostic maker of SCD. Age, family history of SCD, syncope and non-sustained ventricular tachycardia at Holter ECG have also been validated as independent prognostic markers of SCD. Arrhythmic risk stratification in HCM requires careful evaluation of several clinical aspects. Symptoms combined with electrocardiogram, cardiac imaging tools and genetic counselling are the modern cornerstone for proper risk stratification.
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Affiliation(s)
- Francesco Santoro
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Federica Mango
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Adriana Mallardi
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Damiano D'Alessandro
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Grazia Casavecchia
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Matteo Gravina
- Radiology Unit, University Polyclinic Hospital of Foggia, 71100 Foggia, Italy
| | - Michele Correale
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Natale Daniele Brunetti
- Cardiology Unit, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
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6
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Moody WE, Elliott PM. Changing concepts in heart muscle disease: the evolving understanding of hypertrophic cardiomyopathy. BRITISH HEART JOURNAL 2022; 108:768-773. [PMID: 35459726 DOI: 10.1136/heartjnl-2021-320145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 02/16/2022] [Indexed: 11/04/2022]
Abstract
Sixty years ago, hypertrophic cardiomyopathy (HCM) was considered a rare lethal disease that affected predominantly young adults and for which there were few treatment options. Today, it is recognised to be a relatively common disorder that presents throughout the life course with a heterogeneous clinical phenotype that can be managed effectively in the majority of individuals. A greater awareness of the condition and less reluctance from healthcare practitioners to make the diagnosis, coupled with improvements in cardiac imaging, including greater use of artificial intelligence and improved yields from screening efforts, have all helped facilitate a more precise and timely diagnosis. This enhanced ability to diagnose HCM early is being paired with innovations in treatment, which means that the majority of patients receiving a contemporary diagnosis of HCM can anticipate a normal life expectancy and expect to maintain a good functional status and quality of life. Indeed, with increasing translation of molecular genetics from bench to bedside associated with a growing number of randomised clinical trials of novel therapies aimed at ameliorating or perhaps even preventing the disease, the next chapter in the story for HCM will provide much excitement and more importantly, offer much anticipated reward for our patients.
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Affiliation(s)
- William E Moody
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK.,Department of Cardiology, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Perry M Elliott
- Institute of Cardiovascular Science, University College London, London, UK
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7
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Decrease of Pdzrn3 is required for heart maturation and protects against heart failure. Sci Rep 2022; 12:8. [PMID: 34996942 PMCID: PMC8742099 DOI: 10.1038/s41598-021-03795-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 11/24/2021] [Indexed: 01/27/2023] Open
Abstract
Heart failure is the final common stage of most cardiopathies. Cardiomyocytes (CM) connect with others via their extremities by intercalated disk protein complexes. This planar and directional organization of myocytes is crucial for mechanical coupling and anisotropic conduction of the electric signal in the heart. One of the hallmarks of heart failure is alterations in the contact sites between CM. Yet no factor on its own is known to coordinate CM polarized organization. We have previously shown that PDZRN3, an ubiquitine ligase E3 expressed in various tissues including the heart, mediates a branch of the Planar cell polarity (PCP) signaling involved in tissue patterning, instructing cell polarity and cell polar organization within a tissue. PDZRN3 is expressed in the embryonic mouse heart then its expression dropped significantly postnatally corresponding with heart maturation and CM polarized elongation. A moderate CM overexpression of Pdzrn3 (Pdzrn3 OE) during the first week of life, induced a severe eccentric hypertrophic phenotype with heart failure. In models of pressure-overload stress heart failure, CM-specific Pdzrn3 knockout showed complete protection against degradation of heart function. We reported that Pdzrn3 signaling induced PKC ζ expression, c-Jun nuclear translocation and a reduced nuclear ß catenin level, consistent markers of the planar non-canonical Wnt signaling in CM. We then show that subcellular localization (intercalated disk) of junction proteins as Cx43, ZO1 and Desmoglein 2 was altered in Pdzrn3 OE mice, which provides a molecular explanation for impaired CM polarization in these mice. Our results reveal a novel signaling pathway that controls a genetic program essential for heart maturation and maintenance of overall geometry, as well as the contractile function of CM, and implicates PDZRN3 as a potential therapeutic target for the prevention of human heart failure.
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Hocini M, Ramirez FD, Szumowski Ł, Maury P, Cheniti G, Duchateau J, Pambrun T, Derval N, Sacher F, Cochet H, Jaïs P, Haïssaguerre M. Purkinje triggers of ventricular fibrillation in patients with hypertrophic cardiomyopathy. J Cardiovasc Electrophysiol 2021; 32:2987-2994. [PMID: 34453363 DOI: 10.1111/jce.15231] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/04/2021] [Accepted: 07/25/2021] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Ventricular fibrillation (VF) is the main mechanism of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). The origin of VF and the success of catheter ablation to eliminate recurrent episodes in this population are poorly understood. METHODS AND RESULTS From 2010 to 2014, five patients with HCM (age 21 ± 9 years, three female) underwent invasive electrophysiological studies and ablation at our center after resuscitation from recurrent (9 ± 7) episodes of VF. Ventricular premature beats (VPBs), seen to initiate VF in certain cases, were recorded noninvasively before the ablation procedure. Postprocedural computed tomography (CT) was performed to correlate ablation sites with myocardial hypertrophy in three patients. Outcomes were assessed by clinical follow-up and implantable cardioverter-defibrillator interrogations. VPB triggers were localized invasively to the distal left Purkinje conduction system (left posterior fascicle [2], left anterior fascicle [1], and both fascicles [2]). All targeted VF triggers were successfully eliminated by radiofrequency ablation in the left ventricle. Among patients with postablation CT imaging, 93 ± 12% of ablation sites corresponded to hypertrophied segments. Over 50 ± 38 months, four of five patients were free from primary VF without antiarrhythmic drug therapy. One patient who had 13 episodes of VF before ablation had a single recurrence. CONCLUSION In our study of patients with HCM and recurrent VF, VF was not initiated from the myocardium but rather from Purkinje arborization. These sources colocalized with the hypertrophic substrate, suggesting electromechanical interaction. Focal ablation at these sites was associated with a marked reduction in VF burden.
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Affiliation(s)
- Mélèze Hocini
- Hôpital Cardiologique du Haut Lévêque, Centre Hospitalier Universitaire de Bordeaux, Bordeaux-Pessac, France.,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Bordeaux-Pessac, France
| | - F Daniel Ramirez
- Hôpital Cardiologique du Haut Lévêque, Centre Hospitalier Universitaire de Bordeaux, Bordeaux-Pessac, France.,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Bordeaux-Pessac, France.,Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Łukasz Szumowski
- Department of Cardiac Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Philippe Maury
- Department of Cardiology, University Hospital Rangueil, Toulouse, France.,Unité INSERM U 1048, Toulouse, France
| | - Ghassen Cheniti
- Hôpital Cardiologique du Haut Lévêque, Centre Hospitalier Universitaire de Bordeaux, Bordeaux-Pessac, France.,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Bordeaux-Pessac, France
| | - Josselin Duchateau
- Hôpital Cardiologique du Haut Lévêque, Centre Hospitalier Universitaire de Bordeaux, Bordeaux-Pessac, France.,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Bordeaux-Pessac, France
| | - Thomas Pambrun
- Hôpital Cardiologique du Haut Lévêque, Centre Hospitalier Universitaire de Bordeaux, Bordeaux-Pessac, France.,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Bordeaux-Pessac, France
| | - Nicolas Derval
- Hôpital Cardiologique du Haut Lévêque, Centre Hospitalier Universitaire de Bordeaux, Bordeaux-Pessac, France.,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Bordeaux-Pessac, France
| | - Frédéric Sacher
- Hôpital Cardiologique du Haut Lévêque, Centre Hospitalier Universitaire de Bordeaux, Bordeaux-Pessac, France.,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Bordeaux-Pessac, France
| | - Hubert Cochet
- Hôpital Cardiologique du Haut Lévêque, Centre Hospitalier Universitaire de Bordeaux, Bordeaux-Pessac, France.,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Bordeaux-Pessac, France
| | - Pierre Jaïs
- Hôpital Cardiologique du Haut Lévêque, Centre Hospitalier Universitaire de Bordeaux, Bordeaux-Pessac, France.,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Bordeaux-Pessac, France
| | - Michel Haïssaguerre
- Hôpital Cardiologique du Haut Lévêque, Centre Hospitalier Universitaire de Bordeaux, Bordeaux-Pessac, France.,L'Institut de Rythmologie et Modélisation Cardiaque (LIRYC), Bordeaux-Pessac, France
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9
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Finocchiaro G, Sheikh N, Leone O, Westaby J, Mazzarotto F, Pantazis A, Ferrantini C, Sacconi L, Papadakis M, Sharma S, Sheppard MN, Olivotto I. Arrhythmogenic potential of myocardial disarray in hypertrophic cardiomyopathy: genetic basis, functional consequences and relation to sudden cardiac death. Europace 2021; 23:985-995. [PMID: 33447843 DOI: 10.1093/europace/euaa348] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 10/28/2020] [Indexed: 12/19/2022] Open
Abstract
Myocardial disarray is defined as disorganized cardiomyocyte spatial distribution, with loss of physiological fibre alignment and orientation. Since the first pathological descriptions of hypertrophic cardiomyopathy (HCM), disarray appeared as a typical feature of this condition and sparked vivid debate regarding its specificity to the disease and clinical significance as a diagnostic marker and a risk factor for sudden death. Although much of the controversy surrounding its diagnostic value in HCM persists, it is increasingly recognized that myocardial disarray may be found in physiological contexts and in cardiac conditions different from HCM, raising the possibility that central focus should be placed on its quantity and distribution, rather than a mere presence. While further studies are needed to establish what amount of disarray should be considered as a hallmark of the disease, novel experimental approaches and emerging imaging techniques for the first time allow ex vivo and in vivo characterization of the myocardium to a molecular level. Such advances hold the promise of filling major gaps in our understanding of the functional consequences of myocardial disarray in HCM and specifically on arrhythmogenic propensity and as a risk factor for sudden death. Ultimately, these studies will clarify whether disarray represents a major determinant of the HCM clinical profile, and a potential therapeutic target, as opposed to an intriguing but largely innocent bystander.
