1
|
Bharathan NK, Mattheyses AL, Kowalczyk AP. The desmosome comes into focus. J Cell Biol 2024; 223:e202404120. [PMID: 39120608 PMCID: PMC11317759 DOI: 10.1083/jcb.202404120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 07/26/2024] [Accepted: 07/29/2024] [Indexed: 08/10/2024] Open
Abstract
The desmosome is a cell-cell adhesive junction that provides integrity and mechanical resistance to tissues through its attachment to the intermediate filament cytoskeleton. Defects in desmosomes cause diseases impacting the heart, epidermis, and other epithelia. In this review, we provide a historical perspective on the discovery of the desmosome and how the evolution of cellular imaging technologies revealed insights into desmosome structure and function. We also discuss recent findings using contemporary imaging approaches that have informed the molecular order, three-dimensional architecture, and associations of desmosomes with organelles such as the endoplasmic reticulum. Finally, we provide an updated model of desmosome molecular organization and speculate upon novel functions of this cell junction as a signaling center for sensing mechanical and other forms of cell stress.
Collapse
Affiliation(s)
- Navaneetha Krishnan Bharathan
- Departments of Dermatology and Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Andrew P Kowalczyk
- Departments of Dermatology and Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA, USA
| |
Collapse
|
2
|
Xie W, Gao S, Yang Y, Li H, Zhou J, Chen M, Yang S, Zhang Y, Zhang L, Meng X, Xie S, Liu M, Li D, Chen Y, Zhou J. CYLD deubiquitinates plakoglobin to promote Cx43 membrane targeting and gap junction assembly in the heart. Cell Rep 2022; 41:111864. [PMID: 36577382 DOI: 10.1016/j.celrep.2022.111864] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 10/06/2022] [Accepted: 11/30/2022] [Indexed: 12/29/2022] Open
Abstract
During heart maturation, gap junctions assemble into hemichannels and polarize to the intercalated disc at cell borders to mediate electrical impulse conduction. However, the molecular mechanism underpinning cardiac gap junction assembly remains elusive. Herein, we demonstrate an important role for the deubiquitinating enzyme cylindromatosis (CYLD) in this process. Depletion of CYLD in mice impairs the formation of cardiac gap junctions, accelerates cardiac fibrosis, and increases heart failure. Mechanistically, CYLD interacts with plakoglobin and removes lysine 63-linked polyubiquitin chains from plakoglobin. The deubiquitination of plakoglobin enhances its interaction with the desmoplakin/end-binding protein 1 complex localized at the microtubule plus end, thereby promoting microtubule-dependent transport of connexin 43 (Cx43), a key component of gap junctions, to the cell membrane. These findings establish CYLD as a critical player in regulating gap junction assembly and have important implications in heart development and diseases.
Collapse
Affiliation(s)
- Wei Xie
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Siqi Gao
- Department of Genetics and Cell Biology, State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yunfan Yang
- Department of Cell Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China.
| | - Hongjie Li
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Junyan Zhou
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Mingzhen Chen
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Song Yang
- Department of Genetics and Cell Biology, State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yijun Zhang
- Department of Genetics and Cell Biology, State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Liang Zhang
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Xiaoqian Meng
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Songbo Xie
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Min Liu
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Dengwen Li
- Department of Genetics and Cell Biology, State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yan Chen
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Jun Zhou
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China; Department of Genetics and Cell Biology, State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin 300071, China.
| |
Collapse
|
3
|
Vite A, Gandjbakhch E, Hery T, Fressart V, Gary F, Simon F, Varnous S, Hidden Lucet F, Charron P, Villard E. Desmoglein-2 mutations in propeptide cleavage-site causes arrhythmogenic right ventricular cardiomyopathy/dysplasia by impairing extracellular 1-dependent desmosomal interactions upon cellular stress. Europace 2021; 22:320-329. [PMID: 31845994 DOI: 10.1093/europace/euz329] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 11/18/2019] [Indexed: 02/04/2023] Open
Abstract
AIMS Desmoglein-2 (DSG2) mutations, which encode a heart-specific cadherin crucial for desmosomal adhesion, are frequent in arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). DSG2 mutations have been associated with higher risk of biventricular involvement. Among DSG2 mutations, mutations of the inhibitory propeptide consensus cleavage-site (Arg-X-Arg/Lys-Arg), are particularly frequent. In the present work, we explored the functional consequences of DSG2 propeptide cleavage site mutations p.Arg49His, p.Arg46Trp, and p.Arg46Gln on localization, adhesive properties, and desmosome incorporation of DSG2. METHODS AND RESULTS We studied the expression of mutant-DSG2 in human heart and in epithelial and cardiac cellular models expressing wild-type or mutant (p.Arg49His, p.Arg46Trp, and p.Arg46Gln) proDSG2-GFP fusion proteins. The consequences of the p.Arg46Trp mutation on DSG2 adhesiveness were studied by surface plasmon resonance. Incorporation of mutant p.Arg46Trp DSG2 into desmosomes was studied under low-calcium culture conditions and cyclic mechanical stress. We demonstrated in human heart and cellular models that all three mutations prevented N-terminal propeptide cleavage, but did not modify intercellular junction targeting. Surface plasmon resonance experiments showed a propeptide-dependent loss of interaction between the cadherin N-terminal extracellular 1 (EC1) domains. Additionally, proDSG2 mutant proteins were abnormally incorporated into desmosomes under low-calcium culture conditions or following mechanical stress. This was accompanied by an epidermal growth factor receptor-dependent internalization of proDSG2, suggesting increased turnover of unprocessed proDSG2. CONCLUSION Our results strongly suggest weakened desmosomal adhesiveness due to abnormal incorporation of uncleaved mutant proDSG2 in cellular stress conditions. These results provide new insights into desmosomal cadherin regulation and ARVC/D pathophysiology, in particular, the potential role of mechanical stress on desmosomal dysfunction.
Collapse
Affiliation(s)
- Alexia Vite
- Sorbonne Université, Faculté de médecine Pitié-Salpêtrière, INSERM U1166, IHU ICAN, F-75013 Paris, France
| | - Estelle Gandjbakhch
- Sorbonne Université, Faculté de médecine Pitié-Salpêtrière, INSERM U1166, IHU ICAN, F-75013 Paris, France.,Département de Cardiologie, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France.,Centre de référence des maladies cardiaques héréditaires, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Tiphaine Hery
- Sorbonne Université, Faculté de médecine Pitié-Salpêtrière, INSERM U1166, IHU ICAN, F-75013 Paris, France
| | - Veronique Fressart
- Service de Biochimie Métabolique, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Unité de Cardiogénétique et Myogénétique, Paris, France
| | - Francoise Gary
- Sorbonne Université, Faculté de médecine Pitié-Salpêtrière, INSERM U1166, IHU ICAN, F-75013 Paris, France
| | - Francoise Simon
- Service de Biochimie Métabolique, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Unité de Cardiogénétique et Myogénétique, Paris, France
| | - Shaida Varnous
- Département de Chirurgie Cardio-thoracique, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | | | - Philippe Charron
- Sorbonne Université, Faculté de médecine Pitié-Salpêtrière, INSERM U1166, IHU ICAN, F-75013 Paris, France.,Département de Cardiologie, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France.,Centre de référence des maladies cardiaques héréditaires, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France.,Département de Génétique, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Eric Villard
- Sorbonne Université, Faculté de médecine Pitié-Salpêtrière, INSERM U1166, IHU ICAN, F-75013 Paris, France
| |
Collapse
|
4
|
Liu YQ, Zou HY, Xie JJ, Fang WK. Paradoxical Roles of Desmosomal Components in Head and Neck Cancer. Biomolecules 2021; 11:914. [PMID: 34203070 PMCID: PMC8234459 DOI: 10.3390/biom11060914] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/14/2021] [Accepted: 06/16/2021] [Indexed: 02/05/2023] Open
Abstract
Desmosomes are intercellular adhesion complexes involved in various aspects of epithelial pathophysiology, including tissue homeostasis, morphogenesis, and disease development. Recent studies have reported that the abnormal expression of various desmosomal components correlates with tumor progression and poor survival. In addition, desmosomes have been shown to act as a signaling platform to regulate the proliferation, invasion, migration, morphogenesis, and apoptosis of cancer cells. The occurrence and progression of head and neck cancer (HNC) is accompanied by abnormal expression of desmosomal components and loss of desmosome structure. However, the role of desmosomal components in the progression of HNC remains controversial. This review aims to provide an overview of recent developments showing the paradoxical roles of desmosomal components in tumor suppression and promotion. It offers valuable insights for HNC diagnosis and therapeutics development.
