1
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Sun C, Wen K, Zhang B, Dong Y, Chen C, Neo SY, Leng B, Gao TT, Wu J. DSC2 suppresses the growth of gastric cancer through the inhibition of nuclear translocation of γ-catenin and PTEN/PI3K/AKT signaling pathway. Aging (Albany NY) 2023; 15:6380-6399. [PMID: 37421607 PMCID: PMC10373986 DOI: 10.18632/aging.204858] [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: 03/14/2023] [Accepted: 06/15/2023] [Indexed: 07/10/2023]
Abstract
BACKGROUND Globally, gastric cancer (GC) is still a major leading cause of cancer-associated deaths. Downregulated desmocollin2 (DSC2) is considered to be closely related to tumor progression. However, the underlying mechanisms of DSC2 in GC progression require further exploration. METHOD We initially constructed different GC cells based on DSC2 contents, established the mouse tumor xenografts, and subsequently performed clonal formation, MTT, Caspase-3 activity, and sperm DNA fragmentation assays to detect the functions of DSC2 in GC growth. Subsequently, we performed western blot, Co-IP, and immunofluorescence assays to investigate the underlying mechanisms through pretreatment with PI3K inhibitor, LY294002, and its activator, recombinant human insulin-like growth factor I (IGF1). RESULT DSC2 could significantly inhibit the viability of GC cells at both in vitro and in vivo levels. The underlying mechanism may be that DSC2 binds the γ-catenin to decrease its nuclear level, thereby downregulating the anti-apoptotic factor BCL-2 expression and upregulating the pro-apoptotic factor P53 expression, which adjusts the PTEN/PI3K/AKT signaling pathway to promote the cancer cell apoptosis. CONCLUSIONS Our finding suggests that DSC2 might be a potential therapeutic target for the treatment of cancers, most especially GC.
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Affiliation(s)
- Chao Sun
- Department of Pharmacy, The Second Hospital of Shandong University, Jinan 250033, China
| | - Kun Wen
- Department of Critical Care Medicine, The Second Hospital of Shandong University, Jinan 250033, China
| | - Bin Zhang
- Department of Pharmacy, The Second Hospital of Shandong University, Jinan 250033, China
| | - Yan Dong
- Department of Pharmacy, The Second Hospital of Shandong University, Jinan 250033, China
| | - Chen Chen
- Department of Pharmacy, The Second Hospital of Shandong University, Jinan 250033, China
| | - Shi-Yong Neo
- Singapore Immunology Network, Singapore 138648, Singapore
| | - Bing Leng
- Department of Pharmacy, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan 250021, China
| | - Tian-Tian Gao
- Department of Pharmacy, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan 250021, China
| | - Jing Wu
- Department of Pharmacy, The First Affiliated Hospital of Shandong First Medical University and Shandong Provincial Qianfoshan Hospital, Jinan 250014, China
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2
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Nielsen MS, van Opbergen CJM, van Veen TAB, Delmar M. The intercalated disc: a unique organelle for electromechanical synchrony in cardiomyocytes. Physiol Rev 2023; 103:2271-2319. [PMID: 36731030 PMCID: PMC10191137 DOI: 10.1152/physrev.00021.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
The intercalated disc (ID) is a highly specialized structure that connects cardiomyocytes via mechanical and electrical junctions. Although described in some detail by light microscopy in the 19th century, it was in 1966 that electron microscopy images showed that the ID represented apposing cell borders and provided detailed insight into the complex ID nanostructure. Since then, much has been learned about the ID and its molecular composition, and it has become evident that a large number of proteins, not all of them involved in direct cell-to-cell coupling via mechanical or gap junctions, reside at the ID. Furthermore, an increasing number of functional interactions between ID components are emerging, leading to the concept that the ID is not the sum of isolated molecular silos but an interacting molecular complex, an "organelle" where components work in concert to bring about electrical and mechanical synchrony. The aim of the present review is to give a short historical account of the ID's discovery and an updated overview of its composition and organization, followed by a discussion of the physiological implications of the ID architecture and the local intermolecular interactions. The latter will focus on both the importance of normal conduction of cardiac action potentials as well as the impact on the pathophysiology of arrhythmias.
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Affiliation(s)
- Morten S Nielsen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chantal J M van Opbergen
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
| | - Toon A B van Veen
- Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mario Delmar
- The Leon Charney Division of Cardiology, New York University Grossmann School of Medicine, New York, New York, United States
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3
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Rogalska ME, Vafiadaki E, Erpapazoglou Z, Haghighi K, Green L, Mantzoros CS, Hajjar RJ, Tranter M, Karakikes I, Kranias EG, Stillitano F, Kafasla P, Sanoudou D. Isoform changes of action potential regulators in the ventricles of arrhythmogenic phospholamban-R14del humanized mouse hearts. Metabolism 2023; 138:155344. [PMID: 36375644 DOI: 10.1016/j.metabol.2022.155344] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 10/30/2022] [Accepted: 11/01/2022] [Indexed: 11/13/2022]
Abstract
Arrhythmogenic cardiomyopathy (ACM) is characterized by life-threatening ventricular arrhythmias and sudden cardiac death and affects hundreds of thousands of patients worldwide. The deletion of Arginine 14 (p.R14del) in the phospholamban (PLN) gene has been implicated in the pathogenesis of ACM. PLN is a key regulator of sarcoplasmic reticulum (SR) Ca2+ cycling and cardiac contractility. Despite global gene and protein expression studies, the molecular mechanisms of PLN-R14del ACM pathogenesis remain unclear. Using a humanized PLN-R14del mouse model and human induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs), we investigated the transcriptome-wide mRNA splicing changes associated with the R14del mutation. We identified >200 significant alternative splicing (AS) events and distinct AS profiles were observed in the right (RV) and left (LV) ventricles in PLN-R14del compared to WT mouse hearts. Enrichment analysis of the AS events showed that the most affected biological process was associated with "cardiac cell action potential", specifically in the RV. We found that splicing of 2 key genes, Trpm4 and Camk2d, which encode proteins regulating calcium homeostasis in the heart, were altered in PLN-R14del mouse hearts and human iPSC-CMs. Bioinformatical analysis pointed to the tissue-specific splicing factors Srrm4 and Nova1 as likely upstream regulators of the observed splicing changes in the PLN-R14del cardiomyocytes. Our findings suggest that aberrant splicing may affect Ca2+-homeostasis in the heart, contributing to the increased risk of arrythmogenesis in PLN-R14del ACM.
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Affiliation(s)
- Malgorzata E Rogalska
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
| | - Elizabeth Vafiadaki
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, 11527 Athens, Greece
| | - Zoi Erpapazoglou
- Institute for Fundamental Biomedical Research, B.S.R.C. "Alexander Fleming", 16672 Athens, Greece
| | - Kobra Haghighi
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Lisa Green
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Christos S Mantzoros
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA 02215, USA
| | | | - Michael Tranter
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Ioannis Karakikes
- Department of Cardiothoracic Surgery and Cardiovascular Institute, Stanford University School of Medicine, 240 Pasteur Dr, Stanford, CA 94304, USA
| | - Evangelia G Kranias
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Francesca Stillitano
- Division Heart and Lung, Department of Cardiology, University Medical Center Utrecht, 3584, CX, Utrecht, the Netherlands
| | - Panagiota Kafasla
- Institute for Fundamental Biomedical Research, B.S.R.C. "Alexander Fleming", 16672 Athens, Greece
| | - Despina Sanoudou
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, 11527 Athens, Greece; Clinical Genomics and Pharmacogenomics Unit, 4(th) Department of Internal Medicine, Attikon Hospital, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; Center for New Biotechnologies and Precision Medicine, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.
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4
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Towards a Better Understanding of Genotype-Phenotype Correlations and Therapeutic Targets for Cardiocutaneous Genes: The Importance of Functional Studies above Prediction. Int J Mol Sci 2022; 23:ijms231810765. [PMID: 36142674 PMCID: PMC9503274 DOI: 10.3390/ijms231810765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022] Open
Abstract
Genetic variants in gene-encoding proteins involved in cell−cell connecting structures, such as desmosomes and gap junctions, may cause a skin and/or cardiac phenotype, of which the combination is called cardiocutaneous syndrome. The cardiac phenotype is characterized by cardiomyopathy and/or arrhythmias, while the skin particularly displays phenotypes such as keratoderma, hair abnormalities and skin fragility. The reported variants associated with cardiocutaneous syndrome, in genes DSP, JUP, DSC2, KLHL24, GJA1, are classified by interpretation guidelines from the American College of Medical Genetics and Genomics. The genotype−phenotype correlation, however, remains poorly understood. By providing an overview of variants that are assessed for a functional protein pathology, we show that this number (n = 115) is low compared to the number of variants that are assessed by in silico algorithms (>5000). As expected, there is a mismatch between the prediction of variant pathogenicity and the prediction of the functional effect compared to the real functional evidence. Aiding to improve genotype−phenotype correlations, we separate variants into ‘protein reducing’ or ‘altered protein’ variants and provide general conclusions about the skin and heart phenotype involved. We conclude by stipulating that adequate prognoses can only be given, and targeted therapies can only be designed, upon full knowledge of the protein pathology through functional investigation.