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Affiliation(s)
- Gherardo Finocchiaro
- Cardiothoracic Centre, Guy's and St Thomas' Hospital, London, UK.,King's College London
| | - Nabeel Sheikh
- Cardiothoracic Centre, Guy's and St Thomas' Hospital, London, UK.,King's College London
| | - Ornella Leone
- Cardiovascular and Cardiac Transplant Pathology Unit, Department of Pathology, Sant'Orsola-Malpighi University Hospital, Bologna, Italy
| | - Joe Westaby
- Cardiovascular Pathology Unit and Cardiology Clinical and Academic Group. St George's, University of London, London and St George's University Hospital NHS Foundation Trust, UK
| | - Francesco Mazzarotto
- Cardiomyopathy Unit, Careggi University Hospital, Florence, Italy.,Department of Experimental and Clinical Medicine, University of Florence, Italy.,National Heart and Lung Institute, Imperial College London, UK.,Cardiovascular Research Centre, Royal Brompton and Harefield National Health Service Foundation Trust, London, UK
| | - Antonis Pantazis
- Cardiovascular Research Centre, Royal Brompton and Harefield National Health Service Foundation Trust, London, UK
| | - Cecilia Ferrantini
- University of Florence, Florence, Italy.,European Laboratory for Non-Linear Spectroscopy, Florence, Italy
| | - Leonardo Sacconi
- European Laboratory for Non-Linear Spectroscopy, Florence, Italy.,Institute for Experimental Cardiovascular Medicine, University of Freiburg, Freiburg, Germany
| | - Michael Papadakis
- Cardiovascular Pathology Unit and Cardiology Clinical and Academic Group. St George's, University of London, London and St George's University Hospital NHS Foundation Trust, UK
| | - Sanjay Sharma
- Cardiovascular Pathology Unit and Cardiology Clinical and Academic Group. St George's, University of London, London and St George's University Hospital NHS Foundation Trust, UK
| | - Mary N Sheppard
- Cardiovascular Pathology Unit and Cardiology Clinical and Academic Group. St George's, University of London, London and St George's University Hospital NHS Foundation Trust, UK
| | - Iacopo Olivotto
- Cardiomyopathy Unit, Careggi University Hospital, Florence, Italy
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10
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Macquart C, Jüttner R, Morales Rodriguez B, Le Dour C, Lefebvre F, Chatzifrangkeskou M, Schmitt A, Gotthardt M, Bonne G, Muchir A. Microtubule cytoskeleton regulates Connexin 43 localization and cardiac conduction in cardiomyopathy caused by mutation in A-type lamins gene. Hum Mol Genet 2020; 28:4043-4052. [PMID: 29893868 DOI: 10.1093/hmg/ddy227] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/05/2018] [Accepted: 06/06/2018] [Indexed: 01/08/2023] Open
Abstract
Mutations in the lamin A/C gene (LMNA) cause an autosomal dominant inherited form of dilated cardiomyopathy associated with cardiac conduction disease (hereafter referred to as LMNA cardiomyopathy). Compared with other forms of dilated cardiomyopathy, mutations in LMNA are responsible for a more aggressive clinical course owing to a high rate of malignant ventricular arrhythmias. Gap junctions are intercellular channels that allow direct communication between neighboring cells, which are involved in electrical impulse propagation and coordinated contraction of the heart. For gap junctions to properly control electrical synchronization in the heart, connexin-based hemichannels must be correctly targeted to intercalated discs, Cx43 being the major connexin in the working myocytes. We here showed an altered distribution of Cx43 in a mouse model of LMNA cardiomyopathy. However, little is known on the molecular mechanisms of Cx43 remodeling in pathological context. We now show that microtubule cytoskeleton alteration and decreased acetylation of α-tubulin lead to remodeling of Cx43 in LMNA cardiomyopathy, which alters the correct communication between cardiomyocytes, ultimately leading to electrical conduction disturbances. Preventing or reversing this process could offer a strategy to repair damaged heart. Stabilization of microtubule cytoskeleton using Paclitaxel improved intraventricular conduction defects. These results indicate that microtubule cytoskeleton contributes to the pathogenesis of LMNA cardiomyopathy and that drugs stabilizing the microtubule may be beneficial for patients.
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Affiliation(s)
- Coline Macquart
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris 75013, France
| | - Rene Jüttner
- Max-Delbrück-Center for Molecular Medicine, DE-13092 Berlin, Germany
| | - Blanca Morales Rodriguez
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris 75013, France
| | - Caroline Le Dour
- Department of Medicine.,Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Florence Lefebvre
- Signaling and Cardiovascular Pathophysiology, UMRS 1180, Université Paris-Sud, INSERM, Chatenay-Malabry 92216, France
| | - Maria Chatzifrangkeskou
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris 75013, France
| | - Alain Schmitt
- Institut Cochin, INSERM U1016-CNRS UMR 8104, Université Paris Descartes-Sorbonne Paris Cité, Paris F-75014, France
| | - Michael Gotthardt
- DZHK (German Centre for Cardiovascular Research), Berlin, Germany.,Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine, 13092 Berlin, Germany
| | - Gisèle Bonne
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris 75013, France
| | - Antoine Muchir
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Paris 75013, France
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11
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Sukhacheva TV, Serov RA, Bockeria LA. [Hypertrophic cardiomyopathy. Cardiomyocyte ultrastructure, the specific or stereotypic signs]. Arkh Patol 2019; 81:5-15. [PMID: 31851187 DOI: 10.17116/patol2019810615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) is a congenital disease caused by mutations in a number of sarcomere proteins. According to the type of mutation, clinical observations record similar clinical manifestations, myocardial pathological changes, and the timing of manifestation of the disease in HCM patients. OBJECTIVE To study cardiomyocyte (CMC) ultrastructural changes in the interventricular septum (IVS) of patients with HCM and evaluate their specificity for this pathology. MATERIAL AND METHODS IVS myocardial samples taken from 44 HCM patients aged 18-59 years at IVS myoectomy underwent an electron microscopic study. The diameter of CMCs and their nuclei was measured in semithin sections. RESULTS A morphometric examination of the IVS myocardium in HCM patients revealed moderate hypertrophy of CMCs and their nuclei, the diameters of which averaged 23.7±4.4 and 5.2±0.9 μm, respectively. The IVS CMCs were characterized by the ultrastructural signs of hypertrophy: the larger size and number of structures ensuring contractile and synthetic functions; the myocytes contained higher amounts of myofibrils, intermyofibrillar mitochondria, granular endoplasmic reticulum cisterns, and free ribosomes. On the contrary, some CMCs had fewer myofibrils in the perinuclear region, which is an adaptive change under hemodynamic overload conditions. In addition, a number of myocytes displayed signs of dystrophic changes: the appearance of lipofuscin granules, myelin figures, phagosomes, lipid droplets, and vacuoles, which can fill all free sarcoplasmic zones. CONCLUSION Ultrastructural changes characteristic of hypertrophy were found in IVS CMCs in HCM patients. In addition, there was partial myofibrillar loss and dystrophic changes in a number of myocytes, which are stereotypic compensatory-adaptive changes under hemodynamic overload conditions. All the above-mentioned changes in the CMC ultrastructure are characteristic of myocardial hypertrophy, but not specific for hypertrophic cardiomyopathy.
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Affiliation(s)
- T V Sukhacheva
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Ministry of Health of Russia, Moscow, Russia
| | - R A Serov
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Ministry of Health of Russia, Moscow, Russia
| | - L A Bockeria
- A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Ministry of Health of Russia, Moscow, Russia
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12
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Jin N, Wang Y, Liu L, Xue F, Jiang T, Xu M. Dysregulation of the Renin-Angiotensin System and Cardiometabolic Status in Mice Fed a Long-Term High-Fat Diet. Med Sci Monit 2019; 25:6605-6614. [PMID: 31523052 PMCID: PMC6738017 DOI: 10.12659/msm.914877] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background This study aimed to investigate the renin-angiotensin system (RAS) and cardiometabolic status in mice fed a long-term high-fat diet (HFD). Material/Methods C57BL/6J mice were randomly assigned to the control group on a normal diet (ND) (n=15) and the HFD group (n=15). Serum biomarkers were measured, including total cholesterol (TC), triglyceride (TG), insulin, glycated hemoglobin (HbA1c), brain natriuretic peptide (BNP), renin, angiotensin-converting enzyme (ACE), angiotensin II (Ang-II), Ang-II type 1 receptor (AT1R), and aldosterone. Cardiac histology was measured by the cross-sectional area (CSA) of cardiomyocytes and collagen deposition. Levels of myocardial intercalated disc (ICD) proteins and mRNA were analyzed by Western blot and real-time quantitative polymerase chain reaction (RT-qPCR), respectively. The localization of ICD proteins was evaluated by immunohistochemistry (IHC). Results Compared with ND, HFD resulted in increased blood glucose, body weight, TC, TG, HbA1c, insulin, and BNP and levels of serum ACE, Ang-II, aldosterone, AT1R, cardiomyocyte CSA, and interstitial collagen in the myocardium compared. Also, HFD significantly down-regulated connexin-43, and upregulated β-catenin, N-cadherin, and plakoglobin in the hearts of HFD mice compared with ND mice. However, the deposition of ICD proteins was not changed in the hearts of HFD mice compared with ND mice. Conclusions Long-term HFD in mice resulted in left ventricular hypertrophy, interstitial fibrosis, dysregulation of RAS, and abnormal expression of ICD proteins compared with ND mice, but did not affect the distribution of cardiomyocyte ICD proteins. Long-term HFD resulted in cardiac remodeling and altered expression of ICD proteins through RAS activation.
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Affiliation(s)
- Nana Jin
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education of China, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China (mainland)
| | - Yu Wang
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou, China (mainland)
| | - Lin Liu
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou, China (mainland)
| | - Feng Xue
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou, China (mainland)
| | - Tingbo Jiang
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou, China (mainland)
| | - Mingzhu Xu
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou, China (mainland)
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13
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Abstract
Hypertrophic cardiomyopathy (HCM) is a worldwide genetic heart disease and a common cause of sudden death in the young. Penetration of the implantable cardioverter-defibrillator (ICD) into this patient population over the past 20 years has made accurate selection of patients for primary prevention ICDs a priority. Consequently, a new paradigm has emerged in the management of this complex disease with ICD therapy responsible for a substantial decrease in overall HCM-related mortality (to 0.5%/y) and independent of patient age. Selection of candidates for ICDs has matured substantially with the formulation of an enhanced risk stratification algorithm. One or more contemporary risk markers judged major within a given patient’s clinical profile, in association with physician judgment and shared decision-making, is sufficient to consider a primary prevention ICD implant. An enhanced American College of Cardiology/American Heart Association risk factor model (including new contrast-magnetic resonance–based markers, such as left ventricular apical aneurysm) used prospectively to make ICD decisions proved to be 95% sensitive for identifying patients who would experience ≥1 appropriate device therapies terminating ventricular tachycardia/fibrillation. The number of HCM patients required to treat with ICDs to save 1 patient with abolition of lethal ventricular tachyarrhythmias was 6:1, similar to randomized defibrillator trials in other cardiomyopathies. In contrast to patients with ischemic heart disease, after ICD shock HCM patients rarely experience transformation to heart failure deterioration or sudden arrhythmic death. The mathematically derived risk score model proposed by the European Society of Cardiology was inferior for identifying high-risk patients susceptible to arrhythmic sudden death with a sensitivity of only 33%, leaving many patients exposed to the possibility of sudden death without ICDs. In conclusion, introduction of the ICD associated with a matured risk stratification algorithm has altered management strategy and clinical course of many HCM patients, making the likelihood of sudden death prevention a reality and fulfilling the aspiration of preservation of life and reduced mortality for this vulnerable patient population.
