1
|
Erbacher C, Britz S, Dinkel P, Klein T, Sauer M, Stigloher C, Üçeyler N. Interaction of human keratinocytes and nerve fiber terminals at the neuro-cutaneous unit. eLife 2024; 13:e77761. [PMID: 38225894 PMCID: PMC10791129 DOI: 10.7554/elife.77761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 12/19/2023] [Indexed: 01/17/2024] Open
Abstract
Traditionally, peripheral sensory neurons are assumed as the exclusive transducers of external stimuli. Current research moves epidermal keratinocytes into focus as sensors and transmitters of nociceptive and non-nociceptive sensations, tightly interacting with intraepidermal nerve fibers at the neuro-cutaneous unit. In animal models, epidermal cells establish close contacts and ensheath sensory neurites. However, ultrastructural morphological and mechanistic data examining the human keratinocyte-nerve fiber interface are sparse. We investigated this exact interface in human skin applying super-resolution array tomography, expansion microscopy, and structured illumination microscopy. We show keratinocyte ensheathment of afferents and adjacent connexin 43 contacts in native skin and have applied a pipeline based on expansion microscopy to quantify these parameter in skin sections of healthy participants versus patients with small fiber neuropathy. We further derived a fully human co-culture system, visualizing ensheathment and connexin 43 plaques in vitro. Unraveling human intraepidermal nerve fiber ensheathment and potential interaction sites advances research at the neuro-cutaneous unit. These findings are crucial on the way to decipher the mechanisms of cutaneous nociception.
Collapse
Affiliation(s)
| | - Sebastian Britz
- Imaging Core Facility, Biocenter, University of WürzburgWürzburgGermany
| | - Philine Dinkel
- Department of Neurology, University Hospital of WürzburgWürzburgGermany
| | - Thomas Klein
- Department of Neurology, University Hospital of WürzburgWürzburgGermany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, University of WürzburgWürzburgGermany
| | | | - Nurcan Üçeyler
- Department of Neurology, University Hospital of WürzburgWürzburgGermany
| |
Collapse
|
2
|
Moazzen H, Bolaji MD, Leube RE. Desmosomes in Cell Fate Determination: From Cardiogenesis to Cardiomyopathy. Cells 2023; 12:2122. [PMID: 37681854 PMCID: PMC10487268 DOI: 10.3390/cells12172122] [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: 07/18/2023] [Revised: 08/16/2023] [Accepted: 08/17/2023] [Indexed: 09/09/2023] Open
Abstract
Desmosomes play a vital role in providing structural integrity to tissues that experience significant mechanical tension, including the heart. Deficiencies in desmosomal proteins lead to the development of arrhythmogenic cardiomyopathy (AC). The limited availability of preventative measures in clinical settings underscores the pressing need to gain a comprehensive understanding of desmosomal proteins not only in cardiomyocytes but also in non-myocyte residents of the heart, as they actively contribute to the progression of cardiomyopathy. This review focuses specifically on the impact of desmosome deficiency on epi- and endocardial cells. We highlight the intricate cross-talk between desmosomal proteins mutations and signaling pathways involved in the regulation of epicardial cell fate transition. We further emphasize that the consequences of desmosome deficiency differ between the embryonic and adult heart leading to enhanced erythropoiesis during heart development and enhanced fibrogenesis in the mature heart. We suggest that triggering epi-/endocardial cells and fibroblasts that are in different "states" involve the same pathways but lead to different pathological outcomes. Understanding the details of the different responses must be considered when developing interventions and therapeutic strategies.
Collapse
Affiliation(s)
- Hoda Moazzen
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany; (M.D.B.); (R.E.L.)
| | | | | |
Collapse
|
3
|
Vielmuth F, Radeva MY, Yeruva S, Sigmund AM, Waschke J. cAMP: A master regulator of cadherin-mediated binding in endothelium, epithelium and myocardium. Acta Physiol (Oxf) 2023; 238:e14006. [PMID: 37243909 DOI: 10.1111/apha.14006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/05/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Regulation of cadherin-mediated cell adhesion is crucial not only for maintaining tissue integrity and barrier function in the endothelium and epithelium but also for electromechanical coupling within the myocardium. Therefore, loss of cadherin-mediated adhesion causes various disorders, including vascular inflammation and desmosome-related diseases such as the autoimmune blistering skin dermatosis pemphigus and arrhythmogenic cardiomyopathy. Mechanisms regulating cadherin-mediated binding contribute to the pathogenesis of diseases and may also be used as therapeutic targets. Over the last 30 years, cyclic adenosine 3',5'-monophosphate (cAMP) has emerged as one of the master regulators of cell adhesion in endothelium and, more recently, also in epithelial cells as well as in cardiomyocytes. A broad spectrum of experimental models from vascular physiology and cell biology applied by different generations of researchers provided evidence that not only cadherins of endothelial adherens junctions (AJ) but also desmosomal contacts in keratinocytes and the cardiomyocyte intercalated discs are central targets in this scenario. The molecular mechanisms involve protein kinase A- and exchange protein directly activated by cAMP-mediated regulation of Rho family GTPases and S665 phosphorylation of the AJ and desmosome adaptor protein plakoglobin. In line with this, phosphodiesterase 4 inhibitors such as apremilast have been proposed as a therapeutic strategy to stabilize cadherin-mediated adhesion in pemphigus and may also be effective to treat other disorders where cadherin-mediated binding is compromised.
Collapse
Affiliation(s)
- Franziska Vielmuth
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Mariya Y Radeva
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Sunil Yeruva
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Anna M Sigmund
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Jens Waschke
- Chair of Vegetative Anatomy, Institute of Anatomy, Faculty of Medicine, LMU Munich, Munich, Germany
| |
Collapse
|
4
|
Grandi E, Navedo MF, Saucerman JJ, Bers DM, Chiamvimonvat N, Dixon RE, Dobrev D, Gomez AM, Harraz OF, Hegyi B, Jones DK, Krogh-Madsen T, Murfee WL, Nystoriak MA, Posnack NG, Ripplinger CM, Veeraraghavan R, Weinberg S. Diversity of cells and signals in the cardiovascular system. J Physiol 2023; 601:2547-2592. [PMID: 36744541 PMCID: PMC10313794 DOI: 10.1113/jp284011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/19/2023] [Indexed: 02/07/2023] Open
Abstract
This white paper is the outcome of the seventh UC Davis Cardiovascular Research Symposium on Systems Approach to Understanding Cardiovascular Disease and Arrhythmia. This biannual meeting aims to bring together leading experts in subfields of cardiovascular biomedicine to focus on topics of importance to the field. The theme of the 2022 Symposium was 'Cell Diversity in the Cardiovascular System, cell-autonomous and cell-cell signalling'. Experts in the field contributed their experimental and mathematical modelling perspectives and discussed emerging questions, controversies, and challenges in examining cell and signal diversity, co-ordination and interrelationships involved in cardiovascular function. This paper originates from the topics of formal presentations and informal discussions from the Symposium, which aimed to develop a holistic view of how the multiple cell types in the cardiovascular system integrate to influence cardiovascular function, disease progression and therapeutic strategies. The first section describes the major cell types (e.g. cardiomyocytes, vascular smooth muscle and endothelial cells, fibroblasts, neurons, immune cells, etc.) and the signals involved in cardiovascular function. The second section emphasizes the complexity at the subcellular, cellular and system levels in the context of cardiovascular development, ageing and disease. Finally, the third section surveys the technological innovations that allow the interrogation of this diversity and advancing our understanding of the integrated cardiovascular function and dysfunction.
Collapse
Affiliation(s)
- Eleonora Grandi
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Manuel F. Navedo
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Jeffrey J. Saucerman
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Donald M. Bers
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Nipavan Chiamvimonvat
- Department of Pharmacology, University of California Davis, Davis, CA, USA
- Department of Internal Medicine, University of California Davis, Davis, CA, USA
| | - Rose E. Dixon
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
- Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Canada
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Ana M. Gomez
- Signaling and Cardiovascular Pathophysiology-UMR-S 1180, INSERM, Université Paris-Saclay, Orsay, France
| | - Osama F. Harraz
- Department of Pharmacology, Larner College of Medicine, and Vermont Center for Cardiovascular and Brain Health, University of Vermont, Burlington, VT, USA
| | - Bence Hegyi
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - David K. Jones
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Trine Krogh-Madsen
- Department of Physiology & Biophysics, Weill Cornell Medicine, New York, New York, USA
| | - Walter Lee Murfee
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Matthew A. Nystoriak
- Department of Medicine, Division of Environmental Medicine, Center for Cardiometabolic Science, University of Louisville, Louisville, KY, 40202, USA
| | - Nikki G. Posnack
- Department of Pediatrics, Department of Pharmacology and Physiology, The George Washington University, Washington, DC, USA
- Sheikh Zayed Institute for Pediatric and Surgical Innovation, Children’s National Heart Institute, Children’s National Hospital, Washington, DC, USA
| | | | - Rengasayee Veeraraghavan
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University – Wexner Medical Center, Columbus, OH, USA
| | - Seth Weinberg
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University – Wexner Medical Center, Columbus, OH, USA
| |
Collapse
|
5
|
Nielsen MS, van Opbergen CJM, van Veen TAB, Delmar M. The intercalated disc: a unique organelle for electromechanical synchrony in cardiomyocytes. Physiol Rev 2023; 103:2271-2319. [PMID: 36731030 PMCID: PMC10191137 DOI: 10.1152/physrev.00021.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
The intercalated disc (ID) is a highly specialized structure that connects cardiomyocytes via mechanical and electrical junctions. Although described in some detail by light microscopy in the 19th century, it was in 1966 that electron microscopy images showed that the ID represented apposing cell borders and provided detailed insight into the complex ID nanostructure. Since then, much has been learned about the ID and its molecular composition, and it has become evident that a large number of proteins, not all of them involved in direct cell-to-cell coupling via mechanical or gap junctions, reside at the ID. Furthermore, an increasing number of functional interactions between ID components are emerging, leading to the concept that the ID is not the sum of isolated molecular silos but an interacting molecular complex, an "organelle" where components work in concert to bring about electrical and mechanical synchrony. The aim of the present review is to give a short historical account of the ID's discovery and an updated overview of its composition and organization, followed by a discussion of the physiological implications of the ID architecture and the local intermolecular interactions. The latter will focus on both the importance of normal conduction of cardiac action potentials as well as the impact on the pathophysiology of arrhythmias.
Collapse
Affiliation(s)
- Morten S Nielsen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chantal J M van Opbergen
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
| | - Toon A B van Veen
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mario Delmar
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
| |
Collapse
|
6
|
De Bortoli M, Meraviglia V, Mackova K, Frommelt LS, König E, Rainer J, Volani C, Benzoni P, Schlittler M, Cattelan G, Motta BM, Volpato C, Rauhe W, Barbuti A, Zacchigna S, Pramstaller PP, Rossini A. Modeling incomplete penetrance in arrhythmogenic cardiomyopathy by human induced pluripotent stem cell derived cardiomyocytes. Comput Struct Biotechnol J 2023; 21:1759-1773. [PMID: 36915380 PMCID: PMC10006475 DOI: 10.1016/j.csbj.2023.02.029] [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: 11/14/2022] [Revised: 02/16/2023] [Accepted: 02/16/2023] [Indexed: 02/19/2023] Open
Abstract
Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) are commonly used to model arrhythmogenic cardiomyopathy (ACM), a heritable cardiac disease characterized by severe ventricular arrhythmias, fibrofatty myocardial replacement and progressive ventricular dysfunction. Although ACM is inherited as an autosomal dominant disease, incomplete penetrance and variable expressivity are extremely common, resulting in different clinical manifestations. Here, we propose hiPSC-CMs as a powerful in vitro model to study incomplete penetrance in ACM. Six hiPSC lines were generated from blood samples of three ACM patients carrying a heterozygous deletion of exon 4 in the PKP2 gene, two asymptomatic (ASY) carriers of the same mutation and one healthy control (CTR), all belonging to the same family. Whole exome sequencing was performed in all family members and hiPSC-CMs were examined by ddPCR, western blot, Wes™ immunoassay system, patch clamp, immunofluorescence and RNASeq. Our results show molecular and functional differences between ACM and ASY hiPSC-CMs, including a higher amount of mutated PKP2 mRNA, a lower expression of the connexin-43 protein, a lower overall density of sodium current, a higher intracellular lipid accumulation and sarcomere disorganization in ACM compared to ASY hiPSC-CMs. Differentially expressed genes were also found, supporting a predisposition for a fatty phenotype in ACM hiPSC-CMs. These data indicate that hiPSC-CMs are a suitable model to study incomplete penetrance in ACM.