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5
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Lin Y, Huang J, Zhu Z, Zhang Z, Xian J, Yang Z, Qin T, Chen L, Huang J, Huang Y, Wu Q, Hu Z, Lin X, Xu G. Overlap phenotypes of the left ventricular noncompaction and hypertrophic cardiomyopathy with complex arrhythmias and heart failure induced by the novel truncated DSC2 mutation. Orphanet J Rare Dis 2021; 16:496. [PMID: 34819141 PMCID: PMC8611834 DOI: 10.1186/s13023-021-02112-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 11/06/2021] [Indexed: 12/18/2022] Open
Abstract
Background The left ventricular noncompaction cardiomyopathy (LVNC) is a rare subtype of cardiomyopathy associated with a high risk of heart failure (HF), thromboembolism, arrhythmia, and sudden cardiac death. Methods The proband with overlap phenotypes of LVNC and hypertrophic cardiomyopathy (HCM) complicates atrial fibrillation (AF), ventricular tachycardia (VT), and HF due to the diffuse myocardial lesion, which were diagnosed by electrocardiogram, echocardiogram and cardiac magnetic resonance imaging. Peripheral blood was collected from the proband and his relatives. DNA was extracted from the peripheral blood of proband for high-throughput target capture sequencing. The Sanger sequence verified the variants. The protein was extracted from the skin of the proband and healthy volunteer. The expression difference of desmocollin2 was detected by Western blot. Results The novel heterozygous truncated mutation (p.K47Rfs*2) of the DSC2 gene encoding an important component of desmosomes was detected by targeted capture sequencing. The western blots showed that the expressing level of functional desmocollin2 protein (~ 94kd) was lower in the proband than that in the healthy volunteer, indicating that DSC2 p.K47Rfs*2 obviously reduced the functional desmocollin2 protein expression in the proband. Conclusion The heterozygous DSC2 p.K47Rfs*2 remarkably and abnormally reduced the functional desmocollin2 expression, which may potentially induce the overlap phenotypes of LVNC and HCM, complicating AF, VT, and HF.
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Affiliation(s)
- Yubi Lin
- The Center of Cardiovascular Diseases, The Department of Cardiology, Radiology and Ultrasonography, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China
| | - Jiana Huang
- The Center of Cardiovascular Diseases, The Department of Cardiology, Radiology and Ultrasonography, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China.,Reproductive Center, The Six Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510000, China
| | - Zhiling Zhu
- The Center of Cardiovascular Diseases, The Department of Cardiology, Radiology and Ultrasonography, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China
| | - Zuoquan Zhang
- The Center of Cardiovascular Diseases, The Department of Cardiology, Radiology and Ultrasonography, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China
| | - Jianzhong Xian
- The Center of Cardiovascular Diseases, The Department of Cardiology, Radiology and Ultrasonography, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China
| | - Zhe Yang
- The Center of Cardiovascular Diseases, The Department of Cardiology, Radiology and Ultrasonography, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China
| | - Tingfeng Qin
- Department of Physiology, The School of Medicine of Jinan University, Guangzhou, 510000, China
| | - Linxi Chen
- Department of Physiology, The School of Medicine of Jinan University, Guangzhou, 510000, China
| | - Jingmin Huang
- Department of Physiology, The School of Medicine of Jinan University, Guangzhou, 510000, China
| | - Yin Huang
- The Center of Cardiovascular Diseases, The Department of Cardiology, Radiology and Ultrasonography, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China
| | - Qiaoyun Wu
- The Center of Cardiovascular Diseases, The Department of Cardiology, Radiology and Ultrasonography, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China
| | - Zhenyu Hu
- The Center of Cardiovascular Diseases, The Department of Cardiology, Radiology and Ultrasonography, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China.,Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117593, Singapore
| | - Xiufang Lin
- The Center of Cardiovascular Diseases, The Department of Cardiology, Radiology and Ultrasonography, Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China.
| | - Geyang Xu
- Department of Physiology, The School of Medicine of Jinan University, Guangzhou, 510000, China.
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6
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Zhang J, Liang Y, Bradford WH, Sheikh F. Desmosomes: emerging pathways and non-canonical functions in cardiac arrhythmias and disease. Biophys Rev 2021; 13:697-706. [PMID: 34765046 PMCID: PMC8555023 DOI: 10.1007/s12551-021-00829-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/12/2021] [Indexed: 12/14/2022] Open
Abstract
Desmosomes are critical adhesion structures in cardiomyocytes, with mutation/loss linked to the heritable cardiac disease, arrhythmogenic right ventricular cardiomyopathy (ARVC). Early studies revealed the ability of desmosomal protein loss to trigger ARVC disease features including structural remodeling, arrhythmias, and inflammation; however, the precise mechanisms contributing to diverse disease presentations are not fully understood. Recent mechanistic studies demonstrated the protein degradation component CSN6 is a resident cardiac desmosomal protein which selectively restricts cardiomyocyte desmosomal degradation and disease. This suggests defects in protein degradation can trigger the structural remodeling underlying ARVC. Additionally, a subset of ARVC-related mutations show enhanced vulnerability to calpain-mediated degradation, further supporting the relevance of these mechanisms in disease. Desmosomal gene mutations/loss has been shown to impact arrhythmogenic pathways in the absence of structural disease within ARVC patients and model systems. Studies have shown the involvement of connexins, calcium handling machinery, and sodium channels as early drivers of arrhythmias, suggesting these may be distinct pathways regulating electrical function from the desmosome. Emerging evidence has suggested inflammation may be an early mechanism in disease pathogenesis, as clinical reports have shown an overlap between myocarditis and ARVC. Recent studies focus on the association between desmosomal mutations/loss and inflammatory processes including autoantibodies and signaling pathways as a way to understand the involvement of inflammation in ARVC pathogenesis. A specific focus will be to dissect ongoing fields of investigation to highlight diverse pathogenic pathways associated with desmosomal mutations/loss.
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Affiliation(s)
- Jing Zhang
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Yan Liang
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - William H. Bradford
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Farah Sheikh
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
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7
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Shiba M, Higo S, Kondo T, Li J, Liu L, Ikeda Y, Kohama Y, Kameda S, Tabata T, Inoue H, Nakamura S, Takeda M, Ito E, Takashima S, Miyagawa S, Sawa Y, Hikoso S, Sakata Y. Phenotypic recapitulation and correction of desmoglein-2-deficient cardiomyopathy using human-induced pluripotent stem cell-derived cardiomyocytes. Hum Mol Genet 2021; 30:1384-1397. [PMID: 33949662 PMCID: PMC8283207 DOI: 10.1093/hmg/ddab127] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/09/2021] [Accepted: 04/28/2021] [Indexed: 01/09/2023] Open
Abstract
Desmoglein-2, encoded by DSG2, is one of the desmosome proteins that maintain the structural integrity of tissues, including heart. Genetic mutations in DSG2 cause arrhythmogenic cardiomyopathy, mainly in an autosomal dominant manner. Here, we identified a homozygous stop-gain mutations in DSG2 (c.C355T, p.R119X) that led to complete desmoglein-2 deficiency in a patient with severe biventricular heart failure. Histological analysis revealed abnormal deposition of desmosome proteins, disrupted intercalated disk structures in the myocardium. Induced pluripotent stem cells (iPSCs) were generated from the patient (R119X-iPSC), and the mutated DSG2 gene locus was heterozygously corrected to a normal allele via homology-directed repair (HDR-iPSC). Both isogenic iPSCs were differentiated into cardiomyocytes [induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs)]. Multielectrode array analysis detected abnormal excitation in R119X-iPSC-CMs but not in HDR-iPSC-CMs. Micro-force testing of three-dimensional self-organized tissue rings (SOTRs) revealed tissue fragility and a weak maximum force in SOTRs from R119X-iPSC-CMs. Notably, these phenotypes were significantly recovered in HDR-iPSC-CMs. Myocardial fiber structures in R119X-iPSC-CMs were severely aberrant, and electron microscopic analysis confirmed that desmosomes were disrupted in these cells. Unexpectedly, the absence of desmoglein-2 in R119X-iPSC-CMs led to decreased expression of desmocollin-2 but no other desmosome proteins. Adeno-associated virus-mediated replacement of DSG2 significantly recovered the contraction force in SOTRs generated from R119X-iPSC-CMs. Our findings confirm the presence of a desmoglein-2-deficient cardiomyopathy among clinically diagnosed dilated cardiomyopathies. Recapitulation and correction of the disease phenotype using iPSC-CMs provide evidence to support the development of precision medicine and the proof of concept for gene replacement therapy for this cardiomyopathy.