Collapse
Affiliation(s)
- Yin-Qiao Liu
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China; (Y.-Q.L.); (H.-Y.Z.)
| | - Hai-Ying Zou
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China; (Y.-Q.L.); (H.-Y.Z.)
| | - Jian-Jun Xie
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China; (Y.-Q.L.); (H.-Y.Z.)
- Precision Medicine Research Center, Shantou University Medical College, Shantou 515041, China
| | - Wang-Kai Fang
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China; (Y.-Q.L.); (H.-Y.Z.)
- Precision Medicine Research Center, Shantou University Medical College, Shantou 515041, China
| |
Collapse
|
5
|
Ben-Haim Y, Asimaki A, Behr ER. Brugada syndrome and arrhythmogenic cardiomyopathy: overlapping disorders of the connexome? Europace 2021; 23:653-664. [PMID: 33200179 DOI: 10.1093/europace/euaa277] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/19/2020] [Indexed: 12/19/2022] Open
Abstract
Arrhythmogenic cardiomyopathy (ACM) and Brugada syndrome (BrS) are inherited diseases characterized by an increased risk for arrhythmias and sudden cardiac death. Possible overlap between the two was suggested soon after the description of BrS. Since then, various studies focusing on different aspects have been published pointing to similar findings in the two diseases. More recent findings on the structure of the cardiac cell-cell junctions may unite the pathophysiology of both diseases and give further evidence to the theory that they may in part be variants of the same disease spectrum. In this review, we aim to summarize the studies indicating the pathophysiological, genetic, structural, and electrophysiological overlap between ACM and BrS.
Collapse
Affiliation(s)
- Yael Ben-Haim
- Institute of Molecular and Clinical Sciences, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK
- Cardiology Clinical Academic Group, St. George's University Hospitals NHS Foundation Trust, London, UK
| | - Angeliki Asimaki
- Institute of Molecular and Clinical Sciences, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK
- Cardiology Clinical Academic Group, St. George's University Hospitals NHS Foundation Trust, London, UK
| | - Elijah R Behr
- Institute of Molecular and Clinical Sciences, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK
- Cardiology Clinical Academic Group, St. George's University Hospitals NHS Foundation Trust, London, UK
| |
Collapse
|
6
|
Yeruva S, Kempf E, Egu DT, Flaswinkel H, Kugelmann D, Waschke J. Adrenergic Signaling-Induced Ultrastructural Strengthening of Intercalated Discs via Plakoglobin Is Crucial for Positive Adhesiotropy in Murine Cardiomyocytes. Front Physiol 2020; 11:430. [PMID: 32508670 PMCID: PMC7253624 DOI: 10.3389/fphys.2020.00430] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/08/2020] [Indexed: 11/26/2022] Open
Abstract
Intercalated discs (ICDs), which connect adjacent cardiomyocytes, are composed of desmosomes, adherens junctions (AJs) and gap junctions (GJs). Previous data demonstrated that adrenergic signaling enhances cardiac myocyte cohesion, referred to as positive adhesiotropy, via PKA-mediated phosphorylation of plakoglobin (PG). However, it was unclear whether positive adhesiotropy caused ultrastructural modifications of ICDs. Therefore, we further investigated the role of PG in adrenergic signaling-mediated ultrastructural changes in the ICD of cardiomyocytes. Quantitative transmission electron microscopy (TEM) analysis of ICD demonstrated that cAMP elevation caused significant elongation of area composita and thickening of the ICD plaque, paralleled by enhanced cardiomyocyte cohesion, in WT but not PG-deficient cardiomyocytes. STED microscopy analysis supported that cAMP elevation ex vivo enhanced overlap of desmoglein-2 (Dsg2) and N-cadherin (N-cad) staining in ICDs of WT but not PG-deficient cardiomyocytes. For dynamic analyses, we utilized HL-1 cardiomyocytes, in which cAMP elevation induced translocation of Dsg2 and PG but not of N-cad to cell junctions. Nevertheless, depletion of N-cad but not of Dsg2 resulted in a decrease in basal cell cohesion whereas positive adhesiotropy was abrogated in monolayers depleted for either Dsg2 or N-cad. In the WT mice, ultrastrutural changes observed after cAMP elevation were paralleled by phosphorylation of PG at serine 665. Our data demonstrate that in murine hearts adrenergic signaling enhanced N-cad and Dsg2 in the ICD paralleled by ultrastrutural strengthening of ICDs and that effects induced by positive adhesiotropy were strictly dependent on Pg.
Collapse
Affiliation(s)
- Sunil Yeruva
- Institute of Anatomy and Cell Biology, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Ellen Kempf
- Institute of Anatomy and Cell Biology, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Desalegn Tadesse Egu
- Institute of Anatomy and Cell Biology, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | | | - Daniela Kugelmann
- Institute of Anatomy and Cell Biology, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Jens Waschke
- Institute of Anatomy and Cell Biology, Faculty of Medicine, Ludwig-Maximilians-Universität Munich, Munich, Germany
| |
Collapse
|
7
|
Abreu-Velez AM, Upegui-Zapata YA, Valencia-Yepes CA, Upegui-Quiceno E, Jiménez-Echavarría AM, Niño-Pulido CD, Smoller BR, Howard MS. Involvement of the Areae Compositae of the Heart in Endemic Pemphigus Foliaceus. Dermatol Pract Concept 2019; 9:181-186. [PMID: 31384490 DOI: 10.5826/dpc.0903a02] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2019] [Indexed: 12/11/2022] Open
Abstract
Background A new variant of endemic pemphigus foliaceus in El Bagre (El Bagre-EPF), Colombia, South America, shares features with Senear-Usher syndrome and occurs in an endemic fashion. Patients affected by El Bagre-EPF have heterogeneous antigenic reactivity not only to the skin but to other organs, including the heart. Here we test for autoantibodies to the areae compositae of the heart (structure consisting of typical desmosomal amalgamated fascia adherens molecules) and evaluate any possible clinical correlation. Methods A case-control study comparing 45 patients and 45 controls from the endemic area, matched by demographics including age, gender, weight, work activities, and comorbidities, was performed. Direct and indirect immunofluorescence, immunohistochemistry, confocal microscopic studies, and echocardiogram studies were completed. Results The main clinical abnormally seen in the El Bagre-EPF patients was left ventricular hypertrophy in 15/45 patients, compared with no such findings in the control population (P < 0.1). Seventy percent of El Bagre-EPF patients and none of the controls displayed polyclonal autoreactivity using different immunoglobulins and complement to the areae compositae of the heart using different methods and antibodies (P < 0.1). Conclusions Patients affected by El Bagre-EPF demonstrated autoantibodies to the areae compositae of the heart. This finding was associated with left ventricular hypertrophic cardiomyopathy. The areae compositae may play a role in cell junction tension and the El Bagre-EPF patients' autoantibodies possibly disrupting these junctions and thereby contributing to the left ventricular hypertrophy.