Collapse
Key Words
- ABC, active ß-catenin
- ACM, arrhythmogenic cardiomyopathy
- ASY, asymptomatic
- Arrhythmogenic cardiomyopathy
- BBB, bundle-branch block
- CMs, cardiomyocytes
- CTR, control
- Cx43, connexin-43
- DEGs, differentially expressed genes
- GATK, Genome Analysis Toolkit
- Human induced pluripotent stem cell derived cardiomyocytes
- ICD, implantable cardioverter-defibrillator
- ID, intercalated disk
- Incomplete penetrance
- LBB, left bundle-branch block
- MRI, magnetic resonance imagingmut, mutated
- NSVT, non-sustained ventricular tachycardia
- RV, right ventricle
- hiPSC, human induced pluripotent stem cell
- wt, wild type
Collapse
Affiliation(s)
- Marzia De Bortoli
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Viviana Meraviglia
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy.,Department of Anatomy and Embryology, Leiden University Medical Center, 2316 Leiden, the Netherlands
| | - Katarina Mackova
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Laura S Frommelt
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Eva König
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Johannes Rainer
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Chiara Volani
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy.,Universita` degli Studi di Milano, The Cell Physiology MiLab, Department of Biosciences, Milano, Italy
| | - Patrizia Benzoni
- Universita` degli Studi di Milano, The Cell Physiology MiLab, Department of Biosciences, Milano, Italy
| | - Maja Schlittler
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Giada Cattelan
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Benedetta M Motta
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Claudia Volpato
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Werner Rauhe
- San Maurizio Hospital, Department of Cardiology, Bolzano, Italy
| | - Andrea Barbuti
- Universita` degli Studi di Milano, The Cell Physiology MiLab, Department of Biosciences, Milano, Italy
| | - Serena Zacchigna
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cardiovascular Biology Laboratory, Trieste, Italy
| | - Peter P Pramstaller
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Alessandra Rossini
- Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy
| |
Collapse
|
7
|
Yang HQ, Echeverry FA, ElSheikh A, Gando I, Anez Arredondo S, Samper N, Cardozo T, Delmar M, Shyng SL, Coetzee WA. Subcellular trafficking and endocytic recycling of K ATP channels. Am J Physiol Cell Physiol 2022; 322:C1230-C1247. [PMID: 35508187 PMCID: PMC9169827 DOI: 10.1152/ajpcell.00099.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/27/2022] [Accepted: 04/30/2022] [Indexed: 11/22/2022]
Abstract
Sarcolemmal/plasmalemmal ATP-sensitive K+ (KATP) channels have key roles in many cell types and tissues. Hundreds of studies have described how the KATP channel activity and ATP sensitivity can be regulated by changes in the cellular metabolic state, by receptor signaling pathways and by pharmacological interventions. These alterations in channel activity directly translate to alterations in cell or tissue function, that can range from modulating secretory responses, such as insulin release from pancreatic β-cells or neurotransmitters from neurons, to modulating contractile behavior of smooth muscle or cardiac cells to elicit alterations in blood flow or cardiac contractility. It is increasingly becoming apparent, however, that KATP channels are regulated beyond changes in their activity. Recent studies have highlighted that KATP channel surface expression is a tightly regulated process with similar implications in health and disease. The surface expression of KATP channels is finely balanced by several trafficking steps including synthesis, assembly, anterograde trafficking, membrane anchoring, endocytosis, endocytic recycling, and degradation. This review aims to summarize the physiological and pathophysiological implications of KATP channel trafficking and mechanisms that regulate KATP channel trafficking. A better understanding of this topic has potential to identify new approaches to develop therapeutically useful drugs to treat KATP channel-related diseases.
Collapse
Affiliation(s)
- Hua-Qian Yang
- Cyrus Tang Hematology Center, Soochow University, Suzhou, People's Republic of China
| | | | - Assmaa ElSheikh
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon
- Department of Medical Biochemistry, Tanta University, Tanta, Egypt
| | - Ivan Gando
- Department of Pathology, NYU School of Medicine, New York, New York
| | | | - Natalie Samper
- Department of Pathology, NYU School of Medicine, New York, New York
| | - Timothy Cardozo
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
| | - Mario Delmar
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
- Department of Medicine, NYU School of Medicine, New York, New York
| | - Show-Ling Shyng
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon
| | - William A Coetzee
- Department of Pathology, NYU School of Medicine, New York, New York
- Department of Neuroscience & Physiology, NYU School of Medicine, New York, New York
- Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
| |
Collapse
|
8
|
Zhang J, Liang Y, Bradford WH, Sheikh F. Desmosomes: emerging pathways and non-canonical functions in cardiac arrhythmias and disease. Biophys Rev 2021; 13:697-706. [PMID: 34765046 PMCID: PMC8555023 DOI: 10.1007/s12551-021-00829-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/12/2021] [Indexed: 12/14/2022] Open
Abstract
Desmosomes are critical adhesion structures in cardiomyocytes, with mutation/loss linked to the heritable cardiac disease, arrhythmogenic right ventricular cardiomyopathy (ARVC). Early studies revealed the ability of desmosomal protein loss to trigger ARVC disease features including structural remodeling, arrhythmias, and inflammation; however, the precise mechanisms contributing to diverse disease presentations are not fully understood. Recent mechanistic studies demonstrated the protein degradation component CSN6 is a resident cardiac desmosomal protein which selectively restricts cardiomyocyte desmosomal degradation and disease. This suggests defects in protein degradation can trigger the structural remodeling underlying ARVC. Additionally, a subset of ARVC-related mutations show enhanced vulnerability to calpain-mediated degradation, further supporting the relevance of these mechanisms in disease. Desmosomal gene mutations/loss has been shown to impact arrhythmogenic pathways in the absence of structural disease within ARVC patients and model systems. Studies have shown the involvement of connexins, calcium handling machinery, and sodium channels as early drivers of arrhythmias, suggesting these may be distinct pathways regulating electrical function from the desmosome. Emerging evidence has suggested inflammation may be an early mechanism in disease pathogenesis, as clinical reports have shown an overlap between myocarditis and ARVC. Recent studies focus on the association between desmosomal mutations/loss and inflammatory processes including autoantibodies and signaling pathways as a way to understand the involvement of inflammation in ARVC pathogenesis. A specific focus will be to dissect ongoing fields of investigation to highlight diverse pathogenic pathways associated with desmosomal mutations/loss.
Collapse
Affiliation(s)
- Jing Zhang
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Yan Liang
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - William H. Bradford
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Farah Sheikh
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| |
Collapse
|
9
|
Zhu Y, Shamblin I, Rodriguez E, Salzer GE, Araysi L, Margolies KA, Halade GV, Litovsky SH, Pogwizd S, Gray M, Huke S. Progressive cardiac arrhythmias and ECG abnormalities in the Huntington's disease BACHD mouse model. Hum Mol Genet 2021; 29:369-381. [PMID: 31816043 DOI: 10.1093/hmg/ddz295] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 11/11/2019] [Accepted: 12/05/2019] [Indexed: 02/03/2023] Open
Abstract
Huntington's disease (HD) is a dominantly inherited neurodegenerative disease. There is accumulating evidence that HD patients have increased prevalence of conduction abnormalities and compromised sinoatrial node function which could lead to increased risk for arrhythmia. We used mutant Huntingtin (mHTT) expressing bacterial artificial chromosome Huntington's disease mice to determine if they exhibit electrocardiogram (ECG) abnormalities involving cardiac conduction that are known to increase risk of sudden arrhythmic death in humans. We obtained surface ECGs and analyzed arrhythmia susceptibility; we observed prolonged QRS duration, increases in PVCs as well as PACs. Abnormal histological and structural changes that could lead to cardiac conduction system dysfunction were seen. Finally, we observed decreases in desmosomal proteins, plakophilin-2 and desmoglein-2, which have been reported to cause cardiac arrhythmias and reduced conduction. Our study indicates that mHTT could cause progressive cardiac conduction system pathology that could increase the susceptibility to arrhythmias and sudden cardiac death in HD patients.
Collapse
Affiliation(s)
- Yujie Zhu
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Isaac Shamblin
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Efrain Rodriguez
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Grace E Salzer
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Lita Araysi
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Katherine A Margolies
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Ganesh V Halade
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Silvio H Litovsky
- Department of Pathology, Division of Anatomic Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Steven Pogwizd
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Michelle Gray
- Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Sabine Huke
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| |
Collapse
|
10
|
Gasperetti A, James CA, Cerrone M, Delmar M, Calkins H, Duru F. Arrhythmogenic right ventricular cardiomyopathy and sports activity: from molecular pathways in diseased hearts to new insights into the athletic heart mimicry. Eur Heart J 2021; 42:1231-1243. [PMID: 33200174 DOI: 10.1093/eurheartj/ehaa821] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 07/12/2020] [Accepted: 09/24/2020] [Indexed: 12/14/2022] Open
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disease associated with a high risk of sudden cardiac death. Among other factors, physical exercise has been clearly identified as a strong determinant of phenotypic expression of the disease, arrhythmia risk, and disease progression. Because of this, current guidelines advise that individuals with ARVC should not participate in competitive or frequent high-intensity endurance exercise. Exercise-induced electrical and morphological para-physiological remodelling (the so-called 'athlete's heart') may mimic several of the classic features of ARVC. Therefore, the current International Task Force Criteria for disease diagnosis may not perform as well in athletes. Clear adjudication between the two conditions is often a real challenge, with false positives, that may lead to unnecessary treatments, and false negatives, which may leave patients unprotected, both of which are equally inacceptable. This review aims to summarize the molecular interactions caused by physical activity in inducing cardiac structural alterations, and the impact of sports on arrhythmia occurrence and other clinical consequences in patients with ARVC, and help the physicians in setting the two conditions apart.
Collapse
Affiliation(s)
- Alessio Gasperetti
- Division of Cardiology, University Heart Center Zurich, Rämistrasse 100, CH-8091 Zurich, Switzerland
| | - Cynthia A James
- Division of Cardiology, Johns Hopkins Hospital, 1800 Orleans St, Baltimore, MD 21287, USA
| | - Marina Cerrone
- Leon H Charney Division of Cardiology, New York University School of Medicine, 550 1st Avenue, New York, NY 10016, USA
| | - Mario Delmar
- Leon H Charney Division of Cardiology, New York University School of Medicine, 550 1st Avenue, New York, NY 10016, USA
| | - Hugh Calkins
- Division of Cardiology, Johns Hopkins Hospital, 1800 Orleans St, Baltimore, MD 21287, USA
| | - Firat Duru
- Division of Cardiology, University Heart Center Zurich, Rämistrasse 100, CH-8091 Zurich, Switzerland.,Center for Integrative Human Physiology, University of Zurich, Rämistrasse 71, Zurich 8006, Switzerland
| |
Collapse
|
11
|
Connexins in the Heart: Regulation, Function and Involvement in Cardiac Disease. Int J Mol Sci 2021; 22:ijms22094413. [PMID: 33922534 PMCID: PMC8122935 DOI: 10.3390/ijms22094413] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/12/2021] [Accepted: 04/20/2021] [Indexed: 12/20/2022] Open
Abstract
Connexins are a family of transmembrane proteins that play a key role in cardiac physiology. Gap junctional channels put into contact the cytoplasms of connected cardiomyocytes, allowing the existence of electrical coupling. However, in addition to this fundamental role, connexins are also involved in cardiomyocyte death and survival. Thus, chemical coupling through gap junctions plays a key role in the spreading of injury between connected cells. Moreover, in addition to their involvement in cell-to-cell communication, mounting evidence indicates that connexins have additional gap junction-independent functions. Opening of unopposed hemichannels, located at the lateral surface of cardiomyocytes, may compromise cell homeostasis and may be involved in ischemia/reperfusion injury. In addition, connexins located at non-canonical cell structures, including mitochondria and the nucleus, have been demonstrated to be involved in cardioprotection and in regulation of cell growth and differentiation. In this review, we will provide, first, an overview on connexin biology, including their synthesis and degradation, their regulation and their interactions. Then, we will conduct an in-depth examination of the role of connexins in cardiac pathophysiology, including new findings regarding their involvement in myocardial ischemia/reperfusion injury, cardiac fibrosis, gene transcription or signaling regulation.