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Affiliation(s)
- Mikio Shiba
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Shuichiro Higo
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.,Department of Medical Therapeutics for Heart Failure, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Takumi Kondo
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Junjun Li
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.,Department of Design for Tissue Regeneration, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Li Liu
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.,Department of Design for Tissue Regeneration, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Yoshihiko Ikeda
- Department of Pathology, National Cerebral and Cardiovascular Center, Suita, Osaka 564-8565, Japan
| | - Yasuaki Kohama
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Satoshi Kameda
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Tomoka Tabata
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Hiroyuki Inoue
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Satoki Nakamura
- Department of Medical Therapeutics for Heart Failure, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.,Department of Medical Biochemistry, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Maki Takeda
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Emiko Ito
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Seiji Takashima
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Shigeru Miyagawa
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Yoshiki Sawa
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Shungo Hikoso
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Yasushi Sakata
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
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8
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Ditaranto R, Caponetti AG, Ferrara V, Parisi V, Minnucci M, Chiti C, Baldassarre R, Di Nicola F, Bonetti S, Hasan T, Potena L, Galiè N, Ragni L, Biagini E. Pediatric Restrictive Cardiomyopathies. Front Pediatr 2021; 9:745365. [PMID: 35145940 PMCID: PMC8822222 DOI: 10.3389/fped.2021.745365] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 12/28/2021] [Indexed: 12/15/2022] Open
Abstract
Restrictive cardiomyopathy (RCM) is the least frequent phenotype among pediatric heart muscle diseases, representing only 2.5-3% of all cardiomyopathies diagnosed during childhood. Pediatric RCM has a poor prognosis, high incidence of pulmonary hypertension (PH), thromboembolic events, and sudden death, is less amenable to medical or surgical treatment with high mortality rates. In this scenario, heart transplantation remains the only successful therapeutic option. Despite a shared hemodynamic profile, characterized by severe diastolic dysfunction and restrictive ventricular filling, with normal ventricle ejection fraction and wall thickness, RCM recognizes a broad etiological spectrum, consisting of genetic/familial and acquired causes, each of which has a distinct pathophysiology and natural course. Hence, the aim of this review is to cover the causes, clinical presentation, diagnostic evaluation, treatment, and prognosis of pediatric RCM.
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Affiliation(s)
- Raffaello Ditaranto
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Angelo Giuseppe Caponetti
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Valentina Ferrara
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Vanda Parisi
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Matteo Minnucci
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Chiara Chiti
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Riccardo Baldassarre
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Federico Di Nicola
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Simone Bonetti
- Pediatric Cardiac Surgery and GUCH Unit, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Tammam Hasan
- Pediatric Cardiac Surgery and GUCH Unit, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Luciano Potena
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Nazzareno Galiè
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Luca Ragni
- Pediatric Cardiac Surgery and GUCH Unit, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
| | - Elena Biagini
- Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, IRCCS, Sant'Orsola Hospital, University of Bologna, Bologna, Italy
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9
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The intercalated disc: a mechanosensing signalling node in cardiomyopathy. Biophys Rev 2020; 12:931-946. [PMID: 32661904 PMCID: PMC7429531 DOI: 10.1007/s12551-020-00737-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 07/08/2020] [Indexed: 02/08/2023] Open
Abstract
Cardiomyocytes, the cells generating contractile force in the heart, are connected to each other through a highly specialised structure, the intercalated disc (ID), which ensures force transmission and transduction between neighbouring cells and allows the myocardium to function in synchrony. In addition, cardiomyocytes possess an intrinsic ability to sense mechanical changes and to regulate their own contractile output accordingly. To achieve this, some of the components responsible for force transmission have evolved to sense changes in tension and to trigger a biochemical response that results in molecular and cellular changes in cardiomyocytes. This becomes of particular importance in cardiomyopathies, where the heart is exposed to increased mechanical load and needs to adapt to sustain its contractile function. In this review, we will discuss key mechanosensing elements present at the intercalated disc and provide an overview of the signalling molecules involved in mediating the responses to changes in mechanical force.
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10
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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.
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11
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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.
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12
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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.
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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
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13
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Sun C, Wang L, Yang XX, Jiang YH, Guo XL. The aberrant expression or disruption of desmocollin2 in human diseases. Int J Biol Macromol 2019; 131:378-386. [DOI: 10.1016/j.ijbiomac.2019.03.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 03/05/2019] [Accepted: 03/05/2019] [Indexed: 12/21/2022]
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14
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Brodehl A, Stanasiuk C, Anselmetti D, Gummert J, Milting H. Incorporation of desmocollin-2 into the plasma membrane requires N-glycosylation at multiple sites. FEBS Open Bio 2019; 9:996-1007. [PMID: 30942563 PMCID: PMC6487837 DOI: 10.1002/2211-5463.12631] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 02/28/2019] [Accepted: 03/21/2019] [Indexed: 12/11/2022] Open
Abstract
Desmocollin‐2 (DSC2) is a desmosomal protein of the cadherin family. Desmosomes are multiprotein complexes, which are involved in cell adhesion of cardiomyocytes and of keratinocytes. The molecular structure of the complete extracellular domain (ECD) of DSC2 was recently described, revealing three disulfide bridges, four N‐glycosylation sites, and four O‐mannosylation sites. However, the functional relevance of these post‐translational modifications for the protein trafficking of DSC2 to the plasma membrane is still unknown. Here, we generated a set of DSC2 mutants, in which we systematically exchanged all N‐glycosylation sites, O‐mannosylation sites, and disulfide bridges within the ECD and investigated the resulting subcellular localization by confocal laser scanning microscopy. Of note, all single and double N‐glycosylation‐ deficient mutants were efficiently incorporated into the plasma membrane, indicating that the absence of these glycosylation sites has a minor effect on the protein trafficking of DSC2. However, the exchange of multiple N‐glycosylation sites resulted in intracellular accumulation. Colocalization analysis using cell compartment trackers revealed that N‐glycosylation‐ deficient DSC2 mutants were retained within the Golgi apparatus. In contrast, elimination of the four O‐mannosylation sites or the disulfide bridges in the ECD has no obvious effect on the intracellular protein processing of DSC2. These experiments underscore the importance of N‐glycosylation at multiple sites of DSC2 for efficient intracellular transport to the plasma membrane.
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Affiliation(s)
- Andreas Brodehl
- Erich and Hanna Klessmann Institute for Cardiovascular Research & Development (EHKI), Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Oeynhausen, Germany
| | - Caroline Stanasiuk
- Erich and Hanna Klessmann Institute for Cardiovascular Research & Development (EHKI), Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Oeynhausen, Germany
| | - Dario Anselmetti
- Faculty of Physics, Experimental Biophysics and Applied Nanoscience, Bielefeld Institute for Nanoscience (BINAS), Bielefeld University, Germany
| | - Jan Gummert
- Erich and Hanna Klessmann Institute for Cardiovascular Research & Development (EHKI), Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Oeynhausen, Germany
| | - Hendrik Milting
- Erich and Hanna Klessmann Institute for Cardiovascular Research & Development (EHKI), Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Oeynhausen, Germany
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15
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Genetics of and pathogenic mechanisms in arrhythmogenic right ventricular cardiomyopathy. Biophys Rev 2018; 10:973-982. [PMID: 29995277 DOI: 10.1007/s12551-018-0437-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 06/28/2018] [Indexed: 02/06/2023] Open
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart disease, associated with a high risk of sudden cardiac death. ARVC has been termed a 'disease of the desmosome' based on the fact that in many cases, it is caused by mutations in genes encoding desmosomal proteins at the specialised intercellular junctions between cardiomyocytes, the intercalated discs. Desmosomes maintain the structural integrity of the ventricular myocardium and are also implicated in signal transduction pathways. Mutated desmosomal proteins are thought to cause detachment of cardiac myocytes by the loss of cellular adhesions and also affect signalling pathways, leading to cell death and substitution by fibrofatty adipocytic tissue. However, mutations in desmosomal proteins are not the sole cause for ARVC as mutations in non-desmosomal genes were also implicated in its pathogenesis. This review will consider the pathology, genetic basis and mechanisms of pathogenesis for ARVC.
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16
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Brodehl A, Gaertner-Rommel A, Milting H. Molecular insights into cardiomyopathies associated with desmin (DES) mutations. Biophys Rev 2018; 10:983-1006. [PMID: 29926427 DOI: 10.1007/s12551-018-0429-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 05/22/2018] [Indexed: 12/15/2022] Open
Abstract
Increasing usage of next-generation sequencing techniques pushed during the last decade cardiogenetic diagnostics leading to the identification of a huge number of genetic variants in about 170 genes associated with cardiomyopathies, channelopathies, or syndromes with cardiac involvement. Because of the biochemical and cellular complexity, it is challenging to understand the clinical meaning or even the relevant pathomechanisms of the majority of genetic sequence variants. However, detailed knowledge about the associated molecular pathomechanism is essential for the development of efficient therapeutic strategies in future and genetic counseling. Mutations in DES, encoding the muscle-specific intermediate filament protein desmin, have been identified in different kinds of cardiac and skeletal myopathies. Here, we review the functions of desmin in health and disease with a focus on cardiomyopathies. In addition, we will summarize the genetic and clinical literature about DES mutations and will explain relevant cell and animal models. Moreover, we discuss upcoming perspectives and consequences of novel experimental approaches like genome editing technology, which might open a novel research field contributing to the development of efficient and mutation-specific treatment options.
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Affiliation(s)
- Andreas Brodehl
- Erich and Hanna Klessmann Institute for Cardiovascular Research & Development, Heart and Diabetes Centre NRW, Ruhr-University Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany.
| | - Anna Gaertner-Rommel
- Erich and Hanna Klessmann Institute for Cardiovascular Research & Development, Heart and Diabetes Centre NRW, Ruhr-University Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany
| | - Hendrik Milting
- Erich and Hanna Klessmann Institute for Cardiovascular Research & Development, Heart and Diabetes Centre NRW, Ruhr-University Bochum, Georgstrasse 11, 32545, Bad Oeynhausen, Germany.