Collapse
Affiliation(s)
| | - Yulieth A Upegui-Zapata
- PECET Group, Pharmaceutical Sciences, Medical Research Institute, School of Medicine, University of Antioquia, Medellín, Colombia
| | | | | | | | | | - Bruce R Smoller
- Departments of Pathology and Laboratory Medicine & Dermatology, University of Rochester Medical Center, School of Medicine and Dentistry, Rochester, NY, USA
| | | |
Collapse
|
8
|
Li Y, Merkel CD, Zeng X, Heier JA, Cantrell PS, Sun M, Stolz DB, Watkins SC, Yates NA, Kwiatkowski AV. The N-cadherin interactome in primary cardiomyocytes as defined using quantitative proximity proteomics. J Cell Sci 2019; 132:jcs.221606. [PMID: 30630894 PMCID: PMC6382013 DOI: 10.1242/jcs.221606] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 12/24/2018] [Indexed: 12/11/2022] Open
Abstract
The junctional complexes that couple cardiomyocytes must transmit the mechanical forces of contraction while maintaining adhesive homeostasis. The adherens junction (AJ) connects the actomyosin networks of neighboring cardiomyocytes and is required for proper heart function. Yet little is known about the molecular composition of the cardiomyocyte AJ or how it is organized to function under mechanical load. Here, we define the architecture, dynamics and proteome of the cardiomyocyte AJ. Mouse neonatal cardiomyocytes assemble stable AJs along intercellular contacts with organizational and structural hallmarks similar to mature contacts. We combine quantitative mass spectrometry with proximity labeling to identify the N-cadherin (CDH2) interactome. We define over 350 proteins in this interactome, nearly 200 of which are unique to CDH2 and not part of the E-cadherin (CDH1) interactome. CDH2-specific interactors comprise primarily adaptor and adhesion proteins that promote junction specialization. Our results provide novel insight into the cardiomyocyte AJ and offer a proteomic atlas for defining the molecular complexes that regulate cardiomyocyte intercellular adhesion. This article has an associated First Person interview with the first authors of the paper.
Collapse
Affiliation(s)
- Yang Li
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Chelsea D Merkel
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Xuemei Zeng
- Biomedical Mass Spectrometry Center, University of Pittsburgh Schools of the Health Sciences, Pittsburgh, PA 15261, USA
| | - Jonathon A Heier
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Pamela S Cantrell
- Biomedical Mass Spectrometry Center, University of Pittsburgh Schools of the Health Sciences, Pittsburgh, PA 15261, USA
| | - Mai Sun
- Biomedical Mass Spectrometry Center, University of Pittsburgh Schools of the Health Sciences, Pittsburgh, PA 15261, USA
| | - Donna B Stolz
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Simon C Watkins
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Nathan A Yates
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.,Biomedical Mass Spectrometry Center, University of Pittsburgh Schools of the Health Sciences, Pittsburgh, PA 15261, USA.,University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA 15232, USA
| | - Adam V Kwiatkowski
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| |
Collapse
|
9
|
Manring HR, Dorn LE, Ex-Willey A, Accornero F, Ackermann MA. At the heart of inter- and intracellular signaling: the intercalated disc. Biophys Rev 2018; 10:961-971. [PMID: 29876873 DOI: 10.1007/s12551-018-0430-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 05/22/2018] [Indexed: 12/17/2022] Open
Abstract
Proper cardiac function requires the synchronous mechanical and electrical coupling of individual cardiomyocytes. The intercalated disc (ID) mediates coupling of neighboring myocytes through intercellular signaling. Intercellular communication is highly regulated via intracellular signaling, and signaling pathways originating from the ID control cardiomyocyte remodeling and function. Herein, we present an overview of the inter- and intracellular signaling that occurs at and originates from the intercalated disc in normal physiology and pathophysiology. This review highlights the importance of the intercalated disc as an integrator of signaling events regulating homeostasis and stress responses in the heart and the center of several pathophysiological processes mediating the development of cardiomyopathies.
Collapse
Affiliation(s)
- Heather R Manring
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Lisa E Dorn
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Aidan Ex-Willey
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Federica Accornero
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA.
| | - Maegen A Ackermann
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA.
| |
Collapse
|
10
|
Liu N, Zheng M, Li S, Bai H, Liu Z, Hou CH, Zhang S, Pu J. Genetic Mechanisms Contribute to the Development of Heart Failure in Patients with Atrioventricular Block and Right Ventricular Apical Pacing. Sci Rep 2017; 7:10676. [PMID: 28878402 PMCID: PMC5587648 DOI: 10.1038/s41598-017-11211-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 08/21/2017] [Indexed: 12/22/2022] Open
Abstract
Right ventricular apical (RVA) pacing can lead to progressive left ventricular dysfunction and heart failure (HF), even in patients with normal cardiac structure and function. Our study conducted candidate gene screening and lentivirus transfected neonatal rat cardiomyocytes (NRCMs) to explore the genetic and pathogenic mechanisms of RVA pacing induced cardiomyopathy in third degree atrioventricular block (III AVB) patients. We followed 887 III AVB patients with baseline normal cardiac function and RVA pacing. After a median follow-up of 2.5 years, 10 patients (four males, mean age 47.6 ± 10.0 years) were diagnosed with RVA pacing induced HF with left ventricular ejection fraction (LVEF) reducing dramatically to 37.8 ± 7.1% (P < 0.05). Candidate genes sequencing found cardiomyopathy associated genetic variations in all ten HF patients and six SCN5A variations in 6 of 20 control patients. Transfected NRCMs of Lamin A/C mutations (R216C and L379F) disrupted Lamin A/C location on nucleus membrane and finally resulted in increased apoptotic rate after serum starvation. In conclusion, cardiomyopathy associated genetic variations play an essential role in occurrence of newly onset HF in the III AVB patients with RVA pacing. RVA pacing, serving as extra stimulator, might accelerate the deterioration of cardiac structure and function.
Collapse
Affiliation(s)
- Nana Liu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People's Republic of China
| | - Min Zheng
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People's Republic of China
- Department of cardiovascular diseases, Dongfang Hospital Affiliated to Tongji University, Shanghai, 200120, People's Republic of China
| | - Shijie Li
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People's Republic of China
| | - Hui Bai
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People's Republic of China
| | - Zhouying Liu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People's Republic of China
| | - Cui Hong Hou
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People's Republic of China
| | - Shu Zhang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People's Republic of China
| | - Jielin Pu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, People's Republic of China.
- Department of cardiovascular diseases, Dongfang Hospital Affiliated to Tongji University, Shanghai, 200120, People's Republic of China.
| |
Collapse
|
11
|
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]
|
12
|
Xu H, Li J, Zhao Y, Liu D. TNFα-induced downregulation of microRNA-186 contributes to apoptosis in rat primary cardiomyocytes. Immunobiology 2017; 222:778-784. [PMID: 28233577 DOI: 10.1016/j.imbio.2017.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/14/2017] [Accepted: 02/14/2017] [Indexed: 12/21/2022]
Abstract
Progressive loss of cardiac cardiomyocytes is involved in pathogenesis of heart failure. Inflammation is considered as a major risk factor that triggers cardiomyocytes apoptosis or induces cellular damage. Proinflammatory cytokines such as TNFα can directly activate cell apoptosis or promote oxidant production that damages cellular structure eventually. We investigated TNFα mediated apoptosis in cultured rat primary cardiomyocytes. Annexin V/PI staining and apoptosis biomarker expression were used to examine cardiomyocytes cell apoptosis response. We also identified key microRNA that plays a regulatory role in this pathway with genetic and biochemical approaches. Apoptosis Inducing Factor (AIF) expression was found to be upregulated with 10μg/ml or 50μg/ml TNFα stimulation for 24h, which was associated with apoptotic index. Subsequently, miR-186 was identified as direct regulator of AIF in TNFα mediated cardiomyocytes apoptosis from microRNA expression profiling. miR-186 level was downregulated with TNFα treatment that was correlated with AIF induction. Last, in the rescue experiment, miR-186 mimic protected cardiomyocytes against TNFα mediated apoptosis. Collectively, the results suggest TNFα-induced AIF upregulation contributes to apoptosis in rat primary cardiomyocytes through regulating miR-186 expression, which implies miR-186 could be a potential therapeutic target for preventing inflammation associated cardiac damage.