Collapse
|
12
|
Super-resolution mapping of cellular double-strand break resection complexes during homologous recombination. Proc Natl Acad Sci U S A 2021; 118:2021963118. [PMID: 33707212 PMCID: PMC7980414 DOI: 10.1073/pnas.2021963118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Homologous recombination (HR) is a major pathway for repair of DNA double-strand breaks (DSBs). The initial step that drives the HR process is resection of DNA at the DSB, during which a multitude of nucleases, mediators, and signaling proteins accumulates at the damage foci in a manner that remains elusive. Using single-molecule localization super-resolution (SR) imaging assays, we specifically visualize the spatiotemporal behavior of key mediator and nuclease proteins as they resect DNA at single-ended double-strand breaks (seDSBs) formed at collapsed replication forks. By characterizing these associations, we reveal the in vivo dynamics of resection complexes involved in generating the long single-stranded DNA (ssDNA) overhang prior to homology search. We show that 53BP1, a protein known to antagonize HR, is recruited to seDSB foci during early resection but is spatially separated from repair activities. Contemporaneously, CtBP-interacting protein (CtIP) and MRN (MRE11-RAD51-NBS1) associate with seDSBs, interacting with each other and BRCA1. The HR nucleases EXO1 and DNA2 are also recruited and colocalize with each other and with the repair helicase Bloom syndrome protein (BLM), demonstrating multiple simultaneous resection events. Quantification of replication protein A (RPA) accumulation and ssDNA generation shows that resection is completed 2 to 4 h after break induction. However, both BRCA1 and BLM persist later into HR, demonstrating potential roles in homology search and repair resolution. Furthermore, we show that initial recruitment of BRCA1 and removal of Ku are largely independent of MRE11 exonuclease activity but dependent on MRE11 endonuclease activity. Combined, our observations provide a detailed description of resection during HR repair.
Collapse
|
13
|
Gerull B, Brodehl A. Genetic Animal Models for Arrhythmogenic Cardiomyopathy. Front Physiol 2020; 11:624. [PMID: 32670084 PMCID: PMC7327121 DOI: 10.3389/fphys.2020.00624] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/18/2020] [Indexed: 12/12/2022] Open
Abstract
Arrhythmogenic cardiomyopathy has been clinically defined since the 1980s and causes right or biventricular cardiomyopathy associated with ventricular arrhythmia. Although it is a rare cardiac disease, it is responsible for a significant proportion of sudden cardiac deaths, especially in athletes. The majority of patients with arrhythmogenic cardiomyopathy carry one or more genetic variants in desmosomal genes. In the 1990s, several knockout mouse models of genes encoding for desmosomal proteins involved in cell-cell adhesion revealed for the first time embryonic lethality due to cardiac defects. Influenced by these initial discoveries in mice, arrhythmogenic cardiomyopathy received an increasing interest in human cardiovascular genetics, leading to the discovery of mutations initially in desmosomal genes and later on in more than 25 different genes. Of note, even in the clinic, routine genetic diagnostics are important for risk prediction of patients and their relatives with arrhythmogenic cardiomyopathy. Based on improvements in genetic animal engineering, different transgenic, knock-in, or cardiac-specific knockout animal models for desmosomal and nondesmosomal proteins have been generated, leading to important discoveries in this field. Here, we present an overview about the existing animal models of arrhythmogenic cardiomyopathy with a focus on the underlying pathomechanism and its importance for understanding of this disease. Prospectively, novel mechanistic insights gained from the whole animal, organ, tissue, cellular, and molecular levels will lead to the development of efficient personalized therapies for treatment of arrhythmogenic cardiomyopathy.
Collapse
Affiliation(s)
- Brenda Gerull
- Comprehensive Heart Failure Center Wuerzburg, Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany.,Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
| | - Andreas Brodehl
- Erich and Hanna Klessmann Institute for Cardiovascular Research and Development, Heart and Diabetes Center NRW, University Hospitals of the Ruhr-University of Bochum, Bad Oeynhausen, Germany
| |
Collapse
|
14
|
Giacomelli E, Meraviglia V, Campostrini G, Cochrane A, Cao X, van Helden RWJ, Krotenberg Garcia A, Mircea M, Kostidis S, Davis RP, van Meer BJ, Jost CR, Koster AJ, Mei H, Míguez DG, Mulder AA, Ledesma-Terrón M, Pompilio G, Sala L, Salvatori DCF, Slieker RC, Sommariva E, de Vries AAF, Giera M, Semrau S, Tertoolen LGJ, Orlova VV, Bellin M, Mummery CL. Human-iPSC-Derived Cardiac Stromal Cells Enhance Maturation in 3D Cardiac Microtissues and Reveal Non-cardiomyocyte Contributions to Heart Disease. Cell Stem Cell 2020; 26:862-879.e11. [PMID: 32459996 PMCID: PMC7284308 DOI: 10.1016/j.stem.2020.05.004] [Citation(s) in RCA: 294] [Impact Index Per Article: 73.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/05/2020] [Accepted: 05/01/2020] [Indexed: 12/12/2022]
Abstract
Cardiomyocytes (CMs) from human induced pluripotent stem cells (hiPSCs) are functionally immature, but this is improved by incorporation into engineered tissues or forced contraction. Here, we showed that tri-cellular combinations of hiPSC-derived CMs, cardiac fibroblasts (CFs), and cardiac endothelial cells also enhance maturation in easily constructed, scaffold-free, three-dimensional microtissues (MTs). hiPSC-CMs in MTs with CFs showed improved sarcomeric structures with T-tubules, enhanced contractility, and mitochondrial respiration and were electrophysiologically more mature than MTs without CFs. Interactions mediating maturation included coupling between hiPSC-CMs and CFs through connexin 43 (CX43) gap junctions and increased intracellular cyclic AMP (cAMP). Scaled production of thousands of hiPSC-MTs was highly reproducible across lines and differentiated cell batches. MTs containing healthy-control hiPSC-CMs but hiPSC-CFs from patients with arrhythmogenic cardiomyopathy strikingly recapitulated features of the disease. Our MT model is thus a simple and versatile platform for modeling multicellular cardiac diseases that will facilitate industry and academic engagement in high-throughput molecular screening. Cardiac fibroblasts and endothelial cells induce hiPSC-cardiomyocyte maturation CX43 gap junctions form between cardiac fibroblasts and cardiomyocytes cAMP-pathway activation contributes to hiPSC-cardiomyocyte maturation Patient-derived hiPSC-cardiac fibroblasts cause arrhythmia in microtissues
Collapse
Affiliation(s)
- Elisa Giacomelli
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Viviana Meraviglia
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Giulia Campostrini
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Amy Cochrane
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Xu Cao
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Ruben W J van Helden
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Ana Krotenberg Garcia
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Maria Mircea
- Leiden Institute of Physics, Leiden University, 2333 Leiden, the Netherlands
| | - Sarantos Kostidis
- Center for Proteomics and Metabolomics, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Richard P Davis
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Berend J van Meer
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Carolina R Jost
- Department of Cell and Chemical Biology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Abraham J Koster
- Department of Cell and Chemical Biology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Hailiang Mei
- Sequencing Analysis Support Core, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - David G Míguez
- Centro de Biologia Molecular Severo Ochoa, Departamento de Física de la Materia Condensada, Instituto Nicolas Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Aat A Mulder
- Department of Cell and Chemical Biology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Mario Ledesma-Terrón
- Centro de Biologia Molecular Severo Ochoa, Departamento de Física de la Materia Condensada, Instituto Nicolas Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Giulio Pompilio
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino IRCCS, 20138 Milan, Italy; Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Luca Sala
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Daniela C F Salvatori
- Central Laboratory Animal Facility, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Roderick C Slieker
- Department of Cell and Chemical Biology, Leiden University Medical Center, 2333 Leiden, the Netherlands; Department of Epidemiology and Biostatistics, Amsterdam Public Health Institute, VU University Medical Center, 1007 Amsterdam, the Netherlands
| | - Elena Sommariva
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino IRCCS, 20138 Milan, Italy
| | - Antoine A F de Vries
- Department of Cardiology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Martin Giera
- Center for Proteomics and Metabolomics, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Stefan Semrau
- Leiden Institute of Physics, Leiden University, 2333 Leiden, the Netherlands
| | - Leon G J Tertoolen
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands
| | - Valeria V Orlova
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands.
| | - Milena Bellin
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands; Department of Biology, University of Padua, 35121 Padua, Italy; Veneto Institute of Molecular Medicine, 35129 Padua, Italy.
| | - Christine L Mummery
- Department of Anatomy and Embryology, Leiden University Medical Center, 2333 Leiden, the Netherlands; Department of Applied Stem Cell Technologies, University of Twente, 7500 Enschede, the Netherlands.
| |
Collapse
|
15
|
Abstract
Intercalated discs (ICDs) are highly orchestrated structures that connect neighboring cardiomyocytes in the heart. Three major complexes are distinguished in ICD: desmosome, adherens junction (AJ), and gap junction (GJ). Desmosomes are major cell adhesion junctions that anchor cell membrane to the intermediate filament network; AJs connect the actin cytoskeleton of adjacent cells; and gap junctions metabolically and electrically connect the cytoplasm of adjacent cardiomyocytes. All these complexes work as a single unit, the so-called area composita, interdependently rather than individually. Mutation or altered expression of ICD proteins results in various cardiac diseases, such as ARVC (arrhythmogenic right ventricular cardiomyopathy), dilated cardiomyopathy, and hypotrophy cardiomyopathy, eventually leading to heart failure. In this article, we first review the recent findings on the structural organization of ICD and their functions and then focus on the recent advances in molecular pathogenesis of the ICD-related heart diseases, which include two major areas: i) the ICD gene mutations in cardiac diseases, and ii) the involvement of ICD proteins in signal transduction pathways leading to myocardium remodeling and eventual heart failure. These major ICD-related signaling pathways include Wnt/β-catenin pathway, p38 MAPK cascade, Rho-dependent serum response factor (SRF) signaling, calcineurin/NFAT signaling, Hippo kinase cascade, etc., which are differentially regulated in pathological conditions.
Collapse
|
16
|
Abstract
Arrhythmogenic cardiomyopathy is a genetic disorder characterized by the risk of life-threatening arrhythmias, myocardial dysfunction and fibrofatty replacement of myocardial tissue. Mutations in genes that encode components of desmosomes, the adhesive junctions that connect cardiomyocytes, are the predominant cause of arrhythmogenic cardiomyopathy and can be identified in about half of patients with the condition. However, the molecular mechanisms leading to myocardial destruction, remodelling and arrhythmic predisposition remain poorly understood. Through the development of animal, induced pluripotent stem cell and other models of disease, advances in our understanding of the pathogenic mechanisms of arrhythmogenic cardiomyopathy over the past decade have brought several signalling pathways into focus. These pathways include canonical and non-canonical WNT signalling, the Hippo-Yes-associated protein (YAP) pathway and transforming growth factor-β signalling. These studies have begun to identify potential therapeutic targets whose modulation has shown promise in preclinical models. In this Review, we summarize and discuss the reported molecular mechanisms underlying the pathogenesis of arrhythmogenic cardiomyopathy.
Collapse
|
17
|
Yang HQ, Pérez-Hernández M, Sanchez-Alonso J, Shevchuk A, Gorelik J, Rothenberg E, Delmar M, Coetzee WA. Ankyrin-G mediates targeting of both Na + and K ATP channels to the rat cardiac intercalated disc. eLife 2020; 9:52373. [PMID: 31934859 PMCID: PMC7299345 DOI: 10.7554/elife.52373] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 01/11/2020] [Indexed: 12/12/2022] Open
Abstract
We investigated targeting mechanisms of Na+ and KATP channels to the intercalated disk (ICD) of cardiomyocytes. Patch clamp and surface biotinylation data show reciprocal downregulation of each other’s surface density. Mutagenesis of the Kir6.2 ankyrin binding site disrupts this functional coupling. Duplex patch clamping and Angle SICM recordings show that INa and IKATP functionally co-localize at the rat ICD, but not at the lateral membrane. Quantitative STORM imaging show that Na+ and KATP channels are localized close to each other and to AnkG, but not to AnkB, at the ICD. Peptides corresponding to Nav1.5 and Kir6.2 ankyrin binding sites dysregulate targeting of both Na+ and KATP channels to the ICD, but not to lateral membranes. Finally, a clinically relevant gene variant that disrupts KATP channel trafficking also regulates Na+ channel surface expression. The functional coupling between these two channels need to be considered when assessing clinical variants and therapeutics.