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Affiliation(s)
- Barry J. Maron
- From the HCM Institute, Division of Cardiology, Tufts Medical Center, Boston, MA
| | - Ethan J. Rowin
- From the HCM Institute, Division of Cardiology, Tufts Medical Center, Boston, MA
| | - Martin S. Maron
- From the HCM Institute, Division of Cardiology, Tufts Medical Center, Boston, MA
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14
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Popa-Fotea NM, Micheu MM, Bataila V, Scafa-Udriste A, Dorobantu L, Scarlatescu AI, Zamfir D, Stoian M, Onciul S, Dorobantu M. Exploring the Continuum of Hypertrophic Cardiomyopathy-From DNA to Clinical Expression. ACTA ACUST UNITED AC 2019; 55:medicina55060299. [PMID: 31234582 PMCID: PMC6630598 DOI: 10.3390/medicina55060299] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 06/20/2019] [Accepted: 06/20/2019] [Indexed: 12/29/2022]
Abstract
The concepts underlying hypertrophic cardiomyopathy (HCM) pathogenesis have evolved greatly over the last 60 years since the pioneering work of the British pathologist Donald Teare, presenting the autopsy findings of “asymmetric hypertrophy of the heart in young adults”. Advances in human genome analysis and cardiac imaging techniques have enriched our understanding of the complex architecture of the malady and shaped the way we perceive the illness continuum. Presently, HCM is acknowledged as “a disease of the sarcomere”, where the relationship between genotype and phenotype is not straightforward but subject to various genetic and nongenetic influences. The focus of this review is to discuss key aspects related to molecular mechanisms and imaging aspects that have prompted genotype–phenotype correlations, which will hopefully empower patient-tailored health interventions.
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Affiliation(s)
- Nicoleta Monica Popa-Fotea
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, Floreasca Street 8, 014461 Bucharest, Romania.
| | - Miruna Mihaela Micheu
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, Floreasca Street 8, 014461 Bucharest, Romania.
| | - Vlad Bataila
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, Floreasca Street 8, 014461 Bucharest, Romania.
| | - Alexandru Scafa-Udriste
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, Floreasca Street 8, 014461 Bucharest, Romania.
- Department 4-Cardiothoracic Pathology, University of Medicine and Pharmacy Carol Davila, Eroii Sanitari Bvd. 8, 050474 Bucharest, Romania.
| | - Lucian Dorobantu
- Cardiomyopathy Center, Monza Hospital, Tony Bulandra Street 27, 021968 Bucharest, Romania.
| | - Alina Ioana Scarlatescu
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, Floreasca Street 8, 014461 Bucharest, Romania.
| | - Diana Zamfir
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, Floreasca Street 8, 014461 Bucharest, Romania.
| | - Monica Stoian
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, Floreasca Street 8, 014461 Bucharest, Romania.
| | - Sebastian Onciul
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, Floreasca Street 8, 014461 Bucharest, Romania.
- Department 4-Cardiothoracic Pathology, University of Medicine and Pharmacy Carol Davila, Eroii Sanitari Bvd. 8, 050474 Bucharest, Romania.
| | - Maria Dorobantu
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, Floreasca Street 8, 014461 Bucharest, Romania.
- Department 4-Cardiothoracic Pathology, University of Medicine and Pharmacy Carol Davila, Eroii Sanitari Bvd. 8, 050474 Bucharest, Romania.
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15
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Upregulation of MMP-9 and CaMKII prompts cardiac electrophysiological changes that predispose denervated transplanted hearts to arrhythmogenesis after prolonged cold ischemic storage. Biomed Pharmacother 2019; 112:108641. [DOI: 10.1016/j.biopha.2019.108641] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 11/20/2022] Open
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16
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Jacobson JT. Arrhythmia Evaluation and Management. Cardiol Clin 2019; 37:55-62. [DOI: 10.1016/j.ccl.2018.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Ramachandra CJ, Mai Ja KPM, Lin YH, Shim W, Boisvert WA, Hausenloy DJ. INDUCED PLURIPOTENT STEM CELLS FOR MODELLING ENERGETIC ALTERATIONS IN HYPERTROPHIC CARDIOMYOPATHY. CONDITIONING MEDICINE 2019; 2:142-151. [PMID: 32457935 PMCID: PMC7250397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is one of the most commonly inherited cardiac disorders that manifests with increased ventricular wall thickening, cardiomyocyte hypertrophy, disarrayed myofibers and interstitial fibrosis. The major pathophysiological features include, diastolic dysfunction, obstruction of the left ventricular outflow tract and cardiac arrhythmias. Mutations in genes that encode mostly for sarcomeric proteins have been associated with HCM but, despite the abundant research conducted to decipher the molecular mechanisms underlying the disease, it remains unclear as to how a primary defect in the sarcomere could lead to secondary phenotypes such as cellular hypertrophy. Mounting evidence suggests energy deficiency could be an important contributor of disease pathogenesis as well. Various animal models of HCM have been generated for gaining deeper insight into disease pathogenesis, however species variation between animals and humans, as well as the limited availability of human myocardial samples, has encouraged researchers to seek alternative 'humanized' models. Using induced pluripotent stem cells (iPSCs), human cardiomyocytes (CMs) have been generated from patients with HCM for investigating disease mechanisms. While these HCM-iPSC models demonstrate most of the phenotypic traits, it is important to ascertain if they recapitulate all pathophysiological features, especially that of energy deficiency. In this review we discuss the currently established HCM-iPSC models with emphasis on altered energetics.
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Affiliation(s)
- Chrishan J.A. Ramachandra
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
- Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - K P Myu Mai Ja
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
| | - Ying-Hsi Lin
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
- Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Winston Shim
- Health and Social Sciences Cluster, Singapore Institute of Technology, Singapore
| | - William A. Boisvert
- Center for Cardiovascular Research, John A. Burns School of Medicine, University of Hawaii, USA
| | - Derek J. Hausenloy
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
- Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
- Yong Loo Lin School of Medicine, National University Singapore, Singapore
- The Hatter Cardiovascular Institute, University College London, London, UK
- The National Institute of Health Research University College London Hospitals Biomedical Research Centre, Research & Development, London, UK
- Tecnologico de Monterrey, Centro de Biotecnologia-FEMSA, Nuevo Leon, Mexico
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18
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Jordà P, García-Álvarez A. Hypertrophic cardiomyopathy: Sudden cardiac death risk stratification in adults. Glob Cardiol Sci Pract 2018; 2018:25. [PMID: 30393637 PMCID: PMC6209451 DOI: 10.21542/gcsp.2018.25] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
- Paloma Jordà
- Cardiology Department, Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Ana García-Álvarez
- Cardiology Department, Institut Clínic Cardiovascular, Hospital Clínic, Universitat de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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19
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Basheer WA, Shaw RM. Connexin 43 and CaV1.2 Ion Channel Trafficking in Healthy and Diseased Myocardium. Circ Arrhythm Electrophysiol 2018; 9:e001357. [PMID: 27266274 DOI: 10.1161/circep.115.001357] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 04/29/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Wassim A Basheer
- From the Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA (W.A.B., R.M.S.); and Department of Medicine, University of California Los Angeles (R.M.S.)
| | - Robin M Shaw
- From the Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA (W.A.B., R.M.S.); and Department of Medicine, University of California Los Angeles (R.M.S.).
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20
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Long H, Yang G, Ma K, Xiao Z, Ren X. [Effect of different electrical stimulation waves on orientation and alignment of adipose derived mesenchymal stem cells]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 2018; 31:853-861. [PMID: 29798532 DOI: 10.7507/1002-1892.201702027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Objective To investigate the effect of different electrical stimulation waves on orientation and alignment of adipose derived mesenchymal stem cells (ADSCs). Methods ADSCs were isolated from 5-week-old Sprague Dawley rats (weight, 100-150 g) and cultivated. The cells at passages 3-5 were inoculated to prepare cell climbing slices, subsequently was exposed to direct-current electrical stimulations (ES) at electric field strengths of 1, 2, 3, 4, 5, and 6 V/cm on a homemade electric field bioreactor (groups A1, A2, A3, A4, A5, and A6); at electric field strength of 6 V/cm, at 50% duty cycle, and at frequency of 1 and 2 Hz (groups B1 and B2) of square wave ES; at electric field strength of 6 V/cm, at pulse width of 2 ms, and at frequency of 1 and 2 Hz (groups C1 and C2) of biphasic pulse wave ES; and no ES was given as a control (group D). The changes of cellular morphology affected by applied ES were evaluated by time-lapse micropho-tography via inverted microscope. The cell alignment was evaluated via average orientation factor ( OF). The cytoske-leton of electric field treated ADSCs was characterized by rhodamine-phalloidin staining. The cell survival rates were assessed via cell live/dead staining and intracellular calcium activities were detected by calcium ion fluorescent staining. Results The response of ADSCs to ES was related to the direct-current electric field intensity. The higher the direct-current electric field intensity was, the more cells aligned perpendicular to the direction of electric field. At each time point, there was no obvious cell alignment in groups B1, B2 and C1, C2. The average OF of groups A5 and A6 were significantly higher than that of group D ( P<0.05), but no significant difference was found between other groups and group D ( P>0.05). The cytoskeleton staining showed that the cells of groups A5 and A6 exhibited a compact fascicular structure of cytoskeleton, and tended to be perpendicular to the direction of the electric field vector. The cellular survival rate of groups A4, A5, and A6 were significantly lower than that of group D ( P<0.05), but no significant difference was found between other groups and group D ( P>0.05). Calcium fluorescence staining showed that the fluorescence intensity of calcium ions in groups A4, A5, and A6 was slightly higher than that in group D, and no significant difference was found between other groups and group D. Conclusion The direct-current electric field stimulations with physiological electric field strength (5 V/cm and 6 V/cm) can induce the alignment of ADSCs, but no cell alignment is found under conditions of less than 5 V/cm direct-current electric field, square wave, and biphasic pulse wave stimulation. The cellular viability is negatively correlated with the electric field intensity.