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17
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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.
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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.
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18
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Hoorntje ET, Te Rijdt WP, James CA, Pilichou K, Basso C, Judge DP, Bezzina CR, van Tintelen JP. Arrhythmogenic cardiomyopathy: pathology, genetics, and concepts in pathogenesis. Cardiovasc Res 2018; 113:1521-1531. [PMID: 28957532 DOI: 10.1093/cvr/cvx150] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 08/03/2017] [Indexed: 02/06/2023] Open
Abstract
Arrhythmogenic cardiomyopathy (ACM) is a rare, heritable heart disease characterized by fibro-fatty replacement of the myocardium and a high degree of electric instability. It was first thought to be a congenital disorder, but is now regarded as a dystrophic heart muscle disease that develops over time. There is no curative treatment and current treatment strategies focus on attenuating the symptoms, slowing disease progression, and preventing life-threatening arrhythmias and sudden cardiac death. Identification of mutations in genes encoding desmosomal proteins and in other genes has led to insights into the disease pathogenesis and greatly facilitated identification of family members at risk. The disease phenotype is, however, highly variable and characterized by incomplete penetrance. Although the reasons are still poorly understood, sex, endurance exercise and a gene-dosage effect seem to play a role in these phenomena. The discovery of the genes and mutations implicated in ACM has allowed animal and cellular models to be generated, enabling researchers to start unravelling it's underlying molecular mechanisms. Observations in humans and in animal models suggest that reduced cell-cell adhesion affects gap junction and ion channel remodelling at the intercalated disc, and along with impaired desmosomal function, these can lead to perturbations in signalling cascades like the Wnt/β-catenin and Hippo/YAP pathways. Perturbations of these pathways are also thought to lead to fibro-fatty replacement. A better understanding of the molecular processes may lead to new therapies that target specific pathways involved in ACM.
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Affiliation(s)
- Edgar T Hoorntje
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.,Netherlands Heart Institute, Moreelsepark 1, 3511 EP, Utrecht, The Netherlands
| | - Wouter P Te Rijdt
- Department of Genetics, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Cynthia A James
- Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, 1800 Orleans Street, Baltimore, MD, USA
| | - Kalliopi Pilichou
- Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua 35121, Italy
| | - Cristina Basso
- Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padua 35121, Italy
| | - Daniel P Judge
- Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, 1800 Orleans Street, Baltimore, MD, USA
| | - Connie R Bezzina
- Department of Clinical and Experimental Cardiology, Heart Centre, Academic Medical Centre, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - J Peter van Tintelen
- Netherlands Heart Institute, Moreelsepark 1, 3511 EP, Utrecht, The Netherlands.,Department of Clinical Genetics, Academic Medical Centre Amsterdam, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
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19
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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.
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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.
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20
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Mazurek SR, Calway T, Harmon C, Farrell P, Kim GH. MicroRNA-130a Regulation of Desmocollin 2 in a Novel Model of Arrhythmogenic Cardiomyopathy. Microrna 2018; 6:143-150. [PMID: 27834139 DOI: 10.2174/2211536605666161109111031] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/17/2016] [Accepted: 10/27/2016] [Indexed: 01/27/2023]
Abstract
BACKGROUND MicroRNAs are small noncoding RNA molecules that play a critical role in regulating physiological and disease processes. Recent studies have now recognized microRNAs as an important player in cardiac arrhythmogenesis. Molecular insight into arrhythmogenic cardiomyopathy (AC) has primarily focused on mutations in desmosome proteins. To our knowledge, models of AC due to microRNA dysregulation have not been reported. Previously, we reported on miR-130a mediated down-regulation of Connexin43. OBJECTIVE Here, we investigate miR-130a-mediated translational repression of Desmocollin2 (DSC2), as it has a predicted target site for miR-130a. DSC2 is an important protein for cell adhesion, which has been shown to be dysregulated in human AC. METHOD & RESULTS After induction of miR-130a, transgenic mice demonstrated right ventricular dilation. Surface ECG revealed spontaneous premature ventricular complexes confirming an arrhythmogenic phenotype in αMHC-miR130a mice. Using total protein from whole ventricular lysate, western blot analysis demonstrated an 80% reduction in DSC2 levels in transgenic myocardium. Furthermore, immunofluorescent staining confirmed downregulation of DSC2 in transgenic compared with littermate control myocardium. In transgenic hearts, histologic findings revealed fibrosis and lipid accumulation within both ventricles. To validate DSC2 as a direct target of miR-130a, we performed in vitro target assays in 3T3 fibroblasts, known to express miR-130a. Using a luciferase reporter fused to the 3UTR of DSC2 compared with a control, we found a 42% reduction in luciferase activity with the DSC2 3UTR. This reduction was reversed upon selective inhibition of miR-130a. CONCLUSION Overexpression of miR-130a results in a disease phenotype characteristic of AC and therefore, may serve as potential model for microRNA-induced AC.
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Affiliation(s)
- Stefan R Mazurek
- Department of Medicine, University of Chicago, Chicago, IL 60637. United States
| | - Tyler Calway
- Department of Medicine, University of Chicago, Chicago, IL 60637. United States
| | - Cynthia Harmon
- Department of Medicine, University of Chicago, Chicago, IL 60637. United States
| | - Priyanka Farrell
- Department of Medicine, University of Chicago, Chicago, IL 60637. United States
| | - Gene H Kim
- Department of Medicine, University of Chicago, Chicago, IL 60637. United States
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21
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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]
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22
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Liu JS, Fan LL, Li JJ, Xiang R. Whole-Exome Sequencing Identifies a Novel Mutation of Desmocollin 2 in a Chinese Family With Arrhythmogenic Right Ventricular Cardiomyopathy. Am J Cardiol 2017; 119:1485-1489. [PMID: 28256248 DOI: 10.1016/j.amjcard.2017.01.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 01/25/2017] [Accepted: 01/25/2017] [Indexed: 11/15/2022]
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare heart disorder characterized by myocyte loss and fibro-fatty tissue replacement. With the progress of ARVC, patient can present serious ventricular arrhythmias, heart failure, and even sudden cardiac death. Previous studies have revealed that the generation and development of ARVC are related to structural changes of desmosomes. To date, at least 5 genes associated with desmosomes have been identified in patients with ARVC, including Desmoplakin, Plakophilin 2, Desmoglein 2, Desmocollin 2, and Junction plakoglobin. In this study, we applied whole-exome sequencing to explore the potential causative gene in a Chinese family with suspicious ARVC. A novel missense mutation (c.1090 G > A/p.V364 M) of DSC2 was identified and co-segregated with the affected family members. This mutation leads to a substitution of valine by methionine and is predicted to be damaging by bioinformatics tools. In conclusion, our study not only expands the spectrum of DSC2 mutations and contributes to genetic counseling of families with ARVC but also improves the awareness of pathogenesis in Chinese patients with ARVC.
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Affiliation(s)
- Ji-Shi Liu
- Department of Nephrology, The Third Xiangya Hospital of Central South University, Changsha, China; Department of Cell Biology, The State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Liang-Liang Fan
- Department of Cell Biology, The State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Jing-Jing Li
- Department of Cell Biology, The State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Rong Xiang
- Department of Cell Biology, The State Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China.
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23
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Schinner C, Vielmuth F, Rötzer V, Hiermaier M, Radeva MY, Co TK, Hartlieb E, Schmidt A, Imhof A, Messoudi A, Horn A, Schlipp A, Spindler V, Waschke J. Adrenergic Signaling Strengthens Cardiac Myocyte Cohesion. Circ Res 2017; 120:1305-1317. [PMID: 28289018 DOI: 10.1161/circresaha.116.309631] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 02/22/2017] [Accepted: 03/10/2017] [Indexed: 01/08/2023]
Abstract
RATIONALE The sympathetic nervous system is a major mediator of heart function. Intercalated discs composed of desmosomes, adherens junctions, and gap junctions provide the structural backbone for coordinated contraction of cardiac myocytes. OBJECTIVE Gap junctions dynamically remodel to adapt to sympathetic signaling. However, it is unknown whether such rapid adaption also occurs for the adhesive function provided by desmosomes and adherens junctions. METHODS AND RESULTS Atomic force microscopy revealed that β-adrenergic signaling enhances both the number of desmoglein 2-specific interactions along cell junctions and the mean desmoglein 2-mediated binding forces, whereas N-cadherin-mediated interactions were not affected. This was accompanied by increased cell cohesion in cardiac myocyte cultures and murine heart slices. Enhanced desmoglein 2-positive contacts and increased junction length as revealed by immunofluorescence and electron microscopy reflected cAMP-induced reorganization of intercellular contacts. The mechanism underlying cAMP-mediated strengthening of desmoglein 2 binding was dependent on expression of the intercalated disc plaque protein plakoglobin (Pg) and direct phosphorylation at S665 by protein kinase A: Pg deficiency as well as overexpression of the phospho-deficient Pg-mutant S665A abrogated both cAMP-mediated junctional remodeling and increase of cohesion. Moreover, Pg knockout hearts failed to functionally adapt to adrenergic stimulation. CONCLUSIONS Taken together, we provide first evidence for positive adhesiotropy as a new cardiac function of sympathetic signaling. Positive adhesiotropy is dependent on Pg phosphorylation at S665 by protein kinase A. This mechanism may be of high medical relevance because loss of junctional Pg is a hallmark of arrhythmogenic cardiomyopathy.