Collapse
Affiliation(s)
- Hua-Qian Yang
- Pediatrics, NYU School of Medicine, New York, United States
| | | | - Jose Sanchez-Alonso
- National Heart and Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, United Kingdom
| | - Andriy Shevchuk
- Department of Medicine, Imperial College London, London, United Kingdom
| | - Julia Gorelik
- National Heart and Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, United Kingdom
| | - Eli Rothenberg
- Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, United States
| | - Mario Delmar
- Medicine, NYU School of Medicine, New York, United States.,Cell Biology, NYU School of Medicine, New York, United States
| | - William A Coetzee
- Pediatrics, NYU School of Medicine, New York, United States.,Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, United States.,Neuroscience and Physiology, NYU School of Medicine, New York, United States
| |
Collapse
|
18
|
Green KJ, Jaiganesh A, Broussard JA. Desmosomes: Essential contributors to an integrated intercellular junction network. F1000Res 2019; 8. [PMID: 31942240 PMCID: PMC6944264 DOI: 10.12688/f1000research.20942.1] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/18/2019] [Indexed: 12/12/2022] Open
Abstract
The development of adhesive connections between cells was critical for the evolution of multicellularity and for organizing cells into complex organs with discrete compartments. Four types of intercellular junction are present in vertebrates: desmosomes, adherens junctions, tight junctions, and gap junctions. All are essential for the development of the embryonic layers and organs as well as adult tissue homeostasis. While each junction type is defined as a distinct entity, it is now clear that they cooperate physically and functionally to create a robust and functionally diverse system. During evolution, desmosomes first appeared in vertebrates as highly specialized regions at the plasma membrane that couple the intermediate filament cytoskeleton at points of strong cell–cell adhesion. Here, we review how desmosomes conferred new mechanical and signaling properties to vertebrate cells and tissues through their interactions with the existing junctional and cytoskeletal network.
Collapse
Affiliation(s)
- Kathleen J Green
- Departments of Pathology and Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.,Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL, USA
| | - Avinash Jaiganesh
- Departments of Pathology and Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Joshua A Broussard
- Departments of Pathology and Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.,Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL, USA
| |
Collapse
|
19
|
Calcium as a Key Player in Arrhythmogenic Cardiomyopathy: Adhesion Disorder or Intracellular Alteration? Int J Mol Sci 2019; 20:ijms20163986. [PMID: 31426283 PMCID: PMC6721231 DOI: 10.3390/ijms20163986] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 08/08/2019] [Accepted: 08/14/2019] [Indexed: 12/20/2022] Open
Abstract
Arrhythmogenic cardiomyopathy (ACM) is an inherited heart disease characterized by sudden death in young people and featured by fibro-adipose myocardium replacement, malignant arrhythmias, and heart failure. To date, no etiological therapies are available. Mutations in desmosomal genes cause abnormal mechanical coupling, trigger pro-apoptotic signaling pathways, and induce fibro-adipose replacement. Here, we discuss the hypothesis that the ACM causative mechanism involves a defect in the expression and/or activity of the cardiac Ca2+ handling machinery, focusing on the available data supporting this hypothesis. The Ca2+ toolkit is heavily remodeled in cardiomyocytes derived from a mouse model of ACM defective of the desmosomal protein plakophilin-2. Furthermore, ACM-related mutations were found in genes encoding for proteins involved in excitation‒contraction coupling, e.g., type 2 ryanodine receptor and phospholamban. As a consequence, the sarcoplasmic reticulum becomes more eager to release Ca2+, thereby inducing delayed afterdepolarizations and impairing cardiac contractility. These data are supported by preliminary observations from patient induced pluripotent stem-cell-derived cardiomyocytes. Assessing the involvement of Ca2+ signaling in the pathogenesis of ACM could be beneficial in the treatment of this life-threatening disease.
Collapse
|
20
|
Schinner C, Erber BM, Yeruva S, Waschke J. Regulation of cardiac myocyte cohesion and gap junctions via desmosomal adhesion. Acta Physiol (Oxf) 2019; 226:e13242. [PMID: 30582290 DOI: 10.1111/apha.13242] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/29/2018] [Accepted: 12/17/2018] [Indexed: 12/18/2022]
Abstract
AIMS Mutations in desmosomal proteins can induce arrhythmogenic cardiomyopathy with life-threatening arrhythmia. Previous data demonstrated adrenergic signalling to be important to regulate desmosomal cohesion in cardiac myocytes. Here, we investigated how signalling pathways including adrenergic signalling, PKC and SERCA regulate desmosomal adhesion and how this controls gap junctions (GJs) in cardiac myocytes. METHODS Immunostaining, Western blot, dissociation assay and multi-electrode array were applied in HL-1 cardiac myocytes to evaluate localization, expression and function of desmosomal and GJ components. cAMP levels were determined by ELISA. RESULTS Activation of PKC by PMA or adrenergic signalling increased cell cohesion and desmoglein-2 and desmoplakin localization at cell-cell junctions, whereas tryptophan (Trp) treatment to inhibit cadherin binding or inhibition of SERCA by thapsigargin reduced cell cohesion, while cAMP elevation rescued this effect. Despite no changes in protein expression, accumulation of GJ protein connexin-43 was detectable at cell-cell contacts in parallel to increased cohesion. Disruption of cell cohesion by Trp, PMA or thapsigargin impaired conduction of excitation comparable to GJ inhibition. cAMP elevation was effective to improve arrhythmia after Trp treatment. Weakened cell cohesion by Trp or depletion of desmoglein-2 or plakoglobin blocked signalling via the β1-adrenergic receptor. Moreover, silencing of desmosomal proteins increased arrhythmia and reduced conduction velocity, which were rescued by cAMP elevation. CONCLUSION These data demonstrate the interplay of GJs, desmosomes and the β1-adrenergic receptor with regulation of their function by cell cohesion, adrenergic and PKC signalling or SERCA inhibition. These results support the identification of new targets to treat arrhythmogenic cardiomyopathy.
Collapse
Affiliation(s)
- Camilla Schinner
- Faculty of Medicine; Ludwig-Maximilians-Universität (LMU) Munich; Munich Germany
- Department of Biomedicine; University of Basel; Basel Switzerland
| | - Bernd M. Erber
- Faculty of Medicine; Ludwig-Maximilians-Universität (LMU) Munich; Munich Germany
| | - Sunil Yeruva
- Faculty of Medicine; Ludwig-Maximilians-Universität (LMU) Munich; Munich Germany
| | - Jens Waschke
- Faculty of Medicine; Ludwig-Maximilians-Universität (LMU) Munich; Munich Germany
| |
Collapse
|
21
|
Novelli V, Malkani K, Cerrone M. Pleiotropic Phenotypes Associated With PKP2 Variants. Front Cardiovasc Med 2018; 5:184. [PMID: 30619891 PMCID: PMC6305316 DOI: 10.3389/fcvm.2018.00184] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 12/04/2018] [Indexed: 12/19/2022] Open
Abstract
Plakophilin-2 (PKP2) is a component of the desmosome complex and known for its role in cell-cell adhesion. Recently, alterations in the Pkp2 gene have been associated with different inherited cardiac conditions including Arrythmogenic Cardiomyopathy (ACM or ARVC), Brugada syndrome (BrS), and idiopathic ventricular fibrillation to name the most relevant. However, the assessment of pathogenicity regarding the genetic variations associated with Pkp2 is still a challenging task: the gene has a positive Residual Variation Intolerance Score and the potential deleterious role of several of its variants has been disputed. Limitations in facilitating interpretation and annotations of these variants are seen in the lack of segregation and clinical data in the control population of reference. In this review, we will provide a summary of all the currently available genetic information related to the Pkp2 gene, including different phenotypes, ClinVar annotations and data from large control database. Our goal is to provide a literature review that could help clinicians and geneticists in interpreting the role of Pkp2 variants in the context of heritable sudden death syndromes. Limitations of current algorithms and data repositories will be discussed.
Collapse
Affiliation(s)
- Valeria Novelli
- Centro Studi "Benito Stirpe" per la Prevenzione della Morte Improvvisa Nel Giovane Atleta, Institute of Genomic Medicine, Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - Kabir Malkani
- Leon H. Charney Division of Cardiology, NYU School of Medicine, New York, NY, United States
| | - Marina Cerrone
- Leon H. Charney Division of Cardiology, NYU School of Medicine, New York, NY, United States
| |
Collapse
|
22
|
Trembley MA, Quijada P, Agullo-Pascual E, Tylock KM, Colpan M, Dirkx RA, Myers JR, Mickelsen DM, de Mesy Bentley K, Rothenberg E, Moravec CS, Alexis JD, Gregorio CC, Dirksen RT, Delmar M, Small EM. Mechanosensitive Gene Regulation by Myocardin-Related Transcription Factors Is Required for Cardiomyocyte Integrity in Load-Induced Ventricular Hypertrophy. Circulation 2018; 138:1864-1878. [PMID: 29716942 PMCID: PMC6202206 DOI: 10.1161/circulationaha.117.031788] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Hypertrophic cardiomyocyte growth and dysfunction accompany various forms of heart disease. The mechanisms responsible for transcriptional changes that affect cardiac physiology and the transition to heart failure are not well understood. The intercalated disc (ID) is a specialized intercellular junction coupling cardiomyocyte force transmission and propagation of electrical activity. The ID is gaining attention as a mechanosensitive signaling hub and hotspot for causative mutations in cardiomyopathy. METHODS Transmission electron microscopy, confocal microscopy, and single-molecule localization microscopy were used to examine changes in ID structure and protein localization in the murine and human heart. We conducted detailed cardiac functional assessment and transcriptional profiling of mice lacking myocardin-related transcription factor (MRTF)-A and MRTF-B specifically in adult cardiomyocytes to evaluate the role of mechanosensitive regulation of gene expression in load-induced ventricular remodeling. RESULTS We found that MRTFs localize to IDs in the healthy human heart and accumulate in the nucleus in heart failure. Although mice lacking MRTFs in adult cardiomyocytes display normal cardiac physiology at baseline, pressure overload leads to rapid heart failure characterized by sarcomere disarray, ID disintegration, chamber dilation and wall thinning, cardiac functional decline, and partially penetrant acute lethality. Transcriptional profiling reveals a program of actin cytoskeleton and cardiomyocyte adhesion genes driven by MRTFs during pressure overload. Indeed, conspicuous remodeling of gap junctions at IDs identified by single-molecule localization microscopy may partially stem from a reduction in Mapre1 expression, which we show is a direct mechanosensitive MRTF target. CONCLUSIONS Our study describes a novel paradigm in which MRTFs control an acute mechanosensitive signaling circuit that coordinates cross-talk between the actin and microtubule cytoskeleton and maintains ID integrity and cardiomyocyte homeostasis in heart disease.