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Affiliation(s)
- Haiyan Long
- Center of Engineering-Training, Chengdu Aeronautic Polytechnic, Chengdu Sichuan, 610100, P.R.China
| | - Gang Yang
- Department of Medical Information and Engineering, School of Electrical Engineering and Information, Sichuan University, Chengdu Sichuan, 610065,
| | - Kunlong Ma
- Department of Orthopaedics, Yongchuan Hospital, Chongqing Medical University, Yongchuan Chongqing, 402160, P.R.China
| | - Zhenghua Xiao
- Department of Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu Sichuan, 610041, P.R.China
| | - Xiaomei Ren
- Department of Medical Information and Engineering, School of Electrical Engineering and Information, Sichuan University, Chengdu Sichuan, 610065, P.R.China
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21
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Randhawa PK, Jaggi AS. Investigating the involvement of glycogen synthase kinase-3β and gap junction signaling in TRPV 1 and remote hind preconditioning-induced cardioprotection. Eur J Pharmacol 2017; 814:9-17. [PMID: 28755986 DOI: 10.1016/j.ejphar.2017.07.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/26/2017] [Accepted: 07/26/2017] [Indexed: 01/10/2023]
Abstract
Remote ischemic preconditioning (RIPC) is the phenomenon that harnesses the body's endogenous protective mechanisms against prolonged ischemia-reperfusion-induced injury. The present study aimed to explore the involvement of glycogen synthase kinase-3β and gap junction signaling in TRPV1 and remote hind preconditioning-induced cardioprotection. In the present study, four consecutive cycles (5min of ischemia-reperfusion) of remote hind limb preconditioning stimulus were delivered using a blood pressure cuff fastened at the inguinal level of the rat. The isolated rat hearts were mounted on the Langendorff's apparatus and were exposed to 30min of global ischemia-120min of reperfusion. Sustained ischemia-reperfusion led to cardiac injury that was assessed in terms of infarct size, LDH release, CK release, LVDP, +dp/dtmax, -dp/dtmin, heart rate and coronary flow rate. The pharmacological agents employed in the present study included capsaicin (10mg/kg) as TRPV1 channel activator, AR-A014418 (1 and 3mg/kg) as glycogen synthase kinase-3β inhibitor and carbenoxolone disodium (50 and 100mg/kg) as gap junction blocker. Remote hind limb, capsaicin and AR-A014418 preconditioning led to significant reduction in the infarct size, LDH release, CK release and improved LVDP, +dp/dtmax, -dp/dtmin, heart rate and coronary flow rate. However, remote hind limb, capsaicin and AR-A014418 preconditioning-induced cardioprotective effects were remarkably reduced in the presence of carbenoxolone (100mg/kg). This indicates that remote preconditioning stimulus probably activates TRPV1 channels that may inhibit glycogen synthase kinase-3β activity which subsequently enhances gap junction coupling to produce cardioprotective effects.
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Affiliation(s)
- Puneet Kaur Randhawa
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University Patiala, 147002 India
| | - Amteshwar Singh Jaggi
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University Patiala, 147002 India.
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Epifantseva I, Shaw RM. Intracellular trafficking pathways of Cx43 gap junction channels. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:40-47. [PMID: 28576298 DOI: 10.1016/j.bbamem.2017.05.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/19/2017] [Accepted: 05/25/2017] [Indexed: 12/11/2022]
Abstract
Gap Junction (GJ) channels, including the most common Connexin 43 (Cx43), have fundamental roles in excitable tissues by facilitating rapid transmission of action potentials between adjacent cells. For instance, synchronization during each heartbeat is regulated by these ion channels at the cardiomyocyte cell-cell border. Cx43 protein has a short half-life, and rapid synthesis and timely delivery of those proteins to particular subdomains are crucial for the cellular organization of gap junctions and maintenance of intracellular coupling. Impairment in gap junction trafficking contributes to dangerous complications in diseased hearts such as the arrhythmias of sudden cardiac death. Of recent interest are the protein-protein interactions with the Cx43 carboxy-terminus. These interactions have significant impact on the full length Cx43 lifecycle and also contribute to trafficking of Cx43 as well as possibly other functions. We are learning that many of the known non-canonical roles of Cx43 can be attributed to the recently identified six endogenous Cx43 truncated isoforms which are produced by internal translation. In general, alternative translation is a new leading edge for proteome expansion and therapeutic drug development. This review highlights recent mechanisms identified in the trafficking of gap junction channels, involvement of other proteins contributing to the delivery of channels to the cell-cell border, and understanding of possible roles of the newly discovered alternatively translated isoforms in Cx43 biology. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Irina Epifantseva
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Robin M Shaw
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.; Department of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA..
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Calcium dynamics in cardiac excitatory and non-excitatory cells and the role of gap junction. Math Biosci 2017; 289:51-68. [PMID: 28457965 DOI: 10.1016/j.mbs.2017.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Revised: 11/12/2016] [Accepted: 04/26/2017] [Indexed: 11/21/2022]
Abstract
Calcium ions aid in the generation of action potential in myocytes and are responsible for the excitation-contraction coupling of heart. The heart muscle has specialized patches of cells, called excitatory cells (EC) such as the Sino-atrial node cells capable of auto-generation of action potential and cells which receive signals from the excitatory cells, called non-excitatory cells (NEC) such as cells of the ventricular and auricular walls. In order to understand cardiac calcium homeostasis, it is, therefore, important to study the calcium dynamics taking into account both types of cardiac cells. Here we have developed a model to capture the calcium dynamics in excitatory and non-excitatory cells taking into consideration the gap junction mediated calcium ion transfer from excitatory cell to non-excitatory cell. Our study revealed that the gap junctional coupling between excitatory and non-excitatory cells plays important role in the calcium dynamics. It is observed that any reduction in the functioning of gap junction may result in abnormal calcium oscillations in NEC, even when the calcium dynamics is normal in EC cell. Sensitivity of gap junction is observed to be independent of the pacing rate and hence a careful monitoring is required to maintain normal cardiomyocyte condition. It also highlights that sarcoplasmic reticulum may not be always able to control the amount of cytoplasmic calcium under the condition of calcium overload.
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Wang Y, Tang Y, Zou Y, Wang D, Zhu L, Tian T, Wang J, Bao J, Hui R, Kang L, Song L, Wang J. Plasma level of big endothelin-1 predicts the prognosis in patients with hypertrophic cardiomyopathy. Int J Cardiol 2017; 243:283-289. [PMID: 28587741 DOI: 10.1016/j.ijcard.2017.03.162] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 03/24/2017] [Accepted: 03/31/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND Cardiac remodeling is one of major pathological process in hypertrophic cardiomyopathy (HCM). Endothelin-1 has been linked to cardiac remodeling. Big endothelin-1 is the precursor of endothelin-1. METHODS A total of 245 patients with HCM were enrolled from 1999 to 2011 and partitioned to low, middle and high level groups according to their plasma big endothelin-1 levels. RESULTS At baseline, significant associations were found between high level of big endothelin-1 and left atrium size, heart function and atrial fibrillation. Big endothelin-1 was positively correlated with N-terminal B-type natriuretic peptide (r=0.291, p<0.001) and late gadolinium enhancement (LGE) on magnetic resonance imaging (r=0.222, p=0.016). During a follow-up of 3 (range, 2-5) years, big endothelin-1 level was positively associated with the risks of all-cause mortality, cardiovascular death and progression to NYHA class 3 or 4 (p=0.020, 0.044 and 0.032, respectively). The rate of above events in the highest tertile were 18.1%, 15.7%, 24.2%, respectively. After adjusting for multiple factors related to survival and cardiac function, the significance remained in the association of big endothelin-1 with the risk of all-cause mortality (hazard ratio (HR)=4.94, 95% confidence interval (CI) 1.07-22.88; p=0.041) and progression to NYHA class 3 or 4 (HR=4.10, 95%CI 1.32-12.75, p=0.015). CONCLUSION Our study showed that high level of plasma big endothelin-1 predicted prognosis for patients with HCM and it can be added to the marker panel in stratifying HCM patients for giving treatment priority to those at high risk.
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Affiliation(s)
- Yilu Wang
- Department of ICU, China Meitan General Hospital, Beijing, China
| | - Yida Tang
- State Key Laboratory of Cardiovascular Diseases, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Yubao Zou
- State Key Laboratory of Cardiovascular Diseases, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Dong Wang
- State Key Laboratory of Cardiovascular Diseases, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Ling Zhu
- Department of Cardiology, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, China
| | - Tao Tian
- State Key Laboratory of Cardiovascular Diseases, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Jizheng Wang
- Sino-German Laboratory for Molecular Medicine, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Jingru Bao
- Center for Cardiovascular Diseases, PLA Navy General Hospital, Beijing, China
| | - Rutai Hui
- State Key Laboratory of Cardiovascular Diseases, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China; Sino-German Laboratory for Molecular Medicine, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Lianming Kang
- State Key Laboratory of Cardiovascular Diseases, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Lei Song
- State Key Laboratory of Cardiovascular Diseases, Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China; Sino-German Laboratory for Molecular Medicine, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
| | - Ji Wang
- Department of ICU, China Meitan General Hospital, Beijing, China.
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25
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Yang G, Long H, Ren X, Ma K, Xiao Z, Wang Y, Guo Y. Regulation of adipose-tissue-derived stromal cell orientation and motility in 2D- and 3D-cultures by direct-current electrical field. Dev Growth Differ 2017; 59:70-82. [PMID: 28185267 DOI: 10.1111/dgd.12340] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 02/05/2023]
Abstract
Cell alignment and motility play a critical role in a variety of cell behaviors, including cytoskeleton reorganization, membrane-protein relocation, nuclear gene expression, and extracellular matrix remodeling. Direct current electric field (EF) in vitro can direct many types of cells to align vertically to EF vector. In this work, we investigated the effects of EF stimulation on rat adipose-tissue-derived stromal cells (ADSCs) in 2D-culture on plastic culture dishes and in 3D-culture on various scaffold materials, including collagen hydrogels, chitosan hydrogels and poly(L-lactic acid)/gelatin electrospinning fibers. Rat ADSCs were exposed to various physiological-strength EFs in a homemade EF-bioreactor. Changes of morphology and movements of cells affected by applied EFs were evaluated by time-lapse microphotography, and cell survival rates and intracellular calcium oscillations were also detected. Results showed that EF facilitated ADSC morphological changes, under 6 V/cm EF strength, and that ADSCs in 2D-culture aligned vertically to EF vector and kept a good cell survival rate. In 3D-culture, cell galvanotaxis responses were subject to the synergistic effect of applied EF and scaffold materials. Fast cell movement and intracellular calcium activities were observed in the cells of 3D-culture. We believe our research will provide some experimental references for the future study in cell galvanotaxis behaviors.