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Affiliation(s)
- Camilla Schinner
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Franziska Vielmuth
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Vera Rötzer
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Matthias Hiermaier
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Mariya Y Radeva
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Thu Kim Co
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Eva Hartlieb
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Andreas Schmidt
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Axel Imhof
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Ahmed Messoudi
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Anja Horn
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Angela Schlipp
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Volker Spindler
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany
| | - Jens Waschke
- From the Institute of Anatomy and Cell Biology (C.S., F.V., V.R., M.H., M.Y.R., T.K.C., E.H., A.M., A.H., A. Schlipp, V.S., J.W.) and Biomedical Center and Center for Integrated Protein Sciences Munich (A. Schmidt, A.I.), Ludwig-Maximilians-Universität, Germany.
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Ehler E. Cardiac cytoarchitecture - why the "hardware" is important for heart function! BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:1857-63. [PMID: 26577135 PMCID: PMC5104690 DOI: 10.1016/j.bbamcr.2015.11.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/05/2015] [Accepted: 11/09/2015] [Indexed: 01/05/2023]
Abstract
Cells that constitute fully differentiated tissues are characterised by an architecture that makes them perfectly suited for the job they have to do. This is especially obvious for cardiomyocytes, which have an extremely regular shape and display a paracrystalline arrangement of their cytoplasmic components. This article will focus on the two major cytoskeletal multiprotein complexes that are found in cardiomyocytes, the myofibrils, which are responsible for contraction and the intercalated disc, which mediates mechanical and electrochemical contact between individual cardiomyocytes. Recent studies have revealed that these two sites are also crucial in sensing excessive mechanical strain. Signalling processes will be triggered that## lead to changes in gene expression and eventually lead to an altered cardiac cytoarchitecture in the diseased heart, which results in a compromised function. Thus, understanding these changes and the signals that lead to them is crucial to design treatment strategies that can attenuate these processes. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
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Affiliation(s)
- Elisabeth Ehler
- BHF Centre of Research Excellence at King's College London, Cardiovascular Division and Randall Division of Cell and Molecular Biophysics, London, UK.
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Kant S, Holthöfer B, Magin TM, Krusche CA, Leube RE. Desmoglein 2-Dependent Arrhythmogenic Cardiomyopathy Is Caused by a Loss of Adhesive Function. ACTA ACUST UNITED AC 2015; 8:553-63. [PMID: 26085008 DOI: 10.1161/circgenetics.114.000974] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 06/09/2015] [Indexed: 01/01/2023]
Abstract
BACKGROUND The desmosomal cadherin desmoglein 2 (Dsg2) localizes to the intercalated disc coupling adjacent cardiomyocytes. Desmoglein 2 gene (DSG2) mutations cause arrhythmogenic cardiomyopathy (AC) in human and transgenic mice. AC is characterized by arrhythmia, cardiodilation, cardiomyocyte necrosis with replacement fibrosis, interstitial fibrosis, and intercalated disc dissociation. The genetic DSG2 constellations encountered are compatible with loss of adhesion and altered signaling. To further elucidate pathomechanisms, we examined whether heart-specific Dsg2 depletion triggers cardiomyopathy. METHODS AND RESULTS Because DSG2 knockouts die during early embryogenesis, mice were prepared with cardiomyocyte-specific DSG2 ablation. Healthy transgenic animals were born with a functional heart presenting intercalated discs with incorporated desmosomal proteins. Dsg2 protein expression was reduced below 3% in the heart. All animals developed AC during postnatal growth with pronounced chamber dilation, calcifying cardiomyocyte necrosis, aseptic inflammation, interstitial and focal replacement fibrosis, and conduction defects with altered connexin 43 distribution. Electron microscopy revealed absence of desmosome-like structures and regional loss of intercalated disc adhesion. Mice carrying 2 mutant DSG2 alleles coding for Dsg2 lacking part of the adhesive EC1-EC2 domains present an indistinguishable phenotype, which is similar to that observed in human AC patients. CONCLUSIONS The observations show that the presence of Dsg2 is not essential for late heart morphogenesis and for cardiac contractility to support postnatal life. On increasing mechanical demands, heart function is severely compromised as evidenced by the onset of cardiomyopathy with pronounced morphological alterations. We propose that loss of Dsg2 compromises adhesion, and that this is a major pathogenic mechanism in DSG2-related and probably other desmosome-related ACs.
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Affiliation(s)
- Sebastian Kant
- From the Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany (S.K., B.H., C.A.K., R.E.L.); and Institute of Biology and Translational Center for Regenerative Medicine, University of Leipzig, Leipzig, Germany (T.M.M.)
| | - Bastian Holthöfer
- From the Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany (S.K., B.H., C.A.K., R.E.L.); and Institute of Biology and Translational Center for Regenerative Medicine, University of Leipzig, Leipzig, Germany (T.M.M.)
| | - Thomas M Magin
- From the Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany (S.K., B.H., C.A.K., R.E.L.); and Institute of Biology and Translational Center for Regenerative Medicine, University of Leipzig, Leipzig, Germany (T.M.M.)
| | - Claudia A Krusche
- From the Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany (S.K., B.H., C.A.K., R.E.L.); and Institute of Biology and Translational Center for Regenerative Medicine, University of Leipzig, Leipzig, Germany (T.M.M.)
| | - Rudolf E Leube
- From the Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Aachen, Germany (S.K., B.H., C.A.K., R.E.L.); and Institute of Biology and Translational Center for Regenerative Medicine, University of Leipzig, Leipzig, Germany (T.M.M.).
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Mo W, Tong C, Zhang Y, Lu H. microRNAs' differential regulations mediate the progress of Human Papillomavirus (HPV)-induced Cervical Intraepithelial Neoplasia (CIN). BMC SYSTEMS BIOLOGY 2015; 9:4. [PMID: 25889737 PMCID: PMC4337110 DOI: 10.1186/s12918-015-0145-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 01/16/2015] [Indexed: 11/14/2022]
Abstract
Background microRNA (miRNA)’s direct regulation on target mRNA is affected by complex factors beyond miRNA. Therefore, at different stages during the course of carcinogenesis, miRNA may regulate different targets, which we termed ‘miRNA’s differential regulation’. HPV-induced cervical intraepithelial neoplasia (CIN) is an important pre-cancerous course ahead of cervical cancer formation. Currently, the molecular mechanisms of CIN progress remain poorly understood, and it is interesting to unravel this from the perspective of miRNA differential regulation. Results In this study, we performed transcriptome analysis of miRNAs and mRNAs for the totally 24 cervical samples in three stages (normal, CIN I, and CIN III) along CIN progress, and proposed the SIG++ algorithm to detect the miRNA — mRNA pairs with significant regulation change, and further proposed the definitions of Efficient Pair, Efficient Target, and Related Effector Biological Process, as the elemental steps to construct miRNA differential regulatory network. Finally, for the course of disease progressing from normal stage to CIN I stage, and for the course of disease progressing from CIN I stage to CIN III stage, miRNA differential regulatory networks were constructed, respectively, based on two distinct strategies: one is founded on the knowledge of human GO biological processes to detect Efficient Targets and Related Effector Biological Processes, the other is solely founded on literature review to detect the targets closely related to cervical carcinogenesis and instructive in revealing mechanisms that promote CIN development. Conclusions This study provided the conception of miRNA’s differential regulation, the algorithm for how to identify them during disease development, and the strategy for how to construct miRNA differential regulatory network with instructive biological meanings. The finally constructed networks provide clues for understanding CIN progress. Electronic supplementary material The online version of this article (doi:10.1186/s12918-015-0145-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wenjuan Mo
- State Key Laboratory of Genetic Engineering, School of Life Science, and Institute of Biomedical Sciences, Fudan University, 200433, Shanghai, China. .,Shanghai Engineering Research Center of Industrial Microorganisms, 200433, Shanghai, China. .,Collaborative Innovation Center of Cancer Medicine, 200433, Shanghai, China.
| | - Chao Tong
- State Key Laboratory of Genetic Engineering, School of Life Science, and Institute of Biomedical Sciences, Fudan University, 200433, Shanghai, China. .,Shanghai Engineering Research Center of Industrial Microorganisms, 200433, Shanghai, China. .,Collaborative Innovation Center of Cancer Medicine, 200433, Shanghai, China.
| | - Yan Zhang
- Department of Gynaecology and Obstetrics in Changhai Hospital, 200433, Shanghai, China.
| | - Hong Lu
- State Key Laboratory of Genetic Engineering, School of Life Science, and Institute of Biomedical Sciences, Fudan University, 200433, Shanghai, China. .,Shanghai Engineering Research Center of Industrial Microorganisms, 200433, Shanghai, China. .,Collaborative Innovation Center of Cancer Medicine, 200433, Shanghai, China.