Collapse
MESH Headings
- Aged
- Animals
- Animals, Newborn
- COS Cells
- Case-Control Studies
- Chlorocebus aethiops
- Connexin 43/genetics
- Connexin 43/metabolism
- Female
- Gene Expression Regulation
- Heart Failure/genetics
- Heart Failure/metabolism
- Heart Failure/pathology
- Heart Failure/physiopathology
- Humans
- Hypertrophy, Left Ventricular/genetics
- Hypertrophy, Left Ventricular/metabolism
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/physiopathology
- Male
- Mechanotransduction, Cellular
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Confocal
- Microscopy, Electron, Transmission
- Microtubule-Associated Proteins/genetics
- Microtubule-Associated Proteins/metabolism
- Middle Aged
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/ultrastructure
- NIH 3T3 Cells
- Single Molecule Imaging
- Trans-Activators/deficiency
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Ventricular Function, Left
- Ventricular Remodeling
Collapse
Affiliation(s)
- Michael A. Trembley
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, NY
| | - Pearl Quijada
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, NY
| | - Esperanza Agullo-Pascual
- The Leon H Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Kevin M. Tylock
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY
| | - Mert Colpan
- Department of Cellular and Molecular Medicine, Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
| | - Ronald A. Dirkx
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, NY
| | - Jason R. Myers
- Genomics Research Center, University of Rochester, Rochester, NY
| | - Deanne M. Mickelsen
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, NY
| | | | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY
| | | | - Jeffrey D. Alexis
- Division of Cardiology, Department of Medicine, University of Rochester, Rochester, NY
| | - Carol C. Gregorio
- Department of Cellular and Molecular Medicine, Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
| | - Robert T. Dirksen
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY
| | - Mario Delmar
- The Leon H Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Eric M. Small
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, NY
- Department of Biomedical Engineering, University of Rochester, Rochester, NY
- Author for correspondence: Eric M. Small, Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box CVRI, Rochester, NY 14642, Phone: (585)276-7706, Fax: (585) 276-9839,
| |
Collapse
|
23
|
Luff SA, Kao CY, Papoutsakis ET. Role of p53 and transcription-independent p53-induced apoptosis in shear-stimulated megakaryocytic maturation, particle generation, and platelet biogenesis. PLoS One 2018; 13:e0203991. [PMID: 30231080 PMCID: PMC6145578 DOI: 10.1371/journal.pone.0203991] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 09/02/2018] [Indexed: 12/18/2022] Open
Abstract
Megakaryocytes (Mks) derive from hematopoietic stem and progenitor cells (HSPCs) in the bone marrow and develop into large, polyploid cells that eventually give rise to platelets. As Mks mature, they migrate from the bone marrow niche into the vasculature, where they are exposed to shear forces from blood flow, releasing Mk particles (platelet-like particles (PLPs), pro/preplatelets (PPTs), and Mk microparticles (MkMPs)) into circulation. We have previously shown that transcription factor p53 is important in Mk maturation, and that physiological levels of shear promote Mk particle generation and platelet biogenesis. Here we examine the role of p53 in the Mk shear-stress response. We show that p53 is acetylated in response to shear in both immature and mature Mks, and that decreased expression of deacetylase HDAC1, and increased expression of the acetyltransferases p300 and PCAF might be responsible for these changes. We also examined the hypothesis that p53 might be involved in the shear-induced Caspase 3 activation, phosphatidylserine (PS) externalization, and increased biogenesis of PLPs, PPTs, and MkMPs. We show that p53 is involved in all these shear-induced processes. We show that in response to shear, acetyl-p53 binds Bax, cytochrome c is released from mitochondria, and Caspase 9 is activated. We also show that shear-stimulated Caspase 9 activation and Mk particle biogenesis depend on transcription-independent p53-induced apoptosis (TIPA), but PS externalization is not. This is the first report to show that shear flow stimulates TIPA and that Caspase 9 activation and Mk-particle biogenesis are directly modulated by TIPA.
Collapse
Affiliation(s)
- Stephanie A. Luff
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States of America
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, United States of America
| | - Chen-Yuan Kao
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, United States of America
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, United States of America
| | - Eleftherios T. Papoutsakis
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States of America
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, United States of America
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, United States of America
| |
Collapse
|
24
|
Delmar M, Laird DW, Naus CC, Nielsen MS, Verselis VK, White TW. Connexins and Disease. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a029348. [PMID: 28778872 DOI: 10.1101/cshperspect.a029348] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Inherited or acquired alterations in the structure and function of connexin proteins have long been associated with disease. In the present work, we review current knowledge on the role of connexins in diseases associated with the heart, nervous system, cochlea, and skin, as well as cancer and pleiotropic syndromes such as oculodentodigital dysplasia (ODDD). Although incomplete by virtue of space and the extent of the topic, this review emphasizes the fact that connexin function is not only associated with gap junction channel formation. As such, both canonical and noncanonical functions of connexins are fundamental components in the pathophysiology of multiple connexin related disorders, many of them highly debilitating and life threatening. Improved understanding of connexin biology has the potential to advance our understanding of mechanisms, diagnosis, and treatment of disease.
Collapse
Affiliation(s)
- Mario Delmar
- The Leon H. Charney Division of Cardiology, New York University School of Medicine, New York, New York 10016
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario N6A5C1, Canada
| | - Christian C Naus
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Morten S Nielsen
- Department of Biological Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Vytautas K Verselis
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, New York 10461
| | - Thomas W White
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York 11790
| |
Collapse
|
25
|
Sorgen PL, Trease AJ, Spagnol G, Delmar M, Nielsen MS. Protein⁻Protein Interactions with Connexin 43: Regulation and Function. Int J Mol Sci 2018; 19:E1428. [PMID: 29748463 PMCID: PMC5983787 DOI: 10.3390/ijms19051428] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 12/11/2022] Open
Abstract
Connexins are integral membrane building blocks that form gap junctions, enabling direct cytoplasmic exchange of ions and low-molecular-mass metabolites between adjacent cells. In the heart, gap junctions mediate the propagation of cardiac action potentials and the maintenance of a regular beating rhythm. A number of connexin interacting proteins have been described and are known gap junction regulators either through direct effects (e.g., kinases) or the formation of larger multifunctional complexes (e.g., cytoskeleton scaffold proteins). Most connexin partners can be categorized as either proteins promoting coupling by stimulating forward trafficking and channel opening or inhibiting coupling by inducing channel closure, internalization, and degradation. While some interactions have only been implied through co-localization using immunohistochemistry, others have been confirmed by biophysical methods that allow detection of a direct interaction. Our understanding of these interactions is, by far, most well developed for connexin 43 (Cx43) and the scope of this review is to summarize our current knowledge of their functional and regulatory roles. The significance of these interactions is further exemplified by demonstrating their importance at the intercalated disc, a major hub for Cx43 regulation and Cx43 mediated effects.
Collapse
Affiliation(s)
- Paul L Sorgen
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Andrew J Trease
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Gaelle Spagnol
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Mario Delmar
- Leon H Charney Division of Cardiology, NYU School of Medicine, New York, NY 10016, USA.
| | - Morten S Nielsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark.
| |
Collapse
|
26
|
Vanslembrouck B, Kremer A, Pavie B, van Roy F, Lippens S, van Hengel J. Three-dimensional reconstruction of the intercalated disc including the intercellular junctions by applying volume scanning electron microscopy. Histochem Cell Biol 2018; 149:479-490. [PMID: 29508067 DOI: 10.1007/s00418-018-1657-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2018] [Indexed: 11/25/2022]
Abstract
The intercalated disc (ID) contains different kinds of intercellular junctions: gap junctions (GJs), desmosomes and areae compositae, essential for adhesion and communication between adjacent cardiomyocytes. The junctions can be identified based on their morphology when imaged using transmission electron microscopy (TEM), however, only with very limited information in the z-dimension. The application of volume EM techniques can give insight into the three-dimensional (3-D) organization of complex biological structures. In this study, we generated 3-D datasets using serial block-face scanning electron microscopy (SBF-SEM) and focused ion beam SEM (FIB-SEM), the latter resulting in datasets with 5 nm isotropic voxels. We visualized cardiomyocytes in murine ventricular heart tissue and, for the first time, we could three-dimensionally reconstruct the ID including desmosomes and GJs with 5 nm precision in a large volume. Results show in three dimensions a highly folded structure of the ID, with the presence of GJs and desmosomes in both plicae and interplicae regions. We observed close contact of GJs with mitochondria and a variable spatial distribution of the junctions. Based on measurements of the shape of the intercellular junctions in 3-D, it is seen that GJs and desmosomes vary in size, depending on the region within the ID. This demonstrates that volume EM is essential to visualize morphological changes and its potential to quantitatively determine structural changes between normal and pathological conditions, e.g., cardiomyopathies.
Collapse
Affiliation(s)
- Bieke Vanslembrouck
- Department of Basic Medical Science, Faculty of Medicine and Health Sciences, Ghent University, Corneel Heymanslaan 10, Building B, 9000, Ghent, Belgium
| | - Anna Kremer
- VIB BioImaging Core, Ghent, Belgium
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | | | - Frans van Roy
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Saskia Lippens
- VIB BioImaging Core, Ghent, Belgium
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Jolanda van Hengel
- Department of Basic Medical Science, Faculty of Medicine and Health Sciences, Ghent University, Corneel Heymanslaan 10, Building B, 9000, Ghent, Belgium.
| |
Collapse
|
27
|
Bartle EI, Rao TC, Urner TM, Mattheyses AL. Bridging the gap: Super-resolution microscopy of epithelial cell junctions. Tissue Barriers 2018; 6:e1404189. [PMID: 29420122 PMCID: PMC5823550 DOI: 10.1080/21688370.2017.1404189] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 10/26/2017] [Accepted: 10/30/2017] [Indexed: 02/02/2023] Open
Abstract
Cell junctions are critical for cell adhesion and communication in epithelial tissues. It is evident that the cellular distribution, size, and architecture of cell junctions play a vital role in regulating function. These details of junction architecture have been challenging to elucidate in part due to the complexity and size of cell junctions. A major challenge in understanding these features is attaining high resolution spatial information with molecular specificity. Fluorescence microscopy allows localization of specific proteins to junctions, but with a resolution on the same scale as junction size, rendering internal protein organization unobtainable. Super-resolution microscopy provides a bridge between fluorescence microscopy and nanoscale approaches, utilizing fluorescent tags to reveal protein organization below the resolution limit. Here we provide a brief introduction to super-resolution microscopy and discuss novel findings into the organization, structure and function of epithelial cell junctions.
Collapse
Affiliation(s)
- Emily I. Bartle
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tejeshwar C. Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tara M. Urner
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L. Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
28
|
Na V Channels: Assaying Biosynthesis, Trafficking, Function. Methods Mol Biol 2017. [PMID: 29264805 DOI: 10.1007/978-1-4939-7553-2_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Integral to the cell surface is channels, pumps, and exchanger proteins that facilitate the movement of ions across the membrane. Ion channels facilitate the passive movement of ions down an electrochemical gradient. Ion pumps actively use energy to actively translocate ions, often against concentration or voltage gradients, while ion exchangers utilize energy to couple the transport of different ion species such that one ion moves down its gradient and the released free energy is used to drive the movement of a different ion against its electrochemical gradient. Some ion pumps and exchangers may be electrogenic, i.e., the ion transport they support is not electrically neutral and generates a current. Functions of these pore-forming membrane proteins include the establishment of membrane potentials, gating of ions flows across the cell membrane to elicit action potentials and other electrical signals, as well as the regulation of cell volumes. The major forms of ion channels include voltage-, ligand-, and signal-gated channels. In this review, we describe mammalian voltage dependent Na (NaV) channels.
Collapse
|
29
|
Rivaud MR, Agullo-Pascual E, Lin X, Leo-Macias A, Zhang M, Rothenberg E, Bezzina CR, Delmar M, Remme CA. Sodium Channel Remodeling in Subcellular Microdomains of Murine Failing Cardiomyocytes. J Am Heart Assoc 2017; 6:JAHA.117.007622. [PMID: 29222390 PMCID: PMC5779058 DOI: 10.1161/jaha.117.007622] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Background Cardiac sodium channel (NaV1.5) dysfunction contributes to arrhythmogenesis during pathophysiological conditions. Nav1.5 localizes to distinct subcellular microdomains within the cardiomyocyte, where it associates with region‐specific proteins, yielding complexes whose function is location specific. We herein investigated sodium channel remodeling within distinct cardiomyocyte microdomains during heart failure. Methods and Results Mice were subjected to 6 weeks of transverse aortic constriction (TAC; n=32) to induce heart failure. Sham–operated on mice were used as controls (n=20). TAC led to reduced left ventricular ejection fraction, QRS prolongation, increased heart mass, and upregulation of prohypertrophic genes. Whole‐cell sodium current (INa) density was decreased by 30% in TAC versus sham–operated on cardiomyocytes. On macropatch analysis, INa in TAC cardiomyocytes was reduced by 50% at the lateral membrane (LM) and by 40% at the intercalated disc. Electron microscopy and scanning ion conductance microscopy revealed remodeling of the intercalated disc (replacement of [inter‐]plicate regions by large foldings) and LM (less identifiable T tubules and reduced Z‐groove ratios). Using scanning ion conductance microscopy, cell‐attached recordings in LM subdomains revealed decreased INa and increased late openings specifically at the crest of TAC cardiomyocytes, but not in groove/T tubules. Failing cardiomyocytes displayed a denser, but more stable, microtubule network (demonstrated by increased α‐tubulin and Glu‐tubulin expression). Superresolution microscopy showed reduced average NaV1.5 cluster size at the LM of TAC cells, in line with reduced INa. Conclusions Heart failure induces structural remodeling of the intercalated disc, LM, and microtubule network in cardiomyocytes. These adaptations are accompanied by alterations in NaV1.5 clustering and INa within distinct subcellular microdomains of failing cardiomyocytes.