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Affiliation(s)
- Gang Yang
- Department of Medical Information and Engineering, School of Electrical Engineering and Information, Sichuan University, Chengdu, 610065, China
| | - Haiyan Long
- Center of Engineering-Training, Chengdu Aeronautic Polytechnic, Chengdu, 610100, China
| | - Xiaomei Ren
- Department of Medical Information and Engineering, School of Electrical Engineering and Information, Sichuan University, Chengdu, 610065, China
| | - Kunlong Ma
- Department of Orthopaedics, Yongchuan Hospital, Chongqing Medical University, Chongqing, 402160, China
| | - Zhenghua Xiao
- Department of Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Ying Wang
- Department of Medical Information and Engineering, School of Electrical Engineering and Information, Sichuan University, Chengdu, 610065, China
| | - Yingqiang Guo
- Department of Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, 610041, China
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Waxse BJ, Sengupta P, Hesketh GG, Lippincott-Schwartz J, Buss F. Myosin VI facilitates connexin 43 gap junction accretion. J Cell Sci 2017; 130:827-840. [PMID: 28096472 PMCID: PMC5358335 DOI: 10.1242/jcs.199083] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/04/2017] [Indexed: 12/19/2022] Open
Abstract
In this study, we demonstrate myosin VI enrichment at Cx43 (also known as GJA1)-containing gap junctions (GJs) in heart tissue, primary cardiomyocytes and cell culture models. In primary cardiac tissue and in fibroblasts from the myosin VI-null mouse as well as in tissue culture cells transfected with siRNA against myosin VI, we observe reduced GJ plaque size with a concomitant reduction in intercellular communication, as shown by fluorescence recovery after photobleaching (FRAP) and a new method of selective calcein administration. Analysis of the molecular role of myosin VI in Cx43 trafficking indicates that myosin VI is dispensable for the delivery of Cx43 to the cell surface and connexon movement in the plasma membrane. Furthermore, we cannot corroborate clathrin or Dab2 localization at gap junctions and we do not observe a function for the myosin-VI-Dab2 complex in clathrin-dependent endocytosis of annular gap junctions. Instead, we found that myosin VI was localized at the edge of Cx43 plaques by using total internal reflection fluorescence (TIRF) microscopy and use FRAP to identify a plaque accretion defect as the primary manifestation of myosin VI loss in Cx43 homeostasis. A fuller understanding of this derangement may explain the cardiomyopathy or gliosis associated with the loss of myosin VI.
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Affiliation(s)
- Bennett J Waxse
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland 20892, USA.,Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 2XY, UK
| | - Prabuddha Sengupta
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland 20892, USA
| | - Geoffrey G Hesketh
- Mount Sinai Hospital, Lunenfeld-Tanenbaum Research Institute, Toronto, Ontario M5G 1X5, Canada
| | - Jennifer Lippincott-Schwartz
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland 20892, USA
| | - Folma Buss
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 2XY, UK
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Abstract
Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias.
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Affiliation(s)
- Christopher L-H Huang
- Physiological Laboratory and the Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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28
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Sukhacheva TV, Chudinovskikh YA, Eremeeva MV, Serov RA, Bockeria LA. Proliferative Potential of Cardiomyocytes in Hypertrophic Cardiomyopathy: Correlation with Myocardial Remodeling. Bull Exp Biol Med 2016; 162:160-169. [PMID: 27882462 DOI: 10.1007/s10517-016-3566-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Indexed: 01/07/2023]
Affiliation(s)
- T V Sukhacheva
- A. N. Bakulev Scientific Center for Cardiovascular Surgery, Ministry of Health of the Russian Federation, Moscow, Russia.
| | - Yu A Chudinovskikh
- A. N. Bakulev Scientific Center for Cardiovascular Surgery, Ministry of Health of the Russian Federation, Moscow, Russia
| | - M V Eremeeva
- A. N. Bakulev Scientific Center for Cardiovascular Surgery, Ministry of Health of the Russian Federation, Moscow, Russia
| | - R A Serov
- A. N. Bakulev Scientific Center for Cardiovascular Surgery, Ministry of Health of the Russian Federation, Moscow, Russia
| | - L A Bockeria
- A. N. Bakulev Scientific Center for Cardiovascular Surgery, Ministry of Health of the Russian Federation, Moscow, Russia
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Liu H, Qin W, Wang Z, Shao Y, Wang J, Borg TK, Gao BZ, Xu M. Disassembly of myofibrils and potential imbalanced forces on Z-discs in cultured adult cardiomyocytes. Cytoskeleton (Hoboken) 2016; 73:246-57. [PMID: 27072949 DOI: 10.1002/cm.21298] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 04/01/2016] [Accepted: 04/04/2016] [Indexed: 11/08/2022]
Abstract
Myofibrils are the main protein structures that generate force in the beating heart. Myofibril disassembly is related to many physiological and pathological processes. This study investigated, in a cultured rat adult cardiomyocyte model, the effect of force imbalance on myofibril disassembly. The imbalance of forces that were exerted on Z-discs was induced by the synergistic effect of broken intercalated discs and actin-myosin interaction. Cardiomyocytes with well-preserved intercalated discs were isolated from adult rat ventricles. The ultrastructure of cardiomyocyte was observed using a customized two-photon excitation fluorescence and second harmonic generation imaging system. The contraction of cardiomyocytes was recorded with a high-speed CCD camera, and the movement of cellular components was analyzed using a contractile imaging assay technique. The cardiomyocyte dynamic remodeling process was recorded using a time-lapse imaging system. The role of actin-myosin interaction in myofibril disassembly was investigated by incubating cardiomyocytes with blebbistatin (25 μM). Results demonstrated that the hierarchical disassembly process of myofibrils was initiated from cardiomyocyte free ends where intercalated discs had broken, during which the desmin network near the free cell ends was destroyed to release single myofibrils. Analysis of force (based on a schematic model of cardiomyocytes connected at intercalated discs) suggests that breaking of intercalated discs caused force imbalance on both sides of the Z-discs adjacent to the cell ends due to actin-myosin interaction. The damaged intercalated discs and actin-myosin interaction induced force imbalance on both sides of the Z-discs, which played an important role in the hierarchical disassembly of myofibrils. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Honghai Liu
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, 45267
| | - Wan Qin
- Department of Bioengineering and COMSET, Clemson University, Clemson, South Carolina, 29634
| | - Zhonghai Wang
- Department of Bioengineering and COMSET, Clemson University, Clemson, South Carolina, 29634
| | - Yonghong Shao
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Jingcai Wang
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, 45267
| | - Thomas K Borg
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina, 29425
| | - Bruce Z Gao
- Department of Bioengineering and COMSET, Clemson University, Clemson, South Carolina, 29634
| | - Meifeng Xu
- Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, 45267
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Tse G, Tse V, Yeo JM, Sun B. Atrial Anti-Arrhythmic Effects of Heptanol in Langendorff-Perfused Mouse Hearts. PLoS One 2016; 11:e0148858. [PMID: 26872148 PMCID: PMC4752503 DOI: 10.1371/journal.pone.0148858] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 01/24/2016] [Indexed: 12/24/2022] Open
Abstract
Acute effects of heptanol (0.1 to 2 mM) on atrial electrophysiology were explored in Langendorff-perfused mouse hearts. Left atrial bipolar electrogram or monophasic action potential recordings were obtained during right atrial stimulation. Regular pacing at 8 Hz elicited atrial activity in 11 out of 11 hearts without inducing atrial arrhythmias. Programmed electrical stimulation using a S1S2 protocol provoked atrial tachy-arrhythmias in 9 of 17 hearts. In the initially arrhythmic group, 2 mM heptanol exerted anti-arrhythmic effects (Fisher’s exact test, P < 0.05) and increased atrial effective refractory period (ERP) from 26.0 ± 1.9 to 57.1 ± 2.5 ms (ANOVA, P < 0.001) despite increasing activation latency from 18.7 ± 1.1 to 28.9 ± 2.1 ms (P < 0.001) and leaving action potential duration at 90% repolarization (APD90) unaltered (25.6 ± 1.2 vs. 27.2 ± 1.2 ms; P > 0.05), which led to increases in ERP/latency ratio from 1.4 ± 0.1 to 2.1 ± 0.2 and ERP/APD90 ratio from 1.0 ± 0.1 to 2.1 ± 0.2 (P < 0.001). In contrast, in the initially non-arrhythmic group, heptanol did not alter arrhythmogenicity, increased AERP from 47.3 ± 5.3 to 54.5 ± 3.1 ms (P < 0.05) and activation latency from 23.7 ± 2.2 to 31.3 ± 2.5 ms and did not alter APD90 (24.1 ± 1.2 vs. 25.0 ± 2.3 ms; P > 0.05), leaving both AERP/latency ratio (2.1 ± 0.3 vs. 1.9 ± 0.2; P > 0.05) and ERP/APD90 ratio (2.0 ± 0.2 vs. 2.1 ± 0.1; P > 0.05) unaltered. Lower heptanol concentrations (0.1, 0.5 and 1 mM) did not alter arrhythmogenicity or the above parameters. The present findings contrast with known ventricular pro-arrhythmic effects of heptanol associated with decreased ERP/latency ratio, despite increased ERP/APD ratio observed in both the atria and ventricles.
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Affiliation(s)
- Gary Tse
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China
| | - Vivian Tse
- Department of Physiology, McGill University, Montreal, Canada
| | - Jie Ming Yeo
- Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Bing Sun
- Department of Cardiology, Tongji University Affiliated Tongji Hospital, Shanghai, China
- * E-mail:
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Reduced expression of adherens and gap junction proteins can have a fundamental role in the development of heart failure following cardiac hypertrophy in rats. Exp Mol Pathol 2015; 100:167-76. [PMID: 26708424 DOI: 10.1016/j.yexmp.2015.12.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 12/12/2015] [Accepted: 12/15/2015] [Indexed: 10/22/2022]
Abstract
Hypertension causes cardiac hypertrophy, cardiac dysfunction and heart failure (HF). The mechanisms implicated in the transition from compensated to decompensated cardiac hypertrophy are not fully understood. This study was aimed to investigate whether alterations in the expression of intercalated disk proteins could contribute to the transition of compensated cardiac hypertrophy to dilated heart development that culminates in HF. Male rats were submitted to abdominal aortic constriction and at 90 days post surgery (dps), three groups were observed: sham-operated animals (controls), animals with hypertrophic hearts (HH) and animals with hypertrophic + dilated hearts (HD). Blood pressure was evaluated. The hearts were collected and Western blot and immunofluorescence were performed to desmoglein-2, desmocollin-2, N-cadherin, plakoglobin, Bcatenin, and connexin-43. Cardiac systolic function was evaluated using the Vevo 2100 ultrasound system. Data were considered significant when p b 0.05. Seventy percent of the animals presented with HH and 30% were HD at 90 dps. The blood pressure increased in both groups. The amount of desmoglein-2 and desmocollin-2 expression was increased in both groups and no difference was observed in either group. The expression of N-cadherin, plakoglobin and B-catenin increased in the HHgroup and decreased in the HDgroup; and connexin-43 decreased only in theHDgroup. Therewas no difference between the ejection fraction and fractional shortening at 30 and 60 dps; however, they were decreased in the HD group at 90 dps. We found that while some proteins have increased expression accompanied by the increase in the cell volume associated with preserved systolic cardiac function in theHHgroup, these same proteins had decreased expression evenwithout significant reduction in the cell volume associated with decreased systolic cardiac function in HD group. The increased expression of desmoglein-2 and desmocollin-2 in both the HH and HD groups could work as a protective compensatory mechanism, helping tomaintain the dilated heart.We can hypothesize that inappropriate intercellular mechanical and electrical coupling associated with necrosis and/or apoptosis are important factors contributing to the transition to HF.