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27
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Schlipp A, Schinner C, Spindler V, Vielmuth F, Gehmlich K, Syrris P, Mckenna WJ, Dendorfer A, Hartlieb E, Waschke J. Desmoglein-2 interaction is crucial for cardiomyocyte cohesion and function. Cardiovasc Res 2014; 104:245-57. [DOI: 10.1093/cvr/cvu206] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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28
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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]
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Lyon RC, Mezzano V, Wright AT, Pfeiffer E, Chuang J, Banares K, Castaneda A, Ouyang K, Cui L, Contu R, Gu Y, Evans SM, Omens JH, Peterson KL, McCulloch AD, Sheikh F. Connexin defects underlie arrhythmogenic right ventricular cardiomyopathy in a novel mouse model. Hum Mol Genet 2014; 23:1134-50. [PMID: 24108106 PMCID: PMC3919010 DOI: 10.1093/hmg/ddt508] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/06/2013] [Accepted: 10/04/2013] [Indexed: 12/27/2022] Open
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) termed a 'disease of the desmosome' is an inherited cardiomyopathy that recently underwent reclassification owing to the identification of left-dominant and biventricular disease forms. Homozygous loss-of-function mutations in the desmosomal component, desmoplakin, are found in patients exhibiting a biventricular form of ARVC; however, no models recapitulate the postnatal hallmarks of the disease as seen in these patients. To gain insights into the homozygous loss-of-function effects of desmoplakin in the heart, we generated cardiomyocyte-specific desmoplakin-deficient mice (DSP-cKO) using ventricular myosin light chain-2-Cre mice. Homozygous DSP-cKO mice are viable but display early ultrastructural defects in desmosomal integrity leading to a cardiomyopathy reminiscent of a biventricular form of ARVC, which includes cell death and fibro-fatty replacement within the ventricle leading to biventricular dysfunction, failure and premature death. DSP-cKO mice also exhibited ventricular arrhythmias that are exacerbated with exercise and catecholamine stimulation. Furthermore, DSP-cKO hearts exhibited right ventricular conduction defects associated with loss of connexin 40 expression and electrical wavefront propagation defects associated with loss of connexin 43 expression. Dose-dependent assessment of the effects of loss of desmoplakin in neonatal ventricular cardiomyocytes revealed primary loss of connexin 43 levels, phosphorylation and function independent of the molecular dissociation of the mechanical junction complex and fibro-fatty manifestation associated with ARVC, suggesting a role for desmoplakin as a primary stabilizer of connexin integrity. In summary, we provide evidence for a novel mouse model, which is reminiscent of the postnatal onset of ARVC while highlighting mechanisms underlying a biventricular form of human ARVC.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Li Cui
- Department of Skaggs School of Pharmacy, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | | | | | - Sylvia M. Evans
- Department of Skaggs School of Pharmacy, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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Vite A, Gandjbakhch E, Prost C, Fressart V, Fouret P, Neyroud N, Gary F, Donal E, Varnous S, Fontaine G, Fornes P, Hidden-Lucet F, Komajda M, Charron P, Villard E. Desmosomal cadherins are decreased in explanted arrhythmogenic right ventricular dysplasia/cardiomyopathy patient hearts. PLoS One 2013; 8:e75082. [PMID: 24086444 PMCID: PMC3781033 DOI: 10.1371/journal.pone.0075082] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 08/12/2013] [Indexed: 11/19/2022] Open
Abstract
Aims Arrhythmogenic right ventricular Dysplasia/cardiomyopathy (ARVD/C) is an autosomal dominant inherited cardiomyopathy associated with ventricular arrhythmia, heart failure and sudden death. Genetic studies have demonstrated the central role of desmosomal proteins in this disease, where 50% of patients harbor a mutation in a desmosmal gene. However, clinical diagnosis of the disease remains difficult and molecular mechanisms appears heterogeneous and poorly understood. The aim of this study was to characterize the expression profile of desmosomal proteins in explanted ARVD/C heart samples, in order to identify common features of the disease. Methods and Results We examined plakophilin-2, desmoglein-2, desmocollin-2, plakoglobin and β-catenin protein expression levels from seven independent ARVD/C heart samples compared to two ischemic, five dilated cardiomyopathy and one healthy heart sample as controls. Ventricular and septum sections were examined by immunoblot analysis of total heart protein extracts and by immunostaining. Immunoblots indicated significant decreases in desmoglein-2 and desmocollin-2, independent of any known underlying mutations, whereas immune-histochemical analysis showed normal localization of all desmosomal proteins. Quantitative RT-PCR revealed normal DSG2 and DSC2 mRNA transcript levels, suggesting increased protein turn-over rather than transcriptional down regulation. Conclusion Reduced cardiac desmoglein-2 and desmocollin-2 levels appear to be specifically associated with ARVD/C, independent of underlying mutations. These findings highlight a key role of desmosomal cadherins in the pathophysiology of ARVD/C. Whether these reductions could be considered as specific markers for ARVD/C requires replication analysis.
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Affiliation(s)
- Alexia Vite
- UPMC, University Paris 06, Hôpital Pitié-Salpêtrière, Paris, France
- INSERM, UMR_S956, ICAN, Hôpital Pitié-Salpêtrière, Paris, France
| | - Estelle Gandjbakhch
- UPMC, University Paris 06, Hôpital Pitié-Salpêtrière, Paris, France
- INSERM, UMR_S956, ICAN, Hôpital Pitié-Salpêtrière, Paris, France
- Institut de Cardiologie (AP-HP), Hôpital Pitié-Salpêtrière, Paris, France
| | - Catherine Prost
- Laboratoire d’histologie et de thérapie génique, University Paris XIII, Bobigny, France
- Département de Pathologie, University Paris V, Hôpital Necker enfants malades, Paris, France
| | - Veronique Fressart
- Service de Biochimie Métabolique, Unité de Cardiogénétique, Hôpital Pitié-Salpêtrière, Paris, France
| | - Pierre Fouret
- UPMC, University Paris 06, Hôpital Pitié-Salpêtrière, Paris, France
- Service d’Anatomie Pathologique, Hôpital Pitié-Salpêtrière, Paris, France
| | - Nathalie Neyroud
- UPMC, University Paris 06, Hôpital Pitié-Salpêtrière, Paris, France
- INSERM, UMR_S956, ICAN, Hôpital Pitié-Salpêtrière, Paris, France
| | - Françoise Gary
- UPMC, University Paris 06, Hôpital Pitié-Salpêtrière, Paris, France
- INSERM, UMR_S956, ICAN, Hôpital Pitié-Salpêtrière, Paris, France
| | - Erwan Donal
- Département de Cardiologie, Hôpital Pontchaillou, Rennes, France
| | - Shaida Varnous
- Institut de Cardiologie (AP-HP), Hôpital Pitié-Salpêtrière, Paris, France
| | - Guy Fontaine
- Institut de Cardiologie (AP-HP), Hôpital Pitié-Salpêtrière, Paris, France
| | - Paul Fornes
- Département de Pathologie, Hôpital universitaire, Reims
| | | | - Michel Komajda
- UPMC, University Paris 06, Hôpital Pitié-Salpêtrière, Paris, France
- INSERM, UMR_S956, ICAN, Hôpital Pitié-Salpêtrière, Paris, France
- Institut de Cardiologie (AP-HP), Hôpital Pitié-Salpêtrière, Paris, France
| | - Philippe Charron
- UPMC, University Paris 06, Hôpital Pitié-Salpêtrière, Paris, France
- INSERM, UMR_S956, ICAN, Hôpital Pitié-Salpêtrière, Paris, France
- Institut de Cardiologie (AP-HP), Hôpital Pitié-Salpêtrière, Paris, France
| | - Eric Villard
- UPMC, University Paris 06, Hôpital Pitié-Salpêtrière, Paris, France
- INSERM, UMR_S956, ICAN, Hôpital Pitié-Salpêtrière, Paris, France
- * E-mail:
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Gerull B, Kirchner F, Chong JX, Tagoe J, Chandrasekharan K, Strohm O, Waggoner D, Ober C, Duff HJ. Homozygous Founder Mutation in Desmocollin-2 (
DSC2
) Causes Arrhythmogenic Cardiomyopathy in the Hutterite Population. ACTA ACUST UNITED AC 2013; 6:327-36. [DOI: 10.1161/circgenetics.113.000097] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Dominant mutations in cellular junction proteins are the major cause of arrhythmogenic cardiomyopathy, whereas recessive mutations in those proteins cause cardiocutaneous syndromes such as Naxos and Carvajal syndrome. The Hutterites are distinct genetic isolates who settled in North America in 1874. Descended from <100 founders, they trace their origins to 16th-century Europe.
Methods and Results—
We clinically and genetically evaluated 2 large families of the Alberta Hutterite population with a history of sudden death and found several individuals with severe forms of biventricular cardiomyopathy characterized by mainly left-sided localized aneurysms, regions of wall thinning with segmental akinesis, in addition to typical electric and histological features known for arrhythmogenic right ventricular cardiomyopathy. We identified a homozygous truncation mutation, c.1660C>T (p.Q554X) in desmocollin-2 (
DSC2
), in affected individuals and determined a carrier frequency of this mutation of 9.4% (1 in 10.6) among 1535 Schmiedeleut Hutterites, suggesting a common founder in that subgroup. Immunohistochemistry of endomyocardial biopsy samples revealed altered expression of the truncated DSC2 protein at the intercalated discs but only minor changes in immunoreactivity of other desmosomal proteins. Recombinant expressed mutant DSC2 protein in cells confirmed a stable, partially processed truncated protein with cytoplasmic and membrane localization.