Collapse
Affiliation(s)
- Mathilde R Rivaud
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, the Netherlands.,Division of Cardiology, New York University Medical Center, New York, NY.,Department of Medical Physiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | | | - Xianming Lin
- Division of Cardiology, New York University Medical Center, New York, NY
| | | | - Mingliang Zhang
- Division of Cardiology, New York University Medical Center, New York, NY
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, NYU-School of Medicine, New York, NY
| | - Connie R Bezzina
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, the Netherlands
| | - Mario Delmar
- Division of Cardiology, New York University Medical Center, New York, NY
| | - Carol Ann Remme
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, the Netherlands
| |
Collapse
|
30
|
Bermudez-Hernandez K, Keegan S, Whelan DR, Reid DA, Zagelbaum J, Yin Y, Ma S, Rothenberg E, Fenyö D. A Method for Quantifying Molecular Interactions Using Stochastic Modelling and Super-Resolution Microscopy. Sci Rep 2017; 7:14882. [PMID: 29093506 PMCID: PMC5665986 DOI: 10.1038/s41598-017-14922-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 10/19/2017] [Indexed: 02/05/2023] Open
Abstract
We introduce the Interaction Factor (IF), a measure for quantifying the interaction of molecular clusters in super-resolution microscopy images. The IF is robust in the sense that it is independent of cluster density, and it only depends on the extent of the pair-wise interaction between different types of molecular clusters in the image. The IF for a single or a collection of images is estimated by first using stochastic modelling where the locations of clusters in the images are repeatedly randomized to estimate the distribution of the overlaps between the clusters in the absence of interaction (IF = 0). Second, an analytical form of the relationship between IF and the overlap (which has the random overlap as its only parameter) is used to estimate the IF for the experimentally observed overlap. The advantage of IF compared to conventional methods to quantify interaction in microscopy images is that it is insensitive to changing cluster density and is an absolute measure of interaction, making the interpretation of experiments easier. We validate the IF method by using both simulated and experimental data and provide an ImageJ plugin for determining the IF of an image.
Collapse
Affiliation(s)
- Keria Bermudez-Hernandez
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
- Institute for Systems Genetics, New York University School of Medicine, New York, NY, USA
| | - Sarah Keegan
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
- Institute for Systems Genetics, New York University School of Medicine, New York, NY, USA
| | - Donna R Whelan
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Dylan A Reid
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Jennifer Zagelbaum
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Yandong Yin
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Sisi Ma
- Institute for Systems Genetics, New York University School of Medicine, New York, NY, USA
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA.
| | - David Fenyö
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA.
- Institute for Systems Genetics, New York University School of Medicine, New York, NY, USA.
| |
Collapse
|
31
|
Ribeiro-Rodrigues TM, Martins-Marques T, Morel S, Kwak BR, Girão H. Role of connexin 43 in different forms of intercellular communication - gap junctions, extracellular vesicles and tunnelling nanotubes. J Cell Sci 2017; 130:3619-3630. [PMID: 29025971 DOI: 10.1242/jcs.200667] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Communication is important to ensure the correct and efficient flow of information, which is required to sustain active social networks. A fine-tuned communication between cells is vital to maintain the homeostasis and function of multicellular or unicellular organisms in a community environment. Although there are different levels of complexity, intercellular communication, in prokaryotes to mammalians, can occur through secreted molecules (either soluble or encapsulated in vesicles), tubular structures connecting close cells or intercellular channels that link the cytoplasm of adjacent cells. In mammals, these different types of communication serve different purposes, may involve distinct factors and are mediated by extracellular vesicles, tunnelling nanotubes or gap junctions. Recent studies have shown that connexin 43 (Cx43, also known as GJA1), a transmembrane protein initially described as a gap junction protein, participates in all these forms of communication; this emphasizes the concept of adopting strategies to maximize the potential of available resources by reutilizing the same factor in different scenarios. In this Review, we provide an overview of the most recent advances regarding the role of Cx43 in intercellular communication mediated by extracellular vesicles, tunnelling nanotubes and gap junctions.
Collapse
Affiliation(s)
- Teresa M Ribeiro-Rodrigues
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-548 Coimbra, Portugal.,CNC.IBILI, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Tânia Martins-Marques
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-548 Coimbra, Portugal.,CNC.IBILI, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Sandrine Morel
- Dept. of Pathology and Immunology, and Dept. of Medical Specialties - Cardiology, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Brenda R Kwak
- Dept. of Pathology and Immunology, and Dept. of Medical Specialties - Cardiology, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Henrique Girão
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-548 Coimbra, Portugal .,CNC.IBILI, University of Coimbra, 3000-548 Coimbra, Portugal
| |
Collapse
|
32
|
Plakophilin-2 is required for transcription of genes that control calcium cycling and cardiac rhythm. Nat Commun 2017; 8:106. [PMID: 28740174 PMCID: PMC5524637 DOI: 10.1038/s41467-017-00127-0] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/02/2017] [Indexed: 12/19/2022] Open
Abstract
Plakophilin-2 (PKP2) is a component of the desmosome and known for its role in cell–cell adhesion. Mutations in human PKP2 associate with a life-threatening arrhythmogenic cardiomyopathy, often of right ventricular predominance. Here, we use a range of state-of-the-art methods and a cardiomyocyte-specific, tamoxifen-activated, PKP2 knockout mouse to demonstrate that in addition to its role in cell adhesion, PKP2 is necessary to maintain transcription of genes that control intracellular calcium cycling. Lack of PKP2 reduces expression of Ryr2 (coding for Ryanodine Receptor 2), Ank2 (coding for Ankyrin-B), Cacna1c (coding for CaV1.2) and Trdn (coding for triadin), and protein levels of calsequestrin-2 (Casq2). These factors combined lead to disruption of intracellular calcium homeostasis and isoproterenol-induced arrhythmias that are prevented by flecainide treatment. We propose a previously unrecognized arrhythmogenic mechanism related to PKP2 expression and suggest that mutations in PKP2 in humans may cause life-threatening arrhythmias even in the absence of structural disease. It is believed that mutations in desmosomal adhesion complex protein plakophilin 2 (PKP2) cause arrhythmia due to loss of cell-cell communication. Here the authors show that PKP2 controls the expression of proteins involved in calcium cycling in adult mouse hearts, and that lack of PKP2 can cause arrhythmia in a structurally normal heart.
Collapse
|
33
|
Moncayo-Arlandi J, Brugada R. Unmasking the molecular link between arrhythmogenic cardiomyopathy and Brugada syndrome. Nat Rev Cardiol 2017; 14:744-756. [DOI: 10.1038/nrcardio.2017.103] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
34
|
Spatio-temporal regulation of connexin43 phosphorylation and gap junction dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:83-90. [PMID: 28414037 DOI: 10.1016/j.bbamem.2017.04.008] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/05/2017] [Accepted: 04/11/2017] [Indexed: 01/23/2023]
Abstract
Gap junctions are specialized membrane domains containing tens to thousands of intercellular channels. These channels permit exchange of small molecules (<1000Da) including ions, amino acids, nucleotides, metabolites and secondary messengers (e.g., calcium, glucose, cAMP, cGMP, IP3) between cells. The common reductionist view of these structures is that they are composed entirely of integral membrane proteins encoded by the 21 member connexin human gene family. However, it is clear that the normal physiological function of this structure requires interaction and regulation by a variety of proteins, especially kinases. Phosphorylation is capable of directly modulating connexin channel function but the most dramatic effects on gap junction activity occur via the organization of the gap junction structures themselves. This is a direct result of the short half-life of the primary gap junction protein, connexin, which requires them to be constantly assembled, remodeled and turned over. The biological consequences of this remodeling are well illustrated during cardiac ischemia, a process wherein gap junctions are disassembled and remodeled resulting in arrhythmia and ultimately heart failure. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
Collapse
|
35
|
Akdis D, Brunckhorst C, Duru F, Saguner AM. Arrhythmogenic Cardiomyopathy: Electrical and Structural Phenotypes. Arrhythm Electrophysiol Rev 2016; 5:90-101. [PMID: 27617087 PMCID: PMC5013177 DOI: 10.15420/aer.2016.4.3] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 08/03/2016] [Indexed: 12/12/2022] Open
Abstract
This overview gives an update on the molecular mechanisms, clinical manifestations, diagnosis and therapy of arrhythmogenic cardiomyopathy (ACM). ACM is mostly hereditary and associated with mutations in genes encoding proteins of the intercalated disc. Three subtypes have been proposed: the classical right-dominant subtype generally referred to as ARVC/D, biventricular forms with early biventricular involvement and left-dominant subtypes with predominant LV involvement. Typical symptoms include palpitations, arrhythmic (pre)syncope and sudden cardiac arrest due to ventricular arrhythmias, which typically occur in athletes. At later stages, heart failure may occur. Diagnosis is established with the 2010 Task Force Criteria (TFC). Modern imaging tools are crucial for ACM diagnosis, including both echocardiography and cardiac magnetic resonance imaging for detecting functional and structural alternations. Of note, structural findings often become visible after electrical alterations, such as premature ventricular beats, ventricular fibrillation (VF) and ventricular tachycardia (VT). 12-lead ECG is important to assess for depolarisation and repolarisation abnormalities, including T-wave inversions as the most common ECG abnormality. Family history and the detection of causative mutations, mostly affecting the desmosome, have been incorporated in the TFC, and stress the importance of cascade family screening. Differential diagnoses include idiopathic right ventricular outflow tract (RVOT) VT, sarcoidosis, congenital heart disease, myocarditis, dilated cardiomyopathy, athlete's heart, Brugada syndrome and RV infarction. Therapeutic strategies include restriction from endurance and competitive sports, β-blockers, antiarrhythmic drugs, heart failure medication, implantable cardioverter-defibrillators and endocardial/epicardial catheter ablation.
Collapse
Affiliation(s)
- Deniz Akdis
- Department of Cardiology, University Heart Center, Zurich, Switzerland
| | | | - Firat Duru
- Department of Cardiology, University Heart Center, Zurich, Switzerland; Center for Integrative Human Physiology, University of Zurich, Switzerland
| | - Ardan M Saguner
- Department of Cardiology, University Heart Center, Zurich, Switzerland
| |
Collapse
|
36
|
Leo-Macias A, Agullo-Pascual E, Sanchez-Alonso JL, Keegan S, Lin X, Arcos T, Feng-Xia-Liang, Korchev YE, Gorelik J, Fenyö D, Rothenberg E, Rothenberg E, Delmar M. Nanoscale visualization of functional adhesion/excitability nodes at the intercalated disc. Nat Commun 2016; 7:10342. [PMID: 26787348 PMCID: PMC4735805 DOI: 10.1038/ncomms10342] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 12/01/2015] [Indexed: 02/06/2023] Open
Abstract
Intercellular adhesion and electrical excitability are considered separate cellular properties. Studies of myelinated fibres, however, show that voltage-gated sodium channels (VGSCs) aggregate with cell adhesion molecules at discrete subcellular locations, such as the nodes of Ranvier. Demonstration of similar macromolecular organization in cardiac muscle is missing. Here we combine nanoscale-imaging (single-molecule localization microscopy; electron microscopy; and ‘angle view' scanning patch clamp) with mathematical simulations to demonstrate distinct hubs at the cardiac intercalated disc, populated by clusters of the adhesion molecule N-cadherin and the VGSC NaV1.5. We show that the N-cadherin-NaV1.5 association is not random, that NaV1.5 molecules in these clusters are major contributors to cardiac sodium current, and that loss of NaV1.5 expression reduces intercellular adhesion strength. We speculate that adhesion/excitability nodes are key sites for crosstalk of the contractile and electrical molecular apparatus and may represent the structural substrate of cardiomyopathies in patients with mutations in molecules of the VGSC complex. In myelinated fibres conduction and adhesion proteins aggregate at discrete foci, but it is unclear if this organization is present in other excitable cells. Using nanoscale visualization and in silico techniques, the authors show that adhesion/excitability nodes exist at the intercalated discs of adult cardiac muscle.