Collapse
Affiliation(s)
- Hua Xu
- Department of Cardiology, Daqing Oil Field General Hospital, NO. 9 Saertu District, Daqing City, 163000, Heilongjiang Province, China.
| | - Jingyao Li
- Department of Cardiology, Daqing Oil Field General Hospital, NO. 9 Saertu District, Daqing City, 163000, Heilongjiang Province, China
| | - Yue Zhao
- Department of Cardiology, Daqing Oil Field General Hospital, NO. 9 Saertu District, Daqing City, 163000, Heilongjiang Province, China
| | - Dayi Liu
- Department of Cardiology, Daqing Oil Field General Hospital, NO. 9 Saertu District, Daqing City, 163000, Heilongjiang Province, China
| |
Collapse
|
13
|
Ren XM, Zuo GF, Wu W, Luo J, Ye P, Chen SL, Hu ZY. Atorvastatin Alleviates Experimental Diabetic Cardiomyopathy by Regulating the GSK-3β-PP2Ac-NF-κB Signaling Axis. PLoS One 2016; 11:e0166740. [PMID: 27851811 PMCID: PMC5112957 DOI: 10.1371/journal.pone.0166740] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 11/02/2016] [Indexed: 01/17/2023] Open
Abstract
Recent studies reported that atorvastatin (ATOR) alleviated progression of experimental diabetic cardiomyopathy (DCM), possibly by protecting against apoptosis. However, the underlying mechanisms of this protective effect remain unclear. Therefore, our study investigated the role of the glycogen synthase kinase (GSK)-3β-protein phosphatase 2A(PP2A)-NF-κB signaling pathway in the anti-apoptotic and cardioprotective effects of ATOR on cardiomyocytes cultured in high glucose (HG) and in DCM. Our results showed that, in HG-cultured cardiomyocytes, phosphorylation of GSK-3β was decreased, while that of the PP2A catalytic subunit C (PP2Ac) and IKK/IкBα was increased, followed by NF-кB nuclear translocation and apoptosis. IKK/IкBα phosphorylation and NF-кB nuclear translocation were also increased by treatment of cells with okadaic acid (OA), a selective PP2A inhibitor, or by silencing PP2Ac expression. The opposite results were obtained by silencing GSK-3β expression, which resulted in PP2Ac activation. Furthermore, IKK/IкBα phosphorylation and NF-кB nuclear translocation were markedly inhibited and apoptosis attenuated in cells treated with ATOR. These effects occurred through inactivation of GSK-3β and subsequent activation of PP2Ac. They were abolished by treatment of cells with OA or PP2Ac siRNA. In mice with type 1 diabetes mellitus, treatment with ATOR, at 10 mg-kg−1-d−1, significantly suppressed GSK-3β activation, IKK/IкBα phosphorylation, NF-кB nuclear translocation and caspase-3 activation, while also activating PP2Ac. Finally, improvements in histological abnormalities, fibrosis, apoptosis and cardiac dysfunction were observed in diabetic mice treated with ATOR. These findings demonstrated that ATOR protected against HG-induced apoptosis in cardiomyocytes and alleviated experimental DCM by regulating the GSK-3β-PP2A-NF-κB signaling pathway.
Collapse
Affiliation(s)
- Xiao-min Ren
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Qinhuai, Nanjing 210006, P.R. China
| | - Guang-feng Zuo
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Qinhuai, Nanjing 210006, P.R. China
| | - Wen Wu
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Qinhuai, Nanjing 210006, P.R. China
| | - Jie Luo
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Qinhuai, Nanjing 210006, P.R. China
| | - Peng Ye
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Qinhuai, Nanjing 210006, P.R. China
| | - Shao-liang Chen
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Qinhuai, Nanjing 210006, P.R. China
- * E-mail: (SLC); (ZYH)
| | - Zuo-ying Hu
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Qinhuai, Nanjing 210006, P.R. China
- * E-mail: (SLC); (ZYH)
| |
Collapse
|
14
|
Roberts BJ, Svoboda RA, Overmiller AM, Lewis JD, Kowalczyk AP, Mahoney MG, Johnson KR, Wahl JK. Palmitoylation of Desmoglein 2 Is a Regulator of Assembly Dynamics and Protein Turnover. J Biol Chem 2016; 291:24857-24865. [PMID: 27703000 DOI: 10.1074/jbc.m116.739458] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/08/2016] [Indexed: 01/09/2023] Open
Abstract
Desmosomes are prominent adhesive junctions present between many epithelial cells as well as cardiomyocytes. The mechanisms controlling desmosome assembly and remodeling in epithelial and cardiac tissue are poorly understood. We recently identified protein palmitoylation as a mechanism regulating desmosome dynamics. In this study, we have focused on the palmitoylation of the desmosomal cadherin desmoglein-2 (Dsg2) and characterized the role that palmitoylation of Dsg2 plays in its localization and stability in cultured cells. We identified two cysteine residues in the juxtamembrane (intracellular anchor) domain of Dsg2 that, when mutated, eliminate its palmitoylation. These cysteine residues are conserved in all four desmoglein family members. Although mutant Dsg2 localizes to endogenous desmosomes, there is a significant delay in its incorporation into junctions, and the mutant is also present in a cytoplasmic pool. Triton X-100 solubility assays demonstrate that mutant Dsg2 is more soluble than wild-type protein. Interestingly, trafficking of the mutant Dsg2 to the cell surface was delayed, and a pool of the non-palmitoylated Dsg2 co-localized with lysosomal markers. Taken together, these data suggest that palmitoylation of Dsg2 regulates protein transport to the plasma membrane. Modulation of the palmitoylation status of desmosomal cadherins can affect desmosome dynamics.
Collapse
Affiliation(s)
- Brett J Roberts
- From the Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska 68583
| | - Robert A Svoboda
- From the Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska 68583
| | - Andrew M Overmiller
- the Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, and
| | - Joshua D Lewis
- the Departments of Cell Biology and Dermatology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Andrew P Kowalczyk
- the Departments of Cell Biology and Dermatology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - My G Mahoney
- the Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, and
| | - Keith R Johnson
- From the Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska 68583.,the Eppley Institute for Research in Cancer and Allied Diseases, Omaha, Nebraska 68198
| | - James K Wahl
- From the Department of Oral Biology, College of Dentistry, University of Nebraska Medical Center, Lincoln, Nebraska 68583,
| |
Collapse
|
15
|
Dubash AD, Kam CY, Aguado BA, Patel DM, Delmar M, Shea LD, Green KJ. Plakophilin-2 loss promotes TGF-β1/p38 MAPK-dependent fibrotic gene expression in cardiomyocytes. J Cell Biol 2016; 212:425-38. [PMID: 26858265 PMCID: PMC4754716 DOI: 10.1083/jcb.201507018] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 01/08/2016] [Indexed: 01/07/2023] Open
Abstract
Members of the desmosome protein family are integral components of the cardiac area composita, a mixed junctional complex responsible for electromechanical coupling between cardiomyocytes. In this study, we provide evidence that loss of the desmosomal armadillo protein Plakophilin-2 (PKP2) in cardiomyocytes elevates transforming growth factor β1 (TGF-β1) and p38 mitogen-activated protein kinase (MAPK) signaling, which together coordinate a transcriptional program that results in increased expression of profibrotic genes. Importantly, we demonstrate that expression of Desmoplakin (DP) is lost upon PKP2 knockdown and that restoration of DP expression rescues the activation of this TGF-β1/p38 MAPK transcriptional cascade. Tissues from PKP2 heterozygous and DP conditional knockout mouse models also exhibit elevated TGF-β1/p38 MAPK signaling and induction of fibrotic gene expression in vivo. These data therefore identify PKP2 and DP as central players in coordination of desmosome-dependent TGF-β1/p38 MAPK signaling in cardiomyocytes, pathways known to play a role in different types of cardiac disease, such as arrhythmogenic or hypertrophic cardiomyopathy.