Conclusions—
A homozygous truncation mutation in
DSC2
leads to a cardiac-restricted phenotype of an early onset biventricular arrhythmogenic cardiomyopathy. The truncated protein remains partially stable and localized at the intercalated discs. These data suggest that the processed DSC2 protein plays a role in maintaining desmosome integrity and function.
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Affiliation(s)
- Brenda Gerull
- From the Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (B.G., K.C., O.S., H.J.D.), and Department of Medical Genetics (B.G., J.T.), University of Calgary, Calgary, AB, Canada; Max Delbrück Center for Molecular Medicine, Berlin, Germany (F.K.); Department of Human Genetics, The University of Chicago, Chicago, IL (J.X.C., D.W., C.O.); and Centre for Cardiology, Baden-Baden, Germany (O.S.)
| | - Florian Kirchner
- From the Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (B.G., K.C., O.S., H.J.D.), and Department of Medical Genetics (B.G., J.T.), University of Calgary, Calgary, AB, Canada; Max Delbrück Center for Molecular Medicine, Berlin, Germany (F.K.); Department of Human Genetics, The University of Chicago, Chicago, IL (J.X.C., D.W., C.O.); and Centre for Cardiology, Baden-Baden, Germany (O.S.)
| | - Jessica X. Chong
- From the Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (B.G., K.C., O.S., H.J.D.), and Department of Medical Genetics (B.G., J.T.), University of Calgary, Calgary, AB, Canada; Max Delbrück Center for Molecular Medicine, Berlin, Germany (F.K.); Department of Human Genetics, The University of Chicago, Chicago, IL (J.X.C., D.W., C.O.); and Centre for Cardiology, Baden-Baden, Germany (O.S.)
| | - Julia Tagoe
- From the Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (B.G., K.C., O.S., H.J.D.), and Department of Medical Genetics (B.G., J.T.), University of Calgary, Calgary, AB, Canada; Max Delbrück Center for Molecular Medicine, Berlin, Germany (F.K.); Department of Human Genetics, The University of Chicago, Chicago, IL (J.X.C., D.W., C.O.); and Centre for Cardiology, Baden-Baden, Germany (O.S.)
| | - Kumaran Chandrasekharan
- From the Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (B.G., K.C., O.S., H.J.D.), and Department of Medical Genetics (B.G., J.T.), University of Calgary, Calgary, AB, Canada; Max Delbrück Center for Molecular Medicine, Berlin, Germany (F.K.); Department of Human Genetics, The University of Chicago, Chicago, IL (J.X.C., D.W., C.O.); and Centre for Cardiology, Baden-Baden, Germany (O.S.)
| | - Oliver Strohm
- From the Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (B.G., K.C., O.S., H.J.D.), and Department of Medical Genetics (B.G., J.T.), University of Calgary, Calgary, AB, Canada; Max Delbrück Center for Molecular Medicine, Berlin, Germany (F.K.); Department of Human Genetics, The University of Chicago, Chicago, IL (J.X.C., D.W., C.O.); and Centre for Cardiology, Baden-Baden, Germany (O.S.)
| | - Darrel Waggoner
- From the Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (B.G., K.C., O.S., H.J.D.), and Department of Medical Genetics (B.G., J.T.), University of Calgary, Calgary, AB, Canada; Max Delbrück Center for Molecular Medicine, Berlin, Germany (F.K.); Department of Human Genetics, The University of Chicago, Chicago, IL (J.X.C., D.W., C.O.); and Centre for Cardiology, Baden-Baden, Germany (O.S.)
| | - Carole Ober
- From the Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (B.G., K.C., O.S., H.J.D.), and Department of Medical Genetics (B.G., J.T.), University of Calgary, Calgary, AB, Canada; Max Delbrück Center for Molecular Medicine, Berlin, Germany (F.K.); Department of Human Genetics, The University of Chicago, Chicago, IL (J.X.C., D.W., C.O.); and Centre for Cardiology, Baden-Baden, Germany (O.S.)
| | - Henry J. Duff
- From the Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (B.G., K.C., O.S., H.J.D.), and Department of Medical Genetics (B.G., J.T.), University of Calgary, Calgary, AB, Canada; Max Delbrück Center for Molecular Medicine, Berlin, Germany (F.K.); Department of Human Genetics, The University of Chicago, Chicago, IL (J.X.C., D.W., C.O.); and Centre for Cardiology, Baden-Baden, Germany (O.S.)
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Meens MJ, Pfenniger A, Kwak BR, Delmar M. Regulation of cardiovascular connexins by mechanical forces and junctions. Cardiovasc Res 2013; 99:304-14. [PMID: 23612582 DOI: 10.1093/cvr/cvt095] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Connexins form a family of transmembrane proteins that consists of 20 members in humans and 21 members in mice. Six connexins assemble into a connexon that can function as a hemichannel or connexon that can dock to a connexon expressed by a neighbouring cell, thereby forming a gap junction channel. Such intercellular channels synchronize responses in multicellular organisms through direct exchange of ions, small metabolites, and other second messenger molecules between the cytoplasms of adjacent cells. Multiple connexins are expressed in the cardiovascular system. These connexins not only experience the different biomechanical forces within this system, but may also act as effector proteins in co-ordinating responses within groups of cells towards these forces. This review discusses recent insights regarding regulation of cardiovascular connexins by mechanical forces and junctions. It specifically addresses effects of (i) shear stress on endothelial connexins, (ii) hypertension on vascular connexins, and (iii) changes in afterload and the composition of myocardial mechanical junctions on cardiac connexins.
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Affiliation(s)
- Merlijn J Meens
- Department of Pathology and Immunology, Foundation for Medical Research, University of Geneva, 2nd floor, 64 Avenue de Roseraie, 1211 Geneva, Switzerland
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Tavora F, Zhang M, Cresswell N, Li L, Fowler D, Franco M, Burke A. Quantitative Immunohistochemistry of Desmosomal Proteins (Plakoglobin, Desmoplakin and Plakophilin), Connexin-43, and N-cadherin in Arrhythmogenic Cardiomyopathy: An Autopsy Study. Open Cardiovasc Med J 2013; 7:28-35. [PMID: 23802019 PMCID: PMC3680985 DOI: 10.2174/1874192401307010028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 02/23/2013] [Accepted: 02/24/2013] [Indexed: 12/19/2022] Open
Abstract
Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder related to mutations in desmosomal proteins. The current study tests the hypothesis that immunohistochemical staining for desmosomal proteins is of diagnostic utility by studying autopsy-confirmed cases of ARVC. Methods and Results: We studied 23 hearts from patients dying suddenly with ARVC. Control subject tissues were 21 hearts from people dying from non-cardiac causes (n=15), dilated cardiomyopathy (n=3) and coronary artery disease (n=3). Areas free of fibrofatty change or scarring were assessed on 50 sections from ARVC (24 left ventricle, 26 right ventricle) and 28 sections from controls. Immunohistochemical stains against plakoglobin, plakophilin, desmoplakin, connexin-43, and N-cadherin were applied and area expression analyzed by computerized morphometry. Desmin was stained as a control for fixation and similarly analyzed. The mean area of desmin expression was similar in controls and ARVC (86% vs. 85%, p=0.6). Plakoglobin expression was 4.9% ± 0.3% in controls, vs. 4.6% ± 0.3% in ARVC (p=0.3). Plakophilin staining was 4.8% ± 0.3% in controls vs. 4.4% ± 03% in ARVC (p=0.3). Desmoplakin staining was 3.4% in controls vs. 3.2 ± 0.2% in ARVC (p=0.6). There were no significant differences when staining was compared between right and left ventricles (all p > 0.1). For non-desmosomal proteins, the mean area of connexin-43 staining showed no significant difference by presence of disease. Conclusions: The small and insignificant decrease in junction protein expression in ARVC suggests that immunohistochemistry is not a useful tool for the diagnosis.
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Affiliation(s)
- Fabio Tavora
- Escola Paulista de Medicina/UNIFESP, Sao Paulo, Brazil
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Arrhythmogenic right ventricular cardiomyopathy: Reassessing the link with the desmosome. Pathology 2012; 44:596-604. [DOI: 10.1097/pat.0b013e32835a0163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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In vitro functional analyses of arrhythmogenic right ventricular cardiomyopathy-associated desmoglein-2-missense variations. PLoS One 2012; 7:e47097. [PMID: 23071725 PMCID: PMC3468437 DOI: 10.1371/journal.pone.0047097] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 09/10/2012] [Indexed: 01/01/2023] Open
Abstract
Background Although numerous sequence variants in desmoglein-2 (DSG2) have been associated with arrhythmogenic right ventricular cardiomyopathy (ARVC), the functional impact of new sequence variations is difficult to estimate. Methodology/Principal Findings To test the functional consequences of DSG2-variants, we established an expression system for the extracellular domain and the full-length DSG2 using the human cell line HT1080. We established new tools to investigate ARVC-associated DSG2 variations and compared wild-type proteins and proteins with one of the five selected variations (DSG2-p.R46Q, -p.D154E, -p.D187G, -p.K294E, -p.V392I) with respect to prodomain cleavage, adhesion properties and cellular localisation. Conclusions/Significance The ARVC-associated DSG2-p.R46Q variation was predicted to be probably damaging by bioinformatics tools and to concern a conserved proprotein convertase cleavage site. In this study an impaired prodomain cleavage and an influence on the DSG2-properties could be demonstrated for the R46Q-variant leading to the classification of the variant as a potential gain-of-function mutant. In contrast, the variants DSG2-p.K294E and -p.V392I, which have an arguable impact on ARVC pathogenesis and are predicted to be benign, did not show functional differences to the wild-type protein in our study. Notably, the variants DSG2-p.D154E and -p.D187G, which were predicted to be damaging by bioinformatics tools, had no detectable effects on the DSG2 protein properties in our study.