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Basheer W, Shaw R. The "tail" of Connexin43: An unexpected journey from alternative translation to trafficking. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:1848-56. [PMID: 26526689 DOI: 10.1016/j.bbamcr.2015.10.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 10/13/2015] [Accepted: 10/20/2015] [Indexed: 12/23/2022]
Abstract
With each heartbeat, Connexin43 (Cx43) cell-cell communication gap junctions are needed to rapidly spread and coordinate excitation signals for an effective heart contraction. The correct formation and delivery of channels to their respective membrane subdomain is referred to as protein trafficking. Altered Cx43 trafficking is a dangerous complication of diseased myocardium which contributes to the arrhythmias of sudden cardiac death. Cx43 has also been found to regulate many other cellular processes that cannot be explained by cell-cell communication. We recently identified the existence of up to six endogenous internally translated Cx43 N-terminal truncated isoforms from the same full-length mRNA molecule. This is the first evidence that alternative translation is possible for human ion channels and in human heart. Interestingly, we found that these internally translated isoforms, more specifically the 20 kDa isoform (GJA1-20k), is important for delivery of Cx43 to its respective membrane subdomain. This review covers recent advances in Cx43 trafficking and potential importance of alternatively translated Cx43 truncated isoforms. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
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Affiliation(s)
- Wassim Basheer
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Robin Shaw
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Department of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
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CHEN GUIYING, ZHAO JIYI, LIU CHUNYAN, ZHANG YINA, HUO YANPING, ZHOU LIJUN. MG132 proteasome inhibitor upregulates the expression of connexin 43 in rats with adriamycin-induced heart failure. Mol Med Rep 2015; 12:7595-602. [DOI: 10.3892/mmr.2015.4337] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 06/23/2015] [Indexed: 11/06/2022] Open
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Meens MJ, Kwak BR, Duffy HS. Role of connexins and pannexins in cardiovascular physiology. Cell Mol Life Sci 2015; 72:2779-92. [PMID: 26091747 PMCID: PMC11113959 DOI: 10.1007/s00018-015-1959-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 06/11/2015] [Indexed: 12/26/2022]
Abstract
Connexins and pannexins form connexons, pannexons and membrane channels, which are critically involved in many aspects of cardiovascular physiology. For that reason, a vast number of studies have addressed the role of connexins and pannexins in the arterial and venous systems as well as in the heart. Moreover, a role for connexins in lymphatics has recently also been suggested. This review provides an overview of the current knowledge regarding the involvement of connexins and pannexins in cardiovascular physiology.
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Affiliation(s)
- Merlijn J. Meens
- Department of Pathology and Immunology, University of Geneva, Rue Michel-Servet 1, 1211 Geneva 4, Switzerland
- Department of Medical Specializations-Cardiology, University of Geneva, Geneva, Switzerland
| | - Brenda R. Kwak
- Department of Pathology and Immunology, University of Geneva, Rue Michel-Servet 1, 1211 Geneva 4, Switzerland
- Department of Medical Specializations-Cardiology, University of Geneva, Geneva, Switzerland
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Duchateau J, Cornolle C, Peyrou J, Ritter P, Pillois X, Réant P, Reynaud A, Landelle M, Lafitte S. Abnormal left ventricular contraction sequence in hypertrophic cardiomyopathy patients: first description of hypersynchrony and invert synchrony. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:1632-1639. [PMID: 25747939 DOI: 10.1016/j.ultrasmedbio.2015.01.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 01/27/2015] [Accepted: 01/28/2015] [Indexed: 06/04/2023]
Abstract
The aim of this study was to compare left ventricular contraction sequence in patients with hypertrophic cardiomyopathy (HCM) and healthy controls. Normal left ventricular contraction sequence in healthy controls exhibits an apex-to-base delay (ABD) contributing to efficient cardiac mechanics (physiologic asynchrony). Echocardiographic data from 20 controls and 40 HCM patients were prospectively analyzed. Endocardial longitudinal and circumferential strains and ABD were measured using custom-built software. HCM patients had increased circumferential (-36.4 ± 6.0 vs. -32.9 ± 5.0, p < 0.01) and decreased longitudinal (-19.3 ± 6.4 vs. -23.4 ± 5.7, p < 0.01) strains. In controls, physiologic ABD was observed (35.7 ± 18.1 ms). This delay was reduced in HCM patients (5.5 ± 22.7 ms, p < 0.01 vs. controls). There was no interaction between ABD and common clinical or echocardiographic parameters in the HCM population. Left ventricular contraction sequence can be modified in HCM patients, with the loss of the physiologic ABD. This phenomenon is independent from commonly measured parameters.
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Affiliation(s)
- Josselin Duchateau
- Unité des cardiopathies valvulaires et laboratoire d'échocardiographie, Hôpital Cardiologique du Haut Lévèque, Pessac, France
| | - Claire Cornolle
- Unité des cardiopathies valvulaires et laboratoire d'échocardiographie, Hôpital Cardiologique du Haut Lévèque, Pessac, France
| | - Jérome Peyrou
- Unité des cardiopathies valvulaires et laboratoire d'échocardiographie, Hôpital Cardiologique du Haut Lévèque, Pessac, France
| | - Philippe Ritter
- Unité des cardiopathies valvulaires et laboratoire d'échocardiographie, Hôpital Cardiologique du Haut Lévèque, Pessac, France
| | - Xavier Pillois
- Unité des cardiopathies valvulaires et laboratoire d'échocardiographie, Hôpital Cardiologique du Haut Lévèque, Pessac, France
| | - Patricia Réant
- Unité des cardiopathies valvulaires et laboratoire d'échocardiographie, Hôpital Cardiologique du Haut Lévèque, Pessac, France
| | - Amélie Reynaud
- Unité des cardiopathies valvulaires et laboratoire d'échocardiographie, Hôpital Cardiologique du Haut Lévèque, Pessac, France
| | - Mathieu Landelle
- Unité des cardiopathies valvulaires et laboratoire d'échocardiographie, Hôpital Cardiologique du Haut Lévèque, Pessac, France
| | - Stéphane Lafitte
- Unité des cardiopathies valvulaires et laboratoire d'échocardiographie, Hôpital Cardiologique du Haut Lévèque, Pessac, France.
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Kessler EL, Boulaksil M, van Rijen HVM, Vos MA, van Veen TAB. Passive ventricular remodeling in cardiac disease: focus on heterogeneity. Front Physiol 2014; 5:482. [PMID: 25566084 PMCID: PMC4273631 DOI: 10.3389/fphys.2014.00482] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/24/2014] [Indexed: 12/20/2022] Open
Abstract
Passive ventricular remodeling is defined by the process of molecular ventricular adaptation to different forms of cardiac pathophysiology. It includes changes in tissue architecture, such as hypertrophy, fiber disarray, alterations in cell size and fibrosis. Besides that, it also includes molecular remodeling of gap junctions, especially those composed by Connexin43 proteins (Cx43) in the ventricles that affect cell-to-cell propagation of the electrical impulse, and changes in the sodium channels that modify excitability. All those alterations appear mainly in a heterogeneous manner, creating irregular and inhomogeneous electrical and mechanical coupling throughout the heart. This can predispose to reentry arrhythmias and adds to a further deterioration into heart failure. In this review, passive ventricular remodeling is described in Hypertrophic Cardiomyopathy (HCM), Dilated Cardiomyopathy (DCM), Ischemic Cardiomyopathy (ICM), and Arrhythmogenic Cardiomyopathy (ACM), with a main focus on the heterogeneity of those alterations mentioned above.
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Affiliation(s)
- Elise L Kessler
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht Utrecht, Netherlands
| | - Mohamed Boulaksil
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht Utrecht, Netherlands ; Department of Cardiology, Radboud University Medical Center Nijmegen, Netherlands
| | - Harold V M van Rijen
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht Utrecht, Netherlands
| | - Marc A Vos
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht Utrecht, 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 SS, Shaw RM. Trafficking highways to the intercalated disc: new insights unlocking the specificity of connexin 43 localization. ACTA ACUST UNITED AC 2014; 21:43-54. [PMID: 24460200 DOI: 10.3109/15419061.2013.876014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
With each heartbeat, billions of cardiomyocytes work in concert to propagate the electrical excitation needed to effectively circulate blood. Regulated expression and timely delivery of connexin proteins to form gap junctions at the specialized cell-cell contact region, known as the intercalated disc, is essential to ventricular cardiomyocyte coupling. We focus this review on several regulatory mechanisms that have been recently found to govern the lifecycle of connexin 43 (Cx43), the short-lived and most abundantly expressed connexin in cardiac ventricular muscle. The Cx43 lifecycle begins with gene expression, followed by oligomerization into hexameric channels, and then cytoskeletal-based transport toward the disc region. Once delivered, hemichannels interact with resident disc proteins and are organized to effect intercellular coupling. We highlight recent studies exploring regulation of Cx43 localization to the intercalated disc, with emphasis on alternatively translated Cx43 isoforms and cytoskeletal transport machinery that together regulate Cx43 gap junction coupling between cardiomyocytes.