Collapse
Affiliation(s)
- Adi D Dubash
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 Department of Biology, Furman University, Greenville SC 29613
| | - Chen Y Kam
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Brian A Aguado
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208 Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago IL 60611
| | - Dipal M Patel
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Mario Delmar
- New York University School of Medicine, New York, NY 10016
| | - Lonnie D Shea
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208 Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105
| | - Kathleen J Green
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| |
Collapse
|
16
|
Lübkemeier I, Bosen F, Kim JS, Sasse P, Malan D, Fleischmann BK, Willecke K. Human Connexin43E42K Mutation From a Sudden Infant Death Victim Leads to Impaired Ventricular Activation and Neonatal Death in Mice. ACTA ACUST UNITED AC 2015; 8:21-9. [DOI: 10.1161/circgenetics.114.000793] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Sudden infant death syndrome (SIDS) describes the sudden, unexplained death of a baby during its first year of age and is the third leading cause of infant mortality. It is assumed that ≤20% of all SIDS cases are because of cardiac arrhythmias resulting from mutations in ion channel proteins. Besides ion channels also cardiac gap junction channels are important for proper conduction of cardiac electric activation. In the mammalian heart Connexin43 (Cx43) is the major gap junction protein expressed in ventricular cardiomyocytes. Recently, a novel Connexin43 loss-of-function mutation (Cx43E42K) was identified in a 2-month-old SIDS victim.
Methods and Results—
We have generated Cx43E42K-expressing mice as a model for SIDS. Heterozygous cardiac-restricted Cx43E42K-mutated mice die neonatally without major cardiac morphological defects. Electrocardiographic recordings of embryonic Cx43+/E42K mice reveal severely disturbed ventricular activation, whereas immunohistochemical analyses show normal localization and expression patterns of gap junctional Connexin43 protein in the Cx43E42K-mutated newborn mouse heart.
Conclusions—
Because we did not find heterogeneous gap junction loss in Cx43E42K mouse hearts, we conclude that the Cx43E42K gap junction channel creates an arrhythmogenic substrate leading to lethal ventricular arrhythmias. The strong cardiac phenotype of Cx43E42K expressing mice supports the association between the human Cx43E42K mutation and SIDS and indicates that Connexin43 mutations should be considered in future studies when SIDS cases are to be molecularly explained.
Collapse
Affiliation(s)
- Indra Lübkemeier
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Felicitas Bosen
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Jung-Sun Kim
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Philipp Sasse
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Daniela Malan
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Bernd K. Fleischmann
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| | - Klaus Willecke
- From the Life and Medical Sciences (LIMES) Institute, Molecular Genetics (I.L., F.B., K.W.) and Institute of Physiology I, Life and Brain Center (P.S., D.M., B.K.F.), University of Bonn, Bonn, Germany; and Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (J.-S.K.)
| |
Collapse
|
17
|
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]
|
18
|
Nitoiu D, Etheridge SL, Kelsell DP. Insights into Desmosome Biology from Inherited Human Skin Disease and Cardiocutaneous Syndromes. ACTA ACUST UNITED AC 2014; 21:129-40. [DOI: 10.3109/15419061.2014.908854] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
19
|
Du Y, Zhu H, Li D, Wang L, Zhang L, Luo Y, Pan D, Huang M. Lentiviral-mediated overexpression of Akt1 reduces anoxia-reoxygenation injury in cardiomyocytes. Cell Biol Int 2014; 38:488-96. [PMID: 24375547 DOI: 10.1002/cbin.10234] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 11/13/2013] [Indexed: 12/29/2022]
Abstract
Activated PI3K/Akt signalling exerts a protective effect after myocardial ischemia by phosphorylating various substrates; however, the precise mechanism by which this occurs remains to be elucidated. We have constructed the recombinant lentiviral vector pLVX-Akt1-EGFP- 3FLAG (LV-Akt1) to determine the efficiency of LV-Akt1 infection, explore the protective role of Akt1, and investigate the possible mechanism by which Akt1 signalling acts during anoxia/reoxygenation (A/R) of cardiomyocytes in primary culture. Akt1 gene transfection increased cardiomyocyte pulsation, reduced cell mortality, and decreased the concentration of lactate dehydrogenase (LDH) in myocardial cells supernatants. Akt1 transfection increased the levels of intracellular p-Akt, enhanced the expression of the anti-apoptosis protein Bcl-2, and reduced that of the apoptosis protein Bax (thereby increasing the Bcl-2/Bax ratio), and caused some increase in hypoxia-inducible factor1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression after A/R. The protective role of Akt1 was partly suppressed by adding a phosphoinositide 3-kinase/Akt inhibitor (LY294002). In conclusion, LV-Akt1 was successfully constructed and neonatal rat cardiomyocytes were transfected efficiently. Akt1 overexpression significantly reduced A/R injury in cardiomyocytes, and this could be related to its effects on various targets of the PI3K/Akt signalling pathway, such as Bcl-2, Bax, HIF-1α and VEGF.
Collapse
Affiliation(s)
- Yanyan Du
- Institute of Cardiovascular Disease Research, Xuzhou Medical College, No. 84 West Huaihai Road, Xuzhou, Jiangsu, 221002, P.R. China
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Zhou J, Shu Y, Lü SH, Li JJ, Sun HY, Tang RY, Duan CM, Wang Y, Lin QX, Mou YC, Li X, Wang CY. The spatiotemporal development of intercalated disk in three-dimensional engineered heart tissues based on collagen/matrigel matrix. PLoS One 2013; 8:e81420. [PMID: 24260578 PMCID: PMC3829928 DOI: 10.1371/journal.pone.0081420] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 10/12/2013] [Indexed: 01/09/2023] Open
Abstract
Intercalated disk (ID), which electromechanically couples cardiomyocytes into a functional syncitium, is closely related to normal morphology and function of engineered heart tissues (EHTs), but the development mode of ID in the three-dimensional (3D) EHTs is still unclear. In this study, we focused on the spatiotemporal development of the ID in the EHTs constructed by mixing neonatal rat cardiomyocytes with collagen/Matrigel, and investigated the effect of 3D microenvironment provided by collagen/Matrigel matrix on the formation of ID. By histological and immmunofluorescent staining, the spatiotemporal distribution of ID-related junctions was detected. Furthermore, the ultra-structures of the ID in different developmental stages were observed under transmission electron microscope. In addition, the expression of the related proteins was quantitatively analyzed. The results indicate that accompanying the re-organization of cardiomyocytes in collagen/Matrigel matrix, the proteins of adherens junctions, desmosomes and gap junctions redistributed from diffused distribution to intercellular regions to form an integrated ID. The adherens junction and desmosome which are related with mechanical connection appeared earlier than gap junction which is essential for electrochemical coupling. These findings suggest that the 3D microenvironment based on collagen/Matrigel matrix could support the ordered assembly of the ID in EHTs and have implications for comprehending the ordered and coordinated development of ID during the functional organization of EHTs.