Collapse
Affiliation(s)
- Alejandra Leo-Macias
- The Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, New York 10016, USA
| | - Esperanza Agullo-Pascual
- The Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, New York 10016, USA
| | - Jose L Sanchez-Alonso
- Imperial College, National Heart and Lung Institute, Department of Cardiac Medicine, Imperial Center for Translational and Experimental Medicine, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - Sarah Keegan
- Center for Health Informatics and Bioinformatics, NYU-SoM, Translational Research Building, 227 East 30th Street, New York, New York 10016, USA
| | - Xianming Lin
- The Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, New York 10016, USA
| | - Tatiana Arcos
- The Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, New York 10016, USA
| | - Feng-Xia-Liang
- Microscopy Core, NYU-SoM, 522 First Avenue, Skirball Institute, 2nd Floor, New York, New York 10016, USA
| | - Yuri E Korchev
- Division of Medicine, Imperial College, Hammersmith Campus, Du Cane Road, London, London W12 0NN, UK
| | - Julia Gorelik
- Imperial College, National Heart and Lung Institute, Department of Cardiac Medicine, Imperial Center for Translational and Experimental Medicine, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | - David Fenyö
- Center for Health Informatics and Bioinformatics, NYU-SoM, Translational Research Building, 227 East 30th Street, New York, New York 10016, USA
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, NYU-SoM, 522 First Avenue, MSB 3rd Floor, New York, New York 10016, USA
| | | | - Mario Delmar
- The Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, New York 10016, USA
| |
Collapse
|
37
|
Ongstad E, Kohl P. Fibroblast-myocyte coupling in the heart: Potential relevance for therapeutic interventions. J Mol Cell Cardiol 2016; 91:238-46. [PMID: 26774702 DOI: 10.1016/j.yjmcc.2016.01.010] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/09/2016] [Accepted: 01/11/2016] [Indexed: 01/03/2023]
Abstract
Cardiac myocyte-fibroblast electrotonic coupling is a well-established fact in vitro. Indirect evidence of its presence in vivo exists, but few functional studies have been published. This review describes the current knowledge of fibroblast-myocyte electrical signaling in the heart. Further research is needed to understand the frequency and extent of heterocellular interactions in vivo in order to gain a better understanding of their relevance in healthy and diseased myocardium. It is hoped that associated insight into myocyte-fibroblast coupling in the heart may lead to the discovery of novel therapeutic targets and the development of agents for improving outcomes of myocardial scarring and fibrosis.
Collapse
Affiliation(s)
- Emily Ongstad
- Clemson University, Department of Bioengineering, Clemson, SC, USA; Virginia Tech Carilion Research Institute, Roanoke, VA, USA.
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg - Bad Krozingen, Faculty of Medicine, University Freiburg, Germany; Cardiac Biophysics and Systems Biology, National Heart and Lung Institute, Imperial College London, UK
| |
Collapse
|
38
|
Leo-Macias A, Agullo-Pascual E, Delmar M. The cardiac connexome: Non-canonical functions of connexin43 and their role in cardiac arrhythmias. Semin Cell Dev Biol 2015; 50:13-21. [PMID: 26673388 DOI: 10.1016/j.semcdb.2015.12.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 12/01/2015] [Indexed: 12/17/2022]
Abstract
Connexin43 is the major component of gap junctions, an anatomical structure present in the cardiac intercalated disc that provides a low-resistance pathway for direct cell-to-cell passage of electrical charge. Recent studies have shown that in addition to its well-established function as an integral membrane protein that oligomerizes to form gap junctions, Cx43 plays other roles that are independent of channel (or perhaps even hemi-channel) formation. This article discusses non-canonical functions of Cx43. In particular, we focus on the role of Cx43 as a part of a protein interacting network, a connexome, where molecules classically defined as belonging to the mechanical junctions, the gap junctions and the sodium channel complex, multitask and work together to bring about excitability, electrical and mechanical coupling between cardiac cells. Overall, viewing Cx43 as a multi-functional protein, beyond gap junctions, opens a window to better understand the function of the intercalated disc and the pathological consequences that may result from changes in the abundance or localization of Cx43 in the intercalated disc subdomain.
Collapse
Affiliation(s)
- Alejandra Leo-Macias
- The Leon H Charney Division of Cardiology, New York University School of Medicine, New York, NY, United States
| | - Esperanza Agullo-Pascual
- The Leon H Charney Division of Cardiology, New York University School of Medicine, New York, NY, United States
| | - Mario Delmar
- The Leon H Charney Division of Cardiology, New York University School of Medicine, New York, NY, United States.
| |
Collapse
|
39
|
George SA, Poelzing S. Cardiac conduction in isolated hearts of genetically modified mice--Connexin43 and salts. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 120:189-98. [PMID: 26627143 DOI: 10.1016/j.pbiomolbio.2015.11.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/13/2015] [Accepted: 11/23/2015] [Indexed: 10/22/2022]
Abstract
Physiologic variations in perfusate composition have been identified as a new and important modulator of cardiac conduction velocity (CV), particularly when gap junctions (GJ) are reduced. We recently demonstrated in ex vivo hearts that perfusates with low sodium and high potassium preferentially slow ventricular CV in mice genetically engineered to express 50% less of the gap junction protein, connexin43 (Cx43). We also reported the possible role of calcium in modulating CV. In this review we discuss previous murine studies that explored the CV-GJ relationship in isolated mouse heart preparations with approximately 50% reduced Cx43. Studies were grouped according to the type of perfusate utilized, and CV during GJ uncoupling was compared. Studies in Group A preferentially used perfusates with low sodium, high potassium and non-physiologic calcium, and found CV slows and arrhythmias increase in mouse hearts with reduced Cx43. Studies in Group B used solutions with high sodium, low potassium and physiologic calcium, and did not observe CV slowing nor increased arrhythmia risk with loss of Cx3. Studies in Group C used solutions with low sodium, low potassium, physiologic calcium, creatine, taurine, and insulin. CV slowing was not observed, nor was arrhythmia risk increased with loss of Cx43. We suggest that perfusate ion composition may be a major determinant of whether CV slows when Cx43 is reduced. Furthermore, the review of these studies highlights important theoretical developments in the understanding of cardiac conduction and suggests that ionic milieu can conceal electrophysiologic remodeling secondary to reduced Cx43 expression as occurs in many cardiac diseases.
Collapse
Affiliation(s)
- Sharon A George
- Department of Biomedical Engineering and Mechanics, Virginia Tech Carilion Research Institute, and Center for Heart and Regenerative Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
| | - Steven Poelzing
- Department of Biomedical Engineering and Mechanics, Virginia Tech Carilion Research Institute, and Center for Heart and Regenerative Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
| |
Collapse
|
40
|
Akdis D, Medeiros-Domingo A, Gaertner-Rommel A, Kast JI, Enseleit F, Bode P, Klingel K, Kandolf R, Renois F, Andreoletti L, Akdis CA, Milting H, Lüscher TF, Brunckhorst C, Saguner AM, Duru F. Myocardial expression profiles of candidate molecules in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia compared to those with dilated cardiomyopathy and healthy controls. Heart Rhythm 2015; 13:731-41. [PMID: 26569459 DOI: 10.1016/j.hrthm.2015.11.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Indexed: 11/15/2022]
Abstract
BACKGROUND Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is mainly an autosomal dominant disease characterized by fibrofatty infiltration of the right ventricle, leading to ventricular arrhythmias. Mutations in desmosomal proteins can be identified in about half of the patients. The pathogenic mechanisms leading to disease expression remain unclear. OBJECTIVE The purpose of this study was to investigate myocardial expression profiles of candidate molecules involved in the pathogenesis of ARVC/D. METHODS Myocardial messenger RNA (mRNA) expression of 62 junctional molecules, 5 cardiac ion channel molecules, 8 structural molecules, 4 apoptotic molecules, and 6 adipogenic molecules was studied. The averaged expression of candidate mRNAs was compared between ARVC/D samples (n = 10), nonfamilial dilated cardiomyopathy (DCM) samples (n = 10), and healthy control samples (n = 8). Immunohistochemistry and quantitative protein expression analysis were performed. Genetic analysis using next generation sequencing was performed in all patients with ARVC/D. RESULTS Following mRNA levels were significantly increased in patients with ARVC/D compared to those with DCM and healthy controls: phospholamban (P ≤ .001 vs DCM; P ≤ .001 vs controls), healthy tumor protein 53 apoptosis effector (P = .001 vs DCM; P ≤ .001 vs controls), and carnitine palmitoyltransferase 1β (P ≤ .001 vs DCM; P = 0.008 vs controls). Plakophillin-2 (PKP-2) mRNA was downregulated in patients with ARVC/D with PKP-2 mutations compared with patients with ARVC/D without PKP-2 mutations (P = .04). Immunohistochemistry revealed significantly increased protein expression of phospholamban, tumor protein 53 apoptosis effector, and carnitine palmitoyltransferase 1β in patients with ARVC/D and decreased PKP-2 expression in patients with ARVC/D carrying a PKP-2 mutation. CONCLUSION Changes in the expression profiles of sarcolemmal calcium channel regulation, apoptosis, and adipogenesis suggest that these molecular pathways may play a critical role in the pathogenesis of ARVC/D, independent of the underlying genetic mutations.
Collapse
Affiliation(s)
- Deniz Akdis
- Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland
| | - Argelia Medeiros-Domingo
- Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland; Department of Cardiology, University Hospital Bern, Bern, Switzerland
| | | | - Jeannette I Kast
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zurich, Davos, Switzerland
| | - Frank Enseleit
- Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland
| | - Peter Bode
- Department of Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Karin Klingel
- Department of Molecular Pathology, University Hospital Tübingen, Tübingen, Germany
| | - Reinhard Kandolf
- Department of Molecular Pathology, University Hospital Tübingen, Tübingen, Germany
| | - Fanny Renois
- Laboratoire de Virologie Médicale et Moléculaire, EA 4684 CardioVir, Faculté de Médecine et CHU Robert Debré, Reims, France
| | - Laurent Andreoletti
- Laboratoire de Virologie Médicale et Moléculaire, EA 4684 CardioVir, Faculté de Médecine et CHU Robert Debré, Reims, France
| | - Cezmi A Akdis
- Swiss Institute of Allergy and Asthma Research (SIAF), University of Zurich, Davos, Switzerland
| | - Hendrik Milting
- Department of Cardiology, University Hospital Bern, Bern, Switzerland
| | - Thomas F Lüscher
- Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland; Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Corinna Brunckhorst
- Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland
| | - Ardan M Saguner
- Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland
| | - Firat Duru
- Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland; Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
| |
Collapse
|
41
|
Leo-Macías A, Liang FX, Delmar M. Ultrastructure of the intercellular space in adult murine ventricle revealed by quantitative tomographic electron microscopy. Cardiovasc Res 2015; 107:442-52. [PMID: 26113266 DOI: 10.1093/cvr/cvv182] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 06/17/2015] [Indexed: 11/13/2022] Open
Abstract
AIMS Progress in tissue preservation (high-pressure freezing), data acquisition (tomographic electron microscopy, TEM), and analysis (image segmentation and quantification) have greatly improved the level of information extracted from ultrastructural images. Here, we combined these methods and developed analytical tools to provide an in-depth morphometric description of the intercalated disc (ID) in adult murine ventricle. As a point of comparison, we characterized the ultrastructure of the ID in mice heterozygous-null for the desmosomal gene plakophilin-2 (PKP2; mice dubbed PKP2-Hz). METHODS AND RESULTS Tomographic EM images of thin sections of adult mouse ventricular tissue were processed by image segmentation analysis. Novel morphometric routines allowed us to generate the first quantitative description of the ID intercellular space based on three-dimensional data. We show that complex invaginations of the cell membrane significantly increased the total ID surface area. In addition, PKP2-Hz samples showed increased average intercellular spacing, ID surface area, and membrane tortuosity, as well as reduced number and length of mechanical junctions compared with control. Finally, we observed membranous structures reminiscent of junctional sarcoplasmic reticulum at the ID, which were significantly more abundant in PKP2-Hz hearts. CONCLUSION We have developed a systematic method to characterize the ultrastructure of the intercellular space in the adult murine ventricle and have provided a quantitative description of the structure of the intercellular membranes and of the intercellular space. We further show that PKP2 deficiency associates with ultrastructural defects. The possible importance of the intercellular space in cardiac behaviour is discussed.