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Kirchner F, Schuetz A, Boldt LH, Martens K, Dittmar G, Haverkamp W, Thierfelder L, Heinemann U, Gerull B. Molecular insights into arrhythmogenic right ventricular cardiomyopathy caused by plakophilin-2 missense mutations. ACTA ACUST UNITED AC 2012; 5:400-11. [PMID: 22781308 DOI: 10.1161/circgenetics.111.961854] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiac disorder mainly caused by dominant mutations in several components of the cardiac desmosome including plakophilin-2 (PKP2), the most prevalent disease gene. Little is known about the underlying genetic and molecular mechanisms of missense mutations located in the armadillo (ARM) domains of PKP2, as well as their consequences on human cardiac pathology. METHODS AND RESULTS We focused on in vivo and in vitro studies of the PKP2 founder mutation c.2386T>C (p.C796R), and demonstrated in cardiac tissue from 2 related mutation carriers a patchy expression pattern ranging from unchanged to totally absent immunoreactive signals of PKP2 and other desmosomal proteins. In vitro expression analysis of mutant PKP2 in cardiac derived HL-1 cells revealed unstable proteins that fail to interact with desmoplakin and are targeted by degradation involving calpain proteases. Bacterial expression, crystallization, and structural modeling of mutated proteins impacting different ARM domains and helices of PKP2 confirmed their instability and degradation, resulting in the same remaining protein fragment that was crystallized and used to model the entire ARM domain of PKP2. CONCLUSIONS The p.C796R and other ARVC-related PKP2 mutations indicate loss of function effects by intrinsic instability and calpain proteases mediated degradation in in vitro model systems, suggesting haploinsufficiency as the most likely cause for the genesis of dominant ARVC due to mutations in PKP2.
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Current World Literature. Curr Opin Cardiol 2012; 27:318-26. [DOI: 10.1097/hco.0b013e328352dfaf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Walsh MA, Grenier MA, Jefferies JL, Towbin JA, Lorts A, Czosek RJ. Conduction abnormalities in pediatric patients with restrictive cardiomyopathy. Circ Heart Fail 2012; 5:267-73. [PMID: 22260945 DOI: 10.1161/circheartfailure.111.964395] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pediatric restrictive cardiomyopathy carries a poor prognosis secondary to a high risk of sudden death previously attributed to ventricular tachyarrhythmias. The extent of conduction abnormalities in this population and their relationship to life-threatening events has not been previously reported. METHODS AND RESULTS A retrospective study of pediatric patients with restrictive cardiomyopathy diagnosed between April 1994 and May 2011 was performed. Demographic, cardiac, and ECG characteristics and the mechanisms of serious arrhythmic events (death or episode of acute hemodynamic compromise thought to be secondary to arrhythmia) were evaluated. Sixteen patients (1-17 years of age) were reviewed, with 5 sudden cardiac events noted, including 4 deaths. Two deaths were caused by development of acute heart block; another patient with syncope had intermittent heart block and survived as the result of pacing features of an implanted defibrillator system. The median PR interval (222 versus 144 ms; P<0.01) and the QRS duration (111 versus 74; P=0.01) were significantly longer in those who had an acute cardiac event. Older age at presentation was associated with sudden cardiac events (P<0.01). No other functional or echocardiographic variables were associated with a sudden cardiac event. CONCLUSIONS Pediatric patients with restrictive cardiomyopathy are at risk for acute high-grade heart block, and, in this cohort, bradycardic events represented a significant portion of all arrhythmic events. Aggressive ECG monitoring strategies looking for conduction system disease should be ongoing in all patients with restrictive cardiomyopathy. Implantation of a defibrillator/pacemaker should be considered as prophylactic management.
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Affiliation(s)
- Mark A Walsh
- Heart Institute, Division of Pediatric Cardiology, Cincinnati Children's Hospital; Medical Center, Cincinnati, OH 45229, USA
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Mezzano V, Sheikh F. Cell-cell junction remodeling in the heart: possible role in cardiac conduction system function and arrhythmias? Life Sci 2011; 90:313-21. [PMID: 22227473 DOI: 10.1016/j.lfs.2011.12.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 12/13/2011] [Accepted: 12/15/2011] [Indexed: 11/28/2022]
Abstract
Anchoring cell-cell junctions (desmosomes, fascia adherens) play crucial roles in maintaining mechanical integrity of cardiac muscle cells and tissue. Genetic mutations and/or loss of critical components in these macromolecular structures are increasingly being associated with arrhythmogenic cardiomyopathies; however, their specific roles have been primarily attributed to effects within the working (ventricular) cardiac muscle. Growing evidence also points to a key role for anchoring cell-cell junction components in cardiac muscle cells of the cardiac conduction system. This is not only evidenced by the molecular and ultra-structural presence of anchoring cell junctions in specific compartments/structures of the cardiac conduction system (sinoatrial node, atrioventricular node, His-Purkinje system), but also because conduction system-related arrhythmias can be found in humans and mouse models of cardiomyopathies harboring defects and/or mutations in key anchoring cell-cell junction proteins. These studies emphasize the clinical need to understand the molecular and cellular role(s) for anchoring cell-cell junctions in cardiac conduction system function and arrhythmias. This review will focus on (i) experimental findings that underline an important role for anchoring cell-cell junctions in the cardiac conduction system, (ii) insights regarding involvement of these structures in age-related cardiac remodeling of the conduction system, (iii) summarizing available genetic mouse models that can target cardiac conduction system structures and (iv) implications of these findings on future therapies for arrhythmogenic heart diseases.
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Affiliation(s)
- Valeria Mezzano
- Department of Medicine (Cardiology Division), University of California-San Diego, La Jolla, CA 92093, USA
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Gehmlich K, Syrris P, Reimann M, Asimaki A, Ehler E, Evans A, Quarta G, Pantazis A, Saffitz JE, McKenna WJ. Molecular changes in the heart of a severe case of arrhythmogenic right ventricular cardiomyopathy caused by a desmoglein-2 null allele. Cardiovasc Pathol 2011; 21:275-82. [PMID: 22036071 DOI: 10.1016/j.carpath.2011.09.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 07/29/2011] [Accepted: 09/16/2011] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder caused by mutations in desmosomal genes. It is often associated with life-threatening arrhythmias. Some affected individuals develop progressive heart failure and may require cardiac transplantation. METHODS The explanted heart of a young adult with end-stage heart failure due to a null allele in desmoglein-2 was studied at macroscopic, microscopic, and molecular level. Myocardial samples were probed for junctional localization of desmosomal components and the gap junction protein connexin43 by immunohistochemical staining. In addition, the protein content of desmosomal and adherens junction markers as well as connexin43 was assessed by Western blotting. RESULTS Histological analysis confirmed ARVC. Despite the loss of specific immunoreactive signal for desmosomal components at the cardiac intercalated disks (shown for plakoglobin, desmoplakin, and plakophilin-2), these proteins could be detected by Western blotting. Only for desmoglein-2, desmocollin-2, and plakoglobin were reduced protein levels observed. Adherens junction proteins were not affected. Lower phosphorylation levels were observed for connexin43; however, localization of the gap junction protein displayed regional differences. At the molecular level, disease progression was more severe in the right ventricle compared to the left ventricle. CONCLUSION Our data suggest that, in the ARVC heart, plakoglobin is mainly redistributed from the junctions to other cellular pools and that protein degradation only plays a secondary role. Homogenous changes in the phosphorylation status of connexin43 were observed in multiple ARVC samples, suggesting that this might be a general feature of the disease.
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Affiliation(s)
- Katja Gehmlich
- Institute of Cardiovascular Science and The Heart Hospital, University College London, United Kingdom.
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Michaelson JE, Huang H. Cell-cell junctional proteins in cardiovascular mechanotransduction. Ann Biomed Eng 2011; 40:568-77. [PMID: 22016325 DOI: 10.1007/s10439-011-0439-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 10/07/2011] [Indexed: 01/14/2023]
Abstract
Cell-cell junctional proteins play important structural and functional roles in several physiological systems. Recent studies have illuminated key aspects in the relationship of junctional proteins with normal cell and tissue function as well as various pathologies. In this review article, the roles of cell-cell junctional proteins will be presented in four classes: adherens junctions, desmosomes, gap junctions, and tight junctions, and discussed primarily in the context of cardiovascular cell and tissue physiology and pathophysiology. The functions of the proteins are described from the perspective of mechanotransductive regulation of physiological and disease processes, with focus being laid on more biomechanical aspects, such as cell adhesion, migration, and mechanosignaling.
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Affiliation(s)
- Jarett E Michaelson
- Biomedical Engineering Departmental Office, Columbia University, New York, NY 10027, USA.
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