Collapse
Affiliation(s)
- Jin Zhou
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
| | - Yao Shu
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
| | - Shuang-Hong Lü
- Laboratory of Oncology, Affiliated Hospital of Academy of Military Medical Sciences, Beijing, China
| | - Jun-Jie Li
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
| | - Hong-Yu Sun
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
| | - Rong-Yu Tang
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
| | - Cui-Mi Duan
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
| | - Yan Wang
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
| | - Qiu-Xia Lin
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
| | - Yong-Chao Mou
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
| | - Xia Li
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
| | - Chang-Yong Wang
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China
- * E-mail:
| |
Collapse
|
21
|
Transmembrane protein PERP is a component of tessellate junctions and of other junctional and non-junctional plasma membrane regions in diverse epithelial and epithelium-derived cells. Cell Tissue Res 2013; 353:99-115. [PMID: 23689684 PMCID: PMC3691483 DOI: 10.1007/s00441-013-1645-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 04/22/2013] [Indexed: 12/16/2022]
Abstract
Protein PERP (p53 apoptosis effector related to PMP-22) is a small (21.4 kDa) transmembrane polypeptide with an amino acid sequence indicative of a tetraspanin character. It is enriched in the plasma membrane and apparently contributes to cell-cell contacts. Hitherto, it has been reported to be exclusively a component of desmosomes of some stratified epithelia. However, by using a series of newly generated mono- and polyclonal antibodies, we show that protein PERP is not only present in all kinds of stratified epithelia but also occurs in simple, columnar, complex and transitional epithelia, in various types of squamous metaplasia and epithelium-derived tumors, in diverse epithelium-derived cell cultures and in myocardial tissue. Immunofluorescence and immunoelectron microscopy allow us to localize PERP predominantly in small intradesmosomal locations and in variously sized, junction-like peri- and interdesmosomal regions ("tessellate junctions"), mostly in mosaic or amalgamated combinations with other molecules believed, to date, to be exclusive components of tight and adherens junctions. In the heart, PERP is a major component of the composite junctions of the intercalated disks connecting cardiomyocytes. Finally, protein PERP is a cobblestone-like general component of special plasma membrane regions such as the bile canaliculi of liver and subapical-to-lateral zones of diverse columnar epithelia and upper urothelial cell layers. We discuss possible organizational and architectonic functions of protein PERP and its potential value as an immunohistochemical diagnostic marker.
Collapse
|
22
|
Deletion of the last five C-terminal amino acid residues of connexin43 leads to lethal ventricular arrhythmias in mice without affecting coupling via gap junction channels. Basic Res Cardiol 2013; 108:348. [PMID: 23558439 DOI: 10.1007/s00395-013-0348-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 03/08/2013] [Accepted: 03/25/2013] [Indexed: 10/27/2022]
Abstract
The cardiac intercalated disc harbors mechanical and electrical junctions as well as ion channel complexes mediating propagation of electrical impulses. Cardiac connexin43 (Cx43) co-localizes and interacts with several of the proteins located at intercalated discs in the ventricular myocardium. We have generated conditional Cx43D378stop mice lacking the last five C-terminal amino acid residues, representing a binding motif for zonula occludens protein-1 (ZO-1), and investigated the functional consequences of this mutation on cardiac physiology and morphology. Newborn and adult homozygous Cx43D378stop mice displayed markedly impaired and heterogeneous cardiac electrical activation properties and died from severe ventricular arrhythmias. Cx43 and ZO-1 were co-localized at intercalated discs in Cx43D378stop hearts, and the Cx43D378stop gap junction channels showed normal coupling properties. Patch clamp analyses of isolated adult Cx43D378stop cardiomyocytes revealed a significant decrease in sodium and potassium current densities. Furthermore, we also observed a significant loss of Nav1.5 protein from intercalated discs in Cx43D378stop hearts. The phenotypic lethality of the Cx43D378stop mutation was very similar to the one previously reported for adult Cx43 deficient (Cx43KO) mice. Yet, in contrast to Cx43KO mice, the Cx43 gap junction channel was still functional in the Cx43D378stop mutant. We conclude that the lethality of Cx43D378stop mice is independent of the loss of gap junctional intercellular communication, but most likely results from impaired cardiac sodium and potassium currents. The Cx43D378stop mice reveal for the first time that Cx43 dependent arrhythmias can develop by mechanisms other than impairment of gap junction channel function.
Collapse
|
23
|
Pieperhoff S, Rickelt S, Heid H, Claycomb WC, Zimbelmann R, Kuhn C, Winter-Simanowski S, Kuhn C, Frey N, Franke WW. The plaque protein myozap identified as a novel major component of adhering junctions in endothelia of the blood and the lymph vascular systems. J Cell Mol Med 2012; 16:1709-19. [PMID: 21992629 PMCID: PMC3822684 DOI: 10.1111/j.1582-4934.2011.01463.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 09/07/2011] [Indexed: 01/22/2023] Open
Abstract
Recently the protein myozap, a 54-kD polypeptide which is not a member of any of the known cytoskeletal and junctional protein multigene families, has been identified as a constituent of the plaques of the composite junctions in the intercalated disks connecting the cardiomyocytes of mammalian hearts. Using a set of novel, highly sensitive and specific antibodies we now report that myozap is also a major constituent of the cytoplasmic plaques of the adherens junctions (AJs) connecting the endothelial cells of the mammalian blood and lymph vascular systems, including the desmoplakin-containing complexus adhaerentes of the virgultar cells of lymph node sinus. In light and electron microscopic immunolocalization experiments we show that myozap colocalizes with several proteins of desmosomal plaques as well as with AJ-specific transmembrane molecules, including VE-cadherin. In biochemical analyses, rigorous immunoprecipitation experiments have revealed N-cadherin, desmoplakin, desmoglein-2, plakophilin-2, plakoglobin and plectin as very stably bound complex partners. We conclude that myozap is a general component of cell-cell junctions not only in the myocardium but also in diverse endothelia of the blood and lymph vascular systems of adult mammals, suggesting that this protein not only serves a specific role in the heart but also a broader set of functions in the vessel systems. We also propose to use myozap as an endothelial cell type marker in diagnoses.