Collapse
Affiliation(s)
- Alejandra Leo-Macías
- Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Feng-Xia Liang
- Microscopy Core, New York University School of Medicine, New York, NY, USA
| | - Mario Delmar
- Leon H Charney Division of Cardiology, New York University School of Medicine, 522 First Avenue, Smilow 805, New York, NY 10016, USA
| |
Collapse
|
42
|
Organization and dynamics of the nonhomologous end-joining machinery during DNA double-strand break repair. Proc Natl Acad Sci U S A 2015; 112:E2575-84. [PMID: 25941401 DOI: 10.1073/pnas.1420115112] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Nonhomologous end-joining (NHEJ) is a major repair pathway for DNA double-strand breaks (DSBs), involving synapsis and ligation of the broken strands. We describe the use of in vivo and in vitro single-molecule methods to define the organization and interaction of NHEJ repair proteins at DSB ends. Super-resolution fluorescence microscopy allowed the precise visualization of XRCC4, XLF, and DNA ligase IV filaments adjacent to DSBs, which bridge the broken chromosome and direct rejoining. We show, by single-molecule FRET analysis of the Ku/XRCC4/XLF/DNA ligase IV NHEJ ligation complex, that end-to-end synapsis involves a dynamic positioning of the two ends relative to one another. Our observations form the basis of a new model for NHEJ that describes the mechanism whereby filament-forming proteins bridge DNA DSBs in vivo. In this scheme, the filaments at either end of the DSB interact dynamically to achieve optimal configuration and end-to-end positioning and ligation.
Collapse
|
43
|
Chen YH, Jones MJK, Yin Y, Crist SB, Colnaghi L, Sims RJ, Rothenberg E, Jallepalli PV, Huang TT. ATR-mediated phosphorylation of FANCI regulates dormant origin firing in response to replication stress. Mol Cell 2015; 58:323-38. [PMID: 25843623 DOI: 10.1016/j.molcel.2015.02.031] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 01/13/2015] [Accepted: 02/25/2015] [Indexed: 12/24/2022]
Abstract
Excess dormant origins bound by the minichromosome maintenance (MCM) replicative helicase complex play a critical role in preventing replication stress, chromosome instability, and tumorigenesis. In response to DNA damage, replicating cells must coordinate DNA repair and dormant origin firing to ensure complete and timely replication of the genome; how cells regulate this process remains elusive. Herein, we identify a member of the Fanconi anemia (FA) DNA repair pathway, FANCI, as a key effector of dormant origin firing in response to replication stress. Cells lacking FANCI have reduced number of origins, increased inter-origin distances, and slowed proliferation rates. Intriguingly, ATR-mediated FANCI phosphorylation inhibits dormant origin firing while promoting replication fork restart/DNA repair. Using super-resolution microscopy, we show that FANCI co-localizes with MCM-bound chromatin in response to replication stress. These data reveal a unique role for FANCI as a modulator of dormant origin firing and link timely genome replication to DNA repair.
Collapse
Affiliation(s)
- Yu-Hung Chen
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Mathew J K Jones
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA; Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Yandong Yin
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Sarah B Crist
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Luca Colnaghi
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Robert J Sims
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Eli Rothenberg
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Prasad V Jallepalli
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Tony T Huang
- Department of Biochemistry & Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA.
| |
Collapse
|
44
|
Exercise Triggers ARVC Phenotype in Mice Expressing a Disease-Causing Mutated Version of Human Plakophilin-2. J Am Coll Cardiol 2015; 65:1438-50. [DOI: 10.1016/j.jacc.2015.01.045] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 11/23/2022]
|
45
|
Franke WW, Rickelt S, Zimbelmann R, Dörflinger Y, Kuhn C, Frey N, Heid H, Rosin-Arbesfeld R. Striatins as plaque molecules of zonulae adhaerentes in simple epithelia, of tessellate junctions in stratified epithelia, of cardiac composite junctions and of various size classes of lateral adherens junctions in cultures of epithelia- and carcinoma-derived cells. Cell Tissue Res 2014; 359:779-97. [PMID: 25501894 PMCID: PMC4341017 DOI: 10.1007/s00441-014-2053-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 11/05/2014] [Indexed: 11/29/2022]
Abstract
Proteins of the striatin family (striatins 1–4; sizes ranging from 90 to 110 kDa on SDS-polyacrylamide gel electrophoresis) are highly homologous in their amino acid sequences but can differ in their cell-type-specific gene expression patterns and biological functions. In various cell types, we have found one, two or three polypeptides of this evolutionarily old and nearly ubiquitous family of proteins known to serve as scaffold proteins for diverse protein complexes. Light and electron microscopic immunolocalization methods have revealed striatins in mammalian cell-cell adherens junctions (AJs). In simple epithelia, we have localized striatins as constitutive components of the plaques of the subapical zonulae adhaerentes of cells, including intestinal, glandular, ductal and urothelial cells and hepatocytes. Striatins colocalize with E-cadherin or E–N-cadherin heterodimers and with the plaque proteins α- and β-catenin, p120 and p0071. In some epithelia and carcinomas and in cultured cells derived therefrom, striatins are also seen in lateral AJs. In stratified epithelia and in corresponding squamous cell carcinomas, striatins can be found in plaques of some forms of tessellate junctions. Moreover, striatins are major plaque proteins of composite junctions (CJs; areae compositae) in the intercalated disks connecting cardiomyocytes, colocalizing with other CJ molecules, including plectin and ankyrin-G. We discuss the “multimodulator” scaffold roles of striatins in the initiation and regulation of the formation of various complex particles and structures. We propose that striatins are included in the diagnostic candidate list of proteins that, in the CJs of human hearts, can occur in mutated forms in the pathogeneses of hereditary cardiomyopathies, as seen in some types of genetically determined heart damage in boxer dogs.
Collapse
Affiliation(s)
- Werner W Franke
- Helmholtz Group for Cell Biology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany,
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Rampazzo A, Calore M, van Hengel J, van Roy F. Intercalated Discs and Arrhythmogenic Cardiomyopathy. ACTA ACUST UNITED AC 2014; 7:930-40. [DOI: 10.1161/circgenetics.114.000645] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Alessandra Rampazzo
- From the Department of Biology, University of Padua, Padua, Italy (A.R., M.C.); Molecular Cell Biology Unit, Inflammation Research Center (IRC), VIB-Ghent University, Ghent, Belgium (J.v.H., F.v.R.); and Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium (J.v.H., F.v.R.)
| | - Martina Calore
- From the Department of Biology, University of Padua, Padua, Italy (A.R., M.C.); Molecular Cell Biology Unit, Inflammation Research Center (IRC), VIB-Ghent University, Ghent, Belgium (J.v.H., F.v.R.); and Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium (J.v.H., F.v.R.)
| | - Jolanda van Hengel
- From the Department of Biology, University of Padua, Padua, Italy (A.R., M.C.); Molecular Cell Biology Unit, Inflammation Research Center (IRC), VIB-Ghent University, Ghent, Belgium (J.v.H., F.v.R.); and Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium (J.v.H., F.v.R.)
| | - Frans van Roy
- From the Department of Biology, University of Padua, Padua, Italy (A.R., M.C.); Molecular Cell Biology Unit, Inflammation Research Center (IRC), VIB-Ghent University, Ghent, Belgium (J.v.H., F.v.R.); and Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium (J.v.H., F.v.R.)
| |
Collapse
|
47
|
Calore M, Lorenzon A, De Bortoli M, Poloni G, Rampazzo A. Arrhythmogenic cardiomyopathy: a disease of intercalated discs. Cell Tissue Res 2014; 360:491-500. [PMID: 25344329 DOI: 10.1007/s00441-014-2015-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 09/18/2014] [Indexed: 01/13/2023]
Abstract
Arrhythmogenic cardiomyopathy (ACM) is an acquired progressive disease having an age-related penetrance and showing clinical manifestations usually during adolescence and young adulthood. It is characterized clinically by a high incidence of severe ventricular tachyarrhythmias and sudden cardiac death and pathologically by degeneration of ventricular cardiomyocytes with replacement by fibro-fatty tissue. Whereas, in the past, the disease was considered to involve only the right ventricle, more recent clinical studies have established that the left ventricle is frequently involved. ACM is an inherited disease in up to 50% of cases, with predominantly an autosomal dominant pattern of transmission, although recessive inheritance has also been described. Since most of the pathogenic mutations have been identified in genes encoding desmosomal proteins, ACM is currently defined as a disease of desmosomes. However, on the basis of the most recent description of the intercalated disc organization and of the identification of a novel ACM gene encoding for an area composita protein, ACM can be considered as a disease of the intercalated disc, rather than only as a desmosomal disease. Despite increasing knowledge of the genetic basis of ACM, we are just beginning to understand early molecular events leading to cardiomyocyte degeneration, fibrosis and fibro-fatty substitution. This review summarizes recent advances in our comprehension of the link between the molecular genetics and pathogenesis of ACM and of the novel role of cardiac intercalated discs.
Collapse
Affiliation(s)
- Martina Calore
- Department of Biology, University of Padua, Via G. Colombo 3, 35131, Padua, Italy
| | | | | | | | | |
Collapse
|
48
|
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.
Collapse
|
49
|
Agullo-Pascual E, Lin X, Leo-Macias A, Zhang M, Liang FX, Li Z, Pfenniger A, Lübkemeier I, Keegan S, Fenyö D, Willecke K, Rothenberg E, Delmar M. Super-resolution imaging reveals that loss of the C-terminus of connexin43 limits microtubule plus-end capture and NaV1.5 localization at the intercalated disc. Cardiovasc Res 2014; 104:371-81. [PMID: 25139742 DOI: 10.1093/cvr/cvu195] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
AIMS It is well known that connexin43 (Cx43) forms gap junctions. We recently showed that Cx43 is also part of a protein-interacting network that regulates excitability. Cardiac-specific truncation of Cx43 C-terminus (mutant 'Cx43D378stop') led to lethal arrhythmias. Cx43D378stop localized to the intercalated disc (ID); cell-cell coupling was normal, but there was significant sodium current (INa) loss. We proposed that the microtubule plus-end is at the crux of the Cx43-INa relation. Yet, specific localization of relevant molecular players was prevented due to the resolution limit of fluorescence microscopy. Here, we use nanoscale imaging to establish: (i) the morphology of clusters formed by the microtubule plus-end tracking protein 'end-binding 1' (EB1), (ii) their position, and that of sodium channel alpha-subunit NaV1.5, relative to N-cadherin-rich sites, and (iii) the role of Cx43 C-terminus on the above-mentioned parameters and on the location-specific function of INa. METHODS AND RESULTS Super-resolution fluorescence localization microscopy in murine adult cardiomyocytes revealed EB1 and NaV1.5 as distinct clusters preferentially localized to N-cadherin-rich sites. Extent of co-localization decreased in Cx43D378stop cells. Macropatch and scanning patch clamp showed reduced INa exclusively at cell end, without changes in unitary conductance. Experiments in Cx43-modified HL1 cells confirmed the relation between Cx43, INa, and microtubules. CONCLUSIONS NaV1.5 and EB1 localization at the cell end is Cx43-dependent. Cx43 is part of a molecular complex that determines capture of the microtubule plus-end at the ID, facilitating cargo delivery. These observations link excitability and electrical coupling through a common molecular mechanism.
Collapse
Affiliation(s)
- Esperanza Agullo-Pascual
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Xianming Lin
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Alejandra Leo-Macias
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Mingliang Zhang
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Feng-Xia Liang
- Office of Collaborative Science Microscopy Core, NYU-SoM, New York, NY, USA
| | - Zhen Li
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Anna Pfenniger
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| | - Indra Lübkemeier
- Life and Medical Sciences Institute, Molecular Genetics, University of Bonn, Bonn, Germany
| | - Sarah Keegan
- Department of Biochemistry and Molecular Pharmacology, NYU-SoM, New York, NY, USA Center for Health Informatics and Bioinformatics, NYU-SoM, New York, NY, USA
| | - David Fenyö
- Department of Biochemistry and Molecular Pharmacology, NYU-SoM, New York, NY, USA Center for Health Informatics and Bioinformatics, NYU-SoM, New York, NY, USA
| | - Klaus Willecke
- Life and Medical Sciences Institute, Molecular Genetics, University of Bonn, Bonn, Germany
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, NYU-SoM, New York, NY, USA
| | - Mario Delmar
- Leon H Charney Division of Cardiology, New York University School of Medicine (NYU-SoM), 522 First Avenue, Smilow 805, New York, NY 10016, USA
| |
Collapse
|
50
|
Patel DM, Green KJ. Desmosomes in the Heart: A Review of Clinical and Mechanistic Analyses. ACTA ACUST UNITED AC 2014; 21:109-28. [DOI: 10.3109/15419061.2014.906533] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|