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McCain ML, Desplantez T, Kléber AG. Engineering Cardiac Cell JunctionsIn Vitroto Study the Intercalated Disc. ACTA ACUST UNITED AC 2014; 21:181-91. [DOI: 10.3109/15419061.2014.905931] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Salameh A, Haunschild J, Bräuchle P, Peim O, Seidel T, Reitmann M, Kostelka M, Bakhtiary F, Dhein S, Dähnert I. On the role of the gap junction protein Cx43 (GJA1) in human cardiac malformations with Fallot-pathology. a study on paediatric cardiac specimen. PLoS One 2014; 9:e95344. [PMID: 24751918 PMCID: PMC3994046 DOI: 10.1371/journal.pone.0095344] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 03/25/2014] [Indexed: 12/16/2022] Open
Abstract
INTRODUCTION Gap junction channels are involved in growth and differentiation. Therefore, we wanted to elucidate if the main cardiac gap junction protein connexin43 (GJA1) is altered in patients with Tetralogy of Fallot or double-outlet right ventricle of Fallot-type (62 patients referred to as Fallot) compared to other cardiac anomalies (21 patients referred to as non-Fallot). Patients were divided into three age groups: 0-2years, 2-12years and >12years. Myocardial tissue samples were collected during corrective surgery and analysis of cell morphology, GJA1- and N-cadherin (CDH2)-distribution, as well as GJA1 protein- and mRNA-expression was carried out. Moreover, GJA1-gene analysis of 16 patients and 20 healthy subjects was performed. RESULTS Myocardial cell length and width were significantly increased in the oldest age group compared to the younger ones. GJA1 distribution changed significantly during maturation with the ratio of polar/lateral GJA1 increasing from 2.93±0.68 to 8.52±1.41. While in 0-2years old patients ∼6% of the lateral GJA1 was co-localised with CDH2 this decreased with age. Furthermore, the changes in cell morphology and GJA1-distribution were not due to the heart defect itself but were significantly dependent on age. Total GJA1 protein expression decreased during growing-up, whereas GJA1-mRNA remained unchanged. Sequencing of the GJA1-gene revealed only few heterozygous single nucleotide polymorphisms within the Fallot and the healthy control group. CONCLUSION During maturation significant changes in gap junction remodelling occur which might be necessary for the growing and developing heart. In our study point mutations within the Cx43-gene could not be identified as a cause of the development of TOF.
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Affiliation(s)
- Aida Salameh
- Clinic for Paediatric Cardiology, Heart Centre, University of Leipzig, Leipzig, Germany
- * E-mail:
| | - Josphina Haunschild
- Clinic for Cardiac Surgery, Heart Centre, University of Leipzig, Leipzig, Germany
| | - Paul Bräuchle
- Clinic for Paediatric Cardiology, Heart Centre, University of Leipzig, Leipzig, Germany
| | - Oliver Peim
- Clinic for Paediatric Cardiology, Heart Centre, University of Leipzig, Leipzig, Germany
| | - Thomas Seidel
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
| | - Marko Reitmann
- Clinic for Paediatric Cardiology, Heart Centre, University of Leipzig, Leipzig, Germany
| | - Martin Kostelka
- Clinic for Cardiac Surgery, Heart Centre, University of Leipzig, Leipzig, Germany
| | - Farhad Bakhtiary
- Clinic for Cardiac Surgery, Heart Centre, University of Leipzig, Leipzig, Germany
| | - Stefan Dhein
- Clinic for Cardiac Surgery, Heart Centre, University of Leipzig, Leipzig, Germany
| | - Ingo Dähnert
- Clinic for Paediatric Cardiology, Heart Centre, University of Leipzig, Leipzig, Germany
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Zhang X, Wang Q, Gablaski B, Zhang X, Lucchesi P, Zhao Y. A microdevice for studying intercellular electromechanical transduction in adult cardiac myocytes. LAB ON A CHIP 2013; 13:3090-7. [PMID: 23753064 PMCID: PMC3770274 DOI: 10.1039/c3lc50414j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Intercellular electromechanical transduction in adult cardiac myocytes plays an important role in regulating heart function. The efficiency of intercellular electromechanical transduction has so far been investigated only to a limited extent, which is largely due to the lack of appropriate tools that can quantitatively assess the contractile performance of interconnected adult cardiac myocytes. In this paper we report a microengineered device that is capable of applying electrical stimulation to the selected adult cardiac myocyte in a longitudinally connected cell doublet and quantifying the intercellular electromechanical transduction by measuring the contractile performance of stimulated and un-stimulated cells in the same doublet. The capability of applying selective electrical stimulation on only one cell in the doublet is validated by examining cell contractile performance while blocking the intercellular communication. Quantitative assessment of cell contractile performance in isolated adult cardiac myocytes is performed by measuring the change in cell length. The proof-of-concept assessment of gap junction performance shows that the device is useful in studying the efficiency of gap junctions in adult cardiac myocytes, which is most relevant to the synchronized pumping performance of native myocardium. Collectively, this work provides a quantitative tool for studying intercellular electromechanical transduction and is expected to develop a comprehensive understanding of the role of intercellular communication in various heart diseases.
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Affiliation(s)
- Xu Zhang
- Laboratory for Biomedical Microsystems, Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210 USA
| | - Qian Wang
- Laboratory for Biomedical Microsystems, Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210 USA
| | - Brian Gablaski
- Center for Cardiovascular and Pulmonary Research, Nationwide Children’s Hospital, Columbus, OH, 43205 USA
| | - Xiaojin Zhang
- Center for Cardiovascular and Pulmonary Research, Nationwide Children’s Hospital, Columbus, OH, 43205 USA
| | - Pamela Lucchesi
- Center for Cardiovascular and Pulmonary Research, Nationwide Children’s Hospital, Columbus, OH, 43205 USA
| | - Yi Zhao
- Laboratory for Biomedical Microsystems, Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210 USA
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McKeown PP, Muir AR. Risk assessment in hypertrophic cardiomyopathy: contemporary guidelines hampered by insufficient evidence. Heart 2013; 99:511-3. [PMID: 23376948 PMCID: PMC3607114 DOI: 10.1136/heartjnl-2012-303363] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Affiliation(s)
- Pascal P McKeown
- School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, Northern Ireland, UK
- Department of Cardiology, Royal Victoria Hospital, Belfast Health and Social Care Trust, Belfast, Northern Ireland, UK
| | - Alison Rachel Muir
- Department of Cardiology, Royal Victoria Hospital, Belfast Health and Social Care Trust, Belfast, Northern Ireland, UK
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O'Mahony C, Elliott P, McKenna W. Sudden cardiac death in hypertrophic cardiomyopathy. Circ Arrhythm Electrophysiol 2012; 6:443-51. [PMID: 23022709 DOI: 10.1161/circep.111.962043] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Constantinos O'Mahony
- The Inherited Cardiac Diseases Unit, The Heart Hospital/University College London, London, United Kingdom
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43
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On the different roles of AT1 and AT2 receptors in stretch-induced changes of connexin43 expression and localisation. Pflugers Arch 2012; 464:535-47. [PMID: 23007463 DOI: 10.1007/s00424-012-1161-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 09/12/2012] [Accepted: 09/13/2012] [Indexed: 10/27/2022]
Abstract
Cyclic mechanical stretch (CMS) and angiotensin II (ATII) play an important role in cardiac remodelling. Thus, we aimed to examine how ATII affects CMS-induced changes in localisation and expression of the gap junction protein connexin43 (Cx43). Neonatal rat cardiomyocytes cultured on gelatin-coated Flexcell cell culture plates were kept static or were exposed to CMS (110 % of resting length, 1 Hz) for 24 h with or without additional ATII (0.1 μmol/L). Moreover, inhibitors of ATII receptors (AT-R) were used (for AT(1)-R: losartan 0.1 μmol/L, for AT(2)-R: PD123177 0.1 μmol/L). Thereafter, the cardiomyocytes were investigated by immunohistology, PCR and Western blot. After 24 h of CMS, cardiomyocytes were significantly elongated and orientated 75 ± 1.6° nearly perpendicular to the stretch axis. Furthermore, CMS significantly accentuated Cx43 at the cell poles (ratio Cx43 polar/lateral static: 2.32 ± 0.17; CMS: 10.08 ± 3.2). Additional ATII application significantly reduced Cx43 polarisation (ratio Cx43 polar/lateral ATII: 4.61 ± 0.42). The combined administration of ATII and losartan to CMS further reduced Cx43 polarisation to control levels, whilst the AT(2)-R blocker PD123177 restored polarisation. Moreover, CMS and ATII application resulted in a significant Cx43 protein and Cx43 mRNA up-regulation which could be blocked by losartan but not by PD123177. Thus, CMS results in a self-organisation of the cardiomyocytes leading to elongated cells orientated transversely towards the stretch axis with enhanced Cx43 expression and Cx43 accentuation at the cell poles. ATII enhances total Cx43 mRNA and protein expression probably via AT(1)-R (=inhibitory effect of losartan) and reduces Cx43 polarisation presumably via AT(2)-R, since PD123177 (but not losartan) inhibited the negative effects of ATII on polarisation.
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44
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Disturbed myocardial connexin 43 and N-cadherin expressions in hypoplastic left heart syndrome and borderline left ventricle. J Thorac Cardiovasc Surg 2012; 144:1315-22. [PMID: 22405962 DOI: 10.1016/j.jtcvs.2012.02.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 01/25/2012] [Accepted: 02/03/2012] [Indexed: 11/22/2022]
Abstract
OBJECTIVES Borderline left ventricle is the left ventricular morphology at the favorable end of the hypoplastic left heart syndrome. In contrast to the severe end, it is suitable for biventricular repair. Wondering whether it is possible to identify cases suitable for biventricular repair from a developmental viewpoint, we investigated the myocardial histology of borderline and severely hypoplastic left ventricles. METHODS Postmortem specimens of neonatal, unoperated human hearts with severe hypoplastic left heart syndrome and borderline left ventricle were compared with normal specimens and hearts from patients with transposition of the great arteries. After tissue sampling of the lateral walls of both ventricles, immunohistochemical and immunofluorescence stainings against cardiac troponin I, N-cadherin, and connexin 43, important for proper cardiac differentiation, were done. RESULTS All severely hypoplastic left hearts (7/7) and most borderline left ventricle hearts (4/6) showed reduced sarcomeric expressions of troponin I in left and right ventricles. N-cadherin and connexin 43 expressions were reduced in intercalated disks. The remaining borderline left ventricle hearts (2/6) were histologically closer to control hearts. CONCLUSIONS Four of 6 borderline left ventricle hearts showed myocardial histopathology similar to the severely hypoplastic left hearts. The remainder were similar to normal hearts. Our results and knowledge regarding the role of epicardial-derived cells in myocardial differentiation lead us to postulate that an abnormal epicardial-myocardial interaction could explain the observed histopathology. Defining the histopathologic severity with preoperative myocardial biopsy samples of hearts with borderline left ventricle might provide a diagnostic tool for preoperative decision making.