Collapse
Affiliation(s)
- Sebastian Pieperhoff
- Helmholtz Group Cell Biology, German Cancer Research Center (DKFZ)Heidelberg, Germany
- Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of EdinburghEdinburgh, Scotland, United Kingdom
- Department of Zoology and Faculty of Land and Food Systems, University of British ColumbiaVancouver, Canada
| | - Steffen Rickelt
- Helmholtz Group Cell Biology, German Cancer Research Center (DKFZ)Heidelberg, Germany
- Progen Biotechnik GmbH, HeidelbergGermany
| | - Hans Heid
- Helmholtz Group Cell Biology, German Cancer Research Center (DKFZ)Heidelberg, Germany
| | | | - Ralf Zimbelmann
- Helmholtz Group Cell Biology, German Cancer Research Center (DKFZ)Heidelberg, Germany
| | - Caecilia Kuhn
- Helmholtz Group Cell Biology, German Cancer Research Center (DKFZ)Heidelberg, Germany
- Progen Biotechnik GmbH, HeidelbergGermany
| | | | - Christian Kuhn
- Internal Medicine and Cardiology, Department of Cardiology and Angiology, University Hospital, Schleswig-HolsteinCampus Kiel, Kiel, Germany
| | - Norbert Frey
- Internal Medicine and Cardiology, Department of Cardiology and Angiology, University Hospital, Schleswig-HolsteinCampus Kiel, Kiel, Germany
| | - Werner W Franke
- Helmholtz Group Cell Biology, German Cancer Research Center (DKFZ)Heidelberg, Germany
- Progen Biotechnik GmbH, HeidelbergGermany
| |
Collapse
|
24
|
Mesenchymal stromal cells (MSCs): science and f(r)iction. J Mol Med (Berl) 2012; 90:773-82. [DOI: 10.1007/s00109-012-0915-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 05/02/2012] [Accepted: 05/09/2012] [Indexed: 12/22/2022]
|
25
|
Brooke MA, Nitoiu D, Kelsell DP. Cell-cell connectivity: desmosomes and disease. J Pathol 2011; 226:158-71. [PMID: 21989576 DOI: 10.1002/path.3027] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 10/03/2011] [Accepted: 10/03/2011] [Indexed: 01/12/2023]
Abstract
Cell-cell connectivity is an absolute requirement for the correct functioning of cells, tissues and entire organisms. At the level of the individual cell, direct cell-cell adherence and communication is mediated by the intercellular junction complexes: desmosomes, adherens, tight and gap junctions. A broad spectrum of inherited, infectious and auto-immune diseases can affect the proper function of intercellular junctions and result in either diseases affecting specific individual tissues or widespread syndromic conditions. A particularly diverse group of diseases result from direct or indirect disruption of desmosomes--a consequence of their importance in tissue integrity, their extensive distribution, complex structure, and the wide variety of functions their components accomplish. As a consequence, disruption of desmosomal assembly, structure or integrity disrupts not only their intercellular adhesive function but also their functions in cell communication and regulation, leading to such diverse pathologies as cardiomyopathy, epidermal and mucosal blistering, palmoplantar keratoderma, woolly hair, keratosis, epidermolysis bullosa, ectodermal dysplasia and alopecia. Here, as well as describing the importance of the other intercellular junctions, we focus primarily on the desmosome, its structure and its role in disease. We will examine the various pathologies that result from impairment of desmosome function and thereby demonstrate the importance of desmosomes to tissues and to the organism as a whole.
Collapse
Affiliation(s)
- Matthew A Brooke
- Centre for Cutaneous Research, Blizard Institute, Barts and the London School of Medicine and Dentistry, London, UK
| | | | | |
Collapse
|
26
|
Lund LM, Kerr JP, Lupinetti J, Zhang Y, Russell MA, Bloch RJ, Bond M. Synemin isoforms differentially organize cell junctions and desmin filaments in neonatal cardiomyocytes. FASEB J 2011; 26:137-48. [PMID: 21982947 DOI: 10.1096/fj.10-179408] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Intermediate filaments (IFs) in cardiomyocytes consist primarily of desmin, surround myofibrils at Z disks, and transmit forces from the contracting myofilaments to the cell surface through costameres at the sarcolemma and desmosomes at intercalated disks. Synemin is a type IV IF protein that forms filaments with desmin and also binds α-actinin and vinculin. Here we examine the roles and expression of the α and β forms of synemin in developing rat cardiomyocytes. Quantitative PCR showed low levels of expression for both synemin mRNAs, which peaked at postnatal day 7. Synemin was concentrated at sites of cell-cell adhesion and at Z disks in neonatal cardiomyocytes. Overexpression of the individual isoforms showed that α-synemin preferentially localized to cell-cell junctions, whereas β-synemin was primarily at the level of Z disks. An siRNA targeted to both synemin isoforms reduced protein expression in cardiomyocytes by 70% and resulted in a failure of desmin to align with Z disks and disrupted cell-cell junctions, with no effect on sarcomeric organization. Solubility assays showed that β-synemin was soluble and interacted with sarcomeric α-actinin by coimmunoprecipitation, while α-synemin and desmin were insoluble. We conclude that β-synemin mediates the association of desmin IFs with Z disks, whereas α-synemin stabilizes junctional complexes between cardiomyocytes.
Collapse
Affiliation(s)
- Linda M Lund
- Department of Physiology, University of Maryland, Baltimore, MD 21201, USA.
| | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
Desmosomes are intercellular junctions that tether intermediate filaments to the plasma membrane. Desmogleins and desmocollins, members of the cadherin superfamily, mediate adhesion at desmosomes. Cytoplasmic components of the desmosome associate with the desmosomal cadherin tails through a series of protein interactions, which serve to recruit intermediate filaments to sites of desmosome assembly. These desmosomal plaque components include plakoglobin and the plakophilins, members of the armadillo gene family. Linkage to the cytoskeleton is mediated by the intermediate filament binding protein, desmoplakin, which associates with both plakoglobin and plakophilins. Although desmosomes are critical for maintaining stable cell-cell adhesion, emerging evidence indicates that they are also dynamic structures that contribute to cellular processes beyond that of cell adhesion. This article outlines the structure and function of the major desmosomal proteins, and explores the contributions of this protein complex to tissue architecture and morphogenesis.
Collapse
Affiliation(s)
- Emmanuella Delva
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
| | | | | |
Collapse
|
28
|
Ordered assembly of the adhesive and electrochemical connections within newly formed intercalated disks in primary cultures of adult rat cardiomyocytes. J Biomed Biotechnol 2010; 2010:624719. [PMID: 20467587 PMCID: PMC2868981 DOI: 10.1155/2010/624719] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2009] [Accepted: 02/17/2010] [Indexed: 02/06/2023] Open
Abstract
The intercalated disk (ID) is a complex structure that electromechanically couples adjoining cardiac myocytes into a functional syncitium. The integrity of the disk is essential for normal cardiac function, but how the diverse elements are assembled into a fully integrated structure is not well understood. In this study, we examined the assembly of new IDs in primary cultures of adult rat cardiac myocytes. From 2 to 5 days after dissociation, the cells flatten and spread, establishing new cell-cell contacts in a manner that recapitulates the in vivo processes that occur during heart development and myocardial remodeling. As cells make contact with their neighbors, transmembrane adhesion proteins localize along the line of apposition, concentrating at the sites of membrane attachment of the terminal sarcomeres. Cx43 gap junctions and ankyrin-G, an essential cytoskeletal component of voltage gated sodium channel complexes, were secondarily recruited to membrane domains involved in cell-cell contacts. The consistent order of the assembly process suggests that there are specific scaffolding requirements for integration of the mechanical and electrochemical elements of the disk. Defining the relationships that are the foundation of disk assembly has important implications for understanding the mechanical dysfunction and cardiac arrhythmias that accompany alterations of ID architecture.
Collapse
|
29
|
The area composita of adhering junctions connecting heart muscle cells of vertebrates. VII. The different types of lateral junctions between the special cardiomyocytes of the conduction system of ovine and bovine hearts. Eur J Cell Biol 2010; 89:365-78. [DOI: 10.1016/j.ejcb.2009.11.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 10/29/2009] [Accepted: 11/09/2009] [Indexed: 11/19/2022] Open
|
30
|
Pieperhoff S, Bennett W, Farrell AP. The intercellular organization of the two muscular systems in the adult salmonid heart, the compact and the spongy myocardium. J Anat 2009; 215:536-47. [PMID: 19627390 PMCID: PMC2780571 DOI: 10.1111/j.1469-7580.2009.01129.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2009] [Indexed: 01/12/2023] Open
Abstract
The ventricle of the salmonid heart consists of an outer compact layer of circumferentially arranged cardiomyocytes encasing a spongy myocardium that spans the lumen of the ventricle with a fine arrangement of muscular trabeculae. While many studies have detailed the anatomical structure of fish hearts, few have considered how these two cardiac muscle architectures are attached to form a functional working unit. The present study considers how the spindle-like cardiomyocytes, unlike the more rectangular structure of adult mammalian cardiomyocytes, form perpendicular connections between the two muscle layers that withstand the mechanical forces generated during cardiac systole and permit a simultaneous, coordinated contraction of both ventricular components. Therefore, hearts of rainbow trout (Oncorhynchus mykiss) and sockeye salmon (Oncorhynchus nerka) were investigated in detail using scanning electron microscopy (SEM) and various light microscopic techniques. In contrast to earlier suggestions, we found no evidence for a distinct connective tissue layer between the two muscle architectures that might 'glue' together the compact and the spongy myocardium. Instead, the contact layer between the compact and the spongy myocardium was characterized by a significantly higher amount of desmosome-like (D) and fascia adhaerens-like (FA) adhering junctions compared with either region alone. In addition, we observed that the trabeculae form muscular sheets of fairly uniform thickness and variable width rather than thick cylinders of variable diameter. This sheet-like trabecular anatomy would minimize diffusion distance while maximizing the area of contact between the trabecular muscle and the venous blood as well as the muscle tension generated by a single trabecular sheet.
Collapse
Affiliation(s)
- Sebastian Pieperhoff
- Department of Zoology and Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada.
| | | | | |
Collapse
|
31
|
Lin L, Wu XD, Davey AK, Wang J. The anti-inflammatory effect of baicalin on hypoxia/reoxygenation and TNF-α induced injury in cultural rat cardiomyocytes. Phytother Res 2009; 24:429-37. [DOI: 10.1002/ptr.3003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
32
|
Rickelt S, Franke WW, Doerflinger Y, Goerdt S, Brandner JM, Peitsch WK. Subtypes of melanocytes and melanoma cells distinguished by their intercellular contacts: heterotypic adherens junctions, adhesive associations, and dispersed desmoglein 2 glycoproteins. Cell Tissue Res 2008; 334:401-22. [PMID: 18975006 DOI: 10.1007/s00441-008-0704-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 09/17/2008] [Indexed: 12/11/2022]
Abstract
In the tissue integration of melanocytes and melanoma cells, an important role is attributed to cell adhesion molecules, notably the cadherins. In cultured melanoma cells, we have previously described a more heterogeneous repertoire of cadherins than normal, including some melanoma subtypes synthesizing the desmosomal cadherin, desmoglein 2, out of the desmosomal context. Using biochemical and immunological characterization of junctional molecules, confocal laser scanning, and electron and immunoelectron microscopy, we now demonstrate homo- and heterotypic cell-cell adhesions of normal epidermal melanocytes. In human epidermis, both in situ and in cell culture, melanocytes and keratinocytes are connected by closely aligned membranes that are interspersed by small puncta adhaerentia containing heterotypic complexes of E- and P-cadherin. Moreover, melanocytes growing in culture often begin to synthesize desmoglein 2, which is dispersed over extended areas of intimate adhesive cell-cell associations. As desmoglein 2 is not found in melanocytes in situ, we hypothesize that its synthesis is correlated with cell proliferation. Indeed, in tissue microarrays, desmoglein 2 has been demonstrated in a sizable subset of nevi and primary melanomas. The biological meanings of these cell-cell adhesion molecule arrangements, the possible diagnostic and prognostic significance of these findings, and the implications of the heterogeneity types of melanomas are discussed.
Collapse
Affiliation(s)
- Steffen Rickelt
- Helmholtz Group for Cell Biology, German Cancer Research Center, Heidelberg, Germany
| | | | | | | | | | | |
Collapse
|
33
|
Pieperhoff S, Franke WW. The area composita of adhering junctions connecting heart muscle cells of vertebrates. VI. Different precursor structures in non-mammalian species. Eur J Cell Biol 2008; 87:413-30. [PMID: 18420304 DOI: 10.1016/j.ejcb.2008.02.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 02/06/2008] [Accepted: 02/08/2008] [Indexed: 12/29/2022] Open
Abstract
Recent studies on the formation and molecular organization of the mammalian heart have emphasized the architectural and functional importance of the adhering junctions (AJs), which are densely clustered in the bipolar end regions (intercalated disks, IDs) connecting the elongated cardiomyocytes of the adult heart. Moreover, we learned from genetic studies of mutated AJ proteins that desmosomal proteins, which for the most part are integral components of ID-specific composite AJs (areae compositae, AC), are essential in heart development and function. Developmental studies have shown that the bipolar concentration of cardiomyocyte AJs in IDs is a rather late process and only completed postnatally. Here we report that in the adult hearts of diverse lower vertebrates (fishes, amphibia, birds) most AJs remain separate and distinct in molecular character, representing either fasciae adhaerentes, maculae adhaerentes (desmosomes) or--less frequently--some form of AC. In the mature hearts of the amphibian and fish species examined a large proportion of the AJs connecting cardiomyocytes is not clustered in the IDs but remains located on the lateral surfaces where they appear either as puncta adhaerentia or as desmosomes. In many places, these puncta connect parallel cardiomyocytes in spectacular ladder-like regular arrays (scalae adhaerentes) correlated with--and connected by--electron-dense plaque-like material to sarcomeric Z-bands. In the avian hearts, on the other hand, most AJs are clustered in the IDs but only a small proportion of the desmosomes appears as AC, compared to the dominance of distinct fasciae adhaerentes. We conclude that the fusion and amalgamation of AJs and desmosomes to ACs is a late process both in ontogenesis and in evolution. The significance and possible functional implications of the specific junctional structures in vertebrate evolution and the class-specific requirements of architectural and molecular assembly adaptation during regeneration processes are discussed.
Collapse
Affiliation(s)
- Sebastian Pieperhoff
- Division of Cell Biology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
| | | |
Collapse
|
34
|
Pieperhoff S, Schumacher H, Franke WW. The area composita of adhering junctions connecting heart muscle cells of vertebrates. V. The importance of plakophilin-2 demonstrated by small interference RNA-mediated knockdown in cultured rat cardiomyocytes. Eur J Cell Biol 2008; 87:399-411. [PMID: 18261826 DOI: 10.1016/j.ejcb.2007.12.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Revised: 12/11/2007] [Accepted: 12/14/2007] [Indexed: 12/21/2022] Open
Abstract
In the adult mammalian heart, the cardiomyocytes are connected by large polar arrays of closely spaced or even fused composite, plaque-bearing adhering junctions (areae compositae, ACs), in a region usually termed "intercalated disk" (ID). We have recently reported that during late embryogenesis and postnatally these polar assemblies of AC-junction structures are gradually formed as replacements of distinct embryonal junctions representing desmosomes and fasciae adhaerentes which then may amalgamate to the fused AC structures, in some regions occupying more than 90% of the total ID area. Previous gene knockout results as well as mutation analyses of specific human cardiomyopathies have suggested that among the various AC constituents, the desmosomal plaque protein, plakophilin-2, plays a particularly important role in the formation, architectural organization and stability of these junctions interconnecting mature cardiomyocytes. To examine this hypothesis, we have decided to study losses of--or molecular alterations in--such AC proteins with respect to their effects on myocardiac organization and functions. Here we report that plakophilin-2 is indeed of obvious importance for myocardial architecture and cell-cell coupling of rat cardiomyocytes growing in culture. We show that siRNA-mediated reduction of the cardiomyocyte content of plakophilin-2 but not of some other major plaque components such as desmoplakin results in progressive disintegration--and losses--of AC junction structures and that numerous variously sized vesicles appear, which are plaque protein-associated as demonstrable by immunofluorescence and immunoelectron microscopy. The importance of plakophilin-2 as a kind of "organizer" protein in the formation, stabilization and functions of the AC structure and the ID architecture is discussed in relation to other junction proteins and to causes of certain cardiomyopathies.
Collapse
Affiliation(s)
- Sebastian Pieperhoff
- Division of Cell Biology, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
| | | | | |
Collapse
|