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Salameh A, Dhein S. Effects of mechanical forces and stretch on intercellular gap junction coupling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:147-56. [PMID: 22245380 DOI: 10.1016/j.bbamem.2011.12.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 12/17/2011] [Accepted: 12/27/2011] [Indexed: 01/27/2023]
Abstract
Mechanical forces provide fundamental physiological stimulus in living organisms. Recent investigations demonstrated how various types of mechanical load, like strain, pressure, shear stress, or cyclic stretch can affect cell biology and gap junction intercellular communication (GJIC). Depending on the cell type, the type of mechanical load and on strength and duration of application, these forces can induce hypertrophic processes and modulate the expression and function of certain connexins such as Cx43, while others such as Cx37 or Cx40 are reported to be less mechanosensitive. In particular, not only expression but also subcellular localization of Cx43 is altered in cardiomyocytes submitted to cyclic mechanical stretch resulting in the typical elongated cell shape with an accentuation of Cx43 at the cell poles. In the heart both cardiomyocytes and fibroblasts can alter their GJIC in response to mechanical load. In the vasculature both endothelial cells and smooth muscle cells are subject to strain and cyclic stretch resulting from the pulsatile flow. In addition, vascular endothelial cells are mainly affected by shear stress resulting from the blood flow parallel to their surface. These mechanical forces lead to a regulation of GJIC in vascular tissue. In bones, osteocytes and osteoblasts are coupled via gap junctions, which also react to mechanical forces. Since gap junctions are involved in regulation of cell growth and differentiation, the mechanosensitivity of the regulation of these channels might open new perspectives to explain how cells can respond to mechanical load, and how stretch induces self-organization of a cell layer which might have implications for embryology and the development of organs. This article is part of a Special Issue entitled: The Communicating junctions, roles and dysfunctions.
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Affiliation(s)
- Aida Salameh
- Clinic for Pediatric Cardiology, University of Leipzig, Heart Centre, Germany
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46
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Palatinus JA, Rhett JM, Gourdie RG. The connexin43 carboxyl terminus and cardiac gap junction organization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:1831-43. [PMID: 21856279 DOI: 10.1016/j.bbamem.2011.08.006] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2011] [Revised: 07/25/2011] [Accepted: 08/03/2011] [Indexed: 12/09/2022]
Abstract
The precise spatial order of gap junctions at intercalated disks in adult ventricular myocardium is thought vital for maintaining cardiac synchrony. Breakdown or remodeling of this order is a hallmark of arrhythmic disease of the heart. The principal component of gap junction channels between ventricular cardiomyocytes is connexin43 (Cx43). Protein-protein interactions and modifications of the carboxyl-terminus of Cx43 are key determinants of gap junction function, size, distribution and organization during normal development and in disease processes. Here, we review data on the role of proteins interacting with the Cx43 carboxyl-terminus in the regulation of cardiac gap junction organization, with particular emphasis on Zonula Occludens-1. The rapid progress in this area suggests that in coming years we are likely to develop a fuller understanding of the molecular mechanisms causing pathologic remodeling of gap junctions. With these advances come the promise of novel approach to the treatment of arrhythmia and the prevention of sudden cardiac death. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Affiliation(s)
- Joseph A Palatinus
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, USA
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Fontes MSC, van Veen TAB, de Bakker JMT, van Rijen HVM. Functional consequences of abnormal Cx43 expression in the heart. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:2020-9. [PMID: 21839722 DOI: 10.1016/j.bbamem.2011.07.039] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 07/23/2011] [Accepted: 07/28/2011] [Indexed: 11/26/2022]
Abstract
The major gap junction protein expressed in the heart, connexin43 (Cx43), is highly remodeled in the diseased heart. Usually, Cx43 is down-regulated and heterogeneously redistributed to the lateral sides of cardiomyocytes. Reverse remodeling of the impaired Cx43 expression could restore normal cardiac function and normalize electrical stability. In this review, the reduced and heterogeneous Cx43 expression in the heart will be addressed in hypertrophic, dilated and ischemic cardiomyopathy together with its functional consequences of conduction velocity slowing, dispersed impulse conduction, its interaction with fibrosis and propensity to generate arrhythmias. Finally, different therapies are discussed. Treatments aimed to improve the Cx43 expression levels show new potentially anti-arrhythmic therapies during heart failure, but those in the context of acute ischemia can be anti-arrhythmogenic at the cost of larger infarct sizes. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Affiliation(s)
- Magda S C Fontes
- Department of Medical Physiology, University Medical Center, Utrecht, The Netherlands
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48
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Vincentz JW, Barnes RM, Firulli AB. Hand factors as regulators of cardiac morphogenesis and implications for congenital heart defects. BIRTH DEFECTS RESEARCH. PART A, CLINICAL AND MOLECULAR TERATOLOGY 2011; 91:485-94. [PMID: 21462297 PMCID: PMC3119928 DOI: 10.1002/bdra.20796] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 01/06/2011] [Accepted: 02/02/2011] [Indexed: 11/08/2022]
Abstract
Almost 15 years of careful study have established the related basic Helix-Loop-Helix (bHLH) transcription factors Hand1 and Hand2 as critical for heart development across evolution. Hand factors make broad contributions, revealed through animal models, to the development of multiple cellular lineages that ultimately contribute to the heart. They perform critical roles in ventricular cardiomyocyte growth, differentiation, morphogenesis, and conduction. They are also important for the proper development of the cardiac outflow tract, epicardium, and endocardium. Molecularly, they function both through DNA binding and through protein-protein interactions, which are regulated transcriptionally, posttranscriptionally by microRNAs, and posttranslationally through phosphoregulation. Although direct Hand factor transcriptional targets are progressively being identified, confirmed direct targets of Hand factor transcriptional activity in the heart are limited. Identification of these targets will be critical to model the mechanisms by which Hand factor bHLH interactions affect developmental pathways. Improved understanding of Hand factor-mediated transcriptional cascades will be necessary to determine how Hand factor dysregulation translates to human disease phenotypes. This review summarizes the insight that animal models have provided into the regulation and function of these factors during heart development, in addition to the recent findings that suggest roles for HAND1 and HAND2 in human congenital heart disease.
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Affiliation(s)
- Joshua W. Vincentz
- Riley Heart Research Center, Wells Center for Pediatric Research, Division of Pediatric Cardiology, Departments of Anatomy, Biochemistry and Medical and Molecular Genetics, Indiana Medical School, 1044 W. Walnut St., Indianapolis, IN 46202-5225, USA
| | - Ralston M. Barnes
- Riley Heart Research Center, Wells Center for Pediatric Research, Division of Pediatric Cardiology, Departments of Anatomy, Biochemistry and Medical and Molecular Genetics, Indiana Medical School, 1044 W. Walnut St., Indianapolis, IN 46202-5225, USA
| | - Anthony B. Firulli
- Riley Heart Research Center, Wells Center for Pediatric Research, Division of Pediatric Cardiology, Departments of Anatomy, Biochemistry and Medical and Molecular Genetics, Indiana Medical School, 1044 W. Walnut St., Indianapolis, IN 46202-5225, USA
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Sato PY, Coombs W, Lin X, Nekrasova O, Green KJ, Isom LL, Taffet SM, Delmar M. Interactions between ankyrin-G, Plakophilin-2, and Connexin43 at the cardiac intercalated disc. Circ Res 2011; 109:193-201. [PMID: 21617128 DOI: 10.1161/circresaha.111.247023] [Citation(s) in RCA: 189] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
RATIONALE The early description of the intercalated disc defined 3 structures, all of them involved in cell-cell communication: desmosomes, gap junctions, and adherens junctions. Current evidence demonstrates that molecules not involved in providing a physical continuum between cells also populate the intercalated disc. Key among them is the voltage-gated sodium channel complex. An important component of this complex is the cytoskeletal adaptor protein Ankyrin-G (AnkG). OBJECTIVE To test the hypothesis that AnkG partners with desmosome and gap junction molecules and exerts a functional effect on intercellular communication in the heart. METHODS AND RESULTS We used a combination of microscopy, immunochemistry, patch-clamp, and optical mapping to assess the interactions between AnkG, Plakophilin-2, and Connexin43. Coimmunoprecipitation studies from rat heart lysate demonstrated associations between the 3 molecules. With the use of siRNA technology, we demonstrated that loss of AnkG expression caused significant changes in subcellular distribution and/or abundance of PKP2 and Connexin43 as well as a decrease in intercellular adhesion strength and electric coupling. Regulation of AnkG and of Na(v)1.5 by Plakophilin-2 was also demonstrated. Finally, optical mapping experiments in AnkG-silenced cells demonstrated a shift in the minimal frequency at which rate-dependence activation block was observed. CONCLUSIONS These experiments support the hypothesis that AnkG is a key functional component of the intercalated disc at the intersection of 3 complexes often considered independent: the voltage-gated sodium channel, gap junctions, and the cardiac desmosome. Possible implications to the pathophysiology of inherited arrhythmias (such as arrhythmogenic right ventricular cardiomyopathy) are discussed.
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Affiliation(s)
- Priscila Y Sato
- Division of Cardiovascular Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
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Kresh JY, Chopra A. Intercellular and extracellular mechanotransduction in cardiac myocytes. Pflugers Arch 2011; 462:75-87. [PMID: 21437600 DOI: 10.1007/s00424-011-0954-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Revised: 03/01/2011] [Accepted: 03/02/2011] [Indexed: 01/17/2023]
Abstract
Adult cardiomyocytes are terminally differentiated with minimal replicative capacity. Therefore, long-term preservation or enhancement of cardiac function depends on structural adaptation. Myocytes interact with the extracellular matrix, fibroblasts, and vascular cells and with each other (end to end; side to side). We review the current understanding of the mechanical determinants and environmental sensing systems that modulate and regulate myocyte molecular machinery and its structural organization. We feature the design and application of engineered cellular microenvironments to demonstrate the ability of cardiac cells to remodel their cytoskeletal organization and shape, including sarcomere/myofibrillar architectural topography. Cell shape-dependent functions result from complex mechanical interactions between the cytoskeleton architecture and external conditions, be they cell-cell or cell-extracellular matrix (ECM) adhesion contact-mediated. This mechanobiological perspective forms the basis for viewing the cardiomyocyte as a mechanostructural anisotropic continuum, exhibiting constant mechanosensory-driven self-regulated adjustment of the cytoskeleton through tight interplay between its force generation activity and concurrent cytoarchitectural remodeling. The unifying framework guiding this perspective is the observation that these emerging events and properties are initiated by and respond to cytoskeletal reorganization, regulated by cell-cell and cell-ECM adhesion and its corresponding (mutually interactive) signaling machinery. It is important for future studies to elucidate how cross talk between these mechanical signals is coordinated to control myocyte structure and function. Ultimately, understanding how the highly interactive mechanical signaling can give rise to phenotypic changes is critical for targeting the underlying pathways that contribute to cardiac remodeling associated with various forms of dilated and hypertrophic myopathies, myocardial infarction, heart failure, and reverse remodeling.
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Affiliation(s)
- J Yasha Kresh
- Department of Cardiothoracic Surgery, Drexel University College of Medicine, 245 North 15th Street, MS 111, Philadelphia, PA 19102, USA